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Biomedical subjects

M Arnold

Publications and source records attributed to M Arnold.

At least 199 records · Page 11Linked to original sources
PubMed1982

Topical cardiac cooling by recirculation: comparison of a closed system using a cooling pad with an open system using a topical spray.

Topical cardiac cooling plays an important part in maintaining myocardial hypothermia during cardiac operations under hypothermic cardioplegic arrest. We have compared two systems of topical cooling in which the cooling fluid is recirculated. In one system the cold fluid circulates through a sealed plastic cooling pad wrapped around the heart; in the other it is sprayed over the surface of the heart. In dogs undergoing 60 minutes of hypothermic cardioplegic arrest, the cooling pad was ineffective: it did not adequately cool the anterior left ventricular wall or the interventricular septum. Under the same conditions, the spray system produced myocardial temperatures 6 degrees to 12 degrees C lower than the cooling pad system. In limited clinical tests, the cooling pad was unable to sustain overall myocardial hypothermia and there was difficulty in maintaining contact between the heart and the pad during coronary operations. Since the topical spray can maintain profound global myocardial hypothermia regardless of the position of the heart, we conclude that it is superior to the cooling pad system.

Adult↗
PubMed1982

Coronary artery bypass in women: long-term survival.

During a 6-year period ending December, 1976, 385 female patients underwent coronary artery bypass at the Mid-America Heart Institute. This group constituted 14.6% of the total experience. The operative (thirty day) mortality was 1.3%, which is not significantly greater than that experienced by male patients operated on concurrently. A total follow-up of 2,015 patient-years was obtained. The incidence of nonfatal acute myocardial infarction was 2.0 per 100 patient-years of follow-up, and the incidence of repeat coronary artery bypass was 0.8 per 100 patient-years. The actuarial survival was 90% at 5 years and 75.3% at 10 years. Of the 46 deaths (early or late), 58.7% were cardiac in nature. Although the absolute survival of women is as good as that observed in men, the female patients did not achieve the expected survival pattern of a matched (for age and sex) general population as is observed in our male patients undergoing coronary artery bypass. These results obtained with coronary artery bypass justify the use of similar criteria for the application of this therapy in men and women.

Actuarial Analysis↗
PubMed1982

Normal survival curve after coronary artery bypass.

A consecutive series of 2,628 patients subjected to isolated coronary artery bypass have had follow-up for a total of 13,915.5 patient-years. The number of patients surviving without angina decreased from 81% at one year to 36.9% at nine years after operation. Nonfatal myocardial infarction occurred at a rate of 3.1% per year, and the incidence of repeat coronary artery bypass was approximately 1% per year. The ratio of the five-year actuarial survival to that expected for a normal population, matched by age and sex, was 1.03 for single vessel disease, 1.00 for double vessel disease, and 1.00 for triple vessel disease. The survival ratio at ten years postoperatively was 1.13, 0.99, and 0.85 for single, double, and triple vessel disease, respectively. Cardiac causes accounted for 44.4%, 68.9%, and 65.7% of deaths in patients with single, double, and triple vessel disease, respectively.

Adult↗
PubMed1982

Identification of two granulocyte/macrophage colony-stimulating factors from porcine leukocyte cultures.

Granulocyte/macrophage colony-stimulating factors (CSF) were found in large-scale serum-free cultures of porcine blood leukocytes. The factors were concentrated from the conditioned culture medium of Concanavalin A-stimulated leukocytes using ammonium sulfate salting-out fractionation. The protein precipitate at 45-90% salt saturation contained two CSF types upon gel filtration on Sephadex G-100: One type was found to be active on mouse, but not on human bone marrow stem cells and had an apparent molecular mass of 85 000-100 000 Da; the other of about 40 000-45 000 Da stimulated both mouse and human bone marrow stem cells.

Animals↗
PubMed1982

Myocardial revascularization: results relative to extensiveness.

We analyzed 13,788 patient-years of follow-up of 2,628 consecutive patients who had had primary isolated coronary artery bypass. We then assessed late results relative to the number of coronary artery bypasses done. There were no significant differences in the incidence of survival, angina-free status, nonfatal acute myocardial infarction, repeat coronary artery bypass, or cardiac deaths relative to the number of bypasses in patients with single or double vessel disease. Patients with three vessel disease had significantly increased incidence of angina-free status and significantly decreased incidences of nonfatal acute myocardial infarctions and repeat coronary artery bypass with increasing number of bypasses performed. In this study, we found no advantage in performing increasing numbers of bypasses in patients with single or double vessel disease, but there was definitely such an advantage in patients with triple vessel disease.

Coronary Artery Bypass↗
PubMed1981

Plasma melatonin increases during exercise in women.

Melatonin was measured in plasma of seven women volunteers before and after serial acute submaximal exercise tests performed during the course of a two-month, progressive endurance training program. Plasma melatonin increased during all exercise sessions and declined towards baseline values when re-measured thirty minutes after completion of each exercise. This finding indicates that vigorous physical activity elicits transient increases in plasma melatonin in both sedentary and trained women.

Adolescent↗
PubMed1981

[Extragenital changes caused by intake of hormonal contraceptives--marginal periodontium (author's transl)].

Degree of inflammation, temperature, and partial oxygen pressure in the marginal periodontium of front teeth were tested in 22 women, prior to the intake of hormonal contraceptives as well as after periods of two, four, and six months. Hormonal contraceptives were found to result in higher blood flow through the mucous membrane and in slight increase of inflammation. Change of most parameters, in the wake of hormonal contraceptives, was offset in the adaptation phase. Gingival change due to contraceptives was found to be of minor importance, when compared to other risks, such as gravidity.

Adolescent↗
PubMed1980

Effects of caffeine on anterior pituitary and thyroid function in the rat.

We studied the effects of acute, intraperitoneal administration of caffeine on serum thyrotropin (TSH), growth hormone, prolactin, thyroxine and 3,3',5-triiodothyronine in rats. Caffeine lowered serum TSH and GH in a dose-dependent manner with ED50 values of 30 and approximately 50 mg/kg, respectively. TSH levels were depressed 1 to 6 hr after injection and correlated with serum caffeine levels greater than 20 micrograms/ml. The decrease in serum TSH was followed by decreases in serum 3,3',5-triiodothyroxine and thyroxine 4 hr after caffeine administration. Theophylline and theobromine had effects similar to those of caffeine on hormone levels. Caffeine did not significantly affect hormone secretion when incubated directly with rat pituitaries in vitro. Administration of antisomatostatin antiserum to rats blocked the inhibitory effects of caffeine on serum GH levels, suggesting that caffeine inhibits GH and TSH secretion by releasing hypothalamic somatostatin.

Animals↗