Biological evaluation of mechanically deboned chicken meat protein quality

Mechanically deboned chicken meat (MDCM) is a meat product obtained by crushing tissues after meat removal and is largely used in meat products. Protein quality of flour prepared from defatted MDCM and from fresh chicken breast meat (FCBM) was chemically and biologically evaluated by rat growth and nitrogen balance studies. Proximate chemical composition, on a dry basis, of MDCM and FCBM showed protein contents of 90.5% and 82.2%, lipid contents of 3.0% and 13.2% and ash contents of 6.1% and 4.2%, respectively. There was a relatively good balance of essential amino acids in both samples although lysine was in low concentration in MDCM being a limiting amino acid. Feeding of flour diets resulted in high protein efficiency ratio, a high net protein utilization and high nitrogen balance, thus showing a high biological value and also high true digestibility and, consistently, NPU for both samples is similar to casein.     

Pulsed Electromagnetic Fields in Bone Healing: Molecular Pathways and Clinical Applications

In this article, we provide an extensive review of the recent literature of the signaling pathways modulated by Pulsed Electromagnetic Fields (PEMFs) and PEMFs clinical application. A review of the literature was performed on two medical electronic databases (PubMed and Embase) from 3 to 5 March 2021. Three authors performed the evaluation of the studies and the data extraction. All studies for this review were selected following these inclusion criteria: studies written in English, studies available in full text and studies published in peer-reviewed journal. Molecular biology, identifying cell membrane receptors and pathways involved in bone healing, and studying PEMFs target of action are giving a solid basis for clinical applications of PEMFs. However, further biology studies and clinical trials with clear and standardized parameters (intensity, frequency, dose, duration, type of coil) are required to clarify the precise dose-response relationship and to understand the real applications in clinical practice of PEMFs.     

Biomarkers for Ehlers-Danlos Syndromes: There Is a Role?

Ehlers-Danlos syndromes (EDS) are an inherited heterogeneous group of connective tissue disorders characterized by an abnormal collagen synthesis affecting skin, ligaments, joints, blood vessels, and other organs. It is one of the oldest known causes of bruising and bleeding, and it was described first by Hippocrates in 400 BC. In the last years, multiple gene variants involved in the pathogenesis of specific EDS subtypes have been identified; moreover, new clinical diagnostic criteria have been established. New classification models have also been studied in order to differentiate overlapping conditions. Moreover, EDS shares many characteristics with other similar disorders. Although distinguishing between these seemingly identical conditions is difficult, it is essential in ensuring proper patient care. Currently, there are many genetic and molecular studies underway to clarify the etiology of some variants of EDS. However, the genetic basis of the hypermobile type of EDS (hEDS) is still unknown. In this review, we focused on the study of two of the most common forms of EDS—classic and hypermobile—by trying to identify possible biomarkers that could be of great help to confirm patients’ diagnosis and their follow up.     

Electron microscopic observation of photoreceptor cells in directly inserted anesthetized Drosophila into a high‐pressure freezing unit

The high‐pressure freezing (HPF) technique is known to cryofix water‐containing materials with little ice‐crystal formation in deep depths compared with other freezing techniques. In this study, HPF for anesthetized living Drosophila was performed by placing them directly on the carrier of the HPF unit and exposing them to light. Frozen Drosophila were freeze substituted, and their compound eyes were examined by transmission electron microscopy. The ultrastructures of ommatidia composed of photoreceptor cells were well preserved. The location of the cytoplasmic organelles inside the photoreceptor cells was observed. In some photoreceptor cells in ommatidia of the light‐exposed Drosphila, the cytoplasmic small granules were localized nearer the base of rhabdomeres, compared with those of the nonlight‐exposed Drosophila. Thus, HPF with the direct insertion of living Drosophila under light exposure into the HPF machine enabled us to examine changes to functional structures of photoreceptor cells that occur within seconds.     

Dietary PlsEtn Ameliorates Colon Mucosa Inflammatory Stress and ACF in DMH-Induced Colon Carcinogenesis Mice: Protective Role of Vinyl Ether Linkage

Ethanolamine plasmalogen (PlsEtn), a sub-class of ethanolamine glycerophospholipids (EtnGpl), is a universal phospholipid in mammalian membranes. Several researchers are interested in the relationship between colon carcinogenesis and colon PlsEtn levels. Here, we evaluated the functional role of dietary purified EtnGpl from the ascidian muscle (87.3 mol% PlsEtn in EtnGpl) and porcine liver (7.2 mol% PlsEtn in EtnGpl) in 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) in vivo, and elucidated the possible underlying mechanisms behind it. Dietary EtnGpl-suppressed DMH-induced aberrant crypt with one foci (AC1) and total ACF formation (P < 0.05). ACF suppression by dietary ascidian muscle EtnGpl was higher compared with dietary porcine liver EtnGpl. Additionally, dietary EtnGpl decreased DMH-induced oxidative damage, overproduction of TNF-α, and expression of apoptosis-related proteins in the colon mucosa. The effect of dietary ascidian muscle EtnGpl showed superiority compared with dietary porcine liver EtnGpl. Our results demonstrate the mechanisms by which dietary PlsEtn suppress ACF formation and apoptosis. Dietary PlsEtn attained this suppression by reducing colon inflammation and oxidative stress hence a reduction in DMH-induced intestinal impairment. These findings provide new insights about the functional role of dietary PlsEtn during colon carcinogenesis.     

Hydrolytic Degradation and Morphological Characterization of Electrospun Poly(glycolic acid) [PGA] Thin Films of Different Molecular Weights Containing TiO<Subscript>2</Subscript> Nanoparticles

Thin films of polyglycolic acid (PGA), a biodegradable and biocompatible polymer, were prepared by electrospinning and were studied according to their molecular weights. TiO₂ nanoparticles were also used as additives at concentrations of 2–8 wt%. The films were morphologically characterized and exhibited a homogeneous distribution of TiO₂ with only slight differences depending on the molecular weight. In particular, fibers with low-molecular-weight PGA were thinner and had an average diameter of 77 nm. Furthermore, they showed a higher resolution of the TiO₂ crystal planes regardless of the crystal habit involved. During the melting of the PGA fibers, one single and prominent melting endotherm was observed, which was independent of molecular weight, TiO₂ content, and crystal phase involved. This was in contrast to quiescent PGA crystallization and melting, during which the typical double melting behavior was present. After thermal measurements, TiO₂ did not show characteristics of a nucleating agent for the PGA fibers. However, it acted as a degradation retardant for low-molecular-weight PGA. Because of its hygroscopicity, anatase, a material with the ability to absorb water, was a more efficient hydrolytic degrader than rutile.     

Occurrence of extended-spectrum β-lactamases among isolates of Salmonella enterica subsp. enterica from food-producing animals and food products,in Portugal

A total of 1120 Salmonella spp. isolates, recovered from poultry, swine and food products of animal origin (bovine, swine and poultry) over the period of 2009–2011, were investigated in order to determine their serotype, susceptibility to a panel of eleven antimicrobials (A, ampicillin; Ct, cefotaxime; Cp, ciprofloxacin; Tm, trimethoprim; Su, sulfamethoxazole; C, chloramphenicol; S, streptomycin; G, gentamicin; T, tetracycline; NA, nalidixic acid; Fl, florfenicol), and the presence of resistance determinants of extended-spectrum cephalosporins. Overall, Salmonella Enteritidis was the most common serotype in all three animal species. In 618 isolates of poultry, 32.8% comprised S. Enteritidis, 18.3% Salmonella Havana and 16.5% Salmonella Mbandaka; in 101 isolates of pigs, 21.8% comprised Salmonella Rissen and Salmonella Typhimurium, 10.9% Salmonella Derby and Salmonella London. Salmonella I 4,[5],12:i:- was the most common serotype recovered from pork and beef food products comprising 32.6% and 30% of isolates respectively, followed by S. Rissen (26% and 24%) and S. Typhimurium (18.2% and 19%), respectively. In poultry products, S. Enteritidis was the most frequent serotype (62.7%), followed by S. Mbandaka (10.2%) and S. Derby (8.5%). Susceptibility profiles differed according to the origin of the isolates. Five multidrug resistant isolates (0.45%) were further characterized as extended-spectrum β-lactamase (ESBL) producers. Polymerase chain reaction and sequencing of the amplicons confirmed the presence of bla_CTX-M-1 (n = 2), bla_CTX-M-14 (n = 1), bla_CTX-M-15 (n = 1) and bla_CTX-M-32 (n = 1); bla_SHV-12 and bla_TEM-1 genes were also detected in two isolates of S. I 4,[5],12:i:-. Four isolates, two S. Havana and two S. I 4,[5],12:i:-, carried class 1 integrons and in three, two S. I 4,[5],12:i:- and one S. Havana, ISEcp1 was identified associated to bla_CTX-M-1, bla_CTX-M-32 and bla_CTX-M-14 genes. Additionally, in one S. I 4,[5],12:i:- isolate, orf477 was identified linked to bla_CTX-M-32. No plasmid mediated quinolone resistance-encoding genes were detected. Here, we report for the first time the presence of bla_CTX-M genes in Salmonella enterica subsp enterica isolates recovered from poultry and food products of swine origin, in Portugal.