Search PubMed⌕ Search

Biomedical subjects

Y Sakai

Publications and source records attributed to Y Sakai.

At least 253 records · Page 14Linked to original sources
PubMed1999

Sendai virus gene start signals are not equivalent in reinitiation capacity: moderation at the fusion protein gene.

In paramyxovirus transcription, viral RNA polymerase synthesizes each monocistronic mRNA by recognizing the gene start (S) and end (E) signals flanking each gene. These signal sequences are well conserved in the virus family; nevertheless, they do exhibit some variations even within a virus species. In Sendai virus (SeV) Z strain, the E signals are identical for all six genes but there are four (N, P/M/HN, F, and L) different S signals with one or two nucleotide variations. The significance of these variations for in vitro and in vivo replication has been unknown. We addressed this issue by SeV reverse genetics. The luciferase gene was placed between the N and P gene so that recombinant SeVs expressed luciferase under the control of each of the four different S signals. The S signal for the F gene was found to drive a lower level of transcription than that of the other three, which exhibited comparable reinitiation capacities. The polar attenuation of SeV transcription thus appeared to be not linear but biphasic. Then, a mutant SeV whose F gene S signal was replaced with that used for the P, M, and HN genes was created, and its replication capability was examined. The mutant produced a larger amount of F protein and downstream gene-encoded proteins and replicated faster than wild-type SeV in cultured cells and in embryonated eggs. Compared with the wild type, the mutant virus also replicated faster in mice and was more virulent, requiring a dose 20 times lower to kill 50% of mice. On the other hand, the unique F start sequence as well as the other start sequences are perfectly conserved in all SeV isolates sequenced to date, including highly virulent fresh isolates as well as egg-adapted strains, with a virulence several magnitudes lower than that of the fresh isolates. This moderation of transcription at the F gene may therefore be relevant to viral fitness in nature.

Animals↗
PubMed1999

Prognostic significance of the pattern of multivessel spasm in patients with variant angina.

Multivessel spasm in variant angina is believed to be a major prognostic factor. Three patterns of multivessel spasm have been detected: (1) spasm at different sites on different occasions (migratory spasm); (2) spasm sequentially affecting 2 different sites (sequential spasm); and (3) simultaneous spasm at more than 1 site (simultaneous spasm). The present study investigated the prognosis based on this factor for variant angina without fixed coronary stenosis and examined the influence of multivessel spasm on cardiac events. Twenty-six patients were diagnosed as having variant angina without fixed coronary stenosis using 12-lead 24-h ECG recording system and coronary cineangiography. These patients were followed up prospectively for 57.1+/-7.6 months. Of the 26 patients 13 had single-vessel spasm, 6 had migratory multivessel spasm angina, and 7 showed sequential and/or simultaneous multivessel spasm angina. The survival free of serious cardiac events and of all cardiac events was significantly lower for patients with sequential and/or simultaneous multivessel spasm than for those with migratory multivessel spasm (p<0.05, p<0.05), whereas for patients with migratory multivessel spasm the difference comparison with single-vessel spasm did not attain statistical significance (p = ns, p = ns). The results of this study suggest that there seems to be a high-risk subgroup (i.e., sequential and/or simultaneous multivessel spasm) among patients with variant angina.

Aged↗
PubMed1999

Dynamic outflow obstruction due to the transient extensive left ventricular wall motion abnormalities caused by acute myocarditis in a patient with hypertrophic cardiomyopathy: reduction in ventricular afterload by disopyramide.

A 65-year-old woman was admitted to the coronary care unit because of acute pulmonary edema. Immediate 2-dimensional and Doppler echocardiograms revealed extensive left ventricular wall motion abnormalities and left ventricular hypertrophy with extreme outflow obstruction. Although an ECG showed ST-segment elevation in the anterolateral leads, a coronary arteriogram revealed normal epicardial arteries. Heart failure was relieved after diminishing the dynamic outflow obstruction with disopyramide administration. An endomyocardial biopsy from the right ventricle on the 8th hospital day showed borderline myocarditis. Wall motion abnormalities gradually normalized within 2 weeks. It is speculated that her pulmonary edema would not have been relieved so readily without the immediate reduction in ventricular afterload by disopyramide. These clinical changes over time were observed with serial echo-Doppler examinations.

Acute Disease↗
PubMed1999

Dual-chamber pacing in hypertrophic obstructive cardiomyopathy: a comparison of acute and chronic effects.

This study describes the acute and chronic effects of dual-chamber (DDD) pacing in 14 consecutive patients with hypertrophic obstructive cardiomyopathy (HOCM), whose symptoms were refractory to drug therapy. Although left ventricular (LV) outflow tract pressure gradients diminished from 106+/-47 to 62+/-33 mm Hg (p<0.001) by temporary pacing, the residual pressure gradients were >30 mm Hg in the majority of those with concomitant reductions in cardiac output. The DDD pacing was judged as insufficient by the acute study in the majority of patients. A dual-chamber pacemaker was, however, implanted in 11 patients, and the chronic pacing effects were evaluated. All symptoms (syncope, fainting, palpitation and dyspnea) subsided within 1 month. Left ventricular outflow tract pressure gradients diminished from 99+/-56 to 21+/-13 mm Hg (p<0.004) at 1 week after, and to 17+/-12 mm Hg (p<0.002) at 1 year after the implantation, as measured by Doppler echocardiography. Echocardiogram showed disappearance of the systolic anterior motion of the mitral valve, and significant regression of the septal hypertrophy (from 18.5+/-4.3 to 15.7+/-4.1 mm, p<0.04). There was no significant correlation between the acute and chronic pacing effects in the reduction of the pressure gradients or symptomatic improvement. These results suggest that DDD pacemaker implantation is an effective treatment without any serious risks for patients with drug-refractory HOCM. The chronic-pacing effect in the reduction of the pressure gradient, the regression of hypertrophy and symptomatic improvement cannot be predicted by the assessment of temporary DDD pacing.

Adult↗
PubMed1999

A new carboxylesterase from Brevibacterium linens IFO 12171 responsible for the conversion of 1,4-butanediol diacrylate to 4-hydroxybutyl acrylate: purification, characterization, gene cloning, and gene expression in Escherichia coli.

A carboxylesterase that is responsible for conversion of 1,4-butanediol diacrylate (BDA) to 4-hydroxybutyl acrylate (4HBA) was found in Brevibacterium lines IFO 12171, and purified to homogeneity. The purified enzyme was active toward a variety of diesters of ethylene glycol, 1,4-butanediol, and 1,6-hexanediol. The K(m) and kcat of the enzyme for BDA were 3.04 mM and 203,000 s-1, respectively. The reaction with the purified enzyme gave 98 mM 4HBA from 100 mM BDA for 60 min. The enzyme gene was cloned from the chromosomal DNA of the bacterium. The open reading frame encoding the enzyme was 1176 bp long, corresponding to a protein of 393 amino acid residues (molecular mass = 42,569 Da). The deduced amino acid sequence contained the tetra peptide motif sequence, STTK, and the serine residue was confirmed to be the catalytic center of BDA esterase by site-directed mutagenesis for several amino acid residues. The gene was expressed in Escherichia coli under the control of the lac promoter, and the gene product (a fusion protein with 6 amino acid residues from beta-galactosidase) showed the same catalytic properties as the enzyme from the parent strain.

Acrylates↗
PubMed1999

Cyclic bursts of ventricular premature contractions of more than one minute intervals.

Ventricular premature contractions (VPCs) occasionally appear successively in the form of bigeminy, trigeminy or quadrigeminy associated with quiescent periods. However, details of these rhythmic VPC bursts have not been well documented. We analyzed the incidence, periodicity and interval of VPC bursts exhibiting bigeminy or trigeminy using ambulatory ECG monitoring and computer analysis. We defined VPC bursts as more than 5 successive groups of VPCs each containing more than 20 VPCs in the form of bigeminy or trigeminy that were interrupted by normal sinus rhythm lasting for more than 60 seconds. Bursts thus defined were observed transiently or continuously in 78 out of 500 consecutive patients showing > 3000 VPCs a day. Their age ranged from 14 to 76 years (mean 48). Forty patients were men and 38 were women. We could discriminate between two types of bursts on the instantaneous heart rate tachograms. Dome type bursts (n = 48) showed gradual shortening of the VPC coupling intervals whereas horizontal type bursts (n = 30) demonstrated fixed coupling intervals during the bursts. Cycle length of the dome type burst was 185 +/- 40 seconds and regular, whereas it was 210 +/- 63 seconds and irregular in the horizontal type (NS). Duration of the VPC bursts was 101 +/- 31 seconds in the dome type and 98 +/- 41 seconds in the horizontal type. Both burst types were associated with transient increases in sinus rate and abbreviated VPC-VPC intervals. We suspect ventricular parasystole to be the mechanism of these bursts especially in the dome type. Recognition of these two burst types from heart rate tachograms may be of value in the suppression of VPCs.

Adolescent↗
PubMed1999

[Bladder dysfunction in dementia patients showing urinary incontinence: evaluation with cystometry and treatment with propiverine hydrochloride].

In a total of 46 dementia patients with urinary incontinence, filling cystometry was performed to evaluate bladder function, followed by peroral administration of propiverine hydrochloride. Therapeutic effects were evaluated in terms of changes in cystometric bladder capacity and urinary incontinence. Based on cystometric findings, 58.1%, 35.3% and 6.4% of Alzheimer dementia patients proved to have overactive bladder, normoactive bladder and low compliant bladder, respectively. Similarly, 90.9% and 9.1% of vascular dementia patients had overactive detrusor and low compliance, respectively. As a result of propiverine hydrochloride administration for 2 weeks, both bladder capacity and incontinence improved in around 40%, irrespective of the dementia type (Alzheimer vs vascular). It is of interest, however, that patients with overactive bladder demonstrated more satisfactory response to the treatment than those with normoactive bladder. It is accordingly suggested that propiveline hydrochrolide is a promising treatment option for urinary incontinence in demented elderly and cystometry could be useful in predicting treatment outcome.

Aged↗
PubMed1999

[Aggressive angiomyxoma in the scrotum: a case report].

A case of aggressive angiomyxoma occurring in the scrotum is reported. A 57-year-old Japanese man presented with a 2-year history of non-tender soft mass in the scrotum. Computed tomography and magnetic resonance imaging revealed a well-defined mass 8 cm in diameter extending from the medial aspect of the left ischium. Angiography revealed faint vascularity fed by the left internal pudendal artery. Excision was performed by a scrotal approach, and histological examination confirmed an aggressive angiomyxoma. The patient showed no recurrence at 3 months follow-up.

Female↗
PubMed1999

[A case of idiopathic retroperitoneal fibrosis with renal subcapsular urinoma resolved by steroid therapy].

A case of idiopathic retroperitoneal fibrosis is reported. The patient was a 63-year-old man with the complaint of right flank pain, general fatigue and weight loss. Intravenous pyelography revealed right hydronephrosis and peripelvic extravasation. Abdominal computed tomography showed subcapsular urinoma of the right kidney and mass lesion surrounding the aortic bifurcation. Retrograde pyelography demonstrated a narrow segment at the middle portion of the right ureter through which the ureteral catheter could be easily passed. Magnetic resonance imaging showed a low-intensity mass on T1 weighted images and a heterogeneous mass on T2 weighted images. Steroid therapy was selected under the diagnosis of idiopathic retroperitoneal fibrosis with subcapsular urinoma of the right kidney. Prednisolone was administered for 60 days, resulting in the complete disappearance of the urinoma.

Anti-Inflammatory Agents↗
PubMed1999

[Anesthesia in a patient with epidermolysis bullosa].

Epidermolysis bullosa hereditaria, a rare inherited disorder presents clinically with recurrent cutaneous blister formation with possible involvement of mucous membrane and organs following minimal trauma. The sequelae of this disease pose significant anesthetic problems to operating room staffs. We describe the anesthetic management of a 32-year old woman with epidermolysis bullosa hereditaria who underwent palmar skin graft using regional anesthesia, and discuss the problems associated with this disease.

Adult↗
PubMed1999

[The analysis for surgical procedures of coronary-artery bypass grafting: selection of graft materials].

We analyzed 222 patients undergoing coronary artery bypass grafting (CABG) in our institute. Our selection of graft materials consists of only one arterial conduit and one or more saphenous vein grafts (SVG). An arterial conduits (left internal thoracic artery (LITA) was mainly used for the left anterior descending coronary artery (LAD), while a SVG was used for coronary arterial branch. Our approach was evaluated by the mid-term prognosis as well as cardiac events. Seventy-one percent of patients with CABG could be followed. The graft patency rate was better for ITA grafts than for SVG (97.8% vs 88%). The incidence of late cardiac events was lower in patients with the LITA, to the LAD. Furthermore, these patients had a better survival rate at 4 years comparing with patients who had vein bypass grafts alone. We suggest that this selection of graft materials may be accepted in CABG for the good quality, avoiding the cardiac events.

Adult↗
PubMed1999

Transaortic approach for a closure of a residual ventricular septal defect of the tetralogy of Fallot.

BACKGROUND: A residual ventricular septal defect as part of the tetralogy of Fallot (TOF) is often difficult to close when a long interval has elapsed after a radical operation or the position of the defect is problematic. METHODS: When an accurate diagnosis and closure of a residual ventricular septal defect (VSD) were not obtainable through right atriotomy and right ventriculotomy, the ascending aorta was opened. The smooth surface of the left ventricular septum makes it possible to find the position of the defect, and close it accurately and safely. RESULTS: Three consecutive patients were operated upon using this method. They had undergone repair of tetralogy of Fallot anomalies 8 years, 26 years, and 21 years prior to this surgery, respectively. All patients survived the operation and were discharged from the hospital. None of the patients had residual defects, aortic regurgitation, or new atrioventricular block. CONCLUSIONS: This transaortic approach for closing residual ventricular septal defects related to the tetralogy of Fallot offers an alternate method when either the right atrial or right ventricular approach cannot be performed successfully. This approach may make it possible to close such defects directly.

Adult↗
PubMed1999

[Diagnosis of ulcerative colitis--barium enema examination].

Barium enema is useful especially for differential diagnosis of right sided type or segmental type of ulcerative colitis from other inflammatory bowel diseases. Compared with endoscopical examination, it provides more objective informations about the range of affected colon which is necessary for the choice of treatment strategy to the reluctant case. However, as preparation procedures may cause aggravation of ulcerative colitis, an unnecessary barium study should be avoided. Even the case in remission stage, it is advisable to add 40 to 60 mg of water-soluble predonisolone to barium solution. Roentogenographic diagnosis of ulcerative colitis is not difficult, in so far as two major points are properly evaluated. The first is the presence or absence of haustration, and the second is mucosal surface of the colon, namely, multiple ulcers or erosions distributing diffusely and continuously in active stage, or granular mucosa and disarray of network pattern of colonic mucosa in remission stage.

Barium Sulfate↗
PubMed1999

[Nutritional therapy for ulcerative colitis].

Despite its supplementary role for a remedy of the Ulcerative Colitis, nutritional therapy performs the important role as well as medicine. In the active state, the aim of nutrition therapy is to reduce the activity of the disease. In the remission state, the aim is to keep the condition and to supply elements of nutrition which the disease causes these deficiency such as vitamins or minerals. Needless to say, it is required to consider a few points; patient's condition, lesion's digestion disorder and leakage, or side effects of caused by medicines. High calorie, low fat and rich protein is ideal for the nutrition therapy for this disease, however it is suggested to satisfy patient's mental health at the same time. Nutrition therapy for Ulcerative Colitis should be regarded as the long-term treatment that requires the co-operation and comprehension between patients and medical supporting staffs.

Colitis, Ulcerative↗
PubMed1999

[Treatment of mild and moderate ulcerative colitis].

Selection of treatment for ulcerative colitis is based on the definition of clinical severity. In those medication is a main course. Mild and moderate cases are treated mainly with salicylazosulfapyridine or mesalazine. Patients with proctitis-type are added betamethazone suppositories and those with left-sided and total colitis-type predonisolone enema therapy simultaneously. If there is no response, they are given additional oral predonisolone. Even after remission, patients should be carefully observed. A good patient-physician relationship, continuation of maintenance therapy, and periodic follow-up examinations using colonoscopy or barium enema are essential to successful long-term management of this disease. Patients who have repeated relapsing should receive the stronger treatment, according to the endoscopic findings and clinical course in addition to the clinical severity.

Anti-Inflammatory Agents↗