bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunocytochemical localization of adrenocorticotropic hormone-immunoreactive cells of the pars intermedia in Thoroughbreds
Authors: Okada Toshiya , Shimomuro Takeaki , Oikawa Masaaki , Nambo Yasuo , Kiso Yasuo , Morikawa Yoshio , Liptrap Robert M. , Yamashiro Shigeto , Little Peter B. , Sasaki Fumihiko 
Published: January 2024

Abstract

Objective
To analyze and characterize adenoma and hyperplasia of the pars intermedia (PI) of Thoroughbred mares.

Animals
165 Thoroughbred mares, without clinical signs of hyperadrenocorticism that had been euthanatized or had died, of causes such as sudden death, colic, pneumonia, or trauma, and were necropsied. Five of those horses, 17 to 25 years old, had a large pituitary gland at necropsy. Eight mares, 5 to 15 years old with normal-size pituitary gland, were selected at random for comparison.

Procedure
A morphologic comparison of the pituitary gland between horses with and without tumors of the PI was conducted by use of immunocytochemistry and morphometry.

Results
In horses with normal pituitary gland, the PI was supplied by a vast capillary or sinusoidal plexus, which connected that in the pars distalis (PD) with that in the pars nervosa (PN). Cells of the PI stained slightly with ACTH antiserum, but some cells in the border region, which is contiguous to the PD, were strongly ACTH immunoreactive. At necrospy, horses with an enlarged pituitary gland also had adenoma of the pituitary gland involving the PI. Cells of the border region were hypertrophied and stained strongly with ACTH antiserum. The area and number of individual tumor cells of the border region of the PI of horses with adenoma were significantly increased, compared with those in horses with normal pituitary gland.

Conclusions
Cells of the PI-PD border region may secrete substantial quantities of ACTH, owing to stimulation by corticotropin-releasing factor. Adenoma and hyperplasia of the PI in Thoroughbred mares may be associated with hyperadrenocorticism. (Am J Vet Res 1997;58:920–924)
Field trial to evaluate the immunogenicity of pseudorabies virus vaccines with deletions for glycoproteins G and E
Authors: Firkins Lawrence D. , Weigel Ronald M. , Biehl LeRoy G. , Hahn Edwin C. 
Published: January 2024

Abstract

Objective
To evaluate, under field conditions, the immunogenicity of 2 pseudorabies virus (PRV) vaccines (each with deletion of the gene for glycoprotein G [gG], and 1 with an additional deletion for glycoprotein E [gE]), particularly in the presence of maternal antibodies, and to investigate the effect of vaccination schedules in overcoming maternal antibody interference with vaccination.

Sample Population
Two cohorts of 105 growing pigs each on a PRV-seronegative commercial swine farm where breeding stock had been vaccinated with a PRV vaccine containing deletions of genes for gG and gE.

Procedure
Within each cohort, pigs were randomly assigned to 1 of 7 treatment groups. For each vaccine, vaccination was done at 8, 12, or 8 and 12 weeks of age. One group remained unvaccinated. Blood and nasal swab specimens were obtained at 8, 10, 12, 14, and 16 weeks of age, and the immune response was measured, by use of an ELISA.

Results
In cohort 1, where prevalence of maternal antibodies at 8 weeks of age was lower, an immune response lasting until 16 weeks of age was induced in most pigs by either vaccine. In cohort 2, where prevalence of maternal antibodies at 8 weeks of age was higher, the gG-gE- vaccine elicited a lower immune response in the presence of maternal antibodies than did the gG- vaccine after single vaccination at 8 weeks of age. This maternal antibody interference with the response to vaccination was evident in serum and nasal mucosal antibodies.

Conclusions
The gE deletion decreases the immunogenicity of PRV vaccine in the presence of maternal antibodies. Although evidence of maternal antibody interference for the gG- vaccine existed, its immunogencity was diminished less in the presence of maternal antibodies than that of the gG-gE- vaccine. (Am J Vet Res 1997;58:976–984)
Dietary modulation of methotrexate-induced enteritis in cats
Authors: Marks Stanley L. , Cook Audrey K. , Griffey Stephen , Kass Philip H. , Rogers Quinton R. 
Published: January 2024

Abstract

Objective
To determine effects of purified and dry expanded (complex) diets on intestinal structure and function in healthy cats and in a feline model of methotrexate-induced enteritis.

Animals
19 adult specific-pathogen-free cats.

Procedure
Cats were randomized in groups to receive a purified diet intragastrically or a complex diet orally to meet their daily metabolizable energy requirements. After 21 days, cats received either methotrexate (MTX; 10 mg/kg of body weight, IV, n = 12) or saline solution IV (n = 7), and were anesthetized 72 hours later. Celiotomy was performed for aseptic removal of mesenteric lymph nodes, full-thickness biopsy of the gastrointestinal tract, and collection of aortic and portal venous blood samples for determination of arteriovenous amino acid concentrations across the intestine.

Results
MTX was associated with severe enterotoxicosis in cats receiving the purified diet, as manifested by diarrhea (4 of 6 cats) and vomiting (2 of 6 cats). One cat receiving the complex diet developed mild diarrhea, and none of these cats vomited. The purified diet was associated with marked villus blunting in the proximal and distal portions of the duodenum and increased bacterial translocation (3 of 6 cats), whereas none of the cats in the complex diet group developed bacterial translocation after MTX administration. For the cats given saline solution, bacterial translocation occurred in 1 of 4 cats receiving the complex diet versus 2 of 3 cats receiving the purified diet.

Conclusions
Feeding of a complex diet containing intact protein as the nitrogen source abrogated the proximal small intestinal atrophy and bacterial translocation associated with feeding an amino acid-based purified diet.

Clinical Relevance
Use of purified diets containing free amino acids as the only nitrogen source cannot be endorsed in human and animal cancer patients receiving systemic chemotherapy. (Am J Vet Res 1997;58:989–996)
Use of transabdominal ultrasound-guided amniocentesis for detection of equid herpesvirus 1-induced fetal infection in utero
Authors: Smith Kenneth C. , McGladdery Andrew J. , Binns Matthew M. , Mumford Jennifer A. 
Published: January 2024

Abstract

Objective
To evaluate transabdominal ultrasound-guided amniocentesis for detection of equid herpesvirus 1 (EHV-1)-induced fetal infection in utero.

Animals
4 Welsh Mountain mares.

Procedure
Pregnant mares were inoculated intranasally with EHV-1 during the ninth month of gestation. Amniocentesis was initiated on postinoculation day (PID) 12, and was performed at 2- to 3-day intervals in standing mares under deep sedation. Amniotic fluid samples were tested by virus isolation (VI), polymerase chain reaction (PCR), and immunoperoxidase cytologic examination (IC) for detection of EHV-1.

Results
Exposure to EHV-1 in the ninth month of gestation resulted in nasal shedding of infective virus, establishment of cell-associated viremia, and seroconversion. Equid herpesvirus 1 was detected by VI, PCR, and IC in amniotic fluid collected on PID 14 from 1 mare and on PID 16 and 17 from a second mare. Specimens of amniotic fluid from a third mare were VI negative until PID 18, when collections ceased, although this mare subsequently aborted an EHV-1-infected fetus on PID 28. The fourth mare aborted an EHV-1 infected fetus on PID 14. The 2 mares with VI-positive amniotic fluid were each carrying an EHV-1 infected fetus in utero, confirmed by examination of the uterus, placenta, and fetus, using specific immunohistochemistry and in situ hybridization. Endothelial cells in the endometrium and allantochorion were often virus-infected, with accompanying vascular lesions. The fetus had been infected via the chorionic vasculature in the first and fourth mares, and by inhalation of infected amniotic fluid in the second mare.

Conclusion
Amniocentesis permits specific detection of EHV-1-induced fetal infection in utero.

Clinical Relevance
Amniocentesis may have a clinical role in the specific identification and isolation of mares carrying virus-infected fetuses during EHV-1- induced abortion epizootics. (Am J Vet Res 1997;58:997–1002)
Biomechanical characterization of passive laxity of the hip joint in dogs
Authors: Smith Gail K. , LaFond Elizabeth , Heyman Steven J. , Cofone Mark A. , Gregor Thomas P. 
Published: January 2024

Abstract

Objective
To investigate the in vitro load/displacement characteristics of the hip joints in dogs as a function of joint position.

Sample Population
10 hip joints from 5 healthy dogs.

Procedure
A material test system was used to generate load/displacement curves for each joint. Joints were mounted in a custom-designed jig that held the joint in fixed anatomic orientations while plotting displacement and corresponding applied loads. All hips were cycled between 40 N of compression and 80 N of distraction. Each hip was tested at 10° increments from 30° flexion to 70° extension.

Results
When the hips were in a neutral orientation (approximately a standing position), load/displacement curves were characteristically sigmoidal (tri-phasic), indicating that, in this position, displacement was not highly dependent on load. The curves had a central low-stiffness region in which most of the lateral displacement took place. In contrast, when hips were positioned at the extremes of flexion and extension, this central, low-stiffness region was less distinct, and load/displacement curves were more linear, indicating a proportional relation between load and displacement. The load/displacement curve of 1 hip joint in the study deviated markedly from the others in a pattern consistent with cavitation of the synovial fluid.

Conclusions
When the hip joint is positioned in a neutral position, load-displacement behavior is sigmoidal, whereas when the hip joint is in an extended position, load/displacement behavior is more linear.

Clinical Relevance
Establishing load/displacement behavior of the hip joints in dogs was an important exercise in establishing the position for and estimating the repeatability of a clinical stress-radiographic method for quantitating joint laxity in dogs. (Am J Vet Res 1997;58:1078–1082)
Flow cytometric method for detecting thiazole orange-positive (reticulated) platelets in thrombocytopenic horses
Authors: Russell Karen E. , Perkins Paula C. , Grindem Carol B. , Walker Kathy M. , Sellon Debra C. 
Published: January 2024

Abstract

Objective
To evaluate a method for detecting thiazole orange-positive (TO+, reticulated) platelets in equine blood, using flow cytometry.

Animals
16 healthy, equine infectious anemia virus (EIAV)-negative horses and ponies; 9 thrombocytopenic, ElAV-positive horses and ponies; and 2 thrombocytopenic, ElAV-negative horses.

Procedure
Blood from healthy and thrombocytopenic horses was collected by jugular venipuncture. Appropriate sample requirement and incubation time for the assay were evaluated, using blood anticoagulated with EDTA or sodium citrate, or platelet-rich plasma in sodium citrate. The sample of blood or platelet-rich plasma was incubated with thiazole orange, and flow cytometric analysis was performed. Percentage of circulating TO+ platelets was determined from fluorescence (FL-1) logarithmic histograms.

Results
Healthy ponies (n = 9) had 1.28 to 2.83% (mean ± SD, 2.03 ± 0.50%) and horses (n = 7) had 0.9 to 3.44% (2.12 ± 1.14%) TO+ platelets in circulation. Thrombocytopenic ponies (n = 7) had 11.14 to 48.41 % (26.51 ± 11.99%) and thrombocytopenic horses (n = 4) had 2.33 to 8.52% (6.19 ± 2.68%) TO+ platelets in circulation. Mean platelet counts for the thrombocytopenic ponies and horses were 24,400 ± 20,500 and 39,300 ± 13,500 platelets/μl, respectively (reference range, 94,000 to 232,000 platelets/μl).

Conclusion
Thiazole orange-positive platelets can be detected in equine blood and percentages of TO+ platelets are increased in thrombocytopenic horses.

Clinical Relevance
Enumeration of TO+ platelets may prove to be a helpful noninvasive clinical measurement of bone marrow platelet production and aid in the assessment of platelet kinetics in thrombocytopenic horses. (Am J Vet Res 1997;58:1092–1096)
Infection of polarized epithelial cells with enteric and respiratory tract bovine coronaviruses and release of virus progeny
Authors: Lin Xiaoqing , O'Reilly Kathy L. , Storz Johannes 
Published: January 2024

Abstract

Objective
To investigate the susceptibility of polarized epithelioid human rectal tumor (HRT-18G) cells to bovine coronaviruses (BCV) isolated from enteric (EBCV) and respiratory (RBCV) tract infections.

Procedure
Cells of the G clone of HRT-18 were grown to confluent monolayers on permeable supports, and were directionally infected at the apical and basolateral domains with 3 wild-type BCV strains, RBCV-LSU-94LSS-051-2, RBCV-OK-0514-3, and EBCV-LY138-2, and 1 cell culture-adapted strain, EBCV-L9-80. Sequential cytopathic changes were microscopically monitored. Medium samples for titration of hemagglutinins and viral infectivity were collected directionally from both domains of the infected cell cultures at various intervals.

Results
Polarized epithelioid HRT-18G cells from apical domains had maximal susceptibility to infection with the EBCV and RBCV strains, and those from basolateral surfaces had minimal susceptibility. Titers of hemagglutinins and infective progeny BCV reached 1,280 hemagglutinin units and 4.2 × 108 plaque-forming units/ml for apical samples, but were minimal for basolateral samples. Asymmetric virus release occurred through the apical surfaces of the HRT-18G cells by 12 hours after infection when cell fusion as a sign of cytopathic changes began. When cells were infected basolaterally, progeny virions released from apical surfaces reinfected the target cells from the apical domains and induced cytopathic changes were delayed about 12 hours, compared with changes detectable in apically exposed cultures.

Conclusions
EBCV and RBCV, isolated from cattle, had marked tropism for polarized epithelioid HRT-18G cells. Entry of BCV into the polarized HRT-18G cells was effected maximally through the apical domains and minimally through the basolateral domains. Release of progeny BCV occurred preferentially from the apical domains. (Am J Vet Res 1997;58:1120–1124)
Mechanisms of acute intraocular pressure increases after phacoemulsification lens extraction in dogs
Authors: Miller Paul E. , Stanz Kimberly M. , Dubielzig Richard R. , Murphy Christopher J. 
Published: January 2024

Abstract

Objective
To investigate the mechanisms by which intraocular pressure (IOP) increases acutely after phacoemulsification (PE) lens extraction in clinically normal dogs.

Animals
24 young adult dogs.

Procedure
Intraocular pressure was monitored for up to 24 hours after unilateral intercapsular PE in 17 clinically normal, adult dogs. In 8 of these dogs, use of 2% hydroxypropyl methylcellulose (HPMC) aided capsulorhexis. Mean volume of irrigation, PE time, and power were constant between groups. After surgery, dogs were randomized then euthanatized, and eyes were examined grossly and histologically at 0 (n = 4), 3 (n = 7), and 24 hours (n = 6) after PE. Seven additional dogs underwent anterior chamber decompression alone (n = 4) or served as morphologic controls (n = 3).

Results
Intraocular pressure peaked by postoperative hour 3 at 49.9 ± 5.0 mm of Hg and normalized by 24 hours. Use of HPMC did not affect the peak or duration of IOP increase. Blood refluxed into the collecting channels and corneoscleral trabecular mesh-work in operated eyes. Computer-aided morphologic analysis indicated significant (P < 0.001) reduction in ciliary cleft cross-sectional surface area and width immediately after PE, but not after anterior chamber decompression alone. Cleft collapse was significantly (P < 0.02) greater at 24 than at 3 hours, despite return of IOP to control values by 24 hours. Plasmoid aqueous also was found in the meshwork.

Conclusions and Clinical Relevance
Sudden, large increases in IOP with few overt clinical signs may occur immediately after lens extraction in dogs. Such increases risk compromising the corneal incision and may damage the optic nerve, thereby complicating lens extraction. Structural alterations in the trabecular meshwork persist after IOP has normalized in 24 hours and may contribute to genesis of glaucoma in the late postoperative period. (Am J Vet Res 1997;58:1159–1165)
Effects of selection and habituation on vertical ground reaction force in Greyhounds
Authors: Rumph Paul F. , Steiss Janet E. , Montgomery Ronald D. 
Published: January 2024

SUMMARY

Objective
To determine effect of dog selection and habituation on vertical ground reaction force variables.

Animals
133 Greyhounds of either sex, weighing between 22 and 39 kg.

Procedure
Vertical ground reaction force variables (peak [PFz] and impulse [IFz]) for hind limbs were studied in dogs at 3 levels of habituation. Dogs of group 1 (n = 81) did not have prior experience with the gait analysis routine. Group-2 dogs (n = 52) were selected for having an amiable disposition, and were first evaluated after participating in an intermediate habituation routine (group 2a). These dogs were reevaluated after undergoing the full habituation routine (group 2b).

Results
3 of the ground reaction force variables differed significantly between dogs of groups 1 and 2 (a and b). Dogs that had not been habituated to the gait analysis routine (group 1) had significantly longer stance times than did dogs that had been more carefully selected and habituated. Intradog coefficients of variation for PFz and the IFz were significantly greater in group-1 dogs. The PFz for group-2a dogs was significantly greater than that for group-1 dogs. Differences identified between groups 2a and 2b were more likely to be attributed to habituation only. These included significantly shorter stance time and lower intradog coefficient of variation for IFz in dogs having the highest level of habituation.

Conclusion
Selection and habituation have measurable effects on vertical ground reaction force data obtained from trotting dogs. These include significantly shorter hind limb stance times, lower impulses of vertical force, with smaller coefficients of variation for peaks and impulses of vertical force within dogs.

Clinical Relevance
In controlled studies where critical decision making is based on gait analysis data, careful selection of subjects and habituation will significantly improve precision of the data and has the potential to reduce the subject or repetition sample size. (Am J Vet Res 1997;58:1206–1208)
Cardiovascular effects of buprenorphine in anesthetized dogs
Authors: Martinez Elizabeth A. , Hartsfield Sandee M. , Melendez Linda D. , Matthews Nora S. , Slater Margaret R. 
Published: January 2024

SUMMARY

Objective
To determine the cardiovascular effects of buprenorphine in isoflurane-and halothane-anesthetized dogs.

Animals
6 healthy adult hound-type dogs given buprenorphine (16 μg/kg of body weight, IV) or isovolumetric 5% dextrose solution during anesthesia with isoflurane or halothane.

Procedure
Each dog was anesthetized 4 times, with a minimum of 10 days between episodes. Anesthesia was induced with isoflurane or halothane in O2 by mask, and was maintained with 1.9% isoflurane or 1.3% halothane (end-tidal concentration). The Paco2 was maintained between 35 and 45 mm of Hg by use of mechanical ventilation, and the following variables were determined: systolic, diastolic, and mean arterial blood pressures; cardiac output; cardiac index; stroke volume; heart rate; systemic vascular resistance; mean pulmonary arterial pressure; and pulmonary vascular resistance. In addition, arterial blood samples for gas and acid-base analyses were collected at 30-minute intervals for 2.5 hours. After baseline values were recorded, dogs were randomly assigned to receive either buprenorphine (16 μg/kg, IV) or isovolumetric 5% dextrose solution. All variables were then recorded at 15-minute intervals for 2.5 hours.

Results
During isoflurane anesthesia, buprenorphine administration caused significant (P < 0.05) reductions in diastolic arterial pressure, mean arterial pressure, systolic arterial pressure, cardiac index, and heart rate, whereas systemic vascular resistance increased significantly. During halothane anesthesia, buprenorphine administration caused significant decreases in heart rate, cardiac index, mean, systolic and diastolic arterial blood pressures, and stroke volume, whereas pulmonary arterial blood pressure and systemic vascular resistance increased significantly.

Conclusion
Although the changes seen were significant, they were not sufficiently large to be of clinical importance in healthy dogs. (Am J Vet Res 1997;58:1280–1284)
Use of a breath test to determine the fate of swallowed fluids in cattle
Authors: McLeay L M. , Carruthers V. R. , Neil P. G. 
Published: January 2024

SUMMARY

Objective
To investigate a [13C]octanoic acid breath test as a means of detecting reticular groove contraction in cattle.

Animals
19 adult dairy cows with fistulated rumen, 10 yearling bulls, and 6 yearling steers.

Procedure
Cows were given 200 mg of [13C]octanoic acid in the caudal portion of the rumen, reticulum, or omasum/abomasum through the reticulo-omasal orifice, or were given the same dose of label with a drench of water or sodium bicarbonate. Collected breath was analyzed for 13C in CO2 for up to 3 hours. Breath of yearlings was analyzed for 13C in CO2 over 20 minutes after drenching with 200 mg of [13C]octanoic acid with water or sodium chloride and after sucking 200 mg of [13C]octanoic acid with molasses and water.

Results
In cows, enrichment of 13C in breath CO2 peaked at 20 to 30 minutes after placement of [13C]octanoic acid through the orifice, compared with a lower peak at 60 and 90 minutes after placement in the reticulum and rumen, respectively. The maximal increase in enrichment after placement of [13C]octanoic acid in the reticulum did not overlap with the minimal increase when placed through the reticulo-omasal orifice. Enrichment values in cows after drenching were consistent with values obtained after direct placement of [13C]octanoic acid. In yearlings, the inclusion of sodium chloride in the drench greatly increased enrichment, compared with water, but enrichment was greatest after sucking of the molasses, water, and [13C]octanoic acid combination.

Conclusions and Clinical Relevance
This breath test provides a simple, repeatable, nonradioactive, and noninvasive means of detecting the fate of swallowed fluids in cattle, thus revealing the route taken of orally administered therapeutic agents or nutrients. (Am J Vet Res 1997;58:1314–1319)