Childhood Hearing Health: Educating for Prevention of Hearing Loss

Introduction The presence of noise in our society has attracted the attention of health professionals, including speech-language pathologists, who have been charged along with educators with developing hearing conservation programs in schools. Objective To describe the results of three strategies for awareness and hearing preservation in first to fourth grades in public elementary schools. Methods The level of environmental noise in classrooms was assessed, and 638 elementary school students from first to fourth grades, 5 to 10 years of age, were audiologically evaluated. After the evaluations, educational activities were presented to children and educators. Results The noise level in the classroom ranged from 71.8 to 94.8 A-weighted decibels. The environment of the classroom was found to promote sound reverberation, which hinders communication. Thirty-two students (5.1%) presented hearing alterations. Conclusion The application of strategies for a hearing conservation program at the school showed that noise is present in the room, and hearing loss, sometimes silent, affects schoolchildren. Students and teachers were aware that hearing problems can be prevented. Avoiding exposure to noise and improving the acoustics in classrooms are essential. .

Expression of TNF-α and IL-6 cytokines in the choroid and sclera of hypercholesterolemic rabbits / Expressão das citocinas TNF-α and IL-6 na coroide e esclera de coelhos hipercolesterolêmicos

Purpose: This study aimed to evaluate the expression of the inflammatory cytokines TNF-α and IL-6 in the sclera and choroid of hypercholesterolemic rabbits. Method: Twenty-one New Zealand male albino rabbits were divided into two groups: NG and HG. The NG group was fed a standard rabbit diet and the HG group was fed a cholesterol-enriched diet (1%). The serum total cholesterol, triglyceride, HDL cholesterol, and fasting blood glucose levels were determined at the beginning of the experiment and on the day of euthanasia. Euthanasia of animals in the NG and HG groups was performed at the end of the 4th and 8th week, respectively. The eyes were analyzed immunohistochemically using TNF-α and IL-6 antibodies. Results: At the time of euthanasia, the HG group showed a significant increase in total cholesterol and triglyceride when compared with the NG group (p<0.001). When compared with the NG group, there was a significant increase in the expression of TNF-α (p<0.001) and IL-6 (p=0.002) in the choroid and sclera of animals in the HG group. Conclusion: This study demonstrates that the hypercholesterolemic diet induces expression of TNF-α and IL-6 in the choroid and sclera of rabbits. .

Objetivo: Avaliar a expressão das citocinas inflamatórias TNF-α e IL-6 na esclera e coroide de coelhos hipercolesterolêmicos. Método: Coelhos New Zealand foram organizados em dois grupos: GN recebeu ração padrão para coelhos; GH recebeu dieta rica em colesterol a 1%. Foi realizada a dosagem sérica de colesterol total, triglicerídeos, HDL colesterol, glicemia de jejum no início do experimento e no momento da eutanásia. Ao final da 4ª semana para o GN e 8ª semana para o GH foi realizada a eutanásia dos animais. Os olhos foram submetidos à análise imuno-histoquímica com os anticorpos TNF-α e IL-6. Resultados: O GH manifestou significativo aumento do colesterol total e triglicerídeos em relação ao GN (p<0,001). Houve significativo aumento da expressão da TNF-α (p<0,001) e da IL-6 (p=0,002) na coroide e esclera dos animais do GH em relação ao GN. Conclusão: Este estudo demonstra que a dieta hipercolesterolêmica induz ao aumento da expressão das citocinas TNF-α e IL-6 na coroide e esclera de coelhos. .

Selected spices and their combination modulate hypercholesterolemia-induced oxidative stress in experimental rats

BACKGROUND: Effect of aqueous extracts of Allium sativum (garlic), Zingiber officinale (ginger), Capsicum fructensces (cayenne pepper) and their mixture on oxidative stress in rats fed high Cholesterol/high fat diet was investigated. Rats were randomly distributed into six groups (n = 6) and given different dietary/spice treatments. Group 1 standard rat chow (control), group 2, hypercholesterolemic diet plus water, and groups 3, 4, 5, 6, hypercholesterolemic diet with 0.5 ml 200 mg · kg-1 aqueous extracts of garlic, ginger, cayenne pepper or their mixture respectively daily for 4 weeks. RESULTS: Pronounced oxidative stress in the hypercholesterolemic rats evidenced by significant (p < 0.05) increase in MDA levels, and suppression of the antioxidant enzymes system in rat's liver, kidney, heart and brain tissues was observed. Extracts of spices singly or combined administered at 200 mg.kg-1 body weight significantly (p < 0.05) reduced MDA levels and restored activities of antioxidant enzymes. CONCLUSIONS: It is concluded that consumption of garlic, ginger, pepper, or their mixture may help to modulate oxidative stress caused by hypercholesterolemia in rats.

Respuestas metabólicas inducidas por ejercicio físico de alta intensidad en mujeres sedentarias con glicemia basal alterada e hipercolesterolemia / Metabolic response to high intensity exercise training in sedentary hyperglycemic and hypercholesterolemic women

Background: High intensity training could be an effective way of improving health on individuals at high metabolic risk. Aim: To investigate the effects of a high intensity training intervention on metabolic-related markers in sedentary women at high metabolic risk. Material and Methods: Forty six sedentary women with a body mass index (BMI) over 25 kg/m² were assigned to four groups, according to their metabolic profile; hyperglycemia (H, n = 12), hyperglycemia/hypercholesterolemia (HH, n = 13), normoglycemia (N, n = 10) and normoglycemia/hypercholesterolemia (NH, n = 11). For 12 weeks and five days per week, subjects performed seven intervals of high intensity training (20 to 30 seconds) during a training session of 20 minutes. Anthropometric (body weight, body mass index (BMI), waist circumference) and metabolic variables (glucose, total cholesterol, LDL, HDL and TG) were measured at baseline, at 6 and 12 weeks of intervention. Results: BMI and waist circumference decreased significantly after 12 weeks of intervention. Similarly, glucose decreased significantly after 12 weeks of intervention in all groups. The reduction was of higher magnitude in those groups with hyperglycemia (H = -16%, HH = -22%, N = -7,5%, NH = -9,6%). However, lipid profile (TG, total cholesterol, LDL and HDL) improved significantly only in the hypercholesterolemic groups. Conclusions: Physical activity programs incorporating high intensity training can improve glucose and lipid profile in women with metabolic disorders. Moreover, this benefit is greatest in those individuals with highest metabolic burden.

Protective effect of eicosapentaenoic acid-docosahexaenoic acid and α–linolenic acid rich phytosterol ester on brain antioxidant status and brain lipid composition in hypercholesterolemic rats.

With a view to investigate the ameliorative effects of sitosterol esters against degenerative effects of hypercholesterolemia brain antioxidant enzyme assays, brain lipid profile, brain phospholipid compositional change and brain neurotransmitter concentrates (glutamic acid, asparctic acid, glycine) were measured in hypercholesterolemic rats. The results indicated that phytosterol esters have a role in countering hypercholesterolemia-related changes in the brain by decreasing the cholesterol levels, increasing the phospholipid levels and increasing the level of antioxidant enzymes. The results suggest that phytosterol esters may be of therapeutic significance and may offer new and effective options for the treatment of hypercholesterolemia-induced changes in the brain.

Aumento da imunorreatividade ao VEGFR-1 no complexo coroido-escleral em modelo experimental de hipercolesterolemia / Increased VEGFR-1 immunoreactivity in the choroid-scleral complex in hypercholesterolemia experimental model

OBJETIVO: O objetivo deste trabalho é investigar a expressão do fator de crescimento vascular endotelial (VEGF) na coroide e esclera, utilizando um modelo experimental de hipercolesterolemia. MÉTODO: Coelhos New Zealand foram organizados em dois grupos: O grupo dieta normal (GN), composto por 8 coelhos (8 olhos), recebeu ração padrão para coelhos, durante 4 semanas; e o grupo hipercolesterolêmico (GH), composto por 13 coelhos (13 olhos), recebeu dieta rica em colesterol a 1% por 8 semanas. Foi realizada a dosagem sérica de colesterol total, triglicerídeos, HDL colesterol, glicemia de jejum no início do experimento e no momento da eutanásia. Ao final da 8ª semana para o GH e 4ª semana para o GN foi realizada a eutanásia dos animais e os olhos foram submetidos à análise imuno-histoquímica com os anticorpos RAM-11 e VEGFR-1. RESULTADOS: Observou-se significativo aumento do colesterol total e triglicerídeos do GH em relação ao GN (p<0,001). Houve significativo aumento da expressão da RAM-11 e VEGFR-1 na coroide e esclera dos animais do GH em relação ao GN (p<0,001). CONCLUSÃO: Este estudo demonstra que a dieta hipercolesterolêmica em coelhos induz ao aumento da concentração de macrófagos e da imunorreatividade ao VEGFR-1 na coroide e esclera, expressando similaridade com a degeneração macular relacionada à idade (DMRI) humana.

PURPOSE: The aim of this study is to investigate the expression of vascular endothelial growth factor (VEGF) in the choroid and sclera using hypercholesterolemia experimental model. METHODS: New Zealand rabbits were divided into two groups: 8 rabbits (8 eyes), in the normal diet group (NG), were fed by a standard diet for 4 weeks; and 13 rabbits (13 eyes), in the hypercholesterolemic group (HG), were fed by a 1% cholesterol-enriched diet for 8 weeks. Total serum cholesterol, triglyceride, HDL cholesterol and fasting blood glucose exams were performed at the initiation of the experiment and at the euthanasia time. After hypercholesterolemic group 8th week and NG 4th week, animals were euthanized and their eyes underwent immunohistochemical analysis with the RAM-11 and VEGFR-1). RESULTS: The diet has induced a significant increase in total cholesterol and triglyceride levels in HG when compared with NG (p<0.001). There was a significant increase in the RAM-11 and VEGFR-1 expressions in hypercholesterolemic group choroid and sclera in relation to NG (p<0,001). CONCLUSION: This study has revealed that the hypercholesterolemic diet in rabbits induces an increase in the macrophage concentration and immunoreactivity to VEGFR-1 in the choroid and sclera, resembling human age-related macular degeneration (ARMD).

Aumento da expressão do MCP-1 coroidal e escleral em modelo experimental de hipercolesterolemia / Increase of choroidal and scleral MCP-1 expression in hypercholesterolemia experimental model

OBJETIVO: O objetivo deste trabalho é demonstrar experimentalmente que a dieta rica em colesterol provoca aumento da expressão da MCP-1 na coroide e esclera. MÉTODO: Coelhos New Zealand foram organizados em dois grupos: GN (grupo dieta normal), composto por 8 coelhos (8 olhos), recebeu ração padrão para coelhos, durante 4 semanas; GH (grupo hipercolesterolêmico), composto por 13 coelhos (13 olhos), recebeu dieta rica em colesterol a 1% por 8 semanas. Foi realizada a dosagem sérica de colesterol total, triglicerídeos, HDL colesterol, glicemia de jejum no início do experimento e no momento da eutanásia. Ao final da 8ª semana para o GH e 4ª semana para o GN foi realizada a eutanásia dos animais e os olhos foram submetidos à análise imuno-histoquímica com o anticorpo anti-MCP-1. RESULTADOS: A dieta provocou significativo aumento do colesterol total e triglicerídeos do GH em relação ao GN (p<0,001). Houve significativo aumento da expressão da MCP-1 na coroide e esclera dos animais do GH em relação ao GN (p<0,001). CONCLUSÃO: Este estudo demonstrou que a dieta hipercolesterolêmica em coelhos induz ao aumento da expressão do MCP-1 na coroide e esclera.

PURPOSE: The aim of this study is to experientially demonstrate that a cholesterol-enriched diet induces an increase in the MCP-1 expression in the choroid and sclera. METHOD: New Zealand rabbits were divided into two groups: GN (normal diet group) of 8 rabbits (8 eyes) was fed a standard rabbit diet for 4 weeks; GH (hypercholesterolemic group) of 13 rabbits (13 eyes) was fed a 1% cholesterol enriched diet for 8 weeks. Total serum cholesterol, triglyceride, HDL cholesterol and fasting blood glucose exams were performed at the start of the experiment and at the euthanasia time. After GH 8th week and GN 4th week animals were euthanized and their eyes underwent immunohistochemical analysis with the anti-MCP-1 antibody. RESULTS: The diet has induced a significant increase in GH total cholesterol and triglyceride levels when compared with NG (p<0.001). There was a significant increase in the MCP-1 expression in GH choroid and sclera in relation to GN (p<0.001). CONCLUSION: This study has revealed that the hypercholesterolemic diet in rabbits induces an increase in the MCP-1 expression in the choroid and sclera.

Resveratrol provoca efeitos antiaterogênicos em um modelo animal de aterosclerose / Resveratrol causes antiatherogenic effects in an animal model of atherosclerosis

FUNDAMENTO: O resveratrol protege o sistema cardiovascular por meio de uma série de mecanismos, incluindo atividades antioxidantes e antiplaquetárias. OBJETIVO: Avaliar os possíveis efeitos anti-inflamatórios e antiaterogênicos do resveratrol, utilizando coelhos alimentados com uma dieta hipercolesterolêmica (1 por cento de colesterol). MÉTODOS: Vinte coelhos brancos adultos do sexo masculino foram selecionados e divididos em dois grupos: grupo controle (GC), 10 coelhos; e grupo resveratrol (GR), 10 coelhos. Os animais foram alimentados com uma dieta hipercolesterolêmica por 56 dias. Para a dieta do GR, o resveratrol (2mg/kg peso/dia) foi adicionado do 33º ao 56º dia. RESULTADOS: Não houve diferença significativa entre os grupos no colesterol sérico total, no colesterol HDL, no colesterol LDL e nos triglicerídeos. No GC, 70 por cento apresentaram lesões ateroscleróticas avançadas da aorta (tipos III, IV, V ou VI). Todos os animais do GR apresentaram lesões ateroscleróticas leves da aorta (tipos I ou II) ou não apresentaram lesões. A razão entre a área intimal e a área da camada intimal/medial mostrou-se significativamente menor no GR quando comparada ao GC (p < 0,001). Áreas positivas para moléculas de adesão celular vascular-1 (VCAM-1) foram menores no GR (p = 0,007). As concentrações de proteína quimiotática de monócitos-1 (MCP-1) e de interleucina-6 (IL-6) mostraram-se significativamente menores no GR do que no GC (p = 0,039 e p = 0,015, respectivamente). CONCLUSÃO: O Resveratrol apresentou importantes efeitos antiaterogênicos e anti-inflamatórios em um modelo animal com coelhos alimentados com uma dieta hipercolesterolêmica.

BACKGROUND: Resveratrol protects the cardiovascular system by a number of mechanisms, including antioxidant and anti-platelet activities. OBJECTIVE: To assess the potential anti-inflammatory and antiatherogenic effects of resveratrol using rabbits fed a hypercholesterolemic diet (1 percent cholesterol). METHODS: Twenty white male rabbits were selected and divided into two groups: control group (CG), 10 rabbits; and resveratrol group (RG), 10 rabbits. The animals were fed a hypercholesterolemic diet for 56 days. For the RG diet, resveratrol (2mg/kg weight/day) was added from days 33 - 56. RESULTS: There was no significant difference in the total serum cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides between the groups. Of the CG, 70 percent had advanced aortic atherosclerotic lesions (types III, IV, V, or VI). All animals from the RG had mild aortic atherosclerotic lesions (types I or II, or no lesions). The intima area and the intima/media layer area ratio was significantly lower in the RG as compared to the CG (p<0.001). Positive areas for VCAM-1 molecules were lower in the RG (p=0.007). The MCP-1 and IL-6 concentrations were lower in the RG than the CG (p=0.039 and p=0.015, respectively). CONCLUSION: Resveratrol had significant anti-atherogenic and anti-inflammatory effects in an animal model with rabbits fed a hypercholesterolemic diet (1 percent cholesterol).

Rosiglitazona e lesão vascular em coelhos hipercolesterolêmicos: avaliação da formação neointimal / Rosiglitazone and vascular injury in hypercholesterolemic rabbits: neointimal formation assessment / Rosiglitazona y lesión vascular en conejos hipercolesterolémicos

FUNDAMENTO: O uso da rosiglitazona tem sido o objeto de extensas discussões. OBJETIVO: Avaliar os efeitos da rosiglitazona nas artérias ilíacas, no local da injúria e na artéria contralateral, de coelhos hipercolesterolêmicos submetidos à lesão por cateter-balão. MÉTODOS: Coelhos brancos machos receberam uma dieta hipercolesterolêmica através de gavagem oral por 6 semanas e foram divididos em 2 grupos: grupo rosiglitazona (GR - 14 coelhos tratados com rosiglitazona por 6 semanas) e grupo controle (GC - 18 coelhos sem rosiglitazona). Os animais foram submetidos a lesão por cateter-balão na artéria ilíaca direita no 14º dia. RESULTADOS: Na artéria ilíaca contralateral, não houve diferença significante na razão entre as áreas intimal e medial (RIM) entre os grupos GR e GC. A rosiglitazona não reduziu a probabilidade de lesões tipo I, II ou III (72,73 por cento vs 92,31 por cento; p=0,30) e lesões tipo IV ou V (27,27 por cento vs 7,69 por cento; p=0,30). Na artéria ilíaca homolateral, a área intimal era significantemente menor no GR quando comparado ao GC (p = 0,024). A área luminal era maior no GR quando comparado ao GC (p < 0,0001). Houve uma redução significante de 65 por cento na IMR no GR quando comparado ao GC (p = 0,021). Nenhum dos critérios histológicos para lesões ateroscleróticas tipos I a V (American Heart Association) foram encontrados na artéria ilíaca homolateral. CONCLUSÃO: Esses achados demonstram que a administração de rosiglitazona por 6 semanas impede a aterogênese no local da lesão, mas não em um vaso distante do sítio da lesão.

BACKGROUND: Rosiglitazone has been the focus of extensive discussion. OBJECTIVE: To evaluate the effects of rosiglitazone on iliac arteries, both at the injury site and the contralateral artery, of hypercholesterolemic rabbits undergoing balloon catheter injury. METHODS: White male rabbits were fed a hypercholesterolemic diet by oral gavage for 6 weeks and divided into two groups as follows: rosiglitazone group (14 rabbits treated with rosiglitazone during 6 weeks) and the control group (18 rabbits without rosiglitazone). Animals underwent balloon catheter injury of the right iliac artery on the 14th day. RESULTS: In the contralateral iliac artery, there was no significant difference in the intima/media layer area ratio (IMR) between the control and rosiglitazone groups. Rosiglitazone did not reduce the probability of type I, II, or III lesions (72.73 percent vs 92.31 percent; p=0.30) and type IV or V lesions (27.27 percent vs 7.69 percent; p=0.30). As for the homolateral iliac artery, the intimal area was significantly lower in the rosiglitazone group, as compared to the control group (p = 0.024). The luminal layer area was higher in the rosiglitazone group vs. the control group (p < 0.0001). There was a significant reduction of 65 percent in the IMR in the rosiglitazone group vs the control group (p = 0.021). None of the histological criteria for type I-V atherosclerotic lesions (American Heart Association) were found in the homolateral iliac artery. CONCLUSION: These findings demonstrate that rosiglitazone given for 6 weeks prevents atherogenesis at the injury site, but not in a vessel distant from the injury site.

FUNDAMENTO: El uso de rosiglitazona ha estado siendo el objeto de extensas discusiones. OBJETIVO: Evaluar los efectos de la rosiglitazona en las arterias ilíacas, en el local de la injuria y en la arteria contralateral, de conejos hipercolesterolémicos sometidos a la lesión por catéter-balón. MÉTODOS: Conejos blancos machos recibieron una dieta hipercolesterolémica a través de gavage oral por 6 semanas y se los dividieron en 2 grupos: grupo rosiglitazona (GR - 14 conejos tratados con rosiglitazona por 6 semanas) y grupo control (GC - 18 conejos sin rosiglitazona). Los animales se sometieron a lesión por catéter-balón en la arteria ilíaca derecha en el 14º día. RESULTADOS: En la arteria ilíaca contralateral, no hubo diferencia significativa en la razón entre las áreas íntima y media (RIM) entre los grupos GR y GC. La rosiglitazona no redujo la probabilidad de lesiones tipo I, II ó III (72,73 por ciento vs 92,31 por ciento; p=0,30) y lesiones tipo IV ó V (27,27 por ciento vs 7,69 por ciento; p=0,30). En la arteria ilíaca homolateral, el área intima era significantemente menor en el GR cuando comparado al GC (p = 0,024). El área luminal era mayor en el GR cuando comparado al GC (p < 0,0001). Hubo una reducción significante del 65 por ciento en la IMR en el GR cuando comparado al GC (p = 0,021). Ningún de los criterios histológicos para lesiones ateroscleróticas tipos I a V (American Heart Association) se encontraron en la arteria ilíaca homolateral. CONCLUSIÓN: Estos hallazgos demuestran que la administración de rosiglitazona por 6 semanas impide la aterogénesis en el local de la lesión, pero no en un vaso distante del sitio de la lesión.

Aterosclerose experimental em coelhos / Experimental atherosclerosis in rabbits

Numerosas pesquisas têm sido realizadas utilizando modelos experimentais para estudar o desenvolvimento da aterosclerose com dieta induzindo hiperlipidemia. Devido ao fato de que coelhos são muito sensíveis a dietas ricas em colesterol e acumulam grandes quantidades no plasma, a utilização destes animais como modelo experimental para avaliar o desenvolvimento de aterosclerose é de grande relevância, trazendo informação sobre fatores que contribuem para progressão e regressão aplicadas a situações humanas. Sendo assim, nessa revisão a função aterogênica do colesterol é mostrada em trabalhos que incluem o coelho como modelo experimental, uma vez que este animal tornou-se o mais popular modelo experimental de aterosclerose.

Many researches have been conducted in experimental models in order to study the development of atherosclerosis from hyperlipidemia-inducing diets. Since rabbits are very sensitive to cholesterol-rich diets and accumulate large amounts of cholesterol in their plasma, their use as experimental models to evaluate the development of atherosclerosis is highly relevant and brings information on factors that contribute to the progression and regression of this condition that can be applied to humans. As such, this review includes studies on the atherogenic function of cholesterol based on rabbits as the experimental model, since they have become the most largely used experimental model of atherosclerosis.

Modulatory effects of rutin on biochemical and hematological parameters in hypercholesterolemic Golden Syrian hamsters

Flavonoids have been reported to exhibit several pharmacological properties, mainly in cardiovascular and inflammatory diseases. In the present study, we observed that rutin, a known glycosylated flavonoid isolated from Dimorphandra mollis, had a lowering effect on plasma triglyceride levels of diet-induced hypercholesterolemic Golden Syrian hamsters, but did not change total cholesterol and high-density lipoprotein cholesterol levels. Moreover, high-fat or rutin supplemented diets showed no immunotoxic effects, since no significant changes were observed on total white blood cells, granulocytes and mononuclear cells, as well as on the neutrophil apoptosis degree, when compared to untreated animals. Therefore, rutin seems to be a selective and non-toxic modulator of hypercholesterolemia, which can be promising for the development of new drugs.

Os flavonóides possuem diversas propriedades farmacológicas, principalmente nas doenças cardiovasculares e inflamatórias. No presente estudo, observamos que a rutina, um conhecido flavonóide glicosilado isolado da Dimorphandra mollis, diminuiu o nível de triglicerídeos plasmáticos em hamsters Golden Syrian hipercolesterolêmicos sem alterar os níveis de colesterol total e colesterol HDL. Além disso, observamos que dietas hipercolesterolêmicas ou suplementadas com rutina não apresentaram efeito imunotóxico, uma vez que nenhuma alteração significativa foi observada nos leucócitos totais, granulócitos e células mononucleares, bem como no grau de neutrófilos em apoptose, quando comparado com animais não tratados. Portanto, a rutina parece ser um modulador seletivo e não tóxico da hipercolesterolemia, o que pode ser promissor para o desenvolvimento de novos fármacos.

Avaliação das alterações precoces na coróide e esclera ocorridas em coelhos hipercolesterolêmicos: estudo histológico e histomorfométrico / Evaluation of choroid and sclera early alterations in hypercholesterolemic rabbits: histologic and histomorphometric study

OBJETIVO: Demonstrar experimentalmente, através de exames histológicos e histomorfométricos, as alterações degenerativas da esclera e coróide desencadeadas precocemente pela dieta hipercolesterolêmica. MÉTODOS: Coelhos New Zealand foram organizados em dois grupos: GC (grupo controle), composto por 6 coelhos (6 olhos), recebeu dieta normal por 6 semanas; G1, composto por 12 coelhos (12 olhos), tratado previamente com ração colesterol a 1 por cento (Sigma-Aldrich) por 2 semanas e a partir do 14º dia com ração colesterol a 0,5 por cento (Sigma-Aldrich). Os olhos foram submetidos à análise histológica, avaliados com corante de hematoxilina-eosina e ao exame morfométrico. A análise histomorfométrica foi realizada no setor posterior, adjacente ao disco óptico, e na periferia. RESULTADOS: O GC apresentou espessura média da esclera e coróide na periferia de 228,61 ± 31,71 micrômetros, enquanto na região posterior de aproximadamente 246,07 ± 25,66 micrômetros. No G1, observou-se espessura média da esclera e coróide na periferia de aproximadamente 303,56 ± 44,21 micrômetros, enquanto na região posterior de aproximadamente 295,59 ± 62,59. Houve diferença estatisticamente significativa da espessura da esclera e coróide entre os grupos na região periférica (p<0,001), não ocorrendo o mesmo no setor posterior (p=0,250). O aumento da espessura da parede de G1 em relação ao GC deve-se principalmente à quantidade elevada de histiócitos e fibras colágenas. CONCLUSÃO: Este estudo demonstrou que a dieta hipercolesterolêmica em coelhos induz rapidamente aumento da espessura da coróide e esclera, principalmente à custa de histiócitos e fibras colágenas.

PURPOSE: To demonstrate experimentally, by means of histological and histomorphometric examinations, the sclera and choroid degenerative alterations, which take place at an early stage due to a hypercholesterolemic diet. METHODS: New Zealand rabbits were divided into two groups: CG (control group) of 6 rabbits (6 eyes) received a regular diet for 6 weeks; G1, of 12 rabbits (12 eyes), was first fed a 1 percent cholesterol diet (Sigma-Aldrich) for 2 weeks and then from the 14th day on a 0.5 percent cholesterol diet (Sigma-Aldrich). The eyes underwent a histological analysis, stained with hematoxiline-eosine, and a morphometric examination. The histomorphometric analysis was performed in the posterior region, adjacent to the optic disk, and in the peripheral region. RESULTS: The CG presented a mean sclera and choroid thickness of 228.61 ± 31.71 micrometers in the peripheral region, while the thickness in the posterior region was approximately 246.07 ± 25.66 micrometers. In G1, these values were 303.56 ± 44.21 micrometers in the peripheral region and 295.59 ± 62.59 in the posterior region. There was a statistically significant difference in the sclera and choroid thickness between the groups in the peripheral region (p<0.001); however, this difference did not occur in the posterior region (p=0.250). The large number of histiocytes and collagen fibers accounted for the increase of G1 wall thickness in relation to CG. CONCLUSION: This study demonstrated that the hypercholesterolemic diet in rabbits induces a fast increase in the choroid and sclera thickness, mainly due to the increase in the number of histiocytes and collagen fibers.

Efeitos de hipolipemiantes e polimorfismos sobre a expressão dos genes HMGCR, LDLR, SREBF1a, SREBF2, SCAP e NPC1L1 em indivíduos hipercolesterolêmicos / Lipid lowering and polymorphisms effects on the expression of HMGCR, LDLR, SREBF1a, SREBF2, SCAP and NPC1L1 genes in hypercholesterolemic subjects

A homeostase do colesterol é mediada por proteínas envolvidas na absorçao (NPC1L1), regulação (SREBP1, SREBP2, SCAP), síntese (HMGCR) e remoção plasmática (LDLR). Os fármacos inibidores da síntese (vastatinas) e absorção (ezetimiba) do colesterol são potentes agentes hipocolesterolemiantes. Alteracões em vários genes têm sido associadas a diferenças na resposta a diversos agentes terapêuticos. Com a finalidade de estudar os efeitos de hipolipemiantes e polimorfismos sobre a expressão dos genes HMGCR, LDLR, SREBF1a, SREBF2, SCAP e NPC1L1, foram selecionados 25 indivíduos com hipercolesterolemia familial (HF), 72 com hipercolesterolemia não familial (HNF) e 125 indivíduos normolipidêmicos e sem doença cardiovascular (NL). Os indivíduos HF foram tratados com sinvastatina (40 mg/dia/4 sem) combinada ou não com ezetimiba (10 mg/dia/4sem) e os HNF foram tratados com atorvastatina (10 mg/dia/4sem). Amostras de sangue foram obtidas antes e após o tratamento para a extração de DNA e RNA e analise do perfil lipídico sérico. A expressão de mRNA dos genes SREBF1a, SREBF2, SCAP, HMGCR, LDLR e NPC1L1 em células mononucleares do sangue periférico (CMSP) foi determinada por RT-PCR em tempo real empregando-se o gene da GAPD como controle endógeno...

Vascular and metabolic response to statin in the mildly hypertensive hypercholesterolemic elderly

INTRODUCTION: Much evidence indicates the importance of the endothelium and hypercholesterolemia in atherosclerosis, as well as the decline in endothelial function with aging. However, it is unclear if treating dyslipidemia in elderly patients improves endothelial function and reduces C-reactive protein levels. OBJECTIVES: To evaluate vasomotor function, lipids and C-reactive protein in mildly hypertensive and hypercholesterolemic elderly patients treated with atorvastatin. METHODS: Forty-seven elderly Brazilian subjects (> 65 years old) with LDL cholesterol (LDL-c) > 130 mg/dL were randomly assigned, in a double-blinded manner, to receive either placebo (n = 23) or 20 mg/day of atorvastatin (n = 24) for 4 weeks. Exclusion criteria included diabetes, serious hypertension, obesity, steroid use, hormone replacement, and statin use within the previous six months. All patients underwent clinical examinations, laboratory tests (glucose, lipids, liver enzymes, creatine phosphokinase and high sensitivity C-reactive protein) and assessment of vasomotor function by high-resolution ultrasound examination of the brachial artery (flow-mediated dilation and sublingual nitrate), both before and after treatment. RESULTS: The patients were 65 to 91 years old; there was no significant difference between basal flow-mediated dilation of placebo (7.3 ± 6.1 percent) and atorvastatin (4.5 ± 5.1 percent; p = 0.20). The same was observed after treatment (6.6 ± 6.2 vs. 5.0 ± 5.6; p = 0.55). The initial nitrate dilatation (8.1 ± 5.4 percent vs. 10.8 ± 7.5 percent; p = 0.24) and that after 4 week treatment (7.1 ± 4.7 percent vs. 8.6 ± 5.0 percent; p = 0.37) were similar. Atorvastatin produced a reduction of 20 percent of the C-reactive protein and 42 percent in the LDL-c; however, there were no changes in the flow-mediated dilation. CONCLUSIONS: Atorvastatin produced a significant change of lipids and C-reactive protein; however, there were no changes in vasomotor ...

Effect of Lactobacillus delbrueckii on cholesterol metabolism in germ-free mice and on atherogenesis in apolipoprotein E knock-out mice

Elevated blood cholesterol is an important risk factor associated with atherosclerosis and coronary heart disease. Several studies have reported a decrease in serum cholesterol during the consumption of large doses of fermented dairy products or lactobacillus strains. The proposed mechanism for this effect is the removal or assimilation of intestinal cholesterol by the bacteria, reducing cholesterol absorption. Although this effect was demonstrated in vitro, its relevance in vivo is still controversial. Furthermore, few studies have investigated the role of lactobacilli in atherogenesis. The aim of the present study was to determine the effect of Lactobacillus delbrueckii on cholesterol metabolism in germ-free mice and the possible hypocholesterolemic and antiatherogenic action of these bacteria using atherosclerosis-prone apolipoprotein E (apo E) knock-out (KO) mice. For this purpose, Swiss/NIH germ-free mice were monoassociated with L. delbrueckii and fed a hypercholesterolemic diet for four weeks. In addition, apo E KO mice were fed a normal chow diet and treated with L. delbrueckii for 6 weeks. There was a reduction in cholesterol excretion in germ-free mice, which was not associated with changes in blood or liver cholesterol concentration. In apo E KO mice, no effect of L. delbrueckii was detected in blood, liver or fecal cholesterol. The atherosclerotic lesion in the aorta was also similar in mice receiving or not these bacteria. In conclusion, these results suggest that, although L. delbrueckii treatment was able to reduce cholesterol excretion in germ-free mice, no hypocholesterolemic or antiatherogenic effect was observed in apo E KO mice.

Hypercholesterolemia and tissue-specific differential mRNA expression of type-1 5'-iodothyronine deiodinase under different selenium status in rats

Type-1 5'-iodothyronine deiodinase (5'-DI) is responsible for conversion of T4 to T3. Selenium (Se) is an integral part of this enzyme. Keeping in view the strong association between atherosclerosis and hypothyroidism, the present study examined the behavior of 5'-DI in liver, aorta and thyroid during hypercholesterolemia following different Se status, i.e., Se deficiency (0.02ppm), adequate (0.2ppm) and excess dose (1ppm) in SD male rats. Animals were fed a control or high-cholesterol diet (2%) for 1 and 2 months. 5'-DI activity and mRNA expression was measured by RIA and RT-PCR respectively. In liver and aorta, 5'-DI expression significantly decreased with the Se-deficient and the high-cholesterol diet. The trend was opposite in thyroid, i.e., mRNA expression increased significantly during selenium deficiency and with a high-cholesterol feeding. But with 1ppm Se supplementation, the 5'-DI expression increased in all the three tissues. The present study indicates that hypercholesterolemia along with selenium deficiency is co-responsible for differential regulation of 5'-DI enzyme in thyroidal vs. extrathyroidal tissues. Distinct regulation of 5'-DI in the thyroid reflects the clinical importance of this selenoprotein during hypercholesterolemia as this enzyme is essential for T3 production, which further has a vital role in the maintenance of lipid metabolism.

Ezetimiba: farmacocinética e terapêutica / Ezetimibe: pharmacokinetics and therapeutics

Ezetimiba é um inibidor da absorção do colesterol que é glucuronidado no fígado após sua rápida absorção nos enterócitos, onde juntamente com os seus metabólitos, exerce as suas ações hipolipidêmicas, reduzindo a absorção do colesterol através da inibição do transporte do colesterol por enzimas transportadoras específicas. Esta droga pode ser utilizada uma vez ao dia, em função de sua meia-vida plasmática prolongada e normalmente é muito bem tolerada. A eliminação da ezetimiba e de seus metabólitos é feita principalmente pela excreção fecal. Em geral, o uso da ezetimiba isolada promove modestos efeitos no LDL plasmático, entretanto, quando combinada às estatinas, importantes mudanças no perfil lipídico podem ser observadas.

Efeitos da atorvastatina, fluvastatina, pravastatina e simvastatina sobre a função endotelial, a peroxidação lipídica e a aterosclerose aórtica em coelhos hipercolesterolêmicos / Effects of atorvastatin, fluvastatin, pravastatin, and simvastatin on endothelial function, lipid peroxidation, and aortic atherosclerosis in hypercholesterolemic rabbits

OBJETIVO: Comparar os efeitos da atorvastatina, fluvastatina, pravastatina e simvastatina sobre a função endotelial, a aterosclerose aórtica e o teor de malonodialdeído (MDA) nas LDL nativas, oxidadas e na parede arterial de coelhos hipercolesterolêmicos, depois que as doses destas estatinas foram ajustadas para reduzir o colesterol total plasmático a valores similares. MÉTODOS: Coelhos machos, foram separados em grupos de 10 animais (n=10), chamados hipercolesterolêmico (controle), atorvastatina, fluvastatina, pravastatina e normal. A exceção do grupo normal, os animais foram alimentados com ração padrão acrescida de colesterol a 0,5 por cento e óleo de coco a 2 por cento durante 45 dias. As drogas foram administradas a partir do 15° dia do início do experimento e no 30° dia, as doses foram ajustadas, através do controle do colesterol plasmático, para obter valores semelhantes em cada grupo. Ao final do experimento foi dosado o colesterol plasmático e as lipoproteinas e retirado um segmento de aorta torácica para estudo da função endotelial, da peroxidação lipídica e exame histológico para medida da aterosclerose aórtica. RESULTADOS: As estatinas reduziram significantemente o colesterol total plasmático, as LDL-colesterol e a aterosclerose aórtica. O teor de MDA também foi significantemente reduzido nas LDL nativas e oxidadas, assim como na parede arterial. O relaxamento-dependente do endotélio foi significantemente maior no grupo tratado em comparação ao hipercolesterolêmico. CONCLUSÃO: As estatinas, em doses ajustadas, tiveram efeito significante e similar em reduzir a peroxidação lipídica nas LDL e na parede arterial, na regressão da aterosclerose aórtica e na reversão da disfunção endotelial.

Ausência de efeito do captopril no metabolismo de uma emulsão lipídica artificial semelhante aos quilomícrons em pacientes hipertensos e hipercolesterolêmicos / Lack of effect of captopril on the metabolism of an artificial lipid emulsion similar to chylomicrons in hypertensive hypercholesterolemic patients

OBJETIVO: Avaliar o efeito do captopril, sobre o metabolismo dos quilomícrons e de seus remanescentes e as possíveis alterações nas concentrações dos lípides plasmáticos em hipertensos e hipercolesterolêmicos. MÉTODOS: O metabolismo dos quilomícrons foi testado pelo método da emulsão lipídica artificial de quilomícrons marcada com 3H-oleato de colesterol, foi injetada intravenosamente em 10 pacientes com hipertensão arterial leve-moderada antes e após 45 dias de tratamento com captopril (50 mg/dia). Após injeção, foram coletadas amostras de sangue durante 60min em intervalos de tempo pré-estabelecidos para determinar a curva de decaimento e a taxa fracional de remoção (TFR em min-1), bem como o tempo de residência no plasma, da emulsão lipídica artificial, por análise compartimental. As concentrações dos lípides do plasma também foram avaliadas antes e após o tratamento. RESULTADOS: A taxa fracional de remoção (em min-1) da emulsão lipídica antes e após o tratamento com captopril (0,012±0,003 e 0,011±0,003, respectivamente; p=0,85, n.s.) ou o tempo de permanência da emulsão no plasma (83,3±20,8 e 90,9± 22,5 min, n.s.) não se alteraram, mas os níveis de colesterol total e de LDL-c reduziram-se em 7 por cento e 10 por cento respectivamente (p=0,02). As concentrações de HDL-c, triglicérides, Lp(a) e apolipoproteínas AI e B não se modificaram. CONCLUSÃO: O tratamento com captopril, avaliado pelo método da emulsão lipídica artificial, não provoca alterações deletérias no metabolismo dos quilomícrons e seus remanescentes.