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Biomedical subjects

S Tachikawa

Publications and source records attributed to S Tachikawa.

At least 55 records · Page 3Linked to original sources
PubMed1990

A tubular bioreactor for high density cultivation of microorganisms.

By simulating the functions of the animal intestine, the authors have developed a novel tubular bioreactor (TBR) which is capable of containing both the reaction and separation of products in a single system. This reactor consisted of inorganic ultra filtration membrane modules in the primary part of the system, a heat exchanger and a recycling pump. The operation characteristics of the TBR were studied by cultivating Lactobacillus casei at a laboratory scale. The cell density obtained was up to 10 times higher than the density obtained by using the conventional jar fermentor. Furthermore, 40 g l-1 of cell mass was obtained in only 14 hours with 20 l of fresh medium when the dilution rate was increased according to the cellular growth. Afterwards, the cultivation time and the volume of fresh medium were reduced to 44% and 74%, respectively, of the values in the cultivation operation at constant dilution rate.

Bacteriological Techniques↗
PubMed1989

[Comparison between PVHIS on the MRI and the permeability of brain blood vessels in elderly patients].

The degree of PVHIS (periventricular high intensity signal) on the MRI was composed with the permeability of brain blood vessels using the cerebrospinal fluid (CSF)/serum ratio for albumin, and the CSF/serum ratio for IgG in elderly patients. The 47 elderly patients (mean age = 79.9) were divided into three groups: (1) Mild group (20 cases, M:6, F:14, mean age = 75.8), (2) Moderate group (18 cases, M:7, F:11, mean age = 82.6), (3) Severe group (9 cases, M:2, F:7, mean age = 82.9), in accordance with the degree of PVHIS on the MRI. The MRI was operated at a field strength of 0.22 tesla. The pulse sequence (used on all patients) had a repetition times (TR) of 2,000 msec and a time to echo (TE) of 40 msec. The levels of albumin and IgG in the serum and CSF were measured. The CSF/serum ratio for albumin was used of analyze the permeability of the brain blood vessels in each group. There was no significant difference in the level of the serum albumin, the CSF albumin, the serum IgG, the CSF IgG and the CSF/serum ratio for IgG among the three groups. The same was found to be true for the IgG index which indicates the synthesis of immunoglobulin in the central nervous system. However, there was a statistically significant difference (p less than 0.05) in the CSF/serum ratio for albumin between groups (1) and (3). The increased CSF/serum ratio for albumin in the severe group indicated there were confluent lesions involving the entire extent of the periventricular white matter on the MRI. This suggested an increased permeability of brain blood vessels which revealed the dysfunction of the blood brain barrier due to affected cerebral endothelial cells in capillaries.

Aged↗
PubMed1989

Malignant spindle cell tumor of the pericardium. Evidence of sarcomatous mesothelioma with aberrant antigen expression.

A case of malignant spindle cell tumor occurring in the pericardium is presented. The tumor arose from the pericardium of a 51-year-old Japanese woman with no history of exposure to asbestos. The tumor extended into the pericardial and left pleural cavities. The primary and metastatic tumors consisted of fusiform cells with frequent mitoses. Ultrastructurally, the tumor cells possessed a discontinuous external lamina, cytoplasmic processes, microfilaments and desmosomal intercellular junctions. Immunohistochemical examination showed that most tumor cells were positive for Leu 7, and several for S-100 and glial fibrillary acidic protein. Unexpectedly, most of the tumor cells also expressed keratin. These findings favor a diagnosis of sarcomatous mesothelioma with aberrant antigenic expression or heterogeneous differentiation of neoplastic cells.

Female↗
PubMed1989

Epithelioid malignant schwannoma. A case report.

A case of epithelioid malignant schwannoma (EMS) is reported. The tumor arose in the left radial nerve at the axillary fossa of a 65-year-old male. A few months after resection of the primary axillary tumor, several intrapulmonary metastases appeared. Microscopically, the primary tumor showed highly cellular areas of polygonal or rounded cells, resembling lymphoma or melanoma, while the metastatic tumors revealed cord formation or rows, resembling carcinoma. Immunohistochemical studies showed that some of these tumor cells contained S-100 protein. Ultrastructurally, these tumor cells revealed delicate cytoplasmic projections, which contained bundles of microfilaments. However, the tumor cells did not have melanosomes. Varying amounts of basal lamina material surrounded the tumor cells. From the above features, we obtained a correct diagnosis of EMS.

Aged↗
PubMed1988

Early gastric cancer of the small cell type.

A case of early gastric cancer of the small cell type is presented. The small cell carcinoma was situated in the antrum and arose in association with well-differentiated adenocarcinoma. Well-differentiated adenocarcinomas were limited to the mucosa, whereas small cell carcinoma infiltrated into the submucosa with evident vascular invasion. Small cell carcinoma revealed argyrophilia and focal squamous cell differentiation. The patient died of massive hepatic metastasis of small cell carcinoma 6 months later. We will describe clinicopathological features of our case and review the literature.

Aged↗
PubMed1987

IgM antibody production in mice intraperitoneally injected with zirconium oxychloride.

The effect of zirconium (Zr) on the humoral immune response was studied by measuring the level of IgM-plaque forming cells (IgM-PFC) against sheep red blood cells (SRBC) in the spleen of C57 BL mice intraperitoneally injected with zirconium oxychloride. Two experiments, a single injection of zirconium oxychloride of 1/5, 1/10, 1/50, and 1/100 of the LD50 for intraperitoneal injection and continuous injection of 1/20, 1/40, and 1/80 of the LD50 every other day for two or four weeks in mice, were carried out. In the case of a single injection zirconium oxychloride was intraperitoneally injected on days -1, 0, +1, +2, and +3 in relation to SRBC immunisation. The following conclusions may be drawn from this study: (1) Zr was shown to have an adjuvant like activity in relation to the humoral immune response, at least to IgM antibody production; (2) this effect was recognised not only with a single injection with Zr but also after continuous injection; (3) a single injection of Zr was more effective when the mice were treated with Zr 24 hours before or after SRBC immunisation; and (4) with regard to an injected dose of Zr, it was shown that a lower dose (1/50, 1/100 of the LD50 for a single injection and 1/40, 1/80 of the LD50 for continuous injection) led to a more enhanced level of IgM-PFC than a higher dose (1/5, 1/10 of the LD50 for a single injection, and 1/20 of the LD50 for continuous injection).

Animals↗
PubMed1987

[Aplastic anemia and occupational factors in Japanese industries].

Four mail questionnaire surveys were conducted on the incidence of aplastic anemia among industrial workers throughout Japan in collaboration with industrial doctors during a period from 1970 to 1983. The following major results were obtained. 1. Response rates were 55.5% (874/1,574 enterprises) in the first mail questionnaire survey in 1970-1972, 65.3% (294/450) in the second survey in 1973, 49.1% (170/346) in the third survey in 1976-1980, and 76.6% (242/316) in the fourth survey in 1981-1983. There was no significant difference in industrial types among the four surveys. 2. The numbers of aplastic anemia patients newly diagnosed were 145 (112 males/33 females) in the first survey, 21 (16/5) in the second survey, 51 (41/10) in the third survey and 30(24/6) in the fourth survey. Incidence rates per million were 14.7 (14.4 males/15.5 females) in the first and second survey, 14.2 (13.5/18.3) in the third survey and 9.1 (8.6/11.9) in the fourth survey. The rates were almost constant from 1970 through 1980, but the rates decreased thereafter. The rate was higher in females than in males, but the difference was not significant. 3. Incidence rates were high in rubber industry (26.8 per million), paper industry (24.8), and petroleum industry (22.5), but there was no industrial type demonstrating a constantly higher incidence in every survey. Manufacturing industries showed a higher incidence (14.6) than nonmanufacturing industries (11.7). 4. By type of work, non-productive work (67.2%), i.e., clerical (30.8%), administrative (8.9%), technical (7.7%), were the main jobs of 247 registered aplastic anemia patients (193 males and 54 females). 5. Thirty patients had been exposed to noxious agents such as organic solvents (21 cases including 3 exposed to benzene), metals (6), and radiation (1). However, in these cases no causal relationship between exposure and disease onset could be demonstrated. 6. Thirty-nine cases had a drug-intake history before onset of the disease. Drugs given included chloramphenicol (4 cases), other antibiotics (4), antituberculosis agents (8), analgesics (6), and tranquillers (4). The results obtained revealed no positive evidence that occupational factors peculiar to Japanese industries were involved in triggering aplastic anemia.

Adult↗
PubMed1987

[A study on the immunologic effects in workers exposed to low levels of toluene-diisocyanate (TDI)].

Forty-three workers exposed to low levels of toluene diisocyanate (TDI) during the process of producing polyurethane forms were examined immunologically for IgG, A, M, and E and serum enzyme activities such as serum angiotensin converting enzyme (SACE), serum lysozyme (SLZM) and glycylproline dipeptidyl aminopeptidase (GP-DAP). Air concentration of TDI was annually measured in various places of work during the past five years from 1979 to 1983. The results obtained in the present study were as follows. 1. The air concentration of TDI at all places of work was below the permissible concentration level of 0.02 ppm throughout the study period. 2. Subjective symptoms and abnormal findings on chest X-ray considered directly related to TDI exposure were not observed. 3. No remarkable abnormal findings in blood cell counts and in serum biochemical studies could be seen in any of the workers. 4. The serum IgG levels in workers directly exposed to TDI were significantly higher (p less than 0.05) than those in workers indirectly exposed to TDI and in non-exposed workers. 5. In the study of serum enzymatic activity, SLZM activity in workers exposed directly to TDI was significantly higher (p less than 0.01) than those in workers indirectly exposed to TDI and in non-exposed workers.

Adult↗
PubMed1986

Extraskeletal myxoid chondrosarcoma arising from the retroperitoneum.

A case of extraskeletal myxoid chondrosarcoma is presented. The tumor occurred in the retroperitoneum and systemic metastases were found at autopsy. The primary and metastatic tumors were soft and strikingly myxoid on gross appearance. Microscopic observation revealed undifferentiated malignant tumor having large amounts of myxoid substance and a small amount of well-differentiated chondrosarcoma element in the primary lesions. The authors obtained an immunohistochemical result that the tumor cells showed positivity for alpha-1-antitrypsin and alpha-1-antichymotrypsin. Regarding S-100 protein, the well-differentiated chondrosarcoma element revealed intense positivity, whereas the poorly differentiated myxoid areas were not positive except for a few tumor cells. This is the first case, to our knowledge, of extraskeletal myxoid chondrosarcoma arising from the retroperitoneum, and immunohistologic findings suggest that alpha-1-antitrypsin and alpha-1-antichymotrypsin may be available markers in poorly differentiated chondrosarcomas showing a negative reaction for S-100 protein.

Chondrosarcoma↗