A randomized controlled trial investigating the effect of transport duration and age at transport on surplus dairy calves: Part II. Impact on hematological variables.

Surplus dairy calves often arrive at veal and dairy-beef rearing facilities with health and blood metabolite level abnormalities, which can affect their welfare and performance, predisposing them to future health challenges. The objective of this randomized controlled trial was to investigate the effects of transport duration and age at the time of transport on blood parameters in surplus dairy calves following 6, 12, or 16 h of continuous road transportation. All surplus calves from 5 commercial dairy farms in Ontario were enrolled and examined daily before transport (n = 175). On the day of transportation, calves were weighed, blood sampled, and randomly assigned to 6, 12, or 16 h of transportation. Blood samples were then collected immediately after transportation, as well as 24, 48, and 72 h thereafter. Serum was analyzed at a provincial diagnostic laboratory for nonesterified fatty acids (NEFA), ß-hydroxybutyric acid (BHBA), creatine kinase (CK), cholesterol, and haptoglobin. In addition, blood gas and electrolyte values were also assessed at the time of sample collection. Mixed models with repeated measures were used to assess the effects of transport duration, breed, sex, transfer of passive immunity status, weight before transportation, and age at transportation on blood parameters. Immediately following transportation, NEFA and BHBA were greater for calves transported for 12 h (Δ = 0.22 mmol/L NEFA, 95% CI = 0.15 to 0.30; Δ = 0.04 mmol/L BHBA, 95% CI = 0.02 to 0.06) and 16 h (Δ = 0.35 mmol/L NEFA, 95% CI = 0.27 to 0.42; Δ = 0.10 mmol/L BHBA, 95% CI = 0.08 to 0.11) compared with calves transported for 6 h. Glucose was lower immediately following transportation in calves transported for 16 h compared with 6 h (Δ = -15.54 mg/dL, 95% CI = -21.54 to -9.54). In addition, pH and HCO3- were lower in calves transported for 12 (Δ = -0.09 pH, 95% CI = -0.13 to -0.05; Δ = -1.59 mmol/L HCO3-, 95% CI = -2.61 to -0.56) and 16 h (Δ = -0.07 pH, 95% CI = -0.12 to -0.03; Δ = -1.95 mmol/L HCO3-, 95% CI = -2.95 to -0.95) compared with calves transported for 6 h. Calves transported between 15 and 19 d of age had a higher concentration of cholesterol and CK (Δ = 0.27 mmol/L cholesterol; 37.18 U/L CK) compared with 2- to 6-d-old calves, and calves 12 to 14 d old had greater reduction in HCO3- (Δ = -0.92 mmol/L) compared with 2- to 6-d-old calves. These findings show that transporting calves for long distances results in lower glucose concentration and suboptimal energy status, and that this effect varies based on the calf's age.

Metasurfaces with Asymmetric Optical Transfer Functions for Optical Signal Processing.

Metasurface thin films created from arrays of structured optical elements have been shown to perform spatial filtering of optical signals. To extend their usefulness it is important that the symmetry of their response with changes to the in-plane wave vector k_{p}→-k_{p} can be tailored or even dynamically tuned. In this Letter we use a general theory of metasurfaces constructed from nondiffracting arrays of coupled metal particles to derive the optical transfer function and identify the physical properties essential for asymmetry. We validate our theory experimentally showing how the asymmetric response of a two-dimensional (planar) metasurface can be optically tuned. Our results set the direction for future developments of metasurfaces for optical signal processing.

Evaluation of the systemic innate immune response and metabolic alterations of nonlactating cows with diet-induced subacute ruminal acidosis.

Subacute ruminal acidosis (SARA) increases lipopolysaccharide endotoxin in the rumen, which might translocate into the systemic circulation, triggering a cascade of clinical and immunological alterations. The objective of this study was to characterize the clinical immune and metabolic responses to ruminal-derived lipopolysaccharide in nonlactating cows induced with SARA using 2 challenges, a grain-based SARA challenge (GBSC) or an alfalfa-pellet SARA challenge (APSC). Six dry, nonlactating Holstein cows were used in a 3 × 3 Latin square arrangement of treatments with 4-wk experimental cycles. All cows received the control diet containing 70% forage and 30% mixed concentrates (dry matter basis) for 3 wk. In wk 4, cows received a control diet, GBSC (38% wheat-barley pellets, 32% other mixed concentrate, and 30% forages), or APSC (45% mixed concentrate, 32% alfalfa pellets, and 23% other forages). Total plasma proteins and immunology-related proteins, acute phase proteins, blood cells, serum chemistry, mRNA gene expression of peripheral blood cell surface markers, and selected proinflammatory cytokines were evaluated. Ruminal pH was lower in both groups with induced SARA compared with a control group. Ruminal endotoxins were higher in GBSC; however, plasma endotoxin was not detected in any study group. No significant differences in feed intake, rectal temperature, white blood cell counts, or differentials were found between control and SARA challenge groups; changes in glucose, urea, Ca, and Mg were observed in SARA groups. Total plasma proteins were lower in both SARA groups, and acute phase proteins were higher in GBSC. The expression of CD14, MD2, and TLR4 mRNA in peripheral blood leukocytes was not affected by SARA induction. The induction of SARA as a result of GBSC or APSC challenge was successful; however, LPS was not detected in plasma. Changes in clinical, metabolic, and inflammatory responses were not observed in the SARA-challenged cows, suggesting that, in this study, SARA was not associated with a systemic response to inflammation.

The dark side of plasmonics.

Plasmonic dark modes are pure near-field modes that can arise from the plasmon hybridization in a set of interacting nanoparticles. When compared to bright modes, dark modes have longer lifetimes due to their lack of a net dipole moment, making them attractive for a number of applications. We demonstrate the excitation and optical detection of a collective dark plasmonic mode from individual plasmonic trimers. The trimers consist of triangular arrangements of gold nanorods, and due to this symmetry, the lowest-energy dark plasmonic mode can interact with radially polarized light. The experimental data presented confirm the excitation of this mode, and its assignment is supported with an electrostatic approximation wherein these dark modes are described in terms of plasmon hybridization. The strong confinement of energy in these modes and their associated near fields hold great promise for achieving strong coupling to single photon emitters.

Frequency-dependent optical steering from subwavelength plasmonic structures.

We show theoretically and with numerical simulations that the direction of the in-plane scattering from a subwavelength optical antenna system can be controlled by the frequency of the incident light. This optical steering effect does not rely on propagation phase shifts or diffraction but arises from phase shifts in the localized surface plasmon modes of the antenna. An analytical model is developed to optimize the parameters for the configuration, showing good agreement with a rigorous numerical simulation. The simulation predicts a 25° angular shift in the direction of the light scattered from two gold nanorods for a wavelength change of 12 nm.

Tissue factor as a novel marker for detection of circulating cancer cells.

Tissue factor (TF) is a molecular marker that is up-regulated in cancer cells and aids tumoral dissemination. Our purpose was to develop a nested RT-PCR strategy against TF for detecting blood-borne tumour cells. Our method detected TF expression in a minimum of 1.5 pg total RNA from MCF7 cells. A preliminary study in blood samples from 16 advanced breast carcinoma patients showed that 80% of patients with high TF load progressed and died, while only 18% with low TF load showed the same behaviour. Kaplan-Meier analysis confirmed worse overall survival in patients with high TF load.

Simple model for the hybridization of surface plasmon resonances in metallic nanoparticles.

An "electrostatic" eigenmode method based on the coupling of evanescent electric fields is presented for modeling the hybridization of localized surface plasmon resonances in metallic nanoparticles of arbitrary shape. The method yields simple analytical expressions for the hybridized energies and excitation amplitudes of nanoparticle ensembles. Because of its ease of applicability and simple conceptual basis, we anticipate that the method will be of value in understanding and predicting the effects of interacting plasmonic nanoparticles.

Surface plasmon mediated strong exciton-photon coupling in semiconductor nanocrystals.

We present an experimental demonstration of strong coupling between a surface plasmon propagating on a planar silver thin film and the lowest excited state of CdSe nanocrystals. Attenuated total reflection measurements demonstrate the formation of plasmon-exciton mixed states, characterized by a Rabi splitting of approximately 112 meV at room temperature. Such a coherent interaction has the potential for the development of nonlinear plasmonic devices, and furthermore, this system is akin to those studied in cavity quantum electrodynamics, thus offering the possibility to study the regime of strong light-matter coupling in semiconductor nanocrystals under easily accessible experimental conditions.

A multidisciplinary approach to reduce and refine antimicrobial drugs use for diarrhoea in dairy calves.

This study evaluated the impact of a multidisciplinary intervention to reduce and refine antimicrobial drug use for treatment of diarrhoea in dairy calves. The intervention consisted of modification of management practices for disease prevention, health evaluation training of farm staff, implementation of an algorithm directed at antimicrobial therapy for diarrhoeic calves, and monthly farm visits. A combination of retrospective (before intervention period [BP], 1 year) and prospective (immediately after intervention period [AP], 1 year) cohorts were used. Health outcomes measured included incidence of diarrhoea and overall mortality. Antimicrobial treatment rates for diarrhoea and total mass of antimicrobial drugs used at the calf and farm level were also evaluated. Outcomes were assessed using the χ2 or Fisher's exact test, and odds ratios and 95% confidence intervals (95% CI) were calculated. Records of 2049 and 2251 calves from 10 farms were available in the BP and AP, respectively. Reduced antimicrobial treatment rates occurred on seven farms (P < 0.01), but not on three farms in the AP. A total of 85% (1303/1573) and 18% (310/1698) of diarrhoeic calves were treated with antimicrobial drugs in the BP and AP (P < 0.001), respectively. There were no differences in the incidence of diarrhoea or mortality between periods. In the AP, the use sulfamethazine and trimethoprim decreased on eight farms, one farm discontinued use of lincomycin and spectinomycin, while two farms discontinued use and one reduced use of cephalosporins. This multidisciplinary approach was effective in reducing antimicrobial drug use for calf diarrhoea on dairy farms without negative impacts on calf health.

Relevance of small GTPase Rac1 pathway in drug and radio-resistance mechanisms: Opportunities in cancer therapeutics.

Rac1 GTPase signaling pathway has a critical role in the regulation of a plethora of cellular functions governing cancer cell behavior. Recently, it has been shown a critical role of Rac1 in the emergence of resistance mechanisms to cancer therapy. This review describes the current knowledge regarding Rac1 pathway deregulation and its association with chemoresistance, radioresistance, resistance to targeted therapies and immune evasion. This supports the idea that interfering Rac1 signaling pathway could be an interesting approach to tackle cancer resistance.

Detection of Bovine Coronavirus in Healthy and Diarrheic Dairy Calves.

BACKGROUND: BCoV is identified in both healthy and diarrheic calves, complicating its assessment as a primary pathogen. OBJECTIVES: To investigate the detection rates of bovine coronavirus (BCoV) in feces of healthy and diarrheic calves and to describe the usefulness of a pancoronavirus reverse transcriptase (RT) PCR (PanCoV-RT-PCR) assay to identify BCoV in samples of diarrheic calves. ANIMALS: Two hundred and eighty-six calves <21 days. Calves with liquid or semiliquid feces, temperature >39.5°C, and inappetence were considered as cases, and those that had pasty or firm feces and normal physical examination were designated as controls. METHODS: Prospective case-control study. A specific BCoV-RT-PCR assay was used to detect BCoV in fecal samples. Association between BCoV and health status was evaluated by exact and random effect logistic regression. Fecal (n = 28) and nasal (n = 8) samples from diarrheic calves were tested for the presence of BCoV by both the PanCoV-RT-PCR and a specific BCoV-RT-PCR assays. A Kappa coefficient test was used to assess the level of agreement of both assays. RESULTS: BCoV was detected in 55% (157/286) of calves; 46% (66/143), and 64% (91/143) of healthy and diarrheic calves, respectively. Diarrheic calves had higher odds of BCoV presence than healthy calves (OR: 2.16, 95% CI: 1.26 to 3.83, P = 0.004). A good agreement between PanCoV-RT-PCR and BCoV-RT-PCR to detect BCoV was identified (κ = 0.68, 95% CI: 0.392 to 0.967; P < 0.001). CONCLUSIONS AND CLINICAL IMPORTANCE: BCoV was more likely to be detected in diarrheic than healthy calves. The PanCoV-RT-PCR assay can be a useful tool to detect CoV samples from diarrheic calves.

Rho GTPases as therapeutic targets in cancer (Review).

Rho GTPases are key molecular switches controlling the transduction of external signals to cytoplasmic and nuclear effectors. In the last few years, the development of genetic and pharmacological tools has allowed a more precise definition of the specific roles of Rho GTPases in cancer. The aim of the present review is to describe the cellular functions regulated by these proteins with focus in deregulated signals present in malignant tumors. Finally, we describe the state of the art in search of different experimental therapeutic strategies with Rho GTPases as molecular targets.

Characterization of the Fecal Bacterial Microbiota of Healthy and Diarrheic Dairy Calves.

BACKGROUND: Neonatal diarrhea accounts for more than 50% of total deaths in dairy calves. Few population-based studies of cattle have investigated how the microbiota is impacted during diarrhea. OBJECTIVES: To characterize the fecal microbiota and predict the functional potential of the microbial communities in healthy and diarrheic calves. METHODS: Fifteen diarrheic calves between the ages of 1 and 30 days and 15 age-matched healthy control calves were enrolled from 2 dairy farms. The Illumina MiSeq sequencer was used for high-throughput sequencing of the V4 region of the 16S rRNA gene (Illumina, San Diego, CA). RESULTS: Significant differences in community membership and structure were identified among healthy calves from different farms. Differences in community membership and structure also were identified between healthy and diarrheic calves within each farm. Based on linear discriminant analysis effect size (LEfSe), the genera Bifidobacterium, Megamonas, and a genus of the family Bifidobacteriaceae were associated with health at farm 1, whereas Lachnospiraceae incertae sedis, Dietzia and an unclassified genus of the family Veillonellaceae were significantly associated with health at farm 2. The Phylogenetic Investigation of Communities Reconstruction of Unobserved States (PICRUSt) analysis indicated that diarrheic calves had decreased abundances of genes responsible for metabolism of various vitamins, amino acids, and carbohydrate. CLINICAL RELEVANCE: The fecal microbiota of healthy dairy calves appeared to be farm specific as were the changes observed during diarrhea. The differences in microbiota structure and membership between healthy and diarrheic calves suggest that dysbiosis can occur in diarrheic calves and it is associated with changes in predictive metagenomic function.

Cholangiohepatitis in Dairy Cattle: 13 Cases.

BACKGROUND: The signalment, clinicopathologic, bacteriological, histopathological, ultrasonographic characteristics, and the treatment and outcomes of adult cattle with cholangiohepatitis are poorly defined. ANIMALS: Thirteen Holstein cows with cholangiohepatitis. METHODS: Retrospective study of medical records of cattle admitted to the CHUV and the AVC between 1992 and 2012 and 2000 and 2012, respectively, for cattle older than 3 months of age with a histopathological diagnosis of cholangiohepatitis. Cholangiohepatitis was defined as the presence of portal inflammation surrounding or infiltrating bile ducts, with or without epithelial damage, and extending into the adjacent lobules. RESULTS: At the time of diagnosis of cholangiohepatitis, cows had decreased appetite (n = 7) or were anorectic (n = 6), had fever (n = 5), and had tachycardia (n = 8). Icterus was detected in 5 cows. Yellow discoloration was identified on the skin of the udder (n = 3), conjunctiva (n = 2), and vulva (n = 1). There was leukocytosis (n = 6), neutrophilia (n = 9), and hyperfibrinogenemia (n = 8). Alteration in the serum biochemistry profile included hyperglobulinemia (n = 8), hypoalbuminemia (n = 10), increased activity of GGT (n = 12), AST (n = 8), and ALP (n = 10), and hyperbilirubinemia (n = 10). Histopathological diagnosis included mild, subacute, nonsuppurative cholangiohepatitis (n = 4), mild suppurative cholangiohepatitis (n = 4), mild mixed (neutrophilic and lymphocytic) cholangiohepatitis (n = 3), and moderate, chronic, nonsuppurative cholangiohepatitis (n = 1). Six cows were discharged from the hospital, and 7 were euthanized. CONCLUSIONS AND CLINICAL IMPORTANCE: Cholangiohepatitis is a rare condition in adult cattle. Antemortem diagnosis can be challenging because clinical signs are unspecific.

Pharmacological inhibition of Rac1-PAK1 axis restores tamoxifen sensitivity in human resistant breast cancer cells.

Tamoxifen is a standard endocrine therapy for estrogen receptor positive breast cancer patients. Despite its success, development of resistance mechanisms is still a serious clinical problem. Deregulation of survival signaling pathways play a key role in tamoxifen resistance, being upregulation of Rac1-PAK1 signaling pathway one of the most important. Here, we report the development of the breast cancer cell model MCF7::C1199 having Rac1 enhanced activity with the aim of evaluating the role of Rac1 in acquired endocrine resistance. These cells not only showed distinctive features of Rac1-regulated process as increased migration and proliferation rates, but also showed that upregulation of Rac1 activity triggered a hormonal-independent and tamoxifen resistant phenotype. We also demonstrated that PAK1 activity increases in response to Tamoxifen, increasing phosphorylation levels of estrogen receptor at Ser305, a key phosphorylation site involved in tamoxifen resistance. Finally, we evaluated the effect of 1A-116, a specific Rac1 inhibitor developed by our group, in tamoxifen-resistant cells. 1A-116 effectively restored tamoxifen anti-proliferative effects, switched off PAK1 activity and decreased estrogen receptor phospho-Ser305 levels. Since combination schemes of novel targeted agents with endocrine therapy could be potential new strategies to restore tamoxifen sensibility, these results show that inhibition of Rac1-PAK1 signaling pathway may provides benefits to revert resistance mechanisms in endocrine therapies.

Comparison of bioaugmentation and biostimulation for the enhancement of dense nonaqueous phase liquid source zone bioremediation.

Two 11.7-m(3) experimental controlled release systems (ECRS), packed with sandy model aquifer material and amended with tetrachloroethene (PCE) dense nonaqueous phase liquid (DNAPL) source zone, were operated in parallel with identical flow regimes and electron donor amendments. Hydrogen Releasing Compound (Regenesis Bioremediation Products, Inc., San Clemente, California), and later dissolved lactate, served as electron donors to promote dechlorination. One ECRS was bioaugmented with an anaerobic dechlorinating consortium directly into the source zone, and the other served as a control (biostimulated only) to determine the benefits of bioaugmentation. The presence of halorespiring bacteria in the aquifer matrix before bioaugmentation, shown by nested polymerase chain reaction with phylogenetic primers, suggests that dechlorinating catabolic potential may be somewhat widespread. Results obtained corroborate that source zone reductive dechlorination of PCE is possible at near field scale and that a system bioaugmented with a competent halorespiring consortium can enhance DNAPL dissolution and dechlorination processes at significantly greater rates than in a system that is biostimulated only.

Expression of vascular endothelial growth factor, its receptor, and other angiogenic factors in human breast cancer.

Angiogenesis is essential for the growth and metastasis of solid tumors. In this study, we examined gene expression of vascular endothelial growth factor (VEGF); its receptor, flt-1; basic fibroblast growth factor; and transforming growth factors (TGFs) alpha and beta in 18 paired cases of human breast carcinomas and the adjacent nonneoplastic tissues. In all of the paired cases, VEGF expression was markedly increased in the carcinomas. In contrast, an insignificant difference was observed in the expression of flt-1, basic fibroblast growth factor, TGF-alpha, and TGF-beta between the malignant breast tissue and the nonneoplastic counterpart. Immunostaining showed variable VEGF positivity of the malignant cells, whereas the nonneoplastic breast epithelial cells were negative. The findings of this study suggest that VEGF is an important angiogenic factor in human breast cancer.

Telomerase as a Cancer Target. Development of New Molecules.

Telomeres are the terminal part of the chromosome containing a long repetitive and noncodifying sequence that has as function protecting the chromosomes. In normal cells, telomeres lost part of such repetitive sequence in each mitosis, until telomeres reach a critical point, triggering at that time senescence and cell death. However, in most of tumor cells in each cell division a part of the telomere is lost, however the appearance of an enzyme called telomerase synthetize the segment that just has been lost, therefore conferring to tumor cells the immortality hallmark. Telomerase is significantly overexpressed in 80-95% of all malignant tumors, being present at low levels in few normal cells, mostly stem cells. Due to these characteristics, telomerase has become an attractive target for new and more effective anticancer agents. The capability of inhibiting telomerase in tumor cells should lead to telomere shortening, senescence and apoptosis. In this work, we analyze the different strategies for telomerase inhibition, either in development, preclinical or clinical stages taking into account their strong points and their caveats. We covered strategies such as nucleosides analogs, oligonucleotides, small molecule inhibitors, G-quadruplex stabilizers, immunotherapy, gene therapy, molecules that affect the telomere/ telomerase associated proteins, agents from microbial sources, among others, providing a balanced evaluation of the status of the inhibitors of this powerful target together with an analysis of the challenges ahead.

Physicochemical Approach to Determine the Mechanism for Acid-Base Disorders in 793 Hospitalized Foals.

BACKGROUND: The quantitative effect of strong electrolytes, unmeasured strong anions (UAs), pCO2, and plasma protein concentrations in determining plasma pH can be demonstrated using the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess UAs in different species. HYPOTHESES: Strong ions are a major factor influencing changes in plasma pH of hospitalized foals. AG and SIG accurately predict severe hyper-L-lactatemia ([L-lac(-)] > 7 mmol/L). ANIMALS: Seven hundred and ninety three hospitalized foals < 7 days old. METHODS: Retrospective study. The relationship between measured pH and physicochemical variables, and the relationship between plasma [L-lac(-)] and AG and SIG, were determined using regression analyses. Optimal AG and SIG cut points to predict hyper-L-lactatemia were identified using an ROC curve analysis. RESULTS: Combined, the measured strong ion difference and SIG accounted for 54-69% of the changes in the measured arterial pH of hospitalized foals. AG and SIG were significantly associated with plasma [L-lac(-)] (P < .0001). The receiver operator characteristics (ROC) AUC of AG and SIG for prediction of severe hyper-L-lactatemia were 0.89 (95%CI, 0.8-0.95; P < .0001) and 0.90 (95%CI, 0.81-0.96; P < .0001), respectively. Severe hyper-L-lactatemia was best predicted by AG > 27 mmol/L (sensitivity 80%, 95%CI, 56-94, specificity 85%, 95%CI, 73-93; P < .0001) and SIG <-15 mmol/L (sensitivity 90%, 95%CI, 68-98; specificity 80%; 95%CI, 68-90; P < .0001). CONCLUSION AND CLINICAL RELEVANCE: Altered concentrations of strong ions (Na(+), K(+), Cl(-)) and UAs were the primary cause of acidemia of hospitalized foals. AG and SIG were good predictors of hyper-L-lactatemia and could be used as surrogate tests.