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Biomedical subjects

S Kubo

Publications and source records attributed to S Kubo.

At least 415 records · Page 23Linked to original sources

Age-related change in the potential of bone marrow cells to repopulate the thymus and splenic T cells in mice.

Bone marrow chimeras were produced between various combinations of young and old mice using either C57BL/6 mice only or a combination of C57BL/6 and B10.Thy-1.1 mice. The wet weight of the thymus and the number of thymocytes and splenic T cells of donor origin were assessed at appropriate intervals after the bone marrow transplantation. It was revealed that the old bone marrow was inferior to young in terms of the capacity to repopulate the thymus and splenic T cells. Moreover, some age-related qualitative changes appeared to occur in the thymocyte progenitors, as the composition of Lyt phenotype of donor-type T cells in the spleen was different between chimeras produced with young bone marrow and those with old.

Aging↗

Contrasting feature in the repopulation of host-type T cells in the spleens of F1----P and P----F1 radiation bone marrow chimeras.

The regeneration and persistence of host- and donor-derived T cells were examined in the thymus as well as the spleen of mouse radiation bone marrow chimeras of two semiallogeneic combinations (F1----P, P----F1) with different Thy-1 markers on T cells of donor and host origins. An unexpectedly large number of host-type T cells were recovered from the spleens of F1----P chimeras, amounting to as high as 45 and 25% of total T cells at 6 and 14 weeks after bone marrow transplantation (BMT), respectively. To the contrary, the residual host-type T cells in the spleens of P----F1 chimeras disappeared quickly, resulting in less than 0.1% of total T cells at 6 weeks after BMT. It was also revealed that the number of host-type T cells in the spleens of F1----P chimeras decreased in proportion to increase of radiation dose given to the recipients.

Animals↗

Effect of splenectomy on liver regeneration and polyamine metabolism after partial hepatectomy.

The effect of splenectomy on hepatic ornithine decarboxylase (ODC) induction, DNA synthesis, and mitosis of hepatocytes was studied in rat liver after partial hepatectomy. ODC activity markedly increased in the early stages of liver regeneration, and the increase in the activity was significantly enhanced in splenectomized rats. Splenectomy specifically induced ODC since tyrosine aminotransferase and general protein synthesis were not affected. Splenectomy also enhanced increase in hepatic polyamines, DNA synthesis, and mitosis in regenerating liver. The results suggest that splenectomy affects liver regeneration after partial hepatectomy by enhancing induction of ODC activity, which is an important biochemical event in the early stage of liver regeneration.

Animals↗

Binding of Clostridium botulinum neurotoxin to gangliosides.

The binding characteristics of Clostridium botulinum neurotoxins of types B, C1, and F to gangliosides was studied by thin layer chromatography plate and microtiter plate methods at low (10 mM NaCl in 10 mM Tris-HCl buffer, pH 7.2) or high (150 mM NaCl in 10 mM Tris-HCl buffer, pH 7.2) ionic strengths and at 0 or 37 degrees C. The three types of toxins bound exclusively to three kinds of gangliosides, GD1a, GD1b, and GT1b, in both the thin layer chromatography plate and the microtiter plate methods. Type C1 toxin bound to the three gangliosides under all the conditions, while type B and F toxins bound only at low ionic strength and 37 degrees C. At low ionic strength, the binding kinetics for the three toxins was monophasic in Scatchard plots, and the association constants obtained in the microtiter plate system were 2-4 X 10(8) M-1. In contrast, the binding kinetics of type C1 toxin in high ionic strength was biphasic in the Scatchard plot, and two association constants were obtained in the microtiter plate system. The heavy chain facilitated the binding of the toxin to the gangliosides. These results indicate that different types of botulinum toxins bind to the gangliosides under different optimal conditions and that gangliosides may not be the common receptor for all types of botulinum toxins. The gangliosides may bind to type C1 toxin together with other potential receptor(s) on synaptosomal membranes.

Botulinum Toxins↗

Monoclonal antibodies distinguish between the head portions of two myosin isozymes from chicken breast muscle.

Monoclonal antibodies against chicken breast myosin and its subfragment-1(S-1) were produced. One antibody, 2G41, reacted with S-1 containing a light chain 3 (LC3), but not with another S-1 containing a light chain 1 (LC1) or a mixture of the light chains. A structural difference can be assumed to exist between the head portions of the two myosin isozymes. Antigenicity of S-1 toward 2G41 could not be detected after tryptic digestion into three fragments of 50K, 27K, and 20K daltons. Another monoclonal antibody, M68, was obtained from mice immunized with myosin. M68 preferably recognized the heavy chain from S-1 containing LC3 rather than that from that containing LC1 or S-1. M68 reacted with the 27K fragment among the three.

Animals↗

Development of autologous specific reactivity to human neuroblastoma.

Antigenic analysis of neuroblastoma cells was performed by autologous typing and indirect immunofluorescent test combined with absorption tests. Serum of a patient with neuroblastoma before treatment showed weak reactivity with cultured autologous neuroblastoma cells, while serum obtained from the same patient 3 months after chemotherapy exhibited strong reactivity with the same indicator cells. This reactivity was absorbed with neither cultured autologous fibroblasts nor allogeneic tumor cells from seven neuroblastoma and two melanoma patients. In addition, cultured hematopoietic cells from two subjects, normal fetal and adult tissues also failed to remove the reactivity. This reactivity, however, was completely removed by the absorption with the cultured autologous neuroblastoma cells and the homogenate, suggesting that these neuroblastoma cells may express tumor specific antigen(s), located on neither normal cells in any stage of the development nor other malignant cells, although the cells and tissues we tested may not be adequate to confirm this.

Abdominal Neoplasms↗

Cardiovascular effects of a new inotropic agent, denopamine (TA-064); with reference to it's effects on cardiac hemodynamics and metabolism.

A new inotropic agent, denopamine (TA-064) was shown to have a strong positive inotropic effect. Its effect on cardiac hemodynamics and metabolism was evaluated by using wall stress and direct measurement of myocardial oxygen consumption. With plasma concentration of denopamine (21-29 ng/ml on average), attainable by one single oral dose (10 mg), the positive inotropic effect was evident by the significant increase in peak (+)dp/dt (+15% increase from control), and shortening velocity of the left ventricle (+39%), when heart rate or blood pressure was not altered significantly. End diastolic stress and end systolic stress of the left ventricle, defined as indices of preload and afterload, respectively, were reduced significantly. The reduction of preload (-51%) was the result of improved left ventricular filling, and the reduction of afterload (-23%) was due to the increased contractility. Neither coronary sinus blood flow not aortocoronary AV O2 defference was changed. Consequently, myocardial oxygen consumption remained unaltered. When the dose is chosen properly, denopamine is able to exert salutary effects in patients with severe heart failure.

Administration, Oral↗

[Chemotherapy of balloon-occluded arterial infusion in a patient with unresectable hepatocellular carcinoma and autoimmune hemolytic anemia].

The patient, a 76-year-old woman, was found to have a tumor in the epigastrium in April 1983 and was admitted to our hospital. She was diagnosed as having hepatocellular carcinoma in the left lobe of the liver with intrahepatic metastases in the right lobe. The patient also had autoimmune hemolytic anemia. Because of this condition and the metastases, we decided that the tumor was not resectable. Transcatheter arterial embolization was unsuccessful, and therefore, beginning on June 28, 1983, the patient was treated three times using balloon-occluded arterial infusion of 10 mg of mitomycin C and 30 mg of adriamycin into the proper hepatic artery. After these treatments, the serum alpha-fetoprotein level returned to normal levels. CT scans and hepatic angiography showed that the main tumor and the metastases had become smaller. The patient presently shows no evidence of disease, three years after treatment.

Aged↗

A case of intraluminal duodenal diverticulum associated with congenital biliary dilatation: a review of the literature in Japan.

A case of intraluminal duodenal diverticulum (IDD) associated with congenital biliary dilatation is reported. Patients with intraluminal duodenal diverticulum often have congenital anatomical abnormalities or acquired diseases. The treatment of the intraluminal duodenal diverticulum itself is easy, but it is important to detect and treat other disorders also present.

Biliary Tract↗

[A case of pleomorphic xanthoastrocytoma].

A case of pleomorphic xanthoastrocytoma (Kepes) is reported. This patient was a 12-year-old boy with a history of convulsive seizure. Neurological examination on admission showed no abnormality. Plain CT scan revealed a well defined low density area with calcification in the right frontal lobe. A part of peripheral portion of low density area were well enhanced with contrast media. At operation, there was a cyst containing xanthochromic fluid in the right frontal lobe. A part of cyst well near the cerebral surface was reddish hard. Total removal of nodular tumor and subtotal removal of the cyst wall were performed. He has been doing well for these 3 years following craniotomy and has no deficit without CT evidence of recurrent tumor. Histologically the tumor cells displayed marked pleomorohism. However either necrosis or mitosis were not seen. Frequently these cells had vacuolated or foamy cytoplasm. There were many of the giant cells and multinucleated cells. In some area, these tumor cells were surrounded by a fine network of reticulin fibers. Electron microscopically the tumor cells were occasionally filled with glial filament and lipid granules were seen. Immunoperoxidase technique revealed GFAP in the cytoplasm of the tumor cells. This case was considered to be pleomorphic xanthoastrocytoma first proposed by Kepes.

Astrocytoma↗

Phosphorylation of high mobility group 1 protein by phospholipid-sensitive Ca2+-dependent protein kinase from pig testis.

Phospholipid-sensitive Ca2+-dependent protein kinase was partially purified from total particulate fraction of pig testis. The enzyme phosphorylated high mobility group 1 protein (HMG 1), one of the major chromatin-associated non-histone proteins. Other HMG proteins (HMG 2, 14 and 17) were not phosphorylated by the enzyme. Exhaustive phosphorylation of HMG 1 revealed that 1 mol of phosphate was incorporated/mol of HMG 1. The apparent Km value for HMG 1 was 3.66 microM. 1,3-Diolein stimulated the phosphorylation at 10 microM-Ca2+ in the presence of phosphatidylserine. The phosphorylation of HMG 1 was inhibited by adriamycin, an inhibitor of spermatogenesis.

Animals↗