The seeds of invasion: enhanced germination in invasive European populations of black locust (Robinia pseudoacacia L.) compared to native American populations.

Local adaptation and the evolution of phenotypic plasticity may facilitate biological invasions. Both processes can enhance germination and seedling recruitment, which are crucial life-history traits for plants. The rate, timing and speed of germination have recently been documented as playing a major role during the invasion process. Black locust (Robinia pseudoacacia L.) is a North American tree, which has spread widely throughout Europe. A recent study demonstrated that a few populations are the source of European black locust. Thus, invasive populations can be compared to native ones in order to identify genetic-based phenotypic differentiation and the role of phenotypic plasticity can thereby be assessed. A quantitative genetics experiment was performed to evaluate 13 juvenile traits of both native and invasive black locust populations (3000 seeds, 20 populations) subjected to three different thermal treatments (18 °C, 22 °C and 31 °C). The results revealed European populations to have a higher germination rate than the native American populations (88% versus 60%), and even when genetic distance between populations was considered. Moreover, this trait showed lower plasticity to temperature in the invasive range than in the native one. Conversely, other studied traits showed high plasticity to temperature, but they responded in a similar way to temperature increase: the warmer the temperature, the higher the growth rate or germination traits values. The demonstrated genetic differentiation between native and invasive populations testifies to a shift between ranges for the maximum germination percentage. This pattern could be due to human-mediated introduction of black locust.

[Relevance and experience of surveillance and brief contact intervention systems in preventing reattempts of suicide among children and adolescents]. / Pertinence et expérience des dispositifs de veille et de recontact dans la prévention suicidaire auprès des enfants et des adolescents.

In France, one adolescent out of ten has already attempted suicide. In this population, suicide reattempts are frequent and significantly impact the vital, morbid and functional long-term prognosis. For about fifteen years, surveillance and brief contact intervention systems (SBCIS) have been used to complete the French suicide reattempt prevention arsenal for youth. The relevance of such strategy appears once the mental health service gap observed at this period of life is considered. In addition to prompting better coordination between the different professional stakeholders, the SBCIS help to alleviate the adolescent's help-seeking barriers, especially the ambivalence between conquest of autonomy and need for help. The first results from the French SBCIS dedicated to children and adolescents are encouraging. Although they have to deal with specific challenges, we argue that they relevantly complement and potentiate the already available prevention resources, thus optimizing the whole prevention system for suffering youth.

[Evolution and follow-up of hunger strikers: experience from an interregional hospital secured unit]. / Évolution et surveillance des patients grévistes de la faim : expérience d'une unité hospitalière sécurisée interrégionale.

PURPOSE: A hunger strike is a voluntary fast, performed to protest publicly against an issue deemed unfair. In the case of French prisoners, hospitalization in an interregional hospital secured units (UHSI) may be necessary. METHODS: A retrospective epidemiological study based on one UHSI medical records was performed on the period of May, 2006 to December, 2008, and focused on symptoms, outcomes and ethical problems encountered. RESULTS: Seven men and one woman with a mean age of 32.6 years were hospitalized in an UHSI, with nine episodes of hunger strike of a median duration of 57 days. Clinical symptoms began after two weeks of voluntary deprivation in the form of dizziness, weakness, muscle pain and headache. Laboratory tests showed hypoglycemia (<0.4g/L) on admission, 16.3% decrease of albumin after 40.5 days, and dehydration in case of thirst strike. The clinical tolerance was good and no patient presented Wernicke's encephalopathy. A diabetic patient developed acidocetosis during two hunger strikes. All hunger strikes were respected by medical staff, and treatment was based upon surveillance of symptoms, vitamin B and sweetened drinks administration and explanations of the clinical hazards on a daily basis. CONCLUSION: The special problem encountered in the medical management of these strikers was to convince them to accept treatments in order to avoid a coercive life-saving treatment as requested by French law.

Seasonal and interannual variations in carbon isotope discrimination in a maritime pine (Pinus pinaster) stand assessed from the isotopic composition of cellulose in annual rings.

Stable carbon isotope composition (delta; per thousand) was measured on cellulose extracted from maritime pine (Pinus pinaster Aït.) tree rings to investigate inter-tree and interannual variability (7 trees, 20 rings per tree, each ring divided into early and late wood). A model of stand primary production coupled to water balance was used to calculate the stand annual water-use efficiency (WUE). Inter-tree variability in discrimination (maximum 2.88 per thousand in late wood in 1989, 2.69 per thousand in early wood in 1983) was as large as interannual variation (maximum 2.72 per thousand in late wood, 2.05 per thousand in early wood). Tree size did not explain these differences. Relationships were found between annual discrimination and climate variables such as annual rainfall, summer temperature and vapor pressure deficit (VPD). Higher correlations were found with late wood discrimination. Early wood discrimination was shown to be related to previous-year late wood discrimination. Late wood discrimination was also related to soil water availability. Stand annual WUE was only weakly related to tree ring carbon discrimination.

[Constitutional anomalies of hemostasis and management in surgical situation. Evaluation of 10 years' activity at the Hospital Centers of Aulnay-sous-Bois and Saint-Denis]. / Anomalies constitutionnelles de l'hémostase et conduite à tenir en situation chirurgicale. Bilan de dix ans d'activité aux Centres Hospitaliers d'Aulnay-sous-Bois et de Saint-Denis.

A ten-year retrospective study was conducted in 4 women in labor and 23 surgical patients with congenital clotting factor deficiency. Appropriate use of replacement therapy and good cooperation between biologists, anesthesiologists, and surgeons are essential to ensure a favorable outcome.

Functional outcome of upper limb tendon transfers performed in children with spastic hemiplegia.

Children with spastic hemiplegia often present with upper limb muscle imbalance. The purpose of this paper was to determine whether reconstructive surgery improved their functional ability. 17 children under the age of 16 years with spastic hemiplegia underwent reconstruction that included tendon transfers, tendon lengthenings and thumb metacarpophalangeal fusion. They were assessed pre-operatively and at an average follow-up period of 2.6 years. Children's abilities were classified according to House's functional rating scale. Tendon transfers improved functional grading by two grades, from good passive assist to fair active assist. Improvement in the arc of wrist motion and forearm rotation was also seen. Parental satisfaction was high. Reconstructive surgery improved the functional abilities in this group of children with spastic hemiplegia.

The anatomy and treatment of camptodactyly of the small finger.

Having observed an anomalous insertion of the lumbrical muscle in 74 consecutive operations for correction of camptodactyly of the small finger, we have concluded that the loss of normal lumbrical action is the principal cause of the intrinsic minus deformity seen in this condition. Other anatomic abnormalities observed in this series of patients are those of the superficial tendon in 47%, the x-ray appearance of the proximal interphalangeal (PIP) joint in 15%, and a fixed flexion contracture of the PIP joint in 66%. Fifty-seven percent of our patients had PIP flexion contracture of more than 45 degrees. To determine the contribution of these anomalies to this deformity, we analyzed a series of 53 patients who had been followed up for at least 1 year. The study revealed that these conditions are interdependent and that each had an adverse effect on the final operative results. Treatment included a transfer of the superficial tendon of the ring or little finger to the extensor mechanism of the little finger in all cases and other procedures as dictated by the individual situation. Overall, the joint contracture was reduced from 49 degrees to 25 degrees, but only 33% of the patients regained full flexion of the small finger.

Early bronchopulmonary lesions in rat lung after normobaric 100% oxygen exposure and their evolution. A light and electron microscopic study.

In order to clarify the early phenomena involved in the lung reaction to hyperoxia, twenty adult male rats were exposed to 100% oxygen at 1 ATA. Morphological pulmonary lesions were detectable after only 24 h hyperoxia, and included vasoconstriction and perivascular oedema, bronchiolar constriction, and pericyte reaction. The lesions were irregularly scattered within the lung parenchyma and occurred preferentially in areas centred on bronchiolo-vascular stems. Even at the latest stages, pulmonary heterogeneity was obvious, from the coexistence of areas damaged at different times. Neuro-epithelial-bodies were found under the bronchiolar epithelium; the morphological aspect of the neuro-endocrine cells observed was consistent with hyperoxia-induced modulation of their secretory activity. Taken together, our findings show the speed of development of hyperoxia-induced pulmonary changes and raise some pathogenic considerations.

Autoradiographic localization of binding sites for oxytocin and vasopressin in the rat kidney.

The distribution of [3H]vasopressin- and [3H]oxytocin-binding sites was examined, using an autoradiographical technique, in the kidney of Long-Evans and Brattleboro rats. Two types of binding sites with affinities in the nanomolar range were detected: one, located on glomeruli, bound both vasopressin and oxytocin; the other, on collecting ducts, bound vasopressin selectively. In the presence of 10 mumol oxytocin/l, [3H]vasopressin labelling was abolished in glomeruli, but only reduced in collecting ducts; [3H]oxytocin labelling was completely abolished by 10 mumol vasopressin/l. These observations are discussed in relation to known effects of neurohypophysial hormones on renal physiology.

Pharmacological characteristics and anatomical distribution of [3H]oxytocin-binding sites in the Wistar rat brain studied by autoradiography.

Oxytocin-binding sites were detected by autoradiography on rat brain sections incubated in the presence of the [3H]oxytocin. These sites were characterized pharmacologically using quantitative autoradiography. High pressure liquid chromatography controls of the incubation media indicated that labelling was due to the intact [3H]oxytocin molecule. Pharmacological analysis of different locations (central amygdaloid nucleus, ventral subiculum and ventromedial hypothalamic nucleus) showed that the sites detected had a high affinity for oxytocin and also for arginine-vasopressin. In contrast, some areas known to bind vasopressin intensely, such as suprachiasmatic and lateral septum nuclei, had little or no affinity for oxytocin. Autoradiographs revealed [3H]oxytocin-binding sites in already known brain areas (olfactory centres, ventral subiculum, central amygdaloid nucleus, bed nucleus of the stria terminalis) albeit with more extensive labelling of some of these formations, in particular, the amygdaloid complex. In addition, specific [3H]oxytocin-binding sites were found in areas not yet reported to bind oxytocin, such as the paraventricular thalamic and caudate nuclei. In the hypothalamus, specific binding sites were not detected in the supraoptic and paraventricular nuclei: the only structure labelled was the ventrolateral part of the ventromedial nucleus. Discrepancies between the concentrations of [3H]oxytocin-binding sites, the known distribution of oxytocin-containing endings and electrophysiological data indicate that autoradiography, under our conditions, apparently only reveals some of the oxytocin receptors in the brain. Thus, in the hypothalamus, no relationship can be established between the known effect of oxytocin on oxytocinergic magnocellular neurons and detection of specific [3H]oxytocin-binding sites. Autoradiography may reveal mainly oxytocin-binding sites in areas receiving diverse "parasynaptic" information, where oxytocin might play a modulatory role rather than exerting rapid, short-term effects of the neurotransmitter type.

Light and electron microscopic structure of the cardiac Purkinje fibers--review.

The history and the morphological characteristics of the Purkinje fibers are reviewed briefly in different species and in the atrioventricular (A-V) bundle branches (BB) of the same species. The so-called typical Purkinje fibers corresponding to the original description are found in birds, ungulates, and larger mammals. The specialized fibers of the ventricular impulse conduction are present, however, in all mammals and are distinguishable with new and reviewed morphological methods from the force-producing fibers. The Purkinje fiber term is applicable for all the BB fibers, which, by their morphology, might be classified in man and small mammals as Purkinje I (proximal BB), II (ramified BB), and III (terminal) fibers. The main characteristics of the Purkinje fibers are: cable-like structure in birds, ungulates, and proximal BB fibers of other mammals; lack of transverse tubular system; generally little contractile material associated with a high number of intermediate filaments; few mitochondria and low mitochondrial enzyme activity; high amount of glycogen and anaerobic ability rendering them relatively resistant to hypoxia. The distribution of the Purkinje net-work and the modes of Purkinje and ventricular fiber interconnections are also reviewed.

Dopamine D2 receptors are restricted to the prolactin cells in the rabbit pituitary gland: a combined autoradiographic and immunocytochemical study.

The distribution of dopamine D2 receptors was studied using the autoradiographic technique on rabbit pituitary gland sections incubated in the presence of [3H]spiroperidol. D2 receptors were absent from the intermediate lobe as already reported. In the anterior lobe, the location of D2 receptors exactly overlapped that of the prolactin-producing cells revealed by immunocytochemistry on the sections used for autoradiography. No topographical relationships could be found between the D2 receptors and the TSH-producing cells which are known to be inhibited by dopamine in the rat.

Absence of inhibitory dopaminergic control of the rabbit pituitary gland intermediate lobe.

No immunoreactive axons were detected with an antiserum against tyrosine hydroxylase in the rabbit intermediate lobe (IL), which thus appears to be devoid of dopaminergic (DA) innervation. Dopamine and its agonists, which classically inhibit alpha-MSH release have no inhibitory effects on rabbit IL superfused in vitro but, paradoxically, stimulate alpha-MSH release. D2 type DA receptors, known to mediate inhibitory control of dopamine on melanotropic cells, and detectable by their affinity for (3H)-spiroperidol, were as previously reported absent from the rabbit IL. The absence of (3H)-spiroperidol binding sites in the IL was further confirmed on rabbit pituitary sections by radioautography. The mechanism of DA stimulation is still not clear, but might be tentatively explained by interference with other receptors involved in the stimulation of the gland. The lack of DA inhibitory control over the rabbit IL is an exception among the species so far studied.

Opposite effects of monosodium glutamate on the dopaminergic and GABAergic innervations of the median eminence and the intermediate lobe in the mouse.

In the mouse, monosodium glutamate (MSG) administered neonatally provokes the necrosis of most dopaminergic perikarya in the arcuate nucleus, as classically described, but also stimulates surviving neurons as shown by their increase in both size and immunoreactivity for tyrosine hydroxylase (TH). In the treated animals, TH-immunoreactive axons rarefy in the median eminence (ME) external zone, but postnatal dopaminergic innervation of the intermediate lobe (IL) normally develops and even, due to enlarged axonal varicosities, is more conspicuous than in the control littermate IL at same stages. gamma-Aminobutyric acid-ergic (GABAergic) projections in the ME and the IL, revealed with a glutamic acid decarboxylase antiserum, have the same distribution as TH-immunoreactive axons and present the same modifications in the MSG-treated animals. No clearcut differences in dopaminergic and GABAergic innervation patterns can be observed in the IL in treated and control adult mice.

[Stimulatory control by oxytocin (or an analog peptide) of the pituitary intermediate lobe in rabbits. Inhibitory role of serotonin]. / Contrôle stimulant par l'ocytocine (ou un peptide analogue) du lobe intermédiaire de l'hypophyse chez le lapin. Rôle inhibiteur de la sérotonine.

The peculiar innervation of the intermediate lobe (IL) in Leporidae obviously corresponds to a regulation mechanism different from that known in other mammals. Physiological observations on IL superfused in vitro show, in addition to the previously reported absence of dopaminergic inhibitory control, the existence of an oxytocinergic-like control involved in the stimulation and not in the inhibition of alpha MSH release by the rabbit IL. Serotonine has inhibitory effects and may play a modulatory role. However, the strong stimulation of alpha MSH release obtained with K+ at a depolarizing concentration (8K) suggests that the presence of any powerful inhibitory axonal system in the rabbit IL is rather unlikely.