Effect of age on proliferation-regulating factors in human adult neurogenic regions.

Neurogenesis, the birth of new neurons, continues throughout adulthood in the human subventricular zone (SVZ) and hippocampus. It is not known how levels of putative proliferation-regulating factors change with age in human adult neurogenic areas. The current project employed ELISAs to investigate changes in levels of putative proliferation-regulating factors in the healthy human SVZ and dentate gyrus throughout the adult lifespan (18-104 years).

Refractory hypoxemia in right ventricular infarction: a case report.

Right ventricular infarction has many clinical features. Although hypoxemia is a common presenting symptom with multiple causes in the setting of myocardial infarction, the authors present a case resulting from an acute right-to-left shunt secondary to a previously dormant patent foramen ovale. A 74-year-old male presented to the hospital after feeling unwell for the previous 2 days.

Hemodynamic mechanisms in anaphylaxis.

Intravenous administration of ascaris suum antigen (1 mg) as well as histamine (5 mg) was associated with rapid and marked reductions in cardiac output (QT) and systemic arterial pressure (Pa) in anesthetized mechanically ventilated dogs. When venous return was maintained constant by an external pump reservoir system, both antigen and histamine caused rapid reductions in the reservoir blood volume consistent with peripheral pooling. In addition, interruption of the splanchnic arterial inflow by occlusion of the descending thoracic aorta restored the cardiac output to control during histamine shock, whereas QT during antigen shock was unaffected by aortic occlusion, even though the circulatory failure was of similar magnitude.

Effects of positive end expiratory pressure on shunt flow in atelectasis.

We studied the effects of positive end expiratory pressure (PEEP) on vascular pressure flow relationships in atelectatic lobes in the closed-chest pigs and compared our results to measurements we previously obtained in sublobar atelectasis. Regional hemodynamic responses to lung inflation were significantly different between lobes and sublobar regions. PEEP caused marked increase in the fraction of cardiac output perfusing the atelectatic lobe from 16.

Mechanical factors and the regulation of perfusion through atelectatic lung in pigs.

The role of mechanical interdependence in the perfusion of atelectatic lung was studied in two ways: a) regional hemodynamics were compared before (control) and after the development of lobar and sublobar atelectasis, and b) the effect of thoracotomy on regional hemodynamics was assessed. With lobar atelectasis mean lobar blood flow and vascular conductance decreased to 60% of control. Sublobar atelectasis caused mean sublobar blood flow and vascular conductance to decrease to 6% of control.