Dose-response relationship of atracurium besylate in the halothane-anaesthetised pig

The dose response relationship for the intermediate-acting non-depolarising muscle relaxant, atracurium besylate in the pig was determined using evoked electromyography. An incremental dose technique was used in seven Large White/Landrace crossbred pigs anaesthetised with nitrous oxide and halothane. ED50 and ED95 were 510 +/- 87 micrograms kg-1 and 1150 +/- 270 micrograms kg-1, respectively. Although these values may represent an overestimate, they provide a reasonable guideline for the use of atracurium by veterinary anaesthetists.     

Purification of choline acetyltransferase from Drosophila melanogaster

Choline acetyltransferase (EC 2.3.1.6) from Drosophila melanogaster (Canton S, wild type) was purified 12,500-fold to a final specific activity of 500 mumol min-1 mg protein-1. The purification used homogenized fly heads and consisted of polyethylene glycol precipitation, DEAE-Bio-Gel A chromatography, Octyl-Sepharose chromatography, and affinity chromatography using solid phase Green A-agarose. The molecular weight of the native enzyme, as determined by molecular exclusion chromatography, was approximately 67,000 daltons. The final enzyme preparation showed two major protein bands at 67,000 and 54,000 daltons on polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS). After molecular exclusion chromatography, both SDS gel bands were present in the single symmetrical peak that contained the enzyme activity. Two-dimensional tryptic peptide maps prepared from the individual SDS gel bands indicated that they have very similar primary structures. Both SDS gel bands were precipitated by two different monoclonal antibodies derived against Drosophila choline acetyltransferase activity. The structural and immunological relatedness of the two SDS gel bands indicates that the enzyme is essentially homogeneous and that, in the native state, it may consist of more than one polypeptide chain.     

Diagnostic and prognostic significance of arterial pressure in late toxemia in pregnancy

Manganese content in blood sera of healthy subjects fluctuates within the interval of 0.008 mkg/ml to 0.032 mkg/ml--hence the requirement of especially sensitive methods for manganese determination. Atom-absorption methods are very suitable in this case because a minimal preparation of the sample is required. The authors intended the elaboration of a direct atom-absorption method, tracing manganese content in blood and urine. Manganese content in blood serum is rather close to the detectable minimum for manganese in its determination with the applied two-beam atom-absorption spectro-photometer. In the present work, the results from the prophylactic examinations of workers are presented, being in occupational contact with manganese (occupational-pathological screening) as well as from a control group of practically healthy volunteers--blood donors. Values in the interval 0.1017--0.032 mkg/ml with a standard deviation of 0.003 mkg/ml were obtained for the control group. The group of the workers examined, being in contact with manganese aerosols has an average value of 0.034 mkg/ml. Eighty eight per cent of all examined are in the interval from 0.01--0.05 mkg/ml. The rest 12 per cent work in shops where manganese elimination is higher. The method proposed is productive (up to 100 manganese determinations in diluted 1:1 serum per hour).     

Sectional versus full model wind tunnel testing of bridge road decks

This paper reviews fundamental aspects of modelling procedures and bridge road deck behaviour with a view to appraising the advantages and disadvantages of the sectional, taut-strip and full model approaches. It is concluded that in the present state of the art, there is a time and place for each technique; which investigative procedure or combination of procedures is used will depend on a variety of considerations—the size of the bridge, the road deck configuration and the lead time available.     

Effect of gentamicin on early mortality and later performance of broiler and Leghorn chickens

Field and floor-pen trials demonstrated that subcutaneous injection of 0.2 mg gentamicin at one day old reduced bacteria-caused deaths in White Leghorn and broiler-type chicks. Growth, feed efficiency, and condemnation data from broiler trials suggested an advantage for treated chickens over unmedicated controls. Ninety-nine percent of clinical isolates were susceptible to gentamicin (10 mug) when tested by the modified Kirby-Bauer method. In vitro susceptibilities of these isolates to neomycin, nitrofurazone, chloramphenicol, and kanamycin varied from 90 to 94%. About half of the isolates were susceptible to dihydrostreptomycin or tetracycline in vitro, while less than 10% were susceptible to penicillin or clindamycin. In vitro tests to determine the lowest concentration of antibiotics required to inhibit the growth of 31 bacterial isolates demonstrated that less gentamicin is required than neomycin, spectinomycin, or oxytetracycline.     

Milieu therapy: toward a definition for reimbursement

The authors identify certain essential elements and processes within the milieu therapy approach that could provide the basis for reimbursement of this treatment modality under insurance. They also examine a philosophical framework, various guidelines, and a mechanism for accountability in the use of this form of treatment.     

Peripheral arterial injuries: a reassessment

Ninety-four patients with peripheral arterial injuries were subjected to acute repair, negative exploration, or late repair of the complications of the arterial injury (false aneurysm, A-V fistula, and/or limb ischemia). The causes of failure after acute injury include extensive local soft tissue and bony damage, severe concomitant head, chest or abdominal wounding, stubborn reliance on negative arteriograms in patients with probable arterial injury, failure to repair simultaneous venous injuries, or harvesting of a vein graft from a severely damaged extremity. There is a positive correlation between non-operative expectant treatment and the incidence of late vascular complications requiring late arterial repair. Delayed complications of arterial injuries occurred most frequently in wounds below the elbow and knee.