A similar effect of high dose folic acid on pulmonary endothelial function would be expected from the same mechanism and would lead to improvement in pulmonary perfusion. We therefore hypothesise that folic acid, 5 mg or greater, is a useful therapeutic option for pulmonary hypertension and/or refractory severe hypoxaemia, in patients with severe COVID-19 associated pneumonia in whom NO therapy is considered, with a very low risk of adverse effects.Persistent symptoms following a mild traumatic brain injury (mTBI) can have profound implications on all aspects of an individual's functioning. Psychological factors have a significant role in contributing to the development of persistent post-concussion symptoms and predicting outcomes. Biopsychosocial explanations have therefore been applied to prognostic models of mTBI. What is not evident in the literature to date is an understanding of the psychological mechanisms that may be important in mediating the various psychological factors in these models. The construct of psychological flexibility holds promise in this regard. Psychological flexibility is the ability to act in alignment with values in the presence of inner discomfort such as pain and distress. It is hypothesised that psychological flexibility has a significant role in the development and maintenance of persistent symptoms following mild traumatic brain injury. The rationale that forms the basis of this hypothesis is as follows a relationship exists between psychological flexibility and pre-injury psychological risk factors; psychological flexibility is vulnerable to the pathophysiology associated with mTBI; post-injury psychological and neuropsychological factors exacerbate and maintain psychological inflexibility; and psychological flexibility underlies psychological responses to mTBI that contribute to unfavourable outcomes. A discussion of the literature that pertains to each of these points is presented. Based on this hypothesis, we conclude, that there is rationale to empirically explore the role of psychological flexibility in mTBI and its relationship to outcomes. This may also lead to evaluation of specific interventions that target this psychological mechanism in mTBI, such as Acceptance and Commitment Therapy, and improve outcomes for this population.Chondroma is a benign hyaline cartilage tumor and is a relatively common skeletal neoplasm. Uneven distribution of this tumor among the various bones and regions of the skeleton is known but no explanation of this phenomenon followed. The current research aimed to document the exact chondroma distribution in the body. We hypothesized that the cases of all subtypes of chondroma have to be investigated in complex and that obtaining combined data from a large cohort of cases may explain the logic of chondroma distribution and may answer the question of why the hand is the main target of the tumor. We retrospectively analyzed 1529 cases of various subtypes of chondroma. Enchondroma was the most frequent type (65.4%) and the hand was the main target location (49.8% of all cases). The right side of the body was affected in 900 cases (58.9%) and in 629 cases (41.1%) the left side was affected (p = 0.03). The general results for tumor distribution are as follows head and extremities - 92.8%; head, hands, and feet - 71.8%; and hands and feet - 62.8%. In the hand and the feet, multiple chondromas were distributed along the same digital ray in all cases. The anatomical distribution of various subtypes of chondroma follows "the periphery of the being", the uneven lateral distribution, and the "same digital ray" patterns that permits to suggest that genetic mutations affecting the development of the body during the embryonic period are the main etiological component for this tumor.In order to preserve paravertebral muscles and posterior ligaments complex (PLC), this paper proposes a new lumbar laminoplasty surgery for lumbar spinal stenosis (LSS). According to the anatomy of back muscles insertions, building block osteotomy (BBO) which aimed to achieve precise osteotomy and reconstruction based on modular design theory was firstly put forward, and supposed to be achieved by an ultrasound bone scalpel (UBS). In details, lumbar spinous processes are longitudinally split, then supraspinous and interspinous ligaments are sharply cut off longitudinally. After converting to lumbar flexion, lamina osteotomy is innovatively finished by an UBS through interspinous space. After decompression, hollow screws are firstly suggested to be used on each side to fix lamina and spinous processes, and PLC is reconstructed by interrupted suture. Feasibility of this method is evaluated in details. Challenges, advantages and disadvantages are also discussed.Fenofibrate, which is a PPAR-alfpha agonist, increases the level of sulfatide. In this letter we hypothesize on the background of various findings that this is beneficial against COVID-19. Fenofibrate has been used for decades against hypercholesterolemia and has no serious side effects. Therefore, a trial giving fenofibrate to patients with corona virus infection is recommended.A characteristic feature of COVID-19 disease is lymphopenia. Lymphopenia occurs early in the clinical course and is a predictor of disease severity and outcomes. The mechanism of lymphopenia in COVID-19 is uncertain.  https://www.selleckchem.com/products/cdk2-inhibitor-73.html  It has been variously attributed to the release of inflammatory cytokines including IL-6 and TNF-α; direct infection of the lymphocytes by the virus; and rapid sequestration of lymphocytes in the tissues. Additionally, we postulate that prostaglandin D2 (PGD2) is a key meditator of lymphopenia in COVID-19. First, SARS-CoV infection is known to stimulate the production of PGD2 in the airways, which inhibits the host dendritic cell response via the DP1 receptor signaling. Second, PGD2 is known to upregulate monocytic myeloid-derived suppressor cells (MDSC) via the DP2 receptor signaling in group 2 innate lymphoid cells (ILC2). We propose targeting PGD2/DP2 signaling using a receptor antagonist such as ramatroban as an immunotherapy for immune dysfunction and lymphopenia in COVID-19 disease.