Developmental programming: impact of prenatal testosterone excess on insulin sensitivity, adiposity, and free fatty acid profile in postpubertal female sheep

Prenatal T excess causes reproductive and metabolic disruptions including insulin resistance, attributes of women with polycystic ovary syndrome. This study tested whether increases in visceral adiposity, adipocyte size, and total free fatty acids underlie the insulin resistance seen in prenatal T-treated female sheep. At approximately 16 months of age, insulin resistance and adipose tissue partitioning were determined via hyperinsulinemic euglycemic clamp and computed tomography, respectively, in control and prenatal T-treated females. Three months later, adipocyte size and free fatty acid composition were determined. Results revealed that at the postpubertal time points tested, insulin sensitivity was increased, visceral adiposity and adipocyte size in both the sc and the visceral compartments were reduced, and circulating palmitic acid was increased in prenatal T-treated females relative to controls. In parallel studies, 20-month-old prenatal T-treated females tended to have increased basal insulin to glucose ratio. Relative to earlier findings of reduced insulin sensitivity of prenatal T-treated females during early life and adulthood, these findings of increased insulin sensitivity and reduced adiposity postpubertally are suggestive of a period of developmental adaptation. The disruption observed in free fatty acid metabolism a few months later correspond to a time point when the insulin sensitivity indices of prenatal T-treated animals appear to shift toward insulin resistance. In summary, current findings of improved insulin sensitivity and reduced visceral adiposity in postpubertal prenatal T-treated sheep relative to our earlier findings of reduced insulin sensitivity during early postnatal life and adulthood are indicative of a period of developmental adaptation.

The influence of temperature and age on the T1 relaxation time of the equine distal limb

The extent of fat suppression using short tau inversion recovery (STIR) imaging is variable between horses. Our aim was to determine if patient's age and/or hoof temperature have an influence on the T(1) relaxation time of bone marrow in the equine distal limb, thereby affecting the suppression of fat signal. Magnetic resonance imaging was conducted on standing horses and cadaver samples using a low-field magnet (0.27 T). The hoof temperature was measured at the lateral side of the coronary band. A modified inversion recovery fast spin-echo (IR-FSE) sequence was used to measure the signal intensity for a range of inversion times (TIs) at six different regions of interest (ROI): (1) distal aspect of the proximal phalanx, (2) proximal aspect of the middle phalanx, (3) distal aspect of the middle phalanx, (4) navicular bone, (5) proximal aspect of the distal phalanx, and (6) distal aspect of the distal phalanx. The T(1) of the bone marrow in the equine distal limb was calculated from the results and was found to increase by 3.13 ± 0.08 (SE) ms/°C. There was no significant effect of age (2-16 years) but the T(1) values measured from the limbs of young (< 1 year) animals were considerably longer (32.6 ± 1.7 (SE) ms). Similar effects of temperature and age were found for all measured ROIs but there were significant differences in the mean values of T(1) , ranging from +7.7 (distal aspect of the distal phalanx) to -13.2 ms (distal aspect of the proximal phalanx).

Contrast-enhanced ultrasound of the feline kidney

Contrast-enhanced ultrasound offers a noninvasive means of subjectively and quantitatively evaluating renal perfusion in cats with renal disease, or in renal transplant patients. In this study, we characterized the pattern of ultrasonographic contrast enhancement in 16 normal feline kidneys in eight cats using contrast-enhanced power Doppler and contrast-enhanced harmonic ultrasound techniques. Mean time to peak contrast enhancement for the whole kidney was longer using contrast-enhanced harmonic ultrasound (16.8s, SD 4.7s) than contrast-enhanced power Doppler ultrasound (12.2s, SD 1.8s). The time to peak enhancement for the cortex alone in contrast-enhanced harmonic ultrasound was 13s (SD 3.2s), and for the renal medulla was 25.5s (SD 8.7s). The half time for washout of contrast agent was 39s (SD 14.5s) for contrast-enhanced harmonic ultrasound. The pattern of contrast enhancement in these normal feline kidneys can be used as normal reference values for the evaluation of clinical patients. Contrast-enhanced harmonic ultrasound may allow the differentiation between cortical and medullary perfusion patterns.

Esophageal dysfunction in dogs with idiopathic laryngeal paralysis: a controlled cohort study

OBJECTIVES

To compare esophageal function in dogs with idiopathic laryngeal paralysis (ILP) to age and breed matched controls; to determine if dysfunction is associated with aspiration pneumonia over 1 year; and to compare clinical neurologic examination of dogs with ILP at enrollment and at 1 year.

STUDY DESIGN

Prospective controlled cohort study.

ANIMALS

Dogs with ILP (n=32) and 34 age and breed matched healthy dogs.

METHODS

Mean esophageal score was determined for each phase of 3 phase esophagrams, analyzed blindly. After unilateral cricoarytenoid laryngoplasty, dogs with ILP were reexamined (including thoracic radiography) at 1, 3, 6, and 12 months. Neurologic status was recorded at enrollment, 6 and 12 months.

RESULTS

Esophagram scores in dogs with ILP were significantly higher in each phase compared with controls, most notably with liquid (P<.0001). Dysfunction was more pronounced in the cervical and cranial thoracic esophagus. Five dogs that had aspiration pneumonia during the study had significantly higher esophagram scores than dogs that did not develop aspiration pneumonia (P<.02). Ten (31%) ILP dogs had generalized neurologic signs on enrollment and all ILP dogs developed neurologic signs by 1 year (P<.0001). Conclusions- Dogs with ILP also have esophageal dysfunction. Postoperative aspiration pneumonia is more likely in dogs with higher esophagram scores. Dogs with ILP will most likely develop generalized neuropathy over the course of 1 year.

CLINICAL RELEVANCE

Esophagrams and neurologic examinations should be performed on all dogs with ILP.

ESOPHAGEAL DYSFUNCTION IN DOGS WITH IDIOPATHIC LARYNGEAL PARALYSIS: A CONTROLLED COHORT STUDY

Objectives: To compare esophageal function in dogs with idiopathic laryngeal paralysis (ILP) to age- and breed-matched controls; to determine if dysfunction is associated with aspiration pneumonia over one year; and to compare clinical neurologic examination of dogs with ILP at enrollment and one year.

Study Design: Prospective controlled cohort study

Animals or Sample Population: 32 dogs with ILP, and 34 age- and breed-matched healthy dogs.

Methods: Three-phase esophagrams were performed on all dogs. Blinded analyses of the esophagrams were performed, and the mean esophageal score determined in each phase. Following unilateral crico-arytenoid laryngoplasty, dogs with ILP were re-examined including thoracic radiography at 1, 3, 6 and 12 months. Neurologic status was recorded at enrollment, 6 and 12 months.

Results: Esophagram scores in dogs with ILP were significantly higher in each phase compared to the controls, most notably with liquid (P&lt;.0001). Dysfunction was more pronounced in the cervical and cranial thoracic esophagus. The 5 dogs that experienced aspiration pneumonia during the study period had significantly higher esophagram scores than the dogs that did not develop aspiration pneumonia (P&lt;0.02). Ten of the 32 (31%) dogs with ILP had generalized neurologic signs upon enrollment and all (100%) dogs developed neurologic signs over one year (P&lt;.0001).

Conclusions: Dogs with ILP also have esophageal dysfunction. Post-operative aspiration pneumonia is more likely in dogs with higher esophagram scores. Dogs with ILP will most likely develop generalized neuropathy over the course of a year.

Clinical Relevance: Esophagrams and neurologic examinations should be performed on all dogs with ILP.

Association between malignancy and sonographic heterogeneity in canine and feline abdominal lymph nodes

Abdominal lymph node enlargement is frequently noted sonographically. Certain sonographic features can be used to suggest whether lymphadenopathy is more likely benign or malignant. Specific changes in size, shape, echogenicity, and Doppler flow patterns have an association with malignancy. In this retrospective case-control study, the association between abdominal lymph node heterogeneity and malignancy was evaluated. Twenty-three canine and 18 feline patients with ultrasonographically heterogeneous abdominal nodes were evaluated for presence of benign or malignant lymphadenopathy. Controls were animals with lymph node enlargement of uniform echogeneity. Twenty-one (91%) of heterogeneous canine lymph nodes were malignant, and there was a significant association between heterogeneity and malignancy in canine abdominal lymph nodes (P= 0.024). Seven (63%) heterogeneous feline lymph nodes were malignant, with no significant association between heterogeneity and malignancy (P = 0.537).

RADIOGRAPHIC SENSITIVITY AND NEGATIVE PREDICTIVE VALUE FOR ACUTE CANINE SPINAL TRAUMA

The objectives of this study were to establish the sensitivity and negative predictive value of radiography for acute spinal osseous lesions in the canine trauma patient, and to evaluate the interobserver variability in radiographic assessment of the spine in traumatized dogs. This was a retrospective multiple observer blinded study. The study population included 30 canine patients that presented following acute trauma, with clinical signs attributable to the spinal column. Radiography and computed tomography (CT) were performed in all cases. Radiographic interpretation was performed independently by four observers with different experience levels who were blinded to clinical information (other than trauma) and the CT results. CT studies were interpreted by a further three radiologists who formed a consensus opinion on the presence of specific osseous lesions. Using the CT results as a gold standard, the sensitivities and negative predictive values of radiography for specific osseous lesions were calculated. Interobserver agreement was also evaluated. Radiography was found to have only a moderate sensitivity for fractures (72%) and subluxations (77.5%). Low negative predictive values were found for the presence of vertebral canal narrowing (58%) and fracture fragments within the vertebral canal (51%). Interobserver agreement was only moderate to fair for most lesion types. In conclusion, radiography cannot be used to reliably rule out potentially unstable acute vertebral lesions in the canine trauma patient, and further imaging is therefore often indicated in the patient with a high risk of such injuries.

Balloon dilatation of nasopharyngeal stenosis in a dog

CASE DESCRIPTION

A dog was examined because of a 6-month history of upper airway stridor that began after postoperative regurgitation of gastric contents.

CLINICAL FINDINGS

Constant stridor was evident during inspiration and expiration, although it was worse during inspiration. The stridor was no longer evident when the dog's mouth was manually held open. Computed tomography, rhinoscopy, and fluoroscopy were used to confirm a diagnosis of nasopharyngeal stenosis.

TREATMENT AND OUTCOME

The dog was anesthetized, and balloon dilatation of the stenosis was performed. Prednisone was prescribed for 4 weeks after the procedure to decrease fibrous tissue formation. Although the dog was initially improved, signs recurred 3.5 weeks later, and balloon dilatation was repeated. This time, however, triamcinolone was injected into the area of stenosis at the end of the dilatation procedure. Two months later, although the dog did not have clinical signs of stridor, a third dilatation procedure was performed because mild stenosis was seen on follow-up computed tomographic images; again, triamcinolone was injected into the area of stenosis at the end of the dilatation procedure. Three and 6 months after the third dilatation procedure, the dog reportedly was clinically normal.

CLINICAL RELEVANCE

Findings suggest that balloon dilatation may be an effective treatment for nasopharyngeal stenosis in dogs.