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The obesity epidemic in developed societies has led to increased cardiovascular diseases including pulmonary hypertension associated with left heart disease (PH-LHD), the largest and fastest-growing class of PH. Similar to obese humans, PH and heart failure (HF) are increasingly recognized in North American fattened beef cattle. We hypothesized that PH and HF in fattened beef cattle are novel, phenotypically distinct manifestations of bovine PH arising from left ventricular (LV) dysfunction similar to obesity-related PH-LHD in humans. We conducted a semi-quantitative histopathological assessment of cardiopulmonary tissues obtained from fattened beef cattle suffering end-stage HF compared to asymptomatic cattle of equivalent age undergoing the same fattening regimens. In HF animals we observed significant LV fibrosis, abundant cardiac adipose depots, coronary artery injury, and pulmonary venous remodeling recapitulating human obesity-related PH-LHD. Additionally, striking muscularization, medial hypertrophy, adventitial fibrosis, and vasa vasorum hyperplasia in the pulmonary arterial circulation were associated with sequela of pathologic right ventricular (RV) remodeling suggesting combined pulmonary venous and arterial hypertension. The association between obesity, pathologic cardiopulmonary remodeling, and HF in fattened beef cattle appears to recapitulate the complex pathophysiology of obesity-associated PH-LHD in humans. This novel, naturally occurring, and large animal model may provide mechanistic and translational insights into human disease.

Background: Shockwave treatment is increasingly used for plantar fasciitis and Achilles tendinopathy. To be effective it is believed that high pressure must be achieved in the tissues. We report on the first human cadaveric experiments to characterize pressure from radial shockwave therapy (rSWT) for plantar fasciitis., Methods: The pressure from rSWT was measured in two cadaveric feet using a needle hydrophone. Maximal pressure and energy flux were calculated from the measurements., Results: The pressure persisted longer than supposed, for up to 400μs. The peak negative pressure was up to two Mega Pascal. The predicted energy in the tissue strongly depended on the time interval used in calculations., Conclusions: The measured pressure may be sufficiently high to cause cavitation in the tissue, which is one of the proposed healing mechanisms associated with rSWT. The results suggest that the energy is imparted to the tissues for much longer than previously thought., (Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.)

Spatial patterning of cells is of great importance in tissue engineering and biotechnology, enabling, for example the creation of bottom-up histoarchitectures of heterogeneous cells, or cell aggregates for in vitro high-throughput toxicological and therapeutic studies within 3D microenvironments. In this paper, a single-step process for creating peelable and resilient hydrogels, encapsulating arrays of biological cell aggregates formed by negative DEP has been devised. The dielectrophoretic trapping within low-energy regions of the DEP-dot array reduces cell exposure to high field stresses while creating distinguishable, evenly spaced arrays of aggregates. In addition to using an optimal combination of PEG diacrylate pre-polymer solution concentration and a novel UV exposure mechanism, total processing time was reduced. With a continuous phase medium of PEG diacrylate at 15% v/v concentration, effective dielectrophoretic cell patterned arrays and photo-polymerisation of the mixture was achieved within a 4 min period. This unique single-step process was achieved using a 30 s UV exposure time frame within a dedicated, wide exposure area DEP light box system. To demonstrate the developed process, aggregates of yeast, human leukemic (K562) and HeLa cells were immobilised in an array format within the hydrogel. Relative cell viability for both cells within the hydrogels, after maintaining them in appropriate iso-osmotic media, over a week period was greater than 90%., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Producer reports from ranches over 2,438 meters in southwest Colorado suggest that the mortality of preweaned beef calves may be substantially higher than the national average despite the selection of low pulmonary pressure herd sires for over 20 years. Diagnostic investigations of this death loss problem have been limited due to the extensive mountainous terrain over which these calves are grazed with their dams. The objective of the current study was to determine the causes of calf mortality on 5 high-altitude ranches in Colorado that have been selectively breeding sires with low pulmonary pressure (<45 mmHg) for over 20 years. Calves were followed from branding (6 weeks of age) in the spring to weaning in the fall (7 months of age). Clinical signs were recorded, and blood samples were taken from sick calves. Postmortem examinations were performed, and select tissue samples were submitted for aerobic culture and/or histopathology. On the principal study ranch, 9.6% (59/612) of the calves that were branded in the spring either died or were presumed dead by weaning in the fall. In total, 28 necropsies were performed: 14 calves (50%) had lesions consistent with pulmonary hypertension and right-sided heart failure, and 14 calves (50%) died from bronchopneumonia. Remodeling of the pulmonary arterial system, indicative of pulmonary hypertension, was evident in the former and to varying degrees in the latter. There is a need to better characterize the additional risk factors that complicate pulmonary arterial pressure testing of herd sires as a strategy to control pulmonary hypertension.

Dielectrophoresis (DEP) has been used for many years for the analysis of the electrophysiological properties of cells. However, such analyses have in the past been time-consuming, such that it can take 30 min or more to collect sufficient data to make valid interpretations from a single DEP spectrum. This has limited the application of the technology to a rapid tool for non-invasive, label-free research in areas from drug discovery to diagnostics. In this paper we present the development of a programmable, multi-channel DEP system for rapid biophysical assessment of populations of biological cells. A new assay format has been developed for continuous near-real-time monitoring, using simultaneous application of up to eight alternating current electrical signals to independently addressable dot microelectrodes in an array format, allowing a DEP spectrum to be measured in 20 s, with a total cycle time between measurements of 90 s. To demonstrate the system, human leukaemic K562 cells were monitored after exposure to staurosporine and valinomycin. The DEP response curves showed the timing and manner in which the membrane properties changed for the actions of these two drugs at the early phase of induction. This technology shows the great potential for increasing our understanding of the role of electrophysiology in drug action, by observing the changes in electrical characteristics as they occur., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Dairy cow mortality levels in the United States are excessive and increasing over time. To better define cause and effect and combat rising mortality, clearer definitions of the reasons that cows die need to be acquired through thorough necropsy-based postmortem evaluations. The current study focused on organizing information generated from postmortem evaluations into a monitoring system that is based on the fundamentals of conceptual modeling and that will potentially be translatable into on-farm relational databases. This observational study was conducted on 3 high-producing, commercial dairies in northern Colorado. Throughout the study period a thorough postmortem evaluation was performed by veterinarians on cows that died on each dairy. Postmortem data included necropsy findings, life-history features (e.g., birth date, lactation number, lactational and reproductive status), clinical history and treatments, and pertinent aspects of operational management that were subject to change and considered integral to the poor outcome. During this study, 174 postmortem evaluations were performed. Postmortem evaluation results were conceptually modeled to view each death within the context of the web of factors influencing the dairy and the cow. Categories were formulated describing mortality in terms of functional characteristics potentially amenable to easy performance evaluation, management oversight, and research. In total, 21 death categories with 7 category themes were created. Themes included specific disease processes with variable etiologies, failure of disease recognition or treatment, traumatic events, multifactorial failures linked to transition or negative energy balance issues, problems with feed management, miscellaneous events not amenable to prevention or treatment, and undetermined causes. Although postmortem evaluations provide the relevant information necessary for framing a cow's death, a restructuring of on-farm databases is needed to integrate this level of detail into useful monitoring systems. Individual operations can focus on combating mortality through the use of employee training related to postmortem evaluations, detailed forms for capturing necropsy particulars and other relevant information related to deaths, and standardized nomenclature and categorization schemes. As much as anything, the simple act of recognizing mortality as a problem might be the most fundamental step toward controlling its progression., (Copyright 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

In this paper, the use of non-uniform ac electric fields on biological cells for bioanalysis, through multiple, independently configurable channels is presented. The programmable system has been used to obtain the dielectrophoretic spectra of cells in near real time, within 90 seconds. This is a significant improvement on existing dielectrophoretic techniques as simultaneous parallel measurement of the dielectrophoretic forces at different frequencies has potential of revealing subtle changes to the electrophysiology of cells, as they occur. The results show that with continuous on-chip monitoring, cells exposed to a chemical agent that induces apoptosis begin to exhibit a spectrum that differs from untreated cells, as indicated from shifts in the observed crossover frequency values.

Increasing levels of dairy cow mortality pose a challenge to the US dairy industry. The industry's current understanding of dairy cow mortality is reliant upon descriptions largely based on producer or veterinary assumptions regarding cause of death without the benefit of detailed postmortem evaluations. A thorough necropsy is a superior tool for establishing a cause of death, except for cases involving euthanasia for traumatic accidents or severe locomotor disorders. Information provided from a necropsy examination would be most valuable if it were categorized and combined with cow health information in a complete postmortem evaluation designed to guide future management decisions. The objective of this study was to describe dairy cow deaths on a Colorado dairy over a 1-yr period and explore classification systems for necropsy findings that might inform management actions aimed at reducing dairy cow mortality. Throughout the study period a thorough necropsy examination was performed on every cow that died. Based upon this examination each death was characterized by a proximate cause (i.e., the most likely immediate cause of the death). Each proximate cause of death was then categorized using 3 alternate schemes founded on generalized etiologic principles and influenced by previous clinical history and treatments. These schemes included the broad categories commonly used for classifying findings within a review of literature related to dairy cow mortality, a diagnostic scheme used within the problem-oriented veterinary medical record, and an analysis focusing on the primary physiologic system derangement for each death. A total of 2,067 cows were enrolled during the study period of which 1,468 cows freshened, 507 cows were sold, and 94 cows died, resulting in a mortality risk of 6.4 deaths per 100 lactations at risk. The distribution of deaths by parity was significantly different from the herd distribution at the end of study with the largest percentage of death present in parity > or =4. Postmortem findings attributable to a specific cause of death were present for all but 4 of the 94 deaths. Assignment of the proximate causes of death to categories within the 3 alternate schemes provided a means for classifying necropsy findings and causes of death with different levels of detail. Creating categories with more selective groupings may provide a means for capturing specifics related to deaths that can be used to guide management decisions.

Disseminated infection (DI) of Mycobacterium avium subspecies paratuberculosis (MAP) in cattle may impair cow health, potentiate spread of disease, and is a potential food-safety risk. The objectives of this study were to determine the association between severity of histologic enteric lesions and the occurrence of DI, clinical signs, and positive fecal culture and serum ELISA results. Bacteriologic fecal culture and serum ELISA were performed on 40 dairy cows from MAP-infected herds. Cows were classified as having DI if MAP was isolated from any of 11 extra-intestinal tissues collected postmortem. A grade of 0-3, corresponding to the severity of histologically evident granulomatous inflammation was determined for sections of ileum, jejunum, mesenteric lymph node, and ileocolic lymph node. An overall intestinal inflammation (OII) grade of 0-3 was assigned to each cow. The proportion of cows with DI increased with tissue-specific lesion grade and OII grade. All cows with grade 3 inflammation in any single tissue had DI, however, some cows with DI had grade 1 inflammation or no lesions. In general, there was a positive association between OII grade and clinical signs, gross enteric lesions, and positive ELISA and fecal culture results. However, 12% of OII grade 0 cows had clinical signs (explained by other conditions recognized with necropsy), and the proportion of positive ELISA results was lower for OII grade 3 cows relative to grade 2 cows. Although MAP dissemination may occur early in the disease process, histopathology of intestinal tissues may be used to detect a substantial proportion of DI cows.

Mycobacterium avium subspecies paratuberculosis (MAP) disseminated infection in dairy cattle affects animal health and productivity and is also a potential public health concern. The study objectives were to characterize MAP disseminated infection in dairy cattle and to determine the role of antemortem tests in detecting cattle with disseminated infection. Forty culled dairy cows representing a variety of serum enzyme-linked immunosorbent assay (ELISA) results and body conditions were selected for the study. The physical condition of the cows was assessed via clinical examination prior to euthanasia and blood and feces were collected and tested by serum ELISA and fecal culture, respectively. Fifteen tissues were aseptically collected from each cow during necropsy and cultured for isolation of MAP. Disseminated infection was diagnosed when MAP was isolated in tissues other than the intestines or their associated lymph nodes (LNs) and was distinguished from infection found only in the gastrointestinal tissues and from absence of infection. Of the 40 cows in the study, 21 had MAP disseminated infection. Results showed that 57% (12/21) of cows with disseminated infection had average to heavy body condition and no diarrhea. Cows with disseminated infection had no to minimal gross pathologic evidence of infection in 37% (8/21) of cases. Only 76% (16/21) of cows with disseminated infection had positive historical ELISA results and only 62% (13/21) had a positive ELISA at slaughter. Thus, antemortem evidence of MAP infection was lacking in a high proportion of cows where MAP disseminated infection was confirmed.

A postpartum mare and foal were presented for evaluation of fever and lethargy in the mare. The mare was diagnosed with endometritis and initially responded well to treatment. On the second day of hospitalization, the mare developed renal insufficiency characterized by oliguria, azotemia, hemolysis, and thrombocytopenia. Concurrently, the foal developed rapidly progressive central nervous system signs culminating in refractory seizures. Both animals failed to respond to treatment and were euthanized. Thrombotic microangiopathy involving glomeruli was evident on microscopic examination of the mare's kidneys. Microscopic evidence of brain edema was the principal postmortem finding in the foal. No specific etiology was confirmed in either case. Notably, Escherichia coli 0103:H2 was isolated from the mare's uterus and the gastrointestinal tracts of both animals. To the authors' knowledge, this is the first report in which an organism implicated as a cause of hemolytic-uremic syndrome was isolated from an animal with clinical signs and postmortem findings consistent with the disease.

The protease-resistant infectious prion protein, PrPres, that causes transmissible spongiform encephalopathies, is remarkably resistant to conventional physical and chemical sterilization methods, including heat. It was hypothesized that thermal-dependent PrPres degradation has been underestimated, and the effect of prolonged incubation at 37 degrees C, 55 degrees C, and 80 degrees C on PrPres detection was examined using brain homogenates from chronic wasting disease-affected elk and mule deer (PrPCWD). Immunoblotting demonstrated progressive loss of PrPCWD immunoreactivity with time in all incubated samples as temperature increased, and PrPCWD was virtually undetectable after 90 days of incubation at 55 degrees C and 80 degrees C. These results indicate that decontamination methods and tissue disposal systems maintaining elevated temperatures for long periods of time could interfere with immunodetection, and the reliability of assays for PrPres detection could be compromised when applied to tissues exposed to heat with time. Although these results may suggest that such prolonged heat treatment could destroy prions, the observed loss of immunoreactivity does not necessarily correlate with a concurrent loss of infectivity. Bioassay is needed to determine if samples that have been incubated under these conditions retain infectivity.

Tree squirrels (Sciurus spp.) have exhibited high seroprevalence rates, suggesting that they are commonly exposed to West Nile virus (WNV). Many characteristics of WNV infections in tree squirrels, such as the durations and levels of viremia, remain unknown. To better understand WNV infections in fox squirrels (S. niger), we subcutaneously inoculated fourteen fox squirrels with WNV. Peak viremias ranged from 10(4.00) plaque-forming units (PFU)/mL of serum on day 2 post-infection (DPI) to 10(4.98) PFU/mL on 3 DPI, although viremias varied between individuals. Oral secretions of some fox squirrels were positive for WNV viral RNA, occasionally to moderate levels (10(3.2) PFU equivalent/swab). WNV PFU equivalents in organs were low or undetectable on 12 DPI; gross and histologic lesions were rare. The viremia profiles of fox squirrels indicate that they could serve as amplifying hosts in nature. In addition, viral RNA in the oral cavity and feces indicate that this species could contribute to alternative WNV transmission in suburban communities.

Eastern Screech Owls (EASOs) were experimentally infected with the pathogenic New York 1999 strain of West Nile virus (WNV) by subcutaneous injection or per os. Two of nine subcutaneously inoculated birds died or were euthanatized on 8 or 9 days postinfection (DPI) after <24 hr of lethargy and recumbency. All subcutaneously inoculated birds developed levels of viremia that are likely infectious to mosquitoes, with peak viremia levels ranging from 10(5.0) to 10(9.6) plaque-forming units/ml. Despite the viremia, the remaining seven birds did not display signs of illness. All birds alive beyond 5 DPI seroconverted, although the morbid birds demonstrated significantly lower antibody titers than the clinically normal birds. Cagemates of infected birds did not become infected. One of five orally exposed EASOs became viremic and seroconverted, whereas WNV infection in the remaining four birds was not evident. All infected birds shed virus via the oral and cloacal route. Early during infection, WNV targeted skin, spleen, esophagus, and skeletal muscle. The two morbid owls had myocardial and skeletal muscle necrosis and mild encephalitis and nephritis, whereas some of the clinically healthy birds that were sacrificed on 14 DPI had myocardial arteritis and renal phlebitis. WNV is a significant pathogen of EASOs, causing pathologic lesions with varying clinical outcomes.

Four dead canine pups (5-12 days old) from 3 litters in Douglas County of north central Colorado were submitted to the Colorado State University Diagnostic Laboratory for necropsy. Pups were originally presented to the referring clinics for respiratory tract illness, with or without diarrhea. At necropsy, the lungs from all pups had similar lesions, including random foci of hemorrhage and failure to collapse on opening of the thoracic cavity. The lungs were histologically characterized by subacute interstitial pneumonia, with alveolar septa expanded by a histiocyte-rich infiltrate with a few lymphocytes and neutrophils. The alveolar spaces were filled with moderate amounts of proteinaceous fluid, foamy macrophages, and a few neutrophils. Lungs from 3 of the 4 pups were test positive for canine distemper virus (CDV) by use of reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Immunohistochemically stained lungs, including those from the pup that were CDV negative, by use of RT-PCR analysis, were test positive for CDV antigen in bronchial and bronchiolar epithelial cells and in a few alveolar macrophages. Central nervous system lesions were not observed in any of the 4 pups. These cases represent an unusual presentation of canine distemper in neonatal pups marked by respiratory tract lesions without central nervous system involvement. Canine distemper should be considered in the differential diagnosis of neonatal canine respiratory tract illness.

A geographically targeted survey of potentially high-risk, adult cattle in chronic wasting disease (CWD)-endemic areas in Colorado was initiated to assess the possibility of the spread of CWD from deer to cattle under natural conditions. Surveyed cattle were sympatric with free-roaming deer in geographically defined areas where CWD occurs and where CWD prevalence has been estimated. To qualify for inclusion in the survey, cattle had to be at least 4 years old and had to have spent a minimum of 4 years in surveyed areas. Brains from culled cattle were examined microscopically and immunohistochemically for tissue alterations indicative of a transmissible spongiform encephalopathy (TSE). Two hundred sixty-two brains were suitable for evaluation and were found to lack changes indicative of a TSE infection. Prion deposition was not demonstrable using a method involving formic acid and proteinase-K treatment before application of monoclonal antibody to bovine prion protein (F99/97.6.1). Some incidental neuropathologic changes unrelated to those of TSEs were detected. Findings from this study suggest that large-scale spread of CWD from deer to cattle under natural range conditions in CWD-endemic areas of northeast Colorado is unlikely.

Objective: To analyze the sulfur content of water and forage samples from a geographically diverse sample of beef cow-calf operations in the United States and to estimate frequency and distribution of premises where forage and water resources could result in consumption of hazardous amounts of sulfur by cattle., Design: Cross-sectional study., Sample Population: 709 forage samples from 678 beef cow-calf operations and individual water samples from 498 operations in 23 states., Procedure: Sulfur content of forage samples and sulfate concentration of water samples were measured. Total sulfur intake was estimated for pairs of forage and water samples., Results: Total sulfur intake was estimated for 454 pairs of forage and water samples. In general, highest forage sulfur contents did not coincide with highest water sulfate concentrations. Overall, 52 of the 454 (11.5%) sample pairs were estimated to yield total sulfur intake (as a percentage of dry matter) > or = 0.4%, assuming water intake during conditions of high ambient temperature. Most of these premises were in north-central (n = 19) or western (19) states., Conclusions and Clinical Relevance: Results suggest that on numerous beef cow-calf operations throughout the United States, consumption of forage and water could result in excessively high sulfur intake. All water sources and dietary components should be evaluated when assessing total sulfur intake. Knowledge of total sulfur intake may be useful in reducing the risk of sulfur-associated health and performance problems in beef cattle.

Globoid cell leukodystrophy (GLD; Krabbe disease), is a rare heritable metabolic disorder in humans, dogs, mutant twitcher mice, and rhesus monkeys that is caused by a deficiency in the lysosomal enzyme galactocerebrosidase (GALC). GALC deficiency results in the accumulation of psychosine, which is toxic to oligodendrocytes and Schwann cells of the central and peripheral nervous systems. Clinical signs include hypotonia, mental regression, and death by 2 years of age in most human patients. Here we describe a domestic longhaired kitten with rapidly progressive neurologic disease and brain and spinal cord lesions characteristic of GLD. Pathologic hallmarks of the disease reflect the loss of oligodendrocytes and include myelin loss, gliosis, and the perivascular accumulation of large mononuclear cells with fine cytoplasmic vacuoles (globoid cells) in the peripheral and central nervous systems. Globoid cells were CD68 and ferritin positive, confirming their monocytic origin, and cytoplasmic contents were nonmetachromatic and periodic acid-Schiff positive.

Two hundred forty single-source, cross-bred steers (304 kg) were used to evaluate the effects of various water sulfate concentrations on performance, water intake, and carcass characteristics of feedlot steers. Cattle were stratified by weight and assigned within weight blocks to five water treatments. Averaged over time, actual water sulfate concentrations (+/- SEM) were 136.1 (+/- 6.3), 291.2 (+/- 15.3), 582.6 (+/- 16.9), 1,219.2 (+/- 23.7), and 2,360.4 (+/- 68.2) mg/L, respectively. Weather-related data were recorded. Increasing water sulfate concentration resulted in linear decreases in ADG (P < 0.01) and gain:feed ratio (P < 0.01) and a quadratic effect on water intake (P = 0.02) and tended to quadratically increase then decrease DMI (P = 0.13). Sulfate x period interactions were evident for DMI (P = 0.01), ADG (P < 0.01), and feed efficiency (P < 0.01). Time had quadratic effects on DMI, water intake, ADG, and feed efficiency (P < 0.01 for all models). Increasing water sulfate concentration resulted in linear decreases in final weight, hot carcass weight, and dressing percentage, a linear increase in longissimus muscle area, and a quadratic effect on fat thickness over the 12th rib and predicted yield grade (P < 0.05 for all dependent variables). Mean daily temperature explained 25.7% of the observed variation in water intake. Other factors that explained a significant (P < 0.01) amount of variation in water intake were BW, DMI, water sulfate concentration, barometric pressure, wind speed, and humidity. High water sulfate concentrations had a significant and deleterious effect on performance and carcass characteristics of feedlot steers. Increasing the sulfate concentration in water may have resulted in a functional water restriction early in the trial when ambient temperatures were greatest. However, toward the latter stages of the trial, cattle supplied higher-sulfate water had higher ADG and FE. These improvements later in the trial may represent compensatory gain associated with decreased ambient temperature and water requirements. Averaged over time, a water sulfate concentration of greater than 583 mg/L, equivalent to 0.22% of the diet, decreased feedlot performance.

Objective: To evaluate viral and bacterial respiratory pathogens and Mycoplasma spp isolated from lung tissues of cattle with acute interstitial pneumonia (AIP) and cattle that had died as a result of other causes., Sample Population: 186 samples of lung tissues collected from cattle housed in 14 feedlots in the western United States., Procedure: Lung tissues were collected during routine postmortem examination and submitted for histologic, microbiologic, and toxicologic examinations. Histologic diagnoses were categorized for AIP, bronchopneumonia (BP), control samples (no evidence of disease), and other disorders., Results: Cattle affected with AIP had been in feedlots for a mean of 1272 days before death, which was longer than cattle with BP and control cattle. Detection of a viral respiratory pathogen (eg, bovine respiratory syncytial virus [BRSV], bovine viral diarrhea virus, bovine herpesvirus 1, or parainfluenza virus 3) was not associated with histologic category of lung tissues. Bovine respiratory syncytial virus was detected in 8.3% of AIP samples and 24.0% of control samples. Histologic category was associated with isolation of an aerobic bacterial agent and Mycoplasma spp. Cattle with BP were at greatest risk for isolation of an aerobic bacterial agent and Mycoplasma spp., Conclusions and Clinical Relevance: Analysis of these results suggests that AIP in feedlot cattle is not a consequence of infection with BRSV. The increased, risk of isolation of an aerobic bacterial agent from cattle with AIP, compared with control cattle, may indicate a causal role or an opportunistic infection that follows development of AIP.

Objective: To compare concentrations of 3-methyleneindolenine (3MEIN) in lung tissues obtained from feedlot cattle that died as a result of acute interstitial pneumonia (AIP) and cattle that died as a result of other causes and to compare blood concentrations of 3MEIN in healthy feedlot cattle and feedlot cattle with AIP., Study Population: Blood samples and lung tissues collected from 186 cattle housed in 14 feedlots in the western United States., Procedure: Samples of lung tissues were collected during routine postmortem examination and submitted for histologic, microbiologic, and toxicologic examination. Blood samples were collected from cattle with clinical manifestations of AIP and healthy penmates. Histologic diagnoses were categorized as AIP, bronchopneumonia (BP), control samples, and other disorders. Concentrations of 3MEIN were determined in lung tissues and blood samples, using an ELISA., Results: Concentrations of 3MEIN in lung tissues were significantly greater in AIP and BP samples, compared with control samples. Absorbance per microgram of protein did not differ between BP and AIP samples. Blood concentrations of 3MEIN were significantly greater in cattle with AIP, compared with healthy cattle or cattle with BP. Odds of an animal with AIP being a heifer was 3.1 times greater than the odds of that animal being a steer., Conclusions and Clinical Relevance: Increased pulmonary production of 3MEIN may be an important etiologic factor in feedlot-associated AIP.

Objective: To determine historical, physical examination, clinicopathologic, and postmortem findings in horses with putative uremic encephalopathy. Design-Retrospective study. Animals-5 horses with renal failure and neurologic disease not attributable to abnormalities in any other organ system., Procedure: Medical records from 1978 to 1998 were examined for horses with renal disease and neurologic signs not attributable to primary neurologic, hepatic, or other diseases. Signalment, history, physical examination findings, clinicopathologic data, renal ultrasonographic findings, and postmortem data were reviewed., Results: Of 332 horses with renal disease, 5 met selection criteria. Historical findings, physical examination findings, clinicopathologic data, ultrasonographic data, and postmortem findings were consistent with chronic renal failure. Swollen astrocytes were detected in all 4 horses examined at necropsy., Conclusions and Clinical Relevance: A single criterion was not determined to be pathognomonic for uremic encephalopathy in horses. Uremic encephalopathy should be considered as a differential diagnosis in horses with evidence of chronic renal failure and encephalopathic neurologic sign not attributable to other causes. Astrocyte swelling, which was common to all 4 horses examined at necropsy, may serve as a microscopic indicator of uremic encephalopathy in horses.

Sulfur-related polioencephalomalacia is frequently associated with a high total sulfur intake by ruminants. The onset of clinical signs coincides with excessive ruminal sulfide production. Measurement of ruminal gas cap hydrogen sulfide makes it possible to identify cattle with potentially hazardous total sulfur intake. Evaluation of all potential sulfur sources is necessary to estimate total dietary sulfur concentration, which can lead to prevention strategies.

The application of pneumatic-powered air injection stunners (PPAISs), pneumatic-powered stunners (PPSs), and cartridge-fired stunners (CFSs) in commercial beef slaughter plants was evaluated to determine the extent of dissemination of central nervous system tissue. Fifteen beef slaughter plants in the western and central United States were visited to observe stunning methods and the condition of the hearts at postmortem inspection. As inspectors performed the normal opening of the hearts, the research observer evaluated the contents of the heart for the presence of clots and/or visible tissue segments in the right ventricle. In eight plants where PPAISs were used, 33% of hearts examined (n = 1,050) contained large clots in the right ventricles. In the four plants where CFSs were used, 1% of the hearts (n = 480) contained detectable clots. In three plants where the newly modified PPSs were used, 12% of the hearts (n = 450) contained detectable clots. Large segments of spinal cord were detected, collected, photographed, and confirmed histologically from two hearts in a plant that used a PPAIS. Most of the material was found in a single right ventricle and was composed of 10 to 13 cm segments of spinal cord.

The current methods to detect central nervous system (CNS) tissue in blood, lungs, or meat are cumbersome, time consuming, and costly. The objective of this study was to use glial fibrillary acidic protein (GFAP), which is restricted to the CNS, in an enzyme-linked immunosorbent assay (ELISA) for the detection of CNS tissue in blood and muscle from beef cattle. Bovine brain, cerebral cortex, spinal cord, sciatic nerve, diaphragm, blood clots, and other skeletal muscle were obtained from three animals at slaughter. The limit for detection of GFAP was approximately 1.0 ng and the standard curve was linear up to 40 ng. Tissue samples gave responses parallel to the GFAP standard, suggesting that standard and unknown samples were immunoreactively identical. No GFAP was detected in skeletal muscle (ground beef, shoulder clod, and diaphragm) and blood clots. Trace amounts (13.5 to 51 ng/mg) were present in sciatic nerve. In contrast, high levels of GFAP (55 to 220 microg/ mg) were present in spinal cord, cerebral cortex (17 microg/mg), and whole brain (9 to 55 microg/mg). In a storage study using two animals in two separate studies, immunoreactive GFAP was detectable for up to 8 days at 4 degrees C in all tissues containing neural elements. Thus, mixtures of muscle with spinal cord or brain retained almost 80% of their immunoreactivity after 8 days at 4 degrees C, while brain and spinal cord alone retained approximately 50% and 25%, respectively, of their initial activities. In a repeat experiment, 80 to 100% of the initial activity was retained in these tissues after 8 days at 4 degrees C. The results of the current study demonstrate that the GFAP ELISA provides a valid and repeatable method to detect CNS tissue contamination in meat.

During a 2-week period, 16 of 150 recently weaned calves developed signs of polioencephalomalacia (PEM). One calf was examined and treated at our veterinary teaching hospital and a necropsy was performed on a calf that died. During the peak of the outbreak, clinicians visited the ranch. Ruminal hydrogen sulfide (H2S) and blood thiamine concentrations were measured in 10 clinically normal penmates of PEM-affected calves. Ruminal H2S concentrations were high (> 0.695 mg/L [> 500 ppm]) in all cattle (mean, 12.19 mg/L [8,770 ppm]). All blood thiamine values were within the reference range. Within 12 hours after measurement of blood thiamine concentrations, 2 of the calves from which samples were obtained developed clinical signs of PEM. Dietary analysis revealed an estimated sulfur intake of 0.9% per calf on a dry-matter basis. Hay contributed most of this sulfur. In the investigation reported here, an outbreak of PEM was associated with high ruminal H2S concentrations and excess sulfur intake without evidence of thiamine deficiency.

Four cattle had chronic diarrhea and had lost weight but were not anorectic or dehydrated. A diagnosis of eosinophillic enteritis was made on the basis of a combination of clinical and histopathologic findings and exclusion of other diseases. Eosinophilia and hypoalbuminemia were not detected in CBC analyses. Gross and histologic examination of the small intestine revealed edema, diffuse eosinophilic inflammation (> 20 eosinophils/HPF [400 x]), and regional lymphadenopathy. A causative agent was not identified in any of the cattle. Treatment consisting of a 1-month course of systemically administered corticosteroids was attempted in 2 cattle and was apparently successful in both. Diagnostic criteria for eosinophilic enteritis have not been established for cattle and, therefore, the diagnosis was subjective. This disease resembled paratuberculosis (Johne's disease) in clinical appearance but was distinguished on the basis of a lack of a contagious etiologic agent and differences in histologic appearance.

Polioencephalomalacia (PEM) is a neuropathologic condition of ruminants that can be induced by a variety of neural metabolic disruptions. These include altered thiamine status, water deprivation-sodium ion toxicosis, lead poisoning, and high sulfur intake. Investigations of sulfur-related PEM have demonstrated that the onset of the clinical signs coincides with excessive ruminal sulfide production. A number of ruminal factors could modulate the production and absorption of ruminal sulfide. The development of a convenient method to estimate ruminal gas cap H2S has made it possible to identify cattle with high levels of ruminal H2S and evaluate their risk of developing PEM.

Objectives: To measure concentrations of thiamine in blood and sulfide in ruminal fluid in cattle with polioencephalomalacia (PEM) and to evaluate temporal associations between PEM and risk factors., Design: Epidemiologic analysis., Sample Population: 14 steers with acute signs of PEM, 26 clinically normal steers and records of all cattle in a feedlot for the past 6 years., Procedures: Concentrations of thiamine in blood and sulfide in ruminal fluid were measured. Values were compared between healthy steers that had been in the feedlot for 3 weeks or 2 months. Records were used to estimate the incidence of PEM and the time when cattle were at greatest risk of developing PEM., Results: Thiamine concentrations in steers with PEM were within reference ranges. Healthy steers had significantly greater sulfide concentrations 3 weeks after entering the feedlot, when the incidence of PEM was greatest, than 2 months after entering the feedlot, when risk of developing PEM was low. Thiamine concentrations were within reference ranges at these times. Annually recurrent outbreaks of PEM during the summer began after initiating use of a water well containing a high content of sulfate., Clinical Implications: Excessive ruminal sulfide production is an important factor in the pathogenesis of PEM, without concurrent thiamine deficiency. Most cases of PEM developed between 15 and 30 days after introduction to a high-sulfur diet. When water is an important source of dietary sulfur, risk of PEM may increase during hot weather.

Two groups of 3 120-160-kg Holstein steers were fed a diet high in carbohydrate and low in long fiber and either with or without added sodium sulfate. Prior to and during the course of feeding the experimental diet, the concentrations of rumen hydrogen sulfide gas and rumen fluid sulfide were determined by a simple sulfide detector tube method and by sulfide-selective electrode, respectively. Other measurements included rumen fluid pH, blood creatine kinase, and blood sulfhemoglobin. Two of the 3 steers fed the high-sulfate diet developed signs and lesions of polioencephalomalacia. Clinical signs included episodic ataxia and blunted or absent menace reaction. Increased ruminal H2S gas concentrations occurred in all 3 steers consuming the diet with added sulfate. The onset of clinical signs coincided with the onset of elevated H2S concentrations. These increases were 40-60 times the values measured in the steers consuming the diet without added sulfate. In contrast, increases in rumen fluid sulfide concentrations usually rose to 4 times that of control steers. The steers fed an identical diet but without added sulfate exhibited no signs or lesions of polioencephalomalacia and no elevations of sulfide in rumen gas or fluid. All steers had a modest decrease in rumen fluid pH associated with the transition to the concentrate diet. No significant changes were observed in any of the blood measurements of any of the steers. An additional pair of steers was fed the experimental diet with or without added sulfate to compare the ruminal H2S gas concentrations estimated by H2S detector tubes with those estimated by a different method of analysis utilizing charcoal trapping of H2S, conversion to sulfate, and measurement of the sulfate. Both methods yielded comparable estimates of H2S concentration. Overall, these data indicate that changes in rumen gas cap H2S concentrations are larger than changes in rumen fluid sulfide concentration and the estimation of rumen gas cap H2S concentration may be a practical approach to detecting pathologic increases in ruminal H2S gas. This simple, rapid, minimally invasive method should be useful for estimating the H2S content of ruminal gas under field conditions.

Holstein steers were fed carbohydrate-rich, short-fiber basal diets with and without added sodium sulfate. Steers fed the high-sulfate diet developed the CNS disorder polioencephalomalacia (PEM). The onset of signs of PEM was associated with increased sulfide concentration in the rumen fluid. Over the course of the disease, anaerobic rumen bacteria were enumerated in roll tubes by use of the Hungate method Lo determine the effect of dietary sulfate on sulfate-reducing bacterial numbers. Media used included a general type for total counts and sulfate containing media with and without cysteine to assess sulfate-reducing bacteria. Changes in total and sulfate reducing bacterial numbers attributable to dietary sulfate content were not observed. The capacity to generate hydrogen sulfide from sulfate in fresh rumen fluid in vitro was substantially increased only after steers had been fed the high sulfate diet for 10 to 12 days, which coincided with the onset of signs of PEM. The low capacity for hydrogen sulfide production of rumen fluid taken at earlier times in the feeding period suggests that rumen microorganisms must adapt to higher dietary sulfate content before they are capable of generating potentially toxic concentrations of sulfide.

To study their role in sulfate reduction, anaerobic bacteria were cultured from rumen fluid samples of cattle fed high-carbohydrate, short-fiber diets with and without added sulfate. The steers fed the diet with added sulfate developed polioencephalomalacia. Microbiological methods included colony type profiles, molybdate sensitivity, presence of desulfoviridin, sulfate reduction rates of pure and mixed cultures, and incubation time effects on sulfate reduction. Colony-type profiles indicated decreased diversity, but no relative change in numbers of sulfate-reducing bacteria in rumen fluid from cattle fed diets with and without added sulfate. Thirteen bacteria] isolates were selected for further study on the basis of colony type, sulfate-reducing activity, and growth in lactate, sulfate, and yeast extract media. Seven of the isolates had Desulfovibrio-like characteristics (ie, they were gram-negative, motile rods that reduced sulfate, were inhibited by molybdate, and contained the pigment desulfoviridin). The remaining 6 isolates were gram-negative, nonmotile rods. Four of these released sulfide from cysteine, and 2 generated only limited amounts of sulfide from sulfate or cysteine. The 7 sulfate reducing isolates generated sulfide in rumen fluid broth medium at greater rates than those observed in fresh rumen fluid. Sulfate reduction Could be sustained in cultures for prolonged incubation times if the gas phase containing hydrogen sulfide was replaced at frequent intervals. Variations in the amount of sulfate reduced by the pure cultures were most pronounced at short incubation times. Sulfate reduction was not inhibited in mixed cultures of sulfate-reducing and nonsulfate-reducing bacteria.

The biological and forensic use of ion-interaction reversed-phase high-performance liquid chromatography for the determination of hydrogen sulfide-derived methylene blue is evaluated by measuring the sulfide content in tissues from sulfide-treated mice. Various preparative conditions were examined. The determinations of background levels of sulfide from brain, liver and kidney were compared to sulfide levels from mice exposed to 60 micrograms g-1 sodium hydrosulfide. At the time of death, significant increases above background sulfide levels were measured for all three biological tissues. To evaluate its forensic potential, we used this sulfide detection methodology to evaluate comparatively the sulfide levels from fresh and frozen samples of brain, liver and kidney. The stability of sulfide levels obtained from frozen brain makes this tissue the most reliable tissue for forensic evaluation. Samples of brain, liver and kidney obtained within 24 h of death by sulfide intoxication had demonstrable elevations in sulfide concentration.

There is a paucity of information regarding natural Aleutian disease, caused by a parvovirus in ferrets. With the increasing popularity of ferrets as household pets and laboratory animals, and with the advent of a USDA-approved rabies vaccine, the occurrence and the etiopathogenesis of naturally acquired diseases in ferrets needs to be documented. We present the clinical and laboratory findings associated with Aleutian disease in 2 domestic ferrets, one with the chronic wasting form of the disease and one with the central nervous system form.

Polioencephalomalacia (PEM) was induced in four of 10 lambs by the administration of a sulphide solution into the oesophagus at 20 min intervals for a period of 40 to 120 min. Signs of neurological dysfunction occurred in all 10 lambs during that time and included stupor, visual impairment and seizures. Gross autofluorescent and microscopic lesions in cerebrocortical grey matter were present as soon as 20 h after sulphide administration and were indistinguishable from lesions in naturally occurring disease. These findings, when considered together with an earlier study that revealed an association between high ruminal concentrations of sulphide and PEM, indicate that this disease can result from sulphide toxicosis, independent of the metabolic status of thiamine.

The histopathologic response of the canine spinal cord to fractionated doses of radiation was investigated. Forty-two dogs received 0, 44, 52, 60, or 68 Gy in 4 Gy fractions to the thoracic spinal cord. Dogs were evaluated for neurologic signs and were observed for 1 or 2 years after irradiation. Six major lesion types were observed; five in the irradiated spinal cord and one in irradiated dorsal root ganglia. The three most severe spinal cord lesions were white matter necrosis, massive hemorrhage, and segmental parenchymal atrophy which had an ED50 of 56.9 Gy (51.3-63.3 Gy 95% CI) in 4 Gy fractions. These lesions were consistently associated with abnormal neurologic signs. Radiation damage to the vasculature was the most likely cause of these three lesions. The two less severe spinal cord lesions were focal fiber loss, which had an ED50 of 49.5 Gy (44.8-53.6 Gy 95% CI) in 4 gy fractions and scattered white matter vacuolation that occurred at all doses. These less severe lesions were not consistently associated with neurologic signs and indicated the presence of residual damage that may occur after lower doses of radiation. Radiation damage to glial cells, axons, and/or vasculature were possible causes of these lesions. In the irradiated dorsal root ganglia, affected sensory neurons contained large intracytoplasmic vacuoles, and there was loss of neurons and satellite cells. Such alterations could affect sensory function. The dog is a good model for spinal cord irradiation studies as tolerance doses for lesions causing clinical signs are close to the estimated tolerance doses for humans, and studies involving volume and long-term observation can be done.

Nine 115- to 180-kg, hay-adapted, Holstein steers were fed an experimental diet with added sodium sulfate that induces polioencephalomalacia (PEM). Five calves developed the disease. Thiamine concentrations in blood, CSF, brain, and liver were not indicative of thiamine deficiency. The odor of hydrogen sulfide in eructated rumen gas was associated with the onset of PEM. Sulfide concentrations in rumen fluid were measured 1 or 2 times a week by 2 techniques. Sulfide concentrations progressively increased in all 9 calves after the feeding of the PEM-inducing diet commenced. The highest concentrations coincided with the onset of clinical signs of PEM and were significantly higher in the calves that developed PEM than in those that did not. This suggests that PEM can result from sulfide toxicosis following excess production of sulfide in the rumen.

Allogeneic bone marrow transplantation (BMT) was successfully performed in four Chediak-Higashi (CHS) syndrome affected cats. Preparatory regimens included selective intestinal flora decontamination, fractionated total body irradiation for myeloablation, and prophylactic treatment for graft-versus-host disease with cyclosporin A. Neutrophil chemotaxis under-agarose and whole-blood platelet aggregation/secretion were characterized prior to BMT and after engraftment of donor-origin marrow cells. Liver and kidney biopsies were obtained and evaluated by light and electron microscopy before, and at 6 months post-BMT to determine what effect BMT might have on abnormal lysosome fusion in hepatocytes and renal tubule cells. The platelet storage pool defect was resolved by day 40 post-BMT. In vitro neutrophil migration in all cats appeared to improve with time after BMT and complete restoration was evident by day 175 post-BMT. No apparent differences were evident in either the liver or the kidney at 6 months post-BMT. One cat developed seizures and one developed posterior paresis 5 months post-BMT; neurologic impairment ultimately resulted in death of two cats at 6 and 8 months post-BMT, respectively. Neurologic lesions in both cats were characterized by non-suppurative encephalitis. Allogeneic BMT successfully corrected the neutrophil migration defect and platelet storage pool deficiency but had no effect on lysosome distribution in liver and kidney cells of CHS cats.

The effect of glutathione (GSH) depletion by buthionine sulphoximine (BSO) on the nephrotoxicity and GSH-enhancing effect of the naturally occurring, crucifer-derived nitrile 1-cyano-3.4-epithiobutane (CEB), was investigated. Male Fischer 344 rats were administered 50 or 125 mg CEB/kg body weight by gavage with or without prior ip treatment with 550 mg/kg body weight L-BSO. One group of control animals was treated with water only by gavage, while another group was pretreated with BSO and then given water by gavage. Liver and kidney samples were taken 48 hr after CEB treatment for GSH determinations and histological examination. The high-dose CEB without BSO resulted in increased GSH in liver and kidney, marked karyomegaly in the pars recta of renal proximal tubules and tubular epithelial necrosis, which was limited to a few renal tubules. The low-dose CEB alone resulted in increased hepatic GSH and mild karyomegaly. Pretreatment with BSO abrogated the tubular necrosis and karyomegaly induced by either CEB dose. BSO pretreatment inhibited low-dose CEB-induced GSH enhancement in the liver. The combined BSO and high-dose CEB treatment still resulted in increased hepatic GSH, although the increase was less than that observed with high-dose CEB alone. In the kidney, BSO pretreatment abrogated the high-dose CEB-induced increase in GSH, but GSH content was not significantly different from that with high- or low-dose CEB alone. These results provide evidence that CEB conjugation may be a bioactivation reaction with the conjugate involved in nephrotoxicity. The conjugate may also be involved in increasing renal and hepatic GSH.

Polioencephalomalacia (PEM) was induced in calves by feeding a semipurified, low-roughage diet of variable copper and molybdenum composition. Two formulations resulting in Cu-insufficient and Cu-sufficient forms of the diet were fed (n = 10 and 4 calves, respectively); both diets induced PEM. Clinical signs of disease developed as early as 15 days after transition to the experimental diets and included impaired vision, decreased response to external stimuli, and abnormal gait. Grossly evident cerebrocortical lesions consisted of laminar areas of cavitation and/or autofluorescence seen under UV illumination. Hepatic Cu concentration was decreased in calves fed the Cu-insufficient diet, but not below normal range. During the course of feeding either diet, rumen pH decreased, rumen volatile fatty acid concentrations increased, rumen and blood lactic acid concentrations increased, and rumen and plasma thiamine concentrations increased. The thiamine pyrophosphate effect on erythrocyte transketolase activity was unaltered in calves of either diet group. This nutritionally induced form of PEM does not appear to be related to Cu deficiency or reduction in plasma or rumen thiamine concentration.

The effects of a single subcutaneous (s.c.) injection of the nitroaliphatic toxicants 3-nitropropanol (NPOH) and 3-nitropropionic acid (NPA) dissolved in physiological saline solution were studied in mice and rats, respectively. Clinical signs observed in both NPOH-treated mice and NPA-treated rats included depression, abnormal motor activity, and recumbency. Succinate dehydrogenase (SDH) activity, demonstrated histochemically in frozen brain sections, was markedly reduced in intoxicated mice and rats. The SDH activity of mitochondrial preparations from brains of intoxicated mice and rats was diminished to 18-24% of control values, although the activity of another mitochondrial flavoprotein enzyme, alpha-glycerophosphate dehydrogenase (alpha-GPDH), was not altered.

Diflubenzuron, one of a new class of pesticides believed to act via inhibition of chitin synthesis in the developing insect cuticle, was tested for possible mutagenic activity using the micronucleus test in mice, the L5178Y mouse lymphoma forward mutation test at the thymidine kinase locus, and the Ames Salmonella/microsome reverse mutation test. No mutagenic effect was found.

Micronuclei induced in bone marrow erythroblasts by clastogenic chemicals are easily detected in peripheral blood. In mice treated with nitrogen mustard, 7,12 dimethylbenz(a)anthracene, or cyclophosphamide, the peak incidence of micronucleated polychromatic erythrocytes in peripheral blood was at least as great as the maximum incidence in bone marrow. In each case the peak incidence in blood occurred on the day following the peak incidence observed in bone marrow. Thus, for general genetic screening purposes, monitoring micronuclei in peripheral blood rather than in bone marrow smears provides at least equal sensitivity, offers greater simplicity in sample preparation and scoring, permits multiple sampling of treated animals, and may also facilitate automated scoring and human cytogenetic monitoring.

Five haloalkanes--CBrCl3, CCl4, CHCl3, and 1,1,1-and 1,1,2-trichloroethane (TCE)--were ranked for their relative hepatotoxicity in an in vitro system of isolated hepatocyte suspensions and in vivo by po administration of the test chemical to fasted rats of the same strain and sex as used for the hepatocytes. Cytotoxic parameters used for ranking in the in vitro system were GOT and LDH release, and the results were expressed in terms of EC50 values (the dissolved haloalkane concentration required to release 50% of the cell content of each enzyme after 2 hr of exposure) for rank determination. Cytotoxic parameters measured in vivo were SGOT and SGPT, and the ranking was based on ED50 values (the haloalkane dose that produced an above normal serum transaminase level in 50% of the test animals). With these parameters, the potency rankings in each system were the same except that of 1,1,1-TCE, which was more cytotoxic in the in vitro system than would have been expected from the animal experiments. Purification of the 1,1,1-TCE to remove stabilizers, use of phenobarbital-induced hepatocytes or hepatocytes from starved rats, and administration of the haloalkanes ip instead of po failed to improve the correlation. The discrepancy could be resolved, however, by factoring air: medium partition coefficient data into the EC50 values to take into account differences in the volatility and aqueous and lipid solubility of the chemicals, and hence their retention in vivo. These observations encourage the belief that isolated hepatocyte systems have value for ranking structurally related chemicals as to their cytotoxic potential, even though their mechanisms of action may differ.