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H Ohishi

Publications and source records attributed to H Ohishi.

At least 19 recordsLinked to original sources
PubMed2003

Extranodal lymphoblastic lymphoma of suspected B-cell lineage in the gingiva of a racehorse, accompanied by mandibular osteolysis.

A mass developed in the mandibular gingiva of a thoroughbred racehorse. When the horse could no longer eat unassisted, it was killed and immediately autopsied. Macroscopically, the mandible exhibited extensive osteolysis, with only a small amount of bone remaining around the tooth roots. The cut surface of the mass around the mandible consisted of neoplastic medullary tissue, in which osteogenesis was observed. The medullary tissue was composed of pleomorphic medium-sized to large cells, interlaced by collagen bundles. These cells had large, pale, round or ovoid, sometimes cleaved nuclei, with one or two prominent nucleoli. Mitoses were numerous. Electron microscopy showed that the cells in the medullary tissues were similar in shape to undifferentiated lymphocytes. Immunohistochemically, these cells were positive for B-cell associated antigen in the pre-B-cell stage. Our findings suggest that the horse had extranodal lymphoblastic lymphoma of suspected B-cell lineage, possibly originating from the lymphatic system of the gingiva. We consider that the osteolysis resulted from activation of osteoclasts by proliferation of the tumour cells.

Animals↗
PubMed2001

Brainstem auditory regions in mice: expression of nociceptin/orphanin FQ precursor mRNA in select neurons.

Nociceptin peptide-receptor system is known to be essential for the regulation of hearing ability. The mRNA for nociceptin precursor protein is highly expressed in the brainstem. We explored a detailed hybridohistochemical expression pattern of the nociceptin precursor mRNA in the mouse brainstem, and identified positive cells in several auditory brainstem nuclei. Positive cells were seen in the dorsal and ventral nuclei of the lateral lemniscus, the rostral periolivary region, the lateroventral and medioventral periolivary nuclei, the dorsal periolivary region, the superior paraolivary nucleus, and the external cortex and dorsal cortex of the inferior colliculus. Of these, the medioventral and lateroventral periolivary nuclei, the major sites of origin of olivocochlear bundle, were most populated by positive cells.

Animals↗
PubMed2001

Stereospecific 1,3-migration of an Fe(CO)3 group on acyclic conjugated polyenes: application to remote and iterative asymmetric induction.

The stereochemical outcome of the 1,3- and 1,5-migration of an Fe(CO)3 group on (acyclic polyene)Fe(CO)3 complexes and their application to stereoselective construction of remote and contiguous stereogenic centers are described. Treatment of the [(eta(4)-4-7)triene]Fe(CO)3 complexes 1a-d bearing an electron-withdrawing group on the terminal position of an uncomplexed olefin with a base such as KN(SiMe3)2 (KHMDS) and LiCH2CN induced the 1,3-migration reaction of the Fe(CO)3 group, giving the [(eta4-2-5)triene]Fe(CO)3 complexes 2a-d in moderate to good yields, depending on the electron-withdrawing groups. From an experiment using the chiral (trienenitril)Fe(CO)3 complex 5, it is revealed that the 1,3-migration proceeds with inversion of configuration. Similarly, the 1,5-migration reaction of the[(eta4-6-9)tetraenone]Fe(CO)3 complexes 9 occurred with a catalytic amount of KHMDS, giving the [(eta4-2-5)tetraenone]Fe(CO)3 complexes 10 with retention of configuration. Furthermore, we have succeeded in the first regio- and stereoselective nucleophilic substitution of the (3,5-diene-1,2-diol) Fe(CO)3 complexes (15 --> 24a-h) with various nucleophiles via the ortho esters 21. By using iterative manipulation of the above two reactions, remote stereocontrol of the terminal substituents on acyclic polyene (9 --> 12) and construction of contiguous stereogenic centers (19, 28) have been achieved.

Journal Article↗
PubMed2001

Asymmetric total synthesis of halicholactone.

The asymmetric total synthesis of the marine metabolite, halicholactone 1, is described. The bisallylic triol 6 with three chiral centers at C8, C12, and C15 was constructed by [2,3]-sigmatropic rearrangement of the sulfoxide 18, which was prepared stereoselectively using the chirality of (diene)Fe(CO)3 complexes. Introduction of the trans-substituted cyclopropane subunit into 21 was successfully achieved using the modified regio- and stereoselective Simmons-Smith reaction. The use of RCM (ring-closing metathesis) methodology (4-->35) was pivotal for the formation of a nine-membered unsaturated lactone fragment of halicholactone 1. As this approach is flexible and stereoselective, other oxylipins could be synthesized by the protocol described herein.

Animals↗
PubMed2001

Detection of early venous filling in gliomas on MRI: preliminary study by 2D time-resolved dynamic contrast-enhanced MR angiography with echo-sharing technique.

We evaluated the detection of early venous filling of gliomas by 2D time resolved dynamic contrast enhanced MR digital subtraction angiography (MR-DSA) with echo-sharing technique and compared the results with those of conventional contrast digital subtraction angiography (C-DSA). C-DSA and MR-DSA examinations were performed in eight patients with malignant gliomas and compared with regard to the visualization of early filling veins; time intensity curves of arteries, early filling veins and normal veins were made, and rise time and time to peak were evaluated. MR-DSA visualized 12 out of 17 early filling veins depicted on C-DSA. The failure of five veins to be depicted may be due to the overlapping of other structures, such as other vessels and tumor stain. On time intensity curves, the mean difference in rise time was 0.9 sec between the artery and early filling vein, and the mean difference of time to peak was 1.6 sec. C-DSA has been the modality of choice in demonstrating early venous filling, a useful finding in the differential diagnosis of gliomas. However the high temporal resolution of MR-DSA with echo-sharing technique provides sufficient visualization of early venous filling of gliomas. Additional information for precise differential diagnosis may be obtained by adding MR-DSA to the imaging protocol for gliomas.

Aged↗
PubMed2001

Conformational comparison of mu-selective endomorphin-2 with its C-terminal free acid in DMSO solution, by 1H NMR spectroscopy and molecular modeling calculation.

In order to make clear the structural role of the C-terminal amide group of endomorphin-2 (EM2, H-Tyr-Pro-Phe-Phe-NH2), an endogenous mu-receptor ligand, in the biological function, the solution conformations of endomorphin-2 and its C-terminal free acid (EM2OH, H-Tyr-Pro-Phe-Phe-OH), studied using two-dimensional 1H NMR measurements and molecular modeling calculations, were compared. Both peptides were in equilibrium between the cis and trans isomers around the Tyr-Pro omega bond in a population ratio of approximately/= 1:2. The lack of significant temperature and concentration dependence of NH protons suggested that the NMR spectra reflected the conformational features of the respective molecules themselves. Fifty possible 3D structures for the each isomer were generated by the dynamical simulated annealing method under the proton-proton distance constraints derived from the ROE cross-peaks. These energy-minimized conformers, which were all in the phi torsion angles estimated from J(NHCalphaH) coupling constants within +/- 30 degrees, were then classified in groups one or two according to the folding backbone structures. All trans and cis EM2 conformers adopt an open conformation in which their extended backbone structures are twisted at the Pro2-Phe3 moiety. In contrast, the trans and cis conformers of EM2OH show conformational variation between the 'bow'-shaped extended and folded backbone structures, although the cis conformers of its zwitterionic form are refined into the folded structure of the close disposition of C- and N-terminal groups. These results indicate clearly that the substitution of carboxyl group for C-terminal amide group makes the peptide flexible. The conformational requirement for mu-receptor activation has been discussed based on the active form proposed for endomorphin-1 and by comparing conformational features of EM2 and EM2OH.

Algorithms↗
PubMed2001

Impact of LKM512 yogurt on improvement of intestinal environment of the elderly.

Improvement of the intestinal environment by administration of LKM512 yogurt was examined using polyamine, haptoglobin and mutagenicity as indexes which directly reflect the health condition of the host. The concentration of spermine in feces increased significantly by 3-fold (P<0.05) at week 2 of administration of LKM512 yogurt compared with before administration, and that of putrescine, spermidine, and cadaverine also tended to increase with administration of LKM512 yogurt. The haptoglobin content in feces decreased significantly (P<0.05) at week 2 of administration of LKM512 yogurt, and it showed a negative correlation with the polyamine content, indicating that acute intestinal inflammation was suppressed. Fecal mutagenicity was measured using fecal extract and fecal precipitate. Both preparations showed similar significant decreases (P<0.05) by the administration of LKM512 yogurt, as well as a negative correlation with polyamine content. This result indicated that antimutagenicity due to administration of LKM512 yogurt was not based on binding of the mutagen to the bacterial cell wall. Many reports have suggested that polyamines increased by the administration of LKM512 yogurt led to inhibition of inflammation and antimutagenicity in the intestinal tract.

Aged↗
PubMed2001

Stent-Graft treatment of dissecting aneurysm in association with aortic intramural hematoma: when should the procedure be performed?

PURPOSE: To report 2 cases of stent-graft implantation for localized dissecting aneurysm during the conservative treatment of aortic intramural hematoma. CASE REPORTS: One patient underwent stent-graft implantation for 2 localized dissecting aneurysms about 23 months after symptom onset. Computed tomography (CT) 1 year after the procedure demonstrated aneurysm shrinkage. In the other patient, a localized dissecting aneurysm was treated about 3 months after symptom onset, even though the intramural hematoma had not resolved. CT scanning 3 months after the procedure demonstrated aneurysm shrinkage, but also revealed poor attachment of the distal stent-graft to the aortic wall due to subsequent resolution of the hematoma. CONCLUSIONS: Endograft implantation for treatment of localized dissecting aneurysm associated with aortic intramural hematoma should probably not be performed before the hematoma has completely resolved.

Aortic Dissection↗
PubMed2001

[Usefulness of three-dimensional color Doppler sonography for the differential diagnosis of subpleural lesions].

The purpose of our investigation was to assess the usefulness of three-dimensional color Doppler sonography (velocity mode and power mode) for the differential diagnosis of subpleural lesions. Thirty lesions (11 pneumonias, 5 lung abscesses, 11 primary lung cancers, 3 metastatic lung cancers) were examined. Three-dimensional images were reconstructed by a maximum intensity projection method. Three-dimensional representations of intralesional blood flow became available for all lesions approximately 11 seconds after scanning. In every case, the entire vasculature of the tumor, the pneumonia, the abscess, or the inflamed region of the lung was appreciated more easily from three-dimensional images than from two-dimensional images. We classified the color flow pattern of subpleural lesions depicted by color flow imaging into seven groups. Color flow was depicted better by the three-dimensional color Doppler power mode than the velocity mode. Three-dimensional color flow patterns observed in power mode, patterns of the pneumonias and the lung cancers differed significantly. Our results suggest that the three-dimensional color Doppler power mode is useful for the differential diagnosis of subpleural lesions.

Adult↗
PubMed2001

[Progress in liver surgery].

In the 1980s, new methods such as intra-operative ultrasonography, hemihepatic vascular occlusion and ultrasonically guided subsegmentectomy were introduced in clinical practice for use in hepatic surgery. Because of the progress, surgical resection of hepatocellular carcinomas associated with cirrhosis became safer, and curativity and hepatic functional preservation were promoted. The long-term survival rate after operation has improved. Recently, the use of the procedures of vascular surgery transplant surgery has allowed the indication for hepatectomy to be expanded. Here we describe the transition and progress in hepatic surgery.

Carcinoma, Hepatocellular↗
PubMed2000

C(2)-Symmetric bis-sulfoxide: A novel chiral auxiliary for asymmetric desymmetrization of cyclic meso-1,2-diols

A new heterocyclic compound, C(2)-symmetric bis-sulfoxide 1, has been found to be an efficient chiral auxiliary for asymmetric desymmetrization of cyclic meso-1,2-diols via diastereoselective acetal fission. Both (R,R)- and (S,S)-1 are readily synthesized with high optical purity via asymmetric oxidation of 1, 5-benzodithiepan-3-one (2). After acetalization of meso-1,2-diols 6a-e and a mono-TMS ether 6f with this chiral auxiliary 1, the resulting acetals 7a-f were subjected to base-promoted acetal fission upon treatment with potassium hexamethyldisilazide (KHMDS) followed by acetylation or benzylation to give the desymmetrized diol derivatives 8a-f with high diastereoselectivity. The chiral auxiliary 1 is readily removed by acid-promoted hydrolysis and can be recovered without a loss in enantiomeric excess.

Journal Article↗
PubMed2000

Clinical evaluation of 99mTc-Technegas SPECT in thoracoscopic lung volume reduction surgery in patients with pulmonary emphysema.

UNLABELLED: 99mTc-Technegas (Tcgas) SPECT is useful for evaluating the patency of the airway and highly sensitive in detecting regional pulmonary function in pulmonary emphysema. The aim of this study is to evaluate regional ventilation impairment by this method pre and post thoracoscopic lung volume reduction surgery (LVRS) in patients with pulmonary emphysema. METHODS: There were 11 patients with pulmonary emphysema. The mean age of patients was 64.1 years. All patients were males. LVRS was performed bilaterally in 8 patients and unilaterally in 3 patients. Post inhalation of Tcgas in the sitting position, the subjects were placed in the supine position and SPECT was performed. Distribution of Tcgas on axial images was classified into 4 types, A: homogeneous, B: inhomogeneous, C: hot spot, D: defect. Three slices of axial SPECT images, the upper, middle and lower fields were selected, and changes in deposition patterns post LVRS were scored (Tcgas score). RESULTS: Post LVRS, dyspnea on exertion and pulmonary function tests were improved. Pre LVRS, inhomogeneous distribution, hot spots and defects were observed in all patients. Post LVRS, improvement in distribution was obtained not only in the surgical field and other fields, but also in the contralateral lung of unilaterally operated patients. In 5 patients some fields showed deterioration. The Tcgas score correlated with improvements in FEV1.0, FEV1.0% and %FEV1.0. CONCLUSION: Tcgas SPECT is useful for evaluating changes in regional pulmonary function post LVRS.

Aged↗
PubMed2000

Augmented prostaglandin E2 generation resulting from increased activities of cytosolic and secretory phospholipase A2 and induction of cyclooxygenase-2 in interleukin-1 beta-stimulated rat calvarial cells during the mineralizing phase.

OBJECTIVE AND DESIGN: To assess prostaglandin (PG) E2 production by osteoblasts during the mineralizing phase after interleukin (IL)-1beta stimulation, using an in vitro system of rat calvarial cells cultured for 21 days. METHODS: The cells, which reached confluence after 3 days, were designated day 0 cells. Culture was continued for a further 21 days after confluence. The cells on the 21st day of the culture were designated day 21 cells. RESULTS: The PGE2 concentration in the medium of the day 21 cells was increased 72 h after IL-1beta treatment, and reached a peak level approximately 1,400 times that of the day 0 cells 6 h after IL-1beta treatment. We examined the effects of IL-1beta on PGE2 production and changes in the relevant enzyme activities, and found that the activities of cytosolic phospholipase A2 (cPLA2), type II secretory PLA2 (sPLA2) and cyclooxygenase (COX)-2 in the day 21 cells were increased. Both selective COX-2 inhibitor and cPLA2 inhibitor abolished PGE2 generation, whereas an sPLA2 inhibitor partially inhibited it. Taken together, these results indicate that COX-2 and cPLA2 play pivotal roles and sPLA2 is involved in IL-1beta-stimulated PGE2 production by these cells. Furthermore, we found that IL-Ibeta treatment induced PGE synthase activity and this correlated well with PGE2 production. CONCLUSION: Augmented PGE2 production by mineralizing osteoblasts after IL-1beta treatment, and the involvement of IL-1beta-induced cPLA2, sPLA2, COX-2 and PGE synthase activities in this phenomenon were demonstrated.

Animals↗
PubMed2000

Gallyas-positive argyrophilic and ubiquitinated filamentous inclusions in rapidly progressive motor neuron disease: immunohistochemical and electron microscopic studies.

In an autopsy case of sporadic rapidly progressive lower motor neuron disease (MND), Gallyas-positive argyrophilic and ubiquitinated filamentous intracytoplasmic inclusions were found in the neurons. Clinically, 7 months prior to death, a 68-year-old woman experienced a history of rapidly progressive muscle weakness of all four extremities and bulbar sign, without sensory and autonomic disturbance. Two months later, she became unable to stand or walk. Four months after onset, she needed respiratory support, and subsequently died due to cardiorespiratory arrest. Neuropathological examinations revealed neuronal loss and associated gliosis in the lower motor neurons, except for ocular motor nuclei, Clark's column, and accessory cuneate nucleus, and tract degeneration was observed in the middle root zone of the posterior column and spinocerebellar tract. No Bunina bodies or Lewy body-like hyaline inclusions were found in the anterior horns. Gallyaspositive argyrophilic filamentous inclusions were found in the lower motor neurons and in nerve cells of the Clark's column, intermediate zone, posterior horn and accessory cuneate nucleus. These were positive with anti-ubiquitin antibody but negative with anti-tau (tau-2 and AT8) and neurofilament antibodies. Electron microscopic examinations disclosed randomly arranged tubular-like filamentous profiles, with a diameter of 12-14 nm, sometimes with amorphous granules in the perikaryon. This is the first report on the Gallyas-positive argyrophilic and ubiquitinated filamentous inclusions in neurons in MND.

Aged↗