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Biomedical subjects

T Sakamoto

Publications and source records attributed to T Sakamoto.

At least 847 records · Page 47Linked to original sources
PubMed1991

[Interstitial hyperthermia (MINERVE) for perineal local recurrence of rectal cancer].

Interstitial hyperthermia (MINERVE) was performed for 2 patients with perineal local recurrence of rectal cancer. The MINERVE was a 20 W generator of 550-610 kHz with 4 pairs of probes creating an electromagnetic field (Odam Co., France). The basic regimen was five irradiation treatments of 2 Gy per week, with two hyperthermia treatments (for 60 minutes at more than 43.5 degrees C) a week, 500 mg of 5-FU or 25 mg of CDDP per hyperthermia treatment, and 3 g/day of PSK. The radiation therapy was performed prior to hyperthermia, the chemotherapy at the same time. Perineal tumors and symptoms disappeared completely in 1 patient and were reduced in 1 patient. This treatment is expected to be clinically as a part of multidisciplinary treatment for superficial malignant tumors.

Adult↗
PubMed1991

[Doppler hemodynamic evaluation of bioprosthetic valve failure in the mitral position].

M-mode and two-dimensional echocardiography (2DE) allows the accurate assessment of primary tissue degeneration of bioprosthetic valves. The Doppler method permits quantitative evaluation of the pressure gradient across the prosthetic valve or detection of regurgitant flow. The present study summarized our clinical experiences of serial cases of mitral valve replacement (MVR) with bioprostheses at the mitral position, and clarified the clinical usefulness and limitations of Doppler and 2DE examinations for the early detection of primary valve dysfunction. Consecutive 65 patients undergoing single mitral valve replacement from April, 1977 to November, 1979 were listed for the study. A survey of the present clinical status was carried out from July, 1988 to July, 1990 (a follow-up period ranged from 84 to 127 months) for all patients, and the information was available from 53 patients (47 adults and six infants). Twenty-four survived patients without re-MVR were examined by Doppler and 2DE. Among the 53 patients, 34 were alive and 19 dead, and the total survival rate was 64.2%. The reasons for death in 19 patients were perioperative death in seven (including four infants with severe calcification of bioprostheses), chronic heart failure in three, cerebral infarction in two, post blood transfusion hepatitis in two, endocarditis in one, and non-cardiac death such as cancers in four. During the long-term observation of 47 adult patients, 14 cases (30%) had re-MVR (one for a stenotic lesion with massive calcification, and 13 for torn leaflets). Thickening and/or torn leaflets were noted in 13 (54%) of the 24 survived patients without re-MVR.2+ suggests that bioprosthetic valve replacement at the mitral position may not be recommended.

Adult↗
PubMed1991

[From Bentall's operation to its modification by Suzuki: improved technique for replacement of both aortic valve and ascending aorta].

To improve the result of surgery for replacement of both aortic valve and ascending aorta, we developed a new technique which is characterized as follows. 1) The composite graft is made during surgery according to the operative findings with tilting disc valve and very low porosity woven Dacron graft. 2) Proximal anastomosis is reinforced by double fixation method. 3) Coronary arteries are reimplanted directly into the graft as a Carrel patch. Thirty-four patients underwent this surgery with no operative death. One died in the hospital and 4 died in the late stage unrelated to the surgical technique. We recommend this method as a new standard technique for replacement of both aortic valve and ascending aorta.

Aorta↗
PubMed1991

[Auditory brain stem response in patients with consciousness disturbance].

To investigate the prognosis for patients with consciousness disturbance, we recorded auditory brain stem response (ABR) in 35 patients with primary or secondary brain damage. For patients with secondary brain damage, the first ABR recorded after admission could be used not only to differentiate consciousness level but also to predict prognosis. However, for the patients with primary brain damage, the first ABR could not be used for either differentiating consciousness level or predicting prognosis. In addition, in two patients with secondary brain damage, the series of ABR recordings indicated that brain stem damage was reversible.

Adolescent↗
PubMed1991

[Usefulness of transesophageal echocardiography in thoracic aortic disease: comparison with computed tomography and angiography].

To evaluate the usefulness of transesophageal echocardiography in thoracic aortic disease, transesophageal echocardiography was performed in 11 patients with thoracic aortic disease (true aortic aneurysm in two patients, aortic dissection in nine patients). Findings obtained by transesophageal echocardiography were compared with those obtained by computed tomography (nine patients) and angiography (six patients). Results were as follows: 1. True aortic aneurysm: Although transesophageal echocardiography and computed tomography could evaluate the size of the aorta and detect mural thrombus, angiography underestimated degree of aortic dilatation because of the presence of mural thrombus. 2. Aortic dissection: Although computed tomography could not differentiate thrombus in the false lumen from mural thrombus in two patients, transesophageal echocardiography could discriminate those two easily in one patient from properties and motion of the intimal flap, and flow information in the false lumen. Angiography could not evaluate the range of dissection in any patients with thrombus in the false lumen. With transesophageal echocardiography we could detect the entry in all six patients with aortic dissection of DeBakey type III except 1 patient with aortic dissection of DeBakey type I. Transesophageal echocardiography could obtain real-time image of most of the aorta except for a part of the ascending aorta. Therefore, transesophageal echocardiography was useful for diagnosing thoracic aortic disease and distinguishing between true aortic aneurysm and aortic dissection.

Aged↗
PubMed1991

[Changes of responses of gastrointestinal hormones after pancreatectomies].

In order to elucidate the changes of the gastrointestinal hormones (GIH), glucose and/or lipid were administered orally in 54 pancreatectomized patients, 22 gastrectomized patients and 28 healthy volunteers before and after the surgery. Peripheral plasma levels of cholecystokinin (CCK), neurotensin (NT), gastric inhibitory polypeptide (GIP) and pancreatic polypeptide (PP) were measured for 180 min by radioimmunoassay specific for each CIH. Hyperresponses of CCK, NT and GIP were observed before surgery in patients with tumor of the pancreatic head. The lack of bile in the alimentary tract was confirmed as one of causative factors for the hyperresponse of NT. No significant change was observed in response of CCK, NT, CIP and PP after caudal pancreatectomy. The responses of CCK and GIP were normalized after pancreatoduodenectomy (PD) or total pancreatectomy (TP). The response of PP was decreased after PD or TP. Such change of GIP was not noted after gastrectomy. These changes of GIH after pancreatectomies were considered to be caused by surgical removal of the structures in which these GIH mainly located.

Adult↗
PubMed1990

Expression of novel DNA-binding protein with zinc finger structure in various tumor cells.

We have isolated from B16 mouse melanoma cells a complementary DNA (Mel-18), whose deduced amino acid sequence possesses a characteristic zinc finger structure. Immunostaining with antibodies raised against partial Mel-18 peptide sequences demonstrated nuclear localization of the gene product. We have also demonstrated that this protein has DNA-binding capacity, and the zinc finger is responsible for the DNA binding. At the transcriptional level the Mel-18 mRNA was detected in all tumor cells examined as well as melanoma cells (ontogenically of neural origin) but was scarcely present in normal tissues except neural organs. The transcript is developmentally regulated. These data suggest that Mel-18 may play a role in transcriptional regulation and also in control of cell proliferation and/or neural cell development.

Amino Acid Sequence↗
PubMed1990

Lymphangioma of the jejunum: report of a case.

We report a very rare case of jejunal lymphangioma. A 16-year-old male sustained injuries to abdominal internal organs in a traffic accident. During emergency operation, a cystic tumor was incidentally detected in the jejunum and adjoining mesenterium and treated by segmental resection of the jejunum. The cystic tumor (5.0 x 7.0 cm) was multilocular and demonstrated to be a cavernous lymphangioma by histopathological examination. The pathology, diagnosis, and treatment of this disease described in the literature are reported.

Adolescent↗
PubMed1990

Follow-up in mitral valve prolapse by phonocardiography, M-mode and two-dimensional echocardiography and Doppler echocardiography.

To assess the serial phonocardiographic and echocardiographic change in patients with mitral valve prolapse (MVP), phonocardiograms and echocardiograms were reviewed retrospectively in 116 patients (48 men and 68 women, mean age 27 years) who had been determined to have MVP and were reexamined 4.3 years (range 1 to 14) later by phonocardiography and echocardiography between 1971 and 1988. Follow-up phonocardiograms showed periods when 5 of 18 patients with silent MVP developed mid- or late systolic clicks. Of 57 patients with mid- or late systolic clicks, 15 had silent MVP, 6 developed a late systolic murmur with or without systolic clicks and 1 developed a pansystolic murmur. Two of 9 patients with an isolated late systolic murmur developed a pansystolic murmur. M-mode echocardiograms showed that left atrial and left ventricular dimensions at end-diastole and end-systole increased in patients with systolic murmur (33 +/- 10 vs 35 +/- 11, 46 +/- 6 vs 50 +/- 7 and 29 +/- 4 vs 31 +/- 5 mm, respectively, all p less than 0.001) and no statistically significant changes in any of these dimensions were found in patients without a systolic murmur. The degree of MVP evaluated by the anteroposterior mitral leaflet angle on the 2-dimensional echocardiogram was more severe in patients with a systolic murmur than in patients without systolic murmur (157 +/- 12 vs 131 +/- 16 degrees, p less than 0.001). The degree of prolapse did not change during the follow-up periods. The number of patients with mitral regurgitation detected by pulsed Doppler echocardiography increased from 21 of 72 (29%) to 31 of 72 (43%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Morphological and physiological identification of neurons in the cat motor cortex which receive direct input from the somatic sensory cortex.

The population of neurons in the cat motor cortex which receives monosynaptic input from a specific functional region of the somatic sensory cortex was identified with the techniques of intracellular recording and staining with HRP. Both pyramidal and nonpyramidal cells located in the superficial layers of the pericruciate cortex responded to stimulation of the sensory cortex with short latency, excitatory postsynaptic potentials. More than half of the labeled cells were classified as pyramidal cells and the remainder as sparsely spinous or aspinous nonpyramidal cells. The characteristics of the EPSP's of the 2 groups of cells, ie. latency, time from beginning to peak and amplitude were found to vary only slightly. The results suggest that input from the sensory cortex impinges upon neurons which may in turn have an excitatory or inhibitory effect on cortico-fugal neurons in the motor cortex.

Animals↗
PubMed1990

The characteristics of coronary artery revascularization in aged patients.

This study was undertaken in order to clarify the clinical characteristic features and surgical results of coronary artery bypass grafting (CABG) in patients over 65 years of age (group III, n = 43). These patients were compared with 2 other groups of patients, one aged between 50 and 59 years (group I, n = 88) and another aged between 60 and 64 years (group II, n = 54), with respect to mortality, morbidity and late survival. CABG was performed with the saphenous vein under cold K-Mg-cardioplegia with systemic hypothermia. The hospital mortality was 2.3, 3.7, and 4.7 per cent in groups I, II and III, respectively, although no operative mortality was noted in any group. The number of coronary artery lesions increased with age, however, the left ventricular ejection fraction was relatively better preserved in the aged patients than in the younger ones. The 5-year survival rates were 93.4, 95.1 and 96.9 per cent in groups I, II and III, respectively, with most of the late deaths occurring within a year after CABG in each group. In the aged patients, postoperative functional recovery was delayed in the liver and kidney, and postoperative psychosis was not infrequent. The results of this study, indicating a low operative mortality and satisfactory late survival rate, thus strongly support CABG for the aged. Nevertheless, the prevention of postoperative complications is also extremely important for reducing hospital mortality.

Aged↗
PubMed1990

Expression of human alpha-fetoprotein in yeast.

Human alpha-fetoprotein (AFP) was expressed in Saccharomyces cerevisiae, with a plasmid containing the cDNA sequence for human AFP fused with the rat AFP signal peptide. The recombinant AFP was purified from the yeast lysate by DEAE-cellulose and immunoaffinity chromatography. The amino acid composition and the molecular weight of the recombinant AFP were similar to those of hepatoma AFP. N-terminal amino acids sequence analysis indicated that the signal peptide had been processed. The recombinant and hepatoma AFP reacted identically in Ouchterlony immunodiffusion and radioimmunoassay tests. These observations indicated that the yeast recombinant protein had the properties of native AFP.

Amino Acid Sequence↗
PubMed1990

Subrenal capsule assay as a test to predict the effectiveness of chemotherapy in choriocarcinoma.

The value of the 6-day subrenal capsule assay (SRCA) in predicting the effectiveness of chemotherapy was tested using three human choriocarcinomas. The SRCA method proved to be a valuable chemopredictive test for choriocarcinoma. The results of experimental chemotherapy in nude mice and the results of the SRCA in two types of choriocarcinoma correlated well. Two of three choriocarcinomas showed sensitivity to MAC combination chemotherapy [methotrexate, actinomycin D, cyclophosphamide), and all three showed greater sensitivity to VP-16. The administration of VP-16 for treatment of all three types of choriocarcinoma significantly reduced tumor size in a dose-dependent fashion. From these observations, we speculate that the SRCA may be applied to assess the effectiveness of chemotherapy against human choriocarcinoma.

Animals↗
PubMed1990

Regional spinal cord blood flow during local cooling.

We used the tissue distribution of [14C]butanol to quantitate regional blood flow in the spinal cord (RSCBF) of pentobarbital-anesthetized, normothermic rats in which segmental local cooling pentobarbital-anesthetized, normothermic rats in which segmental local cooling of the spinal cord (to 25-28 degrees C) at vertebral levels C4-C6 (n = 6) or T13-L1 (n = 6) was induced. Thirty minutes later, blood flow measurements were made at seven levels of the spinal cord and in the sciatic nerve trunks and biceps femoris muscles. Sham-cooled rats served as controls (n = 12). In control rats, RSCBF varied between 41.5 +/- 2.4 and 65.1 +/- 3.2 ml.min-1.100 g-1. Local cooling of the C4-C6 cord segment reduced RSCBF by 32%, from 65.1 +/- 3.2 to 44.4 +/- 3.5 ml.min-1.100 g-1 (P less than 0.01). Tissue vascular resistance (R) in the cooled C4-C6 segment was elevated versus control. There were no other changes in RSCBF at the other cord levels or in the cauda equina. Similarly, local cooling of the T13-L1 segment resulted in a 40% fall in RSCBF in that segment, from 57.1 +/- 2.4 to 34.1 +/- 4.3 ml.min-1.100 g-1 (P less than 0.001). R in the cooled T13-L1 segment was elevated versus control. RSCBF was reduced by 30% in the adjacent proximal T12 segment (P less than 0.001) and by 21% in the adjacent distal L2-L3 segment (P less than 0.05). R was increased in both of these adjacent segments. RSCBF was not altered elsewhere in the cord.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Intestinal phase of pancreatic polypeptide release: the effect of segmental perfusion of the small intestine with various secretagogues.

The purpose of this study was to examine the effect of various nutrients perfused selectively into isolated sections of the small intestine on the release of pancreatic polypeptide (PP). Six dogs were prepared with chronic gastric, duodenal, and three permanent intestinal fistulas (one distal to the ligament of Treitz, one in the terminal ileum, and one halfway between). After a 24-h fast, the duodenum was perfused for 45 min (200 ml/h) via the duodenal limb with HCl (30 mM), an amino acid solution (50 mM), or sodium oleate (NaO, 40 mM). In separate studies, the jejunal and ileal segments were isolated by inflating two balloon catheters via the intestinal fistula, and these segments were perfused as described earlier. Plasma PP, cholecystokinin (CCK)-33, and secretin levels were measured. Results of this study showed that the perfusion of all segments of the small intestine with amino acid caused a significant elevation of plasma PP levels. Perfusion of the duodenum and jejunum but not the ileum with a fatty acid resulted in a significant elevation of plasma levels of PP. Perfusion of HCl into any segment did not affect plasma levels of PP. This study shows that PP is released by the presence of nutrients in all segments of the small intestine, and that a PP elevation was always accompanied with a rise in plasma levels of CCK-33.

Animals↗
PubMed1990

Fc epsilon receptor II/CD23 positive lymphocytes in atopic dermatitis: II. Infiltration of Fc epsilon R II(+) T cells in the skin lesion.

Cells expressing Fc receptors for IgE (Fc epsilon R II) were identified in skin from patients with atopic dermatitis (AD), eczematous dermatitis (ED), and in skin from normal nonatopic subjects, with the use of monoclonal antibodies to human lymphocyte Fc epsilon R II, H107, and to lymphoid cell-surface antigens by double immunofluorescence staining. Two to four percent of infiltrating mononuclear cells expressed Fc epsilon R II, and more than half of these cells were T epsilon cells in both acute and chronic AD lesions. Fc epsilon R II(+) T cells (T epsilon cells) bearing CD8 infiltrated preferentially acute lesions, whereas chronic lesions contained either CD8(+) or CD4(+) T epsilon cells, or both. Fc epsilon R II(+) cells rarely were present in ED lesions. There was no significant correlation between % Fc epsilon R II(+) peripheral blood mononuclear cells and the proportion of lesional Fc epsilon R II(+) cells, extent of skin lesions, or serum IgE levels, implying the selective accumulation of Fc epsilon R II(+) cells in the inflammatory infiltrate of AD. These observations suggest that the increased generation of Fc epsilon R II(+) cells in skin lesions, including CD8 (+) T epsilon cells, is involved in the pathogenesis of AD.

Adolescent↗
PubMed1990

Application of mathematical model to experimental chemotherapy of fatal murine pneumonia.

Two beta-lactam antibiotics, cefazolin and cefmenoxime, were administered in an experimental model of murine pneumonia caused by Klebsiella pneumoniae in a way which enabled us to approximate the serum antibiotic concentration time course in humans. Bacterial counts during the experiments were subjected to nonlinear least-squares analyses by using a mathematical model that explained the bacterial killing by the antibiotic concentration time course and other factors associated with antimicrobial potency and bacterial growth. Cefazolin gave a killing curve that changed synchronously with the drug levels in serum; in contrast, cefmenoxime gave a curve that was prolonged as compared with the change in the drug levels in serum. Multiple correlation coefficients were about 0.9, and the model worked well for bacterial count data. Parameters relating to antimicrobial potency of the drugs, bacterial growth rate, and drug distribution into the tissue were estimated numerically.

Animals↗