Inhibition of prostaglandin synthesis up-regulates cyclooxygenase-2 induced by lipopolysaccharide and peroxisomal proliferators

Primary cultures of fetal hepatocytes expressed cyclooxygenase-2 (COX-2) upon stimulation with bacterial lipopolysaccharide (LPS) or peroxisomal proliferators. This enzyme was active and a good correlation between the mRNA levels, the amount of protein, and the synthesis of prostaglandin E2 was observed. However, when cells were incubated in the presence of indomethacin or the COX-2-specific inhibitor NS398, the amount of COX-2 protein increased 5-fold after activation with LPS and 2-fold after treatment with clofibrate. This up-regulation of COX-2 was not observed at the mRNA level. The mechanism of protein accumulation might involve either a direct stabilization of the enzyme by the inhibitors or the absence of prostaglandins involved in the regulation of its turnover. Among the prostaglandins assayed, only 15-deoxy-Prostaglandin J2 exerted a statistically significant decrease in the COX-2 levels in cells stimulated with LPS or LPS plus NS398. The accumulation of COX-2 in the presence of inhibitors was also observed in peritoneal macrophages treated under identical conditions. These results indicate that COX-2 protein accumulates after enzyme inhibition, and because removal of the inhibitors restored the enzyme activity, suppression of treatment with reversible COX-2 inhibitors may cause a transient overproduction of prostaglandins.     

Exercise-induced signs of muscle overuse in children

Signs of overuse after intense muscular exertion are well described in adults, while little research has been conducted in children. The aim of the study was to investigate some indirect markers of muscle damage in 13 years old boys following two different protocols of one-leg stepping exercise to exhaustion. This stepping exercise was performed by two experimental groups with different contributions of concentric and eccentric contractions in a 1:1 vs 1:2 ratio of timing. Subjective soreness perception and maximum voluntary isometric force of the knee extensor muscles were measured immediately prior to and immediately following the exercise, and at 1, 3, 24, 48, 72, 96 hours post exercise. Metabolic markers of exercise stress were taken at similar time intervals and included plasma glutathione concentrations as a marker for oxidative stress, circulating leukocyte numbers, and plasma creatine kinase (CK) activity. All parameters studied demonstrated a higher level of muscular exertion, with more evident signs of overuse in the group with the more eccentric contribution. Complete recovery was achieved between 72 and 96 hours after exertion. However, in this group of boys, the CK activity did not show the typical adult-like increase. Therefore the wide use of CK as an indicator of intense muscle exertion was not supported in this group of children. It can be concluded that children, like adults, experience similar degrees of muscle disturbances following intense exercise and that they may recover more quickly from such exercise.     

Olfactory esthesioneuroblastoma: scintigraphic expression of somatostatin receptors

Esthesioneuroblastoma is an uncommon tumor originating in the upper nasal cavity and constitutes 3% of all intranasal neoplasms. Few references exist about the expression of somatostatin receptors in these tumors. Our case demonstrates a good correlation between the somatostatin receptor scintigraphy and magnetic resonance imaging.     

Percutaneous drainage of infected pancreatic necrosis: an alternative to surgery

AIM OF THE STUDY: To describe a technique of percutaneous CT guided catheter drainage of infected pancreatic necrosis and to report the results of this technique compared with those of the conventional surgical treatment and of other percutaneous drainage series. PATIENTS AND METHODS: Between 1992 and 1997, the series included 32 patients who had a severe acute necrotizing pancreatitis with a mean Ranson score of 4.6, scored into grade D (n = 10), and grade E (n = 22), according to the Balthazar radiological staging. Modified Van Sonnenberg 24 F double lumen catheters were used for continuous irrigation and aspiration. RESULTS: Forty-nine drains were inserted for 41 infected necroses and eight abscesses. Among the 32 patients, the proof of infected necrosis was obtained in 26 patients by fine needle aspiration and culture (enterococcus, staphylococcus, pseudomonas). The average delay of catheter insertion was 23 days after onset of pancreatitis; the mean duration of drainage was 43 days, and an average of three catheters per patient was required. Five patients (15%) died, and among the survivors, 16 (59%) presented 21 complications including 14 enterocutaneous or pancreatic fistulas. A subsequent surgical procedure including two necrosectomies was necessary in six patients. CONCLUSION: This study demonstrates that percutaneous drainage of infected pancreatic necrosis with a 15% mortality and 70% success rate, represents an interesting alternative to conventional surgery.     

Surgical Findings in Idiopathic Trigeminal Neuropathy Mimicking a Trigeminal Neurinoma

Summary  Idiopathic trigeminal neuropathy is a benign disorder where the main clinical feature is facial numbness limited to the territory of one or more divisions of the trigeminal nerve, persisting for a few weeks to several years and in which no underlying disease can be identified. The case of a 37-year-old man with a brief history of sensory and motor trigeminal symptoms who showed magnetic resonance imaging (MRI) findings consistent with a small trigeminal neurinoma is reported. The patient was operated on but no tumour could be found during surgery and a biopsy was taken from the portio major. Pathological diagnosis was chronic non granulomatous inflammatory reaction with areas of coagulation necrosis. Control MRI showed complete resolution of the trigeminal abnormalities. It is concluded that in patients with MRI findings suggestive of a small trigeminal schwannoma, benign idiopathic trigeminal neuropathy should also be considered in the differential diagnosis. A conservative approach with sequential MRI studies may avoid an unnecessary surgical exploration.     

Closed suction drainage after knee arthroplasty. A prospective study of the effectiveness of the operation and of bacterial contamination

A prospective investigation was designed to determine the volume and the evolution of bleeding after closure of the surgical wound following knee arthroplasty, as well as the incidence of infection and bacterial contamination in relation with the time that the suction drain was left in place. The drain was removed either 12, 24 or 48 hours after the operation. The presence of any signs of clinical infection was recorded. The tip of the drain, 1 cm of its subcutaneous portion and a sample from the collecting bottle were studied for bacterial contamination. In the 12-hr group, no microorganisms were isolated in cultures either from the tip, the subcutaneous portion or the bottle of the drain. In the 24-hr group, 87% of the total postoperative bleeding was collected during the first 12 hours. In two cases, the samples obtained from the tip and the subcutaneous portion of the drain were positive for Staphylococcus epidermidis. In the 48-hr group, 91% and 97% of the total bleeding volume was collected during the first 12 and 24 hours, respectively. In two cases, St. epidermidis was isolated in cultures from the subcutaneous portion of the drain. The clinical evaluation of wound healing was comparable in all three groups.     

Prime causes of rapid cardiomyocyte death during reperfusion

In ischemic-reperfused myocardium, necrosis of cardiomyocytes may develop not only due to the ischemic conditions but also the specific circumstances of reperfusion. The existence of reperfusion injury becomes apparent when modifications of the conditions of reperfusion can prevent cell death otherwise occurring. Three prime causes of rapidly developing reperfusion injury are here discussed, ie, reenergization of cells at increased cytosolic Ca2+ contents, rapid normalization of tissue pH, and rapid normalization of tissue osmolality. All three causes lead to severe mechanical stress of cardiomyocytes which can cause their rapid deterioration. Propagation of cell injury among adjacent cells can cause a spreading of necrosis throughout myocardial tissue. The understanding of these initial causes of rapidly developing lethal reperfusion injury leads to new concepts for specific protection of reperfused myocardium.