Evolution of Caulanthus amplexicaulis var. barbarae (Brassicaceae), a rare serpentine endemic plant: a molecular phylogenetic perspective.

Intra- and interspecific phylogenetic relationships of the rare serpentine endemic taxon Caulanthus amplexicaulus var. barbarae and related taxa in the "Streptanthoid Complex" of genera (Streptanthus, Caulanthus, Guillenia) were examined using nuclear ribosomal internal transcribed spacer (ITS) and chloroplast trnL intron sequences. Phylogenetic hypotheses generated from 81 variable ITS nucleotide sites and six variable trnL nucleotide sites indicate that Streptanthus and Caulanthus are nonmonophyletic groups. Caulanthus amplexicaulis var. barbarae and its more widespread nonserpentine sister taxon Caulanthus amplexicaulis var. amplexicaulis formed a distinct monophyletic group. Among the taxa in our study, C. amplexicaulis was most closely related to Streptanthus tortuosus. The ITS sequences supported monophyly of subgenus Euclesia, which includes the bulk of the serpentine endemics in the Streptanthoid Complex. The serpentine taxa were nonmonophyletic, occurring in at least three distinct clades, suggesting that tolerance to serpentine may be gained or lost through relatively few genetic changes. Intraspecific ITS1 and ITS2 sequence divergence within C. amplexicaulis (1.3-1.8%) was higher than in comparable species (0.0-0.3%); implications of this genetic differentiation for the conservation status of C. amplexicaulis var. barbarae are discussed. Evidence is presented that supports a "biotype depletion" model for the origin of this rare endemic taxon.

A poliovirus-susceptible transgenic mouse model as a possible replacement for the monkey neurovirulence test of oral poliovirus vaccine.

Two poliovirus-susceptible transgenic mouse (Tg PVR) strains, Tg1 and Tg21, were compared with the monkey test for their sensitivity to neurovirulence of live oral poliovirus vaccine (OPV). Intracerebral (i.c.) and intraspinal (i.s.) routes of inoculation were investigated to determine the most suitable combination of mouse strain and route. Evaluation of the mouse tests was performed using several indicators; clinical score and failure time were selected as the most efficient. Tg1 and Tg21 mice inoculated i.s. with type 2, and Tg21 mice inoculated i.s. with type 3 OPV were determined to be the most appropriate systems, whereas they are shown not to be suitable for type 1 OPV. The sensitivity of each of the two mouse models was at least equal to that of the monkey test, suggesting that these mouse systems might be considered as a potential replacement for the monkey test of OPV. However, more data are needed to establish regulatory criteria of acceptability for vaccine lots tested in Tg PVR mice. This is the first study conducted with Tg PVR mice with all three types of poliovirus vaccine preparations.

Microevolution of type 3 Sabin strain of poliovirus in cell cultures and its implications for oral poliovirus vaccine quality control.

Screening for sequence heterogeneities in Sabin Type 3 strains of attenuated poliovirus demonstrated mutations that consistently accumulate to significant levels following 10 passages in cultures of primary African green monkey kidney (AGMK) cells or continuous cultures of Vero cells. Fourteen newly identified mutations were quantified by mutant analysis by PCR and restriction enzyme cleavage in passages and in batches of commercial vaccines made in AGMK and Vero cells from the Sabin original (SO) seed virus and from a seed virus rederived by RNA plaque purification (RSO or "Pfizer" seed). Nine of the 14 mutations were reproducibly observed in more than one series of passages. Although 5 other mutations were observed in only one set of passages each, their content gradually increased to a high percentage, suggesting that all the mutations that we found accumulated consistently. SO-derived samples accumulated more mutations than did RSO-derived ones, and the number of mutations and the rates of their accumulation were higher in Vero than in AGMK cells. While the rates of accumulation of most mutations were higher when passaging was performed at 37 degrees, a U-->C transition at nucleotide 5832 occurred faster at 34 degrees, the temperature used for vaccine production. Analysis of Type 3 oral poliovirus vaccine (OPV) monopools made by six manufacturers found only 5 of these newly identified mutations in vaccine batches (nucleotides 3956, 4935, 5357, 5788, and 5832). Some of the mutations were found in trace amounts (less than 0.1%) while others were present at up to 1.8% levels. The pattern of these mutations was characteristic for the type of seed virus and the cell substrate but demonstrated no correlation with results of the monkey neurovirulence test. Therefore the only mutation occurring in Type 3 OPV which contributed to neurovirulence in monkeys was the previously described reversion at nucleotide 472. Quantitation of reversion at nucleotide 472 can be utilized for assessment of acceptability of vaccine lots, while other mutations can be used for monitoring the consistency of vaccine production.

Consistent selection of mutations in the 5'-untranslated region of oral poliovirus vaccine upon passaging in vitro.

We have previously found that upon passaging type 3 oral poliovirus vaccine (OPV) in cell cultures the proportion of revertants at nucleotide 472 rapidly increases [Chumakov et al.: Proceedings of the National Academy of Sciences of the United States of America 88:199-203 1991]. Systematic study on the accumulation of these revertants showed that it was dependent on the multiplicity of infection and the temperature at which virus was grown. Revertants at position 472 of type 3 OPV accumulated faster in vaccines derived from Sabin Original (SO) substrain than from RNA-plaque purified (RSO) substrain. The rate of accumulation of 472-C revertants differed among cell lines and was higher in overgrown cell cultures suggesting that host factors are involved in the selection of mutants. We also found that accumulation of mutants occurred in vitro at position 480 in type 1 and position 481 in type 2 OPV, making the selection for revertants in domain F of the 5'-noncoding region a general phenomenon for all three Sabin strains. Assessment of the abundance of these mutants may be used for evaluation of the quality of OPV lots.

Quantitative aspects of the mutant analysis by PCR and restriction enzyme cleavage (MAPREC).

Quantitation of virus revertants by PCR and restriction enzyme cleavage may give nonlinear results and, in some cases, produce artifacts caused by nucleotide misincorporation and heteroduplex formation, occurring during PCR. Modifications of the procedure allowed us to overcome these problems and develop a highly sensitive and reliable method of mutant quantitation. This procedure can be used to assess the quality of live vaccines and to study heterogeneity of viral and bacterial populations.

Osteomyelitis due to Pseudallescheria boydii.

This report describes an unusual opportunistic fungal infection in an immunocompetent young man who had no cutaneous involvement and whose infection was diagnosed 6 years after an accident. The unusual clinical presentation and difficulties in making a correct diagnosis are discussed and prophylactic antifungal chemotherapy is suggested.

Assessment of the viral RNA sequence heterogeneity for control of OPV neurovirulence.

By using sensitive mutant analysis by PCR and restriction enzyme cleavage we have found that among several positions that differ between the wild-type and attenuated type 3 poliovirus genomes, only two positions, 472 and 2493, showed variability in vaccine lots. Of these two, only position 472 correlates with neurovirulence in monkeys, while the abundance of revertants at position 2493 indicated the type of seed virus and the passage level. Conditions of cell culture influence the rate of mutant selection, suggesting that some cellular factor(s) may be involved in selection of 472-C. Determination of 472-C content predicts which vaccine lots would fail the monkey neurovirulence test. These results imply that the PCR method can be used for optimization of manufacturing conditions.

How iliotibial tract injuries of the knee combine with acute anterior cruciate ligament tears to influence abnormal anterior tibial displacement.

A knowledge of the patterns of injury to the components of the iliotibial tract allows a clearer interpretation of motion limits testing in patients with abnormal anterior tibial translation of the knee (anterior cruciate ligament-deficient knees). Eighty-two consecutive patients with acute knee injuries were classified as anteromedial-anterolateral rotatory instability (anterior cruciate ligament-deficient) based on the abnormal motion demonstrated by clinical examination tests for instability. At surgery, injuries to the intraarticular and extraarticular anatomic structures were identified and correlated to the abnormal grades of motion demonstrated by the knee motion limits examination. Tears of the anterior cruciate ligament occurred in 80 (98%) of the knees. However, the grade of abnormal motion demonstrated by the Lachman and pivot shift tests was quite variable. This variation did not correlate statistically with anterior cruciate ligament tears. Injuries to the anatomic components of the iliotibial tract were confirmed in 76 (93%) of the knees. These injuries correlated highly with variations in grades of abnormal motion detected by the following tests: lateral joint line opening at 30 degrees (r2 = 0.05); Lachman test (r2 = 0.08); pivot shift (r2 = 0.16); and anterior translation at 90 degrees of flexion (r2 = 0.34). Thus, injuries to the components of the iliotibial tract are thought to contribute to the variation in grades of abnormal motion observed in this complex subgroup of anterior tibial translation instabilities.

RNA sequence variants in live poliovirus vaccine and their relation to neurovirulence.

Mutant analysis by polymerase chain reaction and restriction enzyme cleavage (MAPREC) was used to study sequence heterogeneity and stability in attenuated poliovirus type 3 at positions in which the vaccine virus differs from its wild-type progenitor. Of seven genomic positions tested, only two (positions 472 and 2493) show nucleotide heterogeneity. Propagation of the vaccine virus in cell cultures leads to rapid selection of virus with reversions at these two positions of the genome. The relative abundance of reversions at position 472 correlates with the results of monkey neurovirulence tests, while the mutation at position 2493 is not directly associated with neurovirulence of the virus in monkeys. Instead, the abundance of mutations at the latter position correlates with the source of the seed virus and its passage level. These results further indicate that MAPREC at position 472 can be used to assess the quality of poliovirus type 3 vaccine.

The stabilizing function of passive shoulder restraints.

UNLABELLED: The static restraints of the scapulohumeral joint provide stability for the humeral head in the glenoid cavity, limit extremes of motion of the glenohumeral joint, and guide positioning of the humerus during normal shoulder movement. Eleven fresh-frozen cadaver shoulders of unknown age were attached to a shoulder motion device that allowed measurement of motion in three planes with an accuracy to 0.5 degrees. Four shoulders underwent motion analysis and seven were used for strain gauge analysis of the static scapulohumeral ligamentous restraints. The results of the motion analysis demonstrated that any attempt at simple motion (flexion, extension, abduction, internal or external rotation) resulted in coupled motion in two additional planes. The strain gauge data, expressed as a percent of total tension for each ligament tested, demonstrated a reciprocal tension-sharing relationship among all ligament components and a transference of tension among these components when original and new joint positions were compared. These data provide an in vitro model of shoulder restraint function to explain primary restraint, tension sharing, and transference of tension functions in the in vivo scapulohumeral joint. CLINICAL RELEVANCE: These principles of shoulder function have application in the treatment of instability and frozen shoulder syndrome, and provide an in vitro model to better understand static restraint function in the throwing mechanism.

Pigmented villonodular synovitis of the shoulder.

No characteristic clinical presentation of pigmented villonodular synovitis of the shoulder can yet be determined. Symptoms of discomfort and stiffness may appear insidiously or, in some cases, pigmented villonodular synovitis may be found incidentally during surgery for unrelated problems. Cystic and degenerative changes are more likely to occur in the shoulder than in joints with large synovial recesses such as the knee. Histologic findings parallel those in other joints. Optimal treatment appears to be early marginal excision for the localized form or total synovectomy for the diffuse form. The incidental finding of pigmented villonodular synovitis should not influence the decision to proceed with a preplanned reconstructive procedure. No experience with arthroscopic treatment or radiation therapy for diffuse pigmented villonodular synovitis of the shoulder has been reported.

Clinical presentation of complete tears of the rotator cuff.

To determine whether the presence and extent of a tear of the rotator cuff could be predicted on the basis of a patient's history, physical examination, and radiographic findings, detailed data from the histories and physical examinations of 103 patients who were known to have a tear of the rotator cuff were correlated with the radiographic and operative findings on these patients. An age-matched control group of fifty-one patients who had similar symptoms, but whose arthrograms showed normal results, was used to establish a baseline incidence of ten specific radiographic findings in the shoulder. Two discrete groups of patients who had a tear of the rotator cuff were identified. Twenty-eight patients (27 per cent) had a tear of a single tendon; the histories and the physical and radiographic findings in this group were consistent with a symptomatic local mechanical-impingement process in the shoulder. Sixty (80 per cent) of the seventy-five patients in the other group had a history of acute trauma to a shoulder. The patients in this second group were older and were non-athletic, and had not previously had symptoms that were severe enough to need treatment. These patients were subsequently found to have a complete tear of more than one of the tendons of the rotator cuff. Multiple radiographic findings in the shoulder and other coexisting orthopaedic conditions also were more common in these patients. In this group, we believe that acute trauma in a shoulder that had chronic degenerative changes, rather than localized mechanical impingement, caused the tendons to rupture.

Isolated chondral fractures of the knee.

Eighteen patients with isolated chondral fractures of the knee were reviewed to reevaluate the clinical signs and symptoms. No other conditions had been present to account for the symptoms. Most of the patients had significant injuries often involving a flexed knee. All patients had had symptoms and physical findings strongly suggestive of meniscal abnormality. Roentgenographic examinations were noncontributory. The lesions occurred in four distinct patterns. All were full thickness. Many of the lesions occurred on the posterior aspect of a femoral condyle, a location where they could be easily overlooked if the condyle were not examined with the knee in extreme flexion. Abutment of the tibial spine against the medial femoral condyle may be one cause of these injuries. The incidence of isolated chondral fractures was found to be higher than previously reported. A negative arthroscopic meniscal examination in a patient with symptoms and physical findings suggestive of meniscal abnormality should alert the physician to the possibility of an isolated chondral fracture.

The anatomy of the iliopatellar band and iliotibial tract.

Based on an extensive review of the literature and dissections of 17 fresh-frozen knee specimens, the authors divide the lateral fascia lata of the knee into two functional components: the iliopatellar band and the iliotibial tract. Aponeurotic, superficial, middle, deep, and capsulo-osseous layers contribute to these two functional components. The superficial layer of the iliotibial tract, combined with the deep, and capsulo-osseous layers, is hypothesized to function as an anterolateral ligament of the knee. The iliopatellar band provides stabilization of the patella against a medially directed force and is dynamically influenced by the vastus lateralis. The relationship of the iliotibial tract to extraarticular reconstructions of the knee with anterolateral rotatory instability is discussed.

Posterior shoulder approach.

A posterior shoulder surgical approach combines the subperiosteal detachment of the deltoid from the scapular spine, described by McWhorter, with a lateral extension to include the lateral deltoid splitting of Codman. The glenohumeral joint is superiorly approached between the supraspinatus and infraspinatus tendons, or inferiorly between the infraspinatus and teres minor tendons. This approach was used in 42 shoulders with rotator cuff tears or posterior instability without complications of infection, failure of deltoid healing, or compromise of suprascapular or axillary nerves. This combined surgical approach provides excellent exposure of the superior and posterior shoulder, which is difficult to obtain by anterior or superior approaches. This approach may be used for repair of rotator cuff tears, posterior instability, and displaced posterior glenoid fractures.

Treatment of acute anterolateral rotatory instability.

This article provides an account of the experience at the Hughston Orthopaedic Clinic in diagnosing and treating acute anterolateral rotatory instability of the knee. Clinical evaluation, surgical exposure and repair, and postoperative rehabilitation are detailed, with emphasis on an integrated approach to treatment, with the goal of restoring stability and function to the injured knee.

Acute combined posterior cruciate and posterolateral instability of the knee.

This report concerns 13 consecutive patients (13 knees) who underwent operative treatment for acute combined posterior cruciate and posterolateral instability due to combined injury to the posterior cruciate ligament and the arcuate ligament complex. Our purpose was to examine the method of diagnosis and the results in these patients. There were 12 males and 1 female (average age, 26 years). Five patients were injured in a motor vehicle accident, four in sports activities, and four in nonsports activities. The mechanism of injury was an anteromedial blow to the flexed knee in six patients, a fall onto the knee in two, and unknown in five patients. Eleven patients were available for follow-up evaluation (average, 56 months), and in each the result was rated as good, fair, or poor. In 10 patients (90%) the results were rated as good subjectively, in 11 (100%) as good functionally, and in 8 (73%) as good objectively. Injury to both the posterior cruciate ligament and the arcuate ligament complex can result from rotational force that can be due to a blow to the anteromedial aspect of the knee. Diagnosis can be made by a combined positive response to the posterior drawer test, the anterior drawer test performed with the tibia in internal rotation, the abduction and adduction stress tests performed with the knee in full extension, the posterolateral drawer test, and the external rotation-recurvatum test. In a knee with concomitant injury to the posterior cruciate ligament and the arcuate ligament complex that requires surgical repair, all injured structures should be explored and repaired to ensure a subjectively, objectively, and functionally good result.

Shoulder posterior subluxation.

The records of 21 patients with chronic recurrent posterior subluxation were reviewed to document postoperative stability and level of athletic participation after opening wedge posterior scapular osteotomy and associated soft tissue procedures. At an average of 39.9 months after surgery, we objectively reevaluated 17 males and 2 females (from 16 to 46 years old). Patients with posterior instability caused by a direct trauma stabilized and effectively returned to athletic participation following osteotomy. Patients with posterior stability resulting from muscular contraction required additional soft tissue procedures for stability and effective return to athletics. Congenitally or habitually lax shoulders did not stabilize in this series. This study suggests that opening osteotomy is indicated for single plane, posterior instability which results from direct trauma or muscular contraction, and for combined anterior-posterior instability. Opening osteotomy is contraindicated in congenitally or habitually lax shoulders. A descriptive classification system which groups shoulders according to injury force and direction of instability facilitates preoperative prediction of subsequent glenohumeral joint stability and athletic participation or level of nonsportive activity.