Infection by Trypanosoma vivax in goats and sheep in the Brazilian semiarid region: From acute disease outbreak to chronic cryptic infection

A study was undertaken to investigate the role of Trypanosoma vivax in sheep and goat mortality and abortions in the Brazilian semiarid region, where outbreaks Had been previously reported in bovines. For this purpose, 177 goats and 248 sheep (20% of herds) were randomly sampled on four farms in the State of Paraiba in May and October 2008. The animals were screened for trypanosomes by the buffy coat technique (BCT) and PCR. Infected animals, similar to 25% in both surveys, manifested apathy, pale mucous membranes, enlarged lymph nodes, weakness, weight loss, opacity of the cornea, blindness and abortion. However, the animals with acute and severe disease showing the highest levels of parasitemia and fever, which many times resulted in death, were only detected in the first survey. These severely diseased animals exhibited progressive weight loss and had the smallest packed cell volume (PCV) values. During survey 2, done in October 2008 on the same farms, only animals with low parasitemia and normal temperatures, PCV values and body weights were detected. Therefore, animals that spontaneously recovered from acute infection developed chronic and asymptomatic disease. This finding demonstrated for the first time that sheep and goats, which are the most important livestock in the semiarid region of Brazil, may be severely injured by T. vivax infection and also play a role as asymptomatic carriers and important sources of T. vivax to ruminants in general. Published by Elsevier B.V.

Monitoring of Group C Rotavirus in Children With Acute Gastroenteritis in Brazil: An Emergent Epidemiological Issue After Rotavirus Vaccine?

Group C rotavirus (GpCRV) has a worldwide distribution; however, its epidemiology and ecology are still unclear. Evidence for a possible zoonotic role has been postulated recently for Brazilian children strains. The aim of this study was to monitor GpCRV in children <= 15 years with acute gastroenteritis during the 2007-2010 national Brazilian rotavirus surveillance, and to undertake the molecular characterization of the major VP6 capsid protein. A total of 3,019 fecal samples were first screened for Group A rotavirus (GpARV). A total of 2,205 GpARV ELISA negative samples were tested further for the presence of GpCRV by SDS-PAGE, electronic microscopy, and RT-PCR for the VP6 gene. The genetic diversity of GpCRV was carried out by sequencing the VP6 gene. GpARV and GpCRV infections were detected in 24.6% (742/3,019) and 0.3% (8/3,019), respectively. The GpCRV detection rate increased from 0.2% (1/422) in 2007 to 1% (7/708) in 2008, and GpCRV cases were not detected in 2009 and 2010. The phylogenetic analysis indicated that the strains belonged to the human lineage, and showed a genetic relationship with the GpCRV strain from Japan isolated in 2009. None of the study sequences was related closely to animal GpCRV strains. This study provides further evidence that GpCRV is a minor cause of acute childhood gastroenteritis in Brazil, and does not suggest that GpCRV may assume epidemiological importance in the future, even after the introduction of a GpARV vaccine. In addition, the molecular analyses of the GpCRV samples in this study do not support the zoonotic hypothesis. J. Med. Virol. 83: 1631-1636, 2011. (C) 2011 Wiley-Liss, Inc.

Microlithiasis of the gallbladder: role of endoscopic ultrasonography in patients with idiopathic acute pancreatitis

OBJECTIVES: Causes may be found in most cases of acute pancreatitis, however no etiology is found by clinical, biological and imaging investigations in 30% of these cases. Our objective was to evaluate results from endoscopic ultrasonography (EUS) for diagnosis of gallbladder microlithiasis in patients with unexplained (idiopathic) acute pancreatitis. METHODS: Thirty-six consecutive non-alcoholic patients with diagnoses of acute pancreatitis were studied over a five-year period. None of them showed signs of gallstones on transabdominal ultrasound or tomography. We performed EUS within one week of diagnosing acute pancreatitis. Diagnosis of gallbladder microlithiasis on EUS was based upon findings of hyperechoic signals of 0.5-3.0 mm, with or without acoustic shadowing. All patients (36 cases) underwent cholecystectomy, in accordance with indication from the attending physician or based upon EUS diagnosis. RESULTS: Twenty-seven patients (75%) had microlithiasis confirmed by histology and nine did not (25%). EUS findings were positive in twenty-five. Two patients had acute cholecystitis diagnosed at EUS that was confirmed by surgical and histological findings. In two patients, EUS showed cholesterolosis and pathological analysis disclosed stones not detected by EUS. EUS diagnosed microlithiasis in four cases not confirmed by surgical treatment. In our study, sensitivity, specificity and positive and negative predictive values to identify gallbladder microlithiasis (with 95% confidence interval) were 92.6% (74.2-98.7%), 55.6% (22.7-84.7%), 86.2% (67.4-95.5%) and 71.4% (30.3-94.9%), respectively. Overall EUS accuracy was 83.2%. CONCLUSIONS: EUS is a very reliable procedure to diagnose gallbladder microlithiasis and should be used for the management of patients with unexplained acute pancreatitis. This procedure should be part of advanced endoscopic evaluation.

Cardioprotective effect of ornitho-kinin in an anesthetized, open-chest chicken model of acute coronary occlusion

The generation of bradykinin (BK; Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) in blood and kallidin (Lys-BK) in tissues by the action of the kallikrein-kinin system has received little attention in non-mammalian vertebrates. In mammals, kallidin can be generated by the coronary endothelium and myocytes in response to ischemia, mediating cardioprotective events. The plasma of birds lacks two key components of the kallikrein-kinin system: the low molecular weight kininogen and a prekallikrein activator analogous to mammalian factor XII, but treatment with bovine plasma kallikrein generates ornitho-kinin [Thr6,Leu8]-BK. The possible cardioprotective effect of ornitho-kinin infusion was investigated in an anesthetized, open-chest chicken model of acute coronary occlusion. A branch of the left main coronary artery was reversibly ligated to produce ischemia followed by reperfusion, after which the degree of myocardial necrosis (infarct size as a percent of area at risk) was assessed by tetrazolium staining. The iv injection of a low dose of ornitho-kinin (4 µg/kg) reduced mean arterial pressure from 88 ± 12 to 42 ± 7 mmHg and increased heart rate from 335 ± 38 to 402 ± 45 bpm (N = 5). The size of the infarct was reduced by pretreatment with ornitho-kinin (500 µg/kg infused over a period of 5 min) from 35 ± 3 to 10 ± 2% of the area at risk. These results suggest that the physiological role of the kallikrein-kinin system is preserved in this animal model in spite of the absence of two key components, i.e., low molecular weight kininogen and factor XII.

The anticancer drug tamoxifen is active against Trypanosoma cruzi in vitro but ineffective in the treatment of the acute phase of Chagas disease in mice

The activity of the antineoplastic drug tamoxifen was evaluated against Trypanosoma cruzi. In vitro activity was determined against epimastigote, trypomastigote and amastigote forms of CL14, Y and Y benznidazole resistant T. cruzi strains. Regardless of the strain used, the drug was active against all life-cycle stages of the parasite with a half maximal effective concentration ranging from 0.7-17.9 µM. Two experimental models of acute Chagas disease were used to evaluate the in vivo efficacy of treatment with tamoxifen. No differences in parasitemia and mortality were observed between control mock-treated and tamoxifen-treated mice.

Aerobic and anaerobic metabolism for the zebrafish, Danio rerio, reared under normoxic and hypoxic conditions and exposed to acute hypoxia during development

In order to verify the influence of chronic and acute ambient oxygen levels from egg to adult stage of the zebrafish, in vivo oxygen consumption (MO2), critical tensions of oxygen (Pcrit), heart rate (fH) and total body lactate concentration (Lc) were determined for Danio rerio (Hamilton, 1822) raised at 28 °C under normoxic (7.5 mgO2.L-1 or 80 mm.Hg-1) and hypoxic conditions (4.3 mgO2.L-1) and exposed to acute hypoxia during different developmental stages. Our findings confirmed that very early stages do not respond effectively to ambient acute hypoxia. However, after the stage corresponding to the age of 30 days, D. rerio was able to respond to acute hypoxia through effective physiological mechanisms involving aerobic and anaerobic metabolism. Such responses were more efficient for the fishes reared under hypoxia which showed that D. rerio survival capability increased during acclimation to mild hypoxia. Measurements of body mass and length showed that moderate hypoxia did not affect growth significantly until the fish reached the stage of 60 days. Moreover, a growth delay was verified for the hypoxic-reared animals. Also, the D. rerio eggs-to-larvae survival varied from 87.7 to 62.4% in animals reared under normoxia and mild hypoxia, respectively. However, the surviving animals raised under moderated hypoxia showed a better aptitude to regulate aerobic and anaerobic capacities when exposed to acute hypoxia.

TiO2-Photocatalyzed degradation of phenol in saline media in an annular reactor: hydrodynamics, lumped kinetics, intermediates, and acute toxicity

The photocatalytic degradation of phenol in aqueous suspensions of TiO2 under different salt concentrations in an annular reactor has been investigated. In all cases, complete removal of phenol and mineralization degrees above 90% were achieved. The reactor operational parameters were optimized and its hydrodynamics characterized in order to couple mass balance equations with kinetic ones. The photodegradation of the organics followed a Langmuir-Hinshelwood-Hougen-Watson lumped kinetics. From GC/MS analyses, several intermediates formed during oxidation have been identified. The main ones were catechol, hydroquinone, and 3-phenyl-2-propenal, in this order. The formation of negligible concentrations of 4-chlorophenol was observed only in high salinity medium. Acute toxicity was determined by using Artemia sp. as the test organism, which indicated that intermediate products were all less toxic than phenol and a significant abatement of the overall toxicity was accomplished, regardless of the salt concentration.

Magnetic fields and acute lymphoblastic leukemia in children: a systematic review of case-control studies

Leukemia incidence in children has increased worldwide in recent decades, particularly due to the rise in acute lymphoblastic leukemia. Studies have associated exposure to non-ionizing radiation generated by low frequency magnetic fields with childhood leukemia. The current article reviews the case-control studies published on this subject. Of 152 articles tracked in different databases, ten studies from North America, Asia, and Europe met the defined selection criteria, with patients diagnosed from 1960 to 2004. Methodological limitations were observed in these articles, including difficulties with the procedures for assessing exposure. An association may exist between exposure to low frequency magnetic fields and acute lymphoblastic leukemia in children, but this association is weak, preventing the observation of consistency in the findings. Future studies from a wider range of geographic regions should focus on the analysis of acute lymphoblastic leukemia, which is the subtype with the greatest impact on the increasing overall incidence of childhood leukemia.

Simplified flow cytometric assay to detect minimal residual disease in childhood with acute lymphoblastic leukemia

The detection of minimal residual disease (MRD) is an important prognostic factor in childhood acute lymphoblastic leukemia (ALL) providing crucial information on the response to treatment and risk of relapse. However, the high cost of these techniques restricts their use in countries with limited resources. Thus, we prospectively studied the use of flow cytometry (FC) with a simplified 3-color assay and a limited antibody panel to detect MRD in the bone marrow (BM) and peripheral blood (PB) of children with ALL. BM and PB samples from 40 children with ALL were analyzed on days (d) 14 and 28 during induction and in weeks 24-30 of maintenance therapy. Detectable MRD was defined as > 0.01% cells expressing the aberrant immunophenotype as characterized at diagnosis among total events in the sample. A total of 87% of the patients had an aberrant immunophenotype at diagnosis. On d14, 56% of the BM and 43% of the PB samples had detectable MRD. On d28, this decreased to 45% and 31%, respectively. The percentage of cells with the aberrant phenotype was similar in both BM and PB in T-ALL but about 10 times higher in the BM of patients with B-cell-precursor ALL. Moreover, MRD was detected in the BM of patients in complete morphological remission (44% on d14 and 39% on d28). MRD was not significantly associated to gender, age, initial white blood cell count or cell lineage. This FC assay is feasible, affordable and readily applicable to detect MRD in centers with limited resources.

Emergence and disappearance of a virulent clone of Haemophilus influenzae biogroup aegyptius, cause of Brazilian Purpuric Fever

Summary: In 1984, children presented to the emergency department of a hospital in the small town of Promissão, São Paulo State, Brazil, with an acute febrile illness that rapidly progressed to death. Local clinicians and public health officials recognized that these children had an unusual illness, which led to outbreak investigations conducted by Brazilian health officials in collaboration with the U.S. Centers for Disease Control and Prevention. The studies that followed are an excellent example of the coordinated and parallel studies that are used to investigate outbreaks of a new disease, which became known as Brazilian purpuric fever (BPF). In the first outbreak investigation, a case-control study confirmed an association between BPF and antecedent conjunctivitis but the etiology of the disease could not be determined. In a subsequent outbreak, children with BPF were found to have bacteremia caused by Haemophilus influenzae biogroup aegyptius (H. aegyptius), an organism previously known mainly to cause self-limited purulent conjunctivitis. Molecular characterization of blood and other isolates demonstrated the clonal nature of the H. aegyptius strains that caused BPF, which were genetically distant from the diverse strains that cause only conjunctivitis. This led to an intense effort to identify the factors causing the unusual invasiveness of the BPF clone, which has yet to definitively identify the virulence factor or factors involved. After a series of outbreaks and sporadic cases through 1993, no additional cases of BPF have been reported

The acute effects of varying strength exercises bouts on 5km running

This study investigated if there were acute interference effects of strength exercises on subsequent continuous and intermittent 5Km aerobic exercises. Eleven physically active males (23.1 +/- 3.1 yrs, 1.75 +/- 0.07 m, 70.5 +/- 8.8 kg, and 58.2 +/- 8.3 VO(2)max) performed the following experimental sessions: A) 5 sets of 5 RM on the leg press followed by a 5km run performed continuously (average velocity of the first and second ventilatory thresholds, nu Delta 50), B) 5 sets of 5 RM on the leg press followed by a 5km run performed intermittently (1 min run at the nu VO(2)max : 1 min of rest); C) 2 sets of 15 RM on the leg press followed by a 5km continuous run; and D) 2 sets of 15 RM on the leg press followed by a 5km intermittent run. Heart rate, blood lactate concentration, rate of perceived exertion, and VO(2) at the first and the fifth km were considered for statistical purposes. There were no significant effects of both strength bouts on any of the variables associated with endurance performance (p > 0.05). It seems that both maximum and strength endurance bouts do not acutely impair aerobic performance.

First Description of a Cluster of Acute/Subacute Paracoccidioidomycosis Cases and Its Association with a Climatic Anomaly

Background: Identifying clusters of acute paracoccidioidomycosis cases could potentially help in identifying the environmental factors that influence the incidence of this mycosis. However, unlike other endemic mycoses, there are no published reports of clusters of paracoccidioidomycosis. Methodology/Principal Findings: A retrospective cluster detection test was applied to verify if an excess of acute form (AF) paracoccidioidomycosis cases in time and/or space occurred in Botucatu, an endemic area in Sao Paulo State. The scan-test SaTScan v7.0.3 was set to find clusters for the maximum temporal period of 1 year. The temporal test indicated a significant cluster in 1985 (P<0.005). This cluster comprised 10 cases, although 2.19 were expected for this year in this area. Age and clinical presentation of these cases were typical of AF paracccidioidomycosis. The space-time test confirmed the temporal cluster in 1985 and showed the localities where the risk was higher in that year. The cluster suggests that some particularities took place in the antecedent years in those localities. Analysis of climate variables showed that soil water storage was atypically high in 1982/83 (similar to 2.11/2.5 SD above mean), and the absolute air humidity in 1984, the year preceding the cluster, was much higher than normal (similar to 1.6 SD above mean), conditions that may have favored, respectively, antecedent fungal growth in the soil and conidia liberation in 1984, the probable year of exposure. These climatic anomalies in this area was due to the 1982/83 El Nino event, the strongest in the last 50 years. Conclusions/Significance: We describe the first cluster of AF paracoccidioidomycosis, which was potentially linked to a climatic anomaly caused by the 1982/83 El Nino Southern Oscillation. This finding is important because it may help to clarify the conditions that favor Paracoccidioides brasiliensis survival and growth in the environment and that enhance human exposure, thus allowing the development of preventive measures.

Loxosceles gaucho Venom-Induced Acute Kidney Injury - In Vivo and In Vitro Studies

Background: Accidents caused by Loxosceles spider may cause severe systemic reactions, including acute kidney injury (AKI). There are few experimental studies assessing Loxosceles venom effects on kidney function in vivo. Methodology/Principal Findings: In order to test Loxosceles gaucho venom (LV) nephrotoxicity and to assess some of the possible mechanisms of renal injury, rats were studied up to 60 minutes after LV 0.24 mg/kg or saline IV injection (control). LV caused a sharp and significant drop in glomerular filtration rate, renal blood flow and urinary output and increased renal vascular resistance, without changing blood pressure. Venom infusion increased significantly serum creatine kinase and aspartate aminotransferase. In the LV group renal histology analysis found acute epithelial tubular cells degenerative changes, presence of cell debris and detached epithelial cells in tubular lumen without glomerular or vascular changes. Immunohistochemistry disclosed renal deposition of myoglobin and hemoglobin. LV did not cause injury to a suspension of fresh proximal tubules isolated from rats. Conclusions/Significance: Loxosceles gaucho venom injection caused early AKI, which occurred without blood pressure variation. Changes in glomerular function occurred likely due to renal vasoconstriction and rhabdomyolysis. Direct nephrotoxicity could not be demonstrated in vitro. The development of a consistent model of Loxosceles venom-induced AKI and a better understanding of the mechanisms involved in the renal injury may allow more efficient ways to prevent or attenuate the systemic injury after Loxosceles bite.

Spatio-Temporal Tracking and Phylodynamics of an Urban Dengue 3 Outbreak in Sao Paulo, Brazil

The dengue virus has a single-stranded positive-sense RNA genome of similar to 10.700 nucleotides with a single open reading frame that encodes three structural (C, prM, and E) and seven nonstructural (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) proteins. It possesses four antigenically distinct serotypes (DENV 1-4). Many phylogenetic studies address particularities of the different serotypes using convenience samples that are not conducive to a spatio-temporal analysis in a single urban setting. We describe the pattern of spread of distinct lineages of DENV-3 circulating in Sao Jose do Rio Preto, Brazil, during 2006. Blood samples from patients presenting dengue-like symptoms were collected for DENV testing. We performed M-N-PCR using primers based on NS5 for virus detection and identification. The fragments were purified from PCR mixtures and sequenced. The positive dengue cases were geo-coded. To type the sequenced samples, 52 reference sequences were aligned. The dataset generated was used for iterative phylogenetic reconstruction with the maximum likelihood criterion. The best demographic model, the rate of growth, rate of evolutionary change, and Time to Most Recent Common Ancestor (TMRCA) were estimated. The basic reproductive rate during the epidemics was estimated. We obtained sequences from 82 patients among 174 blood samples. We were able to geo-code 46 sequences. The alignment generated a 399-nucleotide-long dataset with 134 taxa. The phylogenetic analysis indicated that all samples were of DENV-3 and related to strains circulating on the isle of Martinique in 2000-2001. Sixty DENV-3 from Sao Jose do Rio Preto formed a monophyletic group (lineage 1), closely related to the remaining 22 isolates (lineage 2). We assumed that these lineages appeared before 2006 in different occasions. By transforming the inferred exponential growth rates into the basic reproductive rate, we obtained values for lineage 1 of R(0) = 1.53 and values for lineage 2 of R(0) = 1.13. Under the exponential model, TMRCA of lineage 1 dated 1 year and lineage 2 dated 3.4 years before the last sampling. The possibility of inferring the spatio-temporal dynamics from genetic data has been generally little explored, and it may shed light on DENV circulation. The use of both geographic and temporally structured phylogenetic data provided a detailed view on the spread of at least two dengue viral strains in a populated urban area.