Evaluation of two enzyme immunoassays for detection of human rotaviruses in fecal specimens.

The two assays evaluated in this study (the Ridascreen rotavirus and the Pathfinder rotavirus) exhibited comparable sensitivities (100%) but highly divergent positive predictive values (93.74 and 57.7%, respectively) when compared on 393 specimens. This difference should be considered when using these tests on collectives with an unknown or low prevalence.

Total strain fields of the antero-inferior shoulder capsule under subluxation: a stereoradiogrammetric study.

The antero-inferior capsule (AIC) is the primary restraint to antero-inferior glenohumeral dislocation. This study utilizes a biomechanical model to determine the total strain field of the AIC in a subluxed shoulder. Strains were calculated from two capsule states: a nominal strain state set by inflation and a strained state set by subluxation. Marker coordinates on the AIC were reconstructed from stereoradiographs and strain fields calculated. Peak strain on the glenoid side of the AIC was significantly greater than the humeral side and strain fields were highly variable. This study reports an accurate method for measuring planar strains in a three-dimensional membrane.

The relationship between Parson's tubercle and the insertion of the anterior horn of the medial meniscus.

PURPOSE: The purpose of this investigation was to correlate the anatomic characteristics of the third intercondylar tubercle of Parsons (TITP) with the insertional variations of the anterior horn of the medial meniscus using precise measurements in an anatomic cadaver study. Our hypothesis was that the height of the TITP would correlate with the degree of inferior insertion of the medial meniscus. TYPE OF STUDY: A cadaver study using a convenience sample. METHODS: Twenty unpaired proximal tibia specimens without advanced arthritis were analyzed with a coordinate measuring machine using a 0.479-mm diameter probe. A reference plane was created using 3 reproducible points on the tibial surface. Measurements from the TITP included another reference plane through its base, which was used to calculate its absolute height. The locations of the anterior- and inferior-most insertional points of the anterior horn of the medial meniscus were also determined. Correlations between the height of the TITP and age were also made. RESULTS: The overall height of the TITP was found to correlate with the degree of inferior insertion of the anterior horn of the medial meniscus (r =.52, P =.019). No correlation was found with the anterior placement of the meniscus (r =.12, P =.629) or with the age of the specimen (r =.14, P =.592). CONCLUSIONS: This absolute height of the TITP correlates with the inferior location of the insertion of the anterior horn of the medial meniscus. This association suggests a developmental relationship between 2 anatomic structures within the knee.

Replication-competent herpes simplex virus type 1 mutant expressing an autofluorescent glycoprotein H fusion protein.

The heterocomplex of glycoproteins H (gH) and L (gL) of herpes simplex virus type 1 (HSV-1) is essential for viral infectivity and is involved in viral penetration, cell-to-cell spread, and syncytium formation. We constructed an HSV-1 mutant expressing a gH-EGFP (enhanced green fluorescent protein) fusion protein under the control of the gH true late promoter. The EGFP coding sequence was cloned after the gH signal peptide into the HSV-1 genome. Superinfection of transfected, gH-nontranscomplementing cells with gH-negative HSV-1 resulted in a replication-competent recombinant virus. Cells infected with the recombinant virus exhibited strong and stable EGFP-specific fluorescence late in infection, and autofluorescence was detected in purified virions. The recombinant genotype of the mutant was confirmed by PCR. The 140-kD gH-EGFP fusion protein showed an N-linked glycosylation pattern similar to gH-1, was recognized by the conformation-dependent gH-specific monoclonal antibodies 52S and LP11 and formed a heterocomplex with gL which was transported to the cell surface and integrated into the viral envelope. Infectivity of the gH-EGFP mutant was neutralized by antibodies 52S and LP11. To our knowledge, this is the first replication-competent HSV-1 mutant expressing an autofluorescent essential glycoprotein which will be a versatile tool for studies of penetration, late gene expression, transport and tissue spread.

Detection of human serum antibodies against type-specifically reactive peptides from the N-terminus of glycoprotein B of herpes simplex virus type 1 and type 2 by surface plasmon resonance.

A single-step surface plasmon resonance protocol for the detection of antibodies against herpes simplex virus type 1 and type 2 (HSV-1, HSV-2) in human sera was established using the BIAcore system. Two peptides from corresponding segments of the N-terminus of HSV-1 and HSV-2 glycoprotein B (gB), i.e. peptide gB-1 (60-73) (GAAPTGDPKPKKNK) and peptide gB-2 (55-68) (SPATTKARKRKTKK), were identified as immunogenic. Employing both peptides as diagnostic antigens in the surface plasmon resonance assay, a sensitivity for the detection of HSV-1 and HSV-2 type-specific antibodies of 83 and 86%, respectively, was achieved as compared with immunoblotting as a reference method. Peptide gB-1 (60-73) allowed the discrimination between HSV-1 and HSV-2 type-specific antibodies with a specificity of 67%, whereas peptide gB-2 (55-68) reacted in a strictly HSV-2 type-specific manner. It is concluded that peptides from the N-terminus of gB-1 and gB-2 are recognized predominantly by human sera in an HSV-specific manner. Peptide gB-2 (55-68) can be employed successfully for the determination of type-specific antibodies against HSV-2.

Sonography of the glenoid labrum: a cadaveric study with arthroscopic correlation.

OBJECTIVE: We assessed the usefulness of sonography in evaluating the glenoid labrum in cadaveric specimens using arthroscopy as a standard of reference. MATERIALS AND METHODS: Eighty labral quadrants in 20 cadaveric shoulders were examined by two musculoskeletal radiologists using 5- to 7-MHz linear and curvilinear transducers. Agreement was reached by consensus. After sonography, arthroscopy was performed by an experienced orthopedic surgeon. Each labral quadrant was classified at the time of sonography and arthroscopy as normal, degenerated, or torn. RESULTS: Concordance between sonography and arthroscopy was 86% (69/80 quadrants). In differentiating abnormal labrum (tear or degeneration) from normal labrum using sonography, sensitivity was 63%, specificity was 98%, positive predictive value was 94%, negative predictive value was 86%, and accuracy was 88%. In differentiating labral tears from other labral conditions (degeneration or normality), sensitivity was 67%, specificity was 99%, positive predictive value was 67%, negative predictive value was 99%, and accuracy was 98%. CONCLUSION: Sonography has a promising role in the evaluation of the glenoid labrum, particularly in excluding labral tears when the labra appear normal on sonography. Further studies are required using normal and symptomatic patients to determine the usefulness of sonography in the diagnosis of labral abnormalities.

Ligamentous restraints to external rotation of the humerus in the late-cocking phase of throwing. A cadaveric biomechanical investigation.

The late-cocking phase of throwing is characterized by extreme external rotation of the abducted arm; repeated stress in this position is a potential source of glenohumeral joint laxity. To determine the ligamentous restraints for external rotation in this position, 20 cadaver shoulders (mean age, 65 +/- 16 years) were dissected, leaving the rotator cuff tendons, coracoacromial ligament, glenohumeral capsule and ligaments, and coracohumeral ligament intact. The combined superior and middle glenohumeral ligaments, anterior band of the inferior glenohumeral ligament, and the entire inferior glenohumeral ligament were marked with sutures during arthroscopy. Specimens were mounted in a testing apparatus to simulate the late-cocking position. Forces of 22 N were applied to each of the rotator cuff tendons. An external rotation torque (0.06 N x m/sec to a peak of 3.4 N x m) was applied to the humerus of each specimen with the capsule intact and again after a single randomly chosen ligament was cut (N = 5 in each group). Cutting the entire inferior glenohumeral ligament resulted in the greatest increase in external rotation (10.2 degrees +/- 4.9 degrees). This was not significantly different from sectioning the coracohumeral ligament (8.6 degrees +/- 7.3 degrees). The anterior band of the inferior glenohumeral ligament (2.7 degrees +/- 1.5 degrees) and the superior and middle glenohumeral ligaments (0.7 degrees +/- 0.3 degrees) were significantly less important in limiting external rotation.

The effect of knee and ankle position on displacement of Achilles tendon ruptures in a cadaveric model. Implications for nonoperative management.

Using a cadaveric model, we evaluated the effect of knee and ankle position on the displacement of the severed ends of an Achilles tendon transected at three different points. In six cadaveric legs the Achilles tendon was severed transversely, then marked with radiopaque wire suture. The distance between the wire markers was measured on radiographs taken in different positions of ankle and knee flexion. Ankle plantar flexion had a statistically significant effect on decreasing the gap between the severed ends of the Achilles tendon. This effect was clinically significant as, on average, the tendon edges were separated more than 20 mm when the ankle was in the neutral position and were apposed when the ankle was in 60 degrees of plantar flexion. With the ankle fixed in 60 degrees of plantar flexion, knee position had no significant effect on the displacement of the severed ends of the Achilles tendon. Overall, the effect of knee flexion was neither statistically significant nor clinically significant, as the increase in displacement of the severed ends of the Achilles tendon was only 3 mm from 0 degrees to 120 degrees of knee flexion. These results suggest that the nonoperative treatment of Achilles tendon ruptures requires immobilization in maximal ankle plantar flexion, and that immobilization of the knee may not be necessary to achieve tendon-edge apposition.

Prospective analysis of ice hockey injuries at the Junior A level over the course of one season.

OBJECTIVE: This study was conducted to identify the circumstances, timing, frequency, and types of injuries for a Junior A hockey team in an attempt to develop injury prevention strategies. DESIGN: This study was a prospective review of injuries sustained by a hockey team during one season. SETTING: Players were evaluated in a private practice clinical setting and during practices and games. PARTICIPANTS: Twenty-two hockey players (16-20 years old) were evaluated. An injury was defined as any event requiring the attention of a physician or trainer. The players sustained 83 injuries throughout the course of the season. Seventy-four were considered independent events. MAIN OUTCOME MEASURES: The effects of the following variables on injury rates were analyzed: position, game situation versus practice, and timing of injury during the game. RESULTS: Players were 20 times more likely to injure themselves during a game than practice. Although forwards sustained the highest total percentage of injuries, defensemen had the highest incidence of injury in games. More injuries occurred in the later periods and in the later minutes of each period. Injury incidence decreased for the second half of the season compared with the first half. CONCLUSION: Our data suggest goaltenders are at the lowest risk of sustaining an injury, but forwards appear to be at a higher risk in practice situations and defensemen in games. Game situations place players at a much greater risk of injury than practice sessions, particularly in the later portions of each period and toward the end of the game. Given the propensity for injury in the early season and later in the game, endurance training before and during the season may be important in injury prevention.

Symptomatic scapulothoracic crepitus and bursitis.

Scapulothoracic crepitus and scapulothoracic bursitis are related painful disorders of the scapulothoracic articulation. Scapulothoracic crepitus is the production of a grinding or snapping noise with scapulothoracic motion, which may be accompanied by pain. Scapulothoracic bursitis manifests as pain and swelling of the bursae of the scapulothoracic articulation. Scapulothoracic bursitis is always seen in patients with symptomatic scapulothoracic crepitus, but may exist as an isolated entity. Symptomatic scapulothoracic crepitus may be due to pathologic changes in the bone or soft tissue between the scapula and the chest wall or may be due to changes in congruence of the scapulothoracic articulation, as seen in scoliosis and thoracic kyphosis. Treatment of patients with symptomatic scapulothoracic crepitus begins with nonoperative methods, including postural and scapular strengthening exercises and the application of local modalities. When soft-tissue lesions are the cause of scapulothoracic crepitus, conservative treatment is highly effective. When symptomatic scapulothoracic crepitus is due to osseous lesions, or when conservative treatment has failed, surgical options are available. Partial scapulectomies have produced satisfactory outcomes in selected patients. Recently, open and arthroscopic scapulothoracic bursectomies have been performed with some success and are being used more frequently.

The mechanism of creation of superior labrum, anterior, and posterior lesions in a dynamic biomechanical model of the shoulder: the role of inferior subluxation.

Lesions of the superior glenoid labrum are a source of shoulder disease. However, the mechanisms of injury to this region are unknown, and controversy exists regarding the role of shoulder instability in creation of this lesion. With a cadaver model that simulates physiologic rotator cuff forces and produces traction on the biceps tendon, the creation of type II superior labrum, anterior, and posterior (SLAP) lesions and the role of glenohumeral subluxation were investigated: Left and right shoulders from each of 8 paired cadavers (age 62 +/- 7.2 years, 5 male and 3 female) were randomized to be tested in either a 20 mm inferiorly subluxed position or in a reduced position. The long head of the biceps tendon was held near the musculotendinous junction with a novel cryogenic clamp. Traction on the long head of the biceps tendon was applied at a fast rate of 12.7 cm/sec with a servohydraulic testing machine. A load cell was used to monitor the biceps tendon load. After testing to failure, the presence or absence of a type II SLAP lesion was determined by 2 experienced shoulder surgeons masked to the test group. The production of type II SLAP lesions differed significantly (P = .03) between reduced shoulders (2 SLAP lesions out of 8 tests) and the shoulders with inferior subluxation (7 SLAP lesions out of 8 tests). This experiment has shown that traction on the biceps tendon in this biomechanical model can reproducibly create type II SLAP lesions, and inferior subluxation facilitates the generation of such lesions.

Assessment of outcome in shoulder arthroplasty.

This article discusses outcome measures for the patient requiring shoulder arthroplasty and the weakness and strengths of various assessment tools in current use. The optimal method to measure the outcome of patients with shoulder arthroplasty is yet to be defined; however, the ideal assessment should include measures of general health, a shoulder-specific assessment, and an assessment that is specific to the disease state for which shoulder arthroplasty is indicated. The authors also provide appendices with their recommended calculations for the elevation of the shoulder arthroplasty patient.

Mapping of linear antigenic determinants on glycoprotein C of herpes simplex virus type 1 and type 2 recognized by human serum immunoglobulin G antibodies.

Using membrane-based dekapeptides, the reactivity of human serum antibodies with linear antigenic determinants of herpes simplex virus (HSV) type 1 and type 2 glycoprotein C (gC-1, gC-2) was studied by pep scan and immunodot assay. The entire coding sequences of gC-1 and gC-2 were screened for the presence of linear epitopes by pep scan. Peptides recognized in an HSV-1 type-specific manner were mainly identified within the N-terminal third and at the C-terminus of gC-1, whereas most type-common antibodies were directed against colinear peptides within the central parts of gC-1 and gC-2. The type-specific reaction of human sera with gC-2 peptides in pep scan was poor. Eight peptides identified as immunoreactive by pep scan were further tested in immunodot assay for their reactivity with a human serum panel. None of the eight HSV-negative sera gave positive results by immunodot assay. Positive reactions with gC peptides were found to be strongly age-dependent, i.e., the rate of positive reactions was significantly higher in HSV-positive adults than in HSV-positive children. Antibody reactivity with two type-common gC peptides was demonstrated in 17 out of 28 HSV-positive sera. A putative type-specific gC-2 peptide employed in immunodot assay was inconsistently recognized by human sera. Twenty HSV-positive sera reacted with at least 1 of 5 type-specific gC-1 peptides. Nine sera showing no reactivity with glycoprotein G of HSV-1 (gG-1) by immunobloting recognized type-specific gC-1 peptides in immunodot assay. Thus, gC-1 peptides might allow the detection of HSV-1-specific antibodies in individuals showing no reactivity with commonly employed HSV-1-specific diagnostic antigenes, i.e., purified or recombinant gG-1.

Cervical spine alignment in immobilized hockey players: radiographic analysis with and without helmets and shoulder pads.

OBJECTIVE: To establish the appropriate technique for cervical immobilization of the hockey player with an acute neck injury, we analyzed the alignment of the cervical spine in healthy volunteers with combinations of applied hockey equipment and assessed the amount of cervical spine motion possible in a secured hockey helmet. Our hypothesis was that there is a significant difference among various positions of the cervical spine with and without equipment and with active motion in a secured helmet. DESIGN: We analyzed lateral cervical spine radiographs of eight healthy male volunteers immobilized on a backboard with the following combinations of hockey equipment: shoulder pads and helmet, shoulder pads only, helmet only, no equipment, and neck flexion and extension with helmet and shoulder pads on and helmet secured to the backboard. SETTING: Large university hospital, tertiary care center. RESULTS: Cervical lordosis without equipment (control) was not significantly different than cervical lordosis with shoulder pads and helmet applied (p=0.31). Subjects with shoulder pads averaged 8.9 degrees more lordosis than did controls (p= 0.0002) and 6.6 degrees more lordosis than did subjects with shoulder pads and helmets (p=0.027). Subjects with shoulder pads and a helmet secured to the backboard were able to flex and extend the cervical spine 12.9 degrees compared with the control position (p =0.009). CONCLUSIONS: In an acute cervical spine injury involving an ice hockey player, we recommend immobilization in both the helmet and the shoulder pads, with removal of both pieces of equipment in a controlled hospital setting and only after initial radiographic examination. We also recommend securing the player's chin to prevent as much head and neck motion as possible during transport and transfers.