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1.
Science ; 380(6652): 1338-1343, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37384687

RESUMO

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

2.
Science ; 378(6619): 538-543, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36378962

RESUMO

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy's active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of [Formula: see text] neutrinos at tera-electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera-electron volt gamma rays from this source.

3.
Phys Rev Lett ; 129(15): 151801, 2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36269964

RESUMO

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{µ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9} eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

4.
Phys Rev Lett ; 129(1): 011804, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35841552

RESUMO

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{µτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{µτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

5.
Phys Rev Lett ; 128(5): 051101, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35179913

RESUMO

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19} cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with ß≳0.8 and up to ß∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

6.
Urologe A ; 61(2): 142-148, 2022 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-34939142

RESUMO

In recent years, technology in healthcare has experienced a dynamic increase, with the collection of data being a central component. In particular, artificial intelligence (AI), such as machine learning and deep learning, makes it possible to perform comprehensive analyses of large amounts of data and to draw conclusions based on correlations and pattern recognition. This paper describes the benefits and challenges of big data in patient care.


Assuntos
Inteligência Artificial , Aprendizado de Máquina , Big Data , Atenção à Saúde , Humanos , Assistência ao Paciente
7.
Phys Rev Lett ; 125(14): 141801, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064514

RESUMO

The results of a 3+1 sterile neutrino search using eight years of data from the IceCube Neutrino Observatory are presented. A total of 305 735 muon neutrino events are analyzed in reconstructed energy-zenith space to test for signatures of a matter-enhanced oscillation that would occur given a sterile neutrino state with a mass-squared differences between 0.01 and 100 eV^{2}. The best-fit point is found to be at sin^{2}(2θ_{24})=0.10 and Δm_{41}^{2}=4.5 eV^{2}, which is consistent with the no sterile neutrino hypothesis with a p value of 8.0%.

8.
Phys Rev Lett ; 125(12): 121104, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-33016752

RESUMO

We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of ϕ_{astro}=1.66_{-0.27}^{+0.25} at E_{0}=100 TeV, in agreement with IceCube's complementary muon neutrino results and with all-neutrino flavor fit results. In the measured energy range we reject spectral indices γ≤2.28 at ≥3σ significance level. Because of high neutrino energy resolution and low atmospheric neutrino backgrounds, this analysis provides the most detailed characterization of the neutrino flux at energies below ∼100 TeV compared to previous IceCube results. Results from fits assuming more complex neutrino flux models suggest a flux softening at high energies and a flux hardening at low energies (p value ≥0.06). The sizable and smooth flux measured below ∼100 TeV remains a puzzle. In order to not violate the isotropic diffuse gamma-ray background as measured by the Fermi Large Area Telescope, it suggests the existence of astrophysical neutrino sources characterized by dense environments which are opaque to gamma rays.

9.
Phys Rev Lett ; 124(5): 051103, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32083934

RESUMO

This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above ∼1 TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.

10.
Arch Gynecol Obstet ; 295(4): 1015-1024, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28185073

RESUMO

PURPOSE: To analyze cumulative pregnancy rates of subfertile couples after fertility awareness training. METHODS: A prospective observational cohort study followed 187 subfertile women, who had received training in self-observation of the fertile phase of the menstrual cycle with the Sensiplan method, for 8 months. The women, aged 21-47 years, had attempted to become pregnant for 3.5 years on average (range 1-8 years) before study entry. Amenorrhea, known tubal occlusion and severe male factor had been excluded. An additional seven women, who had initially been recruited, became pregnant during the cycle immediately prior to Sensiplan training: this is taken to be the spontaneous pregnancy rate per cycle in the cohort in the absence of fertility awareness training. RESULTS: The cumulative pregnancy rate of subfertile couples after fertility awareness training was 38% (95% CI 27-49%; 58 pregnancies) after eight observation months, which is significantly higher than the estimated basic pregnancy rate of 21.6% in untrained couples in the same cohort. For couples who had been seeking to become pregnant for 1-2 years, the pregnancy rate increased to 56% after 8 months. A female age above 35 (cumulative pregnancy rate 25%, p = 0.06), couples who had attempted to become pregnant for more than 2 years (cumulative pregnancy rate 17%, p < 0.01), all significantly reduce the chances of conceiving naturally at some point. CONCLUSIONS: Training women to identify their fertile window in the menstrual cycle seems to be a reasonable first-line therapy in the management of subfertility.


Assuntos
Características da Família , Conhecimentos, Atitudes e Prática em Saúde , Infertilidade/terapia , Taxa de Gravidez , Adulto , Feminino , Fertilidade , Fertilização , Humanos , Masculino , Ciclo Menstrual , Gravidez , Estudos Prospectivos , Comportamento Sexual
11.
Artigo em Alemão | MEDLINE | ID: mdl-22134661

RESUMO

Most traumata in small mammals occur at home. Diagnosis and therapy can be compared with that in the dog and cat, but species-specific differences have to be considered. For fracture treatment a butterfly-cast can be sufficient for stabilization in special cases. In most cases satisfying results can be obtained with a "tie-in-fixator" treatment. Dislocations of the elbow joint are treated by reduction or stabilization through suture techniques or temporary arthrodesis.


Assuntos
Fixação de Fratura/veterinária , Fraturas Ósseas/veterinária , Luxações Articulares/veterinária , Mamíferos/lesões , Analgésicos/classificação , Animais , Artrodese/veterinária , Moldes Cirúrgicos/veterinária , Gatos/lesões , Gatos/cirurgia , Cães/lesões , Cães/cirurgia , Furões/lesões , Furões/cirurgia , Fixação de Fratura/métodos , Fraturas Ósseas/cirurgia , Fraturas Ósseas/terapia , Luxações Articulares/cirurgia , Luxações Articulares/terapia , Mamíferos/cirurgia , Prognóstico , Coelhos/lesões , Coelhos/cirurgia , Roedores/lesões , Roedores/cirurgia , Especificidade da Espécie , Contenções/veterinária , Técnicas de Sutura/veterinária
12.
Phys Rev Lett ; 106(21): 210503, 2011 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-21699281

RESUMO

Entanglement between stationary systems at remote locations is a key resource for quantum networks. We report on the experimental generation of remote entanglement between a single atom inside an optical cavity and a Bose-Einstein condensate (BEC). To produce this, a single photon is created in the atom-cavity system, thereby generating atom-photon entanglement. The photon is transported to the BEC and converted into a collective excitation in the BEC, thus establishing matter-matter entanglement. After a variable delay, this entanglement is converted into photon-photon entanglement. The matter-matter entanglement lifetime of 100 µs exceeds the photon duration by 2 orders of magnitude. The total fidelity of all concatenated operations is 95%. This hybrid system opens up promising perspectives in the field of quantum information.

13.
J Int Med Res ; 35(3): 395-405, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17593869

RESUMO

This study investigated the effect of an anaesthetic regimen on the immune response in 40 long-term alcoholic patients undergoing surgery. Patients were randomly allocated to receive either propofol or isoflurane during surgery. Plasma cytokines interleukin (IL)-6 and IL-10 were measured at defined times and rates of post-operative infections were documented. The IL-6/IL-10 ratio significantly increased with propofol compared with isoflurane on day 1 after surgery and the IL-10 level significantly increased with isoflurane on day 1 after surgery. The overall post-operative infection rate was significantly higher in isoflurane-treated patients. Our findings indicate that propofol anaesthesia might be the more favourable regimen, with the IL-6/IL-10 ratio indicating an attenuation of the immune imbalance after surgery in long-term alcoholic patients. These results support the undertaking of a properly powered clinical trial to determine if propofol anaesthesia can reduce the postoperative infection rate in this special patient population.


Assuntos
Alcoolismo/imunologia , Interleucina-10/sangue , Interleucina-6/sangue , Isoflurano/uso terapêutico , Período Pós-Operatório , Propofol/uso terapêutico , Idoso , Anestésicos Intravenosos/uso terapêutico , Feminino , Trato Gastrointestinal/cirurgia , Humanos , Hidrocortisona/sangue , Infecções/etiologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Fator de Necrose Tumoral alfa/sangue
14.
Hum Reprod ; 22(5): 1310-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17314078

RESUMO

BACKGROUND: The efficacy of fertility awareness based (FAB) methods of family planning is critically reviewed. The objective was to investigate the efficacy and the acceptability of the symptothermal method (STM), an FAB method that uses two indicators of fertility, temperature and cervical secretions observation. This paper will recommend a more suitable approach to measure the efficacy. METHODS: Since 1985, an ongoing prospective observational longitudinal cohort study has been conducted in Germany. Women are asked to submit their menstrual cycle charts that record daily basal body temperature, cervical secretion observations and sexual behaviour. A cohort of 900 women contributed 17,638 cycles that met the inclusion criteria for the effectiveness study. The overall rates of unintended pregnancies and dropout rates have been estimated with survival curves according to the Kaplan-Meier method. In order to estimate the true method effectiveness, the pregnancy rates have been calculated in relation to sexual behaviour using the 'perfect/imperfect-use' model of Trussell and Grummer-Strawn. RESULTS: After 13 cycles, 1.8 per 100 women of the cohort experienced an unintended pregnancy; 9.2 per 100 women dropped out because of dissatisfaction with the method; the pregnancy rate was 0.6 per 100 women and per 13 cycles when there was no unprotected intercourse in the fertile time. CONCLUSIONS: The STM is a highly effective family planning method, provided the appropriate guidelines are consistently adhered to.


Assuntos
Fertilidade , Conhecimentos, Atitudes e Prática em Saúde , Métodos Naturais de Planejamento Familiar , Comportamento Sexual , Adulto , Temperatura Corporal , Muco do Colo Uterino/fisiologia , Serviços de Planejamento Familiar/educação , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Detecção da Ovulação/métodos , Satisfação do Paciente , Gravidez não Planejada , Estudos Prospectivos
15.
Eur Radiol ; 17(5): 1331-40, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17031452

RESUMO

For the connection of several partners to a Dicom-e-mail based teleradiology network concepts were developed to allow the integration of different teleradiology applications. The organisational and technical needs for such an integration were analysed. More than 60 institutions including 23 hospitals in the Rhein-Neckar-Region, Germany were connected. The needed functionality was grouped in six teleradiology applications (emergency consultation, tele-guided examinations, expert consultations, cooperative work, scientific cooperations and homework with on call services) and their technical and organisational needs according to availability, speed of transfer, workflow definitions and data security needs was analysed. For the local integration of teleradiology services the setup and workflow is presented for a standalone teleradiology workstation and a server based teleradiology gateway. The line type needed for different groups of applications and users is defined. The security concept and fallback strategies are laid out, potential security problems and sources of errors are discussed. The specialties for the emergency teleradiology application are presented. The DICOM-e-mail protocol is a flexible and powerful protocol that can be used for a variety of teleradiology applications. It can meet the conditions for emergency applications but is limited if synchronous applications like teleconferences are needed.


Assuntos
Correio Eletrônico/instrumentação , Internet , Sistemas de Informação em Radiologia/instrumentação , Telerradiologia/instrumentação , Segurança Computacional , Sistemas Computacionais , Alemanha , Humanos , Consulta Remota/instrumentação , Integração de Sistemas
16.
Gynecol Endocrinol ; 20(6): 305-12, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16019378

RESUMO

OBJECTIVES: The objective of the present paper is to review the main results of recent European cycle databases on ovulation detection and determination of the fertile window performed by the women themselves. METHODS: The ongoing German Long-term Cycle Database currently comprises 32788 prospectively collected cycle charts of 1551 women, the I European Cycle Database (10 countries) 1328 women/19048 cycles, the II European Cycle Database (six countries) 782 women/6724 cycles, and the World Health Organization Database (one European country) 234 women/2808 cycles. The women record cycle parameters (cervical mucus changes, temperature rise, etc.), family planning intention and sexual behavior. RESULTS: With the symptothermal method of natural family planning it has become possible to determine the fertile window in order to avoid pregnancy with a method effectiveness of 0.3%. According to a small sub-study, the ovulation time observed by the women themselves correlates closely with ovulation detected by ultrasound and measurement of luteinizing hormone (correlation within 1 day in 89% of the 62 cycles). Fertility awareness methods can be integrated into the management of sub-fertility. They seem to shorten the time to pregnancy. CONCLUSIONS: Self-observation of the fertile window puts women into a position to develop a high level of reproductive competence that could be used much more in different areas than is currently the case.


Assuntos
Bases de Dados Factuais , Conhecimentos, Atitudes e Prática em Saúde , Métodos Naturais de Planejamento Familiar/estatística & dados numéricos , Detecção da Ovulação/estatística & dados numéricos , Ovulação/fisiologia , Adulto , Europa (Continente)/epidemiologia , Feminino , Humanos
17.
Int J Sports Med ; 23(6): 422-7, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12215961

RESUMO

Leptin (L) is associated with body-weight-regulating and adipostatic functions. Its receptors also may be found centrally. Thyroid hormones regulate metabolic processes mainly by binding at peripheral receptors. Aim of this study was to show if there is a link between those central and peripheral regulation systems and to investigate the influence of different training intensities on L and the hypothalamic-thyroid-axis (HTA) in highly trained rowers. Six rowers (18.9 +/- 2.6 y; BMI 22.8 +/- 2.1 kg/m (2)) undertook high intensity resistance training (RT) for three weeks followed by three weeks of endurance training (ET). After each training cycle the subjects had one week for recovery (R1, R2). Blood samples were taken before and at the end of RT, R1, ET and R2. L, thyroid stimulating hormone (TSH), free T3 (fT3) and free T4 (fT4) were measured. After RT, a significant reduction in L, TSH and fT3 was found (p < 0.05). fT4 was unchanged. L remained decreased until the end of R1. After ET, a significant increase of TSH was found. L correlated to basal TSH levels (r = 0.49, p = 0.006) during R. BMI and body fat were unchanged throughout the study and were not correlated with hormonal levels. We speculate a high energy flux during intensified training (RT) caused the decrease of L and the HTA, independent of BMI or body fat. Thus, we conclude a depression of L and HTA is associated with training intensity.


Assuntos
Exercício Físico/fisiologia , Resistência Física/fisiologia , Esportes/fisiologia , Adolescente , Adulto , Humanos , Leptina/sangue , Masculino , Hormônios Tireóideos/sangue
18.
J Eur Acad Dermatol Venereol ; 16(2): 148-51, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12046819

RESUMO

Postoperative pyoderma gangrenosum (PPG), also known as postoperative progressive gangrene of Cullen, is a rare and rapidly evolving complication of surgical procedures. Since the first description by Cullen in 1924 (Surg Gynecol Obstet 1924; 38: 579-582) various case reports have been published. Even in typical cases PPG is often misdiagnosed and therefore wrongly treated; the unknown aetiology makes treatment difficult. The therapies used for pyoderma gangrenosum include systemic corticosteroids, azathioprine, dapsone, mercaptopurine, sulphasalazine, sulphapyridine, thalidomide, cyclophosphamide, clofazimine, isotretinoin, immunoglobulins and cyclosporin. We report on two patients with PPG following breast surgery who were successfully treated with low-dose cyclosporin (2.5-5 mg/kg per day).


Assuntos
Ciclosporina/administração & dosagem , Imunossupressores/administração & dosagem , Mamoplastia/efeitos adversos , Mastectomia/efeitos adversos , Complicações Pós-Operatórias/tratamento farmacológico , Pioderma Gangrenoso/diagnóstico , Pioderma Gangrenoso/tratamento farmacológico , Adulto , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/cirurgia , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Fibroadenoma/diagnóstico , Fibroadenoma/cirurgia , Seguimentos , Humanos , Mamoplastia/métodos , Mastectomia/métodos , Complicações Pós-Operatórias/diagnóstico , Pioderma Gangrenoso/etiologia , Resultado do Tratamento , Cicatrização/efeitos dos fármacos
19.
Am J Hum Genet ; 68(6): 1321-6, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11326338

RESUMO

Craniometaphyseal dysplasia (CMD) is a rare skeletal disorder characterized by progressive thickening and increased mineral density of craniofacial bones and abnormally developed metaphyses in long bones. Linkage studies mapped the locus for the autosomal dominant form of CMD to an approximately 5-cM interval on chromosome 5p, which is defined by recombinations between loci D5S810 and D5S1954. Mutational analysis of positional candidate genes was performed, and we describe herein three different mutations, in five different families and in isolated cases, in ANK, a multipass transmembrane protein involved in the transport of intracellular pyrophosphate into extracellular matrix. The mutations are two in-frame deletions and one in-frame insertion caused by a splicing defect. All mutations cluster within seven amino acids in one of the six possible cytosolic domains of ANK. These results suggest that the mutated protein has a dominant negative effect on the function of ANK, since reduced levels of pyrophosphate in bone matrix are known to increase mineralization.


Assuntos
Doenças do Desenvolvimento Ósseo/genética , Cromossomos Humanos Par 5/genética , Genes Dominantes/genética , Ligação Genética/genética , Proteínas de Membrana/genética , Mutação/genética , Sequência de Aminoácidos , Sequência de Bases , Células Cultivadas , Criança , Pré-Escolar , Citosol/química , Análise Mutacional de DNA , Éxons/genética , Feminino , Humanos , Escore Lod , Masculino , Proteínas de Membrana/química , Dados de Sequência Molecular , Osteoblastos/metabolismo , Linhagem , Proteínas de Transporte de Fosfato , Estrutura Terciária de Proteína , RNA Mensageiro/análise , RNA Mensageiro/genética
20.
Dev Biol ; 228(2): 337-49, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11112334

RESUMO

We have previously demonstrated that epithelial-mesenchymal transformation (EMT) brings about TGF beta 3-induced confluence of craniofacial primordia that derive from the maxillary processes and give rise to the avian palate. The upper lip of the chick embryo forms by confluence of primordia also derived from the maxillary processes, but in this case, they fuse with the intermaxillary segment of the nasofrontal process. Here, we ask whether the bilateral epithelial seams formed when these primordia contact each other in vivo are removed by apoptosis (as formerly was believed to occur in developing palate) or by EMT. We found that, as is the case in the palate, the periderm of the two-layered embryonic epithelium begins to slough shortly before these primordia fuse, bringing the basal epithelial cells into close contact. We show by TUNEL staining and confirm by TEM that apoptosis occurs only in periderm. TEM reveals that basal epithelial cells contacting each other to form the midline seam produce numerous desmosomes with each other. Then, basement membrane begins to disappear, numerous filopodia extend from the basal surfaces of epithelial cells, the space between them enlarges, and the seam breaks apart, leaving mesenchymal cells in its wake. Transformation of the carboxyfluorescein (CCFSE)-labeled epithelial seam is demonstrated in vivo by detection of CCFSE bodies in mesenchymal cells that replace it. This demonstration of EMT in avian lip development lays important groundwork for understanding the causes of human cleft lip and analyzing the mechanism of action of growth factors, such as SHH and BMPs, that have been shown (J. A. Helms et al., 1997, Dev. Biol. 187, 25-35) to be involved in avian lip confluence.


Assuntos
Embrião de Galinha/fisiologia , Células Epiteliais/fisiologia , Lábio/embriologia , Mesoderma/fisiologia , Morfogênese , Animais , Apoptose , Comunicação Celular , Embrião de Galinha/citologia , Desmossomos/fisiologia , Desmossomos/ultraestrutura , Células Epiteliais/citologia , Células Epiteliais/ultraestrutura , Face/embriologia , Humanos , Marcação In Situ das Extremidades Cortadas , Lábio/citologia , Mesoderma/citologia , Mesoderma/ultraestrutura , Palato/embriologia , Crânio/citologia , Crânio/embriologia
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