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3.
Eur Heart J Case Rep ; 7(8): ytad333, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37547373

RESUMO

Background: Pericarditis is a common pericardial disorder that is frequently accompanied by a pericardial friction rub, which can be detected during a physical examination. Although patients' awareness of cardiac murmurs and vascular bruits has been extensively reported, there are no reports on patients' self-awareness of a pericardial friction rub. Case summary: We present the first case of a patient with acute pericarditis associated with objective self-awareness of a pericardial friction rub, which we recorded with an electronic stethoscope and confirmed the sound with the patient. The patient had a recent history of three-vessel coronary artery bypass grafting and presented with a progressively worsening, rhythmic, and 'sandpaper-scratching' sound in both ears. The sound was more pronounced in the left lateral decubitus position. The symptom resolved with colchicine therapy and was associated with concomitant resolution of the pericardial friction rub. Discussion: This is the first documented case of a patient demonstrating objective self-awareness of a pericardial rub resulting from acute pericarditis associated with post-pericardiotomy syndrome. Tinnitus refers to the perception of an auditory sensation that can be subjective or objective, depending on whether it is heard only by the individual or can also be heard by an observer. While objective tinnitus caused by cardiovascular conditions has been previously reported, no cases have attributed the pericardial friction rub as the underlying cause. Therefore, we suggest using the term pericardial rub tinnitus to describe this unique phenomenon.

4.
Eur Cell Mater ; 43: 112-129, 2022 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35312032

RESUMO

3D cell culture systems based on biological scaffold materials obtainable from both animal and human tissues constitute very interesting tools for cell therapy and personalised medicine applications. The white adipose tissue (AT) extracellular matrix (ECM) is a very promising biomaterial for tissue engineering due to its easy accessibility, malleability and proven biological activity. In the present study, human dental pulp stem cells (hDPSCs) were combined in vitro with ECM scaffolds from porcine and human decellularised adipose tissues (pDAT, hDAT) processed as 3D solid foams, to investigate their effects on the osteogenic differentiation capacity and bone matrix production of hDPSCs, compared to single-protein-based 3D solid foams of collagen type I and conventional 2D tissue-culture-treated polystyrene plates. pDAT solid foams supported the osteogenic differentiation of hDPSCs to similar levels to collagen type I, as assessed by alkaline phosphatase and alizarin red stainings, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and osteocalcin/bone gamma-carboxyglutamate protein (BGLAP) immunostaining. Interestingly, hDAT solid foams showed a markedly lower capacity to sustain hDPSC osteogenic differentiation and matrix calcification and a higher capacity to support adipogenesis, as assessed by RT-qPCR and oil red O staining. White ATs from both human and porcine origins are relatively abundant and available sources of raw material to obtain high quality ECM-derived biomedical products. These biomaterials could have promising applications in tissue engineering and personalised clinical therapy for the healing and regeneration of lesions involving not only a loss of calcified bone but also its associated soft non-calcified tissues.


Assuntos
Colágeno Tipo I , Osteogênese , Tecido Adiposo , Animais , Diferenciação Celular , Células Cultivadas , Polpa Dentária , Humanos , Células-Tronco , Suínos , Engenharia Tecidual , Alicerces Teciduais
5.
BMC Bioinformatics ; 22(1): 476, 2021 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-34602053

RESUMO

BACKGROUND: Quantitative, reverse transcription PCR (qRT-PCR) is currently the gold-standard for SARS-CoV-2 detection and it is also used for detection of other virus. Manual data analysis of a small number of qRT-PCR plates per day is a relatively simple task, but automated, integrative strategies are needed if a laboratory is dealing with hundreds of plates per day, as is being the case in the COVID-19 pandemic. RESULTS: Here we present shinyCurves, an online shiny-based, free software to analyze qRT-PCR amplification data from multi-plate and multi-platform formats. Our shiny application does not require any programming experience and is able to call samples Positive, Negative or Undetermined for viral infection according to a number of user-defined settings, apart from providing a complete set of melting and amplification curve plots for the visual inspection of results. CONCLUSIONS: shinyCurves is a flexible, integrative and user-friendly software that speeds-up the analysis of massive qRT-PCR data from different sources, with the possibility of automatically producing and evaluating melting and amplification curve plots.


Assuntos
COVID-19 , Análise de Dados , Humanos , Pandemias , Reação em Cadeia da Polimerase em Tempo Real , SARS-CoV-2
7.
Curr Cardiol Rep ; 23(4): 24, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33655453

RESUMO

PURPOSE OF THE REVIEW: The purpose of this review is to examine recent evidence supporting CV safety profile and improvement of CV outcomes of some of the newer classes of diabetic medications. RECENT FINDINGS: Diabetes mellitus (DM) is associated with increased risk of cardiovascular disease (CVD). Thus, CVD management is critical in diabetic patients. Since 2008, the US Food and Drug Administration (FDA) has mandated that all newer diabetic medications should establish cardiovascular safety before it is approved for use. Diabetic medications that also lower CV risk would be a significant advancement as shown in recent studies. There are 3 new class of diabetic medications: Dipeptidyl peptidase-4 inhibitors (DPP-4), glucagon-like peptide receptor agonists (GLP-1 RA), and sodium-glucose cotransporter type 2 (SGLT 2) inhibitors which have established both CV safety and improvement in CV outcomes with some drugs. In patients with type 2 diabetes and established atherosclerotic cardiovascular disease, multiple atherosclerotic cardiovascular disease risk factors, or diabetic kidney disease, a sodium-glucose cotransporter 2 inhibitor, or a glucagon-like peptide 1 receptor agonist with demonstrated cardiovascular benefit is recommended to reduce the risk of major adverse cardiovascular events.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Preparações Farmacêuticas , Inibidores do Transportador 2 de Sódio-Glicose , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Glucose , Humanos , Hipoglicemiantes/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico
8.
Biology (Basel) ; 9(12)2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33260962

RESUMO

The conversion of healthy stem cells into cancer stem cells (CSCs) is believed to underlie tumor relapse after surgical removal and fuel tumor growth and invasiveness. CSCs often arise from the malignant transformation of resident multipotent stem cells, which are present in most human tissues. Some organs, such as the gut and the brain, can give rise to very aggressive types of cancers, contrary to the dental pulp, which is a tissue with a very remarkable resistance to oncogenesis. In this review, we focus on the similarities and differences between gut, brain and dental pulp stem cells and their related CSCs, placing a particular emphasis on both their shared and distinctive cell markers, including the expression of pluripotency core factors. We discuss some of their similarities and differences with regard to oncogenic signaling, telomerase activity and their intrinsic propensity to degenerate to CSCs. We also explore the characteristics of the events and mutations leading to malignant transformation in each case. Importantly, healthy dental pulp stem cells (DPSCs) share a great deal of features with many of the so far reported CSC phenotypes found in malignant neoplasms. However, there exist literally no reports about the contribution of DPSCs to malignant tumors. This raises the question about the particularities of the dental pulp and what specific barriers to malignancy might be present in the case of this tissue. These notable differences warrant further research to decipher the singular properties of DPSCs that make them resistant to transformation, and to unravel new therapeutic targets to treat deadly tumors.

9.
J Crohns Colitis ; 13(8): 996-1002, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30721954

RESUMO

BACKGROUND AND AIMS: The aims of this study were to determine the prevalence of fatigue in patients with inflammatory bowel disease [IBD], to identify the factors associated with fatigue and its severity, to assess the impact of fatigue on quality of life [QoL], and to evaluate the relationship between fatigue and sleep disorders. METHODS: This was a prospective multicentre study conducted at 22 Spanish centres. Consecutive patients followed at IBD Units were included. Fatigue was evaluated with the Fatigue Severity Scale [FSS] and the Fatigue Impact Scale [FIS]. Quality of life and sleep quality were assessed using the IBD Questionnaire-Short Form [IBDQ-9] and the Pittsburgh Sleep Quality Index [PSQI], respectively. RESULTS: A total of 544 consecutive adult IBD patients were included [50% women, mean age 44 years, 61% Crohn's disease]. The prevalence of fatigue was 41% (95% confidence interval [CI] = 37-45%). The variables associated with an increased risk of fatigue were: anxiety [OR = 2.5, 95% CI = 1.6-3.7], depression [OR = 2.4, 95% CI = 1.4-3.8], presence of extraintestinal manifestations [EIMs] [OR = 1.7, 95% CI = 1.1-2.6], and treatment with systemic steroids [OR = 2.8, 95% CI = 1.4-5.7]. The presence of EIMs [regression coefficient, RC = 8.2, 95% CI = 2.3-14.2], anxiety [RC = 25.8, 95% CI = 20.0-31.5], depression [RC = 30.6, 95% CI = 24.3-37.0], and sleep disturbances [RC = 15.0, 95% CI = 9.3-20.8] were associated with severity of fatigue. Patients with fatigue had a significantly decreased IBDQ-9 score [p < 0.001]. CONCLUSIONS: The prevalence of fatigue in IBD patients is remarkably high and has a negative impact on QoL. Therapy with systemic steroids is associated with an increased risk of fatigue. The severity of fatigue is associated with anxiety, depression, sleep disorders, and the presence of EIMs. Fatigue was not associated with anaemia, disease activity or anti-TNF therapy.


Assuntos
Fadiga , Glucocorticoides , Doenças Inflamatórias Intestinais , Qualidade de Vida , Adulto , Ansiedade/diagnóstico , Ansiedade/epidemiologia , Ansiedade/fisiopatologia , Depressão/diagnóstico , Depressão/epidemiologia , Depressão/fisiopatologia , Fadiga/diagnóstico , Fadiga/epidemiologia , Fadiga/etiologia , Fadiga/psicologia , Feminino , Glucocorticoides/efeitos adversos , Glucocorticoides/uso terapêutico , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/psicologia , Doenças Inflamatórias Intestinais/terapia , Masculino , Prevalência , Estudos Prospectivos , Fatores de Risco , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/epidemiologia , Transtornos do Sono-Vigília/fisiopatologia , Espanha/epidemiologia , Inquéritos e Questionários
10.
Trop Anim Health Prod ; 50(3): 629-634, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29274053

RESUMO

This study evaluated the pregnancy rate (PR) after timed artificial insemination (TAI) in water buffalo (Bubalus bubalis) during both non-breeding and breeding season, using either a new or reused intravaginal device (IVD) with two different progesterone concentrations. A total of 247 dairy buffalo cows were randomly assigned using a two-by-three factorial design and four replicates to the following groups: (1) new intravaginal device (IVD-New: DIB®, 1.0 g of P4, n = 51 or CIDR®, 1.38 g of P4, n = 55); (2) intravaginal device previously used once (9 days) (IVD-Used1x: DIB, n = 40 or CIDR, n = 51); or (3) intravaginal device previously used twice (18 days) (IVD-Used2x: DIB, n = 27 or CIDR, n = 23). On day 0, animals received the IVD plus 10.5 µg of buserelin acetate (GnRH) intramuscularly. On day 9, the devices were removed and 25 mg of PGF2α plus 500 IU of eCG was given intramuscularly. On day 11 (48 h after IVD withdrawal), animals received 10.5 µg of GnRH and were artificially inseminated 8-12 h later. Data were analyzed using Proc Logistic of SAS®. Animals that received IVD-New-DIB, had a significantly higher PR (62.7%; P = 0.0193) compared to animals that received IVD-New-CIDR (40%). Pregnancy rate was not negatively affected by reusing both types of IVD. Overall PR (new and reused devices) was higher (P = 0.0055) in the DIB group (62.7%) compared to the CIDR group (45%). In conclusion, PR was higher in buffaloes treated with devices containing 1.0 g of P4 (DIB®) compared to those receiving 1.38 g of P4 (CIDR®). Reusing the intravaginal devices did not affect negatively PR/TAI, suggesting that P4 concentrations within the TAI protocols in water buffaloes could be reduced, without impairing their fertility.


Assuntos
Administração Intravaginal , Búfalos/fisiologia , Sincronização do Estro/métodos , Inseminação Artificial/veterinária , Taxa de Gravidez , Progesterona/administração & dosagem , Animais , Busserrelina/administração & dosagem , Bovinos , Feminino , Fertilidade/efeitos dos fármacos , Geografia , México , Gravidez , Prenhez , Estações do Ano
11.
Am J Gastroenterol ; 112(1): 120-131, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27958281

RESUMO

OBJECTIVES: The aims of this study were to assess the risk of relapse after discontinuation of anti-tumor necrosis factor (anti-TNF) drugs in patients with inflammatory bowel disease (IBD), to identify the factors associated with relapse, and to evaluate the overcome after retreatment with the same anti-TNF in those who relapsed. METHODS: This was a retrospective, observational, multicenter study. IBD patients who had been treated with anti-TNFs and in whom these drugs were discontinued after clinical remission was achieved were included. RESULTS: A total of 1,055 patients were included. The incidence rate of relapse was 19% and 17% per patient-year in Crohn's disease and ulcerative colitis patients, respectively. In both Crohn's disease and ulcerative colitis patients in deep remission, the incidence rate of relapse was 19% per patient-year. The treatment with adalimumab vs. infliximab (hazard ratio (HR)=1.29; 95% confidence interval (CI)=1.01-1.66), elective discontinuation of anti-TNFs (HR=1.90; 95% CI=1.07-3.37) or discontinuation because of adverse events (HR=2.33; 95% CI=1.27-2.02) vs. a top-down strategy, colonic localization (HR=1.51; 95% CI=1.13-2.02) vs. ileal, and stricturing behavior (HR=1.5; 95% CI=1.09-2.05) vs. inflammatory were associated with a higher risk of relapse in Crohn's disease patients, whereas treatment with immunomodulators after discontinuation (HR=0.67; 95% CI=0.51-0.87) and age (HR=0.98; 95% CI=0.97-0.99) were protective factors. None of the factors were predictive in ulcerative colitis patients. Retreatment of relapse with the same anti-TNF was effective (80% responded) and safe. CONCLUSIONS: The incidence rate of inflammatory bowel disease relapse after anti-TNF discontinuation is relevant. Some predictive factors of relapse after anti-TNF withdrawal have been identified. Retreatment with the same anti-TNF drug was effective and safe.


Assuntos
Adalimumab/uso terapêutico , Antirreumáticos/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/tratamento farmacológico , Desprescrições , Fatores Imunológicos/uso terapêutico , Infliximab/uso terapêutico , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Colite Ulcerativa/fisiopatologia , Colo , Constrição Patológica , Doença de Crohn/fisiopatologia , Progressão da Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Seguimentos , Humanos , Íleo , Incidência , Doenças Inflamatórias Intestinais/tratamento farmacológico , Masculino , Mesalamina/uso terapêutico , Metotrexato/uso terapêutico , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Proteção , Recidiva , Indução de Remissão , Retratamento , Estudos Retrospectivos , Fatores de Risco , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto Jovem
12.
Prog Cardiovasc Dis ; 57(5): 510-20, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25475072

RESUMO

Pharmacologic interventions are an integral component of peripheral artery disease (PAD) management, supported by high-quality clinical studies. Those affected by this potentially debilitating and life-threatening disease process often have multiple contributing conditions, such as tobacco abuse, diabetes, hypertension, and hyperlipidemia. In addition to medications aimed at improving claudication symptoms, risk factor modification and appropriate use of antiplatelet agents are essential to decreasing rates of major adverse clinical events and improving vessel patency following intervention. While lower extremity PAD is increasingly recognized as a prevalent condition, affected individuals remain undertreated with optimal pharmacotherapy. Novel approaches to treatment of PAD include stem cell therapy, which may play a beneficial role in those with minimal revascularization options but disease placing them at high risk for limb amputation. Additionally, timely initiation of optimal pharmacotherapy represents a cost-effective approach to management of this chronic condition.


Assuntos
Fármacos Cardiovasculares/uso terapêutico , Doença Arterial Periférica/tratamento farmacológico , Animais , Terapia Genética , Humanos , Salvamento de Membro , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/etiologia , Doença Arterial Periférica/fisiopatologia , Inibidores da Agregação Plaquetária/uso terapêutico , Guias de Prática Clínica como Assunto , Fatores de Risco , Comportamento de Redução do Risco , Transplante de Células-Tronco , Resultado do Tratamento , Vasodilatadores/uso terapêutico
13.
J Phys Chem B ; 114(48): 15985-90, 2010 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-21077591

RESUMO

It has been accepted for many years that functionally important motions are crucial to binding properties of ligands in such molecules as hemoglobin and myoglobin. In enzymatic reactions, theory and now experiment are beginning to confirm the importance of motions on a fast (ps) time scale in the chemical step of the catalytic process. What is missing is a clear physical picture of how slow conformational fluctuations are related to the fast motions that have been identified as crucial. This paper presents a theoretical analysis of this issue for human heart lactate dehydrogenase. We will examine how slow conformational motions bring the system to conformations that are distinguished as catalytically competent because they favor specific fast motions.


Assuntos
Biocatálise , L-Lactato Desidrogenase/metabolismo , Simulação por Computador , Coração , Humanos , L-Lactato Desidrogenase/química , Modelos Moleculares , Movimento (Física) , Movimento , Conformação Proteica , Teoria Quântica , Termodinâmica , Fatores de Tempo
14.
Rev Esp Enferm Dig ; 101(10): 697-705, 2009 Oct.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-19899937

RESUMO

BACKGROUND: the role that cytomegalovirus (CMV) plays in inflammatory bowel disease (IBD) is controversial. The diagnosis of CMV infection in IBD depends on viral identification with hematoxylin-eosin (HE) or immunohistochemistry (IHC). Our aim was to compare the sensitivity of HE and IHC for this diagnosis in IBD patients. PATIENTS AND METHODS: a case-control study. Our database was searched for IBD patients with HE- or IHC-based CMV-positivity from 1997 to 2007. Controls were selected among IBD inpatients matched for age and year of diagnosis with CMV. Their clinical characteristics were analyzed. HE and IHC were performed on biopsies from cases and controls at 6 months before and after inclusion in the study. In the statistical analysis, p values below 0.05 were considered significant. RESULTS: ten IBD patients with CMV infection were identified. IBD-CMV patients were more steroid-resistant or steroid-dependent (p = 0.03), and underwent a higher number of colonic biopsies (p = 0.03). From 97 biopsies analyzed, 12 were HE-negative and IHC-positive, and 3 showed reversed results. The sensitivity of HE was 58.6%, 95% CI (38.9-78.3), and that of IHC was 89.7%, 95% CI (76.8-100). We did not find a good level of agreement between both techniques: kappa value 0.55, 95% CI (0.36-0.75). CMV positivity with IHC was associated with the use of more than one immunosuppressant drug, OR 13.5, 95%CI (1.2-152.2). Antiviral treatment was useful for CMV patients with steroid-dependent and steroid-refractory IBD. CONCLUSIONS: IHC shows a 30% higher sensitivity than HE for the diagnosis of CMV infection in IBD patients. There is no good level of agreement between both histological techniques.


Assuntos
Infecções por Citomegalovirus/patologia , Adulto , Idoso , Biópsia/métodos , Estudos de Casos e Controles , Colo/patologia , Infecções por Citomegalovirus/complicações , Feminino , Humanos , Doenças Inflamatórias Intestinais/complicações , Masculino , Pessoa de Meia-Idade , Reto/patologia , Sensibilidade e Especificidade , Virologia/métodos
15.
Biophys J ; 93(5): 1474-83, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17483170

RESUMO

Recent experimental studies suggest that lactate dehydrogenase (LDH) binds its substrate via the formation of a LDH/NADH.substrate encounter complex through a select-fit mechanism, whereby only a minority population of LDH/NADH is binding-competent. In this study, we perform molecular dynamics calculations to explore the variations in structure accessible to the binary complex with a focus on identifying structures that seem likely to be binding-competent and which are in accord with the known experimental characterization of forming binding-competent species. We find that LDH/NADH samples quite a range of protein conformations within our 2.148 ns calculations, some of which yield quite facile access of solvent to the active site. The results suggest that the mobile loop of LDH is perhaps just partially open in these conformations and that multiple open conformations, yielding multiple binding pathways, are likely. These open conformations do not require large-scale unfolding/melting of the binary complex. Rather, open versus closed conformations are due to subtle protein and water rearrangements. Nevertheless, the large heat capacity change observed between binding-competent and binding-incompetent can be explained by changes in solvation and an internal rearrangement of hydrogen bonds. We speculate that such a strategy for binding may be necessary to get a ligand efficiently to a binding pocket that is located fairly deep within the protein's interior.


Assuntos
Biofísica/métodos , L-Lactato Desidrogenase/química , Músculos/enzimologia , Sítios de Ligação , Simulação por Computador , Cristalografia por Raios X , Bases de Dados de Proteínas , Humanos , Ligação de Hidrogênio , Ligantes , Músculos/metabolismo , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Solventes/química , Temperatura
16.
Gene Ther ; 14(2): 118-28, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16943855

RESUMO

The use of stem cells for reconstructive or neuroprotective strategies can benefit from new advances in neuroimaging techniques to track grafted cells. In the present work, we analyze the potential of a neural stem cell (NSC) line, which stably expresses the glial cell line-derived neurotrophic factor (GDNF) and the firefly luciferase gene (GDNF/Luc-NSC), for cell therapy in a Huntington's disease mouse model. Our results show that detection of light photons is an effective method to quantify the proliferation rate and to characterize the migration pathways of transplanted NSCs. Intravenous administration of luciferine, the luciferase substract, into the grafted animals allowed the detection of implanted cells in real time by an optical neuroimaging methodology, overpassing the limits of serial histological analyses. We observed that transplanted GDNF/Luc-NSCs survive after grafting and expand more when transplanted in quinolinate-lesioned nude mouse striata than when transplanted in non-lesioned mice. We also demonstrate that GDNF/Luc-NSCs prevent the degeneration of striatal neurons in the excitotoxic mouse model of Huntington's disease and reduce the amphetamine-induced rotational behavior in mice bearing unilateral lesions.


Assuntos
Corpo Estriado/patologia , Terapia Genética/métodos , Fator Neurotrófico Derivado de Linhagem de Célula Glial/uso terapêutico , Doença de Huntington/terapia , Fármacos Neuroprotetores/uso terapêutico , Transplante de Células-Tronco/métodos , Animais , Comportamento Animal/efeitos dos fármacos , Contagem de Células , Corpo Estriado/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Doença de Huntington/metabolismo , Doença de Huntington/patologia , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Luciferases/administração & dosagem , Camundongos , Camundongos Nus , Células-Tronco/metabolismo , Células-Tronco/patologia , Transdução Genética/métodos
17.
Philos Trans R Soc Lond B Biol Sci ; 361(1472): 1433-8, 2006 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-16873129

RESUMO

This manuscript describes ongoing research on the nature of chemical reactions in enzymes. We will investigate how protein dynamics can couple to chemical reaction in an enzyme. We first investigate in some detail why transition state theory cannot fully describe the dynamics of chemical reactions catalysed by enzymes. We describe quantum theories of chemical reaction in condensed phase including studies of how the symmetry of coupled vibrational modes differentially affects reaction dynamics. We make reference to previous work in our group on a variety of condensed phase chemical reactions (liquid and crystalline) and a variety of enzymatically catalysed reactions including the reactions of lactate dehydrogenase and purine nucleoside phosphorylase. All the protein motions we have studied have been quite rapid. We will propose methods to find motions over a broad range of time-scales in enzymes that couple to chemical catalysis. We report recent findings which show that conformational fluctuations in lactate dehydrogenase can strongly affect its ability to catalyse reactions through protein motion, and that only a tiny minority of conformations appear to be catalytically competent.


Assuntos
Enzimas/química , Modelos Químicos , Conformação Proteica , Catálise , L-Lactato Desidrogenase/química , Teoria Quântica
18.
Gastroenterol Hepatol ; 29(5): 297-8, 2006 May.
Artigo em Espanhol | MEDLINE | ID: mdl-16733036

RESUMO

We describe the case of a 20-year-old man who developed severe thrombocytopenia and hemorrhagic complications 5 months after beginning pegylated interferon therapy for chronic hepatitis C. Interferon therapy was stopped and platelets were transfused, but the platelet count did not increase until treatment with immunoglobulins and intravenous corticosteroids was started. Therefore, we believe this would suggest a possible autoimmune mechanism for the development of thrombocytopenia with interferon therapy. Mild reduction in platelets count is a common adverse effect of this drug. Nevertheless, severe decreases and secondary serious hemorrhagic complications have been infrequently described in the literature.


Assuntos
Antivirais/efeitos adversos , Hepatite C Crônica/tratamento farmacológico , Interferons/efeitos adversos , Polietilenoglicóis/efeitos adversos , Púrpura Trombocitopênica Idiopática/induzido quimicamente , Adulto , Antivirais/administração & dosagem , Antivirais/uso terapêutico , Terapia Combinada , Quimioterapia Combinada , Transtornos Hemorrágicos/etiologia , Hepatite C Crônica/complicações , Humanos , Imunoglobulinas Intravenosas , Interferons/administração & dosagem , Interferons/uso terapêutico , Masculino , Metilprednisolona/uso terapêutico , Transfusão de Plaquetas , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Púrpura Trombocitopênica Idiopática/terapia , Ribavirina/administração & dosagem , Ribavirina/uso terapêutico
19.
Clin Exp Allergy ; 35(8): 1003-13, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16120081

RESUMO

BACKGROUND: Allergen-induced T-helper type 2 (Th2) responses can be inhibited with Th1 directing vaccines. However, studies comparing the efficacy of the different adjuvants have not been performed in detail. OBJECTIVE: For this reason we compare the effects of live Bacillus-Calmette-Guerin(BCG), heat-killed (hk)-BCG, CpG-ODN (oligodeoxynucleotide) or PPD on the development of allergen-induced Th2 responses in mice. METHODS: Ovalbumin (OVA)-specific allergic responses were induced in C57BL/6 mice by two intraperitoneally (i.p.) applications of OVA/alum followed by the intranasal challenge with OVA. The different Th1-inducing adjuvants were applied to the mice together with OVA/alum i.p. during the OVA-sensitization period and, subsequently, different parameters of allergic immune responses were evaluated. RESULTS: All the adjuvants were effective in inhibiting the development of allergen-induced airway eosinophilia, mucous production and, with the exception of PPD, also airway hyper-reactivity, when they were applied together with OVA/alum. However, allergen-specific IgG1 and IgE serum levels were only reduced in live BCG- and PPD-treated mice. Suppression of airway eosinophilia was not observed in IFN-gamma- or IL-12-deficient mice (hk-BCG, CpG-ODN and PPD). Interestingly, live BCG was still able to suppress allergen-induced Th2 responses in the absence of either IFN-gamma or IL-12. When mice vaccinated with the different adjuvants together with OVA/alum were subjected to a second period of OVA/alum immunization, only live and hk-BCG were able to efficiently suppress the development of airway inflammation. This effect could be adoptively transferred by splenic CD4(+) T cells. CONCLUSIONS: Taken together our data suggest that live BCG>hk-BCG>CpG-ODN >PPD are effective in suppressing allergen-induced Th2 responses. The degree of suppression and the component of the Th2 response affected (airway inflammation vs. the production of allergen-specific IgE and IgG1) were dependent upon the adjuvant used and how it was applied. Our results contribute to the design of novel vaccines protecting humans from developing allergic disorders.


Assuntos
Alérgenos/imunologia , Células Th1/imunologia , Células Th2/imunologia , Vacinação/métodos , Adjuvantes Imunológicos , Transferência Adotiva/métodos , Animais , Vacina BCG/imunologia , Células Cultivadas , Eosinófilos/imunologia , Feminino , Tolerância Imunológica/imunologia , Imunoglobulina E/imunologia , Interferon gama/imunologia , Interleucina-12/imunologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/imunologia , Oligodesoxirribonucleotídeos/imunologia , Ovalbumina/imunologia , Sistema Respiratório/imunologia , Tuberculina/imunologia
20.
Gastroenterol Hepatol ; 25(8): 487-92, 2002 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-12361529

RESUMO

AIM: Short segments of intestinal metaplasia (IM) at the esophagogastric junction is an unclear entity. Several studies have reported wide variations in its prevalence and in the factors associated with its development. Recently, this entity has been divided into esophageal IM and cardiac IM, as two different lesions in etiopathogenesis and prognosis. We studied the prevalence of these conditions and their association with gastroesophageal reflux disease (GERD) and Helicobacter pylori infection. METHODS: In 161 patients, biopsies were obtained from the distal esophagus (2), just below the Z line (3), and in the gastric antrum (4). IM was diagnosed on the basis of staining of goblet cells with Alcian blue and was classified as esophageal if ILZ < IEG or cardiac ILZ = IEG. H. pylori was determined by rapid urease (CLO-test) and histology. Diagnosis of GERD was based on typical symptoms, endoscopy, and histology. In 54 patients with IM (73%) esophageal manometry and 24-hour pH-metry was also performed. RESULTS: IM was detected in 74 patients (46%); IM was esophageal in 33 patients (20.5%) and cardiac in 41 patients (25.4%). Patients with IM were significantly older than those without (p = 0.007) and took proton pump inhibitors more frequently (p = 0.004). No correlation was found between reflux symptoms, esophageal lesions or histological changes with either type of IM. No differences between esophageal or cardiac IM were detected by esophageal pH-metry. H. pylori infection was unrelated to cardiac IM, but these patients had a lower frequency of endoscopic and histological changes in the distal esophagus. CONCLUSIONS: Intestinal metaplasia is a common finding in patients sent for gastroscopy and is probably an acquired lesion that increases in prevalence with age. We found no associations between esophageal IM and GERD, evaluated by typical symptoms, endoscopic and histological changes and pH-metry. H. pylori infection showed no relation to cardiac IM.


Assuntos
Cárdia/patologia , Endoscopia do Sistema Digestório , Junção Esofagogástrica/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/análise , Comorbidade , Feminino , Determinação da Acidez Gástrica , Gastrite/diagnóstico , Gastrite/epidemiologia , Gastrite/microbiologia , Refluxo Gastroesofágico/epidemiologia , Refluxo Gastroesofágico/patologia , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/enzimologia , Helicobacter pylori/isolamento & purificação , Humanos , Intestino Delgado , Masculino , Manometria , Metaplasia , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Fatores de Risco , Espanha/epidemiologia , Coloração e Rotulagem , Urease/análise
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