Urinary Catecholamine and Metanephrine to Creatinine Ratios in Dogs with Hyperadrenocorticism or Pheochromocytoma,and in Healthy Dogs

Background: Urinary catecholamines and metanephrines are used for the diagnosis of pheochromocytoma (PHEO) in dogs. Hyperadrenocorticism (HAC) is an important differential diagnosis for PHEO. Objectives: To measure urinary catecholamines and metanephrines in dogs with HAC. Animals: Fourteen dogs with HAC, 7 dogs with PHEO, and 10 healthy dogs. Methods: Prospective clinical trial. Urine was collected during initial work‐up in the hospital; in dogs with HAC an additional sample was taken at home 1 week after discharge. Parameters were measured using high‐pressure liquid chromatography and expressed as ratios to urinary creatinine concentration. Results: Dogs with HAC had significantly higher urinary epinephrine, norepinephrine and normetanephrine to creatinine ratios than healthy dogs. Urinary epinephrine, norepinephrine, and metanephrine to creatinine ratios did not differ between dogs with HAC and dogs with PHEO, whereas the urinary normetanephrine to creatinine ratio was significantly higher (P= .011) in dogs with PHEO (414, 157.0–925.0, median, range versus (117.5, 53.0–323.0). Using a cut‐off ratio of 4 times the highest normetanephrine to creatinine ratio measured in controls, there was no overlap between dogs with HAC and dogs with PHEO. The variables determined in urine samples collected at home did not differ from those collected in the hospital. Conclusion and Clinical Importance: Dogs with HAC might have increased concentrations of urinary catecholamines and normetanephrine. A high concentration of urinary normetanephrine (4 times normal), is highly suggestive of PHEO.     

Urinary catecholamine and metanephrine to creatinine ratios in healthy dogs at home and in a hospital environment and in 2 dogs with pheochromocytoma

BACKGROUND: Measurement of high concentrations of urine catecholamines and metanephrines is useful in diagnosing pheochromocytoma in humans. Stress increases catecholamine excretion in urine. HYPOTHESIS: Stress of a hospital visit increases urinary catecholamine and metanephrine excretion in dogs. ANIMALS: Fourteen clinically normal dogs, 2 dogs with pheochromocytoma. METHODS: Voided urine samples were collected by the owners 7 days before (t-7), during the hospital visit immediately after diagnostic procedures (t0), as well as 1 (t1) and 7 days (t7) after the hospital visit. Urine catecholamine and metanephrine concentrations were measured using high-pressure liquid chromatography and expressed as ratios to urine creatinine concentration. RESULTS: In client-owned dogs epinephrine and norepinephrine ratios at t0 were significantly higher compared with ratios at t7. Metanephrine and normetanephrine ratios at t-7, t0, and t1 did not differ significantly from each other; however, at t7 they were significantly lower compared to values at t-7. In staff-owned dogs no significant differences were detected among the different collecting time points for any variable. Metanephrine and normetanephrine ratios were significantly higher in client-owned dogs compared to staff-owned dogs at t-7, t0, and t1 but not at t7. CONCLUSIONS AND CLINICAL IMPORTANCE: Stress associated with a hospital visit and with the sampling procedure causes increases in urine catecholamine and metanephrine excretion. Urine collection for the diagnosis of pheochromocytoma probably should take place at home after adaptation to the sampling procedure.     

Urinary and Plasma Catecholamines and Metanephrines in Dogs with Pheochromocytoma,Hypercortisolism, Nonadrenal Disease and in Healthy Dogs

Background

Diagnosis of pheochromocytoma (PC) is based on a combination of clinical suspicion, finding an adrenal mass, increased plasma, and urine concentrations of catecholamine metabolites and is finally confirmed with histopathology. In human medicine, it is controversial whether biochemically testing plasma is superior to testing urine.

Objectives

To measure urinary and plasma catecholamines and metanephrines in healthy dogs, dogs with PC, hypercortisolism (HC), and nonadrenal diseases (NAD) and to determine the test with the best diagnostic performance for dogs with PC.

Animals

Seven PC dogs, 10 dogs with HC, 14 dogs with NAD, 10 healthy dogs.

Methods

Prospective diagnostic clinical study. Urine and heparin plasma samples were collected and stored at −80°C before analysis using high‐pressure liquid chromatography (HPLC) coupled to electrochemical detection or tandem mass spectrometry were performed. Urinary variables were expressed as ratios to urinary creatinine concentration.

Results

Dogs with PC had significantly higher urinary normetanephrine and metanephrine : creatinine ratios and significantly higher plasma‐total and free normetanephrine and plasma‐free metanephrine concentrations compared to the 3 other groups. There were no overlapping results of urinary normetanephrine concentrations between PC and all other groups, and only one PC dog with a plasma normetanephrine concentration in the range of the dogs with HC and NAD disease. Performances of total and free plasma variables were similar. Overlap of epinephrine and norepinephrine results between the groups was large with both urine and plasma.

Conclusion and clinical importance

Measurement of normetanephrine is the preferred biochemical test for PC and urine was superior to plasma.     

Serum concentrations of monocyte chemoattractant protein‐1 in healthy and critically ill dogs

Background: The chemokine monocyte chemoattractant protein‐1 (MCP‐1) is a primary regulator of monocyte mobilization from bone marrow, and increased concentrations of MCP‐1 have been associated with sepsis and other inflammatory disorders in critically ill people. The relationship between MCP‐1 and disease in dogs has not been evaluated previously. Objective: The purpose of this study was to assess serum concentrations of MCP‐1 in healthy dogs, dogs in the postoperative period, and critically ill dogs. We hypothesized that MCP‐1 concentrations would be significantly increased in critically ill dogs compared with postoperative or healthy dogs. Methods: Serum concentrations of MCP‐1 were measured in 26 healthy control dogs, 35 postoperative dogs, and 26 critically ill dogs. Critically ill dogs were further subgrouped into dogs with sepsis, parvovirus gastroenteritis, immune‐mediated hemolytic anemia, and severe trauma (n=26). MCP‐1 concentrations were determined using a commercial canine MCP‐1 ELISA. Associations between MCP‐1 concentrations and disease status were evaluated statistically. Results: MCP‐1 concentration was significantly higher in critically ill dogs (median 578 pg/mL, range 144.7–1723 pg/mL) compared with healthy dogs (median 144 pg/mL, range 4.2–266.8 pg/mL) and postoperative dogs (median 160 pg/mL, range 12.6–560.4 pg/mL) (P<.001). All subgroups of critically ill dogs had increased MCP‐1 concentrations with the highest concentrations occurring in dogs with sepsis. However, differences among the 4 subgroups were not statistically significant. Conclusion: Critically ill dogs had markedly increased serum concentrations of MCP‐1 compared with postoperative and healthy dogs. These results indicate that surgery alone is not sufficient to increase MCP‐1 concentrations; thus, measurement of MCP‐1 may be useful in assessing disease severity in critically ill dogs.     

Urinary free metanephrines measurement in dogs with adrenal gland diseases using a new simple liquid chromatography tandem mass spectrometry method

Measurement of urinary metanephrines in spot samples is used for the diagnosis of canine pheochromocytoma (PC). We describe a simple analytical method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) for measuring free metanephrine (MN) and normetanephrine (NMN) in spot urine samples. Using the developed method, we evaluated the stability of urinary free-MN and free-NMN at various storing conditions. In addition, we assessed the feasibility of urinary free-MN and -NMN measurement for diagnosing PC. Urine samples were mixed with stable isotope internal standards and thereafter purified by ultrafiltration. The purified samples were analyzed by LC-MS/MS in the multiple reaction monitoring mode after separation on a multimode octa decyl silyl column. The coefficient of variation of free-MN and -NMN measurement was 7.6% and 5.5%, respectively. The linearity range was 0.5–10 µg/l for both analytes. Degradation was less than 10% for both analytes under any of the storage conditions. The median free-NMN ratio to creatinine of 9 PC dogs (595, range 144–47,961) was significantly higher (P<0.05) than that of 13 dogs with hypercortisolism (125, range 52–224) or 15 healthy dogs (85, range 50–117). The developed method is simple and may not require acidification of spot urine. The results of this preliminary retrospective study suggest that the measurement of urinary free metanephrines is a promising tool for diagnosing canine PC.     

Plasma‐Free Metanephrine and Free Normetanephrine Measurement for the Diagnosis of Pheochromocytoma in Dogs

Background

Measurement of plasma‐free metanephrines is the test of choice to identify pheochromocytoma in human patients.

Objectives

To establish the sensitivity and specificity of plasma‐free metanephrine (fMN) and free normetanephrine (fNMN) concentrations to diagnose pheochromocytoma in dogs.

Animals

Forty‐five client‐owned dogs (8 dogs with pheochromocytoma, 11 dogs with adrenocortical tumors, 15 dogs with nonadrenal disease, and 11 healthy dogs.)

Methods

A prospective study. EDTA plasma was collected from diseased and healthy dogs and submitted for fMN and fNMN measurement by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS).

Results

Free MN concentration (median [range]) was significantly higher in dogs with pheochromocytoma (8.15 [1.73–175.23] nmol/L) than in healthy dogs (0.95 [0.68–3.08] nmol/L; P < .01) and dogs with adrenocortical tumors (0.92 [0.25–2.51] nmol/L; P < .001), but was not different from dogs with nonadrenal disease (1.91 [0.41–6.57] nmol/L; P ≥ .05). Free NMN concentration was significantly higher in dogs with pheochromocytoma (63.89 [10.19–190.31] nmol/L) than in healthy dogs (2.54 [1.59–4.17] nmol/L; P < .001), dogs with nonadrenal disease (3.30 [1.30–10.10] nmol/L; P < .001), and dogs with adrenocortical tumors (2.96 [1.92–5.01] nmol/L); P < 0.01). When used to diagnose pheochromocytoma, a fMN concentration of 4.18 nmol/L had a sensitivity of 62.5% and specificity of 97.3%, and a fNMN concentration of 5.52 nmol/L had a sensitivity of 100% and specificity of 97.6%.

Conclusions and Clinical Importance

Plasma fNMN concentration has excellent sensitivity and specificity for the diagnosis of pheochromocytoma in dogs, whereas fMN concentration has moderate sensitivity and excellent specificity. Measurement of plasma‐free metanephrines provides an effective, noninvasive, means of identifying dogs with pheochromocytoma.     

Stereotactic body radiation therapy as an alternative to adrenalectomy for the treatment of pheochromocytomas in 8 dogs

The objective of this report is to describe the use and outcome of stereotactic body radiation therapy (SBRT) for treatment of pheochromocytomas in 8 dogs. Pheochromocytomas are an uncommon but challenging tumour to manage. Adrenalectomy is the standard of care for treatment of pheochromocytomas in both animals and humans; however, unpredictable catecholamine secretion from the tumour and vascular and local invasion of the tumour and thrombi can pose life-threatening perioperative and anaesthetic risks. SBRT has been investigated as an alternative to adrenalectomy in human patients with pheochromocytomas. Eight dogs with clinical signs, an adrenal mass, and cytology and/or urine normetanephrine/creatinine ratios consistent with pheochromocytoma were treated with SBRT in lieu of adrenalectomy. Three dogs presented with acute hemoabdomen. Seven dogs had caval tumour invasion, 3 with extension into the right atrium. Following SBRT, all dogs had complete resolution of clinical signs and reduced urine normetanephrine/creatinine ratio and/or tumour size. No significant anaesthetic complications were encountered. Acute radiation toxicity was limited to grade I gastrointestinal signs in 3 dogs and resolved within 1–2 days of symptomatic therapy. Five of 8 dogs were alive at the time of follow up, with a median follow up time of 25.8 months. SBRT resulted in a favourable outcome and mitigated the life-threatening risks of adrenalectomy in these 8 dogs. SBRT may be a safe and effective alternative to adrenalectomy for pheochromocytomas in dogs with non-resectable tumours, or for owners averse to the risks of surgery.     

Quantification of normetanephrine in canine urine using ELISA: evaluation of factors affecting results

Catecholamine release increases in dogs with pheochromocytomas and in situations of stress. Although plasma catecholamines degrade rapidly, their metabolites, normetanephrine (NME) and metanephrine (ME), are stable in acidified urine. Our aim was to verify a human urine ELISA kit for the quantification of NME and ME in canine urine and to determine the effects on metabolite stability of sampling time (morning or midday) and day (ordinary or day spent in a clinic). We analyzed 179 urine samples from 17 healthy dogs. For NME, the mean intra-assay CV was 6.0% for all samples and 4.3% for the canine control; inter-assay CVs were 3.3, 3.8, and 12% for high and low concentration human urine positive controls supplied in the ELISA kit and a positive canine control, respectively; spike-recovery was 90–101%. For ME, mean intra-assay CV was 6.5% for samples and 9.0% for the canine control; inter-assay CVs were 12.7, 7.2, and 22.5% for high and low concentration human urine positive controls supplied in the ELISA kit and a positive canine control, respectively; spike-recovery was 85–89%. Dilution recovery was unsatisfactory for both metabolites. Based on our verification results, NME was selected for remaining analyses. We found no effect on NME concentrations of acidification or room temperature storage for up to 24 h. The NME:creatinine ratio was higher after the first of 3 clinic days compared to the same morning (111.2 ± 5.5 vs. 82.9 ± 5.3; p < 0.0001), but not on the other days. NME verification results were generally superior to ME. Dilution studies were unsatisfactory for both metabolites. Given that NME was stable without acidification at room temperature, urine samples can be collected at home. The clinic environment can cause higher NME:creatinine ratios, especially in unaccustomed dogs.     

Nitric Oxide Response in Critically III Dogs

Alterations in nitric oxide (NO)production may play a role in critical illness. Total serum nitrate/nitrite concentrations [SNN (uM/L)], the stable metabolites of NO, have been used as an indirect measure of NO in people, with increased concentrations reported in cases of critical illness. The relationship of nitric oxide (NO) to criticalillness in dgos is unknown. We tested the hypothesis that critically ill intensive care unit (ICU) canine illness in dogs is unknown. We tested the hypothesis that critically ill intesive care unit (ICU) canine patients would have increased SNN as compared to healthy dogs and non-critically ill dogs. An organ failure index score (OFI) was assigned to dogs admitted to the ICU to evaluate trends between disease severtiy and SNN. Critically ill dogs had significantly (p < 0.05) higher SNN (median 10.53) as compared to non-critically ill dogs (median 2.3) and healthy dogs (median 1.92). Critically ill dogs with the most severe disease (as based on OFI) had higher SNN concentrations. Survival of critically ill dogs with SNN of > 15 upon ICU admission (12% survival) was significantly less than survival of critically ill dogs with SNN ≤ 15 (91%) survival).l (Vet. Emerg. & Crit. Care, 9: 195–202, 1999)     

Detection of catecholamines and metanephrines by radio-immunoassay in canine plasma

This study investigated the applicability of two human radio-immunoassays (RIA) to detect epinephrine (EPI), norepinephrine (NE), and their O-methylated metabolites metanephrine (MN) and normetanephrine (NMN) in canine plasma. The analysis yielded a positive correlation between metabolites and their respective parent compounds: EPI and MN (r = 0.63), NE and NMN (r = 0.47), as well as between parent compounds, EPI and NE (r = 0.48), and between metabolites MN and NMN (r = 0.71). Moreover, EPI (r = 0.99) and NE (r = 0.77) concentrations determined by RIA did correlate positively with high pressure liquid chromatography (HPLC). However, there was limited agreement between both methods. It was concluded that complete validation tests for accuracy, precision and agreement are needed before this RIA can be applied to quantify catecholamines, metanephrine, and normetanephrine in canine plasma. The assay may prove to be a potential alternative to HPLC or tandem mass spectrometry in the work-up of pheochromocytoma and the detection of overall sympathetic activity in dogs.     

Relationship among Plasma Amino Acids, C-Reactive Protein, Illness Severity, and Outcome in Critically Ill Dogs

Background: Alterations in circulating amino acids have been documented in animal models and in critically ill people but have not been evaluated in dogs with spontaneously occurring disease.
Hypothesis/Objectives: To compare amino acid concentrations in critically ill dogs and healthy controls and to investigate potential relationships among amino acids, markers of inflammation, illness severity, and clinical outcome.
Animals: Forty-eight critically ill dogs and 24 healthy control dogs.
Methods: Plasma was analyzed for amino acids and C-reactive protein (CRP) was measured in serum. The Fischer ratio (the molar ratio of branched chain amino acids [BCAA] to aromatic amino acids [AAA]) and survival prediction index (SPI2) were calculated.
Results: Median CRP concentrations were significantly higher in the critically ill dogs compared with controls ( P < .001). Critically ill dogs had significantly lower concentrations of alanine ( P = .001), arginine ( P < .001), citrulline ( P < .001), glycine ( P < .001), methionine ( P < .001), proline ( P < .001), and serine ( P = .001) but significantly higher concentrations of lysine ( P = .02) and phenylalanine ( P < .001; Table 1 ). This pattern resulted in a significantly lower Fischer ratio ( P = .001) in the critically ill group. Median SPI2 score was significantly higher in dogs that survived ( P = .03). Concentrations of arginine ( P = .02), isoleucine ( P = .01), leucine ( P = .04), serine ( P = .04), valine ( P = .04), total BCAA ( P = .03), and the Fischer ratio ( P = .03) were significantly higher in survivors compared with nonsurvivors.  

  Table 1.   Comparison between critically ill and healthy control dogs and among different subgroups of diseases within the critically ill group.     

12.

Hypovitaminosis D in dogs with inflammatory bowel disease and hypoalbuminaemia     

Gow AG  Else R  Evans H  Berry JL  Herrtage ME  Mellanby RJ 《The Journal of small animal practice》2011,52(8):411-418

Objectives : To compare serum vitamin D metabolites and plasma parathyroid hormone concentrations in dogs with inflammatory bowel disease and normal albumin concentration, dogs with inflammatory bowel disease and hypoalbuminaemia, healthy dogs and hospitalised ill dogs with non‐gastrointestinal illness. Methods : Serum 25 hydroxyvitamin D and 1,25 dihydroxyvitamin D concentrations were measured in 36 healthy dogs, 49 hospitalised ill dogs with non‐gastrointestinal illnesses, 21 dogs with inflammatory bowel disease and normoalbuminaemia and 12 dogs with inflammatory bowel disease and hypoalbuminaemia. Plasma parathyroid hormone and ionised calcium concentrations were measured in a subset of these dogs. Results : Concentrations of serum 25 hydroxyvitamin D were lower in hypoalbuminaemic dogs with inflammatory bowel disease than in the healthy dogs (P<0·001), hospitalised ill dogs (P<0·001) and normoalbuminaemic dogs with inflammatory bowel disease (P<0·001). Dogs with inflammatory bowel disease and hypoalbuminaemia had a higher plasma concentration of parathyroid hormone (P<0·01) and lower plasma concentration of ionised calcium (P<0·001) than hospitalised ill dogs. Dogs with inflammatory bowel disease had a positive correlation between serum 25 hydroxyvitamin D concentrations and serum albumin (P<0·0001), serum calcium (P<0·0001) and plasma ionised calcium (P<0·0005) concentrations. Clinical Significance : Dogs with inflammatory bowel disease and hypoalbuminaemia frequently have ionised hypocalcaemia, high parathyroid hormone and low serum 25 hydroxyvitamin D concentrations. Further studies are indicated to establish the pathogenesis of this disease complication as well as therapeutic strategies to reverse this state.     

13.

Catecholamine and cortisol responses of horses to incremental exertion     

Jimenez  M.  Hinchcliff  K.W.  Farris  J.W. 《Veterinary research communications》1998,22(2):107-118

The responses of the plasma concentrations of catecholamines and cortisol in horses to varied relative intensities of exertion were examined. The plasma concentrations of cortisol, epinephrine and norepinephrine increased significantly (p<0.05) with exertion. The plasma cortisol concentrations at relative work intensities of 48.3%±1.4%, 82.3%±2.0% and 99.6%±0.4% of VO_2max were 114%, 124%, and 126%, respectively, of those at rest, whereas the plasma epinephrine concentrations were 239%, 772% and 3483%, and the norepinephrine concentrations were 138%, 255%, and 1121% of the values at rest. There was a significant (p<0.0001) relationship between the plasma epinephrine and norepinephrine concentrations. The blood lactate concentration and the plasma epinephrine and norepinephrine concentrations were significantly (p<0.0001) related, as were the relative work intensity (%VO_2max) and the plasma epinephrine and norepinephrine concentrations. The relationships between the plasma cortisol concentration and work intensity or blood lactate concentration were not significant (p>0.05). This study demonstrates a relationship between relative work intensity and indicators of adrenal medullary and sympathetic activity during brief exertion in horses.     

14.

Measurement of plasma chromogranin A concentrations for assessment of stress responses in dogs with insulin-induced hypoglycemia     

Akiyoshi H  Aoki M  Shimada T  Noda K  Kumagai D  Saleh N  Sugii S  Ohashi F 《American journal of veterinary research》2005,66(10):1830-1835

OBJECTIVE: To determine whether cross-reactivity exists between canine chromogranin A (CgA) and anti-human CgA antibody and investigate the usefulness of plasma CgA concentration measurements as an index of acute stress responses in dogs. ANIMALS: 12 healthy Beagles. PROCEDURE: Canine CgA was extracted and purified from canine adrenal glands of cadaver dogs for studying cross-reactivity with anti-human CgA antibody. Western blotting with anti-human CgA antibody was performed. Blood samples were collected from dogs at 0, 10, 20, 30, 40, 60, 120, and 180 minutes after IV administration of saline (0.9% NaCl) solution or insulin. Canine plasma CgA concentrations were determined by use of a CgA ELISA kit with rabbit antiserum against the carboxy-terminal fragment of human CgA. Plasma cortisol and catecholamine (ie, norepinephrine and epinephrine) concentrations were measured by use of an ELISA and a high-performance liquid chromatography method, respectively. RESULTS: Purified canine CgA was specifically detected by use of western blot analysis and an ELISA with anti-human CgA antibody. An increase in plasma CgA concentrations was observed in insulin-induced hypoglycemic dogs. Changes in plasma CgA concentration were correlated with changes in plasma cortisol or catecholamine concentrations of hypoglycemic dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Use of the CgA ELISA kit for determination of human plasma CgA concentrations is applicable to the measurement of canine plasma CgA concentrations. Canine plasma CgA concentrations, along with measurements of plasma cortisol and catecholamine concentrations, correctly reflect insulin-induced hypoglycemic stressed conditions in dogs. Measurement of canine plasma CgA concentrations may provide a useful index for evaluation of an acute stress response.     

15.

Associations among albuminuria, C-reactive protein concentrations, survival predictor index scores, and survival in 78 critically ill dogs     

Whittemore JC  Marcum BA  Mawby DI  Coleman MV  Hacket TB  Lappin MR 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2011,25(4):818-824

Background: Microalbuminuria and C‐reactive protein (CRP) are predictors of morbidity and survival in critically ill human patients. Hypothesis/Objectives: To evaluate results of microalbuminuria assays (untimed single‐sample urine albumin concentration [U‐ALB] and the urine albumin : creatinine ratio [UACR]), serum CRP, and survival predictor index (SPI2) scores as predictors of survival in critically ill dogs. Animals: Seventy‐eight dogs admitted to intensive care units at University of Tennessee (UT) and Colorado State University (CSU). Methods: Prospective observational study. Critically ill dogs were eligible for enrollment, unless euthanized because of financial constraints. Samples were collected within 3 hours of admission. Spearman's rank‐correlation coefficients were determined for U‐ALB, UACR, CRP, and SPI2. U‐ALB, UACR, CRP, and SPI2 were assessed for associations with 7‐ and 30‐day survival by Mann‐Whitney U‐tests and receiver operating characteristic (ROC) curves. P‐values < .0125 were considered significant. Results: UT (n = 49) and CSU (n = 29) patients did not differ significantly. Forty percent (31/78) of dogs died. SPI2 was inversely correlated with U‐ALB (r_s=?0.39, P < .001) and UACR (r_s=?0.41, P < .001). CRP was not correlated with SPI2 (P= .019), U‐ALB (P > .1), or UACR (P > .1). U‐ALB and UACR had very high correlation (r_s= 0.95, P < .001). SPI2, U‐ALB, and UACR differed significantly for survivors and nonsurvivors. SPI2, U‐ALB, and UACR had areas under the ROC curve (AUC) from 0.68 to 0.74 for survival prediction. Conclusions and Clinical Importance: Albuminuria and SPI2, but not CRP, are associated with survival in critically ill dogs. Suboptimal AUCs limit the value of microalbuminuria testing for clinical risk assessment. Additional studies are necessary to determine the usefulness of microalbuminuria testing in patient risk stratification for prospective research.     

16.

Pituitary-adrenal function in dogs with acute critical illness     

Martin LG  Groman RP  Fletcher DJ  Behrend EN  Kemppainen RJ  Moser VR  Hickey KC 《Journal of the American Veterinary Medical Association》2008,233(1):87-95

OBJECTIVE: To evaluate pituitary-adrenal function in critically ill dogs with sepsis, severe trauma, and gastric dilatation-volvulus (GDV). DESIGN: Cohort study. ANIMALS: 31 ill dogs admitted to an intensive care unit (ICU) at Washington State University or the University of Pennsylvania; all dogs had acute critical illness for < 48 hours prior to admission. PROCEDURES: Baseline and ACTH-stimulated serum cortisol concentrations and baseline plasma ACTH concentrations were assayed for each dog within 24 hours after admission to the ICU. The change in cortisol concentrations (Delta-cortisol) was calculated for each dog. Morbidity and mortality data were recorded for each patient. RESULTS: Overall, 17 of 31 (55%) acutely critically ill dogs had at least 1 biochemical abnormality suggestive of adrenal gland or pituitary gland insufficiency. Only 1 (3%) dog had an exaggerated response to ACTH stimulation. Dogs with Delta-cortisol < or = 83 nmol/L were 5.7 times as likely to be receiving vasopressors as were dogs with Delta-cortisol > 83 nmol/L. No differences were detected among dogs with sepsis, severe trauma, or GDV with respect to mean baseline and ACTH-stimulated serum cortisol concentrations, Delta-cortisol, and baseline plasma ACTH concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Biochemical abnormalities of the hypothalamic-pituitary-adrenal axis indicative of adrenal gland or pituitary gland insufficiency were common in critically ill dogs, whereas exaggerated responses to ACTH administration were uncommon. Acutely ill dogs with Delta-cortisol < or = 83 nmol/L may be more likely to require vasopressors as part of the treatment plan.     

17.

The association between vascular endothelial growth factor levels and clinically evident peripheral edema in dogs with systemic inflammatory response syndrome     

Deborah C. Silverstein  DVM  DACVECC  ; Catalina Montealegre  VMD  ; Frances S. Shofer  PhD    Cynthia M. Otto  DVM  PhD  DACVECC 《Journal of Veterinary Emergency and Critical Care》2009,19(5):459-466

     

18.

Effect of N‐Acetylcysteine Supplementation on Intracellular Glutathione,Urine Isoprostanes,Clinical Score,and Survival in Hospitalized Ill Dogs     

K.R. Viviano  B. VanderWielen 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2013,27(2):250-258

Background

Antioxidant depletion and lipid peroxidation have been correlated with disease severity and associated with poor outcomes.

Hypothesis/Objectives

Supplementing dogs with N‐acetylcysteine (NAC) during the first 48 hours of hospitalization will increase cysteine, normalize glutathione concentrations, and decrease the degree of lipid peroxidation associated with illness.

Animals

Sixty systemically ill hospitalized client‐owned dogs and 14 healthy control dogs.

Methods

Randomized investigator‐blinded, placebo‐controlled prospective study. Dogs were randomized to treatment with NAC (n = 30) versus placebo (n = 30). Antioxidants, urine 8‐isoprostane/creatinine (IP/Cr), and clinical score were determined before and after treatment with NAC. Glutathione, cysteine, and vitamin E concentrations were quantified using high‐performance liquid chromatography. Atomic absorption spectroscopy and enzyme‐linked immunosorbent assays were used to quantify selenium and isoprostane concentrations, respectively.

Results

Ill dogs had significantly lower vitamin E concentrations (27 versus 55 μg/mL; P = .0005) as well as elevated IP/Cr ratios (872 versus 399 pg/mg; P = .0007) versus healthy dogs. NAC supplementation significantly increased plasma cysteine (8.67 versus 15.1 μM; P < .0001) while maintaining glutathione concentrations. Dogs in the placebo group experienced a statistically significant decrease in glutathione concentrations (1.49 versus 1.44 mM; P = .0463). Illness severity and survival were unchanged after short duration NAC supplementation.

Conclusions

Ill dogs experience systemic oxidative stress. Supplementation with NAC during the first 48 hours of hospitalization stabilized erythrocyte glutathione concentrations. The clinical impact of this supplementation and glutathione concentration stabilization was undetermined.     

19.

Measurement of urinary 11-dehydro-thromboxane B2 excretion in dogs with gastric dilatation-volvulus     

Baltzer WI  McMichael MA  Ruaux CG  Noaker L  Steiner JM  Williams DA 《American journal of veterinary research》2006,67(1):78-83

OBJECTIVE: To measure 11-dehydro-thromboxane B2 (11-dTXB2) in urine of healthy control dogs, dogs undergoing ovariohysterectomy, and dogs with gastric dilatation-volvulus (GDV) and assess the relationship between urinary 11-dTXB2 concentrations in dogs with GDV and postoperative outcomes. SAMPLE POPULATION: Urine samples from 15 nonsurgical control dogs, 12 surgical control dogs, and 32 dogs with GVD. PROCEDURE: Urine samples were obtained from healthy pet dogs (ie, nonsurgical control dogs), dogs undergoing ovariohysterectomy at anesthetic induction and 1 hour following surgery (ie, surgical control dogs), and dogs with GDV at hospital admission and 1 hour following surgical derotation of the stomach (ie, GDV dogs). Urinary 11-dTXB2 concentrations were determined with an ELISA and normalized to urinary creatinine (Cr) concentrations by calculation of the 11-dTXB2 -to-Cr ratio. Differences in median 11-dTXB2 -to-Cr ratios among dogs and before and after surgery were analyzed. RESULTS: Urinary 11-dTXB2-to-Cr ratios did not differ between nonsurgical control dogs and surgical control dogs before or after surgery. Urinary 11-dTXB2-to-Cr ratios were significantly higher in GDV dogs at the time of hospital admission and 1 hour after surgery, compared with those of nonsurgical control dogs. Postoperative urine samples from GDV dogs had significantly higher 11-dTXB2-to-Cr ratios than postoperative urine samples from surgical control dogs. Median urinary 11-dTXB2-to-Cr ratios increased significantly in GDV dogs that developed postoperative complications. CONCLUSIONS AND CLINICAL RELEVANCE: Urinary 11-dTXB2 concentration is increased in GDV dogs at the time of hospital admission and after surgical derotation of the stomach, compared with that of healthy dogs. An increased urinary 11-dTXB2-to-Cr ratio following surgery is associated with an increased incidence of postoperative complications in dogs with GDV.     

20.

Glutathione, Cysteine, and Ascorbate Concentrations in Clinically Ill Dogs and Cats     

K.R. Viviano  S.N. Lavergne  L. Goodman  B. VanderWielen  L. Grundahl  M. Padilla  L.A. Trepanier 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(2):250-257

Background: Oxidative stress plays a role in the pathogenesis of many systemic diseases. Hospitalized human patients are glutathione, cysteine, and ascorbate deficient, and antioxidant depletion has been correlated with poor clinical outcome. To date little is known about antioxidant concentrations in hospitalized veterinary patients. The purpose of this study was to determine whether ascorbate, cysteine, or glutathione depletion is present in ill dogs and cats compared with healthy controls.
Hypothesis: Clinically ill dogs and cats would be antioxidant depleted, and depletion would correlate with illness severity and clinical outcome.
Animals: Clinically ill client-owned dogs (n = 61) and cats (n = 37), healthy control dogs (n = 37) and cats (n = 33).
Methods: Prospective, observational, case control study. Erythrocyte reduced glutathione, plasma cysteine, and plasma ascorbate were quantified using high-performance liquid chromatography.
Results: Clinically ill dogs had significantly lower erythrocyte glutathione concentrations (1.22 mM, range 0.55–3.61) compared with controls (1.91 mM, range 0.87–3.51; P = .0004), and glutathione depletion correlated with both illness severity ( P = .038) and mortality ( P = .010). Cats had higher ascorbate concentrations when ill (10.65 μM, range 1.13–25.26) compared with controls (3.68 μM, range 0.36–13.57; P = .0009).
Conclusions and Clinical Importance: Clinically ill dogs had decreased erythrocyte glutathione concentrations, which could be a marker of illness severity and prognostic of a poor outcome. Clinically ill cats had an unexpectedly high plasma ascorbate, which could represent a unique species response to oxidative stress.     

Hypovitaminosis D in dogs with inflammatory bowel disease and hypoalbuminaemia

Objectives : To compare serum vitamin D metabolites and plasma parathyroid hormone concentrations in dogs with inflammatory bowel disease and normal albumin concentration, dogs with inflammatory bowel disease and hypoalbuminaemia, healthy dogs and hospitalised ill dogs with non‐gastrointestinal illness. Methods : Serum 25 hydroxyvitamin D and 1,25 dihydroxyvitamin D concentrations were measured in 36 healthy dogs, 49 hospitalised ill dogs with non‐gastrointestinal illnesses, 21 dogs with inflammatory bowel disease and normoalbuminaemia and 12 dogs with inflammatory bowel disease and hypoalbuminaemia. Plasma parathyroid hormone and ionised calcium concentrations were measured in a subset of these dogs. Results : Concentrations of serum 25 hydroxyvitamin D were lower in hypoalbuminaemic dogs with inflammatory bowel disease than in the healthy dogs (P<0·001), hospitalised ill dogs (P<0·001) and normoalbuminaemic dogs with inflammatory bowel disease (P<0·001). Dogs with inflammatory bowel disease and hypoalbuminaemia had a higher plasma concentration of parathyroid hormone (P<0·01) and lower plasma concentration of ionised calcium (P<0·001) than hospitalised ill dogs. Dogs with inflammatory bowel disease had a positive correlation between serum 25 hydroxyvitamin D concentrations and serum albumin (P<0·0001), serum calcium (P<0·0001) and plasma ionised calcium (P<0·0005) concentrations. Clinical Significance : Dogs with inflammatory bowel disease and hypoalbuminaemia frequently have ionised hypocalcaemia, high parathyroid hormone and low serum 25 hydroxyvitamin D concentrations. Further studies are indicated to establish the pathogenesis of this disease complication as well as therapeutic strategies to reverse this state.     

Catecholamine and cortisol responses of horses to incremental exertion

The responses of the plasma concentrations of catecholamines and cortisol in horses to varied relative intensities of exertion were examined. The plasma concentrations of cortisol, epinephrine and norepinephrine increased significantly (p<0.05) with exertion. The plasma cortisol concentrations at relative work intensities of 48.3%±1.4%, 82.3%±2.0% and 99.6%±0.4% of VO_2max were 114%, 124%, and 126%, respectively, of those at rest, whereas the plasma epinephrine concentrations were 239%, 772% and 3483%, and the norepinephrine concentrations were 138%, 255%, and 1121% of the values at rest. There was a significant (p<0.0001) relationship between the plasma epinephrine and norepinephrine concentrations. The blood lactate concentration and the plasma epinephrine and norepinephrine concentrations were significantly (p<0.0001) related, as were the relative work intensity (%VO_2max) and the plasma epinephrine and norepinephrine concentrations. The relationships between the plasma cortisol concentration and work intensity or blood lactate concentration were not significant (p>0.05). This study demonstrates a relationship between relative work intensity and indicators of adrenal medullary and sympathetic activity during brief exertion in horses.     

Measurement of plasma chromogranin A concentrations for assessment of stress responses in dogs with insulin-induced hypoglycemia

OBJECTIVE: To determine whether cross-reactivity exists between canine chromogranin A (CgA) and anti-human CgA antibody and investigate the usefulness of plasma CgA concentration measurements as an index of acute stress responses in dogs. ANIMALS: 12 healthy Beagles. PROCEDURE: Canine CgA was extracted and purified from canine adrenal glands of cadaver dogs for studying cross-reactivity with anti-human CgA antibody. Western blotting with anti-human CgA antibody was performed. Blood samples were collected from dogs at 0, 10, 20, 30, 40, 60, 120, and 180 minutes after IV administration of saline (0.9% NaCl) solution or insulin. Canine plasma CgA concentrations were determined by use of a CgA ELISA kit with rabbit antiserum against the carboxy-terminal fragment of human CgA. Plasma cortisol and catecholamine (ie, norepinephrine and epinephrine) concentrations were measured by use of an ELISA and a high-performance liquid chromatography method, respectively. RESULTS: Purified canine CgA was specifically detected by use of western blot analysis and an ELISA with anti-human CgA antibody. An increase in plasma CgA concentrations was observed in insulin-induced hypoglycemic dogs. Changes in plasma CgA concentration were correlated with changes in plasma cortisol or catecholamine concentrations of hypoglycemic dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Use of the CgA ELISA kit for determination of human plasma CgA concentrations is applicable to the measurement of canine plasma CgA concentrations. Canine plasma CgA concentrations, along with measurements of plasma cortisol and catecholamine concentrations, correctly reflect insulin-induced hypoglycemic stressed conditions in dogs. Measurement of canine plasma CgA concentrations may provide a useful index for evaluation of an acute stress response.     

Associations among albuminuria, C-reactive protein concentrations, survival predictor index scores, and survival in 78 critically ill dogs

Background: Microalbuminuria and C‐reactive protein (CRP) are predictors of morbidity and survival in critically ill human patients. Hypothesis/Objectives: To evaluate results of microalbuminuria assays (untimed single‐sample urine albumin concentration [U‐ALB] and the urine albumin : creatinine ratio [UACR]), serum CRP, and survival predictor index (SPI2) scores as predictors of survival in critically ill dogs. Animals: Seventy‐eight dogs admitted to intensive care units at University of Tennessee (UT) and Colorado State University (CSU). Methods: Prospective observational study. Critically ill dogs were eligible for enrollment, unless euthanized because of financial constraints. Samples were collected within 3 hours of admission. Spearman's rank‐correlation coefficients were determined for U‐ALB, UACR, CRP, and SPI2. U‐ALB, UACR, CRP, and SPI2 were assessed for associations with 7‐ and 30‐day survival by Mann‐Whitney U‐tests and receiver operating characteristic (ROC) curves. P‐values < .0125 were considered significant. Results: UT (n = 49) and CSU (n = 29) patients did not differ significantly. Forty percent (31/78) of dogs died. SPI2 was inversely correlated with U‐ALB (r_s=?0.39, P < .001) and UACR (r_s=?0.41, P < .001). CRP was not correlated with SPI2 (P= .019), U‐ALB (P > .1), or UACR (P > .1). U‐ALB and UACR had very high correlation (r_s= 0.95, P < .001). SPI2, U‐ALB, and UACR differed significantly for survivors and nonsurvivors. SPI2, U‐ALB, and UACR had areas under the ROC curve (AUC) from 0.68 to 0.74 for survival prediction. Conclusions and Clinical Importance: Albuminuria and SPI2, but not CRP, are associated with survival in critically ill dogs. Suboptimal AUCs limit the value of microalbuminuria testing for clinical risk assessment. Additional studies are necessary to determine the usefulness of microalbuminuria testing in patient risk stratification for prospective research.     

Pituitary-adrenal function in dogs with acute critical illness

OBJECTIVE: To evaluate pituitary-adrenal function in critically ill dogs with sepsis, severe trauma, and gastric dilatation-volvulus (GDV). DESIGN: Cohort study. ANIMALS: 31 ill dogs admitted to an intensive care unit (ICU) at Washington State University or the University of Pennsylvania; all dogs had acute critical illness for < 48 hours prior to admission. PROCEDURES: Baseline and ACTH-stimulated serum cortisol concentrations and baseline plasma ACTH concentrations were assayed for each dog within 24 hours after admission to the ICU. The change in cortisol concentrations (Delta-cortisol) was calculated for each dog. Morbidity and mortality data were recorded for each patient. RESULTS: Overall, 17 of 31 (55%) acutely critically ill dogs had at least 1 biochemical abnormality suggestive of adrenal gland or pituitary gland insufficiency. Only 1 (3%) dog had an exaggerated response to ACTH stimulation. Dogs with Delta-cortisol < or = 83 nmol/L were 5.7 times as likely to be receiving vasopressors as were dogs with Delta-cortisol > 83 nmol/L. No differences were detected among dogs with sepsis, severe trauma, or GDV with respect to mean baseline and ACTH-stimulated serum cortisol concentrations, Delta-cortisol, and baseline plasma ACTH concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Biochemical abnormalities of the hypothalamic-pituitary-adrenal axis indicative of adrenal gland or pituitary gland insufficiency were common in critically ill dogs, whereas exaggerated responses to ACTH administration were uncommon. Acutely ill dogs with Delta-cortisol < or = 83 nmol/L may be more likely to require vasopressors as part of the treatment plan.     

Effect of N‐Acetylcysteine Supplementation on Intracellular Glutathione,Urine Isoprostanes,Clinical Score,and Survival in Hospitalized Ill Dogs

Background

Antioxidant depletion and lipid peroxidation have been correlated with disease severity and associated with poor outcomes.

Hypothesis/Objectives

Supplementing dogs with N‐acetylcysteine (NAC) during the first 48 hours of hospitalization will increase cysteine, normalize glutathione concentrations, and decrease the degree of lipid peroxidation associated with illness.

Animals

Sixty systemically ill hospitalized client‐owned dogs and 14 healthy control dogs.

Methods

Randomized investigator‐blinded, placebo‐controlled prospective study. Dogs were randomized to treatment with NAC (n = 30) versus placebo (n = 30). Antioxidants, urine 8‐isoprostane/creatinine (IP/Cr), and clinical score were determined before and after treatment with NAC. Glutathione, cysteine, and vitamin E concentrations were quantified using high‐performance liquid chromatography. Atomic absorption spectroscopy and enzyme‐linked immunosorbent assays were used to quantify selenium and isoprostane concentrations, respectively.

Results

Ill dogs had significantly lower vitamin E concentrations (27 versus 55 μg/mL; P = .0005) as well as elevated IP/Cr ratios (872 versus 399 pg/mg; P = .0007) versus healthy dogs. NAC supplementation significantly increased plasma cysteine (8.67 versus 15.1 μM; P < .0001) while maintaining glutathione concentrations. Dogs in the placebo group experienced a statistically significant decrease in glutathione concentrations (1.49 versus 1.44 mM; P = .0463). Illness severity and survival were unchanged after short duration NAC supplementation.

Conclusions

Ill dogs experience systemic oxidative stress. Supplementation with NAC during the first 48 hours of hospitalization stabilized erythrocyte glutathione concentrations. The clinical impact of this supplementation and glutathione concentration stabilization was undetermined.     

Measurement of urinary 11-dehydro-thromboxane B2 excretion in dogs with gastric dilatation-volvulus

OBJECTIVE: To measure 11-dehydro-thromboxane B2 (11-dTXB2) in urine of healthy control dogs, dogs undergoing ovariohysterectomy, and dogs with gastric dilatation-volvulus (GDV) and assess the relationship between urinary 11-dTXB2 concentrations in dogs with GDV and postoperative outcomes. SAMPLE POPULATION: Urine samples from 15 nonsurgical control dogs, 12 surgical control dogs, and 32 dogs with GVD. PROCEDURE: Urine samples were obtained from healthy pet dogs (ie, nonsurgical control dogs), dogs undergoing ovariohysterectomy at anesthetic induction and 1 hour following surgery (ie, surgical control dogs), and dogs with GDV at hospital admission and 1 hour following surgical derotation of the stomach (ie, GDV dogs). Urinary 11-dTXB2 concentrations were determined with an ELISA and normalized to urinary creatinine (Cr) concentrations by calculation of the 11-dTXB2 -to-Cr ratio. Differences in median 11-dTXB2 -to-Cr ratios among dogs and before and after surgery were analyzed. RESULTS: Urinary 11-dTXB2-to-Cr ratios did not differ between nonsurgical control dogs and surgical control dogs before or after surgery. Urinary 11-dTXB2-to-Cr ratios were significantly higher in GDV dogs at the time of hospital admission and 1 hour after surgery, compared with those of nonsurgical control dogs. Postoperative urine samples from GDV dogs had significantly higher 11-dTXB2-to-Cr ratios than postoperative urine samples from surgical control dogs. Median urinary 11-dTXB2-to-Cr ratios increased significantly in GDV dogs that developed postoperative complications. CONCLUSIONS AND CLINICAL RELEVANCE: Urinary 11-dTXB2 concentration is increased in GDV dogs at the time of hospital admission and after surgical derotation of the stomach, compared with that of healthy dogs. An increased urinary 11-dTXB2-to-Cr ratio following surgery is associated with an increased incidence of postoperative complications in dogs with GDV.     

Glutathione, Cysteine, and Ascorbate Concentrations in Clinically Ill Dogs and Cats

Background: Oxidative stress plays a role in the pathogenesis of many systemic diseases. Hospitalized human patients are glutathione, cysteine, and ascorbate deficient, and antioxidant depletion has been correlated with poor clinical outcome. To date little is known about antioxidant concentrations in hospitalized veterinary patients. The purpose of this study was to determine whether ascorbate, cysteine, or glutathione depletion is present in ill dogs and cats compared with healthy controls.
Hypothesis: Clinically ill dogs and cats would be antioxidant depleted, and depletion would correlate with illness severity and clinical outcome.
Animals: Clinically ill client-owned dogs (n = 61) and cats (n = 37), healthy control dogs (n = 37) and cats (n = 33).
Methods: Prospective, observational, case control study. Erythrocyte reduced glutathione, plasma cysteine, and plasma ascorbate were quantified using high-performance liquid chromatography.
Results: Clinically ill dogs had significantly lower erythrocyte glutathione concentrations (1.22 mM, range 0.55–3.61) compared with controls (1.91 mM, range 0.87–3.51; P = .0004), and glutathione depletion correlated with both illness severity ( P = .038) and mortality ( P = .010). Cats had higher ascorbate concentrations when ill (10.65 μM, range 1.13–25.26) compared with controls (3.68 μM, range 0.36–13.57; P = .0009).
Conclusions and Clinical Importance: Clinically ill dogs had decreased erythrocyte glutathione concentrations, which could be a marker of illness severity and prognostic of a poor outcome. Clinically ill cats had an unexpectedly high plasma ascorbate, which could represent a unique species response to oxidative stress.