Occurrence and Potential Diagnostic Applications of Serological Cross-Reactivities between Brucella and Other Alpha-Proteobacteria

Agrobacterium, Sinorhizobium, and Ochrobactrum are genera closely related to Brucella but, in contrast to the latter, are not pathogenic for humans and animals. We studied by an indirect enzyme-linked immunosorbent assay (ELISA) the reactivities of brucellosis sera against cytosolic (CYT) and membrane (MA) antigens from these nonpathogenic bacteria, and we evaluated the potential usefulness of these cross-reactions for the diagnosis of brucellosis in humans, sheep, cows, and dogs. Canine infection by Brucella canis was detected with high specificity by CYT antigen-based ELISAs (96% for Agrobacterium, 96% for Sinorhizobium, and 91% for Ochrobactrum), while sensitivity was variable (58% for Agrobacterium, 88% for Sinorhizobium, and 84% for Ochrobactrum). In addition, it was possible to diagnose canine disease shortly after exposure to the pathogen (15 days). Similar results for canine brucellosis were obtained with MA antigens. In contrast, normal sera from humans, sheep, and cattle reacted strongly with all the antigens (CYT and MA antigens from the three bacteria), producing high cutoff values and, consequently, low sensitivities. While for some host species the reactivity patterns of normal sera by Western blotting were similar to those produced with sera from infected individuals, the reactivity pattern of bovine sera against Sinorhizobium meliloti antigens exhibited some differential bands for the two groups of sera. These results show that crude fractions from nonpathogenic alpha-proteobacteria can be used to diagnose canine brucellosis but may need to be further separated into simpler fractions to have diagnostic usefulness in ovine, bovine, or human infection. By reducing the biosafety requirements, the use of antigens derived from these nonpathogenic bacteria would simplify the production of diagnostic kits for brucellosis, especially in settings where biosafety level-3 facilities are scarce or absent.     

S-adenosyl-L-methionine prevents 5-HT(1A) receptors up-regulation induced by acute imipramine in the frontal cortex of the rat

S-adenosyl-L-methionine (SAM) has shown efficacy in speeding the onset of the antidepressant effect of imipramine in depressed patients. This effect may be related to their interactions at the serotonin(1A) (5-HT(1A)) receptors. Acute imipramine up-regulated the frontal cortex 5-HT(1A) receptors (B(max), 51.5 +/- 8.4 fmol/mg protein) vs. saline (B(max), 27.5 +/- 5.9 fmol/mg protein), and did not show antidepressant effect. Acute SAM and imipramine+SAM did not modify frontal cortex 5-HT(1A) receptors, and showed antidepressant effects (decrease of the immobility response of 26%, P<0.01; and 47%, P<0.001) vs. saline. All the chronic treatments showed antidepressant effects and up-regulated the hippocampus 5-HT(1A) receptors. SAM prevents the 5-HT(1A) receptor up-regulation induced by acute imipramine in the frontal cortex. This mechanism may contribute to imipramine's antidepressant effect.     

Epitope focus, clonal composition and Th1 phenotype of the human CD4 response to the secretory mycobacterial antigen Ag85

Lymphoproliferation of healthy donors was tested against mycobacterial antigens (PPD, Ag85, Ag85 peptides). All PPD responders recognized the secretory antigen Ag85 and the peptide specificity for Ag85B was defined. Peptide 91-108 was recognized by 85% of donors. In addition, all CD4 T cell lines generated from 12 donors against PPD or Ag85 responded to 91-108. When this peptide was used to generate T cell lines, the cells responded also to tuberculins from atypical mycobacterial species. Thus the cross-reactive peptide behaved as quasi-universal. The analysis of TCR-BV gene usage by cell lines showed that most Ag85-specific T cells correspond to 91-108-specific clonotypes. Intracytoplasmic staining of cell lines after phorbol myristate acetate stimulation resulted in dominance of interferon-gamma (IFN-gamma)-IL-4 double-positive cells, whereas antigen stimulation resulted in production of IFN-gamma only. The data show that peptide 91-108 is the major focus of the CD4 response to mycobacterial antigens in peripheral blood mononuclear cells and in T cell lines from PPD responders.     

The novel HLA-Cw*1802 allele is associated with B*5703 in the Bubi population from Equatorial Guinea

The HLA-Cw*1801 specificity, a Cw7/Cw4 hybrid allele, has recently been described in association with B*8101 (formerly B"DT"). In this study, the new Cw*1802 variant, differing from Cw*1801 at exon 5. is found associated with B*5703 in Bubi individuals from Equatorial Guinea. Confirmatory complete coding regions of B*5703 and B*3910 are also reported.     

Molecular cloning of Proteus mirabilis uroepithelial cell adherence (uca) genes.

Proteus mirabilis bacteria are a common cause of hospital-acquired urinary tract infection. In a previous study, we described a P. mirabilis fimbrial protein, UCA, that adhered to human uroepithelial cells. Genes sufficient for expression of UCA adherence were cloned into Escherichia coli K-12. E. coli bacteria that contained the uca recombinant plasmid adhered to human uroepithelial cells. In addition, the ucaA gene encoding the structural component of UCA pili was subcloned, and its DNA sequence was determined. Amino acid sequence homology (30 to 50%) was found between mature UcaA protein and pilins from pathogenic bacteria representing several genera, including E. coli F17, G, and type 1C pilins, Haemophilus M43 pilin, and a Bordetella pilin.     

Kallmann syndrome: 14 novel mutations in KAL1 and FGFR1 (KAL2)

Kallmann syndrome (KAL) combines hypogonadotropic hypogonadism and anosmia. Hypogonadism is due to Gonadotropin Releasing Hormone (GnRH) deficiency and anosmia is related to hypoplasia of the olfactory bulbs. Occasional symptoms include renal agenesis, bimanual synkinesia, cleft lip palate, dental agenesis. KAL is genetically heterogeneous and two genes have so far been identified, namely KAL1 (Xp22.3) and FGFR1/KAL2 (8p12), which underlie the X chromosome‐linked form and an autosomal dominant form of the disease, respectively. We studied a cohort of 98 unrelated Caucasian KAL patients. We identified KAL1 mutations in 14 patients, of which 7 (c.3G>A (p.M1?), g.IVS1+1G>T, c.570_571insA (p.R191fsX14), c.784G>C (p.R262P), c.958G>T (p.E320X), c.1651_1654delinsAGCT (p.P551_E552delinsSX), c.1711T>A (p.W571R)) have not been previously reported. In addition, we found FGFR1 mutations in 7 patients, namely c.303G>A (p.V102I), C.385A>C (p.D129A), c.810G>A (p.V273M), c.1093_1094delAG (p.R365fsX41), c.1561G>A (p.A520T), c.1836_1837insT (p.Y613fsX42), c.2190C>G (p.Y730X), all of which were novel mutations. In this study, unilateral renal agenesis and bimanual synkinesia were exclusively found associated with KAL1mutations, cleft palate and dental agenesia with FGFR1mutations. © 2004 Wiley‐Liss, Inc.     

Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping

Background  

Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets.     

Neutralizing antibodies in HIV (HTLV-III) infection: correlation with clinical outcome and antibody response against different viral proteins.

Sequential serum samples, collected over a 2-3 year follow-up period, of 28 HIV-infected individuals were tested for the presence of neutralizing antibodies against one HIV isolate, HTLV-IIIB, and titrated, by Western blotting, against different HTLV-III specific proteins. Neutralizing antibodies were found in 66% of the samples tested and highest neutralization titres observed in cases with lymphadenopathy syndrome. Antibody titres against the viral proteins also seemed to be highest in cases with LAS. Neutralization titres correlated well with antibodies to envelope glycoproteins gp41 and gp120 and to one of the core proteins, p17. An increase in neutralization titre during the follow-up period was associated with a stable clinical course. Furthermore, the occurrence of antibodies directed against the external envelope glycoprotein (gp120) in the initial serum sample correlated well with a stable clinical course. The results suggest that neutralizing activity in the serum, particularly that evoked against gp120, may have some prognostic significance, and that several distinct antigenic epitopes on the virus may be a target for neutralizing antibodies.     

Immunohistochemical localization of laminin and type IV collagen in human cutaneous sensory nerve formations

We used immunohistochemical techniques and monoclonal antibodies to localize two basement membrane components (laminin and type IV collagen) in the nerves and sensory nerve formations, or corpuscles, supplying human digital skin. Furthermore, neurofilament proteins, S-100 protein and epithelial membrane antigen were studied in parallel. In dermal nerve trunks, immunostaining for laminin and type IV collagen was found to be co-localized in the perineurium and the Schwann cells, the stronger immunoreactivity being at the external surface of the cells. In the Meissner digital corpuscles, the immunoreactivity for laminin and type IV collagen was mainly observed underlying the cell surface of lamellar cells, while the cytoplasm was weakly immunolabelled or unlabelled. Finally, within Pacinian corpuscles co-localization of the two basement membrane molecules was encountered in the inner core, intermediate layer, outer core and capsule. Laminin and type IV collagen immunoreactivities were also found in blood vessels and sweat glands, apparently labelling basement membrane structures. The present results provide evidence for the presence of basement membrane in all periaxonic cells forming human cutaneous sensory nerve formations, and suggest that all of them are able to synthesize and release some basement membrane components, such as laminin and type IV collagen. The possible role of laminin in sensory nerve formations is discussed.     

Prognostic value of early somatosensory evoked potentials during carotid surgery: Relationship with electroencephalogram,stump pressure and clinical outcome

Summary The authors have reported on the prognostic value of continuous monitoring of somatosensory evoked potentials (SEP) in a survey of 25 patients who underwent carotid surgery. SEP recordings were correlated with the EEG, stump pressure (SP) values and clinical outcome. A non-cephalic reference was used for SEP recordings to allow the analysis of both subcortical and cortical components. During surgery the conduction time between SEP peaks relating to the subcortical components remained stable or showed minimum variations in all patients. During carotid clamping, SEP variations were observed in 9 out of 25 cases (36%). The application of an intraluminal shunt was accompanied by the return to normal values in 7 out of 9 patients. In the remaining two cases SEP abnormalities continued post-operatively and were accompanied by new neurological deficits. EEG changes during carotid clamping were associated with SEP modifications in 6 out of 7 cases, although they were not always correlated. Results confirm that SEP recordings provide useful data concerning the function of the CNS in anaesthetized patients and that, being sensitive to CBF changes, SEP monitoring acts as an indicator of cerebral ischaemia.Presented in part at the Third International Evoked Potentials Symposium, Berlin-West, September 28th–October 1st, 1986.