Effect of antihypertensive agents on lipid metabolism

Diuretics and adrenergic blocking agents have been used extensively in the treatment of hypertension. Recent studies have indicated that the thiazides and chlorthalidone have an adverse effect on lipid metabolism, by increasing plasma triglycerides, total cholesterol, and low density lipoprotein cholesterol in mildly hypertensive patients. These same agents produced little change in high density lipoprotein cholesterol. On the other hand, the loop diuretic furosemide adversely affected the cholesterol ratio by lowering high density lipoproteins (HDL) instead of increasing very low density lipoproteins (VLDL) or low density lipoproteins (LDL). The centrally acting drug methyldopa has also been reported to lower HDL, while another centrally acting drug, reserpine, appears to be lipid-neutral. Practically all the beta blocking agents increase triglycerides or decrease HDL, thus yielding an adverse cholesterol ratio. The alpha 1-adrenergic blocking agent prazosin has been shown in several studies to have no adverse effect on the lipid profile.

Role of the rat in the transmission of porcine parvovirus

Rats experimentally inoculated with porcine parvovirus (PPV) shed virus in excreta from 3 to 21 days. Rats inoculated subcutaneously with PPV responded serologically with hemagglutination-inhibition titers (512-1,024). The PPV antigen was readily detected in lung and spleen 2 and 3 days after rats were inoculated and in liver and intestine, 4 days. The rats remained clinically healthy. Rats given PPV orally or in drinking water either with PPV-infected cell culture fluid or swine fetal homogenate failed to respond serologically to PPV, the exception being 2 of 4 rats exposed to swine fetal homogenate over a 5-day span. Pigs exposed to PPV-contaminated rat excreta, either by direct oral dosing or by contaminating the feed, failed to seroconvert. Pigs given (IM) PPV which had been isolated on cell culture from rat excreta did seroconvert. Results of these experiments indicated that rats became infected with PPV, but did so after systemic challenge exposure or prolonged oral exposure to highly infective swine fetal homogenate. Insufficient virus was shed by rats to cause susceptible pigs to seroconvert upon oral feeding--thus indicating that a minimal dose is necessary to ensure oral challenge. In a preliminary experiment, seronegative pigs given different doses of PPV orally showed a gradient level of serologic response and different rates of shedding.

Randomized prospective evaluation of cimetidine and antacid control of gastric pH in the critically ill

One hundred forty-four critically ill patients admitted to an intensive care setting were randomly assigned to cimetidine or antacid treatament groups. Gastric pH was monitored hourly. One hundred twenty-three (85%) patients demonstrated a fall in pH to less than 4 and were considered to require prophylaxis. Prophylaxis was considered adequate if the measured pH could then be maintained at greater than or equal to 4. Fifty-eight patients received antacids alone, the average requirement being 41 cc/hour. Sixty-five patients received cimetidine. Seventeen (26%) of the cimetidine prophylaxis patients failed to raise their pH and were than placed on hourly administration of antacid with successful elevations of pH to greater than or equal to 4 in all cases on an average supplementary dose of 53 cc/hour. Risk factors, including sepsis, hypotension, head injury, respiratory failure, degree of trauma, and age, were not statistically different in the two treated groups. Using these same criteria, responders to cimetidine could not be differentiated from nonresponders. All patients were protected from significant stress bleeding while on this study. Significant complications of either treatment were minimal. Antacids offered consistent protection against gastric acidity and were 100% effective. A routine schedule of 300 mg every six hours of cimetidine was effective in only 47% of patients, and the maximum dose of cimetidine was effective in only 74% of patients. Hourly measurement of intragastric pH is required for monitoring the response to prophylaxis of stress bleeding in severely ill patients.

The use of progesterone and oestrogen concentrations in the diagnosis of pregnancy, and in the study of seasonal infertility in sows

Plasma concentrations of progesterone and oestrogen in sows 18 days after mating were examined, firstly, as a method of pregnancy diagnosis, and secondly, for indication of any abnormal endocrine patterns that may have been involved in the aetiology of seasonal infertility in sows. Progesterone levels were the most relevant indicator of ovarian function. For the diagnosis of pregnancy, progesterone levels were accurate (97 %), but for the diagnosis of non-pregnancy, especially where a high degree of early embryonic death and/or cystic follicles was suspected, as in this trial, progesteronc levels were not as accurate (60%). Oestrogen levels were of use only in confirming the type of infertility suffered by non-pregnant sows. This study shows that seasonal infertility in mated sows is a complex of several forms of infertility, each manifest in a common physical symptom of delayed return to oestrus after a normal mating to a fertile boar. The forms of infertility involved appear to be early embryonic death, luteinized ovarian cysts, small ovarian cysts and silent oestrus.

The unmotivated patient syndrome: survey of therapeutic interventions

The authors describe five groups of patients who have been found to respond poorly to psychiatric treatment--people from lower socioeconomic groups, juvenile delinquents, drug-addicted individuals, alcoholics and military psychiatric patients. Although these groups of patients represent different etiologies and symptom-specific pathologies, many of their members have in common a lack of motivation for change. The authors discuss the reasons for this lack of motivation, suggesting that focusing on this factor would promote a better understanding of the unmotivated patient syndrome and lead to the development of more effective psychotherapeutic efforts.