Jupiter's X-Ray and UV Dark Polar Region

We present 14 simultaneous Chandra X-ray Observatory (CXO)-Hubble Space Telescope (HST) observations of Jupiter's Northern X-ray and ultraviolet (UV) aurorae from 2016 to 2019. Despite the variety of dynamic UV and X-ray auroral structures, one region is conspicuous by its persistent absence of emission: the dark polar region (DPR). Previous HST observations have shown that very little UV emission is produced by the DPR. We find that the DPR also produces very few X-ray photons. For all 14 observations, the low level of X-ray emission from the DPR is consistent (within 2-standard deviations) with scattered solar emission and/or photons spread by Chandra's Point Spread Function from known X-ray-bright regions. We therefore conclude that for these 14 observations the DPR produced no statistically significant detectable X-ray signature.

Planned combined onco-plastic (COP) surgical approach improves oncologic outcomes in soft tissue sarcomas

BACKGROUND

Combined modality of radiotherapy and surgery is the standard of treatment of soft tissue sarcomas (STS). The goal of this study was to assess whether a Combined Onco-Plastic (COP) surgical approach in the setting of neo-adjuvant radiotherapy can improve the oncologic outcomes of STS and reduce the rate of wound complications.

METHODS

We performed a retrospective review of all patients with STS treated at a single sarcoma centre (St Vincent's Hospital, Melbourne) between 2007 and 2018. Patients were stratified into two groups based on whether they have received the COP approach or were closed primarily by the orthopaedic surgeon. We analysed oncological outcomes and rate of wound complications.

RESULTS

A total of 546 patients with comparable demographics and tumor characteristics were included. The COP approach was performed in 75.6% of the patients. Wide margins were obtained in 97.4% of the cases, and this was significantly higher in the COP group (p < 0.001). The cumulative rate of local recurrence was 4.9%, with a 52% risk reduction in the COP approach, although this reduction was not significant (HR = 0.48; 95% CI 0.21-1.06; p = 0.070). The COP approach had better disease free survival (DFS) (aHR 1.86, 95% CI 1.45-2.37; p < 0.001) and Overall survival (risk of death aHR 0.49; 95% CI 0.30-0.79; p = 0.004). The overall wound complication rate was 18.6% with no difference between the two groups.

CONCLUSION

A planned collaboration between the orthopaedic oncologist and the plastic surgeon is beneficial in the treatment of STS after neo-adjuvant radiotherapy, allowing remarkably good oncological outcomes and a low rate of wound complications.

Accuracy of methods for reporting inorganic element concentrations and radioactivity in oil and gas wastewaters from the Appalachian Basin, U.S. based on an inter-laboratory comparison

Accurate and precise analyses of oil and gas (O&G) wastewaters and solids (e.g., sediments and sludge) are important for the regulatory monitoring of O&G development and tracing potential O&G contamination in the environment. In this study, 15 laboratories participated in an inter-laboratory comparison on the chemical characterization of three O&G wastewaters from the Appalachian Basin and four solids impacted by O&G development, with the goal of evaluating the quality of data and the accuracy of measurements for various analytes of concern. Using a variety of different methods, analytes in the wastewaters with high concentrations (i.e., >5 mg L-1) were easily detectable with relatively high accuracy, often within ±10% of the most probable value (MPV). In contrast, often less than 7 of the 15 labs were able to report detectable trace metal(loid) concentrations (i.e., Cr, Ni, Cu, Zn, As, and Pb) with accuracies of approximately ±40%. Despite most labs using inductively coupled plasma mass spectrometry (ICP-MS) with low instrument detection capabilities for trace metal analyses, large dilution factors during sample preparation and low trace metal concentrations in the wastewaters limited the number of quantifiable determinations and likely influenced analytical accuracy. In contrast, all the labs measuring Ra in the wastewaters were able to report detectable concentrations using a variety of methods including gamma spectroscopy and wet chemical approaches following Environmental Protection Agency (EPA) standard methods. However, the reported radium activities were often greater than ±30% different to the MPV possibly due to calibration inconsistencies among labs, radon leakage, or failing to correct for self-attenuation. Reported radium activities in solid materials had less variability (±20% from MPV) but accuracy could likely be improved by using certified radium standards and accounting for self-attenuation that results from matrix interferences or a density difference between the calibration standard and the unknown sample. This inter-laboratory comparison illustrates that numerous methods can be used to measure major cation, minor cation, and anion concentrations in O&G wastewaters with relatively high accuracy while trace metal(loid) and radioactivity analyses in liquids may often be over ±20% different from the MPV.

Quantitation of lead-210 (210Pb) using lead-203 (203Pb) as a "Massless" yield tracer

Determination of Pb-210 (²¹⁰Pb) in aqueous solution is a common radioanalytical challenge in environmental science. Widely used methods for undertaking these analyses (e.g., ASTM D7535) rely on the use of stable lead (Pb) as a yield tracer that takes into account losses of ²¹⁰Pb that inevitably occur during elemental/radiochemical separations of the procedures. Although effective, these methods introduce technical challenges that can be difficult to track and potentially introduce uncertainty that can be difficult to quantify. Examples of these challenges include interference from endogenous stable Pb in complex sample matrices; contamination of stable Pb carrier with ²¹⁰Pb; and high detection limits due to counting efficiency limitations. We hypothesized that many of these challenges could be avoided by the use of the electron-capture, gamma-emitting isotope, ²⁰³Pb as a chemical yield tracer in the analysis of ²¹⁰Pb. A series of experiments were performed to evaluate the efficacy of ²⁰³Pb as a tracer. Four different matrices were analyzed, including a complex matrix (hydraulic-fracturing produced fluids); and samples comprising less complicated matrices (i.e., river water, deionized water, and tap water). Separation techniques and counting methodologies were also compared and optimized. Due to a relatively short-half life (52 h), ²⁰³Pb tracer is effectively massless for the purposes of chemical separations, allowing for reduced chromatography column resin bed volumes. Because ²⁰³Pb is a gamma emitter (279 keV; 81% intensity), recovery can be determined non-destructively in a variety of matrices, including liquid scintillation cocktail. The use of liquid scintillation as a counting methodology allowed for determination of ²¹⁰Pb activities via ²¹⁰Pb or ²¹⁰Po; and recoveries of greater than 90% are routinely achievable using this approach. The improved method for the analysis of ²¹⁰Pb in aqueous matrices allows for the analysis of complex matrices, at reduced cost, while providing greater counting flexibility in achieving acceptable detections limits.

Polonium-210 accumulates in a lake receiving coal mine discharges-anthropogenic or natural?

Coal is an integral part of global energy production; however, coal mining is associated with numerous environmental health impacts. It is well documented that coal-mine waste can contaminate the environment with naturally-occurring radionuclides from the uranium-238 (²³⁸U) decay series. However, the behavior of the final radionuclide in the ²³⁸U-series, i.e., polonium-210 (²¹⁰Po) arising from coal-mine waste-water discharge is largely unexplored. Here, results of a year-long (2014-2015) field study, in which the concentrations of ²¹⁰Po in sediments and surface water of a lake that receives coal-mine waste-water discharge in West Virginia are presented. Initial measurements identified levels of ²¹⁰Po in the lake sediments that were in excess of that which could be attributed to ambient U-series parent radionuclides; and were indicative of discharge site contamination of the lake ecosystem. However, control sediment obtained from a similar lake system in Iowa (an area with no coal mining or unconventional drilling) suggests that the levels of ²¹⁰Po in the lake are a natural phenomenon; and are likely unrelated to waste-water treatment discharges. Elevated levels of ²¹⁰Po have been reported in lake bottom sediments previously, yet very little information is available on the radioecological implications of ²¹⁰Po accumulation in lake bottom sediments. The findings of this study suggest that (Monthly Energy Review, 2016) the natural accumulation and retention of ²¹⁰Po in lake sediments may be a greater than previously considered (Chadwick et al., 2013) careful selection of control sites is important to prevent the inappropriate attribution of elevated levels of NORM in lake bottom ecosystems to industrial sources; and (Van Hook, 1979) further investigation of the source-terms and potential impacts on elevated ²¹⁰Po in lake-sediment ecosystems is warranted.

Infective complications following tumour endoprosthesis surgery for bone and soft tissue tumours

AIMS

This study aims to describe the incidence of infective complications, including tumour endoprosthesis infection, in a cohort of patients undergoing tumour endoprosthesis surgery in Victoria, Australia.

METHODS

This retrospective cohort study was performed over 15 years (January 1996-December 2010).

RESULTS

121 patients underwent tumour endoprosthesis surgery during the study period. Patients were followed for a median of 34 months (interquartile range [IQR] 17, 80). Overall, 34 patients (28%) experienced infective complications including: bacteraemia in 19 patients (16%) and tumour endoprosthesis infection in 17 (14%). The majority of patients with early and late acute infections (haematogenous) were managed with debridement and retention of the prosthesis in addition to biofilm-active antibiotics. Late chronic infections were predominantly managed by exchange of the prosthesis. The overall success rate of treatment was 71%. The success rate for debridement and retention was 75% compared with 67% for exchange procedures.

CONCLUSIONS

There is a significant rate of infective complications following tumour endoprosthesis surgery including 14% of patients experiencing infection involving the tumour endoprosthesis. This study is the first to report on outcomes from debridement and retention of the prosthesis; which had comparable success rates to other treatment modalities.

Effects of egg shell quality and washing on Salmonella Infantis penetration

The vast majority of eggs in Australia are washed prior to packing to remove dirt and fecal material and to reduce the microbial contamination of the egg shell. The egg contents can be an ideal growth medium for microorganisms which can result in human illness if eggs are stored improperly and eaten raw or undercooked, and it is estimated that egg-related salmonellosis is costing Australia $44 million per year. Egg shell characteristics such as shell thickness, amount of cuticle present, and thickness of individual egg shell layers can affect the ease with which bacteria can penetrate the egg shell and washing could partially or completely remove the cuticle layer. The current study was conducted to investigate the effects of egg washing on cuticle cover and effects of egg shell quality and cuticle cover on Salmonella Infantis penetration of the egg shell. A higher incidence of unfavorable ultrastructural variables of the mammillary layer such as late fusion, type B bodies, type A bodies, poor cap quality, alignment, depression, erosion and cubics were recorded in Salmonella penetrated areas of egg shells. The influence of egg washing on the ability of Salmonella Infantis on the egg shell surface to enter the egg internal contents was also investigated using culture-based agar egg penetration and real-time qPCR based experiments. The results from the current study indicate that washing affected cuticle cover. There were no significant differences in Salmonella Infantis penetration of washed or unwashed eggs. Egg shell translucency may have effects on Salmonella Infantis penetration of the egg shell. The qPCR assay was more sensitive for detection of Salmonella Infantis from egg shell wash and internal contents than traditional microbiological methods. The agar egg and whole egg inoculation experiments indicated that Salmonella Infantis penetrated the egg shells. Egg washing not only can be highly effective at removing Salmonella Infantis from the egg shell surface, but also allows subsequent trans-shell and trans-membrane penetration into the egg. Consequently, it is important to prevent recontamination of the egg after washing.

Ablation of connexin30 in transgenic mice alters expression patterns of connexin26 and connexin32 in glial cells and leptomeninges

Expression of connexin26 (Cx26), Cx30 and Cx43 in astrocytes and expression of Cx29, Cx32 and Cx47 in oligodendrocytes of adult rodent brain has been well documented, as has the interdependence of connexin expression patterns of macroglial cells in Cx32- and Cx47-knockout mice. To investigate this interdependence further, we examined immunofluorescence labelling of glial connexins in transgenic Cx30 null mice. Ablation of astrocytic Cx30, confirmed by the absence of immunolabelling for this connexin in all brain regions, resulted in the loss of its coupling partner Cx32 on the oligodendrocyte side of astrocyte-oligodendrocyte (A/O) gap junctions, but had no effect on the localization of astrocytic Cx43 and oligodendrocytic Cx47 at these junctions or on the distribution of Cx32 along myelinated fibres. Surprisingly, gene deletion of Cx30 led to the near total elimination of immunofluorescence labelling for Cx26 in all leptomeningeal tissues covering brain surfaces as well as in astrocytes of brain parenchyma. Moreover northern blot analysis revealed downregulation of Cx26 mRNA in Cx30-knockout brains. Our results support earlier observations on the interdependency of Cx30/Cx32 targeting to A/O gap junctions and further suggest that Cx26 mRNA expression is affected by Cx30 gene expression. In addition, Cx30 protein may be required for co-stabilization of gap junctions or for co-trafficking in cells.

Buttock cellulitis as a presentation of psoas abscess: a clinical reminder

Cellulitis is a common condition that is frequently managed by the general physicians on an acute medical take. This case report describes buttock cellulitis as a presentation of an iliopsoas abscess and illustrates the importance of considering a deep abscess when there are atypical features, when the cellulitis is in an unusual location or when the patient fails to improve with standard anti-microbial therapy.

Comparison of artificial neural network and regression models in the prediction of urban stormwater quality

Urban stormwater quality is influenced by many interrelated processes. However, the site-specific nature of these complex processes makes stormwater quality difficult to predict using physically based process models. This has resulted in the need for more empirical techniques. In this study, artificial neural networks (ANN) were used to model urban stormwater quality. A total of 5 different constituents were analyzed-chemical oxygen demand, lead, suspended solids, total Kjeldahl nitrogen, and total phosphorus. Input variables were selected using stepwise linear regression models, calibrated on logarithmically transformed data. Artificial neural networks models were then developed and compared with the regression models. The results from the analyses indicate that multiple linear regression models were more applicable for predicting urban stormwater quality than ANN models.

Evolution and diversity of subduction zones controlled by slab width

Subducting slabs provide the main driving force for plate motion and flow in the Earth's mantle, and geodynamic, seismic and geochemical studies offer insight into slab dynamics and subduction-induced flow. Most previous geodynamic studies treat subduction zones as either infinite in trench-parallel extent (that is, two-dimensional) or finite in width but fixed in space. Subduction zones and their associated slabs are, however, limited in lateral extent (250-7,400 km) and their three-dimensional geometry evolves over time. Here we show that slab width controls two first-order features of plate tectonics-the curvature of subduction zones and their tendency to retreat backwards with time. Using three-dimensional numerical simulations of free subduction, we show that trench migration rate is inversely related to slab width and depends on proximity to a lateral slab edge. These results are consistent with retreat velocities observed globally, with maximum velocities (6-16 cm yr(-1)) only observed close to slab edges (<1,200 km), whereas far from edges (>2,000 km) retreat velocities are always slow (<2.0 cm yr(-1)). Models with narrow slabs (< or =1,500 km) retreat fast and develop a curved geometry, concave towards the mantle wedge side. Models with slabs intermediate in width ( approximately 2,000-3,000 km) are sublinear and retreat more slowly. Models with wide slabs (> or =4,000 km) are nearly stationary in the centre and develop a convex geometry, whereas trench retreat increases towards concave-shaped edges. Additionally, we identify periods (5-10 Myr) of slow trench advance at the centre of wide slabs. Such wide-slab behaviour may explain mountain building in the central Andes, as being a consequence of its tectonic setting, far from slab edges.

Mutational effects of retrovirus insertion on the genome of V79 cells by an attenuated retrovirus vector: implications for gene therapy

Attenuated retroviruses are currently the most widely used vectors in clinical gene therapy because of their potential to effect stable and permanent gene transfer. Since gene delivery is accompanied by random insertion of foreign genetic material into the recipient chromosomal DNA, the potential for insertional mutagenesis exists. In this study, we used a defective retrovirus vector containing a selectable marker, the hygromycin phosphotransferase gene, to investigate the mutagenic effects of vector integration on the mammalian genome. V79 Chinese hamster cells were infected with virus supernatants or by coculture with virus producer cells, and provirus insertion events occurred at low and high frequencies, respectively. The frequency of hprt mutagenesis was increased by a factor of 2.3 over the spontaneous hprt mutation frequency only following multiple provirus insertions/cell genome. Multiple provirus insertions (>3/genome) resulted in instability at the hprt locus in 63% of the virally induced hprt mutants, as indicated by rearrangements at the molecular level, whereas no rearrangements were found when the provirus copy number was 1-2/genome. To demonstrate direct proviral involvement in mutagenesis, the defective MLV vector was retrieved along with flanking genomic hprt sequences from one mutant, and localized within intron 5 of the hprt gene. These data suggest that provirus copy number is a key factor when considering the potential hazards of using retrovirus vectors for gene therapy.

Occipital condyle fractures in children. Case report and review of the literature

Occipital condyle fractures (OCF) are seldom described in children, with only 14 cases reported in the literature. We report the observation of a 13-year-old child in whom such a fracture was diagnosed. A review of the paediatric cases allowed us to identify the clinical features of OCF in children. The average age was found to be 10 years, and the causative traumatism was most often related to road traffic or sporting accidents with associated head injury. The level of consciousness was depressed in 67% of the cases, and in 53%, an injury to the cranial nerves, brain stem or high spinal cord was present. Neck pain with reduction of head mobility was reported in 27% of the cases. Treatment was generally conservative, i.e. a hard collar or halo vest for an average of 8 weeks. The course was favourable with respect to osseous consolidation, mobility and pain. On the other hand, the neurological deficits improved, but sequelae remained. Early diagnosis and treatment is mandatory since the secondary displacement of fractured fragments can injure the cranial nerves in a delayed fashion or even be fatal due to compression of the brain stem.

Idiopathic symptomatic epidural lipomatosis of the lumbar spine

BACKGROUND

Symptomatic spinal epidural lipomatosis (SEL) of the lumbar spine is a rare disease, often associated with steroid overload. Idiopathic lipomatosis is even much less frequent. Signs and symptoms depend upon the level and degree of nerve root compression. Diagnosis is best based on MRI. Weight reduction can be curative, however after failure of medical treatment or in severe cases surgical decompression should be performed.

METHOD

Four patients with severe symptoms of lumbar spinal epidural lipomatosis were treated by surgical decompression. Patient history and neurological examination are described, diagnostic imaging is demonstrated, surgical treatment and outcome are documented. Different surgical techniques including laminectomy, interlaminar fenestration and lateral recess decompression were applied and are discussed.

FINDINGS

All four patients improved after surgery. No surgical complications were observed. Even though limited to four cases this is the second largest series of operated idiopathic spinal epidural lipomatosis.

INTERPRETATION

Surgical decompression was effective in improving symptoms in severe lumbar idiopathic spinal epidural lipomatosis.

Measuring the outputs of nursing research and development in Australia: the researchers

It is vital for nurses to publish in order to provide evidence of their practice and to increase the knowledge base of their discipline. This paper is one of two that reports on an investigation of the nursing research published by Australian authors from 1995-2000 in 11 nursing journals based in Australia, the UK and the USA. The focus of this article is on the researchers drawn from a total of 509 articles that were content analysed and categorised according to topics of research, paradigm, methods used and funding acknowledgment. The researchers were analysed on the basis of gender, discipline, employment base and location. Publications had from one to 10 authors, averaging two, with 26 authors claiming 23.6% of research articles. The most common discipline area was nursing and universities were the leading area of employment. Authorship was not limited to capital cities reflecting the spread of university campuses in rural areas. Research papers made up 12.5% of possible articles, supporting the notion that few nurses publish research papers in the refereed general nursing journals we focused on.

[Transthoracic transvertebral approach for resection of an anteriorly located, calcified meningioma. Case report]

We report the case of a 61-year-old woman, who developed progressive paraparesia over a period of 8 months. Conventional X-rays of the thoracic spine showed an intra-spinal calcified lesion at T10. On CT-scan and MRI, the lesion appeared anterior to the cord, thus making a posterior approach hazardous. Total resection of this calcified meningioma was achieved through a right transthoracic transcorporeal approach, under close monitoring of the somatosensory evoked potentials. Despite a delayed pseudomeningocele formation requiring an additional thoracotomy, outcome after 7 years is excellent with no residual neurological deficit. No recurrence was seen on a CT-scan performed two years after the surgery. Calcified anterior meningiomas of the spine are rare lesions. Surgical outcome has been unfavorable for a long time in relation with posterior or postero-lateral approaches. Although anterior transthoracic procedures are routinely performed for extradural spinal lesions, this approach is rarely used for intradural lesions. A calcified anterior spinal thoracic meningioma should be managed like the more frequent calcified thoracic disk hernia, despite the increased risk of cerebrospinal fluid effusion requiring subsequent repair.

An open-label trial of tomoxetine in pediatric attention deficit hyperactivity disorder

OBJECTIVE

To collect pilot data assessing the safety, tolerability, and efficacy of tomoxetine, a nonstimulant norepinephrine enhancer, in pediatric attention deficit hyperactivity disorder (ADHD).

METHODS

An open-label trial of tomoxetine in pediatric ADHD was conducted as part of a multisite clinical trial. Following a baseline assessment, an ascending dose titration was completed during 10 weekly visits.

RESULTS

Ten subjects were enrolled at baseline, with eight completing the study. Seven of the eight remaining subjects met efficacy criteria. Significant decreases in symptom severity ratings by parents and study investigators were found. The medication was well tolerated, with transient appetite suppression the most frequently reported side effect. However, subjects' weights remained stable across study visits.

DISCUSSION

These preliminary findings suggest that tomoxetine may hold promise as a treatment for pediatric ADHD.

Biomechanical comparison of ankle arthrodesis techniques: crossed screws vs. blade plate

Many different techniques for ankle arthrodesis have been described. Experience at our institution with crossed screws internal fixation has not met the 90+% union rate reported in the literature. A compression blade plate is one technique for ankle arthrodesis which has not been evaluated biomechanically. A biomechanical study comparing two groups of sawbone ankle fusion constructs fixed with crossed screws and compression blade plates was performed in order to evaluate the stiffness and rigidity of these two arthrodesis techniques. The crossed screws construct demonstrated superior stiffness during dorsiflexion (p < 0.001) and valgus (p < 0.001) loading. The two constructs were found to have equal strength in resisting plantarflexion, varus and torsional loads although there was a trend for greater resistance by the crossed screws construct. These findings lend biomechanical support to the use of crossed screws for tibiotalar arthrodesis.

Molecular characterisation of a putative Atlantic salmon (Salmo salar) odorant receptor

The olfactory system of fish is extremely important as it is able to recognise and distinguish a vast array of odorous molecules that are involved in behaviours paramount to survival. This is achieved by the activation of a diverse multigene family of G-protein coupled receptors through odorous ligand binding. Using molecular techniques, the nucleotide sequence of the cDNA coding for an Atlantic salmon (Salmo salar) odorant receptor (ASOR1) has been determined. The full-length cDNA (1260 nt) encodes a protein of 320 amino acid residues, including one potential N-linked glycosylation site, within the short extracellular amino terminal of the receptor. Hydrophobicity analysis revealed seven hydrophobic regions within the amino acid sequence, corresponding to possible positions of the transmembrane domains characteristic of the G-protein coupled receptor superfamily. Several conserved motifs unique to odorant receptors were also present. Through characterisation of this receptor, we hope to increase the understanding of the mechanisms underlying olfaction in salmonid species.

Assessing cerebrospinal fluid rhinorrhea: a two-dimensional electrophoresis approach

Assessment of nasal cerebrospinal fluid (CSF) fistula commonly relies on the determination of CSF markers in an aqueous rhinorrhea, such as the beta2-transferrin immunofixation assay. While generally reliable, false positive and false negative results have been reported for most of the laboratory tests yet available. Based on the hypothesis that the simultaneous assessment of several CSF markers may yield an increased sensitivity and specificity, we used a proteomics, two-dimensional electrophoresis 2-DE based approach to study samples of nasal secretions obtained from 18 patients suspected of CSF rhinorrhea. Since CSF, nasal mucus and plasma may coexist in the nasal cavities, we first defined five specific markers for each of these biological fluids (transferrin, prostaglandin-D synthase, transthyretin, and two unknown trains of spots for CSF, immunoglobulin A (IgA) S-chain, lipocortin-1, lipocalin-1, prolactine-inducible protein and palatal lung nasal epithelium clone protein for mucus, haptoglobin alpha1/2- and beta-chains, fibrinogen alpha-, beta- and gamma-chains for plasma). Gels from the rhinorrhea patients were then compared to these 2-DE reference maps to determine the presence or absence of the defined markers, and clinical data were independently compared to the results of the 2-DE study. In all cases, the biological fluid(s) anticipated to be present in the nasal secretions based on clinical data were correctly identified by 2-DE. Moreover, an excellent correlation was found in nine patients who underwent extensive workup for suspected CSF rhinorrhea, since CSF was found by the 2-DE method in four patients in whom a CSF fistula was confirmed, whereas the test was negative in five patients in whom a CSF fistula was excluded. In the remaining patients, mucus, sometimes contamined with blood, was found to be the major component of the nasal secretions, confirming that clear mucus may mimick CSF rhinorrhea. These preliminary results suggest that a 2-DE-based multimarker approach is a valid, sensitive, and specific method to assess the presence of CSF in occult rhinorrhea.

Sharps injury: prevention and management

Nurses are at risk of infection through injuries caused by infected sharps and needles. The authors discuss the prevention and management of such injuries.

Threshold of fragmentation for ultrasonic contrast agents

Ultrasound contrast agents are small microbubbles that can be readily destroyed with sufficient acoustic pressure, typically, at a frequency in the low megaHertz range. Microvascular flow rate may be estimated by destroying the contrast agent in a vascular bed, and estimating the rate of flow of contrast agents back into the vascular bed. Characterization of contrast agent destruction provides important information for the design of this technique. In this paper, high-speed optical observation of an ultrasound contrast agent during acoustic insonation is performed. The resting diameter is shown to be a significant parameter in the prediction of microbubble destruction, with smaller diameters typically correlated with destruction. Pressure, center frequency, and transmission phase are each shown to have a significant effect on the fragmentation threshold. A linear prediction for the fragmentation threshold as a function of pressure, when normalized by the resting diameter, has a rate of change of 300 kPa/microm for the range of pressures from 310 to 1200 kPa, and a two-cycle excitation pulse with a center frequency of 2.25 MHz. A linear prediction for the fragmentation threshold as a function of frequency, when normalized by the resting diameter, has a rate of change of -1.2 MHz/microm for a transmission pressure of 800 kPa, and a two-cycle excitation pulse with a range of frequencies from 1 to 5 MHz.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Cutaneous manifestations in inflammatory bowel disease

Numerous extraintestinal manifestations in various organ systems have been reported to be associated with inflammatory bowel disease (IBD). Aim of the present paper was to evaluate the frequency of cutaneous manifestations in Crohn's disease (CD) and ulcerative colitis (UC) with respect to their location, the activity and location of the underlying disease, the treatment options and the time to remission.

METHODS

The medical records of 1043 inpatients with CD and UC were screened retrospectively for extraintestinal symptoms with special regard to cutaneous manifestations.

RESULTS

The prevalence of cutaneous manifestations in IBD was 22/1043 (2.1%; 18 women, 4 men; age: 31.41 +/- 9.9 [21-51] yrs.). In 15/22 patients (68.2%) the cutaneous manifestations were associated with CD, in 7/22 patients (31.8%) UC was confirmed. In 6/22 patients (27.3%) pyoderma gangrenosum (PG) was diagnosed, in 16/22 patients (72.7%) erythema nodosum (EN). EN and PG predominately occurred at the lower legs: in 68.1% the tibia was the main affection site. Other locations like breast or anus were rare. In 16/22 patients (72.7%) an acute phase of the underlying disease was evident, in 6/22 patients (27.3%) CD or UC were in remission. In patients with CD a colonic involvement was found in 86.7%. Arthritis was the most frequent coexisting extraintestinal manifestation in CD (53.3%) and UC (28.8%). Drug treatment was performed with high doses of glucocorticoids and salicylates. The time to remission in patients with EN was significantly shorter as compared to PG (5.3 +/- 1.8 vs. 19.6 +/- 14.2 weeks; p < 0.001). In 5/22 patients (22.7%) cutaneous manifestations reoccurred after a symptom-free interval. All efflorescenses reoccurred during an active phase of the underlying disease at the same manifestation site as the initial presentation.

CONCLUSION

In this series the prevalence of cutaneous manifestations in IBD was 22/1043 (2.1%). EN and PG were more frequent in women with IBD, in CD, and during the acute phases of the underlying disease. EN and PG predominately affect the lower legs. Cutaneous manifestations respond well to an acute phase therapy of the underlying disease. The time to remission was significantly shorter in EN as compared to PG. However, relapses have to be considered in a relevant subgroup of patients.

Cervical cord compression due to a hypoplastic atlas. Case report

The authors report the case of a 66-year-old man with progressive, nontraumatic, C-1 cord compression who presented with a complete but hypoplastic atlas. They review six cases found in the literature. Symptoms usually develop in the late adulthood; the sagittal diameter of the canal measures 10 mm or less. The treatment requires a posterior decompression. Opening of the dura is sometimes necessary. There is no pressing need for a primary stabilization device.

Molecular characterization of the first non-mammalian p73 cDNA

The p53 gene is believed to be mutated or deficient in over 50% of human tumours, and is therefore considered to be instrumental in the process of carcinogenesis. Recently in humans, homologues of p53 (such as p73 and p63) have been isolated. In our studies in fish, we have been isolating tumour suppressor genes with a view to their potential use to study genotoxins in the aquatic environment. In this paper, we report the characterisation of the first non-mammalian p73 cDNA, isolated from barbel (Barbus barbus), a freshwater cyprinid fish indigenous to UK rivers. The deduced barbel p73 amino acid sequence has a high homology with human p73 alpha: the proteins are 641 and 636 aa in length, respectively, and there is a 72% identity over the entire sequence length of the protein (over 90% in the putative DNA binding domain). The level of conservancy for p73 is considerably higher across class (from man to fish), than for p53 and it may therefore have particular value in studies on environmental mutagenesis. Northern analysis showed expression of three p73 mRNA transcripts/homologues. The patterns of p73 tissue expression in the barbel differed from the expression of p53 mRNA, suggesting specific functional roles for the two genes.

Infection control

Dee May looks at the prevalence and cost of hospital-acquired infection, how epidemiological changes have influenced the way infections are prevented and managed, and how, in practice, infection should be controlled.

Infection control must be the priority of all nurses

Two major reports have been published in recent weeks (Public Health Laboratory Service/London School of Hygiene and Tropical Medicine (PHLS/LSHTM), 1999; National Audit Office (NAO), 2000) which provide comprehensive data on the socioeconomic burden, management and control of hospitalacquired infection (HAI).

Continuity and change in the use of residential services by adults with intellectual disability: the Aberdeen cohort at mid-life

The present paper reports a follow-up study of a representative cohort of people with intellectual disability, now in middle age, who entered adult services on leaving school in the late 1960s, and whose adult years have coincided with a period of radical policy change and considerable service expansion. The present authors focus on the changes which have taken place in their use of residential services over this period. Firstly, the situation in early adulthood when they were last studied is examined. At this time, 60% of the cohort were still living at home, almost all with both parents. The remaining 40% were in institutions, mainly long-stay mental handicap hospitals. Out-of-home placement is associated with gender (maleness), challenging behaviour, and the absence of one or both parents. The present authors compare this with the situation 20 years later. The most significant change in this time is the expansion of the community sector, accounting for about half of the surviving cohort, with numbers still at home or in hospital correspondingly reduced. Almost half of the cohort had experienced little or no change in residential situation. On average, they were less intellectually and socially able than those who had moved into community provision.

PGP9.5: a marker for cellular neurothekeoma

Neurothekeomas are benign, predominantly cutaneous neoplasms that are divided histologically into myxoid, intermediate, and cellular types. Although it is generally agreed that the myxoid type of neurothekeoma has a neural origin, the lack of consistent immunoreactivity to neural markers and insufficient ultrastructural evidence of neural differentiation in cellular neurothekeoma have brought the origin of cellular neurothekeoma into question. In this report the authors show that immunoreactivity to protein gene product 9.5 (PGP9.5)--a broad neural marker--is positive in 100% of cases of cellular neurothekeoma using microwave antigen retrieval, as well as in all cases of myxoid and intermediate neurothekeoma. In contrast, immunoreactivity to S-100 protein is only positive in 3 of 12 cases of cellular neurothekeoma. These results show that PGP9.5 is a useful marker for identifying cellular neurothekeoma, as well as other types of neurothekeomas using the antigen retrieval method. The results are consistent with the notion that cellular neurothekeoma has a neural differentiation.

Determinants of the DNA-binding specificity of the Avian homeodomain protein, AKR

AKR (Avian Knotted-Related) was the first example of a vertebrate homeodomain protein with a highly divergent Ile residue at position 50 of the DNA-recognition helix. The protein was cloned from a liver cDNA expression library of a day-9 chick embryo by virtue of its ability to bind to the F' site in the proximal promoter of the avian apoVLDLII gene. Expression of the apoVLDLII gene is completely estrogen dependent, and mutation or deletion of the F' site decreases estrogen inducibility 5- to 10-fold. Subsequent data indicated that AKR is capable of repressing the hormone responsiveness of the apoVLDLII promoter, specifically through binding to F'. Involvement of the F' site in the hormone-dependent activation of apoVLDLII gene expression, as well as AKR-mediated repression, strongly suggests that both positive and negative regulatory factors interact with this site. Although several mammalian proteins have now been isolated whose homeodomains share many of the structural features of AKR, including the Ile at position 50, little is known of their functions in vivo or the identities of the genes they regulate. Consequently, the elements through which they exert their effects and the structural determinants of their binding specificities remain largely uncharacterized. In this study, we defined the sequence specificity of binding by AKR using polymerase chain reaction-assisted optimal site selection and determined the affinity with which the protein binds to both the optimized site and the F' site. Additionally, we generated a three-dimensional model of the AKR homeodomain binding to its optimized site and probed the validity of the model by examining the consequences of mutating amino acid residues in recognition helix 3 and the N-terminal arm on the binding specificity of the homeodomain. Finally, we present evidence that the F' site itself may act as an estrogen response element (ERE) when in the vicinity of imperfect or canonical EREs and that AKR can repress hormone inducibility mediated via this site.