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Biomedical subjects

J B Kaneene

Publications and source records attributed to J B Kaneene.

At least 91 records · Page 5Linked to original sources

The use of mammals as sentinels for human exposure to toxic contaminants in the environment.

The use of sentinel species shows the potential to bridge the gap between animal-based and human-based environmental health research. With regard to the assessment of environmental contamination, the use of the terms "indicator," "monitor," and "sentinel" has often been confusing and ambiguous. A set of definitions is proposed as a standard to rectify this situation. The advantages of the use of sentinel species are provided, as well as criteria for sentinel selection, based on species characteristics. The recent use of mammals as sentinels for human exposure to toxic environmental contaminants is reviewed. A tabulated review of mammals proposed as indicators or monitors is included, as these may act as a database for the selection of sentinel species for future research efforts. The complexity and subtlety of factors interacting between an organism and its environment make it imperative that one provide a focused definition of what one wants the sentinel to assess and for what particular aspect of human health. Some examples of how sentinels might be selected for particular research questions are provided. While the potential for sentinel use in the field of environmental health is enormous, future investigators need to choose sentinels carefully, based on well-defined research questions, and confine conclusions drawn to the particular problem the sentinel was chosen to assess.

Animals↗

Management risk factors associated with calf diarrhea in Michigan dairy herds.

A study was conducted to examine the relationships between various dairy herd management practices and the monthly incidence density of calf diarrhea. The data were collected during a recent 2-yr prospective cohort study by the Michigan National Animal Health Monitoring System. The data were statistically analyzed, and predictive models were developed. For herds with 10 to 49 adults cows, variables predicting an increase in the incidence of diarrhea in calves were number of young stock in the herd, incidence of respiratory disease in calves, and cumulative incidence of vaccinations for calves to prevent diarrheal disease. Increased numbers of routine veterinary visits to the farm were associated with decreased incidence of calf diarrhea. For herds with 50 to 99 adult cows, the positive predictor variable was incidence of respiratory disease in calves. Negative predictor variables were used of individual calving areas and removal of bedding between calvings. For herds with 100 to 199 adult cows, positive predictor variables were cumulative incidence of vaccinations for calves to prevent diarrheal disease and number of young stock in the herd. For herds with > 200 adult cows, positive predictor variables were use of individual calving areas, number of routine veterinary visits to the farm, and incidence of respiratory disease in calves. These variables accounted for 13.1, 17.7, 7.4, and 64.2% of the variability in the incidence of calf diarrhea in the respective herd size groups.

Animals↗

Anatomic features and radiographic observations of gastric emptying and small intestinal motility in the rat.

This study presents the first report of the identification of anatomic structures on survey radiographs of the abdomen of the rat, along with detailed barium contrast studies of the gastrointestinal tract in normal rats. The rats (49 to 112 days old) were chemically restrained with a combination of 0.71 mg ketamine hydrochloride/g of body weight and 0.5 mg of acetylpromazine maleate injected intramuscularly. Following sedation, a 36% (wt/vol) micropulverized barium sulfate suspension was administered via a stomach tube at a dose of 0.02 ml/g of body weight. The radiographic features of the gastrointestinal tract were enhanced after coating of the mucosal surfaces with the high-density barium suspension. Internal structures of the stomach and mucosal surfaces of the intestine were clearly identified. The barium contrast study was used to establish gastrointestinal transit times. The mean gastric emptying time was 11 +/- 4.27 (SEM) min and mean intestinal transit time was 5 +/- 0.75 (SEM) h. Image intensification fluoroscopy was used to observe patterns of small intestinal motility and to establish small intestinal contraction rates. Prominent cluster of circular contractions were primarily observed in the jejunum, and wave-type peristalsis was primarily observed in the duodenum. Isolated circular contractions and weak segmentation patterns were observed in the ileum. The mean contraction rate per minute was observed to be 14 +/- 2.12 (SEM) in the jejunum. We propose that under the conditions of the current study, radiographic investigation of gastrointestinal function in rats is a feasible and inexpensive procedure.

Animals↗

The effects of nitrate, nitrite and N-nitroso compounds on human health: a review.

The effects of nitrate, nitrite, and N-nitroso compounds on human health are reviewed. Special emphasis has been placed on the role of these compounds on infant methemoglobinemia and gastric cancer. The discussion on methemoglobinemia includes the source of nitrate or nitrite, diagnosis, treatment, prevention and the contributions of age, gastric pH, gastrointestinal illness, and ingestion of vitamin C to this illness. The maternal transfer of these compounds and the potential effect on fetal death and malformation are also described. The etiology and development of gastric cancer is reviewed as well as the roles of nitrate, nitrite, and N-nitroso compounds in this disease. Endogenous nitrosation and the experimental and epidemiologic evidence linking these compounds to gastric cancer is examined. Other sections include adult methemoglobinemia and acute toxicity, hypo- and hypertension, Balkan nephropathy, slowing of motor reflexes in children, nitrate esters dependence. Sources of nitrate, nitrite, and N-nitroso compounds are detailed. Future areas of research are given.

Adult↗

The effects of nitrate, nitrite, and N-nitroso compounds on animal health.

The clinical signs of acute nitrate toxicity vary according to species. In general, ruminant animals develop methemoglobinemia while monogastric animals exhibit severe gastritis. Nitrate ingestion has also been linked to impairment of thyroid function, decreased feed consumption, and interference with vitamin A and E metabolism. Hematologic changes seen with chronic high nitrate exposure include both compensatory increases in red blood cells and anemia, along with increased neutrophils and eosinophils. Unlike nitrate, nitrite is capable of inducing methemoglobinemia in a wide range of species, ie cattle, sheep, swine, dogs, guinea pigs, rats, chickens and turkeys. In rats, chronic nitrite exposure causes pathologic changes in a variety of tissues, alterations in motor activity and brain electrical activity, and alters gastric mucosal absorption. Nitrite affects the metabolism of sulfonamide drugs in animals such as the pig, guinea pig, and rat. The N-nitroso compound dimethylnitrosamine causes toxic hepatosis in cattle, sheep, mink, and fox. Nitrosamines have been reported in cows milk and been found to pass into the milk of goats under experimental conditions.

Abortion, Veterinary↗

Use of nonsteroidal anti-inflammatory drugs in food animal practice.

We attempted to determine the extent to which nonsteroidal anti-inflammatory drugs (NSAID) are used in the treatment of food animals, and whether withdrawal times for milk and slaughter are recommended to clients. A survey questionnaire was mailed to a stratified random sample of 2,000 veterinarians whose practices were at least half food animals. A cross-sectional study was used to examine the responses to determine whether differences existed on the basis of a respondent's geographic location, number of years since graduation from veterinary college, and percentage of practice devoted to beef and dairy cattle. The response rate was 71% (1,424/2,000). Of those practitioners responding, 93% (1,325/1,424) reported using NSAID, with approximately 57 (751/1,322), 24 (327/1,322), and 18% (244/1,322) of respondents reporting use more than once a week, once a week, and 1 to 2 times per month, respectively. Dairy practitioners reported more frequent use than did beef practitioners. Use of flunixin meglumine was reported more frequently than the use of aspirin, phenylbutazone, or dipyrone. Approximately 88% (1,146/1,306) of respondents that used NSAID did so in combination with antibiotics. Withdrawal times for milk and meat were made on the basis of guidelines for the antibiotic. When using NSAID alone, recommendations for withdrawal times for milk and meat varied extensively. Overall, practitioners indicated that NSAID were useful and necessary for the treatment of food-producing animals.

Animals↗

Description and evaluation of the influence of veterinary presence on the use of antibiotics and sulfonamides in dairy herds.

A longitudinal study was conducted over 2 years to identify types of antibiotics and sulfonamides used in Michigan dairy herds for disease prevention and treatment, to determine patterns of use of antibiotics and sulfonamides by herd size and animal age group, and to determine the influence of veterinary presence during diagnosis on the types of antimicrobials used for disease treatments. In order of frequency, the most commonly used preventive antibiotic and sulfonamides were penicillins, tetracyclines, aminoglycosides, and cephalosporins, making up over 86% of all antimicrobials used for disease prevention. The most commonly used therapeutic antibiotics and sulfonamides were penicillins, tetracyclines, aminoglycosides, and sulfonamides, making up over 81% of all antimicrobial drugs used for disease treatment. Cows received the greatest number of drugs, followed by calves (cattle from birth to weaning). Young stock (cattle from weaning to first calving) received the lowest number of drugs. All herds had similar patterns of drug use for the 3 age groups, regardless of herd size. With the exception of polymyxin and chloramphenicol, producers used antibiotics on their own more than with a veterinarian present or on the advice of a veterinarian. Overall, veterinary presence was significantly associated with increased use of tetracyclines, sulfonamides, and nitrofurans, and decreased use of penicillins and aminoglycosides. Implications for drug residue prevention strategies are discussed, with emphasis on the role of the practicing veterinarian.

Animals↗

Diagnostic techniques for transvaginal-transuterine aspiration of bovine fetal fluid during the early fetal period.

Studies were designed to evaluate 2 methods for transvaginal-transuterine collection of bovine fetal fluids. The first technique (direct) required simultaneous transrectal palpation and retraction of the gravid uterus and direct, intravaginal manipulation of a needle and vacuum tube assembly. The direct technique was only suitable for use in multiparous animals and was attempted when fetal age ranged from Day 55 to Day 75. The second technique (indirect) may be used in primiparous cows, because aspiration was accomplished through a plastic infusion pipet, altered by attachment of a needle to its tip. When this technique was used, fetal age ranged from Day 50 to Day 65. The direct technique provided more control over needle placement and resulted in a higher success rate for aspiration of fetal fluid following single needle penetration (77 versus 50%). Both techniques were associated with rates of abortion (3/13 for the direct and 4/10 for the indirect) that were judged to preclude prospective use in diagnostic strategies for first trimester fetal wastage. Within the controlled study, the diagnostic quality of the aspirate was determined. It was concluded that the altered pipet technique provided aspirates that were of diagnostic, noncontaminated quality. Field use of fetal fluid aspiration following discovery of nonviable pregnancies by B-mode ultrasonography is discussed.

Journal Article↗

Clinical evaluation of intertrochanteric osteotomy for treatment of dogs with early-stage hip dysplasia: 37 cases (1980-1987).

Between May 1980 and May 1987, intertrochanteric osteotomy was performed on 43 hips of 37 dogs (6 bilateral procedures) with early-stage hip dysplasia, with the objectives of improving hip biomechanics and reducing discomfort. Clinical evaluation consisted of: questionnaire, and/or orthopedic examination, and/or report from owner(s) via telephone. At least 1 form of evaluation was conducted for 42 of 43 hips (98%). On the basis of orthopedic examination findings, 27 of 33 hips (84%) were functionally good or normal at postoperative month 15 (on average). On the basis of owner report, 19 of 28 hips (68%) were functionally good or normal at postoperative month 11 (on average). On the basis of questionnaire data, 17 of 24 hips (70%) were functionally good or normal at postoperative year 1. Before surgery, only 11 of 37 hips (30%) had been evaluated as functionally good or normal. Of 36 owners, 33 (91.6%) reported that they would have the procedure performed again if the circumstances were the same. From the good to excellent clinical results, we concluded that intertrochanteric osteotomy is a beneficial treatment for dogs with early-stage hip dysplasia.

Animals↗

Cost of mastitis and its prevention in four dairy cattle herds on St Croix, US Virgin Islands.

Nonclinical mastitis in the dairy herds on St Croix, US Virgin Islands, represents a prevalent (97%) and severe problem (44% of quarters had California Mastitis Test results of 2 or 3). Streptococcus agalactiae (26%) and Staphylococcus aureus (22%) were the most prevalent pathogens. More than half (54%) of all organisms isolated and tested for resistance were resistant to ampicillin and benzyl penicillin; 29% were resistant to trimethoprim/sulfadiazine. Estimates of the loss of milk production suggested that there was a loss of 4.40 to 13.33 lb/cow/day. The yearly economic cost of prevention was estimated for each cow ($22.07); yearly income loss attributable to mastitis was estimated to be from $339 to $1,022/cow/yr. Suggestions for the prevention and control of mastitis are included.

Animals↗

Reproductive difficulties in cattle with antibody titers to Haemophilus somnus.

A herd of Holstein cows was examined because of suspected embryonic death. Four cows had embryonic loss, and 2 cows had aborted. Paired serum samples were tested for antibodies to infectious bovine rhinotracheitis virus, bovine viral diarrhea virus, and Haemophilus somnus. Of 16 cows, 8 had antibody titers to H somnus greater than 1:1,024, and 3 had greater than or equal to four-fold changes in antibody titers to H somnus. Haemophilus somnus infection was active in this herd and may have been responsible for the herd's reproductive problems.

Abortion, Veterinary↗

Intramuscular injection techniques and the development of clostridial myositis or cellulitis in horses.

A survey of 584 veterinarians in equine practice was performed to determine their intramuscular injection techniques and the influence of those techniques on the development of clostridial myositis or cellulitis. Usable responses were obtained from 439 veterinarians (75.2%). Of these, 414 used a new needle and syringe for each injection, 241 swabbed the site with a cleansing/disinfectant agent, and 242 swabbed the top of multidose injection bottles with a similar solution. Only 2 clipped the hair at the injection site. Twenty eight of the respondents reported that at least 1 horse developed a clostridial infection at the injection site following 1 of their injections. None of the various injection techniques had a significant influence on the development of clostridial infection at the injection site.

Animals↗

Sudden and unexpected death in horses and ponies: an analysis of 200 cases.

An analysis was made of the causes of death in horses and ponies over one year of age which died suddenly (Group 1) or were found dead but were considered normal when last seen (Group 2). There were 49 animals in Group 1. Thoroughbreds were overrepresented, but there were no ponies in this group. No cause of death was found in 30.6 per cent of cases and 16.3 per cent died from each of the following causes: haemorrhage in the respiratory system, central nervous system, and adverse drug reactions. Cardiovascular lesions were the cause of death in 14.4 per cent and the remaining 3.1 per cent had lesions of the gastrointestinal system. Racehorses mostly died suddenly from severe haemorrhage in various sites, particularly the thorax. In Group 2 there were 151 animals, and in 33.1 per cent no cause of death was determined. Gastrointestinal lesions were considered the cause of death in 39.2 per cent of cases and respiratory lesions killed 8.6 per cent. Lesions of both the central nervous system and cardiovascular system were considered the cause in 4.6 per cent of cases. The remaining 9.9 per cent of animals had miscellaneous lesions. Toxicological studies were performed in 46 of the total 200 cases, and only two had positive results; lead in one and nicotine in the other.

Age Factors↗

Immunofluorescence of bovine virus diarrhea viral antigen in white blood cells from experimentally infected immunocompetent calves.

A study to evaluate the detection of bovine virus diarrhea viral antigen using immunofluorescence testing of white blood cells was conducted. Five colostrum-deprived calves were inoculated intravenously with a cytopathic strain of the virus. Lymphocyte and buffy coat smears were prepared daily for direct immunofluorescent staining for detection of antigen. Lymphocytes were separated from heparinized blood using a Ficoll density procedure. Buffy coat smears were prepared from centrifuged blood samples collected using ethylenediaminetetraacetic acid as an anticoagulant. Bovine viral diarrhea virus antigen was detected by immunofluorescence between 3 and 11 days postinfection in lymphocyte smears and 3 to 12 days postinfection in buffy coat smears. Isolation of virus from both lymphocytes and buffy coat preparations correlated with detection of immunofluorescence. Serum neutralizing antibody to bovine virus diarrhea virus was detected on day 10 postinfection. Buffy coat smears were as sensitive as lymphocyte smears for the detection of antigen by immunofluorescence. It appeared that immunofluorescent staining of white blood cells was an effective method of detecting bovine virus diarrhea viral antigen.

Animals↗

The use of embryo collection techniques in Holstein heifers: A model to study early embryonic death.

Twenty-three cyclic Holstein heifers were purchased for use as embryo donors to study the effect of intrauterine exposure to Haemophilus somnus on the number, quality, and viability of embryos produced. Few problems were encountered using standard superovulation and nonsurgical embryo collection techniques on virgin heifers. Based on three or more ovulations, as determined by palpation per rectum of the ovaries at the time of embryo recovery, 28 of 30 heifers responded to the superovulation regimen. Of 29 nonsurgical recoveries, 27 produced one or more embryos. One hundred and seventy-six embryos and ova were collected from heifers synchronized, superovulated, and flushed 7 to 8 d after insemination.

Journal Article↗