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Biomedical subjects

S Balakrishnan

Publications and source records attributed to S Balakrishnan.

At least 37 records · Page 2Linked to original sources
PubMed1991

Serum zinc/copper ratio in subtypes of leprosy and effect of oral zinc therapy on reactional states.

Serum zinc and copper levels and zinc/copper ratios were studied in 86 healthy controls, 45 cases of borderline tuberculoid (BT), 31 cases of borderline lepromatous (BL), 117 cases of lepromatous (LL) leprosy patients, 16 cases with severe erythema nodosum leprosum (ENL) reaction, and 16 cases with ENL reaction receiving oral zinc therapy. A significant reduction in serum zinc levels was noticed in all types of leprosy, the maximum decrease being seen in cases with ENL reaction. Conversely, the copper levels were significantly increased from BT to LL cases with ENL reaction in a progressive manner. A very good negative correlation (r = -0.998) was noticed between mean serum zinc and copper levels from healthy controls to active LL cases with ENL reaction. After oral zinc therapy, the serum zinc levels were significantly increased in all of the 16 LL patients with ENL reaction. In contrast, the copper levels were not decreased, indicating that oral zinc therapy can restore normal zinc levels in leprosy patients but is unable to reduce the increased copper levels.

Administration, Oral↗
PubMed1990

Reye and Reye-like syndromes: results of a pilot study in Peninsular Malaya, 1986.

A pilot epidemiologic study of all cases of Reye and Reye-like syndromes was undertaken at 8 representative major hospitals in Peninsular Malaya from January 1st to December 31st 1986. The cases were classified as definitive Reye's syndrome, clinical Reye's syndrome and encephalo-hepatopathies. Less than 50% of cases reviewed fulfilled the National Center for Disease Control criteria for clinical Reye's syndrome. Causes of Reye-like syndromes/encephalo-hepatopathies included fulminant hepatitis, Japanese B encephalitis, dengue, septicaemia, and complex febrile fits. It was not possible to differentiate clinical Reye's syndrome from the other encephalo-hepatopathies by either the clinical features (except for jaundice) or biochemical parameters. Liver biopsy is necessary for a definitive diagnosis of Reye's syndrome in Malaysia, because of the high prevalence of Reye-like diseases. The mortality rate in the 2 groups of patients is similar. Ingestion of salicylates was not found to be significantly associated with Reye and Reye-like syndromes in this study.

Diagnosis, Differential↗
PubMed1989

Hyperbilirubinaemia and erythrocytic glucose 6 phosphate dehydrogenase deficiency in Malaysian children.

Cord blood from 8,975 babies delivered in Hospital Sultanah Aminah Johor Bahru over a period of eight months (1st August 1985 to 31st March 1986) were screened for G6PD deficiency. The overall incidence was 4.5% in Chinese, 3.5% in Malays and 1.5% in Indian babies. One hundred of these babies were observed in the nursery for seven days and their daily serum bilirubin recorded. The serum bilirubin peaked at 96 hours to a value of 12mg%. None of the babies in the nursery developed a serum bilirubin level of more than 15mg%. Six of the babies with G6PD deficiency that were sent home were readmitted with hyperbilirubinaemia that needed exchange transfusion.

Asian People↗
PubMed1989

Sub clinical infection and the relative risk of developing leprosy: a statistical approach.

Subclinical infection in contacts of leprosy patients was identified by FLA-ABS test and Serum Antibody Competition Test (SACT). The risk of developing leprosy and the confidence intervals were worked out. The importance of expressing the risk ratio and confidence interval of the tests is brought out. This method is a useful adjunct to the routine statistical methods in epidemiological studies.

Antibodies, Monoclonal↗
PubMed1989

Investigations into the haemolytic effects of dapsone therapy in leprosy patients.

Investigations into the haemolytic effects of dapsone therapy were carried out in forty four leprosy patients admitted to the Sacred Heart Leprosy Centre, Kumbakonam. They received weight based dapsone dosages varying from 1.3-3.3 mg/kg body weight. Blood levels and urinary Dapsone/creatinine ratio were assessed at 1 day, 7 days and 30 days of Dapsone treatment. At the same points of time, haematological observations were also carried out. Serum bilirubin as well as blood mathaemoglobin were also examined. The findings showed a reduction in Hb levels at 30 days observation in a good proportion of cases on 100 mg. In one case (child) weighing 15 kg and receiving 50 mg dapsone increased mathaemoglobin was observed. It is suggested that dapsone dosage be regulated to body weight and preferably not to exceed 1.5 mg/kg body weight.

Adolescent↗
PubMed1988

Influence of acetylator phenotype of the leprosy patient on the emergence of dapsone resistant leprosy.

The half time of disappearance of dapsone and monoacetyl dapsone and the acetylator phenotype of the leprosy patients who harboured dapsone sensitive and dapsone resistant M. leprae was assessed in 27 subjects. Sixteen patients were rapid acetylators, five were slow and six were intermediate acetylators. The mean T 1 1/2 lives of dapsone (30.26 +/- 11.0) and monoacetyl dapsone (31.11 +/- 12.0) were also studied in the above patients. The percentage of different acetylators in both resistant and sensitive groups were similar showing no correlation between the emergence of drug resistance and the phenotype of the patient. The mean time of disappearance of DDS and MAD in the different acetylators did not show significant difference. The ratios of MAD/DDS in an individual at 3, 6 or 24 hours after the dose were similar. The mean T 1 1/2 lives of DDS and MAD in resistant and sensitive patients also showed no difference. Neither T 1 1/2 lives of DDS or MAD nor the acetylator phenotype seem to influence the emergence of dapsone resistance.

Acetylation↗
PubMed1988

Microbiological assay versus spectrophotometry for determination of rifampicin in urine.

A comparative study on the microbiological and spectrophotometric methods for estimation of rifampicin in urine was carried out in 15 individuals. The urinary levels of rifampicin were determined on 2nd, 8th and 15th days at 3 hour, 6 hour and 24 hour samples by the above methods after administration of 600 mg rifampicin. The results suggest that the microbiological assay is more sensitive than spectrophotometric method. The difference was highly significant in all the cases by paired t-test. Incidentally it was also noticed that urinary excretion of rifampicin was comparatively more on 15th day.

Humans↗
PubMed1988

Certain aspects of dapsone metabolism in leprosy patients as studied by high performance liquid chromatography (HPLC) and qualitative screening tests.

Dapsone (DDS) in urine of 250 leprosy patients collected on surprise visits were screened by simple paper spot, tile tests and sensitive Enzyme linked immunosorbent assay (ELISA) and Haemagglutination inhibition (HI) tests. The urinary DDS concentration as well as DDS/C ratios were also studied. Simultaneously, 50 microliter of blood was collected from each of these patients and its dapsone content was estimated by HPLC. Urine samples with means of 25 to 30 micrograms/ml DDS and 55-64 micrograms/mg DDS/C ratios were found to give positive tests by any of the above screening procedures, while their mean blood DDS concentration was found to be 0.91 microgram/ml. The corresponding values for those specimens giving negative tests were 3.8 to 5.7 micrograms DDS per ml and 9 to 13 micrograms/mg DDS/C ratio. The blood DDS concentration in this group was ranging from 0.16 to 0.18 micrograms/ml. The findings are discussed in relation to their metabolic significance and their application in a leprosy control programme.

Chromatography, High Pressure Liquid↗
PubMed1983

Studies on sulphone resistant strains of M. leprae in field and institutionalized cases of leprosy.

The proportions of dapsone resistant strains of M. leprae in cases from the field and in patient institutionalized for treatment were compared. Identification of dapsone resistance was done by mouse-foot-pad experiments carried out in the Laboratory in Central Leprosy Teaching and Research Institute, Chengalpattu. A higher percentage of resistance was detected among institutional patients as compared to field cases. The distribution of M.I. ranges of M. leprae in dapsone resistant subjects was not different from that in dapsone sensitive cases.

Animals↗
PubMed1983

Prevalence survey of secondary dapsone resistance in leprosy in Kancheepuram and Tiruvannamalai control units of Tamil Nadu.

A field survey was designed and carried out in parts of Kancheepuram and Tiruvannamalai Leprosy Control Units in Tamilnadu (population 418,000) with the objective of finding out the prevalence of secondary dapsone resistance among 790 lepromatous (LL and BL) cases, who formed the patient population at risk based on certain treatment criteria. Using the mouse footpad experiment, 3 resistant cases were identified in Kancheepuram Unit (prevalence rate of 1.0 per cent) and 11 cases in Tiruvannamalai Unit (prevalence rate of 2.2 per cent). The metabolic status of dapsone was found to be normal in more than 90% of the patients, showing no relationship to occurrence of resistance.

Animals↗
PubMed1983

Mouse foot pad growth of M. leprae in relation to bacteriological index.

A retrospective analysis was made of the mouse foot-pad growth of M. leprae from 35 cases of lepromatous leprosy with B.I. ranging from 1.33 to 4.0 (Dharmendra scale). Of these 35 cases, 6 were found to be harbouring dapsone resistant bacilli and 18 cases sensitive bacilli. In 11 of them there was no growth in the control group of animals. The analysis showed that there was no difference in the mean B.I. between those showing no growth and those showing growth in the 1st, 2nd or 3rd harvest. A minimum B.I. around 1.5 is considered adequate for positive foot-pad takes. Another interesting observation made in the study was that the growth rate in the control group foot-pads was consistently higher in mice receiving dapsone resistant bacilli as compared to those inoculated with bacilli, sensitive to the drug.

Animals↗
PubMed1983

Paper spot test and DDS/creatinine ratios in relation to treatment taken by leprosy patients.

The findings on the positivity of paper spot test and the mean DDS/Cr. ratios in relation to the percentage of treatment taken by 316 leprosy out-patients on 100, 50 or 25 mg/DDS daily are presented. Thirty-three percent of the subjects on 25 mg were found to give negative spot test as against 11-12% in the patient groups on 50 and 100 mgs dose schedules. The mean DDS/Cr. ratios in the spot test negative urine specimens were consistent for all dosage groups and ranged from 7.1-9.6 micrograms/mg. The ratios in the spot test-positive urine specimens, showed, in general, a direct proportion to the percentage of treatment taken particularly, in the 75-100% and 50-75% groups. The significance and implications of the findings are discussed.

Creatinine↗
PubMed1983

Operational study to monitor the regularity of dapsone intake by leprosy out-patients.

319 leprosy patients, attending our Mobile Treatment Unit, were monitored for their regularity of dapsone intake by (1) Physical verification of DDS tablets; and (2) Spot test, in the field. The consistency in regularity of DDS intake by these patients, was monitored at two more occasions at the interval of about two months. Only 36% patients were regular in attending the clinics. On an average one patient would miss about one third of the clinics in a year. The number of patients taking regular treatment increased from 62% (I round) to 79% (in III round). Approximately 10% patients collected DDS tablets from clinic but never ingested them; and 3% to 7% patients removed Dapsone tablets regularly but ingested none of it, as indicated by negative spot tests. The spot test was found to be positive in about 86% patients, and had a very good correlation (98%) with DDS/Cr. ratio. Both the methods of monitoring were found to be operationally very feasible and reliable under field conditions, hence can be used together to monitor the dapsone intake by leprosy patients, in National Leprosy Control Programme.

Adolescent↗
PubMed1983

A comparison of screening tests for dapsone in urine.

The comparative merits and limitations of three qualitative tests for Dapsone screening in urine viz. the 'Spot-Test' using modified Ehrlich's reagent, 'Tile-Test' employing Bratton-Marshall reagents, and the 'Elisa-Test' were assessed with regard to their sensitivity and operational feasibility. Investigations were carried out on a total of 716 urine specimens of which 268 specimens were collected during surprise visits paid to the patients homes. The others were specimens collected from patients at different time intervals following the administration of 25, 50 and 100 mg of dapsone. The findings were evaluated against their corresponding ratios of the urinary concentrations of Dapsone and its diazotisable metabolites to creatinine. A good correlation was found between the three qualitative tests in general and also in relation to the DDS/C ratios. Operational feasibility under field conditions for spot and tile tests are discussed.

Creatinine↗
PubMed1983

Application of "tile reaction" test for screening dapsone in urine.

A modified tile reaction test for monitoring self administration of DDS by leprosy patients is described. 385 Urine samples collected at 24 hours after a single dose and at 24, 48 and 72 hours after daily doses of 25, 50, 100 mg were screened for the presence of DDS by this test and the corresponding DDS/C ratios were studied for comparison. Patients compliance was assessed on 268 urine specimens collected on surprise visits. The feasibility of application of this test in field situations is discussed.

Dapsone↗