Modelling the effects of cerebral microthrombi on tissue oxygenation and cell death

Thrombectomy, the mechanical removal of a clot, is the most common way to treat ischaemic stroke with large vessel occlusions. However, perfusion cannot always be restored after such an intervention. It has been hypothesised that the absence of reperfusion is due to the clot fragments that block the downstream vessels. In this paper, we present a new way of quantifying the effects of cerebral microthrombi on oxygen transport to tissue in terms of hypoxia and ischaemia. The oxygen transport was simulated with the Green’s function method on physiologically accurate microvascular cubes, which was found independent of both microvascular geometry and length scale. The microthrombi occlusions were then simulated in the microvasculature, which were extravasated over time with a new vessel extravasation model. The tissue hypoxic fraction was fitted as a sigmoidal function of vessel blockage fraction, which was then taken to be a function of time after the formation of microthrombi occlusions. A novel hypoxia-based 3-state cell death model was finally proposed to simulate the hypoxic tissue damage over time. Using the cell death model, the impact of a certain degree of microthrombi occlusions on tissue viability and microinfarct volume can be predicted over time. Quantifying the impact of microthrombi on oxygen transport and tissue death will play an important role in full brain models of ischaemic stroke and thrombectomy.

“SU JOK” THERAPY AND SCLEROLOGY PROFILE MONITORING FOR MANAGING CHEST PAIN AT HOME WHILE AVOIDING HOSPITAL ADMISSION DURING THE COVID-19 PANDEMIC: A CASE STUDY

Background: The COVID-19 pandemic has resulted in people avoiding hospital admission for non-COVID patients and forcing people to seek help via telehealth or alternative medicine.Case study: A 30-year-old man from Solo, Indonesia, complained of left chest discomfort with an irregular heartbeat. This man sent an inquiry and his left eye sclera profile through WhatsApp on July 20, 2020 to a researcher, who is a nurse and “Su jok” therapist. Protocol for “Su jok” therapy was sent back through WhatsApp, and after applying the treatment for 30 minutes, the patient felt better, and symptoms were less severe. The full protocol to be applied for the following days was then sent to the patient. After three weeks, there was a less sharp red line in the sclera area of the vessel blockage, and he only experienced mild symptoms.Conclusion: The case study shows that “Su jok” therapy may become an alternative therapy for managing chest pain at home. Sclerology can be a complementary choice to monitor a patient’s heart condition. Visiting the hospital, however, is still necessary when the symptoms become worse.

Post-traumatic massive hand lymphedema fully cured by vascularized lymph node flap transfer

Post-traumatic localized hand lymphedema is a rare situation and its diagnosis may be difficult, causing lack of care leading to failure of care. Our case study is of two young women with massive post-traumatic hand lymphedema who were treated for algodystrophy for 2 years, and whose bandages and physiotherapy were unsuccessful. Major social and psychological consequences due to difficulty with diagnosis and management resulting in inappropriate tests and therapeutic treatment were prescribed due to these issues. Noncontrast magnetic resonance lymphography revealed complete lymphatic vessel blockage in the hand and wrist. A vascularized lymph node flap harvested at the groin level was transferred to the elbow level 1 month after local dermolipectomy. These procedures resulted in the restoration of lymphatic flow. Both patients were definitely cured, and they returned to normal life within 6 months after surgery. Lymph node flap transfer associated with dermolipectomy may cure massive localized lymphedema in selected cases.

Use of a Green Fluorescent Strain for Analysis of Xylella fastidiosa Colonization of Vitis vinifera

ABSTRACT Xylella fastidiosa causes Pierce's disease of grapevine as well as several other major agricultural diseases but is a benign endophyte in most host plants. X. fastidiosa colonizes the xylem vessels of host plants and is transmitted by xylem sap-feeding insect vectors. To understand better the pattern of host colonization and its relationship to disease, we engineered X. fastidiosa to express a green fluorescent protein (Gfp) constitutively and performed confocal laser-scanning microscopic analysis of colonization in a susceptible host, Vitis vinifera. In symptomatic leaves, the fraction of vessels colonized by X. fastidiosa was fivefold higher than in nearby asymptomatic leaves. The fraction of vessels completely blocked by X. fastidiosa colonies increased 40-fold in symptomatic leaves and was the feature of colonization most dramatically linked to symptoms. Therefore, the extent of vessel blockage by bacterial colonization is highly likely to be a crucial variable in symptom expression. Intriguingly, a high proportion (>80%) of colonized vessels were not blocked in infected leaves and instead had small colonies or solitary cells, suggesting that vessel blockage is not a colonization strategy employed by the pathogen but, rather, a by-product of endophytic colonization. We present evidence for X. fastidiosa movement through bordered pits to neighboring vessels and propose that vessel-to-vessel movement is a key colonization strategy whose failure results in vessel plugging and disease.