Pulmonary arterial wall distensibility assessed by intravascular ultrasound in children with congenital heart disease: an indicator for pulmonary vascular disease?

BACKGROUND: Both pulmonary hypertension and pulmonary overflow are associated with functional and structural changes of the pulmonary arterial wall. Current techniques to evaluate the pulmonary vasculature neglect the pulsatile nature of pulmonary flow. STUDY OBJECTIVES: To determine whether the dynamic properties of the pulmonary arterial wall are altered in patients with abnormal pulmonary hemodynamics due to congenital heart defects, and whether these changes are associated with the progression of pulmonary vascular disease (PVD). PATIENTS AND METHODS: In 43 children with PVD due to congenital heart defects and 12 control subjects, pulmonary arterial pulsatility (the relative increase in vessel area during the cardiac cycle) and distensibility (the inverse of the stress/strain elastic modulus) were determined with intravascular ultrasound. Results were correlated with clinical and hemodynamic parameters. RESULTS: Pulsatility correlated with pulmonary pulse pressure (p < 0.001), pulmonary-to-systemic vascular resistance ratio (PVR/SVR) [p = 0.001], and hemoglobin concentration (p = 0.01). However, when corrected for these variables, pulsatility did not differ between patients and control subjects. In contrast, arterial wall distensibility decreased with the severity of PVD and correlated independently with pulmonary-to-systemic arterial pressure ratio (p < 0.001) and PVR/SVR (p = 0.03), and with hemoglobin concentration (p < 0.01). Adjusted for hemodynamic variables, distensibility was still decreased in patients with PVD compared to control subjects. CONCLUSIONS: These results demonstrate that pulmonary arterial wall distensibility is progressively decreased in PVD; moreover, this decreased distensibility is, in part, related to increased distending pressure as a result of pulmonary hypertension but also, in part, to stiffening of the arterial wall during the disease process. Arterial wall distensibility may be of additional value in the evaluation of pulmonary vasculature and ventricular workload

The impact of mechanized processing of cassava on farmers' production efficiency in Uganda

The study investigates the impact of adopting mechanized processing of cassava on farmers’ production efficiency in Uganda. A stochastic production function, using translog functional form, was used to compare efficiency measures of farmers in mechanized cassava-processing villages compared with the farmers in nonmechanized cassava-processing villages in 2014. Given the specification of the translog production function, the mean technical efficiencies of the farmers were 0.69 and 0.52 in mechanized and nonmechanized villages, respectively. The significant determinants of technical inefficiency among the respondents are farming experience, education, membership of farmer association, access to markets, sale of cassava to processors and farmers who planted cassava as sole crop are all negative, which confirm to a priori expectations and significant at different levels. The policy implication of the study is that mechanization of cassava processing, particularly if done at the right scale, could create demand that can transform primary production for increased yields, higher incomes and production efficiency of smallholder farmers who constitute a significant proportion of Uganda’s agricultural sector

Worrying about wasting GP time as a barrier to help-seeking: a community-based, qualitative study

Background Worrying about wasting GP time is frequently cited as a barrier to help-seeking for cancer symptoms. Aim To explore the circumstances under which individuals feel that they are wasting GP time. Design and setting Community-based, qualitative interview studies that took place in London, the South East and the North West of England. Method Interviewees (n = 62) were recruited from a sample (n = 2042) of adults aged ≥50 years, who completed a ‘health survey’ that included a list of cancer ‘alarm’ symptoms. Individuals who reported symptoms at baseline that were still present at the 3-month follow-up (n = 271), and who had also consented to be contacted (n = 215), constituted the pool of people invited for interview. Analyses focused on accounts of worrying about wasting GP time. Results Participants were worried about wasting GP time when time constraints were visible, while dismissive interactions with their GP induced a worry of unnecessary help-seeking. Many felt that symptoms that were not persistent, worsening, or life-threatening did not warrant GP attention. Additionally, patients considered it time-wasting when they perceived attention from nurses or pharmacists to be sufficient, or when appointment structures (for example, ‘one issue per visit’) were not adhered to. Close relationships with GPs eased worries about time-wasting, while some patients saw GPs as fulfilling a service financed by taxpayers

Does the Merton model apply to the specific circumstances of emerging markets?

The purpose was to investigate whether the Merton Model works in emerging markets and if it does how efficient it works there compared to in mature markets. Findings show that the Merton model works in emerging markets and considers country specific information, yet only through stock prices and volatility. However, the model does not account for quality and availability of information in these countries which in turn have a negative impact on market efficiency

Promoting help-seeking in response to symptoms amongst primary care patients at high risk of lung cancer: a mixed method study

Background: Lung cancer symptoms are vague and difficult to detect. Interventions are needed to promote early diagnosis, however health services are already pressurised. This study explored symptomology and help-seeking behaviours of primary care patients at ‘high-risk’ of lung cancer (≥50 years old, recent smoking history), to inform targeted interventions. Methods: Mixed method study with patients at eight general practitioner (GP) practices across south England. Study incorporated: postal symptom questionnaire; clinical records review of participant consultation behaviour 12 months pre- and post-questionnaire; qualitative participant interviews (n = 38) with a purposive sample. Results: A small, clinically relevant group (n = 61/908, 6.7%) of primary care patients was identified who, despite reporting potential symptoms of lung cancer in questionnaires, had not consulted a GP ≥12 months. Of nine symptoms associated with lung cancer, 53.4% (629/1172) of total respondents reported ≥1, and 35% (411/1172) reported ≥2. Most participants (77.3%, n = 686/908) had comorbid conditions; 47.8%, (n = 414/908) associated with chest and respiratory symptoms. Participant consulting behaviour significantly increased in the 3-month period following questionnaire completion compared with the previous 3-month period (p = .002), indicating questionnaires impacted upon consulting behaviour. Symptomatic non-consulters were predominantly younger, employed, with higher multiple deprivation scores than their GP practice mean. Of symptomatic non-consulters, 30% (18/61) consulted ≤1 month post-questionnaire, with comorbidities subsequently diagnosed for five participants. Interviews (n = 39) indicated three overarching differences between the views of consulting and non-consulting participants: concern over wasting their own as well as GP time; high tolerance threshold for symptoms; a greater tendency to self-manage symptoms. Conclusions: This first study to examine symptoms and consulting behaviour amongst a primary care population at ‘high- risk’ of lung cancer, found symptomatic patients who rarely consult GPs, might respond to a targeted symptom elicitation intervention. Such GP-based interventions may promote early diagnosis of lung cancer or other comorbidities, without burdening already pressurised services