Extended and total aortic resection in the surgical treatment of acute type A aortic dissection: experience with 54 patients

Fifty-four patients with acute type A aortic dissection were surgically treated with extended aortic resection. The age of the patients ranged from 22 to 75 years, and all of them were in very critical condition. In 50 patients, the resection extended from the aortic valve (included in 33) to the beginning of the descending thoracic aorta and in 4, from the valve (included in 3) to the aortic bifurcation. Deep hypothermia and circulatory arrest were employed during the aortic arch resection; inclusion of the graft at the end of procedure was done in 44 patients; in the others, the diseased aortic wall was excised. Early mortality was 20 +/- 6% (11/54). Nine deaths were due to persistence of the distal dissection. Acute type A aortic dissection with aortic valve insufficiency should be treated as an emergency with extended aortic resection. As far as control of bleeding and closure of distal dissection are concerned, the best results have been achieved when the diseased aortic wall has been completely excised.     

Searching for Wolbachia (Rickettsiales: Rickettsiaceae) in mosquitoes (Diptera: Culicidae): large polymerase chain reaction survey and new identifications

Bacteria of the genus Wolbachia constitute a group of intracellular and maternally inherited micro-organisms that are widespread in arthropods, inducing several reproductive disorders such as cytoplasmic incompatibility in their hosts. Considering relevant biological implications related to the presence of Wolbachia in several insect orders, for example its potential role as mechanism for rapid speciation and as vehicle to drive genetic markers in wild populations of vectors of medical and veterinary interest, we carried out an extensive polymerase chain reaction survey to detect Wolbachia in several species of mosquito belonging to genera involved in the transmission of pathogens. Five species out of 26 tested have shown to be infected; for four of them this is the first evidence of the Wolbachia infection. A phylogenetic analysis was also performed, positioning the five Wolbachia strains in the phyletic subdivision B.     

Excision of the aortic wall in the surgical treatment of acute type-A aortic dissection

Between March 1986 and September 1988, 38 patients underwent extended aortic resection (aortic valve, ascending aorta, and arch) for acute type-A aortic dissection with aortic valve insufficiency; deep hypothermia and circulatory arrest were used. All patients were operated on within 17 hours of the onset of symptoms. In the first 24 patients, operation was performed by the "inclusion technique." In the last 14 patients, the "excision technique" was used: the ascending aorta and arch was excised, and the aorta was transected at the beginning of the descending thoracic tract. Excision and transection were considered essential to prevent back flow from the false lumen, which is the main source of bleeding, and to allow all anastomoses to be constructed beyond the limits of dissection. The only anastomosis to the dissected aorta was at the distal end of the graft. One of the 14 patients died (7.1%). One patient was reopened for bleeding: blood was issuing from the attachment of the carotid trunks, and the defect was repaired by interposing a bifurcated Dacron graft between the arch graft and the carotid arteries. Extended aortic excision meets the principle of either eliminating as far as possible the diseased aorta or controlling intraoperative and postoperative bleeding. An operation of great magnitude can be considered a life-saving procedure when compared with the high risk of acute type-A aortic dissection.     

Management of Malignancy-Associated Pleural Effusion

Management of recurrent malignant pleural effusion, a common complication of malignancy, poses a challenge to clinicians. Although almost one century has elapsed since the introduction of the pleurodesis procedure, the ideal approach and best agent are still to be defined. Optimally, pleurodesis should be done at the bedside with a minimally invasive procedure, and suitable agents to achieve pleural symphysis should be inexpensive, available worldwide and free of adverse effects. To date, no substance completely fulfills these requirements.Silver nitrate should be considered for pleurodesis because of its low cost and ease of handling. Although talc has been used most frequently to induce pleurodesis, reports of death due to acute respiratory failure have raised concerns about the safety of this agent. Tetracycline, an effective alternative used in the past, is no longer commercially available. This agent has been substituted with derivatives of tetracycline, such as minocycline and doxycycline with success rates similar to those with tetracycline. Several antineoplastic agents have been injected into the pleural space with the aim of producing pleural symphysis, the most representative of this group being bleomycin.Recent knowledge of the molecular mechanisms involved in pleural inflammation has brought into focus new substances, such as transforming growth factor β and vascular endothelial growth factor, which may be used as pleurodesis agents in the future. Nevertheless, more studies are necessary to better define the potential of these substances in the induction of pleural symphysis.Ideally, a sclerosing agent should be cost-effective, available worldwide and easily administered. Talc will probably stand as the preferred agent to be used for pleurodesis in malignant pleural effusion because of its efficacy, easy manipulation and handling. However, further investigation is necessary to minimize adverse effects related to talc.     

Tacrolimus plus mycophenolate mofetil vs. cyclosporine plus everolimus in deceased donor kidney transplant recipients: three‐yr results of a single‐center prospective clinical trial

We compared in kidney transplantation two immunosuppressive regimens: tacrolimus plus mycophenolate mofetil (MMF) (TAC) and everolimus plus low‐dose cyclosporine (EVE). Sixty consecutive patients received TAC (30 patients) or EVE (30 patients) as immunosuppressive regimen; all subjects also received induction with basiliximab and corticosteroids. After three‐yr follow‐up, no difference was found in patient and graft survival (PTS: TAC: 97% vs. EVE: 100%; GS: TAC: 93% vs. EVE: 93%). The incidence of acute rejection was higher in the EVE group but the difference was not statistically significant (17% vs. 23%, p = ns). Patients in EVE showed higher serum cholesterol (205 ± 41 vs. 235 ± 41 mg/dL, p = 0.0012) and lower hemoglobin concentration (13.6 ± 1.4 vs. 12.4 ± 1.9, p = 0.01). Renal function was not significantly different in the two groups (3 Y creatinine: TAC 1.4 ± 0.8 vs. EVE 1.6 ± 0.8 mg/dL, p = ns). Treatment discontinuation was higher in the EVE group (TAC 17 vs. EVE 36%, p = ns). Our data show that in the middle‐term follow‐up, an immunosuppressive regimen with tacrolimus plus MMF has a similar efficacy and safety profile in comparison with the combination of low‐exposure cyclosporine plus everolimus. Further follow up could evidence the benefits related to the anti‐proliferative effects of everolimus.     

Do Patients Who Participate in a Clinic Experimental Protocol Have the Same Probability of Success From That Who Were Not Selected or Refused To Participate? Outcome Surveillance,Safety, and Bioethical Considerations in Kidney Transplant Clinical Research

Introduction

Safety in conducting a clinical trial is a prerequisite for patients who will be enrolled into that study. The aim of the present study was to evaluate retrospectively if patient and graft survival were similar among patients who participated in clinical trials versus those who did not.

Patients and Methods

We evaluated pretransplant and posttransplant characteristics of 245 kidney transplant (KT) patients who were selected to participate in at least one Phase II/Phase III clinical trial. We compared them with 361 KT patients who were not enrolled or refused to participate in those clinical trials; all studies were conducted at a single transplant center. Inclusion/exclusion criteria were as noted for each individual protocol. Only studies with enrollment at time of graft implant were considered.

Results

Selection of patients participating in clinical trials in general exclude high-risk patients. In our experience, only 36% of transplanted patients were selected for a multicenter, prospective, randomized, international study that included changes to the strategies in the administration of immunosuppressive drugs already on the market or development of a new immunosuppressant. After 5 years, graft and patient survival rates were similar between those who participated and those who did not participate in a clinical study. Although our data were collected retrospectively, an alternative design to achieve these conclusions would be a noninferiority study.

Conclusions

Our results demonstrated similar rates of graft and patient survival among enrolled patients versus nonenrolled patients. Outcome surveillance offers safety in participating in clinical trials that involve changes in standard immunosuppression therapy and are part of the research necessary to develop patient-centered medical interventions.     

HBV infection in HIV-infected subjects in the state of Piauí, Northeast Brazil

In this study, the prevalence, genotype frequency, and risk factors for HBV infection in 768 HIV-infected subjects living in Piauí were determined. Forty-six (6.0 %) HIV-positive subjects were reactive for HBsAg and positive for HBV-DNA. Genotypes A (71.8 %), F (23.9 %) and D (4.3 %) were identified. Multivariate analysis revealed an association between HIV-HBV coinfection and male gender, older age groups, unprotected sex, reporting more than ten sexual partners throughout life, STD, and tattooing. This study shows the importance of monitoring sites and professionals who perform tattooing and practice safe sex to prevent the spread of HIV and HBV infections.