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Biomedical subjects

A J Bennett

Publications and source records attributed to A J Bennett.

At least 55 records · Page 3Linked to original sources
PubMed1993

Behavioral laterality in captive bonobos (Pan paniscus).

Behavioral laterality was studied in a captive group of 11 bonobos (Pan paniscus). In an observational method a significant left lateral bias in carrying and a right lateral bias in leading limb were found. Direction of lateral bias in carrying and leading limb was enhanced when subjects maintained a bipedal posture. Analysis of bimanual feeding behavior revealed a significant right-hand bias for eating when subjects were holding food with their left hand. In an experimental method a significant shift toward greater right-hand use was found when subjects were required to maintain a bipedal, rather than a quadrupedal, posture. There was no evidence of lateral bias for measures of face touching, self-touching, or gestures. The results are discussed in the context of previous reports of primate laterality.

Animals↗
PubMed1993

Survival at 15 to 18 years after coronary bypass surgery for angina in women.

BACKGROUND: Coronary bypass surgery in women is associated with lower survival than in men. We need to know whether this is because of patient-related factors and whether the lower survival is present in all subgroups of patients and for all time periods during which the surgery was performed. METHODS AND RESULTS: Using actuarial techniques, we determined the outcome of coronary bypass surgery performed for chronic stable and unstable angina in 1979 women and 6927 men. The operative mortality was 2.7% for women and 1.9% for men (P = .02). The higher operative mortality in women was seen in those with three-vessel disease or greater and abnormal left ventricular function (5.4% versus 2.8%, P = .009) and those with stable angina (2.6% versus 1.5%, P = .006). The 5-, 10-, 15-, and 18-year survival for women was 86 +/- 0.9%, 70 +/- 1.5%, 50 +/- 2.5%, and 37 +/- 6.4%, respectively, and for men, 88 +/- 0.4%, 73 +/- 0.7%, 54 +/- 1.2%, and 42 +/- 1.9%, respectively (P = .03). The lower survival in women compared with men was seen in those with three-vessel disease or greater and abnormal left ventricular function (at 10 years, 69 +/- 1.8% versus 73 +/- 0.8%, P = .005). At 15 years, the incidence of reoperation was 26 +/- 2.4% versus 28 +/- 1.2% and of myocardial infarction, 30 +/- 2.8% versus 32 +/- 1.3%, P = NS for either. The incidence of no angina or mild angina was 70% in women and 78% in men, P < .0001. The operative mortality and late survival of those operated on in different time periods for either women or men was not significantly different. Women were older (64 +/- 9.4 versus 61 +/- 9.9 years, P < .0001) and smaller (body surface area, 2.0 +/- 0.2 versus 1.7 +/- 0.2 m2, P < .0001), had a higher incidence of diabetes, systemic hypertension, and unstable angina, and had a smaller lumen of the left anterior descending coronary artery (1.7 +/- 0.4 versus 1.9 +/- 0.4 mm, P < .0001), right coronary artery, and diagonal arteries. More men were smokers, and men had a higher incidence of prior myocardial infarction, previous coronary bypass surgery, and extent of coronary disease and of abnormal left ventricular function. The Cox regression model of survival showed that independent risk factors for lower survival were older age, previous coronary bypass surgery, previous myocardial infarction, and diabetes. Sex was not an independent risk factor for poorer survival. CONCLUSIONS: Women have a higher operative mortality and lower long-term survival than men after coronary bypass surgery for angina. However, the differences are small, even if statistically significant. Importantly, patient-related factors and not sex are independent predictors of poorer survival. Therefore, coronary bypass surgery should not be delayed or denied to women who have the usual indications for surgery.

Actuarial Analysis↗
PubMed1992

Age and sex as factors influencing spontaneous exploration and object investigation by preadult rats (Rattus norvegicus).

This study examined developmental and sex differences in the exploratory and investigatory behaviors of Long-Evans rats (Rattus norvegicus). Littermate sextuplets were divided into sex-matched groups (at 30, 60, and 90 days of age) and were individually videotaped on 2 consecutive nights in an arena that contained stimulus objects. Multiple measures of locomotor exploration and object investigation increased significantly with age but were not influenced by sex. Older rats entered more quickly, were more active, spent more time in the arena, and spent more time investigating inanimate stimulus objects than did younger rats. Sex did not significantly affect most measures of open-field behavior; however, the data suggest that the sexes may begin to diverge by 90 days. These results suggest that preadult rats of both sexes are equipped early in development with similar strategies and repertoires for exploration and investigation.

Age Factors↗
PubMed1992

Medical futility. Committee on Bioethical Issues of the Medical Society of the State of New York.

The term futile is used in many different ways. It is therefore difficult to decide whether a procedure or treatment such as CPR or hemodialysis or blood transfusion would be futile in a given case. The AMA's guidelines on the appropriate use of DNR orders state that DNR decisions should be made openly. Institutions should have policies and physicians should elicit the patient's preferences about CPR. For physicians, the question is no longer whether we should discuss DNR orders with our patients; instead, the issue is how to do so with compassion and caring. Physicians should share with patients their judgment about what medicine can and cannot do. Then physicians must "make decisions about when to withhold or limit resuscitation openly" in honest and trusting conversation between doctor and patient. Often CPR is an exercise in futility. The medical profession should be vested with the authority to make futility decisions if they are the product of open discussion and shared deliberation between physician and patient, family, or surrogate. Rationing, triage, and medical futility in relation to AIDS patients require careful deliberation and consideration. What was considered medically futile five years ago for an AIDS patient may be appropriate care nowadays. The need for appropriate use or non-use of life-sustaining therapy for the elderly, the terminally ill, patients with AIDS and other incurable illnesses is evident to patients, health care providers, policy makers, and the public. CPR should only be administered if it is expected to confer lasting benefit to the patient. However, if 10% of elderly patients benefit from CPR in the case of out-of-hospital cardiac arrest, how can one consider this procedure futile? Although communication between physician and patient about difficult treatment limitation decisions has markedly improved in recent years, it remains a problem, largely because open dialogue with patients and families about futility is a demanding emotional and intellectual task. The medical profession is charged with setting standards for the proper implementation of judgments regarding futility.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Resuscitation↗
PubMed1989

A case of hereditary combined deficiency of complement components C6 and C7 in man.

Immunological investigation of a patient presenting with candidiasis and toxoplasmosis revealed a combined deficiency of C6 and C7. Deficiency of C6 was total, but small amounts (less than 1 microgram/ml) of apparently normal C7 were present in the serum. All family members (three sibs and both parents) were heterozygous for the combined deficiency. This is only the second reported case of combined homozygous deficiency of the closely linked and immunochemically similar proteins C6 and C7, and only the third kindred in which this defect has been demonstrated.

Adult↗
PubMed1988

Factors regulating the secretion of lysophosphatidylcholine by rat hepatocytes compared with the synthesis and secretion of phosphatidylcholine and triacylglycerol. Effects of albumin, cycloheximide, verapamil, EGTA and chlorpromazine.

1. The synthesis and secretion of glycerolipid by monolayer cultures of rat hepatocytes was measured by determining the incorporations of [3H]glycerol, [3H]oleate and [14C]choline and by the absolute concentration of triacylglycerol. 2. The presence of albumin in the medium stimulated the accumulation of lysophosphatidylcholine in the medium by 11-13-fold. 3. Cycloheximide did not significantly alter the accumulation of lysophosphatidylcholine. 4. This process was particularly sensitive to inhibition by chlorpromazine and verapamil, compared with the secretion of triacylglycerol and phosphatidylcholine. By contrast, it was relatively less sensitive to EGTA. 5. It is suggested that intracellular Ca2+ may be important in the production of lysophosphatidylcholine, which then accumulates in the medium by binding to albumin. In vivo this lysophosphatidycholine may be a means of delivering choline and polyunsaturated fatty acids to other organs.

Albumins↗