scholarly journals Temporal and spatial variability of cyanobacterial toxins microcystins in three interconnected freshwater reservoirs

2010 ◽  
Vol 75 (9) ◽  
pp. 1303-1312 ◽  
Author(s):  
Luděk Bláha ◽  
Lucie Bláhová ◽  
Jiří Kohoutek ◽  
Ondřej Adamovský ◽  
Pavel Babica ◽  
...  
Keyword(s):  
Dry Weight ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Cyanobacterial Toxins ◽  
Toxic Cyanobacteria ◽  
Guideline Value ◽  
High Concentrations ◽  
Health Organization ◽  
Reported Data ◽  
Natural Dynamics

In spite of substantial research on health and the ecological risks associated with cyanobacterial toxins in the past decades, the understanding of the natural dynamics and variability of toxic cyanobacterial blooms is still limited. Herein, the results of long term monitoring 1998-1999 / 2001-2008 of three reservoirs (V?r, Brno and Nov? Ml?ny), where toxic blooms develop annually, are reported. These three reservoirs provide a unique model because they are interconnected by the Svratka River, which allows possible transfer of phytoplankton as well as toxins from one reservoir to another. The frequency of the occurrence and dominance of the major cyanobacterial taxa Microcystis aeruginosa did not change during the investigated period but substantial variability was observed in the composition of other phytoplankton. Although absolute concentrations of the studied toxins (microcystins) differed among the reservoirs, there were apparent parallel trends. For example, during certain years, the microcystin concentrations were systematically elevated in all three studied reservoirs. Furthermore, the concentration profiles in the three sites were also correlated (parallel trends) within individual seasons based on monthly sampling. Microcystin-LR, a variant for which the World Health Organization has recommended a guideline value, formed only about 30-50% of the total microcystins. This is of importance, especially in the V?r reservoir that serves as a drinking water supply. Maxima in the cell-bound microcystins (intracellular; expressed per dry weight biomass) generally preceded the maxima of total microcystins (expressed per volume of water sample). Overall, the maximum concentration in the biomass (all three reservoirs, period 1993-2005) was 6.1 mg g-1 dry weight and the median values were in the range 0.065-2.3 mg g-1 dry weight. These are generally high concentrations in comparison with both Czech Republic and worldwide reported data. The present data revealed substantial variability of both toxic cyanobacteria and their peptide toxins that should be reflected by detailed monitoring programs.

scholarly journals Noncompetitive Chromogenic Lateral-Flow Immunoassay for Simultaneous Detection of Microcystins and Nodularin

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 79 ◽  
Author(s):  
Sultana Akter ◽  
Teemu Kustila ◽  
Janne Leivo ◽  
Gangatharan Muralitharan ◽  
Markus Vehniäinen ◽  
...  
Keyword(s):  
Water Quality ◽  
Simultaneous Detection ◽  
Antibody Fragment ◽  
Water Quality Monitoring ◽  
Lateral Flow ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Lateral Flow Immunoassay ◽  
Guideline Value ◽  
Health Organization

Cyanobacterial blooms cause local and global health issues by contaminating surface waters. Microcystins and nodularins are cyclic cyanobacterial peptide toxins comprising numerous natural variants. Most of them are potent hepatotoxins, tumor promoters, and at least microcystin-LR is possibly carcinogenic. In drinking water, the World Health Organization (WHO) recommended the provisional guideline value of 1 µg/L for microcystin-LR. For water used for recreational activity, the guidance values for microcystin concentration varies mostly between 4–25 µg/L in different countries. Current immunoassays or lateral flow strips for microcystin/nodularin are based on indirect competitive method, which are generally more prone to sample interference and sometimes hard to interpret compared to two-site immunoassays. Simple, sensitive, and easy to interpret user-friendly methods for first line screening of microcystin/nodularin near water sources are needed for assessment of water quality and safety. We describe the development of a two-site sandwich format lateral-flow assay for the rapid detection of microcystins and nodularin-R. A unique antibody fragment capable of broadly recognizing immunocomplexes consisting of a capture antibody bound to microcystins/nodularin-R was used to develop the simple lateral flow immunoassay. The assay can visually detect the major hepatotoxins (microcystin-LR, -dmLR, -RR, -dmRR, -YR, -LY, -LF -LW, and nodularin-R) at and below the concentration of 4 µg/L. The signal is directly proportional to the concentration of the respective toxin, and the use of alkaline phosphatase activity offers a cost efficient alternative by eliminating the need of toxin conjugates or other labeling system. The easy to interpret assay has the potential to serve as a microcystins/nodularin screening tool for those involved in water quality monitoring such as municipal authorities, researchers, as well as general public concerned of bathing water quality.

scholarly journals A Summer of Cyanobacterial Blooms in Belgian Waterbodies: Microcystin Quantification and Molecular Characterizations

Toxins ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 61
Author(s):  
Wannes Hugo R. Van Hassel ◽  
Mirjana Andjelkovic ◽  
Benoit Durieu ◽  
Viviana Almanza Marroquin ◽  
Julien Masquelier ◽  
...  
Keyword(s):  
Water Samples ◽  
Direct Sequencing ◽  
Amplicon Sequencing ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Limit Of Quantification ◽  
Guideline Value ◽  
16S Rna ◽  
Mcye Gene ◽  
Health Organization

In the context of increasing occurrences of toxic cyanobacterial blooms worldwide, their monitoring in Belgium is currently performed by regional environmental agencies (in two of three regions) using different protocols and is restricted to some selected recreational ponds and lakes. Therefore, a global assessment based on the comparison of existing datasets is not possible. For this study, 79 water samples from a monitoring of five lakes in Wallonia and occasional blooms in Flanders and Brussels, including a canal, were analyzed. A Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) method allowed to detect and quantify eight microcystin congeners. The mcyE gene was detected using PCR, while dominant cyanobacterial species were identified using 16S RNA amplification and direct sequencing. The cyanobacterial diversity for two water samples was characterized with amplicon sequencing. Microcystins were detected above limit of quantification (LOQ) in 68 water samples, and the World Health Organization (WHO) recommended guideline value for microcystins in recreational water (24 µg L−1) was surpassed in 18 samples. The microcystin concentrations ranged from 0.11 µg L−1 to 2798.81 µg L−1 total microcystin. For 45 samples, the dominance of the genera Microcystis sp., Dolichospermum sp., Aphanizomenon sp., Cyanobium/Synechococcus sp., Planktothrix sp., Romeria sp., Cyanodictyon sp., and Phormidium sp. was shown. Moreover, the mcyE gene was detected in 75.71% of all the water samples.

Immunogenicity and Safety of the Measles Vaccine in HIV-Infected Children: An Updated Systematic Review

2019 ◽  
Author(s):  
Nicky J Mehtani ◽  
Lori Rosman ◽  
William J Moss
Keyword(s):  
Latin American ◽  
Prevalence Ratio ◽  
Vaccine Safety ◽  
World Health ◽  
Measles Vaccine ◽  
Serious Adverse Events ◽  
Increased Risk ◽  
Hiv Exposed ◽  
Health Organization ◽  
Reported Data

Abstract Children infected with human immunodeficiency virus (HIV) are at increased risk of measles morbidity and mortality. We searched abstracts from the PubMed, Embase, and Latin American and Caribbean Center on Health Sciences Information databases for articles published from the earliest date available through September 26, 2017. The primary outcome of interest was serological responses to measles vaccine, stratified by HIV infection status. A total of 2,858 potentially eligible articles were identified, and the final review included 12 studies published between 1992 and 2013, 9 of which reported data on vaccine safety. The studies we included represented 3,573 children, of whom at least 335 were infected with HIV, 788 were HIV-exposed but not infected, and 1,478 were unexposed to HIV. Four of the 12 studies found statistically significant reductions in seropositivity among HIV-infected children compared with HIV-uninfected children within 4 months of vaccination (prevalence ratio range, 0.44–0.70), and forest plots provided visual trends of decreasing immunity over time among HIV-infected children in 2 additional studies. No vaccine-related deaths or serious adverse events were reported. This updated review demonstrated limitations of the existing published literature but supported evidence of reduced immunogenicity of measles vaccine among HIV-infected children, supporting the World Health Organization recommendation to revaccinate HIV-infected children against measles following immune reconstitution with combination antiretroviral therapy.

scholarly journals Total mercury in the night shark, Carcharhinus signatus in the western equatorial Atlantic Ocean

2004 ◽  
Vol 47 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Alexandre Gomes Ferreira ◽  
Vicente Vieira Faria ◽  
Carlos Euardo Veiga de Carvalho ◽  
Rosangela Paula Teixeira Lessa ◽  
Francisco Marcante Santana da Silva
Keyword(s):  
Atlantic Ocean ◽  
Total Mercury ◽  
Atomic Emission ◽  
World Health ◽  
Human Consumption ◽  
Equatorial Atlantic ◽  
Daily Ingestion ◽  
Equatorial Atlantic Ocean ◽  
High Concentrations ◽  
Health Organization

Mercury is the only element capable to biomagnificate along the food chain, and carnivorous fish tend to accumulate high concentrations of this element. Total mercury in muscle tissue of Carcharhinus signatus sampled along the western equatorial Atlantic Ocean was measured by atomic emission spectrophotometry with ICP/AES. The average total mercury concentrations were consistently greater than the maximum limit for human consumption established by the Brazilian Health Ministry for carnivorous fishes (1000 µg. kg-1 w.w.). Therefore, an average consumption of 0.1 kg/day of C. signatus would result in an average daily ingestion of 174.2 µg of Hg, more than five times the 30 µg/day intake established by the World Health Organization. In the range of lengths studied, body length could not be used as an indicator of the Hg contamination degree for C. signatus. Also, sex cannot be considered a determining factor in the total mercury accumulation in C. signatus.

scholarly journals Reevaluation of the University of Wisconsin 2-Year Protocol for Treating Canine Lymphosarcoma

2007 ◽  
Vol 43 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Claire Inderbinen Kaiser ◽  
Janean L. Fidel ◽  
Malgorzata Roos ◽  
Barbara Kaser-Hotz
Keyword(s):  
Stage Iv ◽  
World Health ◽  
Treatment Delays ◽  
Prior Therapy ◽  
University Of Wisconsin ◽  
Chemotherapy Protocol ◽  
First Remission ◽  
Health Organization ◽  
Reported Data ◽  
The University

This retrospective study investigated a population of 96 dogs with newly diagnosed malignant lymphosarcoma that were treated with the commonly used University of Wisconsin-Madison (UW-M) chemotherapy protocol. Pretreatment characteristics were analyzed to determine prognostic factors. Dogs with higher World Health Organization (WHO) stages (including stage IV) and dogs with hypercalcemia were at significantly higher risk of relapse (P=0.018 and P=0.016, respectively). Dose reduction, treatment delays, and prior therapy with cortico-steroids were not associated with clinical outcome. First remission duration of 270 days was similar to historically reported data. Overall survival time of 218 days was much shorter than historical data.

Characteristics, distribution and sources of polychlorinated biphenyls (PCBs) in coastal sediments from the heavily industrialized area of Asalouyeh, Iran

2017 ◽  
Vol 76 (12) ◽  
pp. 3340-3350 ◽  
Author(s):  
Hossein Arfaeinia ◽  
Zahra Asadgol ◽  
Ehsan Ahmadi ◽  
Morteza Seifi ◽  
Masoud Moradi ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Persian Gulf ◽  
Dry Weight ◽  
Coastal Sediments ◽  
World Health ◽  
Multivariate Statistical ◽  
Contamination Levels ◽  
Toxic Equivalents ◽  
The Persian Gulf ◽  
Health Organization

Abstract In this research, the levels of polychlorinated biphenyls (PCBs) were investigated in the marine sediments of Asaluyeh harbor, in the Persian Gulf. The samples were taken from industrial, semi-industrial and urban regions. The mean concentration levels of total (Σ) 18 detected PCBs were 514.32, 144.67 and 31.6 pg/g dw for the industrial, semi-industrial and urban sampling stations, respectively. Based on a multivariate statistical analysis, it was found that high contamination levels of PCBs in sediments collected along the Persian Gulf were associated with releases from local industries. Total organic carbon (TOC) content was significantly and positively correlated with the concentrations of PCB congeners. World Health Organization toxic equivalents (TEQs) for PCBs ranged from 0.04 to 2.66 pg TEQ/g dry weight (dw) in the coastal sediments. The TEQ values in this study were higher than many reported worldwide in the literature for sediments. This suggests that there are high levels of contamination in the area due to industrial and other human activities.

scholarly journals Groundwater Quality Assessment of Abandoned Dumpsite in Osogbo Suburb, Nigeria: Hydrogeological and Geophysical Condition Six Years after Initial Study

2021 ◽  
Vol 25 (7) ◽  
pp. 1213-1219
Author(s):  
A.O. Ojo ◽  
A.C. Oyelami ◽  
E.M. Babafemi
Keyword(s):  
Ground Penetrating Radar ◽  
Chemical Constituents ◽  
Quality Standard ◽  
Initial Study ◽  
Unconfined Aquifer ◽  
World Health ◽  
Geophysical Investigation ◽  
High Concentrations ◽  
Health Organization ◽  
Ground Penetrating

In this paper, we describe the result of a recent hydrogeological and geophysical investigation carried out within and around Aduramigba - Onibu-Eja Estate dumpsite with the aim of detecting evidence of contamination as well as depths to contamination of the groundwater after a previous study six years ago. Twenty water samples from shallow water wells and boreholes were analyzed for their physico-chemical constituents while five vertical electrical soundings and five electromagnetic ground penetrating radar surveys were conducted. The result shows high concentrations of anions of nitrates (NO3-), bicarbonates (HCO3-), chloride (Cl-) and sulphate (SO42-) with values of 73.97 mg/l, 91.5 mg/l, 331.2 mg/l, 222.4 mg/l respectively, cations values of Mg2+, Fe2+, Na+, and K+ having value of 25.44 mg/l, 6.23 mg/l, 37.31 mg/l and 35.41 mg/l, respectively, which were far above the World Health Organization (WHO) and Nigeria Drinking Water Quality Standard (NDWS). Heavy metal components such as Lead, Zinc, Copper and Nickel were also observed to be on the high side, having been contributed from effluents from rust metallic materials cum chemicals dumped within the dumpsite. Detailed geophysical study reveal the depth to contamination at between 4.1 meters in VES 3 to 5.9 meters in VES 2 with resistivity as low as 5.12 Ωm in VES 2 to 7.12 Ωm in VES 3 while ground penetrating radar (GPR) revealed that the leachate has permeated to a depth of 3.5 – 5.25 meters in traverse 4 and 4.0 – 6.0 meters in traverse 3 which correspond to the depth to unconfined aquifer within the dumpsite. The study conclude that this would pose a greater threat to residents living in this vicinity and as such, this might have contributed to the closure of the dumpsite.

scholarly journals A Report on COVID-19 Epidemic in Pakistan: An SEIR Fractional Model

2020 ◽  
Author(s):  
Zubair Ahmad ◽  
Muhammad Arif ◽  
Farhad Ali ◽  
Ilyas Khan ◽  
Kottakkaran Sooppy
Keyword(s):  
Negative Impact ◽  
World Health ◽  
Fractional Model ◽  
First Case ◽  
Global Issue ◽  
Novel Coronavirus ◽  
Health Organization ◽  
Reported Data ◽  
The Mathematical Model ◽  
The Given

Abstract Recently, novel coronavirus is a serious global issue and having a negative impact on the economy of the whole world. Like other countries, it also effected the economy and people of Pakistan. According to the publicly reported data, the first case of novel corona virus in Pakistan was reported on 27th February 2020. The aim of the present study is to describe the mathematical model and dynamics of COVID-19 in Pakistan. To investigate the spread of coronavirus in Pakistan, we develop the SEIR time fractional model with newly, developed fractional operator of Atangana-Baleanu. We present briefly the analysis of the given model and discuss its applications using world health organization (WHO) reported data for Pakistan. We consider the available infection cases from 19th march 2020, till 31st march 2020 and accordingly, various parameters are fitted or estimated. It is worth noting that we have calculated the basic reproduction number which shows that virus is spreading rapidly. Furthermore, stability analysis of the model at disease free equilibrium DFE and endemic equilibriums EE is performed to observe the dynamics and transmission of the model. Finally, the AB fractional model is solved numerically. To show the effect of the various embedded parameters like fractional parameter on the model, various graphs are plotted. It is worth noting that the base of our investigation, we have predicted the spread of disease for next 200 days.

scholarly journals Dynamics of sputum conversion during effective tuberculosis treatment: A systematic review and meta-analysis

PLoS Medicine ◽  
2021 ◽  
Vol 18 (4) ◽  
pp. e1003566
Author(s):  
Claire J. Calderwood ◽  
James P. Wilson ◽  
Katherine L. Fielding ◽  
Rebecca C. Harris ◽  
Aaron S. Karat ◽  
...  
Keyword(s):  
Systematic Review ◽  
Data Extraction ◽  
Meta Analysis ◽  
World Health ◽  
Significant Heterogeneity ◽  
Tb Treatment ◽  
Health Organization ◽  
Reported Data ◽  
Meta Analyses ◽  
Culture Conversion

Background Two weeks’ isolation is widely recommended for people commencing treatment for pulmonary tuberculosis (TB). The evidence that this corresponds to clearance of potentially infectious tuberculous mycobacteria in sputum is not well established. This World Health Organization–commissioned review investigated sputum sterilisation dynamics during TB treatment. Methods and findings For the main analysis, 2 systematic literature searches of OvidSP MEDLINE, Embase, and Global Health, and EBSCO CINAHL Plus were conducted to identify studies with data on TB infectiousness (all studies to search date, 1 December 2017) and all randomised controlled trials (RCTs) for drug-susceptible TB (from 1 January 1990 to search date, 20 February 2018). Included articles reported on patients receiving effective treatment for culture-confirmed drug-susceptible pulmonary TB. The outcome of interest was sputum bacteriological conversion: the proportion of patients having converted by a defined time point or a summary measure of time to conversion, assessed by smear or culture. Any study design where more than 10 participants were included was considered. Record sifting and data extraction were performed in duplicate. Random effects meta-analyses were performed. A narrative summary additionally describes the results of a systematic search for data evaluating infectiousness from humans to experimental animals (PubMed, all studies to 27 March 2018). Other evidence on duration of infectiousness—including studies reporting on cough dynamics, human tuberculin skin test conversion, or early bactericidal activity of TB treatments—was outside the scope of this review. The literature search was repeated on 22 November 2020, at the request of the editors, to identify studies published after the previous censor date. Four small studies reporting 3 different outcome measures were identified, which included no data that would alter the findings of the review; they are not included in the meta-analyses. Of 5,290 identified records, 44 were included. Twenty-seven (61%) were RCTs and 17 (39%) were cohort studies. Thirteen studies (30%) reported data from Africa, 12 (27%) from Asia, 6 (14%) from South America, 5 (11%) from North America, and 4 (9%) from Europe. Four studies reported data from multiple continents. Summary estimates suggested smear conversion in 9% of patients at 2 weeks (95% CI 3%–24%, 1 single study [N = 1]), and 82% of patients at 2 months of treatment (95% CI 78%–86%, N = 10). Among baseline smear-positive patients, solid culture conversion occurred by 2 weeks in 5% (95% CI 0%–14%, N = 2), increasing to 88% at 2 months (95% CI 84%–92%, N = 20). At equivalent time points, liquid culture conversion was achieved in 3% (95% CI 1%–16%, N = 1) and 59% (95% CI 47%–70%, N = 8). Significant heterogeneity was observed. Further interrogation of the data to explain this heterogeneity was limited by the lack of disaggregation of results, including by factors such as HIV status, baseline smear status, and the presence or absence of lung cavitation. Conclusions This systematic review found that most patients remained culture positive at 2 weeks of TB treatment, challenging the view that individuals are not infectious after this interval. Culture positivity is, however, only 1 component of infectiousness, with reduced cough frequency and aerosol generation after TB treatment initiation likely to also be important. Studies that integrate our findings with data on cough dynamics could provide a more complete perspective on potential transmission of Mycobacterium tuberculosis by individuals on treatment. Trial registration Systematic review registration: PROSPERO 85226.

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