Increased expression of phosphorylated NBS1, a key molecule of the DNA damage response machinery, is an adverse prognostic factor in patients with de novo myelodysplastic syndromes.

The expression of activated forms of key proteins of the DNA damage response machinery (pNBS1, pATM and γH2AX) was assessed by means of immunohistochemistry in bone marrow biopsies of 74 patients with de novo myelodysplastic syndromes (MDS) and compared with 15 cases of de novo acute myeloid leukemia (AML) and 20 with reactive bone marrow histology. Expression levels were significantly increased in both MDS and AML, compared to controls, being higher in high-risk than in low-risk MDS. Increased pNBS1 and γH2AX expression possessed a significant negative prognostic impact for overall survival in MDS patients, whereas pNBS1 was an independent marker of poor prognosis.

Retrograde cardioplegia in CABG: is it really useful? The microcirculation and a capillary unit model.

Most surgeons, ourselves including, use retrograde cardioplegia in numerable operations in cardiac surgery. It is believed to be not only supplementary to antegrade, but also a unique alternative in special complicated cases. Regarding CABGs (coronary artery bypass grafts), many authors advocate its routine use together with antegrade, while others do not suggest it for standard practice. The existing disagreement on this special item is consequential to the different results among various protocols which have studied the effect of antegrade and retrograde perfusion. In these studies, fundamental variations in design, materials, and methods have resulted in an inability to compare results. Additionally, most of the published protocols studying cardioplegic arrest offer only a gross estimation of the microcirculatory perfusion, which is the basis of myocardial protection. Our present review is an attempt to elucidate the differences, explain the necessity of comparing retrograde cardioplegia alone with antegrade in CABGs for the reproduction of safe results, clarify the role of Thebesian veins and venovenous connections during retroperfusion, consider the critical anatomic differences between human hearts and those of animals which may result in serious study bias, and, finally, offer an explanation of what may really be going on in the microcirculation during antegrade and retrograde perfusion using a human capillary model.

Spontaneous rupture of the colon sigmoid following spontaneous recurrent pneumothorax in a patient with Marfan syndrome.

BACKGROUND: Spontaneous ruptures of the colon and rectum are very rare clinical entities and always require laparotomy. In such cases, despite meticulous exploration an underlying pathology cannot be revealed and most reports in the world literature relate spontaneous colon ruptures with unusual connective tissue disorders such as Marfan or Ehlers-Danlos syndrome. Connective tissue diseases affect the structure and the synthesis of elastin and type III collagen, resulting in various systemic disorders. Among the several pulmonary manifestations, spontaneous pneumothorax is observed in about 5% of patients expressing one of the above syndromes. CASE REPORT: In the following report we present a unique case of spontaneous rupture of the sigmoid colon secondary to spontaneous recurrent contralateral pneumothorax. CONCLUSIONS: The aim of this presentation is to raise the level of suspicion in every surgeon and gastroenterologist to include connective tissue disorders in their differential diagnosis in any case of spontaneous colon rupture and, if found, to follow further diagnostic procedures in anticipation of any other visceral complications.