Regulation of intracranial pressure in the rat with chronic moderate hypercapnia.

STUDY OBJECTIVES: In this animal study we investigated whether CO2-induced intracranial hypertension was sustained in chronic hypercapnia. DESIGN: We kept five rats in a 10% CO2-air mixture (PaCO2 73.4 +/- 6.2 Torr, mean +/- 1SD) for 22 weeks, and then measured the rats' intracranial pressure while breathing the 10% CO2- air mixture or the room air. RESULTS: The intracranial pressures recorded during chronic hypercapnia in systole and diastole were 7.0 +/- 1.9 and 5.4 +/- 1.6 mm Hg, respectively. When the rats were acutely exposed to the room air (PaCO2, 51.9 +/- 10.2 Torr), the intracranial pressures in systole and diastole were 6.1 +/- 1.4 and 5.0 +/- 0.8 mm Hg, respectively, were not significantly different from those during hypercapnia (P>0.05, paired t-test). CONCLUSIONS: The intracranial pressure in rats with chronic moderate hypercapnia was not significantly different from normocapnic rats, and this change was associated with a blunting of intracranial pressure autoregulation.

Acute eosinophilic pneumonia evaluated with high-resolution computed tomography.

We describe two cases of acute eosinophilic pneumonia (AEP) presenting with high fever and hypoxia of acute onset with bilateral interstitial infiltrates on chest roentgenograms. Diagnosis was confirmed in each case by bronchoalveolar lavage and transbronchial lung biopsy in which the pathologic process was limited to the lung interstitium. High-resolution computed tomography (HRCT) of the thorax at the height of the disease process revealed peripheral ground-glass opacities along the bronchovascular bundles. Symptoms and radiologic abnormalities resolved spontaneously within two weeks. The HRCT-findings may reflect the pathologic process in AEP and the ground-glass opacities likely indicate spontaneous resolution without corticosteroid therapy.

Morphological differentiation of cumulus-oocyte complexes induced by the administration of gonadotropins in mice.

The morphological changes were examined in the present study in mouse cumulus-oocyte complexes and granulosa cells induced by the administration of pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Dissolution of the germinal vesicle (GVBD) occurred in oocytes at 3 hr after hCG administration. Partial expansion of the cumulus cell investment was observed in the cumulus-oocyte complexes, especially those with the oocytes having undergone GVBD. Cumulus expansion due to the deposition of intercellular materials stained with colloidal iron proceeded up to 8 hr after hCG administration. The number of cells in the follicles containing matured oocytes is smaller than that in the follicles containing intact germinal vesicles in the granulosa cell layer, which indicates that the dispersion of cells occurs during meiotic maturation not only in the cumulus-oocyte complexes but also in the granulosa cell layer. Examination of the expansion of mouse cumulus-oocyte complexes by electron microscopy revealed the abundant deposition of intercellular materials and the retraction of the cytoplasmic processes joining the cumulus cells to the oocyte at 3 hr after hCG administration.