Capillary Area Research Articles

Evaluation of Placentome Morphology in the Last Two Periods of Pregnancy in Hair Goats (Capra aegagrus hircus).

This study was carried out on pregnant uteruses obtained from healthy Hair goats (Capra aegagrus hircus). A total of thirteen pregnant uteruses, six second and seven third trimesters, were used. Morphometrically, placentome numbers, lengths, widths and depths were measured. Randomly selected placentomes from the second and third trimesters were stained with the triple staining method. Caruncular and cotyledonary areas, capillary numbers and areas were measured using Qupath v0.5.0 software. The Minitab (version 21.4.1) was used for statistical analysis. While no statistical difference was observed in the number of placentomes between trimesters (p > 0.05), placentome length, width and depth were higher in the third trimester compared to the second trimester (p < 0.001). No difference was observed in the number of caruncular and cotyledonary capillaries in the second trimester. In the second trimester, the caruncular capillary area was higher than the cotyledonary capillary area (p < 0.05). Both caruncular and cotyledonary capillary area parameters were higher in the third trimester than in the second trimester (p < 0.001). In the third trimester, the caruncular capillary area was higher than the cotyledonary capillary area (p < 0.001). The number of caruncular capillaries and cotyledonary capillaries was statistically significantly higher in the third trimester compared to the second trimester. In addition, the number of cotyledonary capillaries was higher than that of caruncular capillaries in the third trimester (p < 0.001). A positive and significant correlation was found between the day of pregnancy and the number of placentomes in the second trimester (p < 0.05). No correlation was observed between the day of pregnancy and the number of placentomes in the third trimester. Vascular area density showed a faster development in foetal tissue than in maternal tissue. Placentome size and angiogenesis increased with the progression of pregnancy.

Repeated treatment with VEGF receptor inhibitors induces phenotypic changes in endothelial cells and pericytes in the rat retina

Abnormal ocular angiogenesis is a major cause of visual impairment and vision loss in neovascularization-related diseases. Currently, anti-vascular endothelial growth factor (VEGF) drugs are used to treat ocular neovascularization, but repeated injections are needed to maintain their therapeutic effects. However, repeated injection of anti-VEGF drugs may affect the retinal blood vessel phenotype and diminish therapeutic effects. In this study, we aimed to investigate the phenotypic changes in endothelial cells and pericytes caused by the repeated interruption of the VEGF receptor signaling pathway in neonatal rats. KRN633 (10 mg/kg), a VEGF receptor tyrosine kinase inhibitor, was subcutaneously administered on postnatal day (P)-7 and P8 (first round), P14 and P15 (second round), and P21 and P22 (third round). The rat eyes were collected on P7, P9, P14, P16, P21, P23, P28, and P35. Using retinal flat-mount specimens stained with specific markers for vascular endothelial cells, basement membranes, and pericytes, the arteriolar tortuosity, capillary area density, and distribution of pericytes were evaluated. Significant loss of capillaries was observed the day after the first round of KRN633 treatment, after which aggressive angiogenesis occurred, leading to the formation of tortuous arterioles. Rats that completed second and third rounds of KRN633 treatment showed more severe abnormalities in the retinal vasculature than those that only completed first round treatment. Repeated treatment with KRN633 decreased the anti-angiogenic effects but increased the immunoreactivity of α-smooth muscle actin in the pericytes on veins and capillaries. α-Smooth muscle actin expression was inversely correlated to anti-angiogenic effects. Overall, these results revealed that repeated interruption of VEGF receptor signaling pathway altered the phenotypes of endothelial cells and pericytes and induced anti-VEGF drug resistance. Therefore, careful follow-up is necessary when using anti-VEGF drugs to treat abnormal angiogenesis-associated ocular diseases.

Peripheral Superficial Retina Vascular Density and Area of Radial Peripapillary Capillaries Changes in Myopic Individuals: A Wide-Field OCT Angiography Study.

Using swept-source optical coherence tomography (SS-OCT) to explore the effect of high myopia on superficial retina vascular density (SVD) of the peripheral region and the area of radial peripapillary capillaries (RPCs). In this cross-sectional study, a total of 91 volunteers (34 male subjects and 57 female subjects) were recruited and 34 individuals in the high myopic group (group A) and 57 individuals in the low myopic group (group B). Using the wide-field OCT-angiography (OCTA; 24 × 20 mm, 120 degrees angular field) compared the peripheral SVD and the area of RPC between the two groups and investigated its correlation with ocular axial length and diopter. Peripheral SVD of group B around the supratemporal (SVD1), supranasal (SVD2), infratemporal (SVD3), and infranasal (SVD4) directions were significantly higher than those of group A (all P < 0.05). The RPC area of group B around the supranasal (RPC2) and infranasal (RPC4) were significantly larger than that of group A (all P < 0.01). Ocular axial length and diopter were significantly correlated with SVD2 and SVD4 (all P < 0.05), and they also have a significant correlation with the supratemporal (RPC1), RPC2, and RPC4 (all P < 0.05). Peripheral SVD was decreased and the RPC area was mainly reduced on the nasal side in the high myopic group. Peripheral SVD and area of RPC are significantly correlated with ocular axial length and diopter. The wide-field OCTA can be used for new detection of myopia's impact on the retinal peripheral SVD and area of peripapillary RPC, offering new insights into the progression of myopia.

The Role of Widefield Optical Coherence Tomography Angiography in Assessing the Severity of Diabetic Retinopathy.

Physicians need an accurate understanding of diabetic retinopathy (DR) severity to optimally manage patients. The aim of this prospective study is to correlate the severity of macular and peripheral retinal vascular abnormalities seen on widefield (WF) optical coherence tomography angiography (OCTA) with DR grading based on WF fundus photography. The study included 150 eyes from 82 patients with treatment-naïve DR. All patients were imaged with WF fundus photography and swept-source WF OCTA. Quantitative and qualitative analyses of the foveal avascular zone (FAZ) size and shape, and measurement of capillary nonperfusion (CNP) areas, were performed from the OCTA images. The mixed-effects model was used to compare the DR grading from WF photography with the vascular changes seen on WF-OCTA, and Bonferroni correction was applied to the gradings. The mean [± standard deviation (SD)] age of patients was 55.5 (± 9.4) years. The WF-OCTA showed that an increasing size of the FAZ (from 0.442 (± 0.059) µm to 0.933 (± 0.086) µm) correlated with increasing severity of the DR (as determined with WF photography). The deep capillary plexus, FAZ size, and CNP areas in eyes with proliferative diabetic retinopathy (PDR) differed from those with mild nonproliferative diabetic retinopathy (NPDR) (p < 0.001). Most eyes with severe nonproliferative DR were found to have CNP in four quadrants [superficial capillary plexus (SCP) 60%, deep capillary plexus (DCP) 50%]. The WF-OCTA detected subtle neovascularization of the disc (NVD) in 7 eyes (10%) and neovascularization elsewhere (NVE) in 13 eyes (18%) that had been diagnosed with only moderate NPDR on WF photography. FAZ and CNP areas as measured by WF-OCTA correlate with DR severity. WF-OCTA can also detect subtle NVE and NVD that cannot be seen with fundus photography.

Inducible deletion of endothelial cell Efnb2 delays capillary regeneration and attenuates myofibre reinnervation following myotoxin injury in mice.

Acute injury of skeletal muscle disrupts myofibres, microvessels and motor innervation. Myofibre regeneration is well characterized, however its relationship with the regeneration of microvessels and motor nerves is undefined. Endothelial cell (EC) ephrin-B2 (Efnb2) is required for angiogenesis during embryonic development and promotes neurovascular regeneration in the adult. We hypothesized that, following acute injury to skeletal muscle, loss of EC Efnb2 would impair microvascular regeneration and the recovery of neuromuscular junction (NMJ) integrity. Mice (aged 3-6months) were bred for EC-specific conditional knockout (CKO) of Efnb2 following tamoxifen injection with non-injected CKO mice as controls (CON). The gluteus maximus, tibialis anterior or extensor digitorum longus muscle was then injured with local injection of BaCl2. Intravascular staining with wheat germ agglutinin revealed diminished capillary area in the gluteus maximus of CKO vs. CON at 5days post-injury (dpi); both recovered to uninjured (0dpi) level by 10dpi. At 0dpi, tibialis anterior isometric force of CKO was less than CON. At 10dpi, isometric force was reduced by half in both groups. During intermittent contractions (75Hz, 330mss-1, 120s), isometric force fell during indirect (sciatic nerve) stimulation whereas force was maintained during direct (electrical field) stimulation of myofibres. Neuromuscular transmission failure correlated with perturbed presynaptic (terminal Schwann cells) and postsynaptic (nicotinic acetylcholine receptors) NMJ morphology in CKO. Resident satellite cell number on extensor digitorum longus myofibres did not differ between groups. Following acute injury of skeletal muscle, loss of Efnb2 in ECs delays capillary regeneration and attenuates recovery of NMJ structure and function. KEY POINTS: The relationship between microvascular regeneration and motor nerve regeneration following skeletal muscle injury is undefined. Expression of Efnb2 in endothelial cells (ECs) is essential to vascular development and promotes neurovascular regeneration in the adult. To test the hypothesis that EfnB2 in ECs is required for microvascular regeneration and myofibre reinnervation, we induced conditional knockout of Efnb2 in ECs of mice. Acute injury was then induced by BaCl2 injection into gluteus maximus, tibialis anterior or extensor digitorum longus (EDL) muscle. Capillary regeneration was reduced at 5days post-injury (dpi) in gluteus maximus of conditional knockout vs. controls; at 10dpi, neither differed from uninjured. Nerve stimulation revealed neuromuscular transmission failure in tibialis anterior with perturbed neuromuscular junction structure. Resident satellite cell number on EDL myofibres did not differ between groups. Conditional knockout of EC Efnb2 delays capillary regeneration and attenuates recovery of neuromuscular junction structure and function.

Capillary contact points determine beta cell polarity, control secretion and are disrupted in the db/db mouse model of diabetes

Aims/hypothesisAlmost all beta cells contact one capillary and insulin granule fusion is targeted to this region. However, there are reports of beta cells contacting more than one capillary. We therefore set out to determine the proportion of beta cells with multiple contacts and the impact of this on cell structure and function.MethodsWe used pancreatic slices in mice and humans to better maintain cell and islet structure than in isolated islets. Cell structure was assayed using immunofluorescence and 3D confocal microscopy. Live-cell two-photon microscopy was used to map granule fusion events in response to glucose stimulation.ResultsWe found that 36% and 22% of beta cells in islets from mice and humans, respectively, have separate contact with two capillaries. These contacts establish a distinct form of cell polarity with multiple basal regions. Both capillary contact points are enriched in presynaptic scaffold proteins, and both are a target for insulin granule fusion. Cells with two capillary contact points have a greater capillary contact area and secrete more, with analysis showing that, independent of the number of contact points, increased contact area is correlated with increased granule fusion. Using db/db mice as a model for type 2 diabetes, we observed changes in islet capillary organisation that significantly reduced total islet capillary surface area, and reduced area of capillary contact in single beta cells.Conclusions/interpretationBeta cells that contact two capillaries are a significant subpopulation of beta cells within the islet. They have a distinct form of cell polarity and both contact points are specialised for secretion. The larger capillary contact area of cells with two contact points is correlated with increased secretion. In the db/db mouse, changes in capillary structure impact beta cell capillary contact, implying that this is a new factor contributing to disease progression.Graphical

#1257 Complement system is overactivated in patients with IgA nephropathy after COVID-19

Abstract Background and Aims Since the coronavirus disease of 2019 (COVID-19) pandemic swept across the world, the flare of immune-mediated disease following SARS-CoV-2 infection has emerged rapidly. IgA nephropathy (IgAN), which has been confirmed as a complement mediated autoimmune disease, is also one of the common glomerulonephritis associated with COVID-19. Here, we aim to investigate the clinical and immunological characteristics of patients with IgAN after COVID-19. Method From December 2022 to April 2023, 33 patients with renal biopsy-proven IgAN (Group CoV) at Beijing Anzhen hospital who had experienced COVID-19 before renal biopsy were enrolled. Meanwhile, 44 patients with IgAN (Group non-CoV) diagnosed from December 2018 to April 2019 (the same period in the previous year, with no COVID-19) were enrolled as control. Plasma FHR-5, MBL, C5a, soluble C5b-9, serum Gd-IgA1 and IgA immune complex were detected by enzyme-linked immunosorbent assay. Glomerular staining for FHR-5, C3c, MAC and Gd-IgA1 were detected by immunofluorescence. SARS-CoV-2 nucleocapsid was detected by immunohistochemistry. Clinicopathological and immunological features between the two groups were analyzed. Results The median time between onset of COVID-19 symptoms and the time of renal biopsy was 12 (6, 18) weeks, ranging from 1 to 26 weeks. SARS-CoV-2 nucleocapsid antigen expression in the renal tubular epithelial cells were observed in 11/33 (33.3%) patients. Compared with Group non-CoV, the level of eGFR was significantly lower in Group CoV[67.30 (52.94, 96.43) ml/min per 1.73 m2 vs. 101.04 (74.35, 120.98) ml/min per 1.73 m2, p = 0.010]. Histologically, compared with Group non-CoV, Group CoV presented with more percentages of segmental glomerulosclerosis/adhesion (p = 0.003) and less percentages of mesangial hypercellularity (p = 0.017). The level of plasma level of C5a [16.45 (10.48, 22.07) ng/ml vs. 3.68 (2.70, 4.47) ng/ml], soluble C5b-9 [614.43 (481.66, 770.02) ng/ml vs. 358.08 (304.83, 471.77) ng/ml], FHR5 [4.01 (3.51, 4.48) ug/ml vs. 2.73 (2.25, 3.21) ug/ml]were all significantly higher in Group CoV compared with Group non-CoV, respectively (p &amp;lt; 0.001). Although the plasma level of MBL showed no difference in Group CoV and Group non-CoV, the proportion of high levels of MBL in Group CoV was higher than in Group non-CoV (p = 0.025). Compared with Group non-CoV, the intensity of glomerular MAC deposition was much stronger in Group CoV. There were no significant differences in serum levels of IgA, Gd-IgA1, IgA immune complex between two Groups. However, a greater intensity of Gd-IgA1 deposition in glomerular mesangial and capillary areas has been exhibited in Group CoV than those in Group non-CoV (p = 0.005). Conclusion For IgAN after COVID-19, mucosal immune responses to SARS-CoV-2 infection may result in the overactivation of systemic and renal local complement system, which is the first hit, and increased glomerular deposition of Gd-IgA1 is the second hit. We think that these two hits may lead to renal dysfunction and promote renal progression in IgAN patients. It is crucial to emphasize the necessity for long term follow-up in these patients of IgAN after COVID-19. Additionally, we propose that inhibitors targeting the mediators of complement activation might be a promising therapy for these IgAN patients after SARS-CoV-2 infection.

Pathomorphological characteristics of heat stress in the experiment.

The purpose of this research was to explore some morphological, physiological, and biochemical changes in female and fetal Wistar rats under heat stress. The experiment involved 30 animals, including two experimental groups (pregnant and nonpregnant females) kept under heat stress at 32°C and one control group consisting of healthy individuals kept in standard vivarium conditions. After dissection, fixation, dehydration, and primary processing, tissue samples were embedded in a mixture of paraffin and lanolin to obtain material for sections. Sections were made using a freezing and angular microtome and stained with hematoxylin and fuchsine solutions. Changes in morphology were assessed by microscopy using a Leitz DIAPLAN system. As a result of heat stress, an increase in linear cell size, capillary network area, and adrenal mass was observed; adipocytes lost lipid vacuoles; prismatic thyroid cells were replaced by flat cells; hypothyroidism; an increase in the number of osteocyte lacunae; and increased osteoclast activity in bone tissue; interstitial and intracellular oedema and caryopycnosis of ventricular cardiomyocytes; reduction in the diameter of skeletal muscle fibers and replacement of tissue with collagen fibers; water loss in the structure of myofibrils; destructive local changes, hyperchromatosis and caryopycnosis of the hippocampus. The data obtained allows predicting the possible consequences of prolonged overheating of tissues of other vertebrates and the human body.

SVPath: A Deep Learning Tool for Analysis of Stria Vascularis from Histology Slides

IntroductionThe stria vascularis (SV) may have a significant role in various otologic pathologies. Currently, researchers manually segment and analyze the stria vascularis to measure structural atrophy. Our group developed a tool, SVPath, that uses deep learning to extract and analyze the stria vascularis and its associated capillary bed from whole temporal bone histopathology slides (TBS).MethodsThis study used an internal dataset of 203 digitized hematoxylin and eosin-stained sections from a normal macaque ear and a separate external validation set of 10 sections from another normal macaque ear. SVPath employed deep learning methods YOLOv8 and nnUnet to detect and segment the SV features from TBS, respectively. The results from this process were analyzed with the SV Analysis Tool (SVAT) to measure SV capillaries and features related to SV morphology, including width, area, and cell count. Once the model was developed, both YOLOv8 and nnUnet were validated on external and internal datasets.ResultsYOLOv8 implementation achieved over 90% accuracy for cochlea and SV detection. nnUnet SV segmentation achieved a DICE score of 0.84–0.95; the capillary bed DICE score was 0.75–0.88. SVAT was applied to compare both the ears used in the study. There was no statistical difference in SV width, SV area, and average area of capillary between the two ears. There was a statistical difference between the two ears for the cell count per SV.ConclusionThe proposed method accurately and efficiently analyzes the SV from temporal histopathology bone slides, creating a platform for researchers to understand the function of the SV further.

Occult retinal neovascularization following intravitreal bevacizumab and laser treatment for retinopathy of prematurity

BackgroundWe present a patient with retinopathy of prematurity (ROP) who developed worsening plus disease after complete regression of stage 3 ROP. The use of fundus fluorescein angiography (FFA) aided the visualization of occult neovascularization that caused the disease progression.Case presentationThe patient was at high risk for ROP due to low birth weight of 690 g and gestational age of 25 weeks. After the diagnosis of stage 3 ROP in zone I without plus disease, she was treated initially with bilateral intravitreal bevacizumab (IVB) and followed by laser photocoagulation 5 weeks later. Despite the resolution of ROP stage, the plus disease worsened. Neither systemic risk factors nor skip laser areas were observed. Hence, FFA was performed and subsequently identified occult neovascularization with active leakage. Additional IVB and laser treatment in the capillary dropout area inside vascularized retina were added. The plus disease improved but mild arteriolar tortuosity persisted.ConclusionsWorsening of plus disease after completion of laser ablation and IVB with complete regression of stage 3 ROP is rare. Systemic risk factors such as continuous oxygen therapy and cardiovascular disease should be ruled out. FFA aided in identifying occult neovascularization and prompted further treatment.

WHY HAPPENS A PROGRESSIVE DECREASE OF BLOOD PRESSURE AFTER RENAL DENERVATION

Objective: Long-term follow-up data from the SYMPLICITY 3 trial (Bhatt et al, Lancet, 2022) and the Global Symplicty Register data (Mahfoud et al, JACC, 2020) show a further decrease in BP over time up to 3 years post procedure. Yet these observations lack a mechanistic explanation. A decrease in vascular resistance could possibly explain the observed phenomenon. Scanning Laser Doppler Flowmetry (SLDF) allows the non-invasive assessment of vascular resistance and capillary density by using the retinal vasculature as a mirror of the systemic circulation. Design and method: Retinal parameters were assessed using SLDF together with office and 24-hour ambulatory BP before and 6 as well as 12 months after renal denervation in 63 patients with treatment resistant hypertension (TRH) (NCT01687725). SLDF allows the assessment of retinal capillary flow (RCF), pulsed retinal capillary flow (systolic retinal capillary flow – diastolic retinal capillary flow) (pRCF), retinal vascular resistance, capillary area (CapA) and intercapillary distance (ICD). Results: Mean age of the study cohort was 60±11 years, mean BMI 30.6±4.9 kg/m2. Patients took 5.8 antihypertensive medications on average. There was a significant reduction of systolic and diastolic 24-hour ambulatory as well office BP 6 as well as 12 months after RDN (table 1). There was no significant reduction in the number of antihypertensive medications taken between baseline and 12 months after RDN (5.8vs.5.7 antihypertensive pills, p=0.159). Retinal vascular resistance was reduced 6 months after RDN (table 1), pRCF was reduced 6 as well as 12 months after RDN and capillary density improved 12 months after RDN. Conclusions: In high-risk patients with TRH endovascular RDN improved vascular resistance and reversed capillary rarefaction in the retinal circulation, a prognostic marker of further end-organ damage. The reduction of pRCF indicates a decrease of shear stress on the vascular wall by the pulsed blood flow. Increment of capillary density was observed not already 6 months, but only 12 months after RDN. We conclude that, improvement of capillary rarefaction happens slowly after RDN and requires long-term effective BP control and, that reduction in vascular resistance might explain the prolonged BP reduction after RDN.

The vascular footprint in cardiac homeostasis and hypertensive heart disease-A link between apelin receptor, vascular endothelial growth factor, and neuronal nitric oxide synthase.

Recent studies have suggested a connection between disturbances of the apelin system and various cardiac pathologies, including hypertension, heart failure, and atherosclerosis. Vascular endothelial growth factor is crucial for cardiac homeostasis as a critical molecule in cardiac angiogenesis. Neuronal nitric oxide synthase is an essential enzyme producing nitric oxide, a key regulator of vascular tone. The present study aims to shed light upon the complex interactions between these three vital signaling molecules and examine their changes with the progression of hypertensive heart disease. We used two groups of spontaneously hypertensive rats and age-matched Wistar rats as controls. The expression of the apelin receptor, vascular endothelial growth factor, and neuronal nitric oxide synthase were assessed immunohistochemically. We used capillary density and cross-sectional area of the cardiomyocytes as quantitative parameters of cardiac hypertrophy. Immunoreactivity of the molecules was more potent in both ventricles of spontaneously hypertensive rats compared with age-matched controls. However, capillary density was lower in both ventricles of the two age groups of spontaneously hypertensive rats compared with controls, and the difference was statistically significant. In addition, the cross-sectional area of the cardiomyocytes was higher in both ventricles of the two age groups of spontaneously hypertensive rats compared with controls, and the difference was statistically significant. Our study suggests a potential link between the apelin receptor, vascular endothelial growth factor, and neuronal nitric oxide synthase in cardiac homeostasis and the hypertensive myocardium. Nevertheless, further research is required to better comprehend these interactions and their potential therapeutic implications.

Changes in foveal avascular zone parameters in individuals with prediabetes compared to normoglycemic controls: a systematic review and meta-analysis.

To investigate changes in foveal avascular zone parameters in individuals with prediabetes compared to normoglycemic controls. PUBMED, Scopus and Cochrane Library were searched for published articles comparing the foveal avascular zone between prediabetic individuals and normoglycemic controls as assessed by optical coherence tomography angiography (OCTA). Standardised Mean Difference (SMD) with 95% confidence interval (CI) was computed for the comparison. A total of seven studies were included in our analysis, 6 provided data for the superficial capillary plexus from 345 eyes of individuals with prediabetes and 347 eyes of controls and 4 provided data on the deep capillary plexus from 285 eyes from individuals with prediabetes and 325 eyes of controls. Foveal avascular zone (FAZ) area in the superficial capillary plexus was enlarged in individuals with prediabetes compared to normoglycemiccontrols (SMD = 0.23, 95% CI = 0.03-0.44, p = 0.03, I2 = 27%, 6 studies). There was no statistically significant change in the deep capillary plexus FAZ area between the two groups (SMD = 1.14, 95% CI = -0.06-2.34, p = 0.06, I2 = 97%, 4 studies). FAZ area in the superficial capillary plexus was larger in individuals diagnosed with prediabetes compared to normoglycemic controls. This finding suggests that prediabetes could induce retinal microvascular changes before the onset of clinical diabetes. More original studies are needed to validate the results of the current meta-analysis.

Influence of Maternal Nutrition and One-Carbon Metabolites Supplementation during Early Pregnancy on Bovine Fetal Small Intestine Vascularity and Cell Proliferation.

To investigate the effects of nutrient restriction and one-carbon metabolite (OCM) supplementation (folate, vitamin B12, methionine, and choline) on fetal small intestine weight, vascularity, and cell proliferation, 29 (n = 7 ± 1 per treatment) crossbred Angus beef heifers (436 ± 42 kg) were estrous synchronized and conceived by artificial insemination with female sexed semen from a single sire. Then, they were allotted randomly to one of four treatments in a 2 × 2 factorial arrangement with the main factors of nutritional plane [control (CON) vs. restricted feed intake (RES)] and OCM supplementation [without OCM (-OCM) or with OCM (+OCM)]. Heifers receiving the CON level of intake were fed to target an average daily gain of 0.45 kg/day, which would allow them to reach 80% of mature BW by calving. Heifers receiving the RES level of intake were fed to lose 0.23 kg/heifer daily, which mimics observed production responses in heifers that experience a diet and environment change during early gestation. Targeted heifer gain and OCM treatments were administered from d 0 to 63 of gestation, and then all heifers were fed a common diet targeting 0.45 kg/d gain until d 161 of gestation, when heifers were slaughtered, and fetal jejunum was collected. Gain had no effect (p = 0.17) on the fetal small intestinal weight. However, OCM treatments (p = 0.02) displayed less weight compared to the -OCM groups. Capillary area density was increased in fetal jejunal villi of RES - OCM (p = 0.02). Vascular endothelial growth factor receptor 2 (VEGFR2) positivity ratio tended to be greater (p = 0.08) in villi and was less in the crypts (p = 0.02) of the RES + OCM group. Cell proliferation decreased (p = 0.02) in villi and crypts of fetal jejunal tissue from heifers fed the RES + OCM treatment compared with all groups and CON - OCM, respectively. Spatial cell density increased in RES - OCM compared with CON + OCM (p = 0.05). Combined, these data show OCM supplementation can increase expression of VEGFR2 in jejunal villi, which will promote maintenance of the microvascular beds, while at the same time decreasing small intestine weight and crypt cell proliferation.

Связь парацентральной острой срединной макулопатии и гипертонической болезни

Purpose. To study changes in retinal microcirculation and the prevalence of chronic paracentral acute middle maculopathy (PAMM) lesions in patients with mild hypertension. Participants. Twenty-seven patients (21 males and 6 females 50.3 ± 6.3 years) with mild hypertension without cardiovascular risk and 24 healthy subjects (15 males and 9 females, 46.3 ± 13.0 years) were included. Methods. The foveal avascular zone (FAZ) area, vessel density of superficial and deep capillary plexus were assessed using optical coherence tomography (OCT) angiography. The presence of chronic PAMM lesions was evaluated by the revision of cross-sectional OCT images of 6-mm volume scans. A chronic or resolved PAMM lesion was defined as inner nuclear layer thinning with outer plexiform layer disruption. Results. There was no difference between hypertensive and healthy group in baseline characteristics, vessel density of superficial capillary plexus, vessel density of deep capillary plexus and FAZ area. Chronic PAMM lesions were found in 88.9 % hypertensive patients and in 16.7 % healthy individuals. The odds ratio for the presence of chronic PAMM lesions in mild hypertension was 40.0 (p &lt; 0.001). Conclusion. Chronic PAMM lesions are highly prevalent in hypertensive patients and may represent the earliest changes in retinal microcirculation in mild hypertension, before changes in OCT angiography parameters have become apparent. Keywords: paracentral acute middle maculopathy, hypertension, optical coherence tomography

Condition of the cardiovascular system in Wistar rats with experimental renal dysfunction

The aim: to evaluate functional and structural changes in blood vessels and myocardium in Wistar rats at different stages of the formation of experimental kidney dysfunction.Materials and Methods. Four groups of animals were studied. The first two groups consisted of rats subjected to 5/6 nephrectomy (NE). The period after NE is 2 or 4 months. The third and fourth groups included sham-operated (SO) animals of a similar observation period. After the end of the experiment, blood pressure was measured in rats, the left ventricular mass index (LVMI) was calculated, a biochemical blood test, histological, immunohistochemical and electron microscopic examination of the myocardium were performed, and the contractile activity of the portal vein was recorded for a period of 2 months (in vitro).Results. 2 months after NE, an increase in blood pressure, LVMI, and a decrease in the autorhythmic contractile activity of the portal vein were detected in rats. At the histological level, thickening of cardiomyocytes and arterial vessel walls and the presence of perivascular fibrosis were noted. After 4 months, in rats with NE, the increase in blood pressure, cardiomyocyte hypertrophy and perivascular fibrosis progressed. The thickness of cardiomyocytes was 14.1±3.11 μm, which was significantly greater than in the group with NE for 2 months (12.5±1.5 μm; p=0.008). At this period of observation, electron microscopic examination revealed deintegration of myofibrils, disruption of myofibril stacking and z-disk structure, and changes in the shape of mitochondria. 2 months after NE, an increase in the area of open capillaries was detected in rats (1902.8±202.9 μm²) compared to the corresponding LO animals (730.4±58.2 μm²; p=0.000). As renal dysfunction develops, the capillary area tends to increase (2139.1±396.5 μm²; p =0.120).Conclusion. In Wistar rats with renal dysfunction, changes were detected not only in the level of blood pressure, but also in the functional activity of the intravenous fluid, as well as in the structural components of the myocardium – cardiomyocytes, stroma and blood vessels. The increase in myocardial mass at the histological level was manifested by a significant increase in the thickness of cardiomyocytes, the volume of connective tissue, and the thickness of the wall of arterial vessels, reaching a maximum value at a longer period after NE.

Association between albuminuria and retinal microvascular parameters measured with swept-source optical coherence tomography angiography in patients with diabetic retinopathy.

To evaluate the relationship between urine albumin excretion (UAE) and retinal microvascular parameters assessed using swept-source optical coherence tomography angiography (SS-OCTA) in patients with diabetic retinopathy (DR). This retrospective cross-sectional study included 180 patients with diabetes and 50 age-matched controls. Patients with diabetes were grouped according to the five-stage DR severity, combined with the presence of albuminuria. All subjects underwent 12×12mm2 field SS-OCTA. The foveal avascular zone metrics, vessel density, and capillary nonperfusion area (NPA) were quantified using a semi-automatic software algorithm on three different rectangular fields (3×3 mm2, 6×6 mm2, and 10×10 mm2). The correlations between albuminuria and the four OCTA parameters were analyzed. A total of 105 subjects had normal UAE, and 75 subjects had albuminuria. Of the 102 subjects whose DR severity was higher than mild non-proliferative DR (NPDR), capillary NPA on the 3×3 mm2, 6×6 mm2, and 10×10 mm2 fields was significantly larger in the albuminuria group. None of the OCTA parameters were significantly different between the two groups in subjects with mild NPDR or without DR. Multiple logistic regression analysis showed that an increase in NPA in the 6×6 mm2 and 10×10 mm2 fields was a significant risk factor for the presence of albuminuria (odds ratio = 1.92 and 1.35). An increase in capillary NPA was independently associated with albuminuria in patients with clinically significant DR levels. SS-OCTA imaging can be a useful marker for the early detection of diabetic nephropathy.

Modeling and optimization of atmospheric CO2 capture for neutralization of high alkaline wastewaters using response surface methodology

Lab-scale stirrer bubble and lab-scale stepped continuous flow capillary columns were developed to neutralize lime precipitation treated slaughterhouse wastewater (SWW) and recover the volatilized ammonia, using atmospheric CO2. These experiments were carried out using central composite design based on the response surface methodology. The carbonation process occurred in both processes. For the bubbling process, numerical optimization indicated a final pH of 8 with calcium and ammonium nitrogen removals of 76.0 and 66.2%, respectively, applying 21 h, air flow rate at 65 L h−1, the stirring speed at 52 rpm, and SWW volume at 178 mL. It was also observed that increasing the air flow rate can avoid the stirring step. For the capillary process, a pH of 8.2 and calcium and ammonium nitrogen removals of 81.0 and 57.5% were achieved, applying a SWW flow rate at 1.2 mL min−1, air flow rate at 90 L h−1, and capillary area at 700 cm2. Under optimal conditions, the flow capillary column was able to neutralize different SWW volumes, 178–478 mL, without significant differences in the collected samples, with the operation time varying between 4.48 and 10.20 h, respectively.

Abstract A098: Quantitative MRI metrics capture pancreatic cancer and stroma responses to novel KRAS inhibitor

Abstract Introduction Pancreatic ductal adenocarcinoma (PDA) is a deadly cancer with limited treatment options. Oncogene KRAS mutations found in majority of PDA patients with KRAS(G12D) mutation being the most common. A new KRAS(G12D) specific inhibitor, MRTX1133 has been shown to induce rapid tumor regression in PDA models while the effect on stroma is only revealed by postmortem analyses of tumor specimens, making it hard to assess the dynamics of stroma remodeling. Furthermore, in clinical testing of KRAS(G12C) inhibitor, only ~50% of patients responded to the treatment despite the presence of correct genetic mutation in biopsy specimens, therefore, early and accurate assessment of the drug-target engagement is important in clinical setting. Our study was designed to test the hypothesis that multimetric MRI captures early responses to KRAS(G12D) inhibitor beyond the change of tumor size in a PDA model. Especially, changes in apparent diffusion coefficient (ADC) from diffusion weighted (DW) MRI, Ktrans from dynamic contrast enhanced (DCE) MRI, and magnetization transfer ratio (MTR). Methods A genetically engineered model of PDA bearing KRAS(G12D) and Trp53 mutation referred to as KPC was used. Male and female mice were enrolled to receive MRTX1133 at 30mg/kg BID or PBS via i.p injection. Murine PDA cells bearing KRAS(G12C) mutation were inoculated in the flank of C57BL/6 mice to grow subcutaneous tumors. In vivo DW- and DCE-MRI were obtained on a 9.4T Bruker system employing pulse sequences insensitive to respiratory motion. Results In KPC mice, striking increase of tumor ADC were detected as early as 48h after treatment initiation and was confirmed by statistical analyses at 48h and day7 accompanied by decrease of tumor size, in contrast to a trend of increased tumor size and decreased ADC in PBS-treated mice. H&amp;E section revealed gross necrosis and extensive cell death. A clear increase of Ktrans suggesting an increase of capillary permeability and/or perfusion was detected at 48h, persisting to day7; while CD31 did not change significantly, capillary lumen area appeared enlarged at 48h, consistent with reduced interstitial fluid pressure resulted from clearance of stromal hyaluronic acid. A remarkable reduction of MTR at 48h clearly captured the stromal effect of MRTX1133 whereas no change observed in PBS-treated mice. Consistently, Sirius red (SR) staining for collagen revealed a high degree of heterogeneity where regions of depletion versus dense SR staining coexist. Lack of tumor regression and ADC change in KRAS(G12C) tumors confirmed the specificity of MRTX1133 to G12D however, a reduction of MTR was revealed, suggesting stromal impact as off-target effect of MRTX1133. Conclusion To our knowledge, this represents the first MRI study of the new KRAS inhibitor. The multimetric MRI approach is novel and significant because it captured MRTX1133-induced cancer cell death and stroma change over time. With further validation, these translatable imaging metrics can provide biological mechanism underneath tumor size change in the clinical setting. Citation Format: Mamta Gupta, Hoon Choi, Emma E. Furth, Miguel Joaquim, Stephen Pickup, Cynthia Clendenin, Margo Orlen, Thomas Karasic, Hee Kwon Song, Yong Fan, Peter O’Dwyer, Robert H. Vonderheide, Mark Rosen, Ben Z. Stanger, Rong Zhou. Quantitative MRI metrics capture pancreatic cancer and stroma responses to novel KRAS inhibitor [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A098.

Maternal GLP-1 receptor activation inhibits fetal growth.

Glucagon-like peptide 1 (GLP-1) regulates food intake, insulin production, and metabolism. Our recent study demonstrated that pancreatic α-cells-secreted (intraislet) GLP-1 effectively promotes maternal insulin secretion and metabolic adaptation during pregnancy. However, the role of circulating GLP-1 in maternal energy metabolism remains largely unknown. Our study aims to investigate systemic GLP-1 response to pregnancy and its regulatory effect on fetal growth. Using C57BL/6 mice, we observed a gradual decline in maternal blood GLP-1 concentrations. Subsequent administration of the GLP-1 receptor agonist semaglutide (Sem) to dams in late pregnancy revealed a modest decrease in maternal food intake during initial treatment. At the same time, no significant alterations were observed in maternal body weight or fat mass. Notably, Sem-treated dams exhibited a significant decrease in fetal body weight, which persisted even following the restoration of maternal blood glucose levels. Despite no observable change in placental weight, a marked reduction in the placenta labyrinth area from Sem-treated dams was evident. Our investigation further demonstrated a substantial decrease in the expression levels of various pivotal nutrient transporters within the placenta, including glucose transporter one and sodium-neutral amino acid transporter one, after Sem treatment. In addition, Sem injection led to a notable reduction in the capillary area, number, and surface densities within the labyrinth. These findings underscore the crucial role of modulating circulating GLP-1 levels in maternal adaptation, emphasizing the inhibitory effects of excessive GLP-1 receptor activation on both placental development and fetal growth.NEW & NOTEWORTHY Our study reveals a progressive decline in maternal blood glucagon-like peptide 1 (GLP-1) concentration. GLP-1 receptor agonist injection in late pregnancy significantly reduced fetal body weight, even after restoration of maternal blood glucose concentration. GLP-1 receptor activation significantly reduced the placental labyrinth area, expression of some nutrient transporters, and capillary development. Our study indicates that reducing maternal blood GLP-1 levels is a physiological adaptation process that benefits placental development and fetal growth.