The Temporal/Spatial Evolution of Optical Signals in Human Cortex

Intraoperative measures of functioning brain are an importantaspect to understanding normal and diseased cortical response.Previous studies, in animal models, have used optical reflectancemaps to illustrate the location and timing of functional activity.We used optical reflectance mapping in patients undergoing parietaltumor resection to reveal the temporal/spatial evolution ofperfusion and other related metabolic responses of sensorimotorcortex to peripheral somesthetic stimulation. The somatosensorycortex of seven anesthetized patients was mapped in responseto transcutaneous electrical median and ulnar nerve stimulationusing optical reflectance imaging. The time course and spatialextent of this response were measured end cor related with evokedpotential maps collected during the same conditions. Observable signals first appeared within 1–2 sac, peakedat 3 sec, and disappeared by 9 sec. These signals colocalizedwith the largest evoked potentials in both the sensory and motorregions end demonstrated topological specificity with medianand ulner nerve stimulation. Maps of this temporal/spatial resolutionillustrate the integrative and dynamic nature of the neurenal,vascular, and metabolic responses of human cortex. These dataalso provide insight to the mechanisms responsible for signalsobtained using other brain imaging techniques such as PET endfMRI.     

Multiparametric evaluation (SAMBA) of growth fraction (monoclonal Ki67) in breast carcinoma tissue sections

Breast tissue samples, including normal breast, nonmalignant disorders, and breast carcinomas (n = 257), were tested with monoclonal antibody Ki67 to define the growth fraction in each tissue subgroup. Immunocytochemical assays using anti-Ki67 and avidin-biotin-peroxidase complex and/or alkaline phosphatase anti-alkaline phosphatase were applied in frozen sections. The immunoreactions were analyzed with a computerized system of image analysis referred to as SAMBA (Systeme d'Analyse Microphotometrique à Balayage Automatique). This system permitted a multiparametric and automatized analysis of colored images. The results obtained were: (a) the SAMBA analysis of Ki67-positive staining was accurate, reliable, and reproducible; (b) the anti-Ki67 immunostaining was significantly (P less than 0.01) increased in malignancies and was related to the tumors' degree of differentiation, the vascular invasion, and the presence of axillary lymph node metastases; (c) anti-Ki67 immunostaining is increased (P less than 0.01) in tumors in which estrogen receptor and progesterone receptor antigenic sites are not detected. It is concluded that the SAMBA analysis of the anti-Ki67 immunocytochemical assay provides relevant information in selecting subgroups of patients with higher risk for relapse.     

Superficial- and deep-tissue temperature increases in anesthetized dogs during exposure to high specific absorption rates in a 1.5-T MR imager

Superficial- and deep-tissue heating was measured in five dogs during high-specific-absorption-rate radiofrequency (RF) irradiation to see whether significant temperature changes could be produced by a 1.5-T clinical magnetic resonance imager. The RF power output employed was 6.3 times that required for routine imaging. Temperature probes were placed in both deep and superficial tissues, and temperatures were recorded before, during, and after exposure. In each dog, there was a linear temperature increase of several degrees during RF exposure; the maximal average change was 4.6 degrees C in the urinary bladder. The temperature increase was slightly greater in deep tissues than in superficial tissues. The calculated specific absorption rate, based on the temperature change, averaged 7.9 W/kg for all five dogs. These findings argue for continued caution in the design and operation of imagers capable of high specific absorption rates, particularly when they are used for imaging infants or patients with altered thermoregulatory capability.     

Meningitis due to Micrococcus luteus

Summary We are presenting a new case of meningitis due to theMicrococcus luteus species. This germ was isolated twice in eight days from the CSF of a 57-year old woman. The patient had a ventriculoperitoneal shunt implanted for hydrocephalus following a meningeal haemorrhage. Antibiotic therapy was efficient but the patient died of a recurrent haemorrhage.

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Meningitis hervorgerufen durch Micrococcus luteus

Zusammenfassung Wir stellen einen gut dokumentierten Fall von Meningitis durchMicrococcus luteus vor. Dieser Keim wurde innerhalb von acht Tagen zweimal aus dem Liquor einer 57 Jahre alten Frau isoliert. Der Patientin war ein ventrikulo-peritonealer Shunt wegen eines nach Gehirnblutung aufgetretenen Hydrozephalus eingepflanzt worden. Die Meningitis wurde erfolgreich mit Antibiotika behandelt, jedoch starb die Patientin an einer erneut aufgetretenen Gehirnblutung.