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Biomedical subjects

J W Tyler

Publications and source records attributed to J W Tyler.

141 records · Page 8Linked to original sources
PubMedDate not supplied

Evaluation of 3 assays for failure of passive transfer in calves.

This study examined the sensitivity, specificity, predictive values, and classification accuracy of 3 commonly used screening tests for failure of passive transfer: the sodium sulfite turbidity test, the zinc sulfate turbidity test, and refractometry relative to serum immunoglobulin G1 (IgG1) concentrations determined by radial immunodiffusion. Serum samples were obtained from 242 calves ranging from 1 to 8 days of age. Using a serum concentration of 1,000 mg/dL IgG1, to define adequate passive transfer, the zinc sulfate test had a sensitivity of 1.00 and a specificity of 0.52 in the detection of inadequate passive transfer. The endpoint of the test appeared to be higher than desired; calves testing negative had mean serum IgG1 concentration of 955 mg/dL and a large proportion of calves with adequate passive transfer were misclassified as positive for failure of passive transfer. Using the qualitative zinc sulfate test, the percentage of calves correctly classified with regard to passive transfer status was less than that observed with either the sodium sulfite test or refractometry. The sensitivity of the sodium sulfite assay was 0.85 at a 1+ endpoint and 1.00 at a 2 or 3+ endpoint. The specificity of the sodium sulfite assay varied from 0.87 at a 1+ endpoint and 0.56 at a 2+ endpoint. The sensitivity and specificity of refractometry varied from 0.01 to 1.00 depending on the choice of endpoint. Refractometry correctly classified the largest proportion of calves with regard to their passive transfer status at test endpoints of 5.0 and 5.5 g/dL, 83% and 82% respectively. The highest percentages of calves correctly classified occurred with the sodium sulfite test using a 1+ endpoint (86.30%) and refractometry using a 5.0 g/dL endpoint (83.00%). A regression equation was developed that permitted calculation of an optimal endpoint for refractometric determinations of total serum protein concentration. A serum protein concentration of 5.2 g/dL was equivalent to 1,000 mg/dL serum IgG1. Optimal selection of tests for passive transfer status in calves will be governed by the prevalence of failure of passive transfer, test performance, and the anticipated costs of classification errors.

Analysis of Variance↗
PubMedDate not supplied

Prediction of serum IgG1 concentration in Holstein calves using serum gamma glutamyltransferase activity.

We examined the relationship between serum gamma glutamyltransferase (GGT) activity and serum gamma immunoglobulin G (IgG1) concentration in Holstein calves. Blood samples were collected from calves aged 1 to 3 days. A follow-up sample was obtained from each calf 2, 7, or 15 days after the initial sampling. Serum GGT activity and IgG1 concentration were measured. Regression models were used to predict IgG1 concentration as a function of age and serum GGT activity measured 2, 7, or 15 days later. Serum GGT activity and calf age at the time of the second sample were directly related to serum IgG1 concentration in the initial sample in calves aged 3 to 17 days (r = .54) and in calves aged 3 to 10 days (r = .63). Models were used to estimate the serum GGT activity equivalent to a serum IgG1 concentration of 1,000 mg/dL. One-day-old calves should have serum GGT activities > 200 IU/L. Four-day-old calves should have serum GGT activities > 100 IU/L. One-week-old calves should have serum GGT activities > 75 IU/L. Calves with serum GGT activities < 50 IU/L should be classified as having failure of passive transfer.

Aging↗
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Hemolysis associated with water administration using a nipple bottle for human infants in juvenile pygmy goats.

A 4-month-old, 6.8-kg, castrated male pygmy goat was examined for recurrent episodic fever and red urine of 7 days' duration. A second, 3-month-old, 7-kg, intact female pygmy goat was presented for similar clinical signs. The red discoloration of the urine in each case was determined to be due to hemolysis with subsequent hemoglobinuria. In both cases, hemolysis and hemoglobinuria were closely associated with the goats consuming large volumes of water from a human infant's nipple bottle. A diagnosis of water intoxication-induced hemolysis and hemoglobinuria was made. Episodes of hemoglobinuria in the first case were consistently associated with dilute (specific gravity < 1.010) urine. Water intoxication has been associated with bottle-feeding in human infants and is also widely reported in human psychiatric patients. The small erythrocytes in goats appear to be the most sensitive of the domestic species to hypotonicity-induced hemolysis.

Animals↗
PubMedDate not supplied

Use of serum protein concentration to predict mortality in mixed-source dairy replacement heifers.

The relationship between serum protein concentration in the 1st week of life and survival to 16 weeks of age was examined in 3,479 Holstein replacement heifers over a period of 10 years on a farm with endemic salmonellosis. Thirty-four percent of calves studied had serum protein concentrations < 5.0 g/dL and 60.5% of calves had serum protein concentrations < 5.5 g/dL. Cumulative mortality was 7.9%, indicating that calves with marginal passive transfer status can be reared successfully under conditions of endemic salmonellosis. Optimal survival was observed in calves with serum protein concentrations > 5.5 g/dL. Calves with serum protein concentrations of 5.0-5.4 g/dL had only a slightly increased relative risk (RR) of mortality (RR = 1.3) compared to calves with serum protein concentrations > 5.5 g/dL. The highest RR was experienced by calves with serum protein concentrations < 4 g/dL (RR = 4.6) and 4.0-4.4 g/dL (RR = 3.1). Calves with inadequate passive transfer (serum protein concentration < 5.0 g/dL), experienced increased mortality until at least 10 weeks of age, indicating that failure of passive transfer has an effect on calf health that extends into the juvenile period. Models in which serum protein concentration was treated with as a continuous variable or as a categorical variable failed to demonstrate any significant interaction between baseline mortality and the RR of mortality. This finding suggests that the RR derived in the present study should be applicable to farms with dramatically different baseline mortality rates.

Aging↗
PubMedDate not supplied

Survival in dogs with nasal adenocarcinoma: 64 cases (1981-1995).

Case records of 64 dogs with nasal adenocarcinoma were reviewed. The effects of age, gender, tumor stage, presence of metastatic lesions, and treatment method on survival time were examined. Surgery groups included rhinotomy (n = 9), transnasal curettage (n = 29), and no surgery (n = 26). Chemotherapy groups included fluorouracil-cyclophosphamide combination therapy (n = 15), mitoxantrone (n = 7), and no chemotherapy (n = 42). Fifty-three dogs received fractionated cobalt 60 radiation therapy. Surgical procedure, chemotherapy group, and stage of primary tumor were not significantly associated with survival time (P > .05). Dogs that received radiation therapy had a significantly longer median survival time (424 days) than dogs that did not (126 days)(P = .0001). The presence of either regional lymph node or pulmonary metastasis was associated with significantly shorter median survival time (109 days) when compared to dogs without metastases (393 days)(P = .0125). When only dogs that had received radiation therapy were considered, neither surgical treatment nor chemotherapy group was associated with significant changes in median survival time. An alternate staging system emphasizing the presence or absence of metastases is proposed.

Adenocarcinoma↗
PubMedDate not supplied

Prediction of serum IgG1 concentration in beef calves based on age and serum gamma-glutamyl-transferase activity.

This study examined the relationship between serum gamma-glutamyl-transferase (GGT) activity and passive transfer status in beef calves less than 18 days of age. Immunoglobulin G1 (IgG1) concentrations were measured in 69 commercial beef calves between the ages of 24 and 72 hours. GGT activities were then measured in these same calves at various ages between 3 and 18 days of age. Models were developed predicting serum IgG1 concentration as a function of calf age and serum GGT activity. Minimal association was present between initial serum IgG1 concentration and serum GGT activity when all calves less than 18 days of age were considered (r2 = 0.065). When the study population was restricted to calves less than 8 days of age, the fit of the developed model was greatly improved (r2 = 0.438). Serum GGT activity has no apparent advantage relative to other assay procedures for predicting passive transfer status in beef calves. If serum GGT activity is to be used to assess passive transfer status in beef calves, application of this procedure should be restricted to calves less than 8 days of age.

Aging↗
PubMedDate not supplied

Naturally occurring scrapie in Southdown sheep.

The purpose of this study was to characterize naturally occurring scrapie in the Southdown breed of sheep. Experimental subjects included 4 Southdown ewes admitted to the University of Missouri, College of Veterinary Medicine Large Animal Clinic. All 4 sheep had signs compatible with clinical scrapie. Cerebrospinal fluid (CSF) cell counts ranged from a low of 1 nucleated cell/microL to high of 4 cells/microL with a median of 3 cells/microL. Cerebrospinal protein concentrations ranged from 26 to 78 mg/dL with a median of 53 mg/dL. Immunoassay of the CSF for the 14-3-3 protein yielded positive results in 3 of the 4 sheep. Sequencing of the prion protein (PrP) gene revealed that all 4 sheep were homozygous for glutamine at codon 171 and, hence, were of the QQ genotype. Histopathologic examination of brain stem tissue sections revealed intracytoplasmic neuronal vacuolation and mild spongiform changes in the gray matter neuropil in all 4 ewes. The diagnosis of scrapie was confirmed by immunohistochemical staining for the abnormal PrP Our results suggest that the genetics of scrapie susceptibility are probably similar in Suffolk and Southdown sheep. Positive immunoassay results for the 14-3-3 protein were observed in 3 of the 4 sheep.

14-3-3 Proteins↗
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Partitioning the mortality risk associated with inadequate passive transfer of colostral immunoglobulins in dairy calves.

This study developed a method to partition the risk of mortality in dairy calves in the 1st 16 weeks of life. Observed population mortality and the relative risk of mortality in each serum protein concentration stratum were used to determine the population baseline mortality rate and the mortality rate due to inadequate passive transfer of colostral immunoglobulin. A total of 3,479 calves were studied, 8.2% of which died before 16 weeks of age. The population baseline mortality rate was 5.0% and the mortality rate due to inadequate passive transfer was 3.2%. Thirty-nine percent of the observed mortality was attributed to inadequate passive transfer. This partitioning of risk between passive transfer-related and unrelated sources should prove useful in conducting investigations of calf mortality problems in dairy herds.

Animal Husbandry↗
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Passive transfer of colostral immunoglobulins in calves.

Passive transfer of colostral immunoglobulins has long been accepted as imperative to optimal calf health. Many factors, including timing of colostrum ingestion, the method and volume of colostrum administration, the immunoglobulin concentration of the colostrum ingested, and the age of the dam have been implicated in affecting the optimization of absorption. The practice of colostrum pooling, the breed and presence of the dam, and the presence of respiratory acidosis in the calf also may affect passive transfer. Various tests have been reported to accurately measure passive transfer status in neonatal calves. The radial immunodiffusion and the enzyme-linked immunosorbent assay (ELISA) are the only tests that directly measure serum IgG concentration. All other available tests including serum total solids by refractometry, sodium sulfite turbidity test, zinc sulfate turbidity test, serum gamma-glutamyl transferase activity, and whole blood glutaraldehyde gelation estimate serum IgG concentration based on concentration of total globulins or other proteins whose passive transfer is statistically associated with that of IgG. This paper presents a comprehensive review of the literature of passive transfer in calves including factors that affect passive transfer status, testing modalities, effects of failure of passive transfer on baseline mortality, consequences of failure of passive transfer, and some treatment options. Many previously accepted truisms regarding passive transfer in calves should be rejected based on the results of recent research.

Acidosis↗
PubMedDate not supplied

Endoscopic retrieval of a large, nasopharyngeal foreign body.

A 1.5-year-old golden retriever was presented for stertorous respiration, reverse sneezing, halitosis, and a bilateral mucopurulent nasal discharge. A bone-density, nasopharyngeal foreign body was visualized on lateral radiographs of the skull. The foreign body was removed using a videoendoscope and a basket retrieval forcep. The dog's clinical signs resolved following foreign body removal.

Animals↗
PubMedDate not supplied

Cutaneous mast cell tumors in cats: 32 cases (1991-1994).

Case records of 32 cats with cutaneous mast cell tumors (CMCTs) were reviewed. Using the Patnaik system for grading canine mast cell tumors, the relationships between histopathological grade and patient survival time and tumor recurrence were examined. Tumor histopathological grade had no prognostic significance. One-, two-, and three-year tumor recurrence rates following surgical excision were 16%, 19%, and 13%, respectively. Incomplete excision was not associated with a higher rate of tumor recurrence.

Animals↗
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Clinical assessment of a chemosensitivity assay as a treatment planning tool for dogs with cancer.

This study evaluated the clinical utility of a commercially available chemosensitivity assay. In the first part of the study, tumor tissues from dogs with various malignancies were tested, and the dogs were treated with a mitoxantrone/cyclophosphamide combination protocol. Tumor response was evaluated and compared to the predicted response. Assay results were not a significant predictor of clinical response to chemotherapy or of survival time. In the second part of the study, assay results were used to direct therapy in dogs with refractory lymphoma. There was no significant correlation (p equals 0.323) between predicted response and case outcome.

Animals↗
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Effect of passive transfer status and vaccination with Escherichia coli (J5) on mortality in comingled dairy calves.

The effect of vaccination with a commercially available R-mutant coliform mastitis vaccine on the survival of comingled dairy calves on a farm with endemic salmonellosis was examined. A total of 864 calves were randomly assigned to either vaccine (n = 435) or control (n = 429) groups. Passive transfer status of each calf was determined using refractometer determination of serum total protein concentration. Logistic models were developed to determine the effects of vaccine group and passive transfer status on calf survival to 100 days of age. In a model in which serum protein concentration was treated as a categorical variable, increasing serum total protein concentrations were associated with decreased mortality until these concentrations exceeded 6.0 g/dL. Calves with serum protein concentrations > 6.0 g/dL had increased risk for mortality compared with calves with serum protein concentrations > 5.5 g/dL but < or = 6.0 g/dL. This increased risk for mortality was supported by the results of a logistic model in which serum protein concentration was treated as a continuous variable. The increased risks associated with high serum protein concentration probably reflect the effect of dehydration in calves with occult disease. Neither model demonstrated any significant association between vaccination status and survival to 100 days of age. Based on these results, the routine immunization of calves cannot be recommended as a strategy to prevent mortality on farms with endemic salmonellosis.

Animal Husbandry↗
PubMedDate not supplied

Detection of low serum immunoglobulin concentrations in clinically ill calves.

The sensitivity, specificity, and accuracy of classification of 4 tests for failure of passive transfer (FPT) were examined in clinically ill neonatal calves. Comparisons were made with serum IgG1 concentrations determined by radial immunodiffusion. Serum samples were obtained from 27 clinically ill calves < or = 21 days of age. The results of 4 commonly used assays, the sodium sulfite turbidity test, the zinc sulfate turbidity test, refractometry, and the serum gamma-glutamyl transferase (GGT) activity test, were compared with radial immunodiffusion determinations of serum IgG1 concentration. Serum GGT activity using a 50 IU/L threshold resulted in correct classification of the highest percentage of calves (93%) with regard to their passive transfer status. The sodium sulfite test with a 1+ end point and refractometry using a 5.5 g/dL end point resulted in correct classification of 85% of the calves studied. When using the sodium sulfite test, the 2+ and 3+ test end points had lower specificity, 0.58 and 0.00, respectively, than the 1+ end point. This loss in specificity resulted in misclassification of calves with adequate serum immunoglobulin concentrations as having FPT. The zinc sulfate turbidity test was inadequately specific (0.33) and resulted in misclassification of 33% of calves.

Animals↗