To clarify functional neural pathways originating from the thalamic nucleus ventralis posterolateralis (VPL) in humans, the responses of regional CBF (rCBF) and regional CMRO2 (rCMRO2) to VPL stimulation were investigated by positron emission tomography in five patients who had undergone chronic implantation of electrodes into the VPL for therapeutic purposes. Measurement of rCBF and rCMRO2 under continuous inhalation of C15O2 and 15O2 by steady-state methods revealed significant increases of rCBF and rCMRO2 in the frontal, postcentral, and thalamic regions. The increases in rCBF and rCMRO2 of the postcentral regions were clearly predominant in the stimulated hemisphere insofar as the stimulation produced moderate paresthesia in restricted areas of the body. These results indicate that the VPL relays peripheral somatosensory information, which has previously been demonstrated to be transmitted to the frontal as well as postcentral regions.

The temperature dependences of the peak energies and intensities of the high-energy band (band A) and the low-energy band (band B) of the spin-wave-assisted photoluminescence in MnO have been studied at low temperatures down to 5 K. Side bands due to combinations of the elementary excitations (Mn2+ excitons, spin-wave quanta (magnons), TO phonons and LO phonons) were also observed below 40 K as shoulders appearing on the high-energy side of band A.

A rare pituitary adenoma associated with Rathke's cleft cyst was discovered incidentally in a 44-year-old male admitted after head trauma. Neurological and physiological examination found no abnormalities, except for panhypopituitarism. Computed tomography and magnetic resonance imaging demonstrated a solid mass in the sellar cavity with suprasellar extension, associated with a cystic mass extending into the third ventricle. The tumor was removed subtotally by the transcranial approach. Light microscopy demonstrated that the cyst wall was composed of ciliated columnar cells, cuboidal cells, and goblet cells, and the solid part indicated chromophobe pituitary adenoma. Immunohistochemistry demonstrated that a few adenoma cells were positive for prolactin and the cyst wall cells were positive for cytokeratin and negative for S-100 protein.

Regional cerebral turnover of 11C following intravenous injection of 11C-1-pyruvate was investigated in 12 patients with brain tumors. The positron emission tomography (PET) image taken at 10-15 min after the injection always demonstrated a high concentration of 11C in tumor, and thus visualized precise tumor contours. This phenomenon was not influenced qualitatively by the variation of blood flow in the tumor. Brain edema associated with the tumor was not visualized. We conclude that the localization of brain tumors would be well determined by the PET scan, using 11C-1-pyruvate.

The effects of intravenous (IV) infusion of human recombinant tumor necrosis factor-alpha (rTNF-alpha, Cetus) on normal brain and malignant glioma in rats were examined. Twelve Fischer 344 rats were given either a single injection of 10(6) U rTNF-alpha or injections of 5 x 10(5) U rTNF-alpha for three days. One day post-rTNF-alpha injection(s), rats were injected IV with horseradish peroxidase (HRP) to determine blood-brain barrier (BBB) breakdown and, one hour later, were perfused with an aldehyde fixative and processed for histologic examination. Treatment of normal rats with rTNF-alpha by either dosage or schedule caused no remarkable histopathologic changes in the brain and no alteration in BBB integrity. Human glioma models were produced by intracerebal inoculation of 10(4) syngeneic RT-2 glioma cells into the right parietal lobe of 30 rats. Animals received single IV injections of 10(6) U human rTNF-alpha or its excipient (TNF-E) as above on day 3, 7, or 10 post-tumor inoculation or multiple injections of 5 x 10(5) U rTNF-alpha beginning on day 7, 10, or 12 post-tumor inoculation. With a single IV injection of either rTNF-alpha or its excipient, 3-day models showed a similar pattern of HRP extravasation limited to the extracellular space of the tumor inoculation site. In 7-day models treated with a single IV injection of rTNF-alpha or TNF-E, HRP extravasated throughout the tumor, but did not exceed peritumoral margins. In 10-day models treated with a single injection of TNF-E, HRP was found only in the tumor and immediate peritumoral regions while rTNF-alpha-treated rats showed more extensive areas of BBB breakdown with HRP evident throughout the entire right hemisphere and extending via the corpus callosum into the contralateral hemisphere. Pericapillary halos were also evident around the small blood vessels within the edematous areas of the corpus callosum. Within tumors, hemorrhagic necrosis and adherence of neutrophils to vessels was observed only in animals treated with rTNF-alpha at 10 days post-tumor inoculation. Multiple IV injections of rTNF-alpha in 7 and 10-day models triggered widespread hemorrhagic necrosis, neutrophil adherence and infiltration in the tumor. There was also extravasation and diffusion of HRP from the site of glioma into the contralateral hemisphere. Twelve-day models treated with multiple rTNF-alpha injections, in addition, showed irregular luminal surfaces and gaps between adjacent endothelial cells of tumor vasculature.(ABSTRACT TRUNCATED AT 400 WORDS)