Retrospective study of the diagnostic criteria in a lead-poisoning survey of waterfowl

A review of childhood injuries at the Wesley Guild Hospital, a component of Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, Nigeria, showed that 1,471 patients seen in the children's emergency room during a period of 4 years (1992-1995) were there as a result of trauma, representing 9% of all patients seen. The case notes and accident and emergency cards of 1,224 were available for review. Ages ranged from 2 months to 15 years, with a mean of 6.9 years, and 40% of the patients were between 5 and 10 years of age. More males were affected than females, with a ratio of 1.5:1. Road traffic crashes were the most common causal factor, responsible for 324 injuries (26.5%). About 90% of these were pedestrians knocked down by automobiles and motorcycles. Passengers accounted for about 10% of the cases. Falls occurred in 305 patients (25%); 229 patients fell while on level ground either playing or running, accounting for 75%. There were 122 patients (10%) with misplaced foreign bodies; about 60% of these were recovered from the ears, and 26.3% from the nostrils. Edible seeds were the most common foreign bodies, followed by beads. Injuries from bites occurred in 108 patients, with dog and snake bites taking the lead. Burns, mainly from scalding, occurred in 89 patients. Other rare injuries were knife wounds, gunshot wounds, and injuries resulting from assaults. The home was the most common site of injury (570 patients, 46.7%) followed by streets or roadways (363 patients, 29.7%); 19.5% of injuries occurred at school. The most common anatomic region affected was the head and neck, followed by the limbs. One hundred ninety-seven patients (16%) had bony fractures, femurs being the most affected bone. Head injury was seen in 104 patients, representing 8.5%, although only 17 of these injuries were severe. There were 10 cases of abdominal injury and 9 cases of chest injury, representing 0.8 and 0.7%, respectively. Wound infection occurred in 6.4% of the patients. Death occurred in 19 patients, accounting for 1.6%; 10 of these patients had severe head injuries. Road traffic injuries and burns accounted for the greatest number of complications. The findings of this study suggest that trauma is an important factor in childhood morbidity and mortality in our environment, with road traffic injuries taking the lead. Preschool pedestrian children were most commonly affected, the majority of them on errands for their parents. We believe that the majority of these injuries are preventable.     

Antibiotic-resistant enterococci and the changing face of surgical infections

The use of linear peptides as antigens for detection of serum antibodies has been studied using a sequence of the Borrelia burgdorferi protein, flagellin, and Lyme disease sera as a model. It was found that a novel presentation of the peptide as a hapten on the carrier protein, bovine serum albumin, in the enzyme-linked immunosorbent assay format can be successfully applied to distinguish between Lyme disease and control sera.     

Proof of soundness (integrity) of cryptographic protocols

In 1990 a workshop on the Mathematical Concepts (or Principles) of Dependable Systems was held at the Mathematisches Forschungsinstitut Oberwolfach in Germany. The purpose of the workshop was to examine mathematical techniques developed to make it possible to prove the proper functioning of complex systems—where the system could be either hardware, software, information protocols, etc., or combinations of these components. Principal researchers in each of these areas were invited to take part in the workshop, and did—but as is so often the case at scientific meetings, one area emerged as a clear center of gravity for the workshop. This was the topic of applying formal methods to the proof of soundness or correctness of information or cryptographic protocols. The organizers of the workshop felt that the results reported in this area were so important to the cryptology community they deserved publication as a whole, as opposed to publication as separate and isolated papers: hence this special section. This paper, which is essentially an introduction for the invited paper that follows, describes the background for the workshop and the challenge problem(s) that provided a unifying theme for the three systems of formal analysis treated in it.For reasons beyond the control of either the authors or the editors, this special section has been unusually long delayed in publication; so long in fact that a great deal of related work has been done in the interim. It would have been desirable to summarize these developments in this preface, but this would have changed the nature of the preface from a brief note describing the circumstances that led to the invitation to the authors to prepare the paper that makes up the special section, to a full fledged survey paper in itself. After careful consideration, it was decided that this would be inconsistent with the original intent for the special section.     

Application of the Peristaltic in Vitro Assembly to Gastric Acid Neutralization by Liquid Antacids: a Preliminary Report

The utility of the peristaltic in vitro assembly is further demonstrated in a gastric acid neutralization study involving a liquid antacid formulation, a placebo and a group of hypersecretory subjects. By adding an acid delivery system to the assembly to simulate gastric acid secretion and using dilute hydrochloric acid as the reaction medium, hydrogen ion concentration-time plots were obtained which were comparable to their in vivo counterparts.     

Use of Steel Slag Leach Beds for the Treatment of Acid Mine Drainage

Steel slag from the Waylite steel-making plant in Bethlehem, Pennsylvania was leached with acidic mine drainage (AMD) of a known quality using an established laboratory procedure. Leaching continued for 60 cycles and leachates were collected after each cycle. Results indicated that the slag was very effective at neutralizing acidity. The AMD/slag leachates contained higher average concentrations of Ba, V, Mn, Cr, As, Ag, and Se and lower average concentrations of Sb, Fe, Zn, Be, Cd, Tl, Ni, Al, Cu, and Pb than the untreated AMD. Based on these tests, slag leach beds were constructed at the abandoned McCarty mine site in Preston County, West Virginia. The leach beds were constructed as slag check dams below limestone-lined settling basins. Acid water was captured in limestone channels and directed into basins to leach through the slag dams and discharge into a tributary of Beaver Creek. Since installation in October 2000, the system has been consistently producing net alkaline, pH 9 water. The treated water is still net alkaline and has a neutral pH after it encounters several other acidic seeps downstream.     

Release of reduced inorganic selenium species into waters by the green fresh water algae Chlorella vulgaris

The common green fresh water algae Chlorella vulgaris was exposed to starting concentrations of 10 μg/L selenium in the form of selenate, selenite, or selenocyanate (SeCN(-)) for nine days in 10% Bold's basal medium. Uptake of selenate was more pronounced than that of selenite, and there was very little uptake of selenocyanate. Upon uptake of selenate, significant quantities of selenite and selenocyanate were produced by the algae and released back into the growth medium; no selenocyanate was released after selenite uptake. Release of the reduced metabolites after selenate exposure appeared to coincide with increasing esterase activity in solution, indicating that cell death (lysis) was the primary emission pathway. This is the first observation of biotic formation of selenocyanate and its release into waters from a nonindustrial source. The potential environmental implications of this laboratory observation are discussed with respect to the fate of selenium in impacted aquatic systems, the ecotoxicology of selenium bioaccumulation, and the interpretation of environmental selenium speciation data generated, using methods incapable of positively identifying reduced inorganic selenium species, such as selenocyanate.     

Damage evolution in polymer due to exposure to high-pressure hydrogen gas

The use of hydrogen as a fuel is increasing exponentially, and the most economical way to store and transport hydrogen for fuel use is as a high-pressure gas. Polymers are widely used for hydrogen distribution and storage systems because they are chemically inert towards hydrogen. However, when exposed to high-pressure hydrogen, some hydrogen diffuses through polymers and occupies the preexisting cavities inside the material. Upon depressurization, the hydrogen trapped inside polymer cavities can cause blistering or cracking by expanding these cavities. A continuum mechanics–based deformation model was deployed to predict the stress distribution and damage propagation while the polymer undergoes depressurization after high-pressure hydrogen exposure. The effects of cavity size, cavity location, and pressure inside the cavity on damage initiation and evolution inside the polymer were studied. The stress and damage evolution in the presence of multiple cavities was also studied, because interaction among cavities alters the damage and stress field. It was found that all these factors significantly change the stress state in the polymer, resulting in different paths for damage propagation. The effect of adding carbon black filler particles and plasticizer on the damage was also studied. It was found that damage tolerance of the polymer increases drastically with the addition of carbon black fillers, but decreases with the addition of the plasticizer.     

Does the "Thunderbirds syndrome" still exist

Rationing of resources within both the private and public health care systems is a fact of life. The Thunderbirds TV series encapsulated an idealistic philosophy that life should be saved independent of the pecuniary cost. Doctors, in particular, are trapped between their role as advocates for the patient within the "Thunderbirds" philosophy and as citizens with a responsibility to use resources wisely. This dichotomy is challenged by point of care rationing, which can conflict with clinical responsibilities, undermines the patient-doctor relationship and is often undertaken in a clandestine manner. This form of controlling health costs is difficult to justify from an ethical perspective, particularly when other forms of health care rationing and expenditure are frequently modulated by political expediency and inadequate economic modelling. Indeed, focusing on improving quality and disease prevention, rather than reducing marginal costs can often control the long-term growth in health expenditure. Doctors have a responsibility to ensure that rationing decisions are made but these should be made as part of a transparent, evidence-based and democratic process away from the point of care. While the resources to implement the "Thunderbirds Syndrome" have never been available, the philosophy must remain at the heart of patient-doctor relationship.     

Inhibitory effect of alkylating modulators on the function of P-glycoprotein

Modulators of P-glycoprotein (P-gp) are often themselves transported out of cells, thereby limiting their effectiveness. It may be possible to develop more effective modulators of multidrug resistance by designing drugs that irreversibly block the function of P-gp. Therefore, we studied the effect of the mustard derivatives of fluphenazine (FPN) and trans-flupenthixol (FPT) on P-gp function. Both fluphenazine-mustard (FPN-M) and trans-flupenthixol-mustard (FPT-M) possessed alkylating activity, as assayed using 4-(p-nitrobenzyl) pyridine. Multidrug-resistant MCF-7/AdrR cells were incubated with FPN or FPN-M, or FPT or FPT-M for 1 h, washed for varying number of times in phosphate-buffered saline (PBS), then resuspended in medium containing [3H]vinblastine (VBL), and assayed for steady-state accumulation of the drug. Washing had far less of an effect on the ability of FPN-M and FPT-M to increase VBL accumulation compared to their parent compounds. After eight washes in excess PBS, the cells initially exposed to FPN or FPT accumulated only 30% and 50% of the initially accumulated drug, whereas the FPN-M- or FPT-M-treated cells accumulated approximately 75% and 90% of the control, respectively. FPN-M and FPT-M also increased the uptake and decreased the efflux of VBL from MDR cells despite repeated washing. We also examined the effects of these modulators on sensitivity of MDR cells to cytotoxic agents. FPN-M and FPT-M sensitized MCF-7/AdrR cells to VBL and doxorubicin to a greater extent than their parent compounds. These studies point out the potential of "irreversible" P-gp modulators to produce prolonged chemosensitization.