Which survivоrship curve shоws lаte-life mоrtаlity?
1. Meаsles A. (.5 pts) Briefly, describe the prоcess оf B cell аctivаtiоn. Include the key stimulus and any assisting cellular players. B. (.5 pts) Briefly, describe the activation of cytotoxic T-cell activation. Include the key stimulus and any assisting cellular players C. (1 pts) The measles virus primarily infects immune cells and causes "immune amnesia" where memory B and T cells are killed. Describe why the measles virus might lead to a reduction in antibody diversity and what the impact would be on individuals infected with measles. D. (3 pts) Signaling lymphocyte activation molecule (SLAM, also called CD150 because it is designated on the CD150 gene) is an integral membrane protein that is expressed on immune cells and acts as the principle cellular receptor for the measles virus. Describe the steps (think central dogma & include machinery, parts of the cells, and molecules involved) in the cell producing SLAM receptors and presenting it in the outer cell membrane (diagrams encouraged). E. (1 pts) What assay(s) could you use to quantify the number of CD150 positive cells are in cultured blood samples before and after being infected with measles and briefly describe how it works?
Peri-implаntitis is аn inflаmmatоry cоnditiоn associated with dental plaque that affects the tissues surrounding dental implants and is characterized by the gradual destruction of the bone and soft tissues that support the implant. The following questions are related to a study by Chandrashekar et al. ( https://doi.org/10.1038/s41598-024-66353-x) that evaluated the effects of dental cements in a per-implant rat model. A. (.75 pts) One important function of dental cement is to fix dental implants to teeth, which contain a very specialized extracellular matrix. First, briefly describe the what the ECM is, what it’s composed of, and at least one important function of the ECM you think is important for teeth. B. (1 pts) In order to study peri-implantitis, this group first performed a scratch assay where they scratched fibroblasts cultured on a bio-ceramic cement (BC) or zinc phosphate (ZP) cement and then looked at the number of cells within the scratched surface after 48 hours in 2.5% or 10% FBS (fetal bovine serum – an additive for cell culture media that contains necessary growth factors). After 24 hours, the cells were fixed and stained for histology. All 10% FBS groups were completely covered at 48 hours, so comparisons were drawn with 2.5% FBS to better detect differences in surfaces. Briefly summarize the findings of this scratch assay, then give a recommendation of BC or ZP cements for further analysis based on the results and describe why. This study then evaluated the biological impact of dental cements in a rat jaw model. Rats were distributed into 4 groups with either a soft diet (SD) (top row) or hard diet(HD) (bottom row): negative control (NC) where titanium implants were inserted but didn’t undergo any further surgery; Titanium implants were inserted and then allowed to heal for 14 days before a re-entry surgery (to simulate clinical cementation) where a sham surgery was performed (to access the site using the same surgical technique but no cement was inserted), the bio-ceramic Cement (BC) was applied, or a positive control (PC) where silk ligature was placed to simulate a form of peri-implantitis. At 14 days post cement/sham/ligature application, the jawbones were harvested for histological evaluation. The images after H&E staining are shown and quantified in the figure below where * indicates significant differences between groups (p