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Featured researches published by Kristina Kiefer.


Frontiers in Veterinary Science | 2016

Comparison of Mesenchymal Stem Cell Surface Markers from Bone Marrow Aspirates and Adipose Stromal Vascular Fraction Sites

Meghan O. Sullivan; Wanda J. Gordon-Evans; Lisa Page Fredericks; Kristina Kiefer; Michael G. Conzemius; Dominique J. Griffon

The objective of this study was to subjectively evaluate the harvest of two areas of adipose collection and three areas of bone marrow collection as potential sites for clinical harvest of adipose stromal vascular fraction (SVF) and bone marrow concentrate for clinical use by quantifying the amount of tissue harvested, subjective ease of harvest, the variation of each site, and determining the cell surface marker characteristics using commercially available antibodies. Bone marrow and adipose tissue samples were collected from 10 adult mixed breed dogs. Adipose tissue was collected from the caudal scapular region and falciform fat ligament. Bone marrow aspirates were collected from the ilium, humerus, and tibia. Tissues were weighed (adipose) or measured by volume (bone marrow), processed to isolate the SVF or bone marrow concentrate, and flow cytometry was performed to quantitate the percentage of cells that were CD90, CD44 positive, and CD45 negative. Sites and tissue types were compared using matched pairs t-test. Subjectively subcutaneous fat collection was the most difficult and large amounts of tissue dissection were necessary. Additionally the subcutaneous area yielded less than the goal amount of tissue. The bone marrow harvest ranged from 10 to 27.5 ml. Adipose tissue had the highest concentration of cells with CD90+, CD44+, and CD45− markers (P < 0.05), and bone marrow had the highest total number of these cells at harvest (P < 0.05). Variation was high for all sites, but the adipose collection yielded more consistent results. These results describe the relative cellular components in the SVF of adipose tissue and bone marrow as defined by the biomarkers chosen. Although bone marrow yielded higher absolute cell numbers on average, adipose tissue yielded more consistent results. Fat from the falciform ligament was easily obtained with less dissection and therefore created less perceived relative patient trauma.


Journal of The American Animal Hospital Association | 2010

Magnet ingestion in dogs: two cases.

Kristina Kiefer; Heidi Hottinger; Mary Ngo; Ron Ben-Amotz

Two dogs that had ingested foreign bodies were presented with vomiting. The foreign bodies appeared as metal and dense on abdominal radiographs. Abdominal exploratory identified intestinal perforation in one case and gastrointestinal tissue trapped between the two foreign bodies adhered to each other in the second case. The foreign bodies were identified as magnets in one case and magnets and other metallic foreign bodies in the second case. Both dogs had excellent outcomes following surgical intervention. These cases demonstrate the danger of tissue entrapment between the foreign bodies as a result of the magnetic attraction between two objects. Dogs that are presented with a history of or are suspect for ingesting multiple magnets or a magnet and metal foreign bodies should be treated with surgical intervention because of the risk of gastrointestinal perforation as a result of magnetic attraction between the foreign bodies.


Journal of The American Animal Hospital Association | 2015

Outcome and Prognostic Indicators in Cats Undergoing Splenectomy for Splenic Mast Cell Tumors

Kelly A. Kraus; Craig A. Clifford; Garrett J. Davis; Kristina Kiefer; Kenneth J. Drobatz

This was a multi-institutional retrospective study evaluating the outcome and clinical parameters associated with the postoperative prognosis of 36 cats with splenic mast cell tumors treated with splenectomy. Clinical parameters reviewed included signalment, clinical history, results of staging tests, surgical variables, administration of blood products, presence of metastasis, postoperative complications, administration of chemotherapy postoperatively, chemotherapy protocol, and response to chemotherapy. Overall median survival time was 390 days (range, 2-1737 days). Administration of a blood product (P < .0001), metastasis to a regional lymph node (P = .022), and evidence of either concurrent or historical neoplasia (P = .037) were negatively associated with survival. Response to chemotherapy (P = .0008) was associated with an improved median survival time. Larger-scale prospective studies evaluating different chemotherapy protocols are required to elucidate the discrepancy between lack of survival benefit with administration of chemotherapy and improvement in survival time with positive response to chemotherapy.


Journal of Veterinary Emergency and Critical Care | 2016

Autotransfusion in dogs using a 2‐syringe technique

Duane A. Robinson; Kristina Kiefer; Rachel Bassett; Jane E. Quandt

OBJECTIVE To describe the successful use of an autotransfusion technique utilizing 2 syringes in 4 dogs. CASE SERIES SUMMARY All 4 dogs in this series had a hemoabdomen and subsequent hypovolemic shock. During surgery blood was collected from the abdominal cavity by the surgeon and passed to an assistant. The blood was then transferred to a second syringe for direct IV administration. The blood was passed through an inline blood filter prior to reaching the patient. Given the transfusion volume and administration time frame, 3 cases were classified as a massive transfusion. All 4 dogs survived the transfusion, were discharged within 3 days of surgery/transfusion and no complications were noted. NEW OR UNIQUE INFORMATION PROVIDED This case series describes a relatively simple method of performing an autotransfuion in patients with hemoabdomen and hypovolemic shock.


Veterinary Record Open | 2015

Canine adipose-derived stromal cell viability following exposure to synovial fluid from osteoarthritic joints

Kristina Kiefer; Timothy D. O'Brien; Elizabeth Pluhar; Michael G. Conzemius

Introduction Stem cell therapy used in clinical application of osteoarthritis in veterinary medicine typically involves intra-articular injection of the cells, however the effect of an osteoarthritic environment on the fate of the cells has not been investigated. Aims and Objectives Assess the viability of adipose derived stromal cells following exposure to osteoarthritic joint fluid. Materials and Methods Adipose derived stromal cells (ASCs) were derived from falciform adipose tissue of five adult dogs, and osteoarthritic synovial fluid (SF) was obtained from ten patients undergoing surgical intervention on orthopedic diseases with secondary osteoarthritis. Normal synovial fluid was obtained from seven adult dogs from an unrelated study. ASCs were exposed to the following treatment conditions: culture medium, normal SF, osteoarthritic SF, or serial dilutions of 1:1 to 1:10 of osteoarthritic SF with media. Cells were then harvested and assessed for viability using trypan blue dye exclusion. Results There was no significant difference in the viability of cells in culture medium or normal SF. Significant differences were found between cells exposed to any concentration of osteoarthritic SF and normal SF and between cells exposed to undiluted osteoarthritic SF and all serial dilutions. Subsequent dilutions reduced cytotoxicity. Conclusions Osteoarthritic synovial fluid in this ex vivo experiment is cytotoxic to ASCs, when compared with normal synovial fluid. Current practice of direct injection of ASCs into osteoarthritic joints should be re-evaluated to determine if alternative means of administration may be more effective.


Veterinary and Comparative Orthopaedics and Traumatology | 2009

Ilio-femoral external fixator application for temporary stabilization of recurring caudal ventral hip joint luxation after total hip replacement

Ron Ben-Amotz; W. D. Liska; B. S. Beale; N. D. Doyle; Kristina Kiefer

An ilio-femoral external fixator was applied to a 13-year-old male, castrated mixed breed dog with a caudal ventral luxation that persistently luxated following both closed reduction and open reduction with a total hip replacement. The external fixator was placed in order to temporarily maintain reduction during soft tissue healing. Upon removal of the external fixator the dog underwent physical therapy. Reduction was maintained and the dog returned to normal function.


Veterinary Medicine | 2007

Salivary mucoceles in cats : A retrospective study of seven cases

Kristina Kiefer; Garrett J. Davis


Open Journal of Regenerative Medicine | 2014

The Influence of Culture Medium Type on Cellular Phenotype of Canine Adipose Derived Stem Cells

Kristina Kiefer; G. Elizabeth Pluhar; Michael G. Conzemius; Timothy D. O’Brien


Verbum Et Ecclesia | 2016

Does Adipose-derived Stromal Cell Adjuvant Therapy for Fragmented Medial Coronoid Process in Dogs Influence Outcome? A Pilot Project

Kristina Kiefer; Katja Lin; Noel Fitzpatrick; Elizabeth Pluhar; Michael G. Conzemius


Veterinary and Comparative Orthopaedics and Traumatology | 2018

Double-Blinded, Placebo Controlled Study Evaluating the Safety and Efficacy of Intravenous Allogeneic Adipose Stromal Cell Therapy for Canine Osteoarthritis

Kristina Kiefer; Phillip Allen; Michael G. Conzemius

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Craig A. Clifford

University of Pennsylvania

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Dominique J. Griffon

Western University of Health Sciences

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