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Biomedical subjects

Laura D Dvorak

Publications and source records attributed to Laura D Dvorak.

5 recordsLinked to original sources

Radiographic and electrocardiographic evaluation of cardiac morphology and function in captive cheetahs (Acinonyx jubatus).

In a prospective study, eight (four males and four females) healthy, adult captive cheetahs (Acinonyx jubatus) were immobilized with a combination of tiletamine-zolazepam (4 mg/kg, i.m.), administered with a remote drug delivery system, to define normal cardiac morphology and function. Standard lateral and ventrodorsal (VD) radiographs were then taken to measure heart and thorax using a metric and vertebral scale system. Standard six-lead electrocardiograms were obtained with the animals in right lateral recumbency under isoflurane anesthesia. Mean chest depth and width was 18.7 +/- 1.3 cm and 13.0 +/- 0.6 cm, respectively. The mean lateral cardiac short axis (X) was 9.1 +/- 0.6 cm. the mean cardiac long axis (Y) was 13.6 +/- 0.7 cm, and the mean lateral heart sum (X + Y) was 22.6 +/- 1.2 cm. In the VD projection, mean cardiac short axis (V) was 10.1 +/- 0.7 cm, mean cardiac long axis (W) was 14.9 +/- 1.2 cm, and the heart sum (V + W) was 24.9 +/- 1.8 cm. The vertebral heart size was 8.2 +/- 0.9. All cheetahs had sinus rhythm, and no arrhythmias were noted. Mean heart rate was 126 +/- 15 beats/min, and the mean electrical axis was 82 + 5 degrees. P waves were always positive on lead II and had a width of 0.04 +/- 0.01 sec and a height between 0.1 and 0.3 mV. PR intervals were 0.11 +/- 0.01 sec. The height of the QRS complex was 1.25 +/- 0.24 mV and the width 0.06 +/- 0.01 sec. The ST segment was 0.04 sec, and the T wave (height: 0.25 +/- 0.05 mV) was positive in all cheetahs examined. Although these cardiac and thoracic measurements were larger than those of domestic cats (Felis catus), ratios of cardiac parameters were similar in both species. Electrocardiographic findings were similar to those reported from domestic cats.

Acinonyx↗

Effects of carprofen and dexamethasone on canine chondrocytes in a three-dimensional culture model of osteoarthritis.

OBJECTIVE: To determine effects of carprofen and dexamethasone on chondrocytes in a culture model of osteoarthritis (OA). SAMPLE POPULATION: Chondrocytes isolated from articular cartilage of the humeral head of 5 adult dogs. PROCEDURE: Chondrocytes were harvested, cultured and subcultured in monolayer, and then cultured in a 3-dimensional (3-D) medium. Cells from each dog were distributed into 6 groups with differing content of liquid medium for each 3-D construct (agarose [AG], AG plus interleukin [IL]-1beta, AG plus carprofen [4 microg/mL], AG plus dexamethasone [1 mg/mL], AG plus IL-1beta [20 ng/mL] plus carprofen [4 microg/mL], and AG plus IL-1beta (20 ng/mL) plus dexamethasone (1 mg/mL). On days 3, 6, 12, and 20 of culture, samples from all groups were collected. Liquid media were assayed for glycosaminoglycan, prostaglandin (PG)E2, matrix metalloprotease (MMP)-3, and MMP-13 concentrations. All 3-D constructs were evaluated for viability, cell morphology, proteoglycan staining, and collagen type-II concentration. Total glycosaminoglycan content in each 3-D construct was quantitated by spectrophotometric assay. RESULTS: Addition of IL-1beta caused a significant loss of cell viability and matrix production. Addition of carprofen or dexamethasone caused significant decreases in PGE2 in the liquid media, and each was minimally effective in protecting chondrocytes against negative effects of IL-1beta. CONCLUSIONS AND CLINICAL RELEVANCE: Human recombinant IL-1beta resulted in loss of cell viability, alterations in extracellular matrix components, and production of PG and MMP Carprofen and dexamethasone had little effect on cell and matrix variables but did decrease PGE2 concentrations and primarily affected the inflammatory pathway of osteoarthritis.

Animals↗

Major glossectomy in dogs: a case series and proposed classification system.

Major resections of the tongue have not been commonly performed in animals because of concerns about the unfavorable postoperative effects of diminished lingual function. Five dogs were retrospectively reviewed to determine prehensile function and quality of life after glossectomies. Examinations were performed 1 week to 8 years after glossectomy, and owner interviews were conducted 10 months to 8 years after the surgery. All five dogs had acceptable and functional outcomes. Based on these five cases, glossectomy was well tolerated by dogs and may be a viable treatment option for aggressive tongue tumors and other conditions that render the tongue unsalvageable.

Animals↗