The Abicana webstore - Information about various types of viruses and how they infect
Back to main menu - hobby, health, fitness and training, automotive, skin care, fashion, atches electronics, music instruments
Go here to find natural products for specific problems in all areas of the body and for mental problems, incluing infections and allergies in the nose, throut and the lower respiratory system
Click here to see an exhibition of products for men and women to enhance potency and improve sexual satisfaction
Information about smart methods to combat diseases, gain stronger potency and sexual pleasure and get better condition, strength and body shape
Click here to find natural drugs to increase resistance against infections caused by viruses and other germs. Also to help you combat aging and restore youthful properties in your skin, circulatory system, muscles, joints, digestive system, senses, sexual functions, mood and mental allertness.
About Viruses (vira) - What is a Virus
A virus is a very small unit, much smaller than most bacteria. that can intrude into cells and command the cells to make new virus particles. At the end of this process, the cell is usually destroyed. Some vira, however, have mechanisms that permit the cell to store genetic material from the virus and make new viruses at a later period or perhaps at repeated periods.
A virus contain one ore more molecules with genetic information containing all infromation that is needed to replicate the virus. It contains a protein coat aeound the genetic molecule and it contains eventualy other molecules outside the protein coat that make it more easy to spread or intrude into cells.
How does a virus infect
When a virus infects, it will attach to structures at the outside of the cell. Then the virus is drawn into the cell with a cooperation between structures in the virus utself and structures at the cell membrane.
typically a virus have outsprings made of proteins or other substances that can attack to complementary substances at the surface of the host cells
Inside the cell, the virus will decompose itself so that the genetic molecules get free. By commandment from the virus, the cell will now make copies of the genetic molecules of the virus.
Then the cell will yhen make new virus protein molecules with the viral genetic information as templetes.
Then the new viral genetic molecules and the viral proteins will be assambled to new viruses. The vira is then released to the outside. Under this process some vira will take a part of the cell membrane of the host cell and use it as a membrane outside the protein molecules.
By the release of the vira the cell will most often be destroyed and it will often burst.
The genetic molecules of a virus can be of several types. It can be double stranded DNA. This is the same type of genetic molecules found in most animal cells. A virus having this type of genetic molecules can use the mechanisms in the host cells as they are to make new virus particles.
First the DNA-tread is replicated many times. This is done by spitting the double thread into two single thread, and new DNA-units is then connected together at the side of each single thread making a new thread that attaches to the original thread and thus two double threads are formed.
Then a RNA-threads are made with one of the DNA-thread as a template. These RNA-threads are then used as templates for building new protein molecules.
The information can be carried with single-straned DNA in the virus. In this case the DNA-thread of the virus must be copied so that there are two complementory threads.
One of the thread is used to make messengar-RNA and the messenger arena is used by the cell to make virus proteins.
The other thread is used by the cell to make new virus DNA.
Then the newly formed DNA and the protein are assambled to new virus units.
Single-stranded DNA-vira do not need many specific enzymes of their own to replicate themselves, but can mostly used the native mechanisms in the host cell. They have however to bring with along some tools necessary to initiate the replication process from a single thread, to handle the two DNA-strand as separate units and keep them as separate units.
The viral information can be carried by double-stranded RNA.
One of the strand are used to replicate the RNA itself. In this case the virus brings with it all enzyme molecules necessary to do the replication process of RNA, since the host cell does not have any mechanisms for replicating RNA, or the virus commands the host cells to make the enzymes first based on information in the RNA-molecule.
The other RNA-strand of the virus is then used as template for producing viral proteins. For this process the virus can use the native mechanisms of the host cells.
It is very common for vira to carry its genetic information by single stranded RNA.
In this case a complimantory copy of the RNA must be made so that there are two complimantory strands. One of the strands is used to make new RNA-threads to form new virus units.
For the RNA boubling and the further making of new RNA to be used in new virus particles, the virus brings with it the necessary enzymes, or it commands the host cell to make these enzymes based on genetic information in the RNA thread.
The other strand is used as template for forming virus proteins. If the original RNA-thread is the one used for protein production, the virus is said to have positive-stranded RNA. If the copy is the one used for protein production, then it is said to be a negative-stranded RNA virus. For the protein production the virus can use the mechanisms native in the host.
Single stranded RNA viruses are the most commonly occuring vira. most vira causing cold and influenza are of the single-stranded RNA type.
A retro-virus is a RNA-virus. After penetrating into the cell it makes a DNA-copy of the RNA by means of enzymes it carry with it or command the cell to make. Then the virus commands the cell to set this DNA-copy into its own genome. Thus the virus-originated DNA becomes a part of the cell itself.
On a certain triggering event, the cell will make virus-RNA with the DNA-copy as a template and the cell is commanded to make virus proteins as the RNA-threads as templates. Then new virus particles will be assambled from the RBA and protein.
Cells having such virus-originated DNA in their genome can live for a long time, until the DNA is activated. Then the process of replicating vira start and the newly formed vira can infact new cells.
Retro-vira causes many chronic diseases that break out with regular intervals, for example herpes.
AIDS is also caused by retro-virus.
RNA-viruses has more difficulties in getting the genetic information replicated than DNA-viruses, and the single-stranded variants have added difficulties. But RNA-viruses have a simplar way to get its protein manufactured, since the viral own RNA can be used as templates for building proteins. The single-stranded variants are also simpler to assamble and are smaller and can therefore spread more easily.
There are viruses that can attack all kinds of organisms: humans, animals of all kind, plants of all kind, microorganisms and even bacteria. Viruses that attack bacteria, so-called bacteriophages, do not intrude into the bacterium, since a bacterium is too small. Instead it injects its genetic molecules into the bacterium.
About common cold and flue - ( influenza )
THE SYMPTOMS OF COLDS AND FLU AND THE DIFFERNCES BETWEEN COLD AND FLUE
Common cold and flu (influenza) have much of the same symptoms. The symptoms come from the throut, nose and the rest of the body. The time between the virus has entered the body till the first symptoms arrive vary between 2-7 days. The symptoms often come very quickly, sometimes within a couple of hours.
The difference between cold and flue is these.
By common cold the symptoms are strong from the throut and nose, but the general symptoms and symptoms from the rest of the body are weak. Also the symptoms from the throut and nose tend to come first. Common cold tend to last a few days.
By flue the general symptoms are the strongest and the symptoms from the throut and nose are generally weaker. The general symptoms tend to come first. Flu also carry a higher risk of complications like additive bacterial infections. Flu tend to last longer than common cold - 7 - 14 days.
Symptoms seen by cold and flue are:
- Sore and tickling throut and nose.
- Swelling in the nose, throut and tonsils.
- Increased production of slime in the nouse and throut.
- The nose and throut are conjested due to swelling and slime, and often slime that dries and get hard.
- Fever and often high fever is common by flu but less common with cold.
- Generall feeling of being weak, especially by influenza
- Aching muscles
- Nausea and voimiting, especially by influenza.
A symptom sometimes seen by cold and flu is stiffness in the neck. This is also a symptom of meningitis that is a serious disease that needs immediate treatment. By meningitis the stiffness is usually more severe and other symptoms occur, like red spots on any part of the body. When stiffness in the neck occur, the situation must be checked often. If the stiffness is severe, the other symptoms occur or the condition gets worse, professional help must be called at once.
THE CAUSES AND MECHANISMS OF COLDS AND FLU
Colds are caused by over 20 types of viruses, and are highly contagious. Flu are caused by many virus types falling in three main cathegories - A, B and C.
The viruses causing flu, often mutate, producing steadily new strands. Flu often occur epidemic, especially when a new strand has appeared.
These types of virus are often transmitted by small drops from the respiratory tract or mouth of persons having the infection and born through air to another person. The nature of the viruses make them easily attack mucus membranes, and because the mucus membrans of the respiratory tract is that which the viruses most easily comes into contact with, the respiratory tract is the primary place for the attack.
The virus enters a cell in the mucus membranes. The virus carry with it genetic information that is released openly in the attacked cell. The virus also carry with it substances that command the cell to make duplicates of the genetic molecules introduced into the cell. Then the cell is commanded to make the virus proteins and to assamble new virus particles by composing the genetic molecules together witjh the virus proteins and other viral substances. When the cell is full of new virus units, it will die, burst and all the new viruses will be released to attack new cells.
The attack and damages will stimulate the immune system to act against the virus invation and will cause an inflammatory responce in the attacked tissue.
THE TREATMENT OF COLDS AND FLU
There exist vaccines against many types of cold and flu virus, but not against all. Vaccination is therefor not totally protective.
There is no traditional treatment directly against the viruses causing colds and flu.
Traditional treatment includes a regime with measures like: Drinking enough liquid, holding oneself warm and resting.
The pain by colds and flu is traditionally treated with acetyl salicylic acid - aspirin. Nowadays acetaminophen (Tylenol) is popular instead of aspirin.
Natural products to help against colds and flu have the aim of strengthening the immune system to decrease the incidence of these diseases, and help the disease to get away more quickly.
About influenza epidemics and pandemics
The viruses causing influenza mutate often, giving steadily new variants of the disease. The seriousness of the steadily new variants differ very much. Probably this is due to the extent of changes of the new vira from the allready existing variants. A very different variant will meet less immunological reistance in an individuel and in a whole population and is therefore more dangerous than a variant with only minor changes. Some variants will also be more virulent by means of their construction.
Influenza is also a disease in animals, for example birds and pigs. Sometimes a new variant originates by a mutation of a strain infecting an animal species and get properties that also makes it effective in infecting humans. New types of vira originating from those infecting animals seem to be more dangerous than those originating from human vira.
Swine or birds, especially domestic birds, are often the origine of a new virus variant. It mutate in the original species and then it is transfered to humans. It can also be trasfered to another species and mutate once more before it goes over to the human population.
Because of modern travel new variants of influenza viruses tend to be carried all around the globe in the extent of some months. Every year new epidemics occur this way. Often the epidemics are old strains of viruses that are carried around for just another round. Other times the epidemics are caused by new species of vira.
South East Asia seem to be the place where many of the new epidemics originate. They tend to reach North America and Europe each year in the end of winter or early spring. Epidemics that infect many people, are caused by especially dangerous vira or that are thought to be especially dangerous are often given their own popular name.
There is an extensive reaearch on vira, including human influenza vira in many laboratories around the world. There is therefore allways a danger that vira altered or downright invented in laboratories can escape or is even set out deliberatedly. It is difficult to assess how real that danger is and the reality of rumors of such things having happened. During the swine flu epidemy, an emplyee of a medical laboratoy claimed that that this virus had leaked out from the laboratory of his company by a mistake and that this was the origine of the epidemy.
The worlds health organizations steadily surveilles the occurances of new influenza outbreaks and by the time they reach Europe or North America vaxines have usually been produced. When the new strain originates from an animal species, the vaxine must be invented from ground to be effective and it then takes a longer time.
About the viruses causing colds
The viruses causing common cold are very variable. Ca 105 differnt types cause this disease. The genus Rhinovus cause ca 50 % of the common colds, the other 50& are caused by the coronaviruses, the human parainfluenza viruses and the human syncytial respiratory viruses.
RHIONOVIRUSES: The genus rhinovirus (Rhinoviridae) belongs to the virus family Picornoviridae, and it is the viruses most usually infecting humans. These viruses cause the common cold in ca 50% of the cases. There are 105 distingtive types of these viruses. These can be distinguished with chemical methods appied on human cerum containing the viruses.
The genetic material in the rhinoviruses is a single strand of RNA, about 7.9 kb in length. The RNA-srand mimic the human messanger RNA, that is the replica of the DNA that are carried from the cell kernel and there serve as a model for the proteine molecules to be built.
At the 5′ end of the genome there is a virus-specific protein, and like
mammalian mRNA, there is a 3′ poly-A tail. This tail causes the human
cells to recognize the viral RNA as something that shall be use as a model for
proteins to be built. Structural proteins are encoded in
the 5′ region of the genome and non structural at the end. This is the same for
all picornaviruses. The viral particles themselves consistof the RNA-chain and a
protein capsule (capsid) of icosahedral shape.
The capsid contains four viral proteins VP1, VP2, VP3 and VP4. The major part of the protein capsid consists of VP3. The much smaller VP4 protein lies as an interface between the outer capsid and the RNA genome. 60 copies of each of these proteins are assambled in the viral capsid and form an icosahedron. Antibodies are the most important defense against the infection. The structures that the antibodies recognize (epitopes) lie on the exterior regions of VP1-VP3.
Rhinoviruses are transmitted from person to person by small droplets of secretions sneezed or coughed out and born theough the air so that other persons breath them in.
They are also transmitted by secretions comming onto the
hands of the sick person and then are deposited onto surfaces that other persons
touch so that they get elements of the secretions stuck to their hands.
Thereafter the other person transmits the virus containing material to the mouth
by their hands.
Rhinoviruses occur worldwide causing disease especially in persons attending schools and other congregations. This enhances transmission during fall and winter. The frequency of colds is high in childhood and decreases during adulthood, most probably because of the possession of immunity.
DISEASES OF CORONAVIRUSES:
Coronaviruses primarily infect the upper respiratory and gastrointestinal tract
of mammals and birds. Four to five different currently known strains of
coronaviruses infect humans. The most publicized human coronavirus, SARS-CoV
which causes SARS, has a unique pathogenesis because it causes both upper and
lower respiratory tract infections and can also cause gastroenteritis.
Coronaviruses are believed to cause a significant percentage of all common colds
in human adults. Coronaviruses cause colds in humans primarily in the winter and
early spring seasons. The significance and economic impact of coronaviruses as
causative agents of the common cold are hard to assess because, unlike
rhinoviruses (another common cold virus), human coronaviruses are difficult to
grow in the laboratory.
Coronaviruses also cause a range of diseases in farm animals and domesticated pets, some of which can be serious and are a threat to the farming industry. Economically significant coronaviruses of farm animals include porcine coronavirus (transmissible gastroenteritis, TGE) and bovine coronavirus, which both result in diarrhea in young animals. Feline enteric coronavirus is a pathogen of minor clinical significance, but spontaneous mutation of this virus can result in feline infectious peritonitis (FIP), a disease associated with high mortality. There are two types of canine coronavirus (CCoV), one that causes mild gastrointestinal disease and one that has been found to cause respiratory disease. Mouse hepatitis virus (MHV) is a coronavirus that causes an epidemic murine illness with high mortality, especially among colonies of laboratory mice. Prior to the discovery of SARS-CoV, MHV had been the best-studied coronavirus both in vivo and in vitro as well as at the molecular level. Some strains of MHV cause a progressive demyelinating encephalitis in mice which has been used as a murine model for multiple sclerosis. Significant research efforts have been focused on elucidating the viral pathogenesis of these animal coronaviruses, especially by virologists interested in veterinary and zoonotic diseases.
HUMAN PARAINFLUENZA VIRUSES: These (HPIVs) are a group of four distinct serotypes of single-stranded RNA viruses belonging to the paramyxovirus family. They are the second most common cause of lower respiratory tract infection in younger children. Repeated infection throughout the life of the host is not uncommon. Symptoms of later breakouts include upper respiratory tract illness as in a cold and sore throat. The incubation period of all four serotypes is 1 to 7 days. Parainfluenza viruses can be detected via cell culture, immunofluorescent microscopy, and PCR. Though no vaccines currently exist, research into vaccines for HPIV-1, -2, and -3 is underway. Parainfluenza viruses last only a few hours in the environment and are inactivated by soap and water.
HUMAN RESPIRATORY SYNCYTIAL
VIRUSES (RSV): RSV is a
negative-sense, single-stranded RNA virus of the family Paramyxoviridae, which
includes common respiratory viruses such as those causing measles and mumps. RSV
is a member of the paramyxovirus subfamily Pneumovirinae.
RSV causes respiratory tract infections in patients of all ages. It is the major cause of lower respiratory tract infection during infancy and childhood. In temperate climates there is an annual epidemic during the winter months. In tropical climates, infection is most common during the rainy season. In the United States, 60% of infants are infected during their first RSV season, and nearly all children will have been infected with the virus by 2-3 years of age. Natural infection with RSV does not induce protective immunity, and thus people can be infected multiple times. Sometimes an infant can become symptomatically infected more than once even within a single RSV season. More recently, severe RSV infections have increasingly been found among elderly patients as well.
For most people, RSV produces only mild symptoms, often indistinguishable from common colds and minor illnesses. The Centers for Disease Control consider RSV to be the "most common cause of bronchiolitis and pneumonia among infants and children under 1 year of age." For some children, RSV can cause bronchiolitis, leading to severe respiratory illness requiring hospitalization and, rarely, causing death. This is more likely to occur in patients that are immunocompromised or infants born prematurely. Other RSV symptoms common among infants include listlessness, poor or diminished appetite, and a possible fever..
Recurrent wheezing and asthma are more common among individuals who suffered severe RSV infection during the first few months of life than among controls; whether RSV infection sets up a process that leads to recurrent wheezing or whether those already predisposed to asthma are more likely to become severely ill with RSV is a matter of considerable debate.
(This text is mostly based on materials from wikipedia.org, and it is therefore free to use for others)
About viruses causing influenza
The influenza virus is an RNA virus of the family Orthomyxoviridae, which comprises the influenzaviruses, Isavirus, and Thogotovirus. There are three types of influenza virus: Influenzavirus A, Influenzavirus B, or Influenzavirus C. Influenza A and C infect multiple species, while influenza B almost exclusively infects humans. The type A viruses are the most virulent human pathogens among the three influenza types and cause the most severe disease. The Influenza A virus can be subdivided into different serotypes based on the antibody response to these viruses. The serotypes that have been confirmed in humans, ordered by the number of known human pandemic deaths, are:
- H1N1 caused "Spanish Flu."
- H2N2 caused "Asian Flu."
- H3N2 caused "Hong Kong Flu."
- H5N1 is a pandemic threat in 2006–7 flu season.
- H7N7 has unusual zoonotic potential.
- H1N2 is endemic in humans and pigs.
- H9N2, H7N2, H7N3, H10N7.
Influenza B virus is almost exclusively a human pathogen and is less common than
influenza A. The only other animal known to be susceptible to influenza B
infection is the seal. This type of influenza mutates at a rate 2–3 times
lower than type A and consequently is less genetically diverse, with only
one influenza B serotype. As a result of this lack of antigenic diversity, a
degree of immunity to influenza B is usually acquired at an early age. However,
influenza B mutates enough that lasting immunity is not possible. This
reduced rate of antigenic change, combined with its limited host range (inhibiting
cross species antigenic shift), ensures that pandemics of influenza B do not
The influenza C virus infects humans and pigs, and can cause severe illness and local epidemics. However, influenza C is less common than the other types and usually seems to cause mild disease in children.
STRUCTURE AND PROPERTIES: The following applies for Influenza A viruses, although other strains are very similar in structure:
The influenza A virus particle or virion is 80–120 nm in diameter and usually roughly spherical, although filamentous forms can occur. Unusually for a virus, the influenza A genome is not a single piece of nucleic acid; instead, it contains eight pieces of segmented negative-sense RNA (13.5 kilobases total), which encode 11 proteins (HA, NA, NP, M1, M2, NS1, NEP, PA, PB1, PB1-F2, PB2). The best-characterised of these viral proteins are hemagglutinin and neuraminidase, two large glycoproteins found on the outside of the viral particles. Neuraminidase is an enzyme involved in the release of progeny virus from infected cells, by cleaving sugars that bind the mature viral particles. By contrast, hemagglutinin is a lectin that mediates binding of the virus to target cells and entry of the viral genome into the target cell. The hemagglutinin (HA or H) and neuraminidase (NA or N) proteins are targets for antiviral drugs. These proteins are also recognised by antibodies, i.e. they are antigens. The responses of antibodies to these proteins are used to classify the different serotypes of influenza A viruses, hence the H and N in H5N1.
INFECTION AND REPLICATION: Host cell invasion and replication by the influenza virus. The steps in this process are discussed in the text.Influenza viruses bind through hemagglutinin onto sialic acid sugars on the surfaces of epithelial cells; typically in the nose, throat and lungs of mammals and intestines of birds (Stage 1 in infection figure). The cell imports the virus by endocytosis. In the acidic endosome, part of the haemagglutinin protein fuses the viral envelope with the vacuole's membrane, releasing the viral RNA (vRNA) molecules, accessory proteins and RNA-dependent RNA transcriptase into the cytoplasm (Stage 2). These proteins and vRNA form a complex that is transported into the cell nucleus, where the RNA-dependent RNA transcriptase begins transcribing complementary positive-sense vRNA (Steps 3a and b). The vRNA is either exported into the cytoplasm and translated (step 4), or remains in the nucleus. Newly-synthesised viral proteins are either secreted through the Golgi apparatus onto the cell surface (in the case of neuraminidase and hemagglutinin, step 5b) or transported back into the nucleus to bind vRNA and form new viral genome particles (step 5a). Other viral proteins have multiple actions in the host cell, including degrading cellular mRNA and using the released nucleotides for vRNA synthesis and also inhibiting translation of host-cell mRNAs.
Negative-sense vRNAs that form the genomes of future viruses, RNA-dependent RNA transcriptase, and other viral proteins are assembled into a virion. Hemagglutinin and neuraminidase molecules cluster into a bulge in the cell membrane. The vRNA and viral core proteins leave the nucleus and enter this membrane protrusion (step 6). The mature virus buds off from the cell in a sphere of host phospholipid membrane, acquiring hemagglutinin and neuraminidase with this membrane coat (step 7). As before, the viruses adhere to the cell through hemagglutinin; the mature viruses detach once their neuraminidase has cleaved sialic acid residues from the host cell. After the release of new influenza virus, the host cell dies.
Because of the absence of RNA proofreading enzymes, the RNA-dependent RNA transcriptase makes a single nucleotide insertion error roughly every 10 thousand nucleotides, which is the approximate length of the influenza vRNA. Hence, nearly every newly-manufactured influenza virus is a mutant. The separation of the genome into eight separate segments of vRNA allows mixing or reassortment of vRNAs if more than one viral line has infected a single cell. The resulting rapid change in viral genetics produces antigenic shifts and allow the virus to infect new host species and quickly overcome protective immunity. This is important in the emergence of pandemics, as discussed in Epidemiology.
(This text is mostly based on materials from wikipedia.org, and it is therefore free to use for others)
These statements have not been evaluated by the Food and Drug Administration. This information is nutritional in nature and should not be construed as medical advice. This notice is required by the Federal Food, Drug and