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1.

Background

Heterogeneity in plaque composition in human coronary artery bifurcations is associated with blood flow induced shear stress. Shear stress is generally determined by combing 3D lumen data and computational fluid dynamics (CFD). We investigated two new procedures to generate 3D lumen reconstructions of coronary artery bifurcations for shear stress computations.

Methods

We imaged 10 patients with multislice computer tomography (MSCT) and intravascular ultrasound (IVUS). The 3D reconstruction of the main branch was based on the fusion of MSCT and IVUS. The proximal part of side branch was reconstructed using IVUS data or MSCT data, resulting in two different reconstructions of the bifurcation region. The distal part of the side branch was based on MSCT data alone. The reconstructed lumen was combined with CFD to determine the shear stress. Low and high shear stress regions were defined and shear stress patterns in the bifurcation regions were investigated.

Results

The 3D coronary bifurcations were successfully generated with both reconstruction procedures. The geometrical features of the bifurcation region for the two reconstruction procedures did not reveal appreciable differences. The shear stress maps showed a qualitative agreement, and the low and high shear stress regions were similar in size and average shear stress values were identical. The low and high shear stress regions showed an overlap of approximately 75%.

Conclusion

Reconstruction of the side branch with MSCT data alone is an adequate technique to study shear stress and wall thickness in the bifurcation region. The reconstruction procedure can be applied to further investigate the effect of shear stress on atherosclerosis in coronary bifurcations.  相似文献   

2.
Sibling (cannibalism among siblings) and non-sibling cannibalism (cannibalism among non-siblings) were studied in a natural population of a lady beetle, Harmonia axyridisPallas . Of all the eggs laid (n=2269), 24.76% (n=562) were killed by sibling cannibalism and 36.10% (n=819) were killed by non-sibling cannibalism. Sibling cannibalism occurred constantly and intensively in most egg batches throughout the entire oviposition period. On the other hand, non-sibling cannibalism was more intense in the middle and late oviposition periods, and when the egg batches were close to an aphid colony. This may be due to the high density of H. axyridis larvae relative to aphid density in the middle and late oviposition periods and also the larvae searching intensively near an aphid colony.  相似文献   

3.
Background: Subarachnoid hemorrhage (SAH) is a serious condition, occurring more frequently in females than in males. SAH is mainly caused by rupture of an intracranial aneurysm, which is formed by localized dilation of the intracranial arterial vessel wall, usually at the apex of the arterial bifurcation. The female preponderance is usually explained by systemic factors (hormonal influences and intrinsic wall weakness); however, the uneven sex distribution of intracranial aneurysms suggests a possible physiologic factor—a local sex difference in the intracranial arteries.Objective: The aim of this study was to explore sex variation in the bifurcation anatomy of the middle cerebral artery (MCA) and internal carotid artery (ICA), and the subsequent hemodynamic impact.Methods: Vessel radii and bifurcation angles were measured in patients with MCA and ICA bifurcations. Data from a previously published study of 55 patients undergoing diagnostic cerebral digital subtraction angiography at Dalcross Private Hospital in Sydney, Australia, between 2002 and 2003, were available for analysis. The measurements were used to create idealized, averaged bifurcations of the MCA and ICA for females and males. Computational fluid dynamics simulations were performed to calculate hemodynamic forces in the models.Results: The vessel radii and bifurcation angles of 47 MCA and 52 ICA bifurcations in 49 patients (32 females, 17 males; mean age, 53 years; age range, 14–86 years) were measured. Statistically significant sex differences were found in vessel diameter (males larger than females; P < 0.05), but not in bifurcation angle. Computational fluid dynamics simulations revealed higher wall shear stress in the female MCA (19%) and ICA (50%) bifurcations compared with the male bifurcations.Conclusions: This study of MCA and ICA bifurcations in female and male patients suggests that sex differences in vessel size and blood flow velocity result in higher hemodynamic forces acting on the vessel wall in females. This new hypothesis may partly explain why intracranial aneurysms and SAH are more likely to occur in females than in males.  相似文献   

4.
《Bone and mineral》1990,8(2):131-143
γ-Interferon (IFN-γ) has recently been demonstrated to inhibit the ability of mononuclcar phagocytes to degrade bone particles. We have further addressed the specificity, potency and mechanism of this activity using human recombinant IFN-γ. Adherent peripheral blood mononuclear leukocytes from normal human volunteers were cultured with washed, sieved (⩽75 μm) 45Ca-labelled rat bone particles for 3 days, after which bone particle degradation (7.1 ± 1.6%, n = 11) was calculated from the fraction of45Ca released into the medium. As little as 5 U/ml IFN-γ significantly suppressed bone particle degradation and 50 U/ml was associated with consistent marked suppression (74.0 ± 3.5% inhibition, P < 0.001, n = 11). IFN-γ was not suppressive if added to cells 24 h or more after exposure to bone particles. Addition of indomethacin (10 μM) did not reverse the effect of IFN-γ, suggesting that it was not prostaglandin-mediated. In addition, 1,25(OH)2D3 (10 nM) did not remove the inhibitor, effect of IFN-γ.Contact of mononuclear phagocytes with bone particles and secretion of soluble factors from these cells have both been demonstrated to play a role in their ability to degrade bone particles. IFN-γ (50 U/ml) inhibited monocyte/macrophage interaction with another unopsonized surface, i.e., one μm fluorescent latex particles, decreasing the number of internalized particles from 12.6 ± 2.9 per cell to 5.9 ± 1.4 per cell (P < 0.01, n = 15), as measured using flow cytometry. However, binding of bone particles by the cells was not diminished by IFN-γ. Exogenous α-imerferon and human recombinant IL-1β, TNF-α, and lymphotoxin did not alter bone particle degradation. In addition, endogenous IL-1β release from human monocyte/macrophages exposed to bone particles was negligible and unaffected by IFN-γ.We conclude that IFN-γ is a potent and specific inhibitor of monocyte/macrophage-mediated bone particle degradation, and that this activity does not appear to be due to effects on the ability of monocytes to bind bone particles or to release IL-1 in response to the particles  相似文献   

5.
Summary A morphometric analysis was made of alterations in serous cell structure induced by adrenergic and cholinergic agonists. Ferret tracheal rings were exposed for 30 min in vitro to one of the following agonists: phenylephrine, terbutaline, or methacholine (all at 10–5 M). Controls were incubated similarly in medium containing no drugs or medium containing both the agonist and an excess of the appropriate antagonist (phentolamine, propranolol or atropine, all at 10–4 M).Electron microscopic observation and stereological analysis of the incubated samples revealed that the volume density of serous cell granules in controls (0.30 ± 0.02, mean ± SE, n = 4) was significantly reduced by phenylephrine (0.19 ± 0.03, n = 4) and methacholine (0.17 ± 0.01, n = 4), but not by terbutaline (0.27 ± 0.04, n = 4). The presence of antagonists in the medium prevented the observed changes (phenylephrine/phentolamine: 0.29 ± 0.03, n = 3 and methacholine/atropine: 0.33 ± 0.06, n = 3). In addition, the volume density of intracellular vacuoles in controls (0.02 ± 0.005, n = 4) was increased in response to methacholine stimulation (0.12 + 0.05, n = 4), but not in response to the other agonists. This effect was blocked by atropine (0.01 ± 0.00, n = 3).We conclude that serous-cell granules are discharged by both alpha-adrenergic and cholinergic, but not beta-adrenergic stimulation. In addition, cholinergic stimulation evokes the formation of intracellular vacuoles, a possible indication of active ion and water transport.  相似文献   

6.
To understand joint effects of logistic growth in target cells and intracellular delay on viral dynamics in vivo, we carry out two-parameter bifurcation analysis of an in-host model that describes infections of many viruses including HIV-I, HBV and HTLV-I. The bifurcation parameters are the mitosis rate r of the target cells and an intracellular delay τ in the incidence of viral infection. We describe the stability region of the chronic-infection equilibrium E* in the two-dimensional (r, τ) parameter space, as well as the global Hopf bifurcation curves as each of τ and r varies. Our analysis shows that, while both τ and r can destabilize E* and cause Hopf bifurcations, they do behave differently. The intracellular delay τ can cause Hopf bifurcations only when r is positive and sufficiently large, while r can cause Hopf bifurcations even when τ = 0. Intracellular delay τ can cause stability switches in E* while r does not.  相似文献   

7.
The purpose of this study was to determine the effects of short-term exercise cessation on lipid and lipoprotein profile and insulin sensitivity in highly trained runners (n=12; mean age 19.9 years) and power athletes (n=12; mean age 24.4 years). Following 14 days of exercise cessation, running time to exhaustion and maximal oxygen uptake decreased by 9.2% and 4.8% (P < 0.05) in the runners, while in the power athletes one repetition maximum squat and bench press did not change (P>0.05). No changes occurred in body composition. Data from a 2-h oral glucose tolerance test revealed an impairment of the glycemic state in all athletes (P<0.05). In contrast, exercise cessation did not significantly (P>0.05) alter plasma levels of cholesterol, triglycerides, and low density (LDL) and high density lipoprotein (HDL). No changes were observed in HDL2, HDL2b, and HDL3 subfractions, LDL diameter, and qualitative LDL pattern (P>0.05). These data thus suggest that despite a decrease in insulin sensitivity, short-term exercise cessation, independent of exercise mode, was insufficient to alter plasma lipid and lipoprotein profiles in well-trained athletes.  相似文献   

8.
An estimate or index of target species density is important in determining oral rabies vaccination (ORV) bait densities to control and eliminate specific rabies variants. From 1997–2011, we indexed raccoon (Procyon lotor) densities 253 times based on cumulative captures on 163 sites from Maine to Alabama, USA, near ORV zones created to prevent raccoon rabies from spreading to new areas. We conducted indexing under a common cage trapping protocol near the time of annual ORV to aid in bait density decisions. Unique raccoons (n = 8,415) accounted for 68.0% of captures (n = 12,367). We recaptured raccoons 2,669 times. We applied Schnabel and Huggins mark-recapture models on sites with ≥3 years of capture data and ≥25% recaptures as context for raccoon density indexes (RDIs). Simple linear relationships between RDIs and mark-recapture estimates supported application of our index. Raccoon density indexes ranged from 0.0–56.9 raccoons/km2. For bait density decisions, we evaluated RDIs in the following 4 raccoon density groups, which were statistically different: (0.0–5.0 [n = 70], 5.1–15.0 [n = 129], 15.1–25.0 [n = 31], and >25.0 raccoons/km2 [n = 23]). Mean RDI was positively associated with a higher percentage of developed land cover and a lower percentage of evergreen forest. Non-target species composition (excluding recaptured raccoons) accounted for 32.0% of captures. Potential bait competitors accounted for 76.5% of non-targets. The opossum (Didelphis virginiana) was the primary potential bait competitor from 27°N to 44°N latitude, north of which it was numerically replaced by the striped skunk (Mephitis mephitis). We selected the RDI approach over mark-recapture methods because of costs, geographic scope, staff availability, and the need for supplemental serologic samples. The 4 density groups provided adequate sensitivity to support bait density decisions for the current 2 bait density options. Future improvements to the method include providing random trapping locations to field personnel to prevent trap clustering and marking non-targets to better characterize bait competitors. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.  相似文献   

9.
Like many other serious acute cardiovascular and cerebrovascular events, acute myocardial infarction (AMI) shows seasonal variation, being most frequent in the winter. We sought to investigate whether age, gender, and hypertension influence this pattern. We studied 4014 (2259 male and 1755 female) consecutive patients with AMI presenting to St. Anna Hospital of Ferrara, Italy between January 1998 and December 2004. Some 1131 (28.2%) of the AMI occurred in persons <65 yrs of age, and 2883 (71.8%) in those ≥65 yrs of age. AMI was over‐represented in males (82% in the <65 yr group vs. 56.6% in the ≥65 yr group (χ2=13.99; p<0.001). Hypertension had been previously documented in 964 (24%) of the cases. There were 691 (17.2%) fatal case outcomes; fatal outcomes were significantly higher among the 3054 normotensive (n=614 or 20.1%) than the 964 hypertensive cases (n=77 or 8%; χ2=74.94, p<0.001). AMIs were most frequent in the winter (n=1076 or 26.8% of all the events) and least in the summer (n=924 or 23.0% of all the events; χ2=12.36, p=0.007). The greatest number of AMIs occurred in December (n=379 or 9.44%), and the lowest number in September (n=293 or 7.3%; χ2=11.1, p=0.001). Inferential chronobiological (Cosinor) analysis identified a significant annual pattern in AMI in those ≥65 yrs of age, with a peak between December and February—January for the total sample (p<0.005), January for the sample of males (p=0.014), February for fatal infarctions (p=0.017), and December for non‐fatal infarctions (p=0.006). No such temporal variations were detected in any of these categories in those <65 yrs of age. The annual pattern in AMI was also verified by Cosinor analysis in the following hypertensive subgroups: hypertensive males (n=552: January, p=0.014), non‐fatal infarctions in hypertensive patients (n=887: January, p=0.018), and elderly normotensives (n=1556: November, p=0.007).  相似文献   

10.
Objective: A previous epidemiological study showed an association of the insulin‐induced gene 2 (INSIG2) gene with BMI. Additionally, experimental investigations in animals and cell culture provided evidence that this gene might be involved in lipoprotein and free fatty acid (FFA) metabolism. Therefore, the aim of this study was to examine the association between the rs7566605 variant near the INSIG2 gene and BMI and to extend it to other quantitative measures of obesity, as well as parameters of lipoprotein and FFA metabolism. Methods and Procedures: We genotyped rs7566605 in a group of severely obese white patients (n = 1,026) with an average BMI of 46.0 kg/m2 and a control group (n = 818) from Utah, as well as in the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR) study from Austria, which is based on a healthy working population (n = 1,696). Results: We observed no difference in the genotype frequency of rs7566605 of INSIG2 between obese subjects and population‐based controls from Utah. Furthermore, we did not find evidence of an association with measures of body composition (BMI, waist, waist‐to‐hip ratio, percentage body fat, amount of visceral and subcutaneous abdominal adipose fat) or lipoprotein metabolism (total cholesterol, low‐density lipoprotein (LDL) and high‐density lipoprotein (HDL) cholesterol, triglycerides, and FFAs) in the Utah study population or in the independent SAPHIR study. Discussion: Our results do not support an association of the INSIG2 gene with the regulation of body weight or parameters related to lipoprotein metabolism.  相似文献   

11.
The existence of positive equilibrium solutions of the McKendrick equations for the dynamics of an age-structured population is studied as a bifurcation phenomenon using the inherent net reproductive rate n as a bifurcation parameter. The local existence and uniqueness of a branch of positive equilibria which bifurcates from the trivial (identically zero) solution at the critical value n=1 are proved by implicit function techniques under very mild smoothness conditions on the death and fertility rates as functional of age and population density. This first requires the development of a suitable linear theory. The lowest order terms in the Liapunov-Schmidt expansions are also calculated. This local analysis supplements earlier global bifurcation results of the author. The stability of both the trivial and the positive branch equilibria is studied by means of the principle of linearized stability. It is shown that in general the trivial solution losses stability as n increases through one while the stability of the branch solution is stable if and only if the bifurcation is supercritical. Thus the McKendrick equations exhibit, in the latter case, a standard exchange of stability with regard to equilibrium states as they depend on the inherent net reproductive rate. The derived lower order terms in the Liapunov-Schmidt expansions yield formulas which explicitly relate the direction of bifurcation to properties of the age-specific death and fertility rates as functionals of population density. Analytical and numerical results for some examples are given which illustrate these results.  相似文献   

12.
Outbreaks of ovine psoroptic mange in the U.K. have increased 100‐fold since its deregulation in 1992, with the highest prevalence in Wales, a region of high sheep density. A cross‐sectional, retrospective, questionnaire‐based survey of 7500 members of the association of Welsh lamb and beef farmers [Welsh Lamb and Beef Producers Ltd (WLBP)] was used to investigate the prevalence and distribution of sheep scab in this region in 2015. The survey was completed by 14.0% (n = 972) of potential respondents. Scab outbreaks were reported on 15.8% (n = 154) of farms in 2015. However, 29.0% (n = 282) of farms reported at least one scab outbreak and 2.4% (n = 23) of farms had experienced between six and 10 outbreaks in the previous 10 years. Most outbreaks occurred during September–January (83.0%, n = 150), and were clustered around Brecon (mid‐Wales) and Bangor (North Wales). Farmers who used common grazing were significantly more likely to report scab outbreaks in the previous 10 years than farmers who did not. No quarantine procedures for sheep bought in were used by 29.0% (n = 262) of farmers. Future research should be directed towards the development of localized management programmes, with a particular focus on areas of common grazing.  相似文献   

13.
Purpose: Tumor cells influence the differentiation of infiltrating macrophages. In the present study, the differentiation of macrophages in renal cell carcinomas was investigated with special regard to their possible role in tumor growth and spread. Methods: Macrophages were characterized by means of immunohistochemistry of the Ki-M1P, 25F9, MRP8, MRP14, and MRP8/14 antigens and by means of in situ hybridization of CSF-1, its c-fms-coded corresponding receptor, and human monocytic serine esterase-1 (HMSE-1) mRNA. Macrophage subgroups were quantified within central tumor tissue, the corresponding tumor host interface, and tumor-free tissue and correlated with tumor necrosis, fibrosis, and tumor stage and grade. Results: Macrophage density was much higher within tumor tissue and the tumor/host interface than in tumor-free tissue. Well-differentiated carcinomas showed a lower degree of macrophage density than less-differentiated carcinomas. Tumor-associated macrophages could be divided into an active inflammatory type (MRP14+, MRP8/14+) and into a late-phase inflammatory type (25F9+, MRP8+). Necrosis was seen in less-differentiated carcinomas and associated with a significantly increased density of MRP14+ macrophages, which, however, did not correlate with the extent of necrosis. The density of 25F9+ macrophages was correlated with an extensive connective tissue formation and an advanced tumor stage. c-fms, CSF-1, and HMSE-1 mRNA expression did not discriminate between the macrophage subgroups. Conclusions: Tumor-associated macrophages of the late-stage inflammatory type potentially support the spread of renal cell cancer. CSF-1 derived from tumor cells and macrophages acts as a monocyte attractant and induces macrophage differentiation able to modulate the extracellular matrix rather than to exert cytotoxicity. Received: 25 May 2000 / Accepted: 29 June 2000  相似文献   

14.
The objective of this study was to determine whether systemic inflammatory and oxidative stress marker concentrations correlate with pericardial and intrathoracic fat volumes. Participants of the Framingham Offspring Study (n = 1,175, 53% women, mean age 59 ± 9 years) had pericardial and intrathoracic fat volumes assessed by multidetector computed tomography (MDCT) scans, and provided fasting blood and urine samples to measure concentrations of 14 inflammatory markers: C‐reactive protein (CRP), interleukin‐6, monocyte chemoattractant protein‐1 (MCP‐1), CD40 ligand, fibrinogen, intracellular adhesion molecule‐1, lipoprotein‐associated phospholipase A2 activity and mass, myeloperoxidase, osteoprotegerin, P‐selectin, tumor necrosis factor‐α, tumor necrosis factor receptor‐2, and urinary isoprostanes. Multivariable linear regression models were used to determine the association of log‐transformed inflammatory marker concentrations with fat volumes, using fat volume as the dependent variable. Due to smaller sample sizes, models were rerun after adding urinary isoprostanes (n = 961) and tumor necrosis factor‐α (n = 813) to the marker panel. Upon backward elimination, four of the biomarkers correlated positively with each fat depot: CRP (P < 0.0001 for each fat depot), interleukin‐6 (P < 0.05 for each fat depot), MCP‐1 (P < 0.01 for each fat depot), and urinary isoprostanes (P < 0.01 for pericardial fat; P < 0.001 for intrathoracic fat). Even after adjusting for BMI, waist circumference (WC), and abdominal visceral fat, CRP (P = 0.0001) and urinary isoprostanes (P = 0.02) demonstrated significant positive associations with intrathoracic fat, but not with pericardial fat. Multiple markers of inflammation and oxidative stress correlated with pericardial and intrathoracic fat volumes, extending the known association between regional adiposity and inflammation and oxidative stress.  相似文献   

15.
Serial peels through the branch junctions of Psilophyton dawsonii were examined in an attempt to determine if “hydraulic constrictions” (i.e., a localized decrease in mean diameter of xylem elements) sensu Zimmermann (1983) had occurred during bifurcation. Based on the mean diameters of primary xylem tracheids measured acropetally and basipetally to branch junctions, evidence for xylem constrictions (= localized decrease in mean tracheid diameter) was found within the basalmost portions of four out of six minor axes examined near their attachment to major axes (anisotomous junctions). Xylem constrictions were not detected in branch junctions between axes of equal girth (isotomous junctions). Xylem constrictions were detected within the base of five out of seven junctions between fertile and main axes. The mean diameters of tracheids of the branch trace near its origin are larger both basipetally and acropetally from the constriction. There is no evidence for a localized decrease in the mean diameter of the xylem strand in the region of a constriction. Therefore, xylem constrictions are not the result of epidogenesis. Based on the production of “hydraulic constrictions” in extant plants, which serve to localize the formation of embolisms in lateral branches during water stress, it is speculated that P. dawsonii could protect the vasculature of major axes by a similar anatomical feature.  相似文献   

16.
Cerebral aneurysms form preferentially at arterial bifurcations. The vascular optimality principle (VOP) decrees that minimal energy loss across bifurcations requires optimal caliber control between radii of parent (r0) and daughter branches (r1 and r2): r0n=r1n+r2n, with n approximating three. VOP entails constant wall shear stress (WSS), an endothelial phenotype regulator. We sought to determine if caliber control is maintained in aneurysmal intracranial bifurcations. Three-dimensional rotational angiographic volumes of 159 middle cerebral artery (MCA) bifurcations (62 aneurysmal) were processed using 3D gradient edge-detection filtering, enabling threshold-insensitive radius measurement. Radius ratio (RR)=r03/(r13+r23) and estimated junction exponent (n) were compared between aneurysmal and non-aneurysmal bifurcations using Student t-test and Wilcoxon rank-sum analysis. The results show that non-aneurysmal bifurcations display optimal caliber control with mean RR of 1.05 and median n of 2.84. In contrast, aneurysmal bifurcations had significantly lower RR (0.76, p<.0001) and higher n (4.28, p<.0001). Unexpectedly, 37% of aneurysmal bifurcations revealed a daughter branch larger than its parent vessel, an absolute violation of optimality, not witnessed in non-aneurysmal bifurcations. The aneurysms originated more often off the smaller daughter (52%) vs. larger daughter branch (16%). Aneurysm size was not statistically correlated to RR or n. Aneurysmal males showed higher deviation from VOP. Non-aneurysmal MCA bifurcations contralateral to aneurysmal ones showed optimal caliber control. Aneurysmal bifurcations, in contrast to non-aneurysmal counterparts, disobey the VOP and may exhibit dysregulation in WSS-mediated caliber control. The mechanism of this focal divergence from optimality may underlie aneurysm pathogenesis and requires further study.  相似文献   

17.
A study was conducted to assess the adaptive capability of three indigenous goat breeds to heat stress. Thirty six 10 months to one-year-old female goats of Osmanabadi, Malabari and Salem Black breeds were randomly divided into six groups, OC (n = 6; Osmanabadi control), OHS (n = 6; Osmanabadi heat stress), MC (n = 6; Malabari control), MHS (n = 6; Malabari heat stress), SBC (n = 6; Salem Black control) and SBHS (n = 6; Salem Black heat stress). Among the metabolic activity controlling hormones, the breed factor significantly (P < 0.05) influenced only plasma triiodothyronine (T3). However, heat stress significantly (P < 0.05) decreased thyroid stimulating hormone (TSH) in both MHS and SHS groups while significantly (P < 0.05) decreased the plasma T3 in MHS. The rumen metabolites such as acetate, propionate, butyrate and total volatile fatty acids (TVFAs) showed significant (P < 0.05) variation for both breed and treatment effect. The Salem Black breed did not show any significant variation for most of the rumen metabolites as compared to both Osmanabadi and Malabari breeds for the heat stress treatment. The study indicated the importance of the metabolic alterations in indigenous goat breeds to cope to the seasonal rhythms. The results indicated that on comparative basis, Salem Black breed adapted better to the heat stress challenges.  相似文献   

18.
Enhanced monocyte adhesion to endothelial cells is an early event in atherogenesis. It has been shown that C‐reactive protein (CRP) plays a key role in atherogenesis. Here, we investigated the effects of CRP on monocyte‐endothelial cell adhesion and tested the hypothesis that NADPH oxidase (NOX)‐mediated oxidative stress might play a key role in CRP‐induced monocyte‐endothelial cell adhesion. Firstly, 36 patients with carotid intima‐media thickness (IMT) incrassation and 34 controls were enrolled in this study. The levels of glucose, lipids, CRP, monocyte chemotractant protein (MCP‐1), malondialdehyde (MDA), and protein carbonylation were analyzed. The results showed that carotid IMT was associated with abnormal lipid metabolism, including elevated CRP, triglycerides (TG) (P < 0.01) and decreased high density lipoprotein (HDL) level (P < 0.05). The levels of CRP and MCP‐1 in patients with carotid IMT incrassation were increased compared with the controls (P < 0.01). Moreover, patients with carotid IMT incrassation displayed enhanced MDA and protein carbonylation levels (P < 0.01), accompanied by activation and up‐regulation of NOX in monocytes (P < 0.05) compared with the controls. The monocytes isolated from five healthy donors were used for in vitro experiments. Reactive oxygen species (ROS) production and NOX expression in monocytes were examined. The results also indicated that CRP could promote the adhesion of monocyte‐endothelial cell by up‐regulation of MCP‐1 expression (P < 0.05). Importantly, NFκ B and p38 MAPK signaling pathways, which were activated by NOX‐derived ROS, were involved in CRP‐induced monocyte‐endothelial cell adhesion and up‐regulation of MCP‐1 expression. These data suggested that CRP could promote the adhesion of monocytes to endothelial cells via NOX‐mediated oxidative stress. J. Cell. Biochem. 113: 857–867, 2012. © 2011 Wiley Periodicals, Inc.  相似文献   

19.
The in vitro restoring effects of a thymic hormone preparation, TP-1, on defective monocyte and dendritic cell function in patients with head and neck squamous cell carcinoma (HNSCC) have been examined. TheN-formylmethionyl-leucyl-phenylalanine(fMLF)-induced polarization of monocytes isolated from the peripheral blood was significantly lower (a mean of 19%) than the polarization of monocytes isolated from healthy controls (a mean of 33%). After the in vitro addition of TP-1 this defective polarization was improved to the normal value of 33% polarized monocytes. The capability of dendritic cells prepared from the blood to form cellular clusters with allogeneic cells was impaired in 26/44 patients. In vitro addition of TP-1 again had restoring effects. The original defective dendritic cell clustering of 97 clusters/six microscopic fields (mean) was improved to a value of 121 clusters. The defects in monocyte polarization and clustering of dendritic cells could be ascribed to the presence in serum of a tumor-derived low-molecularmass factor low-M r factor; <25 kDa) sharing structural homology with p15E, the capsular protein of murine and feline leukemogenic retroviruses. The incubation of low-M r factor from the serum of HNSCC patients with healthy donor monocytes resulted in a significantly higher inhibition of fMLF-induced monocyte polarization than did incubation with control low-M r factor (a mean of 42 versus 16% inhibition). This suppressive effect of patient low-M r factor was abrogated with a mixture of two monoclonal antibodies against p15E as well as with TP-1. The observations here reported on the in vitro effects of TP-1 on depressed monocyte and dendritic cell function in HNSCC have provided one of the rationales for a TP-1 therapeutic pilot trial recently started in HNSCC patients.  相似文献   

20.
Ulrike Nolte 《Hydrobiologia》1991,222(3):197-211
Chironomid communities of mosses in a small upland stream in central Germany were highly dynamic across the year with respect to their abundance, biomass and dominant taxa. During 1988 semi-submersed mosses near a main spring and those occurring some 700 m downstream were compared with permanently submersed mosses in immediate vicinity of the downstream site. All the chironomids sampled were conspicuously small, with nearly 98% being less than 5 mm in length. A total of 65 chironomid species from 26 genera were found, with a higher diversity occurring near the source and a change in dominant taxa along the upper stream section. The mean abundance in permanently submersed mosses (250 larvae/10 cm2, n = 125) was about five times higher than in semi-submersed mosses. The maximum value of 830 larvae/10 cm2 (n = 1) is the highest chironomid density ever reported, which is explained by the sampling method used. The mean standing crop was also highest in permanently submersed mosses (1.5 mg AFDW/10 cm2 (n = 125)), even though the highest individual value was recorded in semi-submersed mosses near the spring (10.4 mg AFDW/10 cm2). The evidence suggested that the dominance of chironomid taxa depended mainly on the location of the moss along the stream, whereas abundance and biomass were determined mainly by constancy in the ambient discharge as well as the factors influenced by this (e.g. temperature, detritus deposition). A trend was seen towards a seasonal succession among the chironomid taxa colonizing lotic mosses.  相似文献   

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