Orientador: Iveraldo dos Santos Dutra / Banca: Julio Cesar de Freitas / Banca: Tereza Cristina Cardoso da Silva / Resumo: A diarréia neonatal é uma das principais causas de perdas na bovinocultura. O Clostridium perfringens é um enteropatógeno amplamente distribuído na natureza e responsável por várias doenças nos animais, dentre elas a diarréia neonatal. Foram examinadas 141 amostras fecais de bezerros com diarréia e 129 amostras de animais sadios, com até 28 dias de idade e pertencentes a três rebanhos distintos. Do cultivo bacteriológico em anaerobiose foi possível isolar 36,2% e 30,2% amostras suspeitas de Clostridium perfringens dos animais enfermos e dos animais sadios, respectivamente. A genotipagem bacteriana foi efetuada empregando-se a técnica de PCR multiplex com os primers dos genes codificadores das toxinas alfa (cpa), beta (cpb), épsilon (etx), iota (itxA), enterotoxina (cpe) e toxina beta2 (cpb2). Dentre as amostras isoladas, 17/51 (33,3%) e 17/39 (43,6%) dos animais com diarréia e sadios, respectivamente, amplificaram um ou mais genes codificadores das toxinas de C. perfringens. Dos bezerros com diarréia, quatorze apresentaram somente o gene cpa (tipo A), um apresentou o cpa e cpb2 (tipo A beta2 positivo), um amplificou o cpa, itxA, e cpb2 (tipo E, beta2 positivo) e um amplificou o cpa, etx, itxA e cpb2 (tipo D e E, um ou ambos cpb2 positivo). Dentre os bezerros sadios, 10 eram exclusivamente tipo A, um era tipo A cpb2 positivo, dois eram tipo E, três eram tipo E cpb2 positivo e um era tipo D e E cpb2 positivo. Não houve correlação entre a genotipagem dos genes codificadores das toxinas de Clostridium perfringens e a presença de diarréia neonatal nos bezerros. / Abstract: Neonatal diarrhea is one of the main causes of losses in cattle herds. Clostridium perfringens is a widespread enteropathogen, and is responsible for many animal diseases such as bovine neonatal diarrhea. Fecal samples from 141 diarrheic calves and 129 healthy calves, aged up to 28 days and belonging to three herds were examined. Rates of culture positivity were 36.2% and 30.2% for diarrheic and nondiarrheic calves, respectively. Multiple isolates from primary isolation plates were subjected to simultaneous genotyping by multiplex PCR, with primers amplifying fragments of alpha (cpa), beta (cpb), epsilon (etx), iota (itxA), enterotoxin (cpe) and beta2 (cpb2) toxinencoding genes. Only 17/51 (33.3%) and 17/39 (43.6%) of these mixtures from diarrheic and nondiarrheic calves, respectively, yielded genotype information, suggesting that this may not be a viable approach to genotyping of isolates. Fourteen isolate mixtures from animals with diarrhea had only cpa (type A), one had cpa and cpb2 (type A beta2 positive), one with cpa, itxA, and cpb2 (type E, beta2 positive), and one with cpa, etx, itxA, and cpb2 (Types D and E, one or both cpb2 positive). Among 17 isolate mixtures from healthy calves, 10 were exclusively type A, one was type A cpb2 positive, two were type E, three were type E cpb2 positive, and one was types D and E cpb2 positive. There was no correlation between isolation of a given toxin type and the presence of diarrhea. / Mestre

Durante as duas primeiras semanas após o nascimento, os ratos mostram respostas neuroendócrinas diminuídas ao estresse, caracterizando uma fase conhecida como o “período hiporresponsivo ao estresse”. No entanto, é um período sensível do desenvolvimento do sistema nervoso, no qual o animal é suscetível a eventos ambientais, tais como estresse e qualidade do cuidado materno, os quais podem ter efeitos duradouros no indivíduo. No presente estudo, foram investigados os níveis plasmáticos de corticosterona e ocitocina e a atividade monoaminérgica central em ratos neonatos submetidos ao estresse por frio. Também foram investigadas as possíveis influências do gênero e do cuidado materno recebido. No final do 1º dia pós-parto (P0), 60 ratas Wistar tiveram suas ninhadas padronizados em 8 filhotes. Do P1 ao P10, as mães tiveram seus comportamentos maternos analisados de acordo com trabalhos anteriores, nos quais o comportamento de lambida foi tido como uma medida de qualidade de cuidado materno (freqüência média de lambida da população = 5,52 ± 0,19). As mães apresentando as menores e as maiores freqüências de lambida foram selecionadas como Pouco-Cuidadoras (média<4,18, n=12) e Muito- Cuidadoras (média>6,99, n=10), respectivamente. No P13, um par de filhotes foi removido da ninhada e imediatamente sacrificado por decapitação (grupo controle) e outros dois pares foram removidos da ninhada e colocados em um recipiente plástico dentro de uma câmara fria (0ºC, 6 min.), sendo sacrificados 15 e 30 min. após o término do estresse por frio. O sangue do tronco foi colhido para radioimunoensaio de corticosterona e ocitocina plasmáticas. Os encéfalos foram rapidamente removidos para dissecção dos hipotálamos e hipocampos que foram usados na análise das monoaminas e seus metabólitos na Cromatografia Líquida de Alta Performance. A ANOVA de três vias com Post Hoc de Duncan mostrou um efeito do estresse aumentando a corticosterona plasmática (p<0,001), comparada ao período pré-estresse (basal). As filhotes fêmeas de ambos os grupos e os filhotes machos e fêmeas Muito- Cuidados apresentaram níveis maiores de ocitocina plasmática (p<0,05 para ambos), comparados aos Pouco-Cuidados. O estresse também diminuiu a atividade da dopamina (p=0,05), comparado aos grupos controles. O efeito do cuidado materno foi também observado no hipocampo, cuja atividade serotonérgica foi maior em filhotes Muito- Cuidados (p=0,05), comparados a filhotes Pouco-Cuidados, independente do gênero. Conforme relatado anteriormente em outros trabalhos, o estresse aumenta a corticosterona plasmática em filhotes, mesmo no período hiporresponsivo. Os níveis plasmáticos aumentados de ocitocina na prole Muito-Cuidada estão de acordo com evidências a respeito do papel deste hormônio no apego mãe-filhote. A ocitocina aumentada em filhotes fêmeas mostra que diferenças hormonais quanto ao gênero já estão presentes no início da vida de roedores. Interessantemente, o estresse diminuiu a atividade dopaminérgica, o que está de acordo com resultados encontrados em certas áreas hipotalâmicas de animais adultos expostos ao frio. É sugerido que esse efeito seja devido à peculiaridade do estresse por frio, uma vez que as respostas monoaminérgicas podem variar dependendo do estressor usado. O hipocampo foi sensível ao cuidado materno, o qual já foi anteriormente indicado por ser uma importante estrutura encefálica cuja atividade é influenciada por diferentes qualidades de cuidado materno por meio da sinalização serotonérgica. / During the first two weeks after birth the rats show decreased neuroendocrine responses to stress, characterizing a stage known as “stress hyporesponsive period”. However, this is a neurodevelopmental sensitive period in which the animal is susceptible to environmental events, such as stress and the quality of maternal care, which may have long-term effects upon the individual. It was investigated plasma corticosterone and oxytocin, and central monoaminergic activity in neonatal rats submitted to cold stress. It was also investigated the possible influences of gender and maternal care received. In the end of 1° postpartum day (P0), the 60 Wistar dams had their litters culled to 8 pups. From P1 to P10, dams had their maternal behaviour analysed according to previous works, in which licking behaviour was taken as a measure of the quality of maternal care (population’s mean licking frequency= 5.52 ± 0.1863). Dams showing the lower and higher frequencies of licking were selected as Low Licking (mean<4.1814, n=12) and High Licking (mean>6.991, n=10), respectively. At P13, a pair of pups was removed from the litter and immediately sacrificed by decapitation (control group) and other two pairs were removed from the litter and placed in a plastic container inside a cold chamber (0ºC, 6 min), being sacrificed 15 and 30 min after the termination of the cold stress. Blood trunk was taken for plasma corticosterone and oxytocin radioimmunoassay. The brains were quickly removed for dissection of the hypothalami and hippocampi for monoamine and their metabolites High Performance Liquid Chromatography analysis. The three-way ANOVA with Duncan Post Hoc showed an effect of stress increasing plasma corticosterone (p<0.001) compared to the control group (basal situation). The female pups of both groups and High Licked male and female pups showed higher levels of plasma oxytocin (p<0.05 for both). The stress also decreased hypothalamic dopamine turnover (p=0.05) compared to the control groups. The maternal effect was also found in the hippocampus, whose serotonergic activitiy was increased in High Licked pups (p=0.05), independent of gender. As previously reported in other works, stress increases plasma corticosterone in the pups even in the stress hyporesponsive period. The increased plasma oxytocin levels in the High Licked offspring are according to evidences supporting the role of this hormone upon the mother-infant attachment. The increased oxytocin in female pups shows that hormonal gender differences are present in the early life of rodents. Interestingly, it was found that stress decreased the hypothalamic dopaminergic activity, which is according to results found in certain hypothalamic areas of adult animals exposed to cold. It is suggested that this is due to the peculiarity of cold stress, since the monoaminergic responses vary depending on the stressor used. The only central effect of maternal care was found in the hippocampus, which was previously found to be an important brain structure whose activity is influenced by different qualities of maternal care through serotonergic signaling.

Eventos que acontecem aos filhotes, tais como intervenções no ambiente ou alterações no comportamento maternal, durante o período neonatal induzem a alterações neuroendócrinas e comportamentais estáveis, percebidas já na infância e perduram na vida adulta do animal. O modelo de manipulação dos filhotes no período neonatal tem sido estudado com o objetivo de tentar compreender as alterações no ambiente perinatal e suas manifestações, visto que muitas patologias psicológicas podem ser desencadeadas neste período e se manifestar na vida adulta. A principal conseqüência da manipulação neonatal é uma redução da ansiedade a ambientes novos em ratos adultos. Logo após o nascimento, o sistema nervoso central (SNC) ainda está em formação e intervenções ocorridas no período neonatal afetam alguns sistemas neurais. Este trabalho teve como objetivo estudar o efeito da manipulação durante os primeiros dias de vida, em filhotes de rato e suas conseqüências em comportamentos sociais e em sistemas neurais relacionados à ocitocina e vasopressina. A ocitocina, um hormônio neuro-hipofisário cujo papel na reprodução é bem conhecido foi estudado neste trabalho porque tem funções importantes no SNC, principalmente em modular comportamentos, como sexual, social, afetivos e memória social. A vasopressina, conhecida por sua função na manutenção da osmolalidade, também é reconhecida por modular agressividade, o eixo hipotálamo-hipófise-supra-renal, comportamentos sexuais, memória e tem sido estudada em transtornos depressivos. Este estudo comparou vários parâmetros relacionados à produção e à liberação de ocitocina e vasopressina entre ratos manipulados e não-manipulados no período neonatal. Os resultados apresentados neste trabalho mostram uma reduzida interação social em ratos adultos. Ainda pôde-se observar aumento da agressividade nestes animais. Esse efeito comportamental aparentemente é dependente do sexo, pois somente foi detectado em machos. Também foi relatado um menor número de neurônios ocitocinérgicos e um aumento no número dos vasopressinérgicos no hipotálamo de ratos adultos, machos e fêmeas, que sofreram manipulação. Não foi demonstrada diferenças na liberação destes hormônios na resposta ao estresse, nem na expressão total de ocitocina e de vasopressina no núcleo paraventricular de ratos adultos. Entretanto, em filhotes machos e fêmeas, aos 10 dias de idade, pôde-se observar que a manipulação aumenta a secreção plasmática de ocitocina. Conclui-se assim, que, a manipulação no período neonatal interfere negativamente no estabelecimento de relações sociais na vida adulta, podendo ter como causa uma possível alteração nos sistemas ocitocinérgico e vasopressinérgico central nestes.

This study explores the opinions and experiences of East Tennessee State University (ETSU) male nursing students after they have completed their clinical rotations in obstetrics (OB). Participants are interviewed about their preconceptions and post-experience perspectives regarding the clinical rotation. After analyzing the interviews, the students’ perceptions appeared to be grounded in their perceived level of comfort with women’s health nursing. Themes include (1) preconceptions, (2) welcoming, (3) rejecting, and (4) culture.

Tese de mestrado. Engenharia Biomédica. Faculdade de Engenharia. Universidade do Porto, Instituto Nacional de Engenharia Biomédica. 2008

Thesis (MPH.) -- University of Limpopo, 2018 / Background: Pregnant women expect a normal pregnancy, a normal delivery and a healthy baby. Unfortunately, premature birth is a common occurrence; ithas some complications and causes death in developing countries. Mothers feel disappointed for not carrying their pregnancies to term and worry about the survival of their babies. Admission into neonatal intensive care unit increases chances of baby survival but has emotional impact on mothers, thus the need to explore their experiences. Objective: To explore the lived experiences of mothers regarding their first exposure to their premature babies admitted in neonatal intensive care unit. Methods: A qualitative and exploratory study using semi-structured interviews with purposively selected mothers was conducted. Interviews were conducted in English using an interview guide, audio recorded and continued until data saturation was reached, thus 8 mothers participated in the study. Field notes were collected. Voice recordings were transcribed verbatim and analysed thematically. An independent coder confirmed the findings. Results: Mothers experienced stress and anxiety, and felt neglected by health care workers. They felt the focus was on the baby alone and the mothers’ needs ignored, though others were happy that they were welcomed. Conclusions: Therefore, parents need support when their premature babies are admitted in neonatal an intensive care unit. Continuous update on conditions of their babies is also necessary. / AMREF Health Africa, and Limpopo Department of Health

Background: Extensive research has characterized the embryonic development of a four-chambered heart in mammals. After birth, mammalian cardiomyocytes undergo a transition characterized by a final cell cycle with nuclear division (karyokinesis) in the absence of cytoplasmic division (cytokinesis), generating mature binucleated cardiomyocytes. Downregulation of pro-proliferative signaling and epigenetic changes permanently ‘lock’ cardiomyocytes out of the cell cycle, and nearly all subsequent growth is accomplished via cellular hypertrophy. Before this transition, cardiomyocytes exhibit robust proliferative potential, but afterward are unable to divide. Rationale & Hypothesis: Recent evidence suggests that non-coding RNAs influence early neonatal cardiac development and hypertrophy. We hypothesize that transient expression of regulatory miRNAs may impact the neonatal heart’s transition from proliferation to hypertrophy. Results: Cardiac mRNA and miRNA were systematically analyzed using microarrays to identify targets that were transiently and significantly changing after birth. Through our analysis we identified three primary ontogenies significantly changing: metabolism, extracellular matrix remodeling, and cell cycle regulation. Global analysis of micro-RNA expression patterns during perinatal heart development identified miR-205 as a novel candidate for modulating cardiomyocyte maturation. We observed miR-205 expression undergoing a 20-fold increase from 1-day postpartum (1D) to 5D, returning to prenatal levels by 10D. It is expressed in cardiomyocytes of the epicardium, the primary location of fetal cardiomyocyte proliferation. MiR-205 targets two important cell cycle regulators: Pten phosphatase of the PI3K/AKT pathway, and Yap1 in the Hippo pathway. Both pathways have proven to be essential for proper heart development. Previous research showed that germline deletion of miR-205 results in death at 5D. To define its role in the heart, we generated an αMHC-Cre postnatal miR-205 cardiac-specific deletion mouse model. Systematic characterization of miR-205-/- hearts confirmed miR-205’s interaction with Pten and Yap1 by western blot and immunohistochemistry. Postnatal miR-205-/- hearts exhibit Hippo pathway dysregulation, increased cardiomyocyte number, more actively cycling cardiomyocytes beyond 7D, and no difference in binucleation. We also generated a DOX-inducible cardiac-specific miR-205 over-expression mouse model. Perinatal miR-205OE hearts expedited the transitional period, with more cardiomyocytes present at 5D and no difference at 14D. These hearts show increased Hippo signaling immediately after birth, suggesting compensatory mechanisms to ensure sufficient cardiomyocyte number. Conclusions: Our data strongly supports miR-205 as a regulator of cardiomyocyte maturation in the neonatal heart, by promoting the neonatal cardiomyocyte transition from hyperplastic to hypertrophic growth. In turn, miR-205’s antiproliferative properties originate in part from suppressing the expression of Pten and Yap1.

No description available.

The purpose of this study was to compare the Utah maternal questionnaire and birth certificate as they relate to the identification of hearing impairment in infants. Comparative data relating to rate of return, number of high risk infants, number of at risk infants, number of hearing impaired infants, false positive rates, and item analysis were obtained for both screening instruments. Tabulation of the results showed the birth certificate to be a better neonatal screening device of hearing impairment than the maternal questionnaire. The birth certificate maintained a low false positive rate and a high rate of identification of hearing impairment in infants.

The aims of this Thesis were to investigate early markers of neonatal sepsis and patient-factors affecting the pharmacokinetics and pharmacodynamics (PKPD) of aminoglycosides in the treatment of neonatal sepsis. A prospective cohort study of neonates commenced on gentamicin for suspected sepsis was performed between 1 July 2002 and 28 February 2007. Receiver operator characteristics (ROC) plots were used to assess potential markers of sepsis against culture positive sepsis. When sepsis was first suspected, the most promising tests were interleukin (IL) IL-12(p70) with an area under the curve (95% CI) for the ROC of 0.74 (0.63-0.86), and which (with a cut-off at 75 pg/mL) had a sensitivity (95% CI) of 28% (20-36%) and a specificity of 98% (96-100%). IL-10 had a sensitivity of 17% (10-23%) and a specificity of 99% (97-100%). Retrospective studies of neonates treated with gentamicin, amikacin and netilmicin for suspected sepsis were used to identify patient characteristics that affected aminoglycoside PKPD properties. Population PK modelling used NONMEM� v.5 to determine aminoglycoside clearance (CL) and volume of distribution (V). Logistic regression was used to examine the treatment outcome measures (serum peak and trough concentrations and ototoxicity). Simulations of new dosing regimens were undertaken for netilmicin and amikacin using MATLAB� The final gentamicin PK covariate model gave CL = 0.097 x (current weight/2)[1.3] x (postnatal age/7)[0.29] and V = 1.07 x (current weight/2)[0.8]+ (confirmed sepsis) x 0.13. A 10% increase in gentamicin V in neonates with sepsis was estimated. For amikacin, 17 (35%) of 49 episodes of confirmed sepsis met the treatment failure criteria from 12 (15%) individual patients. The final amikacin PK covariate model was CL = 0.23 x (current weight/2)[0.691] x (postmenstrual age/40)[3.23] and V = 0.957 x (current weight/2)[0.89]. PD analysis determined risk factors linked to hearing impairment in neonates treated with amikacin included: co-medication with vancomycin, high C-reactive protein concentration and low gestational age. Simulation of a new amikacin dosing regimen recommended: 15 mg/kg 36 hourly, 14 mg/kg 24 hourly, and 15 mg/kg 24 hourly, for neonates [less than or equal to] 28 weeks, 29 to 36 weeks, and [greater than or equal to] 37 postmenstrual age, respectively. For netilmicin, the final PK covariate model was CL = 0.192 x (current weight/2)[1.35] x (postmenstrual age/40)[1.03], V = 1.5 x (current weight/2)[0.3]. Simulation of a new optimal dosing regimen for netilmicin was: 5 mg/kg 36 hourly, 5 mg/kg 24 hourly, 6 mg/kg 24 hourly, and 7 mg/kg 24 hourly, for neonates [less than or equal to] 27, 28 to 30, 31 to 33, and [greater than or equal to] 34 weeks postmenstrual age, respectively. IV infusions representing gentamicin administration to neonates of 2.5 kg and 0.5 kg in the NICU setting (30 minutes gentamicin infusion then a 30 minute saline flush) showed the larger neonates received 80% of the drug within 60 minutes. This increased to 90-95% by 75 minutes. However, in extremely low birth weight neonates (0.5 kg), only 60% of the intended gentamicin dose was delivered by 60 minutes (70% by 75 minutes). In conclusion: IL-12(p70) and IL-10 were identified as promising diagnostic tests to confirm sepsis in neonates. Confirmed sepsis caused a 10% increase in V of gentamicin in neonates, suggesting larger initial dosages (mg/kg) are required for effective treatment of neonates with sepsis. Aminoglycoside clearance in neonates is predominantly affected by current weight, postmenstrual age or postnatal age. Adjusting netilmicin and amikacin doses based on current weight, and dosing interval based on both postmenstrual age and current weight improves drug efficacy. Identification of co-medication with vancomycin, low gestational age, and high C-reactive protein during treatment with amikacin increases risk of hearing impairment. The delivery of gentamicin administrated by IV infusion is substantially extended in extremely low birth weight neonates.