Serial heart rate changes in rats inoculated by conjunctival instillation of Trypanosoma cruzi obtained from bug faeces

The cardiac effects of experimentally induced myocarditis, when the parasite is obtained from mouse blood, are well known. However, the consequences of the infection when the parasites are obtained from bug faeces are less well defined. In the present investigation, we have used the "Y" strain of Trypanosoma cruzi, which was maintained in Rhodnius prolixus by repeated passages in mice. The faeces of 30 infected bugs were collected, the number of parasites counted and 4,000 parasites inoculated by the conjunctival route in 60 rats. Twenty-nine other rats received faeces from noninfected bugs (sham-inoculated controls) and 40 were used as normal controls. The heart rate of the three groups of animals was recorded under general anesthesia with ether. The heart rate, at day 0 pre-inoculation, was similar in the three groups of animals (Controls: 379 ± 27 beats/min Mean ± SD; Sham-inoculated: 366 ± 31; Infected: 351 ± 29) (p> 0.05). In the infected animals, the mean heart rate began to increase significantly by day 12 following infection (375 ± 31), reaching the highest values between days 18 (390 ± 33) and 21 (403 ± 33) and returned to baseline by day 30 (359 ± 28) (p< 0.05). The heart rate changes were statistically different from those observed in the sham-inoculated controls and in the control animals. Therefore, these heart rate changes were provoked by the Trypanosoma cruzi-induced infection. Thus, it appears that irrespective of the source of the parasite and route of inoculation Trypanosoma cruziacute infection provokes a transient sinus tachycardia.

Serial High-Sensitivity Troponin T in Post-Primary Angioplasty Exercise Test

Abstract Background: The kinetics of high-sensitivity troponin T (hscTnT) release should be studied in different situations, including functional tests with transient ischemic abnormalities. Objective: To evaluate the release of hscTnT by serial measurements after exercise testing (ET), and to correlate hscTnT elevations with abnormalities suggestive of ischemia. Methods: Patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary angioplasty were referred for ET 3 months after infarction. Blood samples were collected to measure basal hscTnT immediately before (TnT0h), 2 (TnT2h), 5 (TnT5h), and 8 hours (TnT8h) after ET. The outcomes were peak hscTnT, TnT5h/TnT0h ratio, and the area under the blood concentration-time curve (AUC) for hscTnT levels. Log-transformation was performed on hscTnT values, and comparisons were assessed with the geometric mean ratio, along with their 95% confidence intervals. Statistical significance was assessed by analysis of covariance with no adjustment, and then, adjusted for TnT0h, age and sex, followed by additional variables (metabolic equivalents, maximum heart rate achieved, anterior wall STEMI, and creatinine clearance). Results: This study included 95 patients. The highest geometric means were observed at 5 hours (TnT5h). After adjustments, peak hscTnT, TnT5h/TnT0h and AUC were 59% (p = 0.002), 59% (p = 0.003) and 45% (p = 0.003) higher, respectively, in patients with an abnormal ET as compared to those with normal tests. Conclusion: Higher elevations of hscTnT may occur after an abnormal ET as compared to a normal ET in patients with STEMI.

Molecular diversity of serial Cryptococcus neoformans isolates from AIDS patients in the city of São Paulo, Brazil

Despite highly active anti-retroviral therapy, cryptococcal meningoencephalitis is the second most prevalent neurological disease in Brazilian AIDS patients, being frequently a defining condition with several episodes. As knowledge of Cryptococcus neoformans isolates in the same episode is critical for understanding why some patients develop several episodes, we investigated the genotype characteristics of C. neoformans isolates in two different situations. By pulsed field gel electrophoresis and random amplifield polymorphic DNA analysis, 54 isolates from 12 patients with AIDS and cryptococcosis were analyzed. Group 1 comprised 39 isolates from nine patients with a single episode and hospitalization. Group 2 comprised 15 isolates from three patients with two episodes and hospitalizations. Except for three patients from group 1 probably infected with a single C. neoformans isolate, the other nine patients probably were infected with multiple isolates selected in different collection periods, or the infecting isolate might have underwent mutation to adapt and survive the host immune system and/or the antifungal therapy. However, the three patients from group 2 presented genetic diversity among isolates collected in both hospitalizations, possibly having hosted the initial isolate in both periods. These data, emphasize that Cryptococcus diversity in infection can contribute to strategies of treatment and prevention of cryptococcosis.

Serial measurement of the circulating levels of tumour necrosis factor and its soluble receptors 1 and 2 for monitoring leprosy patients during multidrug treatment

Leprosy is an infectious and contagious spectral disease accompanied by a series of immunological events triggered by the host response to the aetiologic agent, Mycobacterium leprae . The induction and maintenance of the immune/inflammatory response in leprosy are linked to multiple cell interactions and soluble factors, primarily through the action of cytokines. The purpose of the present study was to evaluate the serum levels of tumour necrosis factor (TNF)-α and its soluble receptors (sTNF-R1 and sTNF-R2) in leprosy patients at different stages of multidrug treatment (MDT) in comparison with non-infected individuals and to determine their role as putative biomarkers of the severity of leprosy or the treatment response. ELISA was used to measure the levels of these molecules in 30 healthy controls and 37 leprosy patients at the time of diagnosis and during and after MDT. Our results showed increases in the serum levels of TNF-α and sTNF-R2 in infected individuals in comparison with controls. The levels of TNF-α, but not sTNF-R2, decreased with treatment. The current results corroborate previous reports of elevated serum levels of TNF-α in leprosy and suggest a role for sTNF-R2 in the control of this cytokine during MDT.

Serial QuantiFERON-TB Gold In-Tube assay and tuberculin skin test to diagnose latent tuberculosis in household Mexican contacts: conversion and reversion rates and associated factors using conventional and borderline zone definitions

A cohort of 123 adult contacts was followed for 18‐24 months (86 completed the follow-up) to compare conversion and reversion rates based on two serial measures of QuantiFERON (QFT) and tuberculin skin test (TST) (PPD from TUBERSOL, Aventis Pasteur, Canada) for diagnosing latent tuberculosis (TB) in household contacts of TB patients using conventional (C) and borderline zone (BZ) definitions. Questionnaires were used to obtain information regarding TB exposure, TB risk factors and socio-demographic data. QFT (IU/mL) conversion was defined as <0.35 to ≥0.35 (C) or <0.35 to >0.70 (BZ) and reversion was defined as ≥0.35 to <0.35 (C) or ≥0.35 to <0.20 (BZ); TST (mm) conversion was defined as <5 to ≥5 (C) or <5 to >10 (BZ) and reversion was defined as ≥5 to <5 (C). The QFT conversion and reversion rates were 10.5% and 7% with C and 8.1% and 4.7% with the BZ definitions, respectively. The TST rates were higher compared with QFT, especially with the C definitions (conversion 23.3%, reversion 9.3%). The QFT conversion and reversion rates were higher for TST ≥5; for TST, both rates were lower for QFT <0.35. No risk factors were associated with the probability of converting or reverting. The inconsistency and apparent randomness of serial testing is confusing and adds to the limitations of these tests and definitions to follow-up close TB contacts.

Sensitivity and specificity of parallel or serial serological testing for detection of canine Leishmania infection

In Brazil, human and canine visceral leishmaniasis (CVL) caused byLeishmania infantum has undergone urbanisation since 1980, constituting a public health problem, and serological tests are tools of choice for identifying infected dogs. Until recently, the Brazilian zoonoses control program recommended enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescence assays (IFA) as the screening and confirmatory methods, respectively, for the detection of canine infection. The purpose of this study was to estimate the accuracy of ELISA and IFA in parallel or serial combinations. The reference standard comprised the results of direct visualisation of parasites in histological sections, immunohistochemical test, or isolation of the parasite in culture. Samples from 98 cases and 1,327 noncases were included. Individually, both tests presented sensitivity of 91.8% and 90.8%, and specificity of 83.4 and 53.4%, for the ELISA and IFA, respectively. When tests were used in parallel combination, sensitivity attained 99.2%, while specificity dropped to 44.8%. When used in serial combination (ELISA followed by IFA), decreased sensitivity (83.3%) and increased specificity (92.5%) were observed. Serial testing approach improved specificity with moderate loss in sensitivity. This strategy could partially fulfill the needs of public health and dog owners for a more accurate diagnosis of CVL.

Whole-body MRI: comprehensive evaluation on a 48-channel 3T MRI system in less than 40 minutes. Preliminary results

OBJECTIVE: To evaluate a comprehensive MRI protocol that investigates for cancer, vascular disease, and degenerative/inflammatory disease from the head to the pelvis in less than 40 minutes on a new generation 48-channel 3T system. MATERIALS AND METHODS: All MR studies were performed on a 48-channel 3T MR scanner. A 20-channel head/neck coil, two 18-channel body arrays, and a 32-channel spine array were employed. A total of 4 healthy individuals were studied. The designed protocol included a combination of single-shot T2-weighted sequences, T1-weighted 3D gradient-echo pre- and post-gadolinium. All images were retrospectively evaluated by two radiologists independently for overall image quality. RESULTS: The image quality for cancer was rated as excellent in the liver, pancreas, kidneys, lungs, pelvic organs, and brain, and rated as fair in the colon and breast. For vascular diseases ratings were excellent in the aorta, major branch vessel origins, inferior vena cava, portal and hepatic veins, rated as good in pulmonary arteries, and as poor in the coronary arteries. For degenerative/inflammatory diseases ratings were excellent in the brain, liver and pancreas. The inter-observer agreement was excellent. CONCLUSION: A comprehensive and time efficient screening for important categories of disease processes may be achieved with high quality imaging in a new generation 48-channel 3T system.

Diagnostic performance of 3D TSE MRI versus 2D TSE MRI of the knee at 1.5 T, with prompt arthroscopic correlation, in the detection of meniscal and cruciate ligament tears

Abstract Objective: To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE) magnetic resonance imaging (MRI) technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE) protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods: Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results: For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively) and specificity (80% and 85%, respectively). For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively) and specificity (68% and 71%, respectively). In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively) and specificity (82% and 92%, respectively). There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion: The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition.

Localização de insulinoma pela injeção seletiva intra-arterial de cálcio

Insulinomas are rare endocrine tumors with an estimated incidence of 1(one) per million. Optimal therapy for all islet tumors of the pancreas is curative surgical resection. However, previous reports have show that, in the absence of preoparative localization, insulinoma may not be found intraoperatively in about 20% of patients. With current imaging technology, including serial computed tomography (CT), magnetic resonance imaging (MRI) and ultrasonography, localization of insulinomas less than 2cm remains inadequate. This case report shows that selective intraarterial calcium injection with hepatic venous sampling for insulin levels measured is a efficient technique for the localization of insulinomas.