The Worm that isn’t a Worm at All: the Ringworm

When my daughter still attended elementary school, she came home one day with a note from the teacher that as parents we should be aware that cases of head lice had been noticed at school. All parents were therefore advised to check their children’s hair and if the insects or their nits attached to hair shafts were present to take steps to eradicate them. Unsurprisingly, we found that my daughter had also been infected, which led their two slightly older brothers to tease and avoid her, with one of them taunting her with “you are contaminated” (a word he must have learned recently). However, that very boy sometime later developed a ringworm infection on his scalp and then it was I, who avoided play fights with him and warned his siblings not to get too close to him or share his towel or pillow or cap. The term “ringworm” didn’t sound too nice and they all wanted to see what it looked like. But when I could not show them anything more than an oval or circular reddish and coin-sized patch on the skin of their brother’s neck, they were disappointed and lost interest.

So, what is this “ringworm” all about? Signs that a person is infected by the ringworm condition are the roundish patch mentioned above with a slightly raised edge and the fact that it itches badly. Doctors will diagnose this as something they call “tinea” or “dermatophytosis”; a complaint, in other words, caused by a skin fungus that in humans goes by the name Trichophyton schoenleini or T. rubrum in tropical regions. These species of fungi feed on the horny protein, known as keratin, which the outer layer of the skin, but also hair and fingernails consist of. These fungi belong to a fungal division known as Ascomycota (formerly termed Ascomycetes) , a grouping of species that also contains the important baker’s and brewer’s yeast Saccharomyces cerevisiae, the edible and expensive morels and truffels and some feared (and annoying) filamentous fungi inside the lungs.

Ringworm species that can colonize the human skin can be found in the form of dormant spores in the soil, but they may also reach human hosts from wild as well as domestic animals. Animals usually have their own species like Trichophytum verrucosum in the case of cattle or T. equinum in the case of horses and Microsporum canis in connection with dogs. The ringworm fungi cause these animals to feel itchy, but the fungi can also infect humans and humans can infect animals. What all these ringworm fungi have in common is that they love moist and warm skin and knowing that, one way to beat them is to dry the infected areas thoroughly after bathing or sweating. Of course it is also important to change clothes regularly like scarves, hats, socks, etc. that would have been in contact with the infected areas, and to avoid sharing combs and hair brushes with others and to change pillow covers and bed sheets frequently. Additionally, some anti-fungal creams and lotions should be applied to the infected areas. Certain lotions like oregano and lemongrass oils may help as well. If untreated the ringworm patches may develop into bald and permanently hairless areas.

There are, of course, other skin conditions that itch, produce reddish patches, lead to flaky skins and are irritating, but need not be caused by a ringworm fungus at all. Often going under the general name “eczema”, the autoimmune disease psoriasis is sometimes mistaken for ringworm. However, psoriasis is not contagious. It is caused by white blood cells known as T-cells that erroneously turn against the body and attack the skin when the latter has been injured by a chemical irritant, insect bite, sunburn, certain weather conditions or when a person has been under severe psychological or physical stress. In the case of my son (see above), his ringworm condition was a just punishment for having been mean to his sister when she suffered from head lice. But in terms of stress, it was mostly us parents who suffered during the time we had to worry about head lice and ringworms.

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

Silent Helpers to Treat Parkinson & Alzheimer Diseases:  Fish and Fruit Fly

One fascinating (and very useful) aspect of the nervous systems and its units, the neuronal cells (known as neurons), is that structurally and functionally there is virtually no significant difference between those operating in worms, insects, fish or humans. In fact throughout the animal kingdom the nervous system basically functions on identical principles. And that explains why research on diseases like Parkinson’s and Alzheimer’s can resort to using fish and fruit flies as models. As the global human population ages, we can expect to have more and more cases of people suffering from these diseases, which are classified as “neuro-degenerative ”. This means that they lead to a gradual loss of neuronal function, to the degeneration and ultimate death of nerve cells in the brain.

In Parkinson’s Disease the most visible symptom is the tremor and that was also the diagnostic feature when the English surgeon James Parkinson in 1817 described the disease as “shaking palsy”. It was the renamed “Parkinson’s Disease” by the Scottish physician William Sanders in 1865. It is known that the movement disturbances are caused by the loss of the neurotransmitter “dopamine”, a substance vital for signal transfer from one neuron to another via contacts between nerve cells known as “synapses”. For Alzheimer’s Disease, named after the German psychiatrist Alois Alzheimer, who published his observations in 1906, neuronal dysfunction is also characteristic, but here a build-up of toxic protein deposits known as amyloids cause the neurons to malfunction and slowly die, which then leads to cognitive problems like loss of memory, delusions, hallucinations, etc.

What the diseases have in common apart from being neurodegenerative is that there is certainly a genetic component, but that environmental triggers are also important. Especially in connection with Parkinson’s Disease a link to metabolic disorders like diabetes mellitus, cardiovascular problems, high blood pressure, a fat-rich diet, obesity, etc. have been established and a sufficient amount of insulin available to the brain to maintain essential glucose levels for meeting the brain’s energy requirements, has been identified to be critically important. Insulin resistance in the brain affects turnover processes of dopamine in the synapses and causes the characteristic movement disorders in sufferers of Parkinson’s Disease. But how can fruit flies help? Since fruit flies can be bred in large numbers, have short life spans, possess neurons that function like those in humans and exhibit motor behaviours like crawling, climbing, grooming, flying, etc. they can serve as models for the disease and its underlying genetics. One distinguishes between the familial Parkinson’s Disease and an expression of the disease that’s caused by environmental stimuli like toxic compounds. To identify  the underlying susceptible genes is one goal in which fruit flies help. After all they and humans share 61% of their genes including those that control the molecular mechanism of neurotransmitters. Paraquat (a pesticide) and rotenone (a poisonous plant substance) have been identified to disrupt the fruit flies’ metabolism in ways that resemble Parkinson’s Disease. There is, thus, hope that the fruit fly results can lead to treatments not just of the symptoms of the disease but the genetic causes as well.

Treating sufferers from Alzheimer’s Disease may one day benefit from research on the brain of the zebra fish, a small tropical aquarium fish that just like the fruit fly has become a “work horse” for genetic research of all sorts. In the past, the main approach to treat Alzheimer’s Disease was to try to prevent or slow down the degeneration of the affected neurons. But the research on the zebra fish has shown that there exist in this species’ brain some cells that can be induced to replace lost neurons. Hope is that such neurons in the human brain can be identified and induced to restore or replace neurons lost to Alzheimer’s. Progress often comes from unconventional approaches and as David Horrobin wrote “If a hypothesis which most people think is probably true does turn out to be true (or rather is not falsified by crucial and valid experimental tests) then little progress has been made. If a hypothesis which most think is improbable turns out to be true, then a scientific revolution occurs and progress is dramatic”. I love this comment on research!

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

“Hello!”

Greeting Correctly in the Human and Animal World is Important

Probably the most famous historical greeting is “Dr Livingstone, I presume!”  –  words that the New York Herald reporter Henry Morton Stanley spoke in 1871 when after a track of nearly eight months he found the Scottish missionary and physician Dr David Livingstone in a small village near Lake Tanganyika in East Africa. Not famous is the “greeting” by a Papua Niugini Highlander “You know I can kill you”, meted out to me when in 1972 I approached his dwelling and he pointed a bow and arrow at me. Greetings in humans are ubiquitous, often ritualized behaviours, designed to impress, reduce or suppress aggression. And they, of course, have roots in behaviours expressed by animals.

Take for instance the pressing of foreheads together or nose to nose contacts among Polynesians: isn’t that very similar to what you observe when two cats meet each other? Or why do the French “s’embrassent” on so many occasions and seek a cheek-to-cheek contact when they greet each other? Celebrating New Year’s Eve in France in 1983, I was to my displeasure even included in this hugging and kissing at midnight by party guests I did not even know and then had to politely remind them that I was a New Zealander, not accustomed to this kind of behaviour. It has been surmised that the hugging and kissing stems from an assessment of the opponents odour, when our noses were still more sensitive than now and that recognition by another individual’s smell. This  still plays a significant role for most mammalian species. However, it usually occurs when two individuals are very close to each other and because closeness can escalate and be dangerous, distant greeting signals have evolved to lessen the risk of a closer encounter. My grandfather used to tip or lift his hat to greet someone; we wave, nod our head, avoid direct eye contact, or behave like an old colleague of mine, who ever so briefly used to flick his head to one side (away from the other person) only to bring it back to its original position immediately thereafter. As with animals that can harm each other, briefly looking away or exposing a vulnerable body part are signs of trust, indicative of peaceful intentions and the crane’s famous dances with running around in circles, flapping its wings, may also be just mock flights. Waving and shaking hands, moreover, show that one isn’t concealing a weapon and the touching of antennae in ants when they meet also precludes the simultaneous use of their biting mouthparts, allowing individuals to smell and assess each other and perhaps to exchange food.

Touching sensitive body parts would be the ultimate of expressing trust and I was somewhat amused in 1972 to see adult Onabasulu men in the Southern Highlands of Papua Niugini (even photographed them) touching each other’s genitals. A similar behavior had earlier been reported from Central Australian Aborigines and in the animal world it finds its equivalent amongst the baboons for whom genital fondling is a well researched ritual amongst adult males. Vocalizations often precede more physical greeting rituals and while we may shout “How are ya” or say “Hello” or “G’day”, animals may announce their presence and intentions by songs, grunts, stamping of their feet, etc. Bill clapping in storks can serve as a warning and be a greeting. In fact, many signals used in greetings can also be part of warning rituals, depending on their intensity, context and (if vocalizations are involved) pitch as well. You can, after all, often distinguish the ‘happy’ from an aggressive dog’s bark.

My aquarium fish don’t bark, but when I introduce a new swordtail male, old and new individuals line up in opposite directions and wriggle, a “greeting” that usually escalates and turns into a fight. When two dogs meet for the first time, they also often stand side by side in opposite directions as part of their greeting ritual and begin to explore each other’s backsides with their noses. My grandfather used to say jokingly that they wanted to identify the culprit that had stolen and eaten the roast at the dogs’ great convention and that they were still searching for the ‘felon’. Well, a dog’s anal region is a treasure of information (if you’ve got a nose with 150 million receptors in it) and mood, gender, age, state of health and much more, including  the dog’s last meal, can be sniffed out in the cocktail of odours that is emitted from the anus and its associated glands in the rectum.

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.