Search PubMed⌕ Search

Biomedical subjects

V M Katoch

Publications and source records attributed to V M Katoch.

At least 91 records · Page 5Linked to original sources
PubMed1983

Hepatitis-B virus infection in patients with leprosy--a brief communication.

The prevalence rate of hepatitis-B surface antigen (HBsAg) were determined in 413 patients of different types of leprosy and 133 healthy controls from the same population, in a study undertaken over a period of more than 3 years. The average frequency of australia antigen (HBsAg) was 7.7% in leprosy cases as compared to 6.0% in their healthy counterparts. Across the spectrum 7.2% of lepromatous patients (LL); 8.5% of borderline lepromatous (BL); 9.1% of borderline borderline (BB); 8.6% of borderline tuberculoid (BT) and 8.8% of tuberculoid (TT) cases were positive for HBsAg. Though the prevalence of australia antigen was slightly higher in borderline tuberculoid, borderline borderline and tuberculoid cases, it is not statistically significant. No association between carriership of HBsAg and lepromatous leprosy could be found in the present study.

Adult↗
PubMed1982

Biochemical correlation of M. vaccae with M. leprae.

The biochemical tests, namely, niacin, catalase, nitrate reduction, tween hydrolysis, tellurite reduction, arylsulfatase and urease tests were carried out for all the mycobacteria which are immunogenically closely related to M. leprae. Among them only M. vaccae shows closest relationship with M. leprae when compared with its communicated data. Except for the tellurite reduction test which was variable in case of M. leprae, all the other tests were found similar to that of M. leprae. In the next experiment, the thin-layer chromatographic pattern of mycolates from M. leprae has been compared with that of M. leprae. The presence of Keto-mycolate in the cell wall structure of both M. vaccae and M. leprae also reflects their biochemical relationship at their ultrastructural level.

Cell Wall↗
PubMed1981

A report on the biochemical analysis of Mycobacterium W.

A mycobacterial strain known as Mycobacterial strain W was analysed for its growth characteristics and biochemical traits. This strain was found to be a rapid grower, with luxurient growth on Lowenstein-Jensen medium, Dubos agar, Middlebrook's agar and Sauton's medium. Colonies were smooth, convex and nonpigmented. Some of the colonies which appeared rough were similar to smooth colonies at least in biochemical characteristics. This organism was tolerant to wide range of temperatures and to chemical substances like thiophene - carboxylic acid hydrazide, isoniazid, sodium chloride but not to bile salts. It was negative for niacin production, for various amidases, urease production, 3 day arylsulfatase test and also for Tween 80 hydrolysis. On the other hand this strain was found to be positive for semiquantitative catalase, heat resistant catalase, nitrate reduction, sodium salicylate degradation, tellurite reduction, 14 day arylsulfatase test and fermentation of fructose. This organism could utilize sodium nitrate and sodium nitrite as sources of nitrogen but didn't exhibit any utilization of fructose, arabinose as only sources of carbon. Significance of these findings is discussed.

Mycobacterium leprae↗
PubMed1980

A bacteriological and histopathological study of apparently normal skin in lepromatous leprosy.

A comparative study of clinically affected and apparently uninvolved skin in lepromatous patients has been undertaken in 22 cases. Parameters studied include skin smears for bacillary Index; bacillary load/gm of tissue and histopathological comparison of granuloma fraction and biopsy index. The results showed that the clinically unaffected sites have a lower bacillary index and lesser bacterial load. Histologically the granulomas were smaller and biopsy index was lower in uninvolved areas. The possible reasons for this comparative less involvement are discussed.

Adolescent↗
PubMedDate not supplied

Study of gene probes in childhood leprosy.

The objective was to detect nucleic acids of M. leprae in skin lesions of leprosy patients and study the effect of treatment on these nucleic acids, using r-RNA gene probes, using a cross sectional study. The study was carried out at Department of Paediatrics, S.N. Medical College, Agra and Department of Microbiology, Central JALMA Institute for leprosy, Agra. The study included 32 cases of leprosy less than 16 years of age, divided into 3 groups viz. without treatment (12 cases), in middle of treatment (11 cases) and at the end of treatment (9 cases). All cases were subjected to a detailed history and thorough clinical examination. All of them had smear examination and lepromin test done and their skin biopsies were subjected to gene detection. Nucleic acids were isolated from skin biopsies of all cases by standard procedure. After dot blotting of these nucleic acids, they were hybridised with radioactive (p32) r-RNA probes. The results were interpreted after getting the X-ray films processed with background signals from controls. Majority of cases were between 13-16 years of age. As age advanced, the disease moved from tuberculoid end of spectrum towards lepromatous end (p < 0.05). Majority of paucibacillary (PB) cases were lepromin positive while majority of multibacillary (MB) cases were lepromin negative (p < 0.05). In specimens of untreated cases, 50% of PB specimens and 87.5% of MB specimens were positive for r-RNA probes. In multibacillary type 100% smear positive specimens and 67% smear negative specimens were positive for r-RNA probes. In patients during the middle of treatment positivity for r-RNA decreased and 20% of PB specimens and 16.6% MB specimens were positive. At the end of treatment (1 year for PB cases and 2 years for MB cases), the results of r-RNA were negative, which indicated that the treatment regimens used in the study were effective. This study supports the usefulness of r-RNA probes as a diagnostic and therapeutic tool in childhood leprosy.

Adolescent↗
PubMedDate not supplied

Molecular genetic analysis of multi-drug resistance in Indian isolates of Mycobacterium tuberculosis.

A total of 116 isolates from patients attending the out-patient department at the All India Institute of Medical Sciences, New Delhi and the New Delhi Tuberculosis Centre, New Delhi, India were collected. They were analyzed for resistance to drugs prescribed in the treatment for tuberculosis. The drug resistance was initially determined by microbiological techniques. The Bactec 460TB system was employed to determine the type and level of resistance in each isolate. The isolates were further characterized at molecular level. The multi-drug loci corresponding to rpo beta, gyr A, kat G were studied for mutation(s) by the polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) technique. The SSCP positive samples were sequenced to characterize the mutations in rpo beta, and gyr A loci. While previously reported mutations in the gyr A and rpo beta loci were found to be present, several novel mutations were also scored in the rpo beta locus. Interestingly, analysis of the gyr A locus showed the presence of point mutation(s) that could not be detected by PCR-SSCP. Furthermore, rifampicin resistance was found to be an important marker for checking multi-drug resistance (MDR) in clinical isolates of Mycobacterium tuberculosis. This is the first report on molecular genetic analysis of MDR tuberculosis from India, and highlights the increasing incidence of MDR in the Indian isolates of M. tuberculosis.

Humans↗
PubMedDate not supplied

Chemotherapy trial in paucibacillary leprosy using clofazimine.

In a double blind study, 300 PB patients (smear negative, indeterminate, tuberculoid and borderline tuberculoid) were randomly allotted to two regimens, the control subjects (150 patients) receiving the standard WHO multidrug regimen of six doses of once a month rifampicin with daily dapsone therapy for six months, while the study group (150 patients) receiving 50 mg of clofazimine daily for six months in addition to the WHO regimen. After stoppage of therapy all the patients were followed up on placebo. The regimens were well tolerated. In 7.5% of patients on clofazimine containing regimen, the lesions showed persisting activity at the time of stoppage of therapy, compared with 16% on the control regimen. This activity subsided spontaneously, more rapidly, in the study group (80% compared with 30% in the control group) in six months. Two patients in the control group and one patient in the study group developed late reaction. There were no relapses in the study group, whereas, two patients have relapsed in the control group during a follow-up of 2.5 to 3.5 years.

Clofazimine↗
PubMedDate not supplied

Drug resistance in leprosy: lessons from past and future perspective.

Some recent studies indicate that the problem of drug resistance in leprosy is very much there but the exact picture is not clear. In the emerging scenario with increasing number of new cases with low bacterial load, the conventional in-vivo and most of current in-vitro methods for determination of drug resistance may not help. It is pointed out that newer molecular approaches may be more useful and that it will be important to undertake studies to develop such tools.

Clofazimine↗
PubMedDate not supplied

Assessment of viability by normal mouse foot-pad and bacillary ATP bioluminescence assay in multibacillary cases treated with an MDT regimen using conventional as well as newer drugs like minocycline and ofloxacin.

The therapeutic effect of a drug regimen of conventional drugs as well as newer drugs like ofloxacin and minocycline in smear-positive multibacillary (MB) leprosy cases was assessed by mouse foot-pad and ATP bioluminiscence methods. Biopsies were taken before starting treatment and after one year of treatment. They were processed for viability assessment by normal mouse foot-pad inoculation and bacillary ATP assay techniques. The test regimen was quite effective in its anti-bacterial effect as it was found to result in loss of bacillary viability in all the cases, as assessed by both methods.

Adenosine Triphosphate↗
PubMedDate not supplied

Patients presenting with defined areas of sensory loss--a preliminary study.

Thirty patients presenting with circumscribed areas of clearly demonstrable hypoesthesia were chosen from amongst those attending this Institute. Their history and clinical features were recorded, lepromin test was done for reading at four weeks, and peripheral part of the hypoesthetic area was biopsied for histopathology and immunostaining. The subjects were predominantly adult males with the symptomatic sites limited to the extremities. On routine histopathological examination of the symptomatic sites, the diagnosis of leprosy, using defined criteria, could be made in six cases (20%). Immunostaining of the remaining sections showing either no pathology or a nonspecific pathology revealed the presence of mycobacterial antigen in five of the 24 cases (20.83%). Overall, leprosy could be diagnosed in 11 of the 30 cases studied (36.66%). This study shows that leprosy may be an important cause of circumscribed areas of sensory deficit.

Adolescent↗
PubMedDate not supplied

Correlation between inhibitory effect of quinolones and mycolic acid metabolism in mycobacteria.

Mycolic acids are important components having a significant role in maintaining the rigidity of mycobacterial cell wall. They could also be the barrier for penetration of certain drugs into the bacterial cell. A novel in vitro model system was established for assessing the effect of Ciproflaxacin on mycolic acid metabolism in pathogenic mycobacteria M. Kansasii (which has similar mycolic acid pattern to that from M. leprae) and the effect of norfloxacin in M. intracellulare. These test mycobacteria were exposed in their midlogarithmic phase of growth to 0.5, 1, 2, 3, 4, 5 and 6 micrograms ml of ciprofloxacin and norfloxacin respectively for 1, 2 and 24 hours. Ciprofloxacin completely inhibited the synthesis of mycolates in M. kansasii at 3, 4 and 5 micrograms/ml; whereas norfloxacin exhibited its maximum inhibitory action on mycolic acids in M. intracellulare at 6 micrograms/ml for all the durations of exposure. Inhibition of mycolates directly correlated with bacterial viability which was estimated by colony forming units. The effect of quinolones on mycolic acid metabolism appears to be direct and not secondary to DNA gyrase. The results obtained from this study and our previous findings show that mycolic acid metabolism is affected by various groups of drugs, whose primary sites of activity may be different. The findings of the present study may have significant therapeutic implications in leprosy and other mycobacterial diseases.

Ciprofloxacin↗
PubMedDate not supplied

Adenosine deaminase activity in leprosy.

Adenosine deaminase (ADA) activity was studied in serum and peripheral blood lymphocytes of leprosy patients and healthy controls. Serum ADA levels were found to be elevated in tuberculoid as well as lepromatous cases compared to control subjects. Serum ADA activity was significantly higher in tuberculoid cases than in the lepromatous group. Lymphocyte adenosine deaminase activity showed a similar trend. These results suggest that, since the overall activity of the enzyme is not deficient in leprosy, the cellular immune abberation seen in the different types of leprosy may be due to abnormal proliferation of different subsets of lymphocytes in response to M. leprae.

Adenosine Deaminase↗