Biomedical subjects

T Umeda

Publications and source records attributed to T Umeda.

At least 55 records · Page 3Linked to original sources

PubMed2000

Triterpenoid saponins from the roots of tea plant (Camellia sinensis var. assamica).

Three olean-12-ene type triterpenoid saponins, named TR-saponins A, B and C, were isolated as methyl esters from tea roots (Camellia sinesis var. assamica) after treatment with diazomethane. Their structures were established as the methyl esters of 3-O-alpha-L-arabinopyranosyl (1-->3)-beta-D-glucuronopyranosyl-21, 22-di-O-angeloyl-R1-barrigenol-23-oic acid, 3-O-alpha-L-arabinopyranosyl (1-->3)-beta-D-glucuronopyranosyl-21-O-angeloyl-22-O-2-me thylbutanoyl-R1- barrigenol-23-oic acid and 3-O-alpha-L-arabinopyranosyl (1-->3)-beta-D-glucuronopyranosyl-16 alpha-O-acetyl-21-O-angeloyl-22-O-2-methylbutanoyl-R1-bar rigenol-23-oic acid, by extensive 1D and 2D-NMR as well as FABMS and HR-MS analyses.

Magnetic Resonance Spectroscopy↗

PubMed2000

Effect of decaglycerol monooleate on phagocytosis and respiratory burst activity of human neutrophils: an in vitro study.

Decaglycerol monooleate (DGMO), a type of polyglycerol esters of fatty acids (PGEF), was evaluated for its in vitro effect on phagocytosis and respiratory burst activity of isolated human neutrophils using flow cytometric assay. Opsonized zymosan particles labelled with FITC (FITC-OZ) were employed as an indicator of phagocytosis. Fluorescence of FITC-OZ attached on to the surface of neutrophils was quenched by addition of trypan blue solution. After 10 minutes of incubation with DGMO up to a concentration of 10 mg/ml, neutrophil phagocytosis was not affected markedly. At the same time, the DGMO emulsion left little influence on complement receptor type three (CR3) that is associated with phagocytosis. On the other hand, oxidation of hydroethidine, which was used as an indicator of intracellular generation of reactive oxygen species (mainly for superoxide anion), was significantly inhibited by DGMO over 1 mg/ml. However, this phenomenon was not seen in DGMO-treated neutrophils when DGMO was removed after incubation. The present data suggest that DGMO does not affect phagocytosis of human neutrophils but down-regulates respiratory burst activity.

Adult↗

PubMed2000

Occult breast cancer presenting axillary nodal metastasis: a case report.

We report a case of a 42-year-old female with occult breast cancer presenting axillary nodal metastasis. She complained of a swelling of the right axillary lymph node, but no breast mass was palpable. Biopsy of the lymph node was performed and histological examination showed a metastatic ductal carcinoma with papillotubular formation. Estrogen receptor of the lymph node was positive. No pathological findings were obtained by mammography and ultrasonography and systemic examinations revealed no extramammary primary lesion. All these data suggested an occult carcinoma of the breast and modified radical mastectomy was performed. Pathological findings of the removed specimen failed to find the primary breast cancer lesion. The patient has been treated with hormonal therapy and she is well without evidence of disease 5 years after surgery.

Adult↗

PubMed2000

Toxic shock syndrome after suction lipectomy.

We present a case of toxic shock syndrome with necrotizing fasciitis after suction lipectomy. The patient underwent aesthetic suction lipectomy of the abdomen, buttocks, and thighs during an office procedure by a cosmetic surgeon. On postoperative day 2, the patient was referred to the emergency department of our hospital because of pain. On admission, the patient was in toxic shock. She required intensive medical treatment for about 1 month, along with psychiatric help to adapt after the illness. Although toxic shock syndrome is a rare postoperative complication, every plastic surgeon should be acquainted with it. A combination of early recognition, diagnosis, and aggressive supportive therapy is the only successful treatment.

Adult↗

PubMed2000

Delays and continuation of hospital visits among HIV-infected persons and AIDS cases in Japan.

This study attempts to clarify the distribution patterns of delay between HIV transmission and the first hospital visit among HIV-infected persons and AIDS cases in Japan except those infected through blood products. Such hospital visit patterns were analyzed, and the rates of reporting for HIV/AIDS surveillance among diagnosed HIV-infected persons and AIDS cases in hospitals were shown. From 1991 to 1997, a survey and subsequent follow-up were conducted among HIV-infected persons and AIDS cases diagnosed at 74 hospitals in Tokyo. The numbers of HIV-infected persons and AIDS cases were 590 and 208, respectively. The percentage of patients whose estimated date of HIV transmission was obtained ranged 23-41% among Japanese and non-Japanese HIV-infected persons and AIDS cases. Among these patients, 28% to 86% showed a 3-year delay between HIV transmission and their first hospital visit. The rate of HIV-infected persons who continued to visit hospitals within 1 year after their first visit was 77% for Japanese and 45% for non-Japanese; among those after 1 year or more following their first hospital visit the rate was more than 80% among Japanese and over 70% among non-Japanese. The rate of reporting to HIV/AIDS surveillance among diagnosed HIV-infected persons and AIDS cases was 90% or more after 1994 in Japan. The delay between HIV transmission and the first hospital visit was suggested to be very long. Not a few patients stopped visiting hospitals after only a short time. Most diagnosed HIV-infected persons and AIDS cases were reported to the surveillance system of Japan.

HIV Infections↗

PubMed2000

beta-catenin mutations are absent in hepatocellular carcinomas of SV40 T-antigen transgenic mice.

beta-catenin mutations have been found not only in melanoma and prostatic carcinoma but also in hepatocellular carcinomas in human, c-myc, H-ras genes transgenic mice and chemically-induced models. We investigated beta-catenin mutations in human hepatocellular carcinomas (HCCs), Hep G2 cell line and HCCs in SV40 T-antigen transgenic mice, in order to examine whether beta-catenin mutations are frequently observed in HCC in general. We found a point mutation of beta-catenin in one of nine HCCs in human and a deletion of it in Hep G2 cell line. However, we found no mutation in HCC in SV40 TG mice liver.

Animals↗

PubMed2000

[A case of Down's syndrome associated with testicular seminoma].

Down's syndrome is an inherited disorder caused by trisomy of chromosome 21. In patients with Down's syndrome, an increased risk of leukemia has been observed. Recently, the coincidence of testicular cancer with this syndrome has been also emphasized. We present a case of Down's syndrome associated with testicular seminoma. This is the 19th case of Down's syndrome associated with testicular tumor in Japan.

Adult↗

PubMed2000

Reconstruction of congenital microtia by using a tissue expander.

In the conventional reconstruction of microtia, skin grafting is an absolute necessity because of the scantiness of the skin tissue at the affected site. As the result, color- and texture- matching as well as sensory preservation remain to be improved. To solve these problems, we developed a surgical procedure for reconstruction of microtia by using a tissue expander, which allowed us to reconstruct the erect auricle without the need for skin grafting. In this paper, we introduce and discuss our method using the tissue expander with a review of the literature. We operated on a total of 38 patients with microtia. Most of the patients were around 10 years of age, but 3 were adults. Autogenous cartilage was used, and the helix, antihelix, concha, and tragus were reproduced. Initially, 70 ml custom-made expanders were used; after that, 75 ml or 95 ml ready-made expanders were used. The erect auricle was reconstructed by the primary procedure in 33 patients. The reconstructed auricle was satisfactory in color- and texture-matching and had nearly normal sensation. No major absorption of the cartilage has been noted for 15 years, although a slight retraction of the expanded skin was observed in each patient. In conclusion, microtia repair by using a tissue expander is superior to that by conventional procedures in color- and texture- matching and sensory preservation of the reconstructed auricle.

Adult↗

PubMed1999

Determination of a new oral cephalosporin, S-1090, in human plasma and urine by direct injection high-performance liquid chromatography with ultraviolet detection and column switching.

Direct injection high-performance liquid chromatographic (HPLC) methods with column switching and UV detection were developed for the rapid and accurate determination of S-1090 in human plasma and urine. An internal-surface reversed-phase pre-column and a C18 analytical column were used for the plasma assay. Two pre-columns packed with cyano and phenyl materials and a C18 analytical column were used for the urine assay. The calibration curves for plasma and urine assays were linear in the ranges 0.09-9 microg/ml and 0.5-100 microg/ml of S-1090, respectively. The relative standard deviations for plasma and urine assays were less than 6% with low relative errors. The established HPLC methods were demonstrated to be useful for clinical pharmacokinetic studies after oral administration of S-1090.

Administration, Oral↗

PubMed1999

Association between duration of obesity and risk of non-insulin-dependent diabetes mellitus. The Sotetsu Study.

The authors investigated the association between duration of obesity (ordinary obesity as body mass index (BMI) (kg/m2) > or = 25.0 and extreme obesity as BMI > or = 27.8) and the risk of diabetes mellitus. Male employees of a railway company, aged 30 years or older, observed for 10 years or more, free from serious disease conditions, with initial BMI <25.0, aged 30 years or more at the time diabetes was diagnosed, and with complete data, were examined by univariate and multivariate analyses (n = 1,598). Age-adjusted odds ratios for diabetes were significantly increased among males who were obese for 10-19.9 years and >20 years (odds ratios = 2.10 and 2.84 for ordinary obesity and 6.14 and 4.15 for extreme obesity, respectively). Additional adjustment for current obesity, physical activity, smoking, drinking, family history, and observation period did not change the findings remarkably. In conclusion, > or = 10 years duration of ordinary obesity or > or = 1 year of extreme obesity was an important predictor for diabetes independent of age, current obesity, physical activity, smoking, drinking, family history, and observation period.

Adult↗

PubMed1999

Stimulatory effect of enkephalins on calcium efflux from bovine adrenal chromaffin cells in culture.

The effects of leucine- and methionine-enkephalin, opiate peptides, on Ca2+ efflux from cultured bovine adrenal chromaffin cells were examined. These enkephalins stimulated the efflux of 45Ca2+ from cells in a concentration-dependent manner (10(-8) M-10(-6) M). Leucine-enkephalin did not increase the intracellular free Ca2+ level, 45Ca2+ uptake, catecholamine secretion, cAMP level or cGMP level. The peptide-stimulated 45Ca2+ efflux was not inhibited by incubation in Ca2+-free medium, but was inhibited by incubation in Na+-free medium. These results indicate that enkephalins stimulate extracellular Na+-dependent 45Ca2+ efflux from cultured bovine adrenal chromaffin cells, probably by stimulating membrane Na+/Ca2+ exchange.

Adrenal Medulla↗

PubMed1999

Expression of basic fibroblast growth factor and its receptor in angiosarcoma.

Angiosarcoma, a rare aggressive malignant tumor thought to be of vascular origin with high potential for metastasis, frequently occurs on the scalp of elderly people. Recent findings have shown that overexpression of basic fibroblast growth factor and its receptor is associated with neoplasia, which suggests that basic fibroblast growth factor promotes tumor vascularization and subsequent growth. In this study, we examined the immunohistologic localization of basic fibroblast growth factor and its receptor in angiosarcoma. Our results suggest that basic fibroblast growth factor synthesized in the tumor endothelial cells plays an important role in the growth and progression in angiosarcoma and that serum basic fibroblast growth factor levels are elevated in patients with nodular type angiosarcoma.

Aged↗

PubMed1999

Proteolytic activation of protein kinase C delta and epsilon by caspase-3 in U937 cells during chemotherapeutic agent-induced apoptosis.

Protein kinase C (PKC) family members play pivotal roles in cellular signal transduction and nPKCdelta and theta are known to be subjected to restrictive proteolysis during apoptosis. Here we show that nPKCepsilon was specifically cleaved and generates 43-kDa and 36-kDa C-terminal fragments during chemotherapeutic drug-induced apoptosis. The proteolytic cleavage of nPKCdelta and epsilon was completely inhibited by pretreatment with Ac-DEVD-cho, a specific inhibitor of caspase-3 family enzymes. Furthermore, nPKCepsilon in non-treated U937 cell lysates was cleaved by purified recombinant caspase-3 to generate the 43-kDa fragment, identical in size to the fragment observed in vivo. This cleavage was prevented by the addition of Ac-DEVD-cho. These results suggest that caspase-3 specifically cleaves nPKCepsilon. These findings suggest the possibility that nPKC subfamily members are generally involved in the execution of apoptosis but they are regulated diversely depending on the different apoptotic stimuli.

Antineoplastic Agents↗

PubMed1999

Coffee drinking and serum gamma-glutamyltransferase: an extended study of Self-Defense Officials of Japan.

PURPOSE: To examine the effect of coffee drinking on serum gamma-glutamyltransferase (GGT) level in relation to alcohol drinking, smoking, and degree of obesity in middle-aged Japanese men. METHODS: From 1986 to 1994, a total of 7,637 male officials of the Self-Defense Forces of Japan aged 48-59 years received a preretirement health examination. Coffee drinking was ascertained by a self-administered questionnaire, and serum GGT level was measured. After excluding 1,360 men with a possible pathologic condition influencing liver enzyme levels and 182 former alcohol drinkers, effect of coffee drinking on serum GGT was examined by a multiple linear regression model and analysis of variance adjusting for alcohol drinking, smoking, and body mass index (BMI). RESULTS: The adjusted percentage of difference in serum GGT was -4.3 (95% CI = -5.0; -3.5) per cup of coffee. The inverse coffee-GGT relation was most prominent among men drinking > or = 30 ml of ethanol and smoking > or = 15 cigarettes daily; and positive associations of alcohol and smoking with GGT were attenuated by coffee drinking, more clearly among men with BMI > or = 25.00 kg/m2. Adjusted percentages of difference in serum GGT were -2.6% (p = 0.0003) per cup of brewed coffee, and -5.1% (p = 0.0001) per cup of instant coffee, independently of each other. CONCLUSIONS: The present study suggests that coffee consumption may weaken GGT-induction by alcohol, and possibly by smoking. These effect modifications by coffee may differ according to the degree of obesity.

Alcohol Drinking↗

PubMed1999

Further biocompatibility testing of silica-chitosan complex membrane in the production of tissue plasminogen activator by epithelial and fibroblast cells.

The effects of the physicochemical characteristics of a silica-chitosan complex membrane (SiCM) on the expression of tissue plasminogen activator (tPA) by contacting cells were investigated with the aim of improving the biocompatibility of the novel implant biomaterial. Expression of tPA is considered to be effective in wound healing by preventing thrombus formation, which causes inflammatory responses and rejection of implant materials. Inducing the epithelial cells surrounding implant materials to secrete tPA, which serves as an early signaling system to proliferate cells underlying connective tissues, would be further effective in accelerating wound healing. An epithelial 293 cell line derived from human embryonic kidney and a fibroblast IMR-90 cell line from human lung possessing the ability to secrete tPA were cultured on SiCMs, whose composition was stepwise controlled by adjusting the mixing ratio between silica and chitosan to give silica contents of 20, 33, 43, and 50wt%. Both strains showed strong adhesion on chitosan (0%-SiCM) and 50%-SiCM. The cell proliferation rates were also accelerated in a manner that was dependent on the increase in the adhesion strength of the cells cultured on the SiCMs. Furthermore, the tPA activity in the culture medium increased in accordance with the cell density, while the cellular specific activity of IMR-90 cells to secrete tPA was synergistically enhanced by strong adhesion and a high cell density on the surface of chitosan and 50%-SiCM. Analysis of the physico-chemical effects of the SiCMs revealed that the cells were dominantly affected by the surface hydrophobicity rather than by the zeta potential, as well as by the mixing ratio between chitosan and silica. The wet contact angles of 50%-SiCM and chitosan, which were 68 degrees and 65 degrees , respectively, were found to be suitable for adhesion and growth of both the epithelial 293 cells and fibroblast IMR-90 cells. A hydrophobic surface at 65 degrees -68 degrees was also effective for the production of tPA by IMR-90 cells, whereas the tPA activity of 293 cells reached its highest level on the SiCM with a wet contact angle of 63 degrees . These results suggest that a suitable adhesion strength is a significant factor in the expression of tPA by cells contacting an implant biomaterial.

Journal Article↗

PubMed1999

Exposure to diesel exhaust affects the male reproductive system of mice.

Several recent reports have suggested that sperm count and quality in normal men are declining. Various environmental chemical compounds may affect the male reproductive system. We propose here that diesel exhaust is an environmental pollutant with the potential to influence male reproductive function. Ultrastructural changes were observed in Leydig cells of mice exposed to diesel exhaust (0.3 mg diesel exhaust particles (DEP)/m3 through the airway, 12 h daily, up to 6 months) and reduction in LH receptor mRNA expression in Leydig cells was observed at a concentration of 1 mg DEP/m3. Daily sperm production per gram of testis dose-dependently decreased with exposure to DE for 6 months; 29%, 36%, and 53% reductions were observed at 0.3, 1.0, and 3.0 mg DEP/m3, respectively. A no-observed-adverse-effect level (NOAEL) was observed with approximately 30 micrograms DEP/m3, which is lower than the WHO-recommended limit.

Air Pollutants↗

PubMed1999

Ureteropyeloscopy in the diagnosis of patients with upper tract hematuria: an initial clinical study.

BACKGROUND: To study the usefulness and safety of ureteropyeloscopy in the diagnosis of upper tract hematuria of unknown etiology by standard diagnostic methods. METHODS: Fifteen patients with upper tract hematuria of unknown etiology were the subjects of the present study. Prior to ureteropyeloscopy, they underwent standard diagnostic methods, including cystourethroscopy, excretory urography and computed tomography scan. The upper tract (ureter, renal pelvis and calyces) was inspected systematically with a flexible ureteropyeloscope under epidural anesthesia. A biopsy specimen was obtained when neoplasm of a suspicious lesion was seen. Bleeding and hemangiomatous lesions were fulgurated at the time of ureteropyeloscopy. RESULTS: Unilateral gross hematuria was seen in 12 patients. Imaging studies revealed a filling defect in four patients, ureteral stenosis in one patient and nutcracker phenomenon in one patient. Urine cytology was positive in three patients and suspicious in four patients. Results of ureteropyeloscopy were papillary tumor in three patients, whitish encrustation in one patient, redness of the renal pelvis in one patient, bleeding from the renal calyx in two patients, hemangiomatous lesion in one patient, ureteral stenosis in two patients and no abnormalities in five patients. Biopsies were performed in five patients. The pathology results were transitional cell carcinoma in four patients and no abnormality in one patient. Although a ureteral stent catheter was placed in one patient, no serious complications were encountered during or after the procedures. CONCLUSIONS: Ureteropyeloscopy was useful and relatively safe. This endoscopic examination can differentiate insignificant lesions from significant lesions by visual inspection of the lesions, in addition, pathological diagnosis by biopsy specimen can also be performed if deemed necessary. Ureteropyeloscopy is recommended in the diagnosis of upper tract hematuria of unknown etiology.

Adult↗

PubMed1999

IL-4 inhibits the migration of human Langerhans cells through the downregulation of TNF receptor II expression.

The migration of Langerhans cells is an initial event in the sensitization phase of contact sensitivity. Langerhans cells travel from the epidermis to the regional lymph node, and can be variously modulated in the skin where many cytokines are released from epidermal cells, dermal cells, T helper (Th) cells, and other inflammatory cells during the sensitization and elicitation phase of contact dermatitis, and thus induce an altered inflammatory skin reaction. The modulatory effect of the cytokines released in the skin, such as IL-1beta, GM-CSF, and TNF-alpha as epidermal cytokines, IL-2, IL-12, and IFN-gamma as Th1 type cytokines, and IL-4 and IL-10 as Th2 type cytokines, was analyzed using the chemotactic chamber method in this study. Both GM-CSF and TNF-alpha induced the migration of human Langerhans cells in vitro, whereas IL-1beta, IL-2, IL-10, IL-12, and IFN-gamma had no effect on Langerhans cell migration. In contrast, IL-4 inhibited Langerhans cell migration in a dose dependent manner. The inhibitory activity of IL-4 was reversed by both anti-human IL-4 monoclonal antibody and anti-human IL-4 receptor monoclonal antibody. IL-4 inhibited the Langerhans cell migration induced by both TNF-alpha and GM-CSF. Furthermore, anti-TNF-RII monoclonal antibody inhibited both random migration and the migration induced by TNF-alpha, but not that induced by GM-CSF. A reverse-transcriptase-polymerase chain reaction and fluorescence-activated cell sorter analysis revealed that TNF-alpha up-regulated and IL-4 downregulated the TNF receptor II (TNF-RII) expression of Langerhans cells at both the mRNA and the protein levels. The pretreatment of Langerhans cells with TNF-alpha enhanced the migration of Langerhans cells and the expression of TNF-RII. After pretreating Langerhans cells with TNF-alpha, IL-4 inhibited both the migration of Langerhans cells and the expression of TNF-RII in a time dependent manner. These results indicate that IL-4 inhibits the migratory activity of Langerhans cells by downregulating the expression of TNF-RII in human Langerhans cells and thereby modulates the immune response in the skin.

Antibodies, Monoclonal↗