CD80 and CD86 expression on LPS-stimulated monocytes and the effect of CD80 and CD86 blockade on IL-4 and IFN-gamma production in nonatopic bronchial asthma

CD80 and CD86 seem to play an important role in the allergen-induced secretion of interleukin (IL)-5 and IL-13. Up to now, the expressions of CD80 (B7.1) and CD86 (B7.2) on monocytes and the kinetics of the expression of these molecules on lipopolysaccharide-stimulated monocytes in nonatopic asthma have not been defined. Using monoclonal antibodies, we have compared the expressions of CD80 (B7.1) and CD86 (B7.2) on the monocytes of healthy persons and nonatopic asthmatic patients. We have also assessed the effect of CD80 and CD86 inactivation on IL-4 and interferon (IFN)-gamma production in nonatopic asthmatics and healthy subjects. We found that a low expression of CD80 (1.64 +/- 0.65 vs. 3.53 +/- 1.43%) and a moderate expression of CD86 (41.25 +/- 13.4 vs. 49.46 +/- 11.49%) on the studied monocytes were characteristic for asthma. In nonatopic asthma patients inactivation of CD80 or CD86 blockade significantly reduced IFN-gamma production by T lymphocytes (p < 0.02; p < 0.03). In both the studied groups, anti-CD80 antibodies did not diminish T lymphocyte production of IL-4. However, anti-CD86 antibodies significantly (p < 0.04) reduced the IL-4 concentration in culture supernatants. Our results confirm that both the CD80 and CD86 molecules play an important role in the maintenance and amplification of the inflammatory process. It suggests that in the inflammatory process that occurs in nonatopic bronchial asthma, Th1 as well as Th2 lymphocytes are equally important.     

Cationic polymerization of 1-azabicyclo[4.2.0]octane, 1 alkylation

The rate constants of the reaction of 1-azabicyclo[4.2.0]octane ( 1 ) with different alkyl esters or halides were measured using ¹H NMR and UV spectroscopy as well as conductometric methods. The reactivities of the alkylating agents were found to decrease with increasing nucleophilicity of the derived anions (CF₃SO^?₃ > I^? > Br^? > picryl^? > Cl^?). Reactivities of all ethyl derivatives, except ethyl chloride, are higher than the reactivity of the 1-alkyl-1-azoniabicyclo[4.2.0]octane cation ( 2 ), which means that for these compounds the rate constant of initiation is higher than that of propagation. The reactions proceed much slower in methanol than in nitrobenzene due to the strong donor-acceptor interactions between methanol and 1 . Attempts to observe covalent active centers directly by NMR spectroscopy in the polymerization mixture or to detect them kinetically, were unsuccessfull. The reactivity of ethyl triflate, modelling the hypothetical active center, was found to be 2.10⁴ times higher than the reactivity of ions 2 . This is ascribed to the high strength of the bond in the cation 2 , not sufficiently compensated by the strain of the four-membered ring.     

Development of a simple method for rapid isolation of polymorphonuclear leukocytes from human blood

Polymorphonuclear leukocytes (PMNs; commonly known as neutrophils) play essential roles in innate immunity and inflammation. Although there are standardized methods for the isolation of human neutrophils, they are time consuming and demand considerable technical expertise, making them unfeasible for many clinical applications. Here, we describe a simple and time-efficient technique for the isolation of human neutrophils, which adapts a readily available commercial cell preparation tube (CPT) currently in use for isolation of peripheral blood mononuclear cells (PBMC) and plasma and is now adapted to also yield neutrophils. The total time required for neutrophil isolation was less than 1 hr. Neutrophils isolated by this method were highly purified (> or =97%) as assessed by surface expression of the neutrophil specific marker, CD66b. Neutrophils isolated by this method were functional as demonstrated by their ability to secrete interleukin-1 receptor antagonist (IL-1RA). Neutrophils isolated using this new technique secreted significant amounts of soluble IL-1RA (929.3+/-197 pg/10(6)cells/mL) in response to lipopolysaccharide (LPS). Use of this adapted CPT method allows simultaneous isolation of functional human neutrophils as well as PBMC and plasma. Adoption of this new method will allow the conduct of different neutrophil assays at any clinical site without requiring trained laboratory personnel or a large staff time commitment.     

Distribution of ganglionic sympathetic neurons supplying the subcutaneous,perirenal and mesentery fat tissue depots in the pig

Previous morphological studies revealed that the adipose tissue is innervated by adrenergic nerve fibers. Furthermore, physiological studies showed that the metabolism of adipose tissue is controlled by the adrenergic component of the nervous system. However, nothing is known on the sources of innervation of different fat tissue depots. Therefore, we decided to study the distribution of ganglionic sympathetic neurons innervating adipose tissue in the pig by means of a retrograde tracing method. We used 9 male and 9 female pigs of approximately 50 kg body weight. The retrograde tracer, Fast Blue (FB), was injected into the subcutaneous, perirenal and mesentery fat tissue depots. Results of the present study showed that numerous centers of the sympathetic nervous system innervate adipose tissue in the pig. FB+ neurons projecting to the subcutaneous fat tissue were placed in the thoraco-lumbar region of the sympathetic chain ganglia (SChG). However, neurons supplying perirenal and mesentery fat tissue depots were found in both the SChG and prevertebral ganglia (PVG). We conclude that different adipose tissue depots (subcutaneous, perirenal and mesentery) have different sources of innervation and that there is no significant difference in the distribution of neurons innervating adipose tissue in male and female pigs.     

Evidence that orexins A and B stimulate insulin secretion from rat pancreatic islets via both receptor subtypes

Orexins are recently identified neuropeptides that appear to play a role in the regulation of energy homeostasis and arousal. They bind to and activate two closely related G protein-coupled receptors (OXR1 and OXR2), previously described as orphans. In this study we examined involvement of orexins in regulation of insulin secretion from rat pancreatic islets utilizing an in situ perfused pancreas and isolated pancreatic islet models. By means of RT-PCR we found that both OXR1 and OXR2 are expressed in rat pancreatic islets. Furthermore, the expression levels of OXR1 were higher than OXR2. In both experimental models applied, orexins A and B (1, 10 and 100 nmol/l) concentration dependently stimulated insulin secretion at two different glucose concentrations (6.66 or 26.4 mmol/l), with orexin A being more potent than orexin B. This study demonstrates that orexins A and B modulate insulin secretion in vitro.     

Case report: Role of hepatitis E virus in the etiology of community-acquired non-A,non-B hepatitis in greece

The aim of this study was to determine the frequency of hepatitis E virus (HEV) infection in a population of Greek adults with community-acquired (sporadic) non-A, non-B hepatitis found to be seronegative for antibodies to hepatitis C virus (anti-HCV). All patients admitted to the Liver Unit of Western Attica General Hospital and diagnosed as having acute community-acquired non-A, non-B hepatitis between February, 1986, and May, 1990, were enrolled in follow up studies (n = 66). Nineteen patients with HCV infection and 11 patients with acute non-A, non-B, non-C hepatitis that progressed to chronicity were excluded. Convalescent sera were tested for antibody to HEV (anti-HEV) by a fluorescent antibody blocking assay in 33 of 36 eligible patients. One of the 33 (3%) patients was found to be positive for anti-HEV. Anti-HEV testing of all 20 available serum specimens from this patient showed evidence of anti-HEV seroconversion at the fourth week after the onset of hepatitis. The patient had not travelled abroad or within Greece or had not had apparent contact with people from foreign countries for the previous 3 months. These data show that HEV infection is not a major cause of community-acquired non-A, non-B hepatitis in Greece. However, the reported case of HEV hepatitis suggests that HEV may retain a low endemicity in Greece. More extensive seroprevalence studies are needed for an accurate estimation of the extent of HEV infection in the southeastern European countries. © 1994 Wiiey-Liss, Inc.     

Crystalline and disordered state of poly(dihexylsilylene) copolymers

A systematic comparison of random copolymers, derived from poly(dihexylsilylene) (PDHS) by incorporation of monomeric units with shorter unbranched alkyl side chains, has been carried out based on calorimetry, variable temperature UV spectroscopy, and ²⁹Si MAS (magic angle spinning) solid state NMR investigations. Also, hexylmethylsilylene units and branched monomers have been copolymerized. Up to 10% comonomer with shorter linear side chains (i. e., pentyl to propyl) could be incorporated into PDHS without impeding the all-trans order of the crystalline phase. In this case, the UV absorption maximum of the crystalline low-temperature phase was affected only slightly according to the length and fraction of the comonomer side chains. A less ordered crystal structure (λ_max = 345–355 nm) was observed when the content of comonomers with shorter side chains was about 20%. Yet, all these materials form conformationally disordered mesophases. A clear disordering transition and corresponding thermochromism was not observed any more when 50% of propyl side chains were incorporated. The order of the crystalline and the mesophase is also strongly perturbed if only a small fraction (4%) of the side chains are branched at C².     

Immunohistological analysis of the lymphoid infiltrate in cutaneous malignant melanomas

Summary The immunological phenotypes of the lymphoid cells in 39 cutaneous malignant melanomas have been investigated by staining cryostat sections with a panel of 20 monoclonal antibodies against lymphoid cells and their subsets. Staining was performed by the alkaline phosphatase: anti-alkaline phosphatase (APAAP) method in which the substrate label (red) is easily distinguishable from melanin. The lymphoid infiltrates had an essentially identical composition in all cases, consisting of T-lymphocytes associated with both Langerhans cells and HLA-DR-positive tissue macrophages. B-lymphocytes and natural killer cells were either absent or only present in low numbers. The ratio between T8 (suppressor/cytotoxic) and T4 (helper/inducer) lymphocytes varied and showed no correlation with melanoma subtype, level of invasion or magnitude of lymphocytic response. Examination for markers associated with T-cell activation and/or with cell proliferation revealed that all lesions contained HLA-DR-positive T-lymphocytes, whereas expression of the transferrin receptor and the interleukin-2 receptor (Tac-antigen) occurred mainly in melanomas with a significant inflammatory infiltrate. These data support the concept that malignant melanomas are capable of evoking autologous T-cell immune reactions.