Search

Background/Objectives: Sulodexide (SDX) is a drug known for restoring the glycocalyx, thereby offering endothelial protection and regulating permeability. Additionally, it has antithrombotic and anti-inflammatory properties and has shown arterial vasodilatory effects. Endothelial cells play a crucial role in maintaining homeostasis, with their dysfunction being a key contributor to loss in vasodilatory response, especially in arterial pathologies. The aim of this study was to investigate the effects of SDX on stimulated vascular tonus in human arterial samples and to assess the function of the endothelial layer as a source of nitric oxide (NO). Methods: A total of 16 internal mammary artery remnants from coronary artery bypass graft surgeries were dissected into endothelium-intact and endothelium-denuded groups (n = 8 each). The arterial rings were equilibrated under tension, with their basal tonus recorded before and after phenylephrine stimulation. SDX's impact on arterial contraction was assessed through cumulative dose–response curves. NO synthase inhibitor (Nω-nitro-L-arginine methyl ester) was used to assess SDX's vasodilatory effect over the NO pathway. Results: SDX application resulted in concentration-dependent vasorelaxation in both endothelium-intact and endothelium-denuded groups at certain doses. However, the inhibitory effect of SDX was more pronounced in endothelium-intact rings at higher doses compared to endothelium-denuded rings (p < 0.05). Similar inhibition of contraction curves was achieved for both endothelium-intact and endothelium-denuded rings after L-NAME pre-incubation, suggesting a necessity for NO-related endothelial pathways. Conclusions: SDX exerts a concentration-dependent inhibition on arterial contraction, emphasizing the critical role of an intact endothelium and NO-mediated pathways in this process. This underscores SDX's potential in treating endothelial dysfunction-related pathologies. [ABSTRACT FROM AUTHOR]

Simple Summary: During lactation, the mammary glands of ewes are prone to infections caused by numerous pathogens. Consequently, mastitis and other udder abnormalities frequently occur. Unfortunately, udder inflammation, whether clinical or subclinical, it poses a significant barrier to livestock profitability by reducing milk production, decreasing milk quality, and suppressing ewes' reproductive performance. The cost of subclinical mastitis often is greater than that of clinical mastitis. Thus, such conditions must be treated during the dry period, which is important for mammary gland repair and recovery. Moreover, an early diagnosis is crucial for effective treatment. Ultrasonography is a useful tool that is employed in the detection of echotextural and hemodynamic changes. During recent decades, there has been an increasing scientific interest in the contributions of B-mode and Doppler to the determination of physiological and pathological conditions occurring in mammary glands, which cannot be detected during a physical examination. Therefore, the aim of the present study was to investigate the alterations in ewes' udders' echotexture and blood flow during the end of lactation, the stages of dry period, and the first days of the postpartum period. A further objective was to investigate the hemodynamic and echotextural differentiations between ewes having healthy udders and ewes having subclinical mastitis. The objective of the current study was to investigate the echotextural and hemodynamic changes of ewes entering the dry period with or without subclinical mastitis. B-mode and color Doppler ultrasonography were applied to 12 Chios ewes (6 with healthy udders (group A) and 6 with subclinical mastitis (group B)) before the dry period, during the dry period (the involution phase, steady state, and transition phase), and postpartum. The color Doppler of the mammary arteries was used to evaluate them according to the pulsatility index (PI), resistive index (RI), end-diastolic velocity (EDV), time-averaged maximum velocity (TAMV), blood flow volume (BFV), and artery diameter (D). Udder parenchyma images, analyzed by Echovet v2.0, were used to evaluate the mean value (MV), standard deviation (SD), gradient mean value (GMV), gradient variance (GV), contrast (Con), entropy (Ent), gray value distribution (GVD), run length distribution (RunLD), and long run emphasis (LRunEm). In the involution phase, the PI was higher in group B compared to group A (p ≤ 0.05). The PI and RI were higher postpartum, whereas the EDV, TAVM, and D were higher in the transition phase (p ≤ 0.05). Neither the period nor the ewe group affected the MV, SD, GMV, GV, Con, and GVD values (p ≤ 0.05). In the steady state, the LRunEm was higher in group B, but postpartum, it was higher in group A (p ≤ 0.05). In conclusion, B-mode and Doppler can reveal differences (i) between healthy ewes and ewes with subclinical mastitis and (ii) among the different periods studied. Further research is needed on the blood flow and echotexture indices of the udders of ewes with unilateral subclinical mastitis. [ABSTRACT FROM AUTHOR]

We describe a case of severe peripheral vascular disease in a patient presenting for coronary artery bypass grafting (CABG). There was an occlusion of the abdominal aorta with collaterals from the internal mammary arteries (IMA) and inferior epigastric arteries (IEA) supplying the lower limb. Off-pump CABG was carried out without harvesting the IMA. In presence of concomitant severe peripheral vascular disease, lower limb blood flow should be evaluated with Doppler ultrasound, and in selected cases, computed tomography angiogram should be performed to rule out IMA-IEA collaterals dependent limb perfusion. [ABSTRACT FROM AUTHOR]

Objective: To analyze two techniques of papaverine application, topical spray on the harvested left internal mammary artery (LIMA) and perivascular injection, to find out their ability to improve LIMA flow. Methods: Forty patients were randomized into two groups. In Group 1, papaverine was sprayed on the harvested pedunculated LIMA. In Group 2, papaverine was delivered into the perivascular plane. Drug dosage was the same for both groups. LIMA flow was measured 20 minutes after applying papaverine. Blood flow was recorded for 20 seconds and flow per minute was calculated. The systemic mean pressures were maintained at 70 mmHg during blood collection. The data collected was statistically evaluated and interpreted. Results: The LIMA blood flow before papaverine application in the Group 1 was 51.9±13.40 ml/min and in Group 2 it was 55.1±15.70 ml/min. Statistically, LIMA flows were identical in both groups before papaverine application. The LIMA blood flow, post papaverine application, in Group 1 was 87.20±13.46 ml/min and in Group 2 it was 104.7±20.19 ml/min. The Group 2 flows were statistically higher than Group 1 flows. Conclusion: Papaverine delivery to LIMA by the perivascular injection method provided statistically significant higher flows when compared to the topical spray method. Hence, the perivascular delivery of papaverine is more efficient than the spray method in improving LIMA blood flow. [ABSTRACT FROM AUTHOR]

Mechanical stimuli are key to understanding disease progression and clinically observed differences in failure rates between arterial and venous grafts following coronary artery bypass graft surgery. We quantify biologically relevant mechanical stimuli, not available from standard imaging, in patient-specific simulations incorporating non-invasive clinical data. We couple CFD with closed-loop circulatory physiology models to quantify biologically relevant indices, including wall shear, oscillatory shear, and wall strain. We account for vessel-specific material properties in simulating vessel wall deformation. Wall shear was significantly lower ( p = 0.014*) and atheroprone area significantly higher ( p = 0.040*) in venous compared to arterial grafts. Wall strain in venous grafts was significantly lower ( p = 0.003*) than in arterial grafts while no significant difference was observed in oscillatory shear index. Simulations demonstrate significant differences in mechanical stimuli acting on venous vs. arterial grafts, in line with clinically observed graft failure rates, offering a promising avenue for stratifying patients at risk for graft failure. [ABSTRACT FROM AUTHOR]

It is now half a century since the start of coronary bypass graft surgery (CABG) with the first percutaneous coronary intervention (PCI) following just over a decade later. The relative merits of PCI vs. CABG for stable coronary artery disease (stable-CAD) have continued to be debated ever since and have been the focus of around 20 randomized trials and numerous registry studies, systematic reviews, and meta-analyses. The aim of this review is to identify areas of agreement, disagreement, and uncertainties in the role of PCI and CABG in patients with stable-CAD. [ABSTRACT FROM AUTHOR]

OBJECTIVES To evaluate early outcomes of bilateral internal mammary artery (BIMA) compared with single IMA (SIMA) in patients who underwent isolated coronary artery bypass grafting (CABG). METHODS Patients who received isolated CABG with SIMA or BIMA were retrospectively reviewed using the Japan Adult Cardiovascular Surgery Database from 210 institutions for 2008 and 2009. We performed a one-to-one matched analysis on the basis of estimated propensity scores for patients receiving either SIMA or BIMA and obtained two cohorts with 3851 patients in each group balanced for baseline characteristics out of 8136 SIMA and 4093 BIMA patients. We compared procedures actually performed, early outcomes including 30-day operative mortality and details of postoperative complications between the groups using Pearson's chi-square test, with P < 0.05 being statistically significant. RESULTS Preoperative profiles in both groups included 20% females and 50% diabetes mellitus patients with a mean age of 67 years. Off-pump CABG was similar in both groups, being performed 75% of the time, with the mean number of anastomosis being 3.1 and 3.4 in the SIMA and BIMA groups, respectively (P < 0.0001). Thirty-day operative mortality was 1.2% in both groups, and the overall incidence of postoperative complications also was similar, although deep sternal infection was more frequent with BIMA (1.3 of SIMA and 2.3% of BIMA patients; P = 0.0001), while prolonged ventilation and renal failure were more frequent with SIMA (P < 0.05). CONCLUSIONS The use of BIMA did not affect either short-term survival as postoperative mortality was low in both groups, or overall morbidity despite higher incidence of deep sternal infection. [ABSTRACT FROM AUTHOR]

We report a case with an acquired fistula between the left internal mammary artery and the pulmonary artery following coronary bypass surgery treated with a bovine pericardium covered stent. We also reviewed similar cases reported previously. [ABSTRACT FROM AUTHOR]

Daily estradiol-17β (E2β) increases basal uterine blood flow (UBF) and enhances acute E2β-mediated increases in UBF in ovariectomized nonpregnant ewes. The acute E2β-mediated rise in UBF involves vascular smooth muscle (VSM) large-conductance Ca2+-activated K+ channels (BKCa). BKCa consist of pore-forming α-subunits and regulatory β1-subunits that modulate channel function and E2β responsiveness. It is unclear whether E2β also alters subunit expression and thus channel density and/or function, thereby contributing to the rise in basal UBF and enhanced UBF responses that follow daily E2β. Therefore, we examined BKCa subunit expression by using reverse transcription-PCR and immunoblot analysis of arterial VSM from reproductive and nonreproductive tissues and myometrium from ovariectomized nonpregnant ewes after daily E2β (1 µg/kg iv) or vehicle without or with acute E2β (1 µg/kg). Tissue distribution was determined by immunohistochemistry. Acute E2β did not alter α- or β1-subunit expression in any tissue (P > 0.1). Daily E2β also did not affect α-subunit mRNA or protein in any tissue (P > 0.1) or mesenteric arterial VSM β1-subunit. However, daily E2β increased uterine and mammary arterial VSM β1-subunit mRNA by 32% and 83% (P < 0.05), uterine VSM protein by 30%, and myometrial β1-subunit mRNA and protein by 74% (P ⩽ 0.005). Immunostaining of uterine arteries, myometrium, and intramyometrial arteries paralleled immunoblot analyses for both subunits. Although BKCa density is unaffected by daily and acute E2β, daily E2β increases β1-subunit in proximal and distal uterine arterial VSM. Thus prolonged E2β exposure may alter BKCa function, estrogen responsiveness, and basal vascular tone and reactivity in reproductive arteries by modifying α:β1 stoichiometry. [ABSTRACT FROM AUTHOR]

Objective: To determine the tissue content and endothelin-receptor characteristics of endothelin-1 in the radial artery in relation to the internal mammary artery.Design: Endothelin-1 content was quantified in the radial artery and the internal mammary artery. Both arteries were exposed to endothelin-1 and agonists of the endothelin A and B receptors.Results: The highest level of endothelin-1 was found in the radial artery. Endothelin-1 contracted both arteries. The contraction was sensitive to endothelinA-receptor agonism and enhanced in both arteries by inhibition of prostacyclin and nitric oxide formation. In the internal mammary artery the endothelinB-receptor agonist caused an endothelinA-receptor sensitive contraction augmented by inhibition of nitric oxide and prostacyclin. However, in the radial artery this contraction was only observed in the presence of inhibition of nitric oxide and prostaglandin.Conclusion: The highest endothelin-1 content was found in the radial artery. The functional effects of endothelin-1 in the radial artery were similar to that in the internal mammary artery, mediated by predominantly endothelinA-receptor activation causing vasoconstriction. Selective endothelinA-receptor blockade may prove beneficial in preventing graft spasm in the radial as well as the internal mammary artery. [ABSTRACT FROM AUTHOR]

Objective: To determine the mechanism(s) whereby daily and acute estradiol-17β (E2β) exposure modifies endothelium-derived nitric oxide synthase (eNOS) and vascular smooth muscle (VSM) neuronal nitric oxide synthase (nNOS) in reproductive and nonreproductive arteries and to localize NOS isoform expression within the vessel wall. Methods: Oophorectomized nonpregnant ewes received E2β (1 μg/kg per day) or no E2β for 5–6 days or acute E2β (1 μg/kg) on day 6–7 with or without daily E2β. Uterine, mammary, mesenteric, and femoral arteries were collected at completion of each study, adventitia were removed, and samples were frozen and stored at −80C. After separating endothelium and VSM, NOS isoform mRNA was measured using reverse transcription-polymerase chain reaction. VSM nNOS protein was determined by Western analysis. Results: Basal eNOS and nNOS mRNA was greatest (P <.02) in reproductive artery endothelium and VSM, respectively. Daily E2β was required for maximum uterine vascular responses to acute E2β and was associated with increased reproductive artery endothelial eNOS mRNA (> 1.5-fold, P <.02) and uterine VSM nNOS mRNA (> 2.5-fold, P <.003) and protein (21%, P <.05). Acute E2β in the presence and absence of daily E2β also increased uterine eNOS 68% and 28% (P =.01), respectively within 90 minutes but did not affect VSM nNOS. Mammary eNOS increased 71% only after E2β withdrawal; VSM nNOS was unchanged. Neither NOS isoform was altered in nonreproductive arteries by daily or acute E2β. Conclusion: Basal eNOS and nNOS isoform expression is greatest in arteries from reproductive tissues, and isoform responses to E2β are cell specific and transcriptionally regulated. Furthermore, optimal uterine vascular responses to acute E2β exposure require daily E2β exposure that enhances basal NOS expression and abundance. [ABSTRACT FROM AUTHOR]

Objective:To determine the mechanism(s) whereby daily and acute estradiol-17β (E2β) exposure modifies endothelium-derived nitric oxide synthase (eNOS) and vascular smooth muscle (VSM) neuronal nitric oxide synthase (nNOS) in reproductive and nonreproductive arteries and to localize NOS isoform expression within the vessel wall.Methods:Oophorectomized nonpregnant ewes received E2β (1 μg/kg per day) or no E2β for 5-6 days or acute E2β (1 μg/kg) on day 6-7 with or without daily E2β. Uterine, mammary, mesenteric, and femoral arteries were collected at completion of each study, adventitia were removed, and samples were frozen and stored at -80C. After separating endothelium and VSM, NOS isoform mRNA was measured using reverse transcription-polymerase chain reaction. VSM nNOS protein was determined by Western analysis.Results:Basal eNOS and nNOS mRNA was greatest (P < .02) in reproductive artery endothelium and VSM, respectively. Daily E2β was required for maximum uterine vascular responses to acute E2β and was associated with increased reproductive artery endothelial eNOS mRNA (> 1.5-fold, P < .02) and uterine VSM nNOS mRNA (> 2.5-fold, P < .003) and protein (21%, P < .05). Acute E2β in the presence and absence of daily E2β also increased uterine eNOS 68% and 28% (P = .01), respectively within 90 minutes but did not affect VSM nNOS. Mammary eNOS increased 71% only after E2β withdrawal; VSM nNOS was unchanged. Neither NOS isoform was altered in nonreproductive arteries by daily or acute E2β.Conclusion:Basal eNOS and nNOS isoform expression is greatest in arteries from reproductive tissues, and isoform responses to E2β are cell specific and transcriptionally regulated. Furthermore, optimal uterine vascular responses to acute E2β exposure require daily E2β exposure that enhances basal NOS expression and abundance. [ABSTRACT FROM PUBLISHER]

The objectives of the present study were: (i) to evaluate a novel procedure for catheterization of the mammary artery; (ii) to measure amino acid, glucose and calcium arteriovenous differences in lactating sows; and (iii) to evaluate the use of different markers in estimating mammary plasma flow by the Fick principle. Five multiparous sows were fitted with two catheters, in the cranial epigastric artery and anterior mammary vein. Catheterization of the cranial epigastric artery was carried out with a new surgical technique. Implanted catheters remained functional until day 15 (in two animals), day 21 (one animal) and day 27 (one animal), whereas in one case this technique failed. Sampling of arterial and venous blood took place on days 9, 15, 21 and 27 of lactation. Mean extraction rates±SEM (percent) were 31.2±3.1 arginine (Arg), 16.4±2.5 glutamine (Gln), 27.2±5.7 threonine (Thr), 8.3±2.6 glycine (Gly), 12.4±2.7 alanine (Ala), 20.2±3.4 tyrosine (Tyr), 18.1±2.8 proline (Pro), 28.2±6.2 methionine (Met), 18.5±2.2 valine (Val), 26.4±3.1 phenylalanine (Phe), 30.2±3.1 isoleucine (Ile), 41.4±3.4 leucine (Leu), 32.2±4.0 lysine (Lys) and 20.0±2.76 glucose. There was a relatively high abundance of lysine in milk compared with the amount extracted from plasma. This suggests lysine to be limiting in the present experimental situation, which was probably due to a low feed intake only providing 31.4 g Lys day[sup -1] on average. Mean mammary plasma flow (litres plasma day[sup -1]), evaluated by use of Lys, Met and calcium as markers in the metabolic Fick principle, amounted to 7869±989 Lys, 6391±2139 Met and 4059±747 calcium. The large difference in the results implies that there is a need for other markers to measure the mammary plasma flow or novel methods based on other principles to measure mammary plasma flow, which is an important factor in quantitative studies of daily mammary uptake of nutrients. [ABSTRACT FROM AUTHOR]