Interactome Mapping: Using Protein Microarray Technology to Reconstruct Diverse Protein Networks

A major focus of systems biology is to characterize interactions between cellular components, in order to develop an accurate picture of the intricate networks within biological systems. Over the past decade, protein microarrays have greatly contributed to advances in proteomics and are becoming an important platform for systems biology. Protein microarrays are highly flexible, ranging from large-scale proteome microarrays to smaller customizable microarrays, making the technology amenable for detection of a broad spectrum of biochemical properties of proteins. In this article, we will focus on the numerous studies that have utilized protein microarrays to reconstruct biological networks including protein-DNA interactions, posttranslational protein modifications (PTMs), lectin-glycan recognition, pathogen-host interactions and hierarchical signaling cascades. The diversity in applications allows for integration of interaction data from numerous molecular classes and cellular states, providing insight into the structure of complex biological systems. We will also discuss emerging applications and future directions of protein microarray technology in the global frontier.     

Linking phytochemistry to traditional uses and pharmacology of an underexplored genus – Psydrax: a review

Phytochemistry Reviews - The genus Psydrax is one of the ethno-medicinally important genera of the Rubiaceae family which has only received a limited scientific attention, despite coming from a...     

Comparative metagenomics and functional profiling of crude oil-polluted soils in Bodo West Community,Ogoni, with other sites of varying pollution history

The impact of long-term crude oil pollution on soil microbial community structure in Bodo West Community, Ogoniland, Nigeria, was investigated to determine the amenability of the soil to microbial mediated remediation. Crude oil-polluted and pristine soil samples were collected approximately from 0 to 30 cm depth for both chemical and microbiological analyses. Total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) were determined using gas chromatograph–mass spectrophotometer (GC-MS). The soil microbiome was determined using the Illumina MiSeq platform. Results from this study were then compared with publicly available data from other oil-polluted sites. Taxonomic biomarkers and pathways associated with oil-polluted soils were detected using bioinformatics pipelines. TPH in the polluted and pristine soils were 7591 mg/kg and 199.70 mg/kg respectively, while the values of PAHs were significantly higher (p < 0.05) in the oil-polluted soil. Predictive functional and biomarker analysis demonstrated that microbes detected in the oil-polluted environment were involved in different metabolic pathways for degradation of a broad set of xenobiotic aromatic compounds. Established hydrocarbon degraders belonging to the families Alcanivoracaceae and Oceanospirillaceae were mostly detected in the oil-polluted soils. Sneathiella, Parvibaculum, Sphingobium, and Oceanicaulis were among biomarker taxa. The bacterial families Acidithiobacillaceae and Desulfobacteraceae were differentially more abundant in Bodo West spill site than any other site used for comparison. Furthermore, differentially represented species in our study site and other oil-polluted sites ranged from 21 to 42 bacterial families. The findings from this study revealed the bacterial community had a strong dependence on hydrocarbons and that acid-tolerant bacterial families can as well contribute significantly to biodegradation in the site and other polluted sites in Ogoniland usually known to have an acidic pH. Further research on Bodo West spill site will reveal the novel enzymes and pathways for enhanced microbial mediated eco-restoration.

     

African Program for Onchocerciasis Control 1995–2010: Impact of Annual Ivermectin Mass Treatment on Off-Target Infectious Diseases

Since its initiation in 1995, the African Program for Onchocerciasis Control (APOC) has had a substantial impact on the prevalence and burden of onchocerciasis through annual ivermectin mass treatment. Ivermectin is a broad-spectrum anti-parasitic agent that also has an impact on other co-endemic parasitic infections. In this study, we roughly assessed the additional impact of APOC activities on the burden of the most important off-target infections: soil-transmitted helminthiases (STH; ascariasis, trichuriasis, hookworm, and strongyloidiasis), lymphatic filariasis (LF), and scabies. Based on a literature review, we formulated assumptions about the impact of ivermectin treatment on the disease burden of these off-target infections. Using data on the number of ivermectin treatments in APOC regions and the latest estimates of the burden of disease, we then calculated the impact of APOC activities on off-target infections in terms of disability-adjusted life years (DALYs) averted. We conservatively estimated that between 1995 and 2010, annual ivermectin mass treatment has cumulatively averted about 500 thousand DALYs from co-endemic STH infections, LF, and scabies. This impact comprised approximately an additional 5.5% relative to the total burden averted from onchocerciasis (8.9 million DALYs) and indicates that the overall cost-effectiveness of APOC is even higher than previously reported.     

Cation exchange as a single polishing step for conjugated peptides

Purification of peptides typically includes expensive reverse phase (RP) processes, which utilize high pressure and large volumes of solvent. For two conjugated peptides, chromatography process development targeted a low-pressure aqueous process that could achieve target product purities of ≥95%, comparable to purities seen with traditional RP. A high throughput screening approach of different modalities was used to identify binding and elution conditions on a cation exchange resin and small-scale columns were used in order to assess impurity removal and process yield. The parameters for load and gradient elution were optimized to increase product purity and process productivity with a wide operating window identified where high purity and productivity are achieved. Computational modeling was then used to validate experimental chromatography results and to gain insight on the effect of the chemical modifications on the surface properties of the two peptides. Both modeling and experimental data showed that with optimization, cation exchange could be utilized as a single polishing step for conjugated peptides. Similar purities were achieved as those seen with RP with up to double the productivity.     

Early onset of neurological features differentiates two outbreaks of Lassa fever in Ebonyi state,Nigeria during 2017–2018

Lassa fever (LF) is an acute viral haemorrhagic illness with various non-specific clinical manifestations. Neurological symptoms are rare at the early stage of the disease, but may be seen in late stages, in severely ill patients.The aim of this study was to describe the epidemiological evolution, socio-demographic profiles, clinical characteristics, and outcomes of patients seen during two Lassa fever outbreaks in Ebonyi State, between December 2017 and December 2018.Routinely collected clinical data from all patients admitted to the Virology Centre of the hospital during the period were analysed retrospectively. Out of a total of 83 cases, 70(84.3%) were RT-PCR confirmed while 13 (15.7%) were probable cases. Sixty-nine (83.1%) patients were seen in outbreak 1 of whom 53.6% were urban residents, while 19%, 15%, and 10% were farmers, students and health workers respectively. There were 14 (16.8%) patients, seen in second outbreak with 92.9% rural residents. There were differences in clinical symptoms, signs and laboratory findings between the two outbreaks. The case fatality rates were 29.9% in outbreak 1 and 85.7% for outbreak 2. Neurological features and abnormal laboratory test results were associated with higher mortality rate, seen in outbreak 2. This study revealed significant differences between the two outbreaks. Of particular concern was the higher case fatality during the outbreak 2 which may be from a more virulent strain of the Lassa virus. This has important public health implications and further molecular studies are needed to better define its characteristics.     

New insight into phase behavior and permeability of skin lipid models based on sphingosine and phytosphingosine ceramides

The intercellular lipid matrix of the stratum corneum (SC), which consist mainly of ceramides (CERs), free fatty acids and cholesterol, is fundamental to the skin barrier function. These lipids assemble into two lamellar phases, known as the long and short periodicity phases (LPP and SPP respectively). The LPP is unique in the SC and is considered important for the skin barrier function. Alterations in CER composition, as well as impaired skin barrier function, are commonly observed in diseased skin, yet the understanding of this relationship remains insufficient. In this study, we have investigated the influence of non-hydroxy and α-hydroxy sphingosine-based CERs and their phytosphingosine counterparts on the permeability and lipid organization of model membranes, which were adjusted in composition to enhance formation of the LPP. The permeability was compared by diffusion studies using ethyl-p-aminobenzoate as a model drug, and the lipid organization was characterized by X-ray diffraction and infrared spectroscopy. Both the sphingosine- and phytosphingosine-based CER models formed the LPP, while the latter exhibited a longer LPP repeat distance. The ethyl-p-aminobenzoate flux across the sphingosine-based CER models was higher when compared to the phytosphingosine counterparts, contrary to the fact that the α-hydroxy phytosphingosine-based CER model had the lowest chain packing density. The unanticipated low permeability of the α-hydroxy phytosphingosine-based model is probably associated with a stronger headgroup hydrogen bonding network. Our findings indicate that the increased level of sphingosine-based CERs at the expense of phytosphingosine-based CERs, as observed in the diseased skin, may contribute to the barrier function impairment.     

An epizootic infection of Citrobacter freundii in a guineapig colony: short communication

An epizootic infection of Citrobacter freundii in a guineapig colony is reported. From 1300 guineapigs maintained in a colony, a total of 115 guineapigs died. Lesions found postmortem were suggestive of acute pneumonia and enteritis. Citrobacter freundii was consistently isolated from necropsy specimens of lung, liver, spleen and intestines of the animals. The source of infection was not ascertained.