Molecular characterization,serotyping, and antibiotic susceptibility profile of Leptospira interrogans serovar Copenhageni isolates from Brazil

Leptospira interrogans serogroup Icterohaemorrhagiae is the major serogroup infecting humans worldwide, and rodents and dogs are the most significant transmission sources in urban environments. Knowledge of the prevalent serovars and their maintenance hosts is essential to understand the epidemiology of leptospirosis. In this study, 20 Leptospira isolates were evaluated by pulsed-field gel electrophoresis (PFGE), variable number tandem-repeat analysis (VNTR), serotyping, and determination of antimicrobial resistance profile. Isolates, originated from bovine, canine, human, and rodent sources, were characterized by microscopic agglutination test with polyclonal and monoclonal antibodies and were identified as L. interrogans serogroup Icterohaemorrhagiae serovar Copenhageni. MICs of antimicrobials often used in veterinary medicine were determined by broth microdilution test. Most of tested antibiotics were effective against isolates, including penicillin, ampicillin, and ceftiofur. Higher MIC variability was observed for fluoroquinolones and neomycin; all isolates were resistant to trimethoprim/sulfamethoxazole and sulphadimethoxine. Isolates were genotyped by PFGE and VNTR; both techniques were unable to discriminate between serovars Copenhageni and Icterohaemorrhagiae, as expected. PFGE clustered all isolates in 1 pulsotype, indicating that these serovars can be transmitted between species and that bovine, rodent, and dogs can maintain them in the environment endangering the human population.     

Residual factor VII activity and different hemorrhagic phenotypes in CRM(+) factor VII deficiencies (Gly331Ser and Gly283Ser)

Two cross-reacting material-positive (CRM(+)) factor VII (FVII) mutations, associated with similar reductions in coagulant activity (2.5%) but with mild to asymptomatic (Gly331Ser, c184 [in chymotrypsin numbering]) or severe (Gly283Ser, c140) hemorrhagic phenotypes, were investigated. The affected glycines belong to structurally conserved regions in the c184 through c193 and c140s activation domain loops, respectively. The natural mutants 331Ser-FVII and 283Ser-FVII were expressed, and in addition 331Ala-FVII and 283Ala-FVII were expressed because 3 functional serine-proteases bear alanine at these positions. The 331Ser-FVII, present in several asymptomatic subjects, showed detectable factor Xa generation activity in patient plasma (0.7% +/- 0.2%) and in reconstituted system with the recombinant molecules (2.7% +/- 1.1%). The reduced activity of recombinant 283Ala-FVII (7.2% +/- 2.2%) indicates that the full function of FVII requires glycine at this position, and the undetectable activity of 283Ser-FVII suggests that the oxydrile group of Ser283 participates in causing severe CRM(+) deficiency. Furthermore, in a plasma system with limiting thromboplastin concentration, 283Ser-FVII inhibited wild-type FVIIa activity in a dose-dependent manner.     

Cryothermal mapping of recurrent ventricular tachycardia in man

Intraoperative reversible cryothermal mapping of recurrent ventricular tachycardia was performed in seven patients with left ventricular aneurysms with use of a 0 degrees C ice probe. A single, reproducible cryotermination site was found in each patient. The cryotermination site was uniformly located in an area where local electrograms obtained during ventricular tachycardia showed electrical activation during the diastolic portion of the surface electrocardiogram, and was different than the site of activation coincident with the onset of the QRS complex on the surface electrocardiogram (earliest reactivation site or ERS) by 4.5 +/- 2.7 cm (mean +/- SD) in five of seven patients. Sinus rhythm late potentials were recorded at the cryotermination site in five of six patients and from the ERS in one. In five patients, extensive subendocardial resection including both the ERS and cryotermination sites was performed. In two patients only the cryotermination site was excised. In six survivors, including one in whom only the cryotermination site was excised, ventricular tachycardia could not be induced 2 weeks after surgery and has not recurred during the follow-up period of 7 to 17 months (12 +/- 4.5 months, mean +/- SD). Reversible cryothermal mapping may provide additional important information not obtained by standard electrogram mapping of ventricular tachycardia that may help guide surgical therapy of recurrent ventricular tachycardia.     

MR angiography in abdominal neoplasms

The role of magnetic resonance angiography (MRA) in the evaluation of vascular involvement was studied in 55 patients with abdominal neoplasms. A 2-D time-of-flight (TOF) technique was used in 18 patients. All patients underwent CT and MR examinations before MRA. Also, MR angiograms were compared with digital subtraction angiography in 22 cases, with Doppler US in 13 cases, and with surgical findings in 20 cases. In all patients with liver neoplasms (n = 29) MRA demonstrated the absence of flow in the infiltrated segments. Pericapsular neovascularization was observed in 12 patients. Portal vein involvement was correctly detected in 27 patients. In all cases MRA demonstrated the relationship between the tumor and venous structures. Portosystemic shunts were visualized in 20 of 21 patients with portal hypertension. Vena cava thrombosis (3 cases), compression (5 cases), and displacement (2 cases) were correctly demonstrated. In renal (n = 6) and adrenal gland (n = 3) tumors renal vein compression was correctly detected in 2 cases, displacement in 1 case, and thrombosis in 3 cases, with only 1 false-positive finding. In 7 patients with pancreatic tumors MRA demonstrated splenic vein thrombosis in 2 cases and compression in 2 cases, with one false-positive finding. Our results indicate that MRA provides precise information regarding venous vascular involvement in abdominal neoplasms, but preoperative arterial mapping is still problematic. Correspondence to: E. Squillaci     

Ministernotomy versus median sternotomy for aortic valve replacement: a prospective, randomized study

Background. Minimally invasive aortic valve replacement reduces surgical trauma and, supposedly, postoperative pain, blood loss, and length of stay. A prospective, randomized study was designed to prove these theoretical advantages.

Methods. Forty patients undergoing isolated, elective aortic valve replacement were randomized into two equal groups. Patients in group M underwent aortic valve replacement through a ministernotomy (reversed or reversed ). In group S, a median sternotomy was used. The anesthetic and surgical protocol was identical for both groups. Pain was evaluated on a daily basis. Pulmonary function tests were performed preoperatively and before hospital discharge in all patients.

Results. There were two deaths in each group. Cross-clamp time was longer in group M: 70 ± 19 minutes versus 51 ± 13 minutes in group S (p = 0.005). There were no statistically significant differences between groups M and S in pump time (95 ± 20 minutes versus 83 ± 19 minutes), extubation time (9.9 hours in both groups), chest drainage (479 ± 274 mL/ 24 hours versus 355 ± 159 mL/ 24 hours), transfusion requirements (27% in both groups), pain evaluation (1.34 ± 1.3 versus 2.15 ± 1.5), length of stay (6.2 ± 2.3 days versus 6.3 ± 2.5 days), and cosmetic appraisal. Forced vital capacity decreased 26% from preoperative reference values in group M and 33% in group S (p = not significant). Forced expiratory volume in 1 second decreased 22% and 35%, respectively (p = not significant).

Conclusions. This study has failed to prove the theoretical advantages of minimally invasive aortic valve replacement. With this technique, cross-clamp time is longer than with a median sternotomy.     

Hepatic biopsies and fluid drainages

Advances in cross-sectional imaging, as well as cytologic and histologic techniques, have led to an expansion of the radiologist's role in the diagnosis and treatment of various liver diseases. This article reviews the indications, contraindications, techniques, and results of hepatic biopsies and fluid drainage procedures performed with the aid of cross-sectional imaging.     

Five-year survival after resection of hepatic metastases from colorectal cancer in patients screened by positron emission tomography with F-18 fluorodeoxyglucose (FDG-PET)

OBJECTIVE: To report the first 5-year overall survival results in patients with colorectal carcinoma metastatic to the liver who have undergone hepatic resection after staging with [18F] fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET). SUMMARY BACKGROUND DATA: The 5-year overall survival after hepatic resection for colorectal cancer metastases without preoperative FDG-PET has been established in 19 studies (6070 patients). The median 5-year overall survival rate in these studies is 30% and has not improved over time. FDG-PET detects unsuspected tumor in 25% of patients considered to have resectable hepatic metastasis by conventional staging. METHODS: From March 1995 to June 2002, all patients having hepatic resection for colorectal cancer metastases had preoperative FDG-PET. A prospective database was maintained. RESULTS: One hundred patients (56 men, 44 women) were studied. Metastases were synchronous in 52, single in 63, unilateral in 78, and <5 cm in diameter in 60. Resections were major (>3 segments) in 75 and resection margins were > or = 1 cm in 52. Median follow up was 31 months, with 12 actual greater than 5-year survivors. There was 1 postoperative death. The actuarial 5-year overall survival was 58% (95% confidence interval, 46-72%). Primary tumor grade was the only prognostic variable significantly correlated with overall survival. CONCLUSIONS: Screening by FDG-PET is associated with excellent postresection 5-year overall survival for patients undergoing resection of hepatic metastases from colorectal cancer. FDG-PET appears to define a new cohort of patients in whom tumor grade is a very important prognostic variable.