Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.776
Filtrar
1.
Chest ; 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32006591

RESUMO

Smoking continues to be a burden to economies and healthcare systems across the world. One proposed solution to the problem has been e-cigarettes; however, as a relatively new product in the market, little is known about their potential health impacts. Furthermore, e-cigarettes continue to evolve at a rapid rate, making it necessary to regularly review and synthesize available studies. Whilst e-cigarettes are marketed as a smoking cessation tool by some manufacturers, the reality is that many non-smokers, including youth, are using them. In this review we focus on two major demographics - smokers and non-smokers, and evaluate the most recent data (2018-2019) regarding the potential health effects of e-cigarettes. We assessed peer-reviewed studies on health impacts of e-cigarettes with particular focus on common questions asked by policy makers, clinicians, and scientists: 1. What are the effects of e-cigarettes compared with air/not-smoking?; 2. Is there any direct evidence of harm or benefit to humans?; 3. Is there a risk from second-hand exposure?; 4. What are the risks and/or benefits of e-cigarettes compared with tobacco cigarette use?; 5. Are there risks or benefits to specific populations - people with COPD or asthma, and pregnant women (and their offspring)?; 6. What are the effects of flavoring chemicals?; 7. What are the effects of including nicotine in e-liquids?; 8. How often is nicotine-level labelling incorrect? and 9. What are the risks when e-cigarettes explode?

2.
J Vet Cardiol ; 27: 34-53, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32032923

RESUMO

INTRODUCTION: Efficacy of renin-angiotensin-aldosterone system (RAAS) blockade using angiotensin-converting enzyme inhibitors (ACEi) in dogs with preclinical myxomatous mitral valve disease (MMVD) is controversial. HYPOTHESIS: Administration of spironolactone (2-4 mg q 24 h) and benazepril (0.25-0.5 mg q 24 h) in dogs with preclinical MMVD, not receiving any other cardiac medications, delays the onset of heart failure (HF) and cardiac-related death. Moreover, it reduces the progression of the disease as indicated by echocardiographic parameters and level of cardiac biomarkers N-terminal pro brain natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI). ANIMALS: 184 dogs with pre-clinical MMVD and left atrium-to-aortic root ratio (LA:Ao) ≥1.6 and normalized left ventricular end-diastolic diameter (LVEDDn) ≥1.7. METHODS: This is a prospective, randomized, multicenter, single-blinded, placebo-controlled study. Primary outcome variable was time-to-onset of first occurrence of HF or cardiac death. Secondary end points included effect of treatment on progression of the disease based on echocardiographic and radiographic parameters, as well as variations of NT-proBNP and cTnI concentrations. RESULTS: The median time to primary end point was 902 days (95% confidence interval (CI) 682-not available) for the treatment group and 1139 days (95% CI 732-NA) for the control group (p = 0.45). Vertebral heart score (p = 0.05), LA:Ao (p < 0.001), LVEDDn (p < 0.001), trans-mitral E peak velocity (p = 0.011), and NT-proBNP (p = 0.037) were lower at the end of study in the treatment group. CONCLUSIONS: This study failed in demonstrating that combined administration of spironolactone and benazepril delays onset of HF in dogs with preclinical MMVD. However, such treatment induces beneficial effects on cardiac remodeling and these results could be of clinical relevance.

3.
Theriogenology ; 145: 94-99, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32007637

RESUMO

Bull testes must be 4-5 °C below body temperature, with testicular warming more likely to cause poor-quality sperm in Bos taurus (European/British) versus Bos indicus (Indian/zebu) bulls. Despite a long-standing dogma that testicular hyperthermia causes hypoxia, we reported that increasing testicular temperature in bulls and rams enhanced testicular blood flow and O2 delivery/uptake, without hypoxia. Our objective was to determine effects of short-term testicular hyperthermia on testicular blood flow, O2 delivery and uptake and evidence of testicular hypoxia in pubertal Angus (B. taurus) and Nelore (B. indicus) bulls (nine per breed) under isoflurane anesthesia. As testes were warmed from 34 to 40 °C, there were increases (P < 0.0001, but no breed effects) in testicular blood flow (mean ± SEM, 9.59 ± 0.10 vs 17.67 ± 0.29 mL/min/100 g, respectively), O2 delivery (1.79 ± 0.06 vs 3.44 ± 0.11 mL O2/min/100 g) and O2 consumption (0.69 ± 0.07 vs 1.25 ± 0.54 mL O2/min/100 g), but no indications of testicular hypoxia. Hypotheses that: 1) both breeds increase testicular blood flow in response to testicular warming; and 2) neither breed has testicular hypoxia, were supported; however, the hypothesis that the relative increase in blood flow is greater in Angus versus Nelore was not supported. Although these were short-term increases in testicular temperature in anesthetized bulls, results did not support the long-standing dogma that increased testicular temperature does not increase testicular blood flow and an ensuing hypoxia is responsible for decreases in motile, morphologically normal and fertile sperm.

4.
J Helminthol ; 94: e122, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31964430

RESUMO

Eurytrema coelomaticum is a digenean flatworm of ruminants that is the causative agent of eurytrematosis, a disease of veterinary health concern. Although modern techniques of morphological analysis have provided new insights about the morphology and anatomy of parasitic helminths, most studies on E. coelomaticum adults are based on conventional light microscopy. In the present study, a combined approach using brightfield, fluorescence, confocal and scanning electron microscopies (SEMs), together with the cryofracture technique, have updated morphological data on E. coelomaticum recovered from cattle in Rio de Janeiro State, Brazil. Light microscopy confirmed the presence of several structures present in the current description, such as suckers, pharynx, oesophagus, intestinal bifurcation and the cirrus-sac. Fluorescence stereomicroscopy revealed for the first time the cubic crystal protein inclusions in the forebody, which were further detailed by confocal and SEMs. Confocal microscopy provided detailed information of the muscular architecture associated with the attachment structures (suckers), digestive system (pharynx and oesophagus), egg-forming complex (ovary, Mehlis' gland and Laurer's canal) and male reproductive system, which are similar to those found in other digenean flukes. SEM images of cryofractured parasites showed mucus and developing eggs within uterine loops. It was demonstrated that the combination of advanced tools generated complementary information, confirming the importance of experimental morphology in parasitology. Therefore, the knowledge of the adult structural organization of E. coelomaticum was improved and this work has contributed to propose new morphological criteria to evaluate the effects of antiparasitic drugs on flukes of medical and veterinary importance.

5.
7.
Plant Cell Rep ; 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31915913

RESUMO

KEY MESSAGE: An efficient and improved transformation method for functional genetics studies in S. italica, being a boon for the Setaria scientific community and for crop improvement. Foxtail millet (Setaria italica) is a short life cycle C4 plant, with sequenced genome, and a potential model plant for C4 species. S. italica is also important on a global food security and healthiness context due to its importance in arid and semi-arid areas. However, despite its importance, there are just few transformation protocols directed to this species. The current protocols reached about 5.5-9% of efficiency, which do not make it a valuable model organism. Different types of explants were used in the above mentioned methods, such as immature and mature inflorescence and shoot apex. However, these techniques have many limitations, such as unavailability of explants throughout the year and a crucial, laborious and considerable time-consuming selection. Aiming a simplified and efficient methodology, we adopted dry mature seeds as explants, which are available in abundance, are constant along the year and well responsive to tissue culture, in addition to a differentiated approach that reaches on an average 19.2% transformation efficiency of S. italica. Thus, we propose a protocol that optimizes the transformation efficiency of this cereal crop allowing a high increase on transformation and regeneration rates. Our transformation protocol provides an interesting tool for Setaria community research as well as enables new strategies for breeding enhanced productivity in the species.

8.
Mol Hum Reprod ; 26(1): 1-13, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31814009

RESUMO

The unfolded protein response (UPR) is a conserved and essential cellular pathway involved in protein quality control that is activated in response to several cellular stressors such as diseases states, ageing, infection and toxins. The cytosol, endoplasmic reticulum (ER) and mitochondria are continuously exposed to new proteins and in situations of aberrant protein folding; one of three lines of defence may be activated: (i) heat-shock response, (ii) mitochondrial UPR and (iii) ER UPR. These pathways lead to different signal transduction mechanisms that activate or upregulate transcription factors that, in turn, regulate genes that increase the cell's ability to correct the conformation of poorly folded proteins or, ultimately, lead to apoptosis. Despite the recent progress in understanding such biological processes, few studies have focused on the implications of the UPR in male infertility, highlighting the need for a first approach concerning the presence of these components in the male reproductive system. In testis, there is a high rate of protein synthesis, and the UPR mechanisms are well described. However, the presence of these mechanisms in spermatozoa, apparently transcriptionally inactive cells, is contentious, and it is unclear how sperm cells deal with stress. Here, we review current concepts and mechanisms of the UPR and highlight the relevance of these stress response pathways in male fertility, especially the presence and functional activation of those components in male germinal cells and spermatozoa.

9.
Zygote ; 28(1): 32-36, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31601279

RESUMO

The present study evaluated the effect of knockout serum replacement (KSR), fetal bovine serum (FBS) and bovine serum albumin (BSA) on the viability and growth of bovine secondary follicles cultured in vitro for 12 days. To this end, secondary follicles were isolated (185-202 µm) and cultured in vitro in TCM-199+ medium supplemented with KSR (5% and 10%), FBS (5% and 10%) or BSA (3 mg/ml) at 38.5°C with 5% CO2 in air. Follicular diameters were evaluated on days 0, 4, 8 and 12. After 12 days of culture, follicular survival analysis was performing by using calcein-AM and ethidium homodimer. Before and after culture, follicles were fixed in paraformaldehyde for histological evaluation. Follicular diameter at different days of culture were compared using the Kruskal-Wallis test, while the percentages of viable follicles were analyzed by chi-squared test (P < 0.05). Results showed that follicles cultured in the presence of KSR at both concentrations presented higher follicular survival rates than those cultured in control medium alone or supplemented with FBS or BSA. Conversely, the presence of KSR, BSA or FBS did not increase follicular diameter after 12 days of culture. Histology analysis showed that, among the tested treatments, follicles cultured in the presence of KSR had preserved rounded oocytes, juxtaposed granulosa cells and intact basal membrane. In conclusion, supplementation of culture medium with KSR increases the follicular survival of bovine secondary follicles cultured in vitro.

10.
Animal ; 14(1): 215-222, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31203827

RESUMO

The enrichment of meat with selenium is important to improve the intake of selenium by humans. The effects of supranutritional doses of sodium selenite or selenium-enriched yeast on performance, carcass characteristics and meat quality were evaluated using 63 Nellore cattle in a completely randomized design with two sources (sodium selenite and selenium-enriched yeast), three levels (0.3, 0.9 and 2.7 mg Se/kg DM) and control treatment (without addition of selenium). Final body weight (BW), average daily gain, dry matter intake and gain to feed ratio (G : F) at the end of 84 days of supplementation were not influenced by treatments (P>0.05). Values of pH, ribeye area, back fat thickness and marbling score were also not influenced by treatments ( P>0.05). Dressing percentage was greater (P=0.02) in Nellore cattle supplemented with organic Se (58.70%) compared to animals supplemented with inorganic Se (57.94%). Hot carcass weight increased ( P=0.05) with the increasing of Se levels in the diet. Colour, shear force (SF), cooking and drip loss remained unchanged ( P>0.05); however thiobarbituric acid reactive substances was 15.51% higher with inorganic Se compared with organic Se. The selenium concentration in the meat of animals receiving organic selenium was higher ( P<0.001) than that of animals receiving sodium selenite, at all levels (0.3; 0.9 and 2.7 mg/kg DM). The meat of animals receiving 2.7 mg of organic Se/kg of DM presented concentration of 372.7 µg Se/kg in the L.dorsi muscle, and the intake of 150 g of this meat by humans provides approximately 100% of the recommended Se intake (55 µg Se/day for adults). Therefore, the use of supranutritional doses of 2.7 mg Se/kg of DM, regardless of source, is a way of naturally producing selenium-enriched meat without compromising performance, carcass characteristics and quality of Nellore bovine meat.

11.
Theriogenology ; 142: 284-290, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31711701

RESUMO

The aims of this study were to investigate the effects of epidermal growth factor (EGF) and progesterone on the development, viability and the gene expression of bovine secondary follicle culture in vitro for 18 days. Secondary follicles (∼0.2 mm) were isolated from ovarian cortex and individually cultured at 38.5 °C, with 5% CO2 in air, for 18 days, in TCM-199+ (n = 63) alone (control medium) or supplemented with 10 ng/mL progesterone (n = 64), 10 ng/mL EGF (n = 61) or both EGF and progesterone (n = 66). The effects of these treatments on growth, antrum formation, viability, ultrastructure and mRNA levels for GDF-9, c-MOS, H1foo and cyclin B1 were evaluated, significantly different (p < 0.05). The results showed that there was a progressive increase in follicular diameter in all treatments, but only follicles cultured in medium supplemented with EGF had increased significantly in diameter when compared to follicles cultured in the control medium at the end of the culture period, significantly different (p < 0.05). A positive interaction between EGF and progesterone was not observed. In addition, the presence of EGF, progesterone or both in culture medium did not influence the rate of follicle survival and antrum formation. However, the presence of only progesterone in cultured medium increased the expression of mRNAs for GDF9 and cyclin B1 in oocytes. EGF also significantly increased the levels of mRNAs for cMOS and GDF9 when compared to follicles cultured in control medium. Ultrastructural analyzes showed that cultured follicles in all treatments maintained the integrity of granulosa cells. In conclusion, the EGF promotes the development of secondary follicles cultured in vitro for 18 days and increases the expression of cMOS and GDF9, while progesterone alone or in association with EGF have not a positive effect on follicular growth. However, progesterone increases the expression of GDF9 and cyclin B1 in oocytes.

13.
Sci Rep ; 9(1): 18755, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31822738

RESUMO

A previously unreported tetragonal phase has been discovered in a epitaxially strained GdMnO3 thin films deposited on (001)-oriented SrTiO3 substrates by radio frequency (RF) magnetron sputtering. The tetragonal axis of the films grown up to a 35 nm thickness is perpendicular to the film surface and the basal lattice parameters are imposed by the cubic structure of the substrate. Furthermore, the emergence of a spontaneous electric polarization below ~32 K points to the stabilization of an improper ferroelectric phase at low temperatures, which is not observed in bulk GdMnO3. This work shows how strain engineering can be used to tailor the structure and properties of strongly correlated oxides.

14.
Neotrop Entomol ; 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31802413

RESUMO

Anastrepha obliqua (Macquart) is an agricultural pest of wide geographic distribution infesting a vast list of host species in America. However, little is known about the past geographic distribution of this species. In this study, we investigated the potential past and current distribution of species in South America. In this sense, the MaxEnt algorithm was used to model the ecological niche of the species in the past (Last Interglcial Maximum; Last Glacial Maximum) and current periods. The results suggested that under the current climatic conditions, A. obliqua showed high environmental suitability to become established in most South American countries, especially in Brazil. The lowest suitability indices were observed in Chile, Argentina, and Uruguay. The past analysis for Last Glacial Maximum revealed that there was no significant change in the distribution potential of the species when compared to the current model; however, in the Last Interglacial Maximum period, there was a large reduction in the areas of suitability for the species when compared to the current and Last Glacial Maximum distribution models. The analysis also revealed vast areas of refuges for the species mainly on the coast of Brazil, as well as Venezuela, Bolivia, Guyana, and Surinam. The results presented here may be useful for future phylogeographical studies in order to test if the refuge areas concentrate greater genetic diversity for this species. In addition, our study provides important information for understanding the current dynamics of A. obliqua, which may be useful for control programs in places where this species can become a pest.

15.
Lasers Med Sci ; 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31768691

RESUMO

To date, there is no compilation of evidence-based information associating photobiomodulation effect and salivary glands. This systematic review aims to assess photobiomodulation effect of low intensity laser on salivary glands in the presence of systemic diseases. MEDLINE databases were searched in duplicate through December 2018. In vivo studies and clinical trials were included if photobiomodulation was performed in salivary glands of animal (rat or mice) or human in the presence of systemic disease. The methodological quality was assessed in duplicate using the modified Newcastle-Ottawa scale (NOS). Search strategy identified 483 potentially eligible articles, and 449 were included. The Boolean search naturally leads to a high amount of works the majority of which were excluded because the analysis of the title and abstract demonstrated it was not focusing on PBM. Only 34 studies were selected for the full-text analysis, of which 5 were excluded due to non-use of photobiomodulation, 4 due to lack of control group, 2 because they were studies of cell cultures and 1 because they did not have the total of animals used. Thus, 21 papers were included for the critical evaluation of the impact of photobiomodulation on the major salivary glands; the studies used rats (n = 10) and humans (n = 11). Although studies reported an increase in the salivary rate, decrease in pain, and increase in quality of life after the PBM, the lack of standards for the application of light and reporting of the parameters, make it hard to reproduce the results. This topic is still in need for further research.

16.
Nutr Neurosci ; : 1-12, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757196

RESUMO

Purpose: Dysregulation of glutamatergic neurotransmission (GN) is linked to sympathetic-respiratory overactivity and hypertension. We investigated whether maternal protein restriction is able to alter GN into the nucleus of the solitary tract (NTS) in adult offspring.Methods: Wistar rat dams were fed with control (NP; 17% protein) or low-protein (LP; 8% protein) diet during pregnancy and lactation, and their offspring were evaluated at 70-90d old. Direct measurements of mean arterial pressure (MAP), heart rate (HR), respiratory frequency (RF) and respiratory (RV) and cardiac (CV) variabilities were assessed in consciousness. The evaluation of GN into NTS over cardiovascular system were assessed by microinjections of unilateral glutamate (L-glu 0.5 nmol/100nL) and bilateral kynurenic acid (Kyn 2.5 nmol/50nL). The NP and LP groups were compared using unpaired Student's t-test where p < 0.05 was considered significant.Results: The LP exhibited higher MAP at rest (p = 0.03) and after L-glu microinjection (p = 0.04), as well as an increase over HR after Kyn microinjection when compared to the NP (p = 0.049). In the RV, the LP group showed an increase of the component-standard deviation 1 (p = 0.037) at rest. In the CV, the LP presented an increase of the low frequency (LF) component of the pulse interval (PI) (p = 0.034), a decrease of high frequency (HF) of the PI (p = 0.034), beyond an increased LF/HF ratio of the PI (p = 0.027) when compared to the NP. The kynurenic acid microinjection did not produce changes in RV or CV (p > 0.05).Conclusions: Altered GN into the NTS may contribute to augmented blood pressure in protein-restricted offspring.

17.
J Endocrinol Invest ; 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31686401

RESUMO

PURPOSE: Turner syndrome (TS) patients display considerable immune misregulation, and it is hypothesized that Vitamin D (VTD) activity may fluctuate according to Vitamin D receptor (VDR) polymorphisms and/or expression profile. To uncover a possible relationship between VDR genotype and clinical conditions in TS patients, we investigated two functional VDR variants (Cdx-2 and FokI) for allele and genotype frequencies, as well as expression profile in TS individuals versus healthy controls (HC). METHODS: We performed a genetic association study including 100 TS patients and 116 HC. Genotyping for VDR Cdx-2 G > A (rs11568820) and FokI C > T (rs2228570) was performed using Taqman Genotyping Assays. VDR gene expression was also evaluated in 15 TS and 15 HC, using fluorogenic probes by qPCR. Statistical analyses were performed using nonparametric Mann-Whitney test, with a 5% significance level (p < 0.05) to uncover differences between groups. In addition, we investigated whether shifted VDR mRNA levels were associated with Cdx-2 and FokI variants in TS patients. RESULTS: We detected a significantly higher frequency of T allele (p = 0.006) as well as T/T genotype (p = 0.01) for FokI in TS patients when compared to HC. When assessing VDR expression, we identified a downregulation in TS woman (- 2.84 FC) versus HC (p < 0.001). Furthermore, C/T (11.24 FC; p = 0.01) and T/T (9.20 FC; p = 0.01) FokI genotypes were upregulated when compared to C/C reference genotype. CONCLUSION: TS patients show different distribution of FokI polymorphism. Downregulation of VDR gene expression may contribute to immunological imbalance in TS.

18.
J Virus Erad ; 5(3): 174-177, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31700667

RESUMO

This report describes a case of juvenile myelomonocytic leukaemia (JMML) on a background of both perinatally acquired HIV infection and congenital cytomegalovirus, and management of antiretroviral therapy during haematopoietic stem cell transplant. Peripheral blood HIV viral load remained below the lower limit of detection throughout and following transplant and is currently <20 RNA copies/mL. The child is currently in remission from JMML, but HIV DNA remains detectable despite myeloablative conditioning and sustained plasma HIV viral suppression.

19.
J Virus Erad ; 5(3): 174-177, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31700668

RESUMO

This report describes a case of juvenile myelomonocytic leukaemia (JMML) on a background of both perinatally acquired HIV infection and congenital cytomegalovirus, and management of antiretroviral therapy during haematopoietic stem cell transplant. Peripheral blood HIV viral load remained below the lower limit of detection throughout and following transplant and is currently <20 RNA copies/mL. The child is currently in remission from JMML, but HIV DNA remains detectable despite myeloablative conditioning and sustained plasma HIV viral suppression.

20.
Sci Adv ; 5(10): eaaw6619, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31692661

RESUMO

Lead-based organic-inorganic hybrid perovskite (OIHP) solar cells can attain efficiencies over 20%. However, the impact of ion mobility and/or organic depletion, structural changes, and segregation under operating conditions urge for decisive and more accurate investigations. Hence, the development of analytical tools for accessing the grain-to-grain OIHP chemistry is of great relevance. Here, we used synchrotron infrared nanospectroscopy (nano-FTIR) to map individual nanograins in OIHP films. Our results reveal a spatial heterogeneity of the vibrational activity associated to the nanoscale chemical diversity of isolated grains. It was possible to map the chemistry of individual grains in CsFAMA [Cs0.05FA0.79MA0.16Pb(I0.83Br0.17)3] and FAMA [FA0.83MA0.17Pb(I0.83Br0.17)3] films, with information on their local composition. Nanograins with stronger nano-FTIR activity in CsFAMA and FAMA films can be assigned to PbI2 and hexagonal polytype phases, respectively. The analysis herein can be extended to any OIHP films where organic cation depletion/accumulation can be used as a chemical label to study composition.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA