Reconstitution of a functional interleukin (IL)-7 receptor demonstrates that the IL-2 receptor γ chain is required for IL-7 signal transduction

The interleukin (IL)-2 receptor γ chain has recently been shown to be a component of the IL-7 and IL-4 receptors. Using a transient transfection assay and the trans-activation of reporter gene constructs which are under the control of cytokine-responsive promoter elements, we have studied signal transduction through the IL-7 receptor (IL-7R). The reporter gene expression was not stimulated by receptors that contained the cytoplasmic domain of the IL-7R, either as intact IL-7R or as part of a chimeric receptor. However, co-expression of the IL-7R with the IL-2 receptor γ chain was able to stimulate gene activation. For maximal stimulation the intact cytoplasmic domains of each chain was required.     

No evidence for involvement of the calpain-10 gene 'high-risk' haplotype combination for non-insulin-dependent diabetes mellitus in early onset obesity

In light of evidence of linkage of obesity to chromosome 2q31-q37, we hypothesized that the calpain-10 gene 'high-risk' haplotype combination for non-insulin-dependent diabetes mellitus (NIDDM) is involved in early onset obesity. We screened the NIDDM 'high-risk'-haplotype combination formed by the alleles 112 and 121 of the polymorphisms UCSNP-43, -19, and -63 in 166 families consisting of an extremely obese child or adolescent (mean BMI percentile: 99.3+/-1.38), one or more obese sibs (mean BMI percentile: 97.42+/-2.88), and both of their parents. Genotyping for three calpain-10 gene polymorphisms was performed by polymerase chain reaction (PCR) with (a) length polymorphism detection (UCSNP-19) or (b) allele-specific PCR (UCSNP-43 and -63). To allow for correct haplotype assignment all individuals were additionally genotyped for two microsatellite markers (D2S125 and D2S2338). We followed a hierarchical test procedure. As the first step, model-free linkage analysis was performed using maximum likelihood binomial statistics. The second stage consisted of a one-sided asymptotic pedigree disequilibrium test for the UCSNP-43 and on an exploratory level for the other SNP-markers and all haplotypes formed by the three SNPs. The final stage investigated the reported haplotype combination. We failed to detect an initial linkage of obesity to this region (LOD score <0.4). All subsequent exploratory analyses were negative. Our analysis of the relationship between the NIDDM 'high-risk' haplotype combination and extreme early onset obesity revealed no evidence for linkage and association.     

Adsorption/desorption phenomena on pure and Teflon AF-coated titania surfaces studied by dynamic contact angle analysis

As a result of inflammatory processes, plaque formation on dental titanium implants often leads to clinically pathogenic situations. This special biofilm formation on (bio)materials in contact with saliva is initiated by ionic and protein interactions. In this interfacial process, albumin becomes a main constituent of dental pellicle. Interfacial reactions change the surface characteristics. They determine the following steps of macromolecular adsorption and bacterial adhesion. This work focuses on the dynamic contact angle analysis (DCA), which is a tool for online measurements of dynamic changes of wettability without disturbing the interface during detection. Repeatability of the DCA method has been assessed according to the Bland and Altman method. The kinetics and equilibrium data of shifts in the wetting tension hysteresis indicate ionic influences at the titanium/bovine serum albumin (BSA) interface: the Ca-mediated increase of the BSA adsorption on titanium and the adsorption maximum at the isoelectric point (IEP) of BSA. Ti was surface modified by Teflon AF polymeric coatings. The result of the assessment gives reason to consider Teflon AF as a reference material for DCA repeatability studies. This surface modification caused drastic changes in the dynamic interfacial reactions. Shifts in the wetting tensions during DCA adsorption-desorption experiments clearly demonstrated the partially irreversible adsorption of BSA on Teflon AF. In contrast, reversible adsorption behavior was detected on pure Ti surfaces. These findings strengthen the hypothesis that the analysis of dynamic changes in wetting tension and wetting tension hysteresis is a sensitive analytical method for the detection of dynamic interfacial changes at biomaterial/biosystem interfaces during the initial steps of biofilm formation.     

Characterization of a monoclonal anti-Bw4 antibody (Tü109): Evidence for similar epitopes on the Bw4 and Bw6 antigens

The production and serologic, as well as immunochemical properties of a cytotoxic murine IgG monoclonal antibody (Tü109) that precipitates HLA-class I molecules, are described. In the microcytotoxicity assay Tü109 supernatant was demonstrated on a panel of 424 HLA-ABC, -DR, -DQ, -MT typed normal Caucasian blood donors to define an epitope on HLA-B locus molecules in great association with the supertypic specificity Bw4. Reactivity of supernatant showed MHC linked inheritance of the Tü109 determinant and discriminated the HLA-Bw4/Bw6 associated HLA-B locus split antigens. Weak or lack of binding on lymphocytes from some HLA-Bw4 heterozygous individuals, particularly typing for HLA-Bw44, appeared to be due to qualitative and/or quantitative variations of HLA-B locus molecules on the cell surface. With Tü109 ascites fluid, however, extra-reactivity on all HLA-Bw6⁺ cells was demonstrated. Preferential binding of supernatant to HLA-Bw4, but reactivity of ascites fluid with HLA-Bw6⁺ molecules in addition, was furthermore confirmed by IEF analysis of antigens immunoprecipitated with Tü109 from cell lysates. Thus the antibody may help to analyze the evolutionary relationship of the diallelic specificities Bw4 and Bw6.     

Emergence and persistence of multiple antiviral-resistant CMV strains in a highly immunocompromised child.

BACKGROUND: The emergence of human cytomegalovirus (CMV) antiviral resistance plays a significant role in disease progression in immunocompromised patients who have received antiviral therapy. OBJECTIVES: To determine the pattern of antiviral-resistant CMV strains in a highly immunocompromised child. STUDY DESIGN: Retrospective specimens of blood and urine were analysed using PCR-sequencing to identify antiviral-resistant CMV strains containing UL97 or UL54 mutations. RESULTS: CMV strains resistant to antiviral agents contributed to disease in a bone marrow transplant recipient with X-linked severe combined immunodeficiency (SCID) treated with ganciclovir (GCV) and foscarnet (FOS). Retrospective analyses detected GCV-resistant CMV (L595S) in a specimen taken after disease progression. This GCV-resistant CMV strain persisted for 1 year, after which time it was no longer detected even though the patient continued to receive GCV. A FOS-resistant strain (T700A) then emerged even though no FOS had been administered in the preceding year. CONCLUSION: The detection of antiviral-resistant CMV did not follow the patterns found in other patients tested for antiviral resistance, including emergence of a FOS-resistant strain in the absence of antiviral-selective pressure. These findings indicate the patient's underlying immunosuppressive condition should be considered for diagnosis and management of resistant CMV.     

Pancreatic enzyme secretion in the conscious rat

1. A method for collecting duodenal juice and gastric content separately, in conscious rats, is described. Metal cannulas were implanted into the stomach fundus. For the main experiment a double lumen tube was inserted through the cannula via the pylorus into the duodenum. 2. The following secretion patterns were observed: a) In the resting state there was a constant flow rate of duodenal volume, bicarbonate, trypsin and amylase. b) Cholinergic stimuli were capable of increasing enzyme secretion as much as fourfold for a period of 30 to 40 min when administered as a single subcutaneous injection. This effect was annulled by atropine. c) Secretin and cholecystokinin-pancreozymin given together in a single injection s.c. or i.v., elicited a similarly strong response. d) Identical ranges of the secretion maxima were found with a tendency to decrease after the first hour, when the hormones were infused either s.c. or i.v. e) Doses from 0.5 to 25 U/100 g b.w. /hr showed identical responses. Doses below 0.2 U/100 g/hr were without effect. 3. Narcosis (pentobarbital) inhibited markedly the resting and stimulated enzyme secretion. 4. The method is suitable for examination of physiological and pharmacological effects on resting and stimulated enzyme secretion of the rat pancreas.     

The influence of simvastatin alone or in combination with gemfibrozil on plasma lipids and lipoproteins in patients with type III hyperlipoproteinemia

Summary Nineteen adult patients with type III hyperlipoproteinemia (HLP) and homozygosity for apolipoprotein (apo) E2 were treated with the 3-hydroxy-3-methyl glutaryl coenzyme A (HMG CoA) reductase inhibitor simvastatin (20 or 40 mg per day) alone or in combination with the fibrate derivative gemfibrozil (450 mg per day) during a 30-week outpatient study. With the 20-mg dose (n = 19) the mean plasma cholesterol level decreased from 13.24±8.04 8.04 at baseline to 8.04±4.19 mmol/l (mean reduction 39.3%; P<0.05), and the mean plasma triglyceride level decreased from 13.47±19.22 to 7.84±7.71 mmol/l (–41.8%; NS); this was due to a decrease in very low density lipoprotein (VLDL) cholesterol from 8.95±8.64 to 4.94±4.24mmo1/l (–44.8%; NS), a decrease in low density lipoprotein (LDL) cholesterol from 3.54±0.93to 2.25 ± 0.59 mmol/l (–36.5%; P<0.01), and an increase in high density lipoprotein (HDL) cholesterol from 0.72±0.28 to 0.85±0.34 (+18.1%; NS). Thirteen patients were treated with 40 mg simvastatin per day. Under this regimen there was a further significant decrease in LDL cholesterol from 2.33±0.62 to 1.81±0.49 mmol/l (–22.3%; P<0.01). In six patients who remained hyperlipidemic on monotherapy combination drug therapy with simvastatin (40 mg per day) and gemfibrozil (450 mg per day) was given. Compared to simvastatin alone the addition of gemfibrozil further lowered plasma concentrations of total cholesterol by 14.9%, VLDL cholesterol by 23.5%, and triglycerides by 17.1%, although this was not statistically significant. No patient was discontinued from single or combination drug therapy, and no severe clinical or biochemical side effects were observed. The results of this study demonstrate the usefulness of simvastatin in the therapy of type III HLP and indicate that in individual patients who remain hyperlipidemic on monotherapy combination drug therapy with both of these drugs is effective in further reducing plasma concentrations of total cholesterol, VLDL cholesterol, and triglycerides. Although no patient in this investigation developed myopathy or rhabdomyolysis, combined fibrate-HMG CoA reductase inhibitor treatment should be considered only for severe forms of hyperlipidemia and for patients who do not respond sufficiently to mon-therapy of any of these drugs.Abbreviations Apo Apolipoprotein - CPK creatine phosphokinase - GGT gamma-glutamyl transpeptidase - HDL high density lipoproteins - HLP hyperlipoproteinemia - HMG CoA 3-hydroxy-3-methyl glutaryl coenzyme A - IDL intermediate density lipoproteins - LDL low density lipoproteins - TG triglycerides - VLDL very low density lipoproteins     

The value of virus serology in epidemiological studies of acute otitis media in children.

BACKGROUND: Acute otitis media (AOM) is a major health problem in young children. There is a general conception that AOM is a bacterial disease but with the availability of sensitive diagnostic methods, it has gradually become evident that viruses play an important role in the pathogenesis of AOM. Paired blood samples are seldom taken from infants although valuable information could be obtained by serological methods. During the recent Finnish Otitis Media (FinOM) Cohort Study, in addition to nasopharyngeal aspirates (NPA) and middle ear fluids (MEF), paired acute and convalescent serum samples were collected from children with AOM. OBJECTIVES: To establish the diagnostic value of serological methods in etiological and epidemiological studies of AOM. STUDY DESIGN: A complete set of NPA, MEF, and paired sera was collected during 447 events of AOM experienced by 179 children between 2 months and 2 years of age. Antigens of respiratory syncytial virus (RSV), adenoviruses, influenza A and B, and parainfluenza types 1-3 in NPAs and MEFs were detected by time-resolved fluoroimmunoassay (TR-FIA), and antibody titers were determined by complement fixation test (CFT) or by enzyme immunoassay. RESULTS: A total of 163 virus-positive events were identified. Of those, only 34 were positive by TR-FIA and by serology. From 48 events a positive result was obtained only by TR-FIA and from 81 only by serology. CONCLUSION: Although serological methods are usually of little use in clinical practice, epidemiological studies clearly gain value if serology is included. The number of virus-positive findings dramatically increased by including serological tests in the diagnostic work-up of these AOM events.     

CD69-null mice protected from arthritis induced with anti-type II collagen antibodies

CD69, known as an early activation marker antigen on T and B cells, is also expressed on platelets and activated neutrophils, suggesting certain roles in inflammatory diseases. In order to address the role of CD69 in the pathogenesis of arthritis, we established CD69-null mice. CD69-null mice displayed a markedly attenuated arthritic inflammatory response when injected with anti-type II collagen antibodies. Cell transfer experiments with neutrophils, but not T cells or spleen cells, from wild-type mice into CD69-null mice restored the induction of arthritis. These results indicate a critical role for CD69 in neutrophil function in arthritis induction during the effector phase. Thus, CD69 would be a possible therapeutic target for arthritis in human patients.