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Biomedical subjects

T Kasuga

Publications and source records attributed to T Kasuga.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Study of complications after endoscopic sclerotherapy for esophageal varices--particularly 2 cases that changed portal circulation after sclerotherapy].

In 116 patients with esophageal varix due to liver cirrhosis who received the endoscopic sclerotherapy, the following complications were observed after the sclerotherapy: 38 ulcer formation; 19 chest pain; 16 hypotension; 15 fever; 12 pleural effusion; 6 esophageal stenosis and so on. Furthermore, two cases with marked changes of portal circulation were experienced after the sclerotherapy. The first case had severe bleeding out of duodenal varix four months after the sclerotherapy and died because of massive bleeding. The second case had hepatic encephalopathy six months after the sclerotherapy. In both cases, angiography revealed the development of collateral veins after the sclerotherapy. Because the abrupt intercept of the esophageal varix by the successful sclerotherapy causes the increase of the other collateral blood flow, the changes of portal circulation must be watched carefully afterward.

Adult↗
PubMed1988

Increasing incidence and changing histopathology of primary lung cancer in Japan. A review of 282 autopsied cases.

A total of 282 autopsied cases of primary carcinoma of the lung were reviewed from 1950 to 1983 to determine the incidence of histologic types, sex and age distribution, and to compare the trends between Japan and the United States. There were 75 cases in Group A (1950-1964), 89 in Group B (1965-1974) and 118 in Group C (1975-1983). The overall incidence, 282 cases per 8546 autopsies, was 3.3%; the male-to-female sex ratio was 2.4:1, and the mean age was 62 +/- 11 years. Increases in incidence in men, women, and the total from Group A to C were all statistically significant (P less than 0.05). A predominance of adenocarcinoma over squamous cell carcinoma in all cases was apparent in all the groups, but the data showed a trend toward a reduction in the proportion of adenocarcinoma and increases in the proportion of squamous cell carcinoma and small cell carcinoma. In contrast, an increasing incidence of adenocarcinoma was reported in the USA.

Age Factors↗
PubMed1988

Specific incorporation of 4-S-cysteinylphenol into human melanoma cells.

The incorporation of 4-S-cysteinylphenol (4-S-CP), a tyrosine analog, into malignant melanoma cells was evaluated. 4-S-CP was specifically incorporated into the melanotic melanoma cells (HMV-II), which have activity for melanin synthesis, but was scarcely incorporated into HeLA S3 or HMV-I cells, which have no activity for melanin synthesis. Electron microscopic autoradiography revealed that the intracellular localization of 4-S-CP was closely correlated with melanogenesis and that 4-S-CP served as an initial substrate for tyrosinase and was utilized in melanin synthesis. On the basis of these findings we hypothesize that tyrosinase is required for intracellular incorporation of 4-S-CP. This specific incorporation of 4-S-CP into melanoma cells should be useful in the development of an effective procedure for chemotherapy of malignant melanomas and in analysis of melanin synthesis.

Autoradiography↗
PubMed1987

Mechanism of selective toxicity of 4-S-cysteinylphenol and 4-S-cysteaminylphenol to melanocytes.

Our previous studies showed that 4-S-cysteinylphenol (4-S-CP) and 4-S-cysteaminylphenol (4-S-CAP) inhibit the growth of malignant melanoma and cause depigmentation of black skin. In this study we examined kinetic constants of CP and CAP as substrates for tyrosinases and their properties as sulphydryl scavengers. 4-S-CP and 4-S-CAP were found to be much better substrates for mushroom tyrosinase than L-tyrosine while their 2-S isomers were not the substrates. 4-S-CP and 4-S-CAP were also good substrates for mammalian tyrosinase. Upon tyrosinase oxidation the two phenols conjugated with cysteine to form the cysteinyl derivatives of the corresponding catechols via o-quinone forms. The tyrosinase oxidation product of 4-S-CP had a poor ability to conjugate with alcohol dehydrogenase, a sulphydryl enzyme, while that of 4-S-CAP had a much higher ability. These results suggest that in melanocytes these phenols are oxidised by tyrosinase to the corresponding o-quinone forms, some of which conjugate with sulphydryl enzymes through cysteine residues, thus exerting cytotoxic effects.

Catechols↗
PubMed1987

Angiosarcoma of the scalp: report of two cases with fatal pulmonary complications and a review of Japanese autopsy registry data.

Two cases of angiosarcoma of the scalp were reported. The patients were elderly men and died from pulmonary complications, including pneumothorax, pulmonary haemorrhage and pneumonia, associated with metastatic tumours in the lungs. The data recorded from 95 autopsies of patients with angiosarcoma in Japan during 1980-1984 were analyzed. According to the anatomical distribution of the primary tumour, the patients could be subdivided into a scalp group and non-scalp group. In both groups, the most common metastatic site was the lung. The patients of the scalp group had more frequent pulmonary complications such as pneumonia, haemothorax, atelectasis and pneumothorax, when compared with the patients of the non-scalp group. In particular, pneumothorax was observed only in the patients of angiosarcoma of the scalp. The results indicate that angiosarcoma of the scalp tends to metastasize to the lung, especially to the subpleural or surface pleural area and these metastatic tumours are prone to necrosis, causing characteristic pulmonary complications.

Aged↗
PubMed1987

The cytotoxicity of cysteinylcatechols and related compounds to human melanoma cells in vitro.

L-3,4-Dihydroxyphenylalanine (L-dopa) and its structural analogs are known to be potently cytotoxic to melanoma cells. We examined the effects of cysteinylcatechols and related compounds, which were newly synthesized as cysteinyl derivatives of L-dopa, on the growth of human melanoma cells in vitro, and their actions were compared with those of L-dopa. 4-S- and 3-S-Cysteinylcatechols showed significantly more potent cytotoxicity to melanoma cells than did L-dopa, and 2-S-cysteinylhydroquinone was next to the catechols in potency. The mechanism of action may involve interaction with the melanocyte-specific enzyme, tyrosinase, for which the cysteinylcatechols could become a better substrate than L-dopa itself. 4-S-Cysteaminylphenol was almost comparable to L-dopa in cytotoxicity, suggesting that this phenol might be oxidized to the corresponding catechol by tyrosinase within the melanoma cells.

Antineoplastic Agents↗
PubMed1987

Melanocytes in the nasal cavity and paranasal sinus. Incidence and distribution in Japan.

Random, nonselected tissue specimens from 99 Japanese-20 cylindrically cut nasal blocks removed during autopsy (A.C., Autopsy Cases) and 79 cases removed during surgery, consisting of 32 chronic sinusitis cases (C.S.) and 47 nasal polyp cases (N.P.)-were examined histopathologically and electronmicroscopically with respect to distribution and frequency of melanocytes in the nasal cavity and paranasal sinus. Malignant melanoma cases were excluded. The overall incidence of positive cases for melanocytes revealed 21.2% (21 of 99 cases), with an incidence ratio of male to female of 0.9:1.0. Melanocytes were found beginning in the under 19 age group with incidence increasing proportionately with age. Peak incidence was in the 50-year age group at 50%. Melanocytes and melanotic cell foci were distributed in the stroma of the propria mucosa beneath the pseudostratified columnar epithelium and focused around the nasal and paranasal glands and sinuses. In 2 of the 21 cases positive for stromal melanocytes, intraepithelial melanocytes with dendritic processes were found. The histogenesis of malignant melanoma arising from the nasal cavity and paranasal sinus are also discussed in this study.

Adolescent↗
PubMed1987

Induction of melanogenesis in Schwann cell and perineural epithelium by 9,10-dimethyl-1,2-benzanthracene (DMBA) and 12-o-tetradecanoylphorbol-13-acetate (TPA) in BDF1 mice.

Six-week-old female BDF1 mice were treated with a single topical application of DMBA followed by repeated application of TPA on the clipped dorsal skin. Several weeks after DMBA application, the intradermal melanocytes of perifollicular melanocytic network began to proliferate to form melanocytic tumors in all treated mice skin. Besides these changes, single membrane-bound melanosomes and premelanosomes were found in the cytoplasm of perineural epithelia and Schwann cells with mesaxons of the nerve bundles involved, and the melanogenic activity of the Schwann cell and the perineural epithelium of the dermal peripheral nerve bundle was discussed in terms of a common feature of neuro-ectodermal cells.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1987

Analysis of morphological factors of hepatocellular carcinoma in 98 autopsy cases with respect to pulmonary metastasis.

The morphological features of ninety-eight autopsy cases of hepatocellular carcinoma (HCC) were analyzed in relation to pulmonary metastasis. Extrahepatic hematogenous metastasis was observed in 64% and lung was most frequently involved (62%). A close relationship was observed between intrahepatic vascular invasion and extrahepatic hematogenous metastasis to lungs. Portal vein-invasion was found in 80% of cases and significant correlations were recognized between the rates of portal vein-invasion and hepatic vein-invasion, and between the rates of portal vein-invasion and pulmonary metastasis. There was a close correlation among the macroscopic growth-pattern, incidence of vascular invasion, and pulmonary metastasis, and their degrees. Namely, the expansive type HCC showed significantly lower rates of vascular invasion and pulmonary metastasis than the infiltrative or mixed type HCC. These rates were particularly low in the expansive type, single nodular subtype HCC with size of a primary tumor less than 10 cm. Significantly low rates of pulmonary metastasis and portal vein-invasion were also noted in well-differentiated carcinoma (Grade I or II). The existence of cirrhosis or fibrosis of liver in cases with HCC was not definitely related to the occurrence of pulmonary metastasis. It was originally clarified that invasion to the portal vein and the size of HCC played a main role in pulmonary metastasis.

Adult↗
PubMed1987

Histological localization of 4-S-cysteinylphenol in melanoma-bearing mice.

4-S-cysteinylphenol (4-S-CP), the S-homologue of tyrosine, has been recently synthesized as a selective chemotherapeutic agent against malignant melanoma and has been shown to be a specific substrate for tyrosinase in vitro. In vivo incorporation of 4-S-CP into the B16 and Harding Passey (HP) melanomas and the systemic organs have been evaluated by the autoradiographic method. The distribution of the silver grains indicated that 4-S-CP was selectively incorporated into both the B16 and HP melanomas. 4-S-CP was excreted mainly from the kidneys and there was an accumulation of 4-S-CP in the reticulo-endothelial system. These results seemed to contribute to the utilization of 4-S-CP and other related compounds as chemotherapeutic agents against malignant melanoma.

Animals↗
PubMed1986

Pathological changes of the lungs after prolonged inhalation of high concentrations of oxygen.

The pathological changes in the lungs of six patients who were treated by an artificial ventilation with a Bird or Bennett type respirator for three days to six months with oxygen concentrations of 24-100% were examined by light microscopy, studies on thick-sections, reconstruction models and vascular casts, and morphometric methods. After prolonged inhalation of high concentrations of oxygen the lungs showed thickening of the alveolar wall, marked deposition of reticulin fibers and fibroblastic proliferation in the alveolar wall, reduction in the number of capillaries, an abnormal configuration of the capillary network and hyperplasia of alveolar lining cells. These lesions are not specific to this condition, and seemed to be less marked than similar lesions in cases of chronic forms of fibrosing alveolitis, chronic interstitial pneumonia, usual interstitial pneumonia and so-called pulmonary fibrosis. Morphometric results confirm these histological observations and show not only the concentrations of oxygen but also the duration of high and pure oxygen inhalation have important roles for these pulmonary lesions. The main reasons for these lesions seemed to be repeated damage to the capillaries and loss of the normal configuration of the capillary network, accompanied by rearrangement and reconstruction of the two types of reticulin fibers.

Adult↗