Peripheral brain-derived neurotrophic factor (BDNF) as a biomarker in bipolar disorder: a meta-analysis of 52 studies

Background The neurotrophic hypothesis postulates that mood disorders such as bipolar disorder (BD) are associated with a lower expression of brain-derived neurotrophic factor (BDNF). However, its role in peripheral blood as a biomarker of disease activity and of stage for BD, transcending pathophysiology, is still disputed. In the last few years an increasing number of clinical studies assessing BDNF in serum and plasma have been published. Therefore, it is now possible to analyse the association between BDNF levels and the severity of affective symptoms in BD as well as the effects of acute drug treatment of mood episodes on BDNF levels. Methods We conducted a systematic review and meta-analysis of all studies on serum and plasma BDNF levels in bipolar disorder. Results Through a series of meta-analyses including a total of 52 studies with 6,481 participants, we show that, compared to healthy controls, peripheral BDNF levels are reduced to the same extent in manic (Hedges' g = −0.57, P = 0.010) and depressive (Hedges' g = −0.93, P = 0.001) episodes, while BDNF levels are not significantly altered in euthymia. In meta-regression analyses, BDNF levels additionally negatively correlate with the severity of both manic and depressive symptoms. We found no evidence for a significant impact of illness duration on BDNF levels. In addition, in plasma, but not serum, peripheral BDNF levels increase after the successful treatment of an acute mania episode, but not of a depressive one. Conclusions In summary, our data suggest that peripheral BDNF levels, more clearly in plasma than in serum, is a potential biomarker of disease activity in BD, but not a biomarker of stage. We suggest that peripheral BDNF may, in future, be used as a part of a blood protein composite measure to assess disease activity in BD

Systemic and reproductive toxicity induced by Parkia platycephala ethanolic extract in female Wistar rats

The present study was conducted to evaluate the toxicity of the ethanolic extract of leaves of Parkia platycephala Benth., Fabaceae, on systemic and reproductive parameters. In toxicity on the estrous cycle, four groups of not-pregnant Wistar rats received distilled water and the doses 250, 500 and 1000 mg.kg-1 of plant extract for thirty days, at the end of which they were examined as to the frequency of their phases. The systemic toxicity was assessed through the consumption of water and food and by measuring body mass. After the extract was administered, serum AST, ALT, ALP, bilirubin (total, direct and indirect), urea and creatinine were dosed. The evaluation of the organs (brain, heart, hypophysis, adrenal glands, liver, spleen, uterus and ovaries) in their macroscopic aspects, relative and absolute masses and histological structure showed that the plant extract induced a decrease of water and food consumption and of body mass. It caused an increase in the luteal phase and a decrease in the follicular phase of the estrous cycle and rose serum alkaline phosphatase levels.The data exhibit systemic and reproductive toxicity induced by plant extract in female Wistar rats

Peripheral brain-derived neurotrophic factor (BDNF) as a biomarker in bipolar disorder: a meta-analysis of 52 studies

Background The neurotrophic hypothesis postulates that mood disorders such as bipolar disorder (BD) are associated with a lower expression of brain-derived neurotrophic factor (BDNF). However, its role in peripheral blood as a biomarker of disease activity and of stage for BD, transcending pathophysiology, is still disputed. In the last few years an increasing number of clinical studies assessing BDNF in serum and plasma have been published. Therefore, it is now possible to analyse the association between BDNF levels and the severity of affective symptoms in BD as well as the effects of acute drug treatment of mood episodes on BDNF levels. Methods We conducted a systematic review and meta-analysis of all studies on serum and plasma BDNF levels in bipolar disorder. Results Through a series of meta-analyses including a total of 52 studies with 6,481 participants, we show that, compared to healthy controls, peripheral BDNF levels are reduced to the same extent in manic (Hedges' g = −0.57, P = 0.010) and depressive (Hedges' g = −0.93, P = 0.001) episodes, while BDNF levels are not significantly altered in euthymia. In meta-regression analyses, BDNF levels additionally negatively correlate with the severity of both manic and depressive symptoms. We found no evidence for a significant impact of illness duration on BDNF levels. In addition, in plasma, but not serum, peripheral BDNF levels increase after the successful treatment of an acute mania episode, but not of a depressive one. Conclusions In summary, our data suggest that peripheral BDNF levels, more clearly in plasma than in serum, is a potential biomarker of disease activity in BD, but not a biomarker of stage. We suggest that peripheral BDNF may, in future, be used as a part of a blood protein composite measure to assess disease activity in BD

Desempenho e excreção de nitrogênio de leitões dos 9 aos 25 kg alimentados com dietas com diferentes níveis de lisina digestível e proteína bruta Performance and nitrogen excretion for pigs from 9 to 25 kg submitted to the diets with different levels of digestible lysine and crude protein

Dois experimentos foram conduzidos para avaliar níveis de PB e lisina digestível (LISD) na dieta sobre o desempenho e a excreção de nitrogênio (N) de leitões na fase inicial. No experimento 1, 80 suínos machos castrados e fêmeas (peso inicial de 9,1 &plusmn; 1,2 kg e final de 21,5 &plusmn; 4,8 kg), mestiços Landrace &times; Large White, foram distribuídos em blocos casualizados em esquema fatorial 2 &times; 4, composto de dois níveis de PB (16 e 18%) e quatro níveis de LISD (0,7; 0,9; 1,1 e 1,3%) com cinco repetições e dois animais por unidade experimental durante 35 dias. Foram avaliados o ganho de peso médio diário (GPMD), o consumo médio diário de ração (CMDR) e a conversão alimentar (CA). No experimento 2, 32 suínos machos castrados (25,0 &plusmn; 1,3 kg), provenientes do experimento 1 foram alojados individualmente em gaiolas próprias para estudos de metabolismo (unidade experimental) durante 11 dias para determinação dos teores de N ingerido (NI), N nas fezes e N na urina. As rações foram formuladas com milho, farelo de soja e leite em pó modificado e suplementadas com vitaminas e minerais. Os aminoácidos metionina e treonina foram corrigidos de acordo com os níveis de lisina, segundo o conceito de proteína ideal. Não houve efeito da interação LISD &times; PB sobre nenhuma variável estudada. Os níveis de LISD tiveram efeito quadrático sobre o GMDR e a CA, que foram melhores nos animais alimentados com as dietas com níveis de 1,04 e 1,09% de PB. Os níveis de N nas fezes sofreram efeito linear crescente dos níveis de LISD e PB, enquanto os níveis de N na urina foram afetados de forma quadrática pelos níveis de LISD, com melhor resultado no nível de 1,03% LISD na ração. O CMDR e o nível de N nas fezes não foram influenciados pelos níveis de LISD e PB. O nível de 1,05% LISD em dietas com 16 e 18% PB proporciona melhor desempenho e menor excreção de N nos dejetos de suínos.<br>Two experiments were conducted to evaluate dietary levels of crude protein (CP) and digestible lysine (LYSD) on the performance and nitrogen (N) excretion of piglets in the initial phase. In experiment 1, 80 barrows and females (initial weight of the 9.1 kg &plusmn; 1.2 kg and final weight of the 21.5 &plusmn; 4.8 kg), crossbred (Landrace x Large White), were distributed to a randomized blocks in factorial scheme 2 x 4 (two levels of CP 16 and 18% - and four levels of LYSD (0.7; 0.9; 1.1 and 1.3%) with five replications and two animals per experimental unit, during 35 days. The average daily weight gain (ADG), average daily feed intake (ADFI) and feed:gain ratio (F:G) were evaluated. In experiment 2, 32 barrows (25.0 &plusmn; 1.3 kg), from experiment I, were individually allotted in metabolic cages (experimental unit), during 11 days, to evaluate the ingested N, N in feces and N in urine . The diets were formulated with corn, soybean meal and modified powder milk, supplemented with vitamins and minerals. The amino acids methionine and threonine were corrected in function of the lysine levels, following the ideal protein concept. No interaction LYSD x CP was observed for neither studied variable. Average daily gain and F:G showed a quadratic effect for the LYSD levels and were better in the animals fed diets with levels of 1.04 and 1.09%, respectively. The levels of N in the fezes showed crescent linear effect with the LYSD and CP levels, while the N levels in the urine showed quadratic effect with LYSD levels, with lower excretion for the level of 1.03% in the ration. No influence was observed for LYSD and CP level on ADFI and N in fezes. The level of 1.05% LYSD in diets with 16 and 18% CP provide best performance and lower excretion of de N in dejects of the swine