Objective—To compare the effects of hydrochloric acid (HCl) and various concentrations of volatile fatty acids (VFAs) on tissue bioelectric properties of equine stomach nonglandular (NG) mucosa.
Sample Population—Gastric tissues obtained from 48 adult horses.
Procedures—NG gastric mucosa was studied by use of Ussing chambers. Short-circuit current (Isc) and potential difference (PD) were measured and electrical resistance (R) and conductance calculated for tissues after addition of HCl and VFAs (5, 10, 20, and 40mM) in normal Ringer's solution (NRS).
Results—Mucosa exposed to HCl in NRS (pH of 1.5 and, to a lesser extent, 4.0) had a significant decrease in Isc, PD, and R, whereas tissues exposed to acetic acid at a pH of < 4.0, propionic and butyric acids at a pH of ≤ 4.0, and valeric acid at a pH of ≤ 7.0 induced a concentration-dependent effect on reduction in these same values. Values for Isc returned to baseline (recovery of sodium transport) after addition of calcium carbonate in tissues exposed to all concentrations of VFAs except the higher concentrations of valeric acid at a pH of ≤ 4.0. Histologic examination revealed cell swelling in the mucosal layers below and adjacent to the stratum corneum in tissues exposed to HCl and VFAs at a pH of ≤ 4.0.
Conclusions and Clinical Relevance—The VFAs, especially acetic acid, in the presence of HCl at a pH of ≤ 4.0 appear to be important in the pathogenesis of NG mucosal ulcers in horses.
Objective—To determine the prevalence of lymphosarcoma and other tumors affecting the spinal cord of cats and to relate specific types of tumors with signalment, history, and clinical findings.
Design—Retrospective case series.
Animals—85 cats with tumors affecting the spinal cord.
Procedures—Medical records of cats with histologically confirmed primary or metastatic tumors of the spinal cord or tumors causing spinal cord disease by local extension from adjacent tissues examined between 1980 and 2005 were reviewed. Data on signalment; clinical history; results of neurologic examination, diagnostic imaging, and clinical pathologic evaluation; and location of tumor within the spinal cord were obtained from medical records and analyzed by use of logistic regression models.
Results—Lymphosarcoma was the most common tumor and affected the spinal cord in 33 (38.8%) cats, followed by osteosarcoma in 14 (16.5%) cats. Cats with lymphosarcoma were typically younger at initial examination, had a shorter duration of clinical signs, and had lesions in more regions of the CNS than did cats with other types of tumors. In 22 of 26 (84.6%) cats with lymphosarcoma, the tumor was also found in extraneural sites.
Conclusions and Clinical Relevance—Data for spinal cord tumors in this population of cats were analyzed by logistic regression analysis, which effectively distinguished cats with lymphosarcoma from cats with other types of tumors. Additional clinical information reported here will help to increase the index of suspicion or definitive antemortem diagnosis of spinal cord tumors of cats.