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H Masaki

Publications and source records attributed to H Masaki.

At least 127 records · Page 7Linked to original sources
PubMed1996

Analysis of Cre1 binding sites in the Trichoderma reesei cbh1 upstream region.

A 1.5-kb XbaI-SacII fragment containing the upstream region of the Trichoderma reesei cellobiohydrolase I gene (cbh1) has been sequenced. The 1.5-kb fragment contains eight 6-bp sites having an identical or similar sequence to the consensus sequence for binding a catabolite repressor, Aspergillus nidulans CreA. Results of binding assays with the maltose-binding protein::Cre1(10-131) fusion protein (Cre1 is a catabolite repressor of T. reesei) and the cbh1 upstream region revealed that a 504-bp XbaI-NspV fragment (nucleotide position -1496 to -993) bearing three 6-bp sites, A1, A2, and A3, and a 356-bp NspV-MunI fragment (nucleotide position -994 to -639) bearing three 6-bp sites, B1, B2, and B3, were shifted in the electrophoretic mobility shift assay. DNase I footprinting experiments showed that the 6-bp sites A2, B1, B2, and B3 were protected from DNase I digestion.

Base Sequence↗
PubMed1996

Cloning, sequencing, and expression of the cellulase genes of Humicola grisea var. thermoidea.

We have cloned an endoglucanase (EGI) gene and a cellobiohydrolase (CBHI) gene of Humicola grisea var. thermoidea using a portion of the Trichoderma reesei endoglucanase I gene as a probe, and determined their nucleotide sequences. The deduced amino acid sequence of EGI was 435 amino acids in length and the coding region was interrupted by an intron. The EGI lacks a hinge region and a cellulose-binding domain. The deduced amino acid sequence of CBHI was identical to the H. grisea CBHI previously reported, with the exception of three amino acids. The H. grisea EGI and CBHI show 39.8% and 37.7% identity with T. reesei EGI, respectively. In addition to TATA box and CAAT motifs, putative CREA binding sites were observed in the 5' upstream regions of both genes. The cloned cellulase genes were expressed in Aspergillus oryzae and the gene products were purified. The optimal temperatures of CBHI and EGI were 60 degrees C and 55-60 degrees C, respectively. The optimal pHs of these enzymes were 5.0. CBHI and EGI had distinct substrate specificities: CBHI showed high activity toward Avicel, whereas EGI showed high activity toward carboxymethyl cellulose (CMC).

Amino Acid Sequence↗
PubMed1996

Cloning, sequencing and transcriptional regulation of the draT and draG genes of Azospirillum lipoferum FS.

From Azospirillum lipoferum (Al) FS, a nitrogen-fixing bacterium isolated from the rhizosphere of rice, we cloned and sequenced draT, encoding dinitrogenase reductase ADP-ribosyltransferase, and draG, encoding dinitrogenase reductase-activating glycohydrolase. The nucleotide sequences of draTG showed extensive similarity to the same genes from Azospirillum brasilense, Rhodospirillum rubrum and Rhodobacter capsulatus, and they are assumed to be co-transcribed as a single operon. When this draTG operon was introduced into Klebsiella oxytoca, this organism acquired the ability to respond to extracellular NH(+4) ions with reversible inhibition of nitrogenase activity, similar to that seen in Al FS. We constructed a plasmid containing a draT::lacZ gene fusion and found that beta-galactosidase activity was detected under microaerobic conditions, regardless of NH(+4) concentration, but not under aerobic conditions. This indicates that the transcription of draTG responds to the level of oxygen, but not to that of NH(+4) ions.

ADP Ribose Transferases↗
PubMed1996

Isolation and characterization of the nuclease O gene (nucO) from Aspergillus oryzae.

Nuclease O in the mycelia of Aspergillus oryzae has been purified 55-fold by successive steps of chromatography from the filtrate of the autolyzate. The molecular mass of nuclease O was 32 kDa, as estimated by SDS polyacrylamide-gel electrophoresis. The nuclease O gene (nucO) encoding this enzyme was cloned and sequenced. The open reading frame is interrupted by four introns with conserved splice sites and contains 328 amino-acid residues of the mature enzyme. A. nidulans transformants obtained by introduction of the cloned nucO gene produced 2.5-times as much nuclease O as the wild-type strain, showing that the cloned DNA fragment encodes nuclease O.

Amino Acid Sequence↗
PubMed1996

Amyloid goiter: radiological study in a case presenting hypothyroidism.

We report herein a case of amyloid goiter associated with rheumatoid arthritis in which hypothyroidism was observed. A 52-year-old housewife who had suffeed from rheumatoid arthritis for 15 years was referred to our hospital because of general fatigue. On admission, a large goiter was observed. Laboratory data showed primary hypothyroidism. Renal biopsy and gastric mucosa biopsy showed amyloid deposition of AA-type. Thyroid biopsy showed massive amyloid involvement. Although the findings of iodine-123 scintigraphy, technetium-99m pertechnetate scintigraphy, computed tomography and magnetic resonance image studies were similar to those for goiter associated with chronic thyroiditis, tallium-201 chloride scintigraphy gave a differing result, demonstrating absent uptake at 3 hours in this case. Replacement therapy with levothyroxine relieved the symptoms. This case was unusual in that amyloid goiter presented clinically as hypothyroidism. Absence of tallium-201 chloride uptake at 3 hours may be a diagnostic specificity for amyloid goiter in differentiating its hypothyroidism from that caused by chronic thyroiditis.

Amyloid↗
PubMed1996

Central nuclei and spinal pathways in feedback inhibitory spinal cord potentials in ketamine-anaesthetized rats.

It has been suggested that heterosegmentally activated slow positive potentials (HSP), recorded from the spinal cord of rat and humans, are feedback inhibitory potentials. The present study was carried out to define ascending and descending spinal tracts and the sites of central nuclei involved in the production of these HSP, and the effects of ketamine on these central nuclei. The spinal cords in ketamine-anaesthetized rats were transected to determine the ascending and descending tracts involved in the production of hindpaw (HP) and forepaw (FP) HSP, respectively. Lesions of the brain at various levels were performed stereotactically during ketamine anaesthesia. Dorsal one-third resection of the cord at the T8-9 level did not affect HSP significantly, while contralateral lesion of the dorsal two-thirds of the cord decreased FP-HSP but not HP-HSP during ketamine. Bilateral transection of the ventral one-third of the cord abolished both HSP. Ablation of the cerebral cortex, cerebellum, thalamus, midbrain and pons did not affect HSP significantly. However, transection of the middle medulla decreased, while transection of the most caudal part of the medulla completely abolished both HSP. Ketamine decreased HSP even in the medulla-spinal cord preparation and the segmental slow positive wave in spinalized animals. In ketamine-anaesthetized rats, ascending and descending spinal tracts involved in the production of HP-HSP and FP-HSP are located bilaterally in the ventrolateral quadrant and in the contralateral lateral funiculus and ventrolateral quadrant, respectively. Principal central nuclei feeding back HSP might be situated diffusely in the medulla down to the caudal part. Ketamine is suggested to suppress these inhibitory feedback potentials predominantly at, and partly even below, the level of the medulla.

Anesthetics, Dissociative↗
PubMed1996

Construction and characterization of pyocin-colicin chimeric proteins.

Chimeric proteins were constructed from pyocin S1 or S2 and colicin E3 or E2, and their characteristics were investigated with special reference to the domain structure. The nuclease domains were interchangeable between two bacteriocins so that a new kind of pyocin, with RNase activity, was created. A bacteriocin which can kill both Pseudomonas aeruginosa and Escherichia coli was also constructed. Investigations with various chimeric proteins indicate that the translocation domain as well as the receptor-binding domain is species specific. Inhibition of lipid synthesis, which is characteristic of pyocins, was also observed with chimeric pyocins carrying the DNase domain of colicin E2 but not with those carrying the RNase domain of E3. Thus, the DNase domain is responsible for the inhibition of lipid synthesis.

Bacterial Proteins↗
PubMed1996

Modulation of pump function by mutations in the first transmembrane region of Na(+)-K(+)-ATPase alpha 1-subunit.

The Cys in the first transmembrane region of the Na(+)-K(+)-adenosinetriphosphatase (ATPase) alpha 1-subunit has been shown to be a critical determinant of cardiac glycoside binding. To study the role of this Cys on ion transport activity, we measured pump currents in HeLa cells expressing wild-type or mutant alpha 1-subunit cDNAs. The endogenous ouabainsensitive Na(+)-K(+)-ATPase was selectively inhibited by growing the cells in 0.1 microM ouabain. A Cys-to-Tyr substituted mutant exhibited decreased sensitivity to digitoxin but not digoxin compared with wild type. The decreased affinity for digitoxin was due to a faster dissociation rate. In contrast, the Cys-to-Ala substitution did not significantly alter the sensitivity to digitoxin or digoxin. Both wild-type and mutant cells displayed marked external K(+)-dependent pump currents; however, the affinity for K+ was reduced by the mutations. The decrease in K+ affinity was due to a slower association rate. The results show that the Cys that interacts with cardiac glycosides also participates in the sensitivity of the pump to external K+.

Amino Acid Sequence↗
PubMed1996

Cloning of a gene encoding a putative carbon catabolite repressor from Trichoderma reesei.

We report the cloning and sequencing of a Trichoderma reesei genomic DNA clone that encodes a protein similar to the Aspergillus CREA, a carbon catabolite repressor. The deduced amino acid sequence predicts a zinc finger protein of 402 amino acids in length. The overall amino acid sequence of the T. reesei CREA shows about 52% similarity with Aspergillus CREAs.

Amino Acid Sequence↗
PubMed1996

Long-term results of emergency coronary artery bypass grafting.

During a 20-year period, 364 patients underwent coronary artery bypass grafting (CABG) for the treatment of ischemic heart disease. Among these patients, 28 underwent emergency surgery. The reasons for performing emergency CABG were unstable angina in 15 patients, impending myocardial infarction in 12 patients and congestive heart failure in 1 patient. Eleven patients died postoperatively. Eight variables were examined by univariate analysis for their influence on the occurrence of a hospital death. Lack of a history of myocardial infarction, intraaortic balloon pumping (IABP) and acute coronary occlusion were all found to be predictors of hospital death. Seventeen patients were followed up for 12 years. There was no cardiac death and actuarial survival at 12 years was 63%. The 14 survivors are now in NYHA functional class I or II. Although the operative mortality rate is high after emergency CABG, a fair prognosis can be expected if the patients survive surgery.

Adult↗
PubMed1996

[Surgical correction of total anomalous pulmonary venous drainage: an adult case of successful repair].

Total anomalous pulmonary venous drainage (TAPVD) is a rare congenital cardiac anomaly. It occurs in only 1.5% of children born with congenital heart defects. But, it is one of the most common lesions necessitating intracardiac operation in the neonatal period. We have experienced a 33-year-old man with supracardiac type TAPVD who was operated upon successfully. Cardiac catheterization showed 0.35 in Pp/Ps, 3.33 in Qp/Qs and 0.11 in Rp/Rs. The left to right shunt ratio was 77%, while the right to left shunt ratio was 23%. The operation was composed of anastomosis between the left atrium and the common pulmonary vein, patch closure of the atrial septal defect, ligation of the vertical vein and tricuspid annuloplasty. The posterior approach was adopted in anastomosis between the left atrium and the common pulmonary vein. The association of a normal pulmonary vascular resistance, a large interatrial communication and absence of a pulmonary venous obstruction was considered as factors of a favorable result.

Adult↗
PubMed1996

[Underlying cardiac disease in infective endocarditis].

Underlying cardiac lesions in 39 adult cases with infective endocarditis were studied. 18 cases (46%) of the patients had no evidence of preexisting cardiac disease and infection frequently involved aortic valve. The patients without preexisting cardiac disease and 4 patients with an intracardiac substitute including pacemaker lead and aortic valve prosthesis required a surgery during an active infective endocarditis. All cases of active infective endocarditis accompanied with rheumatic valvular disease underwent surgery after a suppression of active inflammation by medical treatment.

Adult↗
PubMed1996

[Long-term results of emergency coronary artery bypass grafting].

During a 20-year period, 364 patients underwent coronary artery bypass grafting (CABG) for the treatment of ischemic heart disease. Among these patients, 28 underwent emergency surgery. The reasons for performing emergency CABG were unstable angina in 15 patients, impending myocardial infarction in 12 patients, and congestive heart failure in 1 patient. Eleven patients died postoperatively. Eight variables were examined by univariate analysis for their influence on the occurrence of a hospital death. IABP and acute coronary occlusion were found to be predictors of hospital death and previous myocardial infarction was a predictor of hospital survival. Seventeen patients were followed up for 12 years. There was no cardiac death and actuarial survival at 12 years was 63%. The 14 survivors are now in NYHA functional class I or II. Although the operative mortality rate is high after emergency CABG, the patient's prognosis is good.

Adult↗
PubMed1996

[A case of tricuspid and mitral valve replacement for incomplete endocardial cushion defect].

A 56-year-old female who was diagnosed incomplete endocardial cushion defect, underwent closure of ostium primum defect and repair of mitral cleft 2 years ago. Mitral and tricuspid ring annuloplasty was done 9 months after the first operation because of an increment of mitral and tricuspid valve regurgitation. The Third operation, mitral valve replacement by mechanical valve and tricuspid valve replacement by bioprosthetic valve, was performed because of the gradually increased mitral stenosis and tricuspid regurgitation. Post-operative course was uneventful. Resected anterior cusp of mitral and tricuspid valve revealed hypertrophy and shortness macroscopically, and revealed fibrosis and calcification histopathologically. It was considered that remarkable regurgitation was due to secondary change of both valves. We concluded that valve replacement should be performed for case of secondary change of atrioventricular valve in adult patient.

Endocardial Cushion Defects↗
PubMed1996

[Result of surgery for aneurysms of distal aortic arch and proximal descending aorta].

We examined the surgical result for non-dissecting aneurysm of distal aortic arch and proximal descending aorta, for which aneurysm, proximal aortic clamp cannot be set at descending aorta because of the proximal progression of aneurysm. In 25 cases out of all 46 cases for 18 years, before 1990, aortic arch was clamped for proximal aortic control with the aid of temporary bypass, femoral artery-vein bypass or left heart bypass (clamp group). In 10 cases proximal aortic clamp was set between innominate and left common carotid artery and in 15 cases between left common carotid artery and left subclavian artery. In the former, temporary or permanent bypass was made to left common carotid artery. After 1990, in 21 cases, aortic arch was not clamped with the aid of separate cerebral perfusion (no clamp group). In the comparison of surgical result between two groups, no clamp group showed less postoperative complication rate in brain damage (28% vs 14%) and bleeding (16% vs 5%) and showed better operative mortality (20% vs 14%) and better hospital mortality (32% vs 19%). Now, in the surgery for non-dissecting aneurysm of diatal aortic arch and proximal descending aorta, it is preferable not to clamp aortic arc, employing separate cerebral perfusion.

Adult↗
PubMed1996

Influence of downscatter in simultaneously acquired thallium-201/technetium-99m-PYP SPECT.

UNLABELLED: Simultaneously acquired dual-isotope imaging is a unique and useful approach in SPECT. Photon spillover, however, is a potential limitation of this technique. METHODS: To investigate the degree of 99mTc downscatter into the 201Tl window in patients, simultaneously acquired dual-isotope 201Tl/99mTc-pyrophosphate imaging was performed in 17 patients with acute myocardial infarction (MI). Thallium-201 SPECT imaging was performed first, with a 201Tl photopeak window after the 201Tl injection (early 201Tl images), followed by 99mTc injection and SPECT acquisition using dual-isotope windows (dual 201Tl images). Twenty-four hours after the 99mTc injection, a third set of 201Tl images was obtained (24-hr 201Tl images). Thallium defect size (extent score) and defect severity (severity score) were calculated from these three sets of 201Tl images to quantify the MI. RESULTS: Technetium-99m accumulation of varying intensity was recognized in all patients. Extent scores and severity scores were identical in early 201Tl images and 24-hr 201Tl images. Both scores, however, in the dual 201Tl images were decreased by 36% and 53%, respectively. CONCLUSION: There in a considerable 99mTc downscatter into the 201Tl window, which prevents precise quantification of MI in simultaneously acquired dual-isotope 201Tl/99mTc-pyrophosphate imaging.

Female↗
PubMed1996

[Traumatic injuries of the thoracic aorta--report of five cases].

Five cases of traumatic aneurysm of the thoracic aorta associated with blunt chest trauma are described. Although we lost one case, four cases were successfully treated. Case 1, This was a 22-year-old female who underwent surgery for graft replacement of the descending thoracic aorta under extracorporeal circulation two days after injury. Case 2, This was a 17-year-old male who underwent surgery for graft replacement of the descending thoracic aorta under extracorporeal circulation 24 hours after injury. Case 3, This was a 56-year-old female who underwent surgery for graft replacement of the descending thoracic aorta under extracorporeal circulation 24 hours after injury. Case 4, This was a 69-year-old male who underwent surgery for graft replacement with three branches for an aortic arch aneurysm under extracorporeal circulation one month after injury. Despite an emergency operation, we lost case 5 (a 21-year-old male) because of a complete discontinuity of the aortic isthmus. The postoperative course of the other four cases was uneventful. Vessel injury may be more widespread than preoperative radiographic findings demonstrates. Blunt chest trauma is usually accompanied by multisystem injury. Therefore, it is imperative to determine the first priority of treatment based on further preoperative examination in cases having associated injuries.

Adolescent↗