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Biomedical subjects

Y Baba

Publications and source records attributed to Y Baba.

At least 181 records · Page 10Linked to original sources
PubMed1995

Hepatocellular carcinoma in cirrhotic livers: detection with unenhanced and iron oxide-enhanced MR imaging.

PURPOSE: To evaluate diagnostic accuracy with unenhanced and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging for detection of hepatocellular carcinoma (HCC) in cirrhotic livers. MATERIALS AND METHODS: Fifteen patients with 26 histologically proved HCCs associated with liver cirrhosis underwent imaging with T1-, T2-, and proton-density-weighted spin-echo (SE) and fast low-angle shot (FLASH) sequences. Lesion-to-liver contrast-to-noise ratios were measured in all sequences. Diagnostic performance of the imaging techniques was assessed by using receiver operating characteristic analysis. RESULTS: Enhanced SE and FLASH sequences were significantly more accurate (P < .005) for the detection of small HCCs. Among the unenhanced pulse sequences, the accuracy of tumor localization was highest with the T2-weighted SE sequences; however, 25% of the lesions were located incorrectly. Compared with unenhanced images, lesions were correctly located more often when SPIO-enhanced SE and FLASH sequences were used. CONCLUSION: SPIO-enhanced MR imaging with proton-density-weighted or FLASH sequences was more accurate in the detection of small HCCs in cirrhotic livers.

Biopsy↗
PubMed1995

Superselective intraarterial infusion of cisplatin for squamous cell carcinoma of the mouth: preliminary clinical experience.

OBJECTIVE: The purpose of this study was to assess the initial clinical response to superselective intraarterial infusion of cisplatin for treating stage III and stage IV squamous cell carcinoma of the mouth. SUBJECTS AND METHODS: Thirteen patients received intraarterial cisplatin therapy. The tumors were located in the tongue (n = 7), gingiva (n = 3), buccal mucosa (n = 1), hard palate (n = 1), and floor of the mouth (n = 1). A coaxial technique was used to place microcatheters in the lingual, facial, inferior alveolar, buccinator, and distal internal maxillary arteries, depending on tumor location. The feeding vessels were identified by staining the tumor with infusion of indigocarmine dye in the selected vessel. Relatively low-dose cisplatin (30-40 mg/m2) was injected at the rate of 50 mg/hr. Two or three injections were performed, with a 1-week interval between injections. After chemotherapy, eight patients underwent surgery, four had radiation therapy, and one had both. RESULTS: Thirty-four intraarterial infusions were done successfully without any complications. Arterial infusion of indigocarmine dye was useful for exact identification of feeding vessels, especially when the tumor was extensive, at the margin of the arterial supply, or near the midline. The overall response rate was 92% (complete response [tumor completely resolved], 38%; partial response [tumor reduction > or = 50%], 54%). Ten of 13 patients had no recurrence from 4 to 19 months (mean, 10 months) after treatment. Two patients died of metastatic diseases 6 months after surgery or radiation therapy. One patient had local recurrence 8 months after surgery and postoperative irradiation. No systemic toxicity such as renal failure, liver dysfunction, or bone marrow suppression was observed. Mild and transient local toxicity such as edema or mucositis of the infused area was relatively common. Trigeminal neuralgialike symptoms and reduced mouth opening occurred in two cases and one case, respectively, probably due to direct toxicity to the peripheral trigeminal nerve and masticatory muscles, respectively. CONCLUSION: Superselective intraarterial infusion of low-dose cisplatin is feasible and safe and may have important applications in treating advanced carcinoma of the mouth.

Aged↗
PubMed1994

The fertilization potential provides a fast block to polyspermy in lamprey eggs.

At fertilization, the membrane potential of the egg of the lamprey, Lampetra japonica, shifted rapidly from its resting value of -12 to +36 mV and gradually returned to about the same resting level (fertilization potential). The amplitude of depolarization was influenced by the external Cl- concentration and by an anion channel blocker, DIDS, indicating that the positive shift of membrane potential resulted from Cl- efflux. A similar change in membrane potential (activation potential) was observed when the unfertilized egg was pricked with a fine needle or treated with A23187 to induce parthenogenetic activation. Pricking at the animal pole region (predetermined site for sperm entry) resulted in the occurrence of an immediate activation potential and the initiation of cortical granule exocytosis. A time lag between the pricking and the occurrence of the activation potential was observed when the egg was pricked at a distance from the animal pole. In this instance, the activation potential was produced immediately before the propagating cortical granule exocytosis initiated at the pricked site reached the animal pole region. Sperm-egg fusion was blocked in eggs voltage-clamped at +20 to +40 mV and inseminated, whereas it took place in eggs clamped at -60 to 0 mV. However, most eggs clamped at +20 to +40 mV did activate, indicating that the voltage dependence of egg activation differs from that of sperm-egg fusion. Although eggs voltage-clamped at negative membrane potentials permitted multiple sperm to fuse with the egg plasma membrane, the nucleus of the fused sperm did not necessarily enter the ooplasm. We conclude that: (1) A fast electrical block against polyspermy operates in this species and is effective for about 160 sec of the onset of the positive shift; (2) the opening of Cl- channels is responsible for the potential change; (3) the channels are largely localized in the animal pole region; (4) during voltage clamp at positive potentials, eggs can be activated without sperm-egg fusion; and (5) during voltage clamp at negative potentials, sperm-egg fusion occurs, but sperm entry into the egg cytoplasm does not always proceed.

Animals↗
PubMed1994

Intra-abdominal desmoplastic small cell tumour in a patient with Peutz-Jeghers syndrome.

A surgical case of intra-abdominal desmoplastic small cell tumour with divergent differentiation (IDS-CT) in a patient with Peutz-Jeghers syndrome (PJS) is reported. The patient was a 23-year-old woman who underwent surgery for a tumour in the left paraovarian region. Widespread peritoneal metastases were noted. Histopathological examination revealed solid cell nests composed of medium-sized cells demarcated by desmoplastic stroma. Gland-like spaces were found within many cell nests. Tumour cells were positive for cytokeratin and smooth muscle actin, but negative for desmin. Both ovaries contained minute foci of a sex cord tumour with annular tubules. This is the first documentation of the association of IDSCT with PJS. Since patients with PJS have an increased risk of cancer in various organs, the occurrence of IDSCT in the present patient might not be fortuitous.

Adult↗
PubMed1994

Primary cerebellar yolk sac tumor: case report.

A rare case of cerebellar yolk sac tumor is described. A 4-year-old boy was admitted for the treatment of a cerebellar tumor and, following total removal of the tumor, he was treated with combination chemotherapy consisting of cisplatin, vinblastine, and bleomycin. He died 18 months after the primary diagnosis due to tumor recurrence. Serum alpha-fetoprotein level was well correlated with the clinical course and the amount of the tumor mass in neuroimaging.

Cerebellar Neoplasms↗
PubMed1994

Endoscopic resection of early gastric carcinoma: results of a retrospective analysis of 308 cases.

The purpose of this study was to define the indications and limitations of endoscopic resection (ER) of early gastric carcinoma (EGC). Over the 15 year period from 1978 to 1992, 308 early cancers were resected endoscopically either through a single operative intervention or in stages. Of 266 lesions resected in a single step, 222 (85%) entered remission. Forty-four cases had either residual or recurrent lesions. The size, histology and location affected the curability; 89% of Type IIa lesions less than 2 cm were resected curatively, while only 50% of those larger than 2 cm were resected completely. In Type IIc, 83% of lesions less than 1 cm and 57% of those greater than 1 cm were excised completely by ER. In Type IIc, curative ER was possible in 85% of differentiated carcinomas and 43% of undifferentiated carcinomas. The rate of incomplete resection was higher for lesions of the anterior or posterior wall, than for those of the lesser curvature. Semiserial sections of the resected specimens made at 2 mm intervals, indicated that, if the positive margin was confined to one section, cure may be possible by the burning effect. Follow-up showed that there was no single case undergoing endoscopic resection which subsequently died of gastric carcinoma. The lesions that are suitable for ER comprise Type IIa EGC of less than 2 cm in diameter, and Type IIc differentiated adenocarcinoma of less than 1 cm. Lesions in which the entire margin is difficult to observe by front-view endoscopy should be smaller than defined by the above criteria.

Adenocarcinoma↗
PubMed1994

Population analysis of cellular responses to synthetic peptides of Der p II, a major allergen molecule of Dermatophagoides pteronyssinus, in allergic and nonallergic subjects.

Responses of peripheral blood mononuclear cells to synthetic oligopeptides of Der p II, one of the major allergen molecules of Dermatophagoides pteronyssinus, were compared between allergic and nonallergic subjects. Healthy subjects showed positive responses to crude extracts of D. pteronyssinus, but only allergic subjects showed elevated cellular responses to Der p II. We synthesized three oligopeptides of Der p II in which motifs of a possible T-cell epitope were included. Of 14 subjects with positive response to Der p II, three responded to all three peptides, while five did not respond to any peptide tested. In 11 allergic patients who showed positive response to Der p II, responsiveness to the peptide K33-T47 was significantly higher than that to other peptides (P < 0.05). All the responding patients were also positive for scratch test to Der p II, suggesting that those epitopes induced IgE-promoting helper T-cell response in allergic persons. On the other hand, the in vitro cellular responses were not necessarily correlated to IgE production against Der p II in healthy subjects.

Adolescent↗
PubMed1994

A flow visualization study of the NCVC centrifugal blood pump.

A compact centrifugal pump, NCVC-1, has an open-type impeller with 6 curved vanes, and it is characterized by no shaft and no seal. A tunnel is placed in the center of the impeller-rotor assembly to irrigate the back space behind the rotor. To evaluate the flow, we performed 3 visualization methods: tracer, oil film, and injection streak line method. The flow, observed by the tracer method in NCVC-1, indicated little turbulence along vanes. A volute chamber proved effective to reduce vortex formation in the outlet. Oil film pattern revealed no flow separation on vanes at 5 L/min. Washout flow behind the rotor is essential to prevent thrombus formation and was shown as inward spiral flow without any stagnation. These data suggested that a combination of visualization techniques was useful to analyze various flow conditions, and the NCVC-1 has excellent flow characteristics with little turbulence and little flow stagnation, which must be beneficial to low hemolysis and high antithrombogenicity.

Heart-Assist Devices↗
PubMed1994

Synthesis and aldose reductase inhibitory activity of 2-substituted 6-fluoro-2,3-dihydrospiro[4H-1-benzopyran-4,4'-imidazolidine]-2',5'-dio nes.

Optically active and racemic 2-substituted 6-fluoro-2,3-dihydrospiro[4H-1- benzopyran-4,4'-imidazolidine]-2',5'-diones were synthesized stereoselectively from (+)-, (-)-, and (+/-)-6-fluoro-3, 4-dihydro-4-oxo-2H-1-benzopyran-2-carboxylic acid [(+)-1, (-)-1, and (+/-)-1], respectively, for evaluation as new aldose reductase inhibitors. Among these compounds, the 2S,4S compounds were found to be more potent inhibitors of aldose reductase in vitro and in vivo than the corresponding 2R,4R enantiomers. The chloromethyl compound [(+)-5] showed highly potent activities in inhibiting cataract formation in the lenses and polyol accumulation in the sciatic nerve of rats.

Aldehyde Reductase↗
PubMed1994

Evaluation of cancer prevention strategies by computerized simulation model: methodological issues.

A computerized simulation model developed to evaluate the potential impact of primary and secondary prevention is discussed from methodologic perspectives. In the simulation model, named CANSAVE (Cancer Strategy Analysis and Validation of Effect), the natural history of cancer was modeled as a Markovian stochastic process from cancer-free state to death. The lung cancer death rate among Japanese males was projected for 50 years to the year 2041. The simulation showed that the age-adjusted death rate would increase and reach a peak of 166 per 100,000 in 1989 and then decrease to 148 in 2003. It then shows a tendency to increase again, up to 255 in 2028. This change may be attributed to a lower smoking initiation rate among those born in the 1930s. Promotion of mass screening programs exhibits a more prompt effect than antismoking efforts, but the reduction in annual deaths is expected to be only 11%, even if a 100% participation is realized by the year 2000. The reduction in smoking initiation rate, on the other hand, begins to show a visible effect very slowly. It was predicted that a 1% annual reduction in smoking initiation rate would result in a 20% decrease in the number of deaths in 2041. The smoking cessation program is in the middle with regard to promptness. The predicted reductions in lung cancer deaths in 2041 were 13, 47, and 66%, respectively, when the annual smoking cessation rate was increased from 0.46% (present status) to 1, 3, and 5%. The combined application of all three preventive measures seems essential to realize the most effective reduction in lung cancer deaths.

Adult↗
PubMed1994

Radiation therapy of adult T-cell leukemia.

Between January, 1983 and December, 1991, 30 adult patients with T-cell leukemia (ATL) and lymph node or skin lesions resistant to chemotherapy were treated by irradiation. Thirty Gy of high energy x-rays, 60Co gamma rays or electrons was delivered to 22 lymph node lesions in 17 patients, for focal cutaneous lesions in 6 patients, and as total skin irradiation in 7 patients. Irradiation therapy was effective in all patients with skin lesions and in 12 of 17 patients with lymph node lesions. Symptoms such as pain or itching diminished in all cases and no severe side effects were observed. Radiation therapy thus achieved good control of ATL associated focal lesions resistant to chemotherapy. Even if the prognosis of ATL is poor, radiation therapy should be considered as a palliative therapy.

Adult↗
PubMed1994

Gastric carcinoma.

This article considers the significance and role of classic barium radiology in the diagnosis of gastric carcinoma and correlates it with endoscopy and other diagnostic modalities. Technical considerations for demonstrating optimum radiographic images of gastric carcinoma in terms of location, control of lumen distention, and positional setting are presented next. Finally, representative radiographic images of various morphologic types of gastric carcinoma are described and presented.

Humans↗
PubMed1994

[The indications for the use of salazosulfapyridine in rheumatoid arthritis patients].

In an attempt to clarify the background of patients with rheumatoid arthritis (RA) who should be treated with salazosulfapyridine (SASP), a tree classification of responders and non-responders to SASP was developed by analyzing 88 RA patients administered with SASP, according to factors such as clinical findings, autoantibody and HLA antigen. Five clinical features were associated with increased efficacy of SASP: male sex, duration of illness of less than 10 years, initial use of SASP, negative RA test and negative antinuclear antibody. In the tree classification for SASP, there were 3 groups of responders: male sex, female sex + initial use of SASP + negative RA test, and female sex + previous treatment with disease-modifying antirheumatic drugs (DMARDs) +negative antinuclear antibody + negative RA test, while there were 5 groups of non-responders: female sex + previous treatment with DMARDs + negative antinuclear antibody + positive RA test with HLA DR9 or A24 + DR9, and female sex + previous treatment with DMARDs +positive antinuclear antibody with HLA A24, DR9 or A24 + DR9. The new tree classification for the efficacy of SASP in the present study facilitated clear distinction of responders and non-responders to the drug.

Adult↗
PubMed1994

[Endopyelotomy for ureteropelvic junction obstruction: results and complications].

We treated eleven cases of primary ureteropelvic junction obstruction with percutaneous endopyeltomy. Endopyelotomy was successful in nine of the eleven cases. Complications during and after endopyelotomy occurred in three cases, two of which had pyelonephritis and the other severe postoperative hemorrhage requiring blood transfusion due to incision of a posterior crossing vessel. In this last case, the kidney was supplied by three arteries. The lower segmental artery passed behind the ureter. We emphasized that angiography should be performed to rule out the presence of a posterior crossing vessel before endopyelotomy, when it is doubtful if an extrinsic cause of ureteropelvic junction obstruction is present.

Adolescent↗