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Biomedical subjects

S Kitagawa

Publications and source records attributed to S Kitagawa.

At least 217 records · Page 12Linked to original sources
PubMed1991

Changes in orientation of the major interlobar fissure in chronic liver diseases.

The orientation of the major interlobar fissure, as an indicator of right lobar atrophy, was evaluated using axial MR imaging in 64 patients with histologically proven chronic liver diseases. The "interlobar fissure angle" was determined by a line drawn through the middle hepatic vein and inferior vena cava and a horizontal line at the level of hepatic hilus. The angle was significantly smaller in cirrhosis than in either chronic persistent or active hepatitis. A much smaller angle was observed in cirrhosis associated with colonic interposition. The increasing incidence of small "interlobar fissure angle" (less than 30 degrees) was observed to parallel the histological stages from chronic persistent hepatitis to liver cirrhosis. All the cirrhotic patients with colonic interposition and an angle of less than 30 degrees. This simple method is considered useful in the diagnosis of right lobar atrophy and disease severity in chronic liver disease.

Adult↗
PubMed1991

Colorectal carcinomas incidentally detected in autopsied cases and inpatients.

During the past 20 yr, 17 colorectal carcinomas (0.47%) were incidentally detected among 3,638 autopsied patients without clinically evident colorectal carcinoma, including 2,232 males and 1,406 females, more than 40 yr old. Among the 15 male and two female index subjects, six (0.33%) were detected in the first and 11 (0.60%) in the second decade. During their survival periods, fecal occult blood studies were performed in 14 cases and positive in 12 (86%); however, two of them had gastric ulcers which were responsible for the occult blood. During the recent 11 yr, six cases (0.48%) of colorectal carcinoma (four of them males; two, females) also were detected among 1,249 inpatients who were examined by barium enema and/or colonoscopy, including 816 males and 433 females, 40 yr old, or more, in the Department of Radiology. Fecal occult blood was detected in four cases (67%) before colonic investigation. Compared with 708 surgically resected carcinomas, the incidental lesions from both sources were smaller, consisted of higher percentages of Dukes' A type, and arose predominantly from the sigmoid colon and, rarely, from the rectum. These results indicate that the prevalence of colorectal carcinoma and its predominance in the sigmoid colon have not only apparently but actually increased in Japan, apart from improved diagnostic capabilities, and that false-negative rates with occult blood tests were surprisingly low in these autopsied cases and inpatients.

Aged↗
PubMed1990

Synthetic sialyl glycolipids (sialo-cholesterol and sialo-diglyceride) induce granulocytic differentiation of human myelogenous leukemia cell line HL-60.

When HL-60 cells were cultivated with synthetic sialyl glycolipids, sialo-cholesterol and sialo-diglyceride, the cells were found to be differentiated into mature granulocytes on morphological and functional criteria. The differentiation of cells was accompanied by inhibition of cell proliferation. The differentiation-inducing activity of sialo-cholesterol was greater than that of sialo-diglyceride on a molar basis, and the alpha-anomer of each compound was more potent than the beta-anomer, suggesting that the stereospecific structure of the compounds is important for the differentiation-inducing activity.

Cell Transformation, Neoplastic↗
PubMed1990

Stimulation and priming of human neutrophils by granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor: qualitative and quantitative differences.

Granulocyte colony-stimulating factor(G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) increased neutrophil C3bi-receptor expression and adherence and rapidly (less than 10 min) primed neutrophils to enhanced O2- release and membrane depolarization stimulated by chemotactic peptide. Direct triggering of O2- release in suspended neutrophils was also provoked by GM-CSF but not by G-CSF. GM-CSF-induced O2- release was inhibited by cyclic AMP agonists and cytochalasin B. The biological activity was greater in non-glycosylated GM-CSF than in glycosylated GM-CSF, whereas it was identical in glycosylated and non-glycosylated G-CSFs. Direct stimulation and priming by GM-CSF were consistently greater than those by G-CSF and the combined addition of the optimal concentrations of G-CSF and GM-CSF resulted in the effects of GM-CSF alone. These findings indicate that the effects of G-CSF and GM-CSF on neutrophil functions are qualitatively and quantitatively different from each other.

Alprostadil↗
PubMed1990

ESR analysis with long-chain alkyl spin labels in bovine blood platelets. Relationship between the increase in membrane fluidity by alcohols and phenolic compounds and their inhibitory effects on aggregation.

Four spin-labeled probes (5-doxylstearic acid (5-NS), its methyl ester (5-NMS), 16-doxylmethylstearate (16-NMS) and 4-(N,N-dimethyl-N-pentadecyl)ammonium-2,2,6,6-tetramethylpiperidine-1-ox yl (CAT-15)) were used to monitor membrane fluidity change in bovine platelets induced by three alkyl alcohols, benzyl alcohol and two phenolic compounds. The relationship between the increase in membrane fluidity induced by these compounds and their inhibitory effects on platelet aggregation was observed. Experiments with the four probes showed that n-hexyl alcohol induced decreases in the order parameter of 5-NS and apparent rotational correlation times of the other probes at the same minimal alcohol concentration. The decreases were observed in the concentration range that inhibited aggregation. n-Amyl alcohol and n-butyl alcohol decreased the values of the parameters of the above mentioned only at higher concentrations that were dependent on their hydrophobicities. Like alkyl alcohols, benzyl alcohol and phenolic compounds decreased the values of the parameters in the concentration ranges in which these compounds inhibited platelet aggregation. The concentration of these compounds causing 50% inhibition of platelet aggregation, the IC50 values, and data on 5-NS-labeled platelets indicated that they inhibited aggregation and decreased the value of the order parameter at lower concentrations relative to their Poct values in comparison to the effective concentrations of alcohols. Phenolic compounds also decreased the values of the apparent rotational correlation times of 5-NMS and 16-NMS. These results indicate that the inhibition of platelet aggregation by alcohols and phenolic compounds is due to membrane perturbation in wide range in depths within the lipid bilayer.

Alcohols↗
PubMed1990

Inhibitory mechanism of cis-polyunsaturated fatty acids on platelet aggregation: the relation with their effects on Ca2+ mobilization, cyclic AMP levels and membrane fluidity.

The in vitro inhibitory effects of cis-polyunsaturated fatty acids, linolenic (18:2 delta 9,12), alpha-linoleic (18:3 delta 9,12,15) and eicosatrienoic (20:3 delta 11,14,17) acid, on bovine platelet aggregation and their inhibitory mechanism were investigated. These fatty acids inhibited platelet aggregation induced by ADP and thrombin to similar extent. Fluorescence analyses with fura-2-loaded platelets showed that, in the concentration ranges that inhibited aggregation, they also inhibited agonist-induced increase in cytoplasmic Ca2+. According to radioimmunoassay study, addition of these fatty acids increased cyclic AMP contents in the presence of theophylline corresponded with their inhibitory effects on aggregation. These fatty acids induced a 1.6-1.8-fold increase over basal concentration of cyclic AMP in the concentration ranges that fully inhibited aggregation. On the other hand, saturated fatty acid, stearic acid, affected neither aggregation nor cyclic AMP levels. As reported previously [1985) Biochim. Biophys. Acta 818, 391), these unsaturated fatty acids induced increase in membrane fluidity in the same concentration range. These results suggest that inhibition of platelet aggregation by cis-polyunsaturated fatty acids is due to the increase in cyclic AMP levels. This increase seems to be due to stimulation of adenylate cyclase which is mediated by membrane perturbation.

8,11,14-Eicosatrienoic Acid↗
PubMed1990

Induction of anti-allo-class I H-2 tolerance by inactivation of CD8+ helper T cells, and reversal of tolerance through introduction of third-party helper T cells.

The intravenous sensitization of C57BL/6 (B6) mice with class I H-2-disparate B6-C-H-2bm1 (bm1) spleen cells resulted in the abrogation of CD8+ T cell-mediated anti-bm1 (proliferative and interleukin 2-producing) T helper (Th) cell activities. In vitro stimulation of lymphoid cells from these mice with bm1 cells, however, generated a reduced, but appreciable, anti-bm1 cytotoxic T lymphocyte (CTL) response. Moreover, the anti-bm1 CTL response, upon stimulation with [bm1 x B6-C-H-2bm12 (bm12)]F1 spleen cells, was enhanced when compared with the response induced upon stimulation with bm1 cells. These in vitro results were reflected on in vivo graft rejection responses; bm1 skin grafts engrafted in the bm1-presensitized B6 mice exhibited prolonged survival, whereas (bm1 x bm12)F1 grafts placed collateral to bm1 grafts (dual engrafted mice) inhibited the tolerance to bm1. In the B6 mice 1-2 d after rejecting the bm1 grafts, anti-bm1 Th activities remained marginal, whereas potent anti-bm1 CTL responses were found to be generated from their spleen cells. Administration in vivo of anti-CD4 antibody into bm1-presensitized, dual graft-engrafted mice prolonged bm1 graft survival and interfered with enhanced induction of anti-bm1 CTL activity. These results indicate that anti-class I alloantigen (bm1) tolerance as induced by intravenous presensitization with the relevant antigens is not ascribed to the elimination of CD8+ CTL precursors, but to the specific inactivation of CD8+ Th cells, whose function can be bypassed by activating third-party Th cells.

Animals↗
PubMed1990

Requirement of the thymus for the recovery of anti-alloantigen helper T cells from tolerance induced by intravenous presensitization with allogeneic cells.

Intravenous presensitization of C57BL/6 (B6) mice with class I H-2-disparate B6-C-H-2bm1 (bm1) whole spleen cells and class II H-2-disparate B6-C-H-2bm12 (bm12) spleen cells depleted of APC resulted in almost complete elimination of the respective anti-bm1 and anti-bm12 reactivities. However, the reduced alloreactivities as assessed by Th cell capacities (proliferative responses and IL-2 production) were recovered around 8 wk after the i.v. presensitization in euthymic B6 mice. In contrast, background levels of bm1- or bm12-specific reactivities were revealed to last more than 12 wk after the presensitization in B6 mice which had been thymectomized prior to the i.v. presensitization. Such a reduced alloreactivity was also observed in the capacity to reject bm1 or bm12 skin grafts, and prolongation of graft survival was strikingly enhanced in the thymectomized group compared to that induced in the nonthymectomized group. However, there was an important difference in such prolongation in the thymectomized hosts between bm1 and bm12 grafts; a considerable percentage (greater than 80%) of bm12 skin grafts continued to take more than 5 mo, whereas about 90% of bm1 grafts were rejected by around 5 mo along with the emergence of weak, but detectable anti-bm1 Th and cytotoxic T cell activities. These results indicate that 1) i.v. presensitization regimen is capable of eliminating in vitro and in vivo alloreactive capabilities but these alloreactivities can be recovered in euthymic hosts with T cell repopulating potential and 2) there are differential requirements of the thymus for repopulating anti-bm1 (Lyt-2+) and anti-bm12 (L3T4+) T cell activities.

Animals↗
PubMed1990

Prolonged preservation of cadaver heart with Belzer UW solution: 24-hour storage system for asphyxiated canine hearts.

The efficacy of Belzer UW solution was compared to Collins' solution in the preservation of asphyxiated cadaver hearts in a canine model. Donor hearts were stored for 24 h: 2 h of in situ hypothermic (15 degrees C) coronary perfusion plus 22 h of simple immersion in ice-cold solution. Verapamil, propranolol and prostacyclin were used for myocytoprotection in both groups. After orthotopic transplantation, all animals were weaned off bypass without inotropic support. After 1 h, however, the cardiac output was significantly higher in the Belzer UW solution group (128 +/- 28 vs. 67 +/- 13 ml/kg/min, p less than 0.01).

Adenosine↗
PubMed1990

Atherosclerosis mouse model induced by a high-cholesterol diet supplemented with beta-aminopropionitrile: effects of various anti-atherosclerotic agents on the biochemical parameters.

A mouse model of atherosclerosis was produced by feeding a 1.5% cholesterol diet with 0.4% beta-aminopropionitrile (BAPN) fumarate, a chemical lathyrogen, for 10 weeks, and the pharmacological sensitivity and specificity of this model were evaluated biochemically with various hypolipidemic drugs and calcium antagonists. Histological findings on this model showed typical angiolathyrism with foam cells in the media of the thoracic aorta. Uniform and marked accumulation of cholesterol, notably esterified cholesterol, in the aorta was observed, although it was much less in mice receiving a high-cholesterol diet or BAPN alone. The reduction in elastin contents in the aorta was a characteristic feature of this model. Clofibrate, cetaben and elastase tended to prevent the increase of cholesterol contents in the aorta, together with their significant hypocholesterolemic effects. Nifedipine, diltiazem and verapamil showed a slight preventive effect on the cholesterol accumulation and on the reduction of elastin content in the aorta without a cholesterol lowering effect in the serum. MgCl2 was more effective than other calcium antagonists and even had a hypocholesterolemic effect. The results indicate that this mouse atherosclerosis model may be usable for primary drug evaluation.

4-Aminobenzoic Acid↗
PubMed1990

[Pharyngeal area measured by acoustic reflection technique while breathing room-air].

Although there have been many reports on the airway area measured by breathing 80% He-20% O2 (He-O2) using the acoustic reflection technique (ART), there have been no reports on that by breathing room-air (Air) because of the lack of accuracy in evaluating the trachea. When measuring with He-O2, accidental introduction of Air into the airway makes the measurement inaccurate. Moreover, it is a time-consuming method and is hardly applicable to dyspneic patients. Therefore, we tried to assess whether the airway area, especially the upper airway, can be measured while breathing Air. In order to compare the areas determined by the two methods, area-distance functions from the pharynx to the trachea were arbitrarily divided into 9 divisions at interval of 2.8 cm. Each of these divisions was respectively compared. We took averages of the pharyngeal, tracheal areas in 8 normal subjects. We found no significant difference between the oropharyngeal area measured by breathing Air and that measured by breathing He-O2, and found a significant correlation between them. There was a significant correlation between the hypopharyngeal areas when using the two methods. The average tracheal area by breathing Air is 4.96 +/- 0.50 cm2, which is 40% above that when measured using He-O2 (3.55 +/- 0.32 cm2). In contrast, the average pharyngeal area when breathing Air is 4.13 +/- 0.93 cm2, which overestimates that by breathing He-O2, namely 3.54 %/- 0.84 cm2 by only 17%. In conclusion, it is possible and useful to estimate the pharyngeal area by breathing Air.

Acoustics↗
PubMed1990

[Clinico-pathological study of xanthogranulomatous cholecystitis].

Xanthogranulomatous cholecystitis (XGC) is an uncommon lesion which may form a tumor-like mass in inflamed gallbladders. In a review of 44 cases there were 40 associated with gallstones which had been incarcerated in the neck of the gallbladder, 10 with past histories of abdominal surgeries, 15 with diabetes mellitus, three with carcinomas in the neck of the gallbladder and four with carcinomas in the other organs. Radiologically the differential diagnosis of gallbladder cancer and XGC was difficult in several cases. Thirty five cases of XGC have been diagnosed as chronic cholecystitis and 7 have been mistaken for feature of XGC in the contrast enhancement CT that is, detection of an intramural low density mass with continuously enhanced internal membraneous layer of the gallbladder wall. In view of the clinico-pathological findings of XGC, the lesions appear to result from intramural extravasation of bile and subsequent xanthogranulomatous reaction under obstructive conditions in the neck of the gallbladder. We conclude that XGC is not an uncommon special type of cholecystitis but an accompanied lesion sometimes seen in a kind of cholecystitis.

Adult↗
PubMed1990

[Congenital atresia of the left main coronary artery ostium--a case suffering from ventricular tachycardia].

A case of congenital atresia of the left main coronary ostium suffering from ventricular tachycardia underwent coronary artery bypass operation. The patient was 17 years old boy. When he was 9 years old he visited our department for the purpose of examining cardiac disease. The diagnostic impression was mitral regurgitation. At 16 years old he suddenly complained tachycardia during exercise. He admitted to our hospital and the tachycardia was proved to be ventricular tachycardia. Left ventriculogram demonstrated a small range of akinesis at the left ventricular apex. And coronary cineangiogram revealed atresia of the left main coronary artery. The left coronary artery was perfused with collateral circulations from right coronary artery. Electrophysiological study was performed. The ventricular tachycardia could be reproducibly initiated and terminated by programmed stimulation. The catheter endocardial mapping was also performed. The source of ventricular tachycardia was supposed to be at the left ventricular apex. At 18 years old coronary artery bypass operation was performed. Internal mammary artery graft was placed to the left anterior descending artery and a saphenous vein graft was placed from the ascending aorta to the left circumflex artery. A small size of myocardial infarction was recognized at the left ventricular apex. And epicardial mapping revealed that the source of arrhythmia was the same region as the myocardial infarction was recognized. Endocardial resection or cryoablation was not performed. Post-operative study was performed 8 months after surgery. The graft flow of the internal mammary artery to the left anterior descending artery was not sufficient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[A rare case of congenital tricuspid stenosis treated with modified Fontan operation].

A rare case of congenital tricuspid stenosis treated with modified Fontan operation was reported. The patient was 13 years old boy and his chief complaint was cyanosis. Cyanosis appeared in his neonatal period and squatting developed in his childhood. He underwent Blalock's shunt operation at 5 years of age. His exercise tolerance was limited at the admission for the radical operation. Angiocardiography showed the annular stenosis of tricuspid valve and the moderate hypoplasia of right ventricle. The right ventricular volume was 56 ml (equivalent to 35% of the normally expected right ventricular volume) and the diameter of tricuspid annulus was 13 mm (equivalent to 58% of the normally expected diameter). Atrial septal defect was associated with but pulmonary stenosis did not exist. His left ventricular function was good and pulmonary vascular resistance was not raised. A diagnosis of tricuspid stenosis was made and Fontan's repair was considered to be possible for his correction. Operative findings showed normal architecture of tricuspid valve with the three leaflets but tricuspid annulus was narrow. Tricuspid valve stenosis was considered to be caused by the hypoplasia of tricuspid ring and surgical dilatation was found to be difficult. Therefore, modified Fontan operation (RA-RV connection) was performed. His cyanosis disappeared and exercise tolerance was improved after the operation. Cardiac catheterization and angiocardiography were performed 8 months and 28 months after the operation. His righ ventricular volume was increased to 123 ml (equivalent to 57% of the normally expected volume) followed by RA-RV connection.

Adolescent↗