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Biomedical subjects

K Yamane

Publications and source records attributed to K Yamane.

At least 19 recordsLinked to original sources
PubMed2006

The expression levels and the differential expression of transforming growth factor-beta receptors in dermatofibroma and dermatofibrosarcoma protuberans.

BACKGROUND: Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) are benign and intermediate malignant fibrotic dermal tumours, respectively. The contribution of transforming growth factor (TGF)-beta has been implicated in the progression of sclerosis in fibrotic diseases. OBJECTIVES: To investigate the expression of TGF-beta receptors in these fibrotic tumours. METHODS: We examined the expression levels of TGF-beta type I and type II receptors (TGFbeta-RI and TGFbeta-RII) in DF and DFSP using in situ hybridization and immunohistochemical analysis. We also examined the expression of TGF-beta1 and collagen type I using immunohistochemical analysis. RESULTS: We detected strong expression of TGFbeta-RI and TGFbeta-RII on epidermis and epidermal appendages, moderate expression in vascular endothelial cells, smooth muscle cells and neural tissues, and weak expression in fibroblasts in normal skin sections. The expression levels of TGFbeta-RI and TGFbeta-RII were elevated in the tissue sections of DF in comparison with normal dermal sections using in situ hybridization and immunohistochemical staining. Furthermore, the expression of TGFbeta-RI and TGFbeta-RII was strong in spindle-shaped cells around DF. The expression of TGFbeta-RI and TGFbeta-RII was decreased in DFSP in comparison with DF, and their expression was found to be homogeneous in each DFSP tumour cell. The staining for TGF-beta1 was found prominently on matrix and spindle-shaped tumour cells of DF, and peripheral regions of DFSP. Weak expression of TGF-beta1 was found on normal skin or tumour cells in the central part of DFSP. Type I collagen expression was found on spindle-shaped tumour cells in DF, but not in tumour cells of DFSP. CONCLUSIONS: These results suggest the possibility that TGF-beta signalling may contribute to the fibrosis around DF, and that TGF-beta receptors may play important roles in TGF-beta signalling. The expression patterns of TGFbeta-RI and TGFbeta-RII may be helpful in distinguishing these diseases.

Activin Receptors, Type I↗
PubMed2005

Constitutively phosphorylated Smad3 interacts with Sp1 and p300 in scleroderma fibroblasts.

OBJECTIVE: To elucidate the role of transforming growth factor-beta (TGF-beta)/Smad signalling in the increased expression of the collagen gene in systemic sclerosis (SSc) fibroblasts. METHODS: Dermal fibroblasts from seven patients with diffuse SSc of recent onset and from seven healthy individuals were studied. The expression levels of Smad2, Smad3 and Smad4 proteins were determined by immunoblotting. Smad3 phosphorylation and the interaction of Smad3 with Sp1 or p300 were analysed using immunoprecipitation. The effects of overexpression of Smad proteins or Sp1 on the human alpha2(I) collagen gene transcription were investigated with chloramphenicol acetyltransferase (CAT) assays using the -772 COL1A2/CAT construct. RESULTS: Constitutive increased Smad3 phosphorylation was detected in SSc fibroblasts compared with normal fibroblasts. Increased interaction of Smad3 with Sp1 as well as p300 was also detected in SSc fibroblasts. The overexpression of Smad3 caused an increase of up to 5-fold in COL1A2 promoter activity in normal fibroblasts, while Smad3 caused a small increase in COL1A2 promoter activity in SSc fibroblasts. However, neither Smad2 nor Smad4 caused significant effects in COL1A2 promoter activity in normal fibroblasts or SSc fibroblasts. The overexpression of Sp1 caused further increase in COL1A2 promoter activity stimulated by TGF-beta in normal fibroblasts, but did not change COL1A2 promoter activity in the presence of TGF-beta in SSc fibroblasts. The combined overexpression of Smad3 and Sp1 significantly enhanced TGF-beta response in normal fibroblasts, but less markedly in SSc fibroblasts. CONCLUSIONS: These results suggested that SSc fibroblasts are less sensitive to exogenous TGF-beta stimulation because they are already activated by the autocrine TGF-beta loop.

Cells, Cultured↗
PubMed2005

Evaluating the effects of spatial frequency on migraines by using pattern-reversal visual evoked potentials.

OBJECTIVE: To clarify the effects of contrast and spatial frequency in patients with migraine by means of pattern-reversal visual evoked potentials (PVEPs). METHODS: PVEPs were obtained from 14 patients who had migraine without aura (MO), 11 patients who had migraine with aura (MA), and 25 age-matched, healthy controls (CO). PVEPs were binocularly recorded with a reversal rate of 1Hz (2 reversal/s) at 3 spatial frequencies (0.5, 1.0 and 4.0 cpd) at high (98%), medium (83%) and low (29%) contrast. N75, P100 and N135 latency and the amplitudes of P50-N75, N75-P100 and P100-N135 were analyzed. RESULTS: Increased amplitude of PVEPs in patients with migraines were revealed at 3 different spatial frequencies in all components. The MO and the MA showed increased amplitudes mostly in high contrasts (98%). These findings were detected more at a high spatial frequency (4.0 cpd) than at a low spatial frequency (0.5 cpd). Increased amplitude with prolonged latency of N135 were found both in MO and MA at 4.0 cpd. CONCLUSIONS: We conclude that pattern stimuli of high contrasts may be particularly effective in uncovering abnormal cortical reactivity which may be modified in the primary and secondary visual cortex in the interictal state of migraine. SIGNIFICANCE: These findings indicate that there is abnormal visual cortex processing in patients with migraine.

Adult↗
PubMed2005

Sclerosing panniculitis is associated with pulmonary hypertension in systemic sclerosis.

BACKGROUND: There have been no reports of patients with sclerosing panniculitis and systemic sclerosis (SSc). OBJECTIVES: To evaluate the incidence of sclerosing panniculitis in patients with SSc, and to investigate the clinical features of such cases. METHODS: In total, 128 patients with SSc treated at our clinic were investigated retrospectively. RESULTS: SSc patients with sclerosing panniculitis had pulmonary hypertension (PH), especially isolated PH, at a significantly higher incidence than those without. Among the SSc patients with PH, those with sclerosing panniculitis had pulmonary infarctions at a higher incidence than those without. CONCLUSIONS: Our results suggest that thrombosis caused by venous hypertension of the leg may be the main cause of PH in patients with SSc and sclerosing panniculitis. Sclerosing panniculitis may be a useful marker of PH in patients with SSc.

Adult↗
PubMed2005

Rheumatoid factor isotypes in localized scleroderma.

Localized scleroderma is a connective tissue disorder that is sometimes accompanied by various immunological abnormalities. In this study, we analysed serum levels of rheumatoid factor (RF) isotypes in patients with localized scleroderma and in normal controls to determine if any of these isotypes reflect the severity of the disease. IgM RF, IgG RF and IgA RF were positive in 30%, 21%, and 7% of the patients, respectively. The levels of IgM RF were significantly higher in the patients with generalized morphea (GM), the most severe form of localized scleroderma, than those with linear scleroderma (LS) (P < 0.005) or normal controls (P < 0.0005). The levels of IgG RF were significantly higher in patients with GM than normal controls (P < 0.05). The levels of IgA RF were significantly higher in patients with GM or LS than normal controls (P < 0.001 and P < 0.01, respectively). The count of sclerotic lesions was significantly higher in patients with IgM RF than those without (P < 0.05). These results suggest that the presence of RF isotypes is one of the immunological abnormalities of localized scleroderma. IgM RF seemed to be most useful of these three factors to determine the severity of disease.

Adolescent↗
PubMed2005

A novel exopolysaccharide from a clinical isolate of Prevotella nigrescens: purification, chemical characterization and possible role in modifying human leukocyte phagocytosis.

Prevotella nigrescens, a gram-negative black-pigmented anaerobic rod, has frequently been isolated from periodontitis and periapical periodontitis lesions. We have isolated an exopolysaccharide-producing P. nigrescens, strain 22, from a chronic periodontitis lesion. The purpose of this study was to determine the chemical composition and function of the exopolysaccharide associated with this clinical isolate. The chemical composition and structure of the purified exopolysaccharide from strain 22 were determined by high performance liquid chromatography and methylation analysis. To define the biological function of this exopolysaccharide, a chemically induced exopolysaccharide nonproducing mutant, strain 328, which was derived from strain 22, was established. The biological effects of exopolysaccharide were determined by comparing the ability of strain 22, strain 328 or heat-killed strain 22 to form abscesses in mice and to interfere with the phagocytic activity of peripheral blood polymorphonuclear leukocytes. Chemical analysis showed that isolated exopolysaccharide consisted of mannose (521.6 microg/mg), glucose (25.6 microg/mg), fructose (65.8 microg/mg), galactose (12.5 microg/mg), arabinose (6.2 microg/mg), xylose (3.2 microg/mg), rhamnose (6.1 microg/mg), and ribose (0.6 microg/mg). Methylation analysis of exopolysaccharide indicated that the linkages of mannose were primarily (1-->2, 1-->6) (1-->2) (1-->6), and (1-->3). Strain 22 and, to a lesser extent, its heat-killed counterpart induced greater abscess formation in mice than strain 328, even though the enzymatic profile of strain 22 was similar to that of strain 328. The ability of strain 328 to induce abscess formation was restored by adding the purified exopolysaccharide isolated from strain 22 to the cell suspension of strain 328. Exopolysaccharide alone failed to induce abscess formation in mice. Further, strain 328 but not the untreated or heat-killed strain 22, was phagocytosed by polymorphonuclear leukocytes both in the presence and in the absence of opsonic factors. The results suggest that these polysaccharides isolated from strain 22, which primarily consisted of mannose, may play a key role in the development of the chronic inflammatory lesion from which this strain was isolated.

Abscess↗
PubMed2005

Drug-induced hypersensitivity syndrome associated with transient hypogammaglobulinaemia and increase in serum IgE level.

Drug-induced hypersensitivity syndrome (DIHS) is a rare but severe disease with multiorgan failure. Recently, the association of the human herpesvirus (HHV) family, particularly of HHV-6, with DIHS has been reported. We report a 43-year-old female diagnosed as having DIHS based on the clinical course and laboratory examinations. The HHV-6 reactivation was demonstrated by significantly increased levels of the specific antibody in her paired sera and by polymerase chain reaction of HHV-6 DNA. Notably, transient hypogammaglobulinaemia was detected in the early stage of the disease, which was associated with the disease activity. By contrast, the serum IgE level and eosinophils were increased 2 or 3 weeks later. In addition, serum levels of interferon gamma, interleukin (IL)-4 and soluble IL-2 receptor, which were increased in the early phase of the disease, decreased gradually after the corticosteroid therapy.

Adult↗
PubMed2004

Effect of relative humidity on the photocatalytic activity of titanium dioxide and photostability of famotidine.

Titanium dioxide (TiO2) has been widely used as a pharmaceutical excipient and is also known to be a strong photocatalyst. An investigation into the relationship between the photocatalytic activity of TiO2 and the photostability of famotidine, which is known as an H2-blocker, is presented. The photocatalytic activity of the anatase form of TiO2, as measured by the four-probe method, is approximately 1.5 times higher than that of the rutile form. Discoloration of famotidine in a binary system containing TiO2 depends significantly on both the wavelength of the irradiating light and the crystal form of the TiO2, with the degree of discoloration of anatase higher than that of the rutile form. Discoloration of famotidine also depends on relative humidity. The relationship between discoloration rate constant and water vapor pressure is linear. These results demonstrate that famotidine is easily discolored by the photocatalytic activity of TiO2 and suggest that the solid-state photocatalytic activity of TiO2 is strongly affected by relative humidity.

Catalysis↗
PubMed2004

A comparison between Japanese-Americans living in Hawaii and Los Angeles and native Japanese: the impact of lifestyle westernization on diabetes mellitus.

We have been conducting the Hawaii-Los Angeles-Hiroshima Study since 1970, mainly to determine the effects of environmental changes on various diseases by comparing Japanese-Americans with native Japanese subjects. Japanese-Americans living in Hawaii and Los Angeles are originated mainly from Hiroshima, Japan and are genetically identical with native Japanese. Through this study, we made several clear observations about Japanese-Americans. First, Japanese-Americans were highly exposed to a westernized lifestyle ; in other words, a relatively high fat and simple carbohydrate diet with low physical activity as compared to native Japanese. Second, the prevalence of type 2 diabetes among Japanese-Americans and death from ischemic heart disease among Japanese-American diabetic patients were higher. Third, the serum fasting insulin level as well as the insulin level after a glucose load, was higher among Japanese-Americans, even when the serum glucose levels were not statistically different as compared to native Japanese. Accordingly, Japanese-Americans were thought to have a high insulin resistance status. However, the initial insulin response after a glucose load was low, which was more similar to Japanese people than to Caucasians. Fourth, the total cholesterol and triglyceride levels were higher among Japanese-Americans. These results are supposed to be derived from the insulin resistant status by the westernization of lifestyle, as well as from the weakness of pancreatic beta cell function that is supposed to be genetically regulated among Japanese. In conclusion, it appears that for genetically Japanese people, environmental factors are important for the development of metabolic diseases such as diabetes mellitus and cardiovascular disease.

Adult↗
PubMed2004

Characteristics and surgical outcomes of paediatric retinal detachment.

PURPOSE: To report the clinical features and surgical and visual outcomes of rhegmatogenous retinal detachment (RRD) in the paediatric population. METHODS: A retrospective review of children (aged 0-15 years) who underwent primary surgical repair for RRD at the Hiroshima University Hospital between 1988 and 2001. RESULTS: In all 53 eyes of 49 patients were identified; paediatric RRD accounted for 3.1% of 1779 eyes with RRD operated on during this period. The causes of RRD included blunt trauma (27%), myopia (25%), idiopathic (20%), familial exudative vitreoretinopathy (13%), and others. Among 55 eyes, 12 (22%) already had proliferative vitreoretinopathy (PVR) of grade C or D preoperatively. The median initial visual acuity (VA) was 0.3. Retinal reattachment was achieved with a single operation in 78%. Final retinal reattachment was achieved in 87%. Retinal reattachment rates with and without PVR were 42% and 100%, respectively (P<0.01). Median final VA was 0.7. Final VA was > or =0.1 in 73% and > or =0.5 in 53%; four eyes had a final VA of no light perception. The presence of preoperative PVR (P=0.03) and the initial VA (P<0.0001) significantly affected final VA. CONCLUSIONS: Paediatric RRD is characterised by a delay in diagnosis, as evidenced by the high rate of PVR at presentation. Retinal reattachment was adversely affected by the presence of PVR. Final VA correlated with the initial VA and was significantly affected by preoperative PVR. Early diagnosis may improve the visual prognosis of paediatric retinal detachment.

Adolescent↗
PubMed2004

Erectile dysfunction is strongly linked with decreased libido in diabetic men.

Erectile dysfunction frequently occurs with diabetes mellitus. A survey of diabetic men was conducted by anonymous questionnaire to investigate the associations of erectile dysfunction with various predictive factors. A total of 112 diabetic males without an obvious history of erectile dysfunction were available for analyses. The mean age and duration of diabetes were 53.7 +/- 12.2 years and 10.2 +/- 8.6 years (mean +/- standard deviation), respectively. The questionnaire included questions on the presence or absence of smoking, hypertension, libido and subjective symptoms of diabetic neuropathy that may be associated with erectile dysfunction. Analysis of the answers to the questionnaire revealed that 40% of the patients complained of erectile dysfunction (erection 'always insufficient'). Erectile dysfunction was significantly correlated with age (p = 0.005), but not with duration of diabetes (p = 0.25), adjusted for age. Erectile dysfunction was also associated with sensory neuropathy and reduced libido, independently of age. The logistic regression analysis revealed that erectile dysfunction was positively associated with reduced libido and age. The odds ratio of erectile dysfunction for reduced compared to unreduced libido was 18.21, suggesting that psychogenic factors have a marked influence on erectile dysfunction. It is concluded that the presence of erectile dysfunction should be considered when symptoms related to diabetic neuropathy are observed; psychological approaches, such as sexual counseling, could be applied for the treatment of erectile dysfunction.

Adult↗
PubMed2004

Serum levels of tissue inhibitor of metalloproteinase-1 and 2 in patients with eosinophilic fasciitis.

BACKGROUND: Serum levels of tissue inhibitor of metalloproteinases (TIMPs) have been reported to be elevated in patients with various connective tissue diseases. However, there has been no report that evaluates TIMPs in patients with eosinophilic fasciitis (EF). OBJECTIVES: To determine serum TIMP-1 and TIMP-2 levels in patients with EF and to investigate their clinical significance. METHODS: Immunohistochemical stainings were performed in normal and EF skin samples. Serum TIMP-1 and TIMP-2 levels of 11 patients with EF and 12 healthy individuals were also measured with specific enzyme-linked immunosorbent assays. RESULTS: The fascia of EF patients was stained only by TIMP-1. Serum TIMP-1 levels (mean +/- SD) were significantly higher in EF patients than in healthy individuals (206.3 +/- 65.4 vs. 145.2 +/- 36.2 ng mL(-1), P < 0.01). Serum TIMP-1 levels in EF patients were significantly correlated with serum gamma-globulin and IgG levels (r = 0.86, P < 0.05; r = 0.83, P < 0.005, respectively). CONCLUSIONS: These results suggest that TIMP-1 is involved in the pathogenesis of EF, and that TIMP-1 may be a useful marker for the disease activity as well as serum gamma-globulin or IgG levels.

Adrenal Cortex Hormones↗
PubMed2004

Rheumatoid factor isotypes and anti-agalactosyl IgG antibodies in systemic sclerosis.

BACKGROUND: Rheumatoid factor isotypes and anti-agalactosyl IgG antibodies (anti-AG IgG) have been reported to be detected and correlated with the disease activity in some collagen diseases. OBJECTIVES: To study the frequency and the clinical significance of IgM, IgG and IgA rheumatoid factor (IgM-RF, IgG-RF and IgA-RF) and anti-AG IgG in patients with systemic sclerosis (SSc). METHODS: Seventy-nine serum samples from patients with SSc were examined by specific enzyme-linked immunosorbent assays. RESULTS: The levels of IgM-, IgG-, IgA-RF and anti-AG IgG were significantly higher in SSc patients than in normal healthy controls. The levels of IgM- and IgA-RF were significantly higher in patients with diffuse cutaneous SSc than in those with limited cutaneous SSc. IgM-, IgG- and IgA-RF and anti-AG IgG were significantly elevated in 39%, 32%, 23% and 35% of 79 SSc patients, respectively. The prevalence of pulmonary fibrosis, oesophageal involvement and cutaneous telangectasias in patients with elevated IgA-RF levels was significantly higher than in those with normal levels. The incidence of pitting scars of digits in those with elevated IgG-RF levels and the incidence of contracture of phalanges in those with elevated IgM-RF levels were significantly higher than in those with normal levels. The frequency of increased erythrocyte sedimentation rate in patients with elevated IgG-RF and the frequency of increased C-reactive protein in those with elevated IgM-RF were significantly greater than in those with normal levels. CONCLUSIONS: IgM-, IgG-, IgA-RF and anti-AG IgG can be serum indicators of specific clinical manifestations in SSc patients.

Adult↗
PubMed2004

The effect of polymorphism in the intestinal fatty acid-binding protein 2 gene on fat metabolism is associated with gender and obesity amongst non-diabetic Japanese-Americans.

AIM: The role of the codon 54 polymorphism of the fatty acid-binding protein 2 (FABP2) gene on fat metabolism has been controversial. Assuming that the effects of the polymorphism were modulated by gender and obesity which were related to lipid and glucose metabolism, we investigated this polymorphism and its effect on fat metabolism according to such factors. METHODS: Subjects were Japanese-Americans (123 men and 126 women) who were diagnosed as non-diabetic by a 75 g oral glucose tolerance test at the baseline. RESULTS: During approximately 7.8 years, 49 (24 men and 25 women) were diagnosed with type 2 diabetes. In a Cox proportional hazards model, this polymorphism was not a significant variable in the incidence of diabetes in either gender. Amongst non-obese men with the Thr54 allele, there was a significant elevation of triglycerides (TGs) (p=0.033) compared with alanine (Ala) homozygotes. Women with the Thr54 allele had significantly elevated total cholesterol (p=0.033) and low-density lipoprotein-cholesterol (LDL-C) (p=0.023) compared with Ala54 homozygotes. CONCLUSIONS: These results therefore suggested that the effects of the FABP2 polymorphism on TG, LDL-C and body mass index were associated with gender difference and obesity amongst non-diabetic Japanese-American subjects.

Aged↗
PubMed2004

Post-challenge hyperglycaemia is an independent risk factor for arterial stiffness in Japanese men.

AIMS: Arterial stiffness is an independent predictor of cardiovascular disease, but the impact of post-challenge hyperglycaemia on arterial stiffness is unknown. To investigate the association between arterial stiffness and post-challenge hyperglycaemia, we measured the second derivative of photoplethysmogram as an indicator of arterial stiffness. METHODS: This study was done in 159 asymptomatic Japanese men aged 50.7 +/- 13.0 years. All subjects underwent a 75-g oral glucose tolerance test and measurement of the second derivative of photoplethysmogram. RESULTS: According to the World Health Organization criteria (1998), 110 subjects had normal glucose tolerance, 10 had impaired fasting glucose, 30 had impaired glucose tolerance, and nine had diabetes. The b/a ratio (an index of arterial stiffness) showed a significant relationship with age (r = 0.58, P < 0.0001), height (r = -0.33, P < 0.0001), 2-h post-challenge glucose (r = 0.32, P < 0.0001), systolic blood pressure (r = 0.22, P = 0.006), and diastolic blood pressure (r = 0.21, P = 0.009). After adjustment for age and height, there were significant correlations between the b/a ratio and diastolic blood pressure (r = 0.18, P = 0.02), fasting glucose (r = 0.16, P = 0.049), and 2-h post-challenge glucose (r = 0.21, P = 0.009). Stepwise multiple regression analysis showed that only age (beta= 0.006, SE = 0.0007, P < 0.001) and 2-h post-challenge glucose (beta = 0.0005, SE = 0.0002, P < 0.05) contributed significantly to the b/a ratio (adjusted R(2) = 0.38). CONCLUSIONS: These results indicate that post-challenge hyperglycaemia is an independent risk factor for arterial stiffness.

Age Factors↗