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Selected AbstractsMetronidazole Increases Intracolonic but Not Peripheral Blood Acetaldehyde in Chronic Ethanol-Treated RatsALCOHOLISM, Issue 4 2000Jyrki Tillonen Background: Metronidazole leads to the overgrowth of aerobic flora in the large intestine by reducing the number of anaerobes. According to our previous studies, this shift may increase intracolonic bacterial acetaldehyde formation if ethanol is present. Metronidazole is also reported to cause disulfiram-like effects after alcohol intake, although the mechanism behind this is obscure. Therefore, the aim was to study the effect of long-term metronidazole and alcohol treatment on intracolonic acetaldehyde levels and to explore the possible role of intestinal bacteria in the metronidazole related disulfiram-like reaction. Methods: A total of 32 rats were divided into four groups: controls (n= 6), controls receiving metronidazole (n= 6), ethanol group (n= 10), and ethanol and metronidazole group (n= 10). All rats were pair-fed with the liquid diet for 6-weeks, whereafter blood and intracolonic acetaldehyde levels and liver and colonic mucosal alcohol (ADH) and aldehyde dehydrogenase (ALDH) activities were analyzed. Results: The rats receiving ethanol and metronidazole had five times higher intracolonic acetaldehyde levels than the rats receiving only ethanol (431.4 ± 163.5 ,M vs. 84.7 ± 14.4 ,M, p= 0.0035). In contrast, blood acetaldehyde levels were equal. Cecal cultures showed the increased growth of Enterobacteriaceae in the metronidazole groups. Metronidazole had no inhibitory effect on hepatic or colonic mucosal ADH and ALDH activities. Conclusions: The increase in intracolonic acetaldehyde after metronidazole treatment is probably due to the replacement of intestinal anaerobes by ADH-containing aerobes. Unlike disulfiram, metronidazole neither inhibits liver ALDH nor increases blood acetaldehyde. Thus, our findings suggested that the mechanism behind metronidazole related disulfiram-like reaction might be located in the gut flora instead of the liver. [source] Efficacy of Single Lead VDD Pacing in Patients with Impaired and Normal Left Ventricular FunctionPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2000ANDREAS SCHUCHERT Atrial synchronous ventricular pacing seems to be the best pacing mode for patients with advanced AV block and impaired LV function. The long-term follow-up of single lead VDD pacing was studied in 33 patients with impaired LV function and compared to 42 patients with normal LV function. All patients received the same VDD lead and VDDR pacemaker. The lead model with 13-cm AV spacing between the atrial and ventricular electrode was implanted in 89% of the patients. Follow-ups were 1, 3, 6, and 12 months after implantation. The percentage of atrial sensing and the P wave amplitude were determined at each follow-up. Minimal P wave amplitude at implantation was 2.0 ± 1.4 mV in patients with impaired and 1.7 ± 0.9 mV with normal LV function (not significant). At the 12-month follow-up, 33 patients with normal and 23 patients with depressed LV function remained paced in the VDD mode. The remaining patients died in five (impaired LV function) and seven cases (normal LV function) or their pacemakers were programmed to the VVI/VVIR pacing mode in four (impaired LV function) and three cases (normal LV function). P wave amplitude did not differ in the two groups (e.g., at month 12: impaired: 1.17 ± 0.42 mV; normal: 1.09 ± 0.49 mV). The atrial sensitivity was programmed in most patients to sensitive settings with no differences between the two groups (e.g., at month 12: impaired: 0.13 ± 0.06 mV; normal: 0.13 ± 0.05 m V). The diagnostic counters indicated nearly permanent atrial sensing (e.g., at month 12: impaired: 99.3 ± 2.2%; normal: 99.0 ± 1.0 mV). In conclusions, single lead VDD pacing restored AV synchronous ventricular pacing in patients with normal and with impaired LV function indicating that it could be an alternative to DDD pacemakers, but not to dual-chamber pacing. [source] Intima-media thickness of radial artery is associated with early access failure in hemodialysis patientsHEMODIALYSIS INTERNATIONAL, Issue 1 2005Y.O. Kim Objective:,We have reported that intimal hyperplasia, which is the pathologic change of the radial artery, is associated with early failure of arteriovenous fistula (AVF) in hemodialysis (HD) patients (Am J Kidney Dis, 41:422,428, 2003). Intima-media thickness (IMT), which represents the whole thickness of arterial wall, can be easily measured by ultrasonography, unlike intima thickness. This study was performed to investigate the impact of IMT of radial artery on early failure of AVF in HD patients. Methods:,Ninety HD patients undergoing radiocephalic AVF operation were included in this study. The AVF was constructed in an end vein,to,side artery fashion at the wrist by one vascular surgeon. During the operation, 10-mm long partial arterial walls were removed with elliptical form for microscopic analysis. Specimens were stained with trichrome and examined by a pathologist blinded to the clinical data. AVF patency was prospectively followed up for 1 year after the operation. Results:,Mean age of the patients was 56 ± 13 years and the number of females was 44 (48.9%). Mean IMT was 430 ± 132 ,m (133,760 ,m). Of the total 90 patients, 31 patients (34.4%) had AVF failure within 1 year after the operation. Mean IMT was higher in the failed group (n = 31) than in patent group (n = 59)(486 ± 130 ,m vs. 330 ± 178 ,m, p = 0.004). Using a threshold of 500 ,m of IMT, AVF patency rate was compared between these two groups using Kaplan-Meier method with log rank test. The AVF patency rate within 1 year after the operation was higher in patients with IMT , 500 ,m (n = 26) than in patients with IMT < 500 ,m (n = 64)(p < 0.001). The patients with IMT , 500 ,m were older and had higher incidence of diabetes mellitus, compared to the patients with IMT < 500 ,m. There was no difference in sex, smoking, hypertension, total cholesterol and albumin levels between the two groups. Conclusion:,Our data suggest that increased intima-media thickness of radial artery is associated with early failure of radiocephalic arteriovenous fistula in hemodialysis patients. [source] A Separate Role for ICAM-1 and Fluid Shear in Regulating Leukocyte Interactions with Straight Regions of Venular Wall and Venular ConvergencesMICROCIRCULATION, Issue 6 2009RONEN SUMAGIN ABSTRACT Objective: Variation in expression of adhesion molecules plays a key role in regulating leukocyte behavior, but the contribution of fluid shear to these interactions cannot be ignored. Here, we dissected the effects of each of these factors on leukocyte behavior in different venular regions. Materials and Methods: Leukocyte behavior was quantified in blood-perfused microvascular networks in anesthetized mouse cremaster muscle, using intravital confocal microscopy. ICAM-1 expression and fluid shear rate were quantified by using ICAM-1 fluorescent labeling, fluorescent particle tracking, and computational fluid dynamics. Results: Tumor necrosis factor alpha induced an increase in ICAM-1 expression and abolished the differences observed among control venules of different sizes. Consequently, leukocyte adhesion was increased to a similar level across all vessel sizes [5.1±0.46 leukocytes/100 ,m vs. 2.1±0.47 (control)], but remained significantly higher in venular convergences (7.8±0.4). Leukocyte transmigration occurred primarily in the smallest venules and venular convergences (23.9±5.1 and 31.9±2.7 leukocytes/10,000 ,m2 tissue, respectively). In venular convergences, the two inlet vessels are predicted to create a region of low velocity, increasing leukocyte adhesion probability. Conclusions: In straight regions of different-sized venules, the variability in ICAM-1 expression accounts for the differences in leukocyte behavior; in converging regions, fluid shear potentially has a greater effect on leukocyte endothelial cell interactions. [source] The 6-minute walk test as a new outcome measure in Duchenne muscular dystrophyMUSCLE AND NERVE, Issue 4 2010Craig M. McDonald MD Abstract Walking abnormalities are prominent in Duchenne muscular dystrophy (DMD). We modified the 6-minute walk test (6MWT) for use as an outcome measure in patients with DMD and evaluated its performance in 21 ambulatory boys with DMD and 34 healthy boys, ages 4 to 12 years. Boys with DMD were tested twice, ,1 week apart; controls were tested once. The groups had similar age, height, and weight. All tests were completed. Boys who fell recovered rapidly from falls without injury. Mean ± SD [range] 6-minute walk distance (6MWD) was lower in boys with DMD than in controls (366 ± 83 [125,481] m vs. 621 ± 68 [479,754] m; P < 0.0001; unpaired t -test). Test-retest correlation for boys with DMD was high (r = 0.91). Stride length (R2 = 0.89; P < 0.0001) was the major determinant of 6MWD for both boys with DMD and controls. A modified 6MWT is feasible and safe, documents disease-related limitations on ambulation, is reproducible, and offers a new outcome measure for DMD natural history and therapeutic trials. Muscle Nerve, 2010 [source] Improvement of Congestive Heart Failure by Upgrading of Conventional to Resynchronization PacemakersPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2006IBRAHIM MARAI Aims: To compare the clinical response of patients with right ventricular apical pacing (RVAP) upgraded to cardiac resynchronization therapy (CRT) to that of previously nonpaced heart failure (HF) patients who had de novo CRT implantation. Background: The role of CRT in patients with wide QRS and HF due to RVAP is less well established than in other CRT candidates. Methods: Ninety-eight consecutive patients with CRT were studied (mean age 70, mean ejection fraction 0.23). Group A: patients having RVAP prior to CRT implantation (n = 25), group B: patients without prior RVAP (n = 73). Clinical and echocardiographic parameters were recorded prior to, and 3 months after, CRT implantation. Results: Group A patients had a wider QRS at baseline compared to group B (203 ± 32 ms vs 163 ± 30 ms respectively, P < 0.001), and a shorter 6-minute walking distance (222 ± 118 m vs 362 ± 119 m, respectively, P < 0.005). Otherwise, clinical and echocardiographic parameters were not different. At follow up, group A patients had an average 0.7 ± 0.5 decrease in their NYHA functional class, compared to 0.3 ± 0.7 in group B patients (P < 0.05). Six-minute walking distance increased by 93 ± 113 m in group A, versus 36 ± 120 m in group B (P = 0.22). There was no difference in echocardiographic response to CRT between the groups. Conclusions: HF patients with prior RVAP demonstrate clinical improvement after upgrading to CRT that is comparable, and in some aspects, even better than that observed in HF patients with native conduction delay who undergo de novo CRT implantation. [source] Preserving Normal Ventricular Activation Versus Atrioventricular Delay Optimization During Pacing: The Role of Intrinsic Atrioventricular Conduction and Pacing RatePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2000IVAN ILIEV ILIEV The purpose of the study was to compare the effects of DDD pacing with optimal AV delay and AAI pacing on the systolic and diastolic performance at rest in patients with prolonged intrinsic AV conduction (first-degree AV block). We studied 17 patients (8 men, aged 69 ± 9 years) with dual chamber pacemakers implanted for sick sinus syndrome in 15 patients and paroxysmal high degree AV block in 2 patients. Aortic flow and mitral flow were evaluated using Doppler echocardiography. Study protocol included the determination of the optimal A V delay in the DDD mode and comparison between AAI and DDD with optimal A V delay for pacing rate 70/min and 90/min. Stimulus-R interval during AAI (AHI) was 282 ± 68 ms for rate 70/min and 330 ± 98 ms for rate 90/min (P < 0.01). The optimal A V delay was 159 ± 22 ms, A V delay optimization resulted in an increase of an aortic flow time velocity integral (AFTVI) of 16%± 9%. At rate 70/min the patients with ARI , 270 ms had higher AFTVI in AAI than in DDD (0.214 ± 0.05 m vs 0.196 ± 0.05 m, P < 0.01), while the patients with ARI > 270 ms demonstrated greater AFTVI under DDD compared to AAI(0.192 ± 0.03 m vs 0.166 ± 0.02 m, P < 0.01). At rate 90/min AFTVI was higher during DDD than AAI (0.183 ± 0.03 m vs 0.162 ± 0.03 m, P < 0.01). Mitral flow time velocity integral (MFTVI) at rate 70/min was higher in DDD than in AAI (0.189 ± 0.05 m vs 0.173 ± 0.05 mP < 0.01), while at rate 90/min the difference was not significant in favor of DDD (0.149 ± 0.05 m vs 0.158 ± 0.04 m). The results suggest that in patients with first-degree AV block the relative impact of DDD and AAI pacing modes on the systolic performance depends on the intrinsic AV conduction time and on pacing rate. [source] Bridging Mucosal Vessels Associated with Rhythmically Oscillating Blood Flow in Murine ColitisTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2008Aslihan Turhan Abstract Oscillatory blood flow in the microcirculation is generally considered to be the result of cardiopulmonary influences or active vasomotion. In this report, we describe rhythmically oscillating blood flow in the bridging vessels of the mouse colon that appeared to be independent of known biological control mechanisms. Corrosion casting and scanning electron microscopy of the mouse colon demonstrated highly branched bridging vessels that connected the submucosal vessels with the mucosal plexus. Because of similar morphometric characteristics (19 ± 11 ,m vs. 28 ± 16 ,m), bridging arterioles and venules were distinguished by tracking fluorescent nanoparticles through the microcirculation using intravital fluorescence videomicroscopy. In control mice, the blood flow through the bridging vessels was typically continuous and unidirectional. In contrast, two models of chemically induced inflammation (trinitrobenzenesulfonic acid and dextran sodium sulfate) were associated with a twofold reduction in flow velocity and the prominence of rhythmically oscillating blood flow. The blood oscillation was characterized by tracking the bidirectional displacement of fluorescent nanoparticles. Space,time plots and particle tracking of the oscillating segments demonstrated an oscillation frequency between 0.2 and 5.1 cycles per second. Discrete Fourier transforms demonstrated a power spectrum composed of several base frequencies. These observations suggest that inflammation-inducible changes in blood flow patterns in the murine colon resulted in both reduced blood flow velocity and rhythmic oscillations within the bridging vessels of the mouse colon. Anat Rec, 291:74,82, 2007. © 2007 Wiley-Liss, Inc. [source] Two New Species of Symbiotic Ciliates from the Respiratory Tract of Cetaceans with Establishment of the New Genus Planilamina n. gen. (Dysteriida, Kyaroikeidae)THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 6 2006HONGWEI MA ABSTRACT. Examination of mucus discharged from the blowhole of Atlantic bottlenose dolphin (Tursiops truncatus) at Marine Life Oceanarium, Gulfport, Mississippi, and false killer whale (Pseudorca crassidens) and Atlantic bottlenose dolphin at SeaWorld Orlando, Orlando, Florida, using live observations and protargol impregnation revealed mixed infections of Kyaroikeus cetarius and two new species. Planilamina n. gen. is characterized by a C-shaped argentophilic band located along the laterally flattened margin of cell and extending from the cell apex to subposterior cone-shaped podite; a deep oral cavity containing one short preoral kinety, two circumoral kineties, seven to 13 infundibular kineties, and a cytostome; a broadly funnel-shaped cytopharynx reinforced by argentophilic fibers but without nematodesmata; closely packed postoral kinetofragments set in a pocket located anterior left of the podite; and somatic kineties as a right field closely situated at the right surface and a left field bordering the anterior left margin of the oral cavity. The type species for the genus, Planilamina ovata n. sp., is distinguished from its sister species Planilamina magna n. sp. by the following characteristics: body size (28,65 × 20,43 ,m vs. 57,90 × 40,63 ,m), number of right field kineties (38,55 vs. 79,99), and position of the anterior end of the leftmost kinety in the right somatic field (anterior one-third vs. mid-body). The morphogenesis of Planilamina ovata is similar to that of K. cetarius. The diagnosis of Kyaroikeidae is emended to accommodate the new genus. [source] Female-biased natal and breeding dispersal in an alpine lizard, Niveoscincus microlepidotusBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2003MATS OLSSON We measured two aspects of dispersal in the alpine Australian scincid lizard, Niveoscincus micolepidotus: (1) natal dispersal, i.e. shift in home range over the lizard's first year of life, and (2) breeding dispersal, i.e. shifts of home ranges between breeding attempts as adults. On average, displacements were surprisingly small. Female neonates dispersed about twice as far as did males in the same cohort (means of 12 m vs. 6 m). A female's natal dispersal distance was not correlated with her body size or our estimate of physiological performance (sprint speed). However, larger, faster-running male neonates dispersed further than did smaller, slower males. As was the case for neonates, adult females moved significantly further between breeding seasons than did adult males (14.2 m vs. 9.6 m). Because of a female's long gestation period (more than 1 year), two groups of females occur simultaneously in the population, non-ovulated (i.e. with yolking folicles) and pregnant females (i.e. approaching parturition). Females that were not yet ovulated showed a markedly stronger dispersal in response to high reproductive effort (i.e. clutch size in relation to body condition) than did pregnant females. In adult males, body size was negatively correlated with dispersal distance, suggesting that although males have overlapping territories, they exhibit an increasing level of site tenacity with age and/or size. Thus, selection for the relatively more pronounced site tenacity in adult males may have resulted in the more marked philopatric behaviour compared to females also as neonates. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 79, 277,283. [source] | |||||||||||||