Skin PPQ Flashcards
Binding of Hedgehog ligands to the Patched-1 receptor activates Smoothend, which ultimately results of the transcription of genes in embryonic patterning and limb development. What prevents this process from a caring in the absence of a stimulus?
Binding of an inhibitory molecule to Smoothend
Dephosphorylation of Smoothend
Steric hindrance of Smoothend translocation
Lack of transcription of Smoothend
Ubiquitination and proteasomal degradation of Smoothend
Steric hindrance of Smoothend translocation
A woman undergoes photodynamic therapy ( PDT) for skin cancer. Aminolevulinic acid ALA is applied to her skin followed by the radiation with red light. What is the major cytotoxic agents generated by this process?
Hydrogen peroxide Hydroxyl radical Peroxynitrite Singlet oxygen Superoxide anion
Singlet oxygen
The electromagnetic spectrum of radiation is utilised in many Medical Technologies including imaging techniques such as x-rays computed tomography (CT) scans and magnetic resonance imaging (MRI), and treatment methods such photodynamic therapy ( PDT) and psoralen with UVA therapy (PUVA). Which technique uses radiation of the longest wavelength?
CT
PUVA
MRI
PDT
MRI
MRI uses radio waves
CT uses x rays
PUVA uses UV light
PDT uses visible (red) light
A 48 year old woman uses phot dynamic t herapy (PDT) for basal cell carcinoma which involves the application of ALA (5-aminolevulinic acid) to the lesion. What is the purpose of ALA therapy?
To act as a cytotoxic agent
To act as a photosensitising agent
To emit photons
To minimize side effects
To prevent DNA replication
To act as a photosensitising agent
A man is due to undergo radiotherapy for prostate cancer. This treatment depends on the ability radiation to remove an electron from an atom or molecule person generating free radicals. What type of electromagnetic radiation will be the most suitable for this purpose?
Gamma radiation
Infrared radiation
Microwaves
Radio waves
Ultraviolet radiation
Gamma radiation
radiotherapy delivers a high radiation dose causing formation of free radicals
Radiotherapy delivers a high radiation causing formation of free radicals. What aspect of tumours can make them resistant to radiotherapy?
Chromosomal translocation
High cellular protein levels
Hypoxia
Mutations in tumour suppressors
Rapid DNA replication
Hypoxia
The T cell receptor (TCR) of an autoreactive T cell binds to the MHC II molecule on an antigen presenting cell. However co-stimulation via the CD 28 receptor on the T cell does not happen. What now happens to the T cell?
Becomes activated
Goes into a state of anergy (absence of the normal immune response to a particular antigen or allergen)
Goes through negative selection
Undergoes Apoptosis (the death of cells which occurs as a normal and controlled part of an organism’s growth or development).
Undergoes necrosis
Goes into a state of anergy (absence of the normal immune response to a particular antigen or allergen)
Autoimmune diseases such as inflammatory bowel disease and multiple sclerosis are characteristically associated with the recently identified subset of T cells name of Th 17 cells. Which cytokine particularly promotes the proliferation and maintenance of these cells?
IL-2
IL-4
IL-4
IL-17
IL-23
IL-23
Following a lifetime of beach holidays (Saskia!) in exotic locations and 69 year old has developed a non healing ulcer on her face. After biopsy of the lesion her Dr. diagnoses squamous cell carcinoma. Which layer of the epidermis has this cancer arisen in?
Stratum basale
Stratum corneum
Stratum granulosum
Stratum lucidum
Stratum spinosum
Stratum spinosum
You are doing a Ph.D. examining the regulation of cell death in leukocytes and you need to be able to quantify the percentage of apoptopic cells in a population of isolated cells. Apoptosis is a form of cell death in phosphatidyl serine becomes exposed on the outer surface of the dying sale her you’ve heard of these can be exploited to measure apoptosis. Which laboratory technique will be the most appropriate to achieve this?
ELISA
Flow cytometry
Immunohistochemistry
PCR
Western blotting
Flow cytometry
In 2006 scientists conducted a phase one clinical trial of a new biological therapy to treat B cell chronic lymphocytic leukaemia (CLL). The trial involved a monoclonal antibody that binds to CD 28 which is present on the surface of some leukocytes. Which type of cell is being targeted by this therapy?
Mature B cells
Mature T cells
Monocytes
Naïve T cells
Neutrophils
Naïve T cells
Infections are a major cause of morbidity and mortality in patients with cancer with the risk of infection being primarily related to their cytotoxic and immunosuppressive chemotherapy. Which group of patients is at greatest risk of this complication?
Patients with breast cancer
Patients with basal cell carcinoma
Patients with colon cancer
Patients with leukaemia
Patients with lung cancer
Patients with leukaemia
