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Biomedical subjects

Y Eguchi

Publications and source records attributed to Y Eguchi.

At least 19 recordsLinked to original sources
PubMed2001

Cellular distribution of thrombomodulin as an early marker for warm ischemic liver injury in porcine liver transplantation: protective effect of prostaglandin I2 analogue and tauroursodeoxycholic acid.

BACKGROUND: Warm ischemia of the graft from non-heart-beating donors is considered a risk factor for posttransplant graft dysfunction. The early administration of cytoprotective agents may help improve graft dysfunction. METHODS: Four groups of 10 pigs each underwent orthotopic liver transplantation. Prostaglandin I2 analogue, OP-41483, was administered intraportally 30 min before warm ischemic insult in donors and after reperfusion in recipients in one group. In the other study group, additional intravenous tauroursodeoxycholic acid (TUDC) was given before the warm ischemic insult in donors and after reperfusion, then maintained continuously until postoperative day (POD) 7. RESULTS: Exposure of liver grafts to warm ischemia resulted in severe congestion with the disappearance of thrombomodulin (Tm) from the sinusoidal endothelial cells (SECs) and smooth muscle cells (SMCs) around biliary epithelial cells (BEpCs) 2 hr after reperfusion, followed by positive immunoreactivity of Tm in BEpCs with hyperbilirubinemia, which was related to high mortality. Combined administration of OP-41483 and TUDC had a protective effect, demonstrated by sustained immunoreactivity of Tm from SECs and SMCs until POD 7, without that reactivity in BEpCs. This was associated with reduced congestion and hyperbilirubinemia, similar to the control group not subjected to warm ischemia. CONCLUSIONS: These findings suggest that negative immunoreactivity of Tm in SECs and SMCs surrounding BEpCs and positive in BEpCs may be an early marker for ischemic liver injury, and that OP-41483 and TUDC may protect against the microcirculatory and biliary derangement.

Animals↗
PubMed2001

Vascular smooth muscle maintains the levels of Bcl-2 in endothelial cells.

Endothelial cells (ECs) play important roles in maintaining vascular homeostasis. Therefore, dysregulation of EC apoptosis may be involved in the mechanism of atherogenesis. Since recent evidence has shown that vascular endothelial growth factor (VEGF), an EC-specific growth factor, is released from vascular smooth muscle cells (VSMCs), we examined whether VSMCs can modulate EC apoptosis using a coculture system. Incubation of ECs with high levels of nitric oxide (NO) released by N-ethyl-2-[1-ethyl-2-hydroxy-2-nitrosohydrazino]-ethanamine, a NO releasing agent, resulted in apoptosis in association with decreased levels of Bcl-2, and increased levels of Bax, an accelerator of aoptosis. Exogenously added VEGF partially inhibited apoptosis and alterations of these bcl-2 family proteins induced by NO. On the other hand, NO-induced apoptosis and down-regulation of Bcl-2 in ECs were almost completely inhibited by coculturing with VSMCs. However, these inhibitory effects by VSMCs were suppressed by a neutralizing antibody against VEGF. In addition, overexpression of Bcl-2 prevented from NO-induced apoptosis in ECs. These findings indicate that VSMCs protect ECs from NO-induced apoptosis through inhibiting down-regulation of Bcl-2. Thus, vascular smooth muscle which releases EC survival factors including VEGF may play important roles in maintaining the levels of Bcl-2 in ECs.

Apoptosis↗
PubMed2001

Effects of profound hemodilution on small-intestinal wound healing in rabbits.

BACKGROUND: Wound healing is influenced by tissue oxygen tension and blood perfusion, but not by moderate anemia or hemodilution. The effect of perioperative profound hemodilution on small-intestinal wound healing remains unclear. METHODS: We performed jejunectomy followed by end-to-end anastomosis in rabbits subjected to a variety of perioperative hemodilutions: HD((HES)), hemodiluted with hydroxyethylstarch; HD((P+HES)), hemodiluted with autologous plasma and hydroxyethylstarch; HD((HES))/R, hemodiluted with hydroxyethylstarch and retransfused afterward. Intraoperative hemoglobin levels were 5 g 100 ml(-1). On Postoperative Day 5, the tensile strength (TS) of the anastomosis was measured and histological specimen was obtained. The time courses of hemoglobin, serum albumin (Alb), plasma fibrinogen (Fbg), and plasma activity of factor XIII (F XIII) were measured. RESULTS: TS in HD((HES))/R (236.0 +/- 52.2 gf) was similar to that in control (266.5 +/- 41.6 gf); however, TS in HD((HES)) (179.8 +/- 17.9 gf) and HD((P+HES)) (165.5 +/- 14.7 gf) decreased significantly. The histological findings in HD((HES))/R were similar to those of control, whereas they demonstrated a delayed healing process in HD((HES)) and HD((P+HES)). Hemoglobin levels were still lower on Postoperative Day 5 in HD((HES)) and HD((P+HES)), but increased to 10.0 g 100 ml(-1) after retransfusion in HD((HES))/R. Hemodilution caused significant decreases in Alb, Fbg, and F XIII, but the values after retransfusion in HD((HES))/R were similar to postoperative values in HD((P+HES)). CONCLUSION: Intraoperative profound hemodilution does not interfere with small-intestinal wound healing as long as postoperative hemoglobin levels were maintained above 10 g 100 ml(-1). Postoperative levels of other plasma constituents may not influence wound healing.

Anastomosis, Surgical↗
PubMed2001

Amino acid sequence of Kalinowaski's Tinamou (Nothoprocta kalinowskii) hemoglobin and the rate of evolution of bird alphaD-globin.

Two hemoglobin components are recognized in erythrocytes of the adult Tinamou. We determined the amino acid sequences of Tinamou alphaD-, alphaA-, and beta-globins from intact globin chains and several chemically cleaved fragments. A remarkable feature of Tinamou hemoglobin was a deletion in the alphaD-globin chain. This has not been reported in the literature, except in pigeon embryonic alphaD-globin. The amino acid sequences of Tinamou globin were highly similar to those of Ostrich and Rhea hemoglobin. Comparison between Tinamou, Ostrich, and Rhea that suggested the evolution speed of globin, alphaD = alphaA > beta, was related with the early appearance birds. The important residues in Tinamou hemoglobin as the heme contact and oxygen binding regions were highly conserved in other species.

Amino Acid Sequence↗
PubMed2001

Development of a system for the inference of large scale genetic networks.

We propose a system named AIGNET (Algorithms for Inference of Genetic Networks), and introduce two top-down approaches for the inference of interrelated mechanism among genes in genetic network that is based on the steady state and temporal analyses of gene expression patterns against some kinds of gene perturbations such as disruption or overexpression. The former analysis is performed by a static Boolean network model based on multi-level digraph, and the latter one is by S-system model. By integrating these two analyses, we show our strategy is flexible and rich in structure to treat gene expression patterns; we applied our strategy to the inference of a genetic network that is composed of 30 genes as a case study. Given the gene expression time-course data set under the conditions of wild-type and the deletion of one gene, our system enabled us to reconstruct the same network architecture as original one.

Algorithms↗
PubMed2001

[Disseminated bone marrow metastases from gastric cancer: detection and monitoring the effectiveness of chemotherapy by bone marrow scintigraphy].

Disseminated bone marrow metastasis of cancer is a critical condition, frequently complicated by disseminated intravascular coagulation (DIC). A 32-year-old man with gastric cancer was diagnosed as having disseminated bone marrow metastases. Bone scintigraphy demonstrated many abnormal radionuclide accumulations in the whole body. Bone marrow aspiration revealed cancer cells. Bone marrow scintigraphy with 111In-Cl3 demonstrated central marrow failure and peripheral expansion. The remission of DIC was observed after sequential methotrexate and 5-FU therapy, then uptake of radionuclide in the central bone marrow was remarkably improved by bone marrow scan. After thirteen anti-cancer chemotherapies, recurrence of DIC was suspected because of the reduction of blood platelet count. Nevertheless, repeated bone marrow scan still demonstrated the central bone marrow clearly. The patient discharged from our hospital without the recurrence of DIC. We considered bone marrow scintigraphy is useful in the detection of disseminated bone marrow metastases of cancer and monitoring the effectiveness of chemotherapy.

Adult↗
PubMed2000

A novel protein, RTN-XS, interacts with both Bcl-XL and Bcl-2 on endoplasmic reticulum and reduces their anti-apoptotic activity.

Bcl-2 and Bcl-XL serve as critical inhibitors of apoptosis triggered by a broad range of stimuli, mainly acting on the mitochondria. We identified two members of the reticulon (RTN) family as Bcl-XL binding proteins, i.e., NSP-C (RTN1-C) and a new family member, RTN-XS, both of which did not belong to the Bcl-2 family and were predominantly localized on the endoplasmic reticulum (ER). RTN-XS interacted with both Bcl-XL and Bcl-2, increased the localization of Bcl-XL and Bcl-2 on the ER, and reduced the anti-apoptotic activity of Bcl-XL and Bcl-2. On the other hand, NSP-C interacted only with Bcl-XL, affected the localization of Bcl-XL, and reduced Bcl-XL activity, but had no effect on Bcl-2. These results suggest that RTN family proteins can modulate the anti-apoptotic activity of Bcl-XL and Bcl-2 by binding with them and can change their localization to the ER.

Amino Acid Sequence↗
PubMed2000

A monoclonal antibody specific to the granulocyte-derived elastase-fragment D species of human fibrinogen and fibrin: its application to the measurement of granulocyte-derived elastase digests in plasma.

When granulocytes are stimulated under certain clinical conditions, elastase is released therefrom and digests fibrin(ogen) independently of the plasmin system, which may also be mobilized simultaneously. Thus, discrimination of these 2 systems becomes urgent for the diagnosis and treatment of the underlying diseases. Using as immunogen a 97-kd granulocyte-elastase digest of human fibrinogen, we raised an antibody IF-123 that specifically recognizes elastase digests of human fibrin(ogen). The 97-kd elastase fragment resembles plasmic fragment D(1), and the epitope of this antibody is located on the Aalpha (196-204) residue segment. This segment appears to be masked in fibrin(ogen) but exposed when the Aalpha Leu 204-Ile 205 peptide bond is cleaved by elastase. Cathepsin G concomitantly released from granulocytes failed to expose the epitope. By an enzyme immunoassay using IF-123 as the capture antibody, the elastase digests of fibrin(ogen) can be measured in plasma samples without interference by abundantly coexisting fibrinogen. Indeed, we found that the elastase digests were mostly elevated in patients with inflammation or malignant tumors, but remained in a normal range in patients with a benign gastrointestinal tract disease such as duodenal ulcer and polyps in the gallbladder or the colon. Like the plasmic D-dimer, the elastase digests predominantly consisted of the DD/E complex and DD/E-containing high-molecular weight derivatives apparently corresponding to the phase-3 plasmic digests of cross-linked fibrin. (Blood. 2000;95:1721-1728)

Amino Acid Sequence↗
PubMed2000

Protease inhibitor reduces loss of tensile strength in rat anastomosis with peritonitis.

BACKGROUND: The tensile strength in intestinal anastomoses decreases postoperatively in association with degradation of the extracellular matrix, and these changes would be expected to be more intense in the presence of peritonitis. MATERIALS AND METHODS: In this study, we investigated extracellular matrix degradation and tensile strength in a rat model of intestinal anastomosis with peritonitis. In the chemical peritonitis model, peritonitis was induced 24 h earlier with intraperitoneal HCl. A serine protease inhibitor, nafamostat mesilate (NM), was given intraperitoneally to some animals every 12 h from immediately after the operation for 3 days. Immunostaining was performed by the standard streptavidin-biotin-peroxidase method after fibronectin (Fn) and factor XIII antigen retrieval on paraformaldehyde-fixed, paraffin-embedded tissue sections. RESULTS: In comparison with controls, administration of NM reduced the loss of tensile strength on Day 3 in a dose-dependent manner, and high-dose NM (20/mg/kg) significantly prevented the loss of tensile strength on Day 3 (P < 0. 05). In the control group, degradation of the collagen layer in the anastomosis was associated with disappearance of Fn and factor XIII staining on Day 3. The administration of NM attenuated these changes with intense immunostaining for Fn and factor XIII seen particularly between collagen fibers on both sides of the anastomosis on Day 3. In the chemical peritonitis model, administration of NM also significantly prevented the loss of tensile strength on Day 3 without disappearance of collagen fibers. CONCLUSION: These findings suggest that NM may be clinically useful for preventing intestinal leakage, particularly when anastomoses are performed under protease-activating conditions, such as intestinal edema and inflammation.

Anastomosis, Surgical↗
PubMed2000

Intubating laryngeal mask for fibreoptic intubation--particularly useful during neck stabilization.

PURPOSE: To assess the ease of fibrescope-assisted tracheal intubation while the patient's head and neck were placed in the neutral or the manual in-line position, and to determine if the intubating laryngeal mask facilitated fibreoptic intubation in these positions. METHODS: In 84 patients, the patient's head and neck were placed in the neutral position (pillow placed under occiput), and in another 40 patients the head and neck were stabilized by the manual in-line method (no pillows under occiput). In both groups, after induction of anesthesia with 2.0-2.5 mgxkg(-1) propofol, 50-100 microg fentanyl and 1.0 mgxkg(-1) vecuronium, patients were allocated randomly into two groups: in Group C tracheal intubation was attempted using only a fibrescope, whereas in Group L fibreoptic intubation through the intubating laryngeal mask was attempted. RESULTS: In group C the success rate of fibreoptic tracheal intubation within two minutes was higher in the neutral position (31 of 42 patients (73%)) than in the manual in-line position (8 of 20 patients (40%)). In contrast, in group L the success rate was similar between the two positions. Tracheal intubation was easier in group L than in group C (P < 0.01 or 0.001) and the time for intubation was shorter in group L than in group C in both head and neck positions. CONCLUSIONS: Fibreoptic tracheal intubation was more difficult in the manual in-line position than in the neutral position. The intubating laryngeal mask facilitated fibreoptic intubation in both positions.

Anesthesia, Inhalation↗
PubMed2000

Cellular distribution and clinical value of urokinase-type plasminogen activator, its receptor, and plasminogen activator inhibitor-2 in esophageal squamous cell carcinoma.

To assess the participation of the plasminogen activation system in the invasiveness of esophageal squamous cell carcinoma, we performed immunohistochemistry and in situ hybridization to study the distribution of a urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR), and plasminogen activator inhibitor-2 (PAI-2). u-PA and PAI-2 were expressed heterogeneously in cancer cells, and restricted expression was found in stromal cells, especially fibroblasts, that were located in the immediate proximity of the cancerous cells. u-PAR was found only in cancer cells located at the periphery of tumors. Compared with patients with u-PA-negative cancer cells, patients with u-PA-positive cancer cells more frequently showed a neoplastic invasion beyond the muscularis propria and lymph node metastases. They also showed a significantly shorter 5-year overall survival. Patients with PAI-2-positive fibroblasts showed significantly lower levels of local invasiveness, represented by a neoplastic invasion beyond the muscularis propria, than those who were PAI-2 negative. Our results suggest that the expression of u-PA in esophageal squamous cell carcinoma is predictive of poor survival, whereas the expression of PAI-2 in the fibroblasts surrounding them is protective. An analysis of u-PA and PAI-2 expression in cancer cells and their surrounding fibroblasts may be useful for predicting the prognosis of patients with esophageal squamous cell carcinoma.

Adult↗
PubMed2000

Habutobin recognizes Thr(7) in the sequence of fibrinopeptide A of rabbit fibrinogen.

Habutobin, a thrombin-like enzyme from Trimeresurus flavoviridis venom, cleaves only the Arg(16)-Gly(17) bond in the rabbit Aalpha chain and releases fibrinopeptide A (FPA). To investigate the role of amino acid residues in the rabbit FPA sequence upon habutobin action, we examined the inhibitory effects of FPA and peptides containing partial sequences of FPA on the habutobin action. Fibrinopeptides from rabbit, human, bovine and dog were isolated and rabbit FPA was fragmented using dilute HCl. Rabbit FPA inhibited the action of habutobin although FPA from human, bovine and dog did not. Among the fragments of rabbit FPA, a heptapeptide Aalpha 3-9, the N-terminal region of rabbit FPA, competitively inhibited the release of FPA by habutobin, whereas the C-terminal hexapeptide of FPA (Aalpha 11-16) exerted no effect on the habutobin action. Synthetic tripeptides Ser-Thr-Phe corresponding to Aalpha 6-8 and Ala-Thr-Phe also inhibited the habutobin action, but Ser-Asp-Phe and Ala-Thr-Gly did not. It is concluded that habutobin would recognize the region around Thr(7)-Phe(8) in the sequence of rabbit FPA (Aalpha 1-16) prior to the cleavage of the Arg(16)-Gly(17) bond.

Amino Acid Sequence↗
PubMed2000

Amino acid sequences of hemoglobin from guinea fowl (Numida meleagri) and California quail (Lophortyx californica) with phylogenetic analysis of major groups of Galliformes.

We determined the complete amino acid sequences of the hemoglobin of two species, guinea fowl and California quail, in Galliformes from intact globin chain and chemical cleavage fragments in order to analyze the molecular evolution of hemoglobin for the classification of Galliformes. Galliformes have two types of hemoglobin components, HbA and HbD, which consist of identical beta chain and different alpha chains. The sequences are similar to globin chains of Galliformes reported previously. These sequences were compared with those of other Galliformes (Phasianidae, Meleagrididae) using duck and goshawk as out-groups. The phylogenetic tree of major groups of Galliformes based on hemoglobin was similar to the tree model produced based on the amino acid sequence of lysozyme c.

Amino Acid Sequence↗
PubMed2000

Regions essential for the interaction between Bcl-2 and SMN, the spinal muscular atrophy disease gene product.

The SMN gene is implicated in spinal muscular atrophy (SMA), and its product has been shown to interact with Bcl-2 protein to enhance its anti-apoptotic activity. In this study, we determined the regions that were essential for the interaction of Bcl-2 and SMN by co-immunoprecipitation of deletion mutants. Bcl-2 lacking its amino-terminal 20 amino acid residues or its carboxyl-terminal membrane-anchoring domain showed no or greatly reduced binding with SMN, respectively. However, Bcl-2 lacking other regions could still bind to SMN. Because Bcl-2 lacking the membrane-anchoring domain could bind to SMN in a yeast two-hybrid system, the amino-terminal region of Bcl-2 seems to be the most important domain for binding with SMN. A fragment of SMN encoded by exon 6 could bind to Bcl-2, but SMN lacking this region could not. From these results, we concluded that Bcl-2 and SMN proteins bound with each other at the amino-terminal region near the BH4 domain of Bcl-2 and the region encoded by exon 6 of SMN, both regions known to be important for their function.

Amino Acid Sequence↗
PubMed2000

Isolated pericardial effusion and transient abnormal myelopoiesis in a fetus with Down's syndrome.

Isolated pericardial effusion was detected in a fetus at 34 weeks of gestation. A male infant weighing 2,044 g was born by cesarean section because of a non-assuring fetal heart rate pattern at 35 weeks of gestation. Transient leukocytosis (36,100/microl) with 49% blast cells was seen in this neonate. The infant's karyotype was 47, XY + 21. The pericardial effusion disappeared after treatment with prednisolone at a dose of 2 mg/kg/day. Hypothyroidism was subsequently found. Thus, the subject patient with Down's syndrome developed isolated pericardial effusion, transient abnormal myelopoiesis (TAM), and hypothyroidism. Because more than 20% of the infants with TAM and Down's syndrome develop acute nonlymphocytic leukemia in early childhood, he is being closely observed.

Adult↗
PubMed2000

Effect of follicle-stimulating hormone on sertoli cell division in cultures of fetal rat testes.

The present study was performed to determine when follicle-stimulating hormone (FSH) begins to promote Sertoli cell division in fetal rats, and to determine whether the effect of FSH is mediated by cAMP-dependent protein kinase (PKA). When testes from 15- to 17-day fetuses were cultured with or without FSH for 48 h, FSH did not promote Sertoli cell division in 15-day testes, but did in 16- and 17-day testes. Anti-rat FSH was injected into 16-day fetuses in utero. Twenty-four hours later, the testes of the injected fetuses and those of their intact littermates were cultured with or without FSH for 48 h. Without FSH, the Sertoli cell division index was significantly lower in anti-FSH-treated fetuses than in intact fetuses. With FSH, however, the index increased. When PKA inhibitor was added to cultures of 16-day testes with FSH, the promotion of Sertoli cell division by FSH was inhibited. We conclude that between 16 and 17 days of gestation, fetal pituitary FSH stimulates the division of Sertoli cells by activating the PKA activity.

Animals↗
PubMed2000

Necrotizing myopathy in a patient with chronic hepatitis C virus infection: a case report and a review of the literature.

We describe a 61-year-old man presenting with necrotizing myopathy associated with chronic active hepatitis due to hepatitis C virus (HCV) infection. Thirteen patients with HCV-associated myopathy have been reported previously. In most of these cases, varying degrees of inflammatory changes were observed in the muscle tissue. In 2 patients, myopathy developed after initiation of interferon therapy for chronic HCV hepatitis. Our case was unusual due to long-standing elevation of creatine kinase values which improved following interferon therapy and the non-inflammatory features of the muscle tissue where the HCV RNA minus strand, a marker for replicative intermediates of the virus, was undetectable. The association of myopathy with HCV infection might represent a unique clinical entity, although the underlying pathological mechanisms remain unknown.

Biopsy↗