Efecto de diámetro de esfera y densidad celular en la producción de etanol con levadura inmovilizada en alginato

Effect of pellet diameter and cell density on ethanol production with alginate immobilized yeast Título corto: Producción de etanol con levadura inmovilizada ResumenLas células inmovilizadas tienen aplicación potencial en la producción de biocombustibles posibilitando la reutilización de biomasa, el empleo de diversas configuraciones de reactores y sistemas de cultivo, el manejo de altas densidades celulares alcanzando altas productividades volumétricas, y la simplificación de operaciones de procesamiento de salida. El objetivo del presente estudio fue evaluar la influencia del diámetro de las perlas y la densidad celular en la producción de etanol con Saccharomyces uvarum inmovilizada en alginato al 2% (p/v). Para ello se evaluaron tres diámetros de perlas de 2, 2,5 y 3 mm. Las células inmovilizadas fueron cultivadas en medio con 12% (p/v) de glucosa en biorreactores de columna sin agitación a 28 ºC, y se operaron cuatro lotes consecutivos de 48 horas cada uno. En cada lote se cuantificó el consumo de glucosa y se determinó la cantidad de etanol producido. Los rendimientos máximos de etanol para las esferas de 2, 2,5 y 3 mm de diámetro fueron 81, 83 y 97% del rendimiento teórico. La máxima productividad volumétrica de etanol fue 1,2 g/L-1/h-1 con un consumo de glucosa de 99,8% al término del lote, correspondiente a las columnas con perlas de 3 mm y con una producción de 0,017 g de etanol por esfera. La producción de etanol acumulada en cada sistema fue 178, 189 y 200 g/L-1 para 2, 2,5 y 3 mm respectivamente, encontrándose una relación directa con el diámetro de perla e inversa respecto a la densidad celular. Los rendimientos de etanol obtenidos son superiores a los reportados para la misma especie. Palabras clave: inmovilización, alginato, Saccharomyces uvarum, etanol, lote repetido.AbstractImmobilized cells have a potential use in biofuel production. They also allow re-using biomass, using diverse reactor configurations and culture systems, handling high cell densities to obtain high volumetric productivities and to simplify the downstream processing. The purpose of this work was to evaluate the influence of bead diameter and cell density on ethanol production using immobilized Saccharomyces uvarum in 2% (w/v) alginate. For that, three bead diameters (2, 2.5 and 3 mm) were evaluated. Immobilized cells were cultured on a 12% (w/v) glucose medium in column bioreactors without agitation at 28 °C for four 48 h–repeated batches. For each batch, both glucose consumption and ethanol produced were measured. Maximum yields for 2, 2.5 and 3 mm bead diameters were 81, 83 and 97% of theoretical yield. Maximum volumetric productivity of ethanol was 1.2 g/L-1/h-1 with 99.8% glucose consumption at the end of the batch, corresponding to the 3 mm bead diameter and the ethanol production per bead was 0.017 g. Accumulated ethanol production for each system was 178, 189 and 200 g/L-1 for 2, 2.5 y 3 mm bead diameter, respectively, being this directly related to bead diameter and inversely related to cell density. Ethanol yields were higher than those reported for the same species.Key words: Immobilization, alginate, Saccharomyces uvarum, ethanol, repeated batch

Brexit’s Effect on Citizens, Human Rights & Immigration

This report records the roundtable on “Brexit’s Effect on Citizens, Human Rights and Immigration” organised by Dr Adrienne Yong on 11 June 2019 at City, University of London funded by the Higher Education Innovation Fund (HEIF) 2018/19. Speakers included: • Hannah Wilkins (House of Commons Library) • Blanca Grey (Home Office)1 • Paul Erdunast (Immigration Law Practitioner’s Association - ILPA) • Christopher Desira (Seraphus Solicitors) • Nicole Masri (Rights of Women) • Ollie Persey (Public Law Project) • Katarzyna Zagrodniczek (East European Resource Centre) • Mihai Calin Bica (Roma Support Group) • Dr Adrienne Yong (City, University of London) • Dr Michaela Benson (Goldsmiths, University of London) • Madeleine Sumption (Migration Observatory) • Sheona York (Kent Law Clinic) A host of unique legal questions were raised in the aftermath of the UK’s referendum result where the electorate voted in favour of leaving the EU on the 23 June 2016. Opinion has been split as to whether the UK and EU have indeed struck a fair deal for citizens, with arguments that citizens have been used as bargaining chips throughout the process to achieve a deal. As negotiations progressed towards the original mandated date of withdrawal, 29 March 2019, various schemes emerged to handle post-Brexit immigration of EU citizens in the UK and reciprocal arrangements for British citizens in the EU. This is now reflected in the EU Settlement Scheme, the Immigration and Social Security Co-ordination Bill, and the reciprocity agreed with EU Member States as to British citizens in the EU. These issues and more were discussed at the roundtable

Clinical relevance of biomarkers of oxidative stress

SIGNIFICANCE Oxidative stress is considered to be an important component of various diseases. A vast number of methods have been developed and used in virtually all diseases to measure the extent and nature of oxidative stress, ranging from oxidation of DNA to proteins, lipids, and free amino acids. Recent Advances: An increased understanding of the biology behind diseases and redox biology has led to more specific and sensitive tools to measure oxidative stress markers, which are very diverse and sometimes very low in abundance. CRITICAL ISSUES The literature is very heterogeneous. It is often difficult to draw general conclusions on the significance of oxidative stress biomarkers, as only in a limited proportion of diseases have a range of different biomarkers been used, and different biomarkers have been used to study different diseases. In addition, biomarkers are often measured using nonspecific methods, while specific methodologies are often too sophisticated or laborious for routine clinical use. FUTURE DIRECTIONS Several markers of oxidative stress still represent a viable biomarker opportunity for clinical use. However, positive findings with currently used biomarkers still need to be validated in larger sample sizes and compared with current clinical standards to establish them as clinical diagnostics. It is important to realize that oxidative stress is a nuanced phenomenon that is difficult to characterize, and one biomarker is not necessarily better than others. The vast diversity in oxidative stress between diseases and conditions has to be taken into account when selecting the most appropriate biomarker. Antioxid. Redox Signal. 00, 000-000

ADAPT Identifies an ESCRT Complex Composition That Discriminates VCaP From LNCaP Prostate Cancer Cell Exosomes

Libraries of single-stranded oligodeoxynucleotides (ssODNs) can be enriched for sequences that specifically bind molecules on naïve complex biological samples like cells or tissues. Depending on the enrichment strategy, the ssODNs can identify molecules specifically associated with a defined biological condition, for example a pathological phenotype, and thus are potentially useful for biomarker discovery. We performed ADAPT, a variant of SELEX, on exosomes secreted by VCaP prostate cancer cells. A library of ∼1011 ssODNs was enriched for those that bind to VCaP exosomes and discriminate them from exosomes derived from LNCaP prostate cancer cells. Next-generation sequencing (NGS) identified the best discriminating ssODNs, nine of which were resynthesized and their discriminatory ability confirmed by qPCR. Affinity purification with one of the sequences (Sequence 7) combined with LC-MS/MS identified its molecular target complex, whereof most proteins are part of or associated with the multiprotein ESCRT complex participating in exosome biogenesis. Within this complex, YBX1 was identified as the directly-bound target protein. ADAPT thus is able to differentiate exosomes from cancer cell subtypes from the same lineage. The composition of ESCRT complexes in exosomes from VCaP versus LNCaP cells might constitute a discriminatory element between these prostate cancer subtypes

Mapping of hormones and cortisol responses in patients after Lyme neuroborreliosis

<p>Abstract</p> <p>Background</p> <p>Persistent symptoms after treatment for neuroborreliosis are common for reasons mainly unknown. These symptoms are often unspecific and could be caused by dysfunctions in endocrine systems, an issue that has not been previously addressed systematically. We therefore mapped hormone levels in patients with previous confirmed Lyme neuroborreliosis of different outcomes and compared them with a healthy control group.</p> <p>Methods</p> <p>Twenty patients of a retrospective cohort of patients treated for definite Lyme neuroborreliosis were recruited 2.3 to 3.7 years (median 2.7) after diagnosis, together with 23 healthy controls. Lyme neuroborreliosis patients were stratified into two groups according to a symptom/sign score. All participants underwent anthropometric and physiological investigation as well as an extensive biochemical endocrine investigation including a short high-dose adrenocorticotropic hormone stimulation (Synacthen^®) test. In addition to hormonal status, we also examined electrolytes, 25-hydroxy-vitamin D and interleukin-6.</p> <p>Results</p> <p>Eight patients (40%) had pronounced symptoms 2-3 years after treatment. This group had a higher cortisol response to synacthen as compared with both controls and the Lyme neuroborreliosis patients without remaining symptoms (p < 0.001 for both comparisons). No other significant differences in the various baseline biochemical parameters, anthropometric or physiological data could be detected across groups.</p> <p>Conclusions</p> <p>Apart from a positive association between the occurrence of long-lasting complaints after Lyme neuroborreliosis and cortisol response to synacthen, no corticotropic insufficiency or other serious hormonal dysfunction was found to be associated with remaining symptoms after treatment for Lyme neuroborreliosis.</p

Post-graduation migration intentions of students of Lebanese medical schools: a survey study

<p>Abstract</p> <p>Background</p> <p>The international migration of physicians is a global public health problem. Lebanon is a source country with the highest emigration factor in the Middle East and North Africa and the 7th highest in the World. Given that residency training abroad is a critical step in the migration of physicians, the objective of this study was to survey students of Lebanese medical schools about their intentions to train abroad and their post training plans.</p> <p>Methods</p> <p>Our target population consisted of all students of Lebanese medical schools in the pre-final and final years of medical school. We developed the survey questionnaire based on the results of a qualitative study assessing the intentions and motives for students of Lebanese medical schools to train abroad. The questionnaire inquired about student's demographic and educational characteristics, intention to train abroad, the chosen country of abroad training, and post-training intention of returning to Lebanon.</p> <p>Results</p> <p>Of 576 eligible students, 425 participated (73.8% response rate). 406 (95.5%) respondents intended to travel abroad either for specialty training (330 (77.6%)) or subspecialty training (76 (17.9%)). Intention to train abroad was associated with being single compared with being married. The top 4 destination countries were the US (301(74.1%)), France (49 (12.1%)), the United Kingdom (31 (7.6%)) and Canada (17 (4.2%)). One hundred and two (25.1%) respondents intended to return to Lebanon directly after finishing training abroad; 259 (63.8%) intended to return to Lebanon after working abroad temporarily for a varying number or years; 43 (10.6%) intended to never return to Lebanon. The intention to stay indefinitely abroad was associated male sex and having a 2^ndcitizenship. It was inversely associated with being a student of one of the French affiliated medical schools and a plan to train in a surgical specialty.</p> <p>Conclusion</p> <p>An alarming percentage of students of Lebanese medical schools intend to migrate for post graduate training, mainly to the US. A minority intends to return directly to Lebanon after finishing training abroad.</p

Investigating the Role of Islet Cytoarchitecture in Its Oscillation Using a New β-Cell Cluster Model

The oscillatory insulin release is fundamental to normal glycemic control. The basis of the oscillation is the intercellular coupling and bursting synchronization of β cells in each islet. The functional role of islet β cell mass organization with respect to its oscillatory bursting is not well understood. This is of special interest in view of the recent finding of islet cytoarchitectural differences between human and animal models. In this study we developed a new hexagonal closest packing (HCP) cell cluster model. The model captures more accurately the real islet cell organization than the simple cubic packing (SCP) cluster that is conventionally used. Using our new model we investigated the functional characteristics of β-cell clusters, including the fraction of cells able to burst fb, the synchronization index λ of the bursting β cells, the bursting period Tb, the plateau fraction pf, and the amplitude of intracellular calcium oscillation [Ca]. We determined their dependence on cluster architectural parameters including number of cells nβ, number of inter-β cell couplings of each β cell nc, and the coupling strength gc. We found that at low values of nβ, nc and gc, the oscillation regularity improves with their increasing values. This functional gain plateaus around their physiological values in real islets, at nβ∼100, nc∼6 and gc∼200 pS. In addition, normal β-cell clusters are robust against significant perturbation to their architecture, including the presence of non-β cells or dead β cells. In clusters with nβ>∼100, coordinated β-cell bursting can be maintained at up to 70% of β-cell loss, which is consistent with laboratory and clinical findings of islets. Our results suggest that the bursting characteristics of a β-cell cluster depend quantitatively on its architecture in a non-linear fashion. These findings are important to understand the islet bursting phenomenon and the regulation of insulin secretion, under both physiological and pathological conditions

Effect of oat bran on time to exhaustion, glycogen content and serum cytokine profile following exhaustive exercise

The aim of this study was to evaluate the effect of oat bran supplementation on time to exhaustion, glycogen stores and cytokines in rats submitted to training. The animals were divided into 3 groups: sedentary control group (C), an exercise group that received a control chow (EX) and an exercise group that received a chow supplemented with oat bran (EX-O). Exercised groups were submitted to an eight weeks swimming training protocol. In the last training session, the animals performed exercise to exhaustion, (e.g. incapable to continue the exercise). After the euthanasia of the animals, blood, muscle and hepatic tissue were collected. Plasma cytokines and corticosterone were evaluated. Glycogen concentrations was measured in the soleus and gastrocnemius muscles, and liver. Glycogen synthetase-α gene expression was evaluated in the soleus muscle. Statistical analysis was performed using a factorial ANOVA. Time to exhaustion of the EX-O group was 20% higher (515 ± 3 minutes) when compared with EX group (425 ± 3 minutes) (p = 0.034). For hepatic glycogen, the EX-O group had a 67% higher concentrations when compared with EX (p = 0.022). In the soleus muscle, EX-O group presented a 59.4% higher glycogen concentrations when compared with EX group (p = 0.021). TNF-α was decreased, IL-6, IL-10 and corticosterone increased after exercise, and EX-O presented lower levels of IL-6, IL-10 and corticosterone levels in comparison with EX group. It was concluded that the chow rich in oat bran increase muscle and hepatic glycogen concentrations. The higher glycogen storage may improve endurance performance during training and competitions, and a lower post-exercise inflammatory response can accelerate recovery

Viscum album L. extracts in breast and gynaecological cancers: a systematic review of clinical and preclinical research

<p>Abstract</p> <p>Background</p> <p><it>Viscum album </it>L. extracts (VAE, European mistletoe) are a widely used medicinal plant extract in gynaecological and breast-cancer treatment.</p> <p>Methods</p> <p>Systematic review to evaluate clinical studies and preclinical research on the therapeutic effectiveness and biological effects of VAE on gynaecological and breast cancer. Search of databases, reference lists and expert consultations. Criteria-based assessment of methodological study quality.</p> <p>Results</p> <p>19 randomized (RCT), 16 non-randomized (non-RCT) controlled studies, and 11 single-arm cohort studies were identified that investigated VAE treatment of breast or gynaecological cancer. They included 2420, 6399 and 1130 patients respectively. 8 RCTs and 8 non-RCTs were embedded in the same large epidemiological cohort study. 9 RCTs and 13 non-RCTs assessed survival; 12 reported a statistically significant benefit, the others either a trend or no difference. 3 RCTs and 6 non-RCTs assessed tumour behaviour (remission or time to relapse); 3 reported statistically significant benefit, the others either a trend, no difference or mixed results. Quality of life (QoL) and tolerability of chemotherapy, radiotherapy or surgery was assessed in 15 RCTs and 9 non-RCTs. 21 reported a statistically significant positive result, the others either a trend, no difference, or mixed results. Methodological quality of the studies differed substantially; some had major limitations, especially RCTs on survival and tumour behaviour had very small sample sizes. Some recent studies, however, especially on QoL were reasonably well conducted. Single-arm cohort studies investigated tumour behaviour, QoL, pharmacokinetics and safety of VAE. Tumour remission was observed after high dosage and local application. VAE application was well tolerated. 34 animal experiments investigated VAE and isolated or recombinant compounds in various breast and gynaecological cancer models in mice and rats. VAE showed increase of survival and tumour remission especially in mice, while application in rats as well as application of VAE compounds had mixed results. <it>In vitro </it>VAE and its compounds have strong cytotoxic effects on cancer cells.</p> <p>Conclusion</p> <p>VAE shows some positive effects in breast and gynaecological cancer. More research into clinical efficacy is warranted.</p

Zeolite structures loading with an anticancer compound as drug delivery systems

The authors are thankful to Dr. A. S. Azevedo for collecting the powder diffraction data.Two different structures of zeolites, faujasite (FAU) and Linde type A (LTA), were studied to investigate their suitability for drug delivery systems (DDS). The zeolites in the sodium form (NaY and NaA) were used as hosts for encapsulation of α-cyano-4- hydroxycinnamic acid (CHC). CHC, an experimental anticancer drug, was encapsulated in both zeolites by diffusion in liquid phase. These new drug delivery systems, CHC@zeolite, were characterized by spectroscopic techniques (FTIR, 1H NMR, 13C and 27Al solidstate MAS NMR, and UV−vis), chemical analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of the zeolites and CHC@zeolite drug deliveries on HCT-15 human colon carcinoma cell line viability was evaluated. Both zeolites alone revealed no toxicity to HCT-15 cancer cells. Importantly, CHC@zeolite exhibit an inhibition of cell viability up to 585-fold, when compared to the non-encapsulated drug. These results indicate the potential of the zeolites for drug loading and delivery into cancer cells to induce cell deathO.M. and R.A. are recipients of fellowships (SFRH/BD/36463/2007, SFRH/BI/51118/2010) from Fundação para a Ciência e a Tecnologia (FCT, Portugal). This work was supported by the FCT projects refs PEst-C/ QUI/UI0686/2011, PEst-C/CTM/LA0011/2011, and PTDC/ SAU-FCF/104347/2008, under the scope of “Programa Operacional Temático Factores de Competitividade” (COMPETE) of “Quadro Comunitário de Apoio III” and cofinanced by Fundo Comunitário Europeu FEDER, and the Centre of Chemistry and Life and Health Sciences Research Institute (University of Minho, Portugal)