Multicenter molecular investigation of recurrent Escherichia coli bacteriuria in dogs.

Escherichia coli is the most common cause of recurrent urinary tract infection (UTI) in dogs. UTI recurrence comprises of persistent, unresolved E. coli infection or reinfection with a different strain of E. coli. Differentiating between these processes is clinically important but is often impossible with routine diagnostics. We tested the hypothesis that most recurrent canine E. coli bacteriuria is due to recurrence of the same E. coli strain involved in the initial infection. Molecular typing was performed on 98 urinary E. coli isolated from dogs with recurrent bacteriuria from five veterinary diagnostic laboratories in the United States. Of the 42 dogs in this study with multiple E. coli bacteriuria observations, a single strain of E. coli caused recurrent bacteriuria in 26 (62 %) dogs, in some cases on multiple occasions for prolonged periods of time (up to eight months). A single E. coli strain was detected during both subclinical bacteriuria and clinically-apparent UTI in three dogs. Isolates with the P-fimbrial adhesin genes papA and papC were associated with recurrence by the same strain of E. coli. Multiple isolations of a single strain of E. coli associated with recurrent bacteriuria suggests that E. coli may be maintained within the urinary tract of some dogs for prolonged periods of time. In some patients, the same strain can cause both clinical UTI and subclinical bacteriuria. This indicates that in dogs, the urinary bladder may serve as a subclinical, long-term reservoir of E. coli that may cause clinical UTI in the future.

Ionized calcium-to-phosphorus ratio predicts neoplasia in azotemic dogs: a retrospective study of 105 cases.

OBJECTIVE: To evaluate dogs with total hypercalcemia, azotemia, and normal serum phosphorus concentrations to determine whether a calcium-to-phosphorus ratio (Ca:P) or ionized Ca:P (iCa:P) could be utilized to predict underlying neoplasia. ANIMALS: 105 dogs were included in the study. Thirty-seven percent (n = 39) had known neoplasia, and 63% (66) had no evidence of neoplasia. PROCEDURES: A retrospective medical records search was performed. An observational cutoff of 2.5 for Ca:P and 0.33 for iCa:P was used for determining sensitivity and specificity between the neoplasia and nonneoplasia groups. RESULTS: Total hypercalcemia was higher in dogs with neoplasia compared to nonneoplastic cases of hypercalcemia. Ca:P of 2.5 had an 80% sensitivity and 46% specificity for predicting neoplasia. iCa:P of 0.33 had a 92% sensitivity and 77% specificity for predicting neoplasia in azotemic dogs. CLINICAL RELEVANCE: The sensitivity and specificity of Ca:P was low, making it an unreliable tool to predict neoplasia in this specific study population. However, iCa:P may have some usefulness in determining presence of neoplasia in patients with high calcium, azotemia, and normal phosphorus.

Comparative whole transcriptome analysis of gene expression in three canine soft tissue sarcoma types.

Soft tissue sarcomas are pleiotropic tumors of mesenchymal cell origin. These tumors are rare in humans but common in veterinary practice, where they comprise up to 15% of canine skin and subcutaneous cancers. Because they present similar morphologies, primary sites, and growth characteristics, they are treated similarly, generally by surgical resection followed by radiation therapy. Previous studies have examined a variety of genetic changes as potential drivers of tumorigenesis and progression in soft tissue sarcomas as well as their use as markers for soft tissue sarcoma subtypes. However, few studies employing next generation sequencing approaches have been published. Here, we have examined gene expression patterns in canine soft tissue sarcomas using RNA-seq analysis of samples obtained from archived formalin-fixed and paraffin-embedded tumors. We provide a computational framework for using resulting data to categorize tumors, perform cross species comparisons and identify genetic changes associated with tumorigenesis. Functional overrepresentation analysis of differentially expressed genes further implicate both common and tumor-type specific transcription factors as potential mediators of tumorigenesis and aggression. Implications for tumor-type specific therapies are discussed. Our results illustrate the potential utility of this approach for the discovery of new therapeutic approaches to the management of canine soft tissue sarcomas and support the view that both common and tumor-type specific mechanisms drive the development of these tumors.

Development of prednisone resistance in naïve canine lymphoma: Longitudinal evaluation of NR3C1α, ABCB1, and 11ß-HSD mRNA expression.

Prednisone resistance develops rapidly and essentially universally when dogs with lymphoma are treated with corticosteroids. We investigated naturally occurring mechanisms of prednisone resistance in seven dogs with naïve multicentric lymphoma, treated with oral prednisone; four dogs were administered concurrent cytotoxic chemotherapy. Expression of NR3C1α, ABCB1 (formerly MDR1), 11ß-HSD1, and 11ß-HSD2 mRNA was evaluated in neoplastic lymph nodes by real-time RT-PCR. Changes of expression levels at diagnosis and at time of clinical resistance to prednisone were compared longitudinally using a Wilcoxon signed-rank test. Clinical resistance to prednisone was observed after a median of 68 days (range: 7-348 days) after initiation of treatment. Relative to pretreatment samples, prednisone resistance was associated with decreased NR3C1α expression in biopsies of all dogs with high-grade lymphoma (six dogs, p=.031); one dog with indolent T-zone lymphoma had increased expression of NR3C1α. Resistance was not consistently associated with changes in ABCB1, 11ß-HSD1, or 11ß-HSD2 expression. Decreased expression of the glucocorticoid receptor (NR3C1α) may play a role in conferring resistance to prednisone in dogs with lymphoma. Results do not indicate a broad role for changes in expression of ABCB1, 11ß-HSD1, and 11ß-HSD2 in the emergence of prednisone resistance in lymphoma-bearing dogs.

Molecular insights into the improved clinical performance of PEGylated interferon therapeutics: a molecular dynamics perspective.

PEGylation is a widely adopted process to covalently attach a polyethylene glycol (PEG) polymer to a protein drug for the purpose of optimizing drug clinical performance. While the outcomes of PEGylation in imparting pharmacological advantages have been examined through experimental studies, the underlying molecular mechanisms remain poorly understood. Using interferon (IFN) as a representative model system, we carried out comparative molecular dynamics (MD) simulations of free PEGx, apo-IFN, and PEGx-IFN (x = 50, 100, 200, 300) to characterize the molecular-level changes in IFN introduced by PEGylation. The simulations yielded molecular evidence directly linked to the improved protein stability, bioavailability, retention time, as well as the decrease in protein bioactivity with PEG conjugates. Our results indicate that there is a tradeoff between the benefits and costs of PEGylation. The optimal PEG chain length used in PEGylation needs to strike a good balance among the competing factors and maximizes the overall therapeutic efficacy of the protein drug. We anticipate the study will have a broad implication for protein drug design and development, and provide a unique computational approach in the context of optimizing PEGylated protein drug conjugates.

Hypoadrenocorticism mimicking protein-losing enteropathy in 4 dogs.

Four dogs referred for suspected protein-losing enteropathy based on clinical signs, severe hypoalbuminemia, and hypocholesterolemia, and in 2 dogs, abdominal effusion or peripheral edema, were diagnosed with hypoadrenocorticism. Dogs with hypoadrenocorticism may have features of protein-losing enteropathy, including ascites or peripheral edema, which have not been described in dogs with hypoadrenocorticism.

Hypoadrénocorticisme imitant l'entéropathie avec perte de protéines chez 4 chiens. Quatre chiens recommandés pour une entéropathie suspectée avec perte de protéines fondée sur les signes cliniques, accompagnée d'une hypoalbuméniémie grave et de l'hypocholestérolémie et, chez 2 chiens, d'une effusion abdominale ou d'un œdème périphérique, ont reçu un diagnostic d'hypoadrénocorticisme. Les chiens atteints d'hypoadrénocorticisme peuvent présenter des signes d'entéropathie avec perte de protéines, y compris de l'ascite ou de l'œdème périphérique, qui n'ont pas été décrits chez les chiens atteints d'hypoadrénocorticisme.(Traduit par Isabelle Vallières).

Bilateral mandibular pyogranulomatous lymphadenitis and pulmonary nodules in a dog with Bartonella henselae bacteremia.

This report describes a 2-year-old collie dog with pulmonary nodules, visualized by computed tomographic (CT) scan, with evidence of Bartonella henselae bacteremia and pyogranulomatous lymphadenitis. Clinical signs resolved with antimicrobial therapy.

Lymphadénite pyogranulomateuse mandibulaire latérale et nodules pulmonaires chez un chien atteint de bactériémie àBartonella henselae. Ce rapport décrit un chien Collie âgé de 2 ans atteint de nodules pulmonaires, visualisés par tomodensitométrie, avec des signes de bactériémie à Bartonella henselae et de lymphadénite pyogranulomateuse. Les signes cliniques se sont résorbés avec un traitement antimicrobien.(Traduit par Isabelle Vallières).

Systemic mycosis in three dogs from nonendemic regions.

Three dogs were examined for clinical signs ultimately attributed to systemic fungal infections. One dog was evaluated for chronic, ulcerated dermal lesions and lymphadenomegaly; one dog was examined for acute onset of unilateral blepharospasm; and one dog had diarrhea and hematochezia. Two of the dogs were diagnosed with blastomycosis (one with disseminated disease and the other with the disease localized to the left eye). The third dog was diagnosed with disseminated histoplasmosis. None of the dogs originated from, or had traveled to, typical regions endemic for these fungal diseases. All diagnoses were established from histopathology and either polymerase chain reaction (PCR) or cytology and culture. The two dogs diagnosed with blastomycosis were treated with either itraconazole or ketoconazole with apparent resolution of the infections. The dog with ocular involvement had an enucleation prior to beginning therapy. The dog diagnosed with histoplasmosis was euthanized without treatment. In patients with characteristic clinical features, systemic fungal infections should still be considered as differential diagnoses regardless of their travel history.

An expedited palliative radiation protocol for lytic or proliferative lesions of appendicular bone in dogs.

Fifty-eight dogs with lytic or proliferative bone lesions were treated with a radiation protocol of two 8-Gy fractions over 2 consecutive days. The protocol was well tolerated, with no increase in early or late effects over previously published protocols. Forty-three (91%) of 47 dogs responded positively to radiation, with a median time of 2 days to onset of pain relief. Median duration of pain relief was 67 days (range 12 to 503 days; mean 99+/-16 days). Median survival time for all dogs was 136 days (mean 179+/-18 days). Distal radial location was a positive prognostic indicator for survival (P=0.005).

The cholecystokinin type A receptor g.179A>G polymorphism affects feeding rate.

A polymorphism within the 5' untranslated region of the cholecystokinin type A receptor (CCKAR) gene has been shown to affect feed intake and growth in commercial pig lines. To further investigate the phenotype of animals carrying alternative alleles at this polymorphism, we genotyped animals from a distinct segregating commercial line and an experimental cross F(2) population, both with electronically recorded feeding pattern data. The data indicate that the daily feed intake increasing effect of the DQ496228:g.179G allele is mediated through a faster rate of feed intake, without evidence for an effect on other feeding behaviour traits.

A nine-day accelerated radiation protocol for feline squamous cell carcinoma.

Nine cats with oral squamous cell carcinoma were treated with an accelerated radiation protocol (14 fractions of 3.5 Gy in 9 days). Radiation was administered twice daily with a 6hour break between treatments. Median overall survival was 86 +/- 110 days. Median survival for cats with a partial response (n=6) was 60 +/- 7 days, while median survival for cats with a complete response (n=3) was 298 +/- 187 days (P = 0.0639). The accelerated protocol was well tolerated and toxicity in the early and late period was manageable in all cats. Further modification of the protocol is warranted to extend survival.

Plasma leptin levels are related to body composition, sex, insulin levels and the A55V polymorphism of the UCP2 gene.

OBJECTIVE: Circulating leptin levels show a high degree of individual variability even after the main effect of body fatness is accounted for. We therefore wanted to determine the roles of variation in body composition, age, sex and polymorphisms of the UCP2 gene and promoter region on levels of circulating leptin. SUBJECTS: One hundred and fifty Caucasian subjects, which represented a cross-section of the population from NE, Scotland, were recruited. MEASUREMENTS: Body composition was measured using dual X-ray absorptiometry. Fasted circulating leptin, insulin, T3 and T4 levels were measured, and all individuals were genotyped for the UCP2 polymorphisms A55V, -866G>A and exon-8 ins/del. RESULTS: The results indicate that circulating leptin was significantly related to sex and principle component (PC) scores representing overall adipose tissue mass and a second representing the contrast of central to peripheral bone mineral content. Residual leptin was associated with the A55V polymorphism (P< 0.001) explaining 11.3% of the residual variance. There was a marginal effect associated with exon-8 ins/del (P=0.045) explaining 4.4% of the residual variance in leptin. Log(e) transformed circulating fasting insulin was related to PC scores representing general adiposity and sex. Residual Log(e) insulin was associated with the A55V and exon-8 ins/del polymorphisms explaining 5.7% (P=0.015) and 5% (P=0.026) of the residual variation, respectively. The -866G>A polymorphism was not significantly associated with residual leptin or insulin. Leptin and insulin were significantly (P=0.007) correlated. Statistically removing the effect of insulin on leptin still showed association between leptin and A55V (P=0.002). Removing the effect of leptin on insulin, the A55V polymorphism was no longer significant (P=0.120). After accounting for the correlation between insulin and leptin, the exon-8 ins/del was no longer significant for residual leptin (P=0.119) or Log(e) insulin (P=0.252). CONCLUSION: These data suggest that the A55V polymorphism directly affected the levels of leptin but not via an effect on insulin.

Bone breaking strength and apparent metabolisability of calcium and phosphorus in selected and unselected broiler chicken genotypes.

1. The present study examined the bone strength and apparent mineral metabolisability of a selected broiler chicken compared with those of a relatively unselected genotype. 2. Selected (SB) and unselected genotypes (UB) were reared under standard conditions and were fed on either a high quality (HQ) or a low quality (LQ) diet. Tibiotarsi samples were collected at 42 d from SB and compared to tibiotarsi from UB of the same age and the same body mass (BM). 3. Bones were assessed for: bone breaking strength (BBS), morphology (weight and length), and both organic (OM) and inorganic content (ASH). Apparent dry matter digestibility and the coefficient of apparent metabolisability of calcium and phosphorus were determined at the same BM. 4. The BBS of SB (214 +/- 9 N) was greater than that of same-age UB (119 +/- 8 N) but the same as that of same-BM UB (218 +/- 10 N). At the same age, the SB had stronger, heavier bones with more ash and organic matter per unit length of tibiotarsus than UB. At the same BM, the tibiotarsi of the SB were shorter and lighter, with a higher ash and a similar organic content than the bones of the UB. At the same BM, BBS was about 15% lower in both genotypes fed on the LQ compared to the HQ diet. 5. The coefficients of apparent metabolisability of calcium and phosphorus were the same in both genotypes when fed on the HQ diet, but were lower in the SB than in the UB genotype when the birds were given the LQ diet. 6. The tibiotarsi of the selected broilers were stronger, or at least as strong, as those of the unselected broiler genotype, which may be due to similar levels of apparent calcium metabolisability of the selected chickens.

A polymorphism in the 5'-untranslated region of the porcine cholecystokinin type a receptor gene affects feed intake and growth.

The location and utilization of quantitative trait loci (QTL) and candidate genes with significant effects on economically important traits are becoming increasingly important in livestock breeding programs. The porcine cholecystokinin type A receptor (CCKAR) is a candidate gene for performance traits, due to its known role in the physiological control of feed intake, satiety, and obesity. We investigated the association of CCKAR polymorphisms with feeding, growth, and efficiency traits in an F2 population derived from a cross between Meishan and Large White founder animals and in lines of Large White pigs that had been divergently selected on the basis of lean growth efficiency traits. In the F2 population, CCKAR genotype was significantly associated with daily feed intake and average daily gain. The effects of the polymorphisms were then assessed in a larger-scale analysis of segregating commercial lines. A newly discovered single-nucleotide polymorphism (SNP) within the 5'-untranslated region (5'-UTR) had highly significant effects on feed intake, average daily gain, and days to 110 kg, which were not seen for a previously reported SNP within the CCKAR gene. Furthermore, we provide evidence that the novel SNP disrupts the binding of the YY1 transcription factor, which raises the possibility that it is the causal variant. The 5'-UTR SNP could be utilized as a molecular genetic test for increased feed intake, faster lean growth, and reduced days to market weight in segregating commercial lines.

Additional anthropometric measures may improve the predictability of basal metabolic rate in adult subjects.

BACKGROUND: The most commonly used predictive equation for basal metabolic rate (BMR) is the Schofield equation, which only uses information on body weight, age and sex to derive the prediction. However, because body composition is a key influencing factor, there will be error in calculating an individual's basal requirements based on this prediction. OBJECTIVE: To investigate whether adding additional anthropometric measures to the standard measures can enhance the predictability of BMR and to cross-validate this within a separate subgroup. DESIGN: Cross-sectional study of 150 Caucasian adults from Scotland, with a body mass index range of 16.7-49.3 kg/m(2). All subjects underwent measurement of BMR, body composition, and 148 also had basic skinfold and circumference measures taken. The resultant equation was tested in a subgroup of 39 obese males. RESULTS: The average difference between the predicted (Schofield equation) and measured BMR was 502 kJ/day. There was a slight systematic bias in this error, with the Schofield equation underestimating the lowest values. The average discrepancy between predicted and actual BMR was reduced to 452 kJ/day, with the addition of fat mass, fat-free mass, an overall 10% improvement on the Schofield equation (P=0.054). Using an equation derived from principal components analysis of anthropometry measurements similarly decreased the difference to 458 kJ/day (P=0.039). Testing the equation in a separate group indicated a 33% improvement in predictability of BMR, compared to the Schofield equation. CONCLUSIONS: In the absence of detailed information on body composition, utilizing anthropometric data provides a useful alternative methodology to improve the predictability of BMR beyond that achieved from the standard Schofield prediction equation. This should be confirmed in more individuals, both within the obese and normal weight category.

A melanocortin-4 receptor (MC4R) polymorphism is associated with performance traits in divergently selected Large White pig populations.

The melanocortin-4 receptor (MC4R) has a vital role in the control of energy balance and the genetic basis of obesity. A polymorphism, which results in the replacement of aspartic acid with asparagine at position 298 of the porcine MC4R gene, within the seventh transmembrane domain, has previously been described. In the current study, allele frequencies for this Asp298Asn polymorphism were investigated in lines of Large White pigs which had been divergently selected for seven generations based on lean food conversion (LFC), lean growth with ad libitum feeding (LGA), lean growth with restricted feeding (LGS) and daily feed intake (DFI). The association of the Asp298Asn polymorphism with performance traits in these lines was assessed. The frequency of Asp298 was higher (P < 0.001) in the LFC high line (0.48) than the low line (0.00), while the frequency of Asn298 was higher (P < 0.01) in the LGA high line (0.22) than the low line (0.04). When analysed across all lines, the Asp298Asn polymorphism was significantly associated with ultrasonic backfat depth, average daily gain and daily feed intake (P < 0.05). Asp298 homozygous animals had mean values of 13.3 mm, 733 g and 1933 g for backfat, average daily gain and daily feed intake respectively, compared with 14.7 mm, 805 g and 2098 g for Asn298 homozygotes. Therefore, the data support a role for the MC4R Asp298Asn polymorphism in the genetic basis of economically important traits in Large White pigs.