City spore concentrations in the European Economic Community (EEC). VI. Poaceae (Grasses), 1982–1986

Summary Airborne grass-pollen concentrations in six cities in the EEC are compared, based on observations from five years, 1982–1986. Results show that there are quantitative differences both between the monitoring stations and between the years. Very provisionally, the average seasonal total of the European urban airborne grass-pollen concentration can be put at 4 to 5000 per m³ of air. Also qualitatively, regarding the seasonal fluctuations, there are differences between the stations, and between the years. Generally, the results confirm that June is the most typical grass-pollen month in northwestern Europe, whereas in mediterranean Europe May is the more prominent grass-pollen period. There seems to be little coherence between the starting dates of the grass-pollen season even at relatively nearby stations in northwestern Europe, suggestive for a great influence of the actual weather situation.     

Effect of Insulin-Induced Hypoglycemia on the Concentrations of Glutamate and Related Amino Acids and Energy Metabolites in the Intact and Decorticated Rat Neostriatum

Abstract The glutamate (Glu) terminals in rat neostriatum were removed by a unilateral frontal decortication. One to two weeks later the effects of insulin-induced hypoglycemia on the steady-state levels of amino acids [Glu, glutamine (Gin), aspartate (Asp), γ-aminobutyric acid (GABA), tau-rine] and energy metabolites (glucose, glycogen, α-ketoglu-tarate, pyruvate, lactate, ATP, ADP, AMP, phosphocre-atine) were examined in the intact and decorticated neostriatum from brains frozen in situ. The changes in the metabolite levels were examined during normoglycemia, hypoglycemia with burst-suppression (BS) EEG, after 5 and 30 min of hypoglycemic coma with isoelectric EEG, and 1 h of recovery following 30 min of isoelectric EEG. In normoglycemia Glu decreased and Gin and glycogen increased significantly on the decorticated side. During the BS period no significant differences in the measured compounds were noted between the two sides. After 5 min of isoelectric EEG Glu, Gin, GABA, and ATP levels were significantly lower and Asp higher on the intact than on the decorticated side. No differences between the two sides were found after 30 min of isoelectric EEG. After 1 h of recovery from 30 min of isoelectric EEG Glu, Gin, and glycogen had not reached their control levels. Glu was significantly lower, and Gin and glycogen higher on the decorticated side. The Asp and GABA levels were not significantly different from control levels. The results indicate that the turnover of Glu is higher in the intact than in decorticated neostriatum during profound hypoglycemia.     

Plakoglobin has both structural and signalling roles in zebrafish development

Plakoglobin, or gamma-catenin, is found in both desmosomes and adherens junctions and participates in Wnt signalling. Mutations in the human gene are implicated in the congenital heart disorder, arrhythmogenic right ventricular cardiomyopathy (ARVC), but the signalling effects of plakoglobin loss in ARVC have not been established. Here we report that knockdown of plakoglobin in zebrafish results in decreased heart size, reduced heartbeat, cardiac oedema, reflux of blood between heart chambers and a twisted tail. Wholemount in situ hybridisation shows reduced expression of the heart markers nkx2.5 at 24 hours post fertilisation (hpf), and cmlc2 and vmhc at 48 hpf, while there is lack of restriction of the valve markers notch1b and bmp4 at 48 hpf. Wnt target gene expression was examined by semi-quantitative RT-PCR and found to be increased in morphant embryos indicating that plakoglobin is antagonistic to Wnt signalling. Co-expression of the Wnt inhibitor, Dkk1, rescues the cardiac phenotype of the plakoglobin morphant. β-catenin protein expression is increased in morphant embryos as is its colocalisation with E-cadherin in adherens junctions. Endothelial cells at the atrioventricular boundary of morphant hearts have an aberrant morphology, indicating problems with valvulogenesis. Morphants also have decreased numbers of desmosomes and adherens junctions in the intercalated discs. These results establish the zebrafish as a model for ARVC caused by loss of plakoglobin function and indicate that there are signalling as well as structural consequences of this loss.     

Use of Pleurotus dryinus for lignocellulolytic enzymes production in submerged fermentation of mandarin peels and tree leaves

It has been shown that the wood-rotting mushroom Pleurotus dryinus IBB 903 is able to effectively produce cellulases, xylanase, laccase, and manganese peroxidase in submerged fermentation of mandarin peels and tree leaves. Gradual increasing of lignocellulosic substrates concentration from 1 to 4–6% enhanced enzyme accumulation in culture liquid. A simple and inexpensive medium containing mandarin peels and yeast extract as sole carbon and nitrogen sources allowed simultaneous production of high levels of both hydrolases and oxidases by P. dryinus IBB 903. Supplementation of this medium by copper and manganese caused earlier and faster accumulation of laccase and manganese peroxidase increasing their yield by 1.5 and 7.5 times, respectively. In addition, by adding manganese to the medium it is possible to regulate the ratio of laccase and MnP in enzyme preparation. The presence of lignocellulosic substrate is the requisite for MnP production by P. dryinus IBB 903 since there was no production of MnP when mushroom has been cultivated in the synthetic medium with different carbon source. Among carbon source tested only utilization of glucose resulted to 21-fold increase of fungus laccase specific activity compared to control medium without carbon source. Carboxymethyl cellulase and xylanase appeared to be inducible enzymes.     

Inequalities of visceral leishmaniasis case-fatality in Brazil: A multilevel modeling considering space,time, individual and contextual factors

BackgroundIn Brazil, case-fatality from visceral leishmaniasis (VL) is high and characterized by wide differences between the various political-economic units, the federated units (FUs). This study was designed to investigate the association between factors at the both FU and individual levels with the risk of dying from VL, after analysing the temporal trend and the spatial dependency for VL case-fatality.MethodologyThe analysis was based on individual and aggregated data of the Reportable Disease Information System-SINAN (Brazilian Ministry of Health). The temporal and spatial distributions of the VL case-fatality between 2007 and 2017 (27 FUs as unit of analysis) were considered together with the individual characteristics and many other variables at the FU level (socioeconomic, demographic, access to health and epidemiological indicators) in a mixed effects models or multilevel modeling, assuming a binomial outcome distribution (death from VL).FindingsA linear increasing temporal tendency (4%/year) for VL case-fatality was observed between 2007 and 2017. There was no similarity between the case-fatality rates of neighboring FUs (non-significant spatial term), although these rates were heterogeneous in this spatial scale of analysis. In addition to the known individual risk factors age, female gender, disease’s severity, bacterial co-infection and disease duration, low level schooling and unavailability of emergency beds and health professionals (the last two only in univariate analysis) were identified as possibly related to VL death risk. Lower VL incidence was also associated to VL case-fatality, suggesting that unfamiliarity with the disease may delay appropriate medical management: VL patients with fatal outcome were notified and had VL treatment started 6 and 3 days later, respectively, in relation to VL cured patients. Access to garbage collection, marker of social and economic development, seems to be protective against the risk of dying from VL. Part of the observed VL case-fatality variability in Brazil could not be explained by the studied variables, suggesting that factors linked to the intra FU environment may be involved.ConclusionsThis study aimed to identify epidemiological conditions and others related to access to the health system possibly linked to VL case-fatality, pointing out new prognostic determinants subject to intervention.     

Human ex vivo carcinoma cells produce transforming growth factor β and thereby can inhibit lymphocyte functions in vitro

 We tested 20 human carcinoma samples for the production of transforming growth factor β (TGFβ) in vitro. Tumour cell suspensions without obvious contamination with non-malignant cells were kept in culture conditions for 16 h and their supernatants were added to CCL-64 cells. The proliferation of these cells is inhibited by TGFβ. According to this assay, the supernatants contained both active and latent TGFβ. In addition, the supernatants were found to suppress the spontaneous cytotoxic function and activation of T-cell-enriched lymphocyte populations. A specific monoclonal antibody (mAb) counteracted these effects and therefore we concluded that they were mediated to a large extent by TGFβ. In line with the results obtained with the supernatants, activation of lymphocytes could also be inhibited by tumour cells and their inhibitory effect was weaker in the presence of the TGFβ-specific mAb. It is important to note that, when TGFβ-specific mAb was added to autologous mixed lymphocyte/tumour cell cultures, lymphocyte activation occurred more often. These results thus substantiate the assumption that production of TGFβ may help the survival of potentially immunogenic tumour cells in immunocompetent patients. Received: 21 August 1996 / Accepted: 12 November 1996     

Protein exporter function and in vitro ATPase activity are correlated in ABC-domain mutants of HlyB

The Escherichia coli toxin exporter HlyB comprises an integral membrane domain fused to a cytoplasmic domain of the ATP-binding casette (ABC) super-family, and it directs translocation of the 110kDa haemolysin protein out of the bacterial cell without using an N-terminal secretion signal peptide. We have exploited the ability to purify the soluble HlyB ABC domain as a fusion with glutathione S-transferase to obtain a direct correlation of the in vivo export of protein by HlyB with the degree of ATP binding and hydrolysis measured in vitro. Mutations in residues that are invariant or highly conserved in the ATP-binding fold and glycine-rich linker peptide of prokaryotic and eukaryotic ABC transporters caused a complete less of both HlyB exporter function and ATPase activity in proteins still able to bind ATP effectively and undergo ATP-induced conformational change. Mutation of less-conserved residues caused reduced export and ATP hydrolysis, but not ATP binding, whereas substitutions of poorly conserved residues did not impair activity either in vivo or in vitro. The data show that protein export by HlyB has an absolute requirement for the hydrolysis of ATP bound by its cytoplasmic domain and indicate that comparable mutations that disable other prokaryotic and eukaryotic ABC transporters also cause a specific loss of enzymatic activity.     

Three's company: component structures bring a closer view of tripartite drug efflux pumps

Bacterial multidrug resistance is a serious clinical problem and is commonly conferred by tripartite efflux 'pumps' in the prokaryotic cell envelope. Crystal structures of the three components of a drug efflux pump have now been solved: the outer membrane TolC exit duct in the year 2000, the inner membrane AcrB antiporter in 2002 and the periplasmic adaptor MexA in 2004. These structures have enhanced our understanding of the principles underlying pump assembly and operation, and present pumps as new drug targets.