Measuring cochlear blood flow by laser Doppler spectroscopy.

Cochlear blood flow (CBF) was studied with a commercially available laser Doppler system in 20 guinea pigs. The cochlea was exposed to permit placement of the laser Doppler probe over the intact lateral wall of the basal turn. Ketamine and xylazine were used for anesthesia, and blood pressure was monitored from the femoral artery. In some cases, skin blood flow was monitored with a second laser Doppler system, and cardiac output was monitored with an ultrasonic Doppler system placed over the right brachiocephalic artery. We found that the laser Doppler signal is composed primarily of blood flow supplied by the internal auditory artery. Local pressure on the contents of the internal auditory canal after occipital craniotomy was found to reduce CBF to 15% of its original value in a reversible fashion. There was no change in CBF after bilateral occlusion of the common carotid arteries. There appears to be a mechanism governing CBF that stabilizes its value in the face of changes in blood pressure and cardiac output. This is similar to the vascular behavior of the central nervous system. Through the use of positive airway pressure and blood removal at different rates, cardiac output could be depressed to varying degrees. The magnitude of decrease in CBF was clearly related to the rate at which cardiac output and blood pressure dropped. This was confirmed when intravenous phenylephrine was given in sequential and increasing doses. CBF increased as blood viscosity decreased, as expected according to the vascular behavior of the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Shoulder pain and function after neck dissection with or without preservation of the spinal accessory nerve.

To compare the difference in the degree of pain and functional disability of the shoulder in patients who underwent neck dissection for the treatment of head and neck cancer, 23 patients with and 12 patients without spinal accessory nerve preservation were evaluated with a questionnaire and a physical examination. In addition, to determine what effect radiation treatment has on pain and shoulder disability, eight patients who had whole neck radiation but no neck dissection were similarly evaluated. The results of this study show that, on the average, neck dissection patients with their spinal accessory nerve preserved have less pain in their shoulders, less functional disability, and stronger results on their physical examination than did those with their spinal accessory nerve sacrificed. It was also found that the patients who received whole neck radiation treatment without neck dissection had little pain, infrequent and insignificant functional disability, and normal strength on physical examination.

Influence of the maternal surrogate on pituitary-adrenal activity and behavior of infant squirrel monkeys.

Squirrel monkey infants reared on surrogates showed an increase in vocalizations, but no change in plasma cortisol levels when the surrogate was removed from the home cage for .5 hr. When the infant was exposed to novelty during separation, there was a further increase in vocalizations, as well as increases in movement and plasma cortisol. Placing the surrogate with the infant in the novel environment reduced the behavioral reaction and led to high levels of infant-surrogate contact; however, plasma cortisol levels were as high at .5 hr as when the infant was in the novel environment alone. With longer (2-4 hr) exposures to the novel room, cortisol elevations were attenuated by the presence of the surrogate. When the infant was alone, levels of cortisol, but not protest behavior, increased with length of exposure to the novel room. These results indicate that the physiological reaction to separation procedures in infant primates may not be safely inferred from behavioral responses, and, together with earlier findings, suggest a deficiency in the attachment of surrogate-reared infants.

Oral ethanol intake nad levels of blood alcohol in the squirrel monkey.

Oral alcohol ingestion and blood alcohol levels were examined in adult female squirrel monkeys to assess the feasibility of using this primate as a model for fetal alcohol effects. In one experiment, alcohol intake was evaluated in nonpregnant animals under conditions in which the concentration of ethanol, length of ethanol exposure, and degree of liquid deprivation were varied. In another experiment blood alcohol levels were measured in pregnant animals of two subtypes that had been drinking ethanol. In a third experiment, time-dependent blood alcohol levels and behavior were evaluated in nonpregnant monkeys following intubation of specific doses of ethanol. Results showed that nonpregnant monkeys drank ethanol at concentrations of 5 to 10%, and that the amount of ethanol consumed was related to the concentration and length of time ethanol was available. When given access to a 5% ethanol solution, pregnant animals drank quantities that varied between individuals and subtypes, with maximum blood levels, measured up to 6 hr after presentation, ranging from 1 to 196 mg%. Intubation of ethanol resulted in blood alcohol levels and incoordination scores that were linearly related to dose, with maximum effects occurring 1 hr after administration. Elimination of ethanol from the blood at levels above 50 mg% occurred at a rate of about 35 mg%/hr, while the rate of clearance from the body was calculated to be approximately 250 mg/kg/hr.

Effect of surrogate-administered punishment on surrogate contact in infant squirrel monkeys.

Three experiments were conducted in which surrogate-reared infant squirrel monkeys were exposed to punishment in the form of pressurized air emitted from the bodies of the surrogates. Punishment was administered irregularly during the day between the ages of 6 and 34 weeks, under different schedules of random presentation and at different parameters of the airblast stimulus. Physical contact with the surrogate was recorded separately for day and night activity. The results of all experiments were consistent in showing that punished infants spent less time than did nonpunished controls in contacting their surrogates during the daytime throughout the entire period of study. Nighttime scores were less consistent, but showed the same trend in 2 of the experiments. The results also suggested that different subtypes of squirrel monkeys are inherently different in their degree of surrogate contact, with monkeys of the Bolivian type spending more time in contact than those of either Peruvian or Colombian descent.

The incidence of hypopharyngeal stenosis after surgery for laryngeal cancer.

Hypopharyngeal stenosis is a frequent complication of laryngectomy and radiotherapy in patients treated for carcinoma. In a retrospective study of patients treated in the University of Washington Affiliated Hospitals, hypopharyngeal stenosis was more frequent after laryngectomy with partial pharyngectomy than after laryngectomy alone and occurred more commonly in lesions of the pyriform fossa than in glottic tumors. Neck disease and inclusion of radical neck dissection were both significant factors in the development of hypopharyngeal stenosis. Recurrent tumor was significantly more prevalent in these patients.

Maternal responsiveness in the squirrel monkey following chronic administration of delta 9-THC.

Mother squirrel monkeys were orally administered gradually increasing doses of delta 9-THC (from 0.5 to 5.0 mg/kg) 5 days/wk from 2 wk to approximately 6 mo after birth. After having received a dose of 5.0 mg/kg for an average of 3.5 mo, drug-treated mothers were then compared with control mothers in terms of theri responsiveness both to their own and to unrelated infants. In contrast to the control mothers whose response pattern clearly showed differentiation of their own and other infants, the mothers that received delta 9-THC responded in much the same manner to the alien infant as they did to their own infant. The results show that the behavior of the THC-exposed mothers was not attributed simply to a general reduction in their responsiveness toward their offspring or to an overall reduction in their own state of arousal. Rather, the results suggest that chronic ingestion of delta 9-THC caused the mothers to be less disturbed by separation from their infants and/or produced degree of perceptual distortion that prevented them from responding selectively to the different infants.

Olfactory and visual differentiation of synthetically scented surrogates by infant squirrel monkeys.

Twelve infant squirrel monkeys were reared with distinctively colored and scented inanimate surrogates (Green/Floral or Black/Clove) and tested monthly from 1 to 6 months of age in 3 paired-comparison conditions that assessed the efficacy of synthetic olfactory cues and color cues as attractive properties of the surrogates. The infants developed specific attractions to both the rearing odor and color of the surrogates by approximately the end of Month 4, although substantial differences existed between the 2 rearing groups, particularly with respect to color responsiveness. When compared with previous findings on infant squirrel monkeys reared with naturally scented surrogates, odor preferences developed relatively late, suggesting that natural, species-typical odors may have inherently stronger attractive properties for Saimiri than arbitrary synthetic odors.

Studies with timed-pregnant squirrel monkeys (Saimiri sciureus).

Timed-pregnant monkeys were produced in a large nonhabituated colony of Saimiri sciureus of Bolivian origin. In a colony of 373 females and 40 males, 277 females (74%) were considered to be inseminated, based on microscopic observation of sperm and/or detection of a coagulum (plug) in the vagina. Forty-six full-term progeny were delivered. The mean gestational period was 152.5 days (SD = 3.9 days). For continuous cohabitation, the median time to insemination was five days, with 75% of inseminations occurring within eight days. Pregnancy evaluation (mouse bioassay) indicated a high level of resorptions within the first 50 days of gestation. This may help explain the low birth rates reported for other nonhaibuated colonies.

Olfactory discrimination of squirrel monkey mothers by their infants.

Infant squirrel monkeys, 8 to 24 weeks of age, were tested for their ability to discriminate their own mother from another lactating mother by means of olfactory cues, visual cues, or a combination of both. Discrimination by olfactory cues was unequivocal. Addition of static visual cues did not enhance discrimination, and infants showed little evidence of discriminating the mother by means of static visual cues alone. These results suggest that olfaction may be a more significant factor in primate early attachment than has generally been assumed.

Breeding and rearing squirrel monkeys (Saimiri sciureus) in captivity.

A breeding colony of squirrel monkeys (Saimiri sciureus) was established to provide animals for behavioral research concerned with early development. The origin of the initial breeders was Peru, Colombia, and Bolivia. During the past 10 years, the colony has grown to 125 adult females, 20 adult males, and 120 immature animals of various ages. The annual conception rate for the last 5 years averaged 68%. This resulted in 84% viable births of which 82% survived past 6 months of age. The majority of the births (65%) occurred during June-August, and 87% during May-September. The most efficient and successful breeding strategy was to form mixed-sexed groups of 10--15 females and 2--3 males before the mating season began and to maintain the integrity of these groups with minimal interference. Progeny were reared apart from their natural mother without difficulty, and their growth and development were found to be similar to those of mother-reared monkeys.

The passage of 14C-delta-9-tetrahydrocannabinol into the milk of lactating squirrel monkeys.

Lactating squirrel monkeys chronically receiving 2 mg/kg delta-9-tetrahydrocannabinol (THC) orally either two or five times weekly were given a tracer dose of 14C-delta-9-THC mixed with the delta-9-THC. This permitted radioquantitation of the THC in milk specimens collected 1 to 24 hr after administration of the labeled dose. Correlated specimens of urine and feces were also collected individually from mothers and infants and were subjected to radioquantitation and exploratory TLC. During the 24-hr observation period, approximately 0.2% of the labeled delta-9-THC appeared in the milk, whereas 42% and 1% were excreted in the feces and urine, respectively. Infants that suckled during the 6 hr immediately after their mothers were administered the labeled compound excreted an average of 0.01% and 0.12% of the mother's dose in the urine and feces, respectively, during the 18 hr after suckling.