26 resultados para anatomical and physiological traits
Resumo:
Over the last few years, we have seen an increasing interest and demand for pigs in biomedical research. Domestic pigs (Sus scrofa domesticus) are closely related to humans in terms of their anatomy, genetics, and physiology, and often are the model of choice for the assessment of novel vaccines and therapeutics in a preclinical stage. However, the pig as a model has much more to offer, and can serve as a model for many biomedical applications including aging research, medical imaging, and pharmaceutical studies to name a few. In this review, we will provide an overview of the innate immune system in pigs, describe its anatomical and physiological key features, and discuss the key players involved. In particular, we compare the porcine innate immune system to that of humans, and emphasize on the importance of the pig as model for human disease.
Resumo:
Mechanical injury of the CNS frequently results from accidents but also occurs in the course of neurosurgical interventions. A great variety of anatomical and physiological changes have been described to evolve after a brain trauma yet only little is known about processes that occur during a trauma. In the present study, I obtained whole-cell patch clamp recordings from pyramidal cells in hippocampal slice cultures while mechanically lesioning the CA3 area. Electrophysiological analysis revealed that traumatic injury massively increased excitatory and inhibitory synaptic activity in the entire CA3 region. Cutting the CA3 region induced highly rhythmic excitatory postsynaptic currents (EPSCs) that reached frequencies of around 70 Hz. Blocking voltage-dependent sodium channels with tetrodotoxin prevented the increase in synaptic activity and injury-induced neurotransmitter release in CA3 remote from the lesion site. With fast synaptic transmission blocked only neurons in the immediate vicinity of a lesion depolarized and fired action potentials upon mechanical damage. I hence suggest that mechanical injury damages the membrane and induces action potential firing in only a small population of neurons. This activity is then propagated throughout the undamaged CA3 network inducing highly rhythmic discharges. Thus mechanical brain injury initiates immediate functional changes that exceed the lesion site.
Resumo:
We conducted a qualitative, multicenter study using a focus group design to explore the lived experiences of persons with any kind of primary sleep disorder with regard to functioning and contextual factors using six open-ended questions related to the International Classification of Functioning, Disability and Health (ICF) components. We classified the results using the ICF as a frame of reference. We identified the meaningful concepts within the transcribed data and then linked them to ICF categories according to established linking rules. The six focus groups with 27 participants yielded a total of 6986 relevant concepts, which were linked to a total of 168 different second-level ICF categories. From the patient perspective, the ICF components: (1) Body Functions; (2) Activities & Participation; and (3) Environmental Factors were equally represented; while (4) Body Structures appeared poignantly less frequently. Out of the total number of concepts, 1843 concepts (26%) were assigned to the ICF component Personal Factors, which is not yet classified but could indicate important aspects of resource management and strategy development of those who have a sleep disorder. Therefore, treatment of patients with sleep disorders must not be limited to anatomical and (patho-)physiological changes, but should also consider a more comprehensive view that includes patient's demands, strategies and resources in daily life and the contextual circumstances surrounding the individual.
Resumo:
In order to improve the ability to link chemical exposure to toxicological and ecological effects, aquatic toxicology will have to move from observing what chemical concentrations induce adverse effects to more explanatory approaches, that are concepts which build on knowledge of biological processes and pathways leading from exposure to adverse effects, as well as on knowledge on stressor vulnerability as given by the genetic, physiological and ecological (e.g., life history) traits of biota. Developing aquatic toxicology in this direction faces a number of challenges, including (i) taking into account species differences in toxicant responses on the basis of the evolutionarily developed diversity of phenotypic vulnerability to environmental stressors, (ii) utilizing diversified biological response profiles to serve as biological read across for prioritizing chemicals, categorizing them according to modes of action, and for guiding targeted toxicity evaluation; (iii) prediction of ecological consequences of toxic exposure from knowledge of how biological processes and phenotypic traits lead to effect propagation across the levels of biological hierarchy; and (iv) the search for concepts to assess the cumulative impact of multiple stressors. An underlying theme in these challenges is that, in addition to the question of what the chemical does to the biological receptor, we should give increasing emphasis to the question how the biological receptor handles the chemicals, i.e., through which pathways the initial chemical-biological interaction extends to the adverse effects, how this extension is modulated by adaptive or compensatory processes as well as by phenotypic traits of the biological receptor.
Resumo:
To assess short- and long-term effects of bloodless castration methods with and without local anaesthesia, behavioural and cortisol responses of lambs were used as indicators of pain and distress. Seventy lambs, aged 2-7 days, were control-handled or castrated by Burdizzo or rubber ring methods with and without local anaesthesia. Either 5 mL of diluted lidocaine (4 mg/kg) or physiological sodium chloride solution was distributed in both spermatic cords and the scrotal neck. The serum cortisol response was monitored for 48 h, and behavioural and clinical traits were followed for three months. Local anaesthesia tended to reduce behavioural and cortisol responses after Burdizzo castration and provided a significant reduction after rubber ring castration. Prolonged pain after rubber ring castration with anaesthesia was not evident. If combined with local anaesthesia, both the rubber ring and the Burdizzo methods are acceptable methods for castration of lambs up to one week of age.
Resumo:
PURPOSE: To assess the outcomes in patients who required 1 or more vitreoretinal interventions for posterior segment complications arising from elective uneventful cataract surgery. SETTING: Tertiary referral center, single-center study. METHODS: A retrospective interventional case series included 56 consecutive patients who were referred for surgical correction of posterior segment complications within 6 months of cataract surgery. The study period was between 1996 and 2003, and the minimum follow-up was 5 months. RESULTS: Posterior segment complications were resolved with a single surgical intervention in 40 cases (71.4%). Within 5 months of primary surgical correction, persisting or newly arising posterior segment complications were noted in 16 cases (28.6%). After a mean of 2.1 +/- 1.4 (SD) additional surgeries, the number of eyes with posterior segment problems decreased to 7 (12.5%) (P = .035). Posterior segment complications requiring more than 1 vitreoretinal intervention included retinal detachment, endophthalmitis, and choroidal hemorrhages. After primary correction surgery, the mean best corrected visual acuity increased from 0.15 +/- 0.24 to 0.37 +/- 0.33 (P = .001) after a single intervention and to 0.39 +/- 0.32 (P>.05) after additional interventions. Although the intraocular pressure (IOP) decreased from 21.8 +/- 16.6 mm Hg to 14.9 +/- 3.4 mm Hg (P = .008), 4 (7.1%) consecutive vascular optic atrophies occurred. A reduction in corneal transparency was observed in 46.4% of patients before primary surgical correction and 12.5% after primary surgical correction (P<.001). CONCLUSIONS: In many cases, posterior segment complications arising from cataract surgery could be repaired with favorable functional and anatomical outcomes by a single vitreoretinal intervention. Additional surgery, if requested, provided stabilization of the anatomical and functional outcomes.
Resumo:
A critical phase in goal striving occurs when setbacks accumulate and goal disengagement becomes an issue. This critical phase is conceptualized as an action crisis and assumed to be characterized by an intrapsychic conflict in which the individual becomes torn between further goal pursuit and goal disengagement. Our theorizing converges with Klinger’s conceptualization of goal disengagement as a process, rather than a discrete event. Two longitudinal field studies tested and found support for the hypothesis that an action crisis not only compromises an individual’s psychological and physiological well-being, but also dampens the cognitive evaluation of the respective goal. In Study 3, marathon runners experiencing an action crisis in their goal of running marathons showed a stronger cortisol secretion and a lower performance in the race 2 weeks later. Results are interpreted in terms of action-phase–specific mindsets with a focus on self-regulatory processes in goal disengagement.
Resumo:
Head and neck cancer constitutes the 6th most common malignancy worldwide and affects the crucial anatomical structures and physiological functions of the upper aerodigestive tract. Classical therapeutic strategies such as surgery and radiotherapy carry substantial toxicity and functional impairment. Moreover, the loco-regional control rates as well as overall survival still need to be improved in subgroups of patients. The scatter-factor/hepatocyte growth factor receptor tyrosine kinase MET is an established effector in the promotion, maintenance and progression of malignant transformation in a wide range of human malignancies, and has been gaining considerable interest in head and neck cancer over the last 15 years. Aberrant MET activation due to overexpression, mutations, tumor-stroma paracrine loops, and cooperative/redundant signaling has been shown to play prominent roles in epithelial-to-mesenchymal transition, angiogenesis, and responses to anti-cancer therapeutic modalities. Accumulating preclinical and translational evidence highly supports the increasing interest of MET as a biomarker for lymph node and distant metastases, as well as a potential marker of stratification for responses to ionizing radiation. The relevance of MET as a therapeutic molecular target in head and neck cancer described in preclinical studies remains largely under-evaluated in clinical trials, and therefore inconclusive. Also in the context of anti-cancer targeted therapy, a large body of preclinical data suggests a central role for MET in treatment resistance towards multiple therapeutic modalities in malignancies of the head and neck region. These findings, as well as the potential use of combination therapies including MET inhibitors in these tumors, need to be further explored.
Resumo:
• Premise of the study: Because not all plant species will be able to move in response to global warming, adaptive evolution matters largely for plant persistence. As prerequisites for adaptive evolution, genetic variation in and selection on phenotypic traits are needed, but these aspects have not been studied in tropical species. We studied how plants respond to transplantation to different elevations on Mt. Kilimanjaro, Tanzania, and whether there is quantitative genetic (among-seed family) variation in and selection on life-history traits and their phenotypic plasticity to the different environments. • Methods: We reciprocally transplanted seed families of 15 common tropical, herbaceous species of the montane and savanna vegetation zone at Mt. Kilimanjaro to a watered experimental garden in the montane (1450 m) and in the savanna (880 m) zone at the mountain’s slope and measured performance, reproductive, and phenological traits. • Results: Plants generally performed worse in the savanna garden, indicating that the savanna climate was more stressful and thus that plants may suffer from future climate warming. We found significant quantitative genetic variation in all measured performance and reproductive traits in both gardens and for several measures of phenotypic plasticity in response to elevational transplantation. Moreover, we found positive selection on traits at low and intermediate trait values levelling to neutral or negative selection at high values. • Conclusions: We conclude that common plants at Mt. Kilimanjaro express quantitative genetic variation in fitness-relevant traits and in their plasticities, suggesting potential to adapt evolutionarily to future climate warming and increased temperature variability.
Resumo:
OBJECTIVES A dissociation between behavioural (in-control) and physiological parameters (indicating loss-of-control) is associated with cardiovascular risk in defensive coping (DefS) Africans. We evaluated relationships between DefS, sub-clinical atherosclerosis, low-grade inflammation and hypercoagulation in a bi-ethnic sex cohort. METHODS Black (Africans) and white Africans (Caucasians) (n = 375; aged 44.6 ± 9.7 years) were included. Ambulatory BP, vascular structure (left carotid cross-sectional wall area (L-CSWA) and plaque counts), and markers of coagulation and inflammation were quantified. Ethnicity/coping style interaction was revealed only in DefS participants. RESULTS A hypertensive state, less plaque, low-grade inflammation, and hypercoagulation were more prevalent in DefS Africans (27-84%) than DefS Caucasians (18-41%). Regression analyses demonstrated associations between L-CSWA and 24 hour systolic BP (R(2) = 0.38; β = 0.78; p < 0.05) in DefS African men but not in DefS African women or Caucasians. No associations between L-CSWA and coagulation markers were evident. CONCLUSION Novel findings revealed hypercoagulation, low-grade inflammation and hyperkinetic BP (physiological loss-of-control responses) in DefS African men. Coupled to a self-reported in-control DefS behavioural profile, this reflects dissociation between behaviour and physiology. It may explain changes in vascular structure, increasing cerebrovascular disease risk in a state of hyper-vigilant coping.
Resumo:
The relationships among animal form, function and performance are complex, and vary across environments. Therefore, it can be difficult to identify morphological and/or physiological traits responsible for enhancing performance in a given habitat. In fishes, differences in swimming performance across water flow gradients are related to morphological variation among and within species. However, physiological traits related to performance have been less well studied. We experimentally reared juvenile damselfish, Acanthochromis polyacanthus, under different water flow regimes to test 1) whether aspects of swimming physiology and morphology show plastic responses to water flow, 2) whether trait divergence correlates with swimming performance and 3) whether flow environment relates to performance differences observed in wild fish. We found that maximum metabolic rate, aerobic scope and blood haematocrit were higher in wave-reared fish compared to fish reared in low water flow. However, pectoral fin shape, which tends to correlate with sustained swimming performance, did not differ between rearing treatments or collection sites. Maximum metabolic rate was the best overall predictor of individual swimming performance; fin shape and fish total length were 3.3 and 3.7 times less likely than maximum metabolic rate to explain differences in critical swimming speed. Performance differences induced in fish reared in different flow environments were less pronounced than in wild fish but similar in direction. Our results suggest that exposure to water motion induces plastic physiological changes which enhance swimming performance in A. polyacanthus. Thus, functional relationships between fish morphology and performance across flow habitats should also consider differences in physiology.