Evolving dimensions in medical case reporting

Medical case reports (MCRs) have been undervalued in the literature to date. It seems that while case series emphasize what is probable, case reports describe what is possible and what can go wrong. MCRs transfer medical knowledge and act as educational tools. We outline evolving aspects of the MCR in current practice

A pneumococcal MerR-like regulator and S-nitrosoglutathione reductase are required for systemic virulence

Copyright © 2007 by the Infectious Diseases Society of America. All rights reserved.A transcriptional regulator, NmlR(sp), has been identified in Streptococcus pneumoniae that is required for defense against nitric oxide (NO) stress. The nmlR(sp) gene is cotranscribed with adhC, which encodes an alcohol dehydrogenase that is able to reduce S-nitrosoglutathione (GSNO) with NADH as reductant. nmlR(sp) and adhC mutants exhibited a reduced level of NADH-GSNO oxidoreductase activity and were more susceptible to killing by NO than were wild-type cells. Comparison of the virulence of wild-type and mutant strains by use of a mouse model system showed that NmlR(sp) and AdhC do not play a key role in the adherence of pneumococci to the nasopharynx in vivo. An intraperitoneal challenge experiment revealed that both NmlR(sp) and AdhC were required for survival in blood. These data identify novel components of a NO defense system in pneumococci that are required for systemic infection.Uwe H. Stroeher, Robert S. Kidd, Sian L. Stafford, Michael P. Jennings, James C. Paton and Alastair G. McEwa

Emulsion PCR: A High Efficient Way of PCR Amplification of Random DNA Libraries in Aptamer Selection

Aptamers are short RNA or DNA oligonucleotides which can bind with different targets. Typically, they are selected from a large number of random DNA sequence libraries. The main strategy to obtain aptamers is systematic evolution of ligands by exponential enrichment (SELEX). Low efficiency is one of the limitations for conventional PCR amplification of random DNA sequence library in aptamer selection because of relative low products and high by-products formation efficiency. Here, we developed emulsion PCR for aptamer selection. With this method, the by-products formation decreased tremendously to an undetectable level, while the products formation increased significantly. Our results indicated that by-products in conventional PCR amplification were from primer-product and product-product hybridization. In emulsion PCR, we can completely avoid the product-product hybridization and avoid the most of primer-product hybridization if the conditions were optimized. In addition, it also showed that the molecule ratio of template to compartment was crucial to by-product formation efficiency in emulsion PCR amplification. Furthermore, the concentration of the Taq DNA polymerase in the emulsion PCR mixture had a significant impact on product formation efficiency. So, the results of our study indicated that emulsion PCR could improve the efficiency of SELEX

Experiences in managing problematic crystal methamphetamine use and associated depression in gay men and HIV positive men: in-depth interviews with general practitioners in Sydney, Australia

© 2008 Saltman et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background This paper describes the experiences of Australian general practitioners (GPs) in managing problematic crystal methamphetamine (crystal meth) use among two groups of male patients: gay men and HIV positive men. Methods Semi-structured qualitative interviews with GPs with HIV medication prescribing rights were conducted in Sydney, Adelaide and a rural-coastal town in New South Wales between August and October 2006. Participants were recruited from practices with high caseloads of gay and HIV positive men. Results Sixteen GPs were recruited from seven practices to take part in interviews. Participants included 14 male GPs and two female GPs, and the number of years each had been working in HIV medicine ranged from two to 24. Eleven of the GPs who were based in Sydney raised the issue of problematic crystal meth use in these two patient populations. Five key themes were identified: an increasing problem; associations with depression; treatment challenges; health services and health care; workforce issues. Conclusion Despite study limitations, key implications can be identified. Health practitioners may benefit from broadening their understandings of how to anticipate and respond to problematic levels of crystal meth use in their patients. Early intervention can mitigate the impact of crystal meth use on co-morbid mental illness and other health issues. Management of the complex relationships between drug use, depression, sexuality and HIV can be addressed following a 'stepped care' approach. General practice guidelines for the management of crystal meth use problems should address specific issues associated with gay men and HIV positive men. GPs and other health practitioners must appreciate drug use as a social practice in order to build trust with gay men to encourage full disclosure of drug use. Education programs should train health practitioners in these issues, and increased resourcing provided to support the often difficult task of caring for people who use crystal meth. Greater resourcing of acute care and referral services can shift the burden away from primary care and community services. Further investigation should consider whether these findings are reproducible in other general practice settings, the relationship between depression, drug use and HIV medication, and challenges facing the HIV general practice workforce in Australia

Evidence for Shared Cognitive Processing of Pitch in Music and Language

Language and music epitomize the complex representational and computational capacities of the human mind. Strikingly similar in their structural and expressive features, a longstanding question is whether the perceptual and cognitive mechanisms underlying these abilities are shared or distinct – either from each other or from other mental processes. One prominent feature shared between language and music is signal encoding using pitch, conveying pragmatics and semantics in language and melody in music. We investigated how pitch processing is shared between language and music by measuring consistency in individual differences in pitch perception across language, music, and three control conditions intended to assess basic sensory and domain-general cognitive processes. Individuals’ pitch perception abilities in language and music were most strongly related, even after accounting for performance in all control conditions. These results provide behavioral evidence, based on patterns of individual differences, that is consistent with the hypothesis that cognitive mechanisms for pitch processing may be shared between language and music.National Science Foundation (U.S.). Graduate Research Fellowship ProgramEunice Kennedy Shriver National Institute of Child Health and Human Development (U.S.) (Grant 5K99HD057522

A nice surprise? Predictive processing and the active pursuit of novelty

Recent work in cognitive and computational neuroscience depicts human brains as devices that minimize prediction error signals: signals that encode the difference between actual and expected sensory stimulations. This raises a series of puzzles whose common theme concerns a potential misfit between this bedrock informationtheoretic vision and familiar facts about the attractions of the unexpected. We humans often seem to actively seek out surprising events, deliberately harvesting novel and exciting streams of sensory stimulation. Conversely, we often experience some wellexpected sensations as unpleasant and to-be-avoided. In this paper, I explore several core and variant forms of this puzzle, using them to display multiple interacting elements that together deliver a satisfying solution. That solution requires us to go beyond the discussion of simple information-theoretic imperatives (such as 'minimize long-term prediction error') and to recognize the essential role of species-specific prestructuring, epistemic foraging, and cultural practices in shaping the restless, curious, novelty-seeking human mind

Low adherence with antihypertensives in actual practice: the association with social participation – a multilevel analysis

BACKGROUND: Low adherence is a key factor in explaining impaired effectiveness and efficiency in the pharmacological treatment of hypertension. However, little is known about which factors determine low adherence in actual practice. The purpose of this study is to examine whether low social participation is associated with low adherence with antihypertensive medication, and if this association is modified by the municipality of residence. METHODS: 1288 users of antihypertensive medication were identified from The Health Survey in Scania 2000, Sweden. The outcome was low adherence with antihypertensives during the last two weeks. Multilevel logistic regression with participants at the first level and municipalities at the second level was used for analyses of the data. RESULTS: Low social participation was associated with low adherence with antihypertensives during the last two weeks (OR = 2.05, 95% CI: 1.05–3.99), independently of low educational level. However, after additional adjustment for poor self-rated health and poor psychological health, the association between low social participation and low adherence with antihypertensives during the last two weeks remained but was not conclusive (OR = 1.80, 95% CI: 0.90–3.61). Furthermore, the association between low social participation and low adherence with antihypertensives during the last two weeks varied among municipalities in Scania (i.e., cross-level interaction). CONCLUSION: Low social participation seems to be associated with low adherence with antihypertensives during the last two weeks, and this association may be modified by the municipality of residence. Future studies aimed at investigating health-related behaviours in general and low adherence with medication in particular might benefit if they consider area of residence