Neuropsychological evaluation and parental assessment of behavioral and motor difficulties in children with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant multisystem disorder, with large inter and intrafamilial clinical variability and uncertain prognosis. In children with NF1 cognitive disorders, learning difficulties and behavioral problems are common. The present study aims to establish the neuropsychological and behavioral profiles of 78 patients with NF1, aged between 5 and 18 years, and to examine the relationship between these profiles and the transmission of NF1 (sporadic vs. familial), clinical manifestations, and environmental factors. We used several questionnaires completed by parents and neuropsychological tests. The results confirmed specific neuropsychological disabilities in children with NF1, especially involving visuospatial and fine motor skills, learning difficulties and behavioral problems. Cognitive difficulties were significantly more frequent in patients with familial than in those with sporadic NF1. All parental questionnaires were correlated with each other, but parental reports were not associated with FSIQ, SES, school status, and clinical manifestations of the disease. Neuropsychological tests were poorly related to parental reports of cognitive and behavioral difficulties.

Serum tryptase concentrations in beekeepers with and without Hymenoptera venom allergy

BACKGROUND

Increased tryptase concentrations are a risk marker for the severity of reactions to Hymenoptera stings or venom immunotherapy

OBJECTIVE

To investigate serum tryptase concentrations in beekeepers with and without Hymenoptera venom allergy (HVA).

METHODS

Serum tryptase concentrations were measured in adult patients with HVA (n = 91, 37 of whom were beekeepers), beekeepers without HVA (n = 152), and control individuals from the general adult population (n = 246).

RESULTS

Multivariate analyses revealed that serum tryptase levels were positively associated with beekeeping activities (P < .001) and HVA (P < .001). Tryptase levels were also positively associated with age (P < .001) and male'sex (P = .02), and negatively associated with alcoho consumption (P = .002).

CONCLUSIONS

Beekeeping and HVA are independently associated with increased concentrations of serum tryptase.

Functional topology of the mossy fibre-granule cell--Purkinje cell system revealed by imaging of intrinsic fluorescence in mouse cerebellum

We report an activity-induced green fluorescence signal observed when mouse cerebellar slices were illuminated with blue light and parallel fibre-Purkinje cell synapses were activated. The optical signal consisted of an initial increase in fluorescence that peaked within 1-2 s after the onset of stimulation, followed by a long lasting (40 s) transient decrease in fluorescence. Single or tetanic electrical stimuli applied to the molecular layer elicited 'beam-shaped' fluorescence changes along the trajectory of parallel fibres. These signals reported activation of Purkinje cells as they were depressed by antagonists of ionotropic and metabotropic glutamate receptors at Purkinje cells and correlated with Purkinje cell spiking activity. Optical responses induced by direct pharmacological activation of glutamate receptors were reduced by a calcium-free extracellular medium, consistent with the hypothesis that they reflect metabolic activity due to an increased intracellular calcium load associated with neuronal activation. We used these intrinsic fluorescence signals to address the question of whether granule cells excite Purkinje cells only locally via the ascending branches of their axons, or more widespread along the parallel fibre trajectory. White matter stimulation of the mossy fibres also elicited a beam-like fluorescence change along the trajectory of parallel fibres. Simultaneous imaging and extracellular recording demonstrated the association between the beam-like fluorescence signal and Purkinje cell spiking. This non-invasive imaging technique supports the notion that parallel fibre activity, evoked either locally or through the mossy fibre-granule cell pathway, can activate postsynaptic Purkinje cells along more than 3 mm of the parallel fibre trajectory.

Characterization of a metabotropic glutamate receptor type 5-green fluorescent protein chimera (mGluR5-GFP): pharmacology, surface expression, and differential effects of Homer-1a and Homer-1c

Metabotropic glutamate receptor 5 (mGluR5) can modulate synaptic transmission by increasing intracellular Ca2+ and it plays a role in several forms of synaptic plasticity. We have constructed a fusion of human mGluR5 and green fluorescent protein (mGluR5-GFP). Expression of mGluR5-GFP in clonal cell lines yielded a functional fluorescent receptor with pharmacological profiles similar to wild-type mGluR5. mGluR5-GFP coimmunoprecipitated with Homer-1c, indicating that addition of GFP to the C-terminal did not prevent Homer binding. Coexpression of wild-type mGluR5 or mGluR5-GFP with Homer 1c, but not Homer-1a, resulted in reduced receptor surface localization and the formation of intracellular clusters. Neither Homer-1a nor Homer-1c had any effect on mGluR1 or mGluR1-GFP distribution. mGluR5-GFP expressed alone or in combination with Homer-1a formed dimers in HEK cells. Coexpression with Homer-1c, however, prevented mGluR5-GFP dimerization. Neither Homer altered the agonist profiles of mGluR5 or mGluR5-GFP. These data indicate that the functional expression of mGluR5 is regulated by Homer-1c and demonstrate that mGluR5-GFP provides a useful tool to study the molecular pharmacology and cell biology of mGluRs in real-time.

Rapid internalization and surface expression of a functional, fluorescently tagged G-protein-coupled glutamate receptor

l-Glutamate is the principal excitatory neurotransmitter in the vertebrate central nervous system, where it mediates many of its actions via G-protein-coupled metabotropic glutamate (mGlu) receptors. Since little is known about the dynamics of mGlu receptors at the plasma membrane, we have constructed a fusion protein comprising the mGlu receptor subtype 1alpha (mGlu1alpha) and green fluorescent protein (GFP). Using imaging of Ca2+ release from intracellular stores as a functional assay, the agonist pharmacology of this fluorescently tagged receptor was found to be similar to that of the wild-type receptor when expressed in HEK-293 cells. Receptor movement and function were measured simultaneously by combined imaging of Ca2+, using fura-red, and GFP fluorescence in single cells. Exposure to agonist induced a rapid loss of up to 30% of membrane-associated fluorescence, with a corresponding decrease in the functional response. Following removal of the agonist there was recovery of both the membrane fluorescence and the functional response. These data suggest that the surface expression of G-protein-coupled glutamate receptors might be rapidly regulated in response to agonist activation.

Combined method for simultaneous morphology, immunophenotype and karyotype (MAC) in leukemias

In the present study, a combined method (CM) for attaining simultaneous identification of leukemic cell morphology, karyotype and immunophenotype has been evaluated in 21 patients with acute leukemia and 1 with CML in blast crisis were studied for morphology, citochemistry, immunophenotype and karyotype. Karyotype was performed in a bone marrow sample by using conventional techniques. In each case, direct method (DM) and/or three cultures were tried. The CM consisted in separating a small part of the material resulting from any of the cultures or DM, preparing slides through cytospin and immunophenotyping through APAAP method using the same monoclonal antibodies (MoAb) as for diagnosis. In 14 cases, the metaphases proved positive to the MoAb: in 4, the cells with abnormality had their origin defined; in other 4 the karyotype was normal preventing any identification; 6 cases had minimal abnormalities not visible through CM; and in two cases abnormal karyotypes were detected only in the cultures with GM-CSF. This study showed that CM is feasible in cases where evident numerical or structural chromosomal abnormalties are present.

Simplified method for the analysis of cellular karyotype and phenotype in leukemias

The objective of this study was to develop a simplified method for the simultaneous analysis of cellular karyotype and phenotype which would permit the identification of cell origin. We studied 6 patients with AML, 3 with CML (one of which was in blastic transformation) and one ALL. We used a method in which the suspension of bone marrow cells was incubated in TC 199 medium with colchicine and with hypotonic solution formed from glycerol, NaCl, KCl, CaCl2, MgCl2 and sucrose. The slides were prepared from this cell suspension by cytospin and stained for peroxidase, PAS, esterases and iron. The karyotype was studied by direct method and culture. It was possible to relate the cytogenetic marker with cytochemistry characteristics in the same cell in 3 cases, showing the feasibility of cytochemistry techniques in cytogenetical preparations. The best preparations were found through peroxidase. The presence of iron granules allowed identification of erythroblastic lineage in the combined staining. Mitosis with a marker chromosome of leukemic clone in an AML cell with negative peroxidase probably showed a proliferation of more primitive precursor not sufficiently differentiated to show markers.

Paracoccidioidomycosis in a patient with acquired immunodeficiency syndrome

The authors report a case of paracoccidioidomycosis and other opportunistic diseases in a patient with acquired immunodeficiency syndrome.