Arturo Brunetti

Effect of Continuous Intravenous Infusion of Zidovudine (AZT) in Children with Symptomatic HIV Infection

Abstract To produce concentrations of zidovudine (AZT) in plasma and cerebrospinal fluid that would provide constant inhibition of the replication of human immunodeficiency virus (HIV), we gave AZT by continuous intravenous infusion to 21 children ranging in age from 14 months to 12 years who had acquired HIV infection through transfusions or perinatally. All patients were symptomatic before AZT treatment (Class P2 of the Centers for Disease Control); 13 (62 percent) had evidence of neurodevelopmental abnormalities. The mean CD4/CD8 ratio was 0.18; 11 patients had CD4 counts below 0.2X109 per liter. We administered AZT at four dose levels: 0.5, 0.9, 1.4, and 1.8 mg per kilogram of body weight per hour. The plasma drug concentrations achieved at the respective dose levels were 1.9±0.3, 2.8±1.4, 3.1 ±1.1, and 4.5±1.0 μM. The steady-state cerebrospinal fluid:plasma ratio was 0.24±0.07. The only evidence of toxicity was bone marrow suppression. Transfusion was required in 14 patients because of low levels of ...

MicroRNA-199b-5p Impairs Cancer Stem Cells through Negative Regulation of HES1 in Medulloblastoma

Background Through negative regulation of gene expression, microRNAs (miRNAs) can function in cancers as oncosuppressors, and they can show altered expression in various tumor types. Here we have investigated medulloblastoma tumors (MBs), which arise from an early impairment of developmental processes in the cerebellum, where Notch signaling is involved in many cell-fate-determining stages. MBs occur bimodally, with the peak incidence seen between 3–4 years and 8–9 years of age, although it can also occur in adults. Notch regulates a subset of the MB cells that have stem-cell-like properties and can promote tumor growth. On the basis of this evidence, we hypothesized that miRNAs targeting the Notch pathway can regulated these phenomena, and can be used in anti-cancer therapies. Methodology/Principal Findings In a screening of MB cell lines, the miRNA miR-199b-5p was seen to be a regulator of the Notch pathway through its targeting of the transcription factor HES1. Down-regulation of HES1 expression by miR-199b-5p negatively regulates the proliferation rate and anchorage-independent growth of MB cells. MiR-199b-5p over-expression blocks expression of several cancer stem-cell genes, impairs the engrafting potential of MB cells in the cerebellum of athymic/nude mice, and of particular interest, decreases the MB stem-cell-like (CD133+) subpopulation of cells. In our analysis of 61 patients with MB, the expression of miR-199b-5p in the non-metastatic cases was significantly higher than in the metastatic cases (P = 0.001). Correlation with survival for these patients with high levels of miR-199b expression showed a positive trend to better overall survival than for the low-expressing patients. These data showing the down-regulation of miR-199b-5p in metastatic MBs suggest a potential silencing mechanism through epigenetic or genetic alterations. Upon induction of de-methylation using 5-aza-deoxycytidine, lower miR-199b-5p expression was seen in a panel of MB cell lines, supported an epigenetic mechanism of regulation. Furthermore, two cell lines (Med8a and UW228) showed significant up-regulation of miR-199b-5p upon treatment. Infection with MB cells in an induced xenograft model in the mouse cerebellum and the use of an adenovirus carrying miR-199b-5p indicate a clinical benefit through this negative influence of miR-199b-5p on tumor growth and on the subset of MB stem-cell-like cells, providing further proof of concept. Conclusions/Significance Despite advances in our understanding of the pathogenesis of MB, one-third of these patients remain incurable and current treatments can significantly damage long-term survivors. Here we show that miR-199b-5p expression correlates with metastasis spread, identifying a new molecular marker for a poor-risk class in patients with MB. We further show that in a xenograft model, MB tumor burden can be reduced, indicating the use of miR199b-5p as an adjuvant therapy after surgery, in combination with radiation and chemotherapy, for the improvement of anti-cancer MB therapies and patient quality of life. To date, this is the first report that expression of a miRNA can deplete the tumor stem cells, indicating an interesting therapeutic approach for the targeting of these cells in brain tumors.

Grey matter loss in relapsing-remitting multiple sclerosis: a voxel-based morphometry study.

Global grey matter (GM) loss has been reported in multiple sclerosis (MS). We addressed the question of if and where GM loss is localized by means of optimized voxel-based morphometry, applied to MRI studies of 51 patients with clinically defined relapsing-remitting MS and 34 age-matched normal subjects, segmented into normal and abnormal brain tissues using a multiparametric approach. Segmented GM volumes were subsequently compared on a voxel-by-voxel basis to highlight regions of relative GM loss (P < 0.05, corrected for multiple comparisons at AnCova). Additionally, localized differences in brain asymmetry between the MS and the control groups were assessed by comparing on a voxel-by-voxel basis maps of GM differences between the two hemispheres (P < 0.05 corrected for multiple comparisons). In MS patients, GM volume was significantly decreased at the level of the left fronto-temporal cortex and precuneus, as well as of anterior cingulate gyrus and of caudate nuclei bilaterally. The only cortical region of significant GM loss in the right hemisphere was located in the postcentral area. Furthermore, GM loss regions were colocalized with increased GM asymmetries (Left < Right) in MS, confirming a preferential left-sided GM loss. Caudate atrophy correlated with lesion load, while no correlation between cortical regional GM loss and disease duration, clinical status or lesion load emerged. Our findings suggest that in RR-MS cortical GM reduction preferentially involves left fronto-temporal structures and deep GM, the latter correlating preferentially to global lesion load.

Brain atrophy and lesion load in a large population of patients with multiple sclerosis

Objective: To measure white matter (WM) and gray matter (GM) atrophy and lesion load in a large population of patients with multiple sclerosis (MS) using a fully automated, operator-independent, multiparametric segmentation method. Methods: The study population consisted of 597 patients with MS and 104 control subjects. The MRI parameters were abnormal WM fraction (AWM-f), global WM-f (gWM-f), and GM fraction (GM-f). Results: Significant differences between patients with MS and control subjects included higher AWM-f and reduced gWM-f and GM-f. MRI data showed significant differences between patients with relapsing-remitting and secondary progressive forms of MS. Significant correlations between MRI parameters and between MRI and clinical data were found. Conclusions: Patients with multiple sclerosis have significant atrophy of both white matter (WM) and gray matter (GM); secondary progressive patients have significantly more atrophy of both WM and GM than do relapsing-remitting patients and a significantly higher lesion load (abnormal WM fraction); lesion load is related to both WM and even more to GM atrophy; lesion load and WM and GM atrophy are significantly related to Expanded Disability Status Scale score and age at onset (suggesting that the younger the age at disease onset, the worse the lesion load and brain atrophy); and GM atrophy is the most significant MRI variable in determining the final disability.

Small interfering RNA-induced TLR3 activation inhibits blood and lymphatic vessel growth.

Neovascularization in response to tissue injury consists of the dual invasion of blood (hemangiogenesis) and lymphatic (lymphangiogenesis) vessels. We reported recently that 21-nt or longer small interfering RNAs (siRNAs) can suppress hemangiogenesis in mouse models of choroidal neovascularization and dermal wound healing independently of RNA interference by directly activating Toll-like receptor 3 (TLR3), a double-stranded RNA immune receptor, on the cell surface of blood endothelial cells. Here, we show that a 21-nt nontargeted siRNA suppresses both hemangiogenesis and lymphangiogenesis in mouse models of neovascularization induced by corneal sutures or hindlimb ischemia as efficiently as a 21-nt siRNA targeting vascular endothelial growth factor-A. In contrast, a 7-nt nontargeted siRNA, which is too short to activate TLR3, does not block hemangiogenesis or lymphangiogenesis in these models. Exposure to 21-nt siRNA, which we demonstrate is not internalized unless cell-permeating moieties are used, triggers phosphorylation of cell surface TLR3 on lymphatic endothelial cells and induces apoptosis. These findings introduce TLR3 activation as a method of jointly suppressing blood and lymphatic neovascularization and simultaneously raise new concerns about the undesirable effects of siRNAs on both circulatory systems.

Correlation between fatigue and brain atrophy and lesion load in multiple sclerosis patients independent of disability.

BACKGROUND Fatigue is a major problem in multiple sclerosis (MS), and its association with MRI features is debated. OBJECTIVE To study the correlation between fatigue and lesion load, white matter (WM), and grey matter (GM), in MS patients independent of disability. METHODS We studied 222 relapsing remitting MS patients with low disability (scores <or=2 at the Kurtzke Expanded Disability Status Scale). Lesion load, WM and GM were measured by fully automated, operator-independent, multi-parametric segmentation method. T1 and T2 lesion volume were also measured by a semi-automated method. Fatigue was assessed by the Fatigue Severity Scale (FSS), and patients divided in high-fatigue (FSS>or=5; n=197) and low-fatigue groups (FSS<or=4; n=25). RESULTS High-fatigue patients showed significantly higher abnormal white matter fraction (AWM-f), T1 and T2 lesion loads, and significant lower WM-f, and GM-f. Multivariate analysis showed that high FSS was significantly associated with lower WM-f, and GM-f. Females and highly educated patients were significantly less fatigued. CONCLUSION These results suggest that among MS patients with low disability those with high-fatigue show higher WM and GM atrophy and higher lesion load, and that female sex and higher levels of education may play a protective role towards fatigue. Furthermore, they suggest that in MS, independent of disability, WM and GM atrophy is a risk factor to have fatigue.

Mild cognitive impairment in drug-naive patients with PD is associated with cerebral hypometabolism

Objective: To characterize brain metabolic changes associated with mild cognitive impairment (MCI) in drug-naive patients with Parkinson disease (PD) using 18F-fluorodeoxyglucose (FDG) and PET (FDG-PET). Methods: This cross-sectional study included newly diagnosed patients with PD with MCI in single or multiple domain (PD-MCI; n =12) and without MCI (PD-nMCI; n =12), and healthy controls (n =12). The groups were matched for age. Moreover, the patient groups were matched for motor disability. All subjects underwent a FDG-PET study. Cerebral regional relative metabolic maps were compared in PD-MCI, PD-nMCI, and controls using regions of interest analysis (ROIs) and voxel-based analysis with statistical parametric mapping. Results: ROIs and voxel-based analyses revealed significant relative hypometabolism in the prefrontal, superior/inferior parietal, and associative occipital cortices as well as in the striatum in patients with PD-MCI relative to controls (p < 0.05) and to a lesser extent in patients with PD-nMCI. In contrast, patients with PD-nMCI did not show significant metabolic changes as compared to controls. Conclusion: MCI in patients with PD is associated with cortical hypometabolism since the earliest stage, independent of therapy or motor disability. The early involvement of posterior cortical region, a pattern shared by advanced stages of PD-MCI and PD with dementia, could represent an early marker of dementia. The relevance of this pattern in predicting prodromal dementia has to be evaluated in longitudinal studies.

Atorvastatin combined to interferon to verify the efficacy (ACTIVE) in relapsing-remitting active multiple sclerosis patients: A longitudinal controlled trial of combination therapy

A large body of evidence suggests that, besides their cholesterol-lowering effect, statins exert anti-inflammatory action. Consequently, statins may have therapeutic potential in immune-mediated disorders such as multiple sclerosis. Our objectives were to determine safety, tolerability and efficacy of low-dose atorvastatin plus high-dose interferon beta-1a in multiple sclerosis patients responding poorly to interferon beta-1a alone. Relapsing—remitting multiple sclerosis patients, aged 18—50 years, with contrast-enhanced lesions or relapses while on therapy with interferon beta-1a 44 µg (three times weekly) for 12 months, were randomized to combination therapy (interferon + atorvastatin 20 mg per day; group A) or interferon alone (group B) for 24 months. Patients underwent blood analysis and clinical assessment with the Expanded Disability Status Scale every 3 months, and brain gadolinium-enhanced magnetic resonance imaging at screening, and 12 and 24 months thereafter. Primary outcome measure was contrast-enhanced lesion number. Secondary outcome measures were number of relapses, EDSS variation and safety laboratory data. Forty-five patients were randomized to group A (n = 21) or B (n = 24). At 24 months, group A had significantly fewer contrast-enhanced lesions versus baseline (p = 0.007) and significantly fewer relapses versus the two pre-randomization years (p < 0.001). At survival analysis, the risk for a 1-point EDSS increase was slightly higher in group B than in group A (p = 0.053). Low-dose atorvastatin may be beneficial, as add-on therapy, in poor responders to high-dose interferon beta-1a alone.

Anxiety is associated with striatal dopamine transporter availability in newly diagnosed untreated Parkinson's disease patients

BACKGROUND Anxiety is a common non-motor symptom among patients with Parkinsons disease (PD). Although the etiology of anxiety in PD is likely to be multifactorial, a dysfunction in the dopaminergic system might be implicated in its pathogenesis. The aim of our study was to investigate a possible dopaminergic mechanism involved in anxiety in newly diagnosed never-medicated PD patients using SPECT and ¹²³I-FP-CIT as the dopamine transporter ligand. METHODS Thirty-four newly diagnosed, untreated PD patients with asymmetric motor symptoms were included in the study: 17 patients with right- and 17 with left-motor onset, matched for age, disease duration and motor disability constituted the group. They were all evaluated for anxiety and depression and underwent an SPECT with ¹²³I-FP-CIT. Dopamine transporter (DAT) availability values for right and left caudate and putamen were calculated and compared between patients with and without anxiety. Regression analyses were also performed in order to correlate DAT availability with the severity of the anxiety symptoms. RESULTS Comparison between PD patients with and those without anxiety revealed significant differences of DAT availability in all the examined regions except the right putamen. In the group of patients considered as a whole, a significant correlation was found between increased anxiety severity and decreased DAT availability in right caudate. CONCLUSIONS We reported an association between nigrostriatal DAT availability deficits and anxiety symptoms in newly diagnosed, untreated PD patients. Our results suggest that hypofunction of the nigrostriatal dopaminergic system may represent one of the functional anomalies involved in anxiety in PD from the earliest stages of disease and irrespective of any therapy.

Eradication of Therapy-resistant Human Prostate Tumors Using an Ultrasound-guided Site-specific Cancer Terminator Virus Delivery Approach

Intratumoral injections of a replication-incompetent adenovirus (Ad) expressing melanoma differentiation-associated gene-7/interleukin-24 (Ad.mda-7), a secreted cytokine displaying cancer-selective, apoptosis-inducing properties, profoundly inhibits prostate cancer (PC) growth in immune-incompetent animals. In contrast, Ad.mda-7 is ineffective in PCs overexpressing antiapoptotic proteins such as Bcl-2 or Bcl-x(L). However, intratumoral injections of a conditionally replication-competent Ad (CRCA) in which expression of the adenoviral E1A gene is driven by the cancer-specific promoter of progression-elevated gene-3 (PEG-3) and which simultaneously expresses mda-7/interleukin (IL)-24 in the E3 region of the Ad (Ad.PEG-E1A-mda-7), a cancer terminator virus (CTV), is highly active in these cells. A major challenge for gene therapy is systemic delivery of nucleic acids directly into an affected tissue. Ultrasound (US) contrast agents (microbubbles-MBs) are viable candidates for gene delivery/therapy. Here, we show that MB/Ad.mda-7 complexes targeted to DU-145 cells using US dramatically reduced tumor burden in xenografted nude mice. Additionally, US-guided MB/CTV delivery completely eradicated not only targeted DU-145/Bcl-x(L)-therapy-resistant tumors, but also nontargeted distant tumors (established in the opposite flank), thereby implementing a cure. These findings highlight potential therapeutic applications of this novel image-guided gene therapy technology for advanced PC patients with metastatic disease.