Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 685 records · Page 38Linked to original sources

PubMed1993

Connection of atopic disease in Japanese patients with juvenile dermatomyositis based on serum IgE levels.

Serum IgE levels of 22 patients with juvenile dermatomyositis (JDMS), 44 normal children, and 43 patients with adult dermatomyositis were compared. The geometric mean of serum IgE levels was significantly higher in the juvenile patients when compared with normal children (p < 0.01) and adult patients (p < 0.01). Of the 22 patients with JDMS, 11 (50%) had elevated serum IgE levels accompanied by atopic disease. Dermatomyositis was accompanied by atopic dermatitis (AD) in 9 (41%) of these 22 patients, a high prevalence when compared with reports among the general population. Following the appearance of muscular symptoms in JDMS patients with AD, the ratio of OKT4 to OKT8 cells rose due to a reduction in the percentage of OKT8-positive cells, along with further elevations in serum IgE levels and intractable cutaneous manifestations of dermatomyositis. All this may be a result of an interaction between the immuno-mechanism of this disease and that of AD. We suspect that, in general, children with impaired cell-mediated immunity, presenting with such symptoms as AD, may have a higher tendency for developing JDMS.

Adolescent↗

PubMed1993

Present and future status of noninvasive selective deep heating using RF in hyperthermia.

To achieve hyperthermia using electromagnetic energy, RF of under 100 MHz is basically suitable for the external heating of the deep portions of the body. For applicators using such RF, the following types are considered: capacitive, inductive, radiative and hybrid. With radiative applicators, the intensity of the EM waves radiated from the applicator decreases with propagation into the material to be heated, but the phased annular array of radiative applicators potentially increases the intensity of the EM energy in the deep portion owing to the interference of the waves. Using this method, the focusing of EM energy depends on the dielectric properties of the material to be heated. With respect to RF heating at a lower frequency than the RF used for the annular phased array, some devices have been said to concentrate EM energy in the deep portions, where the characteristics of 'wave' are not utilised. To this end, some methods using capacitive electrodes, an inductive coil, or a combination of both, are being designed. The results of using such methods have shown that it is possible to supply sufficient EM energy to the muscle layers deep in the material to be heated, without heating the fat layers excessively.

Humans↗

PubMed1993

Studies on transmission of hepatitis C virus from mother-to-child in the perinatal period.

To elucidate whether breast milk, vaginal discharge and contamination with maternal blood at birth are possible routes of mother-to-child transmission of hepatitis C virus (HCV), we examined HCV RNA in the cord and peripheral blood of infants, and in the blood, vaginal discharge, and breast milk of anti-HCV seropositive mothers. From July 1991 to July 1992, we studied 20 healthy pregnant women, who were seropositive with the Ortho anti-HCV EIA, and their infants. Using a sensitive nested polymerase chain reaction (nested PCR), we investigated the presence or absence of hepatitis C virus in the above-mentioned specimens. Moderate elevation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was observed in only one woman in the first and third trimesters. The nested PCR and subsequent Southern hybridization detected 0.5-5.5 copies of HCV c-DNA. HCV RNA was detected in 17/20 blood samples (85%), 7/14 vaginal discharge samples (50%) and 4/10 cord blood samples (40%). However, no HCV RNA was identified in the peripheral blood of infants or breast milk. The mother-to-child transmission of HCV at delivery or via breast milk does not appear to contribute much to maintaining the global HCV reservoir.

Adult↗

PubMed1993

Clastogenic activity of sodium fluoride in great ape cells.

Conflicting evidence has been reported concerning the mutagenicity of sodium fluoride (NaF), especially clastogenicity at concentrations of more than 1 mM. NaF is known to induce chromosome aberrations at these concentrations in human cells, but not in most rodent cells. We considered that such species-specific difference in chromosomal sensitivity would be derived from the phylogenetic distance between rodents and man. To clarify the role of interspecies differences, we investigated the chromosomal sensitivity to NaF in cell lines from various primates, which diverged into many species, including rodent-like prosimians and human-like great apes. The results showed that the clastogenicity of NaF was limited to human and great ape cells.

Animals↗

PubMed1993

Phenotypes of lymphocytes infiltrating non-small cell lung cancer tissues and its variation with histological types of cancer.

We investigated surface markers of lymphocytes infiltrating four different histological non-small cell lung cancer tissues obtained at surgery and the corresponding peripheral blood lymphocytes (PBL) of 40 clinical cases, who had undergone no prior anti-cancer treatment, by flowcytometry. In estimation of the mean proportion of each lymphocyte subset, a paired Wilcoxon test revealed that tumor-infiltrating lymphocytes (TIL) exhibited significantly higher values of CD3+ cells (P < 0.05), CD8+ cells (P < 0.05) and CD20+ cells (P < 0.01), and lower value of CD16+cells (P < 0.05), as compared with those in PBL. The Spearman test revealed that none of the values of surface markers in TIL statistically correlated with those in the corresponding PBL (r < 0.6, P > 0.05). Although there was no significant difference between the mean CD4/CD8 ratio of total TIL and that of PBL, TIL of 12 patients with squamous cell carcinoma almost always showed lower values of CD4/CD8 ratio than those in PBL (P < 0.05), while the CD4/CD8 ratio was similar between TIL and PBL in adenocarcinoma. These results suggest that TIL of lung cancers represent specific immunological responses, whose characteristic depend on the histological types of lung cancers.

CD4-CD8 Ratio↗

PubMed1993

A model for cell killing by continuous heating.

Based on an analysis of cellular survival curves following single heating, a model is proposed to explain the action of heat on cell survival. The basic idea of this model is that cellular inactivation by heat is a three-step process. In the first step, heating produces sublethal damage. Secondly, the produced damage is repaired in a certain time period after the cell has received it. The time period to be required for repairing the sublethal damage changes with the thermal conditions that the cell has undergone. In the third step, the lethal event is induced when the cell undergoes cumulative sublethal damage to the extent that it cannot be repaired. The incidence of sublethal damage is calculated using the Arrhenius equation, where one inactivation energy is postulated. Based on the assumption that sublethal damage occurs at random, a mathematical model has been worked out that quantitatively describes cell killing by single heating. This mathematical model has been applied to the surviving fractions of Chinese hamster ovary cells reported by Sapareto, and it correlates to the whole surviving data at a temperature range of from 41.5 to 46 degrees C by the substitution of the appropriate values for the parameters of the model.

Animals↗

PubMed1993

MR imaging of vertebral metastases: evaluation of fat saturation imaging.

OBJECTIVE: To compare conventional T1-weighted imaging (SE-T1) and chemical shift fat-saturation T1-weighted imaging (FS-T1) in the diagnosis of bone metastases. SUBJECTS: Twenty-two patients (101 vertebrae) with non-neoplastic lesions (Group 1) and 21 patients (72 vertebrae) with spinal metastases (Group 2) were evaluated with both images. RESULTS: The signal intensity (SI) distribution of Groups 1 and 2 on SE-T1 showed various patterns, and SI measurement was not significantly different between the two groups. On FS-T1, all non-neoplastic lesions had a low-intensity homogeneous appearance; however, the metastases had mixed to high SI. The SI measurement data of Group 2 was significantly (P < 0.0001) higher than that of Group 1. CONCLUSION: FS-T1 was useful in evaluating vertebral metastases.

Adult↗

PubMed1993

Quantification of occlusive and reperfused myocardial infarct size with Gd-DTPA-enhanced MR imaging.

The potential of Gd-DTPA-enhanced magnetic resonance imaging (MRI) for measuring infarct size was assessed in canine hearts. Twelve dogs underwent pre- and post-contrast MR imaging before and after recanalization. Infarct area was identified by triphenyltetrazolium chloride (TTC) staining of postmortal specimens in each case. Recanalization was complete in 10 dogs. High SI area was seen after reperfusion in nine of them; and it showed low signal intensity before reperfusion in seven of them. Two dogs were killed during reperfusion period: neither of them showed a low SI area before reperfusion. Necrotic regions were confirmed by TTC staining in seven of 12 dogs. Both the visual and quantitative assessment (n = 7) indicated that the extent of the low SI area before reperfusion was approximately the same as that of the necrotic region shown by TTC staining, while the high SI area seen after reperfusion was obviously larger than both the necrotic region and the low SI area on pre-reperfusion images. The correlation coefficient between low SI area and necrotic area was 0.98, and between high SI area and necrotic area was 0.80. These results suggest that Gd-DTPA-enhanced MRI may be useful for quantification of infarct size in occlusive myocardial infarction but it may overestimate in reperfused one.

Animals↗

PubMed1993

Seroepidemiological survey of human T-lymphotropic retrovirus among indigenous populations in Taiwan.

The prevalence of human T-lymphotropic retrovirus (HTLV) was examined in Taiwan's indigenous populations. In all, 797 healthy subjects in Taiwan including Han Chinese and nine indigenous populations (Ami, Atayal, Bunun, Saisiat, Paiwan, Puyuma, Rukai, Tsuo, and Yami) were examined for the presence of antibodies to HTLV by particle agglutination, indirect immunofluorescence and Western blot test. Two seropositive cases were found in this screening. One Saisiat male and a Han Chinese female were seropositive for HTLV. The Western blot profile indicated the virus was type-1 HTLV.

Adult↗

PubMed1993

Crystallization and preliminary X-ray study of Agkistrodon halys blomhoffii phospholipase A2 complexed with a specific inhibitor.

Phospholipase A2 from the venom of Agkistrodon halys blomhoffii has been crystallized as a complex with a specific inhibitor, (S)-2-dodecanoyl-amino-3-hexanol-1-phosphoglycol. The complex crystals belong to the hexagonal space group, P6(1)22 (or P6(5)22), with cell dimensions of a = b = 61.13 A, and c = 173.15 A. The diffraction extends to at least 2.3 A resolution.

Animals↗

PubMed1993

Molecular dynamics simulation of 1,2-dilauroyl-L-phosphatidylethanolamine binding to phospholipase A2: an attempt to explain the selective hydrolysis of substrate fatty acid ester at position 2.

To improve our understanding of why phospholipase A2 (PLA2) specifically catalyzes the hydrolysis of the fatty acid ester bond at position 2, not at position 1, of 1,2-diacyl-3-sn-phosphoglycerides, the binding of each fatty acid chain of 1,2-dilauroyl-L-phosphatidyl-ethanolamine (DLPE), a natural substrate, to bovine pancreas PLA2 was examined by molecular dynamics (MD) simulations. Two different binding modes were considered, i.e., the respective hydrocarbon chains of 1- and 2-lauroyl fatty acid esters were located at the PLA2 binding sites usually observed in the complex crystals (Form A2) and at the reverse sites (Form A1). Although the total energies of both forms fluctuated within nearly the same range during the 80 ps MD simulations, the binding mode of DLPE to the PLA2 catalytic site through the coordination to Ca2+ was much more advantageous in Form A2 than that in Form A1; significant deviation of the Ca2+ position from its starting structure was observed in the MD simulation of Form A1. The result suggests the importance of Ca2+ in the selective recognition and catalytic function of PLA2 toward the 2-positioned fatty acid ester of phosphoglyceride substrates.

Animals↗

PubMed1993

Massive chondroid differentiation in fibrous dysplasia of bone (fibrocartilaginous dysplasia)

Eight cases of fibrocartilaginous dysplasia (fibrous dysplasia with massive cartilaginous differentiation) of bone are reported. The age of the patients ranged from 4 to 26 years, with an average of 17.5 years. The male/female ratio was 1:1. In two patients the lesions occurred in a setting of polyostotic fibrous dysplasia. The anatomic sites most frequently affected were the femur and tibia. The proximal femur was the most common site. Roentgenograms showed well-demarcated lucent lesions of ground-glass opacity. In addition, stippled or ring-like calcifications suggesting cartilaginous elements were seen in six cases. Histologically, hyaline cartilage islands were found in juxtaposition to a fibro-osseous lesion characteristic of fibrous dysplasia. Enchondral ossification was commonly seen, frequently showing columnar arrangement of cartilage cells mimicking a growth plate. The cartilage may show moderate atypism. The important thing is to recognize the benign nature of chondroid elements in fibrous dysplasia. Even if cartilage dominates the histologic picture, it is important to identify the fibro-osseous elements and thereby avoid the misdiagnosis of chondrosarcoma.

Adolescent↗

PubMed1993

Platelet calcium handling in spontaneously hypertensive rats and in three strains of normotensive rats.

OBJECTIVES: Abnormalities in platelet calcium handling have been reported in spontaneously hypertensive rats (SHR) compared with Wistar-Kyoto (WKY) rats. Furthermore, several reports have indicated that WKY rats differ from both SHR and Wistar rats. The objectives of the present study were to investigate platelet calcium handling in three normotensive stains and in SHR, and to confirm the abnormal calcium mobilization in SHR. DESIGN AND METHODS: We compared calcium handling in fura-2-loaded platelets of SHR, Wistar, Sprague-Dawley (SD) and WKY rats. RESULTS: The basal cytosolic free Ca2+ concentration in platelets was significantly higher in SHR and significantly lower in SD rats than in the other strains. The intracellular Ca2+ response to thrombin in the presence of extracellular Ca2+ was greater in SHR than in the three normotensive strains. The thrombin-induced intracellular Ca2+ rise in the absence of extracellular Ca2+ was also greater in SHR and lower in SD rats than in and Wistar rats at higher doses of thrombin. The intracellular ionomycin-released calcium fraction, which may indicate the size of intracellular calcium stores, was similar in SHR, WKY and Wistar rats, and was greater than in SD rats. No difference was detected between WKY and Wistar rats in resting and peak agonist-evoked intracellular Ca2+ concentrations. CONCLUSIONS: These results show that calcium handling in WKY rats is similar to that in Wistar rats with respect to platelet calcium metabolism and confirm the abnormality in SHR. Furthermore, the enhanced intracellular Ca2+ response to thrombin in SHR was not dependent on the size of ionomycin-released Ca2+ stores. In addition, substantial differences in platelet calcium handling may occur even among normotensive strains if the strains are not related.

Animals↗

PubMed1993

Na(+)-Ca2+ exchange modulates Ca2+ handling of human platelets by altering intracellular Ca2+ store size.

OBJECTIVE: In order to elucidate the role of Na(+)-Ca2+ exchange in regulating cytosolic free Ca2+ concentration in human platelets, we investigated the relationship between cytosolic free Na+ and Ca2+ concentrations in human platelets. METHODS: Sodium-binding benzofuran isophthalate and fura-2 were used to monitor cytosolic free Na+ and Ca2+ concentrations, respectively. RESULTS: Ouabain at a concentration of 100 mumol/l induced an increase in cytosolic free Na+ concentration within 5 min, followed by increases in resting cytosolic free Ca2+ concentration and intracellular Ca2+ store. These three parameters were increased in a time-dependent manner significantly above the timed control over a period of 60 min. Pre-incubation of platelets with 100 mumol/l ouabain for 30 min significantly enhanced the cytosolic free Ca2+ response to thrombin and arginine vasopressin in the absence of extracellular Ca2+. The decrease from peak cytosolic free Ca2+ concentration in response to ionomycin in the absence of extracellular Ca2+ was significantly slower in low-Na+ buffer than in standard buffer. In addition, 5 mumol/ionomycin increased the cytosolic free Na+ concentration markedly in the presence of 0.1 mmol/l extracellular Ca2+, but the rise in cytosolic free Na+ concentration was suppressed by 2 mmol/l Ni2+ (NiCl2) or by removal of extracellular Ca2+. CONCLUSIONS: These results suggest that Na(+)-Ca2+ exchange is important in extruding Ca2+ from the cytosol in human platelets, and inhibition of this exchange leads to the accumulation of intracellular Ca2+ store, which may be responsible for the enhanced responsiveness of cytosolic free Ca2+ to agonists.

Blood Platelets↗

PubMed1993

An RF concentrating method using inductive aperture-type applicators.

A method for concentrating em energy of a low frequency in hyperthermia is proposed. The phantom together with boli are placed between a pair of inductive aperture-type applicators. The calculated results show that the method can heat the deep portion of the phantom without overheating the fat layers excessively.

Adipose Tissue↗

PubMed1993

Analysis of lymphocyte subpopulations in peripheral blood in adult and juvenile cases of dermatomyositis.

Dermatomyositis, recognized as an autoimmune disorder, occurs not only in adults but also in children. In this study, we evaluated lymphocyte subpopulations in the peripheral blood of 24 adult dermatomyositis and 14 juvenile dermatomyositis patients and in 17 healthy adults and 9 healthy children by flow cytometry using monoclonal antibodies. When compared with healthy adults and adult patients with inactive dermatomyositis, the adult patients with active disease had significantly lower percentages of CD3+ and CD8+ cells and a significantly higher percentage of CD20+ cells. In contrast, juvenile dermatomyositis patients had lymphocyte subpopulations not significantly different from those of healthy children; the activity/inactivity of disease did not make any difference. These results support our hypothesis that adult and juvenile dermatomyositis may be diseases of entirely different scope.

Adult↗

PubMed1993

Effect of mass screening for breast cancer from the aspect of psychosocial assessment of the quality of life.

To assess the quality of life (QOL) in patients with breast cancer receiving mass screening, a collaborative matched case-control study was conducted in nine hospitals throughout Japan. A total of 122 patients detected by mass screening (study group) and 226 patients found in out-patient clinics (control group) were assessed psychosocially on the basis of questionnaire information. The incidence of patients with early stage breast cancer was significantly higher in the study group than in the control group (P < 0.05). Chest wall pain was observed in 35.2% of the study group and in 46.5% of the control group (P < 0.05). Although control patients were more optimistic than study group patients, disturbed daily life and anxiety about recurrence were a little more frequent in the former group than in the latter. In particular, shoulder stiffness was frequently seen in the control group (P < 0.05). Early detection and information do not create anxiety in mass screening patients (P < 0.01). We should recommend mass screening to patients to detect early stage breast cancer and provide better QOL.

Activities of Daily Living↗

PubMed1993

Encapsulated papillary carcinoma of the thyroid gland: clinicopathological and cytofluorometric study in comparison with non-encapsulated papillary carcinoma.

Clinicopathological and cytofluorometric studies were performed on nine encapsulated (EPC) and 23 non-encapsulated (non-EPC) carcinomas of the thyroid gland. The average age of the patients with EPC was 33 years, which was significantly younger than that of those with non-EPC. The average tumor size of EPC was twice as large as that of intraglandular non-encapsulated carcinoma. All patients with EPC were alive without disease, but three out of 23 patients with non-EPC had a recurrence of the disease or died. Cytofluorometric studies showed that the mean nuclear DNA content and percentage of tumor cells in the S-G2M phase of EPC were lower than that of non-EPC. According to the DNA histogram pattern, all EPC showed distinct modal DNA values in the diploid or near diploid region of normal cells. However non-EPC, especially extra-glandular non-encapsulated papillary carcinoma, showed a wide variety of DNA histogram patterns. The present study suggested that EPC is a distinct subtype of papillary carcinoma of the thyroid gland clinicopathologically and that cytofluorometrically it is different from non-EPC.

Adult↗