Renal clearance of digoxin in premature neonates

The renal clearances of digoxin and creatinine were determined in seven premature neonates (mean gestational age = 29.9 wk, range = 26 to 36 wk) at a postnatal age of 1 to 9 days (mean = 4.1 days). The corrected renal digoxin clearance (mean, 10.4 ml/min/1.73 m2; range, 2.5 to 36.7) was highly dependent on gestational age and body weight, r being 0.95 and 0.96, respectively (exponential curve). The linear slope of corrected renal digoxin clearance vs. creatinine clearance plot approached unity (r = 0.99), indicating that digoxin and creatinine were handled similarly by the kidney in these premature neonates (i.e. glomerular filtration with some degree of tubular secretion). Our finding of slower renal digoxin clearance helps to explain the higher serum levels and longer half-life of this drug in premature neonates.     

RET protooncogene mutational analysis in multiple endocrine neoplasia syndrome type 2B: case report and review of the literature

Multiple endocrine neoplasia, type 2B (MEN 2B), is a phenotypic variant of a group of autosomal-dominant neurocristopathies. MEN 2B is associated with medullary thyroid carcinoma and pheochromocytoma with oral, ocular, and alimentary submucosal ganglioneuromas and Marfanoid body features. Approximately 50% of cases are thought to be spontaneous mutations. The RET protooncogene (RET) is a 21-exon gene encoding a tyrosine kinase receptor. A codon 918 germ line mutation, which converts a highly conserved methionine to a threonine in the intracellular tyrosine kinase portion of this receptor of RET, has been identified in 95% of patients with MEN 2B. This mutation is easily detected by a direct deoxyribonucleic acid sequencing or restriction enzyme (Fok 1) analysis of amplified polymerase chain reaction products. The RET gene is normally expressed in the oral and gastrointestinal submucosal neural ganglia, and the codon 918 mutation is thought to cause neuromas by virtue of its transforming activity in these ganglia. Identifying clinical features of MEN 2B in an 11-year-old boy by an oral pathologist led to confirmation by mutational analysis. Before genetic testing was available, the patient, and at a later date his mother, underwent thyroidectomies based solely on biochemical testing. Results indicated the patient had the codon 918 mutation, whereas his phenotypically normal mother, father, and older brother had normal RET analyses. Studies in families have demonstrated that the mutant allele is derived from the father with possible acquisition during spermatogenesis. We believe the mother of our affected patient to be normal; the absence of phenotypic features of MEN 2B and a normal genotype suggest her calcitonin abnormalities and minimal evidence for C-cell hyperplasia were inconsequential. Molecular analysis for RET abnormalities will likely supplant biochemical methods of diagnosis in patients with MEN 2B.     

Time trends in ergonomic intervention research for improved musculoskeletal health and comfort in Latin America

Studies on ergonomic intervention research aiming at improved musculoskeletal health published in Latin America in the past 20 years were reviewed. The tendencies observed over time in these studies show that interventions carried out are trying to deal with the changes occurring in the production processes in this period. Thus, more participative approaches have been used, involving different parts interested in the process. The previous transversal projects, more focused on the physical aspects of the work, are now substituted by studies including organizational and longitudinal designs. Despite this, some negative or unchanged outcomes have been obtained. Therefore, good quality intervention studies are needed to provide more generalizable data and improve our understanding on planning, implementing and sustaining effective measures for controlling work-related musculoskeletal disorders.     

Evaluation of steady-state flow curves from model molecular weight distributions

Graessley's theory of entanglement was applied to several model distributions. The distribution functions chosen were such that the differential weight distributions were triangular with respect to a log molecular weight axis. The molecular weight level, breadth of the molecular weight distribution, skewness, and blending of simple distributions were studied in their effect on the steady-state flow curve. The governing factor for the shape of the reduced flow curve was shown to be M?_z+1·M?_z/M?_w². Other general features of the flow curve predicted by Graessley's theory were discussed.     

Field test and evaluation of residential sprinkler systems: Part III

A series of full-scale fire tests utilizing prototype “quick-response” sprinklers was conducted in a two-story residence in Los Angeles, CA, and a mobile home in Charlotte, NC. A prime objective of the program was to test the performance of alternative sprinkler designs to “control” the development of fire in single-family dwellings and mobile homes. Part of the mobile home test series focused on a study of the comparative activation times of sprinklers and smoke detectors installed in the same areas under a variety of test conditions. The results of that phase of the test program are given here. National Fire Protection Association REFERENCE: Cote, arthur E., “Field Test and Evaluation of Residential Sprinkler Systems”, Fire Technology, Vol. 20, No. 2, May 1984, p. 41. Mr. Cote is Assistant Vice President (Engineering & Technical Services) for the NFPA. He served as project manager for the test series insofar as the NFPA had overall management responsibilities for the program.     

Label-free protein recognition two-dimensional array using nanomechanical sensors

We demonstrate two-dimensional multiplexed real-time, label-free antibody-antigen binding assays by optically detecting nanoscale motions of two-dimensional arrays of microcantilever beams. Prostate specific antigen (PSA) was assayed using antibodies covalently bound to one surface of the cantilevers by two different surface chemistries, while the nonreaction surfaces were passivated by poly(ethylene glycol)-silane. PSA as low as 1 ng/mL was detected while 2 mg/microl of bovine serum albumin induced only negligible deflection on the cantilevers.     

A Method for Estimating the Potential Trading of Worked Water among Multiple Mines

In many parts of the world, mine production and expansion are increasingly limited by access to water. One solution is to consider a water market that would allow trading of mine site water (worked water) from wetter mines to drier mines. However, there is currently no policy support for such a market and it is likely that without government support via incentives, mines will continue to favour freshwater use because it is relatively inexpensive. Furthermore, mines have a high capacity to pay for the water they use, and freshwater creates few risks for production. The opportunity provided by water savings within a trading scheme could be viewed as a source of money to provide incentives for the transfer of worked water between mines. In this paper, we present a new method to trade water among mines based on a site water balance assessment utilising historical climate data, and apply this method to a demonstration region containing multiple coal mines. On average, 340 ML could be transferred per year to drier mines but there remains 11,440 ML per year of water demand unable to be met by trading. The direct monetary value of the worked water that could be transferred, derived from additional coal mining, would be significant. Irrigation may be an attractive option if available infrastructure can be used to trade the saved fresh water in existing markets, thereby providing indirect monetary value (i.e. external to coal production). Alternative uses of water savings may have considerable additional non-monetary value that directly affects the mining industry’s social license-to-operate and its security of long term water supply.     

Graphene oxide windows for in situ environmental cell photoelectron spectroscopy

The performance of new materials and devices often depends on processes taking place at the interface between an active solid element and the environment (such as air, water or other fluids). Understanding and controlling such interfacial processes require surface-specific spectroscopic information acquired under real-world operating conditions, which can be challenging because standard approaches such as X-ray photoelectron spectroscopy generally require high-vacuum conditions. The state-of-the-art approach to this problem relies on unique and expensive apparatus including electron analysers coupled with sophisticated differentially pumped lenses. Here, we develop a simple environmental cell with graphene oxide windows that are transparent to low-energy electrons (down to 400 eV), and demonstrate the feasibility of X-ray photoelectron spectroscopy measurements on model samples such as gold nanoparticles and aqueous salt solution placed on the back side of a window. These proof-of-principle results show the potential of using graphene oxide, graphene and other emerging ultrathin membrane windows for the fabrication of low-cost, single-use environmental cells compatible with commercial X-ray and Auger microprobes as well as scanning or transmission electron microscopes.