Diagnosis of mastitis for therapy decisions.

Identifying specific groups of mastitis pathogens by their growth on selective agars can help identify the pathogens that are present in mastitic milk samples. This article addresses issues that are essential in making good use of diagnostic procedures to improve udder health on dairies.     

Vitamin and mineral supplementation and rate of gain during the first trimester of gestation affect concentrations of amino acids in maternal serum and allantoic fluid of beef heifers

The objective of this study was to evaluate the effects of feeding vitamin and mineral (VTM) supplement and (or) rate of gain (GAIN) during early gestation on amino acid (AA) concentrations in allantoic fluid (ALF) and amniotic fluid (AMF) and maternal serum. Seventy-two crossbred Angus heifers (initial BW = 359.5 ± 7.1 kg) were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement with main effects of VTM supplement (VTM or NoVTM) and rate of gain (GAIN; low gain [LG], 0.28 kg/d, vs. moderate gain [MG], 0.79 kg/d). The VTM treatment (113 g•heifer⁻¹•d⁻¹, provided macro and trace minerals and vitamins A, D, and E to meet 110% of the requirements specified by the NASEM in Nutrient requirements of beef cattle. Washington, DC: The National Academies Press. doi:10.17226/19014, 2016) was initiated 71 to 148 d before artificial insemination (AI). To complete the factorial arrangement of treatments, at breeding heifers were either maintained on the basal diet (LG), or received MG diet which was implemented by adding a protein/energy supplement to the LG diet. Thirty-five gestating heifers with female fetuses were ovariohysterectomized on d 83 of gestation and maternal serum, ALF, and AMF were collected. Samples were analyzed for concentrations of neutral AA: Ala, Asn, Cys, Gln, Gly, Ile, Leu, Met, Phe, Pro, Ser, Thr, Trp, Tyr, and Val; cationic AA: Arg, His, and Lys; and anionic AA: Asp and Glu. In serum, a VTM × GAIN interaction (P = 0.02) was observed for Glu, with greater concentrations for VTM-LG than VTM-MG. Concentrations of serum Cys, Met, and Trp were greater (P ≤ 0.03) for MG than LG. In ALF, concentrations of Glu were affected by a VTM × GAIN interaction, where VTM-MG was greater (P < 0.01) than all other treatments. Further, ALF from VTM had increased (P ≤ 0.05) concentrations of His, Asp, and 12 of the 14 neutral AA; whereas GAIN affected concentrations of Arg, Cys, and Asp, with greater concentrations (P ≤ 0.05) in MG heifers. In AMF, AA concentrations were not affected (P ≥ 0.10) by VTM, GAIN, or their interaction. In conclusion, increased concentrations of AA in maternal serum and ALF of beef heifers were observed at d 83 of gestation in response to VTM supplementation and rate of gain of 0.79 kg/d, which raises important questions regarding the mechanisms responsible for AA uptake and balance between the maternal circulation and fetal fluid compartments.     

Comparison of microwave digestion with conventional wet ashing and dry ashing digestion for analysis of lead, cadmium, chromium, copper, and zinc in shellfish by flame atomic absorption spectroscopy

A closed vessel microwave digestion procedure was developed for shellfish samples. This procedure was compared with wet and dry ash procedures for levels of lead, cadmium, chromium, copper, and zinc. Results obtained for microwave and conventional wet ash digestion were comparable. The dry ashing procedure produced results consistently lower than either of the other methods. Recoveries ranged from 80-92% for microwave and wet ashing procedures and 54-72% for the dry ashing procedure. Accuracy was also determined by analyzing lobster hepatopancreas marine reference material. Values for Pb, Cd, and Cr fell within the range specified for the reference material for all 3 digestion procedures; however, values were lower for Cu and Zn. Results of this study show that microwave digestion is comparable to wet ashing.     

Major bacterial contribution to marine dissolved organic nitrogen

Next to N2 gas, the largest pool of reduced nitrogen in the ocean resides in the enormous reservoir of dissolved organic nitrogen (DON). The chemical identity of most of this material, and the mechanisms by which it is cycled, remain fundamental questions in contemporary oceanography. Amino acid enantiomeric ratios in the high molecular weight fraction of DON from surface and deep water in three ocean basins show substantial enrichment in D enantiomers of four amino acids. The magnitude and pattern of these D/L enrichments indicate that peptidoglycan remnants derived from bacterial cell walls constitute a major source of DON throughout the sea. These observations suggest that structural properties of specific bacterial biopolymers, and the mechanisms for their accumulation, are among the central controls on long-term cycling of dissolved organic nitrogen in the sea.     

Sonographic observations of the peripheral vasculature of the equine thoracic limb

Investigations of the equine peripheral vascular system have been constrained by the lack of a non-invasive method of examining the arteries and veins of the limbs of the conscious horse. Precise correlations were established between the gross anatomical features of the peripheral vessels and their B-mode sonographic appearance in each thoracic limb of 35 horses. A sonographic imaging protocol was established. Additional Doppler sonographic recordings defined the arterial waveforms and demonstrated that blood flow to the foot could be evaluated in the lateral proper digital artery, distal to the level of the coronary band. Valves (with 2-4 cusps) were identified in the lumina of the medial and lateral palmar common digital veins and those of the medial and lateral palmar proper digital veins. Spontaneous echo contrast, a smoke-like haze of echoic blood, was seen in the lateral and medial palmar common digital veins, the distal deep palmar venous arch and communicating branches, and the palmar proper digital veins, and occasionally seen in the distal deep palmar arterial arch and distal proper palmar digital arteries. The value of duplex sonography (B-mode and Doppler) for anatomical and physiological studies of the peripheral vasculature of the horse was clearly established. Such data could be applied to the investigation of diseases affecting the peripheral circulation.     

The Anatomy of the Parotid Duct (Ductus parotideus) of the Greyhound as Appreciated by the Sense of Touch

A method is described for the detailed palpation of the parotid duct of the live Greyhound; the method can also be applied to other dog breeds which have short facial hair. Transquilisation is needed where the dog concerned is nervous, boisterous or impatient.     

Effect of different adjuvants on the immune responses of cattle vaccinated with Mycobacterium tuberculosis culture filtrate proteins

The development of improved vaccines for bovine tuberculosis is urgently required as a cost effective solution for control and eventual eradication of tuberculosis in domestic animals. Studies in small animal models of tuberculosis have shown that vaccination with culture filtrate proteins (CFP), prepared from Mycobacterium tuberculosis or M. bovis, can induce cellular immune responses and confer a level of protection against aerogenic challenge with virulent mycobacteria. As a first step in the development of a mycobacterial CFP vaccine for protection of cattle against bovine tuberculosis, the immune responses of cattle vaccinated with short-term culture filtrate proteins (ST-CFP) from M. tuberculosis and formulated with different adjuvants were compared with those vaccinated with bacille Calmette-Guerin (BCG). The adjuvants included dimethyldioctyldecyl ammonium bromide (DDA), diethylaminoethyl (DEAE)-dextran, and ST-CFP adsorbed onto polystyrene beads. Vaccination with ST-CFP/DEAE-dextran induced high levels of interleukin-2 (IL-2) but low levels of interferon-gamma (IFN-gamma) from whole-blood cultures stimulated with M. tuberculosis ST-CFP in comparison with the strong IFN-gamma and IL-2 responses induced after vaccination with BCG. ST-CFP/DEAE-dextran also induced a strong antigen-specific immunoglobulin antibody response with both immunoglobulin G1 (IgG1) and IgG2 isotypes. Vaccination with ST-CFP/beads induced a weak IgG1-biased antibody response but no IFN-gamma or IL-2 response. DDA did not induce significant immune responses in animals vaccinated with ST-CFP. In comparison to the moderate delayed-type hypersensitivity (DTH) responses induced by vaccination with subcutaneous BCG, none of the ST-CFP vaccines induced a significant DTH response to either M. tuberculosis ST-CFP or bovine purified protein derivative (PPD). While the ST-CFP vaccines used in this study have not induced strong antigen-specific cellular immune responses in cattle comparable to those induced by BCG, they are immunogenic in cattle and it may be possible to overcome this problem by using adjuvants that more effectively promote IFN-gamma responses in this species.     

Primary pulmonary artery leiomyosarcoma in an adult dog

A 7-year-old neutered female English Setter presented with syncope, anemia, and weight loss. Clinical examination revealed a systolic murmur and echocardiography demonstrated a mass on the pulmonic valve. Postmortem examination confirmed the presence of a pulmonic valve mass that extended along the pulmonary trunk and into the left pulmonary artery. Multiple pale nodules were observed in the right lung. Microscopic examinations of the pulmonary artery mass and the lung nodules revealed a pleomorphic population of spindle cells often arranged in broad bands containing strap-like nuclei and eosinophilic cytoplasm devoid of cross striations. The neoplastic cells expressed vimentin and alpha-smooth muscle actin but did not express desmin, CD31, factor VIII, or S100. The presentation, histological features, immunocytochemical profiles, and behavior of this tumor were indicative of a primary pulmonary artery leiomyosarcoma with lung metastasis.