Amino acid residues conferring the nucleotide binding properties of N-acetyl-D-glucosamine 2-epimerase (renin binding protein)

Our recent studies have demonstrated that the middle domain of N-acetyl-D-glucosamine (GlcNAc) 2-epimerase participates in the specificity for and binding of nucleotides. To identify the residue conferring nucleotide binding, amino acid substitutions were introduced in the human and rat GlcNAc 2-epimerases. The mutational analyses indicate that residue 171 of GlcNAc 2-epimerase is critical for the nucleotide binding of GlcNAc 2-epimerase.     

Strong Telomerase Activity of B Lymphocyte from Mesenteric Lymph Nodes of Patients with Inflammatory Bowel Disease

Telomerase acitivity can be induced in human B lymphocytes by in vitro stimulation of their antigen receptors. To determine whether telomerase activity is induced in vivo, we analyzed telomerase activity in B lymphocytes from the mesenteric lymph nodes of patients with inflammatory bowel disease (IBD), whose lymph nodes are well known to be strongly stimulated, and from those of noninflamed controls. Seven IBD patients and 4 noninflamed controls were enrolled. Telomerase activity was assayed by telomeric repeat amplification protocol with minor modifications. The mesenteric lymph nodes from patients with IBD had stronger telomerase activity than those from controls or peripheral mononuclear cells. Isolation of CD19⁺ B lymphocytes from these lymph nodes showed that this strong activity resides in this lymphocytes subpopulation. This study provides the evidence that telomerase activity is induced in human B lymphocytes in human inflammatory disease.     

A juvenile case of epilepsy-associated,isocitrate dehydrogenase wild-type/histone 3 wild-type diffuse glioma with a rare BRAF A598T mutation

Here, we report a juvenile (18-year-old male) case of epilepsy-associated, isocitrate dehydrogenase wild-type/histone 3 wild-type diffuse glioma with a rare BRAF mutation and a focal atypical feature resembling diffuse astrocytoma. The patient presented with refractory temporal lobe epilepsy. Subsequently, magnetic resonance imaging revealed a hyperintense lesion in the right temporal lobe on fluid attenuated inversion recovery images. The patient underwent right lateral temporal lobectomy and amygdalohippocampectomy. Histopathologically, the tumor showed isomorphic, diffuse, infiltrative proliferation of glial tumor cells and intense CD34 immunoreactivity. The tumor cells were immunonegative for isocitrate dehydrogenase 1 (IDH1) R132H and BRAF V600E. Notably, the tumor cells showed the lack of nuclear staining for α-thalassemia/mental retardation syndrome, X-linked (ATRX). In addition, the Ki-67 labeling index, using a monoclonal antibody MIB-1, was elevated focally at tumor cells with p53 immunoreactivity. Molecular analyses identified a BRAF^A598T mutation, the first case reported in a glioma. BRAF^A598T is predicted to result in loss of kinase action; however, inactive mutants can stimulate mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) signaling through CRAF activation. Thus, according to the recent update of the consortium to inform molecular and practical approaches to central nervous system tumor taxonomy (cIMPACT-NOW update 4), our case is also compatible with diffuse glioma with the mitogen-activated protein kinase (MAPK) pathway alteration. Thorough immunohistochemical and molecular studies are necessary for diagnosis of epilepsy-associated, diffuse gliomas. Partial resemblance in histopathological and molecular genetic features to diffuse astrocytoma also calls for attention.     

Resistance of germinal nucleus to aging in Paramecium: Evidence obtained by micronuclear transplantation

A diversity of time when increase in mortality after conjugation occurs during the lifespan was found in subclones of three stocks of Paramecium caudatum. A possible micronuclear contribution to the increase in sterility has been investigated by micro-nuclear transplantation. We found two classes of micronuclei in aged clones: those that can function normally if the cytoplasmic environment is young, and those that cannot, even in a young cytoplasmic environment. The results indicate that in the former, the age-dependent increase in sterility is due to a deleterious macronucleus and/or cytoplasm, and in the latter it is due to micronuclear damage. The micronuclear damage in aged clones is probably induced by a deleterious cytoplasmic environment because aged clones with transplanted young micronuclei showed an abrupt decrease in progeny survival between 14 and 42 cell divisions after transplantation. Overall, the micronucleus seems not to be a source of age-related damage but rather is subjected to damage from macronuclear and/or cytoplasmic sources.     

Kyphoplasty versus vertebroplasty to increase vertebral body height: a cadaveric study

PURPOSE: To prospectively compare the vertebral height restoration achieved with kyphoplasty and vertebroplasty in fresh cadavers by using multi-detector row computed tomography (CT). MATERIALS AND METHODS: Institutional review board approval was not required because the donors had registered in and consented to an anatomic gift program prior to their death. Thirty-seven vertebrae were harvested from four donated cadavers of elderly female individuals (mean age, 82 years; age range at death, 73-87 years). The vertebrae were dissected free of the surrounding muscles and imaged with multi-detector row CT. Compression fractures were induced, and the vertebrae were again imaged. The vertebrae were randomized to be treated with kyphoplasty (n = 19) or vertebroplasty (n = 18) and were then imaged at multi-detector row CT. The anterior, central, and posterior vertebral body heights and wedge angles were measured in the midsagittal plane of the reformatted images. The amount of cement injected was determined by weighing the vertebrae before and after treatment. The statistical significance of changes in vertebral body height, wedge angle, and weight with the two treatment techniques was evaluated with the independent t test or Mann-Whitney U test. RESULTS: The increase in vertebral height was greater with kyphoplasty than with vertebroplasty (5.1 mm vs 2.3 mm, respectively; P < .05). The original vertebral height was restored in 93% of vertebrae with kyphoplasty and in 82% with vertebroplasty (P < .05). There was a greater decrease in wedge angle with kyphoplasty than with vertebroplasty (3.1 degrees vs 1.6 degrees, respectively); however, this difference was not significant (P > .05). There was no significant difference in the amount of cement injected with kyphoplasty and vertebroplasty (P > .05). CONCLUSION: Kyphoplasty increased vertebral body height more than vertebroplasty in this model of acutely created fractures in fresh cadaver specimens.