On air temperature fluctuations immediately above a glacier surface

Developing remote sensing techniques for measuring meteorological parameters in surface layers of snow field

Risk factors for unsuccessful lumbar puncture in children

Background. This descriptive study provides the first information on an association between the use of sedation and a reduction in the prevalence of unsuccessful lumbar puncture (LP) in African children of all races.Objective. Our hypothesis was that children who do not receive any procedural sedation are more likely to have unsuccessful LPs.Methods. A cross-sectional observational study examined LPs performed from February to April 2013, including details of the procedure, sedation or analgesia used, and techniques. The setting was the Medical Emergency Unit at Red Cross War Memorial Children’s Hospital, Cape Town, South Africa, and the participants all children aged 0 - 13 years who had an LP in the unit during the time period.Results. Of 350 children, 62.9% were <12 months of age, the median age being 4.8 months (interquartile range 1.5 - 21.7). The prevalence of unsuccessful (traumatic or dry) LP was 32.3% (113/350). Sedation was used in 107 children (30.6%) and was associated with a reduction in the likelihood of unsuccessful LP (p=0.002; risk ratio (RR) 0.5 (95% confidence interval (CI) 0.34 - 0.78)) except in those <3 months of age, where sedation did not significantly reduce the likelihood (p=0.56; RR 1.20 (95% CI 0.66 - 2.18)).Conclusions. Unsuccessful LP was common. Sedation was not routinely used, but the results suggest that it may be associated with a reduction in the rate of unsuccessful LP. Unsuccessful LP may lead to diagnostic uncertainty, prolonged hospitalisation and unnecessary antibiotic use. Whether a procedural sedation protocol would reduce the rate of unsuccessful LP requires further study

Long term outcome and EuroSCORE II validation in native valve surgery for active infective endocarditis in a South African cohort

Objectives: To evaluate the major risk factors for adverse short and long term outcomes in patients with active native valve infective endocarditis needing cardiac surgery and to validate the EuroSCORE II in our cohort of patients.Methods: We retrospectively studied 149 patients who underwent native valve surgery for infective endocarditis in June 2000 - May 2011 at our referral centre. Ninety-six patients met the inclusion criteria for the study: 29 aortic valve replacements (AVR), 27 mitral valve replacements (MVR), 28 aortic/mitral (double) valve replacements (DVR) and 12 mitral valve repairs (MV Repair).Results: Mechanical valves were implanted in 68 patients (70.8%), bioprosthetic valves in 16 (16.7%) and mitral annuloplasty rings in 12 (12.5%). The Cox proportional hazard model showed that the most important risk factors for early 30-day mortality were: critical preoperative state, emergency surgery, EuroSCORE II >12%, low cardiac output state (LCOS), HIV positive status, preoperative embolic episodes, vegetation size >1cm and postoperative ventilation >24 hours. The EuroSCORE II underestimated early mortality for the entire cohort. The discriminatory ability was evaluated with the receiver operating characteristic (ROC) curve with an area under the curve of 0.796. The discriminatory ability in the subgroup analysis showed that the AUROC curve was poorer for MVR (0.696), 0.837 for DVR and better for AVR group (0.92).Conclusions: The EuroSCORE II underestimated mortality in the highest risk groups and overestimated mortality in the lowest risk groups. The discriminatory ability and model fit were evaluated to be good and a EuroSCORE II >12% predicted a signifi cantly higher early and medium term mortality

High AIDS-related mortality among young women in rural KwaZulu-Natal

Objective. To establish mortality rates and cause of death in a rural community in KwaZulu-Natal. This study was conducted as part of a demographic and health survey to assess the impact of HIV infection in this community. Methods. A cross-sectional survey was conducted between February and July 2004. The survey made use of structured questionnaires and verbal autopsies, which yielded detailed information at household level, including the demographic profile of residents, mortality rates and cause of mortality between February 2003 and February 2004.Results. The overall mortality rate in this community was 2.9 deaths per 100 person-years (95% confidence interval (CI): 2.5 - 3.3 per 100 person-years). The highest mortality rate among women occurred in the 30 - 34-year age group, while among men it occurred in the 35 - 39 and > 60-year age groups. Of the 185 verbal autopsies reported, 77 deaths (42%) were attributable to AIDS. The survey revealed that women aged 20 - 24 and men aged 35 - 39 years were bearing a disproportionately large burden of AIDS-related mortality in this community.Conclusion. AIDS-related mortality was found to be disproportionately high in young women in this small rural community, and the majority of deaths resulted from pulmonary tuberculosis. The need to strengthen prevention and treatment efforts in this and similar settings is highlighted

Euler-Bessel and Euler-Fourier Transforms

We consider a topological integral transform of Bessel (concentric isospectral sets) type and Fourier (hyperplane isospectral sets) type, using the Euler characteristic as a measure. These transforms convert constructible \zed-valued functions to continuous $\real$-valued functions over a vector space. Core contributions include: the definition of the topological Bessel transform; a relationship in terms of the logarithmic blowup of the topological Fourier transform; and a novel Morse index formula for the transforms. We then apply the theory to problems of target reconstruction from enumerative sensor data, including localization and shape discrimination. This last application utilizes an extension of spatially variant apodization (SVA) to mitigate sidelobe phenomena

Tuberculosis burden in stage 5 chronic kidney disease patients undergoing dialysis therapy at Livingstone Hospital, Port Elizabeth, South Africa

Background. Tuberculosis (TB) is currently the leading cause of death from a single infectious agent worldwide. Patients who receive dialysis are particularly vulnerable to TB infection owing to immune dysfunction. Nonetheless, there is a paucity of incidence data on dialysis patients infected with TB in high-burden countries, such as South Africa (SA).Objectives. To determine the incidence of TB in prevalent chronic kidney disease stage 5 (CKD-5D) patients on dialysis at a single centre in Eastern Cape Province, SA, and to identify the risk factors associated with TB infection.Methods. We conducted a retrospective cohort study of all consenting CKD-5D patients between April 2010 and March 2014 at Livingstone Hospital Renal Unit, Port Elizabeth, the Eastern Cape. TB was defined as definite or probable according to World Health Organization (WHO) criteria, and the cohort was split into those who developed TB (TB+) and those who did not (TB−).Results. One hundred and eleven patients were enrolled – predominantly black Africans (73%) and women (53%); the mean age (standard deviation (SD)) was 42 (9.8) years. The prevalence of HIV infection was 11%, all patients were receiving antiretroviral treatment and all had suppressed viral loads. Sixty-eight patients were on haemodialysis and 43 on peritoneal dialysis. Nineteen patients were diagnosed with 20 episodes of TB; 14 cases were pulmonary TB and 6 cases extrapulmonary TB. Of the patients with TB, 2 were HIV-infected, 7 (35%) were definite TB cases and 13 (65%) were probable cases. The calculated incidence rate was 4 505/100 000 patient years. Only informal housing (30% in TB+ v. 12% in TB−; p=0.042) and a history of hospitalisation (90% v. 76%, respectively; p=0.042) were significantly associated with a diagnosis of TB.Conclusions. Dialysis patients in the Eastern Cape region of SA are at extremely high risk of acquiring TB, with an incidence rate 4.1 times that of the local population and >5 times that of the general SA population. Only informal housing and a history of hospitalisation were identified as positive risk factors for TB in this young population with a low HIV prevalence. Isoniazid prophylaxis in this high-risk group might be of benefit, but further studies are required to inform such treatment

Water-filled technique for therapeutic pancreato-biliary EUS in patients with surgically altered anatomy

One of the main challenges encountered by endosonographers is performing diagnostic and interventional pancreato-biliary endoscopic ultrasound (EUS) procedures in the presence of surgically altered upper gastrointestinal anatomy. We describe the water-filled technique (WFT) for EUS examination and treatment of the pancreato-biliary region in patients with surgically altered upper gastrointestinal anatomy. Using the WFT, the scope is advanced up to the gastro-jejunal anastomosis and, after placing the tip of the scope 2 cm beyond it, enlargement of the jejunal lumen is obtained by water instillation of the jejunal loop. An enlargement of more than 1.5 cm allows advancement of the tip of the scope under EUSguidance up to the duodenum, in a retrograde way. The WFT is useful for reaching the ampullary area and performing diagnostic and therapeutic EUS in patients with surgically altered anatomy. The technique is also reproducible and can be easily used by endoscopists who regularly perform EUS

Risk factors for unsuccessful lumbar puncture in children

Background. This descriptive study provides the first information on an association between the use of sedation and a reduction in the prevalence of unsuccessful lumbar puncture (LP) in African children of all races.Objective. Our hypothesis was that children who do not receive any procedural sedation are more likely to have unsuccessful LPs.Methods. A cross-sectional observational study examined LPs performed from February to April 2013, including details of the procedure, sedation or analgesia used, and techniques. The setting was the Medical Emergency Unit at Red Cross War Memorial Children’s Hospital, Cape Town, South Africa, and the participants all children aged 0 - 13 years who had an LP in the unit during the time period.Results. Of 350 children, 62.9% were <12 months of age, the median age being 4.8 months (interquartile range 1.5 - 21.7). The prevalence of unsuccessful (traumatic or dry) LP was 32.3% (113/350). Sedation was used in 107 children (30.6%) and was associated with a reduction in the likelihood of unsuccessful LP (p=0.002; risk ratio (RR) 0.5 (95% confidence interval (CI) 0.34 - 0.78)) except in those <3 months of age, where sedation did not significantly reduce the likelihood (p=0.56; RR 1.20 (95% CI 0.66 - 2.18)).Conclusions. Unsuccessful LP was common. Sedation was not routinely used, but the results suggest that it may be associated with a reduction in the rate of unsuccessful LP. Unsuccessful LP may lead to diagnostic uncertainty, prolonged hospitalisation and unnecessary antibiotic use. Whether a procedural sedation protocol would reduce the rate of unsuccessful LP requires further study