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Biomedical subjects

T Ikari

Publications and source records attributed to T Ikari.

At least 37 records · Page 2Linked to original sources
PubMed1985

Expression in E. coli of finger-domain lacking tissue-type plasminogen activator with high fibrin affinity.

Tissue-type plasminogen activator (t-PA) has a high affinity for fibrin and induces lysis of fibrin (fibrinolysis) on the surface of fibrin without degrading circulating fibrinogen. cDNA for t-PA which lacks the 'finger-domain' (the site for fibrin affinity) was isolated from Detroit 562 cells. Analysis of the nucleotide sequence revealed a lack of the sequences which code for the finger-domain. A plasmid (pDPAT 1) containing the Escherichia coli tac promoter/operator and the cDNA sequence coding for 'finger-domain lacking t-PA' was constructed for expression in E. Coli. The polypeptide so produced was a new type of t-PA lacking finger-domain, but revealed plasminogen activator activity with the function of fibrin affinity.

Amino Acid Sequence↗
PubMed1985

Excision level and indication for contralateral neck dissection in hypopharyngeal cancer surgery.

Margins of extirpated specimens of hypopharyngeal cancer were examined histopathologically. Residual cancer nest, which is most likely due to directional preponderance of the submucosal lymph flow of the hypopharyngeal cavity, was characteristically demonstrated at the superior margin and in the submucosal layer. We propose that laryngopharyngectomy be done at the extended excision level superiorly at the base of the palatine tonsil and inferiorly at the level of the 2nd thoracic vertebra and with a safety margin of at least 2 cm. The incidence of ipsilateral and contralateral neck metastasis was also histopathologically evaluated from specimens obtained by neck dissection. Contralateral neck metastasis was histopathologically confirmed in more than 30% of the cases examined and showed a difference in incidence related to histological differentiation and T classification. We conclude that bilateral neck dissection is advisable in all cases of hypopharyngeal cancer except for patients with a well-differentiated T2 lesion.

Humans↗
PubMed1985

Surgical treatment of laryngotracheal stenosis by a trough technique.

Many methods have been tried and reported in the treatment of laryngotracheal stenosis. Among them, a trough technique seems universal at present. To date, we have tried several methods of this technique, but each method had its own demerits. We used, as a cartilagenous framework, a homograft or tracheal ring cartilages for the last four cases of laryngotracheal stenosis. These tracheal ring cartilages were resected from relatively young patients with laryngeal carcinoma. Total laryngectomy was done just below the level of the fourth tracheal ring, then the fourth tracheal ring was resected and stored in 70% alcohol. The cartilage was used after it was made certain pathologically that there was no invasion of carcinoma at the third tracheal ring level. The operative procedure of this trough technique is as follows. In the first stage, a trough is created at the stenosed region and the trough is maintained by placing a Quick Set Silicone (Q.S.S.) stent mold over it. While waiting for scar formation of the tissues surrounding the trachea, the second stage reconstruction is performed four weeks after the first. The trough is closed with hinged skin flaps on both sides, and the reserved tracheal ring cartilages are sutured every 5 mm onto the outer surface of the hinged skin flaps to make a cartilagenous framework. The neck is closed with advanced neck skin flaps. A more ideal tracheal lumen is created by this technique. Our four patients are doing well two years or more after the operation.

Adult↗
PubMed1985

Scintiscanning of mucoepidermoid tumor of the parotid gland.

99mTc-O4 and/or 67Ga-citrate scintigraphies were preoperatively applied to 13 cases of parotid mucoepidermoid tumor. The resected specimens were histopathologically subdivided into three types: well (6 cases), moderately (one case), and poorly differentiated (6 cases). As the other parotid neoplasms except adenolymphoma and oxyphilic adenoma, all poorly differentiated tumors showed focal defect image in 99mTc-O4 scintiscanning (4/4). They indicated a focal hot image in 67Ga-citrate scanning at a high rate (4/6). Otherwise, well differentiated tumors were scarcely pointed out in cold image and were usually indicated as a symmetrical image (5/6) in 99mTc-O4 scanning. None of them showed a focal hot image in 67Ga-citrate scanning, but two cases indicated diffuse increased uptake and another case showed a focal defect image. The clinical prognosis of mucoepidermoid tumors is extremely correlated to the degree of cell differentiation in our prospective study. For that reason, the therapeutic method should be carefully selected in the tumors suspected of low grade malignancy. Our study suggests that RI (99mTc-O4 and 67Ga-citrate) scintigraphy is helpful in evaluating the malignancy grade of mucoepidermoid tumors.

Adolescent↗
PubMed1983

Pathology of hepatocellular carcinoma in Japan. 232 Consecutive cases autopsied in ten years.

The pathologic findings of 232 consecutive cases of hepatocellular carcinoma (HCC) autopsied during the past ten years at Kurume, Japan, were analyzed from the point of view of global epidemiology, in relation to clinical feature, and in regard to incidence, age, sex, etiologic factors, size of liver, changes in noncancer parenchyma, gross type of tumor, extrahepatic metastases, intravascular and intraductal growths, cancer cell histology, hepatitis B surface antigen (HBsAg) in hepatocytes and cancer cells, liver cell dysplasia, and frequency and clinicopathologic characteristics of minute HCC. Furthermore, postmortem hepatic arteriography and portography were done in 152 livers for comparison with gross anatomy and celiac angiograms. It was found that: (1) epidemiologically, HCC in Japan is distinct from that in the West that it is frequently encapsulated, livers are generally small because of frequent and advanced cirrhosis and small cancer, minute HCC, is not uncommon at autopsy, cirrhosis most commonly associated is the one with thin stroma and medium size nodules, and micronodular cirrhosis is very rare despite frequent alcohol abuse; (2) HCC is increasing in incidence; (3) HBsAg is frequently found in parenchyma; (4) liver cell dysplasia is indirectly related to HBsAg with no evidence for premalignancy; (5) the lung is the most frequent site of metastasis but peritoneal dissemination is unusual; (6) intraportal tumor growth is very common and the hepatic vein is less frequently affected; (7) growth in the major bile duct is frequently associated with intraportal growth and clinically presents as obstructive jaundice; and (8) tumor is supplied solely by arteries and celiac arteriograms are closely correlated with gross pathologic findings.

Adenoma, Bile Duct↗
PubMed1983

The synthesis of human growth hormone gene.

Human growth hormone gene with 584 base pairs has been synthesized by joining with DNA ligase of chemically synthesized deoxyoligonucleotides with the chain length of 15-25. The phosphotriester polymer support synthesis was employed to obtain 80 oligonucleotides.

Base Sequence↗
PubMed1982

Hepatocellular carcinoma arising in noncirrhotic and highly cirrhotic livers: a comparative study of histopathology and frequency of hepatitis B markers.

Hepatocellular carcinoma (HCC) associated with cirrhosis and HCC developing in a noncirrhotic liver may have differing pathogeneses. To study this possibility, 425 autopsied cases of HCC were investigated. Of these, 45 livers were not cirrhotic, 50 were highly cirrhotic (liver weight less than 99 g), and the remaining 331 were cirrhotic but not so highly. The average age was significantly older in the highly cirrhotic group, suggesting a longer premalignant period of chronic liver disease. The liver weight in the noncirrhotic group was about 3.5 times that in the highly cirrhotic group. Hepatitis B surface antigen was positive in serum in only 9.3% and in liver tissue in 10% in the noncirrhotic cases, the positivity rate being much lower compared with other groups (P less than 0.005--0.01), yet antibody to HB core was positive in 90%. The antibody titers were low, however, indicating that these noncirrhotic patients had in the past had HB virus (HBV) infection with no residual chronic B hepatitis. Analysis of the grades of anaplasia of cancer tissue demonstrated an inverse correlation between the degree of fibrosis and grade of anaplasia, i.e., the more advanced the fibrosis, the less anaplastic the cancer. These data suggest that HCC arising in highly cirrhotic liver and in noncirrhotic livers have different pathogenetic backgrounds, and that HBV infection, even though transient, has a certain role in hepatocarcinogenesis. The generally held conjecture that HCC in a noncirrhotic liver is caused by nonviral carcinogens and HCC arising on the ground of cirrhosis is due to HBV seems untenable in such a simple concept.

Adult↗
PubMed1982

Esophageal reconstruction with a skin-grafted pectoralis major muscle flap.

Reconstruction of the cervical esophagus is a problem in the surgical treatment of hypopharyngeal cancer. The conventional deltopectoral skin flap and the pectoralis major myocutaneous flap both have shortcomings. We developed a new technique for the immediate reconstruction of the entire cervical esophagus that utilizes the pectoralis major muscle with skin grafted directly onto it. This is especially useful in female patients who are buxom or have thick subcutaneous adipose tissue, because the anterior chest skin is not used as the skin island and, therefore, the flap is not too bulky and cosmetic problems are minimal. The breast is left unaffected with the nipple in its normal position. We report the technical details and the results in four female patients with hypopharyngeal cancer.

Esophagus↗