Effects of nandrolone decanoate on telomere length and clinical outcome in patients with telomeropathies: a prospective trial.

Androgens have been reported to elongate telomeres in retrospective and prospective trials with patients with telomeropathies, mainly with bone marrow failure. In our single-arm prospective clinical trial (clinicaltrials gov. Identifier: NCT02055456), 17 patients with short telomeres and/or germline pathogenic variants in telomere biology genes associated with at least one cytopenia and/or radiologic diagnosis of interstitial lung disease were treated with 5 mg/kg of intramuscular nandrolone decanoate every 15 days for 2 years. Ten of 13 evaluable patients (77%) showed telomere elongation at 12 months by flow-fluorescence in situ hybridization (average increase, 0.87 kb; 95% confidence interval: 0.20-1.55 kb; P=0.01). At 24 months, all ten evaluable patients showed telomere elongation (average increase, 0.49 kb; 95% confidence interval: 0.24-1.23 kb; P=0.18). Hematologic response was achieved in eight of 16 patients (50%) with marrow failure at 12 months, and in ten of 16 patients (63%) at 24 months. Seven patients had interstitial lung disease at baseline, and two and three had pulmonary response at 12 and 24 months, respectively. Two patients died due to pulmonary failure during treatment. In the remaining evaluable patients, the pulmonary function remained stable or improved, but showed consistent decline after cessation of treatment. Somatic mutations in myeloid neoplasm-related genes were present in a minority of patients and were mostly stable during drug treatment. The most common adverse events were elevations in liver function test levels in 88%, acne in 59%, and virilization in 59%. No adverse events grade ≥4 was observed. Our findings indicate that nandrolone decanoate elongates telomeres in patients with telomeropathies, which correlated with clinical improvement in some cases and tolerable adverse events.

A new cure rate regression framework for bivariate data based on the Chen distribution.

The present study introduces a new multivariate mixture cure rate model based on the Chen probability distribution to model recurrent event data in the presence of cure fraction. In this context, we provide an alternative for the use of some usual modeling approaches as the semiparametric Cox proportional hazards model commonly used in lifetime data analysis, considering a new bivariate parametric model to be used in the data analysis of bivariate lifetime data assuming a mixture structure for the bivariate data in presence of covariates, censored data and cure fraction. Under a Bayesian setting, the proposed methodology was considered to analyze two real medical datasets from a retrospective cohort study related to leukemia and diabetic retinopathy diseases. The model validation process was addressed by using the Cox-Snell residuals, which allowed us to identify the suitability of the new proposed mixture cure rate model.

Association between leukocyte telomere length and sex by quantile regression analysis

ABSTRACT Introduction: Telomere length (TL) is a biomarker of cellular proliferative history. In healthy individuals, leukocyte TL shortens with age and associates with the lifespan of men and women. However, most of studies had used linear regression models to address the association of the TL attrition, aging and sex. Methods: We evaluated the association between the TL, aging and sex in a cohort of 180 healthy subjects by quantile regression. The TL of nucleated blood cells was measured by fluorescent in situ hypridization (flow-FISH) in a cohort of 89 men, 81 women, and 10 umbilical cord samples. The results were validated by quantitative polymerase chain reaction (qPCR) and compared to a linear regression analysis. Results: By quantile regression, telomere dynamics slightly differed between sexes with aging: women had longer telomeres at birth and slower attrition rate than men until the sixth decade of life; after that, TL eroded faster and became shorter than that in men. These differences were not observed by linear regression analysis, as the overall telomere attrition rates in women and men were similar (42 pb per year, p < 0.0001 vs. 45 pb kb per year, p < 0.0001). Also, qPCR did not recapitulate flow-FISH findings, as the telomere dynamics by qPCR followed a linear model. Conclusion: The quantile regression analysis accurately reproduced a third-orderpolynomial TL attrition rate in both women and men, but it depended on the technique applied to measure TL. The Flow-FISH reproduced the expected telomere dynamics through life and, differently from the qPCR, was able to detect the subtle TL variations associated with sex and aging.

Association between leukocyte telomere length and sex by quantile regression analysis.

INTRODUCTION: Telomere length (TL) is a biomarker of cellular proliferative history. In healthy individuals, leukocyte TL shortens with age and associates with the lifespan of men and women. However, most of studies had used linear regression models to address the association of the TL attrition, aging and sex. METHODS: We evaluated the association between the TL, aging and sex in a cohort of 180 healthy subjects by quantile regression. The TL of nucleated blood cells was measured by fluorescent in situ hypridization (flow-FISH) in a cohort of 89 men, 81 women, and 10 umbilical cord samples. The results were validated by quantitative polymerase chain reaction (qPCR) and compared to a linear regression analysis. RESULTS: By quantile regression, telomere dynamics slightly differed between sexes with aging: women had longer telomeres at birth and slower attrition rate than men until the sixth decade of life; after that, TL eroded faster and became shorter than that in men. These differences were not observed by linear regression analysis, as the overall telomere attrition rates in women and men were similar (42 pb per year, p < 0.0001 vs. 45 pb kb per year, p < 0.0001). Also, qPCR did not recapitulate flow-FISH findings, as the telomere dynamics by qPCR followed a linear model. CONCLUSION: The quantile regression analysis accurately reproduced a third-order polynomial TL attrition rate in both women and men, but it depended on the technique applied to measure TL. The Flow-FISH reproduced the expected telomere dynamics through life and, differently from the qPCR, was able to detect the subtle TL variations associated with sex and aging.

Dynamic plantar pressure patterns in children and adolescents with Charcot-Marie-Tooth disease.

BACKGROUND: The dynamic plantar pressure patterns of children and adolescents with Charcot-Marie-Tooth (CMT) disease and its relationship to musculoskeletal alterations may help to understand the natural history of the disease and improve therapeutic interventions. RESEARCH QUESTION: The study compared dynamic plantar pressure patterns in children and adolescents with and without CMT. It also tested the associations between isometric muscle strength (IMS), passive range of motion (ROM), foot posture and dynamic plantar pressure patterns in CMT. METHODS: This cross-sectional study compared children and adolescents (aged 8-18 years) with CMT (n = 40) with a typical group (n = 40). The plantar pressure distribution during gait was recorded, and the contact area (CA), peak pressure (PP), contact time (CT) and pressure-time integral (PTI) in five foot regions (rearfoot, midfoot lateral, midfoot medial, lateral forefoot and medial forefoot) were analysed. The IMS of the dorsiflexors and plantar flexors, passive ROM, and foot posture were also recorded. RESULTS: PP (medial midfoot and medial forefoot) and PTI (rearfoot, lateral midfoot and medial forefoot) were higher in children with CMT compared with the typical group. The adolescents with CMT presented a less CA (whole foot) and a higher CT (medial midfoot) when compared with typical group. For CMT, in the medial midfoot, plantar flexor IMS associated with PP (ß=-11.54, p = 0.01) and PTI (ß=-3.38, p = 0.04); supinated foot posture associated with PP (ß = 33.89, p = 0.03) and PTI (ß = 12.01, p = 0.03). SIGNIFICANCE: Children with CMT showed clear changes in most of the dynamic plantar pressure variables, while adolescents with CMT showed changes mostly in CA and CT. This information together with the associations established between supinated foot, dorsiflexion ROM and plantar flexions IMS can be useful for guiding rehabilitation professionals in their therapies.

Association of religiosity with mental health and quality of life in women with chronic pelvic pain.

OBJECTIVE: This study evaluated religiosity and its association with mental health, quality of life, and the intensity of pelvic pain in women with chronic pelvic pain. METHODS: A cross-sectional study was conducted with 100 women with chronic pelvic pain. Religiosity was investigated using the Duke University Religion Index. Quality of life was evaluated using the abbreviated version of the World Health Organization's quality of life instrument. Depression and anxiety were assessed using the Hospital Anxiety and Depression Scale, while pain intensity was evaluated using a visual analog scale. RESULTS: Almost half the participants attended religious services at least once a week and 62% prayed, meditated, or studied the Bible at least once a day. There was no association between religiosity and anxiety or depression. The intrinsic religiosity score was lower for women with mixed anxiety-depressive disorder compared to those without mixed anxiety-depressive disorder. There was a positive association between intrinsic religiosity and the psychological health domain of the quality of life instrument. There was no association between religiosity and pain intensity. CONCLUSIONS: Women with chronic pelvic pain were strongly religious. Women with mixed anxiety-depressive disorder had lower levels of intrinsic religiosity. On the other hand, intrinsic religiosity was positively associated with quality of life in women with chronic pelvic pain. Religiosity was not associated with the intensity of pelvic pain. These data suggest that health-care professionals should take religiosity into account when treating women with chronic pelvic pain.

A Bayesian analysis for pseudo-compositional data with spatial structure.

We proposed a Bayesian analysis of pseudo-compositional data in presence of a latent factor, assuming a spatial structure. This development was motivated by a dataset containing information on the number of newborns of primiparous mothers living in each of the microregions of the state of Sao Paulo, Brazil, in the year of 2015, stratified by the age of the mothers (15-18, 19-29 and 30 years or more). Considering that data on newborns are not stochastically distributed among the three age groups, but they are explained in relation to women's population structure, we adopted the expression "pseudo-compositional data" to refer to this data structure. The hypothesis of interest establishes that the age of the first pregnancy is associated with the economic conditions of the geographic area where the mother lives. The incidence of poverty was included as an independent variable. Additive log-ratio (alr) and isometric log-ratio (ilr) transformations were considered, as is usually done in the analysis of compositional data. The model included a random effect related to the spatial effect assumed to have a conditional autoregressive structure. A Bayesian Markov Chain Monte Carlo (MCMC) simulation procedure was used to get the posterior summaries of interest. The model based on the (ilr) transformation was well fitted to the data, showing that in the microregions with the highest incidence of poverty, there are higher proportions of women who have their first child in adolescence, while in the microregions with the lowest incidence of poverty, there are higher proportions of women who have their first child after the age of 30 years. From these results it is possible to conclude that this Bayesian approach was very useful in the estimation of the parameters of the proposed model. The proposed method should have a broad application to other problems involving pseudo-compositional data.

Factors that contribute to blood donation behavior among primary healthcare users: A structural approach.

This study aimed to evaluate the relative contribution of psychosocial variables to donation behavior in a sample of primary healthcare users in a Brazilian municipality. Donor recruitment and retention continue to pose significant challenges to blood collection services worldwide and is especially important among low and middle income countries (LMICs), challenged with higher rates of stigma and low public awareness about donation. A cross-sectional study with randomized stratified sampling of 1055 primary healthcare users was conducted across 12 healthcare facilities in Ribeirão Preto, state of São Paulo. Participants completed measures assessing psychosocial variables, including religiosity, knowledge regarding blood donation process, overall quality of life, blood donation of peers, sociodemographic variables, and the fear of blood, injections, and fainting. The associations between psychosocial variables and donation behaviour was examined using structural equation modelling. Blood donation was more frequent in males and among individuals with higher socioeconomic and educational levels. The structural model indicated associations between blood donation behaviour and fear, knowledge, age, sex, socioeconomic status, and educational level. Fear of blood, injections and vasovagal reactions, and a lack of knowledge of the donation process were revealed as important barriers to the decision to donate blood. In addition, there is evidence that considering the population of primary healthcare users, the women, the youngers, and those with lower socioeconomic status and lower educational level are less likely to donate blood.

Evaluation of potential herbal-drug interactions of a standardized propolis extract (EPP-AF®) using an in vivo cocktail approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Propolis has been employed extensively in many cultures since ancient times as antiseptic, wound healing, anti-pyretic and others due to its biological and pharmacological properties, such as immunomodulatory, antitumor, anti-inflammatory, antioxidant, antibacterial, antiviral, antifungal, antiparasite activities. But despite its broad and traditional use, there is little knowledge about its potential interaction with prescription drugs. AIM OF THE STUDY: The main objective of this work was to study the potential herbal-drug interactions (HDIs) of EPP-AF® using an in vivo assay with a cocktail approach. MATERIALS AND METHODS: Subtherapeutic doses of caffeine, losartan, omeprazole, metoprolol, midazolam and fexofenadine were used. Sixteen healthy adult volunteers were investigated before and after exposure to orally administered 125 mg/8 h (375 mg/day) EPP-AF® for 15 days. Pharmacokinetic parameters were calculated based on plasma concentration versus time (AUC) curves. RESULTS: After exposure to EPP-AF®, it was observed decrease in the AUC0-∞ of fexofenadine, caffeine and losartan of approximately 18% (62.20 × 51.00 h.ng/mL), 8% (1085 × 999 h.ng/mL) and 13% (9.01 × 7.86 h.ng/mL), respectively, with all 90% CIs within the equivalence range of 0.80-1.25. On the other hand, omeprazole and midazolam exhibited an increase in AUC0-∞ of, respectively, approximately 18% (18.90 × 22.30 h.ng/mL) and 14% (1.25 × 1.43 h.ng/mL), with the upper bounds of 90% CIs slightly above 1.25. Changes in pharmacokinetics of metoprolol or its metabolite α-hydroxymetoprolol were not statistically significant and their 90% CIs were within the equivalence range of 0.80-1.25. CONCLUSIONS: In conclusion, our study shows that EPP-AF® does not clinically change CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A activities, once, despite statistical significant, the magnitude of the changes in AUC values after EPP-AF® were all below 20% and therefore may be considered safe regarding potential interactions involving these enzymes. Besides, to the best of our knowledge this is the first study to assess potential HDIs with propolis.

Blood donation deferral policies among men who have sex with men in Brazil

ABSTRACT Reevaluation of the deferral from voluntary blood donation by men who have sex with men (MSM) is being discussed in several countries, motivated by the need to ensure a blood supply free from transfusion-transmissible infections (e.g., HIV, syphilis). Policies being considered include: permanent exclusion for any male-male sexual encounter, temporary deferral (3 months, 12 months, 5 years) from the last encounter, or specifying behaviors that differentiate MSM at high risk from those at low risk. Current Brazilian regulations defer MSM from blood donation for 12-months after the last male-male sexual encounter. Broad epidemiological evidence indicates that many MSM are at increased risk for HIV in the present era, and few data exist to distinguish which men are likely to be in the immunological window for detection of these infections. A multicenter study developed in Brazil demonstrated that the history of male-male sex was the most strongly associated with being an HIV-positive blood donor. Meanwhile, the blanket deferral of MSM from blood donation has generated considerable controversy. Rejection of the deferral policies stems in part from perspectives defending human rights, promoting equality and citizenship, and alleging bias and discrimination. The objective of this report is to discuss the current situation of blood donation among MSM in Brazil. We highlight the lack of evidence for a true risk profile for male-male sex in the context of blood donation upon which to base sound policy. We recommend research to establish effective and acceptable criteria for blood donation by MSM and other blood donors.

Blood donation deferral policies among men who have sex with men in Brazil.

Reevaluation of the deferral from voluntary blood donation by men who have sex with men (MSM) is being discussed in several countries, motivated by the need to ensure a blood supply free from transfusion-transmissible infections (e.g., HIV, syphilis). Policies being considered include: permanent exclusion for any male-male sexual encounter, temporary deferral (3 months, 12 months, 5 years) from the last encounter, or specifying behaviors that differentiate MSM at high risk from those at low risk. Current Brazilian regulations defer MSM from blood donation for 12-months after the last male-male sexual encounter. Broad epidemiological evidence indicates that many MSM are at increased risk for HIV in the present era, and few data exist to distinguish which men are likely to be in the immunological window for detection of these infections. A multicenter study developed in Brazil demonstrated that the history of male-male sex was the most strongly associated with being an HIV-positive blood donor. Meanwhile, the blanket deferral of MSM from blood donation has generated considerable controversy. Rejection of the deferral policies stems in part from perspectives defending human rights, promoting equality and citizenship, and alleging bias and discrimination. The objective of this report is to discuss the current situation of blood donation among MSM in Brazil. We highlight the lack of evidence for a true risk profile for male-male sex in the context of blood donation upon which to base sound policy. We recommend research to establish effective and acceptable criteria for blood donation by MSM and other blood donors.

Prevalence of hepatitis E virus infection in multiple transfused Brazilian patients with thalassemia and sickle cell disease.

Hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide. The virus is acquired by fecal-oral route; however, it can also be transmitted by blood transfusion. The objective of the study was to examine anti-HEV immunoglobulin G and HEV RNA prevalence in multiple transfused patients with thalassemia and sickle cell disease (SCD), and in blood donors. The HEV seroprevalence in the patients was 13% (20% in thalassemics; 7.7% in SCD), and 11% in blood donors. No positive result for HEV RNA was obtained. This is a pioneer study examining HEV circulation in Brazilian patients with hemoglobinopathies.

Spatial distribution of Robson 10-group classification system and poverty in southern and southeastern Brazil.

OBJECTIVE: To assess the spatial distribution of the Robson 10-group classification system (TGCS) and poverty in southeastern and southern regions of Brazil in 2016. METHODS: An ecologic study based on public data from the Brazilian Information System on Live Births and the Brazilian Institute of Geography and Statistics, including 1 519 289 (53.2%) of all live-born neonates in Brazil between January and December 2016. Statistical analysis used Bayesian modelling with spatial distribution following an autoregressive conditional structure, and Moran index. RESULTS: In 2016, the percentage of live-born neonates delivered by cesarean was 58.8% and 60.7% in the southeastern and southern regions, respectively. Robson groups 1 and 3, involving spontaneous labor, were related to regions with higher poverty (Moran index, 0.36 and 0.44, respectively), whereas groups 2 and 5, involving cesarean delivery, were related to poorer regions (Moran index, 0.56 and 0.45, respectively). CONCLUSION: The frequencies of each group of the Robson TGCS were heterogeneously distributed in the geographic space owing to important associations with the proportion of poverty in the different regions. Actions are needed to develop the poorest regions in order to minimize existing disparities.

Comparison of the demographic and social profile of blood donors and nondonors in Brazil.

Population-based studies on blood donation prevalence and its association with sociodemographic and behavioural factors are scarce, but remain the best approach to assess correlates of donation, including those which could be the target for donor recruitment campaigns. This study describes the population of primary healthcare users from the public system in a medium-sized Brazilian municipality to investigate the association of blood donation practice with other sociodemographic factors. A stratified, representative sample of primary healthcare users at 12 healthcare facilities in Ribeirão Preto, São Paulo, Brazil, were invited to participate. Analysis focused on demographic and psychosocial factors including, sex, age, marital status, socioeconomic status, educational level, health insurance, self-perception of health, religious beliefs, and blood donation history. Blood donors, self-defined ineligible donors, and never donors were compared. Multiple correspondence analysis (MCA) was used to assess positively and negatively associated variables in the dataset. MCA was conducted on respondents' age and monthly household income to assess dimensionality of other questionnaire responses. Of a total of 1,055 study participants, 79.7% were females and the mean age was 40.6 years. Blood donation practice was reported by 246 participants (23.3%), 669 (63.4%) had never donated, and 140 (13.3%) reported being unable to donate blood. Graphical presentation of the MCA showed that male, older age groups, those who have health insurance, and with higher socioeconomic and educational level are more likely to donate blood. Poor or average self-perception of health, lower socioeconomic status, and divorced or widowed marital status were associated with self-defined inability to donate blood. Thus, our results are useful to understand the multifactorial nature of blood donation behaviour. Our findings provide guidance for targeted recruitment campaigns focused on relevant contextual factors. The focus on reducing barriers to blood donation according to sociodemographic groups can be a relevant strategy to expand the donor base.

Cognitive Decline in Adults Aged 65 and Older in Cumbayá, Quito, Ecuador: Prevalence and Risk Factors.

Objective To assess the prevalence of and risk factors for cognitive decline and dementia in individuals greater than 65 years of age in Cumbayá, Quito, Ecuador. Methods This is a cross-sectional observational study that was carried out in adults over age 65. The Mini Mental State Examination (MMSE), Ascertain Dementia Eight-Item Informant Questionnaire (AD8), and Mini Nutritional Assessment (MNA) were used to assess the cognitive status and nutritional habits of this population. Results A total of 144 patients (mean age 75.3 years, 77.1% female) participated in this study. Forty percent of patients had AD8 and MMSE scores consistent with cognitive impairment and possible dementia. Age (p < 0.01), lower educational level (p < 0.01), history of stroke (p < 0.01), history of intracerebral hemorrhage (p < 0.01), diabetes mellitus (p < 0.01), and malnutrition (p < 0.01) were statistically significant risk factors for cognitive impairment. Exercise was found to be protective against cognitive decline in our study group (p < 0.03). Gender, ethnicity, location, head trauma, Parkinson disease, hypercholesterolemia, myocardial infarction, thyroid disease, depression, anxiety, and family history of dementia were not found to be associated with cognitive decline in this population. Conclusions The prevalence of cognitive impairment and possible dementia is 18-21% at age 65 and 54-60% at age 85 in Cumbayá, Quito, Ecuador. The major risk factors for cognitive impairment in this population are age, low educational level, malnutrition, prior stroke, prior intracerebral hemorrhage, and diabetes. Protective factors for cognitive decline include exercise and possibly modest consumption of alcohol.

Diabetic retinopathy among Brazilian Xavante Indians.

BACKGROUND: To describe the frequency of diabetic retinopathy (DR) and its associated variables in Brazilian Xavante Indians. METHODS: A population-based survey carried out in two Xavante Reservations between 2008 and 2012, included 948 Indians aged 20 years or more, identified 246 individuals with type 2 diabetes. A non-probabilistic cluster sample of 140 diabetic individuals were submitted to ophthalmologic examination. Due to operational conditions and to optimize the field work, only the larger Xavante villages were included. Ophthalmologic examinations were performed during one trip to each reservation, in their villages and consisted of measurement visual acuity, anterior segment biomicroscopy, applanation tonometry, and direct and indirect ophthalmoscopy. RESULTS: The frequency of DR was 19.3%, distributed as follows: mild non-proliferative retinopathy in nine (33.3%) subjects, moderate in nine (33.3%), severe in six (22.3%), very severe in two (7.4%), and high-risk proliferative DR in one (3.7%). The occurrence of DR was higher among those with a longer duration of diabetes, higher levels of glycated hemoglobin (HbA1c) and fasting glucose, papillary excavation ≥ 0.5, and among individuals in older age group. Using the log-binomial regression model, diabetes duration > 24 months and HbA1c ≥ 6.5% were significantly associated with the occurrence of DR. CONCLUSIONS: The presence of DR (19.3%) in Xavante Indians is an alert for health care providers for this population, since diabetes is a new disease among them. Its association with disease duration, high levels of HbA1c and blood glucose calls attention for the necessity of more actions to improve diabetes control in this recently contacted ethnic group that needs particular attention.

Increased exposure to pesticides and colon cancer: Early evidence in Brazil.

Environmental factors may increase colon cancer (CC) risk. It has been suggested that pesticides could play a significant role in the etiology of this malignancy. As agriculture is one of the mainstays of the Brazilian economy, this country has become the largest pesticides consumer worldwide. The CC burden is also increasing in Brazil. Herein, we examined data from the Brazilian Federal Government to determine whether CC mortality and pesticide consumption may be associated. Database of the Ministry of Health provided CC mortality data in Brazil, while pesticide usage was accessed at the website of Brazilian Institute of Environment and Renewable Natural Resources. The CC mortality in the Brazilian states was calculated as standard mortality rates (SMR). All Bayesian analysis was performed using a Markov chain Monte Carlo method in WinBUGS software. We observed that CC mortality has exhibited a steady increase for more than a decade, which correlated with the amount of sold pesticides in the country. Both observations are concentrated in the Southern and the Southeast regions of Brazil. Although ecological studies like ours have methodological limitations, the current dataset suggests the possibility that pesticide exposure may be a risk factor for CC. It warrants further investigation.

The efficacy and safety of mannitol challenge in a workplace setting for assessing asthma prevalence.

OBJECTIVE: There is no standard definition of asthma for epidemiological purposes; most surveys use symptoms and bronchial hyperresponsiveness. Few studies tested mannitol challenge test (MCT) in occupational settings. We sought to determine efficacy and safety of MCT in detecting subjects with asthma symptoms in the workplace. METHODS: In this cross-sectional study we recruited 908 workers in 2 universities; they underwent a respiratory questionnaire, spirometry, skin prick tests, and MCT. RESULTS: Eight hundred and eleven subjects completed the study; 11.1% had a positive MCT; 8.14% had asthma. MCT had low sensitivity (35.4-61.9%) but high specificity (90.2-94.9%) to detect symptomatic individuals. The most prevalent symptom was wheezing in the last 12 months. Twenty-four of those with a positive MCT (26.7%) had no positive replies to the questions on asthma symptoms. Among subjects with a positive MCT, 71.9% achieved 95% of baseline FEV1 after 15 minutes of salbutamol recovery treatment. Nine subjects (1.1%) had adverse events that prevented the test from being completed. CONCLUSIONS: MCT has high specificity but low sensitivity to detect symptomatic subjects in the workplace. It may detect subjects with hyperresponsiveness but no symptoms, who could be at risk of developing airway diseases. The test is safe and well tolerated.

Discovery of human scFvs that cross-neutralize the toxic effects of B. jararacussu and C. d. terrificus venoms.

Accidents involving venomous snakes are a public health problem worldwide, causing a large number of deaths per year. In Brazil, the majority of accidents are caused by the Bothrops and Crotalus genera, which are responsible for approximately 80% of severe envenoming cases. The cross-neutralization of snake venoms by antibodies is an important issue for development of more effective treatments. Our group has previously reported the construction of human monoclonal antibody fragments towards Bothrops jararacussu and Crotalus durissus terrificus' venoms. This study aimed to select human single-chain variable fragments (scFvs) that recognize both bothropic and crotalic crude venoms following venoms neutralizing capacity in vitro and in vivo. The cross-reactivity of Cro-Bothrumabs were demonstrated by ELISA and in vitro and in vivo experiments showed that a combination of scFvs neutralizes in vitro toxic activities (e.g. indirect hemolysis and plasma-clotting) of crotalic and bothropic venoms as well as prolonged survival time of envenomed animals. Our results may contribute to the development of the first human polyvalent antivenom against Bothrops jararacussu and Crotalus durissus terrificus venoms, overcoming some undesirable effects caused by conventional serotherapy.

Human scFv antibodies (Afribumabs) against Africanized bee venom: Advances in melittin recognition.

Africanized Apis mellifera bees, also known as killer bees, have an exceptional defensive instinct, characterized by mass attacks that may cause envenomation or death. From the years 2000-2013, 77,066 bee accidents occurred in Brazil. Bee venom comprises several substances, including melittin and phospholipase A2 (PLA2). Due to the lack of antivenom for bee envenomation, this study aimed to produce human monoclonal antibody fragments (single chain fragment variable; scFv), by using phage display technology. These fragments targeted melittin and PLA2, the two major components of bee venom, to minimize their toxic effects in cases of mass envenomation. Two phage antibody selections were performed using purified melittin. As the commercial melittin is contaminated with PLA2, phages specific to PLA2 were also obtained during one of the selections. Specific clones for melittin and PLA2 were selected for the production of soluble scFvs, named here Afribumabs: prefix: afrib- (from Africanized bee); stem/suffix: -umab (fully human antibody). Afribumabs 1 and 2 were tested in in vitro and in vivo assays to assess their ability to inhibit the toxic actions of purified melittin, PLA2, and crude bee venom. Afribumabs reduced hemolysis caused by purified melittin and PLA2 and by crude venom in vitro and reduced edema formation in the paws of mice and prolonged the survival of venom-injected animals in vivo. These results demonstrate that Afribumabs may contribute to the production of the first non-heterologous antivenom treatment against bee envenomation. Such a treatment may overcome some of the difficulties associated with conventional immunotherapy techniques.