Defective interleukin-2 production and interleukin-2 receptor expression in pulmonary tuberculosis.

The evolution of Mycobacterium tuberculosis as an intracellular pathogen has led to a complex relationship between it and its host, the human mononuclear phagocyte. The products of M. tuberculosis-specific T lymphocytes are essential for macrophage activation for intracellular mycobacterial killing. However, dysfunction cell-mediated immune response to infection with M. tuberculosis may contribute to progressive primary infection or reactivation of endogenous foci of mycobacteria. Th1 cells produce IL-2, which is essential for proper cellular immunity. The aim of this study was to identify the variation in IL-2 activity and soluble IL-2 receptor (IL-2 R) in peripheral blood lymphocyte in patients suffering with pulmonary tuberculosis. A significant decrease in IL-2 and IL-2 receptor level was observed in patients with pulmonary tuberculosis when compared to normal controls. Our results suggested that patients with pulmonary tuberculosis had a defect in IL-2 production. Better understanding of these interactions will allow the development of increasingly specific immune-based interventions for prevention and treatment of tuberculosis.

Use of complement receptor 1 (CD35) assay in the diagnosis and prognosis of immune complex mediated glomerulopathies.

Complement Receptor 1 (CR1) is a polymorphic glycoprotein expressed on erythrocytes, leukocytes and glomerular podocytes and has a major role in immune complex processing. In addition, it regulates the complement cascade activation by preventing formation of classical and alternative pathway convertases and by acting as a cofactor for Factor I mediated cleavage of C3. In this study, we have examined the expression of erythrocyte CR1 (E-CR1) and glomerular CR1 (G-CR1) in different kinds of nephropathies using ELISA and immunofluorescence microscopy to understand their role in immune complex (IC) mediated renal diseases. E-CR1 was significantly reduced in all categories of lupus nephritis in comparison to normal subjects and non-IC renal diseases. However, other IC mediated diseases like IgA nephropathy and membranoproliferative glomerulonephritis had normal E-CR1 levels. G-CR1 showed distinct differences between IC and non-IC mediated diseases. G-CR1 was virtually absent in lupus kidneys. In other IC mediated diseases, there was a correlation of G-CR1 expression to the IC and complement fragment deposition. G-CR1 serves as a useful diagnostic marker for IC mediated diseases while E-CR1 is useful as a prognostic marker to monitor the course of disease after the treatment has initiated.

Does moderate alcohol intake protect against coronary heart disease?

There is abundant epidemiological and clinical evidence to show that light-to-moderate drinking is associated with a reduced risk of coronary heart disease (CHD), total and ischemic stroke, and total mortality in middle-aged and elderly men and women. The evidence suggests a J- or U-shaped relationship between alcohol and CHD. Alcohol reduces the risk of coronary heart disease both by inhibiting the formation of atheroma and by decreasing the rate of blood coagulation. It appears that for most conditions, other than cardiovascular diseases and cholelithiasis, moderate alcohol consumption has either none or only an intermediate type of risk as compared with the risk of either abstinence or excessive drinking. It is now fully recognized and accepted that drinking alcohol regularly for years is toxic to almost every tissue of the body. However, most people who choose to drink alcohol have little or no problem limiting their consumption to amounts that do not generally cause serious health or social consequences. Moreover, a given dose of alcohol may affect different people differently. It is, therefore, imperative that a critical evaluation, based on the observations made hitherto, be done of both the harmful and the protective effects of alcohol consumption on various organs/systems of the body. This article reviews epidemiological evidence for the protective effects of alcohol on the cardiovascular system and discusses how alcohol might lower the risk of CHD.

Role of oxygen free radicals in causing endothelial damage in acute myocardial infarction.

OBJECTIVES: This work was done in order to study the oxidant and anti-oxidant status in a disease resulting from endothelial injury. The disease selected for study was acute myocardial infarction. METHODS: Sixty patients of acute myocardial infarction were selected after being diagnosed in accordance to the guidelines laid down by the WHO. Thirty subjects were included as controls. Plasma levels of certain markers of oxidative stress and anti oxidant activity were measured in all the subjects. Malonaldehyde (MDA) and nitrite (NO2) were measured as markers of free radical mediated endothelial injury, and superoxide dismutase (SOD) enzyme as an indicator of antioxidant activity. RESULTS: It was found that the plasma levels of MDA and nitrite were significantly elevated in the patients of acute myocardial infarction compared to the control group (7.29 +/- 3.28 v/s 4.57 +/- 0.63 nmol/ml and 12.85 +/- 8.71 v/s 0.97 +/- 0.25 microM respectively), thereby indicating that oxygen free radicals cause endothelial damage in them. The superoxide dismutase levels were also found to be elevated in these patients (5.57 +/- 1.47 v/s 3.91 +/- 0.66 U/ml). CONCLUSION: These results indicate that acute myocardial infarction is a state of enhanced free radical activity, which causes endothelial damage. The elevated SOD levels may imply that the body attempts to combat this oxidative stress by raising it's level of anti-oxidants.

Apolipoprotein(a) polymorphism and its association with plasma lipoprotein(a) levels: a north Indian study.

Elevated levels of lipoprotein(a) has been regarded as an independent risk factor for coronary, peripheral and cerebral atherosclerosis. The enormous intra-personal variation in the plasma concentration of lipoprotein(a) is almost entirely controlled by the apolipoprotein(a) i.e. gene locus on the chromosome 6q 26-27. The apolipoprotein(a) molecule is highly polymorphic and is known to exist in multiple, genetically determined isoforms. These polymorphisms may be responsible for difference in promoter activity, variable size of apolipoprotein(a) and thereby variation in plasma lipoprotein(a) concentration. We studied the effect of two types of polymorphisms, (i) variation in length of the pentanucleotide repeat in the 5' flanking region starting -1373 bp upstream of AUG codon, and (ii) the Kringle-4 type 2 size polymorphism, on plasma lipoprotein(a) levels in North Indian population. The study group consisted of 88 angiographically assessed male coronary artery disease patients (age range 30-70 years) and 83 age- and sex-matched healthy controls. The pentanucleotide repeat polymorphism was analysed using polymerase chain reaction. In all, 8/11 pentanucleotide repeat isoforms were observed. Using SDS-agarose gel electrophoresis and immunoblotting isoforms having 12-50 Kringle-4 type 2 repeats were detected. Our study indicates a strong association of elevated plasma lipoprotein(a) concentration with coronary artery disease. An inverse correlation was seen between lipoprotein concentration and isoform size for both the pentanucleotide repeat polymorphism and the Kringle-4 type 2 polymorphisms; statistically significant difference (p = 0.001) was, however, observed only for the later.

Macronutrient and energy content of breast milk of mothers delivering prematurely.

The protein, lactose, fat and energy contents of the fore-milk of mother with term (n = 23) and preterm (n = 29) infants were estimated on postpartum days 3, 7, 14 and 21. During the first 4 weeks of lactation, the mean (+/- SD) energy (Kcal/dl), protein (g/dl), fat (g/dl) and lactose (g/dl) levels of the preterm milk were: 56.39 (+/- 7.99), 2.17 (+/- 0.66), 2.30 (+/- 0.48) and 5.78 (+/- 0.99), respectively. The same for term milk were: 59.39 (+/- 8.30), 1.99 (+/- 0.70), 2.48 (+/- 0.53) and 6.24 (+/- 1.08), respectively. The differences in composition between the term and preterm milk were not significant. The composition of breast milk showed changes over the first 3 weeks of lactation. With increasing post-partum days, there was a decline in protein content while fat, lactose and energy contents increased. These trends were more pronounced for preterm milk than term milk. The macronutrient composition and energy estimates of preterm breast milk of Indian mothers in this study may be useful for calculation of nutritional intake by premature neonates fed on expressed breast milk.

Release of superoxide anion from activated mouse peritoneal macrophages during Mycobacterium tuberculosis infection.

Mouse peritoneal macrophage monolayers infected with M. tuberculosis were cultured in RPMI up to 7 days. Release of superoxide was assayed on different days in presence or absence of Phorbol myristate acetate (PMA), a known stimulator of NADPH oxidase which is involved superoxide production. Basal level of superoxide release was significantly higher in M. tuberculosis infected peritoneal mouse macrophages (P < 0.01) as compared to normal mouse macrophages. When normal and tuberculoid macrophage cultures were stimulated with PMA, increased superoxide anion release was observed in both the cultures but the increase of superoxide was significantly higher in normal macrophages as compared to tuberculoid stimulated macrophages. Superoxide release was maximum in 4 day old cultured macrophages and gradually it declined in older cultures by day 7, both in vitro and in vivo. A defective macrophage function in killing of M. tuberculosis bacilli was observed after 4 days of in vitro and in vivo cultures.

Biochemical alterations in macrophages by interaction with immune complexes.

The mouse peritoneal cells (MPS) were stimulated under in vitro and in vivo conditions with different compositions of bovine serum albumin (BSA)-anti BSA immune complexes (IC). The aim was to monitor the biochemical changes that may occur in macrophages and this activation was indicated by an increase in the number and protein content of the cells. The role of these complexes in inducing lysosomal hydrolases release from elicited as well as during an in vitro interaction with ICs was also studied. The insoluble immune complex at equivalence (IC-Eq) and immune complex-antibody excess (IC-Ab) registered a significant increase in number of cells and protein content as compared to soluble immune-complex antigen excess (IC-Ag) complexes. The IC elicited cells showed lesser secretory activity as compared to MPM cells stimulated in vitro. Stimulating capacity of ICs in causing hydrolase release was time and dose dependent. The complement coated complexes were the most effective in inducing enzyme release (4.5-5-fold).

Effect of corticosteroid treatment on various serological & bronchoalveolar lavage abnormalities in patients with sarcoidosis.

Effect of daily oral prednisolone treatment was studied in 29 patients with pulmonary sarcoidosis. Twenty normal control subjects were also studied. Pretreatment absolute lymphocyte counts and proportion of lymphocytes in peripheral blood were significantly lower in patients with sarcoidosis as compared to normal controls. Total cell count and the proportion of lymphocytes in bronchoalveolar lavage (BAL) fluid were significantly higher in sarcoidosis. The proportion of CD3+ and CD4+ was significantly lower in peripheral blood and higher in BAL fluid in patients with sarcoidosis. Immunoglobulins (IgG, A and M) and complements (C3, C4 and CH50) were significantly higher both in peripheral blood and BAL fluid. Patients with sarcoidosis were treated with daily oral prednisolone (30 mg/day). Repeat studies were performed after an interval of 4-6 months in 20 patients with sarcoidosis. A significant increase in absolute lymphocyte counts in peripheral blood and decrease in the proportion of lymphocytes in BAL fluid occurred with prednisolone treatment. Proportion of CD3+, CD4+ and B cells increased in peripheral blood and decreased in BAL fluid. Complement and immunoglobulin levels revealed a significant reduction in peripheral blood and BAL fluid. It is concluded that patients with sarcoidosis have peripheral blood lymphopaenia and lymphocytic alveolitis. They have increased levels of complement and immunoglobulins both in the peripheral blood and BAL fluid. All these abnormalities show significant improvement with prednisolone treatment.

Inherited structural and quantitative polymorphisms of C3b receptor (CR1) in normals and patients with glomerular diseases.

The erythrocyte C3b receptor (CR1) has been studied for its structural and quantitative polymorphisms in normal Indian individuals and in patients with glomerular diseases. In the normal Indian population, purification of CR1 by immunoprecipitation or C3b-Sepharose affinity column and subjecting it to electrophoresis showed the existence of two types of structural polymorphic patterns with M(r) of 190 kDa and 220 kDa, and with gene frequencies of 0.975 and 0.025, respectively. The gene frequencies of these alleles remain unaltered in the patient population. Evaluation of CR1 levels in the normal Indian population revealed a trimodal distribution of CR1 number suggesting a co-dominant allelic pattern (L and H alleles) for the quantitative expression of CR1 with gene frequencies of 0.523 and 0.477, respectively. In our earlier study we have shown that there is a decreased expression of CR1 on the erythrocytes of patients with acute glomerulonephritis. Since this decrease in the CR1 level in patients is an acquired characteristic, it may not be the level controlled by the LL homozygous alleles. The discrepancy in the gene frequencies of the structural and quantitative polymorphic alleles in normal individuals show that they are not linked to each other. In our earlier study, we showed that the affinity constant of C3b-CR1 binding in different individuals remains the same irrespective of the number of CR1 on the erythrocyte surface. Comparison of this result with the present investigation shows that there is no functional difference among various structural polymorphic forms of CR1 and the susceptibility to glomerular diseases is not associated with any of the CR1 polymorphic patterns.

Effect of alcohol on serum lipids & lipoproteins in male drinkers.

The evaluation of the effect of moderate and high doses of ethanol on the serum levels of triglyceride (TG), total cholesterol (TC), cholesterol content of very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL), HDL2, HDL3 subfractions and apoproteins: apo-AI and apo-B was undertaken in 45 (25 controls, 10 moderate and 10 high dose drinkers) healthy males. The results of this preliminary study showed a significant rise in total HDL-cholesterol and apo-AI levels of alcoholics of both the groups. Out of the two subfractions, HDL2 appeared to be induced more. Increased levels of atherogenic lipids (TG, VLDL-chol., LDL-chol. and apo-B) were found in high as well as moderate drinkers. Our results suggest that the benefit of alcohol intake need to be weighed carefully against its considerable risks.

Association between incidence of lipoprotein(a) positivity and coronary heart disease.

Serum samples from 167 (109 male, 58 female) hospital based staff as controls and 760 (596 male and 164 female) clinically documented patients of coronary heart disease (CHD) were subjected to 3.75% polyacrylamide gel electrophoresis for lipoprotein profile and the presence of lipoprotein(a) [LP(a)], which is reported to be an independent risk factor for CHD. Serum total cholesterol, triglyceride and ratio of the electrophoretically separated LDL/HDL lipoprotein fractions were also evaluated. The significant observations are (i) a large proportion of both male and female CHD patients showed the presence of LP(a) as compared to controls, (ii) The incidence of LP(a) positivity was found to be independent of sex and age in controls. Female patients however showed marginal increase (p < 0.05) with age. Male patients of < 40 years demonstrated three times higher incidence of LP(a) presence as compared to their female counterparts, (iii) Comparison of LP(a)+ and LP(a)- patients for serum lipid levels did not show any significant difference. It is inferred that LP(a) positivity may be independent of these lipid variables.

Myocardial dysfunction in diabetic rats: influence of beta-adrenoceptor blockade (propranolol).

The effects of a beta-blocker, propranolol, on the enzyme and isoenzyme activities in the heart muscle in vitro and concomitant histopathology of the component cells of the islets of Langerhans were studied in the Wistar rats after treatment with streptozotocin and isoproterenol. The biochemical data indicated that the isoproterenol induced myocardial infarction (MI) precipitates an acute diabetic response in the rat heart. The superimposition of MI in diabetes mellitus caused significant inhibition of phosphofructokinase and hexokinase in the heart muscle. The lactate dehydrogenase depicted shifting of H-type to M-type in diabetes with or without MI. The drugs, when administered in combination, brought distinctive histopathological changes in beta-cells of the pancreatic islets including degranulation, hyalinosis and a near-total destruction; however A and D cells remained more or less unaffected. The effect of propranolol in diabetes mellitus was uncertain but in MI with or without prior diabetes, the drug inversely altered the activities of all the cardiac enzymes, besides stimulating a mild recuperation of the cells of the endocrine parenchyma.

Evaluation of an enzyme immunoassay based on sonicate supernatant antigens of Mycobacterium w for immunodiagnosis of leprosy.

An enzyme immunoassay (EIA) based on sonicate supernatant antigens of a cultivable, atypical bacterium, Mycobacterium w (M. w), for immunodiagnosis of leprosy is described. M. w was selected after screening of sonicate supernatant antigens of seven cultivable mycobacteria in EIA. The results of the assay were compared with that of EIA using phenolic glycolipid-I (PGL-I). The M. w assay was more sensitive than PGL-I based EIA, for detection of leprosy patients of all categories, including long term treated patients with low bacterial load. The M. w assay was highly sensitive (93.49%) for detection of active LL patients, and the difference in the positivity of the two assays for LL patients was statistically significant (p 0.05). The combined positivity of the assays with M. w and PGL-I for LL was higher than that with either antigen alone. M. w assay, in addition, was also highly sensitive for detection of patients with active pulmonary tuberculosis.

Carbohydrates, lipids and lipoproteins and islet changes in diabetes with superimposed myocardial infarction.

Short-term metabolic and concomitant morphologic effects of streptozotocin diabetes on isoproterenol-induced myocardial infarction was studied in Wistar rats, Of particular significance was the observation that myocardial infarction in concert with diabetes brought about a distinctive exacerbation of the severity and complexity of the histopathological lesions. Of all the biochemical parameters, serum glucose and free fatty acids registered maximum elevation and serum lactate and cardiac glycogen levels a maximum reduction. Among the lipoproteins, an inverse relationship was found between high density lipoproteins and low density and very low density lipoproteins; while high density lipoproteins, ratio of high density lipoprotein to low density lipoprotein and the percentage of high density lipoprotein were decreased, there was a significant increase in low density lipoprotein concentration and percentage values of low density and very low density lipoproteins. In diabetes, the Β cell of the endocrine pancreas depicted selective necrosis. Loss of insulin granules and wide-spread necrobiosis of cellular elements of the pancreatic islets were observed, respectively, in myocardial infarction and in diabetes plus myocardial infarction combinations. Pathological evidence of chemical-induced mild toxicity was present in the exocrine parenchyma. Mitotic features and the presence of centroacinar cells in the damaged Langerhans’ islets supposedly formed the basis of regeneration of the tissue in diabetes, with or without vascular complications.