Biomedical subjects

H Yoshida

Publications and source records attributed to H Yoshida.

At least 577 records · Page 32Linked to original sources

PubMed1999

Removal of salt and organic acids from solution used to season salted Japanese apricots (ume) by electrodialysis, precipitation and adsorption.

With the aim of repeatedly reusing the solution used to season salted ume (Japanese apricot), we investigated its desalting and deacidification by electrodialysis, precipitation, and adsorption. Although NaCl and acids could be easily removed from used seasoning solution by electrodialysis, useful substances such as amino acids were removed at the same time. Precipitation using Ca(OH)2 could remove only organic acids, but the treated solution became bitter. Two weakly basic commercial resins, DIAION WA30 and Chitopearl CCS, adsorbed organic acids selectively. Chitopearl CCS in particular selectively adsorbed citric acid in the used seasoning solution without also adsorbing useful substances. The equilibrium data of a citric acid, which was a main organic acid, were correlated by the Langmuir equation. The saturation capacity decreased with increasing concentrations of NaCl in the solution but the equilibrium constant did not change. By combining electrodialysis and adsorption, NaCl and organic acids could be removed while amino acids largely remained. The resultant solution was considered to be suitable for repeated reuse.

Journal Article↗

PubMed1999

Subcellular localization of fructosyl amino acid oxidases in peroxisomes of Aspergillus terreus and Penicillium janthinellum.

Fructosyl amino acid oxidase (FAOD) is the enzyme catalyzing the oxidative deglycation of Amadori compounds, such as fructosyl amino acids, yielding the corresponding amino acids, glucosone, and H(2)O(2). In a previous report, we determined the primary structures of cDNAs coding for FAODs from two fungal strains Aspergillus terreus AP1 and Penicillium janthinellum and we found that both fungal FAODs included the putative peroxisome targeting signal 1 (PTS1) at the carboxyl terminal (Yoshida, N. et al., Eur. J. Biochem., 242, 499-505, 1996). In this study, we determined the intracellular localization of FAODs in these two fungi. Subcellular fractionation experiments and immuno-electronmicroscopic observations, together with the previous findings indicated that the FAODs were localized in peroxisomes of A. terreus AP1 and P. janthinellum. These FAODs were also found to belong to a new member of "peroxisomal sarcosine oxidase family protein" in eucaryotic cells.

Journal Article↗

PubMed1999

Production of organic acids and amino acids from fish meat by sub-critical water hydrolysis

Fish meat was easily liquefied by hydrolysis under subcritical conditions without oxidants, and aqueous phase and water-insoluble phase containing oil and fat-like solid were formed. Lactic acid found in the raw fish meat (about 0.03 g/g-dry meat) was stable up to the reaction temperature 513 K (3.35 MPa). Pyroglutamic acid was produced with a yield of 0.095 kg/kg of dry meat by 30 min reaction at 553 K (6.42 MPa). Amino acids such as cystine, alanine, glycine, and leucine were produced in the temperature range 513-623 K with a maximum peak at 543 K. Amounts of cystine, alanine, glycine, and leucine produced in 5 min at 543 K (5.51 MPa) were 0.024, 0.013, 0. 009, and 0.004 kg/kg of dry meat, respectively. The oil extracted with hexane contained useful fatty acids such as eicosapentanoic acid (EPA) and docosahexianoic acid (DHA). Thus, subcritical water hydrolysis would be an efficient process for recovering useful substances from organic waste such as fish waste discarded from fish market.

Journal Article↗

PubMed1999

Haematogenous cytokeratin 20 mRNA as a predictive marker for recurrence in oral cancer patients.

We examined the expression of cytokeratin 20 (CK20) mRNA in the peripheral blood of oral squamous cell carcinoma (SCC) patients by reverse transcriptase polymerase chain reaction (RT-PCR). Eleven out of 12 oral SCC patients showed positive RT-PCR results. However, there is no clear relationship between the haematogenous CK20 mRNA and the metastasis. After initial treatment, all of the tumour-free survivors tested showed negative RT-PCR results. CK20 mRNA in peripheral blood can be used as a marker for tumour recurrence but not not for metastasis in oral SCC patients.

Biomarkers, Tumor↗

PubMed1999

Allelic variants in the interleukin-6 gene and essential hypertension in Japanese women.

Genes that can be implicated in hypertension in experimental animals are plausible candidates in the pathogenesis of human hypertension. A recent genome-wide search for quantitative-trait loci (QTL) in hypertensive rats revealed a strong correlation between the interleukin-6 (IL-6) locus on rat chromosome 4 and systolic, diastolic, and mean arterial pressure in this mammalian species. To investigate a possible association between genetic variations of the IL-6 gene and hypertension in humans, we identified two novel single-nucleotide sequence variations, a C/G substitution at -634 in the promoter region and a G/A substitution at 4391 in a 3' non-coding portion of exon 5, and a previous reported sequence variant, an A/T variation in the composition of the AnTn tract around -447 in the promoter region (Fishman D et al. J Clin Invest 1998; 102: 1369-1376), within a test population of 96 Japanese subjects. Allelic associations involving these variations were analyzed in 150 hypertensive and 143 normotensive Japanese women. The distribution of alleles of the three polymorphisms, as well as a dinucleotide repeat present at the IL-6 locus, was similar in the two groups. Therefore, the IL-6 gene appears to play a minimal role in the genetic etiology of essential hypertension in Japanese women.

Aged↗

PubMed1999

Body mass index (weight/height2) or percentage body fat by bioelectrical impedance analysis: which variable better reflects serum lipid profile?

We present population data on percentage body fat (%BF) by bioelectrical impedance analysis (BIA) in 12,287 men and 6657 women aged 30-69 y. In addition, we examined relationships among BMI, %BF and serum lipids (total-cholesterol (TC), HDL-cholesterol (HDLC), TC/HDLC ratio, LDL-cholesterol (LDLC) and triglycerides (TG)) in order to determine whether body mass index (BMI, kg/m2) or %BF by BIA better reflected lipid metabolism. Women had larger %BF than men in all age groups. On the other hand, women aged < 60 y had smaller BMI than corresponding men. Regardless of age, BMI was obviously correlated with %BF (r = 0.743-0.924). As previously reported, high BMI and high %BF were strongly associated with high serum TC/HDLC ratio and TG, and low serum HDLC rather than high serum TC and LDLC. Compared with BMI, %BF by BIA was better correlated with the serum indices except for serum HDLC. These results were found in both sexes, and there was a trend in which younger subjects had stronger correlations among BMI, %BF and serum lipids. Consequently, %BF by BIA (an index of body composition) better reflects serum lipid profile than BMI.

Adipose Tissue↗

PubMed1999

Selective secretion of chemoattractants for haemopoietic progenitor cells by bone marrow endothelial cells: a possible role in homing of haemopoietic progenitor cells to bone marrow.

To elucidate the mechanisms by which haemopoietic progenitor cells lodge in the bone marrow, we examined the secretion of chemoattractants for haemopoietic progenitor cells by bone marrow and lung endothelial cells. The bone marrow endothelial cells, but not lung endothelial cells, secreted chemoattractants for the haemopoietic progenitor cell line, FDCP-2, and normal haemopoietic progenitor cells. Checkerboard analysis demonstrated that the conditioned medium of the bone marrow endothelial cells had chemotactic activity and random motility-stimulating activity. The bone marrow endothelial cells expressed stromal-cell-derived factor-1 (SDF-1) mRNA and produced SDF-1 protein, whereas the lung endothelial cells did not. Adhesion of FDCP-2 cells to the bone marrow endothelial cells was partially inhibited by anti-SDF-1 antibody. These findings suggest that the chemoattractants for haemopoietic progenitor cells including SDF-1 and random motility-stimulating factor(s) selectively secreted by the bone marrow endothelial cells may contribute to the homing of haemopoietic progenitor cells to bone marrow.

Animals↗

PubMed1999

Amplitude and frequency spectrum of temporomandibular joint sounds from subjects with and without other signs/symptoms of temporomandibular disorders.

Temporomandibular joint (TMJ) sound is one of the most commonly recognized signs in patients with temporomandibular disorders (TMD) but is also frequently seen in asymptomatic individuals. Sound recording is therefore only meaningful if the sounds from a normal healthy joint can be differentiated from those in patients. In this study, the amplitude and power spectrum of the TMJ sounds from symptomatic patients and asymptomatic individuals were recorded and compared. The result showed that TMJ sounds from symptomatic patients had a larger amplitude than sounds from asymptomatic subjects. A significant proportion of sounds had frequencies between 2000 and 3000 Hz. It was concluded that the characteristic amplitude is worthy of further study as a sign of possible diagnostic value. Secondly, the bandwidth of the sensors used at electronic TMJ sound recording should not be less than 3000 Hz.

Acoustics↗

PubMed1999

The expression of substance P in human temporomandibular joint samples: an immunohistochemical study.

The expression of neuropeptide substance P was examined in 18 human temporomandibular joint (TMJ) samples with internal derangement of the TMJ, and in 10 control specimens. The examination was carried out using an immunohistological technique, using paraffin-embedded tissue and specific anti-human substance P polyclonal antibody. We noted five characteristic distribution patterns of substance P expression: at the nerves' fibre bundles in the connective tissues of the anterior and/or posterior attachment; around the blood vessels in the attachments; at the margin of the TMJ disc and synovial membrane layer; on the surface of hypertrophic synovial membranes with inflammation and proliferation; and around the newly formed capillaries in the TMJ discs. In TMJs with internal derangement associated with severe pain, we found distinct substance P expression in most of the specimens. The expression was particularly intense at the margin of the TMJ disc and synovial membrane layer, on the surface of hypertrophic synovial membranes and around the newly formed capillaries in the TMJ discs. The clinical symptoms of internal derangement of the TMJ are thought to be associated with the degree of synovitis. We conclude that the expression of substance P seems to be closely related to histopathological changes of the human TMJ with internal derangement.

Adult↗

PubMed1999

Localization of lymph capillaries and blood capillaries in human temporomandibular joint discs.

The localization of lymph capillaries and blood capillaries in the human temporomandibular joint (TMJ) discs was examined immunohistologically with anti-human collagen IV antibody and anti-human von Willebrand factor in 26 human TMJ samples. The 16 internal derangement cases were then compared with the 10 normal control cases. The findings suggested that blood capillaries scarcely existed in all the fields of normal control TMJ discs (5/270, 1.9%) nor did lymph capillaries exist in the normal TMJ discs (0/270, 0%). New growth of blood capillaries had localized in all fields of the internal derangement discs specimens (113/378, 29.9%) and was concentrated in the lower area of the posterior part of the discs. The authors also observed a small distribution of lymph capillaries in all fields of this material (17/378, 4.5%). The new growth of lymph capillaries were always related to the blood capillary distribution and therefore their presence might be directly related to the capillary proliferation.

Adult↗

PubMed1999

The expression of transforming growth factor beta (TGF-beta) in the synovial membrane of human temporomandibular joint with internal derangement: a comparison with tenascin expression.

We examined the expression of the transforming growth factor beta (TGF-beta) in 28 human temporomandibular joint (TMJ) samples (internal derangement of TMJ and control specimens) by an immunohistological method using paraffin-embedded tissues and a polyclonal antibody specific to human TGF-beta. The resulting reaction of TGF-beta expression divided into three types as follows. The first type, around the fibrocyte and in the lacunae of chondrocytes in the disc. The second type, at the stroma of the mildly hypertrophic synovial membrane and severely hypertrophic synovial membrane. The first type was observed in all the cases including the control cases. The second type showed only in the internal derangement of TMJ, and its expression pattern resembled that of tenascin (TN) within the stroma of hypertrophic synovial membranes. In conclusion, TGF-beta and TN were distributed in the affected synovial membrane of TMJ with internal derangement. These findings suggested that TGF-beta and TN might have a close relationship with synovitis, followed by tissue repair.

Adult↗

PubMed1999

How soon can a virological sustained response be determined after withdrawal of interferon therapy in chronic hepatitis C? Tokyo-Chiba Hepatitis Research Group.

Hepatitis C virus (HCV)-RNA status and alanine aminotransferase (ALT) levels determined shortly after interferon (IFN) therapy in patients with chronic hepatitis C do not predict long-term response. To determine the virological sustained response after the completion of IFN therapy, HCV-RNA was measured at the end of treatment and at 3-4 months and 12 months after the completion of therapy in 537 patients with chronic hepatitis C. In 347 patients, HCV-RNA was not detected by polymerase chain reaction (PCR) at the completion of therapy and 175 of these patients (50%) were still PCR negative 12 months later. In contrast, of the 180 patients who were HCV-RNA negative at 3-4 months after completion of therapy, 99% remained negative at 12 months. Normal ALT levels were found in 80, 93 and 95% of patients who were negative for HCV-RNA either at the end of treatment or at 3-4 months and 12 months after the completion of therapy, respectively. Of patients who were HCV-RNA positive, 30, 15 and 20% were found to have normal ALT levels at the same respective time points. To determine a sustained virological response shortly after the completion of therapy, serum HCV-RNA was serially examined in 66 patients negative for HCV-RNA at the end of therapy. Of 31 patients who relapsed, HCV-RNA reappeared in 33, 80, 97 and 100% of patients by 1, 2, 4 and 8 weeks after the completion of therapy. In conclusion, a sustained virological response could be determined with 97 and 99% certainty at 4 weeks and at 3-4 months after the completion of therapy, respectively.

Adult↗

PubMed1999

Obesity affects expression of progesterone receptors and node metastasis of mammary carcinomas in postmenopausal women without a family history.

Possible relationships between risk factors, such as obesity and a family history of breast cancer, and prognostic factors of mammary carcinomas were investigated by examining the body mass index of patients and the expression of estrogen (ER) and progesterone receptors (PgR), c-erbB-2 and p53, grade of histology, size of tumors and nodal status of mammary carcinomas. There was no significant difference in the body mass index of premenopausal patients either with or without a family history. For postmenopausal patients, the body mass index was significantly low in patients with a family history compared with patients without a family history. In premenopausal patients with or without a family history and in postmenopausal patients with a family history, there was no significant difference in the body mass index regardless of the mammary carcinoma prognostic factor, such as expression of ER, PgR, c-erbB-2 and p53, grade of histology, size of tumors and nodal status. However, in postmenopausal patients without a family history, body mass index was significantly high for patients with mammary carcinomas that had PgR expression and node metastasis. These results suggest that obesity may affect the PgR status and nodal status of mammary carcinomas in postmenopausal patients without a family history.

Body Mass Index↗

PubMed1999

Morphological characteristics of lipid accumulation in liver-constituting cells of acid lipase deficiency rats (Wolman's disease model rats).

Lysosomal acid lipase is a hydrolase essential for the intracellular degradation of cholesteryl esters and triglycerides. In the laboratory, rats with congenital deficiency of lysosomal acid lipase and marked accumulation of cholesteryl ester, cholesterol free and triglyceride in livers (Wolman's disease rat or Yoshida rat) that corresponded to human Wolman's disease were found and maintained. The morphological characteristics of accumulated lipids in the livers of affected rats were examined also. Many small lipid droplets and lipid crystals were found in the cytoplasms of hepatocytes and ED1-positive and ED2-positive foamy Kupffer's cells, respectively. Electron microscopically, many electron-lucent lipid droplets with limiting membrane were found in hepatocytes. Foamy Kupffer's cells had many multivesicular bodies with limiting membrane, which contained crivilinear bodies, lipid droplets and crystal clefts. At areas of aggregation of foamy Kupffer's cells forming islets, there were many desmin-positive Ito cells. Small lipid droplets with limiting membrane were also found in the cytoplasm of Ito cells and endothelial cells. These findings, which were obtained by morphological methods, indicated that triglyceride and both cholesteryl ester and free cholesterol accumulated in lipolysosomes mainly in hepatocytes and Kupffer's cells, respectively, and suggest that lysosomal acid lipase could participate in dissolution of the membrane.

Animals↗

PubMed1999

Immunohistochemical study of MIB1 expression in phyllodes tumor and fibroadenoma.

The histogenesis of phyllodes tumor (PT) and fibroadenoma (FA) is closely related, and discrimination between them by histopathological analysis is sometimes problematic. Moreover, objective criteria by which to categorize the grade of malignancy in PT are still controversial. The aim in this study is to clarify whether immunohistochemical evaluation using the MIB1 antibody, which reacts with the ki-67 antigen, correlates with the histological grade of malignancy in PT, and can discriminate between PT and FA. The 47 cases of phyllodes tumor (PT) were categorized into three groups (malignant, 4 cases; borderline, 6 cases; benign, 37 cases) according to the criteria proposed by Azzopardi (1979) and were investigated by immunohistochemistry. There were significant differences in stromal MIB1-index among the three groups (P < 0. 0001), and, unexpectedly, benign PT was easily divided into two groups according only to the MIB1-index. There were significant differences in the stromal MIB1-index (P < 0.001) and stromal cellularity (P < 0.01) between the two benign PT groups. A total of 478 cases of FA was reviewed and these were divided into 403 conventional fibroadenomas (CFA), 36 cellular fibroadenomas (CEFA) and 39 fibroadenomas with focal phyllodes structure (FAPS). All cases of CEFA and FAPS, and 140 cases of CFA were studied by immunohistochemistry. The 21/215 (9.8%) cases of FA, which were designated as FAMIB, showed a high stromal MlB1-index (more than 10/0.0625 mm2). Conversely, 77% cases of FA showed no MIB1-positive stromal cells. The incidence of MIB1-positive epithelium of FAMIB was much higher than that of FA. These results suggest that high proliferative activity may be present in both stromal and epithelial cells of FAMIB. Our study suggests that immunohistochemical evaluation using MIB1 antibody correlates with the histological grade of malignancy in PT, and can select FA with high proliferative activity. However, new objective diagnostic factors useful for discriminating FA from benign PT with a low MIB1-index should be developed.

Adenoma↗

PubMed1999

Recurrence of sigmoid colon carcinoma in the residual urethra after cystectomy.

INTRODUCTION: We report a case of recurrence of sigmoid colon cancer in the residual urethra after cysto-prostato-sigmoidectomy. METHODS/RESULTS: The patient successfully underwent urethrectomy and is currently tumor-free. To our knowledge, this is the first case of recurrence of a non-urothelial malignant tumor in the residual urethra.

Adenocarcinoma↗

PubMed1999

Up-regulation of glomerular extracellular matrix and transforming growth factor-beta expression in RF/J mice.

BACKGROUND: RF/J mice were first reported as a murine model of spontaneous glomerulosclerosis by Gude and Lupton in 1960, but the precise histologic characteristics and immunopathological background of this mouse have not been investigated further. METHODS: Measurements of serum levels of immunoglobulins, anti-single strand DNA (anti-ss-DNA) antibody, complement (C3), and circulating immune complex (IC) were performed. Analyses of glomerular histological and immunopathological lesions in association with the detection of mRNA expression of collagen IV, TGF-beta, matrix protein turnover related enzymes, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2) and platelet-derived growth factor (PDGF) were also performed in young (10-week-old) and elderly (60-week-old) RF/J mice with age-matched BALB/C mice as the controls. RESULTS: High levels of serum IgA and IgG from as early as 20 weeks of age were noted in the RF/J mice. Serum anti-ss-DNA antibody of aged RF/J mice increased up to 23% of that of aged MRL-lpr/lpr mice, and serum C3 concentration significantly decreased with age, reaching lower levels than that of BALB/c mice. IgA-IC levels were significantly high compared to BALB/C mice both in the early and late stages of life, whereas IgG-IC levels were high only in mice younger than 20 weeks. Semiquantitative and quantitative analyzes of renal histopathological findings revealed significantly marked and age-related mesangial matrix expansion in RF/J mice, with increasing frequency of global glomerular sclerosis and tubulointerstitial damage. On the other hand, although precise measurements of glomerular cell numbers also showed an apparent augmentation in both young and old RF/J mice compared to BALB/C mice, glomerular cellularity decreased with age in RF/J mice. Immunohistochemical study revealed massive immunoglobulin deposition from a young age in association with significantly higher accumulation of matrix proteins, such as types I and IV collagen and laminin from the early stage of life. In addition, in these glomeruli, transforming growth factor-beta1 (TGF-beta1) was highly expressed both in young and old mice. The mRNA expression of MMP-2 was up-regulated only in the early stage of life. Although PDGF mRNA of RF/J mice was significantly up-regulated in the early stage of life, the differences between the mice disappeared in the late stage of life. CONCLUSIONS: These findings suggest that in RF/J mice, an immunopathological background inducing high serum immunoglobulin and IC levels from the early stage of life is closely related to mesangioproliferative glomerular lesions mediated by PDGF, and that development of massive extracellular matrix accumulation in glomeruli was induced by up-regulated expression of TGF-beta with inappropriate regulation of protein turnover-related enzyme production.

Age Factors↗

PubMed1999

Ex vivo liver perfusion with arterial blood from a pig with ischemic liver failure.

To simplify liver support using an ex vivo perfused liver, an isolated pig liver was perfused with arterial blood from the recipient pig while monitoring the metabolic capacity of the ex vivo perfused liver. It was possible to perfuse the isolated liver for more than 24 h using arterial blood from a pig with ischemic liver failure. The viability of the isolated liver during support from the liver failure pig was well maintained as evidenced by the high adenylate energy charge (0.815) and a constant ketone body ratio (KBR) of over 1.0 sampled from the hepatic vein. Oxygen consumption (mean, 29.0 microl/min/g of liver) and bile production (mean, 24.2 microl/h/g of liver) were significantly higher in the isolated liver connected to the liver failure pig than in the organ connected to the pig without liver failure (15.5 microl/min/g and 7.3 microl/h/g, respectively). These findings suggest that this liver support system has sufficient metabolic capacity to support a failed liver. Further studies may provide the experimental basis necessary for the clinical application of this device in treatment of patients with acute liver failure.

Animals↗