Loss of Soluble (Pro)renin Receptor Attenuates Angiotensin-II Induced Hypertension and Renal Injury.

[Figure: see text].

Genetic selection for modulators of the MAP kinase and beta-catenin growth-control pathways in mammalian cells.

Transdominant genetic selections can yield protein fragment and peptide modulators of specific biochemical pathways. In yeast, such screens have been highly successful in targeting the MAP (mitogen-activated protein) kinase growth-control pathway. We performed a similar type of selection aimed at recovery of modulators of the mammalian MAP kinase cascade. Two pathway activators were identified, fragments of the TrkB and Raf-1 kinases. In a second selection directed at the beta-catenin growth-control pathway, three different clones encoding cadherin fragments were recovered. In neither selection were peptide inhibitors observed. We conclude that some transdominant selections in mammalian cells can readily yield high-penetrance protein fragments, but may be less amenable to isolation of peptide inhibitors.

Intra-articular anterior cruciate ligament reconstruction using patellar tendon allograft in the skeletally immature patient.

PURPOSE: Tears of the anterior cruciate ligament (ACL) are becoming more prevalent in the skeletally immature patient. We report our results with intra-articular transphyseal ACL reconstruction in this patient population. TYPE OF STUDY: Retrospective analysis. METHODS: Ten skeletally immature athletes underwent transphyseal intra-articular ACL reconstruction using patellar tendon allograft. The patients ranged from 9 to 15 years of age. Clinical outcomes were measured using the Lysholm and International Knee Documentation Committee scoring systems, follow-up radiographs, clinical examination, and KT-1000 testing. RESULTS: Mean follow-up was 40 months. The average Lysholm score was 95, and 9 of 10 patients reported normal or nearly normal knee function. There was no clinical or objective evidence of instability, limb-length discrepancy, or early physeal arrest. Nine of 10 patients returned to their preinjury level of athletics. CONCLUSIONS: Skeletally immature athletes with symptomatic complete ACL tears who do not want to modify their athletic activity may benefit from intra-articular ACL reconstruction using patellar tendon allografts. Special attention to bone plug and interference screw placement will reduce the risk of early physeal arrest.

Arthroscopic posterior cruciate ligament repair.

PURPOSE: We present our technique of arthroscopic repair for femoral avulsion soft-tissue tears of the posterior cruciate ligament (PCL) and its results. TYPE OF STUDY: Case series, retrospective review. METHODS: We performed 13 arthroscopic repairs of the PCL and reviewed them retrospectively. Follow-up was available for 11 (85%) patients. Nonabsorbable monofilament sutures were placed through the loose fibers of the ligament and tied over a bone bridge. Patients were evaluated using magnetic resonance imaging, comparative stress views, and according to the scoring systems of Lysholm and Gillquist and the International Knee Documentation Committee (IKDC). RESULTS: Mean follow-up was 51.4 months. IKDC scores revealed 4 (36.4%) patients with normal knee function, and 7 (63.6%) with nearly normal function. Average Lysholm and Gillquist score was 95.4 (90 to 100). All athletes returned to the same or a higher level of competition. CONCLUSIONS: Arthroscopic repair of the PCL in patients with a femoral avulsion is effective in reducing postoperative instability and improving functional outcome.

Enhanced expression of exogenous genes from retroviruses using HIV2/Tat.

The capacity to produce large amounts of protein in mammalian cells is important in several contexts, including large-scale generation of biologically useful proteins, gene therapy, and transdominant genetics in cultured cells. For transdominant genetics, retroviral vectors are especially useful for delivery of expression libraries. However, even the potent CMV promoter is often unable to stimulate single-copy production of protein beyond the 1 microM level. We have adapted the HIV2/Tat expression system to retroviral vectors to boost expression above levels attainable with CMV promoters. We show that the system produces protein levels in four cell types tested which exceed levels attained by wild-type CMV or modified CMV promoters. In one cell line, the increase is 10-fold above CMV. Coupled with a stable expressed protein, levels of about 4 microM can be produced from presumptive single-copy retroviral transductants, and 30 microM from multicopy transductants.