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1.
Indian J Community Med ; 49(3): 529-531, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38933786

RESUMO

Background: Cervical cancer is a public health problem, and nursing personnel are crucial for successful implementation of low-cost cervical cancer screening approaches in low-resource settings. The following study assessed and compared the knowledge, attitude, and practices regarding cervical cancer and its screening among female nursing staff at different levels of health care facilities in western Rajasthan, India. Methodology: An anonymous pre-validated, structured questionnaire was used as the study tool among 233 female nursing personnel of primary, secondary, and tertiary care health facilities. Multiple logistic regression was performed to determine the association between level of knowledge with level of health care and other demographic variables. Results: The nursing staff of the tertiary care health facility demonstrated significantly higher knowledge compared to those working at primary and secondary levels [adjusted odds ratio (95% confidence interval) 11.01 (3.80-32.40)]. At tertiary care, the practices of the nursing professionals were not found significantly associated with any socio-demographic variable including age, marital status, or level of health care facility. Conclusion: The overall knowledge of cervical cancer was poor, especially among staff nurses at primary and secondary levels of health care. In order to implement a successful population-based screening program in India, it is important to update the nursing curriculum and start in-service trainings at primary and secondary levels of health care facilities.

2.
Cancer Res ; 83(20): 3478-3491, 2023 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-37526524

RESUMO

Understanding the rewired metabolism underlying organ-specific metastasis in breast cancer could help identify strategies to improve the treatment and prevention of metastatic disease. Here, we used a systems biology approach to compare metabolic fluxes used by parental breast cancer cells and their brain- and lung-homing derivatives. Divergent lineages had distinct, heritable metabolic fluxes. Lung-homing cells maintained high glycolytic flux despite low levels of glycolytic intermediates, constitutively activating a pathway sink into lactate. This strong Warburg effect was associated with a high ratio of lactate dehydrogenase (LDH) to pyruvate dehydrogenase (PDH) expression, which correlated with lung metastasis in patients with breast cancer. Although feature classification models trained on clinical characteristics alone were unable to predict tropism, the LDH/PDH ratio was a significant predictor of metastasis to the lung but not to other organs, independent of other transcriptomic signatures. High lactate efflux was also a trait in lung-homing metastatic pancreatic cancer cells, suggesting that lactate production may be a convergent phenotype in lung metastasis. Together, these analyses highlight the essential role that metabolism plays in organ-specific cancer metastasis and identify a putative biomarker for predicting lung metastasis in patients with breast cancer. SIGNIFICANCE: Lung-homing metastatic breast cancer cells express an elevated ratio of lactate dehydrogenase to pyruvate dehydrogenase, indicating that ratios of specific metabolic gene transcripts have potential as metabolic biomarkers for predicting organ-specific metastasis.


Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , Segunda Neoplasia Primária , Humanos , Feminino , Neoplasias da Mama/patologia , L-Lactato Desidrogenase/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Biomarcadores , Pulmão/patologia , Lactatos , Piruvatos , Melanoma Maligno Cutâneo
3.
Mol Cancer Res ; 20(8): 1193-1207, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35412614

RESUMO

Subunits of SWI/SNF chromatin remodeling complexes are frequently mutated in human malignancies. The PBAF complex is composed of multiple subunits, including the tumor-suppressor protein PBRM1 (BAF180), as well as ARID2 (BAF200), that are unique to this SWI/SNF complex. PBRM1 is mutated in various cancers, with a high mutation frequency in clear cell renal cell carcinoma (ccRCC). Here, we integrate RNA-seq, histone modification ChIP-seq, and ATAC-seq data to show that loss of PBRM1 results in de novo gains in H3K4me3 peaks throughout the epigenome, including activation of a retinoic acid biosynthesis and signaling gene signature. We show that one such target gene, ALDH1A1, which regulates a key step in retinoic acid biosynthesis, is consistently upregulated with PBRM1 loss in ccRCC cell lines and primary tumors, as well as non-malignant cells. We further find that ALDH1A1 increases the tumorigenic potential of ccRCC cells. Using biochemical methods, we show that ARID2 remains bound to other PBAF subunits after loss of PBRM1 and is essential for increased ALDH1A1 after loss of PBRM1, whereas other core SWI/SNF components are dispensable, including the ATPase subunit BRG1. In total, this study uses global epigenomic approaches to uncover novel mechanisms of PBRM1 tumor suppression in ccRCC. IMPLICATIONS: This study implicates the SWI/SNF subunit and tumor-suppressor PBRM1 in the regulation of promoter histone modifications and retinoic acid biosynthesis and signaling pathways in ccRCC and functionally validates one such target gene, the aldehyde dehydrogenase ALDH1A1.


Assuntos
Família Aldeído Desidrogenase 1 , Carcinoma de Células Renais , Proteínas de Ligação a DNA , Código das Histonas , Neoplasias Renais , Fatores de Transcrição , Família Aldeído Desidrogenase 1/genética , Carcinoma de Células Renais/patologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Neoplasias Renais/patologia , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Retinal Desidrogenase/genética , Retinal Desidrogenase/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tretinoína/farmacologia
4.
Mol Cancer Ther ; 21(5): 831-843, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-35247928

RESUMO

Therapeutic resistance is a fundamental obstacle in cancer treatment. Tumors that initially respond to treatment may have a preexisting resistant subclone or acquire resistance during treatment, making relapse theoretically inevitable. Here, we investigate treatment strategies that may delay relapse using mathematical modeling. We find that for a single-drug therapy, pulse treatment-short, elevated doses followed by a complete break from treatment-delays relapse compared with continuous treatment with the same total dose over a length of time. For tumors treated with more than one drug, continuous combination treatment is only sometimes better than sequential treatment, while pulsed combination treatment or simply alternating between the two therapies at defined intervals delays relapse the longest. These results are independent of the fitness cost or benefit of resistance, and are robust to noise. Machine-learning analysis of simulations shows that the initial tumor response and heterogeneity at the start of treatment suffice to determine the benefit of pulsed or alternating treatment strategies over continuous treatment. Analysis of eight tumor burden trajectories of breast cancer patients treated at Memorial Sloan Kettering Cancer Center shows the model can predict time to resistance using initial responses to treatment and estimated preexisting resistant populations. The model calculated that pulse treatment would delay relapse in all eight cases. Overall, our results support that pulsed treatments optimized by mathematical models could delay therapeutic resistance.


Assuntos
Neoplasias da Mama , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Recidiva , Carga Tumoral
5.
Trends Cancer ; 8(6): 506-516, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35277375

RESUMO

For decades, mathematical models have influenced how we schedule chemotherapeutics. More recently, mathematical models have leveraged lessons from ecology, evolution, and game theory to advance predictions of optimal treatment schedules, often in a personalized medicine manner. We discuss both established and emerging therapeutic strategies that deviate from canonical standard-of-care regimens, and how mathematical models have contributed to the design of such schedules. We first examine scheduling options for single therapies and review the advantages and disadvantages of various treatment plans. We then consider the challenge of scheduling multiple therapies, and review the mathematical and clinical support for various conflicting treatment schedules. Finally, we propose how a consilience of mathematical and clinical knowledge can best determine the optimal treatment schedules for patients.


Assuntos
Neoplasias , Humanos , Modelos Teóricos , Neoplasias/tratamento farmacológico , Medicina de Precisão
6.
Curr Opin Microbiol ; 63: 150-157, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34352595

RESUMO

The gut microbiome is an ecosystem. Natural selection favored microbes fit for the gut, which can utilize and convert molecules produced by the host for their own benefit. But natural selection also favored the host's mechanisms to sense and respond to the microbial ecosystem for its own benefit. We can listen in on the host-microbiome 'conversation' in the simultaneous responses of the microbiome and the host to strong perturbations. In laboratory animals a perturbation can be done for research; in human patients a perturbation can be caused by disease or therapy. Advances in metagenomics, metabolomics and computation amplify our means to listen in on the conversation between the gut microbiome and its host.


Assuntos
Microbioma Gastrointestinal , Microbiota , Animais , Microbioma Gastrointestinal/genética , Humanos , Metabolômica , Metagenômica
7.
Acta Biomed ; 92(3): e2021024, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34212921

RESUMO

BACKGROUND: The outbreak ofsevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has resulted inexponential rise in the number of patients getting hospitalised with corona virus disease 2019 (COVID-19). There is a paucity of data from South East Asian Region related to the predictors of clinical outcomes in these patients. This formed the basis of conducting our study. METHODS: This was an analytical cross-sectional study. Demographic, clinical, radiological and laboratory data of 125 patients was collected on admission. The study outcome was death or discharge after recovery. For univariate analysis, unpaired t-test, Chi-square and Fisher's Exact test were used. Receiver operating characteristic (ROC) curves were plotted for Sequential Organ Failure Assessment (SOFA) score and few laboratory parameters. Logistic regression was applied for multivariate analysis. RESULTS: Elderly age, ischemic heart disease and smoking were significantly associated with mortality. Elevated levels of D-dimer and lactate dehydrogenase (LDH) and reduced lymphocyte counts were the predictors of mortality. The ROCs for SOFA score curve showed a cut-off value ≥ 3.5 (sensitivity- 91.7% and specificity- 87.5%), for IL-6 the cut-off value was ≥ 37.9 (sensitivity- 96% and specificity- 78%) and for lymphocyte counts, a cut off was calculated to be less than and equal to 1.46 x 109per litre (sensitivity-75.2%and specificity- 83.3%). CONCLUSION: Old age, smoking history, ischemic heart disease and laboratory parameters including elevated D-dimer, raised LDH and low lymphocyte counts at baseline are associated with COVID-19 mortality. A higher SOFA score at admission is a poor prognosticator in COVID-19 patients.


Assuntos
COVID-19 , Adulto , Idoso , Estudos Transversais , Humanos , Índia/epidemiologia , Prognóstico , Curva ROC , Estudos Retrospectivos , SARS-CoV-2 , Centros de Atenção Terciária
8.
Global Health ; 17(1): 75, 2021 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217354

RESUMO

BACKGROUND: There has been greater recognition of the importance of country ownership in global health and development. However, operationalising country ownership to ensure the scale up and sustainability of proven interventions remains elusive at best. To address this challenge, we undertook a thematic analysis of interviews collected from representatives of local governments, public health systems, and communities in poor urban areas of East Africa, Francophone West Africa, India, and Nigeria, supported by The Challenge Initiative (TCI), aiming to rapidly and sustainably scale up evidence-based reproductive health and family planning solutions. METHODS: The main objective of this study was to explore critical elements needed for implementing and scaling evidence-based family planning interventions. The research team conducted thematic analysis of 96 stories collected using the Most Significant Change (MSC) technique between July 2018 and September 2019. After generating 55 unique codes, the codes were grouped into related themes, using TCI's model as a general analytical framework. RESULTS: Five key themes emerged: (1) strengthening local capacity and improving broader health systems, (2) shifting mindsets of government and community toward local ownership, (3) institutionalising the interventions within existing government structures, (4) improving data demand and use for better planning of health services, and (5) enhancing coordination of partners. CONCLUSION: While some themes feature more prominently in a particular region than others, taken together they represent what stakeholders perceive to be essential elements for scaling up locally-driven health programmes in urban areas in Africa and Asia.


Assuntos
Serviços de Planejamento Familiar , Educação Sexual , Governo , Programas Governamentais , Humanos , Nigéria , Pesquisa Qualitativa
9.
J Infect Public Health ; 13(11): 1755-1761, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32888872

RESUMO

OBJECTIVES: Dengue continues to remain a public health problem in many regions of the world. This study focuses on addressing the community level barriers and opportunities using a health education intervention model to aid in dengue control. METHODS: In-depth interviews of frontline workers were conducted to understand potential barriers during surveillance. A house-to-house cross-sectional survey was conducted in November 2018 among the crowded urban Pratapnagar area followed by intervention in the form of health education using pamphlets and counselling. RESULTS: The entomological indices were found to be above the critical levels in the hotspot area. 90% of the population had heard about dengue but only 51.4% had knowledge about fever as one of the symptoms of dengue. Overall knowledge among the community was good. But attitudes and practices were low and probably required more sustained health education intervention over prolonged period. The potential barriers for surveillance which were recognised during In-depth interviews were safety issues, lack of manpower and availability of dedicated vehicles, dearth of community participation and lack of inter and intra departmental coordination. CONCLUSION: The health administration needs to adopt robust surveillance and monitoring activities with inter-departmental coordination ensuring greater community participation focusing on behaviour change.


Assuntos
Dengue , Estudos Transversais , Dengue/epidemiologia , Dengue/prevenção & controle , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Índia/epidemiologia , Controle de Mosquitos
10.
J Family Med Prim Care ; 9(5): 2342-2349, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32754499

RESUMO

BACKGROUND AND OBJECTIVES: Hypertension is an important disease of public health concern. Awareness and medication adherence with diet modification have an important effect on the control of blood pressure and its associated morbidity and mortality. Therefore, this study was conducted to assess the awareness of hypertension, medication adherence, and dietary pattern in hypertensive population of western Rajasthan. MATERIALS AND METHODS: The study was hospital based cross-sectional. Blood pressure measurements were taken in a sitting position in right arm after a 5-min rest using nonmercury sphygmomanometer and required cuff size. A prevalidated and pretested questionnaire for the assessment of awareness of hypertension was used. RESULTS: Out of the total 384 patients, the majority of the patients were males (62.5%). There was a statistically significant difference found in awareness of hypertension among rural and urban patients. Nonadherence to antihypertensive medications was seen more in males (60.0%) as compared to females (40.0%). The most common reason for nonadherence was found to be forgetfulness (27.6%) followed by poor knowledge about the hypertension and ignorance of long-term treatment (22.9%). Out of the total hypertensive patient studied, 54.9% were taking normal salt intake and 45.1% of the subjects were found to be taking excess intake of salt. INTERPRETATION AND CONCLUSIONS: In the present study, good awareness about hypertension was found with urban patients. Among all the variables, education and employment status showed a positive and significant association with awareness. The most common reason of poor adherence was found to be forgetfulness behavior followed by poor knowledge and lack of awareness about hypertension.

11.
Prostate Cancer Prostatic Dis ; 23(4): 718-723, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32661432

RESUMO

BACKGROUND: The loss of PTEN function presents in up to 50% of late-stage prostate cancers, and is therefore a potential target for therapeutics. PTEN-deficient cells depend on de novo pyrimidine synthesis, a feature that can present a vulnerability. METHODS: We utilized in vitro growth assays and in vivo xenograft models to test the effect of de novo pyrimidine synthesis inhibition on prostate cell lines. RESULTS: Here, we demonstrate that PTEN-deficient prostate cancer cell lines are susceptible to inhibition of de novo pyrimidine synthesis by leflunomide. Tumor growth inhibition was observed in vitro and in vivo following leflunomide treatment, and is likely due to an overwhelming accumulation of DNA damage. CONCLUSIONS: Our work highlights that synthetic lethality arises upon the combination of PTEN loss and leflunomide treatment in prostate cancer, and may present a therapeutic opportunity for this patient population.


Assuntos
Leflunomida/toxicidade , PTEN Fosfo-Hidrolase/deficiência , Neoplasias da Próstata/patologia , Pirimidinas/metabolismo , Mutações Sintéticas Letais , Animais , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Imunossupressores/toxicidade , Masculino , Camundongos , Camundongos Nus , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias da Próstata/induzido quimicamente , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Nucleic Acids Res ; 47(11): 5573-5586, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31169889

RESUMO

Regulation of RNA polymerase II (RNAPII)-mediated transcription controls cellular phenotypes such as cancer. Phosphatase and tensin homologue deleted on chromosome ten (PTEN), one of the most commonly altered tumor suppressors in cancer, affects transcription via its role in antagonizing the PI3K/AKT signaling pathway. Using co-immunoprecipitations and proximal ligation assays we provide evidence that PTEN interacts with AFF4, RNAPII, CDK9, cyclin T1, XPB and CDK7. Using ChIP-seq, we show that PTEN co-localizes with RNAPII and binds to chromatin in promoter and putative enhancer regions identified by histone modifications. Furthermore, we show that loss of PTEN affects RNAPII occupancy in gene bodies and further correlates with gene expression changes. Interestingly, PTEN binds to promoters and negatively regulates the expression of genes involved in transcription including AFF4 and POL2RA, which encodes a subunit of RNAPII. Loss of PTEN also increased cells' sensitivity to transcription inhibition via small molecules, which could provide a strategy to target PTEN-deficient cancers. Overall, our work describes a previously unappreciated role of nuclear PTEN, which by interacting with the transcription machinery in the context of chromatin exerts an additional layer of regulatory control on RNAPII-mediated transcription.


Assuntos
Cromatina/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , RNA Polimerase II/metabolismo , Transcrição Gênica , Animais , Linhagem Celular , Células Cultivadas , Cromatina/genética , Células HEK293 , Células HeLa , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , PTEN Fosfo-Hidrolase/genética , Regiões Promotoras Genéticas/genética , Ligação Proteica , RNA Polimerase II/genética , Transdução de Sinais/genética , Fatores de Elongação da Transcrição/genética , Fatores de Elongação da Transcrição/metabolismo
13.
Infect Immun ; 87(7)2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31010813

RESUMO

Vancomycin-resistant Enterococcus faecium (VRE) is a leading cause of hospital-acquired infections. This is particularly true in immunocompromised patients, where the damage to the microbiota caused by antibiotics can lead to VRE domination of the intestine, increasing a patient's risk for bloodstream infection. In previous studies we observed that the intestinal domination by VRE of patients hospitalized to receive allogeneic bone marrow transplantation can persist for weeks, but little is known about subspecies diversification and evolution during prolonged domination. Here we combined a longitudinal analysis of patient data and in vivo experiments to reveal previously unappreciated subspecies dynamics during VRE domination that appeared to be stable from 16S rRNA microbiota analyses. Whole-genome sequencing of isolates obtained from sequential stool samples provided by VRE-dominated patients revealed an unanticipated level of VRE population complexity that evolved over time. In experiments with ampicillin-treated mice colonized with a single CFU, VRE rapidly diversified and expanded into distinct lineages that competed for dominance. Mathematical modeling shows that in vivo evolution follows mostly a parabolic fitness landscape, where each new mutation provides diminishing returns and, in the setting of continuous ampicillin treatment, reveals a fitness advantage for mutations in penicillin-binding protein 5 (pbp5) that increase resistance to ampicillin. Our results reveal the rapid diversification of host-colonizing VRE populations, with implications for epidemiologic tracking of in-hospital VRE transmission and susceptibility to antibiotic treatment.


Assuntos
DNA Bacteriano/genética , Enterococcus faecium/genética , Variação Genética , Infecções por Bactérias Gram-Positivas/microbiologia , Enterococos Resistentes à Vancomicina/genética , Animais , Evolução Biológica , Análise Mutacional de DNA , Fezes/microbiologia , Humanos , Estudos Longitudinais , RNA Ribossômico 16S/genética
14.
Cancer Discov ; 7(4): 380-390, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28255082

RESUMO

Metabolic changes induced by oncogenic drivers of cancer contribute to tumor growth and are attractive targets for cancer treatment. Here, we found that increased growth of PTEN-mutant cells was dependent on glutamine flux through the de novo pyrimidine synthesis pathway, which created sensitivity to the inhibition of dihydroorotate dehydrogenase, a rate-limiting enzyme for pyrimidine ring synthesis. S-phase PTEN-mutant cells showed increased numbers of replication forks, and inhibitors of dihydroorotate dehydrogenase led to chromosome breaks and cell death due to inadequate ATR activation and DNA damage at replication forks. Our findings indicate that enhanced glutamine flux generates vulnerability to dihydroorotate dehydrogenase inhibition, which then causes synthetic lethality in PTEN-deficient cells due to inherent defects in ATR activation. Inhibition of dihydroorotate dehydrogenase could thus be a promising therapy for patients with PTEN-mutant cancers.Significance: We have found a prospective targeted therapy for PTEN-deficient tumors, with efficacy in vitro and in vivo in tumors derived from different tissues. This is based upon the changes in glutamine metabolism, DNA replication, and DNA damage response which are consequences of inactivation of PTENCancer Discov; 7(4); 380-90. ©2017 AACR.See related article by Brown et al., p. 391This article is highlighted in the In This Issue feature, p. 339.


Assuntos
Inibidores Enzimáticos/administração & dosagem , Neoplasias/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , PTEN Fosfo-Hidrolase/genética , Pirimidinas/biossíntese , Animais , Proteínas Mutadas de Ataxia Telangiectasia/genética , Dano ao DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Di-Hidro-Orotato Desidrogenase , Fibroblastos/metabolismo , Técnicas de Inativação de Genes , Glutamina/metabolismo , Humanos , Redes e Vias Metabólicas/efeitos dos fármacos , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , PTEN Fosfo-Hidrolase/metabolismo
15.
Pacing Clin Electrophysiol ; 37(4): 481-5, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24215359

RESUMO

BACKGROUND: Implantable defibrillator (ICD) therapy improves mortality in patients at risk for sudden cardiac death. Obese patients pose challenges during ICD implantation and may have an increased risk of procedure-related complications. The comparison of acute procedural success and safety of ICD implantation in obese and nonobese patients has not been previously reported. METHODS: A total of 181 patients underwent ICD implantation at a single institution. Obesity was defined as a body mass index (BMI) greater than or equal to 30 kg/m(2) . Acute safety and efficacy data were collected and analyzed from a prospectively maintained database, with retrospective chart review, as required. RESULTS: Among the 181 patients, 58 (32.0%) were obese. Mean BMI was 36.7 ± 6.3 kg/m(2) among obese patients and was 24.6 ± 3.1 kg/m(2) among nonobese patients (P < 0.001). Successful ICD implantation occurred in 58 of 58 (100%) obese patients and 122 of 123 (99.2%) nonobese patients (P = 1.0). A complication was observed in three of 58 (5.2%) obese patients and in seven of 123 (5.7%) nonobese patients (P = 1.0). Similarly, there was no difference in acute procedural success and safety in patients receiving a cardiac resynchronization therapy (CRT)-ICD. CONCLUSIONS: Acute success and safety of ICD implantation is similar in both obese and nonobese patients. This finding extended to patients treated with a CRT-ICD and among patients with extreme obesity. Obesity should probably not be a factor in determining whether a patient is a candidate for ICD implantation.


Assuntos
Desfibriladores Implantáveis/estatística & dados numéricos , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/prevenção & controle , Obesidade/epidemiologia , Complicações Pós-Operatórias/mortalidade , Implantação de Prótese/mortalidade , Idoso , Comorbidade , District of Columbia/epidemiologia , Feminino , Humanos , Incidência , Masculino , Estudos Retrospectivos , Medição de Risco , Taxa de Sobrevida
16.
J Mol Biol ; 420(4-5): 384-99, 2012 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-22555051

RESUMO

Understanding the determinants of protein stability remains one of protein science's greatest challenges. There are still no computational solutions that calculate the stability effects of even point mutations with sufficient reliability for practical use. Amino acid substitutions rarely increase the stability of native proteins; hence, large libraries and high-throughput screens or selections are needed to stabilize proteins using directed evolution. Consensus mutations have proven effective for increasing stability, but these mutations are successful only about half the time. We set out to understand why some consensus mutations fail to stabilize, and what criteria might be useful to predict stabilization more accurately. Overall, consensus mutations at more conserved positions were more likely to be stabilizing in our model, triosephosphate isomerase (TIM) from Saccharomyces cerevisiae. However, positions coupled to other sites were more likely not to stabilize upon mutation. Destabilizing mutations could be removed both by removing sites with high statistical correlations to other positions and by removing nearly invariant positions at which "hidden correlations" can occur. Application of these rules resulted in identification of stabilizing mutations in 9 out of 10 positions, and amalgamation of all predicted stabilizing positions resulted in the most stable yeast TIM variant we produced (+8 °C). In contrast, a multimutant with 14 mutations each found to stabilize TIM independently was destabilized by 2 °C. Our results are a practical extension to the consensus concept of protein stabilization, and they further suggest the importance of positional independence in the mechanism of consensus stabilization.


Assuntos
Algoritmos , Proteínas Mutantes/química , Proteínas Mutantes/genética , Mutação/genética , Saccharomyces cerevisiae/genética , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/genética , Sequência de Aminoácidos , Dicroísmo Circular , Sequência Conservada , Modelos Químicos , Modelos Moleculares , Engenharia de Proteínas , Estabilidade Proteica
17.
BMC Cancer ; 10: 634, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-21092078

RESUMO

BACKGROUND: Rhabdoid Tumors (RTs) are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam) in order to reduce the concentration of flavopiridol needed for inhibition of RTs. METHODS: The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i) cell survival assays, ii) FACS analysis, iii) caspase activity assays, and iv) immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA) analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. RESULTS: We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G2 arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G2 arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G2 arrest, but enhanced flavopiridol- (but not 4OH-Tam-) mediated apoptosis, by enhancing caspase 2 and 3 activities. CONCLUSIONS: Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was enhanced by abrogation of p53. Our results warrant further studies investigating the combinatorial effects of flavopiridol and 4OH-Tam as a novel therapeutic strategy for RTs and other tumors that have been shown to respond to flavopiridol.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Flavonoides/administração & dosagem , Piperidinas/administração & dosagem , Tumor Rabdoide/tratamento farmacológico , Tamoxifeno/análogos & derivados , Apoptose , Caspases/biossíntese , Ciclo Celular , Sobrevivência Celular , Ensaios de Seleção de Medicamentos Antitumorais , Citometria de Fluxo , Fase G2 , Humanos , Interferência de RNA , Tamoxifeno/administração & dosagem , Proteína Supressora de Tumor p53/metabolismo
18.
J Child Orthop ; 4(6): 545-51, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22132032

RESUMO

PURPOSE: We examined the prevalence of known facial features of Marfan syndrome (MFS)-dolicocephaly, malar hypoplasia, enophthalmos, retrognathia, and down-slanting palpebral fissures-and the diagnostic utility (sensitivity, specificity, accuracy, predictive values, and likelihood ratios) of using them for screening and diagnosis. METHODS: Frontal and lateral photographs of 76 subjects with MFS (average age 18.3 years) and of 76 age- and gender-matched controls were obtained, randomized, and compiled into an online survey. Three physicians experienced with MFS rated each photograph for the presence of each feature and indicated whether each photograph triggered a suspicion for MFS. Eight non-expert orthopaedic surgeons reviewed a subset of those photographs and indicated if each triggered a suspicion for MFS. Half of the non-experts then received a brief diagnosis instructional sheet, and all non-experts were retested. The results were compared using Chi-square tests and t-tests with a significance level of P < 0.05. RESULTS: Using facial features alone, the accuracy of experienced physicians in identifying individuals with MFS was 73%. Facial features had a 54% sensitivity, a 91% specificity, an 86% positive predictive value (PPV), a 67% negative predictive value (NPV), a 6.9% positive likelihood ratio (PLR), and a 50% negative likelihood ratio (NLR) for MFS. There was no significant difference in the diagnostic accuracy between non-experts receiving and not receiving instructions. CONCLUSIONS: Facial features are more specific than sensitive for MFS. Therefore, the recognition of facial features of MFS can be used as an initial screening tool, but facial features do not have a high sensitivity for MFS.

19.
Indian J Exp Biol ; 44(9): 699-704, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16999024

RESUMO

Brain derived neurotrophic factor (BDNF) has been shown to exert trophic effects on dopaminergic neurons against 6-hydroxydopamine (6-OHDA) in young rat. Since the degeneration of substantia nigra dopaminergic neurons that occurs in Parkinson's disease is more often than not confined to elderly individuals, it is of interest to determine whether the effects of BDNF against 6 hydroxydopamine (6-OHDA) in young rats can be extended to aged animals. 6-hydroxydopamine was stereotaxically injected into the striatum of young (3-months) and aged (24-months) rats, which were treated two hours earlier with BDNF. 6-OHDA results in almost complete destruction of substantia nigra pars compacta dopaminergic neurons. BDNF injection significantly changed apomorphine induced rotations from 132 +/- 15 to 181 +/- 10, staircase test from 73 +/- 2% to 61 +/- 3%, initiation time from 7 +/- 2 to 12 +/- 1 sec, and disengage time from 80 +/- 7 to 90 +/- 5 sec in young and aged animals, respectively. It is concluded that BDNF causes the limited behavior recovery of striatal DA systems from 6-OHDA toxicity in aged animals.


Assuntos
Envelhecimento/patologia , Fator Neurotrófico Derivado do Encéfalo/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Oxidopamina/toxicidade , Doença de Parkinson/prevenção & controle , Animais , Comportamento Animal/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/administração & dosagem , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/patologia , Modelos Animais de Doenças , Fármacos Neuroprotetores/administração & dosagem , Doença de Parkinson/etiologia , Doença de Parkinson/patologia , Doença de Parkinson/fisiopatologia , Ratos , Ratos Sprague-Dawley , Substância Negra/efeitos dos fármacos , Substância Negra/patologia
20.
Ann Clin Microbiol Antimicrob ; 3: 11, 2004 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-15196306

RESUMO

BACKGROUND: Upper respiratory tract infections (URTIs) are among the most frequent reasons for physician office visits in paediatrics. Despite their predominant viral aetiology, URTIs continue to be treated with antimicrobials. We explored general practitioners' (GPs) prescribing behaviour for antimicrobials in children (< or = 16 years) with URTIs in Trinidad, using the guidelines from the Centers for Disease Control and Prevention (CDC) as a reference. METHODS: A cross-sectional study was conducted on 92 consenting GPs from the 109 contacted in Central and East Trinidad, between January to June 2003. Using a pilot-tested questionnaire, GPs identified the 5 most frequent URTIs they see in office and reported on their antimicrobial prescribing practices for these URTIs to trained research students. RESULTS: The 5 most frequent URTIs presenting in children in general practice, are the common cold, pharyngitis, tonsillitis, sinusitis and acute otitis media (AOM) in rank order. GPs prescribe at least 25 different antibiotics for these URTIs with significant associations for amoxicillin, co-amoxiclav, cefaclor, cefuroxime, erythromycin, clarithromycin and azithromycin (p < 0.001). Amoxicillin alone or with clavulanate was the most frequently prescribed antibiotic for all URTIs. Prescribing variations from the CDC recommendations were observed for all URTIs except for AOM (50%), the most common condition for antibiotics. Doctors practicing for >30 years were more likely to prescribe antibiotics for the common cold (p = 0.014). Severity (95.7%) and duration of illness (82.5%) influenced doctors' prescribing and over prescribing in general practice was attributed to parent demands (75%) and concern for secondary bacterial infections (70%). Physicians do not request laboratory investigations primarily because they are unnecessary (86%) and the waiting time for results is too long (51%). CONCLUSIONS: Antibiotics are over prescribed for paediatric URTIs in Trinidad and amoxicillin with co-amoxiclav were preferentially prescribed. Except for AOM, GPs' prescribing varied from the CDC guidelines for drug and duration. Physicians recognise antibiotics are overused and consider parents expecting antibiotics and a concern for secondary bacterial infections are prescribing pressures. Guidelines to manage URTIs, ongoing surveillance programs for antibiotic resistance, public health education on non-antibiotic strategies, and postgraduate education for rational pharmacotherapy in general practice would decrease inappropriate antibiotic use in URTIs.

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