bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elbow Medial Ulnar Collateral Ligament Insufficiency Alters Posteromedial Olecranon Contact
Authors: Ahmad Christopher S. , Park Maxwell C. , ElAttrache Neal S. 
Published: August 2004

Background The effect of elbow medial ulnar collateral ligament injury on posteromedial compartment contact is unknown. Hypothesis Medial ulnar collateral ligament injury causes altered contact area and pressure in the posteromedial compartment of the elbow. Study Design Controlled laboratory study. Methods Seven elbow cadaveric specimens were tested in an apparatus that positioned the elbow at 30° and 90° of flexion. Partial and full tears were simulated by releasing the medial ulnar collateral ligament. Pressure-sensitive film was placed in the posteromedial compartment for each condition. Valgus torques of 1.25 and 2.0 N.m were applied for each ligament condition, and kinematic data were obtained at each flexion angle using a 3-dimensional digitizer. Results Both ligament condition and valgus load had significant effects on contact area and pressure (P < .05). For a given load and flexion angle, the contact area decreased and the pressure increased with increasing medial ulnar collateral ligament insufficiency. Within these trends, statistical significance was found at 30° of elbow flexion for both area and pressure (P < .05); at 90° of elbow flexion, increasing medial ulnar collateral ligament insufficiency did not significantly affect contact area or pressure (P > .05). Discussion Medial ulnar collateral ligament insufficiency alters contact area and pressure between the posteromedial trochlea and olecranon and helps explain the development of posteromedial osteophytes.
Parecoxib Impairs Early Tendon Repair but Improves Later Remodeling
Authors: Virchenko Olena , Skoglund Björn , Aspenberg Per 
Published: August 2004

Background Cyclooxygenase-2 inhibitors inhibit bone repair. Hypothesis Cyclooxygenase inhibitors might also have a negative effect on early tendon repair, although a positive effect on late tendon repair previously has been shown. Study Design Controlled laboratory study. Methods Achilles tendon transection was performed on 80 rats. Sixty rats were given daily intramuscular injections of either parecoxib (6.4 mg/kg body weight) or saline for the first 5 days after surgery and sacrificed either at 8 or 14 days. The remaining 20 rats were given intramuscular parecoxib or saline injections from day 6 until sacrifice at 14 days. Results At 8 days, early parecoxib treatment caused a 27% decrease in force at failure (P = .007), a 25% decrease in maximum stress (P = .01), and a 31% decrease in energy uptake (P = .05). Stiffness and transverse area were not significantly affected. At 14 days, early parecoxib treatment caused a decrease in stiffness (P = .004). In contrast to early treatment, late parecoxib treatment caused a 16% decrease in cross-sectional area (P = .03) and a 29% increase in maximum stress (P = .04). Conclusions During early tendon repair, a cyclooxygenase-2 inhibitor had a detrimental effect. During remodelling, however, inflammation appears to have a negative influence, and cyclooxygenase-2 inhibitors might be of value. Clinical Relevance The results suggest that cyclooxygenase-2 inhibitors should be used with care in the early period after tendon injury.
Cannulated Screw Fixation of Jones Fractures
Authors: Reese Keri , Litsky Alan , Kaeding Christopher , Pedroza Angela , Shah Nilesh 
Published: August 2004

Background Traditional nonsurgical treatment of Jones fractures has high rates of delayed union, nonunion, and refracture. Internal fixation has become the treatment of choice in athletes and active patients. Purpose The purpose of this study was (1) to review the short- and long-term clinical results of cannulated screw fixation of Jones fractures and (2) to perform a biomechanical evaluation of fatigue failure characteristics of several types of screws used in the fixation of Jones fractures. Study Design Retrospective case series and in vitro biomechanical study. Methods Ten male and 5 female patients with Jones fractures fixed with cannulated screws ranging from 4 mm to 6.5 mm in diameter were evaluated by chart review, review of radiographs, and telephone interview. Mean follow-up from surgery to phone survey was 34 months. Screws ranging in size from 2.7 mm to 7.3 mm, both cannulated and noncannulated, stainless steel and titanium, were tested in the laboratory by cyclic loading to 250 N up to a maximum of 200 000 cycles. Results Mean time to healing as shown on radiographs and by full activity after surgery were 7.3 and 7.9 weeks, respectively. All patients were able to return to their previous levels of activity. Screw fatigue data showed that the number of cycles to failure increased with increasing screw diameter. For 4-mm screws, mean number of cycles to failure was 4308 for cannulated titanium screws, 22 012 for cannulated stainless steel screws, and 44 523 for noncannulated stainless steel screws. Conclusions In our patients, cannulated screw fixation of Jones fractures was a procedure that was reliable, had low morbidity, and afforded athletes a quick return to activity. Clinical Relevance The laboratory study suggests that the largest screw possible should be used for surgical fixation of these fractures and that screws less than 4 mm in diameter should be used with caution.
Bone Anchors or Interference Screws?
Authors: Jeys Lee , Korrosis Sotiris , Stewart Todd , Harris Nicholas J. 
Published: August 2004

Background Autograft stabilization uses free semitendinosus tendon grafts to anatomically reconstruct the anterior talofibular ligament. Study aims were to evaluate the biomechanical properties of Mitek GII anchors compared with the Arthrex Bio-Tenodesis Screw for free tendon reconstruction of the anterior talofibular ligament. Null Hypothesis There are no differences in load to failure and percentage specimen elongation at failure between the 2 methods. Study Design Controlled laboratory study using porcine models. Methods Sixty porcine tendon constructs were failure tested. Re-creating the pull of the anterior talofibular ligament, loads were applied at 70° to the bones. Thirty-six tendons were fixed to porcine tali and tested using a single pull to failure; 10 were secured with anchors and No. 2 Ethibond, 10 with anchors and Fiber Wire, 10 with screws and Fiberwire, and 6 with partially gripped screws. Cyclic preloading was conducted on 6 tendons fixed by anchors and on 6 tendons fixed by screws before failure testing. Two groups of 6 components fixed to the fibula were also tested. Results The talus single-pull anchor group produced a mean load of 114 N and elongation of 37% at failure. The talus single-pull screw group produced a mean load of 227 N and elongation of 22% at failure (P < .05). Cyclic preloading at 65% failure load before failure testing produced increases in load and decreases in elongation at failure. Partially gripped screws produced a load of 133 N and elongation of 30% at failure. The fibula model produced significant increases in load to failure for both. The human anterior talofibular ligament has loads of 139 N at failure with instability occurring at 20% elongation. Conclusions Interference screw fixation produced significantly greater failure strength and less elongation at failure than bone anchors. Clinical Relevance The improved biomechanics of interference screws suggests that these may be more suited to in vivo reconstruction of the anterior talofibular ligament than are bone anchors.
Prospective Evaluation of the Effect of Rotator Cuff Integrity on the Outcome of Open Rotator Cuff Repairs
Authors: Klepps Steven , Bishop Julie , Lin Jason , Cahlon Oren , Strauss Alyssa , Hayes Patrick , Flatow Evan L. 
Published: August 2004

Background Open rotator cuff repairs have led to excellent clinical results; however, several studies have linked postoperative structural integrity to patient outcomes. The purpose of this study is to prospectively assess postoperative cuff integrity after open rotator cuff repair and assess its relationship to clinical outcome. Hypothesis Preoperative rotator cuff tear size and postoperative rotator cuff integrity are important factors in overall clinical outcomes. Study Design Prospective nonrandomized clinical outcomes study. Methods Forty-seven consecutive patients undergoing repair of full-thickness rotator cuff tears by a single surgeon were enrolled in this prospective study. A standardized evaluation was performed preoperatively and postoperatively at annual intervals. All patients underwent postoperative magnetic resonance imaging at least 1 year after surgery. Statistical evaluation was performed using paired and unpaired 2-tailed t tests for comparison. Results Thirty-two patients were available for evaluation. Overall, the patients experienced a significant (P < .05) improvement in their American Shoulder and Elbow Surgeons survey (40-85) and Constant (53-80) scores. The overall retear rate was 31%. Although patients with large tears preoperatively and retears postoperatively had lower overall outcomes scores, this was not significant. Conclusion These data support open rotator cuff repair as an effective technique that restores excellent shoulder function. The authors did not find postoperative cuff integrity to have a significant effect on outcomes when compared with those with an intact cuff. In fact, those with a retear still had a significant improvement in all clinical areas assessed, including strength.
The Effect of Posterior Cruciate Ligament Injury and Reconstruction on Meniscal Strain
Authors: Pearsall Albert W. , Hollis J. Marcus 
Published: August 2004

Background The relationship between posterior cruciate ligament insufficiency and meniscal injury is unclear. Hypothesis Posterior cruciate ligament insufficiency results in increased medial and lateral meniscal strain. Study Design Descriptive anatomic study. Methods Eight cadaveric specimens were evaluated with a 6-axis load cell and differential variable reluctance transducer strain gauges placed in both menisci. Data were recorded in the posterior cruciate ligament–intact state after posterior cruciate ligament transection and after posterior cruciate ligament reconstruction. Results The effect of posterior cruciate ligament state on meniscal strain was more pronounced at higher flexion angles. At 60° and 90° of flexion, there was a significant effect of posterior cruciate ligament sectioning and reconstruction on meniscal strain (P < .026). Average meniscal strain for both medial and lateral menisci increased between the intact and the posterior cruciate ligament–cut states. Posterior cruciate ligament reconstruction decreased strain values to that of the intact knee. Conclusions Meniscal strain increases with complete posterior cruciate ligament injury and is returned to posterior cruciate ligament–intact levels after posterior cruciate ligament reconstruction. Clinical Relevance Posterior cruciate ligament reconstruction may play an important role in reducing meniscal strain and sub-sequent degeneration within the posterior cruciate ligament–injured knee.
Incidence, Causes, and Severity of High School Football Injuries on FieldTurf versus Natural Grass
Authors: Meyers Michael C. , Barnhill Bill S. 
Published: August 2004

Background Numerous injuries have been attributed to playing on artificial turf. Recently, FieldTurf was developed to duplicate the playing characteristics of natural grass. No long-term study has been conducted comparing game-related, high school football injuries between the 2 playing surfaces. Hypothesis High school athletes would not experience any difference in the incidence, causes, and severity of game-related injuries between FieldTurf and natural grass. Study Design Prospective cohort study. Methods A total of 8 high schools were evaluated over 5 competitive seasons for injury incidence, injury category, time of injury, injury time loss, player position, injury mechanism, primary type of injury, grade and anatomical location of injury, type of tissue injured, head and knee trauma, and environmental factors. Results Findings per 10 team games indicated total injury incidence rates of 15.2 (95% confidence interval, 13.7-16.4) versus 13.9 (95% confidence interval, 11.9-15.6). Minor injury incidence rates of 12.1 (95% confidence interval, 10.5-13.6) versus 10.7 (95% confidence interval, 8.7-12.7), substantial injury incidence rates of 1.9 (95% confidence interval, 1.4-2.6) versus 1.3 (95% confidence interval, 0.8-2.1), and severe injury incidence rates of 1.1 (95% confidence interval, 0.7-1.7) versus 1.9 (95% confidence interval 1.2-2.8) were documented on FieldTurf versus natural grass, respectively. Multivariate analyses indicated significant playing surface effects by injury time loss, injury mechanism, anatomical location of injury, and type of tissue injured. Higher incidences of 0-day time loss injuries, noncontact injuries, surface/epidermal injuries, muscle-related trauma, and injuries during higher temperatures were reported on FieldTurf. Higher incidences of 1- to 2-day time loss injuries, 22+ days time loss injuries, head and neural trauma, and ligament injuries were reported on natural grass. Conclusions Although similarities existed between FieldTurf and natural grass over a 5-year period of competitive play, both surfaces also exhibited unique injury patterns that warrant further investigation.
A New Mechanical Testing Device for Measuring Anteroposterior Knee Laxity
Authors: Schuster Andreas J. , Mcnicholas Mike J. , Wachtl Stefan W. , McGurty Douglas W. , Jakob Roland P. 
Published: August 2004

Background The authors assessed a new instrument, the Rolimeter, for the measurement of anteroposterior translation in the knee; it was compared to the KT-1000 arthrometer. Purpose To determine if the Rolimeter offers a valid method for the measurement of anteroposterior translation that is as reproducible and reliable as the KT-1000 arthrometer. Methods Two of 3 observers examined 16 normal subjects (32 knees) and 36 patients (72 knees) with ligament ruptures twice, using both the Rolimeter and the KT-1000 arthrometers, 30 minutes apart. Total anteroposterior translation (manual maximal Lachman test) was recorded at 20° and 80° of knee flexion. Results On average, the Rolimeter measured approximately 1 mm less anteroposterior displacement than the KT-1000 arthrometer at manual maximum stress. Rolimeter measurements were more consistent than the KT-1000 measurements as measured by our observers. Specificity and sensitivity were equivalent between the Rolimeter and the KT-1000 arthrometer. Conclusions The Rolimeter is as reproducible and reliable as the KT-1000 arthrometer. It offers a valid method for the measurement of anteroposterior translation in the knee. Higher accuracy was obtained at 20° of flexion for the KT-1000 arthrometer and at 80° of flexion for the Rolimeter.
The Hotdog fold: wrapping up a superfamily of thioesterases and dehydratases
Authors: Dillon Shane C , Bateman Alex 
Published: August 2004

Abstract
Background
The Hotdog fold was initially identified in the structure of Escherichia coli FabA and subsequently in 4-hydroxybenzoyl-CoA thioesterase from Pseudomonas sp. strain CBS. Since that time structural determinations have shown a number of other apparently unrelated proteins also share the Hotdog fold.

Results
Using sequence analysis we unify a large superfamily of HotDog domains. Membership includes numerous prokaryotic, archaeal and eukaryotic proteins involved in several related, but distinct, catalytic activities, from metabolic roles such as thioester hydrolysis in fatty acid metabolism, to degradation of phenylacetic acid and the environmental pollutant 4-chlorobenzoate. The superfamily also includes FapR, a non-catalytic bacterial homologue that is involved in transcriptional regulation of fatty acid biosynthesis.
We have defined 17 subfamilies, with some characterisation. Operon analysis has revealed numerous HotDog domain-containing proteins to be fusion proteins, where two genes, once separate but adjacent open-reading frames, have been fused into one open-reading frame to give a protein with two functional domains. Finally we have generated a Hidden Markov Model library from our analysis, which can be used as a tool for predicting the occurrence of HotDog domains in any protein sequence.

Conclusions
The HotDog domain is both an ancient and ubiquitous motif, with members found in the three branches of life.
Slowly developing depression of N-methyl-D-aspartate receptor mediated responses in young rat hippocampi
Authors: Dozmorov Mikhail , Li Rui , Xu Hui-Ping , Jilderos Barbro , Wigström Holger 
Published: August 2004

Abstract
Background
Activation of N-methyl-D-aspartate (NMDA) type glutamate receptors is essential in triggering various forms of synaptic plasticity. A critical issue is to what extent such plasticity involves persistent changes of glutamate receptor subtypes and many prior studies have suggested a main role for alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors in mediating the effect. Our previous work in hippocampal slices revealed that, under pharmacological unblocking of NMDA receptors, both AMPA and NMDA receptor mediated responses undergo a slowly developing depression. In the present study we have further adressed this phenomenon, focusing on the contribution via NMDA receptors. Pharmacologically isolated NMDA receptor mediated excitatory postsynaptic potentials (EPSPs) were recorded for two independent synaptic pathways in CA1 area using perfusion with low Mg2+ (0.1 mM) to unblock NMDA receptors.

Results
Following unblocking of NMDA receptors, there was a gradual decline of NMDA receptor mediated EPSPs for 2–3 hours towards a stable level of ca. 60–70 % of the maximal size. If such an experimental session was repeated twice in the same pathway with a period of NMDA receptor blockade in between, the depression attained in the first session was still evident in the second one and no further decay occurred. The persistency of the depression was also validated by comparison between pathways. It was found that the responses of a control pathway, unstimulated in the first session of receptor unblocking, behaved as novel responses when tested in association with the depressed pathway under the second session. In similar experiments, but with AP5 present during the first session, there was no subsequent difference between NMDA EPSPs.

Conclusions
Our findings show that merely evoking NMDA receptor mediated responses results in a depression which is input specific, induced via NMDA receptor activation, and is maintained for several hours through periods of receptor blockade. The similarity to key features of long-term depression and long-term potentiation suggests a possible relation to these phenomena. Additionally, a short term potentiation and decay (<5 min) were observed during sudden start of NMDA receptor activation supporting the idea that NMDA receptor mediated responses are highly plastic.
Synergic effect of chronic hepatitis C infection and beta thalassemia major with marked hepatic iron overload on liver fibrosis: a retrospective cross-sectional study
Authors: Ardalan Farid Azmoudeh , Osquei Mohammad RF , Toosi Mohsen N , Irvanloo Guiti 
Published: August 2004

Abstract
Background
Increased hepatic iron is assumed to potentiate progression towards liver fibrosis in chronic hepatitis C virus (HCV) infection. In this study we have evaluated the potentiating effect of marked hepatic iron overload and chronic HCV infection on hepatic fibrosis in thalassemic patients.

Methods
Liver biopsies of one group of patients with beta thalassemia major and chronic HCV infection (group 1) was compared with two groups of patients (groups 2&3) with either chronic HCV infection or thalassemia major, respectively (20 patients in each group). Necroinflammation, fibrosis, and iron overload were graded and compared.

Results
Stage of fibrosis in group 1 patients was significantly higher than the other two groups (p < 0.05). Necroinflammatory grade was significantly lower, but iron score was significantly higher in thalassemic patients (group 3) in comparison to groups 1 and 2 (p < 0.05).

Conclusion
Our results indicate that marked liver iron overload and HCV infection in thalassemic patients have potentiating effect on hepatic fibrogenesis.
Drop-out and mood improvement: a randomised controlled trial with light exposure and physical exercise [ISRCTN36478292]
Authors: Leppämäki Sami , Haukka Jari , Lönnqvist Jouko , Partonen Timo 
Published: August 2004

Abstract
Background
Combining bright light exposure and physical exercise may be an effective way of relieving depressive symptoms. However, relatively little is known about individual factors predicting either a good response or treatment failure. We explored background variables possibly explaining the individual variation in treatment response or failure in a randomised trial.

Methods
Participants were volunteers of working-age, free from prior mental disorders and recruited via occupational health centres. The intervention was a randomised 8-week trial with three groups: aerobics in bright light, aerobics in normal room lighting, and relaxation/stretching in bright light. Good response was defined as a 50% decrease in the symptom score on either the Hamilton Depression Rating Scale (HDRS) or 8-item scale of atypical symptoms. Background variables for the analysis included sex, age, body-mass index, general health habits, seasonal pattern, and sleep disturbances.

Results
Complete data were received from 98 subjects (11 men, 87 women). Of them, 42 (5 men, 37 women) were classified as responders on the HDRS. Overall, light had a significant effect on the number of responders, as assessed with the HDRS (X2 = .02). The number needed to treat (NNT) for light was 3.8.

Conclusions
We investigated the effect of bright light and exercise on depressive symptoms. Problems with sleep, especially initial insomnia, may predict a good response to treatment using combined light and exercise. Bright light exposure and physical exercise, even in combination, seem to be well tolerated and effective on depressive symptoms.