Perioperative management of renal transplant patients undergoing total joint arthroplasty

The success of renal transplantation depends on lifelong immunosuppression. This can lead to a high incidence of avascular necrosis of major joints in the body for which arthroplasty is the treatment of choice. The risk of surgical complications is high in these patients, and there is no current set of cohesive perioperative management guidelines. In this review, we discuss the perioperative management of renal transplant patients undergoing elective total joint arthroplasty.

Covariance statistics and network analysis of brain PET imaging studies

The analysis of structural and functional neuroimaging data using graph theory has increasingly become a popular approach for visualising and understanding anatomical and functional relationships between different cerebral areas. In this work we applied a network-based approach for brain PET studies using population-based covariance matrices, with the aim to explore topological tracer kinetic differences in cross-sectional investigations. Simulations, test-retest studies and applications to cross-sectional datasets from three different tracers ([18F]FDG, [18F]FDOPA and [11C]SB217045) and more than 400 PET scans were investigated to assess the applicability of the methodology in healthy controls and patients. A validation of statistics, including the assessment of false positive differences in parametric versus permutation testing, was also performed. Results showed good reproducibility and general applicability of the method within the range of experimental settings typical of PET neuroimaging studies, with permutation being the method of choice for the statistical analysis. The use of graph theory for the quantification of [18F]FDG brain PET covariance, including the definition of an entropy metric, proved to be particularly relevant for Alzheimer's disease, showing an association with the progression of the pathology. This study shows that covariance statistics can be applied to PET neuroimaging data to investigate the topological characteristics of the tracer kinetics and its related targets, although sensitivity to experimental variables, group inhomogeneities and image resolution need to be considered when the method is applied to cross-sectional studies.

Patients Presenting with a Hot, Swollen Joint: A Single-Centre Retrospective Analysis

BACKGROUND

A hot, swollen joint is a common clinical condition encountered in the ED and elective orthopaedic and rheumatology clinics. These patients can be difficult to manage and properly treat.

AIMS AND OBJECTIVES

The aim of this study was to report a single centre retrospective analysis of patients presenting to our institution for a hot, swollen joint over a three-month period.

METHODS

The study included patients presenting with a hot, swollen joint to ED or electively to clinics. The synovial fluid was aspirated and sent for microbiological and cytological investigation. P value was set to < 0.001. 36 patients (22 M, 14 F) with a mean age of 72.8 ± 17.4 years met our criteria. 20 cases (55.6 %) involved the knee joint, the wrist in 10 cases (27.8%), the elbow in 3 cases (8.3%) and the shoulder in 3 cases (8.3%).

RESULTS

Of the 36 synovial fluid samples collected, only 7 (19.4%) reported evidence of infection. On cytological examination of the synovial fluid, 21 (58.3%) reported presence of calcium pyrophosphates crystals (Pseudogout), 4 (11.1 %) reported presence of uric acid crystals (Gout) and 11 (30.5%) reported absence of crystals. We found a significant correlation between age and the diagnosis of pseudogout and between previous antibiotic treatment and ED presentation. Our study sheds light on the high incidence of crystal-related pathologies.

CONCLUSION

In order to improve our management of this common condition and enhance our understanding of the clinical diagnosis in certain patient population, further high-profile clinical studies are needed.

Effectiveness and safety of tranexamic acid in total joint arthroplasty

Total joint arthroplasty is associated with significant blood loss, that could result in the need of blood transfusions. Several techniques are being utilised to limit the volume of blood loss, in order to avoid transfusion. In this review, we look at blood loss in total joint arthroplasty and the perioperative strategies to limit the loss of blood. With the use of tranexamic acid gaining popularity, we analyse the published literature on its use in patients undergoing total joint arthroplasty. We have found that published studies favour using tranexamic acid in total joint arthroplasty as a safe and effective method of reducing blood loss.

The Effects of Ageing on Differentiation and Characterisation of Human Mesenchymal Stem Cells

BACKGROUND

Mesenchymal stem cells (MSC) are unique in their ability to self-renew and differentiate into one of many lineage possibilities. It is therefore integral to preserve these qualities to prevent the far reaching effects of a defective stem cell. Human mesenchymal stem cells (hMSC) are precursors for and can differentiate into osteoblasts, adipocytes and chondrocytes. They were originally found in the bone marrow, but have also been located in the umbilical cord, adipose tissue and muscle. Few studies have been conducted into the in vivo effects of age on these cells. This contribution reviews current knowledge surrounding the effects of age on the characteriation and differentiation of human mesenchymal stem cells.

METHOD

471 articles were found using a combination of Online published articles from January 1983 to January 2016 were searched using the Cochrane Library, PubMed, Medline, Scopus, Web of Science and Science Direct databases. There were no existing systematic reviews on this research topic.

RESULTS

Nine studies were identified that met the predefined selection criteria. Three studies were used to assess the effects of ageing on characterisation of hMSC with no conclusive results. The cumulative results of these studies show that the effect of ageing on characterisation of hMSC remains inconclusive. Seven studies were used to assess the differentiation potentials of hMSC showing that age either decreased or altered lineage preference in hMSC differentiation.

CONCLUSION

There is indication that ageing affects hMSC characterisation and differentiation, however it is not conclusive. There are not enough high quality controlled clinical trials to make reliable conclusions.

A case of disseminated tuberculosis mimicking metastatic cancer

BACKGROUND

Disseminated tuberculosis (TB) or miliary TB is defined as lymphohematogenous dissemination of Mycobacterium tuberculosis bacilli, which may then affect virtually any organ system. The multiple organ involvement in disseminated TB can mimic metastatic cancer and can make the diagnosis challenging. False negatives are common therefore repeating microbiologic and histologic samples is essential.

CASE REPORT

We report the case of a young immunocompetent patient presenting with multiple atypical extra-pulmonary TB involvement. The patient presented with pulmonary, pleural, bilateral testicular and multiple bone involvement including calcanerium abscesses. These lesions were initially described as metastasis by the radiologist. Therefore lymphoma and metastatic testicular cancer as well as TB were high on the differential in this young foreign-born male. Pleural, broncho-alveolar lavage, bone marrow and cerebrospinal fluid acid-fast bacilli smear and microbiologic culture were all negative. However the histologic examination of the trans-bronchial biopsy and pleural biopsy showed necrotizing granuloma and helped to narrow down the diagnosis. The patient improved with RIPE therapy.

CONCLUSION

This case illustrates the diagnostic difficulty of disseminated TB with atypical organ involvement. Culture is the gold standard for diagnosing TB but is a long process and with 23% of culture negative TB in the United-States, the diagnosis sometimes relies on thoroughly ruling-out differential diagnosis and histologic examination.

Posterolateral corner injuries: Epidemiology, anatomy, biomechanics and diagnosis

Increased internal and external rotational laxity of the knee may result from a wide range of pathologies in or around the knee. However, the principal cause of increased external rotational laxity is damage to the posterolateral corner (PLC). The aim of the review is to discuss the epidemiology, anatomy, biomechanics and diagnosis of PLC injuries.

006 Effect of apolipoprotein e ε4 allele on medial temporal lobe atrophy in ischaemic stroke patients

Introduction

Apolipoprotein E (APOE) ε4 allele is a known risk factor for the development of cognitive impairment. APOE ε4 carriers have been reported as having lower hippocampal volume in Alzheimer’s disease, mild cognitive impairment, and in healthy cohorts,1 but this is not well investigated in stroke. Here, we compared the regional volume in the medial temporal lobe in ischaemic stroke survivors, with and without the ε4 allele, three (time point 1, t1) and twelve (t2) months after stroke.

Methods

21 APOE ε4 carriers and 21 non-carriers, matched for lesion size and location and for neurological impairment as measured by NIHSS, were sampled from the CANVAS study, a longitudinal imaging study in stroke survivors.2 A mixed-effect linear model was used to analyse the effect of the ε4 allele on hippocampal, entorhinal, and para-hippocampal volumes, adjusting for age, sex, years of education, and total intracranial volume. Volumes were estimated using the longitudinal stream in FreeSurfer 5.3.

Results

The left hippocampal (pt1=0.038, pt2=0.040) and entorhinal (pt1=0.044, pt2=0.038) volumes were significantly lower in the ε4-carrier group at each time point. The right entorhinal (pt1=pt2=0.002) and para-hippocampal (pt1=0.018, pt2=0.020) volumes were also significantly lower in the ε4-carrier group, but there was no difference in the right hippocampal volume (pt1=pt2=0.055) between the two groups. The group-time interaction was significant for the left para-hippocampal cortex (p=0.019): ε4 non-carriers showed a significant volume increase (p=0.018) between t1 and t2.

Conclusion

These findings suggest that stroke survivors who carry the APOE-ε4 allele will experience greater atrophy in the medial temporal lobe in the twelve months following their stroke.

References

1. Manning EN, et al. e4 Is Associated with Disproportionate Progressive Hippocampal Atrophy in AD. PLoS ONE2014;9(5):e97608.

2. Brodtmann A, et al. Charting cognitive and volumetric trajectories after stroke: Protocol for the Cognition And Neocortical Volume After Stroke (CANVAS) study. Int J Stroke2014;9(6):824–828.

Total knee arthroplasty in patients with prior adjacent multi-organism osteomyelitis

Joint degeneration may make a total knee replacement a requirement for pain relief and function, however the presence of adjacent osteomyelitis makes management extremely challenging. We describe a series of four patients with a mean age of 50 with multi-organism osteomyelitis who underwent single-stage total knee replacements at an average of 63 months following eradication. Three patients did well but had complications associated with poor skin and soft tissues, and abnormal bone anatomy. One patient developed an infection and following a re-revision had an arthrodesis. The final mean Knee Society Score and Oxford Knee Score was 62 (54-66) and 34 (29-38) respectively. We have highlighted that these are a difficult cohort of patients to manage and their care is optimised through a multi-disciplinary approach by a high volume surgeon.

Ethno-botanical and geo-referenced profiling of medicinal plants of Nawagai Valley, District Buner (Pakistan)

The prime objective of the research was to list the important ethnomedicinal plants of Nawagai village, District Buner. During the survey, 44 plant species from 27 families were observed and collected from the targeted area of Khyber Pakhtunkhwa, Pakistan. Lamiaceae members were the most dominant (54%) followed by members of Asteraceae (30%), Poaceae (18%) and Solanaceae (12%). Relevant information such as field data, GPS coordinates family names, local names, therapeutic uses and plant habits were recorded for each species. For preservation purposes, specimens were mounted on herbarium sheets, and identified with the help of flora of Pakistan, flora of Australia and other relevant floristic records. During this research work all the collected specimens were preserved in the (BG&H, UOM) Botanical Garden and Herbarium, the data were also provided to the Department of Botany, University of Malakand Dir (Lower), Khyber Pakhtunkhwa, Pakistan.

A Multi-Cohort Study of ApoE ɛ4 and Amyloid-β Effects on the Hippocampus in Alzheimer's Disease

The apolipoprotein E (APOE) gene has been consistently shown to modulate the risk of Alzheimer’s disease (AD). Here, using an AD and normal aging dataset primarily consisting of three AD multi-center studies (n = 1,781), we compared the effect of APOE and amyloid-β (Aβ) on baseline hippocampal volumes in AD patients, mild cognitive impairment (MCI) subjects, and healthy controls. A large sample of healthy adolescents (n = 1,387) was also used to compare hippocampal volumes between APOE groups. Subjects had undergone a magnetic resonance imaging (MRI) scan and APOE genotyping. Hippocampal volumes were processed using FreeSurfer. In the AD and normal aging dataset, hippocampal comparisons were performed in each APOE group and in ɛ4 carriers with positron emission tomography (PET) Aβ who were dichotomized (Aβ+/Aβ–) using previous cut-offs. We found a linear reduction in hippocampal volumes with ɛ4 carriers possessing the smallest volumes, ɛ3 carriers possessing intermediate volumes, and ɛ2 carriers possessing the largest volumes. Moreover, AD and MCI ɛ4 carriers possessed the smallest hippocampal volumes and control ɛ2 carriers possessed the largest hippocampal volumes. Subjects with both APOE ɛ4 and Aβ positivity had the lowest hippocampal volumes when compared to Aβ- ɛ4 carriers, suggesting a synergistic relationship between APOE ɛ4 and Aβ. However, we found no hippocampal volume differences between APOE groups in healthy 14-year-old adolescents. Our findings suggest that the strongest neuroanatomic effect of APOE ɛ4 on the hippocampus is observed in AD and groups most at risk of developing the disease, whereas hippocampi of old and young healthy individuals remain unaffected.

ntra-species profiling of Cleome viscosa growing in Swat district (Pakistan)

Intra-specific genetic variation was studied in 28 genotypes of Cleome viscosa L. growing in Swat district, Khyber Pakhtunkhwa, Pakistan. It was found that genotypes showed the utmost allelic variation for leaf upper and lower surface with emerald green (75%), and yellow green (75%) respectively, other leaves lower and upper surfaces were (25%) green and yellow green (26%) respectively. The majority of C. viscosa genotypes were (50%) yellow flowers while others were with (29%) white yellow colour and (21%) dull yellow. Most of the seeds were with black (46%). The protein profiling was carried out on 12% gel electrophoresis; seven reproducible bands with molecular weight ranges from 180 to 10 KDa were detected in C. viscosa, the locus contribution toward genetic disagreement (LCTGD) of C. viscosa was 57%. Notably, L-3, L-4 L-5, was monomorphic in C. viscosa and was treated as species specific. L-1, L-2, L-7 were polymorphic. These bands showed 79%, 4%, 14% and 79% variation respectively. In the current investigation the intra-specific variation was observed limited and alone SDS-PAGE did not determine the high level of intra-specific variation; however, diverse germplasm were suggested to be acquired from various sources.

Development and small-scale validation of a novel pigeon-associated mitochondrial DNA source tracking marker for the detection of fecal contamination in harvested rainwater

The current study was aimed at designing and validating (on a small-scale) a novel pigeon mitochondrial DNA (mtDNA) microbial source tracking (MST) marker for the detection of pigeon fecal matter in harvested rainwater. The pigeon mtDNA MST marker was designed to target the mtDNA Cytochrome b gene by employing mismatch amplification mutation assay kinetics. The pigeon marker was validated by screening 69 non-pigeon and 9 pigeon fecal samples. The host-sensitivity of the assay was determined as 1.00 while the host-specificity of the assay was 0.96. Harvested rainwater samples (n=60) were screened for the prevalence of the marker with the mtDNA Cytochrome b marker detected in 78% of the samples. Bayes' theorem was applied to calculate the conditional probability of the marker detecting true pigeon contamination and the marker subsequently displayed a 99% probability of detecting true pigeon contamination in the harvested rainwater samples. In addition, the mtDNA Cytochrome b marker displayed high concurrence frequencies versus heterotrophic bacteria (78.3%), E. coli (73.3%), total coliforms (71.1%) and fecal coliforms (66.7%). This study thus validates that targeting mtDNA for the design of source tracking markers may be a valuable tool to detect avian fecal contamination in environmental waters.

Microbial source tracking markers associated with domestic rainwater harvesting systems: Correlation to indicator organisms

Domestic rainwater harvesting (tank water) systems were screened for the presence of a panel of microbial source tracking (MST) markers and traditional indicator organisms. The indicator organisms were enumerated utilizing traditional culture-based methods, while the MST markers were quantified by quantitative PCR (qPCR). The indicators Escherichia coli (E. coli) and enterococci were also quantified using qPCR. Correlations and concurrence between these parameters were then investigated to determine which markers could be utilized to supplement traditional indicator analysis. Quantitative PCR analysis indicated that Bacteroides HF183, adenovirus, Lachnospiraceae and E. coli were detected and quantifiable in 100% of the tank water samples collected throughout the sampling period, while human mitochondrial DNA (mtDNA) was quantifiable in 90% of the tank water samples and Bifidobacterium adolescentis (B. adolescentis) and enterococci were quantifiable in 67% of the tank water samples, respectively. Significant positive correlations were recorded for Lachnospiraceae versus heterotrophic bacteria (p = 0.000), adenovirus versus E. coli (culturing) (p = 0.000) and heterotrophic bacteria (p = 0.024), the HF183 marker versus E. coli (qPCR) (p = 0.024) and B. adolescentis versus fecal coliforms (p = 0.037). In addition, 100% concurrence was observed for the HF183 marker, adenovirus and Lachnospiraceae versus E. coli (qPCR), enterococci (qPCR) and heterotrophic bacteria, amongst others. Based on the correlations and the concurrence analysis, the HF183 marker, Lachnospiraceae and adenovirus may be utilized to supplement indicator organism analysis for the monitoring of harvested rainwater quality.

Mesenchymal stem cells in human meniscal regeneration: A systematic review

BACKGROUND

Stem cell regeneration is the holy grail of meniscal tissue repair. Currently, the best treatment is to preserve the original meniscus but if it fails, a partial meniscectomy is indicated to delay the onset of osteoarthritis.

MATERIALS AND METHODS

The authors present a systematic review to determine the up-to-date evidence underlying the use of mesenchymal stem cells for meniscal regeneration in humans. A search was conducted using the electronic databases of MEDLINE/Pubmed, Google scholar, and the Cochrane Collaboration. Search keywords included human, meniscus, stem cells and regeneration.

RESULTS

After screening 10 non-duplicate studies, 5 were identified based on title and abstract. 4 were included in the analysis. There were marked differences in the method of stem cell harvest techniques. 3 studies administered stem cells through percutaneous injection into the knee and 1 study used a collagen scaffold. MRI analysis, functional scores and safety were assessed and the longest follow-up period was 2 years. The Visual Analogue Score (VAS) was most commonly used to assess function and patients generally showed an improvement. There were no reported adverse events.

CONCLUSION

Despite positive results from animal models, there is currently a lack of evidence in humans to conclude that stem cells can form durable neotissue similar to original human meniscus. There is a need for standardisation of protocol before further trials are considered. Initial outcomes from human studies are promising and mesenchymal stem cells may play an important role in meniscal repair in years to come.