Investigation of human brain hemodynamics by simultaneous near-infrared spectroscopy and functional magnetic resonance imaging.

The aim of this study was to compare functional cerebral hemodynamic signals obtained simultaneously by near infrared spectroscopy (NIRS) and by functional magnetic resonance imaging (fMRI). The contribution of superficial layers (skin and skull) to the NIRS signal was also assessed. Both methods were used to generate functional maps of the motor cortex area during a periodic sequence of stimulation by finger motion and rest. In all subjects we found a good collocation of the brain activity centers revealed by both methods. We also found a high temporal correlation between the BOLD signal (fMRI) and the deoxy-hemoglobin concentration (NIRS) in the subjects who exhibited low fluctuations in superficial head tissues.

Ethics counselors as a new priesthood.

The aim of this paper is to critically evaluate the thesis that ethics counselors constitute a new priesthood in the pejorative sense of this term. In defense of the thesis, an account is given of the diverse variety of fundamental ideas about ethics or morality. The underlying argument is simply that there is such a diversity of opinion about so many fundamental issues that most ethical appraisals, especially in committees, are probably very shallow and barely warranted. Following this negative work, an attempt is made to try to find some positive benefits from the work of ethics counselors. Some potential benefits are identified, but there is a need for empirical research in order to construct a more persuasive case for such work. In the penultimate section of the paper I addressed some of my own second thoughts about the discussion and some provocative suggestions that friends gave me about earlier drafts.

Near-infrared study of fluctuations in cerebral hemodynamics during rest and motor stimulation: temporal analysis and spatial mapping.

We have noninvasively studied the motor cortex hemodynamics in human subjects under rest and motor stimulation conditions using a multichannel near-infrared tissue spectrometer. Our instrument measures optical maps of the cerebral cortex at two wavelengths (758 and 830 nm), with an acquisition time of 160 ms per map. We obtained optical maps of oxy- and deoxy-hemoglobin concentration changes in terms of amplitudes of folding average, power spectrum and coherence at the stimulation repetition frequency, and the phase synchronization index. Under periodic motor stimulation conditions, we observed coherence and frequency or phase synchronization of the local hemodynamic changes with stimulation. Our main findings are the following: (1) The amplitude of the hemodynamic response to the motor stimulation is comparable to the amplitude of the fluctuations at rest. (2) The spatial patterns of the oxy- and deoxy-hemoglobin responses to the stimulation are different. (3) The hemodynamic response to stimulation shows a spatial localization and a level of phase synchronization with the motor stimulation that depends on the stimulation period.

Helicobacter pylori-positive functional dyspepsia in elderly patients: comparison of two treatments.

The association of Helicobacter pylori and functional dyspepsia is not well defined. The role of H. pylori on dyspeptic symptoms is still controversial. The aim of this study is to confirm the efficacy of H. pylori eradication by two different commonly used treatment regimens, as well as to examine the improvement of the dyspeptic symptoms by eradicating H. pylori. H. pylori functional dyspepsia is prevalent in people over 60 years old. In this age group we treated 126 patients with bismuth plus metronidazole and amoxicillin (group A, 67 patients) versus omeprazole plus amoxicillin (group B, 59 patients). Results were statistically analyzed utilizing the Wilcoxon signed-rank test, McNemer test and chi-square test; P < 0.05 was considered significant. Two months after the end of therapy we observed an eradication rate of 66.1% in group A vs 64.3% in group B. All treated patients showed improvement in symptomatology. Although there was no significant difference between patients in whom H. pylori was or was not eradicated within the respective groups, when examining all H. pylori-positive patients versus H. pylori-negative posttreatment patients, there was a significant reduction (P < 0.05) in all four symptoms of functional dyspepsia measured. In conclusion, we suggest that patients treated with H. pylori-eradicating therapeutic regimens have an improvement in functional dyspepsia symptoms. We shall prefer the dual therapy as compared to the triple therapy. We believe that eradicating treatment to eradicate H. pylori in the elderly patients with H. pylori-related functional dyspepsia will reduce health care costs by reducing the number of subsequent visits.

Squamous cell papillomatosis of esophagus following placement of a self-expanding metal stent.

The esophageal self-expanding metal stent has gained widespread acceptance for the management of tracheoesophageal fistulas and the palliative management of malignant esophageal strictures. The complications associated with its use can be classified as either immediate or delayed. The most frequent delayed complications include tumor ingrowth, stent migration, reflux of gastric contents, bleeding, and perforation. This case report illustrates an otherwise unrecognized delayed complication of a self-expanding metal stent. Near complete ingrowth of the stent by squamous mucosal hyperplasia occurred within six weeks of the metal stent's placement. This finding supports the hypothesis that mucosal injury and regeneration underlies the etiology of esophageal squamous cell papilloma formation.