Striatal monoamine neurotransmitters and metabolites in dominantly inherited olivopontocerebellar atrophy.

We measured the levels of the monoamine neurotransmitters and metabolites in striatum of 14 patients with end-stage dominantly inherited olivopontocerebellar atrophy (OPCA). On average, dopamine levels were reduced in putamen (-53%), caudate (-35%), and nucleus accumbens (-31%). However, individual patient values showed a wide variation, indicating that mild to moderate striatal dopamine loss is a common but not constant feature of OPCA. Seven patients had marked putamen dopamine loss (-62% to -81%) but without evidence of correspondingly severe substantia nigra cell damage; this suggests the possibility of a "dying-back" phenomenon in which nerve terminal loss precedes cell body degeneration. Severe substantia nigra cell loss with almost total (-95% to -99%) putamen and caudate dopamine depletion was present in two patients; however, none of the 14 patients had had a clinical diagnosis of parkinsonism or was receiving antiparkinsonian medication. Mean striatal serotonin levels were normal, whereas concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid were elevated by 47% to 63%; this suggests increased activity of raphe dorsalis serotonin neurons innervating the striatum, which might aggravate the functional consequences of the dopamine deficit.     

2F3 Monoclonal Antibody Recognizes the O26 O-Antigen Moiety of the Lipopolysaccharide of Enterohemorrhagic Escherichia coli Strain 4276

Enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) organisms are groups of pathogenic strains whose infections are characterized by a typical lesion of enterocyte attachment and effacement. They are involved in enteric diseases both in humans and in animals, and EHEC strains can be responsible for hemolytic uremic syndrome in humans. Previously, it was shown that the 2F3 monoclonal antibody (MAb) is specific for the O26 EHEC and EPEC strains (P. Kerr, H. Ball, B. China, J. Mainil, D. Finlay, D. Pollock, I. Wilson, and D. Mackie, Clin. Diagn. Lab. Immunol. 6:610-614, 1999). As these groups of bacteria play an important role in pathology, the aim of this paper was to characterize the antigen recognized by the 2F3 MAb and its genetic determinant. A genomic locus containing the entire O-antigen gene cluster and half of the colanic acid gene cluster from an O26 EHEC strain was shown to be sufficient for the production of the antigen recognized by the 2F3 MAb in an E. coli DH5α strain. By transposon mutagenesis performed on the recombinant plasmid, all 2F3 enzyme-linked immunosorbent assay-negative mutants had their transposons inserted into the O-antigen gene cluster. The O-antigen gene cluster was also cloned from an O26 EHEC strain into the E. coli DH5α strain, which then produced a positive result with the 2F3 MAb. Further analysis of the type of lipopolysaccharides (smooth or rough) produced by the clones and mutants and of the O antigen of the 2F3-positive clones confirmed that the epitope recognized by the 2F3 MAb is located on the O antigen in the O26 EHEC and EPEC strains and that its genetic determinant is located inside the O-antigen gene cluster.     

An analysis of myeloma plasma cell phenotype using antibodies defined at the IIIrd International Workshop on Human Leucocyte Differentiation Antigens.

Fresh bone marrow from 43 cases of myeloma and three cases of plasma cell leukaemia has been phenotyped both by indirect immune-rosetting and, on fixed cytospin preparations, by indirect immunofluorescence. Both clustered and unclustered B cell associated antibodies from the IIIrd International Workshop on Human Leucocyte Differentiation Antigens were used. The results confirm the lack of many pan-B antigens on the surface of myeloma plasma cells, i.e. CD19-23, 37, 39, w40. Strong surface reactivity is seen with CD38 antibodies and with one CD24 antibody (HB8). Weak reactions are sometimes obtained with CD9, 10 and 45R. On cytospin preparations CD37, 39 and w40 are sometimes weakly positive, and anti-rough endoplasmic reticulum antibodies are always strongly positive. Specific and surface-reacting antiplasma cell antibodies are still lacking.     

Adjunctive low-dose doxycycline therapy effect on clinical parameters and gingival crevicular fluid tissue plasminogen activator levels in chronic periodontitis

Objective and design: The present study examined effectiveness of low-dose doxycycline (LDD) in combination with nonsurgical therapy on gingival crevicular fluid (GCF) tissue plasminogen activator (t-PA) levels and clinical parameters in chronic periodontitis (CP) a over 12-month period. Methods: GCF samples were collected, probing depth (PD), clinical attachment level (CAL), gingival index (GI) and plaque index were recorded at baseline, 3, 6, 9 and 12 months. CP patients (n = 65) were randomized to LDD or placebo groups. LDD group received LDD (20 mg) b.i.d for 3-months plus and root planing (SRP), while placebo group was given placebo capsules b.i.d for 3-months plus SRP. GCF t-PA levels were determined by ELISA. Friedman, Wilcoxon and Mann-Whitney test was used for statistical analysis. Results: Significant improvement was observed in all clinical parameters in both groups over 12-month period (p < 0.01). LDD group had lower PD, CAL and GI scores than placebo group at 6, 9 and 12-months (p < 0.05). GCF t-PA levels reduced in both groups over 12-month period (p < 0.01). LDD group had lower GCF t-PA levels than placebo group at 6 and 9-months (p < 0.05). Conclusions: These results provide additional information about usefulness of LDD therapy as an adjunct to nonsurgical therapy in long-term management of periodontitis. Received 8 May 2006; returned for revision 13 June 2006; accepted by J. Di Battista 12 July 2006     

Selecting relevant electrode positions for classification tasks based on the electro-encephalogram

The aim is to describe a general approach to determining important electrode positions when measured electro-encephalogram signals are used for classification. The approach is exemplified in the frame of the brain-computer interface, which crucially depends on the classification of different brain states. To classify two brain states, e.g. planning of movement of right and left index fingers, three different approaches are compared: classification using a physiologically motivated set of four electrodes, a set determined by principal component analysis and electrodes determined by spatial pattern analysis. Spatial pattern analysis enhances the classification rate significantly from 61.3±1.8% (with four electrodes) to 71.8±1.4%, whereas the classification rate using principal component analysis is significantly lower (65.2±1.4%). Most of the 61 electrodes used have no influence on the classification rate, so that, in future experiments, the setup can be simplified drastically to six to eight electrodes without loss of information.     

Expression of the 40 kDa catecholamine regulated protein in the normal and injured rat retina

Catecholamine regulated protein 40 (CRP40) has been shown to be expressed in the central nervous system (CNS) of several mammalian species where it may function in a similar manner to members of the heat shock protein (HSP) family. Immunohistochemical and immunoblotting techniques were utilized to investigate whether CRP40 is expressed in normal rat retinas. In addition, changes in CRP40 expression were studied following optic nerve transection. The immunohistochemical results showed that CRP40 is expressed in the normal rat retina. The protein was found to be highly expressed in the ganglion cell layer (GCL), the inner nuclear layer (INL) and the outer plexiform layer (OPL). In addition, a low level of CRP40 was found in the inner plexiform layer (IPL), and in the inner segment layer (ISL). No expression was found in the outer nuclear layer (ONL) of normal rat retina. The immunoblotting results show that CRP40 expression decreased in a time-dependent fashion after the optic nerve transection. This decrease indicates that the expression of CRP40 is dependent on the neuron's normal physiological state and that it plays an important function in physiological and pathological conditions in the retina.     

Folic acid and vitamin B12 levels in pregnancy and their relation to megaloblastic anaemia

There is a significant fall in the serum folic acid level during pregnancy, reaching its lowest level at term. This is most pronounced in twin pregnancies. A similar but less spectacular fall occurs in the vitamin B₁₂ concentration.     

Thrombopoietin receptor (Mpl) expression by megakaryocytes in myeloproliferative disorders

The thrombopoietin receptor (Mpl) is involved in the pathogenesis of chronic myeloproliferative disorders (CMPD). In this study, we determined Mpl expression by bone marrow cells and megakaryocytes in CMPD by applying laser microdissection, real-time RT-PCR, and immunohistochemistry. Mpl mRNA expression was significantly increased up to 9-fold in total bone marrow cells (p < 0.001) and up to 4-fold in megakaryocytes in chronic myeloproliferative disorders (n = 73) compared to normal controls (n = 26, p = 0.01). Immunohistochemistry revealed heterogeneous Mpl expression by megakaryocytes in CMPD with a stronger accentuation in idiopathic myelofibrosis (IMF) in comparison to polycythaemia vera (PV) and essential thrombocythemia (ET). In addition to megakaryocytes, the erythropoietic lineage was prominently labelled by Mpl antiserum, with considerably stronger staining in polycythaemia vera. We conclude that, in CMPD, megakaryocytes and erythroid cells exhibit increased Mpl expression levels which may contribute to the sustained proliferation of both cell lineages in CMPD.     

Human lymphocyte antigens (HLA) and Graves' disease in Turkey

To evaluate the association of HLA types with Turkish patients with Graves' disease, HLA typing, clinical findings, and thyroid antibodies were correlated. The HLA types, clinical findings (ophthalmopathy and age at onset), and thyroid stimulating hormone (TSH) receptor (TRAb) and antithyroid microsomal antibodies (MAb) were analyzed. Seventy Turkish patients with Graves' disease and 306 control subjects were assessed. Serological HLA typing was performed in HLA A, B, C, DR, and DQ loci. There was a significantly increased prevalence of HLA B8, B49, DR3, DR4, and DR10 in Graves' disease. The association of Graves' disease with HLA DR3 was found to be less strong than previously described. The HLA DR4 antigen may contribute to the predisposition of Graves' disease in Turkey. The results suggest that HLA B7, B13, DR7, DQw2, and DQw3 may confer a protective effect for Graves' disease in Turkey. Patients carrying HLA B12, B18, and B44 haplotypes had a tendency to develop the disease at a later age. The difference from the other studies may be the result of the selection of the controls; in part, of the variability in serological typing reagents; and, also, of the rather weak HLA associations with the disease.This study was presented in part at the Annual Meeting of the National Endocrinology and Diabetes Association, Bursa, Turkey, May 25–28, 1992.