Carla S. Sommardahl Copyright (c) 2012 All rights reserved. http://works.bepress.com/carla_sommardahl Recent documents in Carla S. Sommardahl en-us Fri, 23 Nov 2012 08:10:22 PST 3600 A Novel Polygenic Mouse Model of Obesity and Diabetes: Evaluation of Genetic and Nutritional Control on Obesity and Glucose Homeostasis http://works.bepress.com/carla_sommardahl/23 http://works.bepress.com/carla_sommardahl/23 Fri, 23 Dec 2011 14:24:52 PST Madhu S. Dhar et al. A novel mouse model for obesity, type 2 diabetes, and nonalcoholic fatty liver disease http://works.bepress.com/carla_sommardahl/22 http://works.bepress.com/carla_sommardahl/22 Fri, 23 Dec 2011 14:08:28 PST Madhu S. Dhar et al. Mice heterozygous for Atp10c, a putative amphipath, represent a novel model of obesity and type 2 diabetes http://works.bepress.com/carla_sommardahl/20 http://works.bepress.com/carla_sommardahl/20 Sun, 02 Oct 2011 13:12:33 PDT Atp10c is a novel type IV P-type ATPase and is a putative phospholipid transporter. The purpose of this study was to assess the overall effect of the heterozygous deletion of Atp10c on obesity-related phenotypes and metabolic abnormalities in mice fed a high-fat diet. Heterozygous mice with maternal inheritance of Atp10c were compared with heterozygous mice with paternal inheritance of Atp10c and wild-type controls. Body weight, adiposity index, and plasma insulin, leptin and triglyceride concentrations were significantly greater in the mutants inheriting the deletion maternally compared with their sex- and age-matched control male mice fed a 10% fat (% energy) diet and female mice fed a 45% fat (% energy) diet. Glucose and insulin tolerance tests were performed after mice consumed the diets for 4 and 8 wk. Mutants had altered glucose tolerance and insulin response compared with controls, suggesting insulin resistance in both sexes. Mice were killed at 12 wk and routine gross and histological evaluations of the liver, pancreas, adipose tissue, and heart were performed. Histological evaluation showed micro- and macrovesicular lipid deposition within the hepatocytes that was more severe in the mutant mice than in age-matched controls. Although sex differences were observed, our data suggest that heterozygous deletion along with an unusual pattern of maternal inheritance of the chromosomal region containing the single gene, Atp10c, causes obesity, type 2 diabetes, and nonalcoholic fatty liver disease in these mice.

]]> Madhu Dhar et al. Effects of oral administration of levothyroxine sodium on serum concentrations of thyroid gland hormones and responses to injections of thyrotropin-releasing hormone in healthy adult mares http://works.bepress.com/carla_sommardahl/19 http://works.bepress.com/carla_sommardahl/19 Sun, 02 Oct 2011 13:02:21 PDT OBJECTIVE: To determine the effects of levothyroxine sodium (L-T4) on serum concentrations of thyroid gland hormones and responses to injections of thyrotropin-releasing hormone (TRH) in euthyroid horses. ANIMALS: 12 healthy adult mares. PROCEDURE: 8 horses received an incrementally increasing dosage of L-T4 (24, 48, 72, or 96 mg of L-T4/d) for weeks 1 to 8. Each dose was provided for 2 weeks. Four additional horses remained untreated. Serum concentrations of total triiodothyronine (tT3), total thyroxine (tT4), free T3 (fT3), free T4 (fT4), and thyroid-stimulating hormone (TSH) were measured in samples obtained at weeks 0, 2, 4, 6, and 8; 1.2 mg of TRH was then administered i.v., and serum concentrations of thyroid gland hormones were measured 2 and 4 hours after injection. Serum reverseT3 (rT3) concentration was also measured in the samples collected at weeks 0 and 8. RESULTS: Treated horses lost a significant amount of weight (median, 19 kg). Significant treatment-by-time effects were detected for serum tT3, tT4, fT3, fT4, and TSH concentrations, and serum tT4 concentrations were positively correlated (r, 0.95) with time (and therefore dosage) in treated horses. Mean +/- SD serum rT3 concentration significantly increased in treated horses (3.06 +/- 0.51 nmol/L for week 8 vs 0.74 +/- 0.22 nmol/L for week 0). Serum tT3, tT4, fT3, and TSH concentrations in response to TRH injections differed significantly between treated and untreated horses. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of levothyroxine sodium increased serum tT4 concentrations and blunted responses toTRH injection in healthy euthyroid horses.

]]> Carla S. Sommardahl et al. Effects of oral administration of levothyroxine sodium on concentrations of plasma lipids, concentration and composition of very-low-density lipoproteins, and glucose dynamics in healthy adult mares http://works.bepress.com/carla_sommardahl/18 http://works.bepress.com/carla_sommardahl/18 Sun, 02 Oct 2011 12:59:22 PDT OBJECTIVE: To evaluate glucose and lipid metabolism in healthy adult horses administered levothyroxine sodium (L-T4). ANIMALS: 12 healthy adult mares. PROCEDURE: 8 horses received an incrementally increasing dosage of L-T4 (24, 48, 72, or 96 mg of L-T4/d) for weeks 1 to 8. Each dose was provide between 7 AM and 8 AM in the morning grain meal for 2 weeks. Four additional horses remained untreated. Serum concentrations of nonesterified fatty acids, triglyceride (TG), total cholesterol (TC), and very-low-density lipoprotein (VLDL) were measured and composition of VLDL examined in samples obtained between 8 AM and 9 AM at weeks 0, 2, 4, 6, and 8. Glucose dynamics were assessed by use of a combined IV glucose-insulin tolerance test (IVGITT) conducted before and at the end of the 8-week treatment period. Data for each combined IVGITT were interpreted by use of the minimal model. RESULTS: Plasma TG, TC, and VLDL concentrations significantly decreased over time in treated horses. At the completion of the 8-week treatment period, mean plasma VLDL concentration was 46% of the mean value for week 0 in treated horses. Insulin sensitivity significantly increased (> 2-fold) in treated horses, but glucose effectiveness and net insulin response were not affected. Levothyroxine sodium significantly increased the rate of insulin disposal. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of L-T4 decreases blood lipid concentrations, improves insulin sensitivity, and increases insulin disposal in horses. Levothyroxine sodium may have potential as a treatment for horses with reduced insulin sensitivity.

]]> Nicholas Frank et al. Effect of a 24-hour infusion of an isotonic electrolyte replacement fluid on the renal clearance of electrolytes in healthy neonatal foals http://works.bepress.com/carla_sommardahl/17 http://works.bepress.com/carla_sommardahl/17 Sun, 02 Oct 2011 12:55:59 PDT OBJECTIVE: To determine the effects of a 24-hour infusion of an isotonic electrolyte replacement fluid (IERF) on weight, serum and urine electrolyte concentrations, and other clinicopathologic variables in healthy neonatal foals. ANIMALS: 4 healthy 4-day-old foals. DESIGN: Prospective study. PROCEDURE: An IERF was administered to each foal at an estimated rate of 80 mL/kg/d (36.4 mL/lb/d) for 24 hours. Body weight was measured before and after the infusion period. Urine was collected via catheter during 4-hour periods; blood samples were collected at 4-hour intervals. Variables including urine production; urine and serum osmolalities; sodium, potassium, and chloride concentrations in urine and serum; urine and serum creatinine concentrations; urine osmolality-to-serum osmolality ratio (OsmR); transtubular potassium gradient (TTKG); and percentage creatinine clearance (Cr(cl)) of electrolytes were recorded at 0, 4, 8, 12, 16, 20, and 24 hours during the infusion period. Immediately after the study period, net fluid and whole-body electrolyte changes from baseline values were calculated. RESULTS: Compared with baseline values, urine and serum sodium and chloride serum concentrations, urine and serum osmolalities, OsmR, and percentage Cr(cl) of sodium and chloride were significantly increased at various time points during the infusion; urine production did not change significantly. After 24 hours, weight, TTKG, serum creatinine concentration, and whole-body potassium had significantly decreased from baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of an IERF containing a physiologic concentration of sodium may not be appropriate for use in neonatal foals that require maintenance fluid therapy.

]]> B R. Buchanan et al. What is your diagnosis? Pyloric-duodenal intussusception http://works.bepress.com/carla_sommardahl/16 http://works.bepress.com/carla_sommardahl/16 Sun, 02 Oct 2011 12:52:33 PDT B R. Buchanan et al. Evaluation of the combined dexamethasone suppression/ thyrotropin-releasing hormone stimulation test for detection of pars intermedia pituitary adenomas in horses http://works.bepress.com/carla_sommardahl/15 http://works.bepress.com/carla_sommardahl/15 Sun, 02 Oct 2011 12:49:13 PDT BACKGROUND: A combined dexamethasone (DEX) suppression/thyrotropin-releasing hormone (TRH) test (DEX/TRH test) has been developed to evaluate horses for presence of a pars intermedia pituitary adenoma (PIPA), but to the authors' knowledge, the accuracy of this test has not been previously determined. HYPOTHESIS: The sensitivity and specificity of the DEX/TRH test can be determined by comparing test results with histopathologic examination findings. ANIMALS: Age of 42 horses of various breeds ranged from 2 to 33 years. METHODS: Plasma cortisol concentration was measured before and 24 hours after IV administration of 40 microg of DEX/kg of body weight, and before and 30 minutes after IV administration of 1 mg of TRH that had been given 3 hours after the injection of DEX. Results of the DEX/TRH test were considered positive if either the plasma cortisol concentration exceeded 10 ng/mL 24 hours after DEX administration, or if the change in plasma cortisol concentration 30 minutes after injection of TRH was > or = 66% above the 3-hour baseline. Diagnosis of PIPA was determined by histologic examination of the pituitary gland. RESULTS: PIPA was detected in 17 of 42 (40%) horses. The DEX/TRH test had sensitivity, specificity, positive predictive value, and negative (NPV) predictive value of 88, 76, 71, and 90%, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: The combined DEX/TRH test was more sensitive than either of its component tests and had a high NPV, but was not as specific as the TRH component alone (92%). The DEX/TRH test should be used to screen older horses for PIPA.

]]> Nicholas Frank et al. A type IV P-type ATPase affects insulin-mediated glucose uptake in adipose tissue and skeletal muscle in mice http://works.bepress.com/carla_sommardahl/14 http://works.bepress.com/carla_sommardahl/14 Sun, 02 Oct 2011 12:46:19 PDT Mice carrying two pink-eyed dilution (p) locus heterozygous deletions represent a novel polygenic mouse model of type 2 diabetes associated with obesity. Atp10c, a putative aminophospholipid transporter on mouse chromosome 7, is a candidate for the phenotype. The phenotype is diet-induced. As a next logical step in the validation and characterization of the model, experiments to analyze metabolic abnormalities associated with these mice were carried out. Results demonstrate that mutants (inheriting the p deletion maternally) heterozygous for Atp10c are hyperinsulinemic, insulin-resistant and have an altered insulin-stimulated response in peripheral tissues. Adipose tissue and the skeletal muscle are the targets, and GLUT4-mediated glucose uptake is the specific metabolic pathway associated with Atp10c deletion. Insulin resistance primarily affects the adipose tissue and the skeletal muscle, and the effect in the liver is secondary. Gene expression profiling using microarray and real-time PCR show significant changes in the expression of four genes--Vamp2, Dok1, Glut4 and Mapk14--involved in insulin signaling. The expression of Atp10c is also significantly altered in the adipose tissue and the soleus muscle. The most striking observation is the loss of Atp10c expression in the mutants, specifically in the soleus muscle, after eating the high-fat diet for 12 weeks. In conclusion, experiments suggest that the target genes and/or their cognate factors in conjunction with Atp10c presumably affect the normal translocation and sequestration of GLUT4 in both the target tissues.

]]> Madhu S. Dhar et al. Effects of intravenously administrated omeprazole on gastric juice pH and gastric ulcer scores in adult horses http://works.bepress.com/carla_sommardahl/13 http://works.bepress.com/carla_sommardahl/13 Sun, 02 Oct 2011 12:43:40 PDT The study was performed to evaluate the efficacy of omeprazole powder in sterile water, administered intravenously, on gastric juice pH in adult horses with naturally occurring gastric ulcers. Omeprazole (0.5 mg/kg, IV) was administered once daily for 5 days to 6 adult horses with gastric ulcers. Gastric juice was aspirated through the biopsy channel of an endoscope and pH was measured before and 1 hour after administration of omeprazole on day 1, and then before and after administration of omeprazole on day 5. Gastric ulcer scores were recorded on day 1 before administration of omeprazole and on day 5, 23 hours after the 4th daily dose. Gastric juice pH and ulcer scores were compared between the times. When compared with the pre-injection value (2.01 +/- 0.42), mean +/- SD gastric juice pH was significantly higher when measured 1 hour after administration of the initial dose (4.35 +/- 2.31), and before (5.27 +/- 1.74) and 1 hour after (7.00 +/- 0.25) administration of omeprazole on day 5. Nonglandular gastric ulcer number score significantly decreased from a mean +/- SD of 3.2 +/- 0.80 to 2.0 +/- 1.1, but nonglandular gastric ulcer severity score remained the same. Few glandular ulcers were seen in the study, and scores did not change. Because of its potent and long duration of action on gastric juice pH, this intravenous formulation of omeprazole may show promise for treatment of equine gastric ulcer syndrome (EGUS) in horses with dysphagia, gastric reflux, or other conditions that restrict oral intake of omeprazole paste. Aspiration of gastric juice and measurement of pH can be of use to determine whether the desired pH > 4.0 has been reached after omeprazole treatment.

]]> Frank M. Andrews et al. Use of a constant rate infusion of insulin for the treatment of hyperglycemic, hypernatremic, hyperosmolar syndrome in an alpaca cria http://works.bepress.com/carla_sommardahl/12 http://works.bepress.com/carla_sommardahl/12 Sun, 02 Oct 2011 12:41:02 PDT CASE DESCRIPTION: A 3-day-old 9.5-kg (21-lb) female alpaca cria was examined because of lethargy and anorexia. CLINICAL FINDINGS: Physical examination revealed hyperthermia, muscle fasciculations, and tremors of the head. Seizures were also observed, which indicated CNS dysfunction. Hyperosmolar syndrome (HOS) was diagnosed on the basis of hyperglycemia, hypernatremia, azotemia, high plasma osmolarity, and metabolic acidosis. TREATMENT AND OUTCOME: A constant rate infusion of regular insulin was administered with hypo-osmolar fluids to treat HOS, and blood glucose and sodium concentrations were successfully lowered. Neurologic deficits resolved with treatment, and the cria was discharged 11 days after admission. CLINICAL RELEVANCE: Administration of insulin as a bolus in addition to hypo-osmolar fluids has been advocated in the management of neonatal camelids with HOS. Administration of regular insulin via a constant rate IV infusion was used to successfully manage a neonatal camelid with HOS. This form of insulin administration may allow more control of glucose kinetics in these patients

]]> T Buchheit et al. A multicenter retrospective study of 151 renal biopsies in horses http://works.bepress.com/carla_sommardahl/11 http://works.bepress.com/carla_sommardahl/11 Sun, 02 Oct 2011 12:37:43 PDT BACKGROUND: Renal biopsies are uncommonly performed in horses and little is known about their diagnostic utility and associated complication rate. OBJECTIVE: To describe the techniques, the complication rate, risk factors, and histopathology results; as well as evaluate the safety and diagnostic utility of renal biopsy in the horse. ANIMALS: One hundred and forty-six horses from which 151 renal biopsies were obtained. Animals ranged in age from 48 hours to 30 years. METHODS: Multicenter retrospective study, with participation of 14 institutions (1983-2009). RESULTS: Renal biopsy in horses was associated with a similar rate of complications (11.3%) to that occurring in humans and companion animals. Complications were generally associated with hemorrhage or signs of colic, and required treatment in 3% of cases. Fatality rate was low (1/151; 0.7%). Biopsy specimens yielded sufficient tissue for a histopathologic diagnosis in most cases (94%) but diagnoses had only fair (72%) agreement with postmortem findings. Risk factors for complications included biopsy specimens of the left kidney (P = .030), a diagnosis of neoplasia (P = .004), and low urine specific gravity (P = .030). No association with complications was found for age, sex, breed, institution, presenting complaint, other initial clinicopathologic data, biopsy instrument, needle size, or use of ultrasonographic guidance. CONCLUSIONS AND CLINICAL IMPORTANCE: Renal biopsy in horses has low morbidity and results in a morphological histopathologic diagnosis in 94% of cases. However, this procedure might result in serious complications and should only be used when information obtained would be likely to impact decisions regarding patient management and prognosis.

]]> G A. Tyner et al. Effects of intravenously administered esomeprazole sodium on gastric juice pH in adult female horses http://works.bepress.com/carla_sommardahl/10 http://works.bepress.com/carla_sommardahl/10 Sun, 02 Oct 2011 12:31:46 PDT BACKGROUND: Gastric ulcers are common in horses and treatment of horses that cannot be administered oral medication can be problematic. OBJECTIVES: To evaluate the efficacy of esomeprazole sodium administered intravenously on gastric juice pH and gastric ulcer scores in horses. ANIMALS: Twelve adult female Quarter Horses. METHODS: Esomeprazole sodium (0.5 mg/kg IV) was administered once daily to 8 horses (treatment group) and saline (5 mL IV) was administered to 4 horses (control group) for 13 consecutive days. Gastroscopy was performed and gastric juice pH and gastric ulcer score were recorded before and 1 hour after the administration of esomeprazole sodium or saline on days 1 and 5, then on day 14, 23 hours after the 13th daily dose of esomeprazole sodium or saline. RESULTS: When compared with values before treatment, gastric juice pH was higher in esomeprazole sodium-treated horses after treatment (4.25 ± 2.39 versus 6.43 ± 1.18; P = .002). Also, gastric juice pH was higher (P = .001) in esomeprazole sodium-treated horses compared with saline-treated control horses on day 5 and on day 14 values. Gastric ulcers were seen in 5/12 (43%) horses in the study. CONCLUSIONS AND CLINICAL IMPORTANCE: Esomeprazole sodium shows promise for treatment of gastric ulcers in horses with signs of dysphagia, gastric reflux, or other conditions that restrict oral intake of the current Federal Drug Administration-approved omeprazole paste.

]]> Ricardo Videla et al. Effects of Intravenously Administrated Omeprazole on Gastric Juice pH and Gastric Ulcer Scores in Adult Horses http://works.bepress.com/carla_sommardahl/9 http://works.bepress.com/carla_sommardahl/9 Wed, 31 Aug 2011 13:21:00 PDT The study was performed to evaluate the efficacy of omeprazole powder in sterile water, administered intravenously, on gastric juice pH in adult horses with naturally occurring gastric ulcers. Omeprazole (0.5 mg/kg, IV) was administered once daily for 5 days to adult horses with gastric ulcers. Gastric juice was aspirated through the biopsy channel of an endoscope and pH was measured before and 1 hour after administration of omeprazole on day 1, and then before and after administration of omeprazole on day 5. Gastric ulcer scores were recorded on day 1 before administration of omeprazole and on day 5, 23 hours after the 4th daily dose. Gastric juice pH and ulcer scores were compared between the times. When compared with the pre-injection value (2.01 ± 0.42), mean ± SD gastric juice pH was significantly higher when measured 1 hour after administration of the initial dose (4.35 ± 2.31), and before (5.27 ± 1.74) and 1 hour after (7.00 ± 0.25) administration of omeprazole on day 5. Nonglandular gastric ulcer number score significantly decreased from a mean ± SD of 3.2 ± 0.80 to 2.0 ± 1.1, but nonglandular gastric ulcer severity score remained the same. Few glandular ulcers were seen in the study, and scores did not change. Because of its potent and long duration of action on gastric juice pH, this intravenous formulation of omeprazole may show promise for treatment of equine gastric ulcer syndrome (EGUS) in horses with dysphagia, gastric reflux, or other conditions that restrict oral intake of omeprazole paste. Aspiration of gastric juice and measurement of pH can be of use to determine whether the desired pH > 4.0 has been reached after omeprazole treatment. DOI: 10.1111/j.1939-1676.2006.tb00723.x

]]> Frank M. Andrews et al. Successful treatment of a sinonasal cryptococcal granuloma in a horse http://works.bepress.com/carla_sommardahl/8 http://works.bepress.com/carla_sommardahl/8 Wed, 31 Aug 2011 13:06:35 PDT Case Description—A 12-year-old 500-kg (1,100-lb) American Quarter Horse mare was evaluated because of chronic mucopurulent, bloody discharge from the left nostril, inspiratory dyspnea, and respiratory noise.

Clinical Findings—The horse had severe inspiratory dyspnea and stertorous respiration with no airflow from the left nostril. A temporary tracheostomy was performed. Endoscopy revealed a tan mass protruding from the left middle nasal meatus into the left common nasal meatus; it extended caudally into the nasopharynx and around the caudal edge of the nasal septum into the right nasal cavity. Radiographically, a soft tissue opacity was evident in most of the left nasal cavity and left paranasal sinuses. Cytologic examination of mass tissue revealed evidence of pyogranulomatous rhinitis; thickly encapsulated, budding yeast typical of Cryptococcus neoformans were detected.

Treatment and Outcome—While the horse was sedated and in a standing position, the fungal granuloma was removed from the paranasal sinuses. Treatment with fluconazole (5 mg/kg [2.27 mg/lb], PO, q 24 h for 4 weeks) was initiated; enilconazole (50 mL of a 10% solution) was instilled into the paranasal sinuses every other day (7 lavages). Six weeks after surgery, infection had not recurred and epithelialization appeared normal in the left paranasal sinuses.

Clinical Relevance—In horses with cryptococcosis of the paranasal sinuses, surgical removal of granulomatous lesions and systemic and topical administrations of antifungal drugs may be curative. Successful surgery may be performed in standing horses. Concommitant removal of a large portion of the conchae allows follow-up rhinoscopic evaluation of the paranasal sinuses. DOI: 10.2460/javma.234.4.509

]]> V. Claudia Cruz et al. A Type IV P-type ATPase Affects Insulin-mediated Glucose Uptake in Adipose Tissue and Skeletal Muscle in Mice http://works.bepress.com/carla_sommardahl/7 http://works.bepress.com/carla_sommardahl/7 Mon, 29 Aug 2011 08:18:15 PDT Mice carrying two pink-eyed dilution (p) locus heterozygous deletions represent a novel polygenic mouse model of type 2 diabetes associated with obesity. Atp10c, a putative aminophospholipid transporter on mouse chromosome 7, is a candidate for the phenotype. The phenotype is diet-induced. As a next logical step in the validation and characterization of the model, experiments to analyze metabolic abnormalities associated with these mice were carried out. Results demonstrate that mutants (inheriting the p deletion maternally) heterozygous for Atp10c are hyperinsulinemic, insulin-resistant and have an altered insulin-stimulated response in peripheral tissues. Adipose tissue and the skeletal muscle are the targets, and GLUT4-mediated glucose uptake is the specific metabolic pathway associated with Atp10c deletion. Insulin resistance primarily affects the adipose tissue and the skeletal muscle, and the effect in the liver is secondary. Gene expression profiling using microarray and real-time PCR show significant changes in the expression of four genes — Vamp2, Dok1, Glut4 and Mapk14 — involved in insulin signaling. The expression of Atp10c is also significantly altered in the adipose tissue and the soleus muscle. The most striking observation is the loss of Atp10c expression in the mutants, specifically in the soleus muscle, after eating the high-fat diet for 12 weeks. In conclusion, experiments suggest that the target genes and/or their cognate factors in conjunction with Atp10c presumably affect the normal translocation and sequestration of GLUT4 in both the target tissues.

]]> Madhu S. Dhar et al. Diagnostic value of a combined dexamethasone suppression/thyrotropin-releasing hormone stimulation test in Equine Cushing's disease http://works.bepress.com/carla_sommardahl/6 http://works.bepress.com/carla_sommardahl/6 Mon, 29 Aug 2011 08:18:13 PDT A combined dexamethasone suppression/thyrotropin releasing hormone (DEX/TRH) test is being used in the early diagnosis of Equine Cushing's disease (ECD), but the accuracy of this test has not been established. In this study, horses were tested using the DEX/TRH test, and the results were compared with the "gold standard" of histopathologic examination of the pituitary gland. Sensitivity and specificity of the test were 88% and 79%, respectively. Predictive values of positive and negative tests in our study population were 81% and 87%, respectively. When the test was applied to horses 11 yr old, the DEX/TRH test had greater accuracy in identifying horses with ECD.

]]> Frank M. Andrews et al. Effect of a 24-hour infusion of an isotonic electrolyte replacement fluid on the renal clearance of electrolytes in healthy neonatal foals http://works.bepress.com/carla_sommardahl/5 http://works.bepress.com/carla_sommardahl/5 Mon, 29 Aug 2011 08:18:11 PDT Objective - To determine the effects of a 24-hour infusion of an isotonic electrolyte replacement fluid (IERF) on weight, serum and urine electrolyte concentrations, and other clinicopathologic variables in healthy neonatal foals. Animals - 4 healthy 4-day-old foals. Design - Prospective study. Procedure - An IERF was administered to each foal at an estimated rate of 80 mL/kg/d (36.4 mL/lb/d) for 24 hours. Body weight was measured before and after the infusion period. Urine was collected via catheter during 4-hour periods; blood samples were collected at 4-hour intervals. Variables including urine production; urine and serum osmolalities; sodium, potassium, and chloride concentrations in urine and serum; urine and serum creatinine concentrations; urine osmolality-to-serum osmolality ratio (OsmR); transtubular potassium gradient (TTKG); and percentage creatinine clearance (Crcl) of electrolytes were recorded at 0, 4, 8, 12, 16, 20, and 24 hours during the infusion period. Immediately after the study period, net fluid and whole-body electrolyte changes from baseline values were calculated. Results - Compared with baseline values, urine and serum sodium and chloride serum concentrations, urine and serum osmolalities, OsmR, and percentage Crcl of sodium and chloride were significantly increased at various time points during the infusion; urine production did not change significantly. After 24 hours, weight, TTKG, serum creatinine concentration, and whole-body potassium had significantly decreased from baseline values. Conclusions and Clinical Relevance - Results suggest that administration of an IERF containing a physiologic concentration of sodium may not be appropriate for use in neonatal foals that require maintenance fluid therapy.

]]> B R. Buchanan et al. Idiopathic Systematic Granulomatous Disease http://works.bepress.com/carla_sommardahl/4 http://works.bepress.com/carla_sommardahl/4 Mon, 29 Aug 2011 08:18:09 PDT Sandra Sargent et al. Mice Heterozygous for Atp10c, a Putative Amphipath, Represent a Novel Model of Obesity and Type 2 Diabetes http://works.bepress.com/carla_sommardahl/3 http://works.bepress.com/carla_sommardahl/3 Mon, 29 Aug 2011 08:18:06 PDT Atp10c is a novel type IV P-type ATPase and is a putative phospholipid transporter. The purpose of this study was to assess the overall effect of the heterozygous deletion of Atp10c on obesity-related phenotypes and metabolic abnormalities in mice fed a high-fat diet. Heterozygous mice with maternal inheritance of Atp10c were compared with heterozygous mice with paternal inheritance of Atp10c and wild-type controls. Body weight, adiposity index, and plasma insulin, leptin and triglyceride concentrations were significantly greater in the mutants inheriting the deletion maternally compared with their sex- and age-matched control male mice fed a 10% fat (% energy) diet and female mice fed a 45% fat (% energy) diet. Glucose and insulin tolerance tests were performed after mice consumed the diets for 4 and 8 wk. Mutants had altered glucose tolerance and insulin response compared with controls, suggesting insulin resistance in both sexes. Mice were killed at 12 wk and routine gross and histological evaluations of the liver, pancreas, adipose tissue, and heart were performed. Histological evaluation showed micro- and macrovesicular lipid deposition within the hepatocytes that was more severe in the mutant mice than in age-matched controls. Although sex differences were observed, our data suggest that heterozygous deletion along with an unusual pattern of maternal inheritance of the chromosomal region containing the single gene, Atp10c, causes obesity, type 2 diabetes, and nonalcoholic fatty liver disease in these mice.

]]> Madhu S. Dhar et al.