A structural model for the mechanisms of elicitor release from fungal cell walls by plant beta-1,3-endoglucanase.

The release of elicitor-active carbohydrates from fungal cell walls by beta-1,3-endoglucanase contained in host tissues has been implicated as one of the earliest processes in the interaction between soybean (Glycine max) and the fungal pathogen Phytophthora megasperma f. sp. glycinea leading to host defense responses such as phytoalexin production. The present study was conducted to evaluate the primary structure of the glucanase-released elicitor (RE). Gel-filtration chromatography of carbohydrates released from mycelial walls by purified soybean beta-1,3-endoglucanase resolved them into the four fractions (elicitor-active RE-I, -II, and -III and elicitor-inactive RE-IV). Sugar composition analysis indicated that all of the fractions were composed almost entirely of glucose. 1H- and 13C-nuclear magnetic resonance analysis indicated the presence of both beta-1,3- and beta-1,6-linkages for the elicitor-active RE-I, -II, and -III fractions and only beta-1,3 linkage for the elicitor-inactive RE-IV fraction. Methylation analysis and degradation studies employing beta-1,3-endo- and beta-1,3-exoglucanase further suggested that the basic structure of elicitor-active RE consists of beta-1,6-linked glucan backbone chains of various lengths with frequent side branches composed of beta-1,3-linked one or two glucose moieties. From these structural analyses of RE, a structural model of how RE is originally present in fungal cell walls and released by host beta-1,3-endoglucanase is also proposed.

The long-term results of pre-operative hyperthermo-chemo-radiotherapy for oesophageal carcinoma--a comparison with preoperative radiation therapy alone.

The long-term results of patients with oesophageal carcinoma treated with pre-operative hyperthermo-chemo-radiotherapy (HCR) and pre-operative radiation therapy alone were compared. Twenty-six patients treated with pre-operative hyperthermo-chemo-radiotherapy (HCR Group) and 25 treated with radiation therapy alone (R Group), which demonstrated histopathologically marked effective results (Grade 3), were entered into the study. The 3-year survival rates after oesophagectomy in the HCR Group and the R Group were 67.4% and 41.8%, respectively, while the 5-year survival rates were 50.5% and 34.9%, respectively. Thus post-operative prognosis in the HCR Group was significantly more favourable than that in the R Group (P < 0.05). The local recurrence and distant metastasis rate in the HCR Group was significantly less than in the R Group (P < 0.01). This significant difference in prognosis was thought to be due to the reinforced effects of local regulation by hyperthermia and the systemic control of micrometastasis by chemotherapy in addition to radiation. Our data suggest that for carcinoma of oesophagus, pre-operative hyperthermo-chemo-radiotherapy contributes to prolonged post-operative survival while reducing both local recurrence and micrometastasis.

Hyperthermochemoradiotherapy is effective for small cell carcinoma of the esophagus.

Esophageal small cell carcinoma is a highly aggressive disease, and no effective treatment has yet been reported. We present here two cases of esophageal small cell carcinoma preoperatively treated with a combination of hyperthermia, irradiation, and an intravenous infusion of cis-diammine-dichloroplatinum (CDDP). The first case concerned a 67-year-old Japanese woman. Hyperthermochemoradiotherapy (HCR) was performed before surgical treatment. A histopathologic study of the resected specimen showed no residual viable cancer cells either in the esophagus or in the dissected lymph node. The second case involved a 59-year-old Japanese man who received HCR therapy before surgical treatment. This patient survived for 33 months, the longest known period of survival for small cell carcinoma of the esophagus. These cases indicate that preoperative hyperthermochemoradiotherapy may be considered one promising adjuvant therapy alternative for this aggressive disease.