Hot answers tagged

76

No, this is not possible. There are a few reasons for that, but most important are that the only thing a mosquito injects is its own saliva, while the blood is sucked into the stomach where it is digested. To be able to infect other people HIV would need to be able to leave the gut intact and then also be able to replicate in the mosquitos which it cannot ...


24

It is possible for viruses to live in mutualistic relationships with their hosts, these associations are often overlooked due to the devastating effect that many viruses can have. To give an example in humans, when HIV-1-infected patients are also infected with hepatitis G virus, progression to AIDS is slowed significantly (Heringlake et al., 1998; Tillmann ...


17

This is because rabies is a viral infection of nervous tissue that propagates through peripheral nerves into the brain and causes brain tissue inflammation (encephalitis). As long as the virus is in the brain there is no way to get rid of it. The main trade-off here is that everything that would kill the virus will be as (or even more) aggressive against ...


16

This is probably a fly killed by the fungi Entomophthora muscae (or closely related) or maybe a Cordyceps fungus. These kinds of fungi mainly attacks insects, and you sometimes see attacks as white, swollen abdomens in flies. (Picture of common infection, from bugguide.net) These fungi are also known to change the behaviour of infected individuals, so ...


15

I think no one can really deny the existence of HIV or AIDS, just a search on google scholar will show >1,500,000 hits for each of those terms, and ask (hopefully any) doctor and they will say it does, though AIDS denialists do debate whether HIV causes AIDS. This paper explains the process of HIV causing AIDS. Further, AIDS denialists have not offered up ...


13

A mosquito's proboscis isn't like that of a butterfly, which could easily have nectar clinging to it when it is coiled up; instead, consider that the part of the mosquito's proboscis that enters a blood vessle is probably wiped clean when it is retracts outward through the epithelium. A a dirty needle or razor is many, many times larger than the sucking ...


12

Alright, having read the citation linked, and doing a little poking of my own, here's my approach at an answer: Some human herpes virus infections may compete with HIV infection. Essentially, some strains (not the ones you normally think of) infect CD4 cells - the same cells targeted by HIV. These strains down regulate transcription in CD4 cells, which in ...


12

Yes, plants of all sizes can have cancerous growths. Agrobacterium tumifaciens, the causative agent of crown gall disease, produces what is called a tumor. See this link for detailed information on these growths. Alternatively, use a plant physiology textbook to look up the above terms. (Here, is where a textbook is better than a single abstract in PubMed.) ...


12

This is too long for a comment, so I put this in here: The main reasons are sociological. From the data I have read so far, this outbreak (actually these are two independent outbreaks, one in West-Africa and another one -not connected- in the Democratic Republic of Congo) is not exceptionally deadly in terms of Ebola. The death rate is about 60% which is ...


12

Short answer People with androgen insensitivity syndrome do not have a functional uterus and cannot bear a child. Background Androgen-insensitive genetic males may develop female genitalia and internal female reproductive organs. However, in both partial androgen insensitivity syndrome (PAIS) and complete androgen insensitivity syndrome (CAIS) the uterus is ...


12

The reasons why HIV is "incurable" (a misnomer) are legion: HIV is a retrovirus, which means it inserts its own genome into the host cell's genome. You must therefore kill each and every infected cell to rid the body of the virus. HIV is a lentivirus, which means it has a long incubation period, so it can "lay low" before symptoms are readily detected. ...


11

The combination of these two reports from the CDC give information about the comparative prevalence of flu infection in the winter (September '12- May '13) and summer (May '13 - September '13). I'm going to assume that 2012-2013 was a fairly representative year as far as the level of detail of "do we get sick more in the winter" goes. Particularly striking ...


11

For some background, it is essential to know that Ebola is actually a group (genus) of ebolaviruses, each with different fatality rates. There are five known species of Ebola, and four are known to cause disease humans (WHO: Ebola virus disease; wikipedia). The known species of Ebola includes: Zaire ebolavirus (or just ebolavirus) Sudan ebolavirus ...


11

Thank you for the fascinating question! It was tough to research but very worthwhile. LDL is actually not such a bad molecule. It is formed from VLDL/IDL after VLDL/IDL distribute triglycerides, phospholipids, cholesterol and cholesterol esters to peripheral cells. With less to give, LDL subsequently tries to be helpful by providing any needy peripheral ...


11

A cancer is not a pathogen A cancer is a group of cells that (because of several specific mutations) start to duplicate abnormally. This group of cancerous cells are the own cells of the sick patient. It is not another species infecting the individual carrying the disease. It is the individual itself who developed the disease. A cancer is not a pathogen (...


11

This is a great question. Just to make it clear people with DS do have a reduced risk of solid cancers and an increased risk of blood cancers, (B-ALL and AML). You are correct in picking out DSRC1 because of its angiogenic implications. The current hypothesis centers around people with DS being less capable of driving angiogenesis, and therefore having an ...


10

I'm not sure if I should be posting this as an answer, but I think a very approachable and accurate account of the history of HIV can be found from Dinis de Sousa et al.. I agree with what has been posted above. On the theory that a picture is worth a thousands words, you might also introduce skeptics to the cryo-electron microscopy images of the virus (...


10

I'm sure it varies wildly based on the animal and what they're eating. In general, if in the course of an animal's natural feeding process it picks up a little dirt, it has evolved to cope with that. Animal's behaviors and guts have evolved to fit their food source and lifestyle. For a behavioral example, seals will eat rough rocks to help breakdown bones ...


10

There is both a set "list" of agents, but more importantly, a set of properties that an organism needs to be in order to be truly worrisome. First, the list: The CDC classifies agents into one of three categories, Class A, B, or C. Class A: These are organisms that are hard to control, highly transmissible, and lethal: Anthrax (Bacillus anthracis) ...


10

The diversity of parasites shows a gradient with increasing diversity from the poles to the equator. Several reasons have been brought forth to explain the latitude-dependency of parasite diversity: An increased diversity overall around the equator; species diversity in general is greater in the rain forests and hence more hosts are available and thus more ...


9

In general antibiotics don't help with viruses. However, sometimes a bacterial infection may follow a cold virus, so there might be some scenarios in which antibiotics would be needed. However in many cases it could be due to people demanding antibiotics from their doctor. You can read more here (CDC site): http://www.cdc.gov/Features/getsmart/


9

Alzheimer's disease is a very complex field, and I am going to restrict my answer to two particular areas: the neuritic plaques and the neurofibrillary tangles. This area is also of interest to me, hence the protracted answer. The two pathological hallmarks of Alzheimer's disease, first described by Alois Alzheimer in about 1906, are the extracellular ...


9

There is the term “corset liver”. It describes changes (“grooves”) on the liver’s surface following external compression and subsequent local atrophy, e.g. from wearing a corset for a long time. (see Dancygier: Clinical Hepatology) A paper from the 1980s describes some abnormality in the histological findings of liver tissue of dogs after chronic abdominal ...


9

Disclaimer: I'm an infectious disease modeler, and generally pretty skeptical of "We modeled X like an outbreak!" claims, because many are just an exercise in curve fitting. Given that, the answer is both "Yes" and "No". "No": Murder as an act really isn't transmissible, and if its not transmissible, it can't be modeled as an infectious disease. "Yes": It ...


9

Yes, this is possible and is researched as an alternative to antibiotics. It has been used experimentally before antibiotics became widely available. Research was abandoned when antibiotics became widely available. See for example here and here for reports on this. Today bacteriophages are researched for the treatment of bacteria which have a lot of ...


8

This article has some good information. It's certainly more than I want to know about warts. Isolated warts may remain unaltered for months or years, or a large number of new lesions may develop rapidly in a short period of time. The development of warts is not predictable. Approximately 65% of warts disappear spontaneously within two years. ...


8

I have never heard about this phenomenon from my patients or professors at the Medical School, but this is a possible mechanism that comes to my mind. One of the classification for antibiotics takes consideration the effect on bacteria. Two possible effects are either stopping the proliferation (and letting the immune system to kill those that are currently ...


8

it does not, really. unless we're talking about things like frostbite or severe hypothermia. it's a myth that it does. the virus is more stable in colder air, however. see more here: Study Shows Why the Flu Likes Winter Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature Innate responses proved to be comparable between ...


8

Short answer Visual perception persists in the absence of functional eye movement. Background An example case would be retinal implants wearers. Retinal implants like the Argus II consist of a set of electrodes placed onto the degenerate retina of blind folks. Electrical stimulation of the electrode array elicits flashes of light (phosphenes). Visual input ...


8

Posted due to certain inaccuracies in comments and answers provided to this question regarding the Human Immunodeficiency Virus. It should be noted that while it may not affect the ability for macrophages in the dermis to phagocytose the heavy metals found in the inks used in tattooing, and thus not interfere with the fixing of a tattoo in an HIV+ person, ...



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