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Biomedical subjects

T Sako

Publications and source records attributed to T Sako.

123 records · Page 7Linked to original sources
PubMed1980

Coordinate expression of Escherichia coli dnaA and dnaN genes.

The defects of temperature-sensitive dnaA and dnaN mutants of Escherichia coli are complemented by a recombinant lambda phage, which carries the bacterial DNA segment composed of two EcoRI segments of 1.0 and 3.3 kilobases. Derivatives of the phage, which have an insertion segment of Tn3 in the dnaA gene, are much less active in expressing the dnaN gene function than the parent phage. The dnaN gene activity was determined as the efficiency of superinfecting phage to suppress loss of the viability of lambda lysogenic dnaN59 cells at the non-permissive temperature. Deletions that include the end of the dnaA gene distal to the dnaN gene also reduce the expression of the dnaN gene function. Deletion and insertion in the dnaN gene do not affect the expression of the dnaA gene function. The expression of the dnaN gene function by the dnaA- dnaN+ phages remains weak upon simultaneous infection with dnaA+ dnaN- phages. Thus the insertion and deletion of the dnaA gene influence in cis the expresion of the dnaN gene. We propose that the dnaA and dnaN genes constitute an operon, where the former is upstream to the latter.

Bacteriophage lambda↗
PubMed1979

A clinical study of tuberculous colitis.

During the last 8 years, the diagnosis of tuberculous colitis has been made radiologically in 22 cases. Twelve were confirmed by histological or bacteriological evidences. The X-ray findings are classified into three types as follows: Type A, showing an extensive scarred area in the ileocecum and ascending colon. Type B, showing annular stricture in the ascending colon and dilatation of its oral side. Type C, showing pouchformation (pseudo-diverticulum) and deformity in the cecum. We emphasize that histological examination and culture of the biopsy specimens by endoscopy were useful for the diagnosis of tuberculous colitis. Furthermore, radiologic changes of the colon by administration of antituberculous drugs were observed.

Adult↗
PubMedDate not supplied

Organization and transcription of the dnaA and dnaN genes of Escherichia coli.

The locations of the linked dnaA and dnaN genes of Escherichia coli in a specialized transducing lambda phage genome have been determined by electron microscopic heteroduplex analysis, using phages with deletions or insertions in the dnaA or dnaN gene. The transcription initiation sites for the dna genes were also localized by electron microscopic analysis of DNA-RBA heteroduplex molecules formed between the E. coli DNA fragment of the phage genome and the in vitro transcription products of the fragment. The dnaN gene was found to be transcribed in the same direction as the dnaA gene, and predominantly from the promoter of the dnaA gene.

Bacterial Proteins↗
PubMedDate not supplied

Neuroendocrine carcinoma in the nasal cavity of ten dogs.

Neuroendocrine (NE) carcinoma was diagnosed in 10 dogs. In six cases examined by cephalometric radiography and computerized tomography, a large mass was seen to fill the nasal cavity. Histopathologically, sheets, nests or ribbons of neoplastic cells were separated by delicate or thick fibrovascular stroma. The neoplastic cells were round, oval, or spindle-shaped; cytoplasmic granules and hyperchromatic nuclei with prominent nucleoli were present. Neoplastic cells were invariably immunohistochemically positive for cytokeratin (CK) AE1/AE3, neuron-specific enolase, chromogranin A and vasoactive intestinal polypeptide. Eight dogs were positive for S100 protein, seven for synaptophysin, five for protein gene product 9.5, two for somatostatin, and one for Leu-7. Immunolabelling gave negative results for CK 8, CK 19, calcitonin, calcitonin gene-related polypeptide, neurofilaments, serotonin, gastrin and glial fibrillary acidic protein. Ultrastructurally, the neoplastic cells contained a large number of round, membrane-bounded, densely-cored granules corresponding to neurosecretory granules. These observations were consistent with the neuroendocrine nature of the carcinomas.

Animals↗
PubMedDate not supplied

Serum levels of interleukin-12 in patients with gastrointestinal cancer.

Interleukin 12(IL-12) is a heterodimeric cytokine that has potent anti-tumor and anti-metastatic activities. Although clinical trials of recombinant human IL-12 have begun in patients with several advanced malignancies, very few studies have investigated the preoperative serum levels of IL-12 in patients with gastric or colorectal cancer. The purpose of the present study was to investigate the relationships between the preoperative serum levels of IL-12 and clinicopathological factors in patients with gastric or colorectal cancer. Blood was obtained before surgery from 14 patients with gastric cancer and 15 patients with colorectal cancer. Serum levels of IL-12 was assessed using the quantitative sandwich enzyme immunoassay technique. Although not statistically significantly, low serum levels of IL-12 tended to be associated with gastric cancer patients who were node-positive, CEA positive, had tumors that penetrated the serosa, had tumors greater than 5 cm in diameter, were more than 60 years-old, or were more advanced than stage IIIA(TNM) or stage IIIa(Japanese Research Society for Gastric Cancer). Patients with colorectal cancer who were node-positive, had tumors that penetrated the serosa, were more than 60 years-old, or were more advanced than stage III(TNM), stage IIIa(Japanese Society for Cancer of the Colon and Rectum) and Dukes' C also tended to have low serum IL-12 levels. These results suggest that low serum levels of IL-12 may be observed in more advanced gastric and colorectal cancer patients. Thus, patients with low serum levels of IL-12 in gastric or colorectal cancer may require additional immunochemotherapy after surgery.

Female↗
PubMedDate not supplied

Relationship between plasma levels of vascular endothelial growth factor and serum levels of interleukin-12 in patients with colorectal cancer.

BACKGROUND: Vascular endothelial growth factor (VEGF) is thought to be the most potent angiogenic factor in the numerous malignant tumors and a prognostic indicator for cancer patients. Interleukin 12 (IL-12) is a heterodimeric cytokine that has potent anti-tumor and anti-metastatic activities. Recently, it has been suggested that IL-12 regulates VEGF in a murine breast cancer model. MATERIALS AND METHODS: Blood from 26 patients with colorectal cancer was obtained prior to surgery. Plasma levels of VEGF and serum levels of IL-12 were assessed using the quantitative sandwich enzyme immunoassay technique. We investigated the preoperative relationships between plasma levels of VEGF, serum levels of IL-12 and clinicopathological factors in patients with colorectal cancer. RESULTS: Although not statistically significantly, high plasma levels of VEGF and low serum levels of IL-12 tended to occur with more advanced colorectal cancer. Plasma levels of VEGF in patients who had circumferential involvement of the tumor greater than 1/2 were only significantly increased. The preoperative relationship between plasma levels of VEGF and serum levels of IL-12 tended to be negatively correlated. CONCLUSION: These results suggest that high plasma levels of IL-12 or low serum levels of IL-12 may be observed in more advanced colorectal cancer patients. Thus, these patients may require additional immunochemotherapy after surgery. IL-12 may regulate VEGF in the patients diagnosed with colorectal cancer.

Adult↗
PubMedDate not supplied

Spontaneous abdominal aortic dissection: case report and review.

An abdominal aortic dissection was incidentally imaged by contrast infusion computed tomography (CT) in a patient with an abdominal liposarcoma. Previously reported cases of spontaneous abdominal aortic dissection with radiographs are reviewed.

Aortic Dissection↗