Laser doppler flowmetry in combined needle acupuncture and moxibustion: a pilot study in healthy adults

Laser Doppler flowmetry (LDF) (DRT 4/Moor Instruments Ltd, Devon, UK) was used in this pilot study for monitoring the effects of an invariable acupuncture pattern on microcirculation of the skin before, during, and after combined needle acupuncture and moxibustion in 12 healthy volunteers (mean age 35.2 +/- 4.4 years, range 26-41 years, four female and eight male). According to the standards of traditional Chinese medicine (TCM), this acupuncture pattern is assumed to be unspecific and non-therapeutic. Flux decreased during the treatment period (p<0.05) compared to the control phase before combined needle acupuncture and moxibustion. After the removal of the needles, flux did not return to the initial control value. No significant differences between mean arterial blood pressure, heart rate, skin temperature or gender were detected. A prediction of individual incidences and kinds of acupuncture effects in our healthy volunteers was not possible. Modern monitoring techniques like LDF could be a method to separate responders from non-responders to acupuncture in peripheral microcirculatory disorders. Further studies on patients with peripheral microcirculatory disorders are necessary in order to demonstrate the value of LDF in detecting responders/non-responders in combination with therapeutic acupuncture patterns according to TCM.

Radiation doses of Swiss population from external sources

The outdoor radiation exposure of the population in Switzerland from external sources results from cosmic background as well as from natural and artificial ground radiation. The geographical distribution of these components and of the total dose rate are represented on maps consisting of 2 kmx2 km grid cells. The average dose rate on Swiss territory outdoors is 147 nSv/h (1.29 mSv/a). The distributions are then related to the population density distribution by GIS application. The population is exposed to an average dose rate of 108 nSv/h (0.95 mSv/a) per capita which is just below the threshold for man-made dose rate given by national regulation. The lower value (relative to the country average 147 nSv/h) arises from the fact that most of the population lives north of the Alps where the lithology is dominated by rocks of relatively low radioactivity and where the cosmic radiation is low relative to the Alps.

Identification and biochemical characterization of Arabidopsis thaliana sulfite oxidase. A new player in plant sulfur metabolism

In mammals and birds, sulfite oxidase (SO) is a homodimeric molybdenum enzyme consisting of an N-terminal heme domain and a C-terminal molybdenum domain (EC ). In plants, the existence of SO has not yet been demonstrated, while sulfite reductase as part of sulfur assimilation is well characterized. Here we report the cloning of a plant sulfite oxidase gene from Arabidopsis thaliana and the biochemical characterization of the encoded protein (At-SO). At-SO is a molybdenum enzyme with molybdopterin as an organic component of the molybdenum cofactor. In contrast to homologous animal enzymes, At-SO lacks the heme domain, which is evident both from the amino acid sequence and from its enzymological and spectral properties. Thus, among eukaryotes, At-SO is the only molybdenum enzyme yet described possessing no redox-active centers other than the molybdenum. UV-visible and EPR spectra as well as apparent K(m) values are presented and compared with the hepatic enzyme. Subcellular analysis of crude cell extracts showed that SO was mostly found in the peroxisomal fraction. In molybdenum cofactor mutants, the activity of SO was strongly reduced. Using antibodies directed against At-SO, we show that a cross-reacting protein of similar size occurs in a wide range of plant species, including both herbacious and woody plants.

Cathepsin S and an asparagine-specific endoprotease dominate the proteolytic processing of human myelin basic protein in vitro

The biochemical characterization of antigen degradation is an important basis for a better understanding of both the immune response and autoimmune diseases mediated by MHC class II molecules. In this study we used high-performance liquid chromatography and mass spectrometry to analyze the processing of myelin basic protein (MBP), a potential autoantigen implicated in the pathogenesis of multiple sclerosis. We resolved the kinetics of MBP processing by lysosomal extracts or purified endocytic proteases, identified the major cleavage sites during this process and assigned them to the activity of proteolytic enzymes. Proteolytic processing of MBP is mostly guided along the hydrophobic regions of the protein. It is initiated by two proteolytic steps (after N(92) and S(110)) that are performed by an asparagine-specific endopeptidase (AEP) and by cathepsin (Cat) S, respectively. The resulting processing intermediates are converted into more than 60 different species of 20-40-mers due to the activity of endopeptidases including CatS, D and L. The fragments thus generated are subsequently degraded by C- or N-terminal trimming. Strikingly, the initial cleavages during MBP processing affect two immunodominant regions of the potential autoantigen [MBP(85-99) and MBP(111-129)] in an inverse manner. CatS directly generates the N terminus of the epitope MBP(111-129) in large quantities during the initial phase of processing, which might explain the immunogenicity of this region in spite of its relatively poor binding to HLA-DR4. In contrast, the dominant cleavage by AEP mediates the destruction of MBP(85-99) unless the epitope is protected, e.g. by binding to HLA-DR. Our results thus characterize the proteolytic events during processing of MBP on a molecular level and suggest a biochemical basis for the immunogenicity of the immunodominant epitopes, which could serve as a guideline for future therapeutic strategies.

Thiocarboxylation of molybdopterin synthase provides evidence for the mechanism of dithiolene formation in metal-binding pterins

Molybdopterin (MPT) is a pyranopterin with a unique dithiolene group coordinating molybdenum (Mo) or tungsten (W) in all Mo- and W-enzymes except nitrogenase. In Escherichia coli, MPT is formed by incorporation of two sulfur atoms into precursor Z, which is catalyzed by MPT synthase. The recently solved crystal structure of MPT synthase (Rudolph, M. J., Wuebbens, M. M., Rajagopalan, K. V., and Schindelin, H. (2000) Nat. Struct. Biol. 8, 42-46) shows the heterotetrameric nature of the enzyme that is composed of two small (MoaD) and two large subunits (MoaE). According to sequence and structural similarities among MoaD, ubiquitin, and ThiS, a thiocarboxylation of the C terminus of MoaD is proposed that would serve as the source of sulfur that is transferred to precursor Z. Here, we describe the in vitro generation of carboxylated and thiocarboxylated MoaD. Both forms of MoaD are monomeric and are able to form a heterotetrameric complex after coincubation in equimolar ratios with MoaE. Only the thiocarboxylated MPT synthase complex was found to be able to convert precursor Z in vitro to MPT. Slight but significant differences between the carboxylated and the thiocarboxylated MPT synthase can be seen using size exclusion chromatography. A two-step reaction of MPT synthesis is proposed where the dithiolene is generated by two thiocarboxylates derived from a single tetrameric MPT synthase.

Crystal structures of human gephyrin and plant Cnx1 G domains: comparative analysis and functional implications

The molybdenum cofactor (Moco) consists of a unique and conserved pterin derivative, usually referred to as molybdopterin (MPT), which coordinates the essential transition metal molybdenum (Mo). Moco is required for the enzymatic activities of all Mo-enzymes, with the exception of nitrogenase and is synthesized by an evolutionary old multi-step pathway that is dependent on the activities of at least six gene products. In eukaryotes, the final step of Moco biosynthesis, i.e. transfer and insertion of Mo into MPT, is catalyzed by the two-domain proteins Cnx1 in plants and gephyrin in mammals. Gephyrin is ubiquitously expressed, and was initially found in the central nervous system, where it is essential for clustering of inhibitory neuroreceptors in the postsynaptic membrane. Gephyrin and Cnx1 contain at least two functional domains (E and G) that are homologous to the Escherichia coli proteins MoeA and MogA, the atomic structures of which have been solved recently. Here, we present the crystal structures of the N-terminal human gephyrin G domain (Geph-G) and the C-terminal Arabidopsis thaliana Cnx1 G domain (Cnx1-G) at 1.7 and 2.6 A resolution, respectively. These structures are highly similar and compared to MogA reveal four major differences in their three-dimensional structures: (1) In Geph-G and Cnx1-G an additional alpha-helix is present between the first beta-strand and alpha-helix of MogA. (2) The loop between alpha 2 and beta 2 undergoes conformational changes in all three structures. (3) A beta-hairpin loop found in MogA is absent from Geph-G and Cnx1-G. (4) The C terminus of Geph-G follows a different path from that in MogA. Based on the structures of the eukaryotic proteins and their comparisons with E. coli MogA, the predicted binding site for MPT has been further refined. In addition, the characterized alternative splice variants of gephyrin are analyzed in the context of the three-dimensional structure of Geph-G.

Reproducibility of HTS-SQUID magnetocardiography in an unshielded clinical environment

A new technology has been developed which measures the magnetic field of the human heart (magnetocardiogram, MCG) by using high temperature superconducting (HTS) sensors. These sensors can be operated at the temperature of liquid nitrogen without electromagnetic shielding. We tested the reproducibility of HTS-MCG measurements in healthy volunteers. Unshielded HTS-MCG measurements were performed in 18 healthy volunteers in left precordial position in two separate sessions in a clinical environment. The heart cycles of 10 min were averaged, smoothed, the baselines were adjusted, and the data were standardized to the respective areas under the curves (AUC) of the absolute values of the QRST amplitudes. The QRS complexes and the ST-T intervals were used to assess the reproducibility of the two measurements. Ratios (R(QRS), R(STT)) were calculated by dividing the AUC of the first measurement by the ones of the second measurement. The linear correlation coefficients (CORR(QRS), CORR(STT)) of the time intervals of the two measurements were calculated, too. The HTS-MCG signal was completely concealed by the high noise level in the raw data. The averaging and smoothing algorithms unmasked the QRS complex and the ST segment. A high reproducibility was found for the QRS complex (R(QRS)=1.2+/-0.3, CORR(QRS)=0.96+/-0.06). Similarly to the shape of the ECG it was characterized by three bends, the Q, R, and S waves. In the ST-T interval, the reproducibility was considerably lower (R(STT)=0.9+/-0.2, CORR(STT)=0.66+/-0.28). In contrast to the shape of the ECG, a baseline deflection after the T wave which may belong to U wave activity was found in a number of volunteers. HTS-MCG devices can be operated in a clinical environment without shielding. Whereas the reproducibility was found to be high for the depolarization interval, it was considerably lower for the ST segment and for the T wave. Therefore, before clinically applying HTS-MCG systems to the detection of repolarization abnormalities in acute coronary syndromes, further technical development of the systems is necessary to improve the signal-to-noise ratio.

Characterisation of the mob locus of Rhodobacter sphaeroides WS8: mobA is the only gene required for molybdopterin guanine dinucleotide synthesis

The mob genes of several bacteria have been implicated in the conversion of molybdopterin to molybdopterin guanine dinucleotide. The mob locus of Rhodobacter sphaeroides WS8 comprises three genes, mobABC. Chromosomal in-frame deletions in each of the mob genes have been constructed. The mobA mutant strain has inactive DMSO reductase and periplasmic nitrate reductase activities (both molybdopterin guanine dinucleotide-requiring enzymes), but the activity of xanthine dehydrogenase, a molybdopterin enzyme, is unaffected. The inability of a mobA mutant to synthesise molybdopterin guanine dinucleotide is confirmed by analysis of cell extracts of the mobA strain for molybdenum cofactor forms following iodine oxidation. Mutations in mobB and mobC are not impaired for molybdoenzyme activities and accumulate wild-type levels of molybdopterin and molybdopterin guanine dinucleotide, indicating they are not compromised in molybdenum cofactor synthesis. In the mobA mutant strain, the inactive DMSO reductase is found in the periplasm, suggesting that molybdenum cofactor insertion is not necessarily a pre-requisite for export.

Effects of QiGong on brain function

QiGong is an ancient and widely practiced Chinese meditation exercise. We studied the effects of QiGong on brain function with modern neuromonitoring tools in two subjects. In a male QiGong master (extremely trained practitioner), the technique induced reproducible changes in transcranial Doppler sonography, EEG, stimulus-induced 40 Hz oscillations, and near-infrared spectroscopy findings. Similar effects were seen after the application of multimodal stimuli and when the master concentrated on intense imagined stimuli (e.g. 22.2% increase in mean blood flow velocity (vm) in the posterior cerebral artery, and a simultaneous 23.1% decrease of vm in the middle cerebral artery). Similar effects were seen in the female subject. Neuromonitoring during QiGong appears able to objectify accompanied cerebral modulations surrounding this old Chinese meditation exercise.

Negative cooperativity and aggregation in biphasic binding of mastoparan X peptide to membranes with acidic lipids

The change of Trp fluorescence intensity when large vesicles with 10% acidic lipid are added to mastoparan X solutions reflects a fast and a slow binding process. By means of a novel procedure of data analysis that takes advantage of so-called mass conservation plots we have separated association isotherms related to: (i) the apparent fast pre-equilibrium; and (ii) the final equilibrium, respectively. This approach also reveals that the intrinsic fluorescence signal of the slow binding is considerably raised against that of the fast binding, presumably indicating a penetration of bound peptide from the lipid/water interface into the apolar lipid core. The shape of either binding curve discloses a pronounced tendency of aggregation. Furthermore, it turns out that in the slow process the final binding ratio decreases markedly compared with the initial fast binding ratio. Accordingly the occupation of final binding sites must exert a substantial effect of negative cooperativity on the affinity of the interfacial binding states.

Chain length dependence of lipid partitioning between the air/water interface and its subphase: thermodynamic and structural implications

We have investigated phosphatidylcholines with the same two saturated hydrocarbon chains of 12, 10 and 8 C-atoms. Langmuir trough data could be evaluated towards even small lipid subphase desorption when applying a novel approach that had recently been developed in our laboratory. The C12 lipid turned out to form a nearly insoluble monolayer with slight desorption only beyond 15 mN/m for an area/volume ratio around 1 cm(-1). Above 22 mN/m micellation in the subphase apparently terminates further accumulation in the interface forcing additionally added lipid to enter the bulk volume. A comparatively substantial increase of solubilization was observed for the C10 monolayer. When turning to the C8 lipid partitioning proved to take place in nearly equal parts. In that case, strong multimeric aggregation is indicated to occur in both the interfacial and the bulk volume domains. All the results are quantitatively discussed in the light of basic thermodynamic and structural considerations.

Pre-inoculation enrichment procedure enhances the performance of bacteriocinogenic Lactococcus lactis meat starter culture

Sodium nitrite and sodium chloride may inhibit growth and bacteriocinogenesis of protective starter cultures. To reduce sensitivity of a lacticin 3147-producing starter culture to nitrite, prior to production of salami, Lactococcus lactis DPC 4275 was placed in a number of pre-inoculation treatments, containing (a) 1% glucose, (b) 2.5 ppm manganese (Mn), (c) 250 ppm magnesium (Mg), (d) 2.5 ppm manganese + 250 ppm magnesium (Mn + Mg), and held at ambient temperature for 30 min and 4 degrees C for 2 h. The growth, pH reduction, and bacteriocin production was monitored in beaker sausage over a period of 10 days at 28 degrees C, corresponding to typical salami production time, and compared to untreated starter culture. The effect of 1% tryptone and inoculum level on growth and bacteriocin production was also determined. Challenge tests were performed using Listeria innocua DPC 1770 and Staphylococcus aureus MMPR3 as target strains. All treatments gave a significantly higher (P < 0.05) initial starter level than the untreated starter. Beaker sausage inoculated with either low (10(7)) or high (10(9)) levels of starter culture, treated with Mn + Mg reached significantly (P < 0.05) higher levels by day 10 than other treatments. Trends indicate that Mn + Mg also gave best pH reduction in sausage containing the low-level starter culture, sausage and significantly lower (P < 0.05) values for sausage produced with higher inoculum. Bacteriocin production was also higher in starter culture treated with Mn, or glucose. Pre-treatment with Mg gave a 2-fold increase in bacteriocin, the addition of Mn augmenting this increase further. The incorporation of tryptone gave no additional effect. In beaker sausage, both L. innocua and S. aureus populations showed significant reductions (P < 0.05) in the presence of the bacteriocinogenic strain compared to a non-bacteriocinogenic control strain.

Interleukin 16 expression in relation to disease activity in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown etiology characterized by an infiltration of CD4+ T lymphocytes within the rheumatoid synovium. Cytokines have been shown to play a modulatory role in the pathogenesis of RA. We analyzed the expression of a T cell derived cytokine. interleukin 16 (IL-16), in relation to disease activity to characterize its biologic function in RA.

METHODS

Secreted IL-16 was measured by enzyme immunoassay in sera and synovial fluids (SF) from 25 patients with RA in comparison to 20 control samples from patients with osteoarthritis (OA). IL-16 expression in peripheral blood mononuclear cells (PBMC) was characterized by flow cytometric analysis after intracellular cytokine staining for IL-16. In synovial tissue specimens, IL-16 mRNA expression was analyzed by real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR). In parallel, expression of IL-16 was localized in synovial tissues by in situ hybridization and immunohistochemistry. Results were analyzed in relation to disease activity.

RESULTS

IL-16 was detected at significantly higher levels in sera and SF of patients with RA in comparison to OA (p < 0.001). Flow cytometry of PBMC showed that a great proportion of both CD4+ and CD8+ T cells constitutively expressed the IL-16 protein. In synovial tissues, IL-16 mRNA levels were significantly elevated in comparison to OA controls (p < 0.001). In situ hybridization for IL-16 producing cells revealed a predominant accumulation of IL- 16 positive cells within the inflammatory infiltrates. A significant correlation between IL- 16 expression and local inflammatory activity could not be established (r = 0.27, p = 0.19) by microscopic analysis of the synovial cell infiltrate. In addition, no significant association was observed between serum, SF, and synovial tissue expression of IL-16 and clinical disease activity in RA.

CONCLUSION

These data suggest IL-16 might play a role in the pathogenesis of chronic inflammation in RA. The lack of significant correlation between IL-16 expression, clinical disease activity, and local inflammatory activity suggests a regulatory rather than a proinflammatory function for IL-16 in the pathogenesis of chronic synovial inflammation in RA.

Airborne surveys of Swiss nuclear facility sites

Annually since 1989, biannually since 1994, the environs (approximately 50 km2) of the Swiss nuclear facilities are surveyed (by helicopters) flying the same survey lines. The equipment and the data processing software used for these surveys were built and developed at the Institute of Geophysics, ETH Zurich. For mapping of man-made radiation at or around nuclear facility sites a pixel representation and the MMGC (man-made gross count) ratio is used. So far no artificial radioactivity that could not be explained by the Chernobyl event (1986) or by earlier nuclear weapon tests was detected outside the fenced sites of the nuclear facilities.

A mutation in the gene for the neurotransmitter receptor-clustering protein gephyrin causes a novel form of molybdenum cofactor deficiency

Gephyrin was originally identified as a membrane-associated protein that is essential for the postsynaptic localization of receptors for the neurotransmitters glycine and GABA(A). A sequence comparison revealed homologies between gephyrin and proteins necessary for the biosynthesis of the universal molybdenum cofactor (MoCo). Because gephyrin expression can rescue a MoCo-deficient mutation in bacteria, plants, and a murine cell line, it became clear that gephyrin also plays a role in MoCo biosynthesis. Human MoCo deficiency is a fatal disease resulting in severe neurological damage and death in early childhood. Most patients harbor MOCS1 mutations, which prohibit formation of a precursor, or carry MOCS2 mutations, which abrogate precursor conversion to molybdopterin. The present report describes the identification of a gephyrin gene (GEPH) deletion in a patient with symptoms typical of MoCo deficiency. Biochemical studies of the patient's fibroblasts demonstrate that gephyrin catalyzes the insertion of molybdenum into molybdopterin and suggest that this novel form of MoCo deficiency might be curable by molybdate supplementation.

The molybdenum cofactor biosynthetic protein Cnx1 complements molybdate-repairable mutants, transfers molybdenum to the metal binding pterin, and is associated with the cytoskeleton

Molybdenum (Mo) plays an essential role in the active site of all eukaryotic Mo-containing enzymes. In plants, Mo enzymes are important for nitrate assimilation, phytohormone synthesis, and purine catabolism. Mo is bound to a unique metal binding pterin (molybdopterin [MPT]), thereby forming the active Mo cofactor (Moco), which is highly conserved in eukaryotes, eubacteria, and archaebacteria. Here, we describe the function of the two-domain protein Cnx1 from Arabidopsis in the final step of Moco biosynthesis. Cnx1 is constitutively expressed in all organs and in plants grown on different nitrogen sources. Mo-repairable cnxA mutants from Nicotiana plumbaginifolia accumulate MPT and show altered Cnx1 expression. Transformation of cnxA mutants and the corresponding Arabidopsis chl-6 mutant with cnx1 cDNA resulted in functional reconstitution of their Moco deficiency. We also identified a point mutation in the Cnx1 E domain of Arabidopsis chl-6 that causes the molybdate-repairable phenotype. Recombinant Cnx1 protein is capable of synthesizing Moco. The G domain binds and activates MPT, whereas the E domain is essential for activating Mo. In addition, Cnx1 binds to the cytoskeleton in the same way that its mammalian homolog gephyrin does in neuronal cells, which suggests a hypothetical model for anchoring the Moco-synthetic machinery by Cnx1 in plant cells.

Two new proteases in the MHC class I processing pathway

The proteasome generates exact major histocompatibility complex (MHC) class I ligands as well as NH2-terminal-extended precursor peptides. The proteases responsible for the final NH2-terminal trimming of the precursor peptides had, until now, not been determined. By using specific selective criteria we purified two cytosolic proteolytic activities, puromycin-sensitive aminopeptidase and bleomycin hydrolase. These proteases could remove NH2-terminal amino acids from the vesicular stomatitis virus nucleoprotein cytotoxic T cell epitope 52-59 (RGYVYQGL) resulting, in combination with proteasomes, in the generation of the correct epitope. Our data provide evidence for the existence of redundant systems acting downstream of the proteasome in the antigen-processing pathway for MHC class I molecules.