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PubMed1983

Interacting effects of information and coping style in adapting to gynecologic stress: should the doctor tell all?

This study explored the interacting effects of personal dispositions and situational conditions on the stress response. Forty gynecologic patients about to undergo a diagnostic procedure (colposcopy) were divided into information seekers (monitors) and information avoiders (blunters). Half in each group were exposed to voluminous preparatory information, and half to the usual low level of information. Subjective, physiological, and behavioral measures of arousal and discomfort were obtained before, during, and after the procedure. Overall, low-information patients expressed less subjective arousal than high-information patients, and blunters showed less subjective and behavioral arousal than monitors. In addition, patients' level of psychophysiological arousal was lower when the level of preparatory information was consistent with their coping style; that is, blunters were less aroused with low information and monitors were less aroused with high information. Further evidence was gained for the utility and validity of a new scale for identifying monitors and blunters.

Adaptation, Psychological↗
PubMed1991

Interactive effects of ethanol and caffeine on rat fetal hepatocyte replication and EGF receptor expression.

This study reports on the interactive effects of ethanol and caffeine on growth of rat fetal hepatocytes. Exposure of cultured rat fetal hepatocytes (RFH) to ethanol in concentrations above 1 mg/ml, causes a blockade of EGF-dependent cell replication along with an overexpression of surface EGF receptors (EGF-R). However, RFHs exposed for 24 hours to ethanol at a concentration of 1 mg/ml alone had little effect on cell replication. Caffeine, when combined with this concentration of alcohol, progressively impaired RFH growth by up to 100%. Caffeine alone up to 10 micrograms/ml, on the other hand, caused a progressive increase in RFH replication associated with a 69% enhancement of DNA synthesis. Caffeine concentrations in excess of 50 micrograms/ml had no effect on replicative capacity. Concomitant caffeine exposure had no effect on the ethanol-related increase in cell DNA content, yet it caused a further enhancement of the cell protein accural induced by ethanol alone. Caffeine (10 micrograms/ml) alone had no effect on EGF-R expression, while ethanol (2 mg/ml) increased it by almost 200%. Addition of caffeine to ethanol reduced this enhanced EGF binding by 45%. Scatchard analysis indicated that no treatment altered ligand affinity for the receptor, but that the alterations in binding caused by ethanol and the caffeine/ethanol combination reflected changes in binding capacity, in both low and high affinity components. It is concluded that (1) ethanol blocks EGF-mediated replication accompanied by a reduction in DNA synthesis, (2) caffeine alone at low concentrations has the opposite effect and can actually potentiate the EGF-mediated mitogenic response, (3) caffeine in combination with ethanol acts synergistically to reduce RFH replication.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Interactive effects of salt concentration and temperature on growth and lipid composition in the moderately halophilic bacterium Vibrio costicola.

The interactive effects of NaCl concentration and growth temperature on the growth and lipid composition of the moderately halophilic eubacterium Vibrio costicola have been investigated. Vibrio costicola was shown to be capable of growth over the temperature range 4-37 degrees C. Maximum growth yields were obtained at 30 degrees C when the optimum NaCl concentration was 1.0 M NaCl. In contrast with some previous studies, at higher or lower growth temperatures both the optimum and lower limit of NaCl concentration were higher, but there was no change in the upper limit of NaCl concentration for growth. There were no differences between the lipid compositions of cultures grown in 1 M NaCl at 30 or 37 degrees C, but as the growth temperature was lowered from 30 to 10 or 4 degrees C, the ratio of phosphatidylethanolamine to phosphatidylglycerol increased significantly as a result of the conversion of phosphatidylglycerol to diphosphatidylglycerol; in addition, at the lower growth temperatures the phospholipid fatty acyl composition became more unsaturated and the mean acyl chain length was shorter. It is suggested that the altered salt dependence of V. costicola at temperatures below the optimum for growth is due to a modification in membrane lipid phase behavior and stability brought about by changes in lipid composition, whereas a different mechanism operates above the growth temperature optimum.

Food Microbiology↗
PubMed1996

Interactive effects of denervation and malnutrition on diaphragm structure and function.

The purpose of this study was to examine the interactive effects of unilateral denervation (DN) and prolonged malnutrition (MN) on the structure and function of the diaphragm muscle (Dia). Four groups of rats were studied: control (Con), MN, DN, and DN-MN. MN began 2 wk after DN and lasted 4 wk. In both the DN and DN-MN groups, the relative loss in Dia weight exceeded the relative change in body weight. Compared with the Con group, Dia specific force was reduced by approximately 40% in both the DN and DN-MN groups but was unaffected in the MN group. Dia fatigue resistance improved in all experimental groups but to a greater extent in the DN and DN-MN groups. In both the DN and DN-MN groups, approximately 50% of Dia fibers were classified as type IIc, whereas fiber type proportions did not change in the MN group. In the DN group, only type IIb/x fibers atrophied, whereas all fiber types atrophied in the MN and DN-MN groups. We conclude that in the DN-MN group the reduction in specific force combined with the reduction in total cross-sectional area of the muscle significantly curtails Dia force-generating capacity.

Animal Nutritional Physiological Phenomena↗
PubMed1995

The direct and interactive effects of phosphodiesterase inhibition and beta-adrenergic stimulation on myocyte contractile function after hypothermic cardioplegic arrest.

The direct and interactive effects of phosphodiesterase inhibition (PDEI) and beta-adrenergic receptor (beta AR) stimulation on isolated myocyte contractile function were examined after hypothermic, hyperkalemic, cardioplegic arrest (HHCA) and under normothermic conditions. Left ventricular (LV) myocytes were isolated from porcine hearts and myocyte contractile function was measured under normothermic conditions (37 degrees C in standard media) and after HHCA (2 h at 4 degrees C in Ringer's solution with 24 mEq KCl) with subsequent rewarming. Myocytes were then randomly assigned to treatment with the beta AR agonist isoproterenol (25 nM), the phosphodiesterase inhibitor amrinone (50 microM), or a combination of these compounds and contractile function measurements repeated. Baseline myocyte contractile function was reduced by 32% after HHCA. Isoproternol alone increased myocyte contractile function more than 100% under both normothermic conditions and after HHCA, whereas amrinone alone significantly (60%) improved myocyte contractile function only after HHCA. Amrinone preincubation followed by isoproterenol improved contractile function after HHCA to a greater extent than all other treatment protocols. In contrast, combination treatment under normothermic conditions did not augment myocyte contractile function relative to isoproterenol alone. These findings suggest that amrinone has differential effects on contractile processes. Moreover, the marked improvement of contractile function after HHCA with PDEI pretreatment followed by beta AR stimulation may have implications in treatment strategies for improving myocardial function after cardiopulmonary bypass and provide insight into contractile dysfunction after HHCA.

Adrenergic beta-Agonists↗
PubMed1979

Interactive effects of resistance and facilitation patterning upon reaction and response times.

The purpose of this study was to determine the interactive effects of maximum resistance with proprioceptive neuromuscular facilitation patterning upon reaction, movement, and response time. Reaction time, response time-one (flexion at shoulder, extension at elbow), response time-two (flexion, adduction, external rotation at shoulder, elbow flexion), and movement time (response time-two minus reaction time) were measured before and after a training program. Fifty subjects were randomly assigned to one of the following training groups: weight training, proprioceptive neuromuscular facilitation patterning without resistance, and proprioceptive neuromuscular facilitation with maximum resistance. Subjects participated in their training sessions three times a week for six weeks. Analysis revealed no significant changes between the training groups.

Adult↗
PubMed1992

Interactive effects of solutes, potassium sorbate and incubation temperature on growth, heat resistance and tolerance to freezing of Zygosaccharomyces rouxii.

The interactive effects of solutes, potassium sorbate and incubation temperature on growth, heat resistance and tolerance to freezing of Zygosaccharomyces rouxii were investigated. Growth rates in media supplemented with glucose, sucrose or NaCl to aw 0.93 were more rapid than in unsupplemented media (aw 0.99). Although growth in unsupplemented medium was lower at 35 degrees C, incubation at 21 degrees C or 35 degrees C had little effect on growth in media supplemented with glucose and sucrose. The addition of 300 micrograms potassium sorbate/ml to media resulted in reduced growth rates, particularly at 35 degrees C. Heat resistance of Z. rouxii was substantially greater in cultures previously incubated at 35 degrees C than in cultures incubated at 21 degrees C in media both with and without 300 micrograms potassium sorbate/ml. Zygosaccharomyces rouxii was tolerant to freezing at -18 degrees C for up to 120 d in all test media supplemented with glucose, sucrose or NaCl. The addition of 300 micrograms potassium sorbate/ml to sucrose-supplemented media resulted in increased resistance to freezing in cultures previously incubated at 21 degrees C. Sensitivity to freezing increased when cultures were incubated at 21 degrees C in media not supplemented with solutes. Glucose and sucrose provided the best protection against inactivation by heating and freezing, regardless of the presence of potassium sorbate in growth media.

Adaptation, Biological↗
PubMed1989

Interactive effects of anemia and muscle oxidative capacity on exercise endurance.

We used endurance training and acute anemia to assess the interactions among maximal oxygen consumption (VO2max), muscle oxidative capacity, and exercise endurance in rats. Animals were evaluated under four conditions: untrained and endurance-trained with each group subdivided into anemic (animals with reduced hemoglobin concentrations) and control (animals with unchanged hemoglobin concentrations). Anemia was induced by isovolemic plasma exchange transfusion. Hemoglobin concentration and hematocrit were decreased by 38 and 41%, respectively. Whole body VO2max was decreased by 18% by anemia regardless of training condition. Anemia significantly reduced endurance by 78% in untrained rats but only 39% in trained animals. Endurance training resulted in a 10% increase in VO2max, a 75% increase in the distance run to exhaustion, and 35, 45, and 58% increases in skeletal muscle pyruvate-malate, alpha-ketoglutarate, and palmitylcarnitine oxidase activities, respectively. We conclude that endurance is related to the interactive effects of whole body VO2max and muscle oxidative capacities for the following reasons: 1) anemic untrained and trained animals had similar VO2max but trained rats had higher muscle oxidative capacities and greater endurance; 2) regardless of training status, the effect of acute anemia was to decrease VO2max and endurance; and 3) trained anemic rats had lower VO2max but had greater muscle oxidative capacity and greater endurance than untrained controls.

Anemia↗
PubMed1993

Interactive effects of musical and visual cues on time perception: an application to waiting lines in banks.

This study explores the interactive effects of musical and visual cues on time perception in a specific situation, that of waiting in a bank. Videotapes are employed to stimulate the situation; a 2 x 3 factorial design (N = 427) is used: 2 (high vs low) amounts of visual information and 2 (fast vs slow) levels of musical tempo in addition to a no-music condition. Two mediating variables are tested in the relation between the independent variables (musical and visual ones) and the dependent variable (perceived waiting time), mood and attention. Results of multivariate analysis of variance and a system of simultaneous equations show that musical cues and visual cues have no symmetrical effects: the musical tempo has a global (moderating) effect on the whole structure of the relations between dependent, independent, and mediating variables but has no direct influence on time perception. The visual cues affect time perception, the significance of which depends on musical tempo. Also, the "Resource Allocation Model of Time Estimation" predicts the attention-time relation better than Ornstein's "storage-size theory." Mood state serves as a substitute for time information with slow music, but its effects are cancelled with fast music.

Adult↗
PubMed1990

Interactive effects of etching and pre-oxidation on porcelain adherence to non-precious alloys: a guided planar shear test study.

Interactive effects of etching and pre-oxidation on porcelain adherence to non-precious alloys were studied by a guided planar shear bond test under non-cantilever conditions. The results indicated that electrolytic etching decreases bond strength, but that oxidation of etched surfaces restores the bond strength level. The results are explained by a hypothesis that depletion of critical elemental species occurs during etching. Potential replenishment of the lost elements during subsequent oxidation, although not confirmed, may assist in improving bond strength.

Acid Etching, Dental↗
PubMed1994

Interactive effects of dietary copper and water copper level on growth, water intake, and plasma and liver copper concentrations of poults.

The interactive effects of dietary Cu and water Cu on poult growth, water intake, whole-blood hemoglobin (Hb), and plasma and liver Cu concentrations were investigated using 232-9-old toms. Poults were randomly assigned to two levels of dietary Cu [Basal (B) and B + 204 mg Cu/kg diet] and to four levels of water Cu (0, 51.5, 103, and 206 mg Cu/kg water) in a 2 x 4 factorial arrangement of treatments. Each treatment was replicated six times. All poults received tap water during Days 1 to 5 followed by the water Cu treatments during Days 6 to 10. Water intake was measured daily and gain and feed intake were determined on Days 5 and 10. Day 1 to 5 gain was reduced (P < .02) in poults fed supplemental dietary Cu. Day 1 to 5 feed intake and gain:feed and Day 6 to 10 gain, feed intake, gain:feed, and water intake were not affected (P > .10) by dietary Cu.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Interactive effects involving different classes of excitatory amino acid receptors and the survival of cerebellar granule cells in culture.

Differentiating granule cells develop survival requirements in culture which can be met by treatment with high K+ or N-methyl-D-aspartate (NMDA) and, according to our recent findings, also with low concentrations of kainic acid (KA, 50 microM). We have now attempted to elucidate the mechanism(s) underlying the trophic effect of KA. KA rescue of cells was completely suppressed by blockers of voltage-sensitive calcium channels, such as nifedipine in low concentrations (5 x 10(-7) M), indicating that the promotion of cell survival is mediated through the activation of these channels by membrane depolarization. Thus the trophic influences of KA and NMDA share a common mechanism, increased Ca2+ influx (albeit through different routes), a conclusion that is supported by the observation that the effects of these agonists at concentrations causing maximal promotion of cell survival were not additive. Interactive effects involving different classes of excitatory amino acid receptors were revealed by the potentiation of the KA rescue of cells by the NMDA receptor antagonists, 2-amino 5-phosphonovalerate (APV) or (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohept-5,10-imine hydrogen maleate (MK-801), which on their own failed to promote, but rather reduced cell survival. The potentiation of the KA effect by the competitive NMDA antagonist APV was counteracted by the weak NMDA agonist, quinolinic acid. These observations suggest that KA alone has both trophic and toxic effects, the latter being mediated secondarily through an NMDA-like glutamate receptor, which is distinct from the conventional NMDA, KA and quisqualate preferring subtypes.

Amino Acids↗
PubMedDate not supplied

Interactive effects of prenatal cocaine and nicotine exposure on maternal toxicity, postnatal development and behavior in the rat.

Two experiments were performed to investigate the interactive effects of prenatal coadministration of cocaine hydrochloride (C) and nicotine tartrate (N). Experiment I was designed to determine doses of C and N that could be coadministered without altering maternal gestational parameters and/or fetal viability. Exposure of Sprague-Dawley rats to combined high-dose C (20 mg/kg) and high-dose N (5.0 mg/kg) on gestation days 8-21 was not more toxic to dam or fetus that that of exposure to C alone. Experiment II investigated pregnancy outcome, postnatal development, and behavior of the offspring following drug exposure to either high-dose cocaine (20 mg/kg: CS), high-dose nicotine (5.0 mg/kg: NS), or both (NC) on gestation days 8-21. N was administered by osmotic minipump and C by sc injection. Saline-injected dams, fitted with saline-fitted pumps (SS), and untreated dams, pair-fed (PF) to NC females, served as controls. Alterations in maternal variables were limited to a 10-15% decrease in food consumption in NC and CS groups. Pregnancy outcome and birth statistics were unaffected by prenatal treatment, as was offspring body weight during the first four postnatal weeks. However, the development of surface righting was delayed inC CS pups, and only CS offspring were underresponsive to the stimulatory effects of dopamine agonists on activity and stereotypy. Behavioral responses to N challenge were similar in all groups. In addition, only CS offspring showed altered behavioral responses in a spontaneous alternation task. Treatment effects on dopamine D1 and D2 binding in the caudate nucleus were not observed. The combination of N and C did not exacerbate any of the behavioral changes seen in CS offspring. These results support the hypothesis that C is a behavioral teratogen in rodents, and suggest that in the present model, nicotine can mitigate some of the consequences of in utero exposure to cocaine.

Aging↗
PubMed1995

Acute interactive effects of MK-801 and morphine on cortical EEG and EEG power spectra in rats.

The interaction between MK-801 and morphine-induced effects on cortical electroencephalography (EEG) was investigated. Rats were administered one of five MK-801 doses (IP) prior to morphine (IV). MK-801 dose-dependently increased morphine-induced global spectral power, duration of morphine-induced EEG bursts and latency to sleep onset, and decreased morphine-induced mean frequency, mobility, complexity, and edge frequency. MK-801 pretreatment shifted the relative distribution of total power to the left. Significant interaction effects were found for all spectral parameters except peak frequency. A second group of rats was administered MK-801 prior to an increasing cumulative morphine dose. MK-801 increased maximal morphine effects on all spectral parameters except peak frequency. The results are in agreement with those of recent analgesia and in vitro studies in spinal neurons, and support observations of a synergistic interaction between effects of NMDA antagonism and morphine. These data further suggest that the component of cortical EEG that is produced by mu-opioid- and NMDA-receptor interactive effects may be dominated by an inhibitory effect of morphine on NMDA receptor activity.

Animals↗
PubMed1993

Research note: interactive effects of sodium zeolite A and Eimeria acervulina infection on growth and tissue minerals in chicks.

Two experiments were conducted to assess the interactive effects of dietary sodium zeolite A (SZA) and experimental Eimeria acervulina infection on growth and tissue mineral concentrations in chicks. The average initial weight of the chicks was 71.8 g, and the experimental periods were from 5 to 15 days posthatching. In both experiments, the corn-soybean meal basal diet was supplemented with 0 or .75% SZA and fed to uninfected chicks or to chicks infected with 4 x 10(5) sporulated E. acervulina oocysts on Days 0, 3, and 6 of the experiments. Both coccidial infection and SZA reduced (P < .05) gain and feed intake; however, feed efficiency was reduced (P < .01) only in the coccidiosis-infected chicks. Neither SZA nor the coccidial infection affected (P > .10) plasma Ca or P, tibia P, liver Ca, Zn, Fe, or Mn, or pancreas Cu. Sodium zeolite A increased (P < .05) plasma Zn but only in uninfected chicks (SZA by coccidiosis, P < .10). The coccidial infection decreased (P < .02) tibia ash percentage. Sodium zeolite A decreased tibia Ca in uninfected chicks but increased tibia Ca in coccidiosis-infected chicks (SZA by coccidiosis, P < .10). The coccidial infection increased (P < .05) tibia Mg, Cu, Fe, Pb, Mn, and Al concentrations. Dietary SZA also increased (P < .02) tibia Zn, Mn, and Al concentrations. The coccidial infection decreased (P < .02) tibia Zn concentration, and SZA decreased (P < .05) tibia Mg and Fe. Sodium zeolite A by coccidiosis interactions (P < .10) were evident in tibia Zn, Fe, Mn, and Al concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Interactive effects of volatile anesthetics, verapamil, and ryanodine on contractility and calcium homeostasis of isolated pregnant rat myometrium.

OBJECTIVE: Both volatile anesthetics and Ca2+ antagonists decrease uterine contractility. The interactive effects of anesthetics, verapamil, and ryanodine on myometrial muscular activity and on intracellular Ca2+ availability were examined. STUDY DESIGN: The effects of minimum alveolar concentrations of 0.5, 1.0, and 2.0 of halothane, enflurane, and isoflurane on electrically stimulated isometric mechanical activity of isolated longitudinal myometrium strips from 45 pregnant rats (15 to 21 days), superfused with Krebs' solution with or without 5.0 mmol/L Ca2+, 10(-7) and 10(-6) mol/L verapamil, and 10(-6) mol/L ryanodine, were compared. Analysis was performed by analysis of variance and Duncan test. RESULTS: All three anesthetics and verapamil produced dose-dependent depression of contractility. Increasing the Ca2+ concentration from 2.5 to 5.0 mmol/L in the superfusate partly reversed the depression. An additive effect of verapamil and anesthetics, especially enflurane, on contractile force was observed. Ryanodine had no effect on contractility, but it could partly counteract the depressant effect of anesthetics. CONCLUSION: Clinically used concentrations of volatile anesthetics modify Ca2+ availability and depress uterine contractility. General anesthesia, especially by enflurane, in patients being treated with calcium antagonists may represent a higher risk.

Anesthetics↗
PubMed1997

Interactive effects of dietary chromium tripicolinate and crude protein level in growing-finishing pigs provided inadequate and adequate pen space.

An experiment was conduct to determine the interactive effects of dietary chromium tripicolinate (CrPic), CP, and pen space (PS) as a stress on growth performance, carcass traits, and plasma hormones and metabolites of crossbred growing-finishing pigs (128 pigs; initial BW 27.2 kg). A factorial arrangement of treatments included two levels of Cr (0 and 400 ppb as CrPic), two levels of CP (80 [80P] and 120% [120P] of the lysine requirement; NRC, 1988), and two levels of PS (adequate [APS] or inadequate [IPS]). In the grower phase, ADG was decreased more by IPS when pigs were fed 80P (CP x PS, P < .08). Gain/feed (G/F) was decreased by IPS in pigs fed 80P; however, in pigs fed 120P, IPS increased G/F (CP x PS, P < .01). Supplemental Cr did not affect (P > .10) ADG, ADFI, or G/F in the grower phase. In the finisher phase, pigs, fed 120P had less (P < .10) ADFI but similar (P > .10) ADG compared with pigs fed 80P. Gain/feed was higher (P < .10) in pigs fed 120P than in pigs fed 80P. Daily gain ADFI were lower (P < .03) in pigs provided IPS than in pigs provided APS. In pigs fed 80P, CrPic tended to result in higher ADG and G/F; however, in pigs fed 120P, Cr tended to result in lower ADG and G/F (CP x Cr, P < .09). Pigs fed 120P had greater (P < .03) longissimus muscle area (LMA) and percentage of muscling (PM) and less (P < .03) 10th rib fat thickness (TRF) than pigs fed 80P. Pigs provided IPS had greater LMA and PM and less TRF than pigs provided APS (P < .03). Pigs fed CrPic had higher TRF when provided IPS but lower TRF when provided APS (Cr x PS, P < .07). Feeding CrPic had minimal effect on plasma urea N, cholesterol, glucose, NEFA, insulin, or growth hormone.

Analysis of Variance↗
PubMed1994

Interactive effects among porcine somatotropin, the beta-adrenergic agonist salbutamol, and dietary lysine on growth performance and nitrogen balance of finishing swine.

An experiment was conducted to evaluate the interactive effects among porcine somatotropin (pST), salbutamol, and dietary lysine on growth performance, nitrogen balance, and carcass characteristics of finishing barrows (n = 32; 62.8 kg initially). Two replicate 32-d studies were set up in a split-plot design to evaluate singular and combined use of pST (0 or 4 mg/d) and salbutamol (0 or 2.75 ppm of the diet) as whole-plot treatments and diets containing .8, 1.2, 1.6, or 2.0% lysine as subplot treatments. Dietary lysine levels were administered within subplots in a 4 x 4 Latin square with pigs allowed 4 d of adjustment to diets followed by 4 d of urine and feces collection for determination of N retention and apparent digestibility of DM and N. Interactions between lysine and salbutamol were not found (P > .16). A pST x lysine interaction (P < .05) resulted in ADG being maximized at 1.2% lysine for pST-treated pigs (lysine quadratic, P < .02) but decreased linearly (P < .02) with increasing lysine for pigs receiving buffer. Pigs injected with 4 mg/d of pST had improved gain:feed (G:F) up to 1.2% lysine (lysine quadratic, P < .05), but no further increase to 2% lysine, whereas pigs injected with buffer showed no benefit from increased lysine (pST x lysine, P < .06). Pigs receiving buffer had greater increases in plasma urea N (PUN) as lysine increased than those receiving pST (pST x lysine, P < .002), but PUN was reduced by pST (P < .001) regardless of lysine level.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗