34

There are different polio vaccines - one live (attenuated) vaccine which is given orally and one inactivated, which is injected. The main reason for using the live orally vaccine is that it provides excellent immunity (better than the inactivated) since it uses the natural infection route (oral-faecal) in the body where it enters through cells in the ...


22

High oxygen concentration can be deleterious; it can induce oxidative damage. The systemic blood circulation would supply oxygen to the "oxygen-deprived" lung. Moreover, Mycobacteria can survive in anaerobic conditions. And what if both lungs are infected? There are many flaws in the proposed therapy. Adding this point from one of the comments below: ...


7

The accepted answer is correct but I would like to point out a misunderstanding that has to underly the idea that this would work: In reality lungs aren't a magical one-way gate for the various gases. Lungs do not extract oxygen from the air, they permit oxygen exchange between the air and the blood. Since the air normally has a higher oxygen level than ...


6

The reason why the oral polio vaccine is not digested in the stomach is that the poliovirus itself has adapted such that it can survive the acidic conditions of the stomach. By using an attenuated (mutated to not cause neurological symptoms) version of the virus, the oral vaccine can also survive the acidic conditions of the stomach. For TB which is ...


5

What a great question! I'm sorry to add another blow to your theory... but... Even if oxygen depletion would be effective, treating the lungs alone is not good enough. True enough, Mycobacterium tuberculosis bacteria usually attack the lungs, but TB bacteria can also attack other parts of the body such as the kidney, spine, and brain (Fig. 1). If not treated ...


5

First there is one major difference between HIV and TB: As long as the TB bacteria are still susceptible to treatment (which is developing into a major problem in some regions of the world) there is a effective treatment which can eradicate the infection. For HIV this is not possible. Here we can only lower the viral load (sometimes under the detection limit)...


4

If you read this article, you will find that CD4+ and CD8+ T-cells are probably the major mediators of the immune response against M. tuberculosis. Since HIV severely depletes the number of CD4+ T-cells (and to a lesser extent other kinds of lymphocytes), it stands to reason that the frequency of infection and virulence will be substantially increased in ...


4

Thats an interesting and complex question. First, Mycobacteria tuberculosis is present for a long time in the human population and evolved to evade our immune system. One of the keys are glycolipids and sugars which are part of the bacterial cell wall. These either help suppressing an immune response or help the bacteria to enter host cells in which they can ...


3

As stated by others, polio is primarily a gastro bug, an enterovirus related to Coxsackie and a number of others which produce stomach and respiratory symptoms, as well as various others. Most polio infections result in nothing worse than a case of "the stomach flu", but in a small percentage of cases the virus escapes from the GI tract and produces ...


3

The most evident problem I can see for this TB treatment is that mycobacteria can survive without oxygen. Latent TB (a person is infected but doesn't have active TB) is one of the major problem in the treatment of TB and one-third of the world's population has latent TB! (http://www.who.int/mediacentre/factsheets/fs104/en/). A new TB treatment can only be ...


2

This is an interesting an useful question about host-pathogen interactions. For a general reference (for both hosts with and without a competent CD4+ T-cell response) see Cecil Medicine, Ch.332, and Murray Medical Microbiology, Ch. 28. There is also a decent review in Lancet Infectious Disease that discusses the pathophysiology in immunocompromised hosts. ...


2

I think its a bit difficult to compare HIV and TB this way because TB is transmitted mainly through respiratory droplets whilst HIV is mainly through contamination of blood products/sex, etc but not via the respiratory route. As far as I know, there's still a likelihood of TB transmission from a treated patient to an untreated patient. TB is quite complex, ...


2

Mycobacteria are on the order of 2µm in length and 0.2µm in diameter. Alveoli are on the order of 200µm in diameter. Obstruction is possible, but M. tuberculosis grows rather slowly. Too slowly, in fact, to avoid being engulfed by alveolar macrophages. Furthermore, obstruction does not sufficiently explain the predominant symptoms of tuberculosis: ...


1

The statement in the question about the current distribution of these diseases is not strictly accurate, as shown by the graphic below. [Malaria graphic: Wikipedia user, Percherie (2006); TB graphic: Corbett et al. (2003)] However there is no disputing that the contemporary and historical geographical distribution of these diseases differ. Why? The crux ...


1

Direct transmission is through direct contact with the infected person with no intermediary or vector. The Ebola virus and AIDs virus are examples. Indirect would be malaria spread through mosquitos, plague via rats, etc. The common cold spread through droplets in the air could seem indirect, but because of the proximity required, the CDC website lists it ...


1

You've picked a fascinating and very important organism to study. Unfortunately there are many many steps with many software packages that you'll need and each next step will depend on what you find making any particular tutorial nigh on pointless. I'm sorry to say that I don't think anyone will dump an entire project proposal or workflow as an answer. I'll ...


1

The question asks PPD test in patients without M.tuberculosis. It does not say if the patient has previously had infection with M.tuberculosis. I think this question implies that the patient has never had before infection with M.tuberculosis. I am not sure how it can be in reality possible for adults, since M.tuberculosis spreads in air. The reason for ...


1

Extension to Kanchi's answer by using Murray Microbiology textbook Dissemination to any body site occurs most commonly in immunocompromised patients, like HIV patient. CD4+ and CD8+ T-cells are the major mediators of the immune response against M.tuberculosis. Since HIV severely depletes the number of CD4+ T-cells (and to a lesser extent other kinds of ...


1

I think one reason for greater virulence is the fact that M.tuberculosis prevents fusion of the phagosome with lysosomes. I think this picture is little relevant here I am thinking what is happening in these two parts here: This answer does not provide enough support why there is greater virulance in HIV patients than in normal people. And particularly ...


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