Number Of Lymphatic Vessels Research Articles

Enhanced lymphangiogenesis in the left lateral segment of a biopsied liver during portoenterostomy for biliary atresia

PurposeWe investigate the histopathology of the portal vein branches and lymphatic vessels to elucidate the mechanism of atrophy of the left lateral segment (LLS) of the liver in biliary atresia (BA).MethodsLLS and right anterior segment (RAS) liver biopsy samples obtained during Kasai portoenterostomy (KPE) from ten consecutive patients with BA underwent histopathological investigation of the portal vein and lymphatic vessels using double chromogenic immunostaining for CD31/D2-40 and the hepatitis-like findings (HLF) score. Each parameter and clinical data were compared between prognostic groups.ResultsHLF scores in the LLS were always higher than those in the RAS. There was no difference in portal vein and lymphatic vascular morphology, whereas the number of lymphatic vessels was correlated with the fibrotic area of all specimen areas. Left-to-right ratio of the number of lymphatic vessels was correlated with the age at KPE (r = 0.784, p = 0.007) and the pre-KPE CRP value (r = 0.723, p = 0.018).ConclusionsLymphangiogenesis on the LLS compared to the RAS was significantly correlated with the degree of fibrosis and the age at KPE. Further investigation is warranted to clarify the causes of LLS atrophy and lymphangiogenesis relevant to immune dysregulation.

Lymphatic Vessel-Mediated Attenuation of Persistent Macrophage Infiltration Improves Fat Grafting Outcomes in Mice Models.

Persistent macrophage infiltration may lead to adverse consequences, such as calcifications and nodules in fat grafts. Lymphatic vessels, which transport inflammatory cells, are involved in regulating inflammatory responses. Less is known, however, about lymphatic vessels after fat grafting. The aim of this study was to explore the regulation of fat graft survival by lymphatic vessels. A common adipose graft model was constructed to assess the processes responsible for changes in the number of lymphatic vessels in grafts. Adipose tissue samples from C57/BL6 mice and green fluorescent protein-expressing mice were cross-grafted to determine the source of lymphatic vessels. The number of lymphatic vessels in the grafts was increased by treatment with vascular endothelial growth factor C, and the effects of this increase on fat grafting were evaluated. The number of lymphatic vessels was greater in postgrafted fat than in inguinal fat before transplantation, with lymphatic vessels in these grafts gradually transitioning from donor to recipient sources. Lymphatic vessels grew more slowly than blood vessels during early stages of grafting; during later stages, however, the number of blood vessels declined markedly, with more lymphatic vessels than blood vessels being observed 60 days after grafting. Vascular endothelial growth factor C treatment increased graft lymphatics and distant volume retention, while reducing fibrosis and oil sacs. Lymphatic vessels acted as drainage channels for macrophages, with the degree of sustained macrophage infiltration decreasing with increases in the number of lymphatic vessels. Increasing the number of lymphatic vessels is beneficial for fat graft survival, which may be related to a reduction in prolonged macrophage infiltration.

Lymphatic morphology and function in chronic right heart failure due to secondary tricuspid valve regurgitation

BackgroundIn heart failure, the capacity of the lymphatic system dictates symptoms of circulatory congestion. This study aimed at describing structural and functional changes of the lymphatic system in patients with chronic right-sided heart failure. MethodsIndividuals with long-standing severe tricuspid valve regurgitation and symptoms of heart failure were compared with age- gender- and weight-matched controls. Lymphatic structure and function were examined using non-contrast MR lymphangiography and near-infrared fluorescence imaging. Microvascular fluid dynamics and distribution were evaluated using strain gauge plethysmography and bio-impedance. ResultsIn total nine patients and nine controls were included. Lymphatic morphology was unchanged in cases compared to controls with similar thoracic duct diameters 3.1(2.1–3.5) mm vs. 2.0(1.8–2.4) mm (p-value = 0.11), similar lymphatic classifications (p-value 0.34), and an identical number of lymphatic vessels in the legs 6 ± 1 vs. 6 ± 3 vessels/field (p-value = 0.72). Lymphatic function was comparable with contraction frequencies of 0.5 ± 0.2 and 0.5 ± 0.3 /min (p-value = 0.52) and a maximal lymphatic pumping pressure of 60 ± 13 and 57 ± 12 mmHg (p-value = 0.59) for cases and controls respectively. Finally, microvascular capillary filtration, isovolumetric threshold, and fluid distribution were similar between groups (p-value≥0.16 for all comparisons). ConclusionIn this small exploratory study, individuals with severe secondary tricuspid valve regurgitation and right-sided heart failure displayed a largely similar lymphatic anatomy and function. Thoracic duct diameter displayed a trend towards increased size in the patient group. We speculate that cases were indeed stable and optimally treated at the time of examination, and with a lymphatic system largely unaffected by any of the current or prior hemodynamic changes.

Lymphatic Patterns in the Superficial Circumflex Iliac Artery Perforator Flap.

Lymphedema is a chronic condition, characterized by fluid buildup and tissue swelling and is caused by impairment of the lymphatic system. The lymph interpositional flap transfer technique, in which lymph flow is restored with a flap that includes subdermal lymphatic channels, is an option for surgical reconstruction. The superficial circumflex iliac artery perforator (SCIP) flap can be used for this purpose. This study aimed to describe and characterize the lymphatic patterns within the vascular territory of the SCIP flap. This cross-sectional multicenter study involved 19 healthy volunteers aged ≥18 years of both sexes assessing the bilateral SCIP flap zone. Superficial lymphatic patterns were evaluated at 4-, 14-, and 24 minutes after indocyanine green (ICG) lymphography injection. Standardized procedures were implemented for all participants in both hospitals. The linear pattern was predominant bilaterally. The median number of lymphatic vessels and their length increased over time. Most lymphatic vessels in the SCIP flap were oriented toward the inguinal lymph node (ILN). However, the left SCIP zone lymphatic vessels were directed opposite to the ILN. The two sides SCIP zones were not significantly different. The primary direction of the bilateral lymphatic vessels was toward the ILN, although only single-side lymphatic vessels were in the opposite direction. These findings emphasize the importance of assessing lymphatic axiality and coherent lymphatic patterns prior to undertaking the SCIP as an interposition flap, to ensure effective restoration of lymphatic flow.

Metformin eliminates lymphedema in mice by alleviating inflammation and fibrosis: implications for human therapy.

Secondary lymphedema is a chronic, disabling disease impacting over 50% of patients with cancer and lacking effective pharmacological treatment even for early- to mid-disease stages. Metformin reportedly exerts anti-inflammatory and anti-fibrotic effects and is safe, with minimal side effects; We investigated the role of metformin in lymphedema mouse models and examined underlying molecular mechanisms. Male C57BL/6 mice (6-8-week-old; n=15/group) received metformin (300 mg/kg/day) by gavage on day 3 after lymphedema surgery; saline and sham groups were administered the same volume of saline. Hindlimb circumference and tail volume were monitored every two days. On day 28, samples were collected for histological assessment, western blotting, and reverse transcription-quantitative PCR analysis of inflammation, fibrosis, and AMPK expression. AMPK activity was assayed in patients with secondary lymphedema (ISL II) and controls following strict inclusion criteria. Compared with the saline group, the metformin group exhibited hindlimb circumference and tail volume reduced by 469.70% and 305.18%, respectively. on day 28. Dermal thickness was reduced by 38.27% and 72.57% in the hindlimbs and tail, respectively. Metformin decreased CD4+ T cell infiltration by 19.73% and expression levels of interleukin (IL)-4, IL-13, IL-17, and transforming growth factor-β1. Additionally, it lowered collagen I deposition by 33.18%. Compared with the saline group, the number of lymphatic vessels increased by 229.96% in the metformin group. Both the saline group mice and patients with lymphedema showed reduced AMPK activity, while metformin increased p-AMPK expression by 106.12%. Metformin alleviated inflammation and fibrosis and increased lymphangiogenesis in lymphedema mouse models by activating AMPK signaling.

Expression of VEGFR-3 in the lymphatic vessels of the human gum lamina proper within the age and inflammation

Activation of vascular endothelial growth factor VEGFR-3 leads to proliferation, differentiation and migration of lymphatic endothelial cells. The role of this factor in periodontal tissues in normal and inflammatory conditions requires extensive study. The purpose of this study: to study the distribution and expression of VEGFR-3 in the lymphatic vessels of the gum lamina proper during inflammation and the use of a diode laser in young and mature people. Slices of human gum biopsy material were studied by immunohistochemical method. As a result of the research , it was found that in the patients with conditionally healthy periodontal tissues, the number of lymphatic vessels depends on the age and differs in young patients compared to mature patients by 1.2 times. Simultaneouslyбол, it was found that in the control groups, the majority of vessels do not contain VEGFR-3 or have weak receptor expression regardless of age. The tendency to VEGFR-3-mediated increasing of the number of lymphatic vessels during the inflammation is observed only at the age of 41 to 60, however, the intensity of the expression of the VEGF type 3 receptor in chronic gingival inflammation shifts towards the increasing of the vessels with medium and strong VEGFR-3 expression in both groups. As a result of the study, it was found that the tendency to change the number of VEGFR-3-positive vessels is observed only in inflamed gum tissue in patients after 41. Diode laser has a stimulating effect on VEGFR-3-mediated vascular circulation in young patients, while in mature patients, diode laser therapy leads to increase the part of lymphatic vessels with medium and strong expression of the studied receptor, but practically does not affect on the number of detected vessels.

Application of indocyanine green lymphography combined with methylene blue staining in lymphaticovenular anastomosis of lower limb vessels: A prospective study.

Methylene blue (MB) is a conventional lymphatic tracer. We evaluated the application of indocyanine green (ICG) lymphography combined with MB staining in lower limb lymphaticovenular anastomosis (LVA). A total of 49 patients with lower limb lymphedema were selected as the study subjects and divided into the research (n = 27) and control groups (n = 22). The patients were treated with LVA using ICG lymphography combined with MB staining and simple ICG lymphography as the positioning method, respectively. The number of lymphatic vessels anastomosed and the operating time were compared between the groups. Lower Extremity Lymphedema Index (LEL index) and Lymphoedema Functioning, Disability and Health Questionnaire for Lower Limb Lymphoedema (Lymph-ICF-LL) were used as prognostic indices; 6months after LVA, both groups were evaluated for the symptomatic relief of lymphedema. The number of anastomotic lymphatic vessels in the study group was higher than that in the control group (p < .05), and their procedural time was shorter than that in the control group. The two groups had no significant difference in lymphatic anastomosis time (p > .05). The LEL index and Lymph-ICF-LL of the research and control groups at 6-month follow-up after LVA were lower than those before the operation (p < .05). The circumference of the affected limb is reduced after LVA in patients with lower extremity lymphedema with a favorable prognosis. ICG lymphography combined with MB staining has the advantages of real-time visualization and accurate localization.

The significance of the microlymphangiogenesis, microangiogenesis, and combined detection of programmed cell death-1 protein (PD-1)/ki67 in gastric cancer tissues.

To investigate the relationship between the microlymphangiogenesis, microangiogenesis, and combined detection of the programmed cell death-1 protein (PD-1)/ki67 in patients with gastric cancer as well as the disease prognosis. Immunohistochemistry was used to detect the microlymphatic density (MLD) and microvessel density (MVD) in the central and peripheral zones in 92 cases of gastric cancer, along with the number of PD-1- and ki67-positive tumor cells. The central zone of the gastric cancer tissue contained fewer atretic cord-like lymphatic vessels than the peripheral zone, while the peripheral zone contained an increased number of lymphatic vessels compared with the central zone. In most cases, the lumen was also dilated. Compared with the MLD in the peripheral zone, the MLD in central zone was significantly decreased. Compared with the number of PD-1-positive cells in the peripheral zone, the number of PD-1-positive cells in the central zone was significantly decreased, and compared with the number of ki67-positive cells in the peripheral zone. The differences in the microlymphangiogenesis, microangiogenesis, and the number of PD-1- and ki67-positive cells among the different histological types were not statistically significant. The microlymphangiogenesis, microangiogenesis, and PD-1- and ki67-positive cells were significantly decreased in the gastric cancer tissues from the patients in stages T1 and T2 compared with the gastric cancer tissues from the patients in stages T3 and T4. The detection of the MLD and MVD as well as the positive expression of PD-1 and ki67 in gastric cancer tissue are important reference indicators for judging the prognosis of gastric cancer.

Local Adenoviral Delivery of Vascular Endothelial Growth Factor C Induces Lymphangiogenesis in the Conjunctiva in Rabbits

Introduction: The purpose of this study was to determine if conjunctival lymphangiogenesis can be induced using adenoviral delivery of vascular endothelial growth factor C (VEGF-C). Methods: Seventeen New Zealand white rabbits received a subconjunctival injection containing 3.5 × 107 plaque-forming units of an adenoviral vector containing the gene-encoding VEGF-C (Ad-VEGF-C). The contralateral eye was used for control experiment (the same volume of either saline or an empty vector). After 2 weeks, the animals were examined with trypan blue conjunctival lymphangiography, and the eyes were harvested for histology and immunohistochemistry (podoplanin and CD31). Results: Trypan blue conjunctival lymphangiography revealed significantly more extensive conjunctival vessel network in the Ad-VEGF-C group compared with control: 1.35 ± 0.67 versus 0.28 ± 0.17 vessel length/analysed area (p = <0.0001). This finding was confirmed with immunohistochemistry, where a significant increase in the number of lymphatic vessels was found compared to control; 34 ± 9 per mm2 versus 13 ± 8 per mm2 (p = 0.0019). Furthermore, there was a significant increase in lymphatic cross-sectional area; 32,500 ± 7,900 µm2 per mm2 versus 17,600 ± 9,700 µm2 per mm2 (p = 0.0149). Quantification of blood vessels revealed no significant difference in blood vessel density between Ad-VEGF-C and control; 19 ± 9 per mm2 versus 14 ± 8 per mm2 (p = 0.1971). There was no significant difference in total blood vessel area; 13,200 ± 7,600 µm2 per mm2 versus 7,100 ± 3,000 µm2 per mm2 (p = 0.0715). Eyes treated with an adenoviral vector (VEGF-C or empty vector) responded with a reactive cellular response, predominantly lymphocytes, towards the vector. Conclusion: The study demonstrates the feasibility of inducing conjunctival lymphangiogenesis with a single subconjunctival injection of Ad-VEGF-C. Future studies will explore how this can be used with a therapeutic purpose.

Networked lymphatic endothelial cells in a transplanted cell sheet contribute to form functional lymphatic vessels

This study evaluated whether cell sheets containing a network of lymphatic endothelial cells (LECs) promoted lymphangiogenesis after transplantation in vivo. Cell sheets with a LEC network were constructed by co-culturing LECs and adipose-derived stem cells (ASCs) on temperature-responsive culture dishes. A cell ratio of 3:2 (vs. 1:4) generated networks with more branches and longer branch lengths. LEC-derived lymphatic vessels were observed 2 weeks after transplantation of a three-layered cell sheet construct onto rat gluteal muscle. Lymphatic vessel number, diameter and depth were greatest for a construct comprising two ASC sheets stacked on a LEC/ASC (3:2 ratio) sheet. Transplantation of this construct in a rat model of femoral lymphangiectomy led to the formation of functional lymphatic vessels containing both transplanted and host LECs. Further development of this technique may lead to a new method of promoting lymphangiogenesis.

Lymphaticovenular anastomoses training model for multiple stages of lymphedema by using efferent lymphatic plexus of the mesenteric lymph node of rats.

Lymphaticovenular anastomosis (LVA) has transformed lymphedema treatment and has become an important part of the surgical therapy. LVA requires supermicrosurgical skills and unique nontraumatic techniques as the lymphatic vessel diameter of varies with the progression of lymphedema from 0.3 to 0.8 mm. However, even though several supermicrosurgical vessel anastomosis training models have been reported, only few focus on LVA including both various sizes of lymphatic vessels and lymphatic dissection. We report the establishment of a novel in-vivo LVA training model using the rat efferent lymphatic plexus of the mesenteric lymph node. Lymphatic vessels in the efferent lymphatic plexus of the mesenteric lymph node and mesenteric veins of 10 male Wistar rats, 572-850 g, were used for LVA in an intima-to-intima coaptation manner using 12-0 nylon suture with 4-6 stitches in an end-to-end fashion. Postoperative patency was evaluated with indigo carmine blue after completion of anastomosis. Diameters of lymphatic vessels in the plexus and recipient veins were measured. The diameters of lymphatic vessels in efferent lymphatic plexus of the mesenteric lymph nodes and mesenteric veins used as recipients were measured in all 10 male rats. The mean number of lymphatic vessels included in efferent lymphatic plexus of the mesenteric lymph nodes was 7.5 (range, 5-11) and the mean diameter of the lymphatic vessels was 0.34 mm (range, 0.1-1.2 mm). The mean diameter of lymphatic vessels used for LVA was 0.46 mm (range, 0.25-0.7 mm). The mean diameter of the recipient veins was 0.49 mm (range, 0.35-0.7 mm). The postoperative patency rate after LVA was 100% (10/10). We reported the establishment of LVA model involving the use of the efferent lymphatic plexus of the mesenteric lymph node and mesenteric veins in rats.

Cutaneous vascular structure and perfusion in patients with chronic plaque psoriasis.

Vascular dysfunction is a significant contributor to the pathophysiology of psoriasis. Some individuals have variation within the gene for vascular endothelial growth factor-A (VEGF-A), which confers an increased risk of developing psoriasis and having a severe disease phenotype, and may determine responsiveness to treatment. To determine whether patients with psoriasis have alterations in cutaneous microvascular anatomy and physiology due to expression of VEGF and whether laser Doppler imaging has utility in the assessment of this. Twelve adult volunteers with Type 1 chronic plaque psoriasis underwent laser Doppler imaging of plaque and uninvolved skin. Skin biopsies were taken from the areas imaged for immunohistochemistry, including blood and lymphatic vessel markers, and VEGF-A isotype analysis (VEGF-A121, VEGF-A165 and VEGF-D). Venous blood was collected for DNA extraction, VEGF-A genotyping and peripheral blood mononuclear cell culture. Mean blood vessel area (P < 0·01), number of blood vessels (P < 0·001), number of lymphatic vessels (P < 0·001) and blood flow (P < 0·001) was significantly increased in psoriasis plaques, as was expression of VEGF-A121 (P < 0·01), VEGF-A165 (P < 0·04) and VEGF-D (P < 0·01). Blood flow within psoriasis plaques was independent of their increased vascularity (P < 0·01) and may be associated with baseline productivity of VEGF. The number of blood vessels within uninvolved skin in patients with psoriasis was associated with the VEGF-A (rs833061) genotype (P = 0·01), in a relationship suggesting an allele dosing effect. Noninvasive imaging of blood flow may help determine the cutaneous vascular signature for individual patients. This may be a useful prognostic indicator of psoriasis susceptibility and severity, and thus support selection of treatments.

Hydrogen Sulfide Attenuates Lymphedema Via the Induction of Lymphangiogenesis Through a PI3K/Akt-Dependent Mechanism.

Background Accumulating evidence suggests that hydrogen sulfide ( H2S ), an endogenously produced gaseous molecule, plays a critical role in the regulation of cardiovascular homeostasis. However, little is known about its role in lymphangiogenesis. Thus, the current study aimed to investigate the involvement of H2S in lymphatic vessel growth and lymphedema resolution using a murine model and assess the underlying mechanisms. Methods and Results A murine model of tail lymphedema was created both in wild-type mice and cystathionine γ-lyase-knockout mice, to evaluate lymphedema up to 28 days after lymphatic ablation. Cystathionine γ-lyase-knockout mice had greater tail diameters than wild-type mice, and this phenomenon was associated with the inhibition of reparative lymphangiogenesis at the site of lymphatic ablation. In contrast, the administration of an H2S donor, diallyl trisulfide, ameliorated lymphedema by inducing the formation of a considerable number of lymphatic vessels at the injured sites in the tails. In vitro experiments using human lymphatic endothelial cells revealed that diallyl trisulfide promoted their proliferation and differentiation into tube-like structures by enhancing Akt (protein kinase B) phosphorylation in a concentration-dependent manner. The blockade of Akt activation negated the diallyl trisulfide-induced prolymphangiogenic responses in lymphatic endothelial cells. Furthermore, the effects of diallyl trisulfide treatment on lymphangiogenesis in the tail lymphedema model were also negated by the inhibition of phosphoinositide 3'-kinase (P13K)/Aktsignaling. Conclusions H2S promotes reparative lymphatic vessel growth and ameliorates secondary lymphedema, at least in part, through the activation of the Akt pathway in lymphatic endothelial cells. As such, H2S donors could be used as therapeutics against refractory secondary lymphedema.

Characterization of the sex-specific pattern of angiogenesis and lymphangiogenesis in aortic stenosis.

ObjectiveWe aim to analyze sex-related differences in angiogenesis and lymphangiogenesis in aortic valves (AVs) and valve interstitial cells (VICs) from aortic stenosis (AS) patients.Approach and ResultsTotally 230 patients (59% men) with severe AS undergoing surgical valve replacement were recruited. The density of total neovessels was higher in AVs from men as compared to women. Both small and medium neovessels were more abundant in men's AVs. Accordingly, male AVs exhibited higher CD31 and VE-cadherin expressions. The levels of the pro-angiogenic markers, such as vascular endothelial growth factor (VEGF)-A, VEGF receptor (VEGFR)1, VEGFR2, insulin-like growth factor-binding protein-2 (IGFBP-2), interleukin (IL)-8, chemerin, and fibroblast growth factor (FGF)-7, were increased in AVs from men. Transforming growth factor-β expression was higher in male AVs. The expression of antiangiogenic molecules thrombospondin (Tsp)-1, endostatin, and CD36 was upregulated in male AVs, although the levels of Tsp-2, IL-4, IL-12p70, and chondromodulin-1 were similar between both sexes. The number of lymphatic vessels and the expression of the lymphangiogenic markers Lyve-1 and D2-40 was higher in men's AV as well as VEGF-C, VEGF-D, and VEGFR3. Multivariate analyses adjusted for confounders further validated the sex-dependent expression of these targets. VICs isolated from men's AVs secreted higher amounts of the pro-angiogenic factors, VEGF-A, VEGFR1, IGFBP-2, and FGF-7, as well as the pro-lymphangiogenic factors, VEGF-C, VEGF-D, and VEGFR3, than women without changes in antiangiogenic markers.ConclusionOur data show that aberrant angiogenic and lymphangiogenic cues are over-represented in male AVs. Importantly, the VIC is a relevant source of multiple morphogens involved in angiogenesis and lymphangiogenesis likely endowing the AV of men with the predominant calcific AS phenotypes.

Photoacoustic lymphangiography is a possible alternative for lymphedema staging

ObjectivePhotoacoustic imaging is a new technique that uses the photoacoustic effect. In photoacoustic lymphangiography (PAL), images of the lymphatic vessels can be visualized using light-absorbing contrast agents. In the present study, we investigated the efficacy of PAL for lymphedema staging. MethodsWe performed PAL of the lower extremities and examined the clinical implications of using PAL for staging lymphedema by comparing the PAL images with those obtained using lymphoscintigraphy. Of 47 patients with lymphedema who had been outpatients or hospitalized at our institution between May 2018 and September 2020 and had undergone PAL, 15 with 18 limbs who had also undergone lymphoscintigraphy were included in the present study. The lymphoscintigraphy findings were classified using the Maegawa classification. We also investigated whether PAL could clearly visualize the lymphatic vessels and concisely reflect the disease state by counting the number of lymphatic vessels observed using PAL. ResultsThe PAL findings were categorized into three groups: collecting lymphatic vessels, dermal backflow (DBF), and no lymphatic vessels. The collecting lymphatic vessels group corresponded to types 2 and 3 in the Maegawa classification; DBF corresponded to types 3 and 4, and the no lymphatic vessels group corresponded to type 4. The number of lymphatic vessels visualized using PAL was similar to that with lymphoscintigraphy. As the disease progressed, the number of lymphatic vessels observed decreased, increased DBF was detected, and, eventually, the lymphatic vessels were not visible, corresponding to the general changes observed via lymphoscintigraphy with stage progression. ConclusionsThe findings from PAL and lymphoscintigraphy tended to correspond, suggesting that PAL could be useful for lymphedema staging.

Angioprotective and Follicle-Stimulating Effects of Administration of Bone Marrow Mesenchymal Stromal Cells in Chronic Inflammation of Internal Reproductive Organs.

Induced inflammation of reproductive organs in female Wistar rats was associated with an increase in the diameters of arteries and veins and number of blood vessels in the ovary medulla in combination with an increase in the number of lymphatic vessels; these changes were accompanied by reduction of the ovarian reserve and number of yellow bodies. Intravenous and submucosal injection of bone marrow multipotent mesenchymal stromal cells (BМ-ММSC) led to further increase in the diameters of arteries and veins and number of primordial and primary follicles. The injection of conditioned medium of BМ-ММSC cultures generally produced the same effects, which could demonstrate the secretory mechanisms of their influence on local angiogenesis and folliculogenesis.

The Peripheral Lymphatic System Is Impaired by the Loss of Neuronal Control Associated with Chronic Spinal Cord Injury

Spinal cord injury (SCI) is associated with venous vascular dysfunction below the level of injury, resulting in dysregulation of tissue fluid homeostasis in afflicted skin. The purpose of this study was to determine whether loss of neuronal control in chronic SCI also affects the skin lymphatic system. Morphology of lymphatics was characterized by immunohistochemistry and lymphatic gene expression profiles determined by DNA microarray analysis. In SCI, skin lymphatic function appeared to be impaired, because the ratio of functionally dilated versus collapsed lymphatic vessels was decreased 10-fold compared with control. Consequently, the average lumen area of lymphatic vessels was almost halved, possibly due to the known impaired connective tissue integrity of SCI skin. In fact, collagenases were found to be overexpressed in SCI skin, and dermal collagen structure was impaired. Molecular profiling also suggested an SCI-specific phenotype of increased connective tissue turnover and decreased lymphatic contractility. The total number of lymphatic vessels in SCI skin, however, was doubled, pointing to enhanced lymphangiogenesis. In conclusion, these data show, for the first time, that lymphatic function and development in human skin are under neuronal control. Because peripheral venous and lymphatic vascular defects are associated with disturbed fluid homeostasis, inappropriate wound healing reactions, and impaired skin immunity, they might contribute to the predisposition of afflicted individuals to pressure ulcer formation and wound healing disorders.

Occurrence of Lymphangiogenesis in Peripheral Nerve Autografts Contrasts Schwann Cell-Induced Apoptosis of Lymphatic Endothelial Cells In Vitro.

Peripheral nerve injuries pose a major clinical concern world-wide, and functional recovery after segmental peripheral nerve injury is often unsatisfactory, even in cases of autografting. Although it is well established that angiogenesis plays a pivotal role during nerve regeneration, the influence of lymphangiogenesis is strongly under-investigated. In this study, we analyzed the presence of lymphatic vasculature in healthy and regenerated murine peripheral nerves, revealing that nerve autografts contained increased numbers of lymphatic vessels after segmental damage. This led us to elucidate the interaction between lymphatic endothelial cells (LECs) and Schwann cells (SCs) in vitro. We show that SC and LEC secretomes did not influence the respective other cell types’ migration and proliferation in 2D scratch assay experiments. Furthermore, we successfully created lymphatic microvascular structures in SC-embedded 3D fibrin hydrogels, in the presence of supporting cells; whereas SCs seemed to exert anti-lymphangiogenic effects when cultured with LECs alone. Here, we describe, for the first time, increased lymphangiogenesis after peripheral nerve injury and repair. Furthermore, our findings indicate a potential lymph-repellent property of SCs, thereby providing a possible explanation for the lack of lymphatic vessels in the healthy endoneurium. Our results highlight the importance of elucidating the molecular mechanisms of SC–LEC interaction.

Podoconiosis: Clinical spectrum and microscopic presentations

Podoconiosis is a skin Neglected Tropical Disease (skin NTD) that causes lymphoedema, and affects barefooted subsistence farmers in some tropical countries. The clinical presentation and histopathologic correlates of podoconiosis have been understudied. Here, we systematically document the clinical and histopathologic spectrum of podoconiosis. This is a cross-sectional study in Durbete, Ethiopia from February 2018 to October 2019. Dermatologists performed a patient history, physical examination, filariasis test strip, and skin biopsy for histopathologic examination. The results were summarised and a descriptive statistical analysis and Wilcoxon rank sum test with continuity correction was done. We recruited 289 patients for the study, 178 (61.6%) had stage 1 or 2 podoconiosis, and 111(38.4%) stage 3 to 5 podoconiosis. 188 (64.1%) had a family history of podoconiosis. In 251 (86.9%) patients, both legs were affected by podoconiosis and in 38 (13.1%) only one leg was affected. 220 (77.5%) patients had warty lesions, 114 (39.4%) had nodules. The median number of episodes of Acute Dermato-Lymphangio-Adenitis (ADLA) reported by the patients in the last three months was 2 (interquartile range (IQR) 1-4). Increased episodes of ADLA were significantly associated with stage 3-5 podoconiosis (P = 0.002), while burning pain in the feet was more common in stage 1 or 2 podoconiosis. Stage 3-5 disease was histopathologically characterised by epidermal and dermal thickening, verrucous acanthosis, inflammatory cell infiltrates (predominantly lymphoplasmacytic), dilated and ectatic and a reduced number of lymphatic vessels, eccrine ductal hyperplasia, and sclerosis such as thickened collagen bundles. We provide a detailed description of the different clinical patterns, associated clinical findings and the histopathologic spectrum of podoconiosis at different stages of the disease. Our observations should serve as a guide to classifying patients with podoconiosis for prognostic assessment and treatment decision.

Use of Microscope-Integrated Near-Infrared Fluorescence for Enhancing Deep Lymphatic Vessel Detection during Supermicrosurgical Lymphaticovenous Anastomosis: A Longitudinal Cohort Study.

The default setting of microscope-integrated near-infrared fluorescence (MINIRF) using indocyanine green for locating superficial lymphatic vessels during lymphaticovenous anastomosis was limited to less than or equal to 70 percent intensity. The authors investigated whether maximizing the MINIRF intensity setting could increase the number of deep lymphatic vessels being found, thereby increasing the total number of lymphatic vessels for lymphaticovenous anastomosis. This longitudinal cohort study enrolled 94 patients (86 female and eight male patients) with lower limb lymphedema. Superficial lymphatic vessels were identified with the MINIRF default setting, before maximal intensity was used for deep lymphatic vessel detection. Primary/secondary endpoints included the number of superficial and deep lymphatic vessels identified. No control was used. Demographic data, intraoperative findings [including superficial and deep (indocyanine green-enhanced and non-indocyanine green-enhanced) lymphatic vessels], and severity of lymphosclerosis were recorded. Data in three regions of the lower limb (i.e., foot/above ankle, below knee, and thigh) were compared. A total of 481 lymphatic vessels were identified, comprising 260 superficial and 221 deep lymphatic vessels. The median number of lymphatic vessels found per patient was five (interquartile range, four to six), and the median lymphatic vessel size was 0.63 mm (interquartile range, 0.5 to 0.8 mm). No difference was found in number (p = 0.360), size (p = 0.215), or severity of lymphosclerosis (p = 0.226) between the overall superficial and deep lymphatic vessels in the three lower limb regions. Deep lymphatic vessel detection can be aided by maximizing MINIRF intensity. These deep lymphatic vessels are comparable to superficial lymphatic vessels in number, size, and functionality, making them potentially valuable for lymphedema improvement. Diagnostic, II.