Global appropriateness of pain drawings: Blind ratings predict patterns of psychological distress and litigation status

Previous studies examining pain drawings of low back pain patients have shown conflicting results in predicting elevations of MMPI scores. A study of 82 patients whose drawings were rated only for overall, anatomical appropriateness was conducted using the SCL-90 rather than the MMPI as the psychological assessment instrument. Significant differences were found between appropriate and inappropriate drawings; however, these differences seem to reflect differences in cognitive style of coping with pain as opposed to psychopathology. The implications and limitations of the study are discussed.     

A temperature conversion nomogram for glycosylated hemoglobin analysis

Analysis of glycosylated hemoglobins by commercial mini-column methods was shown to vary linearly with the ambient temperature. However, the slopes of the temperature dependence lines for diabetic and healthy individuals was different. A method for temperature correction and a nomogram is proposed.     

Serotonergic mediation of descending inhibition from midbrain periaqueductal gray, but not reticular formation, or spinal nociceptive transmission in the cat

Electrical stimulation in the midbrain periaqueductal gray (PAG) and lateral midbrain reticular formation (LRF) strongly suppresses the responses of spinal dorsal horn neurons to noxious heating of the skin. The possible role of serotonin (5-hydroxytryptamine, 5-HT) was investigated by quantitatively comparing certain parameters of descending inhibition from PAG and LRF in normal cats [14,15] and cats whose central 5-HT levels had been reduced by pretreatment with p-chlorophenylalanine (PCPA, 300 or 500 mg/kg i.p., 72 h prior to acute experiment). Single lumbar dorsal horn neuronal responses to noxious radiant heating of glabrous footpad skin(50 degrees C, 10 sec, 1/3 min) were recorded in normal and PCPA-pretreated cats anesthetized with sodium pentobarbital and N2O. Inhibition of neuronal heat-evoked responses during midbrain stimulation (mean frequency 30 Hz, up to 800 microA current intensity) was expressed as percent of the unit's control response in the absence of midbrain stimulation. Inhibition by PAG stimulation of units from cats pretreated with 300 mg/kg PCPA (mean inhibition at 450 microA to 60% of control in 12 units) was not detectably different from that in control (non-pretreated) cats. However, inhibition by PAG stimulation was significantly weaker in units from cats pretreated with 500 mg/kg PCPA (mean to 83.4% of control in 9 units). In the latter group, mean current threshold for inhibition was higher, and slope of current-intensity plots lower, than in the control and 300 mg/kg PCPA pretreatment groups. In contrast, mean inhibition by LRF stimulation was enhanced in the 300 and 500 mg/kg PCPA treatment groups in a dose-related manner. In normal (non-pretreated) cats, systemic administration of the putative 5-HT antagonist methysergide (0.07--1 mg/kg) reduced or abolished inhibition by PAG stimulation in each of 8 units. Low doses of methysergide had little or no effect on inhibition produced by LRF stimulation in 6 units. The results suggest pharmacologically distinct mechanisms of inhibition produced by stimulation in PAG and LRF.     

Unraveling the effects of compensation, litigation, and employment on treatment response in chronic pain

Although it has often been suggested that chronic pain patients who are receiving workmen's compensation or who have litigation pending are less likely to benefit from treatment, the results of outcome studies of this question conducted by various pain clinics have been inconsistent. We hypothesized that poorer outcome in such patients may be related to the fact that they are less likely to be working and that the inconsistent results in the literature may therefore be explained by variability among studies in the percentages of patients who are receiving compensation (or who have litigation pending) who are also working. We examined the relationships among compensation, litigation, employment, and short- and long-term treatment response in a series of 454 chronic pain patients. Compensation benefits and employment status both predicted poorer short-term outcome in univariate analyses; however, when employment and compensation were jointly used to predict outcome in multiple regression analyses, only employment was significant. In additional analyses, only employment significantly predicted long-term outcome, whereas compensation and litigation did not. Our results suggest that it would be valuable to redirect attention away from the deleterious effects of the 'compensation neurosis' and toward the roles of activity and employment in the treatment and rehabilitation of chronic pain patients.     

Extraction of cyclic AMP for the determination in the competitive protein binding assay

The changes in free calcium, total calcium, albumin, protein, pH, lactate, sodium, magnesium, and potassium values during and following venous stasis (3 min at an external pressure of 100 mmHg) with and without forearm exercise have been measured. The pattern of changes observed with time were dependent on the presence or absence of forearm exercise. Without exercise significant changes are only observed at l min following stasis and then the increases are only moderate (free calcium 2.0%, total calcium 2.4%, albumin 6.9%, and protein 5.9%). However, when the forearm is exercised, larger increases (free calcium 8.6%, total calcium 8.4%, albumin and protein 12.4%) were observed for all parameters following stasis. These increases took 1 to 3 min to return to baseline for most parameters. Only potassium and magnesium went below baseline during the recovery period. It is recommended that when a tourniquet is used to aid in obtaining venous blood samples for these analytes, exercise of the forearm be avoided. If forearm exercise is unavoidable, then the sample should be obtained 1 to 3 min after release of the tourniquet.     

Direct observation of pain behavior in low back pain patients during physical examination

Trained observers measured the occurrence of 5 behaviors (guarding, bracing, rubbing, grimacing, and sighing) in a group of 80 low back pain patients undergoing physical examination. Bracing was frequently displayed, rubbing, guarding, and grimacing were moderately frequent and sighing was infrequent. Pain behaviors were much more likely to occur when patients were moving than when they were in a static position. The rate of guarding, bracing, and total pain behavior was predicted by physical examination findings and/or number of prior operations. Patients having longer pain histories were also more likely to show guarded movement. Topics for future research in this area are identified, and the utility of behavioral observation for clinicians is discussed.     

Behavioral treatment of chronic low back pain: Clinical outcome and individual differences in pain relief

The response of 111 chronic low back pain patients to a comprehensive behavioral treatment program emphasizing relaxation procedures is examined. Over the course of treatment, significant reductions were obtained on measures of subjective tension, EMG activity, and pain. Many patients also decreased their intake of analgesic/narcotic agents and reported an increase in activity level. In order to examine individual differences in pain relief, the 28 patients who had the greatest decreases in pain were compared to those who had the least decreases in pain. Patients who had the best outcome in terms of pain relief were significantly more likely to show improvements in other outcome measures. In addition, these patients rated their pain initially as more severe, had continuous pain for fewer years, and were less likely to be on disability or to have had multiple surgical procedures. These results are discussed in the light of recent data from other behavioral treatment studies with chronic low back pain patients and implications for behavioral assessment and treatment are discussed.     

Naloxone fails to reverse pain thresholds elevated by acupuncture: acupuncture analgesia reconsidered

We were unable to demonstrate the reversal of dental acupunctural analgesia following the injection of 0.4 mg naloxone using evoked potential methodology. Since our findings differed from those of Mayer, Price and Rafii who used pain threshold methods, we attempted to replicate their study. Subjects who demonstrated acupunctural analgesia during electrical stimulation of the LI-4 point on the hands received either 1.2 mg naloxone or normal saline under double blind conditions. Pain thresholds elevated by acupuncture failed to reverse when naloxone was given. Review of experimental design issues, other related human subjects research, and animal studies on acupunctural analgesia provided little convincing evidence that endorphins play a significant role in acupunctural analgesia. Because endorphins can be released in response to a stressor, endorphin presence sometimes correlates with acupunctural treatment in animal studies and some human studies, especially those involving pain patients. The primary analgesia elicited by acupunctural stimulation seems to involve other mechanisms.     

Comparative effects of acupuncture in Japan and the United States on dental pain perception

The effects of low frequency electrical acupunctural stimulation on the perception of induced dental pain were compared in two cultural settings. Twenty Japanese and 20 American subjects (consisting of 10 Caucasians and 10 second or third generation Japanese) were tested in two functionally identical laboratories, one at Tottori University in Yonago, Japan and the other at the University of Washington. Each subject underwent a control and an acupuncture session on separate days with subjects counterbalanced for carry-over order effects. Sensory decision theory (SDT) analysis demonstrated a significant reduction in perceptual capability and an increased bias against reporting stimuli as painful following the acupuncture as treatment which was performed bilaterally at traditional facial points. No significant differences between groups in alteration of perceptual capability, bias or pain threshold were demonstrated, indicating that the cultural and racial differences studied did not influence responses to acupuncture in a laboratory setting.     

Connective tissue activation. XVII. Radioimmunoassay of a human platelet derived connective tissue activating peptide (CTAP-III) and specificities of anti-CTAP-III sera

The platelet-derived connective tissue activating peptide (CTAP-III) has been shown to be an important factor stimulating the metabolism and proliferation of human connective tissue cell strains, including synovial tissue cells. The quantities of CTAP-III affecting the cellular changes and the amounts in various biologic fluids and tissues are small. The objectives of this study were to develop a radioimmunoassay (RIA) for CTAP-III and to ascertain the specificities of the anti-CTAP-III sera reagents. The antisera were shown not to cross-react with a number of polypeptide hormones. However, two other platelet proteins, β-thromboglobulin and low affinity platelet factor-4, competed equally as well as CTAP-III for anti-CTAP-III antibodies in the RIA system. Thus, the three platelet proteins are similar or identical with respect to those portions of the molecules constituting the reactive antigenic determinants. The levels of material in normal human platelet-free plasma that inhibited anti-CTAP-III-12S!-CTAP-III complex formation were determined to be 34 ± 13 (S.D.) ng/ml.     

Effect of pyridoxal on growth of nutritionally variant streptococci and other bacteria on sheep blood agar

Supplementation of sheep blood agar with pyridoxal hydrochloride or pyridoxamine dihydrochloride aided recovery of nutritionally variant streptococci; however, it was found to prevent recovery of 6 of 173 (3%) primary isolates of and to adversely affect laboratory recognition of other streptococci. Pyridoxal hydrochloride or pyridoxamine dihydrochloride should not be a routine supplement in all sheep blood agar.     

Potentiation of morphine antinociception by monoamine reuptake inhibitors in the rat spinal cord

Potentiation of the antinociceptive effects of morphine by the tricyclic antidepressants was assayed in awake restrained rats using the tail-flick test. Intrathecally administered amitriptyline, desipramine or sertraline at doses that had no effect themselves (25-30 micrograms) potentiated a subthreshold parenteral dose of morphine (0.5 mg/kg). The morphine potentiating effect of amitriptyline was prevented by prior administration of parachlorophenylalanine (PCPA). This effect of PCPA was not restored by 5-hydroxytryptophan (5-HTP) but was restored when the animals were left for 14 days to replete. The morphine potentiating effects of amitriptyline, desipramine and sertraline were blocked by intrathecal administration of low doses of the serotonin antagonist methysergide and the alpha-adrenergic antagonists yohimbine and phentolamine but not by the beta-adrenergic antagonist propranolol. The results are consistent with the hypothesis that the potentiation of morphine's antinociceptive effect by tricyclic antidepressants depends on activation of both spinopetal serotonin and adrenergic neurons.     

A comparison of phantom sensations among amputees whose amputations were of civilian and military origins

436 people experiencing phantom limb pain, whose amputations were unrelated to military service, filled out a survey concerning stump, phantom and other pain problems as well as demographic data. Their responses were compared with responses of American veterans, whose amputations were related to military service, who filled out an identical survey. The experiences of the two groups and the characteristics of the reported phantom sensations were remarkably similar. Treatment effectiveness was equally dismal for both groups with about 1% reporting effective relief.     

Event-related potential correlates of analgesia; comparison of fentanyl,acupuncture, and nitrous oxide

This study was undertaken to determine whether different analgesic treatments result in a common change in the event-related potentials (ERP) elicited during painful dental stimulation. The effects of electrical acupuncture delivered at 2 Hz to LI-4, the opiate fentanyl 0.1 mg i.V., and the inhalation analgesia mixture of 33% nitrous oxide in oxygen were examined in volunteers undergoing painful tooth pulp stimulation. ERPs were recorded at vertex and subjects provided reports of pain intensity. Discriminant function analysis was used to determine which subset of the pain report and ERP variables could best discriminate baseline from treatment conditions without regard to specificity of treatment. Together with pain report, amplitude of the ERP positive deflection at 250 msec was a significant indicator of analgesia across the 3 treatments. Other changes specific to the individual treatments were also observed. Since the 250 msec amplitude measure was not redundant statistically with pain report, the ERP data provided significant new information about analgesia even though pain report was a very sensitive measure. Pain report alone could account for 48% of the variance across treatments while ERP measures alone accounted for 34%.     

Chronic phantom and stump pain among american veterans: results of a survey

Questions concerning stump, phantom and other pain problems as well as demographic data were mailed to 5000 Americans whose amputations were connected with military service. Fifty-five percent responded and of these, 78% reported phantom pain. No predisposing factors, other than presence of stump pain, correlated with the presence or severity of phantom pain. Of those receiving treatment, only 1% reported lasting benefits from any of a multitude of treatments attempted.     

Inhibition of brain glutamate decarboxylase by glutarate,glutaconate, and β-Hydroxyglutarate: Explanation of the symptoms in glutaric aciduria?

Glutaric aciduria is a disorcer of lysine, tryptophan, and hydroxylysine metabolism characterized by intermittent metabolic acidemia, dystonia, athetosis and mental retardation. It is due to a recessively inherited deficiency of glutaryl-CoA dehydrogeanse, the enzyme(s) which catalyze the dehydrogenation of glutaryl-CoA to glutaconyl-CoA and decarboxylation of the latter to crotonyl-CoA. Abnormal quantities of glutaric, beta-hydroxyglutaric, and glutaconic acids are found in the urine of these patients. The nature of the movement disorder prompted study of the effects of the abnormally excreted metabolites on brain glutamate decarboxylase, an enzyme implicated in the pathogenesis of Huntington's chorea. Glutamate decarboxylase activity was examined in rat and rabbit brain acetone powders, stabilized with pyridoxal phosphate and glutathione. Glutarate, beta-hydroxyglutarate, and glutaconate were competitive inhibitors of this emzyme, Ki values being 1.3 X 10(-3) mol/l, 2.5 X 10(-4) mol/l, respectively. This inhibition may explain the neurological accompaniments of this syndrome.     

Evoked potential assessment of acupunctural analgesia: Attempted reversal with naloxone

The effects of electrical acupunctural stimulation (2 Hz) on pain judgments and evoked potentials are reported for two experiments using dental dolorimetry. In the first experiment subjects received acupuncture at points located in the same neurologic segment as the test tooth. In the second experiment subjects received acupuncture at points on the hands located on acupuncture meridians. In both instances acupuncture resulted in a reduction in pain intensity and smaller evoked potential amplitudes, but naloxone neither reversed the analgesia nor did it affect the evoked potentials. A pilot study was carried out to determine whether manual rather than electrical stimulation would produce an analgesia reversible by naloxone, but it failed to do so. These findings contribute to the growing evidence that acupunctural stimulation significantly reduces pain sensibility in volunteers undergoing dolorimetric testing, but they do not support the hypothesis that endorphin release is a mechanism by which acupuncture exerts analgesia.     

Pain measurement: an overview

The practice and theoretical basis of pain measurement is reviewed and critically examined in the areas of animal research, human subjects laboratory investigation and clinical study. The advantages and limitations of both physiological and behavioral methods are discussed in each area, and subjective report procedures are evaluated in human laboratory and clinical areas. The need for procedures that bridge these areas is emphasized and specific issues are identified. Progress in the technology of pain measurement over recent decades is reviewed and directions for future work are suggested.