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Fungi and Water
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Fungi have cell walls similar to plants and are different from animals. The fungal cell wall is composed of chitin that gives shape, form, and rigidity to fungi. It protects against mechanical injury, prevents osmotic lysis, and provides passive protection against the ingress of potentially harmful macromolecules (2–3). Chitin is a polymer of N-acetyl-D-glucosamine. The major polysaccharides of the cell wall matrix consist of non-cellulosic glucans such as glycogen-like compounds, mannans (polymers of mannose), chitosan (polymers of glucosamine), and galactans (polymers of galactose). Small amounts of fucose, rhamnose, xylose, and uronic acids may be present (2). Glucan refers to a large group of D-glucose polymers having glycosidic bonds. Insoluble β-glucans are apparently amorphous in the cell wall. Yeast cell wall is composed of three layers and is about 200- to 600-nm thick. Its inner surface is chitinous, and its outer layer contains α-glucan (2). In addition to chitin, glucan, and mannan, cell walls may contain lipid, protein, chitosan, acid phosphatase, α-amylase, protease, melanin, and inorganic ions such as phosphorus, calcium, and magnesium (2). The fungal wall also protects cells against mechanical injury and blocks the ingress of toxic macromolecules. The fungal cell wall is also essential to prevent osmotic lysis. Even a small lesion in the cell wall can result in extrusion of cytoplasm due to the internal (turgor) pressure of the protoplast. The cell membrane of a fungus has a unique sterol and ergosterol (3).
Effect of Elevated CO2 Conditions on Medicinal Plants
Published in Azamal Husen, Environmental Pollution and Medicinal Plants, 2022
Anuj Choudhary, Antul Kumar, Harmanjot Kaur, Mandeep Singh, Gurparsad Singh Suri, Gurleen Kaur, Sahil Mehta
Elevation in photosynthetic activity in plants is potentially related to rising inactivity of RuBisCO (ribulose 1,5-bisphosphate carboxylase enzyme) which can alter growth as well as production of secondary metabolites (Portis et al. 2007). Under higher carbon dioxide conditions, there is an increment in the rate at which carbon is subsumed into carbohydrates; this continues as RuBisCO becomes one of the limiting factors. The higher CO2 levels result in rapid leaf area development, which further increases the surface for transpiration and an enhanced rate of transpiration (Betts et al. 2007). There is an abrupt increase in stomatal conductance which causes the rapid opening of stomatal guard cells under e[CO2] in the atmosphere. There is also a significant improvement in the water-use efficiency of plants through increased turgor pressure which is important in the growth and development process.
Hair transplantation
Published in John Dudley Langdon, Mohan Francis Patel, Robert Andrew Ord, Peter Brennan, Operative Oral and Maxillofacial Surgery, 2017
N Ravindranathan, E Antonio Mangubat
The incision lines should be parallel to the orientation of the hair follicles to avoid transection and parallel to the lines of minimum tension (Figure 81.9). Use local anaesthesia in the strength of 1% lignocaine with 1:100,000 epinephrine (adrenaline) when using the tumescent technique. If using a multi-blade knife to harvest multiple strips, use the tumescent technique to achieve tissue turgor. Subsequently, 100 mL normal saline is injected into the donor site for tumescence to build up the turgor pressure.
Remodelling of the superficial vascular network of skin flaps in rats, following a vasodilatory cream application, before elevation
Published in Journal of Plastic Surgery and Hand Surgery, 2023
Glykeria Pantazi, Iraklis Evangelopoulos, Christos Evangelopoulos, Sofia Tilaveridou, Ioannis Iakovou, Athanassios Kyrgidis, Ioannis Tilaveridis
The beneficial effects of prostacyclins have been well documented, with both local and systemic application of prostaglandin Ε1 (PGE1) and PGI2 showing positive effects on flap survival [9,19]. Additionally, experiments using both PGE1 and PGI2 consistently report improvements in skin flap survival and/or increased blood flow in the proximal region [9,20,21], with PGI2 reportedly outperforming PGE1 in these areas [22]. Previous studies described improvements in thigh-vein circulation following PGI2 administration and that PGI2 treatment decreased turgor pressure in the arterial wall, resulting in decreased interference of blood flow and clot formation [23,24]. Moreover, systemic administration of PGI2 has also been associated increased flap survival rates [15]; however, these application have little therapeutic value due to the chemical instability and small half-life of PGI2 (2–3 min at pH 7.5 and 37 °C). Furthermore, Emerson and Sykes [19] reported negative results associated with flap survival following local and intraperitoneal administration of PGI2 prior to surgery, attributing this to the short half-life of the drug; however, a later experiment injecting PGI2 at both the beginning of surgery and post-operation revealed an increase in flap survival.
Exosomes: from biology to immunotherapy in infectious diseases
Published in Infectious Diseases, 2023
Velia Verónica Rangel-Ramírez, Hilda Minerva González-Sánchez, César Lucio-García
In fungi, extracellular vesicles were discovered more than a decade ago in the pathogen Cryptococcus neoformans [337]. In contrast to mammalian cells and similarly to Gram-positive bacteria, these fungal-vesicles have to traverse a cell wall to be released, however, until now, many steps of this process are still unknown [338]. It has been suggested that vesicles would pass through channels for their release, that cell wall is remodelled by enzymes facilitating areas for extracellular vesicles transit, or that they are forced to pass through cell wall pores by turgor pressure [338,339]. Moreover, secretion in the Fungi is particular, since the majority of proteins lack the signal peptide [340], and different secretory mechanisms may be involved including the conventional route (ER-Golgi pathway), the ESCRT-mediated pathway and the one involving the Golgi reassembly stacking proteins (GRASP) [311].
Bio-acoustic signaling; exploring the potential of sound as a mediator of low-dose radiation and stress responses in the environment
Published in International Journal of Radiation Biology, 2022
Bruno F. E. Matarèse, Jigar Lad, Colin Seymour, Paul N. Schofield, Carmel Mothersill
Drought stress and predation constitute two of the major physiological stressors of vascular plants. Under drought stress some plants produce measurable bio-acoustic emissions (De Roo et al. 2016). The mechanisms for generating these signals are not fully understood but may involve the effects of decreasing hydrostatic pressure in xylem, leading to the production of ultrasonic sound emissions variously measured as >20 kHz (Tyree and Dixon 1983) and from 10 to 300 kHz (Laschimke et al. 2006). With rapidly decreasing pressure in the xylem, collapse of bubbles caused by cavitation has been suggested as one mechanism for the generation of sound, but an alternative hypothesis derived to explain the ‘violent acoustic activity’ detected in Ulmus sp. in response to drought stress, is release of energy from the xylem-adherent bubble system that normally contributes to water flow (Laschimke et al. 2006; Zweifel and Zeugin 2008; Gagliano et al. 2012a, 2012b; Gagliano 2013). Respiration and metabolic growth activity of the cambium is another method suggested to be involved (Zweifel and Zeugin 2008). The cambium is the portion between the xylem and phloem where cells are rapidly dividing and is responsible for secondary growth of stems and roots (Zweifel and Zeugin 2008; Schöner et al. 2016). At nighttime when the plant is subject to drought stress, the cambium has increased turgor pressure due to increased respiration. This increased pressure causes greater levels of carbon dioxide to enter the xylem, resulting in more gas bubbles and subsequent acoustic emissions. In the absence of drought stress and consequent xylem cavitation, young corn roots are able to produce clicking sounds under water – the reason for retaining or developing this mechanism is unknown (Schöner et al. 2016). It is apparent that a variety of plant species have developed mechanisms for sound production.