Background: Lymphedema, the accumulation of interstitial fluid caused by poor lymphatic drainage, is a progressive and permanent disease with no curative treatment. Several studies have evaluated cell-based therapies in secondary lymphedema, but no meta-analysis has been performed to assess their efficacy.Methods: We conducted a systematic review and meta-analysis of all available preclinical and clinical studies, with assessment of their quality and risk of bias.Results: A total of 20 articles using diverse cell types were selected for analysis, including six clinical trials and 14 pre-clinical studies in three species. The meta-analysis showed a positive effect of cell-based therapies on relevant disease outcomes (quantification of edema, density of lymphatic capillaries, evaluation of the lymphatic flow, and tissue fibrosis). No significant publication bias was observed.Conclusion: Cell-based therapies have the potential to improve secondary lymphedema. The underlying mechanisms remain unclear. Due to relevant heterogeneity between studies, further randomized controlled and blinded studies are required to substantiate the use of these novel therapies in clinical practice.
11 January 2022 in IEEE Journal of Biomedical and Health Informatics
Perinatal asphyxia represents a major medical disorder and is related to around a fourth of all neonatal deaths worldwide. Specific thresholds for lactate or pH levels define the gold standard for detecting hypoxic-ischemic events as physiological abnormalities. In contrast to current gold standard, we analyze the systemic picture, represented by the whole set of biochemical parameters from blood gas analysis, by multiparametric machine learning algorithms. In a swine model with 22 objects, we investigate the impact of neonatal hypoxic-ischemic encephalopathy on 18 individual physiological parameters. In a first approach, we study the statistical significance of individual parameters by univariate analysis methods. In a second approach, we take the most relevant parameters as input for the development of predictive models by different hybrid and non hybrid classification algorithms. The predictive power of our multiparametric models outperforms by far the limited performance of pH and lactate as reliable indicators, despite strong correlation with hypoxic-ischemic events. We have been able to detect hypoxic-ischemic events even one hour after the episode, with accuracies close to 100% in contrast to pH or lactate-based diagnosis with 62% and 78%, respectively. By all machine learning algorithms, lactate is recognized as the main contributor due to its longer-term evidence of hypoxia-ischemia episodes. However, substantial improvement of the diagnosis is achieved by predictions based on a systemic picture of different physiological parameters. Our results prove the potential applicability of our method as a support tool for decision-making that will allow obstetricians to identify hypoxic ischemic episodes more accurately during labor.
The hemodynamic, metabolic, and biochemical changes produced during the transition from fetal to neonatal life may be aggravated if an episode of asphyxia occurs during fetal life. The aim of the study was to examine regional cerebral blood flow (RCBF), histological changes, and cerebral brain metabolism in preterm lambs, and to analyze the role of oxidative stress in the first hours of postnatal life following severe fetal asphyxia. Eighteen chronically instrumented newborn lambs were randomly assigned to either a control group or the hypoxic–ischemic (HI) group, in which case fetal asphyxia was induced just before delivery. All the animals were maintained on intermittent positive pressure ventilation for 3 h after delivery. During the HI insult, the injured group developed acidosis, hypoxia, hypercapnia, lactic acidosis, and tachycardia (relative to the control group), without hypotension. The intermittent positive pressure ventilation transiently improved gas exchange and cardiovascular parameters. After HI injury and during ventilatory support, there continued to be an increased RCBF in inner regions among the HI group, but no significant differences were detected in cortical flow compared to the control group. Also, the magnitude of the increase in TUNEL positive cells (apoptosis) and antioxidant enzymes, and decrease of ATP reserves was significantly greater in the brain regions where the RCBF was not higher. In conclusion, our findings identify early metabolic, histological, and hemodynamic changes involved in brain damage in premature asphyxiated lambs. Such changes have been described in human neonates, so our model could be useful to test the safety and the effectiveness of different neuroprotective or ventilation strategies applied in the first hours after fetal HI injury.
Surveillance of physiological parameters of newborns during delivery triggers medical decision‐making, can rescue life and health, and helps avoid unnecessary cesareans. Here, the development of a photonic technology for monitoring perinatal asphyxia is presented and validated in vivo in a preclinical stage. Contrary to state of the art, the technology provides continuous data in real‐time in a non‐invasive manner. Moreover, the technology does not rely on a single parameter as pH or lactate, instead monitors changes of the entirety of physiological parameters accessible by Raman spectroscopy. By a fiber‐coupled Raman probe that is in controlled contact with the skin of the subject, near‐infrared Raman spectra are measured and analyzed by machine learning algorithms to develop classification models. As a performance benchmarking, various hybrid and non‐hybrid classifiers are tested. In an asphyxia model in newborn pigs, more than 1000 Raman spectra are acquired at three different clinical phases—basal condition, hypoxia–ischemia, and post‐hypoxia–ischemia stage. In this preclinical proof‐of‐concept study, figures of merit reach 90% levels for classifying the clinical phases and demonstrate the power of the technology as an innovative medical tool for diagnosing a perinatal adverse outcome.
The lymphatic system plays critical roles in fluid homeostasis, immune regulation, and lipid transport, making its dysfunction a contributor to numerous pathological conditions. Lymphatic tissue engineering aims to develop therapeutic strategies for lymphatic regeneration and repair, depending on the availability of suitable cell sources for lymphatic endothelial cell (LEC) generation. Key cell sources explored for lymphatic tissue engineering include the dermis, bone marrow and stromal vascular fraction. To our knowledge, no existing differentiation protocols can accurately generate lymphatic endothelial progenitor cells (LEPCs). This study presents a novel in vitro differentiation protocol for generating LEPCs from stromal vascular fraction, dermis and bone marrow-derived mesenchymal stem cells (MSCs). The feasibility of using them as tissue sources was first evaluated leading to dermal cells exclusion due to low yield post-isolation, and highlighting the limited differentiation efficiency of bone marrow MSCs. However, the stromal vascular fraction emerged as the optimal source, exhibiting robust LEPCs differentiation and superior scalability. In vitro characterization confirmed that LEPCs maintain a lymphatic endothelial phenotype, exhibiting high migratory ability, robust angiogenic structure formation, and consistent expression of key lymphatic markers in both 2D and 3D cultures, as validated by RNA-Seq analysis. The protocol provides a consistent platform for studying lymphatic endothelial biology and potential applications in regenerative medicine and therapeutic angiogenesis.
Background: Secondary lymphedema is a chronic complication of oncologic surgery and radiotherapy for which effective disease-modifying therapies remain lacking. While mesenchymal stem cells (MSCs) have shown partial benefit in experimental models, direct functional comparison with lineage-committed lymphatic endothelial progenitor cells (LEPCs) remains limited. Methods: Secondary lymphedema was induced in C57BL/6J mice by circumferential tail skin excision with disruption of superficial lymphatics. Animals received intradermal phosphate-buffered saline (PBS), MSCs, or adipose-derived LEPCs on postoperative days 1 and 7. Lymphatic function was longitudinally quantified using IVIS-based near-infrared indocyanine green (ICG) imaging with standardized region-of-interest analysis. Tail diameter was measured serially throughout follow-up as a complementary morphometric parameter. Tissue remodeling was assessed by Picrosirius Red staining and qualitative LYVE-1 immunofluorescence. Statistical analysis incorporated mixed-effects modeling to evaluate treatment group, sex, time, and their interaction terms, with estimation of effect sizes and 95% confidence intervals. Results: LEPC-treated mice demonstrated higher IVIS signal intensity than MSC- and PBS-treated animals, consistent with improved lymphatic transport at the injury site. Longitudinal tail diameter analysis showed a more favorable temporal profile in the LEPC group relative to controls, with exploratory analysis suggesting potential variations in temporal profiles between sexes that warrant further investigation in larger cohorts. Histologic analysis showed reduced non-tissue/void area and a more favorable qualitative pattern of LYVE-1 staining in LEPC-treated tissue. Conclusions: LEPC administration enhanced functional and structural recovery in a murine model of secondary lymphedema. These findings support further translational evaluation of LEPC-based approaches as a regenerative strategy for secondary lymphedema.