Enzymatic mechanism and biochemistry for cyanide degradation: a review.

Cyanides are fast-acting poisons, can be lethal if exposed in excess. In spite of fact, cyanides are discharged as effluents in large scale from industries every year. Certain bacteria, fungi, algae and plants produce cyanides. It has been observed that microbes and plant systems can degrade cyanides to less toxic compounds. There are many enzymes, which are produced by microorganisms that utilize cyanides as substrate to make alanine, glutamic acid, alfa-amino-butyric acid, beta-cyanoalanine, etc. Present paper deals with different enzymes, their mechanisms and corresponding pathways with respect to the known biochemistry of enzyme and feasibility for the use in treatment of cyanides containing industrial effluents.

Japanese Encephalitis : Is Routine Immunization Required?

Japanese encephalitis is the leading cause of viral encephalitis in Asia. In endemic areas annual incidence ranges from 10-100 per 100000 population. Case fatality averages 30% and a high percentage of the survivors are left with permanent neuropshychiatric sequelae. There is no effective drug treatment for this disease. In recent decades, Japanese encephalitis virus has caused epidemics in previously unaffected countries like India, Myanmar, Nepal, Sri Lanka, Thailand and Viet Nam. No effective environmental control is known. Although socioeconomic improvement and changes in agricultural practices are likely to reduce viral transmission, large-scale vaccination of affected populations with an effective and affordable vaccine appears logical at least in the short term. The impact of large-scale Japanese Encephalitis vaccination is documented in some regions of China and systematic vaccination has contributed to significant decline in incidence in Japan, Republic of Korea and Thailand.

Effect of long-term dehydration on serum constituents in extreme climatic conditions in camel (Camelus dromedarius).

Eight healthy female adult camels were used to study the effect of long term dehydration on serum constituents in extreme climatic conditions viz. cold and hot. The dehydration phases were of 24 days in cold and 13 days in hot conditions. The changes in sodium, potassium, calcium and phosphorus were non significant (P > 0.05) while in chloride, glucose, total proteins, urea, bilirubin, cholesterol and creatinine were significant (P < or = 0.05) during dehydration phase. The mean values of all the constituents tended to return to normal as the rehydration phase advanced. Changes in sodium and potassium in dehydrated camels reflected that they were able to maintain the salt balance.

Preoperative sonographic diagnosis of acute appendicitis caused by Ascaris lumbricoides.

Acute appendicitis caused by Ascaris lumbricoides is an uncommon variant of a common disease. We describe a case in which sonography was used for preoperative diagnosis of ascaris appendicitis.

Quantitative analysis of HBY 097 and its metabolites in human serum and urine by HPLC.

Two HPLC methods were developed: one for the quantitation of HBY 097 reverse transcriptase inhibitor and its metabolites M2 and M3 in human serum, and one for the quantitation of metabolite M5 in urine. The HPLC procedure for the quantitation of HBY 097 and its metabolites M2 and M3 in human serum involved protein precipitation with acetonitrile followed by automated on-line trace enrichment. The HPLC procedure for the analysis of metabolite M5 in urine involved enzymatic hydrolysis of urine with beta-glucuronidase to convert metabolite M5 (glucuronide of M3) to M3. Reverse phase chromatographic separation with gradient elution. UV detection at 335 nm, and internal standard were used to quantitate analytes in both procedures. The lower quantitation limits were 25 ng ml-1 for HBY 097 and metabolites M2 and M3 in serum, and 0.5 microgram ml-1 for the metabolite M5 in urine measured as metabolite M3 after hydrolysis. The HBY 097 and metabolite M3 concentrations were specific but metabolite M2 was semi-specific because the two diastereomers of M2 were not resolved by the present chromatographic procedure. Both procedures were applied to the quantitation of HBY 097 and its metabolites in serum and urine of HIV positive patients who were enrolled in a clinical study of drug safety and pharmacokinetics.

Modified Levinson's test in rapid diagnosis of tuberculous meningitis.

Modified Levinson's precipitation test was done in 64 cases of TBM, 54 cases of TBM with inconsistent CSF finding, and 32 cases of pyogenic meningitis. The test was positive in 93.7% cases of TBM (sensitivity, 93.7%), 85.5% cases of TBM with doubtful diagnosis and in 9.4% cases of pyogenic meningitis (specificity 90.6%) compared to 79.7%, 72.2% and 18.8% in original Levinson's test, respectively. With CSF examination only 66% cases of TBM could be diagnosed while with modified Levinson's test and CSF analysis 89% cases could be diagnosed (p < 0.001). So modified Levinson's test for diagnosis of TBM is better than Levinson's test (p < 0.05) with an added advantage of time saving.

High-performance liquid chromatographic methods for the determination of sulfonamides in tissue, milk and eggs.

In the last decade, significant research has been done to improve the existing high-performance liquid chromatographic (HPLC) methods and also towards developing simple, reliable and sensitive HPLC methods for sulfonamides in meat, milk and eggs. The replacement of solvent extraction with solid-phase extraction or matrix solid-phase dispersion techniques is a step forward. Significant improvements in sensitivity have been achieved. This review concentrates on HPLC methods for the determination of sulfonamides in foods of animal origin published after 1980. The existing methods are critically evaluated and suggestions for future research are made.

Surgical manifestations of ascariasis in childhood.

Amongst 50 patients with surgical complications of Ascaris lumbricoides 35 patients (70%) were treated conservatively and 15 patients (30%) required surgical intervention which included squeezing of worms to distal colon, resection and anastomosis of ileum, appendicectomy and peritoneal lavage. Intestinal perforation was observed in 3 cases. Two patients (4%) died because of postoperative complications. Those presenting with subacute intestinal obstruction had no mortality or morbidity. Although a large number of roundworms were seen in the jejunum, the obstruction was generally observed in the distal ileum.

A new procedure for the isomerization of vitamin D and its metabolites.

A new procedure for the isomerization of vitamin D and its metabolites is described. Vitamin D or its metabolites are dissolved in 100 microliters methanol and 10 M HC1 in 2-butanol is used as the reagent for isomerization. The isomerization reaction is carried out at 5 degrees C for 2-3 min which gives quantitative yields of isotachysterols down to 10 ng level without use of any carrier.

Comparative antifilarial efficacy of the N-oxides of diethylcarbamazine and two of its analogues.

The N-oxides of 1-diethyl carbamoyl-4-methyl piperazine (DEC), 3-ethyl-8-methyl, 1,3,8-triazabicyclo (4,4,0) decan-2-one (centperazine) and 1-methyl-4-(pyrrolidin-1-yl-carbonyl) piperazine (CDRI Comp. 72/70) have been evaluated against Limotosoides carinii infection in cotton rats to establish whether conversion of the three antifilarials into N-oxides would lead to exertion of better antifilarial activity. Of the three N-oxides, N-oxide of DEC showed significantly more suppressive effect on circulating microfilariae in comparison to its parent compound. However, adult worms were unaffected. It was observed that basicity of the N-CH3 group did not play major role in exertion of activity of DEC and related compounds. Nevertheless, two other N-oxides were inactive.

Liquid chromatographic determination of vitamin D in infant formula.

A method is described for the determination of vitamins D2 + D3 in milk- and soy-based infant formula. Vitamins D2 and D3 are extracted from the saponified sample and converted to isotachysterols with acidified butanol. Reverse-phase liquid chromatography (LC) is used to remove interferences, and total vitamin D is quantitated using normal-phase LC. Recoveries of spiked samples averaged 97.6% for milk-based infant formula, and 98.8% for soy-based infant formula. This method quantitates vitamin D2 + D3 in infant formulas containing as low as 40 IU/qt when prepared according to label direction.

Circulating concentrations of thyroid hormones in pregnant camels (Camelus dromedarius ).

Blood samples from 16 female camels were collected at monthly intervals commencing from 60 d post. breeding until the last month of gestation. Two camels failed to conceive and two had unnoticed abortions. The average gestation period was 398+/-13 and 372+/-11 in camels bearing male and female fetus, respectively, with an overall mean of 383+/-9 d. Sera were analyzed for thyroxine (T(4)) and triiodothyronine (T(3)) by radioimmunoassay. Mean T(4) and T(3) concentrations varied from 76 to 116 ng/ml and 0.73 to 1.32 ng/ml, respectively, during various stages of gestation. In general, the T(4) and T(3) levels were higher during early pregnancy, with lowest values in the tenth month. T(4):T(3) ratio showed minor, nonsignificant fluctuations. Age of dam of sex of fetus had no effect on hormone levels. Similarly, hormone levels were not affected by failure of conception or by abortion.

The adsorption of nucleotides and polynucleotides on montmorillonite clay.

The binding of adenine derivatives to Na(+)-montmorillonite increases in the order 5'AMP, 3'-AMP, 5'ADP < adenosine < purine, adenine. With the exception of cytosine, cytosine derivatives bind less strongly than the corresponding adenine derivatives in the order 5'-CMP < cytidine < cytosine. There is little difference in the binding of uracil derivatives and these compounds bind less strongly than the corresponding adenine analogs. It is concluded that the adenine ring in adenine derivatives is protonated by the acidic montmorillonite surface and binding is a consequence of the electrostatic interaction between the protonated base and the negative charges on the surface of the montmorillonite. Different binding trends were observed with Cu(2+)-montmorillonite with AMP binding more strongly than adenosine and UMP binding more strongly than uridine. It is concluded that ligation to the Cu2+ is a major force in the binding of nucleotides to Cu(2+)-montmorillonite and are not readily washed from the clay. Factors contributing to the binding are discussed. Watson-Crick hydrogen bonding of 5'-AMP to poly(U) and 5'GMP to poly(C) was observed when the homopolymers are bound to the surface of the clay. No association of 5'-UMP to poly(U) bound to clay was detected. The possible role of montmorillonite clays in the prebiotic formation of RNA is discussed.

Simultaneous determination of D- and L-malic acids in apple juice by gas chromatography.

A gas chromatographic (GC) method was developed for the simultaneous determination of D- and L-malic acids in apple juice. D-Malic-(R)-(-)-2-butyl ester and L-malic-(R)-(-)-2-butyl ester are prepared with (R)-(-)-2-butanol. These diastereomers are separated and quantitated by gas chromatography on a Carbowax 20M (30 m x 0.25 mm) fused silica capillary column. This procedure does not involve any extraction or cleanup step.