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Biomedical subjects

Y Ishida

Publications and source records attributed to Y Ishida.

At least 523 records · Page 29Linked to original sources
PubMed1989

[Regional left ventricular diastolic function in hypertrophic cardiomyopathy: application of "sector analysis" to ECG forward and reverse gated radionuclide ventriculography].

To estimate regional left ventricular (LV) diastolic filling patterns in hypertrophic cardiomyopathy (HCM), a computer-assisted method by applying "sector analysis" to ECG forward and reverse gated radionuclide ventriculography was developed. Fourteen patients with HCM (four with localized septal hypertrophy, seven with apical hypertrophy and three with septal and apical hypertrophy according to echocardiography) were observed at rest. After establishing serial 20 msec imaged frames, the LV region of interest was subdivided into eight sectors radiating from the geometric center. A time-activity curve was generated for each sector and was fitted by third-order harmonics of the Fourier series. From each fitted curve, the regional peak filling rate (rPFR) and the time of rPFR (rTPFR) in the forward gating method and regional atrial contribution to filling (rAC/FV) in the reverse gating method were calculated. The coefficient of variance of rTPFR was used as an index of LV diastolic asynchrony. In HCM, a prominent delay of rTPFR was observed in the hypertrophied regions. The coefficient of variance of rTPFR correlated inversely with global LVPFR (r = -0.62, p less than 0.05), indicating that diastolic asynchrony is one of the determinants of the LV early filling rate. Regional AC/FV was augmented in the hypertrophied regions, indicating the important role of atrial systolic LV filling for slowed early filling. Thus, this new method provides valuable information concerning regional diastolic LV wall mechanics in HCM.

Adult↗
PubMed1989

Evidence for compartmentation of high energy phosphagens in smooth muscle.

Despite the lack of a clear understanding of the exact mechanisms involved, our results show that ATP and PCr in the taenia do not distribute in a manner predicted by the equilibrium of the Lohmann reaction in a single uniform compartment. Our results may be of significance to the understanding of regulation of metabolism and its coordination with the various ATP-dependent cellular functions. This may be particularly relevant to smooth muscle in which oxidative and glycolytic components of metabolism are known to be independently regulated (Lynch and Paul, 1987). Presumably, our results will be of significance for pathophysiological issues such as ischemia of intestine as well as other smooth muscles.

Adenosine Triphosphate↗
PubMed1989

[A case of gastric carcinoid tumor with coexisting adenocarcinoma in the same tumor].

A case of a gastric carcinoid tumor with a coexisting adenocarcinoma in the same tumor is reported. The patient was a 71-year-old man who complained of epigastralgia. His physical examination and routine laboratory data were unremarkable. An upper GI x-ray series and the gastroendoscopic findings, however, demonstrated a Borrmann 2-like tumor of the antrum. An endoscopic biopsy specimen from the tumor revealed that it was a gastric adenocarcinoma. Therefore, a subtotal gastrectomy with a lymph node dissection was performed. The resected specimen showed a Borrmann 2-like tumor, but also that infiltration was limited to within the submucosal layer. The pathological findings revealed that the tumor contained two differential component structures (a carcinoid and an adenocarcinoma). The carcinoid and adenocarcinoma structures coexisted with transitional changes that connected both structures. Pathohistologically, it was thought that these two differential components developed from a common origin.

Adenocarcinoma↗
PubMed1989

[A case of acute mixed leukemia with expression of J5 and GPIIb/IIIa complex by ABC method].

Identification of the lineage and maturation stage of the leukemic cells is essential for the diagnosis, treatment and followup of acute leukemia. Staining of blood smear by avidin-biotin-peroxidase complex method, which requires no special equipments, enables to observe both morphology and surface antigens at the same time. Simultaneous expression of a B-lymphocyte antigen J5 and a platelet antigen GP IIb/IIIa complex on the same blasts was demonstrated by this technique in the present case.

Acute Disease↗
PubMed1989

[Cross and non-cross resistant anticancer agents to multidrug-resistant cultured cells from hematologic malignancies].

We report here that typical and atypical multidrug resistant (MDR) cells can be identified by monoclonal antibodies, MRK16 and MRK20, respectively. Typical MDR cells were cross-resistant to vinca alkaloids, anthracyclines, mitoxantrone (MXT), etoposide (VP-16) and actinomycin-D (ACT-D), and reactive to MRK16. Atypical MDR cells were cross-resistant to anthracyclines, MXT, VP-16, and bleomycin but sensitive to vinca alkaloids and ACT-D. They were reactive to MRK20, but not to MRK16. Among anthracyclines, aclacinomycin A was not cross-resistant to either typical or atypical MDR cells. Methotrexate was not cross-resistant to doxorubicin, vincristine, Ara-C and cisplatin. Cisplatin was not cross resistant to 5-FU, either. Identification of cross and non-cross resistant anticancer agents may be useful to plan a cure-oriented combination chemotherapy for hematologic malignancies.

Antibodies, Monoclonal↗
PubMed1989

[Hodgkin's disease under twenty years of age--clinicopathological study].

Twenty two cases with Hodgkin's disease under 20 years of age who were diagnosed and treated in National Cancer Center during 1962-1986 were studied retrospectively. The most common initial symptom was swelling of lymph nodes (86%) and only 5 cases (23%) showed "B" symptoms. Laboratory findings showed that there were some cases with increased WBC counts but only 2 cases with an elevated LDH value. In 2 out of 4 cases serum copper value correlated well with their clinical state. Histologically lymphocyte predominance type, mixed cellularity type and nodular sclerosis type almost equally occurred in children younger than age 15 years. On the other hand nodular sclerosis type with mediastinal mass was predominantly encountered in older patients (especially female). The ten years' survival rate in stage I and II patients was 59% compared with 21% in stage III and IV patients. As for the results of initial treatment, complete remission and 10 years' survival rate were 91% and 87% in recent 12 years (1975-1986) compared with 55% and 36% in the preceding 13 years (1962-1974) respectively. Autopsy findings revealed rare involvements of the central nervous system and kidneys. Various late effects which may be caused by escalating doses of radiotherapy occurred in 6 out of 9 cases under the age of 15 years who survived. On the basis of these results lower-doses of radiotherapy combined with systemic chemotherapy appeared to be advisable for the treatment of childhood Hodgkin's disease.

Adolescent↗
PubMed1989

Chemotherapeutic efficacy of ofloxacin against experimental pneumonia with Pseudomonas aeruginosa in guinea pigs.

The chemotherapeutic efficacy of ofloxacin against experimental pneumonia was investigated with special reference to its treatment regimen. A pneumonia model was successfully produced by inhalation of a virulent strain of Pseudomonas aeruginosa in guinea pigs immunosuppressed with cortisone acetate. One or 4 days after infection, the animals were treated orally with the fixed daily doses of ofloxacin either once a day or thrice a day for 3 consecutive days. Ofloxacin given thrice a day eliminated the organisms from the lung more efficiently than the equivalent total doses injected once a day in both series of treatment, starting 1 or 4 days after infection. The superiority of the triple dosing in chemotherapeutic efficacy of ofloxacin was found to be attributable at least to the longer retention of its pulmonary levels exceeding the antibiotic concentrations.

Animals↗
PubMed1989

[Problems entailed in the definition and pathology of anaplastic astrocytoma].

Three-tiered system dividing supratentorial astrocytic neoplasms into the astrocytoma, anaplastic (malignant) astrocytoma and the glioblastoma multiforme has been widely used. However, the pathology of anaplastic astrocytoma is defined in different ways according to different classifications. A total of 42 biopsy specimens from 35 cases diagnosed as anaplastic astrocytoma were reviewed pathologically and their features were correlated with a follow-up clinical study to discuss the prognostic usefulness of the subdivision of anaplastic astrocytoma. In WHO classification, anaplastic astrocytoma is defined as "astrocytoma containing areas of anaplasia". Follow-up study of 7 cases with the histology as such revealed that 5 cases had survived more than one year and seven months. The other 28 cases showed a varied histology and were subclassified into an astrocytoma in which moderately anaplastic cells are found throughout the tumor, an astrocytoma formed by anaplastic fusiform cells, an astrocytoma composed of predominantly rounded anaplastic cells, and a pleomorphic astrocytoma with or without intracytoplasmic hyaline inclusions. A follow-up study of cases with these types of astrocytoma disclosed death in 15 cases within one year and 7 months following the first surgery and that three cases displayed typical histological features of glioblastoma at autopsy. It is considered that there would be a considerable overlap between the group of anaplastic astrocytoma and that of glioblastoma, if we use the term "anaplastic astrocytoma" in a broader category.

Adolescent↗
PubMed1988

Regulation of metabolism and contraction by cytoplasmic calcium in the intestinal smooth muscle.

Reduced pyridine nucleotides (PNred) and oxidized flavoproteins (FPox) were measured fluorometrically in the intestinal smooth muscle strip of guinea pig taenia caeci simultaneously with contractile tension. Cytoplasmic free Ca2+ levels ([Ca2+]cyt) were also measured by a fura-2-Ca2+ fluorescence technique. PNred, FPox, and [Ca2+]cyt increased during spontaneous contraction or upon the addition of high K+ or carbachol and decreased upon the removal of these stimulants. [Ca2+]cyt increased before the increase in muscle tension. PNred increased almost simultaneously with or immediately after the onset of contraction, while FPox increased before the initiation of contraction. Both PNred and FPox decreased a few seconds after the initiation of relaxation. In the K+-depolarized, Ca2+-depleted muscle, graded elevation of external Ca2+ increased PNred, FPox, and muscle tension. The sensitivity to Ca2+ was in the order of FPox greater than PNred greater than muscle tension. Changes in PNred were inhibited when glycolysis was inhibited by substitution of external glucose with oxaloacetate, pyruvate, or beta-hydroxybutylate, but not when oxidative phosphorylation was inhibited by N2 bubbling or by NaCN. In contrast to this, changes in the FPox were inhibited by N2 bubbling or NaCN, but not by the inhibition of glycolysis. These results suggest that an elevation of intracellular Ca2+ activates carbohydrate metabolism and contractile elements independently, resulting in the reduction of cytoplasmic pyridine nucleotides, oxidation of mitochondrial flavoproteins, and development of tension in the intestinal smooth muscle.

Anaerobiosis↗
PubMed1988

Heterogeneity of lymphocyte calcium metabolism is caused by T cell-specific calcium-sensitive potassium channel and sensitivity of the calcium ATPase pump to membrane potential.

Calcium management differs in T and B lymphocytes. [Ca2+]i elevation in response to calcium ionophores is up to 10 times greater in T cells than B cells. There is no difference between them in ionophore uptake. T cells, but not B cells, possess a calcium-sensitive potassium channel which produces membrane hyperpolarization at [Ca2+]i above 200 nM. This alters T cell density providing a rapid and easy method of cell separation. In contrast, B cells depolarize when [Ca2+]i is increased. Isolated B cell membrane vesicle ATP-dependent calcium pump activity is higher than T cell vesicles. Membrane depolarization reduces the [Ca2+]i response to ionomycin, most dramatically in T cells because they are hyperpolarized by increased [Ca2+]i. The most likely basis of this behavior is an effect of membrane potential on lymphocyte membrane calcium pump activity. This mechanism provides an explanation of the inhibitory effect of membrane depolarization on T lymphocyte responses.

Animals↗
PubMed1988

Possible involvement of 1 alpha,25-dihydroxyvitamin D3 in proliferation and differentiation of 3T3-L1 cells.

Growth of 3T3-L1 cells was inhibited by 10(-10)-10(-7)M of 1 alpha,25-dihydroxy vitamin D3 [1 alpha,25(OH)2D3] in a dose- and time-dependent manner. The potency of 1 alpha,25(OH)2D3 in inducing differentiation was low, since 3T3-L1 cells cultured with 1 alpha,25(OH)2D3 did not become mature adipocyte-like cells but were changed to slightly rounded cells containing small droplet-like substances in the cytoplasm and glycerophosphate dehydrogenase (sn-glycerol-3-phosphate: NAD+2-oxidoreductase, EC 1.1.1.8), the marker enzyme of differentiation to adipocyte, did not increase. These results together with the natural occurrence of this vitamin indicate that 1 alpha,25(OH)2D3 may play an important role in the cell growth and differentiation besides such known action as intestinal calcium transport and bone mineral mobilization.

Animals↗
PubMed1988

Expression of functional interleukin-2 receptors in human light chain/Tac transgenic mice.

The growth of mature T lymphocytes is regulated by interaction between interleukin-2 (IL-2) and its receptor. Three distinct binding sites for IL-2, namely low- (Kd 10 nM), intermediate- (Kd 100 pM) and high- (Kd 10 pM) affinity sites, have been found on human and primate T lymphocytes. Chemical crosslinking of labelled IL-2 to human T cells shows that two polypeptide chains, p55 (L chain) and p75 (H chain), bind IL-2 with low and intermediate affinities respectively. The high-affinity binding was shown to arise from ternary complex formation of IL-2, L and H chains. Construction of mutants of the L-chain complementary DNA indicated that the L chain is not directly involved in growth signal transduction. Nevertheless, expression of the IL-2 receptor L chain is tightly regulated by antigen or mitogen stimulation. To investigate the L chain function, we have produced transgenic mice using human L-chain cDNA of the IL-2 receptor under the control of a constitutive promoter. Studies on the L-chain transgenic mice showed that functionally active IL-2 receptors with high affinity were expressed on unstimulated spleen and thymus cells. The results indicate that the H chain of the IL-2 receptor is constitutively expressed in T cells.

Animals↗
PubMed1988

Analyses of epididymal sperm surface antigens by monoclonal antibodies against hamster spermatozoa.

BALB/c mice were immunized with spermatozoa from cauda epididymides of hamsters and the immune spleen cells were fused with mouse myeloma cells (P3U1). Seven hybridomas (GHS-1,-2,-3,-4,-5,-6, and -7) that produced monoclonal antibodies (Mabs) binding to the epididymal spermatozoa were established. Three Mabs (GHS-3,-4, and -6) were IgM and the other four were IgG1. All Mabs reacted to hamster spermatozoa from cauda epididymides but none of the Mabs except GHS-5 and -7 reacted to spermatozoa in testis. GHS-5 and -7 Mabs bound to the acrosome region of spermatozoa in both testis and epididymis. The antigens corresponding to GHS-2, -4, and -6 Mabs appeared to be excreted from epithelial cells of caput epididymis, while those to GHS-1 and -3 Mabs seemed to be produced in cauda epididymis. Both groups of the antigens bound to the surface of spermatozoa during their epididymal transit. Immunoblotting analyses of epididymal fluid showed that the antigen epitopes corresponding to GHS-1,-2,-3,-4, and -6 Mabs were distributed to multiple components with different molecular weights ranging from over 100 to 25 kd. The distribution patterns of the epitopes corresponding to GHS-1 and -3 Mabs and GHS-2,-4, and -6 Mabs were very similar, respectively, but each group pattern was quite different from each other. GHS-5 Mab reacted to a component of sperm extract with a molecular weight of around 94 kd, while GHS-7 Mab failed to recognize any components transblotted.

Acrosome↗
PubMed1988

Dynamics of the spinal cord: an analysis of functional myelography by CT scan.

The antero-posterior movement of the spinal cord with flexion and extension of the neck was analyzed in order to clarify the mechanism of spinal cord compression in cases with postoperative spinal deformity, and to contribute to the improvement of the surgical methods of conventional laminectomy. The control subjects were 47 cases without cervico-thoracic neurological symptoms, who underwent CT myelography in flexion and extension of the neck; the cervical spinal cord was examined in 27 of these cases and the thoracic cord in the other 20. CT myelography was also carried out in 16 patients with cervical myelopathy and in 5 patients after posterior decompression surgery (suspension laminotomy). CT sections in flexion and extension of the neck were analyzed for 1) change of configuration of the dura mater and the spinal cord, and 2) antero-posterior shift of the spinal cord in the subarachnoid space. In the control subjects, the configuration of the dura mater was slightly flattened at C5/6, C6 and C6/7 in extension of the neck. The cervical spinal cord shifted anteriorly in flexion and posteriorly in extension of the neck, and was flattened at the midcervical level in flexion in the control subjects. There was a statistically significant correlation between the location of the spinal cord and the adjacent intervertebral angles at the levels of C4, C5 and C6. These results were compared with the results from the 16 patients with cervical myelopathy and 5 patients after suspension laminotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Immunohistochemical study of the early human fetal brain.

To assess the cytogenesis of the central nervous system we studied the spinal cord and the cerebrum in 11 human embryos and fetuses of gestation age 7-25 weeks immunohistochemically using anti-vimentin, anti-neurofilament protein (NFP), anti-neuron-specific enolase (NSE), anti-glial fibrillary acidic protein (GFAP), anti-S-100 protein, anti-Leu 7 and anti-myelin basic protein (MBP) antibodies. Vimentin was demonstrated in ventricular cells at 7 weeks and older. NFP-68-kDa and -160-kDa components were observed in neuroblastic cells of the neural tube at 7 weeks. NFP (68 and 160 kDa) was mainly located in the marginal zone of the spinal cord and the cerebrum at 8-9 weeks. NSE was not found in the neural tube at 7 weeks, although NSE was demonstrable at 9 weeks both in the spinal cord and in the cerebrum. GFAP-positive cells started to appear at 9 weeks in the spinal cord and at 15 weeks in the cerebrum, respectively. S-100 immunoreactivity was almost coincident with GFAP. S-100, however, was observed in more numerous glioblastic cells. Leu 7 was detected at 7 weeks and located in the neuropil of the central nervous tissue. MBP was not demonstrable in this study. Our study indicates that neuronal differentiation occurs much earlier than glial differentiation in the human brain and that neuronal and glial cell classes do not coexist in the ventricular zone of the early human fetal brain.

Brain↗
PubMed1988

Effects of a high concentration of CO2 on electrocardiograms in the carp, Cyprinus carpio.

1. The effects of a high concentration of CO2 (PCO2 = 250 mmHg and PO2 = 360 mmHg in water) and MS222 (tricaine methanesulfonate, 1/8000 or 1/5000) on the electrocardiogram (ECG) in carp were examined using five kinds of bipolar leads from the body surface. 2. In the carp anesthetized with the high concentration of CO2 for 30 min, the QRS duration, PQ interval and and direction of the QRS axis on the frontal plane significantly changed. Even after recovery from anesthesia, delay in the QRS duration was still recognized. 3. The concentration of CO2 used in this study had an anesthetic action to the same degree as 1/8000 of MS222 and had a much more severe effect on the ECG of the carp than 1/5000 of MS222.

Animals↗