Interactions of orthopaedic metals with an immortalized rat osteoblast cell line

The toxicity of nickel, chromium (III) and (VI), vanadium and aluminium was compared in an immortalized neonatal rat osteoblast cell line using the MTT assay and a novel index of cytotoxicity, alkaline phosphatase (ALP) activity. Where toxicity was observed, ALP was a consistently more sensitive detection method than the MTT assay. The toxicity of the metals increased in the order aluminium < chromium (III) < vanadium < nickel < chromium (VI). alpha-Tocopherol partially prevented nickel-induced toxicity (as assessed by ALP activity), whereas ascorbic acid had no protective effect. Chromium (VI) was more toxic than (III), with significant toxicity observed at 0.5 microM. It is thought that Cr (III) cannot readily penetrate the cell membrane and this may account for the lower toxicity. Aluminium had a stimulatory effect on cell growth at low concentrations (0.5 microM). The combination of immortalized rat osteoblasts and the ALP activity test provides a powerful tool for in vitro testing of orthopaedic materials.     

A method for simultaneous recording and assessment of gut contractions and relaxations in vivo

The normal gut exhibits both contractions and relaxation from a resting tonus. Pathological and pharmacological information may be gleaned from separate measurement of these activities. Methods for recording and analyzing gut contractions have been presented before. We present an extension to the methods, utilising simple foil strain gauges tested here in male Sprague-Dawley rats. Coupled with a computer-based data acquisition and analysis system, we could assess the relaxation and contraction waves recorded simultaneously and from different gut regions in vivo. In contrast with the antrum, where spontaneous motor activity consisted of low frequency relaxations and random contractions, spontaneous duodenal motility was patterned into periodic groups of intense activity interposed by periods of low amplitude, low frequency contractions and relaxations. This grouped activity was propagatory, reminiscent of migrating myoelectrical complexes. When challenged with the ulcerogen cysteamine-HCl (56 mg/100 g s.c.), only duodenal motor activity was affected. Moreover, this treatment had differential effects in the duodenum. Patterned motility was no longer distinguishable, and contraction frequency and amplitude were increased while relaxation amplitude was decreased. This method affords a particularly sensitive and more precise assessment of both contractile and relaxant motor activity in vivo, before and after drug treatment.     

Response to methadone maintenance and counseling in antisocial patients with and without major depression

This study compared the treatment response of four groups of psychiatrically diverse opiate-dependent, methadone maintenance patients receiving drug counseling. The four groups were patients with no other nonsubstance abuse axis I psychiatric diagnoses (OP only; N = 65), patients with lifetime major depression (DEP; N = 60), patients with both antisocial personality disorder and lifetime major depression (APD + DEP; N = 35), and patients with only APD (APD only; N = 24). Patients were assessed at intake, during treatment, and 7 months after treatment admission. No statistically significant differences were found among the groups in treatment retention/attendance. Few significant group differences were revealed during-treatment urine screens, except that barbiturate use was more common for the APD only group. The APD only group also had significantly more positive urine screens for benzodiazepines than the other three groups at 7-month follow-up. All groups reported considerable improvement in problem level at 7 months compared with admission status. The APD only group reported fewer gains in legal and employment problems than the other groups but reported greater improvement in the drug area. Thus, there was some limited support for a prior finding, based on individual psychotherapy, that the treatment response of APD only patients was inferior to that of APD + DEP patients or non-APD patients.     

Minimizing dioxin emissions from integrated MSW thermal treatment

The combustion of wastes has very significant benefits in reducing the volume of waste materials and producing energy. However, combustion processes produce emissions, which must be below the Best Practical Means (BPM) specified legislative limits. Several wastes, such as tires and meat meal, have been successfully combusted in cement kilns, up to 20% w/w, while retaining emission standards well below legislative limits. In the case of municipal solid waste (MSW) the introduction of large amounts of MSW into cement kilns is not practical because the additional kiln volume required is too great, the large amounts of ash generated will affect the cement clinker quality, and it would be difficult to sustain the required very high clinkering temperature of 1500 degrees C with large quantities of low calorific value MSW. A completely novel process, termed the Co-Co process, has been developed, integrating MSW combustion in a synergistic fashion with the cement production. This process is based on combining the cement "front-end" calcination reaction and incorporating it with a high temperature, at 1200 degrees C, combustion process, providing a giant acid gas scrubber. A pilot plant was designed, constructed, and operated to demonstrate the benefits of the Co-Co process. The pilot plant achieved emissions minimization: dioxins were typically 0.5-1% of the European BPM limits, HCl, SOx, NOx, and particulates were 15, 10, 20, and 25% of BPM limits, respectively. Heavy metals were typically below 25% of BPM limit values.     

Mechanical considerations for the implant tooth-supported fixed partial denture

The implant tooth-supported fixed partial denture presents a biomechanical design problem, because the implant is rigidly fixed within the alveolus, and the tooth is surrounded by a periodontal ligament that allows movement. Nonrigid fixed partial denture designs are advocated by some dentists as a method of compensating for this differential movement. Rigid fixed partial denture designs, however, are advocated by many clinicians. Studies have failed to show the advantage of one design over the other. This study developed an in vitro method for testing such prosthesis designs and measured movement of a natural tooth abutment during simulated function. The movement of the natural tooth abutment was not found to change substantially with the fixed partial denture designs tested.     

Effects of random versus nonrandom assignment in a comparison of inpatient and day hospital rehabilitation for male alcoholics.

Alcoholic patients randomly assigned to day hospital or inpatient rehabilitation were compared with patients who self-selected these treatment settings to examine differences in substance use and psychosocial outcomes under experimental and nonexperimental designs. Patients who self-selected treatment did not have better outcomes than those who were randomly assigned, and there were no significant differences between day hospital patients and inpatients on any of the 11 outcome measures. Significant interactions between treatment setting and assignment were found with only 2 outcome measures. Therefore, the comparisons between day hospital and inpatient treatment yielded similar outcomes under both "scientific" conditions and the conditions that more closely approximate the experiences of most patients. Implications for the use of nonrandomized participants in alcoholism treatment research and limitations of the study were also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

INTERACTION OF SUPERCRITICAL METHANOL AND WATER WITH ORGANIC MATERIAL IN GREEN RIVER OIL SHALE

A series of experiments to study the interaction of supercritical methanol and water with Green River oil shale was performed. The volume percentage of methanol (CH₃0H) in water was varied. The temperature was held constant at 400°C. The products were fractionated and characterized with infrared spectroscopy and elemental analyses. A ¹³CH₃0H experiment was carried out and 13C nuclear magnetic resonance (NMR) analysis was used to prove the incorporation of methanol into the products. The methyl esters resulting from the incorporation were isolated and characterized by high resolution mass spectrometry. The experiments on a model compound and gas chromatographic/mass spectral (GC/MS) analysis of the product showed that methanol can react with carboxylic acids found in Green River oil shale to form methyl esters. However, this incorporation of methanol into the product oil from supercritical fluid extraction was found to be not sufficient to account for the increased oil yields, The role of methanol in these experiments on Green River oil shale is discussed.     

Analysis of acids in high-boiling petroleum distillates

The major acidic compound types in ten high-boiling crude-oil distillates were identified as carboxylic acids, phenols, carbazoles, and amides. Acids from crude oils having different geological characteristics were separated using a standardized separation scheme involving the use of gel permeation, adsorption, and thin-layer chromatography, and preliminary comparisons have been made between the compositional results. In one method, compound types were isolated and the percentage of each was determined gravimetrically; in two other methods infrared spectrometry was used to estimate the relative amounts of individual types. The structures of the acidic compounds were examined in detail using mass, fluorescence, and nuclear-magnetic-resonance spectrometry. Trace amounts of pericondensed polyaromatic hydrocarbons were found in all the acid samples.     

Tracing N, K, Mg and Ca released from decomposing biomass to new tree growth. Part I: A model system simulating harvest residue decomposition on conventionally harvested clearfell sites

It is necessary to assess the effects of removing nutrient-rich harvest residues (brash) from clearfell sites because there is a growing market for this brash as bioenergy. The aim of this study was to use stable isotope techniques in a model system to trace nutrients released by decomposing brash. Labelled biomass was obtained by growing Sitka spruce (Picea sitchensis (Bong.) Carr.) seedlings with a generous or poor nutrient supply containing elevated ¹⁵N, ⁴¹K, ²⁶Mg, and ⁴⁴Ca. This biomass was used in two subsequent studies. In this study (Part I of II), the above-ground biomass was harvested and placed on soil in a pot containing a newly planted seedling. Soils from two forests, Ae and Teindland, of contrasting nutritional status were used. A full destructive harvest was undertaken after one growing season. Enriched ¹⁵N, ⁴¹K, ²⁶Mg, and ⁴⁴Ca were recovered in the new seedlings. The percentage contribution from labelled biomass to new tree growth was small, but discernible. The N contribution from labelled biomass to new trees was greater in Ae soil, but the base cation contribution was greater in Teindland soil. Results are discussed with reference to the initial nutrient concentrations of each soil. The elevated ¹⁵N, ⁴¹K, ²⁶Mg and ⁴⁴Ca in new seedlings indicate that nutrients in brash can make a direct contribution to new tree growth. The success of this model system will provide guidance for the application of similar techniques in field experiments.