Cariporide counteracts atherosclerosis-related functions in monocytes from obese and normal individuals

OBJECTIVE: This study aimed to show the effect of high glucose concentrations in combination with a pharmaceutical analog of the Na+/H+ antiport inhibitor, cariporide, on scavenger receptor CD36 expression, cell adhesion, and cell migration of human monocytes derived from obese and normal individuals. RESEARCH METHODS AND PROCEDURES: Monocytes were isolated from six healthy obese individuals and six healthy age- and sex-matched controls by use of whole blood Percoll sedimentation and plastic surface monocyte binding. The density of CD36 scavenger receptors on the surface of monocytes was assessed by the use of a fluorescent fluorescein isothiocyanate (FITC)-linked monoclonal antibody. Transmigration of monocytes through laminin-1-coated filters was performed on 5-microm pore Transwell culture inserts. Monocyte attachment to laminin was estimated by a solid phase assay. RESULTS: High glucose concentrations caused an increase in monocytes from normal and obese individuals in the expression of CD36 receptors and positively influenced monocyte migration and adhesion to laminin. Cariporide together with glucose counteracted these effects. The effects of migration and adhesion of monocytes to laminin were specific to glucose, because the effect was significantly higher when monocytes were incubated in the presence of 20 mM of glucose than in the presence of 20 mM of fructose. Monocytes from obese subjects showed greater response than in normal to all of the studied effects, with the highest response in laminin attachment. DISCUSSION: The data of this study suggest that cariporide counteracts atherosclerosis-related functions through Na+/H+ antiport inhibition in monocytes from both normal and obese individuals.     

Relative citation impact of various study designs in the health sciences

Context  The relative merits of various study designs and their placement in hierarchies of evidence are often discussed. However, there is limited knowledge about the relative citation impact of articles using various study designs. Objective  To determine whether the type of study design affects the rate of citation in subsequent articles. Design and Setting  We measured the citation impact of articles using various study designs—including meta-analyses, randomized controlled trials, cohort studies, case-control studies, case reports, nonsystematic reviews, and decision analysis or cost-effectiveness analysis—published in 1991 and in 2001 for a sample of 2646 articles. Main Outcome Measure  The citation count through the end of the second year after the year of publication and the total received citations. Results  Meta-analyses received more citations than any other study design both in 1991 (P<.05 for all comparisons) and in 2001 (P<.001 for all comparisons) and both in the first 2 years and in the longer term. More than 10 citations in the first 2 years were received by 32.4% of meta-analyses published in 1991 and 43.6% of meta-analyses published in 2001. Randomized controlled trials did not differ significantly from epidemiological studies and nonsystematic review articles in 1991 but clearly became the second-cited study design in 2001. Epidemiological studies, nonsystematic review articles, and decision and cost-effectiveness analyses had relatively similar impact; case reports received negligible citations. Meta-analyses were cited significantly more often than all other designs after adjusting for year of publication, high journal impact factor, and country of origin. When limited to studies addressing treatment effects, meta-analyses received more citations than randomized trials. Conclusion  Overall, the citation impact of various study designs is commensurate with most proposed hierarchies of evidence.      

Phototargeting oral black-pigmented bacteria

We have found that broadband light (380 to 520 nm) rapidly and selectively kills oral black-pigmented bacteria (BPB) in pure cultures and in dental plaque samples obtained from human subjects with chronic periodontitis. We hypothesize that this killing effect is a result of light excitation of their endogenous porphyrins. Cultures of Prevotella intermedia and P. nigrescens were killed by 4.2 J/cm2, whereas P. melaninogenica required 21 J/cm2. Exposure to light with a fluence of 42 J/cm2 produced 99% killing of P. gingivalis. High-performance liquid chromatography demonstrated the presence of various amounts of different porphyrin molecules in BPB. The amounts of endogenous porphyrin in BPB were 267 (P. intermedia), 47 (P. nigrescens), 41 (P. melaninogenica), and 2.2 (P. gingivalis) ng/mg. Analysis of bacteria in dental plaque samples by DNA-DNA hybridization for 40 taxa before and after phototherapy showed that the growth of the four BPB was decreased by 2 and 3 times after irradiation at energy fluences of 4.2 and 21 J/cm2, respectively, whereas the growth of the remaining 36 microorganisms was decreased by 1.5 times at both energy fluences. The present study suggests that intraoral light exposure may be used to control BPB growth and possibly benefit patients with periodontal disease.     

Pyogenic granuloma of the oral cavity: comparative study of its clinicopathological and immunohistochemical features

There are two histological types of pyogenic granuloma (PG) of the oral cavity: the lobular capillary hemangioma (LCH) and non-LCH type. The aim of the present study was to examine and compare the clinical features, etiological factors, diameter of vascular elements and immunohistochemical features of LCH and non-LCH histological types of PG to determine whether they are two distinct entities. Thirty cases of LCH and 26 cases of non-LCH PG were retrieved and retrospectively studied. Clinically, LCH PG occurred more frequently (66.4%) as sessile lesion whereas non-LCH PG occurred as pedunculated (77%). Non-LCH PG was associated more frequently (86.4%) with etiological factors. The lobular area of the LCH PG contained a greater number of blood vessels with small luminal diameter than did the central area of non-LCH PG. In the central area of non-LCH PG a significantly greater number of vessels with perivascular mesenchymal cells non-reactive for alpha-smooth muscle actin and muscle-specific actin was present than in the lobular area of LCH PG. The differences found in the present study suggest that the two histological types of PG represent distinct entities.     

Quantification of annular dilatation and papillary muscle separation in functional mitral regurgitation: role of anterior mitral leaflet length as reference

BACKGROUND: We hypothesized that anterior mitral leaflet length (ALL) does not differ significantly between normal subjects and patients with functional mitral regurgitation (FMR) and hence may be used as a reference measurement to quantify annular dilatation and papillary muscle separation. METHODS AND RESULTS: We prospectively studied 50 controls, 15 patients with systolic left ventricular dysfunction (LVD) with significant FMR, and 15 patients with LVD without significant FMR. Significant MR was defined as an effective regurgitant orifice area > or = 0.2 cm2 as measured by the flow convergence method. Annular diameter, interpapillary distance, and ALL were measured, and the following ratios were derived: annular diameter indexed to ALL (ADI) and interpapillary distance indexed to ALL (IPDI). There was no significant difference in ALL among the three groups. The mean ADI was 1.26 times controls in patients with LVD without significant FMR compared to 1.33 times controls in patients with LVD with significant FMR (P = 0.06, no significant difference between groups). The mean IPDI was 1.42 times controls in patients with LVD without significant FMR compared to 2.1 times controls in patients with LVD with significant FMR (P < 0.0001, significant difference between groups). CONCLUSION: There was no significant difference in ALL between controls and patients with LVD. ALL can be used as a reference measurement to quantify annular dilatation and papillary muscle separation in patients with FMR. Interpapillary distance but not annular diameter indexed to ALL correlates with severity of FMR.     

Retroclival epidural hematoma secondary to a longitudinal clivus fracture

Retroclival epidural hematomas (RCEDH) make part of posterior fossa epidural hematomas (PFEDH) and represent an extremely rare entity not always easily diagnosed with computerized tomography (CT) due to beam hardening artifacts. The authors present a case of a child-to our knowledge-the first reported until now-featured the rare combination of a longitudinal clivus fracture associated with concomitant epidural hematoma treated conservatively with favorable outcome of the patient.     

Participation of primary motor cortical neurons in a distributed network during maze solution: representation of spatial parameters and time-course comparison with parietal area 7a

Traditionally, primary motor cortex (M1) has been thought to be involved solely in planning and generating movements. Recent evidence suggests that the arm area of M1 plays a role in other functions, such as the representation of serial order (Pellizzer et al. 1995, Science 269:702–705; Carpenter et al. 1999, Science 283:1752–1757) and spatial processing (Georgopoulos et al. 1989, Science 243:234–236). Previous studies of such cognitive processes have used tasks in which a directed arm movement was required, raising a question as to whether this brain area is involved in cognitive processing per se, or whether such cognitive signals may be gated into the arm area of M1 only when arm movements are required. To study this question, we developed a task that required a spatial analysis of a complex visual stimulus, but required no arm movement as a response. In this task, monkeys were shown an octagonal maze. After an imposed delay of 2 to 2.5 s, they indicated whether a path that emanated from the center of the maze exited at the perimeter (exit maze) or terminated within the maze (no-exit maze) by pressing a pedal with their left or right foot, respectively. We recorded from 785 cells from the arm area of M1 from two monkeys during the delay period of the maze task. We found that cell activity was influenced by both the exit status and the direction of the path, beginning soon after the maze was displayed. This activity was not related to the activation of arm muscles, suggesting that the directional signals observed represented abstract spatial aspects of maze processing. Finally, we compared maze-related activity of M1 neurons with those recorded from posterior parietal area 7a, reported previously (Crowe et al. 2004). Interestingly, cells from each area exhibited similar properties. Both the exit status and path direction were encoded by cells in M1 and 7a, although to different extents. An analysis of the time-course of the neural representation of these factors revealed that area 7a and M1 begin to encode these factors at the same time, suggesting these brain areas are part of a distributed system performing the spatial computations involved in maze solution.     

Bactericidal effect of different laser systems in the deep layers of dentin

BACKGROUND AND OBJECTIVES: In recent years, various laser systems have gained importance in the field of laser-assisted endodontics, namely the Nd:YAG, the diode, the Er:YAG, and the Er,Cr:YSGG laser. Individual studies have been carried out so far, focusing on the respective wavelength, its specific bactericidal capabilities, and potential usefulness is root-canal disinfection. The present in vitro investigation however, was performed to compare the microbicidal effect of these laser systems under standardized conditions and to draw a conclusion upon their relative effectiveness in the deep layers of dentin. STUDY DESIGN/MATERIALS AND METHODS: In total, 360 slices of root dentin with a thickness of 1 mm were obtained by longitudinal cuts of freshly extracted human premolars. The samples were steam sterilized and subsequently inoculated with a suspension of either Escherichia coli or Enterococcus faecalis. After the incubation, the samples were randomly assigned to the four different laser systems tested. Each laser group consisted of two different operational settings and a control. The dentinal samples underwent "indirect" laser irradiation through the dentin from the bacteria-free side and were then subjected to a classical quantitative microbiologic evaluation. To assess the temperature increase during the irradiation procedure, additional measurements were carried out using a thermocouple. RESULTS: Microbiology indicated that all laser systems were capable of significant reductions in both test strains. At an effective output power of 1 W, E. coli was reduced by at least three log steps in most of the samples by the tested wavelengths, with the best results for the Er:YAG laser showing complete eradication of E. coli in 75% of the samples. E. faecalis, a stubborn invader of the root canal, showed minor changes in bacterial count at 1 W. Using the higher setting of 1.5 W, significant reductions of E. coli were again observed with all laser systems, where only the diode and the Er:YAG laser were capable of complete eradication of E. faecalis to a significant extent. There was no significant relation between the temperature increase and the bactericidal effect. CONCLUSIONS: The present study demonstrates that all the wavelengths investigated are suitable for the disinfection of even the deeper layers of dentin and may prove to constitute valuable tools in state-of-the-art endodontics.     

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae in Austria

OBJECTIVES: To determine the prevalence of antibiotic resistance and the distribution of serotypes among Streptococcus pneumoniae isolated in Austria. MATERIALS AND METHODS: A total of 2367 strains of S. pneumoniae were collected in an Austrian-wide surveillance system between 1996 and 2002. Isolates were tested for their susceptibility to penicillin and clarithromycin and were serotyped by the capsular swelling method. RESULTS: An overall rise in penicillin resistance was observed from 4.9% in 1996 to 10.0% in 2002 (including both intermediate-resistant and resistant strains). A rise in clarithromycin resistance was also recorded in this period. The overall distribution of serogroups/types remained relatively stable, with 23, 19, 6 and 14 being the most frequent ones. Whereas in 1996 penicillin resistance was predominantly associated with serotype 23F, in 1998 and 2002, resistance was most frequently found in isolates of serogroup 9 and serotype 14, respectively. Coverage rates for currently available vaccines ranged from 57.4% (7-valent) to 72.4% (23-valent) of all serotyped strains. CONCLUSIONS: This rise in pneumococcal resistance to penicillin and clarithromycin, and the change in distribution of serotypes in these resistant strains, indicates that ongoing surveillance programmes are warranted, in order to be able to formulate both effective vaccination strategies and optimal antibiotic therapies.