The Loomis Lichen Cancer Hypothesis as specifically applied to, relating to, or denoting the thin tissue forming the outer layer of a body’s surface and lining the alimentary canal and other hollow structures on and in the human body.
An Overview of the Genus Prototheca: Intricate Characteristics and Interactions with the Human Body as a Foundation for What We Currently Call Cancer.
Lichen Diversity. There is no global list of known lichen species, but estimates vary from 13,000 to 30,000 different species. The various growth forms are described as crustose, foliose, and fruticose.
A lichen is not a single organism, but the result of a partnership (mutualistic symbiosis) between a fungus and an alga and/or cyanobacteria. A multi-partner (multicellular, multispecies) organism. Some lichens are formed of three or more partners, as mentioned. The body of a lichen consists of fungal filaments (hyphae) surrounding cells of algae(prototheca) and/or cyanobacteria.
Prototheca is a unique genus of algae that falls under the family Chlorellaceae. Unlike other algae, Prototheca species are distinct in their ability to inhabit and interact with the human body, exhibiting an intriguing blend of symbiosis and pathogenicity.
At the most fundamental level, Prototheca are achlorophyllous, meaning they lack chlorophyll and hence are incapable of photosynthesis, a trait atypical for algae. They are eukaryotic organisms characterized by their unicellular nature, distinct cell walls, and the presence of multiple organelles. Furthermore, their life cycle features both sexual and asexual stages, contributing to the robust adaptability and resilience of these organisms.
Among the different species of Prototheca, P. wickerhamii and P. zopfii are the most significant in terms of human interaction. Notably, these organisms demonstrate an unusual ability to inhabit various human body environments, both on the skin and within the internal biological system. They survive within a wide range of pH levels, temperatures, and osmotic pressures, and hence can proliferate in diverse habitats.
While some Prototheca species live harmoniously with their host, others exhibit a pathogenic relationship. Protothecosis, a rare infection caused by Prototheca, primarily affects immunocompromised individuals and may manifest as cutaneous, systemic, or disseminated diseases. Cutaneous protothecosis usually results in lesions and ulcers on the skin surface, while systemic or disseminated protothecosis can affect multiple organs, including the eyes, lymph nodes, and central nervous system.
The fact that Prototheca lacks photosynthetic machinery but retains other typical algal characteristics presents a fascinating evolutionary question. It’s hypothesized that they evolved from photosynthetic ancestors and adapted to a saprophytic lifestyle, utilizing organic material from the surrounding environment for survival. This adaptation may have paved the way for Prototheca’s transition from an external environment to a human host.
Moreover, these algae have developed resistance mechanisms against certain antifungal medications, which complicate their treatment when they cause infections. This suggests a high adaptive capacity and the potential to pose a greater threat to human health in the future if not properly understood and managed.
The genus Prototheca offers a compelling example of how microorganisms can evolve and adapt to novel environments. Despite their rare occurrence, Prototheca species’ ability to thrive in and on the human body underscores their significance in medical microbiology.
Further, prototheca is a genus of algae that, although rare, can cause disease in both humans and animals. Most notably, they cause protothecosis, a rare infection which can range from a localized skin condition to a serious systemic disease depending on the species and the health condition of the individual. Prototheca wickerhamii and Prototheca zopfii are the species most commonly involved in human infections.
1. Prototheca wickerhamii: This species is most often implicated in human disease, causing both localized and systemic forms of protothecosis. In localized infection, the algae typically causes cutaneous lesions, most commonly in the form of nodules, ulcers, or plaques. It is especially prevalent in immunocompromised individuals, such as those with HIV/AIDS, transplant recipients, or those undergoing chemotherapy. If the infection becomes systemic, it can spread to various body organs, including the lymph nodes, eyes, and central nervous system, leading to severe health complications.
2. Prototheca zopfii: While this species is more commonly associated with bovine mastitis (an infection of the udder in dairy cows), it can also cause human disease. Similar to P. wickerhamii, P. zopfii can cause skin lesions in humans, and more rarely, systemic infections. In systemic infections, P. zopfii can affect multiple body systems, leading to symptoms such as weight loss, fever, and fatigue. It can also lead to conditions such as arthritis and olecranon bursitis.
The impact on human health can be quite severe, particularly in immunocompromised individuals, who are more susceptible to systemic infection. It is also important to note that Prototheca species resist most antifungal drugs, making treatment challenging.
Preventing protothecosis involves general infection prevention measures, such as good personal hygiene, using protective clothing and gloves when necessary, and ensuring those with compromised immune systems are especially careful to avoid potential sources of infection.
Their unique features, interaction with the human host, and the diseases they cause warrant comprehensive research and a better understanding of these intriguing organisms.
Algae produce a variety of harmful compounds. These compounds can be toxic to organic life. Here are some examples:
- Microcystins: These are potent liver toxins contributing to carcinogenesis.
- Anatoxins: These are neurotoxins that can cause paralysis and respiratory failure.
- Cylindrospermopsins: These toxins affect the liver and kidney, potentially leading to carcinogenesis.
- Cyanotoxins: These are a group of toxins produced by cyanobacteria, a type of algae. They include several subclasses. See below.
Cyanobacteria can produce a range of toxic compounds, collectively referred to as cyanotoxins. They pose significant risks to humans, animals, and the environment. These toxins can be broadly categorized into four groups based on the physiological effects they cause:
1. Hepatotoxins: These primarily target the liver and other internal organs. Microcystins and nodularins are common examples of hepatotoxins produced by cyanobacteria. They inhibit protein phosphatases, leading to liver damage and possibly death in severe cases.
2. Neurotoxins: These toxins primarily affect the nervous system. Anatoxin-a, also known as “Very Fast Death Factor,” and saxitoxin, which is a potent paralytic agent, are examples of neurotoxins produced by cyanobacteria. These toxins can cause symptoms ranging from muscle twitching to respiratory paralysis and death.
3. Cytotoxins: Cylindrospermopsin is an example of a cytotoxin, which primarily targets the liver but can also affect the kidneys, heart, and other organs. It inhibits protein synthesis and can cause cell death.
4. Dermatotoxins: These toxins can cause skin irritation, such as rash, swelling, and blistering. Lipopolysaccharides found in cyanobacteria are suspected to cause these effects.
It’s important to note that not all cyanobacteria produce toxins, and those that do may not produce them under all conditions. The production of toxins can be influenced by environmental factors such as light, temperature, and nutrient availability.
Algae, like all photosynthetic organisms, require several key nutrients for growth and survival. The main nutrients required by algae include:
1. Light: As photosynthetic organisms, algae require light energy to convert carbon dioxide and water into sugars (glucose) and oxygen through the process of photosynthesis.
2. Carbon: Algae utilize carbon dioxide (CO2) from their environment to create organic compounds for growth and reproduction. This is done through the process of photosynthesis.
3. Nitrogen: This is an essential element for protein synthesis and is required for growth and reproduction in algae. Sources of nitrogen for algae can include nitrate (NO3-), ammonia (NH4+), or dissolved organic nitrogen.
4. Phosphorus: Phosphorus is a key component of ATP, nucleic acids (DNA and RNA), and other molecules necessary for energy transfer and genetic information storage. Algae typically absorb phosphorus in the form of phosphate ions (PO4^3-).
5. Potassium: Required for enzyme activity and maintaining the ionic balance within algal cells.
6. Sulfur: Sulfur is a component of some amino acids and vitamins, and is essential for protein synthesis.
7. Trace elements: Algae also require trace amounts of various other elements, such as iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), molybdenum (Mo), cobalt (Co), and several others. These elements are involved in various biochemical processes, such as serving as cofactors for enzymes.
8. Vitamins: Some algae species may require certain vitamins for growth, such as B12, B1, and biotin.
It’s important to note that the specific nutritional needs can vary somewhat depending on the species of algae. Some can fix nitrogen, including prototheca(human algae) from the atmosphere, while others require it from their environment.
Characteristics and Forms of Lichen Presented on and in the Human Body
Lichens are fascinating composite organisms, primarily comprising a symbiotic association of two distinct species: a fungus (mycobiont) and a photosynthetic partner (photobiont), usually an algae or cyanobacteria. Traditionally, lichens have been recognized for their ability to colonize some of the harshest environments on Earth, from desolate Antarctic tundras to bare rocky terrains. Less known, however, is the existence and characteristics of lichens that have adapted to survive in and on the unique ecosystem of the human body.
One should distinguish the lichen-forming fungi from the medically recognized condition called “lichen” in humans, such as lichen planus, lichen planopilaris or lichen sclerosus, which are not associated with the symbiotic organisms found in natural environments but are dermatological conditions characterized by skin lesions. The use of “lichen” in these instances refers to the similarity in appearance to lichen in nature. This essay will focus on the characteristics of true lichen in and on the human body.
The human body represents a distinct and specialized habitat for lichen species due to the specific microclimate, availability of nutrients, and constant interaction with the human immune system. Here, lichens have not only adapted to survive but have also diversified into numerous forms, exhibiting various morphologies and reproductive strategies.
Of their morphologies, lichen on the human body can be divided into three main types. The first is the crustose form, which grows flush against the skin. This form is characterized by its encrusting thallus, or body, that adheres tightly to the substrate, making it almost inseparable from the human skin. The second type is the foliose form, which resembles leaf-like structures. They are somewhat flat, and unlike crustose lichens, they can be gently removed from the skin. Lastly, the fruticose form resembles miniature shrubs, displaying a branched or bushy structure. Fruticose lichens are relatively rare in the human ecosystem, likely due to the environment’s constant change and relative instability.
Reproductive strategies of lichens in and on the human body are primarily asexual, involving the production of specialized propagules like soredia and isidia. Soredia are tiny balls of algal cells surrounded by fungal hyphae, which can be dispersed by minor disturbances and form new lichens elsewhere in or on the body. Isidia are cylindrical outgrowths that can break off to initiate new colonies.
Living in and on the human body also poses unique challenges to lichens, including elevated temperatures, varying humidity, constant shedding of skin cells, and the dynamic host microbiome. Think dry sauna. Lichens have adapted to these conditions by developing specialized structures and biochemical compounds. Many lichens produce unique metabolites, collectively termed as lichen substances, which have antibacterial and antifungal properties, helping them to fend off potential competitors and to resist the host’s immune responses.
While the study of human-associated lichens is still in nascent stages, early evidence suggests a complex interaction with the host. They can potentially influence the skin’s microbiota and even participate in nutrient cycles, such as nitrogen fixation.
In conclusion, lichens that reside on the human body showcase a complex array of adaptations to a unique habitat. Understanding their roles, interactions, and implications on human health remains an intriguing area of research, with potential applications in dermatology, microbiology, and pharmaceuticals.
-Michael J. Loomis & ChatGPT