Evaluation of the cancer risk from PAHs by inhalation:Are current methods fit for purpose?

There is ample evidence from occupational studies that exposure to a mixture of Polycyclic Aromatic Hydrocarbons (PAHs) is causally associated with an increased incidence of lung cancers. In both occupational atmospheres and ambient air, PAHs are present as a mixture of many compounds, but the composition of the mixture in ambient air differs from that in the occupational atmosphere, and varies in time and space in ambient air. Estimates of cancer risk for PAH mixtures are based upon unit risks which derive from extrapolation of occupational exposure data or animal model data, and in the case of the WHO use one compound, benzo[a]pyrene as a marker for the entire mixture, irrespective of composition. The U.S. EPA has used an animal exposure study to derive a unit risk for inhalation exposure to benzo[a]pyrene alone, and there have been a number of rankings of relative carcinogenic potency for other PAHs which many studies have used to calculate a cancer risk from the PAHs mixture, frequently incorrectly by adding the estimated relative risks of individual compounds, and applying the total “B[a]P equivalent” to the WHO unit risk, which already applies to the entire mixture. Such studies are often based upon data solely for the historic US EPA group of 16 compounds which do not include many of the apparently more potent carcinogens. There are no data for human cancer risk of individual PAHs, and conflicting evidence of additivity of PAH carcinogenicity in mixtures. This paper finds large divergences between risk estimates deriving from the WHO and U.S. EPA methods, as well as considerable sensitivity to the mixture composition, and assumed PAH relative potencies. Of the two methods, the WHO approach appears more likely to provide reliable risk estimates, but recently proposed mixture-based approaches using in vitro toxicity data may offer some advantages.peer-reviewe

An overview of study designs

The numbers of clinical trials have increased exponentially over the last decade, amplifying the pressure to select an appropriate study design to obtain reliable and valid evidence. The ability to find, critically appraise and use evidence to develop new interventions is fundamental to evidence-based medicine. Different study designs have their own advantages and disadvantages, and provide different evidentiary value. This article provides an overview of clinical trials, illustrating that, ultimately, the study design chosen needs to meet experimental and funding limitations, while minimising error

Evidence for specific subunit distribution and interactions in the quaternary structure of α-crystallin

The quaternary structure of alpha-crystallin is dynamic, a property which has thwarted crystallographic efforts towards structural characterization. In this study, we have used collision-induced dissociation mass spectrometry to examine the architecture of the polydisperse assemblies of alpha-crystallin. For total alpha-crystallin isolated directly from fetal calf lens using size-based chromatography, the alpha B-crystallin subunit was found to be preferentially dissociated from the oligomers, despite being significantly less abundant overall than the alpha A-crystallin subunits. Furthermore, upon mixing molar equivalents of purified alpha A- and alpha B-crystallin, the levels of their dissociation were found to decrease and increase, respectively, with time. Interestingly though, dissociation of subunits from the alpha A- and alpha B-crystallin homo-oligomers was comparable, indicating that strength of the alpha A:alpha A, and alpha B:alpha B subunit interactions are similar. Taken together, these data suggest that the differences in the number of subunit contacts in the mixed assemblies give rise to the disproportionate dissociation of alpha B-crystallin subunits. Limited proteolysis mass spectrometry was also used to examine changes in protease accessibility during subunit exchange. The C-terminus of alpha A-crystallin was more susceptible to proteolytic attack in homo-oligomers than that of aB-crystallin. As subunit exchange proceeded, proteolysis of the alpha A-crystallin C-terminus increased, indicating that in the hetero-oligomeric form this tertiary motif is more exposed to solvent. These data were used to propose a refined arrangement for the interactions of the alpha-crystallin domains and C-terminal extensions of subunits within the alpha-crystallin assembly. In particular, we propose that the palindromic IPI motif of alpha B-crystallin gives rise to two orientations of the C-terminus

HAND HYGIENE KNOWLEDGE, PRACTICE AND FACILITIES UTILIZATION OF PUPILS IN BATANGAS CITY, PHILIPPINES: BASIS FOR PROPOSED HAND HYGIENE ACTIVITIES

This study assessed the hand hygiene knowledge, practice and facilities utilization of pupils in Batangas City, Philippines during academic year 2016-2017. Using a self-structured questionnaire, the researchers selected one thousand one hundred eighteen (1,118) pupils as participants in this research. They analyzed the responses of the pupils through the use of frequency counts, weighted mean, t-test and Analysis of Variance (ANOVA) to determine the difference of responses among grade levels and school type. The study found out school type had the most influence on pupils’ learning concepts about hand hygiene as well as its implementation and the provision of adequate supplies & facilities. Public school pupils showed higher scores in hand hygiene knowledge, practice and facilities utilization as well as greater interest on the proposed hand hygiene activities. These included, among others, conduct of health teaching on proper hand hygiene technique with disease education and preparation of individual hygiene kit for pupils. On the other hand, grade level was determined not to have significant difference on the pupils’ know-how in hand cleansing. This is because regardless of the pupils grade level their knowledge, practice and facilities utilization including interest on the suggested hand hygiene health activities remain the same. It is further recommended that school administrators take action on the pupils’ interest regarding hand hygiene health activities proposed in the study

Percepción y valoración del alumnado sobre las propuestas blearning en grados de ingenierías industriales y de telecomunicación

This study is included in a research project, which has been developed for 3 years (2013-2015) at the Polytechnic University of Catalonia, Terrassa Engineering School (EET), in order to know the uses and pedagogical conceptions with educational proposals, blended learning mode, hosted on the virtual platform Athena, conceived and designed by Moodle, a system for management courses which is freely distributable. The investigation was applied to 7 degree courses in the field of engineering, currently issued by the EET, including 144 subjects, 192 teachers and 1,559 students. The main purpose of the study presented here was to investigate on the assessment made by the students about the courses included on the digital campus referring to two aspects: the usefulness and the use of some tools and the influence of this technology, which contributes to a better learning of the contents of different subjects. Even though this is part of a mixed methodological design, in order to conclude collecting the processed and analyzed information of this study, it was used the questionnaire which had been previously filled in by students. The results have brought us closer to an intense use of the platform as a documentary resource or content repository, activities and access to other types of information, and to be more independent, learn more and a further customization of the learning process. Virtual communication through tools platform is underused and unidirectional, ruining a basic resource to enhance opportunities for coordination, collaboration and knowledge generation between teachers and students.Este estudio se engloba en un proyecto de investigación desarrollado durante 3 años (2013-2015) en la Escuela de Ingeniería de Terrassa (EET), centro perteneciente a la Universidad Politécnica de Cataluña, cuya finalidad es conocer los usos y las concepciones pedagógicas que subyacen a las propuestas docentes, en modalidad blended learning, alojadas en la plataforma virtual Atenea, diseñada bajo el sistema Moodle. La investigación se extendió a las 7 titulaciones de grado del ámbito de las ingenierías actualmente impartidas por la EET, comprendiendo un total de 144 asignaturas, 192 docentes y 1559 discentes. El objetivo del estudio fue indagar sobre la valoración que hace el alumnado de los cursos alojados en el campus digital desde una doble vertiente: la utilidad y el uso de algunas herramientas y el grado en que esta tecnología contribuye a un mejor aprendizaje de los contenidos de las diferentes asignaturas. Partiendo de un diseño metodológico mixto, para recabar la información procesada y analizada en este estudio se recurrió al cuestionario de opinión para el alumnado. Los resultados obtenidos nos acercan a un uso intenso de la plataforma como recurso documental o repositorio de contenidos, actividades y de acceso a otra tipología de información, así como para ser más autónomos, aprender más y tender a una mayor personalización del proceso de aprendizaje. La comunicación virtual mediante herramientas de la plataforma es poco utilizada y unidireccional, malogrando un recurso básico para potenciar espacios de coordinación, colaboración y generación de conocimiento entre profesorado y alumnado

Enforceability of certain commercial contract clauses in terms of Maltese law and a consideration of public policy

The Maltese position regarding commercial clauses is rather ambiguous due to lack of both local legislation and jurisprudence. In today's global economy, with individual shifting from one employment to another at a rate which has never been seen before, when a contract of employment is entered into, there are certain clauses which are increasingly included. This article deals with a couple of such clauses, that is, non-compete clauses, non-solicitation clauses and severability clauses. The aim of these clauses is to create an ambit of fair competition between the contracting parties by striking a balance between the legitimate interests of both. This approach is key in preserving and strengthening trade in general. Despite the vagueness of the Maltese legal order on the topic, latent trends in the Maltese Courts' reasoning when dealing with commercial matters, seem to indicate that our justice system does appreciate the significance of the above-mentioned clauses which is crucial in today's ever-increasing competitive industries. However, it is important to outline that, in principle, for contractual provisions to be enforceable, these should be reasonable in nature and do not breach public policy. Under Maltese law, public policy is still a rather abstract concept, a matter which is dealt with in this article, in an attempt to provide a non-exhaustive collection of principles which appear to constitute public policy according to the Maltese courts.peer-reviewe

Images in Clinical Urology: Complex open pyeloplasty in a pelvic kidney

A pelvic kidney occurs in between 1 in 2200 and 1 in 3000 people,1 due to failure of ascent during development. It is commonly asymptomatic and usually functions normally. Pelvic ureteral junction obstruction can either be congenital or acquired, and is characterized by intrinsic stenosis or extrinsic compression of the ureter at the junction with the pelvicalyceal renal system. This can cause symptomatic or asymptomatic hydronephrosis. We describe the complex case and management of a patient with a massive pelvic ureteral junction obstruction in a pelvic kidney

Neurosurgical experience of managing optic pathway gliomas

Background: Optic pathway gliomas (OPGs), also known as visual pathway gliomas, are debilitating tumors that account for 3–5% of all pediatric brain tumors. They are most commonly WHO grade 1 pilocytic astrocytomas and frequently occur in patients with neurofibromatosis type 1. The location of these tumors results in visual loss and blindness, endocrine and hypothalamic dysfunction, hydrocephalus, and premature death. Their involvement of the visual pathways and proximity to other eloquent brain structures typically precludes complete resection or optimal radiation dosing without incurring significant neurological injury. There are various surgical interventions that can be performed in relation to these lesions including biopsy, cerebrospinal fluid diversion, and partial or radical resection, but their role is a source of debate. This study catalogues our surgical experience and patient outcomes in order to support decision-making in this challenging pathology. Methods: A retrospective review of all cases of OPGs treated in a single center from July 1990 to July 2020. Data was collected on patient demographics, radiographic findings, pathology, and management including surgical interventions. Outcome data included survival, visual function, endocrine, and hypothalamic dysfunction. Results: One hundred twenty-one patients with OPG were identified, and 50 of these patients underwent a total of 104 surgical procedures. These included biopsy (31), subtotal or gross total resection (20 operations in 17 patients), cyst drainage (17), Ommaya reservoir insertion (9), or cerebrospinal fluid diversion (27). During the study period, there was 6% overall mortality, 18% hypothalamic dysfunction, 20% endocrine dysfunction, and 42% had some cognitive dysfunction. At diagnosis 75% of patients had good or moderate visual function in at least one eye, and overall, this improved to 83% at the end of the study period. In comparison the worst eye had good or moderate visual function in 56%, and this reduced to 53%. Baseline and final visual function were poorer in patients who had a surgical resection, but improvements in vision were still found—particularly in the best eye. Discussion/conclusion: OPG are debilitating childhood tumor that have lifelong consequences in terms of visual function and endocrinopathies/hypothalamic dysfunction; this can result in substantial patient morbidity. Decisions regarding management and the role of surgery in this condition are challenging and include cerebrospinal fluid diversion, biopsy, and in highly select cases cystic decompression or surgical resection. In this paper, we review our own experience, outcomes, and surgical philosophy

Transformando la docencia: usos de las plataformas de e-learning en la educación superior presencial

La gran mayoría de Universidades de carácter presencial cuenta con plataformas de e-learning para dar soporte a los procesos de enseñanza y aprendizaje. El propósito de este artículo consiste en mostrar los aspectos más significativos de una investigación desarrollada durante tres años (2013-2015) en una Escuela Superior de Ingeniería y cuyo objetivo es realizar una aproximación al uso tecnológico, pedagógico y comunicativo que subyace en las propuestas docentes mediadas por la plataforma Moodle. Mediante una metodología mixta, cuantitativa y cualitativa, se utilizaron como fuentes de datos un cuestionario destinado al profesorado y la observación periférica de las 144 asignaturas de grado ofrecidas en la Escuela, pertenecientes a 7 titulaciones de Ingenierías Industriales y de Telecomunicación. Los resultados obtenidos nos muestran que, tras más de una década de utilización de la plataforma, existe una buena adecuación tecnológica de las aulas virtuales, una gradual renovación pedagógica de las propuestas docentes y una escasa explotación de las herramientas comunicativas

Transforming teaching: uses of e-learning platforms in face-to-face higher education

La gran mayoría de Universidades de carácter presencial cuenta con plataformas de e-learning para dar soporte a los procesos de enseñanza y aprendizaje. El propósito de este artículo consiste en mostrar los aspectos más significativos de una investigación desarrollada durante tres años (2013-2015) en una Escuela Superior de Ingeniería y cuyo objetivo es realizar una aproximación al uso tecnológico, pedagógico y comunicativo que subyace en las propuestas docentes mediadas por la plataforma Moodle. Mediante una metodología mixta, cuantitativa y cualitativa, se utilizaron como fuentes de datos un cuestionario destinado al profesorado y la observación periférica de las 144 asignaturas de grado ofrecidas en la Escuela, pertenecientes a 7 titulaciones de Ingenierías Industriales y de Telecomunicación. Los resultados obtenidos nos muestran que, tras más de una década de utilización de la plataforma, existe una buena adecuación tecnológica de las aulas virtuales, una gradual renovación pedagógica de las propuestas docentes y una escasa explotación de las herramientas comunicativas.The vast majority of on-site nature Universities count on e-learning platforms to back up the education and learning processes. The purpose of this article consists of showing the most significant aspects of an investigation carried out for three years (2013-2015) in a Faculty of Engineering and whose objective is to make an approximation to the technological, pedagogical and communicational use that underlie the teaching proposals mediated by the Moodle platform. By means of a mixed, quantitative and qualitative methodology, a questionnaire intended for the teaching staff and peripheral observation of the 144 subjects offered in the School was used as data sources, pertaining to 7 degrees of Industrial Engineering and Telecommunications. The obtained results show us that, after more than one decade of using the platform, a good technological adjustment in the virtual classrooms exists, as well as a gradual pedagogical renovation of the educational proposals and a limited exploitation of the communicational tools