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Biomedical subjects

C Nicolaou

Publications and source records attributed to C Nicolaou.

8 recordsLinked to original sources

An unusual case of insomnia associated with Whipple encephalopathy: first case reported from Greece.

Whipple disease is a relapsing systemic illness caused by Tropheryma whippelii. Central nervous system involvement occurs in 5%-40% of all patients. Hypothalamic manifestations occur in 31% of Whipple encephalopathy, including polydipsia, hyperphagia, change in libido and insomnia. We report a case of a 48-year-old man with severe insomnia, depression, dementia, dysarthria, myoclonic movements of the limbs and ophthalmoplegia. The diagnosis of Whipple encephalopathy was confirmed by PCR analysis of blood and faeces. He received a full dose of antibiotic treatment. Despite clinical improvement, resolution of the lesions detected in MRI scan of the brain and negative results of the PCR in blood, faeces and cerebrospinal fluid six months later, insomnia persisted and finally subsided after the administration of carbamazepine (600 mg/day). Our case supports the finding that carbamazepine might be useful in the treatment of insomnia associated with Whipple encephalopathy.

Analgesics, Non-Narcotic↗

Investigation of possible cytokine induction in peripheral blood mononuclear cells by heat-stable serotypes of Campylobacter jejuni.

Several Campylobacter jejuni heat-stable (HS) serotypes have been associated with the autoimmune Guillain-Barre neurological syndrome (GBS). In order to examine the possible involvement of cytokines in this phenomenon, the levels of three pro-inflammatory cytokines (interleukin (IL)-2sRa, IL-6 and interferon (IFN)-gamma) and one anti-inflammatory cytokine (IL-10) were measured in peripheral blood mononuclear cells after induction by different C. jejuni serotypes. No differences were found for IL-6, IFN-gamma and IL-10, but the non-sialylated serotype HS:3 was associated with decreased production of IL-2sRa. The results raise the possibility that absence of sialylation might be associated with the inability to induce inflammatory factors such as cytokines.

Autoimmunity↗

Campylobacter jejuni O:19 serotype-associated Guillain-Barré syndrome in a child: the first case reported from Greece.

We present a case of Guillain-Barré syndrome (GBS) following Campylobacter jejuni HS serotype O:19 infection in a child. Antibodies against C. jejuni and autoantibodies to the peripheral nerve gangliosides GM1 were positive, a pattern correlating well with the existence of an inflammatory neuropathy like GBS. The patient shared the HLA-B35 and HLA-DR8 antigens, which have been found to be increased in GBS patients with previous C. jejuni infection. As this is the first diagnosed C. jejuni-associated GBS case reported from Greece, further clinical and epidemiologic investigations are warranted.

Antibodies, Bacterial↗

Antimicrobial susceptibility patterns of Campylobacter jejuni strains isolated from hospitalized children in Athens, Greece.

The antimicrobial susceptibility of 129 Campylobacter jejuni strains, isolated from hospitalized children with gastroenteritis, to five antimicrobials, including nalidixic acid, ciprofloxacin, erythromycin, ampicillin and co-amoxiclav, was determined. Isolates belonged to two time periods: group A contained strains isolated in 1987-1988; and group B 1998-2000. Antimicrobial susceptibility patterns differed significantly between the two groups with respect to quinolones, with an increase in the percentage of resistant strains in group B (30.6% versus 0% in group A), whereas erythromycin, ampicillin and co-amoxiclav were effective drugs in both groups.

Anti-Bacterial Agents↗

Prevalence of Yersinia plasmid-encoded outer protein (Yop) class-specific antibodies in patients with Hashimoto's thyroiditis.

OBJECTIVE: To investigate the prevalence of class-specific antibodies (IgG, IgA) to Yersinia enterocolitica plasmid-encoded outer proteins (Yops) in patients with diagnosed Hashimoto's thyroiditis. METHODS: Seventy-one patients with Hashimoto's disease, 464 healthy blood donors and 250 patients with non-postinfectious rheumatic disorders (matched controls) were tested for class-specific antibodies to Yops. Anti-Yop antibodies were determined by ELISA and Western blot. RESULTS: The prevalence of class-specific antibodies to Yops as determined by ELISA was 14-fold higher (20 of 71; 28.2%) in people with Hashimoto's thyroiditis than in the two control groups. These results were confirmed by the Western blot, with 16 positive sera, three equivocal and one negative. CONCLUSIONS: There is strong clinical and seroepidemiologic evidence for an immunopathologic causative relationship between Yersinia enterocolitica infection and Hashimoto's thyroiditis. Further investigation concerning the mechanisms involved and the possible effects of antibacterial chemotherapy on the outcome of Hashimoto's disease is warranted.

Adult↗

Ties in proximity and clustering compounds.

Hierarchical clustering algorithms such as Wards or complete-link are commonly used in compound selection and diversity analysis. Many such applications utilize binary representations of chemical structures, such as MACCS keys or Daylight fingerprints, and dissimilarity measures, such as the Euclidean or the Soergel measure. However, hierarchical clustering algorithms can generate ambiguous results owing to what is known in the cluster analysis literature as the ties in proximity problem, i.e., compounds or clusters of compounds that are equidistant from a compound or cluster in a given collection. Ambiguous ties can occur when clustering only a few hundred compounds, and the larger the number of compounds to be clustered, the greater the chance for significant ambiguity. Namely, as the number of "ties in proximity" increases relative to the total number of proximities, the possibility of ambiguity also increases. To ensure that there are no ambiguous ties, we show by a probabilistic argument that the number of compounds needs to be less than 2(n 1/4), where n is the total number of proximities, and the measure used to generate the proximities creates a uniform distribution without statistically preferred values. The common measures do not produce uniformly distributed proximities, but rather statistically preferred values that tend to increase the number of ties in proximity. Hence, the number of possible proximities and the distribution of statistically preferred values of a similarity measure, given a bit vector representation of a specific length, are directly related to the number of ties in proximities for a given data set. We explore the ties in proximity problem, using a number of chemical collections with varying degrees of diversity, given several common similarity measures and clustering algorithms. Our results are consistent with our probabilistic argument and show that this problem is significant for relatively small compound sets.

Journal Article↗