Seaweed
Phaeophyta
Sargassum
Fucus
Laminaria
Ulva
Chondrus
Gracilaria
Rhodophyta
Caulerpa
Laurencia
Undaria
Bahamas
Fucoxanthin as the major antioxidant in Hijikia fusiformis, a common edible seaweed. (1/243)
The radical scavenging activity of Japanese edible seaweeds was screened by the DPPH (1-diphenyl-2-picrylhydrazyl) assay to evaluate the DPPH radical scavenging activity in organic extracts. The fresh brown alga Hijikia fusiformis showed the strongest DPPH radical scavenging activity, followed by Undaria pinnatifida and Sargassum fulvellum. The major active compound from Hijikia fusiformis in its acetone extract was identified as fucoxanthin by 13C-NMR spectroscopy. (+info)Molecular phylogenetic evidence for a reversible morphogenetic switch controlling the gross morphology of two common genera of green seaweeds, Ulva and Enteromorpha. (2/243)
Ulva and Enteromorpha are two of the most common, ubiquitous, and environmentally important genera of green seaweeds. They are widely regarded as easily distinguishable because of their dramatically different morphologies: Ulva species are flat, lettucelike blades two cell layers thick, and Enteromorpha species form hollow liquid- or gas-filled tubes one cell thick, which may also be highly branched. We present molecular phylogenetic analyses of nuclear ribosomal RNA ITS sequences from 39 samples representing 21 purported species within these two genera. The results clearly indicate that the two genera are not respectively monophyletic and that the characteristic Ulva and Enteromorpha morphologies have arisen independently several times throughout the evolutionary diversification of the group. The analyses demonstrate that this radical change in gross morphology can also happen within clades exhibiting sequence divergence typical of conspecific assemblages of this group. We suggest that this morphological flexibility is the result of some form of developmental switch that results in either blades or tubes, but that this putative switch must be activated relatively infrequently, since there is evidence that some lineages have retained their form for significant periods. This discovery suggests a possible new model system for study of the molecular mechanisms involved in the interplay between environmental stimuli and plant development. (+info)Synaptic modulation contributes to firing pattern generation in jaw motor neurons during rejection of seaweed in Aplysia kurodai. (3/243)
Japanese species, Aplysia kurodai, feeds well on Ulva but rejects Gelidium (Geli.) or Pachydictyon (Pach.) with different rhythmic patterned movements of the jaws and radula. During ingestion the jaws open at the radula-protraction phase and remain half open at the initial phase of the radula-retraction, whereas during rejection the jaws open similarly but start to close immediately after the onset of the radula-retraction. These can be induced not only by the natural seaweed but by the extract solutions. We previously showed that the change of the patterned jaw movements from the ingestion to the rejection may result from the decrease in the delay of the firing onset of the jaw-closing (JC) motor neurons during their depolarization. This diminished delay produces a phase advance relative to the radula-retraction phase. In that study, we showed that during ingestion the buccal multiaction (MA) neurons may generate the delay of firing onset of the JC motor neurons by producing monosynaptic inhibitory postsynaptic potentials (IPSPs) during the initial portion of their depolarization. In the present experiments, the firing patterns in the MA neurons induced by application of the Geli. or Pach. extract to the lips were explored in the semi-intact preparations. During the Pach. response the duration and the firing frequency of the MA firing at each depolarizing phase were decreased in comparison with the Ulva response. No decreases in the MA firing were observed during the Geli. response, suggesting that the similar patterned jaw movements during rejection of Geli. and Pach. may be generated by different neural mechanisms. Moreover, the size of the MA-induced IPSP in the JC motor neurons was largely decreased by application of the Geli. or Pach. extract to the lips in the reduced preparations consisting of the tentacle-lips and the cerebral-buccal ganglia. Voltage-clamp experiments on the JC motor neurons showed that the size of synaptic current induced by the MA spikes was decreased by application of these solutions to the lips. The decrease was induced when the buccal ganglia were bathed in a solution to block polysynaptic pathways. These results suggest that the advance of the onset of the JC firing at each depolarizing phase during the Geli. or Pach. response may be mainly or partly caused by the decrease in the size of the MA-induced IPSP in the motor neurons. Modulatory action of cerebral neurons or peripheral afferent neurons in the lip region may contribute to this synaptic plasticity. (+info)Are there mechanical limits to size in wave-swept organisms? (4/243)
Hydrodynamic forces imposed by ocean waves are thought to limit the size of nearshore plants and animals, but it has proved difficult to determine the mechanism. Explanations based on the scaling mismatch between hydrodynamic accelerational forces and the strength of organisms do not work. Mechanisms that incorporate the allometry of drag and strength accurately predict the maximal size of intertidal algae but not of animals, and internally imposed inertial forces may explain the limits to size in large kelps. The general question of size in wave-swept organisms remains open and intriguing. (+info)Ecological biomechanics of benthic organisms: life history, mechanical design and temporal patterns of mechanical stress. (5/243)
We can gain biomechanical insights if we couple knowledge of the environments, ecological roles and life history strategies of organisms with our laboratory analyses of their mechanical function or fluid dynamics, as illustrated by studies of the mechanical design of bottom-dwelling marine organisms. Obviously, measurements of the spatial and temporal distribution of loads on an organism in nature reveal the magnitudes and rates at which biomechanical tests should be performed in the laboratory. Furthermore, knowledge of the population biology and ecological interactions of the organisms being studied is crucial to determine when during the life of an individual particular aspects of mechanical performance should be measured; not only can the size, shape and material properties of an individual change during ontogeny, but so can its habitat, activities and ecological role. Such ecological information is also necessary to determine whether the aspects of mechanical performance being studied are biologically important, i.e. whether they affect the survivorship or fitness of the organisms. My point in raising these examples is to illustrate how ecological studies can enhance or change our understanding of biomechanical function. (+info)Dietary iodine intake and urinary iodine excretion in patients with thyroid diseases. (6/243)
This study was conducted to examine the usual iodine intake in patients with thyroid diseases and to compare iodine status with normal subjects. The dietary iodine intake was assessed using a semi-quantitative food frequency questionnaire, and urinary iodine excretion was measured in 184 patients diagnosed with thyroid diseases and 207 normal subjects. The average usual iodine intake of patients with thyroid diseases was 673.8 +/- 794.9 ug/day and that of normal subjects was 468.9 +/- 481.9 ug/day. Among the patients with thyroid diseases, higher values were found in the patients with thyroid cancer (1460.6 +/- 1044.8 ug/day) and lower values were found in patients with simple goiter (443.5 +/- 470.4 ug/day). The urinary iodine excretions of patients and normal subjects were 4.33 +/- 5.70 mg/L and 2.11 +/- 0.69 mg/L, respectively. The iodine intake and urinary iodine excretion of patients with thyroid diseases were significantly higher than those of normal subjects (p < 0.05). The dietary iodine intake and urinary excretion of patients with thyroid cancer were significantly higher than other patients with thyroid diseases and normal subjects because of the use of seaweed or seaweed-containing dietary supplements (p < 0.01). This study suggests that the habitual ingestion of seaweed-containing dietary supplements in addition to dietary iodine intake will have adverse effects due to its excessive iodine intake. (+info)Water-borne cues induce chemical defense in a marine alga (Ascophyllum nodosum). (7/243)
It is well known that herbivores can induce chemical defenses in terrestrial vascular plants, but few examples of inducible production of defense chemicals have been reported for aquatic macrophytes. Furthermore, it is well established that water-borne chemical cues from predators or predator-wounded conspecifics can induce defensive changes of aquatic prey animals, but no such communication between aquatic herbivores and seaweeds has been reported. Here we show that water-borne cues from actively feeding herbivorous gastropods, flat periwinkles (Littorina obtusata), can serve as external signals to induce production of defense chemicals (phlorotannins) in unharmed individuals of seaweeds, knotted wrack (Ascophyllum nodosum), and that the increased levels of defense chemicals deter further feeding by periwinkles. Because seaweeds have poorly developed internal-transport systems and may not be able to elicit systemic-induced chemical defenses through conveyance of internal signals, this mechanism ensures that seaweeds can anticipate future periwinkle attacks without receiving direct damage by herbivores. (+info)Sulfoxidation mechanism of vanadium bromoperoxidase from Ascophyllum nodosum. Evidence for direct oxygen transfer catalysis. (8/243)
We have previously shown that vanadium bromoperoxidase from Ascophyllum nodosum mediates production of the (R)-enantiomer of methyl phenyl sulfoxide with 91% enantiomeric excess. Investigation of the intrinsic selectivity of vanadium bromoperoxidase reveals that the enzyme catalyzes the sulfoxidation of methyl phenyl sulfide in a purely enantioselective manner. The K(m) of the enzyme for methyl phenyl sulfide was determined to be approximately 3.5 mM in the presence of 25% methanol or tert-butanol. The selectivity of the sulfoxidation of methyl phenyl sulfide is optimal in the temperature range 25-30 degrees C and can be further optimized by increasing the enzyme concentration, yielding selectivities with up to 96% enantiomeric excess. Furthermore, we established for the first time that vanadium bromoperoxidase is functional at temperatures up to 70 degrees C. A detailed investigation of the sulfoxidation activity of this enzyme using (18)O-labeled hydrogen peroxide shows that vanadium bromoperoxidase mediates the direct transfer of the peroxide oxygen to the sulfide. A schematic model of the vanadium haloperoxidase sulfoxidation mechanism is presented. (+info)I'm sorry for any confusion, but seaweed is not typically referred to in medical definitions. Seaweed is a common name for various marine macroalgae, which are multicellular aquatic plants found in the ocean. They are often consumed as food and have been used in traditional medicine in some cultures. However, there is no widely accepted medical definition for seaweed. If you're looking for information about a specific compound or substance derived from seaweed that might be relevant to medical definitions, I would be happy to help if you could provide more details.
Phaeophyta is a taxonomic division that refers to a group of complex, multicellular brown algae found in marine environments. These algae are characterized by their pigmentation, which includes fucoxanthin, chlorophyll-a, and chlorophyll-c, giving them a brown color. They have diverse morphology, ranging from simple thread-like forms to large seaweeds.
Phaeophyta species are primarily found in cold, nutrient-rich waters and play an essential role in marine ecosystems as primary producers and habitats for various marine organisms. Some examples of Phaeophyta include kelps, rockweed, and bladderwrack. It's worth noting that the classification and nomenclature of algae are continually evolving, so different sources might use slightly different terminology or categorization.
I'm sorry for any confusion, but "Sargassum" is not a medical term. It refers to a type of brown seaweed or macroalgae that floats in the ocean and forms large floating mats. The two main species are Sargassum natans and Sargassum fluitans. These seaweeds are named after the Sargasso Sea, a region in the Atlantic Ocean known for its dense population of Sargassum. If you have any questions related to medical terminology or health-related topics, I would be happy to help!
"Fucus" is a genus of brown seaweed that commonly goes by the name "bladderwrack." It's often found in cooler waters in the Northern Hemisphere, particularly in the Baltic Sea and the Atlantic and Pacific Oceans.
In a medical or pharmacological context, "fucus" is sometimes used to refer specifically to the extracts or compounds derived from this seaweed. These extracts contain various substances, such as iodine, fucoidan, fucoxanthin, and alginic acid, which have been studied for their potential health benefits.
For example, fucoidan has been investigated for its anti-inflammatory, anticoagulant, and antitumor properties, while fucoxanthin has shown promise in weight loss studies due to its potential to increase metabolism. However, more research is needed to confirm these effects and establish recommended dosages and safety guidelines.
It's important to note that while some natural health products may contain fucus extracts, they should not be used as a substitute for medical treatment or professional advice. Always consult with a healthcare provider before starting any new supplement regimen.
"Laminaria" is a genus of brown algae that grows in cooler waters and is often used in medical procedures as a preparation for dilating the cervix. The dried and sterilized form of Laminaria japonica, a species of this seaweed, is known as "Laminaria tents" or "Laminaria sticks." These are gradually inserted into the cervix where they absorb water and expand over a period of hours, dilating the cervix. This is most commonly done in preparation for a surgical procedure such as a dilation and curettage (D&C) or an abortion. It's important to note that this process should be performed by a healthcare professional in a clinical setting.
"Ulva" is a genus of green algae, also known as sea lettuce. It is a common marine plant that can be found in both fresh and saltwater environments worldwide. Ulva species are characterized by their thin, leaf-like blades that can vary in color from bright green to yellowish-green. They play an essential role in the aquatic ecosystem as they provide food and shelter for various marine organisms. Additionally, they can reproduce both sexually and asexually, contributing to their rapid growth and ability to form large colonies or mats. However, when they grow excessively, they can become a nuisance, known as "green tides," which can have negative impacts on the environment and local economies.
'Chondrus' is a medical term that refers to a type of red algae (seaweed) commonly known as Irish moss. It belongs to the family Gigartinaceae and the genus Chondrus. This type of algae is often found in the colder waters of the North Atlantic Ocean, particularly around Europe and North America.
Chondrus is widely used in various industries due to its unique properties. In the food industry, it is commonly used as a thickener, emulsifier, and stabilizer in products such as ice cream, salad dressings, and baked goods. It contains a polysaccharide called carrageenan, which has these gelling and thickening abilities.
In addition to its industrial uses, Chondrus also holds potential health benefits. Some studies suggest that it may have anti-inflammatory, antiviral, and anticoagulant properties. However, more research is needed to fully understand its potential therapeutic applications.
"Gracilaria" is not a medical term. It is a genus of red algae that is often found in marine environments, particularly in tropical and subtropical waters. These algae are commonly used in aquaculture for the production of fish feed and as a source of carrageenan, a substance used in food and industrial applications as a thickener and stabilizer.
There is no medical significance or application associated with Gracilaria. If you have any questions about marine biology or other scientific topics, I would be happy to help answer them!
I believe there might be a misunderstanding in your question. In medical terms, there is no definition for "tidal waves." However, the term "tidal wave" is commonly used in layman's language to refer to massive waves caused by earthquakes or underwater landslides, which are technically called tsunamis. Tsunamis are rapid, long-wavelength sea waves that can cause extensive coastal damage and loss of life.
If you meant a different term related to medicine or healthcare, please clarify so I can provide an accurate definition.
Rhodophyta, also known as red algae, is a division of simple, multicellular and complex marine algae. These organisms are characterized by their red pigmentation due to the presence of phycobiliproteins, specifically R-phycoerythrin and phycocyanin. They lack flagella and centrioles at any stage of their life cycle. The cell walls of Rhodophyta contain cellulose and various sulphated polysaccharides. Some species have calcium carbonate deposits in their cell walls, which contribute to the formation of coral reefs. Reproduction in these organisms is typically alternation of generations with a dominant gametophyte generation. They are an important source of food for many marine animals and have commercial value as well, particularly for the production of agar, carrageenan, and other products used in the food, pharmaceutical, and cosmetic industries.
'Caulerpa' is not a medical term, but a taxonomic genus name for a type of green seaweed or algae that belongs to the family Caulerpaceae. It is commonly found in tropical and subtropical marine environments around the world. Some species of Caulerpa are known to produce potent toxins that can be harmful to humans and other animals if ingested, although most species are not toxic.
While 'Caulerpa' itself is not a medical term, some research has been conducted on the potential medicinal properties of certain compounds found in Caulerpa species. For example, some studies have suggested that extracts from Caulerpa racemosa may have anti-inflammatory and antioxidant effects, while other research has explored the potential use of Caulerpa taxifolia as a source of bioactive compounds with potential applications in cancer therapy. However, more research is needed to confirm these findings and determine the safety and efficacy of any potential medical uses for Caulerpa species.
I apologize for any confusion, but "Laurencia" is not a commonly used medical term or diagnosis. It is possible that you may be referring to "Laurasia," which is a geological supercontinent that existed during the early Mesozoic Era, but it is not a medical concept. If you have a different context or meaning in mind, please provide more information so I can give a more accurate response.
Undaria is a type of brown seaweed that belongs to the family Alariaceae. The scientific name for this species is Undaria pinnatifida, and it is also commonly known as wakame in Japan. This seaweed is native to the coasts of Japan, Korea, and China, but has been introduced and become invasive in other parts of the world, such as Europe and New Zealand.
Undaria is a popular ingredient in Asian cuisine, particularly in miso soup and salads. It is also used in traditional medicine in some countries. In recent years, Undaria has gained attention for its potential health benefits, including its high content of dietary fiber, omega-3 fatty acids, iodine, and various minerals and vitamins. Some studies have suggested that Undaria may have anti-inflammatory, antioxidant, and anticancer properties, although more research is needed to confirm these effects and establish safe and effective dosages.
It's worth noting that while Undaria has potential health benefits, it can also accumulate heavy metals and other pollutants from the environment, so it's important to source it from reputable suppliers and consume it in moderation.
## I'm sorry for any confusion, but the term 'Bahamas' is not a medical definition. It refers to a country in the Atlantic Ocean, north of Cuba and northwest of the Turks and Caicos Islands. The Bahamas is an archipelago of about 700 islands and cays, and is known for its beautiful beaches, coral reefs, and tropical climate.
If you have any medical question or looking for a medical term, please provide more information so I can give you accurate and helpful information.