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M D Gupte

Publications and source records attributed to M D Gupte.

At least 37 records · Page 2Linked to original sources
PubMed1997

Isolation of wild Xanthomonas strains from agricultural produce, their characterization and potential related to polysaccharide production.

One hundred fifty wild strains of Xanthomonas were isolated on five selective and nonselective media. The comparative effectivity of the five media has been discussed. Fifteen polysaccharide-producing strains shortlisted were identified up to species level. These were studied for polysaccharide production in shake flasks using YM media. The highest final yield of 21.3 g/L of the amount of carbon source supplied has been obtained in the optimum medium in shake-flask experiments from Xanthomonas campestris (ICa-125 strain isolated from cabbage. Rheological properties of the exocellular polysaccharide (EPS) have been compared with standard xanthan. EPS from X. campestris ICa-125 was found to be superior with respect to heat stability and effect of electrolytes as compared to standard xanthan.

Bacteriological Techniques↗
PubMed1997

Regional lymphadenitis following antileprosy vaccine BCG with killed Mycobacterium leprae.

Phase-II and extended Phase-II studies were conducted in three different sets of the population in Thiruthani Taluk, Chengalpattu District, South India, involving BCG and killed Mycobacterium leprae (KML) combination vaccines to ascertain the acceptability of the vaccines. In the Phase-II study, 997 healthy volunteers were vaccinated on individual randomization with one of the vaccines arms: BCG 0.1 mg + 6 x 10(8) KML, BCG 0.1 mg + 5 x 10(7) KML, BCG 0.1 mg + 5 x 10(6) KML, BCG, 0.1 mg or normal saline. Blood samples were taken and the serum was tested for antibody levels against phenolic glycolipid-I (PGL-I) and the 35-kDa protein of M. leprae. In this study, we observed regional suppurative adenitis in 6% (6 out of 100), 3% (3 out of 100), and 3% (3 out of 100) of the vaccinees in the BCG 0.1 mg + 6 x 10(8) KML, BCG 0.1 mg + 5 x 10(7) KML, and BCG 0.1 mg + 5 x 10(6) KML vaccine arms, respectively, in the 13-70 year age group. Earlier BCG scar status, skin-test reactions to lepromin-A, Rees' MLSA, and serum antibody levels against PGL-I and the 35-kDa protein did not help to identify the group at risk of developing suppurative adenitis. Suppurative adenitis appears to have a different relationship between the age of the subject and the dose of the vaccine. In order to overcome the problem of regional suppurative adenitis and to know the mechanism involved, an extended Phase-II study was conducted in similar groups of the population by reducing the BCG and KML doses, i.e., with BCG 0.05 mg + 6 x 10(8) KML, BCG 0.05 mg + 5 x 10(7) KML, and BCG 0.01 mg + 5 x 10(7) KML. Biopsy specimens were collected from lymph nodes of the suppurative adenitis cases and were subjected for culture and histopathological examination. The observations showed that regional suppurative adenitis could be reduced to 1% in the BCG 0.05 + 6 x 10(8) KML group, 0.5% in the BCG 0.05 + 5 x 10(7) KML group, and 0.5% in the BCG 0.01 + 5 x 10(7) KML group. This phenomenon of suppurative adenitis appears to be related to the total dose of mycobacterial antigens. Suppurative adenitis was seen by weeks 18 and 20 post-vaccination in the latter two lower doses; whereas it was seen by week 8 in the higher dose of the combination vaccines. No case of suppurative adenitis was observed in the BCG 0.1 mg group. Culture and histopathology ruled out the possibilities of progressive BCG infection and superadded infection. Considering the above results, BCG 0.05 mg + 6 x 10(8) KML was acceptable for a large-scale vaccine trial in South India.

Adolescent↗
PubMed1997

Trends in leprosy case detection rates.

BACKGROUND: A systematic review of the trends in leprosy incidence is lacking. The question of whether leprosy transmission has declined remains, therefore, unanswered. This study investigates trends in new case detection rates (NCDRs) in selected leprosy-endemic areas from different continents. METHODS: A literature search using specific inclusion criteria was performed. Average annual rates of change in NCDRs were obtained by exponential curve fitting. The variation in trends within individual areas was investigated using direct and indirect information on leprosy control activities. RESULTS: This review covers 16 areas in the Pacific, Asia, Africa and Latin America. For 10 out of the 16 areas, the trend was seen to be declining consistently over the last 10 years or longer. Near stabilization or stabilization after decline was observed for two areas. For three areas, interpretation of recent NCDRs was difficult due to changes in control, but two of them showed a decline over the study period. A consistently increasing trend was observed over the last 20 years in the one remaining area. The observed downward trends could not be attributed to reduced control activities or changed diagnostic criteria. A general acceleration of downward trends in the NCDR after the introduction of multidrug therapy (MDT) has not so far occurred. CONCLUSION: Our main conclusion is that despite many differences between the studies and study areas, the review demonstrates a considerable tendency of downward NCDR trends. Lack of information and changing control conditions necessitate caution in interpreting NCDR trends in individual areas. A general impact of MDT on NCDR trends is so far not visible. The coming years will be crucial for MDT-based control to prove its ability to reduce leprosy incidence.

Adult↗
PubMed1993

Sensitization potential and reactogenicity of varying doses of BCG plus killed Mycobacterium leprae: an extended study.

This study is an extension of a previous study on an antileprosy combination vaccine of BCG plus killed Mycobacterium leprae (KML) regarding its sensitization potential and reactogenicity. The study was extended to see if by reducing the dose of BCG in the combination vaccine the incidence of suppurative adenitis could be reduced without a significant reduction in the level of postvaccination skin-test responses. The study included 860 individuals, and three preparations of the combination vaccine [BCG 0.05 mg + 6 x 10(8) KML (I), BCG 0.05 mg + 5 x 10(7) KML (II), BCG 0.01 mg + 5 x 10(7) KML (III)] along with normal saline (i.v.) were used. Each individual received one of these four preparations by random allocation. They were also tested with Rees' M. leprae soluble antigen (MLSA) and lepromin A 12 weeks after vaccination. Reactions to the MLSA were measured after 48 hr; reactions to lepromin A after 48 hr and 3 weeks. The character and size of the local response at the vaccination site were recorded at the third, eighth, and 15th week postvaccination. The results of the study showed that by halving the dose of BCG in the combination vaccine BCG plus 6 x 10(8) KML a) the incidence of suppurative regional adenitis was reduced significantly, b) there was no significant change in the post-vaccination response at 12 weeks as measured by Rees' MLSA and lepromin A, and c) the evolution of the vaccination lesion was somewhat prolonged. This dose was found satisfactory for use in a comparative antileprosy vaccine trial in South India.

Adolescent↗
PubMed1992

Sensitization potential and reactogenicity of BCG with and without various doses of killed Mycobacterium leprae.

A study was conducted in 997 individuals in two villages in south India to find the acceptability and sensitizing effect of the antileprosy combination vaccine of BCG plus killed Mycobacterium leprae (KML). Three preparations of the combination, BCG 0.1 mg + 6 x 10(8) KML (I), BCG 0.1 mg + 5 x 10(7) KML (II), and BCG 0.1 mg + 5 x 10(6) KML (III), along with BCG 0.1 mg (IV), and normal saline (V), were used in the study. Each individual received one of the above five preparations by random allocation. They were also tested with Rees' M. leprae soluble skin-test antigen (MLSA) and lepromin-A, both at intake and 12 weeks after vaccination. Reactions to Rees' MLSA were measured after 48 hr; those to lepromin-A after 48 hr and 3 weeks. The character and size of the local response at the vaccination site were recorded at 3, 8, 12, 15, and 27 weeks after vaccination. The mean sizes of postvaccination sensitization to both Rees' MLSA and lepromin-A in the vaccine groups were significantly larger than those in the normal saline group, clearly demonstrating the ability of the vaccines to induce sensitization as measured by responses to the two skin tests. The sensitizing effect was the highest following vaccination with vaccine I. It was not significantly different for vaccines II, III, and IV, although, generally, a dose-response effect was observed. The sensitizing effect attributable to the vaccine was more clearly seen in children than in adults. The above conclusions were the same irrespective of which results were considered, reactions to Rees' MLSA or Fernandez or Mitsuda reactions to lepromin-A. A significant finding of the study was that at intake the Mitsuda reactions provided a measure of sensitizing effect due to vaccine. The healing of vaccination lesions was uneventful. In more than 90% of vaccinated individuals, the lesions had healed by the 12th week in vaccine groups II, III, and IV, and by the 15th week in vaccine group I. The results showed that vaccination with BCG or combination vaccines was equally safe in individuals with or without previous BCG scars. Thirteen persons, aged 10 years or older, developed suppurative lymphadenitis around the 8th week (7 in vaccine group I, 3 each in vaccine groups II and III). However, healing was prompt after drainage in these individuals.

Adolescent↗
PubMed1992

Effect of skin test with M. leprae soluble antigen on reaction to a subsequent test with the same antigen.

Soluble skin-test antigens (STA), produced from armadillo-derived Mycobacterium leprae by Drs. Rees and Convit, were expected to meet the long-felt need of a test for leprosy infection and also to serve as tests for measuring postvaccination sensitization induced by vaccine preparations against leprosy. The present paper reports results from two studies examining the influence, if any, of skin testing with Rees' STA on reaction to a subsequent test with the same antigen. In the first study, 2168 persons from households of leprosy patients and from neighboring households were skin tested with Rees' STA twice at an interval of 6 months. In the second study, 1700 persons, free from leprosy, received either Rees' STA or normal saline by random allocation. A random subset of 850 persons was tested with Rees' STA after 3 months. The remaining 850 persons were tested with Rees' STA after 6 months. In addition, 242 leprosy patients were given Rees' STA or normal saline by random allocation, and all of these patients were tested with Rees' STA after 6 months. The results of the two studies showed that among persons reacting with a small size of reaction to Rees' STA, the size of the reaction to the repeat test was significantly larger. However, from the results of the second study, which included a control group, it was clearly seen that the quantum of boosting or sensitizing effect of the first test as well as that of new sensitization was small over a period of 3-6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Experiences with Mycobacterium leprae soluble antigens in a leprosy endemic population.

Rees and Convit antigens prepared from armadillo-derived Mycobacterium leprae were used for skin testing in two leprosy endemic villages to understand their use in the epidemiology of leprosy. In all, 2602 individuals comprising 202 patients with leprosy detected in a prevalence survey, 476 household contacts and 1924 persons residing in non-case households were tested with two antigens. There was a strong and positive correlation (r = 0.85) between reactions to the Rees and Convit antigens. The distribution of reactions was bimodal and considering reactions of 12 mm or more as 'positive', the positivity rate steeply increased with the increase in age. However, the distributions of reactions to these antigens in patients with leprosy, their household contacts and persons living in non-case households were very similar. These results indicate that Rees and Convit antigens are not useful in the identification of M. leprae infection or in the confirmation of leprosy diagnosis in a leprosy endemic population with a high prevalence of nonspecific sensitivity.

Adolescent↗
PubMed1988

Reliability of direct skin smear microscopy in leprosy.

Skin smear direct microscopy is an important tool for diagnosis of leprosy. The study was planned to understand the reproducibility of skin smear reading by a trained technician. Skin smears were collected from known patients of leprosy from the field area. They were stained for acid fast bacilli following the standard cold staining procedure and were read following the Ridley scale. A sample of smears was re-examined on two occasions by the same technician, following blind procedure. There was a systematic under reading on the second occasion, which was attributed to the defective storage of the slides. However, the agreement between second and third examinations was very good (Concordance 81.34%, Kappa 0.74). The finding was confirmed on a repeat examination. It can be concluded that the Direct Skin Smear Microscopy is a reliable and reproducible technique under experimental conditions.

Humans↗
PubMed1983

Investigation report of an epidemic of typhoid fever.

An explosive common-source epidemic of typhoid fever, probably the world's biggest, occurred in Sangli Town (Maharashtra State), India, between December 1975 and February 1976 when, with the incidence rate of 6.59% over this 12-week period, probably more than 9000 cases occurred in a population of about 135 000. Faecal contamination of municipal water supply, which was receiving unsatisfactory and inadequate chlorine treatment, was responsible for the epidemic. Contamination at suitable intervals resulted in a heavy build-up of S. typhi in the population. Massive central contamination of the ill-maintained municipal water-supply system with faecally-contaminated waste-water from a population of about 37 000, in which there were thought to be over 250 typhoid cases, ultimately resulted in the explosive epidemic. The episode underlines the importance of proper maintenance of water supply and excreta disposal systems.

Adolescent↗
PubMed1980

HLA-linked control of susceptibility to tuberculoid leprosy and association with HLA-DR types.

In an attempt to confirm an HLA-linked effect on the course of Mycobacterium leprae infection observed in families from Surinam (South America), we conducted a similar family study in an endemic area in India. We observed a significant (P less than .05) excess of identical HLA-GLO haplotypes only from healthy parents among siblings affected with tuberculoid leprosy. Compared with healthy controls, unrelated patients with tuberculoid leprosy (n = 15) showed a significant heterogeneity at the HLA-DR locus (P less than .05). This heterogeneity was caused by an increased frequency of HLA-DRw2 (.93 versus .53, P less than .05), particularly of DRw2 homozygotes (.53 versus .11, P less than .005), and a decreased frequency of HLA-DRw6 (.07 versus .58, P less than .005). We observed a significant (P = .03) preferential segregation of DRw2 from DRw2 heterozygous parents not affected with tuberculoid leprosy to children with the tuberculoid type of the disease. These data confirm an HLA-linked control of susceptibility to tuberculoid leprosy only, and suggest a recessive inheritance of this trait for which HLA-Drw2 appears to be a genetic marker.

Female↗
PubMed1979

Concanavalin A induced suppressor activity in human leprosy.

Peripheral blood lymphocytes from nine normal subjects and 40 patients with leprosy were pretreated in vitro with Concanavalin A (Con A). Cells from normal subjects pretreated for 24 hours showed consistent and effective generation of suppressive activity which inhibited mitogen induced transformation of autologous lymphocytes. Prolongation of Con A pretreatment to 40 hours resulted in maximal suppressive activity. Tuberculoid leprosy patients had lymphocytes in their blood which on 24 hour pretreatment with Con A exerted suppressive effects markedly greater than the maximal suppression noted with 40 hour pretreated normal lymphocytes. In contrast, untreated patients with polar lepromatous leprosy showed a decrease in suppressive activity which could not be altered by prolongation of Con A pretreatment: the loss of suppressive activity noted in this form of leprosy was restored during erythema nodosum leprosum.

Concanavalin A↗
PubMed1979

Dapsone treatment and deformities. A retrospective study.

Gandhi Memorial Leprosy Foundation conducted a study from 1963-72. Records of 2608 patients pertaining to type of leprosy, year of detection and registration, involvement of nerves, treatment, reactions, deformities, were available for a retrospective study. Patients having problems like neuritis and deformities and of the types lepromatous and borderline were the ones who tended to be regular clinic attenders. Lepromatous and Borderline and Polyneuritic types and N3 group were prone to develop deformities. There seemed to be association between reaction and causation of deformities. Because of the neurotoxic effect and ability to concentrate in the affected nerves, dapsone might enhance the risk of deformities. Low deformity rates in N1 and N2 types of nerve involvement reaffirmed the necessity of early diagnosis of leprosy.

Adult↗
PubMedDate not supplied

Comparative leprosy vaccine trial in south India.

This report provides results from a controlled, double blind, randomized, prophylactic leprosy vaccine trial conducted in South India. Four vaccines, viz BCG, BCG+ killed M. leprae, M.w and ICRC were studied in this trial in comparison with normal saline placebo. From about 3,00,000 people, 2,16,000 were found eligible for vaccination and among them, 1,71,400 volunteered to participate in the study. Intake for the study was completed in two and a half years from January 1991. There was no instance of serious toxicity or side effects subsequent to vaccination for which premature decoding was required. All the vaccine candidates were safe for human use. Decoding was done after the completion of the second resurvey in December 1998. Results for vaccine efficacy are based on examination of more than 70% of the original "vaccinated" cohort population, in both the first and the second resurveys. It was possible to assess the overall protective efficacy of the candidate vaccines against leprosy as such. Observed incidence rates were not sufficiently high to ascertain the protective efficacy of the candidate vaccines against progressive and serious forms of leprosy. BCG+ killed M. leprae provided 64% protection (CI 50.4-73.9), ICRC provided 65.5% protection (CI 48.0-77.0), M.w gave 25.7% protection (CI 1.9-43.8) and BCG gave 34.1% protection (CI 13.5-49.8). Protection observed with the ICRC vaccine and the combination vaccine (BCG+ killed M. leprae) meets the requirement of public health utility and these vaccines deserve further consideration for their ultimate applicability in leprosy prevention.

Adolescent↗
PubMedDate not supplied

Quality control tests for vaccines in leprosy vaccine trial, Avadi.

All the vaccines supplied for the large scale comparative leprosy vaccine trial of ICRC bacilli, M.w, BCG plus killed M. leprae (candidate vaccines), BCG and normal saline (control arms) at CJIL Field Unit, Chennai were tested for quality control by the suppliers following the procedures laid down in the WHO protocol for killed M. leprae. Quality control for BCG was carried out at BCG vaccine laboratory as per protocol. Toxicity and sterility tests were done on all the vaccine batches/lots received. As part of the quality control, bacterial count, and protein estimation were also done. Studies showed that the bacterial content and protein concentration were comparable with the original preparations. Vaccines were free from micro-organisms, toxic materials and safe for human use. Thus the quality of all vaccine preparations was satisfactory.

BCG Vaccine↗