Concentrations of progesterone and a PGF2α metabolite during the interovulatory interval compared to the corresponding days of pregnancy in mares

The concentrations of progesterone (P4) and a metabolite of PGF2α (PGFM) in mares were compared between the interovulatory interval (IOI; n = 8) and the corresponding days of pregnancy (n = 9). In daily blood samples, P4 increased between the day of ovulation (Day 0) and ∼Day 6 and then gradually decreased until the beginning of luteolysis in the IOI group. Before the beginning of luteolysis, there were no significant differences in P4 concentrations between the IOI and early pregnancy. In the IOI, PGFM concentration on the day before the beginning of luteolysis began to increase (P < 0.04) and reached a maximum mean (42.9 ± 11.6 pg/mL) on Day 14. In pregnancy, a novel increase in PGFM occurred from Day 12 to a maximum mean on Day 15 (16.7 ± 3.1 pg/mL). Daily PGFM concentrations were not different between the two groups until the increase just before luteolysis in the IOI. During 8-h sessions of hourly blood sampling, the mean and maximum PGFM concentrations were significantly greater in IOI than in pregnancy for each 8-h session on Days 13, 14, and 15. The minimum was not different between groups on any day. Pulses of PGFM were identified by coefficient of variation during the hourly 8-h sessions on day-sets of Days 4-7, 9-11, and 13-16. Despite the PGFM increase in daily samples between Days 12 and 15 of pregnancy, the amplitude and peaks of CV-identified pulses did not differ in the pregnant mares among the three day-sets. The pulses were similarly small for day-sets 4-7 and 9-11 in the IOI and for all day-sets in pregnancy (eg, amplitude on Days 13-16: 43.4 ± 15.6 pg/mL vs 5.4 ± 1.1 pg/mL for IOI vs pregnancy). Hypothesis 1 was not supported that daily PGFM concentrations in an IOI increase at the intersection between the end of the rapid P4 increase and the gradual P4 decrease. Hypothesis 2 was supported that pregnant mares have low amplitude PGFM pulses during the days of the high amplitude pulses at luteolysis in the IOI.

Unexpectedly Large Electron Correlation Measured in Auger Spectra of Ferromagnetic Iron Thin Films: Orbital-Selected Coulomb and Exchange Contributions

A set of electron-correlation energies as large as 10 eV have been measured for a magnetic 2 ML Fe film deposited on Ag(001). By exploiting the spin selectivity in angle-resolved Auger-photoelectron coincidence spectroscopy and the Cini-Sawatzky theory, the core-valence-valence Auger spectrum of a spin-polarized system have been resolved: correlation energies have been determined for each individual combination of the two holes created in the four subbands involved in the decay: majority and minority spin, as well as e_{g} and t_{2g}. The energy difference between final states with parallel and antiparallel spin of the two emitted electrons is ascribed to the spin-flip energy for the final ion state, thus disentangling the contributions of Coulomb and exchange interactions.

The LVV Auger line shape of sulfur on copper studied by Auger photoelectron coincidence spectroscopy

We have studied the line shapes of Cu(0 0 1)-p (2 × 2)S L2VV and L3VV Auger decay by means of Auger photoelectron coincidence spectroscopy. Measuring the LVV Auger spectrum in coincidence with S 2p1/2 and 2p3/2 photoelectrons respectively, we have been able to separate the two overlapping Auger spectra and determine their intrinsic line shapes. The two Auger transitions, though shifted in energy, display an identical line shape whose main features can be qualitatively understood considering a single particle approximation but are better described within a Cini-Sawatzky (CS) approach. Comparison between the experimental and the CS calculated spectra confirms that a substantial part of the Auger lines (∼20%) can be ascribed to decay events accompanied by the excitation of one additional electron-hole pair in the valence band. For the first time, the locality of the Auger process combined with the surface sensitivity of the APECS technique and its ability to separate overlapping structures are used to study Auger transitions taking place at the the surface states of a S/noble-metal interface.

Dynamic screening probed by core-resonant double photoemission from surfaces

The universal response of a sudden created core hole, predicted to occur on an attosecond (10(-18)  s) time scale, lacks an experimental demonstration. With a two-dimensional coincidence spectrometer, we demonstrate an extensive energy sharing between the Ag 4p photoelectron and the N2,3VV Auger electron exceeding 10 eV. This energy width provides access to the time scale of the emission process. This is the fingerprint of the dynamic fluctuation process 4p(-1)⇌4d(-2)4f. The shakeup induced interband transitions from the Ag(100) surface are also identified by comparing the coincidence spectrum with the M4,5VV Auger transitions.

Spin-dependent on-site electron correlations and localization in itinerant ferromagnets

Spin selectivity in angle-resolved Auger photoelectron coincidence spectroscopy (AR-APECS) is used to probe electron correlation in ferromagnetic thin films. In particular, exploiting the AR-APECS capability to discriminate Auger electron emission events characterized by valence hole pairs created either in the high or in the low total spin state, a strong correlation effect in the Fe M(2,3)VV Auger line shape (measured in coincidence with the Fe 3p photoelectrons) of Fe/Cu(001) thin films is detected and ascribed to interactions within the majority spin subband. Such an assignment follows from a close comparison of the experimental AR-APECS line shapes with the predictions of a model based on spin polarized density functional theory and the Cini-Sawatzky approach.

Insight on hole-hole interaction and magnetic order from dichroic auger-photoelectron coincidence spectra

The absence of sharp structures in the Auger line shapes of partially filled bands has severely limited the use of electron spectroscopy in magnetic crystals and other correlated materials. By a novel interplay of experimental and theoretical techniques we achieve a combined understanding of the photoelectron, Auger, and Auger-photoelectron coincidence spectra (APECS) of the antiferromagnetic CoO. A recently discovered dichroic effect in angle resolved (DEAR) APECS reveals a complex pattern in the Auger line shape, which is here explained in detail, labeling the final states by their total spin. Since the dichroic effect exists in the antiferromagnetic state but vanishes at the Néel temperature, the DEAR-APECS technique detects the phase transition from its local effects, thus providing a unique tool to observe and understand magnetic correlations where the usual methods are not applicable.

The attenuation length of low energy electrons in Yb

Photoelectron emission spectra in a photon energy range between 7.5 and 21 eV are measured for in situ grown polycrystalline Yb films. By comparing bulk and surface core level shifted 4f components we give an estimation of the effective attenuation length (EAL) for low energy (6-20 eV) electrons in Yb, establishing a moderate increase of the EAL upon electron energy decrease. The experimental EAL data are found to be a factor of four smaller than those predicted from the so-called 'universal curve'.

MicroRNAs in search of a target

As the number of known microRNAs (miRNAs) increases, and their importance in physiology and disease becomes apparent, the identification of their regulatory targets is a requisite for a full characterization of their biological functions. Computational methods based on sequence homology and phylogenetic conservation have spearheaded this effort in the last 3 years, but they may not be sufficient. Experimental studies are now needed to extend and validate the computational predictions and further our understanding of target recognition by miRNAs.

[Risks for construction workers: analysis of the upper limb posture]

Our work focuses on the analysis of risks associated with onset of cumulative trauma disorders (CTD) among construction workers, and the goal is to evaluate the different degree of involvement of articular segments of the upper limbs. A number of workers with different qualification were analyzed using the OCRA Index and check-list protocols, applied to highly or moderate repetitive activities. In order to evaluate the involvement of the various upper limbs segments, we have extracted the information contained in the "posture section" of the protocols, before they are grouped together in the final posture risk value, and analyzed them considering the observed working activities. We obtained an "involvement index" related to any of the upper limb segments, highlighting the information about local involvement during the various phases of work. This "involvement index" may help in analyzing and evaluating the ergonomic risk referring to each articular segment during activity, and can be useful in the analysis and prevention of work related CTDs.

Experimental observation of post-collision interaction and interference effects in resonant double photoionization processes

The combined effects of post-collision interaction in the final state and interference due to the indistinguishability of the two electrons have been studied in a selected case of resonant double photoionization of neon. In our coincidence experiments, the photo- and Auger-electron pair was measured when the two electrons have nearly equal energy and are ejected at small mutual angle. The obtained energy distributions exhibit a strong interplay of post-collision interaction and interference effects, in agreement with the theoretical prediction of Sheinerman and Schmidt [J. Phys. B 30, 1677 (1997)] made on beryllium.

A brain-enriched polypyrimidine tract-binding protein antagonizes the ability of Nova to regulate neuron-specific alternative splicing

The Nova paraneoplastic antigens are neuron-specific RNA binding proteins that participate in the control of alternative splicing. We have used the yeast two-hybrid system to isolate Nova interacting proteins and identify an RNA binding protein that is closely related to the polypyrimidine tract-binding protein (PTB). The expression of this protein, brPTB, is enriched in the brain, where it is expressed in glia and neurons. brPTB interacts with Nova proteins in cell lines and colocalizes with Nova within neuronal nuclei. We previously found that Nova binds to a pyrimidine-rich RNA element present upstream of an alternatively spliced exon, E3A, in glycine receptor alpha2 (GlyRalpha2) pre-mRNA, and this binding is implicated in Nova-dependent regulation of splicing. Cotransfection assays with a GlyRalpha2 minigene demonstrate that brPTB antagonizes the action of Nova to increase utilization of GlyRalpha2 E3A. brPTB binds to a 90-nt GlyRalpha2 RNA adjacent to the Nova binding site, but with an affinity that is more than 10-fold lower than Nova. When a putative binding site for brPTB on the GlyRalpha2 RNA is mutated, binding is abolished and the inhibitory effect on Nova-dependent exon selection disappears. These results suggest that brPTB is a tissue-restricted RNA binding protein that interacts with and inhibits the ability of Nova to activate exon selection in neurons.

Nova-1 regulates neuron-specific alternative splicing and is essential for neuronal viability

We have combined genetic and biochemical approaches to analyze the function of the RNA-binding protein Nova-1, the paraneoplastic opsoclonus-myoclonus ataxia (POMA) antigen. Nova-1 null mice die postnatally from a motor deficit associated with apoptotic death of spinal and brainstem neurons. Nova-1 null mice show specific splicing defects in two inhibitory receptor pre-mRNAs, glycine alpha2 exon 3A (GlyRalpha2 E3A) and GABA(A) exon gamma2L. Nova protein in brain extracts specifically bound to a previously identified GlyRalpha2 intronic (UCAUY)3 Nova target sequence, and Nova-1 acted directly on this element to increase E3A splicing in cotransfection assays. We conclude that Nova-1 binds RNA in a sequence-specific manner to regulate neuronal pre-mRNA alternative splicing; the defect in splicing in Nova-1 null mice provides a model for understanding the motor dysfunction in POMA.

Molecular evolution of the synapsin gene family

Synapsins, a family of synaptic vesicle proteins, play a crucial role in the regulation of neurotransmission and synaptogenesis. They have been identified in a variety of invertebrate and vertebrate species, including human, rat (Rattus norvegicus), cow (Bos taurus), longfin squid (Loligo pealei), and fruit fly (Drosophila melanogaster). Here, synapsins were cloned from three additional species: frog (Xenopus laevis), lamprey (Lampetra fluviatilis), and nematode (Caenorhabditis elegans). Synapsin protein sequences from all these species were then used to explore the molecular phylogeny of these important neuronal phosphoproteins. The ancestral condition of a single synapsin gene probably gave rise to the vertebrate synapsin gene family comprised of at least three synapsin genes (I, II, and III) in higher vertebrates. Synapsins possess multiple domains, which have evolved at different rates throughout evolution. In invertebrate synapsins, the most conserved domains are C and E. During the evolution of vertebrates, at least two gene duplication events are hypothesized to have given rise to the synapsin gene family. This was accompanied by the emergence of an additional conserved domain, termed A. J. Exp. Zool. ( Mol. Dev. Evol. ) 285:360-377, 1999.

The gas-phase photoemission beamline at Elettra

This paper reports the present stage of commissioning of the gas-phase photoemission beamline at Elettra, Trieste. The beamline is designed for atomic and molecular science experiments with high-resolution and high-flux synchrotron radiation. It consists of an undulator source, variable-angle spherical-grating monochromator and two experimental stations. The design value of the energy range is 20 to 800 eV with a specified resolving power of over 10000. The procedure adopted for calibration of this type of monochromator is discussed. At present a resolving power up to 20000 and a range up to 900 eV have been measured. Absorption spectra taken at the argon L(II,III)-edge and at the nitrogen, oxygen and neon K-edges are as sharp as, or sharper than, any reported in the literature. The instrumental broadening is well below the natural line-width making it difficult to quantify the resolution; this problem is discussed.

Kinetic analysis of the phosphorylation-dependent interactions of synapsin I with rat brain synaptic vesicles

1. Synapsin I, a major synaptic vesicle (SV)-associated phosphoprotein, is involved in the regulation of neurotransmitter release and synapse formation. By binding to both phospholipid and protein components of SV with high affinity and in a phosphorylation-dependent fashion, synapsin I is believed to cluster SV and to attach them to the actin-based cytoskeleton of the nerve terminal. 2. In the present study we have investigated the kinetic aspects of synapsin I-SV interactions and the mechanisms of their modulation by ionic strength and site-specific phosphorylation, using fluorescence resonance energy transfer between suitable fluorophores linked to synapsin I and to the membrane bilayer. 3. The binding of synapsin I to the phospholipid and protein components of SV has fast kinetics: mean time constants ranged between 1 and 4 s for association and 9 and 11's for ionic strength-induced dissociation at 20 degrees C. The interaction with the phospholipid component consists predominantly of a hydrophobic binding with the core of the membrane which may account for the membrane stabilizing effect of synapsin I. 4. Phosphorylation of synapsin I by either SV-associated or purified exogenous Ca2+/calmodulin-dependent protein kinase II (CaMPKII) inhibited the association rate and the binding to SV at steady state by acting on the ionic strength-sensitive component of the binding. When dephosphorylated synapsin I was previously bound to SV, exposure of SV to Ca2+/calmodulin in the presence of ATP triggered a prompt dissociation of synapsin I with a time constant similar to that of ionic strength-induced dissociation. 5. In conclusion, the reversible interactions between synapsin I and SV are highly regulated by site-specific phosphorylation and have kinetics of the same order of magnitude as the kinetics of SV recycling determined in mammalian neurons under comparable temperature conditions. These findings are consistent with the hypothesis that synapsin I associates with, and dissociates from, SV during the exo-endocytotic cycle. The on-vesicle phosphorylation of synapsin I by the SV-associated CaMPKII, and the subsequent dissociation of the protein from the vesicle membrane, though not involved in mediating exocytosis of primed vesicles evoked by a single stimulus, may represent a prompt and efficient mechanism for the modulation of neurotransmitter release and presynaptic plasticity.

[Neurocysticercosis: a rare cause of convulsive crises]

The cysticercosis is an infestation caused from the larva of Taenia solium, which is demoniated Cysticercus cellulosae. Infestation by the encysted forms occur within brain, muscle, cutis, eye and more rarely within kidney, liver, thyroid. The cysties cause inflammation, oedema and residual calcification. In the SNC they are responsible for seizures, usually of focal type, hydrocephalus, meningitis, endocranic hypertension, stroke. One case of neurocysticercosis in a 15 years old boy is described: the clinical pictures, the neuroradiologic images and the treatment are discussed.

LU52396, an inhibitor of the store-dependent (capacitative) Ca2+ influx

The effects of 1-[2-(4-fluorophenyl)cyclohexyl]-2-[4-(3-phenylalkyl)-piperazin -1-yl]- ethanol, LU52396, on a) Ca2+ influx across the plasma membrane and b) Ca2+ mobilization from intracellular rapidly-exchanging Ca2+ stores were investigated in HeLa cells and in isolated microsomal fractions derived from the cerebellum and the skeletal muscle. LU52396 was found to be a potent inhibitor (Ki of about 2 microM) of the Ca2+ influx activated by depletion of intracellular Ca2+ stores, a phenomenon referred to as store-dependent or capacitative Ca2+ influx. Such an effect, which was reversed by cell washing, was mediated neither by a depolarization of the cell, with decrease in the driving force for cation influx, nor by a change of the intracellular pH, and might therefore be due to a direct action of the drug on either the responsible channel in the plasma membrane or, less likely, on its regulatory mechanisms. Additional effects, i.e. inhibition of receptor-mediated Ca2+ influx, of Ca2+ release from intracellular stores via either inositol 1,4,5-trisphosphate or ryanodine receptors, and of Ca2+ reuptake into the stores via sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPases, were also induced by the drug, however at concentrations 20-fold or more than those effective on the store-dependent influx. To our knowledge LU52396 is the first pharmacological tool that is found to be addressed with some preference to the store-dependent Ca2+ influx. It promises, therefore, to be useful for the characterization of the process, the identification of the responsible channel and, possibly, also of the molecular mechanisms through which these channels operate.

[Magnesium in the prophylaxis of primary headache and other periodic disorders in children]

Migraine has been recently defined a "central neuronal hyperexcitability state", maybe magnesium-dependent, and magnesium has been occasionally employed in the therapy of adult migraine. The Authors, on the basis of their personal experience (previous electromyographic studies), consider childhood migraine and periodic syndrome as a clinical equivalent of spasmophilia, in which an intracellular deficit of magnesium has been demonstrated, and have employed a magnesium salt in the prophylaxis of childhood migraine and migraine equivalents. 40 children with periodic syndrome (17 M and 23 F, aged 10.4 +/- 2.9 years) have been treated with magnesium pidolate, with doses ranging from 1.5 g/die to 4.5 g/die (corresponding to 122-366 mg Mg++):25 of them presented migraine as the main symptom, 12 recurrent abdominal pain, 3 fever of unknown origin, along with many other periodic symptoms. The first control visits have been done at 1 month, clinical follow-up lasted a mean period of 6.1 months. Therapy was stopped at 1 month visit if ineffective (of some other drug was added); otherwise, magnesium therapy was continued with the same dosage for another month, then gradually reduced. Clinical response was considered good if crises ceased completely or their frequency was reduced to less than 33%; partial if reduced to less than 67% of previous incidence; absent if only slightly or not at all reduced. Clinical response was good in 72.5% of cases at 1 month, in 77.5% later; partial in 12.5% and 10%; absent in 15% and 12.5% respectively. No side effects were observed. The compliance of children and their families was complete.(ABSTRACT TRUNCATED AT 250 WORDS)

[Juvenile sudden death from spontaneous aortic rupture]

In the time interval 1979-1991, 150 cases of juvenile sudden death (< or = 35 years) were studied. Among these, 9 were due to aortic rupture within the pericardial cavity. Two were mycotic and 7 dissecting aneurysms. The latter, all male, age ranging from 17 to 31 years (mean 24), presented the following risk factors: Marfan syndrome in 2, isthmal coarctation associated with bicuspid aortic valve (BAV) in 3, isolated and normally functioning BAV in 2. Histology of the dissected aortic wall showed an equal severity of degenerative changes consisting of elastic fragmentation, cystic medial necrosis and medionecrosis. By reviewing our anatomical collection of dissecting aneurysm we found a 12% frequency of BAV. Taking into consideration that the frequency in normal population of BAV is near 1%, the association between bicuspid aortic valve and dissecting aneurysm should not be casual (p < 0.001).

IN CONCLUSION

a) natural history of BAV entails the risk of spontaneous aortic laceration and sudden death in the youth, either in the isolated form or in association with isthmal coarctation; b) the aortic tunica media in these conditions shows an intrinsic structural weakness very similar to that observed in Marfan syndrome, as to suggest a congenital, most probably genetic defect with phenotype expression not only at valve level, but also within the aortic wall; c) aortic dissection occurs nearly ten times more frequently in patients with BAV than in normal population.

[Fever as periodic disorder]

Slight, moderate but also high rises in temperature, excluding other causes of fever, can be considered symptoms of periodic syndrome originating by hypothalamic centers as soon as headache, recurrent abdominal pains, growing pains, dizziness, kinetosis. These rises aren't uncommon, but often aren't considered important and this few statistics are available. The Authors present 16 case reports of fever as periodic symptom and discuss how common factors exist in the mechanism of hyperthermia and other clinical signs of periodic syndrome (ex. migraine) but they are generally modulated differently so that disturbance of temperature regulation predominates in the first case, pain in the second.

[A diagnostic controversy: the significance of 14-6/sec positive spikes in clinical electroencephalography]

There has been a great dealt of discussion as to the clinical significance of E.E.G. 14-6 per second positive spikes (14-6 PS), a short burst lasting one second or less which occurs during light sleep in monopolar recordings, mainly in the posterior temporal regions and usually involving the parietal and occipital regions as well, for the most part in unsymmetrical fashion. Early interpretations stress the epileptic nature of vegetative attacks in patients with an inter-critical E.E.G. reading characterized by 14-6 P.S. Subsequently, however, this hypothesis has been refuted, mainly because E.E.G. intra-critical recordings have never shown evidence of any sort of paroxysmal activity. At present time expert think that the presence of 14-6 PS may be merely an indication of an electrical alteration associated with disorders in the neurovegetative area. In order to evaluate the possibility of using them as a diagnostic marker of migraine equivalents and periodic syndromes, we reviewed wake and sleep E.E.G. recordings, carried out consecutively and hence not selectively, in 617 children aged 5-16 years. 14-6 PS were present in 109 children (17.6%), 63 of whom showed evident symptoms of periodic syndrome (headache, recurrent abdominal pain, cyclic vomiting, kinetosis, etc.); hence 46 E.E.G. recording were false positive. 510 children were lacking in 14-6 PS, 91 of these presented symptoms of periodic syndromes (false negative). 14-6 PS are hence a marker 40.9% sensitive, 90.1% specific, with a predictable value of 57.7%. The search for 14-6 PS in children with periodic syndrome is not particularly sensitive as a test, but it is fairly specific: it may well constitute an useful element in diagnosis.

Localized ovarian cancer: surgery plus chemotherapy

Fifty-four patients were referred to Medical Oncology after operation for "limited" ovarian cancer; 7 were excluded because immediate restaging showed evidence of macroscopic spread to structures outside the true pelvis, and 10 will be considered separately because of microscopic spread shown only by cytology. Thirty-seven patients (31 stage I and 6 stage II) were accordingly accepted as "localized", because peritoneal cytology and diaphragm and omental plus parietal peritoneum histology could rule out the spread to the large abdominal cavity. Some of the referred patients had been operated in nearby hospitals; the Padua GYN Cin. performed 14 of the 37 first surgery operations and 30 of the 37 second look operations. All patients soon after surgery underwent first-line chemotherapy with 5 courses of high dose adriamycin plus cyclophosphamide for 4 months, then surgical second look, and second-line non-cross-resistant chemotherapy for 3 months. During the second look the organ and tissue removal was completed in those 21 patients having received "limited" first surgery. Two patients died within 5 years from admission, so that the overall 5 year actuarial survival from referral is 93% for the entire group with 11 patients still at risk; 87% are disease free 5 years after the second look with 7 at risk. Subdivision of the patients according to "adequate" vs. "limited" first surgery, may select a group (the "adequate" one, composed of 16 patients) completely free from relapses, up to now. The complex therapeutic program described seems to offer long term relapse-free survival to the majority of patients, while the few failures seem closely related with inadequacies of the initial surgical procedure.

[Thrombophlebitis of the cavernous sinus and inappropriate ADH secretion syndrome]

The septic thrombosis of the cavernous sinus is a rare and serious disease which still occurs occasionally. The physician should be aware of this fact when treating infections of the nasal orbital areas. A case is presented in whom the septic thrombosis of the cavernous sinus is associated with the syndrome of inappropriate secretion of antidiuretic hormone.