Characterization and Modification of Brain Activity with Deep Brain Stimulation in Patients in a Persistent Vegetative State: Pain-Related Late Positive Component of Cerebral Evoked Potential

A series of eight patients in a persistent vegetative state (PVS) were subjected to chronic deep brain stimulation (DBS) for the purpose of promoting recovery from the PVS. The characteristics of the brain activity in these patients were evaluated from the late positive component of the cerebral evoked potential in response to painful stimuli (pain-related P250). While any neurological scoring system for the comatose state includes evaluations of motor reactions to painful stimuli, the pain-related P250 is unique in terms of its ability to assess the cortical responsiveness to painful stimuli directly and quantitatively without involving functions of the motor system. It was found that the pain-related P250 was more or less depressed in patients in a PVS. It was repeatedly demonstrated in four patients, however, that the pain-related P250 could be transiently increased by preceding stimulation of the mesencephalic reticular formation. Furthermore, a persistent increase in the pain-related P250 was produced in these four patients following chronic DBS of the mesencephalic reticular formation or nonspecific thalamic nuclei for more than 6 months, and this was correlated with the clinical improvements. These results imply that responsiveness at the cortical level to pain is depressed in the PVS. It also appears that some fraction of the depression may, however, be functionally produced and potentially reversible.     

Preparations,solution conformations and molecular structures of N,N′-ethylene-bridged dipeptides and their derivatives

The solution conformations of novel dipeptides, methyl (2S, 3′S)-3-methyl-2-(2′-oxo-3′-isopropyl-1′-piperazinyl)-butanoate (EVV-OCH₃), methyl (2S, 3′S)-3-phenyl-2-(2′-oxo-3′-benzyl-1′-piperazinyl) propionate (EFF-OCH₃), and their derivatives (Boc-Gly-EW-OH, Boc-Gly-EVV-Gly-OH, and Boc-Gly-EFF-OH), were studied by ‘H NMR measurements and molecular mechanics calculations (1). The molecular structures of Boc-Gly-EVV-OH, Boc-Gly-EFF-OH, and the hydrochloride of EVV-OCH₃ were determined by X-ray analyses. The conformations of the piperazinone rings and the side chains of these oligopeptides were clarified.     

Expression of stem cell factor in basal cell carcinoma

Summary Stem cell factor (SCF) distribution in basal cell carcinomas (BCCs) was examined by immunohisto-chemistry. Eighteen BCCs (11 nodular, three superficial, two cystic, one adenoid and one morphoeic type) showed positive expression of SCF in the tumour islands. The centre of the tumour island was strongly positive in nodular, superficial and morphoeic types. In cystic BCCs. SCF-positive tumour cells were also located in the peripheral lesion around the cystic space. SCF was also detected on fibroblast-like cells and mast cells in the stroma. SCF was positively stained within the upper keratinocytes in the overlying epidermis, more strongly as compared with normal skin. The mast cell number (mean ± SD)) was significantly increased in the peritumoral stroma (85.7 ± 28. 3/mm²) compared with normal skin (32.1 ±4.2/mm²) ( P <0.005). SCF was also positive in the tumour nests of four cases of trichoepithelioma, in which fibrosis of the surrounding stroma was found histologically. This study demonstrates that abundant SCF produced by the tumour cells may account for the increased number of stromal mast cells, which induce fibroplasia of the surrounding stroma.     

The Cochlear Pericytes

Objectives : Cochlear pericytes are not well characterized. The aim of this study was to further advance the characterization of cochlear pericyte location and distribution, with particular focus on pericyte‐related proteins on the capillaries of the cochlear lateral wall that are functionally integral to structure, contraction, and gap junction transport. Materials and Methods : Cochlear pericytes were identified by the immunofluorescence labeling of pericyte marker proteins, including alpha–smooth muscle actin (α‐SMA), desmin, Thy‐1, tropomyosin, and NG2, and by morphological identification, using fluorescence, electron, and differential interference contrast microscopy. Results : Pericytes were predominately found in the capillary network of the cochlear lateral wall, with considerable morphological heterogeneity across different types of microvessels. For example, pericytes on the vessels of the spiral ligament (V/SL) strongly expressed a gap junction protein, connexin 40, and were positive for α‐SMA, tropomyosin, and desmin. In contrast, pericytes on the vessels of the stria vascularis (V/SV) were positive for desmin, and were negative for α‐SMA and tropomyosin. Conclusions : The capillary networks of the cochlear lateral wall comprise a rich population of pericytes. These pericytes are morphologically heterogeneous, with protein expression potentially indicative of function.     

The Predictive Value of Chromosome 8p Deletion for Metastasis of Hepatocellular Carcinoma:A Summary of 10 Years'' Works

Hepatocellular carcinoma (HCC) represents an extremely poor prognostic cancer, which is mainly due to the high frequency of metastasis/recurrence after surgical operation. To detect the specific chromosome alterations     

A Small Polyp of Brunner's Gland Hyperplasia Causing Hemorrhage

Abstract: A rare case of a small Brunner's gland hyperplasia (BGH) of the duodenum which represented hemorrhage is presented. An 84-year-old male was admitted because of tarry stool and anemia. Endoscopic examination revealed a small, subpedunculated duodenal polyp with blood and clots on its surface, which was considered responsible for the tarry stool. The lesion was polypectomized without any complications. Since complications of BGH including bleeding and obstruction, are more likely to occur as the size of the lesion increases, small BGH lesions tend to be regarded as benign and are left alone in clinical settings. The present case showed the possibility that such a seemingly harmless small polyp may eventually lead to massive hemorrhage. (Dig Endosc 1999; 11: 52–54)     

Fyn and Lck tyrosine kinases regulate tyrosine phosphorylation of p105CasL, a member of the p130Cas docking protein family, in T-cell receptor-mediated signalling

We have previously shown that engagement of the T-cell receptor (TCR)/CD3 complex with anti-CD3 antibody induces tyrosine phosphorylation of p105CasL (CasL), a member of the p130Cas docking protein family. In the present work, we attempted to determine which protein tyrosine kinases (PTKs) regulate TCR-mediated phosphorylation of CasL. We show here that an association between CasL and two types of Src family PTKs, Fyn and Lck, is induced by anti-CD3 cross-linking of human H9 T cells. In contrast, ZAP-70, another PTK that also plays a critical role in the TCR signalling, failed to bind CasL, even after anti-CD3 stimulation. In vitro kinase assays revealed that Fyn and Lck, but not ZAP-70, were capable of phosphorylating CasL. Moreover, we found that CasL was constitutively hyperphosphorylated in vivo in splenocytes of MRL-MP-lpr/lpr mice, in which overproduction and excessive activation of Fyn and Lck have previously been shown to occur. Constitutive in vivo binding of CasL to both kinases was also demonstrated in lpr splenocytes. These results strongly suggest that CasL is a substrate for Fyn and Lck PTKs in TCR signal transduction.     

COMMENTS

Testicular dysgenesis syndrome encompasses low sperm quality, hypospadias, cryptorchidism and testicular cancer. Epidemiological studies and genetic data from familial cases suggest that testicular dysgenesis syndrome has a common etiology. The Y chromosome is known to encode genes that are involved in germ cell development or maintenance. We have therefore investigated if different classes of Y chromosomes in the general population (Y chromosome haplogroups) are associated with aspects of the testicular dysgenesis syndrome. We defined the Y chromosome haplogroups in individuals from different European counties who presented with either (i) oligo- or azoospermia associated with a Y chromosome microdeletion, (ii) unexplained reduced sperm counts (<20 x 10(6)/ml) or (iii) testicular cancer. We failed to find Y chromosome haplotype associations with either microdeletion formation or testicular cancer. However, in a study of the Danish population, we found that a specific Y chromosome haplogroup (hg26) is significantly overrepresented in men with unexplained reduced sperm counts compared with a Danish control population. The factors encoded by genes on this class of Y chromosome may be particularly susceptible to environmental influences that cause testicular dysgenesis syndrome. Our current data highlight the need for further analyses of clinically well-defined patient groups from a wide range of ethnic and geographic origins.