Do national health priorities align with Global Burden of Disease estimates on disease burden? An analysis of national health plans and official governmental websites.

OBJECTIVE: To investigate the alignment of national health priorities with a country's burden of disease as measured by disability-adjusted life years (DALYs). METHODS: We identified priorities in national health plans and the 20 most burdensome conditions measured by DALYs from the 2017 Global Burden of Disease Study. We computed point-biserial correlations (rpb) between DALYs and being nominated as a health priority and the pooled proportion (95% confidence intervals [CIs]) of the 20 most burdensome conditions nominated as a priority across countries. RESULTS: We identified national health plans and official governmental websites in 145 countries. There was little to no correlation (rpb = 0.06, 95% CI: 0.02 to 0.09) between national DALY data and whether a condition was nominated as a health priority. The pooled proportion of the 20 most burdensome conditions nominated as priorities across countries was 46%. HIV/AIDS had the greatest number of nominations as a national health priority (62 countries) as well as the greatest match with the burden of disease (among the top 20 most burdensome conditions in 51 [82%] countries). Low back pain, headache disorders and congenital birth defects had the lowest proportion of nominations as health priorities in countries where they were in the top 20 most burdensome conditions (6%, 6% and 11%, respectively). CONCLUSION: Globally, there were low correlations between national health priorities and GBD estimates on disease burden. Failing to prioritise health priorities according to burden may mean that insufficient resources have been directed to improve health outcomes for people with those health conditions.

Nasomaxillary effects of miniscrew-assisted rapid palatal expansion and two surgically assisted rapid palatal expansion approaches.

This retrospective study was performed to evaluate nasomaxillary changes in 36 patients at an advanced stage of skeletal maturity who underwent miniscrew-assisted rapid palatal expansion (MARPE) or surgically assisted rapid palatal expansion (SARPE) with/without an alar base cinch. Cone beam computed tomography images taken before and after expansion were analysed. Changes in the width of the dental arch (D66S, D66I), maxillary base (MxMol), and nasal floor and nasal cavity in the molar and canine regions (NaFMol, NaFCan, NaCMol, NaCCan) were compared, as well as changes in the choanal aperture (CA) and nasal soft tissue (NW). The MARPE technique produced smaller dental changes (D66S; P=0.025) and greater nasomaxillary expansion (MxMol, P=0.010; NaCMol, P=0.016; NaCCan, P=0.017; NaFMol, P=0.001; CA, P=0.002) than both SARPE techniques. Changes in NW did not differ significantly between the groups (P=0.200). MARPE uniformly increased the anterior and posterior widths of the nasal cavity. SARPE expanded the nasal cavity in a 'V-shape' pattern. Changes in the nasal cavity and choanal aperture related to the amount of dental arch expansion were greater for MARPE than for SARPE. All three approaches increased the width of the nasal soft tissue, although the cinch in SARPE limited this increase.

Fighting COVID-19 / Combatendo a COVID-19

Abstract The current COVID-19 pandemic caused by the novel coronavirus (SARS-CoV2) poses a threat to global health owing to its high rate of spread and severe forms of respiratory infection. The lack of vaccines and antivirals prevents clinical strategies against the disease, creating an emerging need for the development of safe and effective treatments. Strategies for vaccine development include complete vaccines against viruses, subunits, and nucleic acids, but are still in their early stages. Studies carried out to date on possible SARS-CoV2 drug targets highlight glycoprotein S, Mpro (main protease or protease type 3C), and a member of the transmembrane serine protease II families (TMPRSS2). However, due to the pandemic state, priority is given to marketed drugs. These include chloroquine (CQ), hydroxychloroquine (HCQ), nitazoxanide, remdesivir, Lopinavir/ritonavir (LPV / r), in addition to treatment with convalescent plasma. But, therapeutic specific effects against SARS-CoV2 have not yet been verified. Most of the information obtained about treatment is based on preliminary and limited studies. We conclude that, at this time of emergency, the search for new therapies is more urgent due to the need to save lives. Thus, we point out as interesting targets for future more specific research: glycoprotein S, Mpro, and TMPRSS2.

Resumo A pandemia de COVID-19 causada pelo novo Coronavírus (SARS-CoV2) representa uma ameaça à saúde global devido à alta taxa de disseminação e formas graves de infecção respiratória. A falta de vacinas e antivirais específicos dificultam as estratégias clínicas de controle da doença, criando a necessidade urgente do desenvolvimento de tratamentos seguros e eficazes. Com relação as estratégias para o desenvolvimento de vacinas, incluem-se: aquelas com o vírus completo, subunidades e ácidos nucléicos, mas estas ainda estão em estágios iniciais. Já sobre os estudos realizados até o momento buscando novos alvos terapêuticos contra o SARS-CoV2, destacam a glicoproteína S; Mpro (principal protease ou protease tipo 3C) e um membro da família transmembrana serina protease II (TMPRSS2). No entanto, devido ao estado pandêmico, tem sido dada prioridade aos medicamentos comercializados. Estes incluem a cloroquina (CQ); hidroxicloroquina (HCQ); nitazoxanida; remdesivir; Lopinavir / ritonavir (LPV/r); além do tratamento com plasma de pacientes curados. Porém, ainda não há uma estratégia terapêutica contra o SARS-CoV2 totalmente eficaz, e a maioria das informações obtidas sobre o tratamento é baseada em estudos preliminares e limitados. Concluímos então que, neste momento de emergência, a busca por novas terapias é algo urgente devido à necessidade de salvar vidas. Assim finalizamos sugerindo como alvos interessantes para futuras pesquisas específicas: a glicoproteína S, Mpro e o TMPRSS2.

Fighting COVID-19.

The current COVID-19 pandemic caused by the novel coronavirus (SARS-CoV2) poses a threat to global health owing to its high rate of spread and severe forms of respiratory infection. The lack of vaccines and antivirals prevents clinical strategies against the disease, creating an emerging need for the development of safe and effective treatments. Strategies for vaccine development include complete vaccines against viruses, subunits, and nucleic acids, but are still in their early stages. Studies carried out to date on possible SARS-CoV2 drug targets highlight glycoprotein S, Mpro (main protease or protease type 3C), and a member of the transmembrane serine protease II families (TMPRSS2). However, due to the pandemic state, priority is given to marketed drugs. These include chloroquine (CQ), hydroxychloroquine (HCQ), nitazoxanide, remdesivir, Lopinavir/ritonavir (LPV / r), in addition to treatment with convalescent plasma. But, therapeutic specific effects against SARS-CoV2 have not yet been verified. Most of the information obtained about treatment is based on preliminary and limited studies. We conclude that, at this time of emergency, the search for new therapies is more urgent due to the need to save lives. Thus, we point out as interesting targets for future more specific research: glycoprotein S, Mpro, and TMPRSS2.

Substituição do milho pelo sorgo sobre o desempenho zootécnico e na digestibilidade em coelhos / Replacement of corn by sorghum on zootechnical performance and digestibility in rabbits

O milho é a principal fonte de energia nas dietas animais. Em algumas regiões brasileiras, sua disponibilidade, principalmente na entressafra, é insuficiente para atender à demanda, fazendo com que seu preço se eleve. Neste estudo, objetivou-se avaliar a substituição do milho pelo sorgo sobre o desempenho zootécnico e a digestibilidade em coelhos. Foram utilizados 60 animais machos da raça Nova Zelândia Branco, divididos em três tratamentos: ração base milho (TM); ração base sorgo (TS) e ração base 50% de milho + 50% de sorgo (TMS). No ensaio de desempenho, avaliou-se ganho de peso (GP), consumo de ração (CR), conversão alimentar (CA), coeficientes de digestibilidade da matéria seca (CDMS), proteína bruta (CDPB), fibra em detergente neutro (CDFDN) e fibra em detergente ácido (CDFDA). Observou-se que o CRM, a CA e o GPM não foram afetados pela substituição do milho pelo sorgo, nos níveis de 50% e 100%. Os resultados de digestibilidade demonstraram maiores CDPB e CDFDN na ração base milho, não havendo diferenças entre os demais parâmetros estudados. O sorgo com baixo teor de tanino pode ser usado nas rações de crescimento de coelhos em níveis de substituição de 50% ou 100% da participação do milho, sem prejuízos para o desempenho zootécnico e a digestibilidade.(AU)

Corn is the main source of energy in animal diets. In some Brazilian regions, its availability, especially in the off-season, may be insufficient to meet demand, which causes prices to increase. In this context, the aim of this study was to evaluate the substitution of maize by sorghum on the performance and digestibility of rabbits. Sixty New Zealand White bucks were used, divided in three treatments, maize base ration (TM); based on grain sorghum ration (TS) and base ration 50% corn + 50% sorghum grain (TMS). In the performance test, weight gain (GP), feed intake (CR) and feed conversion ratio (CA) were evaluated. In the digestibility assay, 21 animals were used. The total dry matter (CDMS), crude protein (CDPB), gross energy (EB), neutral detergent fiber (CDFDN) and acid detergent fiber (CDFDA) coefficients were evaluated. There was no significant difference for any of the performance parameters studied (P > 0.05). The digestibility results showed higher CDPB and CDFDN in the corn diet (P <0.05), with no differences between the other parameters studied. Low tannin sorghum can be used in rabbit growth diets at substitution levels of 50% or 100% of maize participation without impairing zootechnical performance and digestibility.(AU)

Initial renal histology and early response predict outcomes of Brazilian lupus nephritis patients.

OBJECTIVE: We analyzed baseline and follow-up characteristics related to poorer renal outcomes in a Brazilian cohort of admixture race patients with lupus nephritis. METHODS: Overall, 280 outpatients with a diagnosis of systemic lupus erythematosus and previous kidney biopsy of lupus nephritis were recruited from August 2015 to December 2018 and had baseline laboratory and histologic data retrospectively analyzed; patients were then followed-up and data were recorded. The main outcome measure was the estimated glomerular filtration rate at last follow-up. Secondary analyses assessed the impact of initial kidney histology and treatment in long-term kidney survival. RESULTS: Median duration of lupus nephritis was 60 months (interquartile range: 27-120); 40 (14.3%) patients presented progressive chronic kidney disease (estimated glomerular filtration rate <30 and ≥10 ml/min/1.73 m2) or end-stage kidney disease at last visit. Adjusted logistic regression analysis showed that class IV lupus nephritis (odds ratio 14.91; 95% confidence interval 1.77-125.99; p = 0.01) and interstitial fibrosis ≥25% at initial biopsy (odds ratio 5.87; 95% confidence interval 1.32-26.16; p = 0.02), lack of complete or partial response at 12 months (odds ratio 16.3; 95% confidence interval 3.74-71.43; p < 0.001), and a second renal flare (odds ratio 4.49; 95% confidence interval 1.10-18.44; p = 0.04) were predictors of progressive chronic kidney disease. In a Kaplan-Meier survival curve we found that class IV lupus nephritis and interstitial fibrosis ≥25% were significantly associated with end-stage kidney disease throughout follow-up (hazard ratio 2.96; 95% confidence interval 1.3-7.0; p = 0.036 and hazard ratio 4.96; 95% confidence interval 1.9-12.9; p < 0.0001, respectively). CONCLUSION: In this large cohort of admixture race patients, class IV lupus nephritis and chronic interstitial damage at initial renal biopsy together with non-response after 1 year of therapy and relapse were associated with worse long-term renal outcomes.

Back and neck pain prevalence and their association with physical inactivity domains in adolescents.

PURPOSE: Back pain affects people of all ages. This may be associated with physical inactivity, and in the case of physical activity in different domains, the relationship with back pain is not clear in the literature. The aim of this study was to estimate the prevalence of low back and neck pain and investigate their association in different domains of physical inactivity. METHODS: 1011 randomly selected students participated in this study. Neck and back pain were assessed using the Nordic questionnaire, whereas the Baecke Physical Activity questionnaire was used to measure physical activity domains. Separate Binary Logistic Regression models were performed to investigate the association of physical activity domains with neck or back pain. RESULTS: 17.4% of the students reported cervical pain, while 18.0% reported low back pain. Older adolescents had a higher prevalence of cervical pain (24.4%) than younger adolescents (11.9%) (p value <0.001), as well as lumbar pain, being 25.1% in older adolescents and 12.4% in younger (p value <0.001). Adolescents physically inactive in the school environment were less likely to have pain in the cervical region [OR 0.67 (0.44-0.99)] or back pain [OR 0.60 (0.40-0.91)]. Being inactive in occupational activities was associated with cervical pain [OR 1.49 (1.06-2.10)]. Being inactive in the sports environment presented a marginal relationship with pain in the cervical region [OR 1.41 (0.99-2.02)]. CONCLUSIONS: The prevalence of neck and low back pain was higher in older adolescents and physical inactivity in the sporting context and occupational activities could be a risk factor to increase the chances of back pain.

Fighting COVID-19

Abstract The current COVID-19 pandemic caused by the novel coronavirus (SARS-CoV2) poses a threat to global health owing to its high rate of spread and severe forms of respiratory infection. The lack of vaccines and antivirals prevents clinical strategies against the disease, creating an emerging need for the development of safe and effective treatments. Strategies for vaccine development include complete vaccines against viruses, subunits, and nucleic acids, but are still in their early stages. Studies carried out to date on possible SARS-CoV2 drug targets highlight glycoprotein S, Mpro (main protease or protease type 3C), and a member of the transmembrane serine protease II families (TMPRSS2). However, due to the pandemic state, priority is given to marketed drugs. These include chloroquine (CQ), hydroxychloroquine (HCQ), nitazoxanide, remdesivir, Lopinavir/ritonavir (LPV / r), in addition to treatment with convalescent plasma. But, therapeutic specific effects against SARS-CoV2 have not yet been verified. Most of the information obtained about treatment is based on preliminary and limited studies. We conclude that, at this time of emergency, the search for new therapies is more urgent due to the need to save lives. Thus, we point out as interesting targets for future more specific research: glycoprotein S, Mpro, and TMPRSS2.

Resumo A pandemia de COVID-19 causada pelo novo Coronavírus (SARS-CoV2) representa uma ameaça à saúde global devido à alta taxa de disseminação e formas graves de infecção respiratória. A falta de vacinas e antivirais específicos dificultam as estratégias clínicas de controle da doença, criando a necessidade urgente do desenvolvimento de tratamentos seguros e eficazes. Com relação as estratégias para o desenvolvimento de vacinas, incluem-se: aquelas com o vírus completo, subunidades e ácidos nucléicos, mas estas ainda estão em estágios iniciais. Já sobre os estudos realizados até o momento buscando novos alvos terapêuticos contra o SARS-CoV2, destacam a glicoproteína S; Mpro (principal protease ou protease tipo 3C) e um membro da família transmembrana serina protease II (TMPRSS2). No entanto, devido ao estado pandêmico, tem sido dada prioridade aos medicamentos comercializados. Estes incluem a cloroquina (CQ); hidroxicloroquina (HCQ); nitazoxanida; remdesivir; Lopinavir / ritonavir (LPV/r); além do tratamento com plasma de pacientes curados. Porém, ainda não há uma estratégia terapêutica contra o SARS-CoV2 totalmente eficaz, e a maioria das informações obtidas sobre o tratamento é baseada em estudos preliminares e limitados. Concluímos então que, neste momento de emergência, a busca por novas terapias é algo urgente devido à necessidade de salvar vidas. Assim finalizamos sugerindo como alvos interessantes para futuras pesquisas específicas: a glicoproteína S, Mpro e o TMPRSS2.

In vitro activity of essential oils of free and nanostructured Melaleuca alternifolia and of terpinen-4-ol on eggs and larvae of Haemonchus contortus.

Haemonchus contortus is one of the major gastrointestinal nematodes responsible for significant economic and production losses of sheep. Diseases caused by this species lack effective anthelmintic products, and the search for new compounds to replace synthetic anthelmintics has been extensive. The present investigation assesses the in vitro activity of the essential oil of melaleuca (Melaleuca alternifolia), both free (TTO) and nanostructured (nanoTTO), and terpinen-4-ol (terp-4-ol) on eggs and larvae of H. contortus. Tests of egg hatching (EHT) and inhibition of larval migration (LMIT) were used to assess the in vitro efficacy of TTO, nanoTTO and terp-4-ol. Using EHT, at a concentration of 3.5 mg/ml, 100% inhibition occurred using TTO and terp-4-ol, with LC50 values of 0.43 and 0.63 mg/ml, and LC90 values of 1.75 mg/ml and 3.12 mg/ml, respectively. NanoTTO had lower activity, with 82.6% inhibition at the same concentration. Using LMIT, TTO and nanoTTO had a similar activity with 88.0% and 84.8% inhibition, respectively, at a concentration of 56 mg/ml. Terp-4-ol had a greater effect on larvae, with 85.7% inhibition at a concentration of 56 mg/ml and 82.4% at 3.5 mg/ml, demonstrating high activity at the lowest concentration tested. Therefore, the results indicate that all substances tested showed ovicidal and larvicidal activity against H. contortus. TTO, terp-4-ol and, mainly, nanoTTO may be targeted in in vivo studies, besides being a promising line of research into the control and treatment of veterinary important helminths.

Trypanocidal activity of free and nanoencapsulated curcumin on Trypanosoma evansi.

This study aimed to evaluate in vitro and in vivo trypanocidal activity of free and nanoencapsulated curcumin against Trypanosoma evansi. In vitro efficacy of free curcumin (CURC) and curcumin-loaded in lipid-core nanocapsules (C-LNCs) was evaluated to verify their lethal effect on T. evansi. To perform the in vivo tests, T. evansi-infected animals were treated with CURC (10 and 100 mg kg(-1), intraperitoneally [i.p.]) and C-LNCs (10 mg kg(-1), i.p.) during 6 days, with the results showing that these treatments significantly attenuated the parasitaemia. Infected untreated rats showed protein peroxidation and an increase of nitrites/nitrates, whereas animals treated with curcumin showed a reduction on these variables. As a result, the activity of antioxidant enzymes (superoxide dismutase and catalase) differs between groups (P<0.05). Infected animals and treated with CURC exhibited a reduction in the levels of alanine aminotransferase and creatinine, when compared with the positive control group. The use of curcumin in vitro resulted in a better parasitaemia control, an antioxidant activity and a protective effect on liver and kidney functions of T. evansi-infected adult male Wistar rats.

Association between the epidermal growth factor gene polymorphism and endometriosis in women from Brazil.

The aim of this study was to verify the association between the epidermal growth factor (EGF) +61 G/A polymorphism and the susceptibility to endometriosis using a case-control design study. The control group included fertile women without endometriosis and the case group included endometriosis patients. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to genotype the EGF +61 G/A polymorphism. Initially, a total of 184 individuals were analyzed. After matching by ethnicity, the control group was composed of 57 individuals, while the endometriosis group was composed of 57 patients. No statistically significant associations were observed between EGF +61 variants and the risk of endometriosis development (P>0.05). This is the first study correlating the EFG +61 G/A polymorphism and endometriosis in women from Brazil, and demonstrates that EFG +61 G/A is not associated with endometriosis susceptibility in Brazilian women.

Relationship between splenic sequestration and thrombocytopenia in Trypanosoma evansi infection in rats.

Trypanosoma evansi infections in domestic animals are characterized by anemia and thrombocytopenia. The cause of the platelets decrease is unknown, but researchers suggest that thrombocytopenia may result from damage of the bone marrow, reduced survival of platelets, auto-immune thrombocytopenia, disseminated intravascular coagulation and splenic sequestration. Some of these causes have already been tested by our research group and found to be unrelated. Therefore, this study has the objective of testing the hypothesis that splenic sequestration might be responsible for thrombocytopenia in T. evansi-infected rats. A total of 28 rats assigned to four groups were used in the experiment. Group A rats were splenectomized and infected with T. evansi, group B rats were infected with T. evansi, group C rats were splenectomized, but not infected and group D rats were normal controls. Five days post-infection all rats were anesthetized and blood was collected in order to measure the number of circulating platelets, fibrinogen levels, prothrombin time (PT) and activated partial thromboplastin time (aPTT). The spleens of groups B and D were weighed at necropsy. The infected animals (groups A and B) showed a significant reduction in platelets and increased PT and aPTT when compared to negative control groups (groups C and D). Animals from group A showed increased levels of fibrinogen. The mean weight of spleen differed between group B (2.62g) and group D (0.55g). It was concluded that there is no relationship between thrombocytopenia and splenic sequestration in infection by T. evansi.

Influência do processamento pós-colheita e armazenamento na composição química da droga vegetal e do óleo essencial de carqueja [Baccharis trimera (Less. ) DC. ] / Influence of post-harvest processing and storage on the chemical composition of drug and essential oil from "carqueja" [Baccharis trimera (Less. ) DC. ]

A carqueja-amarga [Baccharis trimera (Asteraceae)] é uma espécie originária do centro-sul da América do Sul. Análises qualitativas e quantitativas foram realizadas utilizando-se a técnica de CG-MS, para avaliar o efeito de diferentes formas de beneficiamento pós-colheita de drogas vegetais constituídas de partes aéreas de carqueja na composição química do óleo essencial, bem como verificar variações na composição quando conservado a -6ºC, durante 8 meses. O armazenamento da droga pulverizada reduziu significativamente o teor de óleo essencial, o que não aconteceu na droga fragmentada. Os teores dos constituintes majoritários espatulenol e ledol não foram influenciados pelo tratamento pós-colheita, embora tenham apresentado variações distintas redução nas concentrações de ledol e aumento nos teores de espatulenol. Verificou-se que as drogas fragmentadas podem ser armazenadas por até 12 meses e pulverizadas no momento da extração, não conferindo redução no teor de óleo essencial, nem dos constituintes químicos. O armazenamento a -6ºC por até oito meses, provocou variações quantitativas em alguns constituintes minoritários, tais como a-guaieno, b-selineno, germacreno B e espatulenol.

"Carqueja-amarga" [Baccharis trimera (Asteraceae)] is a species from the central south of South America. Qualitative and quantitative analyses were performed using the technique gas chromatography coupled to mass spectrometry to evaluate the effect of different post-harvest processing forms of drugs constituted of parts of "carqueja" on the chemical composition of its essential oil. The variation in the chemical composition of the essential oil stored at -6ºC for up to eight months was also evaluated. Storage of powdered drug significantly reduced the essential oil content, which was not observed for fragmented drug. The concentration of the major constituents of "carqueja" essential oil, spathulenol and ledol, was not affected by the post-harvest treatment, although they presented distinct variations, with ledol concentrations reducing and spathulenol concentrations increasing. We found that fragmented drugs can be stored for up to 12 months and powdered at the moment of extraction, without reducing the concentration of the essential oil or its chemical constituents. Storage at -6ºC for eight months caused quantitative variations in some minor constituents of the essential oil such as a-guaiene, b-selinene, germacrene B and espathulenol.

Evaluation of Cidofovir (HPMPC, GS-504) against adenovirus type 5 infection in vitro and in a New Zealand rabbit ocular model.

The antiviral inhibitory activity of Cidofovir [1-[(S)-3-hydroxy-2-(phosphonomethoxy)propyl]cytosine dihydrate, HPMPC, GS-504] against adenovirus type 5 (Ad5) in the New Zealand rabbit ocular replication model was evaluated. The 50% inhibitory dose (ID50) of Cidofovir was determined to be 4.7-9.5 micrograms/ml against four adenoviruses (two Ad5, Ad8 and Ad14) by plaque reduction assay in A549 cells. Twenty-four New Zealand rabbits received intrastromal inoculation and topical application of 2 x 10(6) plaque-forming units (PFU) per eye of Ad5 McEwen, a clinical isolate. Cidofovir was administered topically at three different concentrations twice per day, beginning 16 h postinoculation and continuing for 20 consecutive days. The inhibitory effects were determined by measuring suppression of virus replication and by observation of the clinical effects. Compared to the placebo group, the 1% and 0.5% Cidofovir-treated groups showed significantly reduced Ad5 ocular titers, fewer days of viral shedding and less severe subepithelial opacities (P = 0.0001). The 1% Cidofovir group had the lowest humoral antibody titer against adenovirus antigens, but the difference was not significant (P = 0.24). Cidofovir proved to have potent antiviral activity against adenovirus replication and may have great promise for the treatment of adenovirus infection. Further investigation is recommended.

Effect of atropine and propranolol on retrieval enhancement by a novel experience or by injection of beta-endorphin prior to testing in rats.

Wistar rats were trained in step-down inhibitory avoidance and tested 24 h later. One h prior to testing they were exposed to an open field or to an open field with flashing light (OFL) for 2 min. The OFL-exposed group showed retrieval enhancement for the avoidance task. This effect was mimicked by an injection of beta-endorphin (2.0 micrograms/kg) 1 h prior to testing, and both effects were blocked by the concomitant administration of naloxone (0.8 mg/kg, ip). Propranolol (2.0 mg/kg, ip) and atropine (0.5 mg/kg, ip) injected 6 min before the test completely blocked the retrieval-enhancing effect of both beta-endorphin and OFL. These results suggest that: 1) in rats, novel experiences may induce retrieval enhancement provided they are alerting; 2) the retrieval-enhancing effect of pre-testing exposure to OFL is probably due to activation of the brain beta-endorphin system which triggers late beta-noradrenergic and cholinergic mechanisms acting at the moment of retrieval.

Beta-endorphin and electroconvulsive shock alter the retrieval of two avoidance tasks when given after the first, but not the second, training session.

1. Rats were submitted to three consecutive sessions, one session per day, of two-way active avoidance or of step-down inhibitory avoidance, and received 1 microgram/kg beta-endorphin intraperitoneally or an electroconvulsive shock immediately after the first or after the second training session. 2. Administration of either treatment after the first session caused a reduction of performance in the second session in both tasks. There was no impairment of performance in the third session. 3. Administration of either treatment after the second session did not affect performance during the third session. 4. Therefore the effect of beta-endorphin and of electroconvulsive shock on active and inhibitory avoidance performance was expressed only when treatments were administered after the first, i.e., novel, training experience. We suggest this effect is on mechanisms acting on retrieval, since the retention performances of all groups for the third session were identical.