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- The virus © The virus the latter happens, the destroyed cells present as disease-ravaged Now we can take a look at the micro-organism about which the remnants of earlier life-forms. WHO and a number of other governmental and private At this point, we want to note that the virus which is involved institutions are generating all the hullabaloo: the virus...with with the disease complex called influenza has some close special attention to the bird species labelled HSN1. relatives worth mentioning. We'll let Lodish er al. say it for us: First, a definition: "virus n 1: the causative agent of an "Some animal viruses, including influenza virus, rabies virus, infectious disease; 2: any of a large group of submicroscopic and human immunodeficiency virus (HIV), have an outer infective agents that are regarded either as extremely simple phospholipid bilayer membrane, or envelope, surrounding the microorganisms or as extremely core of the virus particle composed of complex molecules, that typically viral proteins and genetic material." contain a protein coat surrounding an (Molecular Cell Biology, W.H. RNA or DNA core of genetic Freeman, New York, 2000, 4th edition, material but no semi-permeable . . p. 713) membrane, that are capable of growth The third and most important So, are influenza and HIV linked in and multiplication only in livin, i some mysterious way? Are we gettin, cells, and that cause various pathogen, albeit the most closer to the links between Dr Eoucte important diseases". (Webster's New neglected of the three, the flu specialist, and Dr Chanock, the Explorer Medical Dictionary, p. 747) i AIDS specialist? After all, they What does all this mean? Well, Is the My cop: lasma. worked together way back in 1964 take another look at the sketch of the acterium (figure 1). Notice the meandering line which represents the lueprint for reproduction and which - The Mycoplasma species is called deoxyribonucleic acid, the Let's continue with our search for the DNA. For the life of this particular species of bacterium, this is truth about influenza. The third and most important pathogen, an absolutely critical string of nucleic acids if the species is to albeit the most neglected of the three, is the Mycoplasma (see erpetuate its existence. figure 2 for an example). Now, suppose something were to kill the bacterium— Even though the WHO and other "health" agencies would have something such as a variant of penicillin which opens a rupture you believe that you should fear the avian flu virus, species in the bacterial wall. The draining of its cytoplasm will kill this HSNI, it is the mycoplasma that humanity has to fear. We ife-form, but there is still a will to live in parts of the DNA and remind you that the world of official medicine apparently doesn't RNA. Thus, particles of the DNA or RNA cluster together and want the average citizen even to know that such an organism quickly assemble a protein protective coat around themselves. exists. Here you have the essential virus: a particle of genetic Allow us to give you a thumbnail sketch of the mycoplasma. information with a protein coat. Start by taking a look at the Take a further look at the bacterium. Note that the bacterium bacterium and note the three has ribosomes which, as we have representative dots labelled seen, are involved in the manufacture ribosomes. In these organelles—and of RNA, and note further that although only three are shown in our sometimes particles of that RNA get sketch, the cytoplasm is full of loose due to bacterial death and are them—the nucleic acids called preserved by being gathered together ribonucleic acid (RNA) are into groups of eight RNA fragments assembled when it is necessary for which are then enclosed in a the bacterium to manufacture protective matrix and a_ cell proteins and enzymes for the membrane, and voila: there you have bacterium to function. As with the influenza virus! particles of the DNA, certain Now, take another look at the bacterial RNAs have the capacity to bacterium and notice the string of seek to survive when their original DNA. If the bacterium is killed, not life-form is threatened, by clustering only is there an attempt by the RNA together and self-assembling a to preserve its life as viruses, but when Mycoplasma pneumoniae was the centre of their interest. protein protective coat. Figure 2: Micrograph of a Mycoplasma arthriditis particles of the DNA will also seek to Somehow or other, the life-force cell at approx. 120,000 magnification _ continue as living organisms by which motivates the bacterium has (Courtesy of Dr Harold Clark, Chairman Emeritus, creating themselves a membrane and an inherent sense of which nucleic Common Cause Medical Research Foundation) setting off within their environment particles it needs to save when the original life-form is to find another host cell which will let them inside and give them threatened. Thus, the various species of virus are select particles arefuge. Again, voild: this cell-wall-less DNA particle becomes of genetic code which have sheltered themselves with a protein a self-replicating but somewhat incomplete life-form known as a coat until they can access another living cell and get on with the species of Mycoplasma! business of life. Thus, as microbiologist Dr Shmuel Razin describes it, the Unfortunately, in seeking to save their life particles, the viruses theme underlying the current evolutionary scheme of often have to destroy other life-forms such as human cells. When mycoplasmas is that of degenerative evolution from walled pathogen, albeit the most neglected of the three, is the Mycoplasma. Figure 2: Micrograph of a Mycoplasma arthriditis cell at approx. 120,000 magnification (Courtesy of Dr Harold Clark, Chairman Emeritus, Common Cause Medical Research Foundation) APRIL — MAY 2006 NEXUS = 31 The third and most important www.nexusmagazine.com