Multicriteria decision analysis: a comprehensive decision approach for management of contaminated sediments.

Contaminated sediments and other sites present a difficult challenge for environmental decisionmakers. They are typically slow to recover or attenuate naturally, may involve multiple regulatory agencies and stakeholder groups, and engender multiple toxicological and ecotoxicological risks. While environmental decision-making strategies over the last several decades have evolved into increasingly more sophisticated, information-intensive, and complex approaches, there remains considerable dissatisfaction among business, industry, and the public with existing management strategies. Consequently, contaminated sediments and materials are the subject of intense technology development, such as beneficial reuse or in situ treatment. However, current decision analysis approaches, such as comparative risk assessment, benefit-cost analysis, and life cycle assessment, do not offer a comprehensive approach for incorporating the varied types of information and multiple stakeholder and public views that must typically be brought to bear when new technologies are under consideration. Alternatively, multicriteria decision analysis (MCDA) offers a scientifically sound decision framework for management of contaminated materials or sites where stakeholder participation is of crucial concern and criteria such as economics, environmental impacts, safety, and risk cannot be easily condensed into simple monetary expressions. This article brings together a multidisciplinary review of existing decision-making approaches at regulatory agencies in the United States and Europe and synthesizes state-of-the-art research in MCDA methods applicable to the assessment of contaminated sediment management technologies. Additionally, it tests an MCDA approach for coupling expert judgment and stakeholder values in a hypothetical contaminated sediments management case study wherein MCDA is used as a tool for testing stakeholder responses to and improving expert assessment of innovative contaminated sediments technologies.

The growth of chondrocytes into a fibronectin-coated biodegradable scaffold.

Porous scaffolds made from a biodegradable copolymer of trimethylene carbonate and glycolide were evaluated for tissue-engineered medical products. We examined the scaffold coated with cell adhesion protein and fibronectin and cultured under a dynamic mixing condition to enhance the growth of chondrocytes. Our hypothesis was that the combination of coating and dynamic mixing would be beneficial to the viability of the chondrocytic cells. Fibronectin was selected as the model protein because of its availability and routine assaying methods. Sterile samples of scaffolds of about 1 mm in thickness were coated with fibronectin at 37 degrees C for 1.5 h. Four groups of scaffolds were used: uncoated static or dynamic, and coated static or dynamic. Scaffold samples were placed in either a Petri dish or a spinner flask (static vs. dynamic groups) after inoculation with rat chondrocytes of an initial cell density of 1.29 x 10(5) cell/mL. After 7, 14, 21, and 28 days, each sample was fixed, embedded, and sectioned at 5 micro thickness. The sections were double-label immunostained using antibodies against cellular fibronectin synthesized by adherent cells as a measure of cell viability. A Hoechst 33258 nuclear stain was used to measure the number of cells attached to the scaffold at each time interval. The slides were examined using a fluorescence microscope to determine the cell ingrowth. At least 25 fields/treatment group (except the 7 day group) were measured. The data showed that cell in-growths into the porous scaffolds were higher at all time periods for the coated dynamic group than those for the other three groups.

Overtime reduction with the press of a button. An unexpected outcome of computerized documentation.

Overtime takes its toll on the staff and creates an opportunity to control cost. The purpose of this research was to investigate actual and perceived overtime amounts of nursing staff members before and after the implementation of a handheld computerized patient documentation system. Overtime amounts have decreased 29% since implementation of the system. Advantages and disadvantages of the system are also discussed.

Middle latency auditory evoked responses in normal term infants: a longitudinal study.

Middle latency auditory evoked responses (MLAERs) were measured in 21 normal term infants, three to five days after birth and then at 6 weeks, 7 months and 1 year of age. A polyphasic waveform was elicited during natural sleep in all infants at each recording session by monaural click stimulation at a rate of 9 per second. A 70 dBHL stimulus was found to be optimal as the MLAER became less well defined when the stimulus intensity approached the threshold hearing level. The first 60 to 70 msec of the waveform was found to be most stable, with decreasing detectability of peaks at longer latencies. There was no change in wave latency or reproducibility of MLAERs recorded during different sleep states. Waves Po and Na showed a significant decrease in latency with increasing stimulus intensity at term and/or 6 weeks of age. This was not evident for the remainder of the waveform. Waves Po, Na, Pa, Nb, Pb and Nc exhibited significant decreases in latency with age, attaining values indistinguishable from adults by 7 months of age.

Structure and function of the spermatheca in a snail host of schistosomiasis, Biomphalaria glabrata.

The histochemistry and ultrastructure (SEM and TEM) of the spermatheca of Biomphalaria glabrata was investigated to elucidate the function of this organ and to compare its structure and function to similar organs found in other species. The spermatheca has a debris-filled lumen surrounded by a thin wall of tissue. The cells adjacent to the lumen are of three columnar epithelial cell types. Two cell types have abundant microvilli and mammalian cell-like organelle distribution and morphology. The above cell types differ in the electron density of their cytoplasms, nuclear morphologies, and organelle content. The third cell type differs from the other two in its cytoplasmic makeup. However, the most distinctive difference is the presence of large numbers of cilia at the apical surface with no evidence of microvilli. These columnar cells rest on a basal lamina adjacent to a two to three cell thick muscle layer. The entire organ is surrounded by an adventitia of unusual morphology. Histochemical investigation demonstrated that DNAase, RNAase, and protease are present in the lumen, alkaline phosphatase is associated primarily with the microvilli, small amounts of acid phosphatase are concentrated in the midcell area of the columnar epithelium, and ATPase activity is localized in the muscle cells and just below the absorptive surface of the microvillous cells. The luminal contents and adventitial areas are Sudan Black B positive, all areas of the lumen and organ wall are PAS positive, the cell nuclei and amorphous masses in the lumen showed Feulgen staining, and large vesicles in the columnar cells were Oil Red O positive. Apparently, the spermatheca of B. glabrata is both a digestive and absorptive structure. Although this organ shares functional similarities with those found in opisthobranchs and terrestrial pulmonates, the epithelia of the spermatheca differ dramatically in these groups.

The effects of aspirin and dimethyl sulphoxide on the latency of lysosomes in a cell-free system.

Lysosomal preparations were exposed to various concentrations of dimethylsulphoxide (DMSO) and aspirin singularly and in combination. Acid phosphatase and beta-glucuronidase activities were measured and utilized as an indication of lysosomal membrane stability under experimental conditions in the presence and absence of these drugs. Extremely low concentrations of each drug were employed in an attempt to mimic the levels which might be feasible in vivo. There was a significant decrease of enzyme activity (increased structure-linked latency) in the presence of DMSO. Aspirin had no significant effect on the latency of the lysosomes. There was no indication of synergism between DMSO and aspirin. It was concluded that some of the therapeutic advantages attributed to DMSO in the treatment of arthritis and other musculoskeletal diseases may come from the stabilization of lysosomes in cells that contribute to the pathological condition. Aspirin did not seem to exert a therapeutic effect through this mechanism.

An improved method for the assay of platelet pyruvate dehydrogenase.

An improved method for the assay of human platelet pyruvate dehydrogenase is described. By generating the substrate [1-14C]pyruvate in situ from [1-14C]lactate plus L-lactate dehydrogenase, the rate of spontaneous decarboxylation is dramatically reduced, allowing far greater sensitivity in the assay of low activities of pyruvate dehydrogenase. In addition, no special precautions are required for the storage and use of [1-14C]lactate, in contrast to those for [1-14C]pyruvate. These factors allow a 5-10-fold increase in sensitivity compared with current methods. The pyruvate dehydrogenase activity of normal subjects as determined by the [1-14C]lactate system was 215 +/- 55 pmol . min-1 . mg-1 protein (n = 18). The advantages of this assay system are discussed.

A new and unusual type of transport vesicle.

The adventitial cells surrounding the spermatheca of the reproductive system of Sonorella santaritana (Mollusa: Gastropoda) appear to have an unusual system of vesicles. Electron micrographs of the membranes forming these vesicles show that they have multiple openings to the cell's exterior and that each opening has "pore complex". In addition, secondary vesicles appear to be generated by the primary vesicles. Evidence is presented suggesting that these vesicles represent a previously unreported membrane transport system.

Experimentally produced resistance of Schistosoma mansoni to hycanthone.

Genetically transferred resistance to the antischistosomal drug hycanthone has been observed in several strains of Schistosoma mansoni: 1) in the progeny of worms to whose hosts hycanthone had been administered 54 to 70 days after exposure to cercariae (Type I); 2) in the progeny of worms to whose hosts hycanthone had been administered when the worms were still in an immature stage (27 to 29 days after percutaneous cercarial exposure) (Type II); and 3) in the progeny of worms from hosts that had been infected with cercariae of one sex followed by infection with the opposite sex 2 to 58 weeks later (Type III). In types I and II, drug resistance was transferred maternally. Hycanthone-resistant schistosomes were cross-resistant to antischistosomal drugs structurally related to hycanthone, such as oxamniquine and two chloro-indazole analogs of hycanthone, but not to niridazole and to another nitroheterocyclic compound.

Inhibition by metrifonate and dichlorvos of cholinesterases in schistosomes.

1. No species differences between Schistosoma haematobium and Schistosoma mansoni were detected when the I50 of metrifonate for the acetylcholinesterases (AChE) and the cholinesterases (ChE) of these two trematodes were determined in isolated enzyme preparations or following exposure of the intact worms to this drug in vitro.2. S. haematobium appeared to be more affected by AChE inhibition because, after administration of metrifonate to hamsters, a hepatic shift of the parasites was observed with a dose of metrifonate (150 mg (0.6 mmol) per kg) which produced no shift of S. mansoni, although AChE inhibition was comparable in both species.3. Administration of a possible metabolite of metrifonate, dichlorvos, to hamsters resulted in a greater inhibition of AChE and ChE activities of S. haematobium than those of S. mansoni. Furthermore, when schistosomes were incubated with dichlorvos, inhibition of AChE activity of female S. haematobium was significantly greater (P<0.005) than that of both sexes of S. mansoni and of male S. haematobium.4. The discrepancy between the lack of a significant chemotherapeutic effect of metrifonate in hamsters infected with S. haematobium and the clinical results obtained with this organophosphorus compound in human schistosomiasis haematobium is discussed, and the need to conduct similar studies in primates is pointed out.

Hycanthone resistance: development in Schistosoma mansoni.

Following the administration of relatively high doses of the antischistosomal drug hycanthone to mice and hamsters infected with Schistosoma mansoni, a number of the worms survived. After a period of 6 to 12 months these parasites resumed production of viable eggs that gave rise to schistosomes that proved resistant to hycanthone and to two other related antischistosomal compounds. This drug resistance has remained stable for three subsequent generations of worms.