“Biofilms” were all the rage in academia in the 1990s, and in today’s world of genetic and molecular engineering continue to be hot hype. I’m proud to say that a regular reader of this column—Frank J, lifelong resident of northern New Jersey and peerless entrepreneurial engineer—pioneered biofilm research in his undergraduate years in quaint and/or historic Piscataway, New Jersey.
The general importance of biofilms—thin membranes stretched over environmental surfaces, owned and operated by bacteria but encompassing a large measure of extracellular material (mucilaginous proteins, free enzymes, other structural molecules), bound up with an ecosystem’s worth of protozoans, algae, nematodes, tardigrades, yeasts, fungi, and other biological flotsam and jetsam—shouldn’t have been a surprise. It is really only a scalar difference between biofilms and the key structural manifestation of macroscopic ecosystems, edges or ecotones. Edges have ecological significance way out of proportion to their spatial extant. This is because edges are loci of activity at the interface of different ecosystem types, encompassing the goings-on of each of the adjacent systems while operating as a third, emergent system of its own distinction.
Think of a common ecotone. Something you pass by every day on your evening jog or morning walk. For example, the sharp structural interface of a meadow and a woodlot. The edge filters the movement of organisms—meadow or forest specialists do not pass the edge, functioning most efficiently in their “pure” habitat. Some animals—deer, rabbits, woodchucks, foxes, many birds—exploit the linear nature of the edge as a primary pathway for movement and foraging. Many animals and plants are evolutionarily specialized for existence in ecotones, jacking up the biodiversity. Productivity is high in the ecotone relative to the adjacent habitat types—there is more sunlight than under the forest canopy, and the nutrient-rich, high-carbon litter and soil horizons (themselves another form of ecotone) of the forest spill out into the more austere soils of the meadow.
With scale in mind, other biofilms are of enormous physiological importance. Your skin, for example. A rich ecosystem, fueled by epidermal cells and their extracellular exudates, a mosaic of dry, waxy, oily, and keratinaceous substrates inhabited by a shocking number and diversity of bacteria, protozoa, nematodes, mites and other biological hangers-on.
And your mucous membranes. The critical interface between organs and spaces (“lumina”), think throat, windpipe, sinuses, stomach, intestines, lungs, pericardium. And, in some cancer patients (me, for example), the turf over which the long-term wars for comfort, quality of life, and even survival are being fought.
At the moment, my residual health contretemps have to do primarily with mucous membranes. Two rounds of radiation and chemotherapy, and a series of surgical interventions have left my sinuses, oral cavity, and throat in a shambles. From a functional perspective, the most crippling outcome is the destruction of my epiglottis. If you will remember back to high school or introductory college biology, the epiglottis is an odd little structure. It serves as a valve, moving to cut access to the gastrointestinal tract (GIT) when you breathe, and reciprocally, to cut off your airway when you swallow.
These are important functions. Foreign solids or liquids sliding down the trachea, through the bronchi, and into the lungs are bad things. The outcome of gunk reaching the lungs is a form of pneumonia. That tater tot you inhaled, for example, will inflame the air-exchange surfaces of the lung and trigger an evolutionarily intricate, but none-too-effective, physiological response. The lung tissues produce enormous volumes of mucous (a mostly-protein goop) in an attempt to keep the blob of shredded potato mobile. Cilia lining the airway in great waving meadows try to crowd-surf the bolus of golden brown and delicious convenience food back up the bronchi, into the airway, and, with an assist from the epiglottis, dump it into the opening of the throat so it can be handled properly by the GIT.
My epiglottis happened to be directly in the line-of-fire of the radiation beams. It fried, becoming completely dysfunctional. It’s still present, and it makes a valiant effort to do its job, but all it can muster is to flap impotently and irritate adjoining tissues. So now, stuff in my mouth slides down the void where my tongue used to be and splits about 50 : 50, half running into my gut, and half into my lungs. When the dietician did a swallowing study, she found that blob of ice cream put into my mouth perched on the twisted wreckage of my epiglottis, then split, half to lungs, half to gut. The half teaspoonful of goop wreaked havoc. I spent several days with pneumonia-like symptoms before the hard-working cilia could crowd-surf the goop back up and out.
After excising the cancerous tissues from my mouth and throat, the surgeons reconstructed a baroque sort of ad hoc infrastructure intended to provide me with at least a modicum of functionality. The basic idea was paste up an engineered functional equivalent of the moving parts they hacked out. In earlier posts, we talked about the failed attempt to sculpt a quasi tongue from a slab of muscle harvested from my left thigh. While they couldn’t save my poor epiglottis, they needed to provide some separation so that stuff originating in my mouth wouldn’t pour en masse into my lungs.
I’m unclear about the present physical structure of my mouth and throat, despite the best attempts by Drs. H and N (the latter being the reconstruction expert) to explain it to me. But I do know that there is a slab of epidermis from my left arm, complete with its hairs, exposed in my oral cavity, supported by a hunk of muscle tissue from my torso. And that the salivary and mucous glands in my oral cavity and upper throat region were of necessity damaged by the surgery.
Presently my body is doing its best to work with the aftermath of the surgical battles. Salivary glands in my oral cavity came back online some weeks ago, and they are producing great quantities of thin saliva. Mucous glands deeper in the throat recovered sufficiently to pump out a thick and sticky goo rather akin to mucilage glue (for those of you born after say, 1975, mucilage glue was a syrup made of animal proteins originating in massive industrial retorts where carcasses of farm animals, slaughterhouse leftovers, veterinary flotsam, road kills and other sources of animal bodies were boiled under pressure. The (no doubt horrifying) residue was further treated to yield a glue used in schools, offices, homes...anyplace where items had to be stuck together. It has since been largely replaced by more sophisticated (and less disgusting) materials). From conversations with Dr. H, I gather that the hairy patch of arm skin in my throat is attempting to bootstrap itself, rather clumsily, into a functional mucous membrane. An artifact of that conversion process is the production of yet more thick sticky mucous.
Anyway. I spend a lot of time working to keep my throat clear of all this gunk. I go through rolls of paper towels at the rate of 2 or 3 per day. I have discovered that heat—very warm air in the room, and packing a heating pad against my chest—facilitates my efforts to keep from drowning in my own slime. I take rather heavy doses of over the counter products designed to constrain mucous production. One of the weirdly unexpected benefits of opiates (or at least dilaudid, which is what I have) is that they contribute to drying things out (the doctors are befuddled when I explain this to them. Apparently nobody has ever reported this effect before). I have a medical vacuum pump system intended to assist me in keeping my airway clear. I’ve never had to use it. I find that a strong cough generally does the job. I gather that in this, I am unusual. The doctors say that people in my condition are generally dependent on the vacuum punk. I guess I’m just lucky.
Mucous management is now an important part of my day. It is as disgusting as it sounds. But. It’s mucous management. It’s not, as it could easily have been, managing more dire problems. This I can do.
And this I can live with. Wounded and dysfunctional as I am, I am learning to deal with my “new normal” physiology. And with not being able to talk. And with the intricacies and logistical difficulties of having a hole punched in my throat and body producing slime at a rate that would make me a credible competitor in a slime-off with a hagfish. I am far from strong and functional. But I’m alive. I’m recovered enough to enjoy cooking again (for others, obviously. I need to have lots of tasters around if I’m working on anything complicated). I don’t know how much I’ll be able to do—I remain weak and nauseous. But I know I’m really happy to be here to find out!
My love to you all. I hope you all had fabulous winter holidays, and are looking forward to a great year as 2014 (can you believe it?) plays out. I certainly know I did, and I am.
Talk to you next week. Thanks, everybody!
Dave, have a great 2014--love your attitude, and your blog snot bad!
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