Animal models of diseases in particular, the mice, are considered to be the cornerstone for translational research in immunology. The aim of the present study is to model the geometry and analyze the network structure of murine lymphatic system (LS). The algorithm for building the graph model of the LS makes use of anatomical data. To identify the edge directions of the graph model, a mass balance approach to lymph dynamics based on Hagen-Poiseuille equation is applied. It is the first study in which a geometric model of the murine LS has been developed and characterized in terms of its structural organization and the lymph transfer function. Our study meets the demand for quantitative mechanistic approaches in the growing field of immunoengineering to utilize or exploit the lymphatic system for immunotherapy.

Neck lymphangiomas are rare, benign congenital malformations that predominate in childhood. Most present before the age of two. There are no risk factors related to sex, ethnic origin or predominance on either side, and they can occur in any anatomical location, although the most frequent is in the head and neck. The clinical presentation depends on its location. The most frequent symptom is the existence of a painless mass that grows slowly. Available therapeutic tools include surgery, systemic treatment, and injection of sclerosing agents.

(1) Background: Melanoma is the most aggressive tumor located at the skin level and the man-agement of this pathology requires a correct staging as well as a modern oncological treatment, adapted to each patient. The main objective of the study is to determine the variability of lymphatic drainage in the case of melanomas located on the trunk; (2) Methods: This retrospective study in-cluded 62 cases of melanoma located on the trunk operated between July 2019 and March 2023 in which SLNB was performed and a total of 84 lymph node were excised; (3) Results: Patients had an average age of 54.5 years old, while melanomas had a mean Breslow index of 2.3 mm. The distri-bution of trunk melanomas was: upper trunk 54 cases, lower trunk 30 cases (64.3 % vs. 35.7%). The type of anesthesia chosen was general anesthesia in 53 cases, respectively spinal anesthesia in 9 cases (85.5% vs. 14.5%, p<0.001). The number of sentinel lymph nodes was 54 for melanomas lo-cated on the upper trunk, 8 cervical and 46 axillary, respectively 30 sentinel lymph nodes in cases of melanomas of the lower trunk, 16 at the axillary level and 14 at the inguinal level; (4) Conclusions: Lymph node involvement in melanoma represents an important prognostic factor and the different lymphatic drainage pathways in relation to the location of the primary tumor represents an im-portant objective in the management of this pathology.

Lymphatic filariasis (LF) is a vector-borne disease caused by parasitic helminths and constitutes a serious public health issue in tropical regions. According to the World Health Organization (WHO), infected cases in Southeast Asia constitute 50% of the estimated 120 million infections globally. In Indonesia, LF is caused by all filarial species, and in 2018, 236 districts from a total of 514 districts in the entire country were declared as endemic areas. The global program to eliminate filariasis has been running for the last 19 years and has been conducted as a full national initiative for the last 8 years in Indonesia. The study describes the surveillance of LF cases and prevalence in Indonesia for the past 17 years (2001-2017) – during the global and national LF elimination programs-, using national registry-based data. The data demonstrates that the national program has been largely effective in the areas it has been active the longest, while there are provinces lagging behind in the successful suppression of LF. The high geographical fragmentation of the country with the associated ecological parameters relating to LF incidence, likely play an important role in maintaining the highly varied incidence rate across Indonesia.

Neuroendocrine tumors develop from systemic endocrine and nerve cells, and their occurrence has increased recently. Since these tumors are heterogeneous, pathological classification has been based on the affected organ. In 2019, the World Health Organization introduced a change that is expected to influence neuroendocrine tumor research, as gastroenteropancreatic neuroendocrine tumors are now included within a unified classification. In this retrospective study, we aimed to investigate the characteristics (e.g., lymph node metastases, all other metastases) of gastroenteropancreatic neuroendocrine tumors using this new classification in 50 cases. Tumor size, depth, MIB-1 index, lymphatic invasion, venous invasion, and neuroendocrine tumor grade were significantly correlated with lymph node metastasis and all other metastases. Venous invasion was more strongly correlated with lymph node metastasis and all other types of metastasis than with lymphatic invasion. Identification rates for lymphatic invasion were considered lower because of structural problems such as lymphatic vessels being much thinner than veins. However, venous invasion was considered effective in compensating for the low rate of identification in cases of lymphatic invasion. In future research, a unified classification and standardized framework for assessment will be important when analyzing the characteristics of neuroendocrine tumors, and large-scale studies are required.

Following the first triple-drug MDA for lymphatic filariasis in Samoa in 2018, unexpected persistence of Mf-positivity in 18 (15%) of 121 antigen-positive persons was observed in a nationwide household survey 1-2 months later, raising concerns about MDA efficacy. In 2019, a monitored treatment study was done before and 7 days after directly observed weight-based treatment. Mf presence and density were evaluated using 1 mL membrane filtered venous blood, and 60uL thick blood films on slides prepared from venous or fingerprick blood. All 14 participants were still Mf positive on filters from venous blood pre-treatment samples, but two were negative by slide made from the same samples. Mf were cleared completely by day 7 in 12 of 13 participants followed up, and by day 30 in the remaining participant. Filtered blood using EDTA samples (to reduce clumping of Mf) is preferred over slides alone for improving the likelihood of detecting Mf and estimating their density. The triple-drug MDA strategy was effective at clearing Mf by day 30 when given and taken at the correct dose.

The microbiome is critical to the function of higher organisms and the gastrointestinal microbiome in chief among them. We do not know what impact the spaceflight GI microbiome has on organismal health in the absence of other confounding factors. We used a fecal transplant model to address this question and we found that we can recapitulate some of the functional aspects of the spaceflight microbiome on the ground but the impact on organismal health was ambiguous showing neither a defined improvement nor a impairment to lymph transport, growth, or immune populations. Histidine treatment was able to alter some of the functional aspects of the microbiome. Overall it we can conclude that the spaceflight microbiome is not pathological but has distinct impacts on organismal health.

Lymphatic filariasis (LF), also commonly known as elephantiasis, is a neglected tropical disease (NTD) caused by filarial parasites. The disease is transmitted by a bite from infected mosquitoes. The bites of these infected mosquitoes deposit filarial parasites, Wuchereria or Brugia whose predilection site is the lymphatic system. The damage to the lymph system causes swelling in the legs, arms, and genitalia. A mapping survey conducted between 2003 and 2010 determined LF that LF was endemic in Zambia in 96 out of 116 districts. Elimination of LF is known to be possible by stopping the spread of the infection through large-scale preventive chemotherapy. Therefore, mass drug administration (MDA) with diethylcarbamazine citrate (DEC) (6 mg/kg) and Albendazole (400 mg) for Zambia has been conducted and implemented in all endemic districts with five effective rounds. Post-MDA pre-transmission assessment survey (pre-TAS) was conducted between 2021 and 2022 in 80 districts to determine the LF prevalence rate. We conducted a cross-sectional seroprevalence study involving 600 participants in each Evaluation Unit (EU) or each district. The study sites (sentinel and spot-check sites) were the districts that were the Implementation Unites (IUs) where MDA, preventive chemotherapy against LF was conducted. These included 80 districts from the 9 provinces. A total of 47,235 people from sentinel and spot-check locations were tested. Of these, valid tests were 47,052 of which 27,762 (59%) were females and 19,290 (41%) were males. The survey revealed in the 79/80 endemic district a prevalence of Wb anti-gens of 0.14% and 0.0% prevalence of microfilariae. All the surveyed districts had an optimum prevalence of less than 2 percent, except for Chibombo district. The majority of participants that tested positive for Wb Ag were those that had 2, 3, and 4 rounds of MDA. Surprisingly, individuals that had 1 round of MDA were not found to have circulating antigens of Wb. The study showed that all the surveyed districts except for Chibombo, passed Pre-TAS. This further implies that there is a need to conduct a TAS in these districts in order to decide whether to stop MDA or not. Keywords: Lymphatic Filariasis; pre-TAS; Prevalence; Antigenaemia; Microfilariae; Zambia

Peripheral nerve injuries pose a major clinical concern world-wide, and functional recovery after segmental peripheral nerve injury is often unsatisfactory, even in case of autografting. Although it is well established that angiogenesis plays a pivotal role during nerve regeneration, the influence of lymphangiogenesis is strongly underinvestigated. 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 do 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 to elucidate the molecular mechanisms of SC-LEC interaction.

Under inflammatory conditions including lymphatic disorders, bone marrow-derived myeloid cells often express lymphatic endothelial cell (LEC) markers called LEC progenitor cells, which extend lymphatic vessels by fusing with existing lymphatic vessels. However, studies on the mechanism of lymphatic regeneration using three-dimensional images of lymphatic structures are limited. In this study, scanning electron microscopy (SEM) was used to observe the three-dimensional structure of lymphangiogenesis in a mouse model of secondary lymphedema. The model was established in C57BL/6J mice via circumferential incision in the inguinal region of the left hind limb. Skin samples were obtained from the lymphedema region on days 2, 5, and 8 after surgery. To determine lymphatic vessel positions using SEM analysis, we detected anti-lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) immunoreactivity in serial sections and overlaid them during SEM observation. On days 2 and 5, spherical cells, probably myeloid cells, were attached and fused to the LYVE-1-positive lymphatic vessel walls. On day 8, spherical cells were converted to string-shaped cells, forming a new lymphatic vessel wall resembling an intraluminal pillar. Our results show the three-dimensional lymphatic structures formed during lymphatic regeneration.

Without protective and/or therapeutic agents the SARS-CoV-2 infection known as coronavirus disease 2019 (COVID-19) is quickly spreading worldwide. It has surprising transmissibility potential, since it could infect all ages, gender, and human sectors. It attacks respiratory, gastrointestinal, urinary, hepatic, and endovascular systems and can reach the peripheral nervous system (PNS) and central nervous system (CNS) through known and unknown mechanisms. The reports on the neurological manifestations and complications of the SARS-CoV-2 infection are increasing exponentially. Herein, we enumerate seven candidate routes, which the mature or immature SARS-CoV-2 components could use to reach the CNS and PNS, utilizing the within-body crosstalk between organs. The majority of SARS-CoV-2 infected patients suffer from some neurological manifestations (e.g., confusion, anosmia, and ageusia). It seems that although the mature virus did not reach the CNS or PNS of the majority of patients, its unassembled components and/or the accompanying immune-mediated responses may be responsible for the observed neurological symptoms. The viral particles and/or its components have been specifically documented in endothelial cells of lung, kidney, skin, and CNS. This means that the blood-endothelial-barrier may be considered as the main route for SARS-CoV-2 entry into the nervous system, with the barrier disruption being more logical than barrier permeability, as evidenced by postmortem analyses.

The lymphatic system of the brain meninges and head plays a crucial role in the clearance of amyloid-β protein (Aβ), a peptide thought to be pathogenic in Alzheimer’s disease (AD), from the brain. The development of methods to modulate lymphatic clearance of Aβ from the brain coild be a revolutionary step in the therapy of AD. The opening of the blood-brain barrier (OBBB) by focused ultrasound is considered as a possible tool for stimulation of clearance of Aβ from the brain of humans and animals. Here, we propose an alternative method of non-invasive music-induced OBBB that is accompanied by the activation of clearance of fluorescent Aβ (Fαβ) from the mouse brain. Using confocal imaging, fluorescence microscopy and magnetic resonance tomography, we clearly demonstrate that OBBB by music stimulates the movement of Fαβ and Omniscan in the cerebrospinal fluid and lymphatic clearance of Fαβ from the brain. We propose the extended detrended fluctuation analysis (EDFA) as a promising method for the identification of OBBB markers in the electroencephalographic (EEG) patterns. These pilot results suggest that music-induced OBBB and the EDFA analysis of EEG can be a non-invasive, low cost, labelling free, clinical perspective and completely new approach for the treatment and monitoring of AD.

Abstract: Viremia in coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is often only discussed in passing and there are very few references detailing its structural mechanisms. In addition to viremia in the classic closed cardiovascular system, the lymphatic system is discussed in relation to a possible “lympho-viremia”. The cells that comprise each of these separate but interacting systems will be examined and include endothelial cells, erythrocytes, leukocytes (monocytes/monocyte-derived macrophages and resident tissue macrophages) (lymphocytes) (neutrophils) and thrombocytes -platelets. The SARS-CoV-2 virus has been identified in multiple extrapulmonary target organs at autopsy in those with severe COVID-19 requiring intensive care. Vulnerable COVID-19 patients may suffer from multiple storms including viral/virion storm, redox storm, cytokine storm and thrombo-embolic storm. Therefore, it is important that the possible mechanisms of viremia be explored in greater detail and how these mechanisms might affect intravascular blood components, extracellular tissue interstitium and organ structural remodeling and function. While the co-morbidity of T2DM does not increase the risk of acquiring COVID-19, it is commonly accepted that T2DM increases the risk for COVID-19 admissions to hospitals, assisted ventilation, morbidity and mortality. Importantly, the co-existence of T2DM and COVID-19 may have synergistic detrimental outcomes.

Acute kidney injury (AKI), especially if recurring represents a risk factor for future chronic kidney disease. In intensive care units, increased intraabdominal pressure is well-recognized as a significant contributor of AKI. However, the importance of transiently increased intra-abdominal pressures procedures is less commonly appreciated during laparoscopic surgery, the use of which has rapidly increased over the last few decades. Unlike the well-known autoregulation of the renal cortical circulation, medulla perfusion is modulated via partially independent regulatory mechanisms and strongly impacted by changes in venous and lymphatic pressures. In our review paper, we will provide a comprehensive overview of this evolving topic, covering a broad range from basic pathophysiology up to and including current clinical relevance. Key regulators of oxidative stress such as ischemia-reperfusion injury, the activation of inflammatory response and humoral changes interacting with procedural pneumoperitoneum formation and AKI risk will be recounted. Moreover, we present an in-depth review of the interaction of pneumoperitoneum formation with general anesthetic agents and animal models of congestive heart failure. A better understanding of the relationship between pneumoperitoneum formation and renal perfusion will support basic and clinical research, leading to improved clinical care and collaboration among specialists.

COVID-19 and long COVID-19 vulnerabilities may be caused indirectly by albumin binding deficiency (ABD) which can be corrected by the correct administration of human serum albumin (HSA). The liver is the primary site of nutrient regulation and fluid volume maintenance, control of both is by changes to albumin concentration. In healthy subjects the HSA lymphatic nutrient pump (HSALNP) ensures continual pumping of nutrients from the liver are appropriately distributed to organs. Nutrients are delivered to cells according to the availability of binding to HSA. The HSALNP therefore maintains the correct nutrients and colloidal pressure balance in all tissues independently. In unhealthy tissues, following COVID-19 infection, the passage of HSA/nutrients through the interstitial spaces and lymph will be impeded. Fluid therapy into the periphery leads to dilution of essential nutrients attached to the protein-carriers such as albumin. The levels of albumin being charged by the liver with nutrients is critical in maintaining immune stability by maintaining nutrient support and colloidal pressure of cellular structures. The site of HSA binding by the liver is of great importance and direct infusion of albumin into the Hepatic Portal Vein is the most appropriate method of maintaining colloid pressure and cellular nutrient levels.

A surgical technique aimed at rerouting aqueous humor (AH) outflow from the anterior chamber to the suprachoroidal space (SCS) without performing surgical cyclodialysis was developed to decrease intraocular pressure (IOP) in glaucoma patients. The surgical outcomes of the technique were retrospectively analyzed in fifty-eight patients. At 6, 12, and 24 months, the mean IOP decreased from 27.8±8.3 to 14.95.0 mmHg, median 15.0 (25th percentile (p25 )13.0; 75th percentile (p75) 18.0), and 15.23.3 mmHg; hypotensive medication use reduced from median (p25; p75) 3 (2; 3) to 0 (0; 2), 0 (0; 2), and 0 (0; 1.5), and complete success was achieved in 62.8%, 51.2%, and 32.5% cases, with partial success in 28.4%, 44.2%, and 62.5% cases, respectively. Eight cases (13.8%) presented unsatisfactory outcomes. Intra- and postoperative complications were few and manageable. No bleb formation was observed in any of the cases. In 50% of cases, conjunctival lymphatic vessels (CLVs) developed following surgery in superior quadrants. The technique is safe and effective in providing a long-term decrease in IOP and hypotensive medication use. It was hypothesized in this study that the IOP decrease occurred as a result of enhanced AH outflow from the SCS to CLVs through intrascleral microchannels connecting the SCS to CLVs.