Collaborative study for the establishment of Ph. Eur. Biological Reference Preparation for Human tetanus immunoglobulin batch 2

This publication describes the outcome of a project to develop a replacement European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) for Human tetanus immunoglobulin (TIg) as well as for the World Health Organization (WHO) International Standard (IS) for Tetanus Immunoglobulin, Human. Bulk TIg was kindly provided by a European manufacturer and was used to prepare the candidate standard. The candidate standard was freeze-dried and calibrated in an international collaborative study jointly co-ordinated by the Medicines & Healthcare products Regulatory Agency (MHRA) and the European Directorate for the Quality of Medicines & HealthCare (EDQM, Council of Europe). The results of this study show that there was good agreement between laboratories for the potency estimates obtained for the candidate standard relative to the current WHO IS/Ph. Eur. BRP. The study also demonstrated that the candidate standard is suitable for use in Ph. Eur. assays for potency testing of TIg products and there was good agreement in the potency estimates obtained using the different assay methods included in the study. Accelerated degradation studies performed at the MHRA over a period of 4 years suggest that the freeze-dried candidate standard will be very stable. The candidate standard was established as Ph. Eur. BRP for Human tetanus immunoglobulin, batch 2 with an assigned potency of 45 IU/ampoule. The same preparation was also adopted by the WHO Expert Committee on Biological Standardization (ECBS) to serve as the WHO 2nd IS for Tetanus Immunoglobulin, Human (13/240).

Collaborative study for the establishment of Ph. Eur. Biological Reference Preparation for Human tetanus immunoglobulin batch 2

This publication describes the outcome of a project to develop a replacement European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) for Human tetanus immunoglobulin (TIg) as well as for the World Health Organization (WHO) International Standard (IS) for Tetanus Immunoglobulin, Human. Bulk TIg was kindly provided by a European manufacturer and was used to prepare the candidate standard. The candidate standard was freeze-dried and calibrated in an international collaborative study jointly co-ordinated by the Medicines & Healthcare products Regulatory Agency (MHRA) and the European Directorate for the Quality of Medicines & HealthCare (EDQM, Council of Europe). The results of this study show that there was good agreement between laboratories for the potency estimates obtained for the candidate standard relative to the current WHO IS/Ph. Eur. BRP. The study also demonstrated that the candidate standard is suitable for use in Ph. Eur. assays for potency testing of TIg products and there was good agreement in the potency estimates obtained using the different assay methods included in the study. Accelerated degradation studies performed at the MHRA over a period of 4 years suggest that the freeze-dried candidate standard will be very stable. The candidate standard was established as Ph. Eur. BRP for Human tetanus immunoglobulin, batch 2 with an assigned potency of 45 IU/ampoule. The same preparation was also adopted by the WHO Expert Committee on Biological Standardization (ECBS) to serve as the WHO 2nd IS for Tetanus Immunoglobulin, Human (13/240).

Flow pattern-dependent mitochondrial dynamics regulates the metabolic profile and inflammatory state of endothelial cells

Endothelial mitochondria play a pivotal role in maintaining endothelial cell (EC) homeostasis through constantly altering their size, shape, and intracellular localization. Studies show that the disruption of the basal mitochondrial network in EC, forming excess fragmented mitochondria, implicates cardiovascular disease. However, cellular consequences underlying the morphological changes in the endothelial mitochondria under distinctively different, but physiologically occurring, flow patterns (i.e., unidirectional flow [UF] versus disturbed flow [DF]) are largely unknown. The purpose of this study was to investigate the effect of different flow patterns on mitochondrial morphology and its implications in EC phenotypes. We show that mitochondrial fragmentation is increased at DF-exposed vessel regions, where elongated mitochondria are predominant in the endothelium of UF-exposed regions. DF increased dynamin-related protein 1 (Drp1), mitochondrial reactive oxygen species (mtROS), hypoxia-inducible factor 1, glycolysis, and EC activation. Inhibition of Drp1 significantly attenuated these phenotypes. Carotid artery ligation and microfluidics experiments further validate that the significant induction of mitochondrial fragmentation was associated with EC activation in a Drp1-dependent manner. Contrarily, UF in vitro or voluntary exercise in vivo significantly decreased mitochondrial fragmentation and enhanced fatty acid uptake and OXPHOS. Our data suggest that flow patterns profoundly change mitochondrial fusion/fission events, and this change contributes to the determination of proinflammatory and metabolic states of ECs.

Premorbid Primary Headache and Vestibular and Oculomotor Baseline Assessments in Collegiate Athletes

OBJECTIVE

The purpose of this study was to determine the effects of premorbid headache status on vestibular and oculomotor baseline tests in collegiate club athletes.

DESIGN

Retrospective case-control study.

SETTING

Sport Concussion Laboratory.

PATIENTS OR PARTICIPANTS

Collegiate club athletes with a self-reported premorbid headache history (n = 32, 19.50 ± 1.98 years, and 31% women) and age-sex-sport-matched controls (n = 32, 19.56 ± 1.47 years, and 31% women) without a self-reported headache history were included.

INTERVENTIONS

Participants were grouped based on a self-reported headache history at baseline. Controls were randomly matched to self-reported headache participants by age, sex, and sport.

MAIN OUTCOME MEASURES

Vestibular/ocular motor screen (VOMS) baseline symptoms, symptom provocation, near point of convergence (NPC) distance, and King-Devick (K-D) test time were compared between groups.

RESULTS

Athletes with a self-reported headache history at baseline are 3.82 times more likely to have abnormal NPC scores (P = 0.032) and 4.76 times more likely to have abnormal K-D test times (P = 0.014) than those without a headache history. There was no difference in VOMS baseline symptoms or symptom provocation between groups (P > 0.05).

CONCLUSIONS

Club collegiate athletes with a headache history were more likely to screen as abnormal during a vestibular/ocular motor function assessment than athletes without a history of headaches. Healthcare professionals should screen for pre-existing headache during baseline concussion assessments before test interpretation.

CLINICAL RELEVANCE

A premorbid headache history at preseason baseline assessment may influence vestibular and oculomotor function, and care should be taken when interpreting these individuals' tests.

Differences in cervical kinesthesia between amateur athletes with and without a history of contact sport participation

Objective: Identify cervical sensorimotor function differences between amateur athletes with and without a history of contact sport participation. A secondary aim of the study was to explore the association between neck reposition error and previously identified injury risk factors.Design: Cross-sectional.Participants: 27 amateur campus recreation sport athletes with a history of contact sport participation and 20 amateur campus recreation sport athletes with no history of contact sport.Main Outcome Measures: Baseline signs and symptoms (S/S) number and severity, Neck Disability Index, total neck reposition error, maximum reposition error, cervical range of motion, and cervical isometric strength were then compared between independent factor groups (contact vs. non-contact).Results: Amateur sport athletes with a history of contact sport exposure exhibited 25.2% more total neck reposition error and 24.6% more maximum neck reposition error than athletes with no history of contact sport participation. S/S number (r2 = .12, F(2,44) = 6.2, p = .017) and S/S severity (r2 = .14, F(2,44) = 5.6, p = .02) were significantly correlated with total neck reposition error.Conclusions: Athletes with a history of contact sport participation exhibited greater cervical spine reposition error. The degree to which these sensory position-sense deficits increase risk of injury and long-term quality of life is unknown, but should be explored in future studies.

The Effect of Target Speed and Verbal Instruction on NPC Measures in a Young, Healthy, and Active Population

Purpose: Evaluate the effect of target speed and verbal instruction on near point of convergence (NPC) measurements in a young, healthy, and active population. Methods: NPC was measured in 20 individuals with three target speeds and two sets of verbal instruction. The target speeds used were 1 cm/s, 3 cm/s, 5 cm/s, and participant self-paced. The verbal instruction given was either to indicate when the target became “double” or “blurry”. Results: Paired-samples t-tests revealed significant differences between 5 cm/s (5.44 ± 2.01) and 1 cm/s (6.72 ± 2.39, p = .003), 3 cm/s (6.10 ± 2.36, p = .030) and self-paced (6.63 ± 2.26, p = .005). A significant difference (p < .001) was also found between the “double” (6.72 ± 2.39) and “blurry” (10.82 ± 3.08) conditions. Conclusion: For young, healthy and active individuals, target speed and verbal instruction matter when measuring NPC.

Hybrid membrane distillation reverse electrodialysis configuration for water and energy recovery from human urine: An opportunity for off-grid decentralised sanitation

The integration of membrane distillation with reverse electrodialysis has been investigated as a sustainable sanitation solution to provide clean water and electrical power from urine and waste heat. Reverse electrodialysis was integrated to provide the partial remixing of the concentrate (urine) and diluate (permeate) produced from the membrane distillation of urine. Broadly comparable power densities to those of a model salt solution (sodium chloride) were determined during evaluation of the individual and combined contribution of the various monovalent and multivalent inorganic and organic salt constituents in urine. Power densities were improved through raising feed-side temperature and increasing concentration in the concentrate, without observation of limiting behaviour imposed by non-ideal salt and water transport. A further unique contribution of this application is the limited volume of salt concentrate available, which demanded brine recycling to maximise energy recovery analogous to a battery, operating in a 'state of charge'. During recycle, around 47% of the Gibbs free energy was recoverable with up to 80% of the energy extractable before the concentration difference between the two solutions was halfway towards equilibrium which implies that energy recovery can be optimised with limited effect on permeate quality. This study has provided the first successful demonstration of an integrated MD-RED system for energy recovery from a limited resource, and evidences that the recovered power is sufficient to operate a range of low current fluid pumping technologies that could help deliver off-grid sanitation and clean water recovery at single household scale.

Influences of Mental Illness, Current Psychological State, and Concussion History on Baseline Concussion Assessment Performance

BACKGROUND

A student-athlete's mental state, including history of trait anxiety and depression, or current psychological state may affect baseline concussion assessment performance.

PURPOSE

(1) To determine if mental illness (anxiety, depression, anxiety with depression) influences baseline scores, (2) to determine if psychological state correlates with baseline performance, and (3) to determine if history of concussion affects Brief Symptom Inventory-18 (BSI-18) subscores of state anxiety, depression, and somatization.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A sample of 8652 collegiate student-athletes (54.5% males, 45.5% females) participated in the Concussion Assessment, Research and Education (CARE) Consortium. Baseline assessments included a demographic form, a symptom evaluation, Standardized Assessment of Concussion, Balance Error Scoring System, a psychological state assessment (BSI-18), and Immediate Post-concussion Assessment and Cognitive Test. Baseline scores were compared between individuals with a history of anxiety (n = 59), depression (n = 283), and anxiety with depression (n = 68) and individuals without a history of those conditions (n = 8242). Spearman's rho correlations were conducted to assess the relationship between baseline and psychological state subscores (anxiety, depression, somatization) (α = .05). Psychological state subscores were compared between individuals with a self-reported history of concussions (0, 1, 2, 3, 4+) using Kruskal-Wallis tests (α = .05).

RESULTS

Student-athletes with anxiety, depression, and anxiety with depression demonstrated higher scores in number of symptoms reported (anxiety, 4.3 ± 4.2; depression, 5.2 ± 4.8; anxiety with depression, 5.4 ± 3.9; no anxiety/depression, 2.5 ± 3.4), symptom severity (anxiety, 8.1 ± 9.8; depression, 10.4 ± 12.4; anxiety with depression, 12.4 ± 10.7; no anxiety/depression, 4.1 ± 6.9), and psychological distress in state anxiety (anxiety, 3.7 ± 4.7; depression, 2.5 ± 3.6; anxiety with depression, 3.8 ± 4.2; no anxiety/depression, 0.8 ± 1.8), depression (anxiety, 2.4 ± 4.0; depression, 3.2 ± 4.5; anxiety with depression, 3.8 ± 4.8; no anxiety/depression, 0.8 ± 1.8), and somatization (anxiety, 2.3 ± 2.9; depression, 1.8 ± 2.8; anxiety with depression, 2.2 ± 2.4; no anxiety/depression, 0.9 ± 1.7). A moderate positive relationship existed between all BSI-18 subscores and total symptom number (n = 8377; anxiety: r_s = 0.43, P < .001; depression: r_s = 0.42, P < .001; somatization: r_s = 0.45, P < .001), as well as total symptom severity (anxiety: r_s = 0.43, P < .001; depression: r_s = 0.41, P < .001; somatization: r_s = 0.45, P < .001). Anxiety, depression, and somatization subscores were greater among student-athletes that self-reported more concussions.

CONCLUSION

Clinicians should be cognizant that student-athletes with a history of trait anxiety, depression, and anxiety with depression may report higher symptom score and severity at baseline. Individuals with extensive concussion history may experience greater state anxiety, depression, and somatization.

Acute Changes in Plasma Total Tau Levels Are Independent of Subconcussive Head Impacts in College Football Players

Athletes in contact sports sustain repetitive subconcussive head impacts in a brief window, yet neurophysiological sequelae from repetitive subconcussion remain unclear. This prospective longitudinal study examined a relationship between changes in plasma Tau protein levels and subconcussive impact kinematic data in 23 Division I collegiate football players during a series of pre-season practices. Plasma measures for Tau and S100β proteins, symptom scores, and near point of convergence were obtained at pre-season baseline and pre-/post-practices. During each practice, impact frequency and linear and rotational head accelerations were recorded via an accelerometer-embedded mouth guard. There were significant elevations in plasma Tau levels at all post-practice time-points, compared with those of pre-practice and baseline levels. However, the highest degree of elevation in plasma Tau was observed after the first practice, for which players sustained the lowest number of hits and magnitudes for these hits. Subconcussive impact exposure during practice (e.g., head impact frequency and magnitude) did not predict increased plasma Tau levels. Concussion history and years of football experience also were unrelated to changes in plasma Tau levels. Increases in plasma Tau levels were associated with increases in S100β levels only after the first practice. There were no significant associations between changes in Tau levels, symptom scores, or near point of convergence. These data suggest that the changes in levels of circulating Tau protein were independent of subconcussive head impact exposure, pointing to the possibility that other factors may have played roles in changes in plasma Tau levels.

Concussion Recovery Phase Affects Vestibular and Oculomotor Symptom Provocation

Vestibular and oculomotor testing is emerging as a valuable assessment in sport-related concussion (SRC). However, their usefulness for tracking recovery and guiding return-to-play decisions remains unclear. Therefore the purpose of this study was to evaluate their clinical usefulness for tracking SRC recovery. Vestibular and oculomotor assessments were used to measure symptom provocation in an acute group (n=21) concussed≤10 days, prolonged symptoms group (n=10) concussed ≥16 days (median=84 days), healthy group (n=58) no concussions in >6 months. Known-groups approach was used with three groups at three time points (initial, 2-week and 6-week follow-up). Provoked symptoms for Gaze-Stabilization (GST), Rapid Eye Horizontal (REH), Optokinetic Stimulation (OKS), Smooth-Pursuit Slow (SPS) and Fast (SPF) tests, total combined symptoms scores and near point convergence (NPC) distance were significantly greater at initial assessment in both injury groups compared to controls. Injury groups improved on the King-Devick test and combined symptom provocation scores across time. The acute group improved over time on REH and SPF tests, while the prolonged symptoms group improved on OKS. A regression model (REH, OKS, GST) was 90% accurate discriminating concussed from healthy. Vestibular and ocular motor tests give valuable insight during recovery. They can prove beneficial in concussion evaluation given the modest equipment, training and time requirements. The current study demonstrates that when combined, vestibular and oculomotor clinical tests aid in the detection of deficits following a SRC. Additionally, tests such as NPC, GST, REH, SPS, SPF OKS and KD provide valuable information to clinicians throughout the recovery process and may aid in return to play decisions.

Responsiveness of the active wrist joint position sense test after distal radius fracture intervention

STUDY DESIGN

Prospective cohort study.

INTRODUCTION

The active wrist joint position sense (JPS) test has been determined to be a clinically useful test for assessing wrist sensorimotor (SM) status after distal radius fracture (DRF). Its responsiveness is yet to be determined.

PURPOSE OF THE STUDY

Primary study aim was to determine the active wrist JPS test responsiveness to detect change in wrist SM status at 8 and 12 weeks after DRF treatment intervention. Secondary aims were to compare group (nonsurgical, surgical, high, and low pain) test responsiveness; compare pain-level group participants test scores; determine the relationship between test minimal clinically important difference (MCID) value and function; compare functional outcomes across assessment times; and determine the Patient Global Impression of Change Scale intrarater reliability.

METHODS

A total of 33 male and female participants were tested at baseline, 8, and 12 weeks after nonsurgical (n = 13) and surgical (n = 20) DRF treatment interventions. Distribution-based analysis encompassed both group- (ie, effect size, standardized response mean) and individual-based (ie, minimum detectable change) statistical indices. Anchor-based analysis determined the MCID value by linking test scores to the Patient Global Impression of Change Scale.

RESULTS

The active wrist JPS test is highly responsive based on effect size (8 weeks = 1.53 and 12 weeks = 2.36) and standardized response mean (8 weeks = 1.57 and 12 weeks = 2.14). Statistically significant minimum detectable change values were 4.28° and 4.94° at 8 and 12 weeks, respectively. Clinically meaningful MCID values were 5.00° and 7.09° at 8 and 12 weeks, respectively. Between treatment type and pain-level group responsiveness levels were not significantly different. High-pain participants demonstrated significantly greater JPS deficit. Test MCID values and function were significantly associated.

DISCUSSION

This is the first study to determine the active wrist JPS test responsiveness as reflected by its group- and individual-based statistical indices following DRF surgical and non-surgical interventions among low- and high-pain level participants. The statistical analysis approach, which was used to determine the aforementioned variables of the active wrist JPS test, is consistent with current research. This study's strengths included its design, methodology, and statistical approach. The study findings must be interpreted, however, within the content of several methodological limitations.

CONCLUSIONS

The active wrist JPS test was determined to be highly responsive to detect wrist SM status change at 8 and 12 weeks regardless of treatment type or pain level. Clinicians can use this test with confidence to measure clinically meaningful SM impairment after DRF treatment.

LEVEL OF EVIDENCE

2b.

Association of Football Subconcussive Head Impacts With Ocular Near Point of Convergence

IMPORTANCE

An increased understanding of the relationship between subconcussive head impacts and near point of convergence (NPC) ocular-motor function may be useful in delineating traumatic brain injury.

OBJECTIVE

To investigate whether repetitive subconcussive head impacts during preseason football practice cause changes in NPC.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, observational study of 29 National Collegiate Athletic Association Division I football players included baseline and preseason practices (1 noncontact and 4 contact), and postseason follow-up and outcome measures were obtained for each time. An accelerometer-embedded mouthguard measured head impact kinematics. Based on the sum of head impacts from all 5 practices, players were categorized into lower (n = 7) or higher (n = 22) impact groups.

EXPOSURES

Players participated in regular practices, and all head impacts greater than 10g from the 5 practices were recorded using the i1Biometerics Vector mouthguard (i1 Biometrics Inc).

MAIN OUTCOMES AND MEASURES

Near point of convergence measures and symptom scores.

RESULTS

A total of 1193 head impacts were recorded from 5 training camp practices in the 29 collegiate football players; 22 were categorized into the higher-impact group and 7 into the lower-impact group. There were significant differences in head impact kinematics between lower- and higher-impact groups (number of impacts, 6 vs 41 [lower impact minus higher impact = 35; 95% CI, 21-51; P < .001]; linear acceleration, 99g vs 1112g [lower impact minus higher impact= 1013; 95% CI, 621 - 1578; P < .001]; angular acceleration, 7589 radian/s2 vs 65 016 radian/s2 [lower impact minus higher impact= 57 427; 95% CI , 31 123-80 498; P < .001], respectively). The trajectory and cumulative burden of subconcussive impacts on NPC differed by group (F for group × linear trend1, 238 = 12.14, P < .001 and F for group × quadratic trend1, 238 = 12.97, P < .001). In the higher-impact group, there was a linear increase in NPC over time (B for linear trend, unstandardized coefficient [SE]:  0.76 [0.12], P < .001) that plateaued and resolved by postseason follow-up (B for quadratic trend [SE]: -0.06 [0.008], P < .001). In the lower-impact group, there was no change in NPC over time. Group differences were first observed after the first contact practice and remained until the final full-gear practice. No group differences were observed postseason follow-up. There were no differences in symptom scores between groups over time.

CONCLUSIONS AND RELEVANCE

Although asymptomatic, these data suggest that repetitive subconcussive head impacts were associated with changes in NPC. The increase in NPC highlights the vulnerability and slow recovery of the ocular-motor system following subconcussive head impacts. Changes in NPC may become a useful clinical tool in deciphering brain injury severity.

Subconcussive Impact-Dependent Increase in Plasma S100β Levels in Collegiate Football Players

The current study investigates whether repetitive subconcussive impacts cause changes in plasma S100β levels, and also tests the associations between S100β changes and frequency/magnitude of impacts sustained. This prospective study of 22 Division-I collegiate football players included baseline and pre-season practices (one helmet-only and four full-gear). Blood samples were obtained and assessed for S100β levels at baseline and pre- to post-practices; symptom scores were assessed at each time-point. An accelerometer-embedded mouthguard was employed to measure the number of impacts (hits), peak linear acceleration (PLA), and peak rotational acceleration (PRA). Because we observed a distinct gap in impact exposure (hits, PLA, and PRA), players were clustered into lower (n = 7) or higher (n = 15) impact groups based on the sum of impact kinematics from all five practices. S100β levels significantly changed across the study duration. Although S100β levels remained stable from baseline to all pre-practice values, statistically significant acute increases in S100β levels were observed in all post-practice measures compared with the respective pre-practice values (range: 133-246% in the overall sample). Greater number of hits, sum of PLA, and sum of PRA were significantly associated with greater acute increases in S100β levels. There were significant differences in head impact kinematics between lower and higher impact groups (hits, 6 vs. 43 [M_lower - M_higher = 35, p < 0.001]; PLA, 99.4 vs. 1148.5 g [M_lower - M_higher = 1049.1, p < 0.001]; PRA, 7589 vs. 68,259 rad/s² [M_lower - M_higher = 60,670, p < 0.001]). Players in the higher impact group showed consistently greater increases in plasma S100β levels, but not symptom scores, at each post-practice than the lower impact group. Collectively, these data suggest that although players continued to play without noticeable change in symptoms, a brain-enriched serological factor suggests an acute burden from head impacts. Assessing the effects of repetitive subconcussive head impacts on acute changes in S100β levels may be a clinically useful blood biomarker in tracking real-time acute brain damage in collegiate football players.

Physical activity levels and quality of life relate to collagen turnover and inflammation changes after running

The purpose of this study was to determine whether an association existed between self-reported symptom and function scores and tissue turnover or inflammatory biomarker changes after a running bout among individuals with and without an acute knee-injury history. A pre-test/post-test prospective cohort study design (Level II) of 22 participants was conducted. Eleven physically active individuals with a history of anterior cruciate ligament surgery and/or meniscus surgery within 4 years of study participation were matched to 11 healthy control participants. All participants completed self-reported outcome measures (Knee Osteoarthritis Outcomes Score and Tegner activity level) assessing knee symptoms and functional levels prior to the run. Blood samples were taken both pre- and post-30-minute run at a prescribed pace on a treadmill to determine serum biomarker concentration changes. Tegner activity levels were inversely related to type II collagen/type II collagen synthesis marker ratio biomarker changes after the run (r = -0.45, p = 0.01). Quality-of-life scores pre-exercise were inversely related to interleukin-1β changes after the run (r = -0.50, p = 0.02). No other correlation coefficients were statistically significant (r = -0.39 to 0.36). Ultimately, individuals with lower activity and quality-of-life scores experienced greater increases in collagen turnover and inflammation after a running bout, respectively. A gradual increase in activity (e.g., frequency, duration, intensity) may be warranted in this group prior to returning to activities that involve running. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:612-617, 2017.

Cervical Injury Assessments for Concussion Evaluation: A Review

BACKGROUND

A concussion is a complex pathophysiologic process that is induced by biomechanical forces and affects the brain. Cervical injuries and concussion can share similar mechanisms and nearly identical symptoms or causes. Therefore, symptoms or causes alone may be insufficient to differentiate between patients with a concussion and patients with cervical injuries.

OBJECTIVE

To demonstrate the homogeneous causes and symptoms observed in patients with a concussion and patients with cervical injury and to provide information on clinical tests that can differentiate cervical injury from pathologic conditions of vestibular or central origin.

SUMMARY

Given that concussion and cervical injury share similar causes and symptoms, this information alone may be insufficient to diagnose a concussion. Clinical assessments, such as the cervical joint-reposition error test, smooth-pursuit neck-torsion test, head-neck differentiation test, cervical flexion-rotation test, and physical examination of the cervical spine, can be performed after a head and neck pathomechanical event to identify the presence of cervical injury. Differentiating between a concussion and cervical injury is clinically vital for timely and appropriate evidence-based treatment.

CONCLUSIONS

Specific clinical tests should be used after a head and neck pathomechanical event to differentiate between symptoms due to a concussion and cervical injury. Continued research on the clinical utility of the 5 identified cervicogenic tests is also recommended.

Assessing subacute mild traumatic brain injury with a portable virtual reality balance device

PURPOSE

Balance impairment is a common sensorimotor symptom in mild traumatic brain injury (mTBI). We designed an affordable, portable virtual reality (VR)-based balance screening device (Virtual Environment TBI Screen [VETS]), which will be validated relative to the Neurocom Sensory Organization Test (SOT) to determine if it can replace commonly used postural assessments.

METHODS

This preliminary study examines healthy adults (n = 56) and adults with mTBI (n = 11). Participants performed six upright postural tasks on the VETS and the SOT. Analysis of variance was used to determine between-group differences. Pearson's correlations were used to establish construct validity. Known-groups approach was used to establish classification accuracy.

RESULTS

The mTBI cohort performed significantly worse than the healthy cohort on the new device (p = 0.001). The new device has 91.0% accuracy and an ROC curve with a significant area-under-the-curve (AUC = 0.865, p < 0.001). Conditions with dynamic visual stimulation were the most sensitive to health status. The SOT had an 84.8% accuracy and AUC =0.703 (p = 0.034).

CONCLUSIONS

The new VR-based device is a valid measure for detecting balance impairment following mTBI and can potentially replace more expensive and cumbersome equipment. Assessments that test visual-vestibular processing, such as VETS, increase sensitivity to mTBI-related balance deficits, which can be used to guide rehabilitation. Implications for rehabilitation Emerging technology using virtual reality can be economically integrated into the clinical setting for easy testing of postural control in neurologically impaired populations. Tailoring postural assessments to include tasks that rely on visual and vestibular integration will increase the accuracy of detecting balance impairment following mild traumatic brain injury.

Vestibular Dysfunction after Subconcussive Head Impact

Current thinking views mild head impact (i.e., subconcussion) as an underrecognized phenomenon that has the ability to cause significant current and future detrimental neurological effects. Repeated mild impacts to the head, however, often display no observable behavioral deficits based on standard clinical tests, which may lack sensitivity. The current study investigates the effects of subconcussive impacts from soccer heading with innovative measures of vestibular function and walking stability in a pre- 0-2 h, post- 24 h post-heading repeated measures design. The heading group (n = 10) executed 10 headers with soccer balls projected at a velocity of 25 mph (11.2 m/sec) over 10 min. Subjects were evaluated 24 h before, immediately after, and 24 h after soccer heading with: the modified Balance Error Scoring System (mBESS); a walking stability task with visual feedback of trunk movement; and galvanic vestibular stimulation (GVS) while standing with eyes closed on foam. A control group (n = 10) followed the same protocol with no heading. The results showed significant decrease in trunk angle, leg angle gain, and center of mass gain relative to GVS for the heading group compared with controls. Medial-lateral trunk orientation displacement and velocity during treadmill walking increased immediately after mild head impact for the heading group compared with controls. Controls showed an improvement in mBESS scores over time, indicating a learning effect, which was not observed with the heading group. These results suggest that mild head impact leads to a transient dysfunction in vestibular processing, which deters walking stability during task performance.

ASSOCIATION BETWEEN ROWING INJURIES AND THE FUNCTIONAL MOVEMENT SCREEN™ IN FEMALE COLLEGIATE DIVISION I ROWERS

BACKGROUND

48 percent of rowing injuries are due to overuse and occur more often in females. The Functional Movement Screen™ (FMS) is a screening tool utilized to identify the risk of musculoskeletal injury in field sport athletes based on movement patterns. It has not been used to identify risk of injury in rowing.

OBJECTIVES

The purpose of this study was to determine if the scores on the FMS™ are predictors of incidence of all injuries, including low back pain (LBP) in female collegiate rowers during one season of rowing.

METHODS

Prospective cohort conducted in a clinical setting. Thirty-seven Division I female collegiate rowers (33 rowers and 4 coxswains). Investigators performed pre-season FMS™ screening and collected demographic data, rowing data, and Oswestry Low Back Pain questionnaire scores. Based on FMS™ scores, individuals were grouped high or low risk for injury. Injury reports and patient complaints of LBP over the course of a season were compared to FMS™ group.

RESULTS

Those in the high risk group were significantly more likely to experience LBP during the season (p=.036) and reported a 58 percent greater mean in years of rowing experience (p=.008) than individuals in the low risk group. Those with a history of LBP were six times more likely to experience LBP during season (p=.027).

DISCUSSION

The FMS™ indicated that rowers at a high risk of injury and more years of rowing experience, have a higher probability of sustaining LBP. Results could be due to chronic overuse associated with the rowing motion. Low back pain was evident in 25 out of the 37 participants over the season.

CONCLUSION

While the FMS™ has been proven to predict injury in field athletes, there was no statistically significant evidence to support prediction of a reported time loss injury in female collegiate rowers. However, it did indicate a higher likelihood for subjective report of low back pain.

LEVEL OF EVIDENCE

Cohort study, level 2b.

Effect of target type on near point of convergence in a healthy, active, young adult population

Purpose: Measuring near point of convergence (NPC) has recently emerged as a concussion assessment tool. Differences in administration of the test can be seen within the literature, which may affect results and normative values. There has been little investigation examining if clinically accessible target types affects NPC and no examination of NPC in a healthy, active young adult population. Methods: NPC was measured in 39 subjects using 5 different targets two times each with an accommodative ruler. Results: NPC ranged from 1.5-10cm in this population with an overall mean of 5.9+-1.6 cm. There were significant differences between the middle sized font and the line (p = .024) and pen (p = .047), and also between the largest sized font and the line (p = .026). Conclusion: For physically active young adults, the measurement of NPC is affected by target type.

A descriptive study on wrist and hand sensori-motor impairment and function following distal radius fracture intervention

STUDY DESIGN

Descriptive cross-sectional design.

INTRODUCTION

Wrist and hand sensori-motor impairment have been observed after distal radius fracture (DRF) treatment. This impairment and its relationship to function lack research.

PURPOSE OF THE STUDY

The primary aim of this exploratory study was to determine the magnitude of wrist and hand sensori-motor impairment following surgical and non-surgical treatment among older patients following DRF. Secondary aims were to determine the relationship between wrist and hand sensori-motor impairment with function and pain as well as the relationships among wrist and hand sensori-motor impairment and function and age following DRF.

METHODS

Ten Test (TT), active joint position sense (JPS), electromyography (EMG), computerized hand-grip dynamometer (CHD), and the Patient-Rated Wrist Evaluation (PRWE) were used to assess twenty-four female participants 8 weeks following DRF treatment and their 24 matched-control healthy counterparts on wrist and hand sensibility, proprioception, muscle recruitment, grip force, muscle fatigue, and functional status.

RESULTS

Participants following DRF demonstrated significantly (p < .05) greater sensory (i.e., JPS, TT), and motor (i.e., EMG, CHD) deficits than their control counterparts. A significantly higher functional deficit (i.e., PRWE) also existed among participants following DRF than the control group. Participants following surgical and non-surgical DRF treatment were found to be statistically different only on total grip force. Group differences on JPS and total grip force revealed the strongest effect size with the highest correlations to PRWE. EMG and muscle fatigue ratio group differences revealed a weaker effect size with a fair degree of correlation to PRWE. Pain significantly correlated with sensori-motor function. Age did not correlate with any measured variable.

CONCLUSIONS

Significant wrist and hand sensori-motor impairment and functional deficits among older females 8 weeks following DRF surgical and non-surgical interventions were revealed. JPS and total grip force were the most clinically meaningful tests for assessing the sensori-motor status as well as explaining functional disability and pain levels for these patients.

LEVEL OF EVIDENCE

2c.

Acute changes in postural control after soccer heading

This study intended to determine if an acute bout of soccer heading alters postural control and pronounced self-reported symptoms of cerebral concussion. Collegiate soccer players were randomly assigned to one of 2 groups. Each participant completed a baseline postural control assessment prior to heading. Participants either simulated (control group; CG) or performed (experimental group; EG) 10 headers at 11.2 m/s in 10 min. The postural assessment was repeated post heading at hrs 1, 24, and 48. The postural control parameter assessed was the root mean square (RMS) of the center of mass (COM). COM RMS were calculated for the anterior-posterior (AP) and medial-lateral (ML) time series. Compared to the CG, for the AP and ML time series COM RMS values were significantly higher in the EG at hr 24 (p <0.05). An acute bout of heading results in quantifiable alterations in postural control that are detectable 24 h post heading and dissipate within an additional 24 h. The significant findings may be due to the dynamic postural control assessment that incorporated robust discordant environmental conditions.

Calibration of the Ph. Eur. Biological Reference Preparation (BRP) for tetanus vaccine (adsorbed) batch 3

A joint collaborative study was organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM) and the World Health Organization (WHO)/National Institute for Biological Standards and Control (NIBSC) to establish replacement batches for the European Pharmacopoeia (Ph. Eur.) Tetanus Vaccine (adsorbed) Biological Reference Preparation (BRP) batch 2 and for the WHO 3rd International Standard (IS) for Tetanus toxoid (adsorbed). Two freeze-dried stabilised tetanus vaccine (adsorbed) candidate preparations (Preparation A, 08/218 and Preparation B, 08/102) were calibrated against the current 3rd IS/BRP batch 2 (Preparation C) using challenge methods in guinea pigs and mice as described in the Ph. Eur. general chapter 2.7.8. Assay of tetanus vaccine (adsorbed). They were also assayed by serology methods. The WHO 2nd IS for Tetanus toxoid adsorbed (TEXA-2) was additionally included in the sample panel as Preparation D. Thirty-four laboratories (regulatory organisations and manufacturers) from 22 countries participated in the collaborative study. The majority of participants performed 2 independent challenge tests. Nine laboratories performed challenge assays in guinea pigs and 30 laboratories performed challenge assays in mice. Eight laboratories performed serology in guinea pigs and 1 laboratory performed serology in mice. For Preparation A, the geometric mean (GM) potency estimate (with 95 % confidence interval (CI)) in guinea pigs for all laboratories that provided valid results (n = 6) was 488.5 (354.2-673.6) IU/ampoule. For valid mouse assays (n = 25) the GM potency (with 95 % CI) was 259.8 (223.5-302.0) IU/ampoule. The inter-laboratory geometric coefficient of variation (GCV) was 36 % for guinea pig assays and 45 % for mouse assays. This compared favourably with the calibration of the 3rd IS/BRP batch 2 where the inter-laboratory GCV was 36 % and 42 % in guinea pigs and mice, respectively. For Preparation B, the GM potency estimate (with 95 % CI) in guinea pigs for all laboratories that provided valid results (n = 6) was 107.9 (64.1-181.7) IU/ampoule. For valid mouse assays (n = 24) the GM potency (with 95 % CI) was 147.9 (126.3-173.1) IU/ampoule. The inter-laboratory GCV was 64.3 % for guinea pig assays and 45.2 % for mouse assays. From the collaborative study, Preparation A appeared more suitable to be the replacement Ph. Eur. BRP as it is similar to the Tetanus vaccine (adsorbed) BRP batch 2, except for nature of the stabiliser. Preparation A was confirmed to have higher potency, readily detectable tetanus toxoid, and confirmed satisfactory stability and performance in challenge assays. Preparation A was adopted in January 2011 by the Ph. Eur. Commission as the Tetanus vaccine (adsorbed) BRP batch 3, with assigned potencies of 490 IU/ampoule in the guinea pig challenge assay and of 260 IU/ampoule in the mouse challenge assay. The same Preparation A was adopted in October 2010 as the WHO 4th IS for Tetanus toxoid (adsorbed), with the assigned activity of 490 IU/ampoule from guinea pig challenge assays. A follow-up study (reporting study) was organised by the EDQM to assess the impact of the potency assigned to the BRP batch 3 for mouse challenge assays on the outcome of batch release testing in Europe. Eight laboratories including official medicines control laboratories (OMCLs) and manufacturers reported the results of their routine testing, using the BRP batch 3 in addition to their regular reference preparation. For each tested product, participants calculated the potency relative to their routine reference and relative to the BRP batch 3. No common sample panel was distributed to participants. In total, data on 40 batches of different marketed tetanus vaccines were reported. Overall, a good concordance was observed between the potencies calculated relative to the BRP batch 2 and relative to the BRP batch 3. On average, the potency estimates were 10 % lower when expressed relative to the BRP batch 3. Cases of discrepant decisions for batch release were very limited and affected mainly batches with specifications close to the pharmacopoeial requirements. The reasons for differences in estimated potencies are discussed. The study showed that the use of the BRP batch 3 with an assigned potency of 260 IU/ampoule does not result in substantial change in the potency of different marketed products. This confirmed that the mouse challenge potency value assigned to the BRP batch 3 is suitable.

Patient satisfaction with daycase laparoscopy

A prospective audit was performed on all patients preselected for daycase surgery over a 3-month period. The aim of the study was to evaluate patient acceptability and satisfaction with laparoscopy performed as a daycase procedure. Patients completed standard questionnaires before operation and at 4 weeks after surgery. Questions included satisfaction with daycase surgery, subjective pain experience, time taken to resume normal activities, adequacy of analgesia and necessity to call general practioners. Analysis of results revealed that 69% of patients were satisfied with day surgery laparoscopy. However there were highly significant differences (P less than 0.001) between resumption of normal activity, pain experienced and length of stay between patients satisfied and dissatisfied with daycase surgery. This study suggests that guidelines for daycase procedures may be overambitious as 31% of patients already pre-selected, were dissatisfied with daycase surgery.

Changing epidemiology of small-cell lung cancer in the United States over the last 30 years: analysis of the surveillance, epidemiologic, and end results database

PURPOSE

Small-cell lung cancer (SCLC) is a histologic subtype of lung cancer with a distinct biology and clinical course. It has been observed that the incidence of SCLC has been decreasing over the last several years.

METHODS

We used the Surveillance, Epidemiologic, and End Results (SEER) database to determine the incidence of SCLC over the last 30 years. In addition, we sought to determine sex- and stage-based differences in the incidence and survival of SCLC among a proportion of reported cases of lung cancer over the last 30 years (1973 to 2002). Joinpoint analyses were applied to test the trends in annual percentage change for statistical significance.

RESULTS

The proportion of SCLC (among all lung cancer histologic types) decreased from 17.26% in 1986 to 12.95% in 2002. Of all patients with SCLC, the proportion of women with SCLC increased from 28% in 1973% to 50% in 2002. A modest but statistically significant improvement in 2- and 5-year survival was noted among both limited-stage SCLC and extensive-stage SCLC cohorts during the study period.

CONCLUSION

Our analysis indicates that the incidence of SCLC is decreasing in the United States, and only modest improvements have been seen in survival over the last 30 years. Possible explanations for the decreasing incidence include the decrease in the percentage of smokers and the change to low-tar filter cigarettes. Despite trends toward modest improvement in survival, the outcome remains very poor.

Effectiveness of prophylactic hyperextension elbow braces on limiting active and passive elbow extension prephysiological and postphysiological loading

STUDY DESIGN

Experimental 3-factor design with repeated measures on all factors.

OBJECTIVES

The purpose of this study was to determine the effectiveness of 3 prophylactic hyperextension elbow braces on limiting active and passive elbow extension before and after exercise.

BACKGROUND

Prophylactic hyperextension elbow braces are used to protect the joint against excessive extension, but their effectiveness for this purpose has not been determined.

METHODS AND MATERIALS

Twenty Division I intercollegiate football players (mean +/- SD age, 20.2 +/- 1.3 years; mean +/- SD height, 184.4 +/- 9.9 cm, mean +/- SD mass, 102.9 +/- 22.0 kg) completed all phases of the study. The Breg Functional Elbow Brace, PRO 470 Kendall Elbow Brace, and DonJoy Elbow Guard were tested both actively and passively before and after an isokinetic exercise session on a Biodex Multi-Joint Testing and Exercise Dynamometer. For all tests, the braces were set at a 30 degrees flexion limit angle. The exercise session consisted of 1 set of reciprocal elbow extension and flexion at an angular velocity of 360 degrees/s, totaling 1627 J of work.

RESULTS

None of the braces limited elbow extension to the 30 degrees flexion limit. However, all of the braces were successful in preventing the elbow from reaching the vulnerable position of hyperextension. The Breg Functional Elbow Brace was the most effective for limiting elbow extension near its set angle, followed by the DonJoy Elbow Guard, and the PRO 470 Kendall Elbow Brace across all test conditions.

CONCLUSION

The braces' effectiveness to limit motion is enhanced when limits are set higher than the desired angle of the protected motion.

Effectiveness of Glenohumeral-Joint Stability Braces in Limiting Active and Passive Shoulder Range of Motion in Collegiate Football Players

OBJECTIVE: To determine the effectiveness of glenohumeral-joint stability braces in limiting active and passive shoulder abduction and external rotation in collegiate football players. DESIGN AND SETTING: A 2-factor, repeated-measures design was used. The independent variables were brace condition (Denison and Duke Wyre harness, Sawa shoulder brace) and force application (active, passive). The dependent variables were shoulder abduction (45 degrees braced limit) and external-rotation angular displacements. SUBJECTS: Fifteen National Collegiate Athletic Association Division I male college football players (age = 19.9 +/- 1.37 years, height = 183.2 +/- 7.85 cm, mass = 89.9 +/- 14.79 kg) participated in the study. MEASUREMENTS: We used the PEAK Motus motion analysis system to measure angular displacements. RESULTS: Neither brace maintained the arm position at the 45 degrees braced limit during active or passive shoulder abduction (motion ranged from 56.8 degrees to 73.0 degrees ). Although we did not use a priori external-rotation limits in this study, motion ranged from 71.6 degrees to 93.9 degrees with the braces. A repeated-measures multivariate analysis of variance indicated no significant interaction effect (P =.41), but main effects were significant for brace condition and force application (P <.001). Reported differences are statistically significant. For abduction, the Denison and Duke Wyre harness resulted in 12.3 degrees (21%) greater angular displacement than the Sawa shoulder brace, and passive abduction resulted in 3.9 degrees (6%) more angular displacement than active abduction. For external rotation, the Denison and Duke Wyre harness resulted in 6.7 degrees (9%) more angular displacement than the Sawa shoulder brace, and passive external rotation resulted in 15.6 degrees (21%) more angular displacement than active external rotation. CONCLUSIONS: Preset, braced abduction motion limits were not realized during active and passive physiologic loading of the glenohumeral joint. However, protection against the vulnerable position of 90 degrees of abduction and external rotation was attained at a preset braced limit of 45 degrees of abduction (the exception was the Denison and Duke Wyre harness during passive external rotation). The Sawa shoulder brace was most effective for this purpose.

Calibration of replacement international standard and European pharmacopoeia biological reference preparation for tetanus toxoid, adsorbed

Here we report the characterisation of a preparation of tetanus toxoid, adsorbed, and its calibration by 27 laboratories in 19 countries in a joint international collaborative study co-sponsored by World Health Organization (WHO) Expert Committee of Biological Standardization (ECBS) and the European Biological Standardisation Programme of European Directorate for the Quality of Medicines (EDQM), Council of Europe. Calibration was in terms of the Second International Standard (I.S.) for Tetanus Toxoid, Adsorbed, by the established WHO/European Pharmacopoeia (Ph Eur) challenge methods. The replacement standard preparation was found to have a unitage of 469 IU/ampoule on the basis of its calibration in guinea-pigs and 496 IU/ampoule on the basis of its calibration in mice. Assessment, both within the collaborative study and as part of candidate characterisation, indicated satisfactory stability of the candidate preparation. This study also provided some information on the effect of mouse strain on potency testing of tetanus vaccines. A limited assessment of the impact of the replacement standard on testing of current production batches of vaccines was also carried out by four manufacturers. This study did not directly address the serological approaches to potency testing. However, one laboratory offered data from mouse serology assay, which gave comparable estimates to in vivo mouse bioassay. Based on the results of this study and with the agreement of participants, the candidate standard was established as the Third International Standard for Tetanus Toxoid, Adsorbed (coded 98/552) by the WHO Expert Committee of Biological Standardization (ECBS) in November 2000. The same preparation was also established as the second Ph Eur Biological Reference Preparation (Ph Eur BRP, batch no. 2) by the Steering Committee of the Biological Standardisation Programme of the EDQM and approved by the European Pharmacopoeia Commission.

Neonatal novelty exposure modulates hippocampal volumetric asymmetry in the rat

Early life environmental manipulations have been shown to affect hippocampal-dependent learning, hippocampal volume and cerebral lateralization. In this study, we investigated the effects of neonatal stimulation on hippocampal volumetric asymmetry. Long-Evans hooded rats were exposed to a novel non-home environment 3 min daily for the first 3 weeks of life. Histological measures of the left and right hippocampus were made at 8 months of age. We found that neonatal novelty exposure resulted in a long-lasting change in hippocampal volumetric asymmetry. Specifically, this brief and transient early life stimulation increased the right hippocampal volumetric dominance at mid-adulthood.

The Epstein-Barr virus promoter initiating B-cell transformation is activated by RFX proteins and the B-cell-specific activator protein BSAP/Pax5

Epstein-Barr virus (EBV)-induced B-cell growth transformation, a central feature of the virus' strategy for colonizing the human B-cell system, requires full virus latent gene expression and is initiated by transcription from the viral promoter Wp. Interestingly, when EBV accesses other cell types, this growth-transforming program is not activated. The present work focuses on a region of Wp which in reporter assays confers B-cell-specific activity. Bandshift studies indicate that this region contains three factor binding sites, termed sites B, C, and D, in addition to a previously characterized CREB site. Here we show that site C binds members of the ubiquitously expressed RFX family of proteins, notably RFX1, RFX3, and the associated factor MIBP1, whereas sites B and D both bind the B-cell-specific activator protein BSAP/Pax5. In reporter assays with mutant Wp constructs, the loss of factor binding to any one of these sites severely impaired promoter activity in B cells, while the wild-type promoter could be activated in non-B cells by ectopic BSAP expression. We suggest that Wp regulation by BSAP helps to ensure the B-cell specificity of EBV's growth-transforming function.

An issue of conflicting rights: nursing student charged with drug trafficking

One semester before graduation, a nursing student was charged with a class A felony for drug trafficking. The nurse administrator recommended to university administration that the student be suspended from all clinical activity until charges were resolved. Initially, a summary action was issued by university administration to support this recommendation. A summary disciplinary action allows for temporary suspension of a student charged with misconduct when the student's presence threatens harm to the student or any other person. However, after legal review, the summary action was rescinded based on the complexity of conflicting interests and rights that required consideration and protection. The law provides some guidance but lacks the specificity to move an issue like this from equivocal to unequivocal in a short time frame. Consequently, the student was allowed to complete the program. Shortly after commencement, the graduate was convicted. In retrospect, it was found that ample case law exists allowing for a more aggressive defense of a summary action then had been taken. As pointed out in Krasnow v. Virginia Polytechnic Institute (1976), standards of student conduct established by a university may prohibit action that interferes with the mission or functions of the institution, and these standards may go beyond standards established by criminal law and may require greater ethical or moral behavior. Being prepared for situations such as the one presented here requires that schools have in place clearly defined policies and procedures that assure due process, allow for disciplinary action, reduce time and energy required to resolve conflicts, and assure consistent and fair outcomes.

Human papillomavirus infection and risk of progression of epithelial abnormalities of the cervix

The polymerase chain reaction has been used to determine the presence of human papillomavirus (HPV) 16 and HPV 18 DNA sequences in archival histological material removed from a cohort of untreated women with cervical epithelial abnormalities. The detection of HPV 16 or HPV 18 DNA sequences in the initial biopsy specimen was associated with a significantly increased risk of subsequent disease progression.

Cardiac Na+ pump current-voltage relationships at various transmembrane gradients of the pumped cations

Thermodynamic considerations predict changes of the Na+ pump current (Ip)-voltage (V) relationship of animal cells upon variations of the electrochemical gradients against which cations must be pumped. Experimental data in support of the predictions are sparse. Therefore, the effect on the Ip-V relationship of various electrochemical gradients for pumped Na+ and Cs+ was studied at constant deltaGATP (approximately -39kJ/mol in cardioballs from sheep Purkinje fibres. Control of the subsarcolemmal ionic concentrations during whole-cell recording was ensured by activation of Ip below its half maximal activity or by measuring the initial Ip following reactivation of the Na+/K+ pump. With gradients close to physiological conditions Ip was outward over the entire voltage range and the Ip-V relationship showed a maximum near zero potential. Steepening the ionic gradients diminished the Ip amplitude and outward pump current was no longer detectable between -65 mV and -110 mV. Flattened ionic gradients increased the Ip amplitude and shifted apparently the reversal potential Erev to more negative values. These changes are in line with theoretical considerations. The measured Ip-V relationships were fitted by curves computed on the basis of a simplified Post-Albers scheme of Na+/Cs+ pumping. The increased Ip amplitude at flat ionic gradients was due to a decrease of [Cs+]o for half maximal Ip activation. The maximal Ip amplitude remained unaffected

Non-Hodgkin's lymphoma, coeliac disease, and Epstein-Barr virus: a study of 13 cases of enteropathy-associated T- and B-cell lymphoma

A group of 166 patients with coeliac disease was followed for a period of up to 25 years. During this time, 17 patients developed intestinal tumours that were diagnosed as lymphoma, of which 15 cases were available for review. Eleven of the lymphomas were of T-cell type (enteropathy-associated T-cell lymphoma, EATL) and two were of B-cell type. Two cases were reclassified as undifferentiated carcinoma. The interval between the diagnosis of enteropathy and the onset of lymphoma varied from less than 2 months in four patients to more than 5 years in seven. Seven of the T-cell and both B-cell lymphomas were investigated for the presence of Epstein-Barr virus (EBV) by in situ hybridization (ISH) using probes against Epstein-Barr virus-encoded RNAs (EBERs) and by immunohistochemistry with EBV-specific monoclonal antibodies. All EATL cases were negative, suggesting that EBV is not an important factor in these cases. In one of the B-cell cases, EBV was detectable by ISH and immunohistochemistry in most tumour cells in the mesenteric lymph nodes, but not in any of the tumour cells in the primary ileal tumour, indicating that in this case EBV infection was a late event in the neoplastic process. These results show that lymphoma may develop any time after the onset of coeliac disease and that in our cases of EATL, EBV was not an important factor. In some cases of EBV-related neoplasia, virus infection may be a late event.

Effects of variations in flow on aortic valve area in aortic stenosis based on in vivo planimetry of aortic valve area by multiplane transesophageal echocardiography

This study provides evidence that acute changes in stroke volume and cardiac output do not result in significant alterations in the anatomic AVA measured with multiplane TEE in patients with AS of moderate or severe degree. Thus, TEE could be useful in the assessment of severity of AS in both low- and high-output states.

Latent Epstein-Barr virus infection in cottontop tamarins. A possible model for Epstein-Barr virus infection in humans

The association of Epstein-Barr virus (EBV) with a growing number of human malignancies underlines the importance of efforts aimed at preventing the infection with this potential carcinogen and of establishing animal models for human virus-associated tumors. Cottontop tamarins have been used in EBV vaccine studies because virus infection regularly induces lymphomas similar to those seen in human immunocompromised individuals. In recent years, several vaccines based on the gp340/220 envelope protein of EBV have been developed and shown to prevent the development of EBV-associated lymphomas in this model. Using in situ hybridization and immunohistology, we have characterized EBV infection in one nonimmunized and three immunized animals after challenge with a standard tumorigenic dose of EBV. In the nonimmunized animal, EBV-infected lymphoid cells were detected in numerous tissues showing no obvious lymphoma infiltration. Surprisingly, variable numbers of virus-carrying cells were also found in all three immunized animals that were protected against the development of virus-associated lymphoma. This observation demonstrates that vaccination does not induce sterilizing immunity against EBV infection in this model. Double labeling suggested a B cell phenotype of the majority of these cells. EBV infection of nonlymphoid cells was not observed. Analysis of viral gene expression in immunized animals suggested a restricted form of virus latency different from that seen in EBV-driven lymphomas in nonimmunized cottontop tamarins. These results raise the possibility that immunized cottontop tamarins protected against the development of EBV-driven lymphoma or animals exposed to a sublymphomagenic dose of virus may serve as a model for EBV infection in humans.

Lack of peptide YY immunoreactivity in adenomatous colonic polyps: evidence in favor of an adenoma-carcinoma sequence

The aim of endoscopic polypectomy is to prevent colorectal cancer, as it is assumed that most, if not all, large bowel cancers are derived from adenomatous polyps. While it is now recognized that colonic endocrine cells, like other mucosal epithelial cells, have an endodermal origin, they are relatively sparse components of large bowel tumors. Peptide YY (PYY) is the most abundant endocrine regulatory peptide localized to the distal bowel. Endocrine cells, like the other cells of the mucosal epithelia, are derived from a common stem cell in the base of the crypts. The presence of endocrine peptides may thus be viewed as a marker for cellular differentiation in the gut. PYY was therefore measured in colonic carcinomas and adenomatous polyps, as its absence would be evidence in favor of genetic alterations in epithelial stem cell maturation. PYY concentrations in extracts of surgically removed colonic carcinomas (n = 22) from all regions were very low compared with those of adjacent normal bowel. Similarly, PYY concentrations in extracts of polyps (n = 39) obtained during endoscopic polypectomy were also very low when compared with those of adjacent normal mucosa. These varied between 1 and 11% of the normal epithelial content, depending upon the region. Low PYY levels appeared to reflect the malignant potential of these lesions: highest in tubular polyps, lower in villous polyps, and lowest in carcinomas. The very low concentrations of PYY in adenomatous polyps, like those of colonic cancer, are consistent with epithelial dysplasia and the incomplete formation of mucosal endocrine cells. These findings support the hypothesis of an adenoma to carcinoma sequence in colonic cancer.