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Biomedical subjects

M Nozawa

Publications and source records attributed to M Nozawa.

At least 19 recordsLinked to original sources
PubMed2006

Endoanal ultrasonography in the diagnosis and operative management of perianal endometriosis: report of two cases.

We report two cases of perianal endometriosis in which we were greatly assisted by endoanal ultrasonography. Patient 1 was a 43-year-old woman with perianal pain. Endosonography showed a hypoechoic mass in the anterior perianal region without involvement of the anal sphincter. Local excision was performed under spinal anesthesia without damage to the anal sphincter. Patient 2 was a 30-year-old woman with perianal pain coinciding with her menstrual period. Endosonography showed a heterogeneous mass containing cystic anechoic areas in the right anterior perianal region and involving the external anal sphincter. Wide excision, including the episiotomy scar and part of the external anal sphincter, and primary sphincteroplasty were performed under spinal anesthesia. According to our experience, preoperative endosonography is a reliable technique for visualizing perianal endometriosis and for diagnosing anal sphincter involvement. Operative management should be determined on the basis of preoperative and intraoperative ultrasonographic assessment.

Adult↗
PubMed2006

Regulation of donor T cells in the tolerant rats to graft-versus-host disease by FTY720 following small bowel transplantation.

AIMS: The potency of immunosuppression is a critical factor in small bowel transplantation (SBTx). FTY720 altered lymphocyte trafficking and prevented the donor T cells from migrating into target organs, resulting in the prolongation of recipient survival in acute graft-versus-host disease (GVHD) of SBTx. However, the effect of FTY720 on donor T cells in the chronic phase of GVHD following SBTx remains unclear. METHODS: Heterotopic SBTx was performed in a WF-to-F1 (WF x ACI) rat combination. Recipients were given FTY720 for 14 days after SBTx. The subpopulations of donor-derived T cells and the cytokine production in the target tissues were evaluated on postoperative day 150. RESULTS: FTY720 treatment significantly prolonged recipient survival over 150 days without any clinical signs of GVHD. The numbers of donor-derived CD4+ and CD8+ T cells in the peripheral blood, mesenteric lymph nodes, and Peyer's patches of recipients were maintained at low levels on postoperative 150, which were almost similar to the levels on postoperative day 14. In the host lamina propria, however, a significant higher number of donor T cells (CD4+, 18.4 +/- 4.3 x 10(4); CD8+, 13.9 +/- 3.6 x 10(4)) were still observed on postoperative day 150. Production of interferon-gamma was significantly reduced in target tissues by FTY720 treatment both in the acute and chronic phase. However, interleukin-4 and interleukin-10 production, which was significantly higher on day 14, returned to the level of naive rats in the chronic phase. CONCLUSIONS: A 14-day treatment of FTY720 induced tolerance in our SBTx model. Down-regulation of both Th1 and Th2 immune response was observed in the chronic phase.

Animals↗
PubMed2006

Inhibition of donor-derived T cells trafficking into target organs by FTY720 during acute graft-versus-host disease in small bowel transplantation.

In small bowel transplantation (SBTx), graft-versus-host disease (GVHD) is mediated by donor-derived T cells recognizing host major histocompatibility complex (MHC) alloantigens, and represents an important immunological event influencing life in experimental and clinical situations. We evaluated the possibility that a new sphingosine 1-phosphate receptor agonist, FTY720, could diminish GVHD in a rat SBTx model through traffic alteration of donor-derived T cells in target organs. Heterotopic SBTx was performed using a parent (WF)-into-F(1) (WF x ACI) rat combination. Recipient survival, body weight, histopathology, donor-derived T cell subpopulation and cytokine production were compared with untreated controls. FTY720 inhibited lethality and histopathological changes in target organs when administered at 0.5 mg/kg, possibly due to sequestration of donor-derived T cells in the intestinal graft. FTY720 caused a significant reduction in donor T cell numbers in target organs by promoting these cells to home into donor, but not recipient, secondary lymphoid tissues. FTY720 significantly decreased production of interferon (IFN)-gamma in target organs. These findings indicate that FTY720 effectively reduced recirculation of activated donor-derived T cells and recruitment to target organs in GVHD, and was also associated with down-regulated IFN-gamma production. These properties may offer the potential to treat ongoing GVHD in SBTx.

Acute Disease↗
PubMed2002

Pharmacokinetic and pharmacodynamic analysis of TS-943, a selective non-peptide platelet glycoprotein-IIb/IIIa (GPIIb/IIIa) receptor antagonist, using a nonlinear mixed effect model in dogs.

A simultaneous analysis of the pharmacokinetics and pharmacodynamics of TS-943, a selective nonpeptide platelet glycoprotein-IIb/IIIa (GPIIb/IIIa) receptor antagonist, was made in dogs using a nonlinear mixed effect model. Plasma concentrations of TS-943 were determined after bolus intravenous injection, constant infusion and bolus plus constant infusion. Pharmacokinetic/pharmacodynamic data were fitted using NONMEM software. The pharmacokinetics of TS-943 fitted a two-compartment open model with first-order elimination. The pharmacodynamic model that best fitted platelet aggregation was an inhibitory sigmoid Emax model. The final estimates for E0 (baseline effect), Emax (maximum effect), IC50 (50% inhibitory concentration) and gamma (Hill coefficient) were 66.3%, 64.3%, 104 ng mL(-1) and 1.37, respectively. Correlations between TS-943 plasma concentration and extension of template bleeding time were examined by fitting with an exponential model. The TS-943 plasma concentration necessary to double bleeding time (C2-BTE) was approximately 209 ng mL(-1). The model estimated that the C2-BTE/IC50 (inhibition of platelet aggregation) ratio was approximately 2.0-fold in dogs. Our results suggest that the ratio values for dogs and man are comparable. A nonlinear mixed effect model was a useful tool for exploring the concentration-effect relationship for both efficacy and safety of TS-943 in dogs and man. In this study, the dog was found to be a useful model for screening of efficacy and safety of TS-943 in man.

Amidines↗
PubMed2001

Visualization of signal propagation from sciatic nerve to spinal cord in canine.

The neuroelectric activity that ascends the sciatic nerve and moves to the spinal cord was visualized by measuring the magnetic compound action fields (CAFs) with a superconducting quantum interference device gradiometer. The sciatic nerve of a dog was stimulated electrically, and propagating evoked CAFs were measured non-invasively. Isomagnetic field maps were made on the basis of this data, and the signal propagation was visualized. The evoked magnetic fields presented a quadrupole consisting of two elements: depolarization and repolarization. Measuring the magnetic CAFs of the sciatic nerve on the body surface enabled us to visualize the non-invasively the signal movement continuously from the sciatic nerve to the spinal cord.

Animals↗
PubMed2001

Syngeneic consecutive rat spleen transplantation bearing infantile testis.

Seventy-seven Lewis adult rats received autologous testicular implants in the spleen. These spleens were retransplanted in a consecutive transplant fashion as we described earlier. Some were observed as long as 26 to 27 months. Although earlier splenic-testicular transplants showed benign granulosa cell tumors, some of the long-term follow-ups showed a seminoma-like transformation.

Animals↗
PubMed2001

Effects of albumin infusion therapy on total and unbound bilirubin values in term infants with intensive phototherapy.

BACKGROUND: The purpose of the present study was to evaluate the effect of intravenous albumin administration on the serum total and unbound bilirubin values in term non-hemolytic hyperbilirubinemic neonates during intensive phototherapy. METHODS: Fifty-eight infants (gestational age 39.4 +/- 1.4 weeks; birth weight 3,245 +/- 435 g) were given phototherapy with similar light energy. Twenty infants (control group) received only phototherapy, while 38 others (albumin-treated group) were also given human albumin at 1 g/kg bodyweight, i.v., during the first 2 h of phototherapy. RESULTS: When comparing changes in total and unbound bilirubin values 0, 2, 6 and 24 h after entering the study between the albumin-treated group and the control group, there was a significant reduction in the serum unbound bilirubin values at the end of albumin treatment and at 6 and 24 h. However, there was no significant reduction in total serum bilirubin values during the study period. In the albumin-treated group, the mean serum unbound bilirubin reduction from the baseline level at the end of albumin treatment and at 6 and 24 h was 0.40 +/- 0.19, 0.41 +/- 0.20 and 0.43 +/- 0.20 microg/dL, respectively. CONCLUSIONS: The results suggest that albumin priming may be effective for an immediate reduction in serum unbound bilirubin values, the fraction that is potentially neurotoxic.

Albumins↗
PubMed2001

Preventive management of hypoglycemia in very low-birthweight infants following indomethacin therapy for patent ductus arteriosus.

BACKGROUND: To evaluate the effects of an increase in glucose infusion rate of 2 mg/kg per min from the basal infusion rate on the prevention of hypoglycemia in very low-birthweight (VLBW) infants, following indomethacin therapy for patent ductus arteriosus (PDA). METHODS: Forty VLBW infants with PDA were given indomethacin 0.2 mg/kg intravenously up to three doses. In 15 of the 40 infants (supplemented group: between April 1995 and March 1996) the glucose infusion rate was increased in 2 mg/kg per min increments from the basal rate just before the initial indomethacin administration, compared with 25 historical control infants who received a fixed glucose infusion rate during the first 12 h after the initial dose. We evaluated the changes in blood glucose levels and glucose infusion rates in both groups. RESULTS: In the control group 11 of 25 (44%) infants had a blood glucose value below 40 mg/dL between 12 and 60 h (mean 32.7 h). In contrast only two out of 15 infants in the supplemented group reached the glucose level below 40 mg/dL between 72 and 96 h but both two were light-for-dates infants (defined as birthweight below the 10th percentile for gestational age on the standard intrauterine growth curve). Blood glucose values in the supplemented group were significantly higher than those in the control group between 12 and 96 h. However, glucose infusion rates were similar before and between 72 and 96 h. CONCLUSIONS: This retrospective study shows that an increase in glucose infusion rate of 2 mg/kg per min, in addition to the pre-existing stable maintenance glucose intake, might prevent against the occurrence of unexpected hypoglycemia in VLBW infants following indomethacin therapy.

Blood Glucose↗
PubMed2001

Oral combination of cyclophosphamide, uracil plus tegafur and estramustine for hormone-refractory prostate cancer.

OBJECTIVE: To evaluate the clinical usefulness of an oral combination of cyclophosphamide, uracil plus tegafur (UFT) and estramustine in the treatment of patients with hormone-refractory prostate cancer (HRPC). METHODS: Twenty-one patients were treated with oral administration of cyclophosphamide (100 mg/day), UFT (400 mg/day) and estramustine phosphate (560 mg/day). The median age of the patients was 70 years. Twelve patients had symptomatic bone metastasis, 6 had asymptomatic bone metastasis, 5 had lymph node metastasis, while 2 had only biochemical progression evaluated by prostate-specific antigen (PSA). RESULTS: Twelve (57%) out of 21 patients showed a PSA decline of 50% or greater. The median response duration was 7 months (range 2-15 months). Among the 20 patients assessable for bone pain, 2 (10%) improved, 12 (60%) remained stable and 6 (30%) progressed. Among the 10 patients assessable for bone metastasis, 1 (10%) improved, 5 (50%) were stable and 4 (40%) progressed on bone scan. Among 3 patients assessable for measurable disease (lymph node metastasis), 2 (67%) showed partial response and 1 (33%) progression. Most toxicities were mild. CONCLUSIONS: The combination of cyclophosphamide, UFT and estramustine is an active and well-tolerated regimen for HRPC. To evaluate the survival benefit, further randomized studies are required.

Administration, Oral↗
PubMed2001

Wear of resin-modified glass ionomers: an in vitro study.

The purpose of this study was to evaluate the wear resistance and clinical applicability of resin-modified glass ionomer cements as restorative or fissure-sealing materials. The in vitro wear of resin-modified glass ionomers was compared to conventional glass ionomers, a resin-based sealant, and a composite resin. A three-body wear test (enamel block--polymethylmethacrylate powder--experimental dental material) was performed by 20,000 cycles with a load of 4 kgf/cm2. The depth of wear of the experimental materials was measured and calculated using a computerized laser surface scanner. The glass ionomers generally showed more wear than the resin-based sealant and the composite resin, but there was no difference in wear between resin-modified and conventional glass ionomers. Type III ionomers (used for sealant) showed lower wear resistance than type II ionomers (used for restoration).

Bisphenol A-Glycidyl Methacrylate↗
PubMed2001

[Hypersensitivity pneumonitis caused by a factory humidifier. A case report].

A 64-year-old man was hospitalized for productive cough and dyspnea. Both chest radiographs and CT scans showed areas of ground-glass opacity in the middle and lower lung fields on both sides. The BAL and TBLB findings were compatible with hypersensitivity pneumonitis. The serum was negative for antibodies against Trichosporon species, and the result of a lymphocyte stimulating test for administered drugs including a Chinese medicine was also negative. A humidifier was suspected as the cause because it had been used for more than 10 years in the factory where the patient had been working. An inhalation test using the humidifier fluid successfully provoked dyspnea, fever and fine crackle, and laboratory tests demonstrated hypoxemia, reduction in vital capacity and the elevation of CRP. Agar gel diffusion using the patient's serum showed a precipitating line against Cephalosporium acremonium, but this line did not fuse with any precipitating line formed between the humidifier fluid and the serum, indicating that no Cephalosporium was Present in the humidifier fluid. Since a high level of beta-D glucan was detected in the humidifier fluid, an unidentified fungus was suspected to be the antigen.

Acremonium↗
PubMed2001

Evaluation of insulin secretion of isolated rat islets cultured in extracellular matrix.

Islet isolation involves enzymatic digestion of the interstitial matrix and mechanical disruption of the tissue. It is possible that a fundamental change of islet biology resulting from the loss of critical factors required for islet function or survival will occur. Extracellular matrix (ECM) is one of the most important components of the islet microenvironment. Reconstruction of the cell-matrix relationship seems to be effective for improving the loss of differentiated islet structure and function. The purpose of this study was to characterize and compare the effects of collagen gel mixture or Matrigel on beta-cell function and islet cell survival. After isolation by the collagenase digestion technique, rat islets were divided and cultured with various types of collagen gel mixture. They were assessed for their glucose-stimulated insulin secretion and cell viability. Glucose-induced insulin secretion of islets cultured with collagen type I gel or a mixture of collagen type I and IV was improved after 11 days in culture. In conclusion, a type of gel composed of collagen type I and/or type IV as an islet microenvironment is sufficient to maintain glucose responsiveness and may be useful for islet transplantation.

Animals↗
PubMed2001

Development of a new method to induce angiogenesis at subcutaneous site of streptozotocin-induced diabetic rats for islet transplantation.

The subcutaneous space is a potential site for clinical islet transplantation. Even though there are several advantages, poor blood supply at this site mainly causes failure of islet survival. In this study, angiogenesis was induced in advance at the diabetic rats subcutis for islet transplantation by implanting a polyethylene terephthalate (PET) mesh bag containing gelatin microspheres incorporating basic fibroblast growth factor (bFGF) (MS/bFGF) and a collagen sponge. The bFGF was incorporated into gelatin microspheres for controlled release of bFGF. As controls, a PET mesh bag with or without either collagen sponges or MS/bFGF was implanted at the subcutaneous site of diabetic rats. Macroscopic and microscopic examinations revealed the formation of capillary network in and around the PET mesh bag containing MS/bFGF and collagen sponges 7 days after implantation when compare with other control groups. When tissue hemoglobin level was also measured, a significantly high level of hemoglobin amount was observed compared with that of control groups. When allogeneic islets mixed with 5% agarose were transplanted into the prevascularized rat subcutis, normoglycemia was maintained for more than 40 days, while other control groups were ineffective. This study demonstrated that combination of gelatin microspheres incorporating bFGF and collagen sponges enabled the mesh to induce neovascularization even at the subcutaneous site of streptozotocin-induced diabetic rats, resulting in improved function of islet transplantation.

Animals↗
PubMed2001

Isolation, culture, and characterization of endocrine cells from 6-month-old porcine pancreas.

Porcine endocrine cells were isolated from pancreas of 6-month-old pigs by two-step enzymatic digestion procedures. They were separated by the density gradient (isopycnic) centrifugation method using Histopaque-1077. Isolated cells were cultured and divided into two groups: suspension cells and adhesion cells. Suspension cells maintained their cell numbers on and after 7 days in culture. Approximately 1 x 10(7) cells were obtained from single pancreas of a 6-month-old pig. The cultured suspension cells took up dithizone (DTZ) staining 14 days after isolation in culture and indicated the presence of beta-cells. In in vitro study, the suspension cells were capable of secreting insulin into the culture medium. The suspension cells were tested for insulin and glucagon staining by Western blot analysis. These results indicated the maintenance of endocrine cell function after isolation. However, cultured adhesion cells failed to maintain their function during culture. In in vivo study, the suspension cells were transplanted into diabetes-induced nude mice. Reduction in blood glucose level was obtained after transplantation. Intraperitoneal glucose tolerance test (IPGTT) results showed a normal pattern of blood glucose clearance. After 1 week, the transplanted endocrine cells were detected with anti-insulin antibody by immunostaining and it showed the presence of viable beta-cells under the renal capsule of nude mice. Collectively, our results suggest that isolated and cultured suspension porcine endocrine cells maintained their endocrine function. These endocrine cells can be used as isolated islets for further study, including transplantation experiments.

Animals↗
PubMed2001

Removal and decomposition of malodorants by using titanium dioxide photocatalyst supported on fiber activated carbon.

Effective and compact deodorization systems have been required for the measure of small-scale emission sources of offensive odors usually found in urban areas. We have developed a sheet material with titanium dioxide (TiO2) photocatalyst supported on fiber activated carbon (FAC) for a compact deodorization system. In the deodorization system using the TiO2/FAC sheet and a ultraviolet lamp, malodorants can be collected on the TiO2/FAC sheet by adsorption and then decomposed by photocatalysis with UV-irradiation. In this study, we obtained basic information about the removal and the decomposition of malodorants in the photocatalytic deodorization system using the TiO2/FAC sheet. The malodorants used in this study were methyl mercaptan, ammonia, and hydrogen sulfide. In addition, two kinds of light sources, a black light bulb (BLB; dominant wavelength: 365 nm) and an ultraviolet germicidal lamp (UV2; dominant wavelength: 254 nm) were used to analyze the effect on removal and decomposition characteristics by different dominant wavelengths. The removal rates of malodorants from the gas phase were determined in the deodorization system in the presence or absence of the TiO2/FAC sheet and UV-irradiation in order to study each removal effect due to adsorption onto the TiO2/FAC sheet, direct photolysis by UV-irradiation, and photocatalytic decomposition. The effect of adsorption onto the TiO2 /FAC sheet was pronounced in this batch-type experiment. The effect of photocatalysis was observed from the removal rates of methyl mercaptan. The percent oxidation of ammonia to nitrate and that of methyl mercaptan to sulfate were examined by determining products, i.e. nitrate and sulfate ions, with purified water after the reaction. The formation of nitrate or sulfate was not observed without UV-irradiation using the BLB, while the reactions progressed in the presence of the TiO2/FAC sheet. When the UV2 lamp was used, the oxidation of methyl mercaptan to sulfate occurred without the TiO2/FAC sheet. This suggests that the decomposition characteristics of malodorants were dependent on the wavelength of the light source.

Air Pollutants↗
PubMed2000

Importance of donor-derived lymphocytes in the protection of pancreaticoduodenal or islet grafts from recurrent autoimmunity: a role for RT6+NKR-P1+ T cells.

BACKGROUND: A rat pancreas transplantation model with insulin-dependent diabetes mellitus (IDDM) recurrence was established using a Wistar-Furth (WF; RT1u, RT6.2) rat as a donor and diabetes-prone (DP; RT1u, rt6.1 gene carrier) BioBreeding rat as a recipient. Interestingly, NKR-P1+TCRalphabeta+ (NKT) cells have recently been reported to have immunoregulatory functions in preventing autoimmune diabetes. The purpose of this study was to specifically examine the contribution of NKT cells in the prevention of IDDM recurrence. METHODS: Graft survivals with or without anti-intercellular adhesion molecule-1/leukocyte function-associated antigen-1 monoclonal antibodies were examined comparing pancreaticoduodenal (PD) transplantation with islet transplantation or pancreas-alone transplantation excluding duodenum and peripancreatic lymph nodes, in an IDDM recurrent model. The cells of the spleen were analyzed by flow cytometry (including intracellular interleukin (IL)-4 analysis), and serum cytokine levels (IL-4 and interferon-gamma) were determined by enzyme-linked immunosorbent assays (ELISA). RESULTS: Only those DP recipients transplanted with PD grafts with monoclonal antibody treatment were free from IDDM. Flow cytometric analyses of spleen cells showed that NKT cells in them, compared with those in the recurrent DP recipients (mean <7%), increased significantly (13.7+/-3.1% in the total splenic T cells), most of which (85.9+/-4.3%) were derived from the donor (RT6.2+). The absolute number of RT6+NKT cells significantly increased in the nonrecurrent DP recipients, whereas that of RT6-NKT cells was similar with those of the other recurrent DP recipients. These RT6+NKT cells were predominantly CD4+ and showed significantly more expressions of intracellular IL-4 than the other T cells. By ELISA, serum interferon-gamma was not detectable (< 13 pg/ml) in any of the rats. However, IL-4 was detected at 111.6+/-47.8 pg/ml only in the nonrecurrent DP recipients. CONCLUSIONS: Unlike islet or pancreas-alone transplants, NKT cells, especially RT6+NKT cells derived from PD grafts, may have an important immunoregulatory function of preventing IDDM recurrence, involving a Th2 deviation.

ADP Ribose Transferases↗