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Biomedical subjects

H Shimada

Publications and source records attributed to H Shimada.

At least 793 records · Page 44Linked to original sources
PubMed1988

Mutagenicity studies of muroctasin.

A synthetic muramyl dipeptide derivative N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L18), muroctasin) was studied for mutagenicity using the Ames method, in vitro cytogenetics and micronucleus test. MDP-Lys(L18) had no mutagenic effect on S. typhimurium (TA1535, TA1537, TA1538, TA98 and TA100) or E. coli (WP2 uvrA) in the reverse mutation assay. In the cytogenetic study, MDP-Lys(L18) had no effect on the chromosomes of the Chinese hamster cells at cytotoxic doses. Single subcutaneous treatment of MDP-Lys(L18) at dose levels of 3.5, 35 or 350 mg/kg in the mouse micronucleus test did not increase the incidence of micronucleated polychromatic erythrocytes. These results show that MDP-Lys(L18) has no demonstrable mutagenic potential.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Pathology of fatal rhabdomyosarcoma. Report from Intergroup Rhabdomyosarcoma Study (IRS-I and IRS-II).

Patterns of tumor spread were studied by examining clinicopathologic and postmortem data on 274 tumor-related deaths from patients in IRS-I and IRS-II. The activity of the primary lesion and presence or absence of distant metastases at death were related to the histologic subtype and anatomic site of origin, individually and/or in combination. The alveolar subtype had the highest proportion of distant metastases and the lowest occurrence of local progression alone from the primary site. More distant metastases were observed among the patients with extremity primary, and the frequency increased significantly with the alveolar histologic subtype. Parameningeal tumors, irrespective of their histologic subtypes, showed a high incidence of direct extension from the primary lesion especially into the CNS. The lung was the most common site of metastasis at death, followed by the regional lymph node, bone, liver, and brain. Regional node involvement was observed more commonly in patients with lower extremity primary and alveolar subtype.

Autopsy↗
PubMed1987

Experience with percutaneous transhepatic fiberoptic choledochoscopy for retained stones in the biliary tract. Report on 15 patients.

Residual choledochal stones in 11 patients and stones in the intrahepatic bile ducts in 5 patients were successfully removed by the use of the fiberoptic choledochoscope (FCH-6T), introduced percutaneously into the intrahepatic biliary tract. The reasons for the use of percutaneous transhepatic extraction were: (1) unsuccessful endoscopic papillotomy; (2) unsuccessful choledochoscopic removal via the T-tube tract; (3) high surgical risk; (4) the presence of percutaneous transhepatic biliary drainage for acute cholangitis and acute pancreatitis. All stones were extracted through the liver or the papilla of Vater after crushing them. All minor complications such as pain, vomiting, or fever resolved without further therapy. Percutaneous transhepatic choledochoscopy proved safe and effective for the removal of retained choledochal stones and was essential for the treatment of stones in the intrahepatic bile ducts.

Aged↗
PubMed1987

Neurofibrillary tangles in human upper cervical ganglia. Morphological study with immunohistochemistry and electron microscopy.

Neurofibrillary tangles (NFTs) are one of the main pathological hallmarks of Alzheimer's disease or senile dementia, and are seen in the cerebral cortex and some other nuclei in the central nervous system (CNS). No NFTs have been reported in the human peripheral nervous system, although NFTs were recognized in the dorsal root ganglion of the aged rodents. We report here the presence of NFTs in the upper cervical ganglia (UCGs), but not in the stellate nor in the celiac ganglia, of an elderly patient, who was not demented and had only minimal senile changes in the CNS. Immunohistochemically the antibodies to microtubule-associated protein 2, paired helical filaments and ubiquitin stained positively the NFTs in the UCGs. On electron microscopic examination a periodical twisted pattern of the filaments was identified; these findings suggest that the NFTs of the UCGs have just the same properties as those of the cerebral cortex. This is the first report of the demonstration of NFTs in the peripheral ganglia and might contribute to the study of mechanism of NFT production.

Aged↗
PubMed1987

Peculiar pattern of glial fibrillary acidic protein production in extracranial metastatic tumor cells of malignant astrocytoma.

An 83-year-old woman suffered from malignant astrocytoma originating in the temporal lobe. Autopsy revealed its extracranial metastasis to the liver, lung and bone marrow. The tumor tissue at the primary site was composed of plump, process-forming cells and small cells with scanty cytoplasm, and showed dural invasion. In the metastatic areas, most of the tumor cells were small cells, although proliferation of the plump cells in contact with perivascular connective tissue was marked, particularly in the liver. These plump cells were positively stained with antiserum to glial fibrillary acidic protein (GFAP), showing that the collagenous tissue was able to induce increased production of GFAP by the glial tumor cells.

Aged↗
PubMed1987

AP4A-hydrolysing activity in sea urchin embryos.

The enzyme activity hydrolysing diadenosine 5,5'-P1, P4-tetraphosphate (AP4A) was demonstrated in the embryonic extract of sea urchin. The enzyme activity was preferentially inhibited by ZnCl2 and by high concentrations of isobutylmethylxanthine, indicating that two types of the enzyme, (AP4A) hydrolase and non-specific phosphodiesterase, are related to the degradation of (AP4A) in sea urchin embryos. The (AP4A)-hydrolysing activity was not detectable in the unfertilized eggs because of the presence of a high-molecular weight (HMW) and thermolabile inhibitory factor. Though the enzymes were activated immediately after fertilization, no cell cycle-dependent fluctuations in their activities were observed.

1-Methyl-3-isobutylxanthine↗
PubMed1987

Decreased VLDL apoprotein CII/apoprotein CIII ratio may be seen in both normotriglyceridemic and hypertriglyceridemic patients on chronic hemodialysis treatment.

Pathogenetic factors that may be related to uremic hypertriglyceridemia were studied in 27 patients who had been undergoing chronic hemodialysis treatment for over two years. They were divided into two groups consisting of 14 hypertriglyceridemic (HTG) patients with fasting serum triglycerides (TG) of 170 mg/dL or higher, aged 45 +/- 11 yr (mean +/- SD) and 13 normotriglyceridemics (NTG) with serum TG less than 170 mg/dL aged 42 +/- 9 yr. Serum lipid, lipoprotein [low density lipoprotein (LDL) and very low density lipoprotein (VLDL)] and apoprotein (Apo) levels, as well as ultracentrifugally obtained VLDL apo subfractions and serum carnitine were compared between the two groups, which enabled us to rule out various factors inherent to uremic state and present in both groups. The HTG group of patients, who showed (by definition) significantly elevated TG (300 +/- 167 mg/dL v 123 +/- 30 mg/dL in NTG) and VLDL levels, concomitantly showed significantly increased serum total cholesterol (P less than .001) and LDL (P less than .001), and significantly decreased apo AI/apo B, or an index of risk of atherogenesis (P less than .05). Serum apo CII (7.3 +/- 3.3 mg/dL v 3.6 +/- 1.0 mg/dL in NTG), apo E (4.8 +/- 2.8 mg/dL v 2.9 +/- 1.3 mg/dL) and VLDL/serum apo CII (38 +/- 18 v 22 +/- 12), ie, the amount of VLDL covered by a unit of apo CII, were elevated in the HTG compared with the NTG group of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Mutagenicity studies with N6, O2'-dibutyryl cyclic adenosine 3',5'-monophosphate (DBcAMP).

N6,O2'-Dibutyryl cyclic adenosine 3,5-monophosphate (DBcAMP) was studied for mutagenicity using the rec assay, the Ames method, and in vitro cytogenetics. DBcAMP had no mutagenic effect on B. subtilis in the rec assay, or on S. typhimurium (TA1535, TA1537, TA1538, TA98 and TA100) or E. coli (WP2 uvrA). In the cytogenetic study, a significant increase in chromosomal aberrations was observed at a concentration of 50,000 micrograms/ml, but it was considered that this effect could be attributed to the secondary effect of the high osmotic pressure in the culture medium. These results suggest that DBcAMP has no mutagenic potential.

Animals↗