Biomedical subjects
Publications and source records attributed to J S Spano.
This report describes a malignant odontogenic neoplasm in a 7-year-old bull. The mass, involving the right mandible, was locally invasive and destructive. Histologically, it consisted of islands and cords of benign odontogenic epithelium, entrapped in a population of malignant mesenchymal cells. These morphological features are characteristic of ameloblastic fibrosarcoma in man, an odontogenic tumour not previously described in animals.
OBJECTIVE: To evaluate effects of treatment with a pulsed electromagnetic field (PEMF) on healing of open and sutured wounds, clinicopathologic variables, and CNS activity of dogs. ANIMALS: 12 adult female Beagles. PROCEDURE: Open and sutured wounds were created in the skin of the trunk of the dogs. Dogs were divided into 2 groups. One group received PEMF treatment and 1 group served as untreated (control) dogs. The PEMF-treated dogs received treatment twice a day starting the day before surgery and lasting through day 21 after surgery. Wounds were evaluated by use of tensiometry, planimetry, laser Doppler perfusion imaging, and histologic examination. Clinicopathologic variables and electroencephalographic tracings were also evaluated. RESULTS: Use of PEMF treatment resulted in significantly enhanced epithelialization of open wounds 10 and 15 days after surgery. Five days after surgery, wounds of control dogs had a negative value for wound contraction, whereas PEMF-treated wounds had a positive value. The PEMF treatment did not cause significant changes in short-term planimetric, perfusion, tensiometric, histologic, clinicopathologic, or electroencephalographic results. CONCLUSIONS: The PEMF treatment enhanced wound epithelialization in open cutaneous wounds and provided indications of early contraction without significant short-term changes in other variables.
Because caffeine is metabolized by the hepatic P-450 cytochrome oxidase system, clearance of caffeine is an excellent quantitative test of hepatic function in human beings. It is currently used in much the same way that creatinine clearance is used to assess renal function. Caffeine clearance was measured in lactating dairy cows initially to determine the suitability of caffeine clearance as an indicator of hepatic function in cattle. Pharmacokinetic variables of caffeine were studied in 6 adult lactating dairy cows after i.v. administration of a single dose of caffeine sodium benzoate (2 mg of caffeine/kg of body weight). Caffeine concentration was analyzed by use of an automated enzyme immunoassay. The lower limit of detection of the assay for caffeine in serum was 0.079 micrograms/ml. Serum caffeine concentration-time curves best fit an open two-compartment pharmacokinetic model. Harmonic mean elimination half-life was 3.8 (range, 2.6 to 6.9) hours, and total clearance was 0.118 (range, 0.090 to 0.197) L/kg/h. Milk caffeine concentration was similar to serum concentration 1.5 to 24 hours after caffeine administration. Adverse effects were not observed in cows given caffeine.
A beef cow was examined to find the cause of decreasing appetite of 2 weeks' duration. The cow was obese (body condition score, 8 of 9), and multiple fetuses were identified on palpation per rectum. Urinalysis revealed > 160 mg of ketones/dl. Abnormal serum biochemical data included high concentrations of bilirubin, creatinine, sodium, and chloride; low concentrations of total CO2 and calcium; and high activity of aspartate transaminase. Treatment included administration of dextrose solution, i.v.; propylene glycol, PO; and insulin, i.v. and SC. The cow's appetite improved gradually over 8 days of treatment. Concentration of ketone bodies in urine decreased to trace amounts by day 4. The cow was discharged on day 10 and gave birth to twins 4 days after discharge (duration of gestation, 279 days). The clinical history of this cow differed from the history of other cattle with ketosis, but mimicked pregnancy toxemia in ewes. Multiple fetuses have not been implicated as a predisposing factor in severe prepartum ketosis of cows.
The pharmacokinetic properties of intravenously administered caffeine were studied in 10 horses using a commercially available automated enzyme immunoassay. The harmonic mean for the distribution half-life was 5.2 min (range 1.4-18.7). The harmonic mean for the elimination half-life was 10.18 h (range 6.82-20.92). The harmonic mean of the volume of distribution was 0.32 L/kg (range 0.22-0.53). There was no correlation between the dose of caffeine/kg body weight and the elimination half-life (Spearman's coefficient of rank correlation = 0.19).
A commercially available automated enzyme-multiplied immunoassay technique (EMIT) was used to determine serum caffeine concentration after oral and IV administrations of caffeine at dosage of 5 mg/kg of body weight to 12 clinically normal dogs. Dogs were allotted to 2 groups of 6 dogs each; 1 group initially received caffeine orally and the other received caffeine IV. After 72 hours, caffeine administration was repeated in all dogs in the alternate manner. Serum samples were obtained at multiple intervals over 24 hours to determine distribution and elimination kinetics. Analysis of the drug concentration-time data indicated IV elimination half-life (t1/2) of 6.39 +/- 1.87 hours, volume of distribution at steady state of 685.3 +/- 132.2 ml/kg, total body clearance of 1.31 +/- 0.38 ml/min/kg, absorption t1/2 of 1.02 +/- 0.68 hour, oral elimination t1/2 of 6.53 +/- 2.72 hours, lag time after oral administration of 0.0614 +/- 0.0661 hour, highest measured concentration of 5.29 +/- 1.17 micrograms/ml, time to peak concentration of 2.74 +/- 1.30 hours, and bioavailability of 99.4 +/- 19.4%. Data from 6 dogs best fit a 1-compartment open model and those from 6 other dogs best fit a 2-compartment open model. On the basis of data from the 6 dogs that best fit a 2-compartment model, t1/2 of distribution was 0.58 +/- 0.72 hour. Data for oral administration best fit a single absorption phase and a single elimination phase. The increased availability and simplicity of the EMIT offers an opportunity to study the application of caffeine elimination for clinical evaluation of dogs with liver disease.(ABSTRACT TRUNCATED AT 250 WORDS)
We characterized the clinicopathologic manifestations of experimentally induced endotoxin-induced mastitis. Responses to hypertonic fluid therapy also were assessed. Eight cows received 1 mg of endotoxin by intramammary infusion in the left forequarter. Four hours after endotoxin administration, cows received 0.9% NaCl, 5 ml/kg of body weight (n = 4) or 7.5% NaCl, 5 ml/kg (n = 4) IV. Endotoxin-infused cows had expanded plasma volume, hyponatremia, transient hyperchloremia and hypophosphatemia, increased serum glucose concentration, and decreased serum activities of liver- and muscle-specific enzymes. Calculated plasma volume increased at 6 hours in cows receiving hypertonic NaCl, and at 12, 24, and 48 hours after endotoxin infusion in both groups. Concurrent observations of decreased serum protein concentration, erythrocyte count, and hematocrit supported observations of increased plasma volume. Relative plasma volume was greater in cows receiving hypertonic NaCl (124.3%) than in cows receiving isotonic NaCl (106.6%) at 6 hours after endotoxin infusion. Cattle receiving hypertonic NaCl had increased voluntary water intake after IV fluid administration. Increased water consumption was not accompanied by increased body weight, indicating probable occurrence of offsetting body water loss. Serum sodium concentration in cows receiving hypertonic NaCl was increased 2 hours after fluid administration, but the magnitude of the change was minimal (< 4 mmol/L) and transient, indicating rapid equilibration with either interstitial or intracellular spaces. Serum sodium concentration was decreased in cows receiving isotonic NaCl at 12, 24, and 48 hours after endotoxin administration, compared with concentration prior to endotoxin administration, indicating selective loss of sodium.
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Anesthesia was induced and maintained in 6 Suffolk wethers by continuous i.v. infusion of guaifenesin (50 mg/ml), ketamine (1 mg/ml), and xylazine (0.1 mg/ml) in 5% dextrose in water (triple drip) to assess the anesthetic and cardiopulmonary effects. All sheep were positioned in right lateral recumbency. Dosages of triple drip used for induction and maintenance of anesthesia were 1.2 +/- 0.02 ml/kg and 2.6 ml/kg/h, respectively. Lack of gross purposeful movement of sheep to electrical stimulation indicated that analgesia and muscular relaxation induced by triple trip were adequate for surgical procedures. Heart rates and arterial blood pressure remained unchanged from baseline values during a 1-hour period of anesthesia. Arterial blood pressures were measured indirectly, using an inflation cuff placed over the metatarsal artery at the heart level. Significant decrease in arterial partial pressure of O2 (PaO2), coupled with an increase in arterial partial pressure of CO2 (PaCO2), from baseline values was observed throughout the course of the study. Decrease in PaO2 was observed concomitantly with significant (P < 0.05) increase in respiration rate. Changes in arterial blood gas tensions observed in this study were attributed to respiratory depressant effect induced by anesthetic drugs and right-to-left shunting, perfusion/ventilation mismatch, or both caused by right lateral recumbency. Administration of 100% O2 via the endotracheal tube reduced the magnitude of the decrease in PaO2. All sheep recovered smoothly and stood within 96.3 +/- 48.9 minutes after termination of triple drip administration.
Severe renal oxalosis was diagnosed in 4 male and 1 female purebred Beefmaster calves from herds in southeastern and northwestern United States. Clinical signs included weakness, anorexia, lethargy, alopecia, dehydration, and diarrhea. Results of serum biochemical analysis for 2 calves were consistent with end-stage renal disease. Calves died 2 days to 6 weeks after birth. At necropsy, renal calyces were dilated and contained pale yellow granular calculi. Histologically, there was renal interstitial fibrosis, and cortical and medullary tubules were distended with calcium oxalate crystals. Oxalate crystals were also in the tracheal glands of 1 calf. Severe renal oxalosis in young purebred calves, on widely varied diets, with no known exposure to exogenous oxalates is suggestive of an inherited metabolic defect resulting in primary hyperoxaluria.
The effect of ticlopidine on platelet function, platelet number, mean platelet volume, antithrombin III activity, and fibrinogen was evaluated in 10 laboratory beagles. Ticlopidine (62 mg/kg) significantly inhibited ADP- and collagen-induced platelet aggregation within 2 days of the beginning of oral administration. Collagen-induced platelet 14C-serotonin release was not inhibited by day 9 of medication but was inhibited by day 20 in two of three beagles given medication for 32 days. Significant increases in mean platelet number were observed on days 2 and 5. The trend toward increased platelet number continued until day 16, at which time platelet number began to decrease toward baseline in three of three dogs treated for 32 days. Mean platelet volume (MPV) was significantly decreased compared to baseline on days 5 and 9. In three dogs treated for 32 days, the lowest MPV was observed on day 9 in two dogs and on day 12 in one dog. Significant changes were not observed in antithrombin III activity or fibrinogen with ticlopidine treatment.
Six healthy mature horses were orally administered a single dose of phenobarbital (26 mg/kg of body weight), then multiple doses (13 mg/kg) orally for 42 consecutive days. Seventeen venous blood samples were collected from each horse after the single dose study and again after the last dose on day 42. Plasma phenobarbital concentration was determined by use of a fluorescence assay validated for horses. Additional blood samples (n = 11) were collected on days 8 and 25 to determine peak and trough concentrations, as well as total body clearance. Phenobarbital disposition followed a one-compartment model. Mean kinetic variables after single and repeated orally administered doses (42 days) were: elimination half-life = 24.2 +/- 4.7 and 11.2 +/- 2.3 hours, volume of distribution = 0.960 +/- 0.060 and 0.914 +/- 0.119 L/kg, and clearance = 28.2 +/- 5.1 and 57.3 +/- 9.6 ml/h/kg, respectively. Results indicated that significant (P less than 0.05) difference in half-life and oral clearance existed between single and repeated dosing. The significant decrease in half-life after repeated dosing with phenobarbital may be indicative of enzyme induction. Significant difference was not observed between baseline serum enzyme concentration and concentration measured on day 42, except for gamma-glutamyltransferase activity, which was significantly increased on day 42 in 3 of the 6 horses. On the basis of increases in oral clearance observed over 42 days, dose adjustments may be required.(ABSTRACT TRUNCATED AT 250 WORDS)
Myelophthisic pancytopenia was diagnosed in a 10-year-old pony mare with a history of recurring colic and anemia. Physical findings were unremarkable, with the exception of pale mucous membranes. Hematologic analysis revealed nonregenerative pancytopenia. Testing for equine infectious anemia and antiglobulin (Coombs) yielded negative results. The mare was treated with antibiotics, boldenone undecylenate, and corticosteroids, but a regenerative bone marrow response was not seen. Postmortem examination revealed severe myelofibrosis and multiple sites of extramedullary hematopoiesis. Myelophthisic pancytopenia develops when a space-occupying lesion destroys sufficient bone marrow or disturbs marrow architecture, resulting in decreased production capacity. Pancytopenia in the pony of this report resulted from inadequate production of blood cellular components secondary to replacement of the bone marrow by myelofibrosis. Cause of the myelofibrosis was not identified.
The effect of in ovo bursectomy on hatchability, mortality rate, and antibody response to keyhole limpet hemocyanin (KLH) was studied in hypertensive and hypotensive lines of turkeys. Experiments were conducted to assess the optimal time to perform surgical in ovo bursectomy in turkey embryos for the lowest mortality rate. Factors such as the ease of operation, hatchability, and least deaths were considered. Surgical bursectomies at 25, 24, 23, and 22 day embryonation resulted in 75, 20, 0, and 10% hatchability, respectively. The surgical procedure performed at 25-day embryonation resulted in superior hatchability and ease of operation, and it was less traumatic as evidenced by fewer deaths. The hatchability of embryos injected with testosterone (TE) at 15 days incubation was 55%. Birds subjected to surgery or chemical treatment had increased mortality rates. Cyclophosphamide (CY) treatment at 1 and 2 days posthatch caused a significant increase in deaths over groups not treated with CY. Both primary and secondary KLH responses were significantly lower in bursectomized and TE-injected groups, than in shamoperated or nonoperated control groups.
The effects of surgical and chemical in ovo bursectomy on the histology of primary and secondary lymphoid organs were studied in hypertensive and hypotensive lines of turkeys. The effects of bursectomy were measured by determining the presence of lymphatic nodules and the presence of lymphocytes in secondary lymphoid organs: spleen, cecal tonsil, Meckel's diverticulum, and Peyer's patches; as well as in the thymus and bursa of Fabricius. No treatment effect on splenic nodule formation occurred, but a significantly lower lymphocyte density score was present in the surgically bursectomized group. Both nodule formation and lymphocyte density scores for the cecal tonsil and Peyer's patches were significantly reduced in the surgically bursectomized and testosterone-treated groups as compared with the control and sham groups. The most consistent depression in lymphatic scores in both the surgically and chemically bursectomized groups occurred in the Peyer's patches followed by cecal tonsils and Meckel's diverticulum. As expected, there were no differences in thymocyte density scores. There was no consistent effect on lymphatic scores due to blood pressure selection; however, the hypertensive line showed significantly lower scores than the hypotensive line in the bursa, cecal tonsils, and Peyer's patches. No differences between the sexes were noted in any organ.
Gentamicin sulfate-induced nephrotoxicosis was compared in 2 groups of horses fed different rations. Four horses were fed only alfalfa hay, and 4 other horses were fed only whole oats. Seven days after initiation of the diet, all horses were given gentamicin IV (5 mg/kg of body weight) every 12 hours for 22 days. Urinary gamma-glutamyl-transferase to urinary creatinine (UGGT:UCr) ratio was calculated daily, and serum concentration of gentamicin was measured at 1 and 12 hours after drug administration. Results indicated that horses fed oats had greater renal tubular damage than did horses fed alfalfa. Mean UGGT:UCr for horses fed alfalfa was 47.1 +/- 18.8 and was 100.0 +/- 19.0 for horses fed oats (P = 0.007). The UGGT:UCr in horses fed oats was greater than 100 for a total of 54 days; horses fed alfalfa had UGGT:UCr greater than 100 for only 7 days. Two horses not given gentamicin were fed only oats and 2 were fed only alfalfa. These horses had mean UGGT:UCr of 17.6 +/- 2.2 and 30.5 +/- 3.0, respectively. Mean peak and trough concentrations of gentamicin were statistically different for horses fed oats and those fed alfalfa (peak 23.16 +/- 1.87 and 14.07 +/- 1.79 micrograms/ml, respectively [P = 0.0001], and trough, 1.81 +/- 0.69 and 0.71 +/- 0.70 micrograms/ml, respectively [P = 0.0270]). Mean half-lives of gentamicin (estimated from peak and trough concentrations) for horses fed alfalfa (2.58 +/- 0.26 hours) and horses fed oats (2.88 +/- 0.27 hours) were not significantly different. Horses fed only oats had greater degree of gentamicin-induced nephrotoxicosis than did those fed only alfalfa.
To determine the drug dose required to inhibit platelet reactivity by at least 50%, 2 drug regimens were evaluated in heartworm-negative, heartworm-infected, and heartworm-infected dogs embolized with dead heartworms. Aspirin, or a combination of aspirin and dipyridamole, were administered to 2 groups of Beagles (n = 5 each) for 5 to 9 days; a third group of 5 Beagles served as nontreated controls. For heartworm-negative dogs, mean (+/- SD) aspirin dosage that inhibited collagen-induced platelet reactivity by at least 50% was 6 (+/- 2) mg/kg of body weight given once daily. The aspirin/diphridamole combination dosage was 1 mg of each drug/kg given every 12 hours. All dogs (n = 15) were implanted with 7 adult heartworms each and remedicated (or not treated) beginning at 21 days after heartworm implantation. In heartworm-infected dogs, mean aspirin dosage required to inhibit collagen-induced platelet reactivity greater than or equal to 50% was 10 (+/- 6) mg/kg. Mean dosage of aspirin/dipyridamole combination was 1.6 +/- (0.5) mg of each drug/kg given every 12 hours. When platelet reactivity in response to collagen was determined to be inhibited by at least 50% in all medicated dogs, each dog (n = 15) was embolized with 7 dead adult heartworms to mimic heartworm adulticidal treatment. Platelet reactivity was monitored for 21 days after treatment, and drug dose was adjusted to maintain platelet inhibition by at least 50%. In embolized dogs, mean aspirin dosage was 17 (+/- 14) mg/kg given once daily. Mean dosage of the aspirin/dipyridamole combination was 2.8 (+/- 1.3) mg of each drug/kg given every 12 hours. All dogs (n = 15) were euthanatized 21 days after heartworm embolization. Each lung lobe was evaluated for severity of lesions and presence of organized or fibrinous thrombi. Lesion severity in the aspirin- and aspirin/dipyridamole-treated dogs was not significantly different from that in control dogs.
Ticlopidine hydrochloride was evaluated for its effectiveness in inhibiting platelet aggregation and serotonin release in 5 laboratory Beagles before and after heartworm implantation with 7 adult Dirofilaria immitis, and after embolization with 7 dead heartworms to mimic what happens after heartworm adulticide treatment. Five other laboratory Beagles, similarly implanted and embolized with heartworms, were used as nonmedicated controls. During the heartworm-negative stage, the dosage of ticlopidine that inhibited adenosine diphosphate (ADP)-induced platelet aggregation in 5 dogs by at least 50% after 5 days of treatment was 62 mg/kg of body weight once a day. In the same dogs implanted with 7 adult heartworms 21 days previously, mean (+/- SD) ticlopidine dosage required to obtain similar results was 71 (+/- 13) mg/kg given once daily. During the 21 days after dead heartworms were implanted in heartworm-infected dogs, mean ticlopidine dosage was 108 (+/- 35) mg/kg (range, 62 to 150 mg/kg). Ticlopidine treatment was associated with increased platelet numbers in all 5 dogs during the heartworm-negative stage and in 4 of 5 dogs during the heartworm implantation and heartworm embolization stages. Mean platelet volume tended to decrease as platelet numbers increased. At necropsy, gross and histologic pulmonary lesions were less severe in ticlopidine-treated dogs than in nonmedicated control dogs.