Biogenic amine production by Lactobacillus

AIMS: The aim of this work was to demonstrate that strains of Lactobacillus may be able to produce putrescine and agmatine from one of the major amino acids present in fruit juices and wine, arginine, and from amino acid-derived ornithine. METHODS AND RESULTS: Biogenic amines were determined by HPLC. Their production in the culture medium was similar under both microaerophilic and anaerobic conditions. The presence of Mn2+ had a minimal influence on the results, whereas the addition of pyridoxal phosphate increased amine production 10-fold. Lactobacillus hilgardii X1B, isolated from wine, was able to degrade arginine by two pathways: arginine deiminase and arginine decarboxylase. The isolate was able to produce putrescine from ornithine and from agmatine. Lactobacillus plantarum strains N4 and N8, isolated from orange, utilized arginine via the arginine deiminase system. Only the N4 strain was able to produce putrescine from ornithine. CONCLUSION: It has been demonstrated that Lact. hilgardii X1B is able to produce the most important biogenic amine found in wine, putrescine, and also agmatine from arginine and ornithine, and that Lactobacillus plantarum, considered to be an innocuous spoilage micro-organism in fruit juices, is able to produce amines. SIGNIFICANCE AND IMPACT OF THE STUDY: The results have significance in relation to food poisoning caused by beverages that have been contaminated with biogenic amines.     

Dust accumulation due to anthropogenic impact induces anatomical and photochemical changes in leaves of Centranthus ruber growing on the slope of the Vesuvius volcano

• In Mediterranean ecosystems, some natural areas are exposed to severe anthropogenic impact. Especially in summer, the considerable number of tourists visiting such areas, often with vehicles, causes deposition of dust over the vegetation due to formation of powder clouds, also favoured by wind erosion, high temperature, low precipitation and incoherent soil structure. The main aim of this study was to analyse whether the deposition of dust can induce changes in leaf anatomical functional traits and in the efficiency of photosynthetic apparatus in Centranthus ruber, a species widespread in Mediterranean ecosystems.
• Leaf morpho‐functional traits were quantified in plants growing at sites characterised by high (HD) and low (LD) dust deposition, in periods with high anthropogenic impact. Analyses included quantification of chlorophyll fluorescence emission parameters, photosynthetic pigment concentration as well as stomatal size and frequency, leaf lamina thickness, quantification of intercellular spaces and phenolics in the mesophyll through microscopy.
• The overall analysis suggested that the different conditions of dust deposition induced different adjustment of morpho‐functional traits in leaves of C. ruber. High dust deposition shielded the leaf lamina, protecting the photosynthetic apparatus from excess light and favoured plant photochemical efficiency. Leaves exposed to low dust deposition showed higher accumulation of phenolic compounds, protecting chloroplast membranes and characterised by high thermal dissipation of excess light.
• Such adaptive phenomena can affect vegetation dynamics due to possible different species‐specific plant responses, resulting in different plant competitiveness under the limiting conditions of Mediterranean environments.

     

Simultaneous investigation of influenza and enteric viruses in the stools of adult patients consulting in general practice for acute diarrhea

ABSTRACT: BACKGROUND: Gastrointestinal symptoms are not an uncommon manifestation of an influenza virusinfection. In the present study, we aimed to investigate the presence of influenza viruses inthe stools of adult patients consulting their general practitioner for uncomplicated acutediarrhea (AD) and the proportion of concurrent infections by enteric and influenza viruses. METHOD: A case-control study was conducted from December 2010 to April 2011. Stool specimenswere collected and tested for influenza viruses A (seasonal A/H3N2 and pandemic A/H1N1)and B, and for four enteric viruses (astrovirus, group A rotavirus, human enteric adenovirus,norovirus of genogroups I - NoVGI - and genogroup II - NoVGII). RESULTS: General practitioners enrolled 138 cases and 93 controls. Of the 138 stool specimenscollected, 92 (66.7%) were positive for at least one of the four enteric viruses analysed and 10(7.2%) tested positive for one influenza virus. None of these 10 influenza positive patientsreported respiratory symptoms. In five influenza-positive patients (3.6%), we also detectedone enteric virus, with 4 of them being positive for influenza B (2 had co-detection withNoVGI, 1 with NoVGII, and 1 with astrovirus). None of the 93 controls tested positive forone of the enteric and/or other influenza viruses we investigated. CONCLUSIONS: In this study we showed that the simultaneous detection of influenza and enteric viruses is nota rare event. We have also reported, for the first time in general practice, the presence ofseasonal and pandemic influenza viruses in the stools of adult patients consulting foruncomplicated AD. A simultaneous investigation of enteric and influenza viruses in patientscomplaining of gastrointestinal symptoms could be useful for future studies to better identifythe agents responsible for AD.     

Further data on the development of SRIF-like immunoreactive nerve cell populations in the chick embryo brain stem. I. Medulla and pons.

Further immunocytochemical analysis of the neuroblasts with SRIF-like immunoreactivity (ir) was carried out on the chick embryo medulla and pons. 5 or 100 microns rombencephalon sections were obtained from 60 White Leghorn chick embryos at stages (E = Embryonic days) ranging from E4 1/2 to E18 and incubated with rabbit polyclonal antibodies against synthetic cyclic Somatostatin-14, according to PAP-DAB technique. In the medulla and pons the ir appeared as from E12. From E12 to E13 1/2-E14 the ir distribution gradually changed. From E14 to E18 numbers and spatial arrangement of the positive neuroblast groups did not show substantial changes; in these respects the ir distributional pattern proved to be markedly different from the one observed by the Authors in adult animals. Moreover, from E13 to E15 the positive neuroblast density appeared to be higher than that of positive neurons in adults. These results are consistent with a possible SRIF local regulative role.     

Automated high throughput microscale antibody purification workflows for accelerating antibody discovery

To rapidly find “best-in-class” antibody therapeutics, it has become essential to develop high throughput (HTP) processes that allow rapid assessment of antibodies for functional and molecular properties. Consequently, it is critical to have access to sufficient amounts of high quality antibody, to carry out accurate and quantitative characterization. We have developed automated workflows using liquid handling systems to conduct affinity-based purification either in batch or tip column mode. Here, we demonstrate the capability to purify >2000 antibodies per day from microscale (1 mL) cultures. Our optimized, automated process for human IgG1 purification using MabSelect SuRe resin achieves ～70% recovery over a wide range of antibody loads, up to 500 µg. This HTP process works well for hybridoma-derived antibodies that can be purified by MabSelect SuRe resin. For rat IgG2a, which is often encountered in hybridoma cultures and is challenging to purify via an HTP process, we established automated purification with GammaBind Plus resin. Using these HTP purification processes, we can efficiently recover sufficient amounts of antibodies from mammalian transient or hybridoma cultures with quality comparable to conventional column purification.     

Tripping Elicits Earlier and Larger Deviations in Linear Head Acceleration Compared to Slipping

Slipping and tripping contribute to a large number of falls and fall-related injuries. While the vestibular system is known to contribute to balance and fall prevention, it is unclear whether it contributes to detecting slip or trip onset. Therefore, the purpose of this study was to investigate the effects of slipping and tripping on head acceleration during walking. This information would help determine whether individuals with vestibular dysfunction are likely to be at a greater risk of falls due to slipping or tripping, and would inform the potential development of assistive devices providing augmented sensory feedback for vestibular dysfunction. Twelve young men were exposed to an unexpected slip or trip. Head acceleration was measured and transformed to an approximate location of the vestibular system. Peak linear acceleration in anterior, posterior, rightward, leftward, superior, and inferior directions were compared between slipping, tripping, and walking. Compared to walking, peak accelerations were up to 4.68 m/s² higher after slipping, and up to 10.64 m/s² higher after tripping. Head acceleration first deviated from walking 100-150ms after slip onset and 0-50ms after trip onset. The temporal characteristics of head acceleration support a possible contribution of the vestibular system to detecting trip onset, but not slip onset. Head acceleration after slipping and tripping also appeared to be sufficiently large to contribute to the balance recovery response.     

Electromyographic biofeedback training for tension headache in the elderly: a prospective study.

This study evaluated the effects of a 12-session frontal electromyographic biofeedback training regimen on the headache activity of eight tension headache sufferers aged 62 and older. The biofeedback sessions were slightly modified for a geriatric population, essentially to increase comprehension and retention of rationale and instructions. Post-treatment assessment at three months revealed significant decreases in overall headache activity (50% or greater) in 50% of the subjects, and moderate improvement (35%-45%) in three of the remaining four subjects. Significant clinical and/or statistical pre-post differences were also found for the number of headache-free days, peak headache activity, and medication index. This is the first prospective study of biofeedback training for tension headache in an elderly population and, unlike previous retrospective studies, suggests that such therapy may be an effective intervention in the treatment of tension headaches in the elderly.     

Characterization of the cytoskeleton in human normal and otosclerotic osteoblast-like cells.

The localization and distribution of some cytoskeletal protein components were studied by immunostaining methods in normal and ostosclerotic osteoblast-like cells. The protein components investigated were microtubules (beta-tubulin), intermediate filaments (vimentin), microfilaments (actin and myosin) and structural proteins (alpha-actinin and fibronectin). Although the mechanism is not yet clear, the alterations observed in the pathological cells could well play a role in the expression of otosclerosis.