86 research outputs found
Neonicotinoid pesticide limits improvement in buzz pollination by bumblebees
Neonicotinoid pesticides have been linked to global declines of beneficial insects such as bumblebees. Exposure to trace levels of these chemicals causes sub-lethal effects, such as reduced learning and foraging efficiency. Complex behaviours may be particularly vulnerable to the neurotoxic effects of neonicotinoids. Such behaviours may include buzz pollination (sonication), in which pollinators, usually bees, use innate and learned behaviours to generate high-frequency vibrations to release pollen from flowers with specialised anther morphologies. This study assesses the effect of field-realistic, chronic exposure to the widely-used neonicotinoid thiamethoxam on the development of sonication buzz characteristics over time, as well as the collection of pollen from buzz-pollinated flowers. We found that the pollen collection of exposed bees improved less with increasing experience than that of unexposed bees, with exposed bees collecting between 47% and 56% less pollen by the end of 10 trials. We also found evidence of two distinct strategies for maximising pollen collection: (1) extensions to the duration of individual buzzes and (2) extensions of the overall time spent buzzing. We find new complexities in buzz pollination, and conclude that the impacts of field-realistic exposure to a neonicotinoid pesticide may seriously compromise this important ecosystem service
An Objective Scatter Index Based on Double-Pass Retinal Images of a Point Source to Classify Cataracts
PURPOSE: To propose a new objective scatter index (OSI) based in the analysis of double-pass images of a point source to rank and classify cataract patients. This classification scheme is compared with a current subjective system. METHODS: We selected a population including a group of normal young eyes as control and patients diagnosed with cataract (grades NO2, NO3 and NO4) according to the Lens Opacities Classification System (LOCS III). For each eye, we recorded double-pass retinal images of a point source. In each patient, we determined an objective scatter index (OSI) as the ratio of the intensity at an eccentric location in the image and the central part. This index provides information on the relevant forward scatter affecting vision. Since the double-pass retinal images are affected by both ocular aberrations and intraocular scattering, an analysis was performed to show the ranges of contributions of aberrations to the OSI. RESULTS: We used the OSI values to classify each eye according to the degree of scatter. The young normal eyes of the control group had OSI values below 1, while the OSI for subjects in LOCS grade II were around 1 to 2. The use of the objective index showed some of the weakness of subjective classification schemes. In particular, several subjects initially classified independently as grade NO2 or NO3 had similar OSI values, and in some cases even higher than subjects classified as grade NO4. A new classification scheme based in OSI is proposed. CONCLUSIONS: We introduced an objective index based in the analysis of double-pass retinal images to classify cataract patients. The method is robust and fully based in objective measurements; i.e., not depending on subjective decisions. This procedure could be used in combination with standard current methods to improve cataract patient surgery scheduling
Effectiveness and safety of generic version of abacavir/lamivudine and efavirenz in treatment naive HIV-infected patients: a nonrandomized, open-label, phase IV study in Cali-Colombia, 2011-2012
Background: Generic drug policies are often associated with concerns about the quality and effectiveness of these
products. Phase IV clinical trials may be a suitable design to assess the effectiveness and safety of generic drugs.
The objective of this study was to describe the effectiveness and the safety of the generic abacavir/lamivudine and
efavirenz in treatment-naïve HIV-infected patients.
Methods: A monocentric, nonrandomized, open-label, phase IV study in treatment naïve HIV-infected patients
18 years or older with indication to receive abacavir/lamivudine and efavirenz were recruited from a program that
provides comprehensive outpatient consultation and continuing care. The primary end-point was to achieve viral load
<40 copies/mL at 12 months after baseline to assess effectiveness. Secondary end-point of the study were 1) to asses
increasing in T-CD4 lymphocytes levels as accompaniment to asses effectiveness, and 2) to assess both gastrointestinal,
skin, and central nervous system symptoms, and lipid profile, cardiovascular risk, renal, and hepatic function as safety
profile. Data were determined at baseline, 3, 6, and 12 months. Close clinical monitoring and pharmaceutical care were
used for data collection. Wilcoxon matched-pairs signed-rank test was used to compare proportions or medians.
Results: Sixty patients were invited to participate in the study; 42 were enrolled and 33 completed the follow-up. Of
the nine patients excluded from the study, only one was withdrawn due to adverse events. At 12 months, 31 of 42
patients (73.8 % in intention-to-treat analysis) achieved a viral load of HIV1 RNA <40 copies/mL. There was a significant
increase (172 cells/mm3) in the median for CD4 T lymphocyte count. The adverse events were mild and met the safety
profile for this antiretroviral regimen, mainly of central nervous system symptoms, skin rash, lipid abnormalities, and an
increase of 2 % in the median of the percentage of cardiovascular risk.
Conclusions: The clinical outcomes of generic version of abacavir/lamivudine and efavirenz in HIV treatment naïve
patients showed the expected safety and effectiveness profile of proprietary ARV drugs.
Trial registration: Registro Público Cubano de Ensayos Clínicos (RPCEC) ID: RPCEC00000202. Registered 19 November
2015.This research was made possible by contribution from the Corporación de
Lucha Contra el SIDA, Cali-Colombia, and Comité para el Desarrollo de la
Investigación (CODI), Universidad de Antioquia, Medellín, Colombia. In
addition, Humax Pharmaceutical S.A. provided the antiretroviral drugs
Thelytokous Parthenogenesis in the Fungus-Gardening Ant Mycocepurus smithii (Hymenoptera: Formicidae)
The general prevalence of sexual reproduction over asexual reproduction among organisms testifies to the evolutionary benefits of recombination, such as accelerated adaptation to changing environments and elimination of deleterious mutations. Documented instances of asexual reproduction in groups otherwise dominated by sexual reproduction challenge evolutionary biologists to understand the special circumstances that might confer an advantage to asexual reproductive strategies. Here we report one such instance of asexual reproduction in the ants. We present evidence for obligate thelytoky in the asexual fungus-gardening ant, Mycocepurus smithii, in which queens produce female offspring from unfertilized eggs, workers are sterile, and males appear to be completely absent. Obligate thelytoky is implicated by reproductive physiology of queens, lack of males, absence of mating behavior, and natural history observations. An obligate thelytoky hypothesis is further supported by the absence of evidence indicating sexual reproduction or genetic recombination across the species' extensive distribution range (Mexico-Argentina). Potential conflicting evidence for sexual reproduction in this species derives from three Mycocepurus males reported in the literature, previously regarded as possible males of M. smithii. However, we show here that these specimens represent males of the congeneric species M. obsoletus, and not males of M. smithii. Mycocepurus smithii is unique among ants and among eusocial Hymenoptera, in that males seem to be completely absent and only queens (and not workers) produce diploid offspring via thelytoky. Because colonies consisting only of females can be propagated consecutively in the laboratory, M. smithii could be an adequate study organism a) to test hypotheses of the population-genetic advantages and disadvantages of asexual reproduction in a social organism and b) inform kin conflict theory
Involvement of Noradrenergic Transmission in the PVN on CREB Activation, TORC1 Levels, and Pituitary-Adrenal Axis Activity during Morphine Withdrawal
Experimental and clinical findings have shown that administration of adrenoceptor antagonists alleviated different aspects of drug withdrawal and dependence. The present study tested the hypothesis that changes in CREB activation and phosphorylated TORC1 levels in the hypothalamic paraventricular nucleus (PVN) after naloxone-precipitated morphine withdrawal as well as the HPA axis activity arises from α1- and/or β-adrenoceptor activation. The effects of morphine dependence and withdrawal on CREB phosphorylation (pCREB), phosphorylated TORC1 (pTORC1), and HPA axis response were measured by Western-blot, immunohistochemistry and radioimmunoassay in rats pretreated with prazosin (α1-adrenoceptor antagonist) or propranolol (β-adrenoceptor antagonist). In addition, the effects of morphine withdrawal on MHPG (the main NA metabolite at the central nervous system) and NA content and turnover were evaluated by HPLC. We found an increase in MHPG and NA turnover in morphine-withdrawn rats, which were accompanied by increased pCREB immunoreactivity and plasma corticosterone concentrations. Levels of the inactive form of TORC1 (pTORC1) were decreased during withdrawal. Prazosin but not propranolol blocked the rise in pCREB level and the decrease in pTORC1 immunoreactivity. In addition, the HPA axis response to morphine withdrawal was attenuated in prazosin-pretreated rats. Present results suggest that, during acute morphine withdrawal, NA may control the HPA axis activity through CREB activation at the PVN level. We concluded that the combined increase in CREB phosphorylation and decrease in pTORC1 levels might represent, in part, two of the mechanisms of CREB activation at the PVN during morphine withdrawal
Capacidade Funcional: estudo prospectivo em idosos residentes em uma instituição de longa permanência
The Short Physical Performance Balance - SPPB has been largely used in researches related to the effects of aging, as a practical and efficient instrument to estimate the physical conditions and screening of elderly people with future disability risk. The SPPB estimates the performance of lower limbs in three aspects: muscle strength, gait and balance, all recognized as fundamental to achieve good quality of life, being accepted as universal indicators to value the health conditions of the elderly. PURPOSE: Analyze the SPPB effectiveness to detect functional capacity changes among institutionalized elderly patients and how it is influenced by cognitive, clinical and global functional variables. METHODS: a prospective study, involving 30 residents of a philanthropic long-term care facility in São Paulo (17 women and 13 men), with ages above 60 years old (43% older than 80 years old) and an average of seven years of residence. After 18 months, these old people were reevaluated and data were compared. RESULTS: Considering the evaluated elderly who had good performance (17%), all of them showed up loss of strength during the research. It was observed that there was an improvement of 16% and 1%, respectively, in the balance and in gait, respectively. There was one or more falls in 47% of them. Comparing the Katz's Index of Independency in the Daily Living, the SPPB was more sensitive to the functional decline, indicating 39%, as compared to the 14% of the loss indentified by Katz. CONCLUSIONS: the data confirm the previous studies, which indicate the functional capacity decline of institutionalized elderly and for the SPPB applicability in the routine of functional attendance of this population.A Short Physical Performance Balance - SPPB vem sendo utilizada largamente em pesquisas sobre o envelhecimento, como instrumento prático e eficaz na avaliação do desempenho físico e rastreamento de idosos com riscos futuros de incapacidades. Ela avalia o desempenho de membros inferiores em três aspectos: força muscular, marcha e equilíbrio, reconhecidos como componentes fundamentais para a qualidade de vida, sendo aceitos como indicadores universais do estado de saúde em idosos. OBJETIVO: Analisar a eficácia da SPPB em detectar alterações na capacidade funcional do idoso institucionalizado e como esta é influenciada pelas variáveis cognitivas, clínicas e funcionais globais. METODOLOGIA: estudo prospectivo do qual participaram 30 residentes de uma instituição de longa permanência, filantrópica, em São Paulo (17 mulheres e 13 homens), com idades acima de 60 anos ou mais (43% maiores de 80 anos) e média de sete anos de residência. Após 18 meses, estes idosos foram reavaliados e os dados, comparados. RESULTADOS: Dos idosos avaliados que obtiveram bom desempenho (17%), todos apresentaram perda de força ao longo do seguimento. Quanto ao equilíbrio e marcha, notou-se melhora de 16% e 1%, respectivamente. Apresentaram uma ou mais quedas, 47% dos sujeitos. Quando comparada com o Índex de Independência nas Atividades de Vida Diária de Katz, a SPPB se mostrou mais sensível em relação ao declínio funcional, apontando 39% em comparação aos 14% de perda identificada pelo Katz. CONCLUSÃO: os dados corroboram estudos anteriores, que apontam para o declínio da capacidade funcional de idosos institucionalizados e para a aplicabilidade da SPPB na rotina de acompanhamento funcional dessa população.Universidade Federal de São Paulo (UNIFESP) Curso de Especialização em Reabilitação GerontológicaLar Escola São Francisco Centro de Reabilitação Setor de Reabilitação GerontológicaUniversidade de São Paulo Faculdade de Medicina Hospital das ClínicasUNIFESP, Curso de Especialização em Reabilitação GerontológicaSciEL
Development of the serotonergic cells in murine raphe nuclei and their relations with rhombomeric domains
Invited Commentary: Broadening the Evidence for Adolescent Sexual and Reproductive Health and Education in the United States
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study
Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk
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