bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma Clearance of Exogenous Creatinine, Exo‐Iohexol, and Endo‐Iohexol in Hyperthyroid Cats before and after Treatment with Radioiodine
Authors: Van Hoek I. , Lefebvre H.P. , Kooistra H.S. , Croubels S. , Binst D. , Peremans K. , Daminet S.
Published: January 2009

Background:Glomerular filtration rate (GFR) can be measured by clearance methods of different markers showing discrepancies and different reproducibility in healthy cats. Studies comparing different methods of GFR measurement in hyperthyroid cats have not yet been performed.

Hypothesis:Plasma clearance of exogenous creatinine (PECCT), exo‐iohexol (PexICT), and endo‐iohexol (PenICT) could lead to differences in GFR measurement and the need to use the same clearance method when comparing GFR before and after radioiodine treatment in hyperthyroid cats.

Animals:Fifteen client‐owned hyperthyroid cats.

Methods:GFR was measured 1 day before and 1, 4, 12, and 24 weeks after treatment. Intravenous injection of iohexol was followed immediately by IV injection of creatinine. Plasma creatinine was measured by an enzymatic method. Plasma endo‐ and exo‐iohexol were measured by high‐performance liquid chromatography coupled to ultraviolet detection.

Results:Globally, the 3 GFR methods resulted in significantly different (P< .001) GFR results. GFR results among the different methods were the same (P= .999) at all time points. All 3 techniques indicated decreasing GFR after131I treatment. For each GFR technique, a significant decrease in GFR was observed between time point 0 and all other time points. This decrease stabilized 4 weeks after treatment, with very little decline afterward.

Conclusion and Clinical Importance:It is mandatory to use the same GFR technique in follow‐up studies. GFR testing at 4 weeks posttreatment could allow assessment of the final renal functional loss after treatment in hyperthyroid cats.
Pulmonary Dysfunction and Skeletal Muscle Changes in Horses with RAO
Authors: Gehlen H. , Oey L. , Rohn K. , Bilzer T. , Stadler P.
Published: January 2009

Background: Chronic pulmonary diseases (recurrent airway obstruction [RAO]) have been reported to alter skeletal muscle cells in humans. The purpose of this study was to evaluate a potential relationship between pulmonary and muscle variables in horses with a clinical diagnosis of RAO. Muscle biopsies from healthy horses and from horses with RAO were investigated and the relationship between the severity of lung disease and the degree of muscular changes was determined.

Hypothesis: We hypothesized that chronic pulmonary disease can lead to changes of the skeletal muscle in horses.

Animals: Fifteen healthy horses (control) and 50 horses with RAO were examined.

Methods: In a prospective clinical trial, a complete lung examination was performed in all horses. In all horses, muscle enzyme activity at rest and after exercise and muscle biopsies from the M. gluteus medius were examined.

Results: None of the horses had clinical or histologic signs of primary or neurogenic myopathies. According to the clinical, endoscopic, and radiographic findings and with a scoring system, the horses with RAO were grouped according to the severity of pulmonary findings (15 horses mild, 24 horses moderate, 11 horses severe RAO). Pathologic changes of the skeletal muscle (fiber atrophy or fiber hypertrophy, myofibrillar degeneration, hyperplasia of mitochondria, and ragged‐red‐like fibers) were identified in most horses with RAO but in only a few individual control horses. In addition, a marked depletion of muscle glycogen storage was evident in the RAO horses but not in the control group. Other pathologic changes of skeletal muscle such as centralized nuclei and regenerating fibers were rare, but were more frequent in horses with lung diseases than in the control group. The degree of muscle cell changes was also graded with a scoring system and correlated with the severity of pulmonary disease (r= 0.55).

Conclusion: Chronic pulmonary disease in horses is associated with structural changes in skeletal muscle.

Clinical Importance: Because chronic pulmonary disease may affect muscles, early and effective therapy may prevent these changes. This finding could be of clinical importance but requires further studies.
Prevalence of the Myosin‐Binding Protein C Mutation in Maine Coon Cats
Authors: Fries R. , Heaney A.M. , Meurs K.M.
Published: January 2009

Background: An autosomal dominant mutation has been identified in the myosin‐binding protein C (MYBPC3) gene of Maine Coon cats. This mutation changes a conserved amino acid and computationally alters the protein conformation of this gene in Maine Coon cats with hypertrophic cardiomyopathy. The prevalence of this mutation is unknown.

Objective: To determine the genetic prevalence of the MYBPC3 mutation in a large cohort of predominantly Maine Coon cats.

Animals: Three thousand three hundred and ten DNA samples (blood or buccal swab) from cats.

Methods: This retrospective study reviewed the Veterinary Cardiac Genetics Laboratory database at Washington State University for samples submitted for evaluation of the Maine Coon MYBPC3 mutation. The data were analyzed with respect to the breed of cat, mutation status (negative, heterozygous, homozygous), and geographic origin of the submission.

Results: In the population of cats studied, Maine Coon cats accounted for 100% of all cats positive for the mutation, and the worldwide percentage of Maine Coon cats carrying the MYBPC3 mutation was 34%.

Conclusions and Clinical Importance: The prevalence of the mutation (heterozygous or homozygous) was very similar among countries of submission, suggesting that the 34% mutation rate of the tested samples is a reasonable estimate of the true prevalence of the mutation within the breed. Because of the high prevalence of this mutation, a breeding recommendation to eliminate all cats with the mutation could have a substantial impact on the gene pool. Additional studies are indicated to explore the relationship between genotype and clinical outcome in affected cats.
Echocardiographic Ratio Indices in Overtly Healthy Boxer Dogs Screened for Heart Disease
Authors: Cunningham S.M. , Rush J.E. , Freeman L.M. , Brown D.J. , Smith C.E.
Published: January 2009

Background:Boxer dogs are routinely screened by echocardiography to exclude congenital and acquired heart disease. Individuals of a given breed may span a large range of body sizes, potentially invalidating linear regression of M‐mode measurements against body weight. Echocardiographic ratio indices (ERIs) provide a novel method of characterizing echocardiographic differences between Boxers and other dog breeds.

Hypothesis:ERIs obtained from overtly healthy Boxer dogs presented for cardiac screening will be different from ERIs established for normal non‐Boxer dogs, and those differences will be unrelated to aortic velocity or systolic blood pressure.

Animals:Eighty‐one Boxers with no outward clinical signs of heart disease were studied.

Methods:All dogs were examined by 2‐dimensional, M‐mode, and Doppler echocardiography. M‐mode measurements were used to perform ERI calculations, and the indices in Boxers were compared between Boxers with varying severity of arrhythmia and those of normal non‐Boxer dogs.

Results:Differences in weight‐based ERIs, which reflect increased thickness of the left ventricular free wall (LVW) and interventricular septum (IVS) and smaller aortic size, were found in overtly healthy Boxer dogs compared with normal non‐Boxer dogs. ERIs of left atrial and LV cavity size in overtly healthy Boxers were not significantly different from those of non‐Boxer dogs.

Conclusions and Clinical Importance:Boxer dogs may have an increased relative thickness of the LVW and IVS that is independent of aortic size, aortic velocity, or arterial blood pressure, and this morphology should be taken into consideration when screening Boxers by echocardiography.
ABCB1‐1Δ Polymorphism Can Predict Hematologic Toxicity in Dogs Treated with Vincristine
Authors: Mealey K.L. , Fidel J. , Gay J.M. , Impellizeri J.A. , Clifford C.A. , Bergman P.J.
Published: January 2009

Background:Dogs that harbor the naturally occurring ABCB1‐1Δ polymorphism experience increased susceptibility to avermectin‐induced neurological toxicosis as a result of deficient P‐glycoprotein function. Whether or not the ABCB1‐1Δ polymorphism affects susceptibility to toxicity of other P‐glycoprotein substrate drugs has not been studied.

Hypothesis:Dogs that possess the ABCB1‐1Δ mutation are more likely to develop hematologic toxicity associated with vincristine than ABCB1 wild‐type dogs.

Animals:Thirty‐four dogs diagnosed with lymphoma were included in this study.

Methods:Cheek swab samples were obtained from dogs diagnosed with lymphoma that were to be treated with vincristine. DNA was extracted from cheek swabs and the ABCB1 genotype was determined. Hematologic adverse drug reactions were recorded for each dog and graded according to the Veterinary Comparative Oncology Group's criteria for adverse event reporting (Consensus Document). In order to avoid possible bias, ABCB1 genotype results for a particular patient were not disclosed to oncologists until an initial adverse event report had been submitted.

Results:Dogs heterozygous or homozygous for the ABCB1‐1Δ mutation were significantly more likely to develop hematologic toxicity, specifically neutropenia (P= .0005) and thrombocytopenia (P= .0001), after treatment with vincristine than ABCB1 wild‐type dogs.

Conclusions and Clinical Implications:At currently recommended dosages (0.5–0.7 mg/M2), vincristine is likely to cause hematologic toxicity in dogs with the ABCB1‐1Δ mutation, resulting in treatment delays and unacceptable morbidity and mortality. Assessing the ABCB1‐1Δ genotype before vincristine administration and decreasing the dosage may prevent toxicity and treatment delays resulting from neutropenia or thrombocytopenia.
Gastrointestinal Pythiosis in 10 Dogs from California
Authors: Berryessa N.A. , Marks S.L. , Pesavento P.A. , Krasnansky T. , Yoshimoto S.K. , Johnson E.G. , Grooters A.M.
Published: January 2009

Background: Pythium insidiosum is an aquatic oomycete that causes severe segmental thickening of the canine gastrointestinal (GI) tract, resulting in weight loss, vomiting, diarrhea, and death. Infection in dogs previously has been observed primarily in the southeastern United States.

Objective: To describe the clinicopathologic and epidemiologic findings associated with GI pythiosis in 10 dogs from California.

Methods: Dogs were initially identified on the basis of supportive clinical findings and routine histology. Pythiosis was confirmed in each dog with at least one of the following: immunoblot serology, enzyme‐linked immunosorbent assay serology, immunohistochemistry, and culture followed by species‐specific polymerase chain reaction, rRNA gene sequencing, or both.

Results: Between September 2003 and December 2006, GI pythiosis was confirmed in 1 dog from central California and 9 dogs that lived within a 30‐mile radius of Davis, CA. Seven of 8 dogs for which environmental data were available had frequent access to flooded rice fields or other water sources. Esophageal lesions were present in 2 of 10 dogs. Common laboratory findings included eosinophilia (7/9), hypoalbuminemia (9/9), and hyperglobulinemia (8/9). Median survival time was 26.5 days (range, 0–122 days), and the disease was ultimately fatal in all 10 dogs.

Conclusions and Clinical Importance: The geographic distribution of pythiosis has widened in recent years to include the western United States. Factors that may have contributed to this change include altered rice‐farming practices and landscape irrigation. Veterinarians in California should be familiar with the clinicopathologic features associated with GI pythiosis to aid in early diagnosis and effective treatment.
Effects of Aging on Brainstem Responses to Toneburst Auditory Stimuli: A Cross‐Sectional and Longitudinal Study in Dogs
Authors: Ter Haar G. , Venker‐van Haagen A.J. , Van Den Brom W.E. , Van Sluijs F.J. , Smoorenburg G.F.
Published: January 2009

Background:It is assumed that the hearing of dogs becomes impaired with advancing age, but little is known about the prevalence and electrophysiologic characteristics of presbycusis in this species.

Hypothesis:As in humans, hearing in dogs becomes impaired with aging across the entire frequency range, but primarily in the high‐frequency area. This change can be assessed quantitatively by brainstem‐evoked response audiometry (BERA).

Animals:Three groups of 10 mixed‐breed dogs with similar body weights but different mean ages were used. At the start of the study, the mean age was 1.9 years (range, 0.9–3.4) in group I, 5.7 years (3.5–7) in group II, and 12.7 years (11–14) in group III.

Methods:In a cross‐sectional study, the BERA audiograms obtained with toneburst stimuli were compared among the 3 groups. In a longitudinal study, changes in auditory thresholds of group II dogs were followed for 7 years.

Results:Thresholds were significantly higher in group III than in groups I and II at all frequencies tested, and higher in group II than in group I at 4 kHz. The audiograms in group II indicated a progressive increase in thresholds associated with aging starting around 8–10 years of age and most pronounced in the middle‐ to high‐frequency region (8–32 kHz).

Conclusions and Clinical Importance:Age‐related hearing loss in these dogs started around 8–10 years of age and encompassed the entire frequency range, but started and progressed most rapidly in the middle‐ to high‐frequency area. Its progression can be followed by BERA with frequency‐specific stimulation.
Utility of 12‐Lead Electrocardiogram for Differentiating Paroxysmal Supraventricular Tachycardias in Dogs
Authors: Santilli R.A. , Perego M. , Crosara S. , Gardini F. , Bellino C. , Moretti P. , Spadacini G.
Published: January 2009

Background:The 12‐lead surface ECG is validated for differentiating supraventricular tachycardias (SVT) in humans. Despite the description of SVT in veterinary medicine, no studies have analyzed the electrocardiographic features of this type of arrhythmias in dogs.

Objective:To describe the specific electrocardiographic criteria used to differentiate the most common SVT in dogs.

Animals:Twenty‐three dogs examined at Clinica Veterinaria Malpensa for SVT with the mechanism documented by electrophysiologic studies (EPS).

Methods:Twelve‐lead electrocardiographic variables obtained from 14 dogs with orthodromic atrioventricular reciprocating tachycardia (OAVRT) and 9 dogs with focal atrial tachycardia (FAT) were compared.

Results:Dogs with FAT had faster heart rates (278 ± 62 versus 229 ± 42 bpm;P= .049) and less QRS alternans (33 versus 86%;P= .022). P waves appeared during tachycardia in 22 dogs, with a superior axis in 100% of OAVRT and 22% of FAT (P< .001). OAVRT was characterized by a shorter RP interval (85.0 ± 16.8 versus 157.1 ± 37.3 ms;P< .001) and smaller RP/PR ratio (0.60 ± 0.18 versus 1.45 ± 0.52;P< .001). Repolarization anomalies were present in 64% of OAVRT and no FAT (P< .001). Multivariate analysis identified QRS alternans and a positive P wave in aVR during tachycardia as independent predictors of arrhythmia type.

Conclusion and Clinical Importance:Electrocardiographic criteria used in people for differentiating SVT can also be applied in dogs.
Cancer Incidence in Pet Dogs: Findings of the Animal Tumor Registry of Genoa, Italy
Authors: Merlo D.F. , Rossi L. , Pellegrino C. , Ceppi M. , Cardellino U. , Capurro C. , Ratto A. , Sambucco P.L. , Sestito V. , Tanara G. , Bocchini V.
Published: January 2009

Background: The occurrence of spontaneous tumors in pet animals has been estimated in a few European and North American veterinary cancer registries with dissimilar methodologies and variable reference populations.

Objectives: The Animal Tumor Registry (ATR) of Genoa, Italy, was established in 1985 with the aim of estimating the occurrence of spontaneous tumors in dogs.

Methods: Six thousand seven hundred and forty‐three tumor biopsy specimens were received from local veterinarians in the Municipality of Genoa between 1985 and 2002. Three thousand and three hundred and three (48.9%) biopsy specimen samples were diagnosed as cancer and were coded according to the International Statistical Classification of Diseases (ICD‐9).

Results: Mammary cancer was the most frequently diagnosed cancer in female dogs, accounting for 70% of all cancer cases. Incidence of all cancers was 99.3 per 100,000 dog‐years (95% CI: 93.6–105.1) in male dogs and 272.1 (95% CI: 260.7–283.6) in female dogs. The highest incidence rates were detected for mammary cancer (IR = 191.8, 95% CI: 182.2–201.4) and for non‐Hodgkin's lymphoma (IR = 22.9, 95% CI: 19.7–26.5) in bitches and for non‐Hodgkin's lymphoma (IR = 19.9, 95% CI: 17.4–22.7) and skin cancer (IR = 19.1, 95% CI: 16.6–21.8) in male dogs. All cancer IR increased with age ranging between 23.7 (95% CI: 18.4–30.1) and 763.2 (95% CI: 700.4–830.1) in bitches and between 16.5 (95% CI: 12.8–21.1) and 237.6 (95% CI: 209.1–269.0) in male dogs aged ≤3 years and >9–11 years.

Conclusion: This study summarizes the work done by the ATR of Genoa, Italy, between 1985 and 2002. All cancer incidence was 3 times higher in female than in male dogs, a difference explained by the high rate of mammary cancer observed in bitches. Because a biopsy specimen was required to make a cancer diagnosis, cancer rates for internal organs cancers, such as respiratory and digestive tract cancers may have been underestimated in the study population.
Demographics and Costs of Colic in Swedish Horses
Authors: Egenvall A. , Penell J. , Bonnett B.N. , Blix J. , Pringle J.
Published: January 2009

Background:Colic is an important cause of morbidity and mortality in horses. In Sweden, an insurance database with diagnostic medical information is maintained on >30% of the nation's horse population.

Hypothesis:The objective was to describe the occurrence of colic, defined by costly veterinary care and life claims, in horses at 1 insurance company during 1997–2002.

Horses:All horses (<21 years of age) with complete insurance for veterinary care and life during the period 1997–2002 were included.

Methods:Colic was defined as conditions where the main clinical sign was abdominal pain and the problem was related to the gastrointestinal system. The analyses included measures of incidence by sex, breed group, age categories, geographical location (urban/other), survival to and survival after colic, medical cost for colic, and multivariable modeling of risk factors related to the event of colic.

Results:In all, 116,288 horses contributed to 341,564 horse years at risk (HYAR). There were 3,100 horses with a colic diagnosis, of which 27% were settled for life insurance. The median gross cost for veterinary care was 4,729 Swedish Kronor (SEK). The overall occurrence and mortality rate of colic was 91 and 24 events per 10,000 HYAR. Survival after colic at 1 month was 76% (95% confidence interval: 75–78%).

Conclusions and Clinical Importance:The occurrence of colic varied with breed group, age, and season. The mortality rates probably reflected the true mortality of colic. The veterinary care rates most likely underestimated of the risk colic because they represent relatively costly events.
Computer‐Assisted Magnetic Resonance Imaging Brain Morphometry in American Staffordshire Terriers with Cerebellar Cortical Degeneration
Authors: Henke D. , Böttcher P. , Doherr M.G. , Oechtering G. , Flegel T.
Published: January 2009

Background:Cerebellar cortical degeneration exists in American Staffordshire Terriers. Magnetic resonance imaging (MRI) can be suggestive, but a definitive diagnosis requires histopathology.

Hypothesis:Computer‐assisted MRI morphometry can be used to distinguish between American Staffordshire Terriers with or without cerebellar cortical degeneration.

Animals:Normal American Staffordshire Terriers (n = 17) and those with clinical signs of cerebellar cortical degeneration (n = 14).

Methods:This was a partly retrospective and partly prospective study. Causes of cerebellar disease were ruled out with brain MRI, cerebrospinal fluid (CSF) analysis, CBC, blood biochemistry, and clinical follow‐up. On T2‐weighted midsagittal MR images, the following parameters were calculated: size of the cerebellum relative to the entire brain, size of the CSF space surrounding the cerebellum relative to the cerebellum, and 2 threshold‐dependent cerebellar CSF indices (with and without surrounding CSF).

Results:Statistical analyses indicated a significantly lower relative cerebellar size (P< .001) and a larger relative cerebellar CSF space (P< .001) in dogs with cerebellar cortical degeneration. The measurement of relative cerebellar size could distinguish between affected and nonaffected dogs with a sensitivity and a specificity of 93 and 94%, respectively, using a cut‐off of 13.3%. Using a cut‐off of 12.8%, the measurement of relative CSF space could distinguish between both groups with a sensitivity of 93% and a specificity of 100%. There was a significant difference in 1 of the 2 CSF indices between affected and normal dogs.

Conclusions and Clinical Importance:Relative cerebellar size and relative CSF space calculated from MRI are effective in American Staffordshire Terriers to differentiate between normal animals and those with cerebellar cortical degeneration.
Clinical Signs, Histology, and CD3‐Positive Cells before and after Treatment of Dogs with Chronic Enteropathies
Authors: Schreiner N.M.S. , Gaschen F. , Gröne A. , Sauter S.N. , Allenspach K.
Published: January 2009

Background: Histopathology is widely used for the diagnosis of inflammatory bowel disease in dogs. Variations in lesions and unavailability of uniform grading systems limit the usefulness of histologic examination.

Hypothesis: CD3 cell numbers in chronic enteropathies of dogs correlate with clinical activity of the disease and with severity of histopathologic changes.

Animals: Nineteen client‐owned dogs examined because of chronic diarrhea, vomiting, or both.

Methods: Samples of duodenal and colonic mucosa were collected endoscopically before and after treatment. Dogs that responded to a hypoallergenic diet were grouped as food‐responsive diarrhea dogs (FRD, n = 10). Dogs with no clinical improvement after 10 days of treatment then received prednisolone (immunosuppressive doses) and were grouped as steroid‐responsive diarrhea dogs (SRD, n = 9). Histopathologic assessment with a standardized grading system was performed retrospectively on the intestinal samples. Histologic score, total number of infiltrating cells, and CD3‐positive cells were counted and compared with the clinical scoring.

Results: No statistically significant difference was detected among histologic grading, total number of cells in the lamina propria, and T‐cell numbers in biopsies before and after treatment in either group (FRD and SRD).

Conclusions and Clinical Importance: Currently used histopathologic grading scores, total numbers of cells, and numbers of CD3‐positive cells did not allow differentiation between FRD and SRD and did not correlate with clinical response to therapy. Based on these results, new grading scores assessing other criteria than total cell numbers and CD3‐positive cells should be evaluated in the future.
Urinary Aldosterone to Creatinine Ratio in Cats before and after Suppression with Salt or Fludrocortisone Acetate
Authors: Djajadiningrat‐Laanen S.C. , Galac S. , Cammelbeeck S.E. , Van Laar K.J.C. , Boer P. , Kooistra H.S.
Published: January 2009

Background: The endocrine diagnosis of primary hyperaldosteronism in cats currently is based on an increased plasma aldosterone to renin ratio, which has several disadvantages for use in veterinary practice.

Objectives: To establish a reference range for the urinary aldosterone to creatinine ratio (UACR) and to determine whether oral administration of either sodium chloride or fludrocortisone acetate is effective for use in a suppression test.

Animals: Forty‐two healthy cats from an animal shelter and 1 cat with primary hyperaldosteronism from a veterinary teaching hospital.

Methods: Morning urine samples for determination of the basal UACR were collected from 42 healthy cats. For the suppression tests, urine samples for the UACR were collected after twice daily oral administration for 4 consecutive days of either sodium chloride, 0.25 g/kg body weight (n = 22) or fludrocortisone acetate, 0.05 mg/kg body weight (n = 15).

Results: The median basal UACR was 7.2 × 10−9 (range, 1.8–52.3 × 10−9), with a calculated reference range of <46.5 × 10−9. Administration of sodium chloride resulted in adequate salt loading in 10 of 22 cats, but without significant reduction in the UACR. Administration of fludrocortisone resulted in a significant decrease in the UACR (median, 78%; range, 44–97%; P < .001) in healthy cats. In the cat with an aldosterone‐producing adrenocortical carcinoma, the basal UACR and the UACR after fludrocortisone administration were 32 × 10−9 and 36 × 10−9, respectively.

Conclusions and Clinical Importance: Using the UACR for an oral fludrocortisone suppression test may be useful for the diagnosis of primary hyperaldosteronism in cats.
Factors Associated with Outcome in Foals with Neonatal Isoerythrolysis (72 Cases, 1988–2003)
Authors: Polkes A.C. , Giguère S. , Lester G.D. , Bain F.T.
Published: January 2009

Background:Neonatal foals with isoerythrolysis (NI) often die, but the risk factors for death have not been identified.

Objectives:To identify factors associated with outcome in foals with NI and to identify factors associated with death from liver failure or kernicterus in the same population.

Animals:Seventy‐two foals with NI examined at referral institutions.

Methods:Retrospective case series. Information on signalment, clinical examination findings, laboratory testing, treatment, complications, outcome, and necropsy results were obtained.

Results:The overall survival rate was 75% (54 of 72). Liver failure (n = 7), kernicterus (n = 6), and complications related to bacterial sepsis (n = 3) were the 3 most common reasons for death or euthanasia. The number of transfusions with blood products was the factor most strongly associated with nonsurvival in a multivariate logistic regression model. The odds of liver failure developing in foals receiving a total volume of blood products ≥ 4.0 L were 19.5 (95% confidence intervals [CI]: 2.13–178) times higher than that of foals receiving a lower volume (P= .009). The odds of kernicterus developing in foals with a total bilirubin ≥ 27.0 mg/dL were 17.0 (95% CI: 1.77–165) times higher than that of foals with a lower total bilirubin (P= .014).

Conclusions and Clinical Importance:Development of liver failure, kernicterus, and complications related to bacterial sepsis are the most common causes of death in foals with NI. Foals administered a large volume of blood products are at greater risk for developing liver failure.
Abnormalities in Lung Surfactant in Horses Clinically Affected with Recurrent Airway Obstruction (RAO)
Authors: Christmann U. , Welles E.G. , Waldridge B.M. , Schumacher J. , Grier B.L. , Hite R. D.
Published: January 2009

Background:Abnormalities in lung surfactant are well described in human respiratory diseases including asthma, but are poorly described in horses.

Hypothesis:Lung surfactant is abnormal in horses with clinical signs of recurrent airway obstruction (RAO).

Animals:Six healthy horses and 5 horses with RAO.

Methods:Bronchoalveolar lavage fluid (BALF) was obtained from all horses by standard procedures. Cell‐free BALF was separated into crude surfactant pellets (CSP) and supernatant via ultracentrifugation. Phospholipid and protein content was analyzed from both of these fractions. Phospholipid composition of CSP was determined using high‐performance liquid chromatography with an evaporative light scatter detector. Surface tension of CSP was measured with a pulsating bubble surfactometer.

Results:Compared with healthy horses, surfactant from RAO‐affected horses was characterized by significantly decreased phospholipid content in total surfactant (median; range: 23.2; 14.7–62.2 μg/mL BALF versus 172; 111–267 μg/mL BALF,P= .0062) and CSP (20.2; 6.4–48.9 μL/mL BALF versus 155; 94.4–248 μg/mL BALF,P= .0062), and a significantly lower percentage of phosphatidylglycerol (PG) (4.5; 3.6–5.6% versus 6.6; 4.1–7.6%,P= .028). Furthermore, the ratio between the percentages of phosphatidylcholine and PG was significantly higher in RAO‐affected horses than in healthy horses (20.9; 16.6: 25.9 versus 13.9; 11.8–22.8,P= .045).

Conclusions and Clinical Importance:This study demonstrates that surfactant from RAO‐affected horses is abnormal. Further studies are needed to determine if these abnormalities are related to an increased tendency for bronchoconstriction and to a decreased ability to clear airway mucus in RAO‐affected horses.
Clinical Features of Canine Granulocytic Anaplasmosis in 18 Naturally Infected Dogs
Authors: Kohn B. , Galke D. , Beelitz P. , Pfister K.
Published: January 2009

Background:Anaplasma phagocytophilum, the causative agent of canine granulocytic anaplasmosis (CGA), is a Gram‐negative intracellular organism transmitted by ixodid ticks. Thus far, only a few clinical studies evaluating dogs with CGA have been published.

Objectives:Evaluation of dogs naturally infected withA. phagocytophilumin which known co‐infections were excluded.

Animals:Eighteen dogs with CGA.

Methods:Prospective study. The diagnosis of CGA was based on a positive PCR test result; dogs with co‐infections were excluded. History, clinical findings, CBC, clinical biochemistry, infectious disease screening, diagnostic imaging, and the course of disease were evaluated.

Results:CGA was diagnosed based on a positive PCR test forA. phagocytophilum; 10 dogs also had morulae in neutrophils. Six of 18 dogs were seronegative toA. phagocytophilum, the others were seropositive. All dogs were acutely ill. The most common clinical findings were lethargy, inappetence, fever, and splenomegaly. Abnormal laboratory results included thrombocytopenia, anemia, lymphopenia, hypoalbuminemia, and abnormally high plasma alkaline phosphatase activity. In 6 of 10 dogs tested, the platelet‐bound antibody test was positive; Coombs' test was negative in 9 dogs. All dogs were treated with doxycycline and recovered. PCR testing as well as blood smear analysis for morulae were negative in 14 tested dogs 2–8 weeks after beginning treatment.

Conclusions and Clinical Importance:Clinical findings in dogs with CGA were nonspecific. Positive platelet‐bound antibody test results suggest immune‐mediated platelet destruction as an important pathogenic mechanism. With correct diagnosis and treatment, prognosis is good.
Transarterial Ductal Occlusion with the Amplatzer Vascular Plug in 31 Dogs
Authors: Achen S.E. , Miller M.W. , Gordon S.G. , Saunders A.B. , Roland R.M. , Drourr L.T.
Published: January 2009

Background: Transarterial ductal occlusion with the Amplatzer vascular plug was first reported in dogs by Hogan et al in 2005.

Hypothesis: Use of the Amplatzer vascular plug is a safe, efficacious method of patent ductus arteriosus (PDA) occlusion.

Animals: Thirty‐one client‐owned dogs with PDA.

Methods: Records of 31 dogs in which transarterial occlusion of PDA with an Amplatzer vascular plug was attempted were reviewed.

Results: All dogs had a type II PDA, with 27 dogs having type IIA morphology and 4 dogs having type IIB morphology. Appropriate device deployment was achieved in 29 of 31 dogs. Postdeployment angiography in 21 dogs documented complete occlusion in 10 dogs, trivial residual flow in 5 dogs, mild residual flow in 2 dogs, moderate residual flow in 3 dogs, and severe residual flow in 1 dog. Transthoracic color Doppler echocardiography documented complete occlusion in 22 dogs, whereas 2 dogs had trivial residual flow, 2 dogs had mild residual flow, 2 dogs had mild to moderate residual flow, and 1 dog had severe residual flow. Of the 7 dogs with residual flow, 2 had complete occlusion 2–4 months postoperatively, 1 had moderate residual flow 1 month postoperatively, and 4 were lost to follow‐up. One dog required a larger device than was able to be deployed through the largest sheath placed in the femoral artery. Pulmonary embolization of the device occurred in 1 dog.

Conclusion: We conclude that ductal occlusion with an Amplatzer vascular plug is a safe and efficacious therapy for PDA in dogs.
Lidocaine Converts Acute Vagally Associated Atrial Fibrillation to Sinus Rhythm in German Shepherd Dogs with Inherited Arrhythmias
Authors: Pariaut R. , Moïse N.S. , Koetje B.D. , Flanders J.A. , Hemsley S.A. , Farver T.B. , Gilmour R.F. , Gelzer A.R.M. , Kraus M.S. , Otani N.F.
Published: January 2009

Background: Lidocaine is most frequently used to treat ventricular arrhythmias. However, lidocaine may have an antiarrhythmic effect for certain supraventricular arrhythmias.

Hypothesis: We hypothesized that lidocaine would be effective in converting experimentally induced atrial fibrillation (AF) to sinus rhythm and that a decrease in the dominant frequency (DF) and an increase in the organization as judged by the spectral entropy (SE) would occur over the course of the conversion.

Animals: Seven German Shepherd (GS) Dogs.

Methods: Dogs were anesthetized with fentanyl and pentobarbital. AF was induced with standard pacing protocols while left and right atrial monophasic action potentials (MAP) were recorded. The power spectra from the MAP recordings were analyzed to determine DF and SE during treatment with boluses of 2 mg/kg lidocaine.

Results: Lidocaine converted AF to sinus rhythm in all dogs and all episodes (n = 19). Conversion time was 27–87 seconds. After atropine, sustained AF was not induced; however, 5 episodes of atrial tachycardia resulted, and 3 were converted with lidocaine. Frequency domain analysis of 12 conversion sequences showed that left and right DF of the MAP signals decreased from the time of injection to conversion to sinus rhythm (P < .001). Mean SE indicated a gradient between the left and right atria (P= .003) that did not change during conversion.

Conclusions and Clinical Importance: Vagally associated AF in GS dogs is terminated with lidocaine. Lidocaine is likely an effective treatment in clinical dogs with vagally associated AF.
Gestational Diabetes Mellitus in 13 Dogs
Authors: Fall T. , Johansson Kreuger S. , Juberget Å. , Bergström A. , Hedhammar Å.
Published: January 2009

Background: There are few reports on the clinical appearance, prognosis, and risk factors for gestational diabetes mellitus (GDM) in dogs.

Objective: To describe the clinical characteristics of GDM in dogs.

Animals: Thirteen dogs with GDM.

Methods: Retrospective study. Medical records were reviewed and owners and referring veterinarians were contacted for follow‐up information.

Results: Nordic Spitz breeds (11/13 dogs) were overrepresented in the case material. Diagnosis was established at a median of 50 days after mating (range, 32–64). Median glucose concentration at diagnosis was 340 mg/dL (18.9 mmol/L) (range, 203–587). One dog was euthanized at diagnosis, 5 bitches were treated with insulin until whelping, and in 7 dogs, pregnancy was terminated within 4 days of diagnosis. One dog died after surgery. Tight glycemic control was not achieved in any of the insulin‐treated dogs during pregnancy. Diabetes mellitus (DM) resolved in 7 dogs at a median of 9 days after the end of their pregnancies and DM was permanent in 4 dogs. Puppy mortality was increased compared with offspring of healthy dams.

Conclusion: This report suggests that GDM affects mainly middle‐aged bitches in the 2nd half of pregnancy with a breed predisposition toward Nordic Spitz breeds. GDM may resolve within days to weeks after pregnancy has ended. Further research is needed to investigate optimal treatment regimens for dogs with GDM and risk factors for unsuccessful outcome.
Atrial and Ventricular Electrical and Contractile Remodeling and Reverse Remodeling Owing to Short‐Term Pacing‐Induced Atrial Fibrillation in Horses
Authors: De Clercq D. , Van Loon G. , Tavernier R. , Duchateau L. , Deprez Piet
Published: January 2009

Background: In humans, atrial fibrillation (AF) induces electrical, contractile, and structural remodeling leading to AF stabilization. Little is known about AF‐induced atrial remodeling in horses.

Hypothesis: Induced AF produces rapid atrial electrical and contractile remodeling in horses.

Animals: Six horses, 5 animals completed the study.

Methods: Each horse was instrumented with a pulse generator and pacemaker to maintain AF by burst pacing and to study atrial and ventricular electrophysiology (AF cycle length [AFCL], AF duration, and atrial/ventricular effective refractory period [AERP/VERP] at different pacing cycle lengths [PCL]). Left atrial and ventricular contractile remodeling were assessed echocardiographically by calculation of fractional changes in atrial and ventricular dimensions, respectively, during the cardiac cycle. Measurements were performed at baseline, a 7‐day AF period and a 2‐day recovery period.

Results: Atrial electrical and contractile remodeling could be demonstrated after 4 and 12 hours of AF, respectively. A progressive shortening of the AERP (261 ± 39–171 ± 18 ms at a PCL of 1,000 ms, P < .0001), an attenuation of the AERP rate adaptation, a decrease in AFCL (239 ± 39–194 ± 7 ms, P < .0001), and a decrease in atrial FS (12 ± 3% to 0 ± 2%, P < .05) occurred. AF duration increased progressively and became persistent in 2 animals. VERP did not change significantly. Upon restoration of sinus rhythm, values returned to baseline within 48 hours.

Conclusions and Clinical Importance: Atrial electrical and contractile remodeling appears rapidly. After 7 days of AF, reverse remodeling occurred within 2 days. These observations suggest that early conversion of AF might be beneficial for success rate and early return to training.
The Cardiac Sodium‐Calcium Exchanger Gene (NCX‐1) is a Potential Canine Cardiac Biomarker of Chronic Mitral Valvular Insufficiency
Authors: Moon H.‐S. , Choi E. , Hyun C.
Published: January 2009

Background: The cardiac sodium‐calcium exchanger gene (NCX‐1) is upregulated in humans and mice with congestive heart failure (CHF).

Hypothesis: NCX‐1 expression is upregulated in dogs with heart failure from chronic mitral valvular insufficiency (CMVI).

Animals: Client‐owned 14 healthy control dogs and 30 dogs with CMVI.

Methods: Prospective, controlled, observational study. We investigated the levels of NCX‐1 expression in dogs at different stages of CMVI with real‐time reverse transcription polymerase chain reaction.

Results: The mRNA expression levels of NCX‐1 were determined in peripheral blood samples obtained from the animals used in this study. Dogs were graded by the severity of disease. The fold differences in the levels of mRNA expression compared with controls were 1.39 ± 0.88 (group I), 1.32 ± 0.65 (group II), 4.86 ± 1.25 (group III), and 5.96 ± 1.69 (group IV). NCX‐1 expression was significantly higher in groups III and IV (P < .05) compared with the healthy controls, whereas groups I and II were not.

Conclusions and Clinical Importance: The level of NCX‐1 expression was significantly higher in groups of dogs with moderate to severe CMVI (groups III and IV) compared with the controls. Our findings indicate that NCX‐1 can be a biomarker for chronic valvular disease in dogs and is a potential biomarker for severity of heart disease.
Membrane Fusion: Grappling with SNARE and SM Proteins
Authors: Südhof Thomas C. , Rothman James E.
Published: January 2009

The two universally required components of the intracellular membrane fusion machinery, SNARE and SM (Sec1/Munc18-like) proteins, play complementary roles in fusion. Vesicular and target membrane–localized SNARE proteins zipper up into an α-helical bundle that pulls the two membranes tightly together to exert the force required for fusion. SM proteins, shaped like clasps, bind to trans-SNARE complexes to direct their fusogenic action. Individual fusion reactions are executed by distinct combinations of SNARE and SM proteins to ensure specificity, and are controlled by regulators that embed the SM-SNARE fusion machinery into a physiological context. This regulation is spectacularly apparent in the exquisite speed and precision of synaptic exocytosis, where synaptotagmin (the calcium-ion sensor for fusion) cooperates with complexin (the clamp activator) to control the precisely timed release of neurotransmitters that initiates synaptic transmission and underlies brain function.
Brown Clouds over South Asia: Biomass or Fossil Fuel Combustion?
Authors: Gustafsson Örjan , Kruså Martin , Zencak Zdenek , Sheesley Rebecca J. , Granat Lennart , Engström Erik , Praveen P. S. , Rao P. S. P. , Leck Caroline , Rodhe Henning
Published: January 2009

Carbonaceous aerosols cause strong atmospheric heating and large surface cooling that is as important to South Asian climate forcing as greenhouse gases, yet the aerosol sources are poorly understood. Emission inventory models suggest that biofuel burning accounts for 50 to 90% of emissions, whereas the elemental composition of ambient aerosols points to fossil fuel combustion. We used radiocarbon measurements of winter monsoon aerosols from western India and the Indian Ocean to determine that biomass combustion produced two-thirds of the bulk carbonaceous aerosols, as well as one-half and two-thirds of two black carbon subfractions, respectively. These constraints show that both biomass combustion (such as residential cooking and agricultural burning) and fossil fuel combustion should be targeted to mitigate climate effects and improve air quality.
Widespread Increase of Tree Mortality Rates in the Western United States
Authors: van Mantgem Phillip J. , Stephenson Nathan L. , Byrne John C. , Daniels Lori D. , Franklin Jerry F. , Fulé Peter Z. , Harmon Mark E. , Larson Andrew J. , Smith Jeremy M. , Taylor Alan H. , Veblen Thomas T.
Published: January 2009

Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17 to 29 years among regions. Increases were also pervasive across elevations, tree sizes, dominant genera, and past fire histories. Forest density and basal area declined slightly, which suggests that increasing mortality was not caused by endogenous increases in competition. Because mortality increased in small trees, the overall increase in mortality rates cannot be attributed solely to aging of large trees. Regional warming and consequent increases in water deficits are likely contributors to the increases in tree mortality rates.
The Peopling of the Pacific from a Bacterial Perspective
Authors: Moodley Yoshan , Linz Bodo , Yamaoka Yoshio , Windsor Helen M. , Breurec Sebastien , Wu Jeng-Yih , Maady Ayas , Bernhöft Steffie , Thiberge Jean-Michel , Phuanukoonnon Suparat , Jobb Gangolf , Siba Peter , Graham David Y. , Marshall Barry J. , Achtman Mark
Published: January 2009

Two prehistoric migrations peopled the Pacific. One reached New Guinea and Australia, and a second, more recent, migration extended through Melanesia and from there to the Polynesian islands. These migrations were accompanied by two distinct populations of the specific human pathogen
Helicobacter pylori
, called hpSahul and hspMaori, respectively. hpSahul split from Asian populations of
H. pylori
31,000 to 37,000 years ago, in concordance with archaeological history. The hpSahul populations in New Guinea and Australia have diverged sufficiently to indicate that they have remained isolated for the past 23,000 to 32,000 years. The second human expansion from Taiwan 5000 years ago dispersed one of several subgroups of the Austronesian language family along with one of several hspMaori clades into Melanesia and Polynesia, where both language and parasite have continued to diverge.
Secondary Replicative Function of CD8
+
T Cells That Had Developed an Effector Phenotype
Authors: Bannard Oliver , Kraman Matthew , Fearon Douglas T.
Published: January 2009

Models of the differentiation of memory CD8
+
T cells that replicate during secondary infections differ over whether such cells had acquired effector function during primary infections. We created a transgenic mouse line that permits mapping of the fate of granzyme B (gzmB)–expressing CD8
+
T cells and their progeny by indelibly marking them with enhanced yellow fluorescent protein (EYFP). Virus-specific CD8
+
T cells express gzmB within the first 2 days of a primary response to infection with influenza, without impairment of continued primary clonal expansion. On secondary infection, virus-specific CD8
+
T cells that became EYFP
+
during a primary infection clonally expand as well as all virus-specific CD8
+
T cells. Thus, CD8
+
T cells that have acquired an effector phenotype during primary infection may function as memory cells with replicative function.
Quantum Teleportation Between Distant Matter Qubits
Authors: Olmschenk S. , Matsukevich D. N. , Maunz P. , Hayes D. , Duan L.-M. , Monroe C.
Published: January 2009

Quantum teleportation is the faithful transfer of quantum states between systems, relying on the prior establishment of entanglement and using only classical communication during the transmission. We report teleportation of quantum information between atomic quantum memories separated by about 1 meter. A quantum bit stored in a single trapped ytterbium ion (Yb
+
) is teleported to a second Yb
+
atom with an average fidelity of 90% over a replete set of states. The teleportation protocol is based on the heralded entanglement of the atoms through interference and detection of photons emitted from each atom and guided through optical fibers. This scheme may be used for scalable quantum computation and quantum communication.
Plasmodium falciparum pfmdr1
Amplification, Mefloquine Resistance, and Parasite Fitness
Authors: Preechapornkul Piyanuch , Imwong Mallika , Chotivanich Kesinee , Pongtavornpinyo Wirichada , Dondorp Arjen M. , Day Nicholas P. J. , White Nicholas J. , Pukrittayakamee Sasithon
Published: January 2009

Mefloquine is widely used in combination with artemisinin derivatives for the treatment of falciparum malaria. Mefloquine resistance in
Plasmodium falciparum
has been related to increased copy numbers of multidrug-resistant gene 1 (
pfmdr1
). We studied the ex vivo dynamics of
pfmdr1
gene amplification in culture-adapted
P. falciparum
in relation to mefloquine resistance and parasite fitness. A Thai
P. falciparum
isolate (isolate TM036) was assessed by the use of multiple genetic markers as a single genotype. Resistance was selected by exposure to stepwise increasing concentrations of mefloquine up to 30 ng/ml in continuous culture. The
pfmdr1
gene copy numbers increased as susceptibility to mefloquine declined (
P
= 0.03). No codon mutations at positions 86, 184, 1034, 1042, and 1246 in the
pfmdr1
gene were detected. Two subclones of selected parasites (average copy numbers, 2.3 and 3.1, respectively) showed a fitness disadvantage when they were grown together with the original parasites containing a single
pfmdr1
gene copy in the absence of mefloquine; the multiplication rates were 6.3% and 8.7% lower, respectively (
P
< 0.01). Modeling of the dynamics of the
pfmdr1
copy numbers over time in relation to the relative fitness of the parasites suggested that net
pfmdr1
gene amplification from one to two copies occurs once in every 10
8
parasites and that amplification from two to three copies occurs once in every 10
3
parasites.
pfmdr1
gene amplification in
P. falciparum
is a frequent event and confers mefloquine resistance. Parasites with multiple copies of the
pfmdr1
gene have decreased survival fitness in the absence of drug pressure.