Prenatal immune stimulation alters the postnatal acute phase and metabolic responses to an endotoxin challenge in weaned beef heifers.

This study evaluated whether administration of lipopolysaccharide (LPS) at each trimester of gestation would alter the acute phase (APR) and metabolic responses to a postnatal LPS challenge in weaned heifers. Pregnant crossbred multiparous cows (n = 50) were randomized into prenatal immune stimulation (PIS; n = 24; administered 0.1 µg/kg BW LPS subcutaneously at 71 ± 2, 170 ± 2 and 234 ± 2 d of gestation) and saline (CON; n = 26) groups. From these treatment groups, heifer calves (n = 12 PIS and 11 CON) were identified at weaning (244 ± 3 d of age) to receive an LPS challenge. On d 0, heifers were fitted with vaginal temperature (VT) devices, jugular catheters, and moved into individual stalls. On d 1, heifers were challenged i.v. with LPS (0.5 µg/kg BW) at 0 h. Blood samples were collected and sickness behavior scores (SBS) recorded at 0.5 h intervals from -2 to 8 h and at 24 h relative to LPS challenge. Serum was analyzed for cortisol, cytokines, glucose, non-esterified fatty acids (NEFA), and serum urea nitrogen (SUN) concentrations. Baseline VT was lesser in PIS heifers from -11 to -5 h pre-LPS (treatment × time: P < 0.01) compared to the CON; however, the post-LPS VT response did not differ between treatments (P = 0.89). There was a treatment × time interaction (P < 0.01) for SBS with PIS heifers having lesser SBS from 0.5 to 2 h post-LPS compared to CON. There was a treatment × time interaction (P = 0.03) for cortisol with PIS heifers having greater cortisol at 0.5, 3, 3.5, 5.5 and 6.5 h post-LPS compared to CON. There were treatment × time interactions for the post-LPS cytokine responses (P ≤ 0.05). Specifically, PIS heifers had greater TNF-α from 1.5 to 2 h, yet less TNF-α at 3 h than CON (P < 0.01), and PIS heifers had greater IFN-γ from 3.5 to 5.5 h post-LPS than CON (P < 0.01). In contrast, IL-6 was less in PIS than CON heifers from 1.5 to 8 h post-LPS (P < 0.001). Glucose concentrations were greater in PIS heifers at -1 h, but less at 2, 3 and 5.5 h compared to CON (treatment × time: P < 0.01). Serum NEFA concentrations were greater (P = 0.04) in PIS than CON heifers. There was a treatment × time interaction (P < 0.01) for SUN with PIS heifers having greater SUN concentrations at -2, -1.5, 2, 3, 6.5 and 24 h than CON. These data demonstrate that in utero exposure to multiple low doses of endotoxin has lasting physiological and immunological effects when the offspring encounter a similar postnatal immunological insult.

Development of application protocols of the Emit® II Plus 6-Acetylmorphine Assay on the ADVIA® 1800 and 2400 Chemistry Systems.

New application protocols for the Emit(®) II Plus 6-Acetylmorphine Assay for human urine screening have been developed on the ADVIA(®) 1800 and 2400 Chemistry Systems. Precision was evaluated at the cutoff and ±25% controls. Recovery and linearity were studied by spiking 6-acetylmorphine (6-AM) into human urine pools. Method comparison was evaluated using urine specimens and the results were compared to those obtained from the predicate Analyzer (V-Twin(®)). Cross-reactivity with structurally related drugs was assessed at high cross-reactant concentrations. Potential interferences were assessed in the presence of 7.5 and 12.5 ng/mL of 6-AM. The qualitative repeatability coefficients of variation (CV's) ranged from 0.40 to 0.90% and the within-lab CV's ranged from 1.3 to 3.5%. In analyte units (ng/mL), the repeatability CV's ranged from 1.9 to 4.3% and the within-lab CV's ranged from 3.7 to 6.1%. The limit of detection of the assay was found to be 2.5 ng/mL on both instruments. Recovery was within 20% of expected value. Linearity was 2.5-20 ng/mL. Method comparison showed 100% agreement with the predicate analyzer. The assay had minimal cross-reactivity to structurally related opioids including with morphine, morphine-3-glucuronide, morphine-6-glucuronide. No interference was observed with endogenous interferences.

Cefoxitin disk diffusion screen for confirmation of oxacillin-resistant Staphylococcus aureus isolates and utility in the clinical laboratory.

One hundred Vitek-2 identified oxacillin resistant S. aureus (ORSA) isolates were tested by oxacillin screen-plate (OXA-plate) and cefoxitin disk (FOX-disk) for confirmation of oxacillin resistance. Ninety-five of 100 confirmed oxacillin resistant by both, 3 of 5 were oxacillin susceptible by both and mecA negative, and 2 of 5 were oxacillin susceptible by OXA-plate, resistant by FOX-disk and mecA positive. The FOX-disk out-performed the OXA-plate for ORSA confirmation and can be performed using standard laboratory techniques.