Influence of Vegetation on Long-term Phosphorus Sequestration in Subtropical Treatment Wetlands

Sustainable operation of a treatment wetland depends on its continued treatment of influent water to achieve desired outflow water quality targets. Water treatment or nutrient reduction is attained by a combination of biotic and abiotic processes. We studied one of the world's largest treatment wetlands established to revive the Florida Everglades from impacts of excessive phosphorus (P) inputs. Phosphorus retained in the treatment wetlands is sequestered within the accumulated material via biotic and abiotic pathways that are influenced by the existing wetland vegetation. Recently accreted soils (RAS) provide a major sink for stored P, and long-term P removal efficiency of treatment wetlands is governed by the stability of accreted P because more stable P pools are less susceptible to mobilization and loss. We quantified reactive P (extracted with acid and alkali) and nonreactive P (not extracted with acid and alkali) pools in wetland soils by using an operationally defined P fractionation scheme and assessed the effect of emergent vs. submerged vegetation communities on stability of sequestered P. Reactive P comprised 63 to 79% of total P in wetland soils without a clear difference between two vegetation groups. The quantities of reactive P forms (inorganic vs. organic P) were significantly different between two vegetation types. A higher proportion of reactive P was stored as organic P in flocculent detrital organic matter (floc) and RAS under emergent vegetation (46-47% total P) in comparison with submerged vegetation (21-34% total P). The dominant P removal pathway in the submerged vegetation system was associated with calcium whereas plant uptake and peat burial appeared to be the main pathway in the emergent vegetation system.

Safety and efficacy of sofosbuvir-based direct-acting antiviral regimens for hepatitis C virus genotypes 1-4 and 6 in Myanmar: Real-world experience

This open-label, clinical experience investigated the safety and efficacy of direct-acting antiviral (DAA) hepatitis C virus (HCV) therapy in Myanmar; 344 patients completed treatment between June 2015 and May 2016. Patients with HCV genotypes 1-4 and 6 received one of four treatments: (i) Peg-interferon (PEG-IFN)+sofosbuvir (SOF)+ribavirin (RBV) for 12 weeks, (ii) SOF+RBV for 24 weeks, (iii) ledipasvir (LDV)+SOF for 12 weeks or (iv) daclatasvir (DCV)+SOF+RBV for 12 or 24 weeks. Genotype 3 was most common (n=133, 38.7%), followed by genotype 6 (n=122, 35.5%) and genotype 1 (n=86, 25%). Overall, 91% of patients achieved sustained virologic response (SVR); 99% in group 1, (n=148/149), 90% in group 2 (n=95/106), 78% in group 3 (n=65/83) and 100% in group 4 (n=6/6). In group 3, SVR rates were 96.8% in genotype 1 (n=30/31) and 64.1% in genotype 6 (n=25/39). Multivariable regression analysis identified advanced fibrosis (F3-4) (OR=.16 CI: 0.05-0.57, P=.005), genotype 6 (OR=.35, CI: 0.16-0.79, P=.012) and diabetes (OR=.29, CI: 0.12-0.71, P=.007) as negative independent predictors of response. Adverse events were mild with all-oral therapy.

CONCLUSION

DAA therapy ±PEG-IFN achieved high SVR rates. Genotype 6 patients had a low SVR to 12 weeks of LDV and SOF raising the need for other regimens, RBV or longer treatment duration in this population.

Effect of viral suppression on hepatic venous pressure gradient in hepatitis C with cirrhosis and portal hypertension

Portal hypertension is a predictor of liver-related clinical events and mortality in patients with hepatitis C and cirrhosis. The effect of interferon-free hepatitis C treatment on portal pressure is unknown. Fifty patients with Child-Pugh-Turcotte (CPT) A and B cirrhosis and portal hypertension (hepatic venous pressure gradient [HVPG] >6 mm Hg) were randomized to receive 48 weeks of open-label sofosbuvir plus ribavirin at Day 1 or after a 24-week observation period. The primary endpoint was sustained virologic response 12 weeks after therapy (SVR12) in patients who received ≥1 dose of treatment. Secondary endpoints included changes in HVPG, laboratory parameters, and MELD and CPT scores. A subset of patients was followed 48 weeks posttreatment to determine late changes in HVPG. SVR12 occurred in 72% of patients (33/46). In the 37 patients with paired HVPG measurements at baseline and the end of treatment, mean HVPG decreased by -1.0 (SD 3.97) mm Hg. Nine patients (24%) had ≥20% decreases in HVPG during treatment. Among 39 patients with pretreatment HVPG ≥12 mm Hg, 27 (69%) achieved SVR12. Four of the 33 (12%) patients with baseline HVPG ≥12 mm Hg had HVPG <12 mm Hg at the end of treatment. Of nine patients with pretreatment HVPG ≥12 mm Hg who achieved SVR12 and completed 48 weeks of follow-up, eight (89%) had a ≥20% reduction in HVPG, and three reduced their pressure to <12 mm Hg. Patients with chronic HCV and compensated or decompensated cirrhosis who achieve SVR can have clinically meaningful reductions in HVPG at long-term follow-up. (EudraCT 2012-002457-29).

Acute Kidney Injury in Cirrhosis: Baseline Serum Creatinine Predicts Patient Outcomes

OBJECTIVES

The International Ascites Club (IAC) recently defined Stage 1 acute kidney injury (AKI) for cirrhosis as an acute increase in serum creatinine (SCr) by ≥0.3 mg/dl or by ≥50% in <48 h from a stable value within 3 months. The baseline SCr may influence AKI risk and patient outcomes. The objective of this study is to determine in cirrhosis whether the baseline SCr has any effect on the in-hospital AKI course and patient survival.

METHODS

North American Consortium for the Study of End-Stage Liver Disease is a consortium of tertiary-care hepatology centers prospectively enroling non-elective cirrhotic inpatients. Patients with different baseline SCr levels (≤0.5, 0.51-1.0, 1.01-1.5, >1.5 mg/dl) were evaluated for the development of AKI, and compared for AKI outcomes and 30-day survival.

RESULTS

653 hospitalized cirrhotics (56.7±10years, 64% men, 30% with infection) were included. The incidence of AKI was 47% of enrolled patients. Patients with higher baseline SCr were more likely to develop AKI, with significantly higher delta and peak SCr (P<0.001) than the other groups, more likely to have a progressive AKI course (P<0.0001), associated with a significantly reduced 30-day survival (P<0.0001). Multivariate logistic regression showed that the delta SCr during an AKI episode to be the strongest factor impacting AKI outcomes and survival (P<0.001), with a delta SCr of 0.70 mg/dl having a 68% sensitivity and 80% specificity for predicting 30-day mortality.

CONCLUSIONS

Admitted cirrhotic patients with higher baseline SCr are at higher risk for in-hospital development of AKI, and more likely to have AKI progression with reduced survival. Therefore, such patients should be closely monitored and treated promptly for their AKI.

Chronic hepatitis C and chronic kidney disease: Advances, limitations and unchartered territories

Over the past few years, treatment options for chronic hepatitis C virus (HCV) infection have evolved dramatically. The current approved interferon-free direct-acting antiviral (DAA) regimens have been shown to be safe and effective with sustained virologic response (SVR) rates of >90% in most patients. Unique issues yet remain such as the challenges in patients with impaired renal function or decompensated cirrhosis. Patients with stages 4-5 chronic kidney disease (CKD) have a higher prevalence of HCV infection compared with the general population. Chronic HCV in those on dialysis and in kidney transplant recipients is associated with higher morbidity and mortality than uninfected patients. The HCV-infected population is also at risk of developing extrahepatic manifestations associated with altered immune system function and chronic inflammation with cryoglobulinaemic vasculitis being the most common of these manifestations. Therefore, patients with CKD stages 4-5 have to be considered priority patients for HCV therapy. New antiviral therapies have the potential to improve outcomes in this vulnerable patient population, including those on haemodialysis. Recently published studies conducted in kidney transplant recipients have demonstrated successful outcomes. It is thus essential that we carefully select the most appropriate DAA regimen and the best time for treatment in the context of kidney transplantation or cryoglobulinaemic vasculitis. While sofosbuvir, the only approved nucleotide NS5B inhibitor, has been the backbone of most pangenotypic therapeutic regimens, it has a limitation in those with advanced kidney disease. The currently approved regimens for those with stage 4/5 CKD, while effective, have challenges in that they apply to genotype 1/4 and may require RBV for genotype 1a. Globally, genotype 3 is a common infection, and thus, this group with CKD presents a huge unmet need for effective therapies. As therapy of HCV in renal transplant recipients has been highly successful, it provides an opportunity to expand the use of HCV-infected organs in solid organ transplantation.

Evaluation of Ageratum conyzoides in field scale constructed wetlands (CWs) for domestic wastewater treatment

Ageratum conyzoides were evaluated in field scale subsurface flow constructed wetlands (CWs) to quantify its nitrogen (N) and phosphorus (P) uptake and compare with wetland plants (Pistia stratiotes, Typha latifolia and Canna indica). The two-field scale subsurface flow CWs, located in the International Crops Research Institute for Semi-Arid Tropics, received wastewater from an urban colony. The CW1 and CW2 had the same dimensions (length:10 m, width:3 m, total depth:1.5 m and sand and gravel:1 m), similar flow rates (3 m³/d), hydraulic loading rates (HLRs-10 cm/d) and hydraulic retention time (HRT-5 days) from July 2014-August 2015. The vegetation in both CWs consisted of Pistia stratiotes, Typha latifolia, Canna indica, and Ageratum conyzoides, respectively. The CW1 (% reduction with respect to concentrations) reduced total suspended solids (TSS) (68%), NH₄-N (26%), NO₃-N (30%), soluble reactive P (SRP) (20%), chemical oxygen demand (COD) (45%) and fecal coliforms (71%), while the CW2 (%-reduction with respect to concentrations) reduced TSS (63%), NH₄-N (32%), NO₃-N (26%), SRP (35%), COD (39%) and fecal coliforms (70%). Ageratum conyzoides can be used in combination with Pistia stratiotes, Typha latifolia and Canna indica to enhance removal of excessive N, P and fecal coliforms from domestic wastewater.

Ledipasvir-sofosbuvir and sofosbuvir plus ribavirin in patients with chronic hepatitis C and bleeding disorders

INTRODUCTION

Chronic hepatitis C virus (HCV) infection is prevalent among patients with inherited bleeding disorders and is a leading cause of mortality in those with haemophilia.

AIM

We evaluated the efficacy and safety of ledipasvir-sofosbuvir and sofosbuvir plus ribavirin in patients with chronic HCV genotype 1-4 infection and an inherited bleeding disorder.

METHODS

Ledipasvir-sofosbuvir was administered for 12 weeks to patients with genotype 1 or 4 infection and for 12 or 24 weeks to treatment-experienced cirrhotic patients with genotype 1 infection. Patients with genotype 2 and 3 infection received sofosbuvir plus ribavirin for 12 and 24 weeks respectively.

RESULTS

The majority of the 120 treated patients had a severe bleeding disorder (55%); overall, 65% of patients had haemophilia A and 26% of patients had haemophilia B; 22% were HIV coinfected. Sustained virologic response at 12 weeks posttreatment was 99% (98/99) in patients with genotype 1 or 4 infection; 100% (5/5) in treatment-experienced cirrhotic patients with genotype 1 infection; 100% (10/10) in patients with genotype 2 infection; and 83% (5/6) in patients with genotype 3 infection. There were no treatment discontinuations due to adverse events (AEs). The most frequent non-bleeding AEs were fatigue, headache, diarrhoea, nausea and insomnia. Bleeding AEs occurred in 22 patients, of which all but one were considered unrelated to treatment.

CONCLUSION

Treatment with ledipasvir-sofosbuvir for patients with HCV genotype 1 or 4 infection or sofosbuvir plus ribavirin for patients with genotype 2 or 3 infection was highly effective and well tolerated among those with inherited bleeding disorders.

All-oral direct-acting antiviral therapy in HCV-advanced liver disease is effective in real-world practice: observations through HCV-TARGET database

BACKGROUND

Chronic hepatitis C virus therapy in patients with advanced liver disease remains a clinical challenge. HCV-TARGET collects data in patients treated at tertiary academic and community centres.

AIM

To assess efficacy of all-oral HCV therapy in advanced liver disease.

METHODS

Between December 2013 and October 2014, 240 patients with a MELD score of ≥10 initiated HCV treatment with an all-oral regimen. Data from the 220 patients who completed 12-week follow-up were analysed.

RESULTS

Genotype 1 (GT1) patients had higher sustained virological response (SVR) when treated with sofosbuvir plus simeprevir ± ribavirin than with sofosbuvir plus ribavirin (66-74% vs. 54%); GT1b vs GT1a (84% vs. 64%). SVR for GT2 was 72% with sofosbuvir plus ribavirin, while GT3 patients had a substantially lower response (35%). A decrease in MELD score was not clearly related to SVR over the short course of follow-up although some had improvements in MELD score, serum bilirubin and albumin. A predictor of virological response was albumin level while negative predictors were elevated bilirubin level and GT1a. Most patients with GT1 were treated with approximately 12-week duration of sofosbuvir and simeprevir ± ribavirin therapy while GT2 and GT3 patients were treated with approximately 12 and 24 weeks of sofosbuvir plus ribavirin respectively.

CONCLUSIONS

All-oral therapies are effective among patients with advanced liver disease with high levels of success in GT2 and GT1b, and may serve to reduce the severity of liver disease after SVR. Treatment for GT3 patients remains an unmet need. Clinical trial number: NCT01474811.

Review article: safety and tolerability of direct-acting anti-viral agents in the new era of hepatitis C therapy

BACKGROUND

Direct-acting anti-virals (DAAs) licensed to treat chronic HCV infection have revolutionised treatment algorithms by drastically mitigating side effects while enhancing efficacy relative to interferon-based therapy.

AIM

To review adverse events (AEs) uniquely associated with DAA therapy across a broad spectrum of patient populations.

METHODS

Searches of PubMed and FDA surveillance studies were undertaken to complete an exhaustive review. Search terms included 'DAAs', 'safety', and 'tolerability'.

RESULTS

While DAAs are remarkably well tolerated, they are accompanied by unique AEs. Simeprevir, an NS3/4A protease inhibitor, has been known, albeit infrequently, to cause mild hyperbilirubinemia and photosensitivity reactions; and paritaprevir boosted with ritonavir causes bilirubin and ALT elevations. Asunaprevir, another protease inhibitor, infrequently causes elevated transaminase levels. NS5A and NS5B inhibitors are well tolerated, although sofosbuvir is contraindicated in patients with severe renal impairment. Ribavirin co-administered in certain treatment regimens has been associated with cough, rash and haemolytic anaemia.

CONCLUSIONS

With the impending reality of a more tolerable interferon-sparing regimen, the future of DAA therapy offers shorter treatment duration, simplified disease management, and a patient-centred regimen. With advantages come drawbacks, including development of resistance to therapy and accessibility to this expensive treatment. DAA therapy continues to advance at a brisk pace with a promising trend for higher tolerability, even in difficult-to-treat subgroups such as those with cirrhosis, nonresponders to prior therapy, and transplant recipients. Subgroup-specific contraindications and safety-related limitations are active areas of research. Concerted research efforts and continuing advances lend hope to the goal of rendering HCV a routinely curable disease.

Comparative Proteomic Analysis of Cotton Fiber Development and Protein Extraction Method Comparison in Late Stage Fibers

The distinct stages of cotton fiber development and maturation serve as a single-celled model for studying the molecular mechanisms of plant cell elongation, cell wall development and cellulose biosynthesis. However, this model system of plant cell development is compromised for proteomic studies due to a lack of an efficient protein extraction method during the later stages of fiber development, because of a recalcitrant cell wall and the presence of abundant phenolic compounds. Here, we compared the quality and quantities of proteins extracted from 25 dpa (days post anthesis) fiber with multiple protein extraction methods and present a comprehensive quantitative proteomic study of fiber development from 10 dpa to 25 dpa. Comparative analysis using a label-free quantification method revealed 287 differentially-expressed proteins in the 10 dpa to 25 dpa fiber developmental period. Proteins involved in cell wall metabolism and regulation, cytoskeleton development and carbohydrate metabolism among other functional categories in four fiber developmental stages were identified. Our studies provide protocols for protein extraction from maturing fiber tissues for mass spectrometry analysis and expand knowledge of the proteomic profile of cotton fiber development.

Soil and phosphorus accretion rates in sub-tropical wetlands: Everglades Stormwater Treatment Areas as a case example

Wetlands are known to serve as sinks for particulate matter and associated nutrients and contaminants. Consequently rate of soil accretion is critical for continued performance of wetlands to provide ecosystem services including water quality improvement and reduce excess contaminant loads into downstream waters. Here we demonstrate a new technique to determine rate of soil accretion in selected subtropical treatment wetlands located in southern USA. We also report changes in soil accretion rates and subsequent phosphorus (P) removal efficiency with increasing operational history of these treatment wetlands. Utilizing discernible signatures preserved within the soil depth profiles, 'change points' (CP) that corresponded to specific events in the life history of a wetland were determined. The CP was observed as an abrupt transition in the physico-chemical properties of soil as a manifestation of prevailing historical conditions (e.g. startup of treatment wetlands in this case). Vertical depth of CP from the soil surface was equivalent to the depth of recently accreted soil (RAS) and used for soil accretion rate calculations. Annual soil and P accretion rates determined using CP technique (CPT) in studied wetlands ranged from 1.0±0.3 to 1.7±0.8 cm yr(-1) and 1.3±0.6 to 3.3±2 g m(-2) yr(-1), respectively. There was no difference in RAS depth between emergent and submerged aquatic vegetation communities found at the study location. Our results showed that soil and P accretion rates leveled off after 10 yr of treatment wetlands' operation. On comparison, soil accretion rates and RAS depth determined by CPT were commensurate with that measured by other techniques. CPT can be easily used where a reliable record of wetland establishment date or some significant alteration/perturbation is available. This technique offers a relatively simple alternative to determine vertical accretion rates in free-water surface wetlands.

Evaluation of Legacy Phosphorus Storage and Release from Wetland Soils

To better manage legacy phosphorus (P) in watersheds, reliable techniques to predict P storage and release from uplands, ditches, streams, and wetlands must be developed. Techniques such as the P saturation ratio (PSR) and the soil P storage capacity (SPSC), originally developed for upland soils, are hypothesized to be applicable to wetland soils as well. Surface soils were collected from eight beef ranches within the Lake Okeechobee Watershed, FL, to obtain a threshold PSR value and to evaluate the use of PSR and SPSC for identifying legacy P storage and release from wetland soils. Water-soluble P (WSP) was determined for all soils; the equilibrium P concentration (EPC) was determined for selected soils through the generation of Langmuir isotherms. The threshold PSR for wetland soils, calculated from P, Fe, and Al in a Mehlich 1 solution, was determined to be 0.1; SPSC, calculated using the threshold PSR, was found to be related to WSP. When SPSC was positive, WSP and EPC were minimal. However, both WSP and EPC increased once SPSC became negative. Organic matter (OM) varied from 0.4 to 90 g kg for both positive and negative SPSC, suggesting that OM in wetland soils does not have any effect on P retention and release below the threshold PSR. Moreover, when a wetland or drainage ditch is heavily P impacted, it could be a P source; wetland vegetation may no longer be able to assimilate additional P, resulting in P loss from the soil. This study suggests that the PSR-SPSC concept could be a valuable tool for evaluating legacy P release from wetlands.

HOI-02 induces apoptosis and G2-M arrest in esophageal cancer mediated by ROS

Reactive oxygen species (ROS) are chemically reactive molecules that perform essential functions in living organisms. Accumulating evidence suggests that many types of cancer cells exhibit elevated levels of ROS. Conversely, generation of ROS has become an effective method to kill cancer cells. (E)-3-hydroxy-3-(4-(4-nitrophenyl)-2-oxobut-3-en-1-yl) indolin-2-one, which is an NO2 group-containing compound designated herein as HOI-02, generated ROS and, in a dose-dependent manner, decreased esophageal cancer cell viability and inhibited anchorage-independent growth, followed by apoptosis and G2-M arrest. Moreover, results of an in vivo study using a patient-derived xenograft mouse model showed that HOI-02 treatment suppressed the growth of esophageal tumors, without affecting the body weight of mice. The expression of Ki-67 was significantly decreased with HOI-02 treatment. In addition, the phosphorylation of c-Jun, and expression of p21, cleaved caspase 3, and DCFH-DA were increased in the HOI-02-treated group compared with the untreated control group. In contrast, treatment of cells with (E)-3-(4-(4-aminophenyl)-2-oxobut-3-en-1-yl)-3-hydroxyindolin-2-one, which is an NH2 group-containing compound designated herein as HOI-11, had no effect. Overall, we identified HOI-02 as an effective NO2 group-containing compound that was an effective therapeutic or preventive agent against esophageal cancer cell growth.

One-year mortality in patients with bone and soft tissue sarcomas as an indicator of delay in presentation

INTRODUCTION

For many cancers, one-year mortality following diagnosis is a reflection of either advanced stage at diagnosis, multiple co-morbidities and/or complications of treatment. One-year mortality has not been reported for soft tissue or bone sarcomas. This study reports 1-year sarcoma mortality data over a 25-year period, investigates prognostic factors and considers whether a delay in presentation affects 1-year mortality.

METHODS

A total of 4,945 newly diagnosed bone sarcoma and soft tissue sarcoma patients were identified from a prospectively maintained, single institution oncology database. Of these, 595 (12%) died within 1 year of diagnosis. Both patient factors and tumour characteristics available at diagnosis were analysed for effect.

RESULTS

There was significant variation in one-year mortality between different histological subtypes. There has been no significant change in mortality rate during the last 25 years (mean: 11.7%, standard deviation: 2.8 percentage points). Soft tissue sarcoma patients who survived over one year reported a longer duration of symptoms preceding diagnosis than those who died (median: 26 vs 20 weeks, p<0.001). Prognostic factors identified in both bone and soft tissue sarcomas mirrored those for mid to long-term survival, with high tumour stage, large tumour size, metastases at diagnosis and increasing age having the greatest predictive effect.

CONCLUSIONS

One-year mortality in bone and soft tissue sarcoma patients is easy to measure, and could be a proxy for late presentation and therefore a potential performance indicator, similar to other cancers. It is possible to predict the risk of one-year mortality using factors available at diagnosis. Death within one year does not correlate with a long history but is associated with advanced disease at diagnosis.