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1.
Equine Vet J ; 50(1): 73-78, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28608565

RESUMO

REASON FOR PERFORMING STUDY: Headshaking in horses has been reported to be most commonly due to idiopathic neuropathic facial pain (trigeminal-mediated headshaking). The prevalence of headshaking in horses in the UK is unknown. OBJECTIVES: To estimate owner-reported prevalence of headshaking in horses in the UK and to report their case background and disease characteristics, as reported by owners. STUDY DESIGN: Cross-sectional web based owner questionnaire. METHODS: The questionnaire was advertised online via social media, horse forums, veterinary websites and equestrian magazines from 17th June 2016, until >1000 responses had been obtained. All UK horse owners were eligible to complete the questionnaire, however only one questionnaire could be completed per owner. RESULTS: The estimated prevalence of owner-reported headshaking in the sample population of horses (n = 1014), within the last year, was 4.6% (95% confidence interval 3.5-6.1), whereas 6.2% (95% confidence interval 4.9-7.9) of horses were reported by their owners to have shown signs of headshaking at any time-point since ownership. There was no association of sex or breed. Nineteen percent of headshaking horses were reported to show headshaking at rest. Fewer than one-third (30.2%, n = 19) of headshaking horses had been examined by a veterinarian for headshaking. Of horses seen by a veterinarian, the cause for headshaking remained unknown in the majority of cases (57.9% responses) and trigeminal-mediated headshaking was reported as a diagnosis in just one case. MAIN LIMITATIONS: The accuracy in data reporting by horse owners was not verified in this study. There may be a potential for bias towards over-reporting due to the nature of survey participation. CONCLUSIONS: Within this sample, owner-reported prevalence of signs of headshaking within the last year, in horses in the UK was 4.6%. Over two-thirds of owners of headshaking horses did not seek veterinary intervention for headshaking. Trigeminal-mediated headshaking was rarely reported by owners as a diagnosis.


Assuntos
Comportamento Animal , Doenças dos Cavalos/diagnóstico , Cavalos , Animais , Feminino , Humanos , Masculino , Inquéritos e Questionários , Reino Unido
2.
Obes Sci Pract ; 2(3): 248-255, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27708841

RESUMO

BACKGROUND: The purpose of this study was to examine weight loss, physical activity, fitness and diet changes in response to a standard behavioral weight loss intervention in adults with self-reported juvenile onset (n = 61) or adult onset (n = 116) obesity. METHODS: Participants (n = 177; 43.0 ± 8.6 years; body mass index [BMI] = 33.0 ± 3.4 kg m-2) engaged in an 18-month standard behavioral weight loss intervention. Participants were randomized into three different intervention groups as part of the larger parent trial. BMI, physical activity, fitness and diet were assessed at baseline, 6, 12 and 18 months. Separate adjusted mixed models were constructed using SAS version 9.4 (SAS Institute, Cary, NC). RESULTS: There was significant weight loss, increased physical activity, improved fitness and reduced caloric intake over time (p < 0.001). There were no significant differences in these outcome variables by obesity onset group. However, there was a significant group by time interaction for fitness (p = 0.001), with the adult onset making significantly greater gains in fitness from baseline to 6 months (p < 0.001); however, this difference was no longer present at 12 or 18 months. CONCLUSIONS: With the exception of fitness at 6 months, weight loss, physical activity and diet did not differ between juvenile onset and adult onset participants, suggesting that those with juvenile onset obesity are equally responsive to a standard behavioral weight loss intervention in adulthood.

3.
Equine Vet J ; 48(6): 676-680, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26706711

RESUMO

REASONS FOR PERFORMING STUDY: Antimicrobial stewardship within the veterinary profession is recognised by governing and professional bodies as being important; the attitudes and behaviour of veterinary surgeons merit investigation. OBJECTIVES: To investigate levels of protected antimicrobial use and accuracy of antimicrobial dosing in a common clinical scenario in equine practice. STUDY DESIGN: Retrospective cohort study. METHODS: Antimicrobial use was evaluated retrospectively in 113 cases subsequently referred to a single referral hospital for the treatment of limb wounds over a 20-month period. Antimicrobial classification (first-line, alternative or protected) was made according to guidelines produced by the British Equine Veterinary Association. These guidelines also served as the reference for recommended dose rates. RESULTS: Systemic antimicrobials were administered prior to referral in 94/113 (83.2%) horses, of which 8 (8.5%) received the protected third or fourth generation cephalosporins or fluoroquinolones. Forty-eight of 87 (55.2%) horses for which complete dosing data were available received antimicrobials at ≤90% of the recommended dose. Practitioners who held a postgraduate clinical qualification or worked in purely equine practice were no more or less likely to use protected antimicrobials (P = 0.06 and P = 0.64, respectively) or administer inadequate doses (P = 0.75 and P = 0.85, respectively). Veterinary surgeons with more experience were less likely to use protected antimicrobials (P<0.001); however, with the small case numbers, this finding should be interpreted with caution. Heavier horses were more likely to be under-dosed (P<0.002). CONCLUSIONS: This study highlights the administration of certain classes of antimicrobials in situations where their use is unlikely to be justified. If these findings reflect more general attitudes and behaviour then greater awareness of, and compliance with, recommendations for responsible antimicrobial use are required among equine practitioners. Bodyweight ought to be measured or estimated using validated objective techniques prior to systemic medications being administered.


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/veterinária , Doenças dos Cavalos/prevenção & controle , Cavalos/lesões , Ferimentos e Lesões/veterinária , Animais , Antibacterianos/administração & dosagem , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/prevenção & controle , Estudos de Coortes , Relação Dose-Resposta a Droga , Esquema de Medicação , Doenças dos Cavalos/epidemiologia , Estudos Retrospectivos , Reino Unido/epidemiologia , Ferimentos e Lesões/complicações , Ferimentos e Lesões/epidemiologia
4.
Obes Rev ; 14(8): 645-58, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23601571

RESUMO

The purpose of this review was to examine the factors that predict the development of excessive fatness in children and adolescents. Medline, Web of Science and PubMed were searched to identify prospective cohort studies that evaluated the association between several variables (e.g. physical activity, sedentary behaviour, dietary intake and genetic, physiological, social cognitive, family and peer, school and community factors) and the development of excessive fatness in children and adolescents (5-18 years). Sixty-one studies met the eligibility criteria and were included. There is evidence to support the association between genetic factors and low physical activity with excessive fatness in children and adolescents. Current studies yielded mixed evidence for the contribution of sedentary behaviour, dietary intake, physiological biomarkers, family factors and the community physical activity environment. No conclusions could be drawn about social cognitive factors, peer factors, school nutrition and physical activity environments, and the community nutrition environment. There is a dearth of longitudinal evidence that examines specific factors contributing to the development of excessive fatness in childhood and adolescence. Given that childhood obesity is a worldwide public health concern, the field can benefit from large-scale, long-term prospective studies that use state-of-the-art measures in a diverse sample of children and adolescents.


Assuntos
Adiposidade/fisiologia , Dieta , Estilo de Vida , Obesidade/epidemiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Obesidade/etiologia , Fatores de Risco , Meio Social
5.
Health Place ; 18(5): 951-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22809713

RESUMO

After-school hours are considered critical for children's physical activity (PA) and sedentary behaviors (SB); however, whether the after-school setting influences children's activity patterns is unknown. This study examined the influence of after-school setting (i.e., parent report of the child's usual after-school setting) on 5th grade children's PA and SB, and differences by race/ethnicity. Boys whose parents reported they usually attended an after-school program had higher PA than boys who usually went home after school. A significant interaction between race/ethnicity and after-school setting showed that minority girls whose parents reported they usually attended an after-school program had higher PA and engaged in less SB compared with those who usually went home, whereas the activity patterns of white girls did not differ by after-school setting. Children's usual after-school setting affects their activity patterns; after-school programs may potentially increase PA in boys and minority girls.


Assuntos
Atividades de Lazer , Atividade Motora , Comportamento Sedentário , Criança , Feminino , Humanos , Masculino , South Carolina
6.
Appl Clin Inform ; 1(1): 1-10, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-23616824

RESUMO

OBJECTIVE: Assess the interest in and preferences of ambulatory practitioners in HIE. BACKGROUND: Health information exchange (HIE) may improve the quality and efficiency of care. Identifying the value proposition for smaller ambulatory practices may help those practices engage in HIE. METHODS: Survey of primary care and specialist practitioners in the State of Colorado. RESULTS: Clinical data were commonly (always [2%], often [29%] or sometimes [49%]) missing during clinic visits. Of 12 data types proposed as available through HIE, ten were considered "extremely useful" by most practitioners. "Clinical notes/consultation reports," "diagnosis or problem lists," and "hospital discharge summaries" were considered the three most useful data types. Interest in EKG reports, diagnosis/problem lists, childhood immunizations, and discharge summaries differed among ambulatory practitioner groups (primary care, obstetrics-gynecology, and internal medicine subspecialties). CONCLUSION: Practitioners express strong interest in most of the data types, but opinions differed by specialties on what types were most important. All providers felt that a system that provided all data types would be useful. These results support the potential benefit of HIE in ambulatory practices.

7.
J Trauma ; 51(6): 1054-61, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11740250

RESUMO

BACKGROUND: Construction of gastrointestinal anastomoses utilizing stapling devices has become a familiar procedure. In elective surgery, studies have shown no significant differences in complications between stapled and sutured anastomoses. Controversy has recently arisen regarding the accurate incidence of complications associated with anastomoses in the trauma patient. The objective of this multi-institutional study was to determine whether the incidence of postoperative complications differs between stapled and sutured anastomoses following the emergent repair of traumatic bowel injuries. METHODS: Using a retrospective cohort design, all trauma registry records from five Level I trauma centers over a period of 4 years were reviewed. RESULTS: A total of 199 patients with 289 anastomoses were identified. A surgical stapling device was used to create 175 separate anastomoses, while a hand-sutured method was employed in 114 anastomoses. A complication was defined as an anastomotic leak verified at reoperation, an intra-abdominal abscess, or an enterocutaneous fistula. The mean abdominal Abbreviated Injury Scale score and Injury Severity Score were similar in the two cohort groups. Stapling and suturing techniques were evenly distributed in both small and large bowel repairs. Seven of the total 175 stapled anastomoses and none of the 114 hand-sewn anastomoses resulted in a clinically significant leak requiring reoperation (RR = undefined, 95% CI 1.08-infinity, p = 0.04). Each anastomotic leak occurred in a separate individual. Nineteen stapled anastomoses and four sutured anastomoses were associated with an intra-abdominal abscess (RR = 2.7, 95% CI 0.96-7.57, p = 0.04). Enterocutaneous fistula formation was not statistically associated with either type of anastomoses (stapled cohort = 3 of 175 and sutured cohort = 2 of 114). Overall, 22 (13%) stapled anastomoses and 6 (5%) sutured anastomoses were associated with an intra-abdominal complication (RR = 2.08, 95% CI 0.89-4.86, p = 0.076). CONCLUSION: Anastomotic leaks and intra-abdominal abscesses appear to be more likely with stapled bowel repairs compared with sutured anastomoses in the injured patient. Caution should be exercised in deciding to staple a bowel anastomosis in the trauma patient.


Assuntos
Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/instrumentação , Procedimentos Cirúrgicos do Sistema Digestório , Sistema Digestório/lesões , Complicações Pós-Operatórias/epidemiologia , Adolescente , Adulto , Idoso , Anastomose Cirúrgica/métodos , California , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Incidência , Escala de Gravidade do Ferimento , Masculino , Prontuários Médicos , Pessoa de Meia-Idade , New Jersey , North Carolina , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Suturas , Estados Unidos/epidemiologia , Virginia , Washington
8.
J Biol Chem ; 276(19): 16348-55, 2001 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-11340085

RESUMO

Despite the knowledge that CCAAT/enhancer-binding protein alpha (C/EBPalpha) plays an important role in preadipocyte differentiation, our understanding of how C/EBPalpha interacts with nuclear proteins to regulate transcription is limited. Based on the hypothesis that evolutionarily conserved regions are functionally important and likely to interact with coactivators, we compared the amino acid sequence of C/EBPalpha from different species (frog to human) and identified four highly conserved regions (CR1-CR4) within the transactivation domain. A series of amino-terminal truncations and internal deletion constructs were made creating forms of C/EBPalpha which lack single or multiple conserved regions. To determine which regions of the C/EBPalpha transactivation domain are important in its ability to induce spontaneous differentiation of 3T3-L1 preadipocytes, we infected preadipocytes with expression vectors encoding the C/EBPalpha conserved region mutants and observed their ability to induce differentiation. We found that CR2 fused to the DNA binding domain is able to induce spontaneous differentiation independent of the other conserved regions. However, CR2 was not necessary for the adipogenic action of C/EBPalpha because a combination of CR1 and CR3 can also induce adipogenesis. Because the transcriptional coactivator p300 participates in the signaling of many transcription factors to the basal transcriptional apparatus, we examined whether functional interaction exists between C/EBPalpha and p300. Cotransfection of p300 with p42C/EBPalpha results in a synergistic increase in leptin promoter activity, indicating that p300 acts as a transcriptional coactivator of C/EBPalpha. Analyses using C/EBPalpha conserved region mutants suggest that multiple regions (CR2 and CR3) of the C/EBPalpha transactivation domain functionally interact with p300.


Assuntos
Adipócitos/metabolismo , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Células 3T3 , Adipócitos/citologia , Animais , Sequência de Bases , Proteína alfa Estimuladora de Ligação a CCAAT/química , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Linhagem Celular , Clonagem Molecular , Primers do DNA , Proteína p300 Associada a E1A , Genes Reporter , Vetores Genéticos , Humanos , Luciferases/genética , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Retroviridae , Ativação Transcricional , Transfecção
9.
J Biol Chem ; 276(22): 19664-71, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11278638

RESUMO

Growth hormone (GH) regulates transcription factors associated with c-fos, including C/EBPbeta. Two forms of C/EBPbeta, liver-activating protein (LAP) and liver inhibitory protein (LIP), are dephosphorylated in GH-treated 3T3-F442A fibroblasts. GH-induced dephosphorylation of LAP and LIP is reduced when cells are preincubated with phosphatidylinositol 3'-kinase (PI3K) inhibitors. GH activates Akt and inhibits glycogen synthase kinase-3 (GSK-3). Lithium, a GSK-3 inhibitor, increases GH-dependent dephosphorylation of LAP and LIP. Both are in vitro substrates of GSK-3, suggesting that GSK-3 inactivation contributes to GH-promoted dephosphorylation of C/EBPbeta. Alkaline phosphatase increases binding of LAP homodimers and decreases binding of LIP homodimers to c-fos, suggesting that dephosphorylation of C/EBPbeta modifies their ability to bind DNA. Both alkaline phosphatase- and GH-mediated dephosphorylation comparably increase binding of endogenous LAP in 3T3-F442A cells. In cells overexpressing LAP and GSK-3, LAP binding decreases, suggesting that GSK-3-mediated phosphorylation interferes with LAP binding. Expression of constitutively active GSK-3 reduced GH-stimulated c-fos promoter activity. These studies indicate that PI3K/Akt/GSK-3 mediates signaling between GH receptor and the nucleus, promoting dephosphorylation of C/EBPbeta. Dephosphorylation increases binding of LAP complexes to the c-fos promoter and may contribute to the participation of C/EBPbeta in GH-stimulated c-fos expression.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Proteína beta Intensificadora de Ligação a CCAAT/fisiologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/metabolismo , Células 3T3 , Fosfatase Alcalina/metabolismo , Animais , Células CHO , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Linhagem Celular , Núcleo Celular/metabolismo , Cricetinae , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Quinase 3 da Glicogênio Sintase , Quinases da Glicogênio Sintase , Humanos , Immunoblotting , Lítio/farmacologia , Camundongos , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Plasmídeos/metabolismo , Testes de Precipitina , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas c-fos/metabolismo , Transdução de Sinais , Fatores de Tempo , Ativação Transcricional , Transfecção
10.
Am J Surg ; 180(3): 228-33, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11084136

RESUMO

BACKGROUND: Plasma viral load has recently been associated with clinical outcome in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). We hypothetized that, in addition to CD4 lymphocytes, plasma HIV-1 RNA counts are predictive of postoperative outcome. METHODS: HIV-infected and AIDS patients admitted to a major teaching hospital requiring invasive or surgical procedures were retrospectively analyzed for postoperative outcome. Preoperative and postoperative immune cell counts including plasma HIV-1 RNA counts were recorded. Chi-square analysis, Fisher's exact test, and multivariate regression were performed with statistical significance P

Assuntos
Infecções por HIV/complicações , HIV-1/isolamento & purificação , Complicações Pós-Operatórias/diagnóstico , RNA Viral/sangue , Procedimentos Cirúrgicos Operatórios , Carga Viral/normas , Síndrome da Imunodeficiência Adquirida/complicações , Adolescente , Adulto , Feminino , HIV-1/genética , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos
12.
Science ; 289(5481): 950-3, 2000 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-10937998

RESUMO

Wnts are secreted signaling proteins that regulate developmental processes. Here we show that Wnt signaling, likely mediated by Wnt-10b, is a molecular switch that governs adipogenesis. Wnt signaling maintains preadipocytes in an undifferentiated state through inhibition of the adipogenic transcription factors CCAAT/enhancer binding protein alpha (C/EBPalpha) and peroxisome proliferator- activated receptor gamma (PPARgamma). When Wnt signaling in preadipocytes is prevented by overexpression of Axin or dominant-negative TCF4, these cells differentiate into adipocytes. Disruption of Wnt signaling also causes transdifferentiation of myoblasts into adipocytes in vitro, highlighting the importance of this pathway not only in adipocyte differentiation but also in mesodermal cell fate determination.


Assuntos
Adipócitos/citologia , Adipócitos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras , Transdução de Sinais , Transativadores , Proteínas de Peixe-Zebra , Células 3T3 , Animais , Proteína Axina , Proteínas Estimuladoras de Ligação a CCAAT , Diferenciação Celular , Linhagem da Célula , Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Técnicas de Transferência de Genes , Vetores Genéticos , Mesoderma/citologia , Camundongos , Camundongos Nus , Músculos/citologia , Músculos/metabolismo , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas/genética , Proteínas/metabolismo , Proteínas Proto-Oncogênicas/genética , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Retroviridae/genética , Retroviridae/fisiologia , Fatores de Transcrição TCF , Proteína 2 Semelhante ao Fator 7 de Transcrição , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Wnt , beta Catenina
13.
Anal Chem ; 72(22): 5549-55, 2000 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11101230

RESUMO

Incorporation of planar waveguide technology into a spectroelectrochemical sensor is described. In this sensor design, a potassium ion-exchanged BK7 glass waveguide was over-coated with a thin film of indium tin oxide (ITO) that served as an optically transparent electrode. A chemically selective film was spin-coated on top of the ITO film. The sensor supported five optical modes at 442 nm and three at 633 nm. Investigations on the impact of the ITO film on the optical properties of the waveguide and on the spectroelectrochemical performance of the sensor are reported. Sensing was based on the change in attenuation of light propagated through the waveguide resulting from an optically absorbing analyte. By applying either a triangular or square wave excitation potential waveform, electromodulation of the optical signal has been demonstrated with Fe(CN)6(3-/4-) as a model electroactive couple that partitions into a PDMDAAC-SiO2 film [where PDMDAAC = poly(dimethyldiallylammonium chloride)] and absorbs at 442 nm.

15.
JPEN J Parenter Enteral Nutr ; 23(6): 356-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10574485

RESUMO

BACKGROUND: Anesthetic standard of care is to restrict oral intake for 8 hours before elective surgery. There is no research addressing appropriate preoperative discontinuation of jejunostomy tube (J-tube) feedings. We hypothesized that patients could be fed safely, via a J-tube, until the time of surgery. METHODS: Patients admitted to a Level I Trauma Center, having J-tubes and undergoing a nonabdominal operation, were prospectively evaluated. Group I patients received J-tube feedings until transport to the operating room. Group II patients had tube feedings discontinued for at least 8 hours before surgery. Data were compared using the Student's t test and contingency table analysis. RESULTS: There were 46 patients in group I and 36 in group II. There was no incidence of aspiration. Patient groups did not differ in age, mortality, length of stay, injury severity score, or ventilator days. Group I patients had tube feedings discontinued for fewer hours before and after surgery than group II patients (before surgery: 1.40 +/- 1.20 vs 11.61 +/- 5.01, respectively; p < .001; after surgery: 2.99 +/- 7.49 vs 7.11 +/- 9.03, respectively; p = .043); received more kilocalories/ grams of protein on the day of surgery (group I vs group II, 1676.15/89.57 +/- 1133.21/38.04 vs 791.14/57.58 +/-498.66/79.87, respectively; p = .001/p = .032) and more kilocalories/grams of protein on the first postoperative day (group I vs group II, 1580.74/92.57 +/- 600.53/37.96 vs 1152.47/63.53 +/- 733.96/39.40, respectively; p = .006/p = .001). CONCLUSIONS: Patients receiving J-tubes who are undergoing nonabdominal operations may safely continue enteral nutrition at maximum protein and caloric intake until surgery.


Assuntos
Nutrição Enteral , Jejunostomia , Adulto , Idoso , Humanos , Tempo de Internação , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos
16.
Mol Cell Biol ; 19(12): 8433-41, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10567568

RESUMO

CCAAT/enhancer binding protein alpha (C/EBPalpha) is a transcription factor involved in creating and maintaining the adipocyte phenotype. We have shown previously that insulin stimulates dephosphorylation of C/EBPalpha in 3T3-L1 adipocytes. Studies to identify the insulin-sensitive sites of phosphorylation reveal that a C/EBPalpha peptide (amino acids H215 to K250) is phosphorylated on T222, T226, and S230 in vivo. The context of these phosphoamino acids implicates glycogen synthase kinase 3 (GSK3), whose activity is known to be repressed in response to insulin, as a potential kinase for phosphorylation of T222 and T226. Accordingly, GSK3 phosphorylates the predicted region of C/EBPalpha on threonine in vitro, and GSK3 uses C/EBPalpha as a substrate in vivo. In addition, the effect of pharmacological agents on GSK3 activity correlates with regulation of C/EBPalpha phosphorylation. Treatment of 3T3-L1 adipocytes with the phosphatidylinositol 3-kinase inhibitor wortmannin results in phosphorylation of C/EBPalpha, whereas treatment with the GSK3 inhibitor lithium results in dephosphorylation of C/EBPalpha. Collectively, these data indicate that insulin stimulates dephosphorylation of C/EBPalpha on T222 and T226 through inactivation of GSK3. Since dephosphorylation of C/EBPalpha in response to lithium is blocked by okadaic acid, strong candidates for the T222 and T226 phosphatase are protein phosphatases 1 and 2a. Treatment of adipocytes with insulin alters the protease accessibility of widespread sites within the N terminus of C/EBPalpha, consistent with phosphorylation causing profound conformational changes. Finally, phosphorylation of C/EBPalpha and other substrates by GSK3 may be required for adipogenesis, since treatment of differentiating preadipocytes with lithium inhibits their conversion to adipocytes.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Insulina/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Células 3T3 , Androstadienos/metabolismo , Androstadienos/farmacologia , Animais , Proteínas Estimuladoras de Ligação a CCAAT , Diferenciação Celular , Linhagem Celular Transformada , Proteínas de Ligação a DNA/genética , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Quinase 3 da Glicogênio Sintase , Quinases da Glicogênio Sintase , Humanos , Insulina/farmacologia , Antagonistas da Insulina/metabolismo , Antagonistas da Insulina/farmacologia , Lítio/metabolismo , Lítio/farmacologia , Camundongos , Proteínas Nucleares/genética , Fosfoaminoácidos , Fosforilação , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/genética , Wortmanina
17.
J Biol Chem ; 274(44): 31597-604, 1999 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-10531366

RESUMO

Using the c-fos enhancer as a model to analyze growth hormone (GH)-promoted gene expression, the roles of CCAAT/enhancer-binding proteins (C/EBPs) in GH-regulated transcription were investigated. In 3T3-F442A fibroblasts stably expressing the c-fos promoter mutated at the C/EBP binding site upstream of luciferase, c-fos promoter activity is stimulated by GH 6-7-fold; wild type c-fos promoter shows only a 2-fold induction by GH. This suggests that C/EBP restrains GH-stimulated expression of c-fos. Electrophoretic mobility shift assays with nuclear extracts from 3T3-F442A cells indicate that GH rapidly (2-5 min) increases binding of C/EBPbeta and C/EBPdelta, to the c-fos C/EBP binding site. Both liver activating protein (LAP) and liver inhibitory protein (LIP), forms of C/EBPbeta, are detected in 3T3-F442A cells by immunoblotting. GH increases the binding of LAP/LAP and LAP/LIP dimers. Overexpression of LIP interferes with GH-promoted reporter expression in CHO cells expressing GH receptors, consistent with the possibility that LIP restrains GH-stimulated c-fos expression. Overexpression of LAP elevates basal luciferase activity but does not influence promoter activation by GH, while overexpressed C/EBPdelta elevates basal promoter activity and enhances the stimulation by GH. GH stimulates the expression of mRNA for C/EBPbeta and -delta and increases levels of C/EBPdelta. Although C/EBPbeta is not detectably altered, GH induces a shift to more rapidly migrating forms of LIP and LAP upon immunoblotting. Treatment of extracts from GH-treated cells with alkaline phosphatase causes a shift of the slower migrating form to the rapidly migrating form, consistent with GH promoting dephosphorylation of LIP and LAP. These studies implicate C/EBPbeta and -delta in GH-regulated gene expression. They also indicate that GH stimulates the binding of C/EBPbeta and -delta to the c-fos promoter and promotes the dephosphorylation of LIP and LAP. These events may contribute to the ability of C/EBPbeta and -delta to regulate GH-stimulated expression of c-fos.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Hormônio do Crescimento/farmacologia , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas c-fos/genética , Células 3T3 , Animais , Proteínas Estimuladoras de Ligação a CCAAT , Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Camundongos , Mutação , Proteínas Nucleares/genética , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas c-fos/biossíntese , RNA Mensageiro/metabolismo , Elementos de Resposta , Fator de Resposta Sérica , Transcrição Gênica
18.
Arch Biochem Biophys ; 367(2): 193-201, 1999 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10395735

RESUMO

A series of alpha-ketooxadiazole compounds was prepared and evaluated in vitro as potential inhibitors of human neutrophil elastase (HNE), proteinase-3 (PR-3), and porcine pancreatic elastase (PPE). Several compounds have been found to be very potent, fast, reversible, and selective inhibitors of HNE with Ki values below 100 pM. The highest kon value exceeded 10(7) M(-1) s(-1). Some alpha-ketooxadiazoles were also very effective against PR-3 and PPE with Ki values in the range of 5(-10) nM and 0.1(-2) nM, respectively. The two rings, 1,2,4- and 1,3,4-oxadiazole, are amenable to substitutions, extending the P' side of the inhibitor and allowing additional binding interactions at S' subsites of the enzyme. Nonpeptidic HNE inhibitors containing the oxadiazole heterocycle displayed promising oral bioavailability.


Assuntos
Endopeptidases , Elastase de Leucócito/antagonistas & inibidores , Oxidiazóis/química , Oxidiazóis/farmacocinética , Catepsina G , Catepsina L , Catepsinas/metabolismo , Quimotripsina/metabolismo , Cisteína Endopeptidases , Humanos , Cinética , Oxidiazóis/síntese química , Pâncreas/enzimologia , Serina Endopeptidases
19.
J Trauma ; 46(3): 424-7, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10088844

RESUMO

BACKGROUND: Products of the hemeoxygenase enzyme include carboxyhemoglobin (COH) and bilirubin, which have protective effects in stressed states. Hemeoxygenase-1 enzyme up-regulates in states of oxidative stress. We hypothesized that COH is elevated in septic trauma patients compared with nonseptic patients. METHODS: A prospective study was carried out at a Level I trauma center involving all patients admitted to the trauma intensive care unit. During a 3.5-month period, 45 patients were enrolled, with 76 samples being drawn on admission and at later time points. The samples were classified as septic (Bone's criteria), stressed (based on expired gas analysis), or nonstressed nonseptic. Correlations with Acute Physiology and Chronic Health Evaluation III score, white blood cell count, temperature, partial pressure of oxygen, and percentage of inspired oxygen were evaluated. RESULTS: COH levels in samples drawn from patients presenting in shock (systolic blood pressure < or =90 mm Hg) were significantly higher than levels in samples from patients not in shock (systolic blood pressure >90 mm Hg) (3.27+/-1.09 vs. 2.75+/-0.64; p = 0.013). Samples from septic patients with infection were associated with significantly higher Injury Severity Scores (34.1+/-11.2 vs. 21.8+/-18.3; p< or =0.05) and a lower percentage of inspired oxygen (41.6+/-10.3 vs. 61.0+/-26.3; p< or =0.05). CONCLUSION: COH was significantly elevated in samples drawn during stress, sepsis, and shock states. There was overlap between sepsis and stress COH sample values, limiting the clinical usefulness of the assays in predicting sepsis. Further studies focusing on hemeoxygenase-1 expression and the role of its by-products in the outcomes of trauma patients are warranted.


Assuntos
Carboxihemoglobina/metabolismo , Traumatismo Múltiplo/complicações , Traumatismo Múltiplo/metabolismo , Estresse Oxidativo/fisiologia , Sepse/etiologia , APACHE , Adulto , Gasometria , Heme Oxigenase (Desciclizante)/fisiologia , Heme Oxigenase-1 , Humanos , Escala de Gravidade do Ferimento , Contagem de Leucócitos , Proteínas de Membrana , Traumatismo Múltiplo/imunologia , Traumatismo Múltiplo/mortalidade , Estudos Prospectivos , Sepse/classificação , Análise de Sobrevida
20.
Am Surg ; 65(2): 168-72, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9926753

RESUMO

We set out to determine whether the increases in intracranial pressure (ICP) associated with CO2 insufflation had any metabolic effect on the central nervous system in a head injury when compared with gasless laparoscopy (GL). To test this hypothesis, we looked at both the ICP and jugular bulb venous saturation (JVS), with and without a coexisting cerebral mass lesion. Twenty-five kilogram male pigs had tracheostomy, epidural balloon, pulmonary arterial catheter, arterial line, and jugular bulb catheter placed. Intravenous Pentobarbital was used for anesthesia. Either CO2 laparoscopy (CL; n=7) or GL (n=7) were performed both with and without an epidural balloon inflated to a baseline ICP of 25. Data were analyzed using the Student's t test with a P value <0.05 being significant. Cerebral perfusion pressure and most hemodynamic values did not differ. Both central venous pressure and peak inspiratory pressure were significantly elevated whenever CO2 insufflation took place, reflecting an increased intrathoracic pressure. When comparing both study groups, the partial pressure of CO2 did not differ. CL increases ICP significantly above the gasless group in our head injury model. This is most likely secondary to increased intrathoracic pressure. The question still remains whether these changes are clinically significant. We could not demonstrate significant metabolic effects secondary to laparoscopy. In patients suffering head injury, GL rather than CL might be safer to avoid ICP elevation. Additional studies looking at central nervous system metabolic and objective histopathologic effects should be undertaken with larger numbers of study animals.


Assuntos
Traumatismos Craniocerebrais/fisiopatologia , Pressão Intracraniana , Laparoscopia , Oxigênio/sangue , Animais , Encéfalo/irrigação sanguínea , Hemodinâmica , Humanos , Masculino , Pneumoperitônio Artificial , Fluxo Sanguíneo Regional , Suínos
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