Pneumocystis carinii
Peter D. Walzer, Robert M. Genta in Parasitic Infections in the Compromised Host, 2020
The shape of the trophic form is quite pleomorphic and appears to be related to the method of fixation. In lung sections, P. carinii trophozoites have an irregular ameboid appearance, whereas in unfixed preparations examined under phase or Nomarski interference contrast microscopy, their shape becomes ellipsoidal and resembles a cluster of grapes (97). The boundaries of an individual organism in this developmental stage are defined by a cell wall that measures approximately 20-30 μm across and consists of three layers: an outer, electron-dense layer; a middle, electron-translucent layer; and an inner, trilaminar unit membrane characteristic of a plasmalemma (86). The term cell wall is used here to describe the constraints of this form and all other stages of P. carinii, since "pellicle" denotes inclusion of supportive, flattened alveolar sacks, which have not been observed in any stage of P. carinii. Discontinuities on the cell wall surface are a characteristic feature; filopodia or tubular extensions are easily observed by ultrathin microscopy (75,82). The diameter of these projections varies, and the lumen is usually filled with dense granular material (83). It has been postulated that these expansions are used for nutritional uptake, attachment to host cells, or as a means of communication between organisms (80).
Envisioning Utilization of Super Grains for Healthcare
Megh R. Goyal, Preeti Birwal, Santosh K. Mishra in Phytochemicals and Medicinal Plants in Food Design, 2022
Carbohydrates are the primary source of the energy in the human body. They are the important structural component of the cell wall and also involve in the various body functions. Carbohydrates account for the largest component in the composition of various grains. Major carbohydrates include starch, stachyose, sucrose, fructose, and glucose. The concentration of the starch as well as the activities of starch hydrolysis enzymes are very important factors. At present, the trend is shifting to foods with low starch digestibility as lower digestible starches lead to low glycemic response, which is highly beneficial for diabetic patients [42]. Dietary fiber is also a part of carbohydrates. The optimum concentrations (25–30 g/day) of the dietary fiber imparts various health benefits. Some of the beneficial effects include the reduction of coronary heart disease, cancer, diabetes, cholesterol, weight reduction, and improvement in the gut microflora functioning. The ratio of soluble and insoluble dietary fiber defines the functionality of this component which 1:3 (soluble to insoluble fiber) as recommended by The American Dietetic Association [24, 123]. However, higher levels of dietary fiber can also lower the bioaccessibility of proteins and minerals by binding them [12].
Plant Source Foods
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
Cell walls play different roles in plant cells. They aid in providing the overall form, growth, and development of the plant body (9). Despite the fact that the contents of plant cell walls differ from those of fungi and animals, certain functional aspects are similar. These include roles in cell protection, intercellular communication, cell adhesion and proliferation, and also in plant-microbe interactions for the defense against potential pathogens (9). Plant cell walls are usually divided into two categories: primary walls that surround growing cells or cells capable of growth, and secondary walls that are thickened structures containing lignin and surrounding specialized cells such as vessel elements or fiber cells. Plant cell wall is made up of about 90% carbohydrates and 10% proteins (6). The main constituent of plant cell walls is cellulose, which gives cells rigidity and strength, offering protection against mechanical stress (6, 9).
Vision of bacterial ghosts as drug carriers mandates accepting the effect of cell membrane on drug loading
Published in Drug Development and Industrial Pharmacy, 2020
Fars K. Alanazi, Abdulaziz A. Alsuwyeh, Nazrul Haq, Mounir M. Salem-Bekhit, Abdullah Al-Dhfyan, Faiyaz Shakeel
Gram negative envelope, cell wall, and inner plasma membrane, can affect both drug loading and release. Cell wall is composed of outer membrane, peptidoglycan layer, and periplasm [25]. The outer membrane is rich in lipid while the peptidoglycan layer is thin. Therefore, understanding the role of these components leads to better understanding of drug transport. Thus, the outer membrane has selective permeability since it is porous to certain substances. Periplasmic constituent works as border guard to maintain cells’ live-hood due to its gel like entrapping matrices. Moreover, cell wall can persist pressure up to 3 atm. It also gives bacteria the protection against extreme change in pH and temperature. Finally, the cell wall considers tough, elastic and plays important role in drug trafficking in or out the BGs. The amount of DOX loaded inside the BGs was determined in this study instead of its determination on the surface of BGs. Hence, this process can be considered as an encapsulation instead of adsorption of DOX on the surface of BGs. In addition, the current study is focusing on selected factors that could be controlled to ensure drug loading in the following section.
Cancer Chemopreventive, Antiproliferative, and Superoxide Anion Scavenging Properties of Kluyveromyces marxianus and Saccharomyces cerevisiae var. boulardii Cell Wall Components
Published in Nutrition and Cancer, 2018
Olivier Fortin, Blanca Aguilar-Uscanga, Khanh Dang Vu, Stephane Salmieri, Monique Lacroix
In this context, this study focused on the chemopreventive, antiradical, and antiproliferative properties of cell wall extracts of S. boulardii and K. marxianus with a focus on polysaccharides (glucan, chitin, and mannan). To that extent, the content, the relative concentrations, and the molecular weight of the polysaccharides typically found in yeast cell wall were determined. Then, the cancer chemopreventive potential of the extracts was investigated and compared with commercial insoluble glucans of S. cerevisiae. Nicotinamide adenine dinucleotide phosphate hydrogen: quinone reductase (QR) assay has been selected as cancer chemopreventive test for its direct role in protection against toxic electrophilic metabolites directly involved in the very first stage of carcinogenesis process whereas superoxide (O2−) anion was selected since it is one of the most important reactive oxygen species (ROS) due to its ability to generate hydrogen peroxide and OH− radicals (21). Finally, structure–function relationships between the cell wall composition and their biological activities were proposed.
Characterization of the nano–bio interaction between metallic oxide nanomaterials and freshwater microalgae using flow cytometry
Published in Nanotoxicology, 2020
Andrea Rivero Arze, Nicolas Manier, Amélie Chatel, Catherine Mouneyrac
Concerning the contact test with microalgae, dose–response profiles were found for each algae–NMs couples, and D. subspicatus showed the lowest percentage of granularity modification while C. vulgaris showed the highest being closely followed by R. subcapitata. This phenomenon may be linked to the algae cell wall composition. The algae cell walls represent a complex and related species network of variously modified (glycol)proteins, carbohydrates (cellulose, hemicellulose, pectin), and polysaccharide highly organized in a form of a supra-structure which constitutes the cell microenvironment (Alberts et al. 2002),. In addition, structural proteins are found in various content in most algae cell walls, they are classified as hydroxyproline-rich glycoproteins (HRGP), arabinogalactan proteins (AGP), glycine-rich proteins (GRPs), and proline-rich proteins (PRPs; Showalter 1993). Recent work has shown that proteins containing more specifically arginine and proline had a strong adsorption to NMs (Mathé et al. 2013) and C. vulgaris cell wall is rich in prolines (Abo-Shady, Mohamed, and Lasheen 1993) which may explain their higher interaction with NMs.