Predictors of Long-Term Social Compatibility in Rhesus Macaques (Macaca mulatta) Housed in Research Settings.

Social housing improves the well-being of monkeys in research settings; however, little is known about factors influencing the long-term stability of established, full-contact pairs. Archival data were examined to determine whether sex, age, weight, duration pair housed, familiarity, social interruptions, room changes, or sedation events predicted eventual separation of pairs for social incompatibility (n = 80) or for nonsocial reasons (e.g., research or health needs) (n = 1143). Using a logistic regression model (Wald Χ2(8) = 42.325, p < .001), three significant factors were identified. Pairs in which partners had known prior familiarity in group housing were less likely to experience social incompatibility (p = .034). Pairs housed together longer (p < .001) and who staff had temporarily separated through the placement of a cage divider to reduce physical contact were more likely to require permanent separation for social incompatibility (p < .001); additional analysis revealed that dividers were often placed for social reasons, suggesting early signs of social instability. Findings may be useful for primate caregivers when making decisions about managing social partners.

Improvement of walking speed prediction by accelerometry and altimetry, validated by satellite positioning.

Activity monitors based on accelerometry are used to predict the speed and energy cost of walking at 0% slope, but not at other inclinations. Parallel measurements of body accelerations and altitude variation were studied to determine whether walking speed prediction could be improved. Fourteen subjects walked twice along a 1.3 km circuit with substantial slope variations (-17% to +17%). The parameters recorded were body acceleration using a uni-axial accelerometer, altitude variation using differential barometry, and walking speed using satellite positioning (DGPS). Linear regressions were calculated between acceleration and walking speed, and between acceleration/altitude and walking speed. These predictive models, calculated using the data from the first circuit run, were used to predict speed during the second circuit. Finally the predicted velocity was compared with the measured one. The result was that acceleration alone failed to predict speed (mean r = 0.4). Adding altitude variation improved the prediction (mean r = 0.7). With regard to the altitude/acceleration-speed relationship, substantial inter-individual variation was found. It is concluded that accelerometry, combined with altitude measurement, can assess position variations of humans provided inter-individual variation is taken into account. It is also confirmed that DGPS can be used for outdoor walking speed measurements, opening up new perspectives in the field of biomechanics.

Beneficial cumulative role of both nitroglycerin and dobutamine on right ventricular systolic function in congestive heart failure patients awaiting heart transplantation.

End-stage idiopathic dilated cardiomyopathy or ischemic heart disease usually present with very low cardiac output and severe ventricular dysfunction which may require pharmacological support before heart transplantation. Right ventricular ejection fraction might be an important factor of functional capacity and survival in congestive heart failure. In order to test the immediate response of right ventricular hemodynamic parameters to nitroglycerin and dobutamine usually used to treat severe left ventricular dysfunction, we studied 17 congestive heart failure patients (15 men, two women; mean age 55 +/- 13 years) with end-stage idiopathic dilated cardiomyopathy (n = 10) or end-stage ischemic heart disease (n = 7), left ventricular ejection fraction < 35% (mean 22 +/- 8%), and sinus rhythm. A well validated thermodilution technique using a dedicated catheter with a fast catheter-computer response, permitting instantaneous measurements of right ventricular ejection fraction, was used. Right ventricular hemodynamic parameters were recorded at baseline, after an intravenous bolus injection of 3 mg nitroglycerin and after an intravenous infusion of dobutamine administered after nitroglycerin until normalization of cardiac index or a maximal dose of 15 micrograms/kg/min. Pulmonary artery mean pressure significantly decreased after nitroglycerin (43 +/- 9 mmHg at baseline vs. 31 +/- 10 mmHg after nitroglycerin, P < 0.0001) and did not subsequently change after dobutamine (32 +/- 10 mmHg after dobutamine, ns). Cardiac index was not affected by nitroglycerin (1.7 +/- 0. l/min/m2 at baseline vs. 2.0 +/- 0.3 l/min/m2 after nitroglycerin, ns), but dramatically increased after dobutamine (3.0 +/- 1.0 l/min/m2 after dobutamine, P < 0.0001). Concomitantly to the changes of these two parameters, right ventricular ejection fraction progressively increased (14 +/- 8% at baseline vs. 20 +/- 10% after nitroglycerin (P < 0.0006) vs. 28 +/- 13% after dobutamine (P < 0.0001)). Progressive increase of right ventricular ejection fraction after administration of nitroglycerin followed by administration of dobutamine suggests the beneficial cumulative role of both medications on right ventricular systolic function in severe congestive heart failure.

[Irreversible auriculo-ventricular block of viral origin]. / Bloc auriculo-ventriculaire irréversible d'origine virale.

Transitory disturbances of atrioventricular conduction are an usual feature of the acute phase of viral myocarditis. In contrast, the onset of complete heart block is rarer. The authors report a case of permanent heart block of progressive onset in a context of infectious mononucleosis in a 29-year-old male, requiring fitting with a permanent pacemaker. A long term follow-up visit confirmed the irreversible nature of the conduction disturbance.

[Myocardial infarction caused by thrombosis of the common trunk of the left coronary artery without collateral circulation. Treatment by intra-aortic counterpulsation and subsequent heart transplantation]. / Infarctus du myocarde par thrombose du tronc commun de la coronaire gauche sans circulation de suppléance. Traitement par contrepulsion intra-aortique puis greffe cardiaque.

The authors report the case of an acute anterior myocardial infarction due to occlusion of the left main coronary artery without a collateral circulation. The patient survived after intraaortic balloon pumping followed by cardiac transplantation.

[Relationship between right ventricular ejection fraction and pulmonary pressure in man]. / Relation entre fraction d'éjection ventriculaire droite et pression artérielle pulmonaire chez l'homme.

This clinical study analysed the changes in right ventricular ejection fraction induced by changes in right ventricular afterload using a new thermodilution catheter linked to a rapid response computer which allowed instantaneous measurements of the right ventricular ejection fraction. The first group comprised 16 patients referred for coronary angioplasty with single vessel disease (isolated proximal stenosis of one of the two main branches of the left coronary artery) and a normal left ventricular ejection fraction (> or = 55%) and mean pulmonary artery pressure of < 25 mmHg: right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after 60 seconds' coronary occlusion with the balloon catheter in order to assess the effects of the reactional increase in afterload on the right ventricular ejection fraction. The second group comprised 11 patients with dilated primary cardiomyopathy with decreased left ventricular ejection fraction (< 50%) and mean pulmonary artery pressure > or = 25 mmHg: the right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after intravenous trinitrin (performed to evaluate the pulmonary reaction to vasodilators) in order to analyse the effects of the reduction of afterload on right ventricular ejection fraction. Negative linear correlations were observed between the right ventricular ejection fraction and mean pulmonary artery pressure under basal conditions (r = -0.72; p < 0.005) and between the right ventricular ejection fraction and mean pulmonary artery pressure after changing the conditions of afterload (r = -0.82; p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative effects of oral molsidomine and nifedipine on methylergometrine-induced coronary artery spasm.

Twelve consecutive patients (10 men and 2 women, mean +/- standard deviation age 49 +/- 9 years) with chest pain, angiographically normal coronary arteries and coronary artery spasm documented by methylergometrine testing received a single oral dose of molsidomine (4 mg) or nifedipine (10 mg) in a randomized, double-blind, crossover fashion at a 24-hour interval. Coronary artery spasm was documented during coronary angiography in 6 patients (left anterior descending artery, 3; right coronary artery, 2; left circumflex, 1). In the remaining 6 patients, coronary artery spasm was documented by a positive methylergometrine test performed at the bedside, which provoked ST-segment elevation in the inferior (n = 3), anterior (n = 1) or lateral (n = 2) leads. Ninety minutes after administration of the study medication, methylergometrine testing was performed at the bedside, using incremental doses of up to 0.4 mg of methylergometrine. After molsidomine, 10 patients (83%) had a negative and 2 had a positive test; after nifedipine, 9 patients (75%) had a negative and 3 a positive test. Only 1 patient had a methylergometrine test that remained positive after either molsidomine or nifedipine. Therefore, molsidomine appears as effective as nifedipine in suppressing methylergometrine-induced coronary artery spasm in patients with variant angina. In addition, patients not responding to 1 of the study medications may respond to the other.

[Relations of the duration of pre-existing angina pectoris, collateral circulation and left ventricular function after isolated coronary occlusion with or without myocardial infarction]. / Interrelations entre durée d'angine de poitrine préexistante, circulation de suppléance et fonction ventriculaire gauche après occlusion coronaire isolée avec ou sans infarctus myocardique.

The aim of this retrospective study was to determine the relationship between the duration of preceding angina pectoris, collateral circulation and left ventricular function after isolated coronary occlusion with or without myocardial infarction. Coronary angiography of 138 consecutive patients showed isolated and complete occlusions of the left anterior descending (58 patients) or right coronary artery (80 patients). One hundred and four patients had myocardial infarction with (Group A, n = 21) or without (Group B, n = 83) preceding angina pectoris and 34 had angina without myocardial infarction (Group C). The left ventricular ejection fraction was measured by ventriculography in the 30 degrees right anterior oblique projection. The collateral circulation was assessed by coronary angiography and evaluated as follows: no flow or flow limited to collateral branches (subgroup 1) and partial or complete filling of the epicardial arterial segment (subgroup 2). In the global population the left ventricular ejection fraction was higher and the duration of preceding angina pectoris was longer in the subgroups with a well developed collateral circulation. There was no difference in ejection fraction between Groups A and B (presence of myocardial infarction), on the other hand, within each of the groups, a good collateral circulation (subgroup 2) was associated with a significantly higher ejection fraction. Group C (without infarction) patients had better ejection fractions than Groups A or B, especially when the collateral circulation was poorly developed. Within Group C, the quality of the collateral circulation did not seem to affect the ejection fraction. The left ventricular ejection fraction is lower in patients with isolated coronary occlusion and myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)