Public attitudes to organ donation among a sample of urban-dwelling South African adults: a 2012 study.

BACKGROUND: Published literature suggests that attitudes toward organ donation in South Africa are generally positive. However, there has been a decline in the actual number of transplants taking place annually, which is not consistent with expressed positive attitudes. OBJECTIVES: Assess the attitudes of a representative sample of the urban-dwelling South African population toward organ donation and how these might affect transplant numbers. METHODS: A structured questionnaire was utilized to measure attitudes among a study population of 1048 adults in five major metropolitan areas of South Africa. Field work was undertaken by supervised field workers. Written informed consent was obtained from all participants. RESULTS: Eighty-nine percent (89%) of respondents had heard of organ donation, and 77% indicated that they would accept an organ transplant if necessary. Seventy percent (70%) of respondents specified they would be willing to donate their own organs after death, while 67% expressed willingness to donate a relative's organs after death. Participants were more positive about kidney donation than any other organ. CONCLUSION: Public attitudes toward organ donation among this population are generally positive. Recommendations include cultural and linguistic sensitivity in educational and advertising campaigns, as well as extensive research into other possible causes of organ shortage.

Estuarine influences on a continental shelf plankton community.

On the southeastern U.S. continental shelf, phytoplankton primary production and the densities of zooplankton, fish eggs, and fish larvae peak simultaneously in late summer and early fall. Some community response to irregular storm events is observed. However, the gross plankton community dynamics on this shelf are dominated by couplings with the local estuaries and shallow nearshore zone.

Predicting summer hypoxia in the northern Gulf of Mexico: riverine N, P, and Si loading.

We conducted a statistical analysis to discern the relative strengths of the loading of various forms of nitrogen, phosphorus, dissolved silicate and their molar ratios on the variance in the size of the summertime low oxygen zone found off the Mississippi River, northern Gulf of Mexico. A stable statistical model that included Year and riverine nitrate+nitrite loading for the 2 months prior to the measurement of hypoxic zone size described 82% of its variation in size from 1978 to 2004. The usefulness of the term Year is consistent with the documented increase in carbon stored in sediments after the 1970s, which is when the hypoxic zone is predicted to have become a regular feature on the shelf and to have expanded westward. The increased carbon storage is anticipated to cause a sedimentary respiratory demand influencing the size of the zone, and whose temporal influence is cumulative and transcends the annual variations in nitrogen loading. The variable Year is negatively correlated with the TN:TP ratio in a way that suggests N, not P, has become more important as a factor limiting phytoplankton growth in the last 20 years. Nitrogen, in particular nitrate+nitrite, and not phosphorus, dissolved silicate, or their molar ratios, appears to be the major driving factor influencing the size of the hypoxic zone on this shelf. This conclusion is consistent with cross-system analyses that conclude that the TN:TP ratio in the Mississippi River, currently fluctuating around 20:1, is indicative of nitrogen, not phosphorus, limitation of phytoplankton growth. Nutrient management that places stronger emphasis on reducing nitrogen loading as compared to phosphorus loading, is justified.

Summer hypoxia in the northern Gulf of Mexico and its prediction from 1978 to 1995.

An 18-year monitoring record (1978-1995) of dissolved oxygen within a region having hypoxia (dissolved oxygen less than 2 mgl(-1)) in the bottom layer was examined to describe seasonal and annual trends. The monitoring location was near or within a well-described summer hypoxic zone whose size has been up to 20,000 km(2). The monitoring data were used to hindcast the size of the hypoxic zone for before consistent shelfwide surveys started, and to predict it for 1989, when a complete shelfwide survey was not made. The concentration of total Kjeldahl nitrogen (TKN) in surface waters and concentration of bottom water oxygen were directly related, as anticipated if organic loading from surface to bottom was from in situ processes. The TKN data were used to develop a predictive relationship that suggested there was no substantial hypoxia before the 1970s, which was before nitrate flux from the Mississippi River to the Gulf of Mexico began to rise. The peak frequency in monthly hypoxic events is two to three months after both the spring maximum in discharge and nitrate loading of the Mississippi River. These results support the conclusion that persistent, large-sized summer hypoxia is a recently-developed phenomenon that began in the 1970s or early 1980s.

Phytoplankton and the Macondo oil spill: A comparison of the 2010 phytoplankton assemblage to baseline conditions on the Louisiana shelf.

The Macondo oil spill was likely the largest oil spill to ever occur in United States territorial waters. We report herein our findings comparing the available baseline phytoplankton data from coastal waters west of the Mississippi River, and samples collected monthly from the same sampling stations, during and after the oil spill (May-October, 2010). Our results indicate that overall, the phytoplankton abundance was 85% lower in 2010 versus the baseline, and that the species composition of the phytoplankton community moved towards diatoms and cyanobacteria and away from ciliates and phytoflagellates. The results of this study reaffirm the view that phytoplankton responses will vary by the seasonal timing of the oil spill and the specific composition of the spilled oil. The trophic impacts of the purported lower abundance of phytoplankton in 2010 coupled with the observed assemblage shift remain unknown.

The clinical presentation of command hallucinations in a forensic population.

In a forensic population, patients with command hallucinations (N = 25) were compared to two groups of psychotic patients: those with noncommand hallucinations (N = 24) and those without hallucinations (N = 16). The three groups did not differ in overall impairment as measured by the Global Assessment Scale and the Social Behavior Rating Schedule. However, the group with command hallucinations differed in the content of their hallucinations (more aggression, dependency, and self-punishment themes), and nearly one-half did not report or denied their command hallucinations to the assessment team. Many patients (N = 11, 44%) reported that they frequently responded to hallucinatory commands with unquestioning obedience.

A prospective study of Raynaud phenomenon and early connective tissue disease. A five-year report.

To define features of patients with Raynaud phenomenon that predict the evolution of connective tissue disorders, a prospective study was initiated. Patients with history or physical evidence of Raynaud phenomenon without causal or associated disorders underwent initial multisystem evaluation. Scleroderma (systemic sclerosis) of less than five years' duration was included for comparison. Patients were classified as having Raynaud phenomenon "only," undifferentiated connective tissue syndrome or scleroderma. Nailfold capillary microscopy was performed, and patterns were scored blindly from coded photographs. Of 91 patients with Raynaud phenomenon entered (Raynaud phenomenon only, n = 49; undifferentiated connective tissue syndrome, n = 22; scleroderma, n = 20), abnormal "scleroderma pattern" capillaries were noted in seven of 49, 19 of 22 and 19 of 20, respectively (p less than 0.005). Of 39 patients with Raynaud phenomenon only followed (mean duration, 23.7 months) undifferentiated connective tissue syndrome developed in three. Of 17 patients with undifferentiated connective tissue syndrome followed (mean duration, 27.6 months), six patients had transitions (four scleroderma; one scleroderma-systemic lupus erythematosus overlap; one SLE). Nailfold capillary abnormalities best identified transitional patients in both groups (eight of nine) and were more sensitive than ANA (six of nine), presence of digital ulcers (four of nine) or decreased esophageal motility (two of nine). This prospective study documents a useful role for capillary examinations in evaluating Raynaud phenomenon. Abnormal capillaries indicate an increased risk for connective tissue disease; normal capillaries favor idiopathic Raynaud phenomenon.

Esophageal pressure measurements in cardiopulmonary exercise testing.

STUDY OBJECTIVES: We sought to determine the adaptability and effectiveness of a new esophageal balloon technique to measure changes in esophageal pressure (Pes) as a reflection of pleural pressure with progressive incremental exercise testing in normal subjects. DESIGN: An 8F (0.9 cm) esophageal balloon catheter (Smart Cath; Allied Health Products; Riverside, Calif), a CP-100 pulmonary monitor (BiCore Monitoring Systems PC-100; Irvine, Calif), and a flow transducer (Var flex; Allied Health Products; Riverside, Calif) were connected to a breathing valve (model 2700; Hans-Rudolph Inc; Kansas City, Mo). This apparatus was then used to measure Pes during a graded cardiopulmonary exercise test (CPX) to symptom limitation. SETTING: University-affiliated Veterans Affairs Hospital. PARTICIPANTS: Eight nonsmoking volunteers with normal results of pulmonary function tests. INTERVENTIONS: Plots of deltaPes against pressure time product (PTP), minute ventilation (VE), and oxygen consumption (VO2) were obtained. Pes at baseline, anaerobic threshold (AT), and maximum oxygen consumption (VO2max) were obtained by comparing the Pes measurements from the computer printout to the corresponding breath-by-breath measurements on the CPX. MEASUREMENTS AND RESULTS: The flow transducer (Varflex) connection added only 20 mL of dead space to the standard mouthpiece apparatus. The mean maximum work performance was 203+/-32 W. The mean VO2max was 29+/-9 mL/kg/min. The Pes at AT was 16+/-3 cm H2O. The Pes at maximal exercise was 42+/-16 cm H2O. CONCLUSION: The small esophageal balloon was well tolerated by all subjects. Plots of deltaPes vs PTP, VE, and VO2 demonstrated a linear correlation. This apparatus could be added to the standard CPX to assess the contribution of the diaphragm and respiratory muscles in patients with dyspnea.

Noninvasive positive pressure ventilation in status asthmaticus.

OBJECTIVE: In asthmatic patients with acute respiratory failure (ARF), placing an endotracheal tube is associated with a high rate of complications and results in increased airway resistance. In acute asthma, mask-continuous positive airway pressure (CPAP) decreases airway resistance and the work of breathing (WOB), but does not improve gas exchange. In COPD with ARF, adding intermittent positive pressure ventilation to mask-CPAP results in an additional improvement in WOB and is highly effective in correcting gas exchange abnormalities. In our medical ICU, noninvasive positive pressure ventilation (NPPV) is used as first-line interventional therapy in eligible patients with hypercapnic ARF. We report our experience with NPPV in 17 episodes of asthma and ARF over a 3-year period. METHODS: A face mask was secured with head straps, avoiding a tight fit, and connected to a ventilator (PB-7200). Initial ventilatory settings included CPAP at 4 +/- 2 cm H2O to offset intrinsic positive end-expiratory pressure and pressure support ventilation (PSV) at 14 +/- 5 cm H2O aiming at a respiratory rate less than 25 breaths/min and an exhaled tidal volume of 7 mL/kg or more. PSV was then adjusted following arterial blood gas results. RESULTS: Mean age was 35.4 +/- 11.3 years; 10 patients were female. The mean (+/- SE) for different physiologic values are reported at initiation, less than 2 h, 2 to 6 h, and 12 to 24 h into NPPV. pH was 7.25 +/- 0.01, 7.32 +/- 0.02 (p = 0.0012), 7.36 +/- 0.02 (p < 0.0001), and 7.38 +/- 0.02; PaCO2 was 65 +/- 2, 52 +/- 3(p = 0.002), 45 +/- 3(p < 0.0001), and 45 +/- 4; PaO2 fraction of inspired oxygen was 315 +/- 41, 403 +/- 47, 367 +/- 47, and 472 +/- 67 (p = 0.06); and respiratory rate was: 29.1 +/- 1, 22 +/- 1 (p < 0.0001), 20 +/- 1, and 17 +/- 1. NPPV was well tolerated, and only two patients required sedation. Initial delivered minute ventilation was 16 +/- 4 L/min. The mean (+/- SD) peak inspiratory pressure to ventilate in the NPPV-treated patients was 18 +/- 5 cm H2O and always less than 25 cm H2O. There was no complication or problem with expectorating of secretions. Oral intake (liquid diet) was preserved. Two patients required intubation (35 min and 89 h into NPPV) for worsening PaCO2. Duration of NPPV was 16 +/- 21 h. All patients survived. Length of hospital stay was 5 +/- 4 days. CONCLUSIONS: In asthmatic patients with ARF, NPPV via a face mask appears highly effective in correcting gas exchange abnormalities using a low inspiratory pressure (< 25 cm H2O). A randomized study is in progress to assess fully the role of NPPV in status asthmaticus.

Noninvasive positive pressure ventilation via face mask. First-line intervention in patients with acute hypercapnic and hypoxemic respiratory failure.

OBJECTIVES: We have previously reported our experience with noninvasive positive pressure ventilation (NPPV) via face mask in a small group of selected patients with acute respiratory failure (ARF). NPPV was frequently effective (70% success rate) in correcting gas exchange abnormalities and in avoiding endotracheal intubation (ETI); NPPV also had a low rate of complications. We have evaluated the clinical application of NPPV as first-line intervention in patients with hypercapnic and short-term hypoxemic ARF. A dedicated respiratory therapist conducted an educational program with physicians-in-training rotating through the medical ICUs of a university medical center and supervised implementation of a simplified management protocol. Over 24 months, 164 patients with heterogeneous forms of ARF received NPPV. We report on the effectiveness of NPPV in correcting gas exchange abnormalities, in avoiding ETI, and associated complications, in different conditions precipitating ARF. PATIENT POPULATION: One hundred fifty-eight patients completed the study. Forty-one had hypoxemic ARF, 52 had hypercapnic ARF, 22 had hypercapnic acute respiratory insufficiency (ARI), 17 had other forms of ARF, and 26 with advanced illness had ARF and refused intubation. Twenty-five percent of the patients developed ARF after extubation. INTERVENTION: Mechanical ventilation was delivered via a face mask. Initial ventilatory settings were continuous positive airway pressure (CPAP) mode, 5 cm H2O, with pressure support ventilation of 10 to 20 cm H2O titrated to achieve a respiratory rate less than 25 breaths/min and an exhaled tidal volume of 7 mL/kg or more. Ventilator settings were adjusted following arterial blood gases (ABG) results. RESULTS: The mean duration of NPPV was 25 +/- 24 h. When the 26 patients with advanced illness are excluded, NPPV was effective in improving or correcting gas exchange abnormalities in 105 patients (80%) and avoiding ETI in 86 (65%). Failure to improve ABG values was the reason for ETI in 20 of 46 (43%). The overall average predicted and actual mortality were 32% and 16%, respectively. Survival was 93% in non-intubated patients and 79% in intubated patients. NPPV was effective in lessening dyspnea throughout treatment in all but seven patients. Complications developed in 24 patients (16%). In patients with hypercapnic ARF, nonresponders had a higher PaCO2 at entrance (91.5 +/- 4.2 vs 80 +/- 1.5; p < 0.01). In patients with hypercapnic ARF and ARI, arterial blood gases response (pH and PaCO2) within 2 h of NPPV predicted success (p < 0.0001). None of the entrance parameters predicted need for ETI. CONCLUSIONS: We conclude that application of NPPV in clinical practice is an effective and safe alternative to ETI in many hemodynamically stable patients with hypercapnic ARF and in those with hypoxemic ARF in whom the clinical condition can be readily reversed in 48 to 72 h. An educational and supervision program is essential to successfully implement this form of therapy.

Separation and purification of recombinant proteins from Escherichia coli with aqueous two-phase systems.

The partition of the protein thaumatin in the presence of Escherichia coli contaminant proteins has been studied. Extraction of thaumatin was followed by back-extraction of the product into a new phosphate phase and also back extraction combined with recycle of the top polyethylene glycol (PEG) phase. When partitioned in the absence or presence of insoluble cell debris (whole cell homogenate) little effect on the partitioning of thaumatin or the soluble E. coli protein was observed. A back extraction step that allowed for dilution of the NaCl was successful in extracting thaumatin back into a heavy phosphate phase. The PEG top phase was recycled to the first extraction stage. The stability ratio (tie-line length) had an effect on the average partition coefficient (Kapp) of E. coli soluble proteins in PEG-phosphate systems but in PEG sulphate systems Kapp was independent of this ratio. An increase in NaCl resulted in an increase in Kapp but this was always below 1. A mathematical model that describes the continuous steady-state operation of extraction and back extraction has been developed; it is based on steady state mass balances of the main components and phase equilibrium data and was successfully used to simulate the extraction and back extraction processes.

Computer-based simulations enhance clinical experience of dietetics interns.

OBJECTIVE: To determine the impact of computer-based simulations on the performance of dietetics interns in initial clinical rotations. DESIGN: Interns used either a simulation program (Care Planning Simulation System CPSS[) or a computer-based tutorial (Nutrition Care Planning Tutorial NCPT[) during their orientation. Performance of these interns on nutrition care skills was evaluated during their initial clinical rotations. SUBJECTS/SETTING: Participants were 108 dietetics interns from 8 different programs. Each internship had at least 8 interns, and none of the internships awarded a graduate degree. INTERVENTION: Subjects in the experimental group completed nutrition assessment and care planning activities for 3 simulated patients. Subjects in the control group completed a tutorial on assessment and care planning. MAIN OUTCOME MEASURES: Likert scale ratings of 31 behaviors were recorded by clinical preceptors. Behavior statements were grouped into 8 categories and average ratings for each category were determined. STATISTICAL ANALYSIS: Repeated-measures analysis of variance and linear regression were used to compare performance ratings between groups. RESULTS: There were no differences in overall evaluations of the simulation and tutorial groups for the 8-week period. Interns who started clinical rotations immediately after orientation (CPSS-I and NCPT-I groups) were rated lower in all categories than those who began their clinical rotations later (CPSS-D and NCPT-D groups). Maturation and acquisition of general skills likely influenced ratings of interns with delayed clinical rotations. For most categories of behavior the rate of improvement in rating scores was greatest for interns who used CPSS. APPLICATIONS: Computer-based simulations are a promising supplement to current techniques in didactic instruction and may be useful in both didactic and practice settings. Computer-based simulations can provide more varied practice experiences to didactic students and interns in preparation for more skilled entry-level positions in dietetics.

Erythrocyte sedimentation, viscosity, and plasma proteins in disease detection.

In order to assess the relationships of erythrocyte sedimentation rates (ESR) and various acute phase reactants in diagnosing and following the remissions and exacerbations of various chronic diseases, multiple tests were performed on patients for whom an ESR was ordered. The Wintrobe and Westergren ESR, plasma and serum viscosity, hemoglobin, blood cell indices, fibrinogen, serum protein electrophoresis, triglycerides, and complement (C-3) were performed. A discussion of the relative merits of correcting the Wintrobe ESR by the Wintrobe anemia correction chart of the Hynes and Whitby method is presented. Although many significant correlations exist, only the Wintrobe and Westergren ESRs and plasma viscosity approached the same number of abnormal results. If the results of the Wintrobe and Westergren are combined 67 abnormal results are observed. The plasma viscosity exhibited a 10.4 percent false positive rate compared to the combined ESR's and a 6.0 percent false negative rate. The plasma viscosity was not only highly significantly correlated with the ESR's (P < < 0.001), but also with all acute phase reactants measured as well as total protein, albumin, and gamma-globulin. The plasma viscosity appears to give the best overall summation of the many non-specific changes observed in chronic disease.

Focusing x-ray spectrograph for laser fusion experiments.

X-ray spectra from laser fusion targets are normally measured with flat crystal (nonfocusing) spectrographs. We describe here the characteristics of a focusing spectrograph which is capable of recording wide band spectra with significantly higher sensitivity. Measuring spectra in the (10-11) A range from glass microballoons imploded by a two-beam Nd:Glass laser system we find intensity per unit area on film about 100 times higher with a curved mica than with a flat mica spectrograph.

Hypoxia in the Gulf of Mexico.

Seasonally severe and persistent hypoxia, or low dissolved oxygen concentration, occurs on the inner- to mid-Louisiana continental shelf to the west of the Mississippi River and Atchafalaya River deltas. The estimated areal extent of bottom dissolved oxygen concentration less than 2 mg L-1 during mid-summer surveys of 1993-2000 reached as high as 16,000 to 20,000 km2. The distribution for a similar mapping grid for 1985 to 1992 averaged 8000 to 9000 km2. Hypoxia occurs below the pycnocline from as early as late February through early October, but is most widespread, persistent, and severe in June, July, and August. Spatial and temporal variability in the distribution of hypoxia exists and is, at least partially, related to the amplitude and phasing of the Mississippi and Atchafalaya discharges and their nutrient flux. Mississippi River nutrient concentrations and loadings to the adjacent continental shelf have changed dramatically this century, with an acceleration of these changes since the 1950s to 1960s. An analysis of diatoms, foraminiferans, and carbon accumulation in the sedimentary record provides evidence of increased eutrophication and hypoxia in the Mississippi River delta bight coincident with changes in nitrogen loading.

Solar particle events and the International Space Station.

The high inclination orbit for the International Space Station poses a risk to astronauts on EVA during occasional periods of enhanced high energy particle flux from the sun known as Solar Particle Events. We are currently unable to predict these events within the few-hour lead time required for evasive action. Compounding the threat is the fact that station construction occurs during increasing solar activity and through the peak of the solar cycle. In this paper we present an overview of the risk, the current methods to provide forecasts of SPEs, and potential risk mitigation options.

Orbit selection and its impact on radiation warning architecture for a human mission to Mars.

With the recent announcement of the discovery of the possibility of life on Mars, there is renewed interest in Mars missions, perhaps eventually in human missions. Astronauts on such missions are at risk to occasional periods of enhanced high energy particle flux from the sun known as Solar Particle Events. These events can pose a substantial risk to the health of the astronauts and to the on-board electronics. Effective forecast and warning of these events could provide time to take steps to minimize the risk (retreating to a safe haven, shutting down sensitive equipment, etc.) Providing that forecast capability, will require additional monitoring capability. The extent of this architecture is sensitive to the orbit selected for the transfer to and from Mars. This paper looks at the major classes of Mars missions (Conjunction and Opposition) and sub-categories of these classes and draws conclusions on the number of monitoring satellites needed for each, with a goal to reducing total system cost through optimum orbit selection.

Attitudes to organ donation among some urban South African populations remain unchanged: a cross-sectional study (1993 - 2013).

BACKGROUND: A 1993 paper in the SAMJ suggested that public attitudes to organ donation in South Africa were positive. However, statistics reveal a decline in the annual number of transplants in this country. OBJECTIVE: To repeat the 1993 survey as far as possible and determine whether public attitudes to organ donation in some South African populations have changed over the past 20 years. METHODS: The 1993 study was replicated in 2012 to generate a current data set. This was compared with the raw data from the 1993 study, and an analysis of percentages was used to determine variations. RESULTS: Generally attitudes to organ donation have not changed since 1993, remaining positive among the study population. However, individuals are significantly more hesitant to consider donating the organs of a relative without being aware of that person's donation preference. Individuals in the black African study population are currently more willing to donate kidneys than in 1993 (66% v. 81%; p < 0.0001), but less willing to donate a heart (64% v. 38%; p < 0.0001), a liver (40% v. 34%; p < 0.036) and corneas (22% v. 15%, p < 0.0059). CONCLUSIONS: Publicity campaigns aimed at raising awareness of organ donation should emphasise the importance of sharing donation preferences with one's family in order to mitigate discomfort about making a decision on behalf of another. These campaigns should be culturally and linguistically sensitive. The study should be repeated in all populations over time to continually gauge attitudes.