Effects of feeding pasteurized waste milk to dairy calves on phenotypes and genotypes of antimicrobial resistance in fecal Escherichia coli isolates before and after weaning

The aim of this study was to evaluate the effects of feeding pasteurized waste milk (pWM) to calves on antimicrobial resistance of fecal Escherichia coli at both phenotypic and genotypic levels. Fifty-two Holstein female calves (3 ± 1.3 d of age) were fed 1 of the 2 different types of milk: milk replacer (MR) without antimicrobials or pWM with β-lactam residues until weaning at 49 d of age. Fecal swabs of all calves were obtained on d 0, 35, and 56 of the study and 3 E. coli isolates per sample were studied. Phenotypic resistance was tested by the disk diffusion method against a panel of 12 antimicrobials. A total of 13 resistance genes consisting of β-lactam, sulfonamide, tetracycline, and aminoglycoside families were examined by PCR. Feeding pWM to calves increased the presence of phenotypic resistance to ampicillin, cephalotin, ceftiofur, and florfenicol in fecal E. coli compared with MR-fed calves. However, the presence of resistance to sulfonamides, tetracyclines, and aminoglycosides was common in dairy calves independent of their milk-feeding source, suggesting other factors apart from the feeding source are involved in the emergence of antimicrobial resistance.

Inequities in postnatal care in low- and middle-income countries: a systematic review and meta-analysis

Objective

To assess the socioeconomic, geographical and demographic inequities in the use of postnatal health-care services in low- and middle-income countries.

Methods

We searched Medline, Embase and Cochrane Central databases and grey literature for experimental, quasi-experimental and observational studies that had been conducted in low- and middle-income countries. We summarized the relevant studies qualitatively and performed meta-analyses of the use of postnatal care services according to selected indicators of socioeconomic status and residence in an urban or rural setting.

Findings

A total of 36 studies were included in the narrative synthesis and 10 of them were used for the meta-analyses. Compared with women in the lowest quintile of socioeconomic status, the pooled odds ratios for use of postnatal care by women in the second, third, fourth and fifth quintiles were: 1.14 (95% confidence interval, CI : 0.96–1.34), 1.32 (95% CI: 1.12–1.55), 1.60 (95% CI: 1.30–1.98) and 2.27 (95% CI: 1.75–2.93) respectively. Compared to women living in rural settings, the pooled odds ratio for the use of postnatal care by women living in urban settings was 1.36 (95% CI: 1.01–1.81). A qualitative assessment of the relevant published data also indicated that use of postnatal care services increased with increasing level of education.

Conclusion

In low- and middle-income countries, use of postnatal care services remains highly inequitable and varies markedly with socioeconomic status and between urban and rural residents.

Effects of cinnamaldehyde or monensin on performance of weaned Holstein dairy heifers

The objective of this 70-d study was to determine the effects of the essential oil cinnamaldehyde compared with the ionophore monensin on performance of weaned Holstein dairy heifers. Eighty-four Holstein dairy heifers (91 ± 3.33 d of age; 109 ± 7.55 kg) were housed in a naturally ventilated curtain sidewall, straw-bedded barn in 12 pens with 7 heifers/pen (3.98 m²/head). Heifers were randomly assigned to 1 of 4 treatments in a completely randomized design: (1) control (CON; carrier, 908 g of ground corn), (2) monensin sodium [MON; 1 mg/kg of body weight (BW) + carrier], (3) cinnamaldehyde (CIN1; 1 mg/kg of BW + carrier), or (4) cinnamaldehyde (CIN2; 2 mg/kg of BW + carrier). The treatments were hand-mixed into a 20% crude protein (CP) whole shelled corn and protein pellet mix fed at 2.21 kg/heifer daily. Heifers had access to free-choice hay and water daily. Initial BW and hip heights were taken at the start of the study and every other week thereafter until calves reached 23 wk of age. Blood samples were also taken on each weigh day to determine plasma urea nitrogen, glucose, and insulin-like growth factor-1 concentrations. Fecal samples were taken from the same 3 heifers/pen initially and then at d 28, 56, and 70 of the study for coccidia counts. Cinnamaldehyde had no performance effects on growth, hay intake, hip height, or blood metabolites compared with MON or CON. Average daily gains were 0.98, 0.99, 1.01, and 1.03 kg/d, and average hay intakes per pen were 17.08, 16.34, 18.11, and 17.60 kg/d for CON, MON, CIN1, and CIN2, respectively. Fecal samples by pens indicated the presence of viable coccidia, but the counts were low and not consistent across heifers within each pen. No benefits were associated with supplementing cinnamaldehyde or monensin into grain mixes for weaned heifers.

Molecular transport through large-diameter DNA nanopores

DNA-based nanopores are synthetic biomolecular membrane pores, whose geometry and chemical functionality can be tuned using the tools of DNA nanotechnology, making them promising molecular devices for applications in single-molecule biosensing and synthetic biology. Here we introduce a large DNA membrane channel with an ≈4 nm diameter pore, which has stable electrical properties and spontaneously inserts into flat lipid bilayer membranes. Membrane incorporation is facilitated by a large number of hydrophobic functionalizations or, alternatively, streptavidin linkages between biotinylated channels and lipids. The channel displays an Ohmic conductance of ≈3 nS, consistent with its size, and allows electrically driven translocation of single-stranded and double-stranded DNA analytes. Using confocal microscopy and a dye influx assay, we demonstrate the spontaneous formation of membrane pores in giant unilamellar vesicles. Pores can be created both in an outside-in and an inside-out configuration.

Artificial DNA membrane channels are promising molecular devices for biotechnology but suffer from low affinity for lipid bilayers. Here, the authors report a large DNA nanopore that spontaneously inserts into a flat lipid membrane, driven by engineered hydrophobic or streptavidin-biotin interactions.

Economics of Musculoskeletal Ultrasound

Purpose of review

Healthcare costs have exploded in the past 30 years and they are a major concern for governments worldwide. Care management of musculoskeletal disorders and advanced imaging account for a large part of this socioeconomic burden.

Recent findings

Musculoskeletal ultrasound is now performed primarily by nonradiologists. Both musculoskeletal ultrasound and MRI total utilization rates continue to increase. Despite the existence of evidence-based diagnostic recommendations and the potential cost-savings of using musculoskeletal ultrasound instead of MRI in certain clinical situations, ensuring appropriate use of imaging among health professionals remains difficult for various reasons.

Summary

In the context of healthcare budgets restraints, use of imaging must be shown scientifically, to improve patient outcomes and be cost-effective. Current evidence recommends musculoskeletal ultrasound as the primary imaging modality in the investigation of rotator cuff disease. Policies aiming at ensuring the application of imaging guidelines among physicians are needed.

Responses to ARUBA: a systematic review and critical analysis for the design of future arteriovenous malformation trials

OBJECTIVE The ARUBA study (A Randomized Trial of Unruptured Brain Arteriovenous Malformations [AVMs]) on unruptured brain AVMs has been the object of comments and editorials. In the present study the authors aim to systematically review critiques, discuss design issues, and propose a framework for future trials. METHODS The authors performed a systematic review of the French and English literature on the ARUBA study published between January 2006 and February 2015. The electronic search, including the Cochrane Library, MEDLINE (PubMed and Ovid), CINAHL, and EMBASE databases, was complemented by hand searching and cross-referencing. The comments were categorized as items related to the design, the conduct, and the analysis and interpretation of the trial. RESULTS Thirty-one articles or letters were identified. The pragmatic design, with heterogeneity of patients and lack of standardization of the treatment arm, were frequently stated concerns. The choice of outcome measures was repeatedly criticized. During the trial, low enrollment rates, selection bias, and premature interruption of enrollment were frequent comments. The short follow-up period, the lack of subgroup analyses, the lack of details on the results of the various treatments, and a contentious interpretation of results were noted at the analysis stage. A fundamental problem was the primary hypothesis testing conservative management. The authors believe that other trials are needed. Future trials could be pragmatic, test interventions stratified at the time of randomization, and look for long-term, hard clinical outcomes in a large number of patients. CONCLUSIONS In the authors' view, the ARUBA trial is a turning point in the history of brain AVM management; future trials should aim at integrating trial methodology and clinical care in the presence of uncertainty.