Reduced frontopolar brain activation characterizes concussed athletes with balance deficits.

OBJECTIVES: Athletes with sport-related concussions (SRC) often demonstrate deficits in postural stability. Lower cerebral blood flow in frontal cortices has been documented in athletes with symptoms after SRC, however, it is unclear if functional brain oxygenation during postural control tasks is reduced in symptomatic athletes after SRC in the same manner. We therefore compared brain oxygenation patterns in frontal cortices of symptomatic and asymptomatic athletes with SRC during postural control tasks with the hypothesis that symptomatic athletes are characterized by reduced functional brain oxygenation during postural control. METHODS: 62 concussed athletes (n = 31 symptomatic, n = 31 asymptomatic) were investigated during four postural control tasks with eyes closed versus eyes opened conditions and stable vs. unstable surface conditions. Brain oxygenation was assessed using functional NearInfraRed Spectroscopy (fNIRS) on frontopolar cortices of each hemisphere. Postural sway was measured by the analysis of ground reaction forces. RESULTS: Symptomatic athletes showed greater postural sway when compared to asymptomatic athletes during postural control, particularly during closed eyes and/or unstable surface conditions. Changes of oxygenated hemoglobin (∆HbO2) within the left hemispheric frontopolar cortex were significantly reduced in symptomatic athletes when compared to asymptomatic athletes during the eyes closed condition. A stepwise linear regression analysis revealed that self-reported post-concussion symptoms such as headaches and sadness predict decreased brain oxygenation during postural control with closed eyes. CONCLUSION: Symptomatic athletes with increased postural sway are characterized by decreased frontopolar brain oxygenation during postural control tasks, particularly during conditions with closed eyes. Because the frontopolar cortex showed to be involved in redistributing executive functions to novel task situations, we conclude that athletes with post-concussion symptoms suffer from a deficit in coordinating postural adjustments to balance control tasks with reduced sensory input.

Mathematical morphologic segmentation dedicated to quantitative immunohistochemistry.

OBJECTIVE: To develop automatic segmentation sequences for fully automated quantitative immunohistochemistry of cancer cell nuclei by image analysis. STUDY DESIGN: The study focused on the automated delineation of cancer cell lobules and nuclei, taking breast carcinoma as an example. A hierarchic segmentation was developed, employing mainly the chaining of mathematical morphology operators. The proposed sequence was tested on 22 images of various situations, collected from 18 different cases of breast carcinoma. A quality control procedure was applied, comparing the automated method with manual outlining of cancer cell foci and with manual pricking of cancer cell nuclei. RESULTS: Good concordance was found between automated and manual segmentation procedures (90% for cancer cell clumps, 97% for cancer cell nuclei on average), but the rate of false positive nuclei (small regions labeled as nuclei by the segmentation procedure) could be relatively high (11% on average, with a maximum of 35%) and can result in underestimation of the immunostaining ratio. CONCLUSION: This study examined a preliminary approach to automated immunoquantification, limited to automated segmentation without any color characterization. The automated hierarchic segmentation presented here leads to good discrimination of cancer cell nuclei at the chosen magnification.

Prospective trial evaluating early initiation of feeding in patients with newly placed one-step button gastrostomy devices.

The purpose of this study was to prospectively assess the feasibility and safety of early feeding in patients with newly placed one-step button (OSB) gastrostomy devices. Twenty-five patients who underwent percutaneous endoscopic button gastrostomy placement were prospectively enrolled. The patients underwent radiographic assessment (Gastrografin gastrograms) 3 hr after gastrostomy placement. Contrast extravasation was not documented in any patient. Aside from one patient who aspirated the contrast solution after the radiologic study, all others (96%) were successfully fed on the day the gastrostomy buttons were placed. In this prospective study of patients with newly placed OSB gastrostomy devices, early initiation of feeding was feasible and safe. In a fashion similar to their tube-style counterparts, button gastrostomy devices provide adequate apposition between the stomach and abdominal wall immediately after their initial placement.

[The effect of intracoronary infused captopril on luminal width in coronary stenosis]. / Einfluss von intrakoronar infundiertem Captopril auf die Lichtungsweite bei Koronarstenosen.

To elucidate the mechanism of anti-ischaemic and anti-anginal action of angiotensin-converting-enzyme inhibitors, a randomized double-blind study was undertaken in 30 consecutive patients (27 men, 3 women; mean age 58 [28-70] years) with stable angina and at least 50%, angiographically well demonstrated, stenosis of one of the main coronary artery branches. They received an intracoronary infusion of either 0.5 mg captopril (n = 16) or of a placebo (n = 14) to see whether in this form of application the drug could cause an acute dilatation of a coronary stenosis. The diameter before captopril administration was 1.40 +/- 0.63 mm, while 1, 5 and 10 min after infusion it was 1.49 +/- 0.58 mm, 1.30 +/- 0.54 mm and 1.41 +/- 0.59 mm (not significant). There was also no significant difference between captopril and the placebo. The absence of effect with captopril may be due to insufficient liberation of endothelium-derived relaxing factor in an arteriosclerotic coronary segment.