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Biomedical subjects

Mary M Christopher

Publications and source records attributed to Mary M Christopher.

At least 19 recordsLinked to original sources
PubMed2007

Effect of intrathecal amikacin administration and repeated centesis on digital flexor tendon sheath synovial fluid in horses.

OBJECTIVE: To determine the effect of intrathecal amikacin administration and repeated tenovaginocentesis on the total nucleated cell count (TNCC), total protein (TP) concentration and cytologic characteristics of synovial fluid of the equine digital flexor tendon sheath (DFTS). STUDY DESIGN: Randomized, cross-over experimental design. ANIMALS: Adult horses (n=8). METHODS: Synovial fluid was aseptically collected from the DFTS and either 1 mL amikacin sulfate (250 mg/mL) or lactated Ringer's solution (LRS) was injected into the DFTS. Serial synovial fluid samples were obtained at 0, 12, 24, 48, and 72 hours. The opposite treatment was administered to the contralateral DFTS after a washout period of 2 weeks. RESULTS: Treatment increased TP concentration, TNCC, percentage of neutrophils, and neutrophil counts from baseline levels. There was no difference between treatment of the DFTS with amikacin or LRS. Values peaked at 12-24 hours after the initial centesis and then declined toward baseline levels. CONCLUSIONS: Injection and repeat centesis of the normal DFTS with 250 mg amikacin or an equivalent volume of LRS resulted in mild increases in synovial fluid analytes from baseline. Synovial inflammation in this study was not accompanied by lameness at the walk and measured analytes returned toward baseline levels within 12-24 hours of first injection. CLINICAL RELEVANCE: The effect of tenovaginocentesis and intrathecal administration of amikacin or LRS on DFTS synovial fluid values are modest in most horses; however, some horses can develop marked increases in synovial fluid values that may be interpreted as sepsis.

Amikacin↗
PubMed2006

Lymph node aspirate from a California wine-country dog.

A 4-year-old, male Golden Retriever was presented to the Veterinary Medical Teaching Hospital at the University of California-Davis with a history of lethargy, inappetance, and vomiting. The patient had generalized lymphadenomegaly, marked thrombocytopenia, mild anemia, and moderate hypoalbuminemia. Moderate to marked histiocytic inflammation and lymphocytic-plasmacytic reactivity of the mesenteric, left popliteal, and right mandibular lymph nodes were diagnosed cytologically. Many macrophages contained granular to amorphous material of a uniform blue color, occasionally in morula formation, suggestive of rickettsial organisms. Exposure to raw trout was subsequently documented, leading to a presumptive diagnosis of salmon poisoning disease (SPD). The patient responded quickly to doxycycline therapy for the causative agent of SPD (Neorickettsia helminthoeca). SPD should be considered as a differential diagnosis for a canine patient with clinical signs of vomiting, diarrhea, lethargy, and lymphadenomegaly; laboratory findings of thrombocytopenia and hypoalbuminemia; and potential exposure to raw fish from an endemic area. The cytologic finding of rickettsial inclusions within lymph node macrophages is reportedly seen within a majority of SPD cases and can be valuable in supporting a clinical suspicion of SPD, as it was in this case.

Anaplasmataceae Infections↗
PubMed2006

Guidelines for resident training in veterinary clinical pathology. II. Hematology.

BACKGROUND: The Education Committee of the American Society for Veterinary Clinical Pathology (ASVCP) identified a need for improved structure and guidance in training residents in clinical pathology. To begin to meet this need, guidelines for training in clinical chemistry were published in 2003. OBJECTIVE: The goal of this report is to define learning objectives and competencies in hematology, including coagulation and immunohematology. METHODS: These guidelines were developed and written with the input of ASVCP Education Committee members and peer experts. RESULTS: The primary objectives of training in hematology are: 1) to accrue a thorough, extensive, and relevant knowledge base of the types, principles, and properties of hematology tests and concepts of pathophysiology in animals; 2) to develop abilities to reason, think critically, communicate effectively, and exercise judgment in hematologic data interpretation and investigative problem-solving; and 3) to acquire technical and statistical skills important in hematology and laboratory operations. We also provide options and ideas for training activities and identify hematology resources useful for clinical pathology faculty and staff, training program coordinators, and residents. CONCLUSIONS: The guidelines define expected competencies that will help ensure proficiency, leadership, and the advancement of knowledge in veterinary hematology and provide a useful framework for didactic and clinical activities in resident-training programs. The learning objectives can readily be adapted to institutional and individual needs, interests, goals, and resources.

Animals↗
PubMed2006

Evaluation of the sensitivity and specificity of four laboratory tests for detection of occult blood in cockatiel (Nymphicus hollandicus) excrement.

OBJECTIVE: To compare sensitivity and specificity of cytologic examination and 3 chromogen tests for detection of occult blood in cockatiel (Nymphicus hollandicus) excrement. ANIMALS: 20 adult cockatiels. PROCEDURES: Pooled blood from birds was divided into whole blood and lysate aliquots. Excrement was mixed with each aliquot in vitro to yield 6 hemoglobin (Hb) concentrations (range, 0.375 to 12.0 mg of Hb/g of excrement). For the in vivo portion of the study, birds were serially gavaged with each aliquot separately at 5 doses of Hb (range, 2.5 to 40 mg/kg). Three chromogen tests and cytologic examination were used to test excrement samples for occult blood. Sensitivity, specificity, and observer agreement were calculated. RESULTS: In vitro specificity ranged from 85%to 100% for the 3 chromogen tests and was 100% for cytologic examination. Sensitivity was 0% to 35% for cytologic examination and 100% for the 3 chromogen tests on samples containing >or= 1.5 mg of Hb/g of excrement. In vivo specificity was 100%, 90%, 65%, and 45% for cytologic examination and the 3 chromogen tests, respectively. Sensitivity was 0% to 5% for cytologic examination and >or= 75% for all 3 chromogen tests after birds received doses of Hb >or= 20 mg/kg. Observer agreement was lowest for cytologic examination. CONCLUSIONS AND CLINICAL RELEVANCE: Chromogen tests were more useful than cytologic examination for detection of occult blood in cockatiel excrement. The best combination of sensitivity, specificity, and observer agreement was obtained by use of a chromogen test.

Animals↗
PubMed2005

Comparative analysis of expert and machine-learning methods for classification of body cavity effusions in companion animals.

A rule-based expert system using CLIPS programming language was created to classify body cavity effusions as transudates, modified transudates, exudates, chylous, and hemorrhagic effusions. The diagnostic accuracy of the rule-based system was compared with that produced by 2 machine-learning methods: Rosetta, a rough sets algorithm and RIPPER, a rule-induction method. Results of 508 body cavity fluid analyses (canine, feline, equine) obtained from the University of California-Davis Veterinary Medical Teaching Hospital computerized patient database were used to test CLIPS and to test and train RIPPER and Rosetta. The CLIPS system, using 17 rules, achieved an accuracy of 93.5% compared with pathologist consensus diagnoses. Rosetta accurately classified 91% of effusions by using 5,479 rules. RIPPER achieved the greatest accuracy (95.5%) using only 10 rules. When the original rules of the CLIPS application were replaced with those of RIPPER, the accuracy rates were identical. These results suggest that both rule-based expert systems and machine-learning methods hold promise for the preliminary classification of body fluids in the clinical laboratory.

Algorithms↗
PubMed2005

Effects of dietary antioxidant supplementation before and after oral acetaminophen challenge in cats.

OBJECTIVE: To determine effects of lipoic acid, vitamin E, and cysteine before and after oxidant challenge in cats. ANIMALS: 24 sexually intact adult cats. PROCEDURE: Cats were allocated into 4 equal groups. For 25 weeks, group A was fed a control dry diet and groups B, C, and D received this diet supplemented with vitamin E (2200 U/kg [dry matter basis {DMB}]) plus cysteine (9.5 g/kg [DMB]), lipoate (150 mg/kg [DMB]), or all 3 antioxidants together, respectively. Weights were measured every 3 days and venous blood obtained every 5 weeks for CBC; serum biochemical analyses; lymphocyte blastogenesis; thiobarbituric acid reactive substances concentration; and concentrations of plasma protein carbonyl, 8-OH d-guanosine, blood glutathione, plasma amino acid, lipoate, and dihydrolipoate. At 15 weeks, all cats received acetaminophen (9 mg/kg, PO, once), clinical effects were observed, and methemoglobin concentrations were measured. RESULTS: Lymphocyte blastogenesis increased transiently in group C and D cats. After acetaminophen administration, all groups had transient increases in methemoglobin within 4 hours and mild, brief facial edema; group C had decreased glutathione concentration and increased 8-OH d-guanosine concentration versus controls; and protein carbonyl concentration increased least for group B. Plasma lipoate and dihydrolipoate concentrations peaked by week 10 for groups C and D. Conclusions and Clinical Relevance-Lipoate, vitamin E, and cysteine did not have synergistic effects. Lipoate supplementation (150 mg/kg [DMB]) did not act as an antioxidant but appeared to enhance oxidant effects of acetaminophen. Vitamin E plus cysteine had protective effects.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2004

Cytologic diagnosis: expression of probability by clinical pathologists.

BACKGROUND: Clinical pathologists use descriptive terms or modifiers to express the probability or likelihood of a cytologic diagnosis. Words are imprecise in meaning, however, and may be used and interpreted differently by pathologists and clinicians. OBJECTIVES: The goals of this study were to 1) assess the frequency of use of 18 modifiers, 2) determine the probability of a positive diagnosis implied by the modifiers, 3) identify preferred modifiers for different levels of probability, 4) ascertain the importance of factors that affect expression of diagnostic certainty, and 5) evaluate differences based on gender, employment, and experience. METHODS: We surveyed 202 clinical pathologists who were board-certified by the American College of Veterinary Pathologists (Clinical Pathology). Surveys were distributed in October 2001 and returned by e-mail, fax, or surface mail over a 2-month period. Results were analyzed by parametric and nonparametric tests. RESULTS: Survey response rate was 47.5% (n = 96) and primarily included clinical pathologists at veterinary schools (n = 58) and diagnostic laboratories (n = 31). Eleven of 18 terms were used "often" or "sometimes" by >/= 50% of respondents. Broad variability was found in the probability assigned to each term, especially those with median values of 75 to 90%. Preferred modifiers for 7 numerical probabilities ranging from 0 to 100% included 68 unique terms; however, a set of 10 terms was used by >/= 50% of respondents. Cellularity and quality of the sample, experience of the pathologist, and implications of the diagnosis were the most important factors affecting the expression of probability. CONCLUSION: Because of wide discrepancy in the implied likelihood of a diagnosis using words, defined terminology and controlled vocabulary may be useful in improving communication and the quality of data in cytology reporting.

Adult↗
PubMed2004

Assessment of erythrocyte morphologic abnormalities in mallards with experimentally induced zinc toxicosis.

OBJECTIVE: To describe and quantify morphologic abnormalities in RBCs of mallards (Anas platyrhynchos) with experimentally induced zinc toxicosis. ANIMALS: 120 female mallards. PROCEDURE: Farm-raised mallards (6 to 8 months old) were used in the study. On day 0, 60 ducks received shot pellets orally by gavage (mean dose of zinc, 0.97 g); another 60 ducks underwent the same procedure without administration of pellets. On day 15, Romanowsky-stained blood smears were prepared from 53 control and 45 zinc-treated ducks (smears were examined retrospectively). In each smear, 200 RBCs were examined and numbers of erythrocytes with abnormal size, shape, or color were expressed as a percentage. Results were compared with PCV values and zinc dose. RESULTS: Mean PCV value was lower in all zinc-treated ducks, compared with control ducks, and was lower in zinc-treated ducks that died or were euthanatized before day 30 because of severe clinical disease, compared with those that survived. Zinc-treated ducks that survived had a high percentage of polychromatophilic RBCs, and those that that died before day 30 had high percentages of hypochromic RBCs, fusiform RBCs, and RBC nuclear abnormalities. There was no correlation between PCV value or RBC morphologic abnormalities and dose of zinc. CONCLUSIONS AND CLINICAL RELEVANCE: In ducks with severe zinc-induced hemolysis, findings indicated that functional iron deficiency may impair the effectiveness of the erythroid regenerative response and contribute to death. Erythrocyte nuclear abnormalities were consistent with mild dyserythropoiesis. These findings may be applicable to effects of other metal toxicoses and regenerative anemias in birds.

Analysis of Variance↗
PubMed2003

Cytology of the spleen.

Fine-needle aspiration of the spleen is a useful method for evaluation of reactive, inflammatory, and neoplastic disorders, particularly those that involve the hematopoietic system. Interpretation of splenic aspirates is enhanced by concurrent evaluation of blood and other hemic tissues.

Animals↗
PubMed2003

Cytologic diagnosis of peritoneal cestodiasis in dogs caused by Mesocestoides sp.

BACKGROUND: Canine peritoneal larval cestodiasis caused by tapeworm larvae of the genus Mesocestoides is an uncommon and possibly fatal disease that can result in ascites and peritonitis. Although abdominal fluid analysis is recommended for dogs with ascites, the cytologic features of Mesocestoides infection have not been described fully. OBJECTIVE: Our goal was to describe the cytologic features of Mesocestoides larvae and of associated ascitic fluid that was collected from the peritoneal cavity of 4 infected dogs. METHODS: Abdominal fluid was obtained from 4 dogs with Mesocestoides sp infection. Gross, chemical, and microscopic evaluations of the fluid were performed using standard techniques. RESULTS: Cytologic findings in 1 dog included intact acephalic metacestodes (larvae without 4 suckers, not tetrathyridia) in various stages of asexual development, whereas fluid from the other 3 dogs contained primarily calcareous corpuscles, remnant tissue specific to cestodes. Abdominal fluid typically was an exudate, with suppuration, hemorrhage, and evidence of necrosis. Total protein concentrations ranged from 2.4 to 5.3 g/dL. CONCLUSIONS: Abdominal fluid cytology was useful in the diagnosis of Mesocestoides larval infections in the peritoneal cavity of dogs with ascites. Observation of characteristic calcareous corpuscles or intact metacestodes can provide a definitive diagnosis of canine peritoneal larval cestodiasis in dogs.

Animals↗
PubMed2003

Three cases of canine bile peritonitis with mucinous material in abdominal fluid as the prominent cytologic finding.

BACKGROUND: Bile peritonitis is a severe, nonseptic inflammatory response to bile in the peritoneal cavity. It may result from generalized or localized leakage of bile due to spontaneous rupture of the biliary system or as a complication of biliary tract inflammation, obstruction, manipulation, or trauma. Cytologically, bile in abdominal fluid appears as golden-green granular pigment. OBJECTIVE: The purpose of this report is to describe the atypical cytologic features of abdominal fluid in 3 dogs with bile peritonitis. METHODS: As part of a diagnostic workup, abdominal fluid was obtained from 3 dogs with bile peritonitis and analyzed. In 2 dogs, fluid bilirubin concentration was determined and Hall's bile stain, Alcian blue-periodic acid-Schiff stain, and Mayer's mucicarmine stain were applied to direct smears of the fluid. RESULTS: Acellular mucinous fibrillar material in clumps and lakes was the prominent cytologic finding in the abdominal fluid from all 3 dogs. Bile pigment was not observed. Fluid from the 3 dogs contained increased numbers of inflammatory cells, predominantly neutrophils. Total protein concentration ranged from 2.9 to 5.6 g/dL. Fluid total bilirubin concentration was greater than twice that of the concurrent serum bilirubin concentration. Based on results of the special stains, the amorphous material was positive for mucosubstances, but was negative for bilirubin. In all dogs, bile peritonitis originated from a rent in the common bile duct. CONCLUSIONS: Bile peritonitis with fibrillar mucinous material in abdominal fluid has not been described previously in dogs. The material was similar to "white bile" observed in humans and experimentally in dogs as a sequela to extrahepatic biliary tract obstruction. When mucinous material is observed in abdominal fluid from dogs and the fluid bilirubin concentration is greater than twice the serum bilirubin concentration, rupture of the extrahepatic biliary tract should be suspected.

Animals↗
PubMed2003

Postgraduate training programs in veterinary clinical pathology in the United States and Canada (1998 to 2002).

BACKGROUND: Residency and graduate programs in veterinary clinical pathology provide specialized training for board certification and are important pathways to careers in clinical pathology diagnostics, teaching, and research. Information about training opportunities is useful for assessing disciplinary needs, outcomes, and changes, garnering program support, and providing objective data for program evaluation by faculty, trainees, and prospective applicants. OBJECTIVES: The goals of this study were to 1) compile detailed information on the number and types of postgraduate training programs in veterinary clinical pathology in the United States and Canada, 2) describe the goals, activities, strengths, and weaknesses of the programs, 3) assess the desirability of program accreditation and program standards, 4) identify supplemental training opportunities, and 5) evaluate changes in programs, trainees, and faculty 4 years later. METHODS: In July 1998, the American Society for Veterinary Clinical Pathology Education Committee sent a survey to representatives at the 31 schools and colleges of veterinary medicine in the United States and Canada and 31 diagnostic laboratories, private hospitals, and pharmaceutical companies. Survey data were compared with updated information obtained from training program coordinators in November 2002. RESULTS: Survey response rate was 94% for universities, 39% for nonuniversity institutions, and 66% overall. In 1998, there were 20 clinical pathology training programs, including residencies (n=10) and graduate programs combined with residency training (n=10), with 36 total training positions. In 2002, there were 25 training programs (14 residencies, 11 combined), with 52 total positions. The median faculty:trainee ratio was 2.0 in both years. Of 67 faculty members involved in training in 1998, 57 (85.1%) were board-certified in clinical pathology and 53 (79.1%) had DVM/PhD degrees. Net faculty numbers increased by 17 (25.4%) but the median per institution remained at 3.0. Primary program goals were 1) eligibility for and successful achievement of board certification in clinical pathology by the American College of Veterinary Pathologists, 2) proficiency in laboratory diagnostics, and 3) contemporary basic or applied research training. Many programs cited research opportunities, caseloads, and training in hematology and cytology as strengths. Program weaknesses included insufficient funding, too few faculty, and limited training in clinical chemistry and laboratory operations/quality assurance. Trainees completing programs within the past 5 years (n=70) were employed in academia (28.6%), diagnostic laboratories (32.9%), and industry (18.6%). For trainees completing programs between 1999 and 2002 (n=38), these percentages were 52.6%, 21.1%, and 7.9%, respectively. Most (62.5%) respondents supported program standards and accreditation, and 76% supported board review sessions for trainees. CONCLUSIONS: Opportunities for postgraduate training in veterinary clinical pathology increased between 1998 and 2002, with 5 new programs and 16 new training positions. These additions and the increased emphasis on diagnostic proficiency, efforts to strengthen training in clinical chemistry and quality assurance, and continuation of combined PhD-residency programs will help address the perceived need for increased numbers of qualified clinical pathologists in academia, diagnostic laboratories, and industry.

Accreditation↗
PubMed2003

Guidelines for resident training in veterinary clinical pathology. I. Clinical chemistry.

BACKGROUND: The Education Committee of the American Society for Veterinary Clinical Pathology identified a need for improved structure and guidance of clinical pathology resident training in clinical chemistry. OBJECTIVES: The committee's goal was to develop learning objectives and competencies in knowledge, abilities, and skills in clinical chemistry; provide options and ideas for training activities; and identify clinical chemistry resources useful for clinical pathology faculty, training program coordinators, and residents. METHODS: Guidelines were developed and written with the input of Education Committee members and peer experts. RESULTS: The primary objectives of clinical chemistry training are: 1) to accrue a thorough, extensive, and relevant knowledge base of the types, principles, and properties of clinical chemistry tests and concepts of pathophysiology in animals; 2) to develop abilities to reason, think critically, and exercise judgment in clinical chemistry data interpretation, investigative problem-solving, and hypothesis-driven research; and 3) to acquire technical and statistical skills important in clinical chemistry and laboratory operations. CONCLUSIONS: These guidelines define expected competencies that will help ensure proficiency, leadership, and the advancement of knowledge in veterinary clinical chemistry and provide a useful framework for didactic and clinical activities in resident training programs. The learning objectives can readily be adapted to institutional and individual needs, interests, goals, and resources.

Animals↗
PubMed2003

Clinical disease and laboratory abnormalities in free-ranging desert tortoises in California (1990-1995).

Desert tortoise (Gopherus agassizii) populations have experienced precipitous declines resulting from the cumulative impact of habitat loss and human and disease-related mortality. Diagnosis of disease in live, free-ranging tortoises is facilitated by evaluation of clinical signs and laboratory test results but may be complicated by seasonal and environmental effects. The goals of this study were: 1) to describe and monitor clinical and laboratory signs of disease in adult, free-ranging desert tortoises at three sites in the Mojave Desert of California (USA) between October 1990 and October 1995; 2) to evaluate associations between clinical signs and hematologic, biochemical, serologic, and microbiologic test results; 3) to characterize disease patterns by site, season, and sex; and 4) to assess the utility of diagnostic tests in predicting morbidity and mortality. Venous blood samples were obtained four times per year from tortoises of both sexes at the Desert Tortoise Research Natural Area (DTNA), Goffs/Fenner Valley, and Ivanpah Valley. Tortoises were given a physical examination, and clinical abnormalities were graded by type and severity. Of 108 tortoises, 68.5% had clinical signs of upper respiratory tract disease consistent with mycoplasmosis at least once during the study period. In addition, 48.1% developed moderate to severe shell lesions consistent with cutaneous dyskeratosis. Ulcerated or plaque-like oral lesions were noted on single occasions in 23% of tortoises at Goffs and 6% of tortoises at Ivanpah. Tortoises with oral lesions were significantly more likely than tortoises without lesions to have positive nasal cultures for Mycoplasma agassizii (P = 0.001) and to be dehydrated (P = 0.0007). Nine tortoises had marked azotemia (blood urea nitrogen [BUN] > 100 mg/dl) or persistent azotemia (BUN 63-76 mg/dl); four of these died, three of which had necropsy confirmation of urinary tract disease. Laboratory tests had low sensitivity but high specificity in assessing morbidity and mortality; there was marked discrepancy between serologic and culture results for M. agassizii. Compared with tortoises at other sites, tortoises at DTNA were more likely to be seropositive for M. agassizii. Tortoises at Goffs were significantly more likely to have moderate to severe shell disease, oral lesions, positive nasal cultures for M. agassizii, and increased plasma aspartate aminotransferase activity. The severe disease prevalence in Goffs tortoises likely contributed to the population decline that occurred during and subsequent to this study.

Animals↗