POS1106 MEDIATORS OF THE EFFECT OF THERAPEUTIC EXERCISE ON PAIN AND FUNCTION IN PATIENTS WITH KNEE AND HIP OSTEOARTHRITIS; AN INDIVIDUAL PATIENT DATA MEDIATION STUDY FROM THE OA TRIAL BANK

Background

Currently, there is no cure for osteoarthritis (OA). Therapeutic exercise is recommended in all international guidelines to improve pain and function (1). However, randomised controlled trials (RCTs) investigating therapeutic exercise showed that, on average, effect sizes are small to moderate compared to non-exercise controls (2-3). Better knowledge about how therapeutic exercise works to improve pain and function could help improve the design and delivery of future therapeutic exercise interventions and potentially improve patient outcomes.

Objectives

To evaluate the mediating effects of 1) muscle strength, proprioception, and range of motion (ROM) among patients with knee OA, and 2) muscle strength among patients with hip OA, using the procedures established for Individual Participant Data (IPD) analyses by the OA Trial Bank.

Methods

Relevant IPD were sought from all published RCTs comparing therapeutic exercise to a non-exercise control group among people with knee and/or hip OA, using previously published methods (4). For each potential mediator separately, the effect of exercise on the absolute change in pain/function directly after the intervention was determined, controlling for the relative change in mediator under investigation and potential mediator-outcome confounders, using the ‘counterfactual framework’ (5). Next, the effect of exercise on the relative change in the mediator was determined. The percentage mediated was calculated by dividing the natural indirect effect by the total effect.

Results

We obtained IPD from 12 RCTs and 1407 participants (knee OA = 1113; hip OA n=294) that were eligible for inclusion in one or more mediation analyses. Therapeutic exercise showed a significant effect on the relative change in muscle strength in knee OA, but not for proprioception or ROM in knee OA, nor for muscle strength in hip OA. Of all mediators, only the change in muscle strength had a significant effect on the change in pain in knee OA, and on function in knee OA and in hip OA. The percentage mediated for each mediator and each outcome was small (5.3% or less, see Table 1).

Table 1.

Percentage mediated for all potential mediators, by outcome and joint.

Knee OAPainKnee OAFunctionHip OAPainHip OAFunctionMuscle strength2.4%2.3%absentabsentProprioceptionabsent0.2%--Range of motion1.8%5.3%--

‘absent’: no percentage mediated calculated, since direct and indirect effect had opposite directions.

‘-‘: factors not considered a potential mediator for therapeutic exercise in hip OA.

Conclusion

In the first IPD mediation analysis to our knowledge of this scale, muscle strength, proprioception and ROM did mediate the effect of therapeutic exercise for pain and function in knee OA, but only to a very small degree. We observed no such mediating effect of muscle strength for therapeutic exercise in patients with hip OA. The challenge remains to better understand the key mechanisms of action of therapeutic exercise for knee and hip OA, so that exercise interventions can be designed and delivered to target these and therewith optimise the effects for patients.

References

[1]Bierma-Zeinstra S, et al. Nonpharmacological and nonsurgical approaches in OA. Best Pract Res Clin Rheumatol. 2020 Apr;34(2):101564.

[2]Fransen M, et al. Exercise for osteoarthritis of the knee. Cochrane Database Syst Rev. 2015 Jan 9;1:CD004376.

[3]Fransen M, et al. Exercise for osteoarthritis of the hip. Cochrane Database Syst Rev. 2014 Apr 22(4):CD007912.

[4]Holden MA, et al. Subgrouping and TargetEd Exercise pRogrammes for knee and hip OsteoArthritis (STEER OA): a systematic review update and individual participant data meta-analysis protocol. BMJ Open. 2017 Dec 22;7(12):e018971.

[5]VanderWeele TJ, Vansteelandt S. Mediation Analysis with Multiple Mediators. Epidemiol Methods. 2014 Jan;2(1):95-115.

Acknowledgements

We thank all members of the OA Trial Bank Exercise Collaborative, who shared IPD with the OA Trial Bank/STEER OA for making this study possible.

Disclosure of Interests

Jos Runhaar Grant/research support from: Fellowship from the Foundation for Research in Rheumatology (FOREUM), Melanie Holden Grant/research support from: Grant from the Chartered Society of Physiotherapy Charitable Trust (grant no PRF/16/A07), and the National Institute for Health Research (NIHR) School of Primary Care Research (grant no 531), Miriam Hattle: None declared, Johny Quicke Grant/research support from: JQ is part-funded by an NIHR CRN West Midlands Research Scholarship and part funded by the Haywood Foundation, Richard Riley: None declared, Emma Healey Grant/research support from: part funded by the National Institute for Health Research (NIHR) Applied Research Collaboration (ARC) West Midlands., Danielle van der Windt: None declared, Krysia Dziedzic: None declared, Marienke Van Middelkoop: None declared, S.M.A. Bierma-Zeinstra Grant/research support from: OA Trial Bank received long-term funding by the Dutch Arthritis Association, Nadine Foster: None declared

Expert range maps of global mammal distributions harmonised to three taxonomic authorities

AIM

Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW).

LOCATION

Global.

TAXON

All extant mammal species.

METHODS

Range maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species).

RESULTS

Range maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use.

MAIN CONCLUSION

Expert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control.

Neutrophil function and cardiopulmonary bypass in humans. The effects of glucose and non-glucose containing bypass pump priming fluids

Defective polymorphonuclear neutrophil function during cardiopulmonary bypass (CPB) has been implicated as a cause of postoperative infection following open-heart surgery. Neutrophil function is known to be impaired in poorly controlled diabetics with elevations of blood glucose concentrations of the order which occur frequently during CPB when glucose containing priming fluids are used. Neutrophil function, as measured by bactericidal assay, and neutrophil and whole blood luminol dependent chemiluminescence, was studied in two groups of 1 2 patients undergoing coronary artery bypass graft surgery. Patients received either a glucose or non-glucose containing bypass pump-priming fluid. Postoperatively neutrophil luminol-dependent chemiluminescence was significantly increased in both groups (glucose prime groups p < 0.01, non-glucose prime group p < 0.01). Whole blood chemiluminescence was increased significantly intra and postoperatively in the glucose prime group ( p < 0.02, p < 0.02 respectively) but the increase was not significant in the non-glucose prime group. Bactericidal activity remained unchanged during and after surgery in both groups (mean bactericidal index intraoperatively 96.4 glucose group, 96.2 non-glucose group; postoperatively 99.7 glucose group, 99.7 non-glucose group). These data suggest that glucose containing bypass priming fluids do not modulate significantly the function of circulating neutrophils after CPB. Neutrophil function was not decreased after surgery, and other factors may be responsible for the reported higher incidence of bacterial infection after CPB.

Fish oil supplementation induces expression of genes related to cell cycle, endoplasmic reticulum stress and apoptosis in peripheral blood mononuclear cells: a transcriptomic approach

BACKGROUND

Fish oil supplementation has been shown to alter gene expression of mononuclear cells both in vitro and in vivo. However, little is known about the total transcriptome profile in healthy subjects after intake of fish oil. We therefore investigated the gene expression profile in peripheral blood mononuclear cells (PBMCs) after intake of fish oil for 7 weeks using transcriptome analyses.

DESIGN

In a 7-week, double-blinded, randomized, controlled, parallel-group study, healthy subjects received 8 g day(-1) fish oil (1.6 g day(-1) eicosapentaenoic acid + docosahexaenoic acid) (n = 17) or 8 g day(-1) high oleic sunflower oil (n = 19). Microarray analyses of RNA isolated from PBMCs were performed at baseline and after 7 weeks of intervention.

RESULTS

Cell cycle, DNA packaging and chromosome organization are biological processes found to be upregulated after intake of fish oil compared to high oleic sunflower oil using a moderated t-test. In addition, gene set enrichment analysis identified several enriched gene sets after intake of fish oil. The genes contributing to the significantly different gene sets in the subjects given fish oil compared with the control group are involved in cell cycle, endoplasmic reticulum (ER) stress and apoptosis. Gene transcripts with common motifs for 35 known transcription factors including E2F, TP53 and ATF4 were upregulated after intake of fish oil.

CONCLUSION

We have shown that intake of fish oil for 7 weeks modulates gene expression in PBMCs of healthy subjects. The increased expression of genes related to cell cycle, ER stress and apoptosis suggests that intake of fish oil may modulate basic cellular processes involved in normal cellular function.

A review of geometric transformations for nonrigid body registration

This paper provides a comprehensive and quantitative review of spatial transformations models for nonrigid image registration. It explains the theoretical foundation of the models and classifies them according to this basis. This results in two categories, physically based models described by partial differential equations of continuum mechanics (e.g., linear elasticity and fluid flow) and basis function expansions derived from interpolation and approximation theory (e.g., radial basis functions, B-splines and wavelets). Recent work on constraining the transformation so that it preserves the topology or is diffeomorphic is also described. The final section reviews some recent evaluation studies. The paper concludes by explaining under what conditions a particular transformation model is appropriate.

Clinically induced hypothermia: why chill your patient?

Clinically induced hypothermia is an evidence-based intervention strategy that can improve the neurological outcome of unconscious patients after sudden cardiac arrest. Until recently, clinically induced hypothermia has been primarily used during surgery as a mechanism of preserving cardiovascular and neurologic stability of patients. Current evidence suggests that early use of mild hypothermia therapy in select populations of patients improves survival and neurologic outcome postdischarge. While clinically induced hypothermia is beneficial as a treatment to preserve neurologic function, it is not without complications. The purpose of this article is to review current literature and evidence-based nursing practice implications for managing the induction of a hypothermic state in adult patients who remain comatose after initial resuscitation from sudden cardiac arrest. Physiologic benefits of hypothermia, complications, and nursing care considerations will be presented.

Medical image registration

Radiological images are increasingly being used in healthcare and medical research. There is, consequently, widespread interest in accurately relating information in the different images for diagnosis, treatment and basic science. This article reviews registration techniques used to solve this problem, and describes the wide variety of applications to which these techniques are applied. Applications of image registration include combining images of the same subject from different modalities, aligning temporal sequences of images to compensate for motion of the subject between scans, image guidance during interventions and aligning images from multiple subjects in cohort studies. Current registration algorithms can, in many cases, automatically register images that are related by a rigid body transformation (i.e. where tissue deformation can be ignored). There has also been substantial progress in non-rigid registration algorithms that can compensate for tissue deformation, or align images from different subjects. Nevertheless many registration problems remain unsolved, and this is likely to continue to be an active field of research in the future.

Anatomic and physiologic evaluation of upper extremity ischemia

This study assessed the accuracy of arteriography and laser Doppler perfusion imaging (LDPI) as predictors of digital ischemia and correlated upper extremity symptoms, function, and nutritional flow with arteriographic and laser Doppler assessments. Multiple-level occlusive disease was documented in 25 hands (23 patients) by arteriography. LDPI demonstrated one or more hypoperfused digits in 17 hands. Patient questionnaires were used to assess upper extremity symptoms, pain, cold sensitivity, and function. Spearman correlation coefficients indicated that arteriography is a poor indicator of nutritional perfusion as measured by LDPI. Neither arteriography or laser Doppler perfusion imaging served as an indicator of the severity of cold intolerance. However, upper extremity symptoms and functional status correlated with both laser Doppler measurements and the level of cold sensitivity. Laser Doppler perfusion imaging and arteriographic analysis provide complimentary data in the evaluation of upper extremity ischemia.

Arterial reconstruction for radial artery occlusion

This study was designed to detail the history and symptoms of symptomatic radial artery vaso-occlusive disease and to evaluate the results of radial artery reconstruction. Thirteen patients with symptomatic vaso-occlusive disease of the radial artery unresponsive to management by nonoperative modalities were managed with arterial reconstruction. All cases were treated with reversed interpositional vein grafting from the radial artery in the forearm (end-to-side) to the deep arch distally (end-to-end). Patients completed preoperative and postoperative assessments of symptoms and function, cold sensitivity (cold intolerance), and digital microvascular perfusion (isolated cold stress test evaluation with laser Doppler fluxmetry). At the follow-up examination all vascular grafts were patent, as determined by Allen's testing and Doppler ultrasound. The patients reported symptoms and functional status that demonstrated significant improvement following reconstruction. Microvascular evaluations demonstrated a significant improvement in digital microvascular perfusion as assessed by laser Doppler fluxmetry and digital temperature recordings with a resultant resolution of ischemic pain, numbness, and ulceration.

Voxel similarity measures for 3-D serial MR brain image registration

We have evaluated eight different similarity measures used for rigid body registration of serial magnetic resonance (MR) brain scans. To assess their accuracy we used 33 clinical three-dimensional (3-D) serial MR images, with deformable extradural tissue excluded by manual segmentation and simulated 3-D MR images with added intensity distortion. For each measure we determined the consistency of registration transformations for both sets of segmented and unsegmented data. We have shown that of the eight measures tested, the ones based on joint entropy produced the best consistency. In particular, these measures seemed to be least sensitive to the presence of extradural tissue. For these data the difference in accuracy of these joint entropy measures, with or without brain segmentation, was within the threshold of visually detectable change in the difference images.

The identification of cerebral volume changes in treated growth hormone-deficient adults using serial 3D MR image processing

PURPOSE

A pilot study to detect volume changes of cerebral structures in growth hormone (GH)-deficient adults treated with GH using serial 3D MR image processing and to assess need for segmentation prior to registration was conducted.

METHOD

Volume MR scans of the brain were obtained in five patients and six control subjects. Patients were scanned before and after 3 and 6 months of therapy. Control subjects were scanned at the same intervals. A phantom was used to quantify scaling errors. Second and third volumes were aligned with the baseline by maximizing normalized mutual information and transformed using sinc interpolation. Registration was performed with and without brain segmentation and correction of scaling errors. Each registered, transformed image had the original subtracted, generating a difference image. Structural change and effects of segmentation and scaling error correction were assessed on original and difference images. The radiologists' ability to detect volume change was also assessed.

RESULTS

Compared with control subjects, GH-treated subjects had an increase in cerebral volume and reduction in ventricular volume (p = 0.91 x 10(-3)). Scale correction and segmentation made no difference (p = 1 and p = 0.873). Structural changes were identified in the difference images but not in the original (p = 0.136). The radiologists detected changes >200 microm.

CONCLUSION

GH treatment in deficient patients results in cerebral volume changes detectable by registration and subtraction of serial MR studies but not by standard assessment of images. This registration method did not require prior segmentation.

Innervation density of the base of the palm

Cutaneous nerves of the palm were localized and quantitated by longitudinal axis, proximity to the distal palmar crease, and tissue layer to identify an incision that would avoid injury to the palmar branches of cutaneous nerves. Cadaveric palms (n = 10) harvested en bloc were fixed at physiologic tension and prepared using the celloidin method and hematoxylin-eosin staining. The cutaneous nerves of the palm were counted and classified by their size and location within each tissue layer and longitudinal axis as well as by proximal, middle, and distal locations within each axis. The mean number of large nerves identified within regions of the palm differed by tissue layer and longitudinal axis but not by longitudinal location within axes. The long/ring finger web space was characterized by the lowest innervation density; the index/long finger web space and ring finger axis were characterized by the greatest innervation density. An incision in the long/ring finger web space 2 cm proximal to Kaplan's cardinal line should result in injury to fewer nerves and reduce the incidence of painful neuromas during open carpal tunnel release.

Cloning and expression of the ApaLI, NspI, NspHI, SacI, ScaI, and SapI restriction-modification systems in Escherichia coli

The genes encoding the ApaLI (5'-GTGCAC-3'), NspI (5'-RCATGY-3'), NspHI (5'-RCATGY-3'), SacI (5'-GAGCTC-3'), SapI (5'-GCTCTTCN1-3', 5'-N4GAAGAGC-3') and ScaI (5'-AGTACT-3') restriction-modification systems have been cloned in E. coli. Amino acid sequence comparison of M.ApaLI, M.NspI, M.NspHI, and M.SacI with known methylases indicated that they contain the ten conserved motifs characteristic of C5 cytosine methylases. NspI and NspHI restriction-modification systems are highly homologous in amino acid sequence. The C-termini of the NspI and NlaIII (5'-CATG-3') restriction endonucleases share significant similarity. 5mC modification of the internal C in a SacI site renders it resistant to SacI digestion. External 5mC modification of a SacI site has no effect on SacI digestion. N4mC modification of the second base in the sequence 5'-GCTCTTC-3' blocks SapI digestion. N4mC modification of the other cytosines in the SapI site does not affect SapI digestion. N4mC modification of ScaI site blocks ScaI digetion. A DNA invertase homolog was found adjacent to the ApaLI restriction-modification system. A DNA transposase subunit homolog was found upstream of the SapI restriction endonuclease gene.

The effect of transdermal nicotine on digital perfusion in reformed habitual smokers

The effects of transdermal nicotine-assisted smoking cessation on digital perfusion and health-related quality of life were assessed in 10 chronic smokers. Components of digital blood flow were evaluated by digital temperature and laser Doppler fluxmetry before, during, and after a standardized cold challenge. Nutritional flow was measured by vital capillaroscopy; a quantitative perfusion profile was obtained by laser Doppler perfusion imaging. A battery of validated measures were used to evaluate health-related quality of life. The microvascular response of smokers was evaluated before smoking cessation and at 2 and 7 days after smoking cessation and was compared with the response of nonsmoking controls. Results demonstrated that a (1) cutaneous microvascular perfusion was lower in smokers than nonsmokers, (2) the acute administration of transdermal nicotine did not decrease cutaneous perfusion, (3) smoking cessation and transdermal nicotine normalized digital microvascular perfusion by 7 days, and (4) transdermal nicotine and smoking cessation did not negatively impact health-related quality of life.

Twelve-year experience with Carpentier-Edwards PERIMOUNT pericardial valve in the mitral position: a multicenter study

BACKGROUND AND AIMS OF THE STUDY

The study aim was to assess the durability of the Carpentier-Edwards PERIMOUNT pericardial bioprosthesis in the mitral position.

METHODS

This seven-center retrospective clinical study involved the follow up of 333 patients who underwent isolated mitral valve replacement and 102 patients who underwent double (mitral and aortic) valve replacement with the PERIMOUNT pericardial valve between 1984 and 1989. Mean patient age at implant was 60.7 +/- 11.6 years; 41.1% were males. The most common etiology was rheumatic heart disease (53.9%) and the most common mechanism mitral insufficiency. All patients but six were followed for an average of 7.2 +/- 3.6 years after surgery; total follow up was 3071.7 patient-years (pt-yr).

RESULTS

The total operative mortality rate was 7.6%; this included a valve-related mortality rate of 0.2%. The late mortality rate was 5.2% per pt-yr, of which 1.4% per pt-yr was considered valve-related. At 11 years, the overall actuarial survival rate was 53.3 +/- 2.8%, and actuarial freedom from valve-related death 83.9 +/- 2.6%. At follow up, 80% of patients were in NYHA class I or II, and 74% showed improvement. Twenty-eight incidences of deterioration requiring explant were observed. At 11 years the actuarial freedom from explant due to structural failure was 84.9 +/- 3.1%. Rates of structural failure decreased with age: the actuarial freedom from explant due to structural failure was 78.1 +/- 4.8% for patients aged < or = 60 years, 89.4 +/- 4.4% for those aged 61-70 years, and 100% for those aged over 71 years.

CONCLUSION

The Carpentier-Edwards PERIMOUNT pericardial bioprosthesis is a reliable choice when a tissue valve is required, especially in patients over 60 years of age.

A method for the confirmation and identification of drugs of misuse in urine using solid phase extraction and gas-liquid chromatography with mass spectrometry

A method is described for the confirmation/identification of a range of commonly misused drugs in urine samples. The method has been used for two years without problems for a range of purposes including hospital/clinic drugs of misuse screening and for toxicology in coroner's cases. Urine samples which have given a positive result on immunochemical screening for a particular drug group or groups (for example, opiates) can be processed with identification of the drugs present using a single procedure. Bond ElutCertify columns are used for the extraction of drugs from the samples followed by propionylation and gas chromatography with mass selective detection.

The effect of contusion and cryotherapy on skeletal muscle microcirculation

OBJECTIVE

The most common treatment of soft tissue contusions is ice application (cryotherapy). The physiological basis for this therapy is assumed to be cold-mediated vasoconstriction resulting in decreased edema formation and a reduction in overall morbidity. This proposed mechanism has not been tested. The present research examined the hypothesis that cryotherapy following contusion is effective because it reduces microvascular perfusion and subsequent edema formation.

EXPERIMENTAL DESIGN

The microcirculatory responses to contusion were studied with and without cryotherapy in a chronically instrumented rat model. Initial studies evaluated the immediate effects of cryotherapy on arteriolar and venular diameters and microvascular perfusion (using laser Doppler floxmetry). Variables were measured before and immediately after 20 minutes of cryotherapy. Two additional studies monitored the same microvascular parameters longitudinally in four sets of chronically instrumented animals. Groups of rats studied had contusion or sham contusion with ice treatment or no ice treatment. Measurements were performed repeatedly before and after treatment for 24 hours or 96 hours after contusion/sham contusion.

RESULTS

The acute microvascular effects of cryotherapy were vasoconstriction and decreased perfusion. However, when cryotherapy was used as a treatment following contusion/sham contusion, there were no long-lasting microvascular effects of cryotherapy either in the presence or absence of contusion.

CONCLUSIONS

These results indicate that cryotherapy of striated muscle following contusion does not reduce microvascular diameters or decrease microvascular perfusion. Alternate mechanisms of action for cryotherapy treatment need to be investigated.

The Tsp45I restriction-modification system is plasmid-borne within its thermophilic host

Thermus species YS45 harbors two small cryptic plasmids of 5.8 (pTsp45s) and approximately 12 kb (pTsp45I). Plasmid pTsp45s has been entirely sequenced, revealing three significant ORFs. In addition to a previously reported thermophilic plasmid-encoded replication protein (Rep), pTsp45s contains two genes for the Tsp45I methyltransferase (M.Tsp45I) and restriction endonuclease (Tsp45I). These two converging genes (tsp45IM and tsp45IR) overlap by 4 bp at their stop codons within an XbaI site. M.Tsp45I (413 aa, 47.0 kDa, recognizing 5'-GTSAC-3') is highly homologous to other m6A-methyltransferases, especially M.EcaI (recognizing 5'-GGTNACC-3'). Tsp45I (332 aa, 37.4 kDa, cleaving 5'-/GTSAC-3') is not homologous to M.Tsp45I, or to other restriction endonucleases. Recombinant Tsp45I is stably produced in E. coli, and cleaves DNA at 65 degrees C with the same specificity as the native enzyme. Therefore, the thermophilic Tsp45I restriction-modification system is plasmid-borne within its native host.

Probing the interactions of putidaredoxin with redox partners in camphor P450 5-monooxygenase by mutagenesis of surface residues

The role of surface amino acid residues in the interaction of putidaredoxin (Pdx) with its redox partners in the cytochrome P450cam (CYP101) system was investigated by site-directed mutagenesis. The mutated Pdx genes were expressed in Escherichia coli, and the proteins were purified and studied in vitro. Activity of the complete reconstituted P450cam system was measured, and kinetic parameters were determined. Partial assays were also conducted to determine the effect of the mutations on interactions with each redox partner. Some mutations altered interactions of Pdx with one redox partner but not the other. Other mutations affected interactions with both redox partners, suggesting some overlap in the binding sites on Pdx for putidaredoxin reductase and CYP101. Cysteine 73 of Pdx was identified as important in the interaction of Pdx with putidaredoxin reductase, whereas aspartate 38 serves a critical role in the subunit binding and electron transfer to CYP101.

Development and validation of a computerized screening test for personality disorders in DSM-III-R

The available self-report instruments designed to measure personality disorder (PD) are time-consuming to administer and/or score and can be impractical for routine clinical use. There is a need for a computerized method of personality assessment based on contemporary systems of classification. A computerized DSM-III-R-based questionnaire was developed and validated against the structured clinical interview for DSM-III-R Axis-II disorders on a sample of 60 subjects. The computerized test showed moderate validity as a diagnostic instrument (mean kappa coefficient = 0.47). With adjusted cut-off scores it was valid as a screening instrument (mean sensitivity = 0.87). Antisocial, borderline and avoidant PD scores were strongly correlated across measures and not subject to significant observer bias.

High-gain x-ray lasing at 11.1 nm in sodiumlike copper driven by a 20-J, 2-ps Nd:glass laser

Evidence of high gain pumped by recombination has been observed in the 5g-4f transition at 11.1 nm in sodiumlike copper ions with use of a 20-J 2-ps Nd:glass laser system. The time- and space-integrated gain coefficient was 8.8 +/- 1.4 cm(-1), indicating a single-transit amplification of ~60 times. This experiment has shown that 2 ps is the optimum pulse duration to drive the sodiumlike copper recombination x-ray lasing at 11.1 nm.

Measurement of small tissue volumes using Holden's apparatus

A reproducible method for the estimation of volumes of small tissue samples was needed to allow comparison of the biological activity of tissue explants and to relate symptom improvement to procedures such as adenoidectomy or polypectomy. Holden's apparatus, which utilizes fluid displacement between two chambers, was compared to displacement in a 20 ml syringe. Two observers made four readings each on 20 tissue samples (range 0.37 to 4.70 ml) using both methods for comparison. A two-way analysis of variance for replicated data gave an F ratio of 0.6885 (df = 19; p > 0.8) for Holden's apparatus, and an F ratio of 1.4307 (df = 19; p > 0.1) for the 20 ml syringe. The standard error of the mean for repeated readings on the same sample by an observer was 0.001 ml for Holden's apparatus and 0.014 ml for the syringe method. For accurate estimation of small tissue volumes within 0.01 ml we recommend Holden's apparatus.