Lead as a Risk Factor for Osteoporosis in Post-menopausal Women

Lead exposure is increasingly becoming an important risk factor for osteoporosis. In adults, approximately 80-90 % of absorbed lead is stored in the bones. These bone lead deposits are released into the blood during periods of enhanced bone resorption like menopause, forming a potential endogenous source of lead exposure. Postmenopausal women are at a higher risk for bone lead release because of hormonal and age related changes in bone metabolism. Estrogen deficiency is associated with increase in osteoclasts number and activity leading to both the early and late form of osteoporosis. Hence, high blood lead level coupled with concomitant environmental exposure exposes women in this age group to lead related adverse outcomes like hypertension, reduced kidney and neurocognitive functions as well as increased risk of atherosclerosis and cardiovascular mortality. A few studies have also identified coexisting variates like ethnicity, occupation, residence, education, smoking, alcohol medications, water etc. as significant determinants of bone and blood lead in women, thus increasing the magnitude of postmenopausal bone changes. Hence, interventions focused on reducing the intensity of bone resorption during menopause will help decrease exposure to endogenous lead. This would play a significant role in decreasing the morbidity and mortality associated with menopause. Also, identification of modifiable factors that prevent bone lead release will reduce the risk of chronic lead exposure and improve the health outcomes of post-menopausal women.

Exploration of eosinopenia as a diagnostic parameter to differentiate sepsis from systemic inflammatory response syndrome: Results from an observational study

Aim of the Study:

Initial differentiation of sepsis from systemic inflammatory response syndrome (SIRS) is of prime importance for early institution of appropriate treatment. This study aimed to compare the differential diagnostic efficacy of absolute eosinophil count (AEC - a routinely available economic marker) with total leukocyte count (TLC) and procalcitonin (PCT - a costly marker available only in specialized settings).

Materials and Methods:

In this prospective observational study, 170 patients of sepsis (severe sepsis = 125; SIRS = 45) were enrolled. AEC, TLC, and PCT were measured in the blood of all patients at the time of admission and data analyzed statistically.

Results:

Median AEC was 0 cells/mm³ in both SIRS and sepsis. TLC and PCT levels were significantly higher (P < 0.001) in culture negative, culture positive, and overall sepsis groups in comparison to SIRS group. At a cutoff of < 50 cells/mm³, AEC demonstrated a sensitivity and specificity of 23% and 68%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of TLC were 57%, 71%, 85%, 37% and of PCT were 82.4%, 82.2%, 93%, and 63%, respectively with area under curve of 0.455 for AEC, 0.640 for TLC, 0.908 for PCT.

Conclusions:

This study suggests that eosinopenia is not a reliable diagnostic tool to differentiate sepsis from SIRS. PCT and TLC are better differential diagnostic biomarkers.

Hyperhomocysteinemia, MMPs and Cochlear Function: A Short Review

Hyperhomocysteinemia (HHCY) has been demonstrated to affect cochlear microvasculature as well as cochlear epithelial cells directly, with a resultant alteration of the expression of matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). Hence, ascertaining the optimum concentration of MMPs and TIMPs in the cochlea could help to inhibit hearing loss due to HHCY by the administration of appropriate MMP inhibitors, Since infections/inflammations as well as ototoxic antibiotics have a similar mechanism of otic pathology, the cochlear damage they cause could also be similarly prevented.

Latent iron deficiency at birth influences auditory neural maturation in late preterm and term infants

BACKGROUND

In utero latent iron deficiency has been associated with abnormal neurodevelopmental outcomes during childhood. Its concomitant effect on auditory neural maturation has not been well studied in late preterm and term infants.

OBJECTIVE

The objective was to determine whether in utero iron status is associated with auditory neural maturation in late preterm and term infants.

DESIGN

This prospective cohort study was performed at Sir Ganga Ram Hospital, New Delhi, India. Infants with a gestational age ≥34 wk were eligible unless they met the exclusion criteria: craniofacial anomalies, chromosomal disorders, hemolytic disease, multiple gestation, third-trimester maternal infection, chorioamnionitis, toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex virus infections (TORCH), Apgar score <5 at 5 min, sepsis, cord blood not collected, or auditory evaluation unable to be performed. Sixty consecutive infants with risk factors for iron deficiency, such as small for gestational age and maternal diabetes, and 30 without risk factors for iron deficiency were enrolled. Absolute wave latencies and interpeak latencies, evaluated by auditory brainstem response within 48 h after birth, were measured and compared between infants with latent iron deficiency (serum ferritin ≤75 ng/mL) and infants with normal iron status (serum ferritin >75 ng/mL) at birth.

RESULTS

Twenty-three infants had latent iron deficiency. Infants with latent iron deficiency had significantly prolonged wave V latencies (7.10 ± 0.68 compared with 6.60 ± 0.66), III-V interpeak latencies (2.37 ± 0.64 compared with 2.07 ± 0.33), and I-V interpeak latencies (5.10 ± 0.57 compared with 4.72 ± 0.56) compared with infants with normal iron status (P < 0.05). This difference remained significant on regression analyses after control for confounders. No difference was noted between latencies I and III and interpeak latencies I-III.

CONCLUSION

Latent iron deficiency is associated with abnormal auditory neural maturation in infants at ≥34 wk gestational age. This trial was registered at clinicaltrials.gov as NCT02503397.

Lipoprotein (a): a Unique Independent Risk Factor for Coronary Artery Disease

The current epidemic affecting Indians is coronary artery disease (CAD), and is currently one of the most common causes of mortality and morbidity in developed and developing countries. The higher rate of CAD in Indians, as compared to people of other ethnic origin, may indicate a possible genetic susceptibility. Hence, Lp(a), an independent genetic risk marker for atherosclerosis and cardiovascular disease assumes great importance. Lp(a), an atherogenic lipoprotein, contains a cholesterol rich LDL particle, one molecule of apolipoprotein B-100 and a unique protein, apolipoprotein (a) which distinguishes it from LDL. Apo(a) is highly polymorphic and an inverse relationship between Lp(a) concentration and apo(a) isoform size has been observed. This is genetically controlled suggesting a functional diversity among the apo(a) isoforms. The LPA gene codes for apo(a) whose genetic heterogeneity is due to variations in its number of kringles. The exact pathogenic mechanism of Lp(a) is still not completely elucidated, but the structural homology of Lp(a) with LDL and plasmin is possibly responsible for its acting as a link between atherosclerosis and thrombosis. Upper limits of normal Lp(a) levels have not been defined for the Indian population. A cut off limit of 20 mg/dL has been suggested while for the Caucasian population it is 30 mg/dL. Though a variety of assays are available for its measurement, standardization of the analytical method is highly complicated as a majority of the methods are affected by the heterogeneity in apo(a) size. No therapeutic drug selectively targets Lp(a) but recently, new modifiers of apo(a) synthesis are being considered.

Polymorphism (C677T) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene: A preliminary study on north Indian men

An elevated level of plasma homocysteine, sulfur containing amino acid generated through demethylation of methionine has been widely accepted as a risk factor for cardiovascular disease (CVD). The increase can result from genetic and/or nutrient related disturbances in the remethylation or transsulfuration pathways for homocysteine metabolism. A common mutation (C677T) in the gene encoding for the enzyme 5, 10-methylenetetrahydrofolate reductase (MTHFR) or deficiency of the B vitamins namely folic acid, B(12), B(6) can lead to hyperhomocysteinemia.In the present study, we have investigated the incidence of the (C677T) MTHFR polymorphism in the North Indian males. 141 angiographically proven coronary artery disease (CAD) patients and 55 age and sex matched healthy volunteers were examined for the association between MTHFR gene polymorphism and CAD. The MTHFR genotyping was performed using polymerase chain reaction (PCR) followed by restriction-isotyping with Hinf 1 endonuclease. A trend for higher 'T' allele frequency (0.19) was observed in patients than in controls (0.16). However no significant association was found between C677T mutation and CAD severity. The lack of statistical significance could be due to the small sample size studied. Hence a larger study including various ethnic groups is warranted.

Studies on homocysteine demonstrating its significance as a possible tool for differential diagnosis in occlusive vascular disease

Homocysteine (Hcy) is a non-protein forming amino-acid, whose metabolism is at the intersection of two metabolic pathways: remethylation and transsulfuration which are dependent on the vitamins folic acid, B(12) and B(6), and the enzymes methylenetetrahydrofolate reductase and cystathionine-β-synthetase. A deficiency of any of these vitamins or enzymes results in hyperhomocysteinemia. This causes oxidative and other damage to blood vessels, thus affecting various organ systems of the body. As part of our ongoing research on cardiovascular risk factors, we have studied the Hcy levels in the plasma of normal controls and those suffering from vascular diseases. It was observed that Hcy is significantly higher in patients of vascular diseases (21.59±1.28 μmol/L, mean±SEM), as compared to normal controls (11.33±0.18 μmol/L). This significance, was more pronounced in cases of venous thrombosis (26.77±2.43 μmol/L) as opposed to cases of arterial block (17.27±0.84 μmol/L). This signifies that Hcy estimation would be beneficial in obtaining a differential diagnosis in addition to being a modifiable vascular risk factor.

Higher incidence of C677T polymorphism of the MTHFR gene in North Indian patients with vascular disease

Homocysteine is a sulfur-containing amino acid, which is derived from dietary methionine. Hyperhomocysteinemia has been implicated in vascular disease for over a decade now, and can be treated with B vitamins. Among its causes is polymorphism of the MTHFR gene, the most common being the cytidine to thymidine at position 677 (MTHFR C677T), which gives rise to three genotypes - normal homozygous CC, heterozygous CT and homozygous variant TT. An attempt was made to ascertain the prevalence of this MTHFR C677T in our population so that preventive measures may accordingly be instituted. Blood samples from 70 patients with vascular disease and 70 healthy controls were analyzed for plasma homocysteine levels (chemiluminescent immunoassay) and for the presence of MTHFR C677T (polymerase chain reaction analysis). Homocysteine was higher in the homozygous subjects (TT genotype) than in the heterozygous (CT genotype). In patients, the frequency of the C allele was significantly lower, and that of the T allele was significantly higher than the corresponding frequencies in controls. In conclusion, the North Indian urban population has higher homocysteine levels associated with the TT genotype. Hence, instituting measures towards reduction of homocysteine levels in the population would probably reduce the incidence and morbidity of vascular disease in our population.

Gibberellic-Acid-induced cell elongation in lettuce hypocotyls

Gibberellic acid (10 muM) causes lettuce hypocotyl cells to elongate by 400-500% more than water controls in 72 hr. Kinetic data indicate that whereas in water controls cell elongation occurs between 24 and 48 hr, in gibberellic-acid-treated material it starts at 8 hr and continues to 72 hr. Dry weight of the cell wall shows a corresponding increase with cell elongation. Two-hour pulse labeling with [(14)C]glucose, however, indicates a peak in the incorporation of label in the wall fraction at 8 hr, when growth has only just begun, and a progressive decline later, when elongation is occurring at maximum rate. The peak coincides with extensive dictyosomal activity, proliferation of endoplasmic reticulum and polyribosomes, and connections between the endoplasmic reticulum and plasmalemma in both water- and gibberellic-acid-treated hypocotyls. At later times, the cells contain only a thin layer of cytoplasm and no special cytological features are observed. These observations indicate that, although cell growth in lettuce hypocotyls is accompanied by wall synthesis, nevertheless the cells undergo their most rapid polysaccharide and protein synthesis prior to extension growth. They also explain the earlier reported "enhanced sensitivity" of lettuce hypocotyls to gibberellic acid application at 8 hr after the beginning of the experiment.

Effect of ascorbic acid on prevention of hypercholesterolemia induced atherosclerosis

The notion that oxidation of lipids and propagation of free radicals may contribute to the pathogenesis of atherosclerosis is supported by a large body of evidence. To circumvent the damage caused by oxygen free radicals, antioxidants are needed which provide the much needed neutralization of free radical by allowing the pairing of electrons. In this study we have investigated the effect of ascorbic acid, a water soluble antioxidant on the development of hypercholesterolemia induced atherosclerosis in rabbits. Rabbits were made hypercholesterolemic and atherosclerotic by feeding 100 mg cholesterol/day. Different doses of ascorbic acid were administered to these rabbits. Low dose of ascorbic acid (0.5 mg/100 g body weight/day) did not have any significant effect on the percent of total area covered by atherosclerotic plaque. However, ascorbic acid when fed at a higher dose (15 mg/100 g body weight/day) was highly effective in reducing the atherogenecity. With this dose the percent of total surface area covered by atherosclerotic plaque was significantly less (p < 0.001). This suggests that use of ascorbic acid may have great promise in the prevention of hypercholesterolemia induced atherosclerosis.

Oxidative damage of plasma proteins and lipids in epidemic dropsy patients: Alterations in antioxidant status

Epidemic dropsy is an acute food adulterant disease caused due to consumption of edible mustard oil contaminated with argemone oil. Our in vitro studies have shown that the toxicity of argemone oil is due to the production of reactive oxygen species. The present study was aimed to evaluate the development of oxidative stress in terms of oxidation of plasma proteins and lipids and its correlation to enzymatic and non-enzymatic antioxidants in epidemic dropsy patients. Total plasma protein and globulin contents were found to be significantly (P<0.05) enhanced with a concomitant decrease (P<0.05) in albumin/globulin ratio in dropsy patients when compared to controls. Total cholesterol, triglycerides, low density lipoprotein cholesterol and very low density lipoprotein cholesterol were found to be significantly (P<0.05) increased with a simultaneous decrease (51%) in high density lipoprotein cholesterol in dropsy patients. The oxidation of plasma proteins and lipids were substantially enhanced (162-175%) in dropsy patients when compared to controls. Further, significant (P<0.05) decrease in superoxide dismutase, catalase, glutathione reductase and glutathione-s-transferase with a concomitant increase (69%) in glutathione peroxidase activity was noticed in dropsy patients. A significant reduction in plasma total antioxidant capacity, alpha-tocopherol, glutathione, retinol and retinyl esters content was observed in dropsy patients when compared to healthy controls. The results suggest that there exists an unproportionate equilibrium between free radicals formation and enzymatic and non-enzymatic antioxidant scavengers, which may cause oxidative damage to proteins and lipids in dropsy patients.

Apolipoprotein C3 SstI polymorphism in the risk assessment of CAD

Various population studies have reported the association of rare S2 allele of apolipoprotein C3 (APOC3) SstI polymorphism with hypertriglyceridemia (HTG) and coronary artery disease (CAD). We were the first to report an association of S2 allele with high triglyceride (TG) levels in healthy volunteers from Northern India. Since HTG is suggested to be a predominant risk factor for CAD among Indians, we have elucidated the relationship of APOC3 SstI polymorphism with the lipid profile and CAD. A total of 158 patients with > or = 70% stenosis in one or more coronary artery (angiographically proven CAD patients), 35 subjects with < 70% stenosis (NCAD) and 151 normal controls (free of heart disease) from Northern plains of India were recruited in the study. DNA samples were analyzed by polymerase chain reaction (PCR) followed by SstI digestion. Lipid profile was estimated by enzymatic kit. We found a strong association of S2 allele with high TG levels, which was more significant in patients. Prevalence of S2 allele in normal controls and CAD patients were comparable, despite the fact that mean TG level was significantly higher in patients. A greater insight into this observation revealed that the prevalence of high TG, if not coupled with other risk factors (like high total cholesterol, low HDL), was comparable in patients and controls. Thus, our study reveals that rare S2 allele may be employed as a susceptibility marker for high TG. However, high TG or S2 allele alone may not contribute to the etiology of CAD.

Modulation of urinary CR1 in systemic lupus erythematosus

The decline in the levels of erythrocyte complement receptor 1 (ECR1) in systemic lupus erythematosus (SLE) has been widely reported. The most probable cause for this decline is excessive proteolytic shedding of CR1 from the cell surface. Similarly a decline in glomerular CR1 (GCR1) has also been reported in SLE. Because CR1 is excreted in urine it is imperative to study the relationship of urinary CR1 (uCR1) with ECR1 and GCR1, and their overall correlation with disease activity. We have determined the levels of uCR1, ECR1 and GCR1 in SLE patients and compared them with normal controls and minimal change disease (MCD) patients. We found a significant decline in both uCR1 and GCR1 in SLE but not in MCD; levels of uCR1 in MCD were either comparable to those of controls or higher. Immunofluorescence for GCR1 was very high in MCD. We did not find any correlation between ECR1, uCR1 and kidney function tests on divariate scatter analyses. The correlation coefficient for uCR1 and GCR1 was highly significant and positive. Our findings thus suggest that uCR1 reflects the levels of GCR1 expression, which decline drastically in SLE. Therefore we envisage uCR1 as a potential marker for glomerular involvement in SLE.

Analysis of the apo(a) size polymorphism in Asian Indian populations: association with Lp(a) concentration and coronary heart disease

Most studies aiming to detect associations of genetic variation with common complex diseases, e.g. coronary heart disease (CHD) have been performed in populations with a western lifestyle but it is unclear whether associations detected in one geographic group exist also in others. We here have determined lipoprotein(a) levels and apo(a) K-IV-2 repeat genotypes in CHD patients (N=254) and controls (N=480) from two Asian Indian populations (Tamil Nadu and New Delhi). In both populations and also in the pooled dataset median Lp(a) levels were significantly elevated in the patients (27.4 mg/dl) compared with the controls (17.6 mg/dl). Apo(a) K-IV-2 allele frequencies were not different between the CHD patients and controls and thus did not explain the increased Lp(a) levels in CHD patients. Contrary to what has recently been observed in Black and White men short (K-IV<or=22) alleles associated with high Lp(a) concentration were not overrepresented in the patients. Rather, short (K-IV<or=22), intermediate (K-IV 23-29) and long (K-IV>or=30) apo(a) alleles were all associated with higher Lp(a) levels in the patients. Accordingly relative risk (estimated as odds ratio) for CHD rose continuously with increasing Lp(a) but was independent of apo(a) allele length. Together with previous studies our results indicate that the relation between apo(a) genotypes, Lp(a) levels, and CHD may be heterogeneous across ethnic groups and that it depends on the genetic architecture of the Lp(a) trait in a given population whether an association of K-IV-2 repeat length with CHD exists or not.

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.

Apolipoprotein C3 SstI polymorphism and triglyceride levels in Asian Indians

BACKGROUND

A close association between Sst I polymorphism in the 3' untranslated region of the apolipoproteinC3 (APOC3) gene and levels of plasma triglycerides (TG) had been reported by different investigators. Hypertriglyceridemia(HTG) is a known risk factor for coronary artery disease (CAD) in the context of Asian Indians. We conducted a study on the relationship between APOC3 SstI polymorphism (S1S1, S1S2 and S2S2 genotypes) and plasma TG levels in a group of 139 male healthy volunteers from Northern India.

METHODS

DNA samples were analyzed by polymerase chain reaction (PCR) followed by SstI digestion. Digested PCR products were run on 3% agarose gel and visualized by ethidium bromide staining.

RESULTS

Rare S2 allele was highly prevalent in our study population (0.313) as compared to the Caucasians (0.00-0.11). The genotypic distribution was in agreement with Hardy-Weinberg equilibrium. S2 allele was almost two times more prevalent in the HTG group (N = 34) as compared to NTG group (N = 105) (p = 0.001). Multiple logistic regression revealed S1S2 individuals had age-adjusted odds ratio of 2.43 (95%CI = 0.99-6.01, p = 0.054) and S2S2 had 9.9 (95%CI = 2.66-37.29, p = 0.0006) for developing HTG in comparison to S1S1 genotype.

CONCLUSIONS

Our study shows a significant association between rare S2 allele and HTG in Asian Indians.

Apolipoprotein E polymorphism in Northern Indian patients with coronary heart disease: phenotype distribution and relation to serum lipids and lipoproteins

Apolipoprotein E (apo E), a genetic determinant of plasma lipid levels and coronary heart disease (CHD) needs to be investigated in Asian Indians since they have a propensity to develop dyslipidemia and accelerated atherosclerosis. We studied apo E phenotypes and plasma lipid levels in 52 Northern Indian male patients (aged 38-71 years) with angiographically proven CHD, and compared them to 50 healthy blood donors taken as the control group. High levels of Lp(a), (p < 0.05), and a definite trend towards lower levels of HDL-C (p < 0.05), was observed in the CHD patients as compared to the control subjects. The frequency of apo E allele epsilon3 was 0.86 and 0.862, and epsilon4 allele was 0.12 and 0.08 in the patients and controls, respectively. However, a lower frequency of the E2 allele was observed in the patient group (E2 = 0.02) as compared to the controls (epsilon2 = 0.06) (p = ns). In individuals with apo E3/E3 phenotype, significantly lower HDL-C levels was observed in the CHD patients as compared to the control subjects (p < 0.05). A positive correlation was observed between apo E phenotypes and Lp(a) levels in the CHD subjects as compared to the controls (p < 0.05), the level being significantly high in CHD subjects with at least one E4 allele. To conclude, in this sample of Northern Indian subjects with CHD, there is a significant correlation between apo E3/E3 phenotype and low levels of HDL-C as compared to the control subjects. Further, apo E phenotype is positively correlated with high Lp(a) levels in the CHD subjects having at least one E4 allele. However, these relationships need to be explored in a larger sample of subjects.

Validation of an ELISA for the quantitation of human complement receptor 1

An ELISA was developed and validated for the quantitation of Complement Receptor 1 (CR1) in human plasma. The ELISA employed a monoclonal anti-CR1 antibody adsorbed onto microtiter plates to capture CR1 in human plasma. The captured CR1 was treated with a detecting antibody which had a different epitopic specificity for CR1. HRP conjugated anti IgG (secondary antibody) was used for quantitation. The standard curve covered a wide range from 10 pg to 800 pg. The inter- and intra-assay variation were found to be low and within the acceptable limits. Specificity and accuracy for the assay was established by ensuring negligible cross reactivity with other proteins and an excellent parallelism between the sample and standard curve. The samples were checked for loss of sCR1 levels through freeze/thaw cycles at different intervals of time stored at -70 degrees C.

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.

Expression of complement regulatory proteins in diffuse proliferative glomerulonephritis

This study assessed the expression of complement receptor 1 (CR1), decay accelerating factor (DAF) and membrane inhibitor of reactive lysis (CD59) on the erythrocytes and glomerulus of diffuse proliferative glomerulonephritis (DPGN) of systemic lupus erythematosus (SLE) patients using flow cytometry and immunofluorescence techniques to elucidate their role in the pathogenesis of DPGN. Expression of CR1 on the erythrocytes and glomerulus of DPGN patients was reduced compared with expression in normal subjects. However, expression of DAF and CD59 was increased on both erythrocytes and glomerulus of DPGN patients, suggesting the generation of a protective response against complement-mediated injury.

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.

Differences in the platelet proaggregatory activity of immune complexes isolated from patients with myocardial infarction or pulmonary cancer

Immune complexes were isolated immediately after the onset of the symptoms of myocardial infarction on an anti-Clq affinity column. The platelet proaggregatory effects of these immune complexes were compared with those isolated from patients suffering from pulmonary cancer. A markedly increased proaggregatory effect of immune complexes derived from patients with myocardial infarction and changes in the sensitivity of platelets from healthy volunteers to PGI(2) (prostacyclin) and PGD(2) were found. In contrast, immune complexes from patients with pulmonary cancer did not show any significant effect. The antigenic part of immune complexes is probably relevant in the induction of platelet aggregation.

Complement-regulatory protein expression and activation of complement cascade on erythrocytes from patients with rheumatoid arthritis (RA)

It has been previously reported that the expression of the complement receptor, CR1, on erythrocytes is reduced in patients with RA and that the reduced expression of CR1 is related to disease activity. In this study we investigate the role of other regulatory proteins, i.e. decay-accelerating factor (DAF) and CD59 (membrane inhibitor of reactive lysis), in the pathogenesis of RA by checking the expression of DAF and CD59 on erythrocytes of RA patients to establish whether reduced expression of DAF and CD59 on erythrocytes could be related to increased ability of erythrocytes to activate complement in RA. Flow cytometry was used to measure the expression of DAF and CD59 on erythrocytes from RA patients as well as the deposition of C3 fragments occurring in vivo or after in vitro complement activation. Significantly reduced expression of DAF and CD59 was observed on erythrocytes of RA patients. A significant inverse relationship was observed between DAF expression and in vitro complement activation, whereas no significant relationship between CD59 and complement activation was observed. Finally, we demonstrated an inverse relationship between CH50 activity and DAF expression. Thus, determination of DAF on erythrocytes can emerge as an additional tool in the assessment of extent of complement activation in RA.

Genotypic detection of mutations in rifampicin resistant clinical isolates ofMycobacterium tuberculosis

The resistance of majority ofM. tuberculosis strains to rifampicin a key drug in the tuberculosis therapy, has been cause of major alarm world-wide. Such an association of strain with the drug takes a long time i.e. 2-3 months. We have modified a method for rapid detection of rifampicin resistant strains by screening them through PCR-SSCP.We have identified mutations in rpo, β region of the gene encoding, β sub-unit of RNA polymerase in rifampicin resistant 67 clinical isolates ofM. tuberculosis. Mutations were screened in these isolates by single strand confirmation polymorphism (SSCP). When DNA sequencing data was compared with the result of SSCP analysis, direct PCR sequencing results were more easily interpreted and contatined more sequence dependent information. These findings provide the basis for rapid detection of rifampicin esistance, a marker of multidrug resistance.

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).

Distribution of apolipoprotein E genotypes in Asian Indians, Hungarians, and Papua New Guineans

We report here the distribution of apo E genotypes and allele frequencies in Asian Indians, Hungarians, and Papua New Guineans using the DNA based analysis. Frequency of the apo E4 allele was thrice as high in Papua New Guineans as compared to the Caucasians. The rare apo E2 allele was also present in higher frequency in the Papuas as compared to other populations.

Effect of MaxEPA (fish oil) on lipoproteins and its receptors in hypercholesterolemic rabbits

The effect of dietary MaxEPA (fish oil) supplementation on cholesterol induced hypercholesterolemia in rabbits was investigated. Rabbits were fed 0.1% cholesterol enriched diet for one month and randomly divided into two groups (I and II). Group I was continued on a 0.1% cholesterol rich diet whereas group II in addition to cholesterol supplementation received MaxEPA (2.5 g/kg body weight) per day for a period of two months. B-VLDL-C, LDL-C and total serum peroxide levels (TBARS) were significantly higher in group II animals as compared to group I. No statistical difference was found in the number of hepatic B-VLDL binding sites between group I and II. Microscopic examination of the aorta showed an increase in the number of intimal foam cells in MaxEPA treated group, a result that may be linked to increase in total cholesterol, plasma TBARS and with simultaneous reduced hepatic uptake of B-VLDL.

Hind III genomic polymorphism of the C3b receptor (CR1) in patients with SLE: low erythrocyte CR1 expression is an acquired phenomenon

Expression of the human erythrocyte C3b receptor (CR1-CD35) and its Hind III RFLP was studied in a group of 37 patients with SLE, 15 consanguineous relatives of the patients and 48 healthy normal subjects. The CR1 number on erythrocytes was quantitated by ELISA using a mAb to CR1. Serum levels of complement proteins (C3, C4, C3d) and circulating immune complexes (CIC) were estimated simultaneously in controls and relatives. The patients were followed up during the course of the treatment. The CR1/erythrocyte (CR1/E) in patients were found to be significantly low in comparison to controls. The gene frequencies for the alleles H and L (7.4 and 6.9 kb Hind III restriction fragments) in the patients were 0.75 and 0.25, respectively, which did not differ significantly from the controls (0.77 and 0.23 in normal subjects and 0.79 and 0.21 in consanguineous relatives of the patients). However, patients expressed fewer CR1/E within each genotype than their relatives and healthy subjects. CR/E was found to be stable in consecutive samples in controls. In patients, the numbers varied between low and high during the course of the treatment. The variation in the numbers was significantly correlated with C3d and CIC as well as with the severity of the disease. Our results suggest that low levels of CR1 on erythrocytes in SLE patients are required during the course of the disease and that the 6.9 kb restriction fragment does not play a role in causing susceptibility to the disease.

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.

Particulate suspension model for blood flow under external body acceleration

A mathematical model has been developed to investigate the influence of externally imposed periodic body acceleration on blood flow in aorta and arteriole. The rheological properties of blood has been represented by regarding the blood as a two-phase Newtonian fluid, that is, a suspension of cells in plasma. An exact analytical solution of coupled differential equations, describing the flow of a particle-fluid suspension, is obtained using the Laplace transforms technique. The effects of body acceleration and blood cells concentration on velocity, flow rate, acceleration and shear rates are computed and displayed graphically.

Lowered expression of C3b receptor (CR1) on erythrocytes of rheumatoid arthritis patients

The number of C3b receptors (CR1) on erythrocytes (E) has been quantitated by whole cell enzyme-linked immunosorbent assay (ELISA), using a monoclonal anti-CR1 antibody, in 46 healthy individuals as controls, 58 having rheumatoid arthritis (RA) and 3 hereditary angioedema patients. The mean value of CR1 in RA (381/E) was significantly lower (p < 0.001) when compared to normal controls (646/E). In hereditary angioedema patients CR1 numbers (620/E) were found to be comparable to normal values. No significant difference was found between normal male (708/E) and female (598/E) subjects. Among the patient groups, those on steroid therapy (352/E) showed no change compared to others not receiving such therapy (408/E). The cumulative frequency curve of CR1 in the normal population showed maximum inflection at 32% and 82%. This led us to conclude that there is a trimodal distribution of receptors in the control population. Such a contention is well supported by frequency histogram, when a small group interval (0-50) was chosen. However, if large group intervals (0-100 or 0-150) were considered, a very close approximation to unimodal pattern was obtained. The factors actually contributing to low receptor numbers are yet to be elucidated.

Developing blood flow in the entrance region of an artery

Presented herein are the studies of the flow behaviour of blood in the entrance region of a segment of an artery. The artery has an axisymmetric mild stenosis developed right from the entry cross section. The blood has been represented by a Bhingham fluid model which also takes the core region, formed due to axial migration of the red blood cells, into account. The flow in the artery has been divided into two regions developing boundary layer and a central core region. A fourth degree velocity profile satisfying the boundary conditions at the wall and the matching conditions at the core and the boundary layer interface is introduced in the governing momentum integral equation. The indicated integration provides a relation for the boundary layer thickness for each axial position. The results for the pressure distribution, entrance length and the wall shear stresses are discussed for the various values of the parameters involved in the analysis. The analysis predicts that the entrance length increases as the stenosis grows and therefore the heart has to put in more energy into transporting blood. It seems that there is some inbuilt mechanism which keeps the entry region of every segment to a minimum in normal arteries at each junction. This length increases in pathological states leading to various types of hypertensive diseases due to the formation and growth of the stenosis.

C3b receptor (CR1) genomic polymorphism in rheumatoid arthritis. Low receptor levels on erythrocytes are an acquired phenomenon

The number of complement receptor 1 (CR1, CD35) molecules on erythrocytes is genetically determined by two codominant alleles. The numerical expression of CR1 on erythrocytes correlates with a HindIII-RFLP or CR1 gene using CR1-1, a complementary DNA probe. We have found low CR1 on erythrocytes in patients with rheumatoid arthritis (RA) in an Indian population. Low levels in RA patients may be acquired or genetically determined. Fifty-two patients with RA, 48 nonrelated healthy subjects and 19 consanguineous relatives of patients were genotyped. CR1 numbers on erythrocytes were quantitated by the enzyme-linked immunosorbent assay using monoclonal anti-CR1 antibody. Normal subjects and patients were followed up for a period of 6 months to evaluate the stability of their CR1 expression. The gene frequency for allele H and L (7.4- and 6.9-kb HindIII restriction fragment, respectively), which correlated with high and low expression of CR1 on erythrocytes was 0.77 and 0.23 in the normal controls. Gene frequency in RA patients was 0.78 and 0.22 for H and L allele, which did not differ significantly from either controls or relatives (0.80 and 0.20 for H and L allele, respectively). However, RA patients expressed fewer CR1 on erythrocytes within each genotype than their relatives and controls. CR1 on erythrocytes were found to be stable in consecutive samples in controls. In RA patients, the number varied between low and high during the course of the disease. The variation in number was significantly correlated (p < 0.05, r = -0.85 to -0.98) with disease activity as monitored by erythrocyte sedimentation rate. Our results suggest that low levels of CR1 on erythrocytes in patients with RA are not inherited, rather they are acquired during the course of the disease.

Relation between alcohol intake, lipoproteins and coronary heart disease: the interest continues

This paper reviews the much discussed association between alcohol intake, lipoproteins and coronary heart disease (CHD). Epidemiological studies have consistently shown an inverse trend between low to moderate alcohol consumption and CHD. Such a protective effect of alcohol against atherosclerosis has been associated with the elevated concentration of HDL-cholesterol induced by alcohol. However, the underlying mechanisms whereby alcohol drinking enhances HDL-cholesterol levels are not yet fully clear. Various lifestyle variables, namely diet, smoking, hypertension, body mass index and exercise, can affect the lipoprotein status in both users and non-users of alcohol.

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.

Complement activation in pulmonary tuberculosis

The alterations in serum/plasma levels of total haemolytic complement activity (CH50), complement components C3 and C3d, and circulating immune complexes (CICs) in patients with pulmonary tuberculosis were analysed in relation to the severity of disease and treatment status. The mean levels of CH50, C3, C3d and CICs were significantly higher in untreated than treated patients and in normal controls. In the untreated group, the level of each of these four parameters except C3d was significantly higher in patients with far advanced disease than in those with moderately advanced disease, whereas the difference between treated patients and normal controls was not statistically significant for any of the four parameters tested. There were statistically significant correlations between levels of CICs and both C3 and C3d in the untreated tuberculosis patients. However, the correlations for the same parameters were not significant when treated patients were considered. The CH50 levels in tuberculosis patients suggest a functional classical complement pathway, which is essential for immune complex solubilisation. High C3d level in untreated patients is indicative of increased complement activation, which in turn shows significant correlation with levels of CICs. It appears that the intact and elevated complement proteins and their proper activation by CICs prevents tuberculosis from becoming a typical immune complex disease.