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Biomedical subjects

M M Khan

Publications and source records attributed to M M Khan.

At least 109 records · Page 6Linked to original sources
PubMed1993

Double-blind randomized trial of alteplase versus placebo in patients with chest pain at rest.

Patients who have chest pain occurring at rest are at a significant risk of myocardial infarction and or sudden death. Most trials enter patients with anginal rest pain after an initial screening period. Thus, the clinical efficacy of early thrombolytic treatment for patients with rest pain remains unproven. Eighty patients with chest pain at rest and with ECG changes of ST depression of at least 1 mm in any ECG lead, were randomized to alteplase 100 mg infused over 3 h, or placebo. Concomitantly, all patients received intravenous heparin and 300 mg of aspirin daily (unless contra-indicated). Seventy-four patients had coronary angiography (the majority within 72 h of admission) of which 73 were assessable. The patency of the ischaemia-related vessel was not significantly greater in the alteplase treated group (81% vs 78%, P = 0.82). The culprit lesion morphology tended to be more concentric in the alteplase treated group (84% vs 56%, P = 0.06) although alteplase treatment was not associated with a significant reduction in the severity of the culprit lesion stenosis. Intra-coronary thrombi were detected in 7% of patients (3% placebo, 11% alteplase, P = 0.35). The mean left ventricular ejection fraction or the alteplase-treated group was 49 +/- 3% and for the placebo-treated patients 56 +/- 3% (P = 0.05). There was no difference in the total in-hospital cardiac event rate i.e. cardiac death, myocardial infarction and coronary revascularization between patients receiving alteplase (10%, 63%, and 38%) and those receiving placebo (8%, 65%, and 30%) respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Effect of beta-adrenoceptor blockade on atrial natriuretic peptide levels during exercise in angina pectoris.

The effects of epanolol (200 mg once daily) and diltiazem (60 mg three times daily) on the response of atrial natriuretic peptide (ANP) to exercise were investigated in a double-blind placebo-controlled crossover study in 16 patients with angina pectoris. Exercise tolerance as assessed by peak oxygen consumption was similar with all treatments. Peak heart rate (mean and 95% confidence intervals) was lower (P < 0.05) with epanolol (121 (115-130) beats min-1) than with diltiazem (137 (126-148) beats min-1) or placebo (141 (130-152) beats min-1). ANP did not change from resting values with placebo or diltiazem, but rose significantly (P < 0.05) with epanolol from 19.7 (13.0-29.8) pg ml-1 (geometric mean and 95% confidence intervals) during supine rest to 49.6 (33.7-73.0) pg ml-1 at peak exercise. Since ANP release is stimulated by atrial distension, patients with untreated angina may stop exercise before atrial dilatation occurs. With beta-adrenoceptor blockade, a reduction in peak heart rate may necessitate increased chamber volumes to maintain cardiac output, accounting for the rise in ANP.

Adrenergic beta-Antagonists↗
PubMed1993

Role of zinc supplementation in the rehabilitation of severely malnourished children.

A double-blind study was conducted to assess the role of zinc supplementation in the rehabilitation of severely malnourished children. Thirty-three children with severe protein-energy malnutrition received either 40 mg of zinc as zinc sulphate or a placebo during their rehabilitation in addition to the diet containing about 700 kJ and 3-4 g protein per kg body weight/day. Their clinical and biochemical responses were examined. Clinical response and serum albumin synthesis were found to be similar in both the groups. The leukocyte (micrograms/10(10) cells) and plasma zinc levels (micrograms/dl) showed a significant (P < 0.001 and P < 0.01) increase from 46.9 +/- 5.490 to 107.2 +/- 13.224 and 80.4 +/- 9.972 to 107.5 +/- 11.822, respectively, after zinc supplementation. The placebo group also showed a significant (P < 0.025) increase in leukocyte zinc from 45.7 +/- 4.409 to 70.9 +/- 8.414. However, the plasma zinc in the placebo group fell from 83.6 +/- 10.363 to 68.2 +/- 7.031. Plasma copper showed a significant improvement in both zinc supplemented (P < 0.01) and placebo (P < 0.025) groups. The results indicate that zinc supplementation along with the diet would result in rapid restoration of zinc status, though there is no effect on the weight gain or other responses.

Body Weight↗
PubMed1992

Comparative effects of epanolol and diltiazem on exercise performance and respiratory gas exchange in angina pectoris.

The effects of epanolol (a new selective beta-adrenoceptor antagonist), diltiazem and placebo were compared in a group of 16 patients with chronic stable angina pectoris. Each patient received each treatment in random order. Diltiazem reduced weekly angina attack rate from 7.2 (95% CI 3.9-10.5) to 3.9 (1.9-5.9) (P less than 0.01), whereas a lesser reduction was observed after epanolol. Both drugs produced a small but significant (P less than 0.05) increase in treadmill exercise time (placebo 474 s (374-574), epanolol 527 s (431-623) and diltiazem 554 s (462-646). However, aerobic work capacity, assessed by peak achieved oxygen consumption, was not different from the placebo value of 21.2 (18.0-24.4) ml.min-1.kg-1, and clearly subnormal when compared to age- and sex-matched controls (33.0 (30.1-35.9) ml.min-1.kg-1). Ventilatory abnormalities and increased lactate levels on active treatment were observed at peak exercise only. We conclude that the cardiodepressant effects of both active drugs limit blood supply to working skeletal muscle, and that chest pain may be replaced by dyspnoea or fatigue as the limiting factors to exercise.

Adrenergic beta-Antagonists↗
PubMed1992

Impact of the long term supply of iodized salt to the endemic goitre area.

The study was designed to assess the impact of the supplementation levels of iodine in salt supplied since the last 12 years to Gilgit and Hunza, an endemic goitre area of Pakistan. The overall prevalence of visible goitre is reduced from 61.36% to 4.68%. Results of urinary excretion of iodine (UEI) indicate severe to mild iodine deficiency among 70.41% of the randomly surveyed households. Severely deficient are 3%, moderate 29.54% and mild 37.87%, criteria of UEI being less than 2.0 micrograms/dl, 2-5 micrograms/dl and 5-10 micrograms/dl respectively. Levels of iodine supplementation in 267 iodized salt samples at production (n = 128) and consumption (n = 139) points are compared with a mean +/- SD are 70.86 +/- 29.73 ppm and 37.24 +/- 20.47 ppm respectively, representing 566.8 +/- 237.8 micrograms and 297.9 +/- 163.7 micrograms of iodine per 8.0 gram of salt. It is suggested to replace common salt with iodized salt in the goitre area to ensure the use by all households and quality control measures for iodination of salt should strictly be adhered so that uniform and consistent supply of iodine be ensured. The magnitude of contributory factors other than iodine deficiency, i.e., environmental and hereditary should be monitored and considered when levels of iodine supplementation are adjusted.

Female↗
PubMed1992

Study of arterial aneurysms.

A review of 46 patients operated for arterial aneurysms over an eight years period is presented. Twenty-nine patients developed aneurysm following vascular trauma while 17 had atherosclerotic aneurysms. Thirty-one patients presented with painless swelling or swelling with mild pain and four patients with frank rupture. Reconstruction was successful in all cases with a peri-operative mortality of only 4.3%. Unlike western countries, trauma is the leading cause of aneurysm and aneurysms can be managed with minimal morbidity and mortality.

Adolescent↗
PubMed1991

Effectiveness of double bolus alteplase in the treatment of acute myocardial infarction.

Fifty-nine consecutive patients presenting within 6 hours of the onset of symptoms of an acute myocardial infarction were treated with 150 mg of soluble aspirin orally, and either 70 or 100 mg of alteplase divided into 2 intravenous bolus injections separated by 30 minutes. Dosage regimens were either 20 followed by 50 mg (group A), 50 followed by 20 mg (group B), or 50 followed by 50 mg (group C). Coronary angiography 60 minutes after the first bolus showed infarct-related coronary artery patency (Thrombolysis in Myocardial Infarction score 2 or 3) in 13 of 16 (81%) patients in group A, 12 of 17 (71%) in group B, and 10 of 11 (91%) in group C (overall patency rate at 60 minutes: 35 of 44 [80%] patients; 95% confidence interval 68 to 91%). At 90 minutes, patency rates were 15 of 20 (75%) patients in both groups A and B, and 18 of 19 (95%) in group C (overall patency rate 48 of 59 [81%] patients; 95% confidence interval 72 to 91%). Residual thrombus was identified with the 90-minute angiogram in 7 patients in group A, 5 in group B, and 3 in group C. Although there was no statistically significant difference in patency between the 3 dosage regimens at either 60 or 90 minutes there was a trend toward increased patency and more complete thrombolysis at 90 minutes in group C. No episodes of bradyarrhythmia, hypotension or cerebrovascular bleeding were observed after double bolus therapy. There were 7 episodes (12%) of reocclusion, and 3 deaths (5%) within 1-month follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Histamine and its congener derivatives as immune modulators.

Our knowledge of the function of histamine as an immunoregulatory autacoid is expanding. The presence of histamine in many tissues in which the immune response takes place and its release during immune response lend credibility to the notion that histamine's role in the immune response could be an important one. In this report we present data that demonstrate the immune modulatory role of histamine. We also describe the synthesis and novel pharmacologic effects of congener derivatives of histamine. These new lymphocyte specific histamine H1 and/or H2 agonists make it feasible to assess the potential of histamine as a selective in vivo immune modulator.

Animals↗
PubMed1991

Anistreplase in early acute myocardial infarction and the one-year follow-up.

Of consecutive patients seen with first myocardial infarction (88 of whom were treated out-of-hospital by mobile coronary care staff), 139 received 30 units of intravenous anistreplase at a mean of 101 minutes (range 35-180) from onset of symptoms. Thrombolysis in myocardial infarction patency grade 2 or 3 was found in 76/91 (83.5%) patients. At 3-4 months after hospital discharge, the mean global left ventricular ejection fraction and mean infarct-related regional third ejection fraction declined with increasing delay to anistreplase. For the first, second and third hour administrations, global ejection fraction was 54%, 50% and 45% (P = 0.002) and for regional third ejection fractions 49%, 43% and 41% (P = 0.02) respectively. Of the patients, 130 were reviewed at approximately 1 year: reinfarction had occurred in 9, 6 had undergone coronary angioplasty and 1 had coronary arterial bypass grafting performed since discharge. Mean global left ventricular ejection fraction was 52% and mean infarct-related regional third ejection fraction was 51%. Thus, intravenous anistreplase induces high rates of arterial patency. Global and regional third ejection fractions decline with increasing delay in the time of administration of anistreplase. Mortality and morbidity is low in the first year.

Adult↗
PubMed1991

One-year follow-up after recombinant tissue plasminogen activator administered to patients with acute myocardial infarction.

Of 106 patients seen within 4 h of chest pain with 107 episodes of acute myocardial infarction, nine died before or during hospitalization mainly from cardiogenic shock, and four died during the next year, three were sudden deaths. The 93 survivors were reviewed at a mean of 53 (range 49-70) weeks after infarction. Of these 93, 18 had had attempted angioplasty (successful in 12) and 15 had had coronary artery bypass grafting (including one patient who had coronary artery bypass grafting performed after unsuccessful angioplasty). The remaining 61 patients continued on medical therapy only. During the one-year follow-up two patients suffered reinfarction and a further 22 had one or more cardiac admissions, mostly for chest pain. At review, 22 patients had angina (16 New York Heart Association Grade I or II) and five dyspnoea (all NYHA Grade II). Forty-three patients were taking oral nitrates, 53 were receiving calcium antagonists, 54 were using betablocking agents and 73 used anti-platelet agents. However, many of these patients continued on anti-anginal therapy prophylactically after their myocardial infarction, without continuing chest pain. Thus after recombinant tissue plasminogen activator therapy and following hospital discharge the mortality rate for patients with acute myocardial infarction was four out of 97 (4.1%) and reinfarction rate among survivors was two out of 93 (2.2%). Although the incidence of cardiac symptoms was low this may be partly due to the high incidence of angioplasty and coronary artery grafting, together with the use of anti-anginal agents.

Adult↗
PubMed1991

Effect of (-)epicatechin on cAMP content, insulin release and conversion of proinsulin to insulin in immature and mature rat islets in vitro.

(-)Epicatechin, an active principle in the water extract of the bark of Pterocarpus marsupium increases the cAMP content of the islets which is associated with the increased insulin release, conversion of proinsulin to insulin and cathepsin B activity. The response of the islets to the (-)epicatechin stimulation is more pronounced in immature (one month old) than in mature (12 month old) rats.

Aging↗
PubMed1991

Thrombolytic therapy within one hour of the onset of acute myocardial infarction.

Between 1986 and 1988, 239 consecutive patients with acute myocardial infarction received thrombolytic therapy up to 285 minutes after onset of symptoms; in 39 (17 with anterior infarction, 21 inferior, one lateral infarction) recombinant tissue plasminogen activator or anistreplase was administered a mean of 51 minutes (range 20-60 minutes) after the onset of symptoms. The patency rates (26 of 30; 87 per cent), rapid ST segment resolution (36 of 38; 95 per cent) and QRS score of less than or equal to 3 (28 of 38; 74 per cent) were statistically significantly higher for those seen and treated in the first hour in comparison with those seen and treated later. For those treated within the first hour mean peak creatine kinase was 1264 U/l for those with TIMI grade 2 or 3 (partial or complete perfusion) compared with 3005 U/l for those with TIMI grade 0 or 1 (no perfusion or penetration without perfusion) (p = 0.02): mean peak creatine kinase-MB for those with TIMI grade 2 or 3 perfusion was 115 U/l compared with 312 U/l for those with TIMI grade 0 or 1 (p = 0.01). Four of the 39 patients developed ventricular fibrillation following thrombolytic therapy, three within 24 hours of infarction and one following reinfarction on day 15. There were no significant bleeding complications. One patient died. Thrombolytic therapy within 1 hour of the onset of symptoms led to a very high angiographic patency rate, rapid ST segment resolution with preservation of left ventricular function. This therapy is without significant complications.

Anistreplase↗
PubMed1990

Transient release of lipid peroxides after coronary artery balloon angioplasty.

Free radical production may cause myocardial damage during reperfusion of ischaemic myocardial tissue; when free radicals interact with polyunsaturated fatty acids or their esters, lipid peroxides are produced. A product of lipid peroxidation, malondialdehyde, was measured in 10 subjects with stable angina who underwent angioplasty of a proximal high-grade stenosis (over 90%) of the left anterior descending coronary artery. In all subjects the duration of balloon occlusion was 60 s. Blood was withdrawn from the great cardiac vein immediately before balloon inflation (T0), immediately after balloon deflation (T60), 15 s after balloon deflation (T75), and 1 min after balloon deflation (T120). There was a significant increase in malondialdehyde at T60 compared with T0 for the first balloon inflation (mean increase 0.3 mumol/l [95% confidence limits 0.1, 0.5]), and at both T60 (0.31 mumol/l [0.15, 0.47]) and T75 (0.22 mumol/l [0.04, 0.40]) for the second balloon inflation. This model could be used to assess antioxidant effects of drugs.

Adult↗