Biomedical subjects

A Salerno

Publications and source records attributed to A Salerno.

At least 19 recordsLinked to original sources

PubMed2000

Vgamma9/Vdelta2 T lymphocytes reduce the viability of intracellular Mycobacterium tuberculosis.

An effective immune response against the intracellular pathogen Mycobacterium tuberculosis is strictly dependent on T cell activation. Although this protective response mainly depends on local release of pro-inflammatory cytokines by Th1 CD4(+) T cells, contribution of Vgamma9 / Vdelta2 T lymphocytes to immune protection against this pathogen is suggested by the antimycobacterial reactivity of this subset and its ability to produce large amounts of Th1 cytokines. Here we show that Vgamma9 / Vdelta2 T lymphocytes kill macrophages harboring live M. tuberculosis. The cytotoxic activity of Vgamma9 / Vdelta2 T lymphocytes was not MHC class I or class II restricted but was blocked by anti-TCR monoclonal antibodies, thus indicating that it involved specific interaction between the TCR and the target cell. The cytotoxicity of Vgamma9 / Vdelta2 T lymphocytes was not mediated by TNF-alpha or Fas-Fas ligand, but was shown to occur through a granule-dependent mechanism that resulted in reduction of the viability of intracellular bacilli. Perforin was shown to play an important role in killing of both infected macrophages and intracellular mycobacteria. These data strongly suggest that Vgamma9 / Vdelta2 T lymphocytes contribute to the host defense against M. tuberculosis infection.

Cells, Cultured↗

PubMed2000

Townes-Brocks syndrome and renal dysplasia: a novel mutation in the SALL1 gene.

A 14-year-old African-American boy had chronic renal failure and Townes-Brocks syndrome (TBS). There were no affected family members. Features were imperforate anus, rectoperineal fistula, triphalangeal thumb, bifid thumb, rocker bottom feet, bilateral ear tags, satyr ear, sensorineural hearing loss, hypospadias, bilateral renal hypoplasia, and progressive chronic renal failure. Renal and urological anomalies in TBS include renal hypoplasia, renal dysplasia, unilateral renal agenesis, horseshoe kidney, posterior urethral valves, uretero-vesical reflux, and meatal stenosis. TBS is caused by a dominantly inherited defect in the gene encoding the SALL1 putative transcription factor, a protein possibly required for urological, renal, limb, ear, brain, and liver development. This patient had a novel mutation in this gene. The extent of renal involvement in patients with TBS should be evaluated for optimum treatment and prediction of prognosis.

Abnormalities, Multiple↗

PubMed2000

Motor cortical dysfunction disclosed by single and double magnetic stimulation in patients with fibromyalgia.

OBJECTIVE: To investigate the motor cortex by single and double magnetic stimulation, in patients with fibromyalgia. METHODS: Thirteen patients with fibromyalgia and 13 age-matched healthy subjects were examined. We evaluated, in both limbs, motor evoked potential (MEP) latency and amplitude and the MCA/MPA ratio, i.e. MEP cortical amplitude (MCA) /maximal peripheral amplitude of the M response (MPA), the central conduction time (TCC) and the length of the silent period (SP). With double magnetic stimulation, different time intervals between shocks were used: with delays between shocks of 4, 25, 55 and 85 ms, the intensities of the conditioning shock were 80% the relaxed threshold. With delays between shocks of 55, 85, 100, 155, 200, 255 and 355 ms, the intensities of the conditioning shocks were set at 150% the relaxed threshold. In all cases, the intensity of the test shock was 150% the relaxed threshold. The results were also compared with those obtained in 5 women affected by rheumatoid arthritis (RA). RESULTS: As compared to control, the cortical relaxed threshold was enhanced on both sides and limbs (P<0.05). The cortical silent period recorded with single magnetic stimulation was reduced in the upper limbs (P = 2.7x10(-11)) and lower limbs (both sides P = 3.6x10(-5)). The other parameters investigated were normal. With double magnetic stimulation, facilitatory phenomena were absent in fibromyalgic patients and the inhibitory responses recorded with a delay of 155 ms were reduced (P = 0.0052). No significant differences were noted between FM and RA patients. CONCLUSION: This study demonstrated motor cortical dysfunction in patients with fibromyalgia involving excitatory and inhibitory mechanisms. This indicates motor cortical involvement and supports the hypothesis of aberrant central pain mechanisms. The absence of differences between FM and RA suggest that the lesions were not specific and could be related to chronic pain disorders within the central nervous system.

Adult↗

PubMed2000

Change of Th0 to Th1 cell-cytokine profile following tuberculosis chemotherapy.

T cells mediate protection against tuberculosis, but little is known about their role during chemotherapy of patients with active disease. Here we examined the cytokine profile of CD4 T cells before and after four months of chemotherapy in six initial skin test anergic cases. Purified protein derivative (PPD) and 16-kDa antigen-reactive CD4 T-cell clones prior to therapy resided mostly in disease-associated body fluids and were of the Th0 (interferon (IFN)-gamma + interleukin (IL)-4) secreting profile. In contrast, the majority of postchemotherapy CD4 T-cell clones originated from blood and were of the IFN-gamma secreting Th1 type. However, the recognition of several peptides derived from the 16-kDa antigen was not significantly different between the Th1 and Th0 clones. We conclude that chemotherapy shifts CD4 T cells from the affected body fluids to the blood circulation, accompanied by a change from Th0 to Th1 cytokine profile.

CD4-Positive T-Lymphocytes↗

PubMed2000

Ligand-specific alphabeta and gammadelta T cell responses in childhood tuberculosis.

The alphabeta and gammadelta T cell responses were analyzed in the peripheral blood of children affected by active tuberculosis (TB) and in healthy children who tested positive (PPD+) or negative (PPD-) for purified protein derivative. PPD+ healthy and diseased children responded equally well to PPD in vitro. In contrast, only 18% of PPD+ TB patients responded to peptide p38G derived from the 38-kDa protein of Mycobacterium tuberculosis. Analysis of the whole gammadelta T cell population and of its Vgamma9/Vdelta2 subset showed similar frequencies in PPD+ children with TB and in healthy PPD+ and PPD- children. Vgamma9/Vdelta2 cells from children with TB responded to 5 different phosphoantigens similarly to those from healthy PPD+ children, but healthy PPD- children responded very poorly. Chemotherapy had contrasting effects on the tested lymphocyte population, represented by increase of alphabeta and decline of Vgamma9/Vdelta2 T cell responses. T cell responses in childhood TB may be similar to those in adult TB.

Adolescent↗

PubMed2000

Neuronal loss in Onuf's nucleus in three patients with progressive supranuclear palsy.

Disorders of micturition have been reported only sporadically in patients with progressive supranuclear palsy (PSP). We report the results of a clinicopathological study of 3 patients with a definite diagnosis of PSP at various stages of their illness with sphincter abnormalities. Electromyography of the sphincter muscles was performed in all 3 patients and was abnormal in 2. Morphological and morphometric evaluation of Onuf's nucleus in the sacral spinal cord, which is involved in sphincter control, showed severe cell loss, presence of neurofibrillary tangles, neuropil threads, and glial inclusions. We conclude that bladder dysfunction and abnormal sphincter electromyographic results are due to pathological changes in Onuf's nucleus, and we propose that sphincter abnormalities should be included in the list of possible symptoms of PSP.

Aged↗

PubMed1999

Broad clonal heterogeneity of antigen-specific CD4+ T-cells localizing at the site of disease during tuberculosis.

The repertoire of CD4+ T-lymphocytes was investigated in six patients affected by tuberculosis, who had a negative PPD skin test at diagnosis. Polyclonal CD4+ T-cell lines from the peripheral blood failed to proliferate to PPD and to the 16- or 38-kDa proteins of Mycobacterium tuberculosis, while CD4+ T-cell lines from the site of disease responded to PPD, and to the 16- and 38-kDa proteins, and derived epitopes in vitro. The repertoire of CD4+ T-cells accumulating at the site of disease was found to be widely heterogeneous as demonstrated by the finding that at least seven different peptides from the 16- and 38-kDa proteins were recognized by every patient. These results indicate that CD4+ T-cells localized at the site of disease in tuberculosis recognize a vast array of M. tuberculosis epitopes.

Amino Acid Sequence↗

PubMed1999

Different role of human HLA-DR and -DQ molecules in xenogeneic transplantation using transgenic mice.

BACKGROUND: The role of T lymphocytes in graft rejection in xenotransplantation is still unclear. The ability of the human HLA class II molecules DR and DQ to function as xenoantigens was investigated in a murine model of skin grafting, using HLA-DR1 and -DQ6-transgenic mice. METHODS: Skin from HLA-DR1- or -DQ6-transgenic mice was transplanted in control littermates. Spleen cells from donors or recipients were tested in mixed lymphocyte reaction and cytotoxic assay. RESULTS: Skin from HLA-DR1-transgenic mice was rejected and spleen cells from rejecting mice were able to proliferate to donor cells, although no rejection was observed when the skin of HLA-DQ6-transgenic mice was engrafted in control littermates. No cytotoxicity was observed in any models. CONCLUSIONS: Taken all together these results clearly suggest a hierarchy in the xenogeneic potency of human HLA class II molecules, with the HLA-DR1 molecule functioning as a potent xenoantigen when compared with the HLA-DQ6 molecule.

Animals↗

PubMed1999

High-performance liquid chromatographic determination of n-methylformamide, a biological index for occupational exposure to dimethylformamide.

This report describes an analytical method for the biological monitoring of workers exposed to N,N-dimethylformamide (DMF), a solvent widely used in the chemical industry. The human main metabolites of DMF are N-hydroxymethyl-N-methylformamide (HMMF) and the minor metabolites N-methylformamide (NMF) and N-acetyl-S-(N-methylcarbamoyl)cysteine. The metabolite selected by the American Conference of Governmental Hygienists for occupational biomonitoring purposes, is NMF measured by gas chromatographic analysis, as during it HMMF may be converted to the minor metabolite NMF. HMMF and NFM can be measured independently using HPLC analysis. The procedure proposed here involves the thermal transformation of the primary metabolite HMMF into the minor metabolite NMF, which is then determined by HPLC. This method makes it possible to determine, using HPLC, both metabolites of DMF by measuring only one peak, thus offering two major advantages: (i) it increases the sensitivity of the test and (ii) it deploys only one reference standard.

Calibration↗

PubMed1999

Primary central nervous system lymphoma presenting with a parkinsonian syndrome of pure akinesia.

The incidence of primary central nervous system lymphoma (PCNSL), once a rare tumour, has risen significantly in both immunocompetent and immunosuppressed patients. Although infiltration of the basal ganglia is not uncommon in PCNSL, extrapyramidal movement disorders are generally not recognised as a mode of clinical presentation of this type of cerebral tumour. We present the unusual case of a 75-year-old man who developed a parkinsonian syndrome of "pure akinesia" due to autopsy-confirmed PCNSL primarily involving the globus pallidus bilaterally. Parkinsonism due to bilateral pallidal lesions is known but rare, and such cases help in the understanding of basal ganglia function with regard to akinesia and freezing.

Aged↗

PubMed1999

Induction and tolerization of anti-male CD8+ cytotoxic T lymphocytes by in vivo immunization with an H-Y-derived peptide.

We have analyzed the immune response induced by a 9mer synthetic peptide derived from the male histocompatibility antigen H-Y and containing Db-binding motifs in C57BL/6 mice. In this study we report that a single, subcutaneous injection of the peptide emulsified in IFA gave rise to the development of male-specific CD8+ T cells which displayed H-Y-specific proliferative response in vitro and showed a Tc1-type pattern of cytokine production (i.e. they secreted IFN-gamma and IL-2, but not IL-4 and IL-10). Development of a strong cytotoxic activity required in vitro stimulation with specific peptide and IL-2: under these culture conditions, we were able to generate potent CD8+ CTLs that lysed both male cells and peptide-pulsed female cells. Continuous administration of soluble peptide, delivered over a 7-day period by a mini-osmotic pump implanted subcutaneously, inhibited proliferative and cytotoxic responses and IFN-gamma production in lymph node cells from C57BL/6 mice subsequently primed with peptide in adjuvant. This decreased responses were associated with a strong increase in the secretion of IL-4 by antigen-specific CD8+ T lymphocytes. Subcutaneous administration of the H-Y-peptide in adjuvant significantly accelerates rejection of male skin graft, while continuous administration of peptide in soluble form did not modify the time course of rejection.

Animals↗

PubMed1999

[Evoked motor potentials obtained with double magnetic cortical stimulation: techniques and interpretation].

UNLABELLED: The technique of motor evoked potentials (MEP) obtained with single and double magnetic stimulation of the motor cortex in man has considerably improved over the past decade. We present the techniques and parameters involved in double magnetic stimulation for clinical purposes. METHOD: The conditioning-test design is used to study modifications in the amplitudes of the muscular responses to the "test" shock, recorded on the first dorsal interosseus muscle. Enhanced amplitudes of conditioned responses indicate facilitation, reduced response inhibition. RESULTS: The effects vary according to the shock intensity, the delay between shocks and the position of the conditioning coil. The latter may be located at the same place as the test shock (to test interneural circuitry related to pyramidal tract), on the hand area opposite the test shock (to test interhemispheric influences), or over the cerebellar area contralateral to the test side (to test the effect of cerebellar stimulations over the motor cortex). When the coils were located on the same cortical hand area there was facilitation when the intensities were both set at the threshold with an interstimulus interval (ISI) between 1 and 2.5-3 ms. At conditioning shock intensities below the threshold and the test shock 150% above, inhibition occurred at ISI 1-5 ms followed by facilitation at ISI 15-35 ms. When the intensities of both shocks were 150% above threshold, there were two clear cut individual responses at ISI above 10 ms; facilitation was recorded at ISI 15-35 ms, and inhibition between 55 and 255 ms. When the conditioning coil was located on the opposite hand area from the test shock (conditioning shock intensity supramaximal, test shock intensity above the threshold), ISI 1-5 ms facilitation occurred followed by inhibition up to ISI 30 ms. When the conditioning shock (intensity supramaximal) was located on the cerebellar area contralateral to the test side (intensity above the threshold), inhibition occurred at ISI 5 ms. CONCLUSIONS: Double magnetic stimulations delivered over the same cortical area reflect facilitatory and inhibitory influences over the pyramidal tract controlled by interneurons, i.e., these tests investigate the intrinsic circuitry of the motor strip. Double magnetic stimulations delivered on each motor area study interhemispheric influences mediated by the corpus callosum, which are facilitatory and inhibitory. Double magnetic stimulations delivered on the cerebellar area demonstrates inhibitory influences over the contralateral cerebral motor cortex.

Adult↗

PubMed1999

Impaired contact hypersensitivity to trinitrochlorobenzene in interleukin-4-deficient mice.

We have examined the role of endogenously produced interleukin-4 (IL-4) in the contact hypersensitivity (CH) reaction to the haptene trinitrochlorobenzene (TNCB). The CH reaction was abolished in IL-4 genetically deficient mice (IL-4 KO), when compared to wild-type (wt) mice. The CH reaction was restored by treatment with IL-4 and further analysis revealed that IL-4 exerted its action both at the induction and effector stages of the CH reaction. Despite failure to develop a CH reaction, IL-4 KO mice developed a T helper type 1 (Th1) response to TNCB, in terms of lymphokine production in vitro. Furthermore, the number of Vgamma3+ cells accumulating in the lymph nodes of TNCB-immune IL-4 KO mice was normal. The recruitment of mononuclear cells and vascular leakage at the challenge site were consistently reduced in IL-4 KO mice and were restored by injection of IL-4. This suggests that IL-4 acts as a proinflammatory mediator in CH, perhaps favouring the accumulation of mononuclear cells at the site of inflammation. Among Th2-type cytokines, IL-13, but not IL-10, was shown to restore the CH reaction to TNCB in IL-4 KO mice. However, IL-4 KO mice developed a normal CH response to oxazolone, indicating that IL-4 was required for the CH reaction to TNCB, but not for that to oxazolone.

Adjuvants, Immunologic↗

PubMed1999

Selection of distinct Valpha/beta T-cell receptor families during in vivo and in vitro T-cell maturation.

The experimental conditions influencing the use of Valphabeta TCR families were examined in lymph node (LN) cells from peptide-immunized C57BL/6 and Vbeta8.2 transgenic mice. Expanded proportions of Vbeta5, Vbeta8.2, Vbeta9, Vbeta12 and Vbeta14 positive cells and an association of Vbeta8.2 with Valpha11 was found in freshly harvested 8-day or 34-day immune LN cells. In contrast, peptide-specific T-cell lines generated in vitro from 8-day immune lymph node cells were found to be almost exclusively of the Valpha2/Vbeta12 family. However, T-cell lines originating from Vbeta8.2 transgenic mice did not show preferential Valpha usage. Anti-Vbeta8.2 antibody produced different effects: when added to cultures of LN cells from C57BL/6 or Vbeta8.2 transgenic strains, the peptide-induced proliferation was suppressed; however, following the injection of mice, subsequent in vitro proliferation and cytokine production induced by both peptide and Concanavalin A was suppressed in Vbeta8.2 transgenic, but much less in C57BL/6 mice. Hence, compensatory expansion of different Vbeta gene products occurred in vivo, but not under the employed in vitro conditions. In conclusion, these results suggest that the TCR family usage is influenced by the experimental conditions in which the T cells are selected and expanded and by the genetic potentials of the precursor pool.

Amino Acid Sequence↗

PubMed1999

Sequestration of T lymphocytes to body fluids in tuberculosis: reversal of anergy following chemotherapy.

The specificity of CD4 T lymphocytes was investigated in 6 patients affected by tuberculosis who had negative tuberculin purified protein derivative (PPD) skin tests at diagnosis. Polyclonal CD4 T cell lines from the peripheral blood failed to proliferate to PPD and to the 16- or 38-kDa proteins of Mycobacterium tuberculosis, while CD4 cell lines from the disease site responded to PPD and to the 16- and 38-kDa proteins and derived epitopes in vitro. Four months after chemotherapy, the patients became responsive to PPD. The proliferative response to PPD and to the 16- or 38-kDa proteins and their derived peptides decreased in CD4 T cell lines from the disease site and increased in lines from the peripheral blood. These results indicate that CD4 T cells recognizing a vast array of M. tuberculosis epitopes are compartmentalized at the site of disease in anergic patients but appear in peripheral blood after chemotherapy.

Antigens, Bacterial↗

PubMed1999

In vivo gammadelta T cell priming to mycobacterial antigens by primary Mycobacterium tuberculosis infection and exposure to nonpeptidic ligands.

BACKGROUND: The recognition of phosphorylated nonpeptidic microbial metabolites by Vgamma9Vdelta2 T cells does not appear to require the presence of MHC molecules or antigen processing, permitting rapid responses against microbial pathogens. These may constitute an important area of natural anti-infectious immunity. To provide evidence of their involvement in immune reactivities against mycobacteria, we measured the responsiveness of peripheral blood Vgamma9Vdelta2 T cells in children with primary Mycobacterium tuberculosis (MTB) infections. MATERIALS AND METHODS: Peripheral blood mononuclear cells from 22 children with MTB infections and 16 positivity of tuberculin (PPD)-negative healthy children were exposed to nonpeptidic antigens in vitro and the reactivity of the Vgamma9Vdelta2 T cell subset with these antigens was determined using proliferation and cytokine assays. Also, responses of gammadelta T cells from rhesus monkeys stimulated with phosphoantigens in vivo were measured. RESULTS: The Vgamma9Vdelta2 T cell responses were highly increased in infected children in comparison with age-matched controls. This augmented Vgamma9Vdelta2 T cell reactivity subsided after successful antibiotic chemotherapy, suggesting that persistent exposure to mycobacterial antigens is required for the maintenance of gammadelta T cell activation in vivo. The in vivo reactivity of Vgamma9Vdelta2 T cells to phosphoantigens was also analyzed in a rhesus monkey model system. Intravenous injections of phosphoantigens induced an activated state of simian Vgamma9Vdelta2 T cells which decreased after 2 months, i.e., with a time course similar to that seen in MTB-infected children. CONCLUSIONS: The increased reactivity of Vgamma9Vdelta2 T cells to phosphoantigens appears to be dependent on constant antigenic exposure. Consequently, the assessment of Vgamma9Vdelta2 responses may be useful for monitoring the efficacy of antimycobacterial therapies.

Animals↗

PubMed1998

Double magnetic stimulation of the motor cortex in amyotrophic lateral sclerosis.

OBJECTIVES: To study the motor cortex circuitry and the motor interhemispheric influences with double magnetic stimulation in patients affected by amystrophic lateral sclerosis. METHODS: We investigated the motor cortex in 21 amyotrophic lateral sclerosis patients (ALS, 10 with bulbar and 11 with spinal onset) with double magnetic stimulation (one shock in each hand area) with 2, 4, 6, 11 and 15 ms delay between shocks and paired magnetic stimulation (both shocks in the same area), with 4, 15, 25, 35, 55, 85, 100, 155, 200 and 255 ms delays, and compared the results with those obtained in normal subjects. RESULTS: Double magnetic stimulation showed reduced interhemispheric facilitatory influences (maximal at 4 ms delay between shocks) when the test shock was applied on the left hemisphere in all patients; whereas no significant differences were observed compared to control (P > 0.05) when it was applied on the right hemisphere in both forms. Inhibitory effects (maximal at 11 ms delay between shocks) were reduced in all patients for both hemispheres (P < 0.05). Paired magnetic stimulations showed decreased inhibitory influences at 100-155 ms delay between shocks. Compared to control, the difference was significant in bulbar (P < 0.05) and spinal onset, but not between onset forms (P > 0.05). Inhibitory effects recorded with a short delay between shocks (4 ms) were not significantly modified in both forms of onset (P > 0.05) as compared to control. There were no facilitatory influences at 15 and 35 ms delays between shocks. CONCLUSIONS: The results suggest that under these test conditions inhibition and facilitation were reduced in the motor cortex in ALS. As inhibitory effects were affected differently, two distinct cortical circuitries could be involved for short and long delays. As GABA neurons altered in ALS have been identified as a subpopulation reactive to parvalbumin, and since only inhibitory effects recorded with long delay between shocks were impaired in ALS, we suggest that this subpopulation of GABA neurons may be involved in the genesis of inhibitory effects recorded with a long delay between shocks.

Adult↗

PubMed1998

Behaviour of human osteoblasts cultured on bioactive glass coatings.

Two new formulations of bioactive glasses were used as coatings on titanium alloy (TiAl6V4) implants for prosthetic applications in the orthopaedic field. The biocompatibility of these bioglasses, as well as their osteoconductive properties, were assessed by employing primary cultures of human osteoblasts. A nonbioactive glass, the titanium alloy and polystyrene surface were used as controls. The results obtained demonstrated that the two bioglasses elicited a rapid and strong proliferative response by osteoblasts, which spread, formed a close layer and then expressed the specific osteoblastic marker i.e. osteocalcin. In comparison, cells grew on the nonbioactive glass to a much minor extent, similar to that of polystyrene control, showing individual cellular elements not forming a compact sheet, but expressed levels of osteocalcin clearly higher than both the polystyrene control and the two bioglasses. Finally, a very low proliferative rate of osteoblasts and the synthesis of hardly detectable osteocalcin amounts were observed with the titanium alloy. In conclusion, our studies indicate that the new bioactive glasses are effective in stimulating osteoblast growth and differentiation.

Alloys↗