Suicide risk and symptom reduction in patients assigned to placebo in duloxetine and escitalopram clinical trials: analysis of the FDA summary basis of approval reports.

BACKGROUND: We assessed suicide and suicide attempt risk as well as symptom reduction among 3,282 depressed patients participating in duloxetine and escitalopram clinical trials assigned to either an antidepressant or placebo. METHODS: We reviewed the FDA Summary Basis of Approval reports for data regarding safety and efficacy for duloxetine and escitalopram. Furthermore, we compared suicide risk among antidepressant clinical trials in this study with our two previous analyses on seven antidepressant clinical trials. RESULTS: Suicide and suicide attempt risk varied considerably among the three analyses, showing up to ten fold differences. Interestingly, the variability exists across the three reports, rather than between treatments (antidepressants versus placebo). CONCLUSIONS: These findings suggest caution in generalizing suicide risk even from a relatively large number of participants and thus, firm conclusions can only be drawn if the number of participants is overwhelmingly large (approximately two million patients). We also noted similar magnitude of response to placebo and antidepressants among the three studies.     

Detection by PCR and isolation assays of the anaerobic intestinal spirochete Brachyspira aalborgi from the feces of captive nonhuman primates

The purpose of this study was to investigate the presence of the anaerobic intestinal spirochetes Brachyspira aalborgi and Brachyspira pilosicoli in the feces of captive nonhuman primates (n = 35) from 19 species housed at the Zoological Gardens, Perth, Western Australia. Both spirochete species are known to infect human beings. DNA was extracted from freshly collected feces with a commercially available QIAamp DNA stool minikit and subjected to PCR protocols amplifying portions of the 16S rRNA genes of the two spirochete species. The feces were also subjected to selective culture for the spirochetes. Subsequently, feces from 62 other captive animals or birds representing 39 species at the zoo were examined by PCR to determine whether they were reservoirs of infection. Six fecal samples from individuals from four primate species (two vervet monkeys, two Tonkean macaques, one Japanese macaque, and one hamadryas baboon) tested positive in the B. aalborgi PCR. B. aalborgi was not detected by PCR in any of the other animal or bird species tested, and B. pilosicoli was not detected in the primates or any of the other animals or birds. B. aalborgi was isolated from both PCR-positive vervet monkeys. This is the first time that B. aalborgi has been isolated from nonhuman primates and the first time that it has been isolated from the feces of any species.     

Novel Marine Compounds: Anticancer or Genotoxic?

In the past several decades, marine organisms have generouslygifted to the pharmaceutical industries numerous naturallybioactive compounds with antiviral, antibacterial,antimalarial, anti-inflammatory, antioxidant, and anticancerpotentials. But till date only few anticancer drugs (cytarabine,vidarabine) have been commercially developed from marinecompounds while several others are currently in differentclinical trials. Majority of these compounds were tested in thetumor xenograft models, however, lack of anticancer potentialdata in the chemical- and/or oncogene-induced pre-initiationanimal carcinogenesis models might have cost some of the marineanticancer compounds an early exit from the clinical trials. Thisreview critically discusses importance of preclinicalevaluation, failure of human clinical trials with certainpotential anticancer agents, the screening tests used, and choiceof biomarkers.     

Perceptions of first and third year medical students on self-study and reporting processes of problem-based learning

Background  

The objective of this study is to investigate the perceptions of first and third year medical students on self-study and reporting processes of Problem-based Learning (PBL) sessions and their usage of learning resources.     

Isolation of an entomopoxvirus and characterization of its DNA.

An entomopoxvirus from Choristoneura biennis was propagated in the eastern spruce budworm, Choristoneura fumiferana. The virus, released from its inclusion bodies by alkaline treatment, sedimented as a homogeneous band by rate zonal centrifugation through sucrose gradients. Electron microscopic examination showed that the particles possessed the mulberrylike structure that is typical of intact entomopox virions. The virus also produced a single band by isopycnic centrifugation in CsCl at a density of 1.31 g/ml. The genome, extracted with sodium lauryl sarcosinate and Pronase, sedimented as a single band through sucrose gradients, and its MW was calculated to be 132?142 × 10⁶ when compared to marker DNA from coliphage T2. Its sedimentation coefficient was 59S. The G + C content of the viral genome was investigated by thermal denaturation and buoyant density analysis in CsCl. The DNA melted at 61.6° and had a density of 1.6849 g/ml. These values are equivalent to a G + C content of 26.6% and 25.4%, respectively, which are considerably lower than those reported for the genomes of vertebrate poxviruses (G + C, 32.5–39%). The difference in G + C content between vertebrate and invertebrate poxviruses was confirmed by characterizing the genome of a second entomopoxvirus with respect to its t_m and buoyant density. The double-stranded nature of the DNA from invertebrate poxviruses was established from melting profiles and reaction with formaldehyde.