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•P removal from simulated wastewater using lab-scale HSSF-CWs was examined.•Paspalum atratum was utilized as the emergent wetland plant for very first time.•WHC-based HSSF-CW planted ...with Paspalum atratum removed up to 89.9% of inflow P.•WHC sorption was the dominant P removal pathway in HSSF-CWs.•Utilizing WHC as a reactive filter media apparently extended lifespans of HSSF-CWs.
This work examined the phosphorus (P) removal from the synthetic pretreated swine wastewater using lab-scale horizontal sub-surface flow constructed wetlands (HSSF-CWs). White hard clam (Meretrix lyrata) shells (WHC) and Paspalum atratum were utilized as substrate and plant, respectively. The focus was placed on treatment performance, removal mechanisms and lifespan of the HSSF-CWs. Results indicated that WHC-based HSSF-CW with P. atratum exhibited a high P removal (89.9%). The mean P efluent concentration and P removal rate were 1.34 ± 0.95 mg/L and 0.32 ± 0.03 g/m2/d, respectively. The mass balance study showed that media sorption was the dominant P removal pathway (77.5%), followed by microbial assimilation (14.5%), plant uptake (5.4%), and other processes (2.6%). It was estimated the WHC-based bed could work effectively for approximately 2.84 years. This WHC-based HSSF-CWs technology will therefore pave the way for recycling Ca-rich waste materials as media in HSSF-CWs to enhance P-rich wastewater purification.
H2O2 is able to oxidize and reduce Cu allowing Cu to catalytically degrade H2O2. At circumneutral pH, the oxidant Cu(III) is formed during the Cu(I)–H2O2 reaction. A kinetic model has been developed ...which reliably describes these interactions. Display omitted
► Reaction of nanomolar Cu(II) with H2O2 results in Cu-catalyzed production of the strong oxidant, Cu(III). ► Hydroxyl radical production as a result of the reaction of Cu(I) and H2O2 is insignificant under the conditions used. ► A kinetic model has been developed which satisfactorily describes all aspects of the “Fenton-like” process. ► Low Cu concentrations catalyze ongoing oxidant production in the presence of exogenous superoxide or H2O2.
Copper toxicity has been attributed to its potential as a catalyst for oxidative damage to tissues through redox cycling between Cu(I) and Cu(II), particularly in the presence of H2O2, a by-product of oxygen metabolism. In this study, the reactions of nanomolar concentrations of Cu(I) and Cu(II) with H2O2 have been investigated in 2.0mM NaHCO3 and 0.7M NaCl at pH 8.0. Measurements of both the formation of the hydroxylated phthalhydrazide chemiluminescent product and the degradation of formate in the absence and presence of compounds with well-known reactivity with HO indicated that the reaction between Cu(I) and H2O2 did not result in the production of HO but involved the formation of a higher oxidation state of copper, Cu(III). The Cu(III) so-formed reacts with the substrates that were present at much slower rates compared to those of HO. The rate of formation of HO from the dissociation of Cu(III) was extremely slow at pH 8.0 with the result that HO is not an important oxidant in this system. The rapid rate of reaction of Cu(III) with Cu(I) contributes significantly to the redox cycle of copper and the associated oxidizing capacity of the Cu(I)/Cu(II)/H2O2/O2 system with exogenous input of H2O2 and O2- exhibiting the ability to mediate ongoing copper-catalyzed production of the powerful oxidant, Cu(III).
To dissect therapeutic mechanisms of transplanted stem cells and develop exosome-based nanotherapeutics in treating autoimmune and neurodegenerative diseases, we assessed the effect of exosomes ...secreted from human mesenchymal stem cells (MSCs) in treating multiple sclerosis using an experimental autoimmune encephalomyelitis (EAE) mouse model. We found that intravenous administration of exosomes produced by MSCs stimulated by IFNγ (IFNγ-Exo) (i) reduced the mean clinical score of EAE mice compared to PBS control, (ii) reduced demyelination, (iii) decreased neuroinflammation, and (iv) upregulated the number of CD4+CD25+FOXP3+ regulatory T cells (Tregs) within the spinal cords of EAE mice. Co-culture of IFNγ-Exo with activated peripheral blood mononuclear cells (PBMCs) cells in vitro reduced PBMC proliferation and levels of pro-inflammatory Th1 and Th17 cytokines including IL-6, IL-12p70, IL-17AF, and IL-22 yet increased levels of immunosuppressive cytokine indoleamine 2,3-dioxygenase. IFNγ-Exo could also induce Tregs in vitro in a murine splenocyte culture, likely mediated by a third-party accessory cell type. Further, IFNγ-Exo characterization by deep RNA sequencing suggested that IFNγ-Exo contains anti-inflammatory RNAs, where their inactivation partially hindered the exosomes potential to induce Tregs. Furthermore, we found that IFNγ-Exo harbors multiple anti-inflammatory and neuroprotective proteins. These results not only shed light on stem cell therapeutic mechanisms but also provide evidence that MSC-derived exosomes can potentially serve as cell-free therapies in creating a tolerogenic immune response to treat autoimmune and central nervous system disorders.
The aim of this study was to examine the effect of different reference ranges in bone mineral density on the diagnosis of osteoporosis.
This cross-sectional study involved 357 men and 870 women aged ...between 18 and 89 years, who were randomly sampled from various districts within Ho Chi Minh City, Vietnam. BMD at the femoral neck, lumbar spine and whole body was measured by DXA (Hologic QDR4500). Polynomial regression models and bootstraps method were used to determine peak BMD and standard deviation (SD). Based on the two parameters, we computed T-scores (denoted by TVN) for each individual in the study. A similar diagnosis was also done based on T-scores provided by the densitometer (TDXA), which is based on the US White population (NHANES III). We then compared the concordance between TVN and TDXA in the classification of osteoporosis. Osteoporosis was defined according to the World Health Organization criteria.
In post-menopausal women, the prevalence of osteoporosis based on femoral neck TVN was 29%, but when the diagnosis was based on TDXA, the prevalence was 44%. In men aged 50+ years, the TVN-based prevalence of osteoporosis was 10%, which was lower than TDXA-based prevalence (30%). Among 177 women who were diagnosed with osteoporosis by TDXA, 35% were actually osteopenia by TVN. The kappa-statistic was 0.54 for women and 0.41 for men.
These data suggest that the T-scores provided by the Hologic QDR4500 over-diagnosed osteoporosis in Vietnamese men and women. This over-diagnosis could lead to over-treatment and influence the decision of recruitment of participants in clinical trials.
Hypomagnesemia: a clinical perspective Pham, Phuong-Chi T; Pham, Phuong-Anh T; Pham, Son V ...
International journal of nephrology and renovascular disease,
01/2014, Letnik:
7, Številka:
default
Journal Article
Recenzirano
Odprti dostop
Although magnesium is involved in a wide spectrum of vital functions in normal human physiology, the significance of hypomagnesemia and necessity for its treatment are under-recognized and ...underappreciated in clinical practice. In the current review, we first present an overview of the clinical significance of hypomagnesemia and normal magnesium metabolism, with a focus on renal magnesium handling. Subsequently, we review the literature for both congenital and acquired hypomagnesemic conditions that affect the various steps in normal magnesium metabolism. Finally, we present an approach to the routine evaluation and suggested management of hypomagnesemia.
Distant-acting tissue-specific enhancers, which regulate gene expression, vastly outnumber protein-coding genes in mammalian genomes, but the functional importance of this regulatory complexity ...remains unclear. Here we show that the pervasive presence of multiple enhancers with similar activities near the same gene confers phenotypic robustness to loss-of-function mutations in individual enhancers. We used genome editing to create 23 mouse deletion lines and inter-crosses, including both single and combinatorial enhancer deletions at seven distinct loci required for limb development. Unexpectedly, none of the ten deletions of individual enhancers caused noticeable changes in limb morphology. By contrast, the removal of pairs of limb enhancers near the same gene resulted in discernible phenotypes, indicating that enhancers function redundantly in establishing normal morphology. In a genetic background sensitized by reduced baseline expression of the target gene, even single enhancer deletions caused limb abnormalities, suggesting that functional redundancy is conferred by additive effects of enhancers on gene expression levels. A genome-wide analysis integrating epigenomic and transcriptomic data from 29 developmental mouse tissues revealed that mammalian genes are very commonly associated with multiple enhancers that have similar spatiotemporal activity. Systematic exploration of three representative developmental structures (limb, brain and heart) uncovered more than one thousand cases in which five or more enhancers with redundant activity patterns were found near the same gene. Together, our data indicate that enhancer redundancy is a remarkably widespread feature of mammalian genomes that provides an effective regulatory buffer to prevent deleterious phenotypic consequences upon the loss of individual enhancers.
Background
Osmotic demyelination syndrome (ODS) is a complication generally associated with overly rapid correction of hyponatremia. Traditionally, nephrologists have been trained to focus solely on ...limiting the correction rate. However, there is accumulating evidence to suggest that the prevention of ODS is beyond achieving slow correction rates.
Methods
We (1) reviewed the literature for glial intracellular protective alterations during hyperosmolar stress, a state presumed equivalent to the rapid correction of hyponatremia, and (2) analyzed all available hyponatremia-associated ODS cases from PubMed for possible contributing factors including correction rates and concurrent metabolic disturbances involving hypokalemia, hypophosphatemia, hypomagnesemia, and/or hypoglycemia.
Results
In response to acute hyperosmolar stress, glial cells undergo immediate extracellular free water shift, followed by active intracellular Na
+
, K
+
and amino acid uptake, and eventual idiogenic osmoles synthesis. At minimum, protective mechanisms require K
+
, Mg
2+
, phosphate, amino acids, and glucose. There were 158 cases of hyponatremia-associated ODS where both correction rates and other metabolic factors were documented. Compared with the rapid correction group (>0.5 mmol/L/h), the slow correction group (≤0.5 mmol/L/h) had a greater number of cases with concurrent hypokalemia (49.4 vs. 33.3 %,
p
= 0.04), and a greater number of cases with any concurrent metabolic derangements (55.8 vs. 38.3 %,
p
= 0.03).
Conclusion
Glial cell minimizes volume changes and injury in response to hyperosmolar stress via mobilization and/or utilization of various electrolytes and metabolic factors. The prevention of ODS likely requires both minimization of correction rate and optimization of intracellular response during the correction phase when a sufficient supply of various factors is necessary.
Hypomagnesemia has been implicated in adversely affecting diabetic complications. This is a retrospective study designed to determine whether there is any association between serum magnesium ...concentration Mg2+ and the rate of renal function deterioration, as determined by the slope of serum creatinine reciprocals versus time (1/SCr-vs-t), in patients with diabetes mellitus type 2 (DM2).
DM2 patients without known kidney disease seen at Olive View-UCLA Medical Center for any reason during January-March 2001 were included. For each patient, all available data from our electronic database for Mg2+, hemoglobin A(1C) (HbA(1C), serum creatinine (SCr), lipid profiles, routine urinary analysis, as well as history of hypertension and pharmacy profiles were retrieved. The average of all parameters obtained and linear regression analyses for the slope of 1/SCr-vs-t plot were performed for each patient. Patients were stratified by gender and divided into four groups based on increasing Mg2+. Correlations between each parameter including the slope of 1/SCr-vs-t and the four magnesium groups were analyzed.
252 males and 298 females with a mean follow-up of 62.6 +/- 22.5 months were included. Patients belonging to lower Mg2+ groups for both genders had significantly worse slopes of 1/SCr-vs-t plot independent of the presence of hypertension and use of ACEI/ARB, diuretics, HMG-CoA enzyme inhibitors or aspirin. In a multivariate regression analysis controlling for age, HbA(1C) and various components of the lipid profile, Mg2+ remained an independent predictor for the slope of 1/SCr-vs-t. A trend for worse proteinuria based on routine urinary analysis was observed among patients belonging to the lowest Mg2+ group.
Lower Mg2+ is associated with a faster renal function deterioration rate in DM2 patients.
The association between vitamin D status and insulin resistance (IR) has been less studied among Asians, and it remains elusive whether calcium could modify such an association. We examined the ...association of serum 25-hydroxyvitamin D (25(OH)D) concentrations with IR markers and the potential effect modification by calcium intake among a Japanese population.
The authors analyzed data (n=494) from a cross-sectional survey conducted in 2009 among a Japanese working population aged 20-68 years. Fasting serum 25(OH)D and insulin, as well as fasting plasma glucose were determined, and homeostatic model assessment of IR (HOMA-IR) was calculated. Calcium intake was assessed using a validated diet history questionnaire. Multiple linear regression was done with adjustment of potential confounding variables.
Fasting insulin and HOMA-IR were significantly inversely associated with 25(OH)D concentration across quartiles of 25(OH)D after fully adjusting for covariates (P(trend)=0.04 and 0.02, respectively). Across clinically relevant categories of 25(OH)D, compared with participants in the vitamin D sufficiency group, those in the vitamin D insufficiency group had a 5% higher HOMA-IR score, and those in the hypovitaminosis D group had an 18% higher HOMA-IR score (P(trend)=0.01). In an analysis by calcium intake, the HOMA-IR score was highest among participants with both a low calcium intake and lowest 25(OH)D concentrations, with significant inverse trend being observed in the group with lower calcium intake (P(trend)=0.02).
Our findings suggest that low vitamin D status is associated with IR among Japanese adults.
Hypomagnesemia in patients with type 2 diabetes Pham, Phuong-Chi T; Pham, Phuong-Mai T; Pham, Son V ...
Clinical journal of the American Society of Nephrology
2, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Hypomagnesemia has been reported to occur at an increased frequency among patients with type 2 diabetes compared with their counterparts without diabetes. Despite numerous reports linking ...hypomagnesemia to chronic diabetic complications, attention to this issue is poor among clinicians. This article reviews the literature on the metabolism of magnesium, incidence of hypomagnesemia in patients with type 2 diabetes, implicated contributing factors, and associated complications. Hypomagnesemia occurs at an incidence of 13.5 to 47.7% among patients with type 2 diabetes. Poor dietary intake, autonomic dysfunction, altered insulin metabolism, glomerular hyperfiltration, osmotic diuresis, recurrent metabolic acidosis, hypophosphatemia, and hypokalemia may be contributory. Hypomagnesemia has been linked to poor glycemic control, coronary artery diseases, hypertension, diabetic retinopathy, nephropathy, neuropathy, and foot ulcerations. The increased incidence of hypomagnesemia among patients with type 2 diabetes presumably is multifactorial. Because current data suggest adverse outcomes in association with hypomagnesemia, it is prudent to monitor magnesium routinely in this patient population and treat the condition whenever possible.
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