Persistent supersensitivity of sigma receptors develops during repeated methamphetamine treatment.

Functional changes in sigma receptors were examined after behavioral sensitization induced by repeated methamphetamine treatment. Rats received either saline or 4 mg/kg methamphetamine for 14 days. (+)3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3-PPP), a sigma receptor agonist, was given as challenge after various periods of abstinence. (+)-3-PPP at doses greater than 6 mg/kg stimulated several forms of behavior in naive rats. (+)-3-PPP at 12 and 24 mg/kg produced more frequent rearing and more intense stereotyped sniffing and repetitive head movements in rats previously sensitized with methamphetamine than in saline-pretreated rats. The augmented response to (+)-3-PPP in methamphetamine-treated rats was maintained for at least one month. The augmented response to (+)-3-PPP was reversed by the combined administration of 100 mg/kg (+/-)-sulpiride, a D2 dopamine receptor antagonist, and 30 mg/kg BMY 14802, a sigma receptor antagonist. These results suggest that repeated methamphetamine treatment induces persistent supersensitivity in sigma receptors and that it may subsequently activate the dopamine system.     

Morphological study of renal changes with age: the possibility of kidney donations by the elderly

Samples from seventy autopsy cases ranging from 27 to 79 years of age who had shown no evidence of renal or malignant diseases were examined histologically to clarify renal changes with age. We evaluated scores for renal histological change and referred the scores to clinical laboratory data; blood pressure, complete blood counts (RBC count, hematocrit, hemoglobin), serum chemistry values (creatinine, urea nitrogen, total cholesterol, total protein, sodium, potassium, chloride) and urinalysis (protein, sediment). We found the score to be related to serum creatinine level, blood urea nitrogen level and the degree of hematuria but not related to the other factors. The progression of arteriosclerosis, tubulo-interstitial change and global sclerosis were found to be severe with ageing. Also renal weight decreased with increasing age. However there were great differences among individuals in the extent of changes. We could not assume histological changes were generally severe in those of more than 55-65 years of age. It was impossible to clarify renal states only with clinical findings. Some kidneys had severe histological changes though less than 2.0 mg/dl of serum creatinine level. It suggests that living relatives and cadavers over 60 years old can be donors for renal transplantation when there are no significant findings of abnormality in preoperative evaluations of their physical state. If insufficient examinations are done, we cannot determine which of them will be good donors. Therefore preoperative biopsy is the best way to evaluate donor suitability. To evaluate only clinical data, it is necessary that serum creatinine level be less than 1.2 mg/dl, blood urea nitrogen level be less than 23 mg/dl and there be no hematuria.     

Assessment of skull base involvement of nasopharyngeal carcinoma by bone SPECT using three detectors system]

SPECT of the skull was performed on twelve patients with histologically proven nasopharyngeal carcinoma using newly developed three detectors SPECT system (Toshiba GCA 9300A) mounted with fan-beam collimators, for the purpose of early detection of skull base involvement of the disease. This SPECT system has extremely improved resolution with FWHM of 8 mm in the center, and it provides clear tomographic images of the skull which has anatomically complex structure. SPECT image was taken 3 hours after injection of 740 MBq (20 mCi) of 99mTc-MDP following whole body skeletal survey. In twelve patients with confirmed nasopharyngeal carcinoma, 8 patients showed positive findings on SPECT. Three of SPECT positive patients also showed destructive findings on CT. Other five positive patients did not show destructive findings on CT at their initial examinations, but in three of them CT findings turned to positive later. SPECT was superior to CT in early detection of skull base involvement. We believe that SPECT of the skull is a diagnostic tool for early detection of skull base involvement of nasopharyngeal carcinoma.     

Capsaicin-like effect of (6)-shogaol on substance P-containing primary afferents of rats: a possible mechanism of its analgesic action.

The effects of (6)-shogaol, a pungent component of dried ginger with a capsaicin-like chemical structure, on the release of immunoreactive substance P from the spinal dorsal horn were examined by in vitro superfusion of the dorsal-half slices of the spinal cord of the rat. (6)-Shogaol (30 microM to 1 mM) increased dose-dependently the release of immunoreactive substance P. The maximum effect of (6)-shogaol was observed at a concentration of 100 microM and less than a half of the effect of 10 microM capsaicin. The effect of (6)-shogaol (100 microM) was attenuated in slices from rats with dorsal rhizotomy and abolished by elimination of calcium ions from the perfusion medium. Pretreatment with (6)-shogaol in vitro inhibited the capsaicin-evoked release of immunoreactive substance P. On the other hand, systemic administration of (6)-shogaol (160 mg/kg) produced antinociception in rats, with a peak effect between 15 and 30 min and a smaller dose of 80 mg/kg was without effect. Treatment of rats with (6)-shogaol, at a dose of 160 mg/kg but not at 80 mg/kg, for 20 min significantly decreased release of immunoreactive substance P, evoked by capsaicin (10 microM), from the slices of cord. These data suggest that (6)-shogaol shares the sites of action with capsaicin, on the terminals of substance P-containing primary afferents, to release of the neuropeptide and inhibit the release of substance P, by subsequent stimulation of the primary afferents. The latter action of (6)-shogaol might be relevant to its analgesic effect.     

Evidence that neurofibrillary tangles undergo glial modification

Summary Ghost tangles, neurofibrillary tangles (NFTs) emerging into extracellular space, appear to be subjected to some microglial association in addition to an invasion of astrocytic processes. Our findings lead us to speculate that the NFTs undergo structural and immunocytochemical modification. Electron microscopic observation of the NFTs in the vascular region indicated either the discharge of NFTs into the vessel or formation of NFTs in the astrocytic end-foot.     

A case of Nasu-Hakola's disease with T2-weighted MRI finding of reduced signal intensity in the thalamus and putamen]

A 30-year-old female received a head injury at the age of 22 years. Subsequently neurological and psychiatric symptoms, such as personality change, urinary incontinence, dementia and gait disturbance developed. On admission, her cognitive function was severely impaired. Brain CT disclosed cerebral atrophy, dilatation of the lateral ventricle and calcification of the basal ganglia. Pathologically membranous structures were recognized in bone marrow. On the basis of these clinical findings, a diagnosis of Nasu-Hakola's disease was made. In this case, a T2-weighted MRI finding of reduced signal intensity in the thalamus and putamen was characteristic. This finding may be related to intracranial calcification.     

Computerized tomography observation of a calcifying cystic odontogenic tumor with an odontoma: case report.

The calcifying cystic odontogenic tumor is a rare benign odontogenic lesion. This report documents a case of this lesion associated with odontoma arising from the anterior maxilla in a 14-year-old boy. The diagnosis was confirmed based on computerized tomography findings, which clearly depicted the internal structures obscured in conventional images.     

Delayed onset massive oedema and deterioration in traumatic brain injury.

A 52-year-old man fell from standing and a computed tomography (CT) scan revealed traumatic intracerebral haematoma and subarachnoid haemorrhage in the temporal cortex. He was treated without surgery and discharged. On day 30 after the accident, he had no neurological deficit. On day 37 he complained of headache and urinary incontinence, and on day 39 he was hospitalized due to progressive neurological deterioration (reduced conciousness, dilated pupils, and left hemiplegia). A CT scan revealed a diffuse low-density in the right cerebral hemisphere with marked midline shift. Emergency decompressive craniectomy and right temporal lobectomy were performed. Angiography after surgery revealed moderate vasospasm in the right middle and anterior cerebral arteries. The patient remained severely disabled. Delayed onset neurological deterioration can be caused by brain oedema and vasospasm after traumatic brain injury, despite an intervening period of improvement.