Assessing the impact of wastewater treatment works effluent on downstream water quality.

The impact of wastewater treatment works (WwTW) effluent on downstream river water quality is of increasing concern, particularly owing to the presence in effluents of a range of trace substances. In the case of contamination by metals the question of bioavailability has recently been accounted for in setting water quality standards for several metals. In the UK over the past decade the Chemical Investigations Programme (CIP) has generated upstream and downstream river quality data as well as associated WwTW effluent monitoring for over 600 sites, for the main contaminants of regulatory interest under the Water Framework Directive. Data presented here show that at a local level WwTW discharges have little impact for many contaminants. Soluble reactive phosphorus, hexabromocyclododecane (HBCDD), cypermethrin, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have been shown to be the principal substances where downstream concentrations were at least 10 % larger than the upstream value. Otherwise, poor compliance with riverine water quality standards tends to be associated with contamination at the river catchment scale, with corresponding implications for the nature of remedial actions that are likely to be successful. Compliance with water quality criteria for metals, taking account of bioavailability, is high overall.

Summary of data from the UKWIR chemical investigations programme and a comparison of data from the past ten years' monitoring of effluent quality.

This paper reports summary data from a ten-year programme of investigation into the composition of wastewater treatment works' effluents in the UK. The so-called Chemical Investigations Programme focused on determinands of regulatory importance and involved monitoring of effluents for over seventy trace substances and sanitary determinands at more than 600 UK treatment works sites. The results provide a definitive overview of effluent quality. Although raw data are available, this publication of summary data provides a convenient résumé of the current state of knowledge. An analysis of changes in concentrations over the monitoring period between 2010 and 2020 shows that for several substances (nickel, diethylhexylphthalate, nonylphenol, tributyltin, the brominated diphenyl ethers and triclosan) significant reductions in wastewater concentration have occurred over the period of interest, these are likely to have resulted from a combination of tighter regulatory controls and/or improved wastewater treatment.

Perfluorinated alkyl substances: Sewage treatment and implications for receiving waters.

This study comprises a detailed analysis of data for perfluorooctanesulfonic acid (PFOS), and perfluorooctanoic acid (PFOA) for over 600 wastewater treatment works effluents (WwTW) as well as samples upstream and downstream of each discharge of effluent into its receiving water. This has allowed an investigation of not only the effectiveness of removal of the perfluoroalkyl substances (PFAS) compounds during wastewater treatment but also implications for compliance with the environmental quality standard (EQS) set for PFOS under the Water Framework Directive. It is shown that effluents contain concentrations of PFOS that exceed the annual average EQS by a factor between 1.1-fold and 40-fold. The corresponding factors for PFOA are between 2-fold and 22-fold. The presence of high concentrations upstream, means that between a quarter and a third of individual effluents are found to reduce the concentration of fluorocarbons in the river downstream of the discharge point. The elevated concentrations upstream of the studied wastewater treatment works suggest inputs of these perfluoro compounds into the aquatic environment are ubiquitous and therefore difficult to address from simply setting permit conditions for individual WwTW. The freshwater EQS set for PFOS is based on several worst-case accumulation coefficients and large safety factors, which, when combined, result in a sub ng/L EQS. Consequently, the use of the biota derived quality standard may be a more realistic measure of environmental risk. It may be prudent, to assess the effectiveness of controls implemented in the last few years before considering widespread end-of-pipe treatment.

Effects of iron dosing used for phosphorus removal at wastewater treatment works; impacts on forms of phosphorus discharged and secondary effects on concentrations and fate of other contaminants.

Iron dosing for phosphorus reduction during wastewater treatment is wide practised across the globe. However, the impacts of this dosing in terms of the speciation of phosphorus discharged and secondary effects on removing or introducing other trace elements from or into the effluent have not been studied. Results are presented for concentrations of a range of contaminants in over 600 wastewater treatment works, reported as mean concentration values derived from 20 effluent samples taken over a period of two years. Approximately half of the treatment works employed iron dosing to reduce concentrations of phosphorus in effluents. In addition to the expected effects on level of phosphorus discharged to surface waters, it is shown that these measures are shown to have unintended and beneficial consequences for concentrations of several other constituents of wastewater. Reductions of more than 40% in the concentrations of dissolved metals (copper, lead) benzo(a)pyrene and hexabromocyclododecane are observed. Lower but still significant decreases in concentration (>30%) are evident for dissolved cadmium, fluoranthene cypermethrin and biochemical oxygen demand. Small but less environmentally important increases are seen for iron and nickel, in the case of the latter this is presumably because nickel is a contaminant of the iron reagent used for dosing. These reductions are shown to offer significant benefits in terms of levels entering surface waters relating to the in-river environmental quality standards.

Modelling scenarios of environmental recovery after implementation of controls on emissions of persistent organic pollutants.

Comparison of monitoring data with toxicologically-derived environmental quality standards (EQSs) forms the basis of assessments of the quality status of the water environment. Having established the status quo, the logical next step is to address instances of non-compliance with EQSs by applying remedial measures, including reducing the use or at least the emission of the substances of concern or by taking steps to reduce concentrations already present using technological solutions such as enhanced wastewater treatment. The selection of suitable remedial measures must be a compromise between cost, likely effectiveness and the timescale over which improvements might be acceptable. The decision on overall environmental management has also to take into account the need for demonstrable progress; this might mean that it is preferable to address some more readily achievable goal rather than to attempt to solve a more serious, but ultimately intractable problem. This paper describes the development and application of a generic modelling tool that provides a way of assessing the potential requirements for remedial actions and their likely outcomes over a timescale of up to forty years taking account of sediment partitioning, environmental degradation and biological accumulation. The tool was validated using a detailed UK wastewater treatment works effluent discharge dataset. Examples involving several chemicals that are of current concern are provided. Some substances (e.g. tributyltin, PFOS) are identified as likely to meet EQS values in sediments or biota in a relatively short timescale; others (PAHs, DEHP) appear to represent more intractable problems.

Seasonal variation of contaminant concentrations in wastewater treatment works effluents and river waters.

Results are presented for 170 wastewater treatment works sites (20 per substance in influent, effluent and 36 per substance in river water upstream and downstream of the WwTW discharge) over a period of two years between 2015 and 2017; this comprises data for approximately 3000 samples for effluent and 6000 for river samples taken downstream of effluent discharges. Seasonal trends in contaminant concentrations for several substances are reported. Two clear patterns of seasonal variation are proposed over and above all of the variables associated with environmental data including process technology, dilution and geography. Firstly, variation of riverine concentrations caused by seasonal fluctuations in river flow (sewage flow being relatively consistent) resulting in summer maxima and winter minima. Alternatively, variation is observed that is attributable to the improved performance of wastewater treatment processes under warmer conditions. This leads to the lowest concentrations in autumn when surface water/sewage treatment temperatures tend to peak. Seasonality for trace contaminants is more difficult to characterise than that of sanitary parameters owing to the higher variability in the concentration of the substances of interest. The data also provide an insight into the amplitude of such variations. This makes it possible to assess the likely effects of seasonality and its impact on aquatic life. For example, the existence of seasonality (perhaps due only to dilution effects) might be demonstrated, but the amplitude might be too small in relation to the potential ecotoxicological effects to be of any consequence.

The association between five forms of child maltreatment and depressive and anxiety disorders: A systematic review and meta-analysis.

BACKGROUND: Child maltreatment is a global public health issue that encompasses physical abuse, sexual abuse, emotional abuse, neglect, and exposure to intimate partner violence (IPV). This systematic review and meta-analysis summarises the association between these five forms of child maltreatment and depressive and anxiety disorders. METHODS: Published cohort and case-control studies were included if they reported associations between any form of child maltreatment (and/or a combination of), and depressive and anxiety disorders. A total of 604 studies were assessed for eligibility, 106 met inclusion criteria, and 96 were included in meta-analyses. The data were pooled in random effects meta-analyses, giving odds ratios (ORs) with corresponding 95% confidence intervals (CIs) for each form of child maltreatment. RESULTS: All forms of child maltreatment were associated with depressive disorders (any child maltreatment [OR = 2.48, 2.14-2.87]; sexual abuse [OR = 2.11, 1.83-2.44]; physical abuse [OR = 1.78, 1.57-2.01]; emotional abuse [OR = 2.35, 1.74-3.18]; neglect [OR = 1.65, 1.35-2.02]; and exposure to IPV [OR = 1.68, 1.34-2.10]). Several forms of child maltreatment were significantly associated with anxiety disorders ('any child maltreatment' [OR = 1.68, 1.33-2.4]; sexual abuse [OR = 1.90, 1.6-2.25]; physical abuse [OR = 1.56, 1.39-1.76]; and neglect [OR = 1.34, 1.09-1.65]). Significant associations were also found between several forms of child maltreatment and post-traumatic stress disorder (PTSD). CONCLUSIONS: There is a robust association between five forms of child maltreatment and the development of mental disorders. The Global Burden of Disease Study (GBD) includes only sexual abuse as a risk factor for depressive and anxiety disorders. These findings support the inclusion of additional forms of child maltreatment as risk factors in GBD.

Cost minimization analysis of the treatment of distal radial fractures in the elderly.

AIMS: The aim of this study was to test the null hypothesis that there is no difference, from the payer perspective, in the cost of treatment of a distal radial fracture in an elderly patient, aged > 65 years, between open reduction and internal fixation (ORIF) and closed reduction (CR). MATERIALS AND METHODS: Data relating to the treatment of these injuries in the elderly between January 2007 and December 2015 were extracted using the Humana and Medicare Advantage Databases. The primary outcome of interest was the cost associated with treatment. Secondary analysis included the cost of common complications. Statistical analysis was performed using a non-parametric t-test and chi-squared test. RESULTS: Our search yielded 8924 patients treated with ORIF and 5629 patients treated with CR. The mean cost of an uncomplicated ORIF was more than a CR ($7749 versus $2161). The mean additional cost of a complication in the ORIF group was greater than in the CR group ($1853 versus $1362). CONCLUSION: These findings show that there are greater payer fees associated with ORIF than CR in patients aged > 65 years with a distal radial fracture. CR may be a higher-value intervention in these patients. Cite this article: Bone Joint J 2018;100-B:205-11.

Detecting environmental change: how many samples are required?

One of the most important functions of environmental monitoring is the detection of change. This can be the delineation of deteriorating circumstances or the identification of the success of remedial measures. The design of effective monitoring of change (and hence the optimisation of resources devoted to monitoring) relies on appropriate replication - knowing how many samples are required. Lack of information on the variance of the measured parameter is often a barrier to determining the optimum sampling strategy. An important new information resource on within-site variance of the concentrations of over 60 trace substances in wastewater treatment works effluents has been provided by the UK water industry research programme. This paper makes use of this resource in order to explore the potential to design monitoring programmes that will be capable of demonstrating the success of planned remedial measures that will be implemented in the coming years. Two approaches to experimental design (simple before-and-after sampling and detection of trends via correlation) are examined. It is concluded that for programmes involving numbers of samples of less than 30 the detection of a change in concentration of less than 50% might be very challenging for many of the trace substance of greatest interest. Knowledge of the difficulty of the task in hand should make it possible to design programmes that optimise the use of resources and the approaches taken, such that effects of interest are detected as soon and as economically as possible.

Lognormality of trace contaminant concentrations in sewage effluents.

It is important to understand the statistical distribution of monitoring data for them to be of value in determining the parameters of environmental models. No such distributional information has been available for many trace contaminants in sewage effluents. This paper applies the data of a major UK sewage works' effluent monitoring programme to determine the validity of the common assumption that data are lognormally distributed. Effluent quality was monitored at 162 wastewater treatment works over 1 year, generating over 3,000 results for each of over 40 substances, including metals, trace organic substances and pharmaceuticals. It is demonstrated that the lognormal assumption is clearly justified for the great majority of substances in the spatial case-for annual average effluent concentrations across different treatment works. In the site-specific, temporal case-for individual determinations of concentration at a single site over an annual period-lognormality is generally supported but not demonstrated so unequivocally for all site/substance combinations. The principal source of uncertainty was lack of sufficient numbers of observations reported to adequately low reporting limits.

An experiment in Beer-tasting.

An experiment in beer tasting among 18 first year pre-clinical students showed that only two appeared to be able to discriminate light from bitter ale correctly. As a whole the group did worse than would be expected by guessing at random on each tasting trial. Some psychological biases, one possibly as a result of the design, are indicated by the results and a possible remedy suggested. The danger of acceptance of 'views' in clinical medicine without confirmatory experimental evidence was brought out by the students own failure to confirm a hypothesis (or 'view') that they believed before hand to be beyond question.

Are extreme distal periprosthetic supracondylar fractures of the femur too distal to fix using a lateral locked plate?

It is unclear whether there is a limit to the amount of distal bone required to support fixation of supracondylar periprosthetic femoral fractures. This retrospective multicentre study evaluated lateral locked plating of periprosthetic supracondylar femoral fractures and compared the results according to extension of the fracture distal with the proximal border of the femoral prosthetic component. Between 1999 and 2008, 89 patients underwent lateral locked plating of a supracondylar periprosthetic femoral fracture, of whom 61 patients with a mean age of 72 years (42 to 96) comprising 53 women, were available after a minimum follow-up of six months or until fracture healing. Patients were grouped into those with fractures located proximally (28) and those with fractures that extended distal to the proximal border of the femoral component (33). Delayed healing and nonunion occurred respectively in five (18%) and three (11%) of more proximal fractures, and in two (6%) and five (15%) of the fractures with distal extension (p = 0.23 for delayed healing; p = 0.72 for nonunion, Fisher's exact test). Four construct failures (14%) occurred in more proximal fractures, and three (9%) in fractures with distal extension (p = 0.51). Of the two deep infections that occurred in each group, one resolved after surgical debridement and antibiotics, and one progressed to a nonunion. Extreme distal periprosthetic supracondylar fractures of the femur are not a contra-indication to lateral locked plating. These fractures can be managed with internal fixation, with predictable results, similar to those seen in more proximal fractures.

The surgical anatomy of the blood supply to the femoral head: description of the anastomosis between the medial femoral circumflex and inferior gluteal arteries at the hip.

The inferior gluteal artery is described in standard anatomy textbooks as contributing to the blood supply of the hip through an anastomosis with the medial femoral circumflex artery. The site(s) of the anastomosis has not been described previously. We undertook an injection study to define the anastomotic connections between these two arteries and to determine whether the inferior gluteal artery could supply the lateral epiphyseal arteries alone. From eight fresh-frozen cadaver pelvic specimens we were able to inject the vessels in 14 hips with latex moulding compound through either the medial femoral circumflex artery or the inferior gluteal artery. Injected vessels around the hip were then carefully exposed and documented photographically. In seven of the eight specimens a clear anastomosis was shown between the two arteries adjacent to the tendon of obturator externus. The terminal vessel arising from this anastomosis was noted to pass directly beneath the posterior capsule of the hip before ascending the superior aspect of the femoral neck and terminating in the lateral epiphyseal vessels. At no point was the terminal vessel found between the capsule and the conjoined tendon. The medial femoral circumflex artery receives a direct supply from the inferior gluteal artery immediately before passing beneath the capsule of the hip. Detailed knowledge of this anatomy may help to explain the development of avascular necrosis after hip trauma, as well as to allow additional safe surgical exposure of the femoral neck and head.

Towards the establishment of an environmental quality standard for aluminium in surface waters.

Steps taken to establish an environmental quality standard (EQS) for aluminium are described. The range of water types in England and Wales and the concentrations of low molecular weight (active) forms of aluminium have been assessed in order to evaluate the risk posed by aluminium in surface waters. Levels of low molecular weight forms of aluminium are mainly in the range 0-25 microg l(-1). Data suggest that dissolved aluminium might form the basis of a reasonably useful prediction of active aluminium leading to a simplified approach to compliance monitoring of an EQS set in terms of active aluminium.

[Femoral nail osteosynthesis. Mechanical factors influencing the femoral antetorsion]. / Mechanische Einflussfaktoren der Marknagelung auf die femorale Antetorsion. Optobiomechanische Messungen.

INTRODUCTION: Antegrade or retrograde intramedullary nailing is a common and well established procedure for the treatment of femoral shaft fractures. One drawback of this technique is the high incidence of clinically relevant malalignment. Despite intra-operative and radiological improvements this problem has not yet been solved efficiently. The aim of this study was the evaluation of the mechanical influence on the antetorsion angle of intramedullary nails during and after interlocking in femoral shaft fractures. MATERIAL AND METHODS: A mechanical instrument was developed allowing a defined torque to be administered to the distal femur fragment. As an optical measurement system for the assessment of the antetorsion angle, a navigation system was applied. Initially the influence of the interlocking mechanism of the nail on the antetorsion deviation was investigated. The distal interlocking hole was fixed free handed or by using a navigation system. The multidirectional movement of the distal femur fragment was documented. Furthermore, the influence of the rotational stability on the antetorsion angle after mechanical stress of 4 NM was investigated by measuring the remaining rotational capacity of the distal femur fragment. RESULTS: The average remaining rotational capacity of the distal femur fragment was 5.8 degrees after locking the nail by hand. The navigated locking resulted in a deviation of only 2 degrees , a significant difference compared to the free-hand procedure. The rotational stability under stress showed an average of 15.4 degrees deviation of the distal fragment. Even after complete interlocking of the intramedullary nail a 14.2 degrees rotational deviation was observed. DISCUSSION: It could be shown that mechanical stability as well as the interlocking itself of femoral nails have a relevant impact on the antetorsional angle of the femur. Potential sources of error of the femoral antetorsion angle can be caused by the interlocking process as well as by forced rotation of the femur after interlocking. Clinical studies are needed to improve our findings, while the observed effects might have an essential influence on the incidence of femoral malalignment after osteosynthesis by intramedullary nailing of the femur.

Value of 3D fluoroscopic imaging of acetabular fractures comparison to 2D fluoroscopy and CT imaging.

PURPOSE: Intraoperative two-dimensional (2D) fluoroscopy of acetabular fractures is difficult due to the complex three-dimensional (3D) anatomy. Intraoperative 3D fluoroscopy may have particular utility in the evaluation of acetabular fractures. We compared the accuracy of 3D fluoroscopic imaging in evaluating acetabular fracture displacement and implant placement with fluoroscopy and computed tomography (CT) scans. METHODS: In 24 cadaveric acetabuli, a transverse acetabular fracture was created. First a 2 mm step-off of the articular surface was created and reconstruction plates placed on the anterior and posterior columns. In 12 specimens, two screws were placed intraarticularly, protruded by 2 mm. In the remaining 12 specimens, the same constructs were used but the screws remained extraarticular. Second tests were designed to simulate an impaction injury. After hardware removal, a hollow trephine (diameter of 14.9 mm) was used to core a bone cylinder on the dome of the acetabulum, and impacted until it was recessed into the articular surface by 2 mm. Plates were placed, and screws were placed intraarticularly in 12 specimens, as in the first set of tests. All cadavers were imaged with standard 2D-, 3D fluoroscopy and CT. Three observers randomly evaluated all imaging studies for all specimens. RESULTS: For detection of intraarticular screws, both the Iso-C3D and the CT scans were significantly more sensitive (96 and 96%, respectively) and specific (96 and 100%, respectively) in detecting the intraarticular position compared to 2D fluoroscopy (75%; P < 0.05). Sensitivity of articular step-off detection was no different between the Iso-C3D (83%), CT (79%), and 2D fluoroscopy (87%). Articular impaction was correctly identified in 79% of specimens with the Iso-C 3 D technique, while the CT was accurate in 92%. 2D fluoroscopy was accurate in 62% for the impactions (P < 0.05 vs. CT). CONCLUSIONS: 3D-fluoroscopic imaging appears to be extremely accurate in evaluating acetabular fracture constructs. Its sensitivity and specificity for evaluating intraoperative hardware was greater than with 2D fluoroscopy and equivalent to CT scan. Volumetric impactions were also reliably demonstrated on both of the 3D modalities, which were both superior to 2D fluoroscopy. Overall, Iso-C3D multiplanar imaging yields information regarding implant placement and articular reduction that is more detailed and accurate than standard fluoroscopy and is comparable to CT.

[Navigation for placement of scaphoid screws : a new indication for intraoperative 3D navigation-a cadaver study]. / Die navigierte Scaphoidschraube : Eine neue Indikation zur intraoperativen 3D-Navigation - Eine Kadaverstudie.

INTRODUCTION: Up to now, the use of navigation systems for the placement of scaphoid screws has been impossible, mainly because there have been no ways of fixing the reference markers. Faulty placement rates in internal fixation of the scaphoid show there is a current need for a 3D image-based navigation system and intraoperative monitoring of how successful the procedure will be. For this reason, we have developed a new radiotransparent hand fixation device (Scaph-Splint), which allows reliable and accurate drilling of the scaphoid using 3D navigation. Tests of this device and the simultaneous precise placement of screws securing an internal fixation device are described in this paper. MATERIAL AND METHODS: Relative movements between the wrist and fixation device were measured with a 3-D ultrasound motion analyser system. Five cadaveric upper extremity specimens were then used for further navigated test applications. Each specimen was placed in the fixation device, and both the forearm and hand were secured to the two surfaces, with the wrist in approximately 80 degrees of extension. A reference marker was then securely fixed to the fixation device. A commercial navigation system and 3-D fluoroscopic imaging were used for each trial. Under navigation, the scaphoid was drilled in retrograde fashion, and a screw was placed into the drilled hole. Following screw placement, a 3D scan was performed to evaluate its position. The screw placement was analysed blindly to optimal placement and drill or screw perforation, and the image quality was rated on a visual analog scale (VAS). RESULTS: There were few artefacts, and the image quality of the 3-D scan was judged as as good (VAS 79). Deviations of >or=0.2 mm between planned trajectory and drilling tunnal were not found in any of the specimens; there were deviations of >or=1 mm in one case, and all other cases showed deviations of

Influence of lower limb rotation in navigated alignment analysis: implications for high tibial osteotomies.

Inaccurate coronal plane realignment is a common problem after high tibial osteotomy. It has been shown that lower limb rotation has an effect on the two-dimensional measurement of lower limb alignment. Although alignment errors are known to occur due to limb rotation, the magnitude of this effect is unknown. Navigation systems allow for the measurements of coronal plane alignment and dynamically rotational and sagittal plane. Our study evaluated the effect of rotational leg movements on coronal plane alignment as determined by image-free navigation. We hypothesized that a linear relationship exists between rotation and angular measurements. Eight cadavers were used, while three test conditions of the complete lower limbs were established: (1) solid knee arthrodesis, (2) provisional knee arthrodesis and (3) unconstrained knee conditions. Navigated measurements of coronal and sagittal lower limb axis were done initially without knee flexion for defined internal/external rotations of 5 degrees, 10 degrees and maximal values for all test series. Repeated test for the unconstrained knee included stepwise knee flexion of 5 degrees, 10 degrees and 20 degrees. Statistical analysis comparing the test conditions 1, 2 and 3 and comparison between flexion movements of the unconstrained knee were done. Results revealed no significant differences between the different rotations of test condition 1 (mean 0.34 degrees, SD 0.23, range, 0 degrees-0.8 degrees). Condition 2 similarly did not result in significant deviations (mean 0.51 degrees, SD 0.24, range 0.1 degrees-0.9 degrees). Measurement deviations ranging from 0.4 degrees to 4.3 degrees were found for condition 3, the unconstrained knee. However, no statistically different testings from the arthrodesed knee were found (P=0.099-0.410). Knee flexion from 5 degrees, 10 degrees or 20 degrees, showed significant deviations (P<0.05) for all rotations at all degrees of flexion. Rotation and flexion of 5 degrees led to significant alignment errors of 3.4 degrees and 2.8 degrees, respectively, for internal and external rotations. Measurement failures due to the rotational movements of 1 degree-4 degrees might add to additional sources of errors causing relevant under- or over-corrections of the mechanical leg axis. Discrepancies of the axis due to rotational movements as well as flexion of the knee joint can be avoided and corrected immediately with the help of navigation.

Vertebral height restoration in osteoporotic compression fractures: kyphoplasty balloon tamp is superior to postural correction alone.

INTRODUCTION: Kyphoplasty has been shown to restore vertebral height and sagittal alignment. Proponents of vertebroplasty have recently demonstrated that many vertebral compression fractures (VCFs) are mobile and positional correction can lead to clinically significant height restoration. The current investigation tested the hypothesis that positional maneuvers do not achieve the same degree of vertebral height correction as kyphoplasty balloon tamps for the reduction of low-energy VCFs. METHODS: Twenty-five consecutive patients with a total of 43 osteoporotic VCFs were entered into a prospective analysis. Each patient was sequentially evaluated for postural and balloon vertebral fracture reduction. Preoperative standing and lateral radiographs of the fractured vertebrae were compared with prone cross-table lateral radiographs with the patient in a hyper-extension position and on pelvic and sternal rolls. Following positional manipulation, patients underwent a unilateral balloon kyphoplasty. Postoperative standing radiographs were evaluated for the percentage of height restoration related to positioning and balloon kyphoplasty. RESULTS: In the middle portion of the vertebrae, the percentage available for restoration restored with extension positioning was 10.4% (median 11.1%) and after balloon kyphoplasty was 57.0% (median 62.2%). This difference was statistically significant (p<0.001). Thus, kyphoplasty provided an additional 46.6% of the height available for restoration from the positioning alone. With operative positioning, 51.2% of VCFs had >10% restoration of the central portion of the vertebral body, whereas 90.7% of fractures improved at least 10% following balloon kyphoplasty (p<0.002). CONCLUSION: Although this study supports the concept that many VCFs can be moved with positioning, balloon kyphoplasty enhanced the height reduction >4.5-fold over the positioning maneuver alone and accounted for over 80% of the ultimate reduction. If height restoration is the goal, kyphoplasty is clearly superior in most cases to the positioning maneuver alone.

Phase-specific gene expression underlying morphological adaptations of the dimorphic human pathogenic fungus, Coccidioides posadasii.

Coccidioides posadasii is a dimorphic fungal pathogen that grows as a filamentous saprobe in the soil and as endosporulating spherules within the host. To identify genes specific to the pathogenic phase of Co. posadasii, we carried out a large-scale study of gene expression in two isolates of the species. From the sequenced Co. posadasii genome, we chose 1,000 open reading frames to construct a 70-mer microarray. RNA was recovered from both isolates at three life-cycle phases: hyphae, presegmented spherules, and spherules releasing endospores. Comparative hybridizations were conducted in a circuit design, permitting comparison between both isolates at all three life-cycle phases, and among all life-cycle phases for each isolate. By using this approach, we identified 92 genes that were differentially expressed between pathogenic and saprobic phases in both fungal isolates, and 43 genes with consistent differential expression between the two parasitic developmental phases. Genes with elevated expression in the pathogenic phases of both isolates included a number of genes that were involved in the response to environmental stress as well as in the metabolism of lipids. The latter observation is in agreement with previous studies demonstrating that spherules contain a higher proportion of lipids than saprobic phase tissue. Intriguingly, we discovered statistically significant and divergent levels of gene expression between the two isolates profiled for 64 genes. The results suggest that incorporating more than one isolate in the experimental design offers a means of categorizing the large collection of candidate genes that transcriptional profiling typically identifies into those that are strain-specific and those that characterize the entire species.