Two-step tuberculin skin test and booster phenomenon prevalence among Brazilian medical students

SETTING: Five medical schools in three cities in Rio de Janeiro State, Brazil, with different tuberculosis (TB) incidence rates. OBJECTIVE: To evaluate the prevalence of the booster phenomenon and its associated factors in a voting universally BCG-vaccinated TB-exposed population. DESIGN: A two-step tuberculin skin test (TST) was performed among undergraduate medical students. Boosting was defined as an induration >= 10 mm in the second TST (TST2), with an increase of at least 6 mm over the first TST (TST1). The association of boosting with independent variables was evaluated using multivariate analysis. RESULTS: Of the 764 participants (mean age 21.9 +/- 2.7 years), 672 (87.9%) had a BCG scar. The overall booster SUMMARY phenomenon prevalence was 8.4% (95%CI 6.5-10.6). Boosting was associated with TST1 reactions of 1-9 mm (aOR 2.5, 95%CI 1.04-5.9) and with BCG vaccination, mostly after infancy, i.e., after age two years (aOR 9.1, 95%,CI 1.2-70.7). CONCLUSION: The prevalence of the booster phenomenon was high. A two-step TST in young BCG-vaccinated populations, especially in those with TST1 reactions of 1-9 mm, can avoid misdiagnosis as a false conversion and potentially reduce unnecessary treatment for latent TB infection.

Knowledge and practices of medical students to prevent tuberculosis transmission in Rio de Janeiro, Brazil

Objectives. To describe knowledge, practices, and associated factors of medical students to prevent transmission of tuberculosis (TB) in five medical schools. Methods. Cross-sectional survey of undergraduate medical students in preclinical and in early and late clinical years. Information was obtained on sociodemographic profile, previous lectures on TB, knowledge about TB transmission, exposure to patients with active pulmonary TB, and use of respiratory protective masks. Results. Among 1 094 respondents, 575 (52.6%) correctly answered that coughing, speaking, and sneezing can transmit TB. Early [adjusted odds ratio = 4.0 (3.0, 5.5)] and late [adjusted odds ratio = 4.2 (3.1, 5.8)] clinical years were associated with correct answers, but having had previous lectures on TB was not. Among those who had previous lectures on TB, the rate of correct answers increased from 42.1% to 61.6%. Among 332 medical students who reported exposure to TB patients, 194 (58.4%) had not used protective masks. More years of clinical experience was associated with the use of masks [adjusted odds ratio = 2.9 (1.4, 6.1)], while knowledge was inversely associated with the use of masks [adjusted odds ratio = 0.4 (0.2, 0.6)]. Conclusions. Many medical students are not aware of the main routes of TB infection, and lectures on TB are not sufficient to change knowledge and practices. Regardless of knowledge about TB transmission, students engage in risky behaviors: more than two-thirds do not use a protective mask when examining an active TB case. We suggest innovative, effective active learning experiences to change this scenario.

From medical librarian to informacionist: semantic traces of their profiles and areas of performance

This literature review retakes the discussion of the profiles and competences of the information area professional, specifically, in the health field. Therefore, the aim here is to outline the new fields of performance for the informationist and the profiles required in the health context.

Advances in Imaging of Osteoarthritis and Cartilage

Osteoarthritis (OA) is the most frequent form of arthritis, with major implications for individual and public health care without effective treatment available. The field of joint imaging, and particularly magnetic resonance (MR) imaging, has evolved rapidly owing to technical advances and the application of these to the field of clinical research. Cartilage imaging certainly is at the forefront of these developments. In this review, the different aspects of OA imaging and cartilage assessment, with an emphasis on recent advances, will be presented. The current role of radiography, including advances in the technology for joint space width assessment, will be discussed. The development of various MR imaging techniques capable of facilitating assessment of cartilage morphology and the methods for evaluating the biochemical composition of cartilage will be presented. Advances in quantitative morphologic cartilage assessment and semiquantitative whole-organ assessment will be reviewed. Although MR imaging is the most important modality in imaging of OA and cartilage, others such as ultrasonography play a complementary role that will be discussed briefly.

Keyhole sign: how specific is it for the diagnosis of posterior urethral valves?

Objectives Posterior urethral valves (PUV) are the most common cause of renal impairment in boys during early childhood. Although antenatal suspicion of this pathology has become quite common in recent years, prenatal diagnosis remains challenging. The aim of this study was to evaluate the predictive value of different ultrasound criteria currently used to diagnose PUV. Methods We reviewed the antenatal and postnatal files of 54 male patients referred to our center from 2000 to 2006 after detection of fetal bilateral hydronephrosis. The following ultrasound criteria were evaluated in relation to the postnatal diagnosis of P U V: amniotic fluid volume, bladder wall thickness, bladder dilatation and the presence of the `keyhole sign`. Results Forty-two fetuses (77.8%) were suspected to have PUV on prenatal examination. Out of these, 29 (69.0%) had PUV confirmed postnatally. The sensitivity and specificity of the antenatal diagnosis of PUV were 94% and 43%, respectively. Increased bladder wall thickness and bladder dilatation were highly associated with the diagnosis of PUV (P < 0.001). However, a thick-walled bladder was observed in 39.1% and a dilated bladder in 47.8% of the infants with a postnatal diagnosis other than PUV. The presence of the keyhole sign was not found to predict a diagnosis of PUV (P = 0.27). Conclusion In this series the use of classical prenatal ultrasound signs to diagnose PUV showed high sensitivity but low specificity. The best diagnostic indicators were increased bladder wall thickness and dilatation of the bladder. The keyhole sign was not found to be a reliable predictor of PUV. Copyright (C) 2009 ISUOG. Published by John Wiley & Sons, Ltd.

Lower Extremities Magnetic Resonance Angiography With Blood Pressure Cuff Compression: Quantitative Dynamic Analysis

Purpose: To quantitatively evaluate changes induced by the application of a femoral blood-pressure cuff (BPC) on run-off magnetic resonance angiography (MRA). which is a method generally previously proposed to reduce venous contamination in the leg. Materials and Methods: This study was Health Insurance Portability and Accountability Act (HIPAA)- and Institutional Review Board (IRB)-compliant, We used time-resolved gradient-echo gadolinium (Gd)-enhanced MRA to measure BPC effects on arterial, venous, and soft-tissue enhancement. Seven healthy volunteers (six men) were studied with the BPC applied at the mid-femoral level unilaterally using a 1.5T MR system after intravenous injection of Gd-BOPTA. Different statistical tools were used such as the Wilcoxon signed rank test and a cubic smoothing spline fit. Results: We found that BPC application induces delayed venous filling (as previously described), but also induces significant decreases in arterial inflow, arterial enhancement, vascular-soft tissue contrast, and delayed peak enhancement (which have not been previously measured). Conclusion: The potential benefits from using a BPC for run-off MRA must be balanced against the potential pitfalls, elucidated by our findings.

Lower uterine segment thickness measurement in pregnant women with previous Cesarean section: reliability analysis using two- and three-dimensional transabdominal and transvaginal ultrasound

Objective To evaluate the reliability of two- and three-dimensional ultrasonographic measurement of the thickness of the lower uterine segment (LUS) in pregnant women by transvaginal and transabdominal approaches. Methods This was a study of 30 pregnant women who bad bad at least one previous Cesarean section and were between 36 and 39 weeks` gestation, with singleton pregnancies in cephalic presentation. Sonographic examinations were performed by two observers using both 4-7-MHz transabdominal and 5-8-MHz transvaginal volumetric probes. LUS measurements were performed using two- and three-dimensional ultrasound, evaluating the entire LUS thickness transabdominally and the LUS muscular thickness transvaginally. Each observer measured the LUS four times by each method. Reliability was analyzed by comparing the mean of the absolute differences, the intraclass correlation coefficients, the 95% limits of agreement and the proportion of differences <1 mm. Results Transvaginal ultrasound provided greater reliability in LUS measurements than did transabdominal ultrasound. The use of three-dimensional ultrasound improved significantly the reliability of the LUS muscular thickness measurement obtained transvaginally. Conclusions Ultrasonographic measurement of the LUS muscular thickness transvaginally appears more reliable than does that of the entire LUS thickness transabdominally. The use of three-dimensional ultrasound should be considered to improve measurement reliability. Copyright (c) 2009 ISUOG. Published by John Wiley & Sons, Ltd.

Magnetic Resonance Imaging in Knee Osteoarthritis Research: Semiquantitative and Compositional Assessment

Semiquantitative assessment of the knee by expert magnetic resonance imaging readers is a powerful research tool for understanding the natural history of osteoarthritis (OA). Several reliable semiquantitative scoring systems have been applied to large observational cross-sectional and longitudinal epidemiologic studies and interventional clinical trials. Such evaluations have enabled understanding of the relevance of disease in structures within the knee joint to explain pain and progression of OA. Compositional imaging of cartilage has added to our ability to detect early degeneration before morphologic changes are present, which may help to prevent the permanent morphologic changes commonly seen in knee OA.

Treatment of Brain Arteriovenous Malformations by Double Arterial Catheterization with Simultaneous Injection of Onyx: Retrospective Series of 17 Patients

BACKGROUND AND PURPOSE: The use of Onyx in the treatment of intracranial AVMs has increased the cure rate of endovascular embolization compared with the use of liquid adhesive agents. Inadvertent occlusion of the draining veins before the complete exclusion of the nidus constitutes a major risk of bleeding. We report a case series using the technique of double simultaneous arterial catheterization as an approach to achieve the complete, exclusion of the nidus before reaching the venous drainage, through a more controlled hemodynamic filling. MATERIALS AND METHODS: Between April 2008 and November 2009, 17 patients with brain AVMs were treated by the DACT. The mean age of the patients was 32.7 years (range, 6-54 years), with 9 females and 8 males. The clinical onset was characterized by intracranial hemorrhage in 8 patients and by seizures in 7. The size of the AVMs ranged from 13 to 54 mm (average, 26.2 mm). The DACT was always used with the objective of curing the AVM. RESULTS: All 17 patients completed the EVT. The average number of sessions conducted was 1.4 (range, 1-3 sessions), with the average injection amount of 6.9 mL of Onyx (range, 2-25.2 mL). Sixteen AVMs (94.1%) were angiographically cured by embolization. Clinical complications occurred in 2 patients (11.7%); 1 of these was permanent (5.9%). No deaths were registered. CONCLUSIONS: This preliminary series shows that the DACT presents satisfactory results when used with curative intent.

Articular Cartilage in the Knee: Current MR Imaging Techniques and Applications in Clinical Practice and Research

Magnetic resonance (MR) imaging is the most important imaging modality for the evaluation of traumatic or degenerative cartilaginous lesions in the knee. It is a powerful noninvasive tool for detecting such lesions and monitoring the effects of pharmacologic and surgical therapy. The specific MR imaging techniques used for these purposes can be divided into two broad categories according to their usefulness for morphologic or compositional evaluation. To assess the structure of knee cartilage, standard spin-echo (SE) and gradient-recalled echo (GRE) sequences, fast SE sequences, and three-dimensional SE and GRE sequences are available. These techniques allow the detection of morphologic defects in the articular cartilage of the knee and are commonly used in research for semiquantitative and quantitative assessments of cartilage. To evaluate the collagen network and proteoglycan content in the knee cartilage matrix, compositional assessment techniques such as T2 mapping, delayed gadolinium-enhanced MR imaging of cartilage (or dGEMRIC), T1 rho imaging, sodium imaging, and diffusion-weighted imaging are available. These techniques may be used in various combinations and at various magnetic field strengths in clinical and research settings to improve the characterization of changes in cartilage. (C)RSNA, 2011 , radiographics.rsna.org

Magnetic resonance imaging quantification of regional cerebral blood flow and cerebrovascular reactivity to carbon dioxide in normotensive and hypertensive rats

Hypertension afflicts 25% of the general population and over 50% of the elderly. In the present work, arterial spin labeling MRI was used to non-invasively quantify regional cerebral blood flow (CBE), cerebrovascular resistance and CO(2) reactivity in spontaneously hypertensive rats (SHR) and in normotensive Wistar Kyoto rats (WKY), at two different ages (3 months and 10 months) and under the effects of two anesthetics, alpha-chloralose and 2% isoflurane (1.5 MAC). Repeated CBE measurements were highly consistent, differing by less than 10% and 18% within and across animals, respectively. Under alpha-chloralose, whole brain CBE at normocapnia did not differ between groups (young WKY: 61 3 ml/100 g/min; adult WKY: 62 +/- 4 ml/100 g/min; young SHR: 70 +/- 9 ml/100 g/min: adult SHR: 69 8 ml/100 g/min), indicating normal cerebral autoregulation in SHR. At hypercapnia, CBE values increased significantly, and a linear relationship between CBE and PaCO(2) levels was observed. In contrast, 2% isoflurane impaired cerebral autoregulation. Whole brain CBE in SHR was significantly higher than in WKY rats at normocapnia (young SHR: 139 +/- 25 ml/100 g/min; adult SHR: 104 +/- 23 ml/100 g/min; young WKY: 55 +/- 9 ml/100 g/min; adult WKY: 71 +/- 19 ml/100 g/min). CBE values increased significantly with increasing CO(2): however, there was a clear saturation of CBF at PaCO(2) levels greater than 70 mm Hg in both young and adult rats, regardless of absolute CBE values, suggesting that isoflurane interferes with the vasoclilatory mechanisms of CO(2). This behavior was observed for both cortical and subcortical structures. Under either anesthetic, CO(2) reactivity values in adult SHR were decreased, confirming that hypertension, when combined with age, increases cerebrovascular resistance and reduces cerebrovascular compliance. Published by Elsevier Inc.

LOW-INTENSITY ULTRASOUND APPLICATION IN DISTAL RADIUS METAPHYSEAL BONE DEFECTS OF DOGS

We assessed the repair of transverse, 3-mm wide bone gaps created at the distal radius in 28 dogs that were randomly divided into two 14-animal groups; one was the control group and the other received a daily, 20-min application of low-intensity pulsed ultrasound for 100 days. Sequential radiographs, histomorphometrics, bone fluorescent histology and bone vascularity assessments found that all animals from both groups obtained a stage of hypertrophic-type nonunion with fibrocartilage tissue formation throughout the region of osteotomy. However, treated animals exhibited areas of endochondral ossification within the fibrocartilage region. There was no difference in type of vascularity or the newly formed bone process obtained by tetracycline labeling. Application of low-intensity ultrasound was not capable of significantly changing the reparative process and it may not be sufficiently powerful to overcome a combination of local deleterious effects on bone healing, created by gapping, excessive motion and periosteal resection. (E-mail: jbvolpon@fmrp.usp.br) (C) 2010 World Federation for Ultrasound in Medicine & Biology.

Subchondral Cystlike Lesions Develop Longitudinally in Areas of Bone Marrow Edema-like Lesions in Patients with or at Risk for Knee Osteoarthritis: Detection with MR Imaging-The MOST Study

Purpose: To assess the association of prevalent bone marrow edema-like lesions (BMLs) and full-thickness cartilage loss with incident subchondral cyst-like lesions (SCs) in the knee to evaluate the bone contusion versus synovial fluid intrusion theories of SC formation. Materials and Methods: The Multicenter Osteoarthritis study is a longitudinal study of individuals who have or are at risk for knee osteoarthritis. The HIPAA-compliant protocol was approved by the institutional review boards of all participating centers, and written informed consent was obtained from all participants. Magnetic resonance images were acquired at baseline and 30-month follow-up and read semiquantitatively by using the Whole-Organ Magnetic Resonance Imaging Score system. The tibiofemoral and patellofemoral joints were subdivided into 14 subregions. BMLs and SCs were scored from 0 to 3. Cartilage morphology was scored from 0 to 6. The association of prevalent BMLs and full-thickness cartilage loss with incident SCs in the same subregion was assessed by using logistic regression with mutual adjustment for both predictors. Results: A total of 1283 knees were included. After adjustment for full-thickness cartilage loss, prevalent BMLs showed a strong and significant association with incident SCs in the same subregion, with an odds ratio of 12.9 (95% confidence interval [CI]: 8.9, 18.6). After adjustment for BMLs, prevalent full-thickness cartilage loss showed a significant but much less important association with incident SCs in the same subregion (odds ratio, 1.4; 95% CI: 1.0, 2.0). There was no apparent relationship between severity of full-thickness cartilage loss at baseline and incident SCs. Conclusion: Prevalent BMLs strongly predict incident SCs in the same subregion, even after adjustment for full-thickness cartilage loss, which supports the bone contusion theory of SC formation. (C) RSNA, 2010