FS exam 3 Flashcards
(141 cards)
1
Q
what are the sources of toxic components in food? p46
A
Naturally occurring chemicals
Compounds produced by processing
Food additives
Microbial toxins
2
Q
what is the GRAS list? what are some examples?
A
Generally Recognized As Safe. 不用测试也知道是安全的。salt, pepper, baking powder, vitamin E
3
Q
what is the difference between Food additives and Dietary Supplements?
A
FA: 需要 pre-market approval, 如果有没有授权的添加剂会被seized。DS: 不需要 pre-market approval, 包含很多substances not legal to use in foods, harm must be demonstrated before seizing products
4
Q
what is GRAS review?
A
（再检查一次是不是安全的）添加剂被 toxicologists review之后，如果被测为安全的，那就会被认定成GRAS. Not formally tested like other additives.
5
Q
how is Acute Toxicity (LD50) done? what if LD50 is low?
A
median lethal dose (LD50): 要吃多少compound才会在2周内杀死一半的实验品。发现很低=很毒= rejected without further testing
6
Q
What are some species used to test for toxicity testing? why choose them? how about the second species used?
A
purebred lab rats: inexpensive, small, short lifespan, virtually identical genetically. 最好第二个实验品是primate, 但是它们endangered, expensive and difficult to work with.
所以过去第二个都用 dog：reasonable size, not expensive, reasonable to work with.
7
Q
what are some difficulties faced when choosing species for toxicity testing? what is done to deal with the difficulty?
A
实验品的 ages, sizes，gene 都不一样. 所以选purebred, often beagles. animals 比起人类可能对某些chemical 比较sensitive or not sensitive. 我们可以把他们当 model for toxicity, 可是还是要有加进safety factors.
8
Q
how is Short Term Toxicity done? what should be measured? p46
A
Normally in two species, measure the weight gain food consumption organ weights complete blood profile histopathological examination of organs
9
Q
What is the purpose of the short term toxicity?
A
喂食狗狗high level of the substance, 然后看看身体哪些地方有损坏，以后就知道研究这个东西时要注重哪一方面
10
Q
what does biochemical test determine? p46
A
find fate of compound in animal。在做chronic的时候，常常顺便做biochemical
Absorption
Distribution
Storage
Tissues accumulation
Metabolism
Enzyme profiles
确保某些物质不会在身体里造成伤害
11
Q
what is done to prevent toxicity in the body?
A
比较不用担心那些不会被absorb或被absorb后会被rapidly excreted的物质。liver 会试着 detoxify foreign chemicals. 它因为没有specific enzyme for everything it might encounter，所以它一般use a series of enzymes and try to add oxygen to the compound.大部分情况下毒素会降低，也有可能变得更毒
12
Q
what happens to the enzymes when tissues are damaged? how is it used in biochemical study?
A
和那个tissue相关的enzyme会在血里出现。所以analysis of enzyme levels 可以说明 chemical在哪里有cause effect. Ex: 血里有肝的enzyme=liver damage
13
Q
What does Mutagenicity tests try to determine? how is it done?
A
一个物质是否increases mutation rate. Treated and untreated animals mated and fetuses examined.
14
Q
what are some difficulties of Mutagenicity tests? how is it overcome?
A
在动物身上做：要过好几个generations才能发现mutation. 所以用 bacteria and human white blood cells 就可以短期内观察好几个 generations
15
Q
what is Teratogen? what does it cause? how is it caused?
A
compound that causes a miss-read in the DNA而造成birth defect, ex: thalidomide； 可能是发生在egg fertilize时，一开始的cell division
16
Q
what are some sources for Teratogen?
A
如果浓度够高，alcohol and vitamin A are teratogenic。ex: acne drug, accutane
17
Q
how are Teratogenicity studies done?
A
要在conception(受精）前喂食compound ，然后examine fetuses.
18
Q
how is Reproductive Studies done? what is observed?
A
Three generations of animals; observe
Fertility
Length of gestation
Live births
Still births
Body weights
Survival at 4 days
Gross abnormalities
不能加入会影响fertility的化学物，因为要看看哪些东西会增加或减少fertility。而且还要看length and outcome of gestation 是不是正常
19
Q
how is Chronic Feeding Studies done? how long is it done
A
和 reproductive studies一起，为了找 no effect dose. 2 years
20
Q
what is the No Effect Level? how is it related to Acceptable Daily Intake (ADI)? what is ADI?
A
level where NO harmful effect can be noted in the most sensitive species tested。no effect level/100= ADI。一个人一天内可以吃的最多的量
21
Q
why do we choose 100 when calculating ADI? what are some exceptions to that rule?
A
因为人类的实验不ethical, 所以在动物上做实验，然后假设人类被动物敏感100倍。但事实上是不太可能的。这个只是安全起见。但是有exceptions:
1. 如果有东西是 essential，可以加到 RDI的程度。有很多nutrient的 upper level > 1/100th the NOEL. 2. 如果一个东西cause cancer, the ADI is 0，除非有special legislative action要不然不能加
22
Q
what is Delaney Clause?
A
法律：如果发现是carcinogens，不能加进食物里
23
Q
how is cancer testing done?
A
for a lifetime, at very high concentrations - highest concentration that does not shorten the life span of the animal。在1000个实验品里用10的量如果没有结果，还是有几率这个物质会产生cancer，所以要加大量。这样做可能会高估，但还是安全起见比较好
24
Q
how is Ames test done?
A
一个很快的screening test。所有carcinogen会造成 mutations但不是所有mutagens是carcinogen。如果会造成mutation的才要做更多的测验。Ames test 用来测试 the ability of a compound to cause mutations in bacteria
25
what are the things we look at considering the testing safety of ingredients? p47
Conversion to toxic compounds
Excretion in less toxic forms
Evidence of non-absorption
Half-life and storage in tissue
Synergism and antagonism
Stress effect on different, sex, age and ethnic groups or disease states.
26
what are some problems faced when determining the safety of a compound? p47
Impossible to determine absolute safety
Can’t use human subjects
Extrapolation from animals to humans
Extrapolation from large to small doses
Cost
Safety of additive may be greater than food
Final decision comes down to judgment
27
what are some Acceptable Applications of food addictive?
Improve nutritional value
Enhance quality
Reduce waste
Improve storage quality
Enhance acceptability
Facilitate preparation
Make food more available
28
what are some Unacceptable Acceptable Applications of food addictive?
To disguise inferior products
To deceive the consumer
To provide otherwise desirable results that lower the nutritional value
To replace good manufacturing practices
To use in amounts greater than are necessary
29
what are the Most Common used additives based on weight of usage? what are their functions?
Sucrose; High fructose corn syrup; Dextrose (Glucose); Salt; affect taste/ 如果够多，preserve by lowering water activity
30
what additives cost the most and add the most value to products?
Flavors
31
what are some Preservatives? how are they labeled on packages?
antioxidants, sequesterants (molecules that bind iron and other minerals to protect flavor) and antimicrobial agents；它们必须要标签。label上面大部分的ingredient都不是preservatives（是nutrient/flavor) ,可是如果它是，就必须要写出来。
32
how did FDA try to regulate Dietary supplements? why did it fail?
如果说它们被当做herbal product然后像食物一样吃，那就是regulate as a food。如果是加在食物里或分开放，那就是 food additives or drugs。FDA 想要保证它们有所说的功效，可是因为公司反对，而且东西很赚钱，国会最终没让FDA这么做
33
what is FDA's power on regulating Dietary supplements?
制造商在marketing之前，不用证明安全性。如果要下架,FDA必须证明not safe
34
what is the difference between health claim and structure function claim?
health claim: must be proved
| structure function claim: requires no proof.
35
what are some myths and realities of herbs? p48
Natural is not equal to safe
Used for thousands of years is not equal to effective and safe
Herb as a plant is not the same as a capsule or tablet
All brands of herbs are not the same
36
what are some suggestions of The National Institute of Health? p48
Claims: Government 要控制 information; Congress 要要求 science-based supplement claims
Education：利用 media & editors to counter extravagant claims, 用有关 relevant professional societies 来增加 consumer awareness of how research works; develop consumer education modules
Understanding use：Prepare & implement detailed consumer studies, including extent of use & justification for children
37
what is the definition of Recombinant DNA? Genetic Engineering? p49
Recombinant DNA: Transfer of genetic material from one source into a living cell for replication and expression.重组DNA=原有基因+另一个DNA
Genetic Engineering - manipulation of the gene pool using biochemical techniques.通过生化方式改基因
38
how is biotechnology done? what is the goal? what is it used on? p49
把genetic info 从生物A身上取下来，然后用vector 放到另一个上，由此把new genetic material made into protein。这是为了在生物上加上trait，或者让它产生大量的valuable protein，又或停止一个protein的产生。用在medical
39
Why Study Biotechnology?
为了改变很多带有genetic成分的disorder, defects, diseases。还可以synthesize complex protein medicines
40
how was biotechnology done in the old days?
selective breeding for desirable traits in plants or animals, find mutants that can survive，最后大量繁殖
41
what are some common vectors?
plasmids and viruses
42
how does restriction enzymes work? how is it diff from other enzymes? p49
Restriction Enzymes - bacterial enzymes that cut DNA into pieces at very specific sites.可以把DNA切开的enzyme。大部分enzyme会把DNA切太小片，只有restriction enzyme可以切够大，才可以manipulate
43
how to select the right restriction enzyme to cut? how should the restriction enzyme cut the gene?
如果知道gene的base sequence还有material on either side，就可以选出来。如果enzyme剪在gene的中间，会把它inactivate。所以如果要选gene of interest, enzyme就必须剪在near ends of gene
44
what is PCR (Polymerase chain reaction)? when is it used? what are the characteristics?
做很多DNA copy的其中一种方法。用在small or old samples。ex: minute samples。fast and specific.例如信纸上的口水
45
what is RFLP (Restriction fragment length polymorphism)? how is it done? p50
a technique that looks for patterns in DNA。当 2 alleles differ in 1 base pair, restriction enzymes 会把DNA切成很多块。
46
how is RFLP (Restriction fragment length polymorphism) used? p50
比较两个DNA的pattern可以看出来是不是从同一个人来的。也可以用来看是不是有些pattern只有在患有某disease的人身上才有，而其他人没有。按道理说，如果可以放进去那个不好的gene 的 functional form，病就可以治
47
what is the diff between sense and anti sense strand? p50
sense: 正确的protein code, 被复制的。anti: 不正确的；和 sense相反，帮助复制
48
how is Flavr Savr Tomato preserved? what are the advantages and disadvantages?
sense and antisense RNAs are complementary 所以会绑在一起。在一起时就不能做 protein。在番茄里加入 antisense之后，会把它变soft 的 enzyme就没用了。 好处：nothing is added. 坏处：只能拿走某些特性，不能 add new。
49
how can the technology of Flavr Savr be used on medical stuff?
移除characteristics of cancer cells that cause them to divide uncontrollably
50
how can biotechnology be used on heart attack?
artery 里的 blood clot 是心脏病其中一个原因。可是当身体试着dissolve时，病人已经heart muscle严重damage或已经死了。Tissue Plasminogen Activator (TPA)：和人类生产的protein一样，可是一次性high concentration注射几秒内分解clot
51
how was diabetics cured in the past? how about now?
以前用从pig pancreas拿出来的insulin，因为和人的很像，而且效果一样好。现在，把人类insulin放进bacteria里，product和人类的一样
52
how were children with hemophilia 血友病 used to be treated? what was the danger during the AIDS epidemic？
从别人血里得到clotting factor，可是要很大量的血才能得到足够的。所以受血人有高风险收到virus。EX: AIDS epidemic时期,有血友病的男生最高infection rate。
53
how are hemophilia treated now? why not just change the genes all together?
clotting factor 由 genetically engineered bacteria 生产，因为是生长在blood stream里的agent 所以没有infection几率。repair genes 比生产 protein medicine (TPA or EPO) 慢
54
what are some FDA policy conditions for food that use genetic engineering? p50
要 characterized有哪些genetic change。
Stable enough to minimize rearrangements (基因不可以move around)。
Toxicants and anti-nutritional factors要和正常的一样或更少。Nutrient levels要大于或等于，不可以少了bioavailability.
55
what are some requirements for adding new substances in genetically engineered food? p50
平常食物里没有的东西需要 Pre-market approval, 要被当成food additive测试和label。如果new protein是从常见的allergenic source来的，那么它也会被当成allergenic所以要label。（可能还要其他action）
56
如果一个食物本身没有注明是genetic engineering，可是在那之后产生了的蛋白质是本来食物里也有的，需要标签吗？为什么？
no; nothing has been added to food that was not there before
57
what is Chymosin? where is it from? what was its function?
用来做cheese的enzyme。calf stomachs。使milk proteins形成 clot or curd，帮助calf消化，还可以制作cheese。
58
why is there no label needed for chymosin？
chymosin 的gene被放在bacteria里面，用来制作和calf生产的一模一样的identical enzyme。没有一个test可以分辨是从牛身上还是microbial来的。
59
what is the first food additive produced by genetic engineering approved for use in the United States? what is the FIRST genetically engineered food approved for sale in the United States?
Chymosin; Flavr Savr Tomato
60
what are the policies regarding biotech used by many European countries? what is an exception food that is produced by biotech and that is it not labeled? what could be some reasons that the Europeans have such regulations?
如果用了生化技术，虽然是safe，还是要label。制作cheese用的rennin是生化做的，可是没有label，因为和原来的一模一样。ways to try to get around free trade treaties and to protect European farmers against more efficient producers.
61
How were tomatoes collected in the past? what is the disadvantage?
green的时候在florida或california采集，然后运输。（如果ripe的时候采会太tender而不适合运输）要卖的时候把ethylene gas（番茄也是用这种化学物成熟的）洒在green tomato上，而使它成熟。可是如果番茄不是在vine上面成熟，就没有optimal flavor and texture
62
what is the new way of producing tomatoes? i.e. the Flavr Savr? what are the advantages?
用antisense的技术genetically engineer番茄，使它们生产比较少让它们soft的enzyme。所以采集时red and flavorful，但是硬的。过了一个月之后就可以软了吃了
63
why are the Flavr Savr not labeled? what is its competitor?
nothing was added。只不过说一个本来就在的enzyme被慢下来而已。green house grown tomatoes: 一样价格。
64
what are some methods to control European Corn Borer? p51
```
Nothing: 如果infestation太小
Pesticide
Natural enemies：没有有效的
Breed resistance into corn
Genetic modification
```
65
what are the disadvantages of using pesticides as a method of fighting European Corn Borer ? p51
non-specific: 把beneficial和harmful的虫全杀光。也可能对bird toxic (但那些鸟会吃坏虫）。rain会把pesticide冲进drinking water。finished product也可能含pesticide.
66
what are the disadvantages of using breeding as a method of fighting European Corn Borer? p51
通过Breeding 产生insect resistant的植物。但是它们会生产一种有毒的 natural defense (chemical)。而这些毒往往比 pesticide residues还厉害
67
what are Bacillus thuringensis? how does it work on caterpillars? birds and mammals?
Bacillus thuringensis: soil bacteria。常常被caterpillars吃掉，然后在它们的digestive tract里产生toxin最后杀死它们。只对某些有效，对beneficial insect没用。被birds or mammals吃掉也只是被当做protein
68
how was Bacillus thuringensis used in the past? what are the advantages and disadvantages? how is BT used in the present? what are the advantages?
farmers spread spores of BT, caterpillars吃了之后死掉。inefficient and expensive，but environmentally friendly。现在，BT crops 被genetically engineered来生产BT toxin。只对某些caterpillar有效（只有东西想偷吃时会被杀掉），对其他生物没有影响。
69
why are Bacillus thuringensis BT crops not labeled?
BT和植物从soil里吸收的toxin一样，和植物本身里的也一样
70
what is Roundup Ready? what are the advantages? p51
roundup 是一种 herbicide（除草剂）, 阻止一种帮助photosynthesis的enzyme。杀green plants，可是对不用光合作用的植物无害。对动物无害，而且roundup里面的chemical在sunlight下breaks down。
71
how does biotech works in Roundup Ready plants? p51
找到了一个enzyme的gene对roundup resistant，然后加进food crops里面。所以洒roundup的时候只有weed会被除掉。
72
how did the FDA rules the Roundup Ready plants?
改变后的enzyme变化不够大，于是不需要label
73
what are some problems to those countries that eat rice? where is this problem most commonly seen?
有些地方主要吃的是rice,可是它很少 Vitamin A。third and poor country 常常有xeropthalmia and blindness
74
how is golden rice genetically engineered? how does it help the body? how is it going to be used in the future?
里面加了3个gene,这样米就可以做beta carotene，而身体可以把它换成vitamin A。会免费给需要的国家，但还要看看有没有被accepted。
75
why does salmon not grow in cold?
在冬天没什么东西吃，不够食物支持growth。它有一种gene控制production of growth hormone是cold sensitive。冷的时候不生产这种hormone,然后salmon就不会长。
76
how are salmon modified to make them grow in cold? what are the advantages? is it approved by FDA to sell yet?
从一种叫pout的鱼身上弄promoter放进salmon里面。promoter不是temperature sensitive，所以salmon可以一年都产生growth hormone。可以在half the time and cost拿出去卖。还不能卖
77
what are the categories of immune system?
1. Innate or non-specific
| 2. Adaptive or specific.
78
what is an antigen?
Antigen = antibody generator (immunogen). 身体没办法recognize的一个大的 molecule (几乎都是protein)。所以被当做是会cause harm
79
what is antibody? how does the body use it? what are the disadvantages?
身体做的special plasma proteins that can bind to very specific antigens. 用来 neutralize foreign invaders. 它们很 specific in action, 可是要花时间和energy让身体identify invader 然后做相应的antibodies.
80
what is Immunity?
resistance to specific invaders。can occur naturally by being exposed or through a vaccination
81
what is Active Immunity or Secondary Immune response? p53
results from the stimulation of the body to produce its own antibodies. 通常比较 long lasting.
82
what is Passive Immunity? p53
以ready made antibodies 的形式 transfer immunity。antibodies from a foreign source to a specific antigen may confer passive immunity for a relatively short period of time.
83
when does Non-specific defense mechanisms occur? what are some examples of the body’s defense?
antigen入侵后，它们的chemical properties启动了innate immune response。physical barriers: skin/oil, sweat/lysozyme。chemicals in the blood: interferon, White Blood Cells -Macrophages, Complement, inflammatory response
84
how does nonspecific defenses compare to the specific ones? for example, how does the skin works? p52
less effective against a determined invader, 可是可以用low cost对付几个potential causes of disease。skin像是一层防护罩，破了的话更容易infection。皮肤里的Oils 是另一层 barrier，同时保证skin supple，防止cracking that can lead to infection.
85
how does sweat protects the body?
Sweat包含一种enzyme, lysozyme,用来break apart bacteria. 不能杀掉所有的，但对很多有用
86
how does white blood cells (macrophages or phagocytes) protects the body? what are its targets?
search the body for foreign cells and consume them. 可以是bacteria, viruses 或是严重damage而不能function的 body cells
87
how does inflammatory response protects the body? p52
The damage to tissue 释放出几种 chemicals包括 histamine：它让周围的blood vessels permeable （渗水）to fluid and white blood cells，导致 swelling and the heat (fever). The white blood cells search for foreign invaders and also consume damaged tissue so that repairs can begin.
88
how is Histamine used by a number of systems within the body as a signal?
it must be released at the right time in the right place. 在 inflammatory response的情况下，它会把macrophages 带去感染的地方。Histamine makes small blood vessels more permeable，让fluid and blood cells accumulate 在感染的地方
89
what are Interferons? what are its functions? for example? what are some common symptoms? p52
身体做出来的proteins that act as antiviral and anti tumor agents。communication between cells, activation of cells to trigger the immune system。释放出来后警告周边的细胞有virus。aching muscles and fever
90
what is the function of The complement system?
帮助antibodies and phagocytic (white blood cells) cells防御。part of the non-specific immune system, 也可以 brought into action by the specific immune system.
91
how does the Adaptive or specific immunity work?
1）身体要process and recognize antigen。2）创造 immune cells specifically designed to attack that antigen。3）"memory" (clonal selection) 使未来response更有效率。
92
where are Lymphocytes (B-lymphocytes or B-cells) produced and matured? what do they do? what are their limitations? p52
blood marrow from stem cells; humoral mediated immunity: B cells make antibodies that will react with foreign molecules within the fluids (the blood and lymph)。只能在bacteria上用，不能用在virus上
93
where are Lymphocytes (T lymphocytes or T cells) produced and matured? what do they do? p52
bone marrow from stem cells and mature in the thymus; cell mediated immunity: T cells make antibodies that react with antigens found on the surface of body cells。（它们是从细胞自己身上的，或从那些攻击细胞的virus那里来的）
94
what are the two types of T-cells?
Killer T (cytotoxic response) and helper T cells
95
how does B and T cell interact with a specific foreign molecule? p52
specific protein molecule in its plasma membrane
96
how do antibody bind with antigens? how many antigens can one antibody bind? what is clonal selection? p53
在antibody上面的hydrophobic groups有不同的shape, charge和distribution，使它们interact with only a few molecules。两个structure越吻合，两个molecule的interaction越好。一个可以绑2-10个。大部分T or B cells 不会碰到protein紧紧绑在它身上的。可是如果真的碰到了，细胞recognize那个molecule，然后divide and copy。
97
When the cells grow and divide, which two types of cells will be produced?
effector cells and memory cells
98
under what circumstances is effector cell produced? what are the traits? what are the functions?
第一次遇到的antigen引发primary immune response，产生大量 antibody，只生存几天。只有几个细胞有正确的receptor。大概要花一个星期身体才能解决invader。不能prevent infection, but help stop it.
99
what is the function of Memory cell? under what circumstances is it produced?
在effector cells divide的时候, 也产生memory cells. Memory cells 不会立马产生antibodies, 可是生存很久。
100
In active immunity (secondary immune response), what happens when the same pathogen is detected by memory cells?
memory cell会reproduce。身体做更多effector 和 memory cells，这样可以更快做更多的antibody。因为身体没办法有够多 B and T cells来prevent infection，第二次expose时，通过制作很多memory cells，身体可以在infection发生前赶快respond （在一个人知道自己expose前，身体已经自己治好了）
101
how can active immunity (secondary immune response) be obtained?
naturally or vaccination.
102
what is the disadvantage of active immunity (secondary immune response) ?
prevent but does not stop
103
how is vaccination done? what is the booster shot and when is it used?
injected with killed or greatly weakened and non-infective form of the disease. 然后身体做 antibodies and memory cells防御。有些疾病很少接触, 需要 booster shot 来 activate the memory cells so they can produce a new generation of cells.
104
which cells do the cytotoxic response uses?
T-cells: helper and cytotoxic or killer T cells.
105
how does a virus affect cells? how does white blood cell attempt to counter virus? p53
Viruses 感染细胞后在里面reproduce，当cell rupture后，virus 进入 blood stream。antibodies 还没来得急除去它们，它们会跑去别的cell reproduce。被感染的细胞会试着除去invader。有些会被 white blood cells 消化, 可是它们生产太快没办法全部除去。 virus 被white blood cell吃掉后, 它的一部分会和special protein合并，然后跑到cell的surface，由此activate T-cell system.
106
how does helper T cell work? what are its limitations? p53
activating and directing other immune cells。白血球表面antigen和special protein被helper T cell recognize，召唤killer T。在 blood or lymph 里面的就不会被发现。
107
what are the functions of Cytotoxic T (Killer T-cells) ? how does it work? p53
T cells 可以找到 proper receptor molecule on infected cells。找到在细胞表面上的antigen后，它会开始 clonal selection 然后生产 effector and memory cells。T cells 靠近infected cells 然后生产一种叫 Perforin 的 protein，用来弄破细胞的cell membrane 使它们死掉。死掉的细胞和invading organisms一起被 macrophages吃掉。阻止 viral particles感染其他的
108
how is AIDS (Acquired Immune Deficiency Syndrome) caused? why is it hard to prevent?
HIV (Human Immunodeficiency Virus) 攻击 Helper T-cells。它们本身没办法繁殖，必须要感染其他cell来复制。比其他virus难杀因为它攻击immune system本身
109
how can passive immunity occur? when is passive immunity used? what are some examples?
maternal antibodies 通过placenta或artificially给 fetus，可以保护他们到可以自卫时。有的时候是通过 injection。当有 high risk of infection 或不够时间让身体 develop its own immune response（polio and tetanus，身体还没抵抗就死了）。
110
what are the advantages and disadvantages of passive immunity?
immediate protection, 但是身体没有 memory,所以一个人之后还有可能被同一个pathogen感染
111
how does Autoimmune diseases happen? what are some common Autoimmune diseases?
身体产生antibodies针对正常的 proteins然后摧毁健康的tissue。Multiple Sclerosis, Crohn's Disease Ulcerative colitis Diabetes mellitus, Rheumatoid arthritis Systemic Lupus Erythematosus
112
how do allergies occur? pg54 what are the consequences?
antigen刺激 IgE（一种antibodies) 的生产。IgE 绑在mast cells上，碰到过敏源，mast cells释放histamine 和其他 inflammatory substances。
Histamine导致dilation of blood vessels and fluid accumulation= shock and death.
113
T/F foods must interact with the immune system to stimulate mast cells in releasing histamine
F Some foods may stimulate mast cells to release histamine without interacting with the immune system
114
what is Anaphylaxis?
很严重的过敏反应：acute, often severe, and sometimes fatal immune response
115
how is RAST test (radioallergosorbent test) done? p54
用 immobilized antigens 来查看有没有specific antibodies
116
how is Skin test done? p54
rapid test for sensitivity to various allergens. 用prick 把 allergens 放skin里面，然后看一个小时后有没有 swelling
117
how is Cytotoxicity test done? how is it accepted by public?p54
very popular but doubtful validity。把blood samples 和 food extracts放一起，然后看白血球polymorphonuclear leukocytes 有没有abnormalities .
118
what are some common allergic sources?
Milk, Eggs, Tree nuts, Crustacea (shrimp, crabs, lobsters), Legumes (peanuts, soybeans), Shellfish (clams, oysters, scallops), Wheat, Fish
119
what are some Common Respiratory Symptoms of Food Allergies? Gastrointestinal? Cutaneous? Other ones? p54
respiratory:
Rhinitis - runny nose; Asthma
Gastrointestinal:
Vomiting, Nausea, Diarrhea
Cutaneous:
Uticaria - hives; Eczema - skin rash; Atopic dermatitis - skin rash
Edema - 大范围严重swelling；Anaphylactic shock-可能致死；Headache
120
Examples of Extreme Sensitivities to Foods by Allergic Individuals？p54
1) 用同一个utensil 拿多种食物
2) 食物用具没洗干净
3) 碰到食物的utensil或package
4) 煮东西的时候inhale
5）kiss刚才吃过过敏源的人
6）breast milk
7）在intercourse时，通过sperm传播
121
how to track down a food allergy?
1) food diary: 吃的东西和时间
2) 写下symptoms和持续时间
3）看哪些食物符合哪些symptom
4）知道一些可能性后，看看哪些吃了之后是没反应的
5) 试试把怀疑对象去掉，然后看symptom有没有消失
6) 如果不是太危险的symptom，让别人帮忙准备食物,用blind test
7）还是没用的话可以做 RAST or skin test
122
how is Food hypersensitivity different from true allergies? how are they similar? who are the victims of deaths caused by ingestion of sulfite? causes?
similar symptoms。它不是由immune system mediate, 所以IgE 没有增加, 也不会去用 RAST。 大部分人是asthmatic,或是用steroid的asthmatic subset。不知道什么造成的，只知道不是IgE。
123
what is the cause of cancer?
可以divide forever，可是每一次分解有 mutation的可能性，所以无限分解造成accumulation of errors in genetic material。
124
how are cancer cells diff from normal ones in the way they reproduce and function? what is contact inhibition?
一般细胞只能分解几次然后死掉，可是cancer cell的mutation没有这个障碍。contact inhibition: 如果细胞A碰到细胞B，B会散发出一种molecule让A停止divide。可是cancer cell mutate之后，丧失了contact inhibition，不管多crowded继续divide。
cancer cell不工作，只是consumes nutrients and grows。没有specialized或differentiated，没有特别功用的细胞
125
how can one tell that it is mutation that leads to cancer?
癌细胞的变化会传到它们的offspring，说明变化在DNA
126
mutations can be caused by which factors?
食物和环境里的 Chemicals，UV 和 radiation，Viruses
127
how does the body normally deal with mutated cells?
mutated cells会改变它们metabolize的方式，如果这个变化是harmful的，它们会死掉，身体会replace the mutated ones with a healthy one
128
how does cell know when to grow or stop growing? how does this change when there is a mutation?
有些gene控制proteins that regulate growth。它们会用signal告诉细胞长/不长。mutate之后gene不能正常运作
129
what is the relationship between Proto-oncogenes, oncogene and ras oncogene? are proto oncogenes designed to cause cancer? p55
如果变成oncogene后，可能会造成mutation。ras oncogene是其中一种oncogene。NO
130
how does Ras Oncogene cause cancer? could it have been stopped? who would most likely get cancer and why?
告诉cell一直divide。一般在健康的细胞里会有其他protein阻止，可是如果连他们也mutate，就有可能有cancer。一般要多个key protein mutate才会造成cancer,这也是为什么old people比较有可能。因为他们的cells活了很久，所以有可能accumulate the mutations
131
what happens when Ras Oncogene is in bladder tumor form?
a point mutation has changed a codon from GGC to GTC. Protein replaces a glycine with a valine
132
what is the function of tumor suppressors? what happens when it has mutation? what is p53 and its function? p55
proteins that determine if a cell has too much damage to its DNA to function normally.如果太多damage的话就把细胞杀了。可是如果这些gene有mutation，就不能生产 tumor suppressor, 所以不能防御。p53 是其中一种 tumor suppressor，控制apoptosis 来杀死坏细胞
133
How can lowering body weight reduce chance of cancer?
Excess calories = Increased metabolic activity. More cells = More risk for cancer. Caloric restriction = Less cancer
134
How can Eating A Varied Diet reduce chance of cancer?
dilute toxic effects of any given food and 增加吃到beneficial food的可能性
135
How can Eating Fruits and Vegetables reduce chance of cancer?
Antioxidants: Protect DNA from mutations。 Enhance carcinogen detoxification
136
How can Eating High Fiber reduce chance of cancer?
防御 Colon cancer。Dilutes harmful substances (carcinogens), Binds carcinogens like bile acids, help regulate colon cell growth
137
How can reducing Total and Saturated Fat reduce chance of cancer?
防御 Hormonal cancers: breast and prostate， Avoid saturated fats (animal products). Include unsaturated fats -mono and poly
138
How can reducing alcohol reduce chance of cancer?
Esophagus, pharynx, and mouth cancer 多多少少和酒精有关。Helps carcinogens enter cells
139
what kind of cancer would Salt-Cured, Smoked and Nitrite Preserved Foods cause?
gastric cancer in Japan
140
how does Curing/Smoking cause cancer?
Smoked (Polycyclic aromatic hydrocarbons) Curing (Sodium nitrite and nitrate) form carcinogens
141
can cancer be reduced by dietary modification?
机会不大
