The effects of antibiotic-free supplementation on the ruminal pH variability and methane emissions of beef cattle under the challenge of subacute ruminal acidosis (SARA).

Subacute ruminal acidosis (SARA) in feedlot cattle during the feed transition to grain-based diets is a significant constraint to animal health and productivity. This experiment assessed an antibiotic-free supplement (ProTect®) effects on ruminal pH variability and methane (CH4) emissions of cattle during the challenge of SARA. Ten 18-month-old Angus steers (472 ± 4.8 kg) were randomly allocated into monensin (n = 5) and ProTect® groups (n = 5) and progressively introduced to grain diets incorporating monensin or ProTect® for 36 days of the experiment [starter (7 days; 45% grain), T1 (7 days; 56% grain), T2 (7 days; 67% grain), finisher (15 days; 78% grain)]. The pH variability on the finisher period was reduced by the ProTect® supplement (6.6% vs. 5.2%; P < 0.01), with CH4 emissions being significantly higher relative to the monensin group [88.2 g/day (9.3 g CH4/kg DMI) vs. 133.7 g/day (14.1 g CH4/kg DMI); P < 0.01]. There was no difference between treatments in the time spent on the ruminal pH < 5.6 or < 5.8 (P > 0.05). The model evaluation for the ruminal pH variation indicated that the mean absolute error (MAE) proportion for both groups was good within the same range [4.05% (monensin) vs. 4.25% (ProTect®)] with identical root mean square prediction error (RMSPE) (0.34). It is concluded that the ProTect® supplement is an effective alternative to monensin for preventing SARA in feedlot cattle by managing ruminal pH variation during the transition to high-grain diets. Both monensin and ProTect® supplemented cattle exhibited lower CH4 yield compared to cattle fed forages and low-concentrate diets.

Conversion of oral alfacalcidol to oral calcitriol in the treatment of secondary hyperparathyroidism in chronic hemodialysis patients.

PURPOSE: The optimal vitamin D3 therapy for the treatment of secondary hyperparathyroidism (SHPT) in chronic hemodialysis patients is still controversial. Recent studies suggest that uremia in end-stage renal disease is associated with enzymatic hepatic dysfunction altering 25-hydroxylation of vitamin D3. The goal of our study was to compare the efficacy of calcitriol, the fully hydroxylated active form of vitamin D3, to alfacalcidol which needs 25-hydroxylation to be effective, for the treatment of SHPT in chronic hemodialysis patients. METHODS: We retrospectively reviewed 45 chronic hemodialysis patients who were switched from oral alfacalcidol to oral calcitriol for the treatment of SHPT. Parathyroid hormone (PTH), serum calcium and serum phosphorus levels were compared pre- and post-conversion using paired Student's t tests. RESULTS: The mean dose of active vitamin D3 decreased from 3.50 mcg/week at baseline to 2.86 mcg (P < 0001) after the switch from alfacalcidol to calcitriol. PTH significantly decreased from 94.4 to 82.6 pmol/L (-11.8 pmol/L, P = 0.02). The mean corrected calcium increased from 2.17 to 2.25 mmol/L (+0.08 mmol/L, P < 0.001) without any clinically significant hypercalcemia, and phosphorus levels were stable. Results were similar in a subgroup of patients (n = 17) for whom the medication was administrated during the hemodialysis session, ensuring a complete compliance. CONCLUSIONS: According to our study, calcitriol in equal dosage is more effective than alfacalcidol in lowering serum PTH level in chronic hemodialysis patients. This suggests that calcitriol may be the optimal active vitamin D3 for the treatment of SHPT in chronic hemodialysis patients.

Designing smart particles for the assembly of complex macroscopic structures.

Particle get-together: Surface functionalization with a branched copolymer surfactant is used to create responsive inorganic particles that can self-assemble in complex structures. The assembly process is triggered by a pH switch that reversibly activates multiple hydrogen bonds between ceramic particles (see picture; yellow) and soft templates (n-decane; green).

Ciprofloxacin resistance in the faecal carriage of patients undergoing transrectal ultrasound guided prostate biopsy.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Transrectal ultrasound guided prostate biopsies (TRUSBx) are associated with a spectrum of complications, including most significantly infection, which affects up to 5% of patients. In the most severe cases, infection leads to sepsis, a life-threatening complication. Escherichia coli is the primary responsible pathogen. Although antibiotic prophylaxis with fluoroquinolones is routinely used, there is evidence that the infection rate after TRUSBx is increasing, and this appears to be due to an increasing prevalence of ciprofloxacin-resistant rectal flora. This is the largest prospective clinical trial to date analysing the rectal flora of men undergoing prostate biopsies. We determined the microbial and antibiotic sensitivity profiles from 849 patients. Ciprofloxacin-resistant Gram-negative organisms were identified in the rectal flora of 19.0% of men. Furthermore, fluoroquinolone use within 6 months preceding a TRUSBx and the presence of a prosthetic heart valve were significant predictors of ciprofloxacin resistance on rectal swab. Determining the prevalence of rectal fluoroquinolone resistance has important implications in evaluation of the suitability of prophylactic regimens. Antimicrobial profiles derived from rectal swabs pre-biopsy may prove useful in guiding targeted antibiotic prophylaxis. OBJECTIVES: To establish the prevalence of ciprofloxacin-resistant bacteria in patients undergoing transrectal ultrasound guided prostate biopsies (TRUSBx) and to determine whether this predicts subsequent infectious complications. To identify risk factors for harbouring ciprofloxacin-resistant flora. PATIENTS AND METHODS: Any patient undergoing a TRUSBx from 2009 to 2011 was eligible for enrolment in this prospective study. Pre-biopsy rectal and urine cultures and post-biopsy urine cultures were obtained and antimicrobial susceptibility was determined. Univariate and multivariate analyses were performed to identify independent patient risk factors associated with ciprofloxacin-resistant rectal flora. RESULTS: A total of 865 patients underwent TRUSBx, of whom 19.0% were found to have ciprofloxacin-resistant Gram-negative coliforms. Escherichia coli was the most prevalent Gram-negative rectal isolate (80.9%) and accounted for 90.6% of ciprofloxacin resistance. Patient characteristics that conferred an increased risk of harbouring ciprofloxacin-resistant organisms included a history of a heart valve replacement (P < 0.05) and ciprofloxacin use in the past 3 months (P < 0.05). Infectious complications were observed in 3.6% (n = 31) of the patient population and 48% of these patients grew ciprofloxacin-resistant organisms on the pre-biopsy rectal swab (P < 0.001). CONCLUSIONS: Antimicrobial resistance to ciprofloxacin in the rectal flora was common, particularly in patients with recent ciprofloxacin use and a heart valve replacement. Despite a significant correlation between those patients who developed infections and the detection of ciprofloxacin-resistant organisms, only 9.0% (n = 15) of the total group with ciprofloxacin resistance developed an infectious complication. Future studies will need to evaluate the cost effectiveness and clinical utility of a pre-biopsy rectal culture in targeting antibiotic prophylaxis.

YY1 regulates melanocyte development and function by cooperating with MITF.

Studies of coat color mutants have greatly contributed to the discovery of genes that regulate melanocyte development and function. Here, we generated Yy1 conditional knockout mice in the melanocyte-lineage and observed profound melanocyte deficiency and premature gray hair, similar to the loss of melanocytes in human piebaldism and Waardenburg syndrome. Although YY1 is a ubiquitous transcription factor, YY1 interacts with M-MITF, the Waardenburg Syndrome IIA gene and a master transcriptional regulator of melanocytes. YY1 cooperates with M-MITF in regulating the expression of piebaldism gene KIT and multiple additional pigmentation genes. Moreover, ChIP-seq identified genome-wide YY1 targets in the melanocyte lineage. These studies mechanistically link genes implicated in human conditions of melanocyte deficiency and reveal how a ubiquitous factor (YY1) gains lineage-specific functions by co-regulating gene expression with a lineage-restricted factor (M-MITF)-a general mechanism which may confer tissue-specific gene expression in multiple lineages.

A multimodal RAGE-specific inhibitor reduces amyloid ß-mediated brain disorder in a mouse model of Alzheimer disease.

In Alzheimer disease (AD), amyloid ß peptide (Aß) accumulates in plaques in the brain. Receptor for advanced glycation end products (RAGE) mediates Aß-induced perturbations in cerebral vessels, neurons, and microglia in AD. Here, we identified a high-affinity RAGE-specific inhibitor (FPS-ZM1) that blocked Aß binding to the V domain of RAGE and inhibited Aß40- and Aß42-induced cellular stress in RAGE-expressing cells in vitro and in the mouse brain in vivo. FPS-ZM1 was nontoxic to mice and readily crossed the blood-brain barrier (BBB). In aged APPsw/0 mice overexpressing human Aß-precursor protein, a transgenic mouse model of AD with established Aß pathology, FPS-ZM1 inhibited RAGE-mediated influx of circulating Aß40 and Aß42 into the brain. In brain, FPS-ZM1 bound exclusively to RAGE, which inhibited ß-secretase activity and Aß production and suppressed microglia activation and the neuroinflammatory response. Blockade of RAGE actions at the BBB and in the brain reduced Aß40 and Aß42 levels in brain markedly and normalized cognitive performance and cerebral blood flow responses in aged APPsw/0 mice. Our data suggest that FPS-ZM1 is a potent multimodal RAGE blocker that effectively controls progression of Aß-mediated brain disorder and that it may have the potential to be a disease-modifying agent for AD.

Accuracy of parental report and electronic health record documentation as measures of diet and physical activity counseling.

OBJECTIVE: To determine whether parental reports and electronic health record documentation of physician counseling on nutrition and physical activity reflect actual counseling provided. METHODS: Participants were parents of 198 children 2 to 12 years of age seen in a primary care pediatric clinic at an academic medical center for well child care and their 38 physicians. Parents completed a post-visit questionnaire to report discussions on weight, nutrition, and physical activity that occurred during the visit. Electronic health records were reviewed to measure documentation of these topics during the visit. Parental reports and records were compared with actual discussions on the basis of coded audiotapes. Counseling was coded as having occurred if specific topics were mentioned during the encounter, however brief this mention was. RESULTS: A total of 48% of the children were female, they were a mean age of 5.4 years, and 28% were overweight or obese. Sensitivity of parental report was high (63%-96%), but specificity was low (43%-77%) because of parents' tendency to overreport counseling. Sensitivity of electronic health record documentation was generally low (40%-53%) except for discussion of screen time (92%) and physical activity (88%); the specificity of these data was also poor (42% and 21%, respectively, for screen time and physical activity). CONCLUSIONS: Electronic health record documentation may not be the most valid method of measuring physician counseling on weight, nutrition, and physical activity in pediatric primary care. Parental report via the use of a questionnaire administered immediately after the visit is a better alternative in quality improvement or research studies when resources do not allow for direct observation, with the caveat that parents may overreport whether counseling was provided.

Translational biomarkers: from preclinical to clinical a report of 2009 AAPS/ACCP Biomarker Workshop.

There have been some successes in qualifying biomarkers and applying them to drug development and clinical treatment of various diseases. A recent success is illustrated by a collaborative effort among the US Food and Drug Administration, the European Medicines Agency, and the pharmaceutical industry to provide a set of seven preclinical kidney toxicity biomarkers for drug development. Other successes include, but are not limited to, clinical biomarkers for cancer treatment and clinical management of heart transplant patients. The value of fully qualified surrogate endpoints in facilitating successful drug development is undisputed, especially for diseases in which the traditional clinical outcome can only be assessed in large, multi-year trials. Emerging biomarkers, including chemical genomic or imaging biomarkers, and measurement of circulating tumor cells hold great promise for early diagnosis of disease and as prognostic tests for managing treatment of chronic diseases such as osteoarthritis, Alzheimer disease, cardiovascular disease, and cancer. To advance the success of treating and managing these diseases, efforts are needed to establish the temporal relationship between changes in inflammatory or imaging biomarkers with the progression of the chronic disease, and in the case of cancer, between the extent of circulating cancer cells and tumor progression or remission.

Metabolic and nutritional changes after bariatric surgery.

Bariatric surgery is the most durable intervention for severe obesity. Appropriate candidates for surgery include those with a body mass index over 40 kg/m(2), or those with a BMI over 35 kg/m(2) who also have weight-related comorbidities. Bariatric procedures are categorized as restrictive, where food intake is limited by a small gastric 'pouch'; malabsorptive, where the length of intestine available for nutrient absorption is decreased; or a combination of both. Although pure malabsorptive procedures, such as the now-historical jejunoileal bypass, achieve greater weight loss than restrictive procedures, they are generally associated with more postoperative metabolic problems. The Roux-en-Y gastric bypass is currently considered the gold standard bariatric procedure for most patients. It results in excellent weight loss with minimal complications, but does require life-long vitamin supplementation. Compliance with vitamins and supplements is also mandatory after malabsorptive procedures. With these procedures, decreased oral intake, as well as altered absorption of nutrients from the GI tract, results in potentially low blood levels of a variety of micronutrients, especially iron, vitamin B12 and folate. Bariatric surgery also improves the comorbid conditions that are associated with obesity, such as diabetes, hypertension, dyslipidemia, obstructive sleep apnea, obesity hypoventilation, gastroesophageal reflux disease, asthma, venous stasis, polycystic ovary syndrome and pseudotumor cerebri. The resolution of diabetes is secondary to weight loss and may also be due to alteration of the enteroinsular axis.

Normal levels of prepulse inhibition in the euthymic phase of bipolar disorder.

BACKGROUND: Deficits in prepulse inhibition (PPI) of the acoustic startle response have been suggested as a potentially useful endophenotype for schizophrenia spectrum disorders and may explain certain symptoms and cognitive deficits observed in the psychoses. PPI deficits have also been found in mania, but it remains to be confirmed whether this dysfunction is present in the euthymic phase of bipolar disorder. METHOD: Twenty-three adult patients with DSM-IV bipolar disorder were compared to 20 controls on tests of acoustic startle reactivity and PPI of the startle response. Sociodemographic and treatment variables were recorded and symptom scores assessed using the Hamilton Depression Inventory and the Young Mania Rating Scale. RESULTS: Overall, the patient and control groups demonstrated similar levels of startle reactivity and PPI, although there was a trend for the inter-stimulus interval to differentially affect levels of PPI in the two groups. CONCLUSIONS: In contrast to bipolar patients experiencing a manic episode, general levels of PPI were normal in this euthymic sample. Further studies are required to confirm this finding and to determine the mechanisms by which this potential disruption/normalization occurs. It is suggested that an examination of PPI in a high-risk group is required to fully discount dysfunctional PPI as a potentially useful endophenotype for bipolar disorder.