"My hand" sign associated with tactile extinction in two patients with callosal lesion

Two patients with "my hand" sign in association with tactile extinction from callosal lesion, one due to left anterior cerebral artery occlusion, the other due to right anterior cerebral artery aneurysm rupture, were reported. The examination of "my hand" sign was performed with the methods proposed by Brion et al. Our patients correctly responded when they grasped their own or the examiner's thumb with their left hand. But they replied "my finger"when they grasped not only their own but also the examiner's thumb with their right hand. Left tactile extinction was observed after a routine extinction test in one patient, and it was observed in the other after the following method: both patient's index fingers were disposed in his midline position. In these methods of extinction test, they made errors in saying "right" when both fingers were touched simultaneously. However, they said "both" when their right index finger alone was touched (synchiria) during an extinction test using the following method: both index fingers of patients were approached by examiner to touch each other or for one of them to touch the examiner's finger. When they were asked whose finger they touched in this method (whose finger test), they made the same errors as seen in "my hand" sign test. These test results suggest that there is a common underlying mechanism in the "my hand" sign and extinction, because the sense of double stimulations felt when only one stimulation is given (synchiria), is a possible explanation for the "my hand" sign and the pathogenesis of synchiria appears to be related to extinction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age-related decrease of 11C-N-methylspiperone in vivo binding to human striatum detected by PET

The effect of aging on 11C-N-methylspiperone binding to living human striatum was demonstrated using positron emission tomography. The 11 normal volunteers (22 to 72 years old) participated in this study. The uptake of 11C-N-methylspiperone in the brain following intravenous injection was highest in the striatum in individual subject. And the uptake in the striatum only gradually increased until the end of the study. The uptake of 11C-N-methylspiperone in cerebellum peaked within 10 minutes following injection and then rapidly dropped. The association rate constant "k3" was calculated from the slope of the radioactivity-ratio of striatum to cerebellum versus the equivalent time. The equivalent time was calculated from the radioactivity of cerebellum as an input function. The exponential decrease of the k3 value with aging was observed. The k3 value of the youngest subject (22 years old, male) was 0.035/min, while that of the oldest one (72 years old, male) was found to be 0.020/min. These data suggested that the dopaminergic activity through D2 dopamine receptors reduces with aging in human striatum.     

Transient induction of single GST-P positive hepatocytes by DEN

The single cells positive for placental glutathione S-transferase(GST-P), detectable in livers of rats soon after treatment withhepatocarcinogens, are possible ‘initiated cells’,the hypothesis tested in the present series of experiments.No low dose threshold was observed in male Sprague-Dawley ratsat different single doses of diethylnitrosamine (DEM) althougha plateau was reached between 160 and 200 mg/kg body weight.At the latter single dose 12 400 positive cells/cm³ were observedimmunohistochemically in rat livers after one week, the numbersthen decreasing to week 8 and thereafter rising again. In thenumbers then decreasing to week 8 and thereafter rising again.In the early stages single cells predominated but with timea gradual increase in mini-foci and larger lesions became evident.Application of selection pressure (feeding of diet containing0.02% 2-AAF plus partial hepatectomy) to rats 2–24 weeksafter single DEN-treatment resulted in the formation of largefoci positive for GST-P, especially in the early stages, thegrowth response being less pronounced with time. The numberof foci, on the other hand. was correlated with the number offoci, on the other hand, was correlated with the number ofsingle cells/mini-foci detected inhepatectomy tissue of thesame individuals. These results suggest that the early GST-Ppositive populations could be the precursor for preneoplasticfoci and nodules.     

Expression of Jun activation domain-binding protein 1 and p27 (Kip1) in thyroid medullary carcinoma

AIMS: p27 is a prominent regulator of cell proliferation by universally inhibiting the cell cycle, while Jun activation domain-binding protein 1 (Jab1), a multifunctional cell signaling protein, contributes to carcinoma progression by degrading p27. In this study, we investigated the expression of these proteins in medullary thyroid carcinoma. METHODS: We immunohistochemically examined Jab1 and p27 expression in 64 medullary thyroid carcinomas. RESULTS: Of the 64 cases examined, decreased p27 expression was observed in 38 cases (59.4%). The p27 expression level was inversely linked to tumour size as well as plasma calcitonin level. Jab1 expression level was generally high, and 46 cases (71.9%) were classified as overexpressing Jab1. The incidence was higher than those in papillary and follicular carcinomas, which were previously reported. Jab1 expression level was inversely linked to that of p27, and all five cases with only cytoplasmic but not nuclear staining of p27 overexpressed Jab1. CONCLUSIONS: These findings suggest that (1) decrease in p27 expression may contribute to local tumour growth; (2) Jab1 expression is related to the progression of medullary carcinoma by decreasing the amount of p27 in the cell and accelerating its degradation; and (3) Jab1 may play a more vital role in the pathogenesis of medullary carcinoma than papillary and follicular carcinomas.     

Uncoupling of cerebral blood flow and glucose utilization in the regenerating facial nucleus after axotomy

Axotomy is known to activate various metabolic processes including protein synthesis and glucose utilization in the motor nucleus. Although it is generally assumed that the local cerebral blood flow (CBF) fluctuates in response to the axonal reaction, there has been no direct evidence for changes in CBF in the motor nucleus following axotomy. In this study, the CBF in the facial nuclei was measured after axotomy of the facial nerve employing the [14C]iodoantipyrine method to evaluate the relation between the CBF and axonal reaction. Following unilateral facial nerve axotomy in neonates, which induced neuronal degeneration in the facial nucleus, the CBF and glucose uptake was significantly decreased on the operated nucleus, suggesting that CBF and glucose metabolism are coupled in the degenerating nucleus. In contrast, after axotomy in adults, which induced regeneration of neurons and glial reactions, glucose uptake was increased on the operated nucleus, while the CBF did not differ significantly between the operated and unoperated nucleus. These findings imply that glucose metabolism and CBF are uncoupled in the regenerating nucleus, suggesting that the relation between CBF and metabolism in the regenerating nucleus following axotomy may clearly contradict the classical concept of a tight coupling between CBF and metabolism.     

7 Fälle von Plasmozytome

In diesen Jahhren haben wir einez unehmende Zahl des Beispielsfalls von Pasmozytome auch bei uns in Japan. Und obwohl es noch eine Frage bleibt, ob wir diese Tatsache als wirkliche Zunahme der Krankheit annehmen können, wollen wir hier ihre 7 Fälle berichten, die wir neulich beobachten. Wir bemerken an ihrer klinischen Diagnose zuerst den Schmerz und Anämie, die der Destruktion des Knochensubstanzes entspringen, geringe Leukozytose und die Beschleunigung der Blutsenkungsgeschwindigkeit, es sind aber vor allem der Elektrophorese-Diagram des Serums und die Erscheinung der Paraprotein im Harn, die mit der Krankheit am engsten zusammenhängen. Trotzdem müssen wir darauf achten, daß diese zwei bezeichenden Befunde seltenerweise ausbleiben können (Tbb. 1, 2).     

Thr123 of rat G-substrate contributes to its action as a protein phosphatase inhibitor

Rat G-substrate cDNA was isolated from a cerebellar library and characterized. The deduced amino acid sequence of rat G-substrate contained two putative phosphorylation sites for PKG at Thr72 and Thr123; the amino acid sequences (KPRRKDT(p)PA) around these sites are conserved in human, mouse and rabbit. G-substrate phosphorylated by PKG inhibited the catalytic subunits of both protein phosphatase-1 (IC(50) 14.1 nM) and -2A (IC(50) 5.9 nM). Mutation of Thr123 (site 2) to Ala significantly reduced the inhibition of both PP-1 and PP-2A, while mutation of Thr72 (site 1) to Ala had little effect on inhibitory activity. In situ hybridization analysis revealed that G-substrate mRNA was localized exclusively in cerebellar Purkinje cells. Immunoperoxidase staining showed that in Purkinje cells, G-substrate was present in somata, dendrites and axons. In rat cerebellar slices, activation of PKG with a nitric oxide (NO) donor, NOR3, or 8-Br-cGMP, increased phosphorylation of G-substrate, as demonstrated with a phosphorylation-specific antibody. These results characterize further the inhibition of PP-1 and PP-2A by phospho-G-substrate, and demonstrate its physiological phosphorylation in rat Purkinje cells.     

Low grade malignant peripheral nerve sheath tumour: varied cytological and histological patterns

BACKGROUND: A small number of malignant peripheral nerve sheath tumours (MPNSTs) are low grade, and the nature of these low grade tumours has never been systematically assessed. AIMS: To describe the clinicopathological, immunohistochemical, and ultrastructural features of low grade MPNST and to discuss the main differential diagnoses. METHODS: Four cases of low grade MPNST were studied, including one coexistent with neurofibromatosis type 1. The tumours were analysed with respect to nuclear atypia, cellularity, nuclear enlargement, hyperchromasia, mitotic rate, and necrosis. Immunohistochemistry was performed by standard techniques, and an ultrastructural study was performed on one tumour. RESULTS: The ages of the patients ranged from 32 to 72 years (mean, 58). Two were male and two were female. Three tumours occurred in the deep tissue, including one in the retroperitoneum, and one was located in the dermal and subcutaneous tissue. The maximum diameters of the tumours ranged from 3.5 to 8.0 cm. Microscopically, all tumours showed moderate hypercellularity, an increased nuclear to cytoplasmic ratio, and hyperchromasia, but exhibited varied growth patterns, including those that were atypical neurofibroma-like, low grade fibromyxoid sarcoma-like, low grade epithelioid, and haemangiopericytoma-like. All tumours showed immunoreactivity for S-100 protein and vimentin. CONCLUSIONS: These findings suggest that careful clinical and histological evaluation, along with S-100 protein immunostaining, are essential for the accurate diagnosis of low grade MPNST.