Assessment of patient radiation doses during transcatheter closure of ventricular and atrial septal defects with Amplatzer devices.

The purpose of this study was to estimate the radiation dose to which children are exposed during cardiac catheterizations for the treatment of ventricular and atrial septal defects. Radiation doses were estimated for 46 children aged 1-18 years. These children were treated for secundum atrial septal defects (ASD group) for perimembranous ventricular septal defects (VSD group) or underwent a routine diagnostic catheterization (diagnostic group). Thermoluminescent dosimeters (TLDs) were attached in locations, representing the lateral entrance dose, the posterior entrance dose, the thyroid dose, and the gonad dose, respectively. A dose area product (DAP) meter was also attached externally on the posterior-anterior (PA) tube to give a direct value in cGy cm(2) for each procedure. The patient's entrance dose from the PA field ranged from 1.5 to 185.0 mGy for all patients, while the lateral entrance dose varied from 0.9 to 204 mGy. Radiation exposure to the thyroid and the gonads was found to vary from 0.4 to 8.3 and 0.1 to 2.1 mGy, respectively. The DAP meter recorded DAP values for the posterior tube, between 46 and 3,700 cGy cm(2). The mean effective dose was found to be 7.7, 16.2, and 33.3 mSv for the diagnostic, the ASD, and the VSD group, respectively. Very strong correlation was found between the DAP values and the entrance radiation dose measured with TLDs. The mean entrance dose received from therapeutic cardiac catheterizations using the Amplatzer devices was found approximately twice the dose received from a diagnostic one. Even for the most complex procedures, the maximum entrance dose was at least 10 times lower than the threshold, associated with skin erythema.     

History of Biliary Surgery

Since ancient times biliary surgery has been one of the major interests of doctors and other scientists around the world. From the ancient Greeks and Egyptians to the greatest scientists of modern times biliary surgery has advanced remarkably. Especially during the last century huge progress has been made in this field. Minimally invasive surgical techniques have been developed and combined with general anesthesia and antisepsis that have made biliary surgery particularly safe for every patient and have made cholecystectomy one of the most common operations in the world today.     

Early versus delayed single-stage laparoscopic eradication for both gallstones and common bile duct stones in mild acute biliary pancreatitis

Several studies addressed that preoperative endoscopic retrograde cholangiopancreatography (ERCP) for common bile duct (CBD) clearance, followed by interval laparoscopic cholecystectomy (two-stage approach), constitutes the most common practice in cases of uncomplicated mild acute biliary pancreatitis. Between June 1998 and December 2002, 44 patients (35 females and 9 males with a median age of 62 years) suffering from uncomplicated mild acute biliary pancreatitis were treated in our unit. All patients were electively submitted to surgery after subsidence of the acute symptoms, and for definitive treatment we favored the single-stage laparoscopic management, avoiding preoperative ERCP. All patients underwent laparoscopic cholecystectomy plus fluoroscopic intraoperative cholangiogram (IOC). If filling defect(s) were detected in the IOC, a finding suggestive of concomitant choledocholithiasis, laparoscopic common bile duct exploration (LCBDE) was added in the same sitting. Twenty patients were operated upon within 2 weeks since the attack of the acute symptoms and constitute the early group (n=20), whereas 24 patients underwent an operation later on and constitute the delay group (n=24). We retrospectively compare the safety, effectiveness, and outcome after the single-stage laparoscopic management between the two groups of patients. Laparoscopic cholecystectomy alone constituted the definitive treatment in 38 patients, while an additional LCBDE was performed in the remaining 6 patients (14%), and all operations were achieved laparoscopically. There was no statistically significant difference between the groups in terms of operative time, incidence of concomitant choledocholithiasis, morbidity rate, and postoperative hospital stay. During the follow-up, none of the patients experienced recurrent pancreatitis. In uncomplicated mild acute biliary pancreatitis cases, a single-stage definitive laparoscopic management, avoiding preoperative ERCP, can be safely performed during the same admission, after the improvement of symptoms and local inflammation. Postoperative ERCP should be selectively used in patients in whom the single-stage method failed to resolve the problem.     

Ex vivo synergy of arachidonate-enriched serum with ceftazidime and amikacin on multidrug-resistant Pseudomonas aeruginosa

Three multidrug-resistant strains of Pseudomonas aeruginosa were incubated ex vivo with sera sampled after a 10 min intravenous infusion of 25 mg/kg of arachidonic acid (AA) in 10 rabbits in the presence of ceftazidime and amikacin. Lipid peroxidation was assessed during bacterial growth. A statistically significant decrease in bacterial cells was found by the interaction of antimicrobials and serum sampled in the middle of infusion and 15 and 30 min after infusion of AA and was accompanied by elevated levels of malonodialdehyde. This effect of AA is probably attributed to lipid peroxidation and raises the possibility of its application in experimental infections.     

Increased Mobilization of Mesenchymal Stem Cells in Patients With Essential Hypertension: The Effect of Left Ventricular Hypertrophy

Stem cells have great clinical significance in many cardiovascular diseases. However, there are limited data regarding the involvement of mesenchymal stem cells (MSCs) in the pathophysiology of arterial hypertension. The aim of this study was to investigate the circulation of MSCs in patients with essential hypertension. The authors included 24 patients with untreated essential hypertension and 19 healthy individuals. Using flow cytometry, MSCs in peripheral blood, as a population of CD45−/CD34−/CD90+ cells and also as a population of CD45−/CD34−/CD105+ cells, were measured. The resulting counts were translated into the percentage of MSCs in the total cells. Hypertensive patients were shown to have increased circulating CD45−/CD34−/CD90+ compared with controls (0.0069%±0.012% compared with 0.00085%±0.0015%, respectively; P=.039). No significant difference in circulating CD45−/CD34−/CD105+ cells was found between hypertensive patients'' and normotensive patients'' peripheral blood (0.018%±0.013% compared with 0.015%±0.014%, respectively; P=.53). Notably, CD45−/CD34−/CD90+ circulating cells were positively correlated with left ventricular mass index (LVMI) (r=0.516, P<.001). Patients with essential hypertension have increased circulating MSCs compared with normotensive patients, and the number of MSCs is correlated with LVMI. These findings contribute to the understanding of the pathophysiology of hypertension and might suggest a future therapeutic target.

In recent years there has been growing interest in the role of adult stem cells in the pathophysiology of cardiovascular diseases. Although it used to be believed that mammalian cardiomyocytes cease replication soon after birth and that the subsequent growth of the heart was attributable only to cardiomyocyte hypertrophy, newer studies have demonstrated a small degree of cardiogenesis and cardiomyocyte turnover that occurs throughout life.¹, ² These findings led to further research into the contribution of stem cells to the pathophysiology of cardiovascular disorders that has raised the hope of developing new therapeutic approaches. Stem cells have the potential for self‐renewal and differentiation and are the origin cells of various mature cells.Mesenchymal stem cells (MSCs) are also known to have a highly plastic differentiation potential that includes not only adipogenesis, osteogenesis, and chondrogenesis, but also endothelial, cardiovascular,³ and neovascular differentiation.⁴, ⁵, ⁶ Although present in only very small numbers in peripheral blood, in recent years stem and progenitor cells have been implicated in ventricular remodeling and are thought to be of great clinical significance in the pathophysiology of heart failure and atheromatosis. Previous studies have indicated that MSCs derived from peripheral blood, apart from their multilineage potential, can also be used for cellular and gene therapies.⁷ Human MSCs isolated from adult bone marrow provide a model for the development of stem cell therapeutics and could find application in the cardiovascular system—although this is still under investigation.⁸ Under normal conditions, endogenous cardiac progenitor cells are responsible for homeostasis in the heart.⁹ However, it appears that under conditions of stress, this may change, with stem cells from extra‐cardiac sources also playing a role. An interesting experimental study has shown that an increase in preload results in the mobilization of progenitor cells from the bone marrow for use in neovascularization, which plays an important role in cardiac hypertrophy.¹⁰ There are indications that the recruitment of bone marrow–derived cells is involved in cardiac myocyte hypertrophy and maintenance of function in response to pressure overload.¹¹ A recent study from our department has shown increased expression of myocardin and GATA4 genes in the peripheral blood mononuclear cell fraction of hypertensive patients, implying the presence of mesenchymal progenitor cells in the peripheral blood that could possibly be intended to differentiate into cells of the cardiac series.¹² Interestingly, in the patients in that study, myocardin and GATA4 expression was associated with both blood pressure (BP) levels and left ventricular hypertrophy (LVH).To date, most published reports concerning the cardiovascular applications of stem cells have focused on their role in myocardial infarction and in heart failure. Very little work has been done on arterial hypertension, and most has concerned endothelial progenitor cells. The role and behavior of MSCs in patients with essential hypertension is unknown. In a recent animal study, it was shown that the degree to which angiotensin II increased neointima formation was statistically correlated with the increased incorporation of fluorescent bone marrow–derived smooth muscle cells, and that this was inhibited by angiotensin‐1 receptor antagonism.¹³ Based on the hypothesis that MSCs participate in pathophysiological processes that contribute to hypertension, and on the assumption that the behavior of MSCs is altered in hypertensive patients, we carried out the first flow cytometric analysis of CD45−/CD34−/CD90+ and CD45−/CD34−/CD105+ in the peripheral blood of those patients compared with healthy individuals.