'Doing school food!': a practical toolkit for adopting a whole school food approach.

AIMS: The dietary intake and reported eating behaviours of adolescents in the UK are a public health concern. Schools are identified as an ideal 'place' setting to promote health and improve young peoples' nutrition outcomes. A gap in the understanding of how healthy secondary school food policy can be implemented, sustainable and effective, may hamper progress to improving school food provision and nutrition education in the UK. Research was conducted to understand the factors which influence healthy school food provision and the adolescent's food choice to inform and develop a practical framework for schools. METHODS: This research involves the development of a practical toolkit which synthesises evidence generated from a mixed methods study and a systematic review. This was informed by an exploration of the secondary school food environment as a potentially 'obesogenic' setting, the effectiveness of school food interventions and policy in Europe and UK, included young people's (11-18 years of age) eating behaviours and priorities in food choice. A pragmatic approach was taken in the integration of evidence, using ecological and behaviour change theory, and joint display principles. RESULT: A six-phase practical toolkit is presented, guided by 'What Good Looks Like' and 'Whole Systems Approach to Obesity' principles which can be used to translate the evidence from this research into good school food practice. CONCLUSION: Improving secondary school food provision across the school day and having a coherent whole school food approach to healthy eating have the potential to significantly improve a young person's food choice, therefore impacting the nutrient intake of adolescents in the UK. This toolkit helps working towards operationalising this idea.

Assessment of ectomycorrhizal fungal communities in the natural habitats of Tuber magnatum (Ascomycota, Pezizales).

The ectomycorrhizal (ECM) fungal communities of four natural Tuber magnatum truffle grounds, located in different Italian regions (Abruzzo, Emilia-Romagna, Molise, and Tuscany), were studied. The main objective of this study was to characterize and compare the ECM fungal communities in the different regions and in productive (where T. magnatum ascomata were found) and nonproductive points. More than 8,000 (8,100) colonized root tips were counted in 73 soil cores, and 129 operational taxonomic units were identified using morphological and molecular methods. Although the composition of the ECM fungal communities studied varied, we were able to highlight some common characteristics. The most plentiful ECM fungal taxa belong to the Thelephoraceae and Sebacinaceae families followed by Inocybaceae and Russulaceae. Although several ectomycorrhizas belonging to Tuber genus were identified, no T. magnatum ectomycorrhizas were found. The putative ecological significance of some species is discussed.

Antimicrobial action of Nitens mouthwash (cetyltrimethylammonium naproxenate) on multiple isolates of pharyngeal microbes: a controlled study against chlorhexidine, benzydamine, hexetidine, amoxicillin, amoxicillin-clavulanate, clarithromycin, and cefaclor.

BACKGROUND: Acute oropharyngeal and respiratory tract infections are due to a wide spectrum of microorganisms. The aim of this study was to compare and evaluate the in vitro activity of four antiseptics (cetyltrimethylammonium naproxenate, chlorhexidine, benzydamine, hexetidine) to four antibiotics (amoxicillin, amoxicillin-clavulanate, clarithromycin, cefaclor) on strains of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes and Streptococcus pneumoniae. METHODS: Susceptibility tests were performed on 90, aerobic and anaerobic, bacterial strains, isolated from nasopharyngeal swabs and sputum. Minimum inhibitory concentrations (by microdilution) and minimum bactericidal concentrations were determined and compared. RESULTS: Our selected panel of bacteria was highly susceptible to the antiseptics, particularly to chlorhexidine and naproxenate, even more so than two of the most frequently used antibiotics. Data were statistically significant (p < 0.005). CONCLUSIONS: In view of their bactericidal and anti-inflammatory properties, these antiseptics may be effective in controlling the transitory colonization of the oral cavity by microbes that cause or worsen disease in patients with mild infections.

Analysis of mutants of tetanus toxin Hc fragment: ganglioside binding, cell binding and retrograde axonal transport properties.

Tetanus toxin binds neuronal tissue prior to internalization and trafficking to the central nervous system. Binding of the carboxy-terminal 50 kDa HC fragment of tetanus toxin to polysialogangliosides is important for this initial cell binding step. Using the three-dimensional structure of HC, mutants were designed to investigate the role of individual residues in ganglioside binding. Mutant proteins were tested for binding to GT1b gangliosides, to primary motoneurons and for their ability to undergo retrograde transport in mice. Two classes of mutant were obtained: (i) those containing deletions in loop regions within the C-terminal beta-trefoil domain which showed greatly reduced ganglioside and cell binding and did not undergo retrograde transport and (ii) those that showed reduced ganglioside binding, but retained primary neuronal cell binding and retrograde transport. The second class included point mutants of Histidine-1293, previously implicated in GT1b binding. Our deletion analysis is entirely consistent with recent structural studies which have identified sugar-binding sites in the immediate vicinity of the residues identified by mutagenesis. These results demonstrate that ganglioside binding can be severely impaired without abolishing cell binding and intracellular trafficking of tetanus toxin.

Glutathione depletion in PC12 results in selective inhibition of mitochondrial complex I activity. Implications for Parkinson's disease.

Oxidative stress appears to play an important role in degeneration of dopaminergic neurons of the substantia nigra (SN) associated with Parkinson's disease (PD). The SN of early PD patients have dramatically decreased levels of the thiol tripeptide glutathione (GSH). GSH plays multiple roles in the nervous system both as an antioxidant and a redox modulator. We have generated dopaminergic PC12 cell lines in which levels of GSH can be inducibly down-regulated via doxycycline induction of antisense messages against both the heavy and light subunits of gamma-glutamyl-cysteine synthetase, the rate-limiting enzyme in glutathione synthesis. Down-regulation of glutamyl-cysteine synthetase results in reduction in mitochondrial GSH levels, increased oxidative stress, and decreased mitochondrial function. Interestingly, decreases in mitochondrial activities in GSH-depleted PC12 cells appears to be because of a selective inhibition of complex I activity as a result of thiol oxidation. These results suggest that the early observed GSH losses in the SN may be directly responsible for the noted decreases in complex I activity and the subsequent mitochondrial dysfunction, which ultimately leads to dopaminergic cell death associated with PD.

Tetanus toxin fragment C binds to a protein present in neuronal cell lines and motoneurons.

Tetanus Toxin Fragment C Binds to a Protein Present in Neuronal Cell Lines and Motoneurons Tetanus neurotoxin is one of the most powerful protein toxins known, acting in vivo at femtomolar doses. Two main factors determine its high potency: a protease activity restricted to a single intracellular substrate and its absolute neurospecificity. Whereas the enzymatic properties of tetanus toxin have been thoroughly defined, the nature of its neuronal receptor(s) and their involvement in the intracellular trafficking of tetanus toxin are poorly understood. Using binding and crosslinking experiments, we report here on the characterisation of an N-glycosylated 15-kDa interacting protein, which behaves as an integral membrane protein. This putative receptor specifically interacts with the binding domain (fragment C) of tetanus toxin and not with several related botulinum neurotoxins in spinal cord motoneurons and neuronal-like cell lines. Sialic acid-specific lectins antagonise the binding of tetanus toxin to the cell surface and to the 15-kDa protein, supporting the central role of sialic acid residues in the recognition process. Altogether, these results indicate the existence of a neuronal protein receptor for tetanus toxin whose identification is likely to constitute a key step in the analysis of the molecular machinery involved in the toxin internalisation and retrograde transport.

C-terminal half of tetanus toxin fragment C is sufficient for neuronal binding and interaction with a putative protein receptor.

Tetanus neurotoxin (TeNT) is a powerful bacterial protein toxin that cleaves VAMP/synaptobrevin, an essential protein of the synaptic vesicle fusion machinery, and consequently blocks neurotransmission. The extreme neurospecificity of TeNT is determined by the binding of its C-terminal domain (fragment C or H(C)) to neuronal receptors. Whereas polysialogangliosides are known acceptors for the toxin, the existence of additional protein receptors has also been suggested. We have reported previously on a 15 kDa cell-surface glycoprotein that interacts with TeNT in neuronal cell lines and motoneurons [Herreros, Lalli, Montecucco and Schiavo (2000) J. Neurochem., in the press]. Here, on the basis of the structural information provided by the crystallization of fragment C of TeNT, we have expressed its C-and N-terminal halves as recombinant proteins and analysed their binding abilities to rat phaeochromocytoma (PC12) cells differentiated with nerve growth factor. We found that the C-terminal subdomain of the fragment C of TeNT is necessary and sufficient for cell binding and for the interaction with the 15 kDa putative receptor. In contrast, the N-terminal half showed a very poor interaction with the cell surface. These results restrict the binding domain of TeNT to the C-terminal half of the fragment C and highlight the importance of this domain for the neurospecific interaction of the toxin with the synapse. Furthermore, these findings support the use of this portion of TeNT as a neurospecific targeting device, pointing to an involvement of the N-terminal subdomain in later steps of the intoxication pathway.

Functional characterisation of tetanus and botulinum neurotoxins binding domains.

Tetanus and botulinum neurotoxins constitute a family of bacterial protein toxins responsible for two deadly syndromes in humans (tetanus and botulism, respectively). They bind with high affinity to neurons wherein they cause a complete inhibition of evoked neurotransmitter release. Here we report on the cloning, expression and use of the recombinant fragments of the heavy chains of tetanus neurotoxin and botulinum neurotoxin serotypes A, B and E as tools to study the neurospecific binding of the holotoxins. We found that the recombinant 50 kDa carboxy-terminal domains of tetanus and botulinum neurotoxins alone are responsible for the specific binding and internalisation into spinal cord cells in culture. Moreover, we provide evidence that the recombinant fragments block the internalization of the parental holotoxins in a dose-dependent manner, as determined by following the neurotoxin-dependent cleavage of their targets VAMP/synaptobrevin and SNAP-25. In addition, the recombinant binding fragments cause a significant delay in the paralysis induced by the corresponding holotoxin on the mouse phrenic nerve-hemidiaphragm preparation. Taken together, these results show that the carboxy-terminal domain of tetanus and botulinum neurotoxins is necessary and sufficient for the binding and internalisation of these proteins in neurons and open the possibility to use them as tools for the functional characterisation of the intracellular transport of clostridial neurotoxins.

Association between chronic lymphocytic leukaemia and secondary tumours: unusual occurrence of a neuroendocrine (Merkell cell) carcinoma.

The authors describe a case of cutaneous neuroendocrine (Merkell cell) carcinoma in a patient previously treated for Chronic Lymphocytic Leukaemia (CLL). The authors discuss some of the mechanisms concerning the increased frequency of a second tumour in patients with CLL and focus attention on the high incidence in CLL of secondary tumours, especially skin tumours, of which Merkell cell carcinoma is a rare example. The authors consider the possible therapeutic approaches, reported in the literature, for the treatment of this particular skin carcinoma, which on account of its aggressiveness and the preexistence of a leukaemic process requires a particularly careful therapeutic approach.

Secondary leukaemias. Clinical and cytobiological aspects.

Patients treated with radiation and cytotoxic agents for a variety of neoplastic conditions develop with increased frequency a secondary leukaemia, usually a form of acute myeloblastic leukaemia. The authors illustrate and discuss the various morphological and cytobiological which characterize the "preleukaemic phase", and which comprise myelodysplastic alterations, cytochemical abnormalities, concerning the presence of glycogen and free iron in the red cell series, as well as a number of changes in enzymatic activities in the myeloid series, cytokinetic changes, indicative of accumulation of cells in G0 and G1, cytogenetic non-random abnormalities, involving specific chromosomes, and finally in vitro cultures which show a reduction in colony formation. The authors underline the differences between primary and secondary preleukaemic myelodysplastic states, consisting in the presence in the latter of frequent hypocellularity, fibrosis and almost invariability a clear involvement of multiple cell lines.

Howell-Jolly body counting as a measure of splenic function. A reassessment.

Non-surgical and surgical asplenia predisposes to fatal infections; therefore, simple, non-invasive and repeatable tests for assessing splenic function are required, even in non-specialized medical institutions. Howell-Jolly bodies are the most characteristic peripheral blood abnormality after splenectomy, but their counting is not considered a reliable measure of splenic function. In this study, in a group of splenectomized subjects and of patients with non-surgical hyposplenism, we have compared counting of Howell-Jolly bodies, stained by both the May-Grünwald/Giemsa method and the Feulgen reaction, with pitted cell counting which is considered a reliable technique for the assessment of splenic hypofunction. A significant correlation has been found between Howell-Jolly body counts, stained by either technique, and pitted cell counts (P less than 0.0001). Through Howell-Jolly bodies were never detectable when pitted cell counts fell between 4 and 8%, values consistent with a very mild splenic hypofunction, for pitted cell counts above 8% their increase was always associated with increasing Howell-Jolly body counts. These data suggest that, although pitted cell counting represents a more sensitive method for evaluating splenic function, Howell-Jolly body counting may still be regarded as a simple and reliable technique for identifying and monitoring those cases associated with a real risk of overwhelming infections.

[The artificial pancreas in the evaluation of insulin sensitivity in healthy subjects]. / Il pancreas artificiale nella valutazione della sensibilita all'insulin nel soggetto sano.

24-hours peripheral insulin sensitivity was studied in 5 healthy subjects by mean of artificial pancreas (Biostator), using the glycemic clamp technique (100 mg%). A sharp rise of insulin sensitivity (expressed as glucose required/insulin evoked ratio) was obtained in the morning, confirming our previous data observed by insulin tolerance test, but in a more physiological condition. The subjects appeared well synchronized as documented by statistically significant circadian rhythms in both serum cortisol and body temperature.