Basic Shock Physiology and Critical Care.

Veterinarians practicing emergency medicine and/or working with exotic animals must be well versed in the pathophysiology of shock because many exotic pets present with an acute crisis or an acute manifestation of a chronic process causing poor organ perfusion. This article discusses the pathophysiology of shock and the systemic inflammatory response syndrome, which may lead to organ dysfunction, organ failure, sepsis, and death. The physiology of perfusion, perfusion measurements, categories of shock, and altered function of the immune system, gastrointestinal barrier, and coagulation system are discussed. Veterinarians providing emergency care to patients with shock must also be aware of comorbidities.

Oral Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor Roxadustat (FG-4592) for the Treatment of Anemia in Patients with CKD.

BACKGROUND AND OBJECTIVES: Roxadustat (FG-4592), an oral hypoxia-inducible factor prolyl hydroxylase inhibitor that stimulates erythropoiesis, regulates iron metabolism, and reduces hepcidin, was evaluated in this phase 2b study for safety, efficacy, optimal dose, and dose frequency in patients with nondialysis CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The 145 patients with nondialysis CKD and hemoglobin ≤10.5 g/dl were randomized into one of six cohorts of approximately 24 patients each with varying roxadustat starting doses (tiered weight and fixed amounts) and frequencies (two and three times weekly) followed by hemoglobin maintenance with roxadustat one to three times weekly. Treatment duration was 16 or 24 weeks. Intravenous iron was prohibited. The primary end point was the proportion of patients achieving hemoglobin increase of ≥1.0 g/dl from baseline and hemoglobin of ≥11.0 g/dl by week 17 (16 weeks of treatment). Secondary analyses included mean hemoglobin change from baseline, iron utilization, and serum lipids. Safety was evaluated by frequency/severity of adverse events. RESULTS: Of the 145 patients enrolled, 143 were evaluable for efficacy. Overall, 92% of patients achieved hemoglobin response. Higher compared with lower starting doses led to earlier achievement of hemoglobin response. Roxadustat-induced hemoglobin increases were independent of baseline C-reactive protein levels and iron repletion status. Overall, over the first 16 treatment weeks, hepcidin levels decreased by 16.9% (P=0.004), reticulocyte hemoglobin content was maintained, and hemoglobin increased by a mean (±SD) of 1.83 (±0.09) g/dl (P<0.001). Overall mean total cholesterol level was reduced by a mean (±SD) of 26 (±30) mg/dl (P<0.001) after 8 weeks of therapy, independent of the use of statins or other lipid-lowering agents. No drug-related serious adverse events were reported. CONCLUSIONS: In patients with nondialysis CKD who were anemic, various starting dose regimens of roxadustat were well tolerated and achieved anemia correction with reduced serum hepcidin levels. After anemia correction, hemoglobin was maintained by roxadustat at various dose frequencies without intravenous iron supplementation.

Dermatologic emergencies: identification and treatment.

Skin disease is one of the most common reasons dogs and cats are taken to the veterinarian. While many dermatologic conditions cause mild, localized signs, some, such as erythema multiforme, toxic epidermal necrolysis, cutaneous vasculitis, cutaneous drug eruptions, and thermal burns, can cause severe cutaneous signs and may have serious systemic consequences. These patients may present on an emergency basis and require intensive monitoring, diagnostics, and care. Lack of familiarity with these conditions may delay diagnosis and appropriate treatment. Pyotraumatic dermatitis may also prompt owners to seek emergency veterinary care due to the severe appearance of associated lesions.

Effects of the PPAR-δ agonist MBX-8025 on atherogenic dyslipidemia.

OBJECTIVE: Determine the effects of treatment with a selective PPAR-δ agonist±statin on plasma lipoprotein subfractions in dyslipidemic individuals. METHODS: Ion mobility analysis was used to measure plasma concentrations of subfractions of the full spectrum of lipoprotein particles in 166 overweight or obese dyslipidemic individuals treated with the PPAR-δ agonist MBX-8025 (50 and 100 mg/d)±atorvastatin (20 mg/d) in an 8-week randomized parallel arm double blind placebo controlled trial. RESULTS: MBX-8025 at both doses resulted in reductions of small plus very small LDL particles and increased levels of large LDL, with a concomitant reduction in large VLDL, and an increase in LDL peak diameter. This translated to reversal of the small dense LDL phenotype (LDL pattern B) in ∼90% of the participants. Modest increases in HDL particles were confined to the smaller HDL fractions. Atorvastatin monotherapy resulted in reductions in particles across the VLDL-IDL-LDL spectrum, with a significantly smaller reduction in small and very small LDL vs. MBX-8025 100 mg/d (-24.5±5.3% vs. -47.8±4.9%), and, in combination with MBX-8025, a reversal of the increase in large LDL. CONCLUSION: PPAR-δ and statin therapies have complementary effects in improving lipoprotein subfractions associated with atherogenic dyslipidemia.

Fanconi syndrome in four non-basenji dogs exposed to chicken jerky treats.

Four small-breed dogs were diagnosed with acquired Fanconi syndrome. All dogs ate varying amounts of chicken jerky treats. All dogs were examined for similar clinical signs that included, but were not limited to, lethargy, vomiting, anorexia, diarrhea, and altered thirst and urination. The quantity of chicken jerky consumed could not be determined; however, based on the histories obtained, the chicken jerky treats were a significant part of the diet and were consumed daily by all dogs. Extensive diagnostic testing eliminated other causes of the observed clinical signs, such as urinary tract infection and rickettsial disease. Glucosuria in the face of euglycemia or hypoglycemia, aminoaciduria, and metabolic acidosis confirmed the diagnosis of Fanconi syndrome. All dogs received supportive care, including IV fluids, antibiotics, gastroprotectants, and oral nutritional supplements. Three dogs exhibited complete resolution of glucosuria, proteinuria, and the associated azotemia; however, one dog remained azotemic, resulting in a diagnosis of chronic kidney disease.

MBX-8025, a novel peroxisome proliferator receptor-delta agonist: lipid and other metabolic effects in dyslipidemic overweight patients treated with and without atorvastatin.

CONTEXT: Preclinical and clinical studies suggest that peroxisome proliferator-activated receptor (PPAR)-δ agonists favorably affect multiple metabolic parameters that are otherwise proatherogenic, many that are not optimally managed with statins alone. OBJECTIVE: The aim of this study was to evaluate the effects of MBX-8025 (a novel PPAR-δ agonist) on lipid and other metabolic parameters associated with increased atherosclerotic risk, administered alone and in combination with atorvastatin. DESIGN AND SETTING: This was a randomized, double-blind, placebo-controlled, parallel group proof-of-concept study conducted at 30 U.S. research sites. PARTICIPANTS: This study evaluated 181 overweight men and women with mixed dyslipidemia. INTERVENTION(S): Subjects were administered once daily placebo, atorvastatin 20 mg, or MBX-8025 at 50 or 100 mg alone or combined with atorvastatin for 8 wk. MAIN OUTCOME MEASURES: The main efficacy measures included change from baseline in apolipoprotein B-100, lipid levels, high-sensitivity C-reactive protein, and additional metabolic parameters, as well as the effect on the metabolic syndrome and LDL particle size. RESULTS: Compared to placebo, MBX-8025 alone and in combination with atorvastatin significantly (P < 0.05) reduced apolipoprotein B-100 20-38%, LDL 18-43%, triglycerides 26-30%, non-high-density lipoprotein cholesterol 18-41%, free fatty acids 16-28%, and high-sensitivity C-reactive protein 43-72%; it raised high-density lipoprotein cholesterol 1-12% and also reduced the number of patients with the metabolic syndrome and a preponderance of small LDL particles. MBX-8025 was safe and generally well-tolerated. MBX-8025 also reduced liver enzyme levels. CONCLUSION: MBX-8025, a novel PPAR-δ agonist, favorably affected multiple metabolic parameters with and without atorvastatin. A more complete understanding of MBX-8025 requires a larger future study.

Assessment of a point-of-care cardiac troponin I test to differentiate cardiac from noncardiac causes of respiratory distress in dogs.

OBJECTIVES: To (1) determine a reference interval for cardiac troponin I (cTnI) using a point-of-care device in normal dogs and compare the results with those published by the manufacturer and (2) determine if cTnI differs among dogs with cardiogenic and noncardiogenic respiratory distress. DESIGN: Prospective observational study. SETTING: Emergency and referral veterinary hospital. ANIMALS: Twenty-six clinically normal dogs and 67 dogs in respiratory distress. INTERVENTIONS: All dogs underwent whole blood sampling for cTnI concentrations. MEASUREMENTS AND RESULTS: Normal dogs had a median cTnI concentration of 0.03 ng/mL (range 0-0.11 ng/mL). Thirty-six dogs were diagnosed with noncardiogenic respiratory distress with a median cTnI concentration of 0.14 ng/mL (range 0.01-4.31 ng/mL). Thirty-one dogs were diagnosed with cardiogenic respiratory distress with a median cTnI concentration of 1.74 ng/mL (range 0.05-17.1 ng/mL). A significant difference between cTnI concentrations in normal dogs and dogs with noncardiogenic respiratory distress was not detected. Significant differences in cTnI concentrations were found between normals versus cardiogenic and cardiogenic versus noncardiogenic respiratory distress groups. Significant differences in cTnI concentrations were identified in > 10 when compared with the < 5 and the 5-10 years of age groups. Receiver operating curve analysis identified cTnI concentrations > 1.5 ng/mL as the optimal "cut-off point" having a sensitivity of 78% and specificity of 51.5%. The area under the receiver operating curve was 0.72. Overall test accuracy was 65%. CONCLUSIONS: cTnI concentrations were significantly increased in dogs with cardiogenic respiratory distress versus dogs with noncardiogenic respiratory distress and normal dogs. A significant difference between normal dogs and dogs with noncardiogenic causes of respiratory distress was detected. Although highly sensitive when cTnI concentrations exceed 1.5 ng/mL, the test has low specificity. Assessment of cTnI by the methodology used cannot be recommended as the sole diagnostic modality for evaluating the cause of respiratory distress in dogs.

Efficacy and safety of CyberKnife radiosurgery for acromegaly.

OBJECTIVE: Acromegaly is a disease characterized by GH hypersecretion, and is typically caused by a pituitary somatotroph adenoma. The primary mode of therapy is surgery, and radiotherapy is utilized as an adjuvant strategy to treat persistent disease. The aim of this study was to determine the efficacy and tolerability of CyberKnife stereotactic radiosurgery in acromegaly. DESIGN: A retrospective review of biochemical and imaging data for subjects with acromegaly treated with CyberKnife stereotactic radiosurgery between 1998 and 2005 at Stanford University Hospital. PATIENTS: Nine patients with active acromegaly were treated with radiosurgery using the CyberKnife (CK). MEASUREMENTS: Biochemical response based on serum insulin-like growth factor-1 (IGF-1), anterior pituitary hormone function, and tumor size with MRI scans were analyzed. RESULTS: After a mean follow up of 25.4 months (range, 6-53 months), CK radiosurgery resulted in complete biochemical remission in 4 (44.4%) subjects, and in biochemical control with the concomitant use of a somatostatin analog in an additional subject. Smaller tumor size was predictive of treatment success: baseline tumor volume was 1.28 cc (+/- 0.81, SD) vs. 3.93 cc (+/- 1.54) in subjects with a normal IGF-1 vs. those with persistent, active disease, respectively (P = 0.02). The mean biologically effective dose (BED) was higher in subjects who achieved a normal IGF-1 vs. those with persistent, active disease, 172 Gy(3) (+/-28) vs. 94 Gy(3) (+/-17), respectively (P < 0.01). At least one new anterior pituitary hormone deficiency was observed after CK in 3 (33%) patients: two developed hypogonadism, and one developed panhypopituitarism. CONCLUSIONS: CK radiosurgery may be a valuable adjuvant therapy for the management of acromegaly.

Isolated Langerhans cell histiocytosis in an adult with central diabetes insipidus: case report and review of literature.

OBJECTIVE: To report a case of ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) in a patient with two distinct neuroendocrine tumors and to highlight the difficulties of establishing the differential diagnosis of EAS. METHODS: We describe the clinical presentation of the current case, discuss its management, and report the results of molecular studies undertaken to determine whether the two tumors had a common origin. RESULTS: A 52-year-old woman presented with obvious features of Cushing's syndrome. Findings on hormonal evaluation were consistent with EAS. Pituitary magnetic resonance imaging revealed normal findings. Computed tomographic imaging disclosed two masses, one in the lung and one in the pancreas. Somatostatin receptor scintigraphy showed uptake only in the pancreatic mass, which was surgically removed. It was a well-differentiated neuroendocrine tumor, with negative immunostaining for ACTH. Hypercortisolemia did not resolve after removal of the pancreatic tumor. The lung mass was subsequently excised, and pathology examination showed a carcinoid tumor with immunostaining for ACTH. Thereafter, plasma ACTH became immeasurable. The two tumors had similar patterns of X-chromosome inactivation; thus, whether they arose independently could be neither confirmed nor excluded. CONCLUSION: This case demonstrates that, in the presence of more than one neuroendocrine tumor, somatostatin receptor scintigraphy may misguide the decision regarding the appropriate surgical course in patients with EAS, and it highlights the need for accurate studies to determine the source of ACTH in patients with EAS.

Molecular and electronic structures by design: tuning symmetrical and unsymmetrical linear trichromium chains.

The preparation, properties, and crystal structures of 12 trichromium extended metal atom chain (EMAC) compounds of the type Cr(3)(L)(4)X(2) (L = equatorial ligands dipyridylamide (dpa) or di-4,4'-ethyl-2,2'-pyridylamide (depa), and X = axial ligands, e.g., halide or pseudohalide ions) with large variations in metal-metal distances are reported here. These complexes, which belong to a broad class of fundamentally interesting trinuclear molecules over which the electrons may or may not be delocalized, pose significant theoretical and experimental challenges which are dealt with in this report. Complexes with strongly donating axial or equatorial ligands tend to favor a symmetrical (D(4)) molecular structure, while more weakly donating ligands give rise to unsymmetrical (C(4)) structures; the physical properties of these two classes of compounds are discussed fully, and important comparisons with a reported DFT model of the electronic structures of the compounds are made.

An efficient synthesis of acetylide/trimetal/acetylide molecular wires.

Efficient syntheses are reported for incorporating trimetal units of the type M(3)(dpa)(4)(2+) (M = Cr, Co, Ni, and dpa = 2,2'-dipyridylamide) into polyalkynyl assemblies to give the prototypical bis-phenylacetylide complexes M(3)(dpa)(4)(CCPh)(2). Reactions of M(3)(dpa)(4)Cl(2) with LiCCPh have led only to mixtures of products which cocrystallize forming materials of the composition M(3)(dpa)(4)(CCPh)(x)()Cl(2)(-)(x)(). Here we report that acetonitrile complexes [M(3)(dpa)(4)(NCCH(3))(2)](PF(6))(2) react cleanly with LiCCPh in MeCN to afford the desired target molecules in 40-60% yield and in excellent purity. Isolation of the mixed ligand complex [Co(3)(dpa)(4)(NCCH(3))(CCPh)]PF(6) has been accomplished, which suggests that these reactions are stepwise and that it will be possible to synthesize mixed acetylide complexes (i.e., M(3)(dpa)(4)(CCR)(CCR')) via this method.