Explore the vast range of titles available.

Functional photoacoustic imaging of the placenta could provide an innovative tool to diagnose preeclampsia, monitor fetal growth restriction, and determine the developmental impacts of gestational diabetes. However, transabdominal photoacoustic imaging is limited in imaging depth due to the tissue’s scattering and absorption of light. The aim of this paper was to investigate the impact of geometry and wavelength on transabdominal light delivery. Our methods included the development of a multilayer model of the abdominal tissue and simulation of the light propagation using Monte Carlo methods. A bifurcated light source with varying incident angle of light, distance between light beams, and beam area was simulated to analyze the effect of light delivery geometry on the fluence distribution at depth. The impact of wavelength and the effects of variable thicknesses of adipose tissue and muscle were also studied. Our results showed that the beam area plays a major role in improving the delivery of light to deep tissue, in comparison to light incidence angle or distance between the bifurcated fibers. Longer wavelengths, with incident fluence at the maximum permissible exposure limit, also increases fluence within deeper tissue. We validated our simulations using a commercially available light delivery system and ex vivo human placental tissue. Additionally, we compared our optimized light delivery to a commercially available light delivery system, and conclude that our optimized geometry could improve imaging depth more than 1.6×, bringing the imaging depth to within the needed range for transabdominal imaging of the human placenta.

Preeclampsia is a hypertensive disorder of pregnancy that affects multiple organs, including the heart, increasing long-term cardiovascular risks for both the mother and offspring. While the G protein-coupled estrogen receptor (GPER) has cardioprotective effects, its role in pregnancy-associated cardiac dysfunction, particularly in chronic hypertension, remains unclear, given the significant physiological adaptations that occur during pregnancy, including hormonal fluctuations and hemodynamic changes. This study investigated whether LNS8801, a selective and orally bioavailable GPER agonist, could improve cardiac function in virgin and pregnant Dahl salt-sensitive (SS/Jr) rats, a model of chronic hypertension exacerbated by pregnancy. Female Dahl SS/Jr rats, both virgin and pregnant, were randomized into four groups: Virgin + Vehicle, Virgin + LNS8801, Pregnant + Vehicle, and Pregnant + LNS8801. LNS8801 (800 µg/kg/day, given orally) was administered in pregnant rats from gestational day (GD) 9 to 20 and for an equivalent period in virgin controls. Cardiac function was assessed via echocardiography, including speckle-tracking strain analysis and conventional systolic and diastolic parameters. Mean arterial pressure and proteinuria were also measured. LNS8801 significantly improved cardiac function in pregnant Dahl SS/Jr rats, enhancing global longitudinal, circumferential, and radial strain, as well as increasing systolic function. Additionally, LNS8801 enhanced diastolic function, improving left ventricular compliance (E/A ratio) and early mitral annular velocity (e'), while reducing left ventricular filling pressures (E/e' ratio). In contrast, LNS8801 had no significant effects on cardiac function and blood pressure in virgin Dahl SS/Jr rats, suggesting that pregnancy-related adaptations may enhance GPER-mediated cardioprotection. LNS8801 treatment significantly reduced proteinuria in both virgin and pregnant rats, indicating a pregnancy-independent renal protective effect. This study highlights the importance of pregnancy-specific adaptations in shaping the cardiovascular effects of GPER activation. While LNS8801 demonstrated cardioprotective and antihypertensive benefits in pregnant Dahl SS/Jr rats, its effects were absent in virgin animals, underscoring the influence of the physiological and hormonal environment on GPER-mediated responses. These findings provide a foundation for further exploration of GPER as a therapeutic target for pregnancy-associated cardiovascular dysfunction and preeclampsia, reinforcing the need for pregnancy-specific approaches in drug development.

Background: Preeclampsia is a potentially devastating disorder of hypertension in pregnancy for which there is currently no definitive treatment short of delivery. The bufadienolide, marinobufagenin (MBG), an inhibitor of Na + /K + ATPase, has been found to be elevated in extracellular fluid volume-expanded hypertensive patients, a condition similar to preeclampsia. Thus, these studies sought to examine the role of MBG in our rat model of preeclampsia. Methods and Results: Pregnant female rats were injected intraperitoneally with deoxycorticosterone acetate (DOCA) and given 0.9% saline as drinking water for the duration of their pregnancy. Urinary MBG was measured using a DELFIA immunoassay. Blood pressure was measured via the tail-cuff method. Injections of anti-MBG antibody were given intraperitoneally or intravenously to hypertensive pregnant rats. MBG was given intraperitoneally to pregnant rats. Uterine arterioles were dissected free and their diameters were measured before and after perfusion of MBG, ouabain, or digoxin. MBG was found to be elevated in the pregnant + DOCA + saline (PDS) rats compared to normal pregnant animals. In addition, when PDS rats were injected with anti-MBG antibody, there was a subsequent reduction in blood pressure. Administration of MBG in normal pregnant rats caused an elevation in blood pressure equivalent to the PDS model. Also, uterine vessel measurements showed an increased vasoconstrictive reactivity to MBG in the PDS animals vs. the normal pregnant controls; while no changes were observed with perfusion of digoxin or ouabain at the same concentration. Conclusion: These results suggest a relationship between MBG and a syndrome in rats resembling preeclampsia. Armed with these promising results, it would seem logical to further examine the role of MBG in human preeclampsia.