J Protein Chem, 1991 Feb, 10(1), 25 - 9 Eukaryotic glucose-6-phosphate dehydrogenases: structural screening of related proteins; Bergman T et al.; Rapid assessment of structural relationships between yeast glucose-6-phosphate dehydrogenases and other eukaryotic types of this enzyme is described . Separation and size estimation of large fragments by sodium dodecylsulfate/polyacrylamide gel electrophoresis, electroblotting onto disks, and sequencer analysis provide data that permit alignment of the segments thus characterized with the related proteins, and utilize existing structural knowledge to assess new enzyme structures . Affinity labeling allows further correlations . The results establish the overall structural arrangements of the new proteins, including the location of the active-site lysine residue, even though the yeast enzyme structures are found to differ markedly from the few previously characterized glucose-6-phosphate dehydrogenases. Bone Marrow Transplant, 1991 Feb, 7(2), 127 - 31 Does ketoconazole prevent fungal infection in children treated with high dose chemotherapy and bone marrow transplantation? Results of a randomized placebo-controlled trial; Benhamou E et al.; Between August 1985 and October 1988 125 children who were candidates for a bone marrow transplantation entered a randomized double-blind placebo-controlled trial (63 children in ketoconazole (K) group and 62 children in placebo (P) group) to evaluate the efficacy of ketoconazole in decreasing the incidence of digestive yeast colonization . Among the 38 children who were initially colonized, the proportion of children who became decolonized was higher (p less than 0.05) in group K (47%) than in group P (16%) . Among the 87 children without initial colonization, the proportion of children in whom digestive colonization occurred was lower (p less than 0.01) in group K (20%) than in group P (49%) . Three children in group K (5%) and six children in group P (9%) developed a documented fungal infection (NS) . Thirty-nine children in each group developed a fever of unknown origin which did not respond to a 7-day course of antibiotherapy . One hundred and three children received amphotericin B (Ampho B) (83% in group K and 82% in group P) . The mean duration (+/- SD) of Ampho B was similar in group K (28 +/- 26 days) and in group P (28 +/- 25 days) . The mean total dose of Ampho B was similar in group K (475.5 +/- 1060 mg) and in group P (540.4 +/- 979 mg) . The actuarial survival from the day of randomization until bone marrow recovery was not different in the two groups . We conclude that ketoconazole is efficient in preventing gut yeast colonization but does not reduce the incidence of fungal documented infections and fevers of unknown origin unresponsive to antibiotherapy which necessitate empirical coverage and treatment with Ampho B. Anal Biochem, 1991 Feb 1, 192(2), 358 - 61 The use of pH indicators to identify suitable environments for freezing samples in aqueous and mixed aqueous/nonaqueous solutions; Hill JP et al.; The colours of frozen solutions containing pH indicators are shown to provide a test for changes in pH in the solvent environment which occur on freezing . Yeast alcohol dehydrogenase loses activity on freezing in phosphate buffer (a buffer in which pH indicator colour changes shows a marked decrease in pH on freezing) but when frozen in bis-tris, Hepes, or N-glycylglycine buffers (all of which show little change in the colour of universal pH indicator and hence of pH on freezing) is stable on freezing . The effects of freezing in different buffer systems on the rate of decomposition of NADPH, and on the rate hydrolysis of 4-nitrophenyl acetate, are rationalised in terms of the pH shifts in these buffers which were determined using universal pH indicator . It is proposed that a major reason for the instability of samples on freezing is the pH changes which occur when some systems are frozen . From the results a general scheme for selecting the best environment for safely freezing samples is proposed which is based on the use of pH indicators. Mycopathologia, 1991 Feb, 113(2), 109 - 15 Macrocyclic trichothecenes produced by Stachybotrys isolated from Egypt and eastern Europe; el-Maghraby OM et al.; Twenty seven isolates of Stachybotrys chartarum, S . albipes, S . kampalensis and S . microspora from Egypt and Eastern Europe were tested for production of macrocyclic trichothecenes . Twenty of the 27 isolates, grown on rice seeds, were toxic to brine shrimp larvae . Based on TLC and HPLC analyses, 5 macrocyclic trichothecenes (verrucarin J, roridin E, satratoxins F, G & H) as well as trichoverrols were identified . When grown in liquid culture on rice extract medium, only 3 isolates were toxic and produced verrucarin J, roridin E and satratoxins G & H . Extracts from mycelial mats were more toxic than culture filterates of two isolates grown on rice extract and both contained the same macrocyclic trichothecenes (285.5 mg/4 L), in addition to trichoverrols A & B (31 mg/4 L) found in mycelial mats only . When grown on 3% sucrose Czapek's medium supplemented with peptone and yeast extract (still cultures), all isolates were non-toxic to brine shrimp and no trichothecenes could be detected in the extracts. Biochem Cell Biol, 1991 Feb-Mar, 69(2-3), 211 - 5 Sequence of an acidic ribosomal protein from the jellyfish Polyorchis penicillatus; Gallin W; We have isolated a cDNA clone from the jellyfish Polyorchis penicillatus that encodes the homologue of the A1 acidic ribosomal protein previously characterized in human, brine shrimp, fruit fly, and yeast . The sequence of this protein is strongly conserved among the five eukaryotic species for which it has been determined . Conservation is greatest in the amino-terminal 51 amino acids and the carboxyl-terminal 25 amino acids . This suggests that these regions are necessary for interactions with other components of the protein synthetic machinery, while the central part of the protein has a less specific role to play . Comparison of the sequences obtained from the different species indicate that the metazoan lineages all appear to have arisen at approximately the same time and significantly later than the time of divergence of yeast from the common ancestor of the Metazoa. J Cutan Pathol, 1991 Feb, 18(1), 28 - 35 Majocchi's granuloma; Smith KJ et al.; Majocchi's granuloma (nodular granulomatous perifolliculitis) is a well recognized but uncommon infection of dermal and subcutaneous tissue by fungal organisms (dermatophytes) usually limited to the superficial epidermis . The organism usually associated with Majocchi's granuloma is Trichophyton rubrum; however, other dermatophytes including T . mentagrophytes (variety granulosum), T . epilans, T . violaceum, M . audouinii, M . gypseum, M . ferrugineum, and M . canis may be the causative agent . A review of 17 cases revealed not only the variety of possible organisms but also a marked variation from the usual hyphal forms . The morphologic variations including yeast forms, bizarre hyphae, mucinous coatings, and the Splendore-Hoeppeli phenomenon may be factors which allow the dermatophytes to persist and grow in an abnormal location . Also, there is evidence that Majocchi's granuloma may occur in two distinct groups of patients. J Mol Endocrinol, 1991 Feb, 6(1), 63 - 70 Cloning and characterization of a gene encoding pig epidermal growth factor; Pascall JC et al.; A portion of the pig epidermal growth factor (EGF) gene has been isolated and characterized . The nucleotide sequencies of exons 20 and 21, which encode the EGF region of the precursor protein, show 85% similarity with the human EGF gene sequence . In addition, conservation of the intron-exon boundaries between the two species was generally observed . Although the pig exon 21 appeared to lack a single nucleotide at its 5' end relative to the human gene, sequences obtained by direct amplification of the genomic DNA around the 5' end of this exon using the polymerase chain reaction, and from a pig EGF cDNA recombinant isolated from a kidney library, indicated that the deletion was probably a cloning artifact . Comparison of the predicted amino acid sequence of pig EGF with that of EGF from other species, as well as with several other polypeptides which bind to the EGF receptor, indicated conservation of Gly18, Tyr37, Gly39 and Arg41 in addition to all six cysteine residues and Leu47, which are known to be critical for biological activity . A synthetic gene encoding the predicted amino acid sequence of pig EGF was expressed in yeast . The recombinant polypeptide was shown to compete with 125I-labelled mouse EGF for binding to cells and to stimulate DNA synthesis in quiescent monolayers of Swiss 3T3 cells. Mutat Res, 1991 Feb, 262(2), 93 - 9 Effects of selenium deficiency on sperm morphology and spermatocyte chromosomes in mice; Watanabe T et al.; Sperm morphology and spermatocyte chromosomes were examined in mice maintained on a Torula yeast diet for 5 weeks . In the selenium-deficient group, the proportion of abnormal sperm was high, ranging from 6.8% to 49.6%, while in the control group it ranged from only 4.0% to 15.0% . The most frequently occurring abnormalities in sperm shape were in the sperm head . There was also a tendency for abnormalities in other regions (neck, midpiece and tail) to be increased . However, in metaphase-I spermatocytes, the frequencies of various types of abnormal chromosomes (univalent chromosomes, translocations and structural anomalies) did not differ between the selenium-deficient and control groups . These findings indicate that selenium day be an essential constituent for spermatogenesis in mice. Hum Genet, 1991 Feb, 86(4), 350 - 4 Chromosome assignment of four RAS-related RAB genes; Rousseau-Merck MF et al.; The human RAB genes share structural and biochemical properties with the RAS gene superfamily . The encoded RAB proteins show 38 to 75% amino acid identity with the yeast YPT1 and SEC4 gene products . We used four human RAB-cDNAs, RAB3B, RAB4, RAB5 and RAB6, to map the corresponding genes on human chromosomes . These genes were assigned to 1p32-p31, 1q42-q43, 3p24-p22 and 2q14-q21, respectively, by in situ hybridization. Genes Dev, 1991 Feb, 5(2), 298 - 309 Identification of functional domains in the maize transcriptional activator C1: comparison of wild-type and dominant inhibitor proteins; Goff SA et al.; Genes encoding fusions between the maize regulatory protein C1 and the yeast transcriptional activator GAL4 and mutant C1 proteins were assayed for their ability to trans-activate anthocyanin biosynthetic genes in intact maize tissues . The putative DNA-binding region of C1 fused to the transcriptional activation domain of GAL4 activated transcription of anthocyanin structural gene promoters in c1 aleurones, c1 Rscm2 embryos, and c1 r embryogenic callus . Cells receiving these constructs accumulated purple anthocyanin pigments . The C1 acidic region fused to the GAL4 DNA-binding domain activated transcription of a GAL4-regulated promoter . An internal deletion of C1 also induced pigmentation; however, frameshifts in either the amino-terminal basic or carboxy-terminal acidic region blocked trans-activation, and the latter generated a dominant inhibitory protein . Fusion constructs between the wild-type C1 cDNA and the dominant inhibitor allele C1-I cDNA were used to identify the amino acid changes in C1 responsible for the C1-I inhibitory phenotype . Results from these studies establish that amino acids within the myb-homologous domain are critical for transcriptional activation. J Infect Dis, 1991 Feb, 163(2), 219 - 25 Safety and immunogenicity of a genetically engineered human immunodeficiency virus vaccine; Wintsch J et al.; A phase 1 trial of a candidate human immunodeficiency virus type 1 (HIV-1) vaccine was done in 25 healthy seronegative subjects . The antigen, env2-3 (SF2), was a nonglycosylated polypeptide representing the gp120 region of the env gene of the HIV-1(SF2) isolate . It was produced in genetically engineered yeast as a denatured molecule incapable of binding CD4 . A synthetic lipophilic muramyl tripeptide (MTP-PE) was used as an adjuvant . Ten subjects received adjuvant alone and 15 received 50- or 250-micrograms doses of env2-3 (SF2) administered intramuscularly in two immunization regimens . In general, adjuvant and vaccine were well tolerated . Antibody responses to both the homologous antigen, env2-3 (SF2), and antigens from other highly divergent HIV isolates were elicited in the majority of vaccine recipients . However, antibody titers were low, without neutralizing activity . In 9 of 11 subjects who received the complete vaccine immunization series, a significant specific T lymphocyte response was observed. Mol Biol Med, 1991 Feb, 8(1), 95 - 100 Additional mutations in argininosuccinate synthetase causing citrullinemia; Kobayashi K et al.; Deficiency of argininosuccinate synthetase causes arginine auxotrophy in lower organisms and causes citrullinemia in humans and cattle . Previously, seven missense mutations, four mutations associated with an absence of an exon in mRNA, and one splicing mutation have been identified in human neonatal citrullinemia . Reverse transcription of mRNA, amplification of cDNA and sequencing of cDNA clones were used to identify two additional missense mutations causing citrullinemia . One mutation involves substitution of leucine for serine at position 18 (S18L) and the other a substitution of cysteine for arginine at position 86 (R86C) . Both of these mutations represent C----T transitions in CpG dinucleotides, and eight of nine missense mutations causing human citrullinemia involve similar transitions in CpG dinucleotides . The nucleotide coding sequence and deduced amino acid analysis are available for four mammalian species, yeast and three bacterial species . Six of nine missense mutations in humans occur in amino acid positions that are completely conserved in these organisms . Mutations causing human citrullinemia are extremely heterogeneous, and all non-consanguineous individuals studied to date are compound heterozygotes. Mycopathologia, 1991 Feb, 113(2), 121 - 5 Different media and methodologies for the detection of aflatoxin production by Aspergillus flavus strains isolated from trout feed; Cutuli MT et al.; We have studied the aflatoxin producing capacity of 41 Aspergillus flavus strains isolated from the mycoflora present of natural media (wheat, rice and mixed feed) synthetic medium (Aflatoxin Producing Ability Medium) and semisynthetic media (Coconut Agar Medium and Glucose Yeast Extract Agar) were compared . Aflatoxins were analysed on days 4 and 8 post-inoculation under an incubation temperature of 28 degrees C . A total of 30 strains (75.7%) were producers on natural media as detected by Thin Layer Chromatography: 23 strains on wheat, 27 on rice and 12 on mixed feed . The results by qualitative fluorescence tests on synthetic and semisynthetic media were: 3 strains positive on Coconut Agar Medium (CAM) 1 on Glucose Yeast Extract Agar (GY + Agar) and none on Aflatoxin Producing Ability Medium (APA). Mutat Res, 1991 Feb, 259(2), 165 - 76 Aneuploidy in Drosophila, IV . Inhalation studies on the induction of aneuploidy by nitriles; Osgood C et al.; The Drosophila ZESTE system was used to monitor the induction of sex chromosome aneuploidy following inhalation exposure of adult females to four nitriles: acetonitrile, propionitrile, acrylonitrile and fumaronitrile . Acetonitrile and propionitrile were highly effective aneuploidogens, inducing both chromosome loss and chromosome gain following brief exposures to low concentrations of these chemicals, and these nitriles also induced rapid paralysis . Acrylonitrile-induced chromosome loss only but did not induce paralysis . Fumaronitrile, in contrast with the results reported in yeast, was ineffective in inducing chromosome loss or gain . Virtually all exceptional offspring induced by acetonitrile and propionitrile were recovered in the first sampled eggs, corresponding to treated mature oocytes . Additionally, the time interval between treatment and sampling was shown to be important, suggesting rapid loss or detoxification of the nitriles . Genetic analysis demonstrated that most aneuploids resulted from induced segregation errors during the first division of meiosis . Cold treatments were found to be ineffective in enhancing the effects of acetonitrile, suggesting important differences between the Drosophila and yeast aneuploidy detection systems . Possible mechanisms by which nitriles may disrupt chromosome segregation in Drosophila oocytes are considered. Antonie Van Leeuwenhoek, 1991 Feb, 59(2), 81 - 93 Bulleromyces genus novum (Tremellales), a teleomorph for Bullera alba, and the occurrence of mating in Bullera variabilis; Boekhout T et al.; Mating is observed in Bullera alba and B . variabilis, resulting in the formation of dikaryotic mycelium with clamps, haustorial branches, and lateral and terminal dikaryotic, clavate, lageniform or subglobose cells . These cells develop in B . alba into tremellaceous phragmobasidia . Karyogamy has been observed in young non-divided basidia . Germination of the phragmobasidia occurred by acropetal chains of yeast cells, ballistospores or hyphae . Septal pores are dolipores with parenthesomes made up of U-shaped vesicles (Tremellales type) . For the teleomorph of B . alba a new genus, Bulleromyces, is proposed, with only one species, viz . Bulleromyces albus. Plant Cell, 1991 Feb, 3(2), 105 - 13 Monocot regulatory protein Opaque-2 is localized in the nucleus of maize endosperm and transformed tobacco plants; Varagona MJ et al.; Protein targeting to the nucleus has been studied extensively in animal and yeast systems; however, nothing is known about nuclear targeting in plants . The Opaque-2 (O2) gene produces a regulatory protein that is responsible for inducing transcription of the alpha-zein class of storage proteins in maize kernels . The cloned O2 gene encodes a protein that contains a leucine zipper DNA binding domain that can interact with zein gene promoters . We have used immunolocalization to show that the O2 protein is present in nuclei in the maize endosperm tissues known to produce alpha-zeins . In addition, neither embryo tissue from wild-type kernels nor endosperm from kernels harboring a null o2 allele contain the O2 protein . Analysis of a transposable, element-induced o2 allele, o2-m20, revealed that sectors of endosperm cells contained the nuclear-localized O2 protein, indicating excision of the transposable element . To study further the nuclear transport of the O2 protein, we have transformed this gene, under the control of a constitutive promoter, into tobacco . Plants were shown to have detectable levels of steady-state O2 mRNA and O2 protein . Immunolocalization of O2 protein in transformed tobacco plants indicated that the O2 protein was transported into tobacco nuclei . Therefore, we have developed a system to study nuclear targeting in plants and have established that the nuclear transport machinery is similar in monocots and dicots. Chromosoma, 1991 Feb, 100(2), 118 - 24 He-T family DNA sequences in the Y chromosome of Drosophila melanogaster share homology with the X-linked stellate genes; Danilevskaya ON et al.; The genome of Drosophila melanogaster contains a class of repetitive DNA sequences called the He-T family, which is unusual in being confined to telomeric and heterochromatic regions . The specific He-T fragment designated Dm665 was cloned in yeast by selection for an autonomously replicating sequence (ARS) . Dm665 contains a restriction fragment length polymorphism (RFLP) that is specific to males and thus derives from the Y chromosome . Deletion mapping using X-Y translocations indicates that sequences homologous to Dm665 occur in at least one major cluster in each arm of the Y chromosome . Among 20 yeast artificial chromosome (YAC) clones containing Drosophila sequences homologous with Dm665, four clones derive from defined regions of the long arm of the Y and two from the short arm . The sequence of Dm665 is 2443 bp long, consists of 59% A + T, and contains no significant open reading frames or direct or inverted repeats . However, Dm665 contains a region of 650 bp that shares homology with portions of the X-linked locus Stellate. Int J Hematol, 1991 Feb, 54(1), 49 - 55 Aclacinomycin, an anti-leukemic anthracycline, impairs human neutrophil functions; Katoh M et al.; The effects of aclacinomycin, an anti-leukemic anthracycline, on human neutrophil functions were investigated . The release of superoxide (O2-) in neutrophils stimulated by opsonized zymosan, myristate, or phorbol myristate acetate was inhibited by aclacinomycin in a dose- and time-dependent manner . The phagocytosis of yeast particles and oil droplets, and membrane potential changes stimulated by phorbol myristate acetate were also inhibited by aclacinomycin . On the other hand, the O2(-)-producing enzyme (NADPH oxidase) in the particulate fraction prepared from myristate-stimulated neutrophils was not affected by aclacinomycin . When high concentrations of aclacinomycin (10-100 micrograms/ml) were employed, significant inhibition of O2- release, phagocytosis, and membrane potential changes was observed within 5 min . Phagocytic activity was also inhibited when neutrophils were preincubated for 13 h at 37 degrees C with a low concentration (40 ng/ml) of aclacinomycin, which could be obtained by intravenous administration of 20 mg aclacinomycin . Myristate-induced O2- release was not impaired by cytosine arabinoside (2-800 micrograms/ml), vincristine (0.1-100 micrograms/ml), adriamycin (25-100 micrograms/ml), or daunomycin (5-75 micrograms/ml) when the cells were preincubated with these drugs for 5 min at 37 degrees C . These findings suggest that aclacinomycin inhibits the respiratory burst by impairing the activating system of NADPH oxidase and phagocytic activity. Plant Mol Biol, 1991 Feb, 16(2), 283 - 92 Specificity of leaf mitochondrial and chloroplast processing systems for nuclear-encoded precursor proteins; Whelan J et al.; The specificity of the mitochondrial and chloroplast processing enzymes for the nuclear-encoded precursor proteins was investigated . Mitochondrial precursor proteins of the Nicotiana plumbaginifolia and the Neurospora crassa beta subunits of F1-ATPase and the Neurospora Rieske FeS precursor protein were processed to the correct mature size by matrix extracts isolated from spinach leaves, yeast, rat liver and beef heart . The mitochondrial extracts failed to process chloroplast precursor proteins of the stromal small subunit of ribulose 1,5-bisphosphate carboxylase and the thylakoid 33 kDa protein of the oxygen-evolving complex . Both mitochondrial F1 beta precursors were specifically processed by a soluble stromal extract from chloroplasts . However, no processing of the Rieske FeS precursor protein was observed under the same conditions with the chloroplast extract . The cleavage of the mitochondrial F1 beta precursors by the chloroplast extract was shown to be sensitive to the metal chelators EDTA and ortho-phenanthroline . The cleavage site of the mitochondrial F1 beta precursor by the chloroplast soluble extract appears to be located at the N-terminus. Trends Biochem Sci, 1991 Feb, 16(2), 63 - 7 Mitochondrial import receptors for precursor proteins; Pfanner N et al.; The specific targeting of precursor proteins synthesized in the cytosol to various cell organelles is a central aspect of intracellular protein traffic . Several hundred different proteins are imported from the cytosol into the mitochondria . Recent studies have identified the mitochondrial outer membrane proteins MOM19, MOM72, MOM38 (approximately ISP42) and p32 which have a role in initial steps of protein import . The first three components are present in a multi-subunit complex that catalyses recognition and membrane insertion of precursor proteins. Biochemistry, 1991 Jan 29, 30(4), 1010 - 6 Rat liver polysome N alpha-acetyltransferase: isolation and characterization; Yamada R et al.; Rat liver polysome N alpha-acetyltransferase has been purified to homogeneity by a four-step procedure that utilizes ammonium sulfate precipitation, gel filtration, hydroxylapatite chromatography, and Mono Q ion exchange chromatography . The enzyme is greatly stabilized by the inclusion of EDTA and 0.01% deoxycholate in the isolation buffers . The purified enzyme has a native molecular weight of 190,000 and a subunit molecular weight of 95,000, suggesting that it is a homodimer . The enzyme shows a pH optimum of 8.0 and is strongly inhibited by Cl-, I-, SCN-, and ClO4- and to a lesser degree by sulfate and acetate . It is unaffected by phosphate, citrate, and F- and by Na+ and K+; NH4+ is partially inhibitory . The enzyme is also sensitive to iodoacetic acid . It is generally more similar to yeast N alpha-acetyltransferase {Lee, F.-J . S., Lin, L.-W., & Smith, J . A . (1988) J . Biol . Chem . 263, 14948-14955} than to the hen oviduct enzyme, which contains a 7S RNA subunit {Kamitani, K., & Sakiyama, F . (1989) J . Biol . Chem . 264, 13194-13198}, although the amino acid compositions are quite different. Biochemistry, 1991 Jan 29, 30(4), 997 - 1004 Secondary structure of a complement control protein module by two-dimensional 1H NMR; Barlow PN et al.; The complement control protein (CCP) module (also known as the short consensus repeat) is a consensus sequence of about 60 amino acid residues which is thought to fold independently . It occurs over 140 times in more than 20 extracellular mosaic proteins including 12 proteins of the complement cascade . An isolated CCP module, the 16th repeat from human complement factor H, has been expressed in a yeast vector and shown to fold with the same pattern of disulfide bond formation as is seen in the native protein . Two-dimensional 600-MHz 1H NMR spectra of this module have been recorded at pH 3.3 and 6.0 and analyzed to permit determination of secondary structure in solution . The CCP module comprises two predominantly extended segments (Glu1-His13 and Ala17-Glu27), two segments of double-stranded antiparallel beta-sheet (Gly14-Val16 paired with Tyr31-Cys33 and Gly38-Asp40 paired with Ser57-Ile59), and a short piece of triple-stranded beta-sheet (Glu27-Thr30, Ile44-Leu48, and Lys51-Ser53) . Turns occur at Asp22, Gly36, and Glu50, while Gly41-Ala43 appear to form a looped-out segment or bulge . This structure is compared with a secondary structure prediction made on the basis of an alignment scheme of 101 sequences for CCP modules {Perkins, S . J., Haris, P . I., Sim, R . B., & Chapman, D . (1988) Biochemistry 27, 4004-4012}--the experimentally determined secondary structure bears an overall resemblance to the predicted one but differs in the number and position of turns . Some of those amino acid residues which are highly conserved throughout the range of CCP modules appear to play a role in stabilizing the global fold. J Biol Chem, 1991 Jan 25, 266(3), 1448 - 55 The primary structure of human glutaminyl-tRNA synthetase . A highly conserved core, amino acid repeat regions, and homologies with translation elongation factors; Fett R et al.; We describe the nucleotide sequences of several overlapping cDNA clones specific for human glutaminyl-tRNA synthetase . The identified open reading frame indicates that the enzyme is composed of 1440 amino acids . A stretch of about 360 amino acids of the human enzyme is highly conserved in bacterial and yeast glutaminyl-tRNA synthetases . However, the human enzyme is three times larger than the bacterial and twice as large as the yeast enzyme suggesting that a considerable part of human glutaminyl-tRNA synthetase has evolved to perform functions other than the charging of tRNA . The sequence outside of the conserved core region includes three 57-amino acid repeats followed by a consecutive stretch of 11 charged amino acids . A computer assisted search of two protein data banks reveals that the human glutaminyl-tRNA synthetase shares small blocks of amino acid similarities with several other synthetases of different amino acid specificities . Interestingly, the enzyme also possesses some regions of similarities with eukaryotic translation elongation factor EF-1 but not with any other sequence stored in the protein data banks . The coding regions of human and mouse glutaminyl-tRNA synthetase cDNAs are identical at 94% of the codons . However, the 3'-noncoding regions of mouse and human mRNAs are more divergent (approximately 68%) but both possess the potential to form stable secondary structures of similar general architecture. Nucleic Acids Res, 1991 Jan 25, 19(2), 287 - 96 A novel 40S multi-snRNP complex isolated from rat liver nuclei; Guialis A et al.; Two structurally distinct RNP complexes (MI and MII), each with a sedimentation value of approx . 40S, were isolated from rat liver nuclear extracts by sucrose gradient centrifugation and subsequent native gel electrophoresis of the 40S hnRNP-containing fractions . MII RNP contained the bulk of hnRNA and hnRNP proteins (i.e . the 32-45KD core proteins and polypeptides of 60-80 and 110-130KD) . MI RNP was characterized by the exclusive presence of U-snRNAs (U1, U2, U4, U5 and U6), their well known snRNP polypeptides and a number of Sm-associated proteins in the range of 50-210KD . Immunoselection experiments employing a monoclonal antibody with an established specificity for the U2-snRNP-specific B" polypeptide proved that the RNA and protein components characteristic of MI were part of a single multi-snRNP unit . The prominent 200/210KD protein doublet of MI was identified immunochemically as the rat homologue of the yeast PRP8 protein, a known U5-associated splicing component . Based on the major biochemical and immunochemical features of MI and MII RNP complexes, we conclude that MII represents the monomeric 40S hnRNP structure, whereas MI defines a novel multi-snRNP entity. Science, 1991 Jan 25, 251(4992), 426 - 30 A genetic model for interaction of the homeodomain recognition helix with DNA; Hanes SD et al.; The Bicoid homeodomain protein controls anterior development in the Drosophila embryo by binding to DNA and regulating gene expression . With the use of genetic assays in yeast, the interaction between the Bicoid homeodomain and a series of mutated DNA sites was studied . These experiments defined important features of homeodomain binding sites, identified specific amino acid-base pair contacts, and suggested a model for interaction of the recognition alpha-helices of Bicoid and Antennapedia-class homeodomain proteins with DNA . The model is in general agreement with results of crystallographic and magnetic resonance studies, but differs in important details . It is likely that genetic studies of protein-DNA interaction will continue to complement conventional structural approaches. Int J Cancer, 1991 Jan 21, 47(2), 281 - 4 Treatment of leukemia L1210 and P388 by arabinosylcytosine-polysaccharide conjugates; Novotny L et al.; Conjugates of 1-beta-D-arabinofuranosylcytosine (araC) with two polysaccharides such as polygalacturonic acid (PGA) and carboxymethylated yeast beta-D-glucan (CMG) were tested for their antileukemic activity in vitro on a L1210 cell line in suspension culture, in soft agar assay and in vivo on L1210, L1210/araC- and P388-leukemia-bearing mice . Both conjugates showed high activity in vitro in soft agar assay, compared with araC . Single administration of PGA-araC or CMG-araC increased the survival time 1.5 x or 1.7 x, respectively, compared with araC in vivo in L1210-leukemia-bearing mice . The conjugates were not active against araC-resistant leukemia line L1210/araC . The marked effect of both PGA-araC and CMG-araC against leukemia L1210 and P388 is probably due to the prolonged release of free araC from conjugates caused by hydrolysis. Gene, 1991 Jan 15, 97(2), 191 - 8 Cloning of several lignin peroxidase (LIP)-encoding genes: sequence analysis of the LIP6 gene from the white-rot basidiomycete, Phanerochaete chrysosporium; Zhang YZ et al.; A Phanerochaete chrysosporium BKMF1767 genomic library, constructed in the BamHI site of vector YRp12, was screened with the lignin peroxidase(LIP)-encoding cDNAs, CLG4 and CLG5, that have been shown to encode LIP2 (previously H2) and LIP6 (previously H10), respectively . Six distinct LIP genomic clones, designated pGLG1, pGLG2, pGLG3, pGLG4, pGLG5, and pGLG6, were isolated in this study . Probe CLG4 hybridized only to pGLG1 . Probe CLG5 gave intense hybridization to pGLG2 and weaker hybridization to clones pGLG3 through pGLG6, but showed little or no hybridization to pGLG1 . These results, in agreement with previous biochemical results, indicate the existence of LIP gene subfamilies . The limits and transcriptional orientation of the LIP gene in each clone were determined . The sequence data showed that pGLG2 contains the LIP6 gene, which encodes a protein identical in amino acid (aa) composition to that encoded by CLG5 . It contains a leader sequence of 27 aa and a mature protein of 344 aa (Mr 36,607) . Archetypal TATA-box-like and CAAT-box-like sequences in the 5'-noncoding region are located 51 and 97 nt upstream from the cDNA start point, respectively . S1 nuclease analysis of the 5' region of LIP6 revealed two transcription start points 8 nt apart downstream from the TATA box . Comparison of the sequence of LIP6 with its corresponding cDNA CLG5 showed that the gene contains nine small introns which range in size from 50 to 62 bp . These introns contained consensus splice junction sequences similar to those reported in other fungal and yeast introns. Proc Natl Acad Sci U S A, 1991 Jan 15, 88(2), 561 - 4 X-ray scattering indicates that the leucine zipper is a coiled coil; Rasmussen R et al.; Dimerization of the bZIP class of eukaryotic transcriptional control proteins requires a sequence motif called the leucine zipper . We have grown two distinct crystal forms of a 33-amino acid peptide corresponding to the leucine zipper of the yeast transcriptional activator GCN4 . This peptide is known to form a dimer of parallel helices in solution . X-ray scattering from both crystal forms shows reflections that are diagnostic of coiled coils . The most notable reflections occur at approximately 5.2 A resolution and correspond to the pitch of helices in coiled coils . There is no diffraction maximum near 5.4 A, the characteristic pitch of straight helices . Our results provide direct evidence that the leucine zipper of GCN4 is a coiled coil. Ned Tijdschr Geneeskd, 1991 Jan 12, 135(2), 68 - 73 {Utilization of food supplements in The Netherlands}; Dorant E et al.; In 1987 and 1988 a dietary survey was carried out in a representative sample of the Dutch population, under the authority of the Ministries of Welfare, Health and Cultural Affairs, and Agriculture and Fisheries . By means of a two day dietary record data were collected on food consumption and the use of dietary supplements . More than seventeen percent of the Dutch population has been using at least one dietary supplement on at least one day of the survey . Age, sex, season, social class, alternative food habits, smoking and diet are related to the use of supplements . In young persons mainly fluoride and vitamin AD preparations are used, while as age progresses a shift towards other supplements, like garlic and brewer's yeast preparations, is observed . The use of single vitamin C supplements is not related to the level of mean daily vitamin C intake from foods. Nucleic Acids Res, 1991 Jan 11, 19(1), 149 - 54 Structural and transcriptional analysis of a human subtelomeric repeat; Cheng JF et al.; A human subtelomeric repeat (designated as the HST repeat) has been isolated and characterized from a yeast artificial chromosome containing one human telomere . This repeat is located immediately adjacent to the telomeric T2AG3 repeats at the extreme termini of the human chromosomes . The DNA sequence of 3.6 kb of the HST repeat has been determined . The HST repeat spans over 3.6 kb in length, and contains one evolutionarily conserved CpG-rich region . The copy number of the HST repeat varies among telomeres . Genomic hybridization experiments suggest that the HST repeat consists of two distinct segments, and the distal portions of the HST repeat are also distributed elsewhere in the genome . In HeLa cells, the HST repeat sequence appears to be transcribed into a 6 kb polyadenylated RNA and a variety of non-polyadenylated RNA species. Cell, 1991 Jan 11, 64(1), 149 - 57 S . pombe gene sds22+ essential for a midmitotic transition encodes a leucine-rich repeat protein that positively modulates protein phosphatase-1; Ohkura H et al.; The fission yeast dis2+ gene encodes one of the two type 1 protein phosphatases (PP1) in this organism . Its semidominant mutant dis2-11 is defective in mitosis . Here we report the characterization of a high dosage suppressor, sds22+, that complements dis2-11 . Sequencing of the cloned sds22+ gene predicts a novel 30 kd protein, which consists almost entirely of leucine-rich 22 amino acid repeats and is enriched in the insoluble nuclear fraction . sds22+ is an essential gene required for the mitotic metaphase/anaphase transition; gene disruption causes cell cycle arrest at midmitosis . Unexpectedly, the sds22+ gene becomes dispensable upon high dosage of the PP1 genes . The sds22+ product appears to facilitate PP1-dependent dephosphorylation, but does not substitute PP1 . We propose that the sds22+ protein forms a repeating helical rod that is capable of enhancing a PP1-dependent dephosphorylation activity that is essential in midmitosis. Nature, 1991 Jan 3, 349(6304), 79 - 81 A small GTP-binding protein dissociates from synaptic vesicles during exocytosis; Fischer von Mollard G et al.; Low-molecular-weight GTP-binding proteins are strong candidates for regulators of membrane traffic . In yeast, mutations in the sec4 or ypt1 genes encoding small GTP-binding proteins inhibit constitutive membrane flow at the plasma membrane or Golgi complex, respectively . It has been suggested that membrane fusion-fission events are regulated by cycling of small GTP-binding proteins between a membrane-bound and free state, but although most of these small proteins are found in both soluble and tightly membrane-bound forms, there is no direct evidence to support such cycling . In rat brain a small GTP-binding protein, rab3A, is exclusively associated with synaptic vesicles, the secretory organelles of nerve terminals . Here we use isolated nerve terminals to study the fate of rab3A during synaptic vesicle exocytosis . We find that rab3A dissociates quantitatively from the vesicle membrane after Ca2(+)-dependent exocytosis and that this dissociation is partially reversible during recovery after stimulation . These results are direct evidence for an association-dissociation cycle of a small GTP-binding protein during traffic of its host membrane. J Chromatogr, 1991 Jan 2, 562(1-2), 421 - 34 Liquid secondary ion mass spectrometry applied to structural confirmation of enzymically prepared C-terminal-truncated derivatives of recombinant hirudin; Maftouh M et al.; The thrombin-specific inhibitor, hirudin variant rHV2-Lys 47 (rHirudin), is a 65-amino acid polypeptide produced by recombinant DNA technology in yeast . Previous studies have shown that the acidic C-terminal segment of hirudin is susceptible to enzymic degradation . To address the question of C-terminal-truncated forms of the protein in terms of by-products or metabolites, well-defined reference compounds are needed . We prepared nine derivatives by carboxypeptidase Y digestion of rHirudin followed by a two-step chromatographic purification . Liquid secondary ion mass spectrometric measurements performed on peptides collected after reversed-phase high-performance liquid chromatography showed three pure forms (1-64, 1-63 and 1-56) and three mixtures of two forms each (1-62 + 1-61, 1-58 + 1-57 and 1-55 + 1-54), which were readily distinguished from one another by their mass spectra . Further purification of these co-eluted samples was achieved by ion-exchange chromatography and their structures were confirmed by liquid secondary ion mass spectrometry . Preliminary studies conducted on intact rHirudin indicated that this is an excellent analytical tool for mass measurements of hirudin-related proteins . Indeed, it allowed rapid (within 10-15 min), precise (0.50 a.m.u . relative to expected value), reproducible (mean MH+ = 6907.64 +/- 0.42 a.m.u.), sensitive (up to 500 ng, i.e . 72 pmol) and specific measurement of the quasi-molecular ion (MH+) of the protein, and was thus readily applicable to the analysis of several derivatives. Antibiot Khimioter, 1991 Jan, 36(1), 35 - 7 {Effect of proper-myl on humoral interactions between activated lymphocytes and neutrophils in patients with myeloproliferative diseases}; Guseva SA; The lymphokine synthesizing function of peripheral blood lymphocytes (PBL) was studied in 22 patients with chronic myeloid leukemia (CML), 28 patients with subleukemic myelosis (SLM) and 15 healthy persons . The index of the neutrophil stimulation (INS) in CML (1.73 +/- 0.068) and SLM (1.458 +/- 0.004) was statistically significantly lower than that in the healthy persons (2.6 +/- 0.07) . The use of proper-myl in the complex therapy markedly increased the ability of PBL to produce the factor stimulating phagocytic activity of neutrophils (INS 1.94 +/- 0.04 and 1.832 +/- 0.092) . On the basis of the findings it was recommended to use proper-myl for prevention and treatment of infectious complications. Am J Clin Oncol, 1991, 14 Suppl 1, S51 - 63 Clinical effects of recombinant human interleukin-3; Ganser A et al.; Interleukin-3 (IL-3) is a glycoprotein belonging to the hematopoietic growth factor family that in preclinical in vitro and in vivo studies has exhibited a multilineage activity . Phase I/II trials with recombinant human IL-3 (rhIL-3) expressed in yeast are being done in patients with advanced malignancies as well as in patients with bone marrow failure states . Subcutaneous administration of rhIL-3 at dosages between 30 and 500 micrograms/m2 for 15 consecutive days has resulted in a dose-dependent increase in platelet counts as well as in a substantial increase in the number of circulating neutrophils, eosinophils, monocytes, and lymphocytes in patients with advanced malignancies but normal hematopoiesis . Erythropoiesis is less stimulated with an increase in hemoglobin concentration only in a minority of patients . In patients with secondary hematopoietic failure due to prolonged chemo-/radiotherapy or bone marrow infiltration by tumor cells, treatment with rhIL-3 leads to a clinically significant restoration of hematopoiesis, especially of thrombopoiesis and granulopoiesis . rhIL-3 has also been shown to improve neutrophil and platelet counts in patients with myelodysplastic syndromes, while improvement of hematopoiesis is rarely observed in patients with severe aplastic anemia with the presently used treatment schedules . Adverse effects of rhIL-3 are minor at the clinically used dosages and include fever, bone pain, headache, and stiffness of the neck . Transient thrombocytopenia has been observed in a few patients with myelodysplastic syndrome or aplastic anemia treated at dosages of 250-500 micrograms/m2 . rhIL-3 is a multilineage hematopoietic cytokine with promising effects on platelet and neutrophil counts and special usefulness in patients with secondary hematopoietic failure. Intervirology, 1991, 32(3), 160 - 72 Antibody reactivity to deletion mutants of the HIV-1 SF2 envelope; Back NK et al.; In human immunodeficiency virus type 1 (HIV-1) infected individuals, the antibody response to the external envelope (gp120) is associated with in vitro neutralization . To further characterize the anti-gp120 response, we examined the IgG reactivity of 75 HIV-1-seroconverted and 200 HIV-1-seropositive individuals to deletion mutants of gp120 in an enzyme immunoassay . We used yeast-derived, non-glycosylated recombinant HIV-1 SF2 gp120 equivalent and-variants deleted in variable regions . We observed two distinctive response patterns: IgG non-responders (SF2-V3-restricted responders) and IgG responders to conserved regions of gp120 . This divergence in response pattern occurred soon after gag/env HIV-1 antibody seroconversion and persisted in time within an individual . In addition, the SF2-V3-restricted responders had a higher frequency of HIV-1 core antigen positivity and HIV-1 core antibody negativity than the non-restricted responders . These results suggest that specific and persistent host antibody response patterns to gp120 develop early in HIV-1 infection and that these patterns are associated with differences in HIV-1 expression. J Clin Lab Anal, 1991, 5(2), 121 - 6 Correlation of Histoplasma capsulatum polysaccharide antigen with the severity of infection in murine histoplasmosis; Williams BJ et al.; We sought to determine if Histoplasma capsulatum polysaccharide antigen (HPA) levels correlate with the extent of infection in murine of histoplasmosis . Separate groups of mice were inoculated intratracheally with varying numbers of H . capsulatum yeast cells . After 1 week, HPA levels and fungal burden (quantitative culture of lung and spleen and histopathologic stain of lung) were determined in lung and spleen, and HPA levels in serum . HPA levels, cultures and histopathological stain results of lung and spleen tissue showed a direct correlation with increasing inoculum size . HPA levels in serum also correlated with the size of inoculum . H . capsulatum antigen in lung correlated with silver stain scores of lung tissue, (R = 0.948, P less than 0.001) and with quantitative culture scores of lung, (R = 0.929, P less than 0.001) . HPA levels in spleen tissue also correlated with spleen culture scores, (R = 0.724, P less than 0.001) . These results indicate that determination of HPA level in serum and tissue may be a useful test in evaluating the severity of diseases as well as efficacy of antifungal therapy in histoplasmosis. Can J Microbiol, 1991 Jan, 37(1), 86 - 95 Isolation and sequencing of a genomic DNA clone containing the 3' terminus of the 6-methylsalicylic acid polyketide synthetase gene of Penicillium urticae; Wang IK et al.; A 7.7-kilobase (kb) Penicillium urticae genomic DNA fragment containing the 3' terminus of the 6-methylsalicylic acid polyketide synthetase gene was cloned using a 41-mer mixed oligodeoxynucleotide probe which was based on a cyanogen bromide cleavage peptide of 35 amino acids obtained from pure synthetase . Nucleotide sequence analysis of a 2.2-kb region of the cloned fragment revealed a large open reading frame of 1866 bases which was devoid of introns and which corresponded to amino acids of the carboxyl terminus of the enzyme . This was followed by a putative transcription termination--polyadenylation signal . A putative acyl carrier protein domain at the 3' terminus was preceded by a beta-ketoreductase domain . These functionalities were identified by amino acid sequences known to be characteristic of the active sites of fatty acid synthetase functional domains . Their relative positions contrast with those in yeast and P . urticae fatty acid synthetase genes where the two functional domains are located at the 5' terminus and in reverse order . Furthermore, amino acid sequence identities indicated a striking homology with vertebrate rather than either yeast or P . urticae fatty acid synthetases. Bull Cancer, 1991 Jan, 78(1), 1 - 21 {Different regulation systems of cell cycle events (dysregulation of these events in the tumoral cell)}; Colomb E et al.; Preservation of the shape and the integrity of multicellular eukaryotes needs rigorous cell proliferation monitoring . During the prereplicative G1 phase, a finely adjusted and specific control supervises the proliferant/non proliferant states of the cells . Some molecular mechanisms of growth regulation have been identified in recent years . Changes in normal cell attachment on extracellular matrix and intercellular chemical signalling (secretion of informative molecules) activate intracellular signals for division . The transduction mechanisms of the extracellular signalling to the nucleus have been partially elucidated for steroid hormones and growth factors . Molecular biology research and proto-oncogene discoveries have led to considerable progress in understanding the role of these normal genes in the control of cellular proliferation . The initiation of the response to extracellular factors requires: i), direct transducers (specific binding of the steroid hormone on its cytoplasmic or nuclear receptor and high affinity binding of this activated complex to specific DNA sequences); and ii) indirect transducers (binding of growth factors on extracellular domains of specific receptor proteins which convert this extracellular event into several intracellular signals, secondary messengers, protein kinases and specific nuclear regulatory factors) . Whatever the transduction system, nuclear events control transcription of growth regulatory genes . The series of enzymatic reactions set in motion by indirect transduction systems require strict regulation systems, the diversity and the complexity of which has been perceived in studies on jun and fos gene families . Each proliferation step is governed by growth stimulators and growth inhibitors, the transformation of normal cells to cancer cells resulting from alterations of these regulatory process . Independent of extracellular stimuli and of their transfer to the nucleus, intracellular controls coordinate cell cycle phases (G1, S, G2 and M) to produce daughter cells identical to the original cell . Two control points are particularly critical: one in G1 (the "start" point) and the other in G2 just before mitosis . Although intermediate steps between extracellular and intracellular controls are still unknown, yeast gene analyses have allowed determination of molecular regulatory mechanisms implicated in the passage of these critical points . A considerable advance was made by the discovery that some of the involved components presented strong sequence and function homologies in organisms from yeast to man, suggesting a phyllogenetically conserved mechanism . It seems likely that the phosphorylation state of protein p34, its association with a G1-phase specific cyclin or a M-phase specific cyclin, and its protein kinase activity regulate the proliferation state of higher eukaryotic cells . In spite of significant advances, much research is still necessary to elucidate all the mechanisms involved in cell cycle control. Pharmacol Biochem Behav, 1991 Jan, 38(1), 21 - 7 Analgesic and acute central nervous system side effects of the intravenously administered enkephalinase inhibitor SCH 32615; Chipkin RE et al.; The analgesic and acute central nervous system (CNS) side effect potential of the enkephalinase inhibitor SCH 32615 (N-{L-(1-carboxy-2-phenyl)ethyl}-L-phenyl-alanine-beta-alanine) were evaluated after IV administration to mice, rats and squirrel monkeys . In mice, SCH 32615 caused dose-related suppression of acetic acid-induced writhing (minimal effective dose, MED = 3 mg/kg IV) . In rats, SCH 32615 produced dose-related increases in the response latencies in the yeast inflamed-paw test (MED = 10 mg/kg IV) . In squirrel monkeys, using a new hot-water bath tail-flick test, SCH 32615 significantly prolonged the escape latencies (MED = 100 mg/kg IV) . These results in primates are the first data showing an analgesic action of an enkephalinase inhibitor in a reflex model of pain . When measured for its CNS side effect potential, SCH 32615 had no significant effects in rats (up to 100 times its analgesically active doses) or in monkeys (up to three times) . In the mouse, at doses 100 times its minimal effective dose, SCH 32615 produced brief convulsions; these lasted only a minute, resolved quickly, and did not cause lethality . In contrast, in rats and squirrel monkeys, the standard opioid analgesic morphine produced profound CNS side effects; this was particularly notable in monkeys, in which morphine's maximal analgesic effects were associated with near lethal respiratory depression . These data demonstrate that SCH 32615 produces selective analgesic actions and that its acute side effect liability is less than that seen with a clinically used standard. Am J Trop Med Hyg, 1991 Jan, 44(1), 28 - 33 Plasmodium vivax sporozoite antibodies in individuals exposed during a single malaria outbreak in a non-endemic area; Fontes CJ et al.; We studied seroreactivity against Plasmodium vivax antigens in 62 individuals living in a small community near Mantena, Minas Gerais, Brazil, an area outside the endemic malaria zone Brazil . Eight months earlier, there had been transmission of P . vivax for a period of 50 days, which was then totally controlled by chemotherapy and insecticides . An anti-sporozoite response, measured by ELISA using a recombinant protein expressed in yeast, was detected in 45% (14 of 31) of individuals eight months after infection and persisted for 20 months in 12% . Eighteen individuals were treated prophylactically for malaria because they lived in houses in which an overt infection had occurred . Seven of these individuals were ELISA positive; of these, 5 had antibodies against the blood stage parasites . Among 13 other individuals in the endemic area who did not have positive smears, had not been ill, and had not received prophylaxis, five were anti-circumsporozoite positive up to a 40-fold serum dilution . They did not develop asexual blood stage antibodies and remained parasite-free for the following 20 months. J Nutr, 1991 Jan, 121(1), 50 - 6 Comparative antioxidant effectiveness of dietary beta-carotene, vitamin E, selenium and coenzyme Q10 in rat erythrocytes and plasma; Zamora R et al.; Five groups of five weanling rats were each fed a Torula yeast-based diet either unsupplemented or supplemented with 30 mg beta-carotene/kg, 30 IU vitamin E/kg, 1 mg selenium/kg or 30 mg coenzyme Q10/kg . Elevated levels of plasma aspartate aminotransferase and alanine aminotransferase are sensitive indicators of liver damage . The former enzyme was lower (P less than 0.01) in the vitamin E-, selenium- and beta-carotene-supplemented groups than in the unsupplemented control group, and the latter enzyme was lower in the vitamin E- and selenium-supplemented groups, suggesting a relatively equal effectiveness of these three antioxidants against liver damage . Erythrocytes were tested for protection against uninduced oxidative damage or that induced by 1 mmol/L bromotrichloromethane (BrCl3C) by measuring thiobarbituric acid-reactive substances (TBARS), hemoglobin, hemolysis, protein precipitation, alanine release and several enzyme activities . In untreated erythrocytes, selenium, beta-carotene and coenzyme Q10 exhibited protection by lowering (P less than 0.05) TBARS and alanine release, but only vitamin E protected against hemolysis . In BrCl3C-treated erythrocytes, vitamin E, selenium and beta-carotene protected by decreasing (P less than 0.05) protein precipitation, whereas selenium and beta-carotene decreased alanine release . The results of this study suggested that, in a manner analogous to vitamin E and selenium, beta-carotene and coenzyme Q10 function as antioxygenic nutrients. J Allergy Clin Immunol, 1991 Jan, 87(1 Pt 1), 107 - 10 Caffeine, a naturally occurring acaricide; Russell DW et al.; Since caffeine is a plant alkaloid that has been described as a naturally occurring insecticide, its acaricidal effect on Dermatophagoides pteronyssinus (Dp) was investigated . Twelve cultures were established by adding 30 Dp to 200 mg of Tetramin fish food and brewer's yeast (8:2 ratio); six cultures were treated with 20 mg of finely ground caffeine . All 12 cultures were incubated at 75% relative humidity, 25 degrees C, and observed during 8 weeks . Live mites were then counted under a stereoscope, cultures were extracted, and supernatants were analyzed for Der p I and Der f I allergen content with a two-site monoclonal RIA . Live mite counts in untreated cultures varied from 146 to 274 (215 +/- 47.1), and in caffeine-treated cultures from 0 to 3 (1 +/- 1.2; p less than or equal to 0.0001) . Der p I concentrations in untreated cultures varied from 588 to 9000 ng/gm (3138.3 +/- 2990.8 ng/gm), and in caffeine-treated cultures from 52 to 117 ng/gm (78 +/- 23.8 ng/gm; p less than or equal to 0.01) . Der p I was not detected in the food media or caffeine; Der f I was not detected in any of the cultures . Results demonstrate that caffeine inhibits mite growth and allergen production. Cancer Res, 1991 Jan 1, 51(1), 105 - 9 Variant human breast tumor estrogen receptor with constitutive transcriptional activity; Fuqua SA et al.; Since progesterone receptor (PgR) is normally induced by estrogen, breast cancer lacking estrogen receptor (ER) would also be expected to lack PgR . However, a small percentage of breast cancers are ER- yet PgR+ . These tumors might possess an ER which is defective in estrogen binding but is still functional in stimulating estrogen-responsive genes such as PgR . We have now detected such a variant, lacking exon 5 of the hormone-binding domain, using complementary DNA amplified by the polymerase chain reaction . This variant was the predominate ER RNA expressed in three ER-/PgR+ tumors . Furthermore, the variant ER constitutively activates transcription of a normally estrogen-dependent gene construct in yeast cells . The variant ER could explain the expression of PgR in certain tumors and have therapeutic implications. Infect Immun, 1991 Jan, 59(1), 428 - 32 Genetic control of natural resistance in mouse macrophages regulating intracellular Legionella pneumophila multiplication in vitro; Yoshida S et al.; It is known that Legionella pneumophila proliferates in peritoneal macrophage cultures derived from A/J mice but not in macrophage cultures derived from many other strains, including C57BL/6 mice . To analyze the genetic control of this trait and the location of the Legionella resistance-susceptibility gene, we prepared segregating progeny of A/J and C57BL/6 mice and determined the levels of susceptibility of individual mice . Peritoneal macrophages were collected by injecting thioglycolate medium, and macrophage monolayers were infected in vitro with L . pneumophila Philadelphia-1 . Counting of colonies on buffered charcoal yeast extract agar plates and Gimenez staining of macrophage monolayers were carried out daily . There was a 10-fold increase in bacterial burden 1 day after infection and a 100-fold increase after 2 days in A/J (susceptible) macrophages . The increase in bacterial burden was always less than 10-fold in macrophages from C57BL/6 (resistant) progenitors, A/J x C57BL/6 F1 hybrids, and C57BL/6 x F1 backcross progeny . The ratios of resistant individuals to susceptible individuals were 22:6 for F2 progeny and 20:22 for A/J x F1 backcross progeny . The fact that the organism did not proliferate in macrophages from B10.A mice demonstrated that major histocompatibility antigens did not regulate the macrophage resistance of C57BL/6-derived mice . The sex and coat color genes of mice were not linked to the resistance-susceptibility gene . We suggest that resistance and susceptibility are controlled by a single gene or closely linked genes which are autosomal and that the resistance allele is dominant . The results of a comparison of the strain distribution pattern of this trait with the distribution pattern of 185 allelic markers in A/J x C57BL/6 and C57BL/6 x A/J recombinant inbred strains suggest that this susceptibility-resistance gene is located in the proximal part of chromosome 15. Proc Natl Acad Sci U S A, 1991 Jan 1, 88(1), 144 - 8 Molecular cloning and characterization of interferon alpha/beta response element binding factors of the murine (2'-5')oligoadenylate synthetase ME-12 gene; Yan C et al.; Seven clones encoding interferon response element binding factors have been isolated from a mouse fibroblast lambda gt11 cDNA library by using a 32P end-labeled tandem trimer of the mouse (2'-5')oligoadenylate synthetase gene interferon response element as a probe . Clone 16 shares strong similarity (95%) at both DNA and amino acid level with YB-1, a human major histocompatibility complex class II Y-box DNA-binding protein, and with dbpB, a human epidermal growth factor receptor gene enhancer region binding protein . The product of the gene represented by clone 16 may represent a factor that regulates multiple genes by binding to a variety of 5' regulatory elements . Clone 25 is a 2407-base-pair-long cDNA and contains a putative 311-amino acid open reading frame corresponding to an estimated mass of 35.5 kDa . This putative protein, designated as interferon response element binding factor 1 (IREBF-1), contains an acidic domain, three heptad repeat leucine arrays, and a region that shares similarity with the yeast transcriptional factor GAL4 DNA-binding domain . Furthermore, the C terminus of IREBF-1 shows an unusual amphipathic property: within a 79-amino acid range, one side of the alpha-helical region contains a preponderance of hydrophobic amino acids and the other side contains hydrophilic amino acids . This type of structure provides a strong hydrophobic force for protein-protein interaction. Mol Cell Biol, 1991 Jan, 11(1), 240 - 9 Structure and regulation of histone H2B mRNAs from Leishmania enriettii; Genske JE et al.; We have studied the structure and expression of histone H2B mRNA and genes in the parasitic protozoan Leishmania enrietti . A genomic clone containing three tandemly repeated genes has been sequenced and shown to encode three identical histone proteins and two types of closely related mRNA sequence . We have also sequenced three independent cDNA clones and demonstrated that the Leishmania H2B mRNAs are polyadenylated, similar to the basal histone mRNAs of higher eucaryotes and the histone mRNAs of yeast . In addition, the Leishmania mRNAs contain inverted repeats near the poly(A) tail which could form stem-loops similar in secondary structure, but not in sequence, to the 3' stem-loops of nonpolyadenylated replication-dependent histones of higher eucaryotes . Unlike the replication-dependent histones, the Leishmania histone H2B mRNAs do not decrease in abundance following treatment with inhibitors of DNA synthesis . The histone mRNAs are differentially expressed during the parasite life cycle and accumulate to a higher level in the extracellular promastigotes (the form which in nature lives within the gut of the insect vector) than in the intracellular amastigotes (the form that lives within the mammalian host macrophages). J Immunol, 1991 Jan 1, 146(1), 244 - 9 Moderate zinc deficiency in rhesus monkeys . An intrinsic defect of neutrophil chemotaxis corrected by zinc repletion; Vruwink KG et al.; Experimental animals fed zinc-deficient diets are well known for susceptibility to infections and impaired mitogen response and Ig production . However, the levels of zinc deficiency used have generally been severe, not comparable to human populations, and have not addressed neutrophil function . To address this issue we have studied the effect in rhesus monkeys of a well defined moderately zinc-deficient (MZ) diet on polymorphonuclear leukocyte (PMN) function . Female adult rhesus monkeys were fed either a control (100 micrograms Zn/g) or MZ (2 micrograms Zn/g) diet for 9 mo with quantitation of PMN chemotaxis, and phagocytosis of opsonized yeast . In addition, membrane potential and secretion responses (changes in 90 degrees light scatter) and changes in PMN shape (forward light scatter shifts) were also measured . When compared to the PMN of animals fed control diets, there was a significant reduction in chemotaxis to FMLP of MZ-fed monkey PMN . Although shape change, cell membrane depolarization, as well as phagocytosis were not significantly different among the two groups, the PMN of MZ animals had significantly lower relative loss of orthogonal light scatter (degranulation) due primarily to a lower resting orthogonal light scatter and also a smaller loss when stimulated with FMLP . In vitro addition of zinc to the cells (25 microM) did not improve chemotaxis, and in fact, was inhibitory for most control and zinc-deficient cells . However, after 2 wk of dietary zinc repletion (100 micrograms Zn/g), chemotaxis in the low zinc group was higher and comparable to the control response . These data indicate that zinc deficiency is associated with an intrinsic PMN defect that specifically affects chemotaxis and is corrected with dietary zinc repletion. Ciba Found Symp, 1991, 159, 174 - 83; discussion 183-7 Antibody catalysis of carbon-carbon bond formation; Hilvert D; We have used rationally designed transition state analogues to generate antibodies that catalyse two important carbon-carbon bond forming reactions: a bimolecular Diels-Alder cycloaddition and a unimolecular Claisen rearrangement . Our tailored immunoglobulin catalysts (abzymes) exhibit all the properties of naturally occurring enzymes, including substantial rate accelerations, substrate specificity, and high regio- and stereoselectivity . As first generation abzymes are generally inferior to naturally occurring enzymes, we are also employing classical genetic selection strategies to augment their chemical efficiency . We have expressed the antibody that catalyses the Claisen rearrangement of chorismate in yeast cells that lack natural chorismate mutase activity . Improved versions of the abzyme will be identified, following random mutagenesis, by their ability to repair this metabolic defect . The development and study of highly efficient catalytic antibodies promises to advance our understanding of how enzymes work and evolve, how protein function correlates with structure, and how entirely new enzymic activities can be created for use in research, industry and medicine. J Med Vet Mycol, 1991, 29(5), 335 - 8 Candida haemulonii from clinical specimens in the USA; Gargeya IB et al.; Classical yeast identification procedures and DNA relatedness studies confirmed the occurrence of Candida haemulonii among clinical specimens in the USA, particularly isolations from the foot . None of the six clinical isolates studied produced identical API 20C profile codes. Mycoses, 1991 Jan-Feb, 34(1-2), 47 - 52 Pathogenesis of postoperative candidosis: no detectable fungemia during reoperations after abdominal surgery; Rantala A et al.; Pathogenesis of systemic candidosis in surgical patients is unsettled . Results from animal models suggest that invasion from colonized intestine is the major portal of entry into circulation . To study the mechanisms of systemic candidosis in surgical patients after intestinal surgery, multiple blood cultures were taken during reoperations with manipulation of the intestinum to detect possible perioperative fungemia . The lysis centrifugation method (Isolator) was used for blood cultures . Of the 30 subjects in the material, 12 were demonstrated to be colonized with yeast before the reoperation . Three patients had positive blood cultures during reoperation, but no yeasts were found in the 146 perioperative blood cultures . Three patients had severe nonsuperficial yeast infection after reoperation, but none had disseminated candidosis . This finding in high risk patients supports the view that immediate perioperative fungemia and persorption from colonized intestinum is rare . However, persorption may occur later via healing wounds of the colonized intestinum . Both persorption and the exogenous route (e.g . vascular catheters) are possible in the pathogenesis of postoperative candidosis. Mycoses, 1991 Jan-Feb, 34(1-2), 1 - 18 The medically important dematiaceous fungi and their identification; Dixon DM et al.; Dematiaceous fungi include a large group of organisms that are darkly pigmented (dark brown, olivaceous, or black) . In most cases the pigment is melanin, and specifically, dihydroxynaphthalene melanin . The diseases produced include chromoblastomycosis, eumycotic mycetoma, and phaeohyphomycosis . Phaeohyphomycosis is a new classification for a diverse group of previously known entities grouped together on the basis of finding dematiaceous hyphal and/or yeast-like forms in tissue; tissue involvement may be superficial, cutaneous and corneal, subcutaneous, or systemic . Identification of these fungi is based mostly upon morphology . Important structures include annellides (Phaeoannellomyces, Exophiala), phialides (Phialophora, Wangiella), adelophialides (Phialemonium without collarettes, Lecythophora with collarettes), differentiation of conidiophores (Xylohypha versus Cladosporium) and conidial hilum, septation and germination (Bipolaris, Drechslera, Exserohilum) . Useful laboratory tests include the 12% gelatin test (controversial), nitrate assimilation (W . dermatitidis is negative, most other species are positive), and determination of temperature maxima (especially 37 degrees C for E . jeanselmei, 40 degrees C for W . dermatitidis and B . spicifera, 42 degrees C for X . bantiana, and 45 degrees C for Dactylaria constricta var . gallopava and Scedosporium inflatum). Int J Vitam Nutr Res, 1991, 61(2), 130 - 4 Bioavailability of folate following ingestion of cholestyramine in the rat; Hoppner K et al.; The effect of cholestyramine ingestion on the intestinal deconjugation and absorption of folic acid (PGA) and brewers yeast folate was investigated using a rat bioassay and liver folate uptake as the response parameter . Male weanling Sprague Dawley rats were depleted on a low AIN-76A formulated basal diet for 21 days . During a 14 day repletion period folic acid (PGA) and brewers yeast were added to provide 0.25, 0.5 and 1.0 mg of folate per kg of diet . Cholestyramine was administered directly as part of the diet at 1.1% . All diets were made isonitrogenous and isocaloric . Based on a parallel line assay, the relative biological value of folate for PGA + cholestyramine (79) was significantly different from the standard diet (PGA = 100), while those for brewers yeast (88) and for brewers yeast + cholestyramine (88) did not differ from the standard diet . Ingestion of cholestyramine significantly reduced the bioavailability of PGA versus brewers yeast folate in rats. Biochem Int, 1991 Jan, 23(1), 151 - 6 Diadenosine polyphosphates inhibit the action of ribonucleotide reductase on ADP; Wasternack C et al.; Using permeabilized cells prepared according to Lammers, M . and Follmann, H . (Arch . Biochem . Biophys . 244, 430-438, 1986), the ribonucleotide reductase (EC 1.17.4.1) of yeast was assayed in situ . In our experimental conditions, 40-200 pmoles of ADP were reduced in 10 min per 5 x 10(7) cells . Concentrations of 0.01 mM of diadenosine tri, tetra, penta and hexaphosphates elicited inhibitions of 37, 40, 63 and 58%, respectively . The enzyme was almost completely inhibited in the presence of 0.05 mM diadenosine pentaphosphate . As some of these dinucleotides are present in yeast cells at these concentrations, the reported inhibition may have physiological meaning. Int J Vitam Nutr Res, 1991, 61(1), 72 - 6 Chromatography of selenoproteins in human serum using matrix-bound heparin; Akesson B et al.; Since previous experiments indicated that a major selenoprotein in human serum interacts with heparin, chromatography of serum on matrix-bound heparin was studied . When human serum was applied to heparin-agarose columns, approximately half of the applied selenium was not retained on the columns . Approx . 40% of the selenium could then be eluted either with increasing concentrations of heparin or ammonium acetate . Using a scaled-down version of this procedure, selenoproteins from 0.5 ml serum were separated into the heparin-binding and non-heparin-binding fractions . In an experiment where healthy subjects were given supplements of yeast selenium (200 micrograms/d) for eight weeks, the concentration of selenium in serum was almost doubled and then approached the original concentration 16 weeks after the end of the supplementation . During supplementation, no change in the concentration of heparin-binding selenoproteins was observed, and instead the increase in serum selenium occurred in non-heparin-binding proteins . This suggests that the need for selenium by the heparin-binding proteins was saturated already at the starting serum selenium level (1.0 mumol/l) . Since interaction with heparin has been observed also for selenoprotein P isolated from rat plasma, the protein in the heparin-binding fraction, demonstrated in this paper, may be a human analogue to selenoprotein P. J Rheumatol, 1991 Jan, 18(1), 66 - 71 Effects of pyrophosphatase on dissolution of calcium pyrophosphate dihydrate crystals; Xu Y et al.; Understanding the dissolution mechanisms involved in calcium pyrophosphate dihydrate (CPPD) crystals may prove important for the development of therapy for CPPD arthropathy . We demonstrate that yeast pyrophosphatase effectively dissolved CPPD crystals in solutions . Maximum enzymatic dissolution of CPPD crystals was achieved at neutral pH and when the enzyme had access to the crystal surface . The enzymatic dissolution of CPPD crystals was highly dependent on ambient {Mg++} and {Ca++} . The stimulating effects of Mg++ on crystal dissolution in the presence of the enzyme is due to stimulation of pyrophosphatase activity and to enhanced direct release of pyrophosphate ions from the crystal surface . The inhibiting effect of Ca++ on crystal dissolution by the enzyme is mainly due to the suppression of pyrophosphatase activity. Int J Syst Bacteriol, 1991 Jan, 41(1), 6 - 14 Characterization of mitochondrial DNA in various Candida species: isolation, restriction endonuclease analysis, size, and base composition; Su CS et al.; A practical and effective method for the extraction of mitochondrial DNA from Candida species was developed . Zymolyase was used to induce yeast protoplasts, and mitochondrial DNA was extracted from DNase I-treated mitochondrial preparations . Restriction endonuclease analyses of mitochondrial DNAs from 19 isolates representing seven species of Candida (C . albicans, C . kefyr, C . lusitaniae, C . maltosa, C . parapsilosis, C . shehatae, and C . tropicalis) and Lodderomyces elongisporus revealed different cleavage patterns that appeared to be specific for the species . Few common restriction fragments were evident . The genome sizes of the mitochondrial DNAs ranged from 26.4 to 51.4 kilobase pairs, and the guanine-plus-cytosine contents ranged from 20.7 to 36.8 mol% . There was no correlation between the base compositions of nuclear and mitochondrial DNAs . Eight isolates of C . parapsilosis, including the type culture, and an ascosporogenous strain of L . elongisporus, which was once proposed as the teleomorph of C . parapsilosis, had similar mitochondrial DNA molecular sizes (30.2 and 28.8 kilobase pairs); however, restriction endonuclease patterns of these organisms were distinct . These data provide additional support for discrimination of these two species . The results of our experiments demonstrate that mitochondrial DNA analyses may provide useful criteria for the differentiation of yeast species. Am J Respir Cell Mol Biol, 1991 Jan, 4(1), 72 - 81 Exposure of humans to ambient levels of ozone for 6.6 hours causes cellular and biochemical changes in the lung; Devlin RB et al.; An acute (2 h) exposure of humans to 0.4 ppm ozone initiates biochemical changes in the lung that result in the production of components mediating inflammation and acute lung damage as well as components having the potential to lead to long-term effects such as fibrosis . However, many people are exposed to lower levels of ozone than this, but for periods of several hours . Therefore, it is important to determine if a prolonged exposure to low levels of ozone is also capable of causing cellular and biochemical changes in the lung . Nonsmoking males were randomly exposed to filtered air and either 0.10 ppm ozone or 0.08 ppm ozone for 6.6 h with moderate exercise (40 liters/min) . Bronchoalveolar lavage (BAL) was performed 18 h after each exposure, and cells and fluid were analyzed . The BAL fluid of volunteers exposed to 0.10 ppm ozone had significant increases in neutrophils (PMNs), protein, prostaglandin E2 (PGE2), fibronectin, interleukin-6 (IL-6), and lactate dehydrogenase (LDH) compared with BAL fluid from the same volunteers exposed to filtered air . In addition, there was a decrease in the ability of alveolar macrophages to phagocytize yeast via the complement receptor . Exposure to 0.08 ppm ozone resulted in significant increases in PMNs, PGE2, LDH, IL-6, alpha 1-antitrypsin, and decreased phagocytosis via the complement receptor . However, BAL fluid protein and fibronectin were no longer significantly elevated . We conclude that exposure of humans to as low a level as 0.08 ppm for 6.6 h is sufficient to initiate an inflammatory reaction in the lung. Princess Takamatsu Symp, 1991, 22, 3 - 19 Molecular basis of multistage carcinogenesis; Harris CC; Revealing the molecular basis of human disease including cancer will be viewed as one of the triumphs of biomedical research in the 20th Century . One successful strategy has been to analyze abnormalities in cancer-related genes occurring in preneoplastic and neoplastic lesions in humans and animal models . These gene abnormalities, e.g., mutations, can be specifically linked in some cases to environmental carcinogens in molecular epidemiological studies of human populations and in more controlled experimental conditions using animal or in vitro models of carcinogenesis . A second successful strategy has been to capitalize on advances from basic research such as defining signal transduction pathways in mammalian cells and the genetic control of the cell cycle in yeast . Mutations in yeast cell division control genes can lead to genomic instability and aneuploidy which are hallmarks of cancer . Therefore, the role of these genes in human carcinogenesis is being intensely investigated . The involvement of the p53 gene in the majority of human cancers has focused attention on the molecular and biochemical mechanisms of this tumor suppressor gene . The analysis of the p53 mutational spectrum in human cancers has provided evidence that both exogenous and endogenous causes of mutation contribute to human carcinogenesis . The increased understanding of the molecular basis of carcinogenesis has important implications in the prevention, diagnosis and treatment of human cancer. Princess Takamatsu Symp, 1991, 22, 145 - 52 Spi1 GTPase interacts with RCC1 to maintain interdependency of cell cycle events; Matsumoto T et al.; A mutant which can enter mitosis at any cell cycle stage has been isolated and characterized in fission yeast . The pim1 (premature initiation of mitosis) mutant prearrested at G1/S can develop a mitotic spindle and has tightly condensed chromosomes upon shift to the restrictive temperature . pim1-induced mitosis requires maturation promoting factor (MPF) activity, but not the essential mitotic inducer, cdc25 . The pim1+ gene encodes a homolog of regulator of chromosome condensation 1 (RCC1), a regulator of onset of mitosis in mammalian cells . A multicopy suppressor of pim1, spi1, was isolated, and found to encode a 25 kDa GTPase . The primary sequence of the spi1 GTPase shows extensive identity (80%) to human TC4, whose function is unknown . The spi1/TC4 GTPase defines a novel class in the "ras-like" GTPase family, which is distinct from ras, rho, or ypt . Disruption of the spi1+ gene causes genomic instability in a heterozygous diploid . These genetic data suggest that pim1+ and spi1+ interact to coordinate correct entry into mitosis . Immunological experiments demonstrate that the pim1+ and spi1+ products are physically associated . Mutation in the pim1 gene results in lowered affinity of the protein for the spi1 protein in vitro, which may explain why high dosages of the spi1 protein can rescue the pim1 mutant in vivo . The pim1/spi1 complex dissociates in the presence of Mg2+ and GTP . The current data suggests that pim1+ acts as a GTP exchanger for the spi1 GTPase. Rev Inst Med Trop Sao Paulo, 1991 Jan-Feb, 33(1), 74 - 9 Subcutaneous phaeohyphomycosis caused by Bipolaris hawaiiensis . A case report; Costa AR et al.; A case of phaeohyphomycosis caused by Bipolaris hawaiiensis is reported . The patient, an immunocompetent host, presented a verrucous lesion on the first finger of the left foot . Dematiaceous septate hyphae and yeast-like elements were seen in direct and histological examination . The isolated strain was identified on the basis of micro and macromorphological aspects . Treated with electrocoagulation, the lesions healed and presented no relapse after two years follow-up. Nucleic Acids Symp Ser, 1991, (25), 149 - 50 Sequence specific purification of a particular tRNA by solid phase DNA probe; Tsurui H et al.; A novel method for the purification of a specific tRNA using solid phase DNA probe is developed . With this method, the probe DNA immobilized on HPLC gel hybridized with target tRNA within a minute at room temperature . The hybridizing capacity of the solid phase probe was about 20 O.D . per gram dry gel when yeast phenylalanine tRNA was used . The specificity of this method was extremely high and the recovery rate was about 90%. DNA Seq, 1991, 1(3), 197 - 206 An H3-H4 histone gene pair in the marine copepod Tigriopus californicus, contains an intergenic dyad symmetry element; Porter D et al.; Histone genes are one of the most widely studied multigene families in eucaryotes . Over 200 histone genes have been sequenced, primarily in vertebrates, echinoderms, fungi and plants . We present here the structure and genomic orientation of an H3-H4 histone gene pair from the marine copepod, Tigriopus californicus . These histone gene sequences are the first to be determined for the class Crustacea and among the first to be determined for protostomes . The H4 and H3 genes in Tigriopus are shown to be adjacent, to have opposite polarity, and to contain a 26 bp region of dyad symmetry centrally located within the spacer region between the two genes . A similarly located dyad element has been found in yeast which contributes to the coordinated cell cycle control of the adjacent histone genes . The Tigriopus H3-H4 histone gene pair is clustered with one H2A and two H2B histone genes on a 15 kb genomic Bam H1 fragment . The H4 gene sequence predicts an H4 protein with an unusual serine to threonine substitution at the amino terminal residue . The H3 gene sequence predicts an H3 protein which is identical to the vertebrate H3.2 histone. Acta Derm Venereol Suppl (Stockh), 1991, 167, 1 - 36 Seborrhoeic dermatitis and Pityrosporum ovale: cultural, immunological and clinical studies; Bergbrant IM; Seborrhoeic dermatitis is a common skin disease mainly affecting the scalp and face . The etiology of seborrhoeic dermatitis is unknown but a connection with the lipophilic yeast Pityrosporum ovale has been found in a number of treatment studies . P . ovale belongs to the normal cutaneous flora but is also an opportunistic pathogen . The purpose of these studies was to examine how the density of P . ovale changes with age, to determine the number of P . ovale in seborrhoeic dermatitis compared to controls, to study the immunological functions in patients with seborrhoeic dermatitis, to evaluate different methods of detecting antibodies against P . ovale and to describe how the patients experience their disease . The number of P . ovale on clinically normal skin decreases with increasing age . In patients with seborrhoeic dermatitis, the number of P . ovale in lesional skin was not increased compared to healthy skin in the patients or in healthy controls . A reduction of the skin surface lipids was seen in elderly healthy individuals . The lipid content on the skin in patients with seborrhoeic dermatitis was higher than in controls (p = 0.0001) . Serum IgG antibodies against P . ovale measured with indirect immunofluorescence decreased parallel to increasing age in healthy individuals and no difference was found between patients with seborrhoeic dermatitis and healthy controls . ELISA with a P . ovale protein extract was the only method that demonstrated a difference in immune response between patients and controls when this method was compared with four other assays (p = 0.03) . Immunological screening was done in 30 patients with seborrhoeic dermatitis . No major abnormalities in the humoral and local immune system were found but T-cell and NK-cell aberrations were found in several patients with seborrhoeic dermatitis . One-third of the patients had low lymphocyte stimulations with Concanavalin-A and phytohaemagglutinin and almost half of the patients had high frequencies of circulating natural killer-cells . In a questionnaire answered by 431 patients with seborrhoeic dermatitis, we found indications that hereditary, the season, mental stress and the work environment influence the disease . The investigations suggest that the number of P . ovale in seborrhoeic dermatitis is of minor importance . How each individual reacts to P . ovale and the amount of skin surface lipids are probably of greater importance in the development of seborrhoeic dermatitis. Int J Technol Assess Health Care, 1991, 7(3), 379 - 402 Cost-benefit analysis of hepatitis-B vaccination . A computerized decision model for Spain; Jonsson B et al.; The availability and efficacy of recombinant deoxyribonucleic acid yeast-derived hepatitis-B vaccine, at a price much lower than the previously available plasma-derived hepatitis-B vaccines against hepatitis-B virus infections, motivate a new cost-benefit analysis of hepatitis-B vaccination . Spanish data were used to calculate direct and indirect costs of hepatitis-B infection and the costs and benefits of different vaccination strategies in defined risk groups of the Spanish population . A vaccination program will reduce direct expenditures for hepatitis B if the attack rate in the target population is higher than 4.9% . If indirect costs are included, the threshold for cost saving is reduced to 0.9% . The results are sensitive to the price of the vaccine, the duration of protection, assumptions about consequences for quality of life, and to indirect costs. J Cell Sci Suppl, 1991, 14, 143 - 5 Dynamin: a microtubule-associated GTP-binding protein; Obar RA et al.; We recently identified dynamin as a third nucleotide-sensitive microtubule-associated protein in brain tissue, in addition to kinesin and cytoplasmic dynein . Molecular cloning analysis has revealed that dynamin contains the three consensus elements characteristic of GTP-binding proteins, and biochemical results support a role for GTP in dynamin function . Dynamin is also homologous to the Mx proteins, involved in interferon-induced viral resistance, and the product of the yeast VPS1 gene, involved in vacuolar protein sorting . These results identify a novel class of GTP-utilizing proteins, with apparently diverse functions. EXS, 1991, 58, 50 - 69 Oligonucleotide fingerprinting using simple repeat motifs: a convenient, ubiquitously applicable method to detect hypervariability for multiple purposes; Epplen JT et al.; A panel of simple repetitive oligonucleotide probes has been designed and tested for multilocus DNA fingerprinting in some 200 fungal, plant and animal species as well as man . To date at least one of the probes has been found to be informative in each species . The human genome, however, has been the major target of many fingerprinting studies . Using the probe (CAC)5 or (GTG)5, individualization of all humans is possible except for monozygotic twins . Paternity analyses are now performed on a routine basis by the use of multilocus fingerprints, including also cases of deficiency, i.e . where one of the parents is not available for analysis . In forensic science stain analysis is feasible in all tissue remains containing nucleated cells . Depending on the degree of DNA degradation a variety of oligonucleotides are informative, and they have been proven useful in actual case work . Advantages in comparison to other methods including enzymatic DNA amplification techniques (PCR) are evident . Fingerprint patterns of tumors may be changed due to the gain or loss of chromosomes and/or intrachromosomal deletion and amplification events . Locus-specific probes were isolated from the human (CAC)5/(GTG)5 fingerprint with a varying degree of informativeness (monomorphic versus truly hypervariable markers) . The feasibility of three different approaches for the isolation of hypervariable mono-locus probes was evaluated . Finally, one particular mixed simple (gt)n(ga)m repeat locus in the second intron of the HLA-DRB genes has been scrutinized to allow comparison of the extent of exon-encoded (protein-) polymorphisms versus intronic hypervariability of simple repeats: adjacent to a single gene sequence (e.g . HLA-DRB1*0401) many different length alleles were found . Group-specific structures of basic repeats were identified within the evolutionarily related DRB alleles . As a further application it is suggested here that due to the ubiquitous interspersion of their targets, short probes for simple repeat sequences are especially useful tools for ordering genomic cosmid, yeast artificial chromosome and phage banks. Folia Microbiol (Praha), 1991, 36(2), 198 - 204 The immunoadjuvant effect of soluble glucan derivatives in mice; Wagnerova J et al.; We examined the effect of soluble derivatives of yeast glucan on the humoral immune response of various strains of inbred mice after administration of different doses according to various schedules . Glucan was injected i.v . or s.c . in a single dose or repeatedly . The immune response was examined by determining the titres of serum hemagglutinins against sheep erythrocytes (SRBC-Ab) . The immunoadjuvant effect of glucan derivatives depends on the inbred strain used, on the dose of glucan, mode and time of administration with respect to antigen injection . The results have shown that the stimulatory effect of glucan derivatives occurred already after a single injection, the optimum dose being 10-20 mg/kg . Intravenous injection was more efficient than the subcutaneous one . In some cases, a slight increase of the spleen mass was observed. Folia Microbiol (Praha), 1991, 36(2), 148 - 52 Sterol composition of nystatin-resistant Candida maltosa mutants; Mikhailova NP et al.; Composition of sterol fractions of nystatin-resistant Candida maltosa strains was determined . Using UV-spectrometry, TLC and GLC-MS it was demonstrated that resistance to nystatin is connected with the composition alterations of yeast cell sterols . Block of different stages of ergosterol biosynthesis was revealed in some mutants, viz . C-24-transmethylation, delta 8----delta 7-isomerization, 14 alpha-demethylation, C-5(6)-dehydrogenation, reduction of C-14(15) and C-24(28) double bonds. Folia Microbiol (Praha), 1991, 36(4), 406 - 7 A rapid and simple method for DNA preparation from Candida utilis; Krizkova L et al.; A method for the extraction of genomic DNA from the industrial yeast Candida utilis is described . The method is rapid, simple and produces DNA that is sufficiently pure for restriction analysis and should be suitable for Southern blotting and the construction of gene libraries. Folia Microbiol (Praha), 1991, 36(4), 367 - 74 Effect of pH and organic matter on the toxicity of heavy metals to growth of some fungi; Bagy MM et al.; Increasing the pH from 5 to 9 decreased the toxicity of mercuric chloride, zinc sulfate, lead nitrate, copper sulfate and nickel chloride toward the growth of Aspergillus flavus, Penicillium chrysogenum, Cunninghamella echinulata, Myrothecium verrucaria and Phoma humicola . On the other hand, the toxicity of cadmium chloride was increased by the increasing pH . Also increasing the concentration of organic matter (peptone and yeast extract) from 0.5 to 1.5% induced a significant reduction in the toxicity of all heavy metals toward the growth of all test fungi. Folia Microbiol (Praha), 1991, 36(4), 343 - 6 Production of laccase by Curvularia sp; Banerjee UC et al.; A Curvularia sp . isolated from soil was found to contain laccase activity toward guaiacol as substrate . The organism produced an extracellular laccase in a medium containing yeast extract, peptone and dextrose . Initial medium pH 4.0 and cultivation temperature 30 degrees C were found to be most suitable for maximum enzyme production . The optimum pH and temperature for laccase activity were found to be 5.2 and 50 degrees C, respectively . Under optimum conditions, the enzyme had a Km (guaiacol) of 0.75 mmol/L and a V of 1.50 CU min-1 ml-1 . Some divalent metal ions inhibited laccase activity at very low concentrations. IARC Sci Publ, 1991, (115), 113 - 7 Comparative acute nephrotoxicity of Penicillium aurantiogriseum in rats and hamsters; Hard GC et al.; Air-dried mycelium of Penicillium aurantiogriseum2, grown as a surface culture on yeast extract-sucrose medium, was incorporated into powdered diet and fed to rats and hamsters for different periods up to 28 days . At intervals, animals were anaesthetized and the kidneys fixed in situ by perfusion . In rats, the fungus produced scattered exfoliation of pyknotic cells and an increased frequency of mitotic figures involving the pars recta segment of proximal tubular epithelium . This lesion was detectable as early as three days after beginning of treatment and was well developed by 14 days . No degenerative tubular change or mitogenic effect was observed in hamsters, even after feeding for 35 days; and there was no apparent renal pelvic or interstitial lesion in either species. Arch Invest Med (Mex), 1991 Jan-Mar, 22(1), 35 - 40 Human leukocyte migration inhibition factor (LIF) increases polymorphonuclear cell endocytosis; Cortes-Castillo MA et al.; We prepared supernatants of Concanavalin-A activated human lymphocytes containing high titers of leukocyte migration inhibition factor (LIF) . A pool of these supernatants was filtered thorough sephadex 6-100 as well as a pool of supernatants from parallel non activated cultures . A migration assay was carried out for each activated fraction, using as control migration the same fraction from non activated supernatants . In this way we found a fraction from activated supernatants with high LIF activity . We assayed the effect of this LIF containing fraction on a yeast endocytosis assay by polymorphonuclear (PMN) cells . We found that the LIF containing fraction increased the number of endocytic PMN in about 80% . This effect was absent from control supernatant and from other fractions from activated supernatant but without LIF activity . The LIF containing fraction did not increase the average number of endocytosed yeast per cell nor the ability to reduce NBT . The endocytosis enhancing effect was blocked by the specific LIF blocker N-acetyl-D-glucosamine . We conclude that LIF can increase the endocytic activity of PMN cells. Cytobios, 1991, 68(273), 77 - 83 Effect of parvalbumin and S-100 protein on protein synthesis in rabbit reticulocyte lysate; Cheema IR et al.; The effect of two high affinity Ca+ binding acidic proteins, parvalbumin and S-100 protein on protein synthesis in rabbit reticulocyte lysates (RRL), was investigated . Nuclease-treated RRL, supplemented with yeast mRNA, and 3H-leucine were incubated at 37 degrees C, and incorporation of 3H-leucine into protein was determined for 24 min . At 20 micrograms/100 microliters lysate concentration, both parvalbumin and S-100 protein caused a marked inhibition of protein synthesis compared with the control lysate . At a lower concentration parvalbumin was less inhibitory than histone H1; the effect of S-100 protein was not significant . The combined inhibitory effect of parvalbumin and H1 was not additive probably due to strong interaction between them as was evidenced by the enhanced absorbance of parvalbumin-H1 mixture . Spectrophotometric profiles of parvalbumin-tRNA mixture indicated that, unlike H1, parvalbumin did not inhibit protein synthesis by binding with nucleic acids . These results suggest an important role for parvalbumin in translational regulation. C R Seances Soc Biol Fil, 1991, 185(5), 290 - 305 {Protein farnesyl and geranylgeranyl transferases}; de Gunzburg J; Posttranslational prenylation of proteins synthesized as soluble precursors enhances their hydrophobicity and enables them to bind biological membranes . These modifications consist in the attachment of a C15 farnesyl or a C20 geranylgeranyl moiety to the cysteine residue(s) of proteins bearing CAAX, CC or CXC C-terminal sequences (where C = cysteine, A = aliphatic residue and X = any amino-acid), such as proteins of the ras superfamily, gamma subunits of heterotrimetric G proteins, lamin B as well as yeast mating factor a . A farnesyl transferase (FTase) and two distinct geranylgeranyl transferases (GGTases I and II) have been recently identified . FTase and GGTase I modify proteins containing a C-terminal CAAX motif; such a sequence is necessary and sufficient for recognition by the enzymes . The nature of the fourth residue determines the nature of the modification: when X is a serine, a methionine or a phenylalanine, the protein is farnesylated, whereas the presence of a leucine residue results in the attachment of a geranylgeranyl group . Both these enzymes are alpha beta heterodimers; their purification, molecular cloning of their coding sequences as well as mutational studies in yeast have shown that they share a common alpha subunit, and that their beta subunits exhibit a significant level of sequence similarity . GGTase II modifies ras-related proteins exhibiting CC and CXC C-terminal sequences; the enzyme as well as its recognition motif are yet largely uncharacterized. Histol Histopathol, 1991 Jan, 6(1), 107 - 13 Ultrastructural changes induced by alpha-sarcin in a human pulmonary tumor grown in naked mice; Mohamed-Ali H et al.; alpha-Sarcin is a cytotoxic polypeptide produced by Aspergillus giganteus . It suppresses protein synthesis in yeast and wheat germ extracts and has a purine-specific RNase activity . The substance has been tested for its antitumor properties in a series of induced tumor systems in mice such as sarcoma and carcinoma among others . Although some of the in vitro effects of alpha-Sarcin on certain cellular components have been elucidated, the biological effects leading to cellular damage are still obscure . In this work we analysed the morphological changes in tumor cells derived from human pulmonary adenocarcinoma heterotransplanted and grown in naked mice, induced shortly (24 hours) after a single intratumoral injection of alpha-Sarcin (0.4 mg/tumor) . The results obtained were: 1) swelling of mitochondria; 2) cell necrosis with partial removal of necrotic cells by phagocytosis; 3) thickening of interlobular connective tissue; 4) hyperplasia of goblet-cell-like clear cells . The mode of action concerning these cellular changes is presently uncertain . In view of the severity of these structural alterations it seems conceivable that alpha-Sarcin may enter the cell undergoing interactions with different intracellular structures . This would require a selective membrane permeabilization, perhaps induced upon formation of complexes with negatively-charged membrane phospholipids. Rocz Panstw Zakl Hig, 1991, 42(1), 1 - 7 {Histamine and tyramine levels in selected food products}; Gajewska R et al.; Histamine and tyramine contents were determined in parallel in fish and fish products ripening and processed cheese, yeast, wine, cabbage and sauerkraut, and tomato paste . Histamine was assayed by the colorimetric method of Hardy and Smith, and by TLC . Tyramine was determined by TLC . Levels of histamine and tyramine were found to be low in all products tested . For histamine and tyramine, respectively, they amounted: in raw fish to 0.0-8.0 and 0.0-2.6 mg/100 g, in fish products to 0.0-16.0 and 0.0-10.0 mg/100 g, and in cheeses to 0.0-0.8 and 1.3-20.0 mg/100 g . In the remaining food products (tomato paste, yeast, wine, cabbage and sauerkraut), histamine content was between 0.0-16.6 mg/100 g (highest in tomato paste), and tyramine content fluctuated between 0.0-8.0 mg/100 g (highest in sauerkraut). Int J Immunopharmacol, 1991, 13(5), 501 - 8 Effect of saikosaponin on the immune responses in mice; Ushio Y et al.; The in vivo effects of saikosaponin, isolated from Bupleurum radix, on the immune responses are still poorly understood . We have already shown that saikosaponin-d increases phagocytic activities of murine peritoneal macrophages such as spreading activity, phagocytosis, lysosomal enzyme activity and intracellular killing activity of living yeast . This work extends these observations by showing that treatment with saikosaponin also increased the antibody response in plaque-forming cell numbers after in vivo immunization with sheep red blood cells (SRBC) and an augmentation of spleen cell proliferation responses to stimulation with T- or B-cell mitogens both before and after immunization . Furthermore, after SRBC immunization, the macrophages from mice treated with saikosaponin-d revealed significant increases in spreading activity and lysosomal enzyme activity . The chemiluminescences of the macrophages from mice treated with saikosaponin-d stimulated by opsonized zymosan and PMA were enhanced and interleukin-1 production by the cells was increased in a dose-dependent manner . These results demonstrate that saikosaponin-d may stimulate in vivo immunological lymphocyte functions, partly by activating some macrophage functions. DNA Seq, 1991, 2(2), 133 - 5 Nucleotide sequence of a human heart cDNA encoding the mitochondrial phosphate carrier; Dolce V et al.; We have isolated and characterized a full length cDNA clone encoding the precursor of the human heart mitochondrial phosphate carrier protein . The entire clone is 1330 bp in length with 5'- and 3'-untranslated regions of 48 and 184 bp, respectively . The open reading frame encodes the mature protein consisting of 312 amino acids, preceded by a presequence of 49 amino acids . The amino acid sequence of the mature human phosphate carrier is 93.6, 94.2 and 33.6% identical to that of the phosphate carrier from beef, rat and yeast, respectively . Like other mitochondrial transport proteins, the human phosphate carrier has a tripartite structure . Each of the three repeats contains two hydrophobic regions which presumably span the membrane in the form of alpha-helices. Nephrol Dial Transplant, 1991, 6 Suppl 3, 35 - 40 Phagocytosis activity of polymorphonuclear cells of normal persons and dialysis patients is influenced by different dialysis membranes; Schauer S et al.; Leukocyte (PMN) functional capacity has been investigated through evaluation of phagocytosis of opsonised yeast cells in a radiometric test system . The PMN of dialysis patients (DP) had a slightly lower ability to ingest opsonised yeast cells in comparison with normal persons (NP), suggesting that an intrinsic cellular defect may exist . Under the influence of six membranes (cellulose acetate, regenerated cellulose, modified cellulose, cuprophane, polysulphone, and polymethylmethacrylate) the phagocytosis index decreased significantly between 10 and 17% in NP and between 13 and 23% in DP . There is a clear correlation with the membrane surface area . These results are not explained by the number of dead leukocytes (4-6.5% in DP and also in NP independently of membrane contact) . The direct membrane effect could be responsible for the diminished phagocytic activity of leukocytes in NP and DP . Aqueous extracts of membranes alone resulted in no change of the phagocytic ability of PMN . Extracellular or 'uraemic factors' were excluded by the test procedure . The killing rate of yeast cells by PMN in NP and DP was not influenced in any of the membranes tested. Doc Ophthalmol, 1991, 77(3), 185 - 92 Longitudinal measures in children receiving ENCAD for hereditary retinal degeneration; Birch DG et al.; A hydrolysate of yeast RNA (ENCAD) is used in the Soviet Union for the treatment of hereditary retinal degenerations . We report longitudinal data from three young patients who have made at least two visits to the Soviet Union over a five-year period to receive treatment with ENCAD . Two children were diagnosed with cone-rod degeneration and the third has an isolated (simplex) form of retinitis pigmentosa . Visual function measurements were obtained before and after each visit to Moscow . In the comparison of previsit and postvisit visual acuity, 30 Hz flicker amplitude, and visual fields, ENCAD treatment had no significant short-term effect . Despite treatment with ENCAD, each patient has shown a significant decrease in visual function over the 5-year period . The rate of progression in these patients appears similar to previously published data on the natural history of their retinal degenerative disorders. Acta Otolaryngol, 1991, 111(5), 943 - 5 Is Pityrosporum ovale a pathogen of the external auditory meatus? Stenfors LE, Raisanen S. Fifteen dry wax samples, 15 wet wax samples and 7 dandruffy skin samples obtained from the external auditory meatus (EAM) of 26 individuals (age range from 1 to 76 years) were examined for the identification of Pityrosporum ovale . After staining the samples with Gram's stain, cultures were made on Sabouraud's medium with olive oil added . Thirteen of the dry wax samples, 1 of the wet wax samples and 6 of the dandruffy skin samples harboured P . ovale . Lipophilic yeast is frequently present in dry wax in adults and must be considered an aetiological agent of dandruff in the EAM. Biotechnol Ther, 1991, 2(1-2), 63 - 89 Importance of conformation on the neutralizing antibody response to HIV-1 gp120; Steimer KS et al.; We have investigated the role of conformation of HIV-1 gp120 on its potential efficacy as a subunit vaccine . The questions that we set out to answer were: 1) Are there neutralizing antibodies directed to conformational epitopes in gp120? 2) If so, what is the spectrum of virus isolates neutralized by these antibodies? 3) Is a conformationally correct gp120 subunit more effective in the induction of neutralizing antibodies than a denatured subunit? 4) Does native gp120 subunit vaccination induce a broader neutralizing response than a gp120 antigen that cannot display conformational epitopes? To address these questions, we characterized the gp120-specific antibody response of HIV-1-infected humans and of experimental animals immunized with recombinant native and nonnative gp120 subunits . Two versions of recombinant gp120 produced from the HIV-SF2 isolate of HIV-1 were employed in these studies: 1) a nonglycosylated, denatured version produced in genetically engineered yeast, which we presume is capable of presenting only linear determinants, and 2) a fully glycosylated, native version, produced in genetically engineered mammalian cells, that is capable of displaying linear as well as conformational epitopes . Antibodies directed exclusively to conformational epitopes in gp120 were purified from pooled HIV antibody-positive human sera using these two versions of HIV-SF2 gp120 . These antibodies exhibited neutralizing activity, and this activity was effective in the neutralization of a different, broader spectrum of HIV-1 isolates than that of antibodies to linear determinants in gp120 purified from the same serum pool . When these two versions of HIV-SF2 gp120 were used as subunit immunogens in baboons, clear differences in their abilities to elicit neutralizing antibodies were observed . The native version was more effective in the induction of neutralizing antibodies effective against HIV-SF2, the homologous virus isolate . The isolate specificity of the neutralizing response to these two versions of HIV-SF2 gp120 also differed . The nonglycosylated version induced neutralizing antibodies that were effective against only the isolate, or closely related isolates, from which the antigen was derived . In contrast, the native version induced a neutralizing response that was effective against a broad panel of HIV-1 isolates, including at least one isolate that one would not expect to be neutralized by antibodies to the PND of HIV-SF2 gp120. Symp Soc Exp Biol, 1991, 45, 57 - 62 Development of a system for efficient chromosome walking in Arabidopsis; Grill E et al.; The small genome size of Arabidopsis and the low level of repetitive DNA sequences make this crucifer an attractive system for chromosome walking to isolate genes . Mapping of a mutant locus relative to restriction fragment length polymorphism (RFLP) markers provides the first step towards isolating the corresponding gene . The RFLP marker closest to the target gene serves as a starting point . The distance between gene and marker is generally in the range of 50-200 kb . In order to facilitate chromosome walking of this magnitude, we constructed a yeast artificial chromosome (YAC) library of Arabidopsis . Large fragments of Arabidopsis DNA were cloned into a YAC vector and transformed into yeast . The library contains more than 10 equivalents of the Arabidopsis genome . YACs containing sequences of RFLP markers of Arabidopsis revealed an average insert size of 150 kb . Thus, 1-3 (contiguous) YACs should be sufficient to clone genes from Arabidopsis by chromosome walking . In order to use the system to isolate genes involved in the signal transduction of abscisic acid, we fine-mapped the mutant loci abi-1 and abi-2, which confer abscisic acid insensitivity, relative to RFLPs and isolated the corresponding YACs. Comp Biochem Physiol C, 1991, 100(3), 389 - 96 Isolation, partial purification, and characterization of the cytochrome P-450-dependent monooxygenase system from the midgut of the earthworm Lumbricus terrestris; Berghout AG et al.; 1 . Cytochrome P-450 was purified from microsomes of the midgut of the earthworm Lumbricus terrestris up to a maximal specific content of 5.5 nmol P-450/mg protein . 2 . At least 3 different cytochromes P-450 with apparent molecular weights of 48,000, 51,000 and 53,000 were identified by SDS-PAGE . 3 . Western blot analysis with various polyclonal antibodies did not show structural epitopes common to the cytochromes P-450 of rodents or yeast and L . terrestris . 4 . The microsomes contained about 43 pmol P-450/mg protein corresponding to 0.51 nmol P-450/g midgut and 64 pmol P-450/g body weight, respectively, and converted benzyloxyresorufin into resorufin with a Vmax of 2.12 pmol resorufin/min.mg protein and a Km of 770 nM benzyloxyresorufin at 25 degrees C, pH 8.0 . 5 . The microsomes exhibited a NADPH-cytochrome P-450 reductase activity of 9.4 nmol cytochrome c/min.mg protein . 6 . The apparent molecular weight of the threefold-purified reductase was 63,000. Prog Clin Biol Res, 1991, 362, 33 - 66 The molecular genetics of retinal photoreceptor proteins involved in cGMP metabolism; Pittler SJ et al.; Metabolism of cGMP is critically important for the functioning of phototransduction in the mammalian retina . In rod and cone photoreceptors, two types of antagonistic enzymes, guanylate cyclases and cGMP phosphodiesterases, carefully balance the available amount of the intracellular messenger . Guanylate cyclase produces cGMP and phosphodiesterase rapidly hydrolyzes cGMP upon bleaching of the photopigment . Regulation of their activity in light and dark, influence of Ca++, and feed-back mechanisms are currently under intense investigation . A molecular analysis on both the gene and protein levels will contribute significantly to our understanding of their respective roles in phototransductio