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Biomedical subjects

A Hashimoto

Publications and source records attributed to A Hashimoto.

At least 181 records · Page 10Linked to original sources
PubMed1996

[Cerebral oxygen desaturation during rewarming in retrograde cerebral perfusion with total circulatory arrest].

To evaluate cerebral oxygen desaturation during retrograde cerebral perfusion with total circulatory arrest (RCP), we measured cerebral oxygen extraction (O2 Ext), and arterio-venous oxygen differences (AV DO2) during and after RCP and compared the results with usual cardiopulmonary bypass (CPB) using continuous jugular blood saturation (SjO2) monitoring. In the RCP group, 7 patients underwent aortic arch replacement with RCP and in the CPB group, 4 patients underwent valvular surgery with CPB. A 5.5 Fr oximetric catheter was placed in the jugular bulb and cerebral venous and radial arterial blood were sampled. Oxygen partial pressure and saturation were measured at six intervals from cerebral venous and radial arterial blood. Measurements were taken at the following phases: phase I: before ECC was established, phase II: immediately after ECC started; phase III: at hypothermia (18 degrees C in the RCP group and 28 degrees C in the CPB group), phase IV: during rewarming (30 degrees C), phase V: after rewarming (36 degrees C), phase IV: immediately after weaning from ECC. All 11 patients survived without neurological complications. The minimum SjO2 of continuous monitoring during rewarming in the RCP group was significantly lower than in the CPB group. AVDO2 in the RCP group was also significantly higher than in the CPB group during rewarming. O2 Ext in the RCP group was significantly higher than in the CPB group during and after rewarming. Differences in glucose utilization during and after rewarming were also detected. Moreover, to determine factors that influence SjO2 during and after rewarming, we evaluated correlations with arterial PaCO2, arterial pH, and rewarming duration. There were significant (p < 0.05) correlations between SjO2 and PaCO2 in phase IV and phase V, between SjO2 and pH, and between SjO2 and rewarming duration. In conclusion, continuous SjO2 measurements reflected cerebral oxygen desaturation during and after rewarming in RCP. In RCP, significantly greater desaturation during and after rewarming was detected than in CPB. Therefore we suggest that relatively slow rewarming, higher PaCO2, and more acidic pH strategies were advantageous for preventing desaturation during and after rewarming in RCP.

Adult↗
PubMed1996

[A case report on graft replacement of ruptured aneurysm of the arch and the descending thoracic aorta associated with dense pulmonary adhesion].

A 73-year-old patient had been followed for aortic arch aneurysm of 54 mm in diameter. He was hospitalized complaining of chest and back pain. A chest CT scan showed ruptured aortic arch aneurysm extending to mid-descending thoracic aorta, and an emergent operation was decided. The trachea was intubated with a univent tube providing a movable blocker (System Corporation) which was directed to the left bronchus for differential lung ventilation. The descending thoracic aorta was exposed through the left 4th intercostal thoracotomy just at the site intending to anastomose a prosthetic graft because of dense pulmonary adhesion. The ascending and arch aorta was approached via median sternotomy. Under deep hypothermia and retrograde cerebral perfusion, total arch and descending aortic replacement was performed using an arch graft providing four branch grafts for neck vessels reconstruction and pump perfusion. The patient showed moderate pulmonary bleeding during and after cardiopulmonary bypass, but improved gradually. He was weaned from the respirator on the 13th post-operative day. During extensive thoracic aortic surgery using left thoracotomy combined with median sternotomy, left lung deflation using a univent tracheal tube with a blocker, and circulatory arrest during distal aortic anastomosis, are useful in preventing lethal pulmonary bleeding caused by lung injury under the fully heparinized condition. However, in cases associated with dense pulmonary adhesion, it is important to dissect carefully just a small area necessary to anastomose a graft, and to take elaborate assistant measures.

Aged↗
PubMed1996

[Clinical evaluation of sulbactam/cefoperazone for lower respiratory tract infections. Correlation between the efficacy of sulbactam/cefoperazone and beta-lactamase].

The efficacy and safety of sulbactam/cefoperazone (SBT/CPZ) were evaluated in 42 patients with respiratory tract infections, including pneumonia (29 patients) and lower respiratory tract infections (5 patients). Overall clinical efficacy rates (excellent + good) were 79% in pneumonia and 80% in respiratory tract infections in 34 patients evaluated for clinical efficacy. It was excellent that the clinical efficacy rate was 92% in mild and moderate pneumonia. Pathogens isolated from sputa were 31 strains, including 8 strains of Pseudomonas aeruginosa, 7 of Streptococcus pneumoniae, 3 of Staphylococcus aureus and 3 of Haemophilus influenzae. Since the isolates were eradicated in 18 strains, replaced in 3, unchanged in 2 and unknown in 8, the overall eradication rate was 91%. The eradication rates were 89% in beta-lactamase producing strains and 100% in beta-lactamase positive sputum, and excellent or good in 19 (83%) of 23 patients with beta-lactamase negative sputum. The eradication rate was 88% in 5 patients with beta-lactamase positive sputum. One patient experienced a moderate rash. Abnormal laboratory test values were observed in 10 patients (26.3%), but these abnormalities were mild and transient. These results suggested that SBT/CPZ was effective and safe for the treatment of respiratory tract infections caused by beta-lactamase producing as well as beta-lactamase non-producing bacteria.

Aged↗
PubMed1996

Augmentation of parasympathetic nerve function in patients with extrinsic bronchial asthma--evaluation by coefficiency of variance of R-R interval with modified long-term ECG monitoring system.

Patients with bronchial asthma (BA) have evidence of increased vagal cholinergic tone. Although the cardiovascular-respiratory tests used in the past might have been biased by concomitant chest disease, coefficiencies of variance of the R wave to R wave (RR) interval (CVR-R) on electrocardiogram (ECG) have been applied to many diseases as a method of functional evaluation of the parasympathetic nerve system. In 24 hour recordings of ECG (Holter ECG), continuous values of CVR-R have been determined for each one-minute period with a recently developed long-term ECG monitoring system. To examine functional augmentation of parasympathetic nerve in patients with BA, we applied this system in the present study to determine the alteration of parasympathetic nerve function during an inhaled methacholine provocation test in 14 patients and 7 healthy subjects. CVR-R values were calculated from the collection of a 24-hour electrocardiogram. Bronchial response, which was measured by methacholine inhalation, was evaluated with the baseline value of respiratory resistance (Rrs-cont), the cumulative dose producing a 35% decrease in respiratory conductance (PD35Grs) and the minimum cumulative dose required to start to decrease respiratory conductance from baseline (Dmin). The serum concentrations of epinephrine and norepinephrine were measured at the basal and double-increased levels of respiratory resistance during the inhalation test. The increased values of CV(R-R) in asthmatic patients were intimately associated with augmented respiratory resistance. The disparity of CV(R-R) values (delta CV) during the resistance levels from basal to double in the asthmatic group was significantly greater than that in the control group. The absolute change of CV(R-R) values in the asthmatic group was significantly larger than that in the control group. There was a significant correlation between delta CV and Dmin (r = 0.536, p < 0.05), and between delta CV and PD35Grs (r = 0.552, p < 0.05). The serum concentrations of epinephrine and norepinephrine were not significantly different during the methacholine inhalation provocation test. We conclude that alteration of the values of CV(R-R), which were calculated with a modified long-term ECG recording system, may reflect the change of parasympathetic nerve function and the severity of bronchial hyperreactivity, and this system can be a useful non-invasive method for evaluation of increased vagal tone in patients with bronchial asthma.

Adult↗
PubMed1995

Anatomical distribution and postnatal changes in endogenous free D-aspartate and D-serine in rat brain and periphery.

We have investigated the anatomical distribution and postnatal development of D-aspartate and D-serine in the rat brain and periphery using HPLC techniques. D-Serine was confined predominantly to the brain throughout postnatal life. At birth, a substantial quantity of D-serine was observed throughout the brain areas. The cerebral D-serine content increased from birth to postnatal week (PW) 3 and remained constant thereafter, whereas the cerebellar D-serine content peaked at PW1. In contrast, the transient emergence of D-aspartate was found in almost all brain and peripheral organs. A substantial quantity of D-aspartate was also seen in all brain areas at birth, whereas the D-aspartate content in the cerebrum and cerebellum decreased dramatically by PW1 and 7 respectively. Further, the D-aspartate content and the ratio of D-aspartate to total aspartate were highest in the adrenal at PW3 (608 +/- 70 nmol/g, 45.9%) and in the testis at PW14 (221 +/- 7 nmol/g, 57.8%) respectively. Because D-serine potentiates N-methyl-D-aspartate receptor-mediated transmission through the strychnine-insensitive glycine site and because D-serine exhibits an N-methyl-D-aspartate receptor-related distribution and development, D-serine may be a tenable candidate for an intrinsic ligand for the glycine site. In contrast, because the periods of maximal emergence of D-aspartate in the brain and periphery occur during critical periods of morphological and functional maturation of organs, D-aspartate could participate in the regulation of these developmental processes of organs.

Age Factors↗
PubMed1995

Free D-serine in post-mortem brains and spinal cords of individuals with and without neuropsychiatric diseases.

We have measured the concentrations of free D-serine post-mortem in the prefrontal cortex, parietal cortex, cerebellum and spinal cord from individuals with and without (controls) neuropsychiatric diseases using high-performance liquid chromatography with fluorometric detection. The levels of D-serine were found to be high in the prefrontal and parietal cortex (around 100 nmol/g wet weight) and very low in the cerebellum and spinal cord (below 10 nmol/g wet weight). The uneven distribution of the D-amino acid in the human central nervous system (CNS) resembles that observed in rodents, suggesting that, as shown in the rat CNS, the regional variation of D-serine content in the human brain might also be closely correlated with those of the N-methyl-D-aspartate (NMDA) type excitatory amino acid receptor. In the prefrontal cortex, the gray and white matter had a similar concentration of D-serine. These findings, together with the selective action of D-serine at the NMDA-related glycine site and the non-neurogenic nature of extracellular D-serine release, add further support to the view that D-serine could be an intrinsic modulator of the NMDA receptor liberated from certain glial cells in the mammalian brain. Despite the anti-psychotogen activity of D-serine in the rat, there were no statistically significant differences between the D-serine contents in the prefrontal or parietal cortex of controls and those of patients with schizophrenia or dementia of the Alzheimer type.

Aging↗
PubMed1995

Detection of (1-3)-beta-D-glucan in a rat model of aspergillosis.

The G test containing factor G, fractioned from the Limulus lysate, was used to detect (1-3)-beta-D-glucan in a rat model of aspergillosis. Aspergillus fumigatus strain MF-13, 1 x 10(4) conidia, were inoculated transtracheally into rats treated with cortisone acetate (100 mg/kg) and fed a low-protein (8%) diet. Increased serum (1-3)-beta-D-glucan was found on the sixth day after inoculation in concentrations of 370 +/- 178 pg/ml (mean +/- SD) in untreated controls, and 154 +/- 43 pg/ml in rats treated with 0.5 mg/kg of amphotericin B. On day 11 (1-3)-beta-D-glucan concentrations were 2,590 +/- 2,940 pg/ml and 448 +/- 442 pg/ml, respectively. The elevation in levels of (1-3)-beta-D-glucan increased in correlation with the elevation of galactomannan antigen titers; (1-3)-beta-D-glucan is thus measurable during experimental aspergillosis in rats.

Amphotericin B↗
PubMed1995

Long-term results of aortic valve translocation for mycotic periannular abscess: comparative study of Danielson's original method and our threadless method.

Between June, 1983, and October, 1992, we performed Danielson's original translocation method in four patients (group I) and our translocation method in seven patients (group II), for the treatment of active periannular abscess. There were no perioperative or hospital deaths in either group. The long-term results of these two groups are compared in this report. There were four late deaths (mortality rate 100%) in group I, and three late deaths (mortality rate 43%) in group II. The causes of death were cardiac in six patients and noncardiac in one patient. Vein graft failure occurred in one group I patient (25%) and in two group II patients (28%). Rupture or aortic pseudoaneurysm formation occurred in three group I patients (75%). These findings suggest that our threadless method may be superior to Danielson's original translocation method. Therefore, with close observation, especially of saphenons vein great (SVG) failure, arterial graft use could be acceptable for translocation.

Abscess↗
PubMed1995

Operation for type A aortic dissection: introduction of retrograde cerebral perfusion.

Circulatory support during operation for type A aortic dissection is controversial among many medical centers. In the last 21 years, 100 patients with type A aortic dissection underwent 102 operations including 2 reoperations, and 29 patients showed Marfan's syndrome. During operation, no cerebral perfusion technique was used through February 1985 (period I), antegrade cerebral perfusion was applied since March 1985 (period II), and retrograde cerebral perfusion was introduced in November 1990 (period III). Surgical results were compared among these subgroups. Operative mortality was 12.1% in 33 chronic and 57.1% in 7 acute patients in period I, 11.1% in 27 chronic and 54.5% in 11 acute patients in period II, and 6.7% in 15 chronic and 0% in 9 acute patients in period III (period II versus III; p = 0.04). Retrograde cerebral perfusion decreased permanent brain complications. The 5-year actuarial survival was 59.7% in period I and 63.2% in period II (not significant), and the 3-year survival of period III was 91.7%. Actuarial survival of period III was significantly higher than those of periods I and II (p < 0.05). Surgical repair of aortic arch with cerebral perfusion techniques reduced the residual aneurysms. These results show that surgical results of type A aortic dissection in this series improved with the introduction of retrograde cerebral perfusion and extended surgical procedures.

Adult↗
PubMed1995

Operation for type B aortic dissection: introduction of left heart bypass.

Various support techniques for surgical treatment of type B aortic dissection have been used and recommended in many medical centers. In the last 21 years, 55 patients with type B aortic dissection underwent 65 operations including 10 reoperations, and 10 cases showed Marfan's syndrome. As circulatory support during operation, venoarterial bypass mainly was used until March 1987 (period I) and low-dose heparinized left heart bypass was applied since April 1987 (period II). Surgical results were compared among subgroups by the Kaplan-Meier actuarial method and Cox-Mantel statistical analysis. After the operation, early mortality was 27.3% in 33 patients in period I and 9.4% in 32 patients in period II (p = 0.06). The incidence of fatal hemorrhagic complications was decreased significantly by using the left heart bypass technique (p < 0.02). The 5-year actuarial survival of type B dissection was 60.6% in period I and 79.2% in period II (p = 0.07). These results suggest that surgical results of type B aortic dissection in this series might be improved with the introduction of left heart bypass and extended surgical procedures.

Adult↗
PubMed1995

Extracellular concentration of endogenous free D-serine in the rat brain as revealed by in vivo microdialysis.

Using an in vivo microdialysis technique, we have measured the extracellular concentration of endogenous free D-serine in comparison with that of L-serine, glycine and L-glutamate in the discrete brain areas of the freely moving rat. A high concentration of D-serine was observed in the dialysate obtained from the medial prefrontal cortex and striatum, whereas the cerebellar dialysate contained only a trace amount of the D-amino acid. The regional variation in the basal overflow of D-serine was proportional to that of its tissue levels which has been shown to closely correlate with the distribution of the N-methyl-D-aspartate type excitatory amino acid receptor. In contrast, the extracellular release of glycine and L-glutamate was higher in the cerebellum and very low in the striatum. The extracellular concentrations of L-serine were more than three times those of striatal D-serine in the three regions. Neither addition of a sodium channel blocker, tetrodotoxin (2 microM), nor deprivation of Ca2+ from the perfusate reduced the basal extracellular levels of the four amino acids tested in the medial prefrontal cortex. Furthermore, intra-frontal cortex perfusion of a sodium channel activator, veratrine (200 micrograms/ml), caused an increase in the extracellular release of glycine and L-glutamate but a slight decrease in that of D-serine in a tetrodotoxin-sensitive manner in the cortical region.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1995

Left ventricular function on exercise after surgical treatment of small aortic annuli.

To evaluate left ventricular function during exercise after aortic annular enlargement 15 patients with either aortic (group I, n = 8) or aortomitral (group II, n = 7) annuloplasty for small aortic annuli and eight patients (group III) with standard valve replacement for aortic stenosis without small aortic annuli received gated cardiac pool imagining by technetium-99m-labelled red blood cells at rest and during exercise at a mean of 23 months after operation. Left ventricular ejection fraction, preload requitable stroke work and stroke power index (preload requitable stroke work/systolic ejection period) were measured. Compared with resting values, left ventricular performance and stroke work rate on exercise after aortic annular enlargements increased significantly, as did those after standard aortic valve replacement. These results suggest that aortic annular enlargement can be indicated for surgical treatment of valvular heart diseases associated with small aortic annuli.

Adult↗
PubMed1995

Medium-term results after surgery for aortic arch aneurysm with hypothermic cerebral perfusion.

We have used two techniques of hypothermic cerebral perfusion (CP) for the surgical treatment of aortic arch aneurysm in the last 10 years. Between March 1985 and December 1993, 83 patients underwent surgery for aortic arch aneurysm. Fifty-one cases had aortic dissection (AD) in the transverse arch and/or its branches, and 32 cases showed true aneurysm (TA) of the aortic arch. In those 83 patients, 37 cases received antegrade CP and 46 cases underwent retrograde CP. Surgical results were compared among the groups by Kaplan-Meier actuarial method and Cox-Mantel statistical analysis. The early mortality after surgery for aortic arch aneurysm was 11.8% in the AD group and 21.9% in the TA group. The early mortality was 21.6% with antegrade CP and 10.9% with retrograde CP. The 6-year actuarial survival rate was 71.7% in the TA group and 67.1% in the AD group. In the AD group, the 3-year survival rate was 93.9% with retrograde CP and 61.1% with antegrade CP (P < 0.005). In the TA group, the 3-year survival rate was similar for antegrade CP (73.3%) and retrograde CP (69.2%). These results suggest that current surgical results of aortic arch aneurysm with hypothermic CP are acceptable and the retrograde CP technique might be recommended, especially for surgery of aortic arch aneurysm with AD.

Actuarial Analysis↗
PubMed1995

Functional comparison of D-serine and glycine in rodents: the effect on cloned NMDA receptors and the extracellular concentration.

We compared the activity of free D-Ser on the potentiation of cloned NMDA receptors with that of Gly by using a Xenopus oocyte expression system. The extracellular concentration of free D-Ser and Gly was further studied by means of microdialysis. The ED50 values of D-Ser were three to four times lower than those of Gly in any combination of epsilon 1, epsilon 2, epsilon 3, or epsilon 4 and zeta 1. Site-directed mutagenesis of zeta 1 subunits revealed that some aromatic residues necessary for the action of Gly affected the ED50 value of D-Ser. This result showed that the residues play crucial roles in the action of D-Ser. In vivo microdialysis of rodent brain revealed that the extracellular concentration of free D-Ser in the frontal cortex (6.5 microM) was high enough to saturate the Gly site on the NMDA receptor, but that in the cerebellum was not. These findings suggest that D-Ser is a candidate of the endogenous potentiator of the NMDA receptor in the rodent frontal cortex.

Animals↗
PubMed1995

Current strategy for severe heart failure with mechanical circulatory support.

In the last 10 years, 37 patients received assisted circulation or a ventricular assist device after open-heart operations at the Heart Institute of Japan. After cardiovascular surgery, 12 patients underwent venoarterial bypass (VAB), 13 had biventricular bypass (BVB), 8 had left ventricular bypass (LVB), and the remaining 4 received a left ventricular assist device (LVAD). Weaning and discharge rates of the patients by type of circulatory supports were 41.7 and 25.0% with VAB, 69.3 and 46.2% with BVB, 87.5 and 37.5% with LVB, 75.0 and 50.0% with LVAD, and 44.4 and 11.1% with PCPS, respectively. Concerning complications of postcardiotomy circulatory support, hemorrhage and ventricular arrhythmia postcardiotomy circulatory support, hemorrhage, and ventricular arrhythmia (immature weaning) decreased with low-heparinized isolated left ventricular supports (i.e., LVB, LVAD). However, profound biventricular failure, infection, and multiple organ failure remain as possible complications with any type of assisted circulation. These results suggest that early application of circulatory support and appropriate selection of the mode of support and devices used are important for successful circulatory support.

Adult↗
PubMed1995

Retrograde cerebral perfusion with hypothermic blood provides efficient protection of the brain: a neuropathological study.

Retrograde cerebral perfusion is a method that is recently being used for protection of the brain during operations on the aortic arch. This method is useful but is said to provide a limited time for protecting the brain. We designed an experiment in dogs to investigate neuropathologically the effect of protecting the brain for 120 minutes under: (1) circulatory arrest (CA); (2) retrograde cerebral perfusion with moderately cooled blood (RCPMC); and (3) retrograde cerebral perfusion with deeply cooled blood (RCPDC). We calculated the number of the abnormal cells of 400 hippocampal neurons per dog light microscopically. The number was 199 +/- 23 (mean +/- 1 SD) in the CA group, 149 +/- 50 in the RCPMC group, and 72 +/- 33 in the RCPDC group. The difference between the CA group and the RCPMC group was not statistically significant (p < 0.05), but there was a significant difference between the RCPMC and RCPDC groups (p < 0.05). The degree of cerebral protection provided by retrograde cerebral perfusion for 120 minutes is not sufficient when using moderately cooled blood. If we use deeply cooled blood at a temperature of about 10 degrees C, we should obtain a sufficient degree of protection of the brain.

Animals↗
PubMed1995

[Microbiological and clinical study of fungemia between 1981 and 1992].

Fungi were isolated from 113 (14.2%) of 789 patients with positive blood cultures at Oita Medical University Hospital between 1981 and 1992. The rates of fungemia increased in recent years, 13.9% (1981-1985), 12.1% (1986-1988) and 16.9% (1989-1992). The isolated fungi were Candida parapsilosis (25.7%), C. albicans (24.8%), C. tropicalis (14.2%), Trichosporon beigelii (10.6%), C. glabrata (8.0%) and so on. The major fungi were T. beigelii and C. glabrata in patients with hematologic malignancies, whereas they were C. albicans and C. parapsilosis in patients with non-hematologic diseases and C. glabrata increased in both groups. Prophylactic or emiric administration of antifungal agents probably influenced the difference of the causative organisms in the two groups.

Adolescent↗