The effect of oxygen, temperature and hydrogen sulphide on the human pulmonary circulation

Introduction: The human pulmonary circulation is poorly understood at a physiological level which is a shame given that the pathology affecting it, particularly pulmonary artery hypertension, can have detrimental effects not only in the lungs but on the heart. Pulmonary artery hypertension in its acute or chronic form carries a high mortality. Few centres have the luxury to utilise human tissue to study this phenomenon. My thesis looks at the effect of certain stimuli such as oxygen, temperature and hydrogen sulphide to discern their role in governing pulmonary artery reactivity at both the tissue and organ level.Methods: Tissue was supplied from lungs taken from patients with lung cancer following resection of the tumour during surgery. I used a combination of isolated arterial ring models in organ baths and isolated perfused lung models to study the factors governing pulmonary arterial tone and pulmonary artery pressures at a tissue and organ level respectively.Results: At the tissue level, hypoxia caused nitric-oxide independent dilation of human pulmonary arteries whilst hyperoxia caused a vasoconstriction. This hyperoxic vasoconstriction is dependent on both voltage gated calcium-channels in the cell membrane as well as release from intracellular calcium stores. It is also dependent on oxygen-free radicals. Hypothermia blunts this vasoconstrictive response to hyperoxia as well as endothelin-1 and potassium chloride-mediated pulmonary smooth muscle contraction. Hydrogen sulphide dilates pulmonary arteries. At the organ level, oxygen changes either via the perfusate or the ventilator do not affect pulmonary artery pressures. Both hypothermia and hydrogen sulphide reduce both pulmonary artery pressures and bronchial pressures.Conclusions: Compensatory mechanisms within the pulmonary circulation may compensate for hypoxic vasodilation and hyperoxic vasoconstriction or there may be a systemic component to entities such as “hypoxic pulmonary vasoconstriction” seen in animal models. Hydrogen sulphide may provide a possible treatment avenue for pulmonary artery hypertension

Explorando la Prevalencia del Comportamiento de Ciudadanía Organizacional en Profesores y sus Determinantes: Evidencias de un Medio Cultural Poco Investigado

Teachers’ organizational citizenship behaviour (OCB) is the teacher behaviour that is discretionary, not directly or explicitly recognised by the formal reward system. The factors found to be determining Teachers’ OCB are different, hinging on country-culture specific nature. Research studies in the sphere of Teachers’ OCB have heretofore been overlooked in Sri Lanka and other similar Asian countries. Hence, this study aims at exploring the degree of prevalence of teacher OCB and its dominant determinants among the teachers in Sri Lanka. The study draws on in-depth qualitative data from interviews and the participants included a convenience sample of teachers and principals employed in secondary schools. The data were analysed deductively using content analysis method. The findings reveal that the teachers’ propensity to perform OCB - towards students, school and their colleagues - is on the decline. The determinants, such as work-family conflict, perceived organizational support, teacher values, teachers’ self-efficacy, student behaviour patterns, and teachers’ pupil control ideologies, seem to be dominant attributing to the low levels of teachers’ OCB.El comportamiento cívico organizacional de los profesores (CCO) es el comportamiento de los docentes que es discrecional, no reconocido directa o explícitamente por el sistema formal de recompensas. Los factores que determinan el CCO de los profesores son diferentes, y dependen de la naturaleza específica de la cultura del país. Hasta ahora, los estudios de investigación en la esfera del CCO de los docentes se han pasado por alto en Sri Lanka y otros países asiáticos similares. Por consiguiente, el presente estudio tiene por objeto explorar el grado de prevalencia del CCO del profesorado y sus determinantes dominantes entre los profesores de Sri Lanka. El estudio se basa en datos cualitativos detallados procedentes de entrevistas y los participantes incluyeron una muestra de conveniencia de maestros y directores empleados en escuelas secundarias. Los datos se analizaron de manera deductiva utilizando el método de análisis del contenido. Las conclusiones revelan que la propensión de los profesores a realizar CCO - hacia los estudiantes, la escuela y sus colegas - está disminuyendo. Los factores determinantes, como el conflicto entre el trabajo y la familia, el apoyo organizativo percibido, los valores de los maestros, la autoeficacia de los maestros, las pautas de comportamiento de los estudiantes y las ideologías de control de los alumnos de los maestros, parecen ser los factores dominantes que se atribuyen a los bajos

The utility of CT angiography in planning perineal flap reconstruction following radical pelvic surgery

AbstractIntroductionClosure of the perineum following radical excision of pelvic tumours can prove to be a complex surgical problem. A number of pedicled flaps have been used for perineal reconstruction in order to reduce post-operative complications such as infection and abscess formation. The aim of this case series was to analyse the use of pre-operative computer tomography (CT) angiography to guide flap selection for perineal reconstruction following radical excision of pelvic tumours.MethodsWe conducted a retrospective review to identify all patients who underwent CT angiography prior to radical excision of pelvic tumours and planned flap reconstruction over an 18 month period. Six patients were identified and are presented in this case series. Patients' medical records, histology reports, pre-operative investigations and CT angiograms, complications and follow-up were reviewed.ResultsThe mean patient age was 58.3 years, with a male to female ratio of 1:2. Four out of six patients (66.6%) underwent pre-operative radiotherapy. The deep inferior epigastric arteries (DIEA) were visualised in all six cases (100%) and the pre-operative CT angiography helped guide flap choice in all cases (100%). In one case, narrowing of the DIEA vessels was noted precluding the use of a DIEA-based flap. One patient had a minor superficial wound dehiscence.ConclusionPre-operative CT angiography allows accurate visualisation of the DIEA system including perforator vessels. CT angiography is a useful tool, providing the surgical team with significant additional information to aid pre-operative planning and optimise reconstructive choice and outcome

Liver and brain abscess caused by Aggregatibacter paraphrophilus in association with a large patent foramen ovale: a case report

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Introduction Aggregatibacter paraphrophilus (former name Haemophilus paraphrophilus) is a normal commensal of the oral flora. It is a rare cause of hepatobiliary or intracerebral abscesses. Case presentation We report a case of a 53-year-old Caucasian man with a liver abscess and subsequent brain abscesses caused by Aggregatibacter paraphrophilus. The probable source of the infection was the oral flora of our patient following ingestion of a dental filling. The presence of a large patent foramen ovale was a predisposing factor for multifocal abscesses. Conclusion In this case report, we describe an unusual case of a patient with both liver and brain abscesses caused by an oral commensal Aggregatibacter paraphrophilus that can occasionally show significant pathogenic potential.Published versio

Effect of playing Nathaswaram on lung function

Objectives: To compare the respiratory function of Nathaswaram players with other players of the same troupe in Colombo district.Methods: A descriptive study was conducted on 30 nathaswaram players and 30 other instrument players in Colombo district. Information of sociodemographic variables, habits and illnesses were obtained using an interviewer administered questionnaire. Clinical examination was conducted and respiratory function tests were performed using a Vitallograph spirometer.Results: The mean age, height and weight of the players and other players were comparable (p > 0.05).The mean FVC of the Nathaswaram players was statistically significantly higher than the other players (2.99 L ± 0.79 SD of players Vs 2.11 L ± 0.84 SD of controls, p<0.05). The mean FEV1 of the Nathaswaram players were statistically significantly higher than the other players (2.81 L± 0.84 SD of players Vs 1.90 L ± 0.78 SD of controls, p<0.05).The mean FEF of the Nathaswaram players were statistically significantly higher than the other players (4.10 L ± 1.41 SD of players Vs 3.45 L ± 1.63 SD of controls, p<0.05).Conclusions: This study suggests regular playing of the Nathaswaram improves large airway function. However the smaller airway function did not show any significant change

Ethics Review Committee approval and informed consent: an analysis of biomedical publications originating from Sri Lanka

<p>Abstract</p> <p>Background</p> <p>International guidelines on research have focused on protecting research participants. Ethical Research Committee (ERC) approval and informed consent are the cornerstones. Externally sponsored research requires approval through ethical review in both the host and the sponsoring country. This study aimed to determine to what extent ERC approval and informed consent procedures are documented in locally and internationally published human subject research carried out in Sri Lanka.</p> <p>Methods</p> <p>We obtained ERC approval in Sri Lanka and the United Kingdom. Theses from 1985 to 2005 available at the Postgraduate Institute of Medicine (PGIM) library affiliated to the University of Colombo were scrutinised using checklists agreed in consultation with senior research collaborators. A Medline search was carried out with MeSH major and minor heading 'Sri Lanka' as the search term for international publications originating in Sri Lanka during 1999 to 2004. All research publications from CMJ during 1999 to 2005 were also scrutinized.</p> <p>Results</p> <p>Of 291 theses, 34% documented ERC approvals and 61% documented obtaining consent. From the international journal survey, 250 publications originated from Sri Lanka of which only 79 full text original research publications could be accessed electronically. Of these 38% documented ERC approval and 39% documented obtaining consent. In the Ceylon Medical Journal 36% documented ERC approval and 37% documented obtaining consent.</p> <p>Conclusion</p> <p>Only one third of the publications scrutinized recorded ERC approval and procurement of informed consent. However, there is a positive trend in documenting these ethical requirements in local postgraduate research and in the local medical journal.</p

Bio-Repository of DNA in stroke (BRAINS): A study protocol

<p>Abstract</p> <p>Background</p> <p>Stroke is one of the commonest causes of mortality in the world and anticipated to be an increasing burden to the developing world. Stroke has a genetic basis and identifying those genes may not only help us define the mechanisms that cause stroke but also identify novel therapeutic targets. However, large scale highly phenotyped DNA repositories are required in order for this to be achieved.</p> <p>Methods</p> <p>The proposed Bio-Repository of DNA in Stroke (BRAINS) will recruit all subtypes of stroke as well as controls from two different continents, Europe and Asia. Subjects recruited from the UK will include stroke patients of European ancestry as well as British South Asians. Stroke subjects from South Asia will be recruited from India and Sri Lanka. South Asian cases will also have control subjects recruited.</p> <p>Discussion</p> <p>We describe a study protocol to establish a large and highly characterized stroke biobank in those of European and South Asian descent. With different ethnic populations being recruited, BRAINS has the ability to compare and contrast genetic risk factors between those of differing ancestral descent as well as those who migrate into different environments.</p

Challenges and satisfaction in Cardiothoracic Surgery Residency Programmes: insights from a Europe-wide survey.

OBJECTIVES: The increasing complexity of surgical patients and working time constraints represent challenges for training. In this study, the European Association for Cardio-Thoracic Surgery Residents' Committee aimed to evaluate satisfaction with current training programmes across Europe. METHODS: We conducted an online survey between October 2018 and April 2019, completed by a total of 219 participants from 24 countries. RESULTS: The average respondent was in the fourth or fifth year of training, mostly on a cardiac surgery pathway. Most trainees follow a 5-6-year programme, with a compulsory final certification exam, but no regular skills evaluation. Only a minority are expected to take the examination by the European Board of Cardiothoracic Surgery. Participants work on average 61.0 ± 13.1 h per week, including 27.1 ± 20.2 on-call. In total, only 19.7% confirmed the implementation of the European Working Time Directive, with 42.0% being unaware that European regulations existed. Having designated time for research was reported by 13.0%, despite 47.0% having a postgraduate degree. On average, respondents rated their satisfaction 7.9 out of 10, although 56.2% of participants were not satisfied with their training opportunities. We found an association between trainee satisfaction and regular skills evaluation, first operator experience and protected research time. CONCLUSIONS: On average, residents are satisfied with their training, despite significant disparities in the quality and structure of cardiothoracic surgery training across Europe. Areas for potential improvement include increasing structured feedback, research time integration and better working hours compliance. The development of European guidelines on training standards may support this