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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

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↗
PubMed1979

Triamterene-induced immune haemolytic anaemia with acute intravascular haemolysis and acute renal failure.

Acute intravascular haemolysis and renal failure developed while a patient was taking triamterene. A direct antiglobulin test with a polyvalent reagent was positive. Serum caused agglutination of normal red cells in the presence of triamterene and caused an increase of partial haemolysis of both trypsin-treated erythrocytes and red cells from a patient with paroxysmal nocturnal haemoglobinuria (PNH) in the presence of complement. From the results of antibody-neutralization test and treatment with 2-mercaptoethanol, the presence of IgM antibody with lambda light chain could be demonstrated. The triamterene seemed to bind strongly to the red cells in vitro but in vivo there was no detectable adsorption to red cells. Haptenic inhibition was not demonstrated. From these results, it was assumed that this antibody was found to cross-react with methotrexate which has a structure similar to that of triamterene.

Acute Kidney Injury↗
PubMed1979

Effects of 2-nicotinamidoethyl nitrate on the cardiovascular system.

Using the dog as experimental animal, effects on the cardiovascular system of a new vasodilator, 2-nicotinamidoethyl nitrate (SG-75), were studied. In the heart-lung preparation, the compound produced a dose-dependent increase in the coronary blood flow, which was associated with only a minimal increase in the myocardial oxygen consumption. There was essentially no change in the myocardial function. The myocardial redox potential was shifted to more positive values. In the isolated perfused heart preparation (Langendorff's preparation), SG-75 produced a dilatation of only the small resistive arterioles. However, it produced a dilatation of the large conductive artery in underperfused myocardium. SG-75 produced a significant increase in the cerebral venous outflow, associated with an increase in the cerebro-spinal fluid pressure. It produced a reducation of the venous return, which was especially prominent in the lower half of the body. In the isolated smooth muscle preparation of the coronary artery, high-doses of SG-75 induced calcium antagonistic effects and produced a relaxation of the lanthanum contracture.

Animals↗