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Biomedical subjects

M Ohno

Publications and source records attributed to M Ohno.

At least 73 records · Page 4Linked to original sources

Inverse expression of Cdk4 and p16 in epithelial ovarian tumors.

OBJECTIVES: The aim of this study was to elucidate the expression and the correlation of two cell cycle regulators, cdk4 and its inhibitor p16, in a series of benign, borderline, and malignant ovarian tumors and to evaluate whether their alterations correlate with clinicopathologial parameters and patients' prognosis in epithelial ovarian carcinomas. METHODS: Immunohistochemical analysis using anti-cdk4 and anti-p16 antibodies was carried out for 103 paraffin sections of ovarian tumors, and Western blot analysis and cdk4 activity assay were performed in 26 fresh ovarian tumor samples. RESULTS: The results of immunohistochemistry showed that 60.61 and 69.70% of benign, 69.57 and 56.52% of borderline, and 74.47 and 40. 43% of malignant tumors expressed cdk4 and p16, respectively, demonstrating increased cdk4 and decreased p16 expression in ovarian carcinomas. A significant inverse relationship between cdk4 and p16 expression was found. The loss of p16 expression was more correlated with G(2) and G(3) tumors in contrast with G(1) tumors. No significant correlation was observed between cdk4 expression and clinicopathological parameters. Neither cdk4 nor p16 expression has significant effects on overall survival by the Kaplan-Meier method. When the combined phenotypes of the two proteins were analyzed, patients with cdk4-positive/p16-negative expression had a reduced overall survival than other phenotypes of cdk4/p16. CONCLUSIONS: These data suggest that inverse expression of cdk4 and p16 may be involved in the development and progression of epithelial ovarian carcinomas. The combined phenotypes of cdk4 and p16 proteins could provide a useful prognostic indicator for patients with epithelial ovarian carcinoma.

Adenocarcinoma↗

Benign schwannoma of the esophagus removed by enucleation: report of a case.

A submucosal tumor of the esophagus was enucleated by a thoracotomy. A microscopic examination showed the tumor to be composed of spindle-shaped cells showing mild nuclear atypia with vague nuclear palisading and scarce mitotic figures. The tumor was surrounded by peripheral lymphoid cuffs. An immunohistochemical study demonstrated diffuse positive staining for S-100 protein in the tumor cells. The lesion was diagnosed to be an esophageal schwannoma based on these pathological features. Benign schwannoma of the esophagus has been described in five cases in four reports in the English literature. This is the sixth case diagnosed by immunohistochemical studies.

Esophageal Neoplasms↗

Heterotopia in microcephaly induced by cytosine arabinoside: hippocampus in the neocortex.

Pregnant mice were injected intraperitoneally with cytosine arabinoside (Ara-C) on days 13.5 and 14.5 of pregnancy. The brains of their offspring were studied histologically and histochemically. In addition to dysgenic microcephaly, nodular structures consisting of cells with a relatively homogeneous morphology were observed in the depths of the cerebral cortex. The cell clusters were first seen around postnatal day 4, and had a cellular continuity with the disarrayed pyramidal cell layer in the CA 1 region of the hippocampus. Golgi-Cox staining showed a number of pyramidal-shaped cells in the clusters. Morphologically, they resembled the pyramidal neurons of the hippocampus. Immunohistochemical examination, using anti-serotonin or anti-tyrosine hydroxylase antibodies, also indicated similarities between the cell clusters and the pyramidal cell layer. It is, therefore, proposed that the cell clusters consisted of heterotopic pyramidal cells of the hippocampus. A few synaptic structures could already be detected in the heterotopic cell clusters on postnatal day 3 by electron microscopy. This early establishment of synaptic contact with related neurons may have caused the heterotopic localization of the pyramidal cells.

Abnormalities, Drug-Induced↗

Appendiceal intussusception induced by tubulovillous adenoma with carcinoma in situ: report of a case.

Appendiceal intussusception is an uncommon pathologic condition; however, villous adenoma of the appendix is a distinctly rare entity. We report herein a case of appendiceal intussusception induced by tubulovillous adenoma with carcinoma in situ. A 67-year-old man was admitted to our hospital with a 1-year history of lower abdominal pain for investigation. Barium enema showed a filling defect with an irregular surface in the cecum, and colonoscopy revealed a cecal tumor with a granular surface. Pathological examination of biopsy samples revealed tubulovillous adenoma with well-differentiated adenocarcinoma, and a diagnosis of cecal cancer in tubulovillous adenoma was made. Surgery was performed and the resected specimen was found to contain a tumor arising from the appendix. The tumor was 5.5 x 4.5 cm in size in the cecal cavity, and the appendix had invaginated into the cecum at its base. The cut surface of the appendix showed the villous tumor filling the appendiceal lumen and projecting into the cecal cavity. Microscopic examination revealed well-differentiated adenocarcinoma in tubulovillous adenoma. To the best of our knowledge, this is the first report of appendiceal intussusception caused by tubulovillous adenoma with carcinoma of the appendix.

Adenocarcinoma↗

Cholinergic and glutamatergic activation reverses working memory failure by hippocampal histamine H1 receptor blockade in rats.

Intrahippocampal administration of the histamine H1 receptor antagonist pyrilamine (3.2-32 ug/ side) but not the histamine H2 receptor antagonist cimetidine (1.0-10 microg/side) increased the number of errors in the working memory task with a three-panel runway setup. The increase in working memory errors induced by intrahippocampal 32 microg/side pyrilamine was significantly reduced by concurrent infusion of the histamine H1 receptor agonist 2-pyridylethylamine (3.2 and 10 microg/side). The cholinesterase inhibitor physostigmine ( 1.0 and 3.2 microg/side) and D-cycloserine (0.32 and 1.0 microg/side), the partial agonist at the glycine binding site on the NMDA receptor/channel complex, reduced the increase in working memory errors induced by intrahippocampal 32 microg/side pyrilamine. These results suggest that the hippocampal histaminergic activity via histamine H1 receptor is necessary for normal working memory processes and that the septohippocampal cholinergic activation and positive modulation of the NMDA receptor/channel through activation of the glycine site can alleviate dysfunction of hippocampal histamine H1 receptor-mediated neurotransmission involved in working memory function.

Acetylcholine↗

Regional and accelerated molecular evolution in group I snake venom gland phospholipase A2 isozymes.

In accordance with detection of a few phospholipase A2 (PLA2) isozyme genes by Southern blot analysis, only two cDNAs, named NnkPLA-I , and NnkPLA-II, encoding group I PLA2s, NnkPLA-I and NnkPLA-II, respectively, were isolated from the venom gland cDNA library of Elapinae Naja naja kaouthia of Malaysia. NnkPLA-I and NnkPLA-II showed four amino acid substitutions, all of which were brought about by single nucleotide substitution. No existence of clones encoding CM-II and CM-III, PLA2 isozymes which had been isolated from the venom of N. naja kaouthia of Thailand, in Malaysian N. naja kaouthia venom gland cDNA library was verified by dot blot hybridization analysis with particular probes. NnkPLA-I and NnkPLA-II differed from CM-II and CM-III with four and two amino acid substitutions, respectively, suggesting that their molecular evolution is regional. The comparison of NnkPLA-I, NnkPLA-II and cDNAs encoding other group I snake venom gland PLA2s indicated that the 5'- and 3'-untranslated regions are more conserved than the mature protein-coding region and that the number of nucleotide substitutions per nonsynonymous site is almost equal to that per synonymous site in the protein-coding region, suggesting that accelerated evolution has occurred in group I venom gland PLA2s possibly to acquire new physiological functions.

Amino Acid Sequence↗

A putative chemoattractant receptor, C5L2, is expressed in granulocyte and immature dendritic cells, but not in mature dendritic cells.

Leukocyte chemoattractants are involved in the inflammatory response act via G protein-coupled receptors. We report the cloning of a novel human gene encoding the putative orphan receptor, C5L2, belonging to a subfamily of C3a, C5a and formyl Met-Leu-Ph receptors that are related to the chemokine receptor family. C5L2 transcript levels were abundant in granulocytes and immature dendritic cells but not in mature dendritic cells. We speculate that this receptor may regulate the activation of immature dendritic cells and play a role in the chemoattraction of leukocytes to inflammatory regions.

Amino Acid Sequence↗

Zonisamide treatment of early infantile epileptic encephalopathy.

A case of early infantile epileptic encephalopathy with suppression-bursts (EIEE or Ohtahara syndrome) with an excellent response to zonisamide is reported. Tonic spasms began immediately after birth and increased in number, such that they formed a series of several dozen spasms lasting for 5 to 15 minutes. When the patient was 1 month old, a partial clonic seizure emerged predominantly on the right side of her face and extremities. It was often followed by tonic spasms and later continued after the beginning of the spasm series. Interictal electroencephalography demonstrated an atypical suppression-burst pattern and focal paroxysmal discharges. Detailed hematologic tests, magnetic resonance imaging, single-photon emission computed tomography, and auditory brainstem response did not reveal any metabolic or structural abnormalities. Oral administration of zonisamide first controlled the partial seizures and, subsequently, the tonic spasms in a dose-dependent fashion. The mode of response to zonisamide and the findings on electroencephalography indicate that EIEE may be caused by multiple independent brain lesions and that EIEE is a heterogeneous disorder. It is suggested that zonisamide may be useful in the treatment of EIEE.

Anticonvulsants↗

Changes in diffusion-weighted MRI after status epilepticus.

A 3-year-old male developed hemiplegia and aphasia after convulsive status epilepticus. Diffusion-weighted magnetic resonance images demonstrated cytotoxic edema in the white matter 6 days after the seizure episode and subsequently in the gray matter after an additional 7 days. Diffusion-weighted magnetic resonance images demonstrated a subacute evolution of the pathologic process after the status epilepticus.

Brain Edema↗

T-0162, a novel free radical scavenger, reduces myocardial infarct size in rabbits.

1. We investigated the effects of 1-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-3-(3-pyridylmethyl)urea hydrochloride (T-0162), a novel low-molecular weight free radical scavenger, on the generation of superoxide anions and hydroxyl radicals in vitro and in vivo and on myocardial infarct (MI) size in an in vivo model of MI in rabbits. 2. It was found that T-0162 scavenged both superoxide anions and hydroxyl radicals in a concentration-dependent manner in vitro. 3. In an in vivo rabbit model with 30 min coronary occlusion and 30min reperfusion, T-0162 scavenged hydroxyl radicals generated in the myocardium during reperfusion. 4. Anaesthetized open-chest Japanese white male rabbits were subjected to 30 min coronary occlusion and 48 h reperfusion. The control group (n = 10) was infused with 10% lecithin solution for 220 min from 10 min before occlusion to 180 min after reperfusion. The pretreatment group (n = 10) was infused with T-0162 dissolved in 10% lecithin solution for 220 min from 10 min before occlusion to 180 min after reperfusion at a rate of 400 microg/kg per min. The post-treatment group (n = 10) was injected with an i.v. bolus of 10 mg/kg T-0162 and was then infused with 400 microg/kg per min T-0162 for 190 min from 10 min before reperfusion to 180 min after reperfusion. After 48 h reperfusion, infarct size was measured histologically and expressed as a percentage of area at risk (AAR). 5. There was no significant difference in haemodynamic parameters among the three groups throughout the experimental period. The per cent infarct size of the AAR in the T-0162 groups (24.8+/-4.3 and 30.5+/-3.9% for pre- and posttreatment groups, respectively) was significantly reduced compared with control (44.7+/-4.1%; P<0.05). There was no significant difference in the AAR among the three groups. 6. In conclusion, T-0162 reduces MI size through the inhibition of reperfusion injury.

Animals↗

Chromosome analysis of human spermatozoa from an oligoasthenozoospermic carrier for a 13;14 Robertsonian translocation by their injection into mouse oocytes.

We present a case of a 46,XY der(13;14) Robertsonian translocation carrier whose spermatozoa were karyotyped after injection into mouse oocytes. Fresh semen samples as well as recovered samples were used. There was no significant difference in the survival rate of mouse oocytes (fresh: 78.1% versus frozen: 81.7%), activation rate (fresh: 84.0% versus frozen: 90.6%), fertilization rate (fresh: 72.0% versus thawing of frozen: 76.5%) between fresh or frozen spermatozoa. Metaphase chromosome spreads from 45 spermatozoa were analysed. The frequency of spermatozoa that were chromosomally unbalanced with respect to the translocation was 8.9%, and the frequency of abnormalities unrelated to translocation was 4.4%. An excess of spermatozoa with balanced chromosomes was observed: compared with normal, 23 (51.1%) versus 16 (35.6%) respectively; but this segregation difference was not statistically significant (chi(2) = 0.9, P > 0.3). After genetic counselling with the carrier and his partner, intracytoplasmic sperm injection treatment was performed. Healthy female and male infants were delivered at 36 weeks gestation via a Caesarean section. Both babies were carriers for the balanced Robertsonian translocations detected for prenatal diagnosis at 16 weeks gestation. The present study demonstrates that patients can be given further information about the proportion of the spermatozoa which carry a chromosomal abnormality.

Adult↗

Isolation and characterization of pepsinogen from Trimeresurus flavoviridis (Habu snake).

Pepsinogen was isolated from the gastric mucosa of Trimeresurus flavoviridis (Habu snake) by DEAE-cellulose and DEAE-Sepharose ion-exchange chromatographies, and Sephacryl S-200 gel-chromatography. The yield calculated from the crude extract was 29% with 6.2-fold purification. The purified pepsinogen gave a single band on both native- and SDS-PAGE. As no other active enzyme was detected on the chromatographies, it was concluded that the Habu snake has one major pepsinogen. The molecular mass of the pepsinogen was estimated to be 38 kDa by SDS-PAGE. The sequence of the N-terminal 26 amino acid residues was determined and compared with those of other pepsinogens. The N-terminal structure of Habu snake pepsinogen was more homologous with those of mammalian pepsinogens C than those of mammalian pepsinogens A. The pepsinogen was rapidly converted to pepsin by way of an intermediate form induced by acidification. The optimum pH of Habu snake pepsin for bovine hemoglobin was 1.5-2.0, and it retained full activity at pH 6.2 and 30 degrees C on incubation for 30 min. The optimum temperature for the snake pepsin was 50 degrees C and it was stable at 40 degrees C on incubation for 10 min. The proteolytic activity of the pepsin toward bovine hemoglobin was about two times higher than that of porcine pepsin A, however, the activity toward oxidized bovine insulin B-chain was lower than that of porcine pepsin A, and it did not hydrolyze oligopeptides. The specificity for oxidized bovine insulin B-chain of the pepsin was different from that of porcine pepsin A. Habu snake pepsin was inhibited by pepstatin A but not by serine, cysteine, or metallo protease inhibitors.

Amino Acid Sequence↗

EmPLiCS: an empirical approach for structure-based design of natural peptide drugs.

The computer implementation of a peptide drug-design strategy has been developed. The system is named EmPLiCS (Empirical Peptide Ligand Construction System) according to the strategy of the system, which searches for peptide-ligand structures by referring to empirical rules that are derived from known protein 3D structures. The system was tested on several known peptide-protein complexes. The results demonstrated the ability of this system to detect key residues of peptides that are crucial for interaction with their specific proteins. The system also showed the ability to detect the main chain trace of these peptides. Some of the main chain atoms were detected even though the complete primary structures were not reproduced, suggesting that main chain structure is important in peptide-protein recognition. The results of the present study demonstrated that the empirical rules-based system can generate significant information for use in the design of natural peptide drugs.

Algorithms↗

Symbiobacterium thermophilum gen. nov., sp. nov., a symbiotic thermophile that depends on co-culture with a Bacillus strain for growth.

A Gram-negative and tryptophanase-positive thermophile, whose growth is dependent on co-culture with an associating Bacillus strain, had been reported and tentatively named Symbiobacterium thermophilum strain T(T). Axenic culture of strain T(T) was recently established by dialysing cultures with the supporting bacterial strains or adding their culture broth. Phylogenetic analysis of strain T(T), based on the 16S rDNA sequence, was conducted for the validation of S. thermophilum. The sequence of strain T(T) was located at the outermost position in the high-G+C Gram-positive group distinctly isolated from any other branches hitherto known. Ten sequences identical to that of strain T(T), and one sequence closely related to it, were identified for the first time from soil and compost samples. The outer membrane of strain T(T) had a three-layered structure, outside the cytoplasmic membrane, which is similar to the S-layer in the cells of members of the Bacillaceae. Chemical analysis of the cells revealed that menaquinone-6 is a major component of the quinone system. According to these results, along with several previous observations (i.e. a G+C DNA content of 65 mol% and the identification of iso-C15:0 and iso-C17:0 acids as major cellular fatty acids), the new taxon Symbiobacterium thermophilum gen. nov., sp. nov. is proposed. The type strain is S. thermophilum strain T(T) (= IAM 14863T).

Bacillus↗

Screening of BRCA1 mutation using immunohistochemical staining with C-terminal and N-terminal antibodies in familial ovarian cancers.

We examined the subcellular localization of BRCA1 proteins using immunohistochemical staining with C-terminal (GLK-2 antibody) and N-terminal (Ab-2 antibody) monoclonal antibodies in 44 familial ovarian cancers. Among these, 24 cases were associated with 13 independent germ-line mutations of BRCA1, and loss of heterozygosity (LOH) at one or more BRCA1 microsatellite markers was found in all 21 informative tumors tested. With GLK-2 antibody, cytoplasmic staining was observed in 15 of 16 tumors (93.8%) with mutation in exon 11, and BRCA1 staining was absent in 8 of 8 tumors (100%) with mutation in exons other than exon 11. When immunohistochemical staining was performed with Ab-2 antibody, both nuclear and cytoplasmic staining were observed in 14 of 16 tumors (87.5%) with mutation in exon 11. Interestingly, nuclear staining was observed in 3 of 3 tumors (100%) with mutation downstream of exon 11, even though no staining was detected in 5 of 5 tumors (100%) with mutation upstream of exon 11. On the other hand, in familial ovarian cancers without BRCA1 mutations, nuclear staining or both nuclear and cytoplasmic staining was observed in 18 of 20 specimens (90%) and 20 of 20 specimens (100%) with GLK-2 antibody and with Ab-2 antibody, respectively. These results suggest that an immunohistochemical assay in combination with employing the C-terminal and the N-terminal antibodies appears to have potential as a reliable and useful technique for the screening of BRCA1 mutations, at least to predict the status of mutation, upstream or downstream of exon 11.

BRCA1 Protein↗

Heme oxygenase-1 is upregulated in the rat heart in response to chronic administration of angiotensin II.

Heme oxygenase (HO) is a heme-catabolizing enzyme that converts heme into biliverdin, iron, and carbon monoxide. HO-1, an inducible form of HO, is thought to act as an endogenous antioxidant defense mechanism. To determine whether chronic administration of angiotensin II affects HO-1 expression in the heart, expression and localization of HO-1 were investigated in the heart of rats receiving angiotensin II infusion (0.7 mg. kg(-1). day(-1)) via osmotic minipump for up to 7 days. Angiotensin II induced formation of granulation tissue, characterized by myofibroblast proliferation, fibrous deposition, and inflammatory cell migration. Angiotensin II also upregulated cardiac HO-1 expression. Immunohistochemistry revealed that HO-1 was intensively expressed in the granulation tissue. The selective AT(1)-receptor antagonist, losartan, completely, but hydralazine only partially, suppressed angiotensin II-induced granulation tissue formation and HO-1 upregulation. Chronic norepinephrine infusion (2.8 mg. kg(-1). day(-1)) did not induce granulation tissue formation or HO-1 upregulation. Our data suggest that angiotensin II upregulates cardiac HO-1 expression in the newly formed inflammatory lesion, which may represent an adaptive response to angiotensin II-induced cardiac damage.

Angiotensin II↗

Apoptosis in microvascular endothelial cells of perfused rabbit lungs with acute hydrostatic edema.

We test the hypothesis that microvascular endothelial cells may undergo apoptosis in response to acute pulmonary venous hypertension. The isolated rabbit lungs were perfused in situ for 4 h with left atrial pressure of 0, 10, or 20 mmHg at a constant blood flow. Edema formation was monitored by lung weight gain. To assay for apoptosis, we performed agarose gel electrophoresis of DNA, in situ nick end labeling of DNA strand breaks, and electron microscopy. We also examined the levels of expression of Bcl-2, a suppressor of apoptosis, in microvascular endothelial cells using an immunohistochemical technique. In a vascular pressure-dependent fashion, we found apoptosis in endothelial cells of alveolar septal capillaries, as well as expression of Bcl-2 in arteriolar and venular endothelial cells. We conclude that acute pulmonary venous hypertension induces apoptosis in capillary endothelial cells but not in arteriolar and venular endothelial cells, suggesting that microvascular endothelial cell apoptosis is dependent on the levels of Bcl-2 expression and influences the formation or resolution of acute hydrostatic lung edema.

Acute Disease↗