A prospective study was carried out on 845 heifer calves born during 1991 on 30 Holstein dairy farms in southeast Minnesota. The objectives of the study were to describe the epidemiology of morbidty and mortality in dairy calves from birth to 16 weeks of age (with an emphasis on respiratory disease), to examine individual calf and herd management practices as risk factors for calf morbidity and mortality, and to validate producer diagnosis of mortality. Incidence rates for all morbidity, enteritis, and pneumonia were 0.20, 0.15, and 0.10 cases per 100 calf-days at risk for the period of the study. Risk of enteritis was highest in the first 3 weeks of life, with pneumonia risk highest at 10 weeks of age. Case fatality rates averaged 11.8%, 17.9%, and 9.4% for all diagnoses, enteritis, and pneumonia, respectively. Average daily rates of gain from birth to 16 weeks Iof age differed between farms that had inadequate calf housing (0.8 kg day-') versus those with adequate calf housing (1.0 kg day-i). Approximately half of the calves in the cohort (418) had blood samples taken monthly from birth until 16 weeks of age. Of the calves sampled, only 19 c,alves showed a four-fold rise in serum titers to respiratory viruses. Sixteen calves seroconverted to BVDV, two calves to IBRV, and one calf to PI3 virus. Of 98 calves less than 10 days of age tested for adequacy of passive transfer, 35 (35.7%) had serum immunoglobulin levels of less than 800 mg dl-'. There were no significant differences in mortality or morbidity between calves that had adequate passive transfer and those that did not. The incidence of mortality was 0.08 deaths per 100 calf-days at risk; 64 calves died during the 16 months of the study. The risk of death was highest at 2 weeks of age. Enteritis was the most common cause of death (28 deaths, 44% of all deaths) followed by pneumonia (19 deaths, 30% of all deaths). Comparing producer diagnosis of mortality with necropsy results yielded sensitivities of 58.3% and 56% and specifici-* Corresponding author at: Minnesota Veterinary Hospital, 4545 Hodgson Road, Saint Paul, MN 55126, USA. Tel: -I-l-61 2-484333 1. Elsevier Science B.V. SSDl 0167.5877(95)01000-9 156 N.J. Siuula et al./ Preventiue Veterinary Medicine 27 (I 996) 155-l 71ties of 93% and 100% for producer diagnoses of enteritis and pneumonia, respectively. The kappa statistic comparing producer diagnosis with necropsy result was 0.47. The most common pathogens isolated from calves that died of enteritis were rotavirus (five calves), and Escherichia coli (four calves). Pathogens isolated from pneumonic lungs included Pasteurella multocida (three calves), Haemophilus somnus (three calves), and Pasteurella haemolytica (one calf). NJ. Sivula et al./PreoentiueVeterinary Medicine 27 (19%) 155-171 157

Abstract. Out of 45 cases of fatal chronic pneumonia in calves examined for Mycoplasma bovis infection from February to July 1994, 11 cases with pulmonary abscesses that were culture positive for M. bovis were encountered. The cases were studied in detail using a recently developed monoclonal antibody-based immunoperoxidase technique. Mycoplasma bovis organisms were detected in specific locations at all stages of abscessation observed. In bronchioles or terminal airways within which abscesses developed, M. bovis was located at the epithelial surface and in close association with infiltrating neutrophils and macrophages. Abscessed airways that had lost the epithelium were encapsulated and were seen as coagulative necrotic foci that stained intensely for M. bovis, especially at the periphery. Some foci stained weakly and such might have been resolving lesions. Mycoplasma bovis was also demonstrated at sites of mild mononuclear cell infiltration in the livers and kidneys of 2 calves. The mycoplasma was detected within bile ducts in the liver and in the tubular epithelium of the kidney. Abscesses not staining for M. bovis, presumably caused by other pathogens, were seen concurrently with M. bovis-associated abscesses in some lungs. Thirteen other M. bovis-positive cases showed no abscesses, possibly indicating heterogeneity among M. bovis strains. Three other cases with abscesses were negative for M. bovis by culture and immunoperoxidase staining. The monoclonal antibody-based immunohistochemical technique is efficient for specific detection of M. bovis in cases of enzootic pneumonia of calves with or without abscessation. Mycoplasma bovis is implicated in the pathogenesis of lung abscesses in some calves.Naturally occurring infectious pneumonias of clinical significance usually have complex causes, often requiring the interaction of two or more organisms and predisposing environmental factors.2 Calf pneumonia resistant to antibiotic therapy is frequently encountered in the United States of America and Canada. 10 In areas where calves dying of chronic pneumonia would normally have been treated for bacterial agents, diagnostic effort is necessarily geared towards elucidating the role of viruses and mycoplasmas. Viral agents often cause acute pneumonia in calves, with a histological picture of bronchointerstitial pneumonia. 2Among bovine mycoplasmas recognized in the USA, Canada, and Europe, Mycoplasma bovis stands out as the most invasive and destructive. This mycoplasma can cause pneumonia and arthritis in calves and mastitis in adult cattle .2,7 Mycoplasma bovis has also been cultured from blood.11 There are studies in which M. Received for publication October 7, 1994. bovis was inoculated into calves concurrently with Pasteurella hemolytica, 3 respiratory syncytial virus, 11 and bovine viral diarrhea virus and P. hemolytica. 8 Lesions produced by M. bovis alone were described as focal areas of coagulative necrosis surrounded by mononuclear cells and suppurative bronchiolitis with varying degrees of lympho...

Glutathione S-transferase (GST, E.C. 2.5.1.18) comprises a family of isoenzymes that play a key role in the detoxification of such exogenous substrates as xenobiotics, environmental substances, and carcinogenic compounds. At least five mammalian GST gene families have been identified to be polymorphic, and mutations or deletions of these genes contribute to the predisposition for several diseases, including cancer. The gene cluster of GSTM1–GSTM5 has been reported to be localized on chromosome 1p and spans a length of nearly 100 kb. One mutation of the GSTM3 gene generates a recognition site for the transcription factor yin yang 1. As a result of this mutation, the expression of GSTM3 can be influenced. The mutated GSTM3 gene has been reported to be involved in increased susceptibility for the development of cancer, but no information is available concerning its role in bladder cancer. We have identified patients with a heterozygous GSTM3 geno- type who carry a significantly increased risk for the development of bladder cancer. Here we report that the mutation of intron 6 of GSTM3 increases the risk for bladder cancer (odds ratio: 2.31; 95% confidence interval [CI], 1.79–2.82). We developed a procedure to identify heterozygous or homozygous carriers of the GSTM1 alleles. Heterozygous carriers of the GSTM1 null genotype have a significantly elevated risk of developing bladder cancer. We calculated an odds ratio of 3.54 (95% CI, 2.99–4.11) for this genotype. These observations lead to the assumption that the lack of detoxification by glutathione conjugation predispose to bladder cancer when at least one of two alleles is affected. Furthermore, individuals presenting the homozygous wild type of GSTM1 and GSTM3 are significantly protected against bladder cancer.

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