The influence of gastrointestinal agents on resorption and metabolism of cyclosporine after heart transplantation: experimental and clinical results

The clinical effectiveness of cyclosporine is limited by changes in resorption and metabolism of cyclosporine and by possible drug interactions. This study examined the influence of five gastrointestinal agents on duration and resorption of cyclosporine and dosage/level relations: cimetidine, famotidine, pirenzepine, aluminum hydroxide, and omeprazole. These gastrointestinal agents were studied in 64 rat experiments, in which the impact of each single drug and of drug combinations on cyclosporine resorption and metabolism was tested. A standardized dosage of cyclosporine was given orally, and the duration was calculated for the maximum whole blood level of cyclosporine to be achieved; the dosage/level quotient was calculated. Cimetidine, famotidine, pirenzepine, and combination treatment prolonged duration of cyclosporine resorption. Furthermore, cimetidine, famotidine, and omeprazole lowered the dosage/level quotient, thus leading to higher cyclosporine levels with the same dosage; pirenzepine increased the dosage/level quotient. For clinical comparison, 163 heart transplant patients who had received standard triple-drug immunosuppressive therapy were analyzed. The time interval until a therapeutic cyclosporine level was achieved and the dosage/level quotient were once again calculated. Similar to the results in the animal experiments, cimetidine and famotidine significantly delayed the resorption of cyclosporine; cimetidine, famotidine, and omeprazole lowered the cyclosporine dosage/level quotient, thus leading to higher cyclosporine levels with the same dosage. Aluminum hydroxide did not lead to any changes in the resorption or metabolism of cyclosporine. Most examined gastrointestinal agents, and particularly H2-blocking drugs, led to significant prolongation of cyclosporine resorption and cyclosporine level alterations. The initial prolongation of cyclosporine resorption was successfully avoided by intravenous administration of cyclosporine for the first 4 postoperative days in 40 consecutive patients.

Effect of dietary restriction on in vivo somatic mutation in mice

Dietary restriction is the one experimental variable which has been shown reproducibly to retard ageing. The effect of dietary restriction on in vivo mutation was studied in mice by feeding experimental mice 60% of the amount eaten by control mice and measuring mutations in lymphocytes at the hypoxanthine phosphoribosyl transferase locus at 4 weeks, 6 months and 12 months of age. Dietary restriction markedly decreased the age-associated accumulation of mutations observed in control mice, which suggests that somatic mutation is involved in the ageing process and that the majority of in vivo mutations result from dietary factors.

[Craniocerebral trauma and aseptic osteonecrosis. Steroid-induced sequelae after therapy of brain edema]

In this publication we present three cases of avascular osteonecrosis (AON) of the femoral head and the talus in adolescent and young adult patients following short-term, high-dose steroid therapy for cerebral trauma. All patients were proven to be free of other risk factors for AON. The latency period between the steroid therapy and the occurrence of AON ranged from 12 to 60 months; steroid therapy lasted for 12 to 16 days with a total dosage equivalent to 2370-7180 mg prednisolone. Our case reports are added to a review of the literature with 14 similar cases reported receiving short-term, high-dose steroid therapy; 2 of them were also after brain trauma. To the best of our knowledge, 1 of our cases shows the longest latency period ever described after such therapy, and all our cases had a shorter therapy time than reported by other authors who have mentioned brain trauma patients. Additionally, bilateral necrosis of the talus due to short-term, high-dose steroid therapy has also not previously been described. Whereas AON is quite common after long-term steroid therapy (e.g., for immunosuppression and rheumatic disorders), our cases prove that serious complications can occur even after a short period of emergency steroid therapy in cerebral trauma, a possibility that is generally unknown. The minimal dosage and the maximum time steroids can be applied to exclude the risk of AON has not yet been determined, although we do recognize that steroids are useful for the prevention of brain edema.(ABSTRACT TRUNCATED AT 250 WORDS)

[Wound secretions in standard orthopedic surgery interventions using a new kind of closed vacuum drainage. A report of experiences]

One year's experience with 400 closed Redyrob drainage systems in 267 male and female patients has yielded encouraging results, which led to the replacement of the drainage system formerly used in the orthopaedic university clinic in Marburg by the new system. This makes it possible to regulate the suction strength between 0 and 900 mbar and to couple two suction tubes with one container. Drainage without suction and changing of the containers, which may be necessary in the case of large wound surfaces, can be performed without opening the system, which would endanger both patients and clinic personnel. Additional containers were only needed in 2.3%, because of the better filling volume. Thus, the new drainage system also proved to be superior with respect to cost efficiency and disposal. The total amount of wound secretion never exceeded 1620 ml, depending on the type of surgery performed, and there were no cases of infection or bleeding complications. The suction was regulated in 74% of all systems, and after most of the operations for insertion of endoprostheses. The handling of the systems was classed by the staff on the ward as "very good" or "good" in 96% of all cases. These results are discussed in the light of important aspects of wound drainage already mentioned by other authors.

Vertebral body replacement with homologous femoral head transplants

From 1978 to 1989, we carried out 15 resections of single vertebral bodies, with homologous femoral head transplantation, for malignant and benign lesions of the spine. The advantages of this procedure are compared to fixation with bone cement, autologous bone grafts and other materials. The results are discussed.

Regulation of rat ileal water absorption by central alpha 2 adrenergic receptors

This study examined the role of central adrenergic receptors in the regulation of water absorption by the rat ileum. Clonidine, an alpha 2-adrenergic receptor agonist, increased water absorption in vivo following intracerebroventricular but not intravenous injection. Intracerebroventricular injection of prazosin, an alpha 1-adrenergic receptor antagonist, did not alter basal water absorption. Prazosin did not prevent the clonidine effect. In contrast, the alpha 2-adrenergic receptor antagonist, yohimbine, reduced basal absorption and prevented the intracerebroventricular clonidine effect. Treatment with reserpine reduced ileal norepinephrine content by 98%, reduced basal water absorption consistent with a loss of sympathetic outflow to the mucosa, but did not prevent the increase in water absorption due to intracerebroventricular clonidine. These results suggest that central alpha 2 receptors regulate water absorption by the rat ileum. The clonidine-induced increase in water absorption is not mediated by the sympathetic nerves innervating the intestine.

Testing medical disposables using the Limulus Amoebocyte Lysate (LAL) test

Plastic, single-use devices intended for the administration of drugs or for the removal or transfer of body fluids must be free of pyrogenic contaminants. Unfortunately, very little information is available regarding tests to detect such contaminants. For this reason, many manufacturers of medical disposables must rely on their own discretion when they devise methods for extracting these substances from their products. This article discusses the use and value of the Limulus Amoebocyte Lysate (LAL) test for estimating the concentration and extraction of bacterial endotoxins in disposable medical devices. When bioburden-control procedures are applied to products manufactured to GMP requirements, batch testing of products for pyrogenicity may not be essential.

[Puncture track metastasis after ultrasound-guided fine-needle puncture biopsy. A rare complication?]

Bilaterally enlarged adrenals were diagnosed by ultrasonography in a 57-year-old man with a potentially resectable adenocarcinoma of the lung. Ultrasound-guided fine-needle biopsy of the left adrenal revealed a metastasis, proven cytologically. Chemotherapy was tried but failed to influence tumour growth. Three months later a painful subcutaneous nodule was noted in the area of the previous needle puncture, which on removal proved to be a skin metastasis. The patient died later from the underlying tumour.

Automated percutaneous lumbar discectomy with and without chymopapain pretreatment versus non-automated discoscopy-monitored percutaneous lumbar discectomy. An experimental study in human cadaver spines

Percutaneous lumbar discectomy has gained growing interest during recent years as an alternative to open surgery for protrusions and non-sequestrated subligamentous intervertebral disc herniations. As a less invasive method it competes with chemonucleolysis. At least two modifications are known to date: automated percutaneous lumbar discectomy (APLD) with a 2-mm suction probe and non-automated, discoscopy-monitored percutaneous lumbar discectomy with a suction rongeur and a motor-driven shaver (NAPLD). In this study these two methods are compared for the amount of material extracted, dependence upon the degree of degeneration of the disc and intrinsic technical problems, using 20 human cadaver lumbar specimens for experimental testing. Total nucleotomy was not possible with either method. APLD yielded significantly less material and proved to be less effective in severely degenerated intervertebral discs than the NAPLD procedure, as preexisting gaps within the degenerated nucleus pulposus allowed the tissue to shift away from the tip of the 2-mm probe and facilitated displacement of the probe within the anulus fibrosus. By contrast, the rongeur, which first cuts the material to be removed and then carries it away by suction, was much more effective. Further data to support the advantages of non-automated percutaneous nucleotomy are discussed. Pretreatment of the disc with chymopapain did not result in a higher yield of nucleus material when combined with APLD.

[Valgisation tibial head alignment osteotomy--results of a comparative follow-up of Coventry interligament tibial head osteotomy and Wagner oblique osteotomy]

In the follow-up study presented the results of 33 high tibia-osteotomies (Coventry) are compared with 51 oblique lower tibia-osteotomies (Wagner). Both techniques guarantee a safe improvement of function, pain relief, and biomechanic situation of the arthrotic joint. The results are mainly independent of the grade of joint involvement and the age of the patient. The Coventry-osteotomy tends to accentuate femoropatellar arthrotic destruction, while the Wagner-osteotomy does so in 20% fewer cases. The functional improvements of the Wagner-osteotomy are more than 20% better, up to 5 years postoperatively, when compared with the high tibia-osteotomy. Indication, technical performance of the operation, and the postoperative care are discussed in the light of the results presented.

Therapeutic experience with temocillin in peritonitis

The therapeutic efficacy of the new beta-lactam antibiotic, temocillin, was studied in 30 critically ill patients with peritonitis, abscesses, bronchopneumonia, and serious soft tissue infections. Patients were treated with temocillin Ig intravenously twice daily. The isolated pathogens comprised mainly Escherichia coli and Proteus, but enterococci, Pseudomonas species, Klebsiella pneumoniae, Citrobacter species, Bacteroides species, streptococci and peptococci were also implicated. Temocillin was effective in 21/22 patients with peritonitis, as well as in 6/8 patients with long-lasting infections due to temocillin-sensitive pathogens. No adverse reactions to temocillin were observed. The indications for temocillin in patients undergoing abdominal surgery are discussed.