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1.
J Nanobiotechnology ; 22(1): 254, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755625

RESUMO

AIM: The antifungal activity was studied on sessile and persister cells (PCs) of Candida tropicalis biofilms of gold nanoparticles (AuNPs) stabilized with cetyltrimethylammonium bromide (CTAB-AuNPs) and those conjugated with cysteine, in combination with Amphotericin B (AmB). MATERIALS/METHODS: The PC model was used and synergistic activity was tested by the checkerboard assay. Biofilms were studied by crystal violet and scanning electron microscopy. RESULTS/CONCLUSIONS: After the combination of both AuNPs and AmB the biofilm biomass was reduced, with significant differences in architecture being observed with a reduced biofilm matrix. In addition, the CTAB-AuNPs-AmB combination significantly reduced PCs. Understanding how these AuNPs aid in the fight against biofilms and the development of new approaches to eradicate PCs has relevance for chronic infection treatment.


Assuntos
Anfotericina B , Antifúngicos , Biofilmes , Candida tropicalis , Sinergismo Farmacológico , Ouro , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Candida tropicalis/efeitos dos fármacos , Ouro/química , Ouro/farmacologia , Biofilmes/efeitos dos fármacos , Anfotericina B/farmacologia , Anfotericina B/química , Nanopartículas Metálicas/química , Antifúngicos/farmacologia , Antifúngicos/química , Cetrimônio/química , Compostos de Cetrimônio/farmacologia , Compostos de Cetrimônio/química
2.
Nature ; 625(7996): 760-767, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38092039

RESUMO

GDF15, a hormone acting on the brainstem, has been implicated in the nausea and vomiting of pregnancy, including its most severe form, hyperemesis gravidarum (HG), but a full mechanistic understanding is lacking1-4. Here we report that fetal production of GDF15 and maternal sensitivity to it both contribute substantially to the risk of HG. We confirmed that higher GDF15 levels in maternal blood are associated with vomiting in pregnancy and HG. Using mass spectrometry to detect a naturally labelled GDF15 variant, we demonstrate that the vast majority of GDF15 in the maternal plasma is derived from the feto-placental unit. By studying carriers of rare and common genetic variants, we found that low levels of GDF15 in the non-pregnant state increase the risk of developing HG. Conversely, women with ß-thalassaemia, a condition in which GDF15 levels are chronically high5, report very low levels of nausea and vomiting of pregnancy. In mice, the acute food intake response to a bolus of GDF15 is influenced bi-directionally by prior levels of circulating GDF15 in a manner suggesting that this system is susceptible to desensitization. Our findings support a putative causal role for fetally derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by prepregnancy exposure to the hormone, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.


Assuntos
Fator 15 de Diferenciação de Crescimento , Hiperêmese Gravídica , Náusea , Vômito , Animais , Feminino , Humanos , Camundongos , Gravidez , Talassemia beta/sangue , Talassemia beta/metabolismo , Feto/metabolismo , Fator 15 de Diferenciação de Crescimento/sangue , Fator 15 de Diferenciação de Crescimento/metabolismo , Hormônios/sangue , Hormônios/metabolismo , Hiperêmese Gravídica/complicações , Hiperêmese Gravídica/metabolismo , Hiperêmese Gravídica/prevenção & controle , Hiperêmese Gravídica/terapia , Náusea/sangue , Náusea/complicações , Náusea/metabolismo , Placenta/metabolismo , Vômito/sangue , Vômito/complicações , Vômito/metabolismo
3.
J Reconstr Microsurg ; 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38011855

RESUMO

BACKGROUND: Interposition microvascular grafting may be required to bridge arterial defects during digital replantation or revascularization and has traditionally been performed utilizing a venous autograft. Arterial interposition grafting has been shown to be superior in maintaining patency in large vessel surgery; there are case reports of its use in microsurgery. METHODS: Six fellowship-trained hand and microsurgeons performed arterial and venous interposition grafts on the femoral arteries of 40 Wistar rats. After sectioning one femoral artery a segment of the contralateral femoral artery or vein was obtained. The time was recorded per graft and patency tested 10 minutes following grafting by an independent assessor. Each surgeon also completed a questionnaire detailing regular microsurgical volume, technical ease, and conceptual preference for either graft. RESULTS: Time for arterial interposition (median time 51.7 minutes) was longer than venous grafting (median time 45.9 minutes, p = 0.075). Arterial grafts were more likely to be patent or questionably patent (odds ratio [OR] = 6.77, p = 0.031). All surgeons found arterial interposition grafting technically easier and preferred it conceptually. Improvements were noted in patency rates (OR = 11.29, p = 0.018) and avoidance of anastomotic leak (OR = 0.19, p = 0.029) when surgeons performed moderate levels or greater of microsurgery within their regular practice. CONCLUSION: Greater immediate patency was noted with arterial interposition grafting in a rodent model when compared to venous grafting, although procedural time was greater. All surgeons found arterial grafting technically easier. Arterial microvascular grafting may be useful in the setting of digital replantation or revascularization with an arterial defect.

4.
bioRxiv ; 2023 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-37398065

RESUMO

Human pregnancy is frequently accompanied by nausea and vomiting that may become severe and life-threatening, as in hyperemesis gravidarum (HG), the cause of which is unknown. Growth Differentiation Factor-15 (GDF15), a hormone known to act on the hindbrain to cause emesis, is highly expressed in the placenta and its levels in maternal blood rise rapidly in pregnancy. Variants in the maternal GDF15 gene are associated with HG. Here we report that fetal production of GDF15, and maternal sensitivity to it, both contribute substantially to the risk of HG. We found that the great majority of GDF15 in maternal circulation is derived from the feto-placental unit and that higher GDF15 levels in maternal blood are associated with vomiting and are further elevated in patients with HG. Conversely, we found that lower levels of GDF15 in the non-pregnant state predispose women to HG. A rare C211G variant in GDF15 which strongly predisposes mothers to HG, particularly when the fetus is wild-type, was found to markedly impair cellular secretion of GDF15 and associate with low circulating levels of GDF15 in the non-pregnant state. Consistent with this, two common GDF15 haplotypes which predispose to HG were associated with lower circulating levels outside pregnancy. The administration of a long-acting form of GDF15 to wild-type mice markedly reduced subsequent responses to an acute dose, establishing that desensitisation is a feature of this system. GDF15 levels are known to be highly and chronically elevated in patients with beta thalassemia. In women with this disorder, reports of symptoms of nausea or vomiting in pregnancy were strikingly diminished. Our findings support a causal role for fetal derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by pre-pregnancy exposure to GDF15, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.

6.
Aust Vet J ; 101(7): 282-290, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37095694

RESUMO

INTRODUCTION: Tiliqua scincoides coexists with human activity and is frequently presented for rehabilitation due to injury. The correct identification of sex is important as animals identified as female should be subject to a different decision-making matrix for rehabilitation. However, identification of sex is notoriously difficult in Tiliqua scincoides. We describe a reliable, safe and cost-effective morphometry-based method. MATERIALS AND METHODS: Adult and sub-adult, wild Tiliqua scincoides dead on presentation or euthanased due to their presenting injuries were collected in South-East Queensland (SE Qld). Head-width to snout-vent length ratio (H:SV) and head-width to trunk length ratio (H:T) were measured and sex was defined at necropsy. Similar data were obtained from a previous study in Sydney, New South Wales (NSW). H:SV and H:T were assessed for accuracy of sex prediction by the area under the receiver operating characteristic curve (AUC-ROC). Optimal cut-points were identified. RESULTS: The AUC-ROC for the H:T test was for NSW adults, 0.99 (n = 29), NSW sub-adults, 0.95 (n = 10), Qld adults, 0.90 (n = 35) and Qld sub-adults, 0.79 (n = 25). In all cases, H:T was as good or superior to H:SV. H:T cut-points optimized for female sexing or both sexes ranged from 0.20 to 0.23 depending on State and adult status. Sensitivities and specificities of the test at suggested optimal cut-points ranged from 0.54 to 1.0. CONCLUSION: We describe how H:T can be used as an accurate method to determine sex in Tiliqua scincoides. However, it is more accurate in adults than sub-adults and more accurate in NSW skinks than in SE Qld skinks.


Assuntos
Lagartos , Masculino , Feminino , Humanos , Animais , New South Wales , Queensland
7.
Sex Health ; 19(2): 127-131, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35437141

RESUMO

BACKGROUND: STI rates have been reported as reduced during the height of the COVID-19 pandemic. Our study evaluates the number of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections recorded relative to the number of tests performed in 2017-2021, thus accurately depicting trends over time and evaluate the effect of COVID-19 restrictions since these were implemented in March 2020. METHODS: Data was extracted from an electronic database of pathology and clinical records used at Gold Coast Sexual Health Service (GCSHS) in Queensland, Australia from January 2017 to October 2021. Poisson regression-based interrupted time series analyses were performed for number of tests performed and test positivity over the study period. The COVID-19 period was defined as starting from March 2020 when public health directives were implemented. RESULTS: CT and NG testing dropped significantly in the month after COVID-19 restrictions were brought in, by 30% and 23% respectively. Over the 5year study period, the proportion of positive CT tests has consistently decreased by approximately 0.33% points per year (P ≤0.001). The instigation of COVID-19 restrictions had no effect on this trend. The proportion of NG positive tests remained steady prior to COVID-19 (P =0.96) at approximately 3.5%, decreased immediately at the onset of COVID-19 restrictions to approximately 2.5% (P <0.001) and has remained at this level post-COVID restrictions (P =0.54). Testing at GCSHS continued to target gay and bisexual men, accounting for ≥50% of all tests performed. CONCLUSION: Our study suggests that there has been a sustained reduction in test positivity of NG infections in the 18months since COVID-19 restrictions were implemented, and that this is not an artifact of reduced testing. It highlights the importance of maintaining health messaging including screening for sexually transmissible infections and maintaining access to services, which may include alternative models of care such as Telehealth, self-testing and collaboration between all sexual health service providers.


Assuntos
COVID-19 , Infecções por Chlamydia , Gonorreia , Humanos , Masculino , Austrália , Infecções por Chlamydia/diagnóstico , Chlamydia trachomatis , Gonorreia/epidemiologia , Análise de Séries Temporais Interrompida , Neisseria gonorrhoeae , Pandemias
8.
EBioMedicine ; 63: 103198, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33421943

RESUMO

BACKGROUND: Altered lipid metabolism in early life has been associated with subsequent weight gain and predicting this could aid in obesity prevention and risk management. Here, a lipidomic approach was used to identify circulating markers for future obesity risk in translational murine models and validate in a human infant cohort. METHODS: Lipidomics was performed on the plasma of APOE*3 Leiden, Ldlr-/-.Leiden, and the wild-type C57BL/6J mice to capture candidate biomarkers predicting subsequent obesity parameters after exposure to high-fat diet. The identified candidate biomarkers were mapped onto corresponding lipid metabolism pathways and were investigated in the Cambridge Baby Growth Study. Infants' growth and adiposity were measured at 0-24 months. Capillary dried blood spots were sampled at 3 months for lipid profiling analysis. FINDINGS: From the mouse models, cholesteryl esters were correlated with subsequent weight gain and other obesity parameters after HFD period (Spearman's r≥0.5, FDR p values <0.05) among APOE*3 Leiden and Ldlr-/-.Leiden mice, but not among the wild-type C57BL/6J. Pathway analysis showed that those identified cholesteryl esters were educts or products of desaturases activities: stearoyl-CoA desaturase-1 (SCD1) and fatty acid desaturase (FADS) 1 and 2. In the human cohort, lipid ratios affected by SCD1 at 3 months was inversely associated with 3-12 months weight gain (B±SE=-0.31±0.14, p=0.027), but positively with 12-24 months weight and adiposity gains (0.17±0.07, p=0.02 and 0.17±0.07, 0.53±0.26, p=0.04, respectively). Lipid ratios affected by SCD1 and FADS2 were inversely associated with adiposity gain but positively with height gain between 3-12 months. INTERPRETATION: From murine models to human setting, the ratios of circulating lipid species indicating key desaturase activities in lipid metabolism were associated with subsequent body size increase, providing a potential tool to predict early life weight gain.


Assuntos
Adiposidade , Biomarcadores , Ácidos Graxos Dessaturases/metabolismo , Metabolismo dos Lipídeos , Estearoil-CoA Dessaturase/metabolismo , Adiposidade/genética , Animais , Dessaturase de Ácido Graxo Delta-5 , Dieta Hiperlipídica , Ácidos Graxos Dessaturases/genética , Humanos , Lipidômica/métodos , Masculino , Camundongos , Obesidade/etiologia , Obesidade/metabolismo , Estearoil-CoA Dessaturase/genética
9.
Ann Hum Biol ; 47(2): 142-149, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32429763

RESUMO

Background: Highly consistent positive associations are reported between infancy growth and later obesity risk. However, it is unclear whether infancy growth parameters beyond body weight add to the prediction of later obesity risk.Aim: To assess whether infancy length and skinfold thicknesses add to infancy weight in the prediction of childhood adiposity.Subjects and methods: This analysis included 254 children with available data on infant growth from birth to 24 months and childhood adiposity at age 6-11 years measured by DXA. Multilevel linear regression was used to examine the predictors of childhood percent body fat (%BF), with adjustment for sex and age at follow-up visit.Results: Birth weight and weight gain (modelled as changes in z-score) between 0-3 months and 3-24 months showed independent positive relationships with childhood %BF. The addition of gains in infant length and skinfolds between 0-3 months, but not 3-24 months, improved overall model prediction, from 18.7% to 20.7% of the variance in childhood %BF (likelihood ratio test, p < 0.0001), although their independent effect estimates were small (infant length gain: negative trend, partial R-square 0.6%, p = 0.2; skinfolds: positive trend, 1.3%, p = 0.09).Conclusion: Infancy length and skinfolds contribute significantly, but only modestly, to the prediction of childhood adiposity.


Assuntos
Adiposidade , Desenvolvimento Infantil , Obesidade Infantil/etiologia , Aumento de Peso , Peso ao Nascer , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
10.
Hum Reprod ; 35(4): 913-928, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32325494

RESUMO

STUDY QUESTION: Are maternal serum phthalate metabolite, phenol and paraben concentrations measured at 10-17 weeks of gestation associated with male infant genital developmental outcomes, specifically cryptorchidism, anogenital distance (AGD), penile length and testicular descent distance, at birth and postnatally? SUMMARY ANSWER: Maternal serum bisphenol A (BPA) concentration at 10-17 weeks of gestation was positively associated with congenital or postnatally acquired cryptorchidism, and n-propyl paraben (n-PrP) concentration was associated with shorter AGD from birth to 24 months of age. WHAT IS KNOWN ALREADY: Male reproductive disorders are increasing in prevalence, which may reflect environmental influences on foetal testicular development. Animal studies have implicated phthalates, BPA and parabens, to which humans are ubiquitously exposed. However, epidemiological studies have generated conflicting results and have often been limited by small sample size and/or measurement of chemical exposures outside the most relevant developmental window. STUDY DESIGN, SIZE, DURATION: Case-control study of cryptorchidism nested within a prospective cohort study (Cambridge Baby Growth Study), with recruitment of pregnant women at 10-17 postmenstrual weeks of gestation from a single UK maternity unit between 2001 and 2009 and 24 months of infant follow-up. Of 2229 recruited women, 1640 continued with the infancy study after delivery, of whom 330 mothers of 334 male infants (30 with congenital cryptorchidism, 25 with postnatally acquired cryptorchidism and 279 unmatched controls) were included in the present analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: Maternal blood was collected at enrolment, and serum levels of 16 phthalate metabolites, 9 phenols (including BPA) and 6 parabens were measured using liquid chromatography/tandem mass spectrometry. Logistic regression was used to model the association of cryptorchidism with serum chemical concentrations, adjusting for putative confounders. Additionally, offspring AGD, penile length and testicular descent distance were assessed at 0, 3, 12, 18 and 24 months of age, and age-specific Z scores were calculated. Associations between serum chemical levels and these outcomes were tested using linear mixed models. MAIN RESULTS AND THE ROLE OF CHANCE: Maternal serum BPA concentration was associated with offspring all-type cryptorchidism both when considered as a continuous exposure (adjusted odds ratio per log10 µg/l: 2.90, 95% CI 1.31-6.43, P = 0.009) and as quartiles (phet = 0.002). Detection of n-PrP in maternal serum was associated with shorter AGD (by 0.242 standard deviations, 95% CI 0.051-0.433, P = 0.01) from birth to 24 months of age; this reduction was independent of body size and other putative confounders. We did not find any consistent associations with offspring outcomes for the other phenols, parabens, and phthalate metabolites measured. LIMITATIONS, REASONS FOR CAUTION: We cannot discount confounding by other demographic factors or endocrine-disrupting chemicals. There may have been misclassification of chemical exposure due to use of single serum measurements. The cohort was not fully representative of pregnant women in the UK, particularly in terms of smoking prevalence and maternal ethnicity. WIDER IMPLICATIONS OF THE FINDINGS: Our observational findings support experimental evidence that intrauterine exposure to BPA and n-PrP during early gestation may adversely affect male reproductive development. More evidence is required before specific public health recommendations can be made. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a European Union Framework V programme, the World Cancer Research Fund International, the Medical Research Council (UK), Newlife the Charity for Disabled Children, the Mothercare Group Foundation, Mead Johnson Nutrition and the National Institute for Health Research Cambridge Comprehensive Biomedical Research Centre. Visiting Fellowship (J.M.): Regional Programme 'Jiménez de la Espada' for Research Mobility, Cooperation and Internationalization, Seneca Foundation-Science and Technology Agency for the Region of Murcia (No. 20136/EE/17). K.O. is supported by the Medical Research Council (UK) (Unit Programme number: MC_UU_12015/2). The authors declare no conflict of interest.


Assuntos
Parabenos , Fenóis , Compostos Benzidrílicos , Estudos de Casos e Controles , Criança , Feminino , Humanos , Lactente , Masculino , Fenóis/toxicidade , Gravidez , Estudos Prospectivos
11.
Osteoporos Int ; 31(5): 1001-1005, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31901946

RESUMO

PURPOSE: Scurvy, due to vitamin C deficiency, is commonly referenced as a "forgotten" or "historical" disease. A growing number of case reports challenge this notion. Bone health providers are often consulted early in the presentation of scurvy to evaluate musculoskeletal complaints resulting from impaired collagen production and disrupted endochondral bone formation. In this report, we describe two cases of childhood scurvy. Our objective is to summarize the key features of scurvy for bone health providers, with the goal of raising awareness and facilitating diagnosis in future cases. CASE DESCRIPTIONS: Case one occurred in a 12-year-old non-verbal, non-ambulatory female on a ketogenic diet for refractory epilepsy. Clinical findings included hemarthrosis, transfusion dependent anemia, elevated inflammatory markers, and epiphysiolysis. Magnetic resonance imaging (MRI) revealed multi-focal bone marrow signal abnormalities and physeal irregularities. Case two occurred in a typically developing 5-year-old male presenting with limp and knee pain. Symptoms progressed despite casting and immobilization. Mild anemia, elevated inflammatory markers, and multi-focal marrow and physeal MRI abnormalities were identified. Subsequent dietary history revealed total absence of fruit or vegetable consumption. The diagnosis of scurvy was confirmed in both cases by undetectable plasma vitamin C concentrations. Treatment with vitamin C led to rapid clinical improvement. CONCLUSION: Scurvy can no longer be considered a historical diagnosis and should not be forgotten when evaluating children with musculoskeletal ailments. Early recognition of the signs, symptoms, and imaging findings of scurvy can reduce the clinical burden of this disease with the timely initiation of vitamin C therapy.


Assuntos
Escorbuto , Ácido Ascórbico/uso terapêutico , Densidade Óssea , Criança , Pré-Escolar , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Escorbuto/complicações , Escorbuto/diagnóstico , Escorbuto/tratamento farmacológico , Vitaminas
12.
Phys Rev Lett ; 122(11): 113401, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30951353

RESUMO

By measuring the transmission of near-resonant light through an atomic vapor confined in a nanocell we demonstrate a mesoscopic optical response arising from the nonlocality induced by the motion of atoms with a phase coherence length larger than the cell thickness. Whereas conventional dispersion theory-where the local atomic response is simply convolved by the Maxwell-Boltzmann velocity distribution-is unable to reproduce the measured spectra, a model including a nonlocal, size-dependent susceptibility is found to be in excellent agreement with the measurements. This result improves our understanding of light-matter interaction in the mesoscopic regime and has implications for applications where mesoscopic effects may degrade or enhance the performance of miniaturized atomic sensors.

13.
Bone ; 116: 181-186, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30055340

RESUMO

Oral glucocorticoids (GC) preserve muscle strength and prolong walking in boys with Duchenne muscular dystrophy (DMD). Although vertebral fractures have been reported in boys taking GC, fracture rates for different GC regimes have not been investigated. The aim of this pragmatic longitudinal study was to compare growth, body mass, bone mineral density (BMD), vertebral fractures (VF) and ambulatory status in boys with DMD on daily (DAILY) or intermittent (INTERMITTENT), oral GC regimens. A convenience sample of 50 DMD boys from two centres was included in the study; 25 boys each were on the DAILY or INTERMITTENT regimen. Size adjusted lumbar spine BMD (LS BMAD), total body less head BMD (TBLH), by DXA and distal forearm bone densities by pQCT, GC exposure, VF assessment and ambulatory status were analysed at three time points; baseline, 1 and 2 years. At baseline, there were no differences in age, GC duration or any bone parameters. However, DAILY boys were shorter (height SDS DAILY = -1.4(0.9); INTERMITTENT = -0.8(1.0), p = 0.04) with higher BMI (BMI SDS DAILY = 1.5(0.9); INTERMITTENT = 0.8(1.0), p = 0.01). Over 2 years, DAILY boys got progressively shorter (delta height SDS DAILY = -0.9(1.1); INTERMITTENT = +0.1(0.6), p < 0.001). At their 2 year assessment, 5 DAILY and 10 INTERMITTENT boys were non-ambulant. DAILY boys had more VFs than INTERMITTENT boys (10 versus 2; χ2 p = 0.008). BMAD SDS remained unchanged between groups. TBLH and radius BMD declined significantly but the rate of loss was not different. In conclusion, there was a trend for more boys on daily GCs to remain ambulant but at the cost of more VFs, greater adiposity and markedly diminished growth. In contrast, boys on intermittent GCs had fewer vertebral fractures but there was a trend for more boys to loose independent ambulation.


Assuntos
Osso e Ossos/patologia , Glucocorticoides/uso terapêutico , Crescimento e Desenvolvimento , Distrofia Muscular de Duchenne/tratamento farmacológico , Caminhada , Administração Oral , Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiopatologia , Criança , Esquema de Medicação , Seguimentos , Fraturas Ósseas/complicações , Fraturas Ósseas/patologia , Fraturas Ósseas/fisiopatologia , Glucocorticoides/farmacologia , Crescimento e Desenvolvimento/efeitos dos fármacos , Humanos , Masculino , Distrofia Muscular de Duchenne/complicações , Distrofia Muscular de Duchenne/fisiopatologia
14.
Phys Rev Lett ; 120(24): 243401, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29956978

RESUMO

We measure the near-resonant transmission of light through a dense medium of potassium vapor confined in a cell with nanometer thickness in order to investigate the origin and validity of the collective Lamb shift. A complete model including the multiple reflections in the nanocell reproduces accurately the observed line shape. It allows the extraction of a density-dependent shift and width of the bulk atomic medium resonance, deconvolved from the cavity effect. We observe an additional, unexpected dependence of the shift with the thickness of the medium. This extra dependence demands further experimental and theoretical investigations.

15.
Phys Rev Lett ; 120(16): 163903, 2018 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-29756941

RESUMO

In this Letter, we show that it is possible to structure the longitudinal polarization component of light. We illustrate our approach by demonstrating linked and knotted longitudinal vortex lines acquired upon nonparaxially propagating a tightly focused subwavelength beam. The remaining degrees of freedom in the transverse polarization components can be exploited to generate customized topological vector beams.

16.
Phys Rev Lett ; 118(25): 253601, 2017 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-28696754

RESUMO

We experimentally demonstrate the heralded generation of bichromatic single photons from an atomic collective spin excitation (CSE). The photon arrival times display collective quantum beats, a novel interference effect resulting from the relative motion of atoms in the CSE. A combination of velocity-selective excitation with strong laser dressing and the addition of a magnetic field allows for exquisite control of this collective beat phenomenon. The present experiment uses a diamond scheme with near-IR photons that can be extended to include telecommunications wavelengths or modified to allow storage and retrieval in an inverted-Y scheme.

17.
Diabetes Metab ; 43(4): 323-331, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28392167

RESUMO

AIM: We hypothesised that some of the genetic risk for gestational diabetes (GDM) is due to the fetal genome affecting maternal glucose concentrations. Previously, we found associations between fetal IGF2 gene variants and maternal glucose concentrations in late pregnancy. METHODS: In the present study, we tested associations between SNP alleles from 15 fetal imprinted genes and maternal glucose concentrations in late pregnancy in the Cambridge Baby Growth and Wellbeing cohorts (1160 DNA trios). RESULTS: Four fetal SNP alleles with the strongest univariate associations: paternally-transmitted IGF2 rs10770125 (P-value=2×10-4) and INS rs2585 (P-value=7×10-4), and maternally-transmitted KCNQ1(OT1) rs231841 (P-value=1×10-3) and KCNQ1(OT1) rs7929804 (P-value=4×10-3), were used to construct a composite fetal imprinted gene allele score which was associated with maternal glucose concentrations (P-value=4.3×10-6, n=981, r2=2.0%) and GDM prevalence (odds ratio per allele 1.44 (1.15, 1.80), P-value=1×10-3, n=89 cases and 899 controls). Meta-analysis of the associations including data from 1367 Hyperglycaemia and Adverse Pregnancy Outcome Study participants confirmed the paternally-transmitted fetal IGF2/INS SNP associations (rs10770125, P-value=3.2×10-8, rs2585, P-value=3.6×10-5) and the composite fetal imprinted gene allele score association (P-value=1.3×10-8), but not the maternally-transmitted fetal KCNQ1(OT1) associations (rs231841, P-value=0.4; rs7929804, P-value=0.2). CONCLUSION: This study suggests that polymorphic variation in fetal imprinted genes, particularly in the IGF2/INS region, contribute a small but significant part to the risk of raised late pregnancy maternal glucose concentrations.


Assuntos
Alelos , Glicemia/genética , Diabetes Gestacional/genética , Impressão Genômica , Polimorfismo de Nucleotídeo Único , Adulto , Diabetes Gestacional/sangue , Feminino , Humanos , Insulina/genética , Fator de Crescimento Insulin-Like II/genética , Canal de Potássio KCNQ1/genética , Gravidez , Resultado da Gravidez
18.
J Pediatr Urol ; 13(5): 498.e1-498.e6, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28351649

RESUMO

BACKGROUND: Complete androgen insensitivity syndrome (CAIS) is an X-linked recessive disorder of sex development (DSD) where affected individuals are phenotypically female, but have an XY karyotype and testes. The risk of gonadal tumour development in CAIS may increase with age; incidence rates have been reported to be 0.8-22% in patients who have retained their gonads into adulthood. Consequently, gonadectomy has been recommended either during childhood or after puberty is complete, although there is no consensus on the optimal timing for this procedure. OBJECTIVE AND HYPOTHESES: To establish the frequency of histological abnormalities in CAIS in relation to the age at gonadectomy. METHOD: Data were collected from the Cambridge DSD database on patients with CAIS (n = 225; age range 3-88 years) who had undergone gonadectomy, and their age of gonadectomy, gonadal histology and immunohistochemistry. RESULTS: Evaluable data were obtained from 133 patients. Median age at gonadectomy was 14.0 years (range: 18 days-68 years). Pubertal status was: prepuberty, n = 62; postpuberty, n = 68. Thirteen cases were aged >20 years at gonadectomy. The pattern of histology is summarised in the Summary table. DISCUSSION: In this large case series of CAIS patients who had undergone gonadectomy, while the combined malignant and premalignant gonadal histology prevalence was 6.0%, the findings confirm the low occurrence of gonadal malignancy in CAIS, with a frequency of 1.5%. The two cases of malignancy were postpubertal. Germ cell neoplasia in situ (GCNIS) was observed in six cases, of which one occurred prepuberty and five postpuberty. The study highlighted difficulties in diagnosis of GCNIS and the need for histological analysis in expert centres. CONCLUSION: The results support the current recommendation that gonads in CAIS can be retained until early adulthood. The small number of individuals with gonadectomy after age 20 years do not allow firm conclusion regarding later adulthood. Therefore, it is recommended that the option of gonadectomy be discussed in adulthood. Some form of regular surveillance of the gonads is then recommended, although none of the available options are ideal.


Assuntos
Síndrome de Resistência a Andrógenos/epidemiologia , Síndrome de Resistência a Andrógenos/cirurgia , Gônadas/cirurgia , Neoplasias Embrionárias de Células Germinativas/epidemiologia , Neoplasias Embrionárias de Células Germinativas/cirurgia , Adolescente , Adulto , Fatores Etários , Síndrome de Resistência a Andrógenos/diagnóstico , Biópsia por Agulha , Criança , Pré-Escolar , Estudos de Coortes , Comorbidade , Bases de Dados Factuais , Feminino , Seguimentos , Gônadas/patologia , Humanos , Imuno-Histoquímica , Masculino , Neoplasias Embrionárias de Células Germinativas/patologia , Ovário/patologia , Ovário/cirurgia , Estudos Retrospectivos , Medição de Risco , Desenvolvimento Sexual/fisiologia , Testículo/patologia , Testículo/cirurgia , Resultado do Tratamento , Adulto Jovem
19.
Obes Sci Pract ; 2(1): 48-57, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-27812379

RESUMO

OBJECTIVE: We examined parental and early-life variables in order to identify risk factors for adulthood overweight and obesity in offspring. We report here on the longitudinal prevalence of overweight and obesity in Australian children born between 1989 and 1991 and followed from birth to age 22. METHODS: Data were analysed on 1355 participants from the Western Australian Pregnancy Cohort (Raine) Study, with anthropometry collected during pregnancy, at birth, one year and at three yearly intervals thereafter. Multivariate analyses and cross-sectional logistic regression quantified the timing and contribution of early-life risk factors for overweight and obesity in young-adulthood. RESULTS: At five years of age 12.6% of children were overweight and 5.2% were obese. By early adulthood, the prevalence of obesity had increased to 12.8%, whilst overweight remained relatively stable at 14.2% (range from early childhood to adulthood 11-16%). Parental pre-pregnancy body mass index (BMI) was the strongest determinant of adult offspring BMI. Although rapid first year weight gain was associated with increased offspring BMI, the impact of first year weight-gain diminished over childhood, whilst the impact of parental BMI increased over time. CONCLUSIONS: Parental pre-pregnancy BMI and rapid early-life weight gain predispose offspring to obesity in adulthood.

20.
Hum Reprod ; 31(11): 2642-2650, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27609981

RESUMO

STUDY QUESTION: What is the relationship between maternal paracetamol intake during the masculinisation programming window (MPW, 8-14 weeks of gestation) and male infant anogenital distance (AGD), a biomarker for androgen action during the MPW? SUMMARY ANSWER: Intrauterine paracetamol exposure during 8-14 weeks of gestation is associated with shorter AGD from birth to 24 months of age. WHAT IS ALREADY KNOWN: The increasing prevalence of male reproductive disorders may reflect environmental influences on foetal testicular development during the MPW. Animal and human xenograft studies have demonstrated that paracetamol reduces foetal testicular testosterone production, consistent with reported epidemiological associations between prenatal paracetamol exposure and cryptorchidism. STUDY DESIGN, SIZE, DURATION: Prospective cohort study (Cambridge Baby Growth Study), with recruitment of pregnant women at ~12 post-menstrual weeks of gestation from a single UK maternity unit between 2001 and 2009, and 24 months of infant follow-up. Of 2229 recruited women, 1640 continued with the infancy study after delivery, of whom 676 delivered male infants and completed a medicine consumption questionnaire. PARTICIPANTS/MATERIALS, SETTING, METHOD: Mothers self-reported medicine consumption during pregnancy by a questionnaire administered during the perinatal period. Infant AGD (measured from 2006 onwards), penile length and testicular descent were assessed at 0, 3, 12, 18 and 24 months of age, and age-specific Z scores were calculated. Associations between paracetamol intake during three gestational periods (<8 weeks, 8-14 weeks and >14 weeks) and these outcomes were tested by linear mixed models. Two hundred and twenty-five (33%) of six hundred and eighty-one male infants were exposed to paracetamol during pregnancy, of whom sixty-eight were reported to be exposed during 8-14 weeks. AGD measurements were available for 434 male infants. MAIN RESULTS AND THE ROLE OF CHANCE: Paracetamol exposure during 8-14 weeks of gestation, but not any other period, was associated with shorter AGD (by 0.27 SD, 95% CI 0.06-0.48, P = 0.014) from birth to 24 months of age. This reduction was independent of body size. Paracetamol exposure was not related to penile length or testicular descent. LIMITATIONS, REASONS FOR CAUTION: Confounding by other drugs or endocrine-disrupting chemicals cannot be discounted. The cohort was not fully representative of pregnant women in the UK, particularly in terms of maternal ethnicity and smoking prevalence. There is likely to have been misclassification of paracetamol exposure due to recall error. WIDER IMPLICATIONS OF THE FINDINGS: Our observational findings support experimental evidence that intrauterine paracetamol exposure during the MPW may adversely affect male reproductive development. STUDY FUNDING/COMPETING INTERESTS: This work was supported by a European Union Framework V programme, the World Cancer Research Fund International, the Medical Research Council (UK), the Newlife Foundation for Disabled Children, the Evelyn Trust, the Mothercare Group Foundation, Mead Johnson Nutrition, and the National Institute for Health Research Cambridge Comprehensive Biomedical Research Centre. The authors declare no conflict of interest.


Assuntos
Acetaminofen/administração & dosagem , Canal Anal/anatomia & histologia , Efeitos Tardios da Exposição Pré-Natal , Testículo/anatomia & histologia , Canal Anal/efeitos dos fármacos , Biomarcadores , Pesos e Medidas Corporais , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Testículo/efeitos dos fármacos
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