In vitro and in vivo experimental models for drug screening and development for Chagas disease

Chagas disease, a neglected illness, affects nearly 12-14 million people in endemic areas of Latin America. Although the occurrence of acute cases sharply has declined due to Southern Cone Initiative efforts to control vector transmission, there still remain serious challenges, including the maintenance of sustainable public policies for Chagas disease control and the urgent need for better drugs to treat chagasic patients. Since the introduction of benznidazole and nifurtimox approximately 40 years ago, many natural and synthetic compounds have been assayed against Trypanosoma cruzi, yet only a few compounds have advanced to clinical trials. This reflects, at least in part, the lack of consensus regarding appropriate in vitro and in vivo screening protocols as well as the lack of biomarkers for treating parasitaemia. The development of more effective drugs requires (i) the identification and validation of parasite targets, (ii) compounds to be screened against the targets or the whole parasite and (iii) a panel of minimum standardised procedures to advance leading compounds to clinical trials. This third aim was the topic of the workshop entitled Experimental Models in Drug Screening and Development for Chagas Disease, held in Rio de Janeiro, Brazil, on the 25th and 26th of November 2008 by the Fiocruz Program for Research and Technological Development on Chagas Disease and Drugs for Neglected Diseases Initiative. During the meeting, the minimum steps, requirements and decision gates for the determination of the efficacy of novel drugs for T. cruzi control were evaluated by interdisciplinary experts and an in vitro and in vivo flowchart was designed to serve as a general and standardised protocol for screening potential drugs for the treatment of Chagas disease.

Sinusite aiguë: prise en charge en médecine de premier recours [Acute sinusitis]

Les infections des voies aériennes supérieures sont parmi les motifs de consultation les plus fréquents en médecine de premier recours. Lorsque la localisation est principalement rhinosinusienne, la cause est en général virale. Nous passons en revue dans cet article les conditions permettant de suspecter une origine bactérienne avec comme question centrale les critères pour l'instauration d'un traitement antibiotique. La place des examens paracliniques dans la stratégie diagnostique est discutée et en particulier celle de la radiographie standard. Rhino-sinusitis is one of the most complaint in ambulatory clinic sitting and nasal obstruction. This diagnosis is however difficult and general practitioners might overdiagnose acute bacterial sinusitis. Most imaging is not useful in determining sinusitis. Acute sinusitis is very often a self-limiting disease. Antibiotics should be prescribed only after one week of symptoms' duration and in case of the presence of two additional criteria: pain and purulent nasal discharge with nasal obstruction

Antibody reactivity against potato apyrase, a protein that shares epitopes with Schistosoma mansoni ATP diphosphohydrolase isoforms, in acute and chronically infected mice, after chemotherapy and reinfection

Schistosoma mansoni ATP diphosphohydrolase isoforms and potato apyrase share conserved epitopes. By enzyme-linked immunosorbent assays, elevated levels of IgM, IgG2a and IgG1 antibody reactivity against potato apyrase were observed in S. mansoni-infected BALB/c mice during the acute phase of infection, while only IgM and IgG1 antibody reactivity levels maintained elevated during the chronic phase of infection. Antibody reactivity against potato apyrase was monitored over an 11-month period in chronically-infected mice treated with oxamniquine. Eleven months later, the level of seropositive IgM decreased significantly (~30%) compared to the level found in untreated, infected mice. The level of seropositive IgG1 decreased significantly four months after treatment (MAT) (61%) and remained at this level even after 11 months. The IgG2a reactivity against potato apyrase, although unchanged during chronic phase to 11 MAT, appeared elevated again in re-infected mice suggesting a response similar to that found during the acute phase. BALB/c mouse polyclonal anti-potato apyrase IgG reacted with soluble egg antigens probably due to the recognition of parasite ATP diphosphohydrolase. This study, for the first time, showed that the IgG2a antibody from S. mansoni-infected BALB mice cross-reacts with potato apyrase and the level of IgG2a in infected mice differentiates disease phases. The results also suggest that different conserved-epitopes contribute to the immune response in schistosomiasis.

Acute schistosomiasis mansoni: revisited and reconsidered

Acute schistosomiasis is a systemic hypersensitivity reaction against the migrating schistosomula and eggs. A variety of clinical manifestations appear during the migration of schistosomes in humans: cercarial dermatitis, fever, pneumonia, diarrhoea, hepatomegaly, splenomegaly, skin lesions, liver abscesses, brain tumours and myeloradiculopathy. Hypereosinophilia is common and aids diagnosis. The disease has been overlooked, misdiagnosed, underestimated and underreported in endemic areas, but risk groups are well known, including military recruits, some religious congregations, rural tourists and people practicing recreational water sports. Serology may help in diagnosis, but the finding of necrotic-exudative granulomata in a liver biopsy specimen is pathognomonic. Differentials include malaria, tuberculosis, typhoid fever, kala-azar, prolonged Salmonella bacteraemia, lymphoma, toxocariasis, liver abscesses and fever of undetermined origin. For symptomatic hospitalised patients, treatment with steroids and schistosomicides is recommended. Treatment is curative in those timely diagnosed.

Changes in health related quality of life 3 months after an acute coronary syndrome

BACKGROUND The aim of the study was to identify the changes in Health Related Quality of Life (HRQL) 3 months after discharge from hospital, in patients who have had an acute coronary episode, and to determine the clinical and sociodemographic variables that explain those changes. METHODS HRQL was assessed in 132 patients while they were admitted to the hospital and at 3 months after discharge, using the SF-36 health questionnaire. To identify the variables associated with the change, multiple linear regression models were constructed for two summary dimensions of the SF-36 (PCS and MCS) taking the change in the score of the dimension as dependent variable. RESULTS There were no significant differences between the patients who completed the monitoring (n = 76) and those who were dropped out. After three months, a significant decrease was observed in the dimensions of physical functioning, general health, vitality, and Physical Summary Component (PCS). The variables revascularisation, age, and the interaction between previous history of coronary heart disease (CHD) and the presence of one or more risk factors explained 16.6% of the decrease in the PCS. The decrease in the PCS was 6.4 points less in the patients who had undergone revascularisation, 0.2 points less for each year of age, and 4.7 points less in the patients who had antecedents of the illness as well as one or more risk factors. CONCLUSION The dimensions most affected at three months after an acute coronary episode were those related to the physical component. Undergoing revascularisation improved the PCS in patients, but in the younger patients and those without personal antecedents or risk factors, the PCS was affected more, perhaps due to greater expectations for recovery in these patients.

Acute respiratory and cardiovascular admissions after a public smoking ban in geneva, Switzerland.

BACKGROUND: Many countries have introduced legislations for public smoking bans to reduce the harmful effects of exposure to tobacco smoke. Smoking bans cause significant reductions in admissions for acute coronary syndromes but their impact on respiratory diseases is unclear. In Geneva, Switzerland, two popular votes led to a stepwise implementation of a state smoking ban in public places, with a temporary suspension. This study evaluated the effect of this smoking ban on hospitalisations for acute respiratory and cardiovascular diseases. METHODS: This before and after intervention study was conducted at the University Hospitals of Geneva, Switzerland, across 4 periods with different smoking legislations. It included 5,345 patients with a first hospitalisation for acute coronary syndrome, ischemic stroke, acute exacerbation of chronic obstructive pulmonary disease, pneumonia and acute asthma. The main outcomes were the incidence rate ratios (IRR) of admissions for each diagnosis after the final ban compared to the pre-ban period and adjusted for age, gender, season, influenza epidemic and secular trend. RESULTS: Hospitalisations for acute exacerbation of chronic obstructive pulmonary disease significantly decreased over the 4 periods and were lowest after the final ban (IRR = 0.54 [95%CI: 0.42-0.68]). We observed a trend in reduced admissions for acute coronary syndromes (IRR = 0.90 [95%CI: 0.80-1.00]). Admissions for ischemic stroke, asthma and pneumonia did not significantly change. CONCLUSIONS: A legislative smoking ban was followed by a strong decrease in hospitalisations for acute exacerbation of chronic obstructive pulmonary disease and a trend for reduced admissions for acute coronary syndrome. Smoking bans are likely to be very beneficial for patients with chronic obstructive pulmonary disease.

Acute coronary syndromes or myocarditis in young people: a difficult daily diagnostic challenge

Background: Chest pain (CP) represents about 5% of admissions to emergency departments (ED), even in young people. Acute coronary syndrome (ACS) and myocarditis are among the most important diagnoses to rule out. Clinical and ECG findings are not specific for either condition and separating both diagnoses is a challenge. Aim of the study: To evaluate the prevalence of ACS and myocarditis in young patients presenting with CP and elevated cardiac biomarkers to the ED and to determinate the differences in their clinical presentation. Methods: Retrospective study of all consecutive patients < 40 years old admitted to our ED from January 2009 to June 2011 for CP with elevated serum troponin concentration. All clinical, angiographic and cardiac magnetic resonance (CMR) data from the local database was reviewed. Clinical follow-up was obtained to assess all cause mortality, myocardial infarction and re-hospitalisation for CP. Results: 1588 patients < 40 years old were admitted to the ED with chest pain. 49 (3%) patients presenting with an elevated troponin I (> 0.09ug/l) were included in the study. 32.7% (16/49) were diagnosed with ACS (11 STEMI and 5 NSTEMI) and 59.2% (29/49) with myocarditis. Among the 29 patients with myocarditis, 17 presented with typical subepicardial late enhancement on CMR and 12 were diagnosed based on clinical presentation (6 had no complementary workup, 3 normal coronary angiogram and 3 inconclusive CMR). 8.1% (4/49) of patients had other diagnoses. Compared to patients with myocarditis, ACS patients were older (34.1±3.9 vs 26.9±6.4, p=0.0002) with significantly more cardiovascular risk factors (mean 2.06 vs 0.69, p<0.0001). Diabetes (18.8% vs 0%, p=0.004), dyslipidemia (56.3% vs 3.4%, p=0.0001) and family history of coronary artery disease (CAD) (37.5% vs 10.3%, p=0.050) were significantly associated with ACS. No significant association was found for smoking, hypertension and obesity. Fever (>38°C) or recent viral illness were present in 75.9% (22/29) of patients with myocarditis, and in 0% of ACS patients. During follow-up (mean 19.9 months ± 8.6), only 2 patients with myocarditis were re-admitted for chest pain. Conclusions: In this study, 32.7% of patients < 40 year old admitted to an ED with CP and elevated troponin had an ACS. Key clinical factors include diabetes, dyslipidemia, family history of CAD, fever or recent viral illness, and may help to differentiate ACS from myocarditis.

Lipoprotein lipase activity and mass, apolipoprotein C-II mass and polymorphisms of apolipoproteins E and A5 in subjects with prior acute hypertriglyceridaemic pancreatitis

BACKGROUND Severe hypertriglyceridaemia due to chylomicronemia may trigger an acute pancreatitis. However, the basic underlying mechanism is usually not well understood. We decided to analyze some proteins involved in the catabolism of triglyceride-rich lipoproteins in patients with severe hypertriglyceridaemia. METHODS Twenty-four survivors of acute hypertriglyceridaemic pancreatitis (cases) and 31 patients with severe hypertriglyceridaemia (controls) were included. Clinical and anthropometrical data, chylomicronaemia, lipoprotein profile, postheparin lipoprotein lipase mass and activity, hepatic lipase activity, apolipoprotein C II and CIII mass, apo E and A5 polymorphisms were assessed. RESULTS Only five cases were found to have LPL mass and activity deficiency, all of them thin and having the first episode in childhood. No cases had apolipoprotein CII deficiency. No significant differences were found between the non-deficient LPL cases and the controls in terms of obesity, diabetes, alcohol consumption, drug therapy, gender distribution, evidence of fasting chylomicronaemia, lipid levels, LPL activity and mass, hepatic lipase activity, CII and CIII mass or apo E polymorphisms. However, the SNP S19W of apo A5 tended to be more prevalent in cases than controls (40% vs. 23%, NS). CONCLUSION Primary defects in LPL and C-II are rare in survivors of acute hypertriglyceridaemic pancreatitis; lipase activity measurements should be restricted to those having their first episode during childhood.

Impact of human metapneumovirus infection on in and outpatients for the years 2006-2008 in Southern Brazil

The human metapneumovirus (hMPV), member of the Paramyxoviridae family, has been reported as an important agent involved with acute respiratory infections (ARIs). The aim of this study is to identify hMPV as the etiological agent of ARIs on in and outpatients in the city of Curitiba, Southern Brazil, and describe clinical data of hMPV subtyping. A retrospective study was performed in 1,572 respiratory samples over a period of three years. hMPV was detected by reverse transcription-polymerase chain reaction and subtyping was performed by nucleotide sequencing. hMPV was present in 61 (3.9%) samples and subtypes A1, A2a, B1 and B2 were detected. The incidence of hMPV was higher in outpatients (5.9%), whose mean age was 19.7 years (range 6 months-75 years old), than in inpatients (3%), whose mean age was 7.6 months (range 1 month-26 years old). The outpatients had upper respiratory tract infections with flu-like symptoms and all hospitalized children had lower respiratory tract infections. A pediatric patient died from complications associated with hMPV A2a infection. hMPV has been reported as a respiratory pathogen in all age groups. No correlation was observed between viral subtype and disease severity in the samples of this study.

Endocannabinoid regulation of acute and protracted nicotine withdrawal: effect of FAAH inhibition.

Evidence shows that the endocannabinoid system modulates the addictive properties of nicotine. In the present study, we hypothesized that spontaneous withdrawal resulting from removal of chronically implanted transdermal nicotine patches is regulated by the endocannabinoid system. A 7-day nicotine dependence procedure (5.2 mg/rat/day) elicited occurrence of reliable nicotine abstinence symptoms in Wistar rats. Somatic and affective withdrawal signs were observed at 16 and 34 hours following removal of nicotine patches, respectively. Further behavioral manifestations including decrease in locomotor activity and increased weight gain also occurred during withdrawal. Expression of spontaneous nicotine withdrawal was accompanied by fluctuation in levels of the endocannabinoid anandamide (AEA) in several brain structures including the amygdala, the hippocampus, the hypothalamus and the prefrontal cortex. Conversely, levels of 2-arachidonoyl-sn-glycerol were not significantly altered. Pharmacological inhibition of fatty acid amide hydrolase (FAAH), the enzyme responsible for the intracellular degradation of AEA, by URB597 (0.1 and 0.3 mg/kg, i.p.), reduced withdrawal-induced anxiety as assessed by the elevated plus maze test and the shock-probe defensive burying paradigm, but did not prevent the occurrence of somatic signs. Together, the results indicate that pharmacological strategies aimed at enhancing endocannabinoid signaling may offer therapeutic advantages to treat the negative affective state produced by nicotine withdrawal, which is critical for the maintenance of tobacco use.

Serum ficolin-2 correlates worse than fecal calprotectin and CRP with endoscopic Crohn's disease activity.

BACKGROUND AND AIMS: Ficolin-2 is an acute phase reactant produced by the liver and targeted to recognize N-acetyl-glucosamine which is present in bacterial and fungal cell walls. We recently showed that ficolin-2 serum levels were significantly higher in CD patients compared to healthy controls. We aimed to evaluate serum ficolin-2 concentrations in CD patients regarding their correlation with endoscopic severity and to compare them with clinical activity, fecal calprotectin, and CRP. METHODS: Patients provided fecal and blood samples before undergoing ileo-colonoscopy. Disease activity was scored clinically according to the Harvey-Bradshaw Index (HBI) and endoscopically according to the simplified endoscopic score for CD (SES-CD). Ficolin-2 serum levels and fecal calprotectin levels were measured by ELISA. RESULTS: A total of 136 CD patients were prospectively included (mean age at inclusion 41.5±15.4 years, 37.5% females). Median HBI was 3 [2-6] points, median SES-CD was 5 [2-8], median fecal calprotectin was 301 [120-703] μg/g, and median serum ficolin-2 was 2.69 [2.02-3.83] μg/mL. SES-CD correlated significantly with calprotectin (R=0.676, P<0.001), CRP (R=0.458, P<0.001), HBI (R=0.385, P<0.001), and serum ficolin-2 levels (R=0.171, P=0.047). Ficolin-2 levels were higher in CD patients with mild endoscopic disease compared to patients in endoscopic remission (P=0.015) but no difference was found between patients with mild, moderate, and severe endoscopic disease. CONCLUSIONS: Ficolin-2 serum levels correlate worse with endoscopic CD activity when compared to fecal calprotectin or CRP.

Human rhinovirus in the lower respiratory tract infections of young children and the possible involvement of a secondary respiratory viral agent

Human rhinoviruses (HRV) are usually associated with mild respiratory symptoms in children. However, some studies have found that HRV can cause severe disease, especially when the patient is co-infected with a second virus. In this study, 532 nasopharyngeal aspirates (NPAs) were collected over a nine-year period from children at the Clinics Hospital of Uberlândia. The collected NPAs were then tested for HRV RNA using the reverse transcription-polymerase chain reaction. Eighty-three specimens from children diagnosed with lower respiratory tract illness (LRTI) were positive for HRV RNA and were then tested for the presence of eight other respiratory viruses. A second virus was detected in 37.3% (31/83) of the samples. The most frequent clinical diagnosis was bronchiolitis, followed by other LRTI and then pneumonia. The frequency of severe disease in children infected with more than one virus was not significantly different from the frequency of severe disease in children infected with HRV alone. Children infected with both HRV and parainfluenza virus (1.5 m.o.) were significantly younger than those infected by HRV alone (5.0 m.o.) (p = 0.0454). Overall, these results suggest that infection with a second virus does not lead to a higher frequency of severe syndromes in children presenting with LRTI.

Acute diarrhoea in a community cohort of children who received an oral rotavirus vaccine in Northeast Brazil

Rotavirus is an important cause of childhood diarrhoea. A monovalent rotavirus vaccine (Rotarix®) was introduced into the Immunization Program of Brazil in 2006. In this study, we describe the incidence and burden of disease of rotavirus diarrhoea in two cohorts of children (vaccinated and unvaccinated). We followed two groups of 250 children under one year old, who were enrolled in December 2006 from a low-income residential area in Northeast Brazil. The children were monitored every two weeks for two years. Stool samples from children with diarrhoea were examined for the presence of rotavirus. Rotaviruses were genotyped using real time-polymerase chain reaction. The mean numbers of all-cause diarrhoea episodes/child (adjusted for age) in the first year were 0.87 and 0.84, in vaccinated and unvaccinated children, respectively. During the second year, the number of episodes/child decreased to 0.52 and 0.42. Only 16 (4.9%) of 330 stool samples were rotavirus-positive (10 vaccinated and 6 unvaccinated children) and only P[4]G2 rotaviruses were identified. All-cause diarrhoea episodes were more severe in unvaccinated children in the first year of age (p < 0.05), while vaccinated children had more severe episodes 18 months after vaccination. Rotavirus diarrhoea incidence was very low in both groups.

Ocular toxoplasmosis: evaluation of lacrimal - specific secretory IgA levels in both patients with active and inactive phases of the disease

Ocular toxoplasmosis can result in recurrent uveitis. Studies have shown that a correlation between active ocular toxoplasmosis and the presence of anti-Toxoplasma gondii secretory IgA (SIgA) in tears. This study compares anti-T. gondii SIgA levels in patients' tears during the acute and inactive phases of toxoplasmic uveitis. Twenty-nine positive tear specific SIgA for T. gondii patients with acute toxoplasmic uveitis were selected and were followed-up for at least two years, when the anti-T. gondii SIgA tears levels were determined. Specific SIgA for T. gondii was negative in 22 patients (75.86%) and positive in seven patients (24.13%) of whom six (85.7%) were followed over three years. Average SIgA levels during the acute phase are 1.54 and decrease significantly to 0.72 (p = 0.0001) during the inactive phase of disease. Because anti-T. gondii SIgA in the tear is negative in 75.86% of patients after the acute phase of infection, T. gondii SIgA levels may be used as a complementary diagnostic marker for active ocular toxoplasmosis.

Insulin receptor substrate-1 expression is increased in circulating leukocytes of patients with acute coronary syndrome.

The mechanisms underlying the increased risk of cardiovascular disease associated with diabetes mellitus (DM) are not fully defined. Insulin resistance in human metabolic syndrome patients is associated with decreased expression of the insulin receptor substrate-2- (Irs2-) AKT2 axis in mononuclear leukocytes (MLs). Moreover, acute coronary syndrome (ACS) has been linked through genome-wide association studies to the 2q36-q37.3 locus, which contains the Irs1 gene. Here, we investigated the expression of insulin-signaling pathway genes in MLs from patients with DM, ACS, and ACS plus DM. Quantitative real-time PCR expression studies showed no differences in the mRNA levels of Irs2, Akt2, and Akt1 among all patients. However, Irs1 mRNA expression was significantly increased in patients with ACS-diabetics and nondiabetics-compared with diabetic patients without ACS (P < .02 and P < .005, resp.). The present study reveals for the first time an association between increased Irs1 mRNA levels in MLs of patients with ACS which is not related to DM.