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Biomedical subjects

J E Sherman

Publications and source records attributed to J E Sherman.

At least 19 recordsLinked to original sources

Relation between self-reported affect and drug urges and cravings in continuing and withdrawing smokers.

In 2 experiments we investigated the effects of withdrawal and stress on the affective correlates of urges to smoke. In both, habitual cigarette smokers were divided into continuing and withdrawing smoker groups. In the 1st study, 44 adults reported current mood, urge, and expectations over a 24-hr period. In the 2nd, a controlled laboratory study, urge, affect, and physiological data were obtained from continuing and withdrawing groups (N = 64) exposed to high- or low-stress conditions. Urges among withdrawing smokers were positively associated with negative affect and negatively associated with positive affect; continuing smokers reported urges that were directly associated with positive affect and unrelated to negative affect. Stress and withdrawal produced urge self-reports that were related to negative affect. Moreover, subjects who smoked after exposure to withdrawal and stress reported greater pleasure and arousal than did other subjects.

Adult

Spinal cord monitoring. Results of the Scoliosis Research Society and the European Spinal Deformity Society survey.

The Scoliosis Research Society (SRS) and the European Spinal Deformity Society (ESDS) membership was surveyed regarding the use of intraoperative monitoring of somatosensory evoked potentials in spinal surgery. A total of 242 people responded, with 188 using intraoperative monitoring. A second survey was distributed detailing the technical aspects of monitoring, of which 71 were returned. A total of 342 neurologic deficits were reported to have occurred with monitoring in place. Two hundred forty-six (72%) were accurately detected, and 96 (28%) were not detected by sensory cord evoked potentials (SCEP). There were 1,003 false-positive cases reported. The incidence of false-negative cases was related to those not monitoring both latency and amplitude, to using fewer recording electrodes, and with those surgeons doing more kyphosis corrections.

Europe

1991 Volvo Award in experimental studies. Cauda equina syndrome: neurologic recovery following immediate, early, or late decompression.

An animal model of cauda equina syndrome was developed. Neurologic recovery was analyzed following immediate, early, and delayed decompression. Five experimental groups, each containing six dogs, were studied. Compression of the cauda equina was performed in all 30 dogs following an L6-7 laminectomy. The cauda equina was constricted by 75% in each group. The first group was constricted and immediately decompressed. The remaining groups were constricted for 1 hour, 6 hours, 24 hours, and 1 week, respectively, before being decompressed. Somatosensory evoked potentials were performed before and after surgery, before and immediately after decompression, and 6 weeks following decompression. Daily neurologic exams using the Tarlov grading scale were performed. At 6 weeks postdecompression, all dogs were killed, and the neural elements analyzed histologically. Following compression, all 30 dogs had significant lower extremity weakness, tail paralysis, and urinary incontinence. All dogs recovered significant motor function 6 weeks following decompression. The dogs with immediate decompression generally recovered neurologic function within 2-5 days. The dogs receiving 1-hour and 6-hour compression recovered within 5-7 days. The dogs receiving 24-hour compression remained paraparetic 5-7 days, with bladder dysfunction for 7-10 days and tail dysfunction persisting for 4 weeks. The dogs with compression for 1 week were paraparetic (Tarlov Grade 2 or 3) and incontinent during the duration of cauda equina compression. They recovered to walking by 1 week and Tarlov Grade 5 with bladder and tail control at the time of euthanasia. Immediately after compression, all five groups demonstrated at least 50% deterioration of the posterior tibial nerve evoked potential amplitudes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Aversion instead of preference learning indicated by nicotine place conditioning in rats.

Although nicotine is a drug of abuse for millions of smokers, it has been difficult to demonstrate clearly the motivational properties of nicotine with rats using the conditioned place preference (CPP) paradigm. The first experiment attempted to replicate CPPs reported by other researchers using nicotine doses of 0.4, 0.8, and 1.2 mg/kg. There was a trend for all three doses to produce aversions, but it was significant only for the 0.8 mg/kg dose. Exposures to the CS alone extinguished aversions, but a "priming" dose (0.2 mg/kg) of nicotine given after extinction produced aversions only in animals exposed to 1.2 mg/kg. Experiment 2 tested whether preexposure to morphine or nicotine would sensitize animals to nicotine's reinforcing effects. In this experiment, rats were exposed to either six nicotine (0.6 mg/kg) or morphine (1.0 mg/kg) dosings prior to preference conditioning. Neither preferences nor aversions were observed in any group following subsequent conditioning with 0.6 mg/kg nicotine. The results suggest that previous observations of preference effects may have been due to specific procedural factors or may have depended on negative reinforcement due to stress reduction.

Animals

Subjective dimensions of heroin urges: influence of heroin-related and affectively negative stimuli.

Thirty-five male drug-free heroin addicts rated their affect, craving, and withdrawal in response to boring, anxiety-eliciting, and heroin stimuli. Results revealed that: (a) heroin cues were more effective than boring or anxiety-eliciting cues in prompting self-reports of craving or withdrawal; (b) heroin cues produced an affective state characterized by self-reported low-pleasure and high anxiety/tension; (c) craving was not correlated with any particular affective state, but rather was associated with a variety of negative affects--anxiety, depression, fatigue, anger; (d) the coherence (intercorrelations) of affective, craving, and withdrawal measures was greatest when addicts made their self-ratings immediately after exposure to drug stimuli; and (e) while addicts routinely reported craving without withdrawal sickness, they virtually never reported withdrawal sickness without reporting craving. These results suggested that the potential for negative reinforcement subserved stimulus elicited craving and that craving involved cognitive appraisal processes (attributions, expectations).

Adult

Corticotropin-releasing factor modulates defensive-withdrawal and exploratory behavior in rats.

The role of corticotropin-releasing factor (CRF), an endogenous neuropeptide, in modulating species-typical responses was examined in an unfamiliar open field containing a small chamber. Rats placed in this small chamber spent most of their time withdrawn in it. However, rats given an intracerebroventricular injection (20 micrograms) of alpha-helical CRF(9-41), a CRF receptor antagonist, emerged from the chamber and explored the unfamiliar open field. Additional studies showed that after 1 exposure to the test environment, vehicle-treated rats increased their time spent in the open field and returned intermittently to the chamber. This result suggests that reexposure reduces the threatening impact of an unfamiliar open field. Importantly, CRF (300 ng) injected centrally, but not peripherally, before reexposure to the test environment significantly reduced exploration in the open field and increased a pattern of defensive-withdrawal into the chamber. Data suggest that whether defensive-withdrawal or exploratory behavior is exhibited may depend on CRF actions in brain systems that mediate the perception of threat in the environment.

Animals

Antagonism of endogenous CRH systems attenuates stress-induced freezing behavior in rats.

Three experiments were conducted to test the hypothesis that brain corticotropin-releasing hormone (CRH) systems mediate stress-induced freezing behavior, an index of a rat's level of fear. We administered i.c.v. 0-50 micrograms of alpha-helical CRH9-41 (a specific CRH antagonist) before foot shock and showed that this peptide had little effect on baseline preshock behavior but significantly attenuated the occurrence of shock-induced freezing. We concluded that this attenuation of freezing behavior was not related to the effects of alpha-helical CRH9-41 on the animals' sensitivity to pain, because no significant effects on latency to respond on a hot-plate test of pain sensitivity were found. We also showed that alpha-helical CRH9-41 has a relatively rapid time course of action when administered i.c.v., since it blocked shock-induced freezing when given 20 min but not 40 min before foot shock. Our findings suggest that endogenous CRH systems mediate stress-induced, fear-related behavior through mechanisms other than alteration of nociceptive systems.

Animals

ICV-CRH alters stress-induced freezing behavior without affecting pain sensitivity.

Freezing is an adaptive response often induced by stressful, fear-eliciting stimuli. Three experiments with rats investigated the effects of intracerebroventricular (ICV) administration of corticotropin-releasing hormone (CRH) on freezing behavior and pain sensitivity. Experiments 1 and 3 demonstrated that ICV-CRH (300 ng) enhanced shock-elicited freezing. In Experiment 1, ICV-CRH also enhanced recovery from shock-elicited freezing, suggesting that the peptide has a biphasic effect. Experiments 2 and 3 established that CRH-induced freezing was not caused by heightened pain sensitivity. Interestingly, in Experiment 2, hot-plate exposure produced increased freezing that was attenuated by ICV-CRH. Thus, the direction of the ICV-CRH effect on freezing was found to depend on the nature of the stressor. These results suggest that endogenous CRH systems modulate stress-induced freezing.

Animals

Chest wall stabilization using plate fixation.

Large defects of the chest wall require stabilization of the remaining thorax to prevent paradoxical movement. A technique of fixation using rib grafts and compression plates is presented.

Adult

The effects of ICV-CRH on novelty-induced behavior.

To assess whether centrally administered corticotropin-releasing hormone (CRH) modulates behavioral and antinociceptive effects of exposure to a novel environment, vehicle or 0.03, 0.3, or 3.0 micrograms of CRH was administered intracerebroventricularly (ICV) to rats, which were then tested under novel or familiar conditions. Novelty decreased sleeping and grooming and increased rearing, walking, and latency to respond on the hot-plate test of analgesia. CRH increased grooming and walking, decreased rearing and sleeping, and had no effect in the hot-plate test. The lowest dose was without effect on any measure; otherwise, CRH effects generally were dose-dependent. There was no evidence that CRH selectively enhanced or interfered with novelty-induced behavioral changes; it influenced behavior to the same degree in both test conditions. However, test condition selectively modulated the degree of peptide-induced self-gnawing and burrowing.

Animals

ICV-CRH potently affects behavior without altering antinociceptive responding.

To explore the hypothesized integrative function of corticotropin releasing hormone (CRH) in the stress response, stress-related behaviors including antinociception were studied in rats after either intracerebroventricular (ICV) or peripheral administration of CRH. The effects of low-dose (0.3 microgram) and high-dose (3.0 micrograms) ICV-CRH were compared to those of vehicle, employing a within-S design. The two doses yielded comparable behavioral changes suggestive of increased arousal and stress. These changes were characterized by significant increases in grooming, walking, burrowing, self-gnawing, and pica, and decreases in rearing and sleeping. None of these effects of ICV-CRH were obtained with peripheral administration of the same doses. The hot-plate test of analgesia failed to show a significant effect of ICV-CRH or peripherally administered CRH. A between-S experiment incorporating both the tail-flick and the hot-plate tests of analgesia compared ICV-CRH (3.0 micrograms) with vehicle. ICV-CRH did not affect antinociceptive responding in either of these tests. In contrast, ICV morphine (10 micrograms) yielded potent analgesia in both tests. Thus, with doses of ICV-CRH yielding clear evidence of stress-related behavior, no evidence of analgesia was obtained. These findings question the possible role of central CRH systems in antinociceptive processes.

Analgesia

Hungry, but not thirsty, rats prefer flavors paired with ethanol.

The present experiments examined the reinforcing effects of an ethanol (EtOH) unconditioned stimulus (UCS) on conditioned flavor preferences in food-deprived rats and in water-deprived rats. In Experiment 1A food and water deprived animals received distinct conditioning treatments. One half of the animals were intragastrically intubated with EtOH (0.5 g/kg), and thereafter allowed 20 min free access to similar flavored drinking solutions. Remaining animals were intubated with distilled water. All animals received 15 presentations of an EtOH-paired flavor. A two-bottle preference test was subsequently used to evaluate preferences or aversions to flavors paired with EtOH in food-deprived and water-deprived animals. Results of Experiment 1A showed that food-deprived animals preferred the flavor associated with EtOH. Conversely, preferences for EtOH-paired flavors were not established in water-deprived animals. In Experiment 1B deprivational states of animals used in Experiment 1A were reversed without further drug training. Following a two week habituation period to deprivation state animals again received a two-bottle preference test to re-evaluate preferences or aversions to the EtOH-paired flavors. Results of those manipulations indicated that an ethanol aversion was established in the water-deprived animals. Those results indicated that water-deprived animals of Experiment 1B reversed their EtOH-paired flavor preference when the caloric need associated with food deprivation conditions was eliminated. Since deprivational state determined the development of EtOH preferences, the present results indicate that caloric need may play an initial role in establishing conditioned preferences for EtOH.

Alcohol Drinking

Human bites of the eyelid.

Five patients with traumatic colobomas of the eyelid secondary to human bites were surgically repaired with retrieved autogenous tissue. All patients were treated with prophylactic intravenous antibiotics. Surgical repair consisted of debridement of the autograft, meticulous layered closure of the autograft to the wound, and placement of a lid margin suture. In two of the patients, mild upper eyelid retraction was noted, and two patients had loss of cilia.

Adult

The motivation to use drugs: a psychobiological analysis of urges.

Traditionally, theories of addiction have stressed that drug urges are characterized by dysphoria, occur in response to decreasing levels of drug or drug effect, and are associated with withdrawal symptoms/signs or drug-antagonistic responses arising from a homeostatic mechanism. However, recent research has shown that urges, drug self-administration, and relapse all occur concomitant with both positive and negative affect, rising and falling levels of drug, and with drug-agonistic responses, as well as antagonistic/withdrawal responses. In keeping with recent theorizing about motivation and emotions, we believe that affective responding provides a readout of the motivational status of an organism (e.g., Buck, 1985). We conceive of urges as affects, whose activation mediates drug pursuit and self-administration. Moreover, we believe that affects are represented in neural networks comprising information on affect-relevant stimuli, responses, and meaning/expectancy. We believe that there are two types of urge networks. One, a "positive-affect" network, is activated, associatively and nonassociatively, by appetitive stimuli, especially appetitive drug actions that activate "GO" motivational incentive systems. Activation of this network is characterized by positive affect, drug isodirectional responding, attentional focus on a dominant response, and enhanced pursuit of appetitive stimuli--especially the drug. The operating characteristics of the positive-affect network, and the associated motivational systems, result in a drug's instating a positive feedback loop. Appetitive drug actions increase the likelihood of the pursuit of appetitive stimuli, and additional drug constitutes a prepotent candidate from among the available appetitive stimuli. This positive feedback loop may account in part for cardinal features of addiction: for example, the great relapse likelihood once any drug is sampled, the attainment of very high blood levels of a drug, and the pursuit of adjunctive appetitive stimuli while using a drug. The second type of urge network we have labeled a "negative-affect" network, and we believe it is activated, associatively and nonassociatively, by inappetitive stimuli or consequences (punishment, signals of punishment, frustrating lack of reward, etc.) and by withdrawal and signals of withdrawal (e.g., drug cues, which during the course of addiction are associated with both direct drug effects and withdrawal). Activation of the network is characterized by withdrawal symptoms and signs, negative affect, and drug seeking.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Psychological

Some effects of response-independent reinforcement on auditory generalization gradients.

Two groups of six rats received discrimination training with two auditory stimuli differing in intensity. During one stimulus, the schedule was variable interval; during the other, it was either variable time or extinction. Both the variable time and extinction schedules resulted in differential rates of responding in the presence of the two stimuli. Extinction resulted in an earlier and more stable difference. Stimulus generalization gradients obtained along the noise-intensity dimension revealed peak shift with both procedures. In addition, a secondary peak to stimuli in between the two training stimuli occurred with the variable-time schedule.

Acoustic Stimulation