The emergence of international food safety standards and guidelines: understanding the current landscape through a historical approach

Following the Second World War, the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) teamed up to construct an International Codex Alimentarius (or 'food code') which emerged in 1963. The Codex Committee on Food Hygiene (CCFH) was charged with the task of developing microbial hygiene standards, although it found itself embroiled in debate with the WHO over the nature these standards should take. The WHO was increasingly relying upon the input of biometricians and especially the International Commission on Microbial Specifications for Foods (ICMSF) which had developed statistical sampling plans for determining the microbial counts in the final end products. The CCFH, however, was initially more focused on a qualitative approach which looked at the entire food production system and developed codes of practice as well as more descriptive end-product specifications which the WHO argued were 'not scientifically correct'. Drawing upon historical archival material (correspondence and reports) from the WHO and FAO, this article examines this debate over microbial hygiene standards and suggests that there are many lessons from history which could shed light upon current debates and efforts in international food safety management systems and approaches

The Ctf18 RFC-like complex positions yeast telomeres but does not specify their replication time

Peer reviewedPreprin

Fungal iron availability during deep seated candidiasis is defined by a complex interplay involving systemic and local events

Peer reviewedPublisher PD

On the Use of Gene Ontology Annotations to Assess Functional Similarity among Orthologs and Paralogs: A Short Report

A recent paper (Nehrt et al., PLoS Comput. Biol. 7:e1002073, 2011) has proposed a metric for the “functional similarity” between two genes that uses only the Gene Ontology (GO) annotations directly derived from published experimental results. Applying this metric, the authors concluded that paralogous genes within the mouse genome or the human genome are more functionally similar on average than orthologous genes between these genomes, an unexpected result with broad implications if true. We suggest, based on both theoretical and empirical considerations, that this proposed metric should not be interpreted as a functional similarity, and therefore cannot be used to support any conclusions about the “ortholog conjecture” (or, more properly, the “ortholog functional conservation hypothesis”). First, we reexamine the case studies presented by Nehrt et al. as examples of orthologs with divergent functions, and come to a very different conclusion: they actually exemplify how GO annotations for orthologous genes provide complementary information about conserved biological functions. We then show that there is a global ascertainment bias in the experiment-based GO annotations for human and mouse genes: particular types of experiments tend to be performed in different model organisms. We conclude that the reported statistical differences in annotations between pairs of orthologous genes do not reflect differences in biological function, but rather complementarity in experimental approaches. Our results underscore two general considerations for researchers proposing novel types of analysis based on the GO: 1) that GO annotations are often incomplete, potentially in a biased manner, and subject to an “open world assumption” (absence of an annotation does not imply absence of a function), and 2) that conclusions drawn from a novel, large-scale GO analysis should whenever possible be supported by careful, in-depth examination of examples, to help ensure the conclusions have a justifiable biological basis

Polysomnographic evaluation of obstructive sleep apnea syndrome in children, before and after adenotonsillectomy

Introduction: In the last years the Obstructive Sleep Apnea/Hypopnea Syndrome (OSAHS) has much interested because it has not been completed established. Many criteria defined for OSAS in adults and children are different. We know that patient's clinical story is not sufficient for the diagnosis of OSAHS. In childhood, the most common cause of OSAHS is adenotonsillar hypertrophy, clinically characterised by snoring, apnea episodes, restless sleep, mouth breathing and daytime somnolence. Aim: This study has the purpose of comprovating, by objective way, the OSAS improving in children who underwent adenotonsillectomy. Study design: Clinical prospective. Material and method: For that, 23 children, among 2 and 13 years old, with adenotonsillar hypertrophy, were analysed. After endoscopy and polysomnography, they were submitted to adenotonsillectomy. Results: The polysomnography was repeated 2 months after surgery. The polysomnographic findings were compared through statistic study. Conclusion: All the patients had an important improve after adenotonsillectomy. Only two children (8.69%) persisted with light OSAHS, but they had moderate and important OSAHS before. We concluded that OSAHS is a precise indication for adenotonsillectomy in children.Introdução: Nos últimos anos a Síndrome da Apnéia/Hipopnéia Obstrutiva do Sono (SAHOS) tem despertado muito interesse por tratar-se de uma condição não totalmente estabelecida. Muitos critérios usados para definir SAHOS em adultos e crianças são diferentes entre si. Em 1995 Sabe-se que a história clínica do paciente não era suficiente para estabelecer o diagnóstico de SAHOS. Na criança a causa mais comum de SAOS é a hipertrofia adenoamigdaliana, normalmente caracterizada clinicamente pela presença de roncos noturnos, episódios de apnéia, sono agitado, respiração bucal e hipersonolência diurna4. Objetivo: Este estudo tem o intuito de comprovar de forma objetiva a melhora da SAHOS em crianças submetidas a adenoamigdalectomia. Forma de estudo: Clínico prospectivo. Material e método: Para isso, foram avaliadas 23 crianças entre 2 e 13 anos (1999-2001), com hipertrofia adenoamigdaliana, que após nasofibroscopia e polissonografia foram submetidas a cirurgia de adenoamigdalectomia. A polissonografia foi repetida após 2 meses de pós-operatório. Foi então realizado estudo estatístico dos dados obtidos na polissonografia pré- e pós-operatória. Resultado: Observamos que todos os pacientes tiveram melhora importante após adenoamigdalectomia. Duas crianças (8,69%) persistiram com SAOS leve, que anteriormente eram de grau moderado e acentuado. Conclusão: Concluímos assim que SAOS é uma indicação precisa para cirurgia de adenoamigdalectomia em crianças.UNIFESP-EPM Disciplina de Otorrinolaringologia PediátricaUNIFESP, EPM, Disciplina de Otorrinolaringologia PediátricaSciEL

Magnetism, FeS colloids, and Origins of Life

A number of features of living systems: reversible interactions and weak bonds underlying motor-dynamics; gel-sol transitions; cellular connected fractal organization; asymmetry in interactions and organization; quantum coherent phenomena; to name some, can have a natural accounting via $physical$ interactions, which we therefore seek to incorporate by expanding the horizons of `chemistry-only' approaches to the origins of life. It is suggested that the magnetic 'face' of the minerals from the inorganic world, recognized to have played a pivotal role in initiating Life, may throw light on some of these issues. A magnetic environment in the form of rocks in the Hadean Ocean could have enabled the accretion and therefore an ordered confinement of super-paramagnetic colloids within a structured phase. A moderate H-field can help magnetic nano-particles to not only overcome thermal fluctuations but also harness them. Such controlled dynamics brings in the possibility of accessing quantum effects, which together with frustrations in magnetic ordering and hysteresis (a natural mechanism for a primitive memory) could throw light on the birth of biological information which, as Abel argues, requires a combination of order and complexity. This scenario gains strength from observations of scale-free framboidal forms of the greigite mineral, with a magnetic basis of assembly. And greigite's metabolic potential plays a key role in the mound scenario of Russell and coworkers-an expansion of which is suggested for including magnetism.Comment: 42 pages, 5 figures, to be published in A.R. Memorial volume, Ed Krishnaswami Alladi, Springer 201

Haemodynamic consequences of changing potassium concentrations in haemodialysis fluids

<p>Abstract</p> <p>Background</p> <p>A rapid decrease of serum potassium concentrations during haemodialysis produces a significant increase in blood pressure parameters at the end of the session, even if effects on intra-dialysis pressure are not seen. Paradoxically, in animal models potassium is a vasodilator and decreases myocardial contractility. The purpose of this trial is to study the precise haemodynamic consequences induced by acute changes in potassium concentration during haemodialysis.</p> <p>Methods</p> <p>In 24 patients, 288 dialysis sessions, using a randomised single blind crossover design, we compared six dialysate sequences with different potassium profiles. The dialysis sessions were divided into 3 tertiles, casually modulating potassium concentration in the dialysate between the value normally used K and the two cut-off points K+1 and K-1 mmol/l. Haemodynamics were evaluated in a non-invasive manner using a finger beat-to-beat monitor.</p> <p>Results</p> <p>Comparing K-1 and K+1, differences were found within the tertiles regarding systolic (+5.3, +6.6, +2.3 mmHg, p < 0.05, < 0.05, ns) and mean blood pressure (+4.3, +6.4, -0.5 mmHg, p < 0.01, < 0.01, ns), as well as peripheral resistance (+212, +253, -4 dyne.sec.cm^-5, p < 0.05, < 0.05, ns). The stroke volume showed a non-statistically-significant inverse trend (-3.1, -5.2, -0.2 ml). 18 hypotension episodes were recorded during the course of the study. 72% with K-1, 11% with K and 17% with K+1 (p < 0.01 for comparison K-1 vs. K and K-1 vs. K+1).</p> <p>Conclusions</p> <p>A rapid decrease in the concentration of serum potassium during the initial stage of the dialysis-obtained by reducing the concentration of potassium in the dialysate-translated into a decrease of systolic and mean blood pressure mediated by a decrease in peripheral resistance. The risk of intra-dialysis hypotension inversely correlates to the potassium concentration in the dialysate.</p> <p>Trial Registration Number</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01224314">NCT01224314</a></p