Altered specificity of a AAA+ protease.

ClpXP, an ATP-dependent protease, degrades hundreds of different intracellular proteins. ClpX chooses substrates by binding peptide tags, typically displayed at the N or C terminus of the protein to be degraded. Here, we identify a ClpX mutant that displays a 300-fold change in substrate specificity, resulting in decreased degradation of ssrA-tagged substrates but improved degradation of proteins with other classes of degradation signals.

Patient and physician-assessed shoulder function after arthroplasty.

Background: We found no information in the literature regarding the relationship between patient and physician-derived outcome assessments with a shoulder questionnaire. In this study, we examined a group of patients who were assessed with patient and physician-administered questionnaires following shoulder arthroplasty.

Methods: From August 2003 to February 2004, sixty-seven consecutive patients who had been followed for a minimum of six months after shoulder arthroplasty were evaluated with a self-administered and an identical physician-directed shoulder questionnaire that assessed clinical and functional outcomes at the time of routine follow-up.

Motor nerve palsy following primary total hip arthroplasty.

Background: Nerve palsy is a potentially devastating complication following total hip arthroplasty. The purpose of this study was to retrospectively identify risk factors for, and the prognosis associated with, a motor nerve palsy following primary total hip arthroplasty.

Methods: Between 1970 and 2000, 27,004 primary total hip arthroplasties were performed at our institution.

Manipulation for frozen shoulder: long-term results.

Although much has been published regarding shoulder manipulation under anesthesia for the treatment of frozen shoulder, there are no reported long-term results. In 25 patients (26 shoulders) in whom nonoperative treatment for idiopathic frozen shoulder had failed, we performed manipulation under anesthesia. All had had physical therapy for a mean of 6.

Autogenous femoral head bone grafts for acetabular deficiency in total-hip arthroplasty for developmental dysplasia of the hip: long-term effect on pelvic bone stock.

Twenty-eight primary total-hip arthroplasties in 23 patients performed with autogenous femoral head bone graft augmentation for developmental hip dysplasia were retrospectively reviewed at 8 to 15 years. Five sockets were revised for different reasons. At revisions, 3 grafts were healed, the other 2 had substantial resorption.

Cytoplasmic degradation of ssrA-tagged proteins.

Degradation of ssrA-tagged proteins is a central feature of protein-quality control in all bacteria. In Escherichia coli, the ATP-dependent ClpXP and ClpAP proteases are thought to participate in this process, but their relative contributions to degradation of ssrA-tagged proteins in vivo have been uncertain because two adaptor proteins, ClpS and SspB, can modulate proteolysis of these substrates. Here, intracellular levels of these protease components and adaptors were determined during exponential growth and as cells entered early stationary phase.

Synthesis of 9-acridinyl sulfur derivatives: sulfides, sulfoxides and sulfones. Comparison of their activity on tumour cells.

The synthesis of several acridine thioethers is described. These compounds were oxidized to give new sulfoxides and sulfones. Among 23 compounds prepared, 19 were tested in vitro against the human cancer cell lines panel of NCI screening.

A kinesin switch I arginine to lysine mutation rescues microtubule function.

Switch I and II are key active site structural elements of kinesins, myosins, and G-proteins. Our analysis of a switch I mutant (R210A) in Drosophila melanogaster kinesin showed a reduction in microtubule affinity, a loss in cooperativity between the motor domains, and an ATP hydrolysis defect leading to aberrant detachment from the microtubule. To investigate the conserved arginine in switch I further, a lysine substitution mutant was generated.

Acute compartment syndrome of the leg following diagnostic electromyography.

Acute compartment syndrome of the lower extremity is typically associated with some form of trauma, either fracture or blunt injury. Accurate diagnosis and urgent treatment of this condition is required for preservation of the viability of the limb. We report the case of a 73-year-old man who developed an acute compartment syndrome of the leg after diagnostic electromyography.

The role of ATP hydrolysis for kinesin processivity.

Conventional kinesin is a highly processive, plus-end-directed microtubule-based motor that drives membranous organelles toward the synapse in neurons. Although recent structural, biochemical, and mechanical measurements are beginning to converge into a common view of how kinesin converts the energy from ATP turnover into motion, it remains difficult to dissect experimentally the intermolecular domain cooperativity required for kinesin processivity. We report here our pre-steady-state kinetic analysis of a kinesin switch I mutant at Arg(210) (NXXSSRSH, residues 205-212 in Drosophila kinesin).