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Biomedical subjects

S Kodama

Publications and source records attributed to S Kodama.

315 records · Page 18Linked to original sources
PubMedDate not supplied

Lack of expression of antigens for islet cell antibodies in rat fetal pancreas.

It is not clear yet when pancreatic islet cells begin to express antigens for islet cell antibodies (ICA). Therefore, we studied whether human ICA-positive sera, crossreacting with adult rat islet cells, react with fetal and neonatal rat islet cells immunohistologically. The ICA did not react with fetal islet cells. On the other hand, neonatal islet cells over 2-3 weeks of age expressed the reactivities almost similar to those of the adult. It was suspected that pancreatic islet cells started to express their antigens to induce ICA gradually after birth.

Aging↗
PubMedDate not supplied

Heat shock induces centrosomal dysfunction, and causes non-apoptotic mitotic catastrophe in human tumour cells.

Normal human diploid cells and various human tumour cells were heat shocked at 43 degrees C for 2h and allowed to recover at 37 degrees C. It was found that heat shock treatment transiently disrupted the immunostaining of centrosomes, and no centrosome staining was detected in either normal or tumour cells 24h after heat shock. Staining recovered thereafter in normal cells, but in tumour cells abnormal centrosomes, multiple and minute centrosomes were induced. While normal cells were arrested in G1 and G2 after heat shock, significant numbers of mitotic cells with multiple poles appeared in tumour cells. Subsequently, cells with multiple micronuclei increased in tumour cells with time after heat shock. Although the nuclear morphology of these cells was similar to that of the apoptotic cells, no DNA ladder formation was observed up to 4 days after heat shock. Furthermore, an in situ assay failed to detect signals representative of apoptosis, indicating that apoptosis did not appear to be involved in heat shock-induced cell death of human tumour cells. Instead, cell lethality was associated with mitotic catastrophe.

Apoptosis↗
PubMedDate not supplied

N-Methyl-L-serine stimulates hyaluronan production in human skin fibroblasts.

We examined the effects of N-methyl-L-serine (NMS), an amino acid derivative, on hyaluronan (HA) synthesis in human skin fibroblasts. NMS (1-10 mM), but not L-serine, stimulated the incorporation of [(3)H]glucosamine into HA dose-dependently, with a maximum stimulation of 1.5-fold compared to the control. The effect of NMS was specific for HA production, because there was no change in sulfated glycosaminoglycan formation. Neither the N-methyl derivatives of L-glycine or L-alanine, nor N-methyl-D-serine, could stimulate HA synthesis, indicating that the beta-hydroxyl group and the L-configuration were essential for the activity. Gel filtration of the products showed that NMS stimulated the production of high-molecular-mass HA (>10(6) D) without affecting the production of low-molecular-mass HA. NMS required 24 h to stimulate HA production, and when fibroblasts were pretreated for 10-24 h with NMS (1-10 mM), membrane-associated HA synthase activity was increased dose-dependently. Thus, a second messenger is likely to be involved in the stimulation of HA production by NMS.

Amino Acids↗
PubMedDate not supplied

Childhood form of adrenoleukodystrophy in the sucking infant.

The childhood form of adrenoleukodystrophy (ALD) in a sucking infant was discovered before the appearance of clinical symptoms. C24:0/C22:0 and C26:0/C22:0 ratios in umbilical cord plasma were significantly higher so that very long-chain saturated fatty acid-restricted milk was given. Ultrastructural study on biopsied rectal mucosa revealed rectilinear and/or curved electron-lucent clefts in the histiocytes at 3 months of age, which were also recognized in the elder brother and another boy with symptoms of ALD. However, magnetic resonance imaging and T1 and T2 values were within the normal range in cerebral gray matter, cerebral white matter, caudate nucleus, internal capsule, and thalamus.

Adolescent↗
PubMedDate not supplied

Glutathione S-transferase pi immunostaining of cisplatin-resistant ovarian cancer cells in ascites.

OBJECTIVE: To clarify immunohistochemically the correlation between glutathione S-transferase pi (GST pi) expression of surgically resected specimens and clinical response in ovarian cancer and to evaluate ascites cytology using GST pi staining. STUDY DESIGN: Eighty-seven patients with ovarian cancer underwent initial debulking surgery and received cisplatin-based chemotherapy after surgery. Immunostaining for GST pi was performed on formalin-fixed sections of the patients' tumors. The cytologic slides of 24 cases were acquired for evaluation of GST pi staining. RESULTS: Of 87 surgically resected specimens, 55 (63.2%) were GST pi positive. Twenty-five of 28 patients (89.3%) who showed no response to chemotherapy had GST pi-positive tumor cells. The predictive value of positive GST pi staining for drug resistance was 75.8% (25/33). Of 18 cases that were GST pi positive in surgically resected specimens, 17 were positive in ascites cytology. Five cases were negative in both resected specimens and ascites cytology. There was a significant correlation in the GST pi labelling index between resected specimen and ascites cytology from the same case; the correlation coefficient was .701 and P value < .001. CONCLUSION: Overexpression of GST pi is related to resistance to cisplatin, and GST pi staining of ascites cytology can be used in pretherapeutic assessment of patients with ovarian cancer.

Adult↗
PubMedDate not supplied

Surgical management of large hepatocellular carcinomas: criteria for curative hepatectomy.

This study was designed to determine the criteria for curative resection in hepatectomy for large hepatocellular carcinoma. The extent of resection was closely related to recurrence rate, and complete removal of the involved segments was found to be essential for curative hepatectomy. Patients with satellite nodules had a high incidence of recurrence; in fact, carcinoma recurred in all patients, with satellite nodules scattered through more than one segment, despite whole tumor removal. However, curative resection could be achieved in patients with portal involvement confined to the second portal branches, when the tumor, including tumor thrombi, was removed en bloc. On the basis of these results, we define complete en bloc removal of the involved segments, including portal involvements, as curative resection, even though curative hepatectomy is not attainable in patients with satellite nodules in more than one segment and/or tumor thrombi in the first branches or truncus of the portal vein.

Carcinoma, Hepatocellular↗