Animal mortality

About: Animal mortality is a research topic. Over the lifetime, 526 publications have been published within this topic receiving 14887 citations.

Survival analysis of lambs using Cox’s proportional hazards’ modeling and Kaplan-Meier method

Abstract: The present research was conducted on 1633 Polish Merino lambs reared in two herds from the Pomerania and Kujawy region. The data regarding the collapse date of lambs aged up to 56 days underwent scrutiny. In order to indicate those factors which influence lamb mortality, the Cox’s proportional hazards modeling was utilised. By means of backward selection, the variables which were significantly linked with lamb mortality, i.e. type and year of lamb’s birth, were determined. In addition, for the variables selected, the survival curves were established using the Kaplan-Meier method. The calculated arithmetic mean indicates that the average collapse time occurred on days 14 to 15 of a lamb’s life. It was concluded that approximately 25% of the collapses took place by the third day of life. Four subsequent days of a lamb’s life proved critical in lamb rearing. Altogether, 50% of collapses were recorded in the first week of a lamb’s life. The escalation of collapses in the first week of a lamb’s life is also indicated by the survival curves established applying the Kaplan-Meier method. The survival curves indicate lower survival among twins than lambs born as a result of multiple pregnancies. The probability of survival of a lamb up to 56 days old from a single pregnancy was 0.915, whereas for a twin-born lamb it was 0.825.

Differential Effects of Furnidipines’ Metabolites on Reperfusion-Induced Arrhythmias in Rats In Vivo

Abstract: We previously established that furnidipine (FUR) and oxy dihydropyridines prevent rats mortality by strong reduction of the lethal arrhythmias in reperfusion Therefore we decided to study the influence of three main metabolites (M-2, M-3, M-8) of FUR on ischemia-and reperfusion- induced arrhythmias and hemodynamic parameters in rat model to examine their independent activity The metabolites (M-2, M-3, M-8) were given orally 20 mg/kg (24 and 1 h before ischemia) Mortality was significantly diminished in M-2 and M-3 treated groups with M-3 preventing animal mortality entirely All three examined substances significantly reduced the duration and incidence of ventricular fibrillation (VF) with M-3, once again, completely preventing VF Moreover, only M-3 significantly decreased the duration of ventricular tachycardia but had no influence on their incidence Through the occlusion and reperfusion periods, M-2 and M-3 were markedly less hypotensive than M-8 and did not influence on heart rate We conclude that two tested metabolites of FUR, M-3 and M-2 exhibited the most pronounced anti-arrhythmic effect being at the same time the most normotensive and therefore caused the most beneficial effects

Effect of Selective Lymphoid Ablation on Rat Cardiac Allograft Survival

Abstract: Palladium-109-hematoporphyrin (Pd-H) contains a β-emitting isotope which when concentrated in the reticuloendothelial system causes total lymphoid and central bone marrow ablation. There is full recovery of tissue and blood cellularity within 60 days of its administration. A sublethal dose of Pd-H with a short course of rabbit antirat lymphocyte globulin results in specific tolerance to rat heart allografts across a minor histocompabihty barrier and significant prolongation of heart allografts across a major histocompatibility difference. Specific tolerance to donor strain was demonstrated by the acceptance of Fisher skin or heart by long-term Lewis recipients carrying old Fisher hearts (over 150 days) while they rapidly rejected ACI skin or heart allografts. The systemic irradiation with Pd-H in this study is as effective in immunosuppression as 800 rad total body irradiation and leads to no animal mortality.

Atherosclerosis vulnerable plaque animal model and method for establishing the same

Abstract: The invention relates to an atherosclerosis vulnerable plaque animal pattern and a building method thereof. The atherosclerosis vulnerable plaque animal pattern is characterized by the following steps: an experimental vessel is separated by a surgery method, blood at two ends of the vessel is blocked by a vessel clamp, the blood in the vessel is drained, and then liquid nitrogen is injected in the vessel for the endothelium freezing injury operation, high fat diet is combined for feeding, at last, the endothelium freezing injury operation is performed again for exciting the vulnerable plaque, and the atherosclerosis vulnerable plaque animal pattern is successfully built through the verification of results of pathology, electron microscope, immunohistochemistry, RT-PCR, Western blot, and the like. The animal pattern can better simulate the characteristics of the vulnerable plaque of the human, and has the advantages of simple pattern making operation, low pattern making cost, short pattern forming time, little operation hurt, serious narrow degree, high plaque breaking rate, low animal mortality rate, easy duplication, high controllability, and the like, thereby being very favorable to the medicine development of the plaque stabilizing therapy and the experimentation of the cardiovascular and cerebrovascular diseases, and having popularization and application values.

Animal Saturation Diving At Simulated Depths Of 50 And 60 Feet: Description Of Operation And Environment.

Abstract: : Two simulated saturation dives were conducted to monitor the physiological and biochemical responses of a model animal system to long-term diving in compressed air. The dives were performed at 50 and 60 feet of sea water for 60 and 36 days, respectively. Mean chamber CO2 was 0.42% and 0.33% surface equivalent concentration for the 50- and 60-foot dives, respectively. Mean chamber O2 was .51 ata and .58 ata for the 50- and 60-foot dives. No significant animal mortality was noted in either dive during which time over 825 male albino rats were exposed to pressure. The success of these two dives demonstrated the efficacy of long-term animal diving as a model system for investigation of the biochemical and physiological aspects of compressed air saturation diving.