A Case-Control Study of the Association of Leptin Gene Polymorphisms with Plasma Leptin Levels and Obesity in the Kerala Population.

Background: Over the last few years, the importance of leptin in energy metabolism has been extensively studied in both animal models and in humans. Very few results are available on the association between human leptin gene (LEP) variants and obesity traits in India. We designed this study to analyse the polymorphisms in human leptin gene and the association of sequence variants with obesity among the population in Kerala, South India. Methods: In this case-control design of 148 study participants, data were collected on socioeconomic aspects and anthropometric measurements. Plasma glucose, insulin, leptin, and lipid profile were measured. Genotyping was done by automated DNA sequencing. Results: The common Single Nucleotide Polymorphism (SNP) of 5'-UTR of LEP - 2548G/A was found to be present in the study population with "A" variant as dominant allele. A novel synonymous mutation Thr5Thr of exon 2 of LEP was identified in heterozygous form in one subject with morbid obesity with hyperleptinemia. A novel missense mutation Phe17Leu was observed in two subjects with obesity in heterozygous condition. A novel missense mutation Lys36Arg in exon 2 of LEP was observed in one subject with abdominal obesity and decreased serum leptin level. Conclusion: LEP - 2548G/A at 5'-untranslated region was found to be common with the mutant "A" variant in the study population. SNPs of exons in LEP were found to be rare but associated with morbid obesity and altered levels of serum leptin in the study population in Kerala, India.

Characterization of Five Oxidative Degradation Impurities and One Process Impurity of Suvorexant Drug Substance by LC-MS/MS, HR-MS and 1D, 2D NMR: Validation of Suvorexant Drug Substance and Process Impurities by HPLC and UPLC.

During the oxidative (10% H2O2) degradation of suvorexant drug substance, around 1.0% of one impurity and less than 1.0% four impurities were found by a new high-performance liquid chromatography (HPLC) assay and related substance method. The mass numbers of 1.0% impurity was 469 [M + H]+, remaining four impurities were 172 [M + H]+, 467 [M + H]+, 483 [M + H]+ and 485 [M + H]+. The 469 [M + H]+, 485[M + H] and 172 [M + H]+ impurities were characterized by using the LC-MS/MS, HR-MS and 1D, 2D NMR spectroscopic data. The 172 [M + H]+ impurity was prepared synthetically and co-injected in HPLC. The retention time of synthesized 172 [M + H]+ impurity was matching with the unknown degradation impurity in HPLC. The developed mass compatible HPLC and ultra performance liquid chromatography methods were validated for drug substance and process impurities by following ICH Q2 (R1) guidelines.

An Orthogonal Approach for Determination of Acetamide Content in Pharmaceutical Drug Substance and Base-Contaminated Acetonitrile by GC and GC-MS External Method.

Acetamide is a potential genotoxic impurity; it should control in drug substance based on daily dosage level. It forms from base-contaminated acetonitrile and by-product of some drug substances. The available methods for acetamide in drug substance and water samples were determined by GC-MS using internal standard with critical procedures. These developed and validated methods can assist in evaluating the reaction between acetonitrile and different bases and also determine trace level acetamide in drug substances. The method development was initiated with DB-624, 30 m, 0.32 width and 1.0-µm column. The column was used to validate at the 600 ppm TTC value. Similarly, the CP-SIL 5CB, 60 m, 0.32 width, the 5-µm column was used for the remaining TTC values. The validation study was performed for all TTC limits. The % RSD for precision at 600, 60, 20, 10 and 2.5 ppm was <15%. The % recovery at all TTC level was in between the 70 and 130%. Solution stability study was performed up to the 24 h. At 2.5 ppm, the results were <15% variation from the initial value. The linearities from the 50 to 150% concerning TTC values were more than limit of 0.98 correlation coefficient. The limit of detection and limit of quantitation values were 0.4 to the 1.3 ppm, respectively, for 2.5 ppm TTC limit method.

ST 567 (alinidine) in stable angina: a comparison with metoprolol.

Alinidine, a drug which reduces heart rate without depressing myocardial function was compared against metoprolol, a beta-blocking drug, in the treatment of stable angina pectoris in a double-blind cross-over trial. It was found that both drugs reduced anginal attacks and nitroglycerine consumption to a comparable degree. Exercise tolerance did not appear to be improved by either drug yet chest pain at ergometry was postponed by both drugs. In the doses used metoprolol was more effective in restraining heart rate, both at rest and even more during exertion. Both drugs were well tolerated and side-effects were few. It seems probable that the optimal dose of alinidine was not used in this trial and that the dosage could have been higher.

Early post-infarction angina. Incidence and prognostic relevance.

Early post-infarction angina (2-15 days after infarction) occurred in 132 out of 616 consecutive coronary care unit admissions for acute myocardial infarction within 24 h from onset of symptoms. Patients with early post-infarction angina more often had a history of stable pre-infarction angina as well as late post-infarction angina. Coronary artery disease was more extensive in patients with early post-infarction angina compared with those without angina. Forty-five patients with angina were treated before hospital discharge with coronary artery bypass (CABG) (N = 35) or percutaneous transluminal coronary angioplasty (PTCA) (N = 10). Survival and incidence of non-fatal reinfarctions during 1-year follow-up was similar in patients with and without early post-infarction angina (respectively 83% versus 82% and 13% versus 11%). The incidence of angina in the follow-up was higher in the whole group of patients with early post-infarction angina then in patients without angina (53% versus 32%, P less than 0.001), but was lowest (22%) in the subset who underwent CABG or PTCA before discharge. In patients with early post-infarction angina, age, left ventricular dysfunction, extensive coronary artery disease, stable pre-infarction angina and electrocardiographic ischaemic changes distant from the infarct zone during angina were significantly associated with a poor survival.

Cardiogenic shock. Current concepts in management.

This article presents a categorisation of circulatory shock and discusses the causes, haemodynamics, and clinical recognition of cardiogenic shock. The first step in the management strategy in cardiogenic shock is to guide the patient from the state of shock to one of managed haemodynamic stability. The therapeutic manoeuvres of this first step constitute the management tactics, which can be grouped under 3 general headings: (a) making the most of a malfunctioning heart; (b) improving the state of the heart; and (c) reducing the demands on the heart. In order to make the most of the heart, i.e. to get the highest possible output at the lowest possible cost, clinicians need to use their judgement in stimulating an overtaxed heart on the one hand, and in manipulating the loads on it (the preload and afterload) on the other, for although these methods may be advantageous, they are not without their pitfalls. Efforts to improve the state of the heart often necessitate surgical (e.g. mitral valve replacement) or semisurgical (e.g. coronary angiography and recanalisation) techniques, although intravenous antithrombotic agents may achieve comparable results in a few cases at the bedside. Reducing the demands on the heart is an active process involving the takeover of at least a part of the work of the heart by ancillary devices such as the intra-aortic balloon pump, and of the work of breathing by intubation and artificial ventilation. The individuality of each case of cardiogenic shock emphasises the need for empirical modulation of therapy based on feedback information obtained by haemodynamic monitoring.

Emergency coronary angioplasty in refractory unstable angina.

We performed percutaneous transluminal coronary angioplasty as an emergency procedure in 60 patients with unstable angina pectoris that was refractory to treatment with maximally tolerated doses of beta-blockers, calcium antagonists, and intravenous nitroglycerin. The initial success rate for angioplasty was 93 per cent (56 patients). There were no deaths related to the procedure, although total occlusion occurred in four patients. Despite emergency bypass grafting, all four sustained a myocardial infarction. All the patients were followed for at least six months. Late cardiac death occurred in one patient, whereas eight had recurrent angina pectoris. There was no progression to myocardial infarction. The restenosis rate was 28 per cent (13 of 46) in the patients with initially successful coronary angioplasty who had repeat angiography. Improved cardiac functional status after sustained successful coronary angioplasty was demonstrated by an almost normal capacity on bicycle exercise testing and the absence of ischemia during thallium isotope studies in 80 per cent. We conclude that emergency percutaneous transluminal coronary angioplasty may be useful for the treatment of selected patients with unstable angina pectoris who are unresponsive to intensive pharmacologic treatment.

Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and results of exercise thallium scintigraphy.

To evaluate, during cardiac catheterization, what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer-based quantitative analysis of coronary angiograms was performed on the angiograms of 31 patients with isolated disease of the proximal left anterior descending coronary artery. The angiographic severity of stenosis was compared with the transstenotic pressure gradient measured with the dilation catheter during angioplasty and with the results of exercise thallium scintigraphy. A curvilinear relationship was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal area of obstruction (after subtracting the area of the angioplasty catheter). This relationship was best fitted by the equation: normalized mean pressure gradient = a + b . log [obstruction area], r = .74. The measurements of the percent area of stenosis (cutoff 80%) and of the transstenotic pressure gradient (cutoff 0.30) obtained at rest correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients.

Flecainide: one-year efficacy in patients with chronic ventricular arrhythmias.

During a one-week short-term in-hospital period, 60 patients with chronic ventricular arrhythmias were treated with 200 mg flecainide twice a day. Flecainide reduced premature ventricular complexes (PVCs) by more than 85% without causing important side-effects in 47 patients, who entered a one-year follow-up period and were followed with bimonthly 24-h ECGs. Median PVC-frequency remained reduced by more than 99% during the follow-up period. Repetitive ventricular beats and ventricular tachycardia were present in 83% and 42% of patients, respectively, before flecainide. During follow-up, these arrhythmias were seen in less than 32% and less than 10% of patients, respectively, at each 24-h ECG. Furthermore, the mean number of hours with repetitive ventricular beats and ventricular tachycardia remained reduced by more than 76% and more than 79%, respectively, throughout the follow-up period. Ventricular arrhythmias remained suppressed despite a gradual reduction in flecainide dosages (to a median of 300 mg day-1) and flecainide plasma levels. In nine out of 47 patients, an increase in ventricular arrhythmias above baseline values on one or more occasions was observed. During a flecainide withdrawal period, a 65-fold increase in median PVC-frequency was observed and ventricular tachycardia reappeared in 18 patients. Subjective side-effects were acceptable except for two patients. During the follow-up period, one patient developed reversible heart failure and sinus node dysfunction. During the total study period, four patients, with either severe coronary artery disease (2) or cardiomyopathy (2) developed lethal arrhythmias (3) or ischaemic events (1). We conclude that prolonged flecainide treatment is effective in a high proportion of patients with chronic ventricular arrhythmias. In some patients an arrhythmogenic effect may occur.

Ventricular free wall rupture: sudden, subacute, slow, sealed and stabilized varieties.

Six cases of acute myocardial infarction with blood in the pericardial sac are described. In one case rapid death followed myocardial rupture leaving no time for the possibility of intervention. Of two other cases acute symptoms developing after myocardial rupture, one was operated on promptly and the other, whose condition improved on pericardiocentesis, after a delay of a few hours. Both are now long term survivors A fourth patient probably had two episodes of rupture which apparently sealed off. He underwent cardiac catheterization, but no epicardial leak was found. Subsequently at operation a sealed myocardial rupture was detected and sutured over. The fifth patient suffered a silent myocardial rupture. A false aneurysm was diagnosed four months later and he withstood successful surgery. In the sixth patient, the course was similar to that of case 1, namely rapid death with a clinical picture suggestive of tamponade. Postmortem examination showed a covert rupture with some evidence of attempts to plug the opening. The purpose of this report is to emphasize the varying course which myocardial rupture can take.

Oral flecainide for suppression of ventricular arrhythmias.

The efficacy and safety of oral flecainide for treatment of ventricular arrhythmias were assessed during a 3-day period in patients with various cardiac diseases. Of 11 patients who received a low dose of flecainide (median daily dose 240 mg), only 4 responded with 90% or greater reduction in premature ventricular complex frequency. Ventricular tachycardia could not be suppressed. During treatment no electrocardiographic changes occurred. 14 of the 19 patients who received a high dose of flecainide (median daily dose 480 mg), demonstrated a 90% or greater reduction in premature ventricular complexes, and ventricular tachycardia did not recur during treatment in 7 out of 9 patients. However, PQ, QRS, and QTc intervals were significantly increased. In general, flecainide was well tolerated and drug administration did not have to be discontinued because of side effects. Flecainide acetate treatment, with a median dose of 480 mg daily, appears to be highly effective for suppressing complex ventricular arrhythmias.

Molsidomine, an effective long-acting anti-anginal drug.

Molsidomine was compared with propranolol for anti-anginal efficacy in a double-blind, cross-over, fixed-dose clinical trial, involving 39 patients with moderate, stable angina pectoris, and objective evidence of coronary sclerosis. The incidence of anginal attacks under molsidomine did not differ statistically from that under propranolol. However, propranolol was more effective in reducing the nitroglycerin requirement at the doses used. Ergometry showed that both drugs increased exercise tolerance to a comparable extent. However the rate pressure product during exertion indicates that these drugs achieve this result via different paths, molsidomine having a nitrate-like effect. Unwanted effects during the four week treatment periods were minor and generally tolerable. Molsidomine is an effective long-acting anti-anginal agent with nitrate-like effects and should be a useful addition to the drugs already in use.

The effects of drugs on the exercise electrocardiogram.

Changes in the exercise ECG caused by five different drugs are presented. Analysis of these changes indicate that these are related to the hemodynamic effects of the drugs, rather than to reduction of myocardial ischemia. Calcium antagonists (Verapamil) as well as drugs which reduce heart rate (Alinidine, Propranolol) do not change the relation between ST depression and heart rate in a given patient. Drugs which lower ventricular volume (Molsidomine, Nitroglycerine) reduce the amount of ST depression at the same heart rate during exercise.