Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 1,243 records · Page 69Linked to original sources

PubMedDate not supplied

Involvement of corticotropin-releasing factor in the retrieval process of fear-conditioned ultrasonic vocalization in rats.

The role of the corticotropin-releasing factor (CRF) system in the fear-conditioned ultrasonic vocalizations (USVs) induced by foot shocks in rats was investigated. In the acquisition phase of fear conditioning, the intracerebroventricular administration of CRF receptor antagonist alpha-hCRF attenuated USV responses related to context memory. Even after experiencing eight consecutive days of foot-shock challenges, the alpha-hCRF group emitted similar number of USVs as the control group if they were not given the drug. After the conditioning phase, the groups treated with alpha-hCRF or CRF receptor 1 (CRFR1) antagonist CP-154,526 emitted fewer conditioned USVs than the control group, although there was no difference in the USVs after the shock, which reflected physical stress. These results suggest that the central CRF systems, especially those mediated via CRFR1, are involved in the retrieval process, but not the acquisition or retention processes, of fear-related memory.

Animals↗

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Metabolic acidosis and renal tubular injury due to pure toluene inhalation.

A 22-y-old woman was hospitalized for muscle weakness of her lower extremities after she sniffed approximately 6 l of pure toluene during the month prior to admission. The examinations on serum and urine revealed mixed hyperchloremic and high anion gap metabolic acidosis accompanied by impaired urinary acidification. Histopathological changes of the kidney were patchy areas of tubular injury. Acidosis normalized on the fourth day of admission, but both proximal and distal tubular dysfunction persisted. These findings indicate that toluene is a tubular toxin and may contribute to the development of distal renal tubular acidosis.

Acidosis↗

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Spontaneous occurrence of vasculitis-like lesions in male reproductive tissues in mice: a histological study.

Vasculitis involving testes, epididymides, and vasa deferentia is considered to be a rare disease but has often been reported in man. In the present study, reproductive tissues of young and aged mice were examined to determine whether spontaneous vasculitis occurs in them. Testes, ductuli efferentes, epididymides, and vasa deferentia were obtained from young and aged BALB/c mice together with some nonreproductive organs for histological observation at the light microscopic level. The examination revealed that vasculitis-like lesions comparable to those in man were significantly present in the epididymides and vasa deferentia of aged but not young mice. However, no significant lesions were found in the testes and ductuli efferentes. Furthermore, other organs, such as salivary glands, thyroid glands, livers, pancreases, and kidneys, were also negative for the lesions. These results indicate that the epididymis and vas deferens are spontaneously apt to be affected by vasculitis-like lesions with advancing age, but that the lesions are not due to a systemic vasculitis disease.

Aging↗

PubMedDate not supplied

Physical interaction between lipid A and phospholipids: a study with spin-labeled phospholipids.

When mixed bilayers containing spin-labeled phosphatidylethanolamine (or phosphatidylglycerol) and Escherichia coli B lipopolysaccharide were prepared, electron spin resonance signals indicated that the patches that were initially present and contained only phospholipids or only lipopolysaccharides were unusually stable and that little lateral diffusion of phospholipids into lipopolysaccharide domains, or vice versa, took place. These results explain how the outer layer of the outer membrane, which essentially contains only lipopolysaccharides in addition to proteins, can be generated and maintained stably in bacterial cells. Furthermore, the stability of pure lipopolysaccharide domains may have important implications in the mode of action of endotoxins in the body of the host. For example, lipopolysaccharide molecules may tend to form stable domains or patches spontaneously in the animal cell membrane, and special mechanisms (such as the binding to a special receptor) may be needed to disperse the lipopolysaccharide molecules within the host cell membranes.

Lipid A↗

PubMedDate not supplied

A study of thyrotropin-releasing hormone for the treatment of spinal muscular atrophy: a preliminary report.

OBJECTIVE: To determine whether thyrotropin-releasing hormone (TRH) can increase muscle strength in children with spinal muscular atrophy types 2 and 3. DESIGN: A randomized, double-blinded, controlled, 5-wk drug trial of six subjects and three controls. Subjects and controls ranged from 4 to 8 yr of age and were randomly assigned to treatment and placebo groups in a ratio of 2:1. TRH (protirelin) or placebo was delivered intravenously through percutaneous intravenous catheters at a dose of 0.1 mg/kg (in 50 ml of normal saline) for a total of 29 days. Patients were evaluated using electromyography and handheld dynamometry of the deltoids, biceps, triceps, wrist extensors, hip flexors, quadriceps, hamstrings, and grip strength before and immediately after 5 wk of treatment. A unidirectional t test was used to compare mean values. RESULTS: Dynamometry improved significantly only for the six treated subjects (P < 0.02). Peroneal nerve conduction velocities were significantly faster in the treatment group (paired t test, P = 0.036). The parents of the treated children also provided anecdotal evidence of improvements in function. Improvements lasted 6-12 mo. CONCLUSIONS: TRH may be a useful treatment for spinal muscular atrophy. A larger, crossover design group comparison study is warranted.

Action Potentials↗

PubMedDate not supplied

Antigen non-specific tissue damage in T cell-mediated experimental autoimmune orchitis: preliminary characterization of a testis-specific T-cell line by using dermal tissue and cells.

A previous study demonstrated the establishment of a murine testicular antigen (mTA)-specific CD4+ T-cell line (designated BT.1) which was capable of transferring experimental autoimmune epididymo-orchitis to naive recipient mice. The disease transfer was antigen-specific, because no inflammatory lesion was observed in any other organs and tissues of the recipients. In this study, to investigate the local environment of BT.1 cells, the effect of the cells and their culture supernatant on a local tissue integrity was studied. When BT.1 cells were seeded on cultured fibroblastoid cell monolayers, the cells completely disrupted these monolayers in spite of the absence of the specific antigens. Moreover, the culture supernatant of BT.1 cells induced non-specific dermal inflammation when injected into skin tissue of normal syngeneic mice. Therefore, BT.1 cells were shown to devastate a tissue integrity and cause attraction and activation of inflammatory cells of the recipient origin in a local environment. These results suggest that the transferred BT.1 cells will specifically home to the testis and epididymis of recipients but the following devastation of seminiferous tubules and epididymal ducts might be non-specifically produced by the inflammatory cells of both donor and recipient origin in the lesion.

Animals↗

PubMedDate not supplied

Retroperitoneal haematoma due to ruptured microaneurysm of the pancreaticoduodenal artery.

A case of retroperitoneal haematoma due to a ruptured microaneurysm of the posterior superior pancreaticoduodenal artery in a 61 year old man is described. Ultrasonography and computed tomography revealed cystic masses near the gall-bladder. Selective coeliac angiography disclosed a microaneurysm of the posterior superior pancreaticoduodenal artery. Surgical extirpation of the cystic masses was performed, and the histological finding was an encapsulated old haematoma.

Aneurysm, Ruptured↗

PubMedDate not supplied

Laparoscopic observation of retroperitoneal cystic lymphangioma.

A case of retroperitoneal cystic lymphangioma observed laparoscopically is reported. In a 60 year old asymptomatic male patient, an 8 cm multi-loculated cystic lesion was detected incidentally near the splenic hilum with ultrasonography. Endosonography, computed tomography and magnetic resonance imaging revealed the lesion with thin wall and clear fluid. Laparoscopy showed a thin-walled cyst with smooth surface, and straw-coloured clear fluid was observed through the wall. These findings suggested benign aetiology, and seemed to be characteristic of cystic lymphangioma. The tumour was resected, and microscopic examination showed proliferated lymph channels intespersed by lymph follicles. Diagnosis of cystic lymphangioma was established. Laparoscopy seems a useful pre-operative method.

Humans↗

PubMedDate not supplied

Outcome of patients with early ovarian cancer undergoing three courses of adjuvant chemotherapy following complete surgical staging.

We conducted the present study to determine the outcome of patients with early ovarian cancer who underwent three courses of adjuvant chemotherapy after complete surgical staging. One hundred consecutive patients with stage I-II epithelial ovarian cancer who had undergone complete surgical staging and received three courses of platinum-based chemotherapy were entered in this study. Twenty-one patients were low risk, defined as stage IA-B, grade 1 and histologic types except for clear cell adenocarcinoma, and remaining 79 were high risk. All patients with stage IA or IB, whatever histologic type and histopathologic grade, were alive without disease. The 5-year survival rate was 89.4% for patients with stage IC and 76.2% for those with stage II. The 5-year survival rate for low- and high-risk patients was 100% and 89.4%, respectively. The survival rate for grade 1 was significantly better than that for grade 2 or 3. Multivariate analysis revealed that histologic grade was an independent prognostic factor in stage IC-II ovarian cancer. The outcome of patients with early ovarian cancer undergoing three courses of chemotherapy after complete surgical staging was favorable even in high-risk patients.

Adenocarcinoma↗

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Acceleration of gastric ulcer healing by omeprazole in portal hypertensive rats. Is its action mediated by gastrin release and the stimulation of epithelial proliferation?

BACKGROUND: Gastric ulcer healing is delayed in patients with portal hypertension (PHT) and often responds poorly to histamine H(2) blockers. Although proton pump inhibitors are more effective anti-ulcer agents, there is little information regarding their efficacy for gastric ulcer in cases of PHT. Therefore, we investigated the effects of a proton pump inhibitor, omeprazole, on the healing of acetic-acid-induced gastric ulcer in PHT rats. METHODS: Animals studied were 80 male Sprague-Dawley rats aged 7 weeks, of which half underwent two-staged portal vein ligation (PHT rats) and half underwent a sham operation (SO rats). Gastric ulcers were induced by acetic acid. Starting from day 4 after ulcer induction, rats received omeprazole or vehicle orally (50 mg/kg) for 5 or 10 days. Ulcer area, proliferating cell nuclear antigen labelling index (PCNA LI), and serum gastrin levels were recorded. RESULTS: PHT significantly inhibited epithelial cell proliferation and delayed gastric ulcer healing as indicated by a decreased PCNA LI at the ulcer margin and almost 2-fold larger ulcer area in PHT versus SO rats 14 days after ulcer induction. Ten-day treatment with omeprazole (vs. vehicle) significantly accelerated ulcer healing to a similar extent in both PHT and SO rats. Serum gastrin levels were significantly higher in PHT rats than in SO rats following treatment with omeprazole. Omeprazole (vs. vehicle) restored the decreased PCNA LI at the ulcer margin in PHT rats to that noted in SO rats. CONCLUSIONS: In PHT rats, omeprazole accelerates gastric ulcer healing, stimulates epithelial cell proliferation at the ulcer margin, and increases serum gastrin levels. Since gastrin is a potent stimulator of gastric epithelial cell proliferation, increased serum gastrin levels may be an important factor in omeprazole-induced stimulation of epithelial cell proliferation and acceleration of gastric ulcer healing in conditions of PHT.

Acetic Acid↗

PubMedDate not supplied

Induction of the renal pelvic and ureteral carcinomas by N-butyl-N-(4-hydroxybutyl)nitrosamine in SD/cShi rats with spontaneous hydronephrosis.

We attempted to establish an animal model for renal pelvic and ureteral carcinomas. In Experiment 1, Sprague-Dawley (SD)/cShi and SD/gShi strains of male and female rats and Fischer-344 (F-344)/DuCrj and LEW/Crj strains of male rats, 6 wk old, were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) for 12 wk and then treated without chemical for 10 wk. Only the SD/cShi strain, which has spontaneous hydronephrosis and hydroureter, showed high incidences of carcinomas in the renal pelvises and ureters, whereas the other strains did not. In Experiment 2, SD/cShi and Crj:CD strains of male and female rats, 6 wk old, were exposed to 0.05% BBN for 20 wk. Both sexes of SD/cShi rats had high incidences of bilateral carcinomas in renal pelvises and/or ureters associated with urinary bladder carcinomas, whereas both sexes of Crj:CD rats had urinary bladder tumors only. These results indicate that the SD/cShi strain may be a suitable animal for the induction of renal pelvic and ureteral carcinomas that appear to depend on urine stagnation secondary to hydronephrosis and hydroureter.

Animals↗

PubMedDate not supplied

Calmodulin regulates nucleotide hydrolysis activity of tissue transglutaminase.

The interaction of calmodulin with purified guinea pig liver transglutaminase was studied. The nucleotide (ATP and GTP) hydrolysis activity of this tissue transglutaminase was transiently increased and then gradually decreased depending on calmodulin concentration. The peak activation was obtained in the presence of a stoichiometric amount of calmodulin. The effect of calmodulin on the classical transglutaminase activity was minimal. Fluorescence spectroscopy demonstrated that the enzyme produced a significant blue shift in the emission peak of dansylated calmodulin. Interestingly, Ca2+ was not required for the interaction between the two proteins. The results described here give an additional regulatory role to calmodulin.

Adenosine Triphosphate↗

PubMedDate not supplied

Nuclear translocation of tissue type transglutaminase during sphingosine-induced cell death: a novel aspect of the enzyme with DNA hydrolytic activity.

Tissue type (type 2) transglutaminase (TGase, EC 2.3.2.13) has been implicated in various cellular processes including cell death. In order to better understand the role of this enzyme in cell death, human melanocytic A375-S2 cells were treated with sphingosine, a cell-signaling mediator. During the rapid onset of cytotoxicity caused by this lipidic agent, tissue TGase was translocated from the cytoplasm to the cell nuclei. This observation was further remarked in relevance to its previously undescribed activity for DNA degradation. The DNA hydrolytic activity associated with tissue TGase was dependent on Mg2+ in contrast to the Ca2+ requirement for the classical cross-linking activity of TGase, and was inhibited by Zn2+. Based on the results shown here, we propose a novel aspect of tissue TGase in cell death.

Cell Death↗

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Immunohistological localization of autoantigens detected by serum autoantibodies from mice with experimental autoimmune orchitis without using adjuvants.

Recently, a murine model of testicular autoimmunity was produced in mice by subcutaneous injections with viable syngeneic testicular germ cells alone, without depending on the use of any adjuvants or immunopotentiators. In this article, histological localization of autoantigens detected by circulating autoantibodies was immunohistochemically studied by reacting the immune sera with frozen sections of testes from mice of various ages. The study showed that the reactivity of immune sera was detected in the testis sections of normal mice older than 24 days of age but not in those of mice younger than 20 days of age. The immunostain was detected at proacrosomal, acrosomal, and other cytoplasmic regions of variously shaped developing spermatids but never on pachytene spermatocytes, basal compartment germ cells, or the supporting tissue of the seminiferous tubules.

Adjuvants, Immunologic↗

PubMedDate not supplied

Histopathology of the seminiferous tubules in mice injected with syngeneic testicular germ cells alone.

Previously, a model of murine experimental autoimmune orchitis was produced by active immunization with viable syngeneic testicular germ cells without resorting to any adjuvants. The histological mode of the spermatogenic disturbance of this autoimmunity was investigated in A/J mice. A significant spermatogenic disturbance was consistently induced after the appearance of inflammatory cell responses around the tubuli recti. It first appeared seminiferous epithelium adjacent to the tubuli recti, then spread to the peripheral epithelium. The histopathology of the seminiferous tubules in the early phase ranged from partial degeneration and depletion of all kinds of germ cells to complete loss of germ cells other than some remaining spermatogonia, while both Sertoli cells and the basal lamina of the tubules appeared intact. In the late phase, depletion of Sertoli cells, disorganization of the seminiferous tubular wall or filling with many round-shaped degenerating germ cells, appearance of malformed spermatids with signet ring nuclei, depletion of immature germ cells with remaining elongated spermatids, or complete loss of the seminiferous epithelium were observed in addition to the early histopathological features.

Animals↗

PubMedDate not supplied

Spermatic granulomata are experimentally induced in epididymides of mice receiving high-dose testosterone implants. I. A light-microscopical study.

It is known that a spermatic granuloma is induced by the inflammatory reaction following leakage of spermatozoa outside the germ cell ducts and is the main clinical complication of vasectomy. In the present study, we found that spermatic granulomata were experimentally induced in the epididymides of mice treated with high-dose testosterone. Testosterone powder (0.02, 0.2, or 2 mg per gram body weight) was implanted into ICR male mice, which were then killed from 7 to 63 days after the treatment for histological examination at the light-microscopic level. The results showed that the testis exhibited little or no degenerative change; however, the epididymides were frequently affected by spermatic granulomata after day 35 in mice implanted with high-dose testosterone (2 but not 0.2 or 0.02 mg per gram body weight). Observation of the early histological changes revealed that the ductal epithelium of the epididymides became vacuolated around day 25. Thereafter, the basement membrane of the epididymal ducts was ruptured after day 30, followed by leakage of spermatozoa into the adjacent interstitial tissue. The extravasated spermatozoa were then surrounded by macrophages (= epithelioid cells) and lymphocytes, resulting in the formation of a spermatic granuloma. In contrast, other mice treated with the same dose of deoxycorticosterone or estradiol did not show the induction of spermatic granulomata. Therefore, this study demonstrated that a spermatic granuloma is specifically formed in the epididymis by testosterone and that the lesion is started by vacuolation of the epididymal duct epithelium.

Animals↗

PubMedDate not supplied

Successful transcatheter embolization of a pancreaticoduodenal artery aneurysm in association with celiac axis occlusion: a case report.

We report a case of a pancreaticoduodenal artery (PDA) aneurysm in association with celiac axis occlusion. A 54 year-old female complaining of abrupt onset of abdominal pain was admitted to our hospital. On admission, abdominal CT examination revealed a hematoma in the retroperitoneal space. Selective superior mesenteric artery (SMA) angiography disclosed an aneurysm in the anterior inferior pancreaticoduodenal artery (AIPDA). The celiac axis was occluded and blood was flowing to the liver and spleen via the enlarged pancreaticoduodenal arcade from the SMA. Transcatheter embolization of the aneurysm was performed successfully. Up to 1996, there have been 37 reported cases of PDA aneurysm in association with celiac axis stenosis or occlusion, including this one. Transcatheter embolization was performed successfully in only 5 of these cases. The formation of this type of PDA aneurysm is thought to be a result of the increased blood flow in the pancreaticoduodenal arcade due to celiac axis stenosis or occlusion. The transcatheter embolization performed in our report produced a far greater blood flow, which may lead to further aneurysmal formation. Careful follow-up is therefore necessary.

Aneurysm↗

PubMedDate not supplied

Effects of nafamostat mesilate, a synthetic protease inhibitor, on immunity and coagulation after hepatic resection.

BACKGROUND/AIMS: Effects of nafamostat mesilate (NM), a serine protease inhibitor, on both coagulation-fibrinolysis activity and post-operative changes in immune responsiveness were investigated in a clinical study of 20 patients who underwent an extensive hepatic resection. METHODOLOGY: The patients were randomly allocated into 2 groups of 10 patients each: The NM group was administered nafamostat mesilate (2 mg/kg/day) during and after the operation for 7 days. The control group received standard post-operative intensive therapies except NM. RESULTS: The post-operative increase in coagulation in the control group was significantly suppressed in the NM-treated group on post-operative day (POD) 7. Natural killer (NK) activity, which was impaired after the operation, was recovered in the NM group on POD 7 and was significantly higher than in the control group. Helper/suppressor ratios of T lymphocytes were significantly increased post-operatively by the administration of NM. CONCLUSIONS: These results demonstrate that NM controls the enhanced coagulation which occur in patients with extensive hepatic resection. It is also suggested that NM promptly restores the impaired immune responsiveness and decreases the risk of post-operative complications, as well as the risk of recurrence in patients with hepatic tumors.

Antifibrinolytic Agents↗