Gajdusek joined the hospital where the patients were attended. He injected tissues from one youth man dead there into chimps: well, two years later one of them developed the disease! At this moment, the scientist called this as slow virus, and it showed him the transmission between species trough biologic material, therefore crossing barriers. Well, again it is a natural event, as it will be forever. In any case, he knew it was not a viral infection. Later, Igor Klatzo pointed the similarity of symptoms with the disease of Creutzfeldt-Jakob, formerly described by Hans-Gerhard Creutzfeldt and Alfons Maria Jakob in 1920.
Afterwards, an American veterinarian called William Hadlow knew in London an exposure of tissues coming from the kuru disease, and noticed the strong resemblance with the scrapie, that disease of sheep and goats, which provokes collapse, lip smacking, and compulsive scraping of the fleece against trees or fences. In this case, he already knew the disease was able to be transmitted as infection, but never thought it would not be possible it was a virus. Was Stanley Prusiner, American neurologist and biochemist who discovered later the prions, described as a kind of infectious self-reproducing pathogens, which could primarily or solely be composed of protein. Only a protein, is it true, and infectious? Yes, with nuances.
The story of prions, and the human and cattle diseases.
He was sure the called “prions” were lighter than virus, because these prions showed to be resistant to ultraviolet radiation and nucleases, so there were not nucleic acids. Even it is very resistant to heat, ionizing radiation and disinfectants that usually inactivates viruses. This agent does not affect to immune system, or inflammation, and is detected by the state of tissues affected. However, it can be inherited, transmitted or being appearing and hide out.
All this, after the outbreak on one variant of this group of diseases (the mad cow disease), nowadays we know the prion is the non pathogenic state (the PrPc) of a protein which accomplishes some functions in our brain (despite that we do not know too well it): in other words the prions have a job inside, related with acetylcholine, neuron development, metals management and others. The PrPc has expression in the liver, brain, muscle, heart, and pancreas. The primary structure of the protein is shared in all species, but it changes later: once one PrPc is modified erroneously or naturally (we call it then pathogenic PrpSc), the modified PrpSc is more resistant to digestion and starts to be accumulated as aggregates of amyloid plaques, becoming very strong and resistant. One prion PrpSc produces the conversion of other PrPc to PrpSc, and it continues increasing the number of this bunch killing the nearby neurons while grow. Prions enter in the body by being absorbed in the gut and are carried to the spleen, lymph nodes and brain. The triggers of the modification might be three amino acids (methionine, cysteine, and valine), or perhaps the substitution of proline by leucine.
Also, all the kinds of transmissible spongiform encephalopathy are related, as the mad cows disease, or the phenotype of the beer yeast, or in deer or mink. About its normal activity, it appears that the prions could be involved in formation processes of long-term memory, genome evolution, and immune memory. Currently some studies are aimed to elucidate the growth of amyloid plaques in Alzheimer disease, and the suspected relationship with the aluminum absorbed from alimentary packages, for example: these diseases may be tightly linked with Alzheimer's, Parkinson's, Huntington's, and Amyotrophic Lateral Sclerosis.
The disease may be transmitted through a blood transfer, but cannot be detected: then, with an incubation phase of 20 years, that takes up the attention about a possible epidemic and outbreak in a future. Thus, you can imagine how must be watched closely the alimentary chain, and its industry as only big source of troubles.
As conclusion, we can say that there are a gene PRNP (Prion-related Protein), which allows the production of a protein with a task in the body, and originated by a still unclear cause, it may be turned on in a modified form, which provokes the degeneration of some tissues. It may be transmitted hereditarily in some kinds, may be transmitted by ingestion of brain tissues or by contact, by transfusions or iatrogenic contact, and is capable of jump over species barriers in both directions. These proteins are shared with little differences by all species. In all the studies, has not been possible assert as sole and exclusive cause prions, leaving fully open the possibility of other agents that trigger the disorder, such as viruses or metals. In fact, nobody could figure out how a protein could replicate itself (at least that is what we believe to know currently). As in many other cases, it took many years the discovery of the proteinaceous origin for this disease, but still is unknown clearly the mechanism of activation. In this case, the disease affected also to cattle meat trade, what implied a serious investigation and research years ago. And all it may have some parallelisms and differences with other diseases, but always are the same basis there fully opened by definition to these kinds of events and phenomenon.
Now, it may be even more interesting to talk about the changes that we provoke into the animals.
Meat that is effective and productive.
Some time have you wondered why we do not improve the wild beings, also? You will reply quickly this is a full nonsense; we must let animals to be as they are, nobody could controvert it, and it is fully pointless... unless it can provide some profit. Then, we are at the same point as ever: profits. This word that you can find in third position by average when you search keywords throughout the scientific papers of economy, biology, genetics, pharmacy and more. Try it.
The same that was done with soils, was done with plants, was done with insects, and was done with animals, and so with livestock. But there are differences among kinds of livestock and its way of breeding, and its health, and thereby our health, and the health of soils and streams where livestock lives: again we are seeing another sort of chain more.
As it was made with forests, the establishment of rules to extract, ordering, valuing, assessing, and controlling forests with the only profitable aim along 200 years (thus was as born the forestry in the Western Europe), the same way has been for the livestock: principles of feeding by mixes of different forages, addition of minerals, control of diseases, metabolic supplements, "support" with growth hormones, "selection" feed "enhanced", control of the digestion efficiency, and many more things, some of them stupid, and why not, some of them smart decisions. The essential control of diseases as those that we have seen formerly, is a very clever goal, but as we have seen, it is only applied actually where some companies have a big amount of customers with fresh money. Then, where is the sense? The rest of technical improvements have only an economical goal: more meat, less costs, whatever the way.
Let me stop for a moment to ask a question: is not really efficient cattle stomach? We do not trust the balance that has won over millions of years of evolution? With a little common sense, not much more is needed to answer this question.
All of these techniques in management of livestock were done with one goal: have the bigger rate of production, with the lesser costs, in the shortest span possible, strictly the same goal than the applied in every manufacturing industry you can see. This goal, applied over the various millions of livestock farms that are there, and the many million heads of cattle and poultry that yearly are passing by the slaughterhouse, does not fits really to what we would think and like is better for us. Things really develop as only can happen, and anyway it also has consequences.
Much wild specie could be treated as cattle in the future, increasing the current trend with cattle and poultry, and use of techniques related (all photographs by the author).
Numerous organizations have made numerous studies with numerous specialists, repeatedly focusing many issues, consuming numerous resources: and they all follow the same trend as always, the same rule, are provided by the scientific consensus (rather than discussed this among themselves), with the global information, with the dictates of the five main stakeholders in the world: chemical, medical, industrial, food and finance teams. But with such global information
, the detail, the actual look, that which directly affects people, is really forgotten. We could ask this to most farmers medium-sized or small, they understand this very well and immediately.
If we go back and talk to old farmers in their eighties, which can recall their youth plowing the ground, and their barns and cattle fences, their replies will be the same always: they see many advances, many techniques, but only a few crops, many areas abandoned, and a complete dependence from suppliers which provide everything, from the wholesalers and a market that does not make sense. They cannot recognize any resemblance between their former products and what is being produced today: neither cattle, nor pigs, nor vegetables, nor fruits, nor crops, despite those greater productions that can be seen. This is logical.
It is not strange that the emerging diseases, or the unrecognized diseases, or the resistant-drugs infections can appear and be pointed in Europe and the United States mainly, where the meat trading, manufacturing, treatments, pollutants, the environmental conditions, the genetic selection, use of drugs, or prepared feed forages, are a mix of factors that have changed so