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N Tomizawa

Publications and source records attributed to N Tomizawa.

At least 19 recordsLinked to original sources
PubMed2001

Effects of FK3311 on pulmonary ischemia-reperfusion injury in a canine model.

BACKGROUND: This study investigated the effects of a selective COX-2 inhibitor, FK3311, on warm ischemia-reperfusion (I/R) injury in the canine lung. MATERIALS AND METHODS: Sixteen adult mongrel dogs were used in this study. In the FK group (n = 8), FK (1 mg/kg) was administered intravenously 15 min before ischemia and 15 min before reperfusion. In the control group (n = 8), a vehicle was injected in the same manner. Warm ischemia was induced for 3 h by clamping the left pulmonary artery, veins, and bronchus. Five-minute clamping tests of the right pulmonary artery were performed before ischemia and 30 min after reperfusion. During the test, left pulmonary vascular resistance (L-PVR), cardiac output (CO), and arterial oxygen pressure (PaO(2)) were measured. The lung specimens were simultaneously harvested for wet-to-dry weight ratio (WDR) measurements, histopathological studies, and polymorphonuclear neutrophil (PMN) counts. Serum thromboxane (Tx) B(2) and 6-keto-prostaglandin (PG) F(1alpha) (stable metabolites of TxA(2) and PGI(2), respectively) were also measured 30 min after reperfusion. RESULTS: L-PVR, CO, PaO(2), and WDR were significantly (P < 0.05) better in the FK group than in the control group. Histological tissue edema was mild, and PMN infiltration was significantly (P < 0.05) reduced in the FK group compared to the control group. The serum TxB(2) levels were significantly (P < 0.05) lower in the FK group than in the control group, while 6-keto-PGF(1alpha) levels were not significantly (P < 0.05) reduced. Two-day survival rate was significantly (P < 0.05) better in the FK group than in the control group. CONCLUSIONS: FK has protective effects on pulmonary I/R injury stemming from marked inhibition of TxA(2).

6-Ketoprostaglandin F1 alpha↗
PubMed2001

The effect of cyclooxygenase-2 inhibitor FK3311 on ischemia-reperfusion injury in a canine total hepatic vascular exclusion model.

BACKGROUND: Liver grafts from non-heart-beating donors inevitably suffer from warm ischemic injury. In these grafts, large quantities of inflammatory cytokines and arachidonic acid metabolites are induced, further aggravating injury. Cyclooxygenase (COX) is an intracellular enzyme that converts arachidonic acid into prostaglandin (PG)G2 and PGH2. COX has two isoforms: constitutive COX-1 and inducible COX-2. The aim of this study was to evaluate the effects of COX-2 inhibition by FK3311 (FK) on warm ischemic injury in a canine total hepatic vascular exclusion (THVE) model. STUDY DESIGN: Sixteen mongrel adult dogs were studied. The portal triad of the hilum and the inferior vena cava above and below the liver was clamped for 1 hour. Splanchnic decompression was achieved by active splenofemorojugular bypass. The animals were divided into two groups. FK (1 mg/kg) was administered in the FK group (n = 8), and saline was administered in the control group (n = 8). Hepatic venous blood was collected to measure serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase (LDH), and hyaluronic acid levels. Serum thromboxane (Tx)B2 and 6-keto-PGF1alpha levels were also measured. Hepatic tissue blood flow was estimated simultaneously. Liver specimens were harvested for histologic study and polymorphonuclear neutrophils were counted. RESULTS: Alanine aminotransferase, aspartate aminotransferase, and hyaluronic acid 2 and 6 hours after reperfusion and LDH 30 minutes and 2 and 6 hours after reperfusion were significantly (p < 0.05) lower in the FK group than in the control group. Hepatic tissue blood flow remained significantly (p < 0.05) higher in the FK group than in the control group 1, 2, and 6 hours after reperfusion. Histologic tissue damage was mild and polymorphonuclear neutrophil infiltration was significantly lower (p < 0.05) in the FK group than in the control group 1 and 6 hours after reperfusion. Thirty minutes after reperfusion, TxB2 was significantly reduced (p < 0.05) in the FK group, and 6-keto-PGF1alpha was not significantly lower. CONCLUSIONS: FK protected against hepatic warm ischemia-reperfusion injury by marked inhibition of TxA2.

6-Ketoprostaglandin F1 alpha↗
PubMed2001

Results of duct-to-mucosa pancreaticojejunostomy for pancreaticoduodenectomy Billroth I type reconstruction in 100 consecutive patients.

BACKGROUND: This study retrospectively analyzed 100 consecutive patients who underwent pancreaticoduodenectomy (PD) and pylorus-preserving PD (PPPD) with a Billroth I type reconstruction and pancreaticojejunostomy by duct-to-mucosal anastomosis using a continuous running suture. STUDY DESIGN: Seventy patients underwent PD and 30 patients PPPD for pancreatic cancer in 33, bile duct cancer in 28, ampullary or duodenal tumor in 22, chronic pancreatitis in 8, and other gastrointestinal cancer in 9. Postoperative pancreatic anastomotic leakage was diagnosed from skin excoriation around the drain site, and was defined as a high concentration of amylase in drainage fluid or leakage demonstrated on x-ray. RESULTS: The mortality rate was 2% overall (2.8% in PD, 0% in PPPD). The morbidity rate was 23% overall (12.8% in PD, 46.7% in PPPD). Pancreatic anastomotic leakage was 4.0% overall (2.8% in PD, 6.7% in PPPD).. The incidence in the ampullary or duodenal tumors was 9.1% overall (0% in PD, 14.3% in PPPD). Biliary leakage occurred in four patients, 4.0% overall (4.3% in PD, 3.3% in PPPD), intraabdominal hemorrhage in 2% (2.8% in PD, 0% in PPPD), and lethal anastomotic leakage in one patient, overall rate 1% (1.4% in PD, 0% in PPPD). Delayed gastric emptying had the highest morbidity and was seen exclusively in PPPD (39.3%). CONCLUSIONS: A simple continuous running suture and parachuting for duct-to-mucosal pancreaticojejunostomy makes pancreaticoduodenectomy a safe procedure, even in a Billroth I type reconstruction.

Anastomosis, Surgical↗
PubMed2001

Effects of endothelin receptor antagonist TAK-044 on small bowel autograft from a controlled non-heart-beating donor model.

BACKGROUND: This study investigated the possibility of pharmacologic protection using an endothelin (ET) receptor antagonist, TAK-044 (TAK), for small bowel autograft in a canine controlled non-heart-beating donor (NHBD) model. METHODS: Sixteen adult mongrel dogs were allocated into 2 groups. TAK (3 mg/kg) (n = 8) was administered intravenously 30 minutes before ischemia and 30 minutes before graft reperfusion. Vehicle was administered in the control (n = 8). The superior mesenteric artery and vein were clamped for 90 minutes to induce warm ischemia as a controlled NHBD model. The entire small bowel then was harvested and stored in 4 degrees C University of Wisconsin solution for 4 hours. The autograft was transplanted orthotopically. Mucosal tissue blood flow, intramucosal pH (pHi), and serum ET-1 levels were measured. Specimens were evaluated histopathologically and ET-1 immunohistochemically. RESULTS: TAK provided significantly higher tissue blood flow and pHi at 3 and 6 hours after graft reperfusion and significantly higher serum ET-1 levels at 1 hour after graft reperfusion as compared with the control group. TAK had histopathologic tissue damage graded as superficial, did not reach to grade 5 on Park's grading as in controls, and provided less intense immunoreactivity for ET-1 immunohistochemical staining. CONCLUSIONS: TAK may have clinical application in small bowel transplantation from controlled NHBD or conditions related to ischemia-reperfusion (I/R) injury.

Animals↗
PubMed2001

Low-dose erythromycin reduces delayed gastric emptying and improves gastric motility after Billroth I pylorus-preserving pancreaticoduodenectomy.

OBJECTIVE: To test the hypothesis that early and low doses of erythromycin reduce the incidence of early delayed gastric emptying (DGE) and induce phase 3 of the migratory motor complex in the stomach after Billroth I pylorus-preserving pancreaticoduodenectomy (PPPD). SUMMARY BACKGROUND DATA: Delayed gastric emptying is a leading cause of complications after PPPD, occurring in up to 50% of patients. High doses of erythromycin (200 mg) accelerate gastric emptying after pancreaticoduodenectomy and reduce the incidence of DGE, although they induce strong contractions that do not migrate to the duodenum. METHODS: Thirty-one patients were randomly assigned to either the erythromycin or control groups. The patients received erythromycin lactobionate (1 mg/kg) every 8 hours, or H2-receptor antagonists and gastrokinetic drugs from days 1 to 14 after surgery. On postoperative day 30, gastroduodenal motility was recorded in 14 patients. RESULTS: Preoperative, intraoperative, and postoperative factors were comparable in the erythromycin and control groups. The erythromycin group had a shorter duration of nasogastric drainage, earlier resumption of eating, and a 75% reduction in the incidence of DGE. Erythromycin was an independent influence on nasogastric tube removal, and preservation of the right gastric vessels was a significant covariate. Low doses of erythromycin induced phase 3 of the migratory motor complex and phase 3-like activity, with the same characteristics as spontaneous phase 3, in 86% of patients: two had quiescent stomachs and the others had spontaneous phase 3 or phase 3-like activity. CONCLUSIONS: Low doses of erythromycin reduced the incidence of DGE by 75% and induced phase 3 of the migratory motor complex after Billroth I PPPD. Low doses of erythromycin are preferable to high doses in the unfed period after PPPD.

Adult↗
PubMed2001

Cloning and sequencing full length of canine Brca2 and Rad51 cDNA.

Mammary tumors are the most common neoplasm in female dogs, Canis canis, and in women. Mutations in human Brca2 confer an increased risk of female breast cancer. Previous studies have shown that the Brca2 tumor suppressor protein interacts with the recombinational repair protein Rad51. We cloned the full-length cDNA of the canine homologues of Brca2 and Rad51 to obtain a basis for studying their relationship with susceptibility to mammary tumors. The canine Brca2 and Rad51 cDNAs are 11 and 1.5 kb long, encoding 3.471 and 339 amino acids, respectively. The amino acid sequence of canine Brca2 showed 68% homology with the human protein, and 58% homology with a murine protein. There were highly conserved regions in the C-terminus of all three proteins, where the Rad51 interacting domain and putative nuclear localization signals are located. Comparing with the partial genomic sequence previously reported, we found possible nuclear polymorphisms in exon 11, some of which result in amino acid substitutions. On the other hand, canine Rad51 protein had extremely high homology (99%) to the human and murine proteins. Expression of both Brca2 and Rad51 was detected in the mammary gland, suggesting that these two genes interact in the canine mammary gland.

Amino Acid Sequence↗
PubMed2001

Pituitary chromophobe carcinoma with a low level of serum gonadotropin and an aspermatogenesis in a dog.

A 5-year-old male Shiba dog with progressive neurologic signs was examined by computed tomography (CT). A CT image of the brain disclosed a large, spherical high-density lesion in the thalamus and diencephalon. Serum LH, FSH and testosterone levels were all low. Macroscopically the large mass was connected with the sella turcia, and it was histopathologically diagnosed as a pituitary chromophobe carcinoma. An aspermatogenesis was observed in the testes. Therefore, it was suggested that the low levels of gonadotropin secretion from the pituitary gland due to the pituitary tumor resulted in the failure of maturation of spermatozoa and spermatids.

Adenocarcinoma↗
PubMed2001

Chronopharmacology of oral prednisolone in rats.

The chronopharmacology of oral prednisolone (PSL) was studied in rat models. Differences in the dosing-time-dependent toxicity were evaluated at four time points (3, 9, 15 and 21 HALO) in adult male Wistar rats and confirmed in an inbred strain of Lewis rats (MHC haplotype; RTIl) at two time points (9 and 21 HALO). The total body weight and that of the immunologic-related organs were maximally reduced when PSL was repeatedly administered during the late active phase (21 HALO). This chronotoxicity was independent of plasma concentrations of PSL, adrenocorticotropic hormone, and corticosterone. Repeated administration of PSL prolonged cardiac allograft survival in a DA (RTIa) -to-Lewis combination, and there was a tendency to be more effective in the 21 HALO trial. These results suggested that single dose therapy of PSL at the selected point of the day may be less harmful, protecting against allograft rejection.

Administration, Oral↗
PubMed2000

Cell dynamics and expression of tumor necrosis factor (TNF)-alpha, interleukin-6, and TNF receptors in angioimmunoblastic lymphadenopathy-type T cell lymphoma.

Angioimmunoblastic lymphadenopathy (AILD)-type T cell lymphoma is histologically characterized by a mixed infiltrate of atypical T cells and B cells including B immunoblasts and plasma cells as well as eosinophils accompanied by proliferation of high endothelial venules. These morphological peculiarities are widely believed to reflect an abnormal pattern of cytokine expression. To clarify the cell dynamics and cytokine expression pattern in the lymph nodes of AILD-type T cell lymphoma, the frequency of proliferating/apoptotic cells and localization of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 producing cells were determined. Double staining was performed for (1) cell markers and Ki-67 antigen, (2) cell markers and the terminal deoxytransferase-mediated dUTP nick end labeling (TUNEL) method, or (3) cell markers and cytokines. The proliferating cell ratio in atypical T cells of AILD-type T cell lymphoma determined by Ki-67 labeling was 20.2+/-5.0%, while other peripheral T cell lymphomas (PTL) exhibited a ratio of 32.9+/-2.5%. TUNEL-positive apoptotic cells were 0.8+/-0.1% of total cells in AILD-type T cell lymphoma. They were dominantly atypical cells with positive T cell markers. In contrast, lymphoma cells in other types of PTL or paracortical cells in reactive follicular hyperplasia had only 0.3+/-0.1 or 0.4+/-0.1% TUNEL-positive cells, respectively. Thus, lymphoma cells in AILD-type T cell lymphoma demonstrated suppressed proliferating activity and enhanced apoptosis when compared to other types of PTL. TNF-alpha-producing cells were observed in all of the lymph nodes from AILD-type T cell lymphoma cases (15/15) and positive staining was obtained in the majority of atypical T cells and scattered macrophages. In contrast, IL-6 was localized to clusters of atypical T cells in some of the cases (9/15). Further, the expression of TNF-alpha, IL-6, and TNF receptors I and II (TNFRI and TNFRII) was examined by RT-PCR. The TNF-alpha message (2/2) and IL-6 message (2/2) was present in the lymph nodes of AILD-type T cell lymphoma by examination using RT-PCR, while both messages were negative in control cases (0/7). As far as an expression of mRNA for TNF receptors in AILD-type T cell lymphoma cases, mRNA for TNFRI was definitely expressed in both of the cases (2/2) while TNFRII mRNA was weakly expressed in one case (1/2). Overexpression of TNF-alpha as well as TNFRI may play a role in controlling T cell proliferation through an autocrine (T cell-T cell interaction) and paracrine (macrophage-T cell interaction) fashion. IL-6, which was also expressed by part of lymphoma cells of AILD-type T cell lymphoma, facilitates the proliferation of B cells, plasma cells, and T cells or endothelial cells in the lymph nodes of AILD-type T cell lymphoma.

Adult↗
PubMed2000

FR167653 ameliorates pulmonary damage in ischemia-reperfusion injury in a canine lung transplantation model.

BACKGROUND: Interleukin (IL)-1 and tumor necrosis factor-alpha (TNF-alpha) are recognized as important factors in ischemia-reperfusion (I/R) injury. FR167653 has been characterized as a potent suppressant of IL-1 and TNF-alpha production. We previously reported that FR167653 suppressed the expression of IL-1 beta mRNA after reperfusion and ameliorated pulmonary I/R injury following 3-hour left lung warm ischemia in dogs. The aim of this study was to investigate the effects of FR167653 on I/R injury in a canine left, single, lung transplantation model. METHODS: We used 10 pairs of weight-matched dogs. We assigned 5 pairs to the FR group, in which each animal received FR167653 (1 mg/kg/hr) IV from 30 minutes before ischemia until 2 hours after reperfusion; we treated the transplanted lungs with FR167653 after the onset of reperfusion. The others were assigned to the control group. After 8-hour preservation with 4 degrees C Euro-Collins solution, orthotopic left, single, lung transplantation was performed. During a 5-minute clamping test at the right pulmonary artery of each recipient, the left (transplanted) pulmonary arterial pressure (L-PAP), left (transplanted) pulmonary vascular resistance (L-PVR), arterial oxygen pressure (PaO(2)), and alveolar-arterial oxygen pressure difference (A-aDO(2)) were measured. We harvested transplanted lung specimens for histologic study, and we counted polymorphonuclear neutrophils (PMNs), which were identified by staining with naphthol AS-D cholroacetate esterase. Pulmonary perfusion and ventilation scintigraphy (Tc-99m-MAA and Xe-133) were performed. We observed the animals for 3 days after transplantation. RESULTS: The PAP, L-PVR, PaO(2), and A-aDO(2) revealed significantly (p < 0.05) better function in the FR group than in the control group. Histologically, lung edema was milder, and PMN infiltration was significantly (p < 0.05) lower in the FR group than in the control group. Xe-133 and Tc-99m-MAA were widely distributed throughout the graft lung in the FR group. Three-day survival rates in FR and control groups were 60% and 20%, respectively. CONCLUSIONS: FR167653 appears to generate a protective effect on I/R injury in lung transplantation in dogs.

Animals↗
PubMed2000

The effect of FK409-a nitric oxide donor-on canine lung transplantation.

BACKGROUND: Nitric oxide (NO) is known to have beneficial effects in ischemia-reperfusion (I/R) injury through maintaining endothelial integrity, inhibiting leukocyte adhesion and platelet aggregation, and inducing vasodilation. The effect of FK409 (FK), a spontaneous NO donor, was investigated in a canine lung transplantation model. METHODS: Ten pairs of weight-matched dogs were used. Five pairs were assigned to the FK group, to which FK (5 microg/kg/min) was administered intravenously from 30 minutes prior to ischemia until the induction of ischemia in the donor, and from 15 minutes prior to reperfusion until 45 minutes after reperfusion in the recipient. The others were assigned to the control group. After 8-hour preservation in 4 degrees C Euro-Collins solution, orthotopic single-lung transplantation was performed. During a 5-minute clamping test of the right pulmonary artery, left pulmonary arterial pressure (L-PAP), left pulmonary vascular resistance (L-PVR), arterial oxygen pressure (PaO(2)), and alveolar-arterial oxygen pressure difference (A-aDO(2)) were measured. The lung specimens were harvested for histologic study, and polymorphonuclear neutrophils (PMNs) were counted. Pulmonary perfusion and ventilation scintigraphy (Tc-99m-MAA and Xe-133) were performed. RESULTS: PAP, L-PVR, PaO(2), and A-aDO(2) revealed significantly (p < 0.05) better function in the FK group than in the control group. Histologically, edema was more mild, and PMN infiltration was significantly (p < 0.05) lower in the FK group than in the control group. Xe-133 and Tc-99m-MAA were widely distributed throughout the graft lung in the FK group. The 2-day survival rate was 100% in the FK group, which was significantly (p < 0.05) better than the rate (40%) in the control group. CONCLUSIONS: FK appears to generate a protective effect on I/R injury in lung transplantation.

Animals↗
PubMed1999

The effect of neutrophil elastase inhibitor in hepatectomy with ischemia in dogs.

Activated neutrophils play an important role in reperfusion injury following hepatic ischemia. Neutrophil elastase is a powerful proteolytic enzyme. We investigated the possibility that ONO-5046. Na, which is a new recombinant-specific neutrophil elastase inhibitor, can reduce ischemia and reperfusion injury in the canine liver. Adult mongrel dogs (n = 19) were used in this experimental study. Seventy-five percent of the liver was resected after 60 min of vascular occlusion. The animals were divided into two groups. The ONO group (n = 8) was given ONO-5046. Na dissolved in saline starting 30 min prior to clamping the hepatic inflow and continuing for 4 h after reperfusion at a rate of 10 mg/kg/h. The nontreatment group (n = 11) received a saline solution for the same period. ALT and LDH levels were significantly lower (P < 0.05) in the ONO group than in the nontreatment group after reperfusion. Purine nucleoside phosphorylase and hyaluronic acid levels, which are markers of endothelial damage, were significantly lower (P < 0.05) in the ONO group than in the nontreatment group after reperfusion. Histologically, widely spread hepatocyte necrosis was found in dogs in the nontreatment group that died prematurely. Neutrophil infiltration of the sinusoids was less evident in the ONO group than in the nontreatment group. Neutrophil elastase inhibitor may prevent injuries of both endothelial and parenchymal cells in extended hepatectomy with vascular occlusion.

Alanine Transaminase↗
PubMed1999

The effects of a neutrophil elastase inhibitor (ONO-5046.Na) and neutrophil depletion using a granulotrap (G-1) column on lung reperfusion injury in dogs.

BACKGROUND: Activated neutrophils are reported to be closely involved in ischemia-reperfusion injury after lung transplantation. We investigated the beneficial effects of a new recombinant specific neutrophil elastase inhibitor, ONO-5046.Na, and an extracorporeal-type granulotrap (G-1) column on ischemia-reperfusion lung injury, by using an in situ warm lung ischemia model in dogs. METHODS: Warm ischemia was induced for 3 hours by clamping the pulmonary arteries and veins. The left main bronchus was bisected and reanastomosed prior to reperfusion. The left lung was collapsed for 3 hours. A total of 27 adult mongrel dogs were divided into three groups: the control group (n = 9) treated with a saline vehicle; the ONO group (n = 9), in which ONO-5046.Na was continuously administrated from before induced ischemia and to ending 2 hours after reperfusion; and the G-1 group (n = 9), in which a G-1 column was applied for 90 minutes starting 30 minutes before reperfusion under passive bypass support. RESULTS: Circulating neutrophils in the G-1 group decreased significantly (p<.05) compared to preischemia, and significantly decreased compared with the other groups after reperfusion. Oxygenation was improved actually and pulmonary vascular resistance was kept lower level after the administration of ONO-5046.Na. The increase of lung weight was significantly ameliorated in both the G-1 and ONO groups. In the histopathological study, lungs from the control group demonstrated diffuse alveolar edema, neutrophil infiltration, massive alveolar exudate and hemorrhage, and thickening of the interstitium. Lungs from the G-1 group showed mild swelling of the alveolar wall and neutrophil infiltration. Lungs from the ONO group showed virtually no abnormalities. CONCLUSION: This study demonstrated that a neutrophil elastase inhibitor and neutrophil depletion prevented lung reperfusion injury. These treatments may prevent ischemia and reperfusion injury in lung transplantation.

Animals↗
PubMed1999

Effects of a phosphate buffered extracellular (Ep4) solution in preservation and reperfusion injury in the canine liver.

The Ep4 solution, a phosphate buffered extracellular-type solution, is effective in canine lung transplantation following a 96-hour hypothermic (4 degrees C) preservation. In this experiment, we used this solution for liver preservation followed by transplantation. We compared the Ep4 solution with the lactated Ringer's (LR) and the Collins' M (CM) solution (a phosphate buffered intracellular-type solution) in two studies, 1) 48-hour liver preservation, and 2) orthotopic liver transplantation after 5-hour preservation. In the preservation study, purine nucleoside phosphorylase (PNP) levels as a marker of endothelial damage, and alanine aminotransferase (ALT) levels were significantly lower in the livers immersed into the Ep4 solution than in those immersed into other solutions at 36 and 48 hours after preservation. Microscopically, the endothelial injury occurred 24 hours after preservation in the CM solution, and 36 hours after preservation in the LR and Ep4 solutions. In the transplantation study, serum PNP and ALT levels in the livers immersed in Ep4 solution showed a lower tendency compared with those in other solutions at the time of reperfusion, but the histological differences among three groups were not apparent. The present study suggests that the liver can be stored better for a longer time using Ep4 solution than using LR and CM solutions.

Alanine Transaminase↗