Infrared thermography as a diagnostic tool to detect cranial cruciate ligament deficiency in dogs.

Cranial cruciate ligament (CCL) disease is the leading cause of canine lameness. Diagnosis is based on physical examination and diagnostic imaging findings. Limitations of diagnostic modalities, including patient temperament, cost, availability, and need for general anesthesia, preclude their use for many patients. Infrared thermography is an easy, non-invasive diagnostic screening technique with use in both human and veterinary musculoskeletal conditions. The objective of this study was to investigate the utility of infrared thermography to diagnose CCL disease in a large population of client-owned dogs and investigate for correlations between ability of thermography to diagnose CCL deficiency and recorded explanatory factors. A commercial grade thermal imaging camera was used to collect preoperative images of both stifles in 50 dogs with surgically confirmed CCL rupture in one stifle and a normal opposite stifle. The average maximum temperatures of the affected and unaffected stifles were collected from these images and used for statistical analysis. Infrared thermography was not successful in differentiating between CCL-deficient and unaffected stifles in this cohort. No significant differences in average maximal temperature were observed between stifles when comparing to explanatory factors or variables. Use of infrared thermography should not be relied upon to diagnose canine CCL disease.

La pathologie du ligament croisé crânien (CCL) est la principale cause de boiterie canine. Le diagnostic repose sur l'examen physique et les résultats de l'imagerie diagnostique. Les limites des modalités de diagnostic, y compris le tempérament du patient, le coût, la disponibilité et la nécessité d'une anesthésie générale, empêchent leur utilisation pour de nombreux patients. La thermographie infrarouge est une technique de dépistage diagnostique simple et non invasive, utilisable dans les conditions musculosquelettiques humaines et vétérinaires. L'objectif de cette étude était d'étudier l'utilité de la thermographie infrarouge pour diagnostiquer les problèmes de CCL dans une grande population de chiens appartenant à des clients et d'étudier les corrélations entre la capacité de la thermographie à diagnostiquer une déficience du CCL et les facteurs explicatifs enregistrés. Une caméra d'imagerie thermique de qualité commerciale a été utilisée pour collecter des images préopératoires des deux grassets chez 50 chiens avec une rupture du CCL confirmée chirurgicalement dans un grasset et un grasset opposé normal. Les températures maximales moyennes des grassets affectés et non affectés ont été recueillies à partir de ces images et utilisées pour l'analyse statistique. La thermographie infrarouge n'a pas réussi à différencier les grassets avec atteintes du CCL des grassets non affectés dans cette cohorte. Aucune différence significative dans la température maximale moyenne n'a été observée entre les grassets lors de la comparaison avec des facteurs ou variables explicatifs. L'utilisation de la thermographie infrarouge ne doit pas être utilisée pour diagnostiquer les pathologie du CCL canin.(Traduit par Docteur Serge Messier).

The full spectrum tuning of fluorescent molecules via a one-pot multicomponent reaction.

Fluorogenic probes for imaging enable visualization and analysis of difficult-to-reach cells and organelles. However, there are limited efficient examples of tuning these fluorescent molecules to higher wavelengths. This is vital since different tissues are sensitive to varying wavelength emissions. To address this need, we report the discovery, tuning, structure-photophysical property relationships (SPPR), and time-dependent DFT (TD-DFT) computations of 400-700+ nm fluorescent pyrido[2',1':2,3]imidazo[4,5-c]isoquinolines and substituted imidazo[1,2-a]pyridin-3-amines. The syntheses involve the trimethylsilylcyanide (TMSCN) modified Groebke-Blackburn-Bienaymé (GBB) multicomponent reaction as well as the TMSCN modified GBB combined with subsequent condensation of an aldehyde, and Aza-Friedel-Crafts-Intramolecular Cyclization-Oxidation all in one pot. The SPPR reveals that electron-withdrawing strength in the para-position of the aminopyridine starting material has direct control over the absorption and fluorescence emission wavelengths of these molecules. The TD-DFT computations show the changes in the natural transition orbitals (NTOs) with differing substitutions to the parent molecule that dictate the observed excitations, emissions, and fluorescence intensities. These findings give insights and directions for tuning the fluorescent properties of these motifs for various uses as probes and imaging agents.

Protein Modification via Mild Photochemical Isomerization of Triazenes to Release Aryl Diazonium Ions.

This work describes the development of phenyl diazenyl piperidine triazene derivatives that can be activated to release aryl diazonium ions for labeling of proteins using light. These probes show marked bench stability at room temperature and can be photoisomerized via low-intensity UVA irradiation at physiological pH. Upon isomerization, the triazenes are rendered more basic and readily protonate to release reactive aryl diazonium ions. It was discovered that the intensity and duration of the UV light was essential to the observed diazonium ion reactivity in competition with the traditionally observed photolytic radical pathways. The combination of their synthetic efficiency coupled with their overall stability makes triazenes an attractive candidate for use in bioconjugation applications. Bioorthogonal handles on the triazenes are used to demonstrate the ease by which proteins can be modified.

Sequential Knoevenagel [4+1] Cycloaddition-Condensation-Aza-Friedel-Crafts Intramolecular Cyclization: A 4-Center-3-Component Reaction Toward Tunable Fluorescent Indolizine Tetracycles.

A two-step multicomponent reaction oxidation protocol is reported herein, which affords novel tunable fluorescent tetracyclic indolizines. The procedure involves a novel 4-center-3-component reaction, which proceeds via a sequential Knoevenagel condensation, [4+1] cycloaddition, and imine condensation to afford imino-indolizines. Products then undergo cyclization and are oxidized in situ to afford fluorescent tetracycles, which are readily tunable through modification of diversity elements.

Copper-Free Click Enabled Triazabutadiene for Bioorthogonal Protein Functionalization.

Aryl diazonium ions have long been used in bioconjugation due to their reactivity toward electron-rich aryl residues, such as tyrosine. However, their utility in biological systems has been restricted due to the requirement of harsh conditions for their generation in situ, as well as limited hydrolytic stability. Previous work describing a scaffold known as triazabutadiene (TBD) has shown the ability to protect aryl diazonium ions allowing for increased synthetic utility, as well as triggered release under biologically relevant conditions. Herein, we describe the synthesis and application of a novel TBD, capable of installation of a cyclooctyne on protein surfaces for later use of copper-free click reactions involving functional azides. The probe shows efficient protein labeling across a wide pH range that can be accomplished in a convenient and timely manner. Orthogonality of the cyclooctyne modification was showcased by labeling a model protein in the presence of hen egg proteins, using an azide-containing fluorophore. We further confirmed that the azobenzene modification can be cleaved using sodium dithionite treatment.

Highly Stable Meldrum's Acid Derivatives for Irreversible Aqueous Covalent Modification of Amines.

This work describes the development of a highly stable and pH-responsive probe for lysine modification. The scaffold has marked stability in the presence of several biological nucleophiles and across a wide pH range (2-12). Several functional analogs showed robust labeling of a protein at pH > 9. Taken together, our system displays versatility and can be easily adapted for variety of applications, while demonstrating stability suitable for a wide range of biologically compatible systems.

Effects of a surgical checklist on decreasing incisional infections following foreign body removal from the gastrointestinal tract in dogs.

Two similar populations of dogs were evaluated in either a retrospective or prospective manner for 2 weeks after gastrointestinal foreign body surgery to determine the impact of a surgical checklist on the surgical site infection (SSI) rate. The medical records of 201 gastrointestinal foreign body surgeries were reviewed to determine the SSI rate without the use of a surgical checklist (SC-) and 101 consecutive gastrointestinal foreign body surgeries were performed using a surgical checklist (SC+). The SSI rate had a significant decrease from 19.9% to 11.9% with the use of the surgical checklist. When combining the cohorts, statistically significant predictors for development of an SSI following gastrointestinal foreign body removal included: a combined gastrotomy and enterotomy, an enterotomy, and known self-trauma.

Effets d'une liste de contrôle chirurgicale sur la réduction des infections des incisions après l'enlèvement d'un corps étranger dans le tube digestif des chiens. Deux populations semblables de chiens ont été évaluées, soit d'une manière rétrospective ou prospective, pendant 2 semaines après la chirurgie pour l'enlèvement d'un corps étranger afin de déterminer l'impact d'une liste de contrôle chirurgicale sur le taux d'infection du site chirurgical. Les dossiers médicaux de 201 chirurgies pour des corps étrangers gastro-intestinaux ont été examinés afin de déterminer le taux d'infection du site chirurgical sans le recours à une liste de contrôle chirurgicale et 101 chirurgies consécutives pour l'enlèvement d'un corps étranger ont été réalisées en utilisation une liste chirurgicale. Le taux d'infection du site chirurgical a connu une baisse significative de 19,9 % à 11,9 % avec le recours à une liste de contrôle chirurgicale. Lors de la combinaison des cohortes, les prédicteurs ayant une signification statistique pour le développement d'une infection au site chirurgical après l'enlèvement d'un corps étranger dans le tube digestif incluaient notamment : une gastrotomie et une entérotomie combinée, une entérotomie et un traumatisme auto-infligé connu.(Traduit par Isabelle Vallières).

Coumarin Triazabutadienes for Fluorescent Labeling of Proteins.

The use of small-molecule fluorophores to label proteins with minimal perturbation in response to an external stimulus is a powerful tool to probe chemical and biochemical environments. Herein, we describe the use of a coumarin-modified triazabutadiene that can deliver aryl diazonium ions to fluorescently label proteins by tyrosine-selective modification. The labeling can be triggered by low-pH-induced liberation of the diazonium species, thus making the fluorophore especially useful in labeling biochemical surroundings such as those found within the late endosome. Additionally, we show that a variety of coumarin triazabutadienes might also be prone to releasing their diazonium cargo after irradiation with UV light.

Outcome and Prognostic Indicators in Cats Undergoing Splenectomy for Splenic Mast Cell Tumors.

This was a multi-institutional retrospective study evaluating the outcome and clinical parameters associated with the postoperative prognosis of 36 cats with splenic mast cell tumors treated with splenectomy. Clinical parameters reviewed included signalment, clinical history, results of staging tests, surgical variables, administration of blood products, presence of metastasis, postoperative complications, administration of chemotherapy postoperatively, chemotherapy protocol, and response to chemotherapy. Overall median survival time was 390 days (range, 2-1737 days). Administration of a blood product (P < .0001), metastasis to a regional lymph node (P = .022), and evidence of either concurrent or historical neoplasia (P = .037) were negatively associated with survival. Response to chemotherapy (P = .0008) was associated with an improved median survival time. Larger-scale prospective studies evaluating different chemotherapy protocols are required to elucidate the discrepancy between lack of survival benefit with administration of chemotherapy and improvement in survival time with positive response to chemotherapy.

Evaluation of data from 35 dogs pertaining to dehiscence following intestinal resection and anastomosis.

The objectives of this study were to evaluate blood and abdominal fluid lactate and glucose, fluid cytology, culture, and volume 24 and 48 hr following intestinal resection and anastomosis in dogs with and without closed-suction drains and to correlate findings with survival. Thirty-five client-owned dogs that underwent intestinal resection and anastomosis were prospectively enrolled in the study. Abdominal fluid was submitted for culture at surgery and again 24 hr postoperatively. Twenty-four and 48 hr postoperatively, blood and abdominal fluid glucose and lactate were measured and fluid was submitted for cytology. Abdominal fluid was collected either from a closed-suction drain or by abdominocentesis. Patients were followed either for 14 days or until death. Comparisons were made based on development of dehiscence and presence or absence of a drain. Patients with dehiscence were more likely to have positive cultures at 24 hr and to have had more bowel resected. Surviving patients without drains had significantly smaller differences in blood and fluid glucose and lactate both 24 and 48 hr postoperatively than surviving patients with drains. The significant differences identified between patients with and without drains suggests a need for further research into the effect of drains on abdominal fluid values.

Evaluation of the prevalence of urinary incontinence in spayed female dogs: 566 cases (2003-2008).

OBJECTIVE: To determine the prevalence of urinary incontinence in spayed female dogs and categorize affected dogs by age at time of ovariohysterectomy, number of litters prior to ovariohysterectomy, body weight, treatment of affected dogs, and severity of incontinence and to determine associations among these variables. DESIGN: Retrospective case series. ANIMALS: 566 ovariohysterectomized dogs. PROCEDURES: An attempt was made to contact owners of 912 dogs ovariohysterectomized between January 2003 and January 2008 to discuss presence or absence of urinary incontinence. The actual number of responders was 566. Those owners with incontinent pets received a questionnaire further assessing degree of incontinence, diagnostic testing, treatment, and history. RESULTS: The prevalence of acquired urinary incontinence was determined to be 5.12% (29/566 dogs) on the basis of results of phone surveys and questionnaires. There was no significant difference in the age at time of ovariohysterectomy between incontinent and continent groups. A significant association was found between body weight and incontinence, with incontinence rates higher among larger (≥ 15 kg [33.1 lb]) dogs. Larger dogs were approximately 7 times as likely (OR, 7.2 [95% confidence interval, 2.5 to 21.1]) to develop acquired urinary incontinence, compared with small dogs (< 15 kg). CONCLUSIONS AND CLINICAL RELEVANCE: Although acquired urinary incontinence in female dogs is known to be associated with ovariohysterectomy, the prevalence in this study was low.

Diagnosis of erythema multiforme associated with thymoma in a dog and treated with thymectomy.

A 7 yr old Labrador retriever initially presented for severe halitosis, mild ptylism, and depigmentation of the nasal planum. Erythema multiforme was diagnosed based on clinical signs and dermatopathology. Treatment was initiated but the condition did not resolve. Six months later, the dog was diagnosed with a mediastinal mass. Trucut biopsy was performed and histopathologic diagnosis was consistent with a thymoma. A median sternotomy was performed, the thymoma was excised, and the dog recovered well. Four months postoperatively, there were no longer any obvious erythema multiforme lesions and the skin condition was controlled without medication. Erythema multiforme may be a paraneoplastic disorder associated with thymoma in the dog, similar to thymoma-associated exfoliative dermatitis in the cat. Clinical signs of erythema multiforme may warrant performing thoracic radiographs or thoracic CT to rule out thymoma as an underlying cause.

Adrenal pheochromocytoma with contralateral adrenocortical adenoma in a cat.

A 7-year-old, neutered male cat was presented with a 6-month history of progressive polyuria, polydipsia, polyphagia, aggression, and weight gain. Previous blood work, urinalysis, and radiographs did not delineate a cause for the clinical signs. An ultrasound revealed bilateral adrenal gland enlargement. A low-dose dexamethasone suppression test was consistent with hyperadrenocorticism. Based on these findings, bilateral adrenalectomy was attempted and successfully performed. Histopathology was consistent with a cortical adenoma in the right adrenal gland and a pheochromocytoma in the left adrenal gland. This association has never been reported in the cat.

Outcome of and prognostic indicators for dogs and cats with pneumoperitoneum and no history of penetrating trauma: 54 cases (1988-2002).

OBJECTIVE: To determine the outcome of and prognostic indicators for dogs and cats with pneumoperitoneum and no history of penetrating trauma. DESIGN: Retrospective study. ANIMALS: 43 dogs and 11 cats. PROCEDURE: Medical records of dogs and cats with radiographic evidence of pneumoperitoneum and no history of penetrating trauma were reviewed. Information collected included signalment, previous medical problems, initial complaint, duration of illness, physical examination findings, radiographic findings, laboratory abnormalities, abdominocentesis results, bacterial culture results, concurrent diseases, hospitalization time, and outcome. Abdominal radiographs were reviewed, and radiographic severity of pneumoperitoneum was classified. For those animals that underwent exploratory laparotomy, time from admission to surgery and results of histologic examination of biopsy specimens were recorded. RESULTS: 24 (44%) animals survived and were discharged from the hospital, but none of the variables examined was associated with whether animals survived. Rupture of the gastrointestinal tract was the cause of pneumoperitoneum in 40 animals. However, cause and location of gastrointestinal tract rupture was not associated with whether animals survived. Twenty-three of 40 (58%) animals that underwent exploratory laparotomy survived, compared with only 1 of 14 animals that did not undergo surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that pneumoperitoneum in dogs and cats without any history of penetrating trauma is most commonly associated with rupture of the gastrointestinal tract and requires immediate surgical intervention. Even when appropriate treatment is instituted, the shortterm prognosis is only fair.

Prognostic indicators for time to ambulation after surgical decompression in nonambulatory dogs with acute thoracolumbar disk extrusions: 112 cases.

OBJECTIVES: To determine prognostic indicators for time to ambulation after surgical decompression in nonambulatory dogs with intact pain sensation and acute Hansen type-1 disk extrusions. STUDY DESIGN: Retrospective clinical study. ANIMALS: One-hundred twelve dogs with Hansen type-I disk extrusions that had decompressive hemilaminectomy or dorsal laminectomy. METHODS: All dogs had thoracolumbar disk extrusion and were nonambulatory with intact pain sensation at admission. Variables considered included age, weight, voluntary motor function at time of anesthetic induction, glucocorticoid use, times from onset of nonambulatory status to admission and surgical decompression, time in hospital to surgical decompression, anesthetic time, surgical time, number of contrast injections required to perform a diagnostic myelogram, postoperative pain sensation, and postoperative voluntary motor function. Time to ambulation was defined as the number of days from surgical decompression until the dog was able to stand and take a series of steps without assistance. RESULTS: One-hundred seven dogs (96%) were able to ambulate within 3 months. The mean time to ambulation was 12.9 days and was significantly shorter if dogs had postoperative voluntary motor function (7.9 days v 16.4 days, P <.0001). No other variable had a significant association with time to ambulation. CONCLUSIONS: Few perioperative variables have prognostic value for return to ambulation. Nonambulatory dogs with intact pain sensation and Hansen type-1 disk extrusions in the thoracolumbar spine that are treated with surgical decompression have a favorable prognosis. CLINICAL RELEVANCE: The presence of postoperative voluntary motor function is a favorable prognostic indicator for early return to ambulation.

Comparison of radiography, computed tomography, and magnetic resonance imaging for evaluation of appendicular osteosarcoma in dogs.

OBJECTIVE: To determine which imaging modality best determines the microscopic extent of primary appendicular osteosarcoma in amputated limbs in dogs. DESIGN: Case series. ANIMALS: 10 dogs with appendicular osteosarcoma. PROCEDURE: 10 dogs with appendicular osteosarcoma that did not receive neoadjuvent chemotherapy were treated by use of limb amputation. Amputated limbs were imaged by use of radiography, computed tomography (CT), and magnetic resonance imaging (MRI) and examined microscopically to determine longitudinal extent of neoplastic cell involvement and length of associated intramedullary fibrosis. Changes detected by use of the various imaging studies were compared with the actual tumor length determined microscopically. Data were analyzed to determine which imaging technique most closely predicted tumor length. RESULTS: Measurements obtained by use of craniocaudal radiographic views were most accurate at predicting tumor length but underestimated tumor length substantially in 1 limb and slightly in another limb. Measurements made by use of CT were most accurate at predicting tumor length when intramedullary fibrosis was taken into account but underestimated tumor length in 1 limb. Measurements made by use of MRI were least accurate but did not underestimate tumor length in any of the limbs. CONCLUSIONS AND CLINICAL RELEVANCE: Although radiography is used in diagnosis of osteosarcoma in dogs, additional imaging studies to confirm the extent of neoplasia prior to limb-sparing ostectomy may be beneficial. Underestimation of tumor length would be associated with higher incidence of incomplete excision and local tumor recurrence.