PubMed Health⌕ Search

Biomedical subjects

T Jimbo

Publications and source records attributed to T Jimbo.

43 records · Page 3Linked to original sources
PubMed1984

[Studies on the relationship between quantitative histometry and obstetric complications].

Quantitative histometry of the placenta seems to make it possible to correlate the histopathological changes with various obstetric complications and disorders more precisely. In the present paper, the relationship between the histopathological changes in the placenta and the obstetric complications was investigated by quantitative histometry based on the standardized categories with uncomplicated normal cases as the controls. Among the obstetric complications, special emphasis has been placed on the pregnancies complicated by toxemia of pregnancy and diabetes mellitus. The obstetric disorders of postmature pregnancy and prolonged delivery have also been related to the quantitative histometry. It was revealed that the cytotrophoblast proliferation associated with the formation of syncytial knots was a very common finding both in toxemia and in these obstetric disorders. However, there was a great difference between the two in that impairment of the vasculature was highly specific in the placentae in the case of toxemia. The most conspicuous histopathological change recognized in the placentae due to diabetes was villous edema, which would be due to the osmotic imbalance. However, it is so unusual to find cases complicated by severe diabetes that typical villous edema is rarely observed. The quantitative approaches in the field of histopathology may leave some problems in that the specimens taken from the organ could not always be representative of the whole organ. However, quantitative histometry based on the fairy standardized categories has been shown to offer more promising information on the relationship between the histopathological changes in the placentae and the obstetric disorders.

Female↗
PubMed1981

Multicentric reticulohistiocytosis. Electron microscopic and ultracytochemical studies.

Lesions from a patient affected with multicentric reticulohistiocytosis (MR) were studied by ultracytochemical techniques to determine the relationship of PAS-positive materials and/or acid phosphatase (AP) activity to electron-dense granules found in the large mononucleated or multinucleated giant cells that are characteristic of this entity. The lead phosphate reaction products that mark the sites of AP activity were found in the electron-dense granules. The granules were also PAS positive by the periodic acid-thiosemicarbazide-silver proteinate method. These findings suggest that the PAS-positive and diastase-resistant materials in the large mononucleated or multinucleated giant cells of MR are not phagocytized materials but are pre-existing lysosomes.

Adult↗
PubMedDate not supplied

DT-5461a, an antitumor synthetic lipid a analog, causes selective blood flow reduction in tumor tissue.

We previously reported that a synthetic low-toxicity lipid A analog, DT-5461a, exhibited a significant antitumor effect was characteristically accompanied by extensive tumor necrosis, suggesting that DT-5461a causes a local circulatory disturbance in tumor tissues. In this study, we investigated the effect of DT-5461a on regional blood flow in various organs including tumor tissue with a radiolabeled tracer-distribution technique using 14C-iodoantipyrine. Intravenous administration of DT-5461a induced blood flow reduction in Meth A tumor subcutaneously implanted into BALB/c mice, but not in liver, spleen or lung of these mice. This tumor tissue-specific reduction in blood flow was significantly inhibited by pretreatment with antisera against tumor necrosis factor (TNF) alpha, interferon (IFN) alpha/beta, and IFN gamma. These results indicate that endogenously induced cytokines, namely TNF alpha and IFNs, are involved in the intratumor blood flow reduction caused by DT-5461a.

Animals↗
PubMedDate not supplied

Systemic administration of a synthetic lipid A derivative, DT-5461a, reduces tumor blood flow through endogenous TNF production in hepatic cancer model of VX2 carcinoma in rabbits.

Intravenous administration of DT-5461a, synthetic low-toxicity lipid A derivative, significantly inhibited the growth of VX2 tumor transplanted in the liver of rabbits. DT-5461a induced high levels of TNF activity in tumor tissue from 30 to 60 min after the administration, while no TNF activity was detected in the adjacent nontumorous liver tissue. Simultaneous measurement of microcirculatory blood flow in both tumorous and nontumorous regions in the liver by laser doppler velocimetory revealed that intravenous administration of DT-5461a caused a significant blood flow reduction in tumor region, but not in nontumorous counterparts. Tumor blood flow was significantly reduced by 40 to 60% at 30 to 90 min after the DT-5461a administration as compared with preadministration value. In contrast, local administration of human recombinant TNF alpha through the hepatic artery induced blood flow reduction not only in tumor region but also in nontumorous liver tissue. These results suggest that systemic administration of DT-5461a induced selective tumor microcirculatory blood flow reduction via local endogenous TNF production.

Animals↗