Lipid peroxidation and diabetic retinopathy.

The high level of glucose in blood for a long duration is the main cause of the development of retinopathy. So yearly screening of patients newly diagnosed with NIDDM diabetes is recommended because rare cases of treatable diabetic retinopathy have occurred early in one course of NIDDM diabetes. Hyperglycaemia leads to non-enzymatic glycosylation of proteins and HbA1C was found increased. Antioxidants such as GSH and SOD level is found decreased in retinopathy conditions due to the higher lipid peroxidation, which is evident from high MDA and DC values. So it can be clearly stated that increase in the free radical by hyperglycaemia, lipid peroxidation and advanced glycosylation endproducts along with decreased antioxidants are the causative agents for the development of retinopathy.

Sevoflurane for induction and intubation in children undergoing congenital cardiac surgery.

The induction and intubation characteristics of sevoflurane were studied prospectively in 23 children, aged 3 months to 6 years (mean 24 +/- 20.25), undergoing repair of congenital cardiac defects. After premedication with syrup chloral hydrate (75mg/kg orally), anaesthesia was induced with 8% sevoflurane and 50% nitrous oxide in oxygen. Nasal endotracheal intubation was performed once the pupils were small and central, without the use of neuromuscular blocking agents or opioids. Characteristics of induction and intubating conditions were recorded. Induction time (from application of face mask to loss of eyelash reflex) was 43.7 +/- 4.57 secs (mean +/- SD). Mean intubation time was 149.1 +/- 15.6 secs. Intubating conditions were excellent in 21 patients (91.3%) and good in 2 patients (80.7%). Haemodynamic parameters (heart rate, rhythm, and systolic blood pressure) were recorded at loss of eyelash reflex, immediately before intubation and at 1, 3 and 5 min after intubation. All children remained haemodynamically stable throughout induction and there were no adverse airway events.

Intraoperative echocardiography as a routine adjunct in assessing repair of congenital heart defects: experience with 300 cases.

Utility of intraoperative echocardiography (IOE) in perioperative management of congenital heart disease has been reported in literature. However, its consistent use as a monitoring tool has not yet been reported from our country. The aim of this study was to evaluate the role of routine use of IOE for intraoperative assessment of surgical repairs in terms of residual shunt, residual gradient, valvular insufficiency and ventricular function. Three hundred consecutive patients above 3 Kg body weight were included in this study. In 152 patients epicardial and in 148 patients transoesophageal echocardiography (TEE) was performed intraoperatively. Age ranged from 4 months to 52 years (median 5.8 yrs) and body weight from 3 Kg to 62 Kg (Median 12 Kg). IOE Doppler and Doppler colour flow imaging studies were performed before cardiopulmonary bypass (CPB) whenever feasible and after CPB in all patients. Pre-bypass examination yielded additional information in 17 (5.6%) patients. In 9 (3%) such patients it had an impact on surgery. In post CPB IOE studies, surgery was found to be 'perfect' in 210 (70%) patients and 'acceptable' residual defects in 70 (23.3%) patients. In 20 (6.6%) cases post CPB IOE found surgical repair 'unacceptable'. Ten of these patients required immediate surgical revision with excellent outcome, thus saving them from late reoperation or postoperative complications. No short term complications were encountered relating to the procedure. We conclude that intraoperative echocardiography is an inexpensive, accurate, valuable and safe addition to the perioperative care of patients and should be mandatory during all corrective surgical procedures for congenital heart disease. It is especially applicable in our country where the costs of reoperation for residual defects are prohibitive.

Right ventricle to pulmonary artery connections.

From March 1988 through June 1995, 80 patients underwent repair for right ventricle (RV) to pulmonary artery (PA) discontinuity. Of these, 30 patients received homograft conduits, while the remaining 50 underwent repair without the use of a homograft. Handmade pericardial valved vascutek conduits (n = 18), non-valved vascutek tubes (n = 13) and non-conduit procedures like the rev operation (n = 12) and extended pericardial gusset (n = 5) were mainly used. The indications for repair for RV-PA discontinuity included ventricular septal defect with pulmonary atresia (VSD PA) (n = 36), truncus arteriosus (n = 18), ventricular septal defect with pulmonary and major aorto-pulmonary collaterals (VSD PA MAPCA) with staged repair (n = 5), congenitally corrected transposition of the great arteries with ventricular septal defect and pulmonic stenosis (CCTGA VSD PS) (n = 5) and double outlet left ventricle with ventricular septal defect and pulmonic stenosis (DOLV VSD PS) (n = 5). The choice of the procedure was governed by various factors, including type of cardiac defect, pulmonary artery pressure and morphology, previous operation, socio-economic constraints and availability of appropriate sized homografts. Non-circuit operations may prevent future reoperations in these patients.

Enhanced lipid peroxidation in patients during coronary artery bypass grafting.

Lipid peroxidation products were measured at various time intervals in 20 patients with coronary artery disease, who underwent coronary artery bypass graft (CABG) surgery. Post-operative blood lipid peroxides were found to be significantly higher (p < 0.001) than the preoperative value. Lipid peroxides raised to a peak value of 46.42 +/- 12.86 n mol/g Alb at 5 min of reperfusion when compared to the basal value and afterwards the level declined to 41.02 +/- 7.09 at 2 hrs and remained in that level even at 24 hrs of reperfusion. This increase implies an enhancement in free radical mediated oxidation of membrane lipids during bypass surgery and thus provides evidence for free radical generation during myocardial reperfusion.

Distribution of cholesterol in HDL and its subfractions in patients with coronary atherosclerotic heart disease.

The distribution of HDL-C and its subclasses HDL3-C and HDL2-C and other serum lipids was studied in patients with coronary atherosclerotic heart disease grouped as young males (group 1) and older males (group 2) along with age matched controls. All the patients had significantly higher levels of serum cholesterol, triglycerides, LDL-C and VLDL-C and lower levels of HDL-C. The analysis of HDL - subclasses clearly demonstrated that the low levels of HDL-C was due to the significant decrease of cholesterol in both HDL3 (group 1: 32%; group 2: 30%) and HDL2 subclasses (group 1: 55%; group 2: 48%) compared to the respective control values. Further it has also been observed that this low level of HDL-C is a characteristic feature of patients irrespective of whether the levels of serum cholesterol and triglycerides are high or normal. Although both the HDL subclasses were decreased, the percentage of reduction of cholesterol was greater in the HDL2 than in HDL3 subclass. In addition, the levels of cholesterol either in HDL or any of its subclasses, HDL3 and HDL2 did not show any change in relation to the extent of coronary disease which was assessed by coronary angiography. This study confirms the inverse relation of HDL-C with coronary atherosclerosis and also indicates that, of all the lipid parameters examined, only HDL-C, particularly its subclass HDL2-C, shows independent inverse relation to the incidence of coronary atherosclerotic artery disease in men.

Congenital asymptomatic absence of pericardium.

An interesting congenital anomaly of the pericardium is its absence. One such case is reported here. Recent literature is reviewed also.

Enzyme-linked immunosorbent assay for riboflavin carrier protein and modified protein: application for epitope analysis.

Rabbit antibodies to native riboflavin carrier protein (RCP), are to a large extent directed towards the conformational epitopes and antibodies to disulphide bond reduced carboxymethylated riboflavin carrier protein (RCM-RCP) to the sequential epitopes. Taking advantage of this premise and in order to map the epitopes of RCP recognized by the antibodies, enzyme-linked immunosorbent assays were validated for RCP and RCM-RCP using the Avidin-Biotin system. The usefulness of these assays were illustrated when antigenicity of peptides derived from RCM-RCP following trypsinization were examined. Two major (T1,T2) and one minor peptide (T3) fractions were obtained when the tryptic peptides were fractionated on DEAE-cellulose. RCP has a blocked N-terminal. Tryptic peptides (T1 and T2) on microsequencing revealed the absence of an N-terminal amino acid, indicating that these fragments emanate from the N-terminal region of RCP. In support of this observation is the finding that antipeptide antibody to cRCP (10-24) of cRCP interacted with T1 as well as T2 indicating the presence of the sequential epitope (10-24) of cRCP in these fragments. In RCP-ELISA, only T2 displaced RCP and peptides T1 and T2 displaced RCM-RCP in RCM-RCP ELISA. Differences in the ability of these fragments (T1 and T2) to displace RCP and RCM-RCP reflect the subtle changes in the spatial structures of these epitopes in RCP and RCM-RCP.

Creatine kinase and its isoenzyme MB in patients after open heart surgery.

Total serum creatine kinase (CK) and its isoenzyme MB (CKMB) were measured before and 4, 24, 48 and 72 hours after termination of cardiopulmonary bypass in patients undergoing (I) atriotomy, (II) ventriculotomy and (III) coronary artery bypass surgery. All patients were free of postoperative complications and myocardial infarction as defined by clinical course, 12 lead ECG and 2D echocardiography. Peak elevation of CK occurred at 24th hour and CKMB at 4th hour and then gradually declined. There was no relation between the peak level of rise of CK or CKMB with cross clamp time or bypass time. The 96th percentile values of absolute CKMB level at 4, 24, 48 and 72 hours may suggest perioperative myocardial infarction with specificity of 95%. In addition, the rising value of CKMB beyond 24 hours after the termination of bypass may also suggest occurrence of myocardial infarction.

Suppression of steroidogenesis in mice granulosa cells by a synthetic nonapeptide fragment of human seminal plasma inhibin.

A synthetic nonapeptide, which is C-terminal sequence of 94-amino acid of prostatic inhibin peptide was tested for progesterone and estrogen secretion by mouse granulosa cell cultures. Nonapeptide suppressed the progesterone and estrogen synthesis, the magnitude of suppression was highest at 5 ng dose level for progesterone and 50 ng dose level for estradiol. The study suggests that, nonapeptide exerts its effect by impairing the binding of FSH to granulosa cell receptors.

Surgical treatment of total anomalous pulmonary venous connection.

Fourteen infants ranging in age from 18 days to 10 months (median age = 4 months) underwent surgical repair of total anomalous pulmonary venous connection (TAPVC) between September, 1988 and December, 1989. The anomalous drainage was supracardiac in nine, cardiac in two, infracardiac in one and mixed in one. One patient had a complex type of TAPVC. There were two hospital deaths, one a critically ill three week old infant with obstructed infracardiac TAPVC and the other with complex TAPVC. There was no late death. All twelve survivors are in NYHA functional Class 1. Postoperative echocardiography revealed unobstructed pulmonary blood flow in all of them. Surgical correction of TAPVC in infancy has been performed with gratifying results. A high index of suspicion, early diagnosis, prompt referral and an aggressive surgical approach are essential for success in this otherwise lethal condition.

Characterization of antibodies to chicken riboflavin carrier protein: Antigenicity of the tryptic fragments.

The antigenecity of tryptic fragments of reduced and carboxymethylated chicken riboflavin carrier protein were studied. The tryptic sites of the native riboflavin carrier protein bound to riboflavin were inaccessible. The molecular weight and the elution profile on high performance liquid chromatography (TSK 545 DEAE) were unaltered at an enzyme to substrate ratio of 1:31. However, carboxymethylated riboflavin carrier protein could be cleaved into 3 or 4 fragments at an enzyme to substrate ratio of 1:250 or 1:125. Chromatographic separation of the tryptic fragments on high pressure liquid chromatography (TSK 545 DEAE) revealed the presence of two fragments with different elution profiles but similar molecular weight 26 ±2 kDa. Only one fragment (associated with peak 2) had the ability to displace chicken riboflavin carrier protein in an homologous chicken riboflavin carrier protein radioimmunoassay. Thus, carboxymethylated ribotlavin carrier protein which does not compete with chicken riboflavin carrier protein in the radioimmunoassay, on mild trypsinization generates a fragment which interacts with chicken riboflavin carrier protein in radioimmunoassay.

A synthetic decapeptide analogue of human seminal plasma inhibin exhibiting specific suppression of follicle stimulating hormone release in rats.

Synthesis and biological profile of a decapeptide analogue, [Tyr85, Cys(Acm)87]85-94 of human seminal plasma inhibin (HSPI) are described. The peptide suppressed the circulatory levels of follicle stimulating hormone (FSH) in adult male rats. No change in the levels of luteinizing hormone (LH) and prolactin (Prl) was observed. Whereas the peptide suppressed the release of both FSH and LH in vitro. This decapeptide is the smallest peptide reported so far to have FSH suppressing activity.