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Biomedical subjects

G Giovannoni

Publications and source records attributed to G Giovannoni.

At least 19 recordsLinked to original sources
PubMed2003

Serum and urine nitrate and nitrite are not reliable indicators of intrathecal nitric oxide production in acute brain injury.

This study examined the correlation between nitric oxide (NO) metabolites in the three major body fluid compartments and assessed performance of newly described vanadium-based assay for simultaneous detection of nitrite and nitrate (NO(x)) in human samples. Vanadium reduces nitrate to nitrite, which can be measured after a colorimetric reaction with Griess reagents. Cisternal cerebro spinal fluid (CSF), serum and urine samples from 10 patients with acute brain injury (ABI) were compared to control subjects. Significantly higher CSF NO(x) levels were found in brain injury patients compared to control patients (19.7+/-13.7 vs. 6.5+/-2.3 microM; p=0.01), which persisted for 10-day period of observation. The serum and urine levels of NO(x) on admission were not statistically different (42.8+/-28.2 microM; 584.1+/-337.8 micromol/g Cr, respectively) from controls (36.8+/-14.8 microM; 819.7+/-356.0 micromol/g Cr), but tended to decrease during the disease course reaching the lowest level on day 6 (serum: 19.3+/-8.4 microM, urine: 300.4+/-111.9 micromol/g Cr). CSF levels of NO(x) correlated moderately with those in serum (p=0.001, R=0.5). Serum NO(x) concentrations correlated weakly with urine levels (p=0.04, R=0.3). There was no significant correlation between CSF NO(x) and urine NO(x) levels. In conclusion, patients suffering brain injury had increased NO(x) concentrations in CSF, which remained independent from other body fluid compartments. Serum and urinary NO(x) levels cannot be used as a reliable index to assess intrathecal NO production.

Adult↗
PubMed2003

Multiple sclerosis: Neurofilament light chain antibodies are correlated to cerebral atrophy.

OBJECTIVE: To evaluate markers of axonal damage in CSF and serum of patients with different subtypes of MS in relation to measures of disease progression on MRI. METHODS: In 51 patients with MS (21 relapsing-remitting, 20 secondary progressive, 10 primary progressive), levels of heavy and light neurofilaments (NfH and NfL) and antibodies to neurofilaments (anti-NfL and -NfH) as well as the total immunoglobulin G (IgG) were analyzed. MRI analysis included T2 hyperintense, T1 hypointense, and gadolinium enhancing lesions and markers of cerebral atrophy (ventricular and parenchymal fractions). RESULTS: For the total group, correlations were found between the anti-NfL index and the parenchymal fraction (PF) (r = -0.51, p < 0.001), T2 lesion load (r = 0.41, p < 0.05), ventricular fraction (r = 0.37, p < 0.05), and T1 lesion load (r = 0.37, p < 0.05). For the anti-NfH index, a correlation was found with the PF (r = -0.39, p < 0.05). No correlations were found between the IgG index and MRI measures. CONCLUSIONS: Intrathecal production of anti-NfL antibodies may serve as a marker of tissue damage, particularly axonal loss, in MS.

Adult↗
PubMed2003

A specific ELISA for measuring neurofilament heavy chain phosphoforms.

Neurofilaments (Nf) are the major constitutents of the axoskeleton and body fluid Nf levels are an important tool for estimating axonal degeneration in vivo. This paper presents a new sandwich ELISA allowing quantification of the NfH(SMI35) phosphoform from CSF, brain tissue and cell culture homogenates. The sensitivity of the NfH(SMI35) ELISA is 0.2 ng/ml with a recovery of 119% and a mean within- and between-batch precision of 10.6% and 23%, respectively. CSF NfH(SMI35) was stable at 4 degrees C, is not influenced by freeze-thaw cycles, and proteolysis present at room temperature could be prevented by adding protease inhibitors. Aggregate formation was observed for HPLC-purified bovine NfH and could be resolved by sonication. The upper reference value for CSF NfH(SMI35) levels (0.73 ng/ml) was defined as the 95% cumulative frequency from 416 CSF samples. Based on this cutoff, a significantly higher proportion of patients with amyotrophic lateral sclerosis, space-occupying lesions, disc prolapse and subarachnoid haemorrhage had pathologically elevated NfH(SMI35) levels compared to patients with cluster headache or demyelinating disease.A new nomenclature is proposed to facilitate the comparison between ELISA, immunoblotting and immunocytochemistry.

Animals↗
PubMed2003

Quantification of neurodegeneration by measurement of brain-specific proteins.

Quantification of neurodegeneration in animal models is typically assessed by time-consuming and observer-dependent immunocytochemistry. This study aimed to investigate if newly developed ELISA techniques could provide an observer-independent, cost-effective and time-saving tool for this purpose. Neurofilament heavy chain (NfH(SM135)), astrocytic glial fibrillary acidic protein (GFAP), S100B and ferritin, markers of axonal loss, gliosis, astrocyte activation and microglial activation, respectively, were quantified in the spinal cord homogenates of mice with chronic relapsing experimental allergic encephalomyelitis (CREAE, n=8) and controls (n=7). Levels of GFAP were found to be threefold elevated in CREAE (13 ng/mg protein) when compared to control animals (4.5 ng/mg protein, p<0.001). The inverse was observed for NfH(SM135) (21 ng/mg protein vs. 63 ng/mg protein, p<0.001), ferritin (542 ng/mg protein vs. 858 ng/mg protein, p<0.001) and S100B (786 ng/mg protein vs. 2080 ng/mg protein, N.S.). These findings were confirmed by immunocytochemistry, which demonstrated intense staining for GFAP and decreased staining for NfH(SM135) in CREAE compared to control animals. These findings indicate that axonal loss and gliosis can be estimated biochemically using the newly developed ELISA assays for NfH(SM135) and GFAP. These assays may facilitate the quantification of pathological features involved in neurodegeneration.

Animals↗
PubMed2003

Tourette's syndrome: a cross sectional study to examine the PANDAS hypothesis.

BACKGROUND: The classical neurological disorder after group A beta haemolytic streptococcal infection is Sydenham's chorea. Recently a tic disorder occurring after group A streptococcal infection has been described and termed PANDAS (paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection). It is proposed that antibodies induced after group A streptococcal infection react with basal ganglia neurones in Sydenham's chorea and PANDAS. Anti-basal ganglia antibodies (ABGA) are present in most cases of acute Sydenham's chorea, but rarely in controls. OBJECTIVE: To investigate the hypothesis that Tourette's syndrome may be associated with group A streptococcal infection and ABGA. METHODS: 100 patients with Tourette's syndrome (DSM-IV-TR) were enrolled in a cross sectional study. Children with neurological disease (n = 50) and recent uncomplicated streptococcal infection (n = 40), adults with neurological disease (n = 50), and healthy adults (n = 50) were studied as controls. Recent group A streptococcal infection was defined using antistreptolysin O titre (ASOT). ABGA were detected using western immunoblotting and indirect immunofluorescence. RESULTS: ASOT was raised in 64% of children with Tourette's syndrome compared with 15% of paediatric neurological disease controls (p < 0.0001), and in 68% of adults with Tourette's syndrome compared with 12% of adult neurological controls and 8% of adult healthy controls (p < 0.05). Western immunoblotting showed positive binding in 20% of children and 27% of adults with Tourette's syndrome, compared with 2-4% of control groups (p < 0.05). The most common basal ganglia binding was to a 60 kDa antigen, similar to the proposed antigen in Sydenham's chorea. Indirect immunofluorescence revealed autoantibody binding to basal ganglia neurones. Serological evidence of recent group A streptococcal infection, assessed by a raised ASOT, was detected in 91% (21/23) of Tourette's syndrome patients with positive ABGA compared with 57% (44/77) with negative ABGA (p < 0.01). CONCLUSIONS: The results support a role of group A streptococcal infection and basal ganglia autoimmunity in a subgroup of patients with Tourette's syndrome and suggest a pathogenic similarity between Sydenham's chorea and some patients with Tourette's syndrome.

Adolescent↗
PubMed2003

Interferon beta in multiple sclerosis: experience in a British specialist multiple sclerosis centre.

BACKGROUND: The efficacy of interferon beta (IFN beta) is well established in relapsing-remitting multiple sclerosis (MS). However, the use of this drug in clinical practice is complex, especially because it is only partially effective, its long term efficacy and side effects are unknown, its efficacy may be abrogated by the development of neutralising antibodies, compliance is variable, and its cost effectiveness is controversial. OBJECTIVES AND METHODS: Analysis of a prospectively followed up series of 101 MS patients treated with IFN beta was undertaken to: (1) monitor the outcome of IFN beta treatment in clinical practice; (2) compare the immunogenicity of the three commercial IFN beta preparations available; (3) assess the proportion of patients fulfilling the current guidelines of the Association of British Neurologists for stopping IFN beta therapy. RESULTS: During a median treatment period of 26 months (range 2-85), the relapse rate decreased by 41%. Although the reduction in the relapse rate was similar for all three commercial products, none of the Avonex treated patients were relapse free, compared with 19% of the Betaferon treated and 27% of the Rebif treated patients (p=0.02). Neutralising antibodies were not detected in Avonex treated patients (0 of 18), compared with 12 of 32 (38%) Betaferon treated and 10 of 23 (44%) Rebif treated patients (p=0.02). Forty of 101 (40%) patients satisfied the current (2001) Association of British Neurologists criteria for stopping IFN beta treatment at some stage during their treatment. CONCLUSION: IFN beta is effective in reducing the relapse rate in patients with relapsing-remitting MS in routine clinical practice. However, after a median treatment duration of 26 months, 40% of initially relapsing-remitting MS patients seem to have ongoing disease activity, presenting as disabling relapses or insidious progression.

Adjuvants, Immunologic↗
PubMed2002

Anti-basal ganglia antibodies in acute and persistent Sydenham's chorea.

OBJECTIVE: To determine the sensitivity and specificity of methods to detect anti-basal ganglia antibodies (ABGA) in Sydenham's chorea (SC). BACKGROUND: SC is a delayed manifestation of group Abeta hemolytic streptococcal infection typically associated with rheumatic fever (RHF). SC is characterized by chorea and motor and neuropsychiatric symptoms. Patients with SC produce antibodies that cross-react with streptococcal, caudate, and subthalamic nuclei antigens detected using an immunofluorescent (IF) method with inconsistent reports of positivity. METHODS: The authors developed ELISA and Western immunoblotting (WB) methods to detect ABGA and compared these assays to IF. They investigated samples from patients with acute SC (n = 20), persistent SC (n = 16), control samples from RHF (n = 16), and healthy pediatric volunteers (n = 11). RESULTS: ABGA ELISA had a sensitivity of 95% and specificity of 93% in acute SC. Both WB and IF had a sensitivity of 100% and specificity of 93%. In the persistent SC group, ABGA sensitivity dropped to 69% using WB and to 63% using IF. Three common basal ganglia antigens were identified by WB in both acute and persistent SC (40 kDa [n = 15], 45 kDa [n = 15], and 60 kDa [n = 13]). There was no antibody reactivity to cerebellum, cerebral cortex, or myelin antigen preparations in any group. CONCLUSIONS: These results support the hypothesis that Syndenham's chorea is an autoantibody-mediated disorder. Western immunoblotting and immunofluorescence are the best methods for detecting anti-basal ganglia antibodies, and reactivity to basal ganglia antigens of 40, 45, and 60 kDa were commonly seen in both acute and persistent cases of SC.

Acute Disease↗
PubMed2002

Cerebrospinal fluid levels of nitric oxide metabolites predict response to methylprednisolone treatment in multiple sclerosis and optic neuritis.

The role of nitric oxide (NO) in multiple sclerosis (MS) is not clear. We found increased cerebrospinal fluid concentrations of the NO degradation products nitrate (NO(x)) in clinically definite MS but not in clinically isolated syndromes. High CSF concentrations of NO(x) correlated with long attack duration. Patients carrying the truncated CC chemokine receptor allele CCR5 Delta32 had lower serum concentration of NO(x) at later attack stages. NO(x) concentrations did not change after methylprednisolone treatment but high concentrations were associated with more pronounced treatment responses. These findings suggest an association of high CSF levels of NO(x) with more severe disease activity in relapsing-remitting MS.

Adult↗
PubMed2002

Markers for different glial cell responses in multiple sclerosis: clinical and pathological correlations.

Disease progression in multiple sclerosis occurs within the interface of glial activation and gliosis. This study aimed to investigate the relationship between biomarkers of different glial cell responses: (i) to disease dynamics and the clinical subtypes of multiple sclerosis; (ii) to disability; and (iii) to cross-validate these findings in a post-mortem study. To address the first goal, 51 patients with multiple sclerosis [20 relapsing remitting (RR), 21 secondary progressive (SP) and 10 primary progressive (PP)] and 51 neurological control patients were included. Disability was assessed using the ambulation index (AI), the Expanded Disability Status Scale score (EDSS) and the 9-hole PEG test (9HPT). Patients underwent lumbar puncture within 7 days of clinical assessment. Post-mortem brain tissue (12 multiple sclerosis and eight control patients) was classified histologically and adjacent sites were homogenized for protein analysis. S100B, ferritin and glial-fibrillary acidic protein (GFAP) were quantified in CSF and brain-tissue homogenate by ELISA (enzyme-linked immunosorbent assay) techniques developed in-house. There was a significant trend for increasing S100B levels from PP to SP to RR multiple sclerosis (P < 0.05). S100B was significantly higher in RR multiple sclerosis than in control patients (P < 0.01), whilst ferritin levels were significantly higher in SP multiple sclerosis than in control patients (P < 0.01). The S100B : ferritin ratio discriminated patients with RR multiple sclerosis from SP, PP or control patients (P < 0.05, P < 0.01 and P < 0.01, respectively). Multiple sclerosis patients with poor ambulation (AI > or =7) or severe disability (EDSS >6.5) had significantly higher CSF GFAP levels than less disabled multiple sclerosis or control patients (P < 0.01 and P < 0.001, respectively). There was a correlation between GFAP levels and ambulation in SP multiple sclerosis (r = 0.57, P < 0.01), and between S100B level and the 9HPT in PP multiple sclerosis patients (r = -0.85, P < 0.01). The post-mortem study showed significantly higher S100B levels in the acute than in the subacute plaques (P < 0.01), whilst ferritin levels were elevated in all multiple sclerosis lesion stages. Both GFAP and S100B levels were significantly higher in the cortex of multiple sclerosis than in control brain homogenate (P < 0.001 and P < 0.05, respectively). We found that S100B is a good marker for the relapsing phase of the disease (confirmed by post-mortem observation) as opposed to ferritin, which is elevated throughout the entire course. GFAP correlated with disability scales and may therefore be a marker for irreversible damage. The results of this study have broad implications for finding new and sensitive outcome measures for treatment trials that aim to delay the development of disability. They may also be considered in future classifications of multiple sclerosis patients.

Adult↗
PubMed2001

Fatigue is not associated with raised inflammatory markers in multiple sclerosis.

BACKGROUND: The pathogenesis of fatigue in patients with MS is poorly understood. OBJECTIVE: To test the hypothesis that fatigue in MS is related to inflammatory disease activity as measured by systemic markers of inflammation. METHODS: Fatigue as assessed by the Fatigue Questionnaire Scale (FQS) and Krupp's Fatigue Severity Scale (KFSS) was correlated with several inflammatory markers in 38 patients with MS (16 relapsing-remitting [RR; 7 of whom had benign MS), 9 secondary progressive [SP], 13 primary progressive [PP]). The markers included daily urinary neopterin excretion, a marker of interferon-gamma-activated macrophage activity, and serum C-reactive protein (CRP) and soluble intercellular adhesion molecule-1 (sICAM-1) levels. Urinary neopterin excretion was measured daily for 2 weeks. RESULTS: No correlation was found between urinary neopterin excretion, CRP, or sICAM-1 and the fatigue scores. However, patients with a raised serum CRP level had higher KFSS, but not FQS, scores than patients with normal CRP levels (KFSS, 50 +/- 8 vs 41 +/- 14, p = 0.05; FQS, 13 +/- 4 vs 11 +/- 5, p = NS). When assessed using the FQS, patients with RR and SP MS were more fatigued than patients with PP MS (RR = 12.5 [4 to 23] vs SP = 13 [8 to 18] vs PP = 9 [7 to 14], p = 0.02). The patients with benign MS were as fatigued as patients with nonbenign disease. CONCLUSION: The pathogenesis of fatigue in MS is complex and does not appear to be directly related to systemic markers of inflammatory disease activity. Interestingly, patients with PP MS were less fatigued than patients with RR disease.

Adult↗
PubMed2001

Haptoglobins as markers of blood-CSF barrier dysfunction: the findings in normal CSF.

Cerebrospinal fluid from 39 healthy individuals showed evidence for increasing blood-CSF barrier permeability with age, and confirmed that haptoglobins are more sensitive but less predictive markers of barrier permeability than total protein. Haptoglobin (Hp) species were identified by polyacrylamide gel electrophoresis followed by immunoblotting. Hp 1-1 (35 A, 85 kDa) was detected in all (9/9) subjects who exhibited this phenotype. Hp 2-1 (42 A, 120 kDa) was detected in 53% (8/15) of subjects in whom Hp 2-1 was the phenotype. Hp 2-2 (54 A, 160 kDa) was detected in only 20% (3/15) of subjects who exhibited this phenotype. The likelihood of detecting any haptoglobin species corresponded to the molecular size and the consequent resistance offered by the barrier. Among younger subjects aged < or =45 years, a significant difference in incidence occurred between the two smaller species Hp 1-1 and Hp 2-1. However, among those aged >45, the significant difference in incidence was between the two larger species Hp 2-1 and Hp 2-2. The incidence of detection among those with Hp 2-1 phenotypes was higher in the older age group. The increased likelihood of detecting haptoglobins with age is in keeping with the notion that barrier function is compromised by age, and also indicates that Hp 2-1 and Hp 2-2 are sensitive markers of barrier function. The appreciable incidence of haptoglobins in normal CSF, even of the larger species, suggests reservation in assuming that their presence signifies barrier damage.

Adolescent↗
PubMed2001

Poststreptococcal acute disseminated encephalomyelitis with basal ganglia involvement and auto-reactive antibasal ganglia antibodies.

Antibasal ganglia antibodies (ABGA) are associated with Sydenham's chorea and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. We present 10 patients with acute disseminated encephalomyelitis (ADEM) associated with Group A beta hemolytic streptococcal infection. The clinical phenotype was novel, with 50% having a dystonic extrapyramidal movement disorder, and 70% a behavioral syndrome. None of the patients had rheumatic fever or Sydenham's chorea. Enzyme-linked immunosorbent assay, Western immunoblotting, and immunohistochemistry were used to detect ABGA. Neurological (n = 40) and streptococcal (n = 40) controls were used for comparison. Enzyme-linked immunosorbent assay results showed significantly elevated ABGA in the patients with poststreptococcal ADEM. Western immunoblotting demonstrated ABGA reactivity to three dominant protein bands of 60, 67, or 80 kDa; a finding not reproduced in controls. Fluorescent immunohistochemistry demonstrated specific binding to large striatal neurones, which was not seen in controls. Streptococcal serology was also significantly elevated in the poststreptococcal ADEM group compared with neurological controls. Magnetic resonance imaging studies showed hyperintense basal ganglia in 80% of patients with poststreptococcal ADEM, compared to 18% of patients with nonstreptococcal ADEM. These findings support a new subgroup of postinfectious autoimmune inflammatory disorders associated with Group A beta hemolytic streptococcus, abnormal basal ganglia imaging, and elevated ABGA.

Acute Disease↗