Impact of climate change on wetland ecosystems: A critical review of experimental wetlands

Climate change is identified as a major threat to wetlands. Altered hydrology and rising temperature can change the biogeochemistry and function of a wetland to the degree that some important services might be turned into disservices. This means that they will, for example, no longer provide a water purification service and adversely they may start to decompose and release nutrients to the surface water. Moreover, a higher rate of decomposition than primary production (photosynthesis) may lead to a shift of their function from being a sink of carbon to a source. This review paper assesses the potential response of natural wetlands (peatlands) and constructed wetlands to climate change in terms of gas emission and nutrients release. In addition, the impact of key climatic factors such as temperature and water availability on wetlands has been reviewed. The authors identified the methodological gaps and weaknesses in the literature and then introduced a new framework for conducting a comprehensive mesocosm experiment to address the existing gaps in literature to support future climate change research on wetland ecosystems. In the future, higher temperatures resulting in drought might shift the role of both constructed wetland and peatland from a sink to a source of carbon. However, higher temperatures accompanied by more precipitation can promote photosynthesis to a degree that might exceed the respiration and maintain the carbon sink role of the wetland. There might be a critical water level at which the wetland can preserve most of its services. In order to find that level, a study of the key factors of climate change and their interactions using an appropriate experimental method is necessary. Some contradictory results of past experiments can be associated with different methodologies, designs, time periods, climates, and natural variability. Hence a long-term simulation of climate change for wetlands according to the proposed framework is recommended. This framework provides relatively more accurate and realistic simulations, valid comparative results, comprehensive understanding and supports coordination between researchers. This can help to find a sustainable management strategy for wetlands to be resilient to climate change.     

Prevalence and pathogenesis of hypokalemia in patients on chronic peritoneal dialysis: One center's experience and review of the literature

International Urology and Nephrology -     

Induction of apoptosis and cell cycle arrest by pericarp polyphenol-rich extract of Baneh in human colon carcinoma HT29 cells

Plants as important source of natural active components with anticancer effects commonly are different in structure and biological properties. The pericarp of Pistacia atlantica sub kurdica with local name of Baneh, a rich source of active phytochemicals, contains noticeable amounts of polyphenolic compounds, flavonoids and anthocyanins. Therefore, the antiproliferative, apoptosis induction and cell cycle alterations of Baneh were evaluated in human colon carcinoma HT29 cells. The Baneh extract (0.7 mg/ml) resulted in 50% growth inhibition similar to 500 nM of Doxorubicin (Dox) in HT29 cells after 72 h. The down-regulation of cyclin A protein by Baneh extract induced S phase delay in cell cycle progression of HT29 cells. Unlike the Baneh extract, Dox showed G2/M accumulation of HT29 cells which was associated with an increase in cyclin A and cyclin B1 protein expression. Furthermore, the induction of apoptosis following Baneh extract and Dox treatment in HT29 cells was confirmed by DNA fragmentation and translocation of phosphatidylserine. The morphological characteristics of apoptosis were also observed in HT29 cells exposed to the Baneh extract and Dox. These results suggest that due to the existence of bioactive components, methanolic extract of the Baneh has significant cytotoxic effects against human colon carcinoma HT29 cells.     

Diabetic CVD--focus on vitamin D

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity among diabetics. Vitamin D deficiency is very common all over the world. Over last few years, vitamin D has been considered as an important regulating factor for cardiovascular health. Metabolic syndrome and obesity are highly prevalent in vitamin D deficient people. In fact all components of metabolic syndrome are affected by vitamin D. Vitamin D regulates insulin secretion and its action. It has also some controlling effect on Renin-Angiotensin system, which influences cardiomyocytes positively. Vitamin D plays a role in vascular system too. This vitamin reduces vascular calcification and inflammatory processes. Given the important role of Vitamin D in cardiovascular health, this review focuses on the impacts of vitamin D on the various CVD risk factors.     

Complication of lengthening and the role of post-operative care,physical and psychological rehabilitation among fibula hemimelia

There is a clear clinical need for efficient physiotherapy and rehabilitation programs during and after bone lengthening and reconstruction for gaining the optimal effect and also prevention or treatment of lengthening side effects. Pin tract infection is the most prevalent side effect during lengthening which could be prevented and treated initially via proper wound care. Muscle contractures are typically a consequence of the generated tension on the distracted muscle. It can be managed by physiotherapy initially and surgically in later severe stages. Furthermore, it is essential to avoid muscle contracture development, which is the demonstration of the imbalanced muscle appeals on the joint to inhibit the following subluxation. The knee is the furthermost affected joint by the aforementioned problem due to the inherent lack of ligamentous and bony stability. Joint stiffness is the other possible unfavorable effect of lengthening. It happens because of extensive muscle contractures or may possibly be attributed to rigidity of the joint following the amplified pressure on the joint surface during the process of lengthening. Physiotherapy and occupational therapy including endurance and strength exercise as well as stretching play an important role during the rehabilitation periods for the prevention and also the treatment of muscle contracture and the following deformity and also joint stiffness. Likewise, the effect of mental and physical rehabilitation programs should not be overlooked.     

Inflammation biomarkers and delirium in critically ill patients: new insights?

The pathophysiological mechanism of the serious and frequently occurring disorder delirium is poorly understood. Inflammation and sepsis are known risk factors for ICU delirium and therefore these patients are highly susceptible to delirium. Several studies have been performed to determine which cytokines are most associated with delirium but the results are inconclusive. Also, new biomarkers associated with brain dysfunction and cognitive impairment are still recognized and need to be studied to determine their relation with delirium. In this commentary we address some limitations concerning an interesting new study that warrants directions for future studies.We read with interest the study by Ritter and colleagues in which the relationship between inflammatory biomarkers and the development of delirium was investigated [1]. While delirium in critically ill patients is recognized as a major problem associated with deleterious outcome, the pathophysiology is still poorly understood. Apart from a role in further unraveling pathophysiological pathways in delirium, biomarkers could possibly also be used as diagnostic or prognostic disease markers. This task might prove to be difficult, as delirium is a multifactorial disorder and thus several pathways are probably involved in its development [2]. Studying the underlying mechanism of delirium in a relatively homogeneous study population, as Ritter and colleagues did in 78 inflamed patients [1], could minimize the interaction between different pathways. Patients with systemic inflammation or sepsis are highly vulnerable to developing brain dysfunction and delirium, also defined as sepsis-associated delirium or sepsis-associated encephalopathy [3], and could therefore serve this purpose.Ritter and colleagues studied TNFα, soluble TNF receptor (STNFR)-1, STNFR2, IL-1β, IL-6, IL-10 and adiponectin in systemic inflamed patients in relation to delirium [1]. In their prospective cohort study they found significant associations between STNFR1, STNFR2, IL-1β and adiponectin concentrations and the development of delirium.We previously found that delirium was associated with IL-8 (odds ratio, 9.0; 95% confidence interval, 1.8 to 44.0) and IL-10 (odds ratio, 2.6; 95% confidence interval, 1.1 to 5.9) but not with TNFα in inflamed ICU patients [4]. In contrast, Ritter and colleagues found no association between IL-10 and delirium. This discrepancy might be explained by differences in study design: Ritter and colleagues collected blood samples within 12 hours of ICU admission, while in our study blood was drawn within 24 hours after the onset of delirium regardless of ICU length of stay. In view of the changes over time in the concentration of cytokines and the development of delirium, serial determinations of circulating inflammatory markers and the relationship with the development of delirium would be of great interest, but this has not been carried out in ICU patients up to now.Surprisingly, Ritter and colleagues found no differences in several patient characteristics such as age, severity of illness scores, and duration of mechanical ventilation, but also not in the presence of sepsis, between delirious and nondelirious ICU patients, while these characteristics are clearly recognized as risk factors for delirium [5-7]. A possible explanation for why they did not find these differences could be the frequency of delirium assessment. Due to its fluctuating course, delirium can be missed when patients are assessed with the Confusion Assessment Method for the Intensive Care Unit only twice a day – especially when it is recognized that on average 20% of delirium is missed when using the Confusion Assessment Method for the Intensive Care Unit [8]. This fact may also explain the observed relatively low delirium incidence (39.7%) in these highly susceptible patients suffering from systemic inflammation.Another interesting and very relevant point is that Ritter and colleagues also studied, besides the common proinflammatory and anti-inflammatory cytokines, the hormone adiponectin. Adiponectin was recently determined to interact with the brain [9] and to play a role in neuroprotection and energy expenditure. Levels of adiponectin are elevated in critically ill patients [10] and even higher in delirious ICU patients, as Ritter and colleagues determined [1]. These authors are the first to determine an association between adiponectin levels (adjusted for weight) and delirium.Although not a primary study aim, Ritter and colleagues also determined the accuracy of the prediction of delirium using these biomarkers. Even though IL-β, STNFR1, STNFR2 and adiponectin individually predict delirium moderately well (area under the receiver operating characteristics curve: 0.70 to 0.84), the authors did not mention the overall area under the receiver operating characteristics curve of the model using multivariate regression analysis. Unfortunately the sample size in their study did not allow inclusion of other relevant risk factors. In daily clinical practice, therefore, using a delirium prediction model specifically developed for prediction based on clinical risk factors appears better [11]. Despite these shortcomings, their study was well designed and their findings are very relevant to further progress this field.Currently, the role of biomarkers as Ritter and colleagues determined is, although relevant, still limited for daily clinical practice. Serial measurements of inflammatory markers in ICU patients and further research into the role of adiponectin in the development of delirium warrant further investigation in future studies.