VC-resist glioblastoma cell state: vessel co-option as a key driver of chemoradiation resistance.

Glioblastoma (GBM) is a highly lethal type of cancer. GBM recurrence following chemoradiation is typically attributed to the regrowth of invasive and resistant cells. Therefore, there is a pressing need to gain a deeper understanding of the mechanisms underlying GBM resistance to chemoradiation and its ability to infiltrate. Using a combination of transcriptomic, proteomic, and phosphoproteomic analyses, longitudinal imaging, organotypic cultures, functional assays, animal studies, and clinical data analyses, we demonstrate that chemoradiation and brain vasculature induce cell transition to a functional state named VC-Resist (vessel co-opting and resistant cell state). This cell state is midway along the transcriptomic axis between proneural and mesenchymal GBM cells and is closer to the AC/MES1-like state. VC-Resist GBM cells are highly vessel co-opting, allowing significant infiltration into the surrounding brain tissue and homing to the perivascular niche, which in turn induces even more VC-Resist transition. The molecular and functional characteristics of this FGFR1-YAP1-dependent GBM cell state, including resistance to DNA damage, enrichment in the G2M phase, and induction of senescence/stemness pathways, contribute to its enhanced resistance to chemoradiation. These findings demonstrate how vessel co-option, perivascular niche, and GBM cell plasticity jointly drive resistance to therapy during GBM recurrence.

Peritumoral brain zone in glioblastoma: biological, clinical and mechanical features.

Glioblastoma is a highly aggressive and invasive tumor that affects the central nervous system (CNS). With a five-year survival rate of only 6.9% and a median survival time of eight months, it has the lowest survival rate among CNS tumors. Its treatment consists of surgical resection, subsequent fractionated radiotherapy and concomitant and adjuvant chemotherapy with temozolomide. Despite the implementation of clinical interventions, recurrence is a common occurrence, with over 80% of cases arising at the edge of the resection cavity a few months after treatment. The high recurrence rate and location of glioblastoma indicate the need for a better understanding of the peritumor brain zone (PBZ). In this review, we first describe the main radiological, cellular, molecular and biomechanical tissue features of PBZ; and subsequently, we discuss its current clinical management, potential local therapeutic approaches and future prospects.

Microsurgical robotic system enables the performance of microvascular anastomoses: a randomized in vivo preclinical trial.

Technical advances in microsurgery have enabled complex oncological reconstructions by performing free tissue transfers, nerve and lymphatic reconstructions. However, the manual abilities required to perform microsurgery can be affected by human fatigue and physiological tremor resulting in tissue damage and compromised outcomes. Robotic assistance has the potential to overcome issues of manual microsurgery by improving clinical value and anastomoses' outcomes. The Symani Surgical System, a robotic platform designed for microsurgery, was used in this in-vivo preclinical study using a rat animal model. The tests included anastomoses on veins and arteries performed by microsurgeons manually and robotically, with the latter approach using Symani. The anastomoses were assessed for patency, histopathology, and execution time. Patency results confirmed that the robotic and manual techniques for venous and arterial anastomoses were equivalent after anastomosis, however, the time to perform the anastomosis was longer with the use of the robot (p < 0.0001). Histological analysis showed less total average host reaction score at the anastomotic site in robotic anastomosis for both veins and arteries. This study demonstrates the equivalence of vessel patency after microsurgical anastomoses with the robotic system and with manual technique. Furthermore, robotic anastomosis has proven to be slightly superior to manual anastomosis in terms of decreased tissue damage, as shown by histological analysis.

Drowning Accidents in a Spanish Pediatric Intensive Care Unit: An Observational Study for 29 Years.

INTRODUCTION: Drowning is one of the most frequent accidents in children. We aimed to describe demographic and epidemiological characteristics of drowned children who required admission to a pediatric intensive care unit (PICU) to identify risk factors to guide possible preventive measures to avoid severe drowning. METHODS: We conducted an observational study for 29 years (retrospective between 1991 and 2004; prospective between 2005 and 2019) that included all children (0-15 years old) requiring PICU admission after drowning. Data regarding patient characteristics, accident circumstances, and neurological outcomes at PICU discharge were analyzed. RESULTS: A total of 160 patients were included, with no significant decrease over the study period. There was a predominance of males (75%), young age (60%; 1-5 years), summer months (91.1%; May-September), tourists (14.12 [95% confidence interval, 9.2-21.7] times higher risk of drowning than residents), swimming pool accidents (88.8%), and inadequate supervision (77.9%). The mortality was 18.7%, and 7.5% of admitted children had severe neurological sequelae. The initial resuscitation maneuvers by accident witnesses were incorrect in nearly half of the patients in whom these could be analyzed. CONCLUSIONS: Emphasis should be placed on implementing preventive measures, focused on the described risk groups, and insisting on adequate supervision, swimming training programs, and training of the general population in safe rescue and cardiopulmonary resuscitation.

New Robotic System with Wristed Microinstruments Allows Precise Reconstructive Microsurgery: Preclinical Study.

BACKGROUND: Microsurgery allows complex reconstruction of tissue defects after oncological resections or severe trauma. Performing these procedures may be limited by human tremor, precision, and manual dexterity. A new robot designed specifically for microsurgery with wristed microinstruments and motion scaling may reduce human tremor and thus enhance precision. This randomized controlled preclinical trial investigated whether this new robotic system can successfully perform microsurgical needle driving, suturing, and anastomosis. METHODS: Expert microsurgeons and novices completed six needle passage exercises and performed six anastomoses by hand and six with the new robot. Experienced microsurgeons blindly assessed the quality of the procedures. Precision in microneedle driving and stitch placement was assessed by calculating suturing distances and angulation. Performance of microsurgical anastomoses was assessed by time, learning curves, and the Anastomosis Lapse Index score for objective performance assessment. RESULTS: Refined precision in suturing was achieved with the robot when compared with the manual technique regarding suture distances (p = 0.02) and angulation (p < 0.01). The time required to perform microsurgical anastomoses was longer with the robot, however, both expert and novice microsurgeons reduced times with practice. The objective evaluation of the anastomoses performed by novices showed better results with the robot. CONCLUSIONS: This study demonstrated the feasibility of performing precise microsutures and anastomoses using a new robotic system. Compared to standard manual techniques, robotic procedures were longer in time, but showed greater precision.

Importance of specialized paediatric and neonatal transport. Current situation in Spain: Towards a more equitable and universal future.

Specialized paediatric and neonatal transport is a useful and essential resource in the interhospital transfer of these patients. It allows bringing the material and personal resources of an intensive care unit closer to the regional hospitals where the patient can be found. The benefits of these teams are very well demonstrated in the literature. These units should be part of the emergency systems, while it would be recommended that they be staff integrated in the tertiary hospitals, in order to maintain the necessary skills and competencies. The team, made up of physicians, nurses and emergency medical technicians, must master both the pathophysiology of transport and that of the critical patient in this age range. A high quality of both human and care is important, so continuous training and periodic recycling will be essential to be compliant with the quality indicators in transport. Likewise, it is essential to have specific vehicles adapted to this function, which allow carrying the wide variety of necessary material, as well as the electromedicine that is required. However, in Spain this paediatric and neonatal transport model is not standardized and therefore is not homogeneous: there are different models that do not always provide adequate quality, making it necessary to implement specialized units throughout the country to guarantee sanitary transport quality to any critical child or neonate.

[Importance of specialized paediatric and neonatal transport. Current situation in Spain: Towards a more equitable and universal future]. / Importancia del transporte pediátrico y neonatal especializado. Situación actual en España: Hacia un futuro más equitativo y universal.

Specialized paediatric and neonatal transport is a useful and essential resource in the interhospital transfer of these patients. It allows bringing the material and personal resources of an intensive care unit closer to the regional hospitals where the patient can be found. The benefits of these teams are very well demonstrated in the literature. These units should be part of the emergency systems, while it would be recommended that they would be staff integrated in the tertiary hospitals, in order to maintain the necessary skills and competencies. The team, made up of physicians, nurses and emergency medical technicians, must master both the pathophysiology of transport and that of the critical patient in this age range. A high-quality of both human and care is important, so continuous training and periodic recycling will be essential to be compliant with the quality indicators in transport. Likewise, it is essential to have specific vehicles adapted to this function, which allow carrying the wide variety of necessary material, as well as the electromedicine that is required. However, in Spain this paediatric and neonatal transport model is not standardized and, therefore, is not homogeneous: there are different models that do not always provide adequate quality, making it necessary to implement specialized units throughout the country to guarantee sanitary transport quality to any critical child or neonate.

Effects of Ischemic Preconditioning and C1 Esterase Inhibitor Administration following Ischemia-Reperfusion Injury in a Rat Skin Flap Model.

BACKGROUND: Ischemia-reperfusion (I/R) injury is a serious condition that can affect the success rate of microsurgical reconstructions of ischemic amputated limbs and complex tissue defects requiring free tissue transfers. The purpose of this study was to evaluate the effects of ischemic preconditioning (IPC) and C1 esterase inhibitor (C1-Inh) intravenous administration following I/R injury in a rat skin flap model. METHODS: Superficial caudal epigastric skin flaps (3 cm × 7 cm) were performed on 50 Wistar rats that were randomly divided into five groups. Ischemia was not induced in the control group. All other flaps underwent 8 hours of ischemia prior to revascularization: I/R control group (8-hour ischemia), IPC group (preconditioning protocol + 8-hour ischemia), C1-Inh group (8-hour ischemia + C1-Inh), and IPC + C1-Inh group (preconditioning protocol + 8-hour ischemia + C1-Inh). Survival areas were macroscopically assessed after 1 week of surgery, and histopathological and biochemical evaluations were also measured. RESULTS: There were no significant differences in flap survival between the treatment groups that were suffering 8 hours of ischemia and the control group. A significant increase in neovascularization and lower edema formation were observed in the IPC group compared with that in the I/R group. Biochemical parameters did not show any significant differences. CONCLUSION: Intravenous administration of C1-Inh did not significantly modulate I/R-related damage in this experimental model, but further research is needed. On the other hand, IPC reduces tissue damage and improves neovascularization, confirming its potential protective effects in skin flaps following I/R injury.

Prognostic Factors of Children Admitted to a Pediatric Intensive Care Unit After an Episode of Drowning.

OBJECTIVE: The aim of this study was to evaluate the prognostic factors of patients admitted to a pediatric intensive care unit (PICU) after drowning. METHODS: Retrospective observational study from January 1992 to December 2004 and prospective study from January 2005 to December 2015 were conducted in a tertiary children's hospital PICU. The data analyzed refer to the patient, event, type of resuscitation performed, and clinical situation after resuscitation and at arrival to the PICU; results of additional tests; and clinical evolution and neurological status at discharge from the PICU (categorized as death, severe encephalopathy, or normal). The considered potential prognostic factors were whether drowning was witnessed, the type of initial resuscitation, Glasgow Coma Scale score at admission, pupil status and reactivity, and pH. RESULTS: One hundred thirty-one patients were registered. Mortality was 16.7%, and 8.3% had significant neurological sequelae. The clearest factor associated with poor outcome was the type of initial resuscitation performed. All patients who did not require cardiopulmonary resuscitation (CPR), or only basic CPR, had good outcomes; 96.3% of those who required advanced CPR with epinephrine administration had poor outcomes. Patients who needed advanced resuscitation with administration of epinephrine had lower temperature, Glasgow Coma Scale score, pH, and bicarbonate at admission and higher level of glucose. In this group, there was also a higher incidence of seizures, acute respiratory distress syndrome, hemodynamic compromise, and acute renal failure. CONCLUSIONS: The need for advanced CPR with epinephrine administration on the scene predicts poor neurological outcome (severe encephalopathy or death) in drowned children.

Autophagy modulation in animal models of corneal diseases: a systematic review.

Autophagy is an intracellular catabolic process implicated in the recycling and degradation of intracellular components. Few studies have defined its role in corneal pathologies. Animal models are essential for understanding autophagy regulation and identifying new treatments to modulate its effects. A systematic review (SR) was conducted of studies employing animal models for investigations of autophagy in corneal diseases. Studies were identified using a structured search strategy (TS = autophagy AND cornea*) in Web of Science, Scopus, and PubMed from inception to September 2019. In this study, 230 articles were collected, of which 28 were analyzed. Mouse models were used in 82% of the studies, while rat, rabbit, and newt models were used in the other 18%. The most studied corneal layer was the epithelium, followed by the endothelium and stroma. In 13 articles, genetically modified animal models were used to study Fuch endothelial corneal dystrophy (FECD), granular corneal dystrophy type 2 (GCD2), dry eye disease (DED), and corneal infection. In other 13 articles, animal models were experimentally induced to mimic DED, keratitis, inflammation, and surgical scenarios. Furthermore, in 50% of studies, modulators that activated or inhibited autophagy were also investigated. Protective effects of autophagy activators were demonstrated, including rapamycin for DED and keratitis, lithium for FECD, LYN-1604 for DED, cysteamine and miR-34c antagomir for damaged corneal epithelium. Three autophagy suppressors were also found to have therapeutic effects, such as aminoimidazole-4-carboxamide-riboside (AICAR) for corneal allogeneic transplantation, celecoxib and chloroquine for DED.

International microsurgery simulation society (IMSS) consensus statement on the minimum standards for a basic microsurgery course, requirements for a microsurgical anastomosis global rating scale and minimum thresholds for training.

INTRODUCTION: Microsurgery is a surgical technique that uses optical magnification as well as specific instruments to address necessary reconstructive procedures in different medical specialties. The apprenticeship of this technique requires overcoming a steep learning curve. There is a need for standardization of the training criteria in microsurgery. The International Microsurgery Simulation Society (IMSS) was born in 2011, since then its main objective has been to connect the main international specialists and educators of this sub-specialty to share and discuss the ethical and scientific basis of preclinical microsurgery teaching. METHODS: In order to achieve a consensus on the minimum standards for the organization of basic microsurgery training courses, the requirements for a microsurgical anastomosis global rating scale and minimum thresholds for training, a total of nineteen independent global experts participated in a formal consultative consensus development program. The agreement criteria for each statement was established when consensus of 65-100% was reached. RESULTS: There have been established six recommendations concerning minimum standards for a basic microsurgery course, one recommendation in relation to minimum thresholds for training and four recommendations regarding the global rating scale as gold standard for a microsurgical anastomosis assessment. The eleven defined recommendations reached the agreement threshold of 65-100%. CONCLUSIONS: The development of this consensus sets the minimum recommended requirements for conducting basic microsurgery training courses, as well as suggestions for objective assessment of the learning curve and skills of trainees.

Animal models used to study direct peripheral nerve repair: a systematic review.

OBJECTIVE: Peripheral nerve repair is required after traumatic injury. This common condition represents a major public health problem worldwide. Recovery after nerve repair depends on several factors, including the severity of the injury, the nerve involved, and the surgeon's technical skills. Despite the precise microsurgical repair of nerve lesions, adequate functional recovery is not always achieved and, therefore, the regeneration process and surgical techniques are still being studied. Pre-clinical animal models are essential for this research and, for this reason, the focus of the present systematic review (according to the PRISMA statement) was to analyze the different animal models used in pre-clinical peripheral nerve repair studies. DATA SOURCES: Original articles, published in English from 2000 to 2018, were collected using the Web of Science, Scopus, and PubMed databases. DATA SELECTION: Only preclinical trials on direct nerve repair were included in this review. The articles were evaluated by the first two authors, in accordance with predefined data fields. OUTCOME MEASURES: The primary outcomes included functional motor abilities, daily activity and regeneration rate. Secondary outcomes included coaptation technique and animal model. RESULTS: This review yielded 267 articles, of which, after completion of the screening, 49 studies were analyzed. There were 1425 animals in those 49 studies, being rats, mice, guinea pigs, rabbits, cats and dogs the different pre-clinical models. The nerves used were classified into three groups: head and neck (11), forelimb (8) and hindlimb (30). The techniques used to perform the coaptation were: microsuture (46), glue (12), laser (8) and mechanical (2). The follow-up examinations were histology (43), electrophysiological analysis (24) and behavioral observation (22). CONCLUSION: The most widely used animal model in the study of peripheral nerve repair is the rat. Other animal models are also used but the cost-benefit of the rat model provides several strengths over the others. Suture techniques are currently the first option for nerve repair, but the use of glues, lasers and bioengineering materials is increasing. Hence, further research in this field is required to improve clinical practice.

A Pre-clinical Rat Model for the Study of Ischemia-reperfusion Injury in Reconstructive Microsurgery.

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many areas of biomedical research due to its cost-effectiveness and its translation to humans. This protocol describes a method to create a preclinical free skin flap model in rats with ischemia-reperfusion injury. The described 3 cm x 6 cm rat free skin flap model is easily obtained after the placement of several vascular ligatures and the section of the vascular pedicle. Then, 8 h after the ischemic insult and completion of the microsurgical anastomosis, the free skin flap develops the tissue damage. These ischemia-reperfusion injury-related damages can be studied in this model, making it a suitable model for evaluating therapeutic agents to address this pathophysiological process. Furthermore, two main monitoring techniques are described in the protocol for the assessment of this animal model: transit-time ultrasound technology and laser speckle contrast analysis.

Ischemia-reperfusion injury in a rat microvascular skin free flap model: A histological, genetic, and blood flow study.

Ischemia reperfusion injury is associated with tissue damage and inflammation, and is one of the main factors causing flap failure in reconstructive microsurgery. Although ischemia-reperfusion (I/R) injury is a well-studied aspect of flap survival, its biological mechanisms remain to be elucidated. To better understand the biological processes of ischemia reperfusion injury, and to develop further therapeutic strategies, the main objective of this study was to identify the gene expression pattern and histological changes in an I/R injury animal model. Fourteen rats (n = 7/group) were randomly divided into control or ischemia-reperfusion group (8 hours of ischemia). Microsurgical anastomoses were objectively assessed using transit-time-ultrasound technology. Seven days after surgery, flap survival was evaluated and tissue samples were harvested for anatomopathological and gene-expression analyses.The I/R injury reduced the survival of free flaps and histological analyses revealed a subcutaneous edema together with an inflammatory infiltrate. Interestingly, the Arginase 1 expression level as well as the ratio of Arginase 1/Nitric oxide synthase 2 showed a significant increase in the I/R group. In summary, here we describe a well-characterized I/R animal model that may serve to evaluate therapeutic agents under reproducible and controlled conditions. Moreover, this model could be especially useful for the evaluation of arginase inhibitors and different compounds of potential interest in reconstructive microsurgery.

Reestablishment of Lymphatic Drainage after Vascularized Lymph Node Transfer in a Rat Model.

BACKGROUND: Vascularized lymph node transfer has recently received attention as a potential surgical treatment for lymphedema. Despite good results in some series, the mechanism and benefits of vascularized lymph node transfer have yet to be fully understood. This study aimed to investigate the reestablishment of drainage into transferred lymph nodes following vascularized lymph node transfer in a rat model. METHODS: Seven rats underwent vascularized lymph node transfer. The operation performed on each rat consisted of two parts. First, the left groin lymph node basin with superficial epigastric vessels was harvested as a free flap. Second, the flap was reattached in the left groin of the rat by means of end-to-end microvascular anastomoses. Anastomosis patency was assessed immediately postoperatively and at the time of animal sacrifice. The rats were evaluated for reestablishment of lymphatic flow into the transplanted nodes at 1-month intervals for at least 6 months postoperatively. This was accomplished noninvasively by injecting the rats in their flanks with fluorescent indocyanine green, which was detected using a Photodynamic Eye infrared camera. RESULTS: Anastomoses were patent in all seven rats immediately postoperatively. No indocyanine green uptake was seen in the transplanted lymph node basins in the first 2 months postoperatively in any of the rats. In five of seven rats, however, indocyanine green uptake was demonstrated in the transplanted lymph node basin by 6 months (average, 13 weeks). CONCLUSION: The authors report uptake of indocyanine green in five of seven rats at an average of 13 weeks after lymph node transplantation, consistent with the reestablishment of lymphatic drainage into the transplanted nodes.

Adipose-Derived Stem Cells Ameliorate Ischemia-Reperfusion Injury in a Rat Skin Free Flap Model.

BACKGROUND: Ischemia-reperfusion (I/R) injury is inevitable during free tissue transfers. When the period of ischemia exceeds the tissue tolerance, it causes necrosis and flap failure. The aim of this study was to investigate the effects of adipose-derived stem cells (ASCs) embedded in a collagen type I scaffold on the survival of free skin flaps to counteract I/R injury. METHODS: Left superficial caudal epigastric skin flaps (3 × 6 cm) were performed in 28 Wistar rats that were divided into four groups. The flaps elevated in the animals of the control group did not suffer any ischemic insult, and the vascular pedicle was not cut. All other flaps were subjected to 8 hours of ischemia prior to revascularization: I/R control group (8 hours of ischemia), I/R scaffold group (8 hours of ischemia + collagen type I scaffold), and I/R scaffold-ASCs group (8 hours of ischemia + collagen type I scaffold with rat ASCs embedded). Transit-time ultrasound blood flow measurements were performed. After 7 days, the areas of flap survival were measured and tissues were stained with hematoxylin/eosin and Masson's trichrome stain for histological analysis. RESULTS: The mean percentage flap survival area was significantly higher in the ASCs-treated flaps (I/R scaffold-ASCs group) compared with the ischemic controls (I/R control group and I/R scaffold group). Higher vascular proliferation and lower severity of necrosis and inflammatory changes were seen histologically in the samples of the ASCs-treated group. No significant difference in blood flow was detected between groups. CONCLUSION: Subcutaneous administration of ASCs embedded on a collagen type I scaffold reduces tissue damage after I/R injury in microvascular free flaps.