The efficacy of protein supplementation in overcoming urea toxicity in sheep.

1. In the first experiment sheep taken from pasture were given a low-protein diet for six weeks in individual pens. Then, for 1 week, groups were given a supplement of lucerne chaff, safflower meal or lucerne chaff plus safflower meal. In the second experiment eighteen sheep maintained on lucerne chaff rather than pasture were then depleted of protein to a greater extent by feeding on a restricted low-protein diet. Six of the sheep received a supplement of molasses throughout the period of protein depletion while six of the sheep on the basal ration received a supplement of safflower meal after 6 weeks on the low-protein diet. 2. The urea tolerance of the sheep, is indicated by blood ammonia levels after oral dosing with aqueous solutions of urea, was determined after the period of supplementation. "Arginine synthetase" activity (combined activities of argininosuccinate synthetase (EC 6.3.4.5) and argininosuccinate lyase (EC 4.3.2.1) was determined in liver samples obtained by biopsy at various intervals during the experiment. 3. Supplementation for 7 d with 73 g crude protein (nitrogen X 6-25)/d increased the tolerance to urea as indicated by reduced blood NH3 levels, and also increased "arginine synthetase" activity. 4. Giving supplements of molasses delayed the onset of urea toxicity but not the extent of toxicity. 5. It is suggested that short-term feeding of protein concentrates to sheep before giving urea supplements can increase their tolerance to urea.     

Cerebral atrophy in Cushing's disease

BACKGROUND: Cushing's disease causes significant pathological changes throughout the body as a result of elevated cortisol levels. Very few systematic investigations have focused on the morphologic effects of hypercortisolism on the central nervous system. The validity of using premature cerebral atrophy as a diagnostic tool for Cushing's disease remains unknown. METHODS: This study includes 63 patients with Cushing's disease who were evaluated and treated at the University of Virginia Medical Center. Radiologists randomly compared these individuals with age- and sex-matched controls in a blinded protocol, assessing the degree of cerebral atrophy on computed tomography and magnetic resonance scans. RESULTS: Patients with Cushing's disease showed significant premature atrophy when compared with controls. This trend continued after subdividing the groups based on age and duration of symptoms except in the following groups: age greater than 60, duration of symptoms less than 1 year, and symptoms lasting between 4-5 years. CONCLUSIONS: Excluding the three aforementioned groups, the hypercortisolemic state manifested in patients with Cushing's disease promotes the premature development of cerebral atrophy, which can be identified on routine radiologic imaging and may assist in the clinical diagnosis of the condition.     

Increased placental apoptosis in intrauterine growth restriction

OBJECTIVES: Our purpose was to investigate a possible role for apoptosis in the pathophysiologic mechanisms of intrauterine growth restriction. STUDY DESIGN: Placental samples were obtained from 43 uncomplicated third-trimester pregnancies and from 26 pregnancies complicated by intrauterine growth restriction. The definition used to identify cases of intrauterine growth restriction depended on three criteria: clinical evidence of suboptimal growth, ultrasonographic evidence of deviation from an appropriate growth percentile, and individualized birth weight ratios <10th percentile. Light microscopy was used to quantify the incidence of apoptosis. Electron microscopy and TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick end labeling) staining were used to confirm the occurrence of apoptosis. RESULTS: Quantification of apoptosis (medians and interquartile ranges) resulted in the following values: normal third trimester (n = 43) 0.14% of cells (0.08% to 0.20%) and intrauterine growth restriction third trimester (n  = 26) 0.24% of cells (0.16% to 0.29%). The incidence of apoptosis was significantly higher in placentas from pregnancies with intrauterine growth restriction compared with normal third-trimester placentas (p < 0.01, Mann Whitney U test). CONCLUSIONS: These results suggest that apoptosis may play a role in the pathophysiologic mechanisms of intrauterine growth restriction.(Am J Obstet Gynecol 1997;177:401)     

A TEN-YEAR HOSPITAL SURVEY OF EYELID CANCER

Two hundred and four cases of malignant eyelid tumours, managed at the Concord Hospital, were reviewed. These cases spanned a ten-year period between 1973 and 1982 and all were treated surgically. The nature of each tumour was confirmed by histopathological examination. Included in this review were the site of the tumour, the tumour pathology, the surgical management, the type of surgeon involved, the ocular complications, the management of recurrences and any mortality. The importance of preventing recurrences by adequate initial surgery with frozen section control is emphasized.     

Clinical exophthalmometry: a comparative study of the Luedde and Hertel exophthalmometers

Exophthalmometry, the quantitative assessment of the position of the globe in the orbit, is a clinically useful measurement. The purpose of this study was to examine the performance of a simple exophthal-mometer that would lend itself to accurate and convenient use in clinical practice. In this study, two observers independently performed exophthalmometry on 100 eyes using the Hertel and Luedde instruments. The results were compared between instruments and between observers. There was no statistically or clinically significant difference between measurements taken with the Luedde as compared with the Hertel instrument. The Luedde exophthal-mometer has a number of advantages over the Hertel exophthalmometer, and represents a simple, inexpensive and equally reliable means of evaluating clinically the anteroposterior position of the eye in the orbit.     

A possible mechanism of action of danazol and an ethinylestradiol/ norgestrel combination used as postcoital contraceptive agents

Twenty-seven women requesting postcoital contraception were randomly allocated to take an ethinylestradiol/dl-norgestrel combination or danazol. Urine specimens were assayed for luteinising hormone (LH) and pregnanediol-3-glucuronide (P3G) levels from the day of the postcoital treatment to the next period. In addition, the urine samples of these recruits and 12 additional women were assayed for the Beta-subunit of human chorionic gonadotropin (B-hCG). A consistent pattern of alteration in urinary steroids was lacking, indicating a heterogenous effect on ovarian function. There was no evidence of early pregnancy in successfully treated cases. We suggest that the main mechanism of action of these drugs is at the endometrial level.