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1.
J Geophys Res Solid Earth ; 126(8): e2021JB021976, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34595085

RESUMO

Processes for formation, cooling, and altering Earth's ocean crust are not yet completely understood due to challenges in access and sampling. Here, we use contiguous micro-imaging infrared spectroscopy to develop complete-core maps of mineral occurrence and investigate spatial patterns in the hydrothermal alteration of 1.2 km of oceanic crust recovered from Oman Drilling Project Holes GT1A, GT2A, and GT3A drilled in the Samail Ophiolite, Oman. The imaging spectrometer shortwave infrared sensor measured reflectance of light at wavelengths 1.0-2.6 µm at 250-260 µm/pixel, resulting in >1 billion independent measurements. We map distributions of nine key primary and secondary minerals/mineral groups-clinopyroxene, amphibole, calcite, chlorite, epidote, gypsum, kaolinite/montmorillonite, prehnite, and zeolite-and find differences in their spatial occurrences and pervasiveness. Accuracy of spectral mapping of occurrence is 68%-100%, established using X-ray diffraction measurements from the core description. The sheeted dikes and gabbros of upper oceanic crust Hole GT3A show more pervasive alteration and alteration dominated by chlorite, amphibole, and epidote. The foliated/layered gabbros of GT2A from intermediate crustal depths have similarly widespread chlorite but more zeolite and little amphibole and epidote. The layered gabbros of the lower oceanic crust (GT1A) have remnant pyroxene and 2X less chlorite, but alteration is extensive within and surrounding major fault zones with widespread occurrences of amphibole. The results indicate greater distribution of higher temperature alteration minerals in the upper oceanic crust relative to deeper gabbros and highlight the importance of fault zones in hydrothermal convection in the lower ocean crust.

2.
Nature ; 589(7840): E1, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33303960
3.
Bull World Health Organ ; 98(5): 330-340B, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32514198

RESUMO

OBJECTIVE: To evaluate changes in Ebola-related knowledge, attitudes and prevention practices during the Sierra Leone outbreak between 2014 and 2015. METHODS: Four cluster surveys were conducted: two before the outbreak peak (3499 participants) and two after (7104 participants). We assessed the effect of temporal and geographical factors on 16 knowledge, attitude and practice outcomes. FINDINGS: Fourteen of 16 knowledge, attitude and prevention practice outcomes improved across all regions from before to after the outbreak peak. The proportion of respondents willing to: (i) welcome Ebola survivors back into the community increased from 60.0% to 89.4% (adjusted odds ratio, aOR: 6.0; 95% confidence interval, CI: 3.9-9.1); and (ii) wait for a burial team following a relative's death increased from 86.0% to 95.9% (aOR: 4.4; 95% CI: 3.2-6.0). The proportion avoiding unsafe traditional burials increased from 27.3% to 48.2% (aOR: 3.1; 95% CI: 2.4-4.2) and the proportion believing spiritual healers can treat Ebola decreased from 15.9% to 5.0% (aOR: 0.2; 95% CI: 0.1-0.3). The likelihood respondents would wait for burial teams increased more in high-transmission (aOR: 6.2; 95% CI: 4.2-9.1) than low-transmission (aOR: 2.3; 95% CI: 1.4-3.8) regions. Self-reported avoidance of physical contact with corpses increased in high but not low-transmission regions, aOR: 1.9 (95% CI: 1.4-2.5) and aOR: 0.8 (95% CI: 0.6-1.2), respectively. CONCLUSION: Ebola knowledge, attitudes and prevention practices improved during the Sierra Leone outbreak, especially in high-transmission regions. Behaviourally-targeted community engagement should be prioritized early during outbreaks.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Doença pelo Vírus Ebola/psicologia , Adolescente , Adulto , Surtos de Doenças , Comportamentos Relacionados com a Saúde , Doença pelo Vírus Ebola/epidemiologia , Humanos , Serra Leoa/epidemiologia , Inquéritos e Questionários , Adulto Jovem
4.
J Infect Dis ; 222(8): 1311-1319, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32484879

RESUMO

BACKGROUND: During 2017, a multistate outbreak investigation occurred after the confirmation of Seoul virus (SEOV) infections in people and pet rats. A total of 147 humans and 897 rats were tested. METHODS: In addition to immunoglobulin (Ig)G and IgM serology and traditional reverse-transcription polymerase chain reaction (RT-PCR), novel quantitative RT-PCR primers/probe were developed, and whole genome sequencing was performed. RESULTS: Seventeen people had SEOV IgM, indicating recent infection; 7 reported symptoms and 3 were hospitalized. All patients recovered. Thirty-one facilities in 11 US states had SEOV infection, and among those with ≥10 rats tested, rat IgG prevalence ranged 2%-70% and SEOV RT-PCR positivity ranged 0%-70%. Human laboratory-confirmed cases were significantly associated with rat IgG positivity and RT-PCR positivity (P = .03 and P = .006, respectively). Genomic sequencing identified >99.5% homology between SEOV sequences in this outbreak, and these were >99% identical to SEOV associated with previous pet rat infections in England, the Netherlands, and France. Frequent trade of rats between home-based ratteries contributed to transmission of SEOV between facilities. CONCLUSIONS: Pet rat owners, breeders, and the healthcare and public health community should be aware and take steps to prevent SEOV transmission in pet rats and to humans. Biosecurity measures and diagnostic testing can prevent further infections.


Assuntos
Surtos de Doenças , Febre Hemorrágica com Síndrome Renal/transmissão , Doenças dos Roedores/transmissão , Vírus Seoul/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Cruzamento , Criança , Pré-Escolar , Técnicas de Laboratório Clínico/veterinária , Surtos de Doenças/veterinária , Genoma Viral/genética , Febre Hemorrágica com Síndrome Renal/diagnóstico , Febre Hemorrágica com Síndrome Renal/epidemiologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Lactente , Pessoa de Meia-Idade , Animais de Estimação/virologia , Filogenia , Prevalência , RNA Viral/genética , Ratos , Doenças dos Roedores/diagnóstico , Doenças dos Roedores/epidemiologia , Vírus Seoul/classificação , Vírus Seoul/genética , Vírus Seoul/imunologia , Estados Unidos/epidemiologia , Zoonoses Virais/diagnóstico , Zoonoses Virais/epidemiologia , Zoonoses Virais/transmissão , Adulto Jovem
5.
Nature ; 574(7778): 343-352, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31619791

RESUMO

A hidden carbon cycle exists inside Earth. Every year, megatons of carbon disappear into subduction zones, affecting atmospheric carbon dioxide and oxygen over Earth's history. Here we discuss the processes that move carbon towards subduction zones and transform it into fluids, magmas, volcanic gases and diamonds. The carbon dioxide emitted from arc volcanoes is largely recycled from subducted microfossils, organic remains and carbonate precipitates. The type of carbon input and the efficiency with which carbon is remobilized in the subduction zone vary greatly around the globe, with every convergent margin providing a natural laboratory for tracing subducting carbon.


Assuntos
Ciclo do Carbono , Planeta Terra , Carbono/química , Fenômenos Geológicos , Erupções Vulcânicas
6.
Nature ; 569(7757): 542-545, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31118522

RESUMO

Amorphous water ice comes in at least three distinct structural forms, all lacking long-range crystalline order. High-density amorphous ice (HDA) was first produced by compressing ice I to 11 kilobar at temperatures below 130 kelvin, and the process was described as thermodynamic melting1, implying that HDA is a glassy state of water. This concept, and the ability to transform HDA reversibly into low-density amorphous ice, inspired the two-liquid water model, which relates the amorphous phases to two liquid waters in the deeply supercooled regime (below 228 kelvin) to explain many of the anomalies of water2 (such as density and heat capacity anomalies). However, HDA formation has also been ascribed3 to a mechanical instability causing structural collapse and associated with kinetics too sluggish for recrystallization to occur. This interpretation is supported by simulations3, analogy with a structurally similar system4, and the observation of lattice-vibration softening as ice is compressed5,6. It also agrees with recent observations of ice compression at higher temperatures-in the 'no man's land' regime, between 145 and 200 kelvin, where kinetics are faster-resulting in crystalline phases7,8. Here we further probe the role of kinetics and show that, if carried out slowly, compression of ice I even at 100 kelvin (a region in which HDA typically forms) gives proton-ordered, but non-interpenetrating, ice IX', then proton-ordered and interpenetrating ice XV', and finally ice VIII'. By contrast, fast compression yields HDA but no ice IX, and direct transformation of ice I to ice XV' is structurally inhibited. These observations suggest that HDA formation is a consequence of a kinetically arrested transformation between low-density ice I and high-density ice XV' and challenge theories that connect amorphous ice to supercooled liquid water.

7.
Nat Commun ; 10(1): 789, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30770828

RESUMO

Current estimates of the carbon flux between the surface and mantle are highly variable, and the total amount of carbon stored in closed hidden reservoirs is unknown. Understanding the forms in which carbon existed in the molten early Earth is a critical step towards quantifying the carbon budget of Earth's deep interior. Here we employ first-principles molecular dynamics to study the evolution of carbon species as a function of pressure in a pyrolite melt. We find that with increasing pressure, the abundance of CO2 and CO3 species decreases at the expense of CO4 and complex oxo-carbon polymers (CxOy) displaying multiple C-C bonds. We anticipate that polymerized oxo-carbon species were a significant reservoir for carbon in the terrestrial magma ocean. The presence of Fe-C clusters suggests that upon segregation, Fe-rich metal may partition a significant fraction of carbon from the silicate liquid, leading to carbon transport into the Earth's core.

9.
PLoS Negl Trop Dis ; 12(3): e0006175, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29505579

RESUMO

BACKGROUND: Rift Valley Fever virus (RVF) is a zoonotic virus in the Phenuiviridae family. RVF outbreaks can cause significant morbidity and mortality in humans and animals. Following the diagnosis of two RVF cases in March 2016 in southern Kabale district, Uganda, we conducted a knowledge, attitudes and practice (KAP) survey to identify knowledge gaps and at-risk behaviors related to RVF. METHODOLOGY/PRINCIPAL FINDINGS: A multidisciplinary team interviewed 657 community members, including abattoir workers, in and around Kabale District, Uganda. Most participants (90%) had knowledge of RVF and most (77%) cited radio as their primary information source. Greater proportions of farmers (68%), herdsmen (79%) and butchers (88%) thought they were at risk of contracting RVF compared to persons in other occupations (60%, p<0.01). Participants most frequently identified bleeding as a symptom of RVF. Less than half of all participants reported fever, vomiting, and diarrhea as common RVF symptoms in either humans or animals. The level of knowledge about human RVF symptoms did not vary by occupation; however more farmers and butchers (36% and 51%, respectively) had knowledge of RVF symptoms in animals compared to those in other occupations (30%, p<0.01). The use of personal protective equipment (PPE) when handling animals varied by occupation, with 77% of butchers using some PPE and 12% of farmers using PPE. Although most butchers said that they used PPE, most used gumboots (73%) and aprons (60%) and less than 20% of butchers used gloves or eye protection when slaughtering. CONCLUSIONS: Overall, knowledge, attitudes and practice regarding RVF in Kabale District Uganda could be improved through educational efforts targeting specific populations.


Assuntos
Surtos de Doenças/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Equipamento de Proteção Individual/estatística & dados numéricos , Febre do Vale de Rift/fisiopatologia , Matadouros , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Uganda , Adulto Jovem
11.
Nature ; 539(7629): 420-424, 2016 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-27853207

RESUMO

The chemistry of aqueous fluids controls the transport and exchange-the cycles-of metals and volatile elements on Earth. Subduction zones, where oceanic plates sink into the Earth's interior, are the most important geodynamic setting for this fluid-mediated chemical exchange. Characterizing the ionic speciation and pH of fluids equilibrated with rocks at subduction zone conditions has long been a major challenge in Earth science. Here we report thermodynamic predictions of fluid-rock equilibria that tie together models of the thermal structure, mineralogy and fluid speciation of subduction zones. We find that the pH of fluids in subducted crustal lithologies is confined to a mildly alkaline range, modulated by rock volatile and chlorine contents. Cold subduction typical of the Phanerozoic eon favours the preservation of oxidized carbon in subducting slabs. In contrast, the pH of mantle wedge fluids is very sensitive to minor variations in rock composition. These variations may be caused by intramantle differentiation, or by infiltration of fluids enriched in alkali components extracted from the subducted crust. The sensitivity of pH to soluble elements in low abundance in the host rocks, such as carbon, alkali metals and halogens, illustrates a feedback between the chemistry of the Earth's atmosphere-ocean system and the speciation of subduction zone fluids via the composition of the seawater-altered oceanic lithosphere. Our findings provide a perspective on the controlling reactions that have coupled metal and volatile cycles in subduction zones for more than 3 billion years7.

12.
MMWR Suppl ; 65(3): 68-74, 2016 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-27386834

RESUMO

During the response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC addressed the disease on two fronts: in the epidemic epicenter of West Africa and at home in the United States. Different needs drove the demand for information in these two regions. The severity of the epidemic was reflected not only in lives lost but also in the amount of fear, misinformation, and stigma that it generated worldwide. CDC helped increase awareness, promoted actions to stop the spread of Ebola, and coordinated CDC communication efforts with multiple international and domestic partners. CDC, with input from partners, vastly increased the number of Ebola communication materials for groups with different needs, levels of health literacy, and cultural preferences. CDC deployed health communicators to West Africa to support ministries of health in developing and disseminating clear, science-based messages and promoting science-based behavioral interventions. Partnerships in West Africa with local radio, television, and cell phone businesses made possible the dissemination of messages appropriate for maximum effect. CDC and its partners communicated evolving science and risk in a culturally appropriate way to motivate persons to adapt their behavior and prevent infection with and spread of Ebola virus. Acknowledging what is and is not known is key to effective risk communication, and CDC worked with partners to integrate health promotion and behavioral and cultural knowledge into the response to increase awareness of the actual risk for Ebola and to promote protective actions and specific steps to stop its spread. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).


Assuntos
Centers for Disease Control and Prevention, U.S./organização & administração , Comunicação , Epidemias/prevenção & controle , Promoção da Saúde/organização & administração , Doença pelo Vírus Ebola/prevenção & controle , Risco , África Ocidental/epidemiologia , Doença pelo Vírus Ebola/epidemiologia , Humanos , Estados Unidos/epidemiologia
13.
PLoS One ; 10(9): e0138840, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26398672

RESUMO

Since the first mammal was cloned, the idea of using this technique to help endangered species has aroused considerable interest. However, several issues limit this possibility, including the relatively low success rate at every stage of the cloning process, and the dearth of usable tissues from these rare animals. iPS cells have been produced from cells from a number of rare mammalian species and this is the method of choice for strategies to improve cloning efficiency and create new gametes by directed differentiation. Nevertheless information about other stem cell/progenitor capabilities of cells from endangered species could prove important for future conservation approaches and adds to the knowledge base about cellular material that can be extremely limited. Multipotent progenitor cells, termed skin-derived precursor (SKP) cells, can be isolated directly from mammalian skin dermis, and human cheek tissue has also been shown to be a good source of SKP-like cells. Recently we showed that structures identical to SKPs termed m-SKPs could be obtained from monolayer/ two dimensional (2D) skin fibroblast cultures. Here we aimed to isolate m-SKPs from cultured cells of three endangered species; giant panda (Ailuropoda melanoleuca); red panda (Ailurus fulgens); and Asiatic lion (Panthera leo persica). m-SKP-like spheres were formed from the giant panda buccal mucosa fibroblasts; whereas dermal fibroblast (DF) cells cultured from abdominal skin of the other two species were unable to generate spheres. Under specific differentiation culture conditions giant panda spheres expressed neural, Schwann, adipogenic and osteogenic cell markers. Furthermore, these buccal mucosa derived spheres were shown to maintain expression of SKP markers: nestin, versican, fibronectin, and P75 and switch on expression of the stem cell marker ABCG2. These results demonstrate that giant panda cheek skin can be a useful source of m-SKP multipotent progenitors. At present lack of sample numbers means that we can only postulate why we were unable to obtain m-SKPs from the lion and red panda cultures. However the giant panda observations point to the value of archiving cells from rare species, and the possibilities for later progenitor cell derivation.


Assuntos
Mucosa Bucal/citologia , Células-Tronco Multipotentes/fisiologia , Animais , Diferenciação Celular , Separação Celular , Células Cultivadas , Ursidae
14.
Proc Natl Acad Sci U S A ; 112(30): E3997-4006, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26048906

RESUMO

Carbon fluxes in subduction zones can be better constrained by including new estimates of carbon concentration in subducting mantle peridotites, consideration of carbonate solubility in aqueous fluid along subduction geotherms, and diapirism of carbon-bearing metasediments. Whereas previous studies concluded that about half the subducting carbon is returned to the convecting mantle, we find that relatively little carbon may be recycled. If so, input from subduction zones into the overlying plate is larger than output from arc volcanoes plus diffuse venting, and substantial quantities of carbon are stored in the mantle lithosphere and crust. Also, if the subduction zone carbon cycle is nearly closed on time scales of 5-10 Ma, then the carbon content of the mantle lithosphere + crust + ocean + atmosphere must be increasing. Such an increase is consistent with inferences from noble gas data. Carbon in diamonds, which may have been recycled into the convecting mantle, is a small fraction of the global carbon inventory.

15.
Nat Commun ; 5: 5091, 2014 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-25311627

RESUMO

Knowledge of the occurrence and mobility of carbonate-rich melts in the Earth's mantle is important for understanding the deep carbon cycle and related geochemical and geophysical processes. However, our understanding of the mobility of carbonate-rich melts remains poor. Here we report viscosities of carbonate melts up to 6.2 GPa using a newly developed technique of ultrafast synchrotron X-ray imaging. These carbonate melts display ultralow viscosities, much lower than previously thought, in the range of 0.006-0.010 Pa s, which are ~2 to 3 orders of magnitude lower than those of basaltic melts in the upper mantle. As a result, the mobility of carbonate melts (defined as the ratio of melt-solid density contrast to melt viscosity) is ~2 to 3 orders of magnitude higher than that of basaltic melts. Such high mobility has significant influence on several magmatic processes, such as fast melt migration and effective melt extraction beneath mid-ocean ridges.

16.
Emerg Infect Dis ; 20(3): 386-93, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24565589

RESUMO

In summer 2012, an outbreak of hantavirus infections occurred among overnight visitors to Yosemite National Park in California, USA. An investigation encompassing clinical, epidemiologic, laboratory, and environmental factors identified 10 cases among residents of 3 states. Eight case-patients experienced hantavirus pulmonary syndrome, of whom 5 required intensive care with ventilatory support and 3 died. Staying overnight in a signature tent cabin (9 case-patients) was significantly associated with becoming infected with hantavirus (p<0.001). Rodent nests and tunnels were observed in the foam insulation of the cabin walls. Rodent trapping in the implicated area resulted in high trap success rate (51%), and antibodies reactive to Sin Nombre virus were detected in 10 (14%) of 73 captured deer mice. All signature tent cabins were closed and subsequently dismantled. Continuous public awareness and rodent control and exclusion are key measures in minimizing the risk for hantavirus infection in areas inhabited by deer mice.


Assuntos
Infecções por Hantavirus/epidemiologia , Orthohantavírus/classificação , Viagem , Adolescente , Adulto , California/epidemiologia , Criança , Surtos de Doenças , Monitoramento Ambiental , Orthohantavírus/genética , Infecções por Hantavirus/diagnóstico , Infecções por Hantavirus/história , Infecções por Hantavirus/prevenção & controle , História do Século XXI , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Sorotipagem , Adulto Jovem
17.
Emerg Infect Dis ; 20(2): 240-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24447605

RESUMO

We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention.


Assuntos
Criação de Animais Domésticos , Surtos de Doenças , Coriomeningite Linfocítica/veterinária , Vírus da Coriomeningite Linfocítica/classificação , Meningite Asséptica/epidemiologia , Exposição Ocupacional , RNA Viral/classificação , Adulto , Animais , Anticorpos Antivirais/sangue , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Coriomeningite Linfocítica/epidemiologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/genética , Masculino , Meningite Asséptica/imunologia , Meningite Asséptica/virologia , Camundongos , Filogenia , RNA Viral/genética , Ratos , Sorotipagem , Estados Unidos/epidemiologia
18.
Emerg Infect Dis ; 20(2): 291-5, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24447898

RESUMO

During follow-up of a 2012 US outbreak of lymphocytic choriomeningitis virus (LCMV), we conducted a trace-forward investigation. LCMV-infected feeder mice originating from a US rodent breeding facility had been distributed to >500 locations in 21 states. All mice from the facility were euthanized, and no additional persons tested positive for LCMV infection.


Assuntos
Anticorpos Antivirais/sangue , Surtos de Doenças , Coriomeningite Linfocítica/veterinária , Vírus da Coriomeningite Linfocítica/patogenicidade , Criação de Animais Domésticos , Animais , Cruzamento , Feminino , Coriomeningite Linfocítica/epidemiologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/fisiologia , Masculino , Camundongos , Estados Unidos/epidemiologia
19.
PLoS One ; 8(3): e59811, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23555789

RESUMO

The laboratory mouse is a key animal model for studies of adipose biology, metabolism and disease, yet the developmental changes that occur in tissues and cells that become the adipose layer in mouse skin have received little attention. Moreover, the terminology around this adipose body is often confusing, as frequently no distinction is made between adipose tissue within the skin, and so called subcutaneous fat. Here adipocyte development in mouse dorsal skin was investigated from before birth to the end of the first hair follicle growth cycle. Using Oil Red O staining, immunohistochemistry, quantitative RT-PCR and TUNEL staining we confirmed previous observations of a close spatio-temporal link between hair follicle development and the process of adipogenesis. However, unlike previous studies, we observed that the skin adipose layer was created from cells within the lower dermis. By day 16 of embryonic development (e16) the lower dermis was demarcated from the upper dermal layer, and commitment to adipogenesis in the lower dermis was signalled by expression of FABP4, a marker of adipocyte differentiation. In mature mice the skin adipose layer is separated from underlying subcutaneous adipose tissue by the panniculus carnosus. We observed that the skin adipose tissue did not combine or intermix with subcutaneous adipose tissue at any developmental time point. By transplanting skin isolated from e14.5 mice (prior to the start of adipogenesis), under the kidney capsule of adult mice, we showed that skin adipose tissue develops independently and without influence from subcutaneous depots. This study has reinforced the developmental link between hair follicles and skin adipocyte biology. We argue that because skin adipocytes develop from cells within the dermis and independently from subcutaneous adipose tissue, that it is accurately termed dermal adipose tissue and that, in laboratory mice at least, it represents a separate adipose depot.


Assuntos
Derme/embriologia , Derme/metabolismo , Proteínas de Ligação a Ácido Graxo/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Folículo Piloso/embriologia , Gordura Subcutânea/embriologia , Adipogenia , Adiposidade , Animais , Compostos Azo , Proteínas de Fluorescência Verde/metabolismo , Folículo Piloso/metabolismo , Imuno-Histoquímica , Lasers , Lipídeos/química , Masculino , Camundongos , Microscopia de Fluorescência , Gordura Subcutânea/metabolismo , Fatores de Tempo
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