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1.
Climacteric ; 24(2): 128-138, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33112163

RESUMO

Despite literature pointing to a relation between dietary intake and menopausal symptoms, most studies have evaluated either only supplements or only specific nutrients or foods. Therefore, this study aimed to provide a systematic review of the literature regarding the association between dietary intake and menopausal symptoms in postmenopausal women. A systematic search was conducted across PubMed/Medline, Web of Science, Scopus, and Embase to identify studies published between 2009 and 2019. We identified 3828 studies; after screening, 73 studies were reviewed and 19 of these investigated nutrient and food intake and eating patterns associated with the intensity of menopausal symptoms. Studies evaluating diet quality or dietary patterns showed an association between lower intensity of psychological symptoms, sleep disorders, and vasomotor, urogenital, and somatic symptoms and higher consumption of vegetables, whole grains, and unprocessed foods. Also, the intensity of these symptoms is associated with high-processed foods, saturated fats, and sugars. Regarding nutrient and/or specific food, the studies indicated an association between caffeine intake and type of fat intake and the intensity of menopausal symptoms. Dietary intake was found to be associated with the severity of menopausal symptoms; however, evidence for the association between dietary intake and menopausal symptoms is inconsistent and inconclusive, and is provided by a small number of studies.


Assuntos
Dieta/efeitos adversos , Ingestão de Alimentos , Pós-Menopausa , Inquéritos sobre Dietas , Feminino , Fogachos/etiologia , Humanos , Pessoa de Meia-Idade , Índice de Gravidade de Doença
2.
Appl Environ Microbiol ; 85(20)2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31375490

RESUMO

Contamination of food during processing is recognized as a main transmission route of Listeria monocytogenes To prevent microbial contamination, biocides are widely applied as disinfectants in food processing plants. However, there are concerns about the development of antimicrobial resistance in foodborne pathogens due to widespread biocide usage. In our study, 93 L. monocytogenes isolates from German food production facilities were (i) tested for biocide and antibiotic susceptibility using broth microdilution assays, (ii) analyzed for links between reduced biocide susceptibility and antibiotic resistance, and (iii) characterized by whole-genome sequencing, including the detection of genes coding for biocide tolerance, antibiotic resistance, and other virulence factors. Fifteen L. monocytogenes isolates were tolerant to benzalkonium chloride (BAC), and genes conferring BAC tolerance were found in 13 of them. Antibiotic resistance was not associated with biocide tolerance. BAC-tolerant isolates were assigned to 6 multilocus sequence type (MLST) clonal complexes, and most of them harbored internalin A pseudogenes with premature stop codons or deletions (n = 9). Our study demonstrated a high genetic diversity among the investigated isolates including genotypes that are frequently involved in human infections. Although in vitro adaptation studies to biocides have raised concerns about increasing cross-resistance to antibiotics, our results do not provide evidence for this phenomenon in field isolates.IMPORTANCE Foodborne pathogens such as L. monocytogenes can persist in food production environments for a long time, causing perennial outbreaks. Hence, bacterial pathogens are able to survive cleaning and disinfection procedures. Accordingly, they may be repeatedly exposed to sublethal concentrations of disinfectants, which might result in bacterial adaptation to these biocides. Furthermore, antibiotic coresistance and cross-resistance are known to evolve under biocide selection pressure in vitro Hence, antimicrobial tolerance seems to play a crucial role in the resilience and persistence of foodborne pathogens in the food chain and might reduce therapeutic options in infectious diseases.


Assuntos
Antibacterianos/farmacologia , Desinfetantes/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Plantas Comestíveis/microbiologia , Compostos de Benzalcônio/farmacologia , Microbiologia de Alimentos , Genes Bacterianos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Estresse Fisiológico/genética , Virulência/genética , Fatores de Virulência/genética , Sequenciamento Completo do Genoma
3.
Int J Sports Med ; 37(10): 813-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27286183

RESUMO

This study aims to analyze the neuromuscular adaptations of sedentary young women between water-based resistance training performed with single and multiple sets. 66 women (24.72±4.33 years old) were randomly divided into 2 training groups: SS (single set of 30 s) and MS (3 sets of 30 s). Both groups performed 2 sessions per week for 10 weeks. One repetition maximal test (1RM), muscle endurance test (maximal repetitions at 60% 1RM) and muscle power test (squat and countermovement jump performance) were evaluated at pre- and post-training. To compare neuromuscular variables, a repeated measures ANOVA with a group factor (α=0.05) was used. Both groups showed significant increases in 1RM (SS: 14.59%; MS 14.86%), in 60% 1RM (SS: 31.23%; MS: 37.37%), in SJ (SS: 10.9%; MS: 8.3%) and CMJ (SS: 9.1%; MS: 6.8%), without difference between groups. There can be concluded that young and sedentary women presented improvements in different expressions of strength after 10 weeks of training, regardless the volume of training.


Assuntos
Adaptação Fisiológica/fisiologia , Força Muscular/fisiologia , Resistência Física/fisiologia , Treinamento Resistido/métodos , Adolescente , Adulto , Feminino , Humanos , Músculo Esquelético/fisiologia , Comportamento Sedentário , Água , Adulto Jovem
4.
Indian Pediatr ; 53(2): 170-1, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26897159

RESUMO

This study aims to evaluate the prevalence of inappropriate postural habits in students. 827 Brazilian students aged 14 to 19 were evaluated with a self-administered questionnaire. A high prevalence of (>90%) inappropriate habits in sitting postures (on a chair, to write, and at a computer) and picking up an object off the floor was observed, suggesting the need to develop preventive programs.


Assuntos
Saúde do Adolescente/estatística & dados numéricos , Postura/fisiologia , Estudantes/estatística & dados numéricos , Adolescente , Adulto , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Inquéritos e Questionários , Adulto Jovem
5.
Eur J Trauma Emerg Surg ; 36(5): 417-26, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21841953

RESUMO

BACKGROUND: Biomechanical research directed at developing customized implant solutions for rib fracture fixation is essential to reduce the complexity and to increase the reliability of rib osteosynthesis. Without a simple and reliable implant solution, surgical stabilization of rib fractures will remain underutilized despite proven benefits for select indications. This article summarizes the research, development, and testing of a specialized and comprehensive implant solution for rib fracture fixation. METHODS: An implant system for rib fracture fixation was developed in three phases: first, research on rib biomechanics was conducted to better define the form and function of ribs. Second, research results were implemented to derive an implant system comprising anatomical plates and intramedullary rib splints. Third, the functionality of anatomic plates and rib splints was evaluated in a series of biomechanical tests. RESULTS: Geometric analysis of the rib surface yielded a set of anatomical rib plates that traced the rib surface over a distance of 13-15 cm without the need for plate contouring. Structurally, the flexible design of anatomic plates did not increase the native stiffness of ribs while restoring 77% of the native rib strength. Intramedullary rib splints with a rectangular cross-section provided 48% stronger fracture fixation than traditional intramedullary fixation with Kirschner wires. CONCLUSION: The anatomic plate set can simplify rib fracture fixation by minimizing the need for plate contouring. Intramedullary fixation with rib splints provides a less-invasive fixation alternative for posterior rib fracture, where access for plating is limited. The combination of anatomic plates and intramedullary splints provides a comprehensive system to manage the wide range of fractures encountered in flail chest injuries.

6.
Biochem Biophys Res Commun ; 333(1): 142-9, 2005 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-15939402

RESUMO

Bone adapts to mechanical load by osteosynthesis, suggesting that osteoblasts might respond to mechanical stimuli. We therefore investigated cell proliferation and phospholipase C (PLC) expression in osteoblasts. One Hertz uniaxial stretching at 4000 microstrains significantly increased the proliferation rates of human osteoblast-like osteosarcoma cell line MG-63 and primary human osteoblasts. However, U-2/OS, SaOS-2, OST, and MNNG/HOS cells showed no significant changes in proliferation rate. We investigated the expression pattern of different isoforms of PLC in these cell lines. We were able to detect PLC beta1, beta3, gamma1, gamma2, and delta1 in all cells, but PLC beta2 was only detectable in the mechanosensitive cells. We therefore investigated the possible role of PLC beta2 in mechanotransduction. Inducible antisense expression for 24h inhibited the translation of PLC beta1 in U-2/OS cells by 35% and PLC beta2 in MG-63 by 29%. Fluid shear flow experiments with MG-63 lacking PLC beta2 revealed a significantly higher level of cells losing attachment to coverslips and a significantly lower number of cells increasing intracellular free calcium.


Assuntos
Isoenzimas/metabolismo , Mecanotransdução Celular , Osteoblastos/fisiologia , Osteossarcoma/fisiopatologia , Estimulação Física/métodos , Fosfolipases Tipo C/metabolismo , Adesão Celular , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Humanos , Fosfolipase C beta
7.
Zentralbl Neurochir ; 64(2): 76-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12838476

RESUMO

UNLABELLED: A 44-years old man developed TIA-like symptoms with dysaesthesia around the mouth, vertigo and diplopia. MRI revealed a cystic space-occupying lesion on the right Meckel's cave, which spread out into cerebellopontine angle in a further examination. Therefore surgical exploration was performed using a suboccipital approach. An arachnoidal cyst was found and removed including its wall. About three months later the patient suffered again from dysaesthesias of the right side of the face and a new MRI revealed a recurrence of the lesion, with extension into the cerebellopontine angle, too. Surgical revision was done using the same approach and the recurrent cyst was removed. Postoperatively, there were a transient hypaesthesia in the distribution area of the right trigeminal nerve and a light pulmonary embolism occurred as a complication. No symptoms have returned during an observation period of 15 months. CONCLUSION: An arachnoidal cyst must be considered as a rare cause, when a lesion is found at the Meckel's cave with intermittent clinical symptoms of a trigeminal nerve affection. As surgical treatment we favour fenestration and cyst wall resection.


Assuntos
Cistos Aracnóideos/patologia , Isquemia Encefálica/patologia , Tronco Encefálico/irrigação sanguínea , Adulto , Cistos Aracnóideos/diagnóstico , Cistos Aracnóideos/cirurgia , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/cirurgia , Tronco Encefálico/fisiopatologia , Ângulo Cerebelopontino/irrigação sanguínea , Ângulo Cerebelopontino/patologia , Circulação Cerebrovascular/fisiologia , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Masculino , Síndromes de Compressão Nervosa/diagnóstico , Síndromes de Compressão Nervosa/patologia , Fibras Nervosas/fisiologia , Procedimentos Neurocirúrgicos , Parestesia/etiologia , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/psicologia , Recidiva , Doenças do Nervo Trigêmeo/diagnóstico , Doenças do Nervo Trigêmeo/etiologia , Doenças do Nervo Trigêmeo/patologia
8.
Braz. j. biol ; 62(4a): 565-571, Nov. 2002. graf
Artigo em Inglês | LILACS | ID: lil-335611

RESUMO

Water mite (Krendowskia sp.) predation on zooplanktonic species from Lake Monte Alegre (Säo Paulo State, Brazil) was tested in laboratory experiments. One cladoceran, Daphnia gessneri, two copepods, Tropocyclops prasinus and Thermocyclops decipiens, and Chaoborus larvae III and IV were supplied as prey to adult mites. The cladoceran Ceriodaphnia cornuta was used in the experiment with mite nymphs. Only D.gessneri was preyed on by mites, at an average rate of 7 ind./mite/day, at 23-24ºC. Although Chaoborus was not eaten by the predator in the experiment, in direct observations older larvae were seen to be seized by several mites, both predators and prey sinking to the bottom of the vessel. Adult Daphnia was grabbed by its dorsal side, swimming together with the mite. There was an increase in predatory activity two hours after sunset


Assuntos
Animais , Crustáceos , Ácaros , Comportamento Predatório , Zooplâncton , Estações do Ano
9.
Microbiology (Reading) ; 148(Pt 2): 497-506, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11832513

RESUMO

The individual and synergistic contributions of two transcription factors, EFG1 and CPH1, have been characterized with regard to adhesion to, and invasion of, human epithelia by Candida albicans. For this purpose two in vitro reconstructed tissue models were developed. A multi-layered model of human epidermis was used to simulate superficial infections of the skin, whereas a reconstructed human intestinal model was used to mimic the first steps of systemic infections. It was shown that C. albicans deleted for both transcription factors CPH1 and EFG1, in contrast to the congenic clinical isolate Sc5314, was neither able to adhere to, nor to penetrate, either of the model systems. A strain deleted for EFG1 alone showed significant reduction in adhesion and was not able to penetrate through the stratum corneum. However, strains deleted for CPH1 showed phenotypes paralleling the phenotypes of the clinical isolate Sc5314. Using different types of multi-layered human tissues reconstructed in vitro the individual contributions of Efg1p and Cph1p to two important virulence factors of C. albicans, namely adhesion and invasion, could be defined.


Assuntos
Candida albicans/fisiologia , Candida albicans/patogenicidade , Proteínas de Ligação a DNA/fisiologia , Proteínas Fúngicas/fisiologia , Fatores de Transcrição/fisiologia , Candida albicans/genética , Candida albicans/isolamento & purificação , Adesão Celular/fisiologia , Técnicas de Cultura , Proteínas de Ligação a DNA/genética , Epitélio/microbiologia , Proteínas Fúngicas/genética , Deleção de Genes , Genes Fúngicos , Humanos , Intestinos/microbiologia , Modelos Biológicos , Fenótipo , Pele/microbiologia , Fatores de Transcrição/genética , Virulência
10.
Braz J Biol ; 62(4A): 565-71, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12659004

RESUMO

Water mite (Krendowskia sp.) predation on zooplanktonic species from Lake Monte Alegre (São Paulo State, Brazil) was tested in laboratory experiments. One cladoceran, Daphnia gessneri, two copepods, Tropocyclops prasinus and Thermocyclops decipiens, and Chaoborus larvae III and IV were supplied as prey to adult mites. The cladoceran Ceriodaphnia cornuta was used in the experiment with mite nymphs. Only D. gessneri was preyed on by mites, at an average rate of 7 ind./mite/day, at 23-24 degrees C. Although Chaoborus was not eaten by the predator in the experiment, in direct observations older larvae were seen to be seized by several mites, both predators and prey sinking to the bottom of the vessel. Adult Daphnia was grabbed by its dorsal side, swimming together with the mite. There was an increase in predatory activity two hours after sunset.


Assuntos
Crustáceos , Ácaros/fisiologia , Comportamento Predatório/fisiologia , Zooplâncton , Animais , Estações do Ano
11.
Braz. j. biol ; 62(4)2002.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467647

RESUMO

Water mite (Krendowskia sp.) predation on zooplanktonic species from Lake Monte Alegre (São Paulo State, Brazil) was tested in laboratory experiments. One cladoceran, Daphnia gessneri, two copepods, Tropocyclops prasinus and Thermocyclops decipiens, and Chaoborus larvae III and IV were supplied as prey to adult mites. The cladoceran Ceriodaphnia cornuta was used in the experiment with mite nymphs. Only D.gessneri was preyed on by mites, at an average rate of 7 ind./mite/day, at 23-24ºC. Although Chaoborus was not eaten by the predator in the experiment, in direct observations older larvae were seen to be seized by several mites, both predators and prey sinking to the bottom of the vessel. Adult Daphnia was grabbed by its dorsal side, swimming together with the mite. There was an increase in predatory activity two hours after sunset.


A predação do zooplâncton por ácaros aquáticos (Krendowskia sp.) do Lago Monte Alegre (Estado de São Paulo, Brasil) foi testada em experimentos de laboratório. Um cladócero, Daphnia gessneri, dois copépodos, Tropocyclops prasinus e Thermocyclops decipiens e larvas III e IV de Chaoborus foram oferecidos como presas a ácaros adultos. O cladócero Ceriodaphnia cornuta foi usado em experimentos com ninfas de ácaros. Apenas D. gessneri foi predada pelos ácaros, a uma taxa média de 7 ind./ácaro/dia, a 23-24ºC. Embora Chaoborus não tenha sido comido pelo predador no experimento, nas observações diretas, grupos de ácaros foram vistos agarrados a larvas III e IV. Ao agarrarem os caoborídeos, os ácaros paravam de nadar e afundavam com a presa. Ainda nas observações diretas, os ácaros foram vistos agarrados ao dorso de Daphnia adultas e, nesta ocasião, continuavam nadando com a presa. Foi observado aumento na atividade predatória duas horas após o pôr-do-sol.

12.
Development ; 128(17): 3307-19, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11546747

RESUMO

Ectopic expression of transcription factors in eye-antennal discs of Drosophila strongly interferes with their developmental program. Early ectopic expression in embryonic discs interferes with the developmental pathway primed by Eyeless and generates headless flies, which suggests that Eyeless is necessary for initiating cell proliferation and development of both the eye and antennal disc. Interference occurs through a block in the cell cycle that for some ectopic transcription factors is overcome by D-CycE or D-Myc. Late ectopic expression in cone cell precursors interferes with their differentiation. We propose that this developmental pathway interference is a general surveillance mechanism that eliminates most aberrations in the genetic program during development and evolution, and thus seriously restricts the pathways that evolution may take.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Proteínas de Drosophila , Proteínas de Insetos/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Proteínas Nucleares , Transativadores/fisiologia , Fatores de Transcrição/fisiologia , Animais , Sítios de Ligação , Divisão Celular , Ciclina E/metabolismo , Proteínas de Ligação a DNA/genética , Drosophila melanogaster/crescimento & desenvolvimento , Olho/crescimento & desenvolvimento , Expressão Gênica , Cabeça/crescimento & desenvolvimento , Proteínas de Insetos/genética , Proteínas do Tecido Nervoso/genética , Fator de Transcrição PAX2 , Fatores de Transcrição Box Pareados , Fenótipo , Transativadores/genética , Fatores de Transcrição/genética , Ativação Transcricional
13.
Mol Ther ; 3(1): 14-23, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11162306

RESUMO

Fanconi anemia (FA) is an autosomal recessive disorder characterized by birth defects, increased incidence of malignancy, progressive bone marrow failure, and cellular hypersensitivity to DNA cross-linking agents. Bone marrow transplantation is therapeutic and therefore FA is a candidate disease for hematopoietic gene therapy. We have previously used mitomycin C (MMC) to achieve in vivo selection of wild-type hematopoietic stem cells (HSC) transplanted into FANCC knockout mice. However, clinical application of MMC in human FA gene therapy is unlikely because of its unknown toxicity profile in human FA patients. In contrast, cyclophosphamide (CPA) and gamma-irradiation (IR) are already in use with human FA patients and we therefore tested these regimens for their ability to achieve selection of genetically corrected HSCs in vivo. We found that nonmyeloablative doses of CPA or IR or combinations of CPA + IR were highly efficient at achieving in vivo selection of transplanted wild-type HSC. Furthermore, this nontoxic regimen also selected FANCC-mutant HSC corrected by ex vivo retroviral gene therapy. We suggest those nontoxic doses of CPA and/or IR could also be used to enhance gene therapy in human FA patients.


Assuntos
Anemia de Fanconi/terapia , Terapia Genética/métodos , Células-Tronco Hematopoéticas/metabolismo , Células 3T3 , Animais , Southern Blotting , Células da Medula Óssea/metabolismo , Células Cultivadas , Terapia Combinada , Ciclofosfamida/farmacologia , Relação Dose-Resposta a Droga , Anemia de Fanconi/genética , Feminino , Raios gama , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunossupressores/farmacologia , Masculino , Camundongos , Camundongos Mutantes , Fenótipo , Radiação Ionizante , Retroviridae/genética , Fatores de Tempo
14.
Development ; 128(3): 395-405, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11152638

RESUMO

The Drosophila segmentation gene paired, whose product is homologous to the Drosophila Gooseberry and mammalian Pax3 proteins, has three general functions: proper development of the larval cuticle, survival to adulthood and male fertility. Both DNA-binding domains, the conserved N-terminal paired-domain and prd-type homeodomain, are required within the same molecule for all general paired functions, whereas a conserved His-Pro repeat located near its C terminus is a transactivation domain potentiating these functions. The C-terminal moiety of Paired includes two additional functional motifs: one, also present in Gooseberry and Pax3, is required for segmentation and cuticle development; the other, retained only in Gooseberry, is necessary for survival. The male fertility function, which cannot be replaced by Gooseberry and Pax3, is specified by the conserved N-terminal rather than the divergent C-terminal moiety of Paired. We conclude that the functional diversification of paired, gooseberry and Pax3, primarily determined by variations in their enhancers, is modified by adaptations of their coding regions as a necessary consequence of their newly acquired spatiotemporal expression.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila , Drosophila melanogaster/embriologia , Proteínas de Homeodomínio/metabolismo , Proteínas de Insetos/metabolismo , Proteínas Nucleares , Transativadores , Fatores de Transcrição , Motivos de Aminoácidos , Animais , Animais Geneticamente Modificados , Sequência Conservada/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Drosophila melanogaster/genética , Fertilidade/genética , Regulação da Expressão Gênica no Desenvolvimento , Genes Essenciais/genética , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/genética , Imuno-Histoquímica , Proteínas de Insetos/química , Proteínas de Insetos/genética , Íntrons/genética , Masculino , Mutação/genética , Fator de Transcrição PAX3 , Fatores de Transcrição Box Pareados , Fenótipo , Estrutura Terciária de Proteína , Sequências Repetitivas de Aminoácidos , Ativação Transcricional , Transgenes/genética
15.
Phys Med ; 17 Suppl 1: 128-30, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11770528

RESUMO

The Atominstitute of the Austrian Universities developed the HTR-method for determination of absorbed dose and "averaged" linear energy transfer (LET) in mixed radiation fields. The method was applied with great success during several space missions (e.g. STS-60, STS-63, BION-10 and BION-11) and on space station MIR in the past 10 years. It utilises the changes of peak height ratios in LiF thermoluminescent glowcurves in dependence on the LET. Due to the small size of these dosemeters the HTR-method can be used also for measurements inside tissue equivalent phantoms. A water filled phantom with a diameter of 35 cm containing four channels where dosemeters can be exposed in different depths was developed by the Institute for Biomedical Problems. This opens the possibility to measure the depth distribution of the average LET and the dose equivalent simultaneously. During phase 1 dosemeters were exposed for 271 days (05.1997-02.1998) in 6 different depths inside the phantom, which was positioned in the commander cabin. In phase 2 dosemeters were exposed in 2 channels in 6 different depths for 102 days (05.1998-08.1998) in the board engineer cabin, following an exposure in different channels in 3 different depths for 199 days (08.1998- 02.1999) in the Modul KWANT 2.


Assuntos
Transferência Linear de Energia , Imagens de Fantasmas , Monitoramento de Radiação/métodos , Voo Espacial/instrumentação , Astronave/instrumentação , Humanos , Doses de Radiação , Dosimetria Termoluminescente , Água
16.
Development ; 127(21): 4729-41, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11023875

RESUMO

The stereotyped pattern of veins in the Drosophila wing is generated in response to local EGF signalling. Mutations in the rhomboid (rho) gene, which encodes a sevenpass membrane protein required to enhance signalling transmitted by the EGF receptor (Egfr), inhibit vein development and disrupt the vein pattern. By contrast, net mutations produce ectopic veins in intervein regions. We have cloned the net gene and show that it encodes a basic HLH protein that probably acts as a transcriptional repressor. net and rho are expressed in mutually exclusive patterns during the development of the wing imaginal disc. Lack of net activity causes rho expression to expand, and vice versa. Furthermore, ectopic expression of net or rho results in their mutual repression and thus suppresses vein formation or generates tube-like wings composed of vein-like tissue. Egfr signalling and net exert mutually antagonising activities during the specification of vein versus intervein fate. While Egfr signalling represses net transcription, net exhibits a two-tiered control by repressing rho transcription and interfering with Egfr signalling downstream of Rho. Our results further suggest that net is required to maintain intervein development by restricting Egfr signalling, which promotes vein development, to the Net-free vein regions of the wing disc.


Assuntos
Padronização Corporal/genética , Proteínas de Drosophila , Proteínas de Membrana/genética , Proteínas Repressoras/genética , Asas de Animais/crescimento & desenvolvimento , Sequência de Aminoácidos , Animais , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Passeio de Cromossomo , Receptores ErbB/genética , Regulação da Expressão Gênica no Desenvolvimento , Sequências Hélice-Alça-Hélice , Humanos , Hormônios de Inseto/genética , Dados de Sequência Molecular , Pupa , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais
17.
Cell ; 103(1): 75-85, 2000 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-11051549

RESUMO

How multifunctional signals combine to specify unique cell fates during pattern formation is not well understood. Here, we demonstrate that together with the transcription factor Lozenge, the nuclear effectors of the EGFR and Notch signaling pathways directly regulate D-Pax2 transcription in cone cells of the Drosophila eye disc. Moreover, the specificity of D-Pax2 expression can be altered upon genetic manipulation of these inputs. Thus, a relatively small number of temporally and spatially controlled signals received by a set of pluripotent cells can create the unique combinations of activated transcription factors required to regulate target genes and ultimately specify distinct cell fates within this group. We expect that similar mechanisms may specify pattern formation in vertebrate developmental systems that involve intercellular communication.


Assuntos
Padronização Corporal/genética , Linhagem da Célula/genética , Proteínas de Drosophila , Drosophila/embriologia , Drosophila/genética , Olho/embriologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Transdução de Sinais/genética , Animais , Sequência de Bases/genética , Diferenciação Celular/genética , Células Clonais/citologia , Células Clonais/metabolismo , Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos/genética , Receptores ErbB/genética , Receptores ErbB/metabolismo , Olho/metabolismo , Olho/ultraestrutura , Genes de Insetos/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Fator de Transcrição PAX2 , Receptores Notch , Células Fotorreceptoras Retinianas Cones/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Fatores de Transcrição/genética
18.
Mol Cell ; 6(2): 457-65, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10983991

RESUMO

Hedgehog signaling, mediated through its Patched-Smoothened receptor complex, is essential for pattern formation in animal development. Activating mutations within Smoothened have been associated with basal cell carcinoma, suggesting that smoothened is a protooncogene. Thus, regulation of Smoothened levels might be critical for normal development. We show that Smoothened protein levels in Drosophila embryos are regulated posttranscriptionally by a mechanism dependent on Hedgehog signaling but not on its nuclear effector Cubitus interruptus. Hedgehog signaling upregulates Smoothened levels, which are otherwise downregulated by Patched. Demonstrating properties of a self-correcting system, the Hedgehog signaling pathway adjusts the concentrations of Smoothened and Patched to each other and to that of the Hedgehog signal, which ensures that activation of Hedgehog target genes by Smoothened signaling becomes strictly dependent on Hedgehog.


Assuntos
Proteínas de Drosophila , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/fisiologia , Receptores de Superfície Celular/genética , Receptores Acoplados a Proteínas G , Proteínas de Saccharomyces cerevisiae , Animais , Animais Geneticamente Modificados , Padronização Corporal , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Ligação a DNA , Embrião não Mamífero/fisiologia , Proteínas Fúngicas/genética , Proteínas Hedgehog , Temperatura Alta , Proteínas de Membrana/fisiologia , Mutagênese , Receptores de Superfície Celular/fisiologia , Transdução de Sinais , Receptor Smoothened , Fatores de Transcrição/genética
19.
Isis ; 91(2): 283-304, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10967876

RESUMO

The theological doctrine of biblical inerrancy is the intellectual basis for modern creation science. Yet Benjamin Breckinridge Warfield of Princeton Theological Seminary, the theologian who more than any other defined modern biblical inerrancy, was throughout his life open to the possibility of evolution and at some points an advocate of the theory. Throughout a long career Warfield published a number of major papers on these subjects, including studies of Darwin's religious life, on the theological importance of the age of humanity (none) and the unity of the human species (much), and on Calvin's understanding of creation as proto-evolutionary. He also was an engaged reviewer of many of his era's important books by scientists, theologians, and historians who wrote on scientific research in relation to traditional Christianity. Exploration of Warfield's writing on science generally and evolution in particular retrieves for historical consideration an important defender of mediating positions in the supposed war between science and religion.


Assuntos
Bíblia , Evolução Biológica , Cristianismo/história , Clero/história , Pessoas Famosas , Religião e Ciência , Docentes/história , História do Século XIX , História do Século XX , Humanos , Estados Unidos
20.
IUBMB Life ; 49(4): 297-302, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10995032

RESUMO

All cells have developed various mechanisms to regulate precisely the availability of important micronutrients such as zinc and copper; in many cells, this regulation is mediated by P1-type ATPases. Most of the P1-ATPases have been described very recently, and little is known about their molecular mechanism and regulation. Here, we demonstrate that the expression of ZntA, a Zn,Cd-transporting P-type ATPase of Escherichia coli, is specifically regulated by the transported cations, cadmium and zinc. Nickel, cobalt, and copper did not induce the expression of ZntA, even when present at concentrations as high as 0.6-1 mM. The effect of zinc and cadmium on the ZntA expression is concentration dependent, the apparent Km for Cd (19 microM) being markedly lower than that for Zn (100 microM). This metal selectivity is opposite to the known metal selectivity of transport by ZntA. Thus, we speculate that, to maintain zinc concentrations in the cell in the presence of cadmium, ZntA probably interacts with other proteins that modulate the ZntA selectivity towards transported cations.


Assuntos
Adenosina Trifosfatases/biossíntese , Cádmio/metabolismo , Zinco/metabolismo , Cátions , Cobalto/metabolismo , Cobre/metabolismo , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Escherichia coli/enzimologia , Cinética , Níquel/metabolismo , Plasmídeos/metabolismo
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