Kaoru Kusama

p53 gene alterations and p53 protein in oral epithelial dysplasia and squamous cell carcinoma.

To examine the expression of p53 protein and gene alterations in oral epithelial lesions including epithelial dysplasias and primary squamous cell carcinomas, immunohistochemical and temperature gradient gel electrophoresis (TGGE) methods were applied to formalin‐fixed and paraffin‐embedded tissues. Morphologically normal mucosal epithelium stained negatively for p53 protein. Three out of 11 (27·3 per cent) epithelial dysplasias and 19 out of 57 (33·3 per cent) primary squamous cell carcinomas stained positively for p53 protein. Although more than half of the cases were positive for p53 protein in stage I, the positive cancer cases were found at other stages with variable frequency. Immunoreactive products were localized in the nucleus, especially in the basal and suprabasal layers. The analysis by TGGE revealed gene alterations in exons 5–8 in 3 out of 3 epithelial dysplasias and 17 out of 19 (89·5 per cent) primary squamous cell carcinomas which were immunohistochemically positive for p53 protein. These results suggest that p53 gene mutation may be involved in carcinogenesis in the oral squamous epithelium even in the early stage of the dysplasia–carcinoma sequence.

Tumor Markers in Human Renal Cell Carcinoma

Localization of tumor markers in human renal cell carcinomas (RCC) was studied by an immunohistochemical method using 12 different monoclonal antibodies (MAbs) recognizing carbohydrate antigens, and 2 polyclonal antibodies against S-100 protein and neuron-specific enolase (NSE), respectively. 115D8, DF3 and the MAb to epithelial membrane antigen (EMA) reacted with 9 of 13 (115D8), 6 of 13 (DF3) and 5 of 12 (MAb to EMA) cases of RCC, respectively. S-100 protein was also found in 10 of 13 cases of RCC. Further immunohistochemical studies showed that tumor cells of all 13 RCCs were strongly positive for NSE. Serum NSE levels of patients with RCC were examined by radioimmunoassay. This examination revealed that increased levels of NSE were detected in 11 of 17 sera of patients with RCC. Positive rates for patients in stages II, III and IV were 100% (10/10). On the other hand, increased levels of CA15-3 were detected in only 2 of 17 sera by enzyme immunoassay. Our results indicate that NSE may be a useful marker for human RCC, especially for those tumors that have broken through the renal capsule.

Pulse granuloma in the wall of a dentigerous cyst

Abstract An unusual case of pulse granuloma in the wall of a dentigerous cyst is presented. The microscopic pattern showed the typical features of a foreign body granuloma containing identifiable particles of leguminous foods in the deeper subepithelial tissue. An interesting feature was metaplastic bone formation in the area of droplet calcification. From the clinicopathologic findings, it was hypothesized that the fragments of pulse were probably introduced through an alveolar sinus tract.

Distribution of IgG subclasses in human fetus

In the early fetal age, immunoglobulins in human composed largely of IgG isotype which transfered from mother through the placenta. A passive transfer of maternal IgG increases with gestational age and maternal IgG begin to disappear at birth. There are four IgG subclasses in human. It has been reported that all four IgG subclasses are also transported from mother across the placenta and may be present in fetal circulation at about 6 weeks of gestation. Initial synthesis of IgM has been detected in the lymphoid tissue of human fetuses at approximately 10 weeks of gestation. A small number of IgG-producing cells appear at 12 weeks and IgA-producing cells at 26 weeks of gestation. Although IgG-producing cells are present in human fetuses, a little is known as to the distribution of IgG subclass-producing cells in human.

Electron Microscopic Study of Human Colostral Cells

Abstract Colostrum contains large numbers of cells and humoral defense factors, that play an important role for the protection of the neonate. While colostral cells have been characterized by immunohistochemical criteria, the fine structure of these cells has not been studied. In this study, colostral cells were examined using a combination of electron microscopy and histochemical techniques. Colostral neutrophils and macrophages were found to contain numerous phagocytic vacuoles that stained positively for acid phosphatase. These suggest that these cells actively phagotized various substances from the environment and that phagocytic vacuoles were secondary lysosomes. Distribution of the peroxidase activity in colostral macrophages suggested that they were derived from the circulation. By SEM, neutrophils were found to be circular or spherical cells and showed a rough surface with several blebs in limited areas, while macrophages ranged in shape from spherical to polyhedral and demonstrated numerous ridges or ruffles over the entire cell surface. Lymphocytes were small spherical cells with a smooth surface and a few villous processes. Macrophages were distinguishable from neutrophils and lymphocytes by size and surface structure.