instruction:
Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
question:
Context: Among factors that may affect the potency of botulinum toxin A (Botox), it is said that foam, together with bubbles, may cause surface denaturation of the toxin.', 'To determine whether the muscle relaxation effect of Botox is preserved and has the same duration when it is reconstituted in the presence of foam.', 'Six female volunteers, aged 42 to 56 years old, were treated for glabellar and periocular wrinkles. Each half of the face was treated with 16 U of Botox divided in four sites: three at the lateral orbital area and one at the medial brow, in the glabellar region. The right side received Botox gently reconstituted with saline to avoid foaming formation. The left side of the face was treated with Botox that was rapidly reconstituted in order to achieve as many bubbles as possible, even with shaking. Blinded observers compared pretreatment and posttreatment photographs and answered assessment-related questions. The results were analyzed clinically and statistically.', 'There was no difference in muscle paralysis between treated sides in all patients, neither in early (15 days) nor late (4 months) follow-up evaluations.
Answer: Botox maintains its potency even in the presence of foaming during the reconstitution process.
answer:
Does foam during reconstitution affect the potency of botulinum toxin type A?

question:
Context: A cross-sectional study.', 'This study aims to investigate the correlation of the cervical canal and spinal cord size, and evaluate whether the size of the spinal cord relative to the spinal canal is a risk factor for development of cervical spinal cord compression (SCC).', 'There is little knowledge regarding the relationship between cervical bony canal and spinal cord diameters. Although developmental canal stenosis has been recognized as a risk factor for SCC, the size of the spinal cord relative to the spinal canal has not been similarly discussed.', 'Cervical canal anteroposterior (AP) diameters on X-rays and AP diameters and cross-sectional areas of dural sacs and spinal cords on magnetic resonance imaging (MRI) were measured in 1211 healthy volunteers. Correlation between cervical canal diameter on X-rays and AP diameter and cross-sectional area of dural sacs and spinal cords on MRI were assessed. The ratio of the AP diameter of the spinal cord/dural sac was compared between subjects with and without SCC.', 'Spinal canal diameters were not highly correlated with spinal cord AP diameters and cross-sectional areas, although spinal canal diameters were significantly correlated with dural sac AP diameters. The individual difference in the ratio of the AP diameter of the spinal cord/dural sac was large (35%-93%), and the ratio was significantly larger in the subjects with SCC. An AP diameter ratio more than 62% at the C2 to C3 disc level is a risk factor for developing SCC.
Answer: The spinal cord diameter was independent of the spinal canal diameter and the relative size of a spinal cord and spinal canal differed on an individual basis. In addition, the ratio of spinal cord/dural sac in subjects with SCC was significantly larger. Therefore, a relatively large spinal cord could be a risk factor for SCC.
answer:
Is relatively Large Cervical Spinal Cord for Spinal Canal a Risk factor for Development of Cervical Spinal Cord Compression : A Cross-Sectional Study of 1211 Subjects?

question:
Context: Vessel formation is a crucial event in tissue repair after injury. Thus, one assumption of innovative therapeutic approaches is the understanding of its molecular mechanisms. Notwithstanding our knowledge of the role of Protein Kinase C epsilon (PKC) in cardio-protection and vascular restenosis, its role in vessel progenitor differentiation remains elusive.', 'Given the availability of PKC pharmacological modulators already tested in clinical trials, the specific aim of this study is to unravel the role of PKC in vessel progenitor differentiation, with implications in vascular pathology and vasculogenesis.', 'Mouse Peri-Vascular Adipose Tissue (PVAT) was used as source of mesenchymal vessel progenitors. VEGF-induced differentiation of PVAT cells down-regulates both PKC and p-PAK1 protein expression levels. PKC overexpression and activation: i) reduced the expression levels of SMA and PECAM in endothelial differentiation of PVAT cells; ii) completely abrogated tubules formation in collagen gel assays; iii) increased the expression of p-PAK1.
Answer: PKC negatively interferes with vessel progenitor differentiation via interaction with PAK-1.
answer:
Is pKC a negative regulator of PVAT-derived vessel formation?