Human-like brain hemispheric dominance in birdsong learning

Unlike nonhuman primates, songbirds learn to vocalize very much like human infants acquire spoken language. In humans, Broca's area in the frontal lobe and Wernicke's area in the temporal lobe are crucially involved in speech production and perception, respectively. Songbirds have analogous brain regions that show a similar neural dissociation between vocal production and auditory perception and memory. In both humans and songbirds, there is evidence for lateralization of neural responsiveness in these brain regions. Human infants already show left-sided dominance in their brain activation when exposed to speech. Moreover, a memory-specific left-sided dominance in Wernicke's area for speech perception has been demonstrated in 2.5-mo-old babies. It is possible that auditory-vocal learning is associated with hemispheric dominance and that this association arose in songbirds and humans through convergent evolution. Therefore, we investigated whether there is similar song memory-related lateralization in the songbird brain. We exposed male zebra finches to tutor or unfamiliar song. We found left-sided dominance of neuronal activation in a Broca-like brain region (HVC, a letter-based name) of juvenile and adult zebra finch males, independent of the song stimulus presented. In addition, juvenile males showed left-sided dominance for tutor song but not for unfamiliar song in a Wernicke-like brain region (the caudomedial nidopallium). Thus, left-sided dominance in the caudomedial nidopallium was specific for the song-learning phase and was memory-related. These findings demonstrate a remarkable neural parallel between birdsong and human spoken language, and they have important consequences for our understanding of the evolution of auditory-vocal learning and its neural mechanisms.     

Therapeutic hypothermia for acute myocardial infarction and cardiac arrest

This report focuses on cardioprotection and describes the advantages and disadvantages of various methods of inducing therapeutic hypothermia (TH) with regard to neuroprotection and cardioprotection for patients with cardiac arrest and ST-segment elevation myocardial infarction (STEMI). TH is recommended in cardiac arrest guidelines. For patients resuscitated after out-of-hospital cardiac arrest, improvements in survival and neurologic outcomes were observed with relatively slow induction of TH. More rapid induction of TH in patients with cardiac arrest might have a mild to modest incremental impact on neurologic outcomes. TH drastically reduces infarct size in animal models, but achievement of target temperature before reperfusion is essential. Rapid initiation of TH in patients with STEMI is challenging but attainable, and marked infarct size reductions are possible. To induce TH, a variety of devices have recently been developed that require additional study. Of particular interest is transcoronary induction of TH using a catheter or wire lumen, which enables hypothermic reperfusion in the absence of total-body hypothermia. At present, the main methods of inducing and maintaining TH are surface cooling, endovascular heat-exchange catheters, and intravenous infusion of cold fluids. Surface cooling or endovascular catheters may be sufficient for induction of TH in patients resuscitated after out-of-hospital cardiac arrest. For patients with STEMI, intravenous infusion of cold fluids achieves target temperature very rapidly but might worsen left ventricular function. More widespread use of TH would improve survival and quality of life for patients with out-of-hospital cardiac arrest; larger studies with more rapid induction of TH are needed in the STEMI population.     

The antimicrobial effect of Iseganan HCl oral solution in patients receiving stomatotoxic chemotherapy: analysis from a multicenter, double-blind, placebo-controlled, randomized, phase III clinical trial

J Oral Pathol Med (2012) 41 : 229–234 Background: Cytotoxic chemotherapy induces changes in the oral microflora that may cause oral and systemic infections in myelosuppressed cancer patients. These complications prompted us to assess the antimicrobial activity of a topical Iseganan HCl mouthwash vs. placebo on the aerobic and facultatively anaerobic oral flora in these patients. Methods: Two hundred and twenty‐five chemotherapy patients were recruited into a randomized, double‐blind, placebo‐controlled trial, conducted at multiple centers. The study compared the antimicrobial efficacy of Iseganan HCl vs. placebo (95% of the Iseganan and 97% of the control group received myeloablative chemotherapy). Iseganan HCl 9 mg/3 ml was administered as a swish and swallow solution, six times daily for 21–28 days. Microbial cultures were made before and after the daily Iseganan mouth rinse on the first and final days of chemotherapy. Results: The reduction in total microbial load after the first day of treatment was statistically significant (1.59 vs. 0.18 log10 CFU for the Iseganan HCl and placebo groups, respectively, P < 0.0001). Iseganan HCl rinse had a cumulative effect demonstrated by the significant difference between the two groups on the last day of the study (i.e. completion of Iseganan daily treatment) (P < 0.05). The reduction was mainly due to decreased densities of viridans streptococci, non‐hemolytic streptococci, and yeasts. The minimal inhibitory concentration (MIC) of Iseganan HCl remained the same throughout the course of treatment. Conclusions: Topical Iseganan HCl significantly reduces the total oral aerobic bacterial, streptococcal, and yeast load. Its potential as an oral antimicrobial agent in preventing these types of infections is clear.