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Limited research has explored longitudinal impact of stress on negative health outcomes, including overweight and obesity in Asian societies. Using data from a longitudinal school-based health promotion study conducted in Wuhan, China from 1999 to 2004, this study investigated the longitudinal effects of childhood stress exposure, including stressors related to school, family, peers, violence and health on overweight, and obesity risk during the transition to adolescence among 2179 Chinese adolescents. Results showed that health stressors were consistently related to higher BMI Z score for both boys and girls baseline, it also predicted higher likelihood of overweight status over time for girls. This finding highlights a particularly challenging time period for girls, suggesting a particular challenging time they face at the intersection of puberty and demanding school environment.
Assuntos
Comportamento do Adolescente/psicologia , Imagem Corporal/psicologia , Comportamento Infantil/psicologia , Promoção da Saúde , Obesidade Infantil/psicologia , Estresse Psicológico/psicologia , Adolescente , Criança , China/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Obesidade Infantil/epidemiologia , Maturidade Sexual , Estresse Psicológico/epidemiologia , UrbanizaçãoRESUMO
AIM: To develop test methods and evaluate survival of Bacillus thuringiensis kurstaki cry(-) HD-1 and B. thuringiensis Al Hakam spores after exposure to hot, humid air inside of a C-130 aircraft. METHODS AND RESULTS: Bacillus thuringiensis spores were either pre-inoculated on 1 × 2 or 2 × 2 cm substrates or aerosolized inside the cargo hold of a C-130 and allowed to dry. Dirty, complex surfaces (10 × 10 cm) swabbed after spore dispersal showed a deposition of 8-10 log10 m(-2) through the entire cargo hold. After hot, humid air decontamination at 75-80°C, 70-90% relative humidity for 7 days, 87 of 98 test swabs covering 0·98 m(2) , showed complete spore inactivation. There was a total of 1·67 log10 live CFU detected in 11 of the test swabs. Spore inactivation in the 98 test swabs was measured at 7·06 log10 m(-2) . CONCLUSIONS: Laboratory test methods for hot, humid air decontamination were scaled for a large-scale aircraft field test. The C-130 field test demonstrated that hot, humid air can be successfully used to decontaminate an aircraft. SIGNIFICANCE AND IMPACT OF THE STUDY: Transition of a new technology from research and development to acquisition at a Technology Readiness Level 7 is unprecedented.
Assuntos
Aeronaves , Bacillus anthracis/isolamento & purificação , Bacillus thuringiensis/isolamento & purificação , Descontaminação/métodos , Temperatura Alta , Umidade , Bacillus anthracis/fisiologia , Bacillus thuringiensis/fisiologia , Epidemias/prevenção & controle , Esporos Bacterianos/crescimento & desenvolvimentoRESUMO
AIMS: To develop test methods and evaluate survival of Bacillus anthracis ∆Sterne or Bacillus thuringiensis Al Hakam on materials contaminated with dirty spore preparations after exposure to hot, humid air using response surface modelling. METHODS AND RESULTS: Spores (>7 log10 ) were mixed with humic acid + spent sporulation medium (organic debris) or kaolin (dirt debris). Spore samples were then dried on five different test materials (wiring insulation, aircraft performance coating, anti-skid, polypropylene, and nylon). Inoculated materials were tested with 19 test combinations of temperature (55, 65, 75°C), relative humidity (70, 80, 90%) and time (1, 2, 3 days). The slowest spore inactivation kinetics was on nylon webbing and/or after addition of organic debris. CONCLUSIONS: Hot, humid air effectively decontaminates materials contaminated with dirty Bacillus spore preparations; debris and material interactions create complex decontamination kinetic patterns; and B. thuringiensis Al Hakam is a realistic surrogate for B. anthracis. SIGNIFICANCE AND IMPACT OF THE STUDY: Response surface models of hot, humid air decontamination were developed which may be used to select decontamination parameters for contamination scenarios including aircraft.
Assuntos
Bacillus anthracis/crescimento & desenvolvimento , Bacillus thuringiensis/crescimento & desenvolvimento , Descontaminação/métodos , Esporos Bacterianos/crescimento & desenvolvimento , Temperatura Alta , CinéticaRESUMO
Changes in the blood parameters of fingerlings of Clarias gariepinus were investigated after 24 and 96-h of exposures to endosulfan. 180 fingerlings of C. gariepinus [mean weight (10.5±1.3 g); total length (11.2±1.2 cm)] were exposed to five different concentrations (1.00, 2.20, 4.80, 11.00, 23.00 µg/L) of endosulfan and a control for 96 h after being acclimatized for 21 days. After 24 h of exposure, microcytic hypochromic anemia was observed and all erythrocyte profiles tested showed significant variation (p<0.05) among the treatments except thrombocyte and mean corpuscular hemoglobin concentration. Macrocytic hyperchromic anemia was noticed after 96 h of exposure and all the hematological parameters varied significantly (p<0.05) except packed cell volume and red blood cell count. The study shows that endosulfan alters the hematology of C. gariepinus fingerlings. Therefore, awareness on the hazards associated with the use of endosulfan should be intensified and sound sustainable alternatives to endosulfan should be developed.
Assuntos
Anemia/induzido quimicamente , Peixes-Gato/sangue , Endossulfano/toxicidade , Eritrócitos/efeitos dos fármacos , Inseticidas/toxicidade , Animais , Contagem de Eritrócitos , Índices de Eritrócitos , Hematócrito , Hidrocarbonetos CloradosRESUMO
AIM: The aim of the study was to develop test methods and evaluate survival of Francisella philomiragia cells and MS2 bacteriophage after exposure to PES-Solid (a solid source of peracetic acid) formulations with or without surfactants. METHODS AND RESULTS: Francisella philomiragia cells (≥7·6 log10 CFU) or MS2 bacteriophage (≥6·8 log10 PFU) were deposited on seven different test materials and treated with three different PES-Solid formulations, three different preneutralized samples and filter controls at room temperature for 15 min. There were 0-1·3 log10 CFU (<20 cells) of cell survival, or 0-1·7 log10 (<51 PFU) of bacteriophage survival in all 21 test combinations (organism, formulation and substrate) containing reactive PES-Solid. In addition, the microemulsion (Dahlgren Surfactant System) showed ≤2 log10 (100 cells) of viable F. philomiragia cells, indicating the microemulsion achieved <2 log10 CFU on its own. CONCLUSIONS: Three PES-Solid formulations and one microemulsion system (DSS) inactivated F. philomiragia cells and/or MS2 bacteriophage that were deposited on seven different materials. SIGNIFICANCE AND IMPACT OF THE STUDY: A test method was developed to show that reactive PES-Solid formulations and a microemulsion system (DSS) inactivated >6 log10 CFU/PFU F. philomiragia cells and/or MS2 bacteriophage on different materials.
Assuntos
Descontaminação/métodos , Desinfetantes/farmacologia , Desinfecção/métodos , Francisella/efeitos dos fármacos , Levivirus/efeitos dos fármacos , Ácido Peracético/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , TensoativosRESUMO
Previous studies from our laboratory have shown positive benefits of linoleic acid (LA) feeding for attenuation of rat heart failure (HF). However, another research group concluded LA feeding was detrimental to cardiac function, using the American Institute of Nutrition 76A (AIN) diet as a background diet for the experimental animals only. To reconcile these conflicting results and determine whether (i) AIN has effects on cardiovascular function, and (ii) AIN reverses the positive effects of LA feeding, studies were performed using spontaneously hypertensive heart failure (SHHF) rats in both a survival study with lifetime feeding of AIN (control: Purina 5001) and a 2 × 2 factorial design for 6 weeks in young male SHHF rats with background diet and LA as variables. During a lifetime of AIN feeding, mortality from heart failure is significantly accelerated, cardiolipin altered and triglycerides increased. In young rats, 6 weeks on the AIN diet promoted increased systolic and diastolic blood pressure, increased fed and fasting blood glucose, increased serum inflammatory eicosanoids, decreased docosahexanoic acid, increased posterior wall thickness in diastole and an altered cardiolipin subspecies profile. The addition of LA to the AIN diet was able to rescue blood pressure. However, the combination increased retroperitoneal fat mass, body weight and fed blood glucose beyond the levels with the AIN diet alone. Because the AIN diet has wide ranging effects on cardiovascular parameters, our results suggest that it should not be used in animal studies involving the cardiovascular system unless induction of cardiac dysfunction is the desired outcome.
Assuntos
Ração Animal/análise , Dieta , Insuficiência Cardíaca/induzido quimicamente , Animais , Pressão Sanguínea , Peso Corporal , Feminino , Masculino , Estado Nutricional , Ratos , Ratos Endogâmicos SHRRESUMO
AIMS: To develop test methods and evaluate survival of Bacillus anthracis Ames, B. anthracis ∆Sterne and B. thuringiensis Al Hakam spores after exposure to PES-Solid (a solid source of peracetic acid), including PES-Solid formulations with bacteriostatic surfactants. METHODS AND RESULTS: Spores (≥ 7 logs) were dried on seven different test materials and treated with three different PES-Solid formulations (or preneutralized controls) at room temperature for 15 min. There was either no spore survival or less than 1 log (<10 spores) of spore survival in 56 of 63 test combinations (strain, formulation and substrate). Less than 2.7 logs (<180 spores) survived in the remaining seven test combinations. The highest spore survival rates were seen on water-dispersible chemical agent resistant coating (CARC-W) and Naval ship topcoat (NTC). Electron microscopy and Coulter analysis showed that all spore structures were intact after spore inactivation with PES-Solid. CONCLUSIONS: Three PES-Solid formulations inactivated Bacillus spores that were dried on seven different materials. SIGNIFICANCE AND IMPACT OF THE STUDY: A test method was developed to show that PES-Solid formulations effectively inactivate Bacillus spores on different materials.
Assuntos
Bacillus anthracis/efeitos dos fármacos , Bacillus thuringiensis/efeitos dos fármacos , Descontaminação/métodos , Desinfetantes/farmacologia , Ácido Peracético/farmacologia , Bacillus anthracis/ultraestrutura , Bacillus thuringiensis/ultraestrutura , Desinfetantes/química , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/ultraestruturaRESUMO
Mammalian DNA is methylated at many CpG dinucleotides. The biological consequences of methylation are mediated by a family of methyl-CpG binding proteins. The best characterized family member is MeCP2, a transcriptional repressor that recruits histone deacetylases. Our report concerns MBD2, which can bind methylated DNA in vivo and in vitro and has been reported to actively demethylate DNA (ref. 8). As DNA methylation causes gene silencing, the MBD2 demethylase is a candidate transcriptional activator. Using specific antibodies, however, we find here that MBD2 in HeLa cells is associated with histone deacetylase (HDAC) in the MeCP1 repressor complex. An affinity-purified HDAC1 corepressor complex also contains MBD2, suggesting that MeCP1 corresponds to a fraction of this complex. Exogenous MBD2 represses transcription in a transient assay, and repression can be relieved by the deacetylase inhibitor trichostatin A (TSA; ref. 12). In our hands, MBD2 does not demethylate DNA. Our data suggest that HeLa cells, which lack the known methylation-dependent repressor MeCP2, use an alternative pathway involving MBD2 to silence methylated genes.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Histona Desacetilases/fisiologia , Proteínas Repressoras/fisiologia , Transcrição Gênica , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/metabolismo , Metilação de DNA , Inibidores Enzimáticos/farmacologia , Células HeLa , Humanos , Ácidos Hidroxâmicos/farmacologia , Camundongos , Modelos Genéticos , Dados de Sequência Molecular , Ratos , Proteínas Recombinantes/metabolismo , Proteínas Repressoras/metabolismo , Complexo Correpressor Histona Desacetilase e Sin3 , Ativação Transcricional , TransfecçãoRESUMO
Nitrogen (N) loss from livestock agriculture via ammonia and nitrous oxide can reduce feed efficiency, production and negatively affect the environment. One option to reduce N loss is to add dietary supplements such as Yucca schidigera extract which has ammonia-binding properties and contains antimicrobial steroidal saponins, or Saccharomyces cerevisiae yeast, which can stabilise rumen pH and promote fibre degradation, increasing microbial growth and demand for degradable N. To determine the effect of Yucca schidigera extract when fed alone or in combination with a live yeast on the performance, rumen metabolism, microbiome and N balance, six rumen cannulated dairy cows were fed a mixed ration (C), mixed ration with Y. schidigera extract (De-Odorase®, Alltech®; 5 g/cow/day; D), or mixed ration with Y. schidigera extract (5 g/day) and Saccharomyces cerevisiae (Yea-Sacc®, Alltech®, 1 g/cow per day; DY), in a 3 × 3 Latin rectangle design study with three periods of 49-day duration. Digesta samples were collected via the ruminal cannula during the final week of each period and separated into liquid (LPD) and solid (SPD) phases for microbiome analysis using 16S rRNA amplicon sequencing. DM intake was 0.8 kg/d lower (P < 0.05) in cows fed DY than C or D, with milk protein concentration 1.7 g/kg higher in C than D or DY. There was a beta diversity (Bray Curtis) clustering of the LPD in cows fed D or DY compared to C (P < 0.05), driven by an increase in Prevotella ruminicola-related operational taxonomic units (OTUs), and a decrease in P. brevis and P. bryantii OTUs. A methanogen OTU, Methanobrevibacter olleyae, was decreased in cows fed D or DY and an unclassified species of Gammaproteobacteria was increased in DY (LDA > 2.0, P < 0.05) compared to C. Rumen pH, ammonia and total VFA concentration were not affected by treatment (P > 0.05) but the concentration of propionate and iso-butyrate were lower at 1700 and 2000 h in cows fed DY compared to C (P < 0.05). Measurements of N balance were unaffected by supplementation with D or DY, and there was no effect of treatment on slurry pH. In conclusion, supplementing with an extract of Yucca schidigera either alone or in combination with a live yeast had only a small effect on performance, with Yucca schidigera altering species associated with carbohydrate and protein metabolism, and reduced Methanobrevibacter olleyae which is involved in methanogenesis.
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AIMS: To develop test methods and evaluate the survival of Bacillus anthracis ∆Sterne and Bacillus thuringiensis Al Hakam spores after exposure to hot, humid air. METHODS AND RESULTS: Spores (>7 logs) of both strains were dried on six different test materials. Response surface methodology was employed to identify the limits of spore survival at optimal test combinations of temperature (60, 68, 77°C), relative humidity (60, 75, 90%) and time (1, 4, 7 days). No spores survived the harshest test run (77°C, 90% r.h., 7 days), while > 6·5 logs of spores survived the mildest test run (60°C, 60% r.h., 1 day). Spores of both strains inoculated on nylon webbing and polypropylene had greater survival rates at 68°C, 75% r.h., 4 days than spores on other materials. Electron microscopy showed no obvious physical damage to spores using hot, humid air, which contrasted with pH-adjusted bleach decontamination. CONCLUSIONS: Test methods were developed to show that hot, humid air effectively inactivates B. anthracis ∆Sterne and B. thuringiensis Al Hakam spores with similar kinetics. SIGNIFICANCE AND IMPACT OF THE STUDY: Hot, humid air is a potential alternative to conventional chemical decontamination.
Assuntos
Bacillus anthracis/isolamento & purificação , Bacillus thuringiensis/isolamento & purificação , Descontaminação/métodos , Temperatura Alta , Umidade , Ar , Microscopia Eletrônica de Transmissão , Esporos Bacterianos/isolamento & purificação , Esporos Bacterianos/ultraestrutura , Estatística como AssuntoRESUMO
A machine learning approach has been implemented to measure the electron temperature directly from the emission spectra of a tokamak plasma. This approach utilized a neural network (NN) trained on a dataset of 1865 time slices from operation of the DIII-D tokamak using extreme ultraviolet/vacuum ultraviolet emission spectroscopy matched with high-accuracy divertor Thomson scattering measurements of the electron temperature, Te. This NN is shown to be particularly good at predicting Te at low temperatures (Te < 10 eV) where the NN demonstrated a mean average error of less than 1 eV. Trained to detect plasma detachment in the tokamak divertor, a NN classifier was able to correctly identify detached states (Te < 5 eV) with a 99% accuracy (an F1 score of 0.96) at an acquisition rate 10× faster than the Thomson scattering measurement. The performance of the model is understood by examining a set of 4800 theoretical spectra generated using collisional radiative modeling that was also used to predict the performance of a low-cost spectrometer viewing nitrogen emission in the visible wavelengths. These results provide a proof-of-principle that low-cost spectrometers leveraged with machine learning can be used to boost the performance of more expensive diagnostics on fusion devices and be used independently as a fast and accurate Te measurement and detachment classifier.
RESUMO
Motion thresholds were determined for the fovea and peripheral retina with and without correction for peripheral refractive error. With correction, motion thresholds decreased and inidividual differences disappeared. These results imply that under normal observation conditions, peripheral sensitivity is limited mainly by dioptric rather than retinal variables.
Assuntos
Percepção de Movimento , Erros de Refração/fisiopatologia , Campos Visuais , Adulto , Humanos , Macula Lutea/fisiologia , Masculino , Retina/fisiologiaRESUMO
Scalable parallel computer architectures provide the computational performance needed for advanced biomedical computing problems. The National Institutes of Health have developed a number of parallel algorithms and techniques useful in determining biological structure and function. These applications include processing electron micrographs to determine the three-dimensional structure of viruses, calculating the solvent-accessible surface area of proteins to help predict the three-dimensional conformation of these molecules from their primary structures, and searching for homologous DNA or amino acid sequences in large biological databases. Timing results demonstrate substantial performance improvements with parallel implementations compared with conventional sequential systems.
Assuntos
Simulação por Computador , Computadores , Pesquisa , Algoritmos , Capsídeo/ultraestrutura , Bases de Dados Factuais , Processamento de Imagem Assistida por Computador , National Institutes of Health (U.S.) , Conformação Proteica , Dobramento de Proteína , Homologia de Sequência do Ácido Nucleico , Simplexvirus/ultraestrutura , Tomografia Computadorizada de Emissão , Estados UnidosRESUMO
AIM: To determine whether there is evidence of a reduction in radiology research activity in the UK following the implementation of the European research ethics legislation, which came in to force in 2001 and has been widely criticised as an impediment to research. MATERIALS AND METHODS: A bibliometric analysis was performed by searching PubMed for all first-author publications from UK departments of "radiology" or "medical imaging" between 1995 and 2007. Results were sub-categorized into those papers published in the highest cited general radiology journals and by publication type: original research, reviews, and case reports. RESULTS: From 1995 to 2007 the total number of publications rose by 6.5% from 137 to 146 with the increase occurring in non-general radiology journals. Original articles fell from 18 in 1995 to 12 in 2003, but then rose to 24 by 2007 (33% rise). This dip was paralleled by a fall and then recovery in case report publications. The most dramatic change has been in the number of review articles, which has increased more than eightfold from seven in 1995 to 65 in 2007 to become the most common form of publication. CONCLUSION: The overall number of original scientific articles, published by first-author UK radiologists, has increased slightly over the last 12 years despite a temporary fall associated with the introduction of new research ethics legislation.
Assuntos
Bibliometria , Radiologia , Pesquisa , Europa (Continente) , Humanos , Radiologia/ética , Radiologia/legislação & jurisprudência , Radiologia/estatística & dados numéricos , Pesquisa/legislação & jurisprudência , Pesquisa/estatística & dados numéricos , Estudos Retrospectivos , Reino UnidoRESUMO
Primary cilia have a broad tissue distribution and are present on most cell types in the human body. Until recently, they were considered to be redundant organelles, but progress over the past 5 years has led to an understanding of their role in normal mammalian development. The class of inherited disorders that involve aberrant ciliary function are known as ciliopathies, and although their range of severity can vary, they share some common and unexpected clinical phenotypes. The aim of this review is to assess recent insights into the structure, function and formation of primary cilia, and relate this to the pathology, molecular genetics and cell biology of the ciliopathies.
Assuntos
Cílios/fisiologia , Doenças Genéticas Inatas/genética , Animais , Síndrome de Bardet-Biedl/genética , Cílios/metabolismo , Doenças Genéticas Inatas/patologia , Humanos , Modelos Biológicos , Fenótipo , Transdução de Sinais , SíndromeRESUMO
Perimetry is a commonly used clinical test for visual function, limited by high variability. The sources of this variability need to be better understood. In this paper, we investigate whether noise intrinsic to neural firing could explain the variability in normal subjects. We present the most physiologically accurate model to date for stimulus detection in perimetry combining knowledge of the physiology of components of the visual system with signal detection theory, and show that it requires that detection be mediated by multiple cortical cells in order to give predictions consistent with psychometric functions measured in human observers.
Assuntos
Sensibilidades de Contraste/fisiologia , Modelos Neurológicos , Modelos Psicológicos , Córtex Visual/fisiologia , Campos Visuais/fisiologia , Adulto , Humanos , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Psicometria , Psicofísica , Células Ganglionares da Retina/fisiologia , Limiar Sensorial/fisiologia , Detecção de Sinal Psicológico , Testes de Campo VisualRESUMO
Conflicts over reproductive division of labour are common in social insects. These conflicts are often resolved via antagonistic actions that are mediated by chemical cues. Dominant egg layers and their eggs can be recognized by a specific yet similar cuticular hydrocarbon profile. In the facultatively queenless ant Gnamptogenys striatula, a worker's cuticular hydrocarbon profile signals its fertility and this determines its position in the reproductive division of labour. How eggs acquire the same hydrocarbon profile is as yet unclear. Here, we search for glandular sources of egg hydrocarbons and identify the putative mechanism of egg marking. We found that eggs carry the same hydrocarbons as the cuticle of fertile workers, and that these hydrocarbons also occur in the ovaries and the haemolymph. None of the studied glands (Dufour, venom, labial and mandibular gland) contained these hydrocarbons. Our results indicate that hydrocarbons are deposited on eggs while still in the ovaries. The low hydrocarbon concentration in the ovaries, however, suggests they are produced elsewhere and transported through the haemolymph. We also found that fertile workers regularly deposit new hydrocarbons on eggs by rubbing laid eggs with a hairy structure on the abdominal tip from which a non-polar substance is secreted.
Assuntos
Formigas/fisiologia , Comunicação Animal , Animais , Formigas/química , Formigas/ultraestrutura , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos/química , Óvulo/química , Reprodução , Comportamento Sexual Animal , Predomínio SocialRESUMO
Through a variety of mechanisms, pregnancy causes insulin resistance, which suppresses the intracellular transport of glucose and increases blood glucose concentrations. In the extreme, gestational diabetes (GDM) mellitus may develop. In addition to insulin resistance, pregnant bitches have decreased ability to produce glucose via gluconeogenesis, glycogenolysis and lipolysis, because the normal multi-factorial responses to hypoglycemia are blunted late in pregnancy. Simply fasting late-pregnant bitches is sufficient to cause blood glucose and insulin concentrations to decrease and ketones to increase. The purpose of this paper is to review the clinical implications of pregnancy-associated changes in glucose homeostasis in bitches.
Assuntos
Glicemia/metabolismo , Doenças do Cão/metabolismo , Hipoglicemia/veterinária , Resistência à Insulina , Cetose/veterinária , Complicações na Gravidez/veterinária , Animais , Doenças do Cão/prevenção & controle , Cães , Feminino , Homeostase , Gravidez , Complicações na Gravidez/metabolismo , Complicações na Gravidez/prevenção & controleRESUMO
Pregnancy management to optimize maternal and neonatal health begins with breeding management and the selection of normal, healthy brood stock in ideal body condition. After breeding, a commercial diet appropriate for reproduction and lactation should be fed. Typically these contain 29-32% protein of animal source, at least 18% fat, 20-30% carbohydrate, and essential vitamins, minerals and fatty acids. Pregnancy is confirmed approximately 25 d after breeding. A "maternity ward" and whelping box should be provided. Steady increases in caloric intake and body weight are expected as pregnancy progresses. Weight loss should not occur. Throughout pregnancy, changes in the bitch's attitude, activity, appetite, body weight, and physical findings should be monitored by the owner. If appetite and body weight do not continue to increase, or if any signs of illness develop, maternal health should be assessed with a complete physical examination and a CBC, biochemical profile, and free-catch urinalysis. Fetal health should be assessed with ultrasonography. Maternal or fetal abnormalities will put the pregnancy at risk. Impending parturition and the progress of labor and delivery can be monitored by assessing rectal temperature, serum concentrations of progesterone, and/or uterine and fetal monitors. This article reviews the physiology of canine pregnancy and parturition, and typical schemes used to manage normal canine pregnancy to optimize maternal and puppy health.
Assuntos
Criação de Animais Domésticos/métodos , Cães/fisiologia , Prenhez/fisiologia , Animais , Cruzamento , Feminino , Parto , GravidezRESUMO
High-risk pregnancies are those in which the prevalence of maternal, fetal and/or perinatal morbidity or mortality is likely to be higher than that of the general obstetrical population. Some maternal characteristics associated with risk to maternal, fetal and/or perinatal health are readily identifiable prior to conception, such as advanced maternal age, brachycephalic breed, or a previous history of pregnancy loss. Others, such as gestational diabetes or a singleton litter, are recognized after conception. Early recognition of the problem (i.e. the risk), anticipation of the potential sequelae, and development of an aggressive management scheme are essential for a successful outcome of a high-risk pregnancy. A previous history of pregnancy loss is a high-risk factor for recurrence during subsequent pregnancies. Infection is a common cause. In some instances, recurrent pregnancy loss is associated with low serum concentrations of progesterone. Although the mechanism(s) by which this occurs is not fully understood, the situation has been called hypoluteoidism. Whatever the cause of the risks to pregnancy, the goals of managing high-risk pregnancies are to optimize maternal, fetal and perinatal health, so as to maintain maternal health throughout pregnancy and lactation and maximize the number of healthy pups surviving to weaning age.