Weighing the evidence for cross over in neglect

When patients with left-sided neglect are asked to bisect horizontal lines, they tend to place their marks to the right of the line's objective mid-point. However, when asked to bisect short lines they are either more accurate or paradoxically cross over and place their marks to the left of the objective mid-point. Previous explanations of the cross over phenomenon have considered specific aberrations of spatial attention. However, these explanations make no predictions about judgments of non-spatial stimuli. Two patients with right brain damage were asked to judge weights placed on both hands simultaneously. They were biased in reporting weights on the right as being heavier than those on the left. This rightward bias changed with lighter pairs of weights presented in the context of equal reference weights. In one patient the directional bias was eliminated and in the other the bias was reversed so that she was more likely to report the left weight as heavier than the right. These data suggest that a phenomenon analogous to cross over in line bisections also occurs with judgments of non-spatial stimuli. Representations of stimuli appear to be influenced by features of the stimuli encountered on-line and by memory traces of similar stimuli encountered previously. With an attentional deficit, memory traces influence the magnitude of the representation derived on-line disproportionately.     

Differential scanning calorimetry differences in micronized and unmicronized nimesulide uptake processes in biomembrane models.

Nimesulide release from micronized and unmicronized drug particles was tested at pH 7.4 by measuring the transfer to dimyristoylphosphatidylcholine liposomes (multilamellar and unilamellar vesicles), chosen as a biomembrane model. The perturbing effect of increasing molar fractions of pure nimesulide on the thermotropic behaviour of dimyristoylphosphatidylcholine liposomes was investigated by differential scanning calorimetry. In order to study the drug dissolution process by its uptake into void liposomes, measurements were carried out on suspensions of blank liposomes added to weighed amounts of free powdered nimesulide (micronized and unmicronized). The amount of drug transferred was quantified by comparing the effect caused by the dissolved and released drug to that caused by the free drug that had been previously molecularly dissolved in the liposomes. The calorimetric results show that the dissolution rate depends on the nimesulide form (micronized or unmicronized), and that the transfer to the void liposomes is quicker when the drug is in a micronized form. The uptake was faster when unilamellar vesicles were used instead of multilamellar vesicles because of the greater lipid surface. The calorimetric technique could represent an alternative 'in vitro' method that can be applied to the study of the dissolution kinetics directly at the site of drug uptake, mimicking a biological system.     

Prognostic value of CD40 in adult soft tissue sarcomas.

PURPOSE: The purpose is to evaluate the expression of CD40, a membrane protein predominantly expressed on B cells, dendritic cells, and macrophages, in a series of adult soft tissue sarcomas and to test its possible prognostic value. EXPERIMENTAL DESIGN: CD40 expression was studied by immunohistochemistry. Correlations with other baseline characteristics of patients and tumors were analyzed with chi(2) test. The prognostic value was studied with univariable and multivariable analysis adjusted by age, sex, tumor size, grade, location, and distant metastases. RESULTS: Eighty-two patients, between January 1994 and May 2001, were analyzed. Membrane or cytoplasmic staining for CD40 protein was absent in 30% of the tumors but present in <10% of cells in 22 (27%), in 10% to 50% in 23 (28%), and in >50% of cells in 12 (15%) tumors. There was no correlation between CD40 expression and age, sex, size, grade, and location of the primary tumor and distant metastases. With 61 patients (74.4%) progressed and 31 (37.8%) dead, CD40 expression was a significant prognostic factor for disease-free and overall survival at univariable and multivariable analysis. Patients with tumors expressing CD40 in >50% of cells had a dramatically unfavorable prognosis with median disease-free and overall survival of 7 and 17 months, respectively, and hazard ratios of relapse and death as compared with patients with CD40-negative tumors of 2.89 (95% confidence interval: 1.26-6.60) and 6.92 (95% confidence interval: 2.18-22.0), respectively. CONCLUSIONS: These data suggest that expression of CD40 protein in >50% of cells might indicate an unfavorable prognosis in adult soft tissue sarcomas.     

The conjugate Rituximab/saporin-S6 completely inhibits clonogenic growth of CD20-expressing cells and produces a synergistic toxic effect with Fludarabine.

Immunotoxins are chimeric proteins consisting of a toxin coupled to an antibody. To date, several clinical trials have been conducted, and some are still ongoing, to evaluate their anti-tumor efficacy. In this view, we chemically constructed an anti-CD20 immunotoxin with the mAb Rituximab and the type 1 ribosome-inactivating protein (RIP) saporin-S6, designed for B cells non-Hodgkin's lymphoma (NHL) therapy. This immunotoxin showed a specific cytotoxicity for the CD20+ cell lines Raji and D430B, evidenced by inhibition of protein synthesis, evaluation of apoptosis and clonogenic assay. Upon conjugation, saporin-S6 increased its toxicity on target cells by at least 2 logs, with IC(50) values of 0.1-0.3 nM. The percentage of AnnexinV+ cells was over 95% in both cell lines treated with 10 nM immunotoxin. A complete elimination of Raji clones was reached with the 10 nM immunotoxin, whereas a mixture of free RIP and mAb gave about 90% of clonogenic growth. Rituximab/saporin-S6, at 10 nM concentration, also induced apoptosis in 80% of lymphoma cells from NHL patients. Moreover, sensitivity of Raji to Rituximab/saporin-S6 was augmented when cells were coincubated with Fludarabine. The synergistic toxic effect of the two drugs led to a total elimination of the neoplastic population.     

Stroma cells: a novel target of herceptin activity.

PURPOSE: Stroma cells play a relevant role in tumor development and progression. We investigated the activity of herceptin (HER), a humanized monoclonal antibody widely used for the treatment of HER2-overexpressing epithelial cancer, toward stroma cell lines L87/4 and L88/5. EXPERIMENTAL DESIGN: We studied the antiproliferative potential of HER and role of human serum in HER activity. We also investigated the ability of HER to alter ancillary functions of L87/4 and L88/5, such as support to long-term hematopoiesis, growth factor production, breast cancer cell adhesion, and proliferation. RESULTS: Flow cytometry showed that HER2 membrane expression in L87/4 and L88/5 stroma cells was intermediate between the expression in HER2-negative/dim MCF-7 breast cancer cells and HER2-bright SK-BC3 breast cancer cells. HER2 gene amplification was not detected by fluorescence in situ hybridization in either stromal cell lines. HER significantly inhibited L87/4 and L88/5 proliferation. Mean ID(50)s were found to be 2000 and 1700 micro g/ml for L87/4 and L88/5, respectively, after 3-day exposure and 800 micro g/ml for both cell lines after 9-day exposure. The presence of 10% human serum in the culture increased HER inhibitory activity. IC(50) of stroma cells was found to be intermediate between HER2-bright breast cancer cells (SK-BC3) and HER2-negative/dim breast cancer cells (MCF-7). The drug did not significantly affect the ability of stroma cells to support long-term hematopoiesis in the cobblestone area forming cell assay. In contrast, in coculture assay, MCF7 cells demonstrated a worse adhesion and growth capability on HER-treated stroma layers when compared with untreated stroma. Moreover, HER significantly reduced vascular endothelial growth factor production by L88/5 cells. CONCLUSIONS: Our data support the novel finding that HER may have a relevant activity against stroma cells.     

Microanatomical localization of dopamine receptor protein immunoreactivity in the rat cerebellar cortex

Dopamine (DA) receptor subtype localization was investigated in rat cerebellar cortex using immunohistochemical techniques with antibodies raised against D1-D5 receptor protein. A faint D1 receptor protein immunoreactivity was developed in molecular and Purkinje neurons layers. D2 receptor protein immunoreactivity was found primarily in cerebellar white matter followed by molecular and granular layers and Purkinje neurons. Antibodies against D2S receptor protein were localized in molecular layer and to a lesser extent, in granular layer. A few Purkinje neurons displayed a faint D2S receptor protein immunoreactivity. D3 receptor protein immunoreactivity was observed primarily in molecular and in Purkinje neurons layers of lobules 9 and 10. A faint D3 receptor protein immunoreactivity was also localized in Purkinje neurons and to a lesser extent, in molecular and granular layers of cerebellar lobules 1-8. D4 receptor protein immunoreactivity was found in cerebellar white matter. A pale immunostaining was also visualized in molecular layer. D5 receptor protein immunoreactivity was localized primarily in molecular and Purkinje neurons layers and to a lesser extent, in granular layer and in white matter. The above results indicate that rat cerebellar cortex expresses the DA receptor subtypes so far identified. Purkinje neurons, which are the only efferent neurons of cerebellum, are richest in DA receptor protein immunoreactivity. This suggests that dopaminergic neurotransmission may modulate efferent inputs from cerebellum. The localization of the majority of D2 and D4 and of a faint D5 protein receptor immunoreactivity in cerebellar white matter suggests that these receptors may be presynaptic and transported axonally.     

Tentorial Meningiomas. Report on Twenty-Seven Cases

Summary ? Objective. Report our experience with 27 tentorial meningiomas (TM) surgically treated between 1985 and 1998.  Methods. The records of 27 patients with TMs were retrospectively reviewed for clinical presentation, neuroradiological evaluation, surgical treatment and long-term outcome. The extent of tumor resection was scored according to the Simpson's grading for tumor removal. Long-term results were evaluated according to the Glasgow Outcome Score (GOS).  Results. The average age was 53 years. Female predominance was 74%. The most common complaints at presentation were headaches (51%), gait ataxia (33%), memory disturbances (30%) and hypo-acousia (30%). A classification of TMs into 5 subgroups according to tumor site is proposed on the basis of imaging studies. A cerebrospinal fluid shunt was established prior to direct approach in 7 patients and as the sole procedure in one inoperable patient. Twenty-seven direct approaches were undertaken in 26 patients, including 17 infratentorial and 10 supratentorial approaches. Total tumor removal was achieved in 20 patients (77%) and subtotal removal in 6 (23%). Fifteen patients (55%) experienced 22 postoperative complications. One patient died three months after a subtotal resection (mortality=3,7%). With a mean follow-up of 54 months, all 26 survivors are currently alive with 23 having resumed their normal activities and 3 needing assistance. Five of 6 patients with subtotal resection survived and were followed for a period ranging from 72 to 132 months: none showed residual tumor progression and no re-operation was considered. An additional patient experienced a ?true? recurrence 6 years after total removal, with no tumor progression 2 years after his recurrence was recognized.  Discussion. The best surgical approach to TMs is still a controversial matter. The advantages and drawbacks of conventional versus transbasal approaches are reviewed. Our experience suggests that subtotal removal can be associated with long recurrence-free intervals and preserved quality of life. TMs located at the tentorial edge carried a definitely worse prognosis than peripheral forms.     

Piracetam in acute stroke: a systematic review

We studied whether the administration of piracetam in acute, presumed ischemic stroke affects case fatality and functional outcome. The Cochrane Stroke Group strategy was used to evaluate all randomized controlled trials of patients with presumed ischemic stroke examined within 48 h; death and (when available) functional outcome were used as end points. Three studies were included; the most recent one contributed more than 97% of the data. There were 501 patients treated with piracetam and 501 controls. Piracetam was associated with a nonsignificant 31% increase in the odds of death (95% CI –5% to 81%). This result was due almost completely to the effect of the larger trial, which, however, reported that the difference in case fatality rate between piracetam and control disappeared after correcting for the imbalance in stroke severity between the two groups. Data on functional outcome were available only for the largest study, and no difference was reported. Data obtained from the manufacturer suggested a nonsignificant trend (–10%) towards reduction in dependency with piracetam (CI –33% to 20%); the proportions of patients dead or dependent in the two groups were the same. Relevant adverse effects were not reported. The evidence from this review does not support routine administration of piracetam in patients with acute ischemic stroke; however, since a possible beneficial effect cannot completely be ruled out, further controlled trials are warranted. Received: 31 August 1999/Received in revised form: 3 November 1999/Accepted: 25 November 1999     

From target identification to drug screening assays for neurodegenerative diseases.

Treatment of neurodegenerative diseases represents a major challenge for the pharmaceutical industry. Key to developing novel and efficacious therapeutics is the discovery of new druggable targets. Toward this aim, the current drug discovery process is strongly relying on the improved understanding of disease mechanisms and on a synergistic approach with chemistry, molecular biology and robotics. In this scenario, we present the case of a newly discovered molecular mechanism that may be of interest for drug discovery programmes in Huntington's disease and other neurodegenerative diseases.