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Biomedical subjects

I Yoshida

Publications and source records attributed to I Yoshida.

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

Determination of the 8-methyl ether of xanthurenic acid in human serum by high-performance liquid chromatography with fluorescence detection.

We developed a simple and sensitive assay for the 8-methyl ether of xanthurenic acid in serum by high-performance liquid chromatography with fluorescence detection (excitation at 340 nm, emission at 450 nm). The compound under study in serum samples was extracted with Sep-Pak C18 cartridge and the extract was applied to an octadecylsilane-bonded column (Nucleosil 5C18, 150 x 4 mm I.D.). The mobile phase used was a mixture of 0.05 M sodium acetate buffer (pH 6.0), containing 5 mM sodium 1-octanesulfonate and 0.1 mM Na2EDTA, and acetonitrile (93:7, v/v). The 8-methyl ether of xanthurenic acid from serum samples was sufficiently separated to be clearly distinguishable. The quantification limit was 2 x 10(-14) mol, which was sensitive enough to detect 8-methyl ether of xanthurenic acid in serum from normal subjects. The method was applied to samples from patients with deficiency in tryptophan metabolism, xanthurenic acid/3-hydroxy kynurenineuria and showed a striking elevation in serum 8-methyl ether of xanthurenic acid.

Amino Acid Metabolism, Inborn Errors↗
PubMed1996

Enhanced expression of beta-adrenergic receptor kinase 1 in the hearts of cardiomyopathic Syrian hamsters, BIO53.58.

We cloned an entire encoding sequence of beta-adrenergic receptor kinase 1 (beta ARK1) cDNA from the hearts of Syrian hamsters through reverse transcription and subsequent polymerase chain reaction. The cloned cDNA contained 2067 nucleotides coding 689 amino acids. The sequence had 95% homology to rat beta ARK1 and 90% homology to human homologue. Cardiomyopathic Syrian hamster, BIO53.58, has been used as a model animal of congestive heart failure. M-mode echocardiography confirmed that left ventricular contractility of 20-week-old BIO53.58 was markedly reduced. The expression of beta ARK1 mRNA in the hearts of BIO53.58 was significantly increased compared to control hamsters, F1b, suggesting that the enhanced beta ARK1 expression is acting as a negative feedback mechanism in order to maintain intracellular homeostasis against accelerated stimulation by catecholamines via phosphorylation of beta-adrenergic receptor.

Aging↗
PubMed1996

Use of ultrasound-guided percutaneous needle biopsy in the diagnosis of mediastinal tumors.

We herein report the usefulness of ultrasound-guided percutaneous needle biopsy for histological diagnosis in 18 patients with mediastinal tumors. Computed tomography revealed these tumors to be in contact with the chest wall. The preoperative diagnosis was thymoma in 7 patients, germinoma in 5, neurogenic tumor in 3, and "other" in 3. The most commonly encountered indication for an ultrasound-guided percutaneous needle biopsy was an anterior mediastinal lesion (78%; 14 of 18 patients). In 16 (89%) of the 18 patients, the biopsy diagnosis corresponded to the postoperative diagnosis. No complications were encountered in any of the patients. This new technique of ultrasound-guided percutaneous needle biopsy is both relatively simple and highly accurate and may thus be useful for outpatients. Preoperative ultrasound-guided percutaneous needle biopsy is thus considered to be a safe and reliable method for the histological diagnosis of mediastinal tumors, and a good alternative to traditional biopsy techniques such as mediastinoscopy or thoracotomy.

Adolescent↗
PubMed1996

Successful treatment of Wolff-Parkinson-White syndrome with concomitant mitral stenosis by simultaneous surgery.

We report the case of a 61-year-old man with type B Wolff-Parkinson-White (WPW) syndrome associated with a right atrioventricular (AV) accessory pathway and concomitant mitral stenosis, who underwent successful operative treatment by simultaneous surgery. His preoperative course had been characterized by cardiac failure and repeated episodes of atrial tachyarrhythmia, in the form of fibrillation and flutter, which were difficult to control by conventional medication. Preoperative electrocardiograms (ECGs) had suggested that the accessory pathway was located in the right posterior to posteroseptal wall; however, at the time of surgery, epicardial electrophysiological mapping with sock electrodes revealed a preexcitation area in the AV groove at the lateral right margin of the heart. This discrepancy was thought to have been due to the presence of mitral stenosis or multiple accessory pathways. Thus, division and cryoablation of the accessory pathway by an endocardial approach, in addition to mitral valve replacement, were performed under cardiopulmonary bypass. His postoperative course was uneventful, and subsequent ECGs revealed that the delta waves had disappeared. The successful outcome of this patient demonstrates the effectiveness of simultaneous surgery for WPW syndrome associated with valvular disease.

Atrial Fibrillation↗
PubMed1996

A malignant Triton tumor in the anterior mediastinum requiring emergency surgery: report of a case.

We report herein the case of a 17-year-old woman with von Recklinghausen's disease who was diagnosed as having a giant malignant Triton tumor located in the anterior mediastinum, which had adhered to the heart and the great vessels. An emergency operation was performed to relieve the tracheobronchial stenosis and congestive heart failure caused by the pressure of the tumor. Extracorporeal circulation was not required and the tumor could be excised only piece by piece. To our knowledge, this is the first report of a malignant Triton tumor being located in the anterior mediastinum.

Adolescent↗
PubMed1996

A point mutation in exon 3 (His 107-->Tyr) in two unrelated Japanese patients with carbonic anhydrase II deficiency with central nervous system involvement.

We have analyzed two unrelated Japanese patients with carbonic anhydrase II deficiency born to consanguineous parents. We have identified the same mutation as that reported to be homozygous in a Belgian family and compound heterozygous in an American family. It comprises to C-to-T transition that results in the amino acid substitution of Tyr (TAT) for His (CAT) at position 107. This point mutation creates an AccI site that can be conveniently screened by the polymerase chain reaction/restriction fragment length polymorphism method using a restriction enzyme for gene tracking. Our patients exhibit severe mental retardation, not seen in the Belgian and American patients.

Carbonic Anhydrases↗
PubMed1996

Preoperative intra-arterial infusion chemotherapy for invasive thymoma: a case report.

A 24-year-old man was diagnosed as having mixed-type thymoma by preoperative percutaneous needle biopsy. A chest computed tomogram showed a tumor measuring 12x9 cm. Selective intra-arterial infusion chemotherapy was first selected because invasion to the superior vena cava was suspected. Bolus injection of 50 mg/m2 cisplatin and 20 mg/m2 adriamycin was performed once into the right internal thoracic artery. The resulting decrease in tumor size was 81%. Neither complications due to the infusion procedure nor side effects due to the anticancer drugs were encountered. An extended thymectomy with partial resection of the mediastinal pleura was safely performed. The histological diagnosis of the resected tumor was thymic hyperplasia. The patient was transferred to a radiologist for additional radiotherapy. Selective intra-arterial infusion chemotherapy for invasive thymoma is an effective therapy, producing no significant side effects and allowing safe resection.

Adult↗
PubMed1996

Sweet syndrome in a child with aplastic anemia receiving recombinant granulocyte colony-stimulating factor.

PURPOSE: To elucidate the pathogenesis of Sweet syndrome, one patient with aplastic anemia was evaluated. PATIENT AND METHODS: A 15-year-old girl presented with intermittent fever and progressive pallor for 3 months after non-A, non-B, non-C hepatitis. Aplastic anemia was diagnosed and therapy was begun with recombinant granulocyte colony-stimulating factor (G-CSF), methylprednisolone pulse therapy, antilymphocyte globulin and cyclosporin A. There was only an increase in the neutrophil counts. We continued G-CSF therapy of 300 micrograms/m2 on alternate days for 7 months. At this time the white blood cell count was 10,000/microliters and the patient developed high-grade fever and a painful, erythematous, tender plaque (3 X 3 cm) on the left thigh. We diagnosed the lesion as a skin infection and stopped G-CSF therapy and started antibiotics. Cultures were negative. The lesion slowly resolved, G-CSF was restarted after 2 months, and 1 month later disseminated lesions occurred. Antibiotic therapy was not effective. RESULTS: Biopsy of the lesion demonstrated infiltration of the dermis by sheets of neutrophils. We stopped G-CSF and began corticosteroid therapy. The skin lesions resolved rapidly. CONCLUSION: We postulated that Sweet syndrome was induced by G-CSF treatment.

Adolescent↗
PubMed1996

Family history-related risk of gastric cancer in Japan: a hospital-based case-control study.

In Japan, there have been a few reports on the familiar factors of gastric cancer (GC) and on the GC risk related to family history (FH) at other cancer sites. We analyzed the association between GC occurrence and a positive FH of cancer of the stomach and of other sites in a hospital-based case-control study. The subjects included cases histologically confirmed as incident cancer of the stomach (n = 136; 86 male and 50 female patients) and sex and age (+/- 1 year)-matched controls. GC risk was high when a subject had a parental history of GC [Mantel-Haenszel odds ratio adjusted for sex and age (OR)=2.3; 95% confidence interval (95% CI):1.1-5.0]. GC risk was almost unity for a cancer FH of any other cancer site, even among closer relatives, suggesting little or no contribution to GC occurrence. The familial occurrence of GC found in this study suggests the existence of a genetic susceptibility to cancer of the stomach. Further, females tended to show higher GC risks than males, when reporting an affected mother (OR=6.0; 95% CI:1.1-31.4 and OR= 1.4; 95% CI:0.4-4.8, respectively), whereas males showed a slightly higher risk than females when reporting an affected father (OR=2.4; 95% CI:0.8-7.5 and OR=2.3; 95% CI:0.4-15.6, respectively). This suggests a possible gender difference in how environmental factors influence GC occurrence. The development of gastric tumors seems to be due to a complex and unknown interaction between environmental and genetic factors.

Aged↗
PubMed1996

Analysis of phosphorylation pathways of antiherpesvirus nucleosides by varicella-zoster virus-specific enzymes.

The inhibitory activities of acyclovir (ACV), 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (BV-araU), ganciclovir (GCV), 9-(2-deoxy-2-hydroxymethyl-beta-D-erythro-oxetanosyl)guanine (OXT-G), and (+)-9-[(1R,2R,3S)-2,3-bis(hydroxymethyl)Cyclobutyl]guanine (cOXT-G) on the replication of wild-type and thymidine kinase (TK)-negative strains of herpes simplex virus types 1 and 2 and varicella-zoster virus (VZV) and the wild-type strain of human cytomegalovirus were tested to clarity whether the phosphorylation of these compounds is catalyzed by viral TK or other enzymes. ACV and BV-araU had little effect on the replication of TK-negative virus strains. On the other hand, GCV, OXT-G, and cOXT-G inhibited the replication of TK-negative VZV at concentrations 10 times higher than those at which they inhibited wild-type VZV, indicating that a kinase other than TK phosphorylates GCV and OXT-G in VZV-infected cells. GCV phosphorylation activity was not detected in VZV-infected cell lysates; therefore, this activity was evaluated in COS 1 cells expressing viral TK and viral protein kinase (PK). The COS 1 cells expressing VZV TK were shown to be susceptible to all compounds tested. In contrast, VZV Pk-expressing COS 1 cells were susceptible to only GCV, OXT-G, and cOXT-G. These results suggest that VZV PK phosphorylates some nucleoside analogs, for example, GCV, OXT-G, and cOXT-G. This phosphorylation pathway may be important in the anti-VZV activities of some nucleoside analogs.

Acyclovir↗
PubMed1996

Relationship of the strain and the intraocular amount of herpes simplex virus types 1 and 2 in the induction of anterior-chamber-associated immune deviation.

We investigated the induction of anterior-chamber-associated immune deviation (ACAID) by herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). Two strains of HSV-1 (VR-3 and F) and four strains of HSV-2 (UW-268, 186, SL, and MS) were inactivated with ultraviolet light, and the anterior chamber of BALB/c mice was inoculated with a viral strain. Immunization against delayed-type hypersensitivity (DTH) was done subcutaneously on day 7 after anterior chamber inoculation. On day 10 after DTH immunization, each virus was inoculated into the foot pad. DTH was evaluated by measuring the foot pad thickness at 24 h after the inoculation into the foot pad. DTH was suppressed by anterior chamber inoculation with more than 10(3) plaque-forming units (PFU) of the VR-3, UW-268, 186, and SL strains, and with 10(5) PFU of the F strain, but not by the MS strain. Until now, HSV-2 was believed not to induce ACAID, however, our results indicate that some HSV-2 strains induce ACAID.ACAID induction by HSV-1 and HSV-2 may depend on both the viral strain and the amount of ocular viral antigen.

Animals↗
PubMed1996

Polysaccharides in fungi. XXXVII. Immunomodulating activities of carboxymethylated derivatives of linear (1-->3)-alpha-D-glucans extracted from the fruiting bodies of Agrocybe cylindracea and Amanita muscaria.

Immunomodulating activities of three carboxymethylated derivatives (AG-AL-CMS, AG-AL-CMI, and AM-APP-CM) of linear (1-->3)-alpha-D-glucans from Agrocybe cylindracea and Amanita muscaria were evaluated with murine peritoneal macrophages playing an important role in tumor immunity. The ratio of macrophages in peritoneal exudate cells increased more than 50% after the administration of three carboxymethylated (1-->3)-alpha-D-glucans. These carboxymethylated (1-->3)-alpha-D-glucans exhibited higher potentiating activities for macrophages than carboxymethylated linear (1-->3)-beta-D-glucan (CMPS) in the potency of reduction of nitro blue tetrazolium, products of nitric oxide and the soluble cytotoxic factor, the amount of glucose consumption, and the activation of acid phosphatase. AG-AL-CMS, AG-AL-CMI, and AM-APP-CM were found to induce the tumor regressing factor in mouse serum, although the ability of the induction of this factor was weaker than that of CMPS. The reticuloendothelial system-potentiating activation of three carboxymethylated alpha-D-glucans was similar to that of the carboxymethylated beta-D-glucan. AG-AL-CMS and AG-AL-CMI, but not AM-APP-CM, were suggested to possess a higher-order structure, resulting from the formation of a fluorescent complex with aniline blue.

Acid Phosphatase↗
PubMed1996

A case of adenosine-sensitive ventricular tachycardia in a very elderly male.

The best-known type of adenosine-sensitive ventricular tachycardia is idiopathic and of right ventricular outflow origin; however, there is little information about other types of adenosine-sensitive ventricular tachycardia. Idiopathic adenosine-sensitive ventricular tachycardia is common in the young. An 87-year-old man with ventricular tachycardia was admitted to our hospital. His ventricular tachycardia was sensitive to adenosine triphosphate, edrophonium, verapamil, and Valsalva's maneuver. He had experienced no anginal episodes. His ventricular tachycardia was thought to be idiopathic. We report this very rare case of adenosine-sensitive ventricular tachycardia, which was not derived from the right ventricular outflow tract, in a very elderly male.

Adenosine↗
PubMed1996

Changes in clinical features of fungemia in a Japanese University Hospital over a 12-year period.

Forty-five patients with fungemia during 1982-1993 (periods I = 1982, II = 1986-1989, III = 1990-1993) in a Japanese university hospital were reviewed to follow changes in the clinical features of fungemia. The percentage of fungi among microorganisms isolated from blood cultures was almost constant (6-10%) throughout the study period. Fungemia was highly associated with use of intravascular catheters, and some changes in clinical features were observed: 1) Candida albicans, C. parapsilosis and C. glabrata were the main isolates, and the number of fungal species showed a tendency to increase. 2) The percentage of patients over 65 years old increased from 36 to 50%. 3) The percentage of patients who were treated with anti-fungal agents and/or removal of catheter increased from 50 to 89 and to 86%. 4) The percentage of patients who died within 28 days after isolation of fungus decreased from 64 to 27%. The improved prognosis was thought to be due to the development of new anti-fungal agents and faster removal of intravascular catheter when infection was suspected.

Adolescent↗
PubMed1996

[A course of pirarubicin vesical irrigation at thirty mg effectively prevents post-TUR recurrence of superficial bladder cancer].

In order to study its safety and anti-cancer dose-effectiveness in the prevention of cancer recurrence, two groups of patients having superficial bladder cancer (TUR-Bt) had their bladder intravesically irrigated post-surgically with 20 or 30 mg aliquots of (2''R)-4'-0-tetrahydropyranyl-adriamycin (THP). A total of 74 patients with bladder cancer were entered in the study. Four cases proved ineligible, and 30 could not complete the planned treatment. THP vesical irrigation of 14-17 sessions was regarded as a condition for eligibility: Clinical evaluation was feasible with 19 patients of 20 mg and 21 of 30 mg THP. Non-recurrence rates at 1, 2, 3 and 4 years were 89.5, 53.3, and 26.6%, respectively, for the 20 mg group, and 95.2, 84.3, 75.9 and 75.9%, respectively, for the 30 mg THP group. The incidence of side effects appeared slightly greater in the 30 mg THP group than in the 20 mg group, and there were no systemic adverse reactions. Topical reaction of cystitis was noted to be as low as 12.5%. Thus, THP vesical irrigations at 30 mg were found tolerable and effective for the prevention of local recurrence following TUR-Bt.

Administration, Intravesical↗