102 research outputs found
ETHOLOGICAL ANALYSIS OF MOTHER-PUP INTERACTIONS AND OTHER BEHAVIORAL REACTIONS IN RATS: EFFECTS OF MALNUTRITION AND TACTILE STIMULATION OF THE PUPS
Mother-pup interaction, as well as other behavioral reactions were studied during the lactation period in 24 litters of Wistar rats and their dams fed either a 16% (control - C; 12 litters) or a 6% (malnourished - M; 12 litters) protein diet. The diets were isocaloric. Throughout lactation there was a 36.4% weight loss of M dams and a 63% body weight deficit in the M pups when compared to control pups. During this period, half of the litters were exposed daily to additional tactile stimulation (CS or MS), while the other half were submitted to normal rearing conditions (CN or MN). The tactile stimulation of pups (handling) consisted of holding the animal in one hand and gently touching the dorsal part of the animal's body with the fingers for 3 min. A special camera and a time-lapse video were used to record litter behavior in their home cages. Starting at 6 p.m. and ending at 6 a.m., on days 3, 6, 12, 15, 18 and 21 of lactation, photos were taken at 4-s intervals. An increase in the frequency (154.88 ± 16.19) and duration (455.86 ± 18.05 min) of suckling was observed throughout the lactation period in all groups compared to birth day (frequency 24.88 ± 2.37 and duration 376.76 ± 21.01 min), but the frequency was higher in the C (84.96 ± 8.52) than in the M group (43.13 ± 4.37); however, the M group (470.2 ± 11.87 min) spent more time suckling as compared with the C group (393.67 ± 13.09 min). The M dams showed a decreased frequency of resting position throughout the lactation period (6.5 ± 2.48) compared to birth day (25.42 ± 7.74). Pups from the C group were more frequently observed separated (73.02 ± 4.38) and interacting (258.99 ± 20.61) more with their mothers than the M pups (separated 66.94 ± 5.5 and interacting 165.72 ± 12.05). Tactile stimulation did not interact with diet condition, showing that the kind of stimulation used in the present study did not lead to recovery from the changes induced by protein malnutrition. The changes in mother-pup interaction produced by protein malnutrition of both may represent retardation in neuromotor development and a higher dependence of the pups on their mothers. These changes may represent an important means of energy saving and heat maintenance in malnourished pups. Keywords: protein malnutrition, tactile stimulation, mother-pup interaction.
EFFECTS OF DIFFERENT LEVELS OF PROTEIN AND ENVIRONMENTAL STIMULATION ON THE BEHAVIOR OF YOUG RATS TESTED IN THE ELEVATED PLUS-MAZE
The interaction between the effects of different levels of protein malnutrition and environmental stimulation was investigated in young male rats in the elevated plus-maze (EPM). Litters (dam plus 6 male and 2 female pups) were fed a 16% (Control: C), 10% (Malnourished: M10) or 6% (Malnourished: M6) protein diet. Half of the litters were daily exposed to additional stimulation (CS, MS10 or MS6), while the other half was maintained in normal rearing conditions (CN, MN10 or MN6). The stimulation (handling) consisted of holding the rat in one hand and gently touching the dorsal part of the body with the fingers for3 min. On the 22nd day of life (weaning), two male pups from each group were tested in the plus-maze. Two male pups continued to receive the same diet their mothers, and other two were fed a non-purified lab chow diet until 35 days of age when they were tested in the plus-maze (LN, LS, LN10, LS10, LN6 and LS6 groups). Results showed that environmental simulation increased open arms exploration both at 22 and 35 days of age, indicating an anxiolytic effect of this procedure. Younger rats (22 days of age) explored significantly more the open arms of the maze as compared with older rats (35 days of age), indicating an increase in anxiety with age. M6 animals showed significantly higher percentages of open arm entries and less frequent attempts to enter open arms in the maze as compared with C and M10 animals. These results suggest that even a short period of protein deficiency can produce alterations in the emotional response of rats in the elevated plus-maze. In addition, the data demonstrated that protein deficiency more severe than 10% is necessary to produce behavior alterations in the EPM test. Keywords: Age, Anxiety, Environmental stimulation, Impulsiveness, Plus-maze test, Protein malnutrition levels.
Electronic transference assessment of the redox processes at carbon electrodes coated with Geobacter sulfurreducens that grown at different temperatures
In the present study, the kinetic parameters of redox
reactions and the proteomic profiles of Geobacter
sulfurreducens grown at different temperatures (25 ºC
and 37 ºC) were evaluated. Oxidation peaks with
different potentials and current intensities were observed
for both cultures. Also, the outer membrane proteins of
the bacteria at the two temperatures revealed different
profiles that can be responsible for different redox
centers. Thus, G. sulfurreducens that grows at different
temperatures may express different cytochromes in the
external membrane
Influence of the temperature in the electronic transfer mechanism of Geobacter sulfurreducens
Geobacter species are important in the reduction of metals (e.g. Fe, Mn) in soils and sediments and constitute one of the most effective microorganisms known to use electrodes as the sole electron acceptor in microbial fuel cells to generate electricity.
G. sulfurreducens transfers electrons directly to the electrode from different external membrane cytochromes. Each cytochrome is associated with a range of electrical potentials, being energetically more favourable than some others. Different growth conditions of the bacteria, such as temperature, may influence the prevalence of certain cytochromes in the external membrane. The aim of this work was to evaluate the difference in the electronic transfer mechanisms in G. sulfurreducens that growth at different temperatures (25 ºC and 37 ºC).
The cyclic voltammetry is an electrochemical technique that can be used to assess the redox reactions between bacteria and electrode and was used to compare different cultures of G. sulfurreducens (Figure 1). With these studies it can be concluded that at different temperatures the oxidation peaks potentials and current intensities were different. The current intensity increased in bacteria that growth at higher temperatures but the potential of the oxidation peak was more anodic, thus more energy was required. The oxidation reaction was limited by diffusion. An irreversible electronic transfer is noticed. At 25ºC the kinetic of the reaction had a mixed control and charge transfer was reversible for lower sweep scan rates.
SDS-Page was used to characterize the membrane protein complexes. The membrane proteins extracted from bacteria that growth at different temperatures migrated differently in the gel, revealing proteins of different molecular weights. G. sulfurreducens may provide an interesting model for structural comparison of proteins since the two samples revealed different profiles. The separation of the membrane proteins was obtained from sucrose gradient centrifugation and 2D electrophoresis. The complete proteins characterization is already being developed in our laboratories
Kinetic study of the redox processes in carbon electrodes with Geobacter sulfurreducens at different growth temperatures
Geobacter sulfurreducens is a bacteria that can transfer electrons directly to the electrode from different external membrane cytochromes. Each cytochrome is associated with a range of electrical potentials, being energetically more favourable than some others. Different growth conditions of the bacteria, such as temperature, may influence the prevalence of certain cytochromes in the external membrane. The aim of this work was to evaluate the difference in the kinetic parameters of the electronic transfer in G. sulfurreducens that growth at different temperatures (25 ºC and 37 ºC).
The cyclic voltammetry is an electrochemical technique that can be used to assess the redox reactions between bacteria and electrode and was used to compare different cultures of G. sulfurreducens. With these studies it can be concluded that at different temperatures the oxidation peaks potentials and current intensities were different. The current intensity increased in bacteria that growth at higher temperatures but the potential of the oxidation peak was more anodic, thus more energy was required. The oxidation reaction was limited by diffusion. An irreversible electronic transfer is noticed. At 25ºC the kinetic of the reaction had a mixed control and charge transfer was reversible for lower sweep scan rates.
SDS-Page was used to characterize the membrane protein complexes. The membrane proteins extracted from bacteria that growth at different temperatures migrated differently in the gel, revealing proteins of different molecular weights. G. sulfurreducens may provide an interesting model for structural comparison of proteins since the two samples revealed different profiles. The separation of the membrane proteins was obtained from sucrose gradient centrifugation and 2D electrophoresis. The complete proteins characterization is already being developed in our laboratories
Utilização de chuveiros na sala pré-ordenha e sua influência na produtividade de búfalas da raça Murrah (Bubalus bubalis).
O estudo foi realizado com 64 búfalas, em dois tratamentos (1 e 2), durante seis dias. No primeiro, antes da ordenha, os animais permaneceram 1h em sala de espera com acesso ao chuveiro No segundo, os animais não tiveram acesso ao chuveiro. Foram registrados Índice de Temperatura de Globo e Umidade (ITGU) e a Umidade Relativa (UR) das salas de ordenha e de espera, Temperatura de Corpo (TC), Frequência Respiratória (FR), Reatividade (REAT), Nível de Estresse (NEST) e a Produção Diária de Leite (PL). Os dados foram analisados com o auxílio do programa SAS. O efeito da FR não foi significativo (P>0,57) sobre a PL. Não houve diferença significativa na PL para a REAT. O NEST foi o mesmo nos dois tratamentos. As regressões da característica (PL_AJ) sobre ITGU Interno (ITGU_I), ITGU Externo (ITGU_E), TC e UR não foram significativas (P>0,12). No tratamento 2 foram observados maior número de animais em classes de estresse, verificou-se que o tratamento 1 possibilitou a mudança ( alguns animais) da zona de alerta ou estresse para a zona de conforto térmico em relação ao ITGU_I. No tratamento 2, todos os animais estavam em estresse térmico. Os animais submetidos ao estresse calórico em ambas as situações utilizaram com eficiência o seu sistema termorregulador, sem interferir na produção de leite
Removal of tetracycline from contaminated water by Moringa oleifera seed preparations
The aim of this study was to evaluate tetracycline antibiotic (TA) removal from contaminated water by Moringa oleifera seed preparations. The composition of synthetic water approximate river natural contaminated water and TA simulated its presence as an emerging pollutant. Interactions between TA and protein preparations (extract; fraction and lectin) were also evaluated. TA was determined by solid phase extraction followed by high performance liquid chromatography - mass spectrometry. Moringa extract and flour removed TA from water. Extract removed TA in all concentrations and better removal (40%) was obtained with 40 mg L1; seed flour (particles 5 mm (0.50 g L1) removed 55% of antibiotic. Interactions between TA and seed preparations were assayed by haemagglutinating activity (HA). Specific HA (SHA) of extract (pH 7) was abolished with tetracycline (5 mg L1); fraction (75%) and lectin HA (97%) were inhibited with TA. Extract SHA decreased by 75% at pH 8. Zeta potential (ZP) of extract 700 mg L1 and tetracycline 50 mg L1 , pH range 5 to 8, showed different results. Extract ZP was more negative (10.73 mV to 16.00 mV) than tetracycline ZP (0.27 mV to 20.15 mV); ZP difference was greater in pH 8. The focus of this study was achieved since moringa preparations removed TA from water and compounds interacting with tetracycline involved at least lectin binding sites. This is a natural process, which do not promote environmental damage.This work was supported by the Fundacao para a Ciencia e a Tecnologia and POPH/FSE under Grant SFRH/BPD/37349/2007; the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for fellowships (PMGP and LCBBC); the authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 [FCOMP-01-0124-FEDER-027462] and the project 'BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes,' REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER
Multicenter double blind trial of autologous bone marrow mononuclear cell transplantation through intracoronary injection post acute myocardium infarction – MiHeart/AMI study
Background: Myocardial infarction remains as a major cause of mortality worldwide and a high rate of survivors develop heart failure as a sequel, resulting in a high morbidity and elevated expenditures for health system resources. We have designed a multicenter trial to test for the efficacy of autologous bone marrow (ABM) mononuclear cell (MC) transplantation in this subgroup of patients. The main hypothesis to be tested is that treated patients will have a significantly higher ejection fraction (EF) improvement after 6 months than controls. Methods: A sample of 300 patients admitted with ST elevation acute myocardial infarction (STEMI) and left ventricle (LV) systolic dysfunction, and submitted to successful mechanical or chemical recanalization of the infarct-related coronary artery will be selected for inclusion and randomized to either treated or control group in a double blind manner. The former group will receive 100 x 106 MC suspended in saline with 5% autologous serum in the culprit vessel, while the latter will receive placebo (saline with 5% autologous serum). Implications: Many phase I/II clinical trials using cell therapy for STEMI have been reported, demonstrating that cell transplantation is safe and may lead to better preserved LV function. Patients with high risk to develop systolic dysfunction have the potential to benefit more. Larger randomized, double blind and controlled trials to test for the efficacy of cell therapies in patients with high risk for developing heart failure are required.Brazilian Ministry of Science and Technology (MCT)/The Financing Agency for Studies and Projects (FINEP
A legislação ambiental como foco de conflitos: uma análise a partir das representações sociais da natureza dos pequenos agricultores em Minas Gerais, Brasil
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