Serodiagnosis of Helicobacter hepaticus infection in mice by an enzyme-linked immunosorbent assay.

Helicobacter hepaticus is a newly recognized bacterium associated with chronic active hepatitis, hepatic carcinoma, and inflammatory bowel disease in mice. Currently, fecal or tissue PCR, fecal culture, or histologic examination of silver-stained liver sections is used to diagnose H. hepaticus infection. In this report, we describe an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of H. hepaticus infection in mice with a membrane digest preparation of H. hepaticus as the antigen. Sera from mice positive for H. hepaticus by PCR or histologic examination (n = 88), positive for Helicobacter bilis by PCR (n = 13), positive for other helicobacters (not identifiable to species level) by PCR (n = 25), or negative for all Helicobacter species by PCR (n = 162) were used to evaluate the ELISA. Results indicated that ELISA provided 93.2% sensitivity, 94% specificity, 87.2% positive predictive value, and 96.9% negative predictive value. Cross-reactive antibodies were detected in some mice infected with helicobacters not identifiable to species level. To further define ELISA sensitivity and specificity, groups of 10 C57BL/6 mice were inoculated per os with H. hepaticus, Helicobacter muridarum, or H. bilis. Sera were collected and examined by the ELISA. H. hepaticus-infected mice seroconverted by 2 weeks and maintained ELISA reactivity throughout the 18-week study, while mice infected with H. muridarum and H. bilis were negative by ELISA. These results indicate that this reported ELISA is highly sensitive and specific for the serodiagnosis of H. hepaticus infection in mice.     

ICAM-1, VCAM-1, and MAdCAM-1 are expressed on choroid plexus epithelium but not endothelium and mediate binding of lymphocytes in vitro.

The expression of cell adhesion molecules (CAMs) in the choroid plexus was studied in normal brain and during experimental autoimmune encephalomyelitis (EAE) in the SJL/J mouse during inflammation induced by intracerebral injection of killed Corynebacterium parvum in the C3H/He mouse. Both ICAM-1 and VCAM-1, but not MAdCAM-1, were constitutively expressed on choroid plexus epithelium but not on the fenestrated capillary endothelial cells within the choroid plexus. During EAE, we observed an up-regulation of ICAM-1 and VCAM-1 and de novo expression of MAdCAM-1 on choroid plexus epithelial cells. In contrast, endothelial cells in the choroid plexus were not induced to express any of the investigated CAMs. In in situ hybridization analysis we demonstrated that ICAM-1, VCAM-1, and MAdCAM-1 were locally synthesized and that the amount of their mRNAs increased in the inflamed choroid plexus. In vitro, primary choroid plexus epithelial cells could be induced to express ICAM-1, VCAM-1, and MAdCAM-1 on their surface after treatment with proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin-1, interferon-gamma, and lipopolysaccharide. To investigate the functional status of the expressed CAMs we performed Stamper-Woodruff binding assays on frozen sections of inflamed and naive brains. ICAM-1, VCAM-1, and MAdCAM-1 expressed in choroid plexus epithelial cells mediated binding of lymphocytes via their known ligands LFA-1 and alpha4-integrin, respectively. The expression of ICAM-1, VCAM-1, and MAdCAM-1 on choroid plexus epithelial cells together with the lack of their expression on the fenestrated choroid plexus endothelium raises the possibility that the epithelial blood-cerebrospinal-fluid barrier plays an important role in the immunosurveillance of the central nervous system.     

Gestörte alpha2-Adrenozeptorfunktion bei Hämodialysepatienten mit renaler Anämie — eine mögliche Ursache der Blutdrucksteigerung unter rekombinantem humanem Erythropoietin?

Summary Nine patients on maintenance hemodialysis and transfusion-demanding renal anemia (group A) were treated with rHuEPO 120 IU/kg i.v. three times per week. Hemoglobin-content was raised from 7.2±0.9 to 10.4±0.8 g/dl. In all patients blood pressure rose, three patients developed arterial hypertension. Mean diastoloic blood pressure was 66±12 and 78±16 mmHg (p<0.001) before and after rHuEPO. Rise in blood pressure was accompanied by a significant fall in plasma-noradrenaline-levels (from 498±100 to 383±75 pg/ml;p<0.05) and alpha₂-adrenoceptor-density (from 574±76 to 384±49;p<0.05). Compared to nine patients on maintenance hemodialysis and hematocrit over 30% (group B), patients with severe renal anemia (group A before treatment) had higher densities of alpha₂-adrenoceptors (574±76 vs. 218±32;p<0.001) despite higher plasma-noradrenaline-levels (498±100 vs. 399±63; n.s.). We suppose a anemia-related disturbance of alpha₂-receptor-function with the result of abolished receptor down-regulation and impaired vascular reagibility to vasoconstricting stimuli. With the correction of anemia receptor-function improves, receptor down-regulation as well as vascular reagibility is re-established resulting in augmented vascular resistance and higher blood pressure.

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Abkürzungen rHuEPO rekombinantes humanes Erythropoietin - teMAP mittlerer arterieller Blutdruck - RR Blutdrucknach RIVA-ROCCI - RBF regionaler Blutfluß - RPR regionaler peripherer Widerstand     

Effect of the serotonin agonist buspirone on behaviour and hypothalamic-pituitary-adrenal axis in confident and fearful mink

Behavioural and hypothalamic-pituitary-adrenal (HPA) axis responses were investigated in farm mink (Mustela vison) selected for either confident or fearful behaviour for nine generations.Two groups of 2-year-old confident (n=12) and fearful (n=12) female mink were given the serotonin (5-HT) 1A receptor agonist buspirone (1.25 mg/kg/day), whereas two other groups of 2-year-old confident (n=12) and fearful (n=12) female mink were given saline, continuously for 5 weeks via osmotic minipumps. Behavioural reactions towards a novel object and towards humans were tested after 19-25 days, and HPA axis reactivity [adrenocorticotropic hormone (ACTH), cortisol] was measured after 28-31 days of treatment. Confident mink were more exploratory than fearful mink towards humans and a novel object. Confident mink spent more time in contact with the object than did fearful mink during saline-but not during buspirone-treatment. buspirone increased approach-withdrawal conflict behaviour towards a object in fearful mink only. The chronic dose of buspirone did not reduce fear towards humans and did not affect latencies to reaction, number of contacts, number and duration of manipulations, and stereotypic behaviour in a Novel Object test. Different HPA axis responses have emerged between confident and fearful mink, together with a different degree of fear-related behaviour. Fearful mink have a higher cortisol combined with a lower ACTH secretion than confident mink in response to capture and blood sampling. The central serotonergic system may be involved, and even though the precise underlying mechanisms are presently unknown, treatment with a 5-HT(1A) receptor agonist reduces the difference between confident and fearful mink in HPA axis reactivity.     

Multilocus haplotype analyses reveal association between 5 novel IL-15 polymorphisms and asthma

BACKGROUND: IL-15 is a T(H)1-related cytokine that is involved in the inflammatory response in various infectious and autoimmune diseases. IL-15 has recently been shown to be upregulated in T-cell-mediated inflammatory disorders. The observations suggest a potential role for this cytokine in a variety of pathologic conditions, including T(H)1-mediated and T(H)2-mediated inflammatory diseases. OBJECTIVE: In this study, we searched for single nucleotide polymorphisms in the whole IL-15 gene and investigated their association with inflammatory and/or atopic phenotypes. METHODS: The screening for single nucleotide polymorphisms was performed by single-strand conformation polymorphism analysis. Genotyping of the identified polymorphisms was performed by restriction fragment length polymorphism. Genotypic association analysis used the Armitage trend test. Haplotype frequency estimation and subsequent testing for differences between cases and controls were performed by using the programs FASTEHPLUS and FAMHAP. RESULTS: We identified 5 novel noncoding nucleotide sequence variants, all of which were typed in our asthmatic, our atopic, and our control population. According to the Armitage trend test, none of the 5 polymorphisms is associated with the phenotype bronchial asthma or atopy. However, multilocus haplotype analysis based on simulations to find out whether the haplotype frequencies differed between cases and controls by using the program FAMHAP yielded a P value of 6.1 x 10(-5) in the asthmatic versus the control population, which is highly significant. Furthermore, we obtained a nominally significant result of P=.0232 for the atopic versus the control population by using FAMHAP. CONCLUSION: These results strongly underscore previous findings that suggest a potential role of this cytokine in allergic diseases.     

A B220+ CD117+ CD19- hematopoietic progenitor with potent lymphoid and myeloid developmental potential

In this report, we identify in the bone marrow (BM) of normal mice a subpopulation of B220+ CD117+ CD19- NK1.1- cells with potent lymphoid and myeloid developmental potential. These cells represent 0.1-0.2% of nucleated BM cells. By limiting dilution analysis in the presence of the appropriate combination of stromal cells and cytokines, 1 in 5-10 sorted cells formed B cells, 1 in 10-15 formed T cells and 1 in 5-10 generated macrophages. When cultured on a mixture of OP9 stroma and OP9 stromal cells expressing the Notch ligand Delta-like-1, single cells generated both T and B cells. Following intravenous infusion, freshly sorted cells transiently reconstituted both the T and B cell progenitor compartments, generating cohorts of mature T and B lymphocytes. The relationship between B220+ CD117+ CD19- NK1.1- cells of wild-type mice and other multi-lineage BM progenitors is discussed.     

Zur Katalyse der stereospezifischen Butadienpolymerisation mit den Katalysatorsystemen aus Nd(η3-C3H5)3 · dioxan und methylaluminoxan (MAO) sowie Hexaisobutylaluminoxan (HIBAO)

The activation of the tris(allyl)neodymium complex Nd(η³-C₃H₅)₃ · dioxane with alkylaluminoxanes (MAO or HIBAO) results in highly selective catalysts for the 1,4-cis-polymerization of butadiene (cis-selectivity up to 80%). Under standard conditions (50°C, toluene), the turnover frequency (TOF) of the catalyst/MAO system amounts to 10–15000 mol butadiene/(mol Nd · h). Molecular weight determinations indicate the formation of only one polymer chain per neodymium center as in a living polymerization reaction, and for the catalyst/HIBAO system the rate law r_p = k_p [Nd][C₄H₆] with k_p = 8,7 · 10^?2 mol/(L · s) (at 25°C) has been derived. As the catalytically active species, a cationic monobutenyl neodymium(III) complex is discussed, which is stabilized through coordinative interaction with the counter anion as well as the growing polybutadiene chain. This cationic complex reacts under insertion with butadiene in a bimolecular fashion.     

Serum antibody in Actinobacillus actinomycetemcomitans-infected patients with periodontal disease

This study was designed to (i) delineate the characteristics of serum antibody responses to Actinobacillus actinomycetemcomitans in patients with periodontitis who are infected with A. actinomycetemcomitans; irrespective of disease classification; (ii) assess the relationship of the elevated antibody levels to colonization of the oral cavity by A. actinomycetemcomitans; and (iii) describe the serotype distribution of A. actinomycetemcomitans and antibodies to the microorganism in infected patients with various clinical classifications. To compare the levels of various isotype-specific antibodies to the different antigens, studies were performed that allowed quantitation of each isotype-specific antibody in a human reference standard. By using this reference standard, it was shown that the levels of immunoglobulin G (IgG), IgM, and IgA responses to A. actinomycetemcomitans were similar among the infected patients, irrespective of disease classification. Also, we demonstrated that the serum antibody response to serotype b was quantitatively greater in all isotypes. Our findings indicate that b was the most frequent A. actinomycetemcomitans serotype detected in the patients and appears to be capable of initiating a substantial serum IgG antibody response that may contain cross-reactive antibodies to other serotypes of A. actinomycetemcomitans. Generally, in cases in which the response to a single serotype was elevated, only that type of A. actinomycetemcomitans was detected in the plaque. Individuals exhibiting elevated antibodies to multiple serotypes were most consistently colonized by the serotype b microorganism. This study represents the first report detailing the distribution of IgG subclass antibodies to A. actinomycetemcomitans in periodontal disease. The results demonstrated that the primary responses of patients with periodontitis to A. actinomycetemcomitans were of the IgG1 and IgG3 subclasses, which is consistent with elicited responses to protein antigens. In contrast, the primary subclass response in normal subjects was limited to the IgG2 subclass and may represent broader cross-reactivity to polysaccharide antigens-lipopolysaccharide from the bacteria.     

Hepatitis B vaccination of high-risk individuals in the canton of Zurich

In an effort to vaccinate as many high-risk individuals as possible against hepatitis B, 10,484 persons received a total of 27,818 injections of H-B-Vax (Merck Sharp & Dohme) or HEVAC B (Sanofi/Pasteur) between January 1982 and January 1983. They represented 1.1 % of the total population of the canton of Zurich including approximately 70% of all medical and dental personnel, a great proportion of eligible high-risk patients and contacts of HBs Ag carriers, but not more than 10% of drug addicts and promiscuous homosexuals. Twelve to 17 % of the vaccine injections were accompanied by side effects which were benign in nature and transitory. Six vaccinated individuals developed hepatitis B, all within 60 days after the first vaccine dose. One hundred and seventy-seven cases of hepatitis B were recorded in 1982, 109 in the first half of the year and 68 in the second half. It was concluded that the vaccination campaign provided protection for medical and dental personnel. There was still no conclusive evidence of a vaccine-related drop in the incidence of hepatitis B in other high-risk groups vaccinated or — as a secondary effect — in other non-vaccinated populations.     

Cytokine interactions in experimental cutaneous leishmaniasis. II. Endogenous tumor necrosis factor-alpha production by macrophages is induced by the synergistic action of interferon (IFN)-gamma and interleukin (IL) 4 and accounts for the antiparasitic effect mediated by IFN-gamma and IL 4

Tumor necrosis factor-alpha (TNF-alpha) strongly activates murine peritoneal macrophages (M phi) for killing of amastigotes from Leishmania major in the presence of low amounts of interferon-gamma (IFN-gamma). Recently, we found that IFN-gamma and interleukin 4 (IL 4) also synergistically enhance the antileishmanial potential of M phi. In this report, evidence is provided that the synergism of IFN-gamma and IL 4 is based on the ability of the lymphokines to induce the endogenous production of TNF-alpha. First, both IFN-gamma and IL 4 as single agents and in combination were potent inducers of TNF-alpha production by M phi infected with L. major amastigotes. Second, the synergistic effect of IFN-gamma and IL 4 on parasite killing by M phi strongly correlated with their synergistic effect on the release of TNF-alpha. Third, the IFN-gamma/IL 4-mediated parasite elimination was completely abrogated not only in the presence of antibodies to IFN-gamma and IL 4, but also with an antibody specific for TNF-alpha. Consistent with the conclusion that endogenously produced TNF-alpha accounts for the synergism of IL 4 with IFN-gamma is the finding that N omega-monomethyl-L-arginine, an inhibitor of the L-arginine-dependent generation of microbicidal nitrogen intermediates, totally blocked the M phi activation induced by IFN-gamma combined with IL 4 as well as by IFN-gamma combined with TNF-alpha. These results underline the complex interplay of cytokines derived from lymphocytes and M phi and the role of TNF-alpha as pivotal factor for the induction of antileishmanial effector functions.