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Biomedical subjects

T Iijima

Publications and source records attributed to T Iijima.

At least 289 records · Page 16Linked to original sources
PubMed1992

Repeated negative DC deflections in rat cortex following middle cerebral artery occlusion are abolished by MK-801: effect on volume of ischemic injury.

Following permanent occlusion of the left middle cerebral artery (MCA) in rats, electrophysiological and hemodynamic characteristics of the periinfarct border zone were investigated in sham-operated (n = 6), untreated (n = 6), and MK-801-treated (3.0 mg/kg; n = 6) animals. For this purpose, direct current potential (DC), EEG, and blood flow (laser-Doppler flowmetry) were recorded from the cortex in the periphery of the MCA territory. In sham-operated rats, a single negative cortical DC deflection was observed after electrocoagulation of the cortex, whereas in untreated MCA-occluded animals, three to eight transient DC deflections were monitored during the initial 3 h of ischemia. The duration of these cortical DC shifts gradually increased from 1.2 +/- 0.3 to 3.7 +/- 2.7 min (mean +/- SD; p less than 0.05) during this time. In animals treated intraperitoneally with MK-801 (3.0 mg/kg) immediately after MCA occlusion, the number of cortical DC shifts significantly declined to one to three deflections (p less than 0.005). The EEG of the treated animals revealed low-amplitude burst-suppression activity. In the untreated and treated experimental group, the reduction of cortical blood flow amounted to 69 +/- 25 and 49 +/- 13% of control, respectively. Despite the more pronounced cortical oligemia, MK-801 treatment resulted in a significant decrease of the volume of the ischemically injured tissue from 108 +/- 38.5 (untreated group) to 58 +/- 11.5 (p less than 0.05) mm3. Our results suggest that repetitive cortical DC deflections in the periinfarct border zone contribute to the expansion of ischemic brain infarcts.

Action Potentials↗
PubMed1992

[Effect of lipiodol-cisplatinum arterial infusion chemotherapy on cellular immunity].

A Lipiodol-cisplatinum suspension (LPD/CDDP) was applied by intrahepatic arterial infusion chemotherapy to treat 15 cases of inoperable hepatoma. Pre- and post-application changes in leucocytes, monocytes, platelets and lymphocytes in patients were examined. Natural killer activity was determined and analysis by two-color method was performed. After infusion chemotherapy, leucocytosis and monocytosis were quite conspicuous. NK activity was reduced after application of LPD/CDDP, but this effect may have been partly due to the influence of methylprednisolone. Cellular immunity was not influenced by LPD/CDDP infusion without low reduction of NK activity.

Carcinoma, Hepatocellular↗
PubMed1992

[Mitral valve replacement in a patient with hereditary hemorrhagic telangiectasia].

A 46-year-old female with mitral insufficiency complicated by hereditary hemorrhagic telangiectasia (Osler's disease) underwent successfully mitral valve replacement. The patient had a history of repeated large-volume nasal bleeding. Mitral valve replacement using a xenograft was safely performed with various attempts for preventing abnormal postoperative hemorrhage.

Bioprosthesis↗
PubMed1992

[Quantitative estimation of the relationship between amino acids and cataracts in rat lens].

The concentration of free amino acids and their related compounds has been determined in the lenses of ICR (f) strain rat and in the Wistar strain rat's lenses which were cultured with diethyl maleate. It was supposed that the decrease of cystathionine and the increase of serine in lenses of ICR with aging were related with development of senile cataracts. The increase of cystathionine in lenses cultured were suggested that synthesis of taurine is done by cystathionine pathway. Quantitative changes of amino acids were higher than normal of glutamine, glycine and aspartate in lenses cultured. It was supposed that the changes were the flow in lens from medium for synthesis of glutathione and glucose.

Amino Acids↗
PubMed1992

[Effects of dobutamine and isoproterenol on systemic hemodynamics and myocardial metabolism in children after open heart surgery].

The purpose of this study is to know the effects of Dobutamine (DOB) and Isoproterenol (ISP) on the systemic hemodynamics and myocardial metabolism in the acute phase after open heart surgery in children. Twelve patients with congenital heart disease were administered 5 and 10 micrograms/kg/min (gamma) of DOB, then 0.005 and 0.01 gamma of ISP, and the systemic hemodynamic and metabolic data were taken before and after the administration of the drugs. DOB: DOB increased HR and SVI, so CI rose up markedly. The systolic, diastolic and mean blood pressure also rose up after both doses. CVP and PCWP were depressed at both dosage levels. SVRI and PVRI did not show an appreciable change. ISP: ISP increased HR, CI and systolic blood pressures significantly. On the other hand, SVRI, PVRI and PCWP were decreased at both dosage levels. Myocardial metabolism: The two drugs tested did not exhibit any effect on the progress of anaerobic myocardial metabolism. The myocardial oxygen uptake rate was decreased with DOB and ISP. These phenomena probably suggest that DOB and ISP dilate the coronary vascular bed. From the above data, the following effects can be expected by the use of each drug after open heart surgery in children; 1) powerful inotropic and chronotropic action by DOB, and 2) chronotropic action and after-load reduction by ISP.

Anaerobiosis↗
PubMed1992

[The metabolism of sulfur containing amino acids in the rat lens].

To determine the metabolism of sulfur containing amino acids in cultured rat lenses, the author studied the uptake and incorporation of radioactive amino acids (3H-leucine, 14C-glycine, 14C-cystine and 35S-methionine) into whole and fractions of the lens, and the effects of diethyl maleate (DEM), the inhibitions of glutathione (GSH) synthesis on them. The uptake and incorporation of radioactive amino acids with the exception of cystine into whole and fractions of the lens were decreased, especially in DEM-additive group. In DEM group, the uptake of cystine into whole lens was suppressed but that in control group was not. The incorporation of cystine into protein fraction (WIS, WS) were increased in DEM group. It was supposed that the decrease in the incorporation of glycine and the increase in that of cystine into protein fractions were related to the formation of high molecular weight proteins. It was also assumed that the decrease of the uptake of cystine into TCA soluble fraction was due to the inhibition of the synthesis of GSH.

Amino Acids, Sulfur↗
PubMed1992

[Bicuspid aortic valve with sudden onset of aortic insufficiency due to rare causes: report of two cases].

This report describes two cases of aortic valve replacement which was warranted by the suddenly developed aortic regurgitation due to a congenitally bicuspid aortic valve. Aortic insufficiency was caused by the rupture of the strand which lifted a larger cusp to the aortic wall in one, and by the perforation of valvular aneurysm in another. Reviewing the literature these types of aortic insufficiency are rarely reported.

Acute Disease↗
PubMed1992

Papillary renal cell carcinoma. Report of two cases.

Papillary renal cell carcinoma is an uncommon variant of renal cell carcinoma which has unique features including hypovascularity or avascularity, extensive stromal macrophage infiltration and better prognosis than that for nonpapillary renal cell carcinoma. Two cases of papillary renal cell carcinoma presenting hypovascular or avascular angiology are presented. Histologically, the two tumors had a purely papillary structure. Papillae were lined by a layer of epithelial cells which lacked prominent cellular atypia, and there were numerous macrophages in the stroma. In addition, in one patient, extensive calcification of the tumor capsule was present. Furthermore, our experience in the present study with imprint cytology indicates that it offers corroborative information for the intraoperative diagnosis made on the basis of frozen section examination.

Adult↗
PubMed1991

Pulmonary blastoma with a topographic transition from blastic to more differentiated areas. An immunohistochemical assessment of its embryonic nature using stage-specific embryonic antigens.

In order to investigate the probable embryonic nature of pulmonary blastoma, immunohistochemical studies were performed using stage-specific embryonic antigens (Ley, Lex, sialyl Lex-i) in case of pulmonary blastoma with a very wide spectrum of morphological features. The tumour presented a topographic transition from primitive blastic and embryonic areas to more differentiated areas showing diverse differentiation. Blastic areas composed of extremely immature cells were found in most peripheral parts of the tumour. Inside the blastic areas there were "embryonic" areas which morphologically resembled human embryo lungs in the pseudoglandular and canalicular stages. Most central parts of the tumour showed more differentiated features including chondrosarcomatous, leiomyosarcomatous and rhabdomyosarcomatous elements and the common type of adenocarcinomatous element. Electron microscopic observation suggested the blastic and embryonic nature of these immature cell elements. Ley was expressed in the blastic and pseudoglandular areas. Lex was expressed in the canalicular areas. These antigens were not expressed in the more differentiated areas. The topographic gradient in the tumour of morphology and antigen expression from the peripheral blastic areas to the central more differentiated areas suggests that the primitive cells gradually differentiated into more mature cells of various directions as the tumour grew in size.

Antigens↗
PubMed1991

The natural history and timing of the radical operation for subpulmonic ventricular septal defects.

In order to further understand the natural history and timing of repair for subpulmonic (type I) ventricular septal defect (VSD), 70 patients who underwent radical surgery were reviewed. The patients with this type of VSD accounted for 30 per cent of a total 236 children with types I, II and III VSD who underwent repair between 1978 and 1989. The frequency of aortic regurgitation was 30 per cent, being higher in the group aged older than 10 years than in the younger group (p less than 0.05). The median ages of patients with normal, prolapsed and regurgitated valves were 5, 6.5, and 10 years, respectively, and each value exhibited significant differences (p less than 0.05). The left to right shunt ratio and systolic pulmonary artery pressure of the patients with normal valves were significantly higher than those of the patients with abnormal valves. The outcome of the patients with regurgitation varied according to Sellers grading with cases of grade two valvular deformities recovering well after the repair, while cases of grade three had deformities of grade one or two severity remaining. These results led us to establish the following strategy for patients with I-VSD: 1) a child should be regularly checked by USG; 2) a child noted as having a prolapsing valve is recommended to undergo repair by the age of 10 to 12 years; and 3) a child found to have regurgitation should undergo repair as soon as possible, unless the valve regurgitation does not become more severe than Sellers grade two.

Adolescent↗
PubMed1991

Expression of MHC class II antigens in human lung cancer cells.

Surgical specimens of lung cancers were examined immunopathologically for the expression of major histocompatibility complex class II (MHC-II) antigens in the tumor cells and their relationship to the lymphocytic infiltration. A lymphocytic infiltrate was frequently observed in the tumor tissue, though its intensity differed among the various histological types. MHC-II antigens were often demonstrated in tumors with a lymphocytic infiltrate. They were detected predominantly in the cytoplasm of tumor cells and to a lesser extent on the cell membranes. The emergence of the MHC-II-positive tumor cells was closely related to a local infiltration by lymphocytes including interferon-gamma (IFN-gamma)-producing T-cells. On the basis of the histological findings, an in vitro experiment was carried out. Four types of lung cancer cells were incubated with recombinant IFN-gamma in order to induce MHC-II antigens. MHC-II antigens (HLA-DR as well as HLA-DQ and HLA-DP antigens) were elicited in three cancer cell lines depending on the concentration of IFN-gamma. Immunoelectron microscopic study revealed that they were expressed on the surface of the cell membrane, though to a lesser extent than in the cytoplasm. It was considered that MHC-II antigens could be induced in some tumor cells in the immunological environment where IFN-gamma was secreted from T-cells and concentrated locally.

HLA-DQ Antigens↗
PubMed1991

A scanning electron microscopic study of the contraction of vascular wall cells in dog dental pulp.

Ultrastructural changes in vascular wall cells in dog dental pulp after removal of connective tissue components were studied by scanning electron microscopy following administration of norepinephrine (0.2 mg/kg). Contracted smooth-muscle cells were frequently seen in arterioles of all sizes. The surfaces of these cells were highly irregular with numerous evaginations and invaginations, varying considerably in configuration and size. Many evaginations ran longitudinally or obliquely to the long axis of the vessel. Some meandering evaginations were also observed as, rarely, were small spherical or bulbous projections. Spidery smooth-muscle cells frequently seen in the tunica media of terminal arterioles and thought to be primitive smooth-muscle cells exhibited fewer irregularities than the typical spindle-shaped smooth-muscle cells beneath them. Pericytes in the larger post-capillary venules (20 microns or larger in diameter) often showed evaginations and invaginations, mainly running parallel to the vessel axis. On the other hand, no surface irregularities could be seen in pericytes of either the smaller post-capillary venules (less than 20 microns in diameter) or the capillaries, although occasional evaginations running parallel to the vessel axis were noted on the outer surface of the endothelium.

Animals↗
PubMed1991

[Cholesterol, atherosclerosis and cerebro-cardiovascular complications in 3,236 elderly autopsy cases].

The effect of serum cholesterol on aortic, cerebral, coronary and femoral atherosclerosis as well as on the incidence of cerebral and myocardial infarctions were analyzed in 3,236 consecutive autopsies in the elderly. Serum cholesterol levels declined over the age of 80 in both genders. The cholesterol levels of females were significantly higher than that of males in each age group from the sixties through the nineties. The increase in serum cholesterol was correlated with the progression of coronary atherosclerosis in both genders, but not with cerebral or femoral atherosclerosis. Slight progression of aortic atherosclerosis was observed when serum cholesterol was over 160 mg/dl. Cholesterol induced progression of coronary atherosclerosis was found in cases with hypertension, but not in the normotensive group. In accordance with the progression of coronary atherosclerosis, the incidence of myocardial infarction increased with an elevation of serum cholesterol levels, and this relationship between myocardial infarction and cholesterol levels was found only in patients with hypertension. No correlation was found between the incidence of cerebral infarction and serum cholesterol levels. It was concluded that hypercholesterolemia in the elderly is a risk factor of myocardial infarction in cases with hypertension, but is not a risk factor of cerebral infarction.

Aged↗
PubMed1991

[Methicillin-cephem-resistant Staphylococcus aureus (MRSA) mediastinitis following open heart surgery].

Mediastinitis following cardiac surgery occurs frequently in association with high mortality and morbidity. Patient was a 6-year-old boy suffering from Sotos syndrome with secundum type of ASD. He was operated upon to repair ASD. Following the surgery, he suffered from MRSA mediastinitis and osteomyelitis of the sternum. Routine method of closed irrigation after reopening of the sternal wound was ineffective. Patient recovered following aggressive debridement repeatedly, open drainage and topical irrigation with vancomycin. This appears to be a useful method to treat MRSA mediastinitis of the sternum.

Cephalosporins↗
PubMed1991

[Effects of dopamine and dobutamine on systemic hemodynamics and myocardial metabolism in children after open heart surgery].

The purpose of this study is to know the effects of Dopamine (DOA) and Dobutamine (DOB) on the systemic hemodynamics and myocardial metabolism in the acute phase after open heart surgery in children. Thirty patients with congenital heart disease were divided into following two groups. The first 14 cases were administered 5 and 10 micrograms/kg/min (gamma) of DOA, and the systemic hemodynamic and metabolic data were taken before and after the administration of the drug. The second 12 cases were given the same doses of DOB instead of DOA. DOA: The blood pressure was elevated by 10 gamma of DOA, and cardiac index (CI) and stroke volume index (SVI) rose up at both doses of DOA. On the other hand, systemic vascular resistance (SVR) and left atrial pressure (LAP) were decreased at both dosage levels. DOB: At the same dose of DOA, DOB increased HR and SVI, so CI rose up markedly. The systolic and mean blood pressure also rose up at both doses. CVP and LAP were depressed at either dosage level. SVR did not show an appreciable change. Myocardial metabolism: The two drugs tested did not exhibit the progress of anaerobic myocardial metabolism. The myocardial oxygen uptake rate increased with DOA, but decreased with DOB. This phenomena probably suggests that DOB dilates coronary vascular bed. From the above data, the following effects are expected by the use of each drug after open heart surgery in children: 1) an increase of cardiac output due to inotropic action by DOA, 2) powerful inotropic and chronotropic action by DOB.

Child↗
PubMed1990

Variation in the pattern of [Ca2+]i change induced by acetylcholine in cultured hippocampal neurons.

Acetylcholine (ACh) caused various patterns of change in the intracellular Ca2+ concentration ([Ca2+]i) in cultured rat hippocampal neurons. We studied the underlying mechanisms of the [Ca2+]i changes with simultaneous recording of [Ca2+]i and membrane potential/current. In most cases, [Ca2+]i rise was accompanied by a membrane depolarization. The [Ca2+]i change was significantly reduced when the membrane was voltage clamped, which implies that most of the [Ca2+]i rise results from the Ca2+ influx through the voltage-gated Ca2+ channel activated by the membrane depolarization. The membrane depolarizations were classified into two types, one associated with membrane conductance decrease and the other associated with membrane conductance increase. The former results from potassium conductance ((gK+) decrease, and the latter may result from the activation of a Na(+)-permeable channel. However, [Ca2+]i elevation was also observed in some neurons showing membrane hyperpolarization in response to ACh. This seems to show that ACh liberates Ca2+ from the intracellular Ca2+ store, resulting in the activation of a calcium-dependent K+ channel (KCa). The variations of ACh response in the hippocampal neurons seem to result from a variety of muscarinic acetylcholine receptors and various species of ion channels governed by those receptors.

Acetylcholine↗