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PubMed2004

Separation of benzene, toluene, ethylbenzene, and xylenes by micellar electrokinetic capillary chromatography.

The use of sodium dodecyl sulfate, urea, beta-cyclodextrin, and methanol as additives to the electrophoretic medium containing a Na2HPO4-boric acid buffer in the micellar electrokinetic capillary chromatography of benzene, toluene, ethylbenzene, and three isomers of xylene (collectively known as BTEX) was investigated. The results showed that with the addition of sodium dodecyl sulfate only, higher selectivity and sensitivity and shorter migration time could be achieved, which consequently resulted in better separation of BTEX studied. For this buffer system, good linearity (R2>0.99) was found over the range of 5 to 500 microg ml(-1) for individual BTEX compound and separation time of less than 5 min for BTEX was possible.

Benzene↗

PubMed2005

Quantitative colorimetric measurement of residual antimicrobials in the urine of patients with suspected urinary tract infection.

A simple microtitre plate assay is used to detect antimicrobial activity in clinical urine specimens and its potential as a screening tool is assessed. The assay is based on a colorimetric substrate, p-nitrophenyl-beta-D-glucopyranoside, in combination with a Bacillus subtilis strain to detect antimicrobial residues. The assay identified antimicrobial activity in 31% of the 527 clinical urine samples tested. The majority of the samples (65%) came from the community, with the rest comprising hospital inpatients (19%) and out-patients (16%). The results demonstrated that there is an association between gender and the presence of inhibitory substances, as 40% of males and 27% of females tested positive. Just over two-fifths of hospital patients (46%) tested positive for inhibitory substances, compared to 26% of samples from community patients. Of the 306 samples that were culture-negative (<10(4) bacteria/mL), 42% were positive for inhibitory substances, compared with 17% among the remaining 221 samples. However, there was no evidence of an association between age and the presence of inhibitory substances. This study demonstrates that the bacteriostatic effect of the bacterial preservative boric acid is sufficient to upset the specificity of the assay. Furthermore, it has been suggested that antimicrobial activity can confuse the interpretation of culture results, as they have been found to play a major role in the occurrence of apparently sterile pyuria.

Adolescent↗

PubMed2003

Vulvovaginal trichosporonosis.

OBJECTIVE: Isolation of Trichosporon species from vaginal secretions is a rare event, and no data are available on its pathogenic role. A case series is presented to determine the pathogenic role of Trichosporon species in vulvovaginal infections. METHODS: We performed a retrospective chart review of patients seen in the W.S.U. Vaginitis Clinic in order to identify patients from whom Trichosporon species were isolated. RESULTS: Between 1986 and 2001, a total of 13 patients had a total of 18 positive vaginal cultures for Trichosporon species. All 18 vaginal isolates were T. inkin. In general, positive vaginal cultures were accompanied by low yeast colony counts. Four out of 18 positive T. inkin cultures were obtained from visits by asymptomatic patients. Of the remaining 14 positive T. inkin cultures from patients with symptoms, nine out of 14 cultures had other diagnoses (Candida albicans, six cases; bacterial vaginosis, two cases; Trichomonas, one case). Five positive T. inkin cultures were obtained from visits at which patients had symptoms and no associated diagnosis. In only one of the five episodes could we establish a clear pathogenic role for Trichosporon. In this case the patient was treated with boric acid and had resolution of symptoms and a negative culture at follow-up. In-vitro susceptibility tests revealed that T. inkin was resistant to flucytosine and susceptible to all topical and oral azoles. CONCLUSIONS: T. inkin is occasionally found in vulvovaginal cultures and is usually a non-pathogen. Transient colonization tended to occur in women, usually of African-American origin, with major perturbations in vaginal flora (bacterial vaginosis and trichomoniasis) and increased pH. Pathogenic consequences of Trichosporon colonization appear to be rare.

Adult↗

PubMed2005

Vaginal Candida parapsilosis: pathogen or bystander?

OBJECTIVE: Candida parapsilosis is an infrequent isolate on vaginal cultures; its role as a vaginal pathogen remains unstudied. This retrospective study of women with positive culture for C. parapsilosis sought to characterize the significance of this finding and its response to antifungal therapy. METHODS: From February 2001 to August 2002, we identified all individuals with positive fungal isolates among a population of women with chronic vulvovaginal symptoms. Charts of women with C. parapsilosis cultures were reviewed with regard to patient demographics, clinical presentation and therapeutic response. Mycological cure, defined as a negative fungal culture at the next office visit, and clinical cure, i.e. symptom resolution, were determined for each subject. RESULTS: A total of 582 women had positive vaginal cultures for 635 isolates, of which 54 (8.5%) were C. parapsilosis. The charts of 51 subjects with C. parapsilosis were available for review and follow-up cultures and clinical information were available for 39 (76.5%). Microscopy was positive in 9 (17.6%). Antifungal treatment resulted in mycological cure in 17/19 patients with fluconazole, 7/7 with butoconazole, 6/6 with boric acid, 1/1 with miconazole and occurred spontaneously in 6/7: 24/37 (64.9%) patients with a mycological cure experienced clinical cure. CONCLUSIONS: Although C. parapsilosis is often a cause of vaginal symptoms, it seems to respond to a variety of antifungal agents and may even be a transient vaginal colonizer.

Adult↗

PubMed2003

Irreversible inhibition of jack bean urease by pyrocatechol.

Pyrocatechol was studied as an inhibitor of jack bean urease in 20 mM phosphate buffer, pH 7.0, 25 degrees C. The inhibition was monitored by an incubation procedure in the absence of substrate and reaction progress studies in the presence of substrate. It was found that pyrocatechol acted as a time- and concentration dependent irreversible inactivator of urease. The dependence of the residual activity of urease on the incubation time showed that the rate of inhibition increased with time until there was total loss of enzyme activity. The inactivation process followed a non-pseudo-first order reaction. The obtained reaction progress curves were found to be time-dependent. The plots showed that the rate of the enzyme reaction in the final stages reached zero. From protection experiments it appeared that thiol-compounds such as L-cysteine, 2-mercaptoethanol and dithiothreitol prevented urease from pyrocatechol inactivation as well as the substrate, urea, and the competitive inhibitor boric acid. These results proved that the urease active site was involved in the pyrocatechol inactivation.

Catechols↗

PubMed1975

Scanning microscopy of dissociated tissue cells.

A method is described for studying by scanning electron microscopy (SEM) all the surfaces of fully differentiated cells from intact tissues. Thus, cell faces normally hidden from view are exposed and made available for SEM examination. This is achieved by fixing the tissue in OSO4 and then soaking it in a 1% solution (in water) of boric acid. After different periods of time, varied according to particular tissue, slight mechanical pressure will cause the fixed tissue to dissociate into its component cells. These are then made to adhere to a substrate and are taken through critical point drying, etc., for examination. Observations are reported on the topography of whole hepatocytes, adsorptive cells of the intestinal epithelium, proximal tubule cells of the rat kidney, mammary tumor cells of the mouse, and rat sarcoma cells. Several other tissues are reported to dissociate when similarly treated, but for each the procedure must be slightly modified.

Animals↗

PubMed2002

Vaginitis due to Candida krusei: epidemiology, clinical aspects, and therapy.

Twelve women with vaginal Candida krusei infection were evaluated. In vitro antifungal susceptibility testing and molecular typing were performed. Patients infected with C. krusei frequently had refractory vulvovaginal signs and symptoms that were otherwise indistinguishable from vaginitis due to other yeasts. Patients were 32-63 years old and had previously received multiple courses of antimycotic agents, including fluconazole and miconazole. The most active azole in vitro was clotrimazole, with a 90% minimum inhibitory concentration of 0.25 microg/mL. Four of 6 patients treated with boric acid had clinical and mycological cure. Two dominant genotypes of C. krusei were identified via contour-clamped homogenous electrical field analysis. No major genotypic change was observed in successive isolates from the same patient in most cases, suggesting that these refractory cases were relapses. C. krusei is a rare but important cause of refractory vaginitis and is unique because of its intrinsic resistance to fluconazole.

Adult↗

PubMed1989

Detection by 32P-postlabeling of thymidine glycol in gamma-irradiated DNA.

The 32P-postlabeling method has been adapted for the analysis of thymidine-cis-glycol-3'-phosphate (cis-dTGp,cis-5,6-dihydroxy-5,6-dihydrothymidine-3'-phosphat e). Cis-dTGp was isolated and purified from normal nucleotides by phenylboronate affinity chromatography and phosphorylated by T4 polynucleotide kinase in presence of 1 mM BeCl2 at pH 7.5. These modifications of the postlabeling method resulted in a 5'-phosphorylation of dTGp with a labeling efficiency of up to 20% whereas the natural nucleotides were almost completely dephosphorylated at the 3' position under these conditions. The reaction products, containing radio-labeled thymidine-cis-glycol-3',5'-bis-[5'-32P]phosphate (cis-*pdTGp), were separated by two-dimensional anion-exchange TLC on polyethyleneimine cellulose sheets. Boric acid was added in the second dimension in order to selectively retard cis-glycols. The method was applied to gamma-irradiated nucleotides and calf thymus DNA. In the nucleotide mixture, 330-99,000 thymine glycol (TG) moieties were detected per 10(6) thymines (T) in a dose range of 14-1000 Gy respectively. In DNA, these values ranged from 400 to 2700 TG/10(6) T. The data are in good agreement with methods using radiochemical and immunological techniques. Non-irradiated DNA showed a background level of 10TG/10(6) T. This practical limit of detection was higher than can be achieved with the postlabeling technique, indicating that the present method might be a sensitive alternative for a determination of oxidative DNA damage.

Cations, Divalent↗

PubMed2003

Determination of trace RA by capillary electrophoresis-solid-phase microextraction with direct UV detection.

A new method of offline solid-phase microextraction coupled with capillary electrophoresis (CE) [in an uncoated capillary using borax and boric acid in acetonitrile-water (40:60) as the running buffer] with UV detection at 254 nm is presented and used for direct determination of trace biomedically important retinoic acid (RA) without any derivation. As low as 138 ng/mL RA in aqueous solution can be determined using CE with UV detection with a concentration factor of 19.6 times.

Electrophoresis, Capillary↗

PubMedDate not supplied

Determination of hydroxocobalamin and cyanocobalamin by derivative spectrophotometry in cyanide poisoning.

Hydroxocobalamin (OHCo) and cyanocobalamin (CNCo) are determined directly in biological media, without extraction, by using first derivative spectrophotometry. We diluted 200 mL of plasma, urine, or standards with 1.8 mL of pH 6 buffer (boric acid, potassium dihydrogen orthophosphate, and potassium hydroxide). The first derivative spectra of the dilutions were plotted between 320 and 400 nm. At the exact zero-crossing point for hydroxocobalamin, the derivative values of cyanocobalamin concentration were determined. The same procedure was followed for hydroxocobalamin at the zero-crossing point for cyanocobalamin. The derivative values of the concentration curves are linear in the range 5-100 microM. The minimum detection limit is approximately 5 microM for hydroxocobalamin of cyanocobalamin on the determination of hydroxocobalamin or vice versa, although the spectra strongly overlap. The method is fast and simple to use, thus making it easy to assess the in vivo transformation of hydroxocobalamin into cyanocobalamin after the administration of high doses of hydrocobalamin in cyanide poisoning.

Cyanides↗

PubMed1999

Boron stimulates yeast (Saccharomyces cerevisiae) growth.

Boron is required for the growth of vascular plants and embryonic development in fish. The molecular basis of boron's essentiality, however, remains unknown for both. The objective of this study was to determine whether yeast (Saccharomyces cerevisiae) could be used as a model for the evaluation of intracellular boron trafficking. Three experiments were conducted to assess the effect of boron supplementation on yeast growth. Cultures were grown in low boron media containing 0.04 micromol B/L. After 24 h, a new flask was inoculated with this culture; it was allowed to reach early log phase growth (9 h) and was then divided between two flasks. One flask was supplemented with ultrapure boric acid to achieve a concentration of 185 micromol B/L (+B); the other was supplemented with an equivalent volume of ultrapure water (NB). Boron significantly stimulated cell growth rate into the stationary phase of growth. Yeast cell boron concentrations decreased in both treatments over the course of the experiment, but analysis by inductively coupled plasma-mass spectrometry (ICPMS) did not detect differences in cellular concentration between the boron supplemented (B) and nonsupplemented (NB) groups. Ethanol concentrations did not differ between the two treatments, demonstrating that boron-stimulated growth was not a secondary effect of alcohol dehydrogenase inhibition. The demonstration of boron-dependent growth stimulation in yeast suggests that Saccharomyces cerevisiae can be used as a model system for the study of intracellular boron trafficking.

Boron↗

PubMed2003

Common complementary and alternative therapies for yeast vaginitis and bacterial vaginosis: a systematic review.

UNLABELLED: This article is a systematic review of the literature regarding the most commonly used complementary and alternative medicine (CAM) therapies for yeast vaginitis and bacterial vaginosis. A search was conducted of all published literature on conventional search engines (PubMed, EMBASE, the Cochrane Registry, CINAHL, LILACS) and alternative medicine databases (Natural Medicines Comprehensive Database, Longwood Herbal Taskforce, and Alternative Medicine Alert), for all studies of the five most commonly used CAM treatments of vaginitis. Inconsistencies in definition of vaginitis, type of intervention, control groups, and outcomes prevented performance of a meta-analysis, and paucity of high-quality studies made ranking by evidence-based scales unsuitable. Lactobacillus recolonization (via yogurt or capsules) shows promise for the treatment of both yeast vaginitis and bacterial vaginosis with little potential for harm. Boric acid can be recommended to women with recurrent vulvovaginal Candidal infections who are resistant to conventional therapies, but can occasionally cause vaginal burning. Because of associated risks in the absence of well-documented clinical benefits, douching remains a practice that should not be recommended for the treatment of vaginitis. Finally, tea tree oil and garlic show some in vitro potential for the treatment of vaginitis, but the lack of in vivo studies preclude their recommendation to patients for the time-being. The available evidence for CAM treatments of vaginitis is of poor quality despite the prevalent use of these therapies. Well-designed randomized, controlled trials investigating the efficacy and safety of these therapies for vaginitis are needed before any reliable clinical recommendations can be made. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to list the most common complementary and alternative medicine therapies for vaginitis, summarize the data surrounding the efficacy of each therapy, describe the adverse affects of each therapy, and outline which therapies are recommended and not recommended for vaginitis.

Anti-Infective Agents, Local↗

PubMed2000

Phenotypic characterisation of Candida albicans isolated from chronic hyperplastic candidosis.

The phenotypes of 35 Candida albicans isolates from 19 patients with chronic hyperplastic candidosis (CHC) and 35 isolates from 30 patients with non-CHC infections were compared. Typing was based on carbohydrate assimilation, chemical sensitivity and serology. Eight carbohydrate assimilation profiles were evident with the API-20C system and a single profile predominated for isolates from CHC (17 of 19 patients; 89%) and non-CHC (18 of 30 patients; 63%). Chemical sensitivity tests revealed four profiles with no significant difference between CHC and non-CHC isolates. Serotype A predominated for isolates from both CHC (15 of 19 patients; 79%) and non-CHC (25 of 30 patients; 83%) infections. Boric acid resistance was more prevalent in CHC isolates, although a significant difference was not apparent. In summary, there was no overall difference in the phenotypes of isolates from CHC and non-CHC patients, and clonal restriction of CHC isolates was not demonstrated.

Candida albicans↗

PubMed2001

Formation of rhamnogalacturonan II-borate dimer in pectin determines cell wall thickness of pumpkin tissue.

Boron (B) deficiency results in inhibition of pumpkin (Cucurbia moschata Duchesne) growth that is accompanied by swelling of the cell walls. Monomeric rhamnogalacturonan II (mRG-II) accounted for 80% to 90% of the total RG-II in B-deficient walls, whereas the borate ester cross-linked RG-II dimer (dRG-II-B) accounted for more than 80% of the RG-II in control plants. The results of glycosyl residue and glycosyl linkage composition analyses of the RG-II from control and B-deficient plants were similar. Thus, B deficiency does not alter the primary structure of RG-II. The addition of (10)B-enriched boric acid to B-deficient plants resulted within 5 h in the conversion of mRG-II to dRG-II-(10)B. The wall thickness of the (10)B-treated plants and control plants was similar. The formation and possible functions of a borate ester cross-linked RG-II in the cell walls are discussed.

Borates↗

PubMed1967

Experimental microbiology of saturated salt solutions and other harsh environments. 3. Growth of salt-tolerant penicillium notatum in boron-rich media.

A stress-tolerant strain of Penicillium notatum, isolated by passage through a nutrient solution saturated with calcium acetate, was found to have a tolerance to boron in several states of oxidation. Growth in the presence of elementary boron, saturating amounts of boric acid, and with various concentrations of sodium borohydride was observed and mycelial mats were spectrographically analyzed for boron accumulation.

Boron↗

PubMed1981

Distribution of Foliar-applied Boron Measured by Spark-source Mass Spectrometry and Laser-probe Mass Spectrography.

The distribution of foliar-applied boron ([(10)B]boric acid) in radish (Raphanus sativus L.) was studied using for analysis of the stable isotopes a technique allowing a high sensitivity: spark-source mass spectrometry. Boron was recovered in the nontreated aerial parts and in the roots; however, the greatest fraction was in the treated leaf. It was possible with a laser-probe mass spectrograph to show that boron was not superficially located in the treated area but was present in tissues at all levels of depth considered.

Journal Article↗

PubMed2006

Structure of Bacillus halmapalus alpha-amylase crystallized with and without the substrate analogue acarbose and maltose.

Recombinant Bacillus halmapalus alpha-amylase (BHA) was studied in two different crystal forms. The first crystal form was obtained by crystallization of BHA at room temperature in the presence of acarbose and maltose; data were collected at cryogenic temperature to a resolution of 1.9 A. It was found that the crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 47.0, b = 73.5, c = 151.1 A. A maltose molecule was observed and found to bind to BHA and previous reports of the binding of a nonasaccharide were confirmed. The second crystal form was obtained by pH-induced crystallization of BHA in a MES-HEPES-boric acid buffer (MHB buffer) at 303 K; the solubility of BHA in MHB has a retrograde temperature dependency and crystallization of BHA was only possible by raising the temperature to at least 298 K. Data were collected at cryogenic temperature to a resolution of 2.0 A. The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 38.6, b = 59.0, c = 209.8 A. The structure was solved using molecular replacement. The maltose-binding site is described and the two structures are compared. No significant changes were seen in the structure upon binding of the substrates.

Acarbose↗

PubMed1989

Infection ability of watermolds in some temperate fishes of Himalaya, India.

Infection ability tests of four species of the Saprolegniales viz., Brevilegnia subclavata Couch, Geolegnia inflata Coker & Braxton, Protoachlya oryzae Khulbe and Scoliolegnia centrica Khulbe were made by artificial inoculation experiments. Except Geolegnia inflata, all the three species parasitized the test fishes (Carassius auratus L., Puntius conchonius Ham., P. ticto Ham. and Nemacheilus rupicola). Two chemicals, namely boric acid and potassium permanganate were effective at 0.1 to 0.15 M concentrations against parasitic watermolds.

Animals↗