Variations in physicians' judgments about corticosteroid induced osteoporosis by physician specialty.

OBJECTIVE: Longterm corticosteroid use is associated with an increased risk of osteoporosis and fractures. Calcium and vitamin D supplementation and estrogen replacement therapy can decrease this risk, but the majority of patients receiving longterm corticosteroid treatment do not receive treatments to prevent bone loss. We assess whether this is due to variations in physicians' judgments about risks and efficacy of treatments to prevent corticosteroid-induced osteoporosis. METHODS: Questionnaires were mailed to 425 physicians, who were sampled so that half were generalists and half were specialists. Physicians were given hypothetical clinical scenarios involving patients taking corticosteroids and asked to judge the importance of osteoporosis as a risk of corticosteroid treatment, the importance of discussing this side effect with patients, and to indicate how often they would use calcium with vitamin D and estrogen for a hypothetical postmenopausal patient receiving longterm corticosteroid treatment. RESULTS: In total 198 physicians (50%) responded to this survey. Most physicians rated osteoporosis as one of the 3 most significant side effects of corticosteroid treatment for postmenopausal women, but there was significant variation in physician judgments about the importance of corticosteroid induced osteoporosis for premenopausal women (p=0.03) and men (p=0.001). There was also significant variation in physician judgments about the importance of discussing osteoporosis as a side effect with patients (p=0.001), and their use of both calcium and vitamin D (p=0.002) and estrogen replacement therapy (p=0.001) for a hypothetical postmenopausal patient. The physician characteristics most associated with these differences were physician specialty and experience with corticosteroid use. Primary care physicians and physicians who more commonly prescribe corticosteroids were more likely to report that they would use estrogen and calcium to prevent corticosteroid induced bone loss. Physician age, sex, and university affiliation had no association with physician assessments. CONCLUSION: Physicians' judgments varied significantly by physician specialty and experience with corticosteroid use. These data suggest that patients cared for by physicians in different specialties will get varying advice about osteoporosis risk and preventive treatments when receiving longterm corticosteroid treatment.

Oil degradation in soil.

The environmental effects of adding certain selected petroleum products to field soils at widely separated geographical locations under optimum conditions for biodegradation were studied. The locations selected for study of soil biodegradation of six oils (used crankcase oil from cars, used crankcase oil from trucks, an Arabian Heavy crude oil, a Coastal Mix crude oil, a home heating oil no. 2, and a residual fuel oil no. 6) were Marcus Hook, Pennsylvania, Tulsa, Oklahoma, and Corpus Christi, Texas. The investigative process, covering a period of 1 year at each location, was conducted in 14 fields plots (1.7 by 3.0 m) to which the oils were added in a single application at a rate of 11.9 m3/4 X 10(3) m2. One-half of the plots at each location were fertilized, and the incorporation of the oils and fertilizers was accomplished with rototillers to a depth of 10 to 15 cm. Concentrations of all oils decreased significantly at all locations. The average reduction ranged from 48.5 to 90.0% depending upon the type of oil and location. Rates of degradation did not exceed 2.4 m3/4 X 10(3) m2 per month. Compositional changes in the oil with time were investigated using silica gel fractionation, gas chromatography, and ultraviolet absorbance. With the possible exception of the two fuel oils, the compositional changes were generally in the same direction for all of the oils. The silica gel fractionation and gravimetric data on residual oils show that all classes of compounds were degraded, but the more polar type degrade more slowly. Analysis of runoff water, leachate, and soils indicated that at the concentration applied no oil less was observed from these plots via water movement. No significant movement of lead compounds added to the soils in the used crankcase oils was observed. Significant increases in hydrocarbon-utilizing microorganisms were demonstrated in all treated plots using either the pure hydrocarbon, n-hexadecane, or the applied oils as the growth substrate. These increases were usually sustained throughout the year. Significant increases in hydrocarbon-utilizing fungi were not demonstrated by the plating technique used. The concentrations of residual oils or their oxidation products were of sufficient magnitude in the treated plots, 9 months after application, to cause significant inhibition of plant growth. From the data obtained, it was not possible to determine the type of compounds causing this inhibition or their long-term environmental effects.

Microbial Hydrocarbon Co-oxidation. III. Isolation and Characterization of an alpha, alpha'-Dimethyl-cis, cis-Muconic Acid-producing Strain of Nocardia corallina.

A soil isolate identified as a strain of Nocardia corallina accumulated alpha, alpha'-dimethyl-cis, cis-muconic acid under co-oxidation conditions employing n-hexadecane for growth and p-xylene as the co-oxidizable substrate. N. corallina V-49 was postulated to have two pathways for the oxidation of p-xylene. One pathway proceeds throughp-benzyl alcohol, p-tolualdehyde, and p-toluic acid to 2, 3-dihydroxy-p-toluic acid, and the other pathway results in ortho ring cleavage of 3, 6-dimethylpyrocatechol and hence accumulation of alpha,alpha'-dimethyl-cis, cis-muconic acid.

Microbial hydrocarbon co-oxidation. II. Use of ion-exchange resins.

Anion-exchange resins, a weakly basic polystyrene-polyamine type and a macro-reticular type, IR-45 and IRA-93, respectively, were shown to significantly increase yields of acidic products in co-oxidation systems. p-Toluic, 2,3-dihydroxy-p-toluic, and alpha,alpha-cis,cis dimethylmuconic acids, resulting from the oxidation of p-xylene by three cultures of Nocardia, accumulated on the resin in shaken flasks or agar plates during the cultivation. Final product concentration increased with increasing resin concentration. Mineral balances were not affected if the resin was properly conditioned before use.

Microbial hydrocarbon co-oxidation. I. Oxidation of mono- and dicyclic hydrocarbons by soil isolates of the genus Nocardia.

Nocardia cultures, isolated from soil by use of n-paraffins as the sole carbon source, have been shown to bring about significant oxidation of several methyl-substituted mono- and dicyclic aromatic hydrocarbons. Oxygen uptake by washed cell suspensions was not a reliable indicator of oxidation. Under co-oxidation conditions in shaken flasks, o- and p-xylenes were oxidized to their respective mono-aromatic acids, o-toluic and p-toluic acids. In addition, a new fermentation product, 2, 3-dihydroxy-p-toluic acid, was found in the p-xylene oxidation system. Of 10 methyl-substituted naphthalenes tested (1-methyl, 2-methyl, 1, 3-dimethyl, 1, 4-dimethyl, 1, 5-dimethyl, 1, 8-dimethyl, 1, 6-dimethyl, 2, 3-dimethyl, 2, 6-dimethyl, 2, 7-dimethyl), only those containing a methyl group in the beta position were oxidized at this position to the mono acid.