Angiopoietin-2-induced lymphatic endothelial cell migration drives lymphangiogenesis via the β1 integrin-RhoA-formin axis

Lymphangiogenesis is an essential physiological process but also a determining factor in vascular-related pathological conditions. Angiopoietin-2 (Ang2) plays an important role in lymphatic vascular development and function and its upregulation has been reported in several vascular-related diseases, including cancer. Given the established role of the small GTPase RhoA on cytoskeleton-dependent endothelial functions, we investigated the relationship between RhoA and Ang2-induced cellular activities. This study shows that Ang2-driven human dermal lymphatic endothelial cell migration depends on RhoA. We demonstrate that Ang2-induced migration is independent of the Tie receptors, but dependent on β1 integrin-mediated RhoA activation with knockdown, pharmacological approaches, and protein sequencing experiments. Although the key proteins downstream of RhoA, Rho kinase (ROCK) and myosin light chain, were activated, blockade of ROCK did not abrogate the Ang2-driven migratory effect. However, formins, an alternative target of RhoA, were identified as key players, and especially FHOD1. The Ang2-RhoA relationship was explored in vivo, where lymphatic endothelial RhoA deficiency blocked Ang2-induced lymphangiogenesis, highlighting RhoA as an important target for anti-lymphangiogenic treatments.

     

Infective endocarditis in diabetic and non-diabetic patients

We compared clinical, microbiological, and prognostic characteristics of infective endocarditis in patients with and without diabetes mellitus. In 1987--1996, 213 patients with definite or possible infective endocarditis were included, of which 39 (18%) had diabetes mellitus. Diabetic patients were older than non-diabetic (median age of 71 vs 65 y, respectively; p =0.04), had more aortic valve and less mitral valve involvement (71% vs 27%, and 21% vs 62%; p = 0.004). There was no significant difference in the frequency of Staphylococcus aureus involvement between the 2 groups (21% in diabetic vs 20% in non-diabetic group; p = ns). On multivariate analysis diabetes mellitus was not found to be an independent factor for mortality. Unlike other infections diabetes mellitus does not significantly affect clinical and microbiological features, and outcome of infective endocarditis.     

Experience with the continuous glucose monitoring system in a medical intensive care unit

Strict glycemic control improves clinical outcomes in critically ill patients. However, practical tools for frequent monitoring of blood glucose (BG) levels in the intensive care unit (ICU) are limited. The Continuous Glucose Monitoring System (CGMS, Medtronic MiniMed, Northridge, CA) is currently approved for detecting glycemic excursions in outpatients with diabetes mellitus. The use of this device has never been carefully examined in the inpatient setting. This preliminary study was designed to investigate the accuracy of the CGMS in critically ill patients admitted to a medical ICU (MICU). Subjects at risk for hyperglycemia were recruited from among all patients admitted to our MICU. CGMS sensors were implanted for up to 72 h. Study subjects wore between one and five consecutive sensors. Four or more standard capillary BG readings were recorded per 24 h. All paired meter-sensor (M-S) readings were used both for CGMS calibration and for data analysis. Twenty-two MICU patients wore 41 CGMS sensors, yielding 546 M-S BG pairs. Overall, the Pearson correlation coefficient ( r ) was 0.88, with a mean M-S difference of 3.3 +/- 26.7 mg/dL (0.6 +/- 17.4%) and a mean absolute M-S difference of 19.7 +/- 18.3 mg/dL (12.8 +/- 11.9%). Clarke Error Grid analysis categorized 98.7% of the M-S pairs within "clinically acceptable" zones A and B. The CGMS is promising for potential use in critically ill patients. If validated in larger studies, the device could serve as a useful research tool for investigating the role of hyperglycemia (and strict glycemic control) in ICU patients. If further developed as a "real-time" glucose sensor, CGMS technology could ultimately prove clinically useful in the ICU, by decreasing nursing workload and/or by providing alarm signals for impending glycemic excursions.     

Mitral valve repair for dilated cardiomyopathy: predictive role of right ventricular dysfunction.

AIMS: To evaluate the impact of right ventricular (RV) dysfunction on early and mid-term outcome of patients with ischaemic or dilated cardiomyopathy (DCM) undergoing mitral valve annuloplasty. METHODS AND RESULTS: From January 1997 to December 2005, 111 patients with DCM (89 ischaemic, 22 non-ischaemic) were enrolled in this retrospective study. Mean age was 67 +/- 10 years. Average pre-operative NYHA class was 3.0 +/- 0.6. Tricuspid annular plane systolic excursion (TAPSE), tricuspid annular pleak systolic velocity (TAPSV), and RV fractional area change were considered as an index of RV function. A strong relationship between TAPSE and TAPSV were found (r = 0.76). Thirty-day mortality was 10.8%. Five-year survival and possibility to be alive in NYHA classes I-II were 66.5 +/- 5.0 and 59.5 +/- 5.0%. TAPSE, TAPSV, and MV coaptation depth (MVCD) were found to be risk factors for worse early and mid-term outcome; functional class impaired mid-term outcome. ROC analysis identified TAPSE < or = 12 mm, TAPSV < or = 10 cm/s, and MVCD>10 mm as predictive cut-offs. CONCLUSION: Pre-operative assessment of some echocardiographic parameters (TAPSE, TAPSV) is very easy, low cost, and provides accurate information on RV function. A good pre-operative clinical compensation has to be necessarily reached before the operation. MVCD should be evaluated to decide surgical strategy (repair or replace).     

Redo pouches: Salvaging of failed ileal pouch-anal anastomoses

From October 1, 1984 to December 31, 1991 at the Clinica Chirurgica II of the University of Bologna, 140 patients submitted to ileal pouch-anal anastomosis for ulcerative colitis (UC) and familial adenomatous polyposis (FAP). Nineteen patients (13.5 percent) developed septic complications. Of these, 11 patients (7.8 percent) had pelvic sepsis. Eight patients required further surgical intervention. Five patients underwent the redo pouch procedure. Another redo pouch was performed in a patient who had previously, in another hospital, had an ileal pouch-anal anastomosis placed and then removed because of ischemic necrosis of the reservoir. No deaths are reported in the reoperated patients. Currently, five of the six patients who underwent the redo pouch procedure have a well-functioning ileoanal anastomosis. The redo pouch procedure should always be attempted prior to the establishment of pelvic fibrosis.     

The potential of myocardial perfusion scintigraphy for risk stratification of asymptomatic patients with type 2 diabetes.

Patients with diabetes, in particular patients with type 2 diabetes, are at a 2- to 4-fold higher risk of cardiovascular mortality compared with their nondiabetic peers. Patients with diabetes are also more likely to have silent ischemia and less likely to survive a myocardial infarction than nondiabetic patients. Recent studies with electron beam computed tomography (EBCT) have shown that subclinical atherosclerosis is common in patients with diabetes, and studies with myocardial perfusion scintigraphy (with single-photon emission computed tomography) or stress echocardiography have demonstrated that between 25% and 50% of asymptomatic diabetic patients have ischemia during exercise or pharmacological stress and that a substantial proportion of these patients go on to develop major cardiovascular events within several years. Clearly, asymptomatic diabetic patients include a subset of individuals at high risk of cardiovascular disease who would benefit from improved risk stratification beyond that possible with risk factor scoring systems alone. Single-photon emission computed tomography, stress echocardiography, and possibly EBCT or multi-slice computed tomography, are emerging as valuable diagnostic tools for identifying asymptomatic diabetic patients who might require early and aggressive intervention to manage their cardiovascular risk.     

Management of small-cell lung cancer in the elderly.

More than 50% of lung cancer patients are diagnosed over the age of 65 and about 30% over 70. Small-cell lung cancer (SCLC) accounts for 20-25% of lung carcinomas. Chemotherapy is the cornerstone of treatment for SCLC. Usually in the elderly it is difficult to administer the same chemotherapy administered to younger patients because elderly patients tolerate chemotherapy poorly. The empirical reduction of drug doses may be criticized. The best approach is to design specific trials in order to develop active and well-tolerated chemotherapy regimens for SCLC elderly patients. The standard therapy in limited disease is combined chemo-radiotherapy followed by prophylactic brain irradiation for patients achieving a complete response. In the elderly, the addition of radiotherapy to chemotherapy must be accurately evaluated, considering the slight survival improvement and the potential relevant toxicity.     

“Atypical” multidrug resistance in human ovarian cancer cell line A2780 selected for resistance to doxorubicin (A2780 DX3)

Human ovarian cancer cells A2780, selected for resistance to doxorubicin (A2780-DX3), are crossresistant to various other topoisomerase-II-targeted drugs but not to vinblastine. The parental cell line was very sensitive to doxorubicin-, mitoxantrone- or etoposide (VP16)-induced DNA single-strand breaks, under deproteinizing conditions. In contrast, little or no DNA strand breakage was seen in resistant A2780-DX3 cells, even at very high concentrations, indicating a good correlation, with cytotoxicity. No significant alterations in cellular drug uptake were observed in DX3 cells. Further studies showed that the nuclei isolated from resistant cells were also resistant to mitoxantroneor VP16-induced single-strand breaks, indicating that nuclear modifications in resistant cells are responsible for this resistance. Catalytic activity in crude nuclear extracts from wild-type and DX3 cells was almost equal. However, an assay that specifically measures generation of 5-protein-linked breaks in³²P-labeled 3 DNA revealed that, DNA cleavage activity in nuclear extract from the DX3 cell line is profoundly resistant to a stimulation by VP16. These data indicate that stimulation of topoisomerase-II-mediated DNA cleavage is responsible for topoisomerase-II-targeted drugcytotoxicity rather than loss of normal topoisomerase catalytic function. These data support the hypothesis that A2780-DX3 cells display an atypical multidrug resistance.Abbreviations MDR multidrug resistance - SSB Single-strand break