Window into the mind: Advanced handheld spectroscopic eye-safe technology for point-of-care neurodiagnostic

Traumatic brain injury (TBI), a major cause of morbidity and mortality worldwide, is hard to diagnose at the point of care with patients often exhibiting no clinical symptoms. There is an urgent need for rapid point-of-care diagnostics to enable timely intervention. We have developed a technology for rapid acquisition of molecular fingerprints of TBI biochemistry to safely measure proxies for cerebral injury through the eye, providing a path toward noninvasive point-of-care neurodiagnostics using simultaneous Raman spectroscopy and fundus imaging of the neuroretina. Detection of endogenous neuromarkers in porcine eyes' posterior revealed enhancement of high-wave number bands, clearly distinguishing TBI and healthy cohorts, classified via artificial neural network algorithm for automated data interpretation. Clinically, translating into reduced specialist support, this markedly improves the speed of diagnosis. Designed as a hand-held cost-effective technology, it can allow clinicians to rapidly assess TBI at the point of care and identify long-term changes in brain biochemistry in acute or chronic neurodiseases.

Prevalence of intra-articular mineralization on knee computed tomography: the multicenter osteoarthritis study

OBJECTIVE

The aim of this work was to report the prevalence of computed tomography (CT)-detected intra-articular mineralization.

DESIGN

We included participants from the Multicenter Osteoarthritis (MOST) Study. At the 12th year visit of the MOST study, bilateral knee CTs were first obtained. All participants also had posteroanterior and lateral radiographs of bilateral knees and completed standard questionnaires. Knee radiographs were assessed for Kellgren & Lawrence grade (KLG) and radiographic evidence of intra-articular mineralization. CT images were scored using the Boston University Calcium Knee Score (BUCKS) for cartilage, menisci, ligaments, capsule, and vasculature. Prevalence of intra-articular mineralization was computed for the total sample, and stratified by age, sex, race, Body Mass Index (BMI), presence of frequent knee pain, and KLG. We also determined distribution of mineralization in the cartilage and meniscus, and co-localization.

RESULTS

4140 bilateral knees from 2070 participants were included (56.7% female, mean age 61.1 years, mean BMI: 28.8 kg/m2). On radiographs 240 knees (5.8%) had intraarticular mineralization, while CT-detected mineralization was present in 9.8% of knees. Prevalence of hyaline articular and meniscus mineralization increased with age and KL grade, and was similar by sex, BMI categories, and comparable in subjects with and without frequent knee pain. Mineralization tended to be ubiquitous in the joint, most commonly involving all three (medial/lateral tibiofemoral and patellofemoral) compartments (3.1%), while the patellofemoral compartment was the most involved compartment in isolation (1.4%).

CONCLUSIONS

CT of the knee provides greater visualization of intra-articular mineralization than radiographs and allows better localization of the crystal deposition within the joint. Further studies should focus on the co-localization of intra-articular crystal deposition and corresponding magnetic resonance imaging (MRI)-features of knee osteoarthritis (OA).

Comparison of Screw Quantity and Placement of Metacarpal Fracture Fixation: A Biomechanical Study

BACKGROUND

It is recommended to have 6 bicortical screws for plate fixation of long bone fractures; however, many metacarpal fractures do not allow 6 screws due to size limitations and proximity of crucial anatomical structures. The purpose of this biomechanical study was to determine whether the mechanical properties of a 4-screw nonlocking construct are noninferior to those of a 6-screw nonlocking construct.

METHODS

Metacarpal sawbones were used to simulate a midshaft, transverse fracture. Nonlocking bicortical screws were placed in the 6-hole plate, and the metacarpals were randomly assigned to 2 equal study groups: (1) 4 screws, 2 on either side of the fracture (4S); and (2) 6 screws, 3 on either side of the fracture (6S). The metacarpals were tested in a cyclic loading mode and load to failure in a cantilever bending mode.

RESULTS

Maximum deflection was significantly higher for 4S compared with 6S. Cyclic root mean square (RMS) was also significantly greater for 4S at 70 and 100 N. There were no statistically significant differences observed between the 2 constructs for maximum bending load, bending stiffness, and cyclic RMS at 40 N. The maximum bending load in 4S and 6S was 245.6 ± 37.9 N and 230.8 ± 41.9 N, respectively; 4S was noninferior and not superior to 6S. Noninferiority testing was inconclusive for bending stiffness.

CONCLUSIONS

A 4-screw bicortical nonlocking construct is noninferior to a 6-screw bicortical nonlocking construct for fixation of metacarpal fractures, which may be advantageous to minimize disruption of soft tissues while maintaining sufficient construct stability.

Spectroscopic molecular-fingerprint profiling of saliva

Saliva analysis has been gaining interest as a potential non-invasive source of disease indicative biomarkers due to being a complex biofluid correlating with blood-based constituents on a molecular level. For saliva to cement its usage for analytical applications, it is paramount to gain underpinning molecular knowledge and establish a 'baseline' of the salivary composition in healthy individuals as well as characterize how these factors are impacting its performance as potential analytical biofluid. Here, we have systematically studied the molecular spectral fingerprint of saliva, including the changes associated with gender, age, and time. Via hybrid artificial neural network algorithms and Raman spectroscopy, we have developed a non-destructive molecular profiling approach enabling the assessment of salivary spectral changes yielding the determination of gender and age of the biofluid source. Our classification algorithm successfully identified the gender and age from saliva with high classification accuracy. Discernible spectral molecular 'barcodes' were subsequently constructed for each class and found to primarily stem from amino acid, protein, and lipid changes in saliva. This unique combination of Raman spectroscopy and advanced machine learning techniques lays the platform for a variety of applications in forensics and biosensing.

Increasing specialist intensity at weekends to improve outcomes for patients undergoing emergency hospital admission: the HiSLAC two-phase mixed-methods study

Background

NHS England’s 7-day services policy comprised 10 standards to improve access to quality health care across all days of the week. Six standards targeted hospital specialists on the assumption that their absence caused the higher mortality associated with weekend hospital admission: the ‘weekend effect’. The High-intensity Specialist-Led Acute Care (HiSLAC) collaboration investigated this using the implementation of 7-day services as a ‘natural experiment’.

Objectives

The objectives were to determine whether or not increasing specialist intensity at weekends improves outcomes for patients undergoing emergency hospital admission, and to explore mechanisms and cost-effectiveness.

Design

This was a two-phase mixed-methods observational study. Year 1 focused on developing the methodology. Years 2–5 included longitudinal research using quantitative and qualitative methods, and health economics.

Methods

A Bayesian systematic literature review from 2000 to 2017 quantified the weekend effect. Specialist intensity measured over 5 years used self-reported annual point prevalence surveys of all specialists in English acute hospital trusts, expressed as the weekend-to-weekday ratio of specialist hours per 10 emergency admissions. Hospital Episode Statistics from 2007 to 2018 provided trends in weekend-to-weekday mortality ratios. Mechanisms for the weekend effect were explored qualitatively through focus groups and on-site observations by qualitative researchers, and a two-epoch case record review across 20 trusts. Case-mix differences were examined in a single trust. Health economics modelling estimated costs and outcomes associated with increased specialist provision.

Results

Of 141 acute trusts, 115 submitted data to the survey, and 20 contributed 4000 case records for review and participated in qualitative research (involving interviews, and observations using elements of an ethnographic approach). Emergency department attendances and admissions have increased every year, outstripping the increase in specialist numbers; numbers of beds and lengths of stay have decreased. The reduction in mortality has plateaued; the proportion of patients dying after discharge from hospital has increased. Specialist hours increased between 2012/13 and 2017/18. Weekend specialist intensity is half that of weekdays, but there is no relationship with admission mortality. Patients admitted on weekends are sicker (they have more comorbid disease and more of them require palliative care); adjustment for severity of acute illness annuls the weekend effect. In-hospital care processes are slightly more efficient at weekends; care quality (errors, adverse events, global quality) is as good at weekends as on weekdays and has improved with time. Qualitative researcher assessments of hospital weekend quality concurred with case record reviewers at trust level. General practitioner referrals at weekends are one-third of those during weekdays and have declined further with time.

Limitations

Observational research, variable survey response rates and subjective assessments of care quality were compensated for by using a difference-in-difference analysis over time.

Conclusions

Hospital care is improving. The weekend effect is associated with factors in the community that precede hospital admission. Post-discharge mortality is increasing. Policy-makers should focus their efforts on improving acute and emergency care on a ‘whole-system’ 7-day approach that integrates social, community and secondary health care.

Future work

Future work should evaluate the role of doctors in hospital and community emergency care and investigate pathways to emergency admission and quality of care following hospital discharge.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 9, No. 13. See the NIHR Journals Library website for further project information.

Spectroscopic profiling variations in extracellular vesicle biochemistry in a model of myogenesis

Extracellular vesicles (EVs) hold value as accessible biomarkers for understanding cellular differentiation and related pathologies. Herein, EV biomarkers in models of skeletal muscle dormancy and differentiation have been comparatively profiled using Raman spectroscopy (RS). Significant variations in the biochemical fingerprint of EVs were detected, with an elevation in peaks associated with lipid and protein signatures during early myogenic differentiation (day 2). Principal component analysis revealed a clear separation between the spectra of EVs derived from myogenic and senescent cell types, with non-overlapping interquartile ranges and population median. Observations aligned with nanoparticle tracking data, highlighting a significant early reduction in EV concentration in senescent myoblast cultures as well as notable variations in EV morphology and diameter. As differentiation progressed physical and biochemical differences in the properties of EVs became less pronounced. This study demonstrates the applicability of RS as a high-resolution analytical method for profiling biochemical changes in EVs during early myogenesis.

The Valsalva maneuver: an indispensable physiological tool to differentiate intra versus extracranial near-infrared signal

Developing near-infrared spectroscopy (NIRS) parameter recovery techniques to more specifically resolve brain physiology from that of the overlying tissue is an important part of improving the clinical utility of the technology. The Valsalva maneuver (VM) involves forced expiration against a closed glottis causing widespread venous congestion within the context of a fall in cardiac output. Due to the specific anatomical confines and metabolic demands of the brain we believe a properly executed VM has the ability to separate haemodynamic activity of brain tissue from that of the overlying scalp as observed by NIRS, and confirmed by functional magnetic resonance imaging (fMRI). Healthy individuals performed a series of standing maximum effort VMs under separate observation by frequency domain near-infrared spectroscopy (FD-NIRS) and fMRI. Nine individuals completed the clinical protocol (6 males, age 21-40). During the VMs, brain and extracranial tissue targeted signal were significantly different (opposite direction of change) in both fMRI and NIRS (p=0.00025 and 0.00115 respectively), with robust cross correlation of parameters between modalities. Four of these individuals performed further VMs after infiltrating 2% xylocaine/1:100,000 epinephrine (vasoconstrictor) into scalp tissue beneath the probes. No significant difference in the cerebrally derived parameters was observed. The maximum effort VM has the ability to separate NIRS observable physiology of the brain from the overlying extracranial tissue. Observations made by this FD cerebral NIRS device are comparable with fMRI in this context.

Simultaneous Detection of Seven Drugs of Abuse by the TriageTM Panel for Drugs of Abuse

This novel, competitive immunoassay simultaneously detects seven drugs of abuse in urine. A urine sample is placed in contact with lyophilized reagents, the reaction mixture is allowed to come to equilibrium (10 min), and then the whole mixture is applied to a solid phase that contains various immobilized antibodies in discrete drug-class-specific zones. After a washing step, the operator visually examines each zone for the presence of a red bar. The method incorporates present threshold concentrations that are independent for each drug. In the absence of drug or in the presence of drug in quantities less than the threshold concentration, no colored bar is visible. Samples containing drug(s) at or above the threshold concentration cause a red bar to appear for the appropriate drug(s). Positive and negative procedural control zones are incorporated into each determination. The performance of the assay methodology matches that of instrumented immunoassay systems.

Cerebral Oxygenation in Traumatic Brain Injury: Can a Non-Invasive Frequency Domain Near-Infrared Spectroscopy Device Detect Changes in Brain Tissue Oxygen Tension as Well as the Established Invasive Monitor?

The cost and highly invasive nature of brain monitoring modality in traumatic brain injury patients currently restrict its utility to specialist neurological intensive care settings. We aim to test the abilities of a frequency domain near-infrared spectroscopy (FD-NIRS) device in predicting changes in invasively measured brain tissue oxygen tension. Individuals admitted to a United Kingdom specialist major trauma center were contemporaneously monitored with an FD-NIRS device and invasively measured brain tissue oxygen tension probe. Area under the curve receiver operating characteristic (AUROC) statistical analysis was utilized to assess the predictive power of FD-NIRS in detecting both moderate and severe hypoxia (20 and 10 mm Hg, respectively) as measured invasively. Sixteen individuals were prospectively recruited to the investigation. Severe hypoxic episodes were detected in nine of these individuals, with the NIRS demonstrating a broad range of predictive abilities (AUROC 0.68-0.88) from relatively poor to good. Moderate hypoxic episodes were detected in seven individuals with similar predictive performance (AUROC 0.576-0.905). A variable performance in the predictive powers of this FD-NIRS device to detect changes in brain tissue oxygen was demonstrated. Consequently, this enhanced NIRS technology has not demonstrated sufficient ability to replace the established invasive measurement.

Frequency-domain vs continuous-wave near-infrared spectroscopy devices: a comparison of clinically viable monitors in controlled hypoxia

The Near-infrared spectroscopy (NIRS) has not been adopted as a mainstream monitoring modality in acute neurosurgical care due to concerns about its reliability and consistency. However, improvements in NIRS parameter recovery techniques are now available that may improve the quantitative accuracy of NIRS for this clinical context. Therefore, the aim of this study was to compare the abilities of a continuous-wave (CW) NIRS device with a similarly clinically viable NIRS device utilising a frequency-domain (FD) parameter recovery technique in detecting changes in cerebral tissue saturation during stepwise increases of experimentally induced hypoxia. Nine healthy individuals (6M/3F) underwent a dynamic end-tidal forced manipulation of their expiratory gases to induce a stepwise induced hypoxia. The minimum end-tidal oxygen partial pressure (EtO₂) achieved was 40 mm Hg. Simultaneous neurological and extra-cranial tissue NIRS reading were obtained during this protocol by both tested devices. Both devices detected significant changes in cerebral tissue saturation during the induction of hypoxia (CW 9.8 ± 2.3 %; FD 7.0 ± 3.4 %; Wilcoxon signed rank test P < 0.01 for both devices). No significant difference was observed between the saturation changes observed by either device (P = 0.625). An observably greater degree of noise was noticed in parameters recovered by the FD device, and both demonstrated equally variable baseline readings (Coefficient of variance 8.4 and 9.7 % for the CW and FD devices, respectively) between individuals tested. No advantageous difference was observed in parameters recovered from the FD device compared with those detected by CW.

Improving the quantitative accuracy of cerebral oxygen saturation in monitoring the injured brain using atlas based Near Infrared Spectroscopy models

The application of Near Infrared Spectroscopy (NIRS) for the monitoring of the cerebral oxygen saturation within the brain is well established, albeit using temporal data that can only measure relative changes of oxygenation state of the brain from a baseline. The focus of this investigation is to demonstrate that hybridisation of existing near infrared probe designs and reconstruction techniques can pave the way to produce a system and methods that can be used to monitor the absolute oxygen saturation in the injured brain. Using registered Atlas models in simulation, a novel method is outlined by which the quantitative accuracy and practicality of NIRS for specific use in monitoring the injured brain, can be improved, with cerebral saturation being recovered to within 10.1 ± 1.8% of the expected values.

The interference effect of concurrent working memory task on visual inhibitory control

We examined the interference between inhibitory control of a saccadic eye movement and a working memory task. This study was motivated by the observation that people are suscep-tible to cognitive errors when they are preoccupied. Subjects were instructed to make an anti-saccade, or to look in the opposite direction of a visual stimulus, thereby exercising inhibito-ry control over the reflexive eye movement towards a salient object. At the same time, the subjects were instructed to memorize a random sequence of digits that were read out to them, thereby engaging their working memory. We measured the success of an eye movement by rapidly switching between images and asking the subjects what they saw. We found that these concurrent cognitive tasks significantly degraded anti-saccade performance.We examined the interference between inhibitory control of a saccadic eye movement and a working memory task. This study was motivated by the observation that people are susceptible to cognitive errors when they are preoccupied. Subjects were instructed to make an anti-saccade, or to look in the opposite direction of a visual stimulus, thereby exercising inhibitory control over the reflexive eye movement towards a salient object. At the same time, the subjects were instructed to memorize a random sequence of digits that were read out to them, thereby engaging their working memory. We measured the success of an eye movement by rapidly switching between images and asking the subjects what they saw. We found that these concurrent cognitive tasks significantly degraded anti-saccade performance.

A noninvasive method for in situ determination of mating success in female American lobsters (Homarus americanus)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female's seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George's Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations.

Future challenges in renal transplantation

There is a worldwide increase in the incidence of end-stage renal disease. Renal transplantation has been shown to be cost effective, prolong survival and provide a better quality of life in comparison to dialysis. Consequently, there has been a steady increase in demand for organs leading to a shortage of available kidneys, and an increase in transplant waiting lists. Renal transplantation is therefore an expanding field with a number of unique future challenges to address. This article outlines strategies that may be employed to expand organ supply in order to meet increased demand. The ethical issues surrounding this are also summarized. Furthermore, we highlight techniques with the potential to minimize peri-transplant injury to the kidney on its journey from donor to recipient. Current and potential future management strategies to optimize graft and patient survival are also discussed.

Association between patella alta and the prevalence and worsening of structural features of patellofemoral joint osteoarthritis: the multicenter osteoarthritis study

OBJECTIVE

To examine the relationship between patella alta and the prevalence and worsening at followup of structural features of patellofemoral joint (PFJ) osteoarthritis (OA) on magnetic resonance imaging (MRI).

METHODS

The Multicenter Osteoarthritis Study is a cohort study of persons ages 50-79 years with or at risk for knee OA. Patella alta was measured using the Insall-Salvati ratio (ISR) on the baseline lateral radiograph, and cartilage damage, bone marrow lesions (BMLs), and subchondral bone attrition (SBA) were graded on MRI at baseline and at 30 months of followup in the PFJ. We examined the association of the ISR with the prevalence and worsening of cartilage damage, BMLs, and SBA in the PFJ using logistic regression.

RESULTS

A total of 907 knees were studied (mean age 62 years, body mass index 30 kg/m(2), ISR 1.10), 63% from female subjects. Compared with knees in the lowest ISR quartile at baseline, those in the highest quartile had 2.4 (95% confidence interval [95% CI] 1.7-3.3), 2.9 (95% CI 2.0-4.3), and 3.5 (95% CI 2.3-5.5) times the odds of having lateral PFJ cartilage damage, BMLs, and SBA, respectively, and 1.5 (95% CI 1.1-2.0), 1.3 (95% CI 0.9-1.8), and 2.2 (95% CI 1.4-3.4) times the odds of having medial PFJ cartilage damage, BMLs, and SBA, respectively. Similarly, those with high ISRs were also at risk for worsening of cartilage damage and BMLs over time than those with low ISRs.

CONCLUSION

A high ISR, indicative of patella alta, is associated with structural features of OA in the PFJ. Additionally, the same knees have an increased risk of worsening of these same features over time.

Relation of synovitis to knee pain using contrast-enhanced MRIs

BACKGROUND

It has been suggested that synovitis causes joint pain. On non-contrast-enhanced MRIs synovial thickening cannot be assessed and on these images synovitis has been inconsistently associated with pain.

OBJECTIVE

To assess synovial thickening in relation to knee pain severity among subjects in the Multicenter Osteoarthritis Study (MOST) using contrast-enhanced (CE) MRI.

METHODS

MOST is a cohort study of people who have, or are at high risk of, knee osteoarthritis (OA). An unselected subset of 535 participants who volunteered underwent CE 1.5 T MRI of one knee. Synovitis was scored in six compartments and a summary score was created. Knee pain severity was assessed using the maximum item score on the Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain scale. The association between synovitis and pain severity was examined using a logistic regression model adjusting for age, sex, body mass index (BMI), MRI bone marrow lesions and effusions in the whole sample and in a subgroup without radiographic OA.

RESULTS

454 of the 535 subjects undergoing CE MRI had complete data on synovitis and WOMAC pain. Mean age was 59 years, mean BMI 30 and 48% were women. In knees with moderate pain, 80% had synovitis. For knee pain, synovitis conferred a 9.2-fold increased odds compared with those without synovitis. In knees without radiographic OA (n=329), there was also an association of synovitis with an increased prevalence of pain.

CONCLUSION

Synovitis has a strong relation with knee pain severity, an association detected more clearly with CE MRI than suggested by previous studies using non-CE MRI measures of synovitis.

BK viremia surveillance after kidney transplant: single-center experience during a change from cyclosporine-to lower-dose tacrolimus-based primary immunosuppression regimen

BACKGROUND

The aim was to report our experience of BK viremia surveillance after kidney transplant during a period of change from cyclosporine (CyA)-to lower-dose tacrolimus (Tac)-based primary immunosuppression regimens.

METHODS

In a prospective single-center observational cohort study, 68 consecutive patients received renal transplant during the period when we used a CyA-based primary immunosuppression regimen and 66 after we changed to a lower-dose Tac-based regimen. Testing for BK viremia by quantitative polymerase chain reaction assay was performed at least monthly for a minimum of 1 year.

RESULTS

Thirty-nine (29.1%) patients developed BK viremia and 2 (1.5%) developed BK nephropathy. The actuarial time to BK viremia was shorter in patients receiving CyA/mycophenolate mofetil (MMF)/prednisolone (Pred) compared with Tac/MMF/Pred (P=0.04) and primary immunosuppression with CyA/MMF/Pred was the only independent predictor of BK viremia (hazard ratio 1.95; P=0.047). Comparing patients who experienced BK viremia and those who did not, there was no difference in incidence of acute rejection (20.5% vs. 25.3%; P=0.56) or estimated glomerular filtration rate at 12 months (48.8 vs. 49.9 mL/min/1.73 m(2)), but the incidence of ureteric stenosis was higher (10.3% vs. 1.1%; P=0.01).

CONCLUSIONS

Our data demonstrate a lower incidence of BK viremia in patients on lower-dose Tac compared with CyA-based primary immunosuppression in contrast to previous studies, and provide further support for the association between BK virus and ureteric complications.

Concurrent cocaine and alcohol use in individuals presenting to an addiction treatment program

BACKGROUND

National population surveys and information from the National Drug Treatment Reporting System indicate cocaine use is increasing. There is a paucity of studies focusing on comorbid cocaine and alcohol use in Ireland.

AIMS

The aims of the study are to examine comorbid cocaine and alcohol use patterns in those under 45 years, presenting to a national addiction treatment unit for alcohol and drug dependence.

METHODS

A retrospective review of the substance misuse behavior of 465 individuals participating in an addiction rehabilitation programme for alcohol dependence.

RESULTS

Cocaine use among this population rose significantly between 1995 (8%) and 2006 (37.9%). There was a significant association between lifetime reported cocaine use and both psychotic disorders and deliberate self harm. Overall, the use was highest among younger age group and this declined steadily with age.

CONCLUSIONS

Cocaine use among the alcohol-dependent population is an increasing problem in the Republic of Ireland, and poses a problem of higher toxicity associated with concurrent cocaine and alcohol use.

Is obesity a risk factor for progressive radiographic knee osteoarthritis?

OBJECTIVE

To examine whether obesity increases the risk of progression of knee osteoarthritis (OA).

METHODS

We used data from the Multicenter Osteoarthritis Study, a longitudinal study of persons with or at high risk of knee OA. OA was characterized at baseline and 30 months using posteroanterior fixed-flexion radiographs and Kellgren/Lawrence (K/L) grading, with alignment assessed on full-extremity films. In knees with OA at baseline (K/L grade 2 or 3), progression was defined as tibiofemoral joint space narrowing on the 30-month radiograph. In knees without OA at baseline (K/L grade 0 or 1), incident OA was defined as the development of radiographic OA at 30 months. Body mass index (BMI) at baseline was classified as normal (<25 kg/m(2)), overweight (25-<30 kg/m(2)), obese (30-<35 kg/m(2)), and very obese (>or=35 kg/m(2)). The risk of progression was tested in all knees and in subgroups categorized according to alignment. Analyses were adjusted for age, sex, knee injury, and bone density.

RESULTS

Among the 2,623 subjects (5,159 knees), 60% were women, and the mean +/- SD age was 62.4 +/- 8.0 years. More than 80% of subjects were overweight or obese. At baseline, 36.4% of knees had tibiofemoral OA, and of those, only one-third were neutrally aligned. Compared with subjects with a normal BMI, those who were obese or very obese were at an increased risk of incident OA (relative risk 2.4 and 3.2, respectively [P for trend < 0.001]); this risk extended to knees from all alignment groups. Among knees with OA at baseline, there was no overall association between a high BMI and the risk of OA progression; however, an increased risk of progression was observed among knees with neutral but not varus alignment. The effect of obesity was intermediate in those with valgus alignment.

CONCLUSION

Although obesity was a risk factor for incident knee OA, we observed no overall relationship between obesity and the progression of knee OA. Obesity was not associated with OA progression in knees with varus alignment; however, it did increase the risk of progression in knees with neutral or valgus alignment. Therefore, weight loss may not be effective in preventing progression of structural damage in OA knees with varus alignment.

Recording of vital signs in a district general hospital emergency department

AIM

To examine and explore factors that may influence the recording of vital signs in adult patients within the initial 15 min and again within 60 min of arrival in the "resuscitation" and "major" areas of the emergency department (ED).

METHODS

A retrospective analysis of recording of vital signs was performed on 400 consecutive sets of notes from adult patients presenting to the "major" or "resuscitation" areas of a district general hospital ED. The effect of staffing levels, triage category and attendances on the recording of vital signs was examined using logistic regression. The main outcome measures were the proportion of patients with all vital signs recorded within 15 min of arrival, the proportion of patients with all vital signs repeated within 60 min of arrival and the outcomes of logistic regression analysis.

RESULTS

Only 223/387 patients (58%) had all vital signs recorded within 15 min of arrival and only 29/387 (7%) had all vital signs repeated at 60 min. There was a significant relationship between the failure to record vital signs and lower triage categories. There was no evidence that staffing levels or number of attendances predicted the recording of vital signs within 15 min of arrival.

CONCLUSION

Recording of vital signs was poor and unrelated to staffing levels or numbers of patients attending the ED. Failure to record patients' vital signs undermines strategies to detect and manage ill patients.

Enhancing learning management systems to better support computer science education

Many individual instructors -- and, in some cases, entire universities -- are gravitating towards the use of comprehensive learning management systems (LMSs), such as Blackboard and Moodle, for managing courses and enhancing student learning. As useful as LMSs are, they are short on features that meet certain needs specific to computer science education. On the other hand, computer science educators have developed--and continue to develop-computer-based software tools that aid in management, teaching, and/or learning in computer science courses. In this report we provide an overview of current CS specific on-line learning resources and guidance on how one might best go about extending an LMS to include such tools and resources. We refer to an LMS that is extended specifically for computer science education as a Computing Augmented Learning Management System, or CALMS. We also discuss sound pedagogical practices and some practical and technical principles for building a CALMS. However, we do not go into details of creating a plug-in for some specific LMS. Further, the report does not favor one LMS over another as the foundation for a CALMS.

Determination of the size of the different sepsis categories presenting to a UK teaching hospital emergency department

AIM

To establish the size of the population of patients presenting to a UK emergency department (ED) with systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis and septic shock and to determine their mortality and length of stay.

SETTING

Southampton General Hospital Emergency Department, a teaching hospital treating 90,000 patients per annum.

METHOD

A retrospective audit of all patients attending the ED for a 1-month period was undertaken in order to classify them into the different sepsis groups. Length of stay and mortality data were abstracted from the Patient Administration System, a computerised database.

RESULTS

137 (SIRS), 123 (sepsis) and 50 (severe sepsis or septic shock) patients were classified from 5832 new patients attending. The median length of stay was 5, 3 and 7.5 days, respectively, and the mortality was 6.6%, 4.1% and 26%, respectively. The incidence of severe sepsis or septic shock was 30 per 1000 patients admitted.

CONCLUSION

The high incidence of severe sepsis and septic shock with its attendant high mortality and length of stay is highlighted. If the figures are annualized, this would equate to 650 cases of severe sepsis or septic shock, of which 169 would die. The ED is well placed to improve this outcome by earlier detection and the use of goal directed therapy.

Can mortality rates for patients who die within the emergency department, within 30 days of discharge from the emergency department, or within 30 days of admission from the emergency department be easily measured?

OBJECTIVES

Death rates are an outcome that can be used to describe a service. We measured three death rates that can be used to describe an emergency department (ED): death rates for those seen in the ED and discharged, those that die within the ED, and those that die after admission. We also wanted to establish how easy it was to obtain these rates and how frequently autopsy was performed.

SETTING

ED within a large teaching hospital.

RESULTS

Between 1 December 2003 and 1 December 2004, 76,060 patients attended the ED of which 205 died within the department. A total of 16,489 were admitted of which 876 died within 30 days. A total of 59,366 were discharged home of which 111 subsequently died over the next 30 days. The rates were 0.19% (111/59,366) for those discharged, 4.6% (766/16,489) for those admitted, and 0.27% (205/76,060) for those patients attending the ED who died within it. The autopsy rate was low (20%) and was more likely if the patient died in the department, died within the first few days of admission, or was young. The data were easy to collect.

CONCLUSIONS

These three death rates were easy to calculate and could be used to describe the outcome of an ED service. Further research to establish the range of rates for different departments is now required to determine their potential use.

Cigarette smoking and the risk for cartilage loss and knee pain in men with knee osteoarthritis

OBJECTIVE

To examine the effects of smoking on cartilage loss and pain at the knee in individuals with knee osteoarthritis.

METHODS

159 men with symptomatic knee osteoarthritis who participated in a 30-month, prospective, natural history study of knee osteoarthritis were examined. The more symptomatic knee was imaged using magnetic resonance imaging (MRI) at baseline, and again at 15 and 30 months of follow-up. Cartilage was scored using the Whole-Organ MRI Score semiquantitative method at the medial and lateral tibiofemoral joints and at the patellofemoral joint. At baseline and follow-up visits, the severity of knee pain was assessed using a Visual Analogue Scale pain score (0-100 mm).

RESULTS

Among the 159 men, 19 (12%) were current smokers at baseline. Current smokers were younger (mean (standard deviation (SD)) age 62 (9) v 69 (9) years) and leaner (mean (SD) body mass index (BMI): 28.9 (3.2) v 31.3 (4.8) kg/m(2)) than men who were not current smokers. When adjusted for age, BMI and baseline cartilage scores, men who were current smokers were found to have an increased risk for cartilage loss at the medial tibiofemoral joint (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.0 to 5.4) and the patellofemoral joint (OR 2.5, 95% CI 1.1 to 5.7). Current smokers also had higher adjusted pain scores at baseline (60.5 v 45.0, p<0.05) and at follow-up (59.4 v 44.3, p<0.05) than men who were not current smokers.

CONCLUSIONS

Men with knee osteoarthritis who smoke sustain greater cartilage loss and have more severe knee pain than men who do not smoke.

The association of meniscal pathologic changes with cartilage loss in symptomatic knee osteoarthritis

OBJECTIVE

To explore the role of meniscal tears and meniscal malposition as risk factors for subsequent cartilage loss in subjects with symptomatic osteoarthritis (OA).

METHODS

Study subjects were patients with symptomatic knee OA from the Boston Osteoarthritis of the Knee Study. Baseline assessments included knee magnetic resonance imaging (MRI) with followup MRI at 15 and 30 months. Cartilage and meniscal damage were scored on MRI in the medial and lateral tibiofemoral joints using the semiquantitative whole-organ magnetic resonance imaging score. Tibiofemoral cartilage was scored on MR images of all 5 plates of each tibiofemoral joint, and the meniscal position was measured using eFilm Workstation software. A proportional odds logistic regression model with generalized estimating equations was used to assess the effect of each predictor (meniscal position factor and meniscal damage as dichotomous predictors in each model) on cartilage loss in each of the 5 plates within a compartment. Models were adjusted for age, body mass index (BMI), tibial width, and sex.

RESULTS

We assessed 257 subjects whose mean +/- SD age was 66.6 +/- 9.2 years and BMI was 31.5 +/- 5.7 kg/m2; 42% of subjects were female, and 77% of knees had a Kellgren/Lawrence radiographic severity grade > or = 2. In the medial tibiofemoral joint, each measure of meniscal malposition was associated with an increased risk of cartilage loss. There was also a strong association between meniscal damage and cartilage loss. Since meniscal coverage and meniscal height diminished with subluxation, less coverage and reduced height also increased the risk of cartilage loss.

CONCLUSION

This study highlights the importance of an intact and functioning meniscus in patients with symptomatic knee OA, since the findings demonstrate that loss of this function has important consequences for cartilage loss.

Whiplash associated disorder: incidence and natural history over the first month for patients presenting to a UK emergency department

OBJECTIVES

To describe the epidemiology, process of care, and outcomes at 4-6 weeks after injury among patients with whiplash associated disorder attending a UK emergency department.

METHODS

All patients presenting during the study period with neck pain following a road traffic accident who met the inclusion criteria were assessed. Patients were followed up with a telephone interview at 4-6 weeks after attendance using the Neck Disability Index (NDI). The patient's general practitioner (GP) was contacted post attendance to ascertain subsequent healthcare use.

RESULTS

A total of 200 patients were recruited to the study, of which 30 were lost to follow up. Four variables, midline tenderness (p = 0.008; 95% CI 0.9 to 6.1), x ray request (p = 0.004; 0.9 to 6.1), wearing a seat belt (p = 0.038; 0.2 to 6.2), and having seen their GP post injury (p = 0.001; CI -10.5 to 6.6), were found to be associated with a higher NDI score at follow up. Significant correlation was identified with a high pain score and an increasing age of patient and high NDI scores. No correlation was found between the impact speed, speed of vehicle struck, or time since incident with the NDI. Two thirds of patients had some disability at 4-6 weeks after injury; 91 patients (54.5%) saw their GP in the intervening period between attending the department and telephone follow up, and 87/170 patients had no idea about their prognosis.

CONCLUSIONS

This study identifies that there is significant disability associated with whiplash associated disorder. Clear prognostic information would be a useful development.

Preservation of embryonic kidneys for transplantation

BACKGROUND

Long-term storage of embryonic kidneys is crucial for the organization of transplantation and organ banking. In this study, we investigated the effects of controlled-rate freezing and ice-free vitrification on metanephroi (MN) viability.

METHODS

Metanephroi isolated from 15-day (E15) timed pregnant Lewis rats were either: (i) frozen, using a DMSO/FCS/RPMI solution and a controlled freezing rate of -0.3 degrees C/min, from -10 degrees to -40 degrees C; or (ii) cryopreserved in an ice-free state by rapid cooling to -100 degrees C in cryoprotectant (VS55), followed by vitrification to -120 degrees C. After cryopreservation, the metanephroi were stored at -135 degrees C for 48 hours. After storage the MN were rewarmed, resuspended in culture media, and their viability was assessed using the AlamarBlue assay and histology (light microscopy, TEM, and cryosubstitution).

RESULTS

There was statistically no difference in embryonic kidney metabolic activity of either of the cryopreserved MN groups relative to the control untreated group. However, cryosubstitution demonstrated the presence of significant ice formation during controlled-rate freezing, yet in contrast the amount of ice was significantly reduced by vitrification. This was confirmed by TEM, where vacuolation of the cytoplasm of controlled-rate frozen metanephroi was observed, whereas vitrified metanephroi had little cytoplasmic disruption. However, vitrified metanephroi showed mitochondrial and nuclear injury at the cellular level.

CONCLUSIONS

There is a need for long-term storage of organs to make MN transplantation a reality. This study demonstrates that standard freezing methods are unsuitable for this purpose. Vitrification yielded more promising results, but further development is required.

Admissions to intensive care units from emergency departments: a descriptive study

OBJECTIVES

To describe the case mix, activity, and outcome for admissions to intensive care units (ICUs) from emergency departments (EDs).

DESIGN

An observational study using data from a high quality clinical database, the Case Mix Programme Database, of intensive care admissions, coordinated at the Intensive Care National Audit & Research Centre (ICNARC).

SETTING

91 adult ICUs in England, Wales, and Northern Ireland, 1996-99.

SUBJECTS

46,587 intensive care admissions.

MAIN OUTCOME MEASURES

Ultimate hospital mortality.

RESULTS

Admissions from EDs constituted 26% of total admissions to ICU, 77% of which were direct admissions to ICU from EDs. Direct admissions from EDs, indirect admissions from EDs, and non-ED admissions presented to ICU with different conditions and severity of illness. Indirect admissions from EDs presented in the ICU with the more severe case mix (older age, more acute severity of illness, more likely to have a chronic illness) compared with direct admissions to ICU from EDs. Compared with ICU admissions not originating in EDs, unit and hospital mortality were higher for admissions from EDs, with indirect admissions experiencing the highest hospital (46.4%) mortality. For ICU survivors, indirect admissions stayed longest in the ICU.

CONCLUSIONS

A large proportion of admissions to ICU (26%) originate in EDs, and differ from those not originating in EDs in terms of both case mix and outcome. Additionally, those admitted directly to ICU from EDs differ from those admitted indirectly via a ward. The observed differences in outcome between different admission routes require further investigation and explanation.

Randomised controlled trial of patient controlled analgesia compared with nurse delivered analgesia in an emergency department

OBJECTIVE

To compare effectiveness, safety, and patient satisfaction of patient controlled analgesia (PCA) with titrated, intravenous opioid injections for the management of acute traumatic pain in the emergency department (ED).

METHODS

The study took place in the ED of a teaching hospital. Patients suffering traumatic injury requiring opioid analgesia, and meeting other inclusion criteria, were consented and randomised to either the study group or control group. The study group were given morphine through the PCA system, whereas the control group were given morphine via the conventional route of nurse titration. Pain levels were measured using a visual analogue scale. Both groups had their vital signs (blood pressure, pulse, oxygen saturations, Glasgow coma score, respiratory rate) and pain scores monitored at 0, 15, 30, 45, 60, 90, and 120 minutes, and any adverse events were noted. Patients were followed up with a questionnaire asking about their experience of pain relief in the department.

RESULTS

86 patients were recruited to the study, 43 in each group. There was no significant difference between the groups in terms of pain relief (p = 0.578) and patient satisfaction (p = 0.263). No severe adverse events were observed, although 20.7% (n = 9) of the PCA group experienced mild sedation compared with 7% (n = 3) of the control group.

CONCLUSIONS

PCA is at least as effective as titrated intravenous injections for relief of traumatic pain. It has considerable potential for use in the ED.

Transplantation of metanephroi to sites within the abdominal cavity

A novel approach to circumventing the shortage in transplantable donor organs is the use of embryonic primordia that develop inside the host. Previously published work has shown that transplantation of rat fetal kidney primordia (metanephroi) onto the omentum of adult rat hosts results in growth and development of the metanephroi into functioning kidney units capable of providing a measurable renal function. However, for anatomical and physiological reasons the omentum may not provide the ideal site for transplantation and may limit the maximum renal function that the transplants can achieve. We postulate that it may be possible to increase the renal function of the transplants by transplantation to sites with increased blood flow. To test this we transplanted rat embryonic day 15 metanephroi into the retroperitoneal fat adjacent to major blood vessels in the peritoneum of unilaterally nephrectomized rats; 21 days later the transplants were examined and suitable transplants connected to the host urinary system. Approximately 130 days later the glomerular filtration rate of the connected transplants was analyzed. Our results show that transplantation of metanephroi to the regions highlighted in this study results in an increased presence of urinary cysts, suggesting increased early renal function in the transplants compared to metanephroi transplanted onto the omentum, but most importantly we show that we can increase the renal function of the transplants to a level comparable with other renal therapies such as dialysis. This work suggests life-sustaining renal function could be achieved through transplantation of renal primordia.