SEARCH · PubMed Health

Results for “BORIC ACID”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources

PubMed2004

Phenolic extraction of DNA from mammalian tissues and conversion to deoxyribonucleoside-5'-monophosphates devoid of ribonucleotides.

Towards a goal of detecting scaled-up DNA adducts as altered deoxynucleotides by mass spectrometry, we have set up a practical and general method for isolating DNA-derived deoxyribonucleoside-5'-monophosphates devoid of ribonucleotides starting with a 1 g sample of mammalian tissue. The method is practical because costs have been minimized, and it is general because it can be applied to a more difficult sample such as mouse skin or non-fresh calf liver. The procedure, consisting of a series of steps that were largely gleaned and tuned from prior literature, proceeds as follows: (1) homogenize the tissue in sodium dodecyl sulfate; (2) digest with ribonuclease A, ribonuclease TI, alpha-amylase and proteinase K; (3) partition between water and phenol; (4) precipitate the DNA with ethanol followed by redissolving and dialysis; and (5) digest with nuclease P1 and phosphodiesterase I followed by ultrafiltration and boric acid gel chromatography. The yellow to brown color of DNA from difficult tissues only persisted up to the ultrafiltration step. Apparently this DNA was contaminated with iron-containing proteins. Residual ribonucleotides were not observable (<0.1%) by HPLC in the final sample. Without boric acid gel chromatography, residual contamination by ribonucleotides was about 1% even when the DNA was purified before digestion by phenol partitioning followed by use of a Genomic Tip kit from Qiagen.

Animals↗

PubMed1990

[Recent development of determination methods for adrenocortical hormones and catecholamines].

Newly developed resins and high-performance liquid chromatography (HPLC) with column switching technique have enabled on-line solid-phase extraction, purification and derivatization for highly sensitive determination in recently developed determination methods for serum cortisol, urinary 17-ketosteroids (17-KS), urinary conjugated 17-KS fractions and urinary free catecholamines (CA). These methods are (1) determination of serum cortisol by HPLC with a BSA-ODS column (TSK) and serum sample direct injection, (2) determination of fluorescently derivatized serum cortisol with sulfuric acid and ethanol by column switching HPLC, (3) determination of urinary 17-KS with no need of previous hydrolysis of the conjugated forms, (4) HPLC of conjugated 17-KS fluorescently prelabelled with dansyl hydrazine, (5) HPLC of urinary free catecholamines (CA) with on-line extraction using a cation exchange column and on-line fluorescent derivatization with 1,2-diphenylethylenediamine, (6) ion pair HPLC of urinary free CA with on-line extraction using a hard boric acid gel column and postcolumn trihydroxyindole derivatization, and (7) HPLC of urinary free CA with on-line extraction and solid-phase derivatization using a boric acid gel column, o-phthalaldehyde and 2-mercaptoethanol, have achieved no previous or simple sample extraction, more rapid, accurate and higher sensitive determination comparison with ordinary methods for these substances and furthermore, some methods have enabled fully automated analysis.

17-Ketosteroids↗

PubMed1991

High pressure liquid chromatographic identification of hyaluronic acid and chondroitin sulphate disaccharides.

In this report we describe a system capable of resolving all of the known unsaturated disaccharides derived from the chondroitin sulphates, dermatan sulphate and hyaluronic acid by chondroitinase digestion. This system is superior to others in that the non-sulphated and mono-, di- and tri-sulphated disaccharides can be separated with good resolution in approximately 40 min in an isocratic solvent. The system employs an amino-cyano silica gel column (Whatman Partisil 5 PAC, 25 cm) and is eluted with an isocratic solvent consisting of 48% (v/v) acetonitrile, 14% (v/v) methanol and 38% (v/v) aqueous buffer. This aqueous buffer contains 0.5 M Tris-HCl, 0.1 M boric acid, 23.4 mM sulphuric acid, pH 8.0. UV absorption is monitored at 229 nm and for most disaccharides as little as 150 ng can be reliably determined. The addition of boric acid to the eluent is essential for good resolution of all components and the addition of low concentrations of sulphuric acid is used to control the elution times of various components. The system was applied to the analysis of glycosaminoglycan standards and excellent agreement with previous compositional analyses was obtained.

Animals↗

PubMed1988

Further studies of swarmer cell differentiation of Proteus mirabilis PM23: a requirement for iron and zinc.

Proteus mirabilis PM23, unlike other motile strains of the species, differentiates in rich fluid media to form nonseptate filaments resembling the swarmer cells formed on solid media. The swarming activity of PM23 is greater than that of the other strains on solid media and it grows faster than another strain, IM47, in differentiation-supporting broth. This faster growth is not exhibited in broth that does not support differentiation. The differentiation of PM23 in brain-heart infusion broth occurs over a wide range of pH and temperature. Inhibitors of swarming on agar plates (p-nitrophenylglycerol and boric acid) and three chelating agents (EDTA, sodium cyanide, and sodium diethyldithiocarbamate) stop differentiation both on plates and in brain-heart infusion broth; however, EGTA is not effective even at 10 mM (10 times the minimum inhibitory concentration of EDTA). The inhibitory mechanisms of p-nitrophenylglycerol and boric acid are different from that of the chelating agents. The timing of EDTA inhibition suggests generation of a "signal" to differentiate after about 2 h growth. Prevention of differentiation by addition of Fe2+ and Zn2+ up to near the time that differentiation should appear suggests that these cations have a crucial involvement in the process of initiation. However, they are not effective as additives in allowing differentiation to occur in defined media or even nutrient broth; the further addition of nucleotides or cAMP was equally ineffective.

Chelating Agents↗

PubMed1996

Rhamnogalacturonan-II, a pectic polysaccharide in the walls of growing plant cell, forms a dimer that is covalently cross-linked by a borate ester. In vitro conditions for the formation and hydrolysis of the dimer.

Rhamnogalacturonan II (RG-II) is a structurally complex pectic polysaccharide present in the walls of growing plant cells. We now report that RG-II, released by endopolygalacturonase treatment of the walls of suspension-cultured sycamore cells and etiolated pea stems, exists mainly as a dimer that is cross-linked by a borate ester. The borate ester is completely hydrolyzed at room temperature within 30 min at pH 1, partially hydrolyzed between pH 2 and 4, and stable above pH 4. The dimer is formed in vitro between pH 2.4 and 6. 2 by treating monomeric RG-II (0.5 mM) with boric acid (1.2 mM); the dimer formed after 24 h at pH 3.4 and 5.0 accounts for approximately 30 and approximately 5%, respectively, of the RG-II. In contrast, the dimer accounts for approximately 80 and approximately 54% of the RG-II when the monomer is treated for 24 h at pH 3.4 and 5.0, respectively, with boric acid and 0.5 m Sr2+, Pb2+, or Ba2+. The amount of dimer formed at pH 3.4 or 5.0 is not increased by addition of 0.5 mM Ca2+, Cd2+, Cu2+, Mg2+, Ni2+, and Zn2+. Steric considerations appear to regulate dimer formation since those divalent cations that enhance dimer formation have an ionic radius >1.1 A. Our data suggest that the borate ester is located on C-2 and C-3 of two of the four 3'-linked apiosyl residues of dimeric RG-II. Our results, taken together with the results of two previous studies (Kobayashi, M., Matoh, T., and Azuma, J.-I. (1996) Plant Physiol. 110, 1017-1020; Ishii, T., and Matsunaga, T. (1996) Carbohydr. Res. 284, 1-9) provide substantial evidence that this plant cell wall pectic polysaccharide is covalently cross-linked.

Barium↗

PubMed1998

Boron stimulates embryonic trout growth.

Boron is present in our soil, water and air. Cyanobacteria require it for nitrogen fixation, and vascular plants require it for the formation of cell walls and membranes. I report here how boron affects the growth of embryonic rainbow trout (Oncorhynchus mykiss). Fertilized ovum from the Mt. Whitney rainbow trout strain were incubated at (12.5 degreesC) in Type 1 ASTM ultrapure grade water supplemented with boric acid (99.5% purity) during the 1995 and 1997 spawning seasons. Boron concentrations of the incubation solutions were determined by direct measurement using the curcumin procedure or inductively coupled plasma-mass spectrometry. In the 1995 study boron ranged from 1 to 936 micromol/L. Ca, Na and Mg salts were included in the incubation solutions to approximate concentrations in natural water. In the 1997 study fertilized eggs were incubated in ultrapure water supplemented with boric acid alone over a range from 2.2 to 90.6 micromol/L. The 1995 study used 144 embryos per B concentration and the 1997 study used 96 embryos per B concentration. Growth and teratogenicity were evaluated at the eye, hatch and 2-wk posthatch developmental stages. Boron stimulated growth in a dose-dependent manner in both studies (P < 0.001), and exposure was associated with an increase in B body concentration (P < 0.05). No teratogenic or microbicidal effects were apparent. These results are consistent with those expected of an element essential for vertebrate development. J. Nutr. 2488-2493, 128: 1998

Animals↗

PubMed2001

The effect of pregnancy on renal clearance of boron in humans: a study based on normal dietary intake of boron.

Boron occurs most frequently in nature as borates and boric acid, never as the free element. Its largest uses are in glass, detergents, and agriculture. Essential for higher plants, there is growing evidence for essentiality in vertebrates. Humans consume daily about a milligram of boron, mostly from fruit and vegetables. At high doses, boron is a developmental and reproductive toxin in animals. Pregnant rats were the most sensitive. An oral NOAEL of 9.6 mg B/kg/day was established for developmental toxicity in Sprague-Dawley rats fed boric acid. To extrapolate from the large, animal boron toxicity database to humans, especially to pregnant women, information on renal clearance of boron was needed. This study's purpose was to measure renal clearance of boron in pregnant and nonpregnant woman. In 16 second trimester women and 15 nonpregnant age-matched referents, dietary boron provided the blood and urine boron concentrations used for calculating boron clearance. The pregnant and nonpregnant boron intake was 1.35 and 1.31 mg boron/24 h, respectively. Blood for boron, creatinine, and urea was collected at the start, at 2 h, and at 24 h. Urine was collected during the first 2 h in the Clinical Research Center and during a 22-h period outside the center for measurement of volume, boron, and creatinine. Renal boron clearance measured over the initial 2 h, the most complete urine collection period, was 68.30ml/min/1.73 m(2) for pregnant subjects and 54.31ml/min/1.73 m(2) for nonpregnant subjects. Comparison of renal boron clearance with creatinine clearance indicated that tubular reabsorption of boron occurred in both pregnant and nonpregnant women.

Adolescent↗

PubMed2004

Boron retranslocation in Scots pine and Norway spruce.

We previously traced 10B-enriched boric acid from shoots to roots to demonstrate the translocation of boron (B) in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings. To gain a more detailed understanding of B translocation, we sought: (1) to demonstrate B retranslocation directly, by showing that foliar-applied 10B is located in the new growth after dormancy; and (2) to assess whether shoot-applied B affects growth in the long term. We applied 10B-enriched boric acid to needles of Scots pine and Norway spruce seedlings. After a dormancy period and 9 weeks of growth, small but significant increases in the 10B isotope were found in the new stem and needles of both species. In Scots pine, the total B concentration of the new stem was also increased. Both species contained polyols, particularly pinitol and inositol. Boron-polyol complexes may provide a mechanism for mobilizing B in these species. To determine the long-term effects of applied B, seedlings were grown for two growing seasons after the application of 10B to shoots. In Norway spruce, the proportion of 10B in the root systems and current needles of the harvest year was slightly higher than in the controls, and in Scots pine root systems, marginally so. The B treatment had no effect on growth of Norway spruce seedlings. In Scots pine seedlings, the B treatment caused a 33% increase in total dry mass and significantly increased the number of side branches.

Boron↗

PubMed1981

The influence of effectors on the refolding (reactivation) of immobilized trypsin.

The refolding of immobilized trypsin in the presence of various effectors of its enzymatic activity has been studied. Trypsin covalently bound to Sephadex G-200 was made to unfold in a concentrated solution of urea; at the same time its S-S bonds were split with the help of dithiothreitol. The preparation was then separated from the splitting agents, and one of the effectors of the enzymatic activity of trypsin (boric acid, benzamidine, pancreatic or soybean inhibitors of trypsin, N-benzoyl-L-arginine ethyl ester, and N-tosyl-L-arginine methyl ester) was added and the reactivation of immobilized enzyme was studied in the absence of catalysts of thiol-disulphide exchange. The following effects were found. 1. The reactivation of immobilized trypsin in the presence of specific substrates or protein inhibitors proceeds with the same yield (2-5%) as in their absence. 2. In the presence of benzamidine or boric acid (competitive inhibitors) the reactivation yields of the immobilized trypsin increased 5-fold and 12-fold respectively, and became equal to 15% and 40%. Comparison of these results with the statistical probability of formation of the six native S-S bonds from twelve SH groups (approximately 0.01%) shows that if trypsin is made to refold in an immobilized state in the presence of a 'good' effector, the yield of the reactivation of the enzyme can be increased several thousand times. 3. Similar effects were observed for trypsin immobilized on Sepharose 4B. A model is suggested in terms of which the influence of various effectors on trypsin refolding is explained as being a result of their ability to bind with an intermediate folded forms of protein followed by a shift of the equilibrium towards 'regular' conformers.

Catalysis↗

PubMed1985

Uropygiols: confirmation of structure by proton magnetic resonance.

Lipids were extracted from excised uropygial glands of domestic chickens and the wax diesters were isolated by preparative thin-layer chromatography (TLC). The diesters were hydrolyzed and the liberated diols were resolved by boric acid TLC into two fractions. These were investigated by proton magnetic resonance at 360 MHz of the free diols and of their acetonide derivatives. The results showed that the cis and trans acetonides, formed from the erythro and threo isomers of the diols, respectively, could be distinguished by the degree of magnetic nonequivalence of the two acetonide methyl groups in each molecule. On the presumption that the cis isomer should show the greater nonequivalence of the methyl groups, this configuration was assigned to the acetonides of these diols which had the lesser TLC mobility on boric acid/silica gel. This agrees with the assignment of configuration made by earlier workers on the basis of the relative TLC mobility of the diol isomers on boric acid/silica gel, but was contrary to a previous assignment based on gas-liquid chromatographic (GLC) retention times. We conclude that the erythro isomers of the diols are characterized by lower mobility on boric acid TLC, as well as on silica gel TLC, and form acetonides that have longer retention times on GLC, and greater nonequivalence of the acetonide methyl groups in the NMR spectrum, than do the acetonides of the threo isomers.

Animals↗

PubMed1992

The use of three ferguson-plot-based calculation methods to determine the molecular mass of proteins as illustrated by molecular mass assessment of rat-plasma carboxylesterases ES-1, ES-2, and ES-14.

The molecular masses of three rat-plasma carboxylesterases (ES-1, ES-2, and ES-14) were estimated by transverse-gradient polyacrylamide gel electrophoresis and subsequent application of Ferguson-plot-based calculation methods. Two electrophoretic buffer systems were used and the data subjected to either weighted or unweighted regression analysis. The Tris-boric acid buffer system produced significantly higher retardation coefficients than the Tris-glycine system. Molecular mass estimates were significantly higher with the Tris-glycine buffer system. Unweighted instead of weighted analysis produced significantly higher molecular mass estimates. Molecular mass estimates also depended on the calculation method, that is, the choice of calibration relationship with molecular size as a function of retardation coefficient. Three commonly used calibration relationships were compared. On the basis of their accuracy, both the weighted log[retardation coefficient] versus log[molecular mass] plot and the square root of retardation coefficient versus molecular radius were found suitable, provided that the Tris-boric acid buffer was used for electrophoresis. Using the former calibration relationship, the molecular masses of rat-plasma ES-1, ES-2, and ES-14 were 55.5, 61.1, and 65.3 kDa, respectively.

Animals↗

PubMed1998

The response of trout and zebrafish embryos to low and high boron concentrations is U-shaped.

Fish in the embryo-larval stage of development have been shown to be sensitive to boron (B) at both ends of the dose-response curve (1,2). The present study evaluated the health effects of low and high B concentrations on rainbow trout (Oncorhynchus mykiss), a cold water species, and zebrafish (Danio rerio), a warm water species. Rainbow trout embryos were incubated from day 1 until 2 wk posthatch in Type 1 ASTM ultrapure-grade water (12.5 degrees C) supplemented with only B (0-500 microM) as boric acid, or together with CaCO3 (0-2 mM) to increase water hardness. Embryonic growth was stimulated by B in a dose-dependent manner at all Ca concentrations (p < 0.001). Chronic exposures below 9 micromol B/L impaired embryonic growth and above 10 mmol B/L caused death (p < 0.001). Thus, the safe range of exposure for the rainbow trout was between the adverse effect concentrations of 9 micromol B/L and 10 mmol B/L. Zebrafish were maintained for 6 mo in ultrapure water containing <0.2 micromol B/L to determine the effect of low-level exposure. High-level exposure was assessed by exposing zygotes, derived from parents maintained at 46 micromol B/L, to graded concentrations of boric acid up to a concentration of 75 mmol B/L from fertilization until they were free feeding (96 h). Fertilization occurred, but zygotes failed to survive when water contained <0.2 micromol B/L (p < 0.001). Death occurred at and above 9.2 mmol B/L. Thus, the safe range of B exposure for zebrafish was between the adverse effect concentrations of 0.2 micromol B/L and 9.2 mmol B/L. The dose-response for both species was thus U-shaped.

Analysis of Variance↗

PubMed1998

Effect of electroporation on cell killing by boron neutron capture therapy using borocaptate sodium (10B-BSH).

The cell membrane permeability of 10B-enriched borocaptate sodium (BSH) and the extent to which BSH is accumulated in cells are controversial. To elucidate these points and to enhance the accumulation of BSH in cells, the effect of electroporation on boron neutron capture therapy (BNCT) using BSH was investigated. The first group of SCCVII tumor cells was incubated in culture medium with 10B-BSH or 10B-enriched boric acid, and exposed to neutrons from the heavy water facility of the Kyoto University Reactor. More than 99% of neutrons were thermal neutrons at flux base. The second group was pretreated with electroporation in combination with 10B-BSH, and thereafter the cells were irradiated with neutrons. The cell-killing effect of BNCT was measured by colony formation assay. The surviving cell fraction decreased exponentially with neutron fluence, and addition of BSH significantly enhanced the cell-killing effect of NCT depending on 10B concentration and the preincubation time of cells in the BSH-containing culture medium. The electroporation of cells with BSH markedly enhanced the BNCT effect in comparison with that obtained with preincubation alone. The effect of BSH-BNCT with electroporation was almost equal to that of BNCT using 10B-boric acid at the same 10B concentration. The effect of BNCT on cells pretreated with BSH and electroporation was not reduced by repeated washing of the cells before neutron irradiation. Decrease of the effect of BSH-BNCT plus electroporation with increase in the waiting time between the electroporation and the neutron irradiation could be explained in terms of the extent of cell growth during that time. These data suggest that BSH penetrates the cells slowly and remains after washing. Electroporation can introduce BSH into the cells very efficiently, and BSH thus introduced stays in the cells and is not lost in spite of the intensive washing of the cells. Therefore, if electroporation is applied to tumors after BSH injection, 10B would remain in the tumors but be cleared from normal tissues, and selective accumulation of 10B in tumors will be achieved after an appropriate waiting time.

Animals↗

PubMed2006

Impact of urine preservation methods and duration of storage on measured levels of environmental contaminants.

Collection of urine samples in human studies involves choices regarding shipping, sample preservation, and storage that may ultimately influence future analysis. As more studies collect and archive urine samples to evaluate environmental exposures in the future, we were interested in assessing the impact of urine preservative, storage temperature, and time since collection on nonpersistent contaminants in urine samples. In spiked urine samples stored in three types of urine vacutainers (no preservative, boric acid, and chlorhexidine), we measured five groups of contaminants to assess the levels of these analytes at five time points (0, 24, 48, and 72 h, and 1 week) and at two temperatures (room temperature and 4 degrees C). The target chemicals were bisphenol A (BPA), metabolites of organophosphate (OP), carbamate, and pyrethroid insecticides, chlorinated phenols, and phthalate monoesters, and were measured using five different mass spectrometry-based methods. Three samples were analyzed at each time point, with the exception of BPA. Repeated measures analysis of variance was used to evaluate effects of storage time, temperature, and preservative. Stability was summarized with percent change in mean concentration from time 0. In general, most analytes were stable under all conditions with changes in mean concentration over time, temperature, and preservative being generally less than 20%, with the exception of the OP metabolites in the presence of boric acid. The effect of storage temperature was less important than time since collection. The precision of the laboratory measurements was high allowing us to observe small differences, which may not be important when categorizing individuals into broader exposure groups.

Environmental Exposure↗

PubMed2006

Fire resistance of Douglas fir (Pseudotsuga menzieesi) treated with borates and natural extractives.

The objective of this study was to determine fire resistance of Douglas fir (Pseudotsuga menzieesi (Mirb.) Franco) specimens treated with borate supplemented aqueous solutions of brutia pine bark powder, acorn powder, sumach leaf powder, and gall-nut powder. Boric acid (BA) and borax (BX) were used as borates which are the most commonly used fire retardants in wood preservation industry. Natural extractives (brutia pine bark powder, sumach leaf powder, acorn powder, and gall-nut powder) were also used which have toxic efficiency against insects and fungi due to their tannin contents. A commercial treatment compound Tanalith-CBC (copper-borate-chromate), which is an impregnation chemical, is used for comparison. The fire test method was performed in three stages: flame stage, without flame stage, and glowing stage. Results indicated that the lowest temperature for flame stage, without flame stage, and glowing stage were obtained for specimens treated with BA and BX mixture (7:3; weight:weight). The lowest mass loss was found for the specimens treated with a mixture of BA and BX. Natural extractives did not improve fire resistance of the samples. However, boric acid and borax had excellent fire retardant effectiveness over untreated and treated samples with natural extractives.

Borates↗

PubMed1998

Electroporation increases the effect of borocaptate (10B-BSH) in neutron capture therapy.

PURPOSE: The cell membrane permeability of borocaptate (10B-BSH) and its extent of accumulation in cells are controversial. This study was performed to elucidate these points. METHODS AND MATERIALS: Two different treatments were applied to SCCVII tumor cells. The first group of tumor cells was incubated in culture medium with 10B-BSH or 10B-enriched boric acid, and was exposed to neutrons from the heavy water facility of the Kyoto University Reactor (KUR). More than 99% of neutrons were thermal neutrons at flux base. The second group was pretreated by electroporation in combination with 10B-BSH, and thereafter the cells were irradiated with neutrons. The cell killing effects of boron neutron capture therapy (BNCT) using BSH were investigated by colony formation assay. RESULTS: Surviving cell fraction decreased exponentially with neutron fluence, and addition of BSH significantly enhanced the cell killing effect of neutron capture therapy (NCT) depending on 10B concentration. The effect of BSH-BNCT also increased with preincubation time of cells in the medium containing BSH. The electroporation of cells with BSH at 10 ppm 10B markedly enhanced BSH-BNCT effects in comparison with that of preincubation alone. The effect of BSH-BNCT with electroporation was equal to that of BNCT using 10B-boric acid at a same 10B concentration (10 ppm). CONCLUSIONS: BSH is suggested to penetrate the cells slowly and remained after washing. Electroporation can introduce BSH into the cells very efficiently, and BSH stays in the cells and is not lost by washing. Therefore, if electroporation is applied to tumors after BSH injection, 10B remains in tumors but is cleared from normal tissues, and selective accumulation of 10B in tumors will be achieved after an adequate waiting time.

Borohydrides↗

PubMed1988

Basal lamina fenestrations in the human colon: transmission and scanning electron microscope study.

Basal lamina at the interface between colonic epithelial cells and the lamina propria was exposed by incubating colonic specimens in 1% boric acid solutions. Examination of this epithelial-stromal interface by scanning electron microscopy (SEM) showed a smooth, slightly undulating basal lamina covering crypts and luminal surfaces. The basal lamina on the luminal surfaces had numerous round or ovoid fenestrations, most measuring 2.5-4.0 microns. These were continuous with channels in the collagen fiber network of the lamina propria. Except very near the surface, no fenestrations were found in the basal lamina lining the crypts. Transmission electron microscopy (TEM) of serial thin sections of colonic mucosa without the epithelial cells removed showed only a few actual basal lamina fenestrations. Rarely, epithelial cell processes extended into the lamina propria through the basal lamina. Most of the fenestrations seen by SEM appeared to correspond spatially by TEM to foci of close contact between the basal lamina and underlying fibroblastic cell processes. At these sites the basal lamina and fibroblastic cell process might be removed along with the overlying epithelial cells during processing with boric acid. These data support functional differences in epithelial-stromal interaction between cell populations lining the luminal surface and those making up the crypt lining and pericryptal fibroblast sheath. The TEM findings demonstrate that the human colonic basal lamina is not absolutely continuous and that the development of basal lamina fenestrations and epithelial cell processes extending into the lamina propria is not pathognomonic of neoplastic transformation and stromal invasion.

Colon↗

PubMed1980

[Search for antimicrobial agents and their various combinations that are effective in relation to the main microfloral representatives in the burn wound].

Activity of 10 antibiotics, 6 surface active substances, 1 antioxidant and boric acid against P. aeruginosa, E. coli, Pr. vulgaris and Staph. aureus most frequently vegetating in burn wounds was studied. It was found that gentamicin had the highest antibacterial effect on the above organisms. Polymyxin M had a pronounced antimicrobial action on P. aeruginosa and E. coli. A significant antibacterial effect with respect to Staph. aureus, E. coli and Pr. vulgaris was observed with the use of the drugs of the nitrofuran line, i.e. salaful, furagin and furacillin. These drugs were not active against P. aeruginosa. A high antimicrobial effect with respect to all of the test-microbed used was recorded with methacyl, a surface active substance. To show the synergistic effect on the microbes most frequently vegetating in burn wounds, the antibacterial action of the drug combinations was studied. The synergistic effect (16 to 100 times) was observed with the use of polymyxin M combination with mafenide, carbenicillin with gentamicin, methacide with fenozan. The microorganisms tested were resistant to boric acid. On the basis of the study the most effective drugs and their combinations were chosen for their addition to the algipores (polymer coatings) used in treatment of burns infected with the above microbes.

Anti-Bacterial Agents↗