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Biomedical subjects

D M Lyons

Publications and source records attributed to D M Lyons.

At least 37 records · Page 2Linked to original sources
PubMed1996

Strategic resource management.

No one in healthcare can challenge the fact that expense reduction is and will continue to be one of the primary concerns of the industry. Everyone also knows that these cost pressures are merely beginning. All indications point to a future environment of intense competition, managed care based on cost-per-covered-life reimbursement, reduced reimbursement from Medicare and Medicaid, and further reconfiguration of the industry to shift patients from in- to out-patient settings. When we focus on the future, the $64,000 question is: "What is the healthcare industry doing to control non-labor expenses, and who is responsible for this ambitious undertaking within each hospital or network?" With nearly 30% of every hospital dollar consumed by non-labor expenses, are current efforts adequate to meet future demands? This article focuses on a strategic plan for reducing non-labor expenses.

Contract Services↗
PubMed1995

Social effects and circadian rhythms in squirrel monkey pituitary-adrenal activity.

Simultaneous measures of plasma cortisol and ACTH were collected at the morning peak (AM) and evening nadir (PM) of the circadian rhythm in group-housed and individually housed squirrel monkeys (Saimiri sciureus). Pronounced AM-PM differences in cortisol were evident in both conditions, but morning measures of cortisol in monkeys housed without companions were 32% higher than baseline control values observed when the same monkeys were sampled in groups. Consistent AM-PM differences in cortisol were not associated with consistent AM-PM differences in ACTH, and for monkeys housed without companions, plasma ACTH concentrations were consistently and significantly reduced (23% lower in the morning, 42% lower in the evening). All monkeys were subsequently pretreated overnight when dexamethasone to temporarily suppress the secretion of endogenous ACTH and then challenged the following morning with a bolus injection of synthetic ACTH. Monkeys housed without companions responded to the challenge with greater, more prolonged elevations in cortisol relative to monkeys housed in groups. These observations together suggest that squirrel monkeys housed without companions hypersecrete cortisol at the morning peak of the rhythm because adrenal responsiveness to ACTH is enhanced. Low circulating ACTH levels in turn are maintained by robust glucocorticoid feedback mechanisms that inhibit the synthesis or release of pituitary ACTH.

Adrenocorticotropic Hormone↗
PubMed1994

Ste5 tethers multiple protein kinases in the MAP kinase cascade required for mating in S. cerevisiae.

Ste5 is a Zn2+ finger-like protein thought to function before three kinases, Ste11 (a MEKK), Ste7 (a MEK), and Fus3 (a MAPK), in a conserved MAP kinase cascade required for mating in S. cerevisiae. Here, we present evidence that Ste5 forms a multikinase complex that joins these kinases for efficient Fus3 activation. By two-hybrid analysis, Ste11, Ste7, and Fus3 associate with different domains of Ste5, while Kss1, another MAPK, associates with the same domain as Fus3, thus implying that Ste5 simultaneously binds a MEKK, MEK, and MAPK. Ste5 copurifies with Ste11, Fus3, and a hypophosphorylated form of Ste7, and all four proteins cosediment in a glycerol gradient as if in a large complex. Ste5 also increases the amount of Ste11 complexed to Ste7 and Fus3 and is required for Ste11 to function. These results substantiate a novel signal transduction component that physically links multiple kinases within a single cascade.

Adaptor Proteins, Signal Transducing↗
PubMed1994

Socioregulatory effects on squirrel monkey pituitary-adrenal activity: a longitudinal analysis of cortisol and ACTH.

Squirrel monkeys show unusually prolonged elevations in plasma cortisol when separated from like-sex social companions. To determine whether this hypersecretion of cortisol reflects a deficiency in feedback mechanisms that normally inhibit the prolonged activation of the pituitary-adrenal axis, we simultaneously measured plasma cortisol and corticotropin (ACTH) in 30 juvenile monkeys housed in established groups, individual cages, and newly formed groups. As found in recent longitudinal studies of adults, when juveniles were living without companions, mean cortisol titers were consistently higher than those observed when the same juveniles were living in like-sex social groups. When cortisol was elevated, however, ACTH titers were significantly and chronically reduced. These results suggest that elevated cortisol does inhibit ACTH synthesis or release, and that hypercortisolism in squirrel monkeys living without companions is not a consequence of chronic elevations in ACTH. Similar peculiarities in pituitary-adrenal activity are evident in a number of affective disorders in human beings.

Adrenocorticotropic Hormone↗
PubMed1993

Social grouping tendencies and separation-induced distress in juvenile sheep and goats.

Social affinities in juvenile sheep and goats were compared by measuring grouping tendencies and separation-induced distress during experimental encounters with a person in either the presence or the absence of juvenile pen-mates. When tested with pen-mates, sheep spent more time near penmates than did goats. When separated from pen-mates, locomotor activity and plasma corticosteroid titers were higher in sheep, whereas vocal rates were higher in goats. Proximity to pen-mate scores were not correlated with either vocal rates, r = 0.20, or locomotion scores, r = 0.21, recorded when juveniles were tested alone. Proximity to pen-mate scores were correlated with posttest corticosteroid titers, r = 0.70; juvenile sheep spent more time near pen-mates and showed greater adrenocortical responses when temporarily separated from juvenile pen-mates. These findings support the possibility that interspecies differences in emotional reactivity contribute to the differences in grouping tendencies these ungulates display in natural or relatively unrestricted social groups.

Analysis of Variance↗
PubMed1992

Sexual segregation in squirrel monkeys (Saimiri sciureus): a transactional analysis of adult social dynamics.

Female agonism against males and male interventions in social transactions between the sexes are 2 explanations for the low rates of social engagement observed between male and female squirrel monkeys (Saimiri sciureus). These possibilities were evaluated by comparing the frequency, structure, and content of transactions between the sexes in 3 experimental social units: male-female pairs, single-male-multifemale groups, and multimale-multifemale groups. Affiliative transactions between the sexes occurred 3-5 times less often in multimale-multifemale groups than in male-female pairs and in single-male-multifemale groups. Intermale agonism in the multimale-multifemale groups often coincided with ongoing transactions between the sexes, whereas female agonism against males was rather uncommon in all social units. The results failed to support the female agonism hypothesis and indicate a need for more detailed studies of intermale social dynamics.

Agonistic Behavior↗
PubMed1992

Making the purchase decision: factors other than price.

Taking price out of the limelight and concentrating on customer relations, mutual respect, and build-in/buy-in; involving the user; developing communication and evaluation processes; and being process oriented to attain the results needed require commitment on the part of administration and materiel management. There must be a commitment of time to develop the process, commitment of resources to work through the process, and a commitment of support to enhance the process. With those three parameters in place, price will no longer be the only factor in the purchasing decision.

Communication↗
PubMed1988

Social modulation of pituitary-adrenal responsiveness and individual differences in behavior of young domestic goats.

The effects of three variables known to influence pituitary-adrenal activity were examined in kid goats who were accompanied by adult goats in standard goat-human encounters. Serum corticosteroid concentrations in bold kids who characteristically spent above average amounts of time closely interacting with the person were never significantly different from control values. Corticosteroids in timid kids who spent little time near the person depended on the adult goat's behavior toward the person and the nature of the social relationship between the kid and the adult goat. When timid kids were accompanied by adult goats (familiar pen-mates or strangers) who behaved as if they were fearful of the person, their corticosteroids were significantly greater than control values. In contrast, bold pen-mates or bold strangers effectively reduced pituitary-adrenal responsiveness in timid kids. Only mothers unconditionally reduced kid pituitary-adrenal responsiveness and systematically affected kid behavior toward the person. The functioning of behavioral and pituitary-adrenal systems in young goats was influenced by consistent individual differences in responsiveness and the differing capacities of social companions to modulate this responsivity.

Adrenal Cortex Hormones↗
PubMed1986

Solubilization of the iron molybdenum cofactor of Azotobacter vinelandii nitrogenase in dimethylformamide and acetonitrile.

The iron molybdenum cofactor of Azotobacter vinelandii nitrogenase has been solubilized for the first time in dimethylformamide and acetonitrile. These solutions have the ability to reconstitute the inactive nitrogenase of the UW 45 mutant of A. vinelandii and exhibit an S = 3/2 EPR signal similar to that for the cofactor in N-methylformamide. Our ability to obtain solutions of FeMoco in these solvents seemingly refutes a previous hypothesis concerning the necessity of solvents with a dissociable proton for iron molybdenum cofactor solubility and should facilitate the spectroscopic characterization of this important species.

Acetonitriles↗
PubMed1986

Blue toe syndrome.

Blue toe syndrome is easily misdiagnosed because the cyanotic mottling resembles localized bruising from minor foot trauma. Clinicians who think of circulatory problems are sometimes led astray because the patient looks healthy and presents with excellent peripheral pulses. Appropriate laboratory studies can lead to a correct diagnosis. Endarterectomy or graft replacement of the diseased arterial segment is usually the preferred treatment.

Aorta, Abdominal↗
PubMed1982

Ultrasounds in neonatal rats: novel, predator and conspecific odor cues.

Neonatal rat ultrasound repetition rates were monitored in response to 6 odor cues, including 1 novel, 2 predator, and 3 conspecific olfactory stimuli. Contrary to predictions of previous studies, predator odor did not elicit consistently low call rates. A significant difference was detected between litters tested with the same odor cue for the foreign and predator odor treatments. Odor was the only significant effect to explain differences in neonatal ultrasonic responses to conspecific odor treatments. Call rates recorded for the novel lactating female odor were significantly greater than those for the home bedding and adult male odors. Odors associated with the home cage or with an adult male elicited low call rates.

Animals↗
PubMedDate not supplied

Glucocorticoid and mineralocorticoid receptor mRNA expression in squirrel monkey brain.

Corticosteroids have been implicated in hippocampal atrophy in patients with severe psychiatric disorders, but little is known about receptor expression for corticosteroids in human or nonhuman primate brain. Both the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) were surveyed in this study of squirrel monkey brain using in situ hybridization histochemistry. Regions of high GR mRNA levels included CA1 and CA2 of hippocampus, dentate gyrus, paraventricular hypothalamus, lateral geniculate, lateral>medial amygdala, and cerebellum. Western analysis confirmed that GR immunoreactivity in squirrel monkey brain tissue most likely reflects the alpha isoform. Regions of high MR mRNA levels included all hippocampal pyramidal cell fields, dentate gyrus granule cell layer, lateral septum, medial>lateral amygdala, and to a lesser extent, cerebellum. Low levels of MR were also expressed in caudate and putamen. Receptor expression for corticosteroids in deep brain structures and the hippocampal formation was similar to that previously reported in rodents, but GR and MR mRNA were expressed at higher levels in squirrel monkey cerebral cortex. GR expression was evident in all cortical layers, particularly the pyramidal cell-rich layers II/III and V. MR expression was restricted to the more superficial cortical layers, and was only moderately represented in layer V. Laminar patterns were apparent in all regions of cortex for GR expression in squirrel monkeys, but low MR mRNA levels were found in dorsomedial prefrontal cortex (PFC). Different subregional distributions and distinctive laminar patterns suggest specialized functions or coordinated interactions between GR and MR mediated functions in primate PFC.

Animals↗