Apolipoprotein E polymorphisms in adults over 60 years of age with mild cognitive impairment and Alzheimer's disease in different Venezuelan populations / Polimorfismos del gen de la apolipoproteína E en adultos mayores de 60 años con disminución de la memoria cognitiva y enfermedad de Alzheimer en diferentes poblaciones venezolanas

Introduction: Alzheimer's disease represents a serious public health problem that tends to worsen over time. Among the most important genetic predisposing factors is the presence of the ε4 allele of the apoprotein E gene (APOE). Objective: To determine the allelic and genotypic frequencies of the APOE isoforms in adults over 60 years old with mild cognitive impairment and Alzheimer's disease in Gran Caracas and in the indigenous Pemón community of the Kamarata-Kanaimö area, Bolívar State. Materials and methods: We studied 267 patients: 96 controls, 40 with mild cognitive impairment, 108 with Alzheimer's from Caracas, and 23 individuals from Kamarata-Kanaimö. The APOE isoforms were determined with the AP1210Z: Seeplex® ApoE Genotyping kit. Results: The allele ε4 showed a significant association with mild cognitive impairment (OR=5.03; 95% CI: 0.98-25.70) and EA (OR=5.78; 95% CI: 1.24-26.85). The genotype frequencies for the control and mild cognitive impairment groups were ε3/ε3> ε3/ε4> ε2/ε4> ε3/ε2> ε4/ε4, and for the Alzheimer's group, ε3/ε3> ε3/ε4> ε4/ε4> ε2/ε4> ε3/ε2 In Kamarata-Kanaimö, the order was ε3/ε3> ε3/ε4> ε4/ε4; the allele ε2 was not found in this group. Conclusions: APOE allelic and genotypic frequencies in our sample showed a similar distribution to those found in other studies in Venezuela and the Americas. The absence of the ε2 allele in the indigenous community of Kamarata-Kanaimö warrants further investigation. The positive association of the ε4 allele with both Alzheimer's and mild cognitive impairment was reinforced. The early determination of the ε4 allele carriers can help establish preventive measures in our population.

Introducción. La enfermedad de Alzheimer constituye un problema de salud pública que tiende a agravarse en el tiempo. Entre los factores genéticos de predisposición más importantes, se encuentra la presencia del alelo ε4 del gen APOE que codifica para la apoproteína E. Objetivo. Determinar las frecuencias alélicas y genotípicas de las isoformas de APOE en adultos mayores de 60 años con memoria cognitiva disminuida y Alzheimer, en la gran Caracas y en la comunidad indígena pemón de la zona Kamarata-Kanaimö, Estado Bolívar. Materiales y métodos. Se estudiaron 267 pacientes: 96 controles, 40 con memoria cognitiva disminuida y 108 con Alzheimer procedentes de Caracas, y 23 individuos de Kamarata-Kanaimö. Las isoformas de APOE se determinaron con el estuche AP1210Z: Seeplex ApoE genotyping™. Resultados. El alelo ε4 mostró asociación significativa con la memoria cognitiva disminuida (OR=5,03; IC95% 0,98-25,70) y la enfermedad de Alzheimer (OR=5,78; IC95% 1,24-26,85). Las frecuencias genotípicas de los grupos de control y con memoria cognitiva disminuida, fueron: ε3/ε3> ε3/ε4> ε2/ε4> ε3/ε2> ε4/ε4, y las del grupo con Alzheimer: ε3/ε3> ε3/ε4> ε4/ε4> ε2/ε4> ε3/ε2. En Kamarata-Kanaimö, el orden fue ε3/ε3> ε3/ε4> ε4/ε4 y no se encontró el alelo ε2. Conclusiones. Las frecuencias alélicas y genotípicas de APOE en la muestra tuvieron una distribución similar a la de otros estudios en Venezuela y las Américas. La ausencia del alelo ε2 en la comunidad indígena de Kamarata-Kanaimö amerita mayor investigación. Se constató la asociación positiva del alelo ε4 en personas con la enfermedad de Alzheimer y con memoria cognitiva disminuida. Conocer precozmente los pacientes portadores de este alelo puede ayudar a establecer medidas preventivas en nuestra población.

Polimorfismos del gen de la apolipoproteína E en adultos mayores de 60 años con disminución de la memoria cognitiva y enfermedad de Alzheimer en diferentes poblaciones venezolanas / Apolipoprotein E polymorphisms in adults over 60 years of age with mild cognitive impairment and Alzheimer's disease in different Venezuelan populations

Introducción. La enfermedad de Alzheimer constituye un problema de salud pública que tiende a agravarse en el tiempo. Entre los factores genéticos de predisposición más importantes, se encuentra la presencia del alelo ε4 del gen APOE que codifica para la apoproteína E. Objetivo. Determinar las frecuencias alélicas y genotípicas de las isoformas de APOE en adultos mayores de 60 años con memoria cognitiva disminuida y Alzheimer, en la gran Caracas y en la comunidad indígena pemón de la zona Kamarata-Kanaimö, Estado Bolívar. Materiales y métodos. Se estudiaron 267 pacientes: 96 controles, 40 con memoria cognitiva disminuida y 108 con Alzheimer procedentes de Caracas, y 23 individuos de Kamarata-Kanaimö. Las isoformas de APOE se determinaron con el estuche AP1210Z: Seeplex ApoE genotyping™. Resultados. El alelo ε4 mostró asociación significativa con la memoria cognitiva disminuida (OR=5,03; IC95% 0,98-25,70) y la enfermedad de Alzheimer (OR=5,78; IC95% 1,24-26,85). Las frecuencias genotípicas de los grupos de control y con memoria cognitiva disminuida, fueron:ε3/ε3> ε3/ε4> ε2/ε4> ε3/ε2> ε4/ε4, y las del grupo con Alzheimer: ε3/ε3> ε3/ε4> ε4/ε4> ε2/ε4> ε3/ε2. En Kamarata-Kanaimö, el orden fue ε3/ε3> ε3/ε4> ε4/ε4 y no se encontró el alelo ε2. Conclusiones. Las frecuencias alélicas y genotípicas de APOE en la muestra tuvieron una distribución similar a la de otros estudios en Venezuela y las Américas. La ausencia del alelo ε2 en la comunidad indígena de Kamarata-Kanaimö amerita mayor investigación. Se constató la asociación positiva del alelo ε4 en personas con la enfermedad de Alzheimer y con memoria cognitiva disminuida. Conocer precozmente los pacientes portadores de este alelo puede ayudar a establecer medidas preventivas en nuestra población.

Introduction: Alzheimer's disease represents a serious public health problem that tends to worsen over time. Among the most important genetic predisposing factors is the presence of the ε4 allele of the apoprotein E gene (APOE). Objective: To determine the allelic and genotypic frequencies of the APOE isoforms in adults over 60 years old with mild cognitive impairment and Alzheimer's disease in Gran Caracas and in the indigenous Pemón community of the Kamarata-Kanaimö area, Bolívar State. Materials and methods: We studied 267 patients: 96 controls, 40 with mild cognitive impairment, 108 with Alzheimer's from Caracas, and 23 individuals from Kamarata-Kanaimö. The APOE isoforms were determined with the AP1210Z: Seeplex® ApoE Genotyping kit. Results: The allele ε4 showed a significant association with mild cognitive impairment (OR=5.03; 95% CI: 0.98-25.70) and EA (OR=5.78; 95% CI: 1.24-26.85). The genotype frequencies for the control and mild cognitive impairment groups were ε3/ε3> ε3/ε4> ε2/ε4> ε3/ε2> ε4/ε4, and for the Alzheimer's group, ε3/ε3> ε3/ε4> ε4/ε4> ε2/ε4> ε3/ε2 In Kamarata-Kanaimö, the order was ε3/ε3> ε3/ε4> ε4/ε4; the allele ε2 was not found in this group. Conclusions:APOE allelic and genotypic frequencies in our sample showed a similar distribution to those found in other studies in Venezuela and the Americas. The absence of the ε2 allele in the indigenous community of Kamarata-Kanaimö warrants further investigation. The positive association of the ε4 allele with both Alzheimer's and mild cognitive impairment was reinforced. The early determination of the ε4 allele carriers can help establish preventive measures in our population.

A new approach of immunotherapy against Crotalus snakes envenoming: ostrich (Struthio camelus) egg yolk antibodies (IgY-technology) / Un nuevo enfoque de inmunoterapia contra el envenenamiento de serpientes Crotalus: anticuerpos de yema de huevo de avestruz (Struthio camelus) (tecnología IgY)

Abstract Crotalid envenomation is a neglected collective health problem involving many countries in America, which need secure and inexpensive snake anti-venom treatments. Here, high antibody titers (IgY) were raised in the Ostrich (Struthio camelus) egg yolk by immunizing with the venom of Venezuelan venomous Crotalus snakes. Ostriches were immunized with a pool of venoms from common rattlesnake (Crotalus durissus cumanensis), Uracoan rattlesnake (Crotalus vegrandis), Guayana rattlesnake (Crotalus durissus ruruima) and black rattlesnake (Crotalus pifanorum). The anti-snake venom antibodies were prepared from egg yolk by the water dilution method, enriched by the addition of caprylic acid (CA) and precipitation with ammonium sulfate at 30% (W/V). The purity and molecular mass of the final product was satisfactory, yielding a single ∼ 175 kDa band in SDS-PAGE gels ran under non-reducing conditions. In the immunoblot analysis, specific binding of the antivenom was observed with most venom proteins. The LD50 was 16.5 g/mouse (825 μg/kg body weight). High titers of IgY against Crot/pool venom were shown by ELISA. The median effective dose (ED50) was 19.66 mg/2LD50. IgY antibodies neutralized efficiently the Crot/pool venom lethality. As far as we know, this is the first anti-snake venom produced in ostriches, which could make this technology an affordable alternative for low-income countries, since it is likely to produce manteniabout 2-4 g of IgY per ostrich egg. Hence, almost 400 g of IgY can be purified from only one ostrich during a year. In addition, there are enormous differences in the cost of investment in the maintenance of horses, from the points of view of infrastructure, feeding and veterinary care, in which the cost can reach USD 100 per animal per day, compared to a maintenance cost of USD 146 per month per producing bird. These results are encouraging and could easily be extrapolated to the manufacturing of other antivenoms and antitoxins as well, as they could be applied to the manufacturing of potential diagnostic tools.

Resumen El envenenamiento por crotálidos es un problema de salud colectiva desatendido, que involucra a muchos países del continente americano, los cuales necesitan tratamientos seguros y económicos. En este trabajo, se obtuvieron títulos altos de anticuerpos (IgY) producidos en yema de huevo de avestruz (Struthio camelus) mediante la inmunización con el veneno de serpientes venezolanas del genero Crotalus. Se inmunizaron avestruces con una colección de veneno de serpientes de cascabel común (Crotalus durissus cumanensis), cascabel de Uracoa (Crotalus vegrandis), cascabel de Guayana (Crotalus durissus ruruima) y cascabel negra (Crotalus pifanorum). Los anticuerpos anti-veneno de serpiente se prepararon a partir de yema de huevo por el método de dilución en agua, enriquecidos mediante la adición de ácido caprílico (CA), seguido de una precipitación con sulfato de amonio al 30% (P/V). La pureza y masa molecular de los anticuerpos (IgY) se definieron mediante ensayos de SDS-PAGE nativos y las masas moleculares se establecieron electroforéticamente, obteniéndose una única banda de IgY de ∼ 175 kDa. El análisis de inmunotransferencia mostró la unión específica del antiveneno con la mayoría de las proteínas del veneno. La DL50 fue de 16,5 μg/ratón (825 μg / kg de peso corporal); Se mostraron títulos altos de IgY contra el veneno de Crot / pool mediante ELISA. La dosis mediana efectiva (DE50) fue de 19,66 mg/2 LD50. Los anticuerpos IgY neutralizaron eficazmente la letalidad del veneno de Crot / pool. Hasta donde sabemos, se trata del primer antídoto de serpiente producido en avestruces, lo que podría abaratar la producción de este tratamiento en países del tercer mundo. Ya que es probable que se obtengan alrededor de 2-4 g de IgY por huevo de avestruz. Por lo tanto, se podrían purificar casi 400 g de IgY de un solo avestruz durante un año. Asimismo, debido a las enormes diferencias en el costo de inversión en el mantenimiento de los caballos desde el punto de vista de infraestructura, alimentación y atención veterinaria, en los que el costo puede llegar a los 100 USD por día, frente a los 146 USD por mes de mantenimiento de la producción de aves. Estos resultados abren un campo terapéutico, para la fabricación de otros antivenenos contra un amplio espectro de toxinas y también como probables herramientas de diagnóstico.

Chronic Stress in Cognitive Processes: Cortisol Dynamic Range of Secretion Is Associated with Perception of Unsafety Environment in a Venezuelan Population.

BACKGROUND: Understanding diurnal secretion of cortisol in association with behavioral attitudes as a result of perception of unsafety environment is a main interest in prospective studies establishing the impact of chronic stress in cognitive processes. Adaptive secretion of cortisol, a biomarker of the hypothalamic-hypophysis-adrenal (HPA) axis, has been correlated with perception of uncertainty in surroundings as a consequence of perseverative cognition and unconscious thoughts. OBJECTIVE: To determine whether diurnal secretion pattern of cortisol was associated with behavioral attitudes indexes generated from answers to standardized questionnaires from Panamerican Health Organization/World Health Organization (PAHO/WHO) agencies. METHODS: Saliva cortisol dynamic range was evaluated by immuno-essay. Cortisol awakening response (CAR) and total secreted cortisol was established in a cross-sectional study of four saliva samples per day from volunteers (n = 135) between 19 and 65 years old. RESULTS: Saliva cortisol dynamic range followed a significant decay along the day. Reduction of social interaction and increase of defensive behavioral attitude was associated with older groups of age. In this study, two subgroups of subjects with a steeper cortisol secretion (slope significant non-zero), and flatter cortisol secretion (slope no significant non-zero) were detected. Noticeable, we determined an association between measurements of cortisol secretion from subjects with a flatter cortisol dynamic range and behavioral defensive and inhibition of social interaction indexes. CONCLUSION: These findings suggested chronical dysregulation of HPA axis as a result of perseverative cognitive perception of unsafety environment which may be precedent to cognitive impairment in the population.

Acute toxicity, antinociceptive activity and indole alkaloids of aqueous extract from bark of Aspidosperma cuspa (Kunth) Blake.

UNLABELLED: ETNOPHARMACOLOGICAL RELEVANCE: Aspidosperma cuspa (Kunth) Blake (Apocynaceae) is popularly known as "amargosa" or "cuspa", and its bark is used in folk medicine primarily for pain. AIM OF THE STUDY: In the present study the acute toxicity, antinociceptive effect and alkaloids of the aqueous decoction extract of the Aspidosperma cuspa bark in mice was investigated. MATERIALS AND METHODS: Acute toxicity was tested using a variation of the method described by Lichfield and Wilcoxon. The antinociceptive activity was evaluated using the acetic acid induced writhing and tail-flick tests. The phytochemical analysis was performed. RESULTS AND CONCLUSION: Oral administration of the extract did not cause animal death (LD(50)>4 g/kg), and the histological analysis showed an absence of alterations in all organs examined. TD(50) of the extract was 0.5521 g/kg for male mice and 1.1565 g/kg for females. The aqueous extract at doses 276 mg/kg (p.o.) did not produce a significant inhibition of acetic acid-induced writhes, but showed a significant effect in tail-flick test. Naloxone, an opioid receptor antagonist, pretreatment inhibited significantly the antinociceptive activity of the extract. It is suggested that the aqueous decoction extract of the bark of Aspidosperma cuspa has an antinociceptive effect, and this may be mediated by opioid receptors. Three indole alkaloids (aspidocarpine, 11-methoxytubotaiwine and picraline) were isolated from the aqueous extract. The antinociceptive activity of the extract is presumed to be due to these compounds.

Hypoglycaemic effect of Croton cuneatus in streptozotocin-induced diabetic rats

Aqueous extract of the stem barks of Croton cuneatus Klotz (Euphorbiaceae) was investigated for hypoglycaemic activity in streptozotocin(STZ)-induced diabetic rats. Increasing doses of aqueous extract (6.5, 13, 26 and 52 mg/kg i.p.) were separately administered to groups of fasted normal and diabetic rats. Plasma glucose concentration, cholesterol and changes in body weight were evaluated. The chronic intraperitoneal (i.p.) administration of the extract for 22 days was found to induce significant reduction in blood glucose level. A comparison was made between the action of the aqueous extract of C. cuneatus and the reference standard drug glibenclamide. The results of this experimental animal study indicate that this plant has an antidiabetic activity in hiperglycaemic rat models.

A ação hipoglicemiante do extrato aquoso das cascas do caule de Croton cuneatus Klotz (Euphorbiaceae) foi investigada em ratos com diabetes induzida pela estreptozotocina (STZ). Doses crescentes do extrato aquoso (6,5, 13, 26 e 52 mg/kg i.p.) foram administradas separadamente a grupos de animais normais e diabéticos em jejum. Foram avaliadas as concentrações plasmáticas de glicose e colesterol, assim como mudanças no peso corporal. A administração crônica intraperitoneal (i.p.) do extrato durante 22 dias induziu uma redução significativa nos níveis de glicose sanguínea. Foi feita uma comparação entre o extrato aquoso de C. cuneatus e a droga de referência glibenclamida. Os resultados desse experimento indicam que esta planta possui atividade antidiabética em modelo com animais hiperglicêmicos.

Ondansetron and metformin-induced gastrointestinal side effects.

Treatment with metformin is associated with a high incidence of gastrointestinal side effects of unknown mechanism. Metformin is a biguanide derivative, which resembles 5-HT3-receptor agonists in its structure. Activation of 5-HT3 receptors is known to induce nausea, vomiting, and diarrhea. In this study, we investigated if the gastrointestinal side effects produced by metformin were antagonized by ondansetron, a selective antagonist of 5-HT3 receptors. Patients experiencing gastrointestinal side effects were randomized to ondansetron (4 mg bid p.o.) or placebo while maintained on metformin (double-blind, parallel-group design). If side effects persisted or worsened, metformin was discontinued and the patient considered a therapeutic failure. Of the 98 subjects treated with metformin, 22 developed side effects to match the study entry criteria. Diarrhea was the most frequent side effect. Subjects were randomized to ondansetron (10/2 F/M, 42.8 +/- 2.3 years, 28.6 +/- 1.1 kg/m2, 2585 +/- 35 mg/d metformin) or placebo (9/1 F/M, 43 +/- 4.3 years, 29.7 +/- 1.8 kg/m2, 2715 +/- 71 mg/d metformin). Ondansetron showed no efficacy against metformin-induced side effects. A comparable number of therapeutic failures were observed in ondansetron (8/12; 66%) and placebo-treated subjects (5/10; 50%) (P<0.1). Mean nausea scores (numeric analog scale) before and during treatment with ondansetron were 6.3 +/- 1 and 6.9 +/- 1 cm, respectively. Nausea scores averaged 7.3 +/- 1.5 and 5.9 +/- 1.5 cm, before and during treatment with placebo (P>0.1). In conclusion, 5-HT3 receptors do not seem to play a role in metformin-induced gastrointestinal side effects.

Lesion of caudate-putamen interneurons with kainic acid alters dopamine and serotonin metabolism in the olfactory tubercle of the rat.

1. The existence of functional interrelationships between dorsal and ventral regions of the rat striatum was investigated. Kainic acid (KA) was employed to induce neuronal lesions in the more dorsal striatum, the caudate-putamen (CP). Only one CP (one side) received KA. KA-induced neurotoxicity at the site of injection (CP) was evidenced by reductions in choline-acetyltransferase activity and in GABA levels, and by increases in the ratios metabolite/monoamine for dopamine (DA) and serotonin (5-HT). 2. In addition to the well-known local effects, direct stereotaxic injection of KA into the CP produced distant effects in the ipsilateral olfactory tubercle (OT). A dose-dependent increase in the levels of 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) and decreases in DA and 5-HT concentrations were observed in the OT ipsilateral to the CP injected with KA. With 1, 2, 3, and 4 microg of KA, the ratio DOPAC+HVA/DA in the OT was 30, 79, 140, and 173% higher, respectively, than control levels. With 2, 3, and 4 microg of KA, the levels of 5-HIAA were approximately 30, 60, and 120% higher than control values, and the changes in 5-HIAA were associated with significant reductions in 5-HT concentrations. 3. Our results suggest that the dorsal part of the striatum exerts important regulatory functions over the most ventral striatal region, the OT. Destruction of CP interneurons by KA leads to disinhibition of DA and 5-HT activities to the OT. The functional interactions between dorsal and ventral striatal regions may play a role in the integration of fundamental life-preserving, motivational, and goal-directed olfactory motor behaviors of rodents.