Biomedical subjects

K Takehara

Publications and source records attributed to K Takehara.

At least 109 records · Page 6Linked to original sources

PubMed1998

Antigen specificity of antihistone antibodies in systemic sclerosis.

OBJECTIVES: The aim of the study was to determine the prevalence and clinical significance of antibodies to individual histone components in systemic sclerosis (SSc). METHODS: Serum samples from patients with limited cutaneous SSc (lSSc; n = 42) and diffuse cutaneous SSc (dSSc; n = 28) were examined for IgG and/or IgM antibodies to individual histone components and complexes by enzyme linked immunosorbent assay (ELISA). RESULTS: The level of IgG antibody to total histones was significantly higher in lSSc and dSSc than in normal controls. The level of IgM antibody to total histones was significantly higher in lSSc, but not in dSSc, than in normal controls. IgG antibody to total histones tended to be increased in dSSc when compared with that in lSSc. On the other hand, IgM antibody to total histones tended to be increased in lSSc when compared with that in dSSc. Although SSc showed various antihistone specificities, H2B, H2A-H2B, (H2A-H2B)-dsDNA were main antigens recognised by IgG antibodies in both lSSc and dSSc. Although IgM antibodies to H2B and H2A-H2B were also detected in both lSSc and dSSc, serum samples from lSSc patients exhibited highest IgM reactivity with H1. CONCLUSION: SSc may be included among conditions in which heterogeneous antihistone antibodies are produced. IgM antibodies to the most accessible histone H1 may be related to mild clinical features (lSSc) and IgG antibodies to the inner core molecules of native histone such as H2B or complexes including H2B may be associated with severe clinical features (dSSc) in Ssc.

Adult↗

PubMed1998

Polymerase chain reaction and immunohistochemistry frequently detect occult melanoma cells in regional lymph nodes of melanoma patients.

AIMS: To evaluate immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR) for melanoma associated antigens (MAA) in detecting occult melanoma cells in lymph nodes which were missed on routine pathology. METHODS: Occult melanoma cells were sought in 436 lymph nodes from 32 patients with cutaneous melanoma of the lower extremities by immunohistochemistry using the melanoma specific antibody HMB-45. The detection sensitivity of routine histology, immunohistochemistry, and RT-PCR was also compared in 23 lymph node samples from six patients. RESULTS: Immunohistochemistry showed that 15 of 24 patients (62.5%) who had no detectable metastasis by routine histology had at least one lymph node containing HMB-45 positive cells, mostly seen singly in the medullary sinus. No difference was found in known clinicopathological prognostic factors and recurrence rates between the two groups of patients with and without occult HMB-45 positive cells. RT-PCR analyses showed that the nested PCR for tyrosinase was more sensitive than a combination of single round PCR for five different MAA, including tyrosinase, MART-1/Melan A, Pmel-17, TRP-1, and TRP-2, detecting tyrosinase mRNA in six nodes which were negative by HMB-45 immunohistochemistry. CONCLUSIONS: Immunohistochemistry + RT-PCR is more sensitive than routine histology in detecting occult melanoma cells in lymph nodes. The nested PCR for tyrosinase should be used in future studies investigating the prognostic significance of such lymph node micrometastases.

Antigens, Neoplasm↗

PubMed1998

IL-13 production by peripheral blood mononuclear cells from patients with atopic dermatitis.

BACKGROUND: Interleukin 13 (IL-13) shares several functional properties with IL-4 and has been shown to be capable of inducing IgE synthesis. OBJECTIVE: To determine whether the production of IL-13 by peripheral blood mononuclear cells (PBMC) from patients with atopic dermatitis (AD) is connected with the development of AD. METHODS: We examined PBMC from 52 patients with AD and 23 healthy volunteers as controls. PBMC were cultured with or without antigen extracted either from Dermatophagoides farinae or house dust for 48 h, and then the supernatants were measured for IL-13 by competitive enzyme immunoassay. We also examined the effect of the immunosuppressant FK506 on the production of IL-13 by antigen-stimulated PBMC from AD patients. RESULTS: The levels of IL-13 produced by non-stimulated PBMC in AD were significantly higher than those in controls. The IL-13 levels in AD were increased after antigen stimulation and were higher than those in controls. Moreover, the enhanced production of IL-13 in AD was suppressed by FK506. CONCLUSION: We suggest that IL-13 may play some role in the development of AD.

Adolescent↗

PubMed1998

Pigmented dermatofibrosarcoma protuberans (Bednár tumor) occurring in a Japanese infant.

A case of pigmented dermatofibrosarcoma protuberans (Bednár tumor) occurring in a Japanese infant is reported. A 6-month-old girl developed a 16 x 10 mm erythematous tumor with a slight elevation on the lower back at 1 month of age. Histological examination revealed proliferation of spindle-shaped, fibroblast-like cells in the myxoid interstitium. Subsequently the tumor grew gradually to a red-purplish tumor measuring 45 x 36 mm. The second biopsy specimen presented hypercellular proliferation composed of spindle-shaped cells showing slight nuclear atypia and a characteristic storiform pattern, with scattered slender dendritic cells containing a large amount of brown pigment. Immunohistochemical studies of the second biopsy specimen showed that the spindle-shaped tumor cells were positive for vimentin and CD34 and negative for factor XIIIa. The number of CD34-reactive spindle-shaped tumor cells increased in the second biopsy specimen compared with the first biopsy.

Antigens, CD34↗

PubMed1998

Distribution of attenuated goose parvoviruses in Muscovy ducklings.

With a polymerase chain reaction (PCR) method, goose parvovirus (GPV) DNA was detected in Muscovy ducklings inoculated with attenuated GPV strains, IH and IHC. Strain IH that had been passed 20 times in Muscovy duck embryos could be detected in ducklings at 2- to 28-days after oral inoculation by PCR, however, a cell culture adapted strain IHC that had been passed 15 times in Muscovy duck embryos and then successively 50 times in Muscovy duck embryo fibroblasts could not be detected by 6 days postinoculation by the oral route, but via intramuscular inoculation the virus was detected from 6 dpi. With both strains Muscovy ducklings produced neutralizing antibodies against GPV, but GPV could be recovered from heart muscles even in birds that had high titer of neutralizing antibody. This means that GPV remains in birds for a long period under the presence of high titer of neutralizing antibody in the serum. Recovery of the virus was consistent with PCR results with one exception in which the bird had a neutralizing antibody titer of more than 100,000. After inoculation of these strains, no clinical signs were detected in ducklings. These results suggest that strains IH and IHC can be candidates for live attenuated vaccine for GPV infection.

Animals↗

PubMed1998

Coxiellosis in domestic and wild birds from Japan.

Serological evidence of infection with Coxiella burnetii was found in 41 (2%) of 1,951 domestic birds and in 167 (19%) of 863 wild birds from 17 and 5 prefectures in Japan, respectively, by microagglutination (MA) test. The bacteriological evidence of the infection was found in 17 (41%) of 41 domestic birds and 37 (22%) of 167 wild birds by the nested polymerase chain reaction (PCR). In addition, C. burnetii was isolated from five each of serum, spleen and fecal specimens from five jungle crows (Corvus macrorhynchos) (whose sera were positive by both the MA test and PCR) by inoculating laboratory mice. Domestic quail (Coturnix coturnix japonica) (3%), domestic muscovy ducks (Cairina moschata) (3%), domestic chickens (2%), domestic mallards (Anas platyrhynchos domesticus) (2%), carrion crows (Corvus corone) (37%), jungle crows (35%), and wild rock doves (Columba livia) (6%) showed serologic evidence of experience with C. burnetii. There was a tendency for a high prevalence among birds living and/or feeding in close proximity to infected livestock. This suggests that these birds are one of the less important links in maintaining the whole cycle of C. burnetii infection.

Agglutination Tests↗

PubMed1998

Increased production of interleukin 6 and interleukin 8 in scleroderma fibroblasts.

OBJECTIVE: To determine additional abnormal characteristics related to cytokines in fibroblasts derived from systemic sclerosis (SSc), we examined the production of interleukin 6 (IL-6) and IL-8 and their mRNA levels both in scleroderma fibroblasts and in those from normal skin. METHODS: Cultured fibroblasts from patients with SSc and healthy controls were examined. Production of IL-6 and IL-8 was assessed by specific ELISA, and the levels of IL-6 and IL-8 mRNA were determined by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Basal production of both IL-6 and IL-8 was significantly increased in scleroderma fibroblasts compared with controls. When cells were stimulated with either IL-1beta (50 pg/ml) or tumor necrosis factor-alpha (TNF-alpha: 10 ng/ml), the production of IL-6 and IL-8 was predominantly increased in both cell strains and there was no significant difference in the production of IL-6 and IL-8 between them. When normal fibroblasts were stimulated with IL-1beta for 48 h and subcultured, both IL-6 and IL-8 production were significantly increased, and production remained elevated even after 3 passages. RT-PCR revealed that IL-6 and IL-8 mRNA were detected in scleroderma fibroblasts but not in normal skin fibroblasts without cytokine stimulation. When stimulated with IL-1beta, both cell strains expressed IL-6 and IL-8 mRNA to almost the same extent. CONCLUSION: Increased production of IL-6 and IL-8 by scleroderma fibroblasts suggests that these cells may have been stimulated by certain cytokines in vivo.

Cells, Cultured↗

PubMed1998

Serum levels of interleukin 6 (IL-6), oncostatin M, soluble IL-6 receptor, and soluble gp130 in patients with systemic sclerosis.

OBJECTIVE: To determine whether serum interleukin 6 (IL-6), oncostatin M (OSM), soluble IL-6 receptor (sIL-6R), and soluble gp130 (sgp130) levels in patients with systemic sclerosis (SSc) are elevated and whether they are correlated with the clinical or serological features of the disease. METHODS: Serum samples from patients with SSc (n = 55) and control subjects (n = 20) were investigated by ELISA. Patients were divided into 4 groups: 12 with limited cutaneous SSc (lSSc) < or = 3 years' duration (early lSSc), 22 with lSSc > 3 years' duration (late lSSc), 9 with diffuse cutaneous SSc (dSSc) < or = 3 years' duration (early dSSc), and 12 with dSSc > 3 years' duration (late dSSc). RESULTS: Serum IL-6 levels were significantly elevated in patients with early dSSc compared with controls. In addition, serum IL-6 was detected more frequently in patients with pulmonary fibrosis, and these values were inversely correlated with the percentage of vital capacity of individual patients. Furthermore, serum IL-6 levels were correlated with erythrocyte sedimentation rates, C-reactive protein, and IgG and IgA levels in patients. Serum sIL-6R levels were significantly higher in patients with lSSc versus controls. Serum OSM and sgp130 levels were not significantly elevated in patients with SSc compared with controls. CONCLUSION: We suggest that IL-6 and sIL-6R may contribute to the disease process in SSc. In particular, IL-6 may be related to the early phase of the disease and the development of pulmonary fibrosis in SSc.

Adolescent↗

PubMed1998

Increased plasma granulocyte elastase levels in Behçet's disease.

OBJECTIVE: To assess the role of granulocyte elastase in the development of thromboembolic vasculopathy in patients with Behçet's disease. METHODS: Plasma granulocyte elastase-alpha1-proteinase inhibitor (E-PI) complex levels were measured by ELISA in 11 healthy subjects and 19 patients with Behçet's disease (BD). Eight of 19 patients showed deep vein thrombosis on (99m)technetium-macro-agglutinate albumin venography. Hemostatic variables were measured at the same time. RESULTS: The mean plasma E-PI complex level was significantly higher in the 8 patients with than in the 11 patients without deep vein thrombosis (242 +/- 73 vs 165 +/- 97 ng/ml; p = 0.033). The mean plasma E-PI complex level in the 11 patients without deep vein thrombosis was significantly higher than in controls (165 +/- 97 vs 96 +/- 40 ng/ml; p = 0.038). Plasma E-PI complex levels correlated with the serum plasmin-alpha2-plasmin inhibitor complex levels (r = 0.621, p = 0.0084). CONCLUSION: Plasma E-PI complex levels appear to be a useful marker of thromboembolic vasculopathy in BD.

Antifibrinolytic Agents↗

PubMed1998

Autoantibodies against calpastatin in sera from patients with systemic sclerosis.

OBJECTIVE: To determine the prevalence and clinical correlation of anti-calpastatin antibodies in patients with systemic sclerosis (SSc). METHODS: Serum samples from patients with limited cutaneous SSc (lSSc; n=36), diffuse cutaneous SSc (dSSc; n=27), and healthy control subjects (n=29) were examined by an ELISA using human recombinant calpastatin as antigens. RESULTS: IgG anti-calpastatin antibodies were positive in 15 (24%) of 63 patients with SSc, which was similar to the frequency of IgM anti-calpastatin antibody positivity (14/63, 22%). The presence of anticentromere antibodies was associated with the presence of IgG and/or IgM anti-calpastatin antibodies. The patients with SSc positive for IgG anti-calpastatin antibodies had significantly higher erythrocyte sedimentation rates (ESR) compared with those negative for IgG anti-calpastatin antibodies. Furthermore, the levels of IgG anti-calpastatin antibodies correlated positively with the levels of ESR. The patients with dSSc positive for IgM anti-calpastatin antibodies had significantly higher frequency of inflammatory joint and muscle involvement compared with those negative for IgM anti-calpastatin antibodies. Four (80%) of 5 patients with dSSc with both joint and muscle involvement produced IgM anti-calpastatin antibodies. CONCLUSION: The presence of anti-calpastatin antibodies may be a clue to mechanisms of the inflammatory change occurring in SSc. Furthermore, the presence of anti-calpastatin antibodies could be a novel and useful serologic tool for recognizing patients with dSSc with inflammatory joint and muscle involvement.

Adolescent↗

PubMed1997

Induction of subcutaneous tissue fibrosis in newborn mice by transforming growth factor beta--simultaneous application with basic fibroblast growth factor causes persistent fibrosis.

To establish an appropriate animal model of skin fibrosis by exogenous application of growth factors, we investigated the in vivo effects of transforming growth factor-beta by injection into subcutaneous tissue of newborn mice. Histological examination revealed that TGF-beta1, beta2, and beta3 induced granulation tissue formation after 3 days of injection, while these changes had disappeared after 7 days. The changes after 3 days of injection were more pronounced in the tissue injected with TGF-beta2 or beta3 than that with TGF-beta1. In situ hybridization analysis indicated that connective tissue growth factor mRNA was strongly expressed in the fibroblasts at the site of TGF-beta injection, which suggested that fibroblasts were activated by TGF-beta. Next, we investigated the cooperative effects of TGF-beta and other growth factors including basic fibroblast growth factor (bFGF). The simultaneous application of TGF-beta and bFGF caused apparent tissue fibrosis which persisted for at least 2 weeks, while bFGF alone caused slight fibrotic changes after 7 days of injection. Thus, we succeeded in establishing an animal model of skin fibrotic disorders by the exogenous addition of growth factors, and this animal will be useful for future studies in this area.

Animals↗

PubMed1997

Induction of subcutaneous tissue fibrosis in newborn mice by transforming growth factor beta-simultaneous application with basic fibroblast growth factor causes persistent fibrosis.

Animals↗

PubMed1997

Failure of the nitric oxide synthase inhibitor to stimulate duodenal bicarbonate secretion in streptozotocin-diabetic rats.

We examined the HCO(3)- stimulatory effects of L-NAME (N(G)-nitro-L-arginine methyl ester) in the proximal duodenum of streptozotocin (STZ)-induced diabetic rats and compared with those of 16,16-dimethyl prostaglandin E2 (dmPGE2) and vagal electrical stimulation. Male SD rats were given STZ (70 mg/kg) i.p., and the experiments were done using 1 approximately 6 week STZ-diabetic rats with blood glucose levels of >300 mg/dl. Under urethane anesthesia the HCO(3)- secretion was measured in the proximal duodenal loop using a pH-stat method and by adding 10 mM HCl. Hyperglycemic conditions appeared 1 week after STZ treatment and remained during 6 week-test period. The duodenal HCO(3)- secretory response to L-NAME was significantly decreased in STZ-diabetic rats; the degree of reduction was dependent on the duration of diabetes, and the stimulatory effect disappeared completely in rats after 5 approximately 6 weeks of diabetes. Intravenous administration of L-NAME markedly increased arterial blood pressure with significant decrease in heart rate in normal rats, whereas in STZ-diabetic rats this agent caused only pressor response without any effect on heart rate. STZ-diabetic rats also secreted significantly less amount of HCO(3)- from the duodenum in response to dmPGE2 and vagal electrical stimulation after 5 approximately 6 weeks of diabetes. These all changes observed in STZ-diabetic rats were significantly reversed by daily injection of insulin. These results suggest that 1) L-NAME failed to stimulate duodenal HCO(3)- secretion in STZ-diabetic rats, and 2) impairment of the duodenal HCO(3)- secretory ability in STZ-diabetic conditions is due to both vagal-dependent neuronal dysfunction and decreased sensitivity of the secreting cell.

16,16-Dimethylprostaglandin E2↗

PubMed1997

Nonscarring inflammatory epidermolysis bullosa acquisita with esophageal involvement and linear IgG deposits.

A 24-year-old woman with autoimmune thrombocytopenia and hypothyroidism had an inflammatory bullous eruption in the mouth, face, and trunk that left no milia or scars after healing. Histologic examination revealed a subepidermal bulla and a neutrophil infiltration. Direct immunofluorescence examination showed deposition of IgG and C3 in the basement membrane zone (BMZ). Indirect immunofluorescence examination with 1M sodium chloride-split skin showed IgG binding to the dermal side. Immunoblot analysis demonstrated IgG autoantibodies reacting with 290 kD dermal protein. We diagnosed this as epidermolysis bullosa acquisita (EBA) with a nonscarring inflammatory feature. Treatment with oral dapsone, 75 mg, and prednisolone, 20 mg, cleared the eruption. Reduction of the prednisolone dosage was associated with multiple erosions in the esophagus. Direct immunofluorescence examination revealed linear deposition of IgG in the esophageal BMZ. To our knowledge, this is the first report of EBA with esophageal involvement and deposition of IgG in the BMZ of the esophagus.

Adult↗

PubMed1997

Tape stripping induces marked epidermal proliferation and altered TGF-alpha expression in non-lesional psoriatic skin.

Psoriasis is a chronic inflammatory disorder characterized by epidermal hyperproliferation. Although recent evidence suggests that T cell activation is a primary trigger for psoriasis lesions, there may be alterations in the keratinocyte growth regulatory pathways which induce epidermal hyperproliferation in psoriatic patients. To test this hypothesis, we investigated the proliferative activity of epidermal keratinocytes 48 h after tape stripping, one of the standard mechanical ways to stimulate the epidermis, in 20 psoriasis patients and in 18 controls. Epidermal cell kinetics were assessed with DNA flow cytometry, the mitotic index, bromodeoxyuridine incorporation, Ki-67 antigen expression and DNA polymerase alpha expression. The expression of TGF-alpha and EGF receptors, critical mediators of keratinocyte proliferation, were also investigated immunohistochemically. The results of multiparameter assays showed that the baseline proliferative activity in uninvolved skin was the same in psoriasis patients and normal controls. After tape stripping, although both psoriasis patients and the normal controls showed significant increases in epidermal cell proliferation, the values of all the parameters investigated were significantly greater in the psoriasis patients than in the normal controls. EGF receptors were overexpressed in basal and suprabasal keratinocytes after tape stripping in both the psoriasis patients and the normal controls. In contrast, overexpression of TGF-alpha was only observed in the patients with psoriasis, which may explain their increased proliferative response to trauma.

Adult↗

PubMed1997

Prediction of effect of interferon on chronic hepatitis C.

Clinical, pathological, and virological analysis including hypervariable region-1 of hepatitis C virus (HCV) was performed to predict the effect of interferon (IFN) on 41 patients with chronic hepatitis type C. The low virus load, low frequency of the mutation in the hypervariable region-1 as the change of amino acid and high level of serum aminotransferase make one estimate the good effect of IFN on patients with HCV. Mutation in the hypervariable region-1 of HCV measured by fast assay fluorescence single-stranded conformational polymorphism was more frequent in nonresponders to IFN than responders. The most frequently mutated position was amino acid number 406. This indicates that the specific mutation site might affect the response of IFN.

Amino Acid Sequence↗

PubMed1997

Tumour cells of extramammary Paget's disease do not show either p53 mutation or allelic loss at several selected loci implicated in other cancers.

Extramammary Paget's disease is a particular form of skin cancer of unknown histogenesis. To look for the genetic defects underlying the pathogenesis of this tumour, we have examined loss of heterozygosity (LOH), p53 and human papillomavirus (HPV) status, and the expression of c-erbB-2 and bcl-2 proteins in 14 cases. Unexpectedly, no LOH was detected at several loci commonly lost in other human cancers (namely 3p, 9p, 9q, 13q, 16q, 17p, and 17q) in 12 tumours examined. Altered p53 protein expression was entirely or mostly negative in all 14 cases. Direct sequencing of exons 5-8 of the p53 gene in eight cases revealed no mutation. Polymerase chain reaction amplification of the L1 gene of human papillomavirus (HPV) did not detect the virus that could inactivate p53 and retinoblastoma tumour-suppressor gene products. As expected, c-erbB-2 proto-oncogene protein was overexpressed in six cases. The expression of bcl-2 was negative in all cases. The results presented in this study suggest that molecular events underlying extramammary Paget's disease differ from those of other common epithelial malignancies and that tumour-suppressor genes located in chromosome regions not examined in this study may be important.

Aged↗

PubMed1997

Alterations in duodenal bicarbonate secretion and mucosal susceptibility to acid in diabetic rats.

BACKGROUND & AIMS: The gastroduodenal mucosal susceptibility to ulcerogenic stimuli increases in diabetic conditions, but the mechanism is unknown. The aim of this study was to investigate alterations in duodenal HCO3- secretory response in diabetic animals. METHODS: The experiments were performed in rats treated with streptozotocin (70 mg/kg intraperitoneally) after 1-6 weeks of diabetes, when blood glucose levels were > 300 mg/dL. HCO3 secretion was measured in the proximal duodenal loop of rats that were under urethane anesthesia using a pH-stat method. RESULTS: The duodenal HCO3 secretion induced by mucosal acidification was decreased in streptozotocin-treated rats depending on the duration of diabetes. The HCO3 secretion was also decreased in response to 16,16-dimethyl prostaglandin E2, vasoactive intestinal polypeptide, or vagal electrical stimulation. Acid load in the duodenum produced extensive damage in 5-6-week diabetic rats, although the same treatment caused only slight damage in the normal rat duodenum. Such alterations in the duodenal HCO3 secretory and ulcerogenic responses in diabetic rats were partially restored by daily injection of insulin. CONCLUSIONS: The results suggest that streptozotocin-diabetic conditions impair the duodenal HCO3- secretion in rats, possibly as a result of decreased sensitivity of the epithelial cell and dysfunction of neuronal pathway, thereby increasing the mucosal susceptibility to acid injury in the duodenum.

Animals↗