Hyphal network whole field imaging allows for accurate estimation of anastomosis rates and branching dynamics of the filamentous fungus Podospora anserina

The success of filamentous fungi in colonizing most natural environments can be largely attributed to their ability to form an expanding interconnected network, the mycelium, or thallus, constituted by a collection of hyphal apexes in motion producing hyphae and subject to branching and fusion. In this work, we characterize the hyphal network expansion and the structure of the fungus Podospora anserina under controlled culture conditions. To this end, temporal series of pictures of the network dynamics are produced, starting from germinating ascospores and ending when the network reaches a few centimeters width, with a typical image resolution of several micrometers. The completely automated image reconstruction steps allow an easy post-processing and a quantitative analysis of the dynamics. The main features of the evolution of the hyphal network, such as the total length L of the mycelium, the number of “nodes” (or crossing points) N and the number of apexes A, can then be precisely quantified. Beyond these main features, the determination of the distribution of the intra-thallus surfaces (S_i) and the statistical analysis of some local measures of N, A and L give new insights on the dynamics of expanding fungal networks. Based on these results, we now aim at developing robust and versatile discrete/continuous mathematical models to further understand the key mechanisms driving the development of the fungus thallus.

Quantification of physical activity using the QAPACE questionnaire: A two stage cluster sample design survey of children and adolescents attending urban school

BACKGROUND

Quantification of physical activity as energy expenditure is important since youth for the prevention of chronic non communicable diseases in adulthood. It is necessary to quantify physical activity expressed in daily energy expenditure (DEE) in school children and adolescents between 8-16 years, by age, gender and socioeconomic level (SEL) in Bogotá.

METHODS

This is a Two Stage Cluster Survey Sample. From a universe of 4700 schools and 760000 students from three existing socioeconomic levels in Bogotá (low, medium and high). The random sample was 20 schools and 1840 students (904 boys and 936 girls). Foreshadowing desertion of participants and inconsistency in the questionnaire responses, the sample size was increased. Thus, six individuals of each gender for each of the nine age groups were selected, resulting in a total sample of 2160 individuals. Selected students filled the QAPACE questionnaire under supervision. The data was analyzed comparing means with multivariate general linear model. Fixed factors used were: gender (boys and girls), age (8 to 16 years old) and tri-strata SEL (low, medium and high); as independent variables were assessed: height, weight, leisure time, expressed in hours/day and dependent variable: daily energy expenditure DEE (kJ.kg-1.day-1): during leisure time (DEE-LT), during school time (DEE-ST), during vacation time (DEE-VT), and total mean DEE per year (DEEm-TY) RESULTS: Differences in DEE by gender, in boys, LT and all DEE, with the SEL all variables were significant; but age-SEL was only significant in DEE-VT. In girls, with the SEL all variables were significant. The Post-hoc multiple comparisons tests were significant with age using Fisher's Least Significant Difference (LSD) test in all variables. For both genders and for all SELs the values in girls had the higher value except SEL high (5-6) The boys have higher values in DEE-LT, DEE-ST, DEE-VT; except in DEEm-TY in SEL (5-6) In SEL (5-6) all DEEs for both genders are highest. For SEL (3-4) all DEEs are lowest.

CONCLUSIONS

Children and adolescents in Bogotá have less DEE than at other latitudes. Girls have more free time but lower energy expenditure in their different activities. The socioeconomic level has influence in DEE.

[Preeclampsia and benefit form magnesium sulfate. About 105 cases]

OBJECTIVES

The aim of this study was to determine the amount of magnesium sulfate involved when we diagnose a severe preeclampsia in pregnant women. Other goals were to know what the MgSO4 side-effects and complications are, and what benefits this treatment brings to prevent an eclampsia.

PATIENTS AND METHODS

This retrospective and descriptive study was conducted for 7 years. We identified 105 women treated by MgSO4 out of 560 preeclampsia cases. To prevent eclampsia, those women were administrated MgSO4 before, during or after labor. All data about hospitalization term and MgSO4 term administration were collected in order to understand if MgSO4 side-effects for the women and the fetus occurred before, during or after labor. Those tables are compared with the MgSO4 administered dosages.

RESULTS

MgSO4 isn't systematically used in all the preeclampsia cases. Forty percent of women under treatment presented low side effects. Overdoses, encountered in 31.4% of cases, regressed as soon as the MgSO4's perfusion was stopped. No major complications were noted. Only 0.95% of women treated by MgSO4 presented an eclampsia.

DISCUSSION AND CONCLUSION

MgSO4 administered only to women having a neurological preeclampsia, within therapeutic doses and with rigorous monitoring, does not bring deleterious effects to the mother or newborn baby. Consequently, MgSO4's benefits were above the risks.

[Magnesium sulfate in the prophylaxis of eclampsia: a retrospective study]

INTRODUCTION

The use of magnesium sulfate (MgSO(4)) has been advocated since 2000 in France in the management of eclampsia. The aim of this study was to determine the frequency of use of this treatment for eclampsia in a French department.

PATIENTS AND METHODS

All patients obstetrical patients admitted to Critical Care Units of Seine-Maritime for eclampsia over a period of 7 years (2002-2008) were included. Obstetric data, the treatment used for eclampsia and pre-eclampsia and maternofetal complications were collected. The primary outcome parameter was the use of MgSO(4) in the secondary prevention of eclampsia.

RESULTS

Thirty-nine patients were included. Nineteen patients (48%) had eclampsia in prepartum, three (8%) in per-partum and 17 (44%) in post-partum periods. The use of MgSO(4) in the secondary prevention of eclampsia was observed in 92% of cases (36/39). Primary prevention was seen in 8% of cases. The duration of treatment was 2 days (1-7 days). The maternal and perinatal mortality was respectively 2.5 and 11%.

CONCLUSION

In this study, the use of MgSO(4) in the secondary prevention is frequent. This result emphasizes the importance of the recommendations of learned societies in the homogenization of the management of rare but serious conditions such as eclampsia.

[Amniotic fluid embolism during curettage for a pregnancy arrest. Case report]

Amniotic fluid embolism is always a serious complication during the peripartum period. We report the case of an amniotic fluid embolism during curettage for a pregnancy arrest at 13 weeks. The diagnosis was confirmed by the presence of epithelial cells into the maternal blood.

Altered myosin isoform expression in rat skeletal muscles induced by a changed thyroid state

The aim of our study was to find out, which are the thyroid linked mechanisms responsible for the changes in myosin isoform composition which accompany endurance training (ET) in rodents. We studied the interaction between ET and altered sedentary group with no thyroid treatment or Se group. Six groups of rats were compared: (1) a trained group with no thyroid treatment or T group; (2) a thyroid state in rats; (3) a sedentary group rendered hypothyroid with 6-n-propyl thio uracil (H); (4) a sedentary group rendered hyperthyroid with T3 (150 microg kg(-1) every other day for 4 weeks) (St); (5) trained rats rendered hyperthyroid with T3 (150 microg kg(-1) every other day for 4 weeks) (Tt) and (6) a trained group kept euthyroid with T3 (150 ng kg(-1) every other day for 4 weeks) (Te). In each group myosin isoform composition was determined in five muscles, three locomotor muscles: (1) extensor digitorum longus, (2) superficial lateral gastrocnemius, (3) deep medial gastrocnemius, (4) an antigravity muscle, the soleus and (5) a rhytmic respiratory muscle, the crural diaphragm. Different muscles responded in a specific way to variations of the thyroid state and training.

Oxidative stress in hemodialyzed patients during exhausting exercise

BACKGROUND

This study was designed to study the effect of an exhausting exercise test on plasma lipid peroxidation marker (malondialdehyde, MDA) and on vitamin E levels in hemodialyzed patients (HD) compared to healthy control subjects (HC).

METHODS

Eight sedentary chronically HD, (39.0+/-10.8 years) and eight sedentary HC (38.4+/-12.4 years) were studied. Before exercise, the activity of scavenger enzymes [plasma and erythrocyte glutathione peroxidase (GPX), and erythrocyte superoxide dismutase (SOD)] was determined. All subjects performed a symptom-limited exercise test; respiratory gas exchanges were collected on-line and blood was sampled five min before exercise, at exhaustion and after 30 min of recovery.

RESULTS

At rest, the activity of plasma and erythrocyte GPX and erythrocyte SOD was significantly lower in HD than in HC. Exercise provoked an increase of plasma MDA concentration after recovery in HD patients, whereas our HC group show a decrease in MDA plasma level immediately after exercise, returning to the rest values during recovery. Exercise induced no change of vitamin E concentration in HD whereas in HC it increased during recovery.

CONCLUSIONS

Our results indicate that: 1) at rest: although hemodialyzed patients showed lower scavenger enzymes activity than HC subjects, there was no difference in MDA plasma level between groups; 2) there is some evidence that physical exercise contribute to oxidative stress during recovery in HD patients, and 3) exercise induced an increase in plasma vitamin E concentration in healthy subjects.

Plasticity of skeletal myosin in endurance-trained rats (I). A quantitative study

The aim of this study was to quantify modifications in the expression of skeletal myosin light chain (MLC) and myosin heavy chain (MHC) isoforms of five muscles, according to their fiber composition and function, following endurance training in rats. Rodents were assigned randomly to one of two groups: caged sedentary controls (C) or endurance-trained rats (T). In T rats, three out of the four fast and mixed muscles studied exhibited a significant increase in the expression of MLC1s, 1f and 2s and a significant decrease in MLC2f and 3f, the exception being the plantaris muscle. In two out of the four muscles we observed a significant increase in MHCI and IIa, the exception being both gastrocnemii, where the expression of MHCI did not change. In the soleus of T rats, the expression of MLC1s, 2f and 3f decreased significantly, while that of MLC2s increased significantly, compared with those of C rats. The expression of MHCIIa in T rats decreased significantly compared with that of C rats, while the expression of MHCI increased significantly. In all muscles studied, a significant slowing of myosin isoforms was observed after endurance training.

Exercise does not induce oxidative stress in trained heart transplant recipients

PURPOSE

The objectives of this study were twofold: 1) to determine the effect of incremental exercise to volitional fatigue on plasma levels of lipid peroxidation (malondialdehyde) in heart transplant recipients (HRT) and 2) to examine blood antioxidant capacity in HTR by assessment of antioxidant enzyme activities and vitamin E levels.

METHODS

Seven endurance-trained HTR (mean +/- SD; age 39.7 +/- 12.8 yr) and seven endurance-trained healthy, age-matched control subjects (HC) (mean age 40.6 +/- 10.7 yr) performed a symptom-limited incremental exercise test on a cycle ergometer. Venous blood samples were obtained at rest, exercise, and during recovery and analyzed for plasma levels of malondialdehyde (MDA) as well as markers of blood antioxidant capacity. After exercise and during recovery, all dependent measures were corrected for plasma volume changes induced by exercise. Significance was established at (P < 0.05).

RESULTS

No group differences existed in plasma levels of MDA at rest. Further, graded exercise did not alter plasma levels of MDA in either group. Resting erythrocyte glutathione peroxidase (GPX) activity was significantly lower and erythrocyte superoxide dismutase (SOD) activity was higher in HTR compared with HC. Finally, at rest, no group differences existed in plasma GPX activity or vitamin E levels.

CONCLUSIONS

Graded exercise to fatigue does not promote an increase in oxidative stress in blood of exercise trained HTR. Therefore, physical exercise does not appear to pose an oxidative-stress risk for these patients.

Relations between the stage of cell maturation and lactate transporter activities in rat neonatal muscle cells in culture

Lactate transport was investigated in newborn rat muscle cells in culture. The aim was to study the lactate transport function at two stages of cell differentiation in culture: (i) during the proliferative phase characterized by myoblasts and myotubes (MyB/MyT2) obtained after 2-3 seedings, (ii) when myotubes (MyT1) grow old in culture after 8-9 seedings. In both developmental stages MyB/MyT2, lactate was carried following a saturable and sigmoidal velocity curve: the Hill and the Scatchard plot analyses confirmed an allosteric or multisite mechanism of lactate transport with two classes of carriers: one of low and one of high affinity i.e., 8.6 and 0.95 mm, respectively, which are associated with high and low transport capacities (V(m)) i.e., 9.1 and 0.67 nm/min/mg, respectively. With MyT1, the velocity curve of lactate transport presented a hyperbolic profile, and the Hill plot analysis gave a Hill number near one suggesting that for cell aging in culture the decrease in cooperativity shows that lactate transport essentially occurs through the low affinity transport system. Inhibitor effects also contributed to evidence for at least two systems of transport. Results obtained from primary cells give evidence for the early activity of lactate transport system at the Myb/MyT2 stage and its evolution during cell aging in culture (MyT1). Sarcolemmal lactate transport in primary cultures of myocytes is accomplished by multiple carriers, neither of which are MCT1 or MCT2 as confirmed by immunoblots.

Effects of anabolic/androgenic steroids on regenerating skeletal muscles in the rat

We have examined the effect of male sexual hormones on the regeneration of skeletal muscles. Degeneration/regeneration of the left soleus and extensor digitorum longus muscles (EDL) of Wistar male rats was induced by an injection of snake venom (2 microg, Notechis scutatus scutatus). During the muscle regeneration (25 days), rats were treated with either oil (CON), nandrolone (NAN), NAN combined with exercise (NAN + EXE) or were castrated (CAS). Muscle growth and myosin heavy chain (MyHC) isoform content of regenerating muscles were studied. Castration altered the concentrations of MyHC in venom-treated EDL (P < 0.01) and soleus (P < 0.05). NAN increased the mass (P < 0.01) of regenerating soleus and decreased the relative amount of fast MyHC protein (% of total, P < 0.05). The effect of NAN + EXE on the fast MyHC proteins of venom-treated soleus was opposite (P < 0.05). NAN and NAN + EXE were without effect on the regenerating EDL (P > 0.05). In conclusion, it is possible that male sexual hormones play a role in the growth (synthesis of contractile proteins) of regenerating muscles in rat. In addition, contrary to NAN + EXE, NAN could be beneficial to soleus regeneration.

Chronotropic competence in endurance trained heart transplant recipients: heart rate is not a limiting factor for exercise capacity

OBJECTIVES

The purpose of this study was to show that the chronotropic potential of the well trained heart transplant recipient (HTR) does not limit exercise capacity.

BACKGROUND

Chronotropic incompetence is considered to be the main limiting factor of the functional capacity of heart transplant recipients. However, no systematic study had been published on patients who had spontaneously undergone heavy endurance training for several years.

METHODS

Heart rate (HR) and respiratory gas exchanges (VO2, VCO2, VE) were measured in 14 trained HTRs (T-HTRs) during exercise tests on a bicycle, on a treadmill and by Holter electrocardiography during a race.

RESULTS

Peak values observed in T-HTRs during the treadmill test were higher than those reached during the bicycle test (VO2peak: 39.8+/-6.9 vs. 32.5+/-7.8 ml x kg(-1) x min(-1), p < 0.001; HRpeak: 169+/-14 vs. 159+/-16 bpm, p < 0.01). During treadmill exercise VO2peak and HRpeak values observed were very close to the mean predicted VO2pmax and HRpmax. The maximum heart rate during the race (HRrace) was greater than HRpeak values during the treadmill test (179+/-14 vs 169+/-14 bpm, p < 0.01) and slightly above the mean predicted values (HRrace/HRpmax X 100 = 101+/-10%). The treadmill exercise test yields more reliable data than does the bicycle test.

CONCLUSIONS

Extensive endurance training enables heart transplant recipients to reach physical fitness levels similar to those of normal sedentary subjects; heart rate does not limit their exercise capacity.

High serum luteinizing hormone levels induce ovarian delta4 cytochrome P450c17alpha down-regulation in hirsute women: complete effect on 17-hydroxylase and partial effect on 17,20-lyase

It is well known that normal and mildly elevated luteinizing hormone (LH) levels induce increased activity of ovarian 17-hydroxylase and 17,20-lyase, the cytochrome P450cl7alpha (P450) enzymes. This leads to increased ovarian 17alpha-hydroxyprogesterone (17-OHP) and androstenedione production. In contrast, it has been shown in both in vitro and in vivo studies in animals and in in vitro studies in women that high LH concentrations have opposite effects on these enzymes. These LH down-regulating effects appear to be more marked on 17,20-lyase than on 17-hydroxylase. Finally, these LH effects have not been reported in vivo in women. Therefore, we investigated the relationships between serum LH levels and serum 17-OHP and androstenedione concentrations in 263 consecutive hirsute women (HW) with normal serum 17-OHP responses to acute adrenocorticotropin (ACTH) stimulation. The patterns of basal serum steroid concentrations differed according to the basal serum LH levels. Indeed, for relationships between LH and 17-OHP concentrations, a positive correlation (P < 0.001) was found between the levels of these parameters when LH levels ranged from 0.2 to 9.0 IU/l. Conversely, for LH levels greater than 9.0 to 21.0 IU/l, LH values were negatively correlated (P<0.001) with 17-OHP concentrations. Similar results were observed for relationships between LH and androstenedione levels but the LH peak level related to decreasing androstenedione concentrations was 12.0 IU/l. Finally, the mean 17-OHP level in patients with LH levels which induced marked P450 down-regulation (i.e. more than 12 IU/l) was similar to that in patients with LH levels within the normal range (i.e. less than 6 IU/l). In contrast, the mean androstenedione level in the former patients was markedly higher (P<0.001) than that in the latter patients. In conclusion, as previously reported in in vitro studies, this in vivo study indicates that LH induces stimulating and down-regulating effects on both ovarian delta(4)17-hydroxylase and delta(4)17,20-lyase activities as serum LH levels gradually increase. However, in contrast to in vitro studies, LH levels which induce P450 down-regulation appear to be less effective on delta(4)17,20-lyase than on delta(4)17-hydroxylase in HW. This strongly suggests that serum factors induce, in most HW, a marked increase in delta(4)17,20-lyase, but not in delta(4)17-hydroxylase, activity leading to both partial impairment of LH-induced delta(4)17,20-lyase down-regulation and complete LH-induced delta(4)17-hydroxylase down-regulation in these patients.

Lactate transport in L6 skeletal muscle cells and vesicles: allosteric or multisite mechanism and functional membrane marker of differentiation

Membrane lactate transport was studied in skeletal muscle cells and membrane vesicles from the L6 line in relation to in vitro myogenesis. In myoblasts, lactate was transported by simple diffusion and insensitive to classical inhibitors: a positive correlation between onset of creatine kinase activity and lactate transport in differentiated myotubes was observed and could be considered to be a functional marker of cell differentiation. In myotubes, complete analysis of the velocity curves (direct coordinates, Eadie-Scatchard plots, Hill plots) gave parameters showing that lactate was carried by an allosteric or multisite system. This was confirmed by using sarcolemmal vesicles and specific inhibitors. In whole cells, alpha-cyano-4-hydroxycinnamic acid (CIN) and parachloromercuribenzylsulphonic acid (pCMBS) inhibited the maximal velocity without modifying the global cooperativity of the system. The weak effect of 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS), which has a low affinity constant (Ki = 22.5 microM), implicated the monocarboxylate system rather than the anionic exchanger as a carrier system in muscle cells. CIN and DIDS exhibited one type of interaction with lactate carriers, and the curvilinear shape of the lactate Hill plot with or without inhibitors suggested that inhibitors were active at the same family of interaction sites and had a common range of affinities. The apparent competitive inhibition of pyruvate (Ki = 3.2 mM) did not modify the transport pathway of lactate in L6 myotubes. In conclusion, kinetic analysis of lactate transport in the presence or absence of inhibitors gave evidence for a multisite lactate carrier activity in myotubes composed of two systems at least, related to two or three isoforms of lactate carriers.

Effect of the serotonin 5-HT4 receptor agonist cisapride on aldosterone secretion in corticotropic insufficiency and primary hyperaldosteronism

Serotonin (5-HT) stimulates aldosterone secretion in man through activation of 5-HT4 receptors coupled to adenylyl cyclase via a Gs regulatory protein. In adrenocortical cells, the levels of expression of the Gs protein and ACTH receptor are decreased when the cells are deprived of ACTH and angiotensin II (ANG II). In order to examine the possible influence of ACTH and ANG II on the responsiveness of human glomerulosa cells to 5-HT, we have investigated the effect of cisapride, a 5-HT4 receptor agonist, on plasma aldosterone in patients with suppressed plasma ACTH, i.e. patients with corticotropic insufficiency (CI), and in patients with suppressed renin-ANG II activity, i.e. patients with primary hyperaldosteronism (PH) including both aldosterone-producing adenoma and idiopathic hyperaldosteronism. After 2 h of recumbency, all patients received a single oral dose of 10 mg cisapride. In the CI group, cisapride induced a 5-fold increase in plasma aldosterone levels without any modification of plasma renin, potassium or cortisol levels. Combined administration of cisapride and ACTH caused an increase in plasma aldosterone similar to that produced by ACTH alone. In the PH group, cisapride was still able to cause a 3.6-fold increase in plasma aldosterone levels while renin remained suppressed throughout the study. Taken together, these data show that cisapride stimulates aldosterone secretion in CI and PH patients, indicating that prolonged suppression of plasma ACTH or renin-ANG II activity does not affect the sensitivity of glomerulosa cells to 5-HT. The present study also demonstrates that the stimulatory effects of 5-HT and ACTH on aldosterone secretion are not additive.

Gas exchange and cardiovascular kinetics with different exercise protocols in heart transplant recipients

Metabolic and cardiovascular adjustments to various submaximal exercises were evaluated in 82 heart transplant recipients (HTR) and in 35 control subjects (C). HTR were tested 21.5 +/- 25.3 (SD) mo (range 1.0-137.1 mo) posttransplantation. Three protocols were used: protocol A consisted of 5 min of rectangular 50-W load repeated twice, 5 min apart [5 min rest, 5 min 50 W (Ex 1), 5 min recovery, 5 min 50 W (Ex 2)]; protocol B consisted of 5 min of rectangular load at 25, 50, or 75 W; protocol C consisted of 15 min of rectangular load at 25 W. Breath-by-breath pulmonary ventilation (VE), O2 uptake (VO2), and CO2 output (VCO2) were determined. During protocol A, beat-by-beat cardiac output (Q) was estimated by impedance cardiography. The half times (t1/2) of the on- and off-kinetics of the variables were calculated. In all protocols, t1/2 values for VO2 on-, VE on-, and VCO2 on-kinetics were higher (i.e., the kinetics were slower) in HTR than in C, independently of workload and of the time post-transplantation. Also, t1/2 Q on- was higher in HTR than in C. In protocol A, no significant difference of t1/2 VO2 on- was observed in HTR between Ex 1 (48 +/- 9 s) and Ex 2 (46 +/- 8 s), whereas t1/2 Q on- was higher during Ex 1 (55 +/- 24 s) than during Ex 2 (47 +/- 15 s). In all protocols and for all variables, the t1/2 off-values were higher in HTR than in C, In protocol C, no differences of steady-state VE, VO2, and VCO2 were observed in both groups between 5, 10, and 15 min of exercise. We conclude that 1) in HTR, a "priming" exercise, while effective in speeding up the adjustment of convective O2 flow to muscle fibers during a second on-transition, did not affect the VO2 on-kinetics, suggesting that the slower VO2 on- in HTR was attributable to peripheral (muscular) factors; 2) the dissociation between Q on- and VO2 on-kinetics in HTR indicates that an inertia of muscle metabolic machinery is the main factor dictating the VO2 on-kinetics; and 3) the VO2 off-kinetics was slower in HTR than in C, indicating a greater alactic O2 deficit in HTR and, therefore, a sluggish muscle VO2 adjustment.

The management of terminal illness: opinions of the medical and nursing staff in a Paris University Hospital

The views of French physicians and nurses of the organization of palliative care have not been previously analyzed. We surveyed opinion on the care of the terminally ill in a 1,000-bed Paris university hospital. Data were obtained in 1992 by non-directed interviews of leading physicians and semi-directed interviews of nurses. Most physicians wished to managed terminal care in their departments. Patients and family preferences were considered in choosing the place for care. Treatment of hospitalized patients should be limited to relieving symptoms. Department heads and senior nurses agreed on most problems encountered in the management of care. The psychological burden borne by nurses was emphasized. Terminal care training and the possibility of consulting experts in palliative care were the main suggestions for improvement cited by both department heads and senior nurses. Integrating this knowledge into the planning process should result in improved care and in increased satisfaction for the care providers.

Effect of physical exhaustion on cognitive functioning

Experiments utilizing reaction time to measure the effects of fatigue on cognition must discern sensitivity of peripheral and central processing to strenuous exercise. The additive factors method enables one to stipulate that if fatigue interacts with subjects' reaction time in a decision task, central processing is affected by fatigue. While pedaling at different intensities, 13 physically-fit men had to perform a series of short-term memory tests. The tests were executed during a constant workload session and a progressive workload session in which subjects pedaled until exhaustion. Subjects provided ratings on Borg's 1970 scale to measure the psychological effects of the physical effort such as perceived exertion. Allocation of processing resources was also measured to determine attentional constraints exerted by the dual-task situation. Analysis showed that decision reaction time was affected only during the exhausting bout of the progressive workload session and for the more difficult decision task. We discuss our results in the context of arousal and the allocation of processing resources.

Long-term histological follow-up of genetically modified myoblasts grafted into the brain

Although primary muscle cells have been used as intracerebral vehicles for transgene expression in the past, data concerning their long-term survival after grafting into the brain, and the reaction of the host tissue to their implantation are lacking. In order to study these aspects, we have implanted, into the brain, primary muscle cells infected ex vivo with recombinant retroviruses carrying the E. coli LacZ gene. The muscle cells were delivered stereotaxically into different areas of the brain of adult rats and the grafts were analyzed up to 105 days after implantation. Intraventricular implantations did not lead to surviving grafts. In contrast, myoblasts developed when they were grafted into gray or white matter regions. They appeared numerous during the first weeks, but decreased dramatically in number over time. Over months, the grafts appeared to fill up with collagen. Astrocytes elaborated a continuous glia limitans surrounding the implant. Blood vessels coming from the host tissue were found within the grafts. The blood-brain barrier was permanently disrupted within the transplants. beta-Galactosidase activity was abundant during the first weeks, but decreased to a very low level subsequently. This decrease paralleled that of the number of muscle cells. In conclusion, myoblasts transplanted into the adult brain survived only temporarily, which implies a transient transgene expression. In addition, before being eliminated, muscle cells were surrounded by a glia limitans, which may limit exchanges with the host tissue. Altogether, these results suggest that intracerebral transplantation of myoblasts may possibly provide a relevant vehicle only for short-term delivery of a gene product.

Effect of increased physical activity on growth and differentiation of regenerating rat soleus muscle

Our purpose was to determine the effect of physical exercise on growth and differentiation during regeneration of a slow-twitch muscle. Degeneration/regeneration of the left soleus muscles of Wistar female rats was induced by injection of a snake venom. Muscular differentiation was studied by monitoring the sequential expression of the various myosin heavy chain isoforms (MHCs). Rats were assigned to one of two groups: cage sedentary (n = 14) or exercised (n = 16). The exercise programme began 1-day post-injection and the rats ran 1 h/day on a motorized treadmill. Then, 9 and 25 days after venom treatment, the soleus MHC phenotype as determined by immunohistology, electrophoresis and immunoblotting, was studied. At 25 days the expression of MHCs by regenerating soleus was not changed by the increased level of physical activity (P > 0.05). Exercised and sedentary regenerating muscles contained similar numbers of type-I fibres (100% of total fibres), levels of MHC-1 (85.4 and 89.5% of total MHCs), MHC-2a and M/HC-2x/d and their fibres expressed MHC-1 (100% of total fibres) and MHC-2 (45-50%) in the same way. Moreover, the masses of regenerating and nonregenerating soleus were significantly increased by physical exercise (P < 0.02). At 9 days no effect of muscular exercise was found. In conclusion, endurance exercise did not alter differentiation of regenerating soleus. Moreover regenerating soleus can respond to increased physical activity by enhancing its mass in the same way as mature muscle.

Relationships between plasma thyrotropin receptor antibodies and lipid or lipoprotein parameters in Graves' disease

Functional thyrotropin receptors (TSH-R) have recently been detected in fat cells but not in liver cells from rat, and it seems that in infant adipocytes stimulatory TSH-R antibodies (TSH-R-ab) act through this receptor pathway, resulting in increased triglyceride catabolism. We investigated the relationships between plasma TSH-R-ab and free thyroxine (FT4) levels and plasma lipid or lipoprotein values in 49 untreated adult women with Graves' disease, all positive for these antibodies. A simple positive correlation (p < 0.01) was found between TSH-R-ab levels and FT4 values (r = 0.40). Simple positive correlations (p < 0.001) were found between triglyceride levels and FT4 (r = 0.51) or TSH-R-ab (r = 0.52) values. Multiple regression analysis confirmed that both FT4 and TSH-R-ab are strong (p < 0.005) predictors of triglyceride (FT4: partial r = 0.40; TSH: partial r = 0.39). Simple negative correlations (p < 0.05, at least) were found between FT4 levels and total cholesterol (TC) (r = -0.45), low-density lipoprotein (LDL)-C (r = -0.46), apoprotein (apo)-B (r = -0.31) or high-density lipoprotein (HDL)-C (r = -0.55) values. Among these lipid parameters, only HDL-C levels (r = -0.31, p < 0.05) correlated to TSH-R-ab values. However, multiple regression analysis revealed that while FT4 is a strong predictor (p < 0.005) of TC (partial r = -0.42), LDL-C (partial r = -0.43) or HDL-C (partial r = 0.47), TSH-R-ab are not. Thus, the apparent positive relationship between TSH-R-ab and HDL-C results from the positive correlation between TSH-R-ab and FT4. In conclusion, this study suggests that stimulating TSH-R-ab are involved in triglyceride metabolism. In contrast to thyroid hormones, these antibodies seem not to be related to cholesterol metabolism.

[Cardiovascular risks during isokinetic tests for peripheral functional studies]

OBJECTIVES

Isokinetic tests used to assess both muscle function and joint disorders stimulate the entire organism and in particular the cardiovascular system. We evaluated the risk of cardiovascular or vascular impairment during isokinetic knee extension and flexion tests.

METHODS

Cardiac electrical activity, heart rate and systolic and diastolic blood pressures were measured in 251 patients during 50-sec isokinetic tests.

RESULTS

Abnormal findings were recorded in 15 patients (5.9%) including 6 with altered blood pressure, 4 with altered cardiac electrical activity and 5 with heart rate abnormalities. Maximal heart rate for a given subject recorded during the isokinetic test was 199 beats per minute and heart rate exceeded 190 bpm in 92 subjects (36.6%). Maximal efforts with cardiac barometric charge produced dramatic, occasionally pathological, changes in heart rate or blood pressure.

CONCLUSION

These findings emphasize the need to carefully assess patients before isokinetic tests and carefully monitor cardiovascular parameters. A preliminary physical examination and medical surveillance during testing are required.

Effect of physical exercise on adoptive experimental auto-immune encephalomyelitis in rats

The aim of the study was to determine whether different programmes of exercise influence adoptive monophasic experimental auto-immune encephalomyelitis (adoptive EAE), a paralytic disease mediated by T-cells. Adoptive EAE was induced by the transfer of activated encephalitogenic T-lymphocytes into syngeneic recipients (Lewis rats, n = 85) and its development was followed by two independent observers. The results showed that 2 days of severe exercise (250 and 300 min) performed after the adoptive transfer of EAE slightly delayed the onset of the disease (P <0.008) and the day of its maximal severity (P <0.016) without affecting the overall severity of the disease. When this programme of exercise was performed before the cell transfer, it had no effect (P > 0.05). Two more moderate exercise programmes (5 x 120 min of running at constant speed or 5 x 60 min of running at variable speed, 5 consecutive days) performed between the adoptive transfer and the onset of the disease did not modify the development of the clinical signs of adoptive EAE (P >0.05). These results showed that severe exercise slightly influenced the effector phase of monophasic EAE and confirmed that physical exercise performed before the onset of experimental auto-immune diseases did not exacerbate the clinical signs.

Relationship of antibodies to thyrotropin receptors and to thyroid ultrasonographic volume in euthyroid and hypothyroid patients with autoimmune thyroiditis

It has been reported in hypothyroid patients with Hashimoto's thyroiditis and in patients with primary myxoedema that antibodies (Ab) to the TSH-receptor (R), which inhibit the thyroid gland, decrease both thyroid hormonogenesis and cell growth in vitro. We investigated, in 169 newly diagnosed patients with euthyroid (n = 83) or hypothyroid (n = 86) autoimmune thyroiditis, the relationship between thyroid autoimmunity expression and thyroid ultrasonographic volume or thyroid hormonal status. In patients positive for TSH-receptor (R) antibodies (Ab), negative correlations (P < 0.01) were found between TSH-R Ab levels and free T4 (FT4) values in a euthyroid (r = -0.63), as well as in a hypothyroid (r = -0.54) state, and between TSH-R Ab and total thyroid volume (TTV) values in an euthyroid (r = -0.62) as well as in a hypothyroid (r = -0.53) state. In contrast, no positive correlations were found between TSH levels and FT4 values or TTV levels in patients positive as well as negative for TSH-R Ab in an euthyroid or in a hypothyroid state. These data demonstrate in vivo, that, in contrast to TSH, TSH-R Abs are related to both thyroid hormonal production and volume in euthyroid or hypothyroid patients with autoimmune thyroiditis.

Solitary skin metastasis as the presenting feature of differentiated thyroid microcarcinoma: report of two cases

Cutaneous metastases from thyroid neoplasia are very rare. Most patients presenting with such a disease have also both internal metastases and a very enlarged thyroid gland. We reported here 2 patients presenting with differentiated thyroid microcarcinoma which was revealed by a solitary scalp lesion. The positive immunoperoxidase staining for thyroglobulin (TG) in the skin tumour cells asserted the diagnosis of metastatic thyroid carcinoma. The thyroid neoplastic micronodular formation was unrecognized by ultrasonography and it was only found at serial histological examination of the thyroid gland entirely removed during surgery. Histological procedure showed a solitary follicular microcarcinoma (diameter = 0.5 cm) in 1 patient, and two differentiated microcarcinoma, a follicular microcarcinoma (diameter = 0.4 cm) in a lobe and a follicular-papillary carcinoma (diameter = 0.5 cm) in the other lobe, in the second patient.

[Role of physical activities in a public health policy]

A gradual decrease in energy output for adults in the Western countries has been observed through the XXth century. The mechanization in industrial societies result in a decline of customary physical activity and consequently in the potentially vicious spiral of inactivity leading to deconditioning and thence, via loss of physiological capacity, to a further reduction in activity. The sedentary life has injurious effects on the health of individuals and specially increase the risks of cardiovascular disease. Furthermore there is a supposed relation between inactivity with obesity and hyperlipemia in young people and with osteoporosis in elderly. In contrast, many papers showed that high levels of physical activity have been associated with a diminished occurrence of hypertension, coronary artery disease, non insulin-dependent diabetes, colon cancers... In addition physical fitness is obviously related to the quality of life. Because of all these reasons several developed countries have elaborated plans of physical reconditioning for their people. In France some experimental actions have been completed but any national programme has been determined. Moreover it is now crucial to promote scientific researches about the fundamental biological mechanisms which explain the beneficial effects of physical training on the prevention and/or the treatment of several illness.

Testicular steroidogenesis in adult men with human chorionic gonadotropin-producing tumors

There are few critical studies on plasma testosterone (T) and 17 beta-estradiol (E2) levels in men with hCG-producing tumors, and the results are contradictory. Plasma E2 levels are most often elevated, whereas plasma T values are high or in the normal range. We studied the plasma levels of such steroids and of delta 4 and delta 5 T precursors in adult men with intact hCG-producing tumors to evaluate the relationship between hCG and steroid hormone levels or steroidogenic enzyme activities. Ten adult men with hCG-producing tumors and 25 normal adult men were investigated. Seven men with testicular tumors were studied before and after hemicastration. The 2 patients with extratesticular tumors were investigated before and during chemotherapy. The remaining patient was studied every 2 months for 1 yr during the spontaneous course of the disease. Plasma progesterone (P), 17 alpha-hydroxyprogesterone (17-OHP), androstenedione (A), 17-hydroxy-delta 5-pregnenolone (17-OH delta 5-P), dehydroepiandrosterone (DHEA), T, E2, and hCG were measured, and ratios of steroid levels were also calculated. In patients with increased hCG values (i.e. > 5 IU/L), the mean plasma P, 17-OHP, A, 17-OH delta 5-P, DHEA, T, and E2 levels were higher (P < 0.01 at least) than those in patients whose hCG values were normalized or in controls. The patterns of these steroids were very different according to plasma hCG levels. Indeed, for hCG levels between more than 5 and 3.5 x 10(3) IU/L, positive correlations (P < 0.05 at least) were found between hCG levels and delta 4 T precursor, delta 5 T precursor, T, or E2 values. Conversely, for hCG values greater than 3.5 x 10(3) IU/L, hCG levels were negatively correlated (P < 0.05 at least) to all steroid values. Furthermore, in patients with increased hCG levels, the mean plasma P to 17-OHP ratio, 17-OHP to A ratio, A to T ratio, 17-OHP to T ratio, and 17-OH delta 5-P to DHEA ratio were similar to those in patients with normalized hCG values or in controls. In contrast, in patients with increased hCG levels, the mean plasma T to E2 ratio value was lower (P < 0.001) than that in patients with normalized hCG levels or in controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Prevalence of sporadic medullary thyroid carcinoma: the importance of routine measurement of serum calcitonin in the diagnostic evaluation of thyroid nodules

OBJECTIVE

The prevalence of sporadic forms of medullary thyroid carcinoma (MTC) has been studied in patients living in an area of moderate iodine deficiency. Such forms of MTC are usually diagnosed after surgery and have little chance of definitive cure. Using the measurement of basal serum calcitonin (CT) levels in a large series of patients with both thyroid disease and normal 24-hour urinary iodine excretion, we assessed the prevalence of MTC and, in patients affected with the disease, we also evaluated the stage of the disease according to surgical findings and post surgical plasma CT levels.

PATIENTS

A prospective study of 657 patients with thyroid disease (469 with nodular and 188 with non-nodular thyroid disease). As controls, 40 normal subjects were also studied.

MEASUREMENTS

In all patients: (1) measurement of basal serum CT, free T4, total T3, TSH levels and serum TSH-receptor, peroxidase and thyroglobulin (Tg) antibody concentrations, (2) thyroid ultrasonography, (3) fine needle aspiration cytology (FNAC). In patients with increased basal CT levels: (1) measurement of serum CT levels during pentagastrin test prior to surgery, (2) histological examination and immunostaining with both anti-CT and anti-Tg antibodies of all the nodular thyroid tissue surgically removed, (3) measurement of basal and pentagastrin stimulated serum CT values after surgery.

RESULTS

All the patients with non-nodular thyroid disease had normal basal CT levels. Four patients (0.84%) with nodular thyroid disease (2 with uninodular and 2 with multinodular goitre) had both elevated basal and pentagastrin stimulated CT levels. In the two patients with uninodular goitre, FNAC was suggestive of MTC in 1 (nodular diameter 8.0 cm) and of follicular carcinoma in 1 (nodular diameter 2.5 cm). Histological examination of the nodules confirmed these histotypes. Immunostaining with anti-CT antibodies was positive in the former patient but also in the latter. FNAC was suggestive of benign adenomatous tissues in the two patients with multinodular goitre. Histological examination of all the thyroid nodules confirmed the cytological findings. However, serial sections through the gland in each of these two patients showed an occult follicular carcinoma which had, however, positive staining with anti-CT antibodies. Furthermore, immunostaining with anti-Tg antibodies was negative in the patient with MTC but positive in the 3 patients with follicular carcinoma. Finally, both basal and pentagastrin stimulated CT levels remained elevated after total thyroidectomy only in the patient with FNAC suggesting MTC.

CONCLUSIONS

This study demonstrates a surprisingly high prevalence of sporadic forms of medullary thyroid carcinoma in patients with nodular thyroid disease. Such forms of medullary thyroid carcinoma seem to be unrelated to iodine intake and may be pure or mixed with a follicular carcinoma. In these mixed thyroid carcinomas, only the neoplastic follicular pattern was seen on both cytological and histological examination. Routine measurements of serum calcitonin levels should therefore be considered an integral part of the diagnostic evaluation of thyroid nodules. Indeed, increasing the accuracy of diagnosis of medullary thyroid carcinoma encourages the surgeon to perform more radical treatment, thus achieving more frequent normalization of post-operative serum calcitonin levels.

Effects of thyroid status on thyroid autoimmunity expression in surgically induced hypothyroid patients with Graves' disease

We investigated, in 20 patients with Graves' disease and presenting with both a surgically induced hypothyroid state and increased serum antibodies (Ab) to the TSH receptor (R) levels, the relationships between thyroid status and the serum TSH-R or peroxidase (TPO) Ab levels under L-T4 treatment and after L-T4 cessation. The prevalence of positive TSH-R Ab (100%) and the log mean TSH-R Ab level (1.41 +/- 0.04%) observed during the surgically induced hypothyroid state decreased (p < 0.001, p < 0.01, respectively) under L-T4 therapy (prevalence of positive TSH-R Ab = 50%, log mean TSH-R Ab level 1.21 +/- 0.05%) and increased again (p < 0.001) after L-T4 cessation (prevalence of positive TSH-R Ab = 85%, log mean TSH-R Ab level = 1.45 +/- 0.06%) to reach levels lower (< 0.01) than that observed during the hypothyroid state for prevalence of positive TSH-R Ab but similar to that obtained during such a state for log mean TSH-R Ab value. The log mean TPO Ab level obtained during the surgically induced hypothyroid state (3.2 +/- 0.5 titer) decreased (p < 0.02) under L-T4 therapy (1.8 +/- 0.2 titer) and increased again (p < 0.02) after L-T4 cessation (3.0 +/- 0.5 titer) to reach a similar level to that obtained during the surgically induced hypothyroid state. There were positive correlations between log TSH levels and log TSH-R Ab values (r = 0.40, p < 0.001) or log TPO Ab levels (r = 0.33, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for the effect of antibodies to TSH receptors on the thyroid ultrasonographic volume in patients with Graves' disease

OBJECTIVE

It has been demonstrated that antibodies (Ab) to thyroid-stimulating hormone receptors (R), which stimulate the thyroid gland, induce hyperthyroidism in patients with Graves' disease. Furthermore, it has been shown in thyroid cells in culture that thyroid-stimulating hormone receptor Ab acts through the adenosine 3', 5'-monophosphate pathway which stimulates both thyroid hormonogenesis and growth. We investigated the relations between thyroid autoimmunity expression and thyroid ultrasonographic parameters or thyroid hormonal status in patients with Graves' disease.

PATIENTS

A prospective study of 53 consecutive patients referred with untreated Graves' disease.

MEASUREMENTS

Measurements were made of serum TSH-R, peroxidase (TPO) and thyroglobulin (Tg) Ab and basal plasma free T4 (FT4), free T3 (FT3) and TSH. Thyroid morphological characteristics (number and total volume of nodule(s), total volume of lobes and total thyroid volume) were determined by ultrasonography.

RESULTS

There were significant correlations (P < 0.001) between TSH-RAb levels and FT4 values (r = 0.48) or FT3 levels (r = 0.46). Likewise, significant correlations were found between TSH-RAb levels and total lobe volume values (r = 0.56, P < 0.001), total nodular volume values (r = 0.59, P < 0.01) or total thyroid volume values (r = 0.63, P < 0.001). By contrast, no correlation was found between TSH-RAb levels and the number of nodules or between any of the ultrasonographic parameters and TPOAb levels or TgAB values.

CONCLUSIONS

This study demonstrates, in vivo, that TSH receptor antibodies modulate the thyroid ultrasonographic extranodular and nodular volumes in patients with Graves' disease.

Effect of muscular exercise on chronic relapsing experimental autoimmune encephalomyelitis

We examined whether physical exercise affected the development of an autoimmune response, experimental autoimmune encephalomyelitis (EAE), which is a demyelinating disease leading to paralysis. EAE was inducted on day 0, in rats of both sexes, by injecting them with spinal cord tissue in adjuvant. From days 1 to 10 after injection, exercised rats (n = 55) ran on a treadmill (60-120 min/day) before the onset of the paralytic disease. Clinical signs of the disease (ataxia, paralysis, and body mass loss) were examined in exercised and control rats (n = 54). Three types of EAE were induced: monophasic, acute, and chronic relapsing (CR)-EAE (3 bouts of disease, CR-EAE 1, 2, and 3, separated by remissions). Exercise significantly delayed the onset of CR-EAE 1 (P = 0.001) and the 1st day of maximum severity of CR-EAE 1 (P = 0.001) and CR-EAE 2 (P = 0.002). Moreover, the duration of CR-EAE 1 was significantly decreased in exercised rats compared with control rats (P = 0.004). The peak severity of the different types of EAE was not modified by exercise. The present study indicates that endurance exercise during the phase of induction of EAE diminished lightly only one type of EAE (CR-EAE) and therefore did not exacerbate the autoimmune disease.

Effects of thyroid status on thyroid autoimmunity expression in euthyroid and hypothyroid patients with Hashimoto's thyroiditis

OBJECTIVE

In patients with hypothyroid goitrous Hashimoto's thyroiditis, the recovery from hypothyroidism seems to be due to a spontaneous decrease of antibodies (Ab) to the TSH-receptor (R). In contrast, in patients with Graves' disease made euthyroid by antithyroid drug therapy, the suppression of TSH secretion by thyroid hormone during antithyroid drug treatment decreases the production of Ab to TSH-R. We investigated in patients with initially euthyroid or hypothyroid goitrous Hashimoto's thyroiditis the relationships between thyroid status and the serum TSH-R, peroxidase (TPO) and thyroglobulin (Tg) Ab concentrations in untreated or L-thyroxine (T4) treated patients.

PATIENTS

A prospective study of 174 consecutive patients, referred with goitrous Hashimoto's disease in an initially euthyroid (group I, n = 78) or hypothyroid (group II, n = 96) state. The patients with positive (> or = 7%) TSH-RAb (group I, n = 18; group II, n = 22) were reinvestigated 12 months after the initiation of L-T4 therapy. After which, (1) L-T4 was continued and an evaluation performed 2 months later (i.e. 14 months after L-T4 initiation) in 9 patients of group I and in 11 patients of group II or (2) L-T4 was withdrawn and an evaluation performed 2 months later in 9 patients of group I and in 11 patients of group II.

MEASUREMENTS

Measurements of basal plasma TSH, free T4 (FT4) and total T3 and serum TSH-R, TPO and TgAb.

RESULTS

The prevalence of positive TSH-RAb levels did not differ between group I (23.1%) and group II (22.9%). However, the mean TSH-RAb level in group I (9.4 +/- 0.4%) was lower (P < 0.01) than in group II (11.6 +/- 0.5%). In the patients with positive TSH-R Ab, (1) the prevalences of positive TSH-RAb decreased (P < 0.001) under L-T4 therapy (group I = 22.2%, group II = 21.2%) and increased again (P < 0.01) 2 months after L-T4 cessation (group I = 77.7%, group II = 63.6%) to reach lower levels (group I, P < 0.05; group II, P < 0.01) than those obtained prior to L-T4 treatment. Statistical analysis of TSH levels through the course of the study confirmed these results. (2) In contrast to the variations of the mean TgAb values, the variations of the mean TPOAb levels in each group were in good agreement with those of TSH-RAb through the course of the study. (3) There were significant correlations between some parameters of thyroid status and both TSH-RAb (TSH, r = 0.43, P < 0.001; FT4, r = -0.35, P < 0.01) and TPOAb (TSH, r = 0.42, P < 0.001; FT4, r = -0.31; P < 0.01) levels. In contrast, no correlations were found between thyroid status and TgAb values.

CONCLUSIONS

This study demonstrates that thyroid status can modulate thyroid autoimmunity expression, such as TSH-RAb and TPOAb, in patients with euthyroid or hypothyroid goitrous Hashimoto's thyroiditis. Similar results have been reported in patients with Graves' disease made euthyroid by the administration of thyroid hormone during antithyroid drug treatment.

Sex as a determining factor in the effect of exercise on in vivo autoimmune response adjuvant arthritis

The present study was conducted to examine the effect of physical exercise on the development of adjuvant arthritis (AA), an animal model of the human rheumatoid arthritis, which is a T-cell-dependent autoimmune response. AA was inducted on day 0 in 8-wk-old Lewis rats of both sexes. Between postinjection days 1 and 12, two groups of rats (male and female) were trained on a treadmill every day (45-120 min/day and 15-30 m/min) before the onset of arthritic disease. Trained female (n = 27) and male (n = 22) rats and control female (n = 29) and male (n = 17) rats were observed every 2 days for the following clinical signs of AA: number of arthritic joints (swelling and redness), paw thickness, and weight gain during the disease. The results show that the incidence of arthritis (% of arthritic rats) was significantly higher in trained female rats (74%; P < 0.03) and significantly lower in trained male rats (27%; P < 0.05) compared with control rats of both sexes (female, 45%; male, 59%). There was no difference in the severity and development of the disease between trained rats and control rats of both sexes (P > 0.05). The present study indicates that the effect of exercise on the incidence of AA, an in vivo autoimmune response, depends on the sex of the animal.