Histone acetyltransferase CBP promotes function of SCF FBXL19 ubiquitin E3 ligase by acetylation and stabilization of its F-box protein subunit.

Ubiquitin E3 ligases mediate ubiquitination and degradation of intracellular proteins. We have shown that a relatively new Skp, Cullin, F-box (SCF) protein E3 ligase, SCF FBXL19, has an anti-inflammatory effect and controls actin cytoskeleton dynamics via targeting cell membrane receptor and small GTPases for their ubiquitination and degradation, but the molecular regulation of its subunit FBXL19 stability remains unclear. Here we show that FBXL19 degradation is controlled by the balance between its ubiquitination and acetylation. FBXL19 is an unstable protein with a half-life of ∼3 h. FBXL19 can be polyubiquitinated, and the proteasome inhibitor MG-132 prolongs FBXL19 half-life, suggesting that FBXL19 degradation is mediated in the ubiquitin-proteasome system. FBXL19 can also be acetylated, and enhancing acetylation of FBXL19 by a deacetylase inhibitor reduces FBXL19 ubiquitination levels. Acetylation-mimic FBXL19 mutant exhibits a longer half-life than wild type. An acetyltransferase CBP catalyzes acetylation of FBXL19. Inhibition or down-regulation of CBP reduces FBXL19 stability, whereas it is increased in CBP-overexpressing cells. Taken together, the data indicate that CBP-mediated acetylation reduces ubiquitination and stabilizes FBXL19. Further, we demonstrate that FBXL19 targets small GTPase Cdc42 for its ubiquitination and degradation, whereas this effect is reversed by inhibition of CBP, suggesting that CBP increases the effect of SCF FBXL19 E3 ligase through acetylation and stabilization of FBXL19. Our study reveals a new molecular model for regulation of SCF E3 ligase function by acetylation and stabilization of its subunit F-box protein.-Wei, J., Dong, S., Yao, K., Martinez, M. F. Y. M., Fleisher, P. R., Zhao, Y., Ma, H., Zhao, J. Histone acetyltransferase CBP promotes function of SCF FBXL19 ubiquitin E3 ligase by acetylation and stabilization of its F-box protein subunit.

Lack of efficacy of levetiracetam in oromandibular and cranial dystonia.

OBJECTIVE: To determine the efficacy of levetiracetam in oromandibular or cranial dystonia. METHODS: We recruited seven subjects with oromandibular or cranial dystonia. Five completed the study, median age was 71 years (range 42-79 years), median disease duration was 12 years (range 2-30 years). Participants were randomized to receive levetiracetam or placebo and were then crossed over. They titrated up to a total daily dose of 4000 mg or the maximum tolerated dose over 3 weeks and maintained that dose for another 3 weeks. The primary endpoint was the percent change of the eyes, mouth, speech, and swallowing Burke-Fahn-Marsden (BFM) subscores from baseline to weeks 6 and 14. Additional endpoints included the BFM subscore at weeks 3 and 11, and the global dystonia severity (GDS) subscore at weeks 3, 6, 11, and 14, as well as all adverse side effects. RESULTS: The mean percent increase in the BFM subscore (placebo: 31.25%, levetiracetam: 12.16%) was not significantly different between the two arms according to the Friedman analysis. The Wilcoxon signed-rank test showed that these percent changes were not significant, indicating that there was no statistical clinical worsening in either arm. The mean percent change of the BFM subscore at weeks 3 and 11 and the mean percent change of the GDS subscore at weeks 3, 6, 11, and 14 were not significantly different between the two arms, and the Wilcoxon signed-rank test did not show statistical significance. CONCLUSION: Levetiracetam does not appear to be efficacious in patients with oromandibular or cranial dystonia.

Pretransplant IgG reactivity to apoptotic cells correlates with late kidney allograft loss.

Preexisting serum antibodies have long been associated with graft loss in transplant recipients. While most studies have focused on HLA-specific antibodies, the contribution of non-HLA-reactive antibodies has been largely overlooked. We have recently characterized mAbs secreted by B cell clones derived from kidney allograft recipients with rejection that bind to apoptotic cells. Here, we assessed the presence of such antibodies in pretransplant serum from 300 kidney transplant recipients and examined their contribution to the graft outcomes. Kaplan-Meier survival analysis revealed that patients with high pretransplant IgG reactivity to apoptotic cells had a significantly increased rate of late graft loss. The effect was only apparent after approximately 1 year posttransplant. Moreover, the association between pretransplant IgG reactivity to apoptotic cells and graft loss was still significant after excluding patients with high reactivity to HLA. This reactivity was almost exclusively mediated by IgG1 and IgG3 with complement fixing and activating properties. Overall, our findings support the view that IgG reactive to apoptotic cells contribute to presensitization. Taking these antibodies into consideration alongside anti-HLA antibodies during candidate evaluation would likely improve the transplant risk assessment.

Disaster, Catastrophe, and Local Persistence of the Sea Palm Postelsia palmaeformis.

Two components of natural disturbance, its local intensity and frequency beyond a threshold level, limit a marine benthic alga to wave-swept shores. Transplant experiments indicate that the limited distribution is not due to physiological restriction. Instead, it requires predictable annual disturbance of moderate intensity for local persistence.

Species Introduction in a Tropical Lake: A newly introduced piscivore can produce population changes in a wide range of trophic levels.

Probably in early 1967, a piscivore from South America, Cichla ocellaris, was introduced to Gatun Lake in the Panama Canal Zone. As this predator population spread through the lake, the initial effect was dramatic reductions in almost all secondary consumers. These species reductions produced, in turn, second- and third-order changes at other trophic levels of the ecosystem. The resulting changes in the lake community can be seen best by examining the general Gatun Lake food web. The decrease in numbers of the important planktivore Melaniris has resulted in changes within the zooplankton community, as illustrated by the cladoceran Ceriodaphnia. The tertiary-consumer populations, such as tarpon, black terns, kingfishers, and herons, formerly dependent on small fishes for food, appear less frequently in the Cichla areas of the lake. There has also been, possibly, a resurgence of the local mosquito populations (which are malaria vectors), caused by the reduction in the populations of insect-eating fishes. Even the primary producers may be affected by this introduction. Although at present the Gatun Lake ecosystem is undergoing rapid changes, we anticipate an eventual return to some form of equilibrium. However, it will be some time before we can evaluate the permanence or transience of the many changes produced in the trophic levels by the introduction of a single, top-level predator to this lake system.

A health assessment of high status Christian burials recovered from the Roman-Byzantine archeological site of Elaiussa Sebaste, Turkey.

The purpose of this study is to assess the state of health of 116 individuals whose remains were excavated from Byzantine period burials underneath the floor of an important Christian basilica from the site of Elaiussa Sebaste, Turkey. Elaiussa Sebaste was a Mediterranean coastal community, which began as a Roman town and continued as an early Christian Byzantine community until the end of the 7th century AD. The burials date from the middle of the 6th through the middle of the 7th centuries AD. We attempt to determine how high social status has influenced the type and frequency of skeletal lesions exhibited in this sample. All strata of this population show a number of chronic and acute health problems as indicated by skeletal lesions. Yet, only the frequency of degenerative joint disease (DJD) differs by sex, with males exhibiting a higher rate of DJD than females, p=0.09. There is no difference in the frequency of trauma among adult males and females. Non-specific skeletal lesions (cribra orbitalia, porotic hyperostosis, and periostitis) often associated with dietary and general stressors, but also with specific systemic diseases, are common in both sexes. The sub-adults primarily exhibit periostitis of the long bones and do not show skeletal lesions specific to malaria. It seems that high social ranking did not prevent serious ailments from affecting the health of individuals living in the Elaiussa Sebaste community.

Pericardial tamponade, a new complication of amyloid heart disease.

With advancing age of the population and with echocardiographic means of diagnosis, amyloid disease of the heart is of increasing clinical interest. Advanced age, restrictive myocardiopathy, arrhythmias, and conduction disorders are familiar features of this disease. A 92 year old man with past history of hemiblock followed by complete heart block and transvenous pacemaker was admitted to the hospital because of increasing fatigue and the abrupt development of dyspnea. Examination revealed paradoxic pulse, markedly elevated central venous pressure, and echocardiographically demonstrated large pericardial effusion. Shortly after admission signs of tamponade developed; 1,000 ml of pericardial fluid was removed with prompt relief of dyspnea dna disappearance of paradoxic pulse and return of central venous pressure to normal. However, dyspnea soon recurred and subsequent hemodynamic measurements indicated increased right ventricular and left ventricular filling pressures. Echocardiography revealed no recurrent effusion or ventricular hypokinesis. Left ventricular ejection fraction by radionuclide ventriculogram was 64 percent. Echocardiography revealed ventricular wall thickening, normal chamber size, and glittering, sparkling myocardial echoes. On postmortem examination, there was extensive myocardial amyloidosis. There was no evidence of constrictive pericarditis or recurrent effusion. The unique aspect of this case was the combined presence of restrictive myocardiopathy and pericardial tamponade. To our knowledge, no previous case of tamponade due to amyloid heart disease had been reported.

Lung volume reduction surgery alters management of pulmonary nodules in patients with severe COPD.

OBJECTIVE: To examine the role of lung volume reduction surgery (LVRS) in expanding the treatment options for patients with single pulmonary nodules and emphysema. METHODS: Retrospective review of all patients undergoing LVRS at the University of Michigan between January 1995 and June 1996. Those undergoing simultaneous LVRS and resection of a suspected pulmonary malignancy formed the study group and underwent history and physical examination, pulmonary function tests, chest radiography, and high-resolution CT of the chest. If heterogeneous emphysema was found, cardiac imaging and single-photon emission CT perfusion lung scanning were performed. All study patients participated in pulmonary rehabilitation preoperatively. Age- and sex-matched patients who had undergone standard lobectomy for removal of pulmonary malignancy during the same period formed the control group. RESULTS: Of 75 patients who underwent LVRS, 11 had simultaneous resection of a pulmonary nodule. In 10 patients, the nodules were radiographically apparent with 1 demonstrating central calcification. Histologic evaluation revealed six granulomas, two hamartomas, and three neoplastic lesions (one adenocarcinoma, one squamous cell, and one large cell carcinoma). Preoperative FEV1 was 26.18+/-2.49% predicted in the LVRS group and 81.36+/-6.07% predicted (p=0.000001) in the control group, and the FVC was 65.27+/-5.17% predicted vs 92.18+/-5.53% predicted (p=0.002). Two LVRS patients had a PaCO2 >45 mm Hg while 11 exhibited oxygen desaturation during a 6-min walk test. Postoperative complications occurred in two LVRS patients and three control patients. The mean length of stay in the LVRS group (7.55+/-1.10 days) was not different than in the control group (8.81+/-1.56 days). Three months after LVRS and simultaneous nodule resection, FEV1 rose by 47%, FVC by 25%, and all study patients noted less dyspnea as measured by transitional dyspnea index. CONCLUSIONS: Simultaneous LVRS and resection of a suspected bronchogenic carcinoma is feasible and associated with minimal morbidity and significantly improved pulmonary function and dyspnea.

Weight gain after lung volume reduction surgery is not correlated with improvement in pulmonary mechanics.

STUDY OBJECTIVES: Malnutrition and low body weight are common in patients with emphysema. Previous work has demonstrated correlation between severity of airflow obstruction and body weight. Lung volume reduction surgery (LVRS) is a recent advance in the treatment of patients with severe emphysema that results in improved pulmonary function. We formed the hypothesis that improved lung mechanics after LVRS would result in body weight gain. DESIGN: Retrospective chart review. PATIENTS: All patients who underwent bilateral LVRS for severe emphysema at the University of Michigan between January 1995 and April 1996 were eligible for the study. MEASUREMENTS AND RESULTS: Pulmonary function and body weight were measured preoperatively and at 3, 6, and 12 months postoperatively for patients who underwent bilateral LVRS between January 1995 and April 1996. The average weight gain in 38 patients returning for 12 months of follow-up was 3.8 +/- 0.9 kg, or 6.2% of the preoperative weight. Women gained significantly more weight than men (9.2 vs 2.2%, respectively) at 1 year. Interestingly, there was no correlation between change in weight and postoperative change in FEV(1), FVC, residual volume (RV), total lung capacity (TLC), or RV/TLC at 12 months. However, there was a statistically significant correlation between weight gained and improvement in diffusion of carbon monoxide measured 12 months postoperatively. CONCLUSIONS: This study shows that patients with severe emphysema gain weight after LVRS. These changes were independent of changes in pulmonary mechanics but may be a result of improved gas exchange. These findings provide further information about benefits of LVRS in patients with advance emphysema that are beyond simple changes in pulmonary function.

The clinical pharmacology of the adenosine deaminase inhibitor 2'-deoxycoformycin.

2'-deoxycoformycin (2'-dCF; Pentostatin), a stoichiometric inhibitor of mammalian adenosine deaminase (ado deaminase), exhibits immunosuppressive and antilymphocytic activity in animal test systems. A clinical pharmacology/phase I study of 2'-dCF administered as a single agent has been completed (18 patients). Dose levels ranged from 0.1 mg/kg X 1 to 0.25 mg/kg/day X 5; ado deaminase and 2'-dCF were measured spectrophotometrically. Plasma decay curves were bi-exponential (alpha and beta t 1/2 values about 1 and 10 h respectively). Recovery of unchanged 2'-dCF from urine (48 h) was 32%--48% of the administered drug. Major toxic manifestations were lymphocytopenia (all patients) and urate nephropathy (1 patient, with subsequent patients in the series receiving allopurinol, 300 mg/day). Three partial responses were seen in seven patients with acute lymphocytic leukaemia receiving 0.25 mg 2'-dCF/kg/day X 5.

Intertidal community structure : Experimental studies on the relationship between a dominant competitor and its principal predator.

Along exposed rocky intertidal shorelines of western North America the mussel Mytilus californianus exists as a characteristic, well-defined band. Measurements at Mukkaw Bay and Tatoosh Island, Washington State, suggest that the upper limit to distribution is constant. The lower limit is also predictably constant, as judged by photographs of the same areas taken up to 9 years apart. The band of mussels is formed by larval recruitment to a variety of substrates, especially the filamentous red alga Endocladia muricata. From the settlement site, if the mussels survive a series of predators including the starfish Pisaster ochraceus and a variety of carnivorous gastropods (Thais spp.), the mussles may be washed inward or migrate (be pushed) downward.When Pisaster was removed manually, the zonation pattern changed rapidly. Mussels advanced downward at Mukkaw Bay a vertical distance of 0.85 m in 5 years. No movement was observed on 2 adjacent control sites. At Tatoosh Island a maximum displacement of 1.93 m has been observed in 3 years; the slope there is 40°. Again, there was no change at control sites with Pisaster. At Mukkaw Bay over 25 species of invertebrates and benthic algae are excluded from occupancy of the primary substratum by mussels. The ecological dominance of mussels is discussed; predation is shown to enhance coexistence among potential competitors. A survival curve for Pollicipes polymerus indicates that the time course for interspecific competitive exclusion may be long (76 months). The clarity of the biological interrelationships and the constancy of pattern through time provide no support for the contention that intertidal communities are physically-controlled.

Anterior cruciate ligament reconstruction using freeze-dried, ethylene oxide-sterilized, bone-patellar tendon-bone allografts. Two year results in thirty-six patients.

Thirty-six of 44 patients (82%) who underwent ACL reconstruction using freeze-dried, ethylene oxide-sterilized, bone-patellar tendon-bone allografts were evaluated at least 2 years postoperatively. A detailed subjective evaluation using the Lysholm scale was recorded as well as a functional evaluation using the Tegner activity scale. All of the patients received a detailed physical examination that included testing with the KT-1000 ligament arthrometer and the Cybex dynamometer. Complete chart reviews and radiographic evaluations were also obtained. Only 17 patients were considered to be functionally successful and performing at their desired activity level. The average KT-1000 showed a side-to-side difference of 5.9 mm at 30 pounds for the successful group and 7.9 mm for those who had functional failure. The Lysholm scores were 91.6/100 versus 61.1/100 in the failures. Eight patients (22%) at repeat surgery were noted to have complete dissolution of the graft. Large femoral cysts were noted radiographically in all of these patients. It was concluded that freeze-dried, ethylene oxide-sterilized, bone-patellar tendon-bone allografts have a high failure rate and cannot be recommended for ACL reconstruction.

In vivo measurement of anterior tibial translation using continuous passive motion devices.

Early motion protocols following anterior cruciate reconstruction often use continuous passive motion devices. There is concern that these devices may induce undesired anterior translation of the tibia and resulting graft stretching or rupture. This study measured the amount of anterior tibial translation that occurred during one cycle in 10 different brands of continuous passive motion devices. Five patients with ACL deficient knees participated in this study. Anterior translation was recorded by using an electrogoniometer with four degrees of freedom (Knee Signature System). Anterior translation measurements were also recorded for a 20 pound Lachman test in these same five patients using the Knee Signature System. Two of the devices showed anterior translation measurements that approached the recorded 20 pound Lachman values. These two devices had a high calf bar for the primary support of the leg. The results indicate that, when using a continuous passive motion device for early postoperative management of the reconstructed ACL in a patient, use of a calf-supporting type of continuous passive motion could induce an undesired strain of the healing graft.

An analysis of anterior cruciate ligament reconstruction in middle-aged patients.

The purpose of this study was to evaluate the results and complications of anterior cruciate ligament surgery in middle-aged patients. Forty-five consecutive patients over 40 years old (average age, 44.6 years) who had arthroscopically assisted anterior cruciate ligament reconstructions with midthird patellar tendon autografts were evaluated. The patients returned for interviews, physical examinations, radiographs, Biodex dynamometer strength testing, and KT-1000 arthrometer testing at an average of 37 months after their surgeries (range, 24 to 96 months). The mean Lysholm and Gillquist score was 91, which corresponds to symptoms only with vigorous activity. The overall scores from the International Knee Documentation Committee form were 29 (64%) normal or nearly normal and 2 (4%) severely abnormal. Side-to-side differences as determined by the KT-1000 arthrometer were < or = 3 mm in 31 of 40 patients (78%), between 3 and 5 mm in 4 patients (10%), and > 5 mm in 5 patients at 30 pounds of anterior displacement. Seventy-six percent of the patients (N = 34) returned to their preoperative activity levels. Three patients required repeat arthroscopic surgery for persistent knee pain and two patients had graft ruptures. This study shows that when middle-aged patients undergo surgery, their results can be successful and satisfying to a degree similar to those of younger patients.

A neural model of cortico-cerebellar interactions during attentive imitation and predictive learning of sequential handwriting movements.

Much sensory-motor behavior develops through imitation, as during the learning of handwriting by children. Such complex sequential acts are broken down into distinct motor control synergies, or muscle groups, whose activities overlap in time to generate continuous, curved movements that obey an inverse relation between curvature and speed. How are such complex movements learned through attentive imitation? Novel movements may be made as a series of distinct segments, but a practiced movement can be made smoothly, with a continuous, often bell-shaped, velocity profile. How does learning of complex movements transform reactive imitation into predictive, automatic performance? A neural model is developed which suggests how parietal and motor cortical mechanisms, such as difference vector encoding, interact with adaptively timed, predictive cerebellar learning during movement imitation and predictive performance. To initiate movement, visual attention shifts along the shape to be imitated and generates vector movement using motor cortical cells. During such an imitative movement, cerebellar Purkinje cells with a spectrum of delayed response profiles sample and learn the changing directional information and, in turn, send that learned information back to the cortex and eventually to the muscle synergies involved. If the imitative movement deviates from an attentional focus around a shape to be imitated, the visual system shifts attention, and may make an eye movement, back to the shape, thereby providing corrective directional information to the arm movement system. This imitative movement cycle repeats until the cortico-cerebellar system can accurately drive the movement based on memory alone. A cortical working memory buffer transiently stores the cerebellar output and releases it at a variable rate, allowing speed scaling of learned movements which is limited by the rate of cerebellar memory readout. Movements can be learned at variable speeds if the density of the spectrum of delayed cellular responses in the cerebellum varies with speed. Learning at slower speeds facilitates learning at faster speeds. Size can be varied after learning while keeping the movement duration constant (isochrony). Context-effects arise from the overlap of cerebellar memory outputs. The model is used to simulate key psychophysical and neural data about learning to make curved movements, including a decrease in writing time as learning progresses; generation of unimodal, bell-shaped velocity profiles for each movement synergy; size and speed scaling with preservation of the letter shape and the shapes of the velocity profiles; an inverse relation between curvature and tangential velocity; and a Two-Thirds Power Law relation between angular velocity and curvature.

Pulmonary rehabilitation for the elderly.

The elements of a pulmonary rehabilitation program require a variety of different skills. However, the number of people involved in a rehabilitation program will vary with the clinical setting and the number of patients served. In a large program, a physician, respiratory nurse, physical and occupational therapist, psychologist, social worker, respiratory therapist, and dietitian might all be involved on a full- or part-time basis. In other settings, two or three individuals, mostly working part-time, may be the entire team. Pulmonary rehabilitation may be performed on an outpatient basis, in a group practice setting, or in an inpatient hospital unit. Whatever its size, a system must be developed that allows for thorough initial evaluation of patients, formation of rational goals with the patient, adequate time for patient education and training, ongoing re-enforcement to consolidate and maintain gains, and an appropriate means of intervention when the patient experiences an exacerbation of his disease. It should also be recognized that in many areas of the country, there are too few patients and scarce medical resources to mount an intensive pulmonary rehabilitation program. In such instances, referral can be made to larger medical centers. More importantly, the individual practitioner can successfully incorporate many of the elements of pulmonary rehabilitation into his practice by taking the time and effort necessary to ascertain how illness affects the daily lives of the patient with COPD and then addressing patient concerns in an ongoing, comprehensive manner.

A quantitative evaluation of the AVITEWRITE model of handwriting learning.

Much sensory-motor behavior develops through imitation, as during the learning of handwriting by children. Such complex sequential acts are broken down into distinct motor control synergies, or muscle groups, whose activities overlap in time to generate continuous, curved movements that obey an inverse relation between curvature and speed. The adaptive vector integration to endpoint handwriting (AVITEWRITE) model of Grossberg and Paine (2000) [A neural model of corticocerebellar interactions during attentive imitation and predictive learning of sequential handwriting movements. Neural Networks, 13, 999-1046] addressed how such complex movements may be learned through attentive imitation. The model suggested how parietal and motor cortical mechanisms, such as difference vector encoding, interact with adaptively-timed, predictive cerebellar learning during movement imitation and predictive performance. Key psychophysical and neural data about learning to make curved movements were simulated, including a decrease in writing time as learning progresses; generation of unimodal, bell-shaped velocity profiles for each movement synergy; size scaling with isochrony, and speed scaling with preservation of the letter shape and the shapes of the velocity profiles; an inverse relation between curvature and tangential velocity; and a two-thirds power law relation between angular velocity and curvature. However, the model learned from letter trajectories of only one subject, and only qualitative kinematic comparisons were made with previously published human data. The present work describes a quantitative test of AVITEWRITE through direct comparison of a corpus of human handwriting data with the model's performance when it learns by tracing the human trajectories. The results show that model performance was variable across the subjects, with an average correlation between the model and human data of 0.89+/-0.10. The present data from simulations using the AVITEWRITE model highlight some of its strengths while focusing attention on areas, such as novel shape learning in children, where all models of handwriting and the learning of other complex sensory-motor skills would benefit from further research.

The role of the scapula.

The scapular musculature is often neglected in designing a rehabilitation protocol for the shoulder. Weakness of the scapular stabilizers and resultant altered biomechanics could result in: 1) abnormal stresses to the anterior capsular structures of the shoulder, 2) increased possibility of rotator cuff compression, and 3) decreased performance. This article presents known facts about the biomechanics of the scapula and surrounding muscles and suggests methods for evaluation of scapular muscle weakness. Exercise techniques to maximally strengthen the scapular musculature are also described. As our ability to document strength of these muscles improves, we will be able to determine the effect of scapular strengthening on improving symptoms related to impingement and instability. Scapular strengthening exercises are usually nonstressful to the rotator cuff and are easily implemented into a rehabilitation program for the shoulder.

Simultaneous high tibial osteotomy and ACL reconstruction for combined genu varum and symptomatic ACL tear.

This article reviews the subjective, objective, functional, and radiographic results of five patients with symptomatic anterior cruciate instability, genu varum, and varus rotational instability treated by sequential high tibial osteotomy and anterior cruciate ligament reconstruction at one operative procedure. The average patient age was 27 years (range: 21 to 35), and the average follow up was 2.5 years (range: 2 to 3). All patients had symptomatic instability with anterior tibia subluxation, which was documented by KT-1000 testing. All patients also had a varus alignment clinically and radiographically with medial compartment pain. Postoperatively, the medial compartment pain was improved, and instability episodes were eliminated. Side to side differences (KT-1000--manual maximum) were reduced to 3.1 mm. There were no complications. The instability episodes were eliminated, and functional levels were improved in all patients. We concluded that, for this select group of patients, simultaneous extremity realignment and ligament stabilization will effectively manage both conditions without compromising the results of either procedure.

Comparison of anterior laxity measurements in anterior cruciate deficient knees with two instrumented testing devices.

We measured anterior tibial displacements in 21 anterior cruciate ligament deficient patients using two instrumented testing devices, the KT-1000 and the KSS. A comparison of values obtained from testing was done using statistical analysis. The two tests common to both devices were the 20 lb pull and the manual maximum. The involved normal (I-N) values showed that there was no significant difference between the two devices for both the manual maximum and the 20 lb force level. There was also no significant difference between devices for the manual maximum absolute values. The significant difference between the absolute values for the 20 lb force level is probably due to the different testing techniques for both devices. When testing with the KSS, the patella remains free; testing with the KT-1000 requires that the examiner maintain pressure to hold the patella down. The manual maximum absolute values showed no significant difference because the testing techniques for both devices were identical. Comparable data for both devices are the I-N values for the 20 lb and manual maximum values.