Human endothelial cell storage granules: a novel intracellular site for isoforms of the endothelin-converting enzyme

The participation of oxidative mechanisms in major histocompatibility complex (MHC) class II-restricted antigen presentation was studied in vitro. In general, antigen processing is inhibited when peritoneal macrophages (MO) are incubated with scavengers of reactive oxygen intermediates (ROI): mannitol (an.OH scavenger), dimethylurea (DMTU, which reacts with H2O2 and HOCl) and NCO-700 (an epoxysuccinic acid derivative which inhibits oxidant production by activated phagocytes and can scavenge reactive oxygen species in both NaOCl and hypoxanthine (XOD) systems). However, neither rotenone and antimycins (inhibitors of O-2 production at the NADH dehydrogenase and ubiquinone-cytochrome b regions, respectively) nor aminoguanidine (an inducible nitric oxide synthase inhibitor) impaired antigen presentation, thus indirectly discarding the participation of mitochondrial oxidation and reactive nitrogen intermediates (RNI) in antigen processing. ROI scavengers do not inhibit the MHC class II-restricted presentation of antigens that need processing but have their disulphide bonds reduced. It can be shown that oxidation of protein antigens (either by chlorination or performic acid treatment) allow protein unfolding and enhance both processing and exposure of immunogenic epitopes to specific T cells.     

AN EPR STUDY OF FREE RADICALS GENERATED BY GAMMA-RADIATION OF DRIED SPICES AND SPRAY-DRIED FRUIT POWDERS

Gamma-radiation of powdered tumeric, black pepper, dry mustard, cinnamon and paprika, at dosage of 30 kGy, at 30°C, produced free radicals detectable by EPR. The intensities of the EPR signals were proportional to the total irradiation dose up to a saturation dose. The signal decayed most significantly in the first four-postirradiation days, but could be detected even after 34 days. The paramagnetic signal was unaffected by the presence of oxygen, but decayed rapidly in water. Similar observations were made for spray-dried fruit powder.     

Clinical trials on intracoronary stenting

The stent is currently taking the lead in the treatment of obstructive coronary artery disease. The interest in this device is not only reflected by the relative number of patients referred for angioplasty and treated with a stent but also by the large number of clinical trials. These can be divided into trials assessing the safety and feasibility of the implantation of second generation or new stents, studies assessing novel treatment strategies and randomized clinical trials. With respect to the latter, they all compare stent implantation with balloon angioplasty. Of major importance will be the comparison of stent implantation with surgical revascularization of obstructive coronary artery disease. The increasing number of therapeutic options, however, confront the physician with the difficult choice and responsibility of selecting the most appropriate treatment. Therefore, systematic and objective evaluation of the available therapeutic approaches by means of appropriately designed trials is imperative. The purpose of this paper is to summarize and to put into perspective the various studies on intracoronary stenting. Distinction is made between observational studies testing a device or evaluating a new concept in intracoronary stenting and randomized clinical trials.     

Surgical manpower: past and present reality, estimates for 2000

The growth in the number of board-certified surgeons in the 1970s, projections of the need for surgeons in the year 2000, and possible factors softening the impact of surgical expansion are discussed in detail. The best index for the optimal supply of surgeons in the United States is related to the phenomenon of local community needs.     

A randomized comparative study on the safety and efficacy of clarithromycin and erythromycin in treating community-acquired pneumonia

BACKGROUND: Clarithromycin, a new macrolide, has distinct microbiological and pharmacokinetic advantages compared with erythromycin. This study was designed to compare the safety and efficacy of clarithromycin and erythromycin in the treatment of community-acquired pneumonia. METHODS: Forty adult patients, diagnosed with community-acquired pneumonia, were randomly arranged to received either clarithromycin 250 mg twice daily (20 patients) or erythromycin 500 mg four times daily (20 patients), over a period of 14 days each. RESULTS: There were no statistically significant differences between the two groups in terms of clinical cure (65% for clarithromycin, 65% for erythromycin), clinical success (clinical cure and improvement: 95% for clarithromycin, 90% for erythromycin) and radiological response (95% for clarithromycin, 90% for erythromycin). However, adverse effects, mainly gastrointestinal, were significantly higher among patients treated with erythromycin than among patients treated with clarithromycion (p < 0.05). CONCLUSIONS: These results demonstrate that clarithromycin 250 mg twice daily is at least as effective as erythromycin 500 mg four times daily for the treatment of community-acquired pneumonia, and is much better tolerated.