Mary M. Gerkovich

Use of the McGill Pain Questionaire in the assessment of cancer pain: Replicability and consistency

&NA; The McGill Pain Questionnaire (MPQ) is a recent empirically derived instrument designed to provide quantitative information on major dimensions of pain. Although widely used as an outcome measure in clinical research, little attention has been directed specifically at the instrument itself. The present study addressed this need. Detailed findings were obtained for both single and multiple administrations of the MPQ in two subject samples, each composed of 18 cancer outpatients in pain. These data were compared to similar, but less extensive, data reported by Melzack [6]. MPQ indices proved highly replicable over the two subject samples tested and were remarkably similar to the findings reported by Melzack for a different cancer pain patient sample. No differences were found between the written form of MPQ administration used in the present study and the oral procedure followed by Melzack. The consistency of pain descriptor subclass choice in the present samples was high, ranging from 66% to 80.4% over 4 administrations, and these values compare well with the value of 70.3% reported earlier by Melzack. However, the present subjects selected a larger set of pain descriptor words compared to the word set reported to be characteristic of cancer pain by Dubuisson and Melzack [2]. Both individual and group analyses indicated the MPQ is best used as a measure of immediate pain, and not as a summary measure of past pain over a defined period of time. These findings support the use of the MPQ as a reliable, multi‐dimensional measure of immediate pain, and suggest the potential value of future research aimed at refining the psychometric properties of the instrument.

NOCTURNAL MELATONIN LEVELS IN HUMAN VOLUNTEERS EXPOSED TO INTERMITTENT 60 HZ MAGNETIC FIELDS

Two double-blind laboratory-based studies were performed to determine whether a suppression of nocturnal melatonin similar to that observed in rodents occurs when humans are exposed to magnetic fields at night. In study 1, 33 men were exposed to sham, 10 mG, or 200 mG intermittent, circularly polarized magnetic fields from 2300 to 0700 h under controlled environmental and exposure test conditions. Overall, exposure had no effect on melatonin levels. Men with preexisting low levels of melatonin, however, showed significantly greater suppression of melatonin when they were exposed to light and also when they were exposed to the 200 mG magnetic-field condition. Study 2 directly tested the hypothesis that low-melatonin subjects show enhanced sensitivity when exposed to light and to 200 mG magnetic fields. After preexposure screening, each of 40 men slept in the exposure facility on two nights. On one night, the men were sham exposed. On the other night, they were exposed to the 200 mG field condition used previously. Again, exposure had no overall effect on melatonin levels. The original finding of enhanced sensitivity in low-melatonin subjects was not replicated in this study. We conclude that the intermittent exposure conditions used in these two studies were not effective in altering nocturnal melatonin release patterns in human volunteers. Further research is underway with regard to exposure parameters, hormonal and immune system measures, and individual differences.

Coping in real time: using Ecological Momentary Assessment techniques to assess coping with the urge to smoke.

Coping is important for success at smoking cessation, yet little is known about the natural history of coping with urges to smoke during a cessation attempt. In this study, Ecological Momentary Assessment (EMA) methods were used to gather real-time quantitative and qualitative data. For 3 consecutive days during their first 10 days of smoking cessation, 36 participants used tape recorders and palm-top computers to record details of 389 coping episodes, during which they employed 1,047 coping responses. An average of 3.6 coping episodes per day and an average of 2.7 coping responses per episode were reported. Sixty-seven percent of the responses were behavioral and 33% were cognitive. Gender, location of the episode, nicotine dependence, and quitting history were associated with the use of specific strategies. Results indicate that EMA methods and instruments are feasible for measuring coping responses.

Multi-night exposure to 60 Hz magnetic fields: effects on melatonin and its enzymatic metabolite.

Magnetic field‐induced suppression of nocturnal melatonin in humans has been reported in occupational and residential studies, but not in laboratory‐based exposure studies. The present study examined whether this contrasting pattern of results might be related to associated differences in exposure duration or to field‐induced measurement instability over time. Thirty healthy young men were evaluated using a randomized, double‐blind test protocol. Statistical analysis indicated that 4 consecutive nights of exposure to power‐frequency magnetic fields at occupational intensity (resultant flux density=28.3 microtesla, μT, [283 milligauss, mG]) had no differential effect on concentrations of melatonin or its major enzymatic metabolite (6‐hydroxymelatonin sulfate, 6‐OHMS) in daily morning urine samples, compared to equivalent no‐exposure sham control conditions. The consistency of intra‐individual urinary measurements over the 4 test nights also was quite high (P<0.01) in the sham control condition. In contrast, repeated nightly exposure to the magnetic field was associated with reduced consistency. Morning urinary measures obtained after exposure on night 4 differed (P<0.01) from similar measures obtained after the second and third exposure night. Thus, while the overall results of this study do not support the melatonin hypothesis, there is some suggestion of a possible cumulative effect of magnetic field exposure on the stability of individual melatonin measurements over time. Additional research with longer periods of controlled exposure may be warranted.

Human exposure to 60-Hz magnetic fields: neurophysiological effects

The neurophysiological effects of exposure to power-frequency magnetic fields at two occupationally-relevant intensities were evaluated in a single-blind study with 18 male and 18 female volunteers. Auditory brainstem (BAEP) and somatosensory (SEP) evoked potentials were recorded before, during and after field exposure (duration = 45 min, frequency = 60 Hz, field intensities = 14.1 or 28.3 microtesla, microT), or an equivalent sham-exposure control period. Visual event-related potentials (VEP) to pattern reversal stimuli were also recorded before and after the exposure period. Field exposure had no differential effects on the BAEP, the VEP, or on SEP measures of central conduction time. Men and women showed a similar lack of sensitivity to exposure. The present results do not support the mechanistic hypothesis that the transmission of sensory information to appropriate cortical centers is delayed or distorted by exposure to power-frequency magnetic fields at occupational intensities.

Exposure to strong ELF magnetic fields does not alter cardiac autonomic control mechanisms

Clinical and epidemiological studies attest that alterations in heart rate variability (HRV) are predictive of specific types of cardiovascular morbidity and mortality in otherwise healthy persons. Recent reports also suggest that changes in HRV may be associated with exposure to intermittent magnetic fields (60 Hz, 28.3 microT) in the laboratory and that mortality is increased in cardiac disease categories related to altered HRV for utility workers whose jobs involve longer exposure to elevated magnetic fields. This study combined three approaches to learn more about the specific exposure circumstances under which changes in HRV occur. First, cardiac autonomic control, as indexed by HRV spectral analysis measures, was measured in 24 men during exposure to a much higher intensity field than any previously examined (resultant flux density = 127.3 microT [1273 milliGauss, mG]). Second, HRV measures from the same individual were compared across three relevant test conditions: intermittent and continuous field exposure and during a no-exposure, control condition. Third, electrocardiographic data were analyzed to determine if the precise timing of when the magnetic field switched on or off in relation to the cardiac cycle results in phase-resetting of the human cardiac rhythm. HRV measures were not altered by either field exposure condition compared to the control condition, and no evidence for a phase-resetting mechanism was found. Further research is needed to resolve the differences between the present and the earlier laboratory-based studies of HRV and to determine if cardiac rhythm disturbances are associated with exposure to the more complex magnetic fields found in the man-made environment.

All‐night exposure to EMF does not alter urinary melatonin, 6‐OHMS or immune measures in older men and women

Healthy men (n=22) and women (n=24), 40–60 years of age, were exposed all‐night (23:00–07:00 hr) to 60‐Hz magnetic fields at an intensity (resultant flux density=28.3 microTesla [μT]) well within the occupational‐exposure range, or sham exposed under equivalent, counter‐balanced, no‐exposure (≤0.2 μT) control conditions. Concentrations of melatonin, and the major metabolite of melatonin, 6‐hydroxymelatonin‐sulfate (6‐OHMS), in first‐void morning urine were not altered in either gender by exposure to the magnetic field, compared to control conditions. Statistical analysis also failed to reveal any evidence for exposure‐related alterations in blood concentrations of multiple hematologic and immune system parameters (CD3, CD4, CD8, natural killer [NK] cells). The present results replicate and extend earlier negative findings based on the exposure of young men to power‐frequency magnetic fields.

Nocturnal magnetic field exposure: gender-specific effects on heart rate variability and sleep

OBJECTIVE To determine if controlled exposure to power-frequency magnetic fields alters heart rate variability (HRV) and polysomnographic endpoints in healthy men (n=22) and women (n=24), 40-60 years of age. METHODS A randomized, double-blind, crossover design was used. Study endpoints collected during all-night exposure to 60 Hz magnetic fields at an occupational intensity (resultant flux density=28.3 microTesla, microT) were compared to similar endpoints obtained under equivalent, counterbalanced, no-exposure (< or =0.2 microT) control conditions. RESULTS Older men, but not women, exposed to the magnetic fields showed power reductions in the LF band of the HRV frequency spectrum, which is associated with sympathetically-mediated blood pressure and thermoregulatory control (P<0.04). Older women, but not men, exposed to the fields showed a pattern of disrupted sleep, with reductions in the duration of REM sleep (P=0.03), and strong trends for reductions in sleep efficiency (P=0.06) and total sleep time (P=0.06). CONCLUSIONS The gender-specific effects seen here with older volunteers replicate the results of previous exposure studies with younger men and women.

State-outcome consistency in smoking relapse crises : a reversal theory approach

Previous investigations of smoking relapse crises have found limited within-subject consistency. Several investigators have suggested that greater consistency might be observed if situations were described phenomenologically. Reversal theory provides one phenomenological framework. Two relapse crises from each of 49 ex-smokers were compared, using reversal theory constructs. Maintaining abstinence in both crises was consistently associated with being in serious-minded (telic) and conformist states. Smoking in both crises was consistently associated with being in playful (paratelic) or negativistic states. Crises with different outcomes occurred in different state combinations. The findings suggest that coping strategies should be state-tailored for optimal effectiveness.

Biological Activity of an Intravenous Preparation of Human Vaccinia Immune Globulin in Mouse Models of Vaccinia Virus Infection

ABSTRACT The biological activity of a new intravenous (i.v.) preparation of human vaccinia immune globulin (VIGIV) was evaluated in two mouse models of vaccinia virus (VV) infection. In a mouse tail lesion model, female CD-1 mice were inoculated i.v. with 7 × 104 PFU of VV to produce >10 lesions per tail 8 days later. In a mouse lethality model, female severe combined immunodeficient (SCID) mice were inoculated i.v. with 3 × 104 PFU of VV to produce 100% mortality within 45 days. The ability of VIGIV to reduce tail lesion formation in CD-1 mice and mortality in SCID mice was determined by (i) pretreatment of a lethal VV dose with VIGIV prior to i.v. inoculation into SCID mice and (ii) i.v. administration of VIGIV to CD-1 and SCID mice the day before and up to 8 days after VV infection. VIGIV reduced the proportion of CD-1 mice with >10 tail lesions in a dose-related manner when VIGIV was given 1 day before and up to 1 day after VV inoculation. The pretreatment of VV with VIGIV prolonged survival and decreased mortality. VIGIV (100 and 400 mg/kg) prolonged survival when given up to 4 days after VV inoculation, and the 400-mg/kg dose reduced the mortality rate by 80% when given the day before or immediately after VV inoculation. The biological activity of VIGIV was demonstrated in both the immunocompetent and immunocompromised murine models. The timing of treatment relative to VV inoculation appeared to be important for the demonstration of VIGIVs biological activity.