scholarly journals Neonatal lamb mortality: major risk factors and the potential ameliorative role of melatonin

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Tom Flinn ◽  
David O. Kleemann ◽  
Alyce M. Swinbourne ◽  
Jennifer M. Kelly ◽  
Alice C. Weaver ◽  
...  
Keyword(s):  
Risk Factors ◽  
Production Systems ◽  
Acute Hypoxia ◽  
Melatonin Treatment ◽  
Ovine Placenta ◽  
Sheep Production ◽  
Underlying Mechanisms ◽  
Fetal Oxygenation ◽  
In Utero Development

Abstract High incidences of pre-weaning mortality continue to limit global sheep production, constituting a major economic and welfare concern. Despite significant advances in genetics, nutrition, and management, the proportion of lamb deaths has remained stable at 15–20% over the past four decades. There is mounting evidence that melatonin can improve outcomes in compromised ovine pregnancies via enhanced uterine bloodflow and neonatal neuroprotection. This review provides an overview of the major risk factors and underlying mechanisms involved in perinatal lamb mortality and discusses the potential of melatonin treatment as a remedial strategy. Supplementing pregnant ewes with melatonin enhances uterine bloodflow and fetal oxygenation, and potentially birthweight and neonatal thermogenic capacity. Melatonin freely crosses the ovine placenta and blood-brain barrier and provides neuroprotection to the fetal lamb during periods of chronic and acute hypoxia throughout gestation, with improved behavioural outcomes in hypoxic neonates. The current literature provides strong evidence that maternal melatonin treatment improves outcomes for lambs which experience compromised in utero development or prolonged parturition, though to date this has not been investigated in livestock production systems. As such there is a clear basis for continued research into the effects of maternal melatonin supplementation during gestation on pre-weaning survival under extensive production conditions.

Leukotriene B4 promotes reactive oxidant generation and leukocyte adherence during acute hypoxia

2001 ◽  
Vol 91 (3) ◽  
pp. 1160-1167 ◽  
Author(s):  
Dawn R. S. Steiner ◽  
Norberto C. Gonzalez ◽  
John G. Wood
Keyword(s):  
Acute Hypoxia ◽  
Leukotriene B4 ◽  
Ros Generation ◽  
Leukocyte Adherence ◽  
Systemic Hypoxia ◽  
Microvascular Alterations ◽  
Reactive Oxidant ◽  
Underlying Mechanisms ◽  
Mesenteric Microcirculation

Acute systemic hypoxia produces rapid leukocyte adherence in the rat mesenteric microcirculation, although the underlying mechanisms are not fully known. Hypoxia is known to increase reactive oxygen species (ROS) generation, which could result in formation of the lipid inflammatory mediator leukotriene B4 (LTB4). The goal of this study was to examine the role of LTB4 in hypoxia-induced microvascular alterations. Using intravital microscopy, we determined the effect of the LTB4 antagonist, LTB4-dimethyl amide (LTB4-DMA), on ROS generation and leukocyte adherence in mesenteric venules during hypoxia. Exogenous LTB4 increased ROS generation to 144 ± 8% compared with control values and also promoted leukocyte adherence. These responses to LTB4 were blocked by pretreating the mesentery with LTB4-DMA. Leukopenia did not significantly attenuate the LTB4-induced increase in ROS generation (142 ± 12.1%). LTB4-DMA substantially, though not completely, reduced hypoxia-induced ROS generation from 66 ± 18% to 11 ± 4% above control values. Hypoxia-induced leukocyte adherence was significantly attenuated by LTB4-DMA. Our results support a role for LTB4in the mechanism of hypoxia-induced ROS generation and leukocyte adherence in the rat mesenteric microcirculation.

scholarly journals Investigating the role of stocking rate and prolificacy potential on profitability of grass based sheep production systems

2018 ◽  
Vol 210 ◽  
pp. 118-124 ◽  
Author(s):  
A. Bohan ◽  
L. Shalloo ◽  
P. Creighton ◽  
E. Earle ◽  
T.M. Boland ◽  
...  
Keyword(s):  
Production Systems ◽  
Stocking Rate ◽  
Sheep Production

scholarly journals Role of Silicon in Mediating Phosphorus Imbalance in Plants

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
An Yong Hu ◽  
Shu Nan Xu ◽  
Dong Ni Qin ◽  
Wen Li ◽  
Xue Qiang Zhao
Keyword(s):  
Production Systems ◽  
P Uptake ◽  
Regulatory Function ◽  
Schematic Model ◽  
P Nutrition ◽  
Greenhouse Production ◽  
P Deficiency ◽  
Soil P ◽  
Underlying Mechanisms

The soil bioavailability of phosphorus (P) is often low because of its poor solubility, strong sorption and slow diffusion in most soils; however, stress due to excess soil P can occur in greenhouse production systems subjected to high levels of P fertilizer. Silicon (Si) is a beneficial element that can alleviate multiple biotic and abiotic stresses. Although numerous studies have investigated the effects of Si on P nutrition, a comprehensive review has not been published. Accordingly, here we review: (1) the Si uptake, transport and accumulation in various plant species; (2) the roles of phosphate transporters in P acquisition, mobilization, re-utilization and homeostasis; (3) the beneficial role of Si in improving P nutrition under P deficiency; and (4) the regulatory function of Si in decreasing P uptake under excess P. The results of the reviewed studies suggest the important role of Si in mediating P imbalance in plants. We also present a schematic model to explain underlying mechanisms responsible for the beneficial impact of Si on plant adaption to P-imbalance stress. Finally, we highlight the importance of future investigations aimed at revealing the role of Si in regulating P imbalance in plants, both at deeper molecular and broader field levels.

scholarly journals Transmission of Onychomycosis and Dermatophytosis between Household Members: A Scoping Review

2022 ◽  
Vol 8 (1) ◽  
pp. 60
Author(s):  
Aria Jazdarehee ◽  
Leilynaz Malekafzali ◽  
Jason Lee ◽  
Richard Lewis ◽  
Ilya Mukovozov
Keyword(s):  
Risk Factors ◽  
Previous History ◽  
Household Transmission ◽  
Scoping Literature Review ◽  
History Of ◽  
Sources Of Infection ◽  
Household Cleaning ◽  
Household Members ◽  
Underlying Mechanisms

Onychomycosis is a common fungal infection of the nail, caused by dermatophytes, non-dermatophytes, and yeasts. Predisposing factors include older age, trauma, diabetes, immunosuppression, and previous history of nail psoriasis or tinea pedis. Though many biological risk factors have been well characterized, the role of the environment has been less clear. Studies have found evidence of transmission in 44% to 47% of households with at least one affected individual, but the underlying mechanisms and risk factors for transmission of onychomycosis between household members are incompletely understood. A scoping literature review was performed to characterize and summarize environmental risk factors involved in the transmission of onychomycosis within households. A total of 90 papers met the inclusion criteria, and extracted data was analyzed in an iterative manner. Shared household surfaces may harbor dermatophytes and provide sources for infection. Shared household equipment, including footwear, bedding, and nail tools, may transmit dermatophytes. The persistence of dermatophytes on household cleaning supplies, linen, and pets may serve as lasting sources of infection. Based on these findings, we provide recommendations that aim to interrupt household transmission of onychomycosis. Further investigation of the specific mechanisms behind household spread is needed to break the cycle of transmission, reducing the physical and social impacts of onychomycosis.

scholarly journals The Role of Oxidative Stress in Common Risk Factors and Mechanisms of Cardio-Cerebrovascular Ischemia and Depression

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Danfeng Lin ◽  
Lingling Wang ◽  
Shenqiang Yan ◽  
Qing Zhang ◽  
John H. Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Risk Factors ◽  
Health Sector ◽  
Social Stressors ◽  
The Public ◽  
High Prevalence ◽  
Common Risk Factors ◽  
Underlying Mechanisms ◽  
The Relationship

The public health sector faces a huge challenge as a result of the high prevalence and burden of disability caused by ischemic cardio-cerebrovascular disease (CVD) and depression. Although studies have explored the underlying mechanisms and potential therapies to address conditions, there is no treatment breakthrough, especially for depression which is highly influenced by social stressors. However, accumulating evidence reveals that CVD and depression are correlated and share common risk factors, particularly obesity, diabetes, and hypertension. They also share common mechanisms, including oxidative stress (OS), inflammation and immune response, cell death signaling pathway, and microbiome-gut-brain axis. This review summarizes the relationship between ischemic CVD and depression and describes the interactions among common risk factors and mechanisms for these two diseases. In addition, we propose that OS mediates the crosstalk between these diseases. We also reveal the potential of antioxidants to ameliorate OS-related injuries.

scholarly journals Heart failure in cancer patients

2022 ◽  
Vol 20 (6) ◽  
pp. 114-119
Author(s):  
A. F. Khalirakhmanov ◽  
A. Z. Sharafeev ◽  
G. D. Gatiyatullina ◽  
S. V. Zinchenko ◽  
R. F. Gaifullina ◽  
...  
Keyword(s):  
Risk Factors ◽  
Heart Failure ◽  
Cancer Patients ◽  
Epidemiological Studies ◽  
Diagnosis And Treatment ◽  
Cochrane Library ◽  
Chemotherapy Drugs ◽  
Underlying Mechanisms ◽  
The Cochrane Library

The purpose of the study was to conduct a systematic review of data on the role of heart failure (HF) in the development of cancer, as well as to discuss problems dealing with diagnosis and treatment of heart failure in cancer patients. Material and methods. A literature search was conducted using the Cochrane library, elibrary, medline, and embase databases over the past 7 years. The general mechanisms of heart failure and cancer, cardiotoxicity risk factors, and some aspects of the diagnosis and treatment of HF in cancer patients were analyzed. Results. The literature analysis indicates that cardiovascular disease and cancer have common risk factors. Several common pathophysiological mechanisms that associate HF with cancer have been identified. They include inflammation, oxidative stress, and neurohomonal activation. HF is known to be a common complication of aggressive cardiotoxic cancer therapy that can aggravate or trigger existing HF. Recent epidemiological studies have shown that the development of cancer is more common among patients with pre-existing HF. Although the reason for this relationship has not yet been identified, it is assumed that HF may be a pro-oncogenic condition. There are several strategies to prevent and treat toxicity of various chemotherapeutic drugs. They are all based on accurate patient selection, short- and longterm follow-up, and therapies that can prevent and delay cardiac dysfunction. Conclusion. The main goal of cardio-oncology is to prevent and treat of cardiotoxic effects of chemotherapy drugs. In this context, elucidation of the underlying mechanisms plays an important role in the development of strategies for the prevention of chemotherapy-associated cardiomyopathy. It is necessary to pay attention to the fact that there is more and more evidence that patients with HF have high risks of developing cancer, thereby requiring more attention. In general, understanding the direct and indirect mechanisms of the relationship between HF and cancer can help in the prevention and early diagnosis of these diseases.

Role of acquired and hereditary thrombotic risk factors in patients with ischemic colitis

2001 ◽  
Vol 120 (5) ◽  
pp. A282-A282
Author(s):  
I KOUTROUBAKIS ◽  
A SFIRIDAKI ◽  
A THEODOROPOULOU ◽  
A LIVADIOTAKI ◽  
P DIMOULIOS ◽  
...  
Keyword(s):  
Risk Factors ◽  
Ischemic Colitis ◽  
Thrombotic Risk

Psychological Resilience Provides No Independent Protection From Suicidal Risk

Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 130-139 ◽  
Author(s):  
Danica W. Y. Liu ◽  
A. Kate Fairweather-Schmidt ◽  
Richard Burns ◽  
Rachel M. Roberts ◽  
Kaarin J. Anstey
Keyword(s):  
Risk Factors ◽  
Well Being ◽  
Current Status ◽  
Psychological Resilience ◽  
Cross Sectional ◽  
Life Project ◽  
Resilience Factors ◽  
First Time

Abstract. Background: Little is known about the role of resilience in the likelihood of suicidal ideation (SI) over time. Aims: We examined the association between resilience and SI in a young-adult cohort over 4 years. Our objectives were to determine whether resilience was associated with SI at follow-up or, conversely, whether SI was associated with lowered resilience at follow-up. Method: Participants were selected from the Personality and Total Health (PATH) Through Life Project from Canberra and Queanbeyan, Australia, aged 28–32 years at the first time point and 32–36 at the second. Multinomial, linear, and binary regression analyses explored the association between resilience and SI over two time points. Models were adjusted for suicidality risk factors. Results: While unadjusted analyses identified associations between resilience and SI, these effects were fully explained by the inclusion of other suicidality risk factors. Conclusion: Despite strong cross-sectional associations, resilience and SI appear to be unrelated in a longitudinal context, once risk/resilience factors are controlled for. As independent indicators of psychological well-being, suicidality and resilience are essential if current status is to be captured. However, the addition of other factors (e.g., support, mastery) makes this association tenuous. Consequently, resilience per se may not be protective of SI.

Protective Factors and Suicidality in Members of Arab Kindred

Crisis ◽  
2012 ◽  
Vol 33 (2) ◽  
pp. 80-86 ◽  
Author(s):  
Sami Hamdan ◽  
Nadine Melhem ◽  
Israel Orbach ◽  
Ilana Farbstein ◽  
Mohammad El-Haib ◽  
...  
Keyword(s):  
Risk Factors ◽  
Protective Factors ◽  
Suicidal Behavior ◽  
Composite International Diagnostic Interview ◽  
Diagnostic Interview ◽  
Suicidal Risk ◽  
Arab Population ◽  
Psychiatric Interview ◽  
History Of

Background: Relatively little is known about the role of protective factors in an Arab population in the presence of suicidal risk factors. Aims: To examine the role of protective factors in a subsample of in large Arab Kindred participants in the presence of suicidal risk factors. Methods: We assessed protective and risk factors in a sample of 64 participants (16 suicidal and 48 nonsuicidal) between 15 and 55 years of age, using a comprehensive structured psychiatric interview, the Composite International Diagnostic Interview (CIDI), self-reported depression, anxiety, hopelessness, impulsivity, hostility, and suicidal behavior in first-degree and second-relatives. We also used the Religiosity Questionnaire and suicide attitude (SUIATT) and multidimensional perceived support scale. Results: Suicidal as opposed to nonsuicidal participants were more likely to have a lifetime history of major depressive disorder (MDD) (68.8% vs. 22.9% χ2 = 11.17, p = .001), an anxiety disorder (87.5% vs. 22.9, χ2 = 21.02, p < .001), or posttraumatic stress disorder (PTSD) (25% vs. 0.0%, Fisher’s, p = .003). Individuals who are otherwise at high risk for suicidality have a much lower risk when they experience higher perceived social support (3.31 ± 1.36 vs. 4.96 ± 1.40, t = 4.10, df = 62, p < .001), and they have the view that suicide is somehow unacceptable (1.83 ± .10 vs. 1.89 ± .07, t = 2.76, df = 60, p = .008). Conclusions: Taken together with other studies, these data suggest that the augmentation of protective factors could play a very important role in the prevention of incidental and recurrent suicidal behavior in Arab populations, where suicidal behavior in increasing rapidly.

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