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Biomedical subjects

T Tsukada

Publications and source records attributed to T Tsukada.

At least 19 recordsLinked to original sources
PubMed1992

Activation of phospholipases in platelets by polyclonal antibodies against a surface membrane protein.

In a previous paper we demonstrated using immunochemical techniques that propolypeptide of von Willebrand factor was present on the surface of resting platelets. In the present paper we show that polyclonal antibodies against propolypeptide of von Willebrand factor induce activation of phospholipase(s) in platelets and lead to platelet aggregation. The antibody-stimulation of platelets induced the synthesis of thromboxane A2 (TXA2). Furthermore, the aggregation was inhibited by aspirin and an antagonist of TXA2. Aspirin inhibited not only the aggregation but also the activation of arachidonic acid liberation from phospholipids, but the effect of aspirin on arachidonic acid liberation was cancelled by the combined effect of the antibodies and a TXA2 mimetic agonist, which itself did not activate arachidonic acid liberation. The antibody-induced activation of arachidonic acid liberation and the aggregation were blocked by cytochalasin B. All these results obtained with antibodies were quite similar to the results obtained with collagen.

Antibodies↗
PubMed1992

Immunoreactive corticotropin-releasing hormone levels in the hypothalamus of female Wistar fatty rats.

We have studied immunoreactive corticotropin-releasing hormone (CRH) levels in the hypothalamus of female Wistar fatty rats, a strain with the fa gene transferred from the Zucker rat to the Wistar Kyoto rat, in an attempt to understand the role of CRH in the development of obesity. A study was conducted with 5-week- and 12-week-old female Wistar fatty rats and lean littermates. There was no significant difference in hypothalamic CRH levels between lean and obese rats at the age of 5 weeks (1887 +/- 99.6 vs. 1767 +/- 124 pg/tissue; mean +/- S.E.M.). Hypothalamic CRH immunoreactivities, however, were significantly lower in 12-week-old obese rats (2361 +/- 132 pg/tissue) than those in lean littermates (2992 +/- 118 pg/tissue; P less than 0.05). The difference of CRH contents between the lean and obese group becomes apparent as they grow up and develop obesity.

Aging↗
PubMed1992

Expression of M-CSF receptor encoded by c-fms on smooth muscle cells derived from arteriosclerotic lesion.

Vascular smooth muscle cells in atherosclerotic lesions are phenotypically different from those in the normal arterial wall, and no expression of macrophage colony stimulating factor (M-CSF) receptor encoded by the proto-oncogene c-fms has been demonstrated in normal smooth muscle cells. In the present study, we demonstrated expression of c-fms and high affinity binding of M-CSF in smooth muscle cells isolated from an experimental rabbit model of arteriosclerosis (intimal smooth muscle cells), while no expression of c-fms was shown in medial smooth muscle cells. In the immunocytochemical analysis, both types of smooth muscle cells similarly reacted with an antibody specific to muscle cells (HHF 35) but did not react with an antibody specific to rabbit macrophages (RAM 11). In intimal smooth muscle cells, when cells were incubated with acetylated low density lipoproteins (LDL), the binding of acetylated LDL and foam cell formation were observed. In response to M-CSF, tyrosine-phosphorylation, as analyzed by the detection of anti-phosphotyrosine-reactive proteins, and an increased rate of cell proliferation were observed in intimal smooth muscle cells. These results indicated that intimal smooth muscle cells have the characteristics of monocyte-macrophages such as the expression of c-fms, which may be related to their proliferation and phenotypic conversion into foam cells in atheromatous lesions.

Animals↗
PubMed1992

Molecular characterization of genetic mutations in human lactate dehydrogenase (LDH) B (H) variant.

We have previously detected a single base substitution of G by A at the Arg codon CGC in exon 4 of the mutant lactate dehydrogenase (LDH) gene, an unstable LDH-B variant (case 1). Here, we use the polymerase chain reaction (PCR) to amplify genomic DNA of two cases (the original case 1 and a new patient, case 2). We were able to confirm that case 1 is homozygous for the mutation, causing a replacement of the conserved Arg by His at residue 173. The resulting LDH-B variant subunit is unstable in vivo. Whereas the mutation in exon 4 was not observed in case 2, a different single base substitution of A by C was detected at the Ser codon AGT in exon 3. This mutation causes a replacement of the conserved Ser by Arg at residue 131. Genomic analysis of the family of case 2 by mismatched PCR showed that the missense mutation was consistent with their biochemical phenotypes. The replacement results in a conformational change of the residues near the Ser, probably because the side chain of Arg is much more bulky than that of Ser. The change may affect the arrangement of the cofactor binding site and result in the loss of enzyme activity. The experimental observations are consistent with computer graphics analyses.

Amino Acid Sequence↗
PubMed1992

The influence of argon laser panretinal photocoagulation on the rabbit ERG c-wave.

We observed the influence of panretinal photocoagulation on the ERG c-wave in rabbit eyes. DC-registered ERGs were recorded from rabbit eyes before and after photocoagulation, and compared with those of the fellow eyes. The rabbits were subdivided into 3 groups according to application numbers: 500, 1000, and 1500 spots. The ERG c-waves were found to have totally disappeared in all rabbits 3 days after panretinal photocoagulation, then reappeared with various intervals. In the 500 spot group, the c-wave reappeared after one week, and almost reached control levels in one and a half months. In the 1000 spot group, a 10 day delay was noted, and 90% of control levels were regained after 6 months. In the 1500 spot group, the c-wave didn't reappear until 2 weeks later, and regained 70% (of the control level) after 6 months. The recovery rates were related to the number of laser applications. These results indicate that the ultimate degree of recovery in c-wave amplitude and the time required for the reestablishment of retinal pigment epithelium function both depend on the size of the coagulated area.

Animals↗
PubMed1992

Apolipoprotein E prevents the progression of atherosclerosis in Watanabe heritable hyperlipidemic rabbits.

Apo E plays an important role in plasma lipoprotein metabolism through its high affinity binding to cell surface LDL receptor. In the present study, we studied the effects of apo E on the atherogenic process in Watanabe heritable hyperlipidemic rabbits which are deficient in LDL receptor and an animal model for familial hypercholesterolemia. We isolated apo E from plasma of 1% cholesterol-fed rabbits and administered 10 mg of purified apo E intravenously into five Watanabe heritable hyperlipidemic rabbits three times a week from their age of 2.5 months to 11 months for 8.5 months. After sustained administration to apo E, we found a significant reduction in the accumulation of cholesterol ester in aortae (1.55 +/- 0.07 mg/g tissue) as compared to control rabbits (4.32 +/- 0.61 mg/g tissue). Supporting this, the percentage of the surface area of the aorta with macroscopic plaque was remarkably decreased in apo E-treated animals (18.8 +/- 5.1% vs. 38.8 +/- 8.0% in control). Thus, apo E definitely prevented the progression of atherosclerosis in Watanabe heritable hyperlipidemic rabbits.

Animals↗
PubMed1992

Primary epidural non-Hodgkin's lymphoma in clinical stage IEA presenting with paraplegia and showing complete recovery after combination therapy.

A 70-year-old man was admitted to our hospital because of paraplegia. A spinal epidural tumor (Th VII-XI) was diagnosed by magnetic resonance imaging and resected. Histological examination of the tumor showed non-Hodgkin's lymphoma of the diffuse large cell type (Lymphoma Study Group classification), with a B cell phenotype. The clinical stage was IEA by the Ann Arbor classification. Radiation therapy of the involved field was performed (total dose: 40 Gy), followed by six courses of modified cyclophosphamide, adriamycine, vincristine, prednisolone (CHOP) therapy. He was discharged walking unaided 10 months later and has shown no evidence of relapse in the 26 months since discharge.

Aged↗
PubMed1992

Multiple space-occupying lesions of the spleen in a case of Gaucher's disease.

A 50-year-old female patient was admitted because of an enormously enlarged spleen and thrombocytopenia. Ultrasonography and magnetic resonance imaging revealed multiple space-occupying lesions in the spleen. She was diagnosed as having Gaucher's disease based on the low level of beta-glucosidase activity in leukocytes and Gaucher's cells present in bone marrow aspirate. Severe hypersplenism necessitated splenectomy. Pathological studies of the excised spleen, including ultrastructural examinations, demonstrated that multiple space-occupying lesions in the spleen were composed of typical Gaucher cells.

Female↗
PubMed1992

Primary esophageal non-Hodgkin's lymphoma.

A 77-year-old woman with primary esophageal non-Hodgkin's lymphoma in clinical stage IEA (Ann Arbor Classification) developed pain and difficulty in swallowing. An upper gastrointestinal examination revealed a submucosal tumor from the upper to the middle portion of the esophagus. Histopathological examination at endoscopic biopsy with endoscopic partial incision showed non-Hodgkin's lymphoma (diffuse type--large cell). Immunohistological examination of tumor cells disclosed LCA (+), CD3(DAKO) (+), MT1 (+), UCHL1 (+), MB1 (+), MxPanB (-) and EMA (-) reactivity and showed T cell lymphoma. The clinical stage was determined to be IEA after further work-up. Improvement of swallowing difficulty and esophageal findings on upper gastrointestinal series were noted after modified CHOP therapy and radiotherapy (total 50 Gy).

Aged↗
PubMed1992

Late-onset homozygous protein C deficiency manifesting cerebral infarction as the first symptom at age 27.

We report a 31-year-old female who had repeated thrombosis and was diagnosed as having congenital homozygous protein C deficiency based on decreased protein C antigen and activity, and the findings of family history. This patient had shown no symptom of thrombosis until the age of 27 years, when she had cerebral infarction as the first symptom. Low molecular weight heparin was useful for disseminated intravascular coagulation (DIC) that complicated protein C deficiency in this patient.

Adult↗
PubMed1992

[Vesical ultrasonography and internal examination of female patients with urethral syndrome].

Transabdominal ultrasonography of the bladder and internal examination were performed in 80 female patients without pyuria. They were divided into 3 groups: urethral syndrome with trigonitis (49 cases), asymptomatic trigonitis (16 cases) and normal bladder (15 cases) by cystoscopy. Ultrasonography of trigonitis with or without symptoms showed focal dilation of the submucosal low echo zone and mucosal irregularity around the bladder neck. On the sagittal view, the thicknesses from the surface of mucosa to that of muscle layer within 2 cm from the bladder neck were 4 +/- 1 mm (mean +/- standard deviation) in the group with urethral syndrome and in that with asymptomatic trigonitis, and 3 +/- 1 mm in the normal bladder group. Mucosa of the trigonitis with or without symptom is patients with significantly thicker than that of those with normal bladder (p less than 0.01). On internal examination, tenderness at the upper frontal wall of the vagina was present in 10 of 11 cases (91%) with urethral syndrome, in 2 of 8 cases (25%) with asymptomatic trigonitis and in one of 9 cases (11%) with normal bladder. There was a significant difference (p less than 0.005) between the degree of inflammation and the number of cases with tenderness at the frontal wall of the vagina. From these results, transabdominal ultrasonographic measurement of mucosal thickness around the bladder neck and internal examination for tenderness at the frontal wall of vagina are thought to be useful methods for diagnosis and follow-up of urethral syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[An approach to stoma-less continent urinary diversion by uretero-ileoceco-proctostomy (ileocecorectal bladder)].

The current practice of continent urinary diversion still places the patients under the restraint of the stoma and intermittent catheterization. To overcome these problems, we developed a new technique of urinary diversion of which continent is controlled by the anal sphincter. The isolated ileocecal segment is intussuscepted and interposed between the ureters and the rectum. The conjoined ureters are anastomosed to the stump of the ileal limb, and the antimesenteric portion of the cecal limb is joined to the anterior wall of the rectum. The surgical procedure is simpler than that of the continent reservoirs currently employed. The intussuscepted ileocecal segment prevents fecal reflux to the upper urinary tract and may also inhibit carcinogenesis at the uretero-intestinal junction. Additionally, the rectal capacity is augmented by the side to side anastomosis between the cecal limb and the rectum. Our preliminary experience in 10 cases were satisfactory with respect to voiding function, antireflux mechanism of the intussuscepted ileocecal segment and quality of life. The results will justify further trials with this stomaless continent urinary diversion for those in whom the urethra cannot be used.

Anal Canal↗
PubMed1992

[Respiratory control in diffuse interstitial lung disease].

Whether the change of lung volume affect ventilatory responsiveness to chemical stimuli has not been studied in patients with interstitial lung disease (ILD). We measured the responses of minute ventilation (VE), tidal volume (VT), and occlusion pressure (P0.1) to hypercapnia (HCVR) and hypoxia (HVR) in these patients. Breathing efficiency (delta VE/delta P0.1) and effective compliance (delta VT/delta P0.1) were also measured under the same stimuli. 1) HCVR and HVR were measured in one female patient with hypersensitivity pneumonitis. VE responses during low VC phase (VC; 71% of predicted value) were similar to that during increased VC phase (VC; normal level) in both HCVR and HVR. However, VT responses of low VC phase were lower than those of increased phase, and P0.1 responses of low VC phase were higher than those of increased VC phase. Both breathing efficiency and effective compliance of low VC phase were lower than those of increased VC phase. 2) Thirty one patients with ILD were divided into two groups: low VC group; VC < 80% of predicted value, and normal VC group; VC > 80% of predicted value. HCVR and HVR were compared between two groups. Mean values of VE response to hypercapnia and hypoxia in low VC group were lower than those of in normal group, although they were not significantly different. VT response to hypercapnia and hypoxia were significantly lower of low VC group than those of normal VC group. Mean values of P0.1 responses to hypercapnia and hypoxia of low VC group were higher than those of normal VC group, although they were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Plasma interleukin-6 in patients with disseminated intravascular coagulation].

Plasma Interleukin-6 (IL-6) level was measured in 60 patients with disseminated intravascular coagulation (DIC). Plasma IL-6 level was high in patients with DIC, and was particularly high in patients with multiple organ failure (MOF) or poor prognosis. Plasma IL-6 level correlated positively with C-reactive protein in patients without DIC, but not in those with DIC. The increased plasma IL-6 level observed in DIC patients suggests that activation of the immune system is involved in the progression of DIC and in the pathology of organ failure.

Adult↗
PubMed1992

[Induction therapy of acute promyelocytic leukemia with all-trans retinoic acid: a case, followed by conventional post-remission chemotherapy in complete remission].

A 41-year-old man with untreated acute promyelocytic leukemia (APL) was treated with all-trans retinoic acid (ATRA) 80mg/body/day per os. Complete remission was reached in 16 day without bone marrow hypoplasia and aggravated disseminated intravascular coagulation. The chromosomal abnormality, t (15;17), which presented before therapy has not been found since the 29th day of therapy. During the course of induction therapy with ATRA, there was no complication worth of mentioning. Induction therapy with ATRA is thought to be more effective and safer than conventional chemotherapy to attain complete remission in APL. The complete remission has been maintained for 11 months with conventional postremission chemotherapy.

Adult↗
PubMed1991

Cytokinetic study of aortocoronary bypass vein grafts in place for less than six months.

To evaluate the initial mechanism involving atherosclerotic changes of the saphenous vein graft implanted for coronary artery revascularization in the early stage, immunocytochemical analysis was performed to determine the cell components and kinetics of saphenous vein grafts. Specimens of saphenous vein grafts were obtained from 7 necropsy patients who died at 4 days to 6 months after surgery. Monoclonal antibodies specific for smooth muscle cells (HHF35) and macrophages (HAM56) were used for analysis of the cell components. Migration of macrophages into the intima and the media was observed on the fourth postoperative day. Intimal thickening was characterized by the proliferation of smooth muscle cells, and scattered macrophages were present in the subendothelial layer 1 month after surgery. At 2 months, intimal thickening became prominent and macrophages were recognized circumferentially throughout the layer. At 5 to 6 months, some of the saphenous vein grafts were almost occluded by severe intimal thickening due to proliferation of the smooth muscle cells. Macrophages were also observed both inside and outside of the internal elastic lamina; these are rarely found in the artery. These results suggest that compared with the arterial graft, cytokinesia of the saphenous vein graft contributes to the development of early graft failure because of its rapidity in progression and severity.

Antibodies, Monoclonal↗
PubMed1991

Immunological detection of propolypeptide of von Willebrand factor on platelet surface.

Recently we have found that propolypeptide of von Willebrand factor (pp-vWF) obtained from platelets binds to type I collagen. It is known that pp-vWF is present in platelet alpha-granules and is secreted upon activation. In this paper, we demonstrate the two following evidences to show that it is also present on the surface of resting platelets. [1] The antibody against pp-vWF bound to the surface of platelets. [2] The antibody induced aggregation of platelets. The binding of the antibody and the antibody-induced aggregation of platelets were inhibited in a dose-dependent manner by Fab fragment of the antibody. Platelets from von Willebrand disease patients bound less of the antibody and responded weakly to the antibody.

Antibodies↗