PubMed Health⌕ Search

Biomedical subjects

K K Tripathi

Publications and source records attributed to K K Tripathi.

At least 19 recordsLinked to original sources
PubMed1997

Microorganisms as an alternative source of protein.

Demand for human food and animal feed proteins from nonconventional sources has increased, particularly in developing countries. Microbial protein is one such source. It is desirable because it is amenable to controlled intensive cultivation and is less dependent on variations in climate, weather, and soil. Microbial proteins must be evaluated for nutritive value, safety, and economic considerations before mass production is undertaken.

Animals↗
PubMed1995

Rifamycins: strain improvement program.

Rifamycins are primarily produced by Gram-positive bacterium Amycolatopsis mediterranei, which belongs to the order Actinomycetales. These antibiotics, apart from their application against pathogens of tuberculosis and leprosy, have also been found to be effective against several other pathogens including Mycobacterium avium and Pneumococcus. Because of the importance of rifamycin, the producer strain A. mediterranei has been genetically manipulated since 1957 in order to develop a strain that can either produce larger amounts of rifamycin or derivatives of rifamycin. In this article, the importance of the producer strain, traditional methods (mutations and recombination) of strain improvement, their limitations, and the development of a cloning vector and transformation methods that have made recombinant DNA techniques accessible for genetic manipulations of A mediterranei are discussed.

Actinobacteria↗
PubMed1990

Lytic effect of Vibrio cholerae elastase on gram-positive and -negative bacteria.

Elastase of Vibrio cholerae caused the lysis of freshly grown cells of Gram-negative (Pseudomonas aeruginosa, Proteus vulgaris, Salmonella paratyphi A and Klebsiella pneumoniae) bacteria. Gram-positive (Staphylococcus aureus and S. epidermidis) organisms were resistant to this enzyme. Heat killed and lyophilized Gram-positive and -negative bacteria (except S. aureus and S. epidermidis) showed higher sensitivity to elastase. Both Gram-negative and -positive bacteria were lyzed maximally by elastase at pH 8.0. At this pH, lytic activity of elastase was maximum in Tris-HCl and glycine-NaOH buffers followed by Tris-maleate and cacodylate buffers.

Bacteriolysis↗
PubMed1990

Reduction in the dosage schedule of BPL-inactivated neural tissue vaccine for rabies prophylaxis in man.

There exist two different immunization schedules for neural tissue rabies vaccine (NTV) for human use in India, the amount of vaccine given by the schedule recommended by Central Research Institute (CRI), Kasauli, being higher than that recommended by Pasteur Institute of India (PII), Coonoor. A study was therefore undertaken to assess the feasibility of reducing the CRI dosage schedule for rabies prophylaxis. The antirabies antibody response in laboratory animals and human subjects following 7, 10 and 14 daily doses of NTV with or without administering rabies immune globulin (RIG) was much higher than the minimum protective level of 0.5 IU/ml of serum. Based on these results, the CRI schedule could be reduced from 14 x 5 ml of NTV to 10 x 5 ml in class II and class III rabies exposure cases.

Adult↗
PubMed1990

Oral infectivity of street and fixed rabies virus strains in laboratory animals.

Oral transmission of rabies could be produced in laboratory animals like mice, guinea pigs and hamsters using challenge virus strain (CVS) and 2 strains of street virus. Study of virus pathway following ingestion suggested predominant neural spread to brain and centrifugal spread to non neural organs like heart and kidneys. However it was found that virus dose required for oral infection was relatively very high. The role of such a transmission in nature needs to be further evaluated, keeping in view the high dose of virus required for oral infectivity and the frequency of consumption of brain by carnivorous animals.

Administration, Oral↗
PubMed1989

Post exposure studies with human diploid cell rabies vaccine and purified chick embryo cell vaccine: comparative serological responses in man.

Rabies-neutralising antibody responses to human diploid cell strain rabies vaccine (HDCSV) and purified chick embryo cell vaccine (PCECV) were studied in 125 patients previously exposed to rabid animals having received 3, 5 and 6 doses on days 0, 3, 7, 14, 30 and 90. Antibody response was significantly higher (P less than 0.05) with HDCSV than PCECV in all subjects irrespective of their sex and age group. Three doses on day 0, 3, 7 given for post-exposure rabies prophylaxis to class I patients with a negligible risk elicited antibody titres significantly higher than the minimum protective level required (0.5 I.U./ml); the mean response was greater than 15 I.U./ml in the case of PCECV and greater than 32 I.U./ml in the case of HDCSV. The use of PCECV is cost-effective and suggested for use in developing countries.

Adolescent↗
PubMed1989

Lytic effect of Pseudomonas aeruginosa elastase on gram-positive and -negative bacteria.

Elastase of Pseudomonas aeruginosa P3 caused lysis of freshly grown cells of Gram-positive (Staphylococcus aureus and S. epidermidis) and Gram-negative (Proteus vulgaris and Salmonella typhi) bacteria. Heat killed and lyophilized Gram-negative bacteria showed higher sensitivity to elastase. Both Gram-negative and Gram-positive bacteria were lysed maximally by elastase at pH 8.0. At this pH, the activity of elastase was maximal in Tris-HCl and glycine-NaOH buffers followed by Tris-maleate and Cacodylate buffers.

Bacteriolysis↗
PubMed1989

Production and partial characterization of elastase of Vibrio cholerae Inaba.

Conditions are described for the production of extracellular elastase by Vibrio cholerae Inaba 2/57. The yield of the enzyme was maximum in shake cultures grown in alkaline peptone water at 37 degrees C and was stable in culture supernatants. The enzyme, partially purified by ammonium sulphate precipitation and Sephadex G-100 gel filtration showed a molecular weight of 30,000 and an activity between pH 5.0-8.0 with an optimum of 8.0 in Tris-maleate buffer. The elastinolytic activity was maximal in glycine-NaOH buffer and minimal in phosphate buffer. The enzyme activity was adversely affected by temperature greater than or equal to 40 degrees C.

Chromatography, Gel↗
PubMed1989

Evaluation of the new rapid rabies immunodiagnosis technique.

The rapid rabies enzyme immuno-diagnosis (RREID) kit was evaluated for its sensitivity and specificity in comparison to fluorescent antibody technique (FAT) and biological test (BT) for the diagnosis of rabies. While 93 per cent correlation was observed in case of fresh brain samples, 71 per cent correlation was noted with glycerol preserved samples, where RREID was more sensitive than FAT. RREID test can be employed for rapid diagnosis of rabies, when facilities for FAT are not available. However, to test, at one time, small number of specimens, the RREID kit needs to be modified.

Animals↗
PubMed1988

Bacteriology of the cervix in cases of infertility: effect on human and animal spermatozoa and role of elastase.

Microorganisms such as Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans isolated from cervices of infertile human females inhibited motility and agglutinated human, cow bull, buffalo bull, and rat spermatozoa in vitro. Fifty percent of the infertile females studied carried elastase-positive microorganisms. Cell-free culture supernatants of 72-hr-old elastase-positive cultures were spermicidal within 60 min of contact with sperm, while elastase-negative cultures were spermicidal in 4-6 hr. Cultures of all the cervical isolates were spermicidal and agglutinated human, cow bull, buffalo bull, and rat spermatozoa, and these activities increased with age of the culture. Human sperm showed only tail-to-tail agglutination, while cow bull, buffalo bull, and rat spermatozoa showed mainly head-to-head agglutination. Spermicidal activity was also attributable to elastase, which was present more in 72-hr-old cultures than in 24-hr-old cultures.

Agglutination↗
PubMed1988

Production and partial characterization of elastase of Bacillus subtilis isolated from the cervices of human females.

Conditions are described for the production of extracellular elastase by Bacillus subtilis. The yield of enzyme was maximum in shake-cultures grown in Syncase medium at 37 degrees C and was stable in culture supernatants. The enzyme, purified by ammonium sulphate precipitation and Sephadex G-75 gel filtration, showed a molecular weight of 25,000 and activity between pH 6.0 and 9.5, with an optimum of 9.0 in Tris-maleate buffer. Elastinolytic activity was maximum in glycine-NaOH buffer and minimum in phosphate buffer. Enzyme activity was adversely affected by temperature greater than or equal to 40 degrees C.

Bacillus subtilis↗
PubMed1986

Bacteriology of cervix in cases of infertility: effect on human sperm.

Microorganisms such as Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis isolated from cervices of infertile females possessed spermicidal activity. They also agglutinated the human spermatozoa in vitro and showed tail-to-tail agglutination. Cell-free supernatant of these organisms was found to be spermicidal but did not agglutinate spermatozoa in vitro. Spermicidal activity was increased with increase in age of the culture.

Bacterial Physiological Phenomena↗
PubMed1984

Comparison of the bio-physical and biological properties of staphylococcal protein-A extracted by salt-washing and conventional procedure.

Staphylococcal protein A could be extracted in large amounts by simple stirring of the cells with physiological saline (pH 7.8). The amount of protein A obtained by the technique was found to be the same as obtained by lysozyme/lysostaphin techniques (45 micrograms/ml). The protein A extracted by salt-washing technique was of higher molecular weight (71,000) and differing in some biological properties like complement fixation from the protein A prepared by lysostaphin technique.

Adhesiveness↗