Properties and partial purification of choline acetyltransferase from the nematode Caenorhabditis elegans.

We have stabilized and studied choline acetyltransferase from the nematode Caenorhabditis elegans. The enzyme is soluble, and two discrete forms were resolved by gel filtration. The larger of these two forms (MW approximately 154,000) was somewhat unstable and in the presence of 0.

Arthroscopic management of degenerative meniscus tears in patients with degenerative arthritis.

Frequently, meniscal pathology accompanies degenerative changes affecting the articular surface of the knee. The attritional changes in the meniscus lead to fragmentation of the meniscus and a variety of tears, usually of the posterior horn of the medial meniscus. A prospective study of the results of arthroscopic partial meniscectomy in the presence of at least Outerbridge Grade III chondromalacia of the accompanying joint surface was performed between 1980 and 1984.

Management of the infected total joint arthroplasty.

Infection is the most severe complication of total joint arthroplasty. Prompt recognition and correct management, as well as prophylaxis against infection, are essential to minimize morbidity and maximize function. In this article, the etiology and diagnosis of prosthetic infection and the management of infected total arthroplasties of the hip, knee, ankle, shoulder, elbow, and wrist are discussed.

The role of arthroscopy in the management of knee injuries in the athlete.

The athlete who has an acute knee injury requires early diagnosis and treatment, an accurate estimate of the extent of the injury and the time required for rehabilitation, and an ultimate prognosis for function. Arthroscopic evaluation is extremely useful in these persons because it allows an accurate early diagnosis of injuries to the menisci, cruciate ligaments, articular cartilage, joint capsule, and synovium. Early diagnosis allows selection of the treatment modalities that will permit the most rapid return of the athlete to sports activities in the minimal amount of time.

Choline acetyltransferase-deficient mutants of the nematode Caenorhabditis elegans.

We have identified five independent allelic mutations, defining the gene cha-1, that result in decreased choline acetyltransferase (ChAT) activity in Caenorhabditis elegans. Four of the mutant alleles, when homozygous, lead to ChAT reductions of greater than 98%, as well as recessive phenotypes of uncoordinated behavior, small size, slow growth and resistance to cholinesterase inhibitors. Animals homozygous for the fifth allele retain approximately 10% of the wild-type enzyme level; purified enzyme from this mutant has altered Km values for both choline and acetyl-CoA and is more thermolabile than the wild-type enzyme.

Comparison of Charnley and T-28 total hip arthroplasty.

A retrospective review of a matched series of 40 Charnley and 40 T-28 total hip arthroplasties was performed. The mean follow-up period after surgery was 5 1/2 years. The clinical status and detailed radiographic appearance were carefully evaluated prior to operation, two months after operation, and at the final follow-up examination.

Evaluation and management of unicompartmental osteoarthritis: role of arthroscopy in upper tibial osteotomy.

The evaluation of the patient with unicompartmental osteoarthritis of the knee and the appropriate management remain controversial. Although arthroscopy has not been shown to improve the accuracy of patient selection, it is useful in the management of associated intraarticular lesions and can be used for an intraarticular debridement procedure. Only long-term results of a prospective study will define if additional benefits over osteotomy alone are obtained by the addition of an intraarticular debridement.

Reimplantation for the salvage of an infected total knee arthroplasty.

We retrospectively reviewed the results in fourteen patients in whom salvage of an acutely infected total knee arthroplasty was attempted between 1970 and 1981 by the implantation of a new prosthesis within two weeks of removal of the infected one. Salvage was successful in six of the seven patients with a low-virulence infection but in only two of the seven patients with a high-virulence infection. Of the eight patients for whom the result was a functioning prosthesis, two had significant restriction of motion and one had moderate pain.

Musculoskeletal infection with nongonococcal neisseria species not associated with meningitis.

Five patients with type III musculoskeletal infection from nongonococcal Neisseria species were examined during a 13-month period. The initial clinical diagnosis was incorrect in all cases. Synovial fluid analysis and Gram's stain were not helpful, and the correct diagnosis was made only after culture reports were available.

Revision total knee arthroplasty.

The most frequent reasons for revision of total knee arthroplasty are loosening, instability, and abnormal axial alignment. Failure to obtain appropriate component orientation, axial alignment, and soft tissue balance predisposes the implants to loosening and failure. The use of minimally constrained prostheses and careful attention to the technique are essential.

Subendothelial deposition of von Willebrand's factor requires the presence of endothelial cells.

The presence of FVIII/VWF in human aortic subendothelium has been previously established. The present study was undertaken to determine the origin of this FVIII/VWF. Indirect immunofluorescence microscopy was employed to detect FVIII/VWF in rabbit aortas, after passage of a balloon catheter.

Talonavicular arthrodesis for isolated arthrosis: 9.5-year results and gait analysis.

Eleven patients who were treated for talonavicular arthrosis with a talonavicular arthrodesis between 1961 and 1979 at the Mayo Clinic have been reviewed. Follow-up from surgery ranged from 2.5 to 21 years with a mean of 9.

Electron microscopic localization of factor-VIII-related antigen in adult human blood vessels.

We have localized factor-VIII-related antigen, using immunofluorescence and electron microscopy, in adult human blood vessels. In addition to its presence in endothelial cells, the antigen was localized within subendothelium and the layers of elastic lamina closest to the lumen. Also, we provide the first morphological evidence that factor-VIII-related antigen is associated with collagen fibrils within the vessel wall.

Capitate fractures: a long-term follow-up.

Capitate fractures are serious carpal injuries that sould be treated as aggressively as scaphoid fractures, with anatomic reduction obtained by open techniques if necessary and by immobilization until the fracture has united. Thus treated, even a capitate proximal pole, free of soft tissue attachments will heal. Anatomic reduction is required for restoration of carpal kinematics.

Revision after total knee arthroplasty.

Revision of a total knee arthroplasty is most frequently required because of prosthetic loosening, instability, and failure to restore proper axial alignment. The instability and improper axial alignment may result in abnormal stresses that predispose to component loosening, component failure, and stress fracture of the tibia. Therefore, it is essential to obtain correct axial alignment and soft tissue balance at the time of the initial arthroplasty.

Plasma accumulation of metabolism of orally administered single dose L-5-hydroxytryptophan in man.

Single oral doses of L-5-hydroxytryptophan (5-HTP) were administered in combination with L-aromatic amino acid decarboxylase inhibitors. The time courses of plasma concentrations of 5-HTP, 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) and the concentrations of 5-HT in blood platelets were measured. Carbidopa enhanced the rise in plasma concentrations of 5-HTP 5-15 fold and counteracted the increase in plasma 5-HIAA levels induced by 5-HTP alone.

The use of technetium-99m sulfur colloid as a marker for experimental venous thrombosis: concise communication.

The binding of technetium-99m sulfur colloid to in vivo thrombi was studied in a rat model of deep vein thrombosis. After thrombosis was induced by mechanical traumatization of a right femoral vein segment, technetium-99m sulfur colloid was injected into the peripheral veins of different experimental groups at intervals of 30 min and 1-7 days. Ratios of mean activity in traumatized right femoral vein segment to activity in control segments of left femoral vein (R/L ratios) ranged form 2.

Total shoulder arthroplasty for the arthropathy of hemochromatosis: a case report.

Hemochromatosis presentingwithonly the manifestations of arthropathy is unusual. Although severe joint involvement by hemochromatosis, leading to total joint arthroplasty in the lower extremities, has been previously reported, involvement of the shoulder has been noted infrequently. We describe a patient with severe arthropathy of hemochromatosis requiring total shoulder arthroplasty and review the orthopedic implications of hemochromatosis.

A comparison of the effect of open intramedullary nailing and compression-plate fixation on fracture-site blood flow and fracture union.

Unlabelled: We compared the effects of compression-plating and open intramedullary nailing after reaming on the vascular supply to a standard fracture site, on the rate of fracture union, and on the biomechanical quality of bone after union, and on the biomechanical quality of bone after union in dogs. The proper location of a compression plate in relation to the periosteum also was investigated. Bone blood flow reached higher levels and remained elevated longer in fractures that were fixed with a rod than in those fixed with a plate.