bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endotoxemia associated with experimentally induced multiple portosystemic shunts in dogs
Authors: Howe Lisa M. , Boothe Dawn M. , Boothe Harry W. 
Published: January 2024

Abstract

Objective
To document presence of endotoxin in portal and systemic blood in a model of canine multiple portosystemic shunts (PSS), and compare values in clinically normal dogs, before and after vena caval banding.

Animals
6 control dogs and 10 dogs with dimethylnitrosamine-induced multiple PSS that were subjected to vena caval banding.

Procedure
Dimethylnitrosamine was administered orally (2 mg/kg of body weight, twice weekly) to the 10 dogs in the diseased group until multiple PSS developed. Surgery was then performed on all 16 dogs (both groups), and shunts were confirmed in the diseased dogs. Blood was collected from the portal vein, hepatic vein, and caudal vena cava for baseline endotoxin determination and aerobic and anaerobic blood culturing. Baseline pressure measurements were taken from the portal venous catheter; then vena caval banding was performed. Blood for endotoxin determinations was taken from all vessels 20, 40, 60, 120, 240, and 360 minutes after banding; portal pressure measurements were taken at the same time as sample acquisition. Blood for culturing was taken from the portal and hepatic venous catheters at 120, 240, and 360 minutes after banding.

Results
Dogs in the diseased group had significantly greater overall presence of endotoxin in the portal vein (P ≤ 0.0002), hepatic vein (P ≤ 0.0001), and caudal vena cava (P ≤ 0.0004) than did control dogs. With respect to time, endotoxin presence was greater in the diseased group before banding (P ≤ 0.0002), and at 20 (P ≤ 0.0008), 40 (P ≤ 0.002), 60 (P ≤ 0.006), and 120 (P ≤ 0.01) minutes after banding.

Conclusions
Endotoxemia is more frequently present in catheterized dogs with dimethylnitrosamine-induced hepatic disease and multiple PSS, compared with clinically normal dogs. Additionally, portal pressure changes induced by vena caval banding did not affect endotoxemia.

Clinical Relevance
Endotoxemia may exist in dogs with hepatic disease and multiple PSS, and should be kept in mind when formulating treatment (particularly antimicrobial selection) for dogs with suspected endotoxemia. (Am J Vet Res 1997;58:83–88)
Actions of xylazine in young swine
Authors: de Segura I. A. Gómez , Tendillo F. J. , Mascías A. , Santos M. , Castillo-Olivares J. L. , Steffey E. P. 
Published: January 2024

Abstract

Objective
To determine sedative, analgesic, and basic cardiovascular effects of xylazine administered to pigs.

Animals
6 two-month-old Landrace x Large White pigs.

Procedure
Xylazine was administered IV at increasing dosages (1, 2, 4, 8, and 16 mg/kg of body weight) to otherwise unmedicated, conscious pigs, and the aforementioned effects were determined before xylazine administration and 2, 5, 10, and 15 minutes later. Then a higher xylazine dosage was given after the 15-minute measurements were taken.

Results
None of the xylazine dosages induced sufficient analgesia to prevent painful response to tail clamping; considerable excitation with vocalization and without appreciable sedative effect was observed at all dosages. At lower dosages, cardiovascular effects were characterized by bradycardia and biphasic blood pressure response; initial hypertension was followed by hypotension. At higher dosages, severe hypotension with moderate bradycardia was followed by marked bradycardia and return to normal baseline values or slight increase in blood pressure.

Conclusion
Xylazine did not induce adequate sedative or analgesic effects in pigs at any dosage tested; however, cardiovascular effects were considerable. These effects of xylazine differ from those observed in other domestic species. (Am J Vet Res 1997;58:99–102)
Effect of H1-antihistamines on histamine release from dispersed canine cutaneous mast cells
Authors: García Gloria , DeMora Fernando , Ferrer Lluís , Puigdemont Anna 
Published: January 2024

Abstract

Objective
Because of the implication of histamine in canine atopic dermatitis, H1-antihistamines may provide a valid alternative to glucocorticoid therapy. In vitro study of these drugs prior to clinical testing can allow the most promising compounds to be selected for trials and render trials with drugs of doubtful efficacy unnecessary.

Sample Population
Isolated canine cutaneous mast cells.

Procedure
Cells were preincubated with antihistamines at increasing concentrations and incubated with concanavalin A (1,000 µg/ml), calcium ionophore A23187 (1 µM), and substance P (100 µM). Compound 48/80 was not used because it proved to be cytotoxic.

Results
Generally, significant prodegranulating effect was not observed for most of the studied agents. Only terfenadine increased spontaneous histamine release at concentrations > 30 µM. Cetirizine did not block histamine release at any of the studied concentrations. Ketotifen had a low inhibitory effect only at the highest concentration (100 µM) after concanavalin A- (23.6 ± 2.8%) and calcium ionophore A23187- (29.8 ± 3.0%) induced release. Terfenadine caused a concentration-dependent inhibitory effect after ionophore A23187- (48.1 ± 2.2%) and concanavalin A- (28.9 ± 2.3%) activation, but was inactive against substance P-induced release. In contrast, loratadine had potent dose-dependent inhibition of concanavalin A- and ionophore A23187-induced histamine release, with maximal effect of 85.6 ± 3.1 % and 62.6 ± 4.7%, respectively, at 100 µM concentration. After substance P activation, histamine release was only slightly inhibited by loratadine (14.8 ± 1.1%).

Conclusions
This study documents the behavior of isolated canine cutaneous mast cells in the presence of nonimmunologic stimulation. Using this in vitro method, we were able to determine that loratadine is the only antihistamine that has potent inhibition of histamine release from dog cutaneous mast cells without a substantial prodegranulating effect. Loratadine is, therefore, a good candidate for clinical testing. (Am J Vet Res 1997;58:293–297)
Effect of heartworm infection on in vitro contractile responses of canine pulmonary artery and vein
Authors: Maksimowich Daria S. , Mupanomunda Maria , Williams Jeffrey F. , Kaiser Lana 
Published: January 2024

Abstract

Objective
To test the effect of heartworm infection on agonist-induced constriction of canine pulmonary artery and vein in vitro.

Procedure
Cumulative concentration-response relations to norepinephrine, serotonin, histamine, prostaglandin F2α, and the thromboxane A2 analog U-44069 were determined, using isolated rings of pulmonary artery and vein from control and heartworm-infected dogs. To determine the role of endothelial cells in histamine constriction, some rings were denuded of endothelial cells in both artery and vein.

Animals
Noninfected control and heartworm-infected dogs.

Results
There was no difference in constriction response to norepinephrine, serotonin, prostaglandin F2α, or U44069 of pulmonary artery or vein from control or heartworm-infected dogs. Histamine-induced constriction of pulmonary artery from heartworm-infected dogs was not different from control values, however, when endothelial cells were removed from control, but not heartworm-infected pulmonary artery, histamine-induced constriction was enhanced. Histamine-induced constriction of pulmonary vein from heartworm-infected dogs was significantly depressed, compared with that of control pulmonary vein. However, removal of endothelial cells in pulmonary vein from heartworm-infected, but not control dogs significantly increased constriction.

Conclusion
Heartworm infection alters histamine-induced constriction responses of pulmonary artery and vein. These changes may reflect high circulating histamine concentrations in heartworm-infected dogs, compared with that in controls. Increased circulating histamine concentrations in vivo could bring about decreased sensitivity of histamine receptors or decreases in the number of receptors expressed.

Clinical Relevance
Mast cells and histamine may be important factors in altered endothelium-mediated responses associated with heartworm disease. (Am J Vet Res 1997;58:394–397)
Comparison of intratumoral administration of cisplatin versus bleomycin for treatment of periocular squamous cell carcinomas in horses
Authors: Théon A. P. , Pascoe J. R. , Madigan J. E. , Carlson G. , Metzger L. 
Published: January 2024

Abstract

Objective
To compare therapeutic benefits of intratumoral administration of cisplatin and bleomycin for squamous cell carcinoma of the eyelids in horses.

Animals
25 horses with 27 T2-stage periocular squamous cell carcinomas.

Procedure
Horses were treated 4 times at 2-week intervals with a slow-release formulation of cisplatin (1 mg/cm3 of tissue) or bleomycin (1 IU/cm3 of tissue). A two-stage design was used to minimize the sample size in each treatment arm.

Results
The local control rate at 1 year for lesions treated with cisplatin was 93 ± 6%, and with bleomycin was 78 ± 10%. Difference in local control duration between the 2 treatment groups was not significantly different. A high tumor proliferative fraction index value was associated with a higher local (in-field) control rate, but also with a higher risk of marginal and regional recurrences. Tumors with a low proliferative fraction index value (< 28%) had 9.5-times higher (P = 0.0411) risk of recurrence than those with a high index value. Local acute reactions were similar in the 2 treatment groups, and chronic reactions were not observed.

Conclusions
Cisplatin and bleomycin were effective anticancer agents for carcinoma of the eyelid in horses. Based on therapeutic benefit and treatment cost, cisplatin was found to be a better choice for intratumoral chemotherapy of eyelid carcinomas.

Clinical Relevance
Results of this study confirm the value of intratumoral chemotherapy, using cisplatin, for treatment of cutaneous squamous cell carcinomas in horses. (Am J Vet Res 1997;58:431–436)
Effects of three sedative protocols on glomerular filtration rate in clinically normal dogs
Authors: Newell Susan M. , Ko Jeff C. , Ginn Pamela E. , Heaton-Jones Terrell G. , Hyatt Debra A. , Cardwell Amy L. , Mauragis Danielle F. , Harrison Jay M. 
Published: January 2024

Abstract

Objective
To determine the effects of 3 sedative protocols (butorphanol and diazepam [BD] IV; acepromazine and butorphanol [AB] IV; diazepam and ketamine [DK] IV) on glomerular filtration rate (GFR) as measured by 99mTc DTPA nuclear scintigraphy and to compare them with GFR measured without sedation. Cardiovascular, respiratory, and sedative effects of each protocol also were measured.

Animals
12 adult male Walker Hounds.

Procedure
Systolic, diastolic, and mean arterial blood pressures and heart and respiratory rates were measured before, during, and after scintigraphic measurement of GFR.

Results
Difference in GFR was not significant between any of the sedative regimens and the control. The DK protocol caused significant increases in systolic, diastolic, and mean arterial blood pressure; compared with the AB and BD protocols, it caused significant increases in heart rate versus all protocols, and was associated with the lowest mean GFR (2.80 ml/min/kg of body weight). The AB protocol caused significant decreases in systolic, diastolic, and mean arterial blood pressures, compared with DK and the nonsedation protocols. Mean GFR for the BD protocol was 2.94 ml/min/kg, and was 3.13 ml/min/kg for the AB and the nonsedation protocols. The AB protocol provided the best sedation with minimal additional restraint required. The BD and nonsedation protocols often were associated with substantial dog movement. The DK protocol induced inadequate duration of immobilization (< 10 minutes) in some dogs and excitement in others.

Conclusion
GFR measurements obtained with any of the sedative protocols were not significantly different, compared with measurements in awake dogs. The AB protocol provides the best sedative effects and was associated with GFR values identical to those in awake dogs. Systemic hypotension caused by acepromazine did not decrease GFR in clinically normal dogs. (Am J Vet Res 1997;58:446–450)
Chromogranin A plasma concentration and expression in pancreatic islet cell tumors of dogs and cats
Authors: Myers Nathaniel C. , Andrews Gordon A. , Chard-Bergstrom Cindy 
Published: January 2024

Abstract

Objectives
To describe expression of the neuroendocrine marker chromogranin A (CgA) in canine and feline pancreatic islet cell tumors and their metastases, and to evaluate plasma CgA concentration in dogs and cats with insulinoma.

Sample Population
Paraffin-embedded tissues from 25 canine and 2 feline pancreatic islet cell tumors, 5 canine and 6 feline exocrine pancreatic tumors, and normal pancreatic tissue from 2 dogs and 2 cats. Heparinized plasma samples from 3 dogs and 2 cats diagnosed with insulinoma, and 10 control plasma samples from each species.

Procedure
Immunohistochemical analysis was performed on the 42 tissue specimens, using antisera against CgA, neuron-specific enolase, insulin, somatostatin, glucagon, and pancreatic polypeptide. The 25 plasma samples were evaluated, using a soluble-phase, double-antibody, equilibrium radioimmunoassay directed against the amino- and carboxy-terminal peptides of bovine CgA.

Results
Chromogranin A expression was found in 76% of canine and 2 of 2 feline pancreatic islet cell tumors. Of 7 animals with CgA immunoreactivity in primary tumors, 6 also had CgA immunostaining of metastatic lesions. Plasma CgA concentration in 2 dogs with insulinoma (0.9, 1.0 ng/ml) exceeded the reference range established for 10 clinically normal control dogs (0.50 ± 0.16 ng/ml). Feline plasma CgA samples had extensive nonspecific background immunoreactivity.

Conclusions
Chromogranin A is a useful immunohistochemical marker for pancreatic tumors of neuroendocrine origin and their metastases. Plasma CgA concentration determined by radioimmunoassay was high in 2 dogs with insulinoma.

Clinical Relevance
Immunohistochemical staining of tissues or cytologic specimens for CgA and/or neuron-specific enolase may help distinguish masses of unknown origin as neuroendocrine in nature. Increase in plasma CgA concentration may be useful diagnostically for animals with suspected neuroendocrine tumors. (Am J Vet Res1997;58:615–620)
Effect of sodium bicarbonate administration on renal function of horses
Authors: Rivas Luis J. , Hinchcliff Kenneth W. , Kohn Catherine W. , Sams Richard A. , Chew Dennis J. 
Published: January 2024

Abstract

Objectives
To describe changes in renal function of horses after oral and IV administration of sodium bicarbonate (NaHCO3) and to determine whether changes are dose dependent.

Animals
6 Standardbred mares.

Procedure
Blood and urine samples for determination of renal function were collected immediately before and at hourly intervals for 12 hours after administration of each of 3 oral doses (1,500, 1,000, and 250 mg/kg of body weight, in 3 L of water) and 1 IV dose (250 mg/kg, 5% solution) of NaHCO3, or water (3 L orally).

Results
NaHCO3 induced increases in urine flow; electrolyte-free water reabsorption; urine concentrations of sodium and bicarbonate; fractional excretion of sodium, potassium, chloride, and bicarbonate; urinary excretion and clearance of sodium and bicarbonate; urine pH and anion gap; and mean plasma concentration of antidiuretic hormone. NaHCO3 induced attenuation in reduction with time of urine excretion and clearance of potassium, chloride, and osmoles, and induced reduction in urine osmolality. Plasma aldosterone and atrial natriuretic peptide concentrations and glomerular filtration rate were not modified.

Conclusions
Renal responses to NaHCO3 load emphasize conservation of plasma volume and re-establishment of acid-base balance over control of hyperosmolality by means of diuresis, natriuresis, and increased bicarbonaturia. These responses imply a large fluid shift from the extravascular space to the vascular compartment, which was eliminated via diuresis, thus preventing hypervolemia. (Am J Vet Res 1997;58:664–671)
Profile of electrodiagnostic abnormalities in cats with GM1 gangliosidosis
Authors: Steiss J. E. , Baker H. J. , Braund K. G. , Cox N. R. , Wright J. C. 
Published: January 2024

Abstract

Objective
To determine which electrodiagnostic tests yield abnormal findings in cats with GM1 gangliosidosis, and to determine the approximate age of onset of electrodiagnostic abnormalities.

Animals
Cats (28 to 335 days old) affected with GM1 gangliosidosis (n = 11) and unaffected controls (n = 14).

Procedure
Cats were grouped by age: group 1, ≤ 90 days; group 2, 91 to 200 days; and group 3, > 200 days. Electrodiagnostic tests were conducted, including needle electromyography, motor and sensory nerve conduction velocity, spinal evoked potentials, and brainstem auditory evoked potentials. Results for control and affected cats were compared, using the general linear model for ANOVA and Scheffe's test for multiple comparisons.

Results
Needle electromyography did not reveal abnormal spontaneous activity in skeletal muscles of any cat; furthermore, statistical analysis did not indicate significant difference between affected and control groups for nerve conduction velocity, confirming that degeneration of peripheral nerve fibers is not a feature of this disease. However, spinal evoked potentials were abnormal in group-3 cats; conduction velocity within sensory pathways in the cranial part of the spinal cord was significantly slower in GM1-affected cats (P = 0.0002). Brainstem auditory evoked responses also were abnormal: wave V (generated in the region of the pons) had prolonged latency in cats of groups 2 and 3 (P = 0.0003 and 0.0001, respectively, at 90 decibels sound pressure level). In the oldest cats, latencies for earlier waves within the auditory pathway also were prolonged; wave I (generated by the cochlear nerve) was prolonged in group-3 cats (P = 0.0423).

Conclusion
Motor and sensory nerve conduction velocities remained within normal limits in GM1-affected cats. However, spinal evoked potentials indicated slowing in conduction velocity along the cranial part of the spinal cord in group 3 cats. Brainstem auditory evoked responses indicated prolonged latencies in cats of groups 2 and 3. (Am J Vet Res 1997;58:706–709)
Cortisol suppression in cats after induction of anesthesia with etomidate, compared with ketamine-diazepam combination
Authors: Moon Paula F. 
Published: January 2024

Abstract

Objective
To evaluate duration and magnitude of adrenocortical function suppression after administration of etomidate to cats.

Animals
15 purpose-bred, healthy cats.

Procedure
Cats were allotted to 2 groups. Anesthesia was induced with etomidate (ET, 2 mg/kg of body weight, IV; n = 8) or a mixture (KD, n = 7) of ketamine (5 mg/kg, IV) and diazepam (0.25 mg/kg, IV). Anesthesia was maintained with halothane in all cats for 2 hours. ACTH gel (2.2 U/kg, IM) was administered 30 minutes after anesthesia induction. Blood samples for cortisol assay were taken before anesthesia induction (T −30), and before (TO) and at 30, 60, 120, 180, 300, and 420 minutes after ACTH administration. Anesthesia was discontinued after the T120 sample was obtained.

Results
After anesthesia induction, median (interquartile range [Q1-Q3]) cortisol values were significantly lower in the ET group (4 [3 to 4] μg/dl) at TO, compared with T −30 values and with TO values in the KD group (5 [3 to 9] μg/dl). After ACTH administration, cortisol values in the ET group continued to decrease two- to threefold below T −30 values and remained decreased over the 2-hour anesthesia period. After ACTH administration, cortisol values increased twofold for 2 hours in the KD group, compared with T −30 values. One hour after anesthesia recovery, cortisol values in the ET group (3 [2 to 3] μg/dl) remained significantly lower than values in the KD group (9 [7 to 11] μg/dl) and preanesthesia values. By T300, both groups had cortisol concentration near 7 μg/dl, similar to preanesthesia values.

Conclusion
Induction of anesthesia with etomidate caused suppression of adrenocortical function during 2 hours of halothane anesthesia and 1 hour of recovery in cats. Cortisol concentration did not return to baseline until after 2 additional hours.

Clinical Relevance
Results from these healthy cats suggest profound suppression of important stress hormones after anesthesia induction with etomidate, use of which could put critically ill cats at further risk. (Am J Vet Res 1997;58:868–871)
Hormonal modulation of the physiologic responses of calves infected with Eimeria bovis
Authors: Heath H. L. , Blagburn B. L. , Elsasser T. H. , Pugh D. G. , Sanders L. G. , Sartin E. A. , Steele B. , Sartin J. L. 
Published: January 2024

Abstract

Objective
To determine whether an estradiol-progesterone (EP) growth implant would have an effect on febrile responses and on the catabolic component of Eimeria bovis infection.

Animals
27 Holstein bull calves.

Procedure
Calves were assigned to treatment groups as: control (n = 5), EP implant (EP, n = 5), E bovis-inoculated (coccidia: C, n = 7), pair fed (n = 4), or EP plus E bovis-inoculated coccidia (EP/C, n = 6) groups. Calves were provided subcutaneous EP implants at 8 weeks of age, and were inoculated with 2 × 105 oocysts of E bovis at 11 weeks of age. Body weight was measured on postinoculation day (PID) 0, 14, and 28. Rectal temperature and food intake were determined and fecal samples were collected daily from PID 15 to 28. Blood samples were collected on PID 24 for analysis of CD2+, CD4+, and CD8+ antigens and plasma insulin-like growth factor I concentration. Blood samples were collected at 15-minute intervals for measurement of pulsatile growth hormone release.

Results
Group-EP/C calves had fever for 2 days versus 5 days for group-C calves (P < 0.05). These calves had diarrhea for fewer days than did their group-C counterparts (P < 0.05). Fibrinogen and glucose values were high in group-C (P < 0.05) but not group-EP/C calves. The latter had positive weight gain from PID 14 to 28, whereas group-C calves had weight loss (P < 0.05). Plasma insulin-like growth factor I concentration was reduced by infection (P < 0.05). EP-treated noninfected calves had increased numbers of CD2+, CD4+, and CD8+ blood mononuclear cells (P < 0.05).

Conclusions
EP has a protective effect in calves infected with E bovis. This may relate to changes in immune function induced by EP.

Clinical Relevance
Treatment of calves with EP could offer some protection against the often severe wasting and debilitation associated with E bovis infection. (Am J Vet Res 1997;58:891–896)
Effect of combined administration of insulin-like growth factor and platelet-derived growth factor on the regeneration of transected and anastomosed sciatic nerve in rats
Authors: Welch Janet A. , Kraus Karl H. , Wells Michael R. , Blunt Dana G. , Weremowitz J. 
Published: January 2024

Abstract

Objective
To evaluate the efficacy of combined administration of platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF-I) on the regeneration of transected and anastomosed sciatic nerves.

Animals
25 male Lewis rats.

Procedure
Transection and anastomosis was performed of the left sciatic nerve of all rats. At the time of surgery, treatment group rats received a combination of PDGF (0.75 μg) and IGF-I (1.5 μg) along with vehicle (2% methyl cellulose gel) at the anastomosis site. Control rats received vehicle alone. Evaluation consisted of motor evoked potentials and nerve conduction velocity, quantitative histologic examination, sciatic functional index, and visual assessment of repair organization (lesion scores).

Results
Significant differences in motor evoked potential latency, nerve conduction velocity, axon number, sciatic functional index, or lesion scores were not found between groups.

Conclusions
Combined administration of PDGF and IGF-I did not enhance peripheral nerve regeneration in a transection and anastomosis model as determined 6 weeks after surgery.

Clinical Relevance
These findings support the assumption that mechanical, versus trophic, effects predominate when nerve ends are closely apposed. (Am J Vet Res 1997;58:1033–1037)