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Biomedical subjects

K Itoh

Publications and source records attributed to K Itoh.

At least 667 records · Page 37Linked to original sources
PubMed1996

Synthesis and tryptic hydrolysis of p-guanidinophenyl esters derived from amino acids and peptides.

A facile synthetic method for p-guanidinophenyl esters derived from a variety of amino acids and peptides, including D-amino acids, is presented. The kinetic behavior of trypsin towards these synthetic esters, inverse substrates, was analyzed. The spatial requirement of the enzyme active site for catalytic efficiency is discussed based on the steric characteristics of the substrates.

Amino Acid Sequence↗
PubMed1996

Trypsin-catalyzed peptide synthesis and various p-guanidinophenyl esters as acyl donors.

Trypsin-catalyzed peptide synthesis has been studied by using p-guanidinophenyl esters of N alpha-(tert-butyloxycarbonyl)amino acid and peptide as acyl donor components. The reaction conditions were optimized for organic solvents, pH, and concentration of acceptor. The method was especially useful for the preparation of various peptides containing D-amino acids. The enzymatic hydrolysis of the resulting products was negligible.

Acylation↗
PubMed1996

Optically active antifungal azoles. VI. Synthesis and antifungal activity of N-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazo l-1- yl)propyl]-N'-(4-substituted phenyl)-3(2H,4H)-1,2,4-triazolones and 5(1H,4H)-tetrazolones.

A new series of optically active antifungal azoles, N-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-tria zol-1- yl)propyl]-N'-(4-substituted phenyl)-3(2H,4H)-1,2,4-triazolones (1,2) and 5(1H,4H)-tetrazolones (3), were prepared from the triflate derivative of (1S)-1-[(2R)-2-(2,4-difluorophenyl)-2-oxiranyl]ethanol (13) by an SN2 displacement reaction with the anion of an azolone (17-19) and subsequent ring-opening reaction with 1H-1,2,4-triazole. The optically active oxiranylethanol 13 was synthesized from methyl (R)-lactate in a stereo-controlled manner. The azolones 1-3 prepared showed potent antifungal activities in vitro and in vivo.

Antifungal Agents↗
PubMed1996

Experimental hepatitis induced by Campylobacter jejuni infection in Japanese quail (Coturnix coturnix japonica).

To establish an experimental model for vibrionic hepatitis caused by Campylobacter jejuni, Japanese quails (Coturnix coturnix japonica) were inoculated with C. jejuni strains isolated from chicken hepatitis (BL107) and human diarrhea (HP5113). Necrotic liver lesions were formed by intra-pancreaticoduodenal vein injection by which the bacteria reached the liver directly via the portal vein, but not by intra-gastric infection. These liver lesions were observed from day 1 to 7 after the infection. The pathological changes were weak and no clinical signs were observed throughout the experimental period. By immunohistochemistry, the bacterial antigens were detected in the hepatocytes, and intercellular spaces between the hepatocytes, and in the macrophages during the early stage of the infection. When focal hepatocyte necrosis was formed, the antigen was detected more frequently in the intact hepatocytes at the periphery of the lesions than within necrotic foci. The bacteria were not detected from the liver, spleen or blood according to raising the serum agglutination titer. In contrast, the bacteria immediately invaded the bile in 5 min post-infection and were retained in the gallbladder for long periods. The present study showed that necrotizing hepatitis was formed by intra-pancreaticoduodenal vein infection of the quail with C. jejuni.

Animals↗
PubMed1996

Detection of serum-dependent cytotoxic activity of Campylobacter jejuni and its characteristics.

We previously set forth appropriate three assay systems using Chinese hamster ovary cells to detect the Campylobacter jejuni cytotoxin. Although we could not reach a conclusion because the cytotoxins shown in this study were not purified, at least three different cytotoxins were detected in these assay systems. The first cytotoxin in the presence of fetal calf serum (FCS) was heat-labile and the molecular weight (Mw) was estimated at 50-100 k by ultrafiltration. The second cytotoxin detected in the presence of newborn calf serum (NCS) was heat-stable and Mw was estimated at 0.5-3.0 k. The third cytotoxin detected in serum-free culture (SFC) assay was heat-labile and non dialyzable. However, Mw was not estimated since the low Mw and heat-stable cytotoxin was also detected in this assay. The cytotoxic activity detected in FCS and NCS assays, but not that detected in SFC assay, was completely abolished by treatment with a reducing agent. In contrast, the cytotoxicity detected in both FCS and NCS assays was not inactivated by such an enzyme as trypsin, lipase, neuraminidase, and beta-galactosidase. When the filtrate was heated at 100 degrees C to inactivate the heat-labile cytotoxin, the cytotoxic activity was detected in the NCS assay but not in FCS assay. However, when NCS was added to this heated filtrate, the cytotoxicity was restored in FCS assay. Furthermore, when normal rabbit serum (NRS) was added, no cytotoxicity was restored. The cytotoxic activity in SFC assay was completely inactivated with FCS or NRS. These findings suggest that the cytotoxic activity is dependent on serum added to tissue culture medium and that the substance amplifying and/or inhibiting the cytotoxic activity may be present in serum.

Animals↗
PubMed1996

Recurrent breast cancer treated successfully with mitomycin-C and vinblastine after failure of both doxorubicin-containing regimen and paclitaxel--a case report.

Cross-resistance is one of the chief obstacles in salvage therapy for refractory breast cancer. Although paclitaxel is one of the most promising drugs, it shows a response rate of 30% at most for patients with breast cancer resistant to doxorubicin, and no effective treatments for tumors refractory to both agents have been reported. We describe a 38-year-old woman with recurrent breast cancer, who was treated successfully with mitomycin-C and vinblastine after doxorubicin-based chemotherapy and paclitaxel failed. The combinations of mitomycin-C and microtubule inhibitors including vinca alkaloids and taxanes may have a potential application to refractory breast cancer.

Adenocarcinoma, Scirrhous↗
PubMed1996

Prevalence of Parkinson's disease in Hokkaido, the northernmost island of Japan.

The prevalence of Parkinson's disease (PD) was investigated in Hokkaido, the northernmost island of Japan. A pilot case-finding study was carried out to estimate the prevalence in the entire island of Hokkaido (population = 5,643,647) initially, then we surveyed the prevalence at one of the smaller cities, Iwamizawa City (population = 80,417). We ascertained 5,342 cases with PD in Hokkaido and 77 cases in Iwamizawa City, estimating the crude prevalence of 94.7/100,000 in Hokkaido (June 30, 1993) and 95.8/100,000 in Iwamizawa City (April 1, 1994), respectively. We calculated that the crude prevalence rate of PD in Japan in currently close to 100/100,000, but the age-adjusted prevalence is still low, compared with those in Europe and North America.

Adult↗
PubMed1996

CMV-infected subependymoma in the fourth ventricle of an HIV-1 infected patient.

A case of an AIDS patient with a CMV-infected subependymoma of the fourth ventricle is presented. The tumor was incidentally found at autopsy and was not suspected during the clinical course. This is the first report of a subependymoma in HIV-1 infection. Moreover, infection of a tumor with CMV is an extremely rare condition, which has until now been described only once in an anaplastic astrocytoma.

Acquired Immunodeficiency Syndrome↗
PubMed1996

[Autoimmune hemolytic anemia with eosinophilia in elderly patient].

A 70-year-old woman was admitted to our hospital in November 1992 for evaluation of anemia. Physical examination revealed anemia, jaundice, swelling of axial and inguinal lymph nodes, and splenomegaly. Abnormal hematological findings were as follows: Hb of 3.9 g/dl, reticulocyte count of 58.2% (61.7 x 10(4)/microliters), hyperplasia of normal erythroblasts in bone marrow, and eosinophilia (21.0%, 2352/microliters) in peripheral blood. Routine laboratory examinations revealed polycolonal hypergammaglobulinemia 3.0 g/dl, a high level of serum LDH (797 IU/I) and a total bilirubin of 2.4 mg/dl (indirect, 1.6 mg/dl). The serum haptoglobin level was very low (< 5 mg/dl). Results of serological examinations were as follows: IgG of 3366 mg/dl, CH50 of 16.0 U/ml, positive Coombs test 2+, and positive tests for antinuclear antibody, rheumatoid factor, and cold agglutinin. CRP was negative. PHA-stimulated lymphocyte blast formation, NK activity, and ADCC activity were found to be suppressed, and the percentage of CD4-positive lymphocytes in peripheral blood was also low. An axillary lymph node biopsy revealed reactive lymphadenitis. No signs or history suggested allergy, collagen disease, or parasitic infection. Autoimmune hemolytic anemia (AIHA) complicated by immunologic abnormalities and eosinophilia was diagnosed. Oral prednisolone markedly reduced the hemolytic anemia, eosinophilia, lymph node swelling, and splenomegaly, but NK activity remained low.

Aged↗
PubMed1996

Contact dermatitis caused by 2-HEMA and GM dentin primer solutions applied to guinea pigs and humans.

The purposes of this study were to examine whether 2-HEMA, GM, and methacrylic acid cause contact dermatitis, and to determine the optimum concentrations of these primers for sensitization and challenge in guinea pigs. A sensitizing concentration of 0.2% 2-HEMA resulted in strong rubefaction and several vesiculopapules in response to the challenge, and a sensitizing concentration of 0.5% GM produced strong rubefaction at 24 hours. We also observed the development of contact dermatitis on human brachia in a closed-patch test. Skin that was treated with both 2-HEMA and GM clearly showed the onset of rubefaction and itchiness. 2-HEMA caused sensitized delayed allergic reactions at all the concentrations tested.

Animals↗
PubMed1996

Evaluation of skin irritation and sensitization of two diol solutions used as experimental dentin primers in humans and guinea pigs.

The purpose of the present study was to evaluate the safety of ethylene glyco (EG) and 1,6-hexanediol (HD) solutions as experimental dentin primers when subjected to the guinea pig maximization test (GPMT), primary irritation test, cumulative skin irritation test and human patch test. No primary and cumulative skin irritation resulting from the use of 62.5% EG or 45% HD solutions was observed. In the case of GPMT, the animals sensitized with 2-hydroxyethyl methacrylate (2-HEMA) responded to 100% HD. 62.5% EG and 45% HD as dentin primers were safer than 2-HEMA such as a methacrylic primer.

Adult↗
PubMed1996

Contact angle of dentin bonding agents on the dentin surface.

Physical changes in the surface characteristics of dentin during bonding procedures were evaluated by measuring the contact angles of three standard liquids, to determine the surface free energy, and that of a commercially available dual cured dentin bonding agent dropped on the primed dentin surface. The commercial dentin bonding agent did not form a hemispherical shape on the ground dentin surface, probably because it penetrated into the smear layer due to the microcapillary effect. Not could the contact angle be measured on the dentin surfaces treated with any of four experimental primers, because the bonding agent rapidly spread over the primed dentin surface. It was concluded that the priming of the dentin surface after removing the smear layer served to increase the surface free energy and to improve the wettability of the bonding agent on the dentin.

Chemical Phenomena↗
PubMed1996

Quantification of renal function with a count-based gamma camera method using technetium-99m-MAG3 in children.

UNLABELLED: To evaluate renal function quantitatively without blood sampling in children, renal uptake by gamma camera renography using 99mTc-MAG3 was compared with plasma clearance by a single blood sample method as the reference. METHODS: Twenty children (15 boys, 5 girls; aged 2-14 yr) with nephrourological diseases were examined prospectively in this study. The patient received an intravenous administration of 5 MBq/kg 99mTc-MAG3 which was prepared using a commercially available kit. Gamma camera renography was performed and the renal uptake per injected dose (%RU) of the 1-min period of postinjection was calculated from a background-corrected renogram curve by computer. The plasma clearance (Clmag) of 99mTc-MAG3 was calculated by the single blood sample method at 35 min postinjection. RESULTS: The %RU of the 1-min period in the 1-3 min postinjection correlated well with Clmag. The best correlation was observed 1-2 min postinjection. The regression equation between total %RU (X) and Clmag (Y) (ml/min/1.73 m2) was Y = -98.509 + 20.373X (r = 0.910, s = 84.19) with standardization by BSA. The best fit regression equation between individual %RU (X) and Clmag (Y) (ml/min/1.73m2) was Y = -43.799 + 19.917X (p = 0.932, s = 43.27). CONCLUSION: The renal uptake method based on separate counts by gamma camera renography using 99mTc-MAG3 does not require a blood sample for quantification of renal function and may be potentially more practical in children.

Adolescent↗
PubMed1996

Cold activation of complement for monitoring the response to interferon in patients with chronic hepatitis C.

OBJECTIVES: Because of its specific association with hepatitis C virus (HCV) infection, the cold activation of complement is an easy and inexpensive indicator of HCV viremia. It was evaluated for eligibility as a marker of response to interferon in patients with hepatitis C. METHODS: The cold activation of complement was determined by the loss or decrease of hemolytic activity with the microtitration method in sera that had been stored at 4 degrees C overnight. RESULTS: We observed the loss of hemolytic activity by the cold activation of complement in 236 (72%) and a decrease in 56 (17%) of 327 sera from patients with HCV-associated chronic liver disease, which was much more (p < 0.001) that in 1 (1%) and 13 (14%), respectively, of 49 sera from patients with chronic liver disease associated with hepatitis B virus infection. Interferon-alpha (total dose 516 x 10(6) units) or interferon-alpha 2b (774 x 10(6) units) was given to 67 patients with chronic hepatitis C, of whom 56 had the cold activation of complement. The response to interferon was evaluated by the clearance of serum HCV RNA at 6 months after the completion of therapy. The cold activation of complement disappeared in 18 patients, of whom 15 (86%) responded. It persisted or fluctuated in the remaining 38 patients, only six (16%) of whom responded to interferon (p < 0.001). The cold activation of complement once disappeared at the completion of interferon and then reappeared in patients who relapsed after completing interferon therapy. CONCLUSIONS: These results indicate that the cold activation of complement may be associated with the presence of HCV in blood and a lower rate of durable response after completion of interferon therapy.

Adult↗
PubMed1996

[A case of pulmonary dirofilariasis].

A 41-year-old man was admitted to the hospital for detailed evaluation of chronic hepatitis C. A nodular shadow (15 x 15 mm) was detected in the left middle lung field on a chest X-ray film. Roentgenologic, cytologic, and bronchial endoscopic examinations resulted in no definitive diagnosis. To rule out a malignant tumor the left lung was partially resected (S6). Histological examination of the resected specimen revealed Dirofilaria worms in a necrotic mass. In most cases of pulmonary dirofilariasis, thoracotomy is done to confirm the diagnosis. Recently, however, antibodies against Dirofilaria have been detected by immunologic methods and have been used to help make the diagnosis in some cases. A less invasive procedure, such as a reliable immunologic test or a technique for thoracoscopic resection, would be very useful in cases of this benign condition.

Adult↗
PubMed1996

[Measurement of serum tissue polypeptide antigen (TPA) in patients with malignant tumor using prolifigen TPA-M "Daiichi" kit].

Serum tissue polypeptide antigen (TPA) was measured using a newly developed Prolifigen TPA-M "Daiichi" kit in 1,236 healthy subjects, 2,867 patients with malignant tumors, and 901 with benign diseases. Because 94.0% of healthy subjects had serum TPA under 70 U/l, the cut-off value was set at 70 U/l. Serum TPA was elevated in more than 50% of patients with head and neck cancer, lung cancer, liver cancer, gallbladder or bile duct cancer, pancreatic cancer, colorectal cancer, ovarian cancer, and prostate cancer. The overall positive rate in malignant tumors was 55.5%. Serum TPA was higher in advanced cancer than in earlier stage cancer, and decreased after the resection of the tumor. The false positive rate in benign diseases was 31.3%. ROC analysis revealed the usefulness of TPA as a tumor marker in many cancers. The correlation coefficient between TPA and CYFRA 21-1, and between TPA and TPSA, was 0.747 and 0.694, respectively. In conclusion, measurement of serum TPA using the new kit is useful in the management of patients with various malignant tumors.

Antigens, Neoplasm↗
PubMed1996

Estimation of the position and orientation of the kinematic axis of the temporomandibular joint.

The kinematic axis refers to a theoretical intercondylar axis of the temporomandibular joint, which translates on a curved surface during all sagittal movements. In normal joints, the translation of this rotational axis is nearly reciprocal. Its estimation is arrived at in two steps: (i) axis points are estimated in several sagittal planes, using data of sagittal mandibular movements, and (ii) an axis is then fitted to them. Neither of them, however, takes into consideration any geometric constraints on the trajectories of the kinematic axis. To correct this theoretical inconsistency, this paper presents a technique capable of directly exploring the position and orientation of the axis. During exploration, the axis is evaluated by the extent of its motion range, which is approximated from trajectile data obtained at several points on the axis. The validity of this technique was verified, through experiments employing data of actual mandibular movements.

Adult↗