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Biomedical subjects

M Ciardi

Publications and source records attributed to M Ciardi.

At least 19 recordsLinked to original sources
PubMed2000

Quantitation of polyomavirus DNA by a competitive nested polymerase chain reaction.

A new method to quantitate small amounts of DNA in clinical specimens is described. The method, a nested competitive polymerase chain reaction (ncPCR), is able to quantitate between 10 and 10(6) copies per tube of polyomavirus DNA and shows good reproducibility when clinical samples are analysed. Throughout the whole procedure, an internal standard (IS) competes for the primers with the target DNA. The internal standard, a heterologous sequence containing the four primer recognition sites, was constructed using a modification of the 'MIMIC' approach that is useful for obtaining competitor sequences for any viral, bacterial or eukaryotic target. The ncPCR method for polyomavirus was applied to cerebrospinal fluids (CSF) from AIDS patients with progressive multifocal leukoencephalopathy (PML) and urine specimens from bone marrow transplant patients affected by haemorrhagic cystitis. The results obtained suggest that the ncPCR method is a sensitive and useful method for quantitating genomic load in clinical samples.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Multiplex polymerase chain reaction for the simultaneous detection and typing of polyomavirus JC, BK and SV40 DNA in clinical samples.

A novel multiplex nested PCR (nPCR) method was developed for detecting and differentiating simultaneously the DNA of polyomaviruses JC, BK and SV40 in a single tube. In the first amplification step the same set of primers were used to amplify a conserved DNA region of the large T antigen gene of JCV, BKV and SV40. The second round of multiplex nPCR was carried out using a set of primers designed to render products of different size for each related virus. The thermocycling parameters and concentration of each reaction component were optimised systematically to achieve optimal specificity and sensitivity for the nPCR assay. The sensitivity of the method ranged between one and 10 copies of polyomavirus genome. Cerebrospinal fluid (CSF) was examined from AIDS patients with clinical and neuroradiological evidence of progressive multifocal leukoencephalopathy (PML) and CSF from AIDS patients with other neurological alterations. Urine specimens from bone marrow transplant recipients affected by haemorrhagic cystitis were also tested. The results obtained suggest that the assay is a good tool for supporting the diagnosis of polyomavirus infection and could be used for epidemiological purposes and in other studies in order to define better the role of polyomaviruses in human disease.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Multicenter evaluation of the Amplicor Enterovirus PCR test with cerebrospinal fluid from patients with aseptic meningitis. The European Union Concerted Action on Viral Meningitis and Encephalitis.

The Amplicor Enterovirus PCR test was compared with viral culture for the detection of enteroviruses in cerebrospinal fluid (CSF) specimens. In a multicenter study in which nine laboratories participated, a total of 476 CSF specimens were collected from patients with suspected aseptic meningitis. Sixty-eight samples were positive by PCR (14.4%), whereas 49 samples were positive by culture (10.4%), demonstrating that the Amplicor Enterovirus PCR test was significantly more sensitive than culture (P < 0.001). After discrepancy analysis the sensitivity and specificity of the Amplicor Enterovirus PCR test obtained by using viral culture as the "gold standard" were 85.7 and 93.9%, respectively. Our results with the CSF specimens collected in different countries demonstrate that the Amplicor test is capable of detecting a large variety of enterovirus serotypes and epidemiologically unrelated isolates in CSF specimens from patients with aseptic meningitis. The Amplicor Enterovirus PCR test is a rapid assay which can be routinely performed with CSF samples and is an important improvement for the rapid diagnosis of enteroviral meningitis.

Cerebrospinal Fluid↗
PubMed1997

The detection of intrathecal synthesis of anti-herpes simplex IgG antibodies: comparison between an antigen-mediated immunoblotting technique and antibody index calculations. European Union Concerted Action on Virus Meningitis and Encephalitis.

The detection of intrathecal antibody synthesis was compared by the calculation of antibody indices (AI) derived from ELISA techniques with the detection of virus-specific oligoclonal IgGs by an antigen-mediated capillary blot technique. Twenty-seven paired serum and cerebrospinal fluid (CSF) samples were examined from 15 immunocompetent patients with herpes simplex virus encephalitis (HSE) diagnosed by PCR on early CSF samples. These techniques were also applied to paired samples from 20 multiple sclerosis (MS) patients, 10 patients with other inflammatory neurological diseases and 10 patients with non inflammatory neurological disorders. There was a good correlation between the results obtained by AI and those obtained by immunoblotting, especially in HSE (2 discordant results out of 27). Discrepancies were more frequent (25%) in MS patients where a "polyspecific" reaction characterized by low affinity antibodies is known to occur. Some of the discrepancies could, in part, be due to serological cross-reaction with varicella zoster virus.

Adolescent↗
PubMed1997

Polymerase chain reaction for detection of JC virus DNA in cerebrospinal fluid: a quality control study. European Union Concerted Action on Viral Meningitis and Encephalitis.

The sensitivity and specificity of PCR of CSF for the diagnosis of progressive multifocal leuko encephalopathy is estimated at 75 and 98.5%, respectively. However, inter-laboratory and inter-technique variations have been shown to produce wide variations. A 10-fold dilution series of JC virus in cerebrospinal fluid was prepared and circulated for 'blind' evaluation in laboratories participating in a European Union Concerted Action on Virus Meningitis and Encephalitis. Six of seven laboratories returned results with sensitivity of between 10 and 1 JCV DNA copy equivalents per 10 microl of CSF, one laboratory detected 10(5) copies per 10 microl of CSF. These results demonstrate the feasibility of using virus diluted in CSF for comparison of PCR techniques, and that the range of sensitivity of JCV PCR in proficient laboratories is between 10 and 1 copy equivalents per 10 microl of CSF.

Aged↗
PubMed1997

Specific diagnostic methods for herpesvirus infections of the central nervous system: a consensus review by the European Union Concerted Action on Virus Meningitis and Encephalitis.

BACKGROUND: Herpesvirus infections of the central nervous system are often severe but are fortunately rare. The incidence of these infections has however, increased in recent years as a consequence of an increase in the number of immune-compromised individuals. New diagnostic procedures have improved our ability to diagnose these infections and herpesviruses may yet be implicated as the cause of further neurological diseases with no known aetiology. Methodological standards for selection and evaluation of patient materials are essential to the provision of reliable diagnosis, yet few studies have addressed this important issue. OBJECTIVES: To describe and define methodological standards and reference methodology for diagnosis of herpesvirus infections of the CNS. STUDY DESIGN: Information gathered by literature review. RESULTS: Only for herpes simplex encephalitis is there sufficient data to allow the definition of reference methodology. Good methodological standards exist but few studies have adhered to these standards. As methods for the detection of specific intrathecal antibody synthesis are well established yet under-used in diagnostic virology, the principle of these measurements is reviewed in some detail. CONCLUSIONS: Herpesvirus infections of the CNS are of increasing importance. High quality, multi-centre studies are needed to establish the value of the new diagnostic test procedures if further improvement in the diagnostic sensitivity and specificity of these procedures is to be achieved.

Brain↗
PubMed1994

High cerebrospinal fluid and serum levels of tumor necrosis factor-alpha in asymptomatic HIV-1 seropositive individuals. Correlation with interleukin-2 and soluble IL-2 receptor.

The relationship between tumour necrosis factor-alpha (TNF-alpha) and the interleukin-2 (ILL-2) system in HIV-1 infection is important in understanding the dynamics of early immune response before the development of acquired immunodeficiency syndrome. Levels of TNF-alpha, IL-2 and soluble IL-2 receptor (sIL-2R) in serum and cerebrospinal fluid (CSF) samples from 31 asymptomatic HIV-1 seropositive individuals were measured. High levels of TNF-alpha were detected in CSF of 17 (55%) and serum of 22 (71%) subjects, 15 (88%) of whom had elevated CSF IL-2 levels and 16 (94%) had high sIL-2R levels. Moreover, CSF levels of TNF-alpha significantly correlated with CSF levels of IL-2 and sIL-2R. TNF-alpha, IL-2 and sIL-2R seem to be released within the intrathecal compartment early in the course of HIV-1 infection. In view of the known cytotoxic effects of TNF-alpha, an early release may contribute to subsequent development of neurological complications.

Cerebrospinal Fluid Proteins↗
PubMed1994

Cytomegalovirus encephalitis in two patients with AIDS receiving ganciclovir for cytomegalovirus retinitis.

Cytomegalovirus (CMV) encephalitis has been reported with increasing frequency in patients with AIDS. Nevertheless, the management of CMV-related encephalitis appears to be problematic and data in the literature on the clinical efficacy of ganciclovir therapy is sparse and controversial. We describe two patients with AIDS who developed CMV encephalitis while receiving ganciclovir maintenance therapy for CMV retinitis. Moreover, there was no improvement in neurological status or virological and radiological response during a further induction course of ganciclovir. These observations suggest that the currently recommended therapeutic protocols with ganciclovir are not effective in the prevention and treatment of CMV encephalitis in patients with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1994

An unusual neurological feature of HIV-1 encephalopathy: Gerstmann's syndrome.

The authors describe the first case in literature of Gerstmann's syndrome (agraphia, acalculia, finger agnosia) occurred in HIV correlated encephalopathy developed as the first severe manifestation of HIV infection in a patient with prevalent white matter neuroradiologic alterations. The PDL rapidly extended from the left subcortical parietal-occipital regions to the pre-rolandic one, with subsequent involvement of the corpus calosum splenium and the bilateral temporal lobes white matter. The authors indicate the extent of the lesions and the involvement of the interhemispheric connection fibres as the pathogenetic mechanism of the "Gerstmann syndrome", that until today has not been reported in the literature of the wide variety of AIDS dementia complex. The administration of 1 g of zidovudine for about 9 months did not avoid the establishing of the neurologic damage, but the sudden suspension of the drug could have enhanced the exacerbation of inflammation and the involvement of areas whose lesion is classically believed responsible for cognitive impairment.

AIDS Dementia Complex↗
PubMed1993

In vivo relationship of interleukin-2 and soluble IL-2 receptor to blood-brain barrier impairment in patients with active multiple sclerosis.

Interleukin (IL)-2 has well-recognized effects on cerebral endothelial cells and, therefore, may mediate disruption of the blood-brain barrier in patients with multiple sclerosis (MS). To evaluate the in vivo relationship of the IL-2 system to blood-brain barrier impairment in MS, levels of IL-2 and soluble IL-2 receptors (sIL-2R) in cerebrospinal fluid (CSF) and serum samples from 50 patients with active MS and 49 controls were correlated with values of the CSF to serum albumin ratio. Intrathecal levels of IL-2 and sIL-2R were significantly higher in MS compared with the control groups and correlated with albumin ratios in MS patients. Intrathecal levels of IL-2 and sIL-2R also correlated with the degree of barrier damage in these patients. It is suggested that intrathecal levels of IL-2 and sIL-2R are related to barrier impairment in MS and may be important in understanding some of the pathological changes of this condition.

Adult↗
PubMed1993

Intrathecal synthesis of interleukin-2 and soluble IL-2 receptor in asymptomatic HIV-1 seropositive individuals. Correlation with local production of specific IgM and IgG antibodies.

The relationship between the interleukin-2 (IL-2) system and the humoral response against human immunodeficiency virus type-I (HIV-1) is important in understanding the immune reaction before the development of AIDS. Levels of IL-2 and soluble IL-2 receptor (sIL-2R) in serum and cerebrospinal fluid (CSF) samples from 31 asymptomatic HIV-1 seropositive individuals were measured and correlated with levels of anti-1 IgG and IgM antibodies. High IL-2 levels were detected in the CSF of 20 (65%) subjects, 18 (90%) of whom had evidence of intrathecal synthesis of HIV-1-specific IgM antibodies. Similarly, IgG antibodies were detected in 10 subjects who had elevated IL-2 levels in the CSF. Moreover, intrathecal levels of IL-2 and sIL-2R correlated with intrathecal synthesis of both IgG and IgM antibodies. Local release of IL-2 seems to play an important role in the initiation of the antibody response against HIV-1 in early stages of infection and may be utilised in devising effective therapeutic strategies.

Adolescent↗
PubMed1993

Increased levels of circulating ICAM-1 in serum and cerebrospinal fluid of patients with active multiple sclerosis. Correlation with TNF-alpha and blood-brain barrier damage.

The mechanism for the initiation of blood-brain barrier damage and intrathecal inflammation in multiple sclerosis (MS) is poorly understood. We have recently reported that levels of tumor necrosis factor-alpha (TNF-alpha) correlate with blood-brain barrier damage in patients with active MS. Stimulation of endothelial cells by TNF-alpha induces the expression of intercellular adhesion molecule-1 (ICAM-1), which is an important early marker of immune activation and response. We report herein for the first time the detection of high levels of free circulating ICAM-1 in serum and cerebrospinal fluid of patients with active MS. Levels of circulating ICAM-1 in these patients correlated with CSF pleocytosis, TNF-alpha levels and blood-brain barrier damage. These findings have important implications for the understanding and investigation of the intrathecal inflammatory response in active MS.

Adult↗
PubMed1992

Blood-brain barrier damage in patients with bacterial meningitis: association with tumor necrosis factor-alpha but not interleukin-1 beta.

Brain damage after meningeal infection could result from impairment of cerebral endothelial cell functions and disruption of blood-brain barriers. Tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta (IL-1 beta) produce many of their effects by acting on endothelial cells. This study correlates levels of TNF alpha and IL-1 beta in paired cerebrospinal fluid (CSF) and serum samples with the degree of blood-brain barrier damage, as manifested by CSF to serum albumin quotient, in 48 patients with bacterial meningitis and 66 controls. CSF levels of TNF alpha and IL-1 beta in bacterial meningitis were significantly higher than in controls. Intrathecal levels of TNF alpha, but not IL-1 beta, correlated with albumin quotient (P less than .001), with degree of blood-brain barrier disruption (P less than .001), and with disease severity and indices of meningeal inflammation. Sequential CSF samples demonstrated that IL-1 beta and TNF alpha disappear from the CSF within 24 h of antibiotic treatment. Data presented here suggest that TNF alpha is related to blood-brain barrier damage in bacterial meningitis and that its effect could be dissociated from that of IL-1 beta.

Adolescent↗
PubMed1991

Intrathecal immune response in patients with the post-polio syndrome.

BACKGROUND: The syndrome of progressive muscular atrophy decades after acute paralytic poliomyelitis (post-polio syndrome) is not well understood. The theory that physiologic changes and aging cause the new weakness does not explain the immunologic abnormalities reported in some patients. An alternative explanation is persistent or recurrent poliovirus infection. METHODS: We assessed the intrathecal antibody response to poliovirus and intrathecal production of interleukin-2 and soluble interleukin-2 receptors in 36 patients with the post-polio syndrome and 67 controls (including 13 who had had poliomyelitis but had no new symptoms and 18 with amyotrophic lateral sclerosis). Intrathecal antibody responses to measles, mumps, herpes simplex, and varicella zoster viruses were also determined. RESULTS: Oligoclonal IgM bands specific to poliovirus were detected in the cerebrospinal fluid of 21 of the 36 patients with the post-polio syndrome (58 percent) but in none of the control group (P less than 0.0001). In quantitative studies there was evidence of increased intrathecal synthesis of IgM antibodies to poliovirus only among the patients with the post-polio syndrome; there was no increased synthesis of IgM to measles, mumps, herpes simplex, or varicella zoster viruses. The patients with post-polio syndrome had significantly higher mean (+/- SD) (cerebrospinal fluid levels of interleukin-2 and soluble interleukin-2 receptors than the controls (8.1 +/- 5.3 vs. 1.4 +/- 0.8 U per milliliter and 159.6 +/- 102.9 vs. 10.7 +/- 6.2 U per milliliter, respectively). The intrathecal synthesis of IgM antibodies to poliovirus correlated with the cerebrospinal fluid concentrations of interleukin-2 (P less than 0.0005) and soluble interleukin-2 receptors (P less than 0.001). CONCLUSIONS: An intrathecal immune response against poliovirus is present in many patients with the post-polio syndrome. In some of these patients the recrudescence of muscle weakness may be caused by persistent or recurrent infection of neural cells with the poliovirus.

Adult↗
PubMed1991

Serum selenium concentration and disease progress in patients with HIV infection.

The selenium concentration in the serum of 67 patients with HIV infection was measured to determine whether selenium deficiency occurred in the different stages of the disease. In the first stage of the study, patients were divided into four groups: symptom-free subjects, PGL (persistent generalized lymphadenopathy), ARC (AIDS related complex), and AIDS (acquired immunodeficiency syndrome). Selenium concentrations were normal in HIV antibody positive symptom-free subjects (1.18 +/- 0.27 mumol/L) and lower than normal in the other three groups (p less than 0.001). There was a significant correlation (p less than 0.001) between selenium levels and values of hemoglobin and erythrocyte sedimentation rate. Selenium deficiency was in no case associated with a lack of zinc in serum (also determined in all patients). In the second stage of the study, 12 patients were treated for a period of two months with low doses of selenium to assess whether such supplementation was able to restore their impaired immunological and hematological functions. The therapy increased serum selenium concentrations (from 0.77 +/- 0.23 to 1.44 +/- 0.41 mumol/L) and symptomatic improvements were noted. However, no changes were observed in the immunological and hematological parameters.

Adult↗