Cytosolic pyridoxine-beta-D-glucoside hydrolase from porcine jejunal mucosa. Purification, properties, and comparison with broad specificity beta-glucosidase.

During studies of the nutritional utilization of pyridoxine 5'-beta-D-glucoside, a major form of vitamin B6 in plants, we detected two cytosolic beta-glucosidases in jejunal mucosa. As expected, one was broad specificity beta-glucosidase that hydrolyzed aryl beta-D-glycosides but not pyridoxine beta-D-glucoside. We also found a previously unknown enzyme, designated pyridoxine-beta-D-glucoside hydrolase, that efficiently hydrolyzed pyridoxine beta-D-glucoside. These were separated and purified as follows: broad specificity beta-glucosidase 1460-fold and pyridoxine-beta-D-glucoside hydrolase 36,500-fold. Purified pyridoxine-beta-D-glucoside hydrolase did not hydrolyze any of the aryl glycosides tested but did hydrolyze cellobiose and lactose. Pyridoxine-beta-D-glucoside hydrolase exhibited a pH optimum of 5.5 and apparent molecular mass of 130 kDa by SDS-polyacrylamide gel electrophoresis and 160 kDa by nondenaturing gel filtration, in contrast to 60 kDa for native and denatured broad specificity beta-glucosidase. Glucono-delta-lactone was a strong inhibitor of both enzymes. Ionic and nonionic detergents were inhibitory for each enzyme. Conduritol B epoxide, a potent inhibitor of lysosomal acid beta-glucosidase, inhibited pyridoxine-beta-D-glucoside hydrolase but not broad specificity beta-glucosidase, but both were inhibited by the mechanism-based inhibitor 2-deoxy-2-fluoro-beta-D-glucosyl fluoride. Our findings indicate major differences between these two cytosolic beta-glucosidases. Studies addressing the role of vitamin B6 nutrition in regulating the activity and its consequences regarding pyridoxine glucoside bioavailability are in progress.

Determinants of AIDS preventive behaviour among dental professionals.

This study was conducted to assess concerns regarding AIDS and to identify determinants of poor preventive behaviour among dentists. Questionnaires were distributed to a random sample of 342 professionals. Respondents showed the lowest knowledge scores on topics dealing with symptoms, epidemiology and AIDS control. The predictors of poor AIDS knowledge were: more than ten years of practice and a strong belief to be professionally susceptible to HIV infection. Sterilization of high speed drills was disappointing; only 14.2% of dentists reported using heat sterilization. Predictors of poor preventive behaviour were: poor ability in clinical AIDS identification, more than ten years of practice and poor knowledge of AIDS prevention and control. Dental burs were the major cause of occupational injury. Professionals who recap needles are three times more likely to sustain needlesticks than those who do not. Our results suggest the need to increase AIDS knowledge and to improve compliance to infection control measures among dentists.

Treatment of arthritis with topical capsaicin: a double-blind trial.

The neuropeptide substance P has been implicated in the pathogenesis of inflammation and pain in arthritis. In this double-blind randomized study, 70 patients with osteoarthritis (OA) and 31 with rheumatoid arthritis (RA) received capsaicin (a substance P depletor) or placebo for four weeks. The patients were instructed to apply 0.025% capsaicin cream or its vehicle (placebo) to painful knees four times daily. Pain relief was assessed using visual analog scales for pain and relief, a categorical pain scale, and physicians' global evaluations. Most of the patients continued to receive concomitant arthritis medications. Significantly more relief of pain was reported by the capsaicin-treated patients than the placebo patients throughout the study; after four weeks of capsaicin treatment, RA and OA patients demonstrated mean reductions in pain of 57% and 33%, respectively. These reductions in pain were statistically significant compared with those reported with placebo (P = 0.003 and P = 0.033, respectively). According to the global evaluations, 80% of the capsaicin-treated patients experienced a reduction in pain after two weeks of treatment. Transient burning was felt at the sites of drug application by 23 of the 52 capsaicin-treated patients; two patients withdrew from treatment because of this side effect. It is concluded that capsaicin cream is a safe and effective treatment for arthritis.

Preoperative diagnosis of gallbladder disease.

The following protocols should be observed in evaluating a patient with suspected cholecystitis: In evaluating chronic cholecystitis in patients on a diet containing fat, plain films of the abdomen and oral cholecystogram are the procedures of choice. If the gallbladder fails to fill after ingestion of 3 g iopanoic acid, the procedure is repeated with an additional 3 g the following day. Failure of the gallbladder to visualize after a two-day study, equivocal findings, or persistent symptoms despite a normal study should be followed by ultrasound and, if necessary, cholescintigraphy. The latter two studies should be done in a fasting state, and CCK used to demonstrate gallbladder contraction during both tests. In suspected acute cholecystitis, plain radiography, ultrasound, and Tc-99m-imino diacetic acid derivative scanning should be performed. Again CCK should be used during cholescintigraphy to verify nonvisualization and to stimulate gallbladder emptying.

Oocyte aneuploidy screening using superovulating prepubertal mice: effect of methotrexate.

Numerical chromosomal aberrations (aneuploidy) are a major factor in pregnancy wastage, birth defects, and mental retardation. Consequently, effective cytogenetic procedures in mammalian gamates are required for studying mechanisms and causes of chromosomal nondisjunction. Our aims were to determine for oocytes from superovulating prepubertal mice: (1) the yield of chromosomally scorable ova, following application of a double fixation procedure: (2) the background level of aneuploidy, and (3) the sensitivity to induction of aneuploidy (by methotrexate). Superovulation was induced in C129F1 hybrid mice, 22-24 days old, with pregnant mare serum and human chorionic gonadotropin (HCG). Diurnal photoperiodicity and injections were scheduled to assure HCG-induced ovulation of known timing. Methotrexate (200 mg/kg) was given at 3 hr and ova were recovered at 15 hr after HCG. We describe the adaptation of a double fixation procedure to mouse oocytes. Methotrexate led to significantly increased hypoploidy (2 1/2-fold) but not to the hyperploidy reported by others for adult mice. There was a high yield of ova with exactly countable chromosomes (average of 9.5 ova per mouse). Concomitantly, the background level of aneuploidy was very low (0/465 scorable ova were hyperploid). Given the additional advantages of economy and convenience, the superovulating 3-week-old mouse could be an effective source of ova for testing environmental agents for their aneuploidy-inducing potential; however, further studies are needed to establish the degree to which such ova are susceptible to aneuploidy induction.

Extraperitoneal perirectal extravasation of barium during a barium enema examination: natural course and treatment.

Sixty cases of extraperitoneal intramural and perirectal extravasation of barium during a barium enema examination are reviewed. Approximately half the patients were asymptomatic and of these only one experienced serious complications. In the remaining patients, symptoms included pain, bleeding, fever, sepsis, mass and/or discharge. Morbidity and mortality was considerable despite aggressive treatment in many cases. Delay of treatment resulted in increase mortality and morbidity.

[The phenotype Hp O in several African and Central American populations]. / Le phénotype Hp O dans quelques populations d'Afrique et d'Amérique centrale.

This work shows the higher probability for some individuals of having Hp O phenotype: that is, children under twelve, and individual carriers of haemoglobin S (haemoglobin D carriers do not present this characteristic). This observation appears as a confirmation of the hypotheses explaining Hp O phenotype as a consequence of haemolytic anaemia. Besides, the test of two genetic models taking into account both Hp O and Hp21 M phenotypes leads to strong difficulties due to a certain irregularity of "haptoglobin" genetic system.