Serum cortisol concentrations in dogs with pituitary-dependent hyperadrenocorticism and atypical hyperadrenocorticism.

BACKGROUND: Atypical hyperadrenocorticism (AHAC) is considered when dogs have clinical signs of hypercortisolemia with normal hyperadrenocorticism screening tests. HYPOTHESIS/OBJECTIVES: To compare cortisol concentrations and adrenal gland size among dogs with pituitary-dependent hyperadrenocorticism (PDH), atypical hyperadrenocorticism (AHAC), and healthy controls. ANIMALS: Ten healthy dogs, 7 dogs with PDH, and 8 dogs with AHAC. METHOD: Dogs were prospectively enrolled between November 2011 and January 2013. Dogs were diagnosed with PDH or AHAC based on clinical signs and positive screening test results (PDH) or abnormal extended adrenal hormone panel results (AHAC). Transverse adrenal gland measurements were obtained by abdominal ultrasound. Hourly mean cortisol (9 samplings), sum of hourly cortisol measurements and adrenal gland sizes were compared among the 3 groups. RESULTS: Hourly (control, 1.4 ± 0.6 µg/dL; AHAC, 2.9 ± 1.3; PDH, 4.3 ± 1.5) (mean, SD) and sum (control, 11.3 ± 3.3; AHAC, 23.2 ± 7.7; PDH, 34.7 ± 9.9) cortisol concentrations differed significantly between the controls and AHAC (P < .01) and PDH (P < .01) groups. Hourly (P < .01) but not sum (P = .27) cortisol concentrations differed between AHAC and PDH dogs. Average transverse adrenal gland diameter of control dogs (5.3 ± 1.2 mm) was significantly less than dogs with PDH (6.4 ± 1.4; P = .02) and AHAC (7.2 ± 1.5; P < .01); adrenal gland diameter did not differ (P = .18) between dogs with AHAC and PDH. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum cortisol concentrations in dogs with AHAC were increased compared to controls but less than dogs with PDH, while adrenal gland diameter was similar between dogs with AHAC and PDH. These findings suggest cortisol excess could contribute to the pathophysiology of AHAC.

Quantification of hepatic and renal cortical echogenicity in clinically normal cats.

OBJECTIVE: To quantitatively determine echogenicity of the liver and renal cortex in clinically normal cats. ANIMALS: 17 clinically normal adult cats. PROCEDURE: 3 ultrasonographic images of the liver and the right kidney were digitized from video output from each cat. Without changing the ultrasound machine settings, an image of a tissue-equivalent phantom was digitized. Biopsy specimens of the right renal cortex and liver were obtained for histologic examination. Mean pixel intensities within the region of interest (ROI) on hepatic, renal cortical, and tissue-equivalent phantom ultrasonographic images were determined by histogram analysis. From ultrasonographic images, mean pixel intensities for hepatic and renal cortical ROI were standardized by dividing each mean value by the mean pixel intensity from the tissue-equivalent phantom. RESULTS: The mean (+/- SD) standardized hepatic echogenicity value was 1.06 +/- 0.02 (95% confidence interval, 1.02 to 1.10). The mean standardized right renal cortical echogenicity value was 1.04 +/- 0.02 (95% confidence interval, 1.01 to 1.08). The mean combined standardized hepatic and renal cortical echogenicity value was 1.02 +/- 0.05 (95% confidence interval, 0.99 to 1.04). CONCLUSIONS AND CLINICAL RELEVANCE: Quantitative determination of hepatic and renal cortical echogenicity in cats is feasible, using histogram analysis, and may be useful for early detection of diffuse parenchymal disease and for serially evaluating disease progression.

Detection of deep venous thrombosis by DMP 444, a platelet IIb/IIIa antagonist: a preliminary report.

BACKGROUND: We report a method for detection of deep venous thrombosis with a technetium 99m-labeled peptide (DMP 444). The N-methyl-arginine-glycine-aspartic acid sequence on DMP 444 binds the glycoprotein IIb/IIIa receptor on activated platelets (inhibition constant [IC50] for fibrinogen binding = 6 nmol/L). METHODS: DMP 444 (23 to 27 mCi) was injected into 11 patients with clinical suspicion of deep venous thrombosis, diagnostic confirmation by ultrasound, and a positive D-dimer test result. Planar images in the anterior and posterior projections were obtained at 10 to 40 minutes, 50 to 80 minutes, and 120 to 150 minutes after injection. RESULTS: No clinically significant adverse effects were noted after DMP 444 administration. One patient (excluded from the analysis) withdrew consent, so image acquisition was not complete. By 10 to 40 minutes after injection, 8 of 10 patients demonstrated an area of increased activity that was clearly related to the abnormality noted on ultrasound. Most patients were taking warfarin (Coumadin) and heparin (n = 8) or heparin (n = 1) and warfarin (n = 1) alone at the time of the imaging. The average time from onset of symptoms to injection of DMP 444 was 5 days (range 1 to 18 days). CONCLUSION: These preliminary human studies indicate that DMP 444 is safe and may be of value in the diagnosis of deep venous thrombosis.

The effects of a unilateral ultrasound-guided renal biopsy on renal function in healthy sedated cats.

Complications of renal biopsies are well documented except for the change in renal function after a biopsy. Eighteen healthy, adult cats were divided into two groups (n = 9 cats/group). For the measurement of global and split renal function, Group 1 used the renal uptake of 99mTc-DTPA and Group 2 used the renal uptake of 99mTc-MAG3. Scintigraphic data were collected on days (-4), (-3), 0, 1, 2, and 4 post renal biopsy. Using ultrasound guidance, biopsies were taken from the right renal cortex on dO, before acquiring scintigraphic images. P - values less than 0.10 were considered significant due to the limited number of observations. The only statistically significant change (p = 0.08) in global renal function detected was by day following a unilateral renal biopsy. Cats imaged using 99mTc-MAG3 had discernible liver activity. A unilateral, ultrasound guided renal biopsy has minimal effect on renal function in normal, healthy sedated cats.

Aortoiliac thrombus secondary to a mineralized arteriosclerotic lesion.

A 12-year-old, neutered female, Siberian Husky dog presented with a hind limb weakness of one month duration. To facilitate making a diagnosis multiple imaging modalities were performed. These modalities included radiography, ultrasonography, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) and selective angiography of the abdominal aorta. In this dog, the MRI/MRA studies provided the first documentation of the external iliac thrombi and the collateral circulation via the lumbar arteries. At necropsy, an aortoiliac thrombus caused by a mineralized arteriosclerotic plaque was noted.

Placement of an intracoronary stent via translumbar puncture.

Translumbar puncture for access to the central arterial tree has been used for aortography and for selective coronary angiography in selected patients where conventional peripheral access is not possible. A single case report of coronary angioplasty through this access technique is available in the literature. We report a case of coronary stent placement using the translumbar approach to access the coronary arteries.

Trends in costs of percutaneous transluminal coronary angioplasty.

OBJECTIVE: To evaluate recent trends in the cost of percutaneous transluminal coronary angioplasty (PTCA), particularly the impact of newer technology and changing patient profile. STUDY DESIGN: Retrospective study with a 6-month follow up. PATIENTS AND METHODS: We compared the data on two groups of 100 consecutive patients admitted for elective PTCA at Yale-New Haven Hospital in 1995 and 1996. Hospital records, cineangiograms, and hospital cost accounting system were reviewed, and 6-month clinical outcomes were obtained from telephone interviews and medical chart review. RESULTS: Demographic and clinical characteristics did not differ between the 1995 and 1996 groups of patients, nor was a difference detected in in-hospital and 6-month clinical outcomes between 1995 and 1996. Angiographic features of treated lesions were different between the two groups, with a significantly higher frequency of type C and totally occluded lesions in 1996 (p = 0.002 and p = 0.04, respectively). The total hospital costs were higher in 1996 compared with 1995 ($11,799 +/- $6189 vs $10,087 +/- $5608; p = 0.04). This difference persisted after adjustment for changes in patient population. The major factor responsible for escalating costs was a 45% increase in catheterization laboratory costs ($8575 +/- $4524 in 1996 vs $5916 +/- $3030 in 1995; P < 0.0001). In contrast, the noncatheterization costs decreased substantially during this period, largely as a result of an approximately 33% decrease in length of stay (3.75 +/- 2.66 days in 1995 vs 2.57 +/- 1.99 days in 1996; P = 0.0005). In a multiple linear regression model, the most important determinants of cost were lesion characteristics, stent use, and radiographic contrast volume. CONCLUSIONS: Despite cost reduction efforts, the costs of PTCA are rising because of increased consumption of resources in the catheterization laboratory.

Use of the holmium yttrium aluminum garnet laser for percutaneous thoracolumbar intervertebral disk ablation in dogs.

OBJECTIVE-To evaluate a laser ablation-technique for treatment of thoracolumbar intervertebral disk disease in dogs. DESIGN-Prospective case series. ANIMALS-33 dogs with signs of recurrent back pain associated with intervertebral disk disease after the initial episode had been managed conservatively for a minimum of 2 weeks. PROCEDURE-Spinal needles were placed percutaneously through the annulus fibroses to permit delivery of an optical fiber into the nucleus pulposes of thoracolumbar intervertebral disks T10-11 through L3-4. Fluoroscopy was used to guide needle placement. Holmium yttrium aluminum garnet laser energy then was used to ablate the contents of each selected intervertebral disk. Intervals from time of treatment to time of assessment ranged from 3 to 114 weeks. RESULTS-All dogs recovered without complication. Results of follow-up radiography and histologic evaluation indicated that percutaneous holmium yttrium aluminum garnet laser ablation reduces the volume of nucleus pulposus in treated disks. CLINICAL IMPLICATIONS-Used as a clinical treatment and prophylactically, this minimally invasive procedure should prevent further extrusion of partially herniated disks and should reduce the chances of subsequent herniation of disks at other treatment sites.

Bronchial cartilage dysplasia with multifocal lobar bullous emphysema and lung torsions in a pup.

Bronchial cartilage dysplasia is believed to have caused lobar bullous emphysema in a 5-month-old Chow Chow that had exercise intolerance, progressive dyspnea, and episodic cough. Radiography of the thorax revealed hyperlucency of the left hemithorax, displacement of the mediastinum and heart to the right, and flattening of the diaphragm. The pup died shortly after the radiographs were obtained. Necropsy revealed massive hyperinflation with 180 degrees torsion of the cranial portion of the left cranial lung lobe, and hyperinflation with less than 180 degrees torsion of the right accessory lung lobe. Histologic examination of the affected lung lobes revealed a lack of bronchial cartilage, loss and displacement of alveolar walls, and bulla formation that resembled congenital (infantile) lobar emphysema of human beings. In this pup, lung lobe torsions may have been predisposed by bronchial cartilage dysplasia.

Radiographic development of canine hip dysplasia.

The radiographic changes observed in the development of CHD in the dog are complex and not fully understood despite years of research. Moderate to severe CHD is relatively easy to diagnose using standard radiographic views and evaluation techniques. However, early detection of mild or borderline CHD continues to be difficult to reliably detect radiographically. Efforts continue to be made to develop new views, techniques, and evaluation methods that will improve the radiographic evaluation of CHD. Until better methods are proven, the standard ventrodorsal leg extended view, evaluated by an experienced reviewer, will remain the method of choice for radiographic detection of CHD.

Mercury-induced renal autoimmunity in the MAXX rat.

Inbred Brown Norway (BN) rats treated with mercuric chloride develop autoantibodies to renal basement membranes and an immunologically mediated membranous glomerulonephritis. To date, this experimental rat model of chemically induced autoimmunity has been obtained only in the BN strain, whereas rats from 17 other strains were found to be resistant. This is a disadvantage for mechanistic studies, especially since BN rats have poor fertility. In the present paper we report that the same model can be obtained in another inbred strain of rats, the MAXX, which after exposure to mercury develop a glomerulonephritis characterized by the production of autoantibodies to renal basement membranes. The kinetics of the autoimmune response observed in MAXX rats, as well as the immunohistopathology, histopathology, and proteinuria, are similar to those previously described in BN rats. In addition, the MAXX strain is endowed with excellent fertility. Therefore, both rat strains can be used for comparative studies of the mechanisms of mercury-induced autoimmunity.

Gastric spirillosis in beagles.

Light microscopic, ultrastructural, and microbiologic evaluations were performed on stomachs from 30 healthy laboratory-reared Beagles. Spiral-shaped microorganisms were seen in the gastric glands and parietal cell canaliculi of all the dogs. Organisms were most numerous in the cardia and in the region of the fundic-pyloric junction. Lymphoreticular hyperplasia, dilatation of parietal cell canaliculi, and degeneration of individual parietal cells (rarely seen) were the only morphologic alterations seen. Organisms were helical, had tufts of flagella at each end, and were approximately 0.5 X 7.0 micron; some had a distinct axial fibril (indicating two distinct forms of the organism). Attempts to propagate a viable culture of the organism were not successful. The organism most closely resembled those of the genus Spirillum. Because the organism was commonly found in the gastric mucosa of healthy Beagles, it probably should be considered part of the natural gastric flora of dogs.

Bronchoesophageal fistula and transient megaesophagus in a dog.

Bronchoesophageal fistula and megaesophagus were diagnosed in a dog. Within 2 days after surgical correction of the bronchoesophageal fistula, peristalsis in the thoracic portion of the esophagus returned to normal and the esophagus resumed its normal size. The cause of the fistula was attributed to damage from a foreign body. The cause of the transient megaesophagus likely was related to the bronchoesophageal fistula.