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Biomedical subjects

B T Bennett

Publications and source records attributed to B T Bennett.

At least 19 recordsLinked to original sources
PubMed1993

A comparison of euthanasia methods in rats, using carbon dioxide in prefilled and fixed flow rate filled chambers.

The two methods (prefilled and fixed flow rate filled chambers) recommended in the 1993 AVMA Euthanasia Panel report for using carbon dioxide to euthanatize rats were evaluated in terms of their effect on behavior and selected blood gas values. Responses were videotaped during exposure to > or = 90% carbon dioxide in a prefilled chamber or a gradually filled chamber, using a fixed flow rate of 20% chamber volume/min. Arterial blood samples were taken to determine partial pressure of oxygen, partial pressure of carbon dioxide, pH, and oxygen saturation prior to entering the chamber and at time points determined by rats' responses to carbon dioxide. Rats showed similar reactions when exposed to carbon dioxide by either method. Significant differences in mean time for each response to occur were seen between euthanasia methods. Maintaining a near atmospheric oxygen chamber concentration by using a 75% CO2: 20% O2: 5% N2 gas mixture to gradually fill the chamber did not change rats' reactions upon exposure. Significant differences were found between pre-exposure values and values from samples obtained when rats became immobile after entering the prefilled chamber. Partial pressure of carbon dioxide significantly increased, and pH and percent oxygen saturation significantly decreased from pre-exposure values in all samples obtained after rats entered the gradually filled chamber. Partial pressure of oxygen in these rats was greater than or equal to pre-exposure levels in all samples. Rats appeared sedated because of the anesthetic effects of carbon dioxide when immobility was observed. Distress was not observed in the rats when either method of euthanasia was used.

Animals↗
PubMed1991

Disarming canine teeth of nonhuman primates using the submucosal vital root retention technique.

Removing or reducing the size of canine teeth of baboons and macaques has become an accepted practice to minimize the potential for injury to laboratory animal care personnel. A submucosal vital root retention procedure was adapted from the technique of root banking human teeth. In this technique, the crown of a tooth is amputated below the level of the alveolar bone crest, and the exposed pulp covered by a mucoperiosteal gingival flap. Our aim was to disarm the canine teeth of baboons and macaques with a single surgical procedure that would preserve a vital tooth root buried in alveolar bone under normal mucosa. Our long-term objective was to develop a technique that would not require further clinical management during the life of the animal. This paper presents the surgical techniques used.

Animals↗
PubMed1991

Ultrasonic determination of fetal parameters in baboons (Papio anubis)

The use of nonhuman primates to study reproductive physiology, fetal development, and neonatal management often depends on the availability of pregnant and fetal animals of known gestational history. The purpose of this study was to establish and correlate normal fetal growth parameters with gestational age in olive baboons (Papio anubis). Normal cycling females were bred to proven males by using the degree of perineal swelling and vaginal cytology to determine onset of ovulation. The subjects were evaluated to determine pregnancy beginning 18 days postmating, using an Aloka-650 diagnostic ultrasound unit, equipped with a 7.5 mHz prostate probe and a 5 mHz transabdominal probe. Ten pregnant animals were then evaluated sonographically every 3 days through day 30 and weekly through day 135 (average gestation 184 days). Measurements included gestational sac, greatest-length, biparietal diameter, femur length, head circumference, and abdominal circumference. Using the means and standard deviations, growth curves were constructed, and the data used to develop predicted value charts for gestational age estimation. Using the predicted value charts established in our study, subsequent evaluation of pregnant baboons in our colony disclosed concordance with actual gestational age.

Animals↗
PubMed1991

Long term anesthesia using a continuous infusion of guaifenesin, ketamine and xylazine in cats.

Cats (Felis catus) were anesthetized with a solution containing guaifenesin, ketamine and xylazine (GKX) in 0.9% saline. Anesthesia was induced by intravenous (IV) injection and was maintained for 6 hours by IV infusion. Heart rate, respiratory rate and PvO2 did not change significantly during the 6 hour monitoring period and remained consistently within the published normal ranges for cats. Although the PvCO2 did not change significantly, many values were abnormal. Venous pH decreased to slightly below normal values. Lead II ECG tracings showed no abnormalities. Loss of response to pedal pinch and jaw tone indicates maintenance of a surgical plane of anesthesia and adequate muscle relaxation throughout the 6 hour anesthetic period. Cats exhibited voluntary motor movement and were in sternal recumbency in just over 2 hours and were showing no residual clinical effects of the anesthesia 16 hours later. Although a transient mild acidosis was observed, we conclude that GKX provides a safe, effective and easily administered anesthetic regime for cats for periods up to 6 hours.

Anesthesia, Intravenous↗
PubMed1986

An indwelling catheter for the collection of cat uterine fluids.

A catheter system is described which allows for repeated samplings of uterine fluids in an awake animal. At laparotomy, catheters were inserted surgically into the ovarian pole of each uterine horn. The catheter ports then were passed through the abdominal wall through a stab incision and tunneled subcutaneously to a midlumbar position on each flank. The common uterine body was ligated to form a closed compartment. Uterine fluids were collected by saline lavage. Approximately 80% of the saline injected into one port was collected from the contralateral port and the catheters functioned successfully in each animal for approximately 45 repeated samplings.

Animals↗
PubMed1985

An outbreak of Plasmodium inui malaria in a colony of diabetic rhesus monkeys.

Plasmodium inui malaria is an infrequently reported disease of Macaca mulatta. In this report a total of 21 of 48 monkeys in a closed colony of diabetic animals developed hematological evidence of P. inui infection with five showing overt clinical signs of the disease. Diagnosis was confirmed morphologically, serologically and by transmission studies. Since six of these animals were born in the colony, a means of transmission was sought and it was determined that multiple use of a syringe to administer intravenous anesthesia was the probable means of cross transmission.

Animals↗
PubMed1982

Malignant nephroblastoma in Macaca fascicularis.

A case of malignant nephroblastoma was identified in a 4.5-month-old female Macaca fascicularis. The age of onset, clinical history, gross and microscopic pathology, and the pulmonary metastasis were analogous to this condition as seen in man.

Animals↗