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1.
Nature ; 538(7626): 499-501, 2016 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-27680704

RESUMO

Uncertainties in the response of vegetation to rising atmospheric CO2 concentrations contribute to the large spread in projections of future climate change. Climate-carbon cycle models generally agree that elevated atmospheric CO2 concentrations will enhance terrestrial gross primary productivity (GPP). However, the magnitude of this CO2 fertilization effect varies from a 20 per cent to a 60 per cent increase in GPP for a doubling of atmospheric CO2 concentrations in model studies. Here we demonstrate emergent constraints on large-scale CO2 fertilization using observed changes in the amplitude of the atmospheric CO2 seasonal cycle that are thought to be the result of increasing terrestrial GPP. Our comparison of atmospheric CO2 measurements from Point Barrow in Alaska and Cape Kumukahi in Hawaii with historical simulations of the latest climate-carbon cycle models demonstrates that the increase in the amplitude of the CO2 seasonal cycle at both measurement sites is consistent with increasing annual mean GPP, driven in part by climate warming, but with differences in CO2 fertilization controlling the spread among the model trends. As a result, the relationship between the amplitude of the CO2 seasonal cycle and the magnitude of CO2 fertilization of GPP is almost linear across the entire ensemble of models. When combined with the observed trends in the seasonal CO2 amplitude, these relationships lead to consistent emergent constraints on the CO2 fertilization of GPP. Overall, we estimate a GPP increase of 37 ± 9 per cent for high-latitude ecosystems and 32 ± 9 per cent for extratropical ecosystems under a doubling of atmospheric CO2 concentrations on the basis of the Point Barrow and Cape Kumukahi records, respectively.


Assuntos
Atmosfera/química , Dióxido de Carbono/análise , Dióxido de Carbono/metabolismo , Mudança Climática , Modelos Teóricos , Fotossíntese , Estações do Ano , Incerteza , Alaska , Ciclo do Carbono , Ecossistema , Havaí
2.
Viruses ; 16(4)2024 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-38675830

RESUMO

The molecular mechanism of how the infecting DNA of bacteriophage T4 passes from the capsid through the bacterial cell wall and enters the cytoplasm is essentially unknown. After adsorption, the short tail fibers of the infecting phage extend from the baseplate and trigger the contraction of the tail sheath, leading to a puncturing of the outer membrane by the tail tip needle composed of the proteins gp5.4, gp5 and gp27. To explore the events that occur in the periplasm and at the inner membrane, we constructed T4 phages that have a modified gp27 in their tail tip with a His-tag. Shortly after infection with these phages, cells were chemically cross-linked and solubilized. The cross-linked products were affinity-purified on a nickel column and the co-purified proteins were identified by mass spectrometry, and we found that predominantly the inner membrane proteins DamX, SdhA and PpiD were cross-linked. The same partner proteins were identified when purified gp27 was added to Escherichia coli spheroplasts, suggesting a direct protein-protein interaction.


Assuntos
Bacteriófago T4 , Escherichia coli , Bacteriófago T4/fisiologia , Divisão Celular , Escherichia coli/virologia , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas Virais/metabolismo , Proteínas Virais/genética
3.
Dermatology ; 226(2): 138-47, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23689478

RESUMO

The number of tattooed people has substantially increased in the past years. Surveys in different countries reveal this to be up to 24% of the population. The number of reported adverse reactions after tattooing has also increased including infections, granulomatous and allergic reactions and tumors. However, the case reports do not reflect the frequency of adverse reactions. This review compares the medically documented adverse reactions published in 1991-2011 with the findings of a nation-wide survey that recently revealed the features and health problems associated with tattoos. To compare the data with the survey, the sex of patients was reported and the location and color of tattoos were evaluated. The results show clearly that colored tattoo inks are mainly responsible for adverse skin reactions and that tattoos on the extremities are involved most.


Assuntos
Tatuagem/efeitos adversos , Coleta de Dados , Feminino , Granuloma/etiologia , Humanos , Hipersensibilidade/etiologia , Infecções/transmissão , Erupções Liquenoides/etiologia , Masculino , Pele/patologia , Neoplasias Cutâneas/etiologia
4.
Australas J Dermatol ; 52(1): 43-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21332692

RESUMO

The treatment of subacute cutaneous lupus erythematosus is a therapeutic challenge. Frequently, patients are resistant to or intolerant towards single selected immunosuppressants. In combination, lower doses of methotrexate and cyclosporin A might be used to minimize toxicity. This is the first report of a successful combination of these drugs in two patients suffering from subacute cutaneous lupus erythematosus refractory to standard treatment.


Assuntos
Ciclosporina/uso terapêutico , Fármacos Dermatológicos/uso terapêutico , Lúpus Eritematoso Cutâneo/tratamento farmacológico , Metotrexato/uso terapêutico , Adulto , Quimioterapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento
5.
Contact Dermatitis ; 63(4): 223-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20831688

RESUMO

BACKGROUND: In recent years, cosmetic tattoos [permanent make-up (PMU)] on eyelids, eyebrows and lips have become increasingly popular. However, most colorants are manufactured for non-medical purposes, without any established history of safe use in humans. OBJECTIVES: To investigate severe adverse reactions, such as swelling, burning, and the development of papules, of the lips and the surrounding area in 4 patients who had had at least two PMU procedures on their lips. PATIENTS, MATERIALS AND METHODS: Adverse skin reactions were examined with patch and prick testing of the colorants. In addition, skin biopsies were taken in the centre of the prick test for histology. One patient declined prick testing. RESULTS: Beauticians tended to use various PMU products, but all contained Pigment Red 181 (CI 73360). All patients tested showed a clear delayed reaction to Pigment Red 181 or the tattoo ink, or both, after prick testing. Histology indicated an allergic reaction. Each lip lesion slowly abated after several months of topical or systemic therapy with steroids in combination with tacrolimus, but none has yet completely resolved. CONCLUSIONS: In light of the severe and often therapy-resistant skin reactions, we strongly recommend the regulation and control of the substances used in PMU colorants.


Assuntos
Corantes/efeitos adversos , Dermatite Alérgica de Contato/etiologia , Hipersensibilidade/etiologia , Pele/patologia , Tatuagem/efeitos adversos , Tiofenos/efeitos adversos , Idoso , Corantes/administração & dosagem , Técnicas Cosméticas/efeitos adversos , Cosméticos/efeitos adversos , Dermatite Alérgica de Contato/patologia , Feminino , Humanos , Hipersensibilidade/patologia , Pessoa de Meia-Idade
6.
Viruses ; 12(10)2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33036312

RESUMO

Infecting bacteriophage T4 uses a contractile tail structure to breach the envelope of the Escherichia coli host cell. During contraction, the tail tube headed with the "central spike complex" is thought to mechanically puncture the outer membrane. We show here that a purified tip fragment of the central spike complex interacts with periplasmic chaperone PpiD, which is anchored to the cytoplasmic membrane. PpiD may be involved in the penetration of the inner membrane by the T4 injection machinery, resulting in a DNA-conducting channel to translocate the phage DNA into the interior of the cell. Host cells with the ppiD gene deleted showed partial reduction in the plating efficiency of T4, suggesting a supporting role of PpiD to improve the efficiency of the infection process.


Assuntos
Bacteriófago T4/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/virologia , Peptidilprolil Isomerase/metabolismo , Proteínas da Cauda Viral/metabolismo , Membrana Celular/metabolismo , Proteínas de Escherichia coli/genética , Glicosídeo Hidrolases , Peptidilprolil Isomerase/genética , Periplasma/virologia , Proteínas do Envelope Viral/metabolismo , Ligação Viral , Internalização do Vírus
7.
Dermatology ; 217(3): 286-90, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18698141

RESUMO

BACKGROUND: Treatment of progressive disseminated essential telangiectasia and erythrosis interfollicularis colli by flashlamp pulsed dye laser frequently results in a mottled appearance and often leads to hypo- or hyperpigmentation after treatment. Furthermore, treatment is time-consuming due to the small spot size. OBJECTIVE: To report the successful removal of thin vessels in patients with the above-mentioned indications by an intense pulsed light (IPL) source. METHODS: Four patients with progressive disseminated telangiectasia on the extremities and 5 patients with erythrosis interfollicularis colli were treated with IPL. RESULTS: A clearance of up to 90% of the telangiectasias was achieved. CONCLUSION: The superficial, thin vessels of progressive disseminated essential telangiectasia and erythrosis interfollicularis colli can be successfully treated by IPL.


Assuntos
Lasers de Corante/uso terapêutico , Terapia com Luz de Baixa Intensidade , Dermatopatias Vasculares/radioterapia , Telangiectasia/radioterapia , Adulto , Feminino , Humanos , Terapia com Luz de Baixa Intensidade/efeitos adversos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
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