Survival and virulence of Acinetobacter baumannii in microbial mixtures.

Acinetobacter species such as A. venetianus and A. guillouiae have been studied for various biotechnology applications, including bioremediation of recalcitrant and harmful environmental contaminants, as well as bioengineering of enzymes and diagnostic materials. Bacteria used in biotechnology are often combined with other microorganisms in mixtures to formulate efficacious commercial products. However, if the mixture contained a closely related Acinetobacter pathogen such as A. baumannii (Ab), it remains unclear whether the survival and virulence of Ab would be masked or augmented. This uncertainty poses a challenge in ensuring the safety of such biotechnology products, since Ab is one of the most significant pathogens for both hospital and community -acquired infections. This research aimed to investigate the growth and virulence of Ab within a mixture of 11 bacterial species formulated as a mock microbial mixture (MM). Growth challenges with environmental stressors (i.e., temperature, pH, sodium, iron, and antibiotics) revealed that Ab could thrive under diverse conditions except in the presence of ciprofloxacin. When cultured alone, Ab exhibited significantly more growth in the presence of almost all the environmental stressors than when it was co-incubated with the MM. During the exposure of A549 lung epithelial cells to the MM, Ab growth was stimulated compared to that in standard mammalian culture media. Cytotoxicity caused by Ab was suppressed in the presence of the MM. Lymphocytes were significantly reduced in mice exposed to Ab with or without MM via intravenous injection. The levels of the splenic cytokines IL-1α, IL-1ß, MCP-1, and MIP-1α were significantly reduced 24 h after exposure to Ab + MM. This study demonstrated that the presence of the MM marginally but significantly reduced the growth and virulence of Ab, which has implications for the safety of mixtures of microorganisms for biotechnological applications. Furthermore, these findings expand our understanding of the virulence of Ab during host-pathogen interactions.

Hepatotoxicity of Cadmium Telluride Quantum Dots Induced by Mitochondrial Dysfunction.

The aim of this study was to investigate the detailed mechanisms of hepatotoxicity induced by cadmium telluride quantum dots (CdTe-QDs) in BALB/c mice after intravenous injection. The study investigated oxidative stress, apoptosis, and effects on mitochondria as potential mechanistic events to elucidate the observed hepatotoxicity. Oxidative stress in the liver, induced by CdTe-QD exposure, was demonstrated by depletion of total glutathione, an increase in superoxide dismutase activity, and changes in the gene expression of several oxidative stress-related biomarkers. Furthermore, CdTe-QD treatment led to apoptosis in the liver via both intrinsic and extrinsic apoptotic pathways. Effects on mitochondria were evidenced by the enlargement and increase in the number of mitochondria in hepatocytes of treated mice. CdTe-QDs also caused changes in the levels and gene expression of electron transport chain enzymes, depletion of ATP, and an increase in the level of the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), a regulator of mitochondrial biogenesis. The findings from this study suggest that CdTe-QDs-induced hepatotoxicity might have originated from mitochondrial effects which resulted in oxidative stress and apoptosis in the liver cells. This study provides insight into the biological effects of CdT-QDs at the tissue level and the detailed mechanisms of their toxicity in animals. The study also provides important data for bridging the gap between in vitro and in vivo testing and risk assessment of these NPs.

Biodistribution and Systemic Effects in Mice Following Intravenous Administration of Cadmium Telluride Quantum Dot Nanoparticles.

Quantum dots (QDs) are engineered nanoparticles (NPs) of semiconductor structure that possess unique optical and electronic properties and are widely used in biomedical applications; however, their risks are not entirely understood. This study investigated the tissue distribution and toxic effects of cadmium telluride quantum dots (CdTe-QDs) in male BALB/c mice for up to 1 week after single-dose intravenous injections. CdTe-QDs were detected in the blood, lung, heart, liver, spleen, kidney, testis and brain. Most CdTe-QDs accumulated in the liver, followed by the spleen and kidney. At high doses, exposure to CdTe-QDs resulted in mild dehydration, lethargy, ruffled fur, hunched posture, and body weight loss. Histological analysis of the tissues, upon highest dose exposures, revealed hepatic hemorrhage and necrotic areas in the spleen. The sera of mice treated with high doses of CdTe-QDs showed significant increases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin levels, as well as a reduction in albumin. CdTe-QD exposure also led to a reduced number of platelets and elevated total white blood cell counts, including monocytes and neutrophils, serum amyloid A, and several pro-inflammatory cytokines. These results demonstrated that the liver is the main target of CdTe-QDs and that exposure to CdTe-QDs leads to hepatic and splenic injury, as well as systemic effects, in mice. By contrast, cadmium chloride (CdCl2), at an equivalent concentration of cadmium, appeared to have a different pharmacokinetic pattern from that of CdTe-QDs, having minimal effects on the aforementioned parameters, suggesting that cadmium alone cannot fully explain the toxicity of CdTe-QDs.

Phagocytosis-coupled flow cytometry for detection and size discrimination of anionic polystyrene particles.

Flow cytometry was evaluated for its capacity to detect and distinguish a wide size range (20-2000 nm) of fluorescent polystyrene particles (PSPs). Side scatter and fluorescence parameters could predict dispersed PSP sizes down to 200 nm, but the forward scatter parameter was not discriminatory. Confocal microscopy of flow-sorted fractions confirmed that dispersed PSPs appeared as a single sharp peak on fluorescence histograms, whereas agglomerated PSPs were detected as smaller adjacent peaks. Particles as small as 200 nm could also be detected by flow cytometry after they were first phagocytized by J774A.1 murine macrophages. Confocal microscopy demonstrated that these PSPs were internalized within the cytoplasm. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and calcein-AM (acetoxymethyl ester) assays showed that they were not cytotoxic. Internalized PSP size correlated to both cellular side scatter (R(2)=0.9821) and fluorescence intensity (R(2)=0.9993). Furthermore, PSPs of various sizes could be distinguished when J774A.1 cells were loaded with a single size of PSP and mixed with cells containing other sizes. However, spectra of cells loaded with a mixture of PSP sizes resembled those containing only the largest PSP. These data demonstrate the capacity and limitations of phagocytosis-coupled flow cytometry to distinguish between dispersed and agglomerated states and detect a wide size range of particles.

Development of a bead-based aptamer/antibody detection system for C-reactive protein.

A multiplexing bead-based platform provides an approach for the development of assays targeting specific analytes for biomonitoring and biosensing applications. Multi-Analyte Profiling (xMAP) assays typically employ a sandwich-type format using antibodies for the capture and detection of analytes of interest, and the system permits the simultaneous quantitation of multiple targets. In this study, an aptamer/antibody assay for the detection of C-reactive protein (CRP) was developed. CRP is an acute phase marker of inflammation whose elevated basal levels are correlated with an increased risk for a number of pathologies. For this assay, an RNA aptamer that binds CRP was conjugated to beads to act as the capture agent. Biotinylated anti-CRP antibody coupled to fluorescently labeled streptavidin was used for quantification of CRP. The detection limit of the CRP assay was 0.4 mg/L in diluted serum. The assay was then used to detect spiked CRP samples in the range of 0.4 to 10mg/L in diluted serum with acceptable recoveries (extrapolated values of 70-130%), including that of a certified reference material (129% recovery). The successful incorporation of the CRP aptamer into this platform demonstrates that the exploration of other aptamer-target systems could increase the number of analytes measurable using xMAP-type assays.

Review of current methods for characterizing virulence and pathogenicity potential of industrial Saccharomyces cerevisiae strains towards humans.

Most industrial Saccharomyces cerevisiae strains used in food or biotechnology processes are benign. However, reports of S. cerevisiae infections have emerged and novel strains continue to be developed. In order to develop recommendations for the human health risk assessment of S. cerevisiae strains, we conducted a literature review of current methods used to characterize their pathogenic potential and evaluated their relevance towards risk assessment. These studies revealed that expression of virulence traits in S. cerevisiae is complex and depends on many factors. Given the opportunistic nature of this organism, an approach using multiple lines of evidence is likely necessary for the reasonable prediction of the pathogenic potential of a particular strain. Risk assessment of S. cerevisiae strains would benefit from more research towards the comparison of virulent and non-virulent strains in order to better understand those genotypic and phenotypic traits most likely to be associated with pathogenicity.

Semi-automated water sampling module for repeated sampling and concentration of Bacillus cereus group spores.

Monitoring the presence of pathogenic Bacillus spores is important for industrial applications, as well as necessary for ensuring human health. Bacillus thuringiensis is used as a biopesticide against several insect pests. Bacillus cereus spores are a significant cause of food poisoning, and Bacillus anthracis is a recognized biosecurity threat. Laboratory-based methods, such as polymerase chain reaction, enzyme-linked immunosorbent assay, or matrix-assisted laser desorption ionization spectroscopy provide sensitive detection of bacteria and spores, but the application of those methods for quasi-continuous environmental monitoring presents a significant challenge requiring frequent human intervention. To address this challenge, we developed a workstation for quasi-autonomous monitoring of water reservoirs for the presence of bacteria and spores, and designed and validated the functionality of a microprocessor-controlled module capable of repetitive collection and pre-concentration of spores in liquid samples tested with fiberglass (FG), polyether sulfone and polyvinylidene fluoride filters. The best results were obtained with FG filters delivering a 20× concentration of B. thuringiensis and B. cereus spores from saline suspensions. The successful 20× pre-concentration of Bacillus spores demonstrated with FG filters could be repeated up to 3 times when bleach decontamination is applied between filtrations. Taken together, our results demonstrate an attractive instrument suitable for semi-automated, quasi-continuous sampling and pre-processing of water samples for biosensing of bacterial spores originating from a complex environment.

Genomic and functional analysis of Vibrio phage SIO-2 reveals novel insights into ecology and evolution of marine siphoviruses.

We report on a genomic and functional analysis of a novel marine siphovirus, the Vibrio phage SIO-2. This phage is lytic for related Vibrio species of great ecological interest including the broadly antagonistic bacterium Vibrio sp. SWAT3 as well as notable members of the Harveyi clade (V.harveyi ATTC BAA-1116 and V.campbellii ATCC 25920). Vibrio phage SIO-2 has a circularly permuted genome of 80598 bp, which displays unusual features. This genome is larger than that of most known siphoviruses and only 38 of the 116 predicted proteins had homologues in databases. Another divergence is manifest by the origin of core genes, most of which share robust similarities with unrelated viruses and bacteria spanning a wide range of phyla. These core genes are arranged in the same order as in most bacteriophages but they are unusually interspaced at two places with insertions of DNA comprising a high density of uncharacterized genes. The acquisition of these DNA inserts is associated with morphological variation of SIO-2 capsid, which assembles as a large (80 nm) shell with a novel T=12 symmetry. These atypical structural features confer on SIO-2 a remarkable stability to a variety of physical, chemical and environmental factors. Given this high level of functional and genomic novelty, SIO-2 emerges as a model of considerable interest in ecological and evolutionary studies.

Impact of COVID-19 pandemic on psychological wellbeing of Oncology clinicians in the Middle East and North Africa (MENA) region.

OBJECTIVE: The reorganization of cancer services and the increased work burden on health care providers during the COVID-19 pandemic are likely to be associated with significant negative psychological impact. The aim of this study is to evaluate the impact of COVID-19 pandemic on the psychological well-being of oncology clinicians in the Middle East and North Africa (MENA) region. MATERIALS AND METHODS: We randomly invited 1500 oncology clinicians including medical oncologists, clinical oncologists, radiation oncologists and surgical oncologists from 17 countries in the MENA region to complete a web-based survey to determine the level of psychological stress during the COVID-19 pandemic from October 2020 to January 2021. The questionnaire was based on the Perceived Stress Scale (PSS), Generalized Anxiety Disorders Scale (GAD-7) and WHO Well-being Index (WHO-5). The data was analyzed using SPSS version 21 and the difference between groups was measured by t-test and ANOVA. RESULTS: Overall, 520 (35%) clinicians including 368 (71%) males and 152 (29%) females participated in the survey with 247 (47%) participants between the ages of 36 to 45 years. Average score of 29.6 for males and 30.2 on PSS-10, indicative of high-perceived stress in both the genders. Compared to males, females had significantly higher anxiety levels on GAD-7 scale (p=.04), but this difference in stress level and well-being was not observed on PSS-10 (p=.134) and WHO -5 well-being index (p=.709). Clinicians of age 25-35 years had significantly higher anxiety levels on GAD-7 scale (p=.004) and higher stress on PSS (p=.000) as compared to other age groups. Age over 55 years was associated with lower levels of anxiety and stress on GAD-7 and PSS. Oncology clinicians working in public sector experienced significantly lower stress as compared to private sector on PSS scale (p=.041). CONCLUSIONS: Anxiety and stress levels among oncology clinicians have significantly increased in COVID-19 pandemic in the MENA region. Females and young clinicians had higher anxiety and stress, while oncology clinicians over the age of 55 years and working in the public sector reported less stress and anxiety. The general wellbeing of clinicians was well preserved even in a highly stressful and anxious situation.

Rapid, Sensitive, and Selective Quantification of Bacillus cereus Spores Using xMAP Technology.

Bacillus cereus is a spore-forming ubiquitous bacterium notable as a food poisoning agent. Detection of B. cereus spores using selective media is laborious and non-specific. Herein, the quantitative detection of B. cereus spores was investigated with commercial antibodies and published aptamer sequences. Several detection reagents were screened for affinity to Bacillus collagen-like protein A (BclA), an abundant exosporium glycoprotein. Sensitivity and selectivity toward B. cereus spores were tested using immunoassays and multi-analyte profiling (xMAP). A recombinant antibody developed in llama against BclA protein showed B. cereus spore selectivity and sensitivity between 102 and 105 spores/mL using xMAP. DNA aptamer sequences demonstrated sensitivity from 103 to 107 spores/mL and no cross-reaction to B. megaterium and B. subtilis. Selectivity for B. cereus spores was also demonstrated in a mixture of several diverse microorganisms and within a food sample with no compromise of sensitivity. As proof of concept for multiplexed measurement of human pathogens, B. cereus and three other microorganisms, E. coli, P. aeruginosa, and S. cerevisiae, were simultaneously detected using xMAP. These data support the development of a rapid, sensitive, and selective system for quantitation of B. cereus spores and multiplexed monitoring of human pathogens in complex matrices.

Strategies for capturing Bacillus thuringiensis spores on surfaces of (001) GaAs-based biosensors.

Bacillus thuringiensis (Bt) is used as a bioinsecticide since it effectively kills insect larvae. Bt is also genetically similar to Bacillus cereus (Bc), a well recognized foodborne human pathogen; they are both members of the Bacillus cereus group (BC group). Although approved Bt bioinsecticide products have been confirmed to be non-pathogenic to humans, close monitoring of Bt during dissemination is important for cost considerations and to limit impact on biodiversity towards nontarget organisms. As such, developing rapid, sensitive, and specific tools for quantitative detection of Bt spores during and following spray operations is highly desirable. The goals of this study were to investigate commercially available detection reagents for sensitivity and selectivity in detecting Bt spores, and then functionalize a surface of (001) GaAs used in photonic biosensing. To achieve these goals, we (1) screened commercial antibodies for their capacity to bind recombinant proteins from Bt spores, (2) screened antibodies and aptamers for their sensitivity and selectivity against Bt spores, and (3) tested the efficiency of selected antibodies and aptamers in capturing Bt spores on the surface of functionalized GaAs biochips. Seven genes encoding Bt spore proteins were cloned and expressed in Escherichia coli. The binding of each purified spore antigen was tested by commercially available polyclonal and monoclonal antibodies claimed to exclusively target spores. Of the seven targets, Bacillus collagen-like protein A, was the most abundant protein on Bt spores and demonstrated the strongest binding affinity to all test antibodies. The commercial antibodies (Abs) were also tested for specificity to BC Group versus non-BC Group spores. Three of six commercial antibodies showed selectivity to Bt spores, with recombinant Abs providing the most robust lower range of detection (102 to 6 × 103 spores/mL). The sensitivity and selectivity of three published DNA aptamer sequences demonstrated a wide range of detection sensitivity for Bt spores. Two of the three test aptamers also showed reasonable selectivity towards Bt spores while the third demonstrated reactivity to non-BC Group B. megaterium and B. subtilis. Of the reagents tested, a thiolated aptamer and llama recombinant Ab showed highest Bt spore capture efficiency as measured by spore coverage of the GaAs surface. These results confirm that the selected aptamer and llama rAb can be considered strong candidates for the development of GaAs-based biosensing devices.

Selective Detection of Legionella pneumophila Serogroup 1 and 5 with a Digital Photocorrosion Biosensor Using Antimicrobial Peptide-Antibody Sandwich Strategy.

Rapid detection of Legionella pneumophila (L. pneumophila) is important for monitoring the presence of these bacteria in water sources and preventing the transmission of the Legionnaires' disease. We report improved biosensing of L. pneumophila with a digital photocorrosion (DIP) biosensor functionalized with an innovative structure of cysteine-modified warnericin antimicrobial peptides for capturing bacteria that are subsequently decorated with anti-L. pneumophila polyclonal antibodies (pAbs). The application of peptides for the operation of a biosensing device was enabled by the higher bacterial-capture efficiency of peptides compared to other traditional ligands, such as those based on antibodies or aptamers. At the same time, the significantly stronger affinity of pAbs decorating the L. pneumophila serogroup-1 (SG-1) compared to serogroup-5 (SG-5) allowed for the selective detection of L. pneumophila SG-1 at 50 CFU/mL. The results suggest that the attractive sensitivity of the investigated sandwich method is related to the flow of an extra electric charge between the pAb and a charge-sensing DIP biosensor. The method has the potential to offer highly specific and sensitive detection of L. pneumophila as well as other pathogenic bacteria and viruses.

Short Ligand, Cysteine-Modified Warnericin RK Antimicrobial Peptides Favor Highly Sensitive Detection of Legionella pneumophila.

Culture-based methods for the detection of Legionella pneumophila are prohibitively slow and frequently inadequate. The problem has been addressed with biosensing technology that employs a variety of ligands for the specific capture of bacteria. However, the limited success of the application of mammalian antibodies, aptamers, and nucleic acid-based probes for sensitive biosensing has generated growing interest in exploring alternative biosensing architectures, such as those based on antimicrobial peptides (AMP) that are known for their attractive therapeutic applications. We report on the successful employment of cysteine-modified warnericin RK AMP for the operation of a highly sensitive biosensor of L. pneumophila based on digital photocorrosion of GaAs/AlGaAs nanoheterostructures. The replacement of the relatively cumbersome procedure commonly applied for the attachment of antibodies to COOH-terminated mercaptohexadecanoic acid self-assembled monolayers has allowed for a significant reduction in the distance at which bacteria are immobilized above the biosensor surface. An important consequence of this approach is the attractive limit of detection of L. pneumophila estimated at 2 × 102 CFU/mL. The target bacteria were captured four times more efficiently than P. fluorescens, B. subtilis, and E. coli, which is highly promising for environmental monitoring.

Interactive effects of threonine levels and protein source on growth performance and carcass traits, gut morphology, ileal digestibility of protein and amino acids, and immunity in broilers.

An experiment was executed to test the hypothesis that supplementation of dietary threonine (d-Thr), above NRC recommendation to diets containing poorly digestible protein source (PS) may compensate its detrimental effects on overall performance of broilers. In total, nine hundred 1-day-old mixed sex broilers (Ross-308) were randomly distributed over 6 (2 × 3) experimental diets comprising 5 replicates of 30 broilers each for 35 d. The experimental diets contain either soybean meal (SBM) or canola meal (CM) with 3 levels (100, 110, and 120% of NRC recommendation) of d-Thr. During the course of the trial (0 to 35 D), interactions (P < 0.05) between PS and d-Thr were observed for feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), carcass, and gut health parameters. The broilers fed recommended level (100%) of d-Thr had 7 and 5% poorer FCR compared with those fed diets with 110 and 120% d-Thr, respectively. For villus height (VH), an interaction (P = 0.007) was found between PS and d-Thr level. Broilers consuming SBM diets had 22% longer villi, 10% deeper crypts, and 30% greater VH to crypt depth ratio (VCR) compared to those fed CM. The broilers fed 110% d-Thr diets had 9% lower crypt depth (CD) and 15% greater VCR compared with those fed diets containing NRC recommended levels. CM resulted in 9% lower protein digestibility with lower (P < 0.05) of some AA, whereas it was improved by 7% in broilers fed 120% d-Thr supplemented diets. The bursa and spleen weights were positively affected (P < 0.001) by PS. Threonine supplementation (10%) resulted in 25% greater thymus, 18% heavier bursa, and 30% greater infectious bursal disease titer. In conclusion, supplementation of d-Thr, above NRC recommendation, resulted in a better growth performance and carcass traits, improved ileal digestibility of protein and amino acids, better gut health, and immunity in broilers.

Bacterial 5-nucleotidase in aquatic ecosystems: a novel mechanism of phosphorus regeneration.

Zooplankton excretion and algal alkaline phosphatase are presumed to be responsible for phosphorus recycling in aquatic ecosystems; the role of bacteria has been unclear. High levels of bacterial cell-surface 5-nucleotidase were discovered in samples of picoplankton from California coastal waters. 5-Nucleotidase rapidly generated orthophosphate from 5-nucleotide added in nanomolar amounts and could supply half the orthophosphate required by plankton. Unlike alkaline phosphatase, 5-nucleotidase was not inhibited by orthophosphate at any concentration found in aquatic environments. Initial results indicate even greater 5-nucleotidase activity in fresh water (Lake Hodges, California) and brackish water (Baltic). Release and uptake of orthophosphate were tightly coupled.

Occurrence and metabolic activity of organisms under the ross ice shelf, antarctica, at station j9.

Seawater samples below the Ross Ice Shelf were collected through an access hole at J9, approximately 400 kilometers from the Ross Sea, Antarctica. The 237-meter water column had sparse populations of bacteria (8.7 x 10(6) to 1.2 x 10(7) per liter), microplankters (10(2) to 10(3) per cubic meter), and zooplankters (10 to 20 per cubic meter) at the depths studied. Microbial biomass estimates from cellular adenosine 5'-triphosphate measurements were very low (10 to 150 nanograms of carbon per liter), comparable with values for the abyssal ocean. Microbial populations assimilated tritiated D-glucose, thymidine, uridine, and adenosine triphosphate at extremely low rates, comparable with deep-sea heterotrophic populations. Sediment samples had 10(7) to 10(8) bacteria per gram (dry weight), which were metabolically active as shown by respiration of uniformly labeled D-[(14)C]glucose. From this study it cannot be determined whether these organisms in the water column and sediments constitute a functioning food web.

Adenosine A2A receptor antagonists as novel anti-Parkinsonian agents: a review of structure-activity relationships.

The adenosine A2A receptor (AA2AR) has emerged as an attractive target for the treatment of Parkinson's disease. Evidence suggests that antagonists of the AA2AR may be neuroprotective and may help to alleviate the symptoms of Parkinson's disease. During last decade, many efforts have been accomplished searching potent and selective AA2AR antagonists. In this field, various xanthines and non-xanthine heterocyclic compounds of monocyclic, bicyclic and tricyclic nucleus possessing very good affinity with a broad range of selectivity have been proposed. The aim of this article is to summarize available data on different chemical classes of AA2AR antagonists including those in clinical development, and briefly present an overview of the structure-activity relationships found for these compounds.

Exploring nutritive profile, metabolizable energy, protein, and digestible amino acids contents of indigenous protein sources of different locations for male broilers.

2 experiments were conducted to explore nutrient composition, AME, AMEn, standardized ileal digestibility (SID) of CP, and amino acids (AA) of 4 indigenous protein sources including canola meal (CM), rapeseed meal (RSM), guar meal (GM), and sunflower meal (SFM) collected from 2 different locations, Multan (MUL; n = 3) and Sukkur (SKR; n = 3), of Pakistan. Higher (P < 0.05) dry matter (DM), CP, and gross energy (GE), whereas lower (P < 0.05) ash contents were found in SKR, CM, and RSM compared with those from MUL. The MUL GM had higher (P < 0.05) crude fiber (CF) and CP, whereas lower (P < 0.05) GE compared with those from SKR. The SFM from MUL had higher DM, whereas lower CF and CP contents than SKR. In the first experiment, 216 21-d-old male broilers (Ross 308) were distributed over 8 test diets (4 ingredients × 2 locations) and 1 basal diet, with 4 replicates containing 6 birds each (9 × 4 × 6), in a complete randomized design to determine AME and AMEn. The results indicated higher (P < 0.05) AME and AMEn in MUL CM than SKR. In the second experiment, 216 21-d-old male broilers (Ross 308) were raised in 36 cages (6 birds each) to determine SID of CP and AA in a complete randomized design. 8 test diets (4 ingredients × 2 locations) and a protein-free diet, with 4 replicates each, were tested. The SID of CP and some AA were higher (P < 0.05) in MUL CM and RSM than SKR. The SKR GM had a higher (P < 0.05) SID of CP, arginine, methionine, threonine, valine, and cysteine compared with that from MUL. The SFM from MUL had higher (P < 0.05) SID of CP, arginine, histidine, methionine, valine, alanine, aspartate, cysteine, and serine than SKR. In conclusion, major differences do exist between CM, GM, RSM, and SFM from different locations in terms of nutrients, AME, digestible CP, and AA contents for male broilers.

[Femoral neck fractures in patients over 50 years old]. / Les fractures du col du fémur après 50 ans.

INTRODUCTION: Despite many papers and instructional course lectures, therapeutic guidelines are not clearly defined about treatment of femoral neck fractures. The aim of this multicentric French symposium was to prospectively study the results of current therapeutic options in order to propose scientifically proven options. MATERIAL AND METHODS: Three prospective studies were carried out in order to answer to these questions: (1) is it possible with anatomical reduction and stable fixation to lower the non union and osteonecrosis rate? (2) is functional treatment of Garden 1 fractures successful in more than 65 years patients? (3) what criteria are useful to choose the kind of arthroplasty for more than 65 years patients? RESULTS: For the 64 patients between 50 and 65 years old included in the first study, 44 ORIF and 17 prostheses were performed. No open reduction was performed in this series despite a 34% malreduction rate. The risk for displacement after functional treatment of Garden 1 fractures is 31%. For patients over 65 years old, almost fractures are treated in this series by an arthroplasty. The one-year mortality rate after displaced femoral neck fracture was 17%. Functional results were better in total hip prosthesis group than in bipolar or unipolar group. Non cemented stems were not safer than cemented ones in frail patients. DISCUSSION AND CONCLUSIONS: For young patients, ORIF should be the treatment of choice: the initial displacement and its effects on the femoral head vascularisation, the quality of reduction and fixation are the two most significant factors for good outcome. For Garden 1, fractures in patients 65 years old or more, it is proposed to performed an internal fixation despite in two thirds of the cases, it should be unnecessary because non identification of predictive factors of failure. For patients over 65 years old, the type of arthroplasty to perform in displaced fractures is to be chosen according to the preoperative mobility and comorbidities. Because of acetabular erosion with long-term follow-up, it is clearly indicated to perform total hip replacement for patients with life expectancy of 10 years or more. For frail patients, unipolar arthroplasty is the best option. The place for bipolar or uncemented implants is not yet well-defined and more prospective trials are needed. In this multicentric study, results appear quite different in terms of mortality, or functional status. These differences seem to be related to technical choice, geriatric care, nutritional consideration or surgical organisation, all factors that may be of major importance for prognostic.