Electrochemical properties of self-assembled monolayers of tripod-shaped molecules and their applications to organic light-emitting diodes.

Self-assembled monolayers of a tripod-shaped conjugated-thiol grafted onot Au(111) substrates are found to show electrochemically reversible oxidation and reduction and to improve electroluminescence performances of organic light-emitting diodes.

A case of aberrant pancreatic cancer in the jejunum.

We report a case of aberrant pancreatic cancer of the jejunum in a 63 year-old man. The patient was admitted to our hospital with epigastric discomfort and vomiting due to obstruction of the jejunum. Laparotomy revealed a submucosal tumor on the jejunum with multiple liver metastases. Histological examination showed the tumor to be a well differentiated tubular adenocarcinoma originating from aberrant pancreatic tissues lacking islets. Only 1 case of aberrant pancreatic cancer in the jejunum has been previously reported in the literature.

Expression of oncogene products and growth factors in early gallbladder cancer, advanced gallbladder cancer, and chronic cholecystitis.

The expression of oncogene products and growth factors (epidermal growth factor, transforming growth factor-beta, erbB-2, ras p 21, and c-myc) in gallbladder cancer and chronic cholecystitis was measured by immunohistochemical staining on paraffin-embedded serial sections. Expression of these products was graded according to staining intensity in an area of positively stained cells. This study reports the detection of oncogene products and growth factors in cholecystitis as well as in early and late gallbladder cancer. The multiexpression of oncogene products and growth factors was greater for both gallbladder cancer groups as compared with the cholecystitis group. The percentage of epidermal growth factor positivity diminished with increased proportion of interstitial tissue and, conversely, the percentage of transforming growth factor positivity increased with increased proportion of interstitial tissue. The proportion of ras positivity was significantly greater in both early and advanced cholecystic cancer as compared with cholecystitis, but also was considerable even for cholecystitis. These results suggest that various oncogenes may have significant roles in gallbladder cancer and that collagen synthesis is reduced by epidermal growth factor and enhanced by transforming growth factor-beta.

Immunohistochemical study of epidermal growth factor and transforming growth factor-beta in the penetrating type of early gastric cancer.

We report that the penetrating type of early gastric cancer (PEN) is a specific type of early gastric cancer and that the poorly differentiated PEN type could be considered an initial lesion of linitis plastica-type cancer. We performed an immunohistochemical study to clarify the role of growth factors (epidermal growth factor [EGF] and transforming growth factor-beta [TGF-beta]) in the PEN type of early gastric cancer. The results indicated that the PEN type of early gastric cancer has a high growth capacity. Moreover, it was suggested that EGF was involved in its specific infiltrative growth and that both EGF and TGF-beta were involved in its specific scirrhous growth. From these findings, it was assumed that the immunohistochemical staining of EGF and TGF-beta in endoscopic biopsy specimens was useful for the diagnosis of the PEN type of gastric cancer and also for the diagnosis of the initial lesion of linitis plastica-type gastric cancer.

Different origin of leiomyoblastoma by immunohistochemical study.

Leiomyoblastoma has been regarded as a neoplasm of smooth muscle origin. With recent progress in immunohistostaining techniques, many clinicopathological discrepancies have been pointed out about the origin of leiomyoblastoma. It has been claimed that gastrointestinal non-epithelial tumors should be regarded as stromal tumors in order to study their origin. In the present study, we performed various forms of immunohistostaining in seven cases of leiomyoblastoma to determine their origin. One case expressed desmine and muscle specific actin and was considered to be derived from smooth muscle. Four neoplasms expressed X-100 protein (two cases were also NSE positive) and were thought to be derived from the nerve. Two cases were of unknown derivation. These results suggest that the cells of leiomyoblastoma may arise from a primitive to totipotential cell of neural lineages that may anomalously express smooth muscle filaments.

Endoscopic mucosectomy for early gastric cancer using modified strip biopsy.

We present a modification of strip biopsy (SB), one of the endoscopic treatment modalities for early gastric cancer. Using a side-viewing endoscope and a special electrocautery snare, we treated 6 patients with early carcinoma of the intestinal type with this modified strip biopsy (MSB). All tumors could be completely resected and 5 patients were not operated on: All 5 remained tumor-free at follow-up of at least one year. These results compared favorably with a historical control group of 17 patients with early gastric cancer treated with conventional strip biopsy. We therefore recommend applying our new method of MSB especially in the intestinal type of early gastric carcinoma; these preliminary data however, need confirmation in larger trials.

[Clinicopathological and immunohistochemical study on penetrating and superficial spreading type of early gastric cancers].

Specific type of early gastric cancer based on the cancer surface area and the degree of invasion were studied by measuring digital values of the cancer surface area in early gastric cancer patients. The results indicated that the pen and super type of early gastric cancer had many clinicopathological characteristics as compared with common type of early gastric cancer. An immunohistochemical study also revealed that the pen type of early gastric cancer had a high growth activity. Moreover, it was suggested that EGF was involved in its specific invasion and growth, and that EGF and TGF-beta affected its scirrhous growth. The possibility that the poorly differentiated pen type is an early lesion of linitis plastica type gastric cancer was also considered. From these findings, it was assumed that the immunological staining of EGF and TGF-beta in biopsy specimens might be useful in the diagnosis of the pen type of early gastric cancer and also in diagnosis of early lesion of linitis plastica type gastric cancer.

[An autopsy case of extramural malignant leiomyoblastoma of the stomach with ovarian cancer: an immunohistochemical study].

The subject was an 85-year-old woman, who had been diagnosed as having an ovarian cancer and carcinomatous peritonitis and had been treated conservatively. She subsequently died from respiratory and renal insufficiency, and the autopsy that followed revealed that her pelvic cavity had been filled by a tumorous mass that size of a child's head. Histologically, the tumor was a serous cystadenocarcinoma of the ovary. Moreover another tumor, also the approximate size of a child's head, was found sited extramurally, beneath the posterior wall mucosa of the stomach body. Histological inspection of this tumor revealed a proliferation of round oval, and spindle-shaped tumor cells. A vacuolation of the cytoplasms and karyomitosis to the extent of 10/50 HPF also were observed. Based on the findings of being positive for Vimentin and a negative EMA, this tumor was diagnosed as being a malignant leiomyoblastoma of the stomach smooth muscle. The leioblastoma is a relatively uncommon neoplasm, and recent advances in immunohistochemical staining have indicated that some of these tumors are not only of smooth muscle derivation but also of nerve origin. Therefore, this tumor, given its morphological characteristics, had been generalized in this case as a gastric stromal tumor, and with negative findings for Desmin and S-100 protein, as well as positive for Vimentin.