Molecular characterization of disseminated pilocytic astrocytomas.

AIM: Pilocytic astrocytomas represent the most common paediatric tumours of the central nervous system. Dissemination through the ventricular system occurs rarely in patients with pilocytic astrocytomas; however, it is more common in infants with diencephalic tumours, and is associated with a poor outcome. Despite histological similarities with classic pilocytic astrocytomas, it is still unclear whether disseminated pilocytic astrocytomas may have specific molecular features. METHODS: Seventeen disseminated pilocytic astrocytomas were investigated using the molecular inversion probe array and screened for the presence of gene fusions (KIAA1549-BRAF) and mutations (BRAF, RAS and FGFR1). RESULTS: Along with evidence of a constitutive MAPK activation in all cases, the molecular inversion probe array, fluorescence in situ hybridization analysis and mutational study revealed KIAA1549-BRAF fusions in 66% and BRAF(V600E) mutations in 5% of cases. No KRAS, HRAS, NRAS or FGFR1 mutations were found. CONCLUSIONS: disseminated pilocytic astrocytomas showed genetic features similar to classic pilocytic astrocytoma, including a similar incidence of KIAA1549-BRAF fusions, BRAF mutations and a stable genetic profile. Given common activation of the MAPK pathway, the use of specific inhibitors can be hypothesized for the treatment of disseminated pilocytic astrocytomas, along with standard chemo- and/or radiotherapy.

Successful hemicondylar femoral allograft for traumatic bone loss: a paediatric case study with ten years of follow-up.

The management of massive traumatic defects of the knee joint is challenging, especially in children. Massive osteoarticular allograft may be an option in this kind of traumatic bone loss. We report on the case of a male patient who (at the age of 15) suffered an open grade III condylar femoral joint fracture, with a massive bone defect and a Schatzker V tibial plateau fracture. Ten years after first-line treatment with massive osteoarticular allograft of the lateral femoral condyle, the patient's knee was capable of full extension and 90° flexion. The patient reached a point of being pain free for nine years before he subsequently developed some pain with lateral arthritis progression.

The UV erythema test as a model to investigate the anti-inflammatory potency of topical preparations--reevaluation and optimization of the method.

BACKGROUND: The ultraviolet (UV) erythema test is one of the most frequently used methods to investigate the anti-inflammatory potency of topical dermatological preparations in vivo. METHODS: The following questions were addressed in four separate studies with healthy persons (skin types 2 and 3): (1) the optimal localization was determined by comparing light scales on the back, buttocks and volar forearms; (2) the optimal UV-B dose was determined by comparing the 1-fold, 1.5-fold and 2-fold minimal erythema doses (MEDs); (3) hydrocortisone and prednicarbate were evaluated as positive controls, and a sample size calculation was performed, and (4) betamethasone valerate and pimecrolimus were tested as further positive controls in the optimized study model. RESULTS: The back proved to be the best localization for the UV erythema test. It showed a good correlation between the light scale and the test areas. The 1.5-fold MED was the best irradiation dose. In contrast to prednicarbate and betamethasone valerate, hydrocortisone was a rather weak positive control. However, when the sample size was > or = 40 subjects, significant results were also obtained with hydrocortisone. Pimecrolimus was not effective in the UV erythema test. CONCLUSIONS: The UV erythema test should be performed on the back with at least 40 subjects using the 1.5-fold MED. It may be useful to include a potent corticosteroid, such as prednicarbate or betamethasone valerate, in addition to hydrocortisone. The UV erythema test seems to be suitable only for substances with corticosteroid-like effects, since in this test model the calcineurin inhibitor pimecrolimus was not effective.

An infrared flash contemporaneous with the gamma-rays of GRB 041219a.

The explosion that results in a cosmic gamma-ray burst (GRB) is thought to produce emission from two physical processes: the central engine gives rise to the high-energy emission of the burst through internal shocking, and the subsequent interaction of the flow with the external environment produces long-wavelength afterglows. Although observations of afterglows continue to refine our understanding of GRB progenitors and relativistic shocks, gamma-ray observations alone have not yielded a clear picture of the origin of the prompt emission nor details of the central engine. Only one concurrent visible-light transient has been found and it was associated with emission from an external shock. Here we report the discovery of infrared emission contemporaneous with a GRB, beginning 7.2 minutes after the onset of GRB 041219a (ref. 8). We acquired 21 images during the active phase of the burst, yielding early multi-colour observations. Our analysis of the initial infrared pulse suggests an origin consistent with internal shocks.

Memory of action events: the role of objects in memory of self- and other-performed tasks.

Encoding action phrases by enactment produces better recall than hearing or reading the action phrase. This study examined whether enactment enhances memory relative to observing another perform the same action. Theories of the enactment effect suggest that the complexity of the action, here manipulated by varying the number of objects involved in an action, may determine whether enactment enhances memory relative to observation. The results revealed a consistent subject-performed task advantage across all object conditions; the size of the effect did not vary with increasing task complexity. Additionally, items that included the use of an object were recalled better than those without objects. The results are consistent with the views of Engelkamp and Zimmer (1997) and Backman, Nilsson, & Kormi-Nouri (1993), who argued that the SPT effect is due to motor and/or sensory encoding.

Attention and perceptual priming in the perceptual identification task.

Prior research indicates that manipulations of attention during encoding sometimes affect perceptual implicit memory. Two hypotheses were investigated. One proposes that manipulations of attention affect perceptual priming only to the extent that they disrupt stimulus identification. The other attributes reduced priming to the disruptive effects of distractor selection. The role of attention was investigated with a variant of the Stroop task in which participants either read words, identified their color, or did both. Identifying the color reduced priming even when the word was also overtly identified. This result held regardless of whether color and word were presented as a single object (Experiments 1 and 2) or as separate objects (Experiment 4). When participants read and identified a color, the overt order of the responses did not matter; both conditions reduced priming relative to reading alone (Experiment 3). The results provide evidence against the stimulus-identification account but are consistent with the distractor-selection hypothesis.

Ventilatory muscle training in kyphoscoliosis.

Cardiorespiratory failure is the usual cause of death in severe kyphoscoliosis. The pathophysiology of this mechanism will be reviewed. Ventilatory muscle training (VMT), a relatively new respiratory technique, has been shown to improve the strength and endurance of the ventilatory muscles. It is known that stronger, endurance trained ventilatory muscles will guard against ventilatory muscle fatigue which may lead to respiratory failure. The actual technique is described with documentation of two representative cases. Case 1 showed a 63% increase in maximum inspiratory mouth pressure (PiMax) and an increased ability to walk and climb stairs with comfort. Case 2 used VMT as an adjunct to her weaning protocol from a portable ventilator. She progressed from full-time to nocturnal ventilator assistance in 1 month.

The epidemiology of genital colonization with Staphylococcus aureus.

The prevalence of genital colonization with Staphylococcus aureus, including strains that have been associated with toxic shock syndrome, was studied in 600 women. Nine percent of these women were colonized with S. aureus, 5% of whom had positive vaginal cultures, and 1% were colonized with toxin-producing strains. Black women were colonized with S. aureus, including toxin-producing strains, as frequently or more frequently than white women. The highest colonization rates occurred in postpartum women. Trends toward increasing colonization occurred in relation to decreasing age and socioeconomic status. There were no statistically significant relationships between genital colonization with S. aureus and the use of tampons, oral contraceptives, or a variety of other personal habits and health problems. Genital cultures taken in consecutive menstrual cycles indicated that 35% of women with S. aureus were persistent carriers, and the rest either intermittent or transient carriers. Toxin-producing S. aureus was also identified in family members of women carrying the same organism. This report defines the prevalence of genital colonization in a large population of women, characterizes the women with S. aureus, and describes epidemiologic features of genital carriage.

Preliminary data on a new method for lithium therapy.

Lithium therapy was assessed using electrosleep on two dogs. Cotton swabs soaked in an aqueous isotonic lithium chloride solution were placed over the eyes and mastoids of the dogs, and connected to the electrosleep apparatus. In two minutes, sleep was induced in both dogs, at point 5 (mA) on the intensity scale (which runs 1 to 9 mA). After two hours, the apparatus was turned off. One of the dogs was put under continuous observation, and the other one was sacrified. Parts of its cortex, subcortex, and cerebellum were processed and fragments were assayed spectrophotometrically for Lithium. Lithium was found in all the material examined. These results suggest a possible technique for Lithium therapy using electrosleep, the ion being carried directly to CNS, avoiding systemic toxicity caused by oral administration.