Search PubMed⌕ Search

Biomedical subjects

S Ishihara

Publications and source records attributed to S Ishihara.

At least 73 records · Page 4Linked to original sources
PubMed2001

Two cases of severe bronchopneumonia due to influenza A (H3N2) virus: detection of influenza virus gene using reverse transcription polymerase chain reaction.

We report two cases of severe bronchopneumonia due to influenza A (H3N2) virus. The severity of the disease necessitated initiation of empiric therapy based on the present illness and clinical data on admission. Both patients were improved by artificial ventilation with positive end-expiratory pressures and administration of broad spectrum antibiotics and corticosteroids before confirming the diagnosis of viral bronchopneumonia using viral culture and serological tests. Within 24 hours, influenza A (H3N2) virus was identified by amplification of the pathogen genes by reverse transcription polymerase chain reaction (RT-PCR) using the stored bronchoalveolar lavage (BAL) fluids of both cases. This suggests that a combination of detection methods of pathogens using RT-PCR and BAL fluid will facilitate determination of rational treatment aimed at influenza A virus.

Aged↗
PubMed2001

Peduncular hallucinosis due to a pineal meningioma. Case report.

The authors report the case of a 53-year-old woman who experienced visual hallucinations diagnosed as peduncular hallucinosis (PH). The cause of the PH was compression of the quadrigeminal plate and/or the splenium due to a meningioma originating from the falcotentorial junction (pineal meningioma). The nature of the visual hallucinations was depicted in drawings created by the patient herself. This is the first report of PH caused by a tumor located in the pineal region.

Female↗
PubMed2001

[Tiny aneurysms of cortical arteries presenting as an acute subdural hematoma: a case report].

A case of an acute subdural hematoma due to the rupture of a tiny aneurysm of a cortical artery is described. A 68-year-old man lightly hit the right side of his head. About 1 hour later, he became drowsy and exhibited moderate hemiparesis on the left side on admission. Computed tomographic scanning demonstrated an acute subdural hematoma on the right temporoparietal region. In the past, he had undergone the clipping of a non-ruptured aneurysm and a subdural-peritoneal shunt operation on the same side in another hospital. On surgical evacuation of the subdural hematoma, a pulsating bleeding from a ruptured tiny aneurysm of a cortical artery was observed. There were also some similar tiny aneurysms on other cortical arteries. A photograph of such a tiny aneurysm was first taken and presented.

Aged↗
PubMed2001

[Case report of a malfunctioning SJM 19 A aortic valve prosthesis requiring reoperation].

The patient was a 56-year-old female diagnosed with poor lung function who had undergone an aortic valve replacement 10 years ago, receiving an SJM 19 A prosthetic valve. She suffered from dyspnea and chest pain with postural change. Her anticoagulation level was maintained therapeutic. A cinefluoroscopy showed that one of the leaflets in the prosthetic valve was not moving. The aortic peak pressure gradient was calculated to be 68 mmHg using Doppler echocardiography. The patient's clinical condition improved after thrombolytic therapy with urokinase, but a complete normalization of her prosthetic discs was not obtained, so the patient was treated surgically. After an aortotomy, a pannus formation covering the entire SJM 19 A valve was observed. The aortic annulus was estimated to be 16 mm in diameter after the excision of the SJM 19 A valve and required before a larger prosthesis could be inserted. A SJM 19 HP valve was then anchored to the enlarged annulus. Her postoperative course was uneventful. We report a case requiring reoperation after a small aortic mechanical valve prosthesis implanted 10 years previously was damaged by thrombosis and pannus. Pannus formation on small aortic prosthesis easily caused hemodynamic obstructions and mechanical failure. Intensive evaluation with Doppler echocardiography and cinefluoroscopy is required for such patients.

Aortic Valve↗
PubMed2000

Identification of novel first exons in Ad4BP/SF-1 (NR5A1) gene and their tissue- and species-specific usage.

It has been demonstrated that the mammalian Ad4BP/SF-1 (NR5A1) gene is regulated precisely in sex, tissue, and developmental stage specific manners. To clarify the complex transcriptional regulation, we investigated in the present study whether the gene transcription is regulated by multiple promoters accompanied by noncoding first exons. Novel first exons (Io and Ig) were identified downstream of the already identified exon Ia. Nucleotide sequences revealed that Ia and Ig exons were well conserved, whereas Io exon was less conserved among the mouse, rat, and human genes. Interestingly, the splice donor of the mouse and human Io and human Ig exons do not satisfy the consensus sequence. Transcripts containing Ia, Io, and Ig were detected in all rat tissues examined, while the transcript containing Io was undetectable in the corresponding tissues of mice. The lack of exon Io usage in the mouse was confirmed by transient transfection assays with cultured cells. Quantitative RT-PCR analysis revealed that the transcript containing Ig exon was the main product in the pituitary but significantly less in the spleen, suggesting that the regulation of Ad4BP/SF-1 gene transcription in the pituitary and spleen is distinct from that of other tissues. The above findings, together with the structural abnormality at the splice donor site, suggest that acquisition of the multiple first exons enables the Ad4BP/SF-1 gene to be regulated differentially in different animal species and in different tissues in the same animal.

Alternative Splicing↗
PubMed2000

Regulation of Lef-mediated transcription and p53-dependent pathway by associating beta-catenin with CBP/p300.

CBP and its homologue p300 play significant roles in cell differentiation, cell cycle, and anti-oncogenesis. We demonstrated that beta-catenin, recently known as a potent oncogene, and CBP/p300 are associated through its CH3 region, which is a primary target of adenoviral oncoprotein E1A and various nuclear proteins, such as p53, cyclin E, and AP-1, and both are colocalized in the nuclear bodies. CBP/p300 potentiated Lef-mediated transactivation of beta-catenin, and E1A, a potent inhibitor of CBP/p300, repressed its transactivation. Furthermore, overexpression of stable beta-catenin mutant competitively suppressed the p53-dependent pathway. These may be a key mechanism of beta-catenin involved in oncogenic events underlying disruption of tumor suppressor function through CBP/p300.

Apoptosis↗
PubMed2000

Posttranscriptional regulation of alpha-catenin expression is required for Wnt signaling in L cells.

alpha-Catenin is an essential component of the cadherin-catenin cell-cell adhesion complex. An excess amount of alpha-catenin also affects the Wnt signaling pathway probably through its direct binding to beta-catenin. Here, we examined the molecular mechanisms of the posttranscriptional regulation of alpha-catenin expression. We constructed an expression vector with alpha-catenin cDNA lacking the 5'-untranslated sequence. In L cell transfectants stably expressing mRNA derived from this vector, the amount of exogenous alpha-catenin protein was about 10-fold higher than that of the endogenous protein. The expression level of the exogenously expressed alpha-catenin mRNA, however, was about 80% of that of endogenous molecule. Most of the endogenous and exogenous alpha-catenin protein in cadherin-negative cells was degraded 5 h after inhibition of protein synthesis. Although alpha-catenin contains the PEST sequence, various proteasome and calpain inhibitors did not affect the level of expression of endogenous alpha-catenin protein in L cells. Overexpressed alpha-catenin showed cytoplasmic localization, disturbed the nuclear localization of stabilized beta-catenin, and inhibited TCF-4-responsive transactivation after Wnt-3a treatment. These results suggested that the low-efficiency of translation and unidentified degradation mechanisms maintained the low levels of alpha-catenin expression in the cytoplasm as a necessary condition for the Wnt signaling pathway.

5' Untranslated Regions↗
PubMed2000

Alpha-glycosylceramides enhance the antitumor cytotoxicity of hepatic lymphocytes obtained from cancer patients by activating CD3-CD56+ NK cells in vitro.

Alpha-glycosylceramides, such as alpha-galactosylceramide and alpha-glucosylceramide, induce antitumor immunity in various murine cancer models. In the murine hepatic metastasis model, V alpha 14 TCR+NK1.1+ T cells, which accumulate preferentially in the liver, are considered to play a key role in the induction of antitumor immunity by alpha-glycosylceramides. We recently reported that V alpha 24 TCR+ NKT cells, the human homologues of murine V alpha 14 TCR+NK1.1+ cells, are rarely seen among freshly isolated human hepatic lymphocytes. Therefore, it is important to examine whether alpha-glycosylceramides also enhance the antitumor cytotoxicity of human hepatic lymphocytes, as they have been shown to do in murine systems, to determine the usefulness of alpha-glycosylceramides in cancer immunotherapy in humans. Here, we show that alpha-glycosylceramides greatly enhance the cytotoxicity of human hepatic lymphocytes obtained from cancer patients against the tumor cell lines, K562 and Colo201, in vitro. The direct effector cells of the elicited cytotoxicity were CD3-CD56+ NK cells. Even though V alpha 24 TCR+NKT cells proliferated remarkably in response to alpha-glycosylceramides, they did not contribute directly to the cytotoxicity. Our observations strongly suggest the potential usefulness of alpha-glycosylceramides for immunotherapy of liver cancer in humans based on their ability to activate CD3-CD56+ NK cells in the liver.

Adjuvants, Immunologic↗
PubMed2000

Genetic defect in human X-linked agammaglobulinemia impedes a maturational evolution of pro-B cells into a later stage of pre-B cells in the B-cell differentiation pathway.

Surrogate light chains (lambda 5/VpreB) are selectively expressed in early precursors of B cells. B-cell defects in X-linked agammaglobulinemia (XLA) are caused by mutations in the gene for Bruton's tyrosine kinase. To elucidate the nature of early B-lineage cells in bone marrow (BM), samples from 13 XLA patients and 24 healthy controls of different ages were comparatively analyzed using an antihuman VpreB monoclonal antibody. Expression of surrogate light (SL) and mu-heavy chains were examined after cell membrane permeabilization because they are mainly expressed in the cytoplasm of early B-lineage cells. A flow cytometric analysis of normal BM identified 5 discrete cell types of B cells: mu(-)SL(++) (pro-B [B-cell progenitor]), mu(low)SL(++) (pre-B1a), mu(low)SL(+) (pre-B1b), mu(low)SL(- )(pre-B2), and mu(high)SL(- )(B). The large cells, presumably in cycling states, were enriched in pre-B1a cells. The frequencies of B-lineage cells in BM were higher in young children, and declined with advancing age. In contrast, XLA showed a profound reduction in BM B-lineage cells. In XLA BM, an expansion of pro-B cells with some small pre-B1a cells was marked, but other cells were negligible. These observations illustrate a B-cell maturation defect in XLA as well as a normal human B-cell differentiation pathway. The results suggest that the genetic defect in XLA may impede the evolution of pro-B cells beyond the earlier pre-B stage into the later stage of pre-B cells in B-cell development. (Blood. 2000;96:610-617)

Adolescent↗
PubMed2000

Successful surgical treatment for spontaneous retroperitoneal hematoma in polycythemia vera: report of a case.

Bleeding is a common complication of such myeloproliferative disorders as polycythemia vera, and it usually occurs in either the skin or mucosa. We experienced a case of a massive retroperitoneal hematoma with no history of trauma in association with polycythemia vera. A 68-year-old man was referred to our hospital as a case of acute abdomen, and was diagnosed as having a retroperitoneal hematoma and polycythemia vera based on radiological and hematological examinations. Because the mass effect of the hematoma caused a progressive deterioration of his respiratory condition, surgical drainage was necessitated and successfully undertaken. Although conservative treatment is reportedly sufficient and uncontrollable intraoperative bleeding may occur, especially in cases of myeloproliferative disorders, our experience suggests that an operation may nevertheless be occasionally advisable for this rare condition.

Aged↗
PubMed2000

Development of a rapid assay for screening point mutations associated with quinolone resistance in the Pseudomonas aeruginosa parC gene.

To detect quinolone resistance-associated mutations within the Ser-80 and Glu-84 codons of the Pseudomonas aeruginosa parC gene, we developed a rapid and simple assay based on polymerase chain reaction (PCR) amplification of the region of the parC gene containing the mutation sites and digestion of the PCR products with a restriction enzyme. The mutations generating alterations at Ser-80 and Glu-84 were detected as restriction fragment length polymorphisms of the PCR products digested with HinfI. Among 22 clinical isolates tested by this assay, mutations at the Ser-80 and Glu-84 codons were detected in all 10 isolates in which the presence of the mutations had been confirmed previously by DNA sequencing. This rapid and simple assay could be a useful screening device for genetic alterations associated with resistance to quinolones in the P. aeruginosa parC gene.

4-Quinolones↗
PubMed2000

Cystic schwannoma of the orbit: case report.

BACKGROUND: Cystic lesions of the orbit have diverse clinical findings and histopathological features. We report an orbital schwannoma composed of a single cyst. CASE DESCRIPTION: A 62-year-old woman with an intraconal cystic tumor in the left orbital cavity is described. The cystic tumor was totally removed and the pathological diagnosis of the cyst wall was schwannoma composed of both Antoni type A and B. CONCLUSIONS: A rare case of cystic schwannoma of the orbit is reported. This case may contribute to an improved preoperative differential diagnosis for cystic lesions of the orbit.

Cysts↗
PubMed2000

Cerebellar neuroblastoma in an infant.

A cerebellar neoplasm in an 8-month-old boy is reported. While this tumour was composed of small cells and had regions resembling desmoplastic medulloblastoma, it showed ultrastructural neuronal characteristics including bundles of microtubules in the cell processes, numerous synaptic vesicles, and occasional abortive or complete synapses. These characteristic features warranted the diagnosis of a neuroblastoma of the cerebellum. The nature of this rare intraparenchymal tumour in infants is also briefly discussed.

Cerebellar Neoplasms↗
PubMed2000

On fatigue lifetimes and fatigue crack growth behavior of bone cement.

Bone cement is used to develop a mechanical bond between an artificial joint and the adjacent bone tissue, and any degradation of this bond is of serious concern since it can lead to loosening and eventually malfunction of the artificial joint. In the present study, the fatigue lives and fatigue crack propagation behavior of two bone cements, CMW Type 3 and Zimmer, were investigated, and it was found that the size and distribution of pores played a major role in influencing both the fatigue crack initiation and propagation processes. The fatigue lifetimes of CMW exceeded those of Zimmer because of a lesser density of large pores. When the fatigue lifetimes were plotted as a function of Klimax, the maximum initial stress intensity factor based upon the initiating pore size, the difference in fatigue lifetimes between CMW and Zimmer bone cements was greatly reduced. The fatigue crack growth behavior of both bone cements were similar. This is a further indication that the noted differences in fatigue lifetimes were related to the size of the pore at the crack initiating site.

Journal Article↗
PubMed2000

Diagnostic accuracy of a new non-invasive enzyme immunoassay for detecting Helicobacter pylori in stools after eradication therapy.

BACKGROUND: Helicobacter pylori eradication therapy has been commonly performed for patients with peptic ulcer. An inexpensive, reliable, non-invasive test would be useful for evaluation of the effectiveness of eradication therapy. AIM: To evaluate the diagnostic potential of a new non-invasive enzyme immunoassay (HpSA) for H. pylori antigen in stools. METHODS: A total of 112 peptic ulcer patients with H. pylori infection (82 male, 30 female; age range 22-81 years, mean 54 years) received a course of eradication therapy. Four weeks after the end of the therapy, stool samples were collected from all patients and tested using the HpSA. The diagnostic accuracy of the HpSA EIA was evaluated in comparison with the results of a 13C-urea breath test. RESULTS: The diagnostic sensitivity of HpSA EIA after eradication therapy was 90%, the specificity 98%, the positive predictive value 82% and the negative predictive value 99%. CONCLUSION: The HpSA stool test is potentially useful for the diagnosis of H. pylori infection 4 weeks after the end of eradication therapy.

Adult↗
PubMed2000

Efficacy of sucralfate for Helicobacter pylori eradication triple therapy in comparison with a lansoprazole-based regimen.

BACKGROUND: Sucralfate has an inhibitory action against Helicobacter pylori and enhances the anti-H. pylori activity of antimicrobials. AIM: To evaluate the efficacy and safety of sucralfate-based eradication therapy for H. pylori infection, compared with that based on lansoprazole, in a randomized multicentre study. SUBJECTS AND METHODS: The subjects were 150 H. pylori-positive patients. They were randomly assigned to one of two regimens for 2 weeks: sucralfate 1 g t.d.s., amoxycillin 500 mg t.d.s., and clarithromycin 400 mg b.d. (SAC regimen: 75 patients); or lansoprazole 30 mg o.m. with the same antimicrobial medications (LAC regimen: 75 patients). Cure of infection was assessed by a 13C urea breath test 1 month after completion of treatment. RESULTS: Eight patients (four in the SAC group and four in LAC group) could not continue therapy because of severe diarrhoea, and three did not take the 13C urea breath test after therapy. Cure rates for intention-to-treat, all-patients-treated, and per protocol analysis in the SAC group were 80%, 83%, and 88%, respectively, and those in the LAC group were 87%, 87%, and 92%, respectively. There were no significant differences in cure rate or adverse effects between the two regimens. CONCLUSION: Sucralfate in combination with amoxycillin and clarithromycin is as effective as lansoprazole-based eradication therapy for H. pylori.

2-Pyridinylmethylsulfinylbenzimidazoles↗