Differential effects of naloxone on basal and stress-induced release of ACTH and prolactin in the male rat

The effect of i.v. injection of various doses of naloxone (NAL) on plasma adrenocorticotropin (ACTH) and prolactin (Prl) in conscious animals bearing an indwelling intrajugular catheter was assessed. The effects were evaluated in animals which were left undisturbed and in others subjected to either restraint or ether stress. The results revealed that the dose of 3 mg/kg of NAL significantly reduced basal Prl levels, whereas a dose of 6 mg/kg of NAL was required to block completely either ether or restraint stress-induced release of Prl. The behavior of ACTH contrasted with that of Prl. There was no effect whatsoever of the 3 mg/kg dose of NAL on either resting or stress-induced ACTH levels, whereas a 6 mg/kg or 12 mg/kg dose of NAL elevated resting ACTH levels and only partially attenuated the further elevation induced by stress in these animals. The results clearly indicate a NAL sensitive step in the control of resting and stress-induced Prl release but indicate that the control of resting and stress-induced release of ACTH is different in that the predominantly millimicron receptor blocker, NAL, can elevate ACTH at high doses and can only partially block the response to stress. In contrast to Prl where opioid peptide control is solely stimulatory, this control of ACTH secretion appears to have both stimulatory and inhibitory features.     

Ultrastructure and electrical activity in developing heart cells (insect)

Ultrastructural and electrophysiological studies on developing heart cells of the moth Hyalophora cecropia are reported. The myocardium is identified at 6 days postoviposition (dpo) and heartbeats are detected at 8 dpo. At 10 dpo eclosion produces a larva. Cellular ultrastructure of the heart is presented from 6, 7, and 8 dpo embryos and first-instar larvae. Electrophysiological recordings are presented to demonstrate that the developing heart is myogenic, cells generate typical cardiac-type action potentials, and some mechanism for intercellular communication is present. The structure as it relates to function is discussed.     

Material Flow Optimization in By‐product Synergy Networks

By‐product synergy (BPS) is an industrial ecology practice that involves utilization of industrial by‐products as feedstocks for other industrial processes. A novel decision support tool is developed to analyze BPS networks that involve material processing and transport among regional clusters of companies. Mathematical programming techniques are used to determine the optimal network design and the material flows that minimize total cost or environmental impacts. This methodology is incorporated into a graphical software package called Eco‐Flow?. The tool has been applied to model and analyze available synergies in an existing BPS network centered in Kansas City, Missouri. A base case, which assumes no synergies, is compared with the optimal BPS solution found by Eco‐Flow?. The results for Kansas City suggest that when companies in the network cooperate to optimize the system profitability, up to $15 million per year of savings are possible. The findings also indicate that the BPS approach would result in 29% reduction in total cost, 25.8% reduction in average company cost, 30% reduction in carbon dioxide (CO₂) emissions, and 37% reduction in waste to landfill. The modeling approach is being extended to better represent the dynamics of industrial and ecological processes.     

Compliance and side effects in sleep apnea patients treated with nasal continuous positive airway pressure.

Nasal continuous positive airway pressure (CPAP) is an effective therapy for sleep apnea. We treated 144 patients with nasal CPAP and observed them for periods of as long as 25 months. No pneumothoraces occurred in any patient. Compliance rates were between 65% (90/139) and 83% (90/108), depending on the patient population considered. Demographic factors unrelated to discontinuing using CPAP included age, sex, and the presence of a housemate. Better-educated patients were less able to tolerate the equipment. Dry throat and nose and sore eyes were the most common side effects, but only sore eyes related to the amount of pressure. Side effects were unrelated to the number of months on the treatment, and obesity was related to higher pressures. Our study provides optimistic intermediate-term follow-up observations of patients on nasal CPAP therapy for sleep apnea. Whether adverse consequences occur over longer periods of time remains to be seen.