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Biomedical subjects

N Mori

Publications and source records attributed to N Mori.

At least 235 records · Page 13Linked to original sources
PubMed1998

Coexisting primary early gastric plasmacytoma and sarcoidosis with hypercalcaemia.

We report on a 61-year-old woman with coexisting early stage primary gastric plasmacytoma and sarcoidosis with hypercalcaemia. Laboratory data on admission showed hypercalcaemia, with 12.8 mg/dl, parathyroid hormone-related peptide (PTHrP) 1.2 pmol/l, C-PTHrP 69.5 pmol/l, and 1,25-dihydroxyvitamin D3 46.7 pg/ml. Neoplastic plasma cells proliferated in the propria mucosa of the stomach, showed a monoclonal immunoglobulin of cytoplasmic IgA (lambda light chain) and were positive for leucocyte common antigen and epithelial membrane antigen on paraffin section prepared from a stomach biopsy specimen. Russel bodies were present, as were crystals. Abundant sarcoid granulomas were observed in many of the regional lymph nodes around the stomach and in the dermis of a skin nodule. The patient underwent subtotal gastrectomy with administration of antimyeloma chemotherapy. We suggest that the hypercalcaemia in this patient was due to PTHrP production by neoplastic plasma cells.

Cholecalciferol↗
PubMed1998

Vascular leiomyosarcoma arising from the inferior vena cava diagnosed by intraluminal biopsy.

A 61-year-old woman developed pain in the right thigh, paraplagia of the lower extremities and lumbago in November 1996. A lumbar spine roentgenogram showed lytic change in L2, and magnetic resonance imaging showed a patchy destructive lesion and compression of the dural sac from the right by a tumour. Computed tomography (CT) myelography showed a motheaten destructive lesion in L2 and projection of the tumour into the spinal canal. Abdominal ultrasound, CT and cavography showed dilatation of the inferior vena cava (IVC) and an intraluminal tumour about 2x2.8x4 cm in size in the IVC. The tumour arose from the IVC just beneath the renal vein and extended to just short of the right atrium. Both vertebral and intraluminal biopsy materials showed the same morphology, in which atypical spindle cells admixed with multinucleated giant cells proliferated in a fascicular growth pattern. Neoplastic cells were strongly positive for alpha-smooth muscle actin. We diagnosed vascular leiomyosarcoma arising from the IVC with metastasis to the lumbar vertebrae. Cases of vascular leiomyosarcoma diagnosed by intraluminal biopsy are rare.

Biopsy↗
PubMed1998

Mucosal bile duct carcinoma with superficial spread.

We describe a case of mucosal bile duct carcinoma with superficial spread in a 69-year-old man with gallstone pancreatitis. The patient was seen at the hospital because of abdominal pain, fever, and jaundice. Endoscopic retrograde cholangiography (ERC) demonstrated a protruding lesion in the lower third of the common bile duct (CBD) showing wall irregularity suggestive of malignancy. Percutaneous transhepatic cholangioscopy (PTCS) disclosed a papillary tumor with granular mucosa extending continuously to the middle third of the CBD. Cholangioscopic biopsy specimens taken from both the papillary tumor and surrounding granular mucosa revealed papillary adenocarcinoma. After this assessment of extent of cancer by PTCS, we performed pancreatoduodenectomy with extrahepatic bile duct resection and regional lymph node dissection. Pathology examination revealed papillary adenocarcinoma limited to the mucosal layer. The resected margin of the bile duct was free of tumor. We also reviewed 25 cases of early mucosal bile duct carcinoma described in detail in the Japanese literature, and we discuss the diagnostic advantages of PTCS.

Adenocarcinoma, Papillary↗
PubMed1998

Alternative expression of Shc family members in nerve-injured motoneurons.

Expression of Shc family protein (Shc/ShcA, SCK/ShcB and N-Shc/ShcC) and Grb2 mRNAs in the hypoglossal motoneurons after axotomy was examined by in situ hybridization. In normal hypoglossal motor neurons, N-Shc mRNA was expressed predominantly, whereas the Shc mRNA level is very low. Rat hypoglossal nerve injury reversed the expressions of these two molecules in hypoglossal motoneurons. Shc mRNA expression was up-regulated markedly whereas N-Shc was down-regulated after nerve injury. Expression levels of SCK, another Shc family member, and Grb2 were unaffected by nerve injury. These results suggest that, whereas the N-Shc-mediated pathway dominates under normal conditions, an alternative Shc-mediated pathway is utilized in the event of nerve injury. By changing the expression of the Shc family members, the signaling pathway can be altered and various responses induced for nerve regeneration.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Expression of mRNA encoding vasopressin V1a, vasopressin V2, and ANP-B receptors in the rat cochlea.

The expression of mRNAs encoding vasopressin V1a, V2, and ANP-B receptors in the rat cochlea was examined by PCR and in situ hybridization. After reverse-transcription of rat cochlear RNA, cDNA was amplified by PCR using pairs of primers specific to these receptors. After subcloning of the PCR products, clones with sequences identical to those cloned previously from the rat liver (V1a receptor), kidney (V2 receptor) and brain (ANP-B receptor) were obtained. The localization of expression of those receptors in the developing and adult rat cochlea was examined by in situ hybridization using 35S-labeled cRNA probes. The V1a and V2 receptors were expressed throughout the whole of the neonatal rat cochlea, while no expression was detected in the adult cochlea. The ANP-B receptor was expressed throughout the whole of the neonatal cochlea. In the adult cochlea, expression was observed in the spiral ganglion and the spiral ligament. These results suggest that vasopressin may play a role in the development of the cochlea, and that natriuretic peptide may play a role in the function of the spiral ganglion and the spiral ligament.

Aging↗
PubMed1998

In vivo analysis of hydrogen peroxide and lipid radicals in the striatum of rats under long-term administration of a neuroleptic.

It has been hypothesized that free radicals play a causative role in tardive dyskinesia, which is an inveterate movement disorder caused by chronic administration of neuroleptics. To verify this hypothesis, rats were reared while being regularly treated with water containing a neuroleptic, haloperidol (HPD), for 1 year (HPD group). The changes in the striatal hydrogen peroxide content of the rats in the HPD and control groups were measured by using a Pt-disk microelectrode while the animals were in a freely moving state following intraperitoneal administration of HPD (HPD challenge). We also performed electron spin resonance (ESR) detection of lipid radicals in the striatum before the HPD challenge. HPD challenge led to significant elevation of the intrastriatal hydrogen peroxide in all animals, but the elevation in the HPD group was smaller than that in the control group. However, in the HPD group, marked ESR signals of intrastriatal lipid radicals were observed. We think that these results support the hypothesis on the role of free radicals in tardive dyskinesia.

Animals↗
PubMed1998

Stress protein-induced immunosuppression: inhibition of cellular immune effector functions following overexpression of haem oxygenase (HSP 32).

This is the first report on suppression of immune effector functions following upregulation of heat shock protein 32 (HSP 32), known as haem oxygenase (HO-1). Here we evaluated the effect of cobalt-protoporphyrin (CoPP)-induced HO-1 expression on cell-mediated immune responses. Administration of CoPP to CBA mice resulted in overexpression of HO-1 in the spleen, liver and kidneys. In vitro measurements of T cell-mediated and NK-cell-mediated cytotoxicity in spleens from CoPP-treated animals demonstrated a severe suppression of their effector functions while administration of Zn-PP or vitamin B12 had no effect. Furthermore, CoPP therapy decreased the lymphoproliferative alloresponse and differentiation of cytotoxic T cells. Inhibition of proliferation appeared to be due to cell growth arrest with an increased number of cells staying in G0/G1 phase. Despite the suppressed proliferative response, IL-2 production in the MLR was not inhibited. In contrast, CoPP decreased the production of IL-10, IFN-gamma and TNF-alpha. In vivo, CoPP prolonged the survival of heterotopic heart allografts in mice. The immunosuppressive effects following CoPP-mediated upregulation of HO-1 were similar to those observed after peptide-mediated upregulation of HO-1. The results indicate that overexpression of HO results in the inhibition of several immune effector functions and thus provides an explanation for stress-induced immunosuppression.

Animals↗
PubMed1998

Membrane potential in isolated epithelial cells of the endolymphatic sac in the guinea-pig.

The membrane potential (Em) in epithelial cells isolated from the intermediate portion of the endolymphatic sac (ES) of the guinea-pig was recorded using the whole-cell patch-clamp technique. In the steady state the Em was -53.5+/-1.5 mV (n = 74), which is similar to that in epithelial cells of other tissues. Application of 1 MM ouabain induced a depolarization of Em by approximately 10 mV (n = 6), suggesting that an active ion transport process by Na+-K+-ATPase may be present in the ES epithelial membrane. Increasing extracellular K+ concentrations from 5 to 100 mM induced a significant membrane depolarization that was close to the K+ equilibrium potential calculated by the Nernst equation, indicating that K+ may be a predominant permeable ion in the ES epithelial membrane. Total replacement of extracellular Na+ with NMDG+ led to a significant membrane hyperpolarization of 38.7+/-2.5 mV (n = 18), suggesting that Na+ may be another major permeable ion for the ES epithelial membrane. Reducing extracellular Cl- concentrations from 149.3 to 7 mM had no significant effect on Em, indicating that Cl- may be a negligible permeable ion in the ES epithelial membrane.

Animals↗
PubMed1998

Effect of endoplasmic Ca2+-ATPase inhibitors on cochlear potentials in the guinea-pig.

The effect of endoplasmic Ca2+-ATPase inhibitors on cochlear potentials was examined in the guinea-pig. Perilymphatic perfusion with thapsigargin (10[-6] M) produced a significant decrease in the amplitudes of cochlear microphonics, negative summating potential and compound action potential, and a significant prolongation of N1 latency with no change in the endocochlear potential. These changes were all dose dependent. Another endoplasmic Ca2+-ATPase inhibitor, cyclopiazonic acid (10[-5] M), produced the same effects as thapsigargin on cochlear potentials. These results suggest that endoplasmic Ca2+-ATPase inhibitors may have inhibitory functions on cochlear potentials.

Animals↗
PubMed1998

The process of otoconia formation in guinea pig utricular supporting cells.

In order to clarify the mechanism of otoconia formation, the pathway of calcium transport in the utricular supporting cells was investigated. Potassium pyroantimonate (PA) precipitation, which indicates the localization of calcium ions, was seen not only in otoconia but also in supporting cell cytoplasm. In the latter, deposits of PA were detected in the secretory granules and endoplasmic reticulum (ER). These deposits were not present in cells pretreated with ethylene glycol-O,O,-bis (2-aminoethyl)-N,N,N',N'-tetra-acetic acid (EGTA). Exposure of the supporting cells to streptomycin sulfate (SM) increased the number of lysosomes. These lysosomes contained many small deposits of PA. The remaining granules and ER in cytoplasm also contained small deposits of PA. The findings suggest that otoconia are formed by the vestibular supporting cells in which calcium ions might be transported via ER-secretory granule-lysosome-cytoplasmic protrusion.

Animals↗
PubMed1998

The effect of forskolin on the sound-evoked potentials in the guinea pig cochlea.

The effect of forskolin (FSK) on cochlear sound-evoked potentials was examined in the guinea pig. The perfusion of the scala vestibuli (SV) with FSK (2 x 10(-4) M) produced a significant increase in the amplitude of negative summating potential (- SP) with no change in cochlear microphonics (CM) amplitude, and a significant decrease in the amplitude of compound action potential (CAP) with a significant prolongation of N1 latency and a 20 dB CAP threshold elevation. The results lead us to speculate that FSK-induced changes may be involved in the transient formation of endolymphatic hydrops.

Animals↗
PubMed1998

Failure of forskolin to elevate the endocochlear potential in experimental endolymphatic hydrops of the guinea pig.

The effect of forskolin (FSK) on the endocochlear potential (EP) in scala media (SM) was examined in experimental endolymphatic hydrops of the guinea pig. Two weeks after obliteration of the endolymphatic sac the EP of hydroptic ears and that of the contralateral control ears were measured by means of microelectrodes. The perfusion of scala vestibuli (SV) with FSK (200 microM) produced EP elevation in the contralateral control ears but failed to do so in the experimental hydroptic ears. Histological examination of experimental endolymphatic hydrops showed mild hydrops with intact appearance of outer and inner hair cells, and the stria vascularis. The mechanism underlying the failure of FSK to elevate the EP in experimental endolymphatic hydrops is discussed.

Animals↗
PubMed1998

Detection and sequence analysis of borna disease virus p24 RNA from peripheral blood mononuclear cells of patients with mood disorders or schizophrenia and of blood donors.

Borna disease virus (BDV) p24 RNA was detected in the peripheral blood mononuclear cells (PBMCs) of psychiatric patients and blood donors by nested reverse transcriptase PCR (RT-PCR). The prevalences of BDV p24 RNA in patients with mood disorders (4%) and schizophrenia (4%) were not significantly different from that in blood donors (2%). This finding was inconsistent with previous reports that showed either a high prevalence or absence of BDV p24 RNA in patients with psychiatric disorders. The differences in BDV p24 RNA prevalence in these studies may be due to differences in the criteria for positivity, the number of PBMCs used for RNA extraction, or the amount of RNA tested for nested RT-PCR or to laboratory contamination. Sequence analysis of BDV p24 RNA from the PBMCs of patients and blood donors showed a high nucleotide sequence conservation but definite nucleotide mutations compared with horse BDV p24 RNA sequences. In comparison with human BDV p24 RNA sequences previously reported from Japan and Germany, there were several positions with silent nucleotide mutations among these clones.

Adult↗
PubMed1998

Interleukin-10 gene expression and adult T-cell leukemia.

Numerous studies have shown spontaneous IL-10 gene expression and synthesis in a variety of peripheral blood or bone marrow-derived leukemic cells. These include B-cells derived from various lymphoproliferative disorders. Since little is known regarding IL-10 expression in leukemic T-cells, we examined clinical specimens of patients with adult T-cell leukemia (ATL) for IL-10 expression. Sera from ATL patients show increased levels of IL-10 when compared with sera from healthy donors. IL-10 is constitutively produced by ATL cells and also by human T-cell leukemia virus type I (HTLV-I)-infected cell lines. It is thought that HTLV-I infection induces gene expression for IL-10. In this review, a transcriptional regulation of IL-10 gene expression by HTLV-I Tax and the possible role of the NF-kappaB pathway are described.

Gene Products, tax↗
PubMed1998

A common protocadherin tail: multiple protocadherins share the same sequence in their cytoplasmic domains and are expressed in different regions of brain.

To study the diversity of protocadherins, a rat brain cDNA library was screened using a cDNA for the cytoplasmic domain of human protocadherin Pcdh2 as a probe. The resultant clones contained three different types. One type corresponds to rat Pcdh2; the other two types are distinct from Pcdh2 but contain the same sequence in their cytoplasmic domains and part of the 3' flanking sequence. To clarify the structure of the proteins defined by the new clones, a putative entire coding sequence corresponding to one of the clones was determined. The overall structure is essentially the same as Pcdh2, indicating that the proteins defined by this clone, and probably by other clones, belong to the protocadherin family. Two PCR experiments and an RNase protection assay showed the existence of the corresponding mRNAs in rat brain preparations. Human and mouse cDNA clones with the same sequence properties were also isolated. Taken together, these results indicate that the clones are not cloning artifacts and that corresponding mRNAs are actually expressed in brains of various species. The results of in situ hybridization showed that the mRNAs corresponding to these clones were expressed in different regions in brain. Since protocadherins encoded by these mRNAs are likely to have different specificity in their interaction and share a common activity at their cytoplasmic domains, these protocadherins may provide a molecular basis, in part, to support the complex cell cell interaction in brain.

Amino Acid Sequence↗
PubMed1998

Perforin and granzyme expression in cytotoxic T-cell lymphomas.

We studied the morphologic and immunohistochemical features of 10 peripheral T-cell lymphomas of a cytotoxic phenotype (CD3+/CD4-/CD8+), encountered among 98 peripheral T-cell lymphomas (PTCLs). Nine tumors were positive for both cytotoxic molecules, namely perforin (Pf) and granzyme B (GrB), and strong positivity was seen in the majority of the malignant cells. We also studied the expression of these molecules in 92 other cases of T-cell and natural killer (NK) cell neoplasms; 18 anaplastic large cell lymphomas (ALCLs); 63 CD4+ PTCLs; 10 CD56+ nasal lymphomas; and 1 NK-cell leukemia. Most of the CD4+ PTCLs (62 of 63) were negative for GrB, but all of the nasal lymphomas and the NK cell leukemia were positive for both Pf and GrB. Variable expression was seen among the 18 ALCLs. Within the 10 CD8+ PTCLs, 4 involved the skin, 3 of which were diagnosed as primary cutaneous lymphomas. Five patients died within 1 year of diagnosis. According to the Revised European-American Classification of Lymphoid Neoplasms, seven cases were categorized as "PTCL, unspecified," and three as "angioimmunoblastic T-cell lymphoma," "adult T-cell lymphoma/leukemia," or "small cell lymphoma," respectively. Three cases had characteristic morphologic features consisting of large lymphomatous cells with massive necrosis and nuclear fragmentation. Epstein-Barr virus mRNA was detected by in situ hybridization in three cases. Although the degree of apoptosis varied, apoptotic cells were detected in all cases by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate-biotin nick end labeling. We conclude that CD8+ PTCLs are relatively rare, often involve extranodal sites, have an aggressive clinical course, and are often associated with Epstein-Barr virus. Compared with ALCLs, which have recently been considered as neoplasms of cytotoxic T-cells, we think that CD8+ PTCLs are more lineage-specific neoplasms of mature, cytotoxic, T lymphocytes.

Adult↗
PubMed1998

[Perioperative minimum acceptable hematocrit level in highly invasive head and neck surgery].

We examined the perioperative balance between oxygen delivery and oxygen consumption under hemodilution in 24 patients who underwent head and neck surgery of long duration and with massive blood loss. Intraoperative mixed venous oxygen saturation (SVO2), which decreased according to a decrease in hematocrit (Hct), was almost always kept above 60% when Hct was more than 20%. The longer the duration of surgery, the lower was SVO2 at the end of surgery. Postoperative SVO2 correlated positively with SVO2 at the end of surgery, and negatively with the duration of surgery and blood loss, but did not correlate with Hct. In 9 cases, SVO2 at the recovery from anesthesia decreased to below 60%, because oxygen consumption increased remarkably with shivering. These results suggest that in highly invasive head and neck surgery, the intraoperative minimum acceptable Hct level is 20%. On the other hand, there is no general postoperative minimum acceptable Hct level, because postoperative oxygen demand and supply balance depends on the degree of surgical invasion and increase of VO2. SVO2 at the end of surgery is useful in predicting postoperative oxygen demand and supply balance.

Aged↗