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Ascariasis Warning Signs: What To Look Out For

© Provided by Getty Images Ascariasis

Overview

A disease characterized by infestation with a roundworm species called ascaris lumbricoides. Can infect either intestine or lungs.

Symptoms

If you're experiencing new, severe, or persistent symptoms, contact a health care provider.

Ascariasis symptoms depend on the organ affected.

If the lungs are infected, one may experience:

Cough

Difficulty in breathing

Wheezing

Chest pain

If the intestine is affected, the patient may experience:

Abdominal pain

Abdominal distention

Nausea and vomiting

Diarrhea

Heavy infestation can cause intestinal obstruction and constipation

Worms might be spotted in the vomit or stool

Malnutrition

Weight loss

→ Common treatment options

→ How is this diagnosed?

Causes

Caused by the infestation of a parasitic roundworm called Ascaris. It occurs when the eggs of ascaris lumbricoides are ingested through contaminated food. Children can get infected when they put their hand in mouth after playing in the contaminated soil.

Risk factors include

Age children above 10 years or older and who are likely to play in dirt in a contaminated area

Warm climate countries with warm temperatures are congenial for the parasites to survive.

Poor sanitation more common in developing countries with poor or open sanitation.

Beaches contaminated soil in unhygienic beaches

→ Questions to ask your doctor

→ Interested to know more? Check out the full article here

Give Roundworms Some Weed And They'll Get The Munchies, Study Finds

Enlarge / Image of worm that is genetically engineered so that certain neurons and muscles are fluorescent. Green dots are neurons that respond to cannabinoids. Magenta dots are other neurons. Stacy Levichev reader comments 36 with

There is historical evidence that people knew as far back as 300 BCE about the ability of cannabis—which includes several different plants, such as sativa, indica, and ruderalis—to stimulate the appetite. The technical term is "hedonic amplification of feeding," but most of us know it more colloquially as "the munchies." Numerous scientific studies have found evidence in support of this effect. And now it seems like the humble roundworm, C. Elegans, also experiences the munchies when dosed with cannabinoids, according to a new paper published in the journal Current Biology. We suspect it's not a coincidence that the paper was released on April 20.

The worms in the experiments showed a marked preference for the roundworm equivalent of potato chips or ice cream—high-calorie junk food. "We suggest that this increase in existing preference is analogous to eating more of the foods you would crave anyway," said co-author Shawn Lockery, a neuroscientist at the University of Oregon in Eugene. "It's like choosing pizza versus oatmeal."

The endocannabinoid system (ECS) regulates and controls several critical bodily functions: learning and memory, sleep, temperature control, pain control, alertness, and appetite, for instance. It's basically a network of chemical signals and receptors running all through the brain and body. One of the most numerous receptors in the brain is called CB1, which helps control the levels and activity of neurotransmitters. The body naturally produces molecules called endocannabinoids to stimulate those CB1 receptors. There are also CB2 receptors that are mostly concentrated in the immune tissues that help keep the immune system functioning properly.

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Cannabis plants have substances that bind to those same receptors, notably marijuana's active ingredient, tetrahydrocannabinol (THC), which stimulates appetite by binding to CB1 receptors and mimicking the activity of the body's naturally produced cannabinoids. For instance, a 2014 study with mice showed that THC significantly enhanced their ability to smell. A 2015 study identified a specific cluster of nerve cells in the hypothalamus region of the brain called pro-opiomelanocortin (POMC) neurons that were affected by cannabis. These neurons typically regulate appetite by sending "full" signals to the brain after eating, but cannabis hijacks the cells, flipping a switch so they send "hungry" signals instead.

CB1 and CB2 receptors are uniquely found in vertebrates, but most animals have receptors that could be sensitive to cannabis—after all, organisms, in general, need to regulate energy balance to survive. But there haven't been many studies of the endocannabinoid system in animals other than rodents and primates, especially invertebrates.

Enlarge / A population of C. Elegans with an author's eyelash for scale. Shawn Lockery

Enter Lockery and his co-authors. Lockery's lab has long focused on studying the neurobiology of C. Elegans, particularly how these tiny creatures smaller than a human eyelash make decisions. The roundworms are relatively simple creatures; their genetics is well-known (and genome fully sequenced), they reproduce rapidly, and they are easily screened for any effects of potential drugs. Plus, its small but well-defined nervous system—including a functional endocannabinoid signaling system—makes C. Elegans ideal for neuroscientists, like Lockery, interested in the effect of sensory inputs on motor outputs and overall behavior of the organism.

Lockery's lab often uses food choice experiments in their research. Roundworms rely on chemotaxis to find food, using taste and smell cues. He got the idea for testing the worms' response to cannabinoids soon after the state of Oregon legalized recreational marijuana in 2014 (with the new law taking effect in July 2015). "We thought, well, heck, let's just try this," said Lockery. "We thought it would be amusing if it worked."

First, Lockery et al. Soaked roundworms in an endocannabinoid molecule called anandamide, known to activate cannabinoid receptors. Then they put the worms in a T-shaped maze. On the left of the horizontal top of the T, there was highly caloric food in the form of bacterial blends that roundworms are known to prefer; on the right was lower-quality food. (For these purposes, more calories equals high quality.) The team's prior experiments had already demonstrated that worms thrive and grow faster on higher-quality food and tend to preferentially seek it out.

Video of worms in a T-maze. Favored/superior food is at the end of the left arm. Non-favored/inferior food is at the end of the right arm. Most worms are immediately drawn to superior food, but some try the inferior before settling on the superior food. Video of worms in a T-maze. Favored/superior food is at the end of the left arm. Non-favored/inferior food is at the end of the right arm. Most worms are immediately drawn to superior food, but some try the inferior before settling on the superior food.

The same held true for the T-maze experiments under normal conditions, i.E., roundworms that had not been dosed with anandamide. But that preference for high-quality food was even more pronounced in the dosed roundworms, which flocked in droves to the left and stayed there longer than usual. In addition, Lockery's team found that the olfactory neuron needed to enable the worms' food-seeking chemotaxis became more sensitive to higher-quality food under the influence of anandamide.

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The team was also able to identify the necessary NPR-19 cannabinoid receptor in the roundworms, and they replaced this gene with a human CB1 receptor-gene in follow-up experiments. The "munchies effect" still persisted, indicating a strong similarity in response between C. Elegans and humans. Per Lockery et al., these results emphasize how evolutionarily ancient the endocannabinoid system is, since C. Elegans hasn't shared any common ancestor with humans for more than 600 million years.

And it means that roundworms could find yet another area in which they serve as useful research models: exploring the medicinal benefits of cannabis-based drugs. For instance, cancer patients often use cannabis to boost appetite and help manage pain, but because the drug binds broadly to endocannabinoid receptors, it can also make it more difficult to focus. Then there is the case of rimonabant, an anti-obesity drug approved in Europe in 2006 that worked by blocking CB1 receptors. It helped patients lose weight, but it also made them suicidal. The drug was pulled from the market in 2008.

Future experiments with stoned C. Elegans specimens could help scientists learn more about the endocannabinoid system and better target future medications to just the most relevant receptors, offering relief with fewer side effects.

DOI: Current Biology, 2023. 10.1016/j.Cub.2023.03.013  (About DOIs).

Oyster Mushroom Venom Kills Roundworms—So The Mushrooms Can Feast

Oyster mushrooms feature in cuisines around the world, but they should be off the menu for hungry worms—which these delicious fungi kill and devour with abandon. Now researchers finally know how they do it.

A study published in Science Advances details how oyster mushrooms use a particular toxin to paralyze and knock off fungus-eating roundworms called nematodes. The fungi, which grow on nutrient-poor rotting wood, then consume the nitrogen-rich worms.

"Nematodes happen to be the most abundant animals these fungi encounter, so I think it's very interesting evolutionarily, this cross-kingdom prey interaction," says study senior author Yen-Ping Hsueh, a molecular biologist at Academia Sinica in Taiwan.

The study team of geneticists, molecular biologists, biochemists and fungal biologists had previously found that oyster mushrooms exude an unidentified toxin that somehow paralyzes the worms within minutes and causes calcium to flow into their cells, killing them. This mechanism differs from those used by other carnivorous fungi and could be unique to oyster mushrooms.

For their new work, the researchers grew and analyzed samples of the fungi's tissue, finding no noticeable toxin even when they broke it up. They reasoned that whatever was killing the worms must be a volatile compound that evaporates when disturbed. When they damaged the oyster mushroom tissue again and then analyzed the nearby air with gas chromatography–mass spectrometry, they finally found 3-octanone—a nerve gas that turned out to be encapsulated in microscopic, lollipop-shaped structures on the mushroom surface. When nematodes touch the mushrooms, these structures release their gas, disrupting the worms' cell membranes to cause paralysis and death. The worm is then digested via the mycelium, a mushroom's threadlike feeding network.

Before this work, "we didn't really appreciate how many fungi in the wild are defending themselves against nematodes or even using nematodes as food," says Nick Talbot, a geneticist at Sainsbury Laboratory in Norwich, England, who studies how fungi can harm plants but was not involved in the new research. The study demonstrates "a very novel approach," he adds. "These organisms are really difficult to work on, and Dr. Hsueh is showing that you can do some really amazing work with them."

This article was originally published with the title "Science in Images" in Scientific American 328, 4, 18-19 (April 2023)

doi:10.1038/scientificamerican0423-18

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