Reentrant phase behavior in systems with density-induced tunneling.

We show that correlations in strongly interacting many-particle systems can create quantum decoherence, leading to a mechanism of dissipation that does not rely on an external source. Using analytical methods, we study a bosonic many body system in two dimensions, with extended interactions between particles. We show that, as expected, the system can be driven out of a coherent state. Surprisingly, when the interaction strength is sufficiently large, the system reenters the superfluid phase even after coherence is lost. The breakdown of quantum coherence is a certainty, but interpreting the process correctly relies on understanding and preserving the nature of the coupling between the constituents of the many particle system. The methods used provide a natural cutoff point at the critical temperature, where superfluidity breaks down.

Degradation of PCBs in dry fermented sausages during drying/ripening.

The effects of several commercial meat starter cultures on degradation of polychlorinated biphenyls (PCBs) in dry fermented sausages over 28days of drying/ripening were investigated. The sausage batter was prepared according to a classic recipe and spiked with a standard solution of a PCB congener mixture. With addition of different commercial meat starter cultures, five experimental groups were prepared: no further addition; and separate addition of each of four starter cultures: Texel DCM-1, Texel LM-30, Biostar Sprint, and SM-181. Samples were taken at the beginning of fermentation (zero time), and after 4, 7, 14, 21 and 28days. PCB residues were extracted with hexane. The PCB contents were determined using gas chromatography-mass spectrometry. The PCB levels were reduced in all of the experimental groups tested, where addition of starter culture Biostar Sprint (Lactobacillus sakei, Staphylococcus carnosus, Staphylococcus xylosus) showed the highest PCB degradation rates.

Degradation of PCBs in a frankfurter-type meat emulsion: effects of a meat starter, its proteins extract and thermal treatments.

The degradation of a series of polychlorinated biphenyl (PCB) congeners (PCBs 10, 28, 52, 138, 153, 180) in meat emulsions of a frankfurter type was investigated. With a pool of these PCBs added to the meat emulsion, three initial experimental groups were used: no further addition, or plus a commercial meat starter (containing Staphylococcus xylosus and Staphylococcus carnosus), or plus the protein extract from this commercial meat starter. Prior to further treatments, these samples were incubated for 72 h at 4°C. These meat emulsions were then either left at 4 °C (raw) or thermally treated to two different internal temperatures: 78 and 100 °C. Following cooling and a further 24 h at 4 °C, all of the samples were extracted with hexane to recover the PCB residues, following method EPA 608, with some modifications. The addition into the meat emulsion of the commercial meat starter and the proteins extract both affected PCB degradation. Also, the effects of thermal treatment at both temperatures saw the PCB contents successfully reduced, as compared to the raw meat emulsions.

Cholesterol concentration and fatty acid profile of red deer (Cervus elaphus) meat.

The effects of gender and age on intramuscular fat (IMF) levels, cholesterol concentration, and fatty acid composition were investigated in the semitendinosus (ST) and triceps brachii (TB) muscles of feral red deer (Cervus elaphus). Six stags of >2years of age, four hinds of 1year, and six calves of 6months were shot in Slovenia. Generally, all parameters measured were influenced by interaction of muscle and treatment group (hinds, stags and calves) at the 5% level or less. In ST muscle, the IMF levels were highest for hinds. In the TB muscle, cholesterol was lower for stags than for hinds and calves. The saturated fatty acids were the highest for stags and the mono-unsaturated fatty acids for hinds. The polyunsaturated fatty acids (PUFAs) were the highest for calves and lowest for hinds. The n-3 PUFAs were the lowest for hinds. In both muscles, the calves had higher n-6 PUFAs than stags and hinds. Only the ST muscle of the hinds contained >1% (1.44%) of the conjugated linoleic acid isomer 18:2cis-9,trans-11, while in the TB of hinds and calves this fatty acid was higher than with stags. We conclude that gender and age of feral red deer influence the IMF content, the cholesterol concentration, and the fatty acid composition of the meat.

Non-invasive measurement of vagus activity in the brainstem - a methodological progress towards earlier diagnosis of dementias?

In Alzheimer's disease (AD), mild functional disturbances should precede gross structural damage and even more clinical symptoms, possibly by decades. Moreover, alterations in the brainstem are supposed to occur earlier as cortical affections. Based on these considerations, we developed a new method aiming at the measurement of vagal brainstem functioning by means of evoked potentials after electrical stimulation of the cutaneous representation of the vagus nerve in the external auditory channel. In the current study, a first sample of patients with Alzheimer's disease (n = 7) and mild cognitive impairment (n = 3) were investigated (6m, 4f, range from 57 to 78 y, mean age 68.6 years). Vagus somatosensory evoked potentials (VSEP) were characterized by significantly longer latencies as compared to healthy age- and gender-matched controls (p < 0.05). Future large scale studies - also including preclinical stages of AD - have to assess the value of this non-invasive, fast and cheap method in the early diagnosis of neurodegenerative disorders.

Interferon beta-1b modulates serum sVCAM-1 levels in primary progressive multiple sclerosis.

Endothelial activation is a key feature of multiple sclerosis (MS) pathogenesis. It is modulated by interferon beta-1b (IFNB-1b) treatment in relapsing-remitting MS (RRMS) patients. This particular pharmacodynamic effect still has to be proven in primary progressive MS (PPMS). In the current study, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) and sE-selectin were analyzed longitudinally in 18 PPMS patients before, during and after 12 months of treatment with IFNB-1b. During drug therapy there was a significant early and sustained increase of sVCAM-1 (overall P < 0.0001). Flu-like symptoms induced by IFNB-1b and also concomitant infections were associated with higher sVCAM-1 levels. Neutralizing antibodies to IFNB-1b were associated with lower sVCAM-1 levels. In conclusion, IFNB-1b modulates the adhesion cascade in patients with PPMS in a similar way it does in RRMS. Nevertheless, a clinical effect of IFNB in PPMS still has to be proven in a randomized controlled clinical trial.

Antigen-driven lymphocyte recruitment to the lung is diminished in the absence of urokinase-type plasminogen activator (uPA) receptor, but is independent of uPA.

The requirement for urokinase plasminogen activator (uPA) and uPA receptor (uPAR) in T lymphocyte migration is unknown. uPA(-/-) mice have fewer pulmonary lymphocytes in response to certain infections, but its unknown whether this is due to diminished recruitment. Primed, recipient mice were IT inoculated with Ag. Three days later, fluorescently labeled lymphoblasts from background-matched control wild-type (WT), uPA(-/-), or uPAR(-/-) donor mice were injected i.v., and their recruitment was determined. Approximately twice the number of uPA(-/-) compared with WT lymphoblasts were recruited to the lungs of WT recipients. This difference was eliminated when uPA(-/-) and WT lymphoblasts were injected into uPA(-/-) recipients. Thus, the reduced number of lung lymphocytes in infected uPA(-/-) mice is not due to reduced recruitment. However, uPAR is critically involved in recruitment. Markedly fewer uPAR(-/-) compared with WT lymphoblasts were recruited to the lung. These findings suggest that uPAR may be a novel target for immune modulation in T lymphocyte-mediated disorders.

A comparison of fluorescamine and naphthalene-2,3-dicarboxaldehyde fluorogenic reagents for microplate-based detection of amino acids.

The use of appropriate fluorometric derivatization procedures is of considerable importance for accurate determination of amino acids in biological samples and in metal-assisted peptide hydrolysis reactions. It is especially critical for the relative fluorescence intensities (RFI) of equal amounts of amino acids to be as similar as possible. While fluorescamine and naphthalene-2,3-dicarboxaldehyde (NDA) have proven to be excellent fluorogenic reagents for amino acid detection, the effects of various factors such as organic solvent, buffer, and pH have never been rigorously evaluated with respect to normalizing the relative fluorescence intensities of individual amino acids. To this end, here we describe optimized fluorescamine and NDA derivatization reactions that enhance the accuracy of microplate-based detection of amino acids. For both fluorescamine and NDA, we have shown that the RFI values of 16 of 19 amino acids are greater than 70%. Although determination of tryptophan is problematic, this difficulty is overcome by the addition of beta-cyclodextrin to the NDA reaction. In principle, the optimized fluorescamine and NDA microplate procedures reported here can be utilized as complementary techniques for the detection of 19 of 20 naturally occurring amino acids.

Speciation of low molecular weight Al complexes in serum of CAPD patients.

Speciation of LMW--Al complexes was performed in human serum of six continuous ambulatory peritoneal dialysis (CAPD) patients in order to investigate the individual variability in the percentage and the composition of LMW--Al species. The total concentration of Al in serum ranged from 10 to 120 ng ml(-1). The samples with high total concentration of Al were analysed directly, while those of low total Al concentration were spiked with Al(3+). Spiked and non-spiked samples (100--120 ng ml(-1) of total Al) were microultrafiltered through a membrane filter (cut-off 30,000 Da) to separate Al-transferrin from LMW-Al complexes. On an anion-exchange fast protein liquid chromatography (FPLC) column, 0.2 ml of filtrate was injected. An aqueous -- 4 mol l(-1) NH(4)NO(3) linear gradient elution was applied for 10 min to separate LMW--Al complexes. Fractions of 0.2 ml collected throughout the chromatographic run were diluted 1:1 with water and Al determined 'off line' by electrothermal atomic absorption spectrometry (ETAAS). The characterisation of LMW-Al species eluted under the chromatographic peaks was performed also by electrospray tandem mass spectrometric (ES-MS-MS) analysis. It was found experimentally that the percentage of LMW--Al species in spiked and non-spiked serum ranged from 25 to 50% (in one non-spiked sample 100%). The following LMW--Al species were separated and identified during the chromatographic run: Al-phosphate and a mixture of Al-citrate and ternary Al-citrate--phosphate complexes. It was found experimentally that the distribution of these species varied among particular patients. Similar distribution of LMW--Al species was found in spiked serum of healthy volunteers.

The uptake and speciation of various Al species in the Brassica rapa pekinensis.

An investigation was carried out on the uptake and speciation of Al species in Al tolerant Chinese cabbage (Brassica rapa L. ssp. pekinensis). Plants were exposed to 10 microg cm(-3) of Al in the chemical forms of Al3+, Al-citrate and Al-malate in a time span from 1 up to 24 h. In each experiment the nutrient solution and stem sap were analysed by a combination of FPLC ICP AES and ES MS MS techniques. Speciation analysis enabled determination of particular chemical forms of Al present in the nutrient solution or in stem sap. The results indicate that Al3+ added to the nutrient solution remained as Al3+ in the solution during the experiments, but in the roots transformation to Al-malate occurred. Al was transported from roots to the upper parts of the plant as Al-malate (70%) and Al3+ (30%). Al-citrate or Al-malate added to the nutrient solution were transferred to the upper parts of the plant without transformation of their chemical forms.

Characterization of the human T cell response against the neuronal protein synapsin in patients with multiple sclerosis.

Although multiple sclerosis (MS) is considered primarily as a demyelinating disease, neuronal damage is abundant and correlates with the neurological deficit. Therefore, we investigated the frequency and characteristics of human T cells specific for synapsin-a neuronal protein highly conserved among species. Synapsin specific T cell responses were detected at a frequency similar to that of MBP specific T cells in MS patients, one patient with acute demyelinating encephalomyelitis (ADEM) and controls. Long-term T cell lines specific for synapsin exhibited a CD3(+), CD4(+), CD8(-) phenotype and produced high amounts of tumor-necrosis-factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) after antigen specific stimulation, whereas lymphotoxin (LT), interleukin-4 (IL-4) and interleukin-10 (IL-10) were detectable in smaller quantities.

Lymphocyte-endothelial cell adhesive interactions in lung immunity: lessons from the murine response to particulate antigen.

The adhesive interaction between lymphocytes and lung endothelial cells presents an attractive arena for the development of novel therapeutic agents to modify pathologic pulmonary immune responses. The conceptual basis for choosing molecular targets to modulate this adhesive interaction derives, in large part, from results of murine experimental model systems of the pulmonary immune response. This article reviews one such model, the response of primed C57BL/6 mice to the particulate antigen sheep erythrocytes. Novel data are presented on the effect of a blocking anti-alpha(4) integrin monoclonal antibody on lung leukocyte and lymphocyte subset accumulation after intratracheal (IT) antigen challenge. Results from this model system have indicated that lymphocytes may use either the endothelial selectins or alpha(4) integrin as independent pathways to initiate recruitment into the lungs.

Tumour necrosis factor alpha mRNA expression in early multiple sclerosis lesions: correlation with demyelinating activity and oligodendrocyte pathology.

The precise role of tumour necrosis factor alpha (TNFalpha) in multiple sclerosis (MS) is still controversial. Most findings from the animal model experimental allergic encephalomyelitis have yet to be confirmed in multiple sclerosis. The aim of this study was to define the significance of TNFalpha with respect to the hallmark of MS, that is demyelination. Therefore, 78 lesion areas from diagnostic brain biopsies of 32 patients were analysed. Lesion demyelinating activity was classified by the presence of myelin degradation products in macrophages and macrophage activation markers. Non-radioactive in situ hybridisation was carried out to detect TNFalpha mRNA expressing cells. DNA fragmentation was visualised by TdT-mediated X-dUTP nick end labeling. A significantly higher number of cells expressed TNFalpha mRNA in active demyelinating lesions than in inactive or remyelinating lesions irrespective of the extent of the inflammatory infiltrate. TNFalpha mRNA expression correlated with the appearance of DNA fragmentation in T lymphocytes and oligodendrocytes within the lesions. In the periplaque white matter, expression of TNFalpha mRNA negatively correlated with oligodendrocyte numbers. These data support previous findings from animal models and in vitro experiments. Although not proving, the current study strongly suggests a pathogenic role of TNFalpha in demyelination in human multiple sclerosis and gives further support for TNFalpha-directed therapeutic strategies.

Repeated intratracheal challenge with particulate antigen modulates murine lung cytokines.

When lungs of experimental animals are repeatedly challenged with Ag, pulmonary inflammation wanes via unknown mechanisms. We hypothesized that changes in the balance of lung cytokines are responsible for immune down-regulation to repeated Ag challenge. We used intratracheal (IT) challenge of primed C57BL/6 mice with SRBC and on various days after single (1IT) or triple (3IT) challenge counted lung inflammatory cells and measured whole-lung cytokine mRNA and protein concentrations using RT-PCR and ELISA. We found that lung lymphocyte numbers and parenchymal lung inflammation decreased significantly at days 6 and 9 after final Ag challenge in 3IT mice compared with 1IT mice. Lungs of 3IT mice showed the following changes in relative mRNA expression: an earlier peak in IL-10, decreased IL-1beta, and a change from a Th2 response in 1IT mice to a Th1 response in 3IT mice (with pronounced increases in IL-12, IL-18, and IFN-gamma and decreased IL-4, IL-13, and IL-5). Similar types of changes were seen in whole-lung protein concentrations for TNF-alpha, IL-10, IL-12 p40, IFN-gamma, and IL-4. Additionally, mRNA expression of the endothelial selectins CD62E and CD62P decreased and lung lymphocyte apoptosis increased in the 3IT group. Thus, physiologic down-regulation of the pulmonary immune response to repeated Ag exposure is characterized by increased anti- and decreased proinflammatory cytokines that accompanies Th1 polarization. Similar mechanisms may act to minimize chronic lung inflammation in the majority of normal humans who do not develop progressive lung pathology when repeatedly exposed to inhaled or aspirated environmental Ags.

Effect of interferon beta on human myelin basic protein-specific T-cell lines: comparison of IFNbeta-1a and IFNbeta-1b.

The effect of interferon (IFN)beta-1a and IFNbeta-1b on human myelin basic protein-reactive T-cell lines was investigated. Both drugs inhibited proliferation and production of lymphotoxin (LT), whereas the production of interleukin-4 was not altered and interleukin-10 was induced. Comparing equal numbers of units IFNbeta-1a and -1b showed almost identical results. These in vitro data indicate that the immunomodulatory capacity of both interferons with respect to T cells paralleled their antiviral effect.

Expression and participation of eotaxin during mycobacterial (type 1) and schistosomal (type 2) antigen-elicited granuloma formation.

Eotaxin participation was analyzed during types 1 and 2 lung granuloma formation induced by embolizing Sepharose beads coupled to purified protein derivative (PPD) of Mycobacterium bovis or soluble Ags derived from Schistosoma mansoni eggs. Eotaxin was monitored by protein ELISA and semiquantitative reverse-transcriptase PCR mRNA analysis. Both types 1 and 2 granulomas released eotaxin, but levels were sixfold greater (on day 4) in the type 2 than for the type 1 or foreign body granulomas. Transcripts for eotaxin, IL-4, and CCR3 (eotaxin receptor) were also enhanced during type 2 granuloma formation. Anti-IL-4 treatment impaired eotaxin mRNA in lungs with type 2 granulomas, indicating that IL-4 promoted local eotaxin expression. In vivo, anti-eotaxin treatment caused modest reductions in the size of both types 1 and 2 lesions, with negligible effect on eosinophil recruitment. Surprisingly, anti-eotaxin treatment abrogated IFN-gamma-producing cells in regional lymph nodes during the type 1 PPD response. Lymph nodes draining both types 1 and 2 lesions showed enhanced CCR3 mRNA, but this followed the time of maximum eotaxin protein and mRNA expression. Correlative, in vitro studies revealed that graded doses of eotaxin increased IFN-gamma production from PPD-sensitive regional lymph node cultures, while monocyte-chemotactic protein-1, an important macrophage chemoattractant, had the opposite effect. These findings indicate that eotaxin expression is not limited to type 2 hypersensitivity granulomas, but also promotes IFN-gamma production during mycobacterial responses.

Synergistic immunomodulatory effects of interferon-beta1b and the phosphodiesterase inhibitor pentoxifylline in patients with relapsing-remitting multiple sclerosis.

Subcutaneous application of interferon-beta1b (IFN-beta1b) is an established therapy for patients with relapsing-remitting multiple sclerosis (RRMS), but early side effects are still a major concern. In vitro studies with myelin basic protein (MBP)-specific T-cell lines revealed a synergistic suppressive effect of IFN-beta1b and the phosphodiesterase inhibitor pentoxifylline (PTX) on proliferation and the production of tumor necrosis factor-alpha (TNF-alpha), lymphotoxin (LT), and interferon-gamma (IFN-gamma). In an initial, open labeled prospective trial, the cytokine messenger RNA (mRNA) expression of blood mononuclear cells from MS patients, receiving either IFN-beta1b alone or in combination with oral PTX, was determined by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Patients treated with IFN-beta1b alone reported more side effects during the first 3 months of treatment and had upregulated TNF-alpha as well as IFN-gamma mRNA expression during the first month, which was not detected in patients receiving both drugs. A synergistic effect of both drugs was observed on the upregulation of interleukin (IL)-10 mRNA, which was accompanied by an increase in IL-10 serum levels. Both in vitro and in vivo data suggest that co-treatment of IFN-beta1b with PTX is a promising approach to correct the disturbed cytokine balance in MS patients.

Behavioral analysis of Drosophila mutants displaying abnormal male courtship.

We describe six recessive autosomal male sterile mutations in Drosophila, generated by mobilization of single P-elements, exhibiting abnormal male courtship behavior. Detailed analysis of courtship behavior elicited by virgin wild type females indicated that five of the six mutants are affected in the early steps of courtship. The sixth mutant is blocked at the step of attempted copulation which occurs later in the courtship sequence. All of the mutants have normal olfactory responses and normal locomotor activity. No defect in the visual modality has been observed for the five mutants affected in the initiation of courtship. The mutant blocked at attempted copulation lacks the 'on' and 'off' transients, but this appears to be due to genetic background rather than the mutation itself. Abnormal spermatogenesis was observed in five of the mutants. Spermatogenic defects vary and include lesions in the proliferation of the germline, in meiosis, and in the differentiation and maturation of the spermatids into motile sperm.