Genomic Epidemiology of Mycobacterium abscessus on the Island of Montréal Not Suggestive of Healthcare-associated Person-to-Person Transmission.

BACKGROUND: Mycobacterium abscessus complex (MABC), an opportunistic nontuberculous mycobacteria (NTM), can lead to poor clinical outcomes in pulmonary infections. Conflicting data exist on person-to-person transmission of MABC within and across healthcare facilities. To investigate further, a comprehensive retrospective study across five healthcare institutions on the Island of Montréal was undertaken. METHODS: We analyzed the genomes of 221 MABC isolates obtained from 115 individuals (2010-2018) to identify possible links. Genetic similarity, defined as ≤25 single-nucleotide polymorphisms (SNPs), was investigated through a blinded epidemiological inquiry. RESULTS: Bioinformatics analyses identified 28 sequence types (STs), including globally observed dominant circulating clones (DCCs). Further analysis revealed 210 isolate pairs within the SNP threshold. Among these pairs, there was one possible lab contamination where isolates from different patients processed in the same lab differed by only 2 SNPs. There were 37 isolate pairs from patients who had provided specimens from the same hospital; however, epidemiological analysis found no evidence of healthcare-associated person-to-person transmission between these patients. Additionally, pan-genome analysis showed higher discriminatory power than core genome analysis for examining genomic similarity. CONCLUSIONS: Genomics alone is insufficient to establish MABC transmission, particularly considering the genetic similarity and wide distribution of DCCs, although pan-genome analysis has the potential to add further insight. Our findings indicate that MABC infections in Montréal are unlikely attributable to healthcare-associated person-to-person transmission.

Aetiological Spectrum of Pancreaticobiliary Diseases in Adult Nigerians on Magnetic Resonance Cholangiopancreatography.

BACKGROUND: Imaging is vital for assessing pancreaticobiliary diseases. AIM: The aim of the study was to investigate the spectrum and pattern of pancreaticobiliary diseases in adult Nigerians using magnetic resonance cholangiopancreatography (MRCP). METHODS: This was a retrospective, descriptive cross-sectional study. The electronic radiological records of 110 adult Nigerians who had undergone MRCP were reviewed. The MRCP images were evaluated for bile duct dilatation, intraluminal filling defects, strictures, calculi, and other abnormalities. RESULTS: There were 45 males (40.9%) and 65 females (59.1%) aged 18-83 years, with a mean age of 51.93 ± 15.22 years. Jaundice (59.1%) and right hypochondrial pain (31.8%) were the most common presenting complaints. Gallstones (32.7%), common bile duct strictures (15.5%), choledocholithiasis (11.8%), pancreatic head carcinoma (10.9%), and gallbladder carcinoma (2.7%) were the most frequent abnormalities. There was biliary obstruction in 56.4% of participants, mostly at the distal and proximal common bile duct. Other findings include hepatomegaly (23.6%), hepatic cysts (6.4%), hepatic steatosis (0.9%), duodenal wall thickening (1.8%), and ascites (5.5%). MRCP was normal in 25 (22.7%) participants. CONCLUSION: Gallstones were the predominant pathology of the various pancreaticobiliary diseases, while Pancreatic head and gallbladder carcinoma were the most common malignant diseases.

Comparison of the clinical characteristics of SARS-CoV-2 Delta (B.1.617.2) and Omicron (B.1.1.529) infected patients from a single hospitalist service.

BACKGROUND: While existing evidence suggests less severe clinical manifestations and lower mortality are associated with the Omicron variant as compared to the Delta variant. However, these studies fail to control for differences in health systems facilities and providers. By comparing patients hospitalized on a single medical service during the Delta and Omicron surges we were able to conduct a more accurate comparison of the two varaints' clinical manifestations and outcomes. METHODS: We conducted a prospective study of 364 Omicron (BA.1) infected patients on a single hospitalist service and compared these findings to a retrospective analysis of 241 Delta variant infected patients managed on the same service. We examined differences in symptoms, laboratory measures, and clinical severity between the two variants and assessed potential risk drivers for case mortality. FINDINGS: Patients infected with Omicron were older and had more underlying medical conditions increasing their risk of death. Although they were less severely ill and required less supplemental oxygen and dexamethasone, in-hospital mortality was similar to Delta cases, 7.14% vs. 4.98% for Delta (q-value = 0.38). Patients older than 60 years or with immunocompromised conditions had much higher risk of death during hospitalization, with estimated odds ratios of 17.46 (95% CI: 5.05, 110.51) and 2.80 (1.03, 7.08) respectively. Neither vaccine history nor variant type played a significant role in case fatality. The Rothman score, NEWS-2 score, level of neutrophils, level of care, age, and creatinine level at admission were highly predictive of in-hospital death. INTERPRETATION: In hospitalized patients, the Omicron variant is less virulent than the Delta variant but is associated with a comparable mortality. Clinical and laboratory features at admission are informative about the risk of death.

Correlation of sonographic inferior vena cava and aorta diameter ratio with dehydration in Nigerian children.

BACKGROUND: Accurate assessment of the degree of dehydration is essential in the management and fluid therapy of dehydrated children. The invasiveness of central venous pressure limits its routine clinical use. Fortunately, some studies have suggested that ultrasonographic measurement of inferior vena cava (IVC) diameter: aorta diameter ratio (IADR) is an objective method of assessing intravascular volume. OBJECTIVES: To determine the clinical usefulness of ultrasound measurement of IADR in assessment of children with dehydration. METHODOLOGY: This was a cross-sectional study which compared dehydrated children to age- and sex-matched euvolemic healthy children as controls. The maximum anteroposterior diameter of the abdominal aorta (at peak systole) and maximum IVC diameter (in expiration) were measured. RESULTS: A total of 120 subjects and 120 controls were evaluated. The mean age was 21.73 ± 20.89 months for subjects and 21.19 ± 22.13 months for control. The mean IADR for children with mild, moderate, and severe dehydration was 0.75 ± 0.07, 0.55 ± 0.07, and 0.33 ± 0.05, respectively. The mean IADR for controls was 0.99 ± 0.06. IADR had an inverse relationship with the degree of dehydration in the subjects. A cut-off point of 0.86, with a sensitivity and specificity of 96.7% in predicting dehydration, was derived, with the sensitivity and specificity increasing with increasing level of dehydration. CONCLUSION: IADR is sensitive and specific for assessing moderate and severe dehydration in Nigerian children.

Ultrasound evaluation of obstructive uropathy and its hemodynamic responses in southwest Nigeria.

PURPOSE: To determine the renal arterial hemodynamic changes induced by obstructive uropathy using Doppler ultrasonography. MATERIALS AND METHODS: 60 adult subjects with suspected obstructive uropathy and 60 asymptomatic apparently healthy controls with normal renal ultrasound features were evaluated. B-mode sonography of the kidneys and spectral Doppler examination of the renal interlobar arteries of all the participants were performed. The mean resistive indices (mRI) of both interlobar arteries were obtained and compared to that of the controls. The mRI of bilaterally obstructed kidneys were also compared with the mRI of unilaterally obstructed kidneys. RESULTS: The mRI of the right and left kidneys of subjects were 0.72±0.04 and 0.69±0.06 while those of the controls were 0.64±0.04 and 0.63±0.03 respectively. The mRI for the grades of caliectasis increased from grade I (0.72±0.03) to grade II (0.73±0.03) and grade III (0.73±0.02) but fell within the most severe levels of obstruction (0.69±0.07). There was no statistically significant relationship between the grades of caliectasis and unilateral or bilateral obstruction for both kidneys. The results show a sensitivity and specificity of 86.7% and 90% respectively when mRI≥0.7 was used to determine presence of obstruction. CONCLUSION: Renal duplex sonography is highly sensitive and specific for diagnosis of obstructive uropathy. Increased resistive index of the obstructed kidney may be a useful diagnostic tool in situations where intravenous urography cannot be done or is contraindicated.

Genomic Characterization of Multidrug-Resistant Pathogenic Enteric Bacteria from Healthy Children in Osun State, Nigeria.

Antimicrobial resistance (AMR) is responsible for the spread and persistence of bacterial infections. Surveillance of AMR in healthy individuals is usually not considered, though these individuals serve as reservoirs for continuous disease transmission. Therefore, it is essential to conduct epidemiological surveillance of AMR in healthy individuals to fully understand the dynamics of AMR transmission in Nigeria. Thirteen multidrug-resistant Citrobacter spp., Enterobacter spp., Klebsiella pneumoniae, and Escherichia coli isolated from stool samples of healthy children were subjected to whole genome sequencing (WGS) using Illumina and Oxford nanopore sequencing platforms. A bioinformatics analysis revealed antimicrobial resistance genes such as the pmrB_Y358N gene responsible for colistin resistance detected in E. coli ST219, virulence genes such as senB, and ybtP&Q, and plasmids in the isolates sequenced. All isolates harbored more than three plasmid replicons of either the Col and/or Inc type. Plasmid reconstruction revealed an integrated tetA gene, a toxin production caa gene in two E. coli isolates, and a cusC gene in K. quasivariicola ST3879, which induces neonatal meningitis. The global spread of AMR pathogenic enteric bacteria is of concern, and surveillance should be extended to healthy individuals, especially children. WGS for epidemiological surveillance will improve the detection of AMR pathogens for management and control.

Molecular characterization of non-aureus staphylococci and Mammaliicoccus from Hipposideros bats in Southwest Nigeria.

Bats are not only ecologically valuable mammals but also reservoirs of zoonotic pathogens. Their vast population, ability to fly, and inhabit diverse ecological niches could play some role in the spread of antibiotic resistance. This study investigated non-aureus staphylococci and Mammaliicoccus colonization in the Hipposideros bats at Obafemi Awolowo University, Ile-Ife, Nigeria. Pharyngeal samples (n = 23) of the insectivorous bats were analyzed, and the presumptive non-aureus staphylococcal and Mammaliicoccus isolates were confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The isolates were characterized based on antibiotic susceptibility testing and whole-genome sequencing (WGS). Six bacterial genomes were assembled, and three species were identified, including Mammaliicoccus sciuri (n = 4), Staphylococcus gallinarum (n = 1), and Staphylococcus nepalensis (n = 1). All the isolates were resistant to clindamycin, while the M. sciuri and S. gallinarum isolates were also resistant to fusidic acid. WGS analysis revealed that the M. sciuri and S. gallinarum isolates were mecA-positive. In addition, the M. sciuri isolates possessed some virulence (icaA, icaB, icaC, and sspA) genes. Multi-locus sequence typing identified two new M. sciuri sequence types (STs) 233 and ST234. The identification of these new STs in a migratory mammal deserves close monitoring because previously known ST57, ST60, and ST65 sharing ack (8), ftsZ (13), glpK (14), gmk (6), and tpiA (10) alleles with ST233 and ST234 have been linked to mastitis in animals. Moreover, the broad host range of M. sciuri could facilitate the dispersal of antibiotic resistance genes. This study provides evidence of the importance of including migratory animals in monitoring the development and spread of antibiotic resistance.

Genomic Characterisation of Multidrug-Resistant Pathogenic Enteric Bacteria from healthy children in Osun State, Nigeria.

Antimicrobial resistance (AMR) has been established to be a significant driver for the persistence and spread of bacterial infections. It is, therefore, essential to conduct epidemiological surveillance of AMR in healthy individuals to understand the actual dynamics of AMR in Nigeria. Multi-drug resistant Klebsiella quasivariicola (n=1), Enterobacter hormaechei (n=1), and Escherichia coli (n=3) from stool samples of healthy children were subjected to whole genome sequencing using Illumina Nextseq1000/2000 and Oxford nanopore. Bioinformatics analysis reveals antimicrobial resistance, virulence genes, and plasmids. This pathogenic enteric bacteria harbored more than three plasmid replicons of either Col and/or Inc type associated with outbreaks and AMR resistant gene pmrB responsible for colistin resistance. Plasmid reconstruction revealed an integrated tetA gene responsible for tetracycline resistance, and caa gene responsible for toxin production in two of the E.coli isolates, and a cusC gene known to induce neonatal meningitis in the K. quasivariicola ST3879. The global spread of MDR pathogenic enteric bacteria is a worrying phenomenon, and close surveillance of healthy individuals, especially children, is strongly recommended to prevent the continuous spread and achieve the elimination and eradication of these infections. Molecular epidemiological surveillance using whole genome sequencing (WGS) will improve the detection of MDR pathogens in Nigeria.

The Prevalence of Undiagnosed Salmonella enterica Serovar Typhi in Healthy School-Aged Children in Osun State, Nigeria.

Typhoid fever remains a significant public health concern due to cases of mis-/overdiagnosis. Asymptomatic carriers play a role in the transmission and persistence of typhoid fever, especially among children, where limited data exist in Nigeria and other endemic countries. We aim to elucidate the burden of typhoid fever among healthy school-aged children using the best surveillance tool(s). In a semi-urban/urban state (Osun), 120 healthy school-aged children under 15 years were enrolled. Whole blood and fecal samples were obtained from consenting children. ELISA targeting the antigen lipopolysaccharide (LPS) and anti-LPS antibodies of Salmonella Typhi, culture, polymerase chain reaction (PCR), and next-generation sequencing (NGS) were used to analyze the samples. At least one of the immunological markers was detected in 65.8% of children, with 40.8%, 37.5%, and 39% of children testing positive for IgM, IgG, and antigen, respectively. Culture, PCR, and NGS assays did not detect the presence of Salmonella Typhi in the isolates. This study demonstrates a high seroprevalence of Salmonella Typhi in these healthy children but no carriage, indicating the inability to sustain transmission. We also demonstrate that using a single technique is insufficient for typhoid fever surveillance in healthy children living in endemic areas.

Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria.

Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates.

Emergence and Genomic Characterization of Multidrug Resistant Candida auris in Nigeria, West Africa.

Candida auris is an emerging multidrug-resistant fungal pathogen that has become a worldwide public health threat due to the limitations of treatment options, difficulty in diagnosis, and its potential for clonal transmission. Four ICU patients from three different healthcare facilities in Southern Nigeria presented features suggestive of severe sepsis and the blood cultures yielded the growth of Candida spp., which was identified using VITEK 2 as C. auris. Further confirmation was performed using whole genome sequencing (WGS). From the genomic analysis, two had mutations that conferred resistance to the antifungal azole group and other non-synonymous mutations in hotspot genes, such as ERG2, ERG11, and FKS1. From the phylogenetic analysis, cases 2 and 4 had a confirmed mutation (ERG11:Y132F) that conferred drug resistance to azoles clustered with clade 1, whilst cases 1 and 3 clustered with clade 4. Three of the patients died, and the fourth was most likely a case of colonization since he received no antifungals and was discharged home. These first cases of C. auris reported from Nigeria were most likely introduced from different sources. It is of public health importance as it highlights diagnostic gaps in our setting and the need for active disease surveillance in the region.

Future-proofing and maximizing the utility of metadata: The PHA4GE SARS-CoV-2 contextual data specification package.

BACKGROUND: The Public Health Alliance for Genomic Epidemiology (PHA4GE) (https://pha4ge.org) is a global coalition that is actively working to establish consensus standards, document and share best practices, improve the availability of critical bioinformatics tools and resources, and advocate for greater openness, interoperability, accessibility, and reproducibility in public health microbial bioinformatics. In the face of the current pandemic, PHA4GE has identified a need for a fit-for-purpose, open-source SARS-CoV-2 contextual data standard. RESULTS: As such, we have developed a SARS-CoV-2 contextual data specification package based on harmonizable, publicly available community standards. The specification can be implemented via a collection template, as well as an array of protocols and tools to support both the harmonization and submission of sequence data and contextual information to public biorepositories. CONCLUSIONS: Well-structured, rich contextual data add value, promote reuse, and enable aggregation and integration of disparate datasets. Adoption of the proposed standard and practices will better enable interoperability between datasets and systems, improve the consistency and utility of generated data, and ultimately facilitate novel insights and discoveries in SARS-CoV-2 and COVID-19. The package is now supported by the NCBI's BioSample database.

Studies on the prevalence of urinary schistosomiasis in Ogun State, South-Western Nigeria.

BACKGROUND: The assessment of the extent and distribution of Schistosoma infection in every region in Nigeria is important and required for formulating intervention strategies suitable for each endemic area. OBJECTIVE: To assess the prevalence of urinary schistosomiasis in Ogun State, South-West Nigeria. METHODS: Urine samples of pupils were examined for schistosoma eggs by sedimentation technique among selected primary school children. Pretested and structured questionnaires were also administered for KAP studies. RESULTS: The overall prevalence of 32.2% was observed for schistosomiasis in 276 pupils. Peak prevalence of urinary schistosomiasis infection (36.2%) was found in 8-10 years age group. Thirty-seven percent reported passing blood in urine, about 50% of these informed their parents but 53.1% of the parents did nothing. Contact with stream water played a significant role in the transmission of urinary schistosomiasis as 80.9% of those infected used the stream water for domestic and recreational purposes. There was no significant difference (Χ² =0.0489, P>0.05 = 0.0489, P>0.05) between infection status among males and females. CONCLUSION: There is need for control measures in this area in order to curb the high prevalence of schistosomiasis.

Whole genome sequencing of clinical samples reveals extensively drug resistant tuberculosis (XDR TB) strains from the Beijing lineage in Nigeria, West Africa.

Multi-drug (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) continues to be a global public health problem especially in high TB burden countries like Nigeria. Many of these cases are undetected and go on to infect high risk individuals. Clinical samples from positive rifampicin resistant Xpert®MTB/Rif assay were subjected to direct whole genome sequencing and bioinformatics analysis to identify the full antibiotics resistance and lineage profile. We report two (2) XDR TB samples also belonging to the East-Asian/Beijing family of lineage 2 Mycobacterium tuberculosis complex from clinical samples in Nigeria. Our findings further reveal the presence of mutations that confer resistance to first-line drugs (rifampicin, isoniazid, ethambutol and pyrazanimide), second-line injectables (capreomycin, streptomycin, kanamycin and/or amikacin) and at least one of the fluoroquinolones (ofloxacin, moxifloxacin, levofloxacin and/or ciprofloxacin) in both samples. The genomic sequence data from this study not only provide the first evidence of XDR TB in Nigeria and West Africa, but also emphasize the importance of WGS in accurately detecting MDR and XDR TB, to ensure adequate and proper management treatment regimens for affected individuals. This will greatly aid in preventing the spread of drug resistance TB in high burden countries.

The Bacteria Genome Pipeline (BAGEP): an automated, scalable workflow for bacteria genomes with Snakemake.

Next generation sequencing technologies are becoming more accessible and affordable over the years, with entire genome sequences of several pathogens being deciphered in few hours. However, there is the need to analyze multiple genomes within a short time, in order to provide critical information about a pathogen of interest such as drug resistance, mutations and genetic relationship of isolates in an outbreak setting. Many pipelines that currently do this are stand-alone workflows and require huge computational requirements to analyze multiple genomes. We present an automated and scalable pipeline called BAGEP for monomorphic bacteria that performs quality control on FASTQ paired end files, scan reads for contaminants using a taxonomic classifier, maps reads to a reference genome of choice for variant detection, detects antimicrobial resistant (AMR) genes, constructs a phylogenetic tree from core genome alignments and provide interactive short nucleotide polymorphism (SNP) visualization across core genomes in the data set. The objective of our research was to create an easy-to-use pipeline from existing bioinformatics tools that can be deployed on a personal computer. The pipeline was built on the Snakemake framework and utilizes existing tools for each processing step: fastp for quality trimming, snippy for variant calling, Centrifuge for taxonomic classification, Abricate for AMR gene detection, snippy-core for generating whole and core genome alignments, IQ-TREE for phylogenetic tree construction and vcfR for an interactive heatmap visualization which shows SNPs at specific locations across the genomes. BAGEP was successfully tested and validated with Mycobacterium tuberculosis (n = 20) and Salmonella enterica serovar Typhi (n = 20) genomes which are about 4.4 million and 4.8 million base pairs, respectively. Running these test data on a 8 GB RAM, 2.5 GHz quad core laptop took 122 and 61 minutes on respective data sets to complete the analysis. BAGEP is a fast, calls accurate SNPs and an easy to run pipeline that can be executed on a mid-range laptop; it is freely available on: https://github.com/idolawoye/BAGEP.

Potential therapeutic targets for chordoma: PI3K/AKT/TSC1/TSC2/mTOR pathway.

Chordomas are radio- and chemo-resistant tumours and metastasise in as many as 40% of patients. The aim of this study was to identify potential molecular targets for the treatment of chordoma. In view of the reported association of chordoma and tuberous sclerosis complex syndrome, and the available therapeutic agents against molecules in the PI3K/AKT/TSC1/TSC2/mTOR pathway, a tissue microarray of 50 chordoma cases was analysed for expression of active molecules involved in this signalling pathway by immunohistochemistry and a selected number by western blot analysis. Chordomas were positive for p-AKT (92%), p-TSC2 (96%), p-mTOR (27%), total mTOR (75%), p-p70S6K (62%), p-RPS6 (22%), p-4E-BP1 (96%) and eIF-4E (98%). Phosphatase and tensin homologue deleted on chromosome 10 expression was lost in 16% of cases. Mutations failed to be identified in PI3KCA and RHEB1 in the 23 cases for which genomic DNA was available. Fluorescence in situ hybridisation analysis for mTOR and RPS6 loci showed that 11 of 33 and 21 of 44 tumours had loss of one copy of the respective genes, results which correlated with the loss of the relevant total proteins. Fluorescence in situ hybridisation analysis for loci containing TSC1 and TSC2 revealed that all cases analysed harboured two copies of the respective genes. On the basis of p-mTOR and or p-p70S6K expression there is evidence indicating that 65% of the chordomas studied may be responsive to mTOR inhibitors, rapamycin or its analogues, and that patients may benefit from combined therapy including drugs that inhibit AKT.

ADELOLA ADELOYE: QUINTESSENTIAL NEUROLOGICAL SURGEON, NEUROLOGIST, DISTINGUISHED ACADEMIC, MEDICAL HISTORIAN, AND BIOGRAPHER.

Adelola Adeloye (formerly Rufus Bandele Adelola Adeloye) is the second Nigerian doctor to qualify as a Neurological surgeon in 1967, having trained in Nigeria, United Kingdom and the United States of America. He worked with the College of Medicine, University of Ibadan and the University College Hospital, Ibadan as an academic Neurosurgeon and honorary Consultant Neurosurgeon, respectively from 1968 to 1995. He subsequently took up appointments in Saudi Arabia, Kuwait, and Malawi where he served in various capacities. He garnered panoply of academic and professional qualifications in the course of his career, matched by an equally prolific array of scholarly publications on diverse subjects. The high points of his career would include the landmark description of the Adeloye-Odeku disease in 1971, helping to institutionalise local Neurosurgical training in Nigeria, helping to set up a Surgery department in the then fledgling Medical School in Malawi, his election as an honorary Fellow of the American College of Surgeons and honorary President of the World Federation of Neurosurgical Societies, as well as his appointment as an Emeritus Professor of Neurosurgery by the University of Ibadan. An altruistic and far-sighted man, he ensured that the first Nigerian Neurosurgeon who died prematurely and other Nigerian/African pioneers of Medicine/Neurosurgery are properly immortalised by a painstaking and selfless documentation of their lives and contributions. Biographies of Prof E. Latunde Odeku (Nigeria's first Neurosurgeon and the first Black Neurosurgeon trained on US soil), Dr James Africanus Beale Horton, and other such writings are testament to this.

Osteoporosis and ageing affects the migration of stem cells and this is ameliorated by transfection with CXCR4.

OBJECTIVES: Cellular movement and relocalisation are important for many physiologic properties. Local mesenchymal stem cells (MSCs) from injured tissues and circulating MSCs aid in fracture healing. Cytokines and chemokines such as Stromal cell-derived factor 1(SDF-1) and its receptor chemokine receptor type 4 (CXCR4) play important roles in maintaining mobilisation, trafficking and homing of stem cells from bone marrow to the site of injury. We investigated the differences in migration of MSCs from the femurs of young, adult and ovariectomised (OVX) rats and the effect of CXCR4 over-expression on their migration. METHODS: MSCs from young, adult and OVX rats were put in a Boyden chamber to establish their migration towards SDF-1. This was compared with MSCs transfected with CXCR4, as well as MSCs differentiated to osteoblasts. RESULTS: MSCs from OVX rats migrate significantly (p < 0.05) less towards SDF-1 (9%, sd 5%) compared with MSCs from adult (15%, sd 3%) and young rats (25%, sd 4%). Cells transfected with CXCR4 migrated significantly more towards SDF-1 compared with non-transfected cells, irrespective of whether these cells were from OVX (26.5%, sd 4%), young (47%, sd 17%) or adult (21%, sd 4%) rats. Transfected MSCs differentiated to osteoblasts express CXCR4 but do not migrate towards SDF-1. CONCLUSIONS: MSC migration is impaired by age and osteoporosis in rats, and this may be associated with a significant reduction in bone formation in osteoporotic patients. The migration of stem cells can be ameliorated by upregulating CXCR4 levels which could possibly enhance fracture healing in osteoporotic patients.Cite this article: A. Sanghani-Kerai, M. Coathup, S. Samazideh, P. Kalia, L. Di Silvio, B. Idowu, G. Blunn. Osteoporosis and ageing affects the migration of stem cells and this is ameliorated by transfection with CXCR4. Bone Joint Res 2017;6:-365. DOI: 10.1302/2046-3758.66.BJR-2016-0259.R1.

Stabilization of fibronectin mats with micromolar concentrations of copper.

Fibronectin, a large extracellular matrix cell adhesion glycoprotein has diverse functions in wound repair including organization of matrix deposition and promotion of angiogenesis. We have previously shown that purified plasma fibronectin can be made into three-dimensional, fibrous materials, termed fibronectin mats (Fn-mat). The aim of this study was to examine means of increasing the stability of Fn-mats using a novel treatment with micromolar concentrations of copper ions which may be used to improve wound healing/nerve repair. Cytotoxicity of incorporated copper was determined using rat Schwann cells, rat tendon fibroblasts and human dermal fibroblasts. Dissolution of protein from the Fn-mat showed that treatment with the lowest concentration of copper used (1 microM) increased the stability of mats by 3-4 times at room temperature relative to control mats and twofold at 37 degrees C. Copper mediated increase in stability was dose dependent. Orientation of the Fn-fibres (within mats), monitored by scanning electron microscopy was retained with 1 microM copper but disappeared with higher concentrations. Schwann cells grew in culture with mats stabilized by 1 microM copper treatment without reduction in cell number but growth was inhibited at 10-200 microM Cu. All types of fibroblasts were unaffected by copper treatment upto 200 microM. Fn-mats can be successfully stabilized by this technique producing longer survival in vitro. The differential effects of copper on these cell types suggests that CuFn-mats may be used to select the type of cells which colonize these materials.