The Effect of Various Cytotoxic Agents on Bone Marrow Progenitor Cells as Measured by Diffusion Chamber Assays

Two diffusion chamber assays, termed the 'Full" chamber technique and the 'Empty' chamber technique, have been used to determine the effect of various doses of cyclophosphamide, vinblastine and busulphan on the population of diffusion chamber progenitor cells (DCPC). The diffusion chamber dose-response curves were compared to the progenitor cell survivals estimated by the spleen colony technique. The in vitro agar colony assay was also performed on the busulphan-treated marrow. The diffusion chamber and spleen colony techniques estimated similar survivals after cyclophosphamide and vinblastine treatment. However, with busulphan, the chamber, spleen colony and agar colony methods estimated different survivals. The indication is that the diffusion chamber techniques assay the same population of cells as the spleen colony technique, and that busulphan alters the capacity of surviving DCPC to generate granulocytes and macrophages.     

Behavioural effects of d-amphetamine in young chicks treated with p-Cl-phenylalanine

d-Amphetamine administered to five day old chicks provoked wing droop, postural changes and twittering.p-Cl-phenylalanine methyl ester (H 69/17) which lowered the content of 5-HT and 5-HIAA in the brain to about 30% of control values in chicks of the same age, induced no marked behavioural changes. Pretreatment with H 69/17 protected against the above mentioned effects of d-amphetamine. Simultaneously d-amphetamine induced marked excitation with aggressive behavioural components.It is concluded a) that the predominant actions of d-amphetamine in newly hatched chicks are mediated via a serotonergic (tryptaminergic) mechanism, which masks the excitatory effects of the drug in this animal species, and b) that there are great similarities, between the behavioural changes seen after d-amphetamine in 5-HT depleted chicks and imipramine in normal chicks.     

Cardiovascular rehabilitation: status, 1990

Cardiovascular rehabilitation is defined as the process of development and maintenance of a desirable level of physical, social, and psychologic functioning after the onset of a cardiovascular illness. Patient education, counseling, nutritional guidance, and exercise training play prominent roles in the process of rehabilitation. Benefits from cardiac rehabilitation include improved exercise capacity and decreased symptoms of angina pectoris, dyspnea, claudication, and fatigue. Recent pooled data regarding exercise training after myocardial infarction demonstrated a 20 to 25% reduction in mortality and major cardiac events. Exercise training may result in an improvement in systemic oxygen transport, a reduction in the myocardial oxygen requirement for a given amount of external work, and a decrease in the extent of myocardial ischemia during physical activity. The efficacy of modification of risk factors in reducing the progression of coronary artery disease and future morbidity and mortality has been established. Herein we review the history, current practice and results, and future challenges of cardiovascular rehabilitation.     

A noninvasive method of estimating mean pulmonary artery pressure in the pneumatic total artificial heart

Accurate hemodynamic monitoring is essential for the clinical management of the recipient of a total artificial heart (TAH). The high incidence of pulmonary congestive disorders in this population complicates this already formidable task. Lack of diagnostic pulmonary artery pressure (PAP) information is recognized as a fundamental source of these problems. Because conventional methods of obtaining hemodynamic information are difficult to implement in TAH recipients, improvement of TAH case management depends on the development of innovative monitoring strategies. Noninvasive monitoring techniques have been developed for three (right atrial pressure, left atrial pressure, and aortic pressure) of the four auxiliary circulatory pressures used to quantify hemodynamic performance. Development of the fourth, for PAP, was the subject of this work. We developed a noninvasive, in vitro method of estimating mean PAP in the Jarvik-7 TAH (Symbion, Inc, Salt Lake City, UT) recipient. This information was obtained by analyzing the relationship between the pneumatic right drive pressure (RDP) and PAP waveforms produced by a Jarvik-7 (70 ml) connected to a Donovan mock circulation and driven by a Utahdrive System IIIe Controller (Symbion, Inc, Salt Lake City, UT). Total artificial heart driver parameters (i.e., heart rate, percent systole, and vacuum) were manipulated to produce a range of ventricular filling volumes (FV), from 40 to 60 ml, for three distinct states of the pulmonary vasculature: hypotensive, normal, and hypertensive. A unique multiple-linear regression equation was derived for each FV from the RDP-PAP relationship exhibited under these conditions. Comparison of computed estimates of PAP with actual measurements showed overall average correlations of greater than 0.92, with a standard error of the estimate of less than 1.9 mm Hg. The mean difference between actual and computed PAP measurements was –0.03 ±2.0 Hg. Estimations were accurate within 8.5% of true PAP values. Additional experimentation revealed that while the RDP-PAP relationships are dependent on FV, they are independent of the manner in which FV was obtained. Estimates proved useful over the clinical operating range of the pneumatic heart driver, as well as over the normal physiologic range of PAP in the human. This method is readily applicable to a computer-based monitoring implementation, although its effectiveness needs to be demonstrated in vivo.     

The effect of altrenogest, an oral progestin, on hematologic and biochemical parameters in mares

Twenty mares were assigned to 1 of 4 groups: no altrenogest; altrenogest at 0.044 mg/kg BW; altrenogest at 0.132 mg/kg BW; or altrenogest at 0.220 mg/kg BW. Treatment was administered daily for 86 days. No signs of illness attributable to feeding altrenogest were observed during the trial. Treatment had no effect (P greater than .05) on the following parameters: WBC, differential WBC, platelet number, creatinine, LDH, CPK, total bilirubin, cholesterol, globulin, BSP, and erythrocyte sedimentation rate. When comparing values over time with pretreatment means or among treatment groups, there were differences (P less than .05) in RBC, PCV, Hb, ALT, PT, PTT, P, Na, TP, BUN, Cl and glucose. However, these changes remained within established normal ranges and also occurred in mares in the control group. There was no treatment by time interaction for any of these parameters. Treatment differences (P less than .05) were observed for K, Ca, alkaline phosphatase and AST during the course of the trial. However, only occasional values of these parameters were outside the established ranges. They were only slightly elevated and tended to be either sporadic or also occurred in control mares. Few of the observed changes could be attributed to the feeding of altrenogest.