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Biomedical subjects

J E Sherman

Publications and source records attributed to J E Sherman.

At least 37 records · Page 2Linked to original sources
PubMed1986

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↗
PubMed1986

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↗
PubMed1986

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↗
PubMed1984

Morphine analgesia: enhancement by shock-associated cues.

Recent research has shown that rats exposed to repeated stress display enhanced morphine analgesia. This study examined the possible contribution of classically conditioned analgesia to this effect. First, drug-naive rats exposed to nine daily sessions of stress, each consisting of a single 45-s exposure to footshock, subsequently displayed enhanced analgesic responsiveness to morphine 1 and 10 days after stress (Experiments 1, 2, and 5). This enhancement was also observed in morphine-experienced rats 1 and 8 days after stress (Experiment 1). Second, the effect of footshock stress on morphine analgesia was found to be specific to the environment in which stress was administered (Experiments 2 and 3). Rats tested in the same distinctive environment in which stress was administered displayed enhanced morphine analgesia; rats shocked elsewhere did not differ from nonshocked controls (Experiment 2). Third, conditioned analgesia was found under the same conditions that yielded enhanced morphine analgesia (Experiments 2 and 4). Lastly, both this conditioned analgesia and the acute analgesia elicited by the footshock stressor were found to be attenuated by naloxone (Experiments 5 and 6). These data are consistent with the hypothesis that the enhanced morphine analgesia observed after repeated footshock stress reflects the contribution of an opioid mediated , conditioned analgesia elicited by cues formerly paired with the stressor.

Animals↗
PubMed1984

Coverage of the calvarium with a free parascapular flap.

The reconstructive problems associated with providing durable coverage for full-thickness loss of the scalp are detailed and the options reviewed. Free tissue transfer offers a break-through in these difficult problems. A case of a successful parascapular flap transfer is described, offering an alternative to previously described methods.

Adult↗
PubMed1983

Prediction of skin viability following en bloc resection for osteogenic sarcoma with fluorescein.

Intravenous fluorescein dye was applied as a test of skin viability in 11 en bloc resections for osteogenic sarcoma about the knee. Intravenous fluorescein dye is an easy, safe, efficient, and inexpensive method that helps to predict the viability of surgically created skin flaps. When patchy fluorescence is observed, primary debridement is recommended to prevent immediately postoperative skin necrosis. This test proved to be an accurate, significant indicator of nonviable skin, in both location and dimension. All flaps that were patchy by the fluorescein test consisted of nonviable skin. Conversely, flaps that took up the dye evenly went on to uneventful wound healing. The fluorescein test should be considered for further application in orthopedic surgical procedures when skin viability is uncertain, e.g., in cases of trauma and complicated reconstructions about the knee and elbow.

Bone Neoplasms↗
PubMed1983

The opioid/nonopioid nature of stress-induced analgesia and learned helplessness.

Exposure to a variety of stressors produces a subsequent analgesic reaction. This stress-induced analgesia (SIA) is sometimes opioid in nature (reversed by opiate antagonists and cross-tolerant with morphine) and sometimes nonopioid. Both 30 min of intermittent footshock and 60-80 five-sec tailshocks have been shown to produce opioid SIA, whereas 3 min of continuous footshock and 5-40 tailshocks produce nonopioid SIA. We report that both of the opioid SIA procedures produce a learned helplessness effect as assessed by shuttlebox escape acquisition and an analgesia that is reinstatable 24 hr. later. The nonopioid procedures produce neither a learned helplessness effect nor a reinstatable analgesia. It is argued that these data implicate the learning of uncontrollability in the activation of opioid systems.

Analgesia↗
PubMed1982

Adrenal medullary enkephalin-like peptides may mediate opioid stress analgesia.

Different patterns of fact shock activate opioid and nonopioid mechanisms of stress analgesia in the rat. Opioid, but not nonopioid, stress analgesia is reduced by adrenal demedullation and denervation and is potentiated by reserpine, a drug known to increase concentrations of adrenal medullary enkephalin-like peptides. It is suggested that adrenal enkephalins mediate opioid stress analgesia.

Adrenal Medulla↗
PubMed1982

Prior hot plate exposure enhances morphine analgesia in tolerant and drug-naive rats.

The associative model of morphine tolerance predicts that established tolerance should be attenuated, i.e., extinguished, by placebo injections in the former morphine injection environment. The present study examined the effect of placebo sessions, with and without accompanying nociceptive stimulation, on the extinction of analgesic tolerance. In Experiment 1, rats rendered tolerant to morphine displayed recovery of morphine's analgesic action only following placebo sessions including exposure to a painful hot plate surface (52.5 degrees C); placebo sessions on a cool plate (23-24 degrees C) failed to attenuate tolerance even though these placebo sessions more closely matched the stimulus conditions of tolerance acquisition. In Experiment 2, repeated hot plate exposures were similarly found to enhance morphine analgesia in drug-naive rats. These results question an extinction account of the effect of hot plate placebo sessions observed in Experiment 1. Instead, they suggest that nociceptive hot plate exposures, per se, are sufficient to enhance subsequent morphine analgesia.

Animals↗
PubMed1982

Neural and neurochemical mechanisms of pain inhibition.

Recent studies which suggest the existence of an endogenous neural substrate of pain inhibition are reviewed. Electrical stimulation of some areas of the medial brain stem in laboratory rats has produced a dramatic degree of analgesia. Such stimulation-produced analgesia is partially blocked by an opiate antagonist drug. This observation has proved seminal to those searching for endogenous opiate-like neurochemicals, the opioid peptides (enkephalins and endorphins). Particular attention is focused on studies of stimulation-produced analgesia, the underlying anatomy and physiology of endogenous analgesia systems elucidated by such work, and the relation of these findings to discoveries about opiate receptors and opioid peptides. Very recent work suggesting that certain forms of stress are natural triggers for activating endogenous analgesia mechanisms is described. Although certain stressors cause analgesia mediated by opioids, other stressors cause analgesia by neurochemically different means. Thus, multiple analgesia substrates, opioid and nonopioid, appear to exist.

Analgesia↗
PubMed1981

Neurofibromas of the breast and nipple-areolar area.

Neurofibromas are common tumors that arise from elements in the peripheral nervous system. The vast majority occur in the trunk and are usually limited to the head and neck area. We present two cases involving the skin of the breast and nipple-areolar complex and the method of treatment.

Adult↗
PubMed1981

Aversion to the reinforcer differentially affects conditioned reinforcement and instrumental responding.

Rats were trained to press a bar for sucrose solution delivered by a dipper; they then received pairings of sucrose and lithium chloride (LiCl) in the home cage and were tested for bar pressing. In the first and second experiments, the conditioned aversion to sucrose had no effect on unreinforced bar pressing in the test, but the aversion reduced bar pressing reinforced either by sucrose or by the operation of the empty dipper. In the third and fourth experiments, presses during training were reinforced by sucrose only in the presence of an audiovisual discriminative stimulus; in the test, the aversion to sucrose reduced pressing reinforced by the discriminative stimulus, but the aversion had no effect on unreinforced pressing in either the presence or the absence of the discriminative stimulus. Thus, pairings of sucrose and LiCl reduced the reinforcing value of sucrose and also of a stimulus previously paired with sucrose, but they had no effect of an instrumental response previously reinforced by sucrose or on the discriminative properties of a stimulus paired with sucrose.

Animals↗
PubMed1981

Opioid and non-opioid stress analgesia: assessment of tolerance and cross-tolerance with morphine.

Opioid and non-opioid mechanisms of analgesia elicited by two kinds of footshock stress that differ only in temporal characteristics previously have been inferred on the basis of susceptibility to naloxone blockade. The present study sought further evidence on this point by comparing these two kinds of footshock analgesia for possible tolerance development and cross-tolerance with morphine. It was found that, with repeated exposure to stress, tolerance developed to naloxone-sensitive, but not naloxone-insensitive, stress analgesia. Furthermore, morphine-tolerant rats displayed cross-tolerance to only the naloxone-sensitive form of footshock analgesia. Although prior exposure to both footshock paradigms potentiated morphine analgesia, less potentiation occurred in rats tolerant to the naloxone-sensitive footshock stress. Thus, cross-tolerance between morphine and this type of stress analgesia appears to occur in both directions. These findings are consistent with those using naloxone antagonism as a criterion for opioid mediation and support the conclusion that separate opioid and non-opioid mechanisms of stress analgesia exist.

Analgesia↗
PubMed1981

The use of cross-leg flap in malignancy: realization of a potential complication.

We present a case of recurrent myxoid fibrosarcoma presumed to have spread to the contralateral leg by means of cross-leg flap procedure. In the era of free flap transfer, musculocutaneous flaps and the recent cross-leg musculocutaneous flap, the cross-leg flap remains a valuable technique for the reconstructive plastic surgeon. However, it should not be considered in reconstruction after resection of a malignant tumor.

Biopsy↗