Ground-based and airborne in-situ measurements of the Eyjafjallajökull volcanic aerosol plume in Switzerland in spring 2010

The volcanic aerosol plume resulting from the Eyjafjallajökull eruption in Iceland in April and May 2010 was detected in clear layers above Switzerland during two periods (17–19 April 2010 and 16–19 May 2010). In-situ measurements of the airborne volcanic plume were performed both within ground-based monitoring networks and with a research aircraft up to an altitude of 6000 m a.s.l. The wide range of aerosol and gas phase parameters studied at the high altitude research station Jungfraujoch (3580 m a.s.l.) allowed for an in-depth characterization of the detected volcanic aerosol. Both the data from the Jungfraujoch and the aircraft vertical profiles showed a consistent volcanic ash mode in the aerosol volume size distribution with a mean optical diameter around 3 ± 0.3 μm. These particles were found to have an average chemical composition very similar to the trachyandesite-like composition of rock samples collected near the volcano. Furthermore, chemical processing of volcanic sulfur dioxide into sulfate clearly contributed to the accumulation mode of the aerosol at the Jungfraujoch. The combination of these in-situ data and plume dispersion modeling results showed that a significant portion of the first volcanic aerosol plume reaching Switzerland on 17 April 2010 did not reach the Jungfraujoch directly, but was first dispersed and diluted in the planetary boundary layer. The maximum PM10 mass concentrations at the Jungfraujoch reached 30 μgm−3 and 70 μgm−3 (for 10-min mean values) duri ng the April and May episode, respectively. Even low-altitude monitoring stations registered up to 45 μgm−3 of volcanic ash related PM10 (Basel, Northwestern Switzerland, 18/19 April 2010). The flights with the research aircraft on 17 April 2010 showed one order of magnitude higher number concentrations over the northern Swiss plateau compared to the Jungfraujoch, and a mass concentration of 320 (200–520) μgm−3 on 18 May 2010 over the northwestern Swiss plateau. The presented data significantly contributed to the time-critical assessment of the local ash layer properties during the initial eruption phase. Furthermore, dispersion models benefited from the detailed information on the volcanic aerosol size distribution and its chemical composition.

Effect of oral donepezil on intraocular pressure in normotensive Alzheimer patients

Donepezil, a selective acetylcholinesterase (AChE) inhibitor, has been shown to reduce intraocular pressure (IOP) in ocular normotensive rabbit eyes. The aim of this investigation was to evaluate the effect of oral donepezil on IOP and pupil diameter after mid-term oral treatment in normotensive persons. Thirty-two newly diagnosed Alzheimer patients with normal IOP and no further antiglaucomatous treatment were included in the study. IOP and pupil diameter were evaluated before and 4 weeks after daily intake of 5 mg donepezil. IOP and pupil diameter were significantly lower/smaller after 4 weeks of treatment. The mean IOP of all 63 eyes was 14.1 mmHg before and 12.8 mmHg after treatment (8.8% reduction). Mean pupil diameter constricted from 3.9 to 3.6 mm (-7.4%). These findings show that donepezil, and, possibly, other selective AChE inhibitors, can potentially be used to treat glaucoma. They are also known to have neuroprotective effects in Alzheimer's, and, therefore, might have an additional therapeutic benefit.

Substitutions due to antiretroviral toxicity or contraindication in the first 3 years of antiretroviral therapy in a large South African cohort

INTRODUCTION: The patterns and reasons for antiretroviral therapy (ART) drug substitutions are poorly described in resource-limited settings. METHODS: Time to and reason for drug substitution were recorded in treatment-naive adults receiving ART in two primary care treatment programmes in Cape Town. The cumulative proportion of patients having therapy changed because of toxicity was described for each drug, and associations with these changes were explored in multivariate models. RESULTS: Analysis included 2,679 individuals followed for a median of 11 months. Median CD4+ T-cell count at baseline was 85 cells/microl. Mean weight was 59 kg, mean age was 32 years and 71% were women. All started non-nucleoside reverse transcriptase inhibitor-based ART (60% on efavrienz) and 75% started on stavudine (d4T). After 3 years, 75% remained in care on-site, of whom 72% remained on their initial regimen. Substitutions due to toxicity of nevirapine (8% by 3 years), efavirenz (2%) and zidovudine (8%) occurred early. Substitutions on d4T occurred in 21% of patients by 3 years, due to symptomatic hyperlactataemia (5%), lipodystrophy (9%) or peripheral neuropathy (6%), and continued to accumulate over time. Those at greatest risk of hyperlactataemia or lipodystrophy were women on ART > or =6 months, weighing > or =75 kg at baseline. DISCUSSION: A high proportion of adult patients are able to tolerate their initial ART regimen for up to 3 years. In most instances treatment-limiting toxicities occur early, but continue to accumulate over time in patients on d4T. Whilst awaiting other treatment options, the risks of known toxicities could be minimized through early identification of patients at the highest risk.

Animal model for percutaneous creation of traumatic thoracic aortic transection

PURPOSE: This study was conducted to create an animal model for thoracic aortic transection that is suitable for thoracic endograft research. MATERIALS AND METHODS: Percutaneous aortic transection creation was attempted in 12 sheep. A custom collapsible circumferential cutting device was inserted into the proximal descending thoracic aorta via a femoral approach with an 11-F delivery catheter. The device was deployed 2 cm distal to the left subclavian artery origin and rotated 20 times to create aortic transection. Aortic diameters, mean aortic pressures, and heart rates were tested for degrees of difference between measurements before and after the creation of transection. On necropsy, the extent of aortic damage was classified as none, nontransmural, or transmural, and aortic transection was classified as none, partial, or circumferential. RESULTS: On angiography, creation of transmural thoracic aortic transection was successful in 91.7% (11/12) of animals. Aortic transection was circumferential in 54.4% (6/11) of animals and partial in 45.6% (5/11) of animals. Mean aortic diameter was 19.6 +/- 3.4 mm (range 12-24 mm) pre-transection and 25.8 +/- 4.5 mm (range 17.8-33 mm) post-transection (P = .0003). Pre-transection, mean aortic pressure was 79 +/- 13.8 mmHg, and 64.6 +/- 15.8 mmHg 15 min post-transection (P = .041). Pre-transection, mean heart rate was 94.5 +/- 17.2 beats per minute (bpm), and 105.8 +/- 17.2 bpm 15 min post-transection (P = .0057). CONCLUSIONS: Thoracic aortic transection was successfully created percutaneously in most animals. The animals remained in hemodynamically stable condition for as long as 240 minutes after the creation of aortic injury. This percutaneous animal model is straightforward and may be of potential value for future thoracic endograft research.

[Mason vertical gastroplasty in treatment of morbid obesity. Results of a prospective clinical study]

Morbid obesity (body mass index > 40 kg/m2) is a risk factor for cardiovascular, pulmonary, metabolic, neoplastic, and psychologic sequelae. In the present prospective clinical study 65 patients (11 men, 54 women) underwent vertical banded gastroplasty (Mason procedure) from June 1994 to October 1997. The median age was 41 +/- 5.3 years (range 18-69; n = 65). Preoperative body weight was 135 +/- 23 kg (96-229; n = 65), excess body weight in kg was 75 +/- 6.9 (44-155; n = 65) or in % 126 +/- 10 (78-223; n = 65) and BMI was 49 +/- 7.4 kg/m2 (39-69; n = 65). Mean hospital stay was 9.7 +/- 2.4 days (6-18; n = 65). Hospital mortality was 0% (0/65). Early complications were vomiting (30%) and problems in wound healing (15%; n = 65). Late complications (> 30 days) were incisional hernias (13.8%) and staple-line disruptions (12.3%; n = 65) with a reoperation rate of 23% (15/65). Median follow-up was 15.0 +/- 5.2 months (2-42) with a follow up rate of 100%. Mean weight loss after 12 months was 38.5 +/- 17 kg (30-98; n = 34) (P < 0.0001) and loss of excessive body weight 65 +/- 10% (57-86; n = 34), respectively (P < 0.0001). Cardiovascular risk factors (hypertension, diabetes, hyperlipidemia) were significantly improved within 12 months (n = 34). Vertical banded gastroplasty (Mason procedure)--well established for 20 years--is a good, safe therapy for morbid obesity if strict indications for operation are observed and if there is multidisciplinary long-term follow-up. Comorbid risk factors are considerably reduced and a long-term weight loss of more than 50% can be achieved without the risk of pathological metabolic changes.

Early percutaneous endoscopic gastrostomy insertion maintains nutritional state in patients with aerodigestive tract cancer

Patients with upper aerodigestive tract (UAT) cancers often suffer from malnutrition and compromised functional ability. We compared clinical outcome with percutaneous endoscopic gastrostomy (PEG) tube feeding begun at two different time points. The records of 151 patients with UAT carcinomas were reviewed retrospectively. We included patients undergoing radical radiochemotherapy and PEG tube feeding. Subjects were evaluated before PEG insertion and at the end of the treatment. Patients (n=15, 100%) were divided into two groups according to the presence (group A) or absence (group B) of mucositis. Group A (51.7% of patients) received early PEG: before or within 2 wk of radiotherapy. Group B (48.3%) received delayed PEG: between 2 wk and 3 mo after the start of radiotherapy. Mean weight loss was 1.03 kg in group A vs. 4.0 kg in group B, P=0.004. Treatment interruptions were significantly (P=0.01) more common in group B. Early PEG placement at the beginning of radiochemotherapy in patients with UAT tumors maintains the patient's nutritional state and reduces treatment interruptions.

Senile scleral plaques imaged with enhanced depth optical coherence tomography

PURPOSE Senile scleral plaques (SSP) are sharply demarcated greyish areas located just anterior to the insertions of the horizontal rectus muscles and thus are frequently encountered during transscleral intravitreal injections. The aim of this study was to characterize SSP using enhanced depth imaging spectral domain anterior segment optical coherence tomography (OCT) in a cohort of patients attending intravitreal injection clinics. METHODS Prospective cross-sectional study of 380 patients attending the clinic for intravitreal injections at the Department of Ophthalmology at the Bern University Hospital. Thirty-two patients with SSP were identified and the anatomical features were assessed using anterior segment OCT. RESULTS In our patient cohort, we found a SSP prevalence of 8.2%. Senile scleral plaques were easily identifiable using anterior segment OCT and were found at the insertion sites of the horizontal recti muscles. The mean horizontal diameter was 2.2 mm (±760 μm SD), the mean vertical diameter was 3.3 mm (±144 μm SD), and the average surface area was 5.3 mm(2) (±0.4 mm(2) SD). The mean senile scleral plaque thickness was 0.6 mm (±149 μm SD). The mean distance from the limbus was 2.24 mm for nasally located SSP and 3.22 mm for temporally located SSP. CONCLUSION SSP are frequently encountered during intravitreal injections as they are located just anterior to the insertion sites of the horizontal recti muscles. Because the scleral stroma is rarefied and due to calcifications within SSP, these areas should be avoided when performing multiple intravitreal injections as this may result in rupture of the sclera.

Morphological differentiation of Betula (birch) pollen in northwest North America and its palaeoecological application

Lake sediments from arcto-boreal regions commonly contain abundant Betula pollen. However, palaeoenvironmental interpretations of Betula pollen are often ambiguous because of the lack of reliable morphological features to distinguish among ecologically distinct Betula species in western North America. We measured the grain diameters and pore depths of pollen from three tree-birch species (B. papyrifera, B. kenaica and B. neoalaskana) and two shrub-birch species (B. glandulosa and B. nana), and calculated the ratio of grain diameter to pore depth (D/P ratio). No statistical difference exists in all three parameters between the shrub-birch species or between two of the tree-birch species (B. kenaica and B. papyrifera), and B. neoalaskana is intermediate between the shrub-birch and the other two tree-birch species. However, mean pore depth is significantly larger for the tree species than for the shrub species. In contrast, mean grain diameter cannot distinguish tree and shrub species. Mean D/P ratio separates tree and shrub species less clearly than pore depth, but this ratio can be used for verification. The threshold for distinguishing pollen of tree versus shrub birch lies at 2.55 μm and 8.30 for pore depth and D/P ratio, respectively. We'applied these thresholds to the analysis of Betula pollen in an Alaskan lake-sediment core spanning the past 800 years. Results show that shrub birch increased markedly at the expense of tree birch during the‘Little Ice Age’; this patten is not discernible in the profile of total birch pollen.

Radiographic volume analysis as a novel tool to determine nasopalatine duct cyst dimensions and its association with presenting symptoms and postoperative complications

OBJECTIVES The aims of the study were to use cone beam computed tomography (CBCT) images of nasopalatine duct cysts (NPDC) and to calculate the diameter, surface area, and 3D-volume using a custom-made software program. Furthermore, any associations of dimensions of NPDC with age, gender, presence/absence of maxillary incisors/canines (MI/MC), endodontic treatment of MI/MC, presenting symptoms, and postoperative complications were evaluated. MATERIAL AND METHODS The study comprised 40 patients with a histopathologically confirmed NPDC. On preoperative CBCT scans, curves delineating the cystic borders were drawn in all planes and the widest diameter (in millimeter), surface area (in square millimeter), and volume (in cubic millimeter) were calculated. RESULTS The overall mean cyst diameter was 15 mm (range 7-47 mm), the mean cyst surface area 566 mm(2) (84-4,516 mm(2)), and the mean cyst volume 1,735 mm(3) (65-25,350 mm(3)). For 22 randomly allocated cases, a second measurement resulted in a mean absolute aberration of ±4.2 % for the volume, ±2.8 % for the surface, and ±4.9 % for the diameter. A statistically significant association was found for the CBCT determined cyst measurements and the need for preoperative endodontic treatment to MI/MC and for postoperative complications. CONCLUSION In the hands of a single experienced operator, the novel software exhibited high repeatability for measurements of cyst dimensions. Further studies are needed to assess the application of this tool for dimensional analysis of different jaw cysts and lesions including treatment planning. CLINICAL RELEVANCE Accurate radiographic information of the bone volume lost (osteolysis) due to expansion of a cystic lesion in three dimensions could help in personalized treatment planning.

Biocompatibility assessment of the first generation PediaFlow pediatric ventricular assist device

The PediaFlow pediatric ventricular assist device is a miniature magnetically levitated mixed flow pump under development for circulatory support of newborns and infants (3-15 kg) with a targeted flow range of 0.3-1.5 L/min. The first generation design of the PediaFlow (PF1) was manufactured with a weight of approximately 100 g, priming volume less than 2 mL, length of 51 mm, outer diameter of 28 mm, and with 5-mm blood ports. PF1 was evaluated in an in vitro flow loop for 6 h and implanted in ovines for three chronic experiments of 6, 17, and 10 days. In the in vitro test, normalized index of hemolysis was 0.0087 ± 0.0024 g/100L. Hemodynamic performance and blood biocompatibility of PF1 were characterized in vivo by measurements of plasma free hemoglobin, plasma fibrinogen, total plasma protein, and with novel flow cytometric assays to quantify circulating activated ovine platelets. The mean plasma free hemoglobin values for the three chronic studies were 4.6 ± 2.7, 13.3 ± 7.9, and 8.8 ± 3.3 mg/dL, respectively. Platelet activation was low for portions of several studies but consistently rose along with observed animal and pump complications. The PF1 prototype generated promising results in terms of low hemolysis and platelet activation in the absence of complications. Hemodynamic results validated the magnetic bearing design and provided the platform for design iterations to meet the objective of providing circulatory support for young children with exceptional biocompatibility.

Seasonal variation and sources of low molecular weight organic acids in precipitation in the rural area of Anshun

Low mol. wt. (LMW) org. acids are important and ubiquitous chem. constituents in the atm. A comprehensive study of the chem. compn. of pptn. was carried out from June 2007 to June 2008 at a rural site in Anshun, in the west of Guizhou Province, China. During this period, 118 rainwater samples were collected and the main LMW carboxylic acids were detd. using ion chromatog. The av. pH of rainwater was 4.89 which is a typical acidic value. The most abundant carboxylic acids were formic acid (vol. wt. mean concn.: 8.77 μmol L-1) and acetic acid (6.90 μmol L-1), followed by oxalic acid (2.05 μmol L-1). The seasonal variation of concns. and wet deposition fluxes of org. acids indicated that direct vegetation emissions were the main sources of the org. acids. Highest concns. were obsd. in winter and were ascribed to the low winter rainfall and the contribution of other air pollution sources northeast of the study area. The ratio of formic and acetic acids in the pptn. ([F/A]T) was proposed as an indicator of pollution source. This suggested that the pollution resulted from direct emissions from natural or anthropogenic sources. Comparison with acid pptn. in other urban and rural areas in Guizhou showed that there was a decreasing contribution of LMW org. acids to free acidity and all anions in rainwater from urban to remote rural areas. Consequently, it is necessary to control emissions of org. acids to reduce the frequency of acid rain, esp. in rural and remote areas. [on SciFinder(R)]

Salt sensitivity of children with low birth weight

Compromised intrauterine fetal growth leading to low birth weight (<2500 g) is associated with adulthood renal and cardiovascular disease. The aim of this study was to assess the effect of salt intake on blood pressure (salt sensitivity) in children with low birth weight. White children (n=50; mean age: 11.3+/-2.1 years) born with low (n=35) or normal (n=15) birth weight and being either small or appropriate for gestational age (n=25 in each group) were investigated. The glomerular filtration rate was calculated using the Schwartz formula, and renal size was measured by ultrasound. Salt sensitivity was assigned if mean 24-hour blood pressure increased by >or=3 mm Hg on a high-salt diet as compared with a controlled-salt diet. Baseline office blood pressure was higher and glomerular filtration rate lower in children born with low birth weight as compared with children born at term with appropriate weight (P<0.05). Salt sensitivity was present in 37% and 47% of all of the low birth weight and small for gestational age children, respectively, higher even than healthy young adults from the same region. Kidney length and volume (both P<0.0001) were reduced in low birth weight children. Salt sensitivity inversely correlated with kidney length (r(2)=0.31; P=0.005) but not with glomerular filtration rate. We conclude that a reduced renal mass in growth-restricted children poses a risk for a lower renal function and for increased salt sensitivity. Whether the changes in renal growth are causative or are the consequence of the same abnormal "fetal programming" awaits clarification.

Body contouring surgery following bariatric surgery and dietetically induced massive weight reduction: a risk analysis

BACKGROUND: This study analyzed the impact of weight reduction method, preoperative, and intraoperative variables on the outcome of reconstructive body contouring surgery following massive weight reduction. METHODS: All patients presenting with a maximal BMI >/=35 kg/m(2) before weight reduction who underwent body contouring surgery of the trunk following massive weight loss (excess body mass index loss (EBMIL) >/= 30%) between January 2002 and June 2007 were retrospectively analyzed. Incomplete records or follow-up led to exclusion. Statistical analysis focused on weight reduction method and pre-, intra-, and postoperative risk factors. The outcome was compared to current literature results. RESULTS: A total of 104 patients were included (87 female and 17 male; mean age 47.9 years). Massive weight reduction was achieved through bariatric surgery in 62 patients (59.6%) and dietetically in 42 patients (40.4%). Dietetically achieved excess body mass index loss (EBMIL) was 94.20% and in this cohort higher than surgically induced reduction EBMIL 80.80% (p < 0.01). Bariatric surgery did not present increased risks for complications for the secondary body contouring procedures. The observed complications (26.9%) were analyzed for risk factors. Total tissue resection weight was a significant risk factor (p < 0.05). Preoperative BMI had an impact on infections (p < 0.05). No impact on the postoperative outcome was detected in EBMIL, maximal BMI, smoking, hemoglobin, blood loss, body contouring technique or operation time. Corrective procedures were performed in 11 patients (10.6%). The results were compared to recent data. CONCLUSION: Bariatric surgery does not increase risks for complications in subsequent body contouring procedures when compared to massive dietetic weight reduction.

Lung growth after experimental pulmonary transplantation

Replacement of the heart and both lungs or single lung transplantation has been performed in a few cases of terminal (cardio) pulmonary disease in childhood. It remains unclear whether pulmonary allografts will meet the demands of a growing organism. Six domestic pigs (mean body weight, 24 kg) underwent left lung transplantation from donors of equal weight. Immunosuppression consisted of cyclosporine, azathioprine, and corticosteroids. After the pigs doubled their body weight, growth of the lung was assessed by bronchography and pulmonary angiography. In transplant animals it took 11 weeks (normal animals, 6 weeks) for their weight to double. At that time, the bronchial tree showed similar growth when compared with nontransplant animals of equal weight. The diameter of the left lower lobe bronchus (9.2 +/- 0.4 mm) was significantly greater than that of animals of 24 kg body weight (7.5 +/- 0.3 mm; p less than 0.01) but comparable to that of normal pigs of similar weight (9.0 +/- 0.5 mm). The same applied for length of the left lower lobe bronchus (transplants, 95 +/- 6.7 mm; controls 24 kg, 67 +/- 2 mm [p less than 0.01]; controls 48 kg, 93 +/- 3 mm). Similar growth tendencies were observed in the pulmonary vascular tree. The diameter of the left lower lobe artery was 9.4 +/- 98 mm in 48 kg transplant pigs, compared with 9.7 +/- 1.2 mm in 24 kg control pigs and 8.5 +/- 0.8 mm in 48 kg control pigs. In one case of recurrent severe pulmonary rejection, the lung did not grow. We conclude from this study that growth is retarded by immunosuppression.(ABSTRACT TRUNCATED AT 250 WORDS)

Is body weight the most appropriate criterion to select patients eligible for low-dose pulmonary CT angiography? Analysis of objective and subjective image quality at 80 kVp in 100 patients

The objective of this retrospective study was to assess image quality with pulmonary CT angiography (CTA) using 80 kVp and to find anthropomorphic parameters other than body weight (BW) to serve as selection criteria for low-dose CTA. Attenuation in the pulmonary arteries, anteroposterior and lateral diameters, cross-sectional area and soft-tissue thickness of the chest were measured in 100 consecutive patients weighing less than 100 kg with 80 kVp pulmonary CTA. Body surface area (BSA) and contrast-to-noise ratios (CNR) were calculated. Three radiologists analyzed arterial enhancement, noise, and image quality. Image parameters between patients grouped by BW (group 1: 0-50 kg; groups 2-6: 51-100 kg, decadally increasing) were compared. CNR was higher in patients weighing less than 60 kg than in the BW groups 71-99 kg (P between 0.025 and <0.001). Subjective ranking of enhancement (P = 0.165-0.605), noise (P = 0.063), and image quality (P = 0.079) did not differ significantly across all patient groups. CNR correlated moderately strongly with weight (R = -0.585), BSA (R = -0.582), cross-sectional area (R = -0.544), and anteroposterior diameter of the chest (R = -0.457; P < 0.001 all parameters). We conclude that 80 kVp pulmonary CTA permits diagnostic image quality in patients weighing up to 100 kg. Body weight is a suitable criterion to select patients for low-dose pulmonary CTA.