Perceptual and linguistic interactions in speeded classification: tests of the semantic coding hypothesis

We tested the semantic coding hypothesis, which states that cross-modal interactions observed in speeded classification tasks arise after perceptual information is recoded into an abstract format common to perceptual and linguistic systems. Using a speeded classification task, we first confirmed the presence of congruence interactions between auditory pitch and visual lightness and observed Garner-type interference with nonlinguistic (perceptual) stimuli (low-frequency and high-frequency tones, black and white squares). Subsequently, we found that modifying the visual stimuli by (a) making them lexical (related words) or (b) reducing their compactness or figural 'goodness' altered congruence effects and Garner interference. The results are consistent with the semantic coding hypothesis, but only in part, and suggest the need for additional assumptions regarding the role of perceptual organization in cross-modal dimensional interactions.

Inhibition of Th1 development and treatment of chronic-relapsing experimental allergic encephalomyelitis by a non-hypercalcemic analogue of 1,25-dihydroxyvitamin D(3)

1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] inhibits production of IL-12, a cytokine involved in the development of Th1 cells and in the pathogenesis of Th1-mediated autoimmune diseases. Here, we show that 1,25(OH)(2)D(3) and a non-hypercalcemic analogue are selective and potent inhibitors of Th1 development in vitro and in vivo without inducing a deviation to the Th2 phenotype. Administration of 1,25(OH)(2)D(3) or its analogue prevents chronic-relapsing experimental allergic encephalomyelitis (CR-EAE) induced by the myelin oligodendrocyte glycoprotein (MOG) peptide 35 - 55 (MOG(35 - 55)) in Biozzi AB / H mice. The inhibition of EAE induction is associated with a profound reduction of MOG(35 - 55)-specific proliferation and Th1 cell development. Importantly, the non-hypercalcemic analogue also provides long-term protection from EAE relapses induced by immunization with spinal cord homogenate when administered for a short time at symptom onset or even after the first peak of disease. Neuropathological analysis shows a reduction of inflammatory infiltrates, demyelinated areas and axonal loss in brains and spinal cords of treated mice. These resuls indicate that inhibition of IL-12-dependent Th1 cell development is associated with effective treatment of CR-EAE and suggest the feasibility of an approach based on low molecular weight inhibitors of IL-12 production in the treatment of multiple sclerosis.

[Facial rejuvenation with chemical peeling using phenol (Exoderm)]

The authors report their personal experience in the treatment of the resurfacing by means of phenol chemical peeling using a new solution described by Dr. Yoram Fintsi and called Exoderm. They report dressing technique and possible contraindications as well.

Peripheral levels of caspase-1 mRNA correlate with disease activity in patients with multiple sclerosis; a preliminary study

The cysteine protease caspase-1 plays a crucial part in the inflammatory process due to its ability to proteolitically activate proinflammatory cytokine precursors, such as interleukin (IL)-1beta and IL-18. Multiple sclerosis is a chronic inflammatory demyelinating disease of the CNS in which the pathogenic process is mainly orchestrated by proinflammatory cytokines. The role of caspase-1 in multiple sclerosis was evaluated by measuring its mRNA levels in peripheral blood mononuclear cells (PBMCs) from seven patients with relapsing-remitting multiple sclerosis every 15 days over a 1 year period. The recorded levels were compared with clinical and MRI evidence of disease activity. Brain MRI was performed monthly in each patient. Caspase-1 mRNA levels were significantly increased in PBMCs from patients with multiple sclerosis compared with healthy controls (p<0.001). In patients with multiple sclerosis, a twofold to threefold increase of caspase-1 mRNA mean level was found in the week preceding an acute attack (p<0. 05). The magnitude of caspase-1 mRNA increase correlated with the number of new (p=0.01) but not persisting gadolinium enhancing brain MRI lesions. In conclusion, caspase-1 might be involved in the immune mediated process underlying CNS inflammation and might represent a suitable peripheral immunological marker of disease activity in multiple sclerosis.

Method for intracellular magnetic labeling of human mononuclear cells using approved iron contrast agents

A method for intracellular iron labeling of human mononuclear cells (lymphocytes and monocytes) for magnetic resonance imaging (MRI) using simple incubation of cells with approved MRI iron contrast agents is presented. Labeled cells can be detected by MRI in vitro, and this suggests the possibility that the technique could become a marker for in vivo lymphocyte and monocyte trafficking studies in acute inflammatory lesions such as those in Multiple Sclerosis.

Duodenal ulcer relapse is not always associated with recurrence of H. pylori infection: a prospective three-year follow-up study

BACKGROUND

Long-term data concerning the reappearance of Helicobacter pylori infection and duodenal ulcer (DU) recurrence after successful eradication are still few and conflicting. Inadequate histological assessment or use of indirect tests for the determination of H. pylori and bias in the selection of patients to be controlled can influence reported results. The aim of this study was to determine the rate of recurrence of H. pylori infection and ulcer relapse in a population of cured DU patients followed up for 3 years irrespective of their symptomatology.

METHODS

Between 1992 and 1994, 126 patients with DU disease were treated with double or triple therapy. Patients using nonsteroidal antiinflammatory drugs or aspirin or receiving maintenance antisecretory therapy were excluded. H. pylori infection was assessed by three bioptic tests from both the antrum and the body (culture, urease, histopathological examination). After 2 months from cessation of treatment, DU had healed and H. pylori infection was cured in 102 of 126 patients (81%). These patients were endoscopically followed up after 1 and 3 years, respectively, and were advised to contact us at symptom recurrence. At 1 and 3 years, we studied 95 (93.2%) and 79 (77.4%) patients, respectively, of the 102 who were cured. The other patients were untraceable or refused endoscopy because they were asymptomatic.

RESULTS

After 1 year, no patient had H. pylori recurrence, whereas three patients had a relapse of DU without evidence of infection. After 3 years, recurrence of H. pylori occurred in six patients (annual rate, 2.5%), DU relapsed in five H. pylori-positive patients (6.3%) and in two H. pylori-negative patients (annual rate, 1.9%). Fasting gastrin and acid secretion values studied in all relapsed patients were within the normal range except for one H. pylori-positive patient.

CONCLUSIONS

Recurrence of H. pylori infection is very low where treatment is effective, but a DU relapse, not related to acid hypersecretion, can occur in a small percentage of cured patients.

Reversal of iron deficiency anemia after Helicobacter pylori eradication in patients with asymptomatic gastritis

BACKGROUND

Iron deficiency anemia is the most common form of anemia worldwide. Recent studies have suggested an association between Helicobacter pylori infection and iron deficiency.

OBJECTIVE

To investigate the effects of eradicating H. pylori with combination antibiotic therapy on iron deficiency anemia in patients with H. pylori-associated gastritis.

DESIGN

Case series.

SETTING

University hospital.

PATIENTS

30 patients with a long history of iron deficiency anemia in whom H. pylori-associated gastritis was the only pathologic gastrointestinal finding detected.

INTERVENTION

Eradication therapy with two antibiotics and discontinuation of iron replacement therapy.

MEASUREMENTS

Complete blood count, ferritin levels, and gastroscopy with biopsy to evaluate H. pylori status.

RESULTS

At 6 months, 75% of patients had recovered from anemia (P<0.001), ferritin values increased from 5.7+/-0.7 microg/L to 24.5+/-5.2 microg/L (95% CI, 8.85 to 29.97). After 12 months, 91.7% of patients had recovered from anemia.

CONCLUSIONS

Cure of H. pylori infection is associated with reversal of iron dependence and recovery from iron deficiency anemia.

Efficacy of 51Cr-EDTA clearance to tailor a carboplatin therapeutic regimen in ovarian cancer patients

AIM

The aim of this study was to evaluate the efficacy of 51Cr-EDTA clearance to tailor the carboplatin dose in two different therapeutic regimens of advanced epithelial ovarian cancer.

MATERIALS AND METHODS

14 patients entered the study, eight treated by carboplatin (C) alone and six by C and paclitaxel (P). The dose of C was calculated from the Calvert formula [DOSE(mg) = desired AUC x (GFR + 25)] based on the Glomerular filtration rate (GFR) figure; in our protocol desired Area under the curve (AUC) figure was 5 mg/ml x min. The method used to calculate the GFR requires only 4 blood samples taken in the late part of the disappearance plasmatic curve and conjugates accuracy to an acceptable clinical compliance.

RESULTS

In only 5 courses a significant hematological toxicity (HT) was present (4 courses grade 2, 1 course grade 3); it was necessary to delay only 2 courses; no treatment was discontinued because of HT.

CONCLUSION

We concluded that there is no summation toxicity of C and P if administered simultaneously and that the assessment of GFR by 51Cr-EDTA clearance is an optimal tool to predict an acceptable toxicity.

[Gastric leiomyoma. Diagnostic and surgical problems]

The Authors report their three year experience with five patients suffering from gastric leiomyoma, each with different anatomical and clinical characteristics. The Authors have performed a research of the different diagnostics, clinical and therapeutic problems of these rare tumors that sometimes are asymptomatic in spite of the large size they reach, but more frequently they present with haemorrhagic symptoms which tend to point to other more frequent pathological conditions. Diagnosis can only be suspected, but cannot be reached without a histological examination, also if the classifications of these tumors have been argument of many changes, particularly by the light of the recent diagnostics possibilities offered by ultrastructural and immunohistochemical examination.

The fluorescent cationic dye rhodamine 6G as a probe for membrane potential in bovine aortic endothelial cells

The membrane potential of cultured bovine aortic endothelial cells was assessed by a fluorescent probe as an alternative to direct methods. We used the fluorescent cationic dye rhodamine 6G, a lipophilic probe with high permeability in cell membranes. A linear relationship was obtained between fluorescence intensity (F.I.) and membrane potential (Em) as a function of the extracellular Na(+) concentration in the presence of the ionophore gramicidin. From the equation derived from the linear relationship F.I. = -0.004 Em + 0. 03 (P < 0.001), the fluorescence measurements could be converted to membrane potential. The resting plasma membrane potential obtained was -65 +/- 7 mV. Nigericin (27 microM), ouabain (1 mM), and bradykinin (20 nM) induced a decrease in F.I. (depolarization), while ATP (25-100 microM) induced an increase in F.I. (hyperpolarization). Mitochondrial membrane potential inhibitors myxothiazol (3 microM) and oligomycin (4 microM) did not influence F. I. measured in the cultured bovine aortic endothelial cells. The results indicate that rhodamine 6G can be used as a sensitive and specific dye in studies of substances that affect the membrane potential of endothelial cells.

Tumor necrosis factor-alpha and its soluble receptors in plasma and cerebrospinal fluid of multiple sclerosis patients treated with methylprednisolone

Demyelination is the main pathological feature of multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system. Tumor necrosis factor-alpha (TNF-alpha) can cause myelin damage and contribute to MS pathogenesis. We measured plasma and cerebrospinal fluid (CSF) levels of TNF-alpha and its soluble receptors, TNF-sRp55 and TNF-sRp75, in 18 patients with active MS, and in neurological and healthy controls. The same determinations were repeated on plasma and on CSF samples that were collected after the MS patients had ended a six-day treatment with high-dose methylprednisolone (MP). Pre- and post-treatment plasma and CSF TNF-alpha levels, when detectable, and those of TNF-sRp75, did not vary, and were similar to those of controls. CSF TNF-sRp55 levels were higher in acute MS patients than in controls. Post-treatment CSF TNF-sRp55 levels were higher than in the active phase of the disease. The MS patients, who clinically improved, tended to have the highest CSF TNF-sRp55 levels. The increase was due to intrathecal TNF-sRp55 synthesis. Although it is involved in MS pathogenesis, TNF-alpha is not detectable in plasma or in CSF samples from MS patients in various phases of the disease. A better marker of disease activity seems to be CSF TNF-sRp55 levels. The increased CSF levels of TNF-sRp55 in response to MP circumstantially suggest that this receptor could partially account for the beneficial effects of MP in acute MS.

Caspase-1 regulates the inflammatory process leading to autoimmune demyelination

T cell-mediated inflammation is considered to play a key role in the pathogenic mechanisms sustaining multiple sclerosis (MS). Caspase-1, formerly designated IL-1beta-converting enzyme, is crucially involved in immune-mediated inflammation because of its pivotal role in regulating the cellular export of IL-1beta and IL-18. We studied the role of caspase-1 in experimental autoimmune encephalomyelitis (EAE), the animal model for MS. Caspase-1 is transcriptionally induced during EAE, and its levels correlate with the clinical course and transcription rate of proinflammatory cytokines such as TNF-alpha, IL-1beta, IFN-gamma, and IL-6. A reduction of EAE incidence and severity is observed in caspase-1-deficient mice, depending on the immunogenicity and on the amount of the encephalitogenic myelin oligodendrocyte glycoprotein (MOG) peptide used. In caspase-1-deficient mice, reduced EAE incidence correlates with defective development of anti-MOG IFN-gamma-producing Th1 cells. Finally, pharmacological blockade of caspase-1 in Biozzi AB/H mice, immunized with spinal cord homogenate or MOG35-55 peptide, by the caspase-1-inhibitor Z-Val-Ala-dl -Asp-fluoromethylketone, significantly reduces EAE incidence in a preventive but not in a therapeutic protocol. These results indicate that caspase-1 plays an important role in the early stage of the immune-mediated inflammatory process leading to EAE, thus representing a possible therapeutic target in the acute phase of relapsing remitting MS.

Relevance of interleukin 1 receptor antagonist intron 2 polymorphism in Italian MS patients

The A1/A1 genotype of the anti-inflammatory cytokine interleukin 1 receptor antagonist (IL-1Ra) polymorphism was more frequent in 339 Italian MS patients than in healthy controls (HCs) (odds ratio = 1.83). A more aggressive disease course was also associated with A1+ genotypes and might reflect the reduced ability of mononuclear cell cultures of A1+ HCs to produce IL-1Ra. We conclude that an IL-1Ra gene polymorphism is associated with occurrence of disease and clinical course variability in Italian MS patients.

Immunopathogenesis of multiple sclerosis: the role of T cells

Multiple sclerosis is considered to be an autoimmune disease that results from aberrant immune responses to central nervous system antigens. T cells are considered to be crucial in orchestrating an immunopathological cascade that culminates in damage to the myelin sheath, oligodendrocytes and axons.

Effector pathways in immune mediated central nervous system demyelination

Multiple sclerosis is generally regarded to be a primarily T-cell driven disease. Recent evidence has refocused interest on antibodies. Adhesion molecules, matrix metalloproteinases, chemokines and cytokines, and nitric oxide and oxygen metabolites all participate in the amplification and effector stages of the disease.

TE671 cell-based ELISA for anti-acetylcholine receptor antibody determination in myasthenia gravis

BACKGROUND

Acetylcholine receptor (AChR) from human muscles is the antigen used currently in radioimmunoprecipitation assays (RIPAs) for the determination of anti-AChR antibodies in the diagnosis of myasthenia gravis (MG). Our aim was to develop and validate an ELISA using TE671 cells as the source of AChR.

METHODS

After TE671 cell homogenization, the crude AChR extract was used for plate coating. Anti-AChR antibodies were determined in 207 MG patients and in 77 controls.

RESULTS

The mean intra- and interassay CVs (for two samples with different anti-AChR antibody concentrations) were 9.7% and 15.7%, respectively. Test sensitivity and specificity, for generalized MG, were 79.5% (95% confidence interval, 72.8-85.0%) and 96.1% (89.0-99.1%). The detection limit was 2 nmol/L. Anti-AChR antibody concentrations from 53 MG patients, as tested with our ELISA, showed good agreement with an RIPA with a mean difference (SD) of 1.0 (5.6) nmol/L.

CONCLUSION

Our ELISA is a simple screening test for the diagnosis of MG and enables rapid and inexpensive patient follow-up.

The effect of clozapine on aggressive behaviour in patients with chronic schizophrenia

We studied the effect of 12 months' treatment with clozapine (150-400 mg/day) in 16 chronic schizophrenic patients with aggressive behaviour. The number of aggressive episodes, the time spent in seclusion and physical restraint, and the number of pharmacological interventions used as chemical restraint during the 12 months of clozapine treatment were calculated and compared to those for the previous 12-month period (during which treatment was with conventional antipsychotics). During clozapine therapy there was a statistically significant decrease (P<0.001) in all the parameters of aggressive behaviour which we investigated, as compared with the pre-clozapine period. The reduction in aggressive behaviour was more prominent within the first 6 months of clozapine administration. Clozapine treatment was also associated with a global improvement in psychosis, as measured by the Brief Psychiatric Rating Scale. Despite the limitations in sample size and study design, our results confirm that clozapine appears more effective than classical antipsychotics in reducing aggressive behaviour in chronic schizophrenic patients.

Central nervous system delivery of interleukin 4 by a nonreplicative herpes simplex type 1 viral vector ameliorates autoimmune demyelination

Multiple sclerosis (MS) is a T cell-mediated organ-specific inflammatory disease leading to central nervous system (CNS) demyelination. On the basis of results obtained in experimental autoimmune encephalomyelitis (EAE) models, MS treatment by administration of antiinflammatory cytokines such as interleukin 4 (IL-4) is promising but is hampered by the limited access of the cytokines to the CNS and by the pleiotropic effects of systemically administered cytokines. We established a cytokine delivery system within the CNS using non-replicative herpes simplex type 1 (HSV-1) viral vectors engineered with cytokine genes. These vectors injected into the cisterna magna (i.c.) of mice diffuse in all ventricular and subarachnoid spaces and infect with high efficiency the ependymal and leptomeningeal cell layers surrounding these areas, without obvious toxic effects. Heterologous genes contained in the vectors are efficiently transcribed in infected ependymal cells, leading to the production of high amounts of the coded proteins. For example, 4.5 ng of interferon gamma (IFN-gamma) per milliliter is secreted into the cerebrospinal fluid (CSF) up to day 28 postinjection (p.i.) and reaches the CNS parenchyma in bioactive form, as demonstrated by upregulation of MHC class I expression on CNS-resident cells. We then exploited the therapeutic potential of the vectors in EAE mice. An HSV-1-derived vector containing the IL-4 gene was injected i.c. in Biozzi AB/H mice at the time of EAE induction. We found the following in treated mice: (1) delayed EAE onset, (2) a significant decrease in clinical score, (3) a significant decrease in perivascular inflammatory infiltrates and in the number of macrophages infiltrating the CNS parenchyma and the submeningeal spaces, and (4) a reduction in demyelinated areas and axonal loss. Peripheral T cells from IL-4-treated mice were not affected either in their antigen-specific proliferative response or in cytokine secretion pattern. Our results indicate that CNS cytokine delivery with HSV-1 vectors is feasible and might represent an approach for the treatment of demyelinating diseases. Advantages of this approach over systemic cytokine administration are the high cytokine level reached in the CNS, the absence of effects on the peripheral immune system, and the long-lasting cytokine production in the CNS after a single vector administration.

IL-12 is involved in the induction of experimental autoimmune myasthenia gravis, an antibody-mediated disease

IL-12 has been shown to be involved in the pathogenesis of Th1-mediated autoimmune diseases, but its role in antibody-mediated autoimmune pathologies is still unclear. We investigated the effects of exogenous and endogenous IL-12 in experimental autoimmune myasthenia gravis (EAMG). EAMG is an animal model for myasthenia gravis, a T cell-dependent, autoantibody-mediated disorder of neuromuscular transmission caused by antibodies to the muscle nicotinic acetylcholine receptor (AChR). Administration of IL-12 with Torpedo AChR (ToAChR) to C57BL/6 (B6) mice resulted in increased ToAChR-specific IFN-gamma production and increased anti-ToAChR IgG2a serum antibodies compared with B6 mice primed with ToAChR alone. These changes were associated with earlier and greater neurophysiological evidence of EAMG in the IL-12-treated mice, and reduced numbers of AChR. By contrast, when IL-12-deficient mice were immunized with ToAChR, ToAChR-specific Th1 cells and anti-ToAChR IgG2a serum antibodies were reduced compared to ToAChR-primed normal B6 mice, and the IL-12-deficient mice showed almost no neurophysiological evidence of EAMG and less reduction in AChR. These results indicate an important role of IL-12 in the induction of an antibody-mediated autoimmune disease, suggest that Th1-dependent complement-fixing IgG2a anti-AChR antibodies are involved in the pathogenesis of EAMG, and help to account for the lack of correlation between anti-AChR levels and clinical disease seen in many earlier studies.

Magnetization transfer changes in the normal appearing white matter precede the appearance of enhancing lesions in patients with multiple sclerosis

Serial monthly magnetization transfer (MT) imaging was performed to evaluate whether a change of the normal appearing white matter (NAWM), which precedes the appearance of enhancing lesions, is seen in patients with multiple sclerosis (MS). Every 4 weeks for 3 months, 10 patients with relapsing-remitting MS were scanned with a T1-weighted sequence, 20 minutes after injection with 0.3 mmol/kg gadolinium-DTPA (Gd-DTPA). During each of the monthly sessions, MT and dual echo scans were also performed before Gd-DTPA injection. On coregistered images, the MT ratio (MTR) was measured in NAWM subsequently involved by enhancing lesions, in NAWM areas on the same slices but outside any present or future MR abnormality, and in enhancing lesions at the time of their appearance. Forty-eight new enhancing lesions with no corresponding abnormalities on previous scans were identified. Their average MTR was 33.1% (+/-8.4%). Three, 2, and 1 month before enhancement appearance, the mean MTR in NAWM, measured from areas corresponding to future enhancing lesions, was significantly lower than the mean MTR in NAWM outside enhancing areas; the MTR decreased steadily as the time when the enhanced lesion approached. These results suggest that changes in the NAWM of patients with MS occur before lesions become evident on conventional MRI scans.