Optimal value of filling pressure in the right side of the heart in acute right ventricular infarction

Haemodynamic monitoring was performed within the first 48 hours after the onset of symptoms in basal conditions, during volume loading, and during infusion of glyceryl trinitrate in 41 patients who fulfilled the diagnostic electrocardiographic and haemodynamic criteria of right ventricular infarction. In most patients an increase of mean right atrial pressure up to 10-14 mm Hg was followed by an increase in right ventricular stroke work index. But raising the mean right atrial pressure above 14 mm Hg was almost always accompanied by a reduction in right ventricular stroke work index. When the mean right atrial pressure was reduced by intravenous glyceryl trinitrate to less than 14 mm Hg the right ventricular stroke index increased. The same response was seen with cardiac and stroke index. The mean (SD) values of optimal right atrial and pulmonary capillary pressures were 11.7 (2.1) and 16.5 (2.7) mm Hg respectively. Thus cardiac and stroke index increased and the right ventricle reached its maximum stroke work index when the filling pressure was 10-14 mm Hg. These values may be regarded as the optimal level of right ventricular filling pressure in patients with right ventricular infarction.

Acute haemodynamic effects of nifedipine in patients with ventricular septal defect

The haemodynamic effects of nifedipine were studied in 14 patients (aged 8-14 years, seven male and seven female) with ventricular septal defect with and without pulmonary hypertension. All underwent left and right heart catheterisation. In each patient the pressures and heart rate were measured and blood samples were taken for oximetry before and after sublingual administration of 10 mg nifedipine. In eight patients with ventricular septal defect without pulmonary hypertension (mean pulmonary artery pressure less than 20 mm Hg) nifedipine significantly reduced the mean aortic pressure and systemic vascular resistance, and significantly increased heart rate. The other haemodynamic indices did not change significantly. In six patients with ventricular septal defect complicated by pulmonary hypertension (mean pulmonary artery pressure greater than 20 mm Hg) nifedipine significantly increased systemic output, stroke volume, and heart rate, and significantly reduced systemic vascular resistance and the pulmonary to systemic flow ratio. The other haemodynamic indices did not change significantly. Nifedipine had a beneficial effect in patients with ventricular septal defect complicated by pulmonary hypertension. It reduced the left to right shunt and increased the stroke volume. This effect was not seen in patients with ventricular septal defect uncomplicated by pulmonary hypertension.

Protection against hemorrhagic pneumonia of mink by Pseudomonas aeruginosa multicomponent vaccine

An attempt to prevent epidemics of hemorrhagic pneumonia in mink due to Pseudomonas aeruginosa was made in the course of epidemics with injection of the multicomponent vaccine consisting of common protective antigen (OEP) of P. aeruginosa mixed with toxoids of protease and elastase of the bacillus. Enzootics of hemorrhagic pneumonia, due to P. aeruginosa serotype 8, broke out from August to October 1977 in a total of 13 sheds of 3 farms (A, B and C) which were located in the northeast area of Hokkaido. These farms were raising 7,452, 2,553 and 10,639 mink respectively. The mortality rate of the mink on farms A, B and C were 11.8%, 13.0% and 1.0% respectively. The vaccination was performed on the 3 farms 5, 8 and 21 days after the onset of the disease. Inoculation of each mink with 200 micrograms or 100 micrograms of each of the three components of the multicomponent vaccine was effective in most of the male and female groups of mink. The period required for revealing the effect of the vaccination was very short, in some cases only a few days. Administration of the vaccine 21 days after the onset of the enzootic was also effective.

Effectiveness of immunization with single and multi-component vaccines prepared from a common antigen (OEP), protease and elastase toxoids of Pseudomonas aeruginosa on protection against hemorrhagic pneumonia in mink due to P. aeruginosa

Toxoids of protease and elastase of Pseudomonas aeruginosa were successfully prepared by treatment with 8% formalin plus 0.2 m lysine and by 4% formalin respectively. The two toxoids proved sufficiently potent to elicit high antibody titers as estimated by both the enzyme-neutralizing and passive hemagglutination tests. The effectiveness of immunizing minks with a single component-vaccine consisting of the common antigen (OEP) of P. aeruginosa or the protease toxoid (PT) or the elastase toxoid (ET) and with the two (PT and ET) or the three (OEP, PT and ET) component-mixed vaccines, on hemorrhagic pneumonia in minks due to the bacteria was investigated. Female Sapphire minks, 3.5 months old, were used in two experiments performed in 1975 and 1976. Minks were immunized three times in one month with a total of 1 mg of each of the three antigens in the case of a single component vaccine and with a total of 2 or 3 mg (equal amounts of each component) in the case of the two or three component vaccines. Two or three weeks after the last immunization, challenge exposure with strain No. 5 was carried out by intranasally inoculating an inoculum containing serial dilutions of 10(3) -10(10) of live bacteria. Summarizing the results of the two experiments, in the case of controls, nonimmunized minks and minks immunized with potassium aluminum sulfate (potash alum) alone, the LD50 values were approximately 10(3) -10(4) with no significant difference between the two. In the case of OEP-vaccinated minks, the LD50 value was about 10(6) and thus clearly differed from those of the controls. In minks immunized with the three-component-vaccine, however, the LD50 value was about 10(8) -10(9), which indicated that the three-component-mixed vaccine was remarkably more effective than the single OEP vaccine component. In minks immunized with either PT or ET or both, the LD50 values were about 10(8) -10(9). The effectiveness of the vaccine made with ET or PT alone is discussed in the text. The pathological findings of the minks which died or survived are described.