Antibiot Med Biotekhnol, 1985 May, 30(5), 337 - 41 {Resistance to organic tin compounds mediated by plasmids of bacteria of Pseudomonas genus}; Anisimova LA et al.; Resistance to organic tin compounds of P . aeruginosa and E . coli carrying antibiotic resistance plasmids and to P . putida containing biodegradation plasmids was studied . It was shown that 5 resistance plasmids and the biodegradation CAM plasmid of Pseudomonas increased 3-4 times the strain resistance to triethylstannylsuccinylimide and triethylstannylmaleinimide . All these plasmids belong to the P-2 incompatibility group and also determine the bacterial resistance to potassium tellurite . Isolation and investigation of the mutant plasmids loosing simultaneously the capacity for determination of resistance to potassium tellurite and organic tin compounds suggest that resistance to these compounds in the investigated plasmids is determined by the same genetic system. Biochem Soc Trans, 1985 Apr, 13(2), 516 - 20 The use of controlled-release glass for the controlled delivery of bioactive materials; Drake CF et al.; CRG can provide a useful supplement to other methods of controlled delivery . Some advantages of this approach are: The constituents of the CRG can be limited to biologically safe ionic species such as Na+, Ca2+ and PO4(3-) . The release system is completely soluble in water and no residue remains . There is no evidence of any mechanism for biodegradation of the CRG and so one possible cause of premature or accelerated release is eliminated . The absolute release rate can be selected anywhere in a spectrum covering several orders of magnitude and the rate-controlling process has zero-order kinetics . The release rate can be selected to be pH-sensitive or pH-independent . Complex temporal release-rate patterns can be obtained readily by the choice of geometrical shape or composition profile of the device . The controlled release of organics or other heat-sensitive materials which cannot be incorporated in the glass can be realized by the use of composite structures in which the CRG is the rate-controlling constituent . A number of different functions can be performed by a single CRG-based device . For example, CRG can be used as a biomedical resorbable material in surgery and the CRG structural component can release an AM as it dissolves . Similarly the CRG of the sinter-composite used for organic AM release can itself release any selected inorganic adjuvant . CRG boluses containing either copper or cobalt and weighing approx . either 70 g or 15 g, have been administered to both cattle and sheep . More than 90% of the boluses remained either in the reticulum of trace element remained after dosing.(ABSTRACT TRUNCATED AT 250 WORDS) Appl Environ Microbiol, 1985 Apr, 49(4), 867 - 9 Biodegradation of {14C}phenol in secondary sewage and landfill leachate measured by double-vial radiorespirometry; Deeley GM et al.; Double-vial radiorespirometry was used to estimate the biodegradation rates of 14C-labeled phenol in a landfill leachate and a secondary treated domestic wastewater . Rates were found to be comparable for each material at each of the three concentrations tested . Sewage microorganisms immediately began biodegrading the {14C}phenol; landfill leachate microorganisms required a lag period before maximum biodegradation of the {14C}phenol . The apparent rate of {14C}phenol biodegradation was 2.4 times faster in the sewage than in the landfill leachate . Double-vial radiorespirometry was shown to be an effective method for screening biodegradation rates in aquifers. Ecotoxicol Environ Saf, 1985 Apr, 9(2), 159 - 70 Formation and fate of bound residues of {14C}benzene and {14C}chlorobenzenes in soil and plants; Scheunert I et al.; Outdoor experiments with {14C}hexachlorobenzene, {14C}pentachlorobenzene, {14C}1,2,4-trichlorobenzene, and {14C}benzene in soil-crop systems indicate that the formation rate of bound residues in soil and plants, expressed as bound residues in percentage of total residue in the sample, decreases with increasing number of chlorine in the molecule and, thus, with increasing chemical stability . The time course of formation and fate of bound residues in soil and plants is characterized by a very slow decrease of residue levels in soil, indicating that biodegradation of bound residues hardly exceeds their reformation from the parent compound during one vegetation period, and by a decrease of residue levels in plants . The portion of bound residues as compared to the total residue increases with time, indicating that bound residues are more persistent than the parent compounds and their soluble metabolites; benzene is an exception . Cress plants, in general, contain less bound residues than do barley plants . Again, benzene is an exception . In deeper soil layers, soil-bound residues occur also . The ratio between bound and extractable residues does not differ to a larger extent between the soil layers. Genetika, 1985 Apr, 21(4), 522 - 9 {Plasmids for naphthalene biodegradation incompatible with IncP-2 and IncP-7 group plasmids}; Kochetkov VV et al.; Fourteen conjugative naphthalene degradative plasmids have been classified by incompatibility . It is shown that the plasmids of IncP-9 group are characterized by the minor entry exclusion, with respect to the R plasmids belonging to IncP-2 or IncP-7 groups . On the other hand, the naphthalene degradative plasmids of incompatibility group P-7 exhibit a markedly pronounced entry exclusion, with respect to the R plasmids of the same incompatibility groups . Two naphthalene degradative plasmids reveal incompatibility with the reference plasmids of two Inc groups (P-2 and P-7) . These plasmids control also resistance of bacterial cells to potassium tellurite, which is characteristic of the IncP-2 plasmids . Two other naphthalene degradative plasmids are capable of stable coexistence with the IncP-2, P-7 or P-9 reference plasmids. J Biomed Mater Res, 1985 Mar, 19(3), 349 - 65 Biodegradation of and tissue reaction to 50:50 poly(DL-lactide-co-glycolide) microcapsules; Visscher GE et al.; The biodegradation of the copolymer 50:50 poly(DL-lactide-co-glycolide)-lypressin microcapsules was studied by light and electron microscopic methods and 14C release . Intramuscular injection sites of microcapsules in rats were studied by dissecting and conventional light microscopy as well as scanning (SEM) and transmission electron microscopy . A minimal localized acute myositis was seen initially at the injection sites . By Day 4, a few small foreign body giant cells were present participating in the minimal foreign body response . Later the inflammatory cells decreased and the individual microcapsules were walled off by immature fibrous connective tissue and large syncytial foreign body giant cells . By Day 35, definitive changes in some microcapsules, consisting of a granular and slightly eroded appearance of the internal matrix, were seen by SEM . By Day 42, the outer rims of the microcapsules were extensively eroded . At Day 56, the inflammatory and connective tissue reactions were almost completely resolved and biodegradation continued so that only remnant pieces of the microcapsules were present at Day 63 . The morphologic picture correlated well with loss of 14C radioactivity, which could no longer be detected at the injection sites on Day 56 . Phagocytosis did not seem to be an important factor in the biodegradation. Biosci Rep, 1985 Mar, 5(3), 189 - 204 Regulation of polyamine biosynthesis by antizyme and some recent developments relating the induction of polyamine biosynthesis to cell growth . Review; Canellakis ES et al.; This review considers the role of antizyme, of amino acids and of protein synthesis in the regulation of polyamine biosynthesis . The ornithine decarboxylase of eukaryotic cells and of Escherichia coli can be non-competitively inhibited by proteins, termed antizymes, which are induced by di- and poly- amines . Some antizymes have been purified to homogeneity and have been shown to be structurally unique to the cell of origin . Yet, the E . coli antizyme and the rat liver antizyme cross react and inhibit each other's biosynthetic decarboxylases . These results indicate that aspects of the control of polyamine biosynthesis have been highly conserved throughout evolution . Evidence for the physiological role of the antizyme in mammalian cells rests upon its identification in normal uninduced cells, upon the inverse relationship that exists between antizyme and ornithine decarboxylase as well as upon the existence of the complex of ornithine decarboxylase and antizyme in vivo . Furthermore, the antizyme has been shown to be highly specific; its Keq for ornithine decarboxylase is 1.4 X 10(11) M-1 . In addition, mammalian cells contain an anti-antizyme, a protein that specifically binds to the antizyme of an ornithine decarboxylase-antizyme complex and liberates free ornithine decarboxylase from the complex . In E . coli, in which polyamine biosynthesis is mediated both by ornithine decarboxylase and by arginine decarboxylase, three proteins (one acidic and two basic) have been purified, each of which inhibits both these enzymes . They do not inhibit the biodegradative ornithine and arginine decarboxylases nor lysine decarboxylase . The two basic inhibitors have been shown to correspond to the ribosomal proteins S20/L26 and L34, respectively . The relationship of the acidic antizyme to other known E . coli proteins remains to be determined . In mammalian cells, ornithine decarboxylase can be induced by a broad spectrum of compounds . These range from hormones and growth factors to natural amino acids such as asparagine and to non-metabolizable amino acid analogues such as alpha-amino-isobutyric acid . The amino acids that induce ornithine decarboxylase as well as those that promote polyamine uptake utilize the sodium dependent A and N transport systems . Consequently, they act in concert and increase intracellular polyamine levels by both mechanisms . The induction of ornithine decarboxylase by growth factors, such as NGF, EGF, and PDGF as well as by insulin requires the presence of these same amino acids and does not occur in their absence . However, the inducing amino acid need not be incorporated into protein nor covalently modified.(ABSTRACT TRUNCATED AT 400 WORDS) J Biomed Mater Res, 1985 Mar, 19(3), 293 - 301 In vivo corrosion of sodium silicate glasses; Pernot F et al.; Square-shaped implants of various sodium silicate glasses were weighed and implanted intraperitoneally in rat for periods ranging from 8 to about 60 days . The implants were then removed and their aspect was compared to their aspect before exposure to physiological environment . The corrosion products were studied by x-ray diffraction and electron microprobe analysis . Weight changes were also measured to calculate a biodegradation rate . The glass 66 SO (66.6 SiO2-33.3 Na2O) was strongly corroded, as early as after the first week . The nonsoluble degradation products formed a cocoon encapsulating the now smaller specimen . The analysis of the cocoon showed that it was made of a silica-rich layer containing also calcium and phosphorus . In this layer the ratio Ca/P could correspond to that of an apatite . The biodegradation rate reached 71 x 10(-4) g . cm-2 . day-1 . The glass 75 SO (75 SiO2-25 Na2O) was not so quickly corroded: Cracks appeared at the surface and progressively reached the center of the implants . There was no removable shell but a white deposit, adherent to the surface . This deposit contained silica and also calcium and phosphorus at the periphery . The biodegradation rate was only 2.6 x 10(-4) g . cm-2 . day-1. Biochem J, 1985 Mar 1, 226(2), 455 - 60 Free hydroxyl radical is not involved in an important reaction of lignin degradation by Phanerochaete chrysosporium Burds; Kirk TK et al.; Hydroxyl radical (HO.) has been implicated in the degradation of lignin by Phanerochaete chrysosporium . This study assessed the possible involvement of HO . in degradation of lignin substructural models by intact cultures and by an extracellular ligninase isolated from the cultures . Two non-phenolic lignin model compounds {aryl-C(alpha)HOH-C(beta)HR-C(gamma)H2OH, in which R = aryl (beta-1) or R = O-aryl (beta-O-4)} were degraded by cultures, by the purified ligninase, and by Fenton's reagent (H2O2 + Fe2+), which generates HO. . The ligninase and the cultures formed similar products, derived via an initial cleavage between C(alpha) and C(beta) (known to be an important biodegradative reaction), indicating that the ligninase is responsible for model degradation in cultures . Products from the Fenton degradation were mainly polar phenolics that exhibited little similarity to those from the biological systems . Mass-spectral analysis, however, revealed traces of the same products in the Fenton reaction as seen in the biological reactions; even so, an 18O2-incorporation study showed that the mechanism of formation differed . E.s.r . spectroscopy with a spin-trapping agent readily detected HO . in the Fenton system, but indicated that no HO . is formed during ligninase catalysis . We conclude, therefore that HO . is not involved in fungal C(alpha)-C(beta) cleavage in the beta-1 and beta-O-4 models and, by extension, in the same reaction in lignin. Ecotoxicol Environ Saf, 1985 Feb, 9(1), 6 - 16 A respirometric method for the assessment of ready biodegradability: results of a ring test; Painter HA et al.; A collaborative exercise involving twelve laboratories was organized for the European Economic Community to check the validity of an enclosed respirometric method for assessing the ready biodegradability of test chemicals, including insoluble substances . The method, based partly on the OECD-Japanese Ministry of International Trade and Industry (MITI) I method (301C) and partly on the U.K . method, allowed the use of a less restrictive, natural inoculum and a wider variety of respirometers than the original MITI I method . Eight compounds of a wide range of degradative behavior were tested over an incubation period of 28 days . The agreement between participating laboratories in the lag period before biodegradation started and in the proportions of theoretical oxygen uptake achieved was at least as good as in other ring tests; it is proposed that the method be accepted . Differences in behavior of pentaerythritol reported here and in the literature are examined and suggestions for future study are discussed. Langenbecks Arch Chir, 1985, 363(4), 273 - 82 {Regeneration of the trachea following partial or total replacement by synthetic resorbable material (polyglactin 910)}; Greve H et al.; Though longer distances of the trachea and segments of the bronchi can be resected and the blunts be joined by end-to-end anastomosis, the replacement of parts of the wall of the tracheobronchial tree may become necessary . Alloplastic not absorbable material like silicone was not successful because of its disposition to infections and development of stenosis . Absorbable suture material proved to be suitable in tracheal surgery and it was shown that texture of Polyglactin 910 (Vicryl) could even be used for replacement of the aortic wall . We used weaved tubes of 2.5 mm diameter as prostheses of this material . We partly resected the trachea in the throat of 30 rats and in a microsurgical procedure we replaced in 17 animals the whole circumference by the tube shaped prosthesis and in 13 animals a window in the trachea by a patch, cut from such a prosthesis . By pneumonia or granulation in the anastomosis region 11 rats died or had to be sacrificed untimely . The others survived in several periods up to 10 weeks . At the time of autopsy starting after 3 weeks, a newly formed trachea could be demonstrated, which is covered more and more with respiratory epithelium . By light microscopic and scanning microscopic examinations, the development of a new wall, similar to the normal one, was seen . This wall lacks only mucus glands, but contains structures similar to hyaline cartilage . Our absorbable prosthesis cannot prevent the development of stenosis by overshooting granulation in the early postoperative period, but very soon the material is absorbed and replaced by a structure similar to the normal wall . After biodegradation, problems appear by instability of the new tissue, because of collapsing during inspiration . This problem could be solved by covering the prosthesis by an additional supporting scaffold. Biopharm Drug Dispos, 1985 Jan-Mar, 6(1), 91 - 104 Adriamycin-loaded albumin microspheres: preparation, in vivo distribution and release in the rat; Willmott N et al.; Adriamycin-loaded bovine albumin microspheres have been prepared by a technique that allows preparation and administration to animals on the same day . Criteria adopted for injection were that microspheres should be stable and of a size such as to become trapped in capillary beds . These conditions were fulfilled by preparing microspheres using glutaraldehyde concentrations greater than 0.5 per cent and the appropriate combination of stirring speed and continuous phase viscosity . After systemic administration rats were sacrificed at intervals and major visceral organs examined for entrapped microspheres and serum for released drug . Microspheres sieved out in the first capillary bed encountered, the lung, then following biodegradation they disappeared at a rate dependent on the amount of cross-linking agent used in their preparation . In contrast to bolus injection, serum drug levels after microsphere administration indicated an initial rapid release followed by a more protracted phase lasting at least 24 h . This latter observation is consistent with drug release during biodegradation of carrier. Z Kardiol, 1985, 74 Suppl 6, 65 - 71 Temporary left heart bypass and total artificial replacement; Bucherl ES; Research into left heart assistance was initiated in Berlin in the 1960s with a small implantable pump between the left atrium and the aorta with an extracorporeal driving unit . From thereon, different blood pumps were developed from different materials, the latest types being made out of polyurethanes . Similar designs are used for the total artificial heart . Longest function times exceed 200 days, partly with problems similar to those of the artificial heart . Total artificial heart research began in 1962 . The present system consists of 2 polyurethane blood pumps divided by 3 membranes into blood and energy transmission chambers . The longest testing function time is now more than 2 years . The outside driving units of different sizes and designs are connected with tubes and special quick connectors to the right and left atrium, aorta and pulmonary artery . Air capsulae for pressure measurements are incorporated . In addition to all the interesting hemodynamic parameters a great deal of analysis on hematology, biochemistry and metabolic function has been done . The longest survival time in animals is over 200 days . Complications and problems are mostly due to the material, in which small lesions, cracks or slight flaws in fabrication or biodegradation are the starting point for thrombosis and later on calcification . The number of patients who should be given temporary cardiac assistance or total replacement is discussed. Drugs Exp Clin Res, 1985, 11(9), 633 - 40 Recent advances in the use of microspheres for targeted therapy; Davis SS et al.; In recent years the concept of using small colloidal particles for the selective delivery of drugs has been explored experimentally using a variety of different physical systems (for example, phospholipid vesicles (liposomes), triglyceride emulsions, albumin microspheres) and routes of administration . In such studies the aim has been to target a potent pharmacological agent on an organ or tissue site, thereby reducing adverse reactions and side-effects, or to provide a means of controlled release . The design of appropriate delivery systems must take into account the nature of the target and physiological barriers to targeting as well as factors such as drug loading and drug release, stability of the carrier system and its biocompatibility and biodegradation . Targeting with microspheres can be divided into passive methods that rely upon physiological and physicochemical determinants such as entrapment in capillary beds (lungs - particle size) or uptake by phagocytic cells (liver-surface characteristics), an active method whereby the particle is directed to a specific site through the use of surface coatings (surfactants, glycolipids, monoclonal antibodies) or a material sensitive to an external influence . Candidate systems presently under study are described . These include lipid emulsions for intravenous administration and microspheres for intra-articular delivery. Trans Ophthalmol Soc U K, 1985, 104 ( Pt 5), 517 - 21 Scanning electron microscope study on the biodegradation of IOL and suturing materials; Yamanaka A et al.; The biodegradation of the IOLs (27 cases: mainly prepupillary lens with pupillary fixation, irido-capsular and angle supported lens and a J loop lens for posterior chamber lens) and suturing materials of four cases have been studied by Scanning Electron Microscope (SEM) . The longest duration in the eye was 7.5 years and the shortest 0.3 year . The materials used for optics were PMMA with the exception of one case of glass . The materials for haptics were Nylon 6, Isot.PP, PMMA, PVDF, Polyimid and Pt-Ir . The suturing materials were Nylon 6 and Isot.PP . Nylon 6 degraded in the eye and Isot.PP degraded in the corneal tissue . But no biodegradation was observed in Isot.PP, PMMA, PVDF and Pt-Ir in the eye . In our investigations, biodegradation has some relationship to age (over 50 years old), duration (within 7.5 years) and inflammation of the eye, but ultimately biodegradation will depend on the individual situation . Degradation occurs most easily in the curved portion of Nylon 6. Mol Gen Genet, 1985, 201(2), 308 - 14 Molecular cloning and expression of the biodegradative threonine dehydratase gene (tdc) of Escherichia coli K12; Goss TJ et al.; The biodegradative threonine dehydratase gene (tdc) of Escherichia coli was cloned by isolating a dehydratase negative mutant after Tn5 mutagenesis, cloning the tdc::Tn5 DNA into pBR322 and then replacing the Tn5 element on the plasmid in vivo . Subcloning and nucleotide sequence data revealed two distinct procaryotic promoter-like elements each containing a potential CAP-binding site and AT-rich regions, and a Shine-Dalgarno sequence . One of these putative promoters, P2, was located immediately upstream from the tdc coding region, and a second, P1, was approximately 1 kilobase upstream from P2 . Deletion of the potential CAP-binding site from P1 prevented tdc gene expression . However, removal of P2 and a large segment of the upstream DNA had no discernible effect on dehydratase synthesis . A 936-base pair open reading frame was found between P1 and the tdc coding region, which produced a polypeptide of about 32 kilodaltons . The data suggest that P1, and not P2, is necessary for tdc gene expression, and that the DNA sequences coding for the 32 KD polypeptide and threonine dehydratase are part of a single transcriptional unit. J Biochem (Tokyo), 1985 Jan, 97(1), 387 - 90 Induction of spermidine/spermine N1-acetyltransferase by parathyroid hormone in rabbit costal chondrocytes in culture; Matsui-Yuasa I et al.; Parathyroid hormone (PTH) increased the activity of spermidine/spermine N1-acetyltransferase, a rate-limiting enzyme of polyamine biodegradation, in rabbit costal chondrocytes in culture . The enzyme activity increased in a dose-dependent manner after addition of PTH to the culture, reaching a maximum at 8 h . The increase in the enzyme activity was abolished by cycloheximide or actinomycin D . Dibutyryl cyclic AMP also induced the acetyltransferase to some extent . These results suggest that the induction of spermidine/spermine N1-acetyltransferase by PTH may play some significant role in the expression of the differentiated phenotype of chondrocytes. J Pharm Pharmacol, 1985 Jan, 37(1), 1 - 12 The fate of pharmaceutical chemicals in the aquatic environment; Richardson ML et al.; Increased demands for potable water, especially where supplies are drawn from lowland rivers has necessitated a greater degree of water re-use . As water undertakings have a duty to maintain the wholesome quality of potable water supplies, increasing concern is being expressed over the presence of organic micro-contaminants (contaminants found at microgram litre-1 concentrations) . This study outlines some of the problems encountered in assessing the risk from pharmaceutical chemicals which might enter the water cycle from domestic and industrial sources . Analytical chemistry was of value for only a few of the 200 compounds studied . However, much useful information was derived from the human metabolic routes of the drugs and is collated in Appendix I . Biodegradation studies and other ecotoxicity/environmental toxicology data may be required to a greater extent in the future . Particular consideration is given to vulnerable sections of the population. Ann N Y Acad Sci, 1985, 446, 67 - 75 In vitro and in vivo studies of drug-releasing poly(amino acids); Anderson JM; Preliminary efforts directed toward the synthesis and characterization of steroid-polyamino acid conjugates indicate that the preparation of these systems is feasible . Studies have indicated that the steroids may be released from the macromolecule resulting in long-term controlled release systems . Table 4 lists several of the variables that are important in controlling biocompatibility, biodegradation, and drug release characteristics . The biocompatibility, biodegradation, and drug release characteristics are all important in the design and preparation of a drug-polyamino acid delivery system . The variables listed in Table 4 may interact and interrelate to varying degrees when considering each of these factors independently . Although perhaps preliminary, efforts to date indicate that steroids bound to polyglutamic acid or polyglutamic acid derivatives are biocompatible, capable of undergoing biodegradation, and can release drugs at appropriate rates for extended periods of time. FEBS Lett, 1984 Dec 10, 178(2), 297 - 300 Phorbol esters stimulate spermidine/spermine N1-acetyltransferase activity in mitogen-stimulated bovine lymphocytes; Matsui-Yuasa I et al.; Phorbol 12-myristate-13-acetate (PMA) is shown to induce spermidine/spermine N1-acetyltransferase, a rate-limiting enzyme of polyamine biodegradation, in bovine lymphocytes . When PMA and phytohemagglutinin (PHA) were added simultaneously, the enzyme activity was stimulated synergistically . The ability of phorbol esters to stimulate the enzyme activity was consistent with their tumor-promoting ability . Phorbol, which is not a tumor promotor, was incapable of stimulating the enzyme activity . Phorbol diacetate weakly stimulated the activity of the acetylase . Phorbol dibutyrate had a similar stimulatory effect to PMA . These results suggest that the spermidine/spermine N1-acetyltransferase may play an important role in changes in polyamine levels in phorbol ester-treated cells and that the increase in the enzyme activity may have some relationship to the control of cell growth and differentiation by phorbol esters. J Steroid Biochem, 1984 Dec, 21(6), 763 - 71 Estrogen response of MCF-7 cells grown on diverse substrates and in suspension culture: promotion of morphological heterogeneity, modulation of progestin receptor induction; cell-substrate interactions on collagen gels; Pourreau-Schneider N et al.; In this study we observed the incidence of hormone sensitivity in the response of MCF-7 cells to estrogen stimulation when the cells were cultured in different contact environments (hydrophilic plastic, bovine corneal extracellular matrix, type I collagen and in suspension culture) . The major purpose was to describe the influence of cell to cell and cell to substrate contacts on the morphological response to estrogen treatment . However, other parameters including growth and induction of progestin receptor were also explored, keeping in mind that the MCF-7 cell line, although representative of normal mammary epithelium in that it contains a similar hormone receptivity, was selected in vitro from a metastatic population in a pleural effusion . Although substrate conditions did not modify growth enhancement by estrogens, progestin receptor levels were significantly higher in three-dimensional spheroid cultures in which cell to cell contacts were optimal due to elimination of basal contact . A careful morphological survey of large surfaces lead to an objective opinion of the overall effect of the hormone treatment on the non-cloned cell line in which a marked heterogeneity in the response of individual cells was observed . In terms of morphofunctional differentiation, the edification of acini with dense microvillus coating was best in suspension culture . When sections were made perpendicular to the plane of cultures on collagen gel rafts two other phenomena were noted: decrease in intercellular junctions, resulting in reduced cell to cell cohesion, and accumulation biodegradation products in the collagen lattice . This suggested a hormone-mediated interaction between the metastatic cells and the fibrillar substrate, collagen I, one of the major constituents of tissue stroma . This estrogen response might be related to the metastatic phenotype and must be distinct from their hormone sensitivity in terms of growth and differentiation since hormone receptivity is generally considered to be a favorable prognosis for breast cancer. Laryngoscope, 1984 Nov, 94(11 Pt 1), 1443 - 6 Reconstruction of hearing when malleus is absent: TORP vs . homograft TMMI; Lesinski SG; To study the most appropriate ossicular reconstruction of patients with an absent malleus, a comparison was made utilizing a homograft tympanic membrane with attached malleus and shaped incus (TMMI) columella and the alternative use of underlay fascia tympanoplasty with a cartilage covered TORP . Forty-six patients were reconstructed with a homograft TMMI and 38 with cartilage covered TORP and underlay fascia technique; 4.5 years postoperatively, 84% of those patients reconstructed with a homograft TMMI maintained an average A/B gap of 25 dB or better . Though 1 year postoperatively the TORP hearing results were satisfactory, only 18% of the TORP patients maintained a hearing level within 25 dB A/B gap at 4 years postoperatively . Primary causes of failure of the TORP were instability with migration off the stapes footplate, protrusion or extrusion through the TM and finally, long-term softening and bending secondary to biodegradation of the Plastipore . The discouraging long-term hearing results found in the TORP patients in this study confirm similar findings reported in 1982 by Smyth in a 5 year follow-up on 116 TORP patients. Ecotoxicol Environ Saf, 1984 Oct, 8(5), 471 - 81 Fate and biological effects of methyl parathion in outdoor ponds and laboratory aquaria . I . Fate; Crossland NO et al.; Three outdoor ponds were treated with methyl parathion (MEP) applied beneath the water surface at a concentration of 100 micrograms liter-1 . Laboratory aquaria containing either tap water, pond water, tap water plus plants, tap water plus sediment, or tap water plus sediment and plants were similarly treated . Samples of water, sediment, and fish were analyzed for residues of MEP . The rate of loss from water and concentrations found in sediment were compared with predictions based on a calculated rate of biodegradation and a sediment:water partition coefficient . The rate of loss of MEP from pond water isolated in an aquarium was similar to the predicted rate . However, the rate of loss from outdoor ponds, or from aquaria containing plants and sediment, was greater than predicted . MEP was not detected in sediment even though predicted concentrations far exceeded the limit of detection . These results are discussed and it is suggested that the rate of biodegradation in shallow bodies of water may be determined predominantly by bacteria attached to sediments and plants, rather than by planktonic bacteria . Bioaccumulation in fish was predicted from empirical equations based on the octanol:water partition coefficient . Observed values were in good agreement with predictions. Ecotoxicol Environ Saf, 1984 Oct, 8(5), 451 - 70 Biodegradation of 4-nitrophenol in standardized aquatic degradation tests; Nyholm N et al.; During the years 1978-1981 both the European Economic Community (the EEC) and the Organization for Economic Cooperation and Development (the OECD) organized various interlaboratory comparison programs on standardized screening methods to study the biodegradability of chemicals in water . While the ring test results were generally rather heterogenous, one of the compounds studied, 4-nitrophenol, turned out to be particularly problematic as the compound was found either easily biodegradable or not biodegradable by various laboratories in various tests . This paper describes some more detailed studies on 4-nitrophenol degradation in two different tests, the modified OECD screening test (MOST test) and the Zahn-Wellens test, respectively . The test variables investigated include inoculum characteristics and pretreatment, test duration, and 4-nitrophenol concentration . The results are discussed in relation to toxicity and degradation pathways of 4-nitrophenol . It is concluded that in order to improve the comparability of results from standardized aquatic biodegradation tests, test strategies should allow the option of performing a test with a preadapted inoculum in the event of negative test results with freshly collected inocula . Increasing the inoculated concentration of microorganisms in some tests may also contribute to the attainment of more consistent test results. Int J Cardiol, 1984 Oct, 6(4), 423 - 9 Pacemaker leads; Harthorne JW; Present day pacemaker leads are far superior in every respect to those of the past . Modification of fixation characteristics has reduced displacement rates to 1% or less in most centers . Fracture of multifilar leads is a rarity . Biodegradation of polyurethane insulation appears to be an isolated problem specific to individual lead models and may be related to physical stresses incurred during manufacture or lead insertion . Recent evidence has incriminated an interaction of polyurethane with silver which arises from the drawn braised strand conductor substrate of those leads in which this problem has been noted . This may explain why the problem has been restricted to specific lead models of one manufacturer to date . Lack of uniformity of lead terminal size between manufacturers and even within the same manufacturer's product line continues to baffle this observer . Although past problems of lead displacement have been markedly reduced, the difficulty of removing chronic leads which have become septic appears to have worsened . Modification of existing leads to ensure that the interface between electrode tip and proximal shaft is unidiametric is essential. Ecotoxicol Environ Saf, 1984 Oct, 8(5), 410 - 22 Biodegradability test results related to quality and quantity of the inoculum; Blok J et al.; For a series of different biodegradation test methods the biodegradation curves are simulated by computer . Simulations are performed on the basis of Monod growth kinetics corrected for cell decay . The possibility of discriminating between growth rates is related to variability of the inoculum quality and quantity . It is concluded that the variability of the inoculum masks all other information . The Repetitive Die Away test, however, offers a good opportunity to obtain information on growth rates that is highly relevant to environmental assessment . The conclusions derived from the computer-simulated curves are confirmed by experimental data. J Microencapsul, 1984 Oct-Dec, 1(4), 317 - 27 Biodegradable cross-linked albumin microcapsules for embolization; Benita S et al.; The interfacial polymerization process used in the present study produced individual cross-linked albumin microcapsules, the particle size of which depended on the emulsification stirring rate . The variation in cross-linking agent concentration altered the microcapsule wall properties . As shown by SEM observations, microcapsules prepared with low acyl chloride concentrations presented rippled surfaces, while the surfaces of the microcapsules prepared with high acyl chloride concentrations were smooth . It was then suggested that the membranes of the weakly cross-linked microcapsules consisted of cross-linked and denatured albumin . Embolization experiments in the dog kidney showed that the weakly cross-linked microcapsules were biodegradable within 7 days, whereas the highly cross-linked microcapsules were degraded over more than 14 days and led to prolonged ischaemia . The results of the histological experiments carried out on a further eight dogs supported the previous findings yielded by the angiographical experiments . Moreover, they indicated that no foreign body reaction occurred . The lack of this inflammatory granuloma should be attributed to the rapid biodegradation of the microcapsules which produced reversible ischaemic lesions. Appl Environ Microbiol, 1984 Sep, 48(3), 491 - 6 Mechanisms and pathways of aniline elimination from aquatic environments; Lyons CD et al.; The fate of aniline, a representative of arylamine pollutants derived from the manufacture of dyes, coal liquefaction, and pesticide degradation, was comprehensively evaluated by use of unpolluted and polluted pond water as model environments . Evaporation plus autoxidation proved to be minor elimination mechanisms, removing ca . 1% of the added aniline per day . Instantaneous binding to humic components of a 0.1% sewage sludge inoculum removed 4% . Biodegradation of aniline in pond water was accelerated by the sewage sludge inoculum . A substantial portion of the degraded aniline carbon was mineralized to CO2 within a 1-week period, and microbial biomass was formed as a result of aniline utilization . Biodegradation was clearly the most significant removal mechanism of polluting aniline from pond water . A gas chromatographic-mass spectrometric analysis of biodegradation intermediates revealed that the major pathway of aniline biodegradation in pond water involved oxidative deamination to catechol, which was further metabolized through cis,cis-muconic, beta-ketoadipic, levulinic, and succinic acid intermediates to CO2 . Minor biodegradation pathways involved reversible acylation to acetanilide and formanilide, whereas N-oxidation resulted in small amounts of oligomeric condensation products. Appl Environ Microbiol, 1984 Aug, 48(2), 451 - 3 2-Chloro-4-amino-1,3,5-triazine-6(5H)-one: a new intermediate in the biodegradation of chlorinated s-triazines; Grossenbacher H et al.; Pseudomonas sp . strain A grew with 2-chloro-1,3,5-triazine-4,6-diamine as the sole and growth-limiting source of nitrogen . The substrate was utilized quantitatively and concomitantly with growth and with excretion of a product which was identified as 2-chloro-4-amino-1,3,5-triazine-6(5H)-one . The reaction yielded 1 mol of organic product and 1 mol of NH4+ per mol of substrate. Br J Ind Med, 1984 Aug, 41(3), 389 - 95 In vitro biodegradation of chrysotile fibres by alveolar macrophages and mesothelial cells in culture: comparison with a pH effect; Jaurand MC et al.; The modification of the chemistry of asbestos chrysotile fibres (Mg3(Si2O5)(OH)4) after their ingestion by cultured cells has been studied . Two types of cells involved in asbestos related pulmonary disease were used, rabbit alveolar macrophages (AM), recovered by bronchoalveolar lavage, and pleural mesothelial cells (PMC) obtained from the rat parietal pleura . Chemical characterisation of intracellular fibres was performed on unstained ultrathin sections by electron probe microanalysis . The results showed a progressive leaching of Mg, characterised by a time dependent decrease of Mg/Si . AM were more efficient than PMC at leaching intracellular chrysotile fibres since it took longer to obtain the same proportion of leached fibres with PMC than with AM . As in vitro Mg-leaching can be obtained by acid treatment, chrysotile fibres were incubated, either untreated or pretreated with cell membranes, at pH 4 or 7 for various times . The data show that the kinetic of leaching by AM was comparable with leaching at pH 4 . The leaching by PMC was of the same order as leaching at pH 7 . When membranes were adsorbed on to the fibres, a delayed leaching was observed . The results indicate that the solubilisation of chrysotile by AM could be an intraphagolysosomal event due to a pH effect . With PMC, however, it is not possible to draw this conclusion since nothing is known about the intracellular pH. Clin Orthop, 1984 Jul-Aug, (187), 281 - 8 Long-term study of large ceramic implants (porous hydroxyapatite) in dog femora; Hoogendoorn HA et al.; Blocks of porous ceramic hydroxyapatite (dimensions, 2.5 X 1.25 X 0.5 cm; sintering temperature, 1300 degrees; macroporosity, 56%; average pore size 0.18 mm2) were implanted into surgically created defects in dog femora . The implants were retrieved up to 3.5 years after implantation . The implants were 3.5 years after implantation . The implants were firmly attached to the bone . Histologic evaluation suggests that optimal contact between bone and implant should be provided to accelerate bone ingrowth . Bone growth in the pores reached a maximum level after 35 weeks, at which time about one-third of the pore space was filled with bone . When measuring the relative surface areas of bone and ceramic on histologic slides, no change in ceramic mass could be detected, indicating that hydroxyapatite ceramics are not affected by biodegradation processes . The implants effectively provided a scaffold for bone growth bridging a larger bone defect. Mikrobiologiia, 1984 Jul-Aug, 53(4), 639 - 44 {Comparative study of the plasmids controlling naphthalene biodegradation by a Pseudomonas culture}; Kochetkov VV et al.; The object of this work was to study 25 Pseudomonas strains growing in a medium with naphthalene as a sole carbon source . Naphthalene catabolism was controlled by conjugative plasmids in 14 strains . The molecular mass of the plasmids was rather big, from 60 to 130 MD . The plasmids were classified in terms of their incompatibility group were assigned to the P-7 and P-9 groups five to each group . The incompatibility group could not be determined in four plasmids . The character of naphthalene catabolism controlled by the plasmids implies that only two of the plasmids control naphthalene oxidation via the "ortho" pathway of catechol cleavage which is an intermediate product in the oxidation of naphthalene . Just as most of the so far known plasmids controlling naphthalene biodegradation, seven of the plasmids studied in this work controlled naphthalene oxidation via the "meta" pathway of catechol cleavage. Ecotoxicol Environ Saf, 1984 Jun, 8(3), 275 - 9 Comparison of methods for the biodegradability evaluation of soluble and insoluble organochemicals; Ruffo C et al.; Pyridine and nitrilotriacetic acid sodium salt as models of soluble compounds and linear dodecylbenzene, branched dodecylbenzene, and stearic acid as models of insoluble compounds were compared for their biodegradability in three tests: the ODCE modified test and the Sturm and enrichment culture tests . The degradation of soluble compounds was measured as dissolved organic carbon removal and CO2 evolution, while for the insoluble compounds, which were tested only in the Sturm test, CO2 evolution was determined . The individual tests were characterized by comparing their results with those obtained in the others . Comparable biodegradation values higher than 90% were obtained for the soluble compounds . The Sturm test proved to be very suitable for the evaluation of biodegradability of either soluble or insoluble compounds. Can J Microbiol, 1984 Jun, 30(6), 786 - 92 Impact of an oil field effluent on microbial activities in a Wyoming river; Heitkamp MA et al.; The survival, functions, and physiological diversity of autochthonous sediment microbiota were examined in situ at five stations along the Little Popo Agie River, WY; one station above, one at, and three below a discharge point for oil wastewater from Union Oil Company's Dallas Field . Below the oil wastewater discharge point there were increases in electron-transport activity, carbon dioxide production, and microbial populations of heterotrophs, ammonifiers, hexadecane degraders, starch hydrolyzers, protein hydrolyzers, and sulfate reducers . At a station 1420 m below the discharge point, however, overall sediment microbial activities and all of the physiological groups of bacteria, except hexadecane-degrading microbiota, were at levels comparable with those at the control station above the discharge point . Similarly, mineralization of glucose, amino acids, hexanoic acid, and hexadecane was elevated at stations directly below the discharge point, but appeared to subside rapidly . Xenobiotic biodegradation potential of the sediments varied with the chemical and the sample location and was not directly related to oil residue levels in the sediment . Microorganisms thus appeared to maintain physiological diversity and increased in numbers and activity in a riverine environment that contained petroleum hydrocarbon concentrations known to be deleterious to freshwater fish and macrobenthic communities. J Bacteriol, 1984 Jun, 158(3), 826 - 31 Escherichia coli K-12 mutation that inactivates biodegradative threonine dehydratase by transposon Tn5 insertion; Goss TJ et al.; From a collection of kanamycin-resistant mutants of Escherichia coli K-12 isolated by transposon Tn5 mutagenesis, we have identified a mutant that lacks functional biodegradative threonine dehydratase (EC 4.2.1.16) by direct enzyme assay and by the loss of cross-reacting material with affinity-purified antibodies against the purified enzyme . Aerobic and anaerobic growth of this strain on various carbon sources failed to reveal a phenotype . Evidence for the insertional inactivation of threonine dehydratase by Tn5 was obtained by cloning the DNA segments flanking the Tn5 insertion site into pBR322 and hybridizing the cloned DNA to a synthetic oligodeoxynucleotide probe complementary to the DNA segment coding for a unique hexapeptide at the amino terminus end of the enzyme; the region of homology to the synthetic cDNA sequence appears to be located within about 500 nucleotides from one end of Tn5 . Genetic analysis with the transposon element that caused insertional inactivation located the tdc gene at min 67 on the E . coli chromosome. Appl Environ Microbiol, 1984 Apr, 47(4), 850 - 7 General method for determining anaerobic biodegradation potential; Shelton DR et al.; A simple, generalized method was refined and validated to test whether an organic chemical was susceptible to anaerobic degradation to CH4 + CO2 . The method used digested sewage sludge diluted to 10% and incubated anaerobically in 160-ml serum bottles with 50 micrograms of C per ml of test chemical . Biodegradation was determined by the net increase in gas pressure in bottles with test chemicals over the pressure in nonamended sludge bottles . Gas production was measured by gas chromatography and by a pressure transducer . The latter method is recommended because of its speed, accuracy, and low cost . Sewage sludge from municipal digesters with 15- to 30-day retention times was found to be suitable . The sludge could be stored anaerobically at 4 degrees C for up to 4 weeks with satisfactory test results . p-Cresol, phthalic acid, and ethanol are suggested as reference chemicals to confirm sludge activity and method reliability . A revised anaerobic salts medium was developed which minimizes problems of a biological gas production (CO2), avoids precipitation, and meets the requirements of the anaerobic microbiota . When greater than 75% of the theoretical gas production was observed, the chemical was judged to be degradable, and when 30 to 75% of the expected gas was produced, it was termed partially degradable . This method has been tested on more than 100 chemicals of various physical properties and found to reproducibly determine anaerobic biodegradation potential . Of the chemicals tested, 46 were found to be anaerobically degraded . Sludges from nine different municipal treatment plants were surveyed for their ability to degrade nine chemicals which differed in susceptibility to degradation.(ABSTRACT TRUNCATED AT 250 WORDS) Ecotoxicol Environ Saf, 1984 Feb, 8(1), 34 - 54 Fate and effects of 3,4-dichloroaniline (DCA) in marine plankton communities in experimental enclosures; Kuiper J et al.; The fate and effects of single doses of 3,4-dichloroaniline (DCA) on North Sea coastal plankton communities enclosed by large plastic bags (contents 1.5 m3) were studied in two experiments lasting 5 and 6 weeks, respectively . The biodegradation of DCA was also studied in laboratory experiments, which were carried out simultaneously, using water from the enclosed model ecosystems . DCA was not degraded in the laboratory tests and probably also not degraded in the enclosed plankton communities, although concentrations in the water decreased during the experiments . This decrease appeared to be partly caused by diffusion of DCA through the walls of the enclosures . After the addition of single doses of 2, 10, and 25 microgram liter-1 DCA no effects on the enclosed plankton community could be detected . The addition of 0.1 mg liter-1 DCA had a clear influence on the species composition and the biomass development of the phytoplankton, changed the relative species composition of the zooplankton, and resulted in lower numbers of bacteria . In addition to these effects 1 mg liter-1 DCA limited the phytoplankton growth and resulted in mortality and inhibition of growth of the copepods. Ecotoxicol Environ Saf, 1984 Feb, 8(1), 15 - 33 Fate and effects of 4-chlorophenol and 2,4-dichlorophenol in marine plankton communities in experimental enclosures; Kuiper J et al.; The fate and effects of 4-chlorophenol (4CP) and 2,4-dichlorophenol (DCP) added to North Sea coastal plankton communities enclosed by large plastic bags were studied in three experiments of 4 to 6 weeks duration . The biodegradation of the compounds was studied in laboratory experiments using water from the enclosed ecosystems . 4CP and DCP, added at initial concentrations of 0.1-1.0 mg X liter-1, disappeared from the water in the enclosures in 5 to 23 days, 4CP generally being the less persistent . Degradation rates were generally comparable to those found in laboratory tests with the same water . 4CP was removed by biodegradation, and DCP was probably removed by a combination of biodegradation, photodegradation, and/or chemical degradation . Results indicated that biodegradation rates could be limited by lack of inorganic nutrients, leading to much lower degradation rates than would be expected from routine laboratory tests . Faster degradation after repeated addition of 4CP showed adaption of the bacterial community . Addition of 0.3 mg liter-1 4CP or DCP inhibited the phytoplankton growth rate slightly . The 1 mg liter-1 4CP or DCP inhibited the phytoplankton, changed the species composition, and also influenced the zooplankton . In two of the three experiments 1 mg liter-1 DCP resulted in a temporary lowering of bacterial numbers following the addition . In one experiment inhibitory effects were found after 4CP and DCP had disappeared from the water, pointing to the formation of a more toxic intermediate during the degradation of these compounds . The laboratory tests also indicated the formation of relatively stable intermediates . The concentrations causing the effects in the different bag experiments were quite similar . This indicates that, although the development of the plankton communities during the different experiments was different, the concentrations resulting in ecological effects are quite reproducible. Anal Biochem, 1984 Feb, 136(2), 314 - 20 Determination of trace levels of fatty acid metal salts by high-performance liquid chromatography with fluorescence prelabeling; Hayashi K et al.; A simple method is described for picomole determinations of fatty acid metal salts . Fatty acid salts are directly labeled with 4-bromomethyl-7-methoxycoumarin in the presence of excess ethylenediaminetetraacetic acid tripotassium salt without any solvent extractions . The fluorescence derivatives of fatty acids are separated by reverse-phase high-performance liquid chromatography followed by fluorometric detection . The response of each fatty acid (C8-C18) calcium salt is linear from 1 to 50 micrograms/ml of samples . The detection limit is about 7 pmol . Good recoveries are obtained for the calcium salts of myrystic acid and soap (C8-C18, C18:1,2) . The new method is successfully applied to the study on biodegradation of fatty acids in river water. Appl Environ Microbiol, 1984 Feb, 47(2), 272 - 7 Anaerobic biodegradation of chlorophenols in fresh and acclimated sludge; Boyd SA et al.; We investigated the anaerobic biodegradation of mono- and dichlorophenol isomers by fresh (unacclimated) sludge and by sludge acclimated to either 2-chlorophenol, 3-chlorophenol, or 4-chlorophenol . Biodegradation was evaluated by monitoring substrate disappearance and, in selected cases, production of 14CH4 from labeled substrates . In unacclimated sludge, each of the monochlorophenol isomers was degraded . The relative rates of disappearance were in this order: ortho greater than meta greater than para . For the dichlorophenols in unacclimated sludge, reductive dechlorination of the Cl group ortho to phenolic OH was observed, and the monochlorophenol compounds released were subsequently degraded . 3,4-Dichlorophenol and 3,5-dichlorophenol were persistent . Sludge acclimated to 2-chlorophenol cross-acclimated to 4-chlorophenol but did not utilize 3-chlorophenol . This sludge also degraded 2,4-dichlorophenol . Sludge acclimated to 3-chlorophenol cross-acclimated to 4-chlorophenol but not to 2-chlorophenol . This sludge degraded 3,4- and 3,5-dichlorophenol but not 2,3- or 2,5-dichlorophenol . The specific cross-acclimation patterns observed for monochlorophenol degradation demonstrated the existence of two unique microbial activities that were in turn different from fresh sludge . The sludge acclimated to 4-chlorophenol could degrade all three monochlorophenol isomers and 2,4- and 3,4-dichlorophenol . The active microbial population in this sludge appeared to be a mixture of populations present in the 2-chlorphenol- and 3-chlorophenol-acclimated sludges, both of which could utilize 4-chlorophenol . Experiments with 14C-radiolabeled p-chlorophenol, o-chlorophenol, and 2,4-dichlorophenol demonstrated that these compounds were converted to 14CH4 and 14CO2. Biochem Biophys Res Commun, 1984 Jan 30, 118(2), 437 - 43 Fatty acyl-coenzyme A oxidase activity and H2O2 production in Phanerochaete chrysosporium mycelia; Greene RV et al.; Mycelia of the lignin-degrading fungus Phanerochaete chrysosporium consume O2 and produce extracellular H2O2 when incubated with fatty acyl-CoA substrates, even in the presence of mitochondrial respiratory chain inhibitors such as antimycin A and cyanide . These results suggest the possibility that peroxisomal fatty acyl-CoA oxidase activity in P . chrysosporium mycelia may be an important metabolic source for the extracellular H2O2 believed to be involved in lignin biodegradation. Basic Life Sci, 1984, 28, 3 - 21 Microbial biodegradation of 2,4,5-trichlorophenoxyacetic acid and chlorophenols; Karns JS et al.; We have succeeded in isolating a pure culture of Pseudomonas cepacia, AC1100, from a chemostat enrichment culture experiment that is capable of growing on 2,4,5-trichlorophenoxyacetic acid as its sole source of carbon and energy . AC1100 is not only capable of degrading 2,4,5-T but is also able to completely or partially dehalogenate a wide variety of halophenols . The regulation of the dehalogenating ability of AC1100 has been investigated which demonstrates that the enzyme(s) which allow the conversion of 2,4,5-T to 2,4,5-TCP are constitutive, while the enzymes that allow the degradation of 2,4,5-TCP are inducible by 2,4,5-TCP (or some metabolite of 2,4,5-TCP) but not by 2,4,5-T or other halophenols which can serve as substrates . Moreover, the 2,4,5-TCP degradative pathway is repressed by the presence of an abundant alternative carbon source . The detailed pathway of 2,4,5-T degradation by AC1100 is currently under study . Although field tests have yet to be conducted, laboratory experiments have demonstrated rapid and complete degradation of 2,4,5-T from contaminated soil . Soil previously contaminated with as much as 5,000 micrograms of 2,4,5-T/g of soil could be detoxified by AC1100 treatment, allowing the growth of plants sensitive to less than 10 micrograms 2,4,5-T/g of soil . Moreover soil contaminated with as much as 20,000 micrograms of 2,4,5-T/g of soil showed greater than 90% degradation after six weekly AC1100 treatments . After 2,4,5-T has been substantially degraded in contaminated soil the titer of AC1100 rapidly falls to nearly undetectable levels, which indicates that no serious ecological disturbance is likely to result from the application of AC1100 . It appears possible that the treatment of contaminated areas with appropriate microorganisms may allow essentially a total restoration of the original soil condition. Basic Life Sci, 1984, 28, 137 - 49 Land disposal and spill site environments; Middleton AC; Land is a receptor of many chemicals through both intentional and unintentional depositions . Mitigation methods for control of the chemicals resulting from unintentional depositions such as unsuccessful landfills, spills, and leaks include excavation and disposal, entombment in place, and in some situations, in situ biodegradation . If genetically engineered bacteria could expand the number of situations where in situ degradation is applicable, then more economically efficient control methods resulting in the destruction of chemicals would be available . This paper outlines the various processes affecting the fate of organic chemicals in the soil environment, summarizes the environmental conditions encountered by organisms, and reviews two case histories of biodegradation of chemicals within the soil environment . Environmental conditions encountered by organisms are distinctly different in the two major soil zones: the unsaturated zone and the saturated zone . Chemicals may be present within the soil environment including the vapor phase, the adsorbed phase, and the soluble phase . These differences affect the fates of each chemical and result in greatly different rates of biodegradation of chemicals by naturally occurring microorganisms . Case histories discussed are that of a spray irrigation field treating wastewater from a creosote wood treating process, and that of an in situ biodegradation program for clean up of surface soils contaminated with pentachlorophenol . Recommendations for bacterial characteristics that could be engineered to greatly expand the applicability of in situ biodegradation are made. Ann Surg, 1984 Jan, 199(1), 61 - 8 Biodegradation and aneurysm formation in umbilical vein grafts . Observations and a realistic strategy; Dardik H et al.; In a series of 756 glutaraldehyde-stabilized umbilical vein grafts implanted over a 7 1/2-year period, aneurysms were identified in seven cases . The earliest aneurysm was seen at 31 months after implantation and the remainder between 43 and 79 months after surgery . Corrective surgery was performed in five cases and succeeded in four . Although definite mechanisms have not been identified, mechanical fatigue, reversal of aldehyde crosslinks, and immunologic factors may be operative . The pathologic changes include: (1) actual dilation of both graft and mesh with or without intraluminal thrombus and, (2) maintenance of graft diameter with erosion of the umbilical vein and polyester mesh rupture leading to perigraft hematoma and false aneurysm formation . Microscopic examination and infrared spectral analysis confirmed the presence of host-contributed lipid in some specimens . Although this is a low incidence of aneurysm formation, umbilical vein grafts should be selected primarily for patients with limited life expectancy or for whom alternative materials with comparable or superior patency rates are not available or acceptable . Periodic angiography, particularly after 3 or 4 years, is recommended as a routine part of follow-up examinations . Improved graft materials and control of host environmental factors are potential means to reduce the noted degradation. Polim Med, 1984, 14(1-4), 37 - 54 {Polymer fibers in surgery . II}; Privalova LG et al.; Polyamide fibres were one of the first synthetic fibres to be widely used in surgery . They are durable, elastic, abrasion- and deformation-resistant, and withstand the biological action of chemical agents . Moreover, they have small susceptability to moisture sorption and large values of percentage elongation . In surgery polycaproamide fibres (PKA) are usually used--capron, nylon-6, perlon, stylon, sylon and others, they can be easily and reliably sterilized, do not facilitate infection spreading in the thread, and are relatively well resorbed . The fibres were used as surgical threads and nets, vascular prostheses, woven and knitted fabric in hernia treatment, diaphragm injuries, strengthening the diaphragm seam, an other reconstruction operations . In most cases the tissues adjoining the implant react moderately . It is suggested that porous materials should be used as implants, so that they overgrow with tissue, and gradually undergo biodestruction . Depending on the kind and structure of fibres, and specific tissue properties, the biodegradation period varies from 2-3 weeks to 2-3 years . According to the authors this depends on polymer breakdown by means of hydrolysis . In the paper conditions of fibre modifications are shown in order to improve their usability in therapy . Quantitative changes in biodestruction of various kinds of polycaproamide threads in the organism are described . It is stressed that polyundecanamide fibres (undecan, nylon-11) are less applicable in surgery than polyhexametyleno-2-amide ones (anid, nylon-6,6) . Through of some favourable properties, polyamide fibres have a very restricted application in surgery; their surface is rough, which makes surgical binding difficult, thin threads, last shortly in tissues, lose elasticity, get brittle and fragile . The period of their biodestruction is rather short . In conclusion it is stated that polyamide fibres are not suitable for durable prostheses. Arch Orthop Trauma Surg, 1984, 103(3), 145 - 51 Histological results with cement-free implanted hip joint sockets of polyethylene; Remagen W et al.; The histological appearance of the implant-bone boundary in eight preparations from seven deceased patients in whom a polyethylene acetabulum socket had been inserted without cement between 3 weeks and 3 years previously is described . In all cases, a good or excellent clinical result had been present up to death . All sockets were firmly anchored macroscopically in the bone of the acetabulum . Three zones were defined in accordance with the mechanical strain on the surface of the cup: (a) zone of compression; (b) zone of transition in which mainly shear forces act; and (c) zone of decompression, which corresponds to the region below the "equator." It was noticeable that a layer of connective tissue separated the implant from the bone over almost the entire surface . This layer was very thin in the region of the pressure transfer layer, and thicker in the decompression zone . At sites at which pressure and shear forces act a fibrocartilaginous tissue was found, and the "subchondral" bone was only occasionally in direct contact with the polyethylene surface . At some sites, but above all in the region of the compression zone, very tiny particles that were birefringent in polarized light were found . Either these derive from very fine grindings from the prosthesis surface or they are to be interpreted as a result of "biodegradation" of the polyethylene . This observation permits the conclusion that the biocompatibility of the implant can be improved further by coating the polyethylene surface. Basic Life Sci, 1984, 28, 117 - 35 Plasmid-mediated biodegradative fate of monohalogenated biphenyls in facultatively anaerobic sediments; Sayler GS et al.; The results of these studies have demonstrated that model PCB substrates can be mineralized by indigenous microbial population in contaminated sediments . This catabolic function can be rate limited at the microenvironmental level by physical-chemical processes such as physical partitioning and accumulation . At the biochemical level, this catabolic function is determined by the existence of plasmid borne genes that, under laboratory conditions, can be maintained and expressed in pure or mixed culture . Numerous limitations are encountered in establishing the significance of these biodegradative bacteria and the catabolic plasmids at the environmental level . Relatively little information is available concerning frequencies and stability of the bacteria or the plasmid encoded genes within the community . There is no information on the incompatibility grouping of the isolated plasmid relative to other plasmids maintained within the populations . Such factors will influence the development of gene screening techniques to monitor gene frequency distributions in the sediment community . Although mineralization of 4CBP was observed under moderately reducing conditions, it remains suspect that transient or trace levels of dissolved oxygen may have permitted conventional aerobic metabolism of the substrate . If this is true, demonstrating anaerobic metabolism of environmental contaminants will require strict and tedious cultivation under highly reduced conditions (approximately-300 mV) . Large deletions of cryptic DNA observed under laboratory conditions may affect bacterial survival and gene maintenance and transfer under environmental conditions . Little information exists on regulation of catabolic activity of selective pressures required to maintain the degradative genes under environmental conditions . Such limitation encountered in these studies are shared by virtually all attempts to utilize genetically manipulated bacteria or newly isolated strains and plasmids . Perhaps the fundamental question is whether the catabolic genes are maintained and expressed within the community rather than whether the host bacterium can survive in the environment. Appl Biochem Biotechnol, 1984, 10, 41 - 56 Enzyme-albumin polymers . New approaches to the use of enzymes in medicine; Poznansky MJ; The widespread use of enzymes as drugs or therapeutic agents has been limited by (a) enzyme availability, (b) biodegradation of administered enzyme, (c) immunogenecity of the enzyme as a foreign protein, and (d) accessibility of the enzyme to the appropriate site of action . It has become obvious that due to these limitations, the administration of free or native enzyme is not likely to be effective . Various mechanisms of protecting or packaging enzymes to offset some of these drawbacks have been described . We have been successful in producing conjugates of a number of different enzymes with a molar excess of homologous albumin . The resulting enzyme-albumin complex is resistant to proteolytic and heat inactivation and is apparently non-immunogenic . Using specific ligands crosslinked to the enzyme-albumin conjugate we have been able to target these conjugates to specific receptor sites and specific tissues . Ligands including cell surface-recognizing antibodies and hormones such as insulin have been used . These approaches offer new possibilities for the increased use of enzymes in medicine. J Microencapsul, 1984 Jan-Mar, 1(1), 21 - 5 Chemoembolization: principles and perspectives; Madoule P et al.; Chemoembolization is the injection of active-principle-bearing microparticles via selective catheterization . The authors discuss the advantages and the possibilities of this method in relation to selective catheterization and to the various time periods required for microparticle biodegradation and the kinetics of drug release . Particular attention is paid to intra-arterial chemoperfusion, chemoembolization and chemoinfusion with microparticles. Drug Metab Dispos, 1984 Jan-Feb, 12(1), 98 - 105 Effects of exposure concentrations on distribution of halothane metabolites in the body; Fiserova-Bergerova V et al.; The effect of exposure concentration on halothane metabolism was studied in rats exposed to subanesthetic concentrations of halothane in air . Concentrations of halothane, total nonvolatile fluorine, and volatile metabolites (CF3CH2Cl and CF2 = CHCl) were determined in liver, kidneys, muscles, and brains excised at the end of a 3-hr exposure . It was observed that concentrations of all halothane metabolites in tissues rose less than exposure concentrations, that nonvolatile fluorine was present in all tissues in approximately the same concentrations, and that concentrations of volatile metabolites in liver were much higher than in any other tissues . A simulation model was used to support the following conclusions . Metabolism of halothane by all metabolic pathways is flow limited at small exposure concentrations and is capacity limited at high exposure concentrations . Volatile metabolites formed in livers are efficiently removed from circulation by pulmonary clearance, but trifluoroacetic acid is accumulated in the body . Halothane is most susceptible to biodegradation to trifluoroacetic acid, but this pathway is saturated at very small exposure concentrations . Susceptibility to biodegradation of volatile metabolites is small, but the pathways are not saturated even at anesthetic concentrations . The contribution of each of the three metabolites to total metabolic clearance depends on exposure concentrations . Trifluoroacetic acid was the major metabolite during exposure to small halothane concentrations; formation of more toxic, volatile metabolites increased during exposure to high concentrations . Postmortem formation of metabolites was studied in order to prevent its interference with tissue analysis . The method for determination of volatile metabolites is described. Appl Environ Microbiol, 1983 Nov, 46(5), 1024 - 31 Biodegradation and photolysis of pentachlorophenol in artificial freshwater streams; Pignatello JJ et al.; The biodegradation, photolysis, and adsorption of pentachlorophenol (PCP) in outdoor, aquatic environments were examined with man-made channels built by the U.S . Environmental Protection Agency at a field station on the Mississippi River near Monticello, Minn . Four channels were used, each channel being approximately 520 m long and receiving river water that flowed through the channels for about 10 h before reentering the river . The channels were dosed continuously during the summer of 1982 with various concentrations of PCP (approximately 0, 48, 144, and 432 micrograms/liter) . We monitored the biotic and abiotic degradation of PCP in these channels for approximately 16 weeks . Photolysis of PCP was rapid at the water surface, but greatly attenuated with depth . Depending on sunlight conditions, photolysis accounted for a 5 to 28% decline in initial PCP concentration . Adsorption of PCP by sediment and uptake by biota accounted for less than 15% and probably less than 5% in unacclimated water . Microbial degradation of PCP became significant about 3 weeks after the initiation of dosing and eventually became the primary mechanism of PCP removal, accounting for a 26 to 46% (dose-dependent) decline in initial PCP . Most of the PCP-mineralizing microorganisms that developed in the channels were either attached to surfaces (e.g., rocks and macrophytes) or associated with surface sediments . Total bacterial numbers (direct microscopic counts) in the various channels were not affected significantly by PCP concentrations of micrograms per liter . Numerous strains of bacteria able to grow at the expense of PCP were isolated from the adapted channels . The experiments reported here will help predict the responses of flowing aquatic ecosystems to contamination by biocides such as pentachlorophenol. Fed Proc, 1983 Nov, 42(14), 3128 - 31 Leukocyte recognition and metabolism of leukotrienes; Goetzl EJ; The lipoxygenation of arachidonic acid in many different types of cells generates diverse mediators of hypersensitivity and inflammation . The leukotrienes represent one such family of mediators, which exert potent effects on smooth muscle, the microcirculation, and leukocytes . Leukocytes express distinct subsets of receptors for different leukotrienes . Transpeptidatic, peptidolytic, oxidative, and peroxidative pathways of leukocytes contribute substantially to the interconversion and biodegradation of leukotrienes . The 5-lipoxygenation of endogenous arachidonic acid appears to be a critical prerequisite for the activation of the function of leukocytes and some other cells . Natural and pharmacological inhibitors of 5-lipoxygenation in T lymphocytes noncytotoxically suppress the migration and transformation of the lymphocytes in response to antigens and mitogens . Lipoxygenase products of arachidonic acid thus fulfill important roles both as extracellular mediators and as functional intracellular constituents. Ital J Orthop Traumatol, 1983 Sep, 9(3), 377 - 86 Metallic debris arising from prosthetic abrasion: investigation of biodegradation of the materials and physiopathology of the bone; Portigliatti Barbos M et al.; The authors investigated the tissue around a failed knee prosthesis which had a metal-on-metal bearing made of chromium-cobalt-molybdenum alloy . Histological examination and the quantitative analysis of metallic particles found in the bone marrow (by fluorescent spectrometry and laser microsound) provided a detailed picture of the quantity, nature and distribution of the wear debris . The type and nature of the tissue response to the presence of the metal particles was determined by fluorescent microscopy and microradiography. Appl Environ Microbiol, 1983 Sep, 46(3), 661 - 5 Absence of microbial mineralization of lignin in anaerobic enrichment cultures; Odier E et al.; The existence of anaerobic biodegradation of lignin was examined in mixed microflora . Egyptian soil samples, in which rapid mineralization of organic matter takes place in the presence of an important anaerobic microflora, were used to obtain the anaerobic enrichment cultures for this study . Specifically, 14CO2 or {14C}lignin wood was used to investigate the release of labeled gaseous or soluble degradation products of lignin in microbial cultures . No conversion of 14C-labeled lignin to 14CO2 or 14CH4 was observed after 6 months of incubation at 30 degrees C in anaerobic conditions with or without NO3- . A small increase in soluble radioactivity was observed in certain cultures, but it could not be related to the release of catabolic products during the anaerobic biodegradation of lignin. Can J Microbiol, 1983 Sep, 29(9), 1087 - 91 Factors influencing the inhibition of aflatoxin production in corn by Aspergillus niger; Horn BW et al.; Aspergillus niger, a mold commonly associated with Aspergillus flavus in damaged corn, interferes with the production of aflatoxin when grown with A . flavus on autoclaved corn . The pH of corn-meal disks was adjusted using NaOH-HCl, citric acid-sodium citrate, or a water extract of A . niger fermented corn . Aflatoxin formation was completely inhibited below pH 2.8-3.0, irrespective of the system used for pH adjustment . When grown in association with A . flavus NRRL 6432 on autoclaved corn kernels, A . niger NRRL 6411 lowered substrate pH sufficiently to suppress aflatoxin production . The biodegradation of aflatoxin B1 or its conversion to aflatoxin B2a were eliminated as potential mechanisms by which A . niger reduces aflatoxin contamination . A water extract of corn kernels fermented with A . niger caused an additional inhibition of aflatoxin formation apart from the effects of pH. Proc Natl Acad Sci U S A, 1983 Sep, 80(17), 5181 - 4 Regulation of polyamine biosynthesis in Escherichia coli by basic proteins; Heller JS et al.; In Escherichia coli, the biosynthetic ornithine and arginine decarboxylases (EC 4.1.1.17 and 4.1.1.19, respectively) are responsible for the biosynthesis of polyamines from ornithine and arginine, respectively . When E . coli cells are grown in the presence of increasing amounts of polyamines, a progressive increase in the amount of antizyme 1 and antizyme 2 occurs . The amino acid compositions of antizymes 1 and 2 show them to be basic proteins; antizyme 1 has an amino acid composition similar to that of the E . coli histone-like protein HU and of the eukaryotic histone H2B; antizyme 2 is characterized by an unusually high arginine content . We find these proteins to be specific inhibitors of both the biosynthetic ornithine decarboxylase and the biosynthetic arginine decarboxylase . They do not inhibit the corresponding biodegradative ornithine and arginine decarboxylases, nor do they inhibit lysine decarboxylase or S-adenosylmethionine decarboxylase . These properties of the antizymes favor their function in the regulation of polyamine biosynthesis in E . coli . The ability of the purified antizymes to inhibit the ornithine and arginine decarboxylases is stabilized in acidic buffers and is lost upon prolonged exposure to solutions at neutral or basic pH. J Biomed Mater Res, 1983 Sep, 17(5), 769 - 84 Biodegradation behavior of various calcium phosphate materials in bone tissue; Klein CP et al.; In order to study the biodegradation behavior of calcium phosphate materials, cylinders of standard size were implanted in the tibiae of rabbits . Material parameters were stoichiometry (hydroxyapatite with a Ca/P ratio of 1.67 versus tricalcium phosphate with a Ca/P ratio of 1.50), crystallographic structure (apatite versus beta-whitlockite), microporosity, and macroporosity . The extent of biodegradation was evaluated by radiography, light and fluorescence microscopy, microradiography, and porosity measurements . All calcium phosphate materials were biocompatible in bone tissue . Hydroxyapatite ceramics had a higher osteogenic potential than beta-whitlockite materials . Depending on their porosities, sintered tricalciumphosphate (beta-whitlockite) materials were more or less biodegradable, in contrast to sintered hydroxyapatite materials, which showed no detectable resorption over a period of 9 months of implantation. Life Sci, 1983 Aug 29, 33(9), 835 - 40 Met-enkephalin binding to opiate receptors is not functionally coupled to biodegradation; Nagy A et al.; Using synaptosomal rat brain membranes, the degradation of Met-enkephalin in both free and receptor-bound form was measured, together with the dissociation of Met-enkephalin from the receptors . The results show that the degradation rate of initially receptor-bound Met-enkephalin is significantly smaller than either the rate of dissociation from the receptors or that of the degradation of free Met-enkephalin . These data suggest that intact Met-enkephalin dissociates from the receptors and then it becomes a target for the same membrane-associated peptidases that split free Met-enkephalin . This view is supported by the good fitness of the measured degradation of initially receptor-bound Met-enkephalin to the predicted degradation curve calculated from the dissociation rate of receptor-bound Met-enkephalin and the degradation rate of free Met-enkephalin. Biochem Biophys Res Commun, 1983 Aug 12, 114(3), 1077 - 83 An extracellular H2O2-requiring enzyme preparation involved in lignin biodegradation by the white rot basidiomycete Phanerochaete chrysosporium; Glenn JK et al.; An H2O2-requiring enzyme system was found in the extracellular medium of ligninolytic cultures of Phanerochaete chrysosporium . The enzyme system generated ethylene from 2-keto-4-thiomethyl butyric acid (KTBA), and oxidized a variety of lignin model compounds including the diarylpropane 1-(4'-ethoxy-3'-methoxyphenyl) 1,3-dihydroxy-2-(4"-methoxyphenyl)propane (I), a beta-ether dimer 1-(4'-ethoxy-3'-methoxyphenyl)glycerol-beta-guaiacyl ether (IV) and an olefin 1-(4'-ethoxy-3'-methoxyphenyl)1,2-propene (VI) . The products found were equivalent to the metabolic products previously isolated from intact ligninolytic cultures . In addition, the enzyme system partially degraded 14C-ring labeled lignin . The enzyme was not found in high nitrogen (N) cultures, nor in cultures of a ligninolytic mutant strain which is incapable of metabolizing lignin. J Bacteriol, 1983 Aug, 155(2), 586 - 92 Synthesis of biodegradative threonine dehydratase in Escherichia coli: role of amino acids, electron acceptors, and certain intermediary metabolites; Hobert EH et al.; The specific activity of inducible biodegradative threonine dehydratase (EC 4.2.1.16) in Escherichia coli K-12 increased significantly when the standard tryptone-yeast extract medium or a synthetic mixture of 18 L-amino acids was supplemented with 10 mM KNO3 or 50 mM fumarate and with 4 mM cyclic AMP . In absolute terms, almost four times as much enzyme was produced in the amino acid medium as in the tryptone-yeast extract medium . Enzyme induction in the amino acid medium was sensitive to catabolite repression by glucose, gluconate, glycerol, and pyruvate . An analysis of amino acid requirements for enzyme induction showed that a combination of only four amino acids, threonine, serine, valine, and isoleucine, produced high levels of threonine dehydratase provided that both fumarate and cyclic AMP were present . Immunochemical data revealed that the enzyme synthesized in the presence of these four amino acids was indistinguishable from that produced in the tryptone-yeast extract or the medium with 18 amino acids . We interpret these results to mean that not the amino acids themselves but some metabolites derived anaerobically in reactions involving an electron acceptor may function as putative regulatory molecule(s) in the anaerobic induction of this enzyme. Dev Biol, 1983 Jul, 98(1), 182 - 6 Metabolism of sulfogalactosyl glycerolipids in the myelinating mouse brain; Burkart T et al.; The in vivo metabolism of sulfogalactosyl glycerolipids (SGG) was studied in the cerebrum and cerebellum of developing mice after intraperitoneal injection of {35S}sulfate . After correction for the specific radioactivity changes of blood sulfate the quantitative rates of biosynthesis and biodegradation of this lipid could be determined . In addition, the net accumulation of SGG was measured . Throughout development the rates of SGG biosynthesis and net accumulation were higher in the cerebellum than in the cerebrum . The developmental patterns of SGG net synthesis in both parts of the brain were closely related to those observed earlier for sulfatide . During development the rate of SGG biosynthesis in both parts of the brain showed a peak earlier than that of sulfatide (at 14 days versus 20 days) . The in vivo patterns of SGG degradation followed those of biosynthesis in the cerebrum and cerebellum . During postnatal development 40 to 80% of the daily synthesized SGG disappeared within 24 hr, suggesting that degradation may also be involved in the regulation of SGG net synthesis during myelination, as previously indicated for sulfatide. Biomaterials, 1983 Jul, 4(3), 201 - 4 Structural peculiarities of block copolyurethanes with peptide links as rigid block extenders; Lipatova TE et al.; X-ray crystal analysis was performed on block copolyurethanes with peptide links as rigid block extenders . The increase in peptide link length was shown to improve the microphase separation of flexible and rigid segments . The influence of the isocyanate nature on phase separation conditions in the block copolyurethanes studied was established . The correlation between mechanical and temperature characteristics and peculiarities of the microphase structure was found . The latter seems especially important because of the dependence existing between the biodegradation tendency of the polyurethanes and their supermolecular organization. Appl Environ Microbiol, 1983 Jul, 46(1), 50 - 4 Anaerobic biodegradation of phenolic compounds in digested sludge; Boyd SA et al.; We examined the anaerobic degradation of phenol and the ortho, meta, and para isomers of chlorophenol, methoxyphenol, methylphenol (cresol), and nitrophenol in anaerobic sewage sludge diluted to 10% in a mineral salts medium . Of the 12 monosubstituted phenols studied, only p-chlorophenol and o-cresol were not significantly degraded during an 8-week incubation period . The phenol compounds degraded and the time required for complete substrate disappearance (in weeks) were: phenol (2), o-chlorophenol (3), m-chlorophenol (7), o-methoxyphenol (2), m- and p-methoxyphenol (1), m-cresol (7), p-cresol (3), and o-, m-, and p-nitrophenol (1) . Complete mineralization of phenol, o-chlorophenol, m-cresol, p-cresol, o-nitrophenol, p-nitrophenol, and o-, m-, and p-methoxyphenol was observed . In general, the presence of Cl and NO2 groups on phenols inhibited methane production . Elimination or transformation of these substituents was accompanied by increased methane production, o-Chlorophenol was metabolized to phenol, which indicated that dechlorination was the initial degradation step . The methoxyphenols were transformed to the corresponding dihydroxybenzene compounds, which were subsequently mineralized. J Dent Res, 1983 Jun, 62(6), 733 - 7 The development of a novel tooth-root implant material; El Basty MA et al.; Polyacrylic acid-alumina composites have been developed in this laboratory and were found to be biocompatible and resistant to biodegradation . These composites can be designed to apply a predetermined pressure on the bone interface which was found beneficial for stimulation of new bone formation and increased bone densification at the implant interface . Optimization of the physical and mechanical properties is presented, and a brief summary of the subcutaneous and oral implantation is reported. Ophthalmology, 1983 Apr, 90(4), 301 - 10 Quality control, and changing indications for lens implantation . The Seventh Binkhorst Medal Lecture-1982; Drews RC; A total of 776 specimens yielded significant data on quality control and manufacturing defects in lens implants and on the biodegradation of lens implant and suture materials . Improved quality and an understanding of durability of materials in vivo has permitted wider safe use of intraocular lenses. Chest, 1983 Apr, 83(4), 607 - 11 Glutaraldehyde-preserved porcine bioprosthesis . Factors affecting performance as determined by pathologic studies; Valente M et al.; The causes of porcine valve failure were evaluated pathologically in 129 bioprostheses (BP) removed at surgery or necropsy . Fifty-one BP had been in place for less than two months (early explants); most of the complications of this group were observed in the mitral position: left ventricular outflow obstruction (43 percent), thrombosis (23.5 percent), myocardial dysruption (20 percent), cardiac rupture (10 percent), and perivalvular leak (3.5 percent) . Among the 78 explants in place for more than two months (late explants), 66 had evidence of dysfunction . Calcification was the leading cause of failure (46 percent), followed by thrombosis (17 percent), endocarditis (12 percent), fibrous tissue overgrowth (10 percent), perivalvular leak (9 percent), and primary cusp tears (6 percent) . Calcific degeneration is a hallmark of the phenomenon of biodegradation, and experimental animal models are encouraged since they may represent the clue to preventing calcification and therefore enhancing performance and durability of the porcine BP. Biol Reprod, 1983 Feb, 28(1), 186 - 95 Poly(DL-lactide-co-glycolide)/norethisterone microcapsules: an injectable biodegradable contraceptive; Beck LR et al.; Microcapsules made from a biocompatible, biodegradable polymeric excipient, poly(DL-lactide-co-glycolide) (DL-PLGA) that contained 22 weight percent (wt %) norethisterone (NET), were prepared by a solvent-evaporation microencapsulation process . The effects of changing both the lactide-to-glycolide ratio of the DL-PLGA and the size of the microcapsules on the rate of NET release and the rate of excipient biodegradation were determined in vivo . NET release rates were determined in baboons after injecting the microcapsule formulations intramuscularly . Serum samples obtained at various times following treatment were analyzed for NET, progesterone, and estrogen by radioimmunoassay (RIA) . Biodegradation kinetics were determined by injecting NET microcapsules made from radiolabeled DL-PLGA intramuscularly into the hind legs of rats . Residual radioactivity at the injection site was determined at various times after treatment by combustion analysis of the muscle tissue . Changing the ratio of the comonomers to include more glycolide (DL-lactide:glycolide-96:4, 92:8, 87:13, 74:26) increased the rate of NET release and accelerated the biodegradation of the copolymer excipient . Decreasing the size of the microcapsules increased the rate of NET release . On the basis of these studies a NET microcapsule formulation has been identified for clinical testing which releases NET for 3 months and biodegrades completely within 6 months. Appl Environ Microbiol, 1983 Jan, 45(1), 103 - 9 Influence of spatial and temporal variations on organic pollutant biodegradation rates in an estuarine environment; Bartholomew GW et al.; The influence of spatial and temporal environmental variations on rates of organic pollutant biodegradation were assessed by using heterotrophic uptake kinetics . These studies were conducted at three sites, representing the gradient from freshwater to estuarine to marine systems . Of the compounds tested, total uptake Vmax rates decreased in the order of nitrilotriacetic acid, m-cresol, chlorobenzene, and 1,2,4-trichlorobenzene . In general, the freshwater site exhibited the highest uptake rates, with somewhat lower rates at the estuarine site . Rates at the marine site were much lower than at the other sites, except during the winter . Metabolic rates at both the freshwater and estuarine areas were significantly decreased during periods of low water temperature . Rates at the marine site were relatively uniform throughout the year . Linear regression analysis was used to compare m-cresol biodegradation rates to characteristics of the microbial community, which included direct microscopic counts, CFU counts, and cellular incorporation of amino acids . The observed rates did not consistently correlate well with any of the measured characteristics of the microbial community. Br J Anaesth, 1983, 55 Suppl 1, 3S - 10S Atracurium: conception and inception; Stenlake JB et al.; The rationale underlying the design of atracurium, a bis-quaternary ammonium neuromuscular blocking agent which incorporates the Hofmann elimination as a novel biodegradation pathway, is described . Destruction in vivo, of the bis-quaternary structure essential for neuromuscular blocking activity, by the combination of Hofmann elimination and a parallel ester hydrolysis leads to innocuous breakdown products that are without neuromuscular or cardiovascular effects and to a time-course of action which is unaffected by the level of plasma esterase activity, renal or hepatic function. Trans Am Soc Artif Intern Organs, 1983, 29, 307 - 13 Peripheral nerve repair with bioresorbable prosthesis; Nyilas E et al.; Using the transected sciatic nerve model in adult mice, regeneration of a large bundle of axons organized into the form of a nerve with myelinated and unmyelinated axons, Schwann cells, fibroblasts, collagen, blood vessels, and connective tissue sheaths has been achieved with bioresorbable microtubular guidance channels over gaps of 5 mm in nonimmobilized animals . After 4-6 wks postoperatively, the regenerated nerve cable contains on the order of 40% as many myelinated axons as were measured in the proximal nerve stumps . With the channels used so far in this model, regenerating axons pass into the distal stump in about 3-6 wks postoperatively . The guidance channels used consist of synthetic polyesters and/or polyester composites including glycolic and lactic acid polymers, and polyesters derived from Krebs Cycle dicarboxylic acids . Inflammatory response to these materials has been minimal . Biodegradation/resorption rates can be controlled so as to be compatible with axon growth rates. Ann Parasitol Hum Comp, 1983, 58(4), 353 - 9 {Possibilities of using amphoteric surface agents in the campaign against the agents of schistosomiasis transmission}; Combes C et al.; Among the chemicals which might be used against the larvas of Schistosoma, some surface active substances show some high activity at very low concentrations (0,1-5 ppm) against the miracidiums and the cercariae . The laurylamidopropylbetain has shown out of a group of products which were tested, a very high activity by lowering considerably the infection by the larvas of the hosts, like molluscs and mice, which were in contact with them . After a serie of tests made in Nigeria, these products showed a satisfactory remanence in tropical waters, in spite of the biodegradation and the adsorption on the suspended particles . It was faced to put that betain into soaps at a concentration of 5% which will permit to renew constantly the active product and which will reduce heavily any infection. Ecol Dis, 1983, 2(4), 295 - 308 Endemic goiter in western Colombia; Gaitan E; Goiter continues to occur in some areas of western Colombia despite iodine supplementation for 30 years . In 1973-1977, an average goiter prevalence of 15% (range 1-42%) still persisted among schoolchildren of 41 localities . Significant relationships were found between goiter prevalence and both the geological composition of watersheds and bacterial contamination of water supplies . Together, these associations account for 80% of the observed variation in goiter prevalence . The presence of sedimentary rocks rich in organic matter (coals, shales, etc.) was the best indicator of disease . The second best indicator, presence of K . pneumoniae in the water source, was associated with lower goiter prevalence but, as in other investigations, contamination of the pipeline system (households and schools) with gram-negative bacteria was associated with higher disease rates . Thus, epidemiological evidence indicates a cause-effect relationship between sources of drinking water and the persistence and development of goiter in this part of the world . Furthermore, identification of resorcinol, phthalate esters, and sulfur-bearing organic compounds, possibly aliphatic disulfides, in the water supplying the endemic goiter district of Candelaria town in western Colombia adds experimental support to this hypothesis . Resorcinol is derived from coal and humic substances, high molecular weight complex polymeric organic compounds present in sedimentary rocks, soils and water . Resorcinol is goitrogenic in man and experimental animals . Phthalate esters, also related to humic materials, undergo biodegradation by gram-negative bacteria with production of intermediate metabolites possessing antithyroid activity . Like phthalates and resorcinol, organic disulfides have also been identified as water contaminants in other parts of the world, and are known to be potent antithyroid compounds . The goitrogenic effect of organic and bacterial pollutants in water supplies is more pronounced in segments of the population with dietary iodine deficiency--as seen prior to the iodine prophylaxis program--and/or poor socio-economic conditions . Studies are underway to provide both insight into the biogeochemical cycle of water-borne goitrogens and knowledge essential to the development of rapid, inexpensive, and precise methods for detecting and quantifying the offending agents, as well as devising effective sanitation techniques for their inactivation and/or elimination . The impact of such measures will be determined on goiter prevalence and other parameters of health and nutrition of the communities under study.(ABSTRACT TRUNCATED AT 400 WORDS) Biomater Med Devices Artif Organs, 1983-84, 11(4), 271 - 80 Problems and challenges of biomaterials in cardiovascular applications: a status report; Bruck SD; Biomaterials used as implants and in various devices must exhibit long-term (years) compatibility with the physiological environment, including blood, and additionally must also remain stable to perform mechanical functions, excepting applications where biodegradation is required . This paper focuses on problems and challenges of polymeric materials in contact with blood in the following categories: (1) artificial heart valves, (2) cardiovascular assist devices and artificial hearts, (3) vascular prostheses, and (4) the biological evaluation of materials prior to their human use, especially with respect to species related hematological differences of experimental animals . Besides thrombosis (which is the most obvious consequence of incompatibility), the calcification of chemically treated tissue prostheses as well as synthetic elastomers used in many cardiovascular devices is discussed in terms of biochemical and physico-chemical parameters together with its significance in long-term (years) implant applications . Complement activation brought about by contact of blood with foreign surfaces has received less than deserved attention in the evaluation of biomaterials and devices, despite the potentially serious problems . Relative ignorance in selecting appropriate animals for the biological evaluation of biomaterials whose hematological profiles and behavior of platelets, red and white cells to trauma and response to foreign surfaces differ decisively from those of humans, often leads to less than meaningful predictions for eventual clinical uses . The state-of-art realities are examined in conjunction with medical, societal, ethical, and economic boundaries. Ukr Biokhim Zh, 1983, 55(3), 311 - 7 {Clinico-experimental study of the possibility of the use of immobilized enzymes for local thrombolysis and thromboformation}; Smirnov VN et al.; Fibrinolysin immobilized by a solid polysaccharide carrier capable of controllable biodegradation is shown to exert a local effective thrombolyzing action . Certain results of clinical studies of immobilized streptase (streptodecase) are presented . They show essential advantages of the new preparation over the known native enzymes . Experiments with animals show that the immobilized thrombin may be applied in therapeutic embolization for the hemorrhage cessation. J Environ Sci Health B, 1983, 18(1), 147 - 72 Biochemical toxicology of lindane and its analogs; Nakajima M; The inhibitory potencies of BHC isomers against Na+-K+- ATPase, yeast growth and nerve conduction of the American cockroach were determined . The insecticidal and neuroexcitatory activities of a number of analogs with the same configuration as lindane in which some chlorine atoms had been replaced by other substituents were also examined against American cockroaches . The structure-activity relationships and the mode of action of lindane and its analogs were discussed . Their metabolic fate was studied extensively in vivo as well as in vitro . The critical step in the biodegradation of lindane is the cleavage of C-H bonds which we found by utilizing the isotope effect of hexadeuterated lindane. FEBS Lett, 1982 Dec 13, 150(1), 211 - 3 Inactivation of spermidine N1-acetyltransferase with alkaline phosphatase; Matsui I et al.; Spermidine N1-acetyltransferase in an extract from phytohemagglutinin-stimulated bovine lymphocytes was inactivated by preincubation with alkaline phosphatase . Inactivation of the acetylase with the phosphatase was totally inhibited by addition of pyrophosphate . These results suggest that spermidine N1-acetyltransferase, the rate-limiting enzyme in the biodegradative pathway of polyamines, is inactivated by dephosphorylation . A similar effect of alkaline phosphatase on the acetylase in an extract from Escherichia coli was also observed . The acetylase has a rapid rate of turnover and the rapid loss of the enzyme activity may be to some extent regulated by the covalent modification. Mikrobiologiia, 1982 Nov-Dec, 51(6), 1005 - 7 {Aromatic hydrocarbons as enzyme inducers of cleavage of the aromatic ring in Candida guilliermondii}; Ismailov NM; Monocyclic and dicyclic aromatic hydrocarbons, toluene and 2-methylnaphthalene, can induce pyrocatechate-1,2-oxygenase in Candida guilliermondii BKM Y-916 cells . The enzyme is active at pH 7.0 . The culture oxidizes toluene via benzoic acid by ortho-cleavage . The results indicate that Candida as an ecologo-trophic group of microorganisms can be involved, along with bacteria, in biodegradation of various aromatic hydrocarbons. J Biol Chem, 1982 Oct 10, 257(19), 11455 - 62 The involvement of hydroxyl radical derived from hydrogen peroxide in lignin degradation by the white rot fungus Phanerochaete chrysosporium; Forney LJ et al.; The possible involvement of hydrogen peroxide (H2O2)-derived hydroxyl radical (.OH) in lignin degradation ({14C}lignin leads to 14CO2) by Phanerochaete chrysosporium was investigated . When P . chrysosporium was grown in low nitrogen medium (2.4 mM N), an increase in the specific activity for H2O2 production in cell extracts was observed to coincide with the appearance of ligninolytic activity and both activities appeared after the culture entered stationary phase . The production of .OH in ligninolytic cultures of P . chrysosporium was demonstrated by alpha-keto-gamma-methiolbutyric acid-dependent formation of ethylene . Hydrogen peroxide-dependent .OH formation was also shown in cell extracts of ligninolytic cultures . The radical species was demonstrated to be .OH by the .OH-dependent hydroxylation of p-hydroxybenzoic acid to form protocatechuic acid and by using 5,5-dimethyl-1-pyrroline-N-oxide and detecting the production of the nitroxide radical of 5,5-dimethyl-1-pyrroline-N-oxide by EPR . These reactions were inhibited by .OH-scavenging agents and were stimulated when azide was added to inhibit endogenous catalase . Lignin degradation by P . chrysosporium was markedly suppressed in the presence of the .OH-scavenging agents mannitol, benzoate, and the nonspecific radical scavenging agent butylated hydroxytoluene . The above results indicate that .OH derived from H2O2 is involved in lignin biodegradation by P . chrysosporium. Arch Pathol Lab Med, 1982 Oct, 106(10), 490 - 6 Structural changes of glutaraldehyde- treated porcine bioprosthetic valves; Camilleri JP et al.; Gross anatomic, histologic, and transmission and scanning electron microscopic observations were made of 29 bioprosthetic valves that had been implanted in patients for up to 115 months . On the basis of these morphologic data, no significant evidence of tissue rejection was seen . However, the durability of these valve bioprostheses is still questionable . Our observation primarily emphasize three factors: (1) disruption of the endothelial cell barrier and the lack of significant host endothelialization even 115 months after transplantation; (2) increased permeability that eased diffusion of circulating host plasma proteins into valve tissue, and increased activity of infiltration processes, eg . calcification and lipid accumulation; and (3) biodegradation of the collagen framework . Each of these factors may contribute further to valve dysfunction . Development of an intimal fibrous sheath seems to occur in porcine bioprostheses that have been implanted for the longest periods of time, but the rate of host tissue ingrowth varies. Hum Pathol, 1982 Oct, 13(10), 878 - 81 IUDs, inflammation, and infection: assessment after two decades of IUD use; Schmidt WA; PIP: In the 1950s social and technological changes allowed experimental use of an inert plastic IUD which was successful and regarded as safe . The devices were pliable, chemically inert, sterilizable, disposable, and equipped with a small inserter so that cervical dilation was not needed for insertion . But many IUDs were withdrawn because they were found to cause endometritis and provide poor protection against pregnancy . In the 1970s there were cases of serious inflammatory and infectious diseases with pelvic inflammatory disease (PID) the most common . The Dalkon Shield has been associated with midtrimester septic abortions and with unilateral actinomycotic tube-ovarian abscesses and there is evidence to support a chemically caused IUD-related endometritis in the moderate inflammation associated with IUDs containing copper and with the Majzlin spring . The most common factor among IUD users with Actinomycetales infection is not the type of IUD but the duration of use; almost 85% of cases were in women who had worn IUDs over 3 years . Also the likelihood of an ectopic pregnancy is almost 3 times greater for longterm IUD users . It is hypothesized that with time the IUD is capable of inducing changes that can lead to infection and that changes can occur to the IUD itself . A surface coating on the IUD and the tail has been found which is composed of mucoid and cellular elements which consist of an inflammatory response; the IUD then becomes recognized as a foreign body to the host and may contribute to the development of PID . Other problems such as perforation, cramping, bleeding, and unwanted pregnancy may be at least indirectly related to IUD surface alterations . It is now agreed that all IUD-associated inflammatory and infectious disease can no longer be considered gonorrheal type PID and that the biodegradation of the nylon-6 tail of the Dalkon shield may also be a factor in PID . Some recommendations are to: 1) change IUDs every 2 years, 2) counsel women on IUD complications and examine IUDs upon removal, and 3) bring IUD technology up to date to develop an IUD that is thoroughly safe and effective . Appl Environ Microbiol, 1982 Aug, 44(2), 514 - 6 Biodegradation of 2,4,5-trichlorophenoxyacetic acid in soil by a pure culture of Pseudomonas cepacia; Chatterjee DK et al.; A pure culture of Pseudomonas cepacia AC1100 was able to degrade and grow in presence of 2,4,5-trichlorophenoxyacetic acid in soil . At optimum temperature (30 degrees C) and moisture content (15 to 50% {wt/vol}) strain AC1100 could degrade as much as 95% of 2,4,5-trichlorophenoxyacetic acid at high concentration (1 mg/g of soil) within 1 week. Appl Environ Microbiol, 1982 Aug, 44(2), 321 - 9 Heterotrophic activity and biodegradation of labile and refractory compounds by groundwater and stream microbial populations; Ladd TI et al.; The bacteriology and heterotrophic activity of a stream and of nearby groundwater in Marmot Basin, Alberta, Canada, were studied . Acridine orange direct counts indicated that bacterial populations in the groundwater were greater than in the stream . Bacteria that were isolated from the groundwater were similar to species associated with soils . Utilization of labile dissolved organic material as measured by the heterotrophic potential technique with glutamic acid, phenylalanine, and glycolic acid as substrates was generally greater in the groundwater . In addition, specific activity indices for the populations suggested greater metabolic activity per bacterium in the groundwater . 14C-labeled lignocellulose, preferentially labeled in the lignin fraction by feeding Picea engelmannii {14C}phenylalanine, was mineralized by microorganisms in both the groundwater and the stream, but no more than 4% of the added radioactivity was lost as 14CO2 within 960 h . Up to 20% of {3'-14C}cinnamic acid was mineralized by microorganisms in both environments within 500 h . Both microbial populations appear to influence the levels of labile and recalcitrant dissolved organic material in mountain streams. Appl Environ Microbiol, 1982 Jul, 44(1), 72 - 8 Biodegradation of 2,4,5-trichlorophenoxyacetic acid by a pure culture of Pseudomonas cepacia; Kilbane JJ et al.; A pure culture of Pseudomonas cepacia, designated AC1100, that can utilize 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as its sole source of carbon and energy was isolated . An actively growing culture of AC1100 was able to degrade more than 97% of 2,4,5-T, present at 1 mg/ml, within 6 days as determined by chloride release, gas chromatographic, and spectrophotometric analyses . The ability of AC1100 to oxidize a variety of chlorophenols and related compounds is also reported. Appl Environ Microbiol, 1982 Jul, 44(1), 159 - 64 Measurement of aquatic biodegradation rates by determining heterotrophic uptake of radiolabeled pollutants; Pfaender FK et al.; The heterotrophic uptake technique was modified to provide a rapid and simple technique for estimating the rates of biodegradation of organic pollutants under environmental conditions . The methodology is based on an evaluation of uptake into cells and subsequent respiration of radiolabeled organic substrates in short-term experiments . The resulting data can be used to calculate either turnover times or, if multiple concentrations of substrate are used, kinetic parameters . The procedure was applied to assess the biodegradation rates of m-cresol, chlorobenzene, nitrilotriacetic acid, and 1,2,4-trichlorobenzene in fresh, brackish, and marine water samples from the coastal areas of North Carolina . Saturation kinetics for uptake were obtained with each of the compounds tested . Rates of metabolism were shown to be dependent on sample location and time of year. Appl Environ Microbiol, 1982 Jul, 44(1), 113 - 20 Enhanced biodegradation of methoxychlor in soil under sequential environmental conditions; Fogel S et al.; Ring-U-{14C}methoxychlor {1,1-bis(p-methoxyphenyl)-2,2,2-trichloroethane} was incubated in soil under aerobic and anaerobic conditions . Primary degradation of methoxychlor occurred under anaerobic conditions, but not under aerobic conditions, after 3 months of incubation . Analysis of soil extracts, using gas chromatography, demonstrated that only 10% of the compound remained at initial concentrations of 10 and 100 ppm (wt/wt) of methoxychlor . Evidence is presented that a dechlorination reaction was responsible for primary degradation of methoxychlor . Analysis of soils treated with 100 ppm of methoxychlor in the presence of 2% HgCl2 showed that 100% of the compound remained after 3 months, indicating that degradation in the unpoisoned flasks was biologically mediated . Methanogenic organisms, however, are probably not involved, as strong inhibition of methane production was observed in all soils treated with methoxychlor . During the 3-month incubation period, little or no evaluation of 14CO2 or 14CH4 occurred under either aerobic or anaerobic conditions . Cometabolic processes may be responsible for t