378 research outputs found
The epidemiology of operations performed by the National Sea Rescue Institute of South Africa over a 5-year period
Background: Injuries remain a major contributor of morbidity and mortality worldwide, with drowningaccounting for 7% of all injury-related deaths with rates of between 4 and 8 per 100,000. The Africanregion has death rates comparable to most low-income countries. Non-fatal drowning in Africa remainsunquantified but it is estimated to be ten times higher than the fatal drowning rate. Timely search andrescue, initial resuscitation and rapid transportation to definitive care play a crucial role in preventing injury-related morbidity and mortality. The National Sea Rescue Institute (NSRI) of South Africa is a non-profitorganisation responsible for ~97% of maritime search and rescue operations in South Africa (includinginland navigable waters). The aim of the study was to describe the epidemiology of operations performedby the NSRI of South Africa over a 5-year period.Materials and methods: The NSRI operational database was analysed from 1 January 2010 to 31 December2014. Summary statistics are presented.Results: The NSRI launched 3281 operations over the study period. Marked seasonal variation were noticeablewith peak periods in December and January, corresponding to the South African summer holidayseason. Water-based operations (67.6%) were the most frequent operation performed. The NSRI assisted3399 individuals of which 77% were male. The mean age of rescued persons was 42 years. Eight hundredand thirty-six (25%) individuals had non-fatal injuries or illnesses requiring medical assistance. Medicalemergencies (35%), traumatic injuries (32.8%), and non-fatal drownings (23%) were the most commontypes of injury and illness. The majority of the 184 (18%) deaths recorded were due to drowning (75%).Conclusions: Injury and illness, specifically drowning utilise a large proportion of search and rescue services.The results suggest further preventative measures and public health strategies be implemented tominimise traumatic and medical incident severity and subsequent casualties at sea
Studies of the gastro-oesophageal junction in normal and overweight healthy volunteers
Introduction: Oesophageal adenocarcinoma has increased dramatically in incidence over the past three decades with a particularly high burden of disease at the gastro-oesophageal junction. Many cases occur in individuals without known gastro-oesophageal reflux disease and in the absence of Barrett’s oesophagus suggesting that mechanisms other than traditional reflux may be important.
Distal squamous mucosa may be prone to acid damage even in the absence of traditional reflux by the mechanism of distal opening of the lower oesophageal sphincter. This is splaying of the distal segment of lower oesophageal sphincter allowing acid ingress without traditional reflux.
It has been suggested that the cardiac mucosa at the gastro-oesophageal junction, separating oesophageal squamous mucosa and acid secreting columnar mucosa of the stomach may be an abnormal mucosa arising as a consequence of acid damage. By this theory the cardiac mucosa is metaplastic and akin to ultra-short Barrett’s oesophagus.
Obesity is a known risk factor for adenocarcinoma at the gastro-oesophageal junction and its rise has paralleled that of oesophageal cancer. Some of this excess risk undoubtedly operates through stress on the gastro-oesophageal junction and a predisposition to reflux. However we sought to explore the impact of obesity on the gastro-oesophageal junction in healthy volunteers without reflux and in particular to determine the characteristics of the cardiac mucosa and mechanisms of reflux in this group.
Methods: 61 healthy volunteers with normal and increased waist circumference were recruited. 15 were found to have a hiatus hernia during the study protocol and were analysed separately. Volunteers had comprehensive pathological, physiological and anatomical assessments of the gastro-oesophageal junction including endoscopy with biopsies, MRI scanning before and after a standardised meal, prolonged recording of pH and manometry before and after a meal and screening by fluoroscopy to identify the squamo-columnar junction.
In the course of the early manometric assessments a potential error associated with the manometry system recordings was identified. We therefore also sought to document and address this on the benchtop and in vivo.
Key Findings:
1. In documenting the behaviour of the manoscan we described an immediate effect of temperature change on the pressure recorded by the sensors; ‘thermal effect’ and an ongoing drift of the recorded pressure with time; ‘baseline drift’. Thermal effect was well compensated within the standard operation of the system but baseline drift not addressed. Applying a linear correction to recorded data substantially reduced the error associated with baseline drift.
2. In asymptomatic healthy volunteers there was lengthening of the cardiac mucosa in association with central obesity and age. Furthermore, the cardiac mucosa in healthy volunteers demonstrated an almost identical immunophenotype to non-IM Barrett’s mucosa, which is considered to arise by metaplasia of oesophageal squamous mucosa. These findings support the hypothesis that the cardia is metaplastic in origin.
3. We have demonstrated a plausible mechanism of damage to distal squamous mucosa in association with obesity. In those with a large waist circumference we observed increased ingress of acid within but not across the lower oesophageal sphincter; ‘intrasphincteric reflux’
4. The 15 healthy volunteers with a hiatus hernia were compared to 15 controls matched for age, gender and waist circumference. Those with a hiatus hernia had a longer cardiac mucosa and although they did not have excess traditional reflux they had excess distal acid exposure by short segment acid reflux and intrasphincteric acid reflux.
Conclusions: These findings are likely to be relevant to adenocarcinoma of the gastro-oesophageal junctio
One-ended Transposition of Tn1/3
The plasmids pBR322 and pPAK100 each contain one half of a transposon. pBR322 contains the right half of Tn3 while pPAK100 contains the left half of Tn1. These half transposons were assayed for the ability to transpose and in both cases transposition was detected at frequencies about 1000 times lower than wild type. The same half transposons were found to confer transposition immunity to a plasmid, and the level of immunity was found to be the same whether the whole transposon or only half of it was present. A series of deletion mutants was constructed, using restriction enzymes and the exonuclease BAL 31. These were assayed for the ability to transpose and to confer immunity to the host plasmid. All the deletion mutants except one were able to transpose and to cause transposition immunity. The exception which did not transpose was sequenced and found to have lost most of its transposon sequences, including all of the inverted repeat. The others all still contained their inverted repeat sequences. One-ended transposition resulted in the formation of cointegrates between the donor plasmid and the recipient, R388. All experiments were performed in recA strains of E. coli and in the absence of resolvase, therefore no break down of cointegrates was possible and the transposition event was stopped at the cointegrate stage. Restriction enzyme analysis of these cointegrates revealed that the donor plasmid was inserted at many places into the recipient plasmid and the two plasmids were joined at the junction of the inverted repeat and plasmid sequences. All the cointegrates analysed had the transposon inserted in the same orientation, but the relatively small number analysed means that the possibility of finding inserts in the opposite orientation cannot be excluded. No duplication of transposon sequences was detected using restriction enzymes, however a duplication of about 100bp. or less would not have been detected using this system. Sequencing work on three examples done in this laboratory (A. Arthur, pers. comm. ) has shown that there has been a small duplication of the inverted repeat sequences. In the three examples studied the duplication was 13bp., 32bp. and 100bp. Sequencing was also done to discover whether there had been any duplication of target sequences. It was found that, as in "normal" transposition, a 5bp. duplication had occurred. The data infers that transposons having only one inverted repeat are able to transpose, and that transposition can occur using either of the inverted repeats. It is still unclear whether transposition occurs by a symmetric or asymmetric mechanism, although the evidence of Craigie and Mizuuchi, (1985), strongly suggests that at least in the case of Mu, transposition occurs in a symmetric fashion
Parents and the preschool PATHS (Promoting Alternative Thinking Strategies) curriculum
Purpose - The purpose of this paperis to consider evidence on the effectiveness of preschool social and emotionalinterventions in preschool contexts and focuses on the application of an implementation framework described in relation to the Preschool Promoting Alternative Thinking Strategies (PATHS) curriculum. Active parent involvementand engagement were not included in the implementation but preschool establishments spontaneously involved parents or parents sought involvement, creating innovations in delivery and context. The need for structured parent involvement and its impact are considered in relation to evidence on integrated programmes and different models of parent involvement. Design/methodology/approach - This paper reports on an interim evaluation of practitioners' and parents' experiences of the implementation processes, focusing on the involvement andengagement of parents. Findings - Evidence for the rationale for parent engagement in this context is substantiated. The Preschool PATHS curriculum is known to impact on children's social competence, problem behaviour and, in the early school context, attainment. However the programme does not target parent skill directly or address parent behaviours that mayaffect children's social competence and behaviour. It is suggested that theprogramme needs to be extended to provide structured input for parents via training and information similar to that provided for practitioners. A pilot study using integrated parent training material and supported by an implementation framework is advised. Originality/value - The paper describes a flexible, evidence-based framework supporting replicable processes useful to service providers across programmes and contexts. An "innovation" (a term used to describe deviations from programme fidelity or implementation standards) is explored which affected the creation of parallel parent involvement strategies but not the delivery of the programme itself which was carefully monitored. While adaptations and deviations are inevitable, some flag up areas where development or issues of contextual fit need to be addressed and might, as in this case, inform better integration of evidence and practice development
An investigation of personality characteristics and demographic profiles of women and men in management positions
The purpose of this study was to investigate the personality characteristics and demographic profiles of women in upper-level management positions and describe how they differed from men in upper-level management positions and women in middle-level management positions. The participants in the study consisted of 136 upper-level women, 775 upper-level men, 307 middle-level women, and 800 middle-level men who had participated in programs at the Center for Creative Leadership in Greensboro, North Carolina from January, 1985 to September, 1989. A multivariate analysis of covariance was utilized initially, covarying age and time as manager with the personality characteristic data from the California Psychological Inventory (CPI), the Fundamental Interpersonal Relations Orientation-Behavior (FIRO-B), and the Myers Briggs Type Indicator (MBTI)indices. Univariate analyses were then performed, after adjustment of means for age and time as manager, to determine differences between groups on the various personality indices. T-tests were performed to test for demographic differences and chi-square analyses determined discrete MBTI indices differences
The potential of early years’ childcare to reduce mental health inequalities of school age children in Scotland
Preschool childcare is considered an important policy for reducing inequalities in children's cognitive and socio-emotional development, although the population-level benefits for children under three years, is less clear. We examined the potential for childcare across the whole early years' period to benefit mental health and reduce inequalities, under different hypothetical policy scenarios, in the Growing Up in Scotland study.
Marginal structural logistic regression models estimated odds ratios (ORs) to quantify inequalities in mental health and consider how these would be altered under different hypothetical scenarios. Mental health (the outcome) was measured using the total Strengths and Difficulties Questionnaire score at the start of primary school. Socioeconomic circumstances (the exposure) were represented by maternal educational measured in infancy. Sequence analysis identified common patterns of childcare usage from 10 months to four years (the mediator). Confounders were adjusted for using inverse probability of treatment weights and analyses accounted for sampling design and attrition (complete case sample, n = 3205).
With virtually universal uptake of government-funded childcare at 3–4 years, most variation was seen before age three. Four groups were identified: ‘Parents, family & friends’ (35.8%), ‘Grandparents’ (32.7%), ‘Private group childcare’ (e.g. nurseries 23.5%), ‘Single professional care’ (e.g. childminders 8.1%). Children whose mothers had low, compared to high, educational qualifications were 3.18 times more likely to have mental health problems (95% CI: 1.88–5.37). In a hypothetical scenario where everyone received private group childcare, inequalities increased slightly to 3.78 (95%CI: 1.46–9.76). In an alternative scenario, where everyone received single professional childcare, inequalities in mental health reduced to 2.42 (95% CI: 0.20–28.76), albeit with wide confidence intervals.
Universal childcare provision before three years may widen or narrow socioeconomic inequalities in children's mental health, depending on the childcare type provided. Further research is required to understand the role of childcare quality, which we were unable to account for
Dynamic changes in lung microRNA profiles during the development of pulmonary hypertension due to chronic hypoxia and monocrotaline
<b>Objective</b>: MicroRNAs (miRNAs) are small noncoding RNAs that have the capacity to control protein production through binding "seed" sequences within a target mRNA. Each miRNA is capable of potentially controlling hundreds of genes. The regulation of miRNAs in the lung during the development of pulmonary arterial hypertension (PAH) is unknown.<p></p>
<b>Methods and Results</b>: We screened lung miRNA profiles in a longitudinal and crossover design during the development of PAH caused by chronic hypoxia or monocrotaline in rats. We identified reduced expression of Dicer, involved in miRNA processing, during the onset of PAH after hypoxia. MiR-22, miR-30, and let-7f were downregulated, whereas miR-322 and miR-451 were upregulated significantly during the development of PAH in both models. Differences were observed between monocrotaline and chronic hypoxia. For example, miR-21 and let-7a were significantly reduced only in monocrotaline-treated rats. MiRNAs that were significantly regulated were validated by quantitative polymerase chain reaction. By using in vitro studies, we demonstrated that hypoxia and growth factors implicated in PAH induced similar changes in miRNA expression. Furthermore, we confirmed miR-21 downregulation in human lung tissue and serum from patients with idiopathic PAH.<p></p>
<b>Conclusion</b>: Defined miRNAs are regulated during the development of PAH in rats. Therefore, miRNAs may contribute to the pathogenesis of PAH and represent a novel opportunity for therapeutic intervention.<p></p>
Demonstration of the anthelmintic potency of marimastat in the Heligmosomoides polygyrus rodent model
In the course of a structure based drug discovery program the known anticancer candidate marimastat was uncovered as a potent inhibitor of an enzyme in nematode cuticle biogenesis. It was shown to kill Caenorhabditis elegans, and the sheep parasites Haemonchus contortus and Teladorsagia circumcinta via an entirely novel nematode-specific pathway, specifically by inhibiting cuticle-remodelling enzymes that the parasites require for the developmentally essential moulting process. This discovery prompted an investigation of the compound's effect on Heligmosomoides polygyrus parasites in a mouse model of helminth infection. Mice were administered the drug via oral gavage daily from day of infection for a period of 2 wk. A second group received the drug via intra-peritoneal implantation of an osmotic minipump for 4 wk. Control groups were administered identical volumes of water by oral gavage in both cases. Counts of H. polygyrus faecal egg and larval load showed that marimastat effected a consistent and significant reduction in egg laying, and a consistent but minor reduction in adult worm load when administered every day, starting on the first day of infection. However, the drug failed to have any significant effect on egg counts or worm burdens when administered to mice with established infections. Therefore, marimastat does not appear to show promise as an anthelmintic in gastrointestinal nematode infections, although other metalloproteases such as batimastat may prove more effective
Posterior Interosseous Nerve of the Elbow
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135289/1/jum2010295691.pd
- …