A discrete choice model of drug abuse treatment location

OBJECTIVE: To identify short-term drug abuse treatment location risk factors for ten large, self-insured firms starting January 1, 1989 and ending December 31, 1991. DATA SOURCES/STUDY SETTING: Study population selected from a large database of health insurance claims for all treatment events starting January 1, 1989 and ending December 31, 1991. STUDY DESIGN: A nested binomial logit method is used to estimate firm-specific patterns of treatment location. The differences in treatment location patterns among firms are then decomposed into firm effects (holding explanatory variables constant among firms) and variable effects (holding firm-specific parameters constant). PRINCIPAL FINDINGS: Probability of inpatient drug treatment is directly related to the type of drug diagnosis. The most important factors are diagnoses of drug dependence (versus drug abuse) and/or a cocaine dependence. Firm-specific factors also make a substantive difference. Controlling for patient risk factors, firm-specific probabilities of inpatient treatment vary by as much as 87 percent. Controlling for practices of firms and their insurance carriers, differing patient risk profiles cause probabilities of inpatient treatment to vary by as much as 69 percent among firms. Use of the outpatient setting increased over the three-year period. CONCLUSIONS: There are two plausible explanations for the findings. First, people beginning treatment later in the three-year period had less severe conditions than earlier cases and therefore had less need of inpatient treatment. Second, drug abuse treatment experienced the same trend toward the increased use of outpatient care that characterized treatment for other illnesses in the 1980s and early 1990s.     

Isolation and partial characterization of a polypeptide from Phoneutria nigriventer spider venom that relaxes rabbit corpus cavernosum in vitro

The venom of the Brazilian spider Phoneutria nigriventer was fractionated using a C18 microBondapack reverse-phase high-performance liquid chromatography column. The resulting fractions were assayed in the rabbit perfused corpus cavernosum tissue to identify those fractions responsible for the corpus cavernosum relaxation. Two fractions (A and B) with retention times of 18.1 and 36.7 min, respectively, induced relaxation of corpus cavernosum strips. Fraction A was selected for further biochemical characterization. Repurification of this fraction revealed the presence of a polypeptide (named PNV4) which migrates in sodium dodecyl sulphate-polyacrylamide gel electrophoresis as a single band consistent with a mol. wt close to 16,600. The amino acid composition of PNV4 showed the presence of 147 residues, a high content of Cys and a calculated mol. wt of 17,213 + Trp. The N-terminal amino acid sequence of PNV4 determined for its first 48 residues was AELTSCFPVGHECDGDASNCNCCGDDVYCGCGWGRWNCKCKVADQSYA.     

Abnormal thyroid and adrenocortical function test results in intensive care patients

A prospective, cohort study of 75 consecutive patients requiring management in the medical intensive care unit (MICU) of the Singapore General Hospital was carried out over a five-month period to determine thyroid and adrenocortical profiles and evaluate their use in predicting patient outcome. Up to 88% of patients had at least one abnormal thyroid function and 77% had abnormal adrenocortical function test results. There were significantly lower triiodothyronine, thyroxine and free thyroxine, but not thyrotropin levels, and higher cortisol levels in non-survivors compared to survivors (all P < 0.01). Of the endocrine parameters, triiodothyronine and cortisol concentrations were independent predictors of outcome. The overall predictive accuracy of combining these two variables on admission into the MICU was 74%. The APACHE II (acute physiology and chronic health evaluation II) score alone predicted outcome with 71% accuracy, and in combination with triiodothyronine and cortisol levels improved accuracy to 84%. The use of dopamine alone predicted outcome with 74% accuracy, and in combination with triiodothyronine and cortisol levels, improved accuracy to 84%. Measurements of total triiodothyronine and cortisol concentrations on admission to the MICU, and consideration of the use of dopamine improve on the APACHE II score in outcome prediction.     

32P-post-labelling analysis of DNA adducts formed in the upper gastrointestinal tissue of mice fed bracken extract or bracken spores

Bracken toxicity to both domestic and laboratory animals is well established and tumours are formed when rodents are treated with either bracken extracts or bracken spores. In this study we have administered bracken spores and extract to mice in order to investigate whether such exposure leads to the formation of DNA adducts. DNA, isolated from the upper gastrointestinal tract and liver, was digested to 3'-nucleotides. Adducts were extracted with butanol, 32P-post-labelled, separated by thin layer chromatography (TLC) and visualised and quantified using storage-phosphor technology. A cluster of adducts was clearly seen in the DNA of the upper gastrointestinal tract, but not liver, 5 and 24 h after treatment with bracken extract or bracken spores. These adducts were not observed in DNA extracted from vehicle-treated animals. Whereas, after 5 h adduct levels in extract and spore-treated animals were similar, after 24 h adduct levels in the extract-treated animals had diminished by > 75%, but levels in spore-treated animals remained similar to those found after 5 h. This suggests that the DNA-reactive compounds were being released slowly from the spores, even though the spores had been sonicated before administration. Adducts were also quantified after the addition of an internal standard (deoxyinosine 3'-monophosphate) by comparing the amount of label incorporated into the adducts with that found in a known amount of the internal standard. Adduct levels using this internal standard approach were similar to those found by direct measurement of radioactivity incorporated into the adduct, indicating that the labelling of adducts was quantitative. We have tried, unsuccessfully, to synthesise ptaquiloside, the principal carcinogenic component present within bracken. However, similar patterns of adducts were observed when two other compounds, (1-(4-chlorophenyl sulphonyl)-l-cyclopropane carbonitrile and 3-cyclopropylindeno [1,2-c] pyrazol-4-(O-methyl)oxime), which both contain a cyclopropyl ring, were administered to mice. The adducts detected in bracken-treated animals may, thus, have arisen from ptaquiloside but, whether these adducts arise directly from the compounds and bracken spores/extract themselves or via an indirect mechanism, remains to be determined. As bracken-induced DNA adducts are detectable in rodent tissues by a 32P-post-labelling procedure commonly employed to investigate DNA damage in human populations, it may prove possible to apply such approaches to determine human exposure.     

Effects of DDT on reproduction in multiple generations of beagle dogs

The effects of chronic oral exposure to 1, 5, and 10 mg of technical DDT/kg/day on: 1) age at puberty, length of gestation, fertility, success of pregnancy, litter size, and lactational ability of dams; 2) viability, survival to weaning, sex distribution and growth of pups; and 3) morbidity, mortality, organ/body weight ratios, gross and histologic abnormalities in all animals were studied through three generations of Beagle dogs. There were a total of 135 adult female and 63 adult male dogs in the project which produced 650 pups. There were no statistically significant differences among control and DDT-treated dogs in any of the reproductive variables, with the exception of age at puberty of the females. DDT-treated females had their first estrous cycles 2 to 3 months earlier (P less than .001) than the control dogs. Selected DDT-treated females, held for a second breeding period, had normal anestrous periods between their first and second estrous cycles. There was no effect of DDT on survival, growth, and sex distribution of pups, nor was there any influence on morbidity, mortality, gross or histologic findings in any of the dogs. All organ/body weight ratios were normal, with the possible exception of an increase in liver/body weight ratio in some DDT-treated animals.