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PubMed1975

Intestinal infusion of endotoxin in adrenalectomized calves.

Four adrenalectomized calves, 3 to 4 months old, were allowed to develop adrenocorticosteroid insufficiency and then were given 50 mg of Escherichia coli endotoxin by infusion via cannula into the duodenum. Several physiologic variables were studied to detect changes indicative of endotoxemia. It is concluded that adrenocorticosteroid insufficiency in calves is not an independent factor allowing an intestinal source of endotoxin to cause the development of clinical signs and physiologic changes characteristic of endotoxemia.

Adrenal Cortex Hormones↗

PubMed2002

Multiscale entropy to distinguish physiologic and synthetic RR time series.

We address the challenge of distinguishing physiologic interbeat interval time series from those generated by synthetic algorithms via a newly developed multiscale entropy method. Traditional measures of time series complexity only quantify the degree of regularity on a single time scale. However, many physiologic variables, such as heart rate, fluctuate in a very complex manner and present correlations over multiple time scales. We have proposed a new method to calculate multiscale entropy from complex signals. In order to distinguish between physiologic and synthetic time series, we first applied the method to a learning set of RR time series derived from healthy subjects. We empirically established selected criteria characterizing the entropy dependence on scale factor for these datasets. We then applied this algorithm to the CinC 2002 test datasets. Using only the multiscale entropy method, we correctly classified 48 of 50 (96%) time series. In combination with Fourier spectral analysis, we correctly classified all time series.

Adult↗

PubMed1990

Essential hypertension: an insulin-resistant state.

Epidemiological evidence supports a link between hyperinsulinemia and blood pressure. In nondiabetic, normotensive individuals, the male sex, age, obesity, and body fat distribution all are associated with higher systolic and diastolic blood pressure and with higher plasma insulin concentrations. Nevertheless, when accounting for the above physiological variables, blood pressure still is independently related to plasma insulin. In the general population, hypertensive individuals have multiple metabolic abnormalities (glucose intolerance, hyperinsulinemia, and dyslipidemia). A striking pattern of overlap exists among obesity, diabetes, and hypertension. Physiological studies (euglycemic insulin clamp) have shown that essential hypertension per se is a state of insulin resistance: lean, nondiabetic subjects with untreated hypertension have a mean 40% reduction in the ability of physiological hyperinsulinemia to stimulate whole-body glucose uptake. Other insulin actions (suppression of hepatic glucose output, lipolysis, lipid oxidation, and promotion of K+ uptake) are conspicuously preserved. In perfused forearm studies, local (intra-arterial) hyperinsulinemia induces subnormal rates of glucose uptake and glycogen synthesis in the skeletal muscle of individuals with essential hypertension. In the San Antonio Heart Study, parental history of non-insulin-dependent diabetes mellitus (NIDDM) is associated with hyperinsulinemia and higher blood pressure and serum lipid levels in nondiabetic probands. In this biethnic population, however, hyperinsulinemia and NIDDM are more prevalent (approximately threefold) among Mexican-Americans than non-Hispanic whites, but hypertension is more prevalent among the latter.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗

PubMed1994

A comprehensive Guyton model analysis of physiologic responses to preadapting the blood volume as a countermeasure to fluid shifts.

The Guyton model of fluid, electrolyte, and circulatory regulation is an extensive mathematical model capable of simulating a variety of experimental conditions. It has been modified for use at NASA to simulate head-down tilt, a frequently used analog of weightlessness. Weightlessness causes a headward shift of body fluids that is believed to expand central blood volume, triggering a series of physiologic responses resulting in large losses of body fluids. We used the modified Guyton model to test the hypothesis that preadaptation of the blood volume before weightless exposure could counteract the central volume expansion caused by fluid shifts, and thereby attenuate the circulatory and renal responses that result in body fluid losses. Simulation results show that circulatory preadaptation, by a procedure resembling blood donation immediately before head-down bedrest, is effective in damping the physiologic responses to fluid shifts and reducing body fluid losses. After 10 hours of head-down tilt, preadaptation also produces higher blood volume, extracellular volume, and total body water for 20 to 30 days of bedrest, compared with non-preadapted control. These results indicate that circulatory preadaptation before current Space Shuttle missions may be beneficial for the maintenance of reentry and postflight orthostatic tolerance in astronauts. This paper presents a comprehensive examination of the simulation results pertaining to changes in relevant physiologic variables produced by blood volume reduction before a prolonged head-down tilt. The objectives were to study and develop the countermeasure theoretically, to aid in planning experimental studies of the countermeasure, and to identify potentially disadvantageous physiologic responses that may be caused by the countermeasure.

Adaptation, Physiological↗

PubMed2000

Physiological and symptom determinants of exercise performance in patients with chronic airway obstruction.

To evaluate the physiological and symptom determinants of exercise performance (EP) as measured by a 6-min walking test (6MWD), Watt(max), and peak oxygen consumption (VO2 ml/min/kg), 105 patients with chronic airway obstruction (CAO) [50 chronic obstructive pulmonary disease (COPD): 44 men, aged 63+/-7 years, forced expiratory volume in 1 sec (FEV1) forced vital capacity (FVC)(-1)% 54+/-13; and 55 asthmatic: 23 men, aged 55+/-10 years, FEV1 FVC(-1) % 65+/-10] underwent evaluation of 6MWD, symptom limited cyclo-ergometer exercise test, spirometry, respiratory muscle function, arterial blood gases and sensation of dyspnoea [using the Borg scale, Visual Analogue Scale (VAS) and Baseline Dyspnoea Index (BDI)]. A hierarchical method of analysis identified the residual volume (RV), total lung capacity (TLC)(-1) ratio, BDI and the patient's age as the strongest and most consistent correlates of EP (r2 = 0.14-0.21). The correlation between EP and its various determinants was not influenced by diagnosis. The relationship between breathlessness and EP was different between men and women: at any given level of exercise, women were more breathless than men. In multivariate analyses that contained both RV TLC(-1) and BDI, the RV TLC(-1) ratio was the strongest correlate of EP, although the BDI remained a significant covariate. Overall, age was the major determinant of EP but inclusion of the RV TLC(-1) ratio and the BDI into the model explained a further 9-15% of the variance in EP. These three covariates together explained 26-34% of the variance between patients. We conclude that in stable CAO patients, the prediction of exercise capacity by anthropometric, demographic, clinical and physiological variables is likely to be low. Age, pulmonary hyperinflation and dyspnoea are the strongest and most consistent correlates of impaired exercise performance. Airways obstruction, measured during expiration using FEV1, does not appear to be a predictor of physiological impairment. These results underline the importance of performing exercise evaluation in CAO patients.

Aged↗

PubMed1982

Perfusion fixation of lungs for structure-function analysis: credits and limitations.

The quality of tissue preservation in lungs fixed by vascular perfusion has been reevaluated. Excised rabbit lungs inflated to 60% of total lung capacity were perfused (zone III conditions) with different but widely used fixatives. The effects of the perfusates on pertinent physiological variables have been assessed by a continuous monitoring, the effects on the pulmonary microstructure by qualitative and morphometric analysis of electron micrographs. Important results include the following. 1) Perfusions with isotonic glutaraldehyde at flow rates within the physiological range produce large increases of perfusion pressure and lung weight that reflect intracellular, interstitial, and intra-alveolar edema. 2) No edema occurs if glutaraldehyde is added to isotonic buffer solutions (total osmolarity 510 mosM). 3) Glutaraldehyde as sole perfusate does not fully eliminate the retractive force of lung tissue. Upon release of transpulmonary pressure the lungs retract by an indeterminable amount. 4) Satisfactory results can be obtained by sequential perfusion with osmium tetroxide and uranyl acetate or glutaraldehyde (510 mosM) followed by osmium tetroxide and uranyl acetate. The latter combination yields optimal preparations to study the alveolar and capillary architecture but causes a hyperosmotic volume loss of lung cells (cell shrinkage).

Animals↗

PubMed1981

Behavioral and physiological correlates of brain serotoninergic unit activity.

Raphe unit activity in rats and cats displays a slow and regular discharge pattern across a variety of situations. The activity is, however, state-dependent, displaying a marked reduction during slow wave sleep and almost complete quiescence during REM sleep. Other than the level of synaptic serotonin, very little is known about the physiological variables affecting these neurons. Behaviorally, raphe neuron activity is correlated with arousal or tonic motor activity, and appears to be driven by phasic afferent input. It is hypothesized that these neurons exert a general modulatory role upon physiology and behavior.

Animals↗

PubMed1988

Development of sleep states in normal premature and full-term newborns.

THE AIMS OF OUR STUDY WERE: 1) to answer the question "Do sleep states exist in normal premature infants;" 2) to analyze the development of sleep cycle and sleep state characteristics in premature and full-term newborns. Polygraph recordings were done on 38 normal, appropriate for gestational age newborns, born at 30 to 41 weeks (w) of gestation. All infants fell asleep in active sleep (AS). Postwaking AS was significantly shorter than the next AS. Mean sleep cycle duration increased from approximately 46 min at 31-34 w of conceptional age (CA) to 70 min. at 35-36 w CA. In all infants we observed stable, greater than 5 min AS and quiet sleep (QS) periods, as defined by EEG and REM criteria. Indeterminate sleep was about 30% of the total sleep cycle at 31-34 w; it decreased to 12% at 35-36 w. Both duration and percentage of AS and QS significantly increased at 35-36 w and remained stable up to 39-41 w CA. Values of QS were significantly reduced when defined by additional criteria (respiratory rate, tonic chin EMG or motility). Concordance of QS criteria was not significantly better in older versus younger groups of infants. At all ages, AS values were insensitive to changes in the criteria chosen to define them. The contrast, starting from 31-34 w CA, between AS and QS as defined by EEG and REM criteria could account for state differences in the control of many physiological variables in prematures.

Child Development↗

PubMedDate not supplied

Physiological reactivity and Type A behavior in preschool children: a longitudinal study.

Measurements of Type A behavior were related to cardiovascular (systolic and diastolic blood pressure, heart rate) and neuroendocrine (urinary catecholamines and cortisol) reactivity in 30 male and 30 female preschool children during various active conditions at their mean ages of 3.5, 4.5, 5.5, and 6.5. Significant elevations of physiological arousal occurred in most active conditions and for all physiological variables except cortisol. Playgroup leaders in daycare centers filled out a Swedish version of the scale measuring Type A behavior, and boys obtained significantly higher scores than girls. Whereas Type A scores were relatively consistent over time, however, physiological reactivity was not a stable individual characteristic, and correlations between Type A scores and cardiovascular reactivity reached significance in only 4 of 33 tests for the boys (one negative correlation) and in 1 case for the girls. Correlations between Type A scores and catecholamine reactivity did not reach significance. In summary, the data do not support the assumption of a consistent relationship between Type A behavior and physiological reactivity in preschool children. A significant correlation (r = .57, p less than .01) found for boys during a computer game suggests that an association may exist during "Type A-relevant" challenge.

Age Factors↗

PubMed2006

Cold stress and hypoglycemia in the late preterm ("near-term") infant: impact on nursery of admission.

Late preterm infants (34-37 weeks gestation) pose unique challenges to physicians and nurses involved in their care after birth. They may be cared for in different units within hospitals after birth, including Neonatal Intensive Care Units, Newborn Nurseries, or rooming in with the mother. As a result of their gestational age and birth weight, the late preterm infant is often assessed quickly and triaged identical to term infants. Such practice can potentially result in a lack of attention to important components for successful transition after birth. Cold stress and hypoglycemia are the two important problems in late preterm infants which require immediate treatment. Thus, surveillance of these and other physiological variables is needed to insure that they do not affect successful adaptation during the early hours and days after birth.

Adaptation, Physiological↗

PubMed2000

Mental ability age 11 years and health status age 77 years.

OBJECTIVES: to measure the effects of childhood mental ability on health in old age. DESIGN: longitudinal cohort study. SETTING: community-based. PARTICIPANTS: survivors of the 1932 Scottish Mental Survey cohort randomly selected from the Community Health Index in North East Scotland. MEASUREMENTS: (i) presence of disease by diagnostic category; (ii) cardiovascular, respiratory, anthropomorphic, sensory and locomotor physiological variables; (iii) Barthel index of functional independence; (iv) socio-demographic and socio-economic variables as health status predictors; and (v) score on the Moray House Test in 1932. RESULTS: There was no significant difference in Moray House Test score in 1932 between those with (mean 39.7, S.D. 13.8) and without (mean 40.1, S.D. 12.1) current disease (F = 0.04, P = 0.84). Physiological health status was predicted by demi-span (F = 6.87, P< 0.001), sex (F = 3.69, P = 0.001), deprivation category (F = 1.45, P = 0.05) and the interaction between sex and deprivation category (F = 2.01, P = 0.002). Moray House Test score in 1932 correlated significantly and positively with Barthel score (r = 0.24, P < 0.001). No additional general linear models added any other significant socio-economic variable once Moray House Test Score in 1932 was entered. Moray House Test score in 1932 remained significant (beta = 0.16, P = 0.024) after Mini Mental State Examination score was entered and found to be significant (beta = 0.21, P = 0.003). CONCLUSION: socio-economic and socio-environmental factors are important determinants of some aspects of inequalities in health in old age in this cohort. Pre-morbid mental ability was an important independent predictor of late-life functional independence.

Aged↗

PubMed2001

Prediction of lidocaine tissue concentrations following different dose regimes during cardiac arrest using a physiologically based pharmacokinetic model.

BACKGROUND: The purpose of our study was to develop a physiologically based pharmacokinetic (PBPK) model describing the behavior of lidocaine in humans by scaling up physiological variables from animal models of cardiac arrest. We attempted to identify the optimal dose regime for lidocaine during cardiac arrest using this model. METHODS AND RESULTS: We designed a flow-dependent PBPK model representing nine body tissues for lidocaine. Physiological organ flow rates, tissue volumes, and plasma-tissue partition parameters for lidocaine in humans were taken from the literature. Data from published animal studies were used to estimate loss of organ blood flow during cardiac arrest and lidocaine tissue partition coefficients. The model assumed a 70 kg cardiac arrest patient. The following five lidocaine dose regimes were simulated: (1) 4 mg/kg i.v. push (IVP) (2) 1.5 mg/kg IVP then 1.5 mg/kg IVP in 4 min, (3) 3 mg/kg IVP, (4) 2 mg/kg IVP, and (5) 1.5 mg/kg IVP. A simulation of Regimen 2, which is the current American Heart Association (AHA) recommendation, suggests that the concentration of lidocaine is suboptimal at the decision point (3-5 min) to administer another dose. Regimen 4 offers a slightly more rapid progress towards optimal cardiac concentrations and more acceptable brain concentrations compared to regimes 1-3. CONCLUSION: Simulations from our PBPK model suggest that the current AHA lidocaine dose regime for cardiac arrest may not result in optimal lidocaine concentrations in the heart and brain. Simulations suggest that 2 mg/kg IVP may be the most acceptable lidocaine dose regime during cardiac arrest.

Algorithms↗

PubMed2003

Crotalidae polyvalent immune Fab antivenom limits the decrease in perfusion pressure of the anterior leg compartment in a porcine crotaline envenomation model.

STUDY OBJECTIVE: Crotalidae Polyvalent Immune Fab (CroFab; FabAV) antivenom prevents a decrease in perfusion pressures in intramuscular crotaline envenomation compared with normal saline solution. METHODS: We used a randomized, blinded, controlled acute animal preparation. Twenty anesthetized and instrumented swine were injected intramuscularly with 6 mg/kg Crotalus atrox venom into the anterior tibialis muscle of each hind limb (time 0). One hour after envenomation (time 1 hour), animals were randomized to receive 8 vials of reconstituted FabAV or an equal volume of normal saline solution (control) through a central venous line. The main outcome variable was the area under the perfusion-time curve (AUC) of the anterior compartment of the hind limb measured from time 1 hour to time 8 hours. Perfusion pressure was defined as mean arterial pressure-compartment pressure. Additionally, physiologic variables, including pulse rate, prothrombin time, fibrinogen level, platelet count, hemoglobin level, and hematocrit level, were monitored. RESULTS: Venom injection resulted in a decrease in average perfusion pressures from 54.1 mm Hg (time 0) to 31.7 mm Hg (time 1 hour). Comparison of AUC between groups from time 1 hour (time of treatment) to the completion of the study at time 8 hours revealed a 57% greater AUC in animals that received FabAV (mean+/-SD: 211.1+/-67.9 versus 134.5+/-55.8 mm Hg/h; P =.036; 95% confidence interval for difference 5.9 to 147.3). Comparison of the time curves for the mean prothrombin time from time 1 hour to the completion of the study by means of repeated-measures analysis of variance revealed a significant increase in the control group (P =.02). No significant difference was detected in the time curves for the means of mean arterial pressure, compartment pressure, pulse rate, hemoglobin level, hematocrit level, fibrinogen level, or platelet count over the course of the study. FabAV was found to significantly increase survival time when compared with the effect of the normal saline solution control from time 1 hour to time 8 hours, as determined by means of Kaplan-Meier estimation and the log-rank test (P =.029). CONCLUSION: FabAV limits the decrease in perfusion pressures in the anterior leg compartment after intramuscular crotaline venom injection in swine compared with saline solution. In addition, FabAV might prevent the development of coagulopathy and increase survival time in this model.

Animals↗

PubMed2002

Effect of a culturally sensitive cholesterol lowering diet program on lipid and lipoproteins, body weight, nutrient intakes, and quality of life in patients with systemic lupus erythematosus.

OBJECTIVE: To evaluate the effect of a culturally sensitive cholesterol lowering diet program on lipid and lipoproteins, body weight, nutrient intakes, and quality of life (QOL) in patients with systemic lupus erythematosus (SLE). METHOD: Seventeen patients with SLE were randomized to a Step 2 diet intervention group or a control group for 12 weeks. The diet intervention was made up of weekly group sessions during the first 6 weeks followed by telephone counseling every 2 weeks for the last 6 weeks. Data on fasting lipid and lipoproteins, body weight, food intake (3 day food record), and QOL were collected at baseline, 6 weeks, and 12 weeks. Program acceptability was assessed in the diet group at 6 weeks. RESULTS: The intervention was found to be highly acceptable and culturally sensitive. The changes in nutrient intakes at 6 and 12 weeks in the diet group were -49% and -33%, respectively, for cholesterol, -44% and -32%, respectively, for percentage calories from fat, and -46% and -32%, respectively, for percentage calories from saturated fat. The corresponding figures in the control group were +22% and -8% for cholesterol, +9% and +6% for percentage calories from fat, and +5% and +7% for percentage calories from saturated fat. The treatment by time interaction was significant for all the dietary variables (p = 0.0003 to 0.02). QOL was reported to improve by 15-17% in the diet group and decrease by 4-6% in the control group, and the treatment by time interaction was significant (p = 0.05). The changes in the physiological variables at 6 and 12 weeks in the diet group were -10% and -6%, respectively, for total cholesterol, -10% and -2%, respectively, for low density lipoprotein (LDL) cholesterol, -11% and -4%, respectively, for high density lipoprotein (HDL) cholesterol, -25% and -34%, respectively, for very low density lipoprotein (VLDL) cholesterol, -8% and -24%, respectively, for triglycerides, and -2% and -5%, respectively, for body weight. The corresponding figures in the control group were -5% and -3% for total cholesterol, -6% and -5% for LDL cholesterol, 0% and +12% for HDL cholesterol, +4% and -8% for VLDL cholesterol, -6% and -15% for triglycerides, and -5% and -6% for body weight. The treatment by time interaction was significant for HDL cholesterol (p = 0.04). A significant reduction was seen in the diet group for total cholesterol at 6 and 12 weeks, LDL and HDL cholesterol at 6 weeks, and body weight at 12 weeks (p = 0.0002 to 0.01). CONCLUSION: This culturally sensitive cholesterol reducing diet program was highly accepted and effective in changing the diet and QOL of patients with SLE. The effect on serum lipids, lipoproteins, and body weight, however, was modest. A larger randomized study with a longer intervention period is necessary to test the effectiveness of a cholesterol-lowering diet on lipids and lipoproteins in patients with SLE.

Adult↗

PubMed1986

Comparative cold responses of men and women to external and internal cold stimuli.

Experiments were conducted comparing the relative contribution of internal and external cold stimuli in the initiation of horripilation (cutis anserina or "goose flesh") in men and women. Five men and five women were compared. Subjects wore a water perfused vest which covered the entire thorax and allowed torso skin temperature to be maintained at either 34 degrees C, 30 degrees C, 26 degrees C, or 22 degrees C in four separate experiments. After stabilization, the subject's legs were immersed in water maintained at 16 degrees C for 20 min. After removing their legs from the water, subjects then pedalled a stationary bicycle ergometer at minimum resistance to facilitate the return of cooled venous blood to the thoracic core. Horripilation was episodic in both men and women but related significantly to torso skin temperature in men and percent body fat in women over the range of torso skin temperatures tested. There was no significant association between horripilation episodes and either the stabilization, immersion, or minimal exercise phase of the experiment. Core body temperature, as measured by rectal and esophageal thermistors, decreased significantly in men from 37.0 degrees C and 36.6 degrees C at 34 degrees C torso skin temperatures, but remained unchanged in women. The results suggest that skin cooling initiates horripilation whose occurrence and pattern are affected by different combinations of morphological or physiological variables in men and women.

Adult↗

PubMed2005

Ontogenetic shifts in thermal tolerance, selected body temperature and thermal dependence of food assimilation and locomotor performance in a lacertid lizard, Eremias brenchleyi.

We used Eremias brenchleyi as a model animal to examine differences in thermal tolerance, selected body temperature, and the thermal dependence of food assimilation and locomotor performance between juvenile and adult lizards. Adults selected higher body temperatures (33.5 vs. 31.7 degrees C) and were able to tolerate a wider range of body temperatures (3.4-43.6 vs. 5.1-40.8 degrees C) than juveniles. Within the body temperature range of 26-38 degrees C, adults overall ate more than juveniles, and food passage rate was faster in adults than juveniles. Apparent digestive coefficient (ADC) and assimilation efficiency (AE) varied among temperature treatments but no clear temperature associated patterns could be discerned for these two variables. At each test temperature ADC and AE were both higher in adults than in juveniles. Sprint speed increased with increase in body temperature at lower body temperatures, but decreased at higher body temperatures. At each test temperature adults ran faster than did juveniles, and the range of body temperatures where lizards maintained 90% of maximum speed differed between adults (27-34 degrees C) and juveniles (29-37 degrees C). Optimal temperatures and thermal sensitivities differed between food assimilation and sprint speed. Our results not only show strong patterns of ontogenetic variation in thermal tolerance, selected body temperature and thermal dependence of food assimilation and locomotor performance in E. brenchleyi, but also add support for the multiple optima hypothesis for the thermal dependence of behavioral and physiological variables in reptiles.

Adaptation, Physiological↗

PubMed1982

Comparison of visually estimated age with physiologically predicted age as indicators of rates of aging.

The commonly held view that people age at different rates derives largely from visual estimates of age. Although most people "look their age' everyone can cite examples of individuals in middle and late adulthood who appear to be aging very slowly or very rapidly. Efforts to quantify aging rates scientifically require measurement of a large number of physiological parameters in a large population sample. This paper compares visual estimates of age with physiologically predicted measures to determine their value as indicators of the rate of aging. This study used data from 1086 male participants in the Baltimore Longitudinal Study of the Gerontology Research Center, NIA. These men have provided comprehensive biomedical and psychosocial data at one and one-half years intervals for as long as 20 years. The visual estimate of age was made by the examining physician at the first study visit of each participant, without knowledge of the man's actual age. The error of this estimate was determined by subtracting actual age from estimated age. Correlation analysis of error in estimated age with an objective assessment of biological age based on physiological variables indicated a significant association between the two approaches. When men who have died since their study participation were compared with survivors, the former were found to have been significantly 'older for their age' than the latter using both visual and physiological estimate approaches. To determine whether certain lifestyle traits were associated with variation in these two indicators, multiple regression analyses were performed. These showed that men who smoked, who were fatter, or who were in poor health were predicted as older than their chronological age peers using both approaches. Results of this study suggest that the easily determined visual estimate of age may be a useful indicator of aging rate within a population.

Adolescent↗

PubMed2006

Molecular and physiological diversity among Verticillium fungicola var. fungicola.

The genetic and physiological variability of Verticillium fungicola var. aleophilum responsible for Agaricus bisporus dry bubble disease in North America is well documented but little is known about the var. fungicola affecting European crops. Variability was assessed within this variety and compared with that reported for the var. aleophilum. Eighteen isolates of V. fungicola var. fungicola and four var. aleophilum isolates were analysed for DNA polymorphism, mycelial growth, response to biochemicals produced by A. bisporus, fungicide resistance, and pathogenicity assessed by direct inoculation on sporophore or casing contamination. RAPD and AFLP markers delineated three French isolates from a homogeneous group containing the other var. fungicola isolates, but no correlation could be drawn between DNA polymorphism and the various traits studied. The var. fungicola isolates were more susceptible than the var. aleophilum isolates to the antibiosis effect of A. bisporus. Only mycelial growth rate at 23 degrees C could explain the variability in aggressiveness among the European isolates. The putative effect of the post-incubation temperature on contamination during mushroom cultivation was discussed. This work emphasized that, like the American var. aleophilum, the var. fungicola in Europe is genetically homogeneous, but physiological diversity exists, especially in France where it could be related to less standardized cultural practices.

Agaricus↗