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Background: Prostate specific antigen (PSA) is a well-established marker of prostate cancer, but it can also degrade extracellular matrix proteins such as fibronectin and could be involved in tumor progression and metastasis. In this study, we have addressed the use of boric acid and 3-nitrophenyl boronic acid (NPBA) as PSA inhibitors in vitro., Methods: The inhibition of PSA by boric acid was studied by using specific fluorogenic substrates. Fibronectin, a biologically relevant substrate for PSA, was used as a substrate in a zymographic assay, and the degradation of fibronectin by PSA in the presence of boric acid and NPBA was followed by Western Blot., Results: Low concentrations of boric acid partially inhibited the proteolytic activity of PSA toward a synthetic fluorogenic substrate. Also, by Western blot, we have found significant inhibition in the proteolysis of fibronectin by PSA in the presence of boric acid as well as NPBA. Results indicate that the boronated compounds used in this study can be used for the modulation of PSA activity., Conclusion: PSA activity is inhibited in vitro by boric acid and NPBA. If degradation of fibronectin by PSA were, in fact, an important step in the progression of prostate cancer, then borate-induced inhibition of PSA activity should help reduce the development and proliferation of prostate carcinomas., (Copyright 2002 Wiley-Liss, Inc.)

The effect of compounds on the motility of Proteus mirabilis swarmer cells varies from one strain to another. The effect of compounds on the motility of swarmer cells is mainly at higher concentrations than the concentration used to inhibit swarming. Boric acid only affects the motility of strain G9 swarmer cells, whereas sodium deoxycholate prevented the motility of swarmer cells for three strains. Some antibiotics show their effect on the motility of swarmer cells in anaerobic areas, by slowing the movement of swarmer cells, followed by stopping the movement after a period of time or disappearance of the cells. The differentiation between the strains of Proteus species seems to be better in liquid suspension than on the solid medium.

Boron (B)-deficient pumpkin (Cucurbita moschata Duchesne) plants exhibit reduced growth, and their tissues are brittle. The leaf cell walls of these plants contain less than one-half the amount of borate cross-linked rhamnogalacturonan II (RG-II) dimer than normal plants. Supplying germanium (Ge), which has been reported to substitute for B, to B-deficient plants does not restore growth or reduce tissue brittleness. Nevertheless, the leaf cell walls of the Ge-treated plants accumulated considerable amounts of Ge. Dimeric RG-II (dRG-II) accounted for between 20% and 35% of the total RG-II in the cell walls of the second to fourth leaves from Ge-treated plants, but only 2% to 7% of the RG-II was cross-linked by germanate (dRG-II-Ge). The ability of RG-II to form a dimer is not reduced by Ge treatment because approximately 95% of the monomeric RG-II generated from the walls of Ge-treated plants is converted to dRG-II-Ge in vitro in the presence of germanium oxide and lead acetate. However, dRG-II-Ge is unstable and is converted to monomeric RG-II when the Ge is removed. Therefore, the content of dRG-II-Ge and dRG-II-B described above may not reflect the actual ratio of these in muro. (10)B-Enriched boric acid and Ge are incorporated into the cell wall within 10 min after their foliar application to B-deficient plants. Foliar application of (10)B but not Ge results in an increase in the proportion of dRG-II in the leaf cell wall. Taken together, our results suggest that Ge does not restore the growth of B-deficient plants.

Sixty-four patients with symptomatic otomycosis (80 infected ears) confirmed by direct microscopy and culture were randomly treated for I week with ciclopiroxolamine cream 11% (group A, 20 infected ears, 17 patients), ciclopiroxolamine solution 1% (group B, 20 infected ears, 17 patients) and boric acid (group C, 40 infected ears, 30 patients) and daily mechanical suction aspiration of the debris. An attempt was made to match 11 clinical parameters with both the mycological and bacteriological findings. There was no significant association between the fungal species cultured and the clinical parameters did not vary with the presence or absence of different bacteria; pus was never present in fungal otitis externa (Fisher's test, P < 0.001). Before therapy, a significant number of ears had completely sterile bacterial cultures (p < 0.01, chi2 test); saprophytic Gram-positive bacteria increased after treatment, whilst Gram-negative bacteria, Pseudomonas aeruginosa and Proteus species, decreased after treatment. Clinical total cure rates 3 days after the end of therapy ranged from 50% in group A, 25% in group B to 22.5% in group C. Mycological cure rates were 80% (group A), 95% (group B) and 72.5% (group C). Two weeks after the end of therapy the clinical cure rates were 60% (group A), 65% (group B) and 80% (group C) and the mycological cure rates was 65% for group A and 75% for both group B and C. Eleven patients relapsed with otitis externa: four (20%) in groups A and C and three (15%) in group B. In four cases the infection was due to bacteria and the remaining seven were due to fungi. Six sites relapsed with the same fungal species as that isolated at the start of the study. In this short-term assessment the relapse rate was not significantly associated with predisposing conditions. The tolerance was excellent in group A. Four patients (20%) in group B had mild (two patients) or moderate (two patients) burning and itching with each application. Twelve patients (30%) in group C had severe stinging and five of these patients who had perforated tympanic membranes also experienced pain. In terms of clinical and mycological effectiveness, there were no significant differences between the three treatment groups, although group A (ciclopiroxolamine cream 1%) and B (ciclopiroxolamine solution 1%) both showed significantly better tolerance (Fisher's test, P < 0.05) when compared with boric acid (group C).

To establish the best method for boric acid susceptibility testing, we compared two agar dilution methods (high and low inoculum) and a standard broth microdilution method (from the National Commitee for Clinical Laboratory Standards document NCCLS M-27A). Saccharomyces cerevisiae (37) and non-C. albicans Candida (39) isolates, as well as one isolate of Trichosporon sp., were included. All were isolated from female workers with vulvovaginitis. Good agreement within a fourfold dilution range was found between the three methods, and only the broth microdilution method versus the agar dilution method with high inoculum showed significant discrepancies. Reading results was easier with the broth microdilution method than with the agar dilution methods because of partial growth inhibition in the latter. In conclusion, broth microdilution is a suitable method for testing yeast susceptibility to boric acid.

It has been shown that boric acid has well-defined biological effects such as stimulation of wound healing in vivo, release of growth factors and cytokines, and increase of the extracellular matrice turnover. We examined its action at the molecular level, using cell-free systems of transcription (isolated placenta nuclei) and translation (wheat germ extract). We found that 10 mM boric acid greatly increased RNA synthesis, measured by absorbance at 260 nm (x 6.4) or by [3H]-UTP uptake (x 11). Full-length functional mRNA was produced because proteins of 14-80 kDa were translated. Among these proteins, factors involved in angiogenesis and, subsequently, in wound healing (VEGF and TGFbeta) were identified by slot blot, whereas growth factors such as FGF1 and TNFalpha were not detected. These results demonstrate that boron may contribute to biological cell activities at both the transcription and translation levels. However, the mechanism of action is still not known.

Pestiferous cockroach species are associated closely with humans and are important from medical and public health points of view. Conventional insecticides have been used widely to control cockroaches which have developed resistance to these compounds. Thus, interest has again centered on lesser-used compounds such as boric acid. Boric acid has been used as an insecticide for many years, especially against cockroach. Its mode of action on insects has not been satisfactorily established. In Algeria, Blattella germanica (Dictyoptera: Blattellidae) is a serious pest in the urban environment and their infestation were controlled for many years by organophosphate, carbamate or pyrethroid insecticides. In order to obtain more information on the mode of action of boric acid, we first evaluated the oral toxicity of boric acid on B. germanica adults. Then, the compound was determined in several organs by an colorimetric method. This insecticide was incorporated into the diet and orally administered at different concentrations ranging from 1 to 40% (w/w) to newly emerged adults. Mortality was recorded at different times during treatment (24, 48, 72 and 144 h). Treatment resulted in a dose-dependent mortality since the LD50 (%) recorded are 85 at 24 h, 67 at 48 h, 39 at 72 h and 8 at 144 h, respectively. Then the quantity of boric acid accumulated in several organs (hemolymph, gut, ovaries, testicles and fat body) was determined as function the duration of treatment (1 to 5 days) for two doses (LD50 and LD90). Results revealed that bioaccumulation of residues in these organs increased as function the duration of treatment. In addition, relatively important amounts of residues, are detected in fat body.

As indicated by recent measurements of the electrophoretic free solution mobility, DNA appears to have a greater helical charge density in Tris-borate-EDTA (TBE) buffers than in Tris-acetate-EDTA (TAE) buffers. Since electrostatic forces play a major role in DNA packaging processes, we have investigated the condensation of closed circular plasmid DNA using total intensity and dynamic light scattering in Tris-borate, Tris-acetate, and Tris-cacodylate buffers with cobaltic hexa-amine (III) [Co(NH(3))(3+)(6)]. We find that neither the critical concentration of Co(NH(3))(3+)(6) nor the hydrodynamic radii of the resulting condensates vary significantly in the buffer systems studied here despite the prediction that DNA condensation should occur at significantly lower Co(NH(3))(3+)(6) concentrations in Tris-borate buffers. Assuming a persistence length behavior similar to B-DNA in the presence of multivalent cations, a decrease in the attractive counterion correlation pressure decay length in Tris-borate buffers does not account for our observations. It is possible that the binding of multivalent cations to DNA may hinder borate association with the DNA double helix., (Copyright 2000 John Wiley & Sons, Inc.)

Boric acid solution (3%) dramatically improves wound healing through action on the extracellular matrix, a finding that has been obtained in vitro. Consequently, investigations are presently underway to produce boronated compounds having a therapeutical effectiveness similar to that of boric acid. On the basis of experimental results obtained with boric acid, we examined the effects of boron derivatives on extracellular matrix formation and degradation and analyzed their potential toxicity by using two biological models (chick embryo cartilage and human fibroblasts). The four boron derivatives tested in this study (triethanolamine borate; N-diethyl-phosphoramidate-propylboronique acid; 2,2 dimethylhexyl-1,3-propanediol-aminopropylboronate and 1,2 propanediol-aminopropylboronate) mimicked the effects of boric acid. They induced a decrease of intracellular concentrations in extracellular matrix macromolecules (proteoglycans, proteins)-associated with an increase of their release in culture medium and stimulated the activity of intra- and extracellular proteases. Similarly to boric acid, these actions occurred after exposure of the cells to concentrations of all boron derivatives without apparent toxic effects. The compounds were found to be more toxic than boric acid itself when concentrations were calculated according to their molecular weight. Nevertheless, these in vitro preliminary results demonstrate effects of boron derivatives that may be of therapeutic benefit in wound repair.

The free solution electrophoretic mobility of DNA differs significantly in different buffers, suggesting that DNA-buffer interactions are present in certain buffer systems. Here, capillary and gel electrophoresis data are combined to show that the Tris ions in Tris-acetate-EDTA (TAE) buffers are associated with the DNA helix to approximately the same extent as sodium ions. The borate ions in Tris-borate-EDTA (TBE) buffers interact with DNA to form highly charged DNA-borate complexes, which are stable both in free solution and in polyacrylamide gels. DNA-borate complexes are not observed in agarose gels, because of the competition of the agarose gel fibers for the borate residues. The resulting agarose-borate complexes increase the negative charge of the agarose gel fibers, leading to an increased electroendosmotic flow of the solvent in agarose-TBE gels. The combined results indicate that the buffers in which DNA is studied cannot automatically be assumed to be innocuous., (Copyright 2000 John Wiley & Sons, Inc.)

Strain differentiation of 66 clinical isolates of Candida albicans obtained from healthy dentate and complete denture wearers was performed. Resistogram method based on differences in the resistance of C. albicans isolates to sodium selenite, boric acid, cetrimide, sodium periodate and silver nitrate was used for strain differentiation. Of the 32 potential strains that can be distinguished, 14 different resistogram strains of C. albicans were found among the 66 isolates tested. Strain-C--was the most predominant (24.3% of total isolates), while strain A-CDE was the least predominant (1.5%). The results showed no particular association of certain strains with Candida infections in complete denture wearers. Sensitivity to antifungal agents showed that isolates from different strains were most sensitive to amphotericin B and nystatin and least sensitive to miconazole.

Positional distribution of fatty acids in triacyl-sn-glycerols of docosahexaenoic acid (DHA)-rich tuna orbital and bonito head oils has been reanalyzed by a method based on chromatographic separation of isomeric and enantiomeric monoacyl-sn-glycerol (MAG) derivatives. When boric acid thin-layer chromatography (TLC) was used for separation of 1(3)- and 2-MAG analytical intermediates, the stereospecific analysis showed the preferential association of DHA to the sn-2 position followed by the sn-3 position. This distribution pattern differed from that obtained by silicic acid TLC of their bis-3,5-dinitrophenylurethane (DNPU) derivatives. Reversed-phase high-performance liquid chromatography elution profiles of 1(3)- and 2-MAG intermediates revealed that 1(3)- and 2-MAG made up of both short- and long-chain lengths cannot be clearly resolved by TLC after preparation of the DNPU derivatives. The 1(3)- and 2-MAG must be resolved by boric acid TLC prior to derivatization.

Aim: To investigate the effect on urine culture results and their clinical interpretation of delaying the processing of urine samples in which boric acid had been used as a preservative., Methods: 792 mid-stream specimens of urine from patients attending their general practitioner were received in borate containing plastic jars. The specimens were cultured upon receipt, stored at room temperature, and then recultured the following morning., Results: After overnight delayed culture, the results were altered in 16% of samples and the clinical interpretation of these findings differed in 8% of specimens. In 28 samples (3.5%) the bacterium isolated on initial culture was not the same as that obtained by culture after overnight storage., Conclusions: Boric acid urine preservation used for overnight delayed processing of samples is associated with a significant alteration in culture results and the attendant clinical interpretation of such specimens. Rapid transportation/processing of urine specimens must remain the optimum procedure.

The aim of this study was to determine the antifungal susceptibility of 108 Candida albicans and 23 Candida glabrata isolates obtained from female prostitutes with vulvovaginitis, a population for which available data is limited. Amphotericin B, flucytosine, and fluconazole were tested by broth microdilution, and boric acid was tested by the agar dilution method. The susceptibility patterns found in this population were the same as those in the general population. Candida glabrata required greater concentrations of boric acid for inhibition in vitro than did Candida albicans.

The inhibitory effects of a new boron compound of guanidine biboric acid adduct (GB) and guanidium chloride (L1) on the growth of ascites tumour in female Swiss mice were studied by monitoring the survival, tumour weight, tumour cell count, transplantability of Ehrlich ascites cells, precursor incorporation and the haematological parameters of the treated mice. 5-Fluorouracil, a known anticancer drug, was used as a positive control. The most important parameter was the survival time, which increased significantly when tumour-bearing mice were treated with the boron compound. Haematological parameters of the treated animals showed minimum toxic effects when boron was coupled with guanidine.

Boric acid was not mitogenic for human fibroblasts and it did not change cell viability until 0.5% (w/v). Boric acid treatment affected the metabolism of human dermal fibroblasts in culture, decreasing the synthesis of extracellular matrix macromolecules such as proteoglycans, collagen, and total proteins. It also increased the release of these molecules into the culture medium. The principal proteins secreted into the medium after boric acid treatment had molecular masses of 90, 70, 58, 49, and 43 kDa and faint bands were detected by electrophoresis between 14 and 30 kDa. hsp 70 and TNF alpha were detected among the secreted proteins by immunoblotting, and the amount of TNF alpha released was quantified by radioimmunoassay. Total mRNA levels were higher after boric acid treatment and peaked after 6 h of treatment. TNF alpha mRNA was undetectable in unstimulated fibroblasts and two TNF alpha mRNA bands were detected after stimulation: immature mRNA (4.8 kb) and mature TNF alpha mRNA (1.9 kb). Thus, the effects of boric acid observed in wound repair in vivo may be due to TNF alpha synthesis and secretion.

An ethyleneimine and UV irradiated mutant strain Aspergillus niger AB 1801 was explored for its aconitase activity, citric acid production and cell growth during citric acid fermentation. 10% sucrose and 0.25% urea served as the best carbon and nitrogen sources, respectively. Fe2+ stimulated aconitase activity and Co2+ (upto 5 micrograms/mL) and Ni2+ (10 micrograms/mL) strongly depressed enzyme activity. Boric acid (0.5 mg/L) had very good stimulatory response towards citric acid production. Aconitase activity has been found to vary inversely with the citric acid production upto a certain limit after which the activity was absent in the mycelial extract. Cell growth varied with the production parameter.

CHO cells were exposed to thermal neutrons and their mutation frequency was determined. The Kyoto University Research Reactor (KUR), which has a very low level of contamination by gamma-rays and fast neutrons was used as a thermal neutron source. Cells were irradiated in the presence or absence of boric acid to determine mutation frequency and cell survival. Thermal neutron irradiation was 2.5 times as mutagenic as gamma-irradiation without boron. In the presence of boron, however, thermal neutron irradiation was from 4.2 to 4.5 times as mutagenic as gamma-irradiation. When the mutation frequency was plotted against the survival fraction, a higher degree of mutagenicity was observed in the presence than in the absence of boron. These results suggest that the enhancement of thermal neutron-induced mutation with boron is strongly associated with alpha-particles released by 10B(n, alpha)7 Li reaction.

Pelvic cartilage of chick embryo was used to demonstrate that presence of boron in culture medium decreases synthesis of proteoglycans, collagen and total proteins but on the other hand increases the release of these macromolecules. However, when glucose concentration in culture medium is brought to 22mM, the synthesis decrease is no longer observed, whereas release increase persists. Proteins released into the culture medium included heat shock proteins (70 hsp) and tumor necrosis factor alpha (TNF alpha). The amount of phosphorylated proteins was enhanced in presence of boron while endoprotease activity in cartilage and in culture medium was significantly augmented. The in vitro effects of boric acid may explain its in vivo effect on wound healing.

Previous studies from our laboratory found that when boric acid (BA) was administered in the diet to rats, boron levels in bone were approximately fourfold greater than serum levels. The current studies were undertaken to determine if these elevations produced adverse effects on several bone-related measures, including serum electrolyte levels, bone structure, and bone strength. Data from two studies are presented: in the first study, young adult male rats consumed a powdered diet containing 0, 3000, 4500, 6000, or 9000 ppm BA for 9 weeks. Endpoints were serum calcium, phosphorous, potassium, and chloride, as well as blood and bone boron concentrations ([B]) measured weekly during the 9-week exposure period, and at 8, 16, 24, and 32 weeks after the end of exposure. In the second study, the male and female young adult rats diet contained 0, 200, 1000, 3000, or 9000 ppm BA for 12 weeks; endpoints measured weekly were serum levels of calcium, phosphorous, and magnesium, bone [B], and bone structure (humerus) and strength (tibia, femur, and lumbar vertebrae). In treated rats, calcium was reduced in the first study but not the second. Serum phosphorous was reduced in both studies; potassium was unchanged, chloride was increased by 1%, and magnesium was reduced in all BA-exposed groups in the second study, to a maximal 19% reduction. Bone [B] was consistently increased in all treated groups, to concentrations approximately fourfold those of serum. After cessation of exposure, serum and urinary boron concentrations dropped to within control values within a week. However, even 32 weeks after the end of exposure, bone [B] remained threefold greater than controls. Male tibia and femur resistance to bending was unchanged. However, vertebral strength in compression was significantly increased by 5-10% in all dose groups (200 to 9000 ppm). The pattern was substantially similar in females. Only the humerus was examined by light microscopy and was found to be unchanged at any level of BA consumption. These data show that, despite a reduction in some serum electrolyte levels, BA consumption increased vertebral resistance to crush force, without detectably altering the microscopic structure of the humerus or the resistance of femur and tibia to a bending load. This increase in compression resistance occurred at exposure levels substantially below those that were previously reported to be reproductively toxic.

A total of 53 oral Candida albicans isolates from Chinese patients with clinically diagnosed oral candidosis (27 patients) or without overt signs and mycological manifestations of infection (26) were biotyped using two commercially available API micromethod kits and a boric acid-resistance test. There were no significant differences in the biotypes in health and disease, although the biotype A1R was present only in diseased individuals. The biotype A1S accounted for 21% of the total isolates, as in a number of other previous studies from the West. However, 14 of the 27 biotypes characterized were new biotypes that have not been described before. These preliminary data indicate that biotypic profile of C. albicans may bear no relation to the virulence of the isolates, and that diverse subtypes of the fungus are globally prevalent.

Since the use od phenolic disinfectants for impregnating and disinfecting of wood in mushroom--growing cellars was banned in Poland for ecologic and hygienic reasons, the new product, namely Mycetox, containing quaternary ammonium compound and boric acid has been registered for this purpose. Mycetox belongs to new generation products and is non toxic for man and the environment. It is first Polish product developed for the general disinfection as well as for impregnating purposes in mushroom farms. The efficacy of Mycetox in mushroom-growing cellars has been evaluated basing on its fungicidal properties in the different substrates used for the cultivation of mushrooms. Also its influence on mushroom spawn growth, crop yield, and the penetration of spawn into wooden cages impregnated with Mycetox as well as its influence on blanching of mushrooms has been investigated.

Plasma membrane electron transport reactions and associated proton secretion were studied in boron-deficient carrot cells. It was found that the hormone-sensitive plasma membrane NADH oxidase was inhibited by boron deficiency and that under such conditions activity could be restored by exogenous boric acid with or without 2,4-dichlorophenoxy acetic acid. Gramicidin, a channel-forming protonophore, further stimulated NADH oxidase by carrot cells. Proton secretion, associated with plasma membrane H(+)-ATPase, was also affected by boron deficiency, but not as severely as ferricyanide-generated proton secretion, reflecting plasma membrane electron transport. The addition of 1 mM boric acid and 1 microM 2,4-dichlorophenoxy acetic acid to carrot cells fully restored the H+ secretion in presence of ferricyanide. The effect of boron deficiency in cultured carrot cells can, therefore, be directly associated with cell growth through its effect on the plasma membrane NADH oxidase and H+ secretion. Ferricyanide provides a probe which activates transmembrane electron transport that is only coupled to proton release when boron is present.

Feeding behavior in hydra is initiated by the association of glutathione (GSH) with a putative external chemoreceptor. In the present study, the binding of [35S]GSH to hydra membranes has been characterized. Nondisplaceable [35S]GSH binding which compromised previous analyses [Grosvenor, W., Bellis, S., Kass-Simon, G., & Rhoads, D. (1992) Biochim. Biophys. Acta (in press)] was eliminated by treating membranes with an inhibitor of GSH metabolism, borate in combination with L-serine. The specific binding which was not inhibited by borate/serine demonstrated many of the characteristics expected of a ligand/receptor interaction. The binding was rapid, reversible, and saturable. A Scatchard analysis of saturation isotherms indicated a dissociation constant (KD) of 3.4 microM, a value which is in good agreement with concentrations of glutathione which are known to induce feeding behavior. Hydra membranes were detergent-solubilized with 10 mM 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), 100 mM KCl, and 10% glycerol. The soluble fraction contained 40% of the original saturable, reversible GSH binding activity. The KD for GSH binding to the solubilized preparation was estimated as 2.7 microM, a valuable which is not appreciably different from the KD for binding to intact membranes. The fidelity of GSH binding in the solubilized preparation suggests that this preparation will be useful in further characterization of the putative glutathione chemoreceptor.

The occurrence of aflatoxins in market betel nut samples was studied. It was observed that several betel nut samples were infested with aflatoxin-producing fungus, Aspergillus flavus. Out of 32 samples collected from various places, 12 were positive for aflatoxin. Aflatoxin B1 was detected in all the positive samples. Other aflatoxins were also detected in some samples. Boric acid, propionic acid and potassium metabisulphite were used for the control of aflatoxin B1 on betel nuts. Propionic acid was most effective in inhibiting aflatoxin production on betel nut after intervals of 2 (62%) and 4 (85%) weeks. Controlling the occurrence of aflatoxin could safeguard the users from the health hazards of aflatoxins.

4-Substituted styrylglyoxals have been synthesized and found to benefit from borate catalysis to serve as highly reactive arginine modifiers. A study of the mechanism in arginine modification has affirmed: (i) the role of electronic effects in modulating the arginine reactivity in alpha-dicarbonyls, (ii) the intermediacy in the reaction of a reversible arginine-alpha-dicarbonyl complex and (iii) the identity of the nucleophilic attack at ketone as the rate determining step in the arginine reaction with arylglyoxals. 4-Methoxystyrylglyoxal and 4-(N,N-dimethylamino)phenylglyoxal were used as the probes in analyzing some representative enzymes for the reactivities of their susceptible arginyls. The susceptible arginyls in lactate and malate dehydrogenases were thus found to be appreciably reactive while those in carboxypeptidase-A and pyruvate kinase were only moderately reactive.

We have developed techniques for the separation of unsulfated (2-acetamido-2-deoxy-3-O-(4-deoxy-alpha-L-threo- hex-4-enopyranosyluronicacid)-D-galactose and -D-glucose), monosulfated (2-acetamido-2-deoxy-3- O-(4-deoxy-2-O-sulfo-alpha-L-threo-hex-4-enopyranosyluronic acid)-D-galactose and 2-acetamido-2-deoxy-3-O-(4-deoxy-alpha-L-threo-hex- 4-enopyranosyluronic acid)-4-sulfo-D-galactose and -6-sulfo-D-galactose),disulfated (2-acetamido-2-deoxy-3-O-(4-deoxy-2-O-sulfo-alpha-L-threo-hex-4- enopyranosyluronic acid)-4-sulfo-D-galactose and -6-sulfo-D-galactose and 2-acet-amido-2-deoxy-3-O-(4-deoxy-alpha-L-threo-hex-4-enopy- ranosyluronic acid)-4,6-di-O-sulfo-D-galactose), and trisulfated (2-acetamido-2-deoxy-3-O-(4-deoxy-2-O- sulfo-alpha-L-threo-hex-4-enopyranosyluronic acid)-4,6-di-O-sulfo-D-galactose) isomers of chondroitin using capillary zone electrophoresis. In addition, it is possible to separate oligomers of hyaluronan by similar protocols. These techniques represent a rapid, sensitive, and reproducible technique for the assay of these molecules from digests of connective tissues.

The pH-rate profile for inactivation of the RTEM-1 cysteine beta-lactamase by iodoacetate supports previous evidence [Knap & Pratt (1989) Proteins Struct. Funct. Genet. 6, 316-323] for the activation of the active-site thiol group by adjacent functional groups. The enhanced reactivity of iodoacetate, with respect to that of iodoacetamide, suggests the influence of a positive charge in the active site. The reactivity of iodoacetate is not affected by dissociation of an active-site functional group of pKa 6.7, which increases the reactivity of neutral reagents, probably because of a compensation phenomenon; it is, however, lost on dissociation of an acid of pKa 8.1. It is concluded that the active cysteine beta-lactamase has four functional groups at the active site, one nucleophilic thiolate of Cys-70, one neutral acid (most probably the carboxy group of Glu-166, from the crystal structures) and two cationic residues (most probably Lys-73 and Lys-234). A comparison of these results with the pH-dependence of reactivity of the native RTEM-2 beta-lactamase suggests that the active form of the latter enzyme is also monocationic, although the nucleophile (Ser-70) is likely to be neutral in this case and the carboxylic acid dissociated. A mechanism of class A beta-lactamase catalysis is discussed where the Glu-166 carboxylate acts as a general base/acid catalyst and Lys-73 is principally required for electrostatic stabilization of the anionic tetrahedral intermediate.

Boric acid has been used for over 20 years to preserve urine while in transit for bacteriological examination. It has been suggested that it may be toxic for some urinary pathogens. To investigate this several strains of bacteria and fungi commonly found in urine were exposed to different concentrations of boric acid in nutrient broth. Viable counts were made at the outset and at intervals for up to 24 hours at room temperature to detect bacteriostatic or bactericidal effects. At concentrations between 10 and 20 g/l boric acid was bacteriostatic or fungistatic for very nearly all the common urinary pathogens. At 10 g/l boric acid was weakly bactericidal for some strains of Acinetobacter calcoaceticus and Pseudomonas aeruginosa, though higher concentrations were bacteriostatic only. Group B streptococci varied in their response to boric acid, but for most of them 10 or 20 g/l was satisfactorily bacteriostatic. It is concluded that boric acid is rarely toxic, and when it is, the effect is usually sufficiently delayed to be of only theoretical importance.

Comparative study of the microbicidal activity of some traditional (hydrogen peroxide, boric acid, nitrofurazone) and currently available (Baliz-2, dioxidine, chlorhexidine bigluconate, pervomur) antiseptics against the most commonly encountered causative agents of purulent surgical infection showed 0.8%, 1.2%, and 2.4% pervomur solutions to possess the highest bactericidal and sporicidal activity. This circumstance allowed weak (0.8 and 1.2%) solutions of pervomur to be used in the clinic in 68 patients for the management of purulent postoperative complications and localized purulent infection, which improved the results of treatment significantly.

The antifungal effects of two commercially available spermicidal gels (Conceptrol, produced by Ortho Pharmaceutical, Raritan, N.J., and Koromex, produced by Schmid Laboratories, Little Falls, N.J.) as well as pure nonoxynol-9 and boric acid (both components of vaginal contraceptive products) were tested against 50 clinical yeast isolates by the agar dilution method. The formulated products exerted comparable dose-dependent inhibitory effects against all yeasts tested. A 3-fold dilution of the formulated spermicidal products inhibited 90% of the yeast strains tested. To determine if the antifungal effect was due to the spermicidal detergent nonoxynol-9, this compound was tested for antifungal activity but was completely ineffective against Candida albicans in concentrations up to 10%. Boric acid, present in at least one of the products (Koromex), inhibited representative yeasts at a concentration of 0.4%. The relationship of pH and oxygen tension to inhibition by the commercial spermicides was also investigated. The pH values tested ranged from 4 to 7 and had little effect on inhibition; anaerobiosis at pH 7 slightly reduced the inhibitory activity of Conceptrol gel.

A preservation technique for urine specimens before determination of stone risk factors was evaluated. The purpose of these experiments was to prove the effectiveness of the preservatives used to prevent changes in the concentrations of those constituents measured. Measured concentrations in fresh specimens were compared with those in the same specimens after storage with the preservatives. Refrigeration at 4 degrees C up to five days was appropriate in a laboratory setting, as no significant changes in urinary concentrations occurred. Refrigeration, however, did not offer a convenient method for shipping. Chemical preservation was found to be an effective alternative to refrigeration. Thymol prevented changes in concentration of pH, citrate, uric acid, sulfate, sodium, potassium, and cyclic AMP, while a mixture of hydrochloric (HCl) acid and boric acid prevented changes in calcium, magnesium, phosphorus, oxalate, ammonium, and creatinine. Thus, the addition of thymol or HCl/boric acid to urine specimens will prevent significant changes in the concentrations of stone risk factors.

The results of bacterilogical investigations of urine specimens which contain chemotherapeutics or other germ-inhibiting substances are to be used only with limitation. In order to avoid malinterpretations of microbiological findings by unknown natibacterial autoactivity of the investigation material the routine proof of germ-inhibiting substances in the urine by means of a simple agar diffusion test has proved. By preservation of boric acid which is to be recommended for a longer transport of urine specimens which are to be investigated bacteriologically the results of the inhibitor tests is not falsified.

This study was designed to assess the microbiological risk associated with using unpreserved saline buffered with either borate or phosphate salts. The results indicate that borate buffer has measurable antimicrobial activity and can control some microbiological contamination. However, phosphate-buffered saline can become easily contaminated and usually promotes growth or maintains viability of adventitious contaminants.

Two boric acid tolerant variants were developed by passage in boric acid containing media from a mouse virulent parent Vibrio cholerae strain. The variants were stable, exhibited increased acid resistance, were less virulent to mice, but protected against challenge with the mouse virulent parent strain.

Two strains of boric acid tolerant Vibrio cholerae have been studied in order to identify the characteristics which distinguish them from the 'wild-type' virulent strains. Strain Ib5 requires either amino acid cysteine or methionine while strain Ib5S requires deoxyribonucleic acid (DNA) for growth. Although the strains did not grow on desoxycholate citrate agar (DCA) they grew well on chocolate agar. Morphologically filamentous, bacillary and comma-shaped forms were seen, depending on the media and incubation period. The strains failed to cause accumulation of fluid in gut ligation and permeability factor tests. With the single radial immunodiffusion test, strain Ib5S gave positive reaction in 83% of the tests when DNA was added to the growth medium. On the other hand only 25% of the tests were positive when no DNA was added to the growth medium, even though the antigen was concentrated ten-fold. Strain Ib5 only gave 50% positive tests when the antigen was concentrated ten-fold. It is therefore suggested that Ib5S strain is a cholerangenoid producer in the presence of DNA, and may be useful as an effective vaccine against cholera.

A controlled chemotherapy trial of trachoma was carried out in a Tunisian oasis among schoolchildren with active disease. We compared 1% tetracycline ointment (79 patients) or 1% rifampicin ointment (76 patients) with 5% boric acid ointment (79 patients). Medications were administered twice daily, six days a week, for ten weeks. Slit-lamp examinations by three ophthalmologists were made independently before treatment as well as five, 19, and 39 weeks after treatment. Bacteriologic cultures were taken during treatment as were smears to detect trachoma agent at each clinical examination. Five weeks after treatment, the intensity of conjunctival disease in the tetracycline and rifampicin groups was reduced significantly when compared with boric acid, but at 19 weeks this suppression was found only in the tetracycline group. Ocular bacterial pathogens were eliminated almost entirely in the two antibiotic groups during treatment. The initial prevalence of trachoma (29to 31%) was significantly reduced in the two antibiotic-treated groups at five weeks and 19 weeks after treatment. The prevalence of trachoma was equally low (7%) in all three groups following retreatment with tetracycline. Although both antibiotics were effective, rifampicin offered no advantage over tetracycline in this trial. Recurrent disease in this school-based treatment study probably was due to reinfection from younger siblings at home. While systematic, community-wide, antibiotic treatment programs are not always possible in countries where trachoma is endemic, limited antibiotic therapy programs should be continued in these areas to reduce the intensity and prevalence of trachoma, even though the disease cannot be eradicated.

10 mul of a 2% boric acid solution are injected in chick embryos at 28 hours of incubation. The nervous system is always affected in its anterior and middle region, with exencephaly and reduction in size of the neural tube. Microphtalmy is frequent. The posterior limbs can be likewise altered, leading sometimes to symelia. The histological study shows furthermore that the notochord is locally hypertrophic or missing, at the same level where the nervous system is altered.