Psychometric evaluation of the quality of life interview, brief version, in injection drug users.

The authors investigated the psychometric characteristics of the Quality of Life Interview, Brief Version (QOLI-BV; A. F. Lehman, 1995) in 126 injection drug users recruited for a clinical trial. The QOLI-BV assesses global and domain-specific quality of life. Participants completed the instrument at baseline and 3 and 6 months later. Most scales showed acceptable internal consistency. Convergent and discriminant validity were demonstrated through correlations with the SF-36, the Beck Depression Inventory, and demographic variables. Scale means rose over time, suggesting that the QOLI-BV is sensitive to change. Unexpectedly, lower baseline QOLI-BV scores predicted opiate abstinence at follow-up. The QOLI-BV appears to be an acceptable quality-of-life measure for use in clinical trials of opioid dependence treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Progesterone: Review of safety for clinical studies.

Progesterone is a steroid hormone that is important for reproductive function. Progesterone is used in a number of clinical applications and has been investigated as a possible novel approach for treatment of stimulant drug abuse. Extensive clinical studies have been conducted to examine the subjective and physiological effects of exogenous progesterone administration and to evaluate its side effects. This review summarizes the safety and side effects of acute and chronic administration of 3 progesterone formulations (synthetic, natural, and micronized natural), several routes of administration (oral, intramuscular, intravenous, intravaginal, intranasal, transdermal, and rectal), and dosing regimens. Synthetic progestins marketed as Provera, PremPro, and Cycrin are widely used but may produce a number of significant side effects, such as fatigue, fluid retention, lipid level alterations, dysphoria, hypercoagulant states, and increased androgenicity. Natural progesterones are reported to have milder adverse effects, depending on the route of administration. Micronized natural progesterone is available for oral administration, has better bioavailability and fewer side effects than natural progesterone, and is convenient to administer. Therefore, micronized natural progesterone appears to be a safe and effective alternative to synthetic and natural progesterone formulations for variety of clinical and research applications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sample size calculation for non-compliance randomized trials with repeated measurements in binary data

When we have difficulty in recruiting patients into a randomized clinical trial (RCT), we may consider taking more than one measurement per patient to reduce the number of patients needed to achieve a desired power. In this paper, we consider a double blind RCT with two courses of treatment per patient. At each course, a patient assigned to the experimental treatment could switch to receive the placebo if the patient declined his/her assigned (experimental) treatment, and a patient assigned to the placebo could switch to receive the experimental treatment if the patient refused his/her assigned (placebo) treatment as well. Sample size calculation without accounting for this non-compliance can be inadequate when we apply the standard procedure of intention-to-treat analysis for non-compliance trials to test no treatment effect. Based on the simple additive risk model proposed elsewhere, we have incorporated the initial probability of compliance, the dependence of patient's selection of a treatment on his/her previous response, and the variation of probabilities of response between patients into sample size determination. We have included a quantitative discussion that provides an insight into the effect of various parameters on the minimum required sample size. We have also noted the situation in which taking repeated measurements per patient can be most effective to reduce the number of patients needed to maintain a given power.     

Uptake of thallium from naturally-contaminated soils into vegetables

Thallium transfer from naturally (pedogeochemically) contaminated soils into vegetables was studied. Three different types of top-soil (heavy, medium, and light) were used for pot experiments. The soils were collected from areas with low, medium, and high levels of pedogeochemical thallium (0.3, 1.5 and 3.3 mg kg^-1). The samples of vegetables were collected and analysed. The total content of thallium in soil and the type of soil (heavy, medium and light), plant species and plant variety were found to be the main factors influencing thallium uptake by plants. The uptake of thallium from soils with naturally high pedogeochemical content of this element can be high enough to seriously endanger the food chain. These findings are very important because of the high toxicity of thallium and the absence of threshold limits for thallium in soils, agricultural products, feedstuffs and foodstuffs in most countries, including the Czech Republic.     

Recent Exposure to a Dangerous Context Impairs Extinction and Reinstates Lost Fear Reactions.

Rats were shocked in a context and then exposed to that context in the absence of shock. Shorter intervals between these extinction trials produced more long-term freezing than did longer ones, and shorter intervals between the final extinction trial and test produced more freezing than did longer ones. A short interval between a context extinction trial and test with an extinguished conditioned stimulus (CS) produced more freezing than did a longer one, and a short interval between a nonreinforced context exposure and an extinguished CS reinstated freezing when the CS was tested 24 hr later. The results suggest that recent fear acts to favor subsequent retrieval of the memory formed at conditioning rather than extinction and to render the retrieved memory more salient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are normal healthy research volunteers psychologically healthy? A pilot investigation.

Most new drug development in Phase I clinical trials relies on the use of "normal healthy research volunteers" (NHRVs); however, little is known about the personality functioning of these volunteers. Determining whether NHRVs are similar to or different from individuals with "normal" personalities can impact participant recruitment, group assignment, and statistical interpretation of study results. This pilot study was undertaken to gain insight into the demographics, personality functioning, and potential psychopathology of the volunteers who participated in a Phase I confinement clinical drug trial. NHRVs (N=28) in an all-male, Phase I clinical trial completed a battery of questions, including the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and a sociodemographic questionnaire. Fifty percent of the sample showed clinically significant elevations on at least one of the scales. Current findings need to be replicated and expanded through future research. Results must be interpreted with caution because of the small, all-male sample. This preliminary study suggests that there is a difference in personality functioning between NHRVs and the general population. In addition, NHRVs may purposefully distort or conceal self-report information when participating in studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pigeons presented with sequences of false flashes use behavior to count but not to time.

On randomly ordered trials, pigeons were presented with either a blue or a white key that flashed red for 200 ms at a fast (2 flashes/s), medium (1 flash/s), or slow (0.5 flashes/s) rate. The blue key signaled a fixed-interval (FI) schedule in which the first response after 20 s was reinforced, and the white key signaled a fixed-number (FN) schedule in which the first response after 20 flashes was reinforced. In Experiments l and 2, pigeons showed depressed responding to the flash on FI-cued trials and accelerated responding to the flash on FN-cued trials. When the response key was periodically blacked out in Experiments 3 and 4, counting but not timing was eliminated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biochemical Implications.

Discusses the use of experimental animals, particularly rats, in research exploring the effectiveness of compounds such as painkillers. The author describes an experiment testing the effectiveness of a pain killer, Pentazockine. In past clinical trials, if the drug failed to produce the desired analgesic effect with the rats, further experimentation was terminated. In one particular instance, the investigators in a clinical study chose to ignore past failure of the drug on rats and tested the effect of the drug with humans--and it worked. The implications of these unexpected results on further experimentation with rats is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Angular estimation.

In one study, 10 Ss estimated the directional trend (heading) of simulated radar trials, using different response modes; rotary switch adjustment permitted better accuracy than numerical estimation. Varying the displayed length of the simulated trials from –5?? to 1? inches had no apparent effect on estimation accuracy. 5 civilian Ss proved more accurate than 5 airmen. In a 2nd study, 20 Ss estimated the angular position of lines varying in length from ? to 1 inch, using equipment which permitted switch adjustment and numerical estimation only to the nearest 10 degrees. Results were the same as before. In addition, this report notes differences in estimation accuracy and bias related to the actual angle of displayed lines over a 360-degree range, as well as biasing effects of right- vs. left-handed switch adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Topography of spatially directed conditioned responding: Effects of context and trial duration.

Domesticated quail (Coturnix japonica) received a discrete conditioned stimulus (CS) at one end of the experimental chamber paired with the opportunity to copulate with a female quail (the unconditioned stimulus) in a goal box located 112 cm away. Approach to the CS (sign tracking) and approach to the goal area (goal tracking) were measured. The duration of exposure to the experimental context (C) was varied in Experiment 1, and the duration of the conditioning trials (T) was varied in Experiment 2 for independent groups, creating C/T ratios of 1.0, 1.5, 4.5, 45, and 180. Contrary to previous reports of a direct relation between the C/T ratio and conditioned responding, in the present experiments, a shift in the topography and stimulus control of conditioned behavior occurred. Low C/T ratios (1.0–4.5) produced goal tracking controlled by contextual cues, whereas high C/T ratios (45 and 180) produced sign tracking controlled by the discrete CS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)