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Biomedical subjects

M G King

Publications and source records attributed to M G King.

At least 19 recordsLinked to original sources
PubMed2000

Conditioning rhinitis in allergic humans.

A classical Pavlovian paradigm pairing an olfactory cue with allergen challenge for a single training trial was used to produce conditioned histamine release and conditioned nasal airflow decrease in seasonal allergic rhinitis sufferers. There was no conditioned increase in subjective symptoms. Histamine release and airflow decrease showed evidence of extinction by a second test trial. A second study comparing the effects of the number of training trials showed that three training trials produced greater histamine release and airflow decrease than a single training trial, suggesting stronger effects with additional training.

Humans↗
PubMed1999

"God brought all these churches together": issues in developing religion-health partnerships in an Appalachian community.

This study explored health-related and organizational religious activities in an Appalachian community and identified cultural issues in the development of religion-health partnerships. Partnerships between religious groups and health providers are a channel for health promotion efforts to vulnerable populations and must be approached from the culture of the community. An ethnographic, exploratory study of health-related and organizational activities in nonmainline religious groups yielded the use of prayer requests, anointing, testimonial, and denominational links as potential health resources. Organizational decisions were by congregational consensus and theological interpretation. The communal setting of worship as an informal resource to a community of believers, especially the vulnerable, was a viable model for religion-health partnerships in central Appalachia. Implications for nursing practice, education, and research also are addressed.

Appalachian Region↗
PubMed1997

The effects of lipopolysaccharide (LPS) on the fever response in rats at different ambient temperatures.

There is a complex interplay between the immune system, nervous system, and sleep. When an organism is challenged with lipopolysacchride (LPS), the immune system is stimulated, producing a fever response that is independent of ambient temperature, and an increase in slow-wave sleep (SWS). The study investigated sleep patterns of immune-challenged rats during the light phase cycle to determine the effects of various ambient temperatures. It was hypothesised that fever response would occur independently of ambient temperatures. Also, the febrile response would be monophasic, and there would be an increase in slow-wave sleep (SWS) and a decrease in rapid-eye-movement (REM) sleep. Thirty Wistar rats were randomly placed in 3 different ambient temperature groups, 22 degrees C, 15 degrees C, and 30 degrees C. Within each of these conditions, the same subjects served as control and experimental groups. Four animals were placed in 4 subsections of 2 standard boxes that were placed in the ambient-temperature box. The electrodes were connected to the analog to digital computer board, where all the data was processed and stored on a hard drive. The animals were injected I.P. with saline and recorded for a period of 6 h to establish a baseline. On Day 2, the same animals were injected I.P. with LPS and recorded for 6 h to determine the febrile effects of LPS on the immune system; the same procedure was repeated in the other ambient temperatures. The results have shown that animals experienced a monophasic fever response in low and normal temperatures, but not in the high temperatures. Although there was no increase in SWS, there was a significant decrease in REM sleep in 3 groups.

Animals↗
PubMed1995

Behavioral conditioning of lipopolysaccharide-induced anorexia.

One manifestation of the acute phase response, sickness behavior, is now considered an important response in the organism's overall attempt to reinstate homeostasis. This report aimed to determine whether the sickness behavior of anorexia was conditionable using the conditioned taste aversion paradigm. To investigate this phenomenon, lipopolysaccharide (LPS) (100 micrograms/kg) was used as the unconditioned stimulus, and was paired with a novel 1% saccharin solution (conditioned stimulus). Upon conditioned stimulus representation, the anorectic effects of LPS were observed. These data are consistent with recent literature showing acute phase events to be conditionable.

Animals↗
PubMed1995

Modification of body temperature and sleep state using behavioral conditioning.

Previous research has demonstrated the conditionability of events within the acute-phase response. This study examined whether two such responses, fever and sleep alterations, were conditionable in the rat during the dark photoperiod. The experimental animals were administered a novel saccharin solution as the conditioned stimulus (CS) in conjunction with lipopolysaccharide as the unconditioned stimulus (UCS). This group displayed significantly higher body temperatures than controls upon saccharin representation, 7 days after the original CS-UCS pairing. The experimental animals additionally displayed a conditioned increase in slow wave sleep (SWS); however, the LPS-induced reduction in rapid eye movement (REM) sleep was unable to be reenlisted. Similar to the acute-response, the conditioned alteration in SWS appeared to be due to an increase in episode frequency, rather than duration. These results suggest that the multiple acute-phase events may be simultaneously conditionable, producing an optimum environment for pathogen elimination.

Acute-Phase Reaction↗
PubMed1995

Behaviorally conditioned anorexia: role of gastric emptying and prostaglandins.

The reduction of food intake in response to bacteria is posited to be a favourable host reaction. This report attempted to examine whether gastric emptying is involved in the known conditionability of this response. Additionally, this study investigated the role of prostaglandins in the conditioned anorexic response. To investigate this phenomenon, lipopolysaccharide (LPS) (100 micrograms/kg) was used as the unconditioned stimulus, and paired with a novel 1% saccharin solution (conditioned stimulus). Upon conditioned stimulus (CS) representation, experimental animals displayed a marked reduction in food consumption (experiment 1) and emptying of gastric contents (experiment 2). Additionally, treatment with indomethacin upon CS reexposition blocked both the conditioned anorexia and suppression of gastric emptying. These results indicate that conditioned anorexia is possibly the result of a conditioned inhibition of gastric emptying, and this process is mediated by conditioned alterations in PG levels.

Animals↗
PubMed1995

Behavioral conditioning of endotoxin-induced plasma iron alterations.

The cascade of physiologic mechanisms in response to infection, the acute-phase response, is recognized as playing a major role in host defence. One such response is the hypoferremia that is consistently reported to occur during bacterial infection. This study aimed to determine whether the alterations in plasma iron were conditionable using the conditioned taste aversion (CTA) paradigm. The regime involved the pairing of a novel-tasting saccharin solution with bacterial endotoxin. Seven days after the initial pairing of these stimuli (the test day), the saccharin solution was represented. Animals exposed to this condition displayed a significant reduction in the level of plasma iron. Animals treated with an intraperitoneal dose of 400 micrograms/Kg lipopolysaccharide (LPS) displayed lower conditioned iron levels than rats infused with 100 micrograms/Kg LPS; however, this difference was not significant. These results showed that in addition to other acute-phase responses (fever and anorexia), plasma iron alterations are able to be manipulated through behavioral manipulations.

Animals↗
PubMed1995

Paradoxical conditioning of the plasma copper and corticosterone responses to bacterial endotoxin.

The cascade of physiologic mechanisms in response to infection, the acute phase response, is recognized as having a major role in host defense. Two such responses are an increase in plasma copper and activation of the hypothalamic-pituitary-adrenal axis, which are consistently reported to occur during bacterial infection. We aimed to determine whether the alterations in plasma copper and corticosterone were conditionable using the conditioned taste aversion paradigm. The regime involved the pairing of a novel-tasting saccharine solution (the conditioned stimulus) with lipopolysaccharide (the unconditioned stimulus). Seven days after the initial pairing of these stimuli (the test day), the saccharine solution was represented. Animals exposed to this condition displayed a significant decrease in plasma copper levels. In addition, these rats experienced a reduction in plasma corticosterone that was time dependent. Paradoxically, the conditioned response of both these variables were in a direction contrary to that reported during bacterial infection. These results suggest that some acute phase responses may condition as a rebound response, or in an opposing trend to that occurring as the initial reaction.

Acute-Phase Reaction↗
PubMed1994

Pavlovian conditioning of nasal tryptase release in human subjects with allergic rhinitis.

The role of Pavlovian conditioning in humans with perennial allergic rhinitis was investigated using release of tryptase from sensitised mast cells as an indicator of allergic responsiveness. Challenge with house dust mite allergen (unconditioned stimulus) was paired with a drink of novel taste and appearance (conditioned stimulus) in a single conditioning trial. Upon reexposure to the conditioned stimulus alone, levels of mast cell tryptase released in subjects who had received both the novel drink and allergen challenge on the conditioning trial was significantly greater than subjects who had received either the drink or the allergen alone. The results support the involvement of the central nervous system in mast cell degranulation in allergic rhinitis in humans.

Adult↗
PubMed1994

Inhibition of endotoxin-induced temperature change by behavioral conditioning using alpha-melanocyte-stimulating hormone as an unconditioned stimulus.

The experiments reported here investigate the conditionability, using taste aversion conditioning, of the antagonistic effects of alpha-MSH on the thermoregulatory changes associated with injection of bacterial endotoxin lipopolysaccharide (LPS) in rats. Animals were administered LPS and then given alpha-MSH, as an unconditioned stimulus (UCS), in association with the novel taste of saccharin, the conditioned stimulus (CS). The temperature response at this time in alpha-MSH-treated rats was similar to that observed in control animals. However, 7 days later, when these animals were again injected with LPS but re-exposed to saccharin alone, there was a significant reduction in the temperature response profile compared to controls. These results demonstrate that in male rats the conditioned antipyretic effect following conditioning with alpha-MSH as the UCS is sufficiently robust to counteract the acute effects on body temperature of an LPS injection at the time of CS reexposure. This complements previous experiments demonstrating that thermoregulation may be influenced by cognitive association.

Animals↗
PubMed1993

Melanin pigments and melanosomal proteins as differentiation markers unique to normal and neoplastic melanocytes.

This report introduces some aspects of our current basic research focus on the unique metabolic pathways within the melanocyte. Using this approach, we hope to gain a better understanding of the pathophysiology of malignant melanoma and develop early laboratory diagnostic tests for this disease. Specifically, we will discuss that: 1) the synthesis of pheomelanin is markedly increased in malignant melanoma and dysplastic melanocytic nevi; 2) high levels of metabolites of pheomelanin and eumelanin can be detected in the urine and blood of patients with metastatic melanoma; 3) this release of melanin metabolites appears to correlate with tumor thickness and tumor load, including the extent of metastasis; 4) the synthesis of melanosomal proteins also becomes aberrant in malignant melanoma; and 5) this abnormal melanosome synthesis can be utilized in the identification of antigenic epitopes that are uniquely expressed in malignant melanoma. We believe that this synthesis and secretion of abnormal melanin pigment and melanosomal proteins (human melanosome-specific antigen) would be useful for the development of early laboratory diagnostic and monitoring tools for malignant melanoma. In addition, we also report the detection of pheomelanin component in "normal" unexposed skin; however, the relative amount of pheomelanin in the skin does not reflect hair color (e.g., red hair). The nature of this pheomelanin component in the skin needs to be further clarified.

Animals↗
PubMed1992

Sleep deprivation-induced hyperthermia following antigen challenge due to opioid but not interleukin-1 involvement.

Eight hours total sleep deprivation does not affect colonic temperature. The combination of a subpyrogenic challenge of sheep red blood cells with sleep loss however, can produce a significant rise in colonic temperature that peaks during the third hour of the sleep deprivation vigil. The regulation of this increase in colonic temperature appears to be opioid in nature and not because of the release of the cytokine interleukin-1. It would appear that the combination of sleep loss and low dose antigen challenge, both manipulations of themselves nonpyrogenic, produces a synergistic rise in colonic temperature. The implication of a psychologically-derived stress response via the opioid system may explain this finding.

Animals↗
PubMed1992

Lithium chloride and immunomodulation in taste aversion conditioning.

Lithium chloride has been used in many studies of conditioning to induce taste aversion behaviour, and in some experiments investigating conditioning effects on immunity it has been used on the assumption that it is immunologically neutral. The studies reported here, however, indicate that LiCl is not immunologically neutral and when used to endow a UCS with noxious properties to enhance the behavioural response in taste aversion conditioned immunosuppression, it may antagonize the residual immunosuppression following initial UCS administration and also the conditioned immunosuppression occurring after CS reexposure. Therefore, conclusions drawn from studies of behaviourally conditioned immunomodulation where LiCl is used as part of either the CS or UCS may require reevaluation.

Animals↗
PubMed1991

Effect of paraformaldehyde fixation on localization and characterization of insulin-like growth factor-I (IGF-I) receptors in the rat brain.

In order to design an approach for localizing IGF-I receptors within the intact CNS, the effect of paraformaldehyde (PAF) fixation on receptor binding was examined. Cryostat sections of rat brains, which were perfused with 0 to 10% PAF, were incubated in 125I-IGF-I and assayed for binding under equilibrium conditions. Binding was quantified from 10 brain regions, involving laminae and nuclei from median eminence, thalamus, hippocampus, choroid plexus, pyriform cortex, and cerebral cortex, by computer densitometry of film autoradiographs. The specific binding, saturation curves, Bmax and Ka, ligand specificity, and binding reversibility of IGF-I binding sites were not significantly affected by 1% or 2% PAF. However, 4% PAF elevated IGF-I receptor total binding, nonspecific binding, and Ka, and decreased Bmax, presumably by increasing the number of tissue-receptor interconnections. Only nonspecific 125I-IGF-I binding persisted when 10% PAF was used. These results indicate that tissue perfused with 2% PAF can be used for localizing IGF-I receptors by autoradiographic binding methods.

Animals↗
PubMed1991

Modulation of body temperature through taste aversion conditioning.

Injection of rats with bacterial lipopolysaccharide (LPS) results in an initial fall in body temperature followed by a fever. Lithium chloride (LiCl) injection induces a fall in body temperature without subsequent fever production. When these substances were incorporated as unconditioned stimuli in a taste aversion conditioning paradigm, using saccharin flavour as the conditioning stimulus, these differential effects on body temperature were reenlisted on reexposure to saccharin alone 7 days after conditioning. The changes in body temperature on reexposure were similar in direction and kinetics as on the conditioning day although reduced in magnitude. The finding of a true conditioned effect in these studies is in contrast to the paradoxical or compensatory conditioned body temperature responses described elsewhere using different conditioning models. This apparent conflict may be explained on the basis of different unconditioned stimuli acting on efferent versus afferent arms of a negative feedback system. Since body temperature changes often occur in association with immune responses, these findings may have implications to behavioural conditioning of immunity, the outcome of which may reflect the indirect effects on immunity of inadvertent conditioning of thermoregulatory changes.

Animals↗