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Biomedical subjects

Y Ohta

Publications and source records attributed to Y Ohta.

At least 469 records · Page 26Linked to original sources
PubMed1995

[Clinical characteristics and outcome of 508 patients with hyperventilation syndrome].

The characteristics of hyperventilation syndrome (HVS) were studied in 508 patients who visited our hospital over 11 years. Information regarding symptoms and laboratory data was collected from the clinical records, and outcome was surveyed with a questionnaire mailed to all patients. Patients with acute HVS ranged in age from 5-85 years, and acute HVS was particularly prevalent among women in their late teens. Triggers of HVS included anxiety, nausea & vomiting, and fever due to the common cold. The primary symptoms were dyspnea and numbness, but these differed from the symptoms that appeared during a provoked attack, Half of the patients had no underlying disorder, but the others were suffering from neurosis, cardiovascular disorders, or other diseases. These characteristics of acute HVS did not differ from those seen in patients in whom the diagnosis of HVS was confirmed with arterial blood gas analysis. Half of the patients recovered without treatment, and the others underwent paper-bag rebreathing or intravenous infusion of sedatives. The prevalence of chronic HVS was 2% and almost all those patients were middle-aged women. In contrast, the questionnaire revealed that half of the patients had repeated HVS attacks. In 10% of the patients, these attacks persisted for more than 3 years. Many of these patients reported that they sighed frequently and felt air hunger while in remission. These findings were compatible with the criteria for chronic HVS. Therefore, it may be possible to diagnose HVS from symptoms alone, without hyperventilation provocation tests. In conclusion, these data underscore the importance of clinical symptoms in the diagnosis of HVS.

Adolescent↗
PubMed1995

[Histological evaluation of lung cancer with T2-weighted magnetic resonance images].

We investigated the differences in signal intensity of lung cancer tissue and non-cancerous lung tissues on T2-weighted magnetic resonance (MR) images. MR images were obtained from patients with squamous cell carcinoma (n = 6), adenocarcinoma (n = 5), small cell carcinoma (n = 5), and large cell carcinoma (n = 1). To compare the MR signal intensity between tissues, we calculated the signal intensity ratios for tumor/skeletal muscle and lung/skeletal muscle. The MR signal intensity for each tissue was measured with a densitometer and T2-weighted MR images with a similar window and a center. The value of the signal intensity ratio for squamous cell carcinoma (3.26 +/- 0.76) was greater than those for adenocarcinoma (1.99 +/- 0.50, p < 0.05), small cell carcinoma (2.35 +/- 0.60), large cell carcinoma (2.46), and non-cancerous lung tissues (1.70 +/- 0.68, p < 0.02). The values of the MR signal intensity ratio for non-cancerous lung tissues were 2.00 for a collapsed lung, 0.93 for a firotic lung, and 2.18 for a fibrotic lung with obstructive pneumonia. The results suggest that the MR signal intensity ratio for pathologic tissues/normal skeletal muscle can be a useful indicator for qualitative and quantitative MR imaging diagnosis.

Adenocarcinoma↗
PubMed1995

[Percutaneous placement of intraluminal stent-graft for aortic dissection: experimental study].

Highly porous fabric vascular grafts fabricated of ultrafine polyester fibers (UFPF-graft; porosity, 7,000 ml, 9,000 ml, 11,000 ml at 120 mmHg) were attached between two Gianturco stents connected with two stainless steel struts. UFPF-grafts with two Gianturco stents were placed into the aortas of six adult mongrel dogs without firm contact with the luminal surface. From two days to four months after placement, all the UFPF-grafts were completely sealed with fresh thrombus or neointima. Within two months, complete endothelialization was observed on both surfaces of the neointima. In three dogs, aortic dissections were created experimentally. Then an UFPF-graft (porosity, 9,000 ml) with two Gianturco stents was placed at the site of entry of the dissection, followed by additional Gianturco stents to expand the UFPF-graft. X-ray angiography showed that the entries were closed immediately after placement, and false lumens disappeared within one hour after placement. These results indicated that the method has the possibility of treating aortic dissection with complete sealing of the fabric by the neointima.

Aortic Dissection↗
PubMed1995

Regional medical information network using optical memory cards and integrated services for digital network.

Since 1986, we have been developing a regional health and welfare system using optical memory cards. We have expanded the system and performed model experiments and evaluations this time. There are approximately 3000 card-holders and 23 card-reader terminals in use. They cover 50 percent of the medical facilities in the city of Isehara. Two medical clinics within neighboring cities have joined our project. Standard Deviation Index (SDI) has been introduced to standardize the numeric results of examinations. The terminals are connected with Integrated Services for Digital Network (ISDN) allowing remote access to the optical memory cards. This enhanced connectivity has allowed greater cooperation in delivering quality medical services.

Aged↗
PubMed1995

Comparison of carboplatin/etoposide/vincristine with cisplatin/etoposide as combination chemotherapy for small cell lung cancer.

We compared the efficacy and toxicity of the CEV regimen (carboplatin at 300 mg/m2 on day 1, etoposide at 100 mg/body on days 1 to 3, and vincristine at 1 mg/m2 on days 1 and 8) with the PVP regimen (cisplatin at 80 mg/m2 on day 1 and etoposide at 100 mg/body on days 1 to 3) in patients with untreated small cell lung cancer (SCLC). Of the 13 patients treated with the PVP regimen, two achieved complete response (CR, 15.4%) and eight partial response (RP, 61.5%). Of the 15 evaluable patients treated with the CEV regimen, one achieved CR (6.7%) and 13 PR (86.7%). Thus, there was no significant difference in response rate between the PVP (76.9%) and CEV (93.3%) regimens. There was also no significant difference in response duration [PVP, 756 +/- 903 (mean +/- SD) days vs. CEV, 318 +/- 159 days] and median survival time (PVP, 472 days, vs. CEV, 471 days). The number of days hospitalized divided by the duration of chemotherapy was shorter with the CEV regimen, but this difference was not statistically significant. Severe leukopenia (< 2,000/microliter) occurred in 15.4% of PVP patients and 31.3% of CEV patients. Severe thrombocytopenia (< 50,000/microliter) occurred in only one patient in this study. In conclusion, the CEV regimen demonstrated a response rate and median survival time comparable to the PVP regimen, although the response time was short. The CEV regimen had the advantage of lower toxicity and ease of outpatient administration. Thus, the CEV regimen is a useful outpatient induction chemotherapy for SCLC.

Antineoplastic Agents↗
PubMed1994

[The effect of antiandrogen TZP-4238 on corticosteroid hormone in the dog].

We studied the adrenosuppressive effect of antiandrogen TZP-4238 and its metabolites. The binding affinity for the corticosteroid receptor using rat hepatic cytosol was in the order 11-OH TZP-4238 > 11, 15-(OH)2 TZP-4238 >> TZP-4238 > or = 15-OH TZP-4238 > 11-keto TZP-4238. Male beagle dogs aged 1-6 years were randomly divided into TZP-4238 (0.05, 0.5mg/kg) treatment groups and CMA (0.5mg/kg) treatment group. Each group was administered the drug per os every day for 8 weeks. Plasma cortisol, TZP-4238 and its metabolite levels were measured by on-line coupling of liquid chromatography with thermospray or atmospheric pressure ionization mass spectrometry using selective ion monitoring (LC-MS/SIM). LC-MS/SIM provided a sensitive and reliable method of unequivocal confirmation of the presence of steroidal drugs in the plasma. The plasma cortisol level was lowered below 1 ng/ml at 1 week after oral administration of TZP-4238 at 0.5mg/kg or CMA at 0.5mg/kg. The decline continued throughout the treatment for 8 weeks. Upon termination of administration, the cortisol level returned to the normal level (6ng/ml) by 4 weeks. However in the group given 0.05mg/kg TZP-4238, the cortisol level remained within the normal range. To analyze the cortisol decreasing mechanism, we administered TZP-4238 at 0.5mg/kg for 7 days to one beagle dog. When the plasma 11-OH TZP-4238 level was increased, the cortisol level decreased time dependently and the concentration of plasma 11-OH TZP-4238 which induced 50% inhibition was 2ng/ml. The decrease in the plasma cortisol level was highly correlated to the extent of the increase of the plasma 11-OH TZP-4238 (r2 = 0.840). We conclude that the adrenosuppressive effect of antiandrogen TZP-4238 is not due to TZP-4238 itself but its metabolite 11-OH TZP-4238.

Adrenal Cortex↗
PubMed1994

[Preliminary report on the usefulness of 123I-IMP scintigraphy in distant metastases from hepatocellular carcinoma: except for bone and lung metastases].

N-isopropyl-p-[123I] Iodoamphetamine (IMP) scintigraphy was performed in 10 lesions of metastatic hepatocellular carcinoma. Five of 10 lesions (50%) were detected with planar images, which was superior to the 2 of 8 lesions (25%) detected with 67Ga-citrate (Ga) scintigraphy. The positive ratio was increased to 83% (5/6) with SPECT. Thus our findings suggested that IMP could compensate for Ga scintigraphy in detecting distant metastases of hepatocellular carcinoma.

Adrenal Gland Neoplasms↗
PubMed1994

Genomic organization and structure of Bruton agammaglobulinemia tyrosine kinase: localization of mutations associated with varied clinical presentations and course in X chromosome-linked agammaglobulinemia.

X chromosome-linked agammaglobulinemia is a life-threatening disease that involves a failure in normal development of B lymphocytes and is associated with missense mutations in BTK, a gene encoding a cytoplasmic tyrosine kinase (Bruton agammaglobulinemia tyrosine kinase, EC 2.7.1.112), a member of the Tec family of protein-tyrosine kinases. The genomic organization has been determined by using conventional restriction fragment mapping, extended DNA sequencing, and PCR fragment-sizing approaches. The DNA sequences of the 18 coding exons composing BTK and their flanking-region sequences are reported; an additional exon(s) encodes a 5' untranslated segment. Single-base-pair substitutions and 4-nt deletions resulted in amino acid replacement, premature termination, frameshift, and exon deletion in a group of X chromosome-linked agammaglobulinemia patients exhibiting different clinical presentations and courses. The nature of the mutations is interpreted in terms of the genomic organization of the BTK gene and the disease course in individual patients. Several examples are found in which the same mutation occurs in unrelated patients, and one of these mutations occurs at the same codon that is substituted in the murine form of BTK, resulting in X chromosome-linked immunodeficiency disease. Considerable variation in presentation and disease course in X chromosome-linked agammaglobulinemia appears associated with the nature and position of different missense mutations.

Agammaglobulinaemia Tyrosine Kinase↗
PubMed1994

Rotation and membrane topology of genetically expressed methylcholanthrene-inducible cytochrome P-450IA1 lacking the N-terminal hydrophobic segment in yeast microsomes.

A modified rat liver cytochrome P-450IA1, lacking amino acids 2-30, a proposed membrane anchor for cytochrome P-450, was expressed genetically in yeast microsomal membranes. This truncated cytochrome is practically active in the deethylation of 7-ethoxycoumarin. A full-length cytochrome P-450IA1 was also expressed in yeast microsomes. Rotational diffusion of P-450IA1 was examined by observing the flash-induced absorption anisotropy r(t) of the P-450.CO complex. The anisotropy decayed to a time-independent value within a 2-ms time range. Since the decay curve has the characteristics of a slow rotation of membrane-embedded cytochrome, the theoretical analysis of r(t) was performed based on a "rotation-about-membrane normal" model. 41% of the shortened P-450IA1 was rotating with the rotational relaxation time phi of 1020 microseconds, whereas 27% of the full-length P-450IA1 was mobile with phi = 1101 microseconds. The high salt treatment did not remove the shortened cytochrome from the membrane and also did not drastically weaken the interactions of the cytochrome with the membrane, as judged from the slow rotation characteristics (phi = 830 microseconds). These results demonstrate that the N-terminal shortened P-450IA1 is incorporated properly into the yeast microsomal membrane and that the N-terminal hydrophobic segment is not solely responsible for attachment to the membrane, providing evidence that additional segments of P-450IA1 are involved in the membrane binding.

Animals↗