Human selenium status and glutathione peroxidase activity in north-west England

Nutritional selenium deficiency disease, due to low soil selenium content, is well recognized in British livestock. The adequacy of the selenium status of 25 healthy human volunteers, 50 blood donors, 94 general medical patients and 106 allergy clinic patients was investigated in 1987/8 by measuring serum selenium concentration and platelet glutathione peroxidase activity. Mean serum selenium concentration for the entire study population was 92 micrograms/l. Significant linear correlations between serum selenium concentration and peroxidase activity indicate that a substantial proportion of both healthy volunteers and medical patients are of low selenium nutritional status. Twenty-five per cent of healthy volunteers and 50 per cent of medical patients had serum selenium values below those required for full expression of selenium-dependent enzyme activity. Deficiency of the antioxidant activities of selenium and selenium-dependent enzymes may be relevant to geographical differences in morbidity from a wide range of human disease states.     

Microbiological and pharmacokinetic studies of acyl demycinosyltylosin and related tylosin derivatives

A series of tylosins and acyl derivatives of 23-O-demycinosyltylosin (DMT) were initially tested for in vitro antibacterial activity and serum levels in squirrel monkeys (po) and mice (iv). Overall, the DMT compounds were more active in vitro than the tylosins. Two tetraacylated DMTs, Sch 37644 and Sch 38646, were selected from the initial studies for further evaluation and compared to erythromycin and A-56268 (6-O-methyl erythromycin). Sch 37644 and Sch 38646 were 2 to 8-fold less potent in vitro against Gram-positive bacteria than erythromycin and A-56268. In squirrel monkeys, Sch 37644 (AUC, 19.7 micrograms.hour ml) and A-56268 (21.6 micrograms.hour/ml) had similar serum levels following po administration of 20 mg/kg, while Sch 38646 (11.8 micrograms.hour/ml) and erythromycin (1.5 micrograms.hour/ml) had lower levels. In mice administered 200 mg/kg orally, Sch 37644 (AUC, 19.4 micrograms.hour/ml) and Sch 38646 (15.4 micrograms.hour/ml) had higher serum levels than erythromycin (5.7 micrograms.hour/ml). A-56268 was the most active po macrolide in mouse protection studies (PD50S) against Staphylococci and Streptococci, while Sch 37644 and Sch 38646 were similar to erythromycin.     

Uninformed Decisionmaking The Case of Surrogate Research Consent

A New York court recently struck down state Office of Mental Health regulations governing research involving subjects with impaired decisionmaking capacity. The court held that neither incapacitated adults nor minors could participate in any research protocol that contained a nontherapeutic element, irrespective of possible benefits to the subject or the importance of the knowledge to be gained. Although the decision rested on a technical point of law and dealt only with psychiatric research, the court's holding has significantly broader implications.     

Imaging of thoracic and lumbar spinal extradural arachnoid cysts: report of two cases

Extradural arachnoid cysts are uncommon expanding lesions in the spinal canal which may communicate with the subarachnoid space. Usually in the lower thoracic spine, they may cause symptoms by compressing the spinal cord or nerve roots. We report cases of thoracic and lumbar arachnoid cysts studied by cystography, myelography, CT and MRI. These techniques showed extradural cystic lesions containing cerebrospinal fluid, with variable communication with the subarachnoid space, causing anterior displacement and flattening of the spinal cord. Received: 3 November 1995 Accepted: 16 April 1996     

Fragment length polymorphisms among independent isolates of Epstein-Barr virus from immunocompromised and normal hosts

DNA restriction fragment length polymorphisms of Epstein-Barr virus (EBV) DNA were used as a molecular epidemiological tool to study multiple isolates of virus from the same and different individuals. We studied 35 EBV isolates: 19 from seven immunocompromised children and 16 from seven college students with mononucleosis. Analysis of the fragment length polymorphisms in this collection of isolates permitted several conclusions. Sites of polymorphism were most often encountered in regions with repetitive DNA. Epidemiologically unrelated patients harbored viruses that could be readily distinguished; by contrast, two infants and their mothers harbored similar viruses. Isolates from different sites in the same patient were similar. Variations between different clinical isolates of EBV mimic those found between different laboratory strains of the virus. Fragment length polymorphisms thus provide a useful marker for studying transmission and pathogenesis of EBV infections.     

Encrustation of intraprostatic stents--a comparative study.

Metallic stents have been used in the management of prostatic disease in patients unfit for surgery. A variety of stents have become available but the optimum design and metal of construction has not yet been defined. This study examined one of the potential complications of stent insertion by demonstrating that they are susceptible to encrustation. Using an in vitro model it compares the ability of the different materials used in their construction to resist this encrustation. Titanium appears less able to resist deposition than the other metals examined. The long-term complication of encrustation may inhibit the use of some of these stents.     

Normal intracortical excitability in developmental stuttering.

Persistent developmental stuttering (PDS) shares clinical features with task-specific dystonias. In these dystonias, intracortical inhibition is abnormally weak. We therefore sought to determine intracortical inhibition and intracortical facilitation in PDS. In 18 subjects with PDS since childhood (mean age, 39.4 [SD 13.0] years) and 18 speech-fluent controls (43.6 [14.3] years), we investigated resting and active motor thresholds as well as intracortical inhibition and facilitation of the optimal representation of the abductor digiti minimi of the dominant hand using transcranial magnetic stimulation. In PDS, the resting and active motor thresholds were increased, whereas intracortical inhibition and facilitation were normal. Normal intracortical excitability makes a pathophysiological analogy between focal dystonia and PDS less likely. The enhanced motor threshold suggests reduced motor cortical neuronal membrane excitability in PDS.     

Ileocutaneous fistula formation following laparoscopic polypropylene mesh hernia repair

A rare case of enterocutaneous fistula caused by chronic erosion of polypropylene mesh after laparoscopic repair of a recurrent inguinal hernia is described. Successful treatment was achieved by fistulectomy, total resection of the implanted mesh, and small-bowel segmental resection. The patient recovered well postoperatively, and at follow-up 18 months later, the herniorrhaphy has remained intact. This complication needs to be added to the differential diagnosis in patients who present inflammation, abscess formation, or cutaneous fistula following laparoscopic hernia repair. Received: 7 October 1996/Accepted: 14 October 1996