Search PubMed⌕ Search

Biomedical subjects

K Shibata

Publications and source records attributed to K Shibata.

At least 523 records · Page 29Linked to original sources
PubMed1990

[Renal function after aortic reconstruction for aortic dissection: special reference to the renal blood flow from false lumen].

Relationships between preoperative renal blood flow and postoperative renal dysfunction after aortic reconstruction for aortic dissection of DeBakey I and IIIb type were discussed. The incidence of renal dysfunction after surgery was not so high and renal failure was transient. Renal dysfunction occurred in the cases with true lumen oppressed by false lumen at chronic stage. Sometimes, abnormal findings were showed in CT scanning and/or renogram even in serum creatinine or BUN value was normal. In conclusion, our data showed justification of anastomosis of distal artificial graft to true lumen in acute stage. But in chronic stage, it is very important in point of selection of operative method to recognize how renal blood flow was preserved and to know the location and size of reentry before surgery.

Adolescent↗
PubMed1990

[Case report of the superior approach for correction of the supracardiac type of total anomalous pulmonary venous drainage (TAPVD) in the neonatal period].

An eleven-day-old newborn with cyanosis and respiratory distress was admitted. Intubation and catecholamine administration had already done. Blood pressure was 80/50 mmHg, heart rate was 160/min. Urine volume was only 7 ml per 4 hours with diuretics. The diagnosis of supracardiac type of TAPVD was done by echo cardiography. Without cardiac catheterization, emergent operation was performed. After median sternotomy, the mobilization of the aorta was done. Under cardiopulmonary bypass the aorta was retracted to the left, the superior vena cava to the right and the common pulmonary venous trunk (CPV) was identified through the transverse sinus. Parallel incision were made in the left atrium and CPV, and extended to the vertical vein. An anastomosis using continuous suture was fashioned. She had a good postoperative course. The superior approach through the transverse sinus affords excellent exposure of the CPV and left atrium in situ in the neonatal period, if the mobilization of the aorta is completed, and the heart is not compressed or displaced. This approach is useful for supracardiac type of TAPVD.

Female↗
PubMed1990

[An experimental study of reconstruction--differences of the healing process by materials].

The healing processes of carinal reconstruction by suture materials; absorbable suture (Vicryl) and nonabsorbable suture (Prolene) were compared. 67 adult mongrel dogs underwent resection of two rings of the trachea and bilateral main bronchi. This was followed by end-to-end anastomosis of the reconstructed carina and the remaining trachea. 3-0 Vicryl or 3-0 Prolene were used respectively. At some intervals, each anastomosis was removed and was analyzed by bronchoscopy, microangiography, scanning electron microscopy (SEM) and light microscopy. Suture insufficiency occurred in two of 32 anastomosis sutured by Vicryl and four of 35 anastomosis sutured by Prolene sutures. Stenosis developed in one of the Vicryl group and two of the Prolene group. Vicryl showed more inflammation than Prolene for 3 weeks after surgery. In four weeks, the inflammation subsided. Anastomoses were of the same degree in both groups. In microangiography, vascular regeneration was abundant by 3 weeks, which normalized in 4 weeks showing a normal network in both groups. Normalization of the vascular network appeared the earliest at the membranous portion. Scanning electron microscopy showed no difference in the reconstruction of the cilia over the anastomosis area in the both groups. This term was 2 months. The order of reconstruction revealed by SEM was the same as observed by microangiography. But in the Prolene group, it took more than 3 months for the suture material to be completely covered with the epithelium. In light microscopy, inflammation was stronger in the group than by in the Prolene groups, and it continued for 4 weeks suture material could not be found in the anastomosis area with bronchoscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Effect of deep inspiration on maximum expiratory flow (Vmax) depends on basal bronchomotor tone in young healthy females].

The relationship between the effect of deep inspiration on Vmax and basal bronchomotor tone was studied by partial and maximum expiratory flow-volume curve in 16 young healthy females (20-21 years old). Effect of deep inspiration on Vmax (DI index; (PEF25-MEF25)/PEF25) significantly related to percent increase in PEF25 not only by inhalation of ipratropium bromide (r = 0.81, p less than 0.0002) but also by inhalation of salbutamol (r = -0.62, p less than 0.01). Furthermore, day to day variation of DI index significantly related to day to day variation of PEF25 (r = 0.68, p less than 0.005) but not to that of MEF25. These findings suggest that the bronchodilating effect of deep inspiration in young healthy females may depend on intensity of basal bronchomotor tone caused by tonic vagal nerve activity.

Adult↗
PubMed1990

[Effects of surgical correction on pulmonary function in pectus excavatum cases].

Preoperative and postoperative pulmonary function were compared by spirometry in one hundred and eleven cases, from 1980 to 1989, with pectus excavatum deformity. The patients consisted of 85 males and 26 females, aged 5-41 years. In the preoperative examination, mean values for % vital capacity (%VC), % 1 sec. timed vital capacity (FEV1.0%), % residual volume (%RV), % maximal voluntary ventilation (%MVV) were within normal limits. %VC had a tendency to decrease with increase in the degree of depression of the anterior chest wall. Postoperatively, %VC was significantly dropped, although no significant change was seen in FEV1.0%, %RV and %MVV. Seven of 10 cases with low %VC and four of 6 cases with low %VC and %RV preoperatively demonstrated improvement in %VC and %RV after sternal elevation surgery.

Adolescent↗
PubMed1990

[Anesthetic management for resection of cardiac pheochromocytoma].

Cardiac pheochromocytoma is a rare disease, and there have been few reports concerning anesthetic management for the resection. This is a report of a 46-year-old man with cardiac pheochromocytoma with the perioperative changes in plasma catecholamine concentrations. Anesthesia was maintained with enflurane (0.5-2.0%) and 50% nitrous oxide in oxygen. Additional fentanyl (900 micrograms) was given as required. Intravenous administration of nitroglycerin in a dose of 5-20 micrograms.kg-1.min-1 was effective for prevention of intraoperative hypertension. After cardiopulmonary bypass and cardioplegic arrest were instituted, the manipulation of the tumor had no effect upon the blood pressure. A serious increase in plasma norepinephrine concentration occurred during both bicaval cannulation and manipulation of the tumor. Although the anesthetic management for resection of adrenal pheochromocytoma has been well-documented, that of cardiac pheochromocytoma requires following specific considerations. 1) Serious hypertension and arrhythmias may occur during manipulation of the heart. 2) It is possible to dissect the tumor safely after isolation of the heart from systemic circulation. It is of great interest that the blood pressure remained almost unchanged during cardiopulmonary bypass despite a marked increase in catecholamine concentrations. 3) Operative mortality rate is high.

Anesthesia, Inhalation↗
PubMed1990

[A case of coronary sinus rupture following retrograde coronary perfusion for myocardial protection].

A 48-year-old woman was admitted to our hospital suffering from chest and back pain. The aortogram and CT scanning revealed aortic dissection (DeBakey II type). Six days after onset, the emergent operation was carried out under the cardio-pulmonary bypass. Myocardial protection was made by retrograde coronary sinus perfusion (RCSP) with cold GIK. The ascending aorta was replaced with an artificial graft including the entry. Massive bleeding in the pericardial space and the rupture of coronary sinus was recognized immediately after declamping of the aorta. Repair was made successfully under induced electric ventricular fibrillation. Care for RCSP was discussed.

Coronary Vessels↗
PubMed1989

Thymomas associated with pure red cell aplasia. Histologic and follow-up studies.

Seventeen cases of pure red cell aplasia (PRCA) with thymoma were studied clinically, histologically, and immunologically. Two cases were associated with myasthenia gravis (MG), and three with hypogammaglobulinemia. Coombs test and antinucleus antibody test were positive in five cases. All thymomas were spindle cell types, and the adjacent thymuses had no germinal center, but showed epithelial clusters frequently. All patients, except one whose tumor was unresectable, had thymo-thymomectomy. The operation was effective in six cases (37.5%), and the effects were not different between two operative procedures (simple and extended thymectomy). Myasthenic symptoms in two patients remitted after the operation, but effects on hypogammaglobulinemia were conincident with those on PRCA.

Agammaglobulinemia↗
PubMed1989

Neuroanatomical substrates regulating rat conflict behavior evidenced by brain lesioning.

The present study was designed to clarify neural circuits involved in the mediation of behavioral suppression using the Vogel type conflict procedure in rats. Among the brain nuclei inclusive of neuroanatomical substrates of behavioral suppression, lesioning of the central amygdala, mammillary body or frontal cortex led to a significant increase in the punished drinking responses. Lesion of the septum also tended to increase these responses. These results show the key role of these brain areas in mediation of behavioral suppression such as conflict behavior.

Amygdala↗
PubMed1989

Promotion of calcification by imidazole and its suppression by diltiazem in the growth cartilage of rats with HEBP induced rickets.

The object of our experiments was to determine the effect of imidazole on the growth cartilage of rats with HEBP induced rickets. When HEBP (1-hydroxyethylidene-1, 1-bisphophonic acid) was given to young rats in large doses over a short period, rickets was consistently produced. We found that imidazole had a calcification promoting action in the growth plate cartilage where there had been an increase in thickness due to the inhibition of calcification. In an attempt to clarify the mechanism of accelerated calcification due to imidazole, the effects of diltiazem, a calcium antagonist, were observed; it was found to suppress the accelerated calcification. If diltiazem inhibits the entry of calcium ions into the cells of the growth cartilage, as it does in smooth muscle and myocardial cells, then our results indicate that intracellular concentrations of calcium may play an important role in the accelerated calcification due to imidazole.

Animals↗
PubMed1989

The immunocytochemical localization of superoxide dismutase in the enterocytes of the avian intestine: the effect of vitamin D3.

Both light microscopical and electron microscopical immunocytochemical techniques were utilized to localize CuZn-superoxide dismutase (SOD) in the duodenum of normal, rachitic and vitamin-D3-replete chicks. This enzyme catalyses the dismutation of the superoxide anion, a toxic free radical generated during the normal aerobic metabolism of most respiring cells. Light microscopy showed no SOD activity associated with the duodenal enterocytes of normal and rachitic chicks. However, in rachitic animals subsequently treated with vitamin D, i.e. vitamin-D-replete chicks, intense immunoreactivity for the enzyme was seen in association with the apical border of the duodenal absorptive cells. Immunostaining for SOD was not seen in goblet cells. With electron microscopy, immunostaining for SOD activity was identified in association with the apical microvilli and, to a lesser degree, with the terminal web, a well as in association with both lysosomes and peroxisomes. From this report it appears that there is a physiological relationship between vitamin D, SOD and the intestinal absorptive cell. However, the precise relationship must await further clarification.

Animals↗
PubMed1989

The ultrastructural immunocytochemical localization of superoxide dismutase in the amphibian urinary bladder: effect of aldosterone.

Transmission electron microscopy and immunohistochemistry, the latter employing the avidin-biotin-peroxidase (ABC complex) technique, were utilized to localize copper-zinc superoxide dismutase (CuZn-SOD) enzyme activity in the epithelial cells of the toad urinary bladder mucosa. This 'scavenger' enzyme catalyses the dismutation (reduction-oxidation) of the superoxide anion (O2-), a toxic free radical generated during normal cellular respiration. In unstimulated epithelial cells, enzyme activity was seen in the cytosol of granular, mitochondrial-rich and goblet cells. The basal cells were generally devoid of enzyme activity. In addition to the cytosol, SOD activity was also seen in association with the apical plasma membrane of the epithelial cells. In the presence of the steroid hormone aldosterone (10(-7)M, 30 min-6h), CuZn-SOD activity was markedly increased along the luminal mucosal membrane of granular, mitochondrial-rich and goblet cells. This increase was seen as early as 30 min after the addition of hormone, and as long as 6h after treatment. The cytosolic reaction was usually decreased or absent under these conditions. From the data presented, it appears that CuZn-SOD is involved in electrolyte (sodium) transport in the epithelial cells of the toad urinary bladder. The latter may involve hormone-induced alterations in luminal cell membrane structure and chemistry.

Aldosterone↗
PubMed1989

The immunohistochemical localization of superoxide dismutase activity in the avian epithelial growth plate.

Superoxide dismutase (SOD) is a 'scavenger' enzyme which catalyses the dismutation (reduction-oxidation) of the superoxide anion (O2-.), a toxic free radical generated during normal cellular respiration. Light microscopy employing immunohistochemistry was utilized for localizing SOD activity in the chick epiphyseal cartilage. Antibodies to mammalian liver CuZn-SOD were prepared and the avidin-biotin-peroxidase technique (ABC complex) was utilized to localize activity for this enzyme in the growth plate cartilage. The localization of enzyme activity varied in accordance with the characteristic zonation pattern of the growth plate (zone of proliferation, zone of maturation, zone of cell hypertrophy and zone of matrix calcification). In the upper regions of the epiphyseal cartilage (the zones of proliferation and maturation), where the vascularity is poor and the oxygen tension low, SOD activity was localized within the chondrocytes. No extracellular activity was observed. However, in the lower regions of the growth plate (the zones of cell hypertrophy and matrix calcification), where both the vascularity and the oxygen tensions are increased, SOD activity was intense in both the chondrocytes and the surrounding extracellular matrix. Thus, the distribution of SOD enzyme activity in this tissue seems to vary in accordance with the level of oxygen present. The significance of the extracellular SOD activity, seen in the lower aspects of the growth plate cartilage, may indicate the sensitivity of matrix components, especially collagen, to toxic free radicals such as the superoxide anion.

Animals↗
PubMed1989

The effects of pulsatile and non-pulsatile cardiopulmonary bypass on renal blood flow and function.

The physiologic effects of pulsatile and non-pulsatile flow in cardiopulmonary bypass were compared in terms of the relationship between different flow rates and what effects these had on pulsatile and non-pulsatile flow. Forty adult mongrel dogs were used in this study and divided into 5 groups, each comprised of 8 animals, according to the flow rate during cardiopulmonary bypass, namely; 40, 60, 80, 100, or 120 ml/kg/min. The animals were perfused with either pulsatile or non-pulsatile flow for 1 hour, given randomly at the same mean flow rate. At flow rates of 80 and 100 ml/kg/min, the mean arterial blood pressure and total peripheral vascular resistance were significantly lower in pulsatile flow than in non-pulsatile flow, and the renal blood flow was significantly greater in pulsatile flow than in non-pulsatile flow. The renal arterial-venous lactate difference was significantly less in pulsatile flow than in non-pulsatile flow at a flow rate of 80 ml/kg/min, and the renal lactate extraction was significantly higher in pulsatile flow than in non-pulsatile flow at the same flow rate. The renal excess lactate was significantly lower in pulsatile flow than in non-pulsatile flow at a flow rate of 100 ml/kg/min. There were no significant differences in these parameters between the two types of perfusion at flow rates of 40, 60 or 120 ml/kg/min. Pulsatile flow was therefore apparently advantageous, when compared to non-pulsatile flow, in terms of hemodynamics, renal circulation, and metabolism of the kidney at flow rates of 80 and 100 ml/kg/min. However, when the flow rate was 120 ml/kg/min, pulsatile flow and non-pulsatile flow had the same effects.

Animals↗
PubMed1989

Inactivation of the vascular permeability-increasing activity of bradykinin by mycoplasmas.

Mycoplasma pneumoniae, M. genitalium, M. fermentans, M. hominis, M. salivarium, M. orale, Ureaplasma urealyticum and Acholeplasma laidlawii inactivated the vascular permeability-increasing activity of bradykinin when the mixture of bradykinin and mycoplasma cells was injected after incubation at 37 degrees C for 1 h. Cell components responsible for inactivation of the activity of bradykinin were found to be arginine-specific aminopeptidase and carboxypeptidase.

Acholeplasma laidlawii↗
PubMed1989

Correlation between niacin equivalent intake and urinary excretion of its metabolites, N'-methylnicotinamide, N'-methyl-2-pyridone-5-carboxamide, and N'-methyl-4-pyridone-3-carboxamide, in humans consuming a self-selected food.

N'-methyl-4-pyridone-3-carboxamide (4-py) is the major metabolite of nicotinamide and nicotinic acid in rats. However, because it is complicated to determine 4-py in humans, there is only one report on its excretion. Recently we developed a method for the microdetermination of 4-py by high-performance liquid chromatography. Urinary excretion of 4-py in Japanese students from Teikoku Women's University who consumed self-selected foods was 7.12 +/- 3.25 mumol/d, which is about one-fourth of N'-methylnicotinamide (MNA) and about one-ninth of N'-methyl-2-pyridone-5-carboxamide (2-py) excretion. The correlation coefficient between daily niacin equivalent (NE) intake and daily 4-py excretion was 0.529, which was about the same as the correlation coefficient between daily NE intake and daily 2-py excretion and which was two times higher than the correlation coefficient between daily NE intake and daily MNA excretion.

Adult↗
PubMed1989

Fate of excess nicotinamide and nicotinic acid differs in rats.

Rats administered excess nicotinamide and nicotinic acid were studied to determine the metabolic fate of pharmacological levels of these compounds. When a large amount of nicotinamide (500 mg/kg body wt) was intraperitoneally injected into rats, 32% of the dose was excreted as nicotinamide, 11% as N1-methylnicotinamide (MNA), 10% as nicotinuric acid, 5% as nicotinic acid, 3% as N1-methyl-4-pyridone-3-carboxamide (4-pyr) and 2% as N1-methyl-2-pyridone-5-carboxamide (2-pyr) during d 1 after the injection. Urinary excretion of these compounds gradually decreased with time and returned to normal by d 3. Urinary excretion of nicotinic acid and nicotinuric acid was observed only on d 1. When a large amount of nicotinic acid (500 mg/kg body wt) was intraperitoneally injected into rats, 55% of the dose was excreted as nicotinic acid and 15% as nicotinuric acid during d 1, and no excretion of these compounds was observed thereafter. The increase in excretion of nicotinamide, MNA, 2-pyr and 4-pyr was slight even on d 1. Excretion of nicotinic acid, nicotinuric acid, nicotinamide, MNA, 2-pyr and 4-pyr returned to normal levels on d 2. From these results, the different fates of excess nicotinamide and nicotinic acid are discussed.

Animals↗