Serotonergic interhemispheric asymmetry: Neurochemical and pharmaco-EEG evidence

1. Postmortem neurochemical investigations revealed interhemispheric asymmetry in the mediofrontal region of human brain. Significantly higher right hemisphere serotonin metabolite (5HIAA) content as well as increased maximal imipramine binding (IB) were found in the right hemisphere than in the left side.

2. IB did not show a gender difference in the mediofrontal area. However, women had higher IB in the right orbital frontal cortex than did men.

3. In vivo pharmaco-EEG results tend to support the postmortem neurochemical data. Intravenous chlorimipramine resulted in an asymmetric topographic distribution of the P300 auditory evoked potential, peak amplitudes were shifted to the right hemisphere.     

Comparison of FK-506 and cyclosporine regimens in pediatric renal transplantation

Clinical aspects of FK-506 or cyclosporine immunosuppression regimens were evaluated in 48 consecutive pediatric renal transplant recipients. Tapering and discontinuation of prednisone was employed only in children receiving FK-506 who experienced minor or no rejection episodes during the 1st posttransplant month. At 1 year follow-up, 17 of 22 (77%) of all children with functioning allografts were receiving no prednisone (n=13) or a mean dosage of 0.07 mg/kg per day (n=4). During the 1st month, acute cellular rejection was more common in the FK-506 group (0.58 vs. 0.21 rejections per patient,P<0.05) but allograft survival (92%) and renal function at 1 year posttransplant were identical in both groups. Compared with the cyclosporine regimen, FK-506 immunosuppression may be associated with a higher incidence of cytomegalovirus or reversible Epstein-Barr virus-induced lymphoproliferative disease. However, the FK-506 group had less hirsutism and gingival hypertrophy and required fewer antihypertensive medications independent of steroid use. Height standard deviation scores and weight-for-height index improved only in preadolescents receiving FK-506 but no prednisone (P<0.02 andP<0.05, respectively), but did not differ between children on FK-506 plus prednisone and those in the cyclosporine group. We conclude that the major advantages of FK-506 over cyclosporine immunosuppression are a reduced severity of hypertension and an improved cosmetic appearance which may improve long-term medical compliance. When used as monotherapy, FK-506 also shows promise in relieving the growth retardation associated with cyclosporine regimens that include prednisone.     

Thin-layer chromatography systems for the identification of Mycobacterium tuberculosis, M. bovis BCG, M. kansasii, M. gastri and M. marinum.

Knowledge of mycobacterial glycolipid antigens and the study of their specificity have resulted in their utilization as species markers. We describe a thin-layer chromatography method which could serve as a useful adjunct for the identification of Mycobacterium tuberculosis, M. bovis BCG, M. kansasii, M. gastri and M. marinum.     

Telomere length analysis on cord blood cells by the flow-FISH method

Telomerase is the enzyme responsible for synthesizing telomeric repeats at the ends of chromosomes to maintain telomere length. Recent studies have suggested that telomere shortening may serve as a surrogate marker of the progression of malignant disorders and seems to be accelerated in allogeneic bone marrow transplant recipients. In this study, the results of the telomere length of nine cord blood mononuclear cell samples are presented. Telomere length was measured by the flow-FISH method, using a peptide nucleic acid probe. The proportion of cord blood cell subsets (CD19/CD34/CD3) was also evaluated. The telomere length of the internal control 1301 cell line was estimated to be 100%. The mean telomere length of cord blood cells was 18.5 +/- 3.9%, compared with the internal control. The progenitor CD34+ cells were detected as 2.6 +/- 0.7% in the lymphoid gate measured. Linear correlation analysis did not find any connection between the cell subsets (CD3+, CD34+, CD19+) and the telomere length. The findings confirm that the telomere flow-FISH method is sufficient for estimation of the telomere length. Assessment of the current procedures of collection, manipulation, and ex vivo expansion of cord blood cells in terms of their effect on telomere shortening might be important.     

Detection of pYV+ Yersinia enterocolitica isolates by P1 slide agglutination.

Rabbit polyclonal antisera were raised against the pYV-encoded outer membrane protein P1 of five Yersinia enterocolitica strains belonging to serogroups O:3, O:5,27, O:8, and O:9. Analysis of these strains with the sera showed that P1 presented at least six different antigenic factors. Two of the serum specimens were chosen to test the P1 agglutinability of 797 strains isolated from various sources. This technique appeared to be more reliable than autoagglutination and Ca2+ dependency to monitor the presence of the pYV plasmid. Hence, we propose this P1-mediated agglutination as a new and easy virulence test.     

Analysis of genetic polymorphism in the phospholipase region of Mycobacterium tuberculosis.

mtp40 was originally identified as a short genomic region that was found in strains of Mycobacterium tuberculosis but not in Mycobacterium bovis. Subsequent studies have revealed that the sequence is part of the mpcA gene, which encodes a phospholipase C. To investigate further the distribution of the mtp40 sequence, we analyzed strains of the M. tuberculosis complex by PCR and were able to amplify the mtp40 sequence in 90 of 94 strains of M. tuberculosis and in 2 strains of Mycobacterium microti but not in M. bovis or M. bovis BCG. Based on this, we developed a dot blot assay using genomic DNA which allows M. bovis to be distinguished from the majority of M. tuberculosis strains. We also probed Southern blots of 140 clinical isolates of M. tuberculosis to determine the frequency of strains lacking mtp40. This revealed an unexpected polymorphism in the phospholipase region. Two fragments were detected in 57% of samples. The expected fragment of 0.75 kbp corresponds to the region of mpcA containing mtp40. A 2.1-kbp fragment was observed to belong to a recently discovered second phospholipase gene, mpcB. In addition, some strains appeared to lack both genes, while others showed only the presence of mpcA. A few strains had additional bands, suggesting the existence of other homologs to the two phospholipase genes. We also detected the insertion of IS6110 in the mpcA coding region of one strain. The absence of these genes in some clinical isolates raises questions about their function during infection and in the development of tuberculosis disease in humans.     

Electron microscopic analysis of two-dimensional crystals of the Ca2+-transport ATPase — a freeze-fracture study

Summary Two distinct forms of Ca²⁺-ATPase crystals have been analysed in sarcoplasmic reticulum (SR) membranes. The E₁-type crystals, induced by Ca²⁺ or lanthanide ions, consist of single chains of ATPase monomers, and the E₂-type crystals, induced by vanadate ions, consist of dimer chains. Using improved freeze-fracture techniques we have obtained high-resolution images of complementary surface replicas of SR membranes containing these crystal forms. In E₁ crystals, the concave fracture (P) faces display obliquely oriented rows of intramembrane particles (IMPs) spaced at - 6–7 nm along both crystal axes, while the convex fracture (E) faces show corresponding rows of pits. In E₂ crystals, regular arrays of oblique parallel ridges with spacing of - 10.5–11 nm appear on the P-faces and complementary grooves or furrows on the E-faces. In many instances the ridges break up into elongated particles repeating every 5.5 nm. When the direction of the shadow is almost parallel to the axis of the ridges, these 9.5 nm particles can be resolved into two domains, which represent intramembranous contacts between the two monomers of the two adjacent dimer chains. Complementary grooves on the E-faces can also be resolved into rows of pits complementary to the particles of the ridges on the P-faces. In the control SR membranes, randomly dispersed IMPs and corresponding pits are observed on the P- and E-faces, respectively. The data suggest that transport of Ca²⁺ involves significant structural changes of the enzyme molecule, reflected in the ATPase-ATPase interactions both on the cytoplasmic surface and in the lipid bilayer.