Methionine-Enkephalin Primes Human Neutrophils for Enhanced Superoxide Anion Production

Methionine-enkephalin (MENK) is not an effective stimulus for inducing the superoxide (O^-₂) generation of human neutrophils, but it enhanced the O^-₂ generation stimulated by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) or human recombinant interferon gamma (hrIFNγ) when the cells had been preincubated with MENK for 30 min at 37°C. The priming effect of MENK was not observed with stimulus such as lipopolysaccharide (LPS) or phorbol-12-myristate-13-acetate (PMA). The enhancing effect of MENK was abrogated if cells were treated with protein kinase C (PKC) inhibitor H7 (1-(5-isoquinolinylsulfonyl)-2-methylpiperazine) before fMLP or IFNγ. This finding indicates that MENK is a potent modulator of human neutrophils and can contribute to inflammatory process.     

A quantitative evaluation of osteoblast-osteocyte relationships on growing endosteal surface of rabbit tibiae.

Scanning electron microscopy (SEM) was used to quantify the intercellular relationships between osteoblasts and osteocytes on the growing endosteal surfaces of the medullary canal of the tibia in four rabbits of different ages. The area of each osteoblast was measured on the SEM micrographs by means of an Image Analyzer. The number of osteocyte cytoplasmic processes was indirectly evaluated by counting the canalicular openings present on the same microscopic fields after the removal of the osteoblasts. The metabolic activity of the osteoblasts was indirectly evaluated from their shape, and the structure was analyzed by transmission electron microscope (TEM) in sections taken from the samples studied by SEM. In all four animals, the surface area of the osteoblasts (OA) was found to vary a great deal, whereas the density of canalicular openings was fairly uniform. Moreover, although the OA mean value increases significantly with the age of the animals, the density of canalicular openings does not; it would therefore appear that the older the animal and the more flattened the osteoblasts, the greater the number of canaliculi beneath them. Since osteoblast activity has previously been shown to be inversely proportional to the area of the protoplasm in contact with the bone surface, it appears that the less active osteoblasts should contact a greater number of osteocyte cytoplasmic processes. These findings suggest that osteocytes might play an important role in modulating osteoblast activity and in recruiting osteoblasts that differentiate into osteocytes, possibly by means of inhibitory signals transmitted via gap junctions.     

Posttransplant renal rejection: comparison of quantitative scintigraphy, US, and MR imaging

Accuracy of ultrasonography (US), quantitative scintigraphy, and magnetic resonance (MR) imaging in diagnosis of acute renal allograft rejection was studied in 46 patients who underwent renal biopsy. Thirty-three patients had acute rejection; six, cyclosporine nephrotoxicity, as shown by biopsy, clinical findings, and follow-up study; two, acute tubular necrosis; and five, normal biopsy findings and renal function. Accuracy in demonstrating rejection was 72% for US and 75% for scintigraphy, indicating no significant difference between the two. MR imaging was significantly more accurate, reaching a level of 98%. However, accuracy of MR in demonstrating acute tubular necrosis in a larger number of patients is not known, and its accuracy in indicating recurrent glomerulopathy or infectious disease has not been addressed. The definitive role of MR in evaluating posttransplant renal failure is currently not established, but because of its high sensitivity in detecting renal abnormality, MR can be used for cases when results of US or scintigraphy are equivocal or contradict clinical impressions or when biopsy cannot be performed for medical reasons.     

Normal penile anatomy and abnormal penile conditions: evaluation with MR imaging

The appearance of the normal penis and of a variety of penile abnormalities on magnetic resonance (MR) images was studied in 55 patients with either medium (0.35 T) or high (1.5 T) magnetic field strengths. Penile morphologic characteristics with anatomic detail of the corpora cavernosa and corpus spongiosum were demonstrated in each patient. MR images clearly displayed congenital anomalies (n = 6), penile prostheses (n = 7), fibrous tissue or hematoma due to trauma (n = 8), and fibrous plaque in Peyronie disease (n = 3). MR imaging also demonstrated urethral (n = 6) and penile (n = 5) neoplasms and allowed tumor staging, thus facilitating the surgical approach.     

Thymic influence of proliferation and interaction of fractionated spleen cells of mice.

Cells from the spleens of mice were separated into seven subpopulations by centrifugation on a discontinuous density gradient of dextran. The lightest fraction (containing stem cells), the three heaviest fractions (containing small lymphocytes), or a mixture of these, were injected into thymectomized or sham-thymectomized irradiated mice together with sheep red blood cells as antigen. After 8 days, the spleens of treated mice were tested for their content of cells lysing sheep red blood cells in agar (PFC) or cells mounting graft-versus-host reaction in newborn mice (GVHR). Heavy fractions were depleted of progenitors of PFC, but contained progenitors of cells mounting GVHR. The light fraction was depleted of both. If light cells were given together with heavy ones, the potential to generate PFC was restored, but only if the recipients were without their thymus; by contrast, the potential to generate GVH-reactive cells was strongly suppressed in the absence of a thymus. It is concluded that, in this model, stem cells probably interact with immunocompetent cells, and that the interaction depends on the thymus.     

Detection and staging of renal neoplasms: a reassessment of MR imaging

The use of magnetic resonance (MR) imaging in the detection and staging of renal neoplasms was investigated in 104 patients with 106 renal cell carcinomas confirmed at surgery or autopsy. Overall, MR imaging demonstrated 101 of 106 lesions (95%), including all 93 tumors that were larger than 3 cm in diameter but only eight of the 13 smaller tumors (62%). MR imaging enabled accurate staging of 82% of all detected lesions but led to the understaging of nine lesions and the overstaging of nine. At present, MR imaging cannot be used as a screening modality for renal tumors. However, its negative predictive values of 98% and 99%, respectively, for the evaluation of tumor vascular extension and tumor spread to adjacent structures makes it an excellent staging modality that should be used when the CT findings are equivocal. MR imaging is not accurate in indicating bowel and mesentery involvement, but rapid technical advances and the introduction of bowel contrast medium may improve this present limitation.     

Impression of Subgingival Dental Preparation Can Be Taken with Ultrasound

Because of its ability to capture hard structures behind soft tissue, ultrasound-based micro-scanning may be a promising alternative for taking digital impressions of teeth, especially in the case of subgingival margin preparations. The aim of this study was to assess the accuracy of ultrasound impressions taken of subgingivally prepared teeth compared with digital optical impressions. Ten extracted human teeth (7 pre-molars, 3 molars) were prepared for crowns with chamfer finish line and then digitized using two different intra-oral scanners (Cara Trios, 3 Shape, Heraeus Kulzer, Hanau, Germany; and Lava COS; 3M ESPE, Seefeld, Germany) and one extra-oral scanner (Cares CS2, Straumann, Basel, Switzerland). Afterward, the preparation margin was covered with porcine gingiva (thickness ranged between 0.3 and 0.9 mm), and every sample was scanned with a high-frequency ultrasound scanner under experimental subgingival conditions. Optical scanning processes were performed without gingiva. The data sets were superimposed on each other for pairwise comparisons, and deviations between different scans were determined using a 3-D evaluation software (CloudCompare). Kruskal–Wallis and post hoc tests (Dunn–Bonferroni) were applied to detect significant differences at p ≤ 0.05. The ultrasound scanner was able to detect subgingival preparation margins. Mean deviations for all comparisons ranged from 12.34 to 46.38 µm. There were no statistically significant differences between superimpositions of intra-oral and extra-oral scans (Trios–Lava, Lava–CS2, Trios–CS2), whereas in comparisons between intra-/extra-oral scans and ultrasound scans, mean deviations were statistically significantly higher. There were no significant differences with respect to type of tooth (pre-molar and molar). However, gingiva thickness was significantly correlated with the quality of the ultrasound scan; thin layers had better image quality than thicker layers. Ultrasound was able to scan tooth preparation margins covered with gingiva, although with less accuracy than achieved by conventional optical scanners (non-covered margins). Gingiva thickness may play an important role in ultrasound scan accuracy.     

The DISCOVERY PENTA study: a DIrect Statin COmparison of LDL-C Value--an Evaluation of Rosuvastatin therapY compared with atorvastatin

BACKGROUND: International guidelines emphasize the need to achieve recommended low-density lipoprotein cholesterol (LDL-C) levels in order to reduce morbidity and mortality associated with coronary heart disease (CHD). However, many patients with hypercholesterolemia fail to achieve LDL-C goals on treatment. OBJECTIVE: The primary objective was to compare the efficacy of rosuvastatin and atorvastatin for enabling patients to achieve National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) LDL-C goals. Secondary objectives were European LDL-C goal achievement, changes in the lipid profile, and safety. RESEARCH DESIGN AND METHODS: This 12-week, multicenter, multinational, randomized, open-label trial compared the efficacy and safety of rosuvastatin 10 mg with atorvastatin 10 mg in statin-na?ve and switched patients with primary hypercholesterolemia from Brazil, Colombia, Mexico, Portugal, and Venezuela. RESULTS: A total of 1124 patients with similar baseline characteristics were randomized to the two treatment groups. After 12 weeks of treatment, a significantly greater percentage of patients receiving rosuvastatin 10 mg compared with atorvastatin 10 mg achieved NCEP ATP III LDL-C goals (71.2% vs 61.4%, p < 0.001), 1998 European LDL-C goals (73.5% vs 59.2%, p < 0.001) and 2003 European LDL-C goals (58.9% vs 44.6%, p < 0.001). Rosuvastatin treatment was associated with significant reductions in LDL-C and total cholesterol (TC) and, in statin-na?ve patients, a significant increase in high-density lipoprotein cholesterol (HDL-C) compared with atorvastatin treatment. Both treatments were well tolerated with a similar incidence of adverse events. Clinically significant elevations in creatinine, creatine kinase or hepatic transaminases were low and similar between treatment groups. CONCLUSIONS: Rosuvastatin 10 mg is significantly more effective at achieving NCEP ATP III and European LDL-C goals, lowering LDL-C and TC in both na?ve and switched patients and increasing HDL-C in na?ve patients than atorvastatin 10mg, with a similar safety and tolerability profile. This study also provides evidence regarding the comparative effects of rosuvastatin versus atorvastatin in Latin American and Portuguese populations.