2,069 research outputs found
Novel pharmacological actions of Trequinsin Hydrochloride improve human sperm cell motility and function
Background and purposeAsthenozoospermia is a leading cause of male infertility, but the development of pharmaceuticals to improve sperm motility has been hindered by the lack of effective screening platforms and knowledge of suitable molecular targets. We have demonstrated that a high throughput screening (HTS) strategy in conjunction with established in vitro tests can identify and characterise the action of compounds that improve sperm motility. The study aimed to apply HTS to identify new compounds from a novel small molecule library that increase intracellular calcium, [Ca2+]I, promote human sperm cell motility and systemically determine the mechanism of action. Experimental approach A validated HTS fluorometric [Ca2+]i assay was used to screen an in-house library of compounds. Trequinsin hydrochloride (a phosphodiesterase 3 inhibitor) was selected for detailed molecular (plate reader assays, electrophysiology and cyclic nucleotide measurement) and functional (motility and acrosome reaction) testing in sperm from healthy volunteer donors and, where possible, patients. Key resultsThe fluorometric analysis identified Trequinsin as an efficacious agonist of [Ca2+]i, although less potent than progesterone (P4). Functionally, Trequinsin significantly increased cell hyperactivation and penetration into viscous medium in all donor sperm samples and cell hyperactivation in 22/25 (88%) patient sperm samples. The Trequinsin-induced [Ca2+]i response was cross-desensitised consistently by prostaglandin E1 but not with P4. Whole-cell patch clamp electrophysiology confirmed that Trequinsin activates CatSper and partially inhibits potassium channel activity. Trequinsin also increases intracellular cGMP. Conclusion and Implications Trequinsin exhibits a novel pharmacological profile in human sperm and may be a suitable lead compound for the development of new pharmaceuticals to improve patient sperm function and fertilisation potential
Precipitation reaction in alpha-Cu-Al-Ag alloys
The Ag-rich precipitates formation reaction in the Cu-9.22%at. Al-4.66%at. Ag, Cu-9.31%at. Al-5.83%at. Ag and Cu-9.37%at. Al-7.08%at. Ag alloys was studied using microhardness change measurements with temperature and time, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The results indicated that the Ag-rich phase formation is an interface controlled process with a zero-order mechanism, due to the amount of unsolved Ag that makes the precipitation reaction rate independent of Ag concentration.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)UNIFESP Departamento de Ciências Exatas e da TerraUNESP Instituto de Química Departamento de Físico-QuímicaUNIFESP, Depto. de Ciências Exatas e da TerraSciEL
Effect Of Fixative Type And Fixation Time On The Morphology Of Equine Preantral Ovarian Follicles
The aim of this study was to investigate the efficacy of the tissue fixatives Bouin, Carnoy and 10% Formaldehyde in equine ovarian fragments. Ovaries (n=4) from mares of mixed breeds were obtained at a local slaughterhouse and transported at 20 oC in a thermo container. Immediately after collection, the ovaries were washed with a modified PBS solution (CultilabR, Campinas-SP, Brazil) and divided into nine fragments with approximately 5x5x1 mm, removed from the parenchyma of each ovary. The ovarian fragments were then immersed in three different fixatives, Bouin (B) Carnoy (C) or 10% Formaldehyde (F) for 6, 12 or 24 hours. Each fragment was individually immersed in a 20 mL tube containing 20 times the volume of fixative solution. After this period, the fragments were held in 70% ethanol for 24 hours. Each procedure was performed in four replicates. For histological analysis, the specimens were dehydrated in increasing concentrations of alcohol, submitted to diaphanization in xylol and embedded in paraffin. Serial sections of 5 'Êm were made with the use of a rotating microtome (LeicaR type, Wetzlar, Germany), followed by slide mounting and staining with periodic acid-Schiff (PAS) and hematoxylin. A total of 540 slides with 1,620 sections were evaluated, which contained 465 preantral follicles that were classified as normal or degenerated. Follicles were considered as degenerated when presented at least one of the following aspects: cytoplasm retraction, pyknotic nucleus, cytoplasmic vacuoles, displacement of granulosa cells and/or disruption of the basal membrane. A logistic regression test was used for statistical analysis, and differences were considered significant when P<0.05. The Carnoy fixative, when used for 24 hours, provided the best conditions of morphological integrity (53.3%; 32/60) compared to all others, and the use of Boiun for 24 hours was considered the worst treatment (19.1%; 9/47). The other treatments lead to the following results: C12h 50% (30/60), C6 H 40% (24/60), F24h 37.8% (17/45), F12h 35.1% (13/37), F6h 32% (16/50), B12h 30.5% (18/59) and B6h 24.4% (11/45). Therefore, we suggest that fixation of equine ovarian tissue with Carnoy for 24 hours is the most suitable protocol for morphological preservation of pre-antral follicles.37124325
Field theoretic description of charge regulation interaction
In order to find the exact form of the electrostatic interaction between two
proteins with dissociable charge groups in aqueous solution, we have studied a
model system composed of two macroscopic surfaces with charge dissociation
sites immersed in a counterion-only ionic solution. Field-theoretic
representation of the grand canonical partition function is derived and
evaluated within the mean-field approximation, giving the Poisson-Boltzmann
theory with the Ninham-Parsegian boundary condition. Gaussian fluctuations
around the mean-field are then analyzed in the lowest order correction that we
calculate analytically and exactly, using the path integral representation for
the partition function of a harmonic oscillator with time-dependent frequency.
The first order (one loop) free energy correction gives the interaction free
energy that reduces to the zero-frequency van der Waals form in the appropriate
limit but in general gives rise to a mono-polar fluctuation term due to charge
fluctuation at the dissociation sites. Our formulation opens up the possibility
to investigate the Kirkwood-Shumaker interaction in more general contexts where
their original derivation fails.Comment: 12 pages, 9 figures, submitted to EPJ
Effects of dual blockade in heart failure and renal dysfunction: Systematic review and meta-analysis
OBJECTIVE: The effect of dual renin-angiotensin system (RAS) inhibition in heart failure (HF) is still controversial. Systematic reviews have shown that dual RAS blockade may reduce mortality and hospitalizations, yet it has been associated with the increased risk of renal dysfunction (RD). Surprisingly, although RD in patients with HF is frequent, the effect of combining RAS inhibitors in HF patients with RD has never been studied in a meta-analysis. METHODS: A systematic review and meta-analysis of randomized clinical trials involving HF patients with RD who received dual blockade analyzing death, cardiovascular (CV) death or HF hospitalization, and adverse events. RESULTS: Out of 2258 screened articles, 12 studies were included (34,131 patients). Compared with monotherapy, dual RAS inhibition reduced hazard ratio of death to 0.94 (p=0.07) and significantly reduced CV death or HF hospitalization to 0.89 (p=0.0006) in all individuals, and to 0.86 (p=0.005) in patients with RD and to 0.91 (p=0.04) without RD. Nevertheless, dual RAS blockade significantly increased the risk of renal impairment (40%), hyperkalemia (44%), and hypotension (42%), although discontinuation of treatment occurs only in 3.68% versus 2.19% (p=0.00001). CONCLUSIONS: Dual RAS inhibition therapy reduces the risk of CV death or HF hospitalization. However, cautions monitoring for specific adverse events may be warranted
Sampling procedures for spittlebug adults in pastures of Brachiaria decumbens
Foi conduzido um estudo sobre amostragem de adultos de cigarrinhas em pastagens de Brachiaria decumbens para se determinar o melhor número de batidas em uma amostra de rede entomológica. Considerando-se a variação relativa (EP/X) X 100, e o número total de batidas na amostragem, encontra-se 10 batidas/amostra ser melhor do que 5, 20 ou 40. O número de amostras necessárias para determinado nível de variação relativa nas populações de cigarrinhas > 16 adultos/10 batidas foi o mesmo, ao passo que, nas densidades 16 spittlebug adults/10 sweeps remained the same, whereas at densities < 16, the number increased inversely. A regression model to convert relative estimates obtained by sweep-net method to the absolute estimate was presented. Considering the degree of precision and the time spent in sampling, the sweep-net method was superior to cage method. The distribution pattern of numbers of spittlebug adults in samples of 10 sweep-net sweeps, generally fitted the Poisson series. A sequential plan presented here would reduce the sampling time over the conventional (fixed sample numbers) sampling
Recharge assessment in the context of expanding agricultural activity: Urucuia Aquifer System, western State of Bahia, Brazil
Groundwater recharge rate estimation is crucial to sustainable development of aquifers in intensely pumped regions, such as the Urucuia Aquifer System (UAS). A sedimentary aquifer in Western Bahia, Brazil, that underlies one of the major agricultural areas of the country where there has been major growth of irrigated areas. This study seeks to evaluate the recharge component of the water budget in the UAS area, based on three complementary techniques. The double-ring infiltrometer test was used to evaluate surface infiltration capacity, an important control on recharge. Water level data from wells (2011–2019 period, 19 wells) in the Brazilian Geological Survey’s Integrated Groundwater Monitoring Network (RIMAS-CPRM) was used to estimate the aquifer recharge using the water table fluctuation (WTF) method. Additionally, this study used the Soil Water Assessment Tool (SWAT) model in two selected sub-basins to estimate deep recharge from the surface hydrological data. The results of the infiltrometer tests show a notable difference in the infiltration rates between the natural vegetation zones and cropped areas. The WTF and SWAT simulations results suggest similar ranges of recharge rate (an average of 24% of precipitation, in both methods). Results of the study indicate equivalence of these methods to estimate the recharge in sedimentary unconfined aquifers as UAS
First report of anthracnose of Capsicum Chinense in Brazil caused by Colletotrichum brevisporum
Fruit of “yellow lantern” chili pepper (Capsicum chinense L.) with typical symptoms of anthracnose were observed in the city of Manaus in 2008 and Manacapuru in 2014, in Amazonas state, Brazil. The symptoms initially consisted of small dark-brown lesions, circular, depressed, with defined edges, progressing to the center and becoming gray to black, with concentric circles. Losses of up to 100% have occurred in some plantings. Isolation of the fungus was carried out from masses of spores present on the fruit lesions. Colonies were grown on potato dextrose agar (PDA) at 25°C and 12-h photoperiod. Monosporic cultures were obtained and the isolates were deposited in the Microorganisms Culture Collection of the National Institute of Amazonian Research, Manaus, Brazil (INPA 1858 and INPA 2800). After 7 days on PDA, single spore colonies had a cottony appearance and the color ranged from white to brownish, with orange-colored masses of conidia. Conidia were hyaline, aseptate, cylindrical with rounded ends, and measured 10.2 to 17.7 µm in length × 3.3 to 5.6 µm in width. Appressoria formed were dark-brown in color, irregularly shaped or lobate, and measured 5.9 to 12.0 µm in length and 5.5 to 8.9 µm in width. Partial sequences of actin (ACT) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were amplified and comparted to GenBank accession nos. KU315567 and KX878886 for ACT and KU315572 and KX878887 for GAPDH. Bayesian inference analyses performed with concatenated gene sequences showed that the isolate INPA 1858 and INPA 2800 clustered with the ex-type specimen of Colletotrichum brevisporum (BCC 38876) in a clade with high support (posterior probability = 1). Pathogenicity tests with isolates INPA 1858 and INPA 2800 were conducted on healthy chili peppers using the wound inoculation method by droplet (106 conidia/ml) on the fruit surface (Lin et al. 2002). Pathogenicity tests were done with 10 fruit per isolate (INPA 1858 and INPA 2800) replicated three times. The controls were inoculated with sterile water. Typical symptoms of anthracnose were observed 7 days post inoculation, while the controls did not show any symptoms. The fungus C. brevisporum was recovered from the inoculated chili peppers, thereby confirming Koch’s postulates. C. brevisporum was described in Thailand causing symptoms in Neoregalia sp. and in Pandanus pygmaeus (Noireung et al. 2012), in Korea in Lycium chinense (Paul et al. 2014), and in Brazil in Carica papaya and Sechium edule (Bezerra et al. 2016; Vieira et al. 2013). To our knowledge, this is the first report of C. brevisporum on C. chinense fruits in Brazil. © 2017, American Phytopathological Society. All rights reserved
Controlling quantum entanglement through photocounts
We present a protocol to generate and control quantum entanglement between
the states of two subsystems (the system ) by making measurements on
a third subsystem (the monitor ), interacting with . For
the sake of comparison we consider first an ideal, or instantaneous projective
measurement, as postulated by von Neumann. Then we compare it with the more
realistic or generalized measurement procedure based on photocounting on . Further we consider that the interaction term (between and
) contains a quantum nondemolition variable of and discuss
the possibility and limitations for reconstructing the initial state of from information acquired by photocounting on .Comment: 12 pages, 3 figures, accepted for publication in Phys. Rev
- …