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Biomedical subjects

H Nishida

Publications and source records attributed to H Nishida.

At least 307 records · Page 17Linked to original sources
PubMed1994

[Seventy-seven coronary reoperations: incidence, indication and results].

As the number of patients who have undergone primary myocardial revascularization continues to burgeon, the number of potential candidates for a secondary myocardial revascularization has increased gradually. The number of secondary CABG at the Cleveland Clinic were performed, which represents 18% of the total CABG. However, the number of secondary CABG at The Heart Institute of Japan were performed, which represents of 5-10% of the annual CABG. There was one operative death (1.3%). The graft patency rate was 92.8%. Including non-cardiac death, the actuarial survival rate at 10 years was 88.2%, and events free rate including all deaths, the third time CABG, PTCA and myocardial infarction was 78.4% at 10 years.

Adult↗
PubMed1994

[Phrenic nerve injury following coronary artery bypass surgery: its clinical implication and management].

The hospital records of 80 patients undergoing coronary artery bypass surgery, including 19 patients using the "isolation pad", were reviewed to examine the prevalence of the phrenic nerve injury (PNI). All patients received ice slush for topical cooling during operation. The degree of the elevated diaphragm was evaluated objectively by "Diaphragmatic Elevation Index, DEI" calculated from the plain chest roentgenogram taken before and after the operation. Sixty-one patients without using the isolation pad were subdivided into 3 groups, mild (35), moderate (15), and severe (11) according to the degree of the elevated diaphragm, and compared along with those using the isolation pad. All groups could not be distinguished by clinical course. The degree of left diaphragmatic elevation was significantly high compared with that of right, but recovered significantly at discharge except 2 patients. Pulmonary complication was highly associated with the "severe" groups. Because PNI is often transient and of little clinical significance, it is sometimes neglected. But considering the high frequency of the development of pulmonary complication, proper protective measure should be undertaken. Utilization of the isolation pad was effective means in terms of protection of phrenic nerve.

Coronary Artery Bypass↗
PubMed1993

Crystallization and preliminary X-ray diffraction studies of photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans.

Photolyase (photoreactivating enzyme) from the cyanobacterium Anacystis nidulans was crystallized by the hanging drop vapor diffusion procedure using ammonium sulfate as a precipitant. The pale-yellow crystals were grown to a size of 0.4 mm in length and 0.1 mm in diameter. They belong to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2 with unit cell dimensions of a = b = 90.7 A and c = 135 A. Assuming that the asymmetric unit contains one molecule, the Vm value is calculated as 2.6 A3/dalton. The crystals are stable towards X-ray exposure and diffract beyond 2.5 A resolution.

Crystallization↗
PubMed1993

[Percutaneous hot water injection therapy (PHoT) for hepatic tumors: a clinical study].

Percutaneous ethanol injection therapy (PEIT) has become widely used in the treatment of HCC. However, the indications for this method are limited by the toxicity of ethanol itself. Against this background, the authors turned their attention to the heat coagulation necrosis effect induced by boiled physiological saline (hot water) and devised percutaneous hot water injection therapy (PHoT) as a new local treatment method. PHoT was performed a total of 41 times in 13 patients (16 nodules) with HCCs measuring < or = 3 cm. Changes in AFP values, CT findings, angiographic findings before and after treatment, and histopathological findings of needle biopsy or resected specimen were investigated. AFP values decreased in all of the seven patients who initially showed high values. On CT, all lesions receiving PHoT became hypodense, with this change thought to indicate necrosis. Disappearance of the tumor stain was confirmed in the four patients in whom follow-up angiography was performed. In the six patients in whom needle biopsy was performed, disappearance and scaring of tumor cells were observed, while in the one patient in whom the tumor was resected, complete necrosis of the tumor was confirmed. PHoT, despite a small number of punctures, shows good anti-tumor effects, and has promise not only as a curative local treatment method for small HCCs but also in combination with TAE for large HCCs.

Aged↗
PubMed1993

The higher fungus Protomyces inouyei has two group I introns in the 18S rRNA gene.

The nucleotide sequence of the small-subunit rRNA (18S rRNA) coding gene in the higher fungus Protomyces inouyei contains two group I introns. This is the first report of two group I introns in the 18S rRNA coding region. Based on the comparison of the two introns of Protomyces inouyei with those of the green alga Ankistrodesmus stipitatus, and the other two higher fungi Pneumocystis carinii and Ustilago maydis, the Protomyces introns are group I introns containing the highly conserved sequence elements P, Q, R, and S. Intron A of Protomyces inouyei is located in the same position as in Pneumocystis carinii while intron B shares the location with that in Ustilago maydis. The phylogenetic relationships strongly support horizontal transfer of these group I introns.

Ascomycota↗
PubMed1993

Effect of 13-hydroperoxyoctadecadienoic acid on 15-hydroxy prostaglandin dehydrogenase activity in rabbit kidney cortex.

The effect of a hydroperoxy adduct of linoleic acid, 13-hydroperoxyoctadecadienoic acid (13-HPODE), on 15-hydroxy prostaglandin dehydrogenase activity in rabbit kidney cortex was examined. 13-HPODE inhibited the 15-hydroxy prostaglandin dehydrogenase activity at concentrations ranging from 1 to 10 microM. The effect was concentration-dependent and the concentration required for 50% inhibition was approximately 3 microM. Linoleic acid and 13-hydroxyoctadecadienoic acid (13-HODE) exhibited weaker inhibition of the enzyme activity than did 13-HPODE (linoleic acid, 30% inhibition at 10 microM; 13-HODE, 45% inhibition at 10 microM). Studies utilizing Fe2+ (a catalyst of peroxide decomposition), and mannitol or dimethylsulfoxide (a hydroxy radical scavenger) revealed that the inhibitory effect of 13-HPODE on the 15-hydroxy prostaglandin dehydrogenase activity is not due to the hydroxy radicals which are expected to be formed from 13-HPODE and that the hydroperoxy functional group is a prerequisite. The inhibition by 13-HPODE was uncompetitive and non-competitive with regard to NAD+ and prostaglandin E2, respectively. These results suggest that 13-HPODE has the potential to modulate the prostaglandin catabolism by affecting the 15-hydroxy prostaglandin dehydrogenase activity.

Animals↗
PubMed1993

A multicenter randomized trial of high frequency oscillatory ventilation as compared with conventional mechanical ventilation in preterm infants with respiratory failure.

A multicenter randomised trial was conducted in nine neonatal centers in Japan to re-evaluate the safety and the efficacy of high frequency oscillatory ventilation using the piston type oscillator (Hummingbird) in the treatment of respiratory failure in preterm infants weighing between 750 and 2000 g at birth. A total of 92 infants were enrolled in the study. Forty-six infants were allocated to high frequency oscillatory ventilation and 46 infants to conventional mechanical ventilation. There were no differences in sex, birth weight, gestation and Apgar score between groups. The study was begun 2.0 +/- 1.6 h (mean +/- S.D.) after birth in the high frequency oscillation group and 1.7 +/- 1.5 h after birth in the conventional mechanical ventilation group. The absence of intraventricular hemorrhage was confirmed by echography in all cases before beginning ventilation. Mortality was similar in high frequency oscillatory ventilation and conventional mechanical ventilation (0 and 2%). The incidence of intraventricular hemorrhage was also similar in the high frequency and conventional mechanical ventilation groups (15 and 13% overall; 4 and 2% in grades III and IV, respectively). Nine percent of the infants in high frequency oscillatory ventilation and 13% in conventional mechanical ventilation developed bronchopulmonary dysplasia, but the difference was not significant. The frequency of air leaks was also equal in both groups. Periventricular leukomalacia was detected in 9% of infants on conventional mechanical ventilation and 2% on high frequency oscillation, but the difference was not significant. Mean airway pressure was significantly higher in the high frequency oscillatory ventilation group and the infants on high frequency oscillation showed a significantly higher arterial to alveolar oxygen tension ratio after 6 h of treatment. These results suggest that high frequency oscillatory ventilation does not increase the risk of severe complications such as air leaks, intraventricular hemorrhage or periventricular leukomalacia when it is used by experienced neonatologists. Indeed high frequency oscillatory ventilation helps provide better oxygenation with higher mean airway pressure without increasing the risk of bronchopulmonary dysplasia and severe complications such as air leaks and intraventricular hemorrhage.

Bronchopulmonary Dysplasia↗
PubMed1993

Effects of reactive oxygen species on arachidonic acid metabolism in rabbit platelets.

Rabbit platelets were exposed to a reactive oxygen species (ROS) generating system (xanthine plus xanthine oxidase) to explore the effect of ROS on the formation of 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE), thromboxane (TX) B2, and 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) from exogenous arachidonic acid. Xanthine plus xanthine oxidase suppressed the production of 12-HETE, TXB2, and HHT by 65-69%. This effect was reversed by addition of catalase to the ROS generating system but not by superoxide dismutase, mannitol, or dimethylsulfoxide, indicating that H2O2 is the responsible metabolite. These results suggest that H2O2 plays an important role in the regulation of platelet cyclo-oxygenase and lipoxygenase activities.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1993

Enhanced ventricular recovery from high dose glucose, insulin and potassium with cardiopulmonary bypass support prior to cardioplegic arrest.

The concept that a beneficial preconditioning effect in ventricular recovery exists using high dose glucose (0.5 mg/kg), insulin (0.3 unit/kg), and potassium (0.2 mmol/kg) (GIK) with 20 min of normothermic cardiopulmonary bypass support (CPB) prior to 60 min of cardioplegic arrest (CA) was tested using 32 mongrel dogs divided into four subset test groups. Group 1 was given GIK and 20 min of CPB prior to CA, Group 2 was given GIK systemically over 10 min but no CPB prior to CA, Group 3 underwent 20 min of CPB without GIK and Group 4 was the control group with no GIK and no CPB assist. To focus specifically on in vivo ventricular recovery, dP/dT (mmHg/sec), developed pressure (dP) (mmHg), and segmental shortening (SS) (%) were measured prior to CPB, then 15, 30, 60, and 90 min after weaning from CPB, while left atrial pressure was kept constant. The average dP/dT (% recovery) at 60 min in Group 1 was 1,454 (122%) and significantly higher (P < or = 0.05) than Groups 2: 1,189 (99%), 3: 1,027 (79%) and 4: 1,030 (82%). Developed pressure at 90 min (% recovery) in Group 1, 88 (111%) was also better than Groups 3, 74 (86%), and 4, 72 (87%) (P < or = 0.05). Segmental shortening (% recovery) at 30 min was better in Group 1 (94%) than in Groups 2 (59%), 3 (73%) and 4 (68%). We conclude that GIK added to 20 min of CPB support prior to cardioplegic arrest enhances post CPB ventricular recovery and weaning from CPB.

Animals↗
PubMed1993

Outcome of infants born preterm, with special emphasis on extremely low birthweight infants.

The outcome of extremely low birthweight (ELBW) infants has been reviewed from published articles and up-to-date data from Japan. The mortality rate of these infants declined significantly from over 90% to below 50% after the introduction of intensive care in the 1970s, but the incidence of major neurological sequelae remained steady at around 20%. Similarly, the incidence of major neurological sequelae did not increase along with the decrement of birthweight, although the mortality rate increased significantly. Long-term follow-up of ELBW children until school age has revealed poor school performance in spite of the absence of major neurological sequelae and the attainment of average intelligence quotient scores. Physical growth is retarded initially but generally catches up by the age of 8-9 years. In Japan, the neonatal mortality rate of ELBW infants declined from 56% in 1981 to 25% in 1989 with an increased birth rate of ELBW infants. In ELBW infants cared for at Tokyo Women's Medical College during 1984-90, the survival rate was 112 out of 134 (84%) and the incidence of major neurological sequelae was 15 out of 87 (17%) at 1-8 years old. The viability limit of ELBW infants has been discussed based on recent data. As a result of the rapid progress of medical care of ELBW infants, their viability limit as defined in the Eugenic Protection Law in Japan was amended from 24 completed weeks of gestation to 22 completed weeks in 1991.

Birth Weight↗
PubMed1993

Phylogenetic relationships among Taphrina, Saitoella, and other higher fungi.

To determine the phylogenetic placement of the major groups of higher fungi, we sequenced the DNA sequences from the small-subunit ribosomal RNA (18S rRNA) coding regions from Taphrina wiesneri (synonym: T. cerasi) and Saitoella complicata and compared them to 18S rRNA sequences from the oomycetes, chytridiomycetes, zygomycetes, ascomycetes, and basidiomycetes. Here we demonstrate that the ascomycetes have at least two major evolutionary lineages. Taphrina wiesneri and Saitoella complicata form a monophyletic branch that diverged prior to the separation of other ascomycetes. The same treatment could be accorded to Schizosaccharomyces pombe.

Ascomycota↗
PubMed1993

Mechanical circulatory support for postcardiotomy ventricular failure: the Heart Institute of Japan experience 1984-1992.

In the last 9 years, 30 patients received assisted circulation or a ventricular assist device after open-heart operations at the Heart Institute of Japan. After cardiovascular surgery, 9 of those patients underwent venoarterial bypass, 10 had biventricular bypass, 7 had left ventricular bypass, and the remaining 4 received a left ventricular assist device. Of the first 15 patients, only 3 (20%) were discharged from the hospital. In contrast, 7 (46.7%) of the last 15 patients were discharged without major complications. With respect to complications, bleeding and ventricular arrhythmia (immature weaning) decreased with low-heparinized isolated left ventricular supports. 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↗
PubMed1993

Percutaneous cardiopulmonary support as the second generation of venoarterial bypass: current status and future direction.

We have developed a new percutaneous cardiopulmonary support (PCPS) system in cooperation with Terumo Corporation, called the Emergency Bypass System (EBS). This preassembled system is unique in terms of its small priming volume (470 cc), fully automatic priming function, originally developed membrane oxygenator, and Capiox straight path centrifugal pump. The priming process takes only 5 min. We have used this system in 4 patients (all were male; mean age 56 years, range 35-73 years). The duration of assist ranged from 15 min to 210 h. Maximum bypass flow ranged from 2.2 to 3.6 L/min, systemic circulation was very well maintained, and urinary output was acceptable. Although the centrifugal pump was in good working condition, we had to change the oxygenator because of serum leakage 36 to 48 h after initiation of the assist. One patient was weaned from the PCPS, but died of brain death. The other patients could not be weaned from the PCPS. The cause of death in these patients was irreversible myocardial damage. Disseminated intravascular coagulopathy triggered by surgical trauma related to various procedures developed in 2 patients during assist and was the cause of cessation of the assist. Problems to be ratified and future directions in the EBS and PCPS were earlier introduction through the establishment of clear indications and endpoint, heparin coating, improvement in durability of the oxygenator, and cost.

Adult↗
PubMed1993

Development of the Terumo Capiox centrifugal pump and its clinical application to open heart surgery: a comparative study with the roller pump.

We have developed the Terumo Capiox centrifugal pump (CXP), which consists of a rotor having a unique straight-path design to reduce pump rotational speed without decreasing hydraulic efficiency. The CXP was tested in vitro for blood trauma with a specially designed test circuit using fresh bovine blood. The Biopump (BP) (Medtronic, Minneapolis, MN, U.S.A.) and the roller pump (RP) were used as controls. The CXP demonstrated the smallest elevation of free plasma hemoglobin compared with the BP and the RP. The CXP was then applied to cardiopulmonary bypass (CPB) in 10 patients (CXP group) who underwent elective coronary artery bypass grafting (CABG), and the results were compared with those for a comparable roller pump group (RP group). Free plasma hemoglobin level, platelet count, and serum beta-thromboglobulin (beta-TG) level were measured during CPB. There were no CXP-related complications nor hemodynamic abnormalities during CPB. The CXP group demonstrated less hemolysis and less platelet depletion than the RP group. Furthermore, the serum beta-TG level was significantly lower in the CXP group than in the RP group. The CXP showed excellent hemodynamic performance with less blood trauma both in vitro and in clinical application to open heart surgery. Thus, the CXP has significant potential to be safely applied to CPB for open heart surgery and circulatory support.

Animals↗
PubMed1993

Clinical experience of assisted circulation with a centrifugal pump at Tokyo Women's Medical College.

In postpericardiotomy patients, the use of pulsatile pumps is limited in a semielective fashion to patients whose postoperative marginal hemodynamics are expected preoperatively. Since 1989, 25 patients have undergone assisted circulation with a centrifugal pump: 15 (60%) were weaned from the pump, and 7 (28%) survived. In 1988, we heparin-coated the Bio-Pump using the Carmeda technique and developed a totally heparin-coated left heart bypass system together with heparin-coated cannulas and tubing. Four postpericardiotomy patients underwent left heart bypass with this system without heparin for 2 to 9 days. No thrombus was detected in the system. Left heart bypass with a centrifugal pump has been used as a supportive method in surgical repair of thoracic or thoracoabdominal aortic aneurysm. To overcome intraoperative hypothermia and hypoxia, we used a small membrane oxygenator with a heat exchanger in 11 patients, and postoperative recovery dramatically improved. We also developed a preassembled percutaneous cardiopulmonary support (PCPS) system with an automatic priming function using Terumo's straight path centrifugal pump and small membrane oxygenator in cooperation with the Terumo Corporation. This system was used in a patient with cardiogenic shock after acute myocardial infarction. The setup and priming took only 5 min, and 2.5-3.5 L/min of flow was obtained.

Adult↗
PubMed1993

Monitoring neonatal peripheral circulation by electrocardiogram-to-oximeter pulse velocity.

The plethysmo time interval (PTI) is the time interval between the beginning of QRS complex on ECG and the upstroke of the pulse wave on the plethysmogram as measured by a pulse oximeter. We examined whether measuring the PTI has clinical value for evaluating neonatal peripheral circulation. We correlated PTI values and measured, from the hand and foot, height and body weight of 14 neonates. PTI was strongly correlated with height (R2 = 0.85) and body weight (R2 = 0.78). Height was especially highly correlated, because PTI is principally affected by the distance from the heart to the measured site. We also measured PTI on three clinical cases (patent ductus arteriosus, hypovolemia, and persistent pulmonary hypertension of the newborn). PTI was shortened in cases of peripheral circulatory impairments, because pulse wave velocities increased due to the contraction of arterioles. We conclude that the PTI can evaluate the peripheral circulatory status of the neonate by applying a new principle of pulse oximeter that is widely used in neonatal intensive care units.

Blood Circulation↗