To investigate the effects of dexmedetomidine (DXM) and its subsequent reversal with atipamezole (APM) on the echocardiogram and circulating concentrations of cardiac biomarkers in cats.
14 healthy cats.
Cats underwent echocardiography and measurements of circulating cTn-I and NT-proBNP concentrations before (PRE) and during (INTRA) DXM sedation (40 µg/kg IM) and 2 to 4 (2H POST) and 24 (24H POST) hours after reversal with APM.
Administering DXM significantly decreased heart rate, right ventricular and left ventricular (LV) outflow tract velocities, and M-mode–derived LV free-wall thickness; increased LV end systolic diameter and volume; and caused valvar regurgitation. While sedative effects resolved within 25 minutes of APM reversal, the evolution of echocardiographic changes was mixed: LV ejection fraction and mitral valvar regurgitation score were different at 2H POST than at both INTRA and PRE (partial return toward baseline), LV end-diastolic volume was different PRE to INTRA and INTRA to 2H POST but not different PRE to 2H POST (full return toward baseline), and M-mode–derived LV free-wall thickness was significantly different from PRE to INTRA and PRE to 2H POST (no return toward baseline). Serum cTn-I and plasma NT-proBNP concentrations increased significantly with DXM, which remained significant 2H POST.
Administration of DXM and APM reversal produced changes in echocardiographic results and in circulating cTn-I and NT-proBNP concentrations. Understanding these changes could help veterinarians differentiate drug effects from cardiac disease.
Objective—To study the local immune response of
calves to bovine respiratory syncytial virus (BRSV)
infection with emphasis on IgE production and
cytokine gene expression in pulmonary lymph.
Animals—Twelve 6- to 8-week-old Holstein bull
calves. Six similar control calves were mock infected
to obtain control data.
Procedure—Lymphatic cannulation surgery was performed
on 12 calves to create a long-term thoracic
lymph fistula draining to the exterior. Cannulated
calves were exposed to virulent BRSV by aerosol.
Lymph fluid collected daily was assayed for BRSV and
isotype-specific IgE antibody, total IgG, IgA, IgM, and
protein concentrations. Interleukin-4 (IL-4), interleukin-
2 (IL-2), and interferon-γ were semi-quantitated
by reverse transcription-polymerase chain reaction
(RT-PCR). Cell counts and fluorescence-activated cell
scanner (FACSCAN) analysis of T-cell subsets were
performed on lymph cells.
Results—Calves had clinical signs of respiratory tract
disease during days 5 to 10 after infection and shed
virus. Bovine respiratory syncytial virus-specific IgE in
infected calves was significantly increased over baseline
on day 9 after infection. Mean virus-specific IgE
concentrations strongly correlated with increases in
severity of clinical disease (r = 0.903). Expression of
IL-2, IL-4, and interferon-γ was variably present in
infected and control calves, with IL-4 expression
most consistent during early infection.
Conclusions and Clinical Relevance—Infection with
BRSV was associated with production of BRSV-specific
IgE, and IL-4 message was commonly found in
lymph cells of infected calves. This finding supports
the concept that BRSV-induced pathophysiology
involves a T helper cell type-2 response. Effective
therapeutic and prophylactic strategies could, therefore,
be developed using immunomodulation to shift
the immune response more toward a T helper cell
type-1 response. (Am J Vet Res 2000;61:291–298)
OBJECTIVE To determine clinical relevance for quantitative and qualitative features of canine hepatic masses evaluated by use of triphasic CT and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography and to compare diagnostic accuracy of these modalities for predicting mass type on the basis of histopathologic classification.
ANIMALS 44 client-owned dogs.
PROCEDURES Dogs with histopathologic confirmation (needle core, punch, or excisional biopsy) of a hepatic mass were enrolled. Triphasic CT and B-mode, color flow, power, and pulsed-wave Doppler ultrasonography of each hepatic mass were performed. Seventy quantitative and qualitative variables of each hepatic mass were recorded by 5 separate observers and statistically evaluated with discriminant and stepwise analyses. Significant variables were entered in equation-based predictions for the histopathologic diagnosis.
RESULTS An equation that included the lowest delayed-phase absolute enhancement of the mass and the highest venous-phase mass conspicuity was used to correctly classify 43 of 46 (93.5%) hepatic masses as benign or malignant. An equation that included only the lowest delayed-phase absolute enhancement of the mass could be used to correctly classify 42 of 46 (91.3%) masses (with expectation of malignancy if this value was < 37 Hounsfield units). For ultrasonography, categorization of the masses with cavitations as malignant achieved a diagnostic accuracy of 80.4%.
CONCLUSIONS AND CLINICAL RELEVANCE Triphasic CT had a higher accuracy than ultrasonography for use in predicting hepatic lesion classification. The lowest delayed-phase absolute enhancement of the mass was a simple calculation that required 2 measurements and aided in the differentiation of benign versus malignant hepatic masses.