Vascular Structures Research Articles

Traumatic lateral spondyloptosis and lateraloptosis with partial improvement through posterior surgical approach: a review based on a case report

Introduction. Spondyloptosis or grade V of spondylolisthesis, spinal injury that involve 100 % mobilization of the vertebral body, is rare to find. Lateraloptosis, displacement of vertebral bodies, is even more rare a catastrophic.The aim of this study to introduce readers to this rare form of traumatic lumbar spine injury as well as to review current available therapeutic approaches.Case report. A 22-year-old male was admitted to the emergency room due to a fall from a moving truck. Physical examination revealed neurological deficit in the lower extremities, with muscle strength 0/5, and an ASIA B classification. Computed tomography study showed a complete lateroloptosis at the L3 –L4 level. The patient is admitted to the operating room for surgical treatment through a posterior approach. Successful arthrodesis and spinal alignment are achieved. Immediate postoperative period, showed no complications and the patient’s neurological function in the lower extremities was classified as ASIA C. In the posterior follow-up, the patient maintains the motor neurological function and recover the autonomic control of bladder function. With mild disability according to the Barthel Index of 90 points.Discussion. of the traumatic spinal injuries, spondyloptosis is the most infrequent and occurs secondary to high-energy mechanisms. It presents an incidence of complete neurological deficit in 80 % of patients. The objectives in surgical treatment are decompression of neurovascular structures, reduction of fracture dislocation to improve alignment in the sagittal and coronal plane, and instrumentation that allows stability. The posterior surgical approach offers advantages over the anterior approach. In the posterior approach, the facet joints can be manipulated more safely, decompress the nerve roots and the dural sac more easily, as well as less operating time and greater care of vascular structures such as the iliac vessels.Conclusion. Complex traumatic spinal injuries are associated with irreversible neurological damage. Achieving spinal stability and alignment allows optimizing physical therapy and rehabilitation for greater recovery. Severe spinal injuries, especially lateroptosis, are difficult to treat by surgical approach, however, the main objective is vertebral stabilization to allow physical therapy and early rehabilitation.

Nephronsparing surgery for retroperitoneal sarcomas

Objective: to clarify the indications for the use of nephron-sparing technologies in surgical treatment of patients with retroperitoneal sarcomas. Material and Methods. The study included 64 patients with primary retroperitoneal sarcomas with kidney and renal pedicle invasion, who underwent surgical treatment in the Thoracic-abdominal Department of the P.A. Herzen Moscow Oncology Research Institute from 2010 to 2021. Twenty-one patients underwent nephrectomies, and 43 patients underwent nephron-sparing surgery. The morphological profile of sarcomas, age and gender of the patients, feasibility of using nephron-sparing technologies, postoperative complications, and long-term outcomes in patients of both groups were analyzed. Results. Forty-three patients with primary retroperitoneal sarcomas with invasion of the renal parenchyma, ureter, and renal pedicle underwent nephron-sparing surgery (precision mobilization of the kidney, ureter and vascular structures of the kidney from tumor tissue, kidney resection, ureteral stenting, resection of the renal vein orifices, resection of the ureters, and kidney autotransplantation). Postoperative complications were observed in 19.0 % of nephrectomy group patients (4 pts: II, IIIB, IV and V types according to Clavien–Dindo) and in 30.2 % of nephron-sparing group patients (15 pts: types II – 8, IIIA – 1, IIIB – 3, IV – 1). No statistical differences in the relapse-free period and survival time between two groups were observed. The 1-, 3- and 5-year survival rates were 84.1 %, 65.9 %, and 51.4 %, respectively. Multifactorial analysis showed that mortality increased significantly in patients over 64 years of age and was associated with both disease recurrence and concomitant pathology (p=0.009). There was also a trend toward decreased survival in patients with leiomyosarcoma (p=0.066). Conclusion. In retroperitoneal sarcomas, tumor resection with preservation of organs and structures not directly invaded by the tumor is the optimal surgical strategy. Nephron-sparing technologies do not worsen both immediate and long-term treatment outcomes. For leiomyosarcoma, tumor resection with nephrectomy is the most suitable approach.

Mechanisms underlying age-associated exacerbation of pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease (PVOD) is a rare but severe form of pulmonary hypertension characterized by the obstruction of pulmonary arteries and veins, causing increased pulmonary artery pressure and leading to right ventricular (RV) heart failure. PVOD is often resistant to conventional pulmonary arterial hypertension (PAH) treatments and has a poor prognosis, with a median survival time of 2-3 years after diagnosis. We previously showed that the administration of a chemotherapy agent mitomycin C (MMC) in rats mediates PVOD through the activation of the eukaryotic initiation factor 2 (eIF2) kinase protein kinase R (PKR) and the integrated stress response (ISR), resulting in the impairment of vascular endothelial junctional structure and barrier function. Here, we demonstrate that aged rats over 1 year exhibit more severe vascular remodeling and RV hypertrophy than young adult rats following MMC treatment. This is attributed to an age-associated elevation of basal ISR activity and depletion of protein phosphatase 1, leading to prolonged eIF2 phosphorylation and sustained ISR activation. Pharmacological blockade of PKR or ISR mitigates PVOD phenotypes in both age groups, suggesting that targeting the PKR/ISR axis could be a potential therapeutic strategy for PVOD.

Accelerating healing at high altitudes: Oxygen and bFGF delivery through nanoparticle-loaded gel dressings

High altitude environment is mainly characterized by low oxygen. Due to persistent hypoxia, nonhealing wounds are common in high-altitude areas. Moreover, Basic fibroblast growth factor (bFGF) is a versatile biologically active substance that has crucial impact on wound healing. Given the limited availability of atmospheric oxygen and reduced blood oxygen saturation in high-altitude area, and the challenge that arises from direct oxygen and bFGF delivery to wounds through the traumatized vascular structure, it necessitates an innovative solution for local and permeable delivery of oxygen and bFGF. In this study, we present a strategy that involves revamping traditional gel-based wound dressings through the incorporation of nanoparticles encapsulating oxygen and bFGF, engineered to facilitate the localized delivery of dissolved oxygen and bFGF to wound surfaces. The prospective evaluation of this delivery technique's therapeutic impacts on epithelial, endothelial and fibroblasts cells can be materialized. Further experiment corroborated these effects on a high-altitude wounds' murine model. Given its biocompatibility, efficacy, and utility, we posit that NOB-Gel exhibits remarkable translational potential for managing and hastening the healing process of an array of clinical wounds, more so for wounds inflicted at high altitudes.

Serjania piscatoria (Paullinieae, Sapindaceae) as a symbol of vascular variants polymorphism

Abstract Serjania is the only genus of the Paullinieae tribe that exhibits all patterns of vascular variants and includes S. piscatoria which shows a complex vascular structure that has intrigued botanists for centuries. Here, we analysed the stem development of S. piscatoria in an evolutionary context. We studied four individuals using standardized anatomical techniques and employed DNA sequencing to determine the species’ phylogenetic position. Additionally, we explored the evolution of stem developmental diversity using stochastic character mapping of the categories and patterns of vascular variants. We find that disparate ontogenetic processes determine the stem development in S. piscatoria, which results in vascular variants derived from procambial variants, cambial variants, and ectopic cambia. This diversity underscores the developmental lability of vascular meristems, making the species' vascular system structurally diverse and polymorphic. The complex vascular system observed in S. piscatoria evolved within a lineage composed of species with compound stems. These findings provide evidence for the intricate and labile evolutionary history of stem vasculature in Serjania, and the value of studying vascular variants to unravel the patterns and processes shaping plant diversity.

Proximal Fibulectomy for Giant Cell Tumours: What Works!

Giant cell tumor of bone (GCTB) is the most common primary tumor of proximal fibula. Because of its close proximity to vascular structures, common peroneal nerve (CPN) and attachment of lateral collateral ligament (LCL), proximal fibulectomy poses unique challenges. We analyzed oncological and functional outcome of patients who underwent proximal fibulectomy for GCTB of proximal fibula. Between January 2006 and December 2020, 23 patients underwent proximal fibulectomy for GCTB of proximal fibula, four were recurrent tumors. Mean resection length was 9cm (5 to 15cm). The LCL and biceps tendon were not reconstructed in 22 cases. The common peroneal nerve was sacrificed in seven patients including three recurrent cases. Functional status was assessed using the Musculoskeletal Tumour Society (MSTS) scoring system. There were two vascular complications and one infection. With 4 patients lost to follow up, mean follow up was 90months (12 to 197). No patient had local or distant recurrence. Mean MSTS score was 26 (21 to 30). Eleven of 23 patients (48%) had loss of common peroneal nerve function with poorer functional outcome. No patient had symptoms suggestive of knee instability. Proximal fibulectomy is oncologically safe. Reconstruction of the LCL attachment is not mandatory and patients do not have symptomatic knee instability. Functional outcomes are compromised after sacrifice of common peroneal nerve and may be potentially improved with tendon transfers at index surgery.

3D Vessel Segmentation With Limited Guidance of 2D Structure-Agnostic Vessel Annotations.

Delineating 3D blood vessels of various anatomical structures is essential for clinical diagnosis and treatment, however, is challenging due to complex structure variations and varied imaging conditions. Although recent supervised deep learning models have demonstrated their superior capacity in automatic 3D vessel segmentation, the reliance on expensive 3D manual annotations and limited capacity for annotation reuse among different vascular structures hinder their clinical applications. To avoid the repetitive and costly annotating process for each vascular structure and make full use of existing annotations, this paper proposes a novel 3D shape-guided local discrimination (3D-SLD) model for 3D vascular segmentation under limited guidance from public 2D vessel annotations. The primary hypothesis is that 3D vessels are composed of semantically similar voxels and often exhibit tree-shaped morphology. Accordingly, the 3D region discrimination loss is firstly proposed to learn the discriminative representation measuring voxel-wise similarities and cluster semantically consistent voxels to form the candidate 3D vascular segmentation in unlabeled images. Secondly, the shape distribution from existing 2D structure-agnostic vessel annotations is introduced to guide the 3D vessels with the tree-shaped morphology by the adversarial shape constraint loss. Thirdly, to enhance training stability and prediction credibility, the highlighting-reviewing-summarizing (HRS) mechanism is proposed. This mechanism involves summarizing historical models to maintain temporal consistency and identifying credible pseudo labels as reliable supervision signals. Only guided by public 2D coronary artery annotations, our method achieves results comparable to SOTA barely-supervised methods in 3D cerebrovascular segmentation, and the best DSC in 3D hepatic vessel segmentation, demonstrating the effectiveness of our method.

Vascular responsiveness to low-dose dexamethasone in extremely premature infants: negative influence of fetal growth restriction.

Dexamethasone is frequently prescribed for preterm infants to wean from respiratory support and/or to facilitate extubation. This pre-/postintervention prospective study ascertained the impact on clinical (respiratory support) and echocardiographic parameters after dexamethasone therapy in preterm fetal growth restriction (FGR) infants compared with appropriate for gestational age (AGA) infants. Echocardiography was performed within 24 h before the start and after completion of 10-day therapy. Parameters assessed included those reflecting pulmonary vascular resistance and right ventricular output. Seventeen FGR infants (birth gestation and birth weight, 25.2 ± 1.1 wk and 497 ± 92 g, respectively) were compared with 22 AGA infants (gestation and birth weight, 24.5 ± 0.8 and 663 ± 100 g, respectively). Baseline respiratory severity score (mean airway pressure × fractional inspired oxygen) was comparable between the groups, (median [interquartile range] FGR, 10 [6, 13] vs. AGA, 8 ± 2.8, P = 0.08). Pre-dexamethasone parameters of pulmonary vascular resistance (FGR, 0.19 ± 0.03 vs. AGA, 0.2 ± 0.03, P = 0.16) and right ventricular output (FGR, 171 ± 20 vs. 174 ± 17 mL/kg/min, P = 0.6) were statistically comparable. At post-dexamethasone assessments, the decrease in the respiratory severity score was significantly greater in AGA infants (median [interquartile range] FGR, 10 [6, 13] to 9 [2.6, 13.5], P = 0.009 vs. AGA, 8 ± 2.8 to 3 ± 1, P < 0.0001). Improvement in measures of pulmonary vascular resistance (ratio of time to peak velocity to right ventricular ejection time) was greater in AGA infants (FGR, 0.19 ± 0.03 to 0.2 ± 0.03, P = 0.13 vs. AGA 0.2 ± 0.03 to 0.25 ± 0.03, P < 0.0001). The improvement in right ventricular output was significantly greater in AGA infants (171 ± 20 to 190 ± 21, P = 0.014 vs. 174 ± 17 to 203 ± 22, P < 0.0001). This highlights differential cardiorespiratory responsiveness to dexamethasone in extremely preterm FGR infants, which may reflect the in utero maladaptive state.NEW & NOTEWORTHY Dexamethasone (DEX) is frequently used in preterm infants dependent on ventilator support. Differences in vascular structure and function that may have developed prenatally arising from the chronic intrauterine hypoxemia in FGR infants may adversely affect responsiveness. The clinical efficacy of DEX was significantly less in FGR (birth weight < 10th centile) infants, compared with appropriate for gestational age (AGA) infants. Echocardiography showed significantly less improvement in pulmonary vascular resistance in FGR, compared with AGA infants.

Abstract P223: Impact Of Dynamic Or Static Training On Flow-Mediated Dilatation Following Prolonged Head-Down Tilt Bedrest

Cardiovascular deconditioning, cephalad fluid shifts, and altered sympathetic activity in weightlessness may elicit changes in vascular structure and function akin to vascular ageing. Head-down tilt bedrest is an established terrestrial model for weightlessness and elicits similar cardiovascular responses. We hypothesized that 30 days head-down tilt bedrest (HDTBR) worsens flow mediated dilation (FMD), a non-invasive endothelial function marker, and that daily orthostatic stimuli or physical exercise attenuates the response. Fourty-seven healthy individuals (20 women, age 35±9 years, BMI 23.7±2.6 kg/m 2 ) were assigned to 30 days of strict HDTBR and divided into four groups: Daily 6 hours of upright sitting (positive control, n=11); 6 hours of -25 mmHg lower body negative pressure (n=12); 60 minutes of supine cycling followed by 6 hours of thigh cuff venous occlusion 6 days per week (n=12), or no countermeasure (negative control, n=12). We measured upper arm blood pressure and heart rate 5 days before and immediately after bedrest. We assessed plasma volume by carbon monoxide-rebreathing 2 days before and on day 28 of bedrest. We determined FMD of the brachial artery 5 days before, on day 28 of bedrest, and after 13-day recovery. We collected blood samples to measure pro- and anti-inflammatory cytokines. Heart rate was elevated after bedrest (p&lt;0.0001) but remained constant in seated and cycling groups (seated MD 5±2 /min, cycling MD 5±2, p=0.0051). Systolic blood pressure increased in all groups (MD 4±1 mmHg, p=0.0004). Diastolic blood pressure was higher post-bedrest in the control group (MD 8±2 mmHg, p=0.0002) but remained constant in the countermeasure groups. Plasma volume was reduced after bed rest (MD -400±37 ml, p&lt;0.0001) but maintained in the cycling group (MD 147±72 ml, p=0.0001). FMD did not differ between groups, but was higher at bedrest (MD 1.9±0.8 %, p=0.0481), whereas recovery values did not differ from baseline. Resting brachial artery diameter tended to be higher at bedrest (p=0.0876). Cytokines revealed no clinically relevant inflammatory response. Head-down tilt bedrest-induced cardiovascular deconditioning, which was not completely abolished by any countermeasure, paradoxically increased flow-mediated brachial vasodilation. Additional cardiovascular risk factors may be required to express endothelial dysfunction in the face of reduced physical activity.

Abstract P448: Follistatin Improves Vascular Function by Regulating Perivascular Adipose Tissue in Essential Hypertension

Introduction: Essential hypertension is characterized by resistance artery remodeling induced by oxidative stress. Most vessels are surrounded by perivascular adipose tissue (PVAT) which regulates vascular tone via release of vasoactive substances. In physiological conditions, PVAT induces an anticontractile effect. In pathological conditions such as hypertension, PVAT exhibit increased oxidative stress resulting in augmented contraction and reduced relaxation. Follistatin, an antioxidant glycoprotein, has been shown to induce adipose tissue browning which is linked to improved vasorelaxation and BP. We hypothesize that follistatin, through ROS inhibition and PVAT browning, lowers BP and improves vessel function in a model of essential hypertension. Methods: Spontaneously hypertensive rats (SHR) were treated with vehicle or follistatin every other day for 8 weeks. Wistar Kyoto (WKY) rats served as normotensive controls. BP was measured weekly by radiotelemetry. Mesenteric arteries and PVAT were used. KCl-induced smooth muscle contraction was assessed using wire myography. ROS was measured by DHE (dihydroethidium) staining. Vasodilator nitric oxide (NO) bioavailability in PVAT was measured using DAF-2 FM. Protein expression of markers for ROS or PVAT browning was measured by immunohistochemistry. Results: Follistatin significantly lowered BP in SHRs and restored anticontractile effect of PVAT. Increased ROS in SHR vessels and PVAT were also inhibited. Follistatin inhibited SHR PVAT-induced vascular oxidative stress. SHR PVAT NO bioavailability was increased by acute follistatin treatment via ROS inhibition. Follistatin also increased expression of brown adipose tissue markers in SHR PVAT suggesting PVAT browning. Limitations: Above studies do not confirm whether PVAT pathology causes hypertension in this model. Vascular dysfunction is an independent risk factor for CVD and our studies do not yet consider effects of follistatin on end-organ damage. Conclusions: Follistatin lowers BP in SHRs likely via improved vascular and perivascular structure and function. Specifically, follistatin inhibited perivascular ROS, increased NO and induced PVAT browning suggesting improved regulation of vascular function and thus, BP. Future work will utilize proteomic assays to identify novel mediators of follistatin effects on PVAT in the SHR.

Correlation of MRI brain findings with executive dysfunction and vascular risk factors in elderly patients with cognitive impairment

Objectives: The primary objective of the present study was to investigate the relationship between gray matter changes, white matter changes and executive function among older Indian adults with vascular risk factors. Methods: This hospital based observational analytical study was conducted in a tertiary care health facility located in the north-western region of India for a duration of one year between October 2021 and September 2022 among patients between 60 and 90 years of age presenting to the outpatient sections of Department of Neurology with executive dysfunction. We assessed the vascular risk factors, evaluated executive function, and then the patients underwent brain MRI on a 1.5T MRI scanner. Results: The proportion of patients with dorsolateral atrophy was significantly higher (p&lt;0.001) among patients with executive dysfunction (83.10%). Hypertension significantly contributed to predict the atrophy of temporal lobe and parietal lobe (p&lt;0.05). Hyperintensity of periventricular area was found significantly higher among executive dysfunction patients (85.92%). Elevated HbA1c levels and smoking significantly contributed to predict the white matter hyperintensity of basal ganglia (p&lt;0.05). The present study also found that hypertension and alcohol use significantly predicted white matter hyperintensity in the frontal area (p&lt;0.05). Conclusion: Specific white matter hyperintensity loci and grey matter volume loss were closely associated with executive dysfunction in elderly. It is understood that modifying and treating vascular risk factors can prevent progression of executive dysfunction and these findings emphasize the complex nature of the relationship between vascular risk factors, cognitive impairment, and brain structure.

Abstract P449: A Murine Model of Mid-Thoracic Aortic Coarctation

Vascular pressure can directly affect cardiovascular structure and function. Understanding the mechanisms, however, is complicated because conditions or interventions that chronically raise blood pressure (e.g. excess angiotensin II) can also have direct effects on the vasculature that occur independent of changes in blood pressure. One approach to mitigating this problem is to obstruct flow in a vascular segment sufficiently to reduce blood pressure in the segment downstream of the obstruction, while pressure upstream either stays the same or increases. As a result, all factors other than pressure are expected to be the same in upstream and downstream vascular segments. We have found evidence that differences in intravascular pressure can also affect closely adjacent tissues, specifically perivascular adipose tissue (PVAT). To test this idea in vivo , we developed a method to produce chronic, partial occlusion (or coarctation) of the mid-thoracic aorta in mice. This exposes upstream aortic PVAT depots to significantly higher aortic pressure than downstream aortic PVAT depots. The key to the method is producing a stable occlusion with a diameter small enough to produce a pressure gradient but not so small that the downstream flow is inadequate to support tissue oxygenation. To this end, a thoracotomy was performed to expose the thoracic aorta in adult mice anesthetized with isoflurane and artificially ventilated. A coarctation of the mid-thoracic aorta was produced by tying a ligature around the aorta and a blunted needle on the aorta, then removing the needle. In other mice, a silicone rubber or nitrile O-ring of varying dimensions was placed around the aorta. Mice were allowed to recover for varying periods of time (weeks), then the degree of coarctation was evaluated using both imaging methods (ultrasound) and direct measurement of the pressure gradient (catheters placed in a carotid and a femoral artery) under isoflurane anesthesia. In a group of 9 male mice with coarctation and 4 male mice with sham coarctation, we found an average mean arterial pressure gradient of 11.7 ± 5.0 mmHg (mean ± SEM) in coarct mice and 1.6 ± 2.0 mmHg in sham mice. Systolic pressure gradients averaged 14.0 ± 5.9 mmHg in coarct mice and 1.0 ± 3.2 mmHg in sham mice. These results suggest it is possible to produce a stable pressure gradient across the thoracic aorta of mice as a tool to explore the impact of arterial pressure on vascular and PVAT structure and function.

Chorionic vascular endothelial structure of the placenta in patients with preeclampsia by transmission electron microscope

Chorionic vascular endothelial structure of the placenta in patients with preeclampsia by transmission electron microscope

Diameter-dependent classification of dermal vasculature using optical coherence tomography angiography.

Dermal blood vessels beneath the epidermis play critical roles in epidermal homeostasis and are functionally divided into several types, such as capillaries. Optical coherence tomography angiography (OCTA) is a powerful tool for the non-invasive assessment of dermal vasculature. However, the classification of vessel types has been limited. To address this issue, we proposed an algorithm for diameter-dependent classification that preserves three-dimensional (3D) information using OCTA. OCTA data were acquired by a prototype swept-source-type optical coherence tomography (OCT) system, which was processed through several imaging filters: an optical microangiography (OMAG) imaging filter, a vesselness imaging filter, and a diameter map filter. All vessels were visually classified into three types based on their diameters, as micro-vessels, intermediate vessels, and thick vessels. Aging-related alterations and their association with the epidermis were investigated for each vessel type. The measurements were conducted on the cheeks of 124 female subjects aged 20-79 years. The 3D vascular structure was visualized by applying our proposed post-processing filters. Based on visual assessment, the thresholds for the diameters of the micro, intermediate and thick vessels were set at 80 and 160 µm. It was found that micro-vessels were predominantly located in the upper layer of the dermis and thick vessels in the deeper layer. Analysis of vessel metrics revealed that the volume density of the micro-vessels decreased significantly with age (r=-0.36, P<0.001) and was positively correlated with epidermal thickness (r=0.50, P<0.001). In contrast, the volume density of thick vessels significantly increased with age (r=0.2, P<0.05) and was not significantly correlated with epidermal thickness (r=0.13, P≥0.05). In this study, we proposed a 3D quantification method using OCTA for dermal blood vessels and various vessel metrics, such as vessel volume density. This proposed classification will be beneficial for determining the function of the dermal vasculature and its diagnostic applications.

Abstract P207: Regulation of Fetal-Placental ACE and ACE2 in COVID-19 Exposed Pregnancies Compared to Hypertensive and Healthy Pregnancies

Introduction: Higher risks of preterm birth and fetal growth restriction are observed in COVID-19 pregnancies. The infection mechanism, linked to a potential depletion of the cardioprotective protein ACE2, which serves as a receptor for SARS-CoV-2, could pose additional risks for mothers and fetuses. An ACE2/ACE imbalance, favoring ACE, has been seen in hypertensive (HT) pregnancies and is linked to poor outcomes, including pre-eclampsia. This study aims to assess whether similar changes in ACE and ACE2 regulation in placentas and umbilical cord blood occur in COVID-19 compared to HT and healthy (Ctrl) pregnancies, and whether this imbalance is associated with impaired vascular structure. Methods: A retrospective cohort study recruited 77 pregnancies (25 COVID-19, 16 HT, 36 Ctrl) at Montreal Hospital Sacré-Coeur. Placental infarction was assessed in histological sections, umbilical cord fibrosis by Masson's trichrome staining, and placental ACE2 content by immunohistochemistry. ACE and ACE2 activity were measured by fluorometric assay in umbilical cord plasma. Data are presented as mean 95% CI. Linear regression was used for correlations, Kruskal-Wallis and Mann-Whitney tests for group comparisons. Results: Maternal age, gestational age, and the proportion of male/female fetuses were similar between groups. Ctrl group had lower rates of C-section delivery, obesity, and gestational diabetes compared to COVID-19 and HT pregnancies. Although ACE2 content in placentas was reduced in HT pregnancies, the COVID-19 group had significantly higher content compared to HT and Ctrl pregnancies (23.4 CI=20.4-26.4 vs. 15.5 CI=9.7-21.3 and 17.6 CI=15.1-20.1, respectively, p&lt;0.01). The ACE2/ACE activity ratio in cord blood was significantly reduced in COVID-19 and HT groups compared to Ctrl (3.1 CI=2.4-3.6, 2.5 CI=1.7-3.1, and 4.1 CI=3.5-4.8, p&lt;0.01), indicating an imbalance favoring ACE activity in HT and COVID-19 groups. The ACE2/ACE ratio negatively correlated with umbilical cord fibrosis (slope=-3.1 CI= -6.1 to -0.1, p=0.04) and was significantly lower in placentas with tissue infarction (2.5 CI=1.2-3.8 vs. 4.6 CI=3.8-5.3, p&lt;0.01). Conclusion: HT pregnancies have reduced ACE2 content and an ACE2/ACE activity imbalance in cord blood. COVID-19 pregnancies show a similar imbalance in cord blood but significantly higher ACE2 content in the placenta. This imbalance is associated with structural changes in fetal-placental vessels, suggesting a link to poor pregnancy outcomes.

Four-dimensional endocardial surface imaging with dynamic virtual reality rendering: a technical note.

Open heart surgery requires a proper understanding of the endocardial surface of the heart and vascular structures. While modern four-dimensional (4D) imaging enables excellent dynamic visualization of the blood pool, endocardial surface anatomy has not routinely been assessed. 4D image data were post-processed using commercially available virtual reality (VR) software. Using thresholding, the blood pool was segmented dynamically across the imaging volume. The segmented blood pool was further edited for correction of errors due to artifacts or inhomogeneous signal intensity. Then, a surface shell of an even thickness was added to the edited blood pool. When the cardiac valve leaflets and chordae were visualized, they were segmented separately using a different range of signal intensity for thresholding. Using an interactive cutting plane, the endocardial surface anatomy was reviewed from multiple perspectives by interactively applying a cutting plane, rotating and moving the model. In conclusions, dynamic three-dimensional (3D) endocardial surface imaging is feasible and provides realistic simulated views of the intraoperative scenes at open heart surgery. As VR is based on the use of all fingers of both hands, the efficiency and speed of postprocessing are markedly enhanced. Although it is limited, visualization of the cardiac valve leaflets and chordae is also possible.

MANAGEMENT OF CEREBROVASCULAR ACCIDENT THROUGH PANCHAKARMA THERAPY: A CASE STUDY

Cerebrovascular accident (CVA), the third most common cause of death in developing countries, is the term used to describe episodes of focal brain dysfunction due to focal ischemia or haemorrhage. Acute stroke is characterized most commonly by hemiplegia with or without signs of focal higher cerebral dysfunction that has posed a great problem as far as its management is concerned. Ayurveda can help in such conditions. CVA is quite clearly defined along with its symptoms, prognosis and management in Ayurveda in the context of Pakshaghata as a Vatavyadhi, affecting Madhyama Rogamarga, in which Sira (vascular structures) and Snayu (tendons and ligaments) are mainly affected. A 40-year-old male patient diagnosed with non-hemorrhagic infarct presented with left-side hemiplegia and diplopia was admitted to IPD. Panchakarma procedures, including Snehana, Swedana, Shirodhara, Nasya and Basti, were adopted along with other internal medicines. Assessments were done before and after treatment using the National Institute of Health Stroke Scale (NIH-SS). At the end of the treatment, there was considerable improvement in the subjective and objective clinical features. The observations reveal that Panchakarma procedures can play a vital role in managing conditions like Cerebrovascular accidents by combating general debility with extraocular muscle weakness. The recovery was promising and worth detailing.

Optimizing Neuroimaging Techniques for Enhanced Visualization of Intracranial Aneurysms

Intracranial aneurysms, abnormal dilations of blood vessels in the brain, pose significant health risks, especially when ruptured, leading to conditions such as subarachnoid hemorrhage and stroke. The primary objective of this study is to evaluate the diagnostic accuracy of different computed tomography angiography (CTA) protocols for detecting intracranial aneurysms and to identify methods for optimizing scanning parameters to reduce radiation exposure while ensuring high image quality. Results from the analysis of various CTA protocols revealed that lowering tube voltages (80-120 kV) and milliampere seconds (mAs) effectively reduced radiation exposure without compromising the quality of images. Additionally, the use of advanced reconstruction algorithms, including deep learning techniques, significantly improved the visualization of small vascular structures, thereby enhancing diagnostic accuracy. These findings provide valuable insights for enhancing clinical practices in the fields of neurology and radiology.

Gene inactivation of lysyl oxidase in smooth muscle cells reduces atherosclerosis burden and plaque calcification in hyperlipidemic mice

Background and aimsLysyl oxidase (LOX) catalyzes the crosslinking of collagen and elastin to maintain tensile strength and structural integrity of the vasculature. Excessive LOX activity increases vascular stiffness and the severity of occlusive diseases. Herein, we investigated the mechanisms by which LOX controls atherogenesis and osteogenic differentiation of vascular smooth muscle cells (SMC) in hyperlipidemic mice. MethodsGene inactivation of Lox in SMC was achieved in conditional knockout mice after tamoxifen injections. Atherosclerosis burden and vascular calcification were assessed in hyperlipidemic conditional [Loxf/fMyh11-CreERT2ApoE−/−] and sibling control mice [Loxwt/wtMyh11-CreERT2ApoE−/−]. Mechanistic studies were performed with primary aortic SMC from Lox mutant and wild type mice. ResultsInactivation of Lox in SMCs decreased > 70 % its RNA expression and protein level in the aortic wall and significantly reduced LOX activity without compromising vascular structure and function. Moreover, LOX deficiency protected mice against atherosclerotic burden (13 ± 2 versus 23 ± 1 %, p < 0.01) and plaque calcification (5 ± 0.4 versus 11.8 ± 3 %, p < 0.05) compared to sibling controls. Interestingly, gene inactivation of Lox in SMCs preserved the contractile phenotype of vascular SMC under hyperlipidemic conditions as demonstrated by single-cell RNA sequencing and immunofluorescence. Mechanistically, the absence of LOX in SMC prevented excessive collagen crosslinking and the subsequent activation of the pro-osteogenic FAK/β-catenin signaling axis. ConclusionsLox inactivation in SMC protects mice against atherosclerosis and plaque calcification by reducing SMC modulation and FAK/β-catenin signaling.

Advanced strategies in 3D bioprinting for vascular tissue engineering and disease modelling using smart bioinks

ABSTRACT Advanced three-dimensional (3D) bioprinting technology enables the precise production of complex vascular structures and biomimetic models, driving advancements in tissue engineering and disease mechanism research. At the core of this technology is smart bioink, which is suitable for fabricating biomimetic models that can be vascularised to meet the property requirements of various tissues. Examples of smart bioinks include decellularized extracellular matrix (dECM), photocrosslinkable, reversible, and microgel-based biphasic (MB) bioinks, whose mechanical properties can be tuned through external stimuli. This tuning helps generate high-resolution and complex-shaped vascular networks essential for cell survival and functional maturation. This review explores advanced 3D bioprinting strategies using smart bioinks for spatially controlled and perfusable vascular in vitro models, emphasising the reconstruction of functional vascular structures within 3D bioprinted models. It also discusses challenges and future prospects, suggesting that 3D bioprinted models could serve as alternatives to traditional animal models for disease modelling and drug screening.