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Biomedical subjects

Giuseppe Taborelli

Publications and source records attributed to Giuseppe Taborelli.

5 recordsLinked to original sources

Electronystagmography finding in children with peripheral and central vestibular disorders.

OBJECTIVE: Dizziness and imbalance are uncommon in children, but often alarming for their families: a detailed interview and otoneurological examination are important for reaching a specific diagnosis and treatment. Children with vestibular disorders are thought to be difficult to examine: vestibular tests (caloric test, roto-acceleratory test, electronystagmography, opto-kinetic nystagmus, cranio-corpography and posturography) are used less frequently for children than in adult patients. The aim of the study was to determine whether the results of electronystagmography testing improve an emergency physician's diagnosis of dizziness in children. METHODS: Patients were selected on the basis of the following inclusion criteria: aged between 2 and 12 years and affected with vertiginous symptoms. All patients underwent the following instrumental examinations: blood tests, audiological screening, electronystagmography of spontaneous nystagmus or provoked by vestibular and optical stimulation and electroencephalogram. RESULTS: The results underlines an high incidence of central vertigo (83%): 52% of the children presented a prevailing unidirectional nystagmus at labyrinth stimulation and 48% of the children an asymmetry in the response of nystagmus at optical kinetic stimulation with quality alteration of shocks. CONCLUSIONS: Electronystagmography can register and evaluate the qualitative and quantitative characteristics of the nystagmic response and allow to distinguish between central or peripheric vertigo: different degrees and various combinations of the abnormal responses shown in optokinetic central test were the most characteristic of electronystagmography in patients with vestibular central vertigo.

Cerebral Cortex↗

The human marginal zone B cell.

This study describes the features of the marginal zone (MZ) B cells of human tonsils and spleens and compares them with those of the follicular mantle (FM) B cells from the same tissues. The two B cell subpopulations displayed marked differences in phenotype, in response capacity to T cell-independent antigens and polyclonal B cell activators, and in presentation of antigens to T cells. FM B cells expressed surface CD5, and hence should be considered as B1 cells by current nomenclature. Fractionation of MZ B cells according to the presence or absence of surface IgD revealed the presence of two subsets. These subsets were characterized by different properties, including the presence of Ig V(H) gene mutations and the response capacity to TI-2 antigens, this latter property being associated with IgD-positive cells. Comparison of the data with those reported for mice revealed that human MZ B cells had strong analogies with both the murine MZ and B1 cells. In contrast, human B1 cells (that is, CD5-positive FM cells) were considerably different, an observation that should prompt further studies. Indeed, B cells with characteristics analogous to those of murine B1 cells were detected in small but definite proportions in the peripheral blood and tonsils. If the current distinction into B1 and B2 cells has to be maintained also for humans, it is likely that only these CD5-positive cells rather than the FM B cells should be called B1 cells.

Animals↗

Chemotaxis of human tonsil B lymphocytes to CC chemokine receptor (CCR) 1, CCR2 and CCR4 ligands is restricted to non-germinal center cells.

We have investigated the effects of nine CC chemokines, i.e. macrophage inflammatory protein (MIP)-1alpha/CCL3, MIP-1beta/CCL4, MIP-3alpha/CCL20, MIP-5/CCL15, monocyte chemotactic protein (MCP)-1/CCL2, MCP-2/CCL8, MCP-3/CCL7, eotaxin/CCL11 and macrophage-derived chemokine (MDC)/CCL22 on the locomotion of human tonsil B lymphocytes and their subsets. Upon isolation, B cells were poorly responsive, but, following short-term culture, they displayed statistically significant chemotactic responses (P < 0.001) to MIP-1alpha, MIP-5, MCP-1, MCP-2, MCP-3 and MDC. CC chemokine receptor (CCR) 1 to CCR6 were up-regulated after culture. MIP-1beta, MIP-3alpha and eotaxin did not stimulate B cell migration. Scattered information is available on B cell subset responses to chemokines. Therefore, we investigated the effects of MIP-1alpha, MIP-5, MCP-1, MCP-2, MCP-3 and MDC on the in vitro locomotion of non-germinal center (GC) (CD38(-)) and GC (CD38(+)) B cells. All chemokines enhanced significantly (P < 0.001) the migration of the former, but not of the latter, cells. CCR1, CCR2 and CCR4 were detected by flow cytometry on non-GC (i.e. naive and memory) B cells, whereas they were absent (CCR1 and CCR2) or poorly expressed (CCR4) on GC B cells.

B-Lymphocyte Subsets↗

The interleukin-12 and interleukin-12 receptor system in normal and transformed human B lymphocytes.

BACKGROUND AND OBJECTIVES: Interleukin-12 (IL-12) is a heterodimeric cytokine that induces interferon-g (IFN-g) production by natural killer and T-lymphocytes. IL-12 also activates human B-cells through the IL-12 receptor (IL-12R) complex. Here we review the expression and function of IL-12 and IL-12R in human B-cells and in their malignant counterparts. EVIDENCE AND INFORMATION SOURCES: The information provided derives from results both published and unpublished obtained in the laboratories of the Authors, and from a comprehensive review of all the pertinent articles published so far in Medline. STATE OF ART: The two components of the IL-12R, i.e. the b 1 and b 2 chains, were found to be constitutively expressed in human naive, germinal center and memory tonsil B-cells; however, only naive B-cells were activated following interaction with IL-2. Here we show that the IL-12Rb2 gene is not expressed in EBV-transformed normal B-lymphocytes and in Burkitt's lymphoma B-cell lines. IL-12 p35 and p40 transcripts were detected in all tonsil B-cell subsets, but only naive and memory B-cells produced IL-12. In this study, biosynthesis of IL-12 was investigated in tonsil B-cells, showing that the molecular weight of the mature heterodimeric IL-12 was similar to that of monocyte-derived IL-12, with minor differences possibly related to glycosylation. Finally, malignant B-cells from follicular and marginal zone lymphomas expressed IL-12 p35 and p40 transcripts, whereas only p35 mRNA was detected in mantle cell lymphoma. PERSPECTIVES: Taken together, the studies herein reviewed indicate that human B-cells, at variance with their murine counterparts, can produce IL-12 following CD40 ligation. IL-12 p35 and p40 transcripts are found in B-cells from different lymphoproliferative disorders, but the evidence that the cytokine is produced at the protein level is poor. IL-12R is expressed in the main human B-cell subsets, but it is functional only in naive B-cells. Finally, the failure of transformed B-cell lines to express IL-12Rb2 mRNA opens up new perspectives in the investigation of B-cell malignant transformation.

B-Lymphocytes↗