Benthic macroinvertebrates as indicators of water quality: A case study of estuarine ecosystems along the coast of Ghana.

Increasing human activities in coastal areas of Ghana have led to the degradation of many surface waterbodies, with significant consequences for the ecosystems in the affected areas. Thus, this degradation extremely affects the health of ecosystems and disrupts the essential services they provide. The present study explored the use of benthic macroinvertebrates as an indicator of estuarine degradation along the coast of Ghana. Water and sediment samples were collected bimonthly from Ankobra, Kakum and Volta estuaries for physicochemical parameters, nutrients and benthic macroinvertebrates. The findings revealed the dominance of pollution-tolerant taxa such as Capitella sp., Nereis sp., Heteromastus sp., Tubifex sp., Cossura sp. and Chironomous sp. in Kakum Estuary while pollution-sensitive taxa such as Scoloplos sp., Euridice sp., Lumbriconereis sp. and Pachymelania sp. in the Volta Estuary. The species-environment interactions showed dissolved oxygen, temperature, salinity, orthophosphate, nitrates, ammonium, electrical conductivity, turbidity, and chemical oxygen demand as the most significant parameters that complement the use of benthic macroinvertebrates as indicators of environmental quality in the studied estuaries. There were correlations of some benthic macroinvertebrate taxa with environmental factors in the estuaries suggesting low, moderate and high levels of pollution in the Volta, Kakum and Ankobra estuaries, respectively. Nevertheless, the study finds Kakum Estuary to be the ecologically healthiest estuary than the Volta and Ankobra Estuaries. Therefore, the study has shown benthic macroinvertebrates as a key indicator of ecosystem health alterations, and it is recommended that they should be incorporated with other environmental data for pollution monitoring in Ghanaian coastal waters.

The role of L-type amino acid transporter 1 (Slc7a5) during in vitro myogenesis.

Satellite cells are required for muscle regeneration, remodeling, and repair through their activation, proliferation, and differentiation; however, how dietary factors regulate this process remains poorly understood. The L-type amino acid transporter 1 (LAT1) transports amino acids, such as leucine, into mature myofibers, which then stimulate protein synthesis and anabolic signaling. However, whether LAT1 is expressed on myoblasts and is involved in regulating myogenesis is unknown. The aim of this study was to characterize the expressional and functional relevance of LAT1 during different stages of myogenesis and in response to growth and atrophic conditions in vitro. We determined that LAT1 is expressed by C2C12 and human primary myoblasts, and its gene expression is lower during differentiation (P < 0.05). Pharmacological inhibition and genetic knockdown of LAT1 impaired myoblast viability, differentiation, and fusion (all P < 0.05). LAT1 protein content in C2C12 myoblasts was not significantly altered in response to different leucine concentrations in cell culture media or in two in vitro atrophy models. However, LAT1 content was decreased in myotubes under atrophic conditions in vitro (P < 0.05). These findings indicate that LAT1 is stable throughout myogenesis and in response to several in vitro conditions that induce muscle remodeling. Further, amino acid transport through LAT1 is required for normal myogenesis in vitro.

Exercise Improves Cancer-free Survival and Health Span in a Model of Radiation-induced Cancer.

INTRODUCTION: Radiation therapy increases the risk of secondary malignancy and morbidity in cancer survivors. The role of obesity and exercise training in modulating this risk is not well understood. As such, we used a preclinical model of radiation-induced malignancy to investigate whether diet-induced obesity and/or endurance exercise training altered lifelong survival, cancer incidence, and morbidity. METHODS: Male CBA mice were randomly divided into control diet/sedentary group (CTRL/SED), high-fat diet (45% fat)/sedentary group (HFD/SED), control diet/exercise group (2-3 d·wk-1; CTRL/EX), or high-fat diet/exercise group (HFD/EX) groups then exposed to whole-body radiation (3 Gy). End point monitoring and pathology determined mortality and cancer incidence, respectively. Health span index, a measure of morbidity, was determined by a composite measure of 10 anthropometric, metabolic, performance, and behavioral measures. RESULTS: Overall survival was higher in HFD/SED compared with CTRL/SED (P < 0.05). The risk of cancer-related mortality by 18 months postradiation was 1.99 and 1.63 in HFD/SED compared with CTRL/EX (RR = 1.99, 95% confidence interval = 1.20-3.31, P = 0.0081) and CTRL/SED (RR = 1.63, 95% confidence interval = 1.06-2.49, P = 0.0250), respectively. The number of mice at end point with cancer was higher in HFD/SED compared with CTRL/EX and CTRL/SED (P < 0.05). Health span index was highest in CTRL/EX (score = +2.5), followed by HFD/EX (score = +1), and HFD/SED (score = -1) relative to CTRL/SED. CONCLUSION: This work provides the basis for future preclinical studies investigating the dose-response relationship between exercise training and late effects of radiation therapy as well as the mechanisms responsible for these effects.

1H-NMR Determination of Organic Compounds in Municipal Wastewaters and the Receiving Surface Waters in Eastern Cape Province of South Africa.

Surface water is the recipient of pollutants from various sources, including improperly treated wastewater. Comprehensive knowledge of the composition of water is necessary to make it reusable in water-scarce environments. In this work, proton nuclear magnetic resonance (1H-NMR) was combined with multivariate analysis to study the metabolites in four rivers and four wastewater treatment plants releasing treated effluents into the rivers. 1H-NMR chemical shifts of the extracts in CDCl were acquired with Bruker 400. Chemical shifts of 1H-NMR in chlorinated alkanes, amino compounds and fluorinated hydrocarbons were common to samples of wastewater and lower reaches or the rivers. 1H-NMR chemical shifts of carbonyl compounds and alkyl phosphates were restricted to wastewater samples. Chemical shifts of phenolic compounds were associated with treated effluent samples. This study showed that the sources of these metabolites in the rivers were not only from improperly treated effluents but also from runoffs. Multivariate analyses showed that some of the freshwater samples were not of better quality than wastewater and treated effluents. Observations show the need for constant monitoring of rivers and effluent for the safety of the aquatic environment.

Evaluating the responses of taxa in the orders Ephemeroptera, Plecoptera and Trichoptera (EPT) to sediment stress in the Tsitsa River and its tributaries, Eastern Cape, South Africa.

Excessive delivery of fine sediment has been implicated as the main water quality stressor in the Tsitsa River catchment. This study evaluates the responses of the taxa Ephemeroptera, Plecoptera and Trichoptera (EPT) to suspended sediment and grain size distribution in eight selected study sites in the Tsitsa River catchment. The sampling of macroinvertebrates took place seasonally from August 2016 to April 2017 and EPT identified to either genus or species level. To avoid site redundancy, the sites were clustered into four groups, with groups 1 and 2 being more impacted when compared to groups 3 and 4. The results of the sediment grain size analysis revealed that sediment grain size distribution ranged from 0.121 to 5.61 µm; percent clay and percent silt were the most dominant sediment fractions across all groups. Among the EPT metrics examined, Shannon index, Simpson's index, evenness, Ephemeroptera abundance, EPT abundance and Trichoptera abundance were sensitive, differentiating between sediment groups 3 and 4 (less impacted groups) from 1 and 2 (highly impacted groups). Site groups 3 and 4 supported more EPT species, in terms of the number of individuals and diversity. Species such as Caenis sp., Pseudocloeon glaucum, Oligoneuropsis lawrencei and Baetis sp. were considered sediment-tolerant, displaying strong positive association with influenced groups. Taxa such as Hydropsyche sp., Pseudocloeon sp., Cheumatopsyche sp. and Afronurus sp. were considered sediment-sensitive. Overall, the present study revealed that genera/species within the order EPT were differentially sensitive to fine sediment stress and grain sizes, proving to be useful bioindicators.

Development of a procedure for determining the mixing ratios in ecotoxicological experiments and its application in binary salt mixture experiments.

Although a plethora of models exist to describe the characteristics and risk assessment of chemical mixtures in ecotoxicology, there is no specific procedure to decide on the mixing ratios (i.e. proportions of the individual chemical substances that form the mixture) at any desired level of concentration in an ecotoxicological mixture experiment. In this study, an attempt was made to develop a procedure for determining the mixing ratios in ecotoxicological experiments. In brief, from a single salt exposure test, the relative toxic fractions, which represent the toxic effect exerted by the individual salts, are determined. Thereafter, the proportions of each individual salt at any level of concentration in the mixture are estimated by multiplying the desired concentration with the relative toxic fraction of that particular salt. The procedure was applied to ecotoxicological experiments involving four binary salt mixtures (MgCl2 + MgSO4, NaCl + Na2SO4, MgCl2 + Na2SO4 and NaCl + MgSO4) and Caridina nilotica, an indigenous South African freshwater shrimp. It is hoped that the application of this developed procedure will ensure administering the correct proportions of individual chemical substances in chemical mixtures in order to obtain the desired levels of concentration in aquatic ecotoxicological mixture experiments.

Derivation of South African water quality guidelines for Roundup(®) using species sensitivity distribution.

Glyphosate-based herbicides are among the leading products used in South Africa to control weeds and invading alien plant species. Although these herbicides ultimately find their way into aquatic ecosystems, South Africa has no water quality guideline based on indigenous species to protect the country's aquatic biota against these biocides. In this study, South African water quality guidelines (SAWQGs) for Roundup(®) based on species sensitivity distribution (SSD) using indigenous aquatic biota were developed. Short-term and long-term toxicity tests were conducted with eight different aquatic species belonging to five different taxonomic groups. Static non-renewal experimental methods were employed for short-term lethal tests (≤4 days), and static renewal for long-term sublethal tests (≥4 days ≤21 days). LC50 values for animal exposure and EC50 values for algae were calculated using probit analysis and linear regression of transformed herbicide concentration as natural logarithm data against percentage growth inhibition, respectively. No effect concentration (NEC) was determined based on the dynamic energy budget model, using survival data. The LC50, EC50 and NEC values were used to develop species sensitivity distribution (SSD) concentrations for Roundup(®). Based on the SSD concentrations, the short-term and long-term SAWQGs for Roundup(®) were derived as 0.250 (0.106-0.589) mg/L, and 0.002 (0.000-0.021) mg/L, respectively. These WQGs may be useful in protecting South African aquatic life against transient or long-term exposure to glyphosate-based chemicals as part of integrated water resources management.

Chronic myeloid leukemia in an adult ghanaian with sporadic neurofibromatosis 1.

Patients with neurofibromatosis type 1 (NF1), a common, progressive, autosomal dominant neurocutaneous disorder, are predisposed to malignancies. Several types of hematologic malignancies have been described in them. However, to date there has been no report to the best of our knowledge of a patient with NF1 developing chronic myeloid leukemia (CML). We present an adult Ghanaian with NF1, who subsequently developed CML. Relevance of the case report is discussed.

Binding and elution behavior of proteins on strong cation exchangers.

This work provides a broad survey of binding and elution behavior of proteins on strong cation exchangers. Four proteins comprising two monoclonal antibodies, lysozyme, and cytochrome c were used as models in the investigation. Seven chromatography resins with different base matrices were compared. Dynamic binding capacity as a function of salt concentration was examined for a monoclonal antibody and lysozyme. Elution behavior as a function of gradient slope was modeled to determine the characteristic charge, essentially a measure of the number of sites involved in binding, for each protein on each resin. Trends with respect to dynamic binding capacity and elution behavior are analyzed and discussed.

Comparison of agarose and dextran-grafted agarose strong ion exchangers for the separation of protein aggregates.

The control of aggregate levels in recombinant protein based drugs is a primary concern during process development and manufacture. In recent years, a novel class of dextran-grafted ion exchange matrices has gained popularity for process scale protein purification due to increased mass transfer rates and higher dynamic binding capacity compared to conventional matrices. Using bovine serum albumin and a monoclonal antibody as model proteins, we studied Sepharose FF and Sepharose XL ion exchangers for the separation of protein aggregates. Experimental results comparing linear gradient elution, stepwise elution, and flow-through chromatography for aggregate separation are described. Differences in performance for the various ion exchangers are discussed and modeled. Strategies for the optimization of protein aggregate separation are provided.

Separation of protein charge variants with induced pH gradients using anion exchange chromatographic columns.

This work concerns the chromatographic separation of protein charge variants using pH gradients generated by step changes in buffer composition with weak base anion exchange columns. A local equilibrium model is first developed to describe pH transitions occurring in the column using buffers comprising neutral, zwitterionic or positively charged species. Model predictions, based solely on the resins' titration curves and obtained with the method of characteristics, show, in excellent agreement with experiments, that induced pH gradients of varying durations and shapes can be obtained with a broad range of buffer systems including Tris, Bis-Tris propane, histidine, and their mixtures and ethanolamine. The separation of protein charge variants is then demonstrated for bovine apo-transferrin and for a monoclonal antibody. The resolution of the charge variants present in these proteins, demonstrated via isoelectric focusing analyses, is obtained for conditions amenable to scale-up for preparative purposes; that is larger particle sizes (90 mum), higher flow rates (100-600 cm/h), and higher protein loads (2-5 mg/mL). Because the approach requires only step changes in buffer composition and commonly available, unretained buffers species, practical implementation is straightforward. The focusing effect of the induced pH gradient results in relatively sharp peaks and substantial resolution even for these conditions.