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Lumen Diameter (lumen + diameter)
Selected AbstractsFunctional morphology of the postpharyngeal gland of queens and workers of the ant Monomorium pharaonis (L.)ACTA ZOOLOGICA, Issue 2 2006Dieter Eelen Abstract Eelen D., Børgesen L.W. and Billen J. 2006. Functional morphology of the postpharyngeal gland of queens and workers of the ant Monomorium pharaonis (L.). ,Acta Zoologica (Stockholm) 87: 101,111 The postpharyngeal gland (PPG) is unique to ants and is the largest exocrine gland in their head. In queens of the pharaoh's ant, Monomorium pharaonis, the gland contains approximately 15 finger-like epithelial extensions on each side and opens dorsolaterally in the posterior pharynx. In these ants the PPG morphology varies considerably according to age and mating status. The epithelial thickness increases with age and reaches a maximum at 3 weeks in both virgin and mated queens. A considerable expansion of the lumen diameter occurs in both groups between 4 and 7 days. Virgin queens release their secretion into the gland lumen from an age of 7 days, whereas mated queens accumulate large amounts of secretion in their epithelium. The increasing epithelial thickness, together with the increasing lumen diameter, the presence of numerous inclusions in the epithelium and the release of secretion, are indicative for increasing gland activity. The gland ultrastructure indicates involvement in lipid metabolism and de novo synthesis of lipids. The PPG of workers consists of 12 finger-like tubes at each side. There is a significant difference in epithelial thickness between nurses and repletes and between nurses and foragers. We suggest the PPG serves different purposes in pharaoh's ants: it is likely that the PPG of workers and virgin queens is used to feed larvae. In mated queens the gland probably plays a role in providing the queen with nutritious oils for egg production. The PPG may also function in signalling species nestmate and caste identity, as well as in the reproductive capacity of the queens. [source] Variations in carotid arterial compliance during the menstrual cycle in young womenEXPERIMENTAL PHYSIOLOGY, Issue 2 2006Koichiro Hayashi The effect of menstrual cycle phase on arterial elasticity is controversial. In 10 healthy women (20.6 ± 1.5 years old, mean ±s.d.), we investigated the variations in central and peripheral arterial elasticity, blood pressure (carotid and brachial), carotid intima,media thickness (IMT), and serum oestradiol and progesterone concentrations at five points in the menstrual cycle (menstrual, M; follicular, F; ovulatory, O; early luteal, EL; and late luteal, LL). Carotid arterial compliance (simultaneous ultrasound and applanation tonometry) varied cyclically, with significant increases from the values seen in M (0.164 ± 0.036 mm2 mmHg,1) and F (0.171 ± 0.029 mm2 mmHg,1) to that seen in the O phase (0.184 ± 0.029 mm2 mmHg,1). Sharp declines were observed in the EL (0.150 ± 0.033 mm2 mmHg,1) and LL phases (0.147 ± 0.026 mm2 mmHg,1; F= 8.51, P < 0.05). Pulse wave velocity in the leg (i.e. peripheral arterial stiffness) did not exhibit any significant changes. Fluctuations in carotid arterial elasticity correlated with the balance between oestradiol and progesterone concentrations. No significant changes were found in carotid and brachial blood pressures, carotid artery lumen diameter, or IMT throughout the menstrual cycle. These data provide evidence that the elastic properties of central, but not peripheral, arteries fluctuate significantly with the phases of the menstrual cycle. [source] Assessment of bronchial wall thickness and lumen diameter in human adults using multi-detector computed tomography: comparison with theoretical modelsJOURNAL OF ANATOMY, Issue 5 2007M. Montaudon Abstract A thickened bronchial wall is the morphological substratum of most diseases of the airway. Theoretical and clinical models of bronchial morphometry have so far focused on bronchial lumen diameter, and bronchial length and angles, mainly assessed from bronchial casts. However, these models do not provide information on bronchial wall thickness. This paper reports in vivo values of cross-sectional wall area, lumen area, wall thickness and lumen diameter in ten healthy subjects as assessed by multi-detector computed tomography. A validated dedicated software package was used to measure these morphometric parameters up to the 14th bronchial generation, with respect to Weibel's model of bronchial morphometry, and up to the 12th according to Boyden's classification. Measured lumen diameters and homothety ratios were compared with theoretical values obtained from previously published studies, and no difference was found when considering dichotomic division of the bronchial tree. Mean wall area, lumen area, wall thickness and lumen diameter were then provided according to bronchial generation order, and mean homothety ratios were computed for wall area, lumen area and wall thickness as well as equations giving the mean value of each parameter for a given bronchial generation with respect to its value in generation 0 (trachea). Multi-detector computed tomography measurements of bronchial morphometric parameters may help to improve our knowledge of bronchial anatomy in vivo, our understanding of the pathophysiology of bronchial diseases and the evaluation of pharmacological effects on the bronchial wall. [source] Intima,media thickness of the abdominal aorta of neonate with different gestational agesJOURNAL OF CLINICAL ULTRASOUND, Issue 9 2007Esad Koklu MD Abstract Purpose. To determine aortic intima,media thickness (aIMT) values in newborns with different gestational ages and to asses the effect of antenatal steroids on aIMT. Methods. Two hundred forty newborns from healthy mothers had their distal abdominal aIMT measured during abdominal sonographic examination. The neonates were divided into 4 groups (60 in each group) according to gestational age: group I (25,28 weeks), group II (29,32 weeks), group III (33,37 weeks), and group IV (38,42 weeks). Results. The interobserver and intersubject intraclass correlation coefficient was 0.93 and 0.94, respectively. Mean aIMT was 0.316 mm, 0.335 mm, 0.348 mm, and 0.385 mm, respectively, in group I, II, III, and IV, increasing significantly with gestational age at birth (p < 0.0001). There was no apparent effect of antenatal steroid use on aIMT. Multivariate regression models for mean aIMT demonstrated a significant association with aortic lumen diameter (p < 0.0001). Conclusion. Abdominal aIMT can be reproducibly measured in neonates and may be a useful tool for epidemiologic studies. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007 [source] Xylem density, biomechanics and anatomical traits correlate with water stress in 17 evergreen shrub species of the Mediterranean-type climate region of South AfricaJOURNAL OF ECOLOGY, Issue 1 2007ANNA L. JACOBSEN Summary 1Climate change in South Africa may threaten the sclerophyllous evergreen shrubs of this region. Available data suggest that they are not as tolerant of water stress as chaparral shrubs occurring in climatically similar California, USA. 2Seventeen species from nine angiosperm families, including both fynbos and succulent karoo species, were studied at a field site in Western Cape Province, South Africa. Minimum seasonal pressure potential (Pmin), xylem specific conductivity (Ks), stem strength against breakage (modulus of rupture, MOR), xylem density, theoretical vessel implosion resistance () and several fibre and vessel anatomical traits were measured. 3Species displayed great variability in Pmin, similar to the range reported for chaparral and karoo shrub species, but in contrast to previous reports for fynbos shrubs. 4More negative Pmin was associated with having greater xylem density, MOR and . There was no relationship between Pmin and traits associated with increased water transport efficiency. 5Xylem density integrates many xylem traits related to water stress tolerance, including Pmin, MOR and , as well as percentage fibre wall, parenchyma, vessel area and fibre lumen diameter. 6Xylem density may be an integral trait for predicting the impact of climate change on evergreen shrubs. [source] Comparison between three-dimensional volume-selective turbo spin-echo imaging and two-dimensional ultrasound for assessing carotid artery structure and functionJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2005Lindsey A. Crowe PhD Abstract Purpose To compare a volume-selective three-dimensional turbo spin echo (TSE) technique with ultrasound (US) for assessing carotid artery wall structure and function. Materials and Methods A three-dimensional volume-selective TSE technique was used to image the carotid artery in 10 healthy subjects and five hypertensive subjects (each of whom were scanned three times while they received different hypertension treatments). Lumen and wall area were measured on MR images. Two-dimensional US measurements of the intima-media thickness (IMT) and lumen diameter were taken in three orientations through a single cross section. The lumen area change over the cardiac cycle was used to determine distension. For validation, a Bland-Altman analysis was used to compare the vessel wall and lumen areas measured by three-dimensional MRI volumes with those obtained by US scans. Results Agreement between the two methods was found. The mean difference in distension between US and MRI was 1.2% (±5.1%). For the wall area measurements, good agreement was shown, but there was a systematic difference due to the visualization of the adventitia by MRI. Both techniques offer an easy way to objectively measure lumen indices. MRI can provide the complete circumference over the length of a vessel, while US is flexible and relatively inexpensive. The application of US is limited, however, when subjects are poorly echogenic. A difference between hypertensive and healthy subjects was found. Conclusion There was a good agreement between MRI and the clinically established two-dimensional US method. The MRI method has the advantage of providing increased vessel coverage, which permits one to assess localized abnormalities without assuming vessel uniformity. J. Magn. Reson. Imaging 2005;21:282,289. © 2005 Wiley-Liss, Inc. [source] Do radiologists agree on the quality of computed tomography enterography?JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2009Kari Ersland Summary This study aimed to assess variation between radiologists evaluating the quality of multi-detector computed tomography enterography. For 40 consecutive examinations, three experienced radiologists independently rated the following quality variables: % length of adequately filled bowel, bowel lumen diameters, bowel wall delineation, superior mesenteric vein, and bowel wall enhancement, artefacts, and total quality. We calculated the mean difference between observers with standard deviation (SD) for continuous variables and % total agreement, exact Fleiss kappa, and P -values (McNemar's test) for categorical variables. Depending on bowel segment (duodenum distal to bulb, jejunum, ileum, terminal ileum), mean difference between observers ranged from two to 33 (SD from 11 to 32) for % length of adequately filled bowel judged subjectively, 0,2 (SD 0,3) mm for smallest bowel lumen diameter and 0,4 (SD 3,7) mm for largest bowel lumen diameter. Agreement on bowel wall delineation was 80%/kappa 0.50 in duodenum, 90%/kappa 0.57 in jejunum, 75%/kappa 0.14 in ileum and 88%/kappa 0.17 in terminal ileum, where ratings differed between observers (P < 0.04). Agreement was 65%/kappa 0.18 for bowel wall enhancement judged subjectively. For contrast enhancement measured in Hounsfield Units, mean difference between observers ranged from two to 11 (SD 12,15) in normal jejunum wall and zero to one (SD 4,5) in the superior mesenteric vein depending on observer pair. Agreement was 78%/kappa 0.12 for image artefacts. Rating of total examination quality (good/optimal versus poor/very poor) differed between observers (P < 0.01); agreement was 60%/kappa 0.41. Many subjective evaluations varied between observers. We believe that measurements of bowel lumen diameters and contrast enhancement may be preferable. [source] Intravascular low-power laser irradiation after coronary stenting: Long-term follow-upLASERS IN SURGERY AND MEDICINE, Issue 3 2001Ivan K. De Scheerder MD Abstract Background and Objective A high restenosis rate remains a limiting factor for percutaneous transluminal coronary angioplasty and stenting. The objective of this study was to evaluate the effect of intravascular red laser therapy (IRLT) on restenosis after stenting procedures in de novo lesions. Study Design/Materials and Methods A total of 68 consecutive patients were treated with IRLT in conjunction with coronary stenting procedures. Mean lesion length was 16.5,±,2.4,mm. Reference vessel diameter (RVD) and pre-minimal lumen diameter (MLD) were 2.90,±,0.15,mm and 1.12,±,0.26,mm, respectively. Results After treatment, MLD was 2.76,±,0.32 mm with no procedural complications or in-hospital adverse events. Angiographic follow-up (n,=,61) revealed restenosis in nine patients (14.7%) with rate by artery size of >,3 mm (n,=,21) 0%; 2.5,3.0 mm (n,=,28) 14.2%; and <,2.5 mm (n,=,12) 41.6%. Conclusion Intravascular red light therapy is safe, feasible, and reduces expected restenosis rate after coronary stenting. Lasers Surg. Med. 28:212,215, 2001. © 2001 Wiley-Liss, Inc. [source] Reactivity of Brain Parenchymal Arterioles after Ischemia and ReperfusionMICROCIRCULATION, Issue 6 2008MARILYN J. CIPOLLA ABSTRACT Objective: We investigated the effect of ischemia and reperfusion on the vasoactive function of penetrating brain parenchymal arterioles under pressurized conditions. Methods: Parenchymal arterioles (<50 ,m in diameter) from within the middle cerebral artery territory were dissected from male Wistar rats that were either nonischemic control (n = 16) or ischemic for one hour and reperfused for 24 hours (n = 16) by temporary filament occlusion of the middle cerebral artery. Arterioles were mounted on glass cannulas within an arteriograph chamber that allowed for the measurement of lumen diameter and control over intravascular pressure. Results: After one hour of equilibration at 10 mmHg, spontaneous myogenic tone developed in both groups of animals, constricting control arterioles from 69 ± 9 to 49 ± 11 ,m (29.5 ± 10.2%) and ischemic arterioles from 66 ± 9 to 45 ± 11 ,m (33.1 ± 14.1%); p > 0.05. Contraction to the nitric oxide synthase inhibitor nitro-L-arginine (10,4M) was significantly diminished in ischemic arterioles, constricting only 3.2 ± 3.3 vs. 15.6 ± 12.5% in control arterioles (p = 0.017). Both groups dilated to nifedipine; however, the response was significantly diminished after ischemia. The EC50 for nifedipine in control arterioles was 3.54 ± 0.11 vs. 9.90 ± 0.71 nM for ischemic arterioles (p = 0.024). Conclusions: These findings demonstrate that functional changes occur in brain parenchymal arterioles after ischemia and reperfusion, a result that may significantly influence stroke outcome by altering blood flow to an ischemic region. [source] New probe for the measurement of dynamic changes in the rectumNEUROGASTROENTEROLOGY & MOTILITY, Issue 1 2004I. S. Andersen Abstract, Conventional mano-volumetric techniques cannot measure changes in circumferential dimensions at several axial positions within a bowel segment. Our aims were to validate a new impedance planimetry probe for simultaneously measuring the cross-sectional area (CSA) at five axial positions in vitro and in vivo in 10 anesthetized pigs. The day-to-day coefficient of variation (CV) for CSA measured by the probe in cylindrical tubes of known diameter was 0.8,9.5%. The mean from actual diameter deviation ranged from 2.3 to 6.7%. In a conical tube the day-to-day CV was 2.3,8% and mean percentage deviation ,2.8 to 1.0. Interposed narrowing sections caused a total CV of 7,13%. In vivo studies revealed variations in CSA, associated with expulsion of flatus. It is concluded that impedance planimetry allows simultaneous measurement of CSA at several levels within the rectum. In vitro validity was acceptable and alterations in lumen diameter were identified in vivo. [source] Light rings in Chinese pine (Pinus tabulaeformis) in semiarid areas of north China and their palaeo-climatological potentialNEW PHYTOLOGIST, Issue 4 2006Eryuan Liang Summary ,,Light rings in conifer trees are characterized by a light-coloured, narrow latewood band of thin-walled tracheids. Most reports on light rings have been for subarctic and subalpine regions, and little is known about their occurrence in semiarid areas. ,,Dendrochronological methods were used to date the occurrence of light rings in Chinese pine (Pinus tabulaeformis) in the semiarid region of north China. The anatomical and chemical characteristics and the potential environmental controls of their formation were investigated. ,,Light rings in Chinese pine were dated to the year of their formation. The wall thickness and lumen diameter of the wood cells of light rings and reference rings were distinctly different. However, the configuration of the light-ring latewood cell walls was normal, although they were thinner than average, and their lignification had been completed normally. ,,The climate characteristics that result in light-ring formation appear to be ongoing severe drought from the previous autumn to July of the current year in conjunction with a warm summer, suggesting that light rings can be used as indicators for past drought events. [source] Noncompetitive antagonism of BIBN4096BS on CGRP-induced responses in human subcutaneous arteriesBRITISH JOURNAL OF PHARMACOLOGY, Issue 8 2004Majid Sheykhzade We investigated the antagonistic effect of 1-piperidinecarboxamide, N -[2-[[5amino-l-[[4-(4-pyridinyl)-l-piperazinyl]carbonyl]pentyl]amino]-1-[(3,5-dibromo-4-hydroxyphenyl)methyl]-2-oxoethyl]-4-(1,4-dihydro-2-oxo-3(2H)-quinazolinyl) (BIBN4096BS) on the calcitonin gene-related peptide (CGRP)-induced responses by using isometric myograph and FURA-2 technique in human subcutaneous arteries removed in association with abdominal surgery. BIBN4096BS, at the concentration of 1 pM, had no significant effect on the CGRP-induced relaxation in these vessels. At the concentration of 10 pM, BIBN4096BS had a competitive antagonistic-like behaviour characterized by parallel rightward shift in the log CGRP concentration-tension curve with no depression of the Emax. At the higher concentrations (0.1 and 1 nM), BIBN4096BS had a concentration-dependent noncompetitive antagonistic effect on the CGRP-induced responses. The efficacy and potency of CGRP was significantly greater in the smaller (lumen diameter ,200 ,m) human subcutaneous arteries compared to the larger ones. The apparent agonist equilibrium dissociation constant, KA, for CGRP1 receptors in the human subcutaneous arteries was approximately 1 nM. Analysis of the relationship between receptor occupancy and response to CGRP indicates that the receptor reserve is relatively small. Using reverse transcriptase-polymerase chain reaction (RT-PCR), the presence of mRNA sequences encoding the calcitonin receptor-like receptor, receptor activity modifying protein (RAMP1, RAMP2, RAMP3) and receptor component protein were demonstrated in human subcutaneous arteries, indicating the presence of CGRP1 -like receptor and the necessary component for the receptor activation. In conclusion, the inhibitory action of BIBN4096BS at the low concentration (10 pM) on the CGRP-tension curve (but not intracellular calcium concentration ([Ca2+]i) resembles what is seen with a reversible competitive antagonist. However, at the higher concentrations (0.1 and 1 nM), BIBN4096BS acts as a selective noncompetitive inhibitor at CGRP1 receptors in human subcutaneous arteries. British Journal of Pharmacology (2004) 143, 1066,1073. doi:10.1038/sj.bjp.0705967 [source] The AST petal dedicated bifurcation stent: First-in-human experienceCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2007John Ormiston MBChB Abstract The aim of this first-in-human study was to evaluate the feasibility and safety of the novel AST petal side-access bifurcation stent. Outcomes following percutaneous coronary intervention for bifurcations remain inferior to those of nonbifurcated lesions. Even with drug-eluting stents, restenosis occurs especially at the side-branch (SB) ostium. The petal stent uniquely deploys strut elements into the SB, supporting the ostium and carina. The primary endpoint of this 13-patient prospective registry was in-hospital major adverse cardiac events (MACE). Secondary end points included acute minimum lumen diameter (MLD) at the SB ostium, lesion success, device success, procedural success, 30-day MACE, and 4-month SB ostial MLD. The study lesion was successfully treated in 13 patients with the study stent being successfully implanted in 12. Target lesions were left anterior descending coronary artery in nine subjects, left circumflex in three, and right coronary artery in one. In-hospital MACE were limited to two non-Q-wave myocardial infarctions. In-stent main branch MLD increased from a mean of 0.63 ± 0.45 mm to 2.61 ± 0.47 mm at the index procedure and for this initial bare metal version of the stent, 4-month mean MLD measured 1.02 ± 0.42mm and there was target vessel revascularization on two patients. The feasibility of safely deploying this first-generation petal stent was demonstrated in selected patients with challenging coronary bifurcation lesions. It is a promising platform for drug delivery, with unique scaffolding of the side-branch ostium. © 2007 Wiley-Liss, Inc. [source] Long-term outcomes of bifurcation lesions after implantation of drug-eluting stents with the "mini-crush technique"CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 7 2007Alfredo R. Galassi MD, FSCAI Abstract Objectives: To evaluate clinical and angiographic long-term outcome of "the mini-crush" technique for treating bifurcation lesions. Background: Despite proven efficacy of drug-eluting stent (DES) within most lesions subsets, bifurcation lesions continue to exhibit high restenosis rate using current DES stenting technique. Methods: We report a new stenting technique which was employed in 45 consecutive patients (52 lesions) between April 2004 and July 2005 to treat true bifurcation lesions using DES in both branches. Results: Using this technique procedural success was obtained in 100% of cases, without complications and with excellent angiographic result in 96.1% and 98.1% of main vessel and side branch. Preprocedure reference vessel diameter and minimal lumen diameter (MLD) were 2.68 ± 0.48 and 0.90 ± 0.55 mm for the main branch, respectively and 2.28 ± 0.34 and 1.14 ± 0.47 mm for the side branch, respectively. Postprocedure MLD was 2.56 ± 0.39 mm for the main branch and 2.16 ± 0.29 mm for the side branch. There were no in-hospital major adverse cardiac events (MACE). At 72 days after procedure there was one case of side branch stent thrombosis (2.2%), which resulted in non Q-wave MI. Angiographic follow up was obtained in 100% of patients at 7.5 ± 1.3 months. Target lesion revascularization (TLR) was 12.2%; no death and Q-wave MI were observed; reference vessel diameter and MLD for the main branch were 2.79 ± 0.51 and 1.99 ± 0.65 mm respectively and for the side branch 2.28 ± 0.40 and 1.63 ± 0.48 mm respectively. Restenosis rate in the main branch was 12.2% while in the side branch was 2.0%. Conclusions: In-hospital outcome indicates that the mini-crush technique for bifurcation lesions with DES can be easily performed. It provides very low total MACE rate and restenosis at 8-month follow-up. These results confirmed the advantage of this specific technique to give complete coverage of the ostium of the side branch using two stents technique. © 2007 Wiley-Liss, Inc. [source] INVOLVEMENT OF PROLYLCARBOXYPEPTIDASE IN THE EFFECT OF RUTAECARPINE ON THE REGRESSION OF MESENTERIC ARTERY HYPERTROPHY IN RENOVASCULAR HYPERTENSIVE RATSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 3 2009Xu-Ping Qin SUMMARY 1Previous studies indicate that rutaecarpine blocks increases in blood pressure and inhibits vascular hypertrophy in experimentally hypertensive rats. The aim of the present study was to determine whether the effects of rutaecarpine are related to activation of prolylcarboxypeptidase (PRCP). 2Renovascular hypertensive rats (Goldblatt two-kidney, one-clip (2K1C)) were developed using male Sprague-Dawley rats. Chronic treatment with rutaecarpine (10 or 40 mg/kg per day) or losartan (20 mg/kg per day) for 4 weeks to the hypertensive rats caused a sustained dose-dependent attenuation of increases in blood pressure, increased lumen diameter and decreased media thickness, which was accompanied by a similar reduction in the media cross-sectional area : lumen area ratio in mesenteric arteries compared with untreated hypertensive rats. 3Angiotensin (Ang) II expression was significantly increased in mesenteric arteries of hypertensive rats compared with sham-operated rats. No significant differences in plasma AngII levels were observed between untreated hypertensive and sham-operated rats. Hypertensive rats treated with high-dose rutaecarpine had significantly decreased Ang II levels in both the plasma and mesenteric arteries. 4Expression of PRCP protein or kallikrein mRNA was significantly inhibited in the right kidneys and mesenteric arteries of hypertensive rats. However, expression of PRCP protein and kallikrein mRNA was significantly increased after treatment with rutaecarpine or losartan (20 mg/kg per day). 5The data suggest that the repression of increases in systolic blood pressure and reversal of mesenteric artery remodelling by rutaecarpine may be related to increased expression of PRCP in the circulation and small arteries in 2K1C hypertensive rats. [source] Fluvastatin remodels resistance arteries in genetically hypertensive rats, even in the absence of any effect on blood pressureCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 10 2002Janet M Ledingham Summary 1.,The aims of the present study were, first, to determine whether, in the genetically hypertensive (GH) rat, fluvastatin would lower blood pressure and remodel mesenteric resistance arteries (MRA) and the basilar artery and, second, to see whether treatment with a combination of fluvastatin and the angiotensin receptor antagonist valsartan would have any extra beneficial effect on blood pressure and vascular remodelling. 2.,Male GH rats had tail-cuff systolic blood pressure (SBP) monitored weekly from the age of 7 to 12 weeks. Groups (n = 12,14) were treated with fluvastatin (4 mg/kg per day), valsartan (5 mg/kg per day), both mixed in with chow, or a combination of fluvastatin 4 mg/kg per day + valsartan 5 mg/kg per day. Untreated GH and a group of normotensive Wistar (N) rats served as control groups. 3.,At 12 weeks of age, intra-arterial (i.a.) blood pressure was measured by femoral cannulation and rats were then perfused (at the SBP of the animal) with Tyrode's solution containing heparin and papaverine followed by 2.5% glutaraldehyde in Tyrode's solution; MRA and basilar arteries were embedded in Technovit. Serial sections were cut and Giemsa stained and stereological methods used to obtain media width, lumen diameter, medial cross-sectional area (CSA) and the ratio of media width to lumen diameter. Hearts were weighed to determine left ventricular (LV) mass. 4.,Fluvastatin had no effect on blood pressure or LV mass, whereas valsartan given alone or with fluvastatin significantly reduced both parameters. 5.,In MRA, fluvastatin reduced medial CSA, increased lumen size and, therefore, probably decreased vascular resistance. The media/lumen ratio was reduced to a level below that seen with the combination treatment and to below that of the N group. 6.,In the basilar artery, fluvastatin and valsartan showed similar outward remodelling of the lumen and reduction in the media/lumen ratio. The combination treatment group showed, in addition, a reduction in medial CSA and an even lower ratio than the GH group on fluvastatin or valsartan alone or the N group. 7.,Although fluvastatin has no effect on blood pressure, it does cause significant remodelling of MRA and the basilar artery. These beneficial structural changes in a peripheral resistance artery bed and in an artery involved in regulating resistance in the brain are worthy of further study. [source] Effects Of Nitric Oxide Synthase Inhibition And Low-Salt Diet On Blood Pressure And Mesenteric Resistance Artery Remodelling In Genetically Hypertensive RatsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2001Janet M Ledingham SUMMARY 1. Nitric oxide synthase (NOS)-inhibited genetically hypertensive (GH) rats on normal and low-sodium diets were additionally given valsartan or felodipine to establish whether low-Na intake would have extra beneficial effects on blood pressure and cardiovascular structure. 2. Male GH rats on normal or low-Na diets were treated with the NOS inhibitor NG -nitro- L -arginine methyl ester (L -NAME) from the age of 7 to 12 weeks and were given either valsartan (10 mg/kg per day) or felodipine (30 mg/kg per day). 3. Systolic blood pressure (SBP; tail-cuff) was measured weekly. At 12 weeks of age, mesenteric resistance arteries (MRA) were fixed by perfusion and embedded in Technovit (Heraeus Kulzer GmbH, Werheim, Germany). Serial sections were cut and stained. Stereological analysis was used to obtain MRA media width, lumen diameter, ratio of media width/lumen diameter (M/L) and medial cross-sectional area (CSA). Left ventricular (LV) mass was determined. 4. In GH L -NAME-treated rats on a normal diet, SBP was significantly reduced (P < 0.001) by valsartan and felodipine, as was LV mass (valsartan P < 0.001; felodipine P < 0.05). A low-Na diet with valsartan caused a further fall in SBP (P < 0.01) but, with felodipine, SBP increased in rats on a low-Na diet (P < 0.05). 5. Valsartan with the low-Na diet had no further effect on LV mass, but the felodipine-treated group on a low-Na diet had a lower LV mass (P < 0.05) than rats on a normal diet. 6. In MRA from the GH L -NAME + valsartan-treated group, there was hypotrophic inward remodelling; the M/L ratio was reduced (P < 0.001) compared with GH L -NAME-treated rats. The lumen was outwardly remodelled in the group on the low-Na diet. 7. The GH L -NAME + felodipine-treated group showed hypotrophic outward remodelling and a reduction in M/L ratio compared with the GH L -NAME-treated group (P < 0.001). A low-Na diet had no further effect on MRA. 8. A low-Na diet + valsartan had beneficial effects on SBP and MRA, where outward remodelling of the lumen occurred and, thus, resistance was reduced. In contrast, felodipine with a low-Na diet increased SBP, reduced LV mass and had no effect on MRA structure. Valsartan treatment with a low-Na diet confers extra benefits on blood pressure and MRA structure. [source] Assessment of bronchial wall thickness and lumen diameter in human adults using multi-detector computed tomography: comparison with theoretical modelsJOURNAL OF ANATOMY, Issue 5 2007M. Montaudon Abstract A thickened bronchial wall is the morphological substratum of most diseases of the airway. Theoretical and clinical models of bronchial morphometry have so far focused on bronchial lumen diameter, and bronchial length and angles, mainly assessed from bronchial casts. However, these models do not provide information on bronchial wall thickness. This paper reports in vivo values of cross-sectional wall area, lumen area, wall thickness and lumen diameter in ten healthy subjects as assessed by multi-detector computed tomography. A validated dedicated software package was used to measure these morphometric parameters up to the 14th bronchial generation, with respect to Weibel's model of bronchial morphometry, and up to the 12th according to Boyden's classification. Measured lumen diameters and homothety ratios were compared with theoretical values obtained from previously published studies, and no difference was found when considering dichotomic division of the bronchial tree. Mean wall area, lumen area, wall thickness and lumen diameter were then provided according to bronchial generation order, and mean homothety ratios were computed for wall area, lumen area and wall thickness as well as equations giving the mean value of each parameter for a given bronchial generation with respect to its value in generation 0 (trachea). Multi-detector computed tomography measurements of bronchial morphometric parameters may help to improve our knowledge of bronchial anatomy in vivo, our understanding of the pathophysiology of bronchial diseases and the evaluation of pharmacological effects on the bronchial wall. [source] Do radiologists agree on the quality of computed tomography enterography?JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2009Kari Ersland Summary This study aimed to assess variation between radiologists evaluating the quality of multi-detector computed tomography enterography. For 40 consecutive examinations, three experienced radiologists independently rated the following quality variables: % length of adequately filled bowel, bowel lumen diameters, bowel wall delineation, superior mesenteric vein, and bowel wall enhancement, artefacts, and total quality. We calculated the mean difference between observers with standard deviation (SD) for continuous variables and % total agreement, exact Fleiss kappa, and P -values (McNemar's test) for categorical variables. Depending on bowel segment (duodenum distal to bulb, jejunum, ileum, terminal ileum), mean difference between observers ranged from two to 33 (SD from 11 to 32) for % length of adequately filled bowel judged subjectively, 0,2 (SD 0,3) mm for smallest bowel lumen diameter and 0,4 (SD 3,7) mm for largest bowel lumen diameter. Agreement on bowel wall delineation was 80%/kappa 0.50 in duodenum, 90%/kappa 0.57 in jejunum, 75%/kappa 0.14 in ileum and 88%/kappa 0.17 in terminal ileum, where ratings differed between observers (P < 0.04). Agreement was 65%/kappa 0.18 for bowel wall enhancement judged subjectively. For contrast enhancement measured in Hounsfield Units, mean difference between observers ranged from two to 11 (SD 12,15) in normal jejunum wall and zero to one (SD 4,5) in the superior mesenteric vein depending on observer pair. Agreement was 78%/kappa 0.12 for image artefacts. Rating of total examination quality (good/optimal versus poor/very poor) differed between observers (P < 0.01); agreement was 60%/kappa 0.41. Many subjective evaluations varied between observers. We believe that measurements of bowel lumen diameters and contrast enhancement may be preferable. [source] Age-related macular degeneration: hemodynamic changesACTA OPHTHALMOLOGICA, Issue 2009CJ POURNARAS Purpose Metabolic changes of the RPE associated to the dysfunction of choriocapillaries(CC)/RPE complex may induces the AMD-related changes. Additional vascular changes in the choroid potentially have deleterious effects on the RPE. Methods Quantification of CC number and lumen diameters in cross sections and alkaline phosphatase (APase) flat-embedding technique, expressing high constitutive APase activity in choriocapillaris and choroidal veins on human RPE/Bruch's Membrane/CC complex, significantly contributed to the analysis of the choroidal vasculature. Laser Doppler flowmetry (LDF) data provided additional information on the assessment of hemodynamic changes in AMD. Results Choroidal vascular density reduction and significant vasoconstriction of the choriocapillaries, occurs during the evolution of AMD. In eyes with geographic atrophy, the RPE degenerates first while CC loss is secondary to RPE degeneration. In eyes with exudative AMD, degeneration of the CC layer occurs while RPE is still functional. LDF data indicated choroidal blood flow decrease according to age and the degree of severity of AMD; the decrease in flow preceding the formation of choroidal CNV, strongly suggest that these changes may have a role in the development of CNV. As a result of vascular dysfunction, the choroidal blood flow is dysregulated in patients with neovascular AMD. The choroidal watershed zone (WZ) courses through the fovea more often in patients suffering from AMD than in age-matched controls, particularly in the presence of CNV. Choroidal neovascularisation usually arises within these WZ. Conclusion The role of choroidal ischemia in the pathophysiology of AMD is supported by the observed choroidal microcirculation anatomical and fucntional abnormalities. [source] Effects Of Nitric Oxide Synthase Inhibition And Low-Salt Diet On Blood Pressure And Mesenteric Resistance Artery Remodelling In Genetically Hypertensive RatsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2001Janet M Ledingham SUMMARY 1. Nitric oxide synthase (NOS)-inhibited genetically hypertensive (GH) rats on normal and low-sodium diets were additionally given valsartan or felodipine to establish whether low-Na intake would have extra beneficial effects on blood pressure and cardiovascular structure. 2. Male GH rats on normal or low-Na diets were treated with the NOS inhibitor NG -nitro- L -arginine methyl ester (L -NAME) from the age of 7 to 12 weeks and were given either valsartan (10 mg/kg per day) or felodipine (30 mg/kg per day). 3. Systolic blood pressure (SBP; tail-cuff) was measured weekly. At 12 weeks of age, mesenteric resistance arteries (MRA) were fixed by perfusion and embedded in Technovit (Heraeus Kulzer GmbH, Werheim, Germany). Serial sections were cut and stained. Stereological analysis was used to obtain MRA media width, lumen diameter, ratio of media width/lumen diameter (M/L) and medial cross-sectional area (CSA). Left ventricular (LV) mass was determined. 4. In GH L -NAME-treated rats on a normal diet, SBP was significantly reduced (P < 0.001) by valsartan and felodipine, as was LV mass (valsartan P < 0.001; felodipine P < 0.05). A low-Na diet with valsartan caused a further fall in SBP (P < 0.01) but, with felodipine, SBP increased in rats on a low-Na diet (P < 0.05). 5. Valsartan with the low-Na diet had no further effect on LV mass, but the felodipine-treated group on a low-Na diet had a lower LV mass (P < 0.05) than rats on a normal diet. 6. In MRA from the GH L -NAME + valsartan-treated group, there was hypotrophic inward remodelling; the M/L ratio was reduced (P < 0.001) compared with GH L -NAME-treated rats. The lumen was outwardly remodelled in the group on the low-Na diet. 7. The GH L -NAME + felodipine-treated group showed hypotrophic outward remodelling and a reduction in M/L ratio compared with the GH L -NAME-treated group (P < 0.001). A low-Na diet had no further effect on MRA. 8. A low-Na diet + valsartan had beneficial effects on SBP and MRA, where outward remodelling of the lumen occurred and, thus, resistance was reduced. In contrast, felodipine with a low-Na diet increased SBP, reduced LV mass and had no effect on MRA structure. Valsartan treatment with a low-Na diet confers extra benefits on blood pressure and MRA structure. [source] | ||||||||||||||||||||||||||||