Long-term outcome after acute type A aortic dissection: does an age limit still exist?

AIM: Aim of the study was to analyze outcome in patients who underwent surgery following type A aortic dissections and to evaluate the long-term survival rates in patients 70 years of age and older and those under 70 years of age, and in males as compared to females. METHODS: Between September 1997 and October 2008, 154 patients were retrospectively enrolled. There were 102 males (66.2%) and 52 females (33.8%) with a mean age of 63.5±12; seven patients (4.5%) were over 80 years of age, 46 (29.8%) were between 70 and 80 years of age and 101 were under 70 years of age at the time of surgery. We compared patients 70 years of age and older with those under 70 years of age, analyzing the early and long-term survival results and postoperative complications. RESULTS: Overall in-hospital mortality was 17.5% and permanent neurological dysfunction occurred in 10 patients (6.5%). Twenty patients (12.9%) died during follow-up. Among the males, the long-term survival rate was 80%, 68% and 51% at 1, 5 and 10 years, respectively. Among the females, survival rate was 84.6%, 72.3% and 47.5% at 1, 5 and 10 years, respectively. Five- and 10-year survival rates were 78.1% and 59.4%, respectively, for patients under 70 years of age, and 50.8% at 5 years and 26.1% at 10 years for those over 70. CONCLUSION: Patients might not be excluded from surgical intervention for acute type A aortic dissection (ATAAD) only due to age. It is important to consider biological age and the clinical features of the patients at the time of surgery. Age is a relative but not absolute contraindication for surgery in ATAAD. Long-term survival was not statistically different between males and females.

Axillary and innominate artery cannulation during surgery of the thoracic aorta: a comparative study.

AIM: The aim of this paper was to compare hospital outcomes in patients undergoing elective surgery of the thoracic aorta using the right axillary artery (RAA) and the innominate artery (IA) as a cannulation site for cardiopulmonary bypass (CPB) arterial inflow. METHODS: Between September 2009 and October 2011, 71 patients underwent elective aortic procedures with RAA (N.=27) and IA (N.=44) cannulation. Selection of RAA vs. IA was not randomized, but rather based on surgical judgment of best indication in each patient. Pre-, intra-, and postoperative variables were compared according to cannulation site. RESULTS: Preoperative comorbidities, underlying aortic pathology, and surgical procedures were similar in RAA and IA patients. Hospital mortality was 11.1% and 6.8% in RAA and IA patients, respectively (P=0.243). Overall, 4 brain infarctions occurred, all left sided (RAA: 3.7% vs. IA: 6.8%; P=0.508). One brachial plexus injury, and 1 arterial dissection occurred in RAA group. No cannulation-related morbidity was observed in IA patients. Theoretical CPB flow could be reached in all patients, but resistances through the cannulation sites were more favourable in IA patients. CONCLUSION: RAA and IA were associated with similarly valid results. The choice between the two, based on the specific patient's characteristics, can improve outcomes after aortic surgery.

Purine metabolism in two human melanoma cell lines: relation to proliferation and differentiation.

Purine nucleotide metabolism was studied in two human cutaneous melanoma cell lines IPC182 and IGR221. IPC182 cells do not differentiate, while IGR221 cells differentiate spontaneously at confluency, with intense melanin production. The activities of 11 enzymes involved in the de novo or salvage synthesis or the catabolic pathway of purine nucleotides were measured at different times (from day 3 to day 18), after subculture, during exponential growth and the stationary phase, with or without differentiation. The results demonstrated remarkable differences in the enzyme activity levels and/or the evolution from exponential growth to the stationary phase for each cell line, as well as between the two cell lines. In the non-differentiating IPC182 cells, the activity of enzymes involved in purine nucleotide synthesis decreased when the growth rate slowed down and remained at a low level with a concomitant increase in catabolic activities. In the differentiating IGR221 cells, the activity of enzymes involved in purine nucleotide salvage synthesis increased during the proliferative phase and was maintained at a high level when the cells reached confluency and differentiated; catabolic activities were always lower than in the IPC182 cells. This suggests that extra purine nucleotides, synthesized preferentially by the salvage pathway, could be required for the differentiation of human melanoma cells. Since the two cell lines were cultured in the absence of any differentiation-inducing agents, these results indicate that various metabolic modifications are associated with the natural processes of cell proliferation and differentiation. This research could help to identify some of the enzymes involved in purine metabolism as the targets for the induction of differentiation.

Modulation of antioxidant enzymes p21WAF1 and p53 expression during proliferation and differentiation of human melanoma cell lines.

The activities of antioxidant enzymes, and the expression of p21(WAF1) and p53 proteins were studied at different times after subculture during proliferation and differentiation phases. Two human melanoma cell lines were used: IPC182, which is a non-differentiating cell line, and IGR221, which spontaneously differentiates at the end of the exponential growth phase, as evidenced by a marked increase of melanin content and tyrosinase activity. In the two cell lines, the slowing of proliferation coincided with an increase in the activity and amount of immunoreactive superoxide dismutases (SOD1 and SOD2), and a decrease of catalase and glutathione peroxidase activities, and of the glutathione content. The levels of p21WAF1 and p53 proteins were found to be lower in confluent than in proliferative cells. Several parameters were modified only during the differentiation phase of IGR221 cells; in these cells the increase of tyrosinase activity was highly correlated with the increase in SOD2, GST, glutathione reductase, and G6PD activities. The level of glutathione was found to be lower in differentiated IGR221 than in non-differentiated IPC182 cells. These results suggest that p21WAF1 and p53 proteins are not involved in the spontaneous differentiation process of melanoma cells, and that abnormal regulation of the cell cycle inhibition pathway occurred in these cells. The results sustain the hypothesis that alterations of antioxidant enzyme expression are involved in the control of proliferation and differentiation of melanoma cells. Alterations of SOD2 activity may be of particular importance, since variations are observed with both cell growth and cell differentiation.

Radiation-induced changes in nucleotide metabolism of two colon cancer cell lines with different radiosensitivities.

PURPOSE: To investigate changes in nucleotide metabolism after irradiation. MATERIALS AND METHODS: HT29 and SW48 human colon carcinoma cells were exposed to 60Co gamma-rays at doses ranging from 0 to 7.5 Gy. At different times after irradiation, the activities of nine enzymes involved in nucleotide metabolism were measured, the levels of thymidine kinase and deoxycytidine kinase proteins were evaluated by Western blot, and cell-cycle kinetics were analysed by flow cytometry. RESULTS: Changes in enzyme activities concerned not purine but pyrimidine metabolism and essentially the salvage pathway for deoxyribonucleotide synthesis. They were greater in the less radiosensitive HT29 cells. The levels of thymidine kinase and deoxycytidine kinase proteins changed in parallel with their activities. The metabolic changes in irradiated cells did not seem to be due to S-phase transition and the pattern of enzyme activity changes was different from that observed in proliferative cells. CONCLUSIONS: Radiation-induced changes in the salvage pathway for pyrimidine deoxyribonucleotide synthesis were observed. These findings could be exploited in cancer therapy because higher enzyme activities after irradiation suggest that radiation exposure may render cells more sensitive to the drugs activated by these enzymes.