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Biomedical subjects

Surjit Singh

Publications and source records attributed to Surjit Singh.

At least 37 records · Page 2Linked to original sources
PubMed2003

Reducing acute poisoning in developing countries--options for restricting the availability of pesticides.

Hundreds of thousands of people are dying around the world each year from the effects of the use, or misuse, of pesticides. This paper reviews the different options to reduce availability of the most hazardous chemicals, focusing on issues in developing countries. Emphasis is placed on the fatal poisoning cases and hence the focus on self-harm cases. Overall, it is argued here that restricting access to the most hazardous pesticides would be of paramount importance to reduce the number of severe acute poisoning cases and case-fatalities and would provide greater opportunities for preventive programmes to act effectively. The aim should be to achieve an almost immediate phasing out of the WHO Classes I and II pesticides through national policies and enforcement. These short-term aims will have to be supported by medium- and long-term objectives focusing on the substitution of pesticides with safe and cost-effective alternatives, possibly guided by the establishment of a Minimum Pesticide List, and the development of future agricultural practices where pesticide usage is reduced to an absolute minimum. Underlying factors that make individuals at risk for self-harm include domestic problems, alcohol or drug addiction, emotional distress, depression, physical illness, social isolation or financial hardship. These should be addressed through preventive health programmes and community development efforts.

Acute Disease↗
PubMed2003

Comparison of serum nitric oxide levels in active juvenile rheumatoid arthritis with those of patients in remission.

Thirty-four children with juvenile rheumatoid arthritis were studied for surrogate markers of increased nitric oxide (NO) production by spectrophotometry. Mean levels of reactive nitrogen intermediates and citrulline levels were higher in patients with active disease than in children with partial and complete remission. A significant correlation was also found between clinical indices of inflammation, erythrocyte sedimentation rate, modified Childhood Health Assessment Questionnaire scores, and surrogate markers of increased NO production.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Topical delivery of 5-fluorouracil and 6-mercaptopurine by their alkylcarbonyloxymethyl prodrugs from water: vehicle effects on design of prodrugs.

PURPOSE: To determine whether the fluxes through hairless mouse skin for three homologous series of prodrugs of 5-fluorouracil (5-FU, 1) and 6-mercaptopurine (6-MP, 2) from saturated aqueous suspensions show dependencies on aqueous (SAQ) and isopropyl myristate (SIPM) solubilities similar to those shown by the identical compounds delivered from IPM. METHODS: Flux through hairless mouse skin from water (JMAQ) and solubility data were measured for a homologous series of six 3-alkylcarbonyloxymethyl (ACOM) prodrugs of 5-FU (3-ACOM-5-FU), and five 6-ACOM-6-MP prodrugs, then combined with literature data for five bis-6,9-ACOM-6-MP prodrugs to give a data base. Multiple linear regression using SPSS 7.5 was performed on log SIPM, log SAQ, molecular weight and log JMAQ data to determine the best fit coefficients to the transformed Potts-Guy equation: log JMAQ = x + y log SIPM + (1 - y) log SAQ + z MW. Permeability coefficients (PMAQ) were calculated from JMAQ/SAQ. RESULTS: The best fit coefficients for the flux from AQ(JMAQ) were x = -1.497, y = 0.660 and z = -0.00469 (r2 = 0.765) with an average error of prediction equal to 0.193 log units. The best fit coefficients for the flux from IPM (JMIPM) were x = -0.557, y = 0.536 and z = -0.00261 (r2 = 0.941) with an average error of prediction equal to 0.109 log units. For all three series, log PMAQ increased whereas log PMIPM decreased with increasing alkyl chain lengths in the promoiety and with decreasing solubility parameter values. CONCLUSIONS: The transformed Potts-Guy equation can be used to predict JMAQ but with less certainty than JMIPM. SIPM and SAQ have consistently been shown to have a positive influence on JMIPM, and now on JMAQ, with a balance between the two solubilities being obviously important. The previous observation that log PMAQ increased with lipophilicity is an artifact of normalizing JMAQ by SAQ.

Administration, Cutaneous↗
PubMed2003

Anti-streptolysin O titers in normal healthy children of 5-15 years.

Antistreptolysin O (ASO) levels vary with age group of the study population and geographical locations. The present study was undertaken to determine the upper limit of normal of ASO in 200 normal children of 5-15 years of age with no history of recent sore throat infection. The standard tube dilution method (WHO) was used for estimating ASO titers. It was found that 239 IU was the upper limit of normal in the study population, which can be considered as the baseline ASO titer. This can provide useful guidelines for physicians in the interpretation of elevated ASO titers in cases of suspected acute rheumatic fever.

Adolescent↗
PubMed2002

Pesticide poisoning in the developing world--a minimum pesticides list.

In parts of the developing world, pesticide poisoning causes more deaths than infectious diseases. Use of pesticides is poorly regulated and often dangerous; their easy availability also makes them a popular method of self-harm. In 1985, the UN Food and Agriculture Organisation (FAO) produced a voluntary code of conduct for the pesticide industry in an attempt to limit the harmful effects of pesticides. Unfortunately, a lack of adequate government resources in the developing world makes this code ineffective, and thousands of deaths continue today. WHO has recommended that access to highly toxic pesticides be restricted--where this has been done, suicide rates have fallen. Since an Essential Drugs List was established in 1977, use of a few essential drugs has rationalised drug use in many regions. An analogous Minimum Pesticides List would identify a restricted number of less dangerous pesticides to do specific tasks within an integrated pest management system. Use of safer pesticides should result in fewer deaths, just as the change from barbiturates to benzodiazepines has reduced the number of deaths from pharmaceutical self-poisoning.

Cause of Death↗
PubMed2002

Antitubercular therapy decreases nitric oxide production in HIV/TB coinfected patients.

BACKGROUND: Nitric oxide (NO) production is increased among patients with human immunodeficiency virus (HIV) infection and also those with tuberculosis (TB). In this study we sought to determine if there was increased NO production among patients with HIV/TB coinfection and the effect of four weeks chemotherapy on this level. PATIENTS AND METHODS: 19 patients with HIV/TB coinfection were studied. They were treated with standard four drug antitubercular therapy and sampled at baseline and four weeks. 20 patients with HIV infection but no opportunistic infections were disease controls and 20 individuals as healthy controls. Nitrite and citrulline, surrogate markers for NO, were measured it spectrophotometrically. RESULTS: Mean age of HIV/TB patients was 28.4+6.8 years and CD4 count was 116+36.6/mm3. Mean nitrite level among HIV/TB coinfected was 207.6+48.8 nmol/ml. This was significantly higher than 99.7+26.5 nmol/ml, the value for HIV infected without opportunistic infections and 46.4+16.2 nmol/ml, the value for healthy controls (p value <0.01). Level of HIV/TB coinfected declined to 144.5+ 34.4 nmol/ml at four weeks of therapy (p value < 0.05). Mean citrulline among HIV/TB coinfected was 1446.8+468.8 nmol/ml. This was significantly higher than 880.8+ 434.8 nmol/ml, the value for HIV infected without opportunistic infections and 486.6+212.5 nmol/ml, the value for healthy controls (p value <0.01). Levels of HIV/TB infected declined to 1116.2+388.6 nmol/ml at four weeks of therapy (p value <0.05). CONCLUSION: NO production is elevated among patients with HIV infection, especially so among HIV/TB coinfected, but declines significantly following 4 weeks of antitubercular therapy.

Adult↗
PubMed2002

Evidence for a spontaneous C1840-T mutation in the RYR1 gene after DNA fingerprinting in a malignant hyperthermia susceptible family.

Malignant hyperthermia (MH) is a potentially lethal inherited pharmacogenetic syndrome due to a dysfunction of the intracellular calcium regulation of skeletal muscle following administration of volatile anaesthetics and depolarizing muscle relaxants. The ryanodine receptor of skeletal muscle (RYR1), which is an intracellular calcium release channel, has been proposed to be a candidate structure for the MH defect. In some families with a history of MH a C1840-T nucleotide exchange has been found in the RYR1 gene which cosegregates with the MH susceptible phenotype. Sixteen individuals (5 males and 11 females; age 8-68 years, 7 MH susceptible, 9 MH non-susceptible) of a family with a history of MH were screened for the C1840-T mutation in the RYR1 gene using standard methods. DNA fingerprinting was performed in order to verify the kinship. MH susceptibility was determined using the standard in vitro contracture test with halothane and caffeine. The present article describes a German MH pedigree carrying a spontaneous C1840-T mutation. The mutation was detected in one individual of the third generation. This person was classified as MH susceptible according to the in vitro contracture test protocol. None of the other family members (6 MH susceptible and 9 MH non-susceptible persons), including the parents of the child carrying the mutation, presented the C to T nucleotide exchange at position 1840.This novel observation clearly demonstrates that only the detection of the C1840-T mutation may lead to the diagnosis of MH susceptibility, but missing the mutation does not justify diagnosing a patient as non-susceptible within a single pedigree.

Adolescent↗
PubMed2002

Severe Henoch-Schönlein nephritis: resolution with azathioprine and steroids.

AIM: The aim of this study was to assess the efficacy of long-term azathioprine and steroids for treatment of severe nephritis in children with Henoch-Schönlein purpura (HSP). METHODS: Analysis of case records of children with HSP followed up for a mean duration of 4.7 years (range 6 months-6.5 years) was performed. All underwent clinical status evaluation followed by percutaneous kidney biopsies. Renal histological changes were graded according to the International Study of Kidney Disease in Childhood (ISKDC) classification. Nine children with severe nephritis (grades III and IV) received steroids (mean duration 12.1 months) and long-term azathioprine (mean duration 14.7 months), while two children received steroids alone. RESULTS: All nine children in the former category showed sustained clinical and biochemical remission, while the two children in the latter category did not. CONCLUSION: Severe nephritis seen in association with HSP can be effectively treated with a combination of azathioprine and steroids.

Azathioprine↗
PubMed2002

Clinical approach to vasculitides.

The term vasculitis refers to inflammation and necrosis of blood vessels. The vasculitides are best classified according to the size of the involved vessels into large, medium and small vessel vasculitis. As a group the disorders are not uncommon even in children but the diagnosis of a given condition can often get delayed, or ever be entirely missed, because of multi-system involvement and the consequent protean clinical manifestations. Kawasaki Disease and Henoch-Schonlein Purpura are the commonest vasculitides seen in children. Early diagnosis and prompt treatment can go a long way in decreasing the morbidity and mortality associated with these disorders.

Child↗
PubMed2002

Proximal muscle weakness--an unusual presentation of celiac disease.

The identification of the etiology of metabolic bone disease that leads to myopathy is important as this type of muscle weakness often responds fully to treatment. We present the case history of an 11-year-old girl with celiac disease who had rickets masquerading as muscle weakness and bone pains.

Biopsy↗
PubMed2002

The natural course of nonsuppurative Calmette-Guérin bacillus lymphadenitis.

In a tertiary level hospital in North India, we studied the outcome of infants with nonsuppurative Calmette-Guérin bacillus (BCG) lymphadenitis managed conservatively. Twenty-three infants with nonsuppurative BCG lymphadenitis diagnosed on the basis of clinical presentation, evidence of granulomatous inflammation and demonstration of acid fast bacilli in the aspirated material were followed prospectively without being offered specific antitubercular drug therapy. Twenty patients were available for final analysis; three were lost to follow-up. Seventeen (85%) had spontaneous regression of BCG lymphadenitis without progression and drainage. The mean time to resolution was 9.1 months. Three (15%) patients developed suppuration and drainage, but even these children had uneventful healing on conservative management only. Nonsuppurative BCG lymphadenitis follows a benign course in most individuals. Most of the cases regress spontaneously with conservative management.

BCG Vaccine↗