Biomedical subjects

Shelly L Vaden

Publications and source records attributed to Shelly L Vaden.

12 recordsLinked to original sources

PubMed2005

Renal biopsy of dogs and cats.

Renal diseases are common in dogs and cats. Renal biopsy may be required during the evaluation of the patient to establish a definitive diagnosis, determine the severity of the lesion and formulate an optimal treatment plan. Renal biopsy specimens can be collected via several methods. Percutaneous techniques are performed with ultrasound guidance in both dogs and cats or blindly in cats. If ultrasound guidance is not available, the keyhole technique can be used in dogs. Biopsy can also be performed using laparoscopy or surgery. While complications can arise with any of these techniques, complications are less frequent when an experienced operator uses proper technique. Renal biopsy specimens must be processed and evaluated appropriately if consistent and accurate diagnoses are to be rendered. The article summarizes patient selection and evaluation, renal biopsy techniques, expected complications of renal biopsy, and appropriate processing and evaluation of the renal biopsy specimen.

Animals↗

PubMed2004

Renal biopsy: methods and interpretation.

Renal biopsy most often is indicated in the management of dogs and cats with glomerular disease or acute renal failure. Renal biopsy can readily be performed in dogs and cats via either percutaneous or surgical methods. Care should be taken to ensure that proper technique is used. When proper technique is employed and patient factors are properly addressed, renal biopsy is a relatively safe procedure that minimally affects renal function. Patients should be monitored during the post biopsy period for severe hemorrhage, the most common complication. Accurate diagnosis of glomerular disease, and therefore, accurate treatment planning,requires that the biopsy specimens not only be evaluated by light microscopy using special stains but by electron and immunofluorescent microscopy.

Animals↗

PubMed2004

Effects of urinary tract inflammation and sample blood contamination on urine albumin and total protein concentrations in canine urine samples.

BACKGROUND: Urinary tract inflammation and hemorrhage are believed to be common causes of proteinuria in dogs based on results of studies that measured total urine protein concentration. A method to quantify urine albumin (UAlb) concentration in dogs recently has become available; however, the effect of inflammation on albuminuria is unknown. OBJECTIVES: The goals of this study were to determine the effects of urinary tract inflammation, as indicated by pyuria and sample blood contamination, on UAlb concentration and on urine protein:creatinine (UPC) ratio in dogs. METHODS: Urine samples were obtained from dogs with pyuria that were presented to a veterinary teaching hospital or were part of a laboratory colony. To mimic the effects of hematuria, canine whole blood was added to a microscopically normal canine urine sample that had baseline albumin and total protein concentrations below the limits of detection. UAlb concentration was measured using a canine albumin-specific competitive ELISA. UPC ratio was determined using routine methods. RESULTS: Of 70 samples with pyuria, 67% had negligible UAlb concentrations and 81% had normal UPC ratios. UAlb concentration but not UPC ratio was significantly higher (P < 0.05) in samples with concurrent hematuria or bacteriuria. When whole blood was added to normal urine, UAlb concentration did not exceed 1 mg/dL until the sample became visibly pink; the UPC did not exceed 0.4 at any dilution. CONCLUSIONS: Many dogs with pyuria do not have albuminuria or proteinuria; however, albuminuria may be more likely in dogs with pyuria and concurrent hematuria or bacteriuria. Hematuria may not cause an increase in UAlb concentration until it becomes macroscopic and even then may not increase the UPC ratio.

Albuminuria↗

PubMed2004

The Clinician Investigator program in companion animal internal medicine at north Carolina State University.

A retrospective study was conducted to describe the development and evolution of the combined internal medicine/PhD program, the Clinician Investigator (CI) Program, at North Carolina State University. Separate survey instruments were developed for individuals who had committed to completing both the residency and PhD components and for graduate advisors of individuals who were granted the PhD degree. Results are summarized here. Most CIs reported believing that each component of the program (clinical training and research training) provided mutual benefits and that their teaching skills were enhanced, particularly as a result of instructing students in the Veterinary Teaching Hospital. Opinions among both the CIs and the graduate advisors were divided about the benefits of a combined program compared with a sequential program; however, all but one of 11 CIs who completed the survey would enroll in the combined program again. The graduate advisors were overwhelming positive about the CIs they had advised and indicated that they would welcome a CI as a PhD student in their laboratory again. Suggested areas for improvement included guaranteed salary/stipend support for the average time to completion (six years) instead of for five years, as well as more emphasis on and guidance in identifying a graduate advisor earlier in the CI program so as to smooth the transition between the clinical and research training components of the program. It is hoped that other training programs will benefit from the summary of our experience with this program.

Animals↗

PubMed2002

Detection of canine microalbuminuria using semiquantitative test strips designed for use with human urine.

BACKGROUND: Commercial testing for microalbuminuria in human urine is often performed with point-of-care semiquantitative test strips followed by quantitative testing when indicated. An ELISA that quantifies canine urine albumin concentration has been developed, but semiquantitative test strips for use in the dog are not available. OBJECTIVE: The purpose of this study was to prospectively determine the concordance of canine urine albumin concentrations measured by a commercial human test strip and by ELISA. METHODS: Urine samples were obtained from 67 dogs evaluated for a variety of clinical conditions. Dipstick urinalyses were performed on all samples; clinician discretion determined method of urine collection and performance of urine sediment examination and/or urine culture. Urine albumin concentration was determined using test strips (Clinitek Microalbumin, Bayer Corporation, Elkhart, Ind, USA), and results were compared with those obtained by ELISA. RESULTS: The Clinitek strips correctly determined albumin concentration in 42 of 67 (63%) urine samples tested. Concordance was lowest (48%) for dogs with microalbuminuria (10-300 microg/mL by ELISA). Clinitek strip sensitivity and specificity for correct identification of microalbuminuria were 48% and 75%, respectively. Concordance was lower in dogs with urinary tract infection or hematuria and in samples collected by catheterization. Sensitivity and specificity for correct identification of microalbuminuria after exclusion of dogs with urinary tract infection or hematuria were 59% and 83%, respectively. CONCLUSIONS: These results suggest that the Clinitek strips lack sufficient concordance with results obtained by ELISA to be a reliable screening for test microalbuminuria in the dog. A reliable semiquantitative point-of-care test for canine urine albumin concentrations below those detected by standard urine dipsticks is still needed.

Albuminuria↗

PubMedDate not supplied

In vitro prediction of canine urolith mineral composition using computed tomographic mean beam attenuation measurements.

Determination of urolith mineral composition is critical for management of urolithiasis in dogs and cats. Using computed tomography, urolith physical density, and hence chemical composition, can be quantified using mean beam attenuation measurements (Hounsfield units; HU). This study was designed to establish in vitro reference ranges for three types of compositionally pure uroliths retrieved from dogs. Sixty-six canine uroliths (22 uric acid, 21 calcium oxalate, 14 struvite, nine mixed or compound) were placed in a phantom array. Uroliths were scanned at 120 kVp, 200 mA, and 80 kVp, 200 mA. The region of interest (ROI) for mean HU calculation was determined using two techniques, and reference ranges were calculated for each kVp using either ROI technique. HU for urolith types of pure composition were statistically different (Wilcoxon's two-sample test, P < 0.0083 [Bonferonni correction with six comparisons for total P < 0.05]) using both ROI techniques at either kVp. Struvite uroliths were not statistically different from mixed or compound uroliths. The accuracy for determination of composition of pure uroliths ranged from 86% to 93%; the prediction accuracy for each urolith mineral type and for all uroliths in general was highest when the ROI was hand-drawn just within the visible urolith border at 80 kVp. Technique of ROI determination and kVp that yielded the highest sensitivity, specificity, and positive and negative predictive values varied for each urolith type. Therefore, in this study, HU could be used to differentiate three types of uroliths of pure mineral composition in vitro. Further studies are needed to determine the predictive value of HU in vivo.

Animals↗

PubMedDate not supplied

Persistent urinary tract infections and reinfections in 100 dogs (1989-1999).

A retrospective study was performed of 100 dogs with persistent urinary tract infections (UTIs) or reinfections presenting to the North Carolina State University (Raleigh, NC) Veterinary Teaching Hospital between 1989 and 1999. Criteria for selection included > or = 2 positive urine cultures within a 6-month period. Signalment, presence of predisposing disorders, urinalysis and urine culture results, and treatment strategies were extracted from the medical records. Dogs were a median age of 7 years when the UTI was 1st diagnosed. Dogs younger than 3 and older than 10 years were at increased and decreased risks, respectively, for reinfections or persistent UTIs. Spayed females were more common in the UTI population. More than half of the dogs were asymptomatic for a UTI at 1st presentation. Urine sediment examinations identified hematuria, pyuria, and bacteriuria in 47, 72, and 85% of the samples, respectively. The most commonly isolated organisms were Escherichia coli and Streptococcus/Enterococcus spp.; multiple isolates also were common. Of the isolates, 29.5% were resistant to achievable serum concentrations of all antibiotics commonly prescribed for PO administration. Dogs with abnormal micturition were more likely to have infections by organisms resistant to commonly prescribed antibiotics. Potentially predisposing disorders were identified in 71 dogs. A correction of these disorders was accomplished in 35% of these 71 dogs. Dogs given standard antibiotic therapy without addressing predisposing disorders experienced poor control of their UTIs; 74.5% of these dogs had an apparent disease-free interval (ADFI) of < 8 weeks. By comparison, dogs in which predisposing disorders were corrected or those that were treated with low-dose, long-term antibiotic regimens subjectively had better control.

Animals↗

PubMedDate not supplied

Fecal polymerase chain reaction with 16S ribosomal RNA primers can detect the presence of gastrointestinal Helicobacter in dogs.

Questions about pathogenesis and therapy for Helicobacter infections in dogs could be answered with a simple, noninvasive, sensitive, and specific diagnostic test. We hypothesized that a fecal polymerase chain reaction (PCR) assay would detect Helicobacter and could be useful for assessing therapeutic responses. Paired gastric biopsies and fecal samples were obtained from 39 random source dogs (group 1). Gastric biopsies from each of these dogs had histologic evidence of gastric spiral bacteria, and paired gastric tissue and fecal samples produced a 375-base pair (bp) product when amplified by PCR with Helicobacter-specific primers. Specificity of the PCR product was confirmed by detection of expected 60-, 119-, and 196-bp products following Hinfl digestion. Direct sequencing of amplicons from paired PCR products from gastric biopsy and fecal samples from 8 group I dogs showed that gastric products had the highest homologies with known gastric Helicobacter species, whereas fecal products had the highest homologies with intestinal species. Healthy mixed-breed dogs (group II; n = 8) with histologically confirmed spiral bacteria infection were treated with a 21-day course of metronidazole, amoxicillin, and famotidine. Fecal samples were collected from group II dogs twice before and within 3 days of completion of treatment. The PCR results correctly identified 15/16 pretreatment samples as positive: 1 pretreatment sample was negative. PCR results identified 8/8 posttreatment samples as Helicobacter negative. Fecal PCR is a useful test for detecting Helicobacter infection in dogs. This assay may be useful as a screening test for infection and could be used to address questions relevant to pathogenesis and therapy.

Animals↗

PubMedDate not supplied

Urinary tract manifestations of protothecosis in dogs.

Records of 13 dogs with systemic infection with Prototheca sp. from 3 veterinary teaching hospitals were reviewed. Acute renal failure secondary to disseminated infection with Prototheca zopfii was diagnosed in 2 dogs. In 1 dog, acute renal failure developed during administration of immunosuppressive drugs for treatment of anterior uveitis. During diagnostic evaluation of this dog, Prototheca sp. organisms were noted in urine sediment and renal biopsy specimens. In the 2nd dog, acute renal failure was diagnosed after treatment for bacterial cystitis. After diagnosis of protothecosis, organisms were successfully isolated by aerobic urine culture. Both dogs with acute renal failure did not respond to conventional medical therapy. In total, Prototheca sp. was noted in urine sediment in 4 of 8 dogs and successfully cultured from urine in 5 of 7 dogs. Four of 5 dogs had organisms noted in the kidneys on histopathologic examination. In all dogs, the species identified was P zopfii. Sensitivity testing of 3 isolates revealed wide differences in in vitro drug resistance. Examination and culture of urine is recommended as a practical method for diagnosis of systemic infection with Prototheca sp.

Acute Kidney Injury↗

PubMedDate not supplied

Assessment and management of proteinuria in dogs and cats: 2004 ACVIM Forum Consensus Statement (small animal).

Emerging data indicate that more attention should be given to the detection, evaluation, monitoring, and treatment of dogs and cats with proteinuria. The purposes of this consensus statement are to describe an appropriate approach for accomplishing these tasks and to provide specific recommendations for assessing and managing dogs and cats with proteinuria based on data that are currently available. Because proteinuria and albuminuria have numerous possible causes, they must be assessed appropriately to determine their implications for the patient. This assessment involves localization of the origin of the proteinuria as well as determination of its persistence and magnitude. Because persistent renal proteinuria usually indicates presence of chronic kidney disease, which sometimes is a progressive disorder, its detection identifies dogs and cats that have increased risk for adverse health outcomes. Thus, urine testing that will detect proteinuria should be a component of the clinical evaluations of dogs and cats under all circumstances that prompt their veterinarians to also perform comprehensive hematologic and serum biochemical evaluations. At a minimum, this testing should consist of a complete urinalysis that includes a satisfactorily accurate semiquantitative test for protein, and positive reactions should be properly followed with further testing. The appropriate response to persistent renal proteinuria depends on the magnitude of proteinuria and the status of the patient. The recommended response generally involves continued monitoring, further investigation, and therapeutic intervention, which should be implemented as an escalating series of inclusive, stepwise responses.

Animals↗

PubMedDate not supplied

Renal biopsy: a retrospective study of methods and complications in 283 dogs and 65 cats.

Renal biopsy often is required to establish a definitive diagnosis in dogs and cats with renal disease. In this retrospective study, we determined the complications of renal biopsy as well as factors that may be associated with development of complications and procurement of adequate renal biopsy specimens in 283 dogs and 65 cats. Data extracted from medical records at 4 institutions were evaluated using logistic regression. Proteinuria was the most common indication for renal biopsy in dogs. Complications were reported in 13.4 and 18.5% of dogs and cats, respectively. The most common complication was severe hemorrhage; hydronephrosis and death were uncommon. Dogs that developed complications after renal biopsy were more likely to have been 4 to < 7 years of age and > 9 years, to weigh < or = 5 kg, and to have serum creatinine concentrations > 5 mg/dL. The majority of biopsies from both dogs (87.6%) and cats (86.2%) were considered to be of satisfactory quality. Biopsies from dogs were more likely to be of high quality if they were obtained when the patient was under general anesthesia and more likely to contain only renal cortex if they were obtained by surgery. We concluded that renal biopsy is a relatively safe procedure, with a low frequency of severe complications. Hospital practices and patient variables have the potential to impact both the quality of the specimen obtained and the rate of complications.

Animals↗

PubMedDate not supplied

Candida spp. urinary tract infections in 13 dogs and seven cats: predisposing factors, treatment, and outcome.

Records from 20 animals (13 dogs, seven cats) with Candida spp. urinary tract infections were reviewed. Six Candida spp. were isolated; Candida albicans was the most common isolate. Concurrent diseases or nonantifungal drugs administered within 1 month of isolation included antibiotics (n=16), corticosteroids (n=6), diabetes mellitus (n=4), nonurogenital neoplasia (n=3), and noncandidal urogenital disease (n=14). All animals had sources of local or systemic immune compromise that likely predisposed to infection. Of five animals with resolution of infection, three did not receive specific antifungal treatment. The authors conclude that correction of predisposing conditions is likely critical for management of Candida spp. urinary tract infection.

Animals↗