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Biomedical subjects

D Vassilopoulos

Publications and source records attributed to D Vassilopoulos.

At least 37 records · Page 2Linked to original sources

Safety of antitumour necrosis factor (anti-TNF) therapy in patients with chronic viral infections: hepatitis C, hepatitis B, and HIV infection.

Tumour necrosis factor alpha (TNFalpha) is a pivotal cytokine in host defences with broad ranging effects on the innate and adaptive immune systems. Clinically, TNFalpha inhibitors have demonstrated remarkable efficacy in a wide range of autoimmune and inflammatory disorders but clearly at the cost of heightened susceptibility to a variety of infections in those treated with these agents. Most reports to date have described increased susceptibility to intracellular pathogens in patients with underlying chronic viral infections, but little in the way of adverse event reporting in these patients has occurred. While the reported experience to date is rather limited, TNFalpha inhibitors have displayed a reasonable safety profile in the setting of some chronic viral infections and in certain circumstances have demonstrated adjunctive activity in the treatment of these infections. Given the high prevalence of chronic viral infections in patients who are candidates for anti-TNF therapy and the potential for these agents in the treatment of chronic viral illness, additional studies are urgently needed to assess the risks and benefits of such therapy in these populations.

Antirheumatic Agents↗

Serum levels of soluble intercellular adhesion molecule-1 and soluble endothelial leukocyte adhesion molecule-1 in Alzheimer's disease.

Serum soluble intercellular adhesion molecule-1 (s-ICAM-1) and soluble E-selectin (s-ELAM-1) were evaluated in 25 patients with Alzheimer's disease (AD), 54 patients with noninflammatory neurological diseases (NIND), and 15 control subjects. Patients with AD had a higher s-ICAM-1 level compared with the NIND patients and the control subjects (P< .001 and P< .04, respectively). The presence of high s-ICAM-1 values may be related to immunological processes involved in pathogenetic mechanisms of AD. The not statistically significant values of (s-ELAM-1), a glycoprotein considered an exclusive marker of endothelial activation, compared with the NIND patients and healthy subjects (P< .47 and P< .17, respectively), seem to suggest the neural rather than the endothelial s-ICAM origin in patients with AD.

Adult↗

Working memory deficits in multiple sclerosis: a controlled study with auditory P600 correlates.

BACKGROUND: Recently, the P600 component of event related potentials, a waveform that is conceived to be generated and/or modulated by basal ganglia and cingulate area has been considered an index of the completion of any synchronised operation after target detection, having much in common with working memory operation. Moreover, dysfunction of these brain structures as well as working memory deficits have been implicated in the pathophysiology of multiple sclerosis. The aim of this study was to investigate the patterns of P600 elicited during a working memory test in multiple sclerosis patients compared with healthy controls. METHODS: Twenty two definite, chronic progressive multiple sclerosis patients, with recent exacerbation of their illness, and 20 normal subjects matched for age, sex, and educational level, were studied with a computerised version of the digit span test of Wechsler batteries. Auditory P600 were measured during the anticipatory period of this test. RESULTS: The patient group, as compared with healthy controls, showed significantly reduced latencies of P600 at left frontal areas and reduced P600 amplitudes at left temporoparietal region. Moreover, memory performance of patients was significantly more impaired when compared with healthy controls. CONCLUSIONS: These findings may indicate that multiple sclerosis is associated with abnormal features of the completion of synchronised operation after target detection, as they are reflected by P600 amplitudes and latencies. Dysfunction of this mechanism may contribute to the identification of basic cognitive processes that could account for the cognitive deficits in multiple sclerosis.

Adult↗

A simple and effective approach for detecting maternal cell contamination in molecular prenatal diagnosis.

The presence of maternal cells in fetal samples constitutes a serious potential source for prenatal misdiagnosis. Here we present our approach for detecting maternal cell contamination (MCC) at prenatal diagnosis for eight monogenic disorders (autosomal recessive: beta-thalassaemia, sickle-cell anaemia, cystic fibrosis, prelingual deafness; autosomal dominant: achondroplasia, Huntington disease, myotonic dystrophy, neurofibromatosis type I; X-linked: spinobulbar muscular atrophy). Our aim was to apply a simple and low-cost approach, which would easily and accurately provide information on the fetal tissue MCC status. MCC testing was applied to cases of recessive inheritance where the primary mutation screening of the fetus revealed the presence of the maternal mutation, to cases concerning dominant inheritance and to cases of multiple gestation. The potential presence of maternal cells was determined by the amplification of the 3'-HVR/APO B, D1S80, THO1 and VNTRI of vWf polymorphic loci, which have previously demonstrated high heterozygosity in Caucasians. Among 135 prenatal diagnoses, 44 finally needed to be tested for MCC (32.6%). MCC was detected in four cases, where DNA was isolated directly from chorionic villi samples (CVS), and in one case with DNA isolated directly from amniotic fluid (AF). In almost 90% of cases a simple test of one polymorphic locus provided sufficient information about MCC. The choice of the appropriate locus is therefore essential, while the simultaneous screening of both parents provides the means for distinguishing non-informative sites about MCC.

Adult↗

Thyroid gland neurofibroma in a NF1 patient.

Neurofibromas are a hallmark of neurofibromatosis type 1 (NF1). They are usually benign and rarely present in the thyroid gland region. There is a suspected association between NF1 and intramedullary thyroid carcinoma and there is a well-known association between NF1 and pheochromocytoma. Here, we present a 55-year-old man with typical symptoms of NF1, whose course was complicated by a neurofibroma of the thyroid gland. His clinical spectrum of symptoms included bilateral cataract established before the age of 35 years, quadriparesis and an intrathoracic mass. The patient died because of abdominal carcinomatosis of unknown origin. The rarity of thyroid gland neurofibroma is discussed here, emphasizing the importance of early detection of these and other NF1 complications, also including the risk of malignant transformation with lethal outcome.

Abdominal Neoplasms↗

Episodes of generalized weakness in two sibs with the C164T mutation of the connexin 32 gene.

Two sibs with Charcot-Marie-Tooth disease had repeated episodes of generalized weakness. The patients had distal weakness and atrophy as well as findings of CNS involvement on brain MRI. Both patients bear the C164T mutation of the connexin 32 gene but no mutations of the genes responsible for hyper- or hypokalemic periodic paralysis. It is possible that both patients have one disease with complex phenotype due to abnormal expression of the connexin 32 gene.

Adult↗

Immunopathogenesis of hepatitis B e antigen negative chronic hepatitis B infection.

Hepatitis B e antigen (HBeAg) negative chronic hepatitis B represents currently the predominant form of chronic hepatitis due to the hepatitis B virus (HBV) in several parts of the world. In this review, recent data regarding the process of HBeAg negative HBV strain selection during the course of chronic HBV infection are presented and the potential virus and/or host-mediated mechanisms that lead to chronic liver necroinflammation, i.e. chronic hepatitis are outlined.

Hepatitis B e Antigens↗

Association between presenilin-1 polymorphism and maternal meiosis II errors in Down syndrome.

Several lines of evidence suggest a shared genetic susceptibility to Down syndrome (DS) and Alzheimer disease (AD). Rare forms of autosomal-dominant AD are caused by mutations in the APP and presenilin genes (PS-1 and PS-2). The presenilin proteins have been localized to the nuclear membrane, kinetochores, and centrosomes, suggesting a function in chromosome segregation. A genetic association between a polymorphism in intron 8 of the PS-1 gene and AD has been described in some series, and an increased risk of AD has been reported in mothers of DS probands. We therefore studied 168 probands with free trisomy 21 of known parental and meiotic origin and their parents from a population-based material, by analyzing the intron 8 polymorphism in the PS-1 gene. An increased frequency of allele 1 in mothers with a meiosis II error (70.8%) was found compared with mothers with a meiosis I error (52.7%, P < 0.01), with an excess of the 11 genotype in the meiosis II mothers. The frequency of allele 1 in mothers carrying apolipoprotein E (APOE) epsilon4 allele (68.0%) was higher than in mothers without epsilon4 (52.2%, P < 0.01). We hypothesize that the PS-1 intronic polymorphism might be involved in chromosomal nondisjunction through an influence on the expression level of PS-1 or due to linkage disequilibrium with biologically relevant polymorphisms in or outside the PS-1 gene.

Adult↗

Genotyping of presenilin-1 polymorphism in amyotrophic lateral sclerosis.

The mechanisms underlying motor neuron degeneration in amyotrophic lateral sclerosis are not fully understood. Recent studies suggest that apoptosis is involved in the abnormal neural death that occurs in this devastating disease. Presenilin-1, a transmembrane protein, seems to be implicated in apoptosis. To determine whether presenilin-1 intron 8 polymorphism has an influence in the course of amyotrophic lateral sclerosis, we examined this polymorphism genotypes in a large group of patients (n = 72) with amyotrophic lateral sclerosis and in a random sample of 213 healthy individuals. The results showed a significant difference in genotype (P < 0.04) and allele (P < 0.03) distribution between patients controls. These results suggest a possible intervention of presenilin-1 in the pathogenesis of amyotrophic lateral sclerosis.

Adult↗

Complex management issues: management of HCV in the atypical patient.

Some patients with chronic hepatitis C virus (HCV) infection demonstrate atypical features of presentation and clinical course. These features may be due to direct or indirect effects of the underlying HCV infection or may be part of a separate clinical syndrome. Patients that can be categorized as 'atypical' include immunosuppressed individuals (hypogammaglobulinaemic, co-infected with human immunodeficiency virus, recipients of solid organ or haematopoietic cell transplants, those with associated disease requiring chronic immunosuppressive therapy and patients with chronic renal failure on haemodialysis) as well as patients with various extra-hepatic (HCV-associated mixed cryoglobulinaemia, membranoproliferative glomerulonephritis etc) or autoimmune manifestations. Since many of these patients have been excluded from the large trials evaluating the efficacy of interferon-alpha alone or in combination with ribavirin, data regarding management are limited. In this chapter, the available information regarding the treatment of these patients is reviewed and the frequently encountered therapeutic dilemmas discussed. Finally, some reasonable therapeutic approaches are suggested while the need for controlled studies for these groups of patients is emphasized.

Agammaglobulinemia↗

Three novel mutations in the gap junction beta 1 (GJB1) gene coding region identified in Charcot-Marie-Tooth patients of Greek origin: T55I, R164Q, V120E. Mutation in brief no 236. Online.

Charcot-Marie-Tooth (CMT) disease type CMTX has been linked with mutations in GJB1, a gene on chromosome X coding for a gap junction protein, Connexin 32. We screened the GJB1 gene for mutations by SSCP analysis and sequencing of candidate regions, in five unrelated CMT affected individuals, members of families presenting a mode of transmission and clinical findings compatible with CMTX. Mutations were detected in all five patients. Three not previously reported mutations were identified: C164T, G491A and T359A. Two patients shared the same mutation (C164T) while one had a reported mutation (C43T). Restriction enzyme digestion confirmed the sequencing results, as well as the co-segregation of the mutation with the disease. The same method was used to screen 150 control X chromosomes and the variations were not detected.

Charcot-Marie-Tooth Disease↗

Apolipoprotein E and presenilin-1 genotypes in Huntington's disease.

Huntington's disease (HD) is an autosomal dominant degenerative disease of the central nervous system manifested by involuntary movements (chorea), psychiatric manifestations, and cognitive impairment with a variable age at onset. This variability is mainly attributed to genetic factors. The so-called aging genes [e.g., those for apolipoprotein E (APOE) and presenilin-1 (PS-1) have been implicated in determining the age at onset of Alzheimer's disease, a disease sharing common clinical features with HD. In 60 unrelated patients suffering from HD (mean age at onset 40.1 years, range 20-65) we determined number of CAG repeats and the distribution of the APOE alleles (epsilon2, epsilon3, epsilon4) and PS-1 alleles. The results showed that: (a) The age at onset was higher in the group of patients with the epsilon4 allele (51.6 vs. 38.0 P<0.002), (b) The correlation between the age at onset and the number of CAG repeats was strong in patients with the epsilon3/epsilon3 genotype while it was not detected in patients with epsilon3/epsilon4 genotype. (c) No correlation was found between age at onset and PS-1 alleles. In conclusion, APOE seems to be a significant factor influencing the age at onset of Huntington's disease.

Adult↗

Selected drug complications and treatment conflicts in the presence of coexistent diseases.

The presence of different coexistent systemic diseases often times complicates the selection of the appropriate treatment of an underlying rheumatologic condition. In this article, some controversial treatment conflicts that are frequently encountered in the daily practice of rheumatology are clarified and guidelines for the best available therapeutic options are provided.

Anti-Inflammatory Agents, Non-Steroidal↗

Angelman syndrome with uniparental disomy due to paternal meiosis II nondisjunction.

We report a case of Angelman syndrome (AS) with paternal uniparental disomy (pUPD) of chromosome 15. This 6-year-old girl with overgrowth had frequent, but only provoked laughter, was mildly ataxic with limb hypertonia, and had no intelligible speech. She had deep-set eyes, protruding tongue, and prominent chin. The karyotype was normal. DNA analysis with microsatellites from chromosome 15 showed no inheritance of maternal alleles both within and outside the AS critical region. Proximal markers showed reduction to homozygosity of paternal alleles, intermediate markers showed nonreduction, and distal markers reduction, thus suggesting a meiosis II nondisjunction event in the father with two crossovers. This is, to our knowledge, the first reported case of AS due to meiosis II nondisjunction. We present detailed physical measurements in this patient, adding to the clinical description of the milder phenotype in AS due to pUPD.

Angelman Syndrome↗