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Biomedical subjects

M Kitagawa

Publications and source records attributed to M Kitagawa.

At least 19 recordsLinked to original sources

Rapid DNA typing utilizing immobilized oligonucleotide probe and a nonradioactive detection system. Application to HLA-DR typing of the Japanese population.

We established a rapid and simple method of HLA-DR genotyping, and applied it for analysis of the Japanese population. Our method includes rapid preparation of DNA samples from buccal mucosa, incorporation of biotin-dATP into DRB genes during amplification by the polymerase chain reaction, hybridization with sequence-specific oligonucleotide (SSO) probes immobilized on nylon membranes via poly (dT) tails, and detection of the hybridization signal as chemiluminescence. We carried out DR typing of 30 Japanese donors using 20 different immobilized SSO probes, and obtained unambiguous typing signals showing perfect correlation with their serologic DR types. The genotyping also enabled us to identify several DR types unique to the Japanese population, such as DRw12b (DRB1*1202), DRw14c (DRB1*1405), and serology blank type, DR'JX6' (DRB1*1403). The method presented here would be suitable for routine DR typing in tissue-typing laboratories.

Base Sequence

Asbestos fiber analysis in 27 malignant mesothelioma cases.

The asbestos body counts per 5 gm wet lung tissue in 27 (23 pleural and 4 peritoneal) malignant mesothelioma cases derived from 19 autopsy and 8 surgical cases were, according to our own criteria, low level exposure in 13 cases (48.2%), moderate level exposure in 2 cases (7.4%), and high level exposure in 12 cases (44.4%). In our previous study on 235 consecutive autopsy cases, the low level exposure was considered to be environmental, the moderate level was secondary or blue collar, and the high level was occupational. In the present study, about half of the cases examined (44.4%, high level exposure) are closely related to some occupational asbestos exposure and the other half (48.2%) to environmental exposure. The type and size of asbestos fibers from the 12 cases of high level exposure were analyzed and the characteristics were compared with those of cases of low level exposure without lung cancer or mesothelioma. Most fibers analyzed (98%) were longer than 5 microns and thicker than 0.10 micron by our counting rules. In the control group, predominant fibers were tremolite or actinolite. In all the 11 pleural mesothelioma cases, the content of amosite fibers was significantly higher than in the controls. In one case of peritoneal mesothelioma, incipient asbestosis was found and the predominant fibers were crocidolite. It is suggested that the presence of amosite and crocidolite is linked to mesothelioma. The mean lengths of amosite and crocidolite, as detected by our resolution capabilities, were 36.0 and 20.9 microns, and the mean diameters were 0.51 and 0.27 micron, respectively. Both amosite and crocidolite fibers had high aspect ratios (94.2 and 115.4).

Adult

Pancreatic stone predominantly composed of fatty acid calcium.

A 41-year-old man with chronic pancreatitis and pancreatic stones predominantly composed of fatty acid calcium is reported. He had complained of occasional abdominal pain for 10 years and visited the hospital because of a severe attack of abdominal pain. Laboratory data supported a diagnosis of pancreatitis. Computed tomography (CT) showed a high-density area in the head of the pancreas, and the CT number of this high-density area was lower than usual for pancreatic stones. Ultrasonography and endoscopic retrograde pancreatography showed a cystic lesion with small pancreatic stones in the head of the pancreas and irregular dilatation of the main pancreatic duct. Pancreaticojejunostomy and resection of pancreatic cyst were carried out for repeated episodes of abdominal pain under the diagnosis of chronic pancreatitis. The pancreatic stones obtained at surgery were proved to be mainly composed of fatty acid calcium after analysis of chemical composition of the stones. Fatty acid calcium was sometimes found in the biliary stones but never in the pancreatic stones.

Adult

Lung carcinoma with spindle cell components: sixteen cases examined by immunohistochemistry.

Sixteen cases of lung carcinoma with spindle cell components were studied by conventional histochemistry and immunohistochemistry. The epithelial components were squamous cell carcinoma in six cases, adenocarcinoma in four, adenosquamous carcinoma in five, and large cell carcinoma in one. In every case sarcomatous areas were distinctly observed and, in general, neoplastic spindle cells proliferated in close proximity to the epithelial elements. Some of the histochemical procedures suggested mesenchymal features in the stroma of the exophytic portions of three cases, but heterogeneous elements, such as bone or striated muscle, were not observed. By immunohistochemical examination the epithelial elements showed positive reactions for keratin, epithelial membrane antigen, and/or carcinoembryonic antigen to a varying degree according to the histologic types. The spindle cell elements revealed a positive immunoreaction for keratin in all but one case. Epithelial membrane antigen was demonstrated in sarcomatous areas of only five cases and carcinoembryonic antigen was not expressed at all. In contrast, vimentin was distinctly demonstrated in sarcomatous areas of five cases, although other mesenchymal markers, such as desmin, actin, and myosin, were negative. These findings indicate that the spindle cell components in these 16 cases may represent mesenchymal features with partial or complete loss of epithelial features.

Aged

Minimal model analyzing response of glycine receptors expressed in Xenopus oocyte: inhibition by a lipid hydroperoxide.

Glycine receptor (GlyR) was expressed in Xenopus oocytes by injecting rat brain mRNA. Glycine (Gly)-elicited responses in the oocyte were measured by the voltage-clamping method. The following measurements were made to establish the relationship between Gly concentration and the current: 1) Gly-induced membrane current before desensitization, 2) Gly-induced membrane current after desensitization equilibrium, 3) fraction of the active form of the receptor after desensitization equilibrium, 4) rate of recovery of the desensitized receptors upon removal of Gly. These results were analyzed on the basis of the minimal model proposed for nicotinic acetylcholine and gamma-aminobutyric acid A receptor. The equilibrium and rate constants of the model were evaluated for GlyR. The effects of procaine and 13-L-hydroperoxylinoleic acid (LOOH) on GlyR were examined electrophysiologically. LOOH noncompetitively inhibited the receptor with the inhibition constant of 27 microM, while 1 mM procaine, a local anesthetic, did not inhibit GlyR at all.

Animals

Inhibitory effects of triphosphate derivatives of oxetanocin G and related compounds on eukaryotic and viral DNA polymerases and human immunodeficiency virus reverse transcriptase.

In order to clarify the biological activities of (-)-oxetanocin G, and (-)-oxetanocin A and its carbocyclic analogue, (-)-carboxetanocin G, the inhibitory effects of triphosphate derivatives of these compounds (OXT-GTP, OXT-ATP, and C-OXT-GTP) on eukaryotic and viral DNA polymerases were examined. DNA polymerase alpha purified from calf thymus was weakly inhibited by OXT-GTP and OXT-ATP but strongly by C-OXT-GTP, the Ki value being 0.22 microM. On the other hand, rat DNA polymerase beta was not affected by these analogues. DNA polymerase gamma purified from bovine testes was very weakly inhibited by OXT-GTP and OXT-ATP, but not by C-OXT-GTP. DNA polymerase from herpes simplex virus type-II (HSV-II) was strongly inhibited by all three analogues, the Ki values ranging from 0.5 to 1.0 microM. Human immunodeficiency virus-encoded reverse transcriptase (HIV RT) was also strongly inhibited by these three analogues, the Ki value of C-OXT-GTP being slightly smaller than that of OXT-GTP or OXT-ATP. Analysis of products synthesized on singly primed M13 single-stranded DNA by DNA polymerase alpha, HSV-II DNA polymerase or HIV RT in the presence of the analogues revealed that OXT-GTP and C-OXT-GTP were incorporated into DNA and caused chain termination mainly at sites one or two nucleotides beyond the cytosine bases on the template.

Adenine

Nucleotide sequence of the arginine deiminase gene of Mycoplasma hominis.

The arginine deiminase gene of Mycoplasma hominis was amplified by the polymerase chain reaction, and its entire nucleotide sequence was determined. This gene consists of 1227 base pairs encoding 409 amino acids, and has 35.2% guanine plus cytosine content. Nucleotide sequence homologies of the arginine deiminase gene between M. hominis and M. arginini, and between M. hominis and M. orale were 82.1 and 80.8%, respectively, suggesting that this gene is highly conserved among arginine-utilizing Mycoplasma species.

Amino Acid Sequence

Characteristics of 1,3-bis-(2-ethoxycarbonylchromon-5-yloxy)-2-((S)- lysyloxy)propane dihydrochloride (N-556), a prodrug for the oral delivery of disodium cromoglycate, in absorption and excretion in rats and rabbits.

The absorption and excretion of 1,3-bis-(2-ethoxycarbonylchromon-5-yloxy)-2- ((S)-lysyloxy)propane dihydrochloride (N-556), which is a prodrug for the oral delivery of disodium cromoglycate (DSCG), were studied in rats and rabbits. In both animal species, the plasma concentration of DSCG after oral administration of N-556 peaked within 1.0 h, and thereafter declined with a half-life of about 1.2 h in rats and rabbits. The area under the plasma DSCG level versus time curve (AUC) increased in proportion to the dose of N-556 in both animals. The bioavailability of N-556 as calculated from AUC was about 6% in rats and 40% in rabbits, whereas that of DSCG was only 0.1% in rats and 2.5% in rabbits. About 2% and 15% of the dose were respectively excreted as DSCG in the urine and bile after the oral administration of N-556 in rats. The ratio of biliary excretion to urinary excretion (B/U) after the oral administration of N-556 was about twice that after the intravenous injection of DSCG. In rabbits, the urinary and biliary excretions of DSCG after oral administration of N-556 were about 25% and 5%, respectively. The B/U ratio after the oral administration of N-556 in rabbits was similar to that after intravenous administration of DSCG. The difference in the systemic bioavailability of N-556 between rats and rabbits thus appears to be due to a first-pass effect, in addition to a difference in the absorption rate.

Absorption

Primary extramedullary plasmacytoma of the lung.

A case with primary plasmacytoma of the lung is described. The patient, a 55-year-old Japanese female, who simultaneously had a pulmonary plasmacytoma and bladder carcinoma. The bladder tumor was treated with transurethral resection. Pathologically, the bladder tumor was a non-invasive, papillary transitional cell carcinoma, grade II. The lung tumor was located in the right upper lobe and upper lobectomy was performed. The tumor measured 2.8 x 2.7 x 2.0 cm and had a white-yellowish cut surface. Histologic, electron microscopic and immunohistochemical examinations of the lung tumor revealed monoclonal proliferation of plasma cells (IgA, lambda light chain). There was no evidence of multiple myeloma.

Female

Seven patients with plasma cell granuloma (inflammatory pseudotumor) of the lung, including two with intrabronchial growth: an immunohistochemical and electron microscopic study.

Seven patients (mean age, 50.7 +/- 20.4 years; range 21-77) with plasma cell granuloma (PCG) of the lung are reported. Cough and sputum were the most common presenting symptoms, followed by fever. Elevated erythrocyte sedimentation rate and serum C-reactive protein levels were found in all patients tested. Radiologically, five cases presented as solitary, well-circumscribed masses and two as ill-defined, pneumonia-like densities. One showed focal calcification. No predilection of occurrence was observed in either lobe of the lung. Histologically, the lesions consisted of a proliferation of mature plasma cells and reticulo-endothelial cells supported by a stroma of granulation tissue, with varying degrees of myxoid change or collagenization. Angioinvasion within the lesion was observed in 4 of the 7 cases. Immunohistochemical staining revealed the IgG-predominant polyclonal nature of the plasma cells, indicating a reactive inflammatory process rather than a neoplastic one. Electron microscopy confirmed the benign nature of the plasma cells with fibroblast and myofibroblast proliferation admixed with that of other inflammatory cells.

Adult

"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

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

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

[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

[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

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