A survey of mastitis pathogens including antimicrobial susceptibility in southeastern Australian dairy herds

The objectives for this study were to (1) describe the pathogen profile in quarters from cows with clinical mastitis and in cows with subclinical mastitis in southeastern Australia; and (2) describe antimicrobial susceptibility among isolated pathogens. As a secondary objective, we aimed to compare antimicrobial resistance prevalence in pathogens isolated from clinical and subclinical mastitis samples. A convenience sample of dairy herds (n = 65) from 4 regions in southeastern Australia (Gippsland, Northern Victoria, Tasmania, Western Victoria) were invited to submit milk samples from cows with clinical and subclinical mastitis over a 14-mo period (January 2011 to March 2012). Farmers were instructed to collect aseptic quarter milk samples from the first 10 cases of clinical mastitis for each month of the study. In addition, farmers submitted composite milk samples from cows with subclinical mastitis at 1 or 2 sampling occasions during the study period. Aerobic culture and biochemical tests were used to identify isolates. Isolates were classified as susceptible, intermediate, or resistant to a panel of antimicrobial agents based on the zone of growth inhibition around antimicrobial-impregnated disks, with antimicrobial resistance (AMR) classified as nonsusceptibility by combining intermediate and resistant groups into a single category. Generalized linear mixed models were used to compare the prevalence of AMR between clinical and subclinical mastitis isolates. For clinical mastitis samples (n = 3,044), 472 samples (15.5%) were excluded for contamination. Of the remaining samples (n = 2,572), the most common results were Streptococcus uberis (39.2%), no growth (27.5%), Staphylococcus aureus (10.6%), Escherichia coli (8.4%), and Streptococcus dysgalactiae (6.4%). For subclinical mastitis samples (n = 1,072), 425 (39.6%) were excluded due to contamination. Of the remaining samples (n = 647), the most common results were no growth (29.1%), Staph. aureus (29.1%), and Strep. uberis (21.6%). The prevalence of AMR among common isolates was low for the majority of antimicrobial agents. Exploratory analysis found that the probability of Staph. aureus demonstrating resistance to penicillin was 5.16 times higher (95% confidence interval: 1.68, 15.88) in subclinical isolates relative to clinical Staph. aureus isolates. A similar association was observed for amoxicillin with subclinical Staph. aureus isolates being 4.70 times (95% confidence interval: 1.49, 14.75) more likely to be resistant than clinical Staph. aureus isolates. We concluded that the most common bacteria causing clinical mastitis in dairy herds in Australia is likely to be Strep. uberis, whereas Staph. aureus is likely to be the most common cause of subclinical mastitis. Despite decades of antimicrobial use to control these organisms, AMR appears to be uncommon.

Impact of a single treatment of injectable doramectin on weight gain post weaning in beef heifers and steers in central Queensland, Australia

OBJECTIVES

To demonstrate the impact of a single drench with a label dose of injectable doramectin subsequent to weaning on the growth and performance of heifers and steers in central Queensland beef herds.

METHODS

Three studies were undertaken on recently-weaned Bos indicus-cross beef calves with ≥ 75% B. indicus content on two farms in central Queensland, just north of the Tropic of Capricorn. Farm 1 was located 50 km north and Farm 2 75 km north-west of Rockhampton. In each study, half of a group of recently-weaned beef calves were treated by random allocation with 0.2 mg/kg of injectable doramectin, and the remainder acting as untreated controls. Study 1 (Farm 1) enrolled 250 heifers, while studies 2 and 3 (Farm 2) both enrolled 200 steers and 200 heifers. The farms involved did not historically use macrocyclic lactone-based drenches on their cattle. There were varying periods of follow-up, with treated and control cattle pastured as one group throughout the study period. Worm burdens were monitored using standard faecal egg counts and larval differentiation procedures. In all studies, the worm genera present were a mix of Cooperia spp., Haemonchus spp. and Oesophagostomum spp.

RESULTS

In study 1, conducted on Farm 1 beginning 9 July 2012, doramectin-treated cattle gained an average of 0.27 kg/day while control cattle gained 0.19 kg/day over a monitoring period of 121 days (P < 0.0001). In study 2, conducted on Farm 2 beginning 28 July 2015, doramectin-treated cattle gained an average of 0.15 kg/day versus 0.145 kg/day in the control group (P = 0.44) over a 231-day study period. In study 3, conducted on Farm 2 beginning 4 August 2016, doramectin-treated steers and heifers gained an average of 0.431 and 0.402 kg/day versus 0.342 and 0.311 kg/day in the control group, respectively, over the first 91 days of the study (P < 0.0001 in both cases). The differences in average daily gain (ADG) in subsequent time periods were not statistically significant for steers or heifers. However, overall differences in ADG from day 0 remained statistically significant out to day 258, when the study ended for the heifers. By day 594, when the study ended for the steers, the difference in ADG was no longer significant.

CONCLUSION

Treatment with injectable doramectin soon after weaning resulted in improved weight gain in the 3 months after weaning in two of the three studies.

A seroepidemiological study of bovine pestivirus in Queensland beef and dairy herds conducted in 1994/95

OBJECTIVE

To describe the distribution and prevalence of cattle herds with detectable antibody to bovine pestivirus in Queensland in 1994/95.

MATERIALS AND METHODS

The study used 7,838 serum samples collected from 250 herds in Queensland, as part of a structured animal health surveillance program conducted in 1994 and 1995. Samples were collected from female cattle bred on the property. In each herd, 10 to 20 heifers less than two years of age and 10 to 15 older cows were sampled giving a 95% probability of detecting one or more seropositive animals if the seroprevalence was approximately 10% or greater. Sera were analysed for antibodies to bovine pestivirus using a virus neutralisation test.

RESULTS

Total cattle numbers in sampled herds varied from 62 to 24,600 head, while total area of properties sampled varied from 50 to 395,400 hectares. Eleven percent of herds contained no seropositive animals among those sampled, and in 38% of herds, all sampled cattle aged one to two years of age were seronegative. There was a trend for larger herds to have one or more animals seropositive for bovine pestivirus (chi-squared for Linear trend = 3.656, p = 0.056). Herds with more than 500 head of cattle were significantly more likely than herds with less than 500 head to contain one or more seropositive animals in any age group (prevalence ratio = 1.12; 95% confidence interval 1.01 - 1.23; p = 0.026). Age specific seroprevalence increased from around 10% in heifers, to between 75% and 85% in cows aged 10 years. The average annual incidence risk for bovine pestivirus infection varied from 0.12 to 0.24 seroconversions per cattle year at risk, and did not vary with age. The overall crude seroprevalence adjusted for herd size was 45%. There was a wide range of seroprevalence recorded for each level of stocking intensity.

CONCLUSIONS

This survey provides valuable baseline data on bovine pestivirus infection in Queensland cattle herds.

Detection of human papillomavirus in large cell neuroendocrine carcinoma of the uterine cervix: a study of 12 cases

AIM

To investigate the role of human papillomavirus (HPV) in large cell neuroendocrine carcinoma (LCNEC) of the uterine cervix.

METHODS

Twelve archival, immunohistochemically and/or electron microscopically confirmed cases of cervical LCNEC were studied. Non-isotopic in situ hybridisation (NISH) was performed on the formalin fixed, paraffin wax embedded biopsies using digoxigenin labelled probes to HPV types 6, 11, 16, 18, 31, and 33. The tumours were then subjected to polymerase chain reaction (PCR) analysis using GP5+/GP6+ consensus primers to the HPV L1 gene, in addition to type specific primers to the E6 and E6/E7 genes.

RESULTS

HPV-16 was detected by NISH and/or PCR in seven of the 12 carcinomas. Two additional tumours were HPV-18 positive by NISH and/or PCR. HPV DNA was not detected in the three remaining cases.

CONCLUSION

Integration of high risk HPV, in particular type 16 and to a lesser extent type 18, is associated with this uncommon variant of cervical carcinoma.

Carcinosarcoma of the uterine cervix: a report of eight cases with immunohistochemical analysis and evaluation of human papillomavirus status

Carcinosarcomas (malignant Müllerian mixed tumors [MMMTs]) of the uterine cervix are rare neoplasms. This report describes the morphology, immunohistochemical profiles, and human papillomavirus (HPV) status of eight cervical MMMTs. Patients' ages ranged from 32 to 93 years (mean, 61 years). Seven cases showed in situ squamous cell carcinoma (SCC). The invasive epithelial component (EC) was composed of combined adenoid basal carcinoma, basaloid SCC, and adenoid cystic carcinoma (ACC) in two cases. Keratinizing SCC, large cell nonkeratinizing SCC, undifferentiated carcinoma, and basaloid SCC predominated in the remaining tumors, one of which had admixed ACC. The sarcomatous component (SC) was homologous and spindled with admixed myxoid areas in three lesions. The ECs and SCs in six MMMTs showed dual immunostaining with epithelial membrane antigen and the pan-keratin marker, MNF116. The SC was vimentin-positive in seven cases. Five tumors had a vimentin-positive EC. The SC was positive for muscle specific actin and/or smooth muscle actin in seven lesions, of which four were desmin-positive. Polymerase chain reaction (PCR) using GP5+/GP6+ L1 consensus primers detected HPV DNA in all eight cases. Nonisotopic in situ hybridization with digoxigenin-labeled probes to HPV types 6, 11, 16, 18, 31 and 33 demonstrated integrated HPV 16 in three cases, not only in the EC, but also in nuclei of the SC. This is the first study to implicate HPV in the evolution of cervical MMMTs. The above observations lend support to a metaplastic theory of histogenesis.

Network 12 hepatitis B vaccination quality improvement program: an educational program directed at physicians, staff, and patients

Hepatitis B is easily spread via contact with infected blood. Hemodialysis patients and staff are particularly at risk for acquiring hepatitis B. Consequently, vaccination of hemodialysis patients and staff is strongly recommended. However, the vaccination rate among dialysis patients in this country remains below 50%. End-Stage Renal Disease (ESRD) Network 12 developed a quality improvement project directed at increasing patient vaccination by regular surveys, reports, and education of physicians, staff, and patients. Seventy-seven percent of facilities in the 4-state Network participated. Overall vaccination rate increased from 66.9% to 73.2% over 18 months (P <.05). The greatest improvement was seen among units with less than 60% of patients vaccinated initially, with mean facility vaccination rate increasing from 31.2 +/- 20.5% to 57.5 +/- 30.1% in the last available data period (P <.001). Only 3 of these 29 units failed to improve. The 90 units that had 60% to 97% vaccination rates initially improved significantly from 79.8 +/- 9.6% to 82.4 +/- 15% (P =.015). Three quarters of these units showed improvement. Only units with 100% vaccination deteriorated, but still maintained vaccination rates of 74.5 +/- 25.6%. An education-based quality improvement project can improve the hepatitis B vaccination rate of hemodialysis patients.

Sorghum ergot (Claviceps africana) associated with agalactia and feed refusal in pigs and dairy cattle

OBJECTIVE

To establish the aetiology and define the main clinical features of a syndrome characterised by severe feed refusal, death of piglets and reduced milk production in pigs and dairy cattle.

DESIGN

Clinical, pathological, toxicological and epidemiological examination of clinical cases in 10 piggeries and 4 dairies, located between 50 and 150 km south-west of Rockhampton.

RESULTS

All cases were associated with the feeding of sorghum grain infected with sorghum ergot (Claviceps africana). There was mild to severe feed refusal when the sorghum was first offered. Sows fed ergot before farrowing had shrunken udders, produced no colostrum, and displayed signs of oestrus. All of their piglets died, apparently from starvation: necropsy of a few piglets showed that they were born alive and walked, but had ingested no milk. Sows fed the grain after farrowing had severe reductions in milk production despite aggressive sucking by piglets, leading to very poor growth of piglets. There were no signs of infectious disease. Ergot in sorghum samples ranged from 1 to 31% ergot sclerotes by weight. Total alkaloid concentrations in mixed feeds ranged from 5 to 40 mg/kg, with dihydroergosine accounting for approximately 90%. At the same time, in the same districts, there were reports of feed refusal and reduced milk production from 4 dairy farms. Grain samples from these farms contained up to 17% C africana ergot sclerotia.

CONCLUSION

Agalactia and feed refusal are classical signs of poisoning by rye ergot (C purpurea), but this is the first time that sorghum ergot has been associated with a similar syndrome.

Adenoid cystic and adenoid basal carcinoma of the uterine cervix: comparative morphologic, mucin, and immunohistochemical profile of two rare neoplasms of putative 'reserve cell' origin

Adenoid cystic carcinomas (ACCs) and adenoid basal carcinomas (ABCs) are rare neoplasms of the uterine cervix that are currently regarded as distinct clinicopathologic entities. Accurate distinction between ABCs and ACCs is of clinical importance because of differences in their biological behavior. This study compares the morphologic, mucin, and immunohistochemical profiles of 18 cervical ACCs, 8 ABCs, and 1 combined ABC-ACC. Serial sections from the 27 cases were stained with hematoxylin and eosin, periodic acid-Schiff-diastase, mucicarmine, and alcian blue and subjected to a panel of immunoperoxidase markers, namely, MNF116, CAM 5.2, CK7, CK20, epithelial membrane antigen, carcinoembryonic antigen (CEA), S-100, HHF 35, laminin, and type IV collagen. One ACC was also examined ultrastructurally. Almost all patients were postmenopausal black women. The distinction between ABC and ACC was best made morphologically. Divergent epithelial differentiation was seen in 18 cases (11 ACCs, 6 ABCs, and 1 ABC-ACC). Six cases with intact surface epithelium showed a high grade squamous intraepithelial lesion. There was no significant difference in mucin staining. Both tumor types had a similar immunohistochemical profile, apart from type IV collagen and laminin staining, which occurred exclusively in relation to the extracellular basement membranelike material in the ACC. Eleven ACCs and three ABCs were S-100-positive, including the respective ACC and ABC components of the combined ABC-ACC. Eight of the S-100-positive neoplasms with ACC morphology also stained with HHF 35, suggesting myoepithelial differentiation. The latter was confirmed in one ACC examined ultrastructurally. The similar clinical profiles, apart from the different biological behavior, capacity for divergent differentiation, and the occurrence of ABC areas in some ACCs and vice versa suggest that these tumors may share a common histogenesis, forming part of a morphologic and biologic spectrum of basaloid cervical neoplasms of putative "reserve cell" origin. Circumstantial evidence suggests that ABC may be a precursor of cervical ACC.

Effect of head position on vertical mandibular opening

STUDY DESIGN

A within-subjects repeated measures design.

OBJECTIVES

To determine differences in the amount of vertical opening of the mandible among 3 different head positions.

BACKGROUND

Results from several studies have suggested that the position of the head and neck may affect temporomandibular joint function. Presently no standardized position of the head and neck has been recommended for measuring vertical opening of the mandible.

METHODS AND MEASURES

Twenty males and 20 females (32.9 +/- 8.3 years) participated in the study. We obtained 3 measurements of vertical mandibular opening using a millimeter ruler on each subject in the forward, neutral, and retracted head positions.

RESULTS

A 1-way repeated measures analysis of variance followed by pairwise comparisons indicated that the vertical mandibular opening was significantly greater in the forward head position (44 +/- 5.3 mm) than in the neutral head position (41.5 +/- 4.8 mm) and in the retracted head position (36.2 +/- 4.5 mm). In addition, vertical mandibular opening was significantly greater in the neutral head position than in the retracted head position. Interclass correlation coefficients for the 3 head positions ranged from 0.90 to 0.97 for intrarater, interrater, and day-to-day reliability.

CONCLUSIONS

Head position is an important factor in determining the amount of vertical mandibular opening in healthy adults.

Outbreak of fibrinous pneumonia in recently weaned beef calves in southern Queensland

OBJECTIVE

To describe an outbreak of fibrinous pneumonia in 331 recently weaned beef calves on two properties in the Miles district in southern Queensland. DESCRIPTION OF THE HERD: The affected calves came from three groups: 88 recently weaned calves purchased at Casino NSW saleyards on 29 April 1994, 91 recently weaned calves purchased at Inverell NSW saleyards on 11 May 1994 and 152 homebred calves weaned on 18 May 1994 off the owner's cows. All calves were Hereford and Hereford cross.

INVESTIGATION

The two groups of purchased calves (the Casino-Inverell weaners) were mixed together and moved to another recently purchased property on May 19 after handling on May 18. The homebred weaners were not mixed with the Casino-Inverell weaners, but had nose-to-nose contact for one night via a 3 m gateway while yarded on May 18. By May 25, an outbreak of acute undifferentiated bovine respiratory disease was evident among all 331 calves and two were dead. The morbidity risk in all three groups was 90%, suggesting the three groups of calves were equally susceptible. Five calves died during the outbreak, giving a crude mortality rate of 1.5% (5/331), with necropsy of three calves showing they died of fibrinous pneumonia. Treatment of all calves with a single injection of 20 mg/kg of long acting oxytetracycline lead to rapid clinical improvement in affected calves, and appeared to prevent further mortality. Mortality clustered, with three of the four dead purchased calves coming from one vendor of the Inverell sale.

CONCLUSIONS

Fibrinous pneumonia can occur after weaning in beef calves in Australia. It is highly contagious among groups of recently weaned calves.

Adenoid basal carcinoma of the uterine cervix: detection of integrated human papillomavirus in a rare tumor of putative "reserve cell" origin

This study investigated the role of human papillomavirus (HPV) in adenoid basal carcinoma, a rare neoplasm of the uterine cervix. Nine archival paraffin-embedded tumors were analyzed with non-isotopic in situ hybridization (NISH) for HPV types 6, 11, 16, 18, 31, and 33 using digoxigenin-labelled probes. The polymerase chain reaction (PCR) was performed on each of the cases using E6 consensus primers to HPV. A total of 67% of adenoid basal carcinomas harbored the HPV genome with NISH, of which 3 were PCR-positive. Integrated HPV 16 DNA was demonstrated in 4 of the 6 NISH positive cases. Two cases showed integrated HPV 33. HPV DNA was not detected in the three remaining cases. These results show that the integrated high-risk HPV, in particular type 16, is associated with this uncommon cervical tumor.

Sickness, mortality and the buller steer syndrome in a western Canadian feedlot

OBJECTIVE

To determine if an association existed between sickness, mortality and bullers in a western Canadian feedlot.

DESIGN

A retrospective epidemiological study.

ANIMALS

78,445 male cattle that entered a 24,000-head feedlot in western Canada from 1991 to 1993.

PROCEDURE

Animal health records for bullers were collected and analysed to see if they were at greater risk of sickness and mortality than other steers, and to see if pens with a high prevalence of bullers also had a high prevalence of sickness and mortality.

RESULTS

The prevalence of bullers increased with increasing age of cattle on arrival at the feedlot (R = 0.36; P < 0.001). Sickness and mortality decreased with increasing age of cattle on arrival. However, sickness and mortality in bullers relative to other steers actually increased with increasing age on arrival suggesting an interaction existed between sickness and bullers. Bullers were significantly (P < 0.05) more likely to get sick and to die than other steers. In all cases, there was a strong temporal association between sickness and bullers, with sickness and bullers mostly occurring within the first 30 days of the feeding period. On average, pens of cattle with a high prevalence of bullers did not have a correspondingly high prevalence of sickness or mortality.

CONCLUSION

This study suggests that sickness is an effect modifier of dominance behaviour and therefore bullers in feedlot steers. Bullers should always be checked for signs of sickness and treated accordingly. Further research is needed to investigate the effects of sickness on dominance behaviour in pens of feedlot cattle.

Performance, survival, necropsy, and virological findings from calves persistently infected with the bovine viral diarrhea virus originating from a single Saskatchewan beef herd

Fifty-one calves from 652 cows and heifers that calved on a Saskatchewan ranch in 1992 were identified as persistently infected with bovine viral diarrhea virus (BVDV), based on virological and necropsy findings. Herd records suggested a further 20 calves that died between birth and weaning were probably also persistently infected. Subsequent to weaning, all surviving persistently infected calves were transferred to one pen in a 10,000 head commercial feedlot, to mimic normal management practice in western Canadian beef herds. On average, when compared with healthy, BVDV-negative herdmates, persistently infected calves were "poor doers" and had poor survivability, with only 4 persistently infected calves surviving to 1 year of age. There was no difference (P > 0.05) in survival between male and female persistently infected calves. The clinical, pathological, and virological findings from these persistently infected calves varied over time. The majority of persistently infected calves had gross pathological lesions at necropsy, consistent with mucosal disease. However, approximately 25% of the persistently infected calves had gross pneumonic lesions at necropsy, with no or only mild lesions of mucosal disease. A wide variety of other lesions were also noted in persistently infected calves at necropsy. Therefore, the possibility that BVDV-induced lesions can be misdiagnosed is very real. The results of this study indicate that persistent infection with BVDV should always be considered in calves with chronic ill thrift, chronic enteritis, or respiratory disease.

Losses over a 2-year period associated with fetal infection with the bovine viral diarrhea virus in a beef cow-calf herd in Saskatchewan

In 1992, significant calf losses occurred between birth and weaning in a 650-cow Saskatchewan beef herd. These losses occurred subsequent to ill-thrift and disease, and every calf necropsied was found to be persistently infected with bovine viral diarrhea virus (BVDV). The objectives of this study were to describe the losses associated with fetal infection with BVDV in this herd and to determine why they occurred. For investigative purposes, blood samples were collected from the entire cow herd and the surviving calves at pregnancy testing in 1992, and tested by virus isolation for BVDV. Between 51 and 71 persistently infected calves were born in 1992. Bovine viral diarrhea virus was only isolated from calves. The only confirmed fetal infections with BVDV were recorded as the birth of persistently infected calves. However, abortions, reduced pregnancy rates, and delayed calvings were also recorded in the cow herd and may have been the result of fetal infections. The herd was monitored again in 1993. Fetal infections with BVDV were recorded as the birth of stunted, deformed, and persistently infected calves. The greatest losses due to fetal infection with BVDV in the 2 years of this study occurred in cows that were 3-years-old at calving (second calves). Bovine viral diarrhea virus appears to have remained endemic in this herd by transmission from persistently infected calves on young 3- and 4-year-old cows to naive calved 2-year-old cows that were mingled with them annually for rebreeding. Significant numbers of the 2-year-old cows remained naive to BVDV, because they were segregated from persistently infected calves at weaning, preventing cross-infection with BVDV.

Epidemiological investigation of the buller steer syndrome (riding behaviour) in a western Canadian feedlot

OBJECTIVE

To describe the buller steer syndrome in a Western Canadian feedlot.

DESIGN

a retrospective study.

ANIMALS

78,445 male cattle that entered a 24,00-head feedlot in western Canada from 1991 to 1993.

PROCEDURE

All cattle were given a hormonal growth promotant containing 20 mg oestradiol benzoate and 20 mg progesterone within 24 h of arrival at the feedlot. A 'buller' was a steer that was observed at daily pen checking to be ridden persistently by pen mates or had evidence of having been persistently ridden by pen mates. At the completion of the feeding period, animal health records for bullers were collected and analysed.

RESULTS

The prevalence of bullers in the total population was 2,139/78,445 (2.7%, range per pen 0 to 11.2%). The prevalence of bullers increased with increasing weight and age. The relapse risk after first treatment (three days in the feedlot hospital plus treatment for concurrent disease) was 30% on average (27 to 35%). Individual records from 9,734 yearling steers that entered the feedlot in 1991 and 1992 showed that bullers were significantly (P < 0.05) heavier at processing than non-bullers. Bullers occurred as a point source epidemic with a cause occurring soon after cattle arrived at the feedlot and were mingled into pen grous. This gave a 'days on feed' distribution. The peak incidence of bullers occurred much sooner after arrival and dropped off much quicker in older cattle. The daily incidence of bullers was temporal, but was not related to season of the year, weather condition of any other feedlot management practice. It was related to the seasonal arrival of cattle at the feedlot, their age at entry to the feedlot and the post arrival occurrence of bullers. Reimplantation with hormonal growth promotants and castration of intact bulls did not produce an epidemic of bullers.

CONCLUSIONS

The findings of this study support the theory that bullers are the result of agonistic interactions, which occur concurrent with the establishment and maintenance of a social hierarchy with pens of feedlot cattle.

The prevalence of bovine viral diarrhea virus infection in a population of feedlot calves in western Canada

The prevalence of bovine viral diarrhea virus (BVDV) infection was examined in a population of 5129 recently weaned steer calves entering a large feedlot in central Saskatchewan from September to December 1991. Serum samples were collected within 24 h of arrival at the feedlot from every fifth calf processed and again 96 d postarrival. A microtiter virus isolation test was used to determine the prevalence of calves viremic with BVDV on entry to the feedlot. An enzyme-linked immunosorbent assay (ELISA) which detects antibody against glycoprotein 53 of the BVDV was used on paired sera to determine the seroconversion risk during the first 96 d in the feedlot. A virus neutralization (VN) test for BVDV was conducted on a sub-sample of paired sera to measure agreement in determination of seroconversion risk with the ELISA. A polymerase chain reaction (PCR) test which detects BVDV was used to determine if cattle were acutely viremic when treated for disease. The estimated prevalence of persistently infected calves in this population was < 0.1%. The seroconversion risk for BVDV was 27% (236/864) according to the ELISA and it varied from 0 to 63% among the 20 pens sampled. According to the VN test, the seroconversion risk for BVDV was 40% (132/327) and it varied from 0 to 100% among the 11 pens tested. The agreement between the ELISA and VN tests in seroconversion risk to BVDV was very poor (kappa = 0.15 +/- 0.039 SE). The prevalence of acute viremia in calves treated at the feedlot hospital was low at 4% (6/149).(ABSTRACT TRUNCATED AT 250 WORDS)

Intracytoplasmic inclusions in benign prostatic epithelium

Prostatic glandular tissue in man is associated with varying forms of acellular structures. These include corpora amylacea, as well as more recently described prostatic crystalloids. We describe, for the first time to our knowledge, intracytoplasmic inclusions in benign prostatic epithelial cells of the central and transition zones of the prostate gland. Despite extensive histochemical, immunohistologic, and electron microscopic investigation, the exact nature of these inclusions remains obscure.

Investigation of an outbreak of mucosal disease in a beef cattle herd in southwestern Saskatchewan

This study describes the epidemiological investigation of an outbreak of mucosal disease that occurred on a ranch in southwestern Saskatchewan. Over a six month period during the fall and winter of 1991-1992,in a herd of 515 beef cattle and 96 bison, 20 yearling cattle from a group of 105 housed in one feedlot pen died from mucosal disease. A further eight yearlings were slaughtered for salvage because they were at risk of dying from mucosal disease. Mucosal disease mortalities were the first observed evidence of fetal infections with bovine viral diarrhea virus in this herd. Animals that died from mucosal disease exhibited signs of ill thrift prior to death. Deaths from mucosal disease were confined to the progeny of one herd of beef cows. Following an outbreak of fetal infection with bovine viral diarrhea virus during 1989-1990, at least 28 (22%) of the 128 calves born from this herd of cows in the spring of 1990 were persistently infected with bovine viral diarrhea virus. However, only one calf born from this herd in 1991, and five calves born from all herds in 1992 were persistently infected. Of the five persistently infected calves born in 1992, three were born to persistently infected replacement heifers born in 1990. These heifers calved without assistance in 1992, but only one of their calves survived past three days of age, and it was persistently infected. In January 1992, 82% of the total herd had reciprocal antibody titers to bovine viral diarrhea virus of >/=1024 which suggested a high level of herd immunity to bovine viral diarrhea virus. Thus, following the outbreak of fetal infection with bovine viral diarrhea virus in 1989-1990, herd immunity to bovine viral diarrhea virus had developed rapidly in the breeding cows and heifers. Subsequently, in the next two years, there was a dramatic decline in the number of calves born persistently infected with bovine viral diarrhea virus.

The neuroendocrine cell population of the human prostate gland

Neuroendocrine cells have been reported in up to 50% of all prostatic adenocarcinomas. These cells appear to influence the prognosis of these tumors. The distribution of the neuroendocrine cell population in the normal prostate gland, through all stages of development, has not been documented previously. We define the distribution of this cell population and describe 4 cellular morphological variants. The neuroendocrine cells of the peripheral zone appear to respond to factors present at birth and at puberty, while those of the periurethral glands and prostatic duct system are not influenced by this factor. It is postulated that this factor may be the levels of circulating androgens. The presence of at least 2 functionally distinct populations of neuroendocrine cells raises the possibility of 2 different embryonic origins. The study documents the distribution of calcitonin-producing cells but fails to detect the presence of somatostatin.