Chronic intermittent hypoxia decreases the expression of Na/H exchangers and HCO3-dependent transporters in mouse CNS.

Chronic intermittent hypoxia (CIH) is a component of several disease states, including obstructive sleep apnea, which results in neurocognitive and cardiovascular morbidity. Because chronic hypoxia can induce changes in metabolism and pH homeostasis, we hypothesized that CIH induces changes in the expression of acid-base transporters. Two- to three-day-old mice, exposed to alternating cycles of 2 min of hypoxia (6.0-7.5% O2) and 3 min of normoxia (21% O2) for 8 h/day for 28 days, demonstrated decreases in specific acid-base transport protein expression in most of the central nervous system (CNS). Sodium/hydrogen exchanger isoform 1 (NHE1) and sodium-bicarbonate cotransporter expression were decreased in all regions of the CNS but especially so in the cerebellum. NHE3, which is only expressed in the cerebellum, was also significantly decreased. Anion exchanger 3 protein was decreased in most brain regions, with the decrease being substantial in the hippocampus. These results indicate that CIH induces downregulation of the major acid-extruding transport proteins, NHE1 and sodium-bicarbonate cotransporter, in particular regions of the CNS. This downregulation in acid-extruding capacity may render neurons more prone to acidity and possibly to injury during CIH, especially in the cerebellum and hippocampus. Alternatively, it is possible that O2 consumption in these regions is decreased after CIH, with consequential downregulation in the expression of certain cellular proteins that may be less needed under such circumstances.

Primary non-Hodgkin's lymphoma of the duodenum.

Primary non-Hodgkin's lymphoma of the duodenum is an uncommon primary tumor of the gastrointestinal (GI) tract. Diffuse, large cell lymphoma of B-cell origin is currently recognized as representing the predominant histologic type of primary extranodal lymphoma arising in a gastrointestinal site. Three patients are presented with primary lymphoma arising in the second (two) and fourth (one) portions of the duodenum. Two patients with Stage I-E disease were treated by pancreaticoduodenectomy followed by postoperative radiotherapy, and remain without recurrence at 8 and 6 years. A third patient with Stage II-E disease of the fourth portion of the duodenum was treated with total resection of all bulky disease followed by chemotherapy without radiotherapy. However, this patient died after 46 months. The literature is reviewed, with emphasis on the use of surgical resection in the treatment of non-Hodgkin's lymphoma of the duodenum.

Tension pneumocephalus five years after intracranial resection of pituitary adenoma--a case report.

A case of spontaneous pneumocephalus with progression to tension pneumocephalus is presented. It is unique because it occurred spontaneously via a sellar defect 5 years after resection and irradiation of a pituitary adenoma, without tumor recurrence. Computed tomography clarified the extent of the pneumocephalus and its progression to tension pneumocephalus.