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Despite a close association between tobacco and cocaine use, few studies have systematically examined whether smoking predicts an adverse outcome for cocaine-dependent patients. We investigated whether severity of nicotine dependence was related to treatment outcome for cocaine-dependent individuals. Standardized assessments of nicotine dependence (Fagerström Test for Nicotine Dependence; FTND), cocaine use, and personality were obtained for 105 African American cocaine-dependent outpatients. Outcome measures included negative urine drug screens, days in treatment, dropout, and number of treatment sessions attended. The sample was stratified into cocaine-positive and cocaine-negative groups based on admission urine drug screens, and relationships between nicotine dependence and outcome measures were examined in each group. In the cocaine-negative group, higher FTND scores were negatively correlated with number of negative urine drug screens during treatment even after controlling for other predictors, whereas FTND scores were not correlated to outcome in the cocaine-positive group. It seems that severity of tobacco use predicts poor outcome for cocaine-dependent patients who are cocaine free at the time of admission into outpatient treatment. [ABSTRACT FROM AUTHOR]

A duplex polymerase chain reaction (PCR)-hybridization assay based on Mycobacterium avium subsp. paratuberculosis (MAP)-specific IS900 integration sites was used to evaluate two mycobacterial recovery methods from bovine feces: a direct-dilution-centrifugation method and a C18-carboxypropylbetaine (CB-18)-based method. All MAP PCR results were confirmed for absence of inhibitors using a novel PCR system based on the rpoB gene of plant chloroplasts as an internal control. The detection limits of both MAP recovery methods when coupled with PCR were determined to be between 100 and 1000 organisms. Using culture as a 'gold standard' PCR following the direct-dilution-centrifugation protocol was 92.6% sensitive and 83.7% specific, whereas PCR following the CB-18 method was 100% sensitive and 53.5% specific. Both methods were 100% specific when 60 'true' negatives from two uninfected herds were tested. Both the CB-18 and direct processing methods coupled with a target-specific amplification technique may provide greater sensitivity to diagnose subclinical animals as they were able to detect more positives, on samples derived from infected herds, than conventional culture methods: however, more extensive investigation and follow-up of suspect animals will be required to fully validate the MAP recovery and molecular detection protocols described. [ABSTRACT FROM AUTHOR]

Whether infection with Mycobacterium avium complex (MAC) among patients with acquired immune deficiency syndrome results from recent exposure to virulent strains or reactivation of latent infection acquired years earlier is unknown. To address this question, tissue samples from 47 simian immunodeficiency virus (SIV)-infected and 63 SIV-uninfected rhesus macaques were cultured. MAC was cultured from 14 SIV-un-infected macaques (22.2%) and 32 SIV-infected macaques (68.1%); median bacterial burdens were 33.3 and 998.7 cfu/g, respectively. Genetically distinct strains of MAC were identified for 13 SIV-uninfected macaques (20.6%) and 15 SIV-infected macaques (31.9%). A genetically identical MAC strain (K128A) was identified for 25 SIV-infected macaques (53.2%) and 1 SIV-uninfected macaque (1.6%). Multivariate analysis identified infection with SIV/Delta[SUBB670], diagnosis of an SIV-related tumor or opportunistic infection, and birth on site as risks for MAC infection. SIV-uninfected and SIV-infected macaques yielding unique strains of MAC were considered to have latent and reactivation infection, respectively, whereas animals infected with strain K128A were considered to have recent infection, demonstrating that both mechanisms occur among rhesus macaques. [ABSTRACT FROM AUTHOR]

The phenotypes in myotonic dystrophy types 1 and 2 (DM1 and DM2) are similar, suggesting a shared pathophysiologic mechanism. DM1 is caused by expansion of a CTG repeat in the DMPK gene. Pathogenic effects of this mutation are likely to be mediated, at least in part, by the expanded CUG repeat in mutant mRNA. The mutant transcripts are retained in the nucleus in multiple discrete foci. We investigated the possibility that DM2 is also caused by expansion of a CTG repeat or related sequence. Analysis of DNA by repeat expansion detection methods, and RNA by ribonuclease protection, did not show an expanded CTG or CUG repeat in DM2. However, hybridization of muscle sections with fluorescence-labeled CAG-repeat oligonucleotides showed nuclear foci in DM2 similar to those seen in DM1. Nuclear foci were present in all patients with symptomatic DM1 (n = 9) or DM2 (n = 9) but not in any disease controls or healthy subjects (n = 23). The foci were not seen with CUG- or GUC-repeat probes. Foci in DM2 were distinguished from DM1 by lower stability of the probe–target duplex, suggesting that a sequence related to the DM1 CUG expansion accumulates in the DM2 nucleus. Muscleblind proteins, which interact with expanded CUG repeats in vitro , localized to the nuclear foci in both DM1 and DM2. These results support the idea that nuclear accumulation of mutant RNA is pathogenic in DM1, suggest that a similar disease process occurs in DM2, and point to a role for muscleblind in the pathogenesis of both disorders. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined whether expression of Elongation Factor-1...or S1, a homologous protein found exclusively in postmitotic tissues, is reduced in senescent human skeletal muscle. Methods used; Results and discussion.

Much circumstantial evidence points to a neurotrophic influence in amphibian limb regeneration. Although fine-structural observations of nerves in regenerating limbs have indicated the possibility that neurosecretory vesicles accumulate distally in these axons, there is no clear-cut demonstration available that these organelles are neurotropic. Evidence is accumulating that the neural influence in newt limb regeneration is transneuronal. There is also evidence that trophic substances other than those found in the nerve itself may be involved in the supporting limb regeneration. The characterization of the neurotrophic substance is considered a central task for students of regeneration in the future. [ABSTRACT FROM PUBLISHER]