ABSTRACT
1. While changes in corticosterone (B) during late embryogenesis are thought to play a role in the hatching process, only a scant and controversial literature exists concerning the effects of in ovo B on the length of incubation and chick body weight at hatching. Because female Japanese quail selected for exaggerated (high stress, HS) rather than reduced (low stress, LS) plasma B response to brief mechanical restraint deposit more B into their eggs, these stress lines provide an excellent model to study the relationship between embryonic B and incubation length and hatchling body weight. 2. Differences in the duration of incubation and chick body weight at emergence were assessed using eggs laid by LS and HS quail. 3. On average, eggs from HS hens hatched 3.7 h sooner than did eggs from LS hens while mean body weight at emergence was similar in hatchlings of both lines. Thus, selection for exaggerated adrenocortical responsiveness is associated with a reduction in the length of egg incubation without altering hatchling body weight. 4. This finding is important to the poultry industry because it warns layer, breeder farm and hatchery managers that unless stress in hens during egg formation is avoided, an abbreviated incubation period may result.
Subject(s)
Adrenal Cortex/physiology , Coturnix/embryology , Coturnix/genetics , Stress, Physiological/physiology , Animals , Body Weight , Corticosterone/blood , Corticosterone/physiology , Coturnix/physiology , Embryo, Nonmammalian , Embryonic Development/physiology , Female , Oviposition , Restraint, Physical , Selection, Genetic , Stress, Psychological , Time FactorsABSTRACT
The purpose of this double-blind crossover study was to determine whether a sustained-release morphine sulfate (SRMS) tablet given orally every 12 hours could adequately replace immediate-release morphine sulfate solution (IRMS) given orally every 4 hours in hospitalized patients with chronic pain from advanced cancer. Of 33 patients entered, 27 completed the study and were included in the efficacy and safety analysis. Patients were initially randomized to receive either 30-mg SRMS tablets every 12 hours or IRMS at the same mg/24 hours dose, every 4 hours. After 2 days, a crossover was performed, and patients received the alternate treatment for 3 days. Pain and side effects were assessed using a standard 100 mm visual analogue scale (VAS). There were no statistically significant differences between the two treatment groups for mean VAS pain scores or scores for sleepiness, nausea, depression, and anxiety. The incidence of breakthrough pain was similar for both treatment groups, as was the incidence of confusion and constipation. The results demonstrated that SRMS is a safe, effective analgesic preparation for patients who require oral opioids for cancer pain. The data also support the conclusion that sustained-release morphine tablets administered every 12 hours can replace an immediate-release morphine solution administered every 4 hours.
