Search PubMed⌕ Search

Biomedical subjects

Y Ishida

Publications and source records attributed to Y Ishida.

At least 577 records · Page 32Linked to original sources
PubMed1987

Suspension laminotomy: a new surgical technique for compression myelopathy.

In an attempt to eliminate the many negative aspects of conventional extensive laminectomy, we originated in 1981 and have developed a new surgical technique called "suspension laminotomy." A basic principle of this operation is preservation and repair of the soft and bony tissue of the spine with osseous enlargement of the spinal canal. Eighty-one patients were treated with suspension laminotomy. This operative technique can be applied to almost all segments of the spine and can be used for all cases that would usually have been treated with conventional extensive laminectomy. We emphasize the necessity of repairing paraspinal muscles and discuss the postoperative spinal deformities and the dural constriction, which seemed to be caused by scar formation after conventional laminectomy. Suspension laminotomy should minimize the negative aspects of conventional extensive laminectomy.

Adult↗
PubMed1987

Impaired ventricular relaxation during myocardial ischemia and after reperfusion in isolated perfused canine hearts.

The goal of this study was to investigate the mechanisms of impaired relaxation in ischemic and reperfused hearts without asynergic wall motion. To test the hypothesis that muscle elongation during ischemia does not improve the slowed relaxation, the time constant (T) of the isovolumic left ventricular pressure decay was obtained during volume loading in 14 isolated perfused canine hearts. In the nonischemic condition (coronary perfusion pressure: 107 +/- 3 mmHg), T progressively decreased as the peak left ventricular pressure was increased by volume loading. In contrast, in the ischemic condition (coronary perfusion pressure: 51 +/- 3 mmHg), T did not decrease despite an increase in peak left ventricular pressure by volume loading. These results indicate that during ischemia the impaired relaxation is not improved by an increase in preload. Moreover, reperfusion after a brief ischemia also increased T despite an increase in the contractile force, i.e., left ventricular pressure. The maximal change in the relaxation rate occurred much earlier than the maximal overshoot of the contractile force and coincided with an increase in coronary blood flow. These results indicate that prolongation of relaxation immediately after reperfusion is partly attributable to an increase in the electile force induced by the refilling of the coronary arteries. These mechanisms of impaired relaxation during ischemia and reperfusion may deteriorate ventricular filling and hence, cardiac output.

Animals↗
PubMed1987

[Effective radiation therapy of two cases of primary Ewing's sarcoma of the rib].

Two cases of primary Ewing's sarcoma of the rib are reported, in which radiation therapy was quite effective. Case 1 was an 18-year-old female who had had an operation and radiation therapy for Ewing's sarcoma of the left 7th rib. She was referred to our hospital after a recurrent tumor was found. Radiation therapy (tumor dose 46.2 Gy) and chemotherapy were given. The tumor disappeared and there has been no relapse for 1 year and 3 months after the treatment. Case 2 was a 2-year-old-infant. Radiation therapy (tumor dose 74 Gy) was given for primary Ewing's sarcoma of the left 6th rib. The tumor became small and was successfully removed at operation. There has been no relapse or distant metastasis for 8 months following the operation. We emphasize the importance of multidisciplinary treatment in case 1 and the usefulness of preoperative radiotherapy in case 2.

Adolescent↗
PubMed1987

Expression of lymphocyte-associated antigens on neoplastic angioendotheliomatosis.

Neoplastic angioendotheliomatosis (NAE) is a rare and fatal disorder and has been regarded as a multifocal in situ neoplastic change of endothelial cells. This report describes a case of NAE from whom a biopsy specimen was obtained and studied immunohistologically using several monoclonal antibodies against lymphocyte-associated antigens. The tumor cells occluding luminal space express both T and B cell markers such as Leu-1, Leu-3, Leu-10, Leu-M3, HLA-DR, and HLA-DQ, whereas they do not express Leu-2, Leu-4, lymphocyte-common antigen, and immunoglobulins. Factor VIII as a marker of vascular endothelial cell is false positive in the present case. Since immunoglobulins as a definitive B lymphocyte marker are negative in this case, there is no direct evidence indicating that NAE is a tumor of B lymphocytic lineage as previously reported. These results suggest the two possibilities that NAE is a unique variant of T cell lymphoma or true vascular endothelial tumor sharing the common histogenesis with malignant lymphoma. As it stands the former possibility is more likely than the latter in our case.

Adult↗
PubMed1987

Inverted papillary carcinoma of the urinary bladder.

A 47-year-old man presented with an inverted papillary carcinoma of the urinary bladder. Cystoscopy revealed an approximately 2 cm mass, with a small stalk and smooth surface, which was situated just medial to the right ureteral orifice. Transurethral resection of the tumor was performed on July 25, 1983. Malignant changes were recognized in the epithelial cords in the resected specimen. This is in contrast to the general view that inverted papilloma of the urinary bladder is benign in nature. The authors believe that careful pathologic examination should be done when an inverted type tumor of the urinary tracts is found. No recurrence has been recognized as of September 11, 1987.

Carcinoma, Papillary↗
PubMed1987

Effects of spontaneous respiration on right and left ventricular function: evaluation by respiratory and ECG gated radionuclide ventriculography.

To clarify the mechanism of inspiratory reduction of left ventricular (LV) stroke volume (SV) during spontaneous respiration, we measured right and left ventricular volume changes from expiration to inspiration using radionuclide ventriculography with respiratory gating technique. In this method, scintigraphic data were acquired in a list mode with ECG R wave triggers and respiratory volume curve derived from respiratory flowmeter. Cardiac cycles occurring during the second halves of inspiratory and expiratory phases were separately selected and used to produce multigated images for the respective phases. Twelve patients with normal LV ejection fraction (EF) (greater than 50%) and right ventricular (RV) EF (greater than 40%) and without pulmonary diseases were studied. LV end-diastolic volume (EDV) decreased during inspiration in all subjects (by 11 +/- 5%), whereas LV end-systolic volume (ESV) was insignificantly changed. Accordingly, LVSV decreased during inspiration in all subjects (by 17 +/- 7%). LVEF decreased from 64 +/- 6% during expiration to 60 +/- 6% during inspiration (p less than 0.001). In contrast to the left ventricle, RVEDV and RVSV increased during inspiration by 13 +/- 11% and 22 +/- 18%, respectively. RVESV did not change significantly. RVEF increased from 48 +/- 6% during expiration to 52 +/- 5% during inspiration (p less than 0.05). These results indicate that inspiratory reduction of LVSV during spontaneous respiration is due to a decrease in LVEDV which may be derived from an increase in RVEDV during inspiration through the mechanism of ventricular interdependence.

Aged↗
PubMed1986

Age-related change in serotonin-mediated prejunctional inhibition of rat vas deferens.

The effect of age on the serotonin (5-HT)-induced prejunctional inhibition of twitch contractions induced in rat vas deferens by single-pulse field stimulation at 0.1 Hz was studied. The inhibitory effect of 5-HT gradually decreased with increasing age of the rats (4-15 weeks old) and was no longer detectable in preparations from rats over 15 weeks old. Moreover, on a further increase in age to 45 weeks, 5-HT conversely enhanced the twitch response of the vas deferens. The 5-HT2 antagonists ketanserin and mianserin potentiated the 5-HT-induced inhibition of contractions of the vas deferens of young rats (8-15 weeks old), and attenuated the amplifying effect of 5-HT on the responses of preparations from old rats (95 weeks old). Thus unmasking of the inhibition depended on the age of rats. This change occurred earlier in life in the prostatic portion of the vas deferens than in the epididymal portion. A functional decrease in 5-HT-mediated prejunctional inhibition and the resultant increase in amplification of the twitch response by 5-HT are probably responsible for the age-related decrease in prejunctional inhibition.

Adenosine Triphosphate↗
PubMed1986

Age-related decrease in endothelium-dependent dilator response to histamine in rat mesenteric artery.

The effect of aging on the vasodilator responses to histamine, 2-pyridylethylamine and 4-methylhistamine of ring segments of rat mesenteric arteries were investigated. The maximal extent of histamine-induced dilatation of the arteries previously contracted with norepinephrine was greatest for arteries from rats aged 2 and 8 weeks. The maximal response decreased progressively with an increase in age to 13 and 56 weeks. Arteries from 99 week old rats scarcely responded to histamine. Under these conditions, the dilatation induced by papaverine showed no change with age. The vasodilatation caused by 2-pyridylethylamine and 4-methylhistamine also decreased age dependently. The dilatation of the arteries induced by these agents was inhibited by the H1-antagonist chlorpheniramine, but not by the H2-antagonist cimetidine. Removal of the endothelium completely abolished the vasodilator effect of histamine, leaving the effect of papaverine unaffected. Hydroquinone and methylene blue reversed the dilatation induced by histamine, without affecting that caused by papaverine. These results suggest that the age-related decrease in dilatation of rat mesenteric artery in response to histamine is mainly due to a decrease in the ability of the endothelium to liberate a mediator(s).

Aging↗
PubMed1986

Cellular basis of in vitro anti-DNA antibody production: evidence for T cell dependence of IgG-class anti-DNA antibody synthesis in the (NZB X NZW)F1 hybrid.

An in vitro system was designed to measure anti-DNA antibody synthesis, and the cellular basis of this autoantibody production in NZB X NZW (B/W)F1 (B/W F1) mice was analyzed. The spleen cells from old B/W F1 mice contained a number of B cells that spontaneously produced anti-DNA antibodies of both IgM and IgG classes in the absence of stimulants, thereby demonstrating that these B cells had been activated in vivo. These activated B cells could be removed by Sephadex G-10 column (G-10) filtration. Such G-10-passed, homogeneously small B cells were activated by the stimulant lipopolysaccharide (LPS) and produced both IgM and IgG class anti-DNA antibodies. The G-10-passed cells contained both B and T cells, and the cytotoxic treatment of the cells with monoclonal antibodies to T cells, anti-Thy-1 and anti-L3T4, abolished the LPS-induced IgG class, but not IgM class, anti-DNA antibody syntheses. Thus, the LPS-induced production of IgG class anti-DNA antibodies in B/W F1 mice is regulated by T cells. Reconstitution experiments revealed the requirement of T-B cell contact but not of the proliferative response of T cells. Moreover, there was no apparent adherent cell requirement. Such IgG class anti-DNA antibodies were produced only by spleen cells from old B/W F1 mice, but not from young B/W F1, NZB, NZW, and C57BL/6 mice. Like IgM class anti-DNA antibodies, LPS-induced synthesis of polyclonal IgM was T cell-independent. Only a slight reduction in the polyclonal IgG synthesis was observed after the G-10-passed cells had been treated with anti-Thy-1 antibody plus complement. This study should facilitate investigation of cell to cell interactions in the formation of autoantibodies and their correlations to immunologic abnormalities in autoimmune disease.

Animals↗
PubMed1986

T cells bearing unique membrane antigen and their regulatory role in humoral immune response in mice.

The mutant lpr gene causes a generalized massive T cell proliferation and an associated autoimmune disease in mice. The lpr T cells bear unusual membrane phenotypes and play a causative role in the pathogenesis of autoimmune disease through excess production of some lymphokines. Therefore, the "aberrant" T cells in lpr mice may be normal regulatory T cells in non-lpr-bearing mice, if nonproliferative. We thus attempted to produce a xenogeneic monoclonal antibody (ALP-1) directed against the lpr T cells. The ALP-1 monoclonal antibody reacted with the antigen Lp-1 distributing on about one half of the proliferating lymph node cells from MRL/Mp-lpr/lpr mice but not on the cells from non-lpr-bearing mice. Nevertheless, a significant number of Lp-1+ cells appeared in the lymph node and spleen cells from these normal mice after in vitro stimulation with mitogens. Functional studies revealed that either the treatment with ALP-1 plus complement of the antigen-primed splenic T cells from non-lpr-bearing mice or the addition of ALP-1 alone all but completely abolished the development of plaque-forming cells against sheep red blood cells in T-B cell coculture. Pretreatment of spleen cells with ALP-1 plus complement, however, did not affect other in vitro T cell functions such as mitogen-induced proliferative responses, interleukin 2 production, response in mixed lymphocyte culture (MLC) and the MLC-induced cytotoxic T cell activities. Thus, Lp-1+ T cells in normal mice are unique T cells that may play an important regulatory role in humoral immune response.

Animals↗