Modulation of chemiluminescence in a murine macrophage cell line by neuroendocrine hormones.

This study determined the effects of neuropeptides and neuroendocrine hormones at the cellular level of the immune response using a murine macrophage cell line, J774, which exhibits a chemiluminescent oxidative burst upon acute stimulation with zymosan. We report that the zymosan-triggered oxidative burst of J774 cells can be modulated by the opioid peptides beta-endorphin (beta-END) and dynorphin A (DYN) in a naloxone-reversible fashion. Norepinephrine (NE) also modulated chemiluminescence (CL) emission of J774 cells, with dose-dependent suppression of CL dependent upon co-incubation with gamma-interferon (gamma-INF). Without gamma-INF co-incubation, NE shared with the opioid peptides beta-END and DYN the ability to modulate oxidative burst, producing an inverted-U dose response. These data indicate that J774 cells may be useful for explaining some mechanisms through which the neuroendocrine system interacts with the immune system.

Effects of the interaction between ferric iron and L-dopa melanin on T1 and T2 relaxation times determined by magnetic resonance imaging.

T1 and T2 relaxation times of agar phantoms containing L-dopa melanin and Fe3+ were measured under MRI conditions. Fe3+ shortened T1 and T2 relaxation times. Melanin influenced relaxation times only in the presence of Fe3+; thus, contrast in MR images of the basal ganglia may depend upon levels of both paramagnetic iron and neuromelanin.

Prostaglandin synthesis and response to alcoholism treatment.

Serum prostaglandin F2 (PGF2) was assayed in 27 alcoholic patients and in 18 control subjects. No significant difference was observed in mean basal PGF2 titers of patients and controls. However, patients who completed four months of alcoholism treatment had a mean titer that was significantly higher than that of treatment dropouts. Patients who maintained continuous abstinence for 2 years following treatment had a mean titer that was significantly higher than that of patients who returned to pre-treatment drinking levels.

Prostaglandin synthesis among alcoholic suicide attempters and nonattempters.

Serum PGF2 alpha titers were examined in 8 sober alcoholic males who had attempted suicide and 19 nonattempting alcoholic males. Two of the 8 attempters had used violent means and the remaining 6 had used nonviolent means. The suicide attempters had significantly lower PGF2 alpha titers, relative to the nonattempters (p less than 0.005), with the violent attempters expressing maximally reduced titers. There were no significant differences between the groups with respect to age, alcohol consumption patterns, or admission scores on the Beck Depression Inventory.

Current progress toward the prevention of the Wernicke-Korsakoff syndrome.

The Wernicke-Korsakoff syndrome is a rare neurological disorder which strikes primarily alcoholics and is caused, at least in part, by insufficient bioavailability of thiamin. Because of the low cost of preventing this disease by adding thiamin to alcoholic beverages relative to the cost of the long-term care of patients with the chronic phase of the disease, there has been a need to determine the feasibility of this particular preventive strategy. Recent data demonstrating normal levels of erythrocyte transketolase in patients presenting with Wernicke's encephalopathy has led some to question the link between thiamin deficiency, and the development of the syndrome, despite the fact that virtually all patients with Wernicke's encephalopathy will respond favorably to parenteral thiamin, and the evidence that rats deprived of thiamin develop lesions that are characteristic of the disease. Thiamin is nontoxic, is stable in alcoholic beverages, and is undetectable in beer to professional taste-testers at levels theoretically sufficient to guarantee adequate absorption. Although there is much inter-subject variability it appears that thiamin at therapeutic concentrations can be absorbed by the jejunum in the presence of alcohol. Evidence that patients with the Wernicke-Korsakoff syndrome have an altered thiamin-requiring isoenzyme and evidence that six patients with Wernicke's encephalopathy failed to respond to oral thiamin has caused some doubt as to whether the target population would be able to benefit from the measure. Other determinants of thiamin utilization, such as folate and magnesium status, also may figure in the etiology of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Circannual changes in immune function.

Adrenocortical activity varies on a circannual basis with increased secretion in the winter and decreased secretion in the summer. One consequence of this variation is a circannual pattern in immune function. Adrenal corticosteroids, especially glucocorticoids, depress cellular immune function and seem to be more effective against T-suppressor cells. Thus, when adrenocortical activity is elevated, T-cell activity is depressed and B-cell activity is elevated. To the extent that T-cell "surveillance" is depressed in winter, there should be increased lymphoproliferative cancer risk during winter and in regions characterized by cold climates. This article presents data which suggest: (1) a winter, adrenal-corticoid induced, depression of T-cell function which is accompanied by elevated B-cell function; (2) elevated serum immunoglobulin levels in the winter; and (3) an inverse relationship between ambient temperature and serum immunoglobulin levels. The circannual pattern in immune function could help explain increased lymphoproliferative cancer risk, as a side effect of immunosuppression therapy during organ transplants, and as a function of latitude.

Marijuana effects on simulated flying ability.

The authors studied the effects of marijuana intoxication on the ability of 10 certified airplane pilots to operate a flight simulator. They used a randomized double-blind crossover design to compare the effect of active versus placebo marijuana. They found that all 10 pilots showed a significant decrease in measurements of flying performance 30 minutes after smoking active marijuana. For a group of 6 pilots tested sequentially for 6 hours, a nonsignificant decrease in flying performance continued for 2 hours after smoking the active drug. The authors conclude that the effects of marijuana on flying performance may represent a sensitive indicator of the drug's psychomotor effects.

Simulated flying performance after marihuana intoxication.

Ten pilots smoked, in counterbalanced order on a double blind basis, a social dose of marihuana (.09 mg/kg delta-9-tetrahydrocannabinol) and a matched placebo after being trained to fly a specific flight sequence on an ATC-510 flight simulator. In contrast to placebo, marihuana caused a gross decrement in flying performance, with increased prevalence of major errors, minor errors, altitude deviations, heading deviations, and radio navigation errors. These effects of active marihuana persisted for at least 2 hr and generally had disappeared by 4 to 6 hr after marihuana administration.

Chromosomal effect in vivo of exposure to lysergic acid diethylamide.

Chromosome studies of persons exposed to lysergic acid diethylamide, either self-administered or received during medical therapy, failed to demonstrate significant chromosomal damage.