Double-blind Placebo-controlled Experiments Research Articles

EXPERIMENTAL RAISING OR LOWERING OF TESTOSTERONE LEVEL AFFECTS MOOD IN NORMAL MEN AND WOMEN

In two randomized double-blind placebo-controlled experiments, 63 normal nonclinical men and women received treatments designed to raise or lower their testosterone levels. Sixteen men and 17 women applied testosterone or placebo gel to their skin for five-day periods, and 13 men and 17 women ingested capsules of licorice extract (which lowers testosterone) or placebo for four-day periods. Subjects described their feelings on daily check lists, wrote paragraphs summarizing their experience, and completed implicit-attitude measures. Testosterone increased arousal and hostility, and licorice decreased energy and positive affect. Reactions were stronger among women than among men.

THE ALPHA-KETOGLUTARATE DELIVERING SYSTEM FOR CREATINE SUPPLEMENTS IN ELITE ATHLETES

363 In this study, the effect of Creatine a-Ketoglutarate (Cr-αKG) was investigated in elite athletes. The procedure of a-KG organic synthesis included production of a bio-heterodimer (BHD), with N-terminals of two molecules of Cr conjugated with both C-terminals of one molecule of α-KG as delivery vehicle. Ten power lifters voluntarily participated in a three months double-blind placebo-controlled (P) experiment. A high intensity free-weight lifting program was adopted. Physical performance, anthropometric, and clinical laboratory blood tests were taken thrice throughout this period. One dose of Cr-αKG equivalent to 4 g· day−1, resulted after one month, compared to (P), in: 1) 10:1 effect by self-evaluating questionnaire; 2) increased squat max., bench-press max., dead-lift max.(p<0.05), number of reps in bench-press and squats with 30% max. weight (p<0.01), upper max.force (p<0.05), stand long jump (p<0.02), decreased time of 70% weight max./10 reps bench-press and squat (20%); 3) increased (weight/height)/body fat index (p<0.05); 4) decreased WBC (3%) and granulocytes (1%), increased RBC (3.5%), Hg (2.8 %), HTC (p<0.05), lymphocytes (p<0.05), and lymphocytes/ granulocytes index (10%). Chemistry blood tests indicated slight glucosemia (6.8 %), less increased cortisol (p<0.05), BUN, Crn, and CO2, and decreased BUN/ Crn (7%), and anion GAP (p<0.05). These data suggest that Cr-αKG as it is formulated in the tested nutrition supplement improves power output physical performance, body composition, and some of characteristic homeostatic indices in elite athletes. Sponsored by Silber SportMed Elite Technologies (SSMET), Inc.

Preferences for ethanol and diazepam in anxious individuals: an evaluation of the self-medication hypothesis

The self-medication hypothesis of addictive disorders postulates that individuals with psychiatric symptoms use drugs to alleviate their symptoms. Although commonly cited to explain the etiology of substance abuse, self-medication has not been experimentally validated. This study evaluated one version of the self-medication hypothesis by formulating it into a testable hypothesis: are highly anxious volunteers more likely to self-administer anxiolytic drugs than non-anxious controls. Anxious (ANX, n = 22) and control (CTL, n = 23) subjects participated in two double-blind placebo-controlled experiments, one testing ethanol (0.8 g/kg) and the other testing diazepam (20 mg). Subjects sampled and then chose between ethanol and placebo in one experiment, and diazepam and placebo in the other. The main dependent measures were choice of drug over placebo and subjective responses to the drugs. Ethanol decreased self-reported anxiety in ANX subjects, but ANX subjects did not choose ethanol more often than CTL subjects. Diazepam did not measurably reduce anxiety, but ANX subjects nevertheless chose diazepam more often than did CTL subjects. Thus, there were some differences in drug responses between the ANX and CTL subjects, and the study provided limited support for the self-medication hypothesis. However, drug choice was not directly related to anxiolytic drug effects with either ethanol or diazepam. The procedure may be used to test other formulations of the self-medication hypothesis (e.g., examining other psychiatric risk factors).

AMPT partially reverses euphoric but not psychomotor effects of alcohol in humans

There are two dopaminergic brain systems that may be involved in the action of alcohol—the mesolimbic dopamine (DA) system, presumably by mediating alcohol-induced euphoria, and the mesostriatal DA system, by acting as a tonic regulatory system. In a double-blind placebo-controlled experiment, either 1,750 mg of alpha-methyl-para-tyrosine (AMPT; an inhibitor of tyrosine hydroxylase), 0.65 g/kg of alcohol, both substances combined, or a placebo only were applied to 60 healthy male subjects. Pretreatment with AMPT resulted in a pronounced reduction of urinary levels of DA, DOPAC, and HVA and caused a marked reduction in alcohol-induced euphoria, as indicated by self-ratings of joyfulness. Alcohol caused a decrease in experienced feelings of alertness and concentration as well as in critical-flicker-fusion (CFF) threshold values. In addition, lift-off time, representing a subcomponent of reaction time, was increased by alcohol, but was unaffected by AMPT. This pattern of results supports the notion of two distinct dopaminergic brain systems mediating behavioral effects of alcohol and, further, is in agreement with the hypothesis of differential sensitivity of dopaminergic and GABAergic mechanisms underlying the biphasic action of alcohol.

Ceruletide analgesia in biliary colic.

Ceruletide is a decapeptide isolated from the skin of an Australian frog. Its chemical and biologic relationship to cholecystokinin and its potent relaxant effect on the sphincter of Oddi makes it useful in biliary colic. In this double-blind placebo-controlled experiment, 60 subjects with moderate to severe pain caused by biliary colic were injected with ceruletide, 1 ng/kg iv or with an equal volume of saline solution. Pain in the right hypochondrium, referred pain, and Murphy's sign were scored before and after treatment. Data indicate that ceruletide is effective in biliary colic.

Prevention of aspirin-induced fecal blood loss with oral prostaglandin E 2: Dose-response studies in man

The purpose of this study was to determine the minimum effective protective dose of PGE 2 given concurrently with ASA. Thirty-two adult male volunteers completed a double-blind placebo-controlled experiment. Fecal blood loss was measured by the 51 Cr technique for 15 days. ASA (650 mg four times daily) was given for the middle 5 days and in addition subjects received PGE 2 orally in doses of 0.04 mg, 0.25 mg or 0.5 mg or placebo four times daily. In the control group ASA caused a significant increase in fecal blood and this was reduced in a dose-dependent manner by the three doses of PGE 2 employed. Serum salicylate was elevated similarly in all four groups. Four subjects receiving 0.5 mg PGE 2 experienced mild transient side effects. It is concluded that concurrent treatment with oral PGE 2 affords significant dose-dependent protection against ASA-induced gastrointestinal blood loss and that even a dose of 0.04 mg four times daily provided some protection.

WAKEFULNESS CAUSED BY CAFFEINE.

Certain psychotropic effects of caffeine were investigated in doubleblind placebo-controlled experiments with 230 medical students.