Trace element contaminants associated with historic gold mining in sediments of dams and pans across Benoni, South Africa.

As a historic gold mining area, the City of Benoni has numerous water bodies close to major tailings dams and mine dumps. Here we assess spatial patterns in the sediment geochemistry of five dams and four natural pans within a 5-km radius of the core mining area to determine the degree of contamination7 by mining-associated pollutants. XRF analysis was used with a geoaccumulation index to assess the degree of contamination above background levels. Prevailing winds blow from the north and north-west with less dominant winds from the east. Sediment concentrations of As, Cu, Pb, Ni and Zn are highly correlated across the region, suggestive of a common source. Except for one pan showing evidence of local industrial pollution, the most contaminated sites are the dams to the west of the mine dumps where concentrations of As, Cu, Pb and Zn increase towards the central mining area, with highest trace metal concentrations in Kleinfontein Dam, adjacent to a reworked mine dump. Sites upwind of the central mining area showed little evidence of mining-related contamination. Trace contaminant concentrations in sediments of these dams are much greater than those found in the nearby Springs-Blesbokspruit wetlands adjacent to more recently active mines. The potential risks to aquatic ecosystems and recreational users of these urban and suburban water bodies from these wind-blown, legacy mining contaminants merit further investigation.

British Neuropathological Society and International Society of Forensic Radiology and Imaging expert consensus statement for post mortem neurological imaging.

AIMS: To develop an expert consensus statement regarding appropriate clinical and forensic post mortem neurological imaging. METHODS: An expert panel of clinicians were recruited from registered members of the British Neuropathological Society (BNS) and the International Society of Forensic Radiology and Imaging (ISFRI) with post mortem expertise. Following a focus group meeting, 16 core statements were incorporated into an online modified Delphi survey and each panellist was asked to score their level of agreement. Following the first iteration, two statements that failed to reach consensus were modified and re-rated. Consensus was predefined as 75% agreement across responders. RESULTS: Seventeen experts joined the panel and 12 (70.6%) attended the focus group meeting; 14 (82%) completed both iterations of the survey. Consensus was reached for need of adequate clinical history, multidisciplinary discussion, establishment of special interest groups to discuss cases, gathering further evidence to inform imaging choices, establishment of methods for quality assessment in reporting standards and adequate funding for imaging services. The panel agreed that pathologists should be responsible for neuroimaging referrals, collating results of ancillary tests, and producing the final post mortem report. Areas requiring further discussion include the impact of double reporting, indications for neuroimaging and utilities of three-dimensional printing. CONCLUSION: The BNS/ISFRI statement represents current views of an expert panel of health professionals engaged in post-mortem neuroimaging. We hope this provides a working guideline for less experienced operators, stimulates discussion and highlights the most pressing clinical and research questions.

A tale of two kidneys, and the case for machine perfusion in South Africa.

Extended-criteria donors (ECDs) are seen as a means of addressing the shortfall in solid-organ availability for transplant. However, the use of ECD kidneys is associated with a greater risk of primary non-function compared with standard-criteria donor kidneys, and a higher discard rate has been described internationally. There seems to be a lack of consensus in the consideration of ECD kidneys for transplant, with reliance often placed on the subjective assessment of individual clinicians. The following case examines the difference in the institutional decision-making process applied to two kidneys from a single donor, and provides an argument for the use of hypothermic machine perfusion in low- to middle-income countries as an efficacious and objective means of assessing ECD kidney suitability.

Dumbbell ganglioneuroma mimicking lumbar neurofibroma: a case report and review of the literature.

Spinal ganglioneuromas may grow in a dumbbell fashion. We report the first case of an intradural, extramedullary ganglioneuroma in the lumbar spine and review the pertinent literature. Although rare, we propose that ganglioneuroma be considered a differential diagnosis in patients presenting with a large mass occupying both intraspinal and extraspinal compartments.

Novel POLG1 mutations associated with neuromuscular and liver phenotypes in adults and children.

BACKGROUND: The POLG1 gene encodes the catalytic subunit of DNA polymerase gamma, essential for mitochondrial DNA replication and repair. Mutations in POLG1 have been linked to a spectrum of clinical phenotypes, and may account for up to 25% of all adult presentations of mitochondrial disease. METHODS AND RESULTS: We present 14 patients, with characteristic features of mitochondrial disease including progressive external ophthalmoplegia (PEO) and Alpers-Huttenlocher syndrome and laboratory findings indicative of mitochondrial dysfunction, including cytochrome c oxidase (COX) deficiency and multiple deletions or depletion of the mitochondrial DNA. Four novel POLG1 missense substitutions (p.R597W, p.L605R, p.G746S, p.A862T), are described, together with the first adult patient with a recently described polymerase domain mutation (p.R1047W). All novel changes were rare in a control population and affected highly conserved amino acids. CONCLUSION: The addition of these substitutions-including the first report of a dinucleotide mutation (c.1814_1815TT>GC)-to the growing list of defects further confirms the importance of POLG1 mutations as the underlying abnormality in a range of neurological presentations.

Endoscopic transsphenoidal surgery for isolated fibrous dysplasia of the clivus.

INTRODUCTION: Fibrous dysplasia is a non-neoplastic disorder of bone, related to abnormal proliferation of fibro-blasts. CASE REPORT: We report a 41-year-old female who presented with hyperprolactinaemia and an incidental clival lesion on MR scan. This was sub-totally resected via an endoscopic transsphenoidal approach and fibrous dysplasia was confirmed histologically. Her postoperative re-covery was un-eventful and at 8 months follow-up, she remains well, other than for the intermittent headaches and with no pituitary hormone deficiencies. CONCLUSION: The present case highlights the need to consider fibrous dysplasia in the differential diagnosis of isolated clival lesions.

No relationship between 18F-fluorodeoxyglucose positron emission tomography and expression of Glut-1 and -3 and hexokinase I and II in high-grade glioma.

The purpose of this study was to compare glucose metabolism, measured using 18F-fluorodeoxyglucose positron emission tomography ([18F]FDG-PET), with the expression of Glut-1 and -3 and hexokinase I (Hex I) and II in high-grade glioma. The retrospective study involved 27 patients with WHO classification grade III and IV glioma, with either newly diagnosed or recurrent tumours. Patients underwent dynamic and static [18F]FDG-PET to glucose metabolic rate (MRGlu) and standardised uptake value (SUV), respectively. Tumour biopsies were obtained and stained using immunohistochemistry for the expression of Glut-1, -3, Hex I and II. Relationships between variables were studied using Spearman's rank correlation test. Results showed that the expression of Glut-1, Glut-3, Hex I and Hex II varied between and within the tumour samples. The mean of MRGlu was 0.2 (range 0.09-0.25) micromol/min/ml and that of SUV was 4.2 (range 3.2-5.2). There were no significant relationships among the tumour expression of any of the proteins studied with either MRGlu or SUV (p>0.21 for all). In conclusion, the lack of relationship between the immunohistochemical expression of Glut-1, -3, Hex I or II and glucose metabolism measured using [18F]FDG-PET in patients with high-grade glioma may be due to the tissue heterogeneity and presence of necrosis in high-grade tumours.

Phenotypic similarities causing clinical misdiagnosis of pathologically-confirmed sporadic Creutzfeldt-Jakob disease as dementia with Lewy bodies.

A patient fulfilling central, core and supportive clinical diagnostic criteria for dementia with Lewy bodies deteriorated rapidly in the absence of neuroleptic drug treatment, prompting suspicion of a diagnosis of sporadic Creutzfeldt-Jakob disease. At postmortem examination, the brain showed features typical of Creutzfeldt-Jakob disease of the MV1 subtype. We review the phenotypic overlap between dementia with Lewy bodies and Creutzfeldt-Jakob disease which may cause clinical misdiagnosis.

Enterogenous cysts of the cerebellopontine angle: short review illustrated by two new patients.

Intracranial enterogenous cysts are an uncommon entity rarely found in the midline within the posterior cranial fossa. The occurrence of an enterogenous cyst in the cerebellopontine angle is exceptional. We present two new cases of cerebellopontine angle (CPA) enterogenous cysts and review the literature to clarify the diagnosis and the management of these lesions. Eighteen cases of CPA intradural enterogenous cysts have been reported to date, including the two cases presented in this article. All of them were symptomatic and underwent surgical treatment. After surgery, the symptomatic recurrence occurred in 31% of the patients, most of which had partial excision. Considering our patients and the published cases in the literature we suggest that the aim of surgery should be total removal of cyst and its content whenever possible. When partial resection of the cyst is performed, we recommend long-term clinical and neuroradiological follow-up.

Dumbbell-shaped intrathoracic-extradural haemangioma of the thoracic spine.

Spinal haemangiomas are benign vasoproliferative lesions that are typically intra-osseous and generally asymptomatic, although localized pain can be a symptom. Capillary and cavernous variants have been described. We describe a rare case of a dumbbell-shaped haemangioma of the thoracic spine with both an intraspinal-extradural and intrathoracic component.

Mitotic Activity in Glioblastoma Correlates with Estimated Extravascular Extracellular Space Derived from Dynamic Contrast-Enhanced MR Imaging.

BACKGROUND AND PURPOSE: A number of parameters derived from dynamic contrast-enhanced MR imaging and separate histologic features have been identified as potential prognosticators in high-grade glioma. This study evaluated the relationships between dynamic contrast-enhanced MRI-derived parameters and histologic features in glioblastoma multiforme. MATERIALS AND METHODS: Twenty-eight patients with newly presenting glioblastoma multiforme underwent preoperative imaging (conventional imaging and T1 dynamic contrast-enhanced MRI). Parametric maps of the initial area under the contrast agent concentration curve, contrast transfer coefficient, estimate of volume of the extravascular extracellular space, and estimate of blood plasma volume were generated, and the enhancing fraction was calculated. Surgical specimens were used to assess subtype and were graded (World Health Organization classification system) and were assessed for necrosis, cell density, cellular atypia, mitotic activity, and overall vascularity scores. Quantitative assessment of endothelial surface area, vascular surface area, and a vascular profile count were made by using CD34 immunostaining. The relationships between MR imaging parameters and histopathologic features were examined. RESULTS: High values of contrast transfer coefficient were associated with the presence of frank necrosis (P = .005). High values of the estimate of volume of the extravascular extracellular space were associated with a fibrillary histologic pattern (P < .01) and with increased mitotic activity (P < .05). No relationship was found between mitotic activity and histologic pattern, suggesting that the correlation between the estimate of volume of the extravascular extracellular space and mitotic activity was independent of the histologic pattern. CONCLUSIONS: A correlation between the estimate of volume of the extravascular extracellular space and mitotic activity is reported. Further work is warranted to establish how dynamic contrast-enhanced MRI parameters relate to more quantitative histologic measurements, including markers of proliferation and measures of vascular endothelial growth factor expression.

Serogroup-reactive and type-specific detection of bluetongue virus antibodies using chicken scFvs in inhibition ELISAs.

Two bluetongue virus (BTV) serotype 10-specific single-chain Fv chicken antibody fragments (scFvs) were evaluated in a competitive ELISA. The binding of one (F3) to purified BTV was only inhibited by antibodies against the homologous serotype. The binding of the other (F10) was blocked by antisera to each of the 24 BTV serotypes. F10 recognised VP7, a major structural protein of the BTV core, but not if the protein was directly adsorbed to a plastic surface. It did, however, bind to recombinant VP7 that had been captured from suspension by rabbit IgG. This made it possible to develop an scFv based inhibition ELISA for BTV antibodies using recombinant VP7 without prior purification. The resulting immunoassay detected antibodies to 24 BTV serotypes, but not those directed against three serotypes of the related epizootic haemorrhagic disease virus. A phage library displaying fusion peptides expressed by fragments of the BTV genome segment 7 cDNA was constructed and screened using F10. Comparing selected peptides with the amino acid sequence of VP7 showed that recognition by the scFv required at least 131 residues representing the protein's upper domain. By providing well-characterised immunological reagents, recombinant antibody technology can contribute to the development of improved immunoassays for BTV diagnosis.

Disseminated enteropathy-type T-cell lymphoma: cauda equina syndrome complicating coeliac disease.

A patient with coeliac disease developed a progressive cauda equina syndrome in the 2 months prior to his death, for which no cause could be identified. At post-mortem examination this proved to be due to disseminated enteropathy-type T-cell lymphoma. Although rare, disseminated enteropathy-type T-cell lymphoma should enter the differential diagnosis in any patient with coeliac disease developing new neurological signs.

Use of a gene-targeted phage display random epitope library to map an antigenic determinant on the bluetongue virus outer capsid protein VP5.

We describe the use of a gene-targeted random epitope library for the mapping of antigenic determinants. A DNA clone encoding the target antigen was digested randomly with DNase I to generate a population of DNA fragments of different sizes and sequences. After size fractionation, small DNA fragments (100-200 bp) were isolated and cloned into the phage expression vector fUSE2 to form an expression library displaying random polypeptide sequences as fusion proteins at the N terminus of the phage gene III protein. This library, termed a gene-targeted random epitope library to distinguish it from totally random synthetic epitope libraries, was then screened by affinity selection for recombinant phages which were specifically bound by the antibody of interest. Using this approach, we have mapped a monoclonal antibody (mAb)-defined epitope on the bluetongue virus outer capsid protein VP5. This epitope is not accessible on the intact virus surface, but is recognised by the immune system of sheep and cattle during virus infection. Although the example given here utilised a DNA fragment of known sequence and the library was screened for a mAb-defined epitope, the strategy described should be equally applicable to genes of unknown sequence and for screening of epitopes using polyclonal antibodies. The approach can also be extended to identify immunodominant epitope from much more complex genome-targeted random epitope library for virus, bacteria and eukaryotic organisms. Other applications of recombinant phages expressing defined immunodominant epitopes include serodiagnosis and vaccine development.

Demonstration of reinfection and reactivation in HIV-negative autopsied cases of secondary tuberculosis: multilesional genotyping of Mycobacterium tuberculosis utilizing IS 6110 and other repetitive element-based DNA fingerprinting.

SETTING: Secondary tuberculosis may follow reinfection or endogenous reactivation. The design of effective preventive and treatment protocols requires knowledge about the relative importance of these mechanisms in specific communities. Molecular typing of Mycobacterium tuberculosis has permitted linkage of cases and demonstration of patterns of inter- or intrapatient strain diversity correlating with reinfection and reactivation. OBJECTIVE: The use of DNA fingerprinting to examine intrapatient strain diversity in autopsied, HIV-negative individuals resident in a high incidence community. DESIGN: Autopsy (12 cases) and pneumonectomy (one case) permitted multilesional sampling for bacterial culture and comparative genotyping. Mycobacterium tuberculosis strains were typed using probes directed against IS 6110, the direct repeat sequence (DR) and MTB484(1). RESULTS: In two patients, the demonstration of pulmonary infection by two distinct strains suggested dual infection of these individuals. In one other case, the strain isolated from a Ghon-focus was identical to that obtained from all secondary cavitating lesions, which suggested reactivation of the primary infection. In the remaining cases, all isolates were identical, but primary lesions could not be identified with certainty or were culture negative. One of these cases showed evidence of strain evolution. CONCLUSIONS: Multilesional strain genotyping suggested both reinfection and reactivation in a series of HIV-negative autopsied patients with secondary tuberculosis. In most (11/13) cases, the same strain (or clonal variant) was present in all lesions, pulmonary and extrapulmonary.

Eliciting antigen-specific egg-yolk IgY with naked DNA.

Immunization with naked DNA was used to elicit chicken egg yolk antibodies (IgY). Layer hens were inoculated with plasmid DNA encoding the enhanced green fluorescent protein, the fusion protein of Newcastle disease virus, and VP2 of African horse sickness virus. IgY was extracted from egg yolks by polyethylene glycol precipitation. Specific antibodies were present in the yolks of eggs from hens immunized with each of the three different plasmids. This approach to raising polyclonal antibodies obviates the need to produce and purify large quantities of proteins for immunization and can potentially yield large amounts of diagnostically or therapeutically useful reagents.

Cowdria ruminantium antigens of around 15 kDa are potent inducers of IFN-gamma.

Cellular responses induced in two Creole goats by vaccination with killed Cowdria ruminantium (Cowdria) were confirmed by IFN-gamma production and interleukin-2 receptor (IL-2R) expression. Both CD4+ and CD8+ but not WC1+ T cells showed a substantial increase in cell surface expression of IL-2R molecules in response to whole Cowdria lysate. Cowdria (Welgevonden strain) proteins were fractionated using continuous-flow electrophoresis and tested for their ability to induce IFN-gamma production by PBMC collected three weeks after the first inoculation and one week after the booster injection. Pooled fractions of around 15, 22, and 24 kDa were found to induce significant IFN-gamma production in both vaccinated animals on one of the two occasions. Antigens of around 15 kDa induced substantially higher IFN-gamma production than any other fractions in both animals. These pilot experiments pave the way towards the identification of proteins/genes that have potential for the development of a recombinant vaccine against heartwater.

Cytokine levels affected by gamma-linolenic acid.

This study was undertaken to assess whether gamma-linolenic acid (GLA) in the form of evening primrose oil (EPO) could affect rat serum cytokines, interferon-gamma (IFN-gamma), monocyte chemotactic protein-1 (MCP-1) and tumour necrosis factor-alpha (TNF-alpha). The following diets were administered: control, glucan, Freund's adjuvant and glucan plus Freund's adjuvant with and without GLA. In the presence of GLA, the IFN-gamma and MCP-1 levels were significantly decreased in contrast to the control group of TNF-alpha, which was significantly stimulated. On account of interaction between diets and GLA, the remaining diet groups of TNF-alpha were either not affected or were inhibited in the presence of GLA. The observations indicate that GLA may modulate the level of serum IFN-gamma, MCP-1 and TNF-alpha, which may be a worthwhile line of treatment in certain human diseases.

Modulation of lipoxidase activity by urokinase-type plasminogen activator.

Malignant cells show increased urokinase (UK) activity and decreased peroxidation of essential fatty acids (EFA). In order to explore this phenomenon the effect of UK on the lipoxidase activity was spectrophotometrically investigated. Decreased lipoxidase activity was obtained with increased UK concentrations (r = -1.000, p < 0.0001). This proteolytic effect of UK on lipoxidase was eliminated with the addition of the UK inhibitor leupeptin. These results suggest that the increase in UK activity in malignant cells may decrease the lipoxidase activity and thus peroxidation of EFA. The effectiveness of a given EFA in killing cancer cells would therefore depend on the modulation of the lipoxidase activity by the UK-type plasminogen activator.

The effect of gamma-linolenic acid and eicosapentaenoic acid on urokinase activity.

Urokinase (UK) is an important protease enzyme in carcinogenesis, and is involved in the invasion and metastasis of cancer. Thus, regulation of UK activity is likely to be important in healthy cell metabolism. As it has been reported that a decrease in delta 6-desaturated essential fatty acid (EFA) metabolites occurs in malignant cells and that gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA) exert antimutagenic effects, the effects of GLA and EPA on UK activity have been investigated in this study. Both GLA (n-6) and EPA (n-3) acted as competitive inhibitors of UK with Ki values of 120 and 96 microM respectively. No modification of plasmin activity occurred with either 1.4 x 10(-4) M GLA or EPA. These results could explain why malignant cells with decreased EFA concentrations show increased UK activity. The addition of EFAs to available therapeutic regimens may be worth considering in the treatment of cancer.