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Biomedical subjects

J Yamamoto

Publications and source records attributed to J Yamamoto.

At least 253 records · Page 14Linked to original sources

[Myocardial imaging in acute myocardial infarction using beta-methyl-p-(123I)-iodophenylpentadecanoic acid: comparison with 201Tl imaging and wall motion].

Myocardial imaging using beta-methyl-p-(123I)-iodophenylpentadecanoic acid (BMIPP) was performed in 11 patients with acute myocardial infarction. The left ventricular images were divided into 12 segments, and myocardial imagings with BMIPP were compared with coronary angiography (CAG), thallium-201 myocardial scintigraphy (TL) and wall motion obtained by two-dimensional echocardiography (WM). When the culprit lesion was at the proximal point of the left anterior descending artery (LAD), all segments showed depressed uptake. In 3 cases with single vessel disease of the LAD, inferior wall of the basis showed reduced uptake of BMIPP despite the location of the culprit lesion. In cases with discordant uptake between the two tracers, BMIPP frequently showed more severely depressed uptake than TL in the subacute phase, although the uptake of BMIPP correlated with that of TL (tau = 0.82, p less than 0.001). In such cases, the discordance was related to the improvement in WM from the acute phase to the convalescent phase. BMIPP uptake correlated with WM in the subacute phase (tau = 0.50, p less than 0.001). BMIPP showed more severely depressed uptake while WM showed mild asynergy in most cases in which discordance was found between the BMIPP and WM findings. However, there was no correlation between the change in WM from the acute to subacute phases, or the uptakes of BMIPP and TL alone. We concluded that the myocardial condition can be evaluated in detail in acute myocardial infarction by comparing the findings of BMIPP with those of TL and WM.

Aged↗

[The influence of findings of coronary artery on myocardial salvage in acute myocardial infarction].

201Tl stress myocardial scintigraphy was performed in convalescent patients with acute myocardial infarction, to evaluate the influence of stenosis and collateral circulation of coronary artery in acute phase, on myocardial salvage in chronic phase. In 14 cases of unsuccessful coronary revascularization (complete occlusion), a complete defect of thallium imaging in chronic phase was seen in only one case of four cases with good collateral circulation, while eight of 10 cases with poor collateral circulation. In 16 cases of poor collateral circulation, six cases showed a complete defect, although the target vessel had improved to less than 75% of stenosis. However, in cases of good collateral circulation, no case showed a complete defect when the target vessel had improved to less than 75% of stenosis. The myocardial salvage is quite possible (p less than 0.05), when the coronary angiography in acute phase showed the forward flow (99% or 90% of stenosis) before coronary revascularization and/or good collateral circulation (Rentrop 2 degrees or 3 degrees).

Adult↗

Hwa-byung. A community study of Korean Americans.

One hundred nine Korean American community subjects were interviewed regarding their experiences with hwa-byung (HB), a Korean folk illness label commonly used by Koreans with a myriad of physiological and psychological complaints. During these interviews, standard instruments were also used to assess their depressive and somatic symptoms. The results indicated that a relatively high proportion (12%) of the subjects labeled themselves as having suffered from HB. While no apparent sociodemographic differences were found between HB and non-HB subjects, significantly more HB subjects fulfilled the diagnosis of DSM-III major depression and also had previous diagnoses of depression. The HB subjects also had significantly higher scores for the total, depressive, and somatic subscales and 16 of the 20 individual items of the Center for Epidemiologic Studies-Depression Scale. These data confirm previous observations of substantial overlap between HB and DSM-III major depression among Koreans and Korean Americans, and suggest that HB may be a culturally patterned way of expression for Koreans experiencing major depression and related conditions. The clinical and theoretical implications of these findings are also discussed.

Adult↗

[Effect of exercise on rats with renal injury].

Effect of exercise on rats with renal injury was studied. Nephritis was induced in rats by injection of anti-GBM antibody followed by ligation of a branch of the left renal artery after nephrectomy of the right kidney. Moderate daily treadmill exercise was forced on these experimental rats for ten weeks. Sedentary nephritic rats that received the same treatment described above served as controls. The sedentary nephritic rats suffered progressively increasing proteinuria during the time course of the experiment, whereas the nephritic rats with daily treadmill exercise experienced less proteinuria. Mild proteinuria was induced by daily treadmill exercise forced on non-nephritic rats that had received only nephrectomy of the right kidney, but no NTS injection. Light microscopy and immunofluorescence microscopy revealed severe glomerular injury in the sedentary nephritic rats, however, less glomerular injury was seen in nephritic rats with treadmill exercise. Serum cholesterol level was higher in the sedentary rats than in the rats with daily treadmill exercise. The results suggest that daily exercise by nephritic rats will not aggravate renal injury.

Animals↗

Identity of hemolysins produced by Bacillus thuringiensis and Bacillus cereus.

A hemolysin (Bt-hemolysin) produced by Bacillus thuringiensis var. kurstaki HD-1 producing crystalline toxin(s) was purified by successive treatments of ammonium sulfate (45-65%) and column chromatography using DEAE-cellulose, Sephadex G-75 and KB-002 (a hydroxyapatite column for fast protein liquid chromatography). A hemolysin (Bc-hemolysin) produced by B. cereus HG-6A was also purified by the same procedure. The purified Bt-hemolysin and Bc-hemolysin, both of which are thiol-activated hemolysins, were biologically, physicochemically and immunologically identical. These findings provide further evidence of the similarity of B. thuringiensis, which is being used as a biological insecticide, to B. cereus, a toxigenic organism of food poisoning.

Bacillus cereus↗

Tissue and subcellular distributions of an inhibitory GDP/GTP exchange protein (GDI) for the rho proteins by use of its specific antibody.

We have recently purified from bovine brain cytosol to near homogeneity a GDP/GTP exchange protein for the rho proteins, named rho GDI, that inhibits the dissociation of GDP from and the subsequent binding of GTP to the rho proteins. In the present study, we made a monoclonal antibody against rho GDI and studied its tissue distribution in rat and its subcellular distribution in rat cerebrum by use of this antibody. rho GDI was found in most rat tissues as described for the rho proteins. In rat cerebrum, rho GDI was mostly found in the cytosol of neuron body and synaptosome. In synaptosome, it was mainly found in the synaptic cytosol.

Animals↗

Tissue and subcellular distributions of an inhibitory GDP/GTP exchange protein (GDI) for smg p25A by use of its antibody.

We have recently purified from bovine brain cytosol to near homogeneity a GDP/GTP exchange protein for smg p25A, named smg p25A GDI, that inhibits the dissociation of GDP from and the subsequent binding of GTP to smg p25A. In the present study, we made an antiserum against smg p25A GDI and studied its tissue distribution in rat and its subcellular distribution in rat cerebrum by use of this antiserum. smg p25A GDI was found in secretory cells with both regulated and constitutive secretion types. Since smg p25A was previously found in only secretory cells with a regulated secretion type, this result suggests that small GTP-binding proteins different from smg p25A but recognized by smg p25A GDI are present in secretory cells with a constitutive secretion type, and that smg p25A GDI is involved in both regulated and constitutive secretory processes. In subcellular fractionation analysis of rat cerebrum, smg p25A GDI was mostly found in the cytosol fraction of neuron body and synaptosome. In synaptosome, it was mainly found in the synaptic cytosol.

Animals↗

Evidence of effective multidisciplinary treatment for resectable pancreatic cancer from the viewpoint of the CA19-9 level.

Nineteen patients with resectable pancreatic cancer have been treated by a multidisciplinary approach at the National Cancer Center Hospital. This therapy included extended pancreatic resection, intraoperative irradiation by 30 Gy of electrons, and intraoperative hepatic arterial or portal infusion of mitomycin C. Furthermore, postoperative chemotherapy with mitomycin C, using Seldinger's method or iv administration, was added. The study consisted of 13 patients with carcinoma of the pancreatic head and six patients with carcinoma of the body and tail. The one- and three-year survival rates for these patients were 88 and 50%, respectively. The five-year survival rate was calculated as 28%, although there is only one five-year survivor. The effectiveness of this therapy was studied by changes in Carbohydrate Antigen 19-9 (CA19-9) level. Thirteen of the 15 patients with high CA19-9 levels showed a decrease to a level less than 50 U/mL after this therapy. In the postoperative course, the patients showing a tendency of elevation of the CA19-9 level could be suspected of having cancer recurrence at this time without any physical sign or other laboratory findings.

Aged↗

T cell can recognize the allospecificities formed by the substitution of amino acids associated with HLA-Bw4/Bw6 public epitopes.

Our previous studies clearly showed that HLA-B35 and HLA-Bw53 differed only by the amino acids associated with HLA-Bw4/Bw6 epitopes, in that the former possessed Bw6 and the latter Bw4 epitope. It remains to be known whether T cell can discriminate HLA-B35 from HLA-Bw53, although the difference between these HLA antigens is discriminated by monospecific human alloantisera. To investigate allorecognition of these HLA antigens by T cells, anti-HLA-Bw53 cytotoxic T lymphocytes (CTLs) were generated. Anti-HLA-Bw53 cytotoxic T lymphocytes (CTLs) were generated. Anti-HLA-Bw53 bulk CTLs from an individual with HLA-B35 clearly discriminated HLA-Bw53 from HLA-B35. On the other hand, anti-HLA-Bw53 bulk CTLs from an individual without HLA-B35 revealed weak cross-reactivity with HLA-B35 and HLA-B51. The additional studies using HLA-Bw53 or HLA-B35-specific CTL clones showed that some but not all of the CTL clones definitively distinguish the difference between HLA-Bw53 and HLA-B35. Thus, the allospecificities formed by HLA-Bw4/Bw6 epitopes were discriminated by allogeneic T cells. The present study demonstrated that HLA-Bw4/Bw6 public epitopes play an important role in allorecognition of T cells.

Amino Acid Sequence↗

Concordance rate between clinical and DIS diagnoses: a cross-cultural comparison.

Concordance rates between clinical and DIS-generated diagnoses were compared using data sets from Fukuoka University in Japan and Neuropsychiatric Hospital at the UCLA. An overall concordance rate of 35% between standard clinical diagnosis and DIS-Lifetime diagnosis was discovered in both samples. Next, concordance rates were analyzed by diagnostic category, and differential concordance rates among major diagnostic categories were found in both samples. The highest concordance rates were found in anxiety disorders and major depression. The lowest concordance rates were found in dysthymic disorder and schizophrenia. The Fukuoka sample contained more patients with anxiety disorders and major depression, while the UCLA sample has more patients diagnosed as dysthymic disorder and adjustment disorder. Future directions in cross-cultural psychiatric research are also suggested.

Adult↗

Determination of leukocyte elastase concentration in plasma and serum by a simple method using a specific synthetic substrate.

The concentration of leukocyte elastase (ELP) in plasma and serum was determined by an amidolysis method using a specific synthetic substrate for ELP, Suc-Ala-Tyr-Leu-Val-pNA. Results were compared with those using ELISA. ELP levels in plasma from healthy donors were similar to those determined by ELISA; however, the levels in serum were lower than those determined by ELISA. Correlation coefficients of ELP levels in plasma and serum as measured by the two methods were 0.75 (amidolysis) and 0.90 (ELISA). On the other hand, the correlation coefficient between serum ELP by the two methods was 0.83. Half of the ELP levels in plasma from 150 patients and serum from 400 patients were significantly elevated when compared with those from healthy donors, and the ELP elevation determined by amidolytic assay correlated with some variables in blood, namely fibrin(ogen)-degraded products, fibrinogen, GOT, GPT, gamma-GTP, LDH and leucine aminopeptidase. Despite the fact that the amidolysis method detects the alpha 2-macroglobulin-ELP complex while ELISA detects the alpha 1-antitrypsin-ELP complex, a comparative study showed amidolysis to provide sufficiently sensitive measurement of both plasma and serum ELP.

Adult↗

Amino acids and peptides. XXX. Synthesis of eglin c (41-49) and eglin c (60-63) and examination of their inhibitory activity towards human leukocyte elastase, cathepsin G, porcine pancreatic elastase and alpha-chymotrypsin.

H-Ser-Pro-Val-Thr-Leu-Asp-Leu-Arg-Tyr-OH and H-Thr-Asn-Val-Val-OH, which correspond to the sequences 41-49 and 60-63 of eglin c, respectively, were synthesized by a conventional solution approach using the newly developed 6-chloro-2-pyridyl ester method. The inhibitory activities of the above two peptides against human leukocyte elastase, cathepsin G, porcine pancreatic elastase and alpha-chymotrypsin were examined in comparison with those of the corresponding methyl esters.

Amino Acid Sequence↗

[Determination of zinc in very small body hair samples by one-drop flame atomic absorption spectrophotometry].

A method for determination of zinc contents in very small samples of hair was developed in order to estimate the zinc concentration in the human body. All steps from weighing of samples to ashing and preparation of the test solution were done in a tube designed by us to prevent contamination and to improve handling. Zinc concentration was determined with flame atomic absorption spectrophotometry aspirating a small volume of samples (80 microliters), by the so-called "one-drop method". Using this method, 5 mg of whiskers was analyzed every day for 10 days, and this revealed that the fluctuation of the zinc concentration level was very small and that it was possible to trace the individual level of zinc concentration daily. A sample of 5 mg is enough for the application of this method. Zinc concentration in the hair under the temple of a boy, and even the low-level zinc content of patients receiving total parenteral nutrition could be accurately determined every 10 days and monthly, respectively. The level of hair zinc contents for neonates was similar to that of adults.

Adult↗

Thickening at the root of the superior mesenteric artery on sonography: evidence of vascular involvement in patients with cancer of the pancreas.

Thickening of the root of the superior mesenteric artery (SMA) was studied by using preoperative sonography in 23 patients with pancreatic cancer and in 10 healthy control subjects. Of the 23 with cancer, 11 had neoplastic involvement of the SMA and 12 did not. Prominent thickening of the area around the SMA with (six patients) or without (five patients) decreased echogenicity compared with the adjacent retropancreatic connective tissue was observed in patients with involvement of the SMA, a finding called the "cuff sign." Mean thickness of the periarterial area in the cancer patients with and without involvement of the SMA and in control subjects were 8.5 mm, 4.0 mm, and 2.9 mm, respectively. With an upper limit of normal of 7.0 mm for the thickness of the SMA, the sensitivity, specificity, and overall accuracy of this sign in the evaluation of involvement of the SMA were 91%, 100%, and 96%, respectively. Decreased echogenicity of the periarterial area was not observed in patients without involvement of the SMA or in control subjects. Our results show that sonographic evidence of periarterial thickening of the root of the SMA (cuff sign), especially with decreased echogenicity, is a reliable finding of tumor infiltration of the SMA in patients with pancreatic carcinoma.

Adult↗

Emergence of symmetry in a visual conditional discrimination by chimpanzees (Pan troglodytes).

In Exp. 1, three young chimpanzees were trained to match red to a cross and green to a circle in an arbitrary matching-to-sample task. After acquisition of this task, they were tested for the emergence of associative symmetry of these conditional relations using the trials on which shapes were presented as samples and colors as comparisons. One of the three chimpanzees showed statistically significant accuracy on these test trials. This successful subject served in Exp. 2, in which an auditory-visual stimulus appeared contingent upon red and a cross while another auditory-visual stimulus was contingent upon green and a circle. This subject showed higher accuracies in symmetry tests than in Exp. 1, which suggested the facilitative effects of these events common to sample and correct comparison on the development of symmetry. In Exp. 3, subsequent tests in which only these stimuli were presented as samples indicated that these stimuli might have become the members of equivalence classes.

Animals↗