Search PubMed⌕ Search

Biomedical subjects

T Tsukada

Publications and source records attributed to T Tsukada.

At least 163 records · Page 9Linked to original sources
PubMed1991

Immunocytochemical analysis of the atherosclerotic lesion.

We have performed immunocytochemical investigations on the distribution of various cell types and proliferating cells in human atherosclerotic lesions. Studies include fibrocellular tissue response following percutaneous transluminal coronary angioplasty (PTCA) or aortocoronary (A-C) bypass operation using monoclonal antibodies specific to smooth muscle cells, macrophages, endothelial cells, lymphocytes and proliferating cell nuclear antigen (PCNA). All studies were performed on methanol-Carnoy's-fixed, paraffin-embedded tissues. The cellular composition of the following three types of raised lesions were analyzed: 1) fibro-fatty lesions composed almost exclusively of macrophages; 2) fibrous lesions predominantly composed of smooth muscle cells; 3) advanced plaques characterized by complex layers of smooth muscle cells and macrophages with considerable variation from region to region. Also noted were foci of medial and even intimal vascularization subjacent to the more advanced plaques. Cells encountered within the fibrous intimal thickening in the vein graft or fibrocellular tissue response following PTCA were predominantly smooth muscle cells in origin. Some cells were PCNA-positive. These studies demonstrate the application of monoclonal antibody technology to the study of the cellular composition and cell kinetics of human atherosclerotic lesions.

Antibodies, Monoclonal↗
PubMed1991

[A three-dimensional computerized reconstruction of the rectum, anus and surrounding muscles of the rat fetus at the 20th gestation day].

Using fetuses of Wistar/I rats on the 20th gestation day. We designed a three-dimensional computerized reconstruction of the rectum, anus and the surrounding muscles. The tissues were fixed in Bouin's solution sagittally sectioned serially were stained with hematoxylin-eosin. Light microscopic pictures at 40 x magnification were subjected to the analysis using a three-dimensional image processing system, consisting of a drum-scanner, a general purpose computer (Micro VAX II), and a color image processor. The results showed that this system clearly reconstructed the three-dimensional image of the rectum, anus and the surrounding muscles and suggested the presence of the puborectal muscle sling.

Anal Canal↗
PubMed1991

[Experimental and clinical studies of urethral anesthesia on etiology and treatment of detrusor-sphincter dyssynergia].

We studied whether detrusor-sphincter synergia during micturition was obtained by means of urethral anesthesia with lidocaine hydrochloride in five thoracic spinal cats and eight clinical cases with detrusor-sphincter dyssynergia. In thoracic spinal cats with detrusor-sphincter dyssynergia, urethral anesthesia produced detrusor-sphincter synergia, an increase in the maximum bladder pressure and a decrease in the residual volume. In clinical cases with detrusor-sphincter dyssynergia, urethral anesthesia produced detrusor-sphincter synergia or a decrease in the external urethral sphincter activities during micturition, and a decrease in the maximum urethral closure pressure and the residual volume. There were no remarkable changes of the external urethral sphincter activities during urine storage phase before and after urethral anesthesia in both spinal cats and clinical cases. These results suggest that urethral anesthesia blocks the urethro-urethral contraction reflex and secondarily activates vesico-urethral relaxation reflex. The block of urethral sensory nerves is thought to effectively treat detrusor-sphincter dyssynergia.

Anesthesia, Local↗
PubMed1991

[Transurethral intracavitary irradiation for carcinoma of the prostate].

This paper describes a new technique and preliminary clinical results of remote after-loading transurethral irradiation for cancer of the prostate. As of January 1986, twelve patients with adenocarcinoma of the prostate have been treated by our radiotherapy technique. Clinically, 3 patients were in stage B2, 3 in stage C, 3 in stage D1 and 3 in stage D2. These patients have been followed up for 13 to 33 months with a median follow-up period of 20.6 months. The dose of transurethral irradiation was 9-10 Gy. to the prostatic capsule and about 2 Gy. to the rectum in one procedure. We repeated this radiotherapy 3 to 4 times within an about 1-month period. Three patients in stage D1 and one patient in stage C received an additional external beam radiation (40 Gy.) to the entire pelvis. A needle biopsy was also performed every 4-6 months after irradiation. Local tumor response proved rapid and satisfactory as verified by a rectal examination and ultrasonography. The biopsies revealed a 70% negative rate within one year. The most common side effect was transient frequency observed in 7 patients. Severe complications such as incontinence, urethral stricture, or proctitis were not evident. This study suggests that intracavitary irradiation of cancer of the prostate is effective and safe. This method may have wider application.

Adenocarcinoma↗
PubMed1991

[Identification of effective region of the pons in response to inaperisone which facilitates urine storage].

To identify the effective region of the pons in response to inaperisone which facilitates urine storage, inaperisone (100 mM, 0.2 microliters) was injected into the nucleus locus coeruleus alpha (LCa, the pontine micturition center), the nucleus locus subcoeruleus (LSC, the pontine urine storage center) and the nucleus reticularis pontis oralis (PoO, micturition inhibitory region) of the decerebrate cats. On reflex micturition, inaperisone injection into the LSC decreased voiding volume, and increased residual volume and bladder capacity, significantly. However, there was no difference in the maximum bladder pressure before and after inaperisone injection into the LSC. Inaperisone injection into the LCa or the PoO had no influence on reflex micturition. These results suggest that effective region of the pons in response to inaperisone is the LSC, and that inaperisone facilitates the urine storage neural mechanism in the LSC.

Animals↗
PubMed1991

[Non-invasive imaging diagnosis of left renal vein compression causing hematuria. Part 2. CT].

Left renal veins of 77 patients were examined by computed tomography (CT) to evaluate its usefulness in determining the left renal vein compression which is causing renal bleeding. From CT image, left renal vein compression was observed in 6 (86%) of the 7 cases which had been classified as idiopathic renal bleeding, in 9 (21%) of the 42 cases which had urinary tract diseases causing hematuria, and in 3 (11%) of the 28 cases which did not have hematuria. In 15 of the 18 cases of left renal vein compression, left renal vein was compressed between the superior mesenteric artery and the abdominal aorta, showing so-called nutcracker phenomenon. In the remaining 3 cases, however, the superior mesenteric artery provided sharp delineation from the abdominal aorta. The superior mesenteric artery and the abdominal aorta made the mean angle of 35.5 degree in patients with normal left renal vein, the mean angle of 45.4 degrees in those with left renal vein compression without nutcracker phenomenon, and the mean angle of 11.9 degrees in those with nutcracker phenomenon. CT was superior to ultrasonography, in revealing left renal vein compression.

Adult↗
PubMed1991

The early phenomena of restenosis following percutaneous transluminal coronary angioplasty.

In man the early onset of fibrocellular tissue reaction, which leads to restenosis following an initial successful percutaneous transluminal coronary angioplasty, has been poorly documented because of limited opportunities to study this phenomenon. The present study focused on early changes in seven patients who died within 20 days of a percutaneous transluminal coronary angioplasty procedure. Differences in the mode of laceration were noted between concentric and eccentric plaques. In the former, tears occur at the thinnest site of the plaque or within an already attenuated fibrous cap. The injury usually remains limited to the plaque. In eccentric lesions lacerations tend to occur in the non-atherosclerotic wall segment, affecting the musculoelastic layers and the media. A further site of predilection is the border zone between the non-affected wall and the plaque. Early tissue response is characterized by fibrin-platelet depositions, and a proliferation of macrophages and spindle-shaped cells. The latter express the immunocytochemical characteristics of smooth muscle cells. However, differences occur according to the type of tissue injured. Laceration of the musculoelastic layers or media causes a rapid and extensive cellular response. Injury to an atheroma, on the other hand, mainly causes plaque fissures with either mural thrombosis and total luminal obstruction, extensive plaque haemorrhage or a 'wash-out' of the atheromatous debris. In the latter case the lining of the 'crater' shows an accumulation of macrophages and, once more, a proliferation of spindle-shaped cells. The present observations support the concept that the early response is due to an interaction of platelet-fibrin thrombus and smooth muscle cells, with a possible role for macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Aggressive natural killer cell lymphoproliferative disease of large granular lymphocytes with leukemia-like clinical course in the terminalstage].

A 20-year-old man was admitted to our clinic with fever elevation up to 39 degrees C for two months, generalized lymphadenopathy and hepatosplenomegaly. Histological examination of right scalene lymph node with HE staining showed T cell lymphoma-like finding. The patient was given vindesine and prednisolone, and there was almost no clinical improvement. Abnormal large granular lymphocyte appeared in peripheral blood and increased up to 17,000/microliters in the terminal stage of clinical course. These lymphocytes had abundant pale cytoplasm with rich large azurophilic granules and a large nucleus with a few nucleoli. The phenotype of these cells were as follows: Fc gamma R+, CD2+, CD5-, CD7-, CD3-, CD4-, CD1-, CD8-, sIg-, CD20-, CD11-, CD13-, OKIa+, CD25-, CD16+, Leu7-. These cells did not have the activity of antibody dependent cellular cytotoxicity but had natural killer activity. The gene of T cell receptor (beta and gamma chain) did not rearranged in these cells. We concluded that the abnormal cells were derived from natural killer cells, which caused aggressive clinical course.

Adult↗
PubMed1991

[Prediction of bone marrow function by the appearance rate of RNA-rich reticulocytes during the chemotherapy for hematologic malignancy].

Percentage of RNA-rich (High fluorescence Ratio, HFR), RNA-middle (Middle Fluorescence Ratio, MFR) and RNA-low (Low Fluorescence Ratio, LFR) reticulocytes was estimated by Sysmex R-1000 reticulocyte counter during the chemotherapy of 27 cases with acute leukemia and malignant lymphoma (36 courses). In the beginning of marrow suppression, HFR and/or MFR were decreased faster than LFR, neutrophils or platelets in 14 courses (38.9%). Simultaneous decrease of HFR, MFR and other blood cells were observed in 57.2%. In the recovery phase of bone marrow, faster increase of HFR and/or MFR was noted in 52.8% and simultaneous increase of these reticulocytes with other blood cells was observed in 9 courses (25%). Appearance rate of RNA-rich younger reticulocytes is a sensitive parameter for the prediction of bone marrow suppression and recovery during the chemotherapy for hematologic malignancy.

Adolescent↗
PubMed1991

[Syncytial variant of nodular sclerosing Hodgkin's disease expressing T-cell antigens].

A case of syncytial variant of nodular sclerosing Hodgkin's disease in a 34-year-old woman is reported. Histologically, numerous Reed-Sternberg (RS) cells and their variants were seen in sheets. They were positive for CD30, CD15, CD25, and HLA-DR antigens. In addition, they expressed CD45 antigen and T-cell antigens (CD2, CD4). Molecular genetic analysis showed that this case had a germ line configuration for T-cell receptor (TCR) beta chain, TCR gamma chain, and immunoglobulin heavy chain genes. The percentage of the neoplastic cells in the specimen identified by CD30 positive cells was about 20% which was far above sensitivity of the molecular genetic analysis. Such analysis is reliable as to judgement of the results. Thus, these findings suggest that the RS cells and their variants in the present case are not derived from mature T cell in spite of their T-cell antigens expression.

Adult↗
PubMed1990

Cooperativity between platelet-activating factor and collagen in aggregation of bovine platelets III.

In cooperative aggregation of bovine platelets induced by simultaneous addition of PAF and collagen at subthreshold concentrations the following observations were made. (i) Formation of phosphatidic acid and arachidonic acid metabolites, which characterize PAF and collagen alone-induced aggregation, respectively, was observed very obviously. (ii) A thromboxane antagonist did not completely block the cooperative aggregation. The extent of residual aggregation activity was dependent on concentration of collagen used in the simultaneous administration with PAF. These results suggest that both signal transduction pathways activated by PAF and collagen alone at high concentrations are attained by simultaneous addition of both agonists at subthreshold concentrations through unknown mechanisms.

Animals↗
PubMed1990

Cooperativity between platelet-activating factor and collagen in aggregation of bovine platelets, II.

When subthreshold amounts of platelet-activating factor (PAF) and collagen were added simultaneously, strong aggregation of platelets was induced. However, each agonist alone at these concentrations could not induce aggregation at all (S. Kojima et al, (1987) Biochem. Biophys. Res. Commun. 145, 915-920). This cooperativity was observed not only in aggregation but also in changes of intracellular Ca2+ concentration, 47 kDa protein phosphorylation, and formation of thromboxane. These findings suggest that various steps of signal transduction pathways are enhanced during their cooperativity.

Animals↗
PubMed1990

Effects of repetitive administration of corticotropin-releasing hormone combined with lysine vasopressin on plasma adrenocorticotropin and cortisol levels in secondary adrenocortical insufficiency.

To examine the functioning of the hypothalamo-pituitary-adrenocortical axis in secondary adrenocortical insufficiency, we administered 100 micrograms synthetic human CRH, iv, plus 10 U lysine-8-vasopressin (LVP), im, three times daily for 3 consecutive days. The changes in plasma ACTH and cortisol levels during the administration and the response to an insulin tolerance test (ITT) conducted before and after the administration were determined. In three patients with isolated ACTH deficiency, basal plasma ACTH and cortisol levels were undetectablly low, and there was no response noted in the ITT or during CRH-LVP administration throughout the observation period. In four patients with adrenocortical insufficiency who had undergone successful transsphenoidal microadenomectomy for Cushing's disease and in six patients who had undergone curative unilateral adrenalectomy for Cushing's syndrome, basal plasma ACTH levels were low, but responded considerably to both stimulation tests. Along with the 3 days of CRH-LVP stimulation, however, neither the peak nor the time-integrated ACTH response was significantly enhanced, because of the variability of the responses among the patients. Compared with the ACTH response on the last day of CRH-LVP stimulation, the subsequent ITT tended to induce a lower ACTH response in the post-Cushing's disease patients and a higher response in the post-Cushing's syndrome patients. Regarding the plasma cortisol levels, the basal, peak, and integrated responses tended to increase daily during CRH-LVP administration. Conversely, the ITT after repetitive CRH-LVP administration induced a higher cortisol response than the test before CRH-LVP administration in the post-Cushing's disease patients. No serious complications were noted in any of the patients during or after the treatment. The present findings indicate that 1) repetitive administration of CRH in combination with LVP is a safe and valuable provocation test to examine the pituitary ACTH reserve and the integrity of the pituitary-adrenocortical axis; 2) isolated ACTH deficiency is usually due to a defect at the pituitary level; 3) with respect to adrenocortical responsiveness, post-Cushing's disease patients show a better accumulation of the provocative effect than do post-Cushing's syndrome patients; and 4) both hypothalamic and pituitary dysfunction are responsible for adrenal hypofunction in patients after hypercortisolemia, but post-Cushing's syndrome patients (especially those with a short period of hypercortisolemia) appeared to have less impairment of hypothalamic ACTH-releasing activity than post-Cushing's disease patients.

Adrenal Cortex↗
PubMed1990

Experimental studies on vein graft atherosclerosis (I). Histochemical studies using monoclonal antibodies for smooth muscle cells and macrophages.

Vein graft atherosclerosis characterized by smooth muscle cell proliferation has become the most serious cause of late graft failure. This study was designed to elucidate why marked histological differences occur in atherosclerotic changes between the vein graft and the artery. Fourteen rabbits underwent autonomous transplantation of femoral vein sections (10-12 mm in length) into femoral arteries on the same side. They were then kept on either commercial or 1% cholesterol diet. At 4, 8, 15 and 30 weeks after the operation, they were sacrificed and histochemical & immunocytochemical studies on atherosclerotic changes found in graft and arteries were carried out, using monoclonal antibodies for macrophages (RAM 11) and smooth muscle cells (HHF 35). Atherosclerotic lesions found in arteries of rabbits fed by cholesterol for more than 8 weeks were characterized with the accumulation of macrophage-derived foamy cells with fibrous caps. In contrast, the lesions found in the grafts of the same rabbits were occupied with proliferating smooth muscle cells and very few macrophages. Furthermore, in lesions of the vein grafts of rabbits fed cholesterol for 4 weeks, macrophages were rather frequently encountered in the bottom of the lesions and/or its medial layer, scattering and sometimes forming mass-lesions. These results may suggest structural differences in the vein with its thin and sparse internal elastic lamina and with its thin medial layer, allowing macrophages to pass easily through the elastic lamina and scatter into the media. This may be the reason why autonomous vein graft atherosclerosis is mainly composed of proliferated smooth muscle cells.

Animals↗
PubMed1990

Expression of the human pro-opiomelanocortin gene introduced into a rat glial cell line.

A fragment of human genomic DNA containing the entire pro-opiomelanocortin (POMC) gene was introduced by transfection into the rat glial cell line C6. Blot analysis using poly(A)-rich RNA from the transformed C6 cells showed several hybridization bands. One band was similar in size (1.2 kb) to the POMC mRNA of human pituitary, while two were larger (2.6 and 2.2 kb) and the fourth smaller (800 bp). S1 nuclease mapping revealed that the POMC transcripts in transformed C6 cells were similar to those in non-pituitary tissues. Immunoreactive ACTH (ir-ACTH) was measurable in both the culture medium and cells. Gel chromatography showed that ir-ACTH in the medium eluted at a position identical to that of so-called big ACTH (approximately 40 kDa) which is found in the plasma of patients with ectopic ACTH syndrome. The human POMC gene could thus be expressed in the non-pituitary rat glial cell line C6, although the transcripts and translation products in C6 cells differ from those in the human pituitary. These results suggest that the transformed C6 cell may be a useful tool for studying the regulation of human POMC gene expression in non-pituitary cells.

Adrenocorticotropic Hormone↗
PubMed1990

[Clinical evaluation of imipenem/cilastatin sodium against severe infections in patients with hematopoietic disorders].

Sixty-eight patients with severe infections associated with hematopoietic disorders were treated with imipenem/cilastatin sodium (IPM/CS) and the efficacy and safety of this drug were evaluated. 1. Fifty-nine patients were evaluable for the efficacy. Clinical efficacies were excellent in 10 patients, good in 24, fair in 11 and poor in 14, and the overall efficacy rate was 57.6%. 2. The clinical efficacy rates were 62% against septicemia and suspected septicemia, 40% against pneumonia and 100% against urinary tract infection (1 case). 3. The clinical efficacy rates when these patients were grouped according to numbers of neutrophils after treatment were: less than 100/mm3; 44.4%, 101-500/mm3; 58.3% and over 501/mm3; 60.5%. The efficacy rate was particularly excellent, 60.0%, for patients with neutrophil counts were less than 100/mm3 both before and after treatment. 4. Sixty-eight patients were evaluable for the safety. Side effects were observed in 5 patients and abnormal laboratory test values were observed in 5 patients.

Adolescent↗