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Biomedical subjects

V S Mathur

Publications and source records attributed to V S Mathur.

At least 55 records · Page 3Linked to original sources
PubMed1984

Intravascular microaggregation and in vitro platelet aggregation in coronary artery disease.

To investigate in vivo and in vitro microaggregation in coronary artery disease, we obtained blood samples from the coronary sinus (CS), pulmonary artery (PA), and aorta (AO) in patients undergoing cardiac catheterization. An electronic particle size analyzer was used to quantify microaggregates 13 to 81 mu in diameter in blood. In the first group of 58 patients, preformed circulating microaggregates and platelet responsiveness to ADP were assessed in AO and PA blood only. The coronary artery disease patients did not have significantly higher volumes of preformed in vivo aggregates in either AO or PA blood. However, the mean aggregate size in response to 0.2 microM ADP in vitro was larger in both AO and PA blood in patients with coronary disease [12.4 +/- 0.9 vs. 9.4 +/- 1.4 X 10(3) mu3 (AO); 12.5 +/- 0.9 vs. 8.3 +/- 0.7 0.7 X 10(3) mu3 (PA)]. In a second group of 46 patients, CS, AO and PA samples were compared using the same methods. The volume of microaggregates preformed in vivo was significantly greater in CS blood than in PA or AO blood in patients with and without coronary disease. The volume and mean size of aggregates induced by ADP in vitro were smaller in CS blood compared to PA. In conclusion, the volume of in vivo microaggregates is increased in CS blood, independent of coronary disease, but significant volumes are not found in PA or AO blood. Patients with coronary disease have more reactive platelets to in vitro aggregatory agents in AO and PA samples of similar hematocrit.

Adenosine Diphosphate↗
PubMed1984

Restenosis after transluminal coronary angioplasty detected with exercise-gated radionuclide ventriculography.

Forty-one patients were evaluated with exercise-gated radionuclide ventriculography before and within 4 days after successful transluminal coronary angioplasty and 4 to 12 months later. Patients were subgrouped according to the degree of restenosis demonstrated angiographically at 4 to 12 months (Group I [n = 23]: less than or equal to 20%; Group II [n = 10]: greater than 20% but less than 50%; Group III [n = 8]: greater than or equal to 50%). Patients with abnormal findings on gated radionuclide ventriculography (less than 5 point increase in ejection fraction or wall motion deterioration) early after angioplasty were eventually found to have a greater degree of restenosis than were patients with normal findings (41.2 +/- 30.3 versus 19.0 +/- 25.4% restenosis, p less than 0.0001). The accuracy of abnormal radionuclide ventriculography in predicting 50% or greater restenosis was 73% immediately after angioplasty and 77% at the time of follow-up angiography. Gated radionuclide ventriculographic results were abnormal in 5% of Group I patients compared with 75% of Group III patients (p less than 0.01) early after angioplasty; at late follow-up, they were abnormal in 27% of Group I patients compared with 88% of Group III patients (p less than 0.01). Group I patients had a greater increase in ejection fraction than did Group III patients at early (+11.3 +/- 7.5 versus + 3.5 +/- 6.5 points, p less than 0.01) and late (+11.8 +/- 7.8 versus -1.9 +/- 8.7 points, p less than 0.0005) follow-up. It is concluded that gated radionuclide ventriculography is useful in predicting coronary restenosis after transluminal coronary angioplasty.

Aged↗
PubMed1984

Coronary revascularization in the elderly patient.

A total of 1,275 elderly patients (70 years and older) underwent coronary artery bypass alone from 1970 to 1981. The percent of elderly patients who underwent coronary bypass surgery alone increased from 2.04% in 1971 to 8.2% in 1981. Most of the patients had severe, disabling or unstable angina pectoris. The overall early mortality rate was 5.8%. The early mortality rate was 13.9% in the first group (1970 to 1975) of 158 patients compared with 4.7% in the second group (1976 to 1981) of 1,117 patients. An average of 3.1 bypass grafts per patient were implanted. On follow-up examination, angina was relieved or decreased in 89% of the patients. The 5 year survival rate was 80.6% and the 10 year survival rate was 44.1%, with an average attrition of 3.9 and 5.6%/year, respectively. It is concluded that elderly patients are high risk surgical candidates, yet the risk has decreased progressively because of improved techniques of medical and surgical management and myocardial preservation. This decreasing operative mortality rate provides evidence that when medical management of the elderly patient with severe angina fails, coronary artery bypass becomes a successful alternative.

Age Factors↗
PubMed1984

Influence of prednisolone on antipyrine and chloramphenicol disposition in rabbits.

A study was conducted to see the effect of 15- and 30-day corticosteroid therapy (prednisolone 0.25 mg/kg/day) on the metabolism of antipyrine and chloramphenicol in rabbits. Antipyrine and chloramphenicol were given to rabbits orally at doses of 20 and 50 mg/kg, respectively on days 0, 15 and 30 of prednisolone therapy. The half-life of antipyrine and chloramphenicol were significantly reduced (p less than 0.05) after 15 and 30 days of the corticosteroid therapy. It is concluded that this effect might be due to the induction of liver microsomal enzymes.

Animals↗
PubMed1984

Coronary artery bypass for unsuccessful percutaneous transluminal coronary angioplasty.

Of 518 consecutive patients undergoing percutaneous transluminal coronary angioplasty for 571 coronary lesions, 184 eventually underwent coronary artery bypass because of angioplasty failure. Delayed coronary bypass (1 week to 19 months) was done in 27 patients with no deaths. Immediate bypass was done in 87 patients with two deaths, both of which were caused by further dissection of the artery after angioplasty. Urgent bypass was required in 63 patients who were in unstable condition because of ischemia on the electrocardiogram (52 patients), unrelieved angina (57 patients), or hypotension (13 patients). There was one death in this group. In the remaining seven patients, urgent coronary bypass was done because of cardiac arrest (three deaths). Myocardial complications occurred in 23 of the 70 unstable patients, including the seven patients with cardiac arrest. There were only eight completed myocardial infarctions in the 70 unstable patients and a completed myocardial infarction rate of 11 of 184 (6.0%) overall. In the 10 patients in whom extracorporeal circulation was established within 25 minutes of myocardial insult, mortality and myocardial complications were completely avoided. The remaining patients in the urgent group were placed on cardiopulmonary bypass within 26 to 300 minutes (mean 82 minutes). Operative mortality (3.3%), completed myocardial infarction (6.0%), myocardial infarction in unstable patients (32.9%), postoperative hemorrhage (5.0%), and sternal problems (2.8%) were all significantly different from those in 3,500 consecutive coronary bypasses not following angioplasty, that were done in 1982.

Adult↗
PubMed1984

Brand versus generic prescribing: a perspective of the Indian cardiologists' viewpoint.

Pretested mail survey questionnaires consisting of four close-ended, six open-ended questions and an "anonymous prescribing" exercise were sent to 612 members of the Cardiological Society of India. This was done to assess their opinion regarding generic prescribing, to record the incidence of generic prescribing for digoxin and furosemide and to evaluate the extent of comprehension of novel terminology like bioequivalence, generic equivalence and therapeutic equivalence. The majority of the responders opted for brand prescribing and mentioned that substitution by a pharmacist was not acceptable. The reputation of the firm, availability and ease of remembering the name, cost and impact of medical representative were, in descending order, the reasons for the option of a specific brand name. The innovator's brand of digoxin (Lanoxin) was prescribed by 59% while 37% wrote the generic name. Lasix was the most often prescribed (77%) brand of furosemide. Comprehension of the novel terms was not related to years of practice or to the place of practice. The need for evaluation of brands encountered by the prescriber in future studies on brand versus generic prescribing has been emphasized.

Digoxin↗
PubMed1983

Unusual combination of total occlusion of left main coronary artery and heart failure with pulmonary hemosiderosis: case report.

A case of total occlusion of the left main coronary artery, congestive heart failure, and pulmonary hemosiderosis in a 54-year-old man is reported. Cardiac catheterization showed total occlusion of the left main coronary artery, subtotal occlusion of the right coronary artery, severely deranged hemodynamics, and an akinetic left ventricle except for a hypokinetic posterobasal segment. A radionuclide left ventricular performance study revealed an ejection fraction of 0.16 with diffuse biventricular hypokinesis and dilatation. Despite all the risk factors, the patient underwent a total of six saphenous vein grafts without perioperative or immediate postoperative complications.

Journal Article↗
PubMed1983

In vitro drug metabolism in humans with different liver diseases.

In vitro drug metabolism studies were carried out in 97 patients with liver disease. Drug-metabolizing enzymes (aminopyrine N-demethylase and bilirubin UDP-glucuronyl transferase) were estimated in livers obtained at the time of biopsy with a Menghini needle. The patients were divided into three groups depending on clinical, biochemical, radiologic, and histologic findings: (i) mild (non-cirrhotic portal fibrosis and extrahepatic portal vein obstruction), (ii) moderate (Budd-Chiari syndrome and amebic liver abscess), (iii) severe (acute hepatitis, chronic active hepatitis, and cirrhosis). Aminopyrine N-demethylase was decreased in all liver disorders as compared to ten control liver samples. Bilirubin UDP-glucuronyl transferase was significantly lower in all liver disorders except for amebic liver abscess and extrahepatic portal vein obstruction. Both the enzymes in (i) and (ii) groups were significantly higher than in group (iii). A significant correlation was obtained between the two enzymes.

Aminopyrine N-Demethylase↗