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Biomedical subjects

K Mukai

Publications and source records attributed to K Mukai.

At least 307 records · Page 17Linked to original sources

Autoxidizability of beef heart cytochrome c1 lacking the hinge protein c1-c.

The autoxidizability of beef heart cytochrome c1 was investigated in terms of the integrity of the binding of the hinge protein to the heme subunit. Cytochrome c1 was isolated as a subcomplex consisting of the heme subunit and the hinge protein. Treatment of the cytochrome c1 subcomplex with p-chloromercuribenzoate (pCMB) under mild conditions lessened the binding strength between the two subunits. They were dissociated on polyacrylamide gel electrophoresis (PAGE) under nondenaturing conditions, but were not separated by gel filtration chromatography. The pCMB-treated subcomplex had a slight autoxidizability. This was repressed to the level of the native subcomplex, when the mercurial compound bound to the subcomplex was removed by the addition of 2-mercaptoethanol. Concomitantly, the less stable binding between the subunits was apparently reversed to the native state. After pCMB treatment of the subcomplex, the heme subunit recovered from PAGE showed marked autoxidizability, even if it was treated with 2-mercaptoethanol. Addition of cholate repressed the autoxidizability of the heme subunit after the removal of the mercurial compound. These results confirmed that the stable binding of the hinge protein to the heme subunit was essential for the nonautoxidizability of cytochrome c1 subcomplex. In addition, it was suggested that cysteinyl residues in the subcomplex must be involved to a great extent in the stable binding between the two subunits.

Animals↗

Effects of decalcification on immunoperoxidase staining.

One of the limitations of immunoperoxidase methods applied in surgical pathology is the loss of immunoreactivity during fixation and processing. In this study, the effects of decalcification on the immunoreactivity of various antigens in formalin fixed tissues were examined. The pieces of fixed tissue were placed in four different decalcifying solutions (EDTA, formic acid, nitric acid, and Plank-Rychlo solution) for various time periods and then processed routinely and embedded in paraffin. The paraffin sections of the tissues were stained with immunoperoxidase methods for immunoglobulins, hormones, or tissue/tumor-specific markers. Sections of nondecalcified tissues were used as a control. The immunohistochemical staining intensity and the number of positive cells were not reduced significantly in decalcified tissues within the usual time period of routine decalcification procedures. Many antigens survived even prolonged decalcification. The results of this study indicate that routinely decalcified tissues can be used for immunoperoxidase staining without significant loss of immunoreactivity.

Decalcification Technique↗

An immunohistochemical study of thymic epithelial tumors. II. Lymphoid component.

The cellular composition and characteristics of lymphocytes and histiocytes in nine cases of thymoma and one case of squamous cell carcinoma of the thymus were studied immunohistochemically, using a panel of monoclonal and polyclonal antibodies. Nine cases of thymoma were subclassified into seven cases of mixed type and one case each of predominantly lymphocytic type and predominantly epithelial type. Two metastatic tumors and one recurrent tumor were included. Almost all the lymphocytes in the mixed type and lymphocytic type categories, either in primary site or metastasis, were T lymphocytes which showed the immature thymic lymphocyte-phenotype of the normal thymic cortex. On the other hand, the one epithelial thymoma contained many mature T lymphocytes along with immature T cells, as in the normal thymic medulla. In thymic squamous cell carcinoma, all infiltrating T lymphocytes were mature T lymphocytes. These findings suggest that epithelial cells of thymomas have an intimate relationship with the coexisting lymphocytes and retain functional properties of the normal thymic epithelial counterpart. On the other hand, the specific function of thymic epithelial cells is no longer maintained in thymic squamous cell carcinoma.

Adult↗

Congenitally corrected transposition of the great arteries associated with the pre-excitation syndrome.

A case with congenitally corrected transposition of the great arteries associated with the pre-excitation syndrome is presented. A gated-blood-pool study and Tl-201 myocardial imaging were performed using SPECT. The tomographic gated-blood-pool images showed the shapes of the right ventricle (RV) and left ventricle (LV), i.e., anatomically LV and RV respectively, to be reversed from that of normal patients. The relationships of the great vessels and ventricles also were easily visualized. RV hypertrophy (anatomical LV) was visualized on the Tl-201 images. Phase analysis showed the earliest excitation was in the anteroseptal region near the base of the LV, which was consistent with the site of the accessory conduction pathway. The gated-blood-pool and Tl-201 tomographic studies were helpful for demonstrating the corrected transposition of the great arteries and the pre-excitation syndrome.

Female↗

Pilomatrix carcinoma: an immunohistochemical comparison with benign pilomatrixoma and other benign cutaneous lesions of pilar origin.

Two new cases of pilomatrix carcinoma are reported. They were studied immunohistochemically for the presence of high and low-molecular weight cytokeratins, beta-2-microglobulin, S-100 protein, carcinoembryonic antigen, epithelial membrane antigen, blood group isoantigens, and peanut agglutinin binding. Results of these studies were compared with those obtained in immunohistologic analysis of 13 typical pilomatrixomas, and 4 other benign lesions with hair follicle differentiation. An attempt was made to correlate antigenic expression with malignant transformation; however, there were no consistent differences between the 2 groups. It would seem that immunocytochemistry is of no assistance in differential diagnosis between benign and malignant hair matrical tumors. Hence, the pathologist must rely on morphological criteria alone to make a diagnosis of pilomatrix carcinoma.

Adult↗

The AMeX method. A simplified technique of tissue processing and paraffin embedding with improved preservation of antigens for immunostaining.

A new simplified tissue processing method for immunostaining was devised. Tissues were fixed in acetone at -20 C overnight, then cleared in methyl benzoate and xylene, consecutively, and embedded in ordinary paraffin at 58-60 C. Thin paraffin sections were deparaffinized with xylene, immersed in acetone and then phosphate buffered saline, and immunostained with various monoclonal and conventional antibodies, which have only been used on fresh-frozen or PLP-fixed frozen sections. As with PLP-fixed frozen sections, the following antigens were clearly demonstrated in the tissue sections processed with the present method: T (Leu-1, Leu-2a, Leu-3a, Leu-4, OKT3, OKT4, OKT8), B (B1, B2, Leu-14, IgM, IgD) lymphocyte surface markers and other antigens (Leu-7, OKT6, OKT9, OKM1, OKI1, J5, Ki-1, Ki-67, TdT, oncogene Ha-ras P21). Sections prepared by the present method demonstrated much better histologic and cytologic preservation than possible in frozen sections.

Acetone↗

Radical surgical cure of Wolff-Parkinson-White syndrome: the Kanazawa experience.

Between 1973 and 1983, we operated on 160 patients with Wolff-Parkinson-White syndrome at Kanazawa University Hospital; 126 had Wolff-Parkinson-White syndrome alone, and 34 had combined cardiac diseases. Of the 160 patients, 140 were completely cured; postoperatively, they had no delta wave on electrocardiograms and no tachycardia attacks. In 11 patients, the delta wave reappeared an average of 56 days after operation. They, and three other patients with concealed Wolff-Parkinson-White syndrome, experienced several postoperative episodes of tachycardia. However, in 12 of the 14 patients with postoperative tachycardia attacks, these disappeared completely in the course of a long follow-up period and these patients are also considered to be cured symptomatically. In the two remaining patients, the tachycardia attacks persisted. Of the 126 patients with Wolff-Parkinson-White syndrome alone, none died as a direct result of the operation. Patients with combined cardiac diseases other than cardiomyopathy, mild Ebstein's anomaly, or venous abnormality were treated in one operation. Six of the 34 patients with combined cardiac diseases died. In none of the 160 patients was the His bundle intentionally interrupted as an alternative method of interrupting the accessory conduction pathway. Our study showed that life-threatening arrhythmias occur more often than expected in patients with Wolff-Parkinson-White syndrome and the tolerance for tachycardia attacks differs from patient to patient. Because the surgical treatment of Wolff-Parkinson-White syndrome is safe and reliable, as indicated in this report, the radical correction of this disease should be considered in carefully evaluated patients.

Adolescent↗

Dissociation of bovine cytochrome c1 subcomplex and the status of cysteine residues in the subunits.

Purified bovine heart two-band cytochrome c1 subcomplex was dissociated by treatment with p-chloromercuribenzoic acid (pCMB) into its heme subunit and a colorless subunit called hinge protein, which is essential for the formation of cytochrome c1-c complex. The subcomplex was found by titration to react with 4 mol of pCMB per mol of cytochrome c1. The contents of mercury of the dissociated heme subunit and the hinge protein were 3 and 1 mol per mol of polypeptide, respectively. These results, together with the sequence analysis, indicated that the three cysteine residues in cytochrome c1 heme subunit not involved in heme-binding existed in free thiol form. One of the five cysteine residues in the hinge protein was in free form and four in two disulfide bonds. The dissociated hinge protein was digested with staphylococcal protease and the cysteine-containing peptides were separated by reversed-phase high-performance liquid chromatography (HPLC). The content of mercury and the result of performic acid oxidation of cystine peptides revealed that Cys-30 existed in free thiol form and two disulfide bridges were formed between Cys-24 and Cys-68 and between Cys-40 and Cys-54. The conformation of the hinge protein was predicted to be composed largely of either two-alpha-helical or four-alpha-helical conformation with the amino (N)-terminal 20 residues being in a random structure.

Amino Acid Sequence↗

[Adenocarcinoma of the esophagus (early stage) concomitant with lung cancer--a case report].

A case of early esophageal cancer, 2.5 cm in length, located just above the esophagogastric junction is presented. This cancer seemed to originate from the fundic gland of the esophagus, because it consisted of the submucosal invasion of well-differentiated adenocarcinoma which was almost completely covered with the squamous cell mucosa of the esophagus. This patient was referred to our clinic because of lower to be a small-cell carcinoma of the lung extending to the mediastinum. He died of the lung cancer one year after operation.

Adenocarcinoma↗

Establishment and characterization of a new human cultured cell line from a prolactin-secreting pituitary adenoma.

A new human cell line was established from a prolactin (PRL) secreting pituitary adenoma. This cell line, designated as HPA, initially produced and secreted PRL, but the ability was decreased with increasing passage number. After about 30 passages in vitro, these cells had a short doubling time (14 h) and a low plating efficiency (9%). When a minimum of 10(5) cells was injected per mouse, virtually all athymic nude mice developed a slow growing, nonmetastasizing tumor at the injection site about 30 days after injection. PRL production by the HPA cells after Day 150 was demonstrated by immunocytochemistry as well as radioimmunoassay. In addition, cimetidine (10(-4) M) had a significant stimulatory effect on PRL secretion by 4-day-cultured HPA cells. When the HPA cells were incubated in the presence of 5.0 and 10.0 nM bromocriptine, the proliferation rate was inhibited to 53.4 and 25.1% of untreated controls, respectively. On the other hand, the same concentrations of bromocriptine did not affect the proliferation rate of YK cells derived from human immature teratoma of the ovary. In addition, bromocriptine inhibited significantly the growth rate of xenotransplanted HPA but not YK cells. These results suggest that bromocriptine inhibits specifically the proliferation of HPA cells.

Adenoma↗

[Clinical and immunological study on the high incidence of malignant neoplasms in patients with chronic renal failure].

With the advancement of dialysis techniques, rehabilitation and high morbidity are becoming serious problems for patients with chronic renal failure. The authors, with the purpose of investigating the carcinogenic state of such patients, studied the incidence of malignant neoplasms and their immunity both clinically and fundamentally. Out of 499 patients with chronic renal failure, malignant neoplasms were found in 17 cases (3.40%), which is obviously a high rate with a statistically significant difference from that of the ordinary healthy population. In the fundamental immunity study, OKM1+ cells of the patients were significantly lower than those of healthy people, and a decrease in NK and K cells was inferred. Incidentally, the lymphocytes of patients strongly inhibited the mitogen response of healthy subjects. This decline in cellular immunity is considered to be closely related to the carcinogenicity of patients with chronic renal failure.

Adult↗

24-hour mean pulse. Simple predictor of doxorubicin-induced cardiac damage.

Nineteen adult patients with cancer received six to 10 monthly treatments of doxorubicin and cisplatin. Recumbent pulse was measured for 24 to 30 hours before each treatment. Treatment was stopped for disease progression or when a total doxorubicin dose of 550 mg/m2 was reached. Rising serial 24-hour pulse averages predicted congestive heart failure reliably. No patient had congestive heart failure during therapy, but three patients had congestive heart failure two to four months after receiving 540, 525, and 530 mg/m2 of doxorubicin. In these, two to six months before completion of therapy, the 24-hour rhythm-qualified mean (mesor) of pulse showed a positive slope by linear regression analysis (p less than 0.05) that was apparent at cumulative doxorubicin doses of 300, 420, and 240 mg/m2. All 19 patients received similar total doses of doxorubicin and were followed to death or 12 months after the last doxorubicin dose. In addition, a progressive rise in the 24-hour mean pulse coincided with histologically documented doxorubicin-induced lethal congestive heart failure in Wistar-Kyoto rats of both sexes.

Adult↗