Characterization of the Nairobi River catchment impact zone and occurrence of pharmaceuticals: implications for an impact zone inclusive environmental risk assessment

The largely uncontrolled release of active pharmaceuticals ingredients (APIs) within untreated wastewater discharged to waterbodies, associated with many rapidly urbanising centres is of growing concern owing to potential antimicrobial resistance, endocrine disruption and potential toxicity. A sampling campaign has been undertaken to assess the source, occurrence, magnitude and risk associated with APIs and other chemicals within the Nairobi/Athi river basin, in Kenya, East Africa. The catchment showed an extensive downstream impact zone estimated to extend 75 km, mostly, but not exclusively, derived from the direct discharge of untreated wastewater from the urban centre of Nairobi city. The exact extent of the downstream boundary of the Nairobi city impact zone was unclear owing to the inputs of untreated wastewater sources from the continuous urbanized areas along the river, which counteracted the natural attenuation caused by dilution and degradation. The most frequently detected APIs and chemicals were caffeine, carbamazepine, trimethoprim, nicotine, and sulfamethoxazole. Paracetamol, caffeine, sulfamethoxazole, and trimethoprim alone contributed 86% of the total amount of APIs determined along the Nairobi/Athi catchment. In addition to direct discharge of untreated domestic wastewater attributed to the informal settlements within the conurbation, other sources were linked to the industrial area in Nairobi City where drug formulation is known to occur, the Dandora landfill and veterinary medicines from upstream agriculture. It was shown that there was a possible environmental risk of API ecotoxicological effects beyond the end of the traditional impact zone defined by elevated biochemical oxygen demand concentrations; with metronidazole and sulfamethoxazole exhibiting the highest risk

Tissue-specific immunopathology in fatal COVID-19

Funding: Inflammation in COVID-19: Exploration of Critical Aspects of Pathogenesis (ICECAP) receives funding and support from the Chief Scientist Office (RapidResearch in COVID-19 programme [RARC-19] funding call, “Inflammation in Covid-19: Exploration of Critical Aspects of Pathogenesis; COV/EDI/20/10” to D.A.D., C.D.L., C.D.R., J.K.B., and D.J.H.), LifeArc (through the University of Edinburgh STOPCOVID funding award to K.D., D.A.D., and C.D.L.), UK Research and Innovation (UKRI) (Coronavirus Disease [COVID-19] Rapid Response Initiative; MR/V028790/1 to C.D.L., D.A.D., and J.A.H.), and Medical Research Scotland (CVG-1722-2020 to D.A.D., C.D.L., C.D.R., J.K.B., and D.J.H.). C.D.L. is funded by a Wellcome Trust Clinical Career Development Fellowship(206566/Z/17/Z). J.K.B. and C.D.R. are supported by the Medical Research Council (grant MC_PC_19059) as part of the International Severe AcuteRespiratory Infection Consortium Coronavirus Clinical Characterisation Consortium (ISARIC-4C). D.J.H., I.H.U., and M.E. are supported by the Industrial Centre for Artificial Intelligence Research in Digital Diagnostics. S.P. is supported by Kidney Research UK, and G.T. is supported by the Melville Trust for the Cure and Care of Cancer. Identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and sequencing work was supported by theU.S. Food and Drug Administration grant HHSF223201510104C (“Ebola Virus Disease: correlates of protection, determinants of outcome and clinicalmanagement”; amended to incorporate urgent COVID-19 studies) and contract 75F40120C00085 (“Characterization of severe coronavirus infection inhumans and model systems for medical countermeasure development and evaluation”; awarded to J.A.H.). J.A.H. is also funded by the Centre of Excellence in Infectious Diseases Research and the Alder Hey Charity. R.P.-R. is directly supported by the Medical Research Council Discovery Medicine North Doctoral Training Partnership. The group of J.A.H. is supported by the National Institute for Health Research Health Protection Research Unit in Emerging and Zoonotic Infections at the University of Liverpool in partnership with Public Health England and in collaboration with Liverpool School of Tropical Medicine and the University of Oxford.Rationale: In life-threatening Covid-19, corticosteroids reduce mortality, suggesting that immune responses have a causal role in death. Whether this deleterious inflammation is primarily a direct reaction to the presence of SARS-CoV-2 or an independent immunopathologic process is unknown. Objectives: To determine SARS-CoV-2 organotropism and organ-specific inflammatory responses, and the relationships between viral presence, inflammation, and organ injury. Methods: Tissue was acquired from eleven detailed post-mortem examinations. SARS-CoV-2 organotropism was mapped by multiplex PCR and sequencing, with cellular resolution achieved by in situ viral spike protein detection. Histological evidence of inflammation was quantified from 37 anatomical sites, and the pulmonary immune response characterized by multiplex immunofluorescence. Measurements and main results: Multiple aberrant immune responses in fatal Covid-19 were found, principally involving the lung and reticuloendothelial system, and these were not clearly topologically associated with the virus. Inflammation and organ dysfunction did not map to the tissue and cellular distribution of SARS-CoV-2 RNA and protein, both between and within tissues. An arteritis was identified in the lung, which was further characterised as a monocyte/myeloid-rich vasculitis, and occurred along with an influx of macrophage/monocyte-lineage cells into the pulmonary parenchyma. In addition, stereotyped abnormal reticulo-endothelial responses, including excessive reactive plasmacytosis and iron-laden macrophages, were present and dissociated from viral presence in lymphoid tissues. Conclusions: Tissue-specific immunopathology occurs in Covid-19, implicating a significant component of immune-mediated, virus-independent immunopathology as a primary mechanism in severe disease. Our data highlight novel immunopathological mechanisms, and validate ongoing and future efforts to therapeutically target aberrant macrophage and plasma cell responses as well as promoting pathogen tolerance in Covid-19.Publisher PDFPeer reviewe

Characterization of the fine specificity of bovine CD8 T-cell responses to defined antigens from the protozoan parasite Theileria parva

Immunity against the bovine intracellular protozoan parasite Theileria parva has been shown to be mediated by CD8 T cells. Six antigens targeted by CD8 T cells from T. parva-immune cattle of different major histocompatibility complex (MHC) genotypes have been identified, raising the prospect of developing a subunit vaccine. To facilitate further dissection of the specificity of protective CD8 T-cell responses and to assist in the assessment of responses to vaccination, we set out to identify the epitopes recognized in these T. parva antigens and their MHC restriction elements. Nine epitopes in six T. parva antigens, together with their respective MHC restriction elements, were successfully identified. Five of the cytotoxic-T-lymphocyte epitopes were found to be restricted by products of previously described alleles, and four were restricted by four novel restriction elements. Analyses of CD8 T-cell responses to five of the epitopes in groups of cattle carrying the defined restriction elements and immunized with live parasites demonstrated that, with one exception, the epitopes were consistently recognized by animals of the respective genotypes. The analysis of responses was extended to animals immunized with multiple antigens delivered in separate vaccine constructs. Specific CD8 T-cell responses were detected in 19 of 24 immunized cattle. All responder cattle mounted responses specific for antigens for which they carried an identified restriction element. By contrast, only 8 of 19 responder cattle displayed a response to antigens for which they did not carry an identified restriction element. These data demonstrate that the identified antigens are inherently dominant in animals with the corresponding MHC genotypes

The influence of Team-based learning on Entrepreneurial Self-efficacy of University students

A paper presentation at the 3rd East African Multidisciplinary Research Conference (EAMARC III) held at the United States International University- Africa, 15th -17th November, 2016.TBL is a collective learning process through which team members create knowledge, understanding and develops collective competence to solve tasks. It is flexible and learners centered approach It improves individual performance Leads to acquisition of teamwork skills essential in problem solving Develops a process of providing constructive feedback Allows course content and delivery to be fine-tuned to the specific needs of the group Promotes Lifelong learning Increases efficiency and innovation through networking, knowledge sharing and communicatio

Direct Detection of Triterpenoid Saponins in Medicinal Plants

Direct detection of saponins in medicinal plants using Fourier Transform Infrared (FTIR) spectroscopy is reported in this paper. Crude dry plant powders were mixed with potassium bromide (KBr) powder and compressed to a thin pellet for infrared examination. FTIR spectra of the test samples showed -OH, -C=O, C-H, and C=C absorptions characteristic of oleanane triterpenoid saponins. The C-O-C absorptions indicated glycoside linkages to the sapogenins. Phytochemical analysis confirmed the presence of saponins in the tested specimens. Entada leptostachya was used as a reference sample. Dry plant powder was extracted sequentially with hexane, dichloromethane, ethyl acetate and methanol. FTIR spectra of the reference sample powder and its organic solvent extracts showed characteristic saponin absorption peaks. These results indicated that direct detection of saponins in medicinal plants was possible by infrared analysis. Lengthy exhaustive chemical analyses necessary for detection of saponins could be avoided

Antimicrobial Activity of Some Medicinal Plants Used by Herbalists in Eastern Province, Kenya

The aqueous extracts from medicinal plants commonly used by herbalists in Mbeere, and Embu districts of Eastern province, Kenya, were tested for their inhibitory activity against three selected strains of bacteria. All the selected plant extracts (infusions: 1.0g sample in 100 ml water) investigated showed activity against Escherichia coli with inhibition zone diameters ranging from 5.8 – 18.0 mm. Terminalia brownii gave the largest inhibition zones against E. coli and Staphylococcus aureus. Vernonia lasiopus and Tithonia diversifolia were inactive to S. aureus and Bacillus subtilis, respectively. Eighteen and sixteen plants showed sensitivity of greater than 10 mm against S. aureus and B. subtilis, respectively. All control discs gave zones of inhibition of 12 – 24 mm, which were larger than those of the extracts. The present study validated the use of the selected medicinal plants by the herbalists in the treatment of bacterial ailments caused by the strains of bacteria investigated. Medicinal plants used for non-bacterial diseases also exhibited sensitivity towards bacterial strains tested. This implied they could be used as multi-purpose medicinal plants

Traditional Medicines Among the Embu and Mbeere Peoples of Kenya

Ethnobotanical information and traditional medicines were investigated and documented in Embu and Mbeere districts, Eastern Province of Kenya. Oral interviews were obtained from over 100 herbalists, both men and women aged between 40 and 80 years. All the herbalists interviewed were Christians and had little formal education. Non-Christian herbalists were purported to combine herbal medicines with witchcraft and were not interviewed. Of the 40 commonly used herbal plants 25 were used as multi-purpose medicinal plants (mpmp), while 15 were used to treat one disease type. There was a correlation between the outpatient morbidity data at the local District hospital, and the common incident diseases treated by the herbalists. Generally a decoction or infusion of the herb was recommended for the treatment of internal or external condition of the patients. Malaria and typhoid were treatable with a total of 15 and 12 plants respectively and were among the first two commonest diseases found in the study area. Terminalia brownii was found to be the most used medicinal plant either alone or in combination with other herbs. The second and third most utilized medicinal plants were Ovariodendron anisatum and Wurbugia ugadensis respectively

Isolation of cellulose nanofibers from Oryza sativa residues via tempo mediated oxidation

Cellulose nanocrystals (CNCs) or cellulose nanofibers (CNFs) with different morphologies, chemical, mechanical and physical properties can be obtained when microcrystalline cellulose is subjected to enzymatic, chemical or mechanical treatment. With the aim of utilizing cellulose nanofibrils (CNFs) from Oryza sativa, we isolated microcrystalline cellulose using the Kraft process, followed by successive fiber fibrillation using mechanical grinding, then (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO) mediated oxidation. Analysis of pulp fibers obtained after each treatment step revealed that fiber properties such as length, crystallinity and crystal size changed when the pulp was subjected to mechanical grinding, ultrasonication and TEMPO mediated oxidation. The degree of crystallinity of the fibers increased while crystal size and fiber length decreased after each treatment. TEMPO mediated oxidation led to a decrease in fiber length and an increase in degree of crystallinity of the fibers as compared to mechanical treatment and ultrasonication. It further introduced carboxyl functional groups (COOH) on the surface of the fibrils, which implies that the nanofibers obtained in this study could be further functionalized. Hence, TEMPO mediated oxidation offers the possibility of further chemical functionalization of cellulose nanofibers isolated from agricultural residues

Influence of Transesterification Catalysts Synthesized with Citric Acid on the Quality and Oxidative Stability of Biodiesel from Black Soldier Fly Larvae

In biodegradable waste management, use of Black Soldier Fly Larvae (BSFL) is a promising method for bioconversion of waste into crude insect fat as feedstock for biodiesel production. Biodiesel is a renewable alternative to fossil fuel, but it is more susceptible to oxidative degradation over long-term storage. This study investigates the effectiveness of NaOH and CaO catalysts synthesized with citric acid (CA) in improving the oxidative stability of biodiesel. The biodiesel and biodiesel/diesel blends derived from BSFL were stored at 63 °C for 8 days. The quality of biodiesel was determined by analysis of the physicochemical and fuel properties by: Fourier transform infrared (FTIR) spectroscopy, ultraviolet visible spectrophotometer (UV-Vis), gas chromatography-mass spectroscopy (GC-MS), bomb calorimeter and titration methods. Properties that were analyzed included: peroxide value, acid value, iodine value, refractive index, density, calorific value, total oxidation (TOTOX), anisidine value and fatty acid profile. The results showed that catalysts synthesized with CA retarded the decomposition of unsaturated fatty acids, resulting in a significant delay in the formation of hydroperoxides. Besides, 10-oxo-octadecanoic acid, an antioxidant, was present in biodiesel produced using catalysts synthesized with CA, hence enhancing the stability of biodiesel against oxidation. Catalysts synthesized with CA slowed the decomposition of monounsaturated fatty acids by 6.11–11.25%. Overall, biodiesel produced using catalysts synthesized with CA was observed to degrade at a slower rate than biodiesel produced using commercial calcium oxide. The reduced degradation rates demonstrate the effectiveness of the synthesized catalysts in enhancing the oxidation stability and consequently the fuel qualities of biodiesel from BSFL under accelerated storage