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Biomedical subjects

M Kitagawa

Publications and source records attributed to M Kitagawa.

At least 379 records · Page 21Linked to original sources
PubMed1992

"True" posterior communicating artery aneurysm--report of two cases.

Two cases of true posterior communicating artery (PcomA) aneurysm are described. A 27-year-old female with subarachnoid hemorrhage demonstrated a saccular aneurysm at the branch of the anterior choroidal artery from the PcomA. The aneurysm was successfully clipped. A 23-year-old male involved in an automobile accident suffered from traumatic subarachnoid hemorrhage. Computed tomography 10 weeks after head injury demonstrated a high-density mass in the right parasellar region, diagnosed as a traumatic aneurysm arising from the PcomA. The aneurysm was successfully clipped. Histological examination demonstrated findings consistent with true aneurysm.

Accidents, Traffic↗
PubMed1992

Blood levels and urinary excretion of thiamin and riboflavin during oral administration of multivitamin tablets to healthy adults.

1. The baseline blood thiamin concentration increased gradually during the long-term administration of TTFD, and the blood concentration was dose-dependent. The cumulative urinary thiamin excretion showed the same dose-dependence as the blood concentration. 2. The baseline blood riboflavin concentration also increased steadily during the administration period, but the increase was less than that of thiamin. Dose-dependence of the cumulative urinary excretion of riboflavin was noted. 3. No side effect were observed.

Administration, Oral↗
PubMed1992

Effects of calmodulin inhibitors on amylase secretion from rat pancreatic acini.

To investigate the role of calmodulin in stimulus-secretion coupling in pancreatic acinar cells, we studied the effects of W-7, a calmodulin inhibitor, and KN-62, a specific inhibitor of Ca2+/calmodulin-dependent protein kinase II (Ca2+/CaM kinase II), on amylase secretion from rat pancreatic acini. Calmodulin inhibitor (W-7, 100 microM) and Ca2+/CaM kinase II inhibitor (KN-62, 10 microM) reduced amylase secretion stimulated by cholecystokinin (CCK) or carbachol. W-7 and KN-62 also inhibited amylase secretion stimulated by both calcium ionophore (A23187) and phorbol ester (12-O-tetradecanoylphorbol-13-acetate, TPA). To clarify the role of calmodulin in the interaction of intracellular mediators, pancreatic acini were permeabilized with streptolysin O. Following permeabilization, amylase secretion was stimulated by submicromolar free Ca2+, and this Ca(2+)-dependent amylase secretion was enhanced by guanosine 5'-[gamma-thio]triphosphate (GTP gamma S), TPA or cyclic adenosine 3',5'-monophosphate (cAMP). W-7 and KN-62 had no effects on amylase secretion stimulated by Ca2+ alone, but inhibited the enhancement in Ca(2+)-dependent amylase secretion by GTP gamma S, TPA or cAMP. These data suggest that calmodulin plays an important role in Ca(2+)-dependent amylase secretion from pancreatic acinar cells and in the interaction between Ca2+ and other intracellular messengers.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

[Molecular biological studies on expression of placental CRF gene and its product].

Corticotropin releasing factor, a neuropeptide secreted by the hypothalamus, was recently found to be also secreted by the placenta. However, the biological role of placental CRF is obscure. In this study, we performed Northern blots and in situ hybridizations to determine the time course and site of placental CRF production. Then we measured maternal and fetal CRF, ACTH, cortisol and DHAS levels during the course of pregnancy. The results of these studies indicated that placental CRF mRNA is 1.5 kb in size and its expression increases dramatically near term. It was shown that placental CRF is transcribed in the cytotrophoblast layer. Both maternal and fetal CRF, ACTH and cortisol increased near term. The DHAS level was significantly higher on the fetal side than in the maternal plasma. It was assumed that on the maternal side, placental CRF activates the basal level of the pituitary-adrenal axis to produce more corticosteroids. The increased corticosteroids may compete with progesterone receptors and cause the removal of a progesterone block of uterine muscle contraction. On the fetal side, placental CRF activates the pituitary-adrenal axis to produce corticosteroids and DHAS. The increased corticosteroids may again compete with progesterone receptors. The increased DHAS directly affects the uterine cervix to cause ripening of it.

Adrenocorticotropic Hormone↗
PubMed1992

[A case of tracheobronchopathia osteoplastica discovered after difficulty in intubation].

A 77-year-old man was scheduled for Love's method to correct lumbar disc herniation. He had fracture of maxilla and mandibula during World War II. Physical examination and laboratory data revealed no abnormalities. Anesthesia was induced with oxygen, nitrous oxide and halothane. Following administration of succinylcholine, an attempt was made to insert a tracheal tube (from 8.5mm to 5.5mm), but the tubes were met with an obstruction. The operation was cancelled because tumor-like nodules were seen in the trachea. Diagnosis of tracheobronchopathia osteoplastica was made afterwards following biopsy. The patient with this disease has a good prognosis. Artificial ventilation can be performed safely by choosing an appropriate method for airway maintenance.

Aged↗
PubMed1992

Vascular wall arachidonic acid metabolism and fetal growth in the pregnant STZ-induced diabetic rat.

In pregnant women with severe diabetes mellitus, intrauterine growth retardation (IUGR) may occur despite hyperglycemia. Uterine blood flow may be an important factor in this process. Using pregnant streptozotocin-induced diabetic rats (pregnant STZ-diabetic rats), we evaluated functional and morphological changes in the endothelium, as well as platelet thromboxane A2 (TXA) production and their influence on uterine blood flow. Decreased basal endothelial prostacyclin (PGI2) production as well as significant attenuation of the production response to stimulus was noted, suggesting an impairment of PGI2 production. In the platelet, TXA2 production was augmented, leading to a hypercoagulable state. Decreased myometrial blood flow was documented. Scanning electron microscopy (SEM) revealed definite morphological abnormality of the endothelial cells, probably affecting the permeability to molecules, a major endothelial function. Based on these data, the endothelial derangements suggested by SEM and arachidonic acid metabolism alterations may affect fetal growth in the severe pregnant diabetic through alterations in uterine blood flow.

Animals↗
PubMed1992

[Correlation between clinical features and neuroradiological findings in juvenile muscular atrophy of unilateral upper extremity (Hirayama disease)--with and without "tight dural canal in flexion"].

Myelography was performed in 12 patients with juvenile muscular atrophy of unilateral upper extremity. Seven patients showed anterior shift of lower cervical dural canal in flexion (tight dural canal in flexion) (T group), however the other 5 patients did not show "tight dural canal in flexion" (NT group). Onset of illness and sex were not different between 2 groups. However, there was a tendency that the neurological signs and symptoms were more severe in the patients of T group than those of NT group. These results suggest that "right dural canal in flexion" can be one of mechanisms which exhibit the clinical symptoms of the juvenile muscular atrophy of unilateral upper extremity. However, there may be other etiological factors in the juvenile muscular atrophy of unilateral upper extremity.

Adolescent↗
PubMed1992

Aqueous solubility and acidity constants of cholic, deoxycholic, chenodeoxycholic, and ursodeoxycholic acids.

Cholic acid, deoxycholic acid, chenodeoxycholic acid, and ursodeoxycholic acid were purified by a foam fractionation method. Using thermogravimetric analysis, the attached water molecule was found to be completely removed from solids of the latter three at 100 degrees C, while cholic acid still had one water molecule of crystallization per two cholic acid molecules at that temperature. The acidity constants of the acids were accurately determined from aqueous solubility measurements at different pH values and at 15, 25, 35, and 45 degrees C. The enthalpy change of dissolution from temperature dependence of solubility as undissociated acid monomer was much less than those of common ionic surfactants. This results from a smaller entropy increase on dissolution due to the hardly flexible hydrophobic structure of these bile acids.

Calibration↗
PubMed1992

cdc2-like kinase is associated with the retinoblastoma protein.

The growth-suppressive activity of the retinoblastoma (RB) protein is suggested to be regulated by phosphorylation. In studies on the kinase that phosphorylates the RB proteins, we have previously found that RB proteins can be phosphorylated by purified cdc2 kinase. In this study, we noted that RB proteins immunoprecipitated from human cell lysates are weakly phosphorylated in the absence of purified cdc2 kinase. Immunoblot analysis showed the presence of p34cdc2 in the immunoprecipitates with anti-RB monoclonal antibody. In addition, the coprecipitated kinase was found to have the same substrate specificity as cdc2 kinase. The associated kinase activity was particularly high in cells arrested in G1/S and S phase by aphidicolin. Furthermore, RB proteins were shown to be phosphorylated in nuclear extracts by some endogenous cdc2-like kinase(s). These results suggest that cdc2-like kinase is the main kinase for phosphorylation of RB proteins in vivo.

Amino Acid Sequence↗
PubMed1991

A case of T-cell lymphoma accompanying marked eosinophilia, chronic eosinophilic pneumonia and eosinophilic pleural effusion. A case report.

A 57-year-old woman was admitted to our hospital for lumbago, weight loss and weakness of her right lower extremity. Leukocytosis was evident with marked eosinophilia (65.5% = 46,000/mm3), and the chest roentgenogram showed diffuse reticular shadows throughout both lung fields and a left pleural effusion. The pleural effusion contained 22.4% eosinophils with no immature cells. Biopsy of a thumb-sized mass on the chest wall revealed a T-cell lymphoma of pleomorphic type. The diffuse pulmonary shadow was diagnosed as chronic eosinophilic pneumonia by autopsy. This was a relatively rare case of T-cell lymphoma, in which an eosinophilic pneumonia and eosinophilic pleural effusion were observed.

Chronic Disease↗
PubMed1991

rig encodes ribosomal protein S15. The primary structure of mammalian ribosomal protein S15.

rig, a gene originally isolated from a rat insulinoma cDNA library, codes for a basic 145 amino acid protein [( 1986) Diabetes 35, 1178-1180]. Here we show that the immunoreactivity to a monoclonal antibody against the deduced rig protein and the translation product of rig mRNA comigrated with ribosomal protein S15. The amino acid sequence of ribosomal protein S15 purified from rat liver coincided with that deduced from the nucleotide sequence of rig mRNA, but there were indications that the initiator methionine was removed and the succeeding alanyl residue was monoacetylated. From these results, we conclude that the product of rig is ribosomal protein S15.

Amino Acid Sequence↗
PubMed1991

Spindle cell carcinoma of the lung. A clinicopathologic study of three cases.

Two cases of monophasic spindle cell carcinomas and one case of adenosquamous carcinoma with the spindle cell component located in the lower respiratory tract are presented. In the biphasic tumor, areas of transition from carcinoma to sarcomatous spindle cells were clearly found. The two monophasic tumors and the spindle cell component of the biphasic tumor were histologically characterized by sheets of spindle cells. However, by electron microscopic and immunohistochemical study, several features of squamous epithelial differentiation were found in the spindle cell areas of all cases. Keratin and vimentin were, in various degrees, coexpressed in all the cases. Therefore, it is supposed that the spindle cell component displays a spectrum of phenotypes originating from squamous cell carcinoma, and monophasic spindle cell carcinoma is considered as a kind of the extreme phenotype of squamous cell carcinoma pretending mesenchymal differentiation.

Adenocarcinoma↗
PubMed1991

Mechanism of inhibition of human cytomegalovirus replication by oxetanocin G.

Oxetanocin G(9-(2-deoxy-2-hydroxymethyl-beta-D-erythro-oxetanosyl)guanine, OXT-G) is a potent and selective agent against human cytomegalovirus (HCMV). In this study we synthesized the triphosphate form of OXT-G, OXT-GTP, and examined its effect on the activities of HCMV DNA polymerase, herpes simplex type 2 (HSV-2) DNA polymerase and human DNA polymerase alpha. OXT-GTP was found to inhibit all these polymerases in a competitive manner with respect to dGTP. The Km for dGTP and the Ki for OXT-GTP of HCMV DNA polymerase were 0.86 and 0.53 mu M, respectively, while the corresponding values of DNA polymerase alpha were 2.2 and 3.6 mu M, respectively. HPLC analysis using [3H]OXT-G also revealed that OXT-G was converted to its triphosphate form 7- to 8-fold more efficiently in HCMV-infected cells than in uninfected cells. The results suggest that both the preferential phosphorylation of OXT-G in HCMV-infected cells and the preferential inhibition of HCMV DNA polymerase by OXT-GTP may contribute towards the selective activity of OXT-G against HCMV replication.

Antiviral Agents↗
PubMed1991

Interactions of intracellular mediators of amylase secretion in permeabilized pancreatic acini.

Mouse pancreatic acini were permeabilized with streptolysin O to investigate amylase secretion stimulated by various intracellular mediators and the kinetics of secretion as a function of temperature. Amylase secretion was temperature dependent in that the initial rate of Ca2(+)-stimulated secretion increased with increasing temperature. In addition, there was no enhancement of Ca2(+)-stimulated secretion by GTP[gamma S] at 14 degrees C, while enhancement was maximal at 30 degrees C. GTP[gamma S]-mediated enhancement of secretion at a given temperature was mostly due to sustained secretion with a small increase in secretory rate. At 30 degrees C Ca2(+)-stimulated secretion was also enhanced by cAMP and phorbol ester (TPA) to similar extents as by GTP[gamma S]. The maximally effective concentration of cAMP was 1-10 microM in the presence of 0.1 mM isobutylmethylxanthine. The enhancements of Ca2(+)-stimulated amylase secretion by all combinations of cAMP (100 microM plus 0.1 mM isobutylmethylxanthine), TPA (1 microM), and GTP[gamma S] (30 microM) were fully additive. In Ca2(+)-free buffer, cAMP, TPA or GTP[gamma S] individually had no effect on amylase secretion. Together, TPA and GTP[gamma S] stimulated Ca2(+)-independent secretion, which was 187 +/- 38% of basal. Cyclic AMP together with TPA and GTP[gamma S] in the absence of Ca2+ stimulated 329 +/- 30% of basal secretion. Ca2(+)-stimulated amylase secretion was decreased about 50% by metabolic inhibition, while the enhancement by cAMP, TPA or GTP[gamma S] was totally blocked by metabolic inhibitors. These data demonstrate that amylase secretion in the acinar cell is mediated by multiple intracellular pathways which act in parallel and probably converge at a distal step in the exocytotic process.

Adenosine Triphosphate↗
PubMed1991

Iron as a possible aggravating factor for osteopathy in itai-itai disease, a disease associated with chronic cadmium intoxication.

Itai-itai disease is thought to be the result of chronic cadmium (Cd) intoxication. We examined 23 autopsy cases of itai-itai disease and 18 cases of sudden death as controls. Urine and blood samples from 10 patients were collected before they died and revealed the presence of severe anemia and renal tubular injuries. Undecalcified sections of iliac bone were stained with Aluminon reagent, and ammonium salt of aurintricarboxylic acid, and Prussian blue reagent in all cases of itai-itai disease. These two reagents reacted at the same mineralization fronts. X-ray microanalysis revealed the presence of iron at mineralization fronts in itai-itai disease. Five patients showed evidence of hemosiderosis in the liver, spleen, and pancreas, probably as a result of post transfusion iron overload. Renal calculi and calcified aortic walls were also stained with Prussian blue reagent in several patients. Neither ferritin nor transferrin were visualized at mineralization fronts in itai-itai disease by immunohistochemical staining. These results suggest that iron is bound to calcium or to calcium phosphate by a physicochemical reaction. A marked osteomalacia was observed in 10 cases of itai-itai disease by histomorphometry. Regression analyses of data from cases of itai-itai disease suggested that an Aluminon-positive metal inhibited mineralization and that renal tubules were injured. Since bone Cd levels were increased in itai-itai disease, it is likely that renal tubules were injured by exposure to Cd. Therefore, stainable bone iron is another possible aggravating factor for osteopathy in itai-itai disease, and a synergistic effect between iron and Cd on mineralization is proposed.

Aged↗
PubMed1991

Early hilar lung cancer: its clinical aspect.

Early hilar lung cancers are rare, but are curable if they are properly diagnosed and treated. In the past 14 years, we have treated 27 patients with early hilar cancers that fulfilled the criteria proposed by the Japanese Lung Cancer Society (JLCS). Eighteen patients presented with symptoms and 9 were detected by the mass screening examination of sputum cytology. All lesions in both groups were finally diagnosed by bronchoscopy. Twenty patients (74%) had positive sputum cytology, whereas only 7 (26%) had positive chest X-ray findings. All the patients underwent surgery, and bronchoplasty was the most frequent operative procedure. The 5-year survival rate was 100%, and the 10-year survival rate was 91.7%, as one patient died of a second primary lung cancer in the 6th postoperative year. In conclusion, the definition of early hilar lung cancer proposed by the JLCS is thought to be reasonable, and early hilar lung cancer is a curable disease, if it is properly diagnosed and treated.

Bronchoscopy↗