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Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 919 records · Page 51Linked to original sources
PubMed1984

4-Hydroxy-3-nitrophenyl (NP) acetyl-hapten specific lymphocyte proliferation. I. Mice bearing Igh-1b allotype can cross-react with 4-hydroxy-5-iodo-3-nitrophenyl (NIP) acetyl hapten.

Hapten specific T cell proliferation was induced in several strains of mice. When lymph node T cells from 4-hydroxy-3-nitrophenyl acetyl-keyhole lympet hemocyanin (NP-KLH)-primed mice were stimulated in vitro with NP-polymer glutamic acid-lysine-phenyl alanine (NP-GL phi) or NP-ovalbumin (NP-OVA), they displayed a good level of proliferative responses. It was observed that NP-GL phi could induce NP-hapten specific proliferation even with NP-KLH lymphocytes from GL phi nonresponder strains. NP-KLH primed lymphocytes from C57BL/6 (H-2b, Igh-1b), CKB (H-2k, Igh-1b), CWB (H-2b, Igh-1b), and B10.BR (H-2k, Igh-1b) mice showed good proliferative responses to both 4-hydroxy-5-iodo-3-nitrophenyl (NIP) acetyl-GL phi and NIP-OVA antigens. However, NP-KLH primed lymphocytes from C3H/He (H-2k, Igh-1j) and C3H. SW (H-2b, Igh-1j) mice displayed poor proliferative responses to NIP-GL phi and NIP-OVA antigen. These results suggested that the gene coding for the NIP-cross-reaction might be mapped in the Ig heavy-chain linked locus.

Animals↗
PubMed1984

Ultrastructures of leuco-adsorption on monolayers infected with influenza virus.

Leuco-adsorption occurring in influenza virus infected-cell cultures was studied morphologically to clarify the mechanisms of adsorption of leukocytes. Among the various types of chicken leukocytes studied, such as lymphocytes, monocytes, granulocytes, and thrombocytes, all were found to adhere to the virus-infected cells. The adsorption seems to occur through at least two processes, one is mediated by microvilli (microvillus-attachment), and the other is direct adherence of both cells (cell-to-cell-attachment). In the former, the leukocytes are bound to the microvilli protruding from the infected MDCK cells and in the latter both cell membranes attach directly. In the cell-to-cell-attachment, there was an electron-lucent gap of about 12 nm in width in the intermembranous space of the junctional regions. This region was similar morphologically to the gap junction. As a result of leucoadsorption no cytolytic effects occurred in the MDCK cells under the experimental conditions.

Adsorption↗
PubMed1984

Bacteriological study of periodontal lesions in two sisters with juvenile periodontitis and their mother.

A total of five bacteriological samples from the periodontal pockets of two sisters with localized juvenile periodontitis and their mother with advanced periodontitis was studied. Gram-negative anaerobic rods were predominant in the samples. Bacteroides intermedius and Bacteroides loescheii were the most predominant species. The antigenicity and bacteriocinogenicity of these isolates were quite similar. Serum immunoglobulin G antibody levels of the subjects to gram-negative periodontopathic bacteria were measured by using the micro-enzyme-linked immunosorbent assay. The levels of antibodies to saccharolytic black-pigmented Bacteroides species were significantly higher than the levels in healthy young females.

Adolescent↗
PubMed1984

Immunoglobulin G response to subgingival gram-negative bacteria in human subjects.

Serum and gingival crevicular fluid from normal healthy adults and patients with periodontitis were screened for immunoglobulin G antibodies to antigens from Bacteroides gingivalis 381, Bacteroides intermedius 24, Bacteroides loescheii ATCC 15930, Fusobacterium nucleatum ATCC 25586, Eikenella corrodens 1073, Actinobacillus actinomycetemcomitans ATCC 29522, and Capnocytophaga sp. strain M-12. Immunoglobulin G antibody titers to the antigens were measured by an enzyme-linked immunosorbent assay. The antibody levels to B. gingivalis in serum and gingival crevicular fluid were significantly higher in the samples from patients with periodontitis than in samples from healthy individuals. Although there were individual differences within patient groups, a positive correlation (P less than 0.01) was found between the serum immunoglobulin G levels to B. gingivalis and the development of periodontitis. The antibodies to F. nucleatum (P less than 0.05), E. corrodens (P less than 0.05), and A. actinomycetemcomitans were slightly higher in patients with periodontitis than in normal subjects. There were no remarkable differences between the two groups in titers to B. intermedius, B. loescheii, and Capnocytophaga sp.

Adult↗
PubMed1984

Colonization of the subgingival area by Bacteroides gingivalis.

The initial event in colonization of the subgingival area by B. gingivalis is its attachment to host cells and Gram-positive bacteria in pre-formed plaque. The level of B. gingivalis is partly governed by products of other plaque bacteria, especially by sanguicin. Once B. gingivalis resides in its nidus and starts to proliferate, expulsion of pre-existing residents may occur, especially of attached Gram-positive bacteria, through the inhibitory action of the B. gingivalis product, hematin. The bacteriocin produced by black-pigmented Bacteroides also seems to play an important role in their establishment. Melaninogenicus possessed strong inhibitory activity against Actinomyces species. This was not completely confirmed with fresh isolates of B. gingivalis from advanced periodontitis patients. Various factors other than inhibitory substances produced by B. gingivalis and related bacteria can also affect the colonization of this species. Since the crevice area is influenced by gingival fluid, the nature of specific antibody and the other affecting components should be considered collectively with the interaction between new predominant colonizers and other pre-existing residents.

Actinomyces↗
PubMed1984

Sonographic detection of large spontaneous spleno-renal shunts and its clinical significance.

The ultrasonographic findings of large spleno-renal shunts seen in five patients with liver cirrhosis and confirmed by CT and/or portography, are described. These spleno-renal shunts were seen in the left inter- or subcostal sections as transonic, mass-like lesions located between the splenic hilum and the left kidney, and by continuous scanning, they were found to be part of a tortuous, large tubular structure. Oesophageal varices were absent or minimal in these patients, and none of them had ever bled.

Aged↗
PubMed1984

Formation of hilar collaterals or cavernous transformation after portal vein obstruction by hepatocellular carcinoma. Observations in ten patients.

A total of 155 patients with hepatocellular carcinoma were studied by celiac and superior mesenteric angiography. Complete (9 patients) or near complete (1 patient) obstruction of the portal vein and formation of hepatopetal collateral veins in the porta hepatis, or the so-called cavernous transformation of the portal vein, were seen in 10 patients. In 4 patients, the first angiogram did not show cavernous transformation, but on the follow-up angiograms cavernous transformation was present. The suggested interval between obstruction of the portal vein and formation of cavernous transformation was no more than 5 wk. The mechanism of cavernous transformation and its clinical implications are briefly discussed.

Carcinoma, Hepatocellular↗
PubMed1984

Establishment of T cell hybridomas which produce suppressor factors specific to the hen egg-white lysozyme (HEL).

The T cell hybridoma (#5104-2) which produces a suppressor factor to suppress the hen egg-white lysozyme (HEL) specific T cell proliferative response in an antigen specific manner was developed in our laboratories. Suppression by this suppressor factor require an I-J subregion matching between suppressor factor donor and donor of HEL-specific proliferative T cells. The Igh restriction between this suppressor factor donor and HEL-primed responder cell donor has not yet been observed in our experimental system. This suppressor factor has binding activity to HEL and is bound to anti-I-J antibody columns. It was also found to suppress the HEL specific delayed type hypersensitivity (DTH) responses when administered at the induction phase.

Animals↗
PubMed1984

Abnormalities of third-order suppressor T cells in old (New Zealand black x New Zealand white) F1 mice.

The suppressor T cell (Ts) function of old NZW, NZB, C57BL/6 and (NZB X NZW) F1 [B/W)F1), mice to the 2,4-dinitro-1-fluorobenzene (DNFB) hapten was studied. Intravenous administration of dinitrophenyl (DNP) coupled syngeneic lymphoid cells (which normally induce DNP specific suppression) did not result in suppression of DNFB-specific contact hypersensitivity (CS) responses in old NZB or (B/W) F1 mice. Nevertheless, when spleen cells from these old mice were injected into young mice (either (B/W)F1 or A/Sn), strong suppression of the induction phase of CS responses was observed. In addition, effector phase suppressor activity was also observed when splenic cells from tolerized old (B/W) F1 donors were transferred into young (B/W)F1 mice during the effector phase of the CS response. In both cases, the significant cells in the transfer were I-J+ T cells. Thus, the old mice retained functional Ts1 and Ts2 suppressor cells. However, the suppressive activity of the old mice could be reconstituted with spleen cells from primed young mice, suggesting that they have a defect in the Ts3 subset. This was further supported by the finding that the significant cells from the primed young mice were I-J positive and cyclophosphamide-sensitive.

Aging↗