Aryl acylamidase from Rhodococcus erythropolis NCIB 12273.

A Rhodococcus erythropolis strain was isolated from soil on the basis of its ability to use acetaminophen as the sole source of both carbon and energy for growth. When grown in a complex medium containing an anilide inducer compound, the bacterium exhibited aryl acylamidase (EC 3.5.1.13) activity. This activity was not subject to carbon or nitrogen repression by the growth medium constituents as the enzyme was present throughout the exponential growth phase. The anilide was converted to the corresponding aniline, which was not further degraded. The enzyme was partially purified by a variety of methods including a batch ion exchange procedure, column ion exchange chromatography and hydrophobic interaction chromatography. The enzyme had a maximum activity at around pH 8.0 and had a Km for acetaminophen of 0.11 mM. Electrochemical assays of aryl acylamidase activity are described. The enzyme is suitable for use as a reagent in the clinical diagnostic measurement of acetaminophen.

Results of L4-L5 disc excision alone versus disc excision and fusion.

We evaluated the results of 85 patients having L4-L5 disc excision (52 having disc excision alone, and 33 having disc excision and fusion) using the Smiley-Webster scale at an average follow-up of 7.3 years. Both groups (fusion and nonfusion) were comparable except that the nonfusion group had a significantly higher percentage of patients with a history of chronic back pain and degenerative changes on their initial radiographs. The fusion group had significantly better results compared with the nonfusion group (85% satisfactory results versus 39% satisfactory results). The most common cause of unsatisfactory results in the fusion group was pseudarthrosis (two) while progressive degenerative disc disease (18) and recurrent disc prolapse (eight) were the most common cause of unsatisfactory results in the nonfusion group. The overall reoperation rate was 9.4% (13.5% in the nonfusion group, and 3% in the fusion group.

Acute hematogenous osteomyelitis in children.

We reviewed the cases of 60 children with acute osteomyelitis with an average follow-up of 34 months. All patients were treated initially with high-dose intravenous (i.v.) antibiotics. Eight patients did not respond to this treatment within 48 h and had surgical drainage. The remaining 52 patients were divided into two subgroups: (a) 35 patients received i.v. antibiotics for an average of 21 days; (b) 17 patients received i.v. antibiotics for an average of 8 days followed by 4 weeks of oral therapy with monitoring of serum bactericidal levels. The incidence of chronic infection (12% for the operatively treated group and 4% for the nonoperatively treated group) depended more on the time interval between the presentation of symptoms and the onset of treatment than it did on the route of antibiotic administration.

Lumbar disc herniation in the elderly.

Thirty-two patients older than 60 years underwent surgical treatment for lumbar disc herniation over a 10-year period. Other causes of low-back pain and sciatica were investigated, and bony nerve root entrapment syndromes were not included. Sciatica was a predominant symptom and was present in all patients, with 81% showing positive nerve root tension signs. Motor deficit was found in more than half of the cases. A sequestrated disc was present in 50%. The follow-up ranged from 1 to 10 years with an average of 50 months. Eighty-seven percent of the patients had excellent or good results. There were no poor results and no one required reoperation. Lumbar disc herniation in the elderly is not a common problem, but surgery yields a high rate of satisfactory results if a proper investigation and correct diagnosis is obtained.

Treatment of unstable fractures of the distal radius by external fixation.

The Roger Anderson external fixator was used in the treatment of unstable fractures of the distal radius in 52 patients, and the results evaluated after a follow-up averaging 58 months. The indications for its use were failure to maintain adequate closed reduction using plaster, and instability of the fracture as determined by the initial radiographs. Our radiological criteria for instability included dorsal angulation of more than 20 degrees, fractures involving the joint, radial shortening of more than 10 mm, and severe dorsal comminution. Using the Lucas modification of the Sarmiento demerit point-rating system, we found that 46 patients (89%) had good or excellent results and six (11%) were classified as fair. There were no poor results. Seven patients (14%) developed complications. None of these affected the long-term results except in one elderly woman where the pins loosened and had to be removed.