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Biomedical subjects

K Mukai

Publications and source records attributed to K Mukai.

At least 163 records · Page 9Linked to original sources
PubMed1995

Extraskeletal osteosarcoma: a clinicopathologic study of four cases.

Four cases of extraskeletal osteosarcoma which were treated at the National Cancer Center Hospital have been reviewed. There were three males and one female. The ages of the patients were 32, 48, 48 and 59 years. Three patients had a solitary tumor located in the lower leg, thigh or postirradiated abdominal wall. The remaining patient had multiple tumors in the ipsilateral thigh and buttock. The predominant histologic subtype was osteoblastic in two cases, chondroblastic in one and malignant fibrous histiocytoma-like in one. Only one patient with a subcutaneous tumor was free of disease 16 years after a wide local excision without chemotherapy. The other three patients, two having undergone inadequate initial surgery, and one with multiple tumors, developed pulmonary metastases within 24 months of their initial surgical treatment. All of them died of the pulmonary metastases eight, 36 and 63 months after their initial treatment. Postoperative intensive chemotherapy was given to two patients. Although both had developed metastases to the lung, they received resection of the metastases combined with additional chemotherapy, surviving for more than 24 months after the occurrence of their first metastases.

Adult↗
PubMed1995

The results of three cases of unilateral pulmonary embolectomy through right thoracotomy approach for chronic pulmonary embolism.

Three patients with chronic pulmonary embolism underwent successfully unilateral pulmonary arterial thromboembolectomy. In these cases, severe degree of right heart failure and respiratory distress were the primary indications to the operation. Under normothermic partial cardiopulmonary bypass, right unilateral pulmonary thromboembolectomy were performed with beating heart. Distal counter-incision was found to be facilitated to remove thrombi completely from the distal pulmonary artery. In the results of long-term study, postoperative cardiac catheterization data encouraged us to use this technique in the surgical treatment for the selective cases of this disease. All three patients have been doing well without any sign of recurrence up to 17 years of the surgery.

Adult↗
PubMed1995

Role of Epstein-Barr virus in pleural lymphomagenesis.

Longstanding inflammation in chronic pyothorax (CP) plays a role in the development of pleural lymphoma; therefore, in 1987, the term pyothorax-associated lymphoma (PAL) was proposed. A recent study showed in the tumor cells of a limited number of patients, the presence of the Epstein-Barr virus (EBV) genome together with the expression of latent infection genes in the tumor cells of PAL. The purpose of the present study is to evaluate an association of EBV with PAL in a large number of patients. In addition, the presence of the EBV genome was examined in cases with CP without PAL. Histologic, immunohistochemical studies, and analyses by polymerase chain reaction (PCR) and in situ hybridization method for EBV were performed on 34 PAL and 16 CP collected by nationwide study. Median age of the patients in both diseases was approximately 70 years with a marked preponderance in men. Mean duration of CP in patients with CP alone and with CP complicated with PAL was 33 and 37 years, respectively. Histologically all PAL were non-Hodgkin's lymphoma, with immunoblastic type being the most common. Immunohistochemistry revealed 28 of 34 PAL to be B-cell type. Combined PCR, in situ hybridization method, and immunohistochemistry showed that the EBV genome was detected in lymphoma cells in 85% of PAL with almost constant expression of latent membrane protein-1. The EBV genome was detected by PCR in only one of 16 CP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Isolation of cDNAs encoding guanine nucleotide-binding protein beta-subunit homologues from maize (ZGB1) and Arabidopsis (AGB1).

We have isolated cDNAs from maize (ZGB1) and Arabidopsis (AGB1) encoding proteins homologous to beta subunits of guanine nucleotide-binding protein (G protein). The predicted ZGB1 and AGB1 gene products are 76% identical to each other and 41% or more identical to animal G protein beta subunits. Both predicted proteins contain seven repeats of the so-called "WD-40" motif, where WD is Trp-Asp. RNA blot analysis indicates that ZGB1 mRNA is present in the root, leaf, and tassel and that AGB1 mRNA is expressed in the root, leaf, and flower. DNA blot hybridizations indicate that maize and Arabidopsis genomes contain no other genes that are highly similar to ZGB1 and AGB1, respectively, suggesting that the newly isolated G protein beta-subunit homologues are likely to have unique functions. Furthermore, these G protein beta-subunit homologues are conserved among other plant species and may play important role(s) in plant signaling.

Amino Acid Sequence↗
PubMed1994

Nuclear immunoreaction of p53 protein in soft tissue sarcomas. A possible prognostic factor.

BACKGROUND: Tumor suppressor gene p53, located on the short arm of chromosome 17, frequently mutates in various types of cancers and plays a critical role in the multiple stages of carcinogenesis. However, there is little information about the clinicopathologic significance of alterations of the p53 gene in soft tissue sarcomas (STS). METHODS: Because it is known that nuclear accumulation of p53 protein correlates closely with the presence of mutations in the p53 gene, immunohistochemical detection of this protein was performed. A polyclonal antibody (RSP-53) raised against synthetic human p53 peptide was used to detect nuclear accumulation of the protein. Pathologic specimens of 96 patients with STS were collected from the surgical pathology files of the National Cancer Center Hospital and examined. RESULTS: Nuclear accumulation of p53 protein was detected in 31 (32.3%) patients. The percentage of patients with a positive immunoreaction was high in patients with malignant schwannoma (100%), rhabdomyosarcoma (71.4%), and synovial sarcoma (50.0%), whereas it was low in patients with liposarcoma (13.6%) and 0% in those with fibrosarcoma. It was closely associated with the histologic grade of malignancy (grade 1, 12.0%; grade 2, 30.8%; grade 3, 44.4%) and the patient's age (younger than 40 years, 46.9%; 40 years of age or older, 25.0%). Both overall and metastasis-free survival rates were significantly lower for patients with a nuclear p53 immunoreaction than for those without it. CONCLUSIONS: The nuclear p53 immunoreaction is considered a marker of tumor aggressiveness and appears to be a useful prognostic factor for STS.

Adolescent↗
PubMed1994

Serous oligocystic and ill-demarcated adenoma of the pancreas: a variant of serous cystic adenoma.

Serous cystic tumours of the pancreas are uncommon and are usually classified as microcystic adenomas (MCA). As new types of serous cystic tumours of this organ have been reported we reviewed a series of 14 lesions and from macroscopic findings two groups were distinguished: ten tumours revealed the features of MCA, while four were clearly distinct from MCA. Grossly, the latter tumours showed only few cysts which were irregularly assembled in fibrous stroma. On the cut surface, there was neither a central stellate scar nor a circumscribed tumour border, features characterizing MCA. Microscopically, the cysts were lined by cuboidal, non-mucin-producing cells. Immunocytochemical staining for cytokeratins 7, 8, 18 and 19 revealed a ductal phenotype. All non-MCA were found in the head of the pancreas and three of them occurred in men. There were no tumour recurrences or signs or malignant transformation after resection (mean follow-up, 2.9 years). These results suggest that there are serous cystic tumours distinct from MCA which may represent another variant of the category of serous cystic adenomas of the pancreas. We propose the term serous oligocystic and ill-demarcated adenoma (SOIA) for these tumours. It is possible that the recently described macrocystic sybtype of serous cystadenoma and SOIA and variants of the same tumour.

Adenoma↗
PubMed1994

Kinetic study of quenching reactions of singlet oxygen and scavenging reactions of free radicals by alpha-, beta-, gamma- and delta- tocopheramines in ethanol solution and micellar dispersion.

Quenching reactions of singlet oxygen and scavenging reactions of free radicals by alpha-, beta-, gamma- and delta-tocopheramines (Toc-amines) were investigated spectrophotometrically in ethanol and Triton X-100 micellar dispersions. The rate constants of quenching of singlet oxygen (kQ) by alpha-, beta-, gamma- and delta-Toc-amines increased as the total electron donating capacity of the methyl groups at the aromatic ring increased. A plot of logkQ vs. peak oxidation potential (Ep) was found to be linear and the slope was negative. Similar results were obtained for scavenging of a phenoxyl radical (PhO.). The results suggest that charge transfer plays an important role in these reactions. The kQ values were found to be 1.30-2.57 times as large as kQ for alpha-tocopherol (alpha-Toc). Although alpha-Toc has the highest antioxidant activity among natural tocopherols and related phenols, Toc-amines also can serve as antioxidants.

Antioxidants↗
PubMed1994

Synthesis of a phosphatidyl derivative of vitamin E and its antioxidant activity in phospholipid bilayers.

A novel phospholipid containing a chromanol structure at its polar head group was synthesized from egg yolk phosphatidylcholine and 2,5,7,8-tetramethyl-6-hydroxy-2-(hydroxyethyl)chroman by transphosphatidylation catalyzed by phospholipase D from Streptomyces lydicus. The structure of the product synthesized was shown by spectral analysis to be 1,2-diacyl-sn-glycero-3-phospho-2'-hydroxyethyl- 2',5',7',8'-tetramethyl-6'-hydroxychroman. The phosphatidylchromanol (PCh) showed antioxidant activity against radical chain oxidation of methyl linoleate in solution in a manner similar to that of d-alpha-tocopherol (alpha-Toc) and 2,2,5,7,8-pentamethyl-6-chromanol. However, PCh was less effective as a chain-breaking antioxidant than was alpha-Toc when unilamellar egg yolk phosphatidylcholine liposomes were exposed to either a water-soluble or a lipid-soluble radical initiator. It is likely that the phospholipid nature of PCh affects the location and the mobility of the chromanol moiety in the membrane bilayer resulting in a decrease in antioxidant activity. On the other hand, the antioxidant activity of PCh was little different from that of alpha-Toc in unilamellar liposomes when exposed to a lipid-soluble radical initiator in the presence of ascorbic acid. It appears that PCh in phospholipid bilayers can be regenerated by ascorbic acid in aqueous phase as can be alpha-Toc. The new phospholipid, phosphatidylchromanol, should prove useful as a chain-breaking antioxidant in phospholipid membranes.

Antioxidants↗
PubMed1994

Molecular cloning and nucleotide sequences of cDNAs encoding subunits I, II, and IX of Euglena gracilis mitochondrial complex III.

cDNA clones encoding subunits I, II, and IX of Euglena gracilis mitochondrial complex III have been isolated from a lambda gt11 cDNA expression library by immunoscreening with an antiserum against the complex of the organism. Determination of the nucleotide sequences and amino-terminal amino acid sequences of purified subunits revealed that subunits II and IX, respectively, consist of 432 and 70 amino acids as their mature forms and possess potential presequences of 42 and 30 amino acids. The amino-terminal parts of the presequences had typical structural features of the mitochondrial targeting signal. Such features were also found at the amino-terminal region of the predicted subunit I protein, which comprises 494 residues. However, the amino terminus of the purified subunit I could not be detected, possibly because of a post-translational modification. Euglena subunits I and II both showed similarities to the members of the protein family which comprises complex III core proteins, mitochondrial processing peptidases (MPP) and processing enhancing proteins (PEP). Namely, the Euglena subunit I could be assigned to core 1 protein and the subunit II to core 2 protein in the family. In contrast, the subunit IX seemed to be peculiar to Euglena complex III. At 5'-untranslated regions, the three cloned cDNAs for subunits I, II, and IX had a common poly(T)CG structure which has also been reported for other Euglena cDNAs of nuclear genes.

Amino Acid Sequence↗
PubMed1994

Increased vascular endothelial cell markers in patients with chronic renal failure on maintenance haemodialysis.

Plasma levels of the vascular endothelial cell markers, thrombomodulin (TM), plasminogen activator inhibitor-1 (PAI-1), tissue type plasminogen activator (t-PA), and von Willebrand factor (vWF) were measured in 55 patients on maintenance haemodialysis (HD). TM, PAI-1 and vWF antigen levels were significantly increased in patients before HD, but t-PA antigen was not Compared with levels before HD, t-PA and vWF antigens were significantly increased 1 h after HD and at the end of HD. TM antigen was significantly increased 1 h after HD, and plasma PAI-1 antigen was decreased at the end of HD. TM and vWF antigen levels were negatively correlated with the time (years) on HD. It is concluded that HD may cause endothelial cell damage and that the increases in plasma TM, PAI-1 and vWF levels before HD, and the decrease in the release of TM and vWF antigens from vascular endothelial cells, might be caused by vascular endothelial cell damage from long-term HD.

Adult↗
PubMed1994

Malignant progression of adenomyoepithelial adenosis of the breast.

A case of breast tumor is described, which consisted of dense and uniform proliferation of ducts and lobules composed of both epithelial and myoepithelial cells and in which multiple foci of adenocarcinoma were observed. The tumor surrounding the carcinoma foci was identified as 'adenomyoepithelial adenosis'. Adenomyoepithelial adenosis was not monoclonal by clonal analysis, but revealed a relatively high labeling index for proliferating cell nuclear antigen by immunohistochemistry. Although it was still undetermined whether adenomyoepithelial adenosis is a non-clonal nonneoplastic lesion or a biclonal neoplastic one, the lesion was shown to reveal high proliferative activity in both glandular epithelial and myoepithelial cells and was considered to be prone to progress to obvious carcinoma.

Adenocarcinoma↗
PubMed1994

Thymic carcinoma: proposal for pathological TNM and staging.

Recently, Yamakawa et al. following Masaoka's clinical staging of thymic epithelial tumors, proposed a TNM classification and staging system for thymic epithelial tumors including thymoma and thymic carcinoma. The present authors consider that division of thymomas into circumscribed types (either encapsulated or non-encapsulated but confined to within the thymus) and those invasive to adjacent organs or structures is sufficiently practical, and that a staging system is applicable to thymic carcinoma, carcinoid tumors and germ cell tumors of the anterior mediastinum, which are more malignant than thymoma. Therefore, the utility of the Yamakawa/Masaoka TNM and staging system was evaluated and a modification proposed based on experience with 16 thymic carcinomas. Although there were no cases at stage II, the survival curves obtained using the proposed modified system were more clearly separated between stages I and III or IV and between stages III and IV than the curves obtained using the Yamakawa/Masaoka system. However, the differences were not significant because of the small number of cases included. A statistically significant difference was noted between the survival curves for patients who underwent complete and incomplete surgical resection of the tumor. The utility of this proposed TNM and staging system must be evaluated by other investigators, since no cases of small cell carcinoma, lymphoepithelioma-like carcinoma, sarcomatoid carcinoma and clear cell carcinoma were included in this series, all of which are considered to have high-grade histology. An evaluation of carcinoid tumor and germ cell tumor of the anterior mediastinum must also be made.

Adult↗
PubMed1994

A review of 79 thymomas: modification of staging system and reappraisal of conventional division into invasive and non-invasive thymoma.

A clinicopathological study of surgically resected thymomas was performed using Masaoka's staging and modified Masaoka's staging systems, and the utility of these two staging systems was compared. The modification enabled adjustment for the disproportion in the number of cases between Stage I and Stage II. Analysis of survival rates, according to the tumor stage, indicated that the old classification should be reappraised, that is, division into non-invasive and invasive thymomas, although staging may contribute to the indication for postoperative radiotherapy, especially for Stage II disease. Analysis of the cases showed a wide spectrum of aggressiveness, varying from cases showing slow progression with a relatively favorable prognosis, such as the spindle cell type, to cases with rapid progression leading to tumor death in a relatively short time, such as the epithelial cell predominant and polygonal cell type. The pathological stage at the time of first surgical resection would reflect the degree of aggressiveness of thymoma in many instances. Therefore, not only staging the tumor extent but also grading of its aggressiveness are needed in order to predict the prognosis of patients with thymoma. For the latter, histology and cytopathology are helpful.

Adolescent↗
PubMed1994

Myocardial coagulation by intraoperative Nd:YAG laser ablation and its dependence on blood perfusion.

To investigate whether the efficacy of intraoperative laser ablation therapy is affected by myocardial blood perfusion, we irradiated 11 canine hearts through the epicardium with a Nd:YAG laser (10, 20, and 30 J/mm2) using air as the medium. Compared coagulated myocardial depth, width, and volume obtained in the red beating heart was compared with those in the white nonbeating heart infused with 0 degrees C saline (cardioplegic model) via the coronary artery. Histologically, the macro- and microscopical findings were very similar. At each level of energy, the width and volume of red myocardium coagulated were significantly larger than those of white myocardium (P < 0.01). At 30 J/mm2, the depth of coagulation of red myocardium was significantly larger than that of white myocardium (P < 0.01). The coagulated volume of the white myocardium was about 60% of that of the red myocardium. Nd:YAG laser energy was absorbed by blood (red color = hemoglobin), and more energy was transferred in the higher temperature myocardium. During intraoperative Nd:YAG laser ablation, the presence of blood perfusion in cardiac tissue is thought to be an important factor affecting safe irradiation.

Animals↗
PubMed1994

Development of pseudolymphoma of liver following interferon-alpha therapy for chronic hepatitis B.

A 42-year-old woman with biopsy-proven chronic hepatitis B, who had been treated with human leukocyte-derived interferon-alpha (huLe-IFN alpha) therapy for two months was found to have liver tumors on routine abdominal ultrasonography examination. She underwent laparotomy, and partial hepatectomy was performed under the clinical diagnosis of hepatocellular carcinoma. The lesions were diagnosed histologically as pseudolymphoma based on the massive infiltration of small mature lymphocytes and the presence of hyperplastic lymph follicles with germinal centers. Immunohistochemistry revealed polyclonal origin of the involved lymphocytes. The possible association between IFN alpha treatment and chronic hepatitis B with the development of pseudolymphoma is discussed.

Adult↗
PubMed1994

[A case of MELAS associated with prosopagnosia, topographical disorientation and PLED].

We report a case of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) associated with prosopagnosia, topographical disorientation, and periodic lateralized epileptiform discharge (PLED) on electroencephalography (EEG) in a 23-year-old right-handed man. The first MELAS attack occurred on March 1, 1991, while the patient was drinking. Magnetic resonance imaging (MRI) revealed a lesion of abnormal intensity in the left occipital lobe. The second attack occurred on October 1, 1991. This time, the major symptoms were visual loss of acute onset, nausea, and vomiting. EEG examination showed transient PLED. MRI revealed a new area of abnormal intensity in the right occipital lobe, lingual gyrus, fusiform gyrus and the posterior part of the parahippocampal gyrus. During the clinical course of the patient, prosopagnosia and topographical disorientation appeared. There have been few reports of MELAS associated with prosopagnosia, topographical disorientation, and PLED. However, MELAS attacks tend to occur in the cortex of the occipital lobe. We therefore believe that these neuropsychological symptoms and PLED are likely to be associated with MELAS.

Adult↗