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Biomedical subjects

M Alam

Publications and source records attributed to M Alam.

At least 271 records · Page 15Linked to original sources
PubMed1980

Hemolytic anemia with porcine xenograft aortic and mitral valves.

Severe hemolytic anemia occurred in a 30-year-old man 12 months after insertion of 23 mm and 31 mm Hancock porcine xenografts in the aortic and mitral positions respectively. At catheterization the mean transvalvular aortic xenograft gradient was 63 mm Hg, and at operation the stents of the aortic xenograft were bent inward, causing a supravalvular secondary orifice obstruction. One year later the patient has only subclinical hemolysis consistent with Björk-Shiley aortic and mitral prostheses.

Adult↗
PubMed1979

M mode and two dimensional echocardiographic features of porcine valve dysfunction.

The echocardiographic features are presented of degeneration of nine glutaraldehyde-fixed porcine xenograft valves implanted in eight patients. These features occurred 11 to 68 months after implantation and were correlated with surgical and necropsy findings. Acute bacterial endocarditis was present in two patients, and had been successfully treated medically in three other patients 47 to 52 months before valve degeneration was recognized. The valve was severely thickened in four patients and in two of the four the thickening was associated with a significant hemodynamic transvalve gradient. M mode echocardiography demonstrated increased thickness and loss of the cusp detail. In five patients severe regurgitation due to a tear in one or more cusps developed in the the valve in the mitral position. M mode echocardiography in all five patients revealed on the valve systolic or diastolic fluttering echoes, or both. The two dimensional echocardiogram demonstrated thickened cusps with systolic protrusion of the leaflets into the left atrium. Both modes of echocardiography were of valve in identifying degeneration of the porcine xenograft valve.

Adolescent↗
PubMed1979

Dinoflagellate sterols I: Sterol c omposition of the dinoflagellates of Gonyaulax species.

The sterol composition of five species of dinoflagellates of the family Gonyaulacaeae (Div. Pyrrhophyta) were examined. All the five species (Gonyaulax acatenella, G. tamarensis, G. catennela, G. washing-tonesis, and G. polyedra) were found to contain 4 alpha-23,24(R)-trimethyl-5 alpha-cholest-22-en-3 -ol (dinosterol) and cholesterol as major sterols.

Cholesterol↗
PubMed1979

Diagnostic value of visualization of the right ventricle using thallium-201 myocardial imaging.

The diagnostic significance of visualizing the right ventricle on thallium-201 myocardial perfusion scans (T-scan) at rest was studied in 53 patients. In 33 patients the right ventricle was visualized clearly on the T-scan (group A). Hemodynamic evidence of right ventricular hypertension with systolic pressure greater than or equal to 30 mmHg was present in 28 of 33 (85%) of these patients. Right ventricular volume overload with left-to-right shunt greater than 2:1 was present in three patients. Other tests were diagnostic for right ventricular enlargement and or pulmonary hypertension as follows: chest x-ray (58%), echocardiogram (36%) and electrocardiogram (15%). In an unselected group of 20 patients (group B) where resting T-scan did not show visualization of the right ventricle, the right ventricular systolic pressure was less than 30 mm Hg in all. The other noninvasive tests did not reveal presence of right ventricular hypertrophy or enlargement. T-scan appears to be a useful and sensitive test in detecting right ventricular pressure or volume overload compared with other noninvasive tests. This may be useful in detection of patients with right ventricular hypertrophy or enlargement secondary to pulmonary hypertension or other causes.

Adult↗
PubMed1979

Echocardiographic features of mitral obstruction due to bacterial endocarditis.

We describe a patient with mitral valvular obstruction due to vegetative endocarditis. The diagnosis was made before surgery by M-mode and two-dimensional echo-cardiograms, which revealed a mass of echoes obstructing the mitral orifice. This was confirmed subsequently at surgery. Both modes of echocardiography are of value in the noninvasive diagnosis of mitral valvular obstruction due to vegetative endocarditis, a condition which may be amenable to surgery for valvular replacement.

Aged↗
PubMed1978

Echocardiographic diagnosis of left ventricular hypertrophy.

Echocardiograms were obtained on 27 adults with electrocardiographic criteria of left ventricular hypertrophy (LVH) to determine how echocardiograms might best identify LVH. Both the left ventricular (LV) posterior wall thickness and interventricular septal thickness were found by echocardiography to be increased (greater than or equal to 12 mm) in only 13 of 27 patients (48%) with LVH. The LV was dilated (greater than or equal to 58 mm) in the absence of posterior wall thickening in 9 of 27 patients (33%). The LV mass, estimated from standardly measured dimensions, was increased (greater than 200 g) in 21 of 27 patients (78%) and when measurements were made by the Penn method, mas was increased in all patients. These observations indicate that the echocardiographic estimation of LV mass is a more sensitive indicator of LVH than LV posterior wall and septal thickness. Since LVH is defined as an increased mass of LV muscle, these observations are consistent with this fundamental definition of left ventricular hypertrophy.

Adult↗
PubMed1975

Plasma hormones and pituitary luteinizing hormone in the rat during the early stages of pregnancy and after post-coital treatment with tamoxifen (ICI 46,474).

Plasma levels of oestradiol-17beta, progesterone and luteinizing hormone (LH) and pituitary levels of LH have been measured during the first 6 days of pregnancy, in normal rats and in rats receiving two doses of Tamoxifen (trans-1-(rho-beta dimethylamino-ethoxyphenyl)-1-2-diphenylbut-1-ene) on day 2 of pregnancy. In normal rats oestradiol rose strongly from early on day 3 to reach a peak concentration between 22.00 h on day 3 and 08.00 h on day 4. Progesterone concentrations rose from day 2 to reach peak values on day 3-4. In animals in which implantation was delayed 20-24 h by administration of Tamoxifen (0.1 mg/kg) orally on day 2 the increased level of plasma oestrogen was also delayed by 20 h. A higher dose of Tamoxifen (0.2 mg/kg) on day 2, which prevented implantation, completely eliminated the increase in plasma oestradiol. Neither dose of Tamoxifen affected the levels of progesterone. In both normal rats and rats treated with 0.1 mg Tamoxifen/kg, plasma LH levels declined by day 3 while pituitary levels rose steadily. There was no detectable change in either plasma or pituitary LH levels, accompanying the increase in plasma oestradiol in the normal rats. In animals receiving Tamoxifen (0.2 mg/kg), plasma LH increased to a maximum by day 4 while levels of pituitary LH decreased. The results show that the oestrogen "surge" of early pregnancy, occurs normally about midnight on day 3 and not late on day 4 as previously thought. It is considered that the plasma oestradiol peak in early pregnancy results from an increased release of FSH rather than an increased release of LH. Tamoxifen may owe part of its antifertility action to a capacity to inhibit the synthesis of oestradiol from progesterone.

Adrenalectomy↗