Vancomycin serum concentrations in pediatric oncologic/hematologic intensive care patients

BackgroundUsual treatment regimens with vancomycin often fail to provide adequate serum levels in patients with severe infections.MethodsRetrospective analysis of vancomycin trough serum measurements. The following parameters were calculated by Bayesian analysis: vancomycin clearance, distribution volume, and peak estimated concentrations. The area under the concentration curve (AUC) (total daily dose/24 h clearance of vancomycin) was used to determine the effectiveness of treatment through the ratio of AUC/minimum inhibitory concentration (MIC) above 400, using MIC = 1 μg/mL, based on isolates of Staphylococci in cultures.ResultsSixty-one vancomycin trough measurements were analyzed in 31 patients. AUC/MIC > 400 was obtained in 34 out of 61 dosages (55.7%), but the mean vancomycin dose required to achieve these levels was 81 mg/kg/day. In cases where the usual doses were administered (40–60 mg/kg/day), AUC/MIC > 400 was obtained in nine out of 18 dosages (50%), in 13 patients. Trough serum concentrations above 15 mg/L presented a positive predictive value of 100% and a negative predictive value of 71% for AUC/MIC > 400.ConclusionHigher than usual vancomycin doses may be required to treat staphylococcal infections in children with oncologic/hematologic diseases. Since the best known predictor of efficacy is the AUC/MIC ratio, serum trough concentrations must be analyzed in conjunction with MICs of prevalent Staphylococci and pharmacokinetic tools such as Bayesian analysis.     

Antioxidant and Anticlastogenic Capacity of Prickly Pear Juice

Plants belonging to the genus Opuntia spp. are the most abundant of the Cactaceae family, grown throughout America and the Mediterranean central area. Its fruit, known as cactus pear or prickly pear, is an oval berry grouped in different colors. Some studies have shown its antioxidant activities which may help in preventing chronic pathologies such as diabetes. The purpose of the study was to evaluate the antioxidant capacity of three varieties of prickly pear juice (red-purple, white-green and yellow-orange) in five different concentrations (100, 250, 500, 750, and 1000 mg/mL) by DPPH (1,1-diphenyl-2-picrylhydrazyl radical) colorimetric method, selecting the best variety to determine its anticlastogenic potential against methyl methanesulfonate (MMS). The results indicate that the highest antioxidant was found in the juice of the prickly pear red-purple variety (PPRP), in all concentrations. Its anticlastogenic potential was therefore evaluated with a micronucleus assay. The experiment was run over two weeks. A negative control was included along with a positive control with MMS (40 mg/kg), a group of mice treated with PPRP (25 mL/kg), and three groups with PPRP (in doses of 25, 16.5 and 8.3 mL/kg) plus the mutagen. The PPRP was administered daily by oral gavage and the MMS was injected intraperitoneally five days prior to the end of the experiment. Blood samples were obtained at 0, 24, 48, 72 and 96 h in order to determine the frequency of micronucleated polychromatic erythrocytes (MNPE). The results indicated that PPRP is not a genotoxic agent, on the contrary, it may reduce the number of MNPE. In this regard, the PPRP showed an anticlastogenic effect directly proportional to its concentrations. Thus, the highest protection was obtained with a concentration of 25 mL/kg after 48 h of treatment.     

Lymph node non-Hodgkin's lymphoma incidentally discovered during a nephrectomy for renal cell carcinoma

We report the case of a left laparoscopic nephroureterectomy with the incidental discovery of a non-Hodgkin’s lymphoma in one of the lymph nodes of the renal hilum. A laparoscopic nephroureterectomy was decided on for a 64-year-old man. Renal cell carcinoma in the kidney and one lymph node of the renal hilum with non-Hodgkin’s lymphoma was found. Chemotherapy was not started for the lymphoma discovery. There are no signs of relapse after two years of follow up. Coexistence in the same patient is an extremely rare condition. We review the literature about this issue to clarify this association.     

Dynamic contrast-enhanced ultrasound with carbon dioxide microbubbles as adjunct to arteriography of liver tumors

Purpose The goal of the study is to evaluate utility of contrast enhanced ultrasound (US) with carbon dioxide microbubbles in evaluation of hepatic lesions.Methods Twenty eight patients with single or multiple t hepatic lesions (11 hepatocellular carcinoma, 8 hemangiomas, 5 metastases, 1 adenoma, 1 focal nodular hyperplasia, 2 regenerative nodules) were examined. US exam was performed during intraarterial injection of 10 ml of CO₂ through the same catheter employed for liver arteriography. The US exam was videotaped in its salient phases. Characteristics of enhancement were evaluated and correlated with histological findings or patient follow up.Results Sonographic angiography clearly demonstrated vascularization of the lesions. Hepatocellular carcinoma, hemangioma, metastases, focal nodular hyperplasia, and regenerative nodules had very characteristic patterns. The injection of CO₂ allowed detection of small additional nodules.Conclusion Sonographic angiography can improve characterization and staging of hepatic tumors. Low cost and the simplicity of the technique should encourage further experimentation.     

Prevalence of apical periodontitis detected in cone beam CT images of a Brazilian subpopulation

Objectives

The aim of this study was to determine the prevalence of apical periodontitis (AP) detected in cone beam CT (CBCT) images from a database.

Methods

CBCT images of 300 Brazilian patients were assessed. AP images were measured in three dimensions. Age, gender, number and location of total teeth in each patient were considered. AP location was considered according to tooth groups. The extent of AP was determined by the largest diameter in any of the three dimensions. Percentages and the χ² test were used for statistical analysis.

Results

AP was found in 51.4% of the patients and in 3.4% of the teeth. Higher prevalence of AP was found in 60- to 69-year-olds (73.1%) and in mandibular molars (5.9%) (p < 0.05). Inadequate endodontic treatment presented higher prevalence of AP (78.1%).

Conclusions

AP can be frequently found in CBCT examinations. The presence of AP has a significant association with patients'' age, and tooth type and condition. CBCT databases are useful for cross-sectional studies about AP prevalence in a population.     

Bowel Obstruction after Laparoscopic Roux-en-Y Gastric Bypass

Background: Bowel obstruction has been frequently reported after laparoscopic Roux-en-Y gastric bypass (LRYGBP). The aim of this study was to review our experience with bowel obstruction following LRYGBP, specifically examining its etiology and management and to strategize maneuvers to minimize this complication. Methods: We retrospectively reviewed the charts of 9 patients who developed postoperative bowel obstruction after LRYGBP. Each chart was reviewed for demographics, timing of bowel obstruction from the primary operation, etiology of obstruction, and management. Results: 9 of our initial 225 patients (4%) who underwent LRYGBP developed postoperative bowel obstruction. The mean age was 46 ± 12 years, with mean BMI 47 ± 9 kg/m². 6 patients developed early bowel obstruction, and 3 patients developed late bowel obstruction. The mean time interval for development of early bowel obstruction was 16 ±16 days. The causes for early bowel obstruction included narrowing of the jejunojenunostomy anastomosis (n=3), angulation of the Roux limb (n=2), and obstruction of the Roux limb at the level of the transverse mesocolon (n=1). The mean time interval for development of late bowel obstruction was 7.4 ± 0.5 months. The causes for late bowel obstruction included internal herniation (n=2) and adhesions (n=1). 6 of 9 bowel obstructions (66%) were considered technically related to the learning curve of the laparoscopic approach. Eight of the 9 patients required operative intervention, and 6 of the 8 reoperations were managed laparoscopically. Management included laparoscopic bypass of the jejunojejunostomy obstruction site (n=5), open reduction of internal hernia (n=2), and laparoscopic lysis of adhesion (n=1). Conclusions: Bowel obstruction is a frequent complication after LRYGBP, particularly during the learn ing curve of the laparoscopic approach. Specific measures should be instituted to minimize bowel obstruction after LRYGBP as most of these complications are considered technically preventable.