Improvement of modified two-layer preservation method (PFC/Kyoto solution) in islet isolation from breeder pigs.
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Biomedical subjects
Publications and source records attributed to Y Kawakami.
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The effect of macrophage-colony stimulating factor (M-CSF), which regulates the growth and differentiation of haematopoietic progenitor cells on the growth of ovarian cancer cells was investigated in three ovarian cancer cell lines in vitro. The spontaneous growth of these cells was significantly inhibited by the addition of M-CSF in a concentration-dependent manner over 96 h of culturing. The maximum response was obtained with 10 ng/ml (3857 U/ml) of M-CSF by counting the viable cell number using the trypan blue exclusion assay. [(3)H]-thymidine incorporation by these cells was also suppressed following a 96-h incubation with M-CSF. The inhibitory effect of M-CSF was reversed by the addition of anti-M-CSF monoclonal antibody. Flow cytometric analysis revealed that the treated ovarian cancer cells arrested at the G0/G1 phase of the cell cycle. These cells expressed M-CSF receptors on their surface as detected by Scatchard plot analysis using (125)I-labelled M-CSF. These results indicate that M-CSF has an antitumour activity for ovarian cancer cells and suggest that it can be applied for the treatment of this disease.
The aim of the study was to clarify the role of telomerase component genes in hepatocarcinogenesis and to examine both the relationship between the expression of telomerase component genes and histological differentiation in hepatocellular carcinoma (HCC) and the relationship between expression levels of telomerase component genes and telomerase activity in HCCs. Telomerase is a ribonucleoprotein enzyme composed of a template RNA and several proteins. Recently, three such telomerase component genes have been identified: human telomerase reverse transcriptase (hTERT); human telomerase RNA component (hTERC); and telomerase-associated protein 1 (TEP1). The expression of these components was evaluated in 34 HCCs and 24 non-cancerous liver tissues by reverse transcriptase-polymerase chain reaction (RT-PCR). Expression of hTERT mRNA was detected in most HCCs, but not in the non-cancerous tissues (P<0.01). Expression of hTERC was detected in both HCCs and non-cancerous tissues, but the expression level in HCCs was higher than that in non-cancerous tissues (P<0.01) and tended to increase as histological differentiation became less marked. The expression level of hTERT mRNA correlated with relative telomerase activity (P<0.01). These results suggest that telomerase reactivation during hepatocarcinogenesis might be regulated by only hTERT and an increase in telomerase activity level in tumour progression might be regulated by both hTERT and hTERC.
Eighteen of 56 (32.1%) wild Rana limnocharis from central and south Taiwan were found to contain plerocercoids of Spirometra erinaceieuropaei. This is the first report of S. erinaceieuropaei infections in frogs in Taiwan, with the plerocercoids being recovered from the thigh and back muscles or under the skin. Other species of frogs examined, including nine wild R. latouchii, one wild Buergeria robustus and 110 cultured R. rugulosa were free of infection. The plerocercoids were orally inoculated into four cats; three of which were each given a single plerocercoid and one a dose of three plerocercoids. Daily faecal examination showed that two cats started shedding eggs of S. erinaceieuropaei on day 8 postinfection (PI) and the other two on day 10 PI. The highest eggs per gram and eggs per day for a single worm was found to be 428,000 and 14,416,000 respectively. Only the cat inoculated with three plerocercoids shed proglottids in its faeces during the 2 month observation period.
The objective of this study was to determine if HCV can be transmitted from patient to patient in psychiatric institutions and to determine possible routes of infection. We did a cross-sectional survey of 196 Japanese psychiatric patients tested for HCV and HBV markers and 400 age- and sex-matched controls. Anti-HCV was detected in 10.2% and antibody to hepatitis B core antigen was detected in 44.4% of the patients, a significantly higher prevalence than found among matched controls. A multiple regression logistic analysis was used to identify risk factors that could indicate the route of infection by HCV. Duration of hospitalization, age, razor sharing, and history of surgery proved to be statistically significant independent risk factors associated with positive anti-HCV results [odds ratio (OR), 4.00; 95% confidence interval (CI), CI, 1.74-9.19; OR, 2.19; 95% CI, 1.27-1.3.77; OR, 4.90; 95% CI, 1.29-18.86; OR, 3.35; 95% CI, 0.997-11.3, respectively]. These observations suggest that razor sharing played an important role in the spread of the HCV infection in the institutionalized psychiatric patients we studied.
To determine the effects of interferon treatment, we studied 77 Japanese patients with hepatitis C virus (HCV) infection and normal alanine aminotransferase (ALT). Of 77 patients, 37 were given natural interferon-alpha for 24 weeks, and 40 not given interferon acted as controls. Serum samples were tested for HCV RNA and genotypes by polymerase chain reaction (PCR). HCV RNA levels were measured by competitive PCR. Of 37 treated patients, 11 (29.7%) had sustained elimination throughout a six-month follow-up, while HCV RNA was not eliminated in any untreated patients. At 24 months, the number of patients with elevated ALT was not significantly different between treated (13.5%) and untreated patients (15%). Interferon eliminates HCV RNA in patients with normal ALT without severe side effects. The natural history of HCV infection should be clarified so that the interferon treatment regimen can be tailored to the needs of each patient.
HLA class II alleles and immunoglobulin allotypes were determined in 83 Japanese patients with immune thrombocytopenic purpura (ITP) and 114 race-matched healthy controls. Distribution of DRB and DQB1 alleles as well as G1M(f, z), G2M(n+, n-), and KM(1, (1,2), 3) were not different between ITP patients and healthy controls, while DPB1*0201 was marginally increased in ITP patients vs. healthy controls (51% vs. 28%, Pc= 0.04, OR=2.6 [1.4-4.8]). In contrast, strong associations between anti-glycoprotein autoantibodies and HLA class II genes were found as follows: antiGPIIb-IIIa antibody with DRB1*0405 and DQB1*0401; and anti-GPIb-IX antibody with DRB1*0803 and DQB1*0601. When factors influencing therapeutic responses to splenectomy were examined, a poor response was correlated with the presence of DRB1*0405, DQB1*0401 and anti-GPIIb-IIIa antibody (P=0.01, 0.002, and 0.03, respectively). Our results indicate that HLA class II genes influence the production of anti-glycoprotein antibody specificities rather than the development of ITP. In addition, HLA class II genotyping could be useful in predicting therapeutic responses to splenectomy in Japanese patients with ITP.
T cell responses specific for melanoma cells and melanocytes appear to be involved in the rejection of melanoma tumors, as well as in the development of autoimmune reactions in patients with Vogt-Koyanagi-Harada disease (VKH), sympathetic ophthalmia, or autoimmune vitiligo. Some of the target antigens for those T cells have been isolated using cDNA expression cloning with melanoma reactive T cells derived from lymphocytes tumor infiltrating (TIL) of patients with melanoma. These include melanocyte specific proteins, such as tyrosinase, TRP1, TRP2, gp100, and MART-1, cancer-testis antigens, and mutated peptides derived from genetic alterations in melanoma cells. Some of the melanoma reactive T cells appear to respond to cryptic or subdominant self epitopes in melanosomal proteins. Modification of those epitopes to increase their immunogenicity by replacement of amino acids at primary anchor residues for peptide/MHC binding, allowed an improvement in immunotherapy for patients with melanoma. Targets for autoreactive T cells against melanocytes in those autoimmune disorders remain to be identified. Isolation of novel target antigens is important for understanding these pathological T cell responses, as well as for developing new diagnostic and treatment methods for these diseases. A variety of techniques, including cDNA expression cloning with T cells, serological analysis of recombinant cDNA expression libraries (SEREX), cDNA subtraction with representational differential analysis (RDA), and serial analysis of gene expression (SAGE) are now being applied to identify novel melanoma/melanocyte antigens recognized by T cells and antibodies.
The present study aims to investigate the elasticity of tendon structures of the lower limbs in sprinters and its relation with sprint performance. Subjects were 10 male sprinters and 14 controls whose anthropometric variables and isometric maximum strength were similar. The elongation (L) of the tendon and aponeurosis of vastus lateralis (VL) and medial gastrocnemius muscles (MG) during isometric knee extension and planter flexion, respectively, were determined using a real-time ultrasonic apparatus in vivo, while the subjects developed a gradually increasing torque from zero (relax) to maximal effort (MVC) within 5 s. While sprinters compared with controls showed significantly greater L above 500 N (about 50% of MVC) and higher dL/dF for VL at less than 20% of MVC during knee extension, there were no significant differences between the two groups in L and dL/dF for MG at every 10% of MVC during plantar flexion. Moreover, the average value of dL/dF above 50% of MVC, proposed as the compliance of tendon structures, did not significantly differ between sprinters and controls in either VL or MG. In a regression analysis within sprinters, the compliance of VL was negatively correlated to 100-m sprint time, r=-0.757 (P < 0.05), but that of MG was not, r=0.228 (P > 0.05). Thus the present results indicate that the elasticity of tendon structures of VL and MG at high force production levels, which might be assumed to associate with the storage and subsequent release of energy during exercises involving the stretch-shortening cycle, are similar in both sprinters and controls. For sprinters, however, the tendon structures of VL are more compliant than that for controls at low force production levels, and its elasticity at high force production levels may influence sprint performance.
The purpose of this study was to investigate the dynamics of human muscle-tendon complex (MTC) during stretch-shortening cycle exercises through in vivo observation. A total of seven male subjects performed dorsi flexion followed by plantar flexion at two different frequencies, 0.3 Hz (slow) and 1.0 Hz (fast), in a toe-standing position. The fascicle length (LF) of the medial gastrocnemius muscle during the movements was determined using a real-time ultrasonography in vivo. The LF at the switching phase from dorsi to plantar flexion was significantly shorter in the fast exercise (54.4 +/- 5.5 mm) than in the slow one (58.2 +/- 5.4 mm), suggesting that the elongation of tendon structures at that time was significantly greater in the former than in the latter. Furthermore, at the initial stage of plantar flexion during the fast movement, the LF hardly changed with a rapid shortening of tendon structures at that time. The observed relation between MTC length and force showed that the behaviour of tendon structures contributed to 20.2 and 42.5% of the total amount of work completed during plantar flexion phase in the slow and fast movements, respectively. Thus, the present results suggest that tendon structures make the dynamics of MTC more efficient during stretch-shortening cycle exercises by changing their lengths.
BACKGROUND: Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine favouring the secretion of TNFalpha and IL-8 and counteracts anti-inflammatory effects of corticosteroids. Airways inflammation is a central feature of bronchial asthma and is characterized by the accumulation of eosinophils. OBJECTIVE: The aim of this study was to investigate whether MIF is related to asthma symptoms and eosinophil accumulation in the airways. METHODS: Serum MIF levels were measured by an enzyme-linked immunosorbent assay in 44 healthy subjects and 44 asthmatics. Levels of MIF in induced sputum were measured in 10 healthy subjects and 15 asthmatics. Levels of eosinophil cationic protein (ECP) in induced sputum were measured by a radioimmunosorbent assay. Fluorescence double immunostaining was conducted to examine cellular source and localization of MIF. RESULTS: Serum MIF levels were significantly increased in asthmatic patients compared with age and sex-matched control subjects. Symptomatic patients had a higher MIF level than asymptomatic patients. Induced sputum obtained from asthmatics contained higher levels of MIF than those from control subjects. MIF levels in induced sputum were correlated with ECP levels in induced sputum. MIF was colocalized with eosinophil peroxidase staining in the cytoplasm of sputum cells. CONCLUSION: Increased MIF levels are associated with asthma symptoms and one of the cellular sources of MIF in the airways are eosinophils.
Susceptibility to asthma and other atopic diseases is known to be associated with elevated total IgE levels. Several investigators have linked the interleukin-4 (IL-4) gene and nearby markers located on chromosome 5q to elevated total IgE levels. A single nucleotide polymorphism in the IL-4 gene promoter region (C+33T) has recently been identified. As part of an effort to identify genetic variants contributing to the susceptibility to elevated total serum IgE levels, an association analysis of a newly identified promoter polymorphism (C+33T) with total serum IgE levels was conducted. The study was conducted using 240 Japanese subjects (120 asthmatics and 120 healthy controls). The IL-4 C+33T polymorphism was genotyped by PCR-restriction fragment length polymorphism analysis. The frequency of the T allele was 0.675 in asthmatic subjects and 0.671 in healthy controls. An ANOVA model adjusted for age, sex and disease status suggested a genetic association of C+33T polymorphism with elevated total serum IgE levels (P < 0.05). The data suggest that IL-4 promoter C+33T polymorphism may be one of the genetic polymorphisms that explain genetic linkage or association between elevated total serum IgE levels and markers on chromosome 5q.
The dorsal ectoderm of the limb bud is known to regulate anterior-posterior patterning as well as dorsal-ventral patterning during vertebrate limb morphogenesis. Wnt-7a, expressed in the dorsal ectoderm, encodes a key molecule implicated in these events. In the present study, chicken frizzled-10 (Fz-10) encoding a Wnt receptor was used to study mechanisms of Wnt-7a signaling during chick limb patterning, because its expression is restricted to the posterior-distal region of the dorsal limb bud. Fz-10 transcripts colocalize with Sonic hedgehog (Shh) in the dorsal side of stages 18-23 chick limb buds. It was demonstrated that Fz-10 interacts with Wnt-7a to induce synergistically the expression of Wnt-responsive genes, such as Siamois and Xnr3, in Xenopus animal cap assays. In the chick limb bud, Fz-10 expression is regulated by Shh and a signal from the dorsal ectoderm, presumably Wnt-7a, but not by signals from the apical ectodermal ridge. These results suggest that Fz-10 acts as a receptor for Wnt-7a and has a positive effect on Shh expression in the chick limb bud.
When one sees a middle-aged male smoker who presents with progressive exertional dyspnoea and irreversible airflow obstruction, the most likely clinical diagnosis is pulmonary emphysema or chronic obstructive pulmonary disease (COPD). We report a 45-year-old male smoker who was initially suspected to have such a disease but was eventually diagnosed as having idiopathic constrictive bronchiolitis by lung biopsy, clinical history, and laboratory findings. A finding on lung computed tomography of diffuse hyperinflation but few low attenuation areas and relatively well-preserved diffusing capacity of carbon monoxide seems to be the key for suspecting this rare clinical entity. The pathological difference between this bronchiolitis and small airway disease observed in COPD will be also discussed.
Ex-chromate workers are frequently afflicted with lung cancers, especially central-type squamous cell carcinomas (SCCs) of the lung. However, little is known about the molecular and cellular biologic characteristics of chromate-induced lung cancers. We investigated expression of cyclin D1, bcl-2, and p53 proteins in chromate-induced lung cancers by immunohistochemistry, compared with those in lung cancers from nonexposed individuals and those in individuals with pneumoconiosis. Of 19 chromate-induced lung cancers, 16 tumors were SCCs, including 11 central and 5 peripheral types. Eleven (69%) of 16 chromate SCCs showed cyclin D1 expression. In contrast, cyclin D1 expression was observed in only 3 (12%) of 26 SCCs from nonexposed individuals and 6 (16%) of 37 SCCs that developed in patients with pneumoconiosis, respectively. The frequency of cyclin D1 expression proved to be significantly higher in chromate-induced SCCs than in SCCs from nonexposed individuals and from those with pneumoconiosis (P < .001). When comparisons were extended to all histologic types of lung cancer, cyclin D1 expression was observed significantly more often in chromate-induced lung cancers than in lung cancers from nonexposed subjects and those from patients with pneumoconiosis (11 [58%] of 19 v 5 [10%] of 52, P < .001, and 7 [11%] of 63, P < .001, respectively). Frequencies of bcl-2 and p53 expression were not significantly different among lung cancers from ex-chromate workers, nonexposed individuals and those with pneumoconiosis. The current study suggests that cyclin D1 expression may be involved in the development of chromate-induced lung cancers, although its underlying mechanism remains to be determined.
To evaluate the role of normal flora in the nares in preventing Staphylococcus aureus colonization, we conducted a replacement study in vivo. Staphylococcus epidermidis (rate of colonization: 100%), various species of corynebacteria (52.5%) and S. aureus (25.%) were the major bacterial inhabitants in the nares of 156 healthy volunteers. The low incidence of S. aureus colonization in the carriers with corynebacteria (8.5%), compared to non-carriers (44. 5%) indicated the possibility of competition for survival between S. aureus and corynebacteria. To confirm this hypothesis, we artificially implanted a strain of Corynebacterium sp (API Coryne bioprofile; 5100304), denoted as Co304 into the nares of 17 S. aureus carriers. S. aureus was completely eradicated in 71% of carriers by up to 15 inoculations of Co304. However, similar doses of 0.9% NaCl or S. epidermidis into the nares of 10 volunteers did not eradicate S. aureus. No bacteriocin-like activity against S. aureus was detectable, even after mitomycin C stimulation of Co304. Thus Co304 interfered with S. aureus by a different mechanism to a bacteriocin-like activity.