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Biomedical subjects

Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 811 records · Page 45Linked to original sources
PubMed1994

[A case of primary pulmonary cryptococcosis with increased serum carcinoembryonic antigen].

A case of primary pulmonary cryptococcosis with increased serum carcinoembryonic antigen (CEA) (7.0 ng/ml) is presented. The diagnosis was made by transbronchial lung biopsy (TBLB) and no abnormality was found in either gastrointestinal tract or immunity. Immunohistochemical study of the lung specimen showed that CEA was present on the surfaces of alveoli. The level of CEA fell to 0.8 ng/ml after administration of an antimycotic agent (Fluconazole) with simultaneous improvement of the chest radiographic findings. This case indicates that increased serum CEA depends on pulmonary cryptococcosis. TBLB and administration of antimycotic agents, instead of surgical resection, are useful in the diagnosis and treatment of this disease.

Adult↗
PubMed1994

Brain microvessels: factors altering their patency after the occlusion of a middle cerebral artery (Wistar rat).

The progression from ischemic injury to pannecrosis that occurs in the rat brain several hours after occluding a large artery may be partly attributable to a worsening of the circulation through the microvessels. The objective of this study was to quantitate selected structural changes involving astrocytes and endothelial cells within an area of focal brain ischemia created by the occlusion of a middle cerebral artery. The magnitude of these structural changes was correlated with alterations in the patency to a circulating macromolecule through the microvessels (< or = 15 mu in diameter) located within the territory of the occluded artery. One hundred eighty-five adult male Wistar rats had the right middle cerebral artery occluded after threading a nylon monofilament through the external carotid artery. Experiments were terminated by either cardiovascular perfusion or decapitation and immersion fixation at intervals ranging between 30 minutes and 7 days after the arterial occlusion. Randomly selected animals from each experimental subgroup were injected intravenously with horseradish peroxidase (molecular weight 44 kd) approximately 20 minutes before death. The progressive decline in the area fraction comprised by the vessels filled with horseradish peroxidase was preceded at 30 to 60 minutes by an increase in the surface area occupied (on a cross-section of a microvessel) by endothelial cells (both nucleus and cytoplasm). This was followed by an increase of 23.7% in the mean diameter of astrocytes nuclei and a decrease of approximately 35% in lumenal surface of the microvessels. These observations suggest that the occlusion of a large cerebral artery causes prompt swelling of endothelial cells and astrocytes; both of these early biological responses may interfere with erythrocyte circulation and oxygen delivery, which (after the arterial occlusion) are entirely dependent on the circulation provided by the collateral arterial connections. Through its interference with microvascular patency and oxygen delivery, cell swelling may influence the rate at which neurons become necrotic. In this model of brain infarct the number of necrotic neurons peaks approximately 72 hours after middle cerebral artery occlusion.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

A new method for quantitative estimation of the degree of DNA fragmentation utilizing agarose gel electrophoresis.

We designed a new method for quantitative analysis of the degree of DNA fragmentation, a characteristic feature of apoptosis. A photograph of an agarose gel electrophoresis of fragmented DNA was incorporated by an optical density scanner or equivalent equipment, and the integrations of middle molecular size area (10,000 to 300 bp), single nucleosomal size area (smaller than 300 bp) and total lane area were calculated. We defined fragmentation rate or (%)FR as the amount of fragmented DNA expressed as the percentage of the total amount of DNA, assigning the coefficients of 1 and 0.5, respectively, to the fragments completely digested into single nucleosomal length and to those partially digested (between 10 k to 300 bp). A standard calibration curve was constructed from triplicate experiments of target nuclei digestion by micrococcal nuclease, which revealed that this method covered a wide range of nuclease activity. We also confirmed that our method was applicable to an autodigestion assay of isolated nuclei which represented endogenous endonuclease activities. This method may be a useful tool for quantitative analysis of endonuclease activities capable of producing nucleosomal-size DNA fragmentation.

Apoptosis↗
PubMed1994

[Efficacy of GRF (gelatin-resorcin-formalin) glue on surgery for type A aortic dissection].

The tissue biological adhesive GRF glue has been used in our department to have dissected aortic layers adhered and to reinforce the dissected aortic stumps during surgery for aortic dissection. From May 1992 to August 1993, 12 patients were operated for type A aortic dissection; 4 patients with acute dissection and 8 patients with chronic dissection. There were 5 men and 7 women whose ages ranged from 51 to 69 years with an average of 60.6 years. Replacement of the ascending aorta alone was performed for 6 patients. Replacement of both the ascending aorta and transverse arch was carried out for 4 patients, and replacement of the ascending aorta, transverse arch and the descending aorta was accomplished in 1 patient. Primary repair was performed for 1 patient with intraoperative acute dissection that occurred during surgery for mitral valve. There were no operative or hospital deaths. Preoperative aortic regurgitation was present in 5 patients. Following gluing the aortic root dissection, aortic regurgitation disappeared in all patients confirmed by postoperative aortograms. The use of GRF glue significantly reduced the average amount of intraoperative bleeding from 2893 ml to 1169 ml and also significantly reduced the use of Teflon felt strips for the proximal anastomosis. We believe that use of GRF glue can improve the surgical outcome for acute and chronic aortic dissection.

Aged↗
PubMed1994

Marked apoptosis of human myelomonocytic leukemia cell line P39: significance of cellular differentiation.

Myelodysplastic syndrome (MDS)-derived leukemia cell line P39/Tsugane could be induced to apoptosis by a variety of agents including metabolic inhibitors, a calcium ionophore and differentiation-inducing agents. As evaluated by characteristic morphological changes and oligonucleosomal lengths DNA ladder, the levels of apoptosis in P39 cells induced by actinomycin D, or A23187, were far greater than in other myeloid lines examined in this study. When 22-oxa-1 alpha, 25(OH)2D3 (D3), dimethyl sulfoxide (DMSO) and all-trans retinoic acid (RA) were used as differentiation-inducers, varying degrees of apoptosis were seen. D3 induced monocytoid differentiation, but not apoptosis above the control level. On the other hand, RA induced profound apoptosis concomitant with the progressive expression of differentiation markers. Studies on morphology, functions and phenotypes of P39 cells exposed to differentiation inducers suggest that the incidence of apoptosis was not affected by the process of differentiation, but cells in the process of varying degrees of differentiation may die via apoptosis. Moreover, RA-treated P39 cells are unique in the simultaneous occurrence of profound apoptosis and differentiation. We propose that RA-treated P39 differentiation model is ideally suited for the study of MDS.

Apoptosis↗
PubMed1994

[A case of suprasellar intradural chordoma].

An extraosseous and intradural chordoma of the suprasellar region is described in a 54-year-old male who presented himself with left homonymous hemianopia. Computed tomography showed an isodensity tumor containing a cyst in the suprasellar region. Magnetic resonance images demonstrated the tumor as an isointense mass with heterogeneous enhancement after intravenous administration of a contrast agent, and as a high signal intensity mass on T2-weighted images. The associated cyst was also clearly demonstrated. The tumor was diagnosed preoperatively as a craniopharyngioma and was resected using the frontobasal interhemispheric approach. However, the resected tumor had the typical histological and immunohistochemical characteristics of chordoma. Only ten cases of totally extraosseous and intradural chordoma have been reported. The histogenetic background of this tumor is also discussed in this paper.

Brain Neoplasms↗
PubMed1994

[Difference of cerebral arteriolosclerosis between the deep and subcortical white matter in normal aging and vascular dementia of Binswanger type].

A comparative pathological study of arteriosclerosis was conducted between the deep white matter (M1) and the subcortical white matter (M2) to investigate the difference in the arteriolar changes in normally-aging individuals and those presenting vascular dementia. The arterioles (20-100 microns in outer diameter) of 95 autopsied brains were examined (56 control cases; C group, 24 hypertensive cases; HT group, and 15 Binswanger type vascular dementia cases; VD group). In C group, the primary pathological change was adventitial proliferation (AP), which was significantly more pronounced in M1 than in M2. AP in M1 was found to have advanced promptly with aging, while AP in M2 advanced mildly. AP in M1 was much more pronounced in HT group than in the age-matched C group, but little difference in M2 was observed between the two groups. AP in VD group was more pronounced in M2 than in M1 compared with HT group. These findings indicate that AP in M1 occurs prior to that in M2 in the process of normal aging, and that AP, in M2 as well as in M1, may play an important role in the pathogenesis of Binswanger type vascular dementia.

Adult↗
PubMed1994

[Relation of pulmonary vascular response to pressure-flow relationship during incremental exercise in patients with chronic obstructive pulmonary disease (COPD)].

Twenty-eight COPD patients underwent right heart catheterization while in clinically stable condition. Pulmonary vascular response to oxygen was evaluated by the percent change in pulmonary arteriolar resistance after 100% oxygen inhalation (% delta PAR), and its relation to the pressure-flow relationship during incremental exercise was assessed. Mean pulmonary arterial pressure (PPA) during exercise was plotted against the cardiac index (C.I.) from rest to maximal exercise in each patient. In most of the patients, the changes in PPA were nearly linear to the C.I. Therefore, a slope could be obtained from the regression equation in each patient. Patients were divided into two groups according to whether their % delta PAR was greater than 20 defined as a responder (RES), or less than five defined as a non-responder (N-RES). Seven out of 28 patients were RES, nine were N-RES, RES showed a higher %FEV1.0 level, C.I. and stroke volume index (S.I.) at maximal exercise, and a lower level of RV/TLC as well as slope. The slope correlated significantly with %DLCO (r = -0.724, p < 0.01), baseline PAR (r = 0.562, p < 0.01) and % delta PAR (r = -0.522, p < 0.01). These results suggest that the diminished pulmonary vascular bed, and the distensibility of pulmonary vessels, appear to contribute to the steepness of the slope and reduced % delta PAR in patients with COPD.

Administration, Inhalation↗
PubMed1994

[Percutaneous transluminal angioplasty for stenosis of coronary artery bypass grafts: a comparison of arterial grafts versus vein grafts with regard to restenosis and re-do CABG].

Stenoses of ten arterial grafts and thirty-four venous grafts from previous coronary artery bypass grafting (CABG) were treated with percutaneous transluminal angioplasty. In all ten arterial grafts, stenosis occurred at the distal coronary anastomotic site (A-d). In vein grafts, stenosis occurred at the proximal aortic anastomotic site (V-p) in 10, at the graft body (V-b) in 9 and the distal coronary anastomotic site (V-d) in 10 vessels. The initial success rates of angioplasty were 89% (A-d), 100% (V-p), 89% (V-b) and 100% (V-d). The time period between CABG and angioplasty was significantly shorter for A-d (4 +/- 3.8 months) and V-d (8.1 +/- 9.9 months) groups than for V-p (56.9 +/- 35.7 months) or V-b (45.9 +/- 48.6 months) groups. The restenosis rates following angioplasty were 0% (A-d), 50% (V-p), 50% (V-b) and 0% (V-d). Repeat CABG surgery was required for restenosis in 2 patients of group V-p and V-b. Our experience suggests that angioplasty can be performed with a high success rate for stenosis at the distal anastomosis of either arterial or vein grafts after CABG.

Anastomosis, Surgical↗
PubMed1994

Influx of leukocytes and platelets in an evolving brain infarct (Wistar rat).

The results of several experimental studies of focal ischemia and anecdotal observations suggest that leukocytes may contribute to the injury initiated by an arterial occlusion. The timing and the nature of leukocyte responses in evolving brain infarcts (either human or experimental) are incompletely characterized. This is a study of experimental brain lesions in 96 Wistar rats that underwent occlusion of a large intracranial artery for variable intervals ranging between 30 minutes and 7 days. The experimental model, based on the occlusion of a middle cerebral artery ostium via the insertion of a nylon monofilament through the external carotid artery, does not require opening the skull; therefore, the inflammatory response is not influenced by the effects of craniotomy and changes in intracranial pressure are only those induced by the ischemic lesion. All 96 animals having the same type of arterial occlusion developed an ischemic brain lesion (limited to the territory of the corresponding artery) that evolved into an area of extensive neuronal necrosis over a period of 6 to 12 hours followed by pan-necrosis (infarct) approximately 60 hours later. In this study, leukocytes (in particular polymorphonuclear cells) were detected in the microvessels (capillaries and venules) of the ischemic hemisphere as early as 30 minutes after the arterial occlusion. Numbers of intravascular neutrophils peaked at 12 hours, whereas intraparenchymal granulocytes were most numerous at 24 hours; a few granulocytes were visible in the brain infarct as late as day 7. Circulating monocytes were first detected within the capillaries/venules of the ischemic area after 4 to 6 hours. Platelet aggregates were more abundant in the arterial than the venous side of the circulation, and luminal obstruction of arteries by platelet aggregates became noticeable only 48 hours after the arterial occlusion. Fibrin thrombi were conspicuous for their absence. These observations provide the background for studies that will attempt to unravel the relationship between the biological responses of leukocytes and neuronal necrosis secondary to focal ischemia.

Animals↗
PubMed1994

[An early phase II study of CPT-11 (irinotecan hydrochloride) in patients with hematological malignancies].

An early phase II study of CPT-11 (irinotecan hydrochloride) was conducted in patients with hematological malignancies by 4 administration regimens in a cooperative study involving 13 institutes in Japan. The overall response rate was 23% (7/30) for non-Hodgkin's lymphoma, 33% (1/3) for Hodgkin's disease, 18% (2/11) for acute lymphoblastic leukemia and 7% (1/15) for acute myelogenous leukemia. One PR was also obtained in a patient with chronic myelogenous leukemia. Among responders, 6 relapsed and refractory malignant lymphomas (ML) and 2 relapsed and refractory acute leukemias (AL) were involved. The response rates in ML with the regimens B (40 mg/m2 for 5 days every 3-4 weeks) and C (40 mg/m2 for 3 days every weeks) were 31% (5/16) and 33% (3/9), respectively. The other regimens (regimen A, 200 mg/m2 once a day every 3-4 weeks and regimen D) resulted in no response. Responses in AL were only observed in regimen D (20 mg/m2 twice a day for 7 days every 3-4 weeks). Major toxicities were leukopenia (91%), nausea/vomiting (74%), diarrhea (73%) and anorexia (64%). The incidence of severe gastrointestinal symptoms was higher in regimen B than regimen C. Further studies are warranted to confirm the effectiveness and safety of CPT-11 against ML and AL. The recommended administration schedule was regimen C for ML and regimen D for AL.

Adolescent↗
PubMed1994

[An early phase II study of CPT-11 (irinotecan hydrochloride) in patients with advanced breast cancer].

An early phase II study of irinotecan (CPT-11) in patients with advanced or recurrent breast cancer was undertaken by a cooperative study group of 15 institutes in Japan. CPT-11 was administered by intravenous drip-infusion. The administration schedules were 100 mg/m2 weekly (regimen A), 150 mg/m2 biweekly (regimen B), and 200 mg/m2 every 3-4 weeks (regimen C). There were 4 partial responses (PRs), 12 cases with no changes (1 minor response) and 9 cases of progressive diseases with a response rate of 16% (4/25). One out of 7 patients on regimen A and 3 patients out of 15 patients on regimen C achieved PR with a response rate of 14% and 20%, respectively. In three out of 4 PRs, prior chemotherapy, endocrinotherapy or radiotherapy had failed. Major adverse reactions were leukopenia 28/33 (85%), neutropenia 19/25 (76%), anemia 15/33 (46%), nausea/vomiting 28/33 (85%), anorexia 25/33 (76%), diarrhea 22/33 (67%) and alopecia 20/33 (61%). The incidence of leukopenia and thrombocytopenia seemed to be higher in regimen C than regimen A, and diarrhea was also more severe in regimen C than regimen A. The recovery of leukopenia was delayed in some patients on regimen C. The results suggested that CPT-11 was effective against advanced or recurrent breast cancer. The recommended administration schedule for a late phase II study was thought to be 100 mg/m2 weekly, considering efficacy and safety.

Adult↗
PubMed1994

[Evaluation of colon diseases by using new method of extracorporeal ultrasonic examination during usual colon endoscopy].

Generally two types of ultrasonic colon examination method are carried out. One is extracorporeal ultrasonographic examination (US). And another is endoscopic ultrasonographic examination (EUS). US is technically easy but is difficult to take good image of colon diseases. EUS can give us good and sufficient informations. But it is technically difficult and gives much trouble to patients. During usual endoscopy, we have tried extracorporeal ultrasonic examination by filling de-aired water around the diseased colon area. With this new method, we could easily identify the disease and got much better picture than usual US. And this new method gave almost no trouble and pain to examinees in comparison with EUS.

Calcinosis↗
PubMed1994

[Myelodysplastic syndromes--clinical and biological features].

The myelodysplastic syndromes comprise a heterogeneous group of hematopoietic disorders characterized by peripheral cytopenia, and ineffective and dysplastic hematopoiesis. Patients are predominantly aged, and often develop acute non-lymphocytic leukemia. Bone marrow failure, notably infection and bleeding, is the most common cause of death. Our understanding of the biology of the myelodysplastic syndromes is limited and thus reduces the efficacy and specificity of therapeutic intervention. Available evidence, however, suggests that the myelodysplastic syndromes arise from hematopoietic stem cells. The emergence and progression of the myelodysplastic clone have been reviewed in the light of the multistep theory of human carcinogenesis.

Cell Death↗