It has been hypothesized that Vibrio cholerae is an autochthonous flora of the estuarine and brackish water environment. Zooplankton and phytoplankton have been considered as possible reservoirs. The present study was carried out in microcosms to confirm the role of a cyanobacterium, Anabaena sp., as a reservoir of V. cholerae O1 using culture, polymerase chain reaction (PCR) and immunoelectron microscopy. Survival of culturable V. cholerae in microcosms was monitored by using tellurite taurocholate gelatin agar. Culturable V. cholerae were detected for up to 1 h in association with Anabaena sp. from a microcosm. However, viable but nonculturable (VBNC) V. cholerae O1 were detected for up to 25 months using PCR and immunoelectron microscopy. Results also showed that VBNC V. cholerae can multiply and maintain their progeny in the mucilaginous sheath of Anabaena sp. This is the first time that PCR and immunoelectron microscopy have been used to detect nonculturable V. cholerae in association with Anabaena sp. This study further clarifies the role of Anabaena sp. as a possible reservoir of cholera.

Anabaena↗

PubMedDate not supplied

Uptake of chloroform by skin on brief exposures to the neat liquid.

The uptake of chloroform into hairless rat's stratum corneum after application of the neat solvent directly to the skin has been studied. Tape stripping was used to determine amounts deposited within the stratum corneum and also the clearance of the compound from the skin following varied levels of exposure. Three minutes exposure to neat chloroform was adequate to achieve a limiting accumulation in the stratum corneum and thus it appears to take this long for the gradient of chloroform to be established fully across this structure. There was indication of progressively deeper penetration of chloroform as the exposure time was increased from 1 to 8 minutes. Local irritation and a loosening of the superficial layers of stratum corneum were apparent with as little as 2 minutes of exposure to the solvent and were exacerbated with further increases in exposure duration. Following exposure, clearance of the solvent from the skin surface was rapid. Interestingly, the rate of clearance, as followed by stripping, was comparable on live and freshly euthanized rats. This implies that once the exposure is terminated evaporation from the surface, and not systemic uptake by way of the local vasculature, is the predominant means of clearance at an open surface.

Analysis of Variance↗

PubMedDate not supplied

Systemic uptake and clearance of chloroform by hairless rats following dermal exposure: II. Absorption of the neat solvent.

Blood concentrations of chloroform were monitored after exposing small areas (approximately 5.5 cm2) of the backs of hairless rats to liberal excesses of the solvent for either 1, 3, or 8 min. The amounts absorbed were quantified by comparing areas-under-the-curves (AUCs) of blood concentration versus time plots to the AUC obtained on infusing an aqueous chloroform solution of known concentration for 30 min (positive control). Chloroform penetrated the dermal barrier rapidly, the skin's horny layer and the deeper skin tissues acting as reservoirs for chloroform only for short durations. Evaporative and physiological clearance from these reservoirs was rapid once the chloroform was removed from the surface. Pressure of the template used to confine the exposure affected uptake. For blood levels, the time to reach the maximum blood concentration increased with increased exposure duration. Amounts absorbed also depended on exposure duration. Blood level profiles indicated systemic uptake of chloroform following a 3-min exposure was about 1.3-fold higher than for a 1-min exposure (not significant), while the 8-min exposure produced an AUC roughly 3.8-fold higher than found at 3 min (p = 0.026). Chloroform is rapidly cleared from rat blood (terminal elimination rate constant = 0.009/min). Calculations indicated that its absorption from these area-limited exposures far exceeds that which would be absorbed had the chloroform been presented to the skin as a saturated aqueous solution.

Administration, Cutaneous↗

PubMedDate not supplied

Drug sensitivity pattern of E. coli causing urinary tract infection in diabetic and non-diabetic patients.

Escherichia coli was isolated from 65 urine samples out of 300 specimens collected from diabetic and non-diabetic patients with urinary tract infections. All isolates were screened for susceptibility to commonly used antibiotics. No remarkable difference in sensitivity pattern was observed between the E. coli isolates from diabetic and non-diabetic out-patients. However, the isolates from hospitalized diabetic patients showed a clear difference in sensitivity; E. coli from this group was more resistant to commonly used antibiotics compared with those from non-hospitalized diabetic and non-diabetic patients.

Diabetic Nephropathies↗

PubMedDate not supplied

Hyperthermia-induced apoptosis in two rat yolk sac tumor cell lines with different radiothermosensitivity in vitro.

We investigated cell susceptibility to hyperthermia-induced apoptosis in two rat yolk sac tumor cell lines (RYSTs) and attempted to correlate this with the known potentially relevant molecular determinants of apoptosis, p53 protein status, Bcl-2 family of proteins and heat shock proteins (Hsp). Parent cell line, NMT-1 (carrying wild-type p53 gene) was radiosensitive but thermoresistant compared to the variant cell line, NMT-1R (mutated type p53), which was isolated from NMT-1 by repeated radiation exposure. Induction of apoptosis by hyperthermia at 43 degrees C was morphologically detected in both RYSTs using hematoxylin and eosin, and TUNEL staining and additionally confirmed by DNA ladder formation (the cleavage of DNA into oligonucleosomal fragments). Western blot analysis showed an increase in expression of p53, p21WAF1/CIP1, Hsp70 proteins in both cell lines after heat-shock at 43 degrees C for 30 min. Hsp90 expression increased in NMT-1 but was not affected by heating in NMT-1R cells, whereas hyperthermia exerted no effect on the endogenous expression of Bax. Bcl-2 protein could not be detected in either RYST. These results suggest that hyperthermia induced apoptosis in both NMT-1 and NMT-1R and apoptosis in RYSTs may be independent of p53-dependent signaling pathway.

Animals↗

PubMedDate not supplied

[Regularion of bronchial motoricity at different levels of the bronchial tree].

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Airway Resistance↗

PubMedDate not supplied

Effect of noxious stimulants on bronchial reactivity.

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Acetylcholine↗

PubMedDate not supplied

Photoprotection of daunorubicin hydrochloride with sodium sulfite.

Protection of 10(-4) M daunorubicin hydrochloride (DNRUB) solutions against photolytic degradation was investigated using sodium sulfite (SS). Photodegradation of the drug under fluorescent light was found to be accelerated at higher pHs, and the photoprotecting ability of SS (1.9 x 10(-3) M) increased progressively with an increase in pH in the range of 3.7 to 8.2. Increase in ionic strength (mu) appeared to decrease the rate of degradation of the drug, in the presence or absence of SS, in acetate buffer (0.1 M) of pH 5.5. Photostability of DNRUB solutions was enhanced with an increase in SS concentration in pH 6.5 citrate buffer (0.1 M, mu = 0.5). The effect of various buffer species on the photostability of DNRUB was carried out using acetate, phosphate and citrate buffers. Divalent phosphate anion appeared to demonstrate the greatest catalyzing effect followed by trivalent citrate, combination of divalent and trivalent citrate (9:11 molar ratio), and monovalent acetate anion. Sodium sulfite was found to significantly diminish the catalyzing effect of all the buffers.

Antioxidants↗

PubMedDate not supplied

Effect of sodium thiosulfate on the photolysis of phenobarbital: evidence of complex formation.

Photodegradation of phenobarbital in aqueous solutions exposed to short-wave ultraviolet light was studied in presence and in absence of sodium thiosulfate. The degradation process appeared to follow first-order kinetics and was found to be dependent on pH, buffer system and sodium thiosulfate concentration. Ionic strength did not have any appreciable effect. The rate of photodegradation was found to be inversely proportional to phenobarbital concentration, especially below 8 x 10(-4) M. Solutions of phenobarbital containing alcohol, propylene glycol and benzyl alcohol as cosolvents showed markedly improved stability under UV irradiation in absence of sodium thiosulfate. Complex formation between the thiosulfate anion and phenobarbital appeared to be primarily responsible for the photostabilization of the drug. The equilibrium constant for this complex was calculated to be 36.23 M-1.

Antioxidants↗

PubMedDate not supplied

Photostabilization of dacarbazine with reduced glutathione.

Reduced glutathione was found to guard against photodecomposition (under fluorescent light) of the anticancer drug dacarbazine (DTIC). Increase in pH appeared to accelerate the degradation of DTIC within a pH range of 4.5-8.1. The stabilizing effect of reduced glutathione was found to increase with its concentration reaching an optimum value at 5 mg%. Increase of ionic strength slightly enhanced the photostability of DTIC solutions in pH 7 phosphate buffer (0.05 M). Different buffer systems at pH 4.5 did not significantly alter the degradation rate of the drug in the absence of reduced glutathione. However, in presence of reduced glutathione, dacarbazine appeared to be less stable in acetate buffer of pH 4.5.

Buffers↗