Suites of plant traits in species from different stages of a Mediterranean secondary succession.

The aim of this study was to detect suites of traits related to whole plant and seed morphology, phenology and resource use--including water--in species differing in successional status. Twenty traits were measured on 55 species representative of 5 successional stages in Mediterranean southern France, including eight pertaining to phenology and five to water economy. Suites of traits that changed along succession in agreement with the acquisition/conservation trade-off were completed by continuous changes in phenology. Early successional species had leaves with a high specific leaf area that were produced and lost continuously through the growing season. Late-successional species were taller with long-lived, high delta(13)C leaves produced during short periods, most of them persisting during summer, and produced large seeds requiring a long ripening period. Replacement of species occurred with change in strategies of drought survival: early successional species escaped drought by dying before summer; later herbaceous species maintained favourable water status in relation to leaf shedding during summer; late successional trees with a large body allowing access to a large pool of resources, produced dense leaves that could tolerate desiccation. These changes occurred concomitantly with a shift in CSR strategies, using traits related to resource use, plant size and flowering phenology: ruderal herbs were replaced by more stress-tolerant herbs and shrubs throughout the succession, with competitive trees dominating the latest successional stage. These results suggest that the breadth of functional variability found in natura is not predicted by the CSR framework, and calls for a more integrated view of whole plant functioning.

Zac1 is up-regulated in neural cells of the limbic system of mouse brain following seizures that provoke strong cell activation.

Zac1, a new zinc-finger protein that regulates both apoptosis and cell cycle arrest, is abundantly expressed in many proliferative/differentiation areas during brain development. In the present work, we studied Zac1 gene expression and protein in experimental seizure models following i.p. injection of pentylenetetrazole (PTZ) or kainic acid (KA). Following KA treatment, an early and intense up-regulation of Zac1 is detected in the limbic areas, such as the hippocampus, cortex and amygdaloid and hypothalamic nuclei. Pre-treatment with MK-801, an antagonist of the NMDA receptors, fully blocks the effect of KA in the hippocampus, whereas it only attenuates KA-induced Zac1 up-regulation in the other areas of the limbic system. A reduced induction is obtained with PTZ-treated animals, specifically in the entorhinal and piriform cortices as well as in amygdaloid and hypothalamic nuclei. Thus, Zac1 is highly induced in the seizure models that generate strong neuronal stimulation and/or extensive cell damage (cell death), reinforcing its putative role in the control of the cell cycle and/or apoptosis. Moreover, strong induction is observed in the granular cells of the dentate gyrus (which are resistant to neurodegeneration) and in some glial cells of the dentate gyrus and subventricular zone, suggesting that Zac1 may be implicated in the mechanisms of neural plasticity following injury.

Gonadotropin release in periovulatory heifers after GnRH analogs measured by two types of immunoassays.

This study on heifers (n = 27) compared the effects of a GnRH antagonist (Antarelix) and those of an agonist (Triptorelin) on gonadotropin release during the periovulatory period of the oestrous cycle. In three experiments (EXP I-III), an initial injection of GnRH analogs was given 48 h after a single PGF 2alpha pretreatment during the luteal phase, with a further five at 12 h intervals. A challenge by a GnRH agonist (Gonavet) was performed six hours after the last application of analogs. In EXP I (n = 9), heifers received six times 1.5 mg of Antarelix, 0.5 mg of Triptorelin, and mannitol (5%; control), respectively. In EXP II (n = 12), identical Antarelix and Triptorelin treatments were followed by a single injection of estradiol-17beta valerate (6 h after Gonavet). The dosage of Antarelix was increased to 5 mg for each injection in EXP III (n = 6). Measurement of LH in blood plasma frequently sampled was performed parallely by a competitive RIA method (EXP I + II) and by a sandwich-type electro-chemiluminescence-immunoassay (ECLIA) in EXP III. This non-isotopic technique was also used to additionally analyse FSH levels. Results of EXP I showed that the GnRH antagonist equally suppressed LH surges and ovulation. On the contrary, prior to suppression of LH levels due to down-regulation of pituitary GnRH receptors the agonist Triptorelin induced an initial increase in LH concentration which was followed by ovulation. In the control animals we observed endogenous LH surges as well as smaller elevations after the agonist (Gonavet) challenge. An increase was also observed in antagonist, but not in Triptorelin treated heifers. Pituitary GnRH receptors were not detectable in animals previously treated by the analogs, whereas concentrations between 2.2-21.0 fmol/mg protein were measured in controls. Results of EXP II confirmed the described effects of GnRH analogs. Additionally, it was shown that exogenous estradiol is able to release LH from the pituitary, although a previous treatment by a GnRH agonist had dropped the pulsatile gonadotropin secretion. Contrary to the LH pattern and despite elevated amounts of the antagonist, the mean concentration and pulse number of FSH were not influenced by the antagonist treatment (EXP III). These data confirmed that (a) the reversibly blocked pituitary function induced by a potent GnRH antagonist may be a useful tool to study gonadotropin-dependent final follicular growth as well as ovulation in cyclic heifers and (b) the novel non-isotopic ECLIA methods for the determination of FSH and LH provided practical alternatives to other immunoassay types.

Distinct pathways involved in sound recognition and localization: a human fMRI study.

Evidence from psychophysical studies in normal and brain-damaged subjects suggests that auditory information relevant to recognition and localization are processed by distinct neuronal populations. We report here on anatomical segregation of these populations. Brain activation associated with performance in sound identification and localization was investigated in 18 normal subjects using fMRI. Three conditions were used: (i) comparison of spatial stimuli simulated with interaural time differences; (ii) identification of environmental sounds; and (iii) rest. Conditions (i) and (ii) required acknowledgment of predefined targets by pressing a button. After coregistering, images were normalized and smoothed. Activation patterns were analyzed using SPM99 for individual subjects and for the whole group. Sound recognition and localization activated, as compared to rest, inferior colliculus, medial geniculate body, Heschl gyrus, and parts of the temporal, parietal, and frontal convexity bilaterally. The activation pattern on the fronto-temporo-parietal convexity differed in the two conditions. Middle temporal gyrus and precuneus bilaterally and the posterior part of left inferior frontal gyrus were more activated by recognition than by localization. Lower part of inferior parietal lobule and posterior parts of middle and inferior frontal gyri were more activated, bilaterally, by localization than by recognition. Regions selectively activated by sound recognition, but not those selectively activated by localization, were significantly larger in women. Passive listening paradigm revealed segregated pathways on superior temporal gyrus and inferior parietal lobule. Thus, anatomically distinct networks are involved in sound recognition and sound localization.

Expression control and specificity of the basic amino acid exporter LysE of Corynebacterium glutamicum.

LysE of Corynebacterium glutamicum belongs to a large new superfamily of translocators whose members are probably all involved in the export of small solutes. Here, the transcript initiation site of lysE, and its divergently transcribed regulator gene, lysG, are identified. Single-copy transcriptional fusions of lysE with lacZ, and titration experiments, show that LysG is the positive regulator of lysE expression enabling its up to 20-fold induction. This induction requires the presence of a coinducer, which is either intracellular L-lysine, or L-arginine. A competition experiment showed that LysE exports these two basic amino acids at comparable rates of about 0.75 nmol min(-1) (mg dry wt)(-1). Although L-histidine and L-citrulline also act as coinducers of lysE expression, these two amino acids are not exported by LysE. As is evident from the analysis of a lysEG deletion mutant, the physiological role of the lysEG system is to prevent bacteriostasis due to elevated L-lysine or L-arginine concentrations that arise during growth in the presence of peptides or in mutants possessing a deregulated biosynthesis pathway. C. glutamicum has additional export activities other than those of LysE for exporting L-histidine, L-citrulline and L-ornithine.

Two types of auditory neglect.

Auditory neglect, defined as inattention to stimuli within the left hemispace, is mostly reported in association with left ear extinction in dichotic listening. However, it remains disputed as to how far dichotic extinction reflects a primary attentional deficit and is thus appropriate for the diagnosis of auditory neglect. We report here on four patients who presented left ear extinction in dichotic listening following right unilateral hemispheric lesions. Auditory spatial attention was assessed with two additional tasks: (i) diotic test by means of interaural time differences (ITDs), simulating bilateral simultaneous spatial presentation of the dichotic tasks without the inconvenience of interaural intensity or content difference; and (ii) sound localization. A hemispatial asymmetry on the ITD diotic test or a spatial bias on sound localization were found to be part of auditory neglect. Two patients (J.C.N. and M.B.) presented a marked hemispatial asymmetry favouring the ipsilesional hemispace in the ITD diotic test, but did not show any spatial bias in sound localization. Two other patients (A.J. and E.S.) had the reverse profile: no hemispatial asymmetry in the ITD diotic test, but a severe spatial bias directed to the ipsilesional side in sound localization. J.C.N. and M.B. had mainly subcortical lesions affecting the basal ganglia. A.J. and E.S. had cortical lesions in the prefrontal, superior temporal and inferior parietal areas. Thus, there are two behaviourally and anatomically distinct types of auditory neglect characterized by: (i) deficit in allocation of auditory spatial attention following lesions centred on basal ganglia; or (ii) distortion of auditory spatial representation following frontotemporoparietal lesions.

Consistency of species ranking based on functional leaf traits.

• Specific leaf area (leaf area to dry mass ratio), leaf dry matter content (leaf dry mass to saturated fresh mass ratio) and leaf nitrogen concentration (LNC) have been proposed as indicators of plant resource use in data bases of plant functional traits. • We tested whether species ranking based on these traits was repeatable by studying spatio-temporal variations in specific leaf area and leaf dry matter content of water-saturated leaves (SLASAT and LDMCSAT ), as well as in LNC, for 57 herbaceous and woody species (or subsets thereof) growing under the Mediterranean climate of southern France. • Interseason and intersite variations were more pronounced than interannual variations, but species ranking for a given trait remained mostly consistent in space and time. Classifications based on LDMCSAT were generally more repeatable across years and sites, whereas those based on SLASAT were more stable over seasons. LNC usually gave the least repeatable classifications. • Species rankings were not completely similar for the three traits. Discussion of reproducibility, ease of trait measurement, as well as trait-function relationships led us to propose that measurements of the leaf traits, SLASAT and/or LDMCSAT , were the most suitable in large screening programmes.

Interhemispheric transfer of visual motion information after a posterior callosal lesion: a neuropsychological and fMRI study.

Interhemispheric transfer of visual information was investigated behaviourally and with functional magnetic resonance imaging (fMRI) 6 months after a lesion of the posterior two-thirds of the corpus callosum. On tachistoscopical left hemifield presentation, the patient was severely impaired in reading letters, words and geographical names and moderately impaired in naming pictures and colours. In contrast, interhemispheric transfer of visual motion information, tested by verbal report of the direction of short sequences of coherent dot motion presented within the left hemifield, was preserved. The pattern of cerebral activation elicited by apparent motion stimuli was studied with fMRI and compared to that of normal subjects. In normal subjects, apparent motion stimuli, as compared to darkness, activated strongly striate and extrastriate cortex. When presented to one hemifield only, the contralateral calcarine region was activated while regions on the occipital convexity, including putative area V5, were activated bilaterally. A similar activation pattern was found in the patient with a posterior callosal lesion; unilateral left or right hemifield stimulation was accompanied by activation in the contralateral and ipsilateral occipital convexity. Ipsilateral hemifield representation in the extrastriate visual cortex is believed to depend on callosal input. Our observation suggests that this is not the case for visual motion representation and that other, probably parallel, pathways may mediate visual motion transfer after posterior callosotomy.

Auditory agnosia and auditory spatial deficits following left hemispheric lesions: evidence for distinct processing pathways.

Auditory recognition and auditory spatial functions were studied in four patients with circumscribed left hemispheric lesions. Patient FD was severely deficient in recognition of environmental sounds but normal in auditory localisation and auditory motion perception. The lesion included the left superior, middle and inferior temporal gyri and lateral auditory areas (as identified in previous anatomical studies), but spared Heschl's gyrus, the acoustic radiation and the thalamus. Patient SD had the same profile as FD, with deficient recognition of environmental sounds but normal auditory localisation and motion perception. The lesion comprised the postero-inferior part of the frontal convexity and the anterior third of the temporal lobe; data from non-human primates indicate that the latter are interconnected with lateral auditory areas. Patient MA was deficient in recognition of environmental sounds, auditory localisation and auditory motion perception, confirming that auditory spatial functions can be disturbed by left unilateral damage; the lesion involved the supratemporal region as well as the temporal, postero-inferior frontal and antero-inferior parietal convexities. Patient CZ was severely deficient in auditory motion perception and partially deficient in auditory localisation, but normal in recognition of environmental sounds; the lesion involved large parts of the parieto-frontal convexity and the supratemporal region. We propose that auditory information is processed in the human auditory cortex along two distinct pathways, one lateral devoted to auditory recognition and one medial and posterior devoted to auditory spatial functions.

The LysE superfamily: topology of the lysine exporter LysE of Corynebacterium glutamicum, a paradyme for a novel superfamily of transmembrane solute translocators.

In Corynebacterium glutamicum the LysE carrier protein exhibits the unique function of exporting L-lysine. We here analyze the membrane topology of LysE, a protein of 236 amino acyl residues, using PhoA- and LacZ-fusions. The amino-terminal end of LysE is located in the cytoplasm whereas the carboxy-terminal end is found in the periplasm. Although 6 hydrophobic domains were identified based on hydropathy analyses, only five transmembrane spanning helices appear to be present. The additional hydrophobic segment may dip into the membrane or be surface localized. We show that LysE is a member of a family of proteins found, for example, in Escherichia coil, Bacillus subtilis, Mycobacterium tuberculosis and Helicobacter pylori. This family, which we have designated the LysE family, is distantly related to two additional protein families which we have designated the YahN and CadD families. These three families, the members of which exhibit similar sizes, hydropathy profiles, and sequence motifs comprise the LysE superfamily. Functionally characterized members of the LysE superfamily export L-lysine, cadmium and possibly quarternary amines. We suggest that LysE superfamily members will prove to catalyze export of a variety of biologically important solutes.

Distinct short-term memory systems for sound content and sound localization.

Short-term memory for sound content and sound localization was investigated in normal subjects using the same/different comparison of two sound stimuli separated by an interval. Auditory or visual interference tasks requiring recognition or spatial judgements were introduced in the interval. Auditory interference tasks reduced memory for sound content and sound location in a specific way. Memory for sound content was significantly more reduced by auditory recognition than by auditory spatial interference task. Visual interference tasks reduced significantly memory for sound location but not for sound content. These results suggest that (i) short-term memory for sound content and that for sound location involve partially distinct processing; and (ii) auditory spatial functions are more closely linked to visual functions than auditory recognition.

Non-verbal auditory recognition in normal subjects and brain-damaged patients: evidence for parallel processing.

Three different aptitudes involved in sound object recognition were tested in 60 normal subjects and 20 brain-damaged patients: (i) capacity to segregate sound objects on different cues (intensity steps, coherent temporal modulations or signal onset synchrony); (ii) asemantic recognition of sounds of real objects by judging whether two different sound samples belonged to the same object; and (iii) semantic identification of sounds of real objects as judged by means of a multiple choice response test. In 12 patients, different aptitudes involved in auditory recognition were disrupted separately and in a way which speaks in favour of parallel rather than hierarchical processing. There was no strong association between deficits in non-verbal auditory recognition and aphasia or the side of lesion.

Molecular mass and isoelectric properties of pituitary and urinary gonadotrophins in callitrichid primates.

In this study, the molecular masses and isoelectric characteristics of pituitary LH and FSH in two species of callitrichid primate, the common marmoset (Callithrix jacchus) and the cotton-top tamarin (Saguinus oedipus), were determined. Comparative data for urine samples from Callithrix jacchus are also presented. The separation of gonadotrophins from pituitary extracts and urine was performed under nonreducing conditions using SDS-PAGE and isoelectric focusing procedures. Hormone activity in gel eluates was determined by in vitro bioassays for LH and FSH and by a microtitre plate enzymeimmunoassay for LH. The molecular masses of pituitary and urinary proteins were between 36 and 37 kDa for LH and FSH, and were similar in both species. A dimer form of pituitary LH with a molecular mass of 33 kDa was also found in the cotton-top tamarin, but not in the marmoset. Guanidine-HCl dissociation of gonadotrophins from marmoset and tamarin pituitaries before electrophoresis gave proteins of 16 and 28 kDa, and 16 and 25 kDa range, respectively. Isoelectric focusing revealed numerous peaks of bioactivity for both LH and FSH, indicating the presence of multiple molecular variants (isoforms) of each hormone. In both species pituitary FSH eluted over a narrower and more acidic pH range than LH. Isoelectric focusing profiles for pituitary and urinary LH in the marmoset were similar (pH range 5.0-8.5), whereas urinary FSH demonstrated a more acidic profile than the pituitary protein. These results give comparative information on the properties of New World primate gonadotrophins, which should be useful in studies of their physiological action and in aiding the development of improved reagents and assays for their detection.

Differentiation of round cells in semen by means of monoclonal antibodies and relationship with male fertility.

OBJECTIVE: To differentiate round cells in semen samples of subfertile men and evaluate the clinical significance during infertility investigation. PATIENTS: One hundred and eight randomly chosen couples with a median duration of infertility of 4 (range, 1 to 20) years presenting at the outpatient infertility clinic of the University of Heidelberg, Germany. MAIN OUTCOME MEASURES: Differentiation of round cells in semen by means of monoclonal antibodies (mABs) and a streptavidin-biotin system for staining. Correlation of results with medical history, outcome of clinical examination, sperm analysis, microbial screening of both partners, evaluation of sperm functional capacity in vivo by means of the postcoital test (PCT) and in vitro with the standardized crossed sperm-cervical mucus penetration test (SCMPT) and the subsequent fertility in a prospective study. RESULTS: The method used for differentiation of round cells proved to be practical and suitable for routine use. The percentage of leukocytes ranged from 0% to 58% with a median of 3%. Number of round cells and percentage of leukocytes did not differ markedly with regard to andrologic history, clinical findings, for example, varicocele, results of standard sperm analysis, and microbial colonization of semen samples. However, high rates of leukocytes of the round cells correlated with reduced sperm count and morphology and results of PCT. Leukocyte-positive (> 15% leukocytes) specimens were also significantly more frequent in case of inadequate SCMPT and reduced sperm penetration ability in vitro. CONCLUSIONS: In asymptomatic patients (in terms of genital tract infection), the majority of round cells consist of immature germ cells and < 5% are white blood cells. The streptavidin-biotin system and the mABs used in this study proved to be useful to identify patients with elevated rates of leukocytes in semen possibly reflecting subclinical genital tract infection with influence on sperm functional capacity and subsequent fertility. Thus the procedure can be recommended to be included in a comprehensive evaluation of male fertility.

[Investigations on the incidence of Yersinia enterocolitica - infections in the various forms of appendicitis, cholelithiasis, and goitre (author's transl)]. / Untersuchungen über die Inzidenz der Infektionen mit Yersinia enterocolitica bei den verschiedenen Formen der Appendizitis, der Cholelithiasis und Patienten mit euthyroten und hyperthyroten Strumen.

Out of a total of 3347 patients operated on for acute appendicitis 125 were found to be infected with Yersinia enterocolitica. Histological examination revealed a catarrhal-purulent inflammation or a phlegmonous-gangrenous inflammation in 58,6%. This detection of Yersinia enterocolitica does not justify the omission to perform appendectomy, because true appendicitis cannot be ruled out.