High Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy: An Analytical Method for Selenium Speciation.

Selenium is in many ways an enigmatic element. It is essential for health but toxic in excess, with the difference between the two doses being narrower than for any other element. Environmentally, selenium is of concern due to its toxicity. As the rarest of the essential elements, its low levels often provide challenges to the analytical chemist. X-ray absorption spectroscopy (XAS) provides a powerful tool for in situ chemical speciation but is severely limited by poor spectroscopic resolution arising from core-hole lifetime broadening. Here we explore selenium Kα1 high energy resolution fluorescence detected XAS (HERFD-XAS) as a novel approach for chemical speciation of selenium, in comparison with conventional Se K-edge XAS. We present spectra of a range of selenium species relevant to environmental and life science studies, including spectra of seleno-amino acids, which show strong similarities with S K-edge XAS of their sulfur congeners. We discuss strengths and limitations of HERFD-XAS, showing improvements in both speciation performance and low concentration detection. We also develop a simple method to correct fluorescence self-absorption artifacts, which is generally applicable to any HERFD-XAS experiment.

Ajothiolanes: 3,4-Dimethylthiolane Natural Products from Garlic ( Allium sativum).

Stereoisomers of 5-(2-allylsulfinyl)-3,4-dimethylthiolane-2-ol, a family of 3,4-dimethylthiolanes of formula C9H16O2S2 we name ajothiolanes, were isolated from garlic ( Allium sativum) macerates and characterized by a variety of analytical and spectroscopic techniques, including ultraperformance liquid chromatography (UPLC), direct analysis in real time-mass spectrometry (DART-MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Ajothiolanes were found to be spectroscopically identical to a family of previously described compounds named garlicnins B1-4 (C9H16O2S2), whose structures we demonstrate have been misassigned. 2D 13C-13C NMR incredible natural abundance double quantum transfer experiments (INADEQUATE) were used to disprove the claim of nine contiguous carbons in these compounds, while X-ray absorption spectroscopy (XAS) along with computational modeling was used to disprove the claim that these compounds were thiolanesulfenic acids. On the basis of the similarity of their NMR spectra to those of the ajothiolanes, we propose that the structures of previously described, biologically active onionins A1-3 (C9H16O2S2), from extracts of onion ( Allium cepa) and Allium fistulosum, and garlicnin A (C12H20O2S4), from garlic extracts, should also be reassigned, in each case as isomeric mixtures of 5-substituted-3,4-dimethylthiolane-2-ols. We conclude that 3,4-dimethylthiolanes may be a common motif in Allium chemistry. Finally, we show that another garlic extract component, garlicnin D (C7H12O2S3), claimed to have an unprecedented structure, is in fact a known compound from garlic with a structure different from that proposed, namely, 2( E)-3-(methylsulfinyl)-2-propenyl 2-propenyl disulfide.

Evaluation of trainees' ability to perform obstetrical ultrasound using simulation: challenges and opportunities.

BACKGROUND: Evaluation of trainee's ability in obstetrical ultrasound is a time-consuming process, which requires involving patients as volunteers. With the use of obstetrical ultrasound simulators, virtual reality could help in assessing competency and evaluating trainees in this field. OBJECTIVE: The objective of the study was to test the validity of an obstetrical ultrasound simulator as a tool for evaluating trainees following structured training by comparing scores obtained on obstetrical ultrasound simulator with those obtained on volunteers and by assessing correlations between scores of images and of dexterity given by 2 blinded examiners. STUDY DESIGN: Trainees, taking the 2013 French national examination for the practice of obstetrical ultrasound were asked to obtain standardized ultrasound planes both on volunteer pregnant women and on an obstetrical ultrasound simulator. These planes included measurements of biparietal diameter, abdominal circumference, and femur length as well as reference planes for cardiac 4-chamber and outflow tracts, kidneys, stomach/diaphragm, spine, and face. Images were stored and evaluated subsequently by 2 national examiners who scored each picture according to previously established quality criteria. Dexterity was also evaluated and subjectively scored between 0 and 10. The Raghunathan's modification of Pearson, Filon's z, Spearman's rank correlation, and analysis of variance tests were used to assess correlations between the scores by the 2 examiners and scores of dexterity and also to compare the final scores between the 2 different methods. RESULTS: We evaluated 29 trainees. The mean dexterity scores in simulation (6.5 ± 2.0) and real examination (5.9 ± 2.3) were comparable (P = .31). Scores with an obstetrical ultrasound simulator were significantly higher than those obtained on volunteers (P = .027). Nevertheless, there was a good correlation between the scores of the 2 examiners judging on simulation (R = 0.888) and on volunteers (R = 0.873) (P = .81). CONCLUSION: An obstetrical ultrasound simulator is as good a method as volunteer-based examination for evaluating practical skills in trainees following structured training in obstetrical ultrasound. The threshold for success/failure should, however, be adapted as candidates obtain higher scores on the simulator. Advantages of the obstetrical ultrasound simulator include the absence of location and time constraints without the need to involve volunteers or to interfere with the running of ultrasound clinics. However, an obstetrical ultrasound simulator still lacks the ability to evaluate the trainees' ability to interact with patients.

Improved survival after one course of perioperative chemotherapy in early breast cancer patients. long-term results from the European Organization for Research and Treatment of Cancer (EORTC) Trial 10854.

The aim of this study was to examine whether one course of perioperative polychemotherapy yields better results in terms of survival, progression-free survival (PFS) and locoregional control than surgery alone in early stage breast cancer. From 1986 to 1991, 2795 patients with stage I/II breast cancer were randomised to receive either one perioperative course of an anthracycline-containing chemotherapeutic regimen within 36 h after surgery or surgery alone. Patients were followed-up for overall survival, PFS and locoregional recurrence. The median follow-up period at time of the analysis was 11 years. PFS and locoregional control were significantly better (P=0.025 and P=0.004, respectively) in the perioperative chemotherapy arm. Node-negative patients seemed to benefit most from the perioperative FAC. Patients who received perioperative chemotherapy and locoregional therapy alone had significantly better overall survival rates than patients who received locoregional therapy alone (P=0.004). Patients who received additional systemic therapy did not seem to benefit from one course of perioperative chemotherapy (P=0.65). One course of perioperative polychemotherapy does improve PFS and locoregional control in early stage breast cancers. This effect is still present after 11 years of follow-up.

A key role for GAP-43 in the retinotectal topographic organization.

To have a proper spatial visual perception, vertebrate retinal ganglion cells connect to their brain targets in a highly ordered fashion. The molecular bases for such topographic retinotectal connection in mammals still remain largely unknown. Using the gene knock-out approach in mice, we report here a key role for the GAP-43 growth cone protein in the development of the visual system. In mice bearing a targeted disruption of GAP-43 exon 1, a high proportion of retinal ganglion cell (RGC) axons was found to grow abnormally into the ipsilateral optic tract and into the hypothalamus. After leaving the optic chiasm during development, the GAP-43-deficient RGC axons generally follow the optic tracts but are unable to form proper terminal zones in the lateral geniculate nucleus. Moreover, in the superior colliculus, RGC axons lacking GAP-43 are intermingled. These results suggest an essential role for GAP-43 in development of the topographic retinotectal connection.

High-frequency stimulation of the globus pallidus internalis in Parkinson's disease: a study of seven cases.

The effectiveness of ventroposterolateral pallidotomy in the treatment of akinesia and rigidity is not a new discovery and agrees with recent investigations into the pathogenesis of Parkinson's disease, which highlight the role played by the unbridled activity of the subthalamic nucleus (STN) and the consequent overactivity of the globus pallidus internalis (GPi). Because high-frequency stimulation can reversibly incapacitate a nerve structure, we applied stimulation to the same target. Seven patients suffering from severe Parkinson's disease (Stages III-V on the Hoehn and Yahr scale) and, particularly, bradykinesia, rigidity, and levodopa-induced dyskinesias underwent unilateral electrode implantation in the posteroventral GPi. Follow-up evaluation using the regular Unified Parkinson's Disease Rating Scale has been conducted for 1 year in all seven patients, 2 years in five of them, and 3 years in one. In all cases high-frequency stimulation has alleviated akinesia and rigidity and has generally improved gait and speech disturbances. In some cases tremor was attenuated. In a similar manner, the authors observed a marked diminution in levodopa-induced dyskinesias. This could be an excellent primary therapy for younger patients exhibiting severe bradykinesia, rigidity, and levodopa-induced dyskinesias, which would allow therapists to keep ventroposterolateral pallidotomy in reserve as a second weapon.

Thromboembolic complications after perioperative chemotherapy in women with early breast cancer: a European Organization for Research and Treatment of Cancer Breast Cancer Cooperative Group study.

PURPOSE AND METHODS: Data from a randomized phase III trial in early breast cancer, comparing surgery followed by one short intensive course of perioperative fluorouracil, doxorubicin, and cyclophosphamide (FAC) versus surgery alone, were analyzed for the occurrence of thromboembolic complications within 6 weeks after surgery. RESULTS: Twenty-seven of 1,292 patients assigned to the perioperative chemotherapy treatment arm (2.1%) and 10 of 1,332 patients on observation (0.8%) developed thromboembolic events (P = .004). The frequency of thromboembolic complications was higher among postmenopausal women compared with premenopausal women (2.0% v 0.6%, P = .003). Patients who had mastectomy had a higher frequency of thromboembolic disease than those who had tumorectomy (2.3% v 0.7%, P < .001). Three deaths occurred after pulmonary embolism, all of them in the perioperative chemotherapy treatment arm. CONCLUSION: These results suggest a contributing role of perioperative chemotherapy to thromboembolic disease, especially in postmenopausal women and women undergoing mastectomy. Antithrombosis prophylaxis should be considered in the case of adjuvant perioperative chemotherapy.

Isolation of a zinc finger gene consistently deleted in DiGeorge syndrome.

DiGeorge syndrome is a human developmental disorder resulting in hypoplasia of the thymus and parathyroids, and conotruncal heart defects. We recently isolated four genes with zinc finger DNA binding motifs mapping to chromosome 22q11.2 DiGeorge critical region. We now report that one of them, ZNF74 gene, is hemizygously deleted in 23 out of 24 DiGeorge syndrome patients tested. ZNF74 mRNA transcripts are detected in human and mouse embryos but not in adult tissues. Sequence analysis of a corresponding cDNA reveals an an open reading frame encoding 12 zinc finger motifs of the Kruppel/TFIIIA type as well as N-terminal and C-terminal non-zinc finger domains. These results suggest that changes in the dosage of a putative transcription factor through ZNF74 hemizygous deletion may be critical for DiGeorge developmental anomalies.

Assessment of estrogenic recruitment before chemotherapy in advanced breast cancer: a double-blind randomized study. European Organization for Research and Treatment of Cancer Breast Cancer Cooperative Group.

PURPOSE: In the present phase III study, the specific effect of estrogenic recruitment was assessed by comparing two groups of patients with advanced breast cancer receiving either ethinylestradiol (EE2) or placebo (PL) before chemotherapy (CT). PATIENTS AND METHODS: The therapeutic regimen consisted of (1) estrogen suppression by aminoglutethimide (AGL) 1 g/d plus hydrocortisone (HC) 40 mg/d, with surgical castration performed on premenopausal patients; (2) fluorouracil (5-FU) 500 mg/m2, doxorubicin 50 mg/m2, and cyclophosphamide (CPA) 500 mg/m2 (FAC) intravenously (IV) every 3 weeks; (3) following randomization, patients were double-blinded to receive either PL or EE2 50 micrograms exactly 24 hours before receiving FAC. All patients had advanced breast cancer presumably sensitive to endocrine therapy (estrogen receptor-positive [ER+] and/or progesterone receptor-positive [PgR+] status) with measurable lesions; none had received prior systemic antineoplastic therapy for metastatic disease; prior adjuvant hormonal therapy (HT) or CT (without anthracyclines) was allowed if interval since completion was longer than 1 year. RESULTS: Among 154 patients treated according to the protocol, tolerance, response rates, time to progression, and median survival duration were identical in the PL and EE2 groups. Only performance status, dominant metastatic site, and menopausal status seemed to influence response (overall response, 64%), with the highest levels of partial remission (PR) and complete remission (CR) being achieved in premenopausal women (CR plus PR, 26% plus 55%) and in those with dominant soft tissue lesions (CR plus PR, 45% plus 28%). CONCLUSION: We conclude that the validity of the hormonal recruitment concept has not yet been established in clinical practice so that this approach remains experimental. The results achieved by combining (near) complete estrogenic suppression and cyclical FAC chemotherapy are not significantly different from those to be expected with the more conventional use of HT followed by CT in presumably hormone-responsive (ER+) patients.

GABA interneurons in the rat medial frontal cortex: characterization by quantitative in situ hybridization of the glutamic acid decarboxylase (GAD67) mRNA.

In situ hybridization of mRNA encoding one isoform of glutamic acid decarboxylase (GAD67) was performed in the rat medial frontal cortex (MFC) to characterize GABA interneurons. Qualitatively, the labelling obtained with a [35S]cDNA probe was in register with neurons and was never associated with glial cells. No obvious differences in the density of labelled cells were observed between the different areas of the MFC examined (infralimbic, prelimbic, anterior cingulate and precentral medial) and between the various cortical layers. Grain counting was performed on single cells in the various layers of the prelimbic and the anterior cingulate area, two main areas of the MFC. According to their grain density, neurons were arbitrarily classified as low, high and very high GAD67 mRNA content. The neurons with the high GAD67 mRNA content corresponded to around 50% of the labelled cells in all the layers and in both areas. In the prelimbic area, the neuronal population with a low GAD67 mRNA content varied from 50% in layers I and II-III to 40% in layers V-VI whereas the very high GAD67 mRNA content neurons corresponded to around 5% of the labelled neurons in all layers. In the anterior cingulate area the neuronal population showing low GAD67 mRNA content varied from 35% in layers I and II-III to 20% in layers V-VI. In this area, neurons with a very high GAD67 mRNA content were more numerous than in the prelimbic area: they varied from 15% in layers I and II-III to 30% in layers V-VI. Parallel to the presence of very highly labelled cells, GAD enzymatic activity measured both in the presence and in the absence of pyridoxal 5'-phosphate was higher in the anterior cingulate area than in the prelimbic area. The heterogeneity of GAD67 mRNA content at the cellular level might underlie the existence of subpopulations of GABA interneurons in the MFC and suggests a higher GABAergic inhibitory control in the anterior cingulate area than in the prelimbic area.

Expression of GAD mRNA in GABA interneurons of the rat medial frontal cortex.

The distribution of glutamic acid decarboxylase (GAD) mRNA containing cells was studied in the rat medial frontal cortex (MFC). The neurons labelled by the 35S-labelled cDNA probe were distributed uniformly throughout all the layers and represented 16% of the total neuronal population. It was possible to distinguish two cell populations expressing high and low levels of GAD mRNA corresponding to 63% and 27% of labelled cells, respectively. Concerning the laminar distribution of these two populations of GAD mRNA containing neurons, no marked difference was observed between the various areas of the MFC.

Polyadenylic-polyuridylic acid plus locoregional and pelvic radiotherapy versus chemotherapy with CMF as adjuvants in operable breast cancer. A 6 1/2 year follow-up analysis of a randomized trial of the French Federation of Cancer Centers (F.F.C.C.).

In this study, patients with operable breast cancer T2 or T3, treated by mastectomy + axillary dissection and with invaded axillary nodes (N+), were randomized to receive either: 1) postoperative locoregional and pelvic radiotherapy (RX) and Poly(A).Poly(U) (AU), 60 mg IV once a week for 6 weeks, or 2) CMF (cyclophosphamide 100 mg/sqm P.O. on days 1-14, methotrexate 40 mg/sqm IV on day 1 and 8, fluorouracil 600 mg/sqm IV on day 1 and 8; monthly cycle, for 6 months. Between March 1982 and December 1985, 517 patients were enrolled, 257 of whom were treated by RX + AU and 260 with CMF. The main clinical, pathological and prognostic characteristics were equally distributed in the two groups. The present analysis was conducted after a mean follow-up of 69 months (S.D. = 13). There was no significant difference in overall survival (OS) between the two groups (test adjusted by center and menopausal status); the five-year OS rate was 74% in the RXAU group and 77% in the CMF group. Relapse-free survival (RFS) was significantly higher (p = 0.05) in the RXAU group compared to the MCF group; the five-year RFS rates were 57% and 46% in the two groups respectively. This short, well-tolerated combined RXAU treatment appears to be as efficient as CMF and might offer an alternative to chemo- or hormonotherapy, in case of contraindications to these treatments.

[Subacute familial thalamic atrophy. Memory disorders and complete insomnia]. / Atrophie thalamique subaiguë familiale. Troubles mnésiques et insomnie totale.

Thalamic atrophy is rarely primitive. Selective atrophy of the dorso-medial and anterior thalamic nuclei has been reported in a few families. The clinical course is subacute. Symptoms and signs include sleep disorders and intellectual deficit. We report a new family with this uncommon disease and discuss its etiology.

Neurons containing messenger RNA encoding glutamate decarboxylase in rat hypothalamus demonstrated by in situ hybridization, with special emphasis on cell groups in medial preoptic area, anterior hypothalamic area and dorsomedial hypothalamic nucleus.

Previous deafferentation studies have suggested that most hypothalamic GABAergic innervation originates from neurons within the hypothalamus. We have investigated the distribution of GABAergic cell groups in the rat hypothalamus by means of the in situ hybridization technique, using a cDNA probe for messenger RNA encoding glutamate decarboxylase. Several major GABAergic cell groups were demonstrated, including cells of the tuberomammillary nucleus, arcuate nucleus, suprachiasmatic nucleus, medial preoptic area, anterior hypothalamic area, the dorsomedial hypothalamic nucleus, perifornical area, and lateral hypothalamic area. The most prominent glutamate decarboxylase mRNA-containing cell groups were located in the medial preoptic area, anterior hypothalamic area and dorsomedial hypothalamic nucleus, and were composed of small- to medium-sized neurons. Compared to previously well-characterized GABAergic cell groups in the tuberomammillary nucleus, reticular thalamic nucleus, and non-pyramidal cells of cerebral cortex, the cells of these GABAergic groups demonstrated only weak cDNA labelling, indicating that they contain lower levels of glutamate decarboxylase mRNA. Several types of control experiments supported the specificity of this cDNA labelling, and the GABAergic nature of these cell populations was further supported by detection of glutamate decarboxylase and GABA immunoreactivity. Abundance of GABAergic cells in many hypothalamic nuclei indicates that GABA represents quantitatively the most important transmitter of hypothalamic neurons, and may be involved in neuroendocrine and autonomic regulatory functions.

A single human gene encoding multiple tyrosine hydroxylases with different predicted functional characteristics.

Catecholaminergic systems in discrete regions of the brain are thought to be important in affective psychoses, learning and memory, reinforcement and sleep-wake cycle regulation. Tyrosine hydroxylase (TH) is the first enzyme in the pathway of catecholamine synthesis. Its importance is reflected in the diversity of the mechanisms that have been described which control its activity; TH levels vary both during development and as a function of the activity of the nervous system. Recently, we deduced the complete amino-acid sequence of rat TH from a complementary DNA clone encoding a functional enzyme. Here we demonstrate that, in man, TH molecules are encoded by at least three distinct messenger RNAs. The expression of these mRNAs varies in different parts of the nervous system. The sequence differences observed are confined to the 5' termini of the messengers and involve alternative splicing events. This variation has clear functional consequences for each putative form of the enzyme and could represent a novel means of regulating catecholamine levels in normal and pathological neurons.