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Biomedical subjects

H I Miller

Publications and source records attributed to H I Miller.

At least 127 records · Page 7Linked to original sources

Chronic caffeine intake by rat dams during gestation and lactation affects various parts of the neonatal brain.

Timed-pregnant rats were randomly divided into 2 groups on day 13 of gestation. Group 1 received a 20% protein diet. Group 2 was pair-fed to group 1 with a 20% protein diet containing caffeine (1 mg/100 g body weight). At parturition, the dams of each group were continued on their respective diets until day 22 postpartum. At the time of weaning (day 22), only male rats were continued in the study. At this time, rats from both groups were fed the control diet containing 20% protein. On day 57 and 58, rats were killed, the brains divided into six areas, and DNA, RNA and protein contents were measured. In certain areas of the brain, weight, cholesterol, DNA, RNA and protein contents were different even long after returning to the caffeine-free control diet. The present study demonstrates that even if a relatively small amount of caffeine is taken during gestation and lactation, a time during which the growth rate is greater than in any other period of life, certain areas of the brain may be affected. These findings suggest that future central nervous system impairment may be expressed later in life in these offspring.

Animals↗

Primary angiosarcoma of the heart detected by two-dimensional echocardiography.

A 24-year-old woman with a history of syncope and recurrent hemopericardium was urgently hospitalized with signs of severe right-sided heart failure. Two-dimensional echocardiography demonstrated a largedechogenic mass that compressed the right ventricle. The patient was referred for emergency surgery. A large angiosarcoma originating in the right atrium was excised, and the patient was treated with chemotherapy. The role of echocardiography in the detection of cardiac tumors is discussed.

Adult↗

Aneurysm of the sinus of Valsalva with coexistent coronary atherosclerosis.

Unruptured aneurysm of the sinus of Valsalva coexistent with extensive coronary atherosclerosis was noted in a 65-year-old man. He underwent transaortic patch repair of the aneurysm and quadruple aortocoronary bypass. The essential features of adequate management of this association are discussed.

Aged↗

Mitral obstruction in bacterial endocarditis.

Mitral obstruction due to a large vegetation of acute Streptococcus viridans endocarditis occurred in a 47 year old man. Serial echocardiography documented the rapid growth of the vegetation and its haemodynamic effects. Emergency mitral valve replacement was performed too late to reverse the course of fatal septic shock.

Echocardiography↗

Apical hypertrophic cardiomyopathy: evaluation by noninvasive and invasive techniques in 23 patients.

Over a 3 year period we evaluated 23 patients (16 men, seven women) with apical hypertrophic cardiomyopathy by noninvasive and invasive methods. Sixteen patients had chest pain. In 17, results of cardiovascular examination were normal. The electrocardiogram showed precordial inverted T waves in all patients and these were of mild-to-moderate amplitude (less than 10 mm) in 18 and giant (greater than 10 mm) in five. M mode echocardiography revealed a typical pattern of contraction and relaxation in the apical region of the left ventricle that was associated with significant hypertrophy. These findings were confirmed by two-dimensional echocardiography. Systolic anterior motion of the mitral valve was not observed nor was there any evidence of obstruction of the left ventricular outflow tract. Results of Doppler echocardiographic study of the mitral and aortic flow were normal in all patients but one who had mild mitral insufficiency. Radionuclide studies of 14 patients revealed a mean left ventricular ejection fraction of 66 +/- 6% (range 55% to 79%), with normal left ventricular contraction in all patients but two with apical hypokinesis. In all six patients who underwent catheterization a characteristic appearance of the left ventricle at end-systole as well as abnormal end-diastolic contour were noted on the left ventricular angiogram, but the "ace of spades" configuration was seen in only one. We conclude that the 23 patients studied form a homogeneous group of individuals with nonobstructive apical hypertrophic cardiomyopathy, which differs in many respects from cardiomyopathies reported by other investigators.

Adult↗

Effects of chronic caffeine ingestion on growth and myocardial function.

Experiments were conducted to determine whether chronic caffeine consumption during early growth and development affected cardiac performance and development of adipose tissue. Dams were fed a nutritionally complete diet with or without the addition of 10 mg/kg caffeine during lactation. After weaning, the pups were maintained on this diet until they were sacrificed at 88 days of age. Body weight at the time of sacrifice was comparable for both groups. The hearts from caffeine-fed animals were significantly (P less than 0.05) larger based on both dry and wet weights although the dry weight/wet weight ratios were similar. Ventricular function curves were generated on each heart using an isolated working heart preparation. The isolated hearts of caffeine-fed rats exhibited a significant reduction in cardiac output, stroke volume, mean aortic pressure, and estimated myocardial work when compared to controls. The rats fed caffeine had greater plasma triglyceride levels with no significant differences in adipocyte size or number in the epididymal and perirenal depots. It is concluded that chronic caffeine intake from birth may alter cardiac function of the offspring.

Adipose Tissue↗

Intermittent poppet dislodgment in a Braunwald-Cutter prosthesis: noninvasive diagnosis and successful surgical treatment.

A 65 year old patient had his mitral and aortic valves replaced with two Braunwald-Cutter prostheses in 1973. Seven years later, he presented with intermittent aortic insufficiency demonstrated by echocardiography, fluoroscopy and angiography. At emergency surgery, the occluders (poppets) of both prostheses were found within the left ventricular cavity. The valves were excised and replaced with Björk-Shiley prostheses and the patient recovered. Aortic occluder escape is rare and usually fatal. Mitral occluder escape of the Braunwald-Cutter prosthesis has not been described previously.

Aged↗

Failure of balloon membranotomy of the inferior vena cava.

A young woman with membranous obstruction and coarctation of the inferior vena cava is described. A balloon membranotomy was performed with a transient improvement. Three months later massive thrombosis of the inferior vena cava developed. It appears that balloon membranotomy alone is contraindicated in the presence of both stenosis and membranous obstruction of the inferior vena cava.

Adult↗

Effect of burn shock on myocardial function in guinea pigs.

The effect of burn shock on myocardial function was studied using an isolated working heart preparation. Guinea pig hearts were studied 2-, 4-, and 8-hr following burn injury as well as in time-matched controls. The hearts were excised from both burned (35% body surface area) and unburned unresuscitated animals, and ventricular function curves were generated on each heart. The 4- and 8-hr postburn hearts, particularly the 4-hr group, exhibited depression in cardiac output, stroke volume, coronary flow, peak systolic pressure, mean aortic pressure, estimated myocardial work, stroke work, and oxygen consumption when compared to controls. The ventricular function curve for the 4-hr postburn hearts was shifted to the right indicating a decrease in contractility, which complements a decrease seen in compliance. These pronounced changes seen in the 4-hr postburn hearts were not observed 2 hr after burn injury. The data suggest that intrinsic myocardial function following burn injury is depressed and the degree of dysfunction is influenced by the time from thermal injury.

Animals↗