Acute hemodynamic interventions shift the diastolic pressure-volume curve in man

Frame-by-frame analysis of angiograms in 16 patients revealed that hemodynamic interventions are capable of producing substantial shifts in the diastolic pressure-volume curve. Angiotensin raises blood pressure and shifts the entire pressure-volume curve up, and nitroprusside lowers blood pressure and shifts the curve down. Indirect measurements of pleural pressure in seven patients (via esophageal pressure) showed that pleural pressure changes were too small to account for these shifts. Analyzing our results in terms of a theoretical pressure-volume equation previously validated in dog studies did not show the observed shifts to be the product of acute changes in the elasticity of the myocardium itself. This same analysis suggested that indirect changes in the external mechanical constraints acting on the left ventricle such as the right ventricular pressure, the pericardium, and perhaps viscoelastic effects related to changes in filling rate account for the pressure-volume curve shifts with intervention. The fact that one cannot in general relate a specific volume to a given pressure in the face of hemodynamic interventions calls into question the use of end-diastolic pressure interchangeably with end-diastolic fiber length when interpreting systolic events in terms of the Frank-Starling mechanism.     

The radiology of transsphenoidal hypophysectomy: a review of 100 cases

This report describing the radiology of transsphenoidal hypophysectomy based on a review of 100 consecutive surgical procedures. Preoperative laminographic evaluation of the sphenoid sinus is an important aid in planning the most direct surgical approach to the pituitary. It is also useful in defining the many anatomic structures that may be injured inadvertently at the time of surgery. Intraoperative radiography or fluoroscopy is helpful in identifying the sella floor and as an aid in preventing loss of orientation within a capacious sinus. Various changes occur within the sphenoid sinus following surgery, some transient and others persistent. The surgical defect is usually difficult to identify on routine roentgenograms but is clearly visible on lateral laminography. A persistent soft tissue mass within the sinus is usually a manifestation of fascia and fat placed as a seal within the sinus.     

Rewarming from immersion hypothermia: a comparison of three techniques

Analysis of measurements from the tali of 21 individual fossil primates from Africa shows that the specimens fall into five clearly defined groups. Accordingly, these specimens have been included as groups along with extant species in a subsequent canonical analysis thus allowing the fossils to play their part in the determination of the canonical separations. The results of this procedure show that the five fossil groups lie in a part of the canonical space not occupied by any extant African primate. Their positions are between the envelope of Asiatic apes (Hylobates and Pongo) and the envelope of African forms near the edge which contains Pan and Papio. One fossil group is so similar to Hylobates that its talus may have functioned in locomotion in a parallel manner. Others lie near to Pongo in directions proceeding towards Pan and Papio and it is possible that this similarity may indicate remnants of morphological adaptation for climbing in these fossils. At the same time, however, individual specimens are closer to one or another of the extant groups and this considerable spread suggests that the locomotor adaptations as evidenced by talar morphology, of the primate fauna in Africa, may have been very different from those of the present day. This would not the inconsistent with the different habitats, floras and non-primate faunas that may have characterized the East African scene at these earlier times. Particular fossils from Olduvai and Kromdraai that are supposed to be australopithecine and therefore bipeds, are confirmed (Oxnard, '72; Lisowski et al., '74) as being totally different from man in their talar morphology and essentially rather similar to the majority of the other fossil tali examined.     

Circulatory effects of diazepam in heart disease

Diazepam was administered to ten patients with heart disease during diagnostic cardiac catheterization, in order to determine whether or not this drug's circulatory actions could alter results obtained during the procedure. Diazepam produced no change in baroreceptor sensitivity; however, there was a significant rise in heart rate and a significant fall in aortic systolic and left ventricular end-diastolic pressures. Cardiac index was unchanged, whereas stroke volume fell significantly. Systemic vascular resistance and peak left ventricular dp/dt did not change throughout the study. Clinical response in terms of sedation was judged to be satisfactory in eight patients, and no adverse effect on respiration was noted. Diazepam has little effect on basal circulatory and respiratory parameters when changes in these parameters are averaged for our ten patients. However, substantial changes in hemodynamic parameters did occur in several individuals, and such alteration in circulatory function must be considered when this agent is used routinely in patients having diagnostic cardiac catheterization.     

Critical issues in mental health service delivery: what are the priorities?

The director, one other professional, and one para-professional in 515 community mental health centers and 193 state hospitals throughout the United States were asked to rate 57 critical issues in mental health services as to their importance now and five years from now. Issues judged most important now are services for children and for adolescents; five years from now children's services still top the list. Answers to two other questions revealed that respondents placed research on prevention at the top of a list of needed research areas, and that the most useful NIMH service to agencies was person-to-person assistance such as consultation and workshops.     

Fecal bile acids and neutral sterols in patients with familial polyposis

Fecal neutral steroids and bile acids were measured in patients with familial polyposis, family controls who are immediate relatives of patients, and controls other than relatives. All subjects were consuming a mixed Western diet at the time of collection of stool specimens. Although the total fecal neutral sterol concentrations were not different between the groups, the patients with familial polyposis excreted a high amount of cholesterol and low levels of coprostanol and coprostanone compared with other groups. Patients with familial polyposis excreted levels of total bile acids in their feces comparable to those excreted by controls; lithocholic acid excretion was decreased in patients with familial polyposis. These findings suggest that analysis of stools for cholesterol and its metabolites be useful in screening the siblings of polyposis families for latent disease.     

Prevention of neonatal respiratory distress syndrome through the administration of prednisolone in the fetal period

The clinical effectiveness of antenatal prednisolone medication (prednisolone hemisuccinate) for the prophylaxis of idiopathic respiratory distress syndrome (IRDS) was studied in 114 premature infants with a gestational age between 28 and 36 weeks. There was a statistically significant difference (chi2 - test, p less than 0,01) between the frequency of IRDS in this group and in another one consisting of 137 premature babies with a nearly identical distribution of gestational age, whose mothers did not get prednisolone before delivery. It could be shown that the time interval between medical induction and delivery should not exceed 2 weeks, since the effect decreases with time. At present prednisolone medication during the fetal period may serve as useful prophylactic measure for IRDS in cases of premature birth. As there are a lot of contraindication against prednisolone and as we do know very much about side effects, it seems necessary to seek for other, less dangerous inductors.     

Propranolol therapy in patients undergoing myocardial revascularization

The records of 185 consecutive patients having myocardial revascularization were reviewed with regard to preoperative administration of propranolol and intraoperative or postoperative complications. Tachycardia and hypertension before cardiopulmonary bypass were slightly more common in patients never taking propranolol or those who had discontinued it for more than 48 hours before operation. There was no statistically significant difference in the incidence of postbypass hypotension among patients who took propranolol within 24 hours of operation, those who discontinued it more than 24 hours before operation, and those who never took the drug. Operative mortality was not significantly different among patients who received propranolol within 48 hours of operation (3%), those who never took it and those who discontinued it more than 48 hours before operation (4%). Early in the series, five patients had an acute myocardial infarction within 48 hours after routine preoperative withdrawal of propranolol. Because complete withdrawal of propranolol in patients with unstable angina pectoris may lead to acute myocardial infarction, we recommend gradual withdrawal of the drug during 48 hours before operation. If this is not possible because anginal pain recurs or intensifies, then reduced doses may be given safely up to 10 hours before revascularization, provided that the patient is a satisfactory candidate for bypass and that adequate myocardial revascularization can be accomplished.