Genomic and toxigenic heterogeneity of bacillus cereus sensu lato Isolated from ready-to-eat foods and powdered milk in day care centers in Colombia

Bacillus cereus sensu lato (s.l.) is a group of bacteria commonly found in diverse environments, including foods, with potential to cause emesis and diarrhea. In Colombia, it is one of the main foodborne pathogens. The aim of this study was to determine the genomic and toxigenic heterogeneity of B. cereus s.l. isolated from ready-to-eat foods and powdered milk collected in day care centers of Medellin, Colombia. Of 112 B. cereus s.l. isolates obtained, 94% were beta-hemolytic. Toxigenic heterogeneity was established by the presence of nheABC, hblCDAB, cytK2, entFM, and cesB toxigenic genes. The nheABC operon and entFM gene were most frequently detected in the isolates, whereas the cesB gene was not found. According to the toxin genes content, nine toxigenic profiles were identified. A 44% of isolates had profiles with all genes for nonhemolytic enterotoxin, hemolysin BL, and enterotoxin FM production (profiles II and IV). Pulsed-field gel electrophoresis analysis indicated a high genomic heterogeneity among the B. cereus s.l., with 68 isolates grouping into 16 clusters and 33 placed separately in the dendrogram. This study provides useful information on the safety of ready-to-eat foods and powdered milk in day care centers where children, a susceptible population, are exposed and it should incentive for more studies to understand the distribution of different toxin-encoding genes among B. cereus s.l. isolates, enabling detailed risk assessment

Melatonin for a Healthy Heart Rhythm

Melatonin is a promising cardioprotective agent. Its increase during the night is associated with healthy cardiovascular function. On the other hand, reduced levels of melatonin are related to diseases. Aging and chronodisruptors reduce melatonin levels. Pharmacological supplementation reduces the deleterious effects of cardiovascular risk factors and improves the myocardial response to ischemia/reperfusion injury and other proarrhythmic conditions. The protective mechanisms of melatonin involve its antioxidant properties as well as receptor-mediated actions. Signaling pathways include membrane responses, cytoplasmic modulation of kinases, nuclear receptor interactions, and improvement of mitochondrial functions. This chapter focuses on the electrophysiological and the antiarrhythmic properties of melatonin. The acute and chronic protective mechanisms of melatonin will be analyzed with an emphasis on transmembrane potentials and intercellular communication. An outstanding antifibrillatory effect makes melatonin a novel antiarrhythmic agent worthy of further exploration in the path to clinical applications

Métodos no destructivos para la determinación de firmeza. Sensores de Aceleración. Impactadores.

Impact techniques can be used to evaluate firmness on fruit. Chen and Ruiz-Altisent developed and used a 50,4 g impactor with a 19 mm diameter spherical tip, dropping from different heights onto the fruit. Another impactor device is a semispherical impacting tip attached to the end of a pivoting arm. In both devices a small accelerometer is mounted behind the impacting tip. Prototype lateral impactor on-line sorting system for high-speed firmness sorting of fruits has been developed and tested. Preliminary results shows that is possible its use on-line. The last version of an impact device has new elements that improve the data resolution, the signal-noise ratio and the precision

Neither is the man a machine nor is health a commodity. Psychosocial risks of working in the metalliferous mining sector

El trabajo puede llegar a ser fuente de satisfacciones y también de sufrimientos, dependiendo del contenido y la organización del modo de producción imperante. Sus características protegen o exponen a ciertos riesgos psicosociales en el ámbito laboral y es propósito de este artículo identificar dichos riesgos en la minería metalífera. Para ello, desde una mirada interpretativa, particularmente cualitativa, se toma como estudio de caso a los trabajadores de San Juan, Argentina, en 2019. Como resultado, se detectaron distintos factores que causan riesgos y sus consecuencias sociales y en la salud física y psíquica. Entre ellos, uno de los más importantes es el de la ruptura de los vínculos afectivos de los trabajadores, por ejemplo con sus familias.Work can be a source of satisfaction, but also a cause of suffering. According to some theorist’s expert on the topic, this depends on the content and the organization of the dominant production method. Its characteristics provide either protection or exposure to psychosocial risks in the workplace, thus it is the purpose of this paper to identify such risks in the metalliferous mining sector. To that end, and from an interpretative viewpoint, specifically a qualitative one, we took as a case study people working in San Juan, Argentina, in the year 2019. The study detected various factors causing risks and their social consequences, as well as their effects on physical and mental health, the most important being the breaking of employees’ emotional bonds, such as family ones

New version of a laboratory impact device for firmness sensing of fruits.

Results of previous studies conducted by different researchers have shown that impact techniques can be used to evaluate firmness (Delwiche et al., 1989; Delwiche et al.;1996; Jaren et al., 1992; Ruiz Altisent et al., 1996). To impact the fruit with a small spherical impactor of known mass and radius of curvature and measure the acceleration of the impactor is a technique described by Chen et al. (1985) and used by several researchers for sensing fruit firmness (Jaren et al., 1992; Correa et al.; 1992). The advantages of this method vs. a force sensor that measures the force as a function of time is that the measured impact-acceleration response is independent of the fruit mass and is less sensitive to the variation in the radius of curvature of the fruit (Chen et al., 1996). Ruiz Altisent et al. (1993) developed and used a 50 g impactor with a 19 mm diameter spherical tip, dropping from different height for fruits (apples, pears, avocados, melons, peaches ...). Another impact device for firmness sensing of fruits was developed by Chen and Ruiz Altisent (1996). They designed and fabricated an experimental low-mass impact sensor for high-speed sensing of fruit firmness. The impactor consisted of a semi-spherical impacting tip attached to the end (near the centre of percussion) of a pivoting arm. Impact is done by swinging the impactor to collide with the fruit. It has been implemented for on-line use. In both devices a small accelerometer is mounted behind the impacting tip. Lateral impactor and vertical impactor have been used in laboratory and the results from non-destructive impact tests have contributed to standardise methods to measure fruit firmness: Barreiro (1992) compared impact parameters and results of Magness-Taylor penetration tests for apples, pears, apricots [and peaches; Agulheiro (1994) studied the behaviour of the impact parameters during seven weeks of cold storage of two melon varieties; Ortiz (1998) used low energy impact and NIR procedures to segregate non crispy, non firm and soft peaches. Steinmetz (1996) compared various non-destructive firmness sensors, based on sound, impact and micro-deformation

Dispositivo impactador de laboratorio para la determinación de la firmeza en fruta: una nueva versión.

Se ha desarrollado una nueva versión de un dispositivo impactador para obtener un sistema versátil y de fácil manejo. La resolución, la precisión y la relación señal-ruido son mayores en el nuevo sistema que en prototipos anteriores. Se ha realizado un diseño de experimentos con diferentes materiales usando el nuevo y el antiguo impactador para comprobar las mejoras conseguidas

Fine Mapping of Gene Regions Regulating Neurodegeneration

Loss of nerve cells and axons is a common feature of common complex neurodegenerative disorders, such as Alzheimer’s and Parkinson’s diseases. However, also Multiple Sclerosis (MS), primarily an autoimmune disorder, has a prominent neurodegenerative component. In complex disorders, many components affecting disease development and disease progression in combination make up the overall risk. In general, we divide these factors into inherited genetic factors and environmental factors. In addition, there are sometimes complex gene-environment interactions that make it difficult to identify individual risk components. In this thesis, I have focused on a translational approach to find genetic determinants of nerve cell survival in a simplified experimental model of nerve injury-induced neurodegeneration. The aim has been to find novel genes/pathways whose relevance subsequently can be tested in human disease. Through various genetic mapping approaches I demonstrate a strong inverse correlation between neuronal survival and expression and protein levels of an enzyme involved in detoxification of certain oxidation by-products. This enzyme, Glutathione S-Transferase alpha 4 (Gsta4), is highly efficient in catalysing the reduction of the neurotoxic aldehyde 4- hydroxynonenal (HNE), which is generated during lipid peroxidation and has previously been implicated in the pathogenesis of various neurodegenerative disorders. The relevance of this mechanism was also tested in a model of traumatic brain injury, where Gsta4 levels inversely correlate with degree of neuronal loss as well. In addition, rats with higher Gsta4 levels have a more favourable outcome after injection of HNE directly into the cortex. Taken together, these two studies provide strong support for the notion that the identified pathway is highly important for ability to cope with oxidative stress and in turn of relevance for nerve cell survival in different types of acute injury. Finally, a possible role for Gsta4 is tested in experimental autoimmune encephalomyelitis (EAE), a model of MS. No discernible clinical effect was observed between congenic rats with higher Gsta4 expression and the parental strain. However, lower Gsta4 expression was associated with a stronger autoantibody response. Protein modifications by HNE have in other inflammatory models been documented to induce a stronger antibody response, which is consistent with the obtained results. Intrathecal antibody production is an important diagnostic marker in MS, and hypothetically the HNE pathway can play a role for disease course through both neurotoxicity and amplification of the immune response. This was tested in a large case control cohort of MS, where suggested associations both to clinical and immune phenotypes were found. In summary, the results presented encourage further studies on the Gsta4-HNE pathway both in conditions of acute nerve injury and autoimmune neuroinflammation

New proposal involving nanoformulated melatonin targeted to the mitochondria as a potential COVID-19 treatment

Melatonin may be a powerful auxiliary therapy in the prevention and treatment of viral infections, such as coronavirus disease 2019 (COVID-19). Casually, the so-called ‘super immunity’ of bats and the usually high levels of melatonin in children could contribute to their high resistance to the SARS-CoV-2 virus. Melatonin seems to play a key role in suppressing COVID-19 infections. This endogenous antioxidant inhibits cell apoptosis, blocks the inflammasomes that mediate lung inflammation, reduces blood vessel permeability which limits alveolar edema, improves anxiety and sleeps habits that stimulate general immunity and prevents lung fibrosis. These complications, which are usually the main consequences of COVID-19, may be significantly attenuated by melatonin...Fil: Martín Giménez, Virna Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Católica de Cuyo. Facultad de Ciencias Químicas y Tecnológicas; ArgentinaFil: Prado, Natalia Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de Patología; ArgentinaFil: Diez, Emiliano Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Fisiología; ArgentinaFil: Manucha, Walter Ariel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Fisiología; ArgentinaFil: Reiter, Russel. University of Texas at San Antonio; Estados Unido

Morphological characterization of intra-articular HMGB1 expression during the course of collagen-induced arthritis

High-mobility group chromosomal box protein 1 (HMGB1) is a structural nuclear protein that promotes inflammation when present extracellularly. Aberrant, extracellular HMGB1 expression has been demonstrated in human and experimental synovitis. The aim of the present study was to elucidate the temporal and spatial expression of HMGB1 compared to that of the central mediators tumor necrosis factor (TNF) and interleukin-1-beta (IL-1β) during the course of collagen-induced arthritis. Thus, Dark Agouti rats were immunized with homologous type II collagen and synovial tissue specimens were obtained at various time points prior to and during the course of clinical arthritis. Local cytokine responses were assessed by immunohistochemistry and by in situ hybridization. We demonstrate a distinct nuclear expression of HMGB1 at early disease-preceding time points. Preceding clinical onset by a few days, cytoplasmic HMGB1 expression was evident in synoviocytes within the non-proliferative lining layer. Pronounced cytoplasmic and additional extracellular HMGB1 expression coincided with the progression of clinical disease. In advanced arthritis, the number of cells with cytoplasmic HMGB1 expression was quantitatively comparable to that of cells expressing TNF and IL-1β. Interestingly, although HMGB1 was abundantly expressed throughout the inflamed synovium at a protein level, upregulation of HMGB1 mRNA was restricted mainly to areas of cartilage and bone destruction. In conclusion, these new findings implicate a role for HMGB1 in both inducing and perpetuating inflammatory events of significant importance in the destructive processes in chronic arthritis