Genomes to natural products PRediction Informatics for Secondary Metabolomes (PRISM)

Microbial natural products are an invaluable source of evolved bioactive small molecules and pharmaceutical agents. Next-generation and metagenomic sequencing indicates untapped genomic potential, yet high rediscovery rates of known metabolites increasingly frustrate conventional natural product screening programs. New methods to connect biosynthetic gene clusters to novel chemical scaffolds are therefore critical to enable the targeted discovery of genetically encoded natural products. Here, we present PRISM, a computational resource for the identification of biosynthetic gene clusters, prediction of genetically encoded nonribosomal peptides and type I and II polyketides, and bio- and cheminformatic dereplication of known natural products. PRISM implements novel algorithms which render it uniquely capable of predicting type II polyketides, deoxygenated sugars, and starter units, making it a comprehensive genome-guided chemical structure prediction engine. A library of 57 tailoring reactions is leveraged for combinatorial scaffold library generation when multiple potential substrates are consistent with biosynthetic logic. We compare the accuracy of PRISM to existing genomic analysis platforms. PRISM is an open-source, user-friendly web application available at http://magarveylab.ca/prism/.     

Generating Triangulated Macromolecular Surfaces by Euclidean Distance Transform

Macromolecular surfaces are fundamental representations of their three-dimensional geometric shape. Accurate calculation of protein surfaces is of critical importance in the protein structural and functional studies including ligand-protein docking and virtual screening. In contrast to analytical or parametric representation of macromolecular surfaces, triangulated mesh surfaces have been proved to be easy to describe, visualize and manipulate by computer programs. Here, we develop a new algorithm of EDTSurf for generating three major macromolecular surfaces of van der Waals surface, solvent-accessible surface and molecular surface, using the technique of fast Euclidean Distance Transform (EDT). The triangulated surfaces are constructed directly from volumetric solids by a Vertex-Connected Marching Cube algorithm that forms triangles from grid points. Compared to the analytical result, the relative error of the surface calculations by EDTSurf is <2–4% depending on the grid resolution, which is 1.5–4 times lower than the methods in the literature; and yet, the algorithm is faster and costs less computer memory than the comparative methods. The improvements in both accuracy and speed of the macromolecular surface determination should make EDTSurf a useful tool for the detailed study of protein docking and structure predictions. Both source code and the executable program of EDTSurf are freely available at http://zhang.bioinformatics.ku.edu/EDTSurf.     

Dew water isotopic ratios and their relationships to ecosystem water pools and fluxes in a cropland and a grassland in China

Dew formation has the potential to modulate the spatial and temporal variations of isotopic contents of atmospheric water vapor, oxygen and carbon dioxide. The goal of this paper is to improve our understanding of the isotopic interactions between dew water and ecosystem water pools and fluxes through two field experiments in a wheat/maize cropland and in a short steppe grassland in China. Measurements were made during 94 dew events of the D and ¹⁸O compositions of dew, atmospheric vapor, leaf, xylem and soil water, and the whole ecosystem water flux. Our results demonstrate that the equilibrium fractionation played a dominant role over the kinetic fractionation in controlling the dew water isotopic compositions. A significant correlation between the isotopic compositions of leaf water and dew water suggests a large role of top-down exchange with atmospheric vapor controlling the leaf water turnover at night. According to the isotopic labeling, dew water consisted of a downward flux of water vapor from above the canopy (98%) and upward fluxes originated from soil evaporation and transpiration of the leaves in the lower canopy (2%).     

Impact of Community Based Peer Support in Type 2 Diabetes: A Cluster Randomised Controlled Trial of Individual and/or Group Approaches

Background

Diabetes peer support, where one person with diabetes helps guide and support others, has been proposed as a way to improve diabetes management. We have tested whether different diabetes peer support strategies can improve metabolic and/or psychological outcomes.

Methods

People with type 2 diabetes (n = 1,299) were invited to participate as either ‘peer’ or ‘peer support facilitator’ (PSF) in a 2x2 factorial randomised cluster controlled trial across rural communities (130 clusters) in England. Peer support was delivered over 8–12 months by trained PSFs, supported by monthly meetings with a diabetes educator. Primary end point was HbA1c. Secondary outcomes included quality of life, diabetes distress, blood pressure, waist, total cholesterol and weight. Outcome assessors and investigators were masked to arm allocation. Main factors were 1:1 or group intervention. Analysis was by intention-to-treat adjusting for baseline.

Results

The 4 arms were well matched (Group n = 330, 1:1(individual) n = 325, combined n = 322, control n = 322); 1035 (79•7%) completed the mid-point postal questionnaire and 1064 (81•9%) had a final HbA1c. A limitation was that although 92.6% PSFs and peers were in telephone contact, only 61.4% of intervention participants attended a face to face session. Mean baseline HbA1c was 57 mmol/mol (7•4%), with no significant change across arms. Follow up systolic blood pressure was 2•3mm Hg (0.6 to 4.0) lower among those allocated group peer-support and 3•0mm Hg (1.1 to 5.0) lower if the group support was attended at least once. There was no impact on other outcomes by intention to treat or significant differences between arms in self-reported adherence or medication.

Conclusions

Group diabetes peer support over 8–12 months was associated with a small improvement in blood pressure but no other significant outcomes. Long term benefits should be investigated.

Trial Registration

ISRCTN.com ISRCTN6696362166963621     

Women with Pregnancies Had Lower Adherence to 1% Tenofovir Vaginal Gel as HIV Preexposure Prophylaxis in CAPRISA 004, a Phase IIB Randomized-Controlled Trial

Background

Antiretroviral prophylaxis may be a critical strategy to reduce periconception HIV transmission. Maximizing the benefit of periconception pharmacologic HIV risk-reduction requires an understanding of the links between pregnancy and adherence to this prevention strategy.

Methods

We assessed study gel adherence among women with pregnancies compared to women without pregnancies enrolled in the CAPRISA 004 phase IIB trial of 1% vaginal tenofovir gel. Pregnancy was assessed with monthly urine tests. Adherence was measured monthly and defined as proportion of sex acts covered by two returned, used applicators based on pre- and post-coital dosing. High adherence was defined as a median adherence score of >80%, that is, more than 80% of sex acts were covered by two applications of study gel. A multivariate generalized estimating equations (GEE) model with a binomial distribution was used to assess covariates associated with high adherence (>80%) over time. Median adherence before and after pregnancy was compared using Wilcoxon signed rank test.

Results

Among 868 women, 53 had at least 1 pregnancy (4.06 per 100 woman years, 95% CI: 3.04, 5.31). Women with pregnancies had lower median adherence compared to women without pregnancies (50% [IQR: 45–83] vs. 60% [IQR: 50–100], p = 0.02). Women with pregnancies also had a 48% lower odds of high adherence compared to women without pregnancies when adjusting for confounders (aOR 0.52, 95%CI: 0.41–0.66, p<0.0001). Among women with pregnancies, adherence before and after pregnancy was not different (50% [IQR: 46–83] vs. 55% [IQR: 20–100], p = 0.68).

Conclusions

Women with pregnancies were less likely to have high adherence to study gel compared to women without pregnancies. Understanding these differences may inform findings from HIV prevention trials and future implementation of antiretroviral prophylaxis for at-risk women who choose to conceive. The protocol for the parent trial is registered on ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT00441298","term_id":"NCT00441298"}}NCT00441298, http://www.clinicaltrials.gov/ct2/show/{"type":"clinical-trial","attrs":{"text":"NCT00441298","term_id":"NCT00441298"}}NCT00441298.     

Low numbers of blood and salivary natural killer cells are associated with a better response to belimumab in primary Sj?gren’s syndrome: results of the BELISS study

IntroductionIn this study, we sought to address changes in blood lymphocyte subpopulations and labial salivary gland (LSG) inflammation after belimumab treatment in patients with primary Sjögren’s syndrome (pSS) and to identify predictors of response to treatment.MethodsSequential blood lymphocyte subsets and LSG biopsies were analysed between week 0 (W0) and W28 in 15 patients with pSS treated with belimumab. Systemic response to treatment was defined as a decrease in the European League Against Rheumatism Sjögren’s Syndrome Disease Activity Index score of ≥3 points at W28.ResultsAfter belimumab, we observed a decrease in blood B lymphocytes primarily involving CD27-negative/immunoglobulin D–positive naïve B cells (p=0.008). Lymphocytic sialadenitis (focus score >1) that was present in 12 patients (80.0 %) before belimumab treatment became negative in 5 of them after treatment (p=0.03). The median (interquartile range) LSG B-cell/T-cell ratio decreased from 0.58 (0.5–0.67) to 0.50 (0.5–0.5) (p=0.06). B-cell activating factor (BAFF) staining was detected in 11 (78.6 %) of 14 patients before belimumab treatment compared with 7 (50.0 %) of 14 after belimumab therapy (p=0.10). The median percentage of BAFF-positive cells in foci significantly decreased from 27.5 % (10–40) to 5 % (0–20) (p=0.03). A systemic response was achieved in six patients (40 %). The only predictor of response was the presence of a low number of natural killer (NK) cells, both in blood (8.5 % [7–10] vs 11 % [9–21]; p=0.04) and in LSG (20.6/mm³ [20.0–21.4] vs 30.0/mm³ [25.0–100.0], p=0.003). Serum BAFF levels did not influence response to treatment.ConclusionsLow blood and salivary NK cell numbers are associated with a better response to belimumab. This suggests that two distinct subsets of pSS may exist: one with a predominant type I interferon (IFN)–BAFF–B-cell axis, representing good responders to belimumab; and one with a predominant type II IFN–NK cell axis, representing non-responders.

Trial registration

ClinicalTrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT01160666","term_id":"NCT01160666"}}NCT01160666. Registered 9 July 2010.     

Assessing Uncertainty in High-Resolution Spatial Climate Data across the US Northeast

Local and regional-scale knowledge of climate change is needed to model ecosystem responses, assess vulnerabilities and devise effective adaptation strategies. High-resolution gridded historical climate (GHC) products address this need, but come with multiple sources of uncertainty that are typically not well understood by data users. To better understand this uncertainty in a region with a complex climatology, we conducted a ground-truthing analysis of two 4 km GHC temperature products (PRISM and NRCC) for the US Northeast using 51 Cooperative Network (COOP) weather stations utilized by both GHC products. We estimated GHC prediction error for monthly temperature means and trends (1980–2009) across the US Northeast and evaluated any landscape effects (e.g., elevation, distance from coast) on those prediction errors. Results indicated that station-based prediction errors for the two GHC products were similar in magnitude, but on average, the NRCC product predicted cooler than observed temperature means and trends, while PRISM was cooler for means and warmer for trends. We found no evidence for systematic sources of uncertainty across the US Northeast, although errors were largest at high elevations. Errors in the coarse-scale (4 km) digital elevation models used by each product were correlated with temperature prediction errors, more so for NRCC than PRISM. In summary, uncertainty in spatial climate data has many sources and we recommend that data users develop an understanding of uncertainty at the appropriate scales for their purposes. To this end, we demonstrate a simple method for utilizing weather stations to assess local GHC uncertainty and inform decisions among alternative GHC products.     

A Randomized Trial Assessing the Safety and Immunogenicity of AS01 and AS02 Adjuvanted RTS,S Malaria Vaccine Candidates in Children in Gabon

Background

The malaria vaccine candidate antigen RTS,S includes parts of the pre-erythrocytic stage circumsporozoite protein fused to the Hepatitis B surface antigen. Two Adjuvant Systems are in development for this vaccine, an oil-in water emulsion – based formulation (AS02) and a formulation based on liposomes (AS01).

Methods & Principal Findings

In this Phase II, double-blind study ({"type":"clinical-trial","attrs":{"text":"NCT00307021","term_id":"NCT00307021"}}NCT00307021), 180 healthy Gabonese children aged 18 months to 4 years were randomized to receive either RTS,S/AS01_E or RTS,S/AS02_D, on a 0–1–2 month vaccination schedule. The children were followed-up daily for six days after each vaccination and monthly for 14 months. Blood samples were collected at 4 time-points. Both vaccines were well tolerated. Safety parameters were distributed similarly between the two groups. Both vaccines elicited a strong specific immune response after Doses 2 and 3 with a ratio of anti-CS GMT titers (AS02_D/AS01_E) of 0.88 (95% CI: 0.68–1.15) post-Dose 3. After Doses 2 and 3 of experimental vaccines, anti-CS and anti-HBs antibody GMTs were higher in children who had been previously vaccinated with at least one dose of hepatitis B vaccine compared to those not previously vaccinated.

Conclusions

RTS,S/AS01_E proved similarly as well tolerated and immunogenic as RTS,S/AS02_D, completing an essential step in the age de-escalation process within the RTS,S clinical development plan.

Trial Registration

ClinicalTrials.gov. {"type":"clinical-trial","attrs":{"text":"NCT00307021","term_id":"NCT00307021"}}NCT00307021     

Protective Efficacy and Safety of Three Antimalarial Regimens for the Prevention of Malaria in Young Ugandan Children: A Randomized Controlled Trial

Background

Chemoprevention offers a promising strategy for prevention of malaria in African children. However, the optimal chemoprevention drug and dosing strategy is unclear in areas of year-round transmission and resistance to many antimalarial drugs. To compare three available regimens, we conducted an open-label randomized controlled trial of chemoprevention in Ugandan children.

Methods and Findings

This study was conducted between June 28, 2010, and September 25, 2013. 400 infants were enrolled and 393 randomized at 6 mo of age to no chemoprevention, monthly sulfadoxine-pyrimethamine (SP), daily trimethoprim-sulfamethoxazole (TS), or monthly dihydroartemisinin-piperaquine (DP). Study drugs were administered at home without supervision. Piperaquine (PQ) levels were used as a measure of compliance in the DP arm. Participants were given insecticide-treated bednets, and caregivers were encouraged to bring their child to a study clinic whenever they were ill. Chemoprevention was stopped at 24 mo of age, and participants followed-up an additional year. Primary outcome was the incidence of malaria during the intervention period. During the intervention, the incidence of malaria in the no chemoprevention arm was 6.95 episodes per person-year at risk. Protective efficacy was 58% (95% CI, 45%–67%, p<0.001) for DP, 28% (95% CI, 7%–44%, p = 0.01) for TS, and 7% for SP (95% CI, −19% to 28%, p = 0.57). PQ levels were below the detection limit 52% of the time when malaria was diagnosed in the DP arm, suggesting non-adherence. There were no differences between the study arms in the incidence of serious adverse events during the intervention and the incidence of malaria during the 1-y period after the intervention was stopped.

Conclusions

For preventing malaria in children living in an area of high transmission intensity, monthly DP was the most efficacious and safe, although adherence may pose a problem. Monthly SP and daily TS may not be appropriate in areas with high transmission intensity and frequent resistance to antifolates.

Trial registration

www.ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00948896","term_id":"NCT00948896"}}NCT00948896 Please see later in the article for the Editors'' Summary     

Natural History of Cardiac and Respiratory Involvement,Prognosis and Predictive Factors for Long-Term Survival in Adult Patients with Limb Girdle Muscular Dystrophies Type 2C and 2D

BackgroundType 2C and 2D limb girdle muscular dystrophies (LGMD) are a group of autosomal recessive limb girdle muscular dystrophies manifested by proximal myopathy, impaired respiratory muscle function and cardiomyopathy. The correlation and the prognostic impact of respiratory and heart impairment are poorly described. We aimed to describe the long-term cardiac and respiratory follow-up of these patients and to determine predictive factors of cardio-respiratory events and mortality in LGMD 2C and 2D.MethodsWe reviewed the charts of 34 LGMD patients, followed from 2005 to 2015, to obtain echocardiographic, respiratory function and sleep recording data. We considered respiratory events (acute respiratory failure, pulmonary sepsis, atelectasis or pneumothorax), cardiac events (acute heart failure, significant cardiac arrhythmia or conduction block, ischemic stroke) and mortality as outcomes of interest for the present analysis.ResultsA total of 21 patients had type 2C LGMD and 13 patients had type 2D. Median age was 30 years [IQR 24–38]. At baseline, median pulmonary vital capacity (VC) was 31% of predicted value [20–40]. Median maximal inspiratory pressure (MIP) was 31 cmH₂O [IQR 20.25–39.75]. Median maximal expiratory pressure (MEP) was 30 cm H₂O [20–36]. Median left ventricular ejection fraction (LVEF) was 55% [45–64] with 38% of patients with LVEF <50%. Over a median follow-up of 6 years, we observed 38% respiratory events, 14% cardiac events and 20% mortality. Among baseline characteristics, LVEF and left ventricular end diastolic diameter (LVEDD) were associated with mortality, whilst respiratory parameters (VC, MIP, MEP) and the need for home mechanical ventilation (HMV) were associated with respiratory events.ConclusionIn our cohort of severely respiratory impaired type 2C and 2D LGMD, respiratory morbidity was high. Cardiac dysfunction was frequent in particular in LGMD 2C and had an impact on long-term mortality.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02501083","term_id":"NCT02501083"}}NCT02501083     

Preventing Acute Malnutrition among Young Children in Crises: A Prospective Intervention Study in Niger

Background

Finding the most appropriate strategy for the prevention of moderate acute malnutrition (MAM) and severe acute malnutrition (SAM) in young children is essential in countries like Niger with annual “hunger gaps.” Options for large-scale prevention include distribution of supplementary foods, such as fortified-blended foods or lipid-based nutrient supplements (LNSs) with or without household support (cash or food transfer). To date, there has been no direct controlled comparison between these strategies leading to debate concerning their effectiveness. We compared the effectiveness of seven preventive strategies—including distribution of nutritious supplementary foods, with or without additional household support (family food ration or cash transfer), and cash transfer only—on the incidence of SAM and MAM among children aged 6–23 months over a 5-month period, partly overlapping the hunger gap, in Maradi region, Niger. We hypothesized that distributions of supplementary foods would more effectively reduce the incidence of acute malnutrition than distributions of household support by cash transfer.

Methods and Findings

We conducted a prospective intervention study in 48 rural villages located within 15 km of a health center supported by Forum Santé Niger (FORSANI)/Médecins Sans Frontières in Madarounfa. Seven groups of villages (five to 11 villages) were allocated to different strategies of monthly distributions targeting households including at least one child measuring 60 cm–80 cm (at any time during the study period whatever their nutritional status): three groups received high-quantity LNS (HQ-LNS) or medium-quantity LNS (MQ-LNS) or Super Cereal Plus (SC+) with cash (€38/month [US$52/month]); one group received SC+ and family food ration; two groups received HQ-LNS or SC+ only; one group received cash only (€43/month [US$59/month]). Children 60 cm–80 cm of participating households were assessed at each monthly distribution from August to December 2011. Primary endpoints were SAM (weight-for-length Z-score [WLZ]<−3 and/or mid-upper arm circumference [MUAC]<11.5 cm and/or bipedal edema) and MAM (−3≤WLZ<−2 and/or 11.5≤MUAC<12.5 cm). A total of 5,395 children were included in the analysis (615 to 1,054 per group). Incidence of MAM was twice lower in the strategies receiving a food supplement combined with cash compared with the cash-only strategy (cash versus HQ-LNS/cash adjusted hazard ratio [HR] = 2.30, 95% CI 1.60–3.29; cash versus SC+/cash HR = 2.42, 95% CI 1.39–4.21; cash versus MQ-LNS/cash HR = 2.07, 95% CI 1.52–2.83) or with the supplementary food only groups (HQ-LNS versus HQ-LNS/cash HR = 1.84, 95% CI 1.35–2.51; SC+ versus SC+/cash HR = 2.53, 95% CI 1.47–4.35). In addition, the incidence of SAM was three times lower in the SC+/cash group compared with the SC+ only group (SC+ only versus SC+/cash HR = 3.13, 95% CI 1.65–5.94). However, non-quantified differences between groups, may limit the interpretation of the impact of the strategies.

Conclusions

Preventive distributions combining a supplementary food and cash transfer had a better preventive effect on MAM and SAM than strategies relying on cash transfer or supplementary food alone. As a result, distribution of nutritious supplementary foods to young children in conjunction with household support should remain a pillar of emergency nutritional interventions. Additional rigorous research is vital to evaluate the effectiveness of these and other nutritional interventions in diverse settings.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01828814","term_id":"NCT01828814"}}NCT01828814 Please see later in the article for the Editors'' Summary     

Use of Renin-Angiotensin System Inhibitors Is Associated with Reduction of Fracture Risk in Hemodialysis Patients

Background

Patients with chronic kidney disease, especially those undergoing dialysis treatment and having secondary hyperparathyroidism, have a high risk of bone fracture. The renin-angiotensin system (RAS) is associated with osteoclastic bone resorption. We aimed to examine whether the use of RAS inhibitors reduces the incidence of fracture in hemodialysis patients.

Methods and Findings

This was a multicenter, 3-year, prospective, observational study. From 2008 to 2011, maintenance hemodialysis patients with secondary hyperparathyroidism (N = 3,276) treated with angiotensin converting enzyme inhibitor (ACEI)/angiotensin II receptor blocker (ARB) at baseline were followed for a mean of 2.7 years. The association between the use of ACEI/ARB and hospitalization rate owing to fracture was examined by using Cox regression models. Effect modifications by the severity of secondary hyperparathyroidism (intact parathyroid hormone [iPTH] level), sex, and systolic blood pressure were also examined. The incidence proportion of fracture-related hospitalization was 5.42% throughout the observation period. ACEI/ARB use was associated with a lower rate of fracture-related hospitalization (adjusted hazard ratio, 0.65; 95% confidence interval [CI], 0.45–0.92). This association was not significantly affected by sex (P = 0.56) or systolic blood pressure levels (P = 0.87). The hazard ratios adjusted by iPTH levels were qualitatively different, but not statistically significant (P = 0.11): 0.77 (95% CI, 0.42–1.39), 0.38 (95% CI, 0.20–0.73), 0.59 (95% CI, 0.29–1.21), and 1.29 (95% CI, 0.58–2.42) for the first, second, third and fourth quartiles of iPTH, respectively.

Conclusions

Use of RAS inhibitors is associated with a lower rate of fracture-related hospitalization in hemodialysis patients with secondary hyperparathyroidism.

Trial Registration

ClinicalTrials.gov NCT00995163     

Risk Factors Associated with Recurrent Diarrheal Illnesses among Children in Kabul,Afghanistan: A Prospective Cohort Study

IntroductionChildhood diarrheal illnesses are a major public health problem. In low-income settings data on disease burden and factors associated with diarrheal illnesses are poorly defined, precluding effective prevention programs. This study explores factors associated with recurrent diarrheal illnesses among children in Kabul, Afghanistan.MethodsA cohort of 1–11 month old infants was followed for 18 months from 2007–2009. Data on diarrheal episodes were gathered through active and passive surveillance. Information on child health, socioeconomics, water and sanitation, and hygiene behaviors was collected. Factors associated with recurrent diarrheal illnesses were analyzed using random effects recurrent events regression models.Results3,045 children were enrolled and 2,511 (82%) completed 18-month follow-up. There were 14,998 episodes of diarrheal disease over 4,200 child-years (3.51 episodes/child-year, 95%CI 3.40–3.62). Risk of diarrheal illness during the winter season was 63% lower than the summer season (HR = 0.37, 95%CI 0.35–0.39, P<0.001). Soap for hand washing was available in 72% of households and 11.9% had toilets with septic/canalization. Half of all mothers reported using soap for hand washing. In multivariate analysis diarrheal illness was lower among children born to mothers with post-primary education (aHR = 0.79, 95%CI 0.69–0.91, p = 0.001), from households where maternal hand washing with soap was reported (aHR = 0.83, 95%CI 0.74–0.92, p<0.001) and with improved sanitation facilities (aHR = 0.76, 95%CI 0.63–0.93, p = 0.006). Malnourished children from impoverished households had significantly increased risks for recurrent disease [(aHR = 1.15, 95%CI 1.03–1.29, p = 0.016) and (aHR = 1.20, 95%CI 1.05–1.37, p = 0.006) respectively].ConclusionsMaternal hand washing and improved sanitation facilities were protective, and represent important prevention points among public health endeavors. The discrepancy between soap availability and utilization suggests barriers to access and knowledge, and programs simultaneously addressing these aspects would likely be beneficial. Enhanced maternal education and economic status were protective in this population and these findings support multi-sector interventions to combat illness.

Trial Registration

www.ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00548379","term_id":"NCT00548379"}}NCT00548379 https://www.clinicaltrials.gov/ct2/show/{"type":"clinical-trial","attrs":{"text":"NCT00548379","term_id":"NCT00548379"}}NCT00548379     

Interannual Invariability of Forest Evapotranspiration and Its Consequence to Water Flow Downstream

Although drought in temperate deciduous forests decreases transpiration rates of many species, stand-level transpiration and total evapotranspiration is often reported to exhibit only minor interannual variability with precipitation. This apparent contradiction was investigated using four years of transpiration estimates from sap flux, interception–evaporation estimates from precipitation and throughfall gauges, modeled soil evaporation and drainage estimates, and eddy covariance data in a mature oak-hickory forest in North Carolina, USA. The study period included one severe drought year and one year of well above-average precipitation. Normalized for atmospheric conditions, transpiration rates of some species were lower in drought than in wet periods whereas others did not respond to drought. However, atmospheric conditions during drought periods are unlike conditions during typical growing season periods. The rainy days that are required to maintain drought-free periods are characterized by low atmospheric vapor pressure deficit, leading to very low transpiration. In contrast, days with low air vapor pressure deficit were practically absent during drought and moderate levels of transpiration were maintained throughout despite the drying soil. Thus, integrated over the growing season, canopy transpiration was not reduced by drought. In addition, high vapor pressure deficit during drought periods sustained appreciable soil evaporation rates. As a result, despite the large interannual variation in precipitation (ranging from 934 to 1346 mm), annual evapotranspiration varied little (610–668 mm), increasing only slightly with precipitation, due to increased canopy rainfall interception. Because forest evapotranspiration shows only modest changes with annual precipitation, lower precipitation translates to decreased replenishment of groundwater and outflow, and thus the supply of water to downstream ecosystems and water bodies.     

Large Variations in Risk of Hepatocellular Carcinoma and Mortality in Treatment Na?ve Hepatitis B Patients: Systematic Review with Meta-Analyses

Background

The complications to chronic hepatitis B (HBV) include incidence of hepatocellular carcinoma (HCC) and mortality. The risk of these complications may vary in different patient groups.

Aim

To estimate the incidence and predictors of HCC and in untreated HBV patients.

Methods

Systematic review with random effects meta-analyses of randomized controlled trials and observational studies. Results are expressed as annual incidence (events per 100 person-years) with 95% confidence intervals. Subgroup and sensitivity analyses of patient and study characteristics were performed to identify common risk factors.

Results

We included 68 trials and studies with a total of 27,584 patients (264,919 person-years). In total, 1,285 of 26,687 (5%) patients developed HCC and 730 of 12,511 (6%) patients died. The annual incidence was 0.88 (95% CI, 0.76–0.99) for HCC and 1.26 (95% CI, 1.01–1.51) for mortality. Patients with cirrhosis had a higher risk of HCC (incidence 3.16; 95% CI, 2.58–3.74) than patients without cirrhosis (0.10; 95% CI, 0.02–0.18). The risk of dying was also higher for patients with than patients without cirrhosis (4.89; 95% CI, 3.16–6.63; and 0.11; 95% CI, 0.09–0.14). The risk of developing HCC increased with HCV coinfection, older age and inflammatory activity. The country of origin did not clearly predict HCC or mortality estimates.

Conclusions

Cirrhosis was the strongest predictor of HCC incidence and mortality. Patients with HBV cirrhosis have a 31-fold increased risk of HCC and a 44-fold increased mortality compared to non-cirrhotic patients. The low incidence rates should be taken into account when considering HCC screening in non-cirrhotic patients.

Trial Registration

Prospero CRD42013004764     

Tacrolimus Decreases Albuminuria in Patients with IgA Nephropathy and Normal Blood Pressure: A Double-Blind Randomized Controlled Trial of Efficacy of Tacrolimus on IgA Nephropathy

Background

Treatment remains uncertain for IgA nephropathy patients with mild to moderate proteinuria, for whom anti-hypertensive medication or the RAS blocker is not applicable due to low blood pressure.

Trial design

A double blinded randomized trial.

Methods

The anti-proteinuric effect of tacrolimus was explored for 40 biopsy-proven mild IgA nephropathies for 16 weeks. We randomly assigned patients either to receive tacrolimus or placebo with stratification by using a renin angiotensin system blocker. The primary outcome was the percentage change of final UACR compared to the baseline value (pcUACR).

Results

The mean value of pcUACR at 12-week and 16-week visits (primary outcome) was decreased more in the Tac group compared to the control group (–52.0±26.4 vs –17.3±29.3%, p = 0.001). At each visit, pcUACR was also decreased more in the Tac group compared to the control group. In the Tac group, the pcUACRs were –60.2±28.2%, –62.2±33.9%, –48.5±29.8%, and –55.5±24.0%, and, in the control group, –6.8±32.2%, –2.5±35.9%, –12.7±34.2%, and –21.9±30.6%, at 4-week, 8-week, 12-week, and 16-week visits, respectively. The pre-defined secondary outcomes were better in the Tac group compared to the control group. The frequency of decrease in pcUACR and percentage change of UPCR (pcUPCR) ≥50% at 16 weeks were 65.0% (13/20) and 55.0% (11/20)in the Tac group, and 25.0% (5/20) and 15.0% (3/20), in the control group, respectively (p = 0.025 for pcUACR and p = 0.019 for pcUPCR). However, tacrolimus wasn''t effective with a dose of 0.05 mg/kg/day in patients taking ARB. The adverse events were tolerable.

Conclusion

Tacrolimus effectively reduced proteinuria in IgA nephropathy with normal blood pressure. This suggested that tacrolimus could be an alternative to corticosteroid and RAS blocker for IgA nephropathy patients who cannot endure anti-hypertensive medication.

Trial Registration

Clinicaltrial.gov NCT1224028     

Pharmacokinetics of Novel Plant Cell-Expressed Taliglucerase Alfa in Adult and Pediatric Patients with Gaucher Disease

Taliglucerase alfa is a beta-glucocerebrosidase enzyme replacement therapy approved in the United States, Israel, and other countries for treatment of Type 1 Gaucher disease in adults, and is the first approved plant cell—expressed recombinant protein. In this report, taliglucerase alfa pharmacokinetics were assessed in adult and pediatric patients with Gaucher disease from separate multicenter trials of 30 Units/kg and 60 Units/kg doses infused every 2 weeks. Serial blood samples were obtained from adult patients following single-dose administration on day 1 (n = 26) and multiple doses at week 38 (n = 29), and from pediatric patients following administration of multiple doses of taliglucerase alfa for 10–27 months (n = 10). In both adult and pediatric patients, maximum plasma concentration (C_max), area under the plasma concentration-time curve from time zero to last measureable concentration (AUC_0-t), and from time zero to infinity (AUC_0-∞) were higher after 60 Units/kg dose than 30 Units/kg dose. No tendency for accumulation or change in taliglucerase alfa pharmacokinetic parameters over time from day 1 to week 38 was observed with repeated doses of 30 or 60 Units/kg in adults. After multiple doses, mean (range) dose-normalized pharmacokinetic parameters were similar for adult versus pediatric patients receiving 60 Units/kg: C_max expressed in ng/mL/mg was 42.4 (14.5–95.4) in adults and 46.6 (34.4–68.4) in pediatric patients, AUC_{0 t} expressed in ng•h/mL/mg was 63.4 (26.3–156) in adults and 63.9 (39.8–85.1) in pediatric patients, t_1/2 expressed in minutes was 34.8 (11.3–104) in adults and 31.5 (18.0–42.9) in pediatric patients and total body clearance expressed in L/h was 19.9 (6.25–37.9) in adults and 17.0 (11.7–24.9) in pediatric patients. These pharmacokinetic data extend the findings of taliglucerase alfa in adult and pediatric patients.

Trial Registration

ClinicalTrials.gov. NCT00376168 (in adults); NCT01411228 (in children)     

Losing the beat: deficits in temporal coordination

Tapping or clapping to an auditory beat, an easy task for most individuals, reveals precise temporal synchronization with auditory patterns such as music, even in the presence of temporal fluctuations. Most models of beat-tracking rely on the theoretical concept of pulse: a perceived regular beat generated by an internal oscillation that forms the foundation of entrainment abilities. Although tapping to the beat is a natural sensorimotor activity for most individuals, not everyone can track an auditory beat. Recently, the case of Mathieu was documented (Phillips-Silver et al. 2011 Neuropsychologia 49, 961–969. (doi:10.1016/j.neuropsychologia.2011.02.002)). Mathieu presented himself as having difficulty following a beat and exhibited synchronization failures. We examined beat-tracking in normal control participants, Mathieu, and a second beat-deaf individual, who tapped with an auditory metronome in which unpredictable perturbations were introduced to disrupt entrainment. Both beat-deaf cases exhibited failures in error correction in response to the perturbation task while exhibiting normal spontaneous motor tempi (in the absence of an auditory stimulus), supporting a deficit specific to perception–action coupling. A damped harmonic oscillator model was applied to the temporal adaptation responses; the model''s parameters of relaxation time and endogenous frequency accounted for differences between the beat-deaf cases as well as the control group individuals.     

The Intraocular Pressure under Deep versus Moderate Neuromuscular Blockade during Low-Pressure Robot Assisted Laparoscopic Radical Prostatectomy in a Randomized Trial

Background

This study aimed to determine whether continuous deep neuromuscular blockade (NMB) improves the surgical conditions and facilitates robotic-assisted laparoscopic radical prostatectomy (RALRP) under low intra-abdominal pressure (IAP) to attenuate the increase in intraocular pressure (IOP) during CO₂ pneumoperitoneum in the steep Trendelenburg (ST) position.

Methods

Sixty-seven patients undergoing RALRP were randomly assigned to a moderate NMB group (Group M), including patients who received atracurium infusion until the end of the ST position, maintaining a train of four count of 1–2; and the deep NMB group (Group D), including patients who received rocuronium infusion, maintaining a post-tetanic count of 1–2. IOP was measured in all patients at nine separate time points. All RALRPs were performed by one surgeon, who rated the overall and worst surgical conditions at the end of the ST position.

Results

The highest IOP value was observed at T4 (60 min after the ST position) in both Group M (23.3 ± 2.7 mmHg) and Group D (19.8 ± 2.1 mmHg). RALRP was accomplished at an IAP of 8 mmHg in 88% Group D patients and 25% Group M patients. The overall surgical condition grade was 4.0 (3.0–5.0) in Group D and 3.0 (2.0–5.0) in Group M (P < 0.001).

Conclusion

The current study demonstrated that continuous deep NMB may improve surgical conditions and facilitate RALRP at a low IAP, resulting in significant attenuation of the increase on IOP. Moreover, low-pressure pneumoperitoneum, facilitated by deep NMB still provided acceptable surgical conditions.

Trial Registration

ClinicalTrials.gov NCT02109133