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Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Propionibacterium acnes and Staphylococcus epidermidis are two of the bacteria that invade the hair follicles in the epidermal layers of the skin. They may not require overt injury to initiate infection. Infection causes excessive secretion by the sebaceous glands at the base of the hair follicles. A pus-filled pimple results. There is some evidence of a cell-mediated immune response. It does not appear to aid recovery. Hormonal disorders associated with puberty appear to be a factor in acne possibly by affecting the skin secretions in such a way as to facilitate microbial survival.
Welcome to the Intelligent Health Revolution
Published in Tom Lawry, Hacking Healthcare, 2022
Today, this is happening with intelligent devices that are external or wearable. In the future, smart sensors may be embedded under your skin, swallowed with your breakfast, or remain swimming in your bloodstream. They will constantly monitor your heart rate, respiration, temperature, skin secretions, and more.
Antiseptics, antibiotics and chemotherapy
Published in Michael J. O’Dowd, The History of Medications for Women, 2020
Bacterial resistance to antibiotics became a major problem in the mid- and late twentieth century, amidst calls for their prudent use, Robin Fox, editor of theJournal of the Royal Society of Medicine, in a leading article entitled ‘The post-antibiotic era beckons’ (1996), wrote of a new breed of antimicrobials, the magainins. Discovered in 1987 in the skin secretions of frogs and toads, the magainins are peptides with activity against a wide range of bacteria and fungi. Fox theorized that this new class of agents could save us from the threatened post-antibiotic era but added a note of caution, ‘If history repeats itself, the magainins will be sold as widely as possible; they will be misused; and resistant organisms will emerge. Frogs will wish they had kept their secret’.
Peptidomic analysis in the discovery of therapeutically valuable peptides in amphibian skin secretions
Published in Expert Review of Proteomics, 2019
J. Michael Conlon, Milena Mechkarska, Jérôme Leprince
A comparison of the amino acid sequences of these frog skin antimicrobial peptides (AMPs) reveals the lack of any conserved domains that are associated with biological activity. However, with very few exceptions, the peptides are cationic and contain at least 50% hydrophobic amino acids [9]. Circular dichroism and NMR studies have shown that they generally lack stable secondary structure in aqueous solutions but have the propensity to form an amphipathic α-helix in the environment of a phospholipid vesicle or in a membrane-mimetic solvent such as 50% trifluoroethanol-water [10]. There is no single mechanism by which peptides inhibit growth or produce cell death but their action does not involve binding to a specific receptor, rather a nonspecific interaction with the bacterial cell membrane that results in permeabilization and ultimate disintegration [11]. Consequently, the frog skin peptides are usually active against microorganisms that are resistant to currently available antibiotics due to their markedly different and highly destructive mode of action. The frog skin AMPs may be grouped together in peptide families on the basis of limited similarities in amino acid sequence. Skin secretions from a single species frequently contain several members of a particular family that are presumed to have arisen from multiple duplications of an ancestral gene [12]. The molecular heterogeneity of the peptides within a family is often considerable and this variation in primary structure is reflected in a wide variability in antimicrobial potencies and specificities for different microorganisms [13]. The precise role of AMPs in the overall defense strategy of the organism is far from clear and it has been suggested that, in some species at least, their primary role is to facilitate the action of toxins produced in the skin, such as bradykinin and caerulein, in the defense against predators [8,14].
Salamanders and caecilians, neglected from the chemical point of view
Published in Toxin Reviews, 2022
Isadora Alves de Vasconcelos, Jéssica Oliveira de Souza, Jessica Schneider de Castro, Carlos José Correia de Santana, Ana Carolina Martins Magalhães, Mariana de Souza Castro, Osmindo Rodrigues Pires Júnior
There are a few reports of biological activities in caecilian skin secretions. The skin secretion of the Tenmalai caecilian Gegeneophis ramaswamii (Grandisoniidae) was effective against Aeromonas hydrophila (MIC = 4.12 μg/mL), Klebsiella pneumonia (MIC = 6.25 μg/mL), and Escherichia coli (MIC = 6.25 μg/mL) (Arun et al.2019).