Antigenic domains of the HIV-1 vif protein as recognized by human sera and murine monoclonal antibodies.

To analyze the vif antibody response in individuals infected with the human immunodeficiency virus type 1 (HIV-1) and to determine antigenic epitopes on the vif protein, 104 HIV-1+ sera were screened for reactivity with a recombinant vif protein; 30 (28.8%) of these sera recognized the recombinant vif protein in immunoblot and were employed, together with 17 HIV-1/vif-negative control sera, in an enzyme immunoassay (EIA)-based epitope scanning assay with 183 overlapping decapeptides that covered the complete amino acid sequence of the HIV-1 vif protein (strain BH10). Of the 30 HIV-1/vif+ sera, 87% reacted with decapeptides comprising the two following epitopes: IEWRKKRY (vif amino acids 87-94) or DRWNKPQ (vif amino acids 172-178). The two epitopes were 89% and 100% conserved among different HIV-1 strains and their antigenicity could be confirmed by computer-assisted predictions of vif antigenic determinants. All the sera reactive with recombinant vif protein and with vif peptides originated from patients in CDC stages III or IV. Two murine anti-vif monoclonal antibodies reacted only with the seven C-terminal amino acids of the vif protein (SHTMNGH), which were not recognized by any of the human sera. Our results may be useful for further studies of vif seroreactivity and for the production of anti-vif mono- or polyclonal antibodies using vif peptides.

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.

Quantification of HIV-1 proviral DNA and analysis of genomic diversity by polymerase chain reaction and temperature gradient gel electrophoresis.

A competitive polymerase chain reaction/temperature gradient gel electrophoresis (PCR/TGGE) protocol was developed for exact quantification of HIV-1 proviral DNA copy numbers in clinical samples. An internal standard (ST) that differs from wildtype-sequences only by a single base exchange was used as a competitor in PCR. Quantification of HIV-1 target sequences was achieved by coamplification of defined copy numbers of ST with wild type target sequences, hybridization of PCR products to a strand-specifically labelled probe, separation of ST and wildtype sequences by TGGE, and determination of the ratio of wildtype and standard sequences by densitometric scanning. Effects of sample preparation, DNA extraction and white blood cell counts were minimized by the additional quantification of beta-globin sequences. With this technique, it was possible to determine precisely the number of HIV target sequences as compared to the number of beta-globin gene copies with a detection limit of two HIV-1 proviral copies. Forty-four peripheral blood mononuclear cell (PBMC) extracts from 39 HIV-1 infected patients were analyzed by PCR/TGGE. HIV-1 proviral DNA levels ranged between 2 and 24190 HIV-copies/10(6) beta-globin copies. In general, patients in the advanced stages of disease and/or with low CD4 counts had much higher proviral DNA levels than patients in early stages or with high CD4 counts. In patients from whom consecutive samples were obtained, progression of disease correlated with a greater than tenfold rise of HIV-copies/10(6) beta-globin copies. Compared to other recently published protocols for proviral DNA quantification, this experimental approach allows in addition direct demonstration of mutations within the amplified region. The competitive PCR/TGGE protocol described in this study is suitable for monitoring fluctuations of proviral DNA levels and to identify the genomic diversity of HIV target sequences simultaneously in one assay.

Ibuprofen improves survival and neurologic outcome after resuscitation from cardiac arrest.

Post-ischemic inflammatory changes in the central nervous system (CNS) following cardiac arrest and resuscitation are potentially responsible for ultimate survival and much of the neurologic damage, producing greater morbidity and mortality in successfully resuscitated patients. This study was undertaken to assess the non-steroidal anti-inflammatory agent, ibuprofen, in a controlled and monitored experimental model of canine cardiac arrest and resuscitation. With the investigator blinded as to the intervention, eight of 21 dogs were randomly assigned to receive ibuprofen as an i.v. bolus (10 mg/kg) and a 6-h i.v. infusion (5 mg/kg per h). The other 13 dogs received an equivalent volume of 0.9% NaCl to serve as controls. No statistically significant differences between the two groups were detected in any pre-arrest variables. All 21 dogs were successfully resuscitated. At 24 h, dogs receiving ibuprofen exhibited 100% survival, while control dogs exhibited only 54% survival (P = 0.03). The majority of deaths for the control group occurred within the first 6 h. Neurologic deficit scores were assigned at 1, 2, 6 and 24 h after resuscitation. A general trend occurred such that dogs treated with ibuprofen improved over time, while the control dogs remained severely impaired. A significant difference in neurologic deficit score was detected at 6 h (P = 0.01). At 24 h the ibuprofen group exhibited minimal neurologic deficit (5.9 +/- 3.2), and the control group exhibited significantly more severe neurologic impairment (52.2 +/- 13.0, P = 0.01). These results suggest that ibuprofen may be helpful in the pharmacologic management of cardiac arrest as a means of increasing survival and decreasing neurologic impairment.

Divergent single-column fractures of the distal part of the humerus.

We report an unusual intra-articular fracture of the distal part of the humerus that was seen in five patients, including one who had the fracture bilaterally. The fractures were characterized by three features. First, the fractures were initiated in the trochlear groove as a result of a direct impact on the olecranon, which divided the trochlea and then split the two columns of the humerus divergently. Second, the fractures occurred exclusively in adolescents and young adults (average age, fifteen years old; range, thirteen to twenty years old). Third, all of the fractures were seen in patients who had a large fossa or septal aperture between the coronoid and olecranon fossae. Four of the fractures involved the right side and two, the left. There were three fractures of the lateral column and three of the medial column. Because the periosteum, the capsule, and the ligaments remained intact despite intra-articular displacement of the distal part of the humerus, these fractures were also characterized by inherent proximal stability. The fractures were treated with closed reduction and percutaneous internal fixation to reduce the displacement between the two halves of the trochlea. All of the fractures united. Four patients (five elbows) regained full motion by eight months; one patient was lost to follow-up. Current classification systems that describe single-column fractures of the distal part of the humerus should be modified to include this unusual fracture pattern.

Arthroscopic capsular release for the stiff shoulder. Description of technique and anatomic considerations.

The anatomic proximity of several neurovascular structures remains a major concern to the surgeon interested in performing arthroscopic capsular release. We evaluated the anatomic relationships between the released capsule and the axillary nerve, posterior circumflex humeral artery, and brachial artery in a frozen cadaveric model. With the aid of electrocautery, seven cadaveric shoulders underwent complete arthroscopic capsular release. The release was performed circumferentially, approximately 1 cm lateral to the glenoid rim. All shoulders were subsequently frozen and sectioned through the plane of the capsular release while the shoulder was maintained in the lateral arthroscopic position (45 degrees of abduction and 20 degrees of flexion). Anatomic dissection revealed an average distance from the capsular release to the axillary nerve of 7.04 mm (95% confidence interval, 5.62, 8.47), to the posterior circumflex humeral artery of 8.2 mm (95% confidence interval, 6.41, 9.99), and to the brachial artery of 15.97 mm (95% confidence interval, 9.85, 22.09). As the axillary nerve was followed medially from the released capsule, the inferior border of the subscapularis muscle became interposed between the capsule and the axillary nerve. This limited anatomic study shows that a relatively safe margin between the capsule and the neighboring neurovascular structures can be obtained by releasing the capsule within 1 cm of the glenoid rim.

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.

Validation of the lift-off test and analysis of subscapularis activity during maximal internal rotation.

We used electromyographic analysis to determine the muscle activity of the shoulder muscles during the lift-off test and during resisted internal rotation. The activity in the upper and lower subscapularis muscle during a lift-off test from the region of the midlumbar spine was approximately 70% of maximal voluntary contraction. This level was significantly higher than for all the other muscles tested (P < 0.05). The lift-off test with the hand placed in the region of the midlumbar spine resulted in one-third more electromyographic activity in the subscapularis muscle than when the test was modified and performed with the hand at the buttocks region. A resisted lift-off test resulted in higher activities in all the muscles, but only a small increase in the pectoralis major muscle. The pectoralis major muscle was significantly more active during resisted internal rotation with the arm in front of the body. Comparison of activity in the upper subscapularis with that in the lower subscapularis muscle showed no significant differences during any of the tests. This study documents the importance of the subscapularis muscle during the lift-off test and suggests that other potential internal rotators of the humerus have a limited role in maintaining internal rotation when the arm is placed behind the back.

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.

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.

Fractures of the acromion process: a proposed classification system.

A review of 27 fractures of the acromion process during a 15-year period revealed five distinct types that were classified into three groups. Stress fractures are rare, do not result from acute trauma, and gain little benefit from nonoperative treatment. Type I fractures are minimally displaced. Type IA fractures are avulsion fractures and heal rapidly. Type IB fractures result from direct trauma to the extremity, and are minimally displaced. Most heal with nonoperative treatment. Type II fractures are displaced laterally, superiorly or anteriorly and do not reduce the subacromial space. Most are pain free with full motion after 6 weeks of nonoperative treatment. Type III fractures reduce the subacromial space. This may occur by an inferiorly displaced acromion fracture, or an acromion fracture associated with an ipsilateral, superiorly displaced glenoid neck fracture. Patients in this group sustained significant trauma to the involved extremity. All type III fractures treated nonoperatively develop significant limited shoulder motion with pain, suggesting that early surgical intervention may be indicated.

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.

Surgical treatment of shoulder injuries in tennis players.

There are a number of disorders that affect the shoulder of the tennis player. The majority of these disorders are approached conservatively at first, and surgery is generally reserved for those with advanced stages of disease, or those who fail conservative treatment. Most surgical procedures for the shoulder are done open; however, arthroscopic techniques are advancing rapidly, and are expected to eventually supersede open surgical procedures. In either case, the postoperative rehabilitation program is an essential part of the surgical treatment of these disorders, and should not be neglected.

Allograft meniscus transplantation.

At this time, meniscal allograft transplantation remains an investigational procedure with very limited indications. To date, no work has shown that the transplanted meniscus is capable of protecting and, preserving the hyaline cartilage of the knee joint. The technical aspects of the procedure have been established and are reproducible. Furthermore, it is apparent that a systemic rejection phenomenon does not seem to occur, and the transplanted meniscus is capable of healing. MR imaging appears to be the best method of assessing postoperative position of the transplanted meniscus in the knee. If the transplanted meniscus cannot be maintained in an anatomic position during weight bearing, it is unlikely to have any functional role. Questions remain with regard to the best way to preserve and sterilize the meniscus and whether the transplanted allograft meniscus is capable of assuming the multifaceted role of the normal meniscus in the knee. As more work is conducted, these questions will be answered, and a better understanding of the efficacy of this novel technique will be achieved.

A nurse's right to refuse a patient care assignment.

Ethics is a set of moral principles or values--a guiding philosophy for behavior. Ethical dilemmas in the health care setting occur daily. Perioperative nurse managers need to consider basic ethical principles when resolving these dilemmas, and they must keep in mind that solutions need to serve the best interests of all people involved in given situations. This article discusses criteria by which a nurse can refuse a patient care assignment and those by which a nurse manager can require that a nurse perform a patient care assignment.

Measuring outcomes in shoulder arthroplasty.

No standard assessment for the patient with a shoulder arthroplasty has been universally accepted to date. Traditional assessment tools can be divided into three levels of resolution including: (1) assessments of the quality of life and general health, (2) global shoulder assessments, and (3) assessments for a particular disorder of the shoulder. In this article, examples of each of these groups are discussed. Each of these levels of sensitivity offers a different perspective on the outcome of shoulder arthroplasty and until the ideal, universal outcome measure is developed, outcomes should be reported using assessments in each of these levels.