Biomedical subjects

H Inagaki

Publications and source records attributed to H Inagaki.

At least 109 records · Page 6Linked to original sources

PubMed1996

Osteonectin gene expression in fibrotic liver.

Osteonectin is an extracellular matrix (ECM) protein which is secreted by various cell types, and regulates tissue remodeling and cell proliferation. In the present study, we have examined the expression of osteonectin in fibrotic liver. Osteonectin transcripts were undetectable in normal liver, however, the abundant expression of the osteonectin gene was detected in fibrotic liver. The transcripts of osteonectin were only detected in hepatic lipocytes and the number of lipocytes was increased in fibrotic liver. These results suggested that in fibrotic liver, enhanced osteonectin expression may play an important role in liver fibrosis.

Animals↗

PubMed1996

Gastric syphilis: polymerase chain reaction detection of treponemal DNA in pseudolymphomatous lesions.

Syphilis is an unexpected diagnosis in the stomach. To establish the diagnosis, evidence of Treponema pallidum in the gastric lesion is necessary. However, it is sometimes difficult to prove the presence of the organisms by conventional methods. The authors describe two cases of early gastric syphilis with pseudolymphomatous histology in which T pallidum gene was detected by the polymerase chain reaction (PCR) using paraffin biopsy sections. The gastric lesion of each case endoscopically and histologically simulated that of malignant lymphoma. However, no clonality was proved by immunohistochemistry or PCR gene rearrangement analysis. No spirochetal organisms were detected with certainty by Warthin-Starry silver stain, whereas the organisms were shown by immunofluorescent stain in one patient. A PCR study showed the treponemal DNA in both patients, and its validity was supported by a direct sequencing and a restriction enzyme digestion. Positive results of serological tests for syphilis and regression of the lesions after antisyphilitic treatment were confirmatory of the diagnosis. Gastric syphilis should be considered as a differential diagnosis when an atypical lymphoid infiltrate fails to show monoclonality. The present PCR method would be helpful in showing T pallidum using routinely processed small biopsy specimens as the tissue source.

Adult↗

PubMed1996

Induction of apoptosis in primary culture of rat hepatocytes by protease inhibitors.

There is growing evidence that suggests the involvement of intracellular proteases in the process of apoptosis or programmed cell death. In this study, we have demonstrated that leupeptin, a cysteine protease inhibitor, can significantly increase the incidence of both apoptotic nuclear morphology change and internucleosomal DNA fragmentation in primary cultured hepatocytes in the absence of known apoptotic stimuli for hepatocytes. On the other hand, aspartic and serine protease inhibitors showed little or no effects on the apoptotic changes. In addition, we found that the apoptotic changes could be induced by chloroquine, an inhibitor of lysosomal proteolysis, but could not be induced by calpain inhibitors. These data suggest that inhibition of lysosomal cysteine proteases may induce apoptosis in primary cultured hepatocytes.

Animals↗

PubMed1996

Increased susceptibility to primary infection with Listeria monocytogenes in germfree mice may be due to lack of accumulation of L-selectin+ CD44+ T cells in sites of inflammation.

The host defense of germfree (GF) mice against primary infection with Listeria monocytogenes was compared with that of specific-pathogen-free (SPF) mice. In SPF mice, the numbers of bacteria in the peritoneal cavity, liver, and spleen decreased gradually to undetectable levels by day 8 after intraperitoneal infection with a sublethal dose (2 X 10(3) CFU) of L. monocytogenes. On the other hand, the elimination of bacteria in these organs of GF mice was significantly impaired at this stage after inoculation. We have reported previously that T cells coexpressing L-selectin and CD44 play an important role in protection against L. monocytogenes through trafficking to sites of inflammation. Consistent with our previous findings, the number of unique L-selectin+ CD44+ T cells in the peritoneal cavity was remarkably increased on day 8 after infection in SPF mice, whereas such an increase was not evident in GF mice at this stage. Listeria-specific T-cell proliferation was normally detected in the lymph node cells of GF mice inoculated with L. monocytogenes, whereas the T-cell-proliferative response of the peritoneal exudate cells of GF mice was significantly impaired compared with that of SPF mice. These results suggest that the priming of T cells against listerial antigens normally occurs in the peripheral lymphoid organs of GF mice but the trafficking of the activated T cells to the inflamed sites may be severely impaired in GF mice, resulting in increased susceptibility to infection with L. monocytogenes.

Animals↗

PubMed1996

Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function.

OBJECTIVE: To investigate the value of a giant negative T wave (> or = 1.0 mV) in precordial leads of 12-lead electrocardiograms in the acute phase of Q wave myocardial infarction as a predictor of myocardial salvage. METHODS: Coronary angiographic and electrocardiographic findings, left ventricular ejection fraction in the chronic stage, and levels of cardiac enzymes were compared in patients with myocardial infarction with (group GNT, n = 31) and without (group N, n = 20) a giant negative T wave. GNT patients were divided into two subgroups according to the presence (GNT:R[+], n = 10) or absence (GNT: R[-], n = 21) of R wave recovery with an amplitude > or = 0.1 mV in at least one lead that had shown Q waves. RESULTS: The maximum level of creatine kinase and the total creatine kinase were lower in group GNT compared with group N (P < 0.05). The left ventricular ejection fraction was higher in group GNT than in group N (P < 0.05). The maximum creatine kinase and total creatine kinase were lower in GNT:R(+) than in GNT:R(-) (P < 0.01). The left ventricular ejection fraction was higher in GNT:R(+) than in GNT:R(-) (P < 0.01). The frequency of R wave recovery was significantly higher when giant negative T waves appeared within 100 h of myocardial infarction or when the maximum potential was > or = 1.4 mV. The appearance of a giant negative T wave > or = 1.4 mV had a sensitivity of 90%, a specificity of 71.4%, a diagnostic accuracy of 77.4%, a positive predictive value of 60%, and a negative predictive value of 93.8% for prediction of R wave recovery. CONCLUSIONS: The appearance of a giant negative T wave, especially within 100 h of the onset of myocardial infarction, with a maximum potential of > or = 1.4 mV, may predict a reappearance of the R wave and a better left ventricular function in patients in the chronic stage of anterior myocardial infarction.

Cardiac Catheterization↗

PubMed1996

[A new solid-phase extraction method for human urinary 3-methoxy-4-hydroxyphenylethyleneglycol].

A new solid-phase extraction procedure for urinary 3-methoxy-4-hydroxy-phenylethyleneglycol (MHPG) was established. Sep-Pak Diol cartridge was used, because MHPG is a neutral and alcoholic compound. Aqueous samples were adsorbed to the cartridge, then MHPG was eluted by the addition of ethyl acetate. After the eluate was evaporated, the residuum was dissolved with HPLC mobile phase and injected into HPLC. The extraction procedure was highly specific to MHPG, and none of other acidic catecholamine metabolites, such as vanillylmandelic acid (VMA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), was extracted. The recovery of MHPG using this method was over 90% and higher than those using previously described methods such as liquid-liquid extraction with ethyl acetate. Of the three vanillyl alcohol isomers, isovanillyl alcohol was the most suitable as an internal standard for the correction of column-to-column variation of the recovery. Human urinary unconjugated MHPG extracted by the new procedure could be measured by HPLC with a fluorescence detection. Further complicated derivatization and more sensitive detection systems, such as GC-MS and HPLC-electrochemical detector (ECD), were not needed due to high selectivity and high recovery of the extraction procedure. In addition, the urinary total (conjugated plus unconjugated) MHPG content could also be determined by the same procedure after an enzymatic hydrolysis of conjugated MHPG. The newly developed extraction procedure was simple, rapid and highly specific, and might be applicable to the analysis of MHPG in various body fluids.

Chromatography, High Pressure Liquid↗

PubMed1995

Evaluation of contact sensitivity to formaldehyde and tetramethylthiuram monosulfide using a modified lymphocyte transformation test.

To examine the validity of a modified lymphocyte transformation test for evaluating contact hypersensitivity from weak sensitizers, guinea pigs were sensitized with formaldehyde (F) or tetramethylthiuram monosulfide (TMTM) using the maximization test procedure. Lymph node cells from the animals were then cultured with F or TMTM, in the presence or absence of epidermal cells (EC). Transformed lymphocyte counts were evaluated by uptake of 3H-thymidine. Nonsensitized guinea pigs were used as controls. The lymphocytes from sensitized guinea pigs showed stronger blastogenesis when cultured with F or TMTM in the presence of EC than when the sensitizers were not added to the culture and the response depended on the concentration of F or TMTM. Cultures in the absence of EC also showed significant enhancement of blastogenesis by F or TMTM, but the responses were significantly weaker than those in the presence of EC. Lymphocytes from the control animals did not show significantly enhanced blastogenesis in response to F or TMTM, even when EC was added to the cultures. The results suggested that contact sensitivity for weak sensitizers can be evaluated by this modified lymphocyte transformation test, especially when lymph node cells were co-cultured with EC.

Analysis of Variance↗

PubMed1995

Insertion of a novel transposable element in the tyrosinase gene is responsible for an albino mutation in the medaka fish, Oryzias latipes.

In the medaka fish (Oryzias latipes) many mutants for body color have been isolated. A typical example is the recessive oculocutaneous albino mutant i, which has amelanotic skin and red-colored eyes with no tyrosinase activity. To cast light on the molecular basis of the albino mechanism, we performed Southern blot analysis of genomic DNA from the mutant with an authentic tyrosinase gene probe; the results demonstrate that an extra 1.9 kb fragment is present inside the first exon. The insertion is responsible for the oculocutaneous albinism. About 80 copies of this fragment are present in the genomes of albino-i and wild-type fish; these repeated sequences are here designated Tol1 elements and the particular element found in the tyrosinase gene of albino-i is denoted Tol1-tyr. The nucleotide sequence of Tol1-tyr shows that the fragment (i) carries terminal inverted repeats of 14 bp, and (ii) is flanked by duplicated 8 bp segments of the host chromosome. These are properties of DNA-mediated transposable elements. Comparison of the nucleotide sequence of Tol1-tyr with other sequences in DNA databases, with special attention to sequences of transposable elements known to date, did not reveal any similarity. Thus, Tol1 constitutes a hitherto unknown family of DNA transposable elements.

Albinism↗

PubMed1995

Differential expression of transforming growth factor-alpha and epidermal growth factor during postnatal development of rat submandibular gland.

The concentration and the localization of transforming growth factor (TGF)-alpha and epidermal growth factor (EGF) in the submandibular glands (SMGs) of male Wistar rats of different ages (postnatal 0 to 10 weeks of age) were examined. Highest levels of TGF-alpha were seen early, at postnatal day 0; the levels dropped thereafter in an age-dependent manner, while EGF was not detectable before the third postnatal week. Immunoreactive localization of EGF was restricted to the granules of the granular convoluted tubule (GCT) cells in the mature SMGs, whereas TGF-alpha was observed throughout postnatal development over the entire duct system. TGF-alpha was demonstrated in the cytoplasm at early stages when the GCT granules were not observed and was also located on the granules at the late stage, as was the case for EGF, indicating that TGF-alpha is colocated with EGF in the mature SMG. These results demonstrate the differences between the expression of TGF-alpha and that of EGF in the developing rat SMG.

Age Factors↗

PubMed1995

Synthetic and structural studies of alpha-sialyl-(2-->6) and alpha-sialyl-(2-->3) 1-deoxynojirimycin derivatives potentially useful for biomedical applications.

Suitably protected derivatives of 1-deoxynojirimycin (1,5-dideoxy-1,5-imino-D-glucitol, DNJ) and its D-galacto analog were coupled with 2-thioglycosides of N-acetylneuraminic acid. The resulting disaccharides were converted into a variety of alpha-sialyl-(2-->6)-and alpha-sialyl-(2-->3)-DNJ derivatives, including the cyclic lactams 6-O-(5-acetamido-3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyrano sylono- 1',5-lactam)-1,5-dideoxy-1,5-imino-D-glucitol and -D-galactitol. The structural features of the synthetic compounds were investigated by ion-spray mass and 1H NMR spectrometry. The 1C4 conformation of N-tert-butoxycarbonyl-DNJ, a synthetic intermediate having the gluco configuration, was confirmed by X-ray crystallography.

1-Deoxynojirimycin↗

PubMed1995

Albumin synthesis by rat hepatocytes cultured on collagen gels is sustained specifically by heparin.

We investigated the influence of various kinds of glycosaminoglycans (GAGs) in collagen gels on the maintenance of albumin synthesis in primary culture of rat hepatocytes. Among the GAGs examined (heparin, heparan sulfate, keratan sulfate, chondroitin sulfate A, dermatan sulfate, and hyaluronic acid), only heparin-containing collagen gel cultures could significantly sustain albumin synthesis. However, other GAGs, such as heparan sulfate and keratan sulfate, had almost no effect on the maintenance of albumin synthesis. Heparin in collagen gels exhibited a dose-dependent effect on albumin synthesis: heparin at 400 micrograms/ml-collagen solution maintained albumin synthesis for over 3 weeks. On the other hand, when an equivalent amount of heparin was added directly to the collagen gel culture medium, it prolonged albumin synthesis for only 10 days. The results demonstrate that specific regulation of albumin synthesis by heparin was significantly promoted by coincubating it with collagen, suggesting that some specific interaction between heparin and collagen might be of importance for the maintenance of hepatocyte functions.

Albumins↗

PubMed1995

Transforming growth factor-alpha in human submandibular gland and saliva.

A sensitive sandwich enzyme immunoassay (EIA) for transforming growth factor-alpha (TGF-alpha) utilizing a polyclonal antibody that recognizes limited epitopes of both human TGF-alpha and rat TGF-alpha in combination with a monoclonal anti-TGF-alpha IgG1 galactosidase conjugate was developed. This assay shows no cross-reactivity with human epidermal growth factor. We can quantify the TGF-alpha level in not only human TGF-alpha (detection limit: 1 pg/ml), but also rat TGF-alpha (detection limit: 10 pg/ml) by virtue of cross-reactivity. Employing this assay system, we demonstrated that TGF-alpha is present in both human submandibular glands and submandibular/sublingual saliva.

Animals↗

PubMed1995

p53 protein expression and p53 gene mutation in thymic epithelial tumors. An immunohistochemical and DNA sequencing study.

p53 protein expression in 34 thymic epithelial tumors was examined immunohistochemically, and p53 gene mutation was detected in selected cases by DNA sequencing, using formalin-fixed and paraffin-embedded tissues. The tumors comprised 12 noninvasive thymomas, 9 invasive/metastatic thymomas, and 13 thymic carcinomas. All the tumors were immunoreactive for p53 protein. The p53-positive tumor cells in noninvasive thymoma were less than 10% (low expressor) in 7 cases and 10% to 50% (moderate expressor) in 5 cases. In invasive/metastatic thymoma, two were low expressors and seven were moderate expressors. In thymic carcinomas, there were nine moderate expressors and four high expressors (with > 50% positive cells). There was significant difference in p53 protein immunopositivity between thymic carcinoma and each of the noninvasive or invasive/metastatic thymomas. The DNA sequencing study confirmed the presence of p53 gene point mutation in all 10 cases examined, including three low expressors. These results suggest that p53 gene mutation is an early event in thymic tumorigenesis, and the p53 protein-positive cells increase with the progression of the tumor. Immunostaining reactivity of p53 may be a useful adjunct to differentiate thymic carcinoma from thymoma.

Adult↗

PubMed1995

DNA fragmentation induced in high-cell-density culture of primary rat hepatocytes is an active process dependent on energy availability, gene expression, and calmodulin.

We previously reported that internucleosomal DNA fragmentation, a biochemical feature of apoptosis, was induced spontaneously in high-cell-density culture of adult rat hepatocytes. To understand better the intracellular mechanism of the DNA fragmentation in this system, we have examined the effects of several inhibitors of specific intracellular functions on the DNA fragmentation. We found that the DNA fragmentation could be suppressed by treatment of the cells with inhibitors of mitochondrial respiration, KCN and CCCP, or a protein synthesis inhibitor, cycloheximide. We also demonstrated that calmodulin inhibitors, chlorpromazine and W-7, could suppress the DNA fragmentation. Together, these results lead us to conclude that the DNA fragmentation in hepatocytes cultured at high cell density is an active process dependent on energy availability, gene expression, and calmodulin, rather than a passive event resulting from necrosis. However, by analyzing the incidence of apoptotic morphology during culture, we found that only 2-3% of cells exhibited apoptotic morphology, while the incidence of DNA fragmentation was estimated to be much higher. Based on these results, we estimated that the DNA fragmentation may result from the incomplete progression of apoptosis or from the occurrence of another type of active cell death.

Animals↗

PubMed1995

p53 protein and proliferating cell nuclear antigen in eccrine poroma and porocarcinoma. an immunohistochemical study.

The expression of p53 protein and proliferating cell nuclear antigen (PCNA) in 18 eccrine poromas and four porocarcinomas was examined by immunohistochemistry. Immunoreactivity for p53 in eccrine poromas was negative in five tumors, < 10% of tumor cells in one (low expresser), 10-50% in seven (moderate expressers), and > 50% in five (high expressers). The duration of the presence before excision of p53-negative poromas was shorter, and the size of these tumors was smaller in comparison with those of p53-positive poromas. Moreover, all high expressers showed some atypical cells in limited areas. Of the four porocarcinomas, three were high expressers and one a low expresser of p53 protein. The low-expresser tumor showed clinically more rapid growth and histologically no poromatous foci in contrast to the high expressers. No significant correlation was found between p53 protein expression and PCNA positive staining in either eccrine poromas or porocarcinomas. However, the percentages of PCNA-positive cells in porocarcinomas were significantly higher than those in poromas, with no overlapping values. These results suggest that the PCNA index is useful in differentiating between poroma and porocarcinoma and that p53 gene mutation may occur in long-standing eccrine poromas and correlate with atypical changes in histology as well as subsequent progression to porocarcinoma.

Acrospiroma↗

PubMed1995

Monoclonality in gastric lymphoma detected in formalin-fixed, paraffin-embedded endoscopic biopsy specimens using immunohistochemistry, in situ hybridization, and polymerase chain reaction.

Diagnosis of gastric malignant lymphoma remains a challenge, especially when the tissue source is endoscopic biopsy specimens. Once an atypical lymphoid infiltrate is found, demonstration of clonality is the key to establishing a diagnosis of the disease. For this purpose, we evaluated the usefulness of immunohistochemistry, in situ hybridization, and polymerase chain reaction (PCR) using formalin-fixed, paraffin-embedded endoscopic materials from 20 patients with B-cell malignant lymphomas. Template DNA for PCR was obtained by microdissecting Giemsa-stained sections using a serial hematoxylin and eosin section as a guide. Clonal rearrangement bands were demonstrated in 15 of 20 cases (75%) by PCR, whereas expression of monotypic light-chain mRNA was detected in seven of 20 (35%) by in situ hybridization and monotypic light-chain restriction in four of 20 (20%) by conventional immunohistochemistry. Although less sensitive than PCR, in situ hybridization was useful for localizing the expression of target mRNAs with cellular accuracy and with low background staining. In addition, two cases were found to be monoclonal only by in situ hybridization, and not by PCR. The results showed that clonal proliferation is detected with the greatest sensitivity with PCR using small routinely processed biopsy specimens and that a difficulty with the PCR method in terms of cellular localization was partially overcome using a microdissection procedure that provided at least tissue-level accuracy.

Base Sequence↗

PubMed1995

Successful pregnancy in a Churg-Strauss syndrome patient with a history of intrauterine fetal death.

Allergic granulomatosis and angiitis was first reported as a disease entity separate from polyarteritis nodosa in 1951 by Churg and Strauss. It is characterized by bronchial asthma, eosinophilia, and vasculitis and is especially rare in women of reproductive age, though, when present, may be associated with fetal mortality in pregnancy. We report a successful pregnancy in a patient who previously experienced intrauterine fetal death at 30 weeks of gestation.

Adult↗

PubMed1995

A protective role of gamma delta T cells in primary infection with Listeria monocytogenes in autoimmune non-obese diabetic mice.

We investigated the host defense mechanism in primary infection with Listeria monocytogenes in non-obese diabetic (NOD) mice at pre-diabetic stage showing an impaired responsiveness of the alpha beta T cells to T-cell receptor (TCR) triggering. The NOD mice showed a deteriorated resistance at the late stage after an intraperitoneal infection with L. monocytogenes compared with BALB/c and C57BL/6 mice as assessed by bacterial growth in organs. Consistent with our previous findings, a prominent increase in number of gamma delta T cells was evident at the early stage after infection, while generation of Listeria-specific alpha beta T cells was impaired in these mice. In vivo administration of anti-TCR gamma delta monoclonal antibody (mAb) allowed L. monocytogenes to grow exaggeratedly in the NOD mice. These results imply that gamma delta T cells may be mainly involved in protection against primary infection with L. monocytogenes in NOD mice.

Animals↗