Search

Normal pregnancy is associated with reduced blood pressure (BP) and decreased pressor response to vasoconstrictors, even though the renin-angiotensin system is upregulated. Angiotensin II (ANG II) activates both angiotensin type 1 receptors ([AT.sub.1]Rs) and angiotensin type 2 receptors ([AT.sub.2]Rs). Although the role of the [AT.sub.1]R in vascular contraction is well documented, the role of the [AT.sub.2]R in vascular relaxation, particularly during pregnancy, is less clear. It was hypothesized that the decreased BP and vasoconstriction during pregnancy was, at least in part, due to changes in [AT.sub.2]R amount, distribution, and/or postreceptor mechanisms of vascular relaxation. To test this hypothesis, systolic BP was measured in virgin and pregnant (day 19) Sprague-Dawley rats. Isometric contraction/ relaxation was measured in isolated aortic rings, and nitric oxide (NO) production was measured using 4-amino-5-methylamino-2',7'-difluorescein fluorescence. [AT.sub.1]R and [AT.sub.2]R mRNA expression and protein amount were measured in tissue homogenates using real-time RT-PCR and Western blots, and their local distribution was visualized in cryosections using immunohistochemistry and immunofluorescence. BP was lower in pregnant than virgin rats. Phenylephrine (Phe) caused concentration-dependent contraction that was reduced in the aorta of pregnant compared with virgin rats. Treatment with the [AT.sub.2]R antagonist PD-123319 caused greater enhancement of Phe contraction, and the [AT.sub.2]R agonist CGP-42112A caused greater relaxation of Phe contraction in the aorta of pregnant than virgin rats. ANG II plus the [AT.sub.1]R blocker losartan induced greater NO production in the aorta of pregnant than virgin rats. RT-PCR revealed increased mRNA expression of vascular endothelial NO synthase (eNOS), little change in [AT.sub.1]Rs, and increased [AT.sub.2]Rs in pregnant compared with virgin rats. Western blots revealed an increased protein amount of activated phospho-eNOS, little change in [AT.sub.1]Rs, and increased [AT.sub.2]Rs in pregnant compared with virgin rats. Immunohistochemistry and immunofluorescence analysis in aortic sections of virgin rats revealed abundant [AT.sub.1]R staining in tunica media that largely colocalized with actin in vascular smooth muscle and less [AT.sub.2]Rs mainly in the tunica intima and endothelium. In pregnant rats, [AT.sub.1]R staining in the smooth muscle layer and adventitia was reduced, and endothelial [AT.sub.2]R staining was enhanced. These data suggest an enhanced [AT.sub.2]R-mediated vascular relaxation pathway involving increased expression/activity of endothelial [AT.sub.2]Rs and increased postreceptor activated phospho-eNOS, which may contribute to the decreased BP during pregnancy. endothelium; nitric oxide; nitric oxide synthase; vascular smooth muscle; blood pressure

Background: Heart failure (HF) involves myocardial fibrosis and dysregulated angiogenesis. Objective: We explored whether biomarkers of fibrosis and angiogenesis correlate with HF severity. Methods: Biomarkers of fibrosis [procollagen types I and III (PIP and P3NP), carboxyterminal-telopeptide of type I collagen (ICTP), matrix metalloproteases (MMP2 and MMP9), tissue inhibitor of MMP1 (TIMP1)]; and angiogenesis [placental growth factor (PGF), vascular endothelial growth factor (VEGF), soluble Fms-like tyrosine kinase-1 (sFlt1)] were measured in 52 HF patients and 19 controls. Results: P3NP, ICTP, MMP2, TIMP1, PGF, and sFlt1 levels were elevated in HF, while PIP/ICTP, PGF/sFlt1, and VEGF/sFlt1 ratios were reduced. PIP/ICTP, MMP-9/TIMP1, and VEGF/sFlt1 ratios were lowest among patients with severe HF. Conclusions: Severe HF is associated with collagen breakdown and reduced angiogenesis. A multimarker approach may guide therapeutic targeting of fibrosis and angiogenesis in HF. [ABSTRACT FROM PUBLISHER]

: Right ventricular (RV) failure is a major cause of mortality in acute or chronic lung disease and left heart failure. The objective of this study was to demonstrate a percutaneous approach to study biventricular hemodynamics in murine models of primary and secondary RV pressure overload (RVPO) and further explore biventricular expression of two key proteins that regulate cardiac remodeling: calcineurin and transforming growth factor beta 1 (TGFβ1). Methods: Adult, male mice underwent constriction of the pulmonary artery or thoracic aorta as models of primary and secondary RVPO, respectively. Conductance catheterization was performed followed by tissue analysis for changes in myocyte hypertrophy and fibrosis. Results: Both primary and secondary RVPO decreased biventricular stroke work however RV instantaneous peak pressure (dP/dtmax) and end-systolic elastance (Ees) were preserved in both groups compared to controls. In contrast, left ventricular (LV) dP/dtmax and LV-Ees were unchanged by primary, but reduced in the secondary RVPO group. The ratio of RV:LV ventriculo-arterial coupling was increased in primary and reduced in secondary RVPO. Primary and secondary RVPO increased RV mass, while LV mass decreased in primary and increased in the secondary RVPO groups. RV fibrosis and hypertrophy were increased in both groups, while LV fibrosis and hypertrophy were increased in secondary RVPO only. RV calcineurin expression was increased in both groups, while LV expression increased in secondary RVPO only. Biventricular TGFβ1 expression was increased in both groups. Conclusion: These data identify distinct effects of primary and secondary RVPO on biventricular structure, function, and expression of key remodeling pathways. [ABSTRACT FROM AUTHOR]

Background: Human studies of therapeutic angiogenesis, stem-cell, and progenitor-cell therapy have failed to demonstrate consistent clinical benefit. Recent studies have shown that heparin increases circulating levels of anti-angiogenic peptides. Given the widely prevalent use of heparin in percutaneous and surgical procedures including those performed as part of studies examining the benefit of therapeutic angiogenesis and cell-based therapy, we compared the effects of unfractionated heparin (UFH) on angiogenic peptides with those of bivalirudin, a relatively newer anticoagulant whose effects on angiogenic peptides have not been studied. Methodology/Principal Findings: We measured soluble fms-like tyrosine kinase-1 (sFLT1), placental growth factor (PlGF), vascular endothelial growth factor (VEGF), and soluble Endoglin (sEng) serum levels by enzyme linked immunosorbent assays (ELISA) in 16 patients undergoing elective percutaneous coronary intervention. Compared to baseline values, sFLT1 and PlGF levels increased by 2629±313% and 253±54%, respectively, within 30 minutes of UFH therapy (p<0.01 for both; n = 8). VEGF levels decreased by 93.2±5% in patients treated with UFH (p<0.01 versus baseline). No change in sEng levels were observed after UFH therapy. No changes in sFLT1, PlGF, VEGF, or sEng levels were observed in any patients receiving bivalirudin (n = 8). To further explore the direct effect of anticoagulation on circulating angiogenic peptides, adult, male wild-type mice received venous injections of clinically dosed UFH or bivalirudin. Compared to saline controls, sFLT1 and PlGF levels increased by >500% (p<0.01, for both) and VEGF levels increased by 221±101% (p<0.05) 30 minutes after UFH treatment. Bivalirudin had no effect on peptide levels. To study the cellular origin of peptides after anticoagulant therapy, human coronary endothelial cells were treated with UFH and demonstrated increased sFLT1 and PlGF levels (ANOVA p<0.01 for both) with reduced VEGF levels (ANOVA p<0.05). Bivalirudin had no effect on peptide levels in vitro. Conclusions/Significance: Circulating levels of sFLT1, PlGF, and VEGF are significantly altered by UFH, while bivalirudin therapy has no effect. These findings may have significant implications for clinical studies of therapeutic angiogenesis, stemcell and progenitor-cell therapy. [ABSTRACT FROM AUTHOR]

Objective: In postmenopausal women, differentiating high-grade cervical intraepithelial neoplasia (CIN 2,3) from atrophic uterine cervical squamous epithelium histologically may pose a diagnostic challenge. Recent studies have indicated the value of using a combination of Ki-67, cyclin E, and p16 immunohistochemical analysis in recognizing CIN 2,3. In this study, we compared the staining features of Ki-67, cyclin E, and p16 in cervix specimens from postmenopausal women to distinguish CIN 2,3 from atrophy.Methods: Twenty-six formalin-fixed paraffin-embedded archival cervical specimens (4 biopsy, 8 laser cone, and 14 total hysterectomy samples) were selected from 25 women 50 to 80 years of age (mean = 64 years). Cases included CIN 2,3 (n = 10), atrophy (n = 9), and coexistent CIN 2,3 and atrophy (n = 6). Slides were stained with monoclonal antibodies to Ki-67, cyclin E, and p16 using the avidin-biotin-peroxidase method. Strength of staining was graded as 1+ to 3+. Pattern of staining was described as diffuse, patchy, or scattered. Ki-67 staining restricted to the basal/parabasal zone was scored as negative.Results: All CIN 2,3 cases demonstrated variable positivity for Ki-67, cyclin E, and p16. Most CIN 2,3 cases showed strong p16 (81.3%) and Ki-67 (75.0%) reactivity, while only 31.3% of them showed strong cyclin E activity. Some CIN 2,3 cases demonstrated strong p16 but weak Ki-61 and cyclin E reactivity. All atrophic epithelia were negative for p16, cyclin E, and Ki-67. In coexistent CIN 2,3 and atrophy cases, the three-antibody panel clearly demarcated the transition from benign to neoplastic epithelia.Conclusion: P16 is the most valuable marker followed by Ki-67 for differentiating CIN 2,3. While cyclin E appears to add limited value on these two markers. Therefore, although the three-antibody immunohistochemical panel (p16, Ki-67, and cyclin E) can be a valuable adjunct to routine hematoxylin-eosin staining, it is also possible to use the two-antibody panel (p16 and Ki-67) to effectively distinguish CIN 2,3 from atrophy in postmenopausal women. [ABSTRACT FROM AUTHOR]

The soil-water characteristic curve (SWCC) is the basis for obtaining the hydraulic conductivity parameters of a soil as well as for using soil water and heat transport models. At present, the curve can be obtained by two methods: by direct measurement and by empirical formula. Direct measurement is both difficult and time-consuming. By contrast, fitting the SWCC with a suitable empirical formula is stable and convenient. The van Genuchten (VG) model has the advantage of universal applicability due to its use of a statistical aperture distribution model for estimating hydraulic conductivity. This study selected the Mu Us Bottomland as a study area. Data on the water content and water potential of undisturbed soil from this site were obtained with a Ku-pF instrument and a self-designed soil column experiment with temperature settings of 13 °C, 18 °C, 23 °C, 27 °C, and 30 °C. The variation of four main parameters in the VG model with temperature was analyzed based on thermodynamic theory and considering the effect of temperature on soil capillary pressure via its effects on surface tension and contact angle. A prediction model for the soil-water characteristic curve of the Mu Us Bottomland was then constructed, and its applicability was further analyzed. The temperature dependence of the SWCC demonstrated here provides an important scientific basis for agricultural production, farmland water conservancy, and the design of soil and water conservation engineering projects. [ABSTRACT FROM AUTHOR]