Developing an online knowledge sharing platform and community of practice for health professionals: Experiences from C-WorKS developed in North East England and Yorkshire during COVID-19

BACKGROUND

Although knowledge sharing online has been recognised as an important strategy for health professionals to apply research findings to their practice, limited research exists on how to develop and implement these platforms to help facilitate collaboration and knowledge sharing.

OBJECTIVES

This study evaluated an online knowledge sharing platform and community of practice developed in the North East of England and Yorkshire during COVID-19 to support UK health and care professionals to reduce the impact of the wider consequences of COVID-19.

METHODS

Semi-structured interviews with stakeholders (n = 8) and users of C-WorKS (n = 13), followed by an online survey (n = 19) among a wider group of users to analyse knowledge use.

RESULTS

Interview and survey findings highlighted several strengths, weaknesses, opportunities and threats to support future development of online knowledge sharing platforms.

DISCUSSION

Online knowledge sharing supports six 'pillars' of successful research and innovation partnerships. This requires distributed forms of leadership and linking of different knowledge sharing strategies, and careful combination of platforms with communities of practice.

CONCLUSION

Online knowledge sharing provides pragmatic and timely strategies for health professionals in the UK to apply research evidence to their practice. Our study provides generalisable, practical insights in how to develop and implement a knowledge sharing platform.

Identification of tax options for high fat, sugar, salt foods for the HEALTHEI Project: a mixed-methods study

BACKGROUND

The health economic analysis incorporating effects on labour outcomes, households, environment, and inequalities (HEALTHEI) explores which food taxes would have greatest benefits to health, labour, and work outcomes; household expenditure; environmental sustainability; and inequalities within the UK food system. Work package 1 includes a rapid review and workshops, aiming to explore the effects of price increases in food and non-alcoholic beverages to facilitate the specification of food taxes and research design.

METHODS

In this mixed-methods study, we first did a rapid review to examine relevant published evidence. A preplanned framework ensured a systematic approach, in which we searched PubMed, HMIC, Scopus, Google, Mintel/Mintel Food and Drink, and Business Source Ultimate for papers published in English from Jan 1, 2010, to Nov 2, 2022. This review was followed by three online workshops (in March, 2023), which used interactive padlets to explore food systems, food taxation policy, tax rationales, and a rapid review infographic. 14 stakeholders from non-governmental organisations (n=10), academia (n=2), the Civil Service (n=1), and a local authority (n=1) took part (gender or ethnicity were not recorded). A stakeholder recruitment grid was developed to ensure representation across public sectors and disciplines of public health, nutrition, environment, and economics.

FINDINGS

The rapid review identified six tax options with a broadly positive impact on consumption and health (high fat, high sugar, high salt, "junk food", sugar-sweetened-beverages, and meats plus sugar-sweetened beverages). It generated five core rationales for a food tax: change consumption, reduce or prevent harm, change product affordability, raise revenue, and industry impact. Using the workshop feedback, health inequalities, economics, ease of implementation and animal welfare were additional key areas for a so-called real-world application of tax. Stakeholders questioned the taxes in the current economic and political climate.

INTERPRETATION

The work highlights the need to develop an impactful food tax option that encompasses the five core rationales identified in the findings. The workshops identified key areas to explore further to understand the feasibility, impact, and logistics of implementing future food taxes. Being unable to deliver workshops in person due to difficulties of participants travelling to London was a limitation. However, switching online allowed for varied and well attended workshops.

FUNDING

National Institute of Health Research (Ref: NIHR133927).

Assurance of Timely Access to Breast Cancer Diagnosis and Treatment by a Regional Breast Health Clinic Serving Both Urban and Rural-Remote Communities

In response to breast cancer diagnostic regional wait times exceeding both national and provincial standards and to symptomatic patient referrals for diagnostic mammography taking longer than abnormal screening mammography referrals, the Rae Fawcett Breast Health Clinic (RFBHC) was opened in 2017 in a mid-sized Canadian hospital serving both urban and rural-remote communities. We investigated whether the RFBHC improved wait times to breast cancer diagnosis, improved compliance with national and provincial breast cancer standards, and decreased the wait time disparity associated with referral source. Statistical analyses of wait time differences were conducted between patients who were diagnosed with breast cancer prior to and after the RFBHC establishment. Study group compliance with national and provincial standards and wait time differences by referral source were also analysed. A survey was administered to assess overall patient experience with the RFBHC and clinic wait times. RFBHC patients had a shorter mean wait to breast cancer diagnosis (24.4 vs. 45.7 days, p ≤ 0.001) and a shorter mean wait to initial breast cancer treatment (49.1 vs. 78.9 days, p ≤ 0.001) than pre-RFBHC patients. After the RFBHC establishment, patients who attended the RFBHC had a shorter mean wait time to breast cancer diagnosis (24.4 vs. 36.9 days, p = 0.005) and to initial treatment (49.1 vs. 73.1 days, p ≤ 0.001) than patients who did not attend the clinic. Compliance with national and provincial breast cancer standards improved after the RFBHC establishment and the wait time disparity between screening mammography referrals and symptomatic patient referrals decreased. Survey results indicate that the RFBHC is meeting patient expectations. We concluded that the establishment of a breast health clinic in a Canadian center serving urban and rural-remote communities improved breast diagnostic services.

Medication management surrounding transitions of care: A qualitative assessment of community pharmacists' preferences (MEMO TOC)

Background

Multiple medication changes during hospitalization increase the risk of errors upon discharge. Community pharmacists may face barriers to providing pharmaceutical care because of the lack of clinical information and communication from hospitals. Studies implementing handover to community pharmacists upon hospital discharge reported improved patient outcomes, but interventions were time-consuming.

Methods

One-on-one interviews and a focus group were conducted to identify community pharmacists' barriers to providing care to patients recently discharged from hospital and to determine their preferences for hospital discharge prescriptions. Transcripts were qualitatively analyzed using an inductive semantic approach.

Results

Four one-on-one interviews and an 8-participant focus group were conducted. Participants described barriers to providing care to discharged patients, including lack of communication, incomplete prescriptions, and limited clinical information. Participants identified that the most valuable information to include comprised laboratory values, hospital contact information and annotation of medication changes. These items would improve their abilities to provide timely and high-quality pharmaceutical care.

Interpretation

Our results were similar to prior literature identifying a lack of communication and clinical information as barriers to providing care to recently discharged patients. Unexpectedly, study participants did not rate medication indication as a strongly preferred information item.

Conclusions

Hospital discharge prescriptions lack information, which makes it challenging for community pharmacists to provide pharmaceutical care. Discharge prescriptions should include additional clinical information. Can Pharm J (Ott) 2020;153:xx-xx.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion

Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation. These films show the largest average grain size and the highest charge carrier density, as determined from electron microscopy and impedance spectroscopy analysis. We believe that the fast processing enabled by RTP makes this technique a preferred method for investigation of novel materials and architectures, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance.

Nonaneurysmal Perimesencephalic Hemorrhage Is Associated with Deep Cerebral Venous Drainage Anomalies: A Systematic Literature Review and Meta-Analysis

BACKGROUND AND PURPOSE

Mechanisms underlying bleeding in nonaneurysmal perimesencephalic SAH remain unclear. Previous investigators have suggested a relationship between nonaneurysmal perimesencephalic SAH and primitive venous drainage of the basal vein of Rosenthal. We performed a meta-analysis to evaluate the relation between primitive basal vein of Rosenthal drainage and nonaneurysmal perimesencephalic SAH.

MATERIALS AND METHODS

We performed a comprehensive literature search of all studies examining the prevalence of primitive basal vein of Rosenthal drainage in patients with aneurysmal SAH and nonaneurysmal perimesencephalic SAH. Data collected were primitive basal vein of Rosenthal drainage (direct connection of perimesencephalic veins into the dural sinuses instead of the Galenic system) in at least 1 cerebral hemisphere, normal bilateral basal vein of Rosenthal drainage systems, and the number of overall primitive venous systems in the nonaneurysmal perimesencephalic SAH and aneurysmal SAH groups. Statistical analysis was performed by using a random-effects meta-analysis.

RESULTS

Eight studies with 888 patients (334 with nonaneurysmal perimesencephalic SAH and 554 with aneurysmal SAH) and 1657 individual venous systems were included. Patients with nonaneurysmal perimesencephalic SAH were more likely to have a primitive basal vein of Rosenthal drainage in at least 1 hemisphere (47.7% versus 22.1%; OR, 3.31; 95% CI, 2.15-5.08; P < .01) and were less likely to have bilateral normal basal vein of Rosenthal drainage systems than patients with aneurysmal SAH (18.3% versus 37.4%; OR, 0.27; 95% CI, 0.14-0.52; P < .01). When we considered individual venous systems, there were higher rates of primitive venous systems in patients with nonaneurysmal perimesencephalic SAH than in patients with aneurysmal SAH (34.9% versus 15.3%; OR, 3.90; 95% CI, 2.37-6.43; P < .01).

CONCLUSIONS

Patients with nonaneurysmal perimesencephalic SAH have a higher prevalence of primitive basal vein of Rosenthal drainage in at least 1 hemisphere than patients with aneurysmal SAH. This finding suggests a venous origin of some nonaneurysmal perimesencephalic SAHs. A primitive basal vein of Rosenthal pattern is an imaging finding that has the potential to facilitate the diagnosis of nonaneurysmal perimesencephalic SAH.

Recovery of chronically lame dairy cows following treatment for claw horn lesions: a randomised controlled trial

A positively controlled, randomised controlled trial (RCT) was undertaken to test recovery of cows with claw horn lesions resulting in lameness of greater than two weeks duration. Cows on seven commercial farms were mobility scored fortnightly and selected by lameness severity and chronicity. Study cows all received a therapeutic trim then random allocation of: no further treatment (trim only (TRM)), plastic shoe (TS) or plastic shoe and NSAID (TSN). Recovery was assessed by mobility score at 42 (±4) days post treatment by an observer blind to treatment group. Multivariable analysis showed no significant effect of treatment with an almost identical, low response rate to treatment across all groups (Percentage non-lame at outcome: TRM – 15 per cent, TS – 15 per cent, TSN – 16 per cent). When compared with results of a similar RCT on acutely lame cows, where response rates to treatment were substantially higher, it can be concluded that any delay in treatment is likely to reduce the rate of recovery, suggesting early identification and treatment is key. Thirty-eight per cent of animals treated in this study were lame on the contralateral limb at outcome suggesting that both hindlimbs should be examined and a preventive or if necessary a therapeutic foot trim performed when lameness is identified particularly if the duration of lameness is unknown.

Dynamics and gravitational wave signature of collapsar formation

We perform 3+1 general relativistic simulations of rotating core collapse in the context of the collapsar model for long gamma-ray bursts. We employ a realistic progenitor, rotation based on results of stellar evolution calculations, and a simplified equation of state. Our simulations track self-consistently collapse, bounce, the postbounce phase, black hole formation, and the subsequent early hyperaccretion phase. We extract gravitational waves from the spacetime curvature and identify a unique gravitational wave signature associated with the early phase of collapsar formation.

On the origin, homologies and evolution of primate facial muscles, with a particular focus on hominoids and a suggested unifying nomenclature for the facial muscles of the Mammalia

The mammalian facial muscles are a subgroup of hyoid muscles (i.e. muscles innervated by cranial nerve VII). They are usually attached to freely movable skin and are responsible for facial expressions. In this study we provide an account of the origin, homologies and evolution of the primate facial muscles, based on dissections of various primate and non-primate taxa and a review of the literature. We provide data not previously reported, including photographs showing in detail the facial muscles of primates such as gibbons and orangutans. We show that the facial muscles usually present in strepsirhines are basically the same muscles that are present in non-primate mammals such as tree-shrews. The exceptions are that strepsirhines often have a muscle that is usually not differentiated in tree-shrews, the depressor supercilii, and lack two muscles that are usually differentiated in these mammals, the zygomatico-orbicularis and sphincter colli superficialis. Monkeys such as macaques usually lack two muscles that are often present in strepsirhines, the sphincter colli profundus and mandibulo-auricularis, but have some muscles that are usually absent as distinct structures in non-anthropoid primates, e.g. the levator labii superioris alaeque nasi, levator labii superioris, nasalis, depressor septi nasi, depressor anguli oris and depressor labii inferioris. In turn, macaques typically lack a risorius, auricularis anterior and temporoparietalis, which are found in hominoids such as humans, but have muscles that are usually not differentiated in members of some hominoid taxa, e.g. the platysma cervicale (usually not differentiated in orangutans, panins and humans) and auricularis posterior (usually not differentiated in orangutans). Based on our observations, comparisons and review of the literature, we propose a unifying, coherent nomenclature for the facial muscles of the Mammalia as a whole and provide a list of more than 300 synonyms that have been used in the literature to designate the facial muscles of primates and other mammals. A main advantage of this nomenclature is that it combines, and thus creates a bridge between, those names used by human anatomists and the names often employed in the literature dealing with non-human primates and non-primate mammals.

Improvements in the X-ray analytical capabilities of a scanning transmission electron microscope by spherical-aberration correction

A Nion spherical-aberration (Cs) corrector was recently installed on Lehigh University's 300-keV cold field-emission gun (FEG) Vacuum Generators HB 603 dedicated scanning transmission electron microscope (STEM), optimized for X-ray analysis of thin specimens. In this article, the impact of the Cs-corrector on X-ray analysis is theoretically evaluated, in terms of expected improvements in spatial resolution and analytical sensitivity, and the calculations are compared with initial experimental results. Finally, the possibilities of atomic-column X-ray analysis in a Cs-corrected STEM are discussed.

Efficacy of cyclosporin in the treatment of atopic dermatitis in dogs--combined results from two veterinary dermatology referral centres

OBJECTIVE

To evaluate the efficacy of cyclosporin in controlling the clinical signs associated with atopic dermatitis in dogs under Australian field conditions.

DESIGN

A multicentre prospective clinical investigation of the use of cyclosporin in 41 dogs with atopic dermatitis.

PROCEDURE

Dogs were treated with cyclosporin (5 mg/kg orally once daily with food) for 6 weeks. Four clinical parameters of severity of atopic dermatitis were measured on Day 0 and on Day 42 using a 0 to 4 scoring system. Individual variables were then combined to form a Global Score. Both client and clinician observed pruritus scores were combined to form a Pruritus Score. Pre- and post-treatment scores were statistically analysed. The difference in results between the two investigators was also recorded and analysed.

RESULTS

All dogs showed a marked reduction in pruritus and erythema during the 6-week treatment period. All dogs showed a significant (P < 0.001) improvement in clinical lesion scores and Global Score (P < 0.001). The mean percentage improvement in Global Score from Day 0 to Day 42 was 83.9%. The mean percentage improvement in Pruritus Score from Day 0 to Day 42 was 83%. The medication was well tolerated. Side effects such as vomiting, diarrhoea and soft stools were observed in four dogs. Another four dogs developed bacterial pyoderma during the trial period. There was no significant difference in results between the two centres.

CONCLUSION

Cyclosporin was well tolerated and efficacious in the symptomatic treatment of atopic dermatitis in dogs attending two veterinary dermatology referral centres in Australia, under Australian field conditions, when administered at 5 mg/kg/day for 6 weeks.

Possible risk factors in the development of eating disorders in overweight pre-adolescent girls

OBJECTIVES

To investigate concerns about weight, shape and eating, dietary restraint, self-esteem and symptoms of depression in overweight girls. To investigate the relationship between concerns and self-esteem and depressive symptoms in this group.

METHOD

Eighteen overweight girls and 18 average-weight girls completed the child version of the Eating Disorders Examination, the Harter Self-Perception Profile and the Short Moods and Feelings Questionnaire.

RESULTS

Overweight girls had more concerns about weight, shape and eating and attempted dietary restraint more often. They had more negative self-esteem related to their athletic competence, physical appearance and global self-worth and more symptoms of depression. There was an association between concerns and self-esteem based on physical appearance in the overweight group.

CONCLUSION

Overweight girls show some of the psychological features associated with the development of eating disorders, including a link between concerns and self-esteem based on physical appearance. This may help to explain why childhood obesity increases the risk of a later eating disorder.

On the Radii of Close-in Giant Planets

The recent discovery that the close-in extrasolar giant planet HD 209458b transits its star has provided a first-of-its-kind measurement of the planet's radius and mass. In addition, there is a provocative detection of the light reflected off of the giant planet tau Bootis b. Including the effects of stellar irradiation, we estimate the general behavior of radius/age trajectories for such planets and interpret the large measured radii of HD 209458b and tau Boo b in that context. We find that HD 209458b must be a hydrogen-rich gas giant. Furthermore, the large radius of a close-in gas giant is not due to the thermal expansion of its atmosphere but to the high residual entropy that remains throughout its bulk by dint of its early proximity to a luminous primary. The large stellar flux does not inflate the planet but retards its otherwise inexorable contraction from a more extended configuration at birth. This implies either that such a planet was formed near its current orbital distance or that it migrated in from larger distances (>/=0.5 AU), no later than a few times 107 yr of birth.

An Improved Red Spectrum of the Methane or T Dwarf SDSS 1624+0029: The Role of the Alkali Metals

A Keck II low-resolution spectrum shortward of 1 µm is presented for SDSS 1624+0029, the first field methane or T dwarf discovered in the Sloan Digital Sky Survey. Significant flux is detected down to the spectrum's short-wavelength limit of 6200 Å. The spectrum exhibits a broad absorption feature centered at 7700 Å, which we interpret as the K i lambdalambda7665, 7699 resonance doublet. The observed flux declines shortward of 7000 Å, most likely owing to the red wing of the Na i doublet. Both Cs i doublet lines are detected more strongly than in an earlier red spectrum. Neither Li i absorption nor Halpha emission are detected. An exploratory model fit to the spectrum suggests that the shape of the red spectrum can be primarily accounted for by the broad wings of the K i and Na i doublets. This behavior is consistent with the argument proffered by Burrows, Marley, & Sharp that strong alkali absorption is principally responsible for depressing T dwarf spectra shortward of 1 µm. In particular, there seems no compelling reason at this time to introduce dust or an additional opacity source in the atmosphere of the Sloan object. The width of the K i and strengths of the Cs i lines also indicate that the Sloan object is warmer than Gl 229B.

Supernova explosions in the Universe

During the lifetime of our Milky Way galaxy, there have been something like 100 million supernova explosions, which have enriched the Galaxy with the oxygen we breathe, the iron in our cars, the calcium in our bones and the silicon in the rocks beneath our feet. These exploding stars also influence the birth of new stars and are the source of the energetic cosmic rays that irradiate us on the Earth. The prodigious amount of energy (approximately 10(51), or approximately 2.5 x 10(28) megatonnes of TNT equivalent) and momentum associated with each supernova may even have helped to shape galaxies as they formed in the early Universe. Supernovae are now being used to measure the geometry of the Universe, and have recently been implicated in the decades-old mystery of the origin of the gamma-ray bursts. Together with major conceptual advances in our theoretical understanding of supernovae, these developments have made supernovae the centre of attention in astrophysics.

Comparison of intradermal testing and serum testing for allergen-specific IgE using monoclonal IgE antibodies in 84 atopic dogs

OBJECTIVE

To compare an ELISA measuring serum allergen-specific IgE with intradermal skin testing in canine atopic dermatitis.

PROCEDURE

Eighty-four dogs with the clinical diagnosis of atopic dermatitis underwent intradermal skin testing and serum testing for allergen-specific IgE. Tests were performed in a blinded fashion. Positive reactions were compared and the sensitivity and specificity of the serum test (using intradermal skin test as the standard) were determined overall and for individual allergen groups (grass pollens, weed pollens, tree pollens, house dust mites and fleas).

RESULTS

The sensitivity of the ELISA overall was 90.4%. Evaluating the individual allergen groups, the sensitivity for dust mite hypersensitivity was 95.1%, for fleas 85.4%, for tree pollens 84.3%, for grass pollens 95.1% and for weed pollens 96.4%. The specificity was 91.6% overall, for dust mites 96.3%, for fleas 92.7%, for tree pollens 95.2%, for grass pollens 94% and for weed pollens 80.7%.

CONCLUSION

The evaluated ELISA seemed reliable for the diagnosis of atopy in practice and can be recommended as a screening test prior to intradermal skin testing or for use in dogs when immunotherapy is not a therapeutic option.

Physiological sleep disturbance in children with atopic dermatitis: a case control study

It is generally acknowledged that sleep disturbance commonly complicates atopic dermatitis (AD), but the nature of this disturbance, including its physiologic aspects, has been little studied, especially in children. The results of home polysomnography (PSG) were compared for 20 school-age children with AD and sex- and age-matched healthy controls. The findings provided objective confirmation of disruption of sleep by both brief and longer awakenings associated with scratching episodes. Sleep efficiency was reduced but other sleep variables were not significantly affected. Home sleep studies offer advantages for further investigation of the factors involved in the link between AD and sleep disturbance, and the assessment of the contribution made by this disturbance to the daytime psychological problems of children with AD.

Regression pattern of beta human chorionic gonadotrophin in blood after chemotherapy for gestational trophoblastic neoplasia

Although beta human chorionic gonadotrophin (beta-HCG) is a clinically-useful tumour marker in gestational trophoblastic neoplasia, there is limited information on how serum beta HCG regresses in molar pregnancy and choriocarcinoma during chemotherapy. The study included 41 patients who had been treated by single- and multidrug regimens, and decay curves for regression of beta HCG in the circulation in these patients were fitted to the data. Thirty-three patients achieved a biochemical remission ('cured') by first-line chemotherapy; this gave an overall efficacy rate of 80%. The beta HCG decay curves convey useful information of the chemosensitivity of the tumour, and may assist in determining the time required for treatment and earlier change in treatment for the chemoresistant tumour.

Atmospheric, evolutionary, and spectral models of the brown dwarf Gliese 229 B

Theoretical spectra and evolutionary models that span the giant planet-brown dwarf continuum have been computed based on the recent discovery of the brown dwarf Gliese 229 B. A flux enhancement in the 4- to 5-micrometer wavelength window is a universal feature from jovian planets to brown dwarfs. Model results confirm the existence of methane and water in the spectrum of Gliese 229 B and indicate that its mass is 30 to 55 jovian masses. Although these calculations focus on Gliese 229 B, they are also meant to guide future searches for extrasolar giant planets and brown dwarfs.

Open-loop and closed-loop postural control mechanisms in Parkinson's disease: increased mediolateral activity during quiet standing

Stabilogram-diffusion analysis was used to gain insights into how idiopathic Parkinson's disease (IPD) affects the postural control mechanisms involved in maintaining erect stance. Twenty-two subjects with IPD and twenty-four healthy elderly subjects were studied under eyes-open, quiet-standing conditions. The postural control mechanisms in the parkinsonian subjects, compared to the healthy elderly, were characterized by an increase in the effective stochastic activity in the mediolateral direction. Mediolateral posturographic measures were also associated with a history of falls and poor performance on clinical measures of balance. It is hypothesized that the increase in mediolateral activity in subjects with IPD may reflect an attempt to maintain potentially stabilizing movements during quiet standing in the face of impaired movement in the anteroposterior direction. This study supports the notion that mediolateral instability is an important posturographic marker of functional balance impairment in the elderly.

The amniotic fluid embolism syndrome: 10 years' experience at a major teaching hospital

A review of the syndrome of amniotic fluid embolism (AFE) was carried out over a 10 year period, 1984-1993, at the Royal Women's Hospital, Brisbane. There were 9 patients with AFE, of whom 2 died--this gave an incidence of fatal AFE of 3.37 per 100,000 pregnancies at the hospital, in comparison with an incidence of 1.03 per 100,000 pregnancies over a 27-year period in Australia. The study revealed no identifiable risk factors in the characteristics of the patient or her baby, labour and delivery. Three of the patients did not undergo labour and in 4 of the 6 who did, the duration was less than 12 hours. The AFE syndrome could present before, during or after delivery; the common features were shock and respiratory distress, with coagulopathy occurring in 5 patients. Current views of predisposing factors, pathogenesis, diagnosis and management are discussed.

Age-related changes in open-loop and closed-loop postural control mechanisms

In an earlier posturographic investigation (Collins and De Luca 1993) it was proposed that open-loop and closed-loop control mechanisms are involved in the regulation of undisturbed, upright stance. In this study, stabilogram-diffusion analysis was used to examine how the natural aging process affects the operational characteristics of these control mechanisms. Stabilogram-diffusion analysis leads to the extraction of repeatable center-of-pressure (COP) parameters that can be directly related to the steady-state behavior and functional interaction of the neuromuscular mechanisms underlying the maintenance of erect posture. Twenty-five healthy young males (aged 19-30 years) and twenty-five elderly males (aged 71-80 years) who were free of major gait and postural disorders were included in the study. An instrumented force platform was used to measure the time-varying displacements of the COP under each subject's feet during quiet standing. The COP trajectories were analyzed as one-dimensional and two-dimensional random walks, according to stabilogram-diffusion analysis. Using this technique, it was demonstrated cross-sectionally that healthy aging is associated with significant changes in the 'quasi-static' dynamics of the postural control system. (It was also shown that more traditional posturographic analyses, i.e., summary statistics, were not sensitive enough to detect these age-related differences.) It was found that the steady-state behavior of the open-loop postural control mechanisms in the elderly is more positively correlated and therefore perhaps more unstable, i.e., the output of the overall system has a greater tendency to move or drift away from a relative equilibrium point over the short term. In contrast with this result, it was also found that the steady-state behavior of the closed-loop postural control mechanisms in the elderly is more negatively correlated and therefore perhaps more stable, i.e., over the longer term, there is an increased probability that movements away from a relative equilibrium point will be offset by corrective adjustments back towards the equilibrium position. In addition, it was demonstrated that the elderly utilize open-loop control schemes for longer time intervals and correspondingly larger COP displacements during periods of undisturbed stance. This result suggests that in the elderly there is a greater delay, on average, before closed-loop feedback mechanisms are called into play. Finally, it was shown that there is an increased heterogeneity of postural control abilities in healthy older adults.

Choroid plexus cysts in the fetal brain

Choroid plexus cysts may be detected in the fetal choroid plexus on routine second trimester ultrasound scanning. The presence of these cysts is associated with trisomy 18 (Edward syndrome) in 3.47% of cases and with trisomy 21 (Down syndrome) in 0.46% of cases. The cysts themselves almost always disappear by 23 weeks and are thought to be a normal developmental variant. The world literature experience would indicate that the size of the choroid plexus cyst and the presence of bilateral cysts has no bearing on the magnitude of risk of chromosomal abnormality; 76% of babies with trisomy 18 also have other dysmorphic features which may be detectable by ultrasound. It is strongly advised that genetic counselling be undertaken and amniocentesis be considered when choroid plexus cysts are identified in the fetus.

An Instability in Neutron Stars at Birth

Calculations with a two-dimensional hydrodynamic simulation show that a generic Raleigh-Taylor-like instability occurs in the mantles of nascent neutron stars, that it is possibly violent, and that the standard spherically symmetric models of neutron star birth and supemova explosion may be inadequate. Whether this "convective" instability is pivotal to the supemova mechanism, pulsar magnetic fields, or a host of other important issues that attend stellar collapse remains to be seen, but its existence promises to modify all questions concerning this most energetic of astronomical phenomena.

Characterization of GP120 binding to CD4 and an assay that measures ability of sera to inhibit this binding

There is evidence that the initial interaction between HIV-1 and the host that is essential for infection is the specific binding of the viral envelope glycoprotein, gp120, to the CD4 molecule found on certain T cells and monocytes. Most individuals infected with HIV develop antibodies against the gp120 protein. Although in vitro treatment of CD4+ T cells with mAb to a specific epitope of the CD4 molecule (T4a) blocks virus binding, syncytia formation, and infectivity, it is unclear if antibodies to gp120 from an infected individual that can inhibit the binding of gp120 to CD4 is in any way related to the clinical course of disease. Our present study characterizes the binding of 125I-labeled rgp120 to CD4+ cells, and describes an assay system that measures a potentially relevant form of immunity to HIV infection, i.e., the blocking of HIV binding to CD4+ cells. Optimal binding conditions included a 2-h incubation at 22 degrees C, 4 x 10(6) CD4+ cells, and 1 nM gp120. The dissociation constant (KD) for gp120 binding to cell surface CD4 was 5 nM, and was inhibited by soluble CD4 and by mAb to T4a but not to T3 or T4. For the binding inhibition assay, negative controls included healthy seronegatives, seronegatives with connective tissue diseases, patients with HTLV-1 disease, and patients infected with HIV-2. In studying over 100 sera, the assay was highly sensitive (98%) and specific (100%). The majority of HIV+ sera could inhibit binding at dilutions of 1/100 to 1/1000. No correlation was noted between binding inhibition (BI) titer in this assay and clinical stage of HIV infection. In addition, there was no correlation between BI titer and HIV neutralizing activity. The BI titer was correlated with the titer of anti-gp160 (r = 0.63) and the titer of anti-gp120 (r = 0.52) antibodies determined by Western blot dilution. As with neutralizing antibodies and other forms of immune response to HIV, it is unclear what role antibody blocking of HIV binding to CD4+ cells may play in active immunity to HIV in infected individuals. This activity may prove to have some value in protection against initial HIV infection and, thus, the assay may be of use in monitoring vaccine trials.

Characterization of GP120 binding to CD4 and an assay that measures ability of sera to inhibit this binding

There is evidence that the initial interaction between HIV-1 and the host that is essential for infection is the specific binding of the viral envelope glycoprotein, gp120, to the CD4 molecule found on certain T cells and monocytes. Most individuals infected with HIV develop antibodies against the gp120 protein. Although in vitro treatment of CD4+ T cells with mAb to a specific epitope of the CD4 molecule (T4a) blocks virus binding, syncytia formation, and infectivity, it is unclear if antibodies to gp120 from an infected individual that can inhibit the binding of gp120 to CD4 is in any way related to the clinical course of disease. Our present study characterizes the binding of 125I-labeled rgp120 to CD4+ cells, and describes an assay system that measures a potentially relevant form of immunity to HIV infection, i.e., the blocking of HIV binding to CD4+ cells. Optimal binding conditions included a 2-h incubation at 22 degrees C, 4 x 10(6) CD4+ cells, and 1 nM gp120. The dissociation constant (KD) for gp120 binding to cell surface CD4 was 5 nM, and was inhibited by soluble CD4 and by mAb to T4a but not to T3 or T4. For the binding inhibition assay, negative controls included healthy seronegatives, seronegatives with connective tissue diseases, patients with HTLV-1 disease, and patients infected with HIV-2. In studying over 100 sera, the assay was highly sensitive (98%) and specific (100%). The majority of HIV+ sera could inhibit binding at dilutions of 1/100 to 1/1000. No correlation was noted between binding inhibition (BI) titer in this assay and clinical stage of HIV infection. In addition, there was no correlation between BI titer and HIV neutralizing activity. The BI titer was correlated with the titer of anti-gp160 (r = 0.63) and the titer of anti-gp120 (r = 0.52) antibodies determined by Western blot dilution. As with neutralizing antibodies and other forms of immune response to HIV, it is unclear what role antibody blocking of HIV binding to CD4+ cells may play in active immunity to HIV in infected individuals. This activity may prove to have some value in protection against initial HIV infection and, thus, the assay may be of use in monitoring vaccine trials.

Anterior nongranulomatous uveitis: a seasonal variation

A review of 348 consecutive cases of nontraumatic uveitis seen in the Wills Eye Hospital emergency room between Jan 1, 1981, and Dec 31, 1981, was conducted. Patients who presented with an initial episode of anterior nongranulomatous uveitis, without obvious etiology by history or clinical examination, were further evaluated for epidemiologic clues suggestive of a pathogenesis. This group consisted of 121 patients. A statistical analysis for seasonal variation suggested an increased occurrence during the summer months (p .01).