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.     

An observer blind trial of co-amoxiclav versus cefuroxime plus metronidazole in the prevention of postoperative wound infection after general surgery

A consecutive series of 509 patients undergoing abdominal surgery were entered into a randomized, observer and patient blind, controlled, prospective, study to evaluate the efficiency of co-amoxiclav (‘Augmentin’, SmithKline Beecham, UK) compared with cefuroxime (‘Zinacef’ Glaxo, UK) plus metronidazole (Flagyl, M&B, UK) for the prevention of postoperative wound infections. One or three doses of antibiotics were given depending on the type of surgery and operative factors. Co-amoxiclav was given to 230 patients with a total wound infection rate of 5·6% and cefuroxime plus metronidazole were given to 225 patients with a total wound infection rate of 3%. The difference between infection rates was not significant. Both groups were comparable in terms of demographic details, type and duration of surgery, risk factors associated with surgical procedures and postoperative management. Although not statistically significant, a difference in the wound infection rate for those patients undergoing colorectal surgery was seen: for the co-amoxiclav group and for the cefuroxime/ metronidazole group. The estimated cost to our hospital (October 1993) of one dose of co-amoxiclav was less that half the cost of cefuroxime and metronidazole. This study demonstrates that co-amoxiclav is an effective prophylactic antibiotic for abdominal surgery.     

Cognitive rehabilitation in the elderly: overview and future directions.

This study provides an overview of the papers emanating from the experimental trial that evaluated a new cognitive rehabilitation program in older adults who were experiencing normal cognitive decline. The main features of the design are summarized, along with evidence that the training produced long-lasting improvement in memory performance, goal management, and psychosocial status. The benefits were attributed to several factors, including the program's emphasis on techniques that promoted efficient strategic processing. Limitations of the program and directions for future research are discussed.     

Extended duration of herpes simplex virus DNA in genital lesions detected by the polymerase chain reaction.

To evaluate the utility of the polymerase chain reaction (PCR) for documenting herpes simplex virus (HSV) in persons with reactivated genital lesions viral isolation was compared with a recently developed PCR method. Three women experiencing four episodes of recurrent genital herpes were followed for 10 days per episode with daily examination and duplicate swabs of the lesions, one for HSV culture and one for PCR. HSV type 2 was cultured from three of four episodes and the mean duration of viral isolation from recurrent genital lesions was 2.6 days. PCR detected HSV DNA from lesion swabs during all four episodes, and HSV DNA was positive for an average of 6.8 days. HSV DNA was demonstrated in ulcerative lesions on 15 of 17 days versus 3 of 17 days by viral isolation (P less than .01). HSV PCR became negative when the lesions reepithelialized. These data suggest that PCR is a more sensitive measure of HSV infection than routine viral culture and that PCR detects the presence of HSV at times when culture is negative.     

The distal radioulnar joint. Anatomy, biomechanics, and triangular fibrocartilage complex abnormalities

The distal radioulnar joint plays an intricate part in the function of the wrist and thus in the function of the entire upper extremity. The radius and hand move in relation to and function about the distal ulna. Significant loads are transmitted to the forearm unit through the distal ulna via the triangular fibrocartilage complex. The anatomic relationships between the distal radius and ulna and ulnar carpus are precise, and even minor modification in these relationships leads to significant load changes and resultant pain syndromes. Evaluation of a patient with ulnar wrist pain is, at best, difficult. Despite a careful and thorough history and physical examination and the use of sophisticated ancillary diagnostic studies, some patients with distal radioulnar joint and ulnar carpal complex problems remain diagnostic and therapeutic mysteries. These patients are best followed; exploratory surgery is rarely satisfying to either the patient or the surgeon. Armed with an understanding of the normal anatomy and biomechanics, the examination of such a patient and subsequent treatment should become a challenge that is rewarding for both patient and treating physician.     

The anti-aggregating properties of vascular endothelium: interactions between prostacyclin and nitric oxide

1. The interactions between endothelium-derived nitric oxide (NO) and prostacyclin as inhibitors of platelet aggregation were examined. 2. Porcine aortic endothelial cells treated with indomethacin and stimulated with bradykinin (10-100 nM) released NO in quantities sufficient to account for the inhibition of platelet aggregation attributed to endothelium-derived relaxing factor (EDRF). 3. In the absence of indomethacin, stimulation of the cells with bradykinin (1-3 nM) released small amounts of prostacyclin and EDRF which synergistically inhibited platelet aggregation. 4. EDRF and authentic NO also caused disaggregation of platelets aggregated either with collagen or with U46619. 5. A reciprocal potentiation of both the anti- and the dis-aggregating activity was also observed between low concentrations of prostacyclin and authentic NO or EDRF released from endothelial cells. 6. It is likely that interactions between prostacyclin and NO released by the endothelium play a role in the homeostatic regulation of platelet-vessel wall interactions.