bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of chronotropic and dysrhythmogenic effects of atropine in dogs with bradycardia
Authors: Rishniw Mark , Tobias Anthony H. , Slinker Bryan K.
Published: January 2024

Objective

To characterize the magnitude, character, and time course of chronotropic and dysrhythmogenic responses of dogs with vagally mediated bradycardia to atropine sulfate.

Design

Latin square design.

Animals

Seven clinically normal adult mixed-breed dogs.

Procedure

Vagally mediated bradycardia was induced with morphine and fentanyl citrate. Atropine (0.02 mg/kg of body weight) was administered IV, SC, or IM. Electrocardiograms were recorded continuously for 5 minutes before and for 35 minutes after atropine administration or until a sustained parasympatholytic response was observed. Data were digitized, analyzed independently for changes in atrial and ventricular rate, and compared between different routes of administration.

Results

All dogs developed second-degree atrioventricular (AV) block after IV administration of atropine, and 71% of dogs developed AV block after SC or IM administration. The AV block arose and resolved more rapidly with IV administration than with SC or IM administration. The AV block was principally attributable to an increase in the atrial rate prior to increases in the ventricular rate. Atropine, regardless of route of administration, potentiated baseline ventricular bradycardia in 62% of the experiments (mean heart rate decrease of 16 beats/min; decreased to < 20 beats/min in 2 dogs for ≤ 10 seconds). Duration of the bradycardic potentiation was longer with SC administration (9.1 minutes, SC, vs 1.4 minutes, IV, and 4.6 minutes, IM). Parasympatholytic rate was higher for IV than SC or IM administration (128 beats/min vs 92 beats/min and 101 beats/min). Two dogs given atropine SC failed to resolve the AV block and attain sinus rhythm.

Conclusions

Administration of 0.02 mg of atropine/ kg by IV, IM, and SC routes for vagally mediated bradycardia in dogs consistently induces AV block and occasional brief potentiation of ventricular bradycardia.

Clinical Relevance

Parasympathomimetic effects occur and resolve most rapidly and consistently, and the stable parasympatholytic effect is of greatest magnitude after IV administration. Thus, vagally mediated bradycardia in clinically normal dogs appears to be best abolished by IV administration of atropine.(Am J Vet Res 1996;57:337-341)
Cardiopulmonary effects of desflurane in cats
Authors: McMurphy R. M. , Hodgson D. S.
Published: January 2024

Objective

To evaluate the cardiopulmonary effects of 2 anesthetic planes of desflurane (DES) during spontaneous ventilation (SV) and controlled ventilation (CV) in cats.

Design

Repeated Latin square.

Animals

Eight healthy adult cats.

Procedure

Each cat received 1.3 times the minimum alveolar concentration (MAC) of DES and 1.7 MAC of DES in oxygen during CV and SV. The data were analyzed as a repeated measures design. Heart rate, cardiac output, arterial blood pressure, pulmonary artery pressure, respiratory rate, PaO2, PaCO2, pHa, PCV, and serum total protein concentration were measured during each treatment. Stroke volume, cardiac index, total peripheral resistance, and oxygen consumption were calculated.

Results

Cardiac index and stroke volume were not different between 1.3 and 1.7 MAC of DES, but CV decreased cardiac index and stroke volume (P < 0.05). Systolic arterial pressure was decreased during 1.7 MAC of DES and during CV. Mean arterial blood pressure was decreased at 1.7 MAC during CV, but not SV. The Paco2 was higher at 1.7 MAC than at 1.3 MAC during SV. Spontaneously ventilating cats at 1.7 MAC had higher pulmonary artery pressures than other treatments. The PCV was decreased during CV.

Conclusion

1.7 MAC of DES causes decreased systolic and mean arterial pressures and marked hypercapnia, but cardiac index is not affected. The hypercapnia is probably responsible for the increased pulmonary artery pressures in the spontaneously ventilating cats during 1.7 MAC. Hypercapnia can be corrected by CV but this reduces cardiac output.(Am J Vet Res 1996;57:367-370)
Noninvasive kinematic analysis of the walk in healthy large-breed dogs
Authors: Hottinger Heidi A. , DeCamp Charles E. , Olivier N. Bari , Hauptman Joe G. , Soutas-Little Robert W.
Published: January 2024

Objectives

To use computer-assisted kinematic analysis to describe the walk in healthy dogs and to adapt Fourier transformation for analysis of the data.

Design

Evaluation of normal walk in dogs, using kinematic and force plate analysis.

Sample Population

15 healthy large-breed dogs.

Procedure

Morphometric data were collected to describe the sample population. Temporal and distance variables were measured to describe the walk. Flexion and extension movements were described for the scapulohumeral, cubital, carpal, coxofemoral, femorotibial, and tarsal joints. Fourier transformation was adapted to facilitate analysis of the joint angle waveforms.

Results

Unique and complex patterns of flexion and extension movements were observed for each joint studied. The walk had consistency of movement in the sample population in temporal and distance variables and joint movements. Variances attributable to intra- and interdog differences were similar and 1 to 2 orders of magnitude smaller than the mean Fourier coefficients from which they were calculated for all 6 joints. The number of essential Fourier coefficients required to represent the joint angle waveforms was 3 for the coxofemoral joint, 5 each for the femorotibial, scapulohumeral, cubital, and carpal joints, and 6 for the tarsal joint.

Conclusions

Computer-assisted kinematic gait analysis proved to be a reliable and consistent technique for assessment of movement at the walk in dogs, and Fourier transformation was shown to be an effective tool for analysis of the kinematic data.

Clinical Relevance

The database derived from the normal sample population in this study can be used as a model of musculoskeletal function at the walk for future comparisons with disease and treatment.(Am J Vet Res 1996;57:381-388)
Immunohistolocalization of the carbonic anhydrase isoenzymes (CA-I, CA-II, and CA-III) in the reproductive tract of male horses
Authors: Asari Masao , Sasaki Kiyoaki , Miura Kohshi , Ichihara Nobutsume , Nishita Toshiho
Published: January 2024

Objective

To elucidate locations of cytosolic carbonic anhydrase isoenzyme (CA-I, CA-II, and CA-III)-positive epithelial cells in equine male reproductive organs.

Design

Descriptive and immunohistochemical study.

Animals

4 clinically normal male horses.

Procedure

The testis (seminiferous tubules, rete tubules), epididymis (initial, middle, and terminal segments), proximal and distal portions of the ductus deferens, ampulla ductus deferentis, seminal vesicle, prostate, and bulbourethral gland were excised from euthanatized horses after administration of an overdose of pentobarbital. The tissue specimens were quickly placed in fixative solution, dehydrated in ethanol, and embedded; then thin sections were cut. For immunohistochemical staining, antibodies against purified equine CA-I, CA-II, and CA-III were raised in rabbits. After examination of the specificity of each antiserum, the monospecific antisera against carbonic anhydrase isoenzymes were used to localize the isoenzymes.

Results

Specific staining for CA-III was found in the Sertoli and basal cells of the ductus deferens. Most of the testicular and epididymal tissue, as well as ductus deferens, were virtually negative for the enzymes when stained with the antibody to CA-I and CA-II. In the initial segment of the epididymis, a few principal cells had intense cytoplasmic staining with anti-CA-II. In the male accessory glands, CA-I, CA-II, and CA-III were detected in the epithelial cells of the seminal vesicle, prostate, and bulbourethral gland.

Conclusions

In the equine male reproductive tract, the bicarbonate in semen originates mainly from accessory reproductive glands. All 3 isoenzymes may have central roles in the regulation of bicarbonate concentration in seminal plasm and, accordingly, regulate seminal plasma pH. Distribution of CA-III in Sertoli and basal cells of the ductus deferens suggests other specialized physiologic roles. (Am J Vet Res 1996;57:439–443)
Intramammary defense against infections induced by Escherichia coli in cows
Authors: Paape Max J. , Lilius Esa-Matti , Wiitanen Paulina A. , Kontio Meri P. , Miller Robert H.
Published: January 2024

Objective

To examine Escherichia coli lipopolysaccharide (LPS) effects on expression of CD14 and CD18 cell surface receptors and lectin/carbohydrate-mediated nonopsonic phagocytosis of E coli.

Design

Cell isolation, monoclonal antibody, phagocytosis, and flow cytometric studies.

Animals

4 clinically normal lactating Holstein cows for studies on CD14 and CD18, and 2 for phagocytosis studies.

Procedure

Binding of CD14 and CD18 monoclonal antibodies to blood and milk neutrophils and mononuclear leukocytes was studied by flow cytometry before and after intramammary injection of LPS, and nonopsonic phagocytosis of E coli by blood neutrophils was determined. Presence of intracellular CD14 was determined after in vitro incubation of neutrophils in skimmed milk and after fixation and permeabilization of freshly isolated neutrophils.

Results

Before LPS injection, percentages of blood neutrophils and large mononuclear (LMO) cells expressing CD14 averaged 3 and 63% and 68 and 35% for mammary neutrophils and LMO cells, respectively. After LPS injection, CD14 was only detected on blood and mammary LMO cells (61 and 25%); receptor expression increased by 1.8- and threefold, respectively. In vitro incubation of neutrophils in skimmed milk increased the percentage of neutrophils expressing CD14. The number of blood neutrophils staining positive for CD14 increased after permeabilization of the plasma membrane, which was blocked by unlabeled anti-CD14 monoclonal antibodies. Before LPS, percentages of blood neutrophils and LMO cells expressing CD18 averaged 93 and 95% and was 88 and 55% for mammary neutrophils and LMO cells, respectively. After LPS, percentages of mammary neutrophils and LMO cells expressing CD18 increased to 100 and 95%, respectively. Expression of CD18 was 2.6-fold higher for mammary neutrophils before injection of LPS, compared with blood neutrophils, either before or after LPS. In absence of opsonins, neutrophils with adherent and phagocytosed E coli averaged 83 and 14%.

Conclusions

LPS modulated expression of CD14 and CD18 and lectin-carbohydrate interactions mediated nonopsonic phagocytosis of E coli. An intracellular pool of CD14 exists in bovine neutrophils and is capable of translocating to the cell surface.

Clinical Relevance

Development of methods to maximize expression of CD14 receptors on mammary neutrophils involved in production of tumor necrosis factor-α, and nonopsonic phagocytosis could result in reducing prevalence of mastitis in dairy cows. (Am J Vet Res 1996;57:477–482)
Comparison of sedative and cardiorespiratory effects of medetomidine and medetomidine-butorphanol combination in dogs
Authors: Ko Jeff C. H. , Bailey James E. , Pablo Luisito S. , Heaton-Jones Terrell G.
Published: January 2024

Objective

Sedative, cardiorespiratory, and analgesic effects of intramuscular administration of medetomidine (40 µg/kg of body weight)-glycopyrrolate (0.01 mg/kg) and medetomidine (10 µg/kg)-butorphanol (0.2 mg/kg)-glycopyrrolate (0.01 mg/kg) combinations were compared. Additional evaluations were done on reversal of medetomidine, using atipamezole (200 µ g/kg, IV), after 90 minutes of medetomidine-induced sedation.

Design

Crossover study, with each dog receiving each drug combination at 1-week intervals.

Animals

Six 2-year-old English hound-type dogs.

Procedure

Arterial blood pressure, ECG, respiratory rate, tidal volume, minute volume, arterial blood gas tensions, and serum biochemical variables were measured before, during, and after sedation. Analgesia was evaluated by needle prick on the skin and tail clamp.

Results

Heart rate decreased significantly from 100 beats/mm to <40 beats/min within 3 minutes of injection of medetomidine and medetomidine. and butorphanol (MB). Mean arterial blood pressure in both groups were maintained above 100 mm of Hg throughout the recording period. There was no significant difference between medetomidine and MB in respiratory rate, tidal volume, and minute ventilation. Hypoxemia (PaO2 < 60 mm of Hg) was observed at 10 and 20 minutes in 2 dogs given MB. Atipamezole administration in the dogs given medetomidine significantly increased PaO2 and returned the values to baseline. Needle prick analgesia duration was longer in the medetomidine (80 ± 7.7 minutes) than MB (56.0 ± 19.2 minutes) group. Tail pinch analgesia was variable in both groups. Duration of lateral recumbency was longer after medetomidine (90 ± 0 minutes) than MB (73.5 ± 19.0 minutes).

Conclusion

Medetomidine and MB were effective combinations for mildly invasive procedures.

Clinical Relevance

MB induced a shorter period of analgesia and recumbency than did medetomidine. (Am J Vet Res 1996;57:535–540)
Effects of oral lactose and xylose loads on blood glucose, galactose, xylose, and insulin values in healthy calves and calves with diarrhea
Authors: Gutzwiller A. , Blum J. W.
Published: January 2024

Objective

2 hypotheses were tested: calves with acute, mild diarrhea digest lactose less efficiently than healthy calves, and they are in a catabolic state, which influences plasma glucose concentration after glucose absorption.

Design

Clinical study; 2 treatments with 10 repetitions/treatment.

Animals

20 preruminant Brown Swiss and Simmental Red Holstein calves; 10 calves with mild diarrhea, and 10 age-matched healthy calves.

Procedure

Blood metabolite and hormone concentrations were determined before and after an oral lactose load. Plasma xylose concentration was determined after an oral xylose load. Ill calves were tested 1 day after the onset of diarrhea.

Results

Calves with diarrhea (cryptosporidia, coronavirus) had lower preprandial concentrations of plasma glucose, insulin-like growth factor I, and 3,5,3’-triiodothyronine (P < 0.01) and a higher concentration of free fatty acids (P = 0.03) than did healthy calves. After the oral lactose and xylose loads, blood galactose and plasma xylose concentrations were lower in ill calves (P = 0.10 and P = 0.07, respectively). In calves with diarrhea, there was a larger increase of plasma glucose concentration (P =0.12) and a smaller increase of plasma insulin concentration (P = 0.04) above baseline values after lactose ingestion.

Conclusions

Lactose digestion is slightly impaired in calves with mild diarrhea. Calves with acute diarrhea are in a catabolic state and, therefore, respond with a larger increase of plasma glucose concentration to a given amount of absorbed glucose than do healthy calves.

Clinical relevance

Plasma glucose concentration is not a reliable measure for glucose absorption in animals that are in a catabolic state. (Am J Vet Res 1996;57:560–563)
Benign familial hyperphosphatasemia in Siberian Huskies
Authors: Lawler D. F. , Keltner D. G. , Hoffman W. E. , Nachreiner R. F. , Hegstad R. L. , Herndon P. A. , Fischer B. J.
Published: January 2024

Objective

To evaluate benign familial hyperphosphatasemia involving serum alkaline phosphatase (SAP) in pups.

Design

Pups with markedly increased SAP activity were evaluated and compared with unaffected siblings, and with other unaffected Siberian Husky pups from the same colony.

Animals

8 related litters of Siberian Husky pups (n = 56).

Procedure

At ages 11 and 16 weeks, pups were given physical examinations and blood was obtained for hematologic and serum biochemical analyses (including electrolytes and isoenzymes of alkaline phosphatase), ionized calcium concentration, and serum parathyroid hormone concentration. Diet, growth and health performance, skeletal radiographs, and genealogical data also were evaluated.

Results

Of 42 pups tested, 17 had markedly high total SAP values. Mean total SAP activity of affected pups at ages 11 and 16 weeks was over 5 times greater than mean total SAP activity of unaffected siblings and other unaffected Siberian Husky pups of the same age (P <0.001). Clinical, radiologic, and biochemical evaluation of the subjects revealed no other abnormal findings. The source of the increased SAP activity was characterized in 5 affected pups as bone isoenzyme. The mode of inheritance could not be deduced from the data, but the trait clearly is familial and autosomal.

Conclusion

The condition described in the family of Siberian Huskies bears similarity to human benign, persistent, familial hyperphosphatasemia.

Clinical Relevance

Benign familial hyperphosphatasemia should be considered in the differential diagnosis of markedly increased SAP activity in young dogs. (Am J Vet Res 1996; 57:612–617)
Venereal shedding of ovine lentivirus in infected rams
Authors: de la Concha-Bermejillo A. , Magnus-Corral S. , Brodie S. J. , DeMartini J. C.
Published: January 2024

Objective

To assess shedding of ovine lentivirus (OvLV) in semen of infected rams with or without epididymitis.

Design

Rams 1 and 2 were naturally infected with OvLV. Rams 3-6 were inoculated with OvLV strain 85/ 34. Ram 7 was inoculated with uninfected cell culture supernatatant (OvLV-negative control). 14 weeks after OvLV inoculation, rams 1-3, 6, and 7 were inoculated with Brucella ovis into the epididymis. Ram 4 was a natural case of B ovis epididymitis, and ram 5 was left non-inoculated (Bovis-negative control). Blood mononuclear cells (BMNC) and semen were collected between 0 and 44 weeks after OvLV inoculation.

Animals

Seven 2- to 3-year-old rams.

Procedure

Infective OvLV in BMNC and semen was determined by virus isolation and subsequent OvLV-DNA amplification by polymerase chain reaction (PCR). Bronchoalveolar lavage cells collected after death were used for DNA extraction and PCR amplification.

Results

OvLV was detected in the semen of rams 3 and 6, but only after Bovis inoculation. OvLV was isolated consistently from BMNC of rams 3 and 6, but only occasionally from rams 1, 2, 4, and 5. Leukocytospermia was evident in every ejaculate of all Bovis-infected rams after infection. Semiquantitative PCR determination of OvLV DNA from bronchoalveolar lavage cells revealed the highest OvLV DNA load in rams 3 and 6.

Conclusions

Leukocytospermia and a high virus load in infected animals are important factors that determine shedding of OvLV in semen.

Clinical Relevance

Dissemination of OvLV through contaminated semen could have important implications in the epidemiology and control of this infection. (Am J Vet Res 1996; 57:684–688)
Expression of the oncogene c-erbB-2 in canine mammary cancers and tumor-derived cell lines
Authors: Ahem Terry E. , Bird R. Curtis , Bird Allison E. Church , Wolfe Lauren G.
Published: January 2024

Objective

To determine, for canine mammary tumors, whether malignancy, with or without local invasion or regional metastasis, was associated with overexpression of the oncogene c-erbB-2.

Design

c-erbB-2 expression was measured in canine mammary tumor-derived cell lines and in mammary tumor tissues from clinical cases. Clinical samples were examined histologically to determine whether they were benign or malignant and, if malignant, whether they had evidence of local invasion or regional metastasis. Canine fibroblast cultures and normal canine mammary epithelial tissues were used as reference standards for cell lines and mammary tumors, respectively.

Sample Populations

28 canine mammary tumor tissue samples obtained surgically from clinical cases and samples from 7 canine mammary tumor cell lines derived from primary canine mammary tumors.

Procedure

c-erbB-2 mRNA levels were determined by means of hybridization of total polysomal RNA with a 32P-labeled human c-erbB-2 probe on dot blots, and results were quantified by means of scanning densitometry. Overexpression of c-erbB-2 was defined as an autoradiographic density ≥ 2 times the density of reference samples on the same blot.

Results

Overexpression of c-erbB-2 was detected in 17 of 23 malignant tumors, 0 of 5 benign tumors, and 2 of 7 mammary tumor cell lines. c-erbB-2 overexpression was correlated with a histopathologic diagnosis of malignancy (P= 0.005) but not with the presence of local invasion or regional metastatic disease (P = 0.621).

Conclusions

Results suggest that overexpression of c-erbB-2 occurs prior to the development of metastatic disease in canine mammary tumors and plays a role in the development of malignancy. (Am J Vet Res 1996; 57:693–696)
Morphometric evaluation of immunoglobulin A-containing and immunoglobulin G-containing cells and T cells in duodenal mucosa from healthy dogs and from dogs with inflammatory bowel disease or nonspecific gastroenteritis
Authors: Jergens Albert E. , Moore Frances M. , Kaiser Mark S. , Haynes Joseph S. , Kinyon Joann M.
Published: January 2024

Objective

To investigate the distribution of IgA- and IgG-containing cells and T cells in the villi of duodenal mucosa from healthy dogs and from dogs with inflammatory bowel disease (IBD) or gastroenteritis.

Design

Case-control study.

Animals

28 dogs, grouped according to clinical and histologic criteria: 11 dogs with IBD, 8 dogs with nonspecific gastroenteritis, and 9 healthy dogs.

Procedure

Endoscopic biopsy specimens of duodenal mucosa from each dog were stained specifically for IgA and IgG heavy chains and pan T-cell (CD3) antigen, using immunoperoxidase techniques. Morphometric analysis, performed via an image-analysis system, was used to count IgA- and IgG-containing cells and T cells within paired contiguous villi from each dog.

Results

T cells were the predominant immune cell type in all groups of dogs. Significant differences in the villus distribution of IgA- and IgG-containing cells and T cells were not observed. Healthy dogs had significantly higher T-cell counts than had dogs with IBD or gastroenteritis. Dogs with nonspecific gastroenteritis had a significantly higher concentration of IgA-containing cells than the other groups of dogs had. Significant group differences for IgG-containing cells also were evident, with dogs with IBD having the lowest cell counts.

Conclusions and Clinical Relevance

High concentrations of IgA- and IgG-containing cells and T cells in the villus lamina propria cannot be reliably used to distinguish IBD from other intestinal disorders in dogs. Evaluation of T cells may be the most discriminatory method for differentiating dogs with IBD from clinically normal dogs via examination of intestinal biopsy specimens. (Am J Vet Res 1996; 57:697–704)
Effects of a combination of detomidine and butorphanol on respiratory function in horses with or without chronic obstructive pulmonary disease
Authors: Lavoie J. P. , Phan S. T. , Blais D.
Published: January 2024

Objective

To evaluate the effects of detomidine and butorphanol in combination on respiratory function in horses and to determine whether these effects are more severe in horses with pre-existing respiratory dysfunction.

Design

Pulmonary function testing and arterial blood gas analyses were performed before and after administration of a combination of detomidine (10 μg/kg of body weight, IV) and butorphanol (20 μg/kg, IV).

Animals

5 horses with chronic obstructive pulmonary disease and 5 horses free of respiratory disease (controls).

Procedures

Flow rates were obtained from a pneumotachograph attached to a face mask, and esophageal pressure was measured with a catheter placed in the distal third of the esophagus. Respiratory rate, tidal volume (VT), minute ventilation (VE), maximal change in transpulmonary pressure, pulmonary resistance, and dynamic compliance were calculated by use of a pulmonary function computer. Arterial blood was collected from the transverse facial artery, and blood gas partial pressures were measured with an automated blood gas analyzer.

Results

The combination of detomidine and butorphanol caused significant changes with time in respiratory rate, VT, VE, Paco2, and Paco2. Changes with time in VT, VE, and maximal change in transpulmonary pressure were significantly different between groups.

Conclusion

The combination of detomidine and butorphanol affects respiratory function in horses, and the observed changes are affected by the presence of preexisting respiratory dysfunction.

Clinical Relevance

Changes in respiratory function after administration of a combination of detomidine and butorphanol are not necessarily more severe in horses with pre-existing respiratory dysfunction. (Am J Vet Res 1996; 57:705–709)
Comparison of polymerase chain reaction and microbiological culture for detection of salmonellae in equine feces and environmental samples
Authors: Cohen Noah D. , Martin L. James , Simpson R. Bruce , Wallis Deeann E. , Neibergs Holly L.
Published: January 2024

Objective

To compare the sensitivity of polymerase chain reaction (PCR) with microbiological culture for detecting salmonellae in equine fecal samples and equine environmental swab specimens.

Design

Samples and specimens were tested by PCR and microbiological culture.

Sample Population

A fecal sample from each of 152 horses admitted consecutively to the clinic for evaluation by the outpatient service, 282 fecal samples from 110 hospitalized horses that had been submitted to the clinical microbiology laboratory, and 313 environmental swab specimens were examined.

Procedure

Each sample and specimen in the study was tested, using PCR and microbiological culture. Results of PCR and culture were compared.

Results

Significantly (P < 0.001) more fecal samples were positive by PCR than by microbiological culture. 26 of 152 (17.1%) fecal samples collected from horses admitted by the outpatient service were positive by PCR and none was positive by culture. 71 of 110 hospitalized horses were identified as positive by PCR, compared with 11 horses identified as positive by culture. All culture-positive horses were positive by PCR. Of the 11 culture-positive horses, 10 (90.9%) were identified as PCR positive after testing of the first sample submitted, compared with 7 (63.6%) by culture. All PCR-positive horses were detected after a total of 3 samples/horse were submitted, whereas as many as 5 samples/horse was required to identify all culture-positive horses. 8 of 313 environmental specimens were positive by PCR, and none was positive by culture.

Conclusion

The PCR method reported here was more sensitive, more rapid, and required submission of fewer samples or specimens than did microbiological culture for detecting salmonellae. (Am J Vet Res 1996;57:780–786)
Characterization of anatomic communications between the femoropatellar joint and lateral and medial femorotibial joints in cattle, using intra-articular latex, positive contrast arthrography, and fluoroscopy
Authors: Desrochers André , St.-Jean Guy , Cash Walter C. , Hoskinson James J. , DeBowes Richard M.
Published: January 2024

Objective

To evaluate the frequency of communication between the lateral and medial femorotibial joints and the femoropatellar joint in cattle.

Design

1 of 3 injection sites was randomly assigned to each ox.

Animais

102 limbs were obtained from 55 fresh bovine cadavers presented for necropsy with problems unrelated to the stifle.

Procedure

The joints were injected with a mixture of latex and barium sulfate. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and positive-contrast arthrography.

Results

Communication between the 3 joints was present in 58 (56.9%) limbs. The femoropatellar and the medial femorotibial joints always communicated. Thirteen of 38 (34.2%) specimens injected in the lateral femorotibial joint did not communicate with the 2 other joints. The femoropatellar joint communicated with the lateral and medial femorotibial joints on the distal abaxial aspect of the trochlear ridge.

Conclusion

Individual anatomic variation of the stifle in cattle should be considered when diagnostic or treatment protocols are established.

Clinical Relevance

The lateral femorotibial joint should be treated separately because it does not consistently communicate with the femoropatellar or medial femorotibial joint. (Am J Vet Res 1996;57:798–802)
Specific immune responses of dairy cattle after primary inoculation with recombinant bovine interferon-γ as an adjuvant when vaccinating against mastitis
Authors: Pighetti Gina M. , Sordillo Lorraine M.
Published: January 2024

Objective

To examine whether specific immunity in the mammary gland and blood of dairy cattle was enhanced after primary innoculation with a test antigen keyhole limpet hemocyanin (KLH) and recombinant bovine interferon-γ (rBolFN-γ) as an adjuvant.

Design

Holstein dairy cows received IM injections of KLH in conjunction with saline solution (n = 4), Freund's incomplete adjuvant (FIA; n = 4), or rBolFN-γ (n = 3). Milk and blood samples were collected during a 1-month period and analyzed for KLH antibody content. Isolated blood mononuclear cells were examined for their ability to proliferate and produce interleukin 2 (IL-2) after mitogen and/or KLH stimulation in vitro. The phenotype of isolated blood mononuclear cells also was characterized through flow cytometric analysis.

Results

The adjuvant rBolFN-γ induced serum KLH antibody titers similar to those induced by administration of FIA. However, FIA induced significantly more KLH antibodies in milk. Administration of rBolFN-γ enhanced T-lymphocyte activity, as indicated by the greater expression of high-affinity IL-2 receptors and the increased response to the mitogens concanavalin A, phytohemagglutinin, and IL-2, compared with FIA or saline treatment. Lymphocyte and monocyte movement from the blood also was altered after rBolFN-γ treatment, which can have a profound influence on secondary immune responses, such as antibody production.

Conclusions

rBolFN-γ may safely enhance specific immunity in the bovine mammary gland and may be an effective adjuvant in mastitis immunization protocols. (Am J Vet Res 1996;57:819–824)
Influence of vitamin D3 infusion and dietary calcium on secretion of interleukin 1, interleukin 6, and tumor necrosis factor in mice infected with Mycobacterium paratuberculosis
Authors: Stabel J. R. , Goff J. P.
Published: January 2024

Objective

To study the effects of 1,25(OH)2D3 and calcium (Ca) on splenocyte cytokine secretion during Mycobacterium paratuberculosis infection.

Design

Mice were assigned to the following treatments: 1—noninfected, 2—infected, 3—noninfected/1,25-(OH)2D3, 4—infected/1,25(OH)2D3, and 5—infected/low-Ca diet (0.15%).

Animals

Male beige mice averaging 6 weeks of age and 20 g in body weight.

Procedure

After acclimation to their diets, mice in treatments 2, 4, and 5 were inoculated IV with 108 colony-forming units of M paratuberculosis. At 1, 6, and 12 months after infection, mice in treatment groups 3 and 4 had miniosmotic pumps implanted subcutaneously that delivered 13 ng of 1,25(OH)2D3/day for 14 days. Treatment 5 was included as a control for comparison with treatment 4 because low dietary Ca should increase endogenous 1,25(OH)2D3 values. Splenocytes were isolated from mice at 1, 6, and 12 months and stimulated in vitro with medium alone (nonstimulated), lipopolysaccharide (LPS), concanavalin A, and M paratuberculosis whole-cell sonicate (MpS).

Results

Production of interleukin 6 after stimulation with LPS, concanavalin A, or MpS was higher (P < 0.05) for splenocytes isolated from mice fed the low-Ca diet, compared with control infected mice 1 and 6 months after infection. Interleukin 1 and tumor necrosis factor activities were increased (P < 0.05) in splenocytes cultured with LPS and MpS after isolation from mice of the low-Ca group. Mice infused with 1,25(OH)2D3 had higher (P < 0.05) interleukin 1 secretion after stimulation of splenocytes with LPS and higher (P< 0.05) tumor necrosis factor production after incubation with MpS.

Conclusion

1,25(OH)2D3 and low dietary Ca increase cytokine secretion in mice infected with M paratuberculosis. (Am J Vet Res 1996;57:825–829)
Use of adverse conditions to stimulate a cellular stress response by equine articular chondrocytes
Authors: Benton Hilary P. , Cheng Te-Chih , MacDonald Melinda H.
Published: January 2024

Objective

To determine the response of equine articular cartilage cells to heat and calcium stresses.

Design

Analysis of newly synthesized, [35S]methionine-labeled proteins after treatment of isolated primary equine chondrocytes.

Procedure

Primary cultures of equine articular chondrocytes were incubated at temperatures ranging from 37 to 42 C for heat stress experiments or incubated in the presence or absence of the intracellular calcium pump inhibitor, thapsigargin, for calcium stress experiments. Patterns of new protein synthesis were determined by incubating with [35S]methionine followed by separation of proteins by use of one- or two-dimensional gel electrophoresis and visualization of labeled proteins by use of fluorography.

Results

Equine chondrocytes cultured at temperature of 42 C had increased synthesis of specific proteins, compared with the profile of protein synthesis in control chondrocytes cultured at 37 C. These changes were characteristic of the heat shock stress response described in a number of other mammalian cell-types. Equine chondrocytes cultured in the presence of thapsigargin also had increased synthesis of specific proteins. Two-dimensional gel electrophoresis of these newly synthesized proteins revealed the changes to be consistent with the induction of the glucose-regulated protein family of stress proteins.

Conclusions

Changes in the pattern of new protein synthesis can be induced in differentiated equine articular chondrocytes by heat shock or calcium stress. These responses are characteristic of a widely described mammalian stress response that has been postulated to be involved in cellular protective mechanisms. The ability of equine chondrocytes to mount a robust stress response may be important in the processes of tissue damage and recovery in articular joints of horses. (Am J Vet Res 1996;57:860–865)
Parasympathetic component of 5-hydroxytryptamine-induced pulmonary dysfunctions in healthy calves
Authors: Linden Annick S. , Desmecht Daniel J.-M. , Amory Hélène , Lekeux Pierre M.
Published: January 2024

Objective

To determine whether a cholinergic mechanism interferes with the pulmonary response to 5-hydroxytryptamme (5-HT) in the bovine species.

Design

The protocols differed with regard to the type of pretreatment calves were given 10 minutes before administration of 5-HT (0.05 mg/kg of body weight/min, over 2 minutes). Pretreatment consisted of saline, atropine, or hexamethonium solution given IV.

Animals

6 healthy unsedated Friesian calves.

Procedure

Pulmonary function values were obtained before, during, and after 5-HT infusions.

Results

After saline pretreatment, response to 5-HT consisted of immediate and brief apnea, bradycardia, and hypotension, followed by sustained tachypnea, tachycardia, pulmonary hypertension, and hypocapnic hypoxemia. Lung dynamic compliance (CLdyn) decreased to 19% of its baseline value, and total pulmonary resistance (Rl) increased to 235%. Hexamethonium pretreatment resulted in a similar pattern of response except for the immediate and brief 5-HT-induced triad of apnea, bradycardia, and hypotension, which was suppressed. After atropine pretreatment, immediate and brief 5-HT-induced apnea-bradycardia-hypotension triad and sustained hypoxemia were abolished. In contrast, sustained tachypnea, tachycardia, pulmonary hypertension, and hypocapnia were maintained. Changes of CLdyn (59%) and Rl (138%) were significantly attenuated.

Conclusions

The initial and short-lasting response to 5-HT (ie, the apnea-bradycardia-hypotension triad) is mediated through a reflex central cholinergic pathway. The 5-HT-induced changes in Cldyn and Rl are consistent with development of diffuse bronchoconstriction. Attenuation of these changes by atropine suggests that this bronchoconstrictor response to 5-HT is partly mediated through a cholinergic postganglionic pathway. (Am J Vet Res 1996;57:896–901)
Effect of milking frequency on milk somatic cell count characteristics and mammary secretory cell damage in cows
Authors: Stelwagen Kerst , Lacy-Hulbert S. Jane
Published: January 2024

Objectives

To examine whether once daily milking (ODM) increases somatic cell count (SCC) and causes changes in the proportion of macrophages, lymphocytes, or neutrophils in milk, and to examine whether ODM causes mammary secretory cell damage.

Design

During 3 successive periods, cows were milked twice daily (days 1 through 4), once daily (days 5 through 10), and twice daily (days 11 through 14); thus, each cow served as its own control. Milk samples were collected during each milking for SCC, bovine serum albumin (BSA; except days 1 and 14), and N-acetyl-β-D-glucosaminidase (NAGase) activity analyses. Differential cell counts were determined on days 2 (period 1), 5 and 8 (period 2), and 11 (period 3) in morning milk samples.

Animals

8 multiparous Jersey cows.

Procedures

Cell counter (SCC), staining and counting (differential SCC), ELISA (BSA), and enzyme activity (NAGase).

Results

Once daily milking increased SCC (total and concentration), percentage of neutrophils, and BSA (content and total mass); during subsequent twice daily milking, SCC decreased, but BSA content and percentage of neutophils remained increased. Activity of NAGase was not affected by ODM.

Conclusions

ODM increases SCC, but this is not associated with damage to mammary secretory cells. The ODM-related sustained increase in BSA content coincided with an increase in neutrophil numbers, suggesting a causal relation. (Am J Vet Res 1996;57:902–905)
Laparoscopic anatomy of the abdomen in dorsally recumbent horses
Authors: Galuppo Larry D. , Snyder Jack R. , Pascoe John R. , Stover Susan M. , Morgan Richard
Published: January 2024

Objectives

To provide an accurate and detailed description of the laparoscopic anatomy of the abdomen of horses positioned in dorsal recumbency and to compare those observations with laparoscopic anatomy of standing horses. The effects of laparoscopy and positional changes on arterial blood pressure and blood gas values also were investigated.

Design

Descriptive anatomic study.

Sample Population

Laparoscopy was performed on 6 horses (2 mares, 2 geldings, and 2 stallions) to record the normal laparoscopic anatomy of the abdomen in dorsal recumbency.

Procedure

Feed was withheld from all horses for 36 hours. Horses, under general anesthesia, were examined in horizontal and inclined positions (head-up and head-down). Intermittent positive-pressure ventilation was used, arterial blood pressure was continuously monitored, and samples for arterial blood gas measurements were taken at intervals.

Results

The main structures of diagnostic relevance observed in the caudal region of the abdomen were the urinary bladder, mesorchium and ductus deferens (left and right), left and right vaginal rings, insertion of the pre-pubic tendon, random segments of jejunum and descending colon, pelvic flexure of the ascending colon, body of the cecum, and cecocolic fold. The main structures observed in the cranial region of the abdomen were ventral surface of the diaphragm, falciform ligament and round ligaments of the liver, ventral portion of the left lateral, left medial, quadrate, and right lateral lobes of the liver, spleen, right and left ventral colons, sternal flexure of the ascending colon, apex of the cecum, and stomach.

Conclusions

Alterations in cardiovascular and respiratory function in response to pneumoperitoneum and various positional changes indicated the need for continuous and throrough anesthetic monitoring and support. Comparison of anatomic observations made in dorsally recumbent, inclined horses with those reported for standing horses should enable practitioners to make patient positioning decisions that best suit access to specific visceral structures. Development of special instrumentation for manipulation of the viscera in horses, particularly the intestinal tract, would increase the diagnostic and therapeutic capabilities of laparoscopy during dorsal recumbency. (Am J Vet Res 1996;57:923–931)
Reproducibility of the blood lactate-running speed curve in horses under field conditions
Authors: Guhl A. , Lindner A. , von Wittke P.
Published: January 2024

Objective

To examine the reproducibility of blood lactate-running speed curve parameters derived by a curve-fit equation and by linear interpolation from the results of 4-speed tests of sport horses under field conditions.

Design

Thoroughbreds completed 10 test pairs with 3 to 11 days between test and retest.

Animals

7 Thoroughbreds.

Procedure

The 4-speed test consisted of 4 runs over a distance of 2,110 m. Exercise intensity was increased by 1 m/s for each run. Blood lactate concentration measured after each run was plotted against running speed to determine the blood lactate-running speed relation. By means of the blood lactate-running speed relation, velocity inducing 2, 2.5, 3, 3.5, or 4 mM blood lactate concentration was calculated by a curve-fit equation and by linear interpolation.

Results

The test-retest correlation coefficient of velocity inducing 2, 2.5, 3, 3.5, and 4 mM blood lactate concentration determined by curve-fit equation was 0.67, 0.78, 0.84, 0.86, and 0.86, respectively, and by linear interpolation was 0.42, 0.58, 0.77, 0.87, and 0.78, respectively. But the test-retest regression was equal to the line of identity only for velocity inducing 3.5 and 4 mM blood lactate concentration.

Conclusions

The reproducibility of velocity inducing 3.5 and 4 mM blood lactate concentration was sufficient to be used to compare horses and evaluate conditioning effects. This holds for both methods of calculation of the parameters derived from the blood lactate-running speed relation. (Am J Vet Res 1996;57:1059–1062)
Geometric variables and bone mineral density as potential predictors for mechanical properties of the radius of Greyhounds
Authors: Muir Peter , Markel Mark D.
Published: January 2024

Objective

To determine cross-sectional geometry and bone mineral density of the Greyhound radius and correlate these values with torsional failure load and torsional stiffness in an ex vivo model.

Design

3 regions, proximal, middle, and distal portions of the diaphysis, were studied. 5 levels of cross section were evaluated geometrically within each region.

Specimens

10 paired radiuses from skeletally mature Greyhounds.

Procedure

Cortical area and area moment of inertia were measured from plain radiographic views and from digitized computed tomographic images. Bone mineral density was measured, using dual-energy x-ray absorptiometry. Torsional stiffness and torsional failure load were then determined mechanically.

Results

Minimum area moment of inertia and area moment of inertia estimated from plain radiographic views were significantly different in different regions of interest (P < 0.05). Significant bivariate correlations (P < 0.05) between torsional mechanical parameters and bone properties of the radius were identified for the distal portion of the diaphysis in particular. When independent variables for the distal portion were analyzed, estimate of area moment of inertia was entered into the model for torsional failure load as a predictor and minimum area moment of inertia was entered into the model for torsional stiffness as a predictor. Bone mineral density of the distal portion of the diaphysis was not a significant predictor.

Conclusion

If accurate noninvasive predictors of bone failure load can be identified, further study of fracture risk should be possible. (Am J Vet Res 1996;57:1094–1097)
Histomorphometric and angiographic analysis of the humerus in pigeons
Authors: West P. G. , Rowland G. R. , Budsberg S. C. , Aron D. N.
Published: January 2024

Objective

To identify the vascular supply and resorption/formation activity of the humerus of pigeons.

Design

Pigeons were injected with the fluorochrome label oxytetracycline and, 5 days later, with the label calcein. 5 days after administration of the second fluorochrome, a wing from each bird was infused with a microparticle barium solution immediately after euthanasia and the chosen humerus was prepared for angiography while the opposite was prepared for histomorphometry.

Animals

17 nine-month-old pigeons, consisting of 9 male and 8 female birds.

Procedure

At euthanasia, 1 wing was chosen for infusion and the barium solution was injected through a catheter in the brachiocephalic artery. Both humeruses were harvested. The infused humerus was decalcified, radiographed, and sectioned for H&E staining. The opposite humerus was sectioned and measured by use of a morphometric analyzing system to determine cross-sectional area, endosteal and periosteal perimeter, and percentage of perimeter containing a single and/or double label.

Results

All pigeons had an intramedullary arterial supply. The bones had a quiescent appearance histologically, consisting principally of lamellar bone with few osteospecialized cells, resorption surfaces, or osteons. Less than 10% of either the periosteal or endosteal surface acquired a fluorochrome label.

Conclusions

The intramedullary vascular supply of the humerus is similar in structure to the vascular supply to mammalian bones. The humerus is, however, a quiescent bone in the sexually mature pigeon, with little remodeling activity present.

Clinical Relevance

The intramedullary blood supply may have an important role in the healing of humeral fractures in avian species. (Am J Vet Res 1996;57:982–986)