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Biomedical subjects

M Fukuzawa

Publications and source records attributed to M Fukuzawa.

At least 19 recordsLinked to original sources
PubMed2006

Effect of FTY720 in rat small bowel transplantation: apoptosis of crypt cells and lymphocytes in gut-associated lymphoid tissues.

AIM: We investigated the extent of apoptosis in crypt cells and Peyer's patches (PPs) during small bowel allograft rejection in rats to examine the effect of FTY720 during rejection. METHODS: Orthotopic small bowel transplantations (SBTs) were performed from BN to LEW rats. Isografted animals served as controls. Three groups of SBT animals were studied on days 3, 5, and 7 after operation: isograft, untreated allograft, allograft with FTY720. FTY720 was orally administered by gavage (1 mg/kg/d) to allograft recipients on 7 consecutive days. Cryostat sections were prepared from grafts, including PPs. An in situ end-labeling (ISEL) technique was used to detect apoptotic cells. Indirect immunoperoxidase staining was also performed using monoclonal antibodies against rat Fas/Fas-L. RESULTS: Graft survival was prolonged in the FTY720-treated group. The number of ISEL-positive enterocytes in the allografts increased significantly on days 3, 5, and 7 compared with the isograft group. In the FTY720-treated group, the number of ISEL-positive enterocytes in the allografts was down-regulated significantly on days 3, 5, and 7 compared with untreated allograft group. In the PPs, the number of ISEL-positive mononuclear cells increased significantly in the allografts compared with the isograft group. In the FTY720-treated groups, the number of ISEL-positive mononuclear cells were down-regulated significantly in the allografts compared with the untreated allograft group. The number of Fas/FasL-positive enterocytes were increased significantly in allografts compared with isograft group. In FTY720-treated groups, the number of Fas/FasL-positive enterocytes were down-regulated significantly on day 7 compared with the untreated allograft group. In the PPs, Fas/FasL-positive mononuclear cells also increased significantly on day 7 in the allografts compared with isografts. In the FTY720-treated groups, Fas/FasL-positive mononuclear cells were down-regulated significantly in the allografts compared with the untreated allograft group. CONCLUSIONS: The number of apoptotic enterocytes, lymphocytes, and Fas/FasL-positive lymphocytes increased during small bowel graft rejection. FTY720 prevented up-regulation of the number of apoptotic enterocytes, lymphocytes, and Fas/FasL-positive lymphocytes while also prolonging small bowel allograft survival.

Animals↗
PubMed2006

Cross-species function of the pig C1 esterase inhibitor.

BACKGROUND: The use of a bioartificial liver with pig cells for the treatment of fulminant hepatic failure will require research on the plasma complement regulatory proteins of the pig, because the liver produces most of the complement components and plasma complement regulatory proteins. In our previous study, the pig C1 esterase inhibitor (C1-INH), which functions as an inhibitor of the complement reaction in the first step of the classical pathway in the fluid phase, was cloned and some relevant features of the molecule were characterized, especially its cross-species regulation, in comparison with human C1-INH. In a further analysis, the species specificity of C1-INH was examined, using pig endothelial cells (PEC) and several types of sera. MATERIALS AND METHODS: The cDNA of pig C1-INH was used to produce the membrane type pC1-INH, pC1-INH-PI, and inserted into the cloning site of pCXN2 (chicken beta actin promoter). The pCX/pCl-INH-PI plasmid was then transfected into PEC to establish stable PEC with pCl-INH-PI. The expression of the pCl-INH-PI was evaluated by a FACS analysis, and complement-dependent cell lysis with human, dog, rabbit, and mouse sera was then assessed. RESULTS: The transfectant with pig Cl-INH-PI showed a high level of expression on PEC. The PEC transfectants showed an inhibitory effect on complement-dependent PEC lysis. Pig Cl-INH did not show the same suppressive effect for each serum. However, considering the alternative pathway activation of each serum on the pig cell membrane, it can be concluded that pCl-INH has a relatively small species restriction. CONCLUSION: Pig Cl-INH, having a similar structure to human Cl-INH, shows a strong complement regulatory function on other species sera.

Actins↗
PubMed2005

Effect of FTY720 in rat small bowel transplantation: expression of mucosal addressin cell adhesion molecule-1.

AIM: Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) mediates the homing of lymphocytes to gut-associated tissues (GALT). We performed a semiquantitative analysis of MAdCAM-1 expression during small bowel graft rejection in rat treated with FTY720. METHODS: Orthotopic small bowel transplantations (SBT) were performed from BN rats to LEW rats. Isografted animals served as controls. Three groups of SBT animals were studied on days 3, 5, 7 after operations (Isograft, untreated allograft, allograft with FTY720). FTY720 was orally administered by gavage (1 mg/kg/d) to allograft models on 7 consecutive days. Cryostat sections were prepared from grafts, including Peyer's patches (PPs). Indirect immunoperoxidase staining was performed using mAbs against MAdCAM-1. The degree of vascular endothelial staining on high endothelial venules (HEV) in the PPs was graded from 1 (low levels) to 5 (high levels), and in the vessels of the lamina propia from 1 (faint), to 2 (low at the base of villi), 3 (low to the middle of villi), 4 (high to the middle of villi), to 5 (high to villi tip). RESULTS: The graft survival was prolonged in the FTY720-treated group. MAdCAM-1 expression on HEVs in PPs was down-regulated during rejection. In contrast its expression on endothelial cells of vessels in the lamina propria was up-regulated during rejection. In the FTY720-treated groups, MAdCAM-1 expression on HEVs in PPs was up-regulated and its expression on endothelial cells of vessels in the lamina propria was down-regulated compared with untreated allograft group. CONCLUSIONS: Alteration in MAdCAM-1 expression may be associated with the development of SB graft rejection. The vessels at the base of villi, which are associated with lymphocyte recruitment, may become sites of intestine immune reactivity during the early phase of small bowel allograft rejection. FTY720 was found to prevent the down-regulation of MAdCAM-1 expression on HEVs in PPs and the up-regulation of its expression on endothelial cells of vessels in the lamina propria while also prolonging small bowel allograft survival.

Animals↗
PubMed2005

The effect of human command phonetic characteristics on auditory cognition in dogs (Canis familiaris).

Six dogs (Canis familiaris) were trained to sit and come reliably in response to tape-recorded commands. The phonemes within these commands were then changed, and the dogs' behavior in response to these modified commands was recorded. Performance markedly declined in all cases, with the type of alteration affecting response to the modified sit command but not to the modified come command. The results suggest that dogs do not perceive a tape-recorded command as simply a physical sound but that they recognize a relationship between certain sounds.

Animals↗
PubMed2004

Semiquantative analysis of expression of mucosal addressin cell adhesion molecule-1 during small bowel graft rejection in rats.

AIM: Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) mediates the homing of lymphocytes to gut-associated lymphoid tissues (GALT). We performed a semiquantative analysis of MAdCAM-1 expression during small bowel graft rejection. METHODS: Orthotopic small bowel transplantations (SBT) were performed from BN rats to LEW rats. Isografted animals served as controls. Animals were sacrificed on days 3, 4, 5, 6, and 7 after SBT. Cryostat sections were prepared from grafts, including Peyer's patches (PPs). Indirect immunoperoxidase staining was performed using mAbs against MAdCAM-1. The degree of vascular endothelial staining on high endothelial venules (HEV) in the PPs was graded from 1 (low levels) to 5 (high levels), and in the vessels of the lamina propria from 1 (faint), 2 (low at the base of villi), 3 (low to the middle of villi), 4 (high to the middle of villi), to 5 (high to villus tip). RESULTS: MAdCAM-1 expression on HEVs in PPs was down-regulated during rejection. In contrast its expression on endothelial cells of vessels in the lamina propria was up-regulated during rejection. CONCLUSION: Alteration in MAdCAM-1 expression may be associated with the development of SB graft rejection. The vessels at the base of villi, which are associated with lymphocyte recruitment, may become sites of intense immune reactivity during the early phase of small bowel allograft rejection.

Animals↗
PubMed2004

Apoptosis of crypt cells and lymphocytes in gut-associated lymphoid tissues during small intestinal graft rejection in rats.

INTRODUCTION: We investigated the extent of apoptosis in crypt cells and Peyer's patches (PPs) during small bowel allograft rejection in rats to examine whether the Fas/FasL pathway participates in apoptosis within grafts during rejection. MATERIALS AND METHODS: Orthotopic small bowel transplantation with portocaval drainage was performed from Brown Norway to Lewis (LEW) rats. Isografted (LEW --> LEW) and nontransplanted animals served as the controls. Animals were sacrificed on days 3, 5, on 7 after SBT (each n = 5). An in situ end-labeling (ISEL) technique was used to detect apoptotic cells. Indirect immunoperoxidase staining was also performed using monoclonal antibodies against rat Fas or Fas-L. RESULTS: The number of ISEL-positive enterocytes in the allografts increased significantly on days 3, 5, and 7. Similarly, in the PPs of the allografts, the number of ISEL-positive mononuclear cells increased significantly on days 3, 5, and 7. On day 7 the number of Fas- and FasL-positive enterocytes were increased significantly in the allografts compared with the nontransplanted controls. Similarly, in the PPs, Fas- and FasL-positive mononuclear cells also increased significantly on day 7 in the allograft. CONCLUSION: Although an increase, number of apoptotic enterocytes and lymphocytes were observed in the early phase, activation of Fas/FasL system occurred during the late phase of small bowel graft rejection. These findings suggest that both rejection-associated and sepsis-induced forms of apoptosis may be associated with small bowel graft rejection.

Animals↗
PubMed2003

Expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) during small-bowel graft rejection in rats.

BACKGROUND: Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is a critical endothelial adhesion molecule for lymphocyte trafficking to gut-associated lymphoid tissues (GALT) under physiological conditions. It is expressed on special postcapillary venules, that is the high endothelial venules (HEV) in GALT. In this study, we investigated changes in MAdCAM-1 expression during small-bowel graft rejection. METHODS: Orthotopic small-bowel transplantation (SBT) with portocaval drainage was performed from brown Norway (BN) rats to Lewis (LEW) rats. Isografted (LEW --> LEW) and untransplanted animals served as controls. Animals were killed on days 3, 4, 5, 6 and 7 after SBT. Cryostat sections (6 microm thick) were prepared from normal small-bowel tissues and small-bowel grafts, including Peyer patches (PPs). Indirect immunoperoxidase staining was performed using monoclonal antibodies (mAbs) against rat MAdCAM-1 (OST12). RESULTS: In the PPs of controls, MAdCAM-1 antibodies specifically stained the endothelial cells of HEV, which were predominantly located in the interfollicular areas. In the allografts on day 4 after SBT, the MAdCAM-1 expression was weaker on the HEV in the PPs than in the controls. In the lamina propria of controls, a faint expression of MAdCAM-1 on vessels was observed. On day 4 after allogeneic SBT, the MAdCAM-1 was more strongly expressed on the endothelial cells of the vessels at the base of the villi. As rejection developed, the MAdCAM-1 expression on the vessels progressed toward the villus tip. CONCLUSIONS: The change of MAdCAM-1 expression may be involved in the development of small-bowel graft rejection. The vessels at the base of villi, which is associated with lymphocyte recruitment, may become a site of intense immune reactivity in the early phase of small-bowel allograft rejection.

Animals↗
PubMed2002

Histologic criteria for the diagnosis of allied diseases of Hirschsprung's disease in adults.

A few reports in the literature have discussed the histologic criteria for the diagnosis of allied diseases of Hirschsprung's disease in adults, and studies report that intestinal neuronal dysplasia (IND) in adults may develop from IND in infants. The aim of this study was to examine the differences between the histological findings of IND in infants and those in adults, and to assess whether allied diseases of Hirschsprung's disease (HD) in adults should be considered as congenital or acquired diseases. For these purposes, we studied nine adult patients with severe constipation, and an adult patient with acute intestinal obstruction. We routinely examined the patients using barium enema, anorectal manometry and rectal mucosal biopsy. However, in patients suspected of allied diseases, we carried out full-thickness rectal biopsies. In seven operated cases, we also examined resected intestines. The tissue samples were examined using AChE-staining, NADPH-diaphorase staining, HE-staining, and silver impregnation. Histologically, we diagnosed two males as having HD, two males as having IND, five patients (two males and three females) as having hypoganglionosis, and one female as having a degeneration of the intramural plexus. The following conclusions were drawn: 1) Inflammations such as ulcerative colitis or ischemic colitis may cause IND TYPE B in adults whose histological findings are similar to those generally seen in infants; 2) It is suggested that IND is closely related to hypoganglionosis; 3) In hypoganglionosis, a patient with findings of elevated AChE-positive nerve fibers in the mucosa and AChE-positive nerve fibers in an arterial wall may belong to a subtype of IND; 4) Most of the allied diseases of HD in adults may occur as an acquired disease, not as a congenital disease.

Adult↗
PubMed2002

Analysis of pancreaticobiliary ductal union based on intraoperative cholangiography in patients undergoing laparoscopic cholecystectomy.

BACKGROUND: In order to diagnose pancreaticobiliary maljunction (PBM), it is necessary to perform direct fluoroscopic examinations of the biliary tract system. For patients with benign biliary diseases, these examinations are performed only in selected cases, because they are generally invasive. We investigated whether intraoperative cholangiography was practicable in evaluating the presence of PBM in patients with benign biliary diseases who underwent laparoscopic cholecystectomy (LC). METHOD: Between March 1998 and February 2001, intraoperative cholangiography (IOCG), which is one of the direct fluoroscopic examinations, was attempted in all 100 patients who underwent LC. RESULTS: IOCG was completed successfully in 98 patients (98.0%). No complications associated with IOCG occurred. In 13 (13.3%) of 98 patients, IOCG showed reflux of contrast medium into the pancreatic duct through a common channel. 'A long common channel' was observed in 8 cases (8.2%), suggesting the presence of PBM. CONCLUSION: These results suggest that IOCG in LC may be a practicable method for detecting the presence of PBM.

Adult↗
PubMed2001

Adenylyl cyclase A expression is tip-specific in Dictyostelium slugs and directs StatA nuclear translocation and CudA gene expression.

cAMP oscillations, generated by adenylyl cyclase A (ACA), coordinate cell aggregation in Dictyostelium and have also been implicated in organizer function during multicellular development. We used a gene fusion of the ACA promoter with a labile lacZ derivative to study the expression pattern of ACA. During aggregation, most cells expressed ACA, but thereafter expression was lost in all cells except those of the anterior tip. Before aggregation, ACA transcription was strongly upregulated by nanomolar cAMP pulses. Postaggregative transcription was sustained by nanomolar cAMP pulses, but downregulated by a continuous micromolar cAMP stimulus and by the stalk-cell-inducing factor DIF. Earlier work showed that the transcription factor StatA displays tip-specific nuclear translocation and directs tip-specific expression of the nuclear protein CudA, which is essential for culmination. Both StatA and CudA were present in nuclei throughout the entire slug in an aca null mutant that expresses ACA from the constitutive actin15 promoter. This suggests that the tip-specific expression of ACA directs tip-specific nuclear translocation of StatA and tip-specific expression of CudA.

Active Transport, Cell Nucleus↗
PubMed2001

An SH2-domain-containing kinase negatively regulates the phosphatidylinositol-3 kinase pathway.

SHK1 is a novel dual-specificity kinase that contains an SH2 domain in its C-terminal region. We demonstrate that SHK1 is required for proper chemotaxis and phagocytosis. Mutant shk1 null cells lack polarity, move very slowly, and exhibit an elevated and temporally extended chemoattractant-mediated activation of the kinase Akt/PKB. GFP fusions of the PH domain of Akt/PKB or the PH-domain-containing protein CRAC, which become transiently associated with the plasma membrane after a global stimulation with a chemoattractant, remain associated with the plasma membrane for an extended period of time in shk1 null cells. These results suggest that SHK1 is a negative regulator of the PI3K (phosphatidylinositol-3 kinase) pathway. Furthermore, when a chemoattractant gradient is applied to a wild-type cell, these PH-domain-containing proteins and the F-actin-binding protein coronin localize to its leading edge, but in an shk1 null cell they become randomly associated with the plasma membrane and cortex, irrespective of the direction of the chemoattractant gradient, suggesting that SHK1 is required for the proper spatiotemporal control of F-actin levels in chemotaxing cells. Consistent with such functions, SHK1 is localized at the plasma membrane/cortex, and we show that its SH2 domain is required for this localization and the proper function of SHK1.

Actins↗
PubMed2001

Operative technique on nearly total gastrectomy reconstructed by interposition of a jejunal J pouch with preservation of vagal nerve, lower esophageal sphincter, and pyloric sphincter for early gastric cancer.

Nearly total gastrectomy preserving the vagal nerve, the lower esophageal sphincter (LES), and the pyloric sphincter was developed as a function-preserving surgical technique to improve postgastrectomy disorders. In this paper, application criteria and technique are outlined, and postoperative quality of life was clinically investigated. Ten subjects who underwent this surgical operation (group A: 7 male and 3 female subjects at age 48 to 68 years with a mean age of 58.3 years) were interviewed to inquire about reflux esophagitis, dumping syndrome, and microgastria. Group A was compared with 20 cases of conventional total gastrectomy with D2 lymphadenectomy, excision of the lower esophageal sphincter (LES), total vagotomy, and single jejunal interposition (group B: 16 male and 4 female subjects at age 48 to 72 years with a mean age of 63.9 years). Included were cases with early cancer (M or SM1 of N0) localizing at the middle third and lower stomach, which was not applicable to endoscopic excision of gastric mucosa or partial gastric excision in M cancer, 2 cm or farther from the margin of the cancer to the esophagogastric mucosa cephalad junction and 3.5 cm or farther from the margin of the cancer to the pyloric caudad sphincter; in SM1 cancer, 4 cm or farther from the oral-side margin of the cancer to esophagogastric mucosa junction and 5.5 cm or farther from the anal-side margin of the cancer to the pyloric sphincter. In excision with lymph nodes, hepatic and celiac branches bifurcating from anterior and posterior trunks of the vagal nerve were preserved. To preserve LES, the esophagus was severed at the His angle at right angle to the longitudinal axis of the esophagus. The antrum was severed at 1.5 cm from the pyloric sphincter, preserving the arteria supraduodenalis. An alternative gaster was created as a 15-cm jejunal pouch with a 5-cm jejunal conduit for orthodromic peristaltic movement, using an automatic suture instrument to complete side-to-side anastomosis of folded jejunum with 1- to 1.5-cm long upper end of the pouch not anastomosed. The abdominal esophagus was mechanically anastomosed with a jejunal J pouch, and anastomosis of the pyloric antrum with a jejunal conduit was manually completed by stratum anastomosis. In group A, food ingestion per time could be taken the same as that of a healthy person, with no reflux esophagitis and dumping syndrome being noticed. Reflux esophagitis developed more significantly in group B than in group A (p < 0.05). In food ingestion per time, group B was significantly delayed compared with group A (p < 0.05). The present results suggested that the surgical technique proposed is a function-preserving gastric surgery appropriate to prevent postgastrectomy disorder of subjects.

Aged↗
PubMed2001

The role of nitric oxide (NO) in the human internal anal sphincter.

PURPOSE: Nitric oxide (NO) has recently been shown to be a neurotransmitter in nonadrenergic noncholinergic (NANC) inhibitory nerves in the human gut. To clarify the physiological significance of NO in the human internal anal sphincter (IAS), we investigated enteric nervous responses in normal IAS muscle strips above the dentate line, obtained from patients with rectal cancer. METHODS: Normal IAS muscle strips above the dentate line, obtained from ten patients who underwent rectal amputation for low rectal cancers were used. The subjects consisted of eight men and two women, aged from 46-72 years (mean age, 54.2 years). A mechanographic technique was used to evaluate in-vitro IAS muscle responses to electrical field stimulation (EFS) of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers, N(G)-nitro-L-arginine (L-NNA) and L-arginine. RESULTS: Excitatory nerves were mainly involved in the regulation of enteric nerve responses to EFS in the baseline condition of the study, and NANC inhibitory nerves acted on the normal IAS. L-NNA concentration-dependently inhibited the relaxation in response to EFS in the human IAS, and this inhibitory effect in the IAS was reversed by L-arginine. CONCLUSIONS: These findings suggest that NANC inhibitory nerves play important roles in regulating relaxation of the human IAS, and that NO plays an important role as a neurotransmitter in NANC inhibitory nerves of the human IAS.

Aged↗