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N Hayashida

Publications and source records attributed to N Hayashida.

At least 109 records · Page 6Linked to original sources

Cloning and characterization of a plant gene encoding a protein kinase.

The cloning and sequence analysis of a gene that encodes a homologue of protein kinase (PK) from Arabidopsis thaliana is reported. We screened a genomic DNA library of A. thaliana using as probes oligodeoxyribonucleotides or fragments from the polymerase chain reaction that correspond to conserved regions in the catalytic domains of various PKs. One genomic clone, named Atpk5, was sequenced and analyzed. Transcripts of the corresponding gene, Atpk5, were detected in root, leaf and flower tissues by Northern blot analysis. The deduced amino acid sequence of the putative product of Atpk5 resembles those of kinases that phosphorylate ribosomal protein S6, cAMP-dependent PKs and protein kinase C. From the results of sequence comparisons, the ATPK5 protein appears to be a member of a subfamily of Ser/Thr-PKs specific to plants.

Amino Acid Sequence↗

Cloning and characterization of two cDNAs encoding casein kinase II catalytic subunits in Arabidopsis thaliana.

Two cDNA clones, ATCKA1 and ATCKA2, encoding casein kinase II (CKII) catalytic subunits, were cloned from Arabidopsis thaliana and their nucleotide sequences were determined. Both cDNAs contain 999 bp open reading frames and are 94% identical on the amino acid sequence level. The deduced amino acid sequences of ATCKA1 and ATCKA2 are very similar to that of the human CKII catalytic alpha subunit (72% homology). Northern blot analysis indicates that the ATCKA1 and ATCKA2 mRNAs are present in all plant organs, but that ATCKA1 transcript levels are quite low compared to those of ATCKA2. Genomic Southern blot analysis suggests that there are at least three CKII genes in the A. thaliana genome. We expressed the ATCKA1 and ATCKA2 cDNAs in Escherichia coli using a pET vector derivative and analyzed the expressed protein in vitro. The expressed ATCKA1 protein phosphorylated casein using either ATP or GTP. This activity was inhibited by heparin, indicating that the expressed protein has activity similar to those reported for animal and yeast CKII.

Amino Acid Sequence↗

The direct effect of graft compliance mismatch per se on development of host arterial intimal hyperplasia at the anastomotic interface.

To study the direct and sole effect of compliance mismatch on anastomotic intimal hyperplasia of the host arterial wall and to minimize possible confounding factors, dogs with a low thrombotic potential were selected as experimental subjects. Externally supported 6 cm x 5 mm Dacron grafts with a compliance value of approximately 1/300 of the host artery were implanted into the carotid arteries with end-to-end anastomoses on one side and end-to-side anastomoses on the other. The control graft was an autogenous carotid artery segment 4 cm in length transplanted into the femoral artery. Eight cases (24 grafts) were studied for 1 year and three (nine grafts) for 6 months. All were patent throughout the study period except for two noncompliant grafts with end-to-end anastomoses; thrombosis was the documented cause of occlusion. For the patent grafts, follow-up arteriograms showed no progressive narrowing of noncompliant anastomoses. Whether compliant or noncompliant, light microscopy studies showed slight intimal thickening within 1 to 2 mm of the anastomotic line, possibly the result of the normal healing response to stitch and surgical trauma. Quantitatively, 22 measurements representing longitudinal and circumferential thickness of the neointima were taken at each of the 40 patent noncompliant and 22 patent compliant control anastomoses. There was no statistically significant difference in anastomotic neointimal thickness in compliant and noncompliant grafts or for the different implantation periods. These data suggest that graft/host artery compliance mismatch does not cause arterial intimal hyperplasia at the anastomotic interface.

Anastomosis, Surgical↗

Which techniques of cardioplegia prevent ischemia?

One hundred seven patients undergoing coronary artery bypass grafting were randomized to receive warm antegrade (n = 21), warm retrograde (n = 22), cold antegrade (n = 20), cold retrograde (n = 22), or intermittent cold antegrade (n = 22) blood cardioplegia. Myocardial oxygen consumption and lactate production, adenine nucleotides, and adenine nucleotide degradation products were measured during the operation, and creatine kinase-MB release was assessed postoperatively. Warm cardioplegia resulted in greater myocardial lactate production than cold cardioplegia (p = 0.048). Retrograde cardioplegia was associated with greater lactate production than antegrade cardioplegia (p = 0.015). Adenosine triphosphate depletion was similar among groups. However, poorly diffusible metabolites of adenosine triphosphate accumulated to the greatest extent in the intermittent cold group. Levels of hypoxanthine were highest after warm retrograde cardioplegia. Operative mortality and morbidity were low and were not different among groups. In summary, none of the five techniques of cardioplegia evaluated in this study was able to completely prevent myocardial ischemia. Anaerobic lactate production was minimized with cold cardioplegia and with antegrade cardioplegic delivery. Hypothermia may have impaired regeneration of adenosine triphosphate, however, particularly in association with inadequate or intermittent cardioplegic flow.

Adenosine Monophosphate↗

Use of the right gastroepiploic artery as a pedicled arterial graft for coronary revascularization.

Between April 1988 and August 1991, the right gastroepiploic artery (RGEA) was used as a pedicled arterial graft for coronary arterial bypass grafting (CABG) in 44 patients. Their ages ranged from 8 to 72 years (mean: 58.7 years), and body size was small for 21 patients (body surface area < 1.6 m2). The mean number of distal anastomoses was 3.2 +/- 0.7 per patient. The RGEA was anastomosed to the right coronary system in 35 patients and to the left in 9 patients. Perioperative vasospasm of the RGEA occurred in 4 patients, but no vasospasm was seen after intraluminal injection of diluted papaverine hydrochloride was used in the last 9 patients. The size of the RGEA at the site of anastomosis was 1.9 +/- 0.4 mm in diameter. The RGEA was harvested in 48 patients; however, two of the RGEAs were smaller than 1.0 mm in diameter and two showed severe calcification with stenosis of more than 75%. Consequently, those conduits were not used. Indications for the use of the RGEA were: relatively young age for 17, matching size of the coronary artery and the RGEA for 11, poor quality of the internal thoracic artery (ITA) or saphenous vein graft (SVG) for 10, lower leg atherosclerosis in 3, a diseased ascending aorta in 2, and Kawasaki disease in 1. The patency rate of the RGEA for 36 patients was 94.4% and relief of angina 95.5%. An exercise tolerance test performed within 2 months after operation showed improved capacity (mean 7.2 metabolic units).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Molecular heterogeneity of photosystem I. psaD, psaE, psaF, psaH, and psaL are all present in isoforms in Nicotiana spp.

The protein composition of photosystem I (PSI) was examined in Nicotiana spp. by high-resolution polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and immunoblot analysis. Five PSI proteins show polymorphism in an amphidiploid species, Nicotiana tabacum, but not in its ancestral diploid species, Nicotiana sylvestris and Nicotiana tomentosiformis. These Nicotiana spp. appear to have at least 18 PSI proteins per genome that range in molecular mass from 3 to 20 kD. They include the products of nuclear genes psaD, psaE, psaF, psaG, psaH, psaK, and psaL, the product of chloroplast gene psaC, N-terminally blocked proteins of 4.5 and 3.0 kD, and an unidentified protein of 12.5 kD. The psaD, psaF, psaH, and psaL products have two isoforms each that are distinguished by different mobilities in polyacrylamide gel electrophoresis, and the psaE product has four isoforms. The two isoforms of the psaD product have distinct amino acid sequences, indicating that they are encoded by different genes within the genome. Four isoforms of the psaE products can be classified into two groups by N-terminal amino acid sequence, indicating that at least two psaE genes are present in the genome. To examine whether the polymorphic nature of PSI is peculiar to Nicotiana spp., we carried out immunoblot analysis of the psaD and psaE products in isogenic lines of tomato (Lycopersicon esculentum), Arabidopsis thaliana, red bean (Vigna angularis), and corn (Zea mays). Two electrophoretically distinct isoforms were found for the psaD products of tomato, A. thaliana, and corn, and two isoforms of psaE products were detected in tomato, A. thaliana, and red bean. These results suggest that the nuclear-encoded subunits of PSI, except for the psaG and psaK products, generally have two isoforms.

Amino Acid Sequence↗

Effects of zopiclone on slow wave sleep and spontaneous K-complexes for normal healthy young adults.

Benzodiazepine (BZD) hypnotics have been known to decrease, to some degree, human slow wave sleep (SWS) although they elevate the arousal threshold during sleep. Zopiclone (ZPC), a cyclopyrrolone hypnotic, has attracted the interest of sleep researchers because an increase in human SWS has been reported. Since the increase has not been fully confirmed by all of the studies, the authors investigated the effects of ZPC 10 mg on SWS and the K-complexes for 7 healthy young adults because there is evidence indicating that delta waves consisting of SWS and the spontaneous K-complexes are identical. SWS and st. 4 sleep did not decrease on any of the ZPC nights but st. 3 sleep showed a tendency to reduce on the 1st ZPC night. The frequency of the K-complexes decreased significantly on the 2nd ZPC night and tended to reduce on the 1st ZPC night. Moreover, a significant positive correlation was noted between the decrease rates of SWS and the K-complexes on both the ZPC nights. The authors, therefore, could not obtain any findings suggesting an increase in SWS with ZPC.

Administration, Oral↗

Compartmentalization in the pig latissimus dorsi muscle.

Portions of the latissimus dorsi (LD) muscle are frequently employed as free muscle or myocutaneous grafts. The functional consequences for both the graft and the remaining donor tissue must depend in part on the neural organization of the muscle. Previous anatomical and clinical reports have suggested that the LD is organized into independently innervated segments, but experimental documentation has been lacking. This study investigated the neural organization of the LD in pigs using (1) synchronous electromyography (EMG) of several sites within the LD and motion analysis of the shoulder and forelimb, and (2) dissection and stimulation of the primary branches of the thoracodorsal nerve, followed by histochemical analysis, to delineate the areas innervated by each. The findings indicated that while there is minor overlap between adjacent segments, the LD can be considered as consisting of three semi-independent compartments. Further, the teres major is linked to the LD functionally as well as anatomically, so that the two muscles can be considered as a four-part complex.

Animals↗

[The effect of additional albumin with optimal concentration on the reperfusion after preservation of isolated rat hearts].

We studied the effect of additional albumin in preservation solution on reperfusion after immersion of isolated rat hearts by measuring cardiac function, myocardial enzymes and calcium. Male Wistar rats weighing 300 gr to 450 gr were used. Isolated rat hearts were arrested by cardioplegic solution and washed out with preservation solution. Then, the hearts were immersed at 4 degrees C for six hours. The group was divided into four by the concentration of additional albumin in preservation solution which basically consisted of Euro-Collins solution. In control group, the cardiac function was immediately measured after the heart was isolated. Albumin was not added in group I (n = 16), 2% of albumin in group II (n = 18), 5% of albumin in group III (n = 17) and 7% of albumin in group IV (n = 18). There were no significant differences between groups II and III in cardiac function and myocardial enzymes. The levels of myocardial malondialdehyde (nmol/g dry weight) and calcium (mumol/g dry weight) at 15 minutes after reperfusion were 279.3 +/- 38.1, 5.9 +/- 5.3 in group I; 243.3 +/- 86.5, 4.1 +/- 2.0 in group II; 217.1 +/- 106.6, 4.1 +/- 1.3 in group III and 274.9 +/- 77.1, 4.9 +/- 1.2 in group IV, respectively. Although no statistical significances were seen among those results, those data might suggest the relationship between the recovery of cardiac output and myocardial ATP contents. Those results also suggested that additional albumin with optimal concentration might inhibit reperfusion injury.

Albumins↗

[Direct implantation of the left coronary artery to the ascending aorta in Bland-White-Garland syndrome].

A seventeen-year-old male with Bland-White-Garland syndrome underwent direct implantation of the left coronary artery to the ascending aorta. Under cardiopulmonary bypass, the main pulmonary artery was completely transected and the left coronary artery (LCA) was excised with a cuff of the pulmonary artery wall. Then the proximal end of LCA was directly anastomosed to the ascending aorta. The postoperative course was excellent. It appears that this surgical procedure might be the most ideal repair both anatomically and hemodynamically to reconstruct the left coronary artery in Bland-White-Garland syndrome.

Adolescent↗

Clinical evaluation with exercise performance in twenty patients who underwent coronary artery bypass grafting with both the gastroepiploic and internal thoracic arteries.

Postoperative exercise performance was evaluated in 20 patients who underwent complete coronary revascularization with simultaneous right gastroepiploic artery and internal thoracic artery grafts for ischemic heart disease and exhibited patency of all grafts on postoperative angiograms. Three patients received only arterial grafts, and 17 simultaneously received a saphenous vein graft. Forty five right gastroepiploic artery grafts were harvested during this study, but two were not used because of foci of severe calcification. The right gastroepiploic artery was grafted to the distal right coronary artery in 17 patients and to the distal obtuse marginal branches in three patients, accompanied by an internal thoracic artery graft to the left anterior descending artery in seventeen, to the diagonal branch in three, and to the proximal right coronary artery in one patient. A postoperative exercise test with a bicycle ergonometer was administered 6 to 12 weeks after the operation, and the results are reported after conversion into metabolic units. The preoperative exercise test resulted in 3.6 +/- 1.9 metabolic units for 18 patients tested, and the postoperative metabolic units were 7.8 +/- 1.3 for 20 patients. Left ventricular wall motion was analyzed by regional ejection fraction before and after coronary artery bypass grafting in 14 patients who received an right gastroepiploic artery graft for the right coronary system. The mean regional ejection fraction of the posterobasal or diaphragmatic wall was 28.0% or 28.2% before operation and improved to 43.1% or 43.2% after coronary artery bypass graft, respectively. The flow of right gastroepiploic artery seemed to distribute adequately to the revascularized area. Long-term results have not yet been proved; the use of simultaneous right gastroepiploic artery and internal thoracic artery grafts, however, thus produced excellent results, as seen from improvements in both left ventricular wall motion and early postoperative exercise performance.

Adult↗

Characterization of a gene that encodes a homologue of protein kinase in Arabidopsis thaliana.

Cloning and analysis of a gene that encodes a homologue of protein kinase (PK) from Arabidopsis thaliana is reported. Oligodeoxyribonucleotides (oligos) corresponding to conserved regions in catalytic domains of various PKs were used for polymerase chain reaction (PCR) amplification with genomic DNA from A. thaliana as template, in an attempt to identify genes encoding PK in plants. We obtained several amplified DNA fragments that encoded part of a PK. We screened a genomic DNA library of A. thaliana with these oligos or PCR fragments as probes. Three genomic clones were obtained and one of them, named Atpk7, was sequenced and analyzed. Atpk7 was demonstrated by PCR to contain an intron. The mRNA transcribed from Atpk7 was detected predominantly in root tissue by Northern blot analysis. The transcription start point was determined by primer extension. The deduced amino acid (aa) sequence of the putative product of Atpk7 resembles those of S6 kinases, cyclic nucleotide-dependent PKs and calcium-dependent PKs. From this comparison of aa sequences, the ATPK7 protein is considered to be a member of a novel subfamily of Ser/Thr PKs in plants.

Amino Acid Sequence↗

Augmentation of interleukin-2 production after cardiac operations in patients treated with erythropoietin.

It has been reported recently that cardiac operations can be followed by a transient impairment of cell-mediated immunity. In this study we examined indices of cell-mediated immunity in patients undergoing cardiac operations. Twenty-five of the patients received erythropoietin (200 U/kg) daily for 2 weeks before and after operation, and 30 matched control patients did not receive erythropoietin. On postoperative day 1, the numbers of total T cells and helper/inducer T cells were significantly higher in erythropoietin-treated patients than in control patients. The ability of patients' cells to make interleukin-2 in vitro increased after erythropoietin injection in the preoperative period. By postoperative day 1, erythropoietin-treated patients exhibited a fall in interleukin-2 production that was significantly less than that in control patients; levels increased by day 2 to a mean value twice that of the preoperative baseline and more than four times the corresponding mean level in the control groups, and levels returned to the baseline range by postoperative day 14. Levels of interleukin-2 production in erythropoietin-treated patients were significantly higher than those in control patients at each interval tested through postoperative day 7. These findings indicate that erythropoietin treatment not only augmented levels of circulating erythrocytes but also improved indices of cell-mediated immunity. Although the mechanism responsible for this effect remains to be determined, the finding suggests that erythropoietin might help to ameliorate or prevent the impairment of immune function that can occur after cardiac operations.

Cardiac Surgical Procedures↗

Postoperative erythroderma after cardiac operations. The possible role of depressed cell-mediated immunity.

Erythroderma as a manifestation of graft-versus-host disease after cardiac operations with blood transfusion may occur more frequently in Japan than in other countries. We have seen this problem in five patients who, after heart operations, died with symptoms and signs characteristic of graft-versus-host disease: cutaneous eruption, fever, diarrhea, leukopenia associated with agranulocytosis, and liver dysfunction. In the three patients seen most recently, skin biopsy showed findings similar to those of graft-versus-host disease after bone marrow transplantation. In addition, immunologic investigation showed remarkable differences in the findings in these patients and in those who did not have a graft-versus-host disease-like syndrome after cardiac operations. In particular, interleukin-2 production in response to mitogen stimulation was markedly diminished after operation in our patients, and the ratio of OKT4+ cells to OKT8+ cells in peripheral blood was low, reflecting increased numbers of OKT8+ cells after the occurrence of symptoms. The results raise the possibility that transient depression of cellular immunity after cardiac operations with blood transfusion may contribute to the occurrence of postoperative acute graft-versus-host disease.

Aged↗

[Coronary artery bypass grafting: does the use of arterial graft for coronary artery bypass grafting increase surgical risk?].

Since April in 1988 coronary artery bypass grafting (CABG) was performed in 177 patients and the clinical results were compared in SVG-group (n = 37) in which only saphenous vein graft (SVG) was used as a graft conduit and AG-group in which one arterial graft (AG-1 group, n = 92) or more than two arterial grafts were used (AG-2 group, n = 48). In SVG-group the age was older than that in AG-group, while coronary vessels were most involved in AG-2 group and the mean number of distal anastomosis increased more in AG-group. The total pump time and aortic cross clamping time showed no significant differences among the groups. Furthermore, the occurrence of perioperative myocardial infarction, requirement of intra-aortic balloon pumping, frequency of re-chest open for hemorrhage, or sternal infection showed no significant differences among the groups. Postoperative hospital deaths were in four (three cardiac deaths) of SVG-group and four (one cardiac and two graft-versus-host disease) of AG-group. These results suggest that the use of AG does not increase surgical risk and AG can be positively used for CABG.

Adolescent↗