50 research outputs found
Genetic and morphometric variation in Schwarziana quadripunctata and Schwarziana mourei (Hymenoptera: Apidae: Meliponini)
Schwarziana bees are a ground-nesting stingless bee distributed in the Neotropical region. Schwarziana quadripunctata was the first described and the most studied species of this genus. Now, there are four valid species of Schwarziana bees, but it has been suggested that the diversity of this taxon may be higher, due to undescribed cryptic species. In this study, we investigated the populational diversity of S. quadripunctata using workers collected at 11 localities in Brazil (from the Northeast to South region). We also included one population of S. mourei (collected in São Paulo state, 2 nests). We analysed the bees using geometric morphometrics and molecular analyses amplifying mtDNA cytochrome oxidase I (COI) and 16S to access the diversity among the populations. From the results of geometric morphometrics, the Mahalanobis distances between S. mourei and S. quadripunctata are greater than those distances among S. quadripunctata populations. A similar scenario can also be observed looking to the phylogenetic tree generated by the molecular markers. Morphometry and molecular markers data showed significant association with geographic distance, indicating the existence of intrapopulation variation in S. quadripunctata. Our hypothesis was supported, that the populations of S. quadripunctata showed differences in haplotypic diversity. Overall, these analyses revealed a moderate level of intraspecific variation among S. quadripunctata populations and discriminated well the species S. quadripunctata from S. mourei
Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil
As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European
Carglumic acid enhances rapid ammonia detoxification in classical organic acidurias with a favourable risk-benefit profile: A retrospective observational study
BACKGROUND: Isovaleric aciduria (IVA), propionic aciduria (PA) and methylmalonic aciduria (MMA) are inherited organic acidurias (OAs) in which impaired organic acid metabolism induces hyperammonaemia arising partly from secondary deficiency of N-acetylglutamate (NAG) synthase. Rapid reduction in plasma ammonia is required to prevent neurological complications. This retrospective, multicentre, open-label, uncontrolled, phase IIIb study evaluated the efficacy and safety of carglumic acid, a synthetic structural analogue of NAG, for treating hyperammonaemia during OA decompensation. METHODS: Eligible patients had confirmed OA and hyperammonaemia (plasma NH3 > 60 μmol/L) in ≥1 decompensation episode treated with carglumic acid (dose discretionary, mean (SD) first dose 96.3 (73.8) mg/kg). The primary outcome was change in plasma ammonia from baseline to endpoint (last available ammonia measurement at ≤18 hours after the last carglumic acid administration, or on Day 15) for each episode. Secondary outcomes included clinical response and safety. RESULTS: The efficacy population (received ≥1 dose of study drug and had post-baseline measurements) comprised 41 patients (MMA: 21, PA: 16, IVA: 4) with 48 decompensation episodes (MMA: 25, PA: 19, IVA: 4). Mean baseline plasma ammonia concentration was 468.3 (±365.3) μmol/L in neonates (29 episodes) and 171.3 (±75.7) μmol/L in non-neonates (19 episodes). At endpoint the mean plasma NH3 concentration was 60.7 (±36.5) μmol/L in neonates and 55.2 (±21.8) μmol/L in non-neonates. Median time to normalise ammonaemia was 38.4 hours in neonates vs 28.3 hours in non-neonates and was similar between OA subgroups (MMA: 37.5 hours, PA: 36.0 hours, IVA: 40.5 hours). Median time to ammonia normalisation was 1.5 and 1.6 days in patients receiving and not receiving concomitant scavenger therapy, respectively. Although patients receiving carglumic acid with scavengers had a greater reduction in plasma ammonia, the endpoint ammonia levels were similar with or without scavenger therapy. Clinical symptoms improved with therapy. Twenty-five of 57 patients in the safety population (67 episodes) experienced AEs, most of which were not drug-related. Overall, carglumic acid seems to have a good safety profile for treating hyperammonaemia during OA decompensation. CONCLUSION: Carglumic acid when used with or without ammonia scavengers, is an effective treatment for restoration of normal plasma ammonia concentrations in hyperammonaemic episodes in OA patients
At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension
Hypertension affects 1–5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review
Macrophage signaling in HIV-1 infection
The human immunodeficiency virus-1 (HIV-1) is a member of the lentivirus genus. The virus does not rely exclusively on the host cell machinery, but also on viral proteins that act as molecular switches during the viral life cycle which play significant functions in viral pathogenesis, notably by modulating cell signaling. The role of HIV-1 proteins (Nef, Tat, Vpr, and gp120) in modulating macrophage signaling has been recently unveiled. Accessory, regulatory, and structural HIV-1 proteins interact with signaling pathways in infected macrophages. In addition, exogenous Nef, Tat, Vpr, and gp120 proteins have been detected in the serum of HIV-1 infected patients. Possibly, these proteins are released by infected/apoptotic cells. Exogenous accessory regulatory HIV-1 proteins are able to enter macrophages and modulate cellular machineries including those that affect viral transcription. Furthermore HIV-1 proteins, e.g., gp120, may exert their effects by interacting with cell surface membrane receptors, especially chemokine co-receptors. By activating the signaling pathways such as NF-kappaB, MAP kinase (MAPK) and JAK/STAT, HIV-1 proteins promote viral replication by stimulating transcription from the long terminal repeat (LTR) in infected macrophages; they are also involved in macrophage-mediated bystander T cell apoptosis. The role of HIV-1 proteins in the modulation of macrophage signaling will be discussed in regard to the formation of viral reservoirs and macrophage-mediated T cell apoptosis during HIV-1 infection
Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial
Background:
Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment.
Methods:
This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal.
Results:
Enrolment began in 2016, and the study is expected to end in 2020.
Conclusions:
This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission.
Clinical trial reference number:
EudraCT 2015-001410-1
Urea cycle disorders in Spain: an observational, cross-sectional and multicentric study of 104 cases
Clinal variation and selection on MDH allozymes in honeybees in Chile
Evidence of clinal variation and selection on Mdh-1 locus was observed in 27 samples from 22 sites in a 2800 km north-south transect across Chile. We found a negative correlation among F allele normalized frequency and mean temperature, and minimum temperature of January and July, as well as a positive correlation among S allele normalized frequency and annual mean, and minimum January temperatures. Our results lend weight to the idea that Chilean honeybee populations of colder areas have higher F allele frequencies, supporting previous claims that Mdh-l allozymes of Apis mellifera are subject to temperature-mediated selection
Genetic characterization of a polymorphic dipeptidyl aminopeptidase of Apis mellifera
Dipeptidyl aminopeptidase (DAP) activity towards L-leucylglycine-beta-naphthylamide (Leu-Gly NA) was characterized in pupae and adult extracts of Apis mellifera. Enzyme activity was more conspicuous in pupae than in adult extracts and it seemed to be concentrated in digestive tract tissues. Two genetically determined electrophoretic variants were observed in honeybee samples from the USA and Chile; in Brazilian Africanized bees, two additional variants were observed. Segregational analyses showed no close linkage between Dap and Est-1, Lap D, Pgm-1, cd, and Ac loci of Apis mellifera
La protecció dels infants i els adolescents en els mitjans de comunicació: el menor d’edat com a espectador i com a protagonista
El present treball d’investigació es divideix en dos parts. La primera part està dedicada al menor d’edat com a protagonista dels mitjans de comunicació. El menor haurà de consentir els contractes sobre la seva imatge que el vinculin a la realització d’una prestació personal quan tingui prou maduresa tot i que també hi hauran d’intervenir els seus representants legals per tal de complementar la seva capacitat d’obrar i vetllar per a que el contracte respecti la normativa laboral i civil de protecció del menor i en general no sigui perjudicial per aquest. Quan el menor no tingui prou maduresa per a consentir l’ús de la seva imatge o la realització de la prestació personal, els seus representants podran consentir, amb certs requisits, la intromissió en la seva imatge perquè aixà ho permet excepcionalment la llei orgà nica 1/1982. Tanmateix, s’han de preveure determinades solucions per tal que no es produeixi un perjudici injust.
La segona part enfoca la protecció del menor des de la seva posició com a espectador. El treball té per objecte l'estudi de les mesures de protecció del menor que preveu el nostre ordenament en l'à mbit medià tic, tenint en compte la influència que els mitjans de comunicació exerceixen en el desenvolupament de la seva personalitat i en el seu comportament. Una de les tasques més importants que han d'exercir els mitjans en la nostra societat rau en l'educació del menor. En aquesta tasca és primordial la funció dels poders públics. Per això, es du a terme en primer lloc, una anà lisi exhaustiva dels lÃmits o controls existents en el nostre sistema, de l'activitat medià tica. Un cop detectats els problemes i les deficiències que pateix la nostra legislació en l'à mbit medià tic, s'exposen a continuació, els motius que determinen la necessitat d'una revisió urgent de la mateixa. Per finalitzar amb les propostes de solució que a criteri de les autores, contribuirien a una millora dels mecanismes de protecció del menor en aquest à mbit.La primera parte del trabajo, que está dedicada al menor de edad como protagonista de los medios de comunicación, estudia la forma en que el menor puede ejercer sus derechos de la personalidad en este ámbito, y el contrato sobre su imagen. La segunda parte, que trata al menor de edad como espectador, estudia las medidas de protección existentes en el entorno mediático y sus carencias