Mechanistic studies on carboxypeptidase A from goat pancreas: role of arginine residue at the active site

Chemical modification of carboxypeptidase Ag1 from goat pancreas with phenylglyoxal or ninhydrin led to a loss of enzymatic activity. The inactivation by phenylglyoxal in 200 mM N-ethylmorpholine, 200 mM sodium chloride buffer, pH 8.0, or in 300 mM borate buffer, pH 8.0, followed pseudo-first-order kinetics at all concentrations of the modifier. The reaction order with respect to phenylglyoxal was 1.68 and 0.81 in 200 mM N-ethylmorpholine, 200 mM NaCl buffer and 300 mM borate buffer, pH 8.0, respectively, indicating modification of single arginine residue per mole of enzyme. The kinetic data were supported by amino acid analysis of modified enzyme, which also showed the modification of single arginine residue per mole of the enzyme. The modified enzyme had an absorption maximum at 250 nm, and quantification of the increase in absorbance showed modification of single arginine residue. Modification of arginine residue was protected by beta-phenylpropionic acid, thus suggesting involvement of an arginine residue at or near the active site of the enzyme.

Differential responses of sunflower (Helianthus annuus cv. Modern) towards high and low concentrations of dikegulac sodium

In pot experiments, foliar application of dikegulac sodium (2,3:4-6-di-O-isopropylidene-α-L-xylo-2-hexalofuranosate) at 500 and 750 μg/mL inhibited plant growth and decreased growth and dry matter production of the treated leaves of sunflower (Helianthus annuus L. cv. Modern). A concentration of 100 μg/mL, however, increased leaf area and anabolic activities of treated leaves. Increased cambial activity was noted at all concentrations of dikegulac, which resulted in formation of secondary tissues. At 500 and 750 μg/mL RNase and protease activities increased appreciably, while catalase activity was drastically suppressed. The inhibitory effect of dikegulac was also found in newly expanding leaves which developed after treatment. Beneficial effects of dikegulac at low concentration were also reflected in field experiments where increased yield was noted, while high concentrations were distinctly inhibitory. The importance of dikegulac as an agronomically promising chemical for sunflower is discussed.

Polyarthritis with atypical keratotic nodular dermatosis or polyarthritis with multiple keratoacanthoma. A case report

We report an interesting case of generalized papular and nodular lesions with central keratinous plugs and severe hyperkeratotic-acanthotic histopathology with arthritis in a 19-year-old male patient who had suffered from a similar disease 2 years earlier. Papules and nodules erupted a few days after the arthritis and this was noticed during both episodes. On healing, nodules fell spontaneously leaving behind insignificant hyperpigmented scars.

Studies on synthesis and uptake of taurine in rat lens in vitro

The occurrence of large taurine pool sizes in the crystalline lens was further elucidated by studying the in vitro synthesis and uptake of taurine in the rat lens. It was observed that a time- and concentration-dependent synthesis of taurine from methionine occurred in the rat lens. The time curve for uptake was linear up to 4 hr and was not saturated up to 40 mM concentration of taurine. The uptake was inhibited by ouabain, cyanide, Ca2+, GTP and cGMP but was not affected by ATP and cAMP. It is suggested that a dual mechanism exists for maintenance of high concentrations of taurine in the lens. Moreover, the uptake mechanism is energy-dependent.

Distribution of taurine in the crystalline lens of vertebrate species and in cataractogenesis

Marked heterogeneity was observed in the distribution of taurine in different regions of the lens in various species. In general low taurine pools were observed in the nucleus of all species except frog and human. The distribution of taurine in human senile cataractous lenses at different stages of maturation showed decreased contents in all the regions except capsule epithelium as compared to the normal human lenses. This decrease is progressive upto the 'mature' stage of cataract. In rat lenses with galactose cataracts taurine contents decreased by about 83-94% of the normal values in the equatorial, anterior, posterior cortical and nuclear regions.

An immunofluorescence study of anti-pancreatic islet cell antibodies in the spontaneously diabetic BB Wistar rat

Sera from BB Wistar rats and Wistar control rats were evaluated for the presence of islet cell antibodies in a prospective study using an indirect immunofluorescence assay on pancreatic islet cell suspensions from cultured rat islets. Islet cell surface antibodies were detected in sera from all animals of the spontaneously diabetic BB Wistar rat colony. The antibody could be detected well before the clinical onset of the disease and was present throughout the course of study of all diabetic animals. Sera from control Wistar rats were negative when tested for this antibody.

Strain and sex differences in serum alpha-fetoprotein levels in Mus musculus

Normal levels of circulating serum alpha-fetoprotein (AFP) in different inbred strains of mice, as determined by radioimmunoassay, are reported. These strains show different and characteristic values for the mean serum AFP concentration, suggesting genetic control of the serum level of this protein. Furthermore, within each strain a difference in serum levels of the protein is observed between sexes; males have a significantly higher serum AFP concentration.

A study of interaction of low-dose combination oral contraceptive with Ampicillin and Metronidazole

Plasma levels of norethisterone (NET), ethinyl estradiol (EE), Ampicillin or Metronidazole were estimated in 16 women, who were taking low-dose oral combination contraceptive pills (containing norethisterone acetate 1 mg and ethinyl estradiol 30 microgram) and in whom concurrently, either Ampicillin (6 women) or Metronidazole therapy (10 women) was given. Neither Ampicillin nor Metronidazole therapy altered the 'peak' or 24-hour plasma levels and area under the curve, for NET and EE. Furthermore, oral contraceptive treatment did not alter the 'peak' levels of Ampicillin or Metronidazole. Progesterone (P) levels were in the anovulatory range in all Ampicillin treated cycles. However, in Metronidazole treated group, two out of 10 women showed a P rise of more than 4 ng/ml. The study was expanded to include another group of 15 women treated with Metronidazole, where only one women showed a P rise of more than 4 ng/ml. The occurrence of 'escape ovulation' as suggested by P rise of more than 4 ng/ml in three out of 25 Metronidazole treated women is either a chance incidence due to a different pharmacological response in them, or most probably due to the default in the regular intake of pills in these women. This is supported by the observation that one out of three women showing a P rise (greater than 4 ng/ml( during concurrent Metronidazole therapy, also showed ovulatory P values in oral contraceptive-only treated cycles. Furthermore, in the control group also, one out of 10 women had ovulatory P levels (greater than 4 ng/ml) in oral contraceptive-only treated cycles.

Measurement of antipyretic activity of ibuprofen and paracetamol in children

The antipyretic activity of ibuprofen (Brufen) and paracetamol (Crocin) was compared in 22 children with pyrexia who received either ibuprofen or paracetamol in syrup form. Both axillary and rectal temperatures were recorded prior to drug administration and 1/2, 1, 2, 3, 4, 5, 6, 8, and 12 hours after dosing. Analysis of the results in terms of rate of temperature decrease and degree and duration of decrease in temperature indicated that both drugs produced significant reduction in temperature and in the rate of temperature decrease. The maximum effect of the two drugs was similar. However, ibuprofen was more effective than paracetamol at 6 and 8 hours after administration, and its duration of action was longer. The associated antipyretic and antiinflammatory features of ibuprofen could provide an advantage in the control of exudative forms of upper respiratory tract infections.

A study of interaction of a low-dose combination oral contraceptive with anti-tubercular drugs

Low-dose combination contraceptive (containing norethisterone acetate 1 mg and ethinyl estradiol 30 micrograms) was administered to women receiving concurrent therapy with either Rifampicin or "triple" antitubercular treatment consisting of paraaminosalicylic acid (PAS), isonicotinic acid hydrazide (INH) and streptomycin. Plasma levels of norethisterone (NET) and ethinyl estradiol (EE), PAS and INH were measured and the area under curve (AUC) was calculated for NET and EE. Rifampicin treatment (9 women) caused a statistically significant reduction of the plasma NET levels as well as the AUC of NET. In this group of women, though a trend for reduction in EE levels was observed in individual subjects, it was not statistically significant. Out of 7 regularly menstruating women on Rifampicin therapy, 2 showed a premenstrual rise of plasma progesterone (P) levels (> 4 ng/ml) suggesting an ovulatory cycle and 3 experienced menstrual irregularities. In contrast, plasma levels of NET and EE as well as their AUCs were not altered in 8 women receiving "triple" antitubercular therapy. Only one woman out of 8, had menstrual irregularity and all women had P levels in the anovulatory range. Furthermore, oral contraceptive treatment did not alter the plasma levels of PAS and INH.

Accidental poisoning in children in Lusaka

An analysis of 378 cases of accidental poisoning by ingestion or inhalation in children admitted to the University Teaching Hospital, Lusaka, in 1978, is presented. The distribution was as follows: paraffin poisoning (57.1%), food poisoning (18.3%), other household poisons (11%) and "medicines" (10.8%). In 9 cases poison could not be identified. Two patients (0.5%) died.