Non-antimicrobial approaches for the prevention or treatment of infectious bovine keratoconjunctivitis in cattle applicable to cow-calf operations: A scoping review.

Infectious bovine keratoconjunctivitis (IBK) is a common ocular disease in cattle that causes economic losses to producers and negatively impacts animal welfare. In a 2016 survey of cow-calf producers in California, IBK was identified as the disease for which antimicrobials are most frequently used. The presented scoping review examined the available literature for methods to prevent IBK and for alternatives to antimicrobials to treat the disease that can be applied in cow-calf operations. Online databases were searched for publications about IBK in cattle populations that were reported from 1950 to 2020. Citations were systematically evaluated in a multi-stage approach using commercial software and summarized in a scoping review format. For the studies included in the review, most research (n = 50) has focused on the development of vaccines for the prevention of IBK. Although the quality of publications has improved over time, there is a lack of consistent evidence for vaccine efficacy against IBK in post-2000 experimental and conventional vaccine trials. A systematic analysis of vaccine studies is warranted. A limited number (n = 6) of studies evaluated the prevention of IBK through fly control, where most have found efficacy of this control measure. Several treatment options (n = 5) that do not include the use of antimicrobials have been investigated but remain at the preliminary stage of testing. Differences in breed susceptibility has been demonstrated with breeds belonging to the Bos indicus subspecies less frequently affected compared to those belonging to the Bos taurus subspecies. Hereford cattle and those lacking pigmentation around the eyelid margin are more frequently affected than other breeds. At present, there are few evidence-based measures that producers can utilize to reduce the burden of IBK in their herds and more research into the efficacy of fly control measures, non-antimicrobial treatment options, the continued search for a viable vaccine, as well as identifying genetic markers associated with traits that confer resistance to the disease are needed.

One Health in food safety and security education: A curricular framework.

The challenges of producing and distributing the food necessary to feed an anticipated 9 billion people in developed and developing societies by 2050 without destroying Earth's finite soil and water resources present extremely complex problems that lack simple solutions. The ability of modern societies to adequately address these and other food-related problems will require an educated workforce trained not only in traditional food safety, security, and public health, but also in other areas including food production, sustainable practices, and ecosystem health. To help address the need for such an educated workforce, a curricular framework was developed to assist those tasked with designing education and training for future food systems workers. One sentence summary: A curricular framework for education and training in food safety and security was developed that incorporates One Health concepts.

An Integrated Circuit for Chip-Based Analysis of Enzyme Kinetics and Metabolite Quantification.

We have created a novel chip-based diagnostic tools based upon quantification of metabolites using enzymes specific for their chemical conversion. Using this device we show for the first time that a solid-state circuit can be used to measure enzyme kinetics and calculate the Michaelis-Menten constant. Substrate concentration dependency of enzyme reaction rates is central to this aim. Ion-sensitive field effect transistors (ISFET) are excellent transducers for biosensing applications that are reliant upon enzyme assays, especially since they can be fabricated using mainstream microelectronics technology to ensure low unit cost, mass-manufacture, scaling to make many sensors and straightforward miniaturisation for use in point-of-care devices. Here, we describe an integrated ISFET array comprising 2(16) sensors. The device was fabricated with a complementary metal oxide semiconductor (CMOS) process. Unlike traditional CMOS ISFET sensors that use the Si3N4 passivation of the foundry for ion detection, the device reported here was processed with a layer of Ta2O5 that increased the detection sensitivity to 45 mV/pH unit at the sensor readout. The drift was reduced to 0.8 mV/hour with a linear pH response between pH 2-12. A high-speed instrumentation system capable of acquiring nearly 500 fps was developed to stream out the data. The device was then used to measure glucose concentration through the activity of hexokinase in the range of 0.05 mM-231 mM, encompassing glucose's physiological range in blood. Localised and temporal enzyme kinetics of hexokinase was studied in detail. These results present a roadmap towards a viable personal metabolome machine.

Optical coherence tomography imaging of the basal ganglia: feasibility and brief review

Optical coherence tomography (OCT) is a promising medical imaging technique that uses light to capture real-time cross-sectional images from biological tissues in micrometer resolution. Commercially available optical coherence tomography systems are employed in diverse applications, including art conservation and diagnostic medicine, notably in cardiology and ophthalmology. Application of this technology in the brain may enable distinction between white matter and gray matter, and obtainment of detailed images from within the encephalon. We present, herein, the in vivo implementation of OCT imaging in the rat brain striatum. For this, two male 60-day-old rats (Rattus norvegicus, Albinus variation, Wistar) were stereotactically implanted with guide cannulas into the striatum to guide a 2.7-French diameter high-definition OCT imaging catheter (Dragonfly™, St. Jude Medical, USA). Obtained images were compared with corresponding histologically stained sections to collect imaging samples. A brief analysis of OCT technology and its current applications is also reported, as well as intra-cerebral OCT feasibility on brain mapping during neurosurgical procedures.

Optical coherence tomography imaging of the basal ganglia: feasibility and brief review.

Optical coherence tomography (OCT) is a promising medical imaging technique that uses light to capture real-time cross-sectional images from biological tissues in micrometer resolution. Commercially available optical coherence tomography systems are employed in diverse applications, including art conservation and diagnostic medicine, notably in cardiology and ophthalmology. Application of this technology in the brain may enable distinction between white matter and gray matter, and obtainment of detailed images from within the encephalon. We present, herein, the in vivo implementation of OCT imaging in the rat brain striatum. For this, two male 60-day-old rats (Rattus norvegicus, Albinus variation, Wistar) were stereotactically implanted with guide cannulas into the striatum to guide a 2.7-French diameter high-definition OCT imaging catheter (Dragonfly™, St. Jude Medical, USA). Obtained images were compared with corresponding histologically stained sections to collect imaging samples. A brief analysis of OCT technology and its current applications is also reported, as well as intra-cerebral OCT feasibility on brain mapping during neurosurgical procedures.

Preliminary investigation of cardiac troponin I concentration in cows with common production diseases.

BACKGROUND: Increased cTnI concentrations are associated with adverse outcomes in humans and animals. Limited information is available on the prognostic value of cTnI in cows. OBJECTIVE: To measure cTnI in cows with noncardiac diseases and evaluate the association of cTnI concentration with adverse outcomes such as death or early removal from the herd. ANIMALS: Thirty control and 53 diseased cows. METHODS: Serum cTnI concentrations were determined with a point-of-care immunoassay. Cows were diagnosed ante- or postmortem with metritis (n = 6), mastitis (n = 4), peritonitis (n = 6), LDA (n = 14), LDA and metritis (n = 4), pneumonia (n = 6), dystocia requiring cesarean section (n = 5), and downer cow syndrome (n = 8). Animal survival was determined for up to 2 months after presentation. RESULTS: The immunoassay showed reliability for the detection of bovine cTnI. Cows with LDA and metritis (P < .05), peritonitis (P < .05), LDA (P < .001), dystocia requiring cesarean section (P < .01), and downer cow syndrome (P < .001) had higher cTnI concentrations than control cows. The odds of a negative outcome (death or culling) for cows with cTnI concentrations of ≥ 0.05, ≥ 0.1, ≥ 0.2, and ≥ 0.5 ng/mL were 2.4, 2.9, 4.8, and 6.2, respectively. CONCLUSION: Cows with noncardiac diseases may have some degree of myocardial injury. The magnitude of cTnI increased may assist clinicians in evaluating the risk of an adverse outcome and help guide decision-making regarding treatment and prognosis.

Influence of the refractive index core profile on modal scattering of terminated two-dimensional waveguides.

We examine the influence of the refractive index core profile on the modal scattering of abruptly terminated slab waveguides. The analysis is based on the integral equation method with accelerating parameters, while for the field description in the waveguide core, an appropriate Lanczos-Fourier expansion is employed. The electric-field distribution on the terminal plane, the reflection and transformation coefficient of the TE guided modes, and the far-field radiation pattern are computed. Numerical results are presented for slab waveguides with step, linear, and parabolic refractive index profiles of the core. Finally, several approximate analytical solutions are derived to study the problem in question and to explain the results obtained.

Reflectivity properties of an anisotropic slab waveguide with isolated substrate.

The scattering properties for both TE and TM modes of an abruptly ended two-layered slab waveguide with anisotropic core and isolated substrate are examined by an improved iteration technique, which is based on the integral equation method with accelerating parameters. The relative dielectric constants of the core for the three Cartesian directions are considered to be different, but cases with isotropic core are also considered. The electric field distribution on the terminal plane and the reflection coefficients of the dominant TE and TM guided modes, as well as the near-field distribution and the far-field radiation pattern, are computed, while numerical results are presented for several cases of the core anisotropy.

Metal iris influence on guided-mode diffraction.

The effects of the presence of metal irises on guided-mode propagation through a symmetrical three-layer slab waveguide are examined by using the integral equation method. The aperture electric field distribution is expressed in terms of a finite series of Chebyshev polynomials. The modal reflection and transmission coefficients, the near-field structure, and the far-field radiation pattern are calculated, while numerical results are presented for several iris apertures.

Reflectivity of buried slab waveguides.

The scattering properties of an abruptly ended buried slab waveguide for both TE and TM modes are examined by an improved iteration technique that is based on the integral equation method with "accelerating" parameters. The waveguide is considered a symmetrical slab, for which the weakly guiding conditions are invalid, and it is embedded in a different dielectric material. The tangential electric field distribution on the terminal plane, the reflection coefficient of the first TE and TM guided modes, and the far-field radiation pattern are computed. Numerical results are presented for several ended waveguides, while special attention is given to the far-field radiation pattern rotation and the terminal field distributions.

Cloning and characterization of a Moraxella bovis cytotoxin gene.

OBJECTIVE: To identify the Moraxella bovis cytotoxin gene. PROCEDURE: Hemolytic and nonhemolytic strains of M. bovis were compared by use of western blotting to identify proteins unique to hemolytic strains. Oligonucleotide primers, designed on the basis of amino acid sequences of 2 tryptic peptides derived from 1 such protein and conserved regions of the C and B genes from members of the repeats in the structural toxin (RTX) family of bacterial toxins, were used to amplify cytotoxin-specific genes from M. bovis genomic DNA. Recombinant proteins were expressed, and antisera against these proteins were produced in rabbits. RESULTS: Several proteins ranging in molecular mass from 55 to 75 kd were unique to the hemolytic strain. An open reading frame encoding a 927-amino acid protein with a predicted molecular mass of 98.8 kd was amplified from M. bovis genomic DNA. The deduced amino acid sequence encoded by this open reading frame was homologous to RTX toxins. Antisera against the recombinant carboxy terminus encoded by this open reading frame neutralized hemolytic and cytolytic activities of native M. bovis cytotoxin. CONCLUSIONS AND CLINICAL RELEVANCE: A gene was identified in M bovis that encodes a protein with sequence homology to other RTX toxins. Results of cytotoxin neutralization assays support the hypothesis that M. bovis cytotoxin is encoded by this gene and belongs in the RTX family of bacterial exoproteins. Identification of this gene and expression of recombinant cytotoxin could facilitate the development of improved vaccines against infectious bovine keratoconjunctivitis.

Efficacy of florfenicol for treatment of naturally occurring infectious bovine keratoconjunctivitis.

OBJECTIVE: To determine the efficacy of florfenicol for treatment of calves with naturally occurring infectious bovine keratoconjunctivitis (IBK). DESIGN: Randomized controlled field trial. ANIMALS: 63 beef calves and 80 dairy calves between 4 and 12 months of age. PROCEDURE: Calves were randomly assigned to 1 of 3 treatment groups. Calves in the SC treatment group received a single dose of florfenicol (40 mg/kg [18.2 mg/lb of body weight), SC, on day 0. Calves in the IM treatment group received florfenicol (20 mg/kg [9.1 mg/lb]), IM, on days 0 and 2. Calves in the control group received injections of saline solution (0.9% NaCl), IM, on days 0 and 2. Calves were reevaluated every other day for 20 days after treatment. RESULTS: Corneal ulcers healed by day 20 in 48 of 49 (98%) calves treated with florfenicol IM, 39 of 42 (93%) calves treated with florfenicol SC, and 33 of 52 (63%) control calves. CONCLUSIONS AND CLINICAL RELEVANCE: Florfenicol administered SC (1 dose) or IM (2 doses 48 hours apart) was effective for treatment of calves with naturally occurring IBK.

Efficacy of florfenicol in the treatment of experimentally induced infectious bovine keratoconjunctivitis.

OBJECTIVE: To evaluate efficacy of florfenicol in an induced model of infectious bovine keratoconjunctivitis, using a blinded randomized, controlled trial. ANIMALS: 48 male Holstein calves, 2 to 4 months old. PROCEDURE: Moraxella bovis infection was induced in all calves. When corneal ulcers developed, each calf was assigned randomly to 1 of 3 treatment groups, using a block design determined by corneal ulcer size (day 0). Calves were treated with florfenicol (20 mg/kg of body weight, IM) on days 0 and 2 (IM group; n = 16). Calves of a second group received a single dose of florfenicol (40 mg/kg, SC) on day 0 (SC group; n = 16). The third group of calves was not treated (control group; n = 16). Corneal ulcers were photographed, and each calf was assessed for 30 days after treatment for 10 clinical signs of infection. Corneal ulcer surface areas were measured, and clinical scores were calculated. Ocular secretions for microbiologic culture were obtained weekly from each eye. RESULTS: A Cox regression model indicated that, after adjustment for initial ulcer size, healing rates were 6.2 and 4.8 times greater in calves of the IM and SC groups, respectively, compared with the control group. Clinical scores and surface area measurements for treatment groups were significantly smaller than those for controls during posttreatment weeks 1 through 4. From day 8 through day 29, M bovis was isolated from ocular secretions of 14 of 16 control calves and 1 of 32 treated calves. CONCLUSIONS AND CLINICAL RELEVANCE: Parenterally administered florfenicol reduces corneal ulcer healing time, lessens clinical severity, and reduces the amount of bacterial shedding from calves infected with M bovis.

Treatment of hypernatremia in an acidotic neonatal calf.

A 7-day-old Jersey calf was evaluated because of diarrhea and pneumonia. The calf was hypernatremic, hypoproteinemic, and acidemic, and was treated initially with i.v. administration of fluids with sodium concentration (175 mEq/L) similar to the calf's serum sodium concentration. Sodium concentration of the administered fluids was gradually decreased over the following days, but the calf's serum sodium concentration decreased too rapidly, and the calf developed neurologic signs attributed to cerebral edema. Treatment with mannitol and i.v. administration of fluids with a higher concentration of sodium resulted in abatement of clinical signs. In calves, hypernatremia may develop over several days. Prescribing traditional isotonic or hypotonic fluids in such cases will be harmful, because during chronic hypernatremia, the brain's adaptive mechanisms involve accumulation of organic osmoles that may take several days to equilibrate across cell membranes, and cerebral edema may result. Administration of fluids containing sodium concentration approximately equal to the patient's measured serum sodium concentration is required to decrease serum sodium concentration more slowly than is possible with traditional isotonic fluids.

Hemolysis associated with water administration using a nipple bottle for human infants in juvenile pygmy goats.

A 4-month-old, 6.8-kg, castrated male pygmy goat was examined for recurrent episodic fever and red urine of 7 days' duration. A second, 3-month-old, 7-kg, intact female pygmy goat was presented for similar clinical signs. The red discoloration of the urine in each case was determined to be due to hemolysis with subsequent hemoglobinuria. In both cases, hemolysis and hemoglobinuria were closely associated with the goats consuming large volumes of water from a human infant's nipple bottle. A diagnosis of water intoxication-induced hemolysis and hemoglobinuria was made. Episodes of hemoglobinuria in the first case were consistently associated with dilute (specific gravity < 1.010) urine. Water intoxication has been associated with bottle-feeding in human infants and is also widely reported in human psychiatric patients. The small erythrocytes in goats appear to be the most sensitive of the domestic species to hypotonicity-induced hemolysis.

Aneurysm of the cranial mesenteric artery in a cow.

Exploratory laparotomy of an adult dairy cow, examined because of acute signs of persistent abdominal pain, revealed a firm pulsatile mass with associated fremitus just distal to the origin of the cranial mesenteric artery. The cow died acutely 2.5 days after surgery. A dilated, thin-walled, sacculated aneurysm, which had ruptured, was located along the proximal portion of the cranial mesenteric artery. It was postulated that the aneurysm developed secondary to structural defects in the arterial wall, but caused no clinical signs until enlargement and local tissue stretching or circulatory disturbances caused intestinal ischemia, resulting in abdominal pain. Aneurysms of visceral arteries in cattle should be considered as another differential diagnosis for signs of abdominal pain after more common causes such as severe bloat, mesenteric root volvulus, intussusception, cecal dilatation/volvulus, and uterine torsion have been excluded.

Characterization of BPV-like DNA in equine sarcoids.

The DNA from equine sarcoid samples from New York State and Switzerland was isolated and probed with bovine papillomavirus type 1 (BPV-1) to determine if BPV genomes were present. Twelve of 13 sarcoids from New York State and 17/20 sarcoids from Switzerland contained DNA that hybridized to the BPV-1 probe. Restriction enzyme analysis of the positive samples demonstrated restriction fragment profiles characteristic of BPV-1 in 22 sarcoids and restriction fragment profiles characteristic of bovine papillomavirus type 2 (BPV-2) in 7 sarcoids. In addition, three tissues histologically diagnosed as pyogranulomatous dermatitis, fibropapilloma, and fibrosarcoma contained BPV-like DNA. Tissues with BPV-1-like and BPV-2-like DNA contained an average of 285.7 (21 to 808) and 125.8 (2 to 762) BPV-like genomes per cell, respectively. Minor differences in the restriction fragment profiles of the BPV-like DNA and evidence for partial BPV-like genomes were found in some sarcoids. BPV-like DNA was not detected in lymphocyte DNA from sarcoid-affected horses. These results confirm previous observations and support the hypothesis that bovine papillomavirus, or a very similar virus, is linked to the cause of equine sarcoid.

Evaluation of breed as a risk factor for sarcoid and uveitis in horses.

The relationship between breed and the risk of developing sarcoid tumours or uveitis of unknown etiology was evaluated in a retrospective study of 16242 equine cases admitted between 1975 and 1987 to the New York State College of Veterinary Medicine Large Animal Hospital, and 3198 equine tissue samples sent to the New York State Veterinary Diagnostic Laboratory between 1977 and 1987. Of 120 sarcoid cases from the Large Animal Hospital, sarcoids were twice as likely to develop in Quarter Horses (odds ratio, OR = 1.8, P less than 0.05) relative to Thoroughbreds and less than half as likely to develop in Standardbreds (OR = 0.2, P less than 0.001) relative to Thoroughbreds. Similarly, of 376 sarcoid cases from the Diagnostic Laboratory, Quarter Horses had a significantly higher risk of developing sarcoid (OR = 2.0, P less than 0.001) relative to Thoroughbreds, while Standardbreds had a significantly lower risk of developing sarcoid (OR = 0.5, P less than 0.05) relative to Thoroughbreds. In the uveitis diagnosis category, Appaloosas had a significantly higher risk of developing uveitis (OR = 6.4, P less than 0.001) relative to Thoroughbreds, while Standardbreds had a significantly lower risk of developing uveitis (OR = 0.4, P less than 0.05) relative to Thoroughbreds.