Debridement, antibiotics and implant retention (DAIR): An effective treatment option for early prosthetic joint infections.

INTRODUCTION: Debridement, antibiotics and implant retention (DAIR) is an attractive treatment option for prosthetic joint infections (PJIs). However, reported success rates and predictors of DAIR failure vary widely. The primary aim of this study is to report the outcome of DAIR in patients with hip and knee PJIs receiving short course of antibiotic therapy. The secondary aim is to identify risk factors for DAIR failure. METHODS: We performed a retrospective analysis of prospectively collected data of all hip and knee PJIs consecutively diagnosed at Quadrante Orthopedic Center, an Italian orthopedic hospital highly specialized in prosthetic surgery, from January 1, 2013 to January 1, 2019, and we analyzed those treated with DAIR. RESULTS: Forty-seven PJIs occurred after 5102 arthroplasty procedures. Twenty-one patients (45%) aged 71 years were treated with DAIR for hip (62%) and knee (38%) PJIs. These were classified as early PJIs in 76% cases, delayed in 19% and late in 5%. Median time from PJI-related symptoms onset to implant revision surgery was 12 days (IQR, 7-20 days). The median duration of antibiotic treatment after surgery was 63 days (IQR, 53-84 days). Sixteen (76%) patients were cured after a median follow-up of 2197 days (IQR, 815-2342 days), while 5 (24%) experienced failure. At multivariate analysis, delayed/late PJIs were significantly associated with failure (OR = 12.51; 95% CI 1.21-129.63, p = 0.03). CONCLUSIONS: DAIR represents an effective strategy for the treatment of early PJIs in spite of short course of antibiotic therapy.

SiGe layer thickness effect on the structural and optical properties of well-organized SiGe/SiO2 multilayers.

In this work, we report on the production of regular (SiGe/SiO2)20 multilayer structures by conventional RF-magnetron sputtering, at 350 °C. Transmission electron microscopy, scanning transmission electron microscopy, raman spectroscopy, and x-ray reflectometry measurements revealed that annealing at a temperature of 1000 °C leads to the formation of SiGe nanocrystals between SiO2 thin layers with good multilayer stability. Reducing the nominal SiGe layer thickness (t SiGe) from 3.5-2 nm results in a transition from continuous SiGe crystalline layer (t SiGe ∼ 3.5 nm) to layers consisting of isolated nanocrystals (t SiGe ∼ 2 nm). Namely, in the latter case, the presence of SiGe nanocrystals ∼3-8 nm in size, is observed. Spectroscopic ellipsometry was applied to determine the evolution of the onset in the effective optical absorption, as well as the dielectric function, in SiGe multilayers as a function of the SiGe thickness. A clear blue-shift in the optical absorption is observed for t SiGe ∼ 2 nm multilayer, as a consequence of the presence of isolated nanocrystals. Furthermore, the observed near infrared values of n = 2.8 and k = 1.5 are lower than those of bulk SiGe compounds, suggesting the presence of electronic confinement effects in the nanocrystals. The low temperature (70 K) photoluminescence measurements performed on annealed SiGe/SiO2 nanostructures show an emission band located between 0.7-0.9 eV associated with the development of interface states between the formed nanocrystals and surrounding amorphous matrix.

Metabolic adaptation and reticuloruminal pH in periparturient dairy cows experiencing different lipolysis early postpartum.

Metabolic adaptation includes an array of concerted metabolic and endocrine events that enable dairy cows bridging the period of energy deficit at the onset of lactation. The present study evaluated metabolic, endocrine and reticuloruminal pH changes in 30 (25 Holstein and five Simmental) periparturient dairy cows experiencing variable lipolysis early postpartum. Cows were fed the same close-up and fresh lactation diets and kept in the same management conditions. Blood samples were collected at day 14, and day 4, relative to expected parturition, and at day 2, and day 21 postpartum, and serum metabolites and hormones related to glucose and lipid metabolism, as well as concentrations of several liver enzymes and acute phase proteins were determined. Additionally, reticuloruminal pH was monitored every 10 min over the last 3 days of the observation period. BW and milk yields were recorded and balances of energy and protein were assessed. Based on serum concentration of non-esterified fatty acids (NEFA) postpartum, cows were retrospectively classified into low (n=8), medium (n=11), and high (n=11) lipolysis groups, with NEFA levels of 0.7 mmol/l, respectively. Overall, elevated NEFA concentrations in the High group went along with a higher ratio of NEFA to cholesterol and reduced insulin sensitivity. While serum glucose, energy deficit and BW loss did not differ, cows of the High group exhibited increased lactate concentrations in the serum, compared with the Medium group. No differences in liver enzymes and acute phase proteins were evidenced among fat mobilization groups, whereas concentration of serum billirubin was lowest in the Low group after parturition. Data of milk yield and milk energy output showed no differences among groups, despite divergences in calculated energy balance and BW change postpartum. Cows of the Low group tended to increase dry matter intake but also showed longer time duration of pH below 6.0 in the reticulorumen (on average 299 min/day compared with 99 and 91 min/day for Medium and High groups, respectively). Differences in metabolic, endocrine and reticuloruminal pH responses indicate diverse metabolic adaptation strategies of early-lactation cows to cope with energy deficit postpartum.

Metabolic responses, performance, and reticuloruminal pH of early-lactating cows fed concentrates treated with lactic acid, with or without inorganic phosphorus supplementation.

Recent data indicate beneficial effects of treating grains with lactic acid (LA) in alleviating the need for inorganic phosphorus supplementation during ruminal fermentation in vitro. The aim of this study was to evaluate the effects of feeding concentrates treated with LA with or without inorganic phosphorus supplementation on feed intake, performance, blood variables, and reticuloruminal pH in dairy cows. A total of 16 early-lactating cows (12 Simmental and 4 Brown Swiss) were included in this study from d 1 until d 37 postpartum. Cows were fed 3 total mixed rations differing in supplementation of inorganic phosphorus and treatment of concentrates. The control (CON) and LA (+P) diets included a concentrate mixture containing 0.8% monocalcium phosphate, and the LA (-P) diet contained no inorganic phosphorus source. The concentrates of the LA (+P) and LA (-P) diets were treated with 5% LA for 24h before feeding, and the concentrate of the CON diet was not treated. Dry matter intake and milk yield were recorded daily, and milk composition and blood variables were determined on several occasions during the trial. Reticuloruminal pH was measured using indwelling sensors that allowed for continuous measurement during the experimental period. Data showed depressed dry matter intake in cows receiving LA-treated concentrates, but milk yield, body weight, and body weight changes remained similar among treatment groups. Cows receiving the LA-treated diets had lower concentrations of serum nonesterified fatty acids, cholesterol, and insulin, and they tended to have higher serum phosphorus levels. On the other hand, reticuloruminal pH was lower and duration of the pH being <6.0 was longer in cows in the LA-treated groups. Aspartate aminotransferase, gamma-glutamyltransferase, and concentrations of bilirubin and bile acids were lower in the LA (-P) group. Taken together, the 5% LA-treated diet without inorganic phosphorus supplementation did not exert any negative effects on performance. The observed beneficial effects on blood metabolites related to lipid metabolism, insulin sensitivity, and liver variables, as well as the tendency for greater systemic phosphorus circulation, suggest that diets including concentrates treated with 5% LA may allow for savings of inorganic phosphorus supplementation in dairy cows. Treatment with 5% LA enhanced cows' risk of developing subacute rumen acidosis, although this condition showed no adverse effects with respect to liver variables and the inflammatory response.

Peripartal changes in reticuloruminal pH and temperature in dairy cows differing in the susceptibility to subacute rumen acidosis.

The present study aimed to investigate changes in the reticuloruminal pH and temperature dynamics in periparturient dairy cows. Reticuloruminal pH and temperature measurements were conducted from 7 d before until 8 d after parturition using indwelling sensors. Nine Simmental and 4 Brown Swiss dairy cows were fed a close-up total mixed ration (52.5% neutral detergent fiber, 5.68MJ of net energy for lactation per kg of dry matter) with additional 1kg/cow per d concentrate mixture (29.5% neutral detergent fiber and 6.25MJ of net energy for lactation per kg of dry matter), starting from 2 wk before the estimated calving date. Postpartum, all cows had free access to the same close-up diet and were gradually fed increasing amounts of a concentrate-rich total mixed ration for early-lactation cows (32.7% neutral detergent fiber, 7.22MJ of net energy for lactation per kg of dry matter). Data showed depressed reticuloruminal pH early postpartum, but only in the group of cows defined as subacute ruminal acidosis (SARA) susceptible (n=8), which had a higher duration time of pH <5.8 (753±82min/d) compared with SARA-tolerant cows (n=5; 15±6min/d). Also, compared with SARA-tolerant cows (112±91min/d), the SARA-susceptible group showed longer (1,049±75min/d) duration time of pH <6.0. When compared by breed, mean reticuloruminal pH tended to be lower in Simmental (6.16±0.03) than in Brown Swiss cows (6.25±0.05), but no differences were observed in the duration of pH <5.8 between breeds. Simmental cows produced more milk (30.4±1.2kg/d) compared with Brown Swiss cows (27.9±1.3kg/d). Neither total dry matter intake nor milk yield were different between SARA-susceptible and SARA-tolerant groups. However, SARA-tolerant cows consumed greater amounts of the close-up total mixed ration than their SARA-susceptible counterparts, whereas no difference was observed in the intake of the early-lactating total mixed ration between the groups. Reticuloruminal temperature was not affected by breed or SARA susceptibility. Interestingly, the mean reticuloruminal temperature and the time duration of temperature >39.5°C abruptly dropped from d 2 to 1 before calving by 0.35°C and 430min/d, respectively. In conclusion, the strong inter-animal variation in reticuloruminal pH responses suggests the need for more careful monitoring and differentiated feeding management of cows during the transition period, whereby the SARA-susceptible cows may require particular attention regarding feeding management and diet composition. The abrupt decrease in reticuloruminal temperature the day before parturition may enable this noninvasive method as a management tool for prediction of parturition time.

Microbial populations and fermentation profiles in rumen liquid and solids of Holstein cows respond differently to dietary barley processing.

AIMS: To evaluate the effects of treating barley grain with lactic acid (LA) and heat on postprandial dynamics of 19 microbial taxa and fermentation in the rumen of dairy cows. METHODS AND RESULTS: This study was designed as a double 3 × 3 Latin square with six rumen-cannulated cows and three diets either containing untreated control barley or barley treated with 1% LA and 1% LA and heat (LAH, 55°C). Microbial populations, pH and volatile fatty acids were assessed in rumen liquid and solids during the postprandial period. Propionate increased and butyrate decreased in rumen solids of cows fed LA and LAH treated barley compared to the control barley. The LA but not LAH treatment depressed Fibrobacter succinogenes in rumen liquid and solids, whereas the opposite effect was observed for Ruminococcus albus in both fractions and Ruminococcus flavefaciens in rumen solids. LA promoted Ruminobacter amylophilus with the effect being more pronounced with LAH. The Lactobacillus group and Megasphaera elsdenii increased in both fractions with LA but not with LAH. CONCLUSIONS: LA and LAH treatment of barley differently altered ruminal abundance of certain bacterial taxa and fungi and increased propionate fermentation in rumen solids, whereby LA and LAH effects were consistent and mostly independent of the rumen fraction and time after barley feeding. SIGNIFICANCE AND IMPACT OF THE STUDY: Results provided evidence that LA and LAH treatment of barley can enhance rumen propionate fermentation without adversely affecting rumen pH. As propionate is the major contributor to gluconeogenesis in ruminants, the present barley treatment may have practical application to enhance energy supply in dairy cows.

Treatment of grain with organic acids at 2 different dietary phosphorus levels modulates ruminal microbial community structure and fermentation patterns in vitro.

Recent data indicate positive effects of treating grain with citric (CAc) or lactic acid (LAc) on the hydrolysis of phytate phosphorus (P) and fermentation products of the grain. This study used a semicontinuous rumen simulation technique to evaluate the effects of processing of barley with 50.25 g/L (wt/vol) CAc or 76.25 g/L LAc on microbial composition, metabolic fermentation profile, and nutrient degradation at low or high dietary P supply. The low P diet [3.1g of P per kg of dry matter (DM) of dietary P sources only] was not supplemented with inorganic P, whereas the high P diet was supplemented with 0.5 g of inorganic P per kg of DM through mineral premix and 870 mg of inorganic P/d per incubation fermenter via artificial saliva. Target microbes were determined using quantitative PCR. Data showed depression of total bacteria but not of total protozoa or short-chain fatty acid (SCFA) concentration with the low P diet. In addition, the low P diet lowered the relative abundance of Ruminococcus albus and decreased neutral detergent fiber (NDF) degradation and acetate proportion, but increased the abundance of several predominantly noncellulolytic bacterial species and anaerobic fungi. Treatment of grain with LAc increased the abundance of total bacteria in the low P diet only, and this effect was associated with a greater concentration of SCFA in the ruminal fluid. Interestingly, in the low P diet, CAc treatment of barley increased the most prevalent bacterial group, the genus Prevotella, in ruminal fluid and increased NDF degradation to the same extent as did inorganic P supplementation in the high P diet. Treatment with either CAc or LAc lowered the abundance of Megasphaera elsdenii but only in the low P diet. On the other hand, CAc treatment increased the proportion of acetate in the low P diet, whereas LAc treatment decreased this variable at both dietary P levels. The propionate proportion was significantly increased by LAc at both P levels, whereas butyrate increased only with the low P diet. Treatments with CAc or LAc reduced the degradation of CP and ammonia concentration compared with the control diet at both P levels. In conclusion, the beneficial effects of CAc and LAc treatment on specific ruminal microbes, fermentation profile, and fiber degradation in the low P diet suggest the potential for the treatment to compensate for the lack of inorganic P supplementation in vitro. Further research is warranted to determine the extent to which the treatment can alleviate the shortage of inorganic P supplementation under in vivo conditions.

Long-term reticuloruminal pH dynamics and markers of liver health in early-lactating cows of various parities fed diets differing in grain processing.

The present study aimed to investigate the long-term effect of feeding barley grain steeped in lactic acid (La) with or without thermal treatment on reticuloruminal pH dynamics and metabolic activity of the liver in 12 primiparous and 18 multiparous early-lactating dairy cows. All cows were included on d 21 postpartum and sampled until d 90 postpartum. Cows were fed a diet based on differently processed ground barley grain: untreated grain (control diet, CON), or grain treated with 1% La alone for 24 h before feeding (La), or with an additional oven-heating at 55°C for 12 h (LaH). The reticuloruminal pH and temperature were measured via indwelling sensors that allowed for continuous (every 10min) and long-term measurement from d 21 to 80 postpartum. Blood samples were taken on d 21, 40, and 90 of lactation and analyzed for liver enzymes aspartate aminotransferase (AST), gamma-glutamyltransferase, and glutamate dehydrogenase, as well as bilirubin, bile acids, and serum amyloid A. Dry matter intake was higher in multiparous cows (20.7±0.27 kg/d) compared with primiparous cows (18.2±0.33 kg/d), but was not affected by dietary treatment. Overall, the relatively short duration (51±5min/d) of reticuloruminal pH <5.8 suggests low risk of subacute ruminal acidosis throughout the experiment. Results indicated that La treatment of barley, with or without heat, lowered the time duration of pH <5.8 compared with CON, but only in primiparous cows (from 118±13 to 46±11 and 25±11min/d for CON, La, and LaH, respectively). In multiparous cows, the opposite effect of feeding the La-treated barley on time duration of pH <5.8 (11±8 vs. 46±9 vs. 57±9min/d for CON, La, and LaH, respectively) was observed. Multiparous cows generally showed higher pH readings and shorter periods in which the ruminal pH dropped below the threshold of pH 5.8. The reticuloruminal temperature was not affected by dietary treatment, whereas parity affected the time duration of reticuloruminal temperature >39.5°C, being 60±19min/d shorter in primiparous cows. The measured activities of the liver enzymes AST, gamma-glutamyltransferase, and glutamate dehydrogenase, as well as bilirubin, bile acids, and the acute phase protein serum amyloid A, were not affected by grain feeding. Additionally, only one small effect of parity on investigated serum variables was noticed, showing slightly but significantly higher values of AST in multiparous (80.5±1.4 U/L) compared with primiparous cows (76.0±1.7 U/L). In conclusion, our results indicate greater risk for primiparous cows to develop subacute ruminal acidosis-like conditions during early lactation than multiparous cows. The study also suggests limited benefits of feeding processed barley grain with La with or without thermal treatment to modulate ruminal tolerance of grain feeding, whereby differing effects in primiparous cows were observed compared with multiparous cows.

Efficacy of daptomycin lock therapy in the treatment of bloodstream infections related to long-term catheter.

BACKGROUND: Concomitant systemic and intracatheter antibiotic therapy is a therapeutic option for catheter-related bloodstream infections (CRBSI) in patient fitted with long-term intravenous central catheters. CRBSI are mainly caused by Gram-positive bacteria. Daptomycin (DPT) is an antibiotic active against Gram-positive bacteria with high bactericidal activity and good biofilm penetration. OBJECTIVE: To study the efficacy of DPT given systemically and as lock therapy in the treatment of CRBSI. MATERIALS AND METHODS: A retrospective review was conducted of adult patients with a long-term central venous catheter (CVC) receiving both systemic intravenous and intracatheter lock therapy for CRBSI. The primary outcome was catheter maintenance, following clinical success and microbiological eradication. RESULTS: Eight patients who had failed previous standard therapy (vancomycin 7, cefazolin 1) were included in the study. In all but one, coagulase-negative staphylococci were repeatedly isolated. The other patient had enterococcal infection. DPT, given intravenously and as lock therapy, was successful in six of eight cases. The mean time to negative blood cultures was 2 days (range 1-6). In two cases neither clinical nor microbiological response was documented and the catheter was removed. DISCUSSION: Systemic and intracatheter therapy with DPT is feasible, carries no toxicity and is apparently effective. DPT might be a suitable therapeutic option in CRBSI to achieve CVC sterilization and preserve the catheter.

Technical note: Evaluation of a real-time wireless pH measurement system relative to intraruminal differences of digesta in dairy cattle.

The aim of this study was to evaluate the accuracy and precision of indwelled wireless sensors relative to intrareticuloruminal differences in dairy cows transitioned from a forage to a high-concentrate diet. A feeding trial was performed with 8 rumen-cannulated Holstein cows. The cows were stepwise switched from 0 to 60% concentrate in the diet and fed 5 wk. Samples from the free ruminal liquid (FRL) from the ventral rumen and from the particle-associated ruminal liquid (PARL) in the rumen mat were manually taken at 0, 4, and 8 h after the morning feeding on d 0, 7, 14, and 34 of the experiment through the ruminal cannula to measure pH in FRL and PARL using a pH electrode. Additionally indwelling reticular wireless pH sensors were used to measure reticular pH every 10 min throughout the experiment. Precision and accuracy properties as a measure of reproducibility of the methods were statistically evaluated. Data showed significant differences among pH readings of indwelling sensors and pH measurements taken by means of a conventional electrode in both FRL and PARL (P<0.05). These differences became more evident when 60% concentrate diet was fed. Across all experimental days, the pH of the FRL was greatest and the pH reported by indwelling sensors intermediate, whereas the pH of PARL was lowest. The concordance correlation coefficient (CCC) analysis revealed a high agreement between indwelling sensors and FRL (CCC=0.709) but a low agreement with the pH of PARL (CCC=0.495). In conclusion, the study indicated that wireless sensors can satisfactorily reflect the pH of FRL but poorly reflect that of PARL.

Multidrug-resistant Pseudomonas aeruginosa bloodstream infections: risk factors and mortality.

We retrospectively studied patients diagnosed with P. aeruginosa bloodstream infections (BSIs) in two Italian university hospitals. Risk factors for the isolation of multidrug-resistant (MDR) or non-MDR P. aeruginosa in blood cultures were identified by a case-case-control study, and a cohort study evaluated the clinical outcomes of such infections. We identified 106 patients with P. aeruginosa BSI over the 2-year study period; 40 cases with MDR P. aeruginosa and 66 cases with non-MDR P. aeruginosa were compared to 212 controls. Independent risk factors for the isolation of MDR P. aeruginosa were: presence of central venous catheter (CVC), previous antibiotic therapy, and corticosteroid therapy. Independent risk factors for non-MDR P. aeruginosa were: previous BSI, neutrophil count <500/mm3, urinary catheterization, and presence of CVC. The 21-day mortality rate of all patients was 33·9%. The variables independently associated with 21-day mortality were presentation with septic shock, infection due to MDR P. aeruginosa, and inadequate initial antimicrobial therapy.

Risk factors for severe complications of the novel influenza A (H1N1): analysis of patients hospitalized in Italy.

Eighty-one patients affected by the novel influenza A (H1N1), hospitalized in North-western Italy, were studied. The median age was 32 years (range 1-81 years). Fifty-six (69%) had an underlying medical condition, including lung disorders (asthma or chronic obstructive pulmonary disease) in 34% and obesity in 25%. Fifty percent of them had pneumonia, 12% were admitted to the intensive care unit and 3% died. Antiviral treatment was initiated in 75% of patients started within 48 h. Older age and lung and neurocognitive disorders were associated with severe disease and death.

The role of dietary selenium in bovine mammary gland health and immune function.

Mastitis is not only a major cause of economic losses to the dairy industry but also a major problem in ensuring the quality and safety of the milk, associated with high somatic cell counts and residues of antibiotics used for treatment. One innovative approach to protection against mastitis is to stimulate the animal's natural defense mechanisms. Technological advances in immunological research have increased our ability to exploit the immunity of the bovine mammary gland during periods of high susceptibility to disease. The trace element selenium affects the innate and the adaptive immune responses of the mammary gland through cellular and humoral activities. Substantial research has been carried out on the effect of selenium (Se) on the immune function of the mammary gland and subsequent improvement in bovine udder health and mastitis control. Levels higher than current recommendations and Se-yeast can potentially be used to enhance our capacity to modulate the physiological mechanisms of the bovine mammary gland to respond to infection. This article provides an overview of the most recent research in this field.

Effect of oregano (O. majorana x O. vulgare) on performance and antioxidative capacity of quails fed a diet rich in omega3 fatty acids.

Oregano possesses high antioxidant activity and could therefore be used to enhance oxidative stability of eggs high in omega3 fatty acids. In this study, 20 female quails were fed a diet containing 4% linseed oil. They were divided into two groups, one receiving oregano, and the other grass meal as control (2% respectively). Cholesterol oxidation products were analysed in fresh eggs, in stored eggs and in the livers. Trolox equivalent antioxidative capacity of plasma was measured. No significant differences were seen between the groups.

TEM characterisation of porous silicon

In this work, the results of a structural investigation by transmission electron microscopy of porous silicon and porous silicon-based devices is reported. This investigation covers a wide range of porous silicon materials going from photoluminescent micro- or meso-porous silicon to macro-porous layers as well as some recent applications of this material for the fabrication of porous silicon and Si/SiO2 superlattices, suspended thick membranes and gas sensor devices. It appears that the structural investigation technique here employed, is a fundamental tool for the optimisation of the technological processing of this material. From the results reported in this work, a quite comprehensive view of the potentialities and limitations of the applications of porous silicon in the field of optical and gas sensor devices should also emerge. Finally, some solutions to the problems usually met during the technological processing of this material are proposed.