Effect of the beta-adrenoceptor agonist clenbuterol and phytohaemagglutinin on growth, protein synthesis and polyamine metabolism of tissues of the rat.

1. The kidney bean lectin, phytohaemagglutinin (PHA), induced a marked atrophy of skeletal muscle which was evident from the changes in tissue composition (protein, RNA, DNA and polyamine content) and from the reduction in weight and protein synthesis of hind leg muscles of rats fed on kidney bean-diets for four days. The beta-adrenoceptor agonist, clenbuterol, induced skeletal muscle hypertrophy by transiently stimulating protein synthesis. As a consequence, the muscle loss caused by a short exposure to PHA was, in part, ameliorated by clenbuterol treatment. 2. Cardiac muscle was affected to a lesser extent than skeletal muscle by both clenbuterol and the lectin. However, there was evidence that protein synthesis in heart was reduced by PHA. 3. PHA had opposite effects on the gut, the lectin-induced hyperplasia of the jejunum was accompanied by a large increase in protein synthesis. Clenbuterol alone had no effect on the jejunum whereas a combination of PHA and clenbuterol appeared to exacerbate the effect of the lectin on gut. 4. Both the lectin-induced gut growth and the hypertrophy of skeletal muscle caused by clenbuterol were preceded by the accumulation of polyamines in the respective tissues. Of particular note was the observation that a significant increase in the proportion of the intraperitoneally injected 14C-labelled spermidine or putrescine taken up by the growing tissues could be detected by the second day. Therefore, the measurement of uptake of labelled polyamines may be used as a sensitive indicator of early alterations in tissue metabolism.     

Benefits and limitations of burn wound excision

This review is intended to provide a balanced view of the role of surgical burn wound excision and closure within the larger context of the total care and rehabilitation of patients with burn injury. The historical background leading to present practice is outlined. The salient technical and logistical problems associated with the performance of wound excision are discussed, with emphasis on the necessity for expeditiously completing these procedures which are associated with major blood loss. A realistic analysis of the results of excisional therapy in patients with burns of varying severity is presented. Benefits attributable to the surgical phase of therapy become progressively more difficult to identify as the size of deep burns increases beyond 20% of total body surface area.

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Resumen La presente revisión propone proveer una visión equilibrada del papel de la resección tangencial quirúrgica de la quemadura y su cierre en el contexto más amplio del cuidado total y la rehabilitación de pacientes con lesiones térmicas. Se hace un recuento de los antecedentes históricos y se discuten los más prominentes problemas técnicos y logísticos relacionados con la resección tangencial de la quemadura con énfasis en la necesidad de implementar en forma expedita estos procedimientos, los cuales se asocian con pérdidas mayores de sangre. Se presenta el análisis realista de los resultados de la resección tangencial en pacientes con quemaduras de gravedad variable. Los beneficios atribuibles a la fase quirúrgica de la terapia se hacen progresivamente más difíciles de identificar en cuanto la extensión y profundidad sobrepasan el 20% de la superficie corporal.

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Résumé Cette article fait le point sur les avantages et inconvénients respectifs de l'excision et la suture dans le cadre du traitement et la rééducation des grands brûlés. L'historique de cette technique est résumée. Les principaux problèmes de technique et de logistique de l'excision des brûlures sont discutés, en soulignant la nécessité d'assurer un geste rapide enfin de réduire les pertes sanguines. Une analyse réaliste des résultats de la technique excisionnelle des brûlures de sévérité variable est présentée. Les bénéfices directement en rapport avec la chirurgie deviennent plus difficiles à apprécier lorsque la surface brûlée dépasse 20 % de la surface corporéelle.

     

Comparison between continuous and intermittent infusion regimens of cimetidine in ulcer patients

The relative effectiveness of intermittent infusions and primed continuous infusions of cimetidine in the maintenance of intragastric pH greater than or equal to 4.0 was evaluated in a double-blind crossover trial in 26 patients who had active or healed gastroduodenal ulcers. During the intermittent phase, each patient received 300 mg cimetidine intravenously every 6 hours. During the continuous infusion phase, each patient was given a continuous infusion of 37.5 mg cimetidine per hour, preceded by a priming dose of 300 mg cimetidine that was given for 15 minutes. Intragastric pH was monitored continuously. During the last 12 hours of the study, the continuous infusion regimen provided 20% more time in which the pH was more [corrected] than 4.0 with 25% less medication than did the intermittent infusion regimen.     

Movement disorders and psychological tests of frontal lobe function in schizophrenic patients.

Neuropsychological tests of frontal lobe functions were undertaken in 46 chronic schizophrenic patients who were also rated for movement disorders. Tardive dyskinesia was found to have significant associations with most of these psychological tests. The possible mechanisms are discussed within the context of known neostriatal psychological functions.     

Guided tissue regeneration--why, when and how?

Chronic periodontitis results in the destruction of the collagen fibre attachment to cementum, apical migration of the epithelial attachment, contamination of the exposed root surface by plaque and loss of alveolar bone. Regeneration can be defined as the restitution of lost tissues to a state which existed before destruction. As such, it is an ultimate and ideal goal and in most circumstances is currently beyond our capabilities. However, research in periodontology over the last 10 years or so has made considerable advances and is perhaps unique in proposing a new and fundamental treatment modality--guided tissue regeneration.