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BIOL 2900 (72)
Lecture

Week 9- Nov 7 notes _BIO 2900.docx

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Department
Biology
Course
BIOL 2900
Professor
Motti Anafi
Semester
Fall

Description
 Bacterial Endotoxins -Bacterial protiens (enzymes) -Destory hsot cellulat structures  A-B toxins (PHOTO) The active (virulent) portion is attatched to the binding portion which can attach to the cell surface allowing the active portion to enter the cell. The goal here is to prevent the binding protion from attaching to the surface of the cell wall. You can do this by having antibodies (Ab) attack the binding site leaving the active part without function.  Toxin to Toxoid Through chemical modification, the active portion of the toxin becomes inactive. The binding portion of this toxin is unaffected. The toxoid is used in vaccines (ie: tetanus and diptheria) where a live agent is not possible. The antibodies can then recognize the binding site of the toxin (after exposure to the toxoid) and will be able to fight the virus  Toxoids: 1) Diphtheria: Inactivated toxin (toxoid) - does not cause major damage; needs a viral infection of the bacterial cells in order to cause serious damage - inactivated toxin (toxoid) - bacteriophage - virus; places its own viral DNA into the bacteria - the toxin is encoded by a bacteriophage (genome of the bacteriophage makes a toxin) only bacteria infected by virus can make a toxin. Bacteria uses its own ribosome to translate the genes of a bacteriophage. 2) Tetanus: example of bacteria that make toxins). Bacteria its not a problem, toxin is a problem. we need to control toxin.Toxin can be activated against the antibodies. In other words, for example, if you step on a nail, the bacteria gets into your flesh therefore the bacteria now inside is secreting toxins that will cause damage to us. So we need to control or stop the toxin secretion. we need a boost every 10 years for diphteria and tetanus to make sure that the vaccine is acting.  Sub cellular/Small Fragments Vaccine (PHOTO)  HBV vaccine – A fragment vaccine*** - HstAg - 1 generation – extracted from the blood plasma of HBV pts. - Today: cloned in yeast - Hep B can be prevented st - The 1 vaccine against cancer (poten liver cancer – much more aggressive - given to the newborns whose mother is Hep b carrier - virulent virus  How do you get Hep B? 1) Blood 2) Sex- STIs similar to HIV - Vaccinations may prevent the above - There is no way to clear these virus at this time - Birth: vaginal delivery( no antibodies to potect babies and fight against HBV) therefore babies require shots 3) Birth – Babies of mothers who are carriers have no immunity against Hep B Baby shots for Hep B (CDC recommendations) Birth (if mom HBV +) - Hep B vaccine (Epotox – purified subU vaccine – cloned in yeast) + H-BIG: Hep B immune globulin, Passivel delivered Ab that provides “instant” protection against HBV.+ 1-2 months old: Hep B vaccine – Booster + 6 months old: Hep B vaccine If mom is not HBVthen the baby would get Hep B vaccine at 6 months, can be delayed 19 out of 20 babies who get the shots will be protected for life; but periodically need to check for immunity, and if the immunity is decreased, need to get another 2 boosts of vaccination.  HPV disease -cervical cancer affects half million each year world wide -99% of all cervical cancer arise from HPV -our immune systen usually takes care of it and we dont even know we are infected -pap smear detects abnormal cells before they become cancer (Bauman, 2012, p 497) - It is a very common sexually transmited disease -> Skin to skin with infected person -> through kissing, touching and intercourse. - including the penis, scrotum, vagina, vulva and anus. - There are over 100's strains of the virus and 3/4 adults will be infected with the virus at least one time in their life. - When a woman becomes infected with the virus the cells in her cervix change and become abnormal. With a simple pap test that done by a gynocologist they can figure out what strand of virus it is and if it is cancerous or not. - Signs and Symptoms - Many people may not have any signs and symptoms and can live their lives not knowing they are carrying the virus - Others may develop genital warts, cervical cell abnormalities and or cervical cancer. - Warts can be removed however the virus will always remain in your body. (side note) According to the WORLD HEALTH ORGANIZATION, approximately 500 women will develop cervical cancer and out of those women 140 of them will die from the disease.  HPV vaccine - protects us from cervical, anal, penal, head and neck cancer - Made up of potent without genome that looks like a virus, our body recognizes it as Ag [made by making a protein from the surface of this virus. When making this protein in a tube, the proteins recognize each other and form a ball. TH ebody will recognize it and make Abs against it] - Made up of 2 impo cancer causing strains: 16 & 18? - level of protection: 100%, 100% protection against strains the vaccine precents 80% cervica cancer in general -better protection than what your body could do on its own without the vacine  Recommended Immunization schedule for persons aged 0-6yrs:- CDC website - 0-6 months – Maternal Abs  Pre-Post vaccine incidence of common preventable diseases: Diphtheria, polio are totally eradicated by vaccine VIRUSES - Viruses are the most common cause of the acute infections in human - Many viral diseases can be viewed as a failure of the virus to adapt to its host Viruses are the most common cause of acute infections in human: o Rabies, Ebola have high mortality rate, although most viral infections are not severe o several billion people are infected each year o Sometimes viral infection can lead to long-term disability - Rubella, this virus infects fetus and a child will show signs of mental retardation. 25% of people diagnosed with schizophrenia had mothers who were infected with Rubella during pregnancy -Polio, when a person is older and losing neural activity the symptoms of infection reappear o Virus is the simplest, tiniest form of "life" on earth o Their only goal: to reproduce o Fifty percent of all contamination in work or school is related to viral infections. o In children, there are 7 or more viral infections per year which leads to a visit to the physician; in most of the cases it will be a viral infection and parents will be advised to keep the children at home for a week or so and the child will be okay. o The total viral infection in the world is several billions every single year. Although most viral infections are not severe and are not likely to result in death; some such as Rabies (e.g., Symptomatic Rabies), Ebola have a very high mortality rate. Ebola has a 90% mortality rate. Rabies (if untreated and developed into symptomatic Rabies) will lead to death in 100% of the cases. o There are also some situations where viral infection can lead to long term disability. For instance, Polio is a disease which will ‘stay for life’; even after a child has some sort of recovery, even if the virus is not present the child who was previously infected may lose of some neuronal activity with age (e.g., adulthood) and symptoms associated with the initial infection may become apparent. o Rubella is not a disease that is going to cause a major problem to any of us; unless a pregnant woman (1sttrimester) becomes infected with the virus. In the event a pregnant woman becomes infected then the fetus is likely to have developmental problems which will become apparent in the child later in life. It could be mental retardation or other related side-effects of the virus affecting neuronal cells. It is suggested that 25% of people with Schizophrenia were born to mothers that were infected with Rubella. o Rubella infection is going to be a problem for life (e.g., long-term disability). Bacterial Exotoxins - bacterial proteins (enzymes) - destroys host cellular structures - made up of 2 functional portions; one the active causing damage to the cell but will only take place if the binding side is attached to the cell - ***binding toxin must be preset for cell damage to occur - if the binding cell does not attach damage reaches a dead end **Viruses are the most common cause of acute infections in humans. The Origins of Virology 3700 BC, Memphis, Ancient Egypt o typical clinical signs of paralytic poliomyelitis ( look at his left leg) o standing in a weird pose, one leg smaller and on crutches o similar to polio symptoms o 90% are asymptomatic 1143 BC o Ramesses V's preserved mummy shows that he dies from smallpox at 35 years old in 1143 BC o Looking at face, has blisters o DNA was sequenced from his face and small portions of smallpox were found 1000BC China o Small pox was all over the world but mainly far east o Variolation - taking crusts from someone who had sma
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