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1.
BMC Psychiatry ; 20(1): 108, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143714

RESUMO

BACKGROUND: Physical inactivity is a key contributor to the global burden of disease and disproportionately impacts the wellbeing of people experiencing mental illness. Increases in physical activity are associated with improvements in symptoms of mental illness and reduction in cardiometabolic risk. Reliable and valid clinical tools that assess physical activity would improve evaluation of intervention studies that aim to increase physical activity and reduce sedentary behaviour in people living with mental illness. METHODS: The five-item Simple Physical Activity Questionnaire (SIMPAQ) was developed by a multidisciplinary, international working group as a clinical tool to assess physical activity and sedentary behaviour in people living with mental illness. Patients with a DSM or ICD mental illness diagnoses were recruited and completed the SIMPAQ on two occasions, one week apart. Participants wore an Actigraph accelerometer and completed brief cognitive and clinical assessments. RESULTS: Evidence of SIMPAQ validity was assessed against accelerometer-derived measures of physical activity. Data were obtained from 1010 participants. The SIMPAQ had good test-retest reliability. Correlations for moderate-vigorous physical activity was comparable to studies conducted in general population samples. Evidence of validity for the sedentary behaviour item was poor. An alternative method to calculate sedentary behaviour had stronger evidence of validity. This alternative method is recommended for use in future studies employing the SIMPAQ. CONCLUSIONS: The SIMPAQ is a brief measure of physical activity and sedentary behaviour that can be reliably and validly administered by health professionals.


Assuntos
Exercício Físico , Transtornos Mentais , Comportamento Sedentário , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Inquéritos e Questionários , Adulto Jovem
2.
Cryo Letters ; 37(5): 335-345, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27925001

RESUMO

BACKGROUND: Mice are fundamental models of study due to their ease of breeding, manipulation, and the well-studied genome. There has been extensive research focused on the cryopreservation of mouse germaplasm, as a way to help maintain the different transgenic mouse breeds. The first protocols for mouse sperm were developed in the 90's using slow cooling and a mixture of raffinose and glycerol. Since then, the rate of success reported remains highly variable. OBJECTIVE: The Aim of this work is to study factors that are key for developing vitrification protocols for ultra-rapid laser warming of mouse sperm. RESULTS: Our results show that due to the exquisite sensitivity of sperm cells to osmotic excursions, our target levels of dehydration (~85% water content) cannot be achieved without causing a significant decrease in sperm motility and membrane fusion. CONCLUSION: It seems likely that mouse sperm vitrification is going to be difficult to develop due to the exquisite sensitivity of mouse sperm cells to handling and dehydration.


Assuntos
Criopreservação/métodos , Dessecação/métodos , Preservação do Sêmen/métodos , Espermatozoides/fisiologia , Vitrificação , Animais , Temperatura Alta , Lasers , Masculino , Camundongos , Camundongos Endogâmicos ICR
3.
Eur J Vasc Endovasc Surg ; 43(5): 588-93, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22436266

RESUMO

OBJECTIVE: Folic acid (FA) administration can reduce plasma total homocysteine (tHcy); however, it fails to decrease cardiovascular events and progression of peripheral artery disease (PAD). Nɛ-homocysteinyl-lysine isopeptide (Nɛ-Hcy-Lys) is formed during catabolism of homocysteinylated proteins. We sought to investigate factors that determine the presence of Nɛ-Hcy-Lys in PAD patients with hyperhomocysteinemia receiving FA. PATIENTS AND METHODS: We studied 131 consecutive PAD patients with tHcy > 15 µmol l(-1) taking FA 0.4 mg d(-1) for 12 months. Serum Nɛ-Hcy-Lys was determined by high-performance liquid chromatography (HPLC). We also measured interleukin-6 (IL-6), plasminogen activator inhibitor-1 (PAI-1), asymmetric dimethylarginine (ADMA) and 8-iso-prostaglandin F(2α) (8-iso-PGF(2α)). RESULTS: FA administration resulted in a 70.5% decrease in tHcy (p < 0.0001). However, serum Nɛ-Hcy-Lys was detectable in 28 (21.4%) patients on FA who were more frequently current smokers and survivors of ischaemic stroke (p < 0.001). They had higher tHcy by 46.0%, PAI-1 by 51.7%, 8-iso-PGF(2α) by 59.1% and ADMA by 26.4% (all, p < 0.0001). The presence of Nɛ-Hcy-Lys was associated with lower ankle-brachial index (ABI) values (p < 0.001) and higher prevalence of cardiovascular events (p < 0.001) following therapy. CONCLUSION: The presence of Nɛ-Hcy-Lys in one-fifth of hyperhomocysteinemic individuals with PAD despite FA treatment is associated with progression of PAD and with increased ADMA formation, oxidative stress and hypofibrinolysis.


Assuntos
Homocisteína/metabolismo , Hiper-Homocisteinemia/metabolismo , Peptídeos/metabolismo , Doença Arterial Periférica/fisiopatologia , Proteínas/metabolismo , Complexo Vitamínico B/administração & dosagem , Idoso , Progressão da Doença , Feminino , Ácido Fólico/administração & dosagem , Homocisteína/sangue , Humanos , Hiper-Homocisteinemia/sangue , Hiper-Homocisteinemia/tratamento farmacológico , Masculino , Metabolismo , Pessoa de Meia-Idade , Estresse Oxidativo , Peptídeos/sangue , Doença Arterial Periférica/sangue , Doença Arterial Periférica/metabolismo
4.
Phys Rev Lett ; 105(26): 261803, 2010 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-21231645

RESUMO

We report results from a search for chameleon particles created via photon-chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of unexplored chameleon power-law and dark energy models. These results exclude 5 orders of magnitude in the coupling of chameleons to photons covering a range of 4 orders of magnitude in chameleon effective mass and, for individual models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.

5.
J Cell Biol ; 57(3): 729-42, 1973 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-4572921

RESUMO

Freeze-cleaving can be used as a direct probe to examine the ultrastructural alterations of biological material due to freezing. We examined the thesis that at least two factors, which are oppositely dependent upon cooling velocity, determine the survival of cells subjected to freezing. According to this thesis, when cells are cooled at rates exceeding a critical velocity, a decrease in viability is caused by the presence of intracellular ice; but cells cooled at rates less than this critical velocity do not contain appreciable amounts of intracellular ice and are killed by prolonged exposure to a solution that is altered by the presence of ice. As a test of this hypothesis, we examined freeze-fractured replicas of the yeast Saccharomyces cerevisiae after suspensions had been cooled at rates ranging from 1.8 to 75,000 degrees C/min. Some of the frozen samples were cleaved and replicated immediately in order to minimize artifacts due to sample handling. Other samples were deeply etched or were rewarmed to -20 degrees C and recooled before replication. Yeast cells cooled at or above the rate necessary to preserve maximal viability ( approximately 7 degrees C/min) contained intracellular ice, whereas cells cooled below this rate showed no evidence of intracellular ice.


Assuntos
Técnica de Congelamento e Réplica , Saccharomyces cerevisiae/citologia , Sobrevivência Celular , Cristalização , Gelo , Cloreto de Sódio
6.
Science ; 178(4059): 411-4, 1972 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-5077328

RESUMO

Mouse embryos survived freezing to -196 degrees C. Survival required slow cooling (0.3 degrees to 2 degrees C per minute) and slow warming (4 degrees to 25 degrees C per minute). Depending on the specific rates used, 50 to 70 percent of more than 2500 frozen and thawed early embryos developed into blastocysts in culture after storage at -196 degrees C for up to 8 days. When approximately 1000 of the survivors, including some frozen to -269 degrees C (4 degrees K), were transferred into foster mothers, 65 percent of the recipients became pregnant. More than 40 percent of the embryos in these pregnant mice gave rise to normal, living full-term fetuses or newborn mice.


Assuntos
Embrião de Mamíferos , Congelamento , Preservação de Tecido , Animais , Dimetil Sulfóxido , Implantação do Embrião , Transferência Embrionária , Desenvolvimento Embrionário e Fetal , Feminino , Idade Gestacional , Hibridização Genética , Masculino , Métodos , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Gravidez , Temperatura , Fatores de Tempo , Sobrevivência de Tecidos , Transplante Homólogo
7.
Science ; 258(5090): 1932-5, 1992 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-1470915

RESUMO

The inability to cryobiologically preserve the fruit fly Drosophila melanogaster has required that fly stocks be maintained by frequent transfer of adults. This method is costly in terms of time and can lead to loss of stocks. Traditional slow freezing methods do not succeed because the embryos are highly sensitive to chilling. With the procedures described here, 68 percent of precisely staged 15-hour Oregon R (wild-type) embryos hatch after vitrification at -205 degrees C, and 40 percent of the resulting larvae develop into normal adult flies. These embryos are among the most complex organisms successfully preserved by cryobiology.


Assuntos
Criopreservação/métodos , Drosophila melanogaster/embriologia , Embrião não Mamífero/citologia , Animais , Drosophila melanogaster/citologia , Embrião não Mamífero/fisiologia , Desenvolvimento Embrionário e Fetal , Fatores de Tempo
8.
MethodsX ; 6: 534-539, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30963033

RESUMO

We propose a complex 4-point method for characterization of flow batteries. The distribution of ohmic and faradaic losses within a single-cell is evaluated from electrochemical impedance spectra and load curves of positive and negative half-cells measured with platinum wire pseudo-reference electrodes positioned in respective electrode compartment. The developed method can be used e.g., for the component screening and in-situ durability studies on single-cell scale. The method was validated on a vanadium redox flow battery single-cell; however, it can be analogically employed for various chemistries of flow battery. •Complex 4-point method for characterization of flow battery single-cell was developed.•Method is based on electrochemical impedance spectra and load curve measurements.•Direct evaluation of ohmic and faradaic losses distribution within battery single-cell by the method.

10.
Mol Cell Biol ; 15(10): 5671-81, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7565718

RESUMO

1,3-beta-D-Glucan is a major structural polymer of yeast and fungal cell walls and is synthesized from UDP-glucose by the multisubunit enzyme 1,3-beta-D-glucan synthase. Previous work has shown that the FKS1 gene encodes a 215-kDa integral membrane protein (Fks1p) which mediates sensitivity to the echinocandin class of antifungal glucan synthase inhibitors and is a subunit of this enzyme. We have cloned and sequenced FKS2, a homolog of FKS1 encoding a 217-kDa integral membrane protein (Fks2p) which is 88% identical to Fks1p. The residual glucan synthase activity present in strains with deletions of fks1 is (i) immunodepleted by antibodies prepared against FKS2 peptides, demonstrating that Fks2p is also a component of the enzyme, and (ii) more sensitive to the echinocandin L-733,560, explaining the increased sensitivity of fks1 null mutants to this drug. Simultaneous disruption of FKS1 and FKS2 is lethal, suggesting that Fks1p and Fks2p are alternative subunits with essential overlapping function. Analysis of FKS1 and FKS2 expression reveals that transcription of FKS1 is regulated in the cell cycle and predominates during growth on glucose, while FKS2 is expressed in the absence of glucose. FKS2 is essential for sporulation, a process which occurs during nutritional starvation. FKS2 is induced by the addition of Ca2+ to the growth medium, and this induction is completely dependent on the Ca2+/calmodulin-dependent phosphoprotein phosphatase calcineurin. We have previously shown that growth of fks1 null mutants is highly sensitive to the calcineurin inhibitors FK506 and cyclosporin A. Expression of FKS2 from the heterologous ADH1 promoter results in FK506-resistant growth. Thus, the sensitivity of fks1 mutants to these drugs can be explained by the calcineurin-dependent transcription of FKS2. Moreover, FKS2 is also highly induced in response to pheromone in a calcineurin-dependent manner, suggesting that FKS2 may also play a role in the remodeling of the cell wall during the mating process.


Assuntos
Glucosiltransferases/metabolismo , Proteínas de Membrana/biossíntese , Proteínas de Membrana/fisiologia , Peptídeos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/enzimologia , Proteínas de Schizosaccharomyces pombe , Sequência de Aminoácidos , Antibacterianos/farmacologia , Sequência de Bases , Calcineurina , Cálcio/farmacologia , Proteínas de Ligação a Calmodulina/antagonistas & inibidores , Proteínas de Ligação a Calmodulina/fisiologia , Clonagem Molecular , Equinocandinas , Indução Enzimática/efeitos dos fármacos , Proteínas Fúngicas/genética , Genes Fúngicos/genética , Glucosiltransferases/antagonistas & inibidores , Glucosiltransferases/genética , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Dados de Sequência Molecular , Feromônios/farmacologia , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/fisiologia , RNA Fúngico/biossíntese , RNA Mensageiro/biossíntese , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Esporos Fúngicos , Tacrolimo/farmacologia , Transcrição Gênica/efeitos dos fármacos
11.
Mater Sci Eng C Mater Biol Appl ; 62: 86-95, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26952401

RESUMO

In this study the comparative investigations of structural, surface and bactericidal properties of Ti-Ag and Nb-Ag thin films have been carried out. Ti-Ag and Nb-Ag coatings were deposited on silicon and fused silica substrates by magnetron co-sputtering method using innovative multi-target apparatus. The physicochemical properties of prepared thin films were examined with the aid of X-ray diffraction, grazing incidence X-ray diffraction, scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy methods. Moreover, the wettability of the surface was determined. It was found that both, Ti-Ag and Nb-Ag thin films were nanocrystalline. In the case of Ag-Ti film presence of AgTi3 and Ag phases was identified, while in the structure of Nb-Ag only silver occurred in a crystal form. In both cases the average size of crystallites was ca. 11 nm. Moreover, according to scanning electron microscopy and atomic force microscopy investigations the surface of Nb-Ag thin films was covered with Ag-agglomerates, while Ti-Ag surface was smooth and devoid of silver particles. Studies of biological activity of deposited coatings in contact with Bacillus subtilis, Pseudomonas aeruginosa, Enterococcus hirae, Klebisiella pneumoniae, Escherichia coli, Staphylococcus aureus and Candida albicans were performed. It was found that prepared coatings were bactericidal and fungicidal even in a short term-contact, i.e. after 2 h.


Assuntos
Anti-Infecciosos/química , Nióbio/química , Prata/química , Titânio/química , Anti-Infecciosos/farmacologia , Candida albicans/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Silício/química , Dióxido de Silício/química , Propriedades de Superfície , Difração de Raios X
12.
J Physiol Pharmacol ; 67(3): 385-93, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27511999

RESUMO

Warfarin dosage estimation using the pharmacogenetic algorithms has been shown to improve the quality of anticoagulation control in patients with atrial fibrillation. We sought to assess the genetic, demographic and clinical factors that determine the quality of anticoagulation in patients following aortic valve replacement (AVR). We studied 200 consecutive patients (130 men) aged 63 ± 12.3 years, undergoing AVR, in whom warfarin dose was established using a pharmacogenetic algorithm. The quality of anticoagulation within the first 3 months since surgery was expressed as the time of international normalized ratio (INR) in the therapeutic range (TTR). The median TTR in the entire cohort was 59.6% (interquartile range, 38.7 - 82.7). Ninety-nine (49.5%) patients with TTR ≥ 60% did not differ from those with poor anticoagulation control (TTR < 60%) with regard to demographic and cardiovascular risk factors. Coronary artery disease (n = 84, 42%) and previous stroke (n = 5, 2.5%) predicted higher TTR, while possession of CYP2C9*2 variant allele (n = 49, 25%) was associated with lower TTR (P = 0.01). In turn, VKORC1 c.-1639A, CYP2C9*2 and *3 variants were independently associated with actual warfarin dose (P < 0.0001). In AVR patients better anticoagulation control is observed in patients with coronary artery disease and history of stroke, which might result in part from previous lifestyle modification and therapy. Possession of CYP2C9*2 and/or CYP2C9*3 allele variants is associated with lower TTR values and warfarin dose variations in AVR patients, the latter affected also by VKORC1 c.-1693G>A polymorphism.


Assuntos
Anticoagulantes/administração & dosagem , Valva Aórtica , Citocromo P-450 CYP2C9/genética , Implante de Prótese de Valva Cardíaca , Vitamina K Epóxido Redutases/genética , Varfarina/administração & dosagem , Idoso , Algoritmos , Anticoagulantes/uso terapêutico , Coagulação Sanguínea/genética , Relação Dose-Resposta a Droga , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Varfarina/uso terapêutico
13.
Biochim Biophys Acta ; 1194(1): 1-11, 1994 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-8075122

RESUMO

The permeability of human spermatozoa to glycerol and its activation energy were determined using electron paramagnetic resonance (EPR) techniques. EPR was used to monitor the aqueous cell volume change vs. time during the glycerol permeation process using the aqueous spin label 15N-tempone and the membrane impermeable broadening agent potassium trioxalatochromiate (chromium oxalate). The permeation process was completed in tens of seconds, requiring the use of a stopped-flow methodology. The glycerol permeability coefficient (Pg) was determined by fitting a simple theoretical model to the experimental data. The permeabilities of human spermatozoa in 1 molar and 2 molar glycerol at 20 degrees C are (10.3 +/- 0.3).10(-4) cm/min (mean +/- S.D.) and (6.0 +/- 1.4).10(-4) cm/min, respectively. The permeabilities of human spermatozoa in 2 molar glycerol at 30, 20, 10, and 0 degrees C are (8.3 +/- 1.3).10(-4) cm/min, (6.0 +/- 1.4).10(-4) cm/min, (2.1 +/- 0.4).10(-4) cm/min, and (1.1 +/- 0.3).10(-4) cm/min, respectively. The activation energy (Ea) for glycerol permeation between 30 degrees C and 0 degrees C was found to be 11.6 kcal/mol.


Assuntos
Permeabilidade da Membrana Celular , Glicerol/metabolismo , Espermatozoides/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Eritrócitos/metabolismo , Glicerol/química , Humanos , Bicamadas Lipídicas/química , Masculino , Marcadores de Spin , Estatística como Assunto , Temperatura
14.
Biochim Biophys Acta ; 1480(1-2): 132-44, 2000 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-10899615

RESUMO

Protein geranylgeranyltransferase type I (GGTase I) is a heterodimeric zinc metalloenzyme catalyzing protein geranylgeranylation at cysteine residues present in C-terminal signature sequences referred to as CaaX (X=Leu) motifs. We have studied GGTase I as a potential antifungal target and recently reported its purification and cloning from the yeast Candida albicans (Ca GGTase I), an important human pathogen. Here, we report the high yield bacterial expression of Ca GGTase I by coexpression of maltose binding protein fusion proteins of both the alpha (Ram2p) and beta (Cdc43p) subunits. The cleaved and purified recombinant Ca GGTase I was demonstrated to be functional and structurally intact as judged by the presence of one equivalent of a tightly bound zinc atom and the near stoichiometric formation, isolation and catalytic turnover of a geranylgeranyl pyrophosphate-GGTase I complex. Kinetic analysis was performed with a native substrate protein, Candida Cdc42p, which exhibited significant pH dependent substrate inhibition, a feature not observed with other Ca GGTase I substrates. Prenyl acceptor substrate specificity was studied with a series of peptides in which both the CaaX motif, and the sequence preceding it, were varied. The prenyl acceptor K(M)s were found to vary nearly 100-fold, with biotinyl-TRERKKKKKCVIL, modeled after a presumably geranylgeranylated Candida protein, Crl1p (Rho4p), being the optimal substrate. A screen for inhibitors of Ca GGTase I identified compounds showing selectivity for the Candida versus human GGTase I. The most potent and selective compound, L-689230, had an IC(50) of 20 nM and >12,500-fold selectivity for Ca GGTase I. The lack of significant anti-Candida activity for any of these inhibitors is consistent with the recent finding that GGTase I is not required for C. albicans viability [R. Kelly et al., J. Bacteriol. 182 (2000) 704-713].


Assuntos
Alquil e Aril Transferases/metabolismo , Candida albicans/enzimologia , Inibidores Enzimáticos/farmacologia , Alquil e Aril Transferases/antagonistas & inibidores , Sequência de Aminoácidos , Sequência de Bases , Dados de Sequência Molecular , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
15.
Mater Sci Eng C Mater Biol Appl ; 47: 211-21, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25492191

RESUMO

In this paper comparative studies on the structural, mechanical and corrosion properties of Nb2O5/Ti and (NbyCu1-y)Ox/Ti alloy systems have been investigated. Pure layers of niobia and niobia with a copper addition were deposited on a Ti6Al4V titanium alloy surface using the magnetron sputtering method. The physicochemical properties of the prepared thin films were examined with the aid of XRD, XPS SEM and AFM measurements. The mechanical properties (i.e., nanohardness, Young's modulus and abrasion resistance) were performed using nanoindentation and a steel wool test. The corrosion properties of the coatings were determined by analysis of the voltammetric curves. The deposited coatings were crack free, exhibited good adherence to the substrate, no discontinuity of the thin film was observed and the surface morphology was homogeneous. The hardness of pure niobium pentoxide was ca. 8.64GPa. The obtained results showed that the addition of copper into pure niobia resulted in the preparation of a layer with a lower hardness of ca. 7.79 GPa (for niobia with 17 at.% Cu) and 7.75 GPa (for niobia with 25 at.% Cu). The corrosion properties of the tested thin films deposited on the surface of titanium alloy depended on the composition of the thin layer. The addition of copper (i.e. a noble metal) to Nb2O5 film increased the corrosion resistance followed by a significant decrease in the value of corrosion currents and, in case of the highest Cu content, the shift of corrosion potential towards the noble direction. The best corrosion properties were obtained from a sample of Ti6Al4V coated with (Nb0.75Cu0.25)Ox thin film. It seems that the tested materials could be used in the future as protection coatings for Ti alloys in biomedical applications such as implants.


Assuntos
Materiais Revestidos Biocompatíveis/química , Cobre/química , Nióbio/química , Óxidos/química , Titânio/química , Ligas , Corrosão , Implantes Dentários , Dureza , Teste de Materiais/métodos , Próteses e Implantes , Propriedades de Superfície
16.
Oncogene ; 34(5): 578-88, 2015 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-24509876

RESUMO

Lung cancer is the leading cause of cancer-related deaths worldwide. Recently, we have shown that Notch1 inhibition resulted in substantial cell death of non-small cell lung cancer (NSCLC) cells in vitro. New compounds targeting Notch signal transduction have been developed and are now being tested in clinical trials. However, the tumorigenic role of individual Notch receptors in vivo remains largely unclear. Using a Kras(G12D)-driven endogenous NSCLC mouse model, we analyzed the effect of conditional Notch1 and Notch2 receptor deletion on NSCLC tumorigenesis. Notch1 deficiency led to a reduced early tumor formation and lower activity of MAPK compared with the controls. Unexpectedly, Notch2 deletion resulted in a dramatically increased carcinogenesis and increased MAPK activity. These mice died significantly earlier due to rapidly growing tumor burden. We found that Notch1 regulates Ras/MAPK pathway via HES1-induced repression of the DUSP1 promoter encoding a phosphatase specifically suppressing pERK1/2. Interestingly, Notch1 but not Notch2 ablation leads to decreased HES1 and DUSP1 expression. However, Notch2-depleted tumors showed an appreciable increase in ß-catenin expression, a known activator of HES1 and important lung cancer oncogene. Characteristically for ß-catenin upregulation, we found that the majority of Notch2-deficient tumors revealed an undifferentiated phenotype as determined by their morphology, E-Cadherin and TTF1 expression levels. In addition, these carcinomas showed aggressive growth patterns with bronchus invasion and obstruction. Together, we show that Notch2 mediates differentiation and has tumor suppressor functions during lung carcinogenesis, whereas Notch1 promotes tumor initiation and progression. These data are further supported by immunohistochemical analysis of human NSCLC samples showing loss or downregulation of Notch2 compared with normal lung tissue. In conclusion, this is the first study characterizing the in vivo functions of Notch1 and Notch2 in Kras(G12D)-driven NSCLC tumorigenesis. These data highlight the clinical importance of a thorough understanding of Notch signaling especially with regard to Notch-targeted therapies.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Transformação Celular Neoplásica/genética , Receptor Notch1/biossíntese , Receptor Notch2/biossíntese , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/genética , Modelos Animais de Doenças , Fosfatase 1 de Especificidade Dupla/biossíntese , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/biossíntese , Humanos , Camundongos , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptor Notch1/genética , Receptor Notch2/genética , Transdução de Sinais/genética , Fatores de Transcrição HES-1 , beta Catenina/biossíntese
17.
Endocrinology ; 98(2): 403-12, 1976 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1248454

RESUMO

Labeled microspheres were used to measure blood flow to the leg bones of the laying hen at 0, 3, and 30 min after iv injection of parathyroid hormone (PTH) (Wilson) or the synthetic 1 to 34 fragment of bovine parathyroid hormone (PTH 1-34). At 3 min, which corresponds to the hypocalcemic phase of the PTH response, blood flow to the combined femur, tibia, and metatarus was significantly reduced by PTH (Wilson) relative to 0 time and to carrier-injected controls. At 30 min, i.e., the time of maximum hypercalcemia in the hen, blood flow to these bones was significantly increased relative to 0 time. The results obtained with PTH 1-34 were similar, except that the decrease at 3 min was only significant in comparison with the controls injected with inactivated hormone. Femoral blood flow and the venous minus arterial calcium gradients across the femur were positively correlated, irrespective of sampling time (0 or 30 min) or type of injection (PTH [Wilson] or carrier). Taken together, these results suggest that there is a relationship between calcium mobilization from bone and the rate of osseous blood flow. Other organs which showed significant changes in blood flow after PTH (Wilson) were the adrenals, thyroids, and shell gland; the cerebellum, parathyroids, heart, spleen, liver, pancreas, duodenum, magnum, isthmus, and kidneys were not affected.


Assuntos
Cálcio/sangue , Fêmur/irrigação sanguínea , Metatarso/irrigação sanguínea , Hormônio Paratireóideo/farmacologia , Tíbia/irrigação sanguínea , Glândulas Suprarrenais , Animais , Pressão Sanguínea/efeitos dos fármacos , Cálcio/metabolismo , Débito Cardíaco/efeitos dos fármacos , Galinhas , Glândulas Exócrinas/irrigação sanguínea , Feminino , Fêmur/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Hematócrito , Fosfatos/sangue , Fosfatos/metabolismo , Fluxo Sanguíneo Regional/efeitos dos fármacos
18.
Pediatrics ; 74(2): 198-205, 1984 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6611537

RESUMO

Twenty-four grade school children who had sustained an earlier episode of Haemophilus influenzae type b meningitis were tested, along with a group of 24 school-aged siblings. Evaluations consisted of tests of IQ, academic achievement, and neuropsychological skills. Parents completed forms rating each child's behavioral adjustment and temperament. Available school-administered standardized achievement tests were also obtained. Information relating to the episode of meningitis was extracted from the medical charts of each child who had had meningitis in order to investigate the relationship of these parameters to developmental outcome. Results showed that, compared with nearest-age siblings, children who had had meningitis scored lower on performance IQ and full-scale IQ. The group that had had meningitis also performed more poorly on several neuropsychological tasks. However, the groups did not differ in verbal IQ, and they performed comparably on all academic measures. Significant behavioral adjustment problems were absent from both groups, and there were no notable differences in temperament. Although findings support the existence of postmeningitis sequelae, the selective nature of the deficiencies observed indicate that prognosis for children in the age range examined may be better than that suggested by earlier studies.


Assuntos
Avaliação Educacional , Inteligência , Meningite por Haemophilus/psicologia , Convulsões/etiologia , Criança , Desenvolvimento Infantil , Pré-Escolar , Feminino , Haemophilus influenzae , Humanos , Lactente , Masculino , Meningite por Haemophilus/complicações , Pais , Prognóstico , Temperamento , Fatores de Tempo , Escalas de Wechsler
19.
Cell Biochem Biophys ; 31(3): 231-45, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10736749

RESUMO

The goals of the centrifugation of cell suspensions are to obtain the maximum yield of cells with minimum adverse effects of centrifugation. In the case of mechanically sensitive cells such as mouse sperm, the two goals are somewhat contradictory in that g-forces sufficient to achieve high yields are damaging, and g-forces that yield high viability produce low yields. This paper mathematically analyzes the factors contributing to each goal. The total yield of pelleted cells is determined by the sedimentation rate governed by Stokes' Law, and depends on the relative centrifugal force, centrifugation time, size and shape of the cells, density of the cells and medium, viscosity of the medium, and the length of the column of suspension. Because in the situation analyzed the column is short relative to the rotor radius, the analysis considers the centrifugal field to be quasi-homogeneous. The assumption is that cells are not damaged during sedimentation, but that they become injured at an exponential rate once they are pelleted, a rate that will depend on the specific cell type. The behavior is modeled by the solution of coupled differential equations. The predictions of the analysis are in good agreement with experimental data on the centrifugation of mouse sperm.


Assuntos
Separação Celular/métodos , Sobrevivência Celular , Espermatozoides/citologia , Animais , Centrifugação , Masculino , Matemática , Camundongos , Modelos Teóricos
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