Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Trials ; 25(1): 283, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38671470

RESUMEN

BACKGROUND: Colorectal cancer (CRC) is the second most lethal cancer in the United States (U.S.) with the highest incidence and mortality rates among African Americans (AAs) compared to other racial groups. Despite these disparities, AAs are the least likely to undergo CRC screening, have precancerous colorectal polyps removed, and have CRC detected at stages early enough for curative excision. In addition, compelling evidence links inflammatory dietary patterns to increased CRC and cardiovascular disease risk. Studies show that AA churches can successfully engage in health promotion activities including those related to cancer control. The current study seeks to leverage church-placed Community Health Workers (CHWs) to increase CRC screening and reduce CRC risk. DESIGN AND METHODS: We aim to (1) increase guideline concordant CRC screening uptake using church-placed CHWs trained in screening with a validated instrument, Brief Intervention using Motivational Interviewing, and Referral to Treatment (SBIRT); and (2) reduce dietary risk factors (inflammatory dietary patterns) linked to CRC. The latter will be addressed by culturally adapting an existing, web-based lifestyle program called Alive!. Using a Hybrid Type 1 Implementation-Effectiveness cluster randomized design, we will randomize 22 AA churches into either the dual intervention arm (CHW-led SBIRT intervention plus Alive!) or a usual care arm comprised of CRC prevention educational pamphlets and a list of CRC screening sites. We will recruit 440 subjects and evaluate the effects of both arms on screening uptake (colonoscopy, fecal DNA) (primary outcome) and dietary inflammation score (secondary outcome) at 6-month follow-up, and Life Simple7 (LS7)-a cardiovascular disease (CVD) risk score-at 6 months and 1 year (secondary outcome). Finally, guided by a racism-conscious adaptation of the Consolidated Framework for Implementation Research (CFIR), we will conduct a mixed-methods process evaluation with key stakeholders to understand multi-level influences on CRC screening and CVD risk behaviors. DISCUSSION: Church-placed CHWs are trusted influential connectors between communities and health systems. Studies have shown that these CHWs can successfully implement health prevention protocols in churches, including those related to cancer control, making them potentially important community mediators of CRC screening uptake and CRC/CVD risk reduction. TRIAL REGISTRATION: NCT05174286; clinicaltrials.gov; August 31st, 2023.


Asunto(s)
Negro o Afroamericano , Enfermedades Cardiovasculares , Neoplasias Colorrectales , Agentes Comunitarios de Salud , Detección Precoz del Cáncer , Ensayos Clínicos Controlados Aleatorios como Asunto , Humanos , Neoplasias Colorrectales/prevención & control , Neoplasias Colorrectales/diagnóstico , Enfermedades Cardiovasculares/prevención & control , Enfermedades Cardiovasculares/etnología , Factores de Riesgo , Entrevista Motivacional , Conducta de Reducción del Riesgo , Medición de Riesgo , Conocimientos, Actitudes y Práctica en Salud , Factores de Tiempo , Dieta Saludable , Derivación y Consulta , Promoción de la Salud/métodos , Valor Predictivo de las Pruebas
2.
Res Sq ; 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38659874

RESUMEN

Background: Colorectal cancer (CRC) is the second most lethal cancer in the United States (U.S.) with the highest incidence and mortality rates among African Americans (AAs) compared to other racial groups. Despite these disparities, AAs are the least likely to undergo CRC screening, have precancerous colorectal polys removed, and have CRC detected at stages early enough for curative excision. In addition, compelling evidence links inflammatory dietary patterns to increased CRC and cardiovascular disease risk. Studies show that AA churches can successfully engage in health promotion activities including those related to cancer control. The current study seeks to leverage church-placed Community Health Workers (CHWs) to increase CRC screening and reduce CRC risk. Design and Methods: We aim to (1) increase guideline concordant CRC screening uptake using church-placed CHWs trained in screening with a validated instrument, Brief Intervention using Motivational Interviewing, and Referral to Treatment (SBIRT); and (2) reduce dietary risk factors (inflammatory dietary patterns) linked to CRC. The latter will be addressed by culturally adapting an existing, web-based lifestyle program called Alive!. Using a Hybrid Type 1 Implementation-Effectiveness cluster randomized design, we will randomize 22 AA churches into either the dual intervention arm (CHW-led SBIRT intervention plus Alive!) or a usual care arm comprised of CRC prevention educational pamphlets and a list of CRC screening sites. We will recruit 440 subjects and evaluate the effects of both arms on screening uptake (colonoscopy, fecal DNA) (primary outcome) and dietary inflammation score (secondary outcome) at 6-months follow up, and Life Simple7 (LS7) - a cardiovascular disease (CVD) risk score - at 6 months and 1-year (secondary outcome). Finally, guided by a racism-conscious adaptation of the Consolidated Framework for Implementation Research (CFIR), we will conduct a mixed-methods process evaluation with key stakeholders to understand multi-level influences on CRC screening and CVD risk behaviors. Discussion: Church-placed CHWs are trusted influential connectors between communities and health systems. Studies have shown that these CHWs can successfully implement health prevention protocols in churches, including those related to cancer control, making them potentially important community mediators of CRC screening uptake and CRC/CVD risk reduction. Trial registration: NCT05174286.

3.
Curr Opin Neurol ; 36(5): 481-490, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37639461

RESUMEN

PURPOSE OF REVIEW: The purpose is to review the latest advances of brain imaging for the diagnosis of Alzheimer disease (AD). RECENT FINDINGS: Brain imaging techniques provide valuable and complementary information to support the diagnosis of Alzheimer disease in clinical and research settings. The recent FDA accelerated approvals of aducanumab, lecanemab and donanemab made amyloid-PET critical in helping determine the optimal window for anti-amyloid therapeutic interventions. Tau-PET, on the other hand, is considered of key importance for the tracking of disease progression and for monitoring therapeutic interventions in clinical trials. PET imaging for microglial activation, astrocyte reactivity and synaptic degeneration are still new techniques only used in the research field, and more studies are needed to validate their use in the clinical diagnosis of AD. Finally, artificial intelligence has opened new prospective in the early detection of AD using MRI modalities. SUMMARY: Brain imaging techniques using PET improve our understanding of the different AD-related pathologies and their relationship with each other along the course of disease. With more robust validation, machine learning and deep learning algorithms could be integrated with neuroimaging modalities to serve as valuable tools for clinicians to make early diagnosis and prognosis of AD.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Inteligencia Artificial , Estudios Prospectivos , Encéfalo/diagnóstico por imagen , Neuroimagen
4.
J Transl Med ; 20(1): 190, 2022 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-35484552

RESUMEN

BACKGROUND: The circadian system is responsible for regulating various physiological activities and behaviors and has been gaining recognition. The circadian rhythm is adjusted in a 24-h cycle and has transcriptional-translational feedback loops. When the circadian rhythm is interrupted, affecting the expression of circadian genes, the phenotypes of diseases could amplify. For example, the importance of maintaining the internal temporal homeostasis conferred by the circadian system is revealed as mutations in genes coding for core components of the clock result in diseases. This study will investigate the association between circadian genes and metabolic syndromes in a Taiwanese population. METHODS: We performed analysis using whole-genome sequencing, read vcf files and set target circadian genes to determine if there were variants on target genes. In this study, we have investigated genetic contribution of circadian-related diseases using population-based next generation whole genome sequencing. We also used significant SNPs to create a metabolic syndrome prediction model. Logistic regression, random forest, adaboost, and neural network were used to predict metabolic syndrome. In addition, we used random forest model variables importance matrix to select 40 more significant SNPs, which were subsequently incorporated to create new prediction models and to compare with previous models. The data was then utilized for training set and testing set using five-fold cross validation. Each model was evaluated with the following criteria: area under the receiver operating characteristics curve (AUC), precision, F1 score, and average precision (the area under the precision recall curve). RESULTS: After searching significant variants, we used Chi-Square tests to find some variants. We found 186 significant SNPs, and four predicting models which used 186 SNPs (logistic regression, random forest, adaboost and neural network), AUC were 0.68, 0.8, 0.82, 0.81 respectively. The F1 scores were 0.412, 0.078, 0.295, 0.552, respectively. The other three models which used the 40 SNPs (logistic regression, adaboost and neural network), AUC were 0.82, 0.81, 0.81 respectively. The F1 scores were 0.584, 0.395, 0.574, respectively. CONCLUSIONS: Circadian gene defect may also contribute to metabolic syndrome. Our study found several related genes and building a simple model to predict metabolic syndrome.


Asunto(s)
Inteligencia Artificial , Síndrome Metabólico , Ritmo Circadiano , Humanos , Síndrome Metabólico/genética , Redes Neurales de la Computación , Secuenciación Completa del Genoma
6.
J Clin Med ; 10(15)2021 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-34362147

RESUMEN

Hemolytic anemia (HA) renders erythropoietic stress on the bone marrow and has been linked to osteoporosis. In this nationwide retrospective cohort study, we examined this correlation by utilizing the Taiwan National Health Insurance Research Database (NHIRD). We identified two cohorts, matching population with and without HA in a 1:4 ratio. A total of 2242 HA patients and 8968 non-HA patients were enrolled. Patients with HA had a significantly higher cumulative incidence (log-rank test p = 0.0073), higher incidence density (5.11 vs. 3.76 per 1000 persons-years), and a 1.31-fold risk of developing osteoporosis than non-HA patients (aHR = 1.31, 95% C.I. 1.04-1.63, p = 0.01). After adjusting for age, sex, and comorbidities, patients with factors including female (aHR = 2.57, 95% C.I. 2.05-3.22, p < 0.001), age > 65 (aHR = 9.25, 95% C.I. 7.46-11.50, p < 0.001), diagnosis of cholelithiasis (aHR = 1.76, 95% C.I. 1.20-2.58, p = 0.003) and peptic ulcer disease (aHR = 1.87, 95% C.I. 1.52-2.29, p < 0.001) had significantly higher risk of osteoporosis. We propose that this correlation may be related to increased hematopoietic stress, increased consumption of nitric oxide (NO) by hemolysis, and the inhibitory effects of iron supplements on osteogenesis through the receptor activator of nuclear factor κB ligand (RANKL)/Osteoprotegerin pathway and the Runt-related transcription factor 2 (RUNX2) factor. Our findings suggest that patients with hemolytic anemia are at a higher risk of developing osteoporosis, and it would be in the patient's best interest for physicians to be aware of this potential complication and offer preventative measures.

8.
Sci Rep ; 11(1): 10496, 2021 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-34006944

RESUMEN

Since iron is essential for neurotransmitter synthesis, decreased iron stores might lead to reduced production of biogenic amines which phenomenon was shown in Fibromyalgia (FM) patients. The aims are to investigate the association of iron deficiency anemia (IDA) and FM and to find the effects of different interventions. We conducted a study using the Taiwan National Health Insurance Research Database. The IDA cohort consisted of 13,381 patients with newly diagnosed IDA between 2000 and 2008. Each patient with IDA was frequency-matched with one people without IDA, by sex, age and index year. The Cox proportional hazards regression analysis was conducted to estimate the association between IDA and FM risk. The event was the occurrence of FM. The overall incidence density rate of FM in the IDA cohort was higher than in the non-IDA cohort with a multivariable Cox proportional hazards model measured adjusted hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.13-1.25). When using non-IDA group as reference, we compared with different therapies for IDA. The adjusted HRs of FM were 1.38 (95% CI = 1.30-1.47), 1.10 (95% CI = 1.03-1.16), 1.18 (95% CI = 0.98-1.43) and 0.73 (95% CI = 0.58-0.90) for IDA patient without therapy, iron supplement alone, blood transfusion alone and both iron supplement and blood transfusion respectively. Our results suggest IDA is associated with an increased risk of FM. All patients should have iron supplementation both to correct anemia and replenish body stores.


Asunto(s)
Anemia Ferropénica/complicaciones , Fibromialgia/complicaciones , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Taiwán
9.
Sci Rep ; 11(1): 7520, 2021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33824394

RESUMEN

Chronic Fatigue Syndrome (CFS) has been defined as unexplained relapsing or persistent fatigue for at least 6 consecutive months. Immuno-inflammatory pathway, bacterial infection, and other causes play essential roles in CFS. Helicobacter pylori infection is one of the most common causes of foregut inflammation, leading to peptic ulcer disease (PUD). This study aimed to analyze the risk of CFS development between patients with and without PUD. Other related factors were also analyzed. We performed a retrospective, nationwide cohort study identifying patients with or without PUD respectively by analyzing the Longitudinal Health Insurance Database 2000 (LHID2000), Taiwan. The overall incidence of CFS was higher in the PUD cohort than in the non- PUD cohort (HR = 2.01, 95% CI = 1.75-2.30), with the same adjusted HR (aHR) when adjusting for age, sex, and comorbidities. The sex-specific PUD cohort to the non-PUD cohort relative risk of CFS was significant in both genders. The age-specific incidence of CFS showed incidence density increasing with age in both cohorts. There is an increased risk of developing CFS following PUD, especially in females and the aging population. Hopefully, these findings can prevent common infections from progressing to debilitating, chronic conditions such as CFS.


Asunto(s)
Síndrome de Fatiga Crónica/etiología , Úlcera Péptica/complicaciones , Úlcera Péptica/epidemiología , Adulto , Anciano , Antibacterianos/uso terapéutico , Estudios de Cohortes , Síndrome de Fatiga Crónica/fisiopatología , Femenino , Infecciones por Helicobacter/epidemiología , Helicobacter pylori , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Úlcera Péptica/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Taiwán/epidemiología
10.
PeerJ ; 8: e8963, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32435531

RESUMEN

BACKGROUND: Vancomycin, the first line antibiotic for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, is often administered inappropriately when MIC is greater than 2 µg/mL, including 'susceptible' strains. This study assessed the discordance of vancomycin minimum inhibitory concentration (MIC) for methicillin-resistant Staphylococcus aureus (MRSA). METHODS: In total, 229 MRSA isolates from blood cultures collected between 2009 and 2015 at a tertiary hospital in Taiwan were examined. The MICs of vancomycin were measured using Vitek 2, E-test, and standard broth microdilution at the level of 2 µg/mL. RESULTS: The geometric mean of the MICs of hospital-acquired MRSA was higher than that of community-acquired MRSA (P < 0.001), with the exact agreement rates (with broth microdilution) at 2 µg/mL being 53.6% in Vitek 2 and 86.7% in E-test. Overall, E-test (98.1%) had more categorical accordance than did Vitek 2 (94.0%; P = 0.026). Vitek 2 had a tendency to overestimate MRSA in high-MIC isolates, whereas E-test inclined underestimation in low-MIC isolates. Surprisingly, the discordance rates of MRSA vancomycin MICs were higher in hospital-acquired isolates (13.3%-17.0%) than in community-acquired isolates (6.2%-7.0%). CONCLUSION: The Infectious Diseases Society of America recommends the use of alternative antimicrobial agents when vancomycin MIC is ≥ 2 µg/mL; in this study, only 53.6% of the isolates tested using Vitek 2 showed a high MIC in the broth microdilution method. Accurate identification of the resistance profile is a key component of antimicrobial stewardship programs. Therefore, to reduce inappropriate antibiotic use and mitigate the emergence of resistant strains, we recommend using complementary tests such as E-test or Broth microdilution to verify the MIC before administering second-line antibiotics. STRENGTHS: (1) We compared the categorical agreement between different methods measuring MRSA MICs level. (2) Physicians should incorporate this information and consider a complementary test to verify the appropriateness of the decision of shifting vancomycin to second-line antibiotic treatment to improve patients' prognosis. (3) MRSA-vancomycin MICs at a cutoff of 2 µg/mL obtained using Vitek II exhibited a higher sensitivity level and negative predictive value than those obtained using E-test in the prediction of categorical agreement with standard broth microdilution. LIMITATION: (1) Our research was based on a single hospital-based study. (2) The MRSA strains in this study were stored for more than 12 months after isolation. (3) We did not collect information on clinical prognosis.

12.
BMC Womens Health ; 20(1): 23, 2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-32033559

RESUMEN

BACKGROUND: Little is known about the ocular surface changes over the menstrual cycle in young women and the interactions with lifestyle factors. Therefore, the purpose of this study was to explore the associations between modifiable lifestyle factors and menstrual cycle phases on the ocular signs and symptoms of dry eye in young healthy women. METHODS: This was a prospective 1-month observational study. Thirty young healthy women with regular, 24 to 32-day menstrual cycles were recruited. Participants attended three visits at day 7, 14, and 21 (± 1) of their menstrual cycle. At baseline, general health questionnaire was conducted. At each visit, symptomology was quantified using Ocular Surface Disease Index (OSDI) and overall ocular comfort (OOC, visual analogue scale). Ocular signs were assessed using Efron scales, tear break-up time (TBUT) and phenol red thread (PRT). Pearson's correlation was used to determine associations between variables at each visit. RESULTS: A total of 26 participants (mean age = 22.3 ± 3.7 years) with an average menstrual cycle of 28.3 ± 1.3 days completed the 3 visits. The interaction between signs/symptoms and lifestyle factors changed over the cycle. At the follicular phase (day 7), lifestyle factors such diet and levels of stress were correlated with PRT and OSDI, (r = - 0.4, p = 0.022; r = 0.4, p = 0.045 respectively). At the ovulation phase (day 14), the general health score was correlated with OOC scores (r = 0.4, p = 0.047). At day 14, exercise frequency correlated with PRT (r = - 0.4, p = 0.028) and caffeine intake was positively correlate with both; TBUT (r = 0.5, p = 0.020) and PRT (r = 0.5, p = 0.014). At the luteal phase (day 21), we found no correlations between lifestyle factors and dry eye signs or symptoms. CONCLUSIONS: The associations between lifestyle factors and objective and subjective ocular surface assessment appeared to be more pronounced during the ovulation phase of the menstrual cycle compared to the follicular and luteal phases. Misalignment of these factors with the ocular health during the luteal phase could be attributed to central sensitization and changes in levels of luteinising hormone. Natural hormonal changes during menstrual cycle should be considered for diagnosis and treatment of dry eye in young healthy women.


Asunto(s)
Síndromes de Ojo Seco/diagnóstico , Estilo de Vida , Ciclo Menstrual , Adulto , Ojo/patología , Femenino , Fase Folicular , Humanos , Fase Luteínica , Hormona Luteinizante/sangre , Estudios Prospectivos , Lágrimas , Adulto Joven
13.
J Transl Med ; 17(1): 154, 2019 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-31088562

RESUMEN

BACKGROUND: The onset of chronic fatigue syndrome (CFS) has been shown to be associated with several immunological conditions such as infections or atopy. The aim of this study was to clarify the risk of chronic fatigue syndrome following the diagnosis of psoriasis, an immune-related dermatological disease, by analyzing the National Health Insurance Research Database of Taiwan. METHOD: 2616 patients aged 20 years or older with newly diagnosed psoriasis during 2004-2008 and 10,464 participants without psoriasis were identified. Both groups were followed up until the diagnoses of CFS were made at the end of 2011. RESULTS: The relationship between psoriasis and the subsequent risk of CFS was estimated through Cox proportional hazards regression analysis, with the incidence density rates being 2.27 and 3.58 per 1000 person-years among the non-psoriasis and psoriasis populations, respectively (adjusted hazard ratio [HR] = 1.48, with 95% confidence interval [CI] 1.07-2.06). In the stratified analysis, the psoriasis group were consistently associated with a higher risk of CFS in male sex (HR = 2.05, 95% CI 1.31-3.20) and age group of ≥ 60 years old (HR = 2.32, 95% CI 1.33-4.06). In addition, we discovered that the significantly increased risk of CFS among psoriasis patients is attenuated after they receive phototherapy and/or immunomodulatory drugs. CONCLUSIONS: The data from this population-based retrospective cohort study revealed that psoriasis is associated with an elevated risk of subsequent CFS, which is differentiated by sex and age.


Asunto(s)
Síndrome de Fatiga Crónica/epidemiología , Síndrome de Fatiga Crónica/etiología , Psoriasis/complicaciones , Adulto , Estudios de Cohortes , Comorbilidad , Intervalos de Confianza , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Factores de Riesgo , Índice de Severidad de la Enfermedad , Taiwán/epidemiología , Adulto Joven
14.
Stem Cell Investig ; 2: 2, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-27358870

RESUMEN

BACKGROUND: Myeloproliferative neoplasms (MPNs) are blood malignancies manifested in increased production of red blood cells, white blood cells, and/or platelets. Myelofibrosis is a subtype of MPNs characterized by the formation of scar-like tissues in the bone marrow due to abnormal hematopoiesis. It is considered a disease of both hematopoietic stem cells and stem cell niches. Patients with myelofibrosis have very poor prognosis, and there is no effective treatment so far. Myelofibrosis has routinely been detected by using histochemical staining methods which produce qualitative rather than quantitative results. In this study, we developed a quantitative assay of bone marrow myelofibrosis in JAK2V617F transgenic mice by determining hydroxyproline. METHODS: The JAK2V617F transgenic mice's tissue was collected to detect the bone marrow myelofibrosis. Statistical analyses were performed using the GraphPad Prism program. Differences of samples between two groups were accessed using t tests. P values less than 0.05 (2-tailed) were considered significantly different. RESULTS: We developed a quantitative method for detecting myelofibrosis by analyzing the content of hydroxyproline, a modified amino acid largely restricted to collagen which forms the fibrotic structure in bone marrow tissues. Our study also demonstrated age-dependent development of bone marrow myelofibrosis in JAK2V617F transgenic mice. CONCLUSIONS: In the present study, we have developed a new method for detecting bone marrow myelofibrosis by analyzing hydroxyproline contents. The method is highly sensitive and accurate. It provides more accurate, representative, and quantitative information than histochemical analyses. We believe that this method should find wide applications for analyzing the progression of myelofibrosis and efficacy of drug treatment.

15.
Life Sci ; 90(17-18): 682-8, 2012 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-22472425

RESUMEN

AIMS: Macrophages must function in an inflammatory environment of high oxidative stress due to the production of various oxidants. Hypochlorous acid (HOCl) is a potent cytotoxic agent generated by neutrophils and macrophages within inflammatory sites. This study determines whether glutathione is the key factors governing macrophage resistance to HOCl. MAIN METHODS: Human monocyte derived macrophages (HMDM) were differentiated from human monocytes prepared from human blood. The HMDM cells were exposed to micromolar concentrations of HOCl and the timing of the cell viability loss was measured. Cellular oxidative damage was measured by loss of glutathione, cellular ATP, tyrosine oxidation, and inactivation of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). KEY FINDINGS: HOCl causes a rapid loss in HMDM cell viability above threshold concentrations. The cell death occurred within 10 min of treatment with the morphological characteristics of necrosis. The HOCl caused the extensive cellular protein oxidation with the loss of tyrosine residue and inactivation of GAPDH, which was accompanied with the loss of cellular ATP. This cellular damage was only observed after the loss of intracellular GSH from the cell. Removal of intracellular GSH with diethyl maleate (DEM) increased the cells' sensitivity to HOCl damage while protecting the intracellular GSH pool with the antioxidant 7,8-dihydroneopterin prevented the HOCl mediated viability loss. Variations in the HOCl LD(50) for inducing cell death were strongly correlated with initial intracellular GSH levels. SIGNIFICANCE: In HMDM cells scavenging of HOCl by intracellular glutathione is sufficient to protect against oxidative loss of key metabolic functions within the cells.


Asunto(s)
Citotoxinas/efectos adversos , Glutatión/metabolismo , Ácido Hipocloroso/efectos adversos , Macrófagos/metabolismo , Adenosina Trifosfato/metabolismo , Antioxidantes/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Humanos , Macrófagos/citología , Monocitos/citología , Neopterin/análogos & derivados , Neopterin/farmacología , Estrés Oxidativo
16.
Biochim Biophys Acta ; 1823(2): 420-9, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22008466

RESUMEN

The abundance of dead macrophages in close proximity to HOCl-modified proteins in advanced atherosclerotic plaques implicates HOCl in the killing of macrophages and the formation of the necrotic core region. The mechanism of HOCl mediated death of macrophages was unknown, so using human monocyte derived macrophages (HMDM) we here have shown that HOCl causes a rapid necrotic cell death characterized by loss of MTT reduction, cellular ATP and cell lysis without caspase-3 activation in HMDM cells. The HOCl causes a rise in cytosolic calcium level via the plasma membrane L- and T-type calcium channels and endoplasmic reticulum RyR channel. Blocking of the calcium channels or the addition of calpain inhibitors prevents the HOCl mediated loss of mitochondrial potential, lysosome failure and HMDM cell death. Blocking MPT-pore formation with cyclosporin A also prevents the loss of mitochondrial membrane potential, lysosomal destabilization and HMDM cell death. Blocking the calcium mitochondrial uniporter with ruthenium red also blocks the loss of mitochondrial potential but only at high concentrations. HOCl appears to cause HMDM cell death through destabilization of cytosolic calcium control resulting in the failure of both the mitochondria and lysosomes.


Asunto(s)
Ionóforos de Calcio/farmacología , Calcio/metabolismo , Calpaína/metabolismo , Ácido Hipocloroso/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/patología , Necrosis , Calcimicina/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Caspasa 3/metabolismo , Ciclosporina/farmacología , Dantroleno/farmacología , Inhibidores Enzimáticos/farmacología , Flunarizina/farmacología , Humanos , Lisosomas/efectos de los fármacos , Macrófagos/fisiología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Relajantes Musculares Centrales/farmacología , Nifedipino/farmacología , Verapamilo/farmacología
17.
Biochem Biophys Res Commun ; 407(1): 98-102, 2011 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-21371422

RESUMEN

Tea is widely consumed all over the world. Studies have demonstrated the role of tea in prevention and treatment of various chronic diseases including diabetes and obesity, but the underlying mechanism is unclear. PTP1B is a widely expressed tyrosine phosphatase which has been defined as a target for therapeutic drug development to treat diabetes and obesity. In screening for inhibitors of PTP1B, we found that aqueous extracts of teas exhibited potent PTP1B inhibitory effects with an IC50 value of 0.4-4 g dry tea leaves per liter of water. Black tea shows the strongest inhibition activities, followed by oolong and then by green tea. Biochemical fractionations demonstrated that the major effective components in tea corresponded to oxidized polyphenolic compounds. This was further verified by the fact that tea catechins became potent inhibitors of PTP1B upon oxidation catalyzed by tyrosinases. When applied to cultured cells, tea extracts induced tyrosine phosphorylation of cellular proteins. Our study suggests that some beneficial effects of tea may be attributed to the inhibition of PTP1B.


Asunto(s)
Camellia sinensis/química , Inhibidores de Proteínas Quinasas/farmacología , Proteína Tirosina Fosfatasa no Receptora Tipo 1/antagonistas & inhibidores , Té/química , Animales , Catequina/química , Catequina/farmacología , Cromatografía de Fase Inversa , Humanos , Ratones , Monofenol Monooxigenasa/química , Células 3T3 NIH , Oxidación-Reducción , Fosforilación , Inhibidores de Proteínas Quinasas/química , Tirosina/química , Tirosina/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA