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T Fujita

Publications and source records attributed to T Fujita.

At least 19 recordsLinked to original sources
PubMed1979

The role of C4-binding protein and beta 1H in proteolysis of C4b and C3b.

Two forms of C4-binding protein (C4-bp) (C4-bp low, C4-bp high), which differ slightly in net charge and apparent molecular weight, as determined by SDS- PAGE, were separated by ion-exchange chromatography and contaminants removed with specific antisera. Both forms of C4-bp served as cofactors for the cleavage of C4b in solution by C3b inactivator, and the resulting fragments of the a'-chain of C4b had identical molecular weights. In addition, similarly to beta1H, C4-bp low or high served as cofactors for the cleavage of fluid phase C3b by C3bINA. However, important quantitative differences between the activities of C4-bp and beta1H were observed. With regard to C3b in solution, the cofactor activity of beta1H was {approximately equal to}20 times greater than that of C4-bp on a weight basis. In relation to cell-bound C3b, the differences in activity were even more marked. Whereas beta1H enhanced the effects of C3bINA on the erythrocyte intermediate EC3b, inhibiting the assembly of EC3bBb, C4-bp was without effect even at concentrations {approximately equal to}300 times greater than beta1H. Therefore, under physiological conditions, it is likely that beta1H is the key protein which controls the function of C3b, and that C4-bp activity is directed mainly toward the cleavage of C4b. We also examined the relation between C4-bp and the C3b-C4bINA cofactor described by Stroud and collaborators (3, 4). By functional, physico-chemical and immunological criteria, they are the same protein.

Complement C3↗
PubMed1979

[Motilin].

Explore the source record for details and available documents.

Gastrointestinal Hormones↗
PubMed1979

Three dimensional organization of mammalian adrenal cortex. A scanning electron microscopic study.

The adrenal cortex of different mammals was studied by SEM in order to demonstrate its actual three-dimensional organization. In the rat, as well as in the cat and pig, the adrenal cortex appeared as a "tunnelled continuum" of polyhedral cells arranged in plate-like structures (laminae). This laminar arrangement was more evident in the inner fasciculate and reticular zones where the cortex revealed a striking similarity to liver tissue. The polyhedral cells of all cortical zones possessed regular facets populated by small pits, larger invaginations and numerous microvilli with the exception of very short and smooth areas probably corresponding to attachment zones and/or gap junctions. This cellular architecture produced a labyrinthic system of intercellular channels or lacunae in which the capillaries were suspended. The pericapillary areas of this labyrinth contained microvilli, amorphous material, a delicate net of fibrils and occasional cells. The intercellular compartment of this lacunar system was mainly bordered by numerous microvilli arising from endocrine cells. The luminal surface of the capillary wall showed not only irregularly protruding margins (interpretable as endothelial junctions) but also clearly overlapping and flattened endothelial extensions. In all the animals and areas of the adrenal cortex examined, the endothelial wall was provided with abundant clusters of small fenestrations (about 50 nm in diameter) generally arranged in sieve plates. Larger fenestrations were noted mainly in the fasciculate and reticular zones of the cat and pig and occasionally in the rat. A final point related to the nature and significance of sinusoidal fenestrations was the occurrence of irregularly shaped and intracapillary located cells mainly noted in the deeper zones of the fasciculate and reticular zones of the gland. These elements--possessing the surface characteristics of macrophages--were observed, with their irregular and slender evaginations, in close proximity to the large fenestrations in a manner reminiscent of Kupffer cells within the lumen of liver sinusoids.

Adrenal Cortex↗
PubMed1979

Somatostatinoma of the duodenum.

An adenocarcinoma of the second portion of the duodenum in a 26-year-old male is presented. The patient was suffering from pain in the epigastrium. Immunofluorescent studies revealed that it consisted almost exclusively of cells with a distincly positive somatostatin-like immunoreactivity. Ultrastructurally, the cytoplasm of the tumor cells had numerous large round granules (about 400 micrometers) with variable electron density. Most of these cells closely resembled the D cells normally seen in the duodenum and the islets of the pancreas, although a few argyrophil cells could be demonstrated by light microscopy. Radioimmunoassay of extracts of the tumor revealed a large amount of somatostatin (2260 pg/mg); substance P and VIP were detected also. Somatostatinoma has been known to occur in the pancreas, but this seems to be the first somatostatinoma found in the intestine.

Adenocarcinoma↗
PubMed1979

Modulation of the classical pathway C3 convertase by plasma proteins C4 binding protein and C3b inactivator.

We recently described the isolation from human serum of a serum protein (C4 binding protein) that functions as an essential cofactor for C3b inactivator in the proteolysis of fluid-phase C4b and to a much lesser extent, C3b. We show here the role of C4 binding protein in the formation and function of the classical pathway C3 convertase (C42). C4 binding protein interferes with the assembly of the membrane-bound C3 convertase of the classical pathway and accelerates the decay of C42 in a dose-dependent fashion. Its removal from serum by means of specific immune absorption promotes the vigorous consumption of C3 after addition of C1; this effect is abolished by reconstitution with purified C4 binding protein. Although C4 binding protein inhibits the hemolytic function of cell-bound C4b, we did not detect any change in the structure of C4b even after prolonged incubations of EAC14 with C4 binding protein. For this reason, and on the basis of studies of the time required for maximal reactivity (Tmax) of cellular intermediates generated in the presence of C4 binding protein and limited amounts of C2, we conclude that the effects of C4 binding protein are probably mediated by displacing C2a from specific binding sites on C4b. In addition, C4 binding protein enhances the cleavage by C3b inactivator of the alpha' chain of cell-bound C4b. When EAC14 cells were incubated with both control proteins, the Tmax of the cells was prolonged and the lysis was markedly diminished. We conclude that C4 binding protein and C3b inactivator control the C3 convertase of the classical pathway in a fashion similar to that described for beta 1H and C3b inactivator in the alternative pathway.

Animals↗
PubMed1979

Attenuation of the diuretic effect of dopamine by droperidol in man and dogs.

The effects of dopamine 0.5--6.0 microgram kg-1 min-1 on urine flow and the excretion of sodium and inorganic phosphate were studied in patients and dogs. In both the patients and the animals the diuretic effect of dopamine was augmented by the i.v. administration of droperidol 0.25 mg kg-1. Similarly, the excretion of sodium and inorganic phosphate was increased by droperidol.

Adult↗
PubMed1979

Successful visualization of cortical malignant lesions on renal scintigram using 99mTc-dimercaptosuccinic acid.

The early (dynamic) and late (static) renal images obtained with 99mTc-dimercaptosuccinic acid (DMSA) were utilized to evaluate renal cortical malignant tumors in 30 cases of renal cell carcinoma each of which had been confirmed by operation or autopsy. Early images, performed 20--50 seconds after radionuclide administration, demonstrated abnormal vascular pools in the cortex. A cold area without DMSA uptake was demonstrated on the 2-hour or late images, reflecting a non-functioning renal mass. Lesions demonstrated with combined early and late images showed a good correlation with those demonstrated by renal angiography in 25 out of 27 cases. However, when almost all the renal tumor was replaced by necrotic lesions, the early image did not reveal hypervascularity. When a highly vascular renal tumor extended to the perinephric tissues, the tumor area was sometimes overestimated on the early image. It is almost impossible to diagnose renal cell carcinoma using radionuclide imaging alone. However, 99mTc-DMSA renal studies, using both early and late imaging, have proven to be a useful, noninvasive adjunct in the detection of malignant cortical lesions.

Adenocarcinoma↗
PubMed1979

Accumulation of 201Tl-chloride in a parathyroid adenoma.

A 201Tl-chloride sacn was performed on a patient with primary hyperparathyroidism. 201Tl-chloride accumulated in the region of the right lower thyroidal pole and a diagnosis of parathyroid adenoma was confirmed intraoperatively. 201Tl-chloride imaging of a hyperfunctioning parathyroid gland seems to be useful for the detection and preoperative localization of a parathyroid adenoma.

Adenoma↗
PubMed1979

Priming increases the amount of interferon mRNA in poly(rI).poly(rC)-treated L cells.

Priming by mouse interferon pre-treatment resulted in an accumulation of interferon mRNA in poly(rI).poly(rC)-treated L cells, starting early in the period of interferon synthesis. On electrophoresis, the priming activity of an interferon preparation co-migrated with the antiviral activity, which suggests identity of the functional principle(s) for these activities.

Animals↗