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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 415 records · Page 23Linked to original sources
PubMed1994

Phasic secretion of newly synthesized atrial natriuretic factor from unstimulated atrial myocytes in culture.

We have examined kinetics and composition of newly synthesized proteins secreted from cultured atrial myocytes from adult rats. Under unstimulated conditions, noncontracting cultured atrial myocytes, which were pulse-labeled for 10 minutes with [35S]methionine, rapidly released a considerable portion of newly synthesized atrial natriuretic factor (ANF) in a phasic secretion with a peak at 40 to 80 minutes of chase time. The phasic secretion almost ceased after 80 minutes of chase, after which relatively slow release of the hormone was observed. The ability to stimulate the phasic secretion with secretagogues and a marked resemblance of the radiochemical composition of released proteins in the unstimulated phasic secretion to that in stimulated secretion suggest that the proteins discharged from the cells during the phasic secretion might be derived from secretory granules. Examination of the quantitative change of intracellular ANF showed that approximately 60% of newly synthesized labeled ANF was still retained in the cells after the termination of the phasic secretion, indicating that the termination of the phasic secretion was not due to depletion of the labeled protein in the cells. These results suggest that a proportion of newly synthesized ANF was rapidly released from the unstimulated atrial myocytes via a secretory route that shares certain features with both the regulated and the constitutive secretory pathway and that a part of newly synthesized ANF is processed for rapid release while the remainder is destined for slow release or storage within the cells.

Amino Acid Sequence↗
PubMed1994

Functional difference between Ad4BP and ELP, and their distributions in steroidogenic tissues.

Ad4BP, a zinc finger DNA-binding protein, was identified as a transcription factor regulating steroidogenic P-450 genes in a cAMP-dependent manner. Immunochemical and immunohistochemical studies with steroidogenic tissues, adrenal, ovary, and testis, were performed using the antiserum to Ad4BP. Ad4BP was expressed to the same extent in the three zones of the adrenal cortex. Immunohistochemical examination of ovarian follicle and corpus luteum showed the expression of Ad4BP. The granulosa and thecal cells, the two distinct types of the steroidogenic cells in the follicle, gave Ad4BP signals, which were stronger than in the latter cells than in the former. Immunoblot analyses of mature and regressed corpora lutea indicated a parallel expression of Ad4BP and side-chain cleavage P-450, and both proteins significantly decreased in the regressed tissues. Leydig cells surrounding seminiferous tubules gave clear immunostaining signals for Ad4BP. ELP, a mammalian counterpart of Drosophila FTZ-F1 detected in EC cells, and are isoforms transcribed from the same gene. The Ad4BP and ELP forms recognize same nucleotide sequences. Reverse transcriptase-polymerase chain reaction with specific primers for ELP revealed that steroidogenic tissues contained ELP as well as Ad4BP. The effects of the two proteins on the transcription of the CYP11B gene were compared using the expression vectors of Ad4BP and ELP. ELP did not activate transcription and showed a weak inhibitor effect on the Ad4BP-dependent transactivation of the CYP11B gene promoter when transfected simultaneously. A gel shift analysis using in vitro synthesized Ad4BP and ELP revealed that the binding activity of ELP is significantly weaker than that of Ad4BP.

Adrenal Cortex↗
PubMed1994

Enhancement of phorbol ester-induced production of tumor necrosis factor-alpha by 2,6-dimethylphenylphthalimide.

The effect of phenyl- and benzylphthalimide analogs on tumor necrosis factor (TNF)-alpha production by a human leukemia cell line, HL-60, stimulated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) was investigated. Though non-substituted phenyl- and benzyl-phthalimide had no effect on TNF-alpha production after TPA-induction, introduction of methyl group(s) onto the phenyl group resulted in the appearance of potent enhancing activity on TNF-alpha production.

Cell Division↗
PubMed1994

Substrates and inhibitors of antiseptic resistance in Staphylococcus aureus.

The range of substrates of antiseptic resistance associated with the ebr gene is very wide and includes antiseptics, DNA-intercalating drugs and preservatives which have no quaternary ammonium group in methicillin-resistant Staphylococcus aureus. Antiseptic resistance was inhibited by calcium channel blockers and calmodulin inhibitors similarly to the resistance to multiple antitumor agents encoded by the mdr gene in human cells. These results show that the common properties of the mdr gene and the ebr gene may be shared by the mechanisms that are involved in the removal of toxic substances from the cell.

Anti-Infective Agents, Local↗
PubMed1994

[Experimental and clinical studies on ischemic lesions of the large intestine].

To clarify the pathogenesis and endoscopic features of ischemic lesions of the colon, experimental ischemia was induced in dogs by arterial ligation, gelfoam injection, and clipping. In addition, clinical and endoscopic features of ischemic lesions in ischemic colitis cases in human were studied. In the experimental model, arterial ligation including marginal arteries frequently induced erosions in the large intestine, whereas ligation of the colic artery alone did not induce apparent mucosal lesions of the large intestine. Gelfoam injection to produce thrombi into caudal mesenteric artery or middle colic artery induced ulcers with a high rate of incidence and frequently accompanied by intestinal perforation. Temporal impairment of blood supply by arterial clipping produced erosion, but not ulcers. A high incidence of erosion was obtained in a group that underwent clipping for a prolonged period and a group of receiving Alosenn. Mucosal blood flow measured by the hydrogen gas clearance method was significantly decreased at 1 hr and 4 hr after gelfoam injection compared with those after arterial ligation. In human cases of ischemia following arterial surgery, endoscopic features were similar to those lesions of the experimental ischemia induced by gelfoam injection. These results suggest that thrombi in peripheral small arteries may play a major role in the pathogenesis of ischemic lesions of the large intestine.

Adult↗
PubMed1994

The glycocalyx, biofilm, microbes, and resistant infection.

Biomaterial implants, traumatized tissues and bone are susceptible to immediate and delayed infections because microbes preferentially adhere to "inert biomaterials" or to damaged tissue surfaces. This type of infection is resistant to antibiotic therapy and most often requires removal of the prosthesis or infected tissue. This article discusses glycocalyx, biofilm, microbes, and resistant infection in prosthesis or infected tissue.

Bacterial Adhesion↗
PubMed1994

Beta-adrenergic regulation of gap-junctional intercellular communication in cultured rabbit gastric epithelial cells.

The effect of a beta-adrenergic agonist, isoproterenol, on gap-junctional intercellular communication (GJIC) and intracellular cyclic AMP (cAMP) content was investigated in cultured rabbit gastric epithelial cells. Isoproterenol rapidly enhanced GJIC determined by the Lucifer yellow transfer at 10(-6) and 10(-5) M but the effect at 10(-6) M was variable. The enhancement of GJIC by 10(-5) M isoproterenol, which disappeared within 10 or 30 min, was inhibited by a beta blocker, propranolol. Isoproterenol (10(-6) M) greatly increased cAMP at 5 min and much more so at 20 min after its addition. Colforsin (also known as forskolin) and 3-isobutyl-1-methylxanthine (IBMX) enhanced GJIC until 16 and 20 min after their addition, respectively. Both colforsin and IBMX increased the cAMP content by a lesser extent than 10(-6) M isoproterenol. Isoproterenol (10(-5) M) inhibited the GJIC enhanced by colforsin or IBMX. Propranolol abolished the inhibition of GJIC by isoproterenol in the presence of IBMX. Both amiloride, an inhibitor of the Na+/H+ exchanger, and nigericin, a K+/H+ antiporter, inhibited the GJIC enhanced by isoproterenol, IBMX, colforsin and irsogladine. An inhibitor of cAMP-dependent protein kinase A, H-89 (N-[2-((3-(4- bromophenyl)-2-propenyl)-amino)-ethyl]-5-isoquinolinesulfonamide), abolished the enhancement of GJIC by colforsin and IBMX but did not abolish that by isoproterenol.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗
PubMed1994

Thyroid diseases in cohort studies of A-bomb survivors.

A fixed population of about 120,000 subjects was selected from those A-bomb survivors and unexposed controls for the purpose of follow-up studies on their late health effects. One hundred twelve cases of thyroid cancer were found in the study period between 1958 to 1979. The relative risk increased with thyroid dose: the excess relative risk per Gray was 1.1. The prevalence of thyroid diseases was evaluated in 2,587 subjects in Nagasaki: one or more diagnoses for thyroid diseases were made in 447.

Cohort Studies↗
PubMed1994

The effect of epidural morphine on human intestinal motility in the early postoperative period.

The early postoperative recovery of intestinal motility and the response of motility to epidural morphine were investigated in 20 patients. Periodic motor activities in the jejunum were recovered within 32 hours in all cases. The length of these cycles increased gradually from the 1st (23.2 min) to the 4th (41.7 min) postoperative day. Morphine and lignocaine were given through an epidural catheter. Morphine induced premature migrating motor complexes (MMC) in all cases, whereas lidocaine failed to evoke this response in every case. The mean duration (19.8 min) and maximal amplitude (62.8 mmHg) of the burst activities induced by morphine were significantly longer and higher than those occurring spontaneously (7.7 min and 35.6 mmHg, respectively). The intervals between the induced and the subsequent spontaneous contractions were the same as the intervals between spontaneous contractions. These observations indicate that epidural morphine induced premature MMC without interrupting recovery patterns from postoperative gastrointestinal paralysis.

Adult↗
PubMed1994

[Clinical analysis of methicillin-resistant Staphylococcus aureus (MRSA) infection].

In 14 patients from which methicillin-resistant Staphylococcus aureus (MRSA) was isolated at the Department of Urology, Tone Chuo Hospital June, 1992 and October, 1993, the site of infection, background of patients, and drug resistance were analyzed. The 14 patients consisted of 11 males and 3 females between 45 and 85 years old with a mean of 71.6 years. The site from which MRSA was isolated was urine in 11, wound in 2, nasal cavity in 1, pharynx in 1, and renal fistula in 1 (detected at 2 or more sites in 2). The underlying condition was prostate hyperplasia in 2, prostate cancer in 4 (after radical prostatectomy in 1, complicated by bladder stone in 1), bladder tumor in 3, (during bladder instillation of BCG in 1), perirenal abscess in 2, renal pelvic tumor in 1, neurogenic bladder in 1, and after Boari's operation in 1. Urethral catheterization had been performed in 3. A fewer of 38 degrees C or above was noted in 3. Mixed infection was observed in 10, and was caused by Escherichia coli in 2, Proteus mirabiris in 1, Candida in 1, Klebsiella in 2, Pseudomonas aeruginosa in 2, and Serratia in 2. Four patients has previously been administered antibiotics, which were third generation cephems in 3 and penicillin in 1. The drug sensitivity was 100% for vancomycin (VCM), 30% for imipenam (IMP), 31% for minomycin (MINO), 31% for amikacin (AMK), and 7% for fosfomycin (FOM). As for chemotherapy, VCM+FOM+sulbactam/cefoperazone were administered to 6, and ceftazidime+ MINO were administered to 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Retrograde ileal bile acid tolerance test--experimental and clinical study].

Oral bile acid tolerance test has been used to detect a functional impairment of the small intestine in Crohn's disease. The damage should be strongly expressed in the terminal ileum because of preferential involvement, therefore, we devised the retrograde ileal bile acid tolerance test, where bile acid was administered into closed segment of the terminal ileum using a 4 lumen double balloon tube through a colonoscope. In basic experiment using dogs with or without experimentally induced ileitis by trinitrobenzene sulfonic acid, ursodeoxycholic acid (UDCA) solution of several concentrations was given into the duodenum (corresponding to oral test) or the terminal ileum. Plasma was collected for 60 min at given time points, and then plasma total bile acid level (TBA) and bile acid fraction were measured. In a clinical study, both oral test and retrograde ileal bile acid tolerance test were carried out in 5 cases of Crohn's disease with ileitis and 6 healthy control subjects. Plasma was collected for 30 min after ileal loading of 30 ml UDCA solution (10 mg/ml). In oral bile acid tolerance test, plasma was collected for 180 min after taking 600 mg of UDCA. Basic experiments in dogs showed: 1) TBA was increased in proportion to dose of UDCA loaded in the intact ileum. 2) Absorption of bile acid after ileal loading of UDCA was significantly suppressed in experimentally induced ileitis, whereas no difference was observed after duodenal loading of UDCA. Clinical study in human subjects showed; 1) Absorption of bile acid after ileal loading of UDCA was significantly suppressed in Crohn's disease, compared with controls. 2) Examination of bile acid fraction showed that more than 90% of bile acid increased in serum after ileal loading of UDCA was free type UDCA. These findings indicated that retrograde ileal bile acid tolerance test is useful for an accurate evaluation on absorptive function in the ileum.

Adult↗
PubMed1994

[Aortic dissection with giant pseudoaneurysm as a rare late complication of aortic valve replacement--a case report].

A 60-year-old man who had received aortic valve replacement for aortic regurgitation at 47 years of age developed sudden syncope and shock on Mar. 28, 1991. Close examination including CT scan and aortography revealed DeBakey type I aortic dissection with giant pseudoaneurysm which compressed superior vena cava and right pulmonary artery and caused superior vena cava syndrome. He underwent elective ascending aortic replacement under profound hypothermic cardiopulmonary bypass and circulatory arrest on Jun. 17, 1991. The giant pseudoaneurysm was present posterolaterally to the ascending aorta. It communicated with the false lumen and contained massive thrombi. The intimal tear of the ascending aorta existed along the suture line of previous aortotomy.

Aortic Dissection↗
PubMed1994

[Detection of Aspergillus fumigatus DNA by polymerase chain reaction in the clinical samples from individuals with pulmonary aspergillosis].

Aspergillosis is a disastrous cause of mortality and morbidity in patients in an immunocompromised state and old lung tuberculosis. However, the diagnosis of aspergillosis remains unsettled. In the present study, we developed a test to detect the Aspergillus fumigatus DNA using polymerase chain reaction (PCR) in clinical samples including sputum and bronchial aspirations from the patients with aspergillosis. We selected 2 pairs of oligonucleotide primers and the DNA for the small subunit ribosomal RNA of aspergillus fumigatus and they were significantly amplified. Although isolation of Aspergillus DNA may reflect contamination and colonization without infection, no aspergillus DNA was found in sputum or bronchial aspirations from the patients with lung cancer or interstitial lung diseases except a case of pulmonary fibrosis associated with rheumatoid arthritis chronically received 20 mg of corticosteroid. There was a 100% correlation between the culture results and the nested PCR results in the patients with pulmonary aspergillosis. These findings indicate that PCR detection of aspergillus fumigatus might be valuable for the diagnosis of aspergillosis.

Aged↗
PubMed1994

[Protective effects of prostaglandin E1 on postoperative liver function after cardiac surgery].

Effects of prostaglandin E1 (PGE1) on liver function were studied in 72 patients who underwent mitral valve replacement (MVR) and coronary artery bypass grafting (CABG). The patients were divided into three groups: (A) patients with preoperative hepatic dysfunction who underwent MVR; (B) patients without previous hepatic dysfunction who underwent MVR; (C) patients without hepatic dysfunction who underwent CABG. About half of the patients in each group received PGE1 during the operation and postoperative period in the ICU. Change of serum GOT, GPT, albumin, total bilirubin, and cholinesterase (ChE) showed no difference between the patients with and without PGE1 administration in groups B and C. But, in group A, PGE1 administration significantly ameliorated the decrease of ChE, a condition which is usually observed in the first and second postoperative weeks after MVR. None of the patients showed severe hepatic dysfunction in the PGE1 group. One patient in the control group A revealed severe hepatic failure with high bilirubinemia and decreased ChE. These results suggest that the administration of PGE1 to patients with hepatic dysfunction, scheduled for MVR, might protect the liver from deterioration.

Aged↗
PubMed1994

[Total aortic replacement in a patient with extensive thoracoabdominal aortic aneurysm--a case report].

A 35-year-old woman with a form fruste of Marfan's syndrome, presented the extensive thoracoabdominal aortic aneurysm. CT scan, MRI and aortogram revealed that she had a true aneurysm of ascending aorta and aortic arch and chronic DeBakey IIIb dissecting aneurysm extending throughout the descending thoracic and abdominal aorta. The surgical treatment was consisting of two staged operations. At the first operation, ascending aorta and aortic arch were reconstructed under cardiopulmonary bypass and selective cerebral perfusion. Elephant trunk method was employed for the second operation. The second operation was performed by graft replacement of the entire descending thoracic and abdominal aorta with reattachment of intercostal and visceral arteries. She discharged the hospital without any complication including paraplegia.

Adult↗
PubMed1994

[An infradian rhythm of weight increment velocity in patients with Crohn's disease during nutritional therapy].

We examined the rhythm of weight velocity in eight patients with Crohn's disease. In this paper we used the spline smoothing technique to study the cycle in the weight increment velocity curves derived from individual data during nutritional therapy. As a result of the weight measurement at four-day intervals, an infradian rhythm with the average cycle of 9.6 +/- 0.7 was recognized in all of the subjects in terms of the weight increment velocity. This rhythm was especially conspicuous in three adolescent patients with serious nutritional lesion. The cycle of the rhythm was unaffected by any of the following factors: energy intake, contents of nutritional therapy, medical examination during the period. Our findings of a common cycle in the process of convalescence from a low nutritious stage in patients with Crohn's disease suggest that, in others as well, the weight increment velocity might have an infradian rhythm with a kind of inherent periodicity.

Adolescent↗