Effects of five types of exercise on vascular function in postmenopausal women: a network meta-analysis and systematic review of 32 randomized controlled trials.

Background: As women age, especially after menopause, cardiovascular disease (CVD) prevalence rises, posing a significant global health concern. Regular exercise can mitigate CVD risks by improving blood pressure and lipid levels in postmenopausal women. Yet, the optimal exercise modality for enhancing vascular structure and function in this demographic remains uncertain. This study aims to compare five exercise forms to discern the most effective interventions for reducing cardiovascular risk in postmenopausal women. Methods: The study searched PubMed, Web of Science, Cochrane, EBSCO, and Embase databases. It conducted a network meta-analysis (NMA) of randomized controlled trials (RCTs) on five exercise interventions: continuous endurance training (CET), interval training (INT), resistance training (RT), aerobic combined with resistance training (CT), and hybrid-type training (HYB). Outcome measures included carotid artery intima-media thickness (IMT), nitric oxide (NO), augmentation index (AIx), pulse wave velocity (PWV), and flow-mediated dilatation (FMD) of the brachial artery. Eligible studies were assessed for bias using the Cochrane tool. A frequentist random-effects NMA was employed to rank exercise effects, calculating standardized mean differences (SMDs) with 95% confidence intervals (CIs). Results: The analysis of 32 studies (n = 1,427) indicates significant increases in FMD with CET, INT, RT, and HYB in postmenopausal women. Reductions in PWV were significant with CET, INT, RT, CT, and HYB. AIx decreased significantly with INT and HYB. CET, INT, and CT significantly increased NO levels. However, no significant reduction in IMT was observed. SUCRA probabilities show INT as most effective for increasing FMD, CT for reducing PWV, INT for decreasing AIx, CT for lowering IMT, and INT for increasing NO in postmenopausal women. Conclusion: The study demonstrates that CET, INT, RT, and HYB have a significant positive impact on FMD in postmenopausal women. Furthermore, all five forms of exercise significantly enhance PWV in this population. INT and HYB were found to have a significant positive effect on AIx in postmenopausal women, while CET, INT, and CT were found to significantly improve NO levels. For improving vascular function in postmenopausal women, it is recommended to prioritize INT and CT exercise modalities. On the other hand, as CET and RT were not ranked at the top of the Sucra value ranking in this study and were less effective than INT and CT as exercise interventions to improve vascular function in postmenopausal women, it is not recommended that CET and RT be considered the preferred exercise modality.

Visualization of intradermal blood vessel structures by dual-wavelength photoacoustic microscopy and characterization of three-dimensional construction of livedo-racemosa in cutaneous polyarteritis nodosa.

BACKGROUND: Photoacoustic microscopy is expected to have clinical applications as a noninvasive and three-dimensional (3D) method of observing intradermal structures. OBJECTIVE: Investigate the applicability of a photoacoustic microscope equipped with two types of pulsed lasers that can simultaneously recognize hemoglobin and melanin. METHODS: 16 skin lesions including erythema, pigmented lesions, vitiligo and purpura, were analyzed to visualize 3D structure of melanin granule distribution and dermal blood vessels. 13 cases of livedo racemosa in cutaneous polyarteritis nodosa (cPN) were further analyzed to visualize the 3D structure of dermal blood vessels in detail. Vascular structure was also analyzed in the biopsy specimens obtained from tender indurated erythema of cPN by CD34 immunostaining. RESULTS: Hemoglobin-recognition signal clearly visualized the 3D structure of dermal blood vessels and melanin-recognition signal was consistently reduced in vitiligo. In livedo racemosa, the hemoglobin-recognition signal revealed a relatively thick and large reticular structure in the deeper layers that became denser and finer toward the upper layers. The numerical analysis revealed that the number of dermal blood vessels was 1.29-fold higher (p<0.05) in the deeper region of the lesion than that of normal skin. The CD34 immunohistochemical analysis in tender indurated erythema revealed an increased number of dermal vessels compared with normal skin in 88.9% (8/9) of the cases, suggesting that vascular network remodeling had occurred in cPN. CONCLUSION: The photoacoustic system has an advantage in noninvasively detecting dermal blood vessel structures that are difficult to recognize by two-dimensional histopathology specimen examination and is worth evaluating in various skin diseases.

Distraction-aware hierarchical learning for vascular structure segmentation in intravascular ultrasound images.

Vascular structure segmentation in intravascular ultrasound (IVUS) images plays an important role in pre-procedural evaluation of percutaneous coronary intervention (PCI). However, vascular structure segmentation in IVUS images has the challenge of structure-dependent distractions. Structure-dependent distractions are categorized into two cases, structural intrinsic distractions and inter-structural distractions. Traditional machine learning methods often rely solely on low-level features, overlooking high-level features. This way limits the generalization of these methods. The existing semantic segmentation methods integrate low-level and high-level features to enhance generalization performance. But these methods also introduce additional interference, which is harmful to solving structural intrinsic distractions. Distraction cue methods attempt to address structural intrinsic distractions by removing interference from the features through a unique decoder. However, they tend to overlook the problem of inter-structural distractions. In this paper, we propose distraction-aware hierarchical learning (DHL) for vascular structure segmentation in IVUS images. Inspired by distraction cue methods for removing interference in a decoder, the DHL is designed as a hierarchical decoder that gradually removes structure-dependent distractions. The DHL includes global perception process, distraction perception process and structural perception process. The global perception process and distraction perception process remove structural intrinsic distractions then the structural perception process removes inter-structural distractions. In the global perception process, the DHL searches for the coarse structural region of the vascular structures on the slice of IVUS sequence. In the distraction perception process, the DHL progressively refines the coarse structural region of the vascular structures to remove structural distractions. In the structural perception process, the DHL detects regions of inter-structural distractions in fused structure features then separates them. Extensive experiments on 361 subjects show that the DHL is effective (e.g., the average Dice is greater than 0.95), and superior to ten state-of-the-art IVUS vascular structure segmentation methods.

Multi-task global optimization-based method for vascular landmark detection.

Vascular landmark detection plays an important role in medical analysis and clinical treatment. However, due to the complex topology and similar local appearance around landmarks, the popular heatmap regression based methods always suffer from the landmark confusion problem. Vascular landmarks are connected by vascular segments and have special spatial correlations, which can be utilized for performance improvement. In this paper, we propose a multi-task global optimization-based framework for accurate and automatic vascular landmark detection. A multi-task deep learning network is exploited to accomplish landmark heatmap regression, vascular semantic segmentation, and orientation field regression simultaneously. The two auxiliary objectives are highly correlated with the heatmap regression task and help the network incorporate the structural prior knowledge. During inference, instead of performing a max-voting strategy, we propose a global optimization-based post-processing method for final landmark decision. The spatial relationships between neighboring landmarks are utilized explicitly to tackle the landmark confusion problem. We evaluated our method on a cerebral MRA dataset with 564 volumes, a cerebral CTA dataset with 510 volumes, and an aorta CTA dataset with 50 volumes. The experiments demonstrate that the proposed method is effective for vascular landmark localization and achieves state-of-the-art performance.

Characterizing the Causal Pathway From Childhood Adiposity to Right Heart Physiology and Pulmonary Circulation Using Lifecourse Mendelian Randomization.

BACKGROUND: Observational epidemiological studies have reported an association between childhood adiposity and altered cardiac morphology and function in later life. However, whether this is due to a direct consequence of being overweight during childhood has been difficult to establish, particularly as accounting for other measures of body composition throughout the lifecourse can be exceptionally challenging. METHODS AND RESULTS: In this study, we used human genetics to investigate this using a causal inference technique known as lifecourse Mendelian randomization. This approach allowed us to evaluate the effect of childhood body size on 11 measures of right heart and pulmonary circulation independent of other anthropometric traits at various stages in the lifecourse. We found strong evidence that childhood body size has a direct effect on an enlarged right heart structure in later life (eg, right ventricular end-diastolic volume: ß=0.24 [95% CI, 0.15-0.33]; P=3×10-7) independent of adulthood body size. In contrast, childhood body size effects on maximum ascending aorta diameter attenuated upon accounting for body size in adulthood, suggesting that this effect is likely attributed to individuals remaining overweight into later life. Effects of childhood body size on pulmonary artery traits and measures of right atrial function became weaker upon accounting for adulthood fat-free mass and childhood height, respectively. CONCLUSIONS: Our findings suggest that, although childhood body size has a long-term influence on an enlarged heart structure in adulthood, associations with the other structural components of the cardiovascular system and their function may be largely attributed to body composition at other stages in the lifecourse.

A Vascular Feature Detection and Matching Method Based on Dual-Branch Fusion and Structure Enhancement.

How to obtain internal cavity features and perform image matching is a great challenge for laparoscopic 3D reconstruction. This paper proposes a method for detecting and associating vascular features based on dual-branch weighted fusion vascular structure enhancement. Our proposed method is divided into three stages, including analyzing various types of minimally invasive surgery (MIS) images and designing a universal preprocessing framework to make our method generalized. We propose a Gaussian weighted fusion vascular structure enhancement algorithm using the dual-branch Frangi measure and MFAT (multiscale fractional anisotropic tensor) to address the structural measurement differences and uneven responses between venous vessels and microvessels, providing effective structural information for vascular feature extraction. We extract vascular features through dual-circle detection based on branch point characteristics, and introduce NMS (non-maximum suppression) to reduce feature point redundancy. We also calculate the ZSSD (zero sum of squared differences) and perform feature matching on the neighboring blocks of feature points extracted from the front and back frames. The experimental results show that the proposed method has an average accuracy and repeatability score of 0.7149 and 0.5612 in the Vivo data set, respectively. By evaluating the quantity, repeatability, and accuracy of feature detection, our method has more advantages and robustness than the existing methods.

Quantitative Assessment Characteristics of Small Pulmonary Vessel Remodelling in Populations at High Risk for COPD and Smokers Using Low-Dose CT.

Purpose: To explore the morphological alterations in small pulmonary vessels in populations at high risk for chronic obstructive pulmonary disease (COPD) and smokers based on multiple computed tomography (CT) quantitative parameters. Patients and Methods: A total of 1969 Three Major Chest Diseases Screening Study participants with available demographic data and smoking history who underwent low-dose chest CT from 2018 to 2020 were included. All subjects were divided into normal, high risk for COPD, and COPD groups according to their pulmonary function test (PFT) results. Furthermore, the three groups were further subdivided into never-smokers, current smokers, and former smokers subgroups according to their smoking history. Quantitative parameters, such as the number, area at 6 mm~24 mm subpleura and volume of small pulmonary vessels, were extracted by computer software. Differences in small pulmonary vessel parameters among the groups were compared using two-way ANOVA. Results: The number, area at 6 mm~24 mm subpleura and volume of small pulmonary vessels in the group at high risk for COPD were lower than those in the normal group (P<0.05). The number, area at 6 mm~24 mm subpleura and volume of small pulmonary vessels in the COPD group were higher than those in the normal group (P<0.05). The number, area of small pulmonary vessels at 6 mm~12 mm subpleura in current smokers with high risk for COPD were higher than those in former smokers with high risk for COPD (P<0.05). Conclusion: The number, area, and volume of small pulmonary vessels in populations at high risk for COPD were decreased. Smoking cessation may impede structural changes in small pulmonary vessels in populations at high risk for COPD.

Quantitative analysis of age-related changes in vascular structure, oxygen saturation, and epidermal melanin structure using photoacoustic methods.

BACKGROUND: Vascular structure, blood oxygen saturation, and melanin status of the epidermis are chromophore factors related to light absorption. Therefore, they are likely to be related to skin appearance. Thus, it is important to measure these internal skin features and understand their characteristics. Thus, we aimed to analyze the individual differences and aging changes in the skin by measuring the internal skin characteristics, such as vascular structure, oxygen saturation, and the 3D distribution of melanin in the epidermis, using a noninvasive photoacoustic (PA) measurement method. MATERIALS AND METHODS: A PA measurement device was used as a noninvasive measurement method. Eighty Japanese women aged between 20 and 60 years were enrolled. The target area was the buccal region of the face. RESULTS: The blood vessel structure showed a decrease in fine vessels with age, with a stronger tendency observed in the dermis layer, and the volume of blood vessels was larger in the dermis layer than in the dermal-subcutaneous fat boundary layer. Oxygen saturation showed a similar decreasing trend with age in all depths examined. Melanin condition as the torus-like pattern structure tended to increase with age. CONCLUSION: PA measurements revealed the characteristics of several chromophores, providing a new skin aging mechanism.

Color-coded laparoscopic liver resection using artificial intelligence: A preliminary study.

Tashiro and colleagues demonstrated for the first time that an artificial intelligence system can precisely identify intrahepatic vascular structures during laparoscopic liver resection in real time through color coding under bleeding and indocyanine green fluorescent imaging. The system supports real-time navigation and offers potentially safer laparoscopic or robotic liver surgery.

Effects of concurrent aerobic and resistance training on vascular health in type 2 diabetes: a systematic review and meta-analysis.

Objective: To determine the impacts of concurrent aerobic and resistance training on vascular structure (IMT) and function (PWV, FMD, NMD) in type 2 diabetes (T2D). Methods: The electronic databases PubMed, Web of Science Core Collection, Cochrane Library, Embase, Scopus, CINAHL, and SPORTDiscus were systematically searched for articles on "type 2 diabetes" and "concurrent training" published from inception to August 2, 2022. We included randomized controlled trials that examined the effects of concurrent training versus passive controls on IMT, PWV, FMD and NMD in T2D. Results: Ten studies were eligible, including a total of 361 participants. For IMT, concurrent training showed a slight decrease by 0.05 mm (95% CI -0.11 to 0.01, p > 0.05). concurrent training induced an overall significant improvement in FMD by 1.47% (95% CI 0.15 to 2.79, p < 0.05) and PWV by 0.66 m/s (95% CI -0.89 to -0.43, p < 0.01) in type 2 diabetics. However, concurrent training seemed to exaggerate the impaired NMD (WMD = -2.30%, 95% CI -4.02 to -0.58, p < 0.05). Conclusions: Concurrent training is an effective method to improve endothelial function and artery stiffness in T2D. However, within 24 weeks concurrent training exacerbates vascular smooth muscle dysfunction. More research is needed to explore whether longer and/or higher-intensity concurrent training interventions could enhance the vascular structure and smooth muscle function in this population. Systematic review registration: www.crd.york.ac.uk/PROSPERO/, identifier CRD42022350604.

Increased stiffness of omental arteries from late pregnant women at advanced maternal age.

Advanced maternal age (≥35 years) is a risk factor for poor pregnancy outcomes. Pregnancy requires extensive maternal vascular adaptations, and with age, our blood vessels become stiffer and change in structure (collagen and elastin). However, the effect of advanced maternal age on the structure of human resistance arteries during pregnancy is unknown. As omental resistance arteries contribute to blood pressure regulation, assessing their structure in pregnancy may inform on the causal mechanisms underlying pregnancy complications in women of advanced maternal age. Omental fat biopsies were obtained from younger (<35 years) or advanced maternal age (≥35 years) women during caesarean delivery (n = 7-9/group). Arteries (200-300 µm) were isolated and passive mechanical properties (circumferential stress and strain) assessed with pressure myography. Collagen (Masson's Trichrome) and elastin (Verhoff) were visualized histologically and % positively-stained area was assessed. Median maternal age was 32 years (range 25-34) for younger, and 38 years (range 35-42) for women of advanced maternal age. Circumferential strain was lower in arteries from advanced maternal age versus younger women but circumferential stress was not different. Omental artery collagen levels were similar, while elastin levels were lower with advanced maternal age versus younger pregnancies. The collagen:elastin ratio was greater in arteries from advanced maternal age versus younger women. In conclusion, omental arteries from women of advanced maternal age were less compliant with less elastin compared with arteries of younger controls, which may affect how vascular stressors are tolerated during pregnancy. Understanding how vascular aging affects pregnancy adaptations may contribute to better pregnancy outcomes.

A new method for predicting the prognosis of ischemic stroke based vascular structure features and lesion location features.

OBJECTIVE: Determining the changes in the prognosis of the cerebral infarction area has an important guiding role in the selection of the treatment plan. The goal of this study is to propose a machine learning-based method that can predict the prognosis of stroke effectively and efficiently. METHODS: 97 cases of stroke were analyzed retrospectively. Firstly, we extracted vascular structural features from computed tomography angiography (CTA) images and stroke location features from diffusion-weighted imaging (DWI) images to comprehensively characterize the lesions, respectively. Then, we performed sparse representation-based feature selection and classification to predict the prognosis of stroke based on the extracted features. Finally, we randomly divided the 97 cases into cross-validation set, independent testing set 1 and independent testing set 2 to validate the proposed model. RESULTS: 464 vascular structure features and 116 positional features were extracted. After feature selection, 52 features were finally applied to build the classification model. The proposed model achieved promising prediction performance on the two independent testing sets, with the classification accuracies of 85.19% and 81.25%, respectively. CONCLUSION: The proposed machine learning approach can effectively mine and accurately quantify the features related to the prognosis, which include the vascular structural features and the stroke location features. In addition, the established prognostic prediction model based on these features has achieved interesting performances, which may provide valuable guidance for the clinical treatment of stroke.

Image-based modeling of vascular organization to evaluate anti-angiogenic therapy.

In tumor therapy anti-angiogenic approaches have the potential to increase the efficacy of a wide variety of subsequently or co-administered agents, possibly by improving or normalizing the defective tumor vasculature. Successful implementation of the concept of vascular normalization under anti-angiogenic therapy, however, mandates a detailed understanding of key characteristics and a respective scoring metric that defines an improved vasculature and thus a successful attempt. Here, we show that beyond commonly used parameters such as vessel patency and maturation, anti-angiogenic approaches largely benefit if the complex vascular network with its vessel interconnections is both qualitatively and quantitatively assessed. To gain such deeper insight the organization of vascular networks, we introduce a multi-parametric evaluation of high-resolution angiographic images based on light-sheet fluorescence microscopy images of tumors. We first could pinpoint key correlations between vessel length, straightness and diameter to describe the regular, functional and organized structure observed under physiological conditions. We found that vascular networks from experimental tumors diverted from those in healthy organs, demonstrating the dysfunctionality of the tumor vasculature not only on the level of the individual vessel but also in terms of inadequate organization into larger structures. These parameters proofed effective in scoring the degree of disorganization in different tumor entities, and more importantly in grading a potential reversal under treatment with therapeutic agents. The presented vascular network analysis will support vascular normalization assessment and future optimization of anti-angiogenic therapy.

Klotho promotes AMPK activity and maintains renal vascular integrity by regulating the YAP signaling pathway.

The development and formation of mammalian blood vessels are closely related to the regulation of signal transduction pathways. Klotho/AMPK and YAP/TAZ signaling pathways are closely related to angiogenesis, but the internal relationship between them is not clear. In this study, we found that Klotho heterozygous deletion mice (Klotho+/- mice) had obvious thickening of the renal vascular wall, obvious enlargement of vascular volume, and significant proliferation and pricking of vascular endothelial cells. Western blot showed that the expression levels of total YAP protein, p-YAP protein (Ser127 and Ser397), p-MOB1, MST1, LATS1, and SAV1 in renal vascular endothelial cells were significantly lower in Klotho+/- mice than in wild-type mice. Knockdown of endogenous Klotho in HUVECs accelerated their ability to divide and form vascular branches in the extracellular matrix. Meanwhile, the results of CO-IP western blot showed that the expression of LATS1 and p-LATS1 interacting with AMPK protein decreased significantly, and the ubiquitination level of YAP protein also decreased significantly in vascular endothelial cells of kidney tissue of Klotho+/- mice. Subsequently, continuous overexpression of exogenous Klotho protein in Klotho heterozygous deficient mice effectively reversed the abnormal renal vascular structure by weakening the expression of the YAP signal transduction pathway. Therefore, we confirmed that Klotho and AMPKα proteins were highly expressed in vascular endothelial cells of adult mouse tissues and organs; this resulted in a phosphorylation modification of YAP protein, closed the activity of the YAP/TAZ signal transduction pathway, and inhibited the growth and proliferation of vascular endothelial cells. When Klotho was absent, the phosphorylation modification of YAP protein by AMPKα was inhibited, resulting in the activation of the YAP/TAZ signal transduction pathway and finally inducing the excessive proliferation of vascular endothelial cells.

Two-step method fabricating a 3D nerve cell model with brain-like mechanical properties and tunable porosity vascular structures via coaxial printing.

Three-dimensional (3D) nerve cell models have been widely developed to understand the mechanisms and discover treatment methods of ischemic stroke and neurodegenerative disease. However, there is a contradiction in the production of 3D models that they should possess high modulus to ensure mechanical stability while low modulus to provide mechanical stimuli for nerve cells. In addition, it is challenging to maintain the long-term viability of 3D models when lacking vascular structures. Here, a 3D nerve cell model with brain-like mechanical properties and tunable porosity vascular structures has been fabricated. The matrix materials with brain-like low mechanical properties were favorable for promoting HT22 proliferation. The nerve cells could exchange nutrients and waste with the cultural environment through vascular structures. The vascular structures also played a supporting role, and model stability was enhanced by combining matrix materials with vascular structures. Furthermore, the porosity of vascular structure walls was adjusted by adding sacrificial materials to the tube walls during 3D coaxial printing and removing them after preparation, resulting in tunable porosity vascular structures. Finally, HT22 cells showed better cell viability and proliferation performance after culturing 7 days in the 3D models with vascular structures than in the 3D models with solid structures. All these results suggest that this 3D nerve cell model possesses good mechanical stability and long-term viability, which is expected to be used in pathological studies and drug screening for ischemic stroke and neurodegenerative diseases.

Difficult differential diagnosis of ectopic germinoma from multiple sclerosis: A case report and literature review.

INTRODUCTION AND IMPORTANCE: Intracranial germinomas are germ cell tumors that commonly develop in the pineal or neurohypophysis regions. As ectopic germinomas are rarely observed within the cerebrum and are associated with atypical image findings, diagnosis is challenging. CASE PRESENTATION: A 14-year-old boy was admitted to our hospital with complaints of vomiting and headache. Gadolinium-enhanced magnetic resonance imaging revealed ring-enhancing lesions in his left frontal lobe and basal ganglia. Susceptibility-weighted imaging indicated that the subependymal veins passing through the lesion centers were engorged, while electrophoretic analysis of cerebrospinal fluid identified oligoclonal bands (OCBs); both were typical of multiple sclerosis (MS). Tumor biopsy revealed many cells with atypical mitotic figures and nuclear enlargements, suggesting malignant disease. As the tumor rapidly proliferated, we opted for surgical excision of the lesions. Histopathological analyses revealed "two-cell patterns" characteristic of germinoma. Immunohistochemistry was positive for placental alkaline phosphatase and c-KIT. The definitive diagnosis was germinoma. After chemoradiotherapy, the patient was discharged without neurological deficits. CLINICAL DISCUSSION: OCBs and several magnetic resonance imaging features (including open ring enhancement, T2 hypointense rims, mild mass effects, mild perilesional edema, peripheral restriction around the lesion, and vessel-like structures running through the lesion center) are useful diagnostic signs for the radiological discrimination of MS from germinoma. However, owing to these factors, some cases are difficult to diagnose. CONCLUSION: Our case report of an unusual ectopic cerebral germinoma illustrates the difficulty of distinguishing it from MS. Therefore, we recommend proper tissue sampling in such cases, especially in adolescent patients, to make definitive germinoma diagnoses.

The cardiovascular challenges in giraffes.

Giraffes are the highest living animals on Earth and therefore are challenged by gravity more than any other species. In particular the cardiovascular system needs to adapt to this challenge. Giraffes have a mean blood pressure around 200 mmHg, which ensures a mean arterial pressure near the head of 100 mmHg when the giraffe is standing with the neck in a near vertical position. This immediately raises several questions. How do giraffes avoid edema in the legs where the arterial pressure is 300 mmHg or higher? How does the heart produce a pressure of 200 mmHg, and what is the energy required for this endeavor? How can the kidney tolerate a pressure of about 200 mmHg and does this mean that giraffes have a high glomerular filtration rate? What is the arterial pressure in the head of giraffes when they drink, and how is perfusion of the brain maintained when they lift their head after drinking? In this short review, we present some answers to these questions.

The Multiple Roles of Pericytes in Vascular Formation and Microglial Functions in the Brain.

In the capillary walls, vascular endothelial cells are covered with mural cells, such as smooth muscle cells and pericytes. Although pericytes had been thought to play simply a structural role, emerging evidence has highlighted their multiple functions in the embryonic, postnatal, and adult brain. As the central nervous system (CNS) develops, the brain's vascular structure gradually matures into a hierarchical network, which is crucial for the proper development of neural lineage cells by providing oxygen and nutrients. Pericytes play an essential role in vascular formation and regulate blood‒brain barrier (BBB) integrity as a component of the neurovascular unit (NVU), in collaboration with other cells, such as vascular endothelial cells, astrocytes, neurons, and microglia. Microglia, the resident immune cells of the CNS, colonize the brain at embryonic day (E) 9.5 in mice. These cells not only support the development and maturation of neural lineage cells but also help in vascular formation through their extensive migration. Recent studies have demonstrated that pericytes directly contact microglia in the CNS, and their interactions have a profound effect on physiological and pathological aspects. This review summarizes the function of pericytes, focusing on the interplay between pericytes and microglia.

Effects of omega-3 supplementation on endothelial function, vascular structure, and metabolic parameters in adolescents with type 1 diabetes mellitus: A randomized clinical trial.

Background: Vascular dysfunction is a major complication of diabetes mellitus that leads to cardiovascular disease (CVD). This study aimed to examine the effects of omega-3 consumption on endothelial function, vascular structure, and metabolic parameters in adolescents with type 1 diabetes mellitus (T1DM). Methods: In this randomized, double-blind, placebo-controlled clinical trial, 51 adolescents (10-18 years) with T1DM completed the study. Patients received 600 mg/day [containing 180 mg eicosapentaenoic acid (EPA) and 120 mg docosahexaenoic acid (DHA)] of omega-3 or placebo for 12 weeks. Flow-mediated dilation (FMD), carotid intima-media thickness (CIMT), high-sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol, blood urea nitrogen (BUN), creatinine, fasting blood sugar (FBS), hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), serum insulin (SI), urine albumin-creatinine ratio (uACR), blood pressure, and anthropometric indices were assessed at the baseline and after the intervention. Results: Following supplementation, omega-3 significantly increased FMD (3.1 ± 4.2 vs. -0.6 ± 4%, p = 0.006) and decreased TG (-7.4 ± 10.7 vs. -0.1 ± 13.1 mg/dl, p = 0.022) in comparison with the placebo group. However, no significant difference was observed regarding CIMT (-0.005 ± 0.036 vs. 0.003 ± 0.021 mm, p = 0.33). Although hs-CRP was significantly decreased within the omega-3 group (p = 0.031); however, no significant change was observed compared to placebo group (p = 0.221). Omega-3 supplementation had no significant effect on other variables. Conclusion: Given the elevation in FMD and reduction in TG, omega-3 supplementation can improve vascular function and may reduce the risk of cardiovascular disease in adolescents with T1DM patients.

Numerical simulation of the vascular structure dependence of blood flow in the kidney.

A numerical simulation was performed to clarify renal blood flow determination by the vascular structures. Large and small vessels were modeled as symmetric and asymmetric branching vessels, respectively, with simple geometries to parameterize the vascular structures. Modeling individual vessels as straight pipes, Murray's law was used to determine the vessel diameters. Blood flow in the vascular structure was calculated by network analysis based on Hagen-Poiseuille's law. Blood flow simulations for a vascular network segment demonstrated that blood flow rate and pressure vary within the same-generation vessels because of an asymmetric vessel branch while they generally tend to decrease with vessel diameter; thus, the standard deviation of flow rate relative to the mean (relative standard deviation [RSD]) increased from 0.4 to 1.0 when the number of the daughter vessels increased from 3 to 10. Blood flow simulations for an entire vascular network of a kidney showed that the vessel number and branching style, rather than Strahler order, are major parameters in successfully reproducing renal blood flow measured in published experiments. The entire vascular network could generate variation in the physiological flow rate in afferent arterioles at 0.2-0.38 in RSD, which is at least compatible with 0.16 by diameter variation within the same-generation vessels.