Detection of Parkin (PARK2) and DJ1 (PARK7) mutations in early-onset Parkinson disease: Parkin mutation frequency depends on ethnic origin of patients

Mutations in the Parkin (PARK2) and the DJ1 (PARK7) gene cause early-onset Parkinson disease (EOPD). We tested 75 Serbian EOPD patients for mutations in both genes by conventional mutational screening (SSCP/dHPLC/sequencing) to detect small sequence alterations and by gene dosage studies (quantitative PCR) to reveal deletions or multiplications of one or more exons. A compound heterozygous Parkin mutation (exon deletion and point mutation; [c.836_972del]+[c.1411C>T]; +1 is first nucleotide of GenBank AB009973.1) was identified in a patient who showed a relatively benign course after a disease onset at 41 years. Another case had a heterozygous exon deletion in DJ1 ([c.253_322del]+[?]) and presented with an age at onset of 45 years and a rapid disease course. In conclusion, Parkin mutations are surprisingly rare in our Serbian EOPD sample, suggesting that the mutation rate depends on the ethnic origin of the patients. Although DJ1 mutations appear to be rare, we confirm their role in EOPD and demonstrate the importance of gene dosage studies.     

Cross-reaction to Legionella pneumophila antigen in sera with elevated titers to Pseudomonas pseudomallei.

A significantly greater incidence (P less than 0.005) of Legionella pneumophila microagglutination titers greater than or equal to 32 was found in sera with elevated titers to Pseudomonas pseudomallei as compared with sera with negative titers for P. pseudomallei antibodies. The greater incidence of L. pneumophila titers in these sera suggests that L. pneumophila and P. pseudomallei share an antigen. The incidence of L. pneumophila microagglutination titers of greater than or equal to 32 in sera with elevated titers to Brucella abortus or Francisella tularensis is not statistically significant.     

Tunica media of aorta and pulmonary trunk in relation to internal calibres in transposition of great arteries,in aortic and pulmonary atresia and in normal hearts

Summary In a post mortem material of 17 cases of transposition of the great arteries (TGA) from patients with an age range from birth to two years and ten months after birth, the internal calibres of the great arteries and the ostia of the heart proved to be the same as in normal hearts. Furthermore, the media of the ascending aorta and pulmonary trunk showed no adaptation to the abnormal circulatory conditions in 15 cases of TGA with an age range from birth up to 51/2 months: in both great arteries the thickness of the tunica media and the packing density of its elastic fibres were the same as in normal hearts. However, adaptation of the tunica media of the pulmonary trunk to the abnormal circulatory conditions: increased media thickness, was found in the two remaining cases, older than 12 months.In 7 cases of pulmonary atresia (age from 1 day to 12 months) and in 9 cases of aortic atresia (age from 2 days to 37 days) the following observations were made. Vessels with reduced or absent function (ascending aorta in aortic atresia and pulmonary trunk in pulmonary atresia) showed a markedly different structure. In aortic atresia the internal calibre and thickness of the media of the ascending aorta were markedly reduced, whereas the packing density of the elastic fibres of the media remained the same as in normal hearts. In pulmonary atresia the pulmonary trunk showed large variations in internal calibre, whereas both media thickness and the packing density of its elastic fibres remained the same as in normal hearts. When the markedly enlarged single functional vessels (the pulmonary trunk in aortic atresia and the ascending aorta in pulmonary atresia) were compared no significant differences between their internal calibre, media thickness and the packing density of the elastic fibres were found indicating similar adaptation to the abnormal but comparable functional load of acting as sole arterial trunk.We are indebted to Prof. Dr. J. Moll for his help, to Dr. J.J. Willemse for statistical calculations, to Mr. P. Zondervan, M.D. (Dept. of Pathology I), for supply of material and to Mrs. L. Silvis for histo-technical assistance     

A technique for the identification of glycoprotein antigens in immune complexes and its application to the detection of a common glycomprotein in sera of patients with burkitt's lymphoma and nasopharyngeal carcinoma

A new technique for the detection of glycoprotein antigens in immune complexes (IC) isolated from serum is described. The technique was developed with a model IC system consisting of ovalbumin (OVA)-rabbit anti-ovalbumin antibodies (aOVA), at 3 times antigen excess. OVA-aOVA IC added to normal human serum (NHS) were purified by absorption onto and elution from tubes coated with rheumatoid factor (RF) and were subjected to electrophoresis in polycrylamide gels. Concanavalin A (Con A) binding proteins were detected by treating the gels with radioiodinated Con A ¹²⁵Con A), followed by autoradiography. IC isolated from sera of patients with Burkitt's lymphoma (BL) and Nasopharyngeal Carcinoma (NPC) were analyzed before and after reduction with dithioreitol. Two closely spaced proteins of about 40 kdalton were identified in the reduced samples in 26 of 30 BL sera (86%) and in 24 of 30 NPC sera (80%) but were not seen in 30 sera of African patients with a variety of unrelated tumors nor in 12 sera of European blood bank donors.     

The essential role of stimulus temporal patterning in enabling perceptual learning

Little is known about how temporal stimulus factors influence perceptual learning. Here we demonstrate an essential role of stimulus temporal patterning in enabling perceptual learning by showing that 'unlearnable' contrast and motion-direction discrimination (resulting from random interleaving of stimuli) can be readily learned when stimuli are practiced in a fixed temporal pattern. This temporal patterning does not facilitate learning by reducing stimulus uncertainty; further, learning enabled by temporal patterning can later generalize to randomly presented stimuli.     

Identification of surface-exposed B-cell epitopes recognized by Haemophilus influenzae type b P1-specific monoclonal antibodies.

A panel of P1 synthetic peptides was synthesized to map the surface-exposed epitopes of Haemophilus influenzae type b outer membrane protein P1 recognized by three murine monoclonal antibodies (MAbs 7C8, 3E12, and 6B1). By using peptide-specific enzyme-linked immunosorbent assays, MAbs 6B1, 7C8, and 3E12 were shown to recognize distinct epitopes localized within residues 60 to 88, 165 to 193, and 400 to 437 of mature P1, respectively. Since MAb 7C8 was shown previously to be protective against certain H. influenzae type b subtypes in the infant rat model of bacteremia, its cognate epitope was further characterized by using truncated peptide analogs. Fine mapping of the 7C8 epitope by competitive inhibition studies revealed that it was localized within residues 184 and 193.     

Role for mannose binding lectin in the prevention of Mycoplasma infection

Polymorphisms in exon 1 of the MBL-2 gene, resulting in reduced plasma levels of mannose binding lectin, were significantly overrepresented in 23 patients with primary antibody deficiency and culture-proven mycoplasma infections (P = 0.0038). This association persisted with the inclusion of a further nine suspected (doxycycline-responsive) cases (P = 0.0087). The lectin was shown to bind to three strains of mycoplasma.     

Correlation of viscoelastic properties with the molar mass distribution for aqueous polyacrylamide solutions

The dependence of viscous and elastic rheological functions on molar mass and molar mass distribution was investigated under shear flow conditions using concentrated solutions of polyacrylamides and polyacrylamide mixtures. The zero-shear viscosity η₀ correlates with the weight-average molar mass M?_w; with increasing shear rate the corresponding controlling molar mass average tends to change to the number-average molar mass M?_n. It is shown that the analysis of the shape of the whole flow curve is a simple way to obtain qualitative information about molar mass distribution. Elastic forces are influenced mainly by the high-molar-mass tail of a molar mass distribution. The zero normal stress coefficient ψ₀ depends on a molar mass average between M?_w and z-average molar mass M?_z·ψ₀ increases with the 7,4th power of the molar mass for the polyacrylamides (not for the mixtures). The steady-state compliance J_e⁽⁰⁾ is, for the investigated system, independent of the absolute molar mass, but increases with the 5,5th power of the ratio M?_z/M?_w. The elasticity modulus G₀^(A) can be correlated with M?_n of the polyacrylamide samples and their mixtures. These investigations show that the analysis of various rheological functions can lead to a wealth of information about the molar mass distribution of a polymer.     

Serological studies of monoclonal RH1(D) antibodies with RH1(D) variants

In this paper we chose to emphasize three aspects of our work. First we underlined that “low grade and high grade” D weak red blood cells studied at the DNA level could, when monoclonal antibodies were used, give patterns of positive and negative reactions like partial RH1(D) cells. Secondly, we showed the importance of the technical conditions of the study which are essential for establishing a pattern of reactivity defining an epitope. It appears that the use of papain treated cells at room temperature can be misleading for the definition of epitope especially with IgM antibodies. Lastly we pointed out the interest of Rh variant cells, defined at the gene level, to study the expression of RH1(D) epitopes on the external part of the membrane.