Search PubMed⌕ Search

Biomedical subjects

K Fukuyama

Publications and source records attributed to K Fukuyama.

At least 127 records · Page 7Linked to original sources
PubMed1988

Skin granuloma formation in mice immunosuppressed by cyclosporine.

Granulomatous tissue reactions appear in athymic mouse skin, indicating that initiation of granuloma formation may be T-cell independent. To further evaluate the relationships between granuloma formation and T-cell function, we treated euthymic BALB/c mice with cyclosporine (Cs), a potent immunosuppressive drug, injected intramuscularly (150 mg/kg/day) 5 times a week. Hepatic granulomas were isolated from mice with schistosomiasis and transplanted into the skin of mice treated with Cs for 2 weeks. Cyclosporine injection was continued for 3 additional weeks. Blood levels of the drug increased during treatment (489 ng/ml at 2 weeks and 822 ng/ml at 5 weeks). Morphologically identical granulomas developed in both treated and untreated mice. Examination for T-cell functions showed that by the end of 2 weeks treatment, concanavalin A, phytohemagglutinin responses, and IL-2 activity were markedly depressed, and IL-2 receptor expression was not detected in either lymph nodes or spleen of the Cs-treated mice; however, after hepatic granuloma graft, T-cell functions in regional lymph nodes, but not in spleen, as well as peripheral blood eosinophilia were stimulated in Cs-treated mice. These data strongly suggest that intact T-cell activity is not essential for the initiation of granuloma formation. In addition, granuloma grafts appear to stimulate Cs-resistant T-cell activation locally, which amplifies and organizes the granulomatous response.

Animals↗
PubMed1988

Limited proteolysis of high molecular weight histidine-rich protein of rat epidermis by epidermal proteinases.

Epidermal proteinases, which may be involved in proteolysis of Mr greater than 300k histidine-rich protein in epidermis, were studied by SDS-PAGE analysis. Mr greater than 300k histidine-rich protein was extracted from granular cells of 2-day-old rats in citric acid-sucrose solution and separated from proteinases and smaller Mr proteins by Sephacryl S-300 column chromatography. The proteinase-free histidine-rich protein was stable in pH 3.5-9 at 37 degrees C for 12 h. Proteinases were partially purified from rat epidermis and inhibitor spectrum determined for each enzyme. Limited hydrolysis of Mr greater than 300k histidine-rich protein yielded a derivative of Mr 56k with cathepsin D at pH 3.5-7.5 and a serine proteinase at pH 7-9. Further proteolysis of Mr 56k protein to Mr 44k and a doublet of Mr 45k and 47k also was detected with cathepsin D at pH 3.5 and 7.5, respectively, while the serine proteinase degraded Mr 56k protein to a number of protein bands. Cathepsins B and L degraded Mr greater than 300k protein but no specific predominant product was identified. We suggest that cathepsin D and the serine proteinase may play a role in in situ processing of histidine-rich protein during cornification.

Animals↗
PubMed1988

T-cell depletion by monoclonal antibodies does not prevent granuloma formation in mice.

Effects of T-cell depletion on the formation of organized granulomas in mouse skin were investigated. Monoclonal antibodies (MoAbs) to L3T4 and Lyt-2.2 were injected into euthymic BALB/c mice in order to deplete both T-helper and T-suppressor cell populations. Four days after injection, hepatic schistosome egg granulomas were transplanted into the skin. Injection of MoAbs to L3T4 and Lyt-2.2 was repeated in the recipient mice 6 days later. At the time of transplantation, flow cytometric analysis showed that the number of T cells which were positively stained with surface markers decreased on average by 68% in both regional lymph nodes and spleen. The mitogen response of spleen cells was also markedly reduced. Despite their immunosuppressed condition, development of organized granulomas was observed in the skin of recipient mice by light and electron microscopy 3 weeks after transplantation. The findings indicate that T-cell function may not be essential for initiation of organized granuloma formation.

Animals↗
PubMed1988

Supraventricular tachycardia in a patient with Lown-Ganong-Levine syndrome associated with apical hypertrophic cardiomyopathy.

Electrophysiologic study of a 55-year-old patient with Lown-Ganong-Levine syndrome associated with apical hypertrophic cardiomyopathy is reported. The patient had a history of recurrent attacks of tachyarrhythmia and his electrocardiogram showed a short P-R interval (0.10 sec) with narrow QRS complex and left ventricular hypertrophy with giant negative T waves. His cineangiogram showed severe apical hypertrophy. An electrophysiologic study was performed. The results of programmed atrial pacing show the existence of the dual A-V nodal pathways. The A-H interval at rapid atrial pacing increased maximally by 103 msec. Atrial stimulation could depolarize parts of the atrium without altering the supraventricular tachycardia. These findings suggested that preferential rapidly conducting A-V nodal and intranodal reentry are the responsible mechanisms in this reciprocating tachycardia. We conclude that the short P-R interval was due to intranodal reentry through the dual A-V nodal pathways. To our knowledge, a case of Lown-Ganong-Levine syndrome with apical hypertrophic cardiomyopathy has not been previously described in the literature.

Cardiac Catheterization↗
PubMed1988

[A case of leiomyosarcoma of the duodenum--histologic diagnostic criteria of borderline malignancy].

A case of a leiomyosarcoma of the duodenum is reported. A 52-year-old man with a duodenal submucosal tumor underwent a pancreatico-duodenectomy. Histologically, the resected tumor revealed moderate cellular atypism and moderate pleomorphism, but revealed no mitotic figures. The histological diagnosis was leiomyoma. Nine years after operation, the tumor showed a recurrence and metastasis in the liver. Thus, the patient underwent a lobectomy of the liver. The resected liver tumor showed similar histological features seen in the primary duodenal tumor but with high mitotic activity. Histologically, the patient was diagnosed as having a metastatic leiomyosarcoma. This history suggests that a smooth muscle tumor of potential malignancy, as seen in this case, should be followed continuously, even though mitoses may not be recognized.

Diagnosis, Differential↗
PubMed1987

Crystallization and preliminary X-ray diffraction studies of tobacco necrosis virus.

Tobacco necrosis virus is a spherical plant virus consisting of 180 copies of coat protein and a single-stranded RNA. The virus has been crystallized in cubic space group P4(2)32 with a = 338 A. The locations and the orientations of the two virus particles in the unit cell have been determined on the basis of the symmetries of both the particle and the crystal. The crystal diffracts X-rays to at least 2.5 A resolution and is quite stable to X-ray beams (1 A = 0.1 nm).

Plant Viruses↗
PubMed1987

Purification and some properties of bound cysteine proteinase inhibitor from cornified cells of newborn rat epidermis.

Cysteine proteinase inhibitor exists in two forms in terminally differentiated keratinocytes. One is readily soluble in 20 mM sodium phosphate buffer but the other is bound to the plasma membrane and is poorly soluble. The cysteine proteinase inhibitor (CPI) from the membrane was extracted from cornified epidermal layers of 2-day-old rats and its properties were compared with those of soluble CPI. This CPI (bound CPI) was solubilized in alkaline 8 M urea containing 2-mercaptoethanol from the residual tissue exhaustively treated with buffered 4 M urea. CPI was separated from keratin by ammonium sulfate precipitation and purified by means of papain affinity chromatography, ion exchange column chromatography and gel filtration. Bound CPI had an Mr value of about 16,000, a pI value of 3.8 and was unstable at above 80 degrees C, while soluble CPI was of Mr 13,000 and stable at above 80 degrees C. Both CPIs were stable at 4 degrees C in the range of 3.0-9.0. Bound CPI contained half cystine and the ratio of acidic-to-basic amino acids was 3.18. Bound CPI inhibited rat liver cathepsins B, H, and L but did not inhibit the activity of noncysteine proteinases. Papain activity was inhibited by bound CPI at three sites, noncompetitively, and the Ki value was calculated to be 0.11 nM.

Animals↗
PubMed1987

Identification of 5-S-cysteinyldopa by high performance liquid chromatography in biopsies from patients with dysplastic melanocytic nevi.

The appearance of 5-[(L)-S-cysteinyl]dopa, a major product in pheomelanogenesis was examined in affected and nonaffected skins from 20 patients with clinical signs of dysplastic melanocytic nevi. Analysis by high performance liquid chromatography and electrochemical detection showed that 20 of the 35 lesions had a pathological formation of 5-[(L)-S-cysteinyl]dopa (0.04-28.86 ng/micrograms acid soluble protein). 5-[(L)-S-cysteinyl]dopa was not detected in any of the normal uninvolved skin samples analyzed.

Biopsy↗
PubMed1987

Induction of granuloma-dependent angiotensin-converting enzyme and eosinophil chemotactic factor in the skin of athymic nude mice.

Activities of angiotensin-converting enzyme (ACE), other proteinases, and eosinophil chemotactic factor (ECF-G) are known to be elevated in hepatic hypersensitivity granulomas of thymus intact (nu/+) mice after Schistosoma mansoni infection. The enzyme activities also increase, but to a lesser degree in hepatic granulomas of athymic nude (nu/nu) mice, and ECF-G is not detectable. In this study isolated hepatic granulomas from nu/+ mice were grafted into the skin of uninfected nu/nu mice, and changes in those cellular functions were determined to examine whether the newly formed granulomas by recipient nu/nu cells acquire the functional activities as well as the histological appearance of nu/+ granulomas. ACE and ECF-G rapidly disappeared from grafted sites during the first 5 days, corresponding to loss of nu/+ cells from the graft. Reduction in activities of arylsulfatases, lysozyme, and acid phosphatase also occurred, but to a lesser extent. Recovery of ACE and ECF-G activities to the levels seen in nu/+ hepatic granulomas was observed by 14 days after grafting when nu/nu cells had accumulated in the grafts and formed new granulomas. Other enzymes increased to approximately half the levels seen in grafted donor granulomas. Circulating eosinophilia also increased. The findings indicate that nu/nu cells that accumulated in the skin grafts not only morphologically mimicked nu/+ type granulomas but also demonstrated nu/+ levels of cellular function. Analysis of skin granulomas developing in nu/+ mice after grafting of nu/+ hepatic granulomas showed the similar histology and enzymatic changes, whereas the skin sites inoculated with purified schistosome eggs alone caused neither significant histological changes nor elevation of ACE activity.

Acid Phosphatase↗
PubMed1987

The highly modified membrane of cornified cells in stratified squamous epithelia: a comparison of heterogeneous deposits in keratinized and nonkeratinized epithelia.

The chemical nature of the thickened plasma membrane of cornified cells in stratified squamous epithelium was investigated in comparison with that in noncornified epithelium. Localizations of transglutaminase, molecular weight 92,000 daltons, and detection of epidermal cysteine proteinase inhibitor were effected with a monoclonal antibody and a monospecific rabbit anti-inhibitor immunoglobulin, respectively, directed to the antigens. N-(7-dimethylamino-4-methylcoumarinyl)maleimide was used to demonstrate S-S cross-linking. In all keratinizing epithelia, the enzyme and inhibitor were deposited on membranes of granular cells. S-S bonds were formed in cornification with the appearance of electron-dense material by the inner leaflet. Both enzyme and inhibitors occurred on the corneal epithelium, but S-S linkage and the thickened plasma membrane did not form even at the last stage of maturation. On the other hand, the internal vaginal epithelium in the proestrous stage without keratinization contained the enzyme, but neither inhibitor nor S-S linkage. Both antigens and S-S bonds were detected when keratinization proceeded during estrus. The staining patterns in the epithelium near the vaginal introitus were identical to those in the skin. Cuboidal and simple epithelia exhibited none of those constituents. The findings indicated that heterogeneous components contribute to modification of the plasma membrane of cornified cells, but S-S cross-linkages are associated exclusively with formation of the ultrastructurally unique membrane structure. In addition, findings suggested hormonal regulation in the chemical modification of the membrane in estrogen-sensitive internal vaginal epithelium.

Animals↗
PubMed1987

Separation and identification of cathepsins in newborn rat epidermis.

Cathepsins B, D, H, and L were identified in the extract of 2-day-old rat epidermis and separated by gel filtration from aminoendopeptidase with a Mr of 400,000 and from the low-molecular-weight cysteine proteinase inhibitor. They were further purified by ion exchange column chromatography. The final separation for cathepsins B and H was performed by gel filtration, while cathepsin D was purified by pepstatin affinity chromatography and cathepsin L by fast protein liquid chromatography (FPLC). Substrate specificity, inhibitor susceptibility, and apparent molecular weights of the separated proteinases were determined and values compared to rat liver enzymes. Apparent molecular weights for epidermal cathepsins B, H, and L were higher than those for comparable liver enzymes of adult rats. The cysteine proteinase inhibitor in epidermis was found to inhibit cathepsins B, H, and L but not cathepsin D and aminoendopeptidase of rat epidermis. This study demonstrates the presence of cathepsin L in the epidermis and describes simultaneous separation and comparison of epidermal catheptic proteinases.

Animals↗
PubMed1987

Transfer of granulomatous inflammation with nonviable preparations of schistosome granulomas in naive mice.

Hepatic granulomas of euthymic (nu/+) mice infected with Schistosoma mansoni were freeze-dried or freeze-thawed 3 times and transplanted subcutaneously into naive nu/+ and athymic (nu/nu) mice. The grafted sites, studied histologically, showed formation of organized granulomas in nu/+ mice similar to donor granulomas as observed after grafting of freshly isolated granulomas. On the other hand, in nu/nu mice, the nonviable transplants elicited small and disorganized granulomas, like hepatic granulomas in nu/nu mice with schistosomiasis, but different from fresh nu/+ transplants in nu/nu skin. The findings indicate viable cells are not required for transfer of granulomatous reactions, but T cells are needed for full expression.

Animals↗
PubMed1986

T-cell independent transfer of organized granuloma formation.

A direct role for delayed hypersensitivity in organized granuloma formation has been emphasized in the literature, but some clinical and experimental studies have suggested a more complicated relationship. In order to further evaluate T-cell function in cutaneous granulomatous inflammation, hepatic granulomas isolated from athymic mice with schistosomiasis were grafted into the skin of athymic and euthymic mice. Granulomas developed in athymic mice, as seen previously after transplantation of euthymic hepatic granulomas, indicating that granulomas develop in the skin without T-cell function. However, the granulomas in athymic mice skin were smaller and lacked eosinophils and mast cells, whereas the athymic mouse granulomas grafted in euthymic mice skin were larger, better organized, and associated with tissue eosinophilia. These findings suggest that granuloma initiation itself is T-cell independent, but that T-cell participation enhances the granulomatous reaction.

Animals↗
PubMed1986

Characterization of elastase associated with granulomatous tissue remodeling.

Elastases have been reported to be involved in various types of tissue injury. In this study we detected hydrolytic activities for [3H]-elastin and Suc-Ala-Ala-Ala-pNA (SLAPN) in hepatic granulomas which became elevated in parallel with enlargement of the granulomas and disappearance of aldehyde-fuchsin-stained filaments in the lesions of mice infected with Schistosoma mansoni. The elastase was partially purified by gel filtration followed by anion-exchange chromatography. This enzyme has a molecular weight of 20-25k and hydrolyzed denatured collagen (azocoll), Glu-Pro-Val-pNA, SLAPN, and [3H]-elastin. Optimal pH was 7-8.5. It is a serine proteinase and distinct in its inhibitor profile from murine peritoneal macrophage elastase, which has been reported by others. Digestion of elastic fibers in vessel walls and fine fibrils in newly developed granulomas by the granuloma elastase was histochemically identified with aldehyde-fuchsin stain. These results indicate that a serine proteinase functions as a major elastase in granulomatous tissue remodeling and may account for the disappearance of elastic fibers and other elements of the matrix in fully developed granulomas.

Aldehydes↗
PubMed1986

Establishment of passive hemagglutination assay (PHA) system for anti-HBc in plasma.

A sensitive and specific assay system for anti-HBc, the passive hemagglutination (PHA) method, has been established. The reactivity of PHA cells prepared by conjugating purified recombinant HBcAg-particles with fixed sheep blood cells (SRBC) was highly specific to monoclonal- and polyclonal anti-HBc IgGs. The sensitivity of PHA method was higher than that of radioimmunoassay (RIA). However, uncertainty for the positivity of anti-HBc still remained in plasma with the PHA titers lower than 2(5). A relatively high ratio (19%, 37 of 196) of anti-HBc-positive plasma, which had been confirmed to be HBsAg negative, was demonstrated in blood donors whose bloods have been considered suitable for transfusion. The hazards of anti-HBc-positive bloods and the importance of anti-HBc detection in plasma are discussed in this paper.

Antibodies, Monoclonal↗