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Biomedical subjects

T Mitsui

Publications and source records attributed to T Mitsui.

At least 19 recordsLinked to original sources
PubMed1995

Intracellular signal transduction of PBAN action in lepidopteran insects: inhibition of sex pheromone production by compactin, an HMG CoA reductase inhibitor.

Pheromone biosynthesis activating neuropeptide (PBAN) regulates sex pheromone production in the pheromone glands of many species of female moths. In order to probe the biochemical steps as well as underlying mechanisms regulated by PBAN, we have tested the effect of chemicals on sex pheromone production by using an in vitro assay. Among the chemicals we tested here, compactin, a specific 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor, clearly inhibited the pheromone biosynthesis in the silkworm, Bombyx mori, and the common cutworm, Spodoptera litura. Since the activation of HMG CoA reductase occurs by dephosphorylation mediated by a specific phosphatase and the biochemical step regulated by PBAN in bombykol biosynthesis is similar to the one catalyzed by HMG-CoA reductase in cholesterol biosynthesis, the present results support the idea that phosphoprotein phosphatase has a significant role to regulate bombykol production in the intracellular transduction of PBAN action in B. mori.

Amino Acid Sequence↗
PubMed1995

Influence of bypass grafting to the infarct artery on late potentials in coronary operations.

BACKGROUND: Late potentials (LPs) after myocardial infarction identify the risk of arrhythmic events and sudden death, and the absence of anterograde flow in the infarct-causing occluded coronary artery frequently is associated with LPs on signal-averaged electrocardiography. The present study was designed to clarify the influence of revascularization of the infarct artery on the LPs in the late course after myocardial infarction. METHODS: We studied 21 patients after myocardial infarction with positive LPs who had at least one occluded infarct coronary artery. We investigated the LPs on signal-averaged electrocardiograms on the day of elective coronary artery bypass grafting (CABG) and 1 week after CABG. RESULTS: There were 25 infarct arteries in the study patients, 13 of which were grafted. The positive LPs disappeared soon after CABG in 13 patients, 10 of whom had grafts to all of the infarct arteries. The LPs persisted in 8, who received no graft to the infarct artery. One week after CABG, the LPs were still present in 4, all of whom had no graft to the infarct right coronary artery. CONCLUSIONS: In patients with positive LPs late after myocardial infarction, grafting to the infarct artery eliminated the LPs soon after CABG.

Aged↗
PubMed1995

Relief of airway compression by enlarged pulmonary artery--modified palliative suspension of the artery after plication.

A new modification of the technique for plication and suspension of the pulmonary artery in critically ill infants and children is described. The technique consists of (1) left lobe thymectomy, (2) insertion of a polytetrafluoroethylene sheet to provide complete coverage of pericardium, (3) plication of dilated pulmonary artery and (4) suspension of plicated pulmonary artery to the left side of the anterior chest wall. We employed this technique in 7 patients with respiratory distress due to tracheal and/or broncheal compression with massive left-to-right shunt (5 patients) and with absent pulmonary valve (2 patients). Five of these patients (71%) could be weaned from the respirator in the postoperative phase with this surgery. Although this procedure is palliative, this simple technique might be one of the choices for critically ill infants and children.

Airway Obstruction↗
PubMed1995

[Citrate and ionized calcium on extracorporeal circulation in pediatric cardiac surgery].

The control of optimum concentrations of ionized calcium Ca2+ during cardiopulmonary bypass is important in maintaining cardiac function and reducing reperfusion injury. Ca2+ may be in part dependent upon the serum level of citrate Cit in use of hemodiluted prime in pediatric cardiac surgery. The purpose of this study was to ascertain fluctuations of Ca2+ during bypass in relation to Cit and to study control of optimum Ca2+. Ca2+ and Cit was measured prior to and every 10 or 20 minutes during bypass in 12 children aged 21 days to 6 years. Of 6 patients (body weight less than 6 kg) received acid-citrate-dextrose (ACD) solution 20 ml before aortic declamp to give low Ca2+ for reducing reperfusion injury. Ca2+ showed initial drop and then gradually increased as the result of decreasing Cit. Ca2+ was inversely correlated with Cit (r = 0.85, p = 0.0001). When ACD 20 ml was added, Ca2+ significantly decreased from 1.00 +/- 0.13 to 0.65 +/- 0.13 mmol/l. However, Cit remained 24.3 +/- 13.3 mg/dl at the end of bypass. In conclusion, the results of this study suggest that gradually increasing Ca2+ during bypass may be related to the rate of citrate metabolism and the use of citrate for the control of Ca2+ remains questionable.

Calcium↗
PubMed1995

[Postoperative bronchial stenosis associated with IAA complex and transendoscopic resection of intrabronchial granulation].

Problem with stenosis of the left bronchus was encountered in a patient with type B interrupted aortic arch complex after the arch reconstruction and pulmonary artery banding. Bronchoscopic study disclosed the intraluminal granulation of left bronchus and transendoscopic resection of the granulation successfully relieved the stenosis and brought the patient to full recovery.

Airway Obstruction↗
PubMed1994

Increased expression of CD48 on neutrophils activated in childhood patients with aplastic anemia.

Activation-associated antigens such as CD11b, CD14 and CD64 of neutrophils have been reported. Although CD48 is an activation antigen of lymphocytes and monocytes, whether it is an activation antigen of neutrophils has not previously been examined. Herein, using FACS analysis, we examined the expression of surface CD48 on neutrophils activated in vivo by G-CSF administered for the treatment of idiopathic aplastic anemia. CD48 expression was increased 24 h after the initial G-CSF infusion and peaked within 1 week. Within a few days after discontinuation of G-CSF administration, it returned to the pretreatment level. This indicates that CD48 is an activation antigen of neutrophils.

Adolescent↗
PubMed1992

Purification and characterization of smooth muscle myosin-associated phosphatase from chicken gizzards.

Myosin light chain phosphatase associated with smooth muscle myosin (MAPP) was isolated from chicken gizzard. The MAPP was tightly associated with myosin and was not dissociated from myosin under the physiological ionic conditions. The phosphatase was dissociated from myosin in the presence of high MgCl2, i.e. 80 mM MgCl2. The binding site of the enzyme on the myosin molecule was the subfragment-2 region, since the enzyme did bind to the myosin rod and heavy meromyosin but not to the subfragment-1 affinity column. MAPP was purified with a heparin-Sepharose 6B column, and two activity peaks were obtained, i.e. MAPP I and MAPP II. The major activity peak, MAPP I, was further purified to homogeneity by thiophosphorylated myosin light chain-Sepharose 4B column chromatography. MAPP I was a tetramer composed of four 34-kDa subunits. The enzyme preferentially dephosphorylated the beta-subunit of phosphorylase kinase and was strongly inhibited by the heat- and acid-stable protein phosphatase inhibitor-1, whereas it was partially inhibited by the inhibitor-2. The IC50 (concentration of inhibitor giving 50% inhibition) value for the inhibition of the enzyme by okadaic acid was 70 nM which was about eight times higher than skeletal muscle type-1 and 390 times higher than type-2 protein phosphatase. These results demonstrate that the MAPP I is a type-1-like protein phosphatase, although the properties are not the same as type-I phosphatase. The properties of the myosin-associated phosphatase were distinct from the phosphatases reported previously, although some properties were similar to smooth muscle phosphatase-IV. Therefore, it is concluded that MAPP I is a novel smooth muscle protein phosphatase. Since it strongly associated with smooth muscle myosin, it is likely that MAPP I is responsible for the dephosphorylation of smooth muscle myosin in situ.

Adenosine Triphosphate↗
PubMed1992

Isolation and primary structure of a novel pheromonotropic neuropeptide structurally related to leucopyrokinin from the armyworm larvae, Pseudaletia separata.

A novel pheromonotropic neuropeptide has been isolated from a head extract of the armyworm larvae, Pseudaletia separata, by a seven step purification procedure using an in vivo assay with decapitated female moths of Bombyx mori. Amino acid sequence analysis and comparison with synthetic peptides established the primary structure of the peptide, termed Pseudaletia pheromonotropin (Pss PT), as H-Lys-Leu-Ser-Tyr-Asp-Asp-Lys-Val-Phe-Glu-Asn-Val-Glu-Phe-Thr-Pro-Arg-Le u-NH2. Pss PT is structurally related to leucopyrokinin, an insect myotropic neuropeptide, and possesses the C-terminal pentapeptide, Phe-Thr-Pro-Arg-Leu-NH2, responsible for the biological activity.

Amino Acid Sequence↗
PubMed1992

Antibodies against synthetic oligopeptides deduced from the putative core gene for the diagnosis of hepatitis virus infection.

Immunoassays were developed to detect antibodies against oligopeptides deduced from the putative core gene of hepatitis C virus, and their performances were compared with that of the commercial immunoassay for antibodies against the product of nonstructural regions of hepatitis C virus (anti-C100-3). A 19-mer oligopeptide (CP10) and a 36-mer oligopeptide (CP9) were chemically synthesized, which represented hydrophilic regions of the product of the hepatitis C virus core gene. They were used to capture corresponding antibodies, anti-CP10 and anti-CP9, by enzyme-linked immunosorbent assay in sera from patients with acute or chronic non-A, non-B liver disease and in blood donations. At the onset of acute non-A, non-B hepatitis, anti-CP10 was detected in 15 of 20 patients (75%), and anti-CP9 was detected in 14 patients (70%). This was more frequent than anti-C100-3, which was found in only 9 patients (45%). In 186 patients with chronic non-A, non-B liver disease, anti-CP9, anti-CP10 or both were detected in 170 patients (91%). This was more frequent than anti-C100-3, which was found in 138 patients (74%). Blood with anti-CP10 as the single serological marker for hepatitis C virus infection transmitted non-A, non-B hepatitis by needlestick exposure. In sera from 558 apparently healthy blood donors, anti-CP10 was detected in 55 donors (9.9%), anti-CP9 was detected in 26 donors (4.7%) and anti-C100-3 was detected in 7 donors (1.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

[A case of malignant rheumatoid arthritis with corticosteroid-reactive subacute myelopathy and multiple peripheral neuropathy].

We reported a 64-year-old man who had malignant rheumatoid arthritis (MRA) and developed subacute myelopathy and peripheral neuropathy. He had suffered from seropositive rheumatoid arthritis for 4 years, and developed weakness of four limbs, dysuria and constipation two months before the admission. Neurological examination revealed the diffuse muscle wasting and weakness in four limbs. Deep tendon reflexes were hyperactive in four limbs, but not in jaw jerk. Babinski sign was positive bilaterally. Deep sensation was decreased in four limbs and superficial sensation was decreased below the neck. Dysuria and constipation were noted, but anal and bulbocavernosus reflexes were present. On laboratory examination, RF and RAHA increased markedly. Serum complements decreased and immune complexes were positive. Nerve conduction study demonstrated multiple entrapment neuropathy in addition to mononeuritis multiplex. Histological examination of the biopsied sural nerve disclosed the obliterating endarteritis in the epineurium, and marked decrease in number of myelinated fibers. No compressive lesions were seen in the spinal canal by spine X-ray and MRI. Assuming that inflammatory process induced cervical myelopathy, corticosteroid therapy (predonisolone 60 mg/day) was administered and alleviated neurological symptoms, in accordance with the improvement of serological abnormalities. Therefore, an inflammatory process associated with MRA was supposed to damage the spinal cord as well as peripheral nerves in the present case.

Acute Disease↗
PubMed1992

Hepatitis C virus infection in medical personnel after needlestick accident.

Hepatitis C virus infections in medical personnel after needlestick accidents have been documented generally by detection of seroconversion to a hepatitis C virus nonstructural region antigen, c100-3 (a marker of infection). We tested for hepatitis C virus core-derived antibodies and genomic RNA in addition to c100-3 antibody in 159 cases of needlestick exposure that did not involve patients positive for HBsAg. Of these we found 68 cases with index patients positive for both hepatitis C virus RNA and antibodies and members negative for antibodies to HCV core or c100-3 before the needlestick accidents. Seven of these medical personnel became infected with hepatitis C virus after the accidents. Their hepatitis was generally subclinical or self-limited and transient, except for one patient in whom liver enzyme elevation persisted along with the antibodies. In our study, the risk of hepatitis C virus transmission from a single needlestick accident with hepatitis C virus RNA-positive blood was 10%, considerably higher than the 4% estimated in a previous study. We found that donor blood with antibody to an hepatitis C virus core-derived peptide with enzyme-linked immunosorbent assay optical densities greater than 2.0 carried a significant risk of transmitting hepatitis C virus to needlestick victims. No hepatitis C virus seroconversions occurred in medical personnel exposed to hepatitis C virus antibody-negative or hepatitis C virus RNA-negative blood; however, one such exposure resulted in a very mild non-A, non-B, non-C hepatitis.

Health Personnel↗
PubMed1992

[The usefulness of the emergency hepatobiliary scintigraphy to rule out acute cholecystitis--43 patients report].

We studied emergency hepatobiliary scintigraphy in the 43 patients to rule out acute cholecystitis. After injection of 185-222 MBq (5-6 mCi) of 99mTc-EHIDA or 99mTc-HIDA, serial static scintigraphic images were obtained up to 7 hours in maximum. Of 43 patients in this study, 20 had a normal scan and finally in all of them cholecystitis was ruled out. Of the 43 patients, 14 had an abnormal scan (nonvisualized gall bladder). In 10 of them the diagnosis of acute cholecystitis was confirmed after emergency cholecystectomy. The other 9 patients of 43 had an incomplete scan mainly due to liver dysfunction. Four of them had acute cholecystitis in the cholecystectomy. These results indicate that acute cholecystitis can be excluded by the findings of gall bladder visualization in hepatobiliary scintigram. We concluded that emergency hepatobiliary scintigraphy is very useful to rule out acute cholecystitis.

Acute Disease↗
PubMed1992

[A case report of poststernotomy mediastinitis treated with the pectoralis major muscle flap after protracted wound irrigation].

A 8-year-old boy developed mediastinitis after direct closure of atrial septal defect. Methicillin-resistant Staphylococcus aureus (MRSA) was detected from the wound. Intermittent wound irrigation with povidone-iodine solution and vancomycin solution was protracted for two months. After the remission of MRSA infection, implantation of pectoralis major muscle flap was performed. Without recurrence of infection the wound was healed completely. Although pectoralis major muscle flap is an effective method of choice for mediastinitis, an appropriate timing of enforcing this method should be investigated hereafter.

Child↗