Resonance signatures in the body-frame valence photoionization of CF4.

We present a combined experimental and theoretical investigation of the electron dynamics and body-frame angular dependence of valence photo-single ionization of CF4 and subsequent dissociation into CF3+ and F. Ionization from a valence t2 orbital shows overlapping shape resonances close to threshold that couple to the same total symmetry, leading to striking changes in the photoelectron angular distributions when viewed in the body-frame.

Effects of either tibolone or continuous combined transdermal estradiol with medroxyprogesterone acetate on coagulatory factors and lipoprotein(a) in menopause.

BACKGROUND/AIM: The aim of this prospective controlled study was to compare the effects of two therapies for menopause on factor VII (FVII) and hemostatic variables. METHODS: Postmenopausal women were assigned to receive one of the following treatments: transdermal estradiol (TTS E2; 50 microg) combined in a continuous sequential regimen with oral medroxyprogesterone acetate (MPA; 10 mg/day for 12 days) (group A; n = 20), tibolone (2.5 mg/day) (group B; n = 21) or placebo (group C; n = 19). Sixty women completed the 1-year treatment and underwent follow-up examinations after 3, 6 and 12 months. RESULTS: TTS E2/MPA induced various changes in procoagulatory factors. At 12 months, fibrinogen, activated FVII (FVIIa) and coagulative FVII (FVIIc) had increased by 10.7, 12.9 and 3.7%, respectively. Among the fibrinolytic factors, plasminogen and alpha2-antiplasmin increased by 11.3 and 7.2%, respectively. Lipoprotein(a) [Lp(a)] and antithrombin III (ATIII) did not show any significant variation. Tibolone induced some changes toward a more homogeneous antithrombotic profile. Fibrinogen, FVIIa and FVIIc decreased significantly by 7.5, 8.1 and 21.3%, respectively. Plasminogen increased (by 11.8%) and Lp(a) decreased (by 28.4%). ATIII was unchanged with tibolone therapy. CONCLUSION: Our results show that tibolone induces a significant reduction in FVIIc and Lp(a) and a greater enhancement of factors promoting fibrinolysis than the TTS E2/MPA regimen.

Improved flux limits for neutrinos with energies above 10(22) eV from observations with the Westerbork Synthesis Radio Telescope.

Particle cascades initiated by ultrahigh energy neutrinos in the lunar regolith will emit an electromagnetic pulse with a time duration of the order of nanoseconds through a process known as the Askaryan effect. It has been shown that in an observing window around 150 MHz there is a maximum chance for detecting this radiation with radio telescopes commonly used in astronomy. In 50 h of observation time with the Westerbork Synthesis Radio Telescope array we have set a new limit on the flux of neutrinos, summed over all flavors, with energies in excess of 4x10(22) eV.

Does cystic fibrosis neonatal screening detect atypical CF forms? Extended genetic characterization and 4-year clinical follow-up.

The neonatal screening protocol for cystic fibrosis (CF) is based on a first determination of blood immunoreactive trypsin (IRT1), followed by a first level genetic test that includes the 31 worldwide most common mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene (DNA31), and a second determination of blood immunoreactive trypsin (IRT2). This approach identifies, in addition to affected subjects, a high proportion of newborns with hypertrypsinaemia at birth, in whom only one mutation is identified and who have a negative or borderline sweat test and pancreatic sufficiency. Although it has been suggested that hypertrypsinaemia may be caused by a single CFTR mutation, whether such neonates should be merely considered as healthy carriers remains a matter of debate as hypertrypsinaemia at birth may be a biochemical marker of a CFTR malfunction because of a second mild mutation. We analyzed, by means of an extended sequencing protocol, 32 newborns who tested positive at an IRT1/DNA31/IRT2 screening protocol and in whom only one CFTR mutation was found. The results obtained demonstrate that 62.5% of these newborns were also carrying a second mild CFTR mutation. The high proportion of compound heterozygous subjects, combined with the results of a 4-year follow-up in nine of these subjects all of whom displaying initial CF clinical symptoms, suggest that it may be possible to use the IRT1/DNA31/IRT2 protocol of neonatal screening to identify newborns with atypical forms of CF. In view of these findings, an extended genetic search for subjects with compound heterozygosity and a periodic clinical assessment should be considered.

GRB 030329: 3 years of radio afterglow monitoring.

Radio observations of gamma-ray burst (GRB) afterglows are essential for our understanding of the physics of relativistic blast waves, as they enable us to follow the evolution of GRB explosions much longer than the afterglows in any other wave band. We have performed a 3-year monitoring campaign of GRB 030329 with the Westerbork Synthesis Radio Telescopes and the Giant Metrewave Radio Telescope. Our observations, combined with observations at other wavelengths, have allowed us to determine the GRB blast wave physical parameters, such as the total burst energy and the ambient medium density, as well as to investigate the jet nature of the relativistic outflow. Further, by modelling the late-time radio light curve of GRB 030329, we predict that the Low-Frequency Array (30-240 MHz) will be able to observe afterglows of similar GRBs, and constrain the physics of the blast wave during its non-relativistic phase.

Frequency of spinal arteriovenous malformations in patients with unexplained myelopathy.

The authors reviewed charts of 78 myelopathy patients who underwent spinal angiography for possible arteriovenous malformations (AVMs). Twenty-two patients had an AVM. No neurologic complications from angiography were observed. MRI findings of increased T2 signal or flow voids were strongly associated with AVMs. Spinal angiography should be performed in all patients with unexplained myelopathy after neurologic evaluation and an MRI demonstrating increased T2 signal or flow voids.

Natural killer cells and gamma/delta T cells in synovial fluid and in peripheral blood of patients with psoriatic arthritis.

OBJECTIVE: NK surface markers and gamma/delta TCR antigen are involved in non-MHC-restricted cytotoxicity, which represents a major effector mechanism of the cell-mediated immune response. We evaluated in PsA patients SF and PB lymphocytes expressing these cellular subsets in order to obtain information on the possible role played by them in the disease. METHODS: We studied 29 PsA and 27 RA patients, as well as 27 healthy controls. In 17 PsA and 16 RA patients with knee joint effusion, analysis of SF was performed. SF and PB lymphocyte analysis was performed by direct dual immunofluorescence flow cytomettry using anti-CD3, anti-CD4, anti-CD8, anti-CD19, anti-TCR-gamma/delta-1 and anti-CD16 and anti-CD56 monoclonal antibodies. RESULTS: PsA and RA patients had, with respect to controls, lower values (both as percentages and in absolute numbers) of PB T cells expressing gamma/delta TCR. SF Iymphocytes of PsA and RA patients were characterised, as compared to PB lymphocytes, by lower numbers (both in absolute numbers and in relative terms) of NK and NK-T cells. Considering the absolute numbers of the various lymphocyte subsets, a strong correlation was found in PsA SF between gamma/delta T cells and NK (p < 0.0007) or NK-T cells (p < 0.0003), as well as between NK and NK-T cells (p < 0.0019). There was instead no statistically significant correlation among the different SF or PB lymphocytes and the most relevant clinical or serological parameters. CONCLUSION: This study, analyzing the impairment of different subsets involved in non-MHC-restricted cytotoxicity, suggests that this component of the cell-mediated immune response seems to play a pivotal role in the development of PsA.

Enhanced optical emission during Crab giant radio pulses.

We detected a correlation between optical and giant radio pulse emission from the Crab pulsar. Optical pulses coincident with the giant radio pulses were on average 3% brighter than those coincident with normal radio pulses. Combined with the lack of any other pulse profile changes, this result indicates that both the giant radio pulses and the increased optical emission are linked to an increase in the electron-positron plasma density.

Comparison of two different protocols of neonatal screening for cystic fibrosis.

The results of two different protocols of neonatal cystic fibrosis (CF) screening in the Lazio region of Italy are reported. The first study, conducted from 1992 to 2000 on about 200,000 newborns, consisted of an immunoreactive trypsin (IRT) protocol without mutation analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, referred to as the IRT/IRT protocol. Approximately 5% of the newborns with a positive first IRT test were also positive at the second test; approximately 57% of the newborns with a high IRT level at the second test were subsequently found to be affected by CF. In September 1998, a second protocol that included mutation analysis (IRT/DNA/IRT protocol) was started. Comparison of the two different screening protocols in terms of sensitivity in detecting CF patients demonstrated that the IRT/DNA/IRT protocol is more effective because it is able to detect a higher number of CF patients than the IRT/IRT protocol. In the same period, in addition to the overall diagnosis performed on a screening basis, 64 other subjects were identified as being affected by CF on the basis of symptomatic findings. The overall incidence of CF (screening + symptoms) was 1 : 2982, while that for carriers was 1 : 27. The sensitivity of the screening program increased over the period from 1992 to 2000, with the enhanced sensitivity in the past 2 years being due to the introduction of the IRT/DNA/IRT protocol.

Simultaneous cycle sequencing assessment of (TG)m and Tn tract length in CFTR gene.

The lengths of the dinucleotide (TG)m and mononucleotide Tn repeats, both located at the intron 8/exon 9 splice acceptor site of the cystic fibrosis transmembrane conductance regulator (CFTR) gene whose mutations cause cysticfibrosis (CF), have been shown to influence the skipping of exon 9 in CFTR mRNA. This exon 9-skipped mRNA encodes a nonfunctional protein and is associated with various clinical manifestations in CF As a result of growing interest in these repeats, several assessment methods have been developed, most of which are, however, cumbersome, multi-step, and time consuming. Here, we describe a rapid methodfor the simultaneous assessment of the lengths of both (TG)m and Tn repeats, based on a nonradioactive cycle sequencing procedure that can be performed even without DNA extraction. This method determines the lengths of the (TG)m and Tn tracts of both alleles, which in our samples ranged from TG8 to TG12 in the presence of T5, T7, and T9 alleles, and also fully assesses the aplotypes. In addition, the repeats in the majority of these samples can be assessed by single-strand sequencing, with no need to sequence the other strand, thereby saving a considerable amount of time and effort.

Modulation of retinal cell populations and eye size in retinoic acid receptor knockout mice.

PURPOSE: The retinoic acid receptors are expressed from early stages of development in the diverse tissues that make up the vertebrate eye. Their loss has subtle effects on eye development. We adapted sensitive quantitative trait locus (QTL) mapping methods to assess consequences of inactivating alleles of the alpha and beta receptors, Rara and Rarb, on eye and retinal development. Rara is of particular interest because this gene is a candidate for Nnc1, a QTL that controls retinal ganglion cell proliferation. METHODS: We studied lines of mice in which expression of the a1 isoform of Rara or all isoforms of Rarb had been disrupted by gene targeting. We measured eye weight, lens weight, retinal area, and retinal ganglion cell number in each of six genotypes (Rara and Rarb -/-, +/-, +/+; 10-25 cases/genotype). RESULTS: Loss of either protein is associated with a small but significant loss of eye weight and retinal area. However, only the Rarb knockout has a significant effect on the ganglion cell population and the loss of both wildtype alleles leads to an 8,000 cell deficit. Surprisingly, loss of the Rara a1 isoform that is expressed in this cell population from early stages has no effect on number. Null alleles of both genes have little if any effect on lens growth. CONCLUSIONS: Despite its expression in embryonic retina, Rara is unlikely to be the Nnc1 QTL. In contrast, Rarb, a gene that maps to Chr 14 and which is not an Nnc1 candidate gene, has a significant effect on cell number and is therefore a QTL controlling this key population. This raises the intriguing possibility that normal allelic variants of Rarb modulate the ganglion cell population in other vertebrates, including humans.

Autoantibodies and endothelial dysfunction in well-controlled, uncomplicated insulin-dependent diabetes mellitus patients.

Patients with insulin-dependent diabetes mellitus (IDDM) are well known to be at high risk of vascular disease, and dysfunction of vascular endothelium is considered as an early step in the development of diabetic complications. Because of the involvement of autoimmunity in the pathogenesis of IDDM, our aim was to assess, in 45 IDDM patients without clinically evident vascular complications, whether early signs of endothelial cell dysfunction were correlated to alterations of the immune system. IDDM patients were characterized by significantly increased serum levels of C-reactive protein, of polymorphonuclear cells-derived elastase, of endothelin-1 (ET-1) and of thrombomodulin, while plasma concentrations of fibronectin (FNT) were significantly decreased, with a statistically significant inverse correlation between ET-1 and FNT values. The presence of circulating immune complexes (CIC) was investigated in 36 out of our 45 IDDM patients, and values above the cut-off were found in 17 (47.2%) of them. One-third of all patients showed values above the cut-off for IgG-aCL. In IDDM patients, at variance from the control group, the levels of ET-1 were directly correlated to those of von Willebrand factor, of anticardiolipin beta(2)-GPI and of CIC, with an inverse correlation with plasma FNT. An association between antiphospholipid antibodies and endothelial dysfunction and/or activation is therefore suggested, pointing to a synergism, in the early phases of IDDM vascular disease, between generation of autoantibodies and endothelial activation.

Inhibitory effect of somatostatin on neutral amino acid transport in isolated brain microvessels.

In the presence of somatostatin-14 or some of its receptorial agonists, the uptake of large neutral amino acids by isolated brain microvessels was found to be inhibited up to 50%, no other transport system being affected. Although the luminal and abluminal sides of brain endothelial cells are both capable of taking up large neutral amino acids, only uptake from the abluminal side appears to be inhibited by somatostatin. The involvement of a type-2 somatostatin receptor was suggested by assays with a series of receptor-specific somatostatin agonists, and was confirmed by the release of inhibition caused by a specific type-2 receptor antagonist. A type-2-specific mRNA was indeed shown to be present in both bovine brain microvessels ex vivo and primary cultures of endothelial cells from rat brain microvessels.

1H NMR-visible mobile lipid domains correlate with cytoplasmic lipid bodies in apoptotic T-lymphoblastoid cells.

The presence of nuclear magnetic resonance (NMR)-visible mobile lipid (ML) domains in apoptotic lymphoblasts suggests alterations in neutral lipid metabolism and compartmentation during programmed cell death. The detection of similar ML signals in activated lymphocytes raises questions about common mechanisms of ML formation during apoptosis and upon lymphoblast stimulation. Structure and subcellular localization of ML domains were therefore investigated by NMR, fluorescence and electron microscopy in Jurkat T-lymphoblasts either induced to apoptosis (by anthracyclines or dexamethasone or by serum deprivation) or activated by phorbol myristate acetate (PMA) plus ionomycin. ML contents in drug-treated cells correlated linearly with apoptosis, irrespective of the specific inducer and cell cycle arrest phase (r = 0.993, P < 0.001). Similar ML levels were measured in drug-induced apoptotic cells (A approximately 30-40%) and in non-apoptotic PMA/ionomycin-treated lymphoblasts (72 h). Lower ML contents were instead formed in serum-deprived apoptotic cells, with respect to controls. Increases in ML signals were associated, in either apoptotic or activated cells, with the accumulation of cytoplasmic, osmophilic lipid bodies (diameter < or = 1.0 microm), surrounded by own membrane, possessing intramembrane particles. The results support the hypothesis that ML are formed in the cytoplasm of drug-induced apoptotic cells during an early, 'biochemically active' phase of programmed cell death.

Erythroid differentiation and regulatory gene expression are modulated by adenosine derivatives interfering with S-adenosylmethionine metabolic pathway.

The differentiation of murine erythroleukemia cells and the expression of SCL, Id1 and c-myc regulatory genes were studied. The first gene is a positive regulator of differentiation, while the other two are both negative regulators of differentiation and positive regulators of proliferation. Accordingly, our data show that when differentiation is stimulated SCL is upregulated while Id1 and c-myc are, coordinately, downregulated. The cultures were treated with two adenosine derivatives, 3-deazaadenosine and 3-deazaaristeromycin, known to act on the metabolic pathway of the methyl donor S-adenosylmethionin, in order to assess the possibility of a coordinated modulation, by these drugs, of regulatory gene expression and erythroid cell differentiation. 3-Deazaaristeromycin caused the simultaneous downregulation of Id1 and c-myc, whereas 3-deazaadenosine caused their upregulation; both drugs produced a transient increase in SCL expression. The use of these drugs evidenced a predominant regulatory effect of negative regulators in the control of erythroid differentiation. The distinct effects of the two drugs on regulatory gene expression led to an increased differentiation induced by 3-deazaaristeromycin and to a reduced differentiation induced by 3-deazaadenosine, if compared with controls. Southern analysis of DNA digested with methylation-specific restriction endonucleases showed that the administration of 3-deazaaristeromycin resulted in hypomethylation of SCL and c-myc, thus evidencing, in these cells, a clear correlation between DNA hypomethylation and differentiation but no straightforward correlation between DNA methylation and gene expression.

The dynamics of myogenin site-specific demethylation is strongly correlated with its expression and with muscle differentiation.

The molecular mechanisms underlying the activation of tissue-specific genes have not yet been fully clarified. We analyzed the methylation status of specific CCGG sites in the 5'-flanking region and exon 1 of myogenin gene, a very important myogenic differentiation factor. We demonstrated a loss of methylation, at the onset of C2C12 muscle cell line differentiation, limited to the CCGG site of myogenin 5'-flanking region, which was strongly correlated with the transcriptional activation of this gene and with myogenic differentiation. The same CCGG site was also found to be hypomethylated, in vivo, in embryonic mouse muscle (a myogenin-expressing tissue), as opposed to nonmuscle (nonexpressing) tissues that had a fully methylated site. In a C2C12-derived clone with enhanced myogenic ability, demethylation occurred within 2 h of induction of differentiation, suggesting the involvement of some active demethylation mechanism(s) that occur in the absence of DNA replication. Exposure to drugs that inhibit DNA methylation by acting on the S-adenosylmethionine metabolism produced a further reduction, to a few minutes, in the duration of the demethylation dynamics. These effects suggest that the final site-specific DNA methylation pattern of tissue-specific genes is defined through a continuous, relatively fast interplay between active DNA demethylation and re-methylation mechanisms.

Regional differences in signalling transduction pathways among smooth muscle cells from rabbit colon.

Smooth muscle cells (SMC) from the circular muscle layer of rabbit colon, taken from the proximal and distal regions that are known to have different physiological and motor activities, were used to highlight distinct regional intrinsic myogenic properties and to investigate the correlations between receptor and signalling transduction pathways. Contractile agonists were shown to be more potent on proximal than on distal SMC in inducing contraction and intracellular Ca(2+) increase. Concentration-response curves of agonists-induced Ca(2+) increase were constantly shifted to the right, though remaining parallel, with respect to contraction curves, independently of the region analysed. Using agents activating different steps of cAMP-or cGMP-mediated intracellular cascades, main regional differences were revealed as far as relaxation was concerned. Relaxation of proximal SMC was found to be essentially cGMP mediated, while that of distal SMC was cAMP mediated. In conclusion, the motor patterns of the two regions appear to be influenced by distinct regional biochemical characteristics that are intrinsic to colonic SMC.

African-American fathers: perceptions of two generations.

The purpose of this study was to determine how African-American fathers of 10-14-years-olds viewed their assets and limitations as parents, and to find out how children from this age group saw the parent performance of their fathers. The Parent Success Indicator was administered to 102 fathers and to 104 adolescents. Significant differences were found between generations on five of six subscales. The independent variables entering the greatest effect on how both generations perceived parental success were amount of time father and child spent together, having an adult at home when a child returns from school, and gender of child.

In vitro induction of H1-H1 histone cross-linking by adenosine diphosphate-ribose polymers.

It is well-known that H1-H1 interactions are very important for the induction of 30 nm chromatin fiber and that, among all posttranslational modifications, poly(ADP-ribosyl)ation is one of those capable of modifying chromatin structure, mainly through H1 histone. As this protein can undergo both covalent and noncovalent modifications by poly(ADP-ribosyl)ation, our aim was to investigate whether and how ADP-ribose polymers, by themselves, are able to affect the formation of H1-H1 oligomers, which are normally present in a condensed chromatin structure. The results obtained in our in vitro experimental system indicate that ADP-ribose polymers are involved in chromatin decondensation. This conclusion was reached as the result of two different observations: (a) H1 histone molecules can be hosted in clusters on ADP-ribose polymers, as shown by their ability to be chemically cross-linked, and (b) H1 histone has a higher affinity for ADP-ribose polymers than for DNA; ADP-ribose polymers compete, in fact, with DNA for H1 histone binding.