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1.
J Appl Physiol (1985) ; 132(1): 187-198, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34855522

RESUMO

Simulated military operational stress (SMOS) provides a useful model to better understand resilience in humans as the stress associated with caloric restriction, sleep deficits, and fatiguing exertion degrades physical and cognitive performance. Habitual physical activity may confer resilience against these stressors by promoting favorable use-dependent neuroplasticity, but it is unclear how physical activity, resilience, and corticospinal excitability (CSE) relate during SMOS. To examine associations between corticospinal excitability, physical activity, and physical performance during SMOS. Fifty-three service members (age: 26 ± 5 yr, 13 women) completed a 5-day and -night intervention composed of familiarization, baseline, SMOS (2 nights/days), and recovery days. During SMOS, participants performed rigorous physical and cognitive activities while receiving half of normal sleep (two 2-h blocks) and caloric requirements. Lower and upper limb CSE were determined with transcranial magnetic stimulation (TMS) stimulus-response curves. Self-reported resilience, physical activity, military-specific physical performance (TMT), and endocrine factors were compared in individuals with high (HIGH) and low CSE based on a median split of lower limb CSE at baseline. HIGH had greater physical activity and better TMT performance throughout SMOS. Both groups maintained physical performance despite substantial psychophysiological stress. Physical activity, resilience, and TMT performance were directly associated with lower limb CSE. Individual differences in physical activity coincide with lower (but not upper) limb CSE. Such use-dependent corticospinal excitability directly relates to resilience and physical performance during SMOS. Future studies may use noninvasive neuromodulation to clarify the interplay among CSE, physical activity, and resilience and improve physical and cognitive performance.NEW & NOTEWORTHY We demonstrate that individual differences in physical activity levels coincide with lower limb corticospinal excitability. Such use-dependent corticospinal excitability directly relates to resilience and physical performance during a 5-day simulation of military operational stress with caloric restriction, sleep restriction and disruption, and heavy physical and cognitive exertion.


Assuntos
Militares , Córtex Motor , Adulto , Potencial Evocado Motor , Feminino , Humanos , Desempenho Físico Funcional , Tratos Piramidais , Estimulação Magnética Transcraniana , Adulto Jovem
2.
Adv Wound Care (New Rochelle) ; 8(11): 538-545, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31637100

RESUMO

Objective: There are no safety or absorption studies to guide topical timolol therapy for treatment of chronic wounds. This study was undertaken to address this gap. Approach: A prospective, observational, cross-sectional comparative study of timolol plasma levels in patients after topical administration to a chronic wound, compared with levels in patients after timolol ocular administration for the indication of glaucoma. Results: There was no statistically significant difference in the average plasma level of timolol in wound as compared with glaucoma patients. No bradycardia or wheezing was observed after administration. Innovation: We determined the single time point concentration of timolol in plasma 1 h after application of timolol 0.5% gel-forming solution to debrided chronic wounds, providing insight as to the safety of this emerging off-label treatment. Conclusion: The topical application of timolol for chronic wounds shares the same safety profile as the widely used application of ocular administration for glaucoma.

3.
Acta Medica Philippina ; : 289-299, 2017.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-959866

RESUMO

@#<p style="text-align: justify;"><strong>OBJECTIVES:</strong> Data is necessary for a hospital-wide cerebral palsy (CP) profile, this being the leading pediatric diagnosis at the PGH Rehabilitation Medicine Out Patient clinic. This study aims to identify clinical features, severity of disability and common interventions in pediatric CP patients.</p><p style="text-align: justify;"><strong>METHODS:</strong> CP profile data collection forms were accomplished from September 2014 to December 2015.</p><p style="text-align: justify;"><strong>PRIMARY RESULTS:</strong> Among 125 participants: 55% were < 5 years old, 47% were delivered vaginally, 42% had perinatal onset of condition, 34% had normal birth weight and 23% were moderately preterm. Most were quadriplegic (36%) and spastic (50%). Primary caregivers were mostly mothers (45%) and</p><p style="text-align: justify;"><strong>CONCLUSION:</strong> A hospital-wide cerebral palsy profile should be established to monitor CP, given its multifactorial cause and complex functional impact. Trends should be correlated with maternal and patient factors, healthcare provision and socioeconomics</p>


Assuntos
Humanos , Masculino , Feminino , Paralisia Cerebral , Destreza Motora
6.
Clin Ophthalmol ; 10: 1411-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27555747

RESUMO

PURPOSE: This study tested the feasibility of using an upright eyedrop bottle (UEB), a device designed to assist patients with eyedrop placement without reclining their head. PATIENTS AND METHODS: Experienced eyedrop users were enrolled who answered "yes" to the question, "Do you ever have trouble getting your eyedrops in?" After being shown a multimedia presentation and answering a questionnaire regarding eyedrop usage, participants were observed instilling eyedrops. Participants were instructed to instill a single eyedrop in each eye with both a standard bottle and the UEB. They repeated this process three times. With each trial, the amount of time taken to instill drops was recorded, as well as whether a drop landed in the eye (accuracy), if excess drops were used, and if the bottle tip was contaminated. RESULTS: Forty participants were enrolled, with an average age of 72.4±8.9 years; the majority were females (24 females). Thirty-four participants had been using eyedrops for at least 1 year. The time required to instill eyedrops was significantly less with the UEB in the second and third trials. There was no difference in accuracy between the conventional bottle and the UEB in the left or right eye in any trials. Significantly more participants used excess number of drops while using the conventional bottle in both the left and right eyes in all three trials. The bottle tip was never contaminated with the UEB. Depending on the trial and the eye, the conventional bottle was contaminated by between 42% and 53% of participants. CONCLUSION: The UEB has the potential to assist patients with eyedrop placement. Although there was no difference in accuracy between the UEB and the conventional bottle, the UEB was associated with less use of excess drops and less contamination of the bottle tip, compared to the conventional bottle.

7.
J Ophthalmol ; 2015: 329819, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25810920

RESUMO

Purpose. To examine financial and clinical work productivity outcomes associated with the use of the electronic health record (EHR). Methods. 191,360 billable clinical encounters were analyzed for 12 clinical providers over a 9-year study period during which an EHR was implemented. Main outcome measures were clinical revenues collected per provider and secondary outcomes were charge capture, patient visit coding levels, transcription costs, patient visit volume per provider, digital drawing, and digital imaging volume. Results. The difference in inflation adjusted net clinical revenue per provider per year did not change significantly in the period after EHR implementation (mean = $404,198; SD = $17,912) than before (mean = $411,420; SD = $39,366) (P = 0.746). Charge capture, the proportion of higher- and lower-level visit codes for new and established patients, and patient visits per provider remained stable. A total savings of $188,951 in transcription costs occurred over a 4-year time period post-EHR implementation. The rate of drawing the ophthalmic exam in the EHR was low (mean = 2.28%; SD = 0.05%) for all providers. Conclusions. This study did not show a clear financial gain after EHR implementation in an academic ophthalmology practice. Ophthalmologists do not rely on drawings to document the ophthalmic exam; instead, the ophthalmic exam becomes text-driven in a paperless world.

8.
J Cancer Res Ther ; 8(3): 451-3, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23174735

RESUMO

Amelanotic melanoma is a rare malignancy and the prognosis is usually poorer than that of pigmented melanomas, because of delay in establishing the correct diagnosis, and in treatment initiation. In our case report, we present a the Flurodeoxyglocose Positron Emission Tomography-Computed Tomography (FDG PET/CT) findings of a patient suffering from malignant amelanotic melanoma and its histopathological confirmation and immunohistochemistry (IHC) correlation In the described case, amelanotic melanoma masqueraded as adenocarcinoma of the rectum in the pathology as well the clinical course. Our case highlights the importance of obtaining a tissue diagnosis and IHC confirmation whenever unusual PET/CT findings are encountered.


Assuntos
Imuno-Histoquímica/métodos , Melanoma Amelanótico/diagnóstico , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons , Neoplasias Cutâneas/diagnóstico , Tomografia Computadorizada por Raios X , Adenocarcinoma/diagnóstico , Diagnóstico Diferencial , Fluordesoxiglucose F18 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Masculino , Melanoma Amelanótico/diagnóstico por imagem , Melanoma Amelanótico/cirurgia , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos , Pele/patologia , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/cirurgia
9.
J Ophthalmol ; 2012: 430249, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22315660

RESUMO

Purpose. To compare anterior chamber depth (ACD), representing the distance between the anterior corneal surface and anterior lens surface measurements between the Galilei Dual Scheimpflug Analyzer and the IOLMaster. Methods. A retrospective review of 65 individual patient eyes with normal anterior segments, and no prior ocular surgery was performed. Patients underwent ACD measurements with both devices during the same session by a trained examiner. Interdevice agreement was evaluated using paired two-tailed t-tests, Pearson correlation coefficient, and Bland-Altman analysis. Results. The mean ± standard deviation (SD) ACD for the Galilei and IOLMaster was 3.37 ± 0.36 mm (range from 2.62 to 4.13) and 3.25 ± 0.38 mm (range from 2.34 to 3.92), respectively (Pearson correlation coefficient = 0.96). ACD mean difference was 0.12 mm (P < 0.0001); 95% limits of agreement was from -0.09 to 0.34. The Galilei measured slightly longer ACD values than the IOLMaster. There was no relationship between axial length and interdevice difference. Conclusion. ACD measurements correlate well between the Galilei and IOLMaster, with Galilei values on average 0.12 mm longer than the IOLMaster.

10.
Surv Ophthalmol ; 57(4): 379-85, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22018677

RESUMO

A 60-year-old man presented with diplopia and neurocognitive deficits, which progressed rapidly over several months. Magnetic resonance imaging of the head revealed bilateral signal abnormalities and diffusion-weighted imaging restriction in bilateral basal ganglia, thalami, mesial temporal regions, and periaqueductal gray matter. Cerebrospinal fluid analysis was positive for 14-3-3 and tau proteins. The patient developed progressive neurocognitive decline followed by sleep disturbance and myoclonic jerking consistent with probable Creutzfeldt-Jakob disease.


Assuntos
Síndrome de Creutzfeldt-Jakob/diagnóstico , Proteínas 14-3-3/líquido cefalorraquidiano , Gânglios da Base/patologia , Transtornos Cognitivos/diagnóstico , Síndrome de Creutzfeldt-Jakob/líquido cefalorraquidiano , Diplopia/diagnóstico , Eletroencefalografia , Evolução Fatal , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Substância Cinzenta Periaquedutal/patologia , Tálamo/patologia , Proteínas tau/líquido cefalorraquidiano
11.
Nutr Metab Cardiovasc Dis ; 18(3): 227-32, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17400434

RESUMO

BACKGROUND AND AIM: Soluble P-selectin (sP-sel) represents a marker of platelet activation. This study was addressed to investigate the associations of sP-sel plasma levels with anthropometric parameters, insulin resistance, and related metabolic and prothrombotic factors. METHODS AND RESULTS: 50 non-diabetic women, 17 with normal weight and 33 overweight and obese, aged 18-55 years, were examined. Measurements included body mass index (BMI), central fat accumulation (evaluated by waist circumference), systolic and diastolic blood pressure levels, fasting plasma concentrations of sP-sel, glucose, lipids (triglycerides, total cholesterol and HDL-cholesterol), insulin, and prothrombotic factors (plasminogen activator inhibitor-1, von Willebrand factor, fibrinogen), and insulin resistance (estimated by the homeostasis model assessment: HOMA(IR)). Overweight and obese women had higher fasting plasma sP-sel concentrations compared to normal-weight controls (P<0.05). sP-sel concentrations were positively correlated with BMI, HOMA(IR), systolic and diastolic blood pressure, fasting insulin, triglyceride and PAI-1 plasma levels (P<0.05 for all the correlations). When a multiple regression analysis was performed, with P-sel as dependent variable and all the other parameters as independent variables, P-sel did not maintain a significant relationship with any of these variables. CONCLUSIONS: s-P-selectin plasma concentrations are higher in overweight and obese insulin resistant subjects, thus possibly contributing to the cardiovascular risk of these patients. However, body fatness and insulin resistance are not independent determinants of fasting plasma sP-sel concentrations.


Assuntos
Glicemia/metabolismo , Resistência à Insulina , Lipídeos/sangue , Obesidade/sangue , Selectina-P/sangue , Adolescente , Adulto , Antropometria , Índice de Massa Corporal , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/epidemiologia , Estudos de Casos e Controles , Feminino , Fibrinogênio/análise , Humanos , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/sangue , Ativação Plaquetária , Análise de Regressão , Fatores de Risco , Solubilidade , Fator de von Willebrand/análise
12.
J Endocrinol Invest ; 30(5): 399-403, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17598972

RESUMO

BACKGROUND: Obesity is associated with a chronic low-grade inflammatory condition. Haptoglobin is a glycoprotein involved in the acute-phase response to inflammation, and it is increased in obese subjects. The possibility that hyperinsulinemia and/or insulin resistance may directly increase haptoglobin levels has never been tested. The aim of this study was to investigate the associations of haptoglobin serum levels with anthropometric parameters, insulin levels, insulin resistance and related metabolic variables in overweight and obese women. PATIENTS AND METHODS: This is a cross-sectional study of 194 non-diabetic overweight and obese subjects, aged 18-68 yr. Measurements included body mass index (BMI), central fat accumulation [evaluated by waist circumference (WC)], systolic and diastolic blood pressure, and fasting concentrations of haptoglobin, insulin, glucose, lipids (triglycerides, total cholesterol, and HDL-cholesterol), and insulin resistance as estimated by the homeostasis model assessment (HOMAIR). RESULTS: Haptoglobin serum levels showed a positive association with BMI (p<0.001), WC (p<0.001), HOMAIR (p<0.001), and fasting insulin (p<0.001), triglyceride (p<0.001) and glucose (p<0.05) blood levels. However, only insulin maintained a significant independent association with haptoglobin (p<0.001) when a multiple regression analysis was performed and age, BMI (or WC), blood pressure levels, HOMAIR, and fasting insulin, glucose, and lipid blood concentrations were entered as independent variables. CONCLUSIONS: Higher haptoglobin serum levels seem to be a strong marker of hyperinsulinemia, independently of BMI, body fat distribution, insulin resistance and related parameters.


Assuntos
Biomarcadores/sangue , Haptoglobinas/metabolismo , Hiperinsulinismo/sangue , Obesidade/sangue , Adolescente , Adulto , Idoso , Pressão Sanguínea , Índice de Massa Corporal , Peso Corporal , Estudos Transversais , Feminino , Humanos , Hiperinsulinismo/complicações , Pessoa de Meia-Idade , Obesidade/complicações
13.
Emergencias (St. Vicenç dels Horts) ; 14(1): 36-38, feb. 2002. ilus
Artigo em Es | IBECS | ID: ibc-22066

RESUMO

La colocación de catéteres venosos centrales insertados periféricamente (CVCIP) permite obtener un acceso venoso central evitando las complicaciones asociadas a las punciones de los grandes troncos venosos (neumotórax, hemotórax y punción de grandes vasos arteriales). Aunque se conoce que la inserción de un CVCIP puede producir arritmias cardíacas al contactar la punta del catéter con el tejido cardíaco, apenas existen en la literatura descripciones de arritmias relacionadas con la posición del cuerpo. Se describen dos casos de taquicardias ventriculares posturales secundarias a la colocación de un CVCIP (AU)


Assuntos
Idoso , Masculino , Pessoa de Meia-Idade , Humanos , Taquicardia Ventricular/etiologia , Cateterismo Venoso Central/efeitos adversos , Esofagite/complicações , Obstrução Uretral/complicações
14.
Nutr Metab Cardiovasc Dis ; 12(5): 297-305, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12616810

RESUMO

BACKGROUND AND AIM: Evidence for apoptosis has been found in advanced atherosclerotic lesions, but the factors triggering it are poorly understood. Oxidised low-density lipoproteins (LDLs) are cytotoxic to a variety of cells and induce the apoptosis of smooth muscle cells (SMC), fibroblast, macrophages and endothelial cells in vitro. The aim of this study was to investigate apoptotic cell death in the early phases of aortic atherosclerosis in rabbits, and whether oxidised LDLs colocalize ex vivo with apoptotic cells in atherosclerotic lesions in cholesterol-fed rabbits. METHODS AND RESULTS: Male albino New Zealand rabbits were fed a standard diet or a diet containing 1.2% cholesterol for 60 days. The aortic arch of each animal was sectioned and stained with antibodies against SMC, endothelial cells, macrophages and oxidised LDLs or for proteins involved in apoptotic pathways such as Fas, Bax, Bcl2, and caspase 3. The nuclei in adjacent sections were stained with Hoechst 33258, TUNEL and for the proliferating cell nuclear antigen (PCNA). Early atherosclerotic lesions were characterised by intimal thickening and the presence of SMC and macrophages. The percentage of apoptotic cells, calculated as the ratio of TUNEL-positive nuclei to total nuclei was 32.6 +/- 3.73% in the lesions and 55.9 +/- 2.36% in the endothelium. As it has been reported that nuclei undergoing active gene transcription can be TUNEL positive, we evaluated the percentage of PCNA-positive cells, which proved to be 45.2 +/- 4.68% along the endothelium and 22.3 +/- 2.7% in the intima. The true percentage of apoptotic cells was therefore about 10% in both cases. Fas, Bax and caspase3 signals were mainly located in the endothelium and SMC proximal to the lumen, whereas Bcl2 colocalized with macrophages and SMC deeper in the lesions. Abundant oxidised LDL epitopes were detected in areas of lipid accumulation and along the endothelium, mainly in the areas in which TUNEL and PCNA-positive cells were localised. CONCLUSIONS: Our findings may be taken as ex vivo indications of an apoptotic and proliferating role of oxidised LDLs as previously shown in vitro, and may at least partially account for the endothelial dysfunction that can be rapidly induced by hypercholesterolemia.


Assuntos
Apoptose , Colesterol na Dieta/administração & dosagem , Doença da Artéria Coronariana/metabolismo , Endotélio Vascular/citologia , Lipoproteínas LDL/fisiologia , Animais , Anticorpos Monoclonais , Doença da Artéria Coronariana/patologia , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Lipoproteínas LDL/metabolismo , Macrófagos/imunologia , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Músculo Liso Vascular/citologia , Músculo Liso Vascular/imunologia , Músculo Liso Vascular/patologia , Oxirredução , Coelhos
15.
Clin Chem Lab Med ; 38(2): 155-60, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10834403

RESUMO

Endothelium is an early target of pro-atherosclerotic events, which may result in functional and morphological perturbations. Oxidized low density lipoproteins, an atherogenic factor with strong cytotoxicity, may potentially contribute to altered endothelial function through the activation of a stress response, which would rescue cells to full vitality, or, conversely, by leading to cell death. Evidence is presented here for the ability of chemically oxidized low density lipoproteins to induce the synthesis of the inducible form of heat shock protein 70 in cultured human endothelial cells, and for the association of epitopes of these modified lipoproteins with apoptotic endothelial cells in aortic sections from hypercholesterolemic rabbits.


Assuntos
Endotélio Vascular/metabolismo , Lipoproteínas LDL/metabolismo , Animais , Apoptose , Arteriosclerose/etiologia , Arteriosclerose/metabolismo , Arteriosclerose/patologia , Células Cultivadas , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Proteínas de Choque Térmico HSP70/biossíntese , Humanos , Hipercolesterolemia/metabolismo , Hipercolesterolemia/patologia , Técnicas In Vitro , Lipoproteínas LDL/farmacologia , Masculino , Oxirredução , Coelhos , Sinvastatina/farmacologia
17.
FEBS Lett ; 462(1-2): 113-6, 1999 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-10580102

RESUMO

Oxidized low density lipoprotein (OxLDL) possesses several proatherogenic characteristics, among which a marked cytotoxicity. In vitro, cytotoxicity of OxLDL to endothelial cells is associated with an increase in the expression of the inducible form of heat shock protein 70 (hsp70), generally regarded as a cytoprotective protein. Oxidized derivatives of cholesterol which form upon LDL oxidation are cytotoxic. Moreover, most of the OxLDL cytotoxicity is due to its lipid moiety, in particular to oxysterols. In this report we demonstrate that although oxysterols identified in OxLDL are cytotoxic, they cannot trigger the increase in hsp70 expression observed with intact oxidized lipoproteins. We speculate therefore that oxysterols may represent the most toxic form of oxidized lipids in LDL because they cannot activate a rescue mechanism (i.e. the hsp response) and may contribute significantly to cell death within atherosclerotic plaques.


Assuntos
Endotélio Vascular/metabolismo , Proteínas de Choque Térmico HSP70/biossíntese , Lipoproteínas LDL/metabolismo , Apoptose , Endotélio Vascular/patologia , Expressão Gênica , Humanos , Hidroxicolesteróis/metabolismo , Técnicas In Vitro , Cetocolesteróis/metabolismo , Oxirredução
18.
Atherosclerosis ; 141(1): 45-51, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9863537

RESUMO

The in vivo direct antiatherogenic activity of the antioxidant probucol (200 mg/kg per day) or the beta-blocker with antioxidant properties carvedilol (10 and 20 mg/kg per day) was tested in the same animal in two different types of atherosclerotic lesion (proliferative and fatty lesions) induced in cholesterol-fed rabbits (1%). Drugs were given daily mixed with standard diet for 8 weeks; body weight and plasma lipid profile were not different among groups throughout the study. Aortic fatty lesions were induced by cholesterol feeding (n = 25 in each group) and their extent expressed as % of aorta inner surface covered by plaques was significantly reduced by both drugs (28.2+/-9.6%, P <0.05, 19.9+/-6.2%, P <0.01 for low- and high-dose carvedilol, respectively; 22.3+/-7.6%, P <0.01 for probucol, versus 41.6+/-10.7% in control rabbits). Proliferative lesions were obtained by positioning a hollow silastic collar around one carotid artery 6 weeks after dietary and drug treatments started (n = 5 in each group). The neointimal formation, mostly composed by myocytes, was determined by measuring cross-sectional thickness ratio of intimal (I) and medial (M) tissue of fixed arteries. In untreated animals, collared arteries resulted in a significant neointimal cell accumulation compared to the sham (1.10+/-0.14 versus 0.02+/-0.01) without change in medial thickness. I/M ratio was reduced by about 50% in animals treated with probucol (0.51+/-0.1) and carvedilol (0.66+/-0.21 and 0.52+/-0.1 in the low- and high-dose group, respectively). Total plasma TBARS were more than 50% lower in both probucol- and high-dose carvedilol-treated rabbits. Results show that pharmacological pretreatment with antioxidants directly inhibits early atherogenic processes, representing a potentially useful approach in the prevention of atherosclerosis.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Anticolesterolemiantes/farmacologia , Antioxidantes/farmacologia , Artérias/patologia , Arteriosclerose/patologia , Carbazóis/farmacologia , Hipercolesterolemia/patologia , Probucol/farmacologia , Propanolaminas/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Aorta/patologia , Arteriosclerose/complicações , Arteriosclerose/prevenção & controle , Artérias Carótidas/patologia , Carvedilol , Divisão Celular , Hipercolesterolemia/complicações , Masculino , Coelhos , Túnica Íntima/patologia , Túnica Média/patologia
19.
Atherosclerosis ; 127(2): 147-54, 1996 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-9125304

RESUMO

Several cytotoxic stimuli of a different nature are involved in the complex etiology of atherosclerosis. Cells of the vasculature may potentially cope with the presence of these stressors through the increased synthesis of stress proteins (or heat shock proteins, hsps), an ubiquitous and conserved defense response. Evidence exists that the expression of two stress proteins of intermediate molecular weight, hsp60 and hsp70, is higher at sites of atherosclerotic lesions than it is in normal tissue. The role of hsps in atherosclerosis is controversial. While hsp70 is likely to be involved in cytoprotection, hsp60 is probably acting as an autoantigen, and may trigger both cell-mediated and antibody-mediated immune responses.


Assuntos
Arteriosclerose , Proteínas de Choque Térmico/fisiologia , Animais , Arteriosclerose/etiologia , Arteriosclerose/imunologia , Arteriosclerose/metabolismo , Chaperonina 60/fisiologia , Proteínas de Choque Térmico HSP70/fisiologia , Humanos , Fatores de Risco
20.
Arterioscler Thromb Vasc Biol ; 16(9): 1104-11, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8792763

RESUMO

Oxidized LDL (OxLDL), a causal factor in atherosclerosis, is cytotoxic and triggers the expression of various heat shock proteins (hsps), among which is hsp70, in cultured animal and human cells. hsps constitutively act as molecular chaperones and in situations of stress protect other cellular proteins from potential denaturation caused by cytotoxic stimuli. The sensitivity of endothelial cells to OxLDL toxicity and accordingly the level of hsp70 expression depend on cell density. While confluent cells were relatively resistant to OxLDL toxicity and were not induced to express hsp70 when challenged with the lipoprotein (up to 800 micrograms/mL), sparse cells exhibited a concentration- and time-dependent expression of inducible hsp70, which increased up to fivefold to sixfold in unchallenged cells. Neither the activity of receptors recognizing OxLDL nor potentially protective cell products affected the stress response. Rather, we demonstrated that cell proliferation, which is high for sparse cultures and wound-healing monolayers, is responsible for these observations. We also demonstrated that the lipid moiety of OxLDL essentially accounts for the hsp-inducing effect of the lipoprotein. OxLDL has been detected in atherosclerotic lesions, which also show an increase of immunoreactive hsp72/73. We speculate that, in vivo, rapidly growing cells, such as those of lesion-prone areas, are more sensitive to the toxicity of OxLDL than are quiescent cells and that an increased expression of hsp70 may allow proliferating cells an increased chance of survival.


Assuntos
Endotélio Vascular/metabolismo , Proteínas de Choque Térmico HSP70/biossíntese , Lipoproteínas LDL/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Peroxidação de Lipídeos , Lipoproteínas LDL/metabolismo
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