Biomedical subjects

S Maruo

Publications and source records attributed to S Maruo.

54 records · Page 3Linked to original sources

PubMed1990

[Population pharmacokinetic analysis of indocyanine green retention rate at 15 minutes].

Using the population pharmacokinetic (Bayesian) method, we investigated the indocyanine green (ICG) retention rate at 15 minutes (R 15) in patients with liver disease. For the Bayesian analysis, the mean and variance of parameters, the disappearance rate (K) and the distribution volume, were calculated by the one compartment analysis with data of inpatients. The mean value of the disappearance rate (K) was shown to be smaller and the variances of parameters of the patients were larger than normal values reported, so that it was suggested that the studied group included patients with various kinds of liver diseases. Accordingly, the Bayesian analysis was performed using above statistical results. The distribution volumes, calculated from three points measurements by Bayesian method, were estimated smaller and the initial concentrations higher than those obtained by the one compartment analysis. However, the retention rate (R 15) were well correlated the results of one compartment analysis. The Bayesian analysis using one point measurement at 15 minutes, resulted that the values of retention rate (R 15) were shown about 17% lower, but well correlated with the coefficient gamma = +0.9972 to those obtained by usual method. The disappearance rate (K), which calculated simultaneously from the one point analysis, showed the lowest value on liver cirrhosis. So that, the application of Bayesian analysis to the one point measurement of ICG test was useful to clinical evaluation of liver disease.

Bayes Theorem↗

PubMed1989

Model for clonal elimination in the thymus.

A thymic stromal cell clone, MRL104.8a, expresses class I as well as class II H-2k antigens after exposure to gamma-interferon. This clone also produces thymic stroma-derived T-cell growth factor (TSTGF), which is distinct from other known interleukins and is capable of promoting the growth of various antigen-specific helper T cell (Th) clones without requiring a specific antigen or interleukin 2. When the keyhole limpet hemocyanin (KLH)-specific, I-Ek-restricted Th clone 9-16 was cultured on an Ia (I-Ak and I-Ek)-expressing MRL104.8a monolayer, potent proliferation of the 9-16 cells was induced by TSTGF produced by the monolayer. In contrast, the addition of KLH resulted in lethal growth inhibition of Th clone 9-16 cells. Another Th clone that is KLH-specific but I-Ab-restricted was capable of proliferating on the Iak-expressing MRL104.8a monolayer whether or not KLH was present. More importantly, death of Th clone 9-16 cells cultured on a MRL104.8a monolayer in the presence of KLH was almost completely prevented by the addition of anti-I-Ek or anti-CD3 monoclonal antibodies, which are capable of blocking antigen recognition by the T-cell receptor. However, when Th clone 9-16 cells were cultured in the presence of KLH but on a monolayer of MRL28.8a cells, another thymic stromal clone that expresses a comparable amount of I-Ek antigen but produces a marginal amount of TSTGF, cells did not die; a lethal effect was induced by adding TSTGF. These results indicate that the TSTGF-producing and Ia-expressing thymic stromal cells induce the continuous proliferation or selective elimination of each T-cell clone, depending on whether the T-cell receptor is stimulated by the relevant antigen associated with Ia molecules expressed on the stromal cell surface.

Animals↗

PubMed1985

Biomechanical behavior of the posterior elements of the lumbar spine under loading--a study of stress analysis by means of three dimensional photoelastic experiments.

To investigate the biomechanical behavior of the lumbar posterior elements under loading, stress analysis was carried out. The three dimensional photoelastic method was used for stress analysis in this study. The forces applied to the superior and the inferior articular facets were concentrated on the pars interarticularis and transmitted to the pedicle. However, almost no stress was generated in the lamina. Highly stressed areas were found in the pars interarticularis and around the lateral recess. The highest compressive stress was present in the pars interarticularis. The deformation pattern of the lumbar spinal canal was recognized and it became flat as the lateral recess was narrowed and deepened. These results very interestingly correspond to the fact that spondylolysis and lumbar canal stenosis are found in the above-mentioned areas clinically.

Biomechanical Phenomena↗

PubMed1981

[The pathologico-anatomic study of the metastatic tumor of the spine (author's transl)].

The radiological and histological studies were performed on the three spinal column obtained at autopsy from cases with metastatic tumors to the spine with complete paralysis treated surgically. These three cases consisted of a maxillary carcinoma with metastasis to the cervical spine, a seminoma with metastasis to the thoracic spine and a metastasized renal cell carcinoma to the thoracic spine. All patients died without recovery from the paralysis, in spite of the immediate tumor resection and spinal fusion were done immediately after the appearance of complete paralysis. The histological examination of cross section of these spinal column showed that tumor cells infiltrated in the vertebral body and spinal canal, and spinal cord was remarkably compressed by the tumor. Therefore, various degrees of degeneration were seen in the spinal cord. In addition, many tumor-cell emboli were seen in veins of vertebral body and spinal canal in two cases, and also tumor cell infiltration to an intradural space and marked deformity of the spinal cord were seen in one case. These above findings would suggest that tumor cells, which metastasized to vertebral body through venous plexus from the primary lesion, infiltrated into the spinal canal, compressed spinal cord and caused paralysis.

Female↗

PubMed1979