Methylation of E-cadherin and hMLH1 genes in Indian sporadic breast carcinomas.

Hypermethylation of promoter regions leading to inactivation of tumor suppressor genes is a common event in the progression of several tumor types. We have employed a novel restriction digestion based multiplex PCR assay to analyse the methylation status of promoter regions of tumor suppressor genes (p16, hMLH1, MGMT and E-cadherin) in sporadic breast carcinomas of Indian women. The present results indicated the absence of hypermethylation in promoter region of p16 and MGMT genes. However, 6 of the 19 (31.6%) sporadic breast carcinomas showed hypermethylation in the promoters of two of the genes analysed; three in hMLH1 and another three in E-cad. Since our earlier studies have shown lack of genetic alterations such as missense mutations and deletions in the tumor associated genes-p16, ras and p14ARF in sporadic breast tumors, the epigenetic alterations of the two genes reported in the present study could be of interest and might be among the events in the genesis/progression of sporadic breast carcinomas.

Prevalence of proteinuria in non-insulin dependent diabetes.

Proteinuria was estimated in 600 non-insulin dependent diabetes mellitus (NIDDM) patients in 24 hrs collection of urine. The test was repeated at least twice in a year to confirm the persistence of proteinuria. Mild proteinuria (200-500 mg/d) occurred in 94 (15.7%) and nephropathy (> 500 mg/d) in 112 (18.7%) patients. Nephropathy commonly occurred with long-standing diabetes (> 10 years). Development of proteinuria correlated directly with the duration of diabetes, diastolic and systolic blood pressure, age of the patients, serum creatinine and inversely with creatinine clearance. Retinopathy was seen in 75% of those with nephropathy. It is concluded that proteinuria occurs in one third of NIDDM patients and the risk of nephropathy increases with duration of disease.

Pancreatic beta cell function in normoglycaemic offspring of diabetic parents.

The aim of the study was to look for any time-realted fluctuation in the pancreatic beta cell function in normal offspring of diabetic parents, over a period of three years. Serum insulin (IRI) and C-peptide (CP) responses to oral glucose were reevaluated three years after the initial study in 25 normoglycaemic offspring of conjugal Type 2 diabetic parents. The mean area under the curve of IRI (AUC IRI) response was higher than normal control value in the offspring at both time points (P < 0.01) and the two values did not differ much. The 2 hr IRI was also significantly higher (P < 0.05) than the control value. CP responses at both time points in the offspring did not differ from the mean control value. Wide fluctuations in the individual IRI were noted on follow-up despite similar plasma glucose response. Follow-up IRI was higher in 6, lower in 5 (+/- 25% of the initial) and remained unaltered in the other 4 offspring. The corresponding CP showed increased values in 3, decreased values in 5 and no change in 7 offspring. The fluctuations were nonuniform in nature among the individuals studied. Disparity between the IRI and CP responses were present in 5 offspring during the follow-up. This study thus shows that wide fluctuations in insulin responses occur even in the normoglycaemic offspring of diabetic parents.

Glucagon response to glucose load in offspring of conjugal type 2 diabetic parents in south India.

Immunoreactive glucagon responses were measured in 21 normoglycaemic adult offspring of non-insulin dependent (Type 2) diabetic parents, in the fasting state and during an oral glucose tolerance test. In 7 of the 21 offspring, the mean fasting immunoreactive glucagon value was significantly lower than the control value (p < 0.001). In this group, glucose stimulation did not produce inhibition of immunoreactive glucagon secretion. The insulin response in this group was not significantly different from the values in the other study groups. In the other 14 offspring, the pattern of glucagon response to glucose stimulation was similar to controls. It is likely that this non-suppressive effect of glucose on immunoreactive glucagon in some of the "prediabetic" individuals is an early change in the alpha cell function during the natural history of non-insulin dependent diabetes in Asian Indian subjects.

Insulin responses to varying hyperglycaemia in newly diagnosed non-insulin dependent diabetic patients.

The effect of varying degrees of hyperglycaemia on insulin secretion was studied in newly diagnosed non-insulin dependent diabetic patients, stratified according to the fasting plasma glucose values. Of the 116 patients studied, 62 were non-obese and 54 obese. Insulin response patterns during 2h oral glucose tolerance test were analysed in comparison with the values in weight matched control subjects and also with respect to the degree of hyperglycaemia. The effect of hyperglycaemia on beta cell secretion differed in obese and non-obese patients. In the non-obese, fasting insulin levels were within normal range even in those with severe hyperglycaemia while the corresponding values in response to glucose stimulation showed a decreasing pattern. In obese patients, even fasting immunoreactive insulin (IRI) value was decreased and with increasing hyperglycaemia the reduction in IRI response to glucose stimulation was of greater magnitude compared to non-obese patients. Thus the modulating effect of obesity on insulin secretion appears to disappear with development of hyperglycaemia. The insulinogenic index was low in all the diabetic patients.

Microalbuminuria in NIDDM patients in south India.

Urinary albumin excretion (UAE) was estimated by radioimmunoassay in 316 non-insulin dependent diabetic patients (NIDDM), with diabetes for 10 or more years and proteinuria less than 150 mg/24 h. Albuminuria was determined in 24 h collection of urine in 259 patients but in the other 57, a random sample was used. The mean UAE was 23 +/- 45.3 (SD) micrograms/mg creatinine in the patients against 4.4 +/- 2.7 micrograms/mg in the controls (30). Ninety patients (28.5%) had microalbuminuria i.e., the UAE exceeded, 20 micrograms/mg creatinine. A higher percentage (31.7%) of men had microalbuminuria than women (23.6%). The presence of microalbuminuria was similar in the insulin-treated and in oral drug-treated patients (29.6% and 26.5% respectively). Stepwise multiple regression analysis using albumin/creatinine ratio as the dependent variable showed that factors such as blood pressure, blood glucose, HbA1, body mass index, sex, age, duration of diabetes and the association of vascular complications of diabetes did not have significant correlation to microalbuminuria. Creatinine clearance showed a significant inverse correlation to the albumin/creatinine ratio. Although the prevalence of microalbuminuria in NIDDM in this study is not significantly different from those reported from other countries, the morbidity index due to kidney disease could be high due to the large absolute number involved in our country. This underscores the need for early detection of the disease and institution of preventive measures to arrest its progression.

Comparative study of monocomponent insulins and conventional insulins on the course of diabetic nephropathy. A follow-up study.

Two matched groups of insulin requiring non-insulin dependent diabetic (NIDDM) patients with mild proteinuria (200 to 999 mg/day), one on mono component (MC) insulin therapy and the other on conventional insulins were studied for a 3 year period to evaluate the course of nephropathy in these two groups. Twenty-seven and 35 patients were followed-up in the MC insulin and conventional insulin groups respectively. In the MC insulin treated group, the percentage of patients showing deterioration in proteinuria was lower (11% vs 34%, P less than 0.05) and the percentage showing improvement was higher (48% vs 29%) compared to the conventional insulin treated group. Insulin antibody titres decreased significantly in the MC insulin group and serum C-peptide values decreased in both groups on follow-up.

Changes in peripheral insulin concentrations in non insulin dependent diabetes during treatment. Assessment by mathematical applications.

Serum immunoreactive insulin responses to meal stimulus were studied in 20 newly detected non insulin dependent diabetes mellitus patients, following one week of treatment with high carbohydrate, high fibre diet and glibenclamide. Ten patients showed "rapid glycaemic response" i.e. the glycaemic response was good within a week. The rest of them were called "slow responders". The insulin responses were heterogenous. Mathematical calculations using the glucose and insulin responses showed improved beta cell function and peripheral action of insulin in rapid responders. On the other hand, the slow responders showed only slightly improved beta cell function with no change in peripheral action of insulin. The second phase of the study constituted follow-up studies upto 6 months. The corrected insulin response (CIR) increased initially in several patients. The peripheral insulin action improved in all patients with longer duration of treatment and lower insulin concentrations were required to maintain normoglycaemia at this stage. The results of the study indicate that a) multiple factors influence glucoregulation, b) even short term effects of the drug appear to be mediated by extra pancreatic mechanisms, and c) the extrapancreatic action improves significantly on long term use of the drug.

Immunoreactive insulin and insulin degrading enzymes in erythrocytes. A preliminary report.

Immunoreactive insulin (IRI) and insulin degrading enzyme activity (IDEA) of the plasma and the corresponding erythrocyte lysate were estimated in 21 normal volunteers, 18 non insulin dependent diabetic patients (NIDDM), and 16 insulin dependent diabetics (IDDM). The erythrocytes contained several-fold higher concentrations of IRI than in plasma, both in normal and diabetic subjects. The values in controls ranged from 80 to 458 uU/ml against a range of 5 to 25 uU/ml in the corresponding plasma samples. The IRI contents of the diabetic patients were also similar. It showed no correlation to the fasting plasma glucose or the plasma IRI. Following an oral glucose load, no change occurred in the IRI content of the erythrocytes, unlike the changes seen in plasma. The IRI content of the lysate increased with dilution of the sample. The IDEA was higher in diabetic patients compared to controls, especially so in the IDDM (P less than 0.01). It also showed more than one peak activity at different pH of the reaction buffer, indicating the possibility of a complex of enzymes. Human erythrocytes contain large pools of IRI and its degrading enzymes. The significance of the pool of the insulin in non-target tissue needs to be studied.

Combination therapy of glibenclamide and insulin in NIDDM patients with secondary failure to oral drugs.

A trial of combination therapy with glibenclamide + insulin was conducted in 26 patients with non insulin dependent diabetes mellitus (NIDDM) who had secondary failure to oral hypoglycaemic agents (OHA). Patients were included in the study if they failed to respond to a dose of 15 mg of glibenclamide under strict dietary regulations. Small doses of insulin were added until satisfactory glucoregulation was achieved. On withdrawal of the OHA, in 20 patients, the post-prandial plasma glucose values (PPBS) increased again by greater than or equal to 25%; they were considered as "responders". Responders were divided into two equal groups of alternate patients; group I was treated with insulin + glibenclamide and group II with insulin + placebo. The patients were then followed up at monthly intervals for 6 months. The dose of insulin required to maintain normal plasma glucose value was significantly lower (P less than 0.05) in group I. Fewer patients in group I needed two injections of insulin per day; however this difference was not statistically significant. Normalisation of serum triglyceride and lowering of HbA1 occurred in both groups. This study shows that addition of glibenclamide to insulin treatment is advantageous in NIDDM patients showing secondary failure to OHA.

Faecal chymotrypsin assay in tropical and alcoholic chronic pancreatitis.

Faecal chymotrypsin (FCT) levels were estimated in a group of patients with tropical chronic pancreatitis (TCP) and compared with patients with alcoholic chronic pancreatitis (ACP), 'gastrointestinal' controls and 'healthy' subjects. Exocrine pancreatic insufficiency as assessed by low faecal chymotrypsin levels (less than 5.8 mu/g) were present in 85.7 per cent of TPC and 84.6 per cent of ACP patients. Mean FCT levels as well as the distribution of FCT values were similar in TCP and ACP patients and significantly lower than the two control groups (P less than 0.001). There was also no difference with respect to mean FCT levels between subgroups of TCP patients with and without diabetes and those with and without calcification. Faecal chymotrypsin assay is a simple test for diagnosis of chronic pancreatitis in gastroenterological centres in tropical countries.

Abnormalities in insulin response to intravenous glucose in offspring of conjugal (type 2) diabetic parents.

Glucose and insulin responses were measured during intravenous glucose tolerance test in 12 normal controls and 16 normoglycaemic adult offspring of conjugal diabetic parents. The glucose response curve and the glucose disposal rate in the offspring were not different from the normal pattern. These subjects elicited a lower first phase insulin (0-10 minutes area under the curve, p = 0.04), lower peak immunoreactive insulin response (p = 0.032) and also showed a delay in the first phase (p = 0.037) compared to control values. The second phase of insulin (11-120 minutes area) was not significantly different in the two groups. These changes could serve as early markers of diabetes in offspring of conjugal diabetic parents.

Retinopathy in insulin dependent diabetes mellitus (IDDM) in south India.

The prevalence of diabetic retinopathy was assessed by direct and indirect ophthalmoscopy in a group of patients with insulin dependent diabetes mellitus (IDDM). Fourteen percent of patients had retinopathy. Proliferative retinopathy and severe background retinopathy including maculopathy were both seen in four percent of patients. It is possible that the lower prevalence rates for these complications is due to the shorter duration of diabetes in our patients.

Fibrocalculous pancreatic diabetes in the elderly.

Fibrocalculous pancreatic diabetes (FCPD) is a form of diabetes seen in tropical countries. It is secondary to chronic, calcific, non-alcoholic pancreatitis. FCPD is usually a disease of youth. This paper reports on two elderly onset cases of FCPD. Macrovascular complications are usually rare in FCPD patients. These two patients had evidence of macrovascular diseases probably due to the older age group of the patients.