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Biomedical subjects

K Mukai

Publications and source records attributed to K Mukai.

At least 325 records · Page 18Linked to original sources
PubMed1984

Electron spin resonance and electron nuclear double resonance studies of cation radicals derived from tocopherol model compounds.

Electron spin resonance (ESR) and electron nuclear double resonance (ENDOR) measurements were performed for the cation radicals obtained from the model compounds of alpha-, beta-, gamma- and delta-tocopherol (vitamin E) by oxidizing the tocopherol precursors in an AlCl3-CH2Cl2 solution. The proton hyperfine coupling constants and g-values were precisely determined. The ENDOR spectra of the cation radicals of alpha-, beta-, gamma- and delta-tocopherol models in CH2Cl2 at -100 degrees C clearly show 10, 6, 6 and 12 different proton hyperfine couplings, respectively. By varying the temperature, the ESR spectra of the alpha- and delta-tocopherol model cations exhibit line-width alternation phenomena characteristic of the hindered rotation of the OH group. However, neither the beta- nor the gamma-tocopherol model cation radical ESR spectra show any sign of an alternating line-width effect. These results are interpreted by assuming that the beta- and gamma- tocopherol model cations are stabilized in the trans and cis conformations, respectively. On the other hand, both the alpha- and delta-tocopherol model cations exist as cis and trans isomers.

Chemical Phenomena↗
PubMed1984

Endocrine pancreas in cystic fibrosis: an immunohistochemical study.

The pancreases of 17 patients who had cystic fibrosis with and without diabetes mellitus were evaluated at autopsy by routine staining and immunohistochemical methods for insulin, glucagon, somatostatin, and pancreatic polypeptide. Qualitative assessment of the number of islets of Langerhans and the degrees of exocrine pancreatic atrophy, fibrosis, and fat replacement was made for each pancreas. Quantitative assessment of islet composition was performed in 15 of the 17 based on the immunochemical reactivity of each cell type. Nondiabetic patients with cystic fibrosis in the latter part of the first decade of life have classic fibrocystic changes of the pancreas, with some persisting exocrine tissue, islets that appear normal, and prominent nesidioblastosis. The latter process may protect these patients from glucose intolerance. Young adult diabetic patients with cystic fibrosis have total loss of exocrine pancreas with fat replacement, lack of nesidioblastosis, a qualitative decrease in the number of islets, fibrosis of and amyloid deposits in islets, decreased numbers of insulin-containing cells in each islet, and atrophy of islet cells, probably resulting from progressive ischemia. Although the potential exists for an increasing incidence of diabetes mellitus in patients with cystic fibrosis as their life spans increase, individual variation occurs in this disease.

Adult↗
PubMed1984

Characterization of an established cell line from human immature teratoma of the ovary and effects of retinoic acid on cell proliferation.

A human immature teratoma cell line was established from tumor tissue of the ovary. The cell line, designated YK , synthesized and secreted alpha-fetoprotein, but there was a gradual decrease in the synthesis of this protein during serial passage. The doubling time at passage 43 was about 20.3 hr, and the plating efficiency was 30 to 40%. Tumorigenicity of the cell line in athymic nude mice was 100% even when 10(4) cells were inoculated s.c. When the cell line was cultivated for 5 days in the presence of 80 microM retinoic acid, proliferation was completely inhibited, while alpha-fetoprotein secretion into the medium was increased. Specific lactate dehydrogenase activity in the tumor grown in nude mice as well as in the cultured cells was 8 times higher than that in the original tumor. The activity of alpha-hydroxybutyrate dehydrogenase in the original tumor was similar to that in the tumor grown in nude mice, while the activity in the cultured cells was about 2.5 times higher than those in both original tumor and the tumor grown in nude mice. The original tumor had all five ordinary bands of lactate dehydrogenase isoenzymes. In contrast, both the cultured cells and the tumor grown in nude mice had a characteristic band which was considered to have similar electrophoretic mobility as testicular lactate dehydrogenase X isoenzyme in humans.

Animals↗
PubMed1984

Systemic lymphoproliferative disorder with morphologic features of Castleman's disease. Immunoperoxidase study of cytoplasmic immunoglobulins.

Lymph node biopsy specimens from nine patients with a systemic lymphoproliferative disorder morphologically resembling Castleman's disease were studied for the presence of cytoplasmic immunoglobulins. After trypsinization of tissue sections, the avidin-biotin-peroxidase method was used to stain for IgG, IgA, and IgM heavy chains and kappa and lambda light chains. All cases showed polyclonal proliferation of plasma cells. The predominant immunoglobulin class observed was IgG. The IgM-containing cells tended to be localized concentrically around germinal centers. No notable changes were seen in multiple biopsy specimens from five patients. Polyclonal staining was also observed in lymph nodes obtained at autopsy from a patient who died of a disseminated atypical immunoproliferative process. The polyclonal staining pattern in these cases confirms the reactive nature of this systemic lymphoproliferative disorder.

Adult↗
PubMed1984

Solid ovarian teratomas: an immunocytochemical study of thirteen cases with clinicopathologic correlation.

The modified histologic grading system for solid ovarian teratomas used by Norris et al. which attempts to quantitate the presence and amount of primitive neuroepithelium, is in our opinion, an improvement over the original system. In our experience, however, some difficulties in its application remain. Grade 0 and 1 tumors were easily identified, but there was considerable confusion in attempting to separate grade 2 tumors in which neuroepithelium does not exceed three low-power microscopic fields in any one slide from grade 3 tumors in which neuroepithelium occupies four or more low-power fields. The difficulty arose in deciding whether the amount of neuroepithelium required to qualify as "occupying" a low-power field was sufficient if a single focus was present, or if the entire microscopic field should contain neuroepithelium. In the former case, four small foci of primitive neural tissue present in separate locations in a single slide would qualify for diagnosis as a grade 3 tumor, whereas if the same amount of tissue was found close together (i.e., within the space of a single low-power field), it might be read as a grade 1 tumor. This system is also potentially dependent on a fortuitous sampling technique, since a grade 3 tumor could be diagnosed as a lesser grade if a particular section in which four low-power fields containing neuroepithelium is not chosen for microscopic examination. One of the most important steps in attempting to resolve some of the conflicts surrounding the correlation of tumor histology with natural history in solid ovarian teratomas is to assure adequate sampling of the tumor. Norris et al. suggest that one block per centimeter of the maximum diameter of the tumor should be evaluated, others stress the importance of directing sampling toward areas of hemorrhage or necrosis, in an attempt to disclose immature foci. Because of these potential problems, we suggest as a possible alternative using the estimated percentage of neuroepithelial tissue present in all the tissue examined microscopically as a basis for determining the histologic grade. In our small series, it appears that tumors without neuroepithelium would be equivalent to a grade 0, tumors with up to 10 percent neuroepithelium would be graded 1, those with approximately one-third neuroepithelium would be grade 2 tumors and those with approximately one-half or greater of their tissue as a neuroepithelium would be grade 3 tumors.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1983

Reaction of biological phenolic antioxidants with superoxide generated by cytochrome P-450 model system.

Scavenging of a superoxide and simultaneous formation of free radicals with phenolic antioxidants were investigated with cobalt and iron tetraphenylporphyrin-thiolate complexes as models of P-450 enzymes. The kinetics of decay of the superoxide and development of free radical ESR signal intensities were studied. Based on a molecular orbital calculation of the hyperfine splitting, the radical species generated were confirmed to be those of phenoxyl radicals. The biological implication of superoxide, including active oxygen forms, for the reaction was discussed.

Antioxidants↗
PubMed1983

Pituitary adenomas. Immunocytochemical study of 150 tumors with clinicopathologic correlation.

Retrospective immunocytochemical study of prolactin, growth hormone, ACTH, TSH and gonadotropins was performed on 150 pituitary adenomas from 142 patients and the results were correlated with clinical manifestations. There were 60 prolactin-positive tumors, 13 growth hormone-positive tumors, nine ACTH-positive tumors and seven gonadotropin-positive tumors. Seven tumors showed positivity for both prolactin and growth hormone, one tumor was positive for prolactin and ACTH and another was positive for prolactin and TSH. Fifty-two tumors were negative for all the hormones. In the hormone secreting tumors, the results of immunocytochemical study correlated very well with clinical manifestations, while most of the hormone-negative tumors were nonfunctioning clinically. This study demonstrates the reliability of the immunocytochemical method in clinicopathologic study of pituitary adenomas.

Adenoma↗
PubMed1983

Primary carcinoid tumor of the kidney: a light and electron microscopic, and immunohistochemical study.

We report a case of primary carcinoid of the kidney. The neoplasm had a trabecular growth pattern and was argyrophil positive and argentaffin negative. An extensive battery of immunohistochemical stains was negative for specific peptide products and keratin. Electron microscopy disclosed numerous cytoplasmic membrane-bound electron-dense core secretory granules and masses of intermediate microfilaments. A review of the pertinent medical literature revealed 5 previously reported cases.

Adult↗
PubMed1983

Differential staining pattern of lysozyme in palisading granulomas: an immunoperoxidase study.

Biopsies from palisading granulomas of granuloma annulare, necrobiosis lipoidica, and rheumatoid nodules were examined for the presence of lysozyme (muramidase). This enzyme was identified in paraffin-embedded tissues using a primary antibody to lysozyme and the peroxidase-antiperoxidase technic. Some inflammatory cells in the infiltrate of granuloma annulare stained abundantly for lysozyme, whereas those of necrobiosis lipoidica and rheumatoid nodule stained minimally and negatively, respectively. This pattern of staining may be of diagnostic value and suggests that the histiocytoid cells constituting the infiltrate of granuloma annulare are in some way different from the similar-appearing cells of necrobiosis lipoidica and rheumatoid nodule.

Granuloma↗
PubMed1983

Glial differentiation in medulloblastomas. Histogenetic insight, glial reaction, or invasion of brain?

The histogenesis of the medulloblastoma has been controversial since the original description of the tumor over 50 years ago. Recent debates have focused upon whether the tumor differentiates along glial or neuronal lines. In order to address this question, we reviewed the clinical histories, histopathologic features, and immunocytochemical staining for glial fibrillary acidic protein (GFAP) in 20 patients seen at our hospital from 1970 to 1980. Primary tumors, local recurrences, and metastatic tumors were all included. Five of the 20 primary cerebellar tumors contained weakly GFAP-positive foci. Local recurrences occurred after treatment in seven patients and extracranial metastases in two, all of which were GFAP-negative. Interpretation of GFAP positivity was problematic. In most instances it occurred in areas where astrocytes might predictably be found: at the interface of tumor and adjacent brain and around blood vessels. Only rare single positive cells were identified in the midst of tumor nodules where cytologic distinction between neoplastic and reactive astrocytic cells was difficult. We conclude that GFAP positivity may not be intrinsic to medulloblastomas and must be interpreted with a degree of skepticism.

Adolescent↗
PubMed1983

A pituitary parasellar tumor with extracranial metastases and high, partially suppressible levels of adrenocorticotropin and related peptides.

We report the history, laboratory findings, and studies performed on a 27-yr-old patient with a metastatic parasellar adenoma of the pituitary and Cushing's syndrome. She developed intense hyperpigmentation and extraordinarily high ACTH levels after bilateral adrenalectomy in 1974. With the exception of marked hyperpigmentation, she did well on glucocorticoid replacement therapy until August 1979, when multiple hepatic nodules were observed during a cholecystectomy. Histological studies and immunoperoxidase staining indicated that these lesions were pituitary tumor metastases. What were presumed to be metastatic lesions also developed in lungs and bone. This combination of liver, bone, and lung metastases from primary pituitary tumors has not previously been reported. Immunoreactive plasma ACTH concentrations were as high as 230,000 pg/ml. Similarly, high levels of plasma immunoreactive beta MSH and immunoreactive beta-endorphin were found. High doses of glucocorticoids reduced the concentration of ACTH to one seventh to one tenth the basal level. The sensitivity of plasma ACTH to exogenous steroid administration strongly suggests that an intact intracellular mechanism for negative feedback control of ACTH secretion persisted within the tumor cells. The rapid rise in ACTH and related peptides and the development of metastases after adrenalectomy suggest that both the secretory capacity and the oncogenic potential of the parasellar tumor were chronically inhibited by glucocorticoid hormones.

Adenoma↗
PubMed1983

Functional pathology of pancreatic islets: immunocytochemical exploration.

Immunocytochemical methods have been used extensively in morphologic studies of pancreatic islets and have contributed a great deal to understanding morphofunctional relationships in various pathologic conditions. Many hitherto unknown changes in the cellular composition of islet tissue have been discovered using these methods. Appropriate and inappropriate secretory products have been identified in the pancreatic endocrine tumors. It is expected that immunocytochemical methods, together with electron microscopy, will provide additional important information about the pathophysiology of the pancreatic islets.

Adenoma, Islet Cell↗
PubMed1982

Cystic mesothelioma of the peritoneum: a report of five cases and review of the literature.

Five cases of the recently characterized cystic mesothelioma of the peritoneum are presented. The patients, all women, ranged in age from 23-50, and were seen with large, solitary or multiple, multicystic masses involving the abdominal and pelvic peritoneum. Histologically, they consisted of interconnecting cystic cavities lined by a single layer of flattened to cuboidal cells with variable nuclear atypia. These cells in one case showed ultrastructural features consistent with mesothelial origin. In follow-up periods ranging from 1-13 years, two patients have had recurrence of disease, but all patients are still alive. When these cases are combined with the ten previously reported, the recurrence rate in patients followed for two years or more is 50% (four of eight). This lesion may represent a clinically "borderline" variant between the better known benign (adenomatoid tumor) and malignant mesotheliomas of the peritoneum.

Adult↗
PubMed1982

Studies of hCG binding and endocytosis in rat ovary by ultrastructural immunocytochemistry.

Localization of hCG binding sites and the process of endocytosis in pseudopregnant rat ovaries were investigated by indirect electron-microscopic immunocytochemistry. Immature female rats were treated with pregnant-mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) to induce ovarian luteinization. Eight days after priming with PMSG-hCG and 1-6 h before sacrifice the animals were given another injection of hCG to bind the receptors. Receptor sites to hCG localized by reaction product were present in most luteal cells, but not in primary follicular cells. The receptor sites were distributed on luteal cell surfaces facing interstitial spaces. Endocytotic pits containing hCG binding sites were rarely seen 1 h after hCG injection. At 2h, hCG and presumably its receptor were taken up within endocytotic vesicles with the evidence of reaction product coated on the vesicle wall. With time, fusion of endocytotic vesicles with lysosome occurred and the reaction product appeared in phagolysosomes. The reaction product was localized on phagolysosomal inner surface or in free granular form. These findings suggest that hCG and its receptors were internalized through endocytotic pits and endocytotic vesicles and delivered to lysosomes probably for degradation. An additional experiment for localization of acid phosphatase was also performed to delineate the lysosomes and phagolysosomes.

Animals↗