New answers tagged

0

Like other forms of amyloid, aggregated prions form a beta-sheet structure, where individual beta-strands are linked together by hydrogen bonds between their extended peoptide backbones, and hydrophobic interactions between the side chains on either side of the peptide backbone. The beta-strand at each end of the beta-sheet has unpaired hydrogen bonds and ...


0

It is thought that infectious prions exist as clusters forming a crystalline structure. When a protein with the same primary structure is encountered but with a different tertiary structure, the normal protein undergoes a conformational change in order to integrate into the cluster. Presumably there are molecular forces involved that induce the ...


-1

The reduced iron availability affects the red cell size during differentiation. The presence of red cells with reduced mean corpuscular volume (MCV) reflects reduced hemoglobin synthesis, which can have several causes. It can result from defects either in iron acquisition or availability, or in heme or globin synthesis. Experimental data in mouse ...


1

The main reason is that there really isn't any one "cold," but rather the word is used to describe many different infections that simply have the same symptoms. The reason for these same symptoms is that almost all of the symptoms that one experiences in a cold are actually the immune response to said infection. For instance, a fever is used to make the body ...


2

Firstly, as Remi.b points out, although Trypanosoma brucei infection is invariably fatal in humans, the same is not true for all host species. Domestic animals, particularly cattle, are an important reservoir of T. brucei rhodesiense and can also be infected with T. brucei gambiense (although it's not clear how important a reservoir they are for gambiense). ...


2

What you're talking about is called mechanical transmission (at least in veterinary and medical circles; plant epidemiologists call it something different). There's a nice overview by Gray and Banerjee here, although it's a bit old. The short answer is that blood-feeding insects can mechanically transmit a range of pathogens, including viruses. Mosquitoes ...


1

Nonclinical depression is a popular term for the natural reactions to the external factors, such as loss, seasonal changes, emotional stress http://www.depressionfree.com/non-clinical.html while the major types of clinical depression are as follows: Major Depressive Disorder Major depression is a severe mental disorder that deeply affects an individual’s ...


2

The article is hypothetical. It's written as a discourse trying to explain why pets are sick less than their owners, while the foundation of that hypothesis is not founded: see section 4 of your linked paper: A hypothesis put forth in this discourse is that humans get sick more often than animals and, correspondingly, typically engage in medical ...


4

Yes, this is possible. The probability has been estimated by Princeton at 1 in 10 million (per bite). It is not against the laws of Physics that blood cells can remain for some time on the proboscis or other mouth-parts of a mosquito. Whether this is probable is a matter of interpretation depending on your definition of 'probable'. But your question is about ...


0

Trypanosoma, the parasitic protozoans that uses the TseTse fly as vector to reach its definitive host, a mammal. In wild mammals, Trypanosoma brucei has no noticeable impact (Chatterjee, 2009). I don't know about Trypanosoma cruzi. Parasite who recently transferred from one host to another are often the most virulent. In the particular case of a parasite ...


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 ...


75

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 ...



Top 50 recent answers are included