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Biomedical subjects

A Yamada

Publications and source records attributed to A Yamada.

At least 235 records · Page 13Linked to original sources
PubMed1997

Immunohistochemical analysis of the nm23 gene products in testicular seminoma.

The nm23 gene has been identified as a metastasis suppressor gene. To clarify the role of nm23 as a metastasis suppressor gene in testicular seminoma, the expression of the nm23-H1 and -H2 proteins (human nucleoside-diphosphate kinase-A and -B) was immunohistochemically examined in 43 patients. Thirty-six (84%) and 21 (49%) of the 43 primary tumors were positive for the nm23-H1 and -H2 proteins, respectively. There was no significant difference in either nm23-H1 or -H2 expression between the 24 primary non-invasive tumors and the 19 primary invasive tumors, or between the 31 primary tumors without metastasis and the 12 primary tumors with metastasis. In all, and 5 of 6 metastatic tumors, the expression of nm23-H1 and -H2 proteins was observed, respectively, and the expression was not decreased in the metastatic tumors, compared to the primary tumors. In conclusion, the immunohistochemical expression of both the nm23-H1 and -H2 gene products is not associated with the metastatic status or the invasive status of testicular seminoma, and it is unlikely to be a useful non-metastatic indicator for testicular seminoma. Further studies are needed to elucidate the biological role of nm23.

Adolescent↗
PubMed1997

Testicular seminoma with human chorionic gonadotropin production.

Testicular seminoma with elevated serum human chorionic gonadotropin level (hCG-positive seminoma) is regarded as more malignant than marker-negative seminoma, although its prognosis is still unclear. To clarify the malignant potential of seminoma with hCG production, the serum levels of the beta subunit of hCG (beta-hCG) and lactic acid dehydrogenase (LDH) were examined in 35 and 40 patients, respectively, and the immunohistochemical expression of beta-hCG examined in 45 tumors. The elevation of the LDH serum level correlated to the invasive status, metastatic status and poor outcome, while that of the serum beta-hCG level correlated only to the metastatic status. Immunohistochemical expression of beta-hCG was observed in syncytiotrophoblastic giant cells in 11 tumors and a few mononuclear seminoma cells in 36 tumors. Expression was not associated with the malignancy potential, except where the expression in mononuclear cells inversely correlated to the invasive status. These results suggest that most seminomas produce a slight amount of hCG; that an elevated hCG serum level indicates the presence of metastatic tumors and mainly reflects an increase in tumor volume but not in cellular malignancy potential; and that the LDH serum level, rather than hCG, is more useful as a prognostic indicator for patients with seminoma.

Adolescent↗
PubMed1997

Identification and characterization of XPC-binding domain of hHR23B.

hHR23B was originally isolated as a component of a protein complex that specifically complements nucleotide excision repair (NER) defects of xeroderma pigmentosum group C cell extracts in vitro and was identified as one of two human homologs of the Saccharomyces cerevisiae NER gene product Rad23. Recombinant hHR23B has previously been shown to significantly stimulate the NER activity of recombinant human XPC protein (rhXPC). In this study we identify and functionally characterize the XPC-binding domain of hHR23B protein. We prepared various internal as well as terminal deletion products of hHR23B protein in a His-tagged form and examined their binding with rhXPC by using nickel-chelating Sepharose. We demonstrate that a domain covering 56 amino acids of hHR23B is required for binding to rhXPC as well as for stimulation of in vitro NER reactions. Interestingly, a small polypeptide corresponding to the XPC-binding domain is sufficient to exert stimulation of XPC NER activity. Comparison with known crystal structures and analysis with secondary structure programs provided strong indications that the binding domain has a predominantly amphipathic alpha-helical character, consistent with evidence that the affinity with XPC is based on hydrophobic interactions. Our work shows that binding to XPC alone is required and sufficient for the role of hHR23B in in vitro NER but does not rule out the possibility that the protein has additional functions in vivo.

Amino Acid Sequence↗
PubMed1997

Experimental IgA nephropathy induced by a low-dose environmental mycotoxin, nivalenol.

Based on the hypothesis that IgA nephropathy (IgAN) is triggered by some exogenous antigen(s) which induces dysregulation of the mucosal immune system, we developed an experimental model of orally induced IgAN by an environmental mycotoxin, nivalenol (NIV), which often contaminates agricultural products in Southeast Asia and Japan. In the present study, low doses of oral NIV reproducibly induced significant IgA deposits in the glomerular mesangium and elevated serum IgA levels in mice irrespective of the strain; the degree of immunopathological changes analogous to human IgAN was associated with the dose and duration of NIV treatment. Furthermore, a competitive enzyme-linked immunosorbent assay with an NIV analogue-protein conjugate disclosed that the IgA antibody in the sera from the NIV model mice had a higher affinity to the mycotoxin. Conclusively, these findings suggest that NIV induces some pathological changes in mice which resemble those in human IgAN, and that this mycotoxin is associated with pathogenesis in some types of glomerulonephritis.

Animals↗
PubMed1997

Inactivation of human viruses by povidone-iodine in comparison with other antiseptics.

Inactivation of a range of viruses, such as adeno-, mumps, rota-, polio- (types 1 and 3), coxsackie-, rhino-, herpes simplex, rubella, measles, influenza and human immunodeficiency viruses, by povidone-iodine (PVP-I) and other commercially available antiseptics in Japan was studied in accordance with the standardized protocol in vitro. In these experiments, antiseptics such as PVP-I solution, PVP-I gargle, PVP-I cream, chlorhexidine gluconate, alkyldiaminoethyl-glycine hydrochloride, benzalkonium chloride (BAC) and benzethonium chloride (BEC) were used. PVP-I was effective against all the virus species tested. PVP-I drug products, which were examined in these experiments, inactivated all the viruses within a short period of time. Rubella, measles, mumps viruses and HIV were sensitive to all of the antiseptics, and rotavirus was inactivated by BAC and BEC, while adeno-, polio- and rhinoviruses did not respond to the other antiseptics. PVP-I had a wider virucidal spectrum, covering both enveloped and nonenveloped viruses, than the other commercially available antiseptics.

Adenoviridae↗
PubMed1997

HLA-A2402-restricted and tumor-specific cytotoxic T lymphocytes from tumor-infiltrating lymphocytes of a child with Wilms' tumor.

The existence of specific immunity against pediatric tumors is not well studied. We report here the CD3+CD4-CD8+ cytotoxic T lymphocyte (CTL) line established from tumor-infiltrating lymphocytes (TIL) of a 3-mo-old child with Wilms' tumor. This CD3+CD4-CD8+ CTL line showed cytotoxicity against the HLA-A2402+ tumor cells including the autologous tumor, adenocarcinomas from various organs (colon, stomach, lung, and ovary), and an esophageal squamous cell carcinoma. No other cell lines examined, including HLA-A2402- tumors, K562 cells, or HLA-A2402+ normal cells were lysed by this CTL line. This CTL line recognized an HLA-A2402- ovarian adenocarcinoma transfected with HLA-A2402 cDNA. These results suggest the existence of HLA-A2402-restricted and tumor-specific CTL at the tumor site of a child with Wilms' tumor.

Base Sequence↗
PubMed1997

Immunosuppressive effects of gallic acid and chebulagic acid on CTL-mediated cytotoxicity.

Gallic acid (GA) and chebulagic acid (CA) were isolated from the extract of a herbal medicine, kashi (myrobalans: the fruit of Terminalia chebula) as active principles that blocked the cytotoxic T lymphocyte (CTL)-mediated cytotoxicity. GA and CA inhibited the killing activity of CD8+ CTL clone at IC50 values of 30 microM and 50 microM, respectively. Granule exocytosis in response to anti-CD3 stimulation was also blocked by GA and CA at the equivalent concentrations.

Animals↗
PubMed1997

Pharmacological properties of traditional medicines. XXIII. Searching for active compounds in the blood and bile of rats after oral administrations of extracts of sansohnin [symbol: see text].

We made a trial of searching for the bioactive substances from Sansohnin [symbol: see text]. The blood and bile of rats after the oral administration of extracts of Sansohnin were analyzed by three-dimensional high-performance liquid chromatography (3D-HPLC). In blood, spinosin and feruloyl spinosin were found after the oral administration of a butanol extract of Sansohnin. In bile, spinosin and feruloyl spinosin were also identified after the oral administration of a water extract of Sansohnin. Spinosin and feruloyl spinosin induced the prolongation of hexobarbital sleeping time in mice at doses of 50 and 100 mg/kg, respectively. We concluded that spinosin and feruloyl spinosin were the bioactive constituents of Sansohnin. It was assumed that spinosin and feruloyl spinosin circulated through the intestine and liver, therefore, these results will provide support for the sedative and hypnotic use of this crude drug in Oriental medicine.

Administration, Oral↗
PubMed1997

Pyrrole butyric acid derivatives as inhibitors of steroid 5 alpha-reductase.

A series of pyrrole butyric acid derivatives was synthesized and evaluated for inhibitory activity on human and rat steroid 5 alpha-reductase in vitro and ex vivo. 3-Benzoyl-4-alkylpyrrole-1-butyric acids and 1-methyl-2-alkyl-3-benzoylpyrrole-5-butyric acid derivatives were effective inhibitors. Structure activity relationships were evaluated among the 37 compounds synthesized. Compound 37 (HQL-1069) shows potent inhibitory activities against both rat and human 5 alpha-reductase.

5-alpha Reductase Inhibitors↗
PubMed1997

Preference of sheep and goats for extracts from high-grain concentrate.

Appetite stimulants were extracted and partially isolated from high-grain concentrate. The stimulants were fed daily and were palatable to sheep and goats used in the experiments. The stimulative effects were tested by comparing the intake of two types of hay: with or without the extracts. Diethylether and n-pentane extracts of the concentrate stimulated feeding in sheep (P < .01 and P < .05, respectively). However, methanol extracts had no significant stimulative effect on selective feeding in sheep. Goats also preferentially fed on hay sprayed with the diethyl ether extracts (P < .01). The diethyl ether extracts were divided into acid, neutral, and basic fractions. Sheep and goats had a marked preference for the acid fraction only (P < .01 and P < .05, respectively). These results suggest that specific chemicals to increase palatability of hay are present in high-grain concentrate and that the chemical are nonpolar, acidic substances.

Animals↗
PubMed1997

Development of cancer vaccine by tumor rejection antigens.

Identification of the MAGE genes allowed us the molecular approach to identify genes encoding tumor rejection antigens expressed on human cancer cells. MAGE-1 proteins are normal tissue antigens compartmentalized in the particular testicular cells playing an important role in the early phase of the spermatogenesis. The MAGE-1, -2, -3, -4 and -6 genes are preferentially expressed in many different cancers at both the mRNA and protein levels. The MAGE genes, particularly MAGE-1, became positive in relatively advanced stages of cancers and recurrent cancers. Approximately one-third to half of human cancers except for myelo-monocytic leukemia expressed at least one of these MAGE genes. The MAGE gene products shall be appropriate target molecules for development of new cancer vaccine.

Animals↗
PubMed1997

Intake stimulants in perennial ryegrass (Lolium perenne L.) fed to sheep.

Few studies exist on intake stimulants in forage plants, although a large amount of research has been conducted on deterrents to the feeding behavior of herbivore livestock. To study intake stimulants in plants, chemical components of perennial ryegrass were extracted, fractionated, and examined for their effects on the feeding behavior of sheep. Methanol extracts were found to be stimulants, and pentane extracts tended to be deterrents. The ethyl acetate fraction of the methanol extracts stimulated feeding, and the basic ethyl acetate-soluble fractions of the methanol extracts were bioactive. These results suggest that the basic and less volatile chemicals in perennial ryegrass stimulate feeding in sheep in the absence of other cues.

Acetates↗
PubMed1997

Detection of influenza virus RNA in peripheral blood mononuclear cells of influenza patients.

Gastroenteritis, arthralgaia and myalgia are frequently associated with influenza virus infections in humans. One explantation for these symptoms may be extrarespiratory transmission of virus by peripheral blood mononuclear cells (PBMC). We tried to detect genomic viral RNA of the nucleoprotein (NP) and H3 subtype hemagglutinin (HA) genes by the method of RT-PCR in PBMC of 18 children aged 1-14 who suffered from an influenza outbreak in the Kansai district of Japan between December 1992 and February 1993. Three of the 18 samples were RT-PCR positive. The NP gene sequence observed in one patient's PBMC was identical to that obtained from his throat swab fluid. The HA gene sequences observed in the two other PBMC differed from those of RT-PCR-amplified DNA from throat swabs by an order of 3-9 nucleotides. We believe these results suggest the presence of a PBMC-associated virus.

Adolescent↗
PubMed1997

[Evaluation of three-dimensional CT angiography (3D-CTA) for the diagnosis of cerebral vasospasm].

We evaluated the usefulness of three-dimensional CT angiography (3D-CTA) for the diagnosis of cerebral vasospasm following subarachnoid hemorrhage (SAH). Eleven patients with SAH who were suspected of having cerebral vasospasm on the basis of their clinical symptoms were examined by 3D-CTA with a spiral CT scanner after an intravenous bolus administration of contrast medium. 3D-CTA revealed vasospastic changes of the cerebral vessels in eight patients. Conventional angiography was performed in six patients immediately after the 3D-CTA examination, and demonstrated the cerebral vasospasm. In eight patients, a second 3D-CTA was performed with the same technique one week after the first 3D-CTA examination. The second 3D-CTA showed the cerebral vessels without vasospastic change. In conclusion, 3D-CTA is a promising, minimally invasive strategy for the assessment of cerebral vasospasm.

Cerebral Angiography↗
PubMed1997

[A case of chronic inflammatory demyelinating neuropathy associated with antibodies to gangliosides GM1 and GalNAc-GD1a].

In January 1993, a 43-year-old man was admitted to our hospital for left wrist-drop. Neurological examinations revealed asymmetrical distal weakness in the upper limbs. Deep tendon reflexes were normal in all 4 limbs. Sensory and autonomic nervous functions were intact. CSF examinations were within normal limits. Thin-layer chromatography with immunostaining revealed serum antibodies that reacted with GM1 and GalNAc-GD1a. Motor nerve conduction studies revealed abnormal temporal dispersion, and a low amplitude of compound muscle action potential in the left radial nerve. Neurological symptoms gradually improved with prednisolone over one and a half years. He was hospitalized again in January 1995, because of right wrist-drop and slight sensory loss of the limbs. Those findings were improved by methylprednisolone (1,000 mg/day) for 3 days. The interval until maximal disability in this patient was more than one month for each admission. This case must belong to inflammatory demyelinating neuropathy.

Acetylgalactosamine↗
PubMed1997

[Thymic carcinoma associated with pulmonary sarcoidosis].

A 54-year-old man who worked as a farmer was admitted to the hospital in August 1989 because of bilateral hilar adenopathy that was detected during a mass screening. Laboratory examination showed a high serum lysozyme level and the PPD skin test was negative. Examination of a specimen obtained by transbronchial lung biopsy revealed non-caseous epithelioid cell granuloma. Sarcoidosis was diagnosed. The patient was not treated, and the bilateral hilar adenopathy had lessened by 1992. The patient was readmitted to our hospital because of right hilar and upper mediastinal enlargement seen on a chest radiograph in April 1994. Computed tomography and magnet resonance imaging disclosed an anterior mediastinal tumor in contact with the right upper lobe, the left inominate vein, and the pericardium. Bronchoscopy showed no abnormality in the right upper-lobe bronchus. Examination of a specimen obtained from the B3b bronchus showed no evidence of malignant cells. Examination of a tumor specimen obtained by transdermal biopsy showed squamous cell carcinoma. After the patient underwent combination chemotherapy, the tumor ws resected, along with the right upper lobe, the left inominate vein, and the pericardium, which were difficult to separate from the tumor. Postoperative pathological examination showed that squamous cell carcinoma was intermingled with normal thymus tissue. We believe that squamous cell carcinoma originated in the thymus. Non-caseous epithelioid cell granulomas were also found in the resected right upper lobe and in a mediastinal lymph node. The patient was discharged after post-operative irradiation of the mediastinum. Thymic carcinoma is rare, and sarcoidosis in a patient with thymic carcinoma is very rare. T lymphocytes are very important in the pathogenesis of sarcoidosis, and the thymus is involved in the growth and differentiation of T lymphocytes. The occurrence of these two diseases in one patient is interesting, but the relationship is not clear.

Carcinoma, Squamous Cell↗
PubMed1997

Renovascular hypertension may cause nephrotic range proteinuria and focal glomerulosclerosis in contralateral kidney.

Little attention has been paid to nephropathies and proteinuria in renovascular hypertension (RVH). Recently there has been a growing interest in the conditions induced by RVH. 10 cases of RVH were diagnosed by angiography and renin sampling from renal veins in the last 6 years in our hospital. The patients were all male and mean age was 64 +/- 8 (SD) years. Data were as follow: protein excretion was 3.8 +/- 2.2 g/day (> or = 3.5 g/day in 8 patients), sBP 202 +/- 24 mmHg, dBP 113 +/- 17 mmHg, serum renin concentration 64 +/- 45 pg/ml, and ipsilateral/contralateral renal vein renin ratio 3.3 +/- 1.0. RVH was treated by nephrectomy in 3 patients, percutaneous transluminal renal angioplasty (PTA) in 2, and angiotensin converting enzyme inhibitors (ACE-I) administration in 8. Biopsies were performed on contralateral kidney in 4 patients. Focal segmental glomerulosclerosis (FGS) was found in 3 patients, and nephrosclerosis in 1, whereas only nephrosclerosis was found in nephrectomized kidneys in all 3 patients. After nephrectomy, PTA and the treatment by ACE-I, not only blood pressure but also proteinuria was markedly reduced. These findings suggest that severe stenosis of the renal artery led to renal ischemia, which activated renin excretion, to cause glomerular hyperfiltration through vasoconstriction of the efferent arterioles in the contralateral kidney. FGS-like lesion thus induced appeared to have caused massive proteinuria.

Aged↗