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Biomedical subjects

M Shimada

Publications and source records attributed to M Shimada.

At least 703 records · Page 39Linked to original sources
PubMed1989

Hepatic level of mRNA in relation to polymorphism and strain difference in expression of cytochrome P-450g.

Hepatic level of mRNA for P-450g was determined in male and female rats of Sprague-Dawley, ACI and Fischer strains using a specific oligonucleotide probe. The mRNA level in female Sprague-Dawley and Fischer rats was undetectable in accordance with a very low or undetectable level of P-450g protein. The mRNA was detected in all male ACI rats, in which high levels of P-450g protein were detected. In Fischer male rats, mRNA for P-450g was clearly detected in the liver, but P-450g protein was not detected. Moreover, the mRNA was detected in the liver of all male Sprague-Dawley rats, irrespective of the expressed level or absence of P-450g protein. As a most plausible explanation of the observed discordance in the levels of P-450g mRNA and protein, translation of unstable protein for microheterogeneous P-450g is discussed.

Animals↗
PubMed1989

[Multiple myeloma presenting as a mass lesion in the frontal bone. Case report].

The patient, a 51-year-old male, was hospitalized for evaluation of a frontal subcutaneous mass. There were no signs of intracranial hypertension and no neurological deficit. His general medical status was normal, but he had been diagnosed as having immunoglobulin G (IgG) lambda type multiple myeloma by bone marrow aspiration and immunoelectrophoresis. A plain skull X-ray showed a large bony defect and multiple punched-out lesions in the frontal bone. Computed tomography showed an epidural high-density mass with marked homogeneous enhancement. Carotid angiography showed a hypervascular tumor fed by the bilateral external carotid arteries. At surgery, a reddish tumor was detached from the dura mater and totally resected. The pathological diagnosis was IgG lambda type plasmacytoma. After 40-Gy radiation and chemotherapy, the postoperative course over the following year was uneventful. Although the prognosis of multiple myeloma is poor, that of solitary intracranial plasmacytoma is reportedly good. However, since there is a high incidence of transition from solitary plasmacytoma to multiple myeloma, patients with intracranial plasmacytoma should be followed for a long period.

Combined Modality Therapy↗
PubMed1989

cDNA cloning of human calpastatin: sequence homology among human, pig, and rabbit calpastatins.

cDNA of human calpastatin, an inhibitor protein specific for calpain (EC 3.4.22.17; Ca2(+)-dependent cysteine proteinase) was isolated by screening of a library prepared from human liver mRNA with pig calpastatin cDNA fragment as a probe. The primary structure of human calpastatin was deduced from the nucleotide sequence of the cDNA and compared with that of pig and rabbit calpastatins already reported. Human calpastatin consisted of 673 amino acid residues and had 78% and 77% identity to pig or rabbit calpastatins, respectively. Human calpastatin had a domain structure with four internally repetitive sequences and one N-terminal non-homologous sequence like the other calpastatins. Human calpastatin had two deletions, 22 and 13 residues long in domain L and domain 1, respectively, compared to pig or rabbit calpastatins.

Amino Acid Sequence↗
PubMed1989

Suppression of hepatic levels of an ethanol-inducible P-450DM/j by growth hormone: relationship between the increased level of P-450DM/j and depletion of growth hormone in diabetes.

The mechanism of the suppression of an ethanol-inducible cytochrome P-450 (P-450DM/j) by pituitary hormone has been studied in rats. The hepatic content of P-450DM/j protein quantitated by Western blots was low but was 2-fold higher in male than female untreated rats (75 and 34 pmol/mg of protein, respectively). The content was increased 2.6-fold (male) and 5.6-fold (female) by hypophysectomy and the sex-related difference was abolished. Treatment of hypophysectomized rats with human growth hormone (hGH), but not with prolactin, reversed the increased amounts of P-450DM/j protein. The hGH-induced suppression was more effective with the continuous infusion than intermittent injection. The hepatic level of P-450DM/j mRNA, determined by the use of a 23-mer oligonucleotide probe, was also changed by hypophysectomy and/or hGH-treatment, largely in parallel with the changes in the content of P-450DM/j protein and microsomal p-nitrophenol and aniline hydroxylations. These results suggest that growth hormone exerts the suppressive effect on P-450DM/j through a somatogenic receptor-mediated process. In another growth hormone-depleted condition, diabetes, the hepatic level of P-450DM/j mRNA was also increased to a level similar to that in hypophysectomized rats, but the protein content was 2- to 3-fold higher in diabetic than hypophysectomized rats. These results indicate, in addition to the reduction of serum growth hormone level, the presence of another stimulatory factor, which acts translationally or posttranslationally in livers of diabetic rats. On the other hand, coordinate changes in the level of P-450DM/j protein and the mRNA in hypophysectomized rats indicate that growth hormone acts rather directly and suppresses the level of P-450DM/j mainly at a pretranslational step in rat livers.

Animals↗
PubMed1989

Diethylcarbamazine: inhibitory effect on acetylcholinesterase of Dirofilaria immitis and Brugia pahangi.

Anti-acetylcholinesterase activity of diethylcarbamazine (DEC) was studied. Acethylcholinesterase (AchE) of adult worms of Dirofilaria immitis, those of the 4th-stage larvae, early 5th-stage larvae and adults worms of Brugia pahangi, and that of hamster brain tissue were all inhibited by DEC. Michaelis constant (Km) of D. immitis and B. pahangi adult worm AchE were 1.47 x 10(-4) and 1.81 x 10(-4) M respectively. DEC was a competitive inhibitor of the filarial AchE. Inhibition constant (Ki) for AchE of D. immitis and B. pahangi adult worms were 2.56 x 10(-4) and 6.39 x 10(-4) M, respectively. DEC is a less potent anticholinesterase inhibitor, because Ki of DEC is 10(4) times higher than that of eserine, a potent anti-cholinesterase agent.

Acetylcholinesterase↗
PubMed1989

[Electrophysiologic effects of intravenous digoxin in infants and children with Wolff-Parkinson-White syndrome].

Electrophysiologic properties of the accessory pathway were investigated before and after the intravenous administration of digoxin (0.01-0.02 mg/kg) during electrophysiologic studies in 14 infants and children with the Wolff-Parkinson-White syndrome. Determination of electrophysiologic properties of the accessory pathway was made using transesophageal atrial pacing and/or intracardiac right atrial pacing. Maximal effect on the accessory pathway after intravenous digoxin was observed during one to six hours. Effective refractory period of the accessory pathway increased in 6 of the 14 patients, decreased in 4 and unchanged in 4. Shortest AP 1:1 conduction increased in 5 of the 12 patients, decreased in 3 and unchanged in 4. Tachycardia was not induced after digoxin in only one patient. Tachycardia cycle length, ventriculoatrial conduction time and atrioventricular conduction time were unchanged after digoxin in almost all cases. Thus, digoxin is not the first choice drug for termination and prevention of the preexcitation syndrome.

Adolescent↗
PubMed1989

[A case report of successful one-stage operation in TGA (group III) with WPW syndrome].

A patient who had received balloon atrioseptotomy and B-T shunt operation previously experienced recurrent episodes of supraventricular tachycardia, and was refractory to medical treatment since the age to 3. At 9 years, the patient underwent intraoperative electrophysiological mapping which confirmed the earliest breakthrough at the crux of posterior septal region. Rastelli's operation and division of posterior septal Kent was simultaneously performed successfully. Post operative ECG was normalized with abolition of delta wave, and PSVT was gone. We concluded that the division of Kent bundle should be simultaneously performed with operative reconstruction in patients with congenital heart disease and WPW syndrome on postoperative care for SVT.

Bundle of His↗
PubMed1989

Craniopharyngioma with extension into the cerebellopontine angle. Case report.

A rare case of craniopharyngioma which extended from the suprasellar region into the cerebellopontine angle (CP angle) is reported. This patient, a 18-year-old man who underwent two surgeries for suprasellar craniopharyngioma did not show recurrence during interval studies. However, nine years after the second surgery CT scan and MRI indicated a left CP angle mass when he was submitted to suboccipital craniectomy and tumor resection. He had been on human growth hormone (hGH) regimen for his pituitary dwarfism before tumor recurrence. The authors speculate retrospectively that the tumor growth in the left CP-angle was correlated with hGH therapy in this particular case.

Adolescent↗
PubMed1989

[Electrophysiologic effects of isoproterenol in children with Wolff-Parkinson-White syndrome].

12 children with the Wolff-Parkinson-White (WPW) syndrome underwent electrophysiologic study before and after the intravenous administration of isoproterenol. Effective refractory period of the accessory pathway and shortest paced cycle length with 1:1 atrioventricular (A-V) conduction via the accessory pathway were shortened after intravenous isoproterenol in all patients. Orthodromic reciprocating tachycardia was induced after isoproterenol in one patient who did not documented tachycardia attack or palpitation before. Anterograde A-V conduction via A-V node and retrograde V-A conduction via accessory pathway were enhanced. Thus, tachycardia cycle length was shortened. Potential high risk group patient who develop hazardous atrial fibrillation during exercise in the WPW syndrome may be selected by isoproterenol infusion.

Adolescent↗
PubMed1989

[Anesthetic management of a patient with acromegaly complicated with hyperthyroidism].

A rare anesthetic experience of a 30-year-old woman with acromegaly complicated with Basedow's disease is reported. After the thyroid function was successfully controlled by drug therapy, resection of pituitary adenoma was performed under general anesthesia. Anesthesia was induced and maintained with NLA. No problem was observed during the operation and postoperative period. Careful attention should be paid to the management of circulation, respiration, metabolism and endocrinium through the perioperative period.

Acromegaly↗
PubMed1989

Significance of lecithin:cholesterol acyltransferase activity as a prognostic indicator of early allograft function in clinical liver transplantation.

Rapid and accurate assessment of allograft function in the early postoperative period is critical for successful liver transplantation. This study evaluated the efficacy of lecithin:cholesterol acyltransferase (LCAT) activity as an indicator of early allograft function in human orthotopic liver transplantation (OLTx). During a three-month period between September and November 1987, 9 of 11 adult OLTx recipients whose graft exhibited poor function were studied. Poor graft function was defined as primary nonfunction, need for retransplantation within a week after OLTx, or elevation of the prothrombin time over 20 sec early after OLTx. Plasma LCAT activities (measured pretransplant and at 0, 6, 12, 18, and 24 hr, as well as 3 days, after OLTx) and pretransplant clinical variables were compared with those of 15 control patients whose graft exhibited good function. A significant correlation was found between mean LCAT activities during the first 24-hr after OLTx and early allograft function (P less than 0.05, chi 2 = 5.23). When pretransplant histological findings of the 6 grafts with poor function and the 15 controls together were correlated with the mean LCAT activity within 24 hr following OLTx, a significant association was demonstrated (P less than 0.05). This study suggests that plasma LCAT activity is an effective and practical method for assessing early allograft function following OLTx.

Humans↗
PubMed1989

[Electrophysiologic effects of calcium channel blockers on supraventricular tachycardia in children].

Calcium channel blockers (diltiazem or verapamil) were administered in 17 pediatric patients with supraventricular tachycardia to evaluate their drug effects on electrophysiologic properties and the tachycardia zone. Using electrophysiologic technique, 10 patients were diagnosed as having orthodromic reciprocating tachycardia (ORT), including three patients with concealed atrioventricular bypass tracts. Four patients were diagnosed as having atrioventricular nodal re-entrant tachycardia (AVNRT) of the slow-fast type and three patients were diagnosed as having intra-atrial re-entrant tachycardia (IART). Diltiazem was given to 10 patients; verapamil, to eight patients at doses of 0.15-0.2 mg/kg intravenously. Electrophysiologic properties and the tachycardia zone were then evaluated before and after the administration of calcium channel blockers. Diltiazem and verapamil produced no significant changes in the sinus node and atrial functions including basic sinus cycle length, sinoatrial conduction time, maximum sinus node recovery time and the effective atrial refractory period. Although sinus cycle length was shortened after verapamil in half the cases, it was due to increased sympathetic tone secondary to hypotension rather than to direct action of verapamil. Calcium channel blockers, however, prolonged the PR interval and significantly increased the effective refractory period of the atrioventricular node. Properties of the atrioventricular bypass tracts were not affected by calcium channel blockers. Diltiazem and verapamil were markedly effective in ORT and AVNRT. Their re-entrant circuits, including the atrioventricular node and the tachycardia zones, were shortened or resolved. However, IART showed no significant change in the tachycardia zone after the administration of calcium channel blockers, because the re-entrant circuit was not present within the atrioventricular node.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Anesthetic management of a patient with Conradi's syndrome (chondrodysplasia punctata)--a case report].

Conradi's syndrome is a rare hereditary disease characterized by punctate epiphyseal calcifications. The symptoms include short stature, typical facies with hypertelorism, saddle nose, short neck, tracheal stenosis and scoliosis. The deformities of airway and thoracic cage are expected to bring about ventilatory failure during anesthesia and operation. Although there has been a brief report of a death of a child with this syndrome during induction of anesthesia, we cannot find any other report concerning the perioperative respiratory management. This is a report on a girl with Conradi's disease who developed respiratory problems due possibly to gastric aspiration during ophthalmic surgery under general anesthesia. Several anesthetic problems raised by this case are discussed.

Anesthesia, General↗
PubMed1988

Enhanced synthesis and secretion of apolipoprotein E from sciatic nerves of streptozotocin-induced diabetic rats after injury.

To elucidate the pathogenesis of diabetic neuropathy, synthesis and secretion of apolipoprotein E (apo E) from sciatic nerves after injury was studied in normal and streptozotocin-induced diabetic rats. Seven, 14, 28, 45 and 59 days after making crush injury on sciatic nerves with concomitant administration of streptozotocin (50 mg/kg body weight), the nerves were taken out and incubated with [35S]methionine. The [35S]labeled apo E was precipitated with specific antiserum. The amounts of apo E secreted into medium by nerves of diabetic rats were 7 times greater than those of non-diabetic rats 7 days after injury. This enhanced secretion of apo E was relatively selective for this protein, since the ratio of the immunoprecipitable apo E to the TCA preciptitable protein in the medium increased in diabetic rats. Intriguing possibility deduced from these results is that the secretion of apo E is involved in the development of diabetic neuropathy.

Animals↗