Evaluation of an intraruminal device to provide an iodine supplement for sheep

Commercially manufactured intraruminal devices providing iodine supplementation for grazing sheep were tested for three years in a flock of 200 ewes, and iodine release rates and accumulation in tissues were measured in a small flock of first cross ewes and wethers. Retention of the device exceeded 99.5%. The rate of iodine release increased from about 500 �g/d during the first few months to about 1100 �g/d resulting in an effective life of almost three years. The ewes were not iodine deficient, and supplementation by this device did not improve reproductive performance. Thyroxine levels in plasma, and iodine concentrations in tissue, were not elevated to levels which might be considered toxic, confirming the safety of the device.

Nocturnal biofeedback for nocturnal bruxism

Reports have appeared recently describing the successful reduction of nocturnal bruxism through nocturnal biofeedback. These claims of effective treatments rest mainly on the use of a single index of integrated masseter EMG levels as a measure of bruxism and are based only on short-term effects. The present study was conducted to provide a more rigorous evaluation of the effectiveness of nocturnal biofeedback for nocturnal bruxism through the use of all-night polysomnographic recordings. The results from multiple indices of bruxism are internally consistent and indicate that simple nocturnal biofeedback does not appear to be effective in reducing nocturnal bruxing. Recommendations are made for a more comprehensive approach to the treatment of nocturnal bruxism.

The effects of psychological factors on recovery from surgery

This paper has reviewed correlational studies from both inpatient hospital settings and outpatient oral surgery that demonstrate that several psychological factors are related to postsurgical recovery. Examination of these factors indicates that dentists might improve patients' recovery by giving the surgery a more positive meaning (making the outcome seem desirable), improving patients' acceptance of their condition, making patients' expectations more positive and, reducing anxiety about recovery. Other psychological factors may be helpful in identifying patients who need more support, for example, those with higher trait anxiety, vigilant coping behavior, or an internal locus of control. The review of intervention studies indicates that the best preparation techniques include giving positive suggestions and teaching coping techniques. The value of giving increased amounts of information has not been demonstrated. Also, the literature is not conclusive on varying the type of preparation to fit the personality traits of patients.

Gastrin Responses to a test meal in patients with familial medullary thyroid carcinoma

The serum gastrin response to a standard test meal was evaluated in patients with familial medullary thyroid carcinoma (MTC) and in normal subjects. Patients with MTC and elevated plasma calcitonin levels had a lower gastrin response to the test meal than did normal persons or MTC patients who had normal calcitonin levels postthyroidectomy. There was no significant difference between the mean gastrin response of the normal group and that of the MTC patients with normal calcitonin levels. The serum gastrin response was studied before and after thyroidectomy in four patients. In all four, the post-operative response was greater than the preoperative one . We conclude that patients with MTC may have reduced gastrin responses to a test meal. This effect may be related to circulating calcitonin, somatostatin, or other factors related to familial MTC.

First night effects in good sleepers and sleep-maintenance insomniacs when recorded at home

Home sleep recordings were conducted over four consecutive nights with 12 good sleepers and 12 sleep-maintenance insomniacs. Good sleepers showed decreased sleep efficiency and increased min awake after sleep onset on night 1. Insomniacs showed extended latency to onset of the first REM period and decreased REM in the first third of the initial recording night. Good sleepers and insomniacs reported no significant differences in adequacy of sleep between the first and subsequent sleep nights.

Vasopressin and oxytocin content of human fetal brain at different stages of gestation

Pituitaries from 38 human fetuses and 5 microdissected hypothalamic areas from each of 14 fetuses were assayed for vasopressin and oxytocin. The fetuses were between 15 and 34 weeks of gestation. Vasopressin and oxytocin were found in all the pituitary glands and all the hypothalamic areas studied. A trend of increasing content of both hormones was found in the pituitary gland towards the end of gestation with a marked increase in vasopressin/oxytocin ratio. The human fetus synthesizes oxytocin and vasopressin at least from 15 weeks of gestation and the presence of both hormones in the hypothalamus is not limited to the supraoptic and paraventricular nuclei.

The effects of psychological factors and physical trauma on recovery from oral surgery

This study evaluated the effects of several psychological factors on postsurgical recovery while controlling for and also evaluating the effects of the physical trauma induced by the surgery. Subjects were 38 patients (18 males and 20 females) who were scheduled to have four third molars surgically removed. The psychological factors measured included anxiety and expectations about recovery, trait anxiety, coping behaviors, and health locus of control. Surgical trauma was rated after surgery, and the following aspects of recovery were monitored: postoperative pain, interference with normal function, swelling, and healing. Poorer postoperative recovery was significantly predicted by each of the psychological variables and by higher levels of surgical trauma. In addition, the effects of the psychological variables on recovery were shown to be largely independent of the trauma effects. The data suggest that (a) future studies which give patients more positive expectations and reduce their anxiety about recovery may improve their recovery and (b) the types of patients most in need of preoperative psychological support would be those who have higher trait anxiety, vigilant coping behaviors, or an internal locus of control.

Oxytocin in microdissected hypothalamic nuclei. Significant differences between prepubertal and sexually mature female rats

We measured the concentration of oxytocin and vasopressin in microdissected areas of the hypothalamus and posterior pituitary in weanling and adult female rats. Oxytocin concentration was significantly less in adult rats as compared to weanling rats in the supraoptic nucleus, median eminence, and retrochiasmatic area with no significant differences in vasopressin content. This may indicate differences in hypothalamic-neurohypophyseal pathways in adult and weanling rats. There was a significantly greater concentration of oxytocin in the adult rat in the paraventricular nucleus, suprachiasmatic nucleus, anterior hypothalamic nucleus, and posterior pituitary, again with no significant difference in vasopressin concentration. Our results are consistent with a role for sexual maturation in increasing synthesis of oxytocin in specific hypothalamic nuclei resulting in increased storage of oxytocin in the posterior pituitary.

The relation between patterns of ovarian follicle growth and ovulation rate in sheep

The number and growth rate of follicles within classes based on granulosa volume were determined for ovaries taken from groups of 4-5-year-old, fine-wool Merino ewes drawn at different times of the year from a single strain flock maintained at Armidale, N.S.W. The breeding season of the flock normally extends from February to October and the mean ovulation rate rises from about 0.5 in February to about 1.8-1.9 during April-May. Ewes sampled when they were anoestrous or had one (single-ovulatory) or two (twin-ovulatory) recent corpora lutea did not differ in respect to the mean total number of ovarian follicles, the mean number of follicles in individual classes, the time for follicles to complete their rapid growth stage, or the incidence of follicle atresia. However, the ovaries of twin-ovulatory ewes contained significantly more follicles in the two terminal classes within the rapid growth stage than did the ovaries of single-ovulatory or anoestrous ewes (2.2 v. 0.9 and 1.0). This difference was attributed to the differing numbers of follicles per day entering into the rapid growth stage (5.2, 4.5 and 3.7 respectively in twin-ovulatory, single-ovulatory and anoestrous ewes).

Levels of arginine-vasopressin and oxytocin in the pituitary gland and individual hypothalamic nuclei of the genetically obese Zucker rat

Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, Maryland 20014, U.S.A. and *Department of Medicine, Ohio State University, College of Medicine, Columbus, Ohio, U.S.A.

(Received 20 September 1977)

The genetically obese Zucker rat exhibits several endocrine disorders, including defects of the female reproductive system such as delayed puberty, irregular oestrous cycles, failure to mate and refractoriness to pseudopregnancy-inducing stimuli (Saiduddin, Bray, York & Swerdloff, 1973). Zucker rats show hyperdipsia, increased plasma osmolality and excrete a large volume of urine with a decreased osmolality and an increased protein content, suggesting a deficiency in the regulation of body fluids (York & Bray, 1971, 1973; Bray, York & Swerdloff, 1973). These considerations, plus the recent findings that in Zucker rats the concentration of noradrenaline is reduced in the hypothalamic paraventricular nucleus and increased in the median eminence (Cruce, Thoa & Jacobowitz, 1976), prompted us to measure levels of arginine-vasopressin (AVP) and

Immunoreactive vasopressin and oxytocin: concentration in individual human hypothalamic nuclei

Individual hypothalamic nuclei were microdissected from brain tissue of ten human subjects who had died suddenly while in apparent good health. Appreciable amounts of vasopressin and oxytocin immunoreactivity were found by specific radioimmunoassay in six hypothalamic nuclei including supraoptic and paraventricular nuclei. Vasopressin and oxytocin are presumed to be synthesized in supraoptic and paraventricular nuclei for axonal transport to the posterior pituitary for storage and release. Vasopressin and oxytocin in other hypothalamic nuclei may be a part of this system of neurosecretion or may serve some other function.

The incidence of dystocia in Dorset Horn ewes

The incidence of dystocia was recorded in flocks of Dorset Horn ewes lambing in winter, spring or summer and grazed at 8, 12 or 16 ewes per hectare over a ten-year period. The mean incidence of dystocia was 34% of ewes lambing. Significantly more ewes experience a difficult birth at winter (35%) and spring (39%) than summer (26%) lambings. Neither stocking rates nor pre-lambing ewe bodyweight were related to the incidence of dystocia. The incidence of dystocia was significantly greater in 2-year-old ewes than in any other age group. Foetal size was of major importance in the occurrence of dystocia. Approximately 60% of single and twin born lambs that had birth weights greater than 4.5 kg had a difficult birth whereas in lambs weighing less than 3.2 kg only about 10% were affected. Thirty-six per cent of all perinatal mortality was attributable to dystocia. Approximately 27% of single and 73% of twin presentations in assisted births were abnormal, 31% of all lambs assisted had 1 or both legs retained, 4% had posterior (including breech) presentations and the remaining 8% were of varied forms of malpresentation. Significantly more single male than female lambs experienced a difficult birth and the mean birth weights of single, twin and triplet born lambs that had a difficult birth were greater than the birth weights of singles, twins and triplets born normally.

Vasopressin and oxytocin are depleted from rat hypothalamic nuclei after oral hypertonic saline

Vasopressin and oxytocin were measured by radioimmunoassay in rat posterior pituitary and microdissected hypothalamic areas after 3 and 10 days of oral 2 percent sodium chloride in place of drinking water. There was a significant decrease in concentration of both hormones in posterior pituitary and in specific areas of the hypothalamus. Supraoptic, paraventricular, and arcuate hypothalamic nuclei and the retrochiasmatic area had decreased concentration of one or both hormones following hypertonic saline, while hormone concentration in the suprachiasmatic nucleus and median eminence was unaffected.

Oxytocin content of microdissected areas of rat hypothalamus

Oxytocin content has been measured by radioimmunoassay in microdissected hypothalamic nuclei. Equal concentrations of oxytocin were found in the supraoptic and the paraventricular nuclei, indicating that both are major sources of the hormone. The concentration of oxytocin in the median eminence was more than three times that in either the supraoptic or the paraventricular nuclei, and significant amounts of oxytocin were also found in the arcuate nucleus and in tow anterior hypothalamic nuclei.