Medical student's note

CHP5 Nutrition 1. Please give examples of red meat, white meat and lean meat. Red meat: beef, lamb. White meat: chicken, turkey. Lean meat: ostrich, venison. 2. What is lean body weight and how does it differ from routine measurement? Lean body mass includes the weight of all the following elements:   Organs Skin Bones Body Water Muscle Mass Lean body mass is calculated as the difference between total body weight and body fat weight, or more simply, the weight of everything except the fat. The range of lean body mass considered to be healthy is around 70% - 90% with women being towards the lower end of the range and men higher. 3. Why does vitamin B12 deficiency cause glossitis? Parietal cells secrete intrinsic factor which is required for the absorption of vitamin B12. Vitamin B12 deficiency results in megaloblastic anemia and may present as glossitis. The appearance of the tongue in vitamin B12 deficiency is described as "beefy" or "fiery red and sore". 4. Is a do...

CHP4 Infectious diseases, tropical medicine and sexually transmitted infection 1. Which haematogenous infections (bacterial, fungal and protozoal) can give rise to positive findings in the urine? What are the appropriate microbiological investigations for each infection? Haematogenous infections seldom give rise to positive findings in the urine. However, infections such as infective endocarditis do produce red cells in the urine. On the whole, microbiological investigations of the urine are not useful in haematogenous infections. 2. Explain the term ‘zoonosis’. A zoonosis is an infectious disease that has jumped from a non-human animal to humans. Zoonotic pathogens may be bacterial, viral or parasitic, or may involve unconventional agents and can spread to humans through direct contact or through food, water or the environment. 3. What are soil transmitters? Hookworm, Ascaris, and whipworm are known as soil-transmitted helminths (parasitic worms).  4. Explain the difference betwee...

CHP3 Clinical immunology 1. How lymphocytes (especially B) can maintain receptors on their surfaces? Is this genetically related? If so, when the lymphocytes are first exposed to the antigens, how could the antigen receptor be synthesized?  Is there a mutation within the nuclei of these lymphocytes when they learn to make the receptors? If there is, can you explain how this occurs? B cells differentiate from lymphoid cells in the bone marrow in a way that allows them to express an antigen receptor on the surface permanently. The expression of the receptor is a definition of B cells and is a result of the differentiation pathway. The antigen receptor varies from one immature B cell to another. There are billions of different receptors, but any B cell will express only one type of receptor. The antigen does not ‘design’ the receptor; rather, a clonal B cell that recognizes the antigen (very few B cells will recognize a given antigen) will proliferate in response to the antigen and si...

CHP2 Molecular cell biology and genetic disorders 1. As cells grow and regenerate, what mechanism does the body use to get rid of the continuously dying cells? And what kind of cells can’t be replaced once dead? Cells are continually dying by a process of apoptosis (programmed cell death). These cells (or their fragments) are phagocytosed by macrophages or neutrophils where they undergo autolysis within these phagosomes. It is important to noted that brain cells cannot be replaced once dead. 2. Why some of the autosomal dominant diseases have a male or female preponderance? By definition, the genes responsible for autosomal dominant diseases must be located on the 22 autosomes; thus both males and females are affected. Males and females are affected in equal proportions except in sex-limited disorders, e.g. ovarian cancer with BRCA1 locus. Characteristics of  X-linked dominant disorders includes no male-to-male transmission, no skipped generations, females are affected twice as oft...

CHP1: Ethics and communication 1. Regarding medical ethics, if a man is discovered to be hepatitis B or C positive, is it advisable for the physician to inform the wife or sexual contact of the patient? No. The doctor can only give confidential information to the patient. One would expect, however, that the doctor would counsel the patient, giving advice on his sexual behaviour and safe sex. The patient would hopefully discuss the results with his partner. (主动告诉患者，被动告诉患者亲属) 2. Is it unlawful in most countries to limit medical care, particularly by rationing the usage of drugs? Surely rationing must be against the oath we took as doctors to provide the best care available. In all healthcare systems, rationing has become inevitable, partly because of the high costs of modern therapies. To be in line with good medical practice, doctors must acknowledge the obligation that, if rationing is unavoidable, it should be carried out in a responsible and justifiable way. 3. What is meant by QALYs...