Small proportions: what to report for confidence intervals?

The original article to which this Erratum refers was published in Pharmacoepidemiology and Drug Safety 2005; 14: 239–247.     

Aortopulmonary fistula detected by echocardiography 12 years after aortoplasty for correction of ascending aorta aneurysm.

We describe a case of aortopulmonary fistula in which the correct diagnosis was made by transthoracic echocardiography. The transesophageal approach, because of severe aortic dilatation, failed to provide the correct diagnosis, underlining the importance of complete transthoracic and transesophageal studies in the evaluation of aortic aneurysms.     

Modulation by glutathione of DNA strand breaks induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and its aldehyde metabolites in rat hepatocytes.

Activation of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) produced methylating species and two aldehydes: formaldehyde and 4-oxo-4-(3-pyridyl)-butanal (OPB). We investigated the modulation by glutathione of single-strand breaks (SSB) generated by N-methyl-N-nitrosourea (MNU) and the two aldehydes. Hepatocytes were simultaneously exposed to 0.2 mM MNU and to 0-2.00 mM formaldehyde or OPB for 4 h. Both aldehydes induced SSB in a dose-dependent manner. Formaldehyde and OPB exerted a synergistic effect on the formation of DNA SSB by MNU. It is postulated that both aldehydes interfere with DNA repair processes and thus increase the genotoxic effect of DNA methylating species. We investigated whether glutathione (GSH) could protect DNA from NNK-derived intermediates. Formaldehyde (2 mM) and OPB (2 mM) decreased intracellular GSH contents to 60 and 86% of control respectively. DL-Buthionine-[S,R]-sulfoximine (BSO) treatment reduced the GSH contents of hepatocytes to 19% of control but did not reduce the content of cytochrome P450 nor the metabolism of NNK. The frequency of DNA SSB induced by NNK, formaldehyde or OPB was significantly higher in GSH-depleted hepatocytes. GSH repletion with GSH monoethyl ester returned NNK-induced SSB to its initial frequency. OPB but not NNK nor formaldehyde induced double-strand breaks. We conclude that OPB and formaldehyde inhibit the repair of DNA damage induced by methylating species and that GSH reduces the level of DNA damage induced by NNK-derived reactive metabolites.     

Immunoassays for proteins alkylated by nicotine-derived N-nitrosamines

Polyclonal antibodies recognizing the pyridyloxobutyl (POB) moiety of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were produced in rabbits immunized either with POB-bovine albumin or POB-Sepharose. The POB intermediates necessary to modify the protein were generated by alkaline (pH 9.0) treatment of the synthetic precursor 4-(carbethoxynitrosamino)-1-(3-pyridyl)-1-butanone. In a competitive enzyme linked immunoabsorbent assay (ELISA), 70 pmole NNK inhibited 50% of the binding of the anti-POB antibodies to POB-protein absorbed on microtiterplates. This 50% inhibition varied from 70 pmole to 200 nmole using a series of NNK analogues, depending on the integrity of the POB moiety. Immunological techniques initiated in this study detect NNK-protein conjugates or measure the quantity of POB groups liberated upon alkaline or acid treatment of NNK modified protein.     

Expanding Our Strategies to Study the Process of Change

The conceptual and methodological framework proposed by Doss (this issue) makes valuable suggestions for strategic choices in future research. This commentary addresses conceptual and terminological distinctions adopted by Doss, as well as his criticism of add-on/ dismantling studies. We also suggest research topics and methodological developments that could be integrated in Doss's framework to further expand understanding of therapeutic change.     

Psychotherapy for depression: current and future directions in research, theory, practice and public policy

This article is based on a symposium held at the 1998 Annual Meeting of Society for Psychotherapy Research (Snow Bird, Utah). Recognized experts addressed current and future directions in psychotherapy for depression from the perspectives of process and outcome research, basic research, theoretical models, clinical practice and training, and public policy. The specific issues discussed at the symposium included the strengths and limitations of major forms of psychotherapy; the therapeutic factors common and unique to different approaches; the future viability of current theories of depression; the role of treatment manuals in clinical practice and training; the development of new interventions based on basic research; and the priorities that should guide federal funding.     

Capsaicin and its effects upon meal patterns, and glucagon and epinephrine suppression of food intake

The neurotoxin capsaicin has been shown to selectively interfere with unmyelinated sensory fibers, as well as leading to depletions of substance P and other peptides. Meal pattern analysis was performed both before and after treatment with capsaicin in twelve adult male Sprague-Dawley rats. Capsaicin treatment only briefly altered feeding patterns. No long term effect on body weight was noted. These same animals were then tested for the appetite suppressing effects of IP injections of glucagon (125 micrograms/kg) and epinephrine (30 micrograms/kg). Capsaicin treated rats decreased their intake of sweetened condensed milk during a 30 minute test in response to glucagon and epinephrine. Controls failed to suppress intake in response to glucagon, but drank less milk after epinephrine than did capsaicin treated rats. Efficacy of capsaicin treatment was obtained using similarly treated animals subject to histological evaluation within 2 days of capsaicin treatment. These results suggest that peripherally generated information relayed to the CNS via small-diameter sensory neurons is not a necessary component of the normal hunger/satiety sequence, nor body weight regulation.     

A comparison of three methods of scoring penile circumference changes

There are presently three widely used methods of scoring penile circumference data. The present experiment attempted to determine the ability of each method to explain the variance within a data set. A total of 19 subjects were presented with 20 photographic slides assigned to five categories: neutral, female adult, female adolescent, male adult, and male adolescent. Erectile responses to each slide were recorded and the data analyzed in terms of the raw scores, percentage of full erection, and a z-score transformation. Results indicated that the z scores captured the highest proportion of the variance (52.7%), followed by the percentage scores (32.5%), and the raw scores (30.1%). Findings are discussed in terms of their research and clinical implications.