Co-Fermentation of Glucose-Xylose Mixtures from Agroindustrial Residues by Ethanologenic Escherichia coli: A Study on the Lack of Carbon Catabolite Repression in Strain MS04.

The production of biofuels, such as bioethanol from lignocellulosic biomass, is an important task within the sustainable energy concept. Understanding the metabolism of ethanologenic microorganisms for the consumption of sugar mixtures contained in lignocellulosic hydrolysates could allow the improvement of the fermentation process. In this study, the ethanologenic strain Escherichia coli MS04 was used to ferment hydrolysates from five different lignocellulosic agroindustrial wastes, which contained different glucose and xylose concentrations. The volumetric rates of glucose and xylose consumption and ethanol production depend on the initial concentration of glucose and xylose, concentrations of inhibitors, and the positive effect of acetate in the fermentation to ethanol. Ethanol yields above 80% and productivities up to 1.85 gEtOH/Lh were obtained. Furthermore, in all evaluations, a simultaneous co-consumption of glucose and xylose was observed. The effect of deleting the xyIR regulator was studied, concluding that it plays an important role in the metabolism of monosaccharides and in xylose consumption. Moreover, the importance of acetate was confirmed for the ethanologenic strain, showing the positive effect of acetate on the co-consumption rates of glucose and xylose in cultivation media and hydrolysates containing sugar mixtures.

Hodgkin disease, nodular sclerosis type. Implications of histologic subclassification.

BACKGROUND: The prognostic significance of the cellular composition of the nodules of Hodgkin disease, nodular sclerosis type (HDNS), is controversial. METHODS: Tumors from 79 patients with HDNS, who had a median follow-up time of 9.3 years, were studied. RESULTS: Based on British National Lymphoma Investigation criteria, 58 cases were classified as NSI (low-grade) and 21 as NSII (high-grade). The study included 24 male and 55 female patients, aged 10-57 years (mean, 27 years), who presented with Stage I (13 patients [12A, 1B]), Stage II (45 patients [40A, 5B]), or Stage III (21 patients [16A, 5B]) disease. Fifty-three patients had no relapse, 4 died of other causes, and 49 are in complete clinical remission. Twenty-six patients had progression of disease during therapy or relapsed and 17 were successfully salvaged. Overall length of survival was significantly shorter with NSII (P = 0.0001), extensive necrosis (P = 0.0034), high stage (P = 0.0058), and B symptoms (P = 0.030). Multivariate analysis showed that grade had the strongest effect on overall survival (P = 0.0042; hazard ratio = 10.19). The 5-year survival was 100% for NSI patients and 75% for NSII patients. Only B symptoms were significantly associated with risk of relapse after initial therapy (P = 0.030). For patients who relapsed, only histologic grade predicted subsequent disease-free survival (P = 0.0023; hazard ratio = 26.5). Five-year disease-free survival after first relapse was 94% for NSI patients and 11% for NSII patients. CONCLUSIONS: Patients with NSI disease who relapse have a more successful salvage and longer period of survival than do those with NSII disease. Histologic subclassification of HDNS appears clinically relevant, and consideration of histologic subtype may be important when planning therapy.

Adjuvant postoperative radiation therapy for rectal adenocarcinoma.

From October 1975 to August 1988, 261 patients at high risk for local recurrence after curative resection of rectal carcinoma underwent high-dose postoperative irradiation. Patients received 45 Gy by a 4-field box usually followed by a boost to 50.4 Gy or higher when small bowel could be excluded from the reduced field. Since January 1986, patients also received 5-fluorouracil (5-FU) for 3 consecutive days during the first and last week of radiotherapy. Five-year actuarial local control and disease-free survival decreased with increasing stage of disease; patients with Stage B2 and B3 disease had local control rates of 83% and 87% and disease-free survivals of 55% and 74%, respectively. In patients with Stage C1 through C3 tumors, local control rates ranged from 76% to 23%, and disease-free survivals ranged from 62% to 10%, respectively. For patients with Stage C disease, disease-free survival decreased progressively with increasing lymph node involvement, but local control was independent of the extent of lymph node involvement. For each stage of disease, local control and disease-free survival did not correlate with the dose of pelvic irradiation. Preliminary data from this study suggest a trend toward improved local control for patients with Stage B2, C1, and C2 tumors who receive 5-FU for 3 consecutive days during the first and last weeks of irradiation compared with patients who do not receive 5-FU. Current prospective randomized studies are addressing questions regarding the optimum administration of chemotherapy with pelvic irradiation for patients following resection of rectal carcinoma.

Are there patients with stage I rectal carcinoma at risk for failure after abdominoperineal resection?

The clinical courses of 64 patients undergoing abdominoperineal resection for Stage I lower rectal carcinoma (tumors confined to the muscularis propria without lymph node involvement) were reviewed to identify subsets at risk for failure. Twelve of 12 patients with tumors limited to the submucosa remained disease free without evidence of recurrence. Of the 52 patients with muscularis propria involvement, there have been eight failures with three patients having local failure only, three patients with local failure and distant metastases, and two patients with distant metastases only. The 6-year actuarial disease-free survival, local control, and freedom from distant metastases rates for patients with tumors invasive of the muscularis propria were 80%, 84%, and 88%, respectively. Patients with tumors exhibiting vascular/lymph vessel involvement were at even higher risk for failure. Although adjuvant treatment is infrequently advised for these patients, the use of radiation therapy and chemotherapy should be reconsidered for patients with Stage I lower rectal carcinoma, specifically for patients with tumors invasive of the muscularis propria with vascular/lymph vessel involvement.

Intraoperative electron beam radiation therapy for primary locally advanced rectal and rectosigmoid carcinoma.

To improve local control and survival in patients with primary locally advanced rectal and rectosigmoid carcinoma, intraoperative electron beam radiation therapy (IORT) has been used with a combination of moderate- to high-dose preoperative radiation therapy and surgical resection. Sixty-five patients underwent resection with the intention of using IORT if areas at high risk for local recurrence were apparent at surgery. For 20 patients undergoing complete resection with IORT, the 5-year actuarial local control and disease-free survival (DFS) was 88% and 53%, respectively. The results for 22 patients with pathologically documented residual carcinoma were less satisfactory with a 5-year actuarial local control and DFS of 60% and 32%, respectively. In this latter group, local control and DFS correlated with the extent of residual disease: patients with only microscopic disease had a 5-year actuarial local control and DFS of 69% and 47%, respectively, whereas for patients with macroscopic disease, these figures were 50% and 17%, respectively. For 18 patients undergoing complete resection without IORT or additional postoperative radiation therapy, the 5-year actuarial local control and DFS was 67% and 53%, respectively. Because local failure will occur in at least 30% of patients undergoing partial resection with or without IORT as well as patients undergoing complete resection of advanced tumors without IORT, additional postoperative radiation therapy should be considered.

Intraoperative electron beam radiation therapy for recurrent locally advanced rectal or rectosigmoid carcinoma.

A multimodality approach of moderate-dose to high-dose preoperative radiation therapy, surgical resection, and intraoperative electron beam radiation therapy (IORT) has been used for patients with locally recurrent rectal or rectosigmoid carcinoma. The 5-year actuarial local control and disease-free survival for 30 patients undergoing this treatment program were 26% and 19%, respectively. The most important factor predicting a favorable outcome was complete resection with negative pathologic resection margins. The determinant local control and disease-free survival for 13 patients undergoing complete resection were 62% and 54%, respectively, whereas for 17 patients undergoing partial resection these figures were 18% and 6%, respectively. There did not appear to be a difference in local control or survival based on the original surgical resection (abdominoperineal resection versus low anterior resection). However, the likelihood of obtaining a complete resection after preoperative radiation therapy was higher in patients who had previously undergone a low anterior resection than patients undergoing prior abdominoperineal resection. For the 30 patients undergoing external beam irradiation, resection, and IORT, the most significant toxicities were soft tissue or sacral injury and pelvic neuropathy. Efforts to further improve local control are directed toward the concurrent use of chemotherapy (5-fluorouracil with and without leucovorin) as radiation dose modifiers during external beam irradiation and the use of additional postoperative radiation therapy.

[Vertical transmission of immunity against B. pertussis]. / Sulla trasmissione verticale della immunità verso la B. pertussis.

Carrying out serological exams either from the blood of the woman in labor or from the umbilical cord at the moment of the birth, the AA. evaluate the rate of specific anti-pertussis antibodies which are transferred from the mother to the foetus through the placenta. The discovered rates are not quantitatively such to represent a protection from the infection. Certainly, through the breast feeding the newborn receives a further contribution in specific antibodies, but it is also true that the two mechanisms do not always produce additive results. Further, it is to be considered that this kind of protection has only a limited duration. The AA, conclude by hoping that in the near future there will be more efficacious vaccines free from the risk of serious complications, that today can be estimated at values of 1:300.000.