Ambulance dispatch versus general practitioner home visit for highly urgent out-of-hours primary care.

Background: Patients with life-threatening conditions who contact out-of-hours primary care either receive a home visit from a GP of a GP cooperative (GPC) or are handed over to the ambulance service. Objective: The objective of this study was to determine whether highly urgent visits, after a call to the GPC, are delivered by the most appropriate healthcare provider: GPC or ambulance service. Methods: We performed a cross-sectional study using patient record data from a GPC and ambulance service in an urban district in The Netherlands. During a 21-month period, all calls triaged as life-threatening (U1) to the GPCs were included. The decision to send an ambulance or not was made by the triage nurse following a protocolized triage process. Retrospectively, the most appropriate care was judged by the patient's own GP, using a questionnaire. Results: Patient and care characteristics from 1081 patients were gathered: 401 GPC visits, 570 ambulance responses and 110 with both ambulance and GPC deployment. In 598 of 1081 (55.3%) cases, questionnaires were returned by the patients' own GP. About 40% of all visits could have been carried out with a lower urgency in retrospect, and almost half of all visits should have received a different type of care or different provider. In case of ambulance response, 60.7% concerned chest pain. Conclusion: Research should be done on the process of triage and allocation of care to optimize labelling complaints with the appropriate urgency and to deploy the appropriate healthcare provider, especially for patients with chest pain.

Protein costs do not explain evolution of metabolic strategies and regulation of ribosomal content: does protein investment explain an anaerobic bacterial Crabtree effect?

Protein investment costs are considered a major driver for the choice of alternative metabolic strategies. We tested this premise in Lactococcus lactis, a bacterium that exhibits a distinct, anaerobic version of the bacterial Crabtree/Warburg effect; with increasing growth rates it shifts from a high yield metabolic mode [mixed-acid fermentation; 3 adenosine triphosphate (ATP) per glucose] to a low yield metabolic mode (homolactic fermentation; 2 ATP per glucose). We studied growth rate-dependent relative transcription and protein ratios, enzyme activities, and fluxes of L. lactis in glucose-limited chemostats, providing a high-quality and comprehensive data set. A three- to fourfold higher growth rate rerouted metabolism from acetate to lactate as the main fermentation product. However, we observed hardly any changes in transcription, protein levels and enzyme activities. Even levels of ribosomal proteins, constituting a major investment in cellular machinery, changed only slightly. Thus, contrary to the original hypothesis, central metabolism in this organism appears to be hardly regulated at the level of gene expression, but rather at the metabolic level. We conclude that L. lactis is either poorly adapted to growth at low and constant glucose concentrations, or that protein costs play a less important role in fitness than hitherto assumed.

Lactococcus lactis†YfiA is necessary and sufficient for ribosome dimerization.

Dimerization and inactivation of ribosomes in Escherichia coli is a two-step process that involves the binding of ribosome modulation factor (RMF) and hibernation promotion factor (HPF). Lactococcus lactis MG1363 expresses a protein, YfiA(L) (l) , which associates with ribosomes in the stationary phase of growth and is responsible for dimerization of ribosomes. We show that full-length YfiA(L) (l) is necessary and sufficient for ribosome dimerization in L. lactis but also functions heterologously in vitro with E. coli ribosomes. Deletion of the yfiA gene has no effect on the growth rate but diminishes the survival of L. lactis under energy-starving conditions. The N-terminal domain of YfiA(L) (l) is homologous to HPF from E. coli, whereas the C-terminal domain has no counterpart in E. coli. By assembling ribosome dimers in vitro, we could dissect the roles of the N- and C-terminal domains of YfiA(L) (l) . It is concluded that the dimerization and inactivation of ribosomes in L. lactis and E. coli differ in several cellular and molecular aspects. In addition, two-dimensional maps of dimeric ribosomes from L. lactis obtained by single particle electron microscopy show a marked structural difference in monomer association in comparison to the ribosome dimers in E. coli.

Gene-Trait Matching and Prevalence of Nisin Tolerance Systems in Lactococus lactis.

Lactococcus lactis cheese starter cultures typically contain a mix of many strains and may include variants that produce and/or tolerate the antimicrobial bacteriocin nisin. Nisin is well-established as an effective agent against several undesirable Gram-positive bacteria in cheese and various other foods. In the current study, we have examined the effect of nisin on 710 individual L. lactis strains during milk fermentations. Changes in milk acidification profiles with and without nisin exposure, ranging from unaltered acidification to loss of acidification, could be largely explained by the type(s) and variants of nisin immunity and nisin degradation genes present, but surprisingly, also by genotypic lineage (L. lactis ssp. cremoris vs. ssp. lactis). Importantly, we identify that nisin degradation by NSR is frequent among L. lactis and therefore likely the main mechanism by which dairy-associated L. lactis strains tolerate nisin. Insights from this study on the strain-specific effect of nisin tolerance and degradation during milk acidification is expected to aid in the design of nisin-compatible cheese starter cultures.

Mental health problems among search and rescue workers deployed in the Haïti earthquake 2010: a pre-post comparison.

Search and rescue workers play an important role in rescuing trapped disaster victims. However, it is unclear whether they are at risk for post-disaster mental health problems. For this purpose we prospectively examined pre- and post-deployment health among Dutch search and rescue workers (USAR NL) deployed in the devastating Haiti earthquake disaster (2010). The evening before departure (T1, response=100%) and 3 months post-deployment (T2, response=91%), Search and rescue workers were administered standardized questionnaires assessing health (SCL-90-R, RAND-36), including use of substances and mental health services utilization (N=51). At T2 event-related PTSD-symptoms (IES) and coping self-efficacy (CSE), and experiences during and after deployment were examined. At both surveys health problems were almost absent and no significant increases in health problems and use of substances were found. PTSD-symptomatology was very low and coping self-efficacy rather high. Protective factors such as good team functioning, recognition and job satisfaction were clearly present, while risk factors such as sustained injuries or death of a co-worker were absent. Findings suggest that post-disaster health problems may (partly) be prevented by enhancing or restoring protective factors.