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PubMed1976

[Effects of short time extreme hemodilution with and without hypothermia on hemodynamic and biochemical parameters in the pig (author's transl)].

Extreme hemodilution as "Total Body Washout" (TBW) is a feasible method for the clinical therapy of endo- or exogenous intoxication. This method was modified for a simple and quick setup. Landrace pigs were hemodiluted with a special heart-lung-machine. Within 4 minutes the hematocrit was lowered to less than 1%. The rectal temperature fell hereby in a normothermic group (n = 15) to 35, 1 +/- 1, 1 degrees C and in a hypothermic one (n = 13) to 31,1 +/- 1,3 degrees C. The TBW was followed by a total exchange transfusion. Most of the parameters that were studied did not show significant differences between cold and warm perfusion. The proceeding was well tolerated by the animals, they were observed up to 6 weeks. Disadvantages of initial surface cooling may be avoided by extreme hemodilution with exclusive extracorporal cooling, when cardiac arrest in hypothermia is intended.

Animals↗
PubMed2003

Melanin-concentrating hormone is a critical mediator of the leptin-deficient phenotype.

Energy homeostasis is regulated by a complex network involving peripheral and central signals that determine food intake and energy expenditure. Melanin-concentrating hormone (MCH) plays an essential role in this process. Animals treated with MCH develop hyperphagia and obesity. Ablation of the prepro-MCH gene leads to a lean phenotype, as does ablation of the rodent MCH receptor, MCHR-1. MCH is overexpressed in the leptin-deficient ob/ob mouse, and we hypothesized that ablation of MCH in this animal would lead to attenuation of its obese phenotype. Compared with ob/ob animals, mice lacking both leptin and MCH (double null) had a dramatic reduction in body fat. Surprisingly, the hyperphagia of the ob/ob mouse was unaffected. Instead, leanness was secondary to a marked increase in energy expenditure resulting from both increased resting energy expenditure and locomotor activity. Furthermore, double-null mice showed improvements in other parameters impaired in ob/ob mice. Compared with ob/ob mice, double-null animals had increased basal body temperature, improved response to cold exposure, lower plasma glucocorticoid levels, improved glucose tolerance, and reduced expression of stearoyl-CoA desaturase 1 (SCD-1). These results highlight the importance of MCH in integration of energy homeostasis downstream of leptin and, in particular, the role of MCH in regulation of energy expenditure.

Adipose Tissue, Brown↗
PubMed1998

Dynamics of stress-related decrease of salivary immunoglobulin A (sIgA): relationship to symptoms of the common cold and studying behavior.

The dynamics of stress-related decrease of salivary Immunoglobulin A (sIgA) were examined with respect to whether an increase of upper respiratory tract (URT) symptoms can be observed concurrently with or subsequent to sIgA alterations and whether one can use students' studying behavior during academic examinations to predict changes in sIgA. From a 2-part medical examination of 42 students, daily measures of sIgA were obtained, and symptoms of URT infections and studying behavior were determined by means of questionnaires. Assessment periods began 7 days before each part of the academic examination began and lasted until the 6th day afterward. A control group of 24 medical students who were not undergoing examinations also responded to all questionnaires. A progressive suppression of sIgA, outlasting the examination period by more than 6 days, was observed. Time spent studying explained a significant proportion in sIgA variation. However, no relationship between sIgA and URT symptoms was observed, nor did students who took academic examinations differ from untested controls in symptom rates.

Achievement↗
PubMed1996

Modification of the cardiovascular effects of ephedrine by the reversible monoamine oxidase A-inhibitor moclobemide.

Irreversible, nonselective monoamine oxidase (MAO) inhibitors have been reported adversely to interact with indirectly acting sympathomimetic amines present in many cough and cold medicines. This study investigated the safety and tolerability of concomitant administration to 12 healthy subjects of both genders (aged 19-36 years) of ephedrine and moclobemide, a reversible MAO-A inhibitor. A 2-day, randomized, crossover administration of placebo or ephedrine (two doses of 50 mg with a 4-h interval) was followed by 9 days open-label dosing with moclobemide, 300 mg b.i.d.. On the last 2 days of moclobemide dosing, the randomized crossover treatment of ephedrine and placebo was repeated. No subject was withdrawn from the study for tolerability reasons. Moclobemide treatment, however, increased the incidence of adverse events elicited by ephedrine, particularly palpitations and headache. The pharmacodynamic interaction between the two drugs was quantified by calculation of the area under the effect-time course (AUE) for systolic (SBP) and diastolic blood pressure (DBP) and heart rate (HR). The difference in AUE between monotreatment with ephedrine and placebo was statistically significant for all three vital signs. Moclobemide potentiated the effect of ephedrine by a median factor of 3.2 for SBP, 3.8 for DBP, and 0.6 for HR. Ephedrine had no significant influence on the plasma concentrations of moclobemide or its metabolites. In conclusion, the combined use of moclobemide and high doses of sympathomimetic drugs should be approached with caution.

Adrenergic Agents↗
PubMed2002

Performance enhancement with maintenance of resting immune status after intensified cycle training.

BACKGROUND: Unaccustomed intense endurance exercise is associated with short-term suppression of natural immunity. However, it is not established whether intensified endurance training alters resting immune status or increases the risk of upper respiratory infection (URI). PURPOSE: This study examined the effect of intensified endurance training for performance enhancement on resting immune status in nine healthy, male competitive cyclists. DESIGN: Data were collected during 4 weeks of usual training (baseline), followed by prescribed cycle training that consisted of volume-building at customary training intensity (V phase, 6 weeks), unaccustomed very high intensity interval training at 100% maximal heart rate (I phase, 18 days), and an unloading taper (U phase, 10 days). METHODS: The main performance criterion was a simulated 20 km time-trial. Aerobic capacity measures included power output at ventilatory threshold (POT(vent)) and maximal oxygen uptake (VO(2max)). Markers of immune status (lymphocyte subset counts, serum cytokine levels, and new URI cases) and physiological indicators of training stress (cycling economy, 24-hour urinary cortisol excretion, and serum testosterone concentration) were evaluated in the rested state, 36 to 44 hours postexercise, during baseline, and after each training phase. RESULTS: Time-trial performance, POT9(vent), VO(2max), and cycling economy improved significantly (p < 0.001) after the V phase, and remained higher than baseline (p < 0.001) after the I and U phases. As compared with the V phase, performance time was faster after the U phase (p < 0.01). In contrast, lymphocyte counts, cytokine levels, incidence of URI, cortisol excretion, and serum testosterone concentration were not significantly different from baseline in any phase. CONCLUSIONS: Cycling efficiency and performance improved while resting immune status was maintained throughout the 10-week training program. This study provides encouraging data in support of immunological robustness during intensified endurance training.

Adult↗
PubMed2002

The combined effect of drought stress and heat shock on gene expression in tobacco.

In nature, plants encounter a combination of environmental conditions that may include stresses such as drought or heat shock. Although drought and heat shock have been extensively studied, little is known about how their combination affect plants. We used cDNA arrays, coupled with physiological measurements, to study the effect of drought and heat shock on tobacco (Nicotiana tabacum) plants. A combination of drought and heat shock resulted in the closure of stomata, suppression of photosynthesis, enhancement of respiration, and increased leaf temperature. Some transcripts induced during drought, e.g. those encoding dehydrin, catalase, and glycolate oxidase, and some transcripts induced during heat shock, e.g. thioredoxin peroxidase, and ascorbate peroxidase, were suppressed during a combination of drought and heat shock. In contrast, the expression of other transcripts, including alternative oxidase, glutathione peroxidase, phenylalanine ammonia lyase, pathogenesis-related proteins, a WRKY transcription factor, and an ethylene response transcriptional co-activator, was specifically induced during a combination of drought and heat shock. Photosynthetic genes were suppressed, whereas transcripts encoding some glycolysis and pentose phosphate pathway enzymes were induced, suggesting the utilization of sugars through these pathways during stress. Our results demonstrate that the response of plants to a combination of drought and heat shock, similar to the conditions in many natural environments, is different from the response of plants to each of these stresses applied individually, as typically tested in the laboratory. This response was also different from the response of plants to other stresses such as cold, salt, or pathogen attack. Therefore, improving stress tolerance of plants and crops may require a reevaluation, taking into account the effect of multiple stresses on plant metabolism and defense.

Adaptation, Physiological↗
PubMed2006

Sequence analysis of the lactococcal plasmid pNP40: a mobile replicon for coping with environmental hazards.

The conjugative lactococcal plasmid pNP40, identified in Lactococcus lactis subsp. diacetylactis DRC3, possesses a potent complement of bacteriophage resistance systems, which has stimulated its application as a fitness-improving, food-grade genetic element for industrial starter cultures. The complete sequence of this plasmid allowed the mapping of previously known functions including replication, conjugation, bacteriocin resistance, heavy metal tolerance, and bacteriophage resistance. In addition, functions for cold shock adaptation and DNA damage repair were identified, further confirming pNP40's contribution to environmental stress protection. A plasmid cointegration event appears to have been part of the evolution of pNP40, resulting in a "stockpiling" of bacteriophage resistance systems.

Adaptation, Physiological↗
PubMed1995

Pain and pain tolerance in professional ballet dancers.

Pain experience in sport had been the subject of increasing research in recent years. While sports professionals have generally been found to have higher pain thresholds than control subjects the reasons for this are not entirely clear. The present study seeks to investigate one possible explanatory factor, the importance of the popular image of the physical activity and of the self-image of its participants, by examining pain experience in professional ballet dancers. Like sports professionals, dancers were found to have higher pain and pain tolerance thresholds than age matched controls in the Cold Pressor Test. However, they also reported a more acute experience of the sensory aspects of the pain. Explanations of this apparent paradox are discussed both in terms of the neuroticism scores of the two groups and in terms of the dancers' greater experience of pain and its relationship with physical activity. The results illustrated the importance of using multidimensional measures of pain in this type of investigation.

Adolescent↗
PubMed1996

Oxidative stress and antioxidants in overwintering larvae of cold-hardy goldenrod gall insects

Antioxidant and pro-oxidant systems were studied in overwintering larvae of two cold-hardy gall insect species, the freeze-tolerant fly Eurosta solidaginis and the freeze-avoiding moth Epiblema scudderiana. An increase in the levels of the oxidized form of glutathione suggested slight oxidative stress in both species during the winter. Freeze-tolerant Eurosta solidaginis larvae generally had decreased activities of antioxidant enzymes in the winter, indicating that these larvae do not face increased challenge from oxidative stress during the numerous freeze-thaw events they experience. Instead, existing defences must be sufficient to prevent any damage. By contrast, increased winter activities of antioxidant enzymes in freeze-avoiding Epiblema scudderiana suggest that these larvae must defend against the formation of reactive oxygen species. This may result from the oxidative nature of winter metabolism in these larvae, as well as a dependence on lipid oxidation as their fuel over this season. Xanthine dehydrogenase activity decreased dramatically in both species during the autumn, reducing the potential for the formation of the pro-oxidant xanthine oxidase. Indeed, xanthine oxidase activity fell to undetectable levels by winter in Epiblema scudderiana and was not detectable at any time in Eurosta solidaginis.

Journal Article↗
PubMed2006

Cold exposure and exercise metabolism.

Research regarding the effect of cold exposure on metabolism and substrate utilisation during exercise has produced inconsistent results. Intensity of exercise and training status of subjects are known to impact metabolism and substrate utilisation regardless of environmental conditions. Duration and intensity of cold exposure during exercise also may exert impact. Thus, systematic manipulation of these variables (fitness, intensity of exercise, cold conditions) should provide a means to determine metabolic and substrate utilisation patterns when exercising in the cold. However, a number of variables have been introduced into research methodologies that may confound results. Duration and intensity of cold exposure prior to exercise, and acclimation and clothing status of subjects may confound or override the influence of other variables. Future research addressing the impact of cold exposure on metabolism and substrate utilisation during exercise must attempt to isolate and control each influential factor (prior to and during exercise), and must be alert to the interactive effects that can occur.

Adaptation, Physiological↗
PubMed2004

Effects of smoking, distraction, and gender on pain perception.

Whereas research on the antinociceptive effects of cigarette smoking has produced inconsistent findings, certain aspects of attentional processing repeatedly have been found to have an impact on pain perception. In an effort to delineate the relation between smoking and pain, the present study tested the attentional mediation model of smoking in pain perception. The authors hypothesized that by narrowing attentional focus, smoking in the presence of a distractor would facilitate distraction from painful stimuli, producing the most pronounced antinociceptive effect, compared with smoking or distraction alone. On the basis of previous findings of gender differences in pain, the authors hypothesized that the effects would vary by gender. The authors used the cold pressor test to assess pain threshold and tolerance in 76 smokers. A 2 (smoking/not smoking) x 2 (distraction/no distraction) x 2 (male/female) between-subjects analysis of variance (ANOVA) yielded Distraction x Gender interactions for pain threshold and pain tolerance. Pain sensitivity was lower in the distraction condition for men only. Whereas the results did not support the attentional mediation model of smoking in pain perception, they highlight the importance of distraction and gender differences in experimental pain.

Adolescent↗
PubMed1981

Comparison of autoimmunity induction with virulent and attenuated rinderpest virus in rabbits.

Two strains of rinderpest virus which differ each other in virulence to rabbits were compared in their capacity to produce autoantibodies and their effects on the function of the lymphoid system. The virulent L strain induced two autoantibodies, i.e., antinuclear antibody (ANA) and cold hemagglutinating antibody (HA), and suppressed lymphocyte response to phytohemagglutinin and to concanavalin A for at least 4 weeks after infection. The attenuated LA strain, on the other hand, failed to induce the autoantibodies except transient production of cold HA in few animals, although persistent production of virus-neutralizing antibody like that in L strain infection was observed. The suppression of lymphocyte responses to mitogens was limited to a period of 3--7 days after infection. Possible mechanism of the virus-induced autoimmunity was discussed in relation to the immunosuppressive effect of virus infection.

Animals↗
PubMedDate not supplied

A comparison of new nonsedating and classical antihistamines in the treatment of primary acquired cold urticaria (ACU).

The efficacy of the new nonsedating antihistamines loratadine and cetirizine was compared in a randomized, single-blind, crossover, controlled study with that of the classical antihistamines cyproheptadine and ketotifen in seven patients with primary acquired cold urticaria (ACU). The patients received each of the four drugs for 14 consecutive days with a 7-day interval between drugs. We evaluated clinical symptomatology, adverse effects, minimum time of cold contact stimulation required to induce an immediate coalescent wheal (CSTT), and inhibition of histamine-induced wheal response. Both loratadine and cetirizine showed suppression of symptoms with infrequent adverse effects. Important side-effects were observed in patients receiving cyproheptadine. Improvement in CSTT was statistically significant for all drugs compared with baseline values, without differences among them. The histamine-induced skin test was significantly inhibited by all antihistamines. Wheal reductions were 34.6% for loratadine and 50.9% for cetirizine. This study suggests that both loratadine and cetirizine may be effective in the treatment of primary ACU.

Adult↗
PubMed1986

[Intravenous sotalol in the acute treatment of supraventricular tachycardias].

The effects of intravenous sotalol (0.5 mg/kg in 6 minutes) were studied in 23 patients with supraventricular tachycardia (ventricular rate greater than 120 bpm) after failure of placebo (isotonic dextrose). Thirteen patients had atrial flutter or fibrillation and 10 a junctional tachycardia of recent onset. Sinus rhythm was restored in 4 of the patients with atrial flutter or fibrillation and the ventricular rate was slowed significantly in 3 patients (less than 100 bpm). In 3 other patients the ventricular rate decreased (31 to 35 p. 100) but remained above 100 bpm. Sinus rhythm was restored in 3 of the 10 patients with a junctional tachycardia five to twelve minutes after beginning the injection. A slight slowing of the heart rate (13 to 27 p. 100) was observed in the other 7 patients but the frequency remained over 100 bpm. Overall, a satisfactory result was obtained in 10 patients (43 p. 100) including 7 cases in which sinus rhythm was restored. Sotalol was well tolerated in 21 patients; one patient complained of cold in the legs and one patient developed asymptomatic bradycardia (46 bpm). This study shows that intravenous sotalol may be useful in the emergency treatment of supraventricular tachycardia.

Adolescent↗
PubMed1979

[The antiallergic effect of Balkis. A rhino-manometric study].

The antiallergic and decongestive effects of the common cold preparation Balkis was tested by rhinomanometry in human volunteers usually suffering from allergic rhinitis after oral treatment. The nasal irritation in these patients was induced by administration of the specific allergen. This kind of test is especially appropriate for the control of drugs in cases of ordinary colds, as the test conditions are reproducible in symptomatically similar cases. The rhinomanometrical control of the respiratory resistance was carried out before and after an allergenic exposal as well as before and after administration of Balkis and allergenic exposal in 30 patients (17 females, 13 males; 9-49 years old). It is shown that Balkis had a good to satisfactory antiallergic effect in 67% of all cases. In 33% of the cases the antiallergic effect was not evident. This result confirms objectively the good antiallergic effect of this common cold preparation by oral administration. Balkis was well tolerated in all of the 30 patients. The symptoms of slight fatigue which appeared in 1/3 of all cases were only transitory.

Chlorpheniramine↗