The Discovery of the GSH Receptor in Hydra and Its Evolutionary Significance
Christopher A. Shaw in Glutathione in the Nervous System, 2018
The following are the main features of the assay we developed: A hydra in the absence of glutathione is shown in Fig. 1 A: the mouth is closed, and the tentacles are outstretched and nearly motionless. After glutathione is added, the tentacles begin to writhe and sweep inwards toward the central vertical axis of the animal (Fig. 1 B). Next, the tentacles bend toward the mouth, and the mouth opens (Fig. 1 C). Shown in this composite drawing (Fig. 1 C) are the various positions that a tentacle takes before contracting. These movements, culminating in mouth opening, usually all take place within one-half minute. Figure 1D shows how a hydra looks during the greater portion of the feeding response, its mouth open wide and the tentacles in various phases of contraction. Frequently, the tips of the tentacles are observed within the hydra’s mouth, as shown in Fig. 1C and D.
Mapping network disturbances
Paul M.W. Hackett, Christopher M. Hayre in Handbook of Ethnography in Healthcare Research, 2020
At night, corals extend their stinging tentacles to catch small floating animals called zooplankton, and the prey is pulled into the corals’ mouths and digested. However, the waters surrounding coral reef ecosystems are known to be nutrient poor, so corals need other ways to supplement their diet. They have entered into a unique relationship with single-celled plant-like organisms called dinoflagellates. Also known as zooxanthellae, the algae live inside coral cells, and here they get energy from photosynthesis. Instead of preserving the organic carbon the algae make, they release up to 95% to their host. The coral animals use this energy to grow, reproduce and build their skeletons. In return, the zooxanthellae receive inorganic nutrients from the waste metabolism of the coral. The coral relies on photosynthesis by zooxanthellae and are thus limited to inhabiting the shallow photic zone where sufficient light is available. This relationship between plant and animal is referred to as mutualistic endosymbiosis because the algae live inside the coral body and both plant and animal benefit from their mutual exchange. It is the microscopic zooxanthellae that live in the translucent tissue of the coral that give the reef skeletons their characteristic brown, green, and purple colors. (Hoegh-Guldberg & Dove, 2019, p. 97; Hopley & Smithers, 2019, p. 10).
Beach lifeguard first aid
Mike Tipton, Adam Wooler in The Science of Beach Lifeguarding, 2018
For stingrays, stonefish, lionfish, Portuguese man-of-war (Physalia physalis), weever fish and sea urchins, immersion in hot water can provide pain relief. All tropical Australian jellyfish, including the box jellyfish (Chironex fleckeri), should be treated with decontamination from cold seawater, followed by 5% acetic acid (vinegar). If acetic acid is unavailable, then a slurry of baking soda and water can be used. There is some conflicting literature that acetic acid may increase the amount of venom released by some species; however, more rigorous evidence exists that it stops the stinging process. There are conflicting studies on hot water immersion versus application of cold packs and cold water. A reasonable approach for all other jellyfish is to attempt hot water immersion for 20 minutes after application of 5% acetic acid (vinegar), or application of cold if more readily available. Decontamination by removing tentacles should be performed while wearing gloves to prevent injury to the lifeguard. Pressure bandages should be avoided and may increase the amount of venom released.
Delayed deep dermal necrosis after jellyfish sting in a 4-year-old female infant
Published in Case Reports in Plastic Surgery and Hand Surgery, 2018
Diana Desax-Willer, Thomas Krebs, Samuel Christen
A 4-year-old female infant, the daughter of a Thai mother and a Swiss father, was stung by a jellyfish during their holidays in Hua Hin, Thailand. The incident occurred at the beach in shallow water. The animal was described to be transparent and had long tentacles (approximately 1 m). The girl immediately experienced intense pain and developed reddish sting marks on her legs. Vinegar was immediately poured over the sting marks. Four hours later, the girl was treated at the local hospital with an unknown topical cream. Five days later, she was presented to the surgical department of a hospital in Bangkok (Figures 1, 2). She continued to report pain. According to information provided by the attending doctor, the skin marks were dry, without signs of infection, and there was a mild swelling of the left leg. Systemic therapy with oral prednisone and local treatment with Silvex® cream (containing sulfadiazine and silver) was initiated. The girl developed intense local itching, scabbing occurred, and perifocal redness increased.
Upcycling of jellyfish (Nemopilema nomurai) sea wastes as highly valuable reducing agents for green synthesis of gold nanoparticles and their antitumor and anti-inflammatory activity
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Eun-Young Ahn, Su Jung Hwang, Myung-Jin Choi, Seonho Cho, Hyo-Jong Lee, Youmie Park
The jellyfish extract was prepared according to our previous report [21]. In August 2012, the jellyfish (N. nomurai) was collected at the Eastern South Sea (Hak-dong, Geoje-shi, Republic of Korea). Their bell diameter was 80 cm. The tentacle part was separated from of the jellyfish and extensively washed with deionized water. After washing, the freeze-drying process of the tentacle part was processed on a FD5505 model freeze-dryer (Il Shin Bio, Seoul, Republic of Korea). The powdered sample (1 g) was dispersed in deionized water (40 ml). The sonication was performed for 30 min at ambient temperature to hasten the dispersion process and dissolve soluble materials in deionized water. Insoluble materials were removed by centrifugation (5067g force, 50 min, 22 °C). Then, the supernatant was taken and subjected to filteration process through a filter paper followed by a cellulose syringe filter (0.2 μm). The filtrate was freeze-dried and labelled as jellyfish extract. This material was used for the synthesis of JF-AuNPs in the followings.
Gut microbiota: what is its place in pharmacology?
Published in Expert Review of Clinical Pharmacology, 2019
Aleksandra Tarasiuk, Jakub Fichna
In the stomach, which is lined with a single layer of squamous epithelium, its cells are responsible for the secretion of hydrochloric acid, digestive enzymes, and mucus. In the small intestine, a thick type of epithelium is present – single-layer cubic or columnar, constituting a natural protective barrier. It performs both secretory and transport functions, related to the absorption of many substances. The epithelial surface in the small intestine is characterized by the presence of numerous cavities and folds, formed by glands, crypts, and villi, which is an expression of the adaptation of this part of the GI tract to the function performed. The epithelium of the intestinal villi consists of capillary epithelial cells. It is formed by single tentacles, so-called microvilli that also increase its surface. Under the epithelium of the villi, in the middle of the lamina propria, a network of lymph vessels is located. Enterocytes are alternated with intestinal goblet cells secreting mucus. The core of the intestinal villi consists of cylindrical, straight cavities that extend to the muscular layer but are not penetrating. At the bottom of the crypts there are stem cells, and above them, Paneth cells, secreting antibacterial lysozyme. The epithelium located above the lymphoid cells of the intestine, in which Peyer’s patches are present, is a characteristic area of the intestine due to the microcavities and microfold cells located there. The main role of these cells is both the recovery of shortened or irregular villi or pits, as well as the transport of microorganisms from the intestinal lumen to deeper epithelial layers.
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