Bias in beliefs about the self is associated with depressive but not anxious mood.

BACKGROUND: Biases in beliefs about the self are associated with psychopathology and depressive and anxious mood, but it is not clear if both negative and positive beliefs are associated with depression or anxiety. We examined these relationships in people who present with a wide range of depressive and anxious mood across diagnostic categories. METHODS: We probed positive and negative beliefs about the self with a task in which 74 female participants with either affective disorder (depression and/or anxiety), borderline personality disorder or no psychiatric history indicated the degree to which 60 self-related words was "like them" or "not like them". Depressive and anxious mood were assessed with the Beck Depression Inventory-II and the Beck Anxiety Inventory. RESULTS: The participants with no psychiatric history (n=25) reported a positive bias in their beliefs about the self, the participants with affective disorder (n=23) reported no bias, and the participants with BPD (n=26) reported a negative bias. Two hierarchical multiple regressions demonstrated that the positive and negative beliefs contributed additively to the ratings of depression (corrected for anxiety), but did not contribute to the ratings of anxiety (corrected for depression). LIMITATIONS: Despite the apparent small sample size, the regression analyses indicated adequate sampling. Anxiety is a much more heterogeneous condition than is depression, so it may be difficult to find relevant self-descriptors. Only measures of endorsement were used. CONCLUSIONS: Biases in beliefs about the self are associated with depressed, but not anxious mood, across diagnostic categories.

Acidulated phosphate fluoride application changes the protein composition of human acquired enamel pellicle.

We evaluated, by proteomic analysis, whether the chemical changes provoked on enamel by acidulated phosphate fluoride (APF) application alter the protein composition of acquired enamel pellicle. Enamel slabs, pretreated with distilled water (negative control), phosphoric acid (active control) or APF solution, were immersed in human saliva for pellicle formation. The adsorbed proteins were extracted and analyzed by liquid chromatography-mass spectrometry/mass spectrometry. Fifty-six proteins were identified, 12 exclusive to APF and 11 to phosphoric acid. APF decreased the concentration of histatin-1, but increased the concentration of S100-A9, which is confirmed by immunoblotting. The findings suggest that APF application changes the acquired enamel pellicle composition.

Comparison of visual tracking algorithms on in vivo sequences for robot-assisted flexible endoscopic surgery.

Flexible endoscopes are used in many diagnostic and interventional procedures. Physiological motions may render the physician's task very difficult to perform. Assistance could be achieved by using motorized endoscopes and real-time visual tracking algorithm to automatically follow a selected target. In order to control the motors, one needs to have an accurate estimation of the motion of the target in the endoscopic view, which requires an efficient tracking algorithm. In this paper, we compare tracking algorithms on various in vivo targets in order to assess their behavior under different conditions. The study shows that among the difficulties which arise when tracking an in vivo target, the change of illumination is paramount. Nevertheless, some algorithms, with minor modifications and without a priori knowledge about the target, achieve very good results.

Clinical evaluation of two bilateral hand allotransplantations at six and three years follow-up.

We report a six and three years follow-up clinical evaluation of two bilateral hand allotransplantations from brain-dead multi-organs donors performed in two young adult traumatic hand amputees. Lifelong immunosuppressive treatment included tacrolimus, mycophenolate mofetil and prednisolone. In both patients, early complications were observed but were successfully treated. At follow-up, clinical results allow useful hand function in both patients, by far superior to what can be provided by current myoelectric prostheses. Although the long-term risks-benefits ratio of bilateral hand transplantation is still unknown, these two cases demonstrate that this new treatment is feasible. Further experimental and clinical research is needed to better delineate its role in the future of hand surgery.

Fast-neutron OSL sensitivity of thallium-doped ammonium salts.

The main problem in selecting suitable thermoluminescent (TL) materials for fast-neutron dosimetry is finding a material that is both tissue-equivalent and not damaged upon heating. Optically stimulated luminescence (OSL) avoids the need to heat the materials and allows the use of materials with a high content of hydrogen (responsible for 90% of the absorbed dose of fast-neutrons). The choice of studying the ammonium salts for their OSL properties was based on the calculation of their neutron kerma factor. A constant ratio of an ammonium salt's kerma coefficients to the tissue's kerma coefficients (in the fast-neutron range) is a prerequisite for a similar energy response to neutrons, i.e. tissue equivalency. The salts studied are NH4Br and (NH4)2SiF6 both doped with Tl+. This paper describes the OSL properties of Tl(+)-doped NH4Br and (NH4)2SiF6 after exposure to 14.5 MeV neutrons to explore their potential for developing new, tissue-equivalent OSL materials suitable for fast-neutron dosimetry. The relative neutron sensitivity, k, defined as the ratio of the sensitivity of the material to neutrons to its sensitivity to gamma rays, has been determined for 14.5 MeV neutrons and varies between k = 0.15 and k = 0.5. The latter value is a factor 2.5 higher than that found for known TL materials (k < or = 0.2). A drawback of these materials is the fast fading of the OSL signal.

A TL/OSL emission spectrometer extension of the Risø reader.

The integration of a low cost, compact sized spectrometer with the Risø reader is described. The luminescence light emitted by the sample is transmitted by an optical fibre onto a fixed entrance slit of a spectrograph. The light is measured with a high sensitivity 2048-element CCD-linear array detector (Avantes PC2000) sensitive in the UV-VIS region. The CCD array has a low readout noise and a photon sensitivity of 86 photons per count. Examples are given of both thermally and optically stimulated 3-D spectra showing the luminescence spectra as a function of temperature and time respectively. Spectra from CaF2:Tm (TLD-300) chips could be distinguished from the background (2 SD) at a 0.7 Gy dose level.

Optically and thermally stimulated luminescence of KMgF3:Ce3 and NaMgF3:Ce3+.

The potentialities of optically stimulated luminescence (OSL) for personal dosimetry of ionising radiation have stimulated the search for new synthetic materials with good dosimetric properties. The sensitivity of two new OSL materials KMgF3 and NaMgF3 doped with Ce3+ ions has been evaluated and found to be of the same order of magnitude as that of Al2O3:C. Several other characteristics have also been investigated. Promising results for KMgF3:Ce are the high sensitivity and the low fading. However, this material suffers from a high self-dose due to the presence of 40K. NaMgF5:Ce is sensitive as well but shows strong fading. Interesting information on the mechanism has been obtained by correlating the signals of OSL and TL. Furthermore, the different bleachabilities under blue LED illumination of the strongly overlapping glow peaks allowed the extraction of one single peak for KMgF3:Ce3+. The results demonstrate new possibilities offered by the combination of TL and OSL.

C. elegans EGL-9 and mammalian homologs define a family of dioxygenases that regulate HIF by prolyl hydroxylation.

HIF is a transcriptional complex that plays a central role in mammalian oxygen homeostasis. Recent studies have defined posttranslational modification by prolyl hydroxylation as a key regulatory event that targets HIF-alpha subunits for proteasomal destruction via the von Hippel-Lindau ubiquitylation complex. Here, we define a conserved HIF-VHL-prolyl hydroxylase pathway in C. elegans, and use a genetic approach to identify EGL-9 as a dioxygenase that regulates HIF by prolyl hydroxylation. In mammalian cells, we show that the HIF-prolyl hydroxylases are represented by a series of isoforms bearing a conserved 2-histidine-1-carboxylate iron coordination motif at the catalytic site. Direct modulation of recombinant enzyme activity by graded hypoxia, iron chelation, and cobaltous ions mirrors the characteristics of HIF induction in vivo, fulfilling requirements for these enzymes being oxygen sensors that regulate HIF.

Independent function of two destruction domains in hypoxia-inducible factor-alpha chains activated by prolyl hydroxylation.

Oxygen-dependent proteolytic destruction of hypoxia-inducible factor-alpha (HIF-alpha) subunits plays a central role in regulating transcriptional responses to hypoxia. Recent studies have defined a key function for the von Hippel-Lindau tumour suppressor E3 ubiquitin ligase (VHLE3) in this process, and have defined an interaction with HIF-1 alpha that is regulated by prolyl hydroxylation. Here we show that two independent regions within the HIF-alpha oxygen-dependent degradation domain (ODDD) are targeted for ubiquitylation by VHLE3 in a manner dependent upon prolyl hydroxylation. In a series of in vitro and in vivo assays, we demonstrate the independent and non-redundant operation of each site in regulation of the HIF system. Both sites contain a common core motif, but differ both in overall sequence and in the conditions under which they bind to the VHLE3 ligase complex. The definition of two independent destruction domains implicates a more complex system of pVHL-HIF-alpha interactions, but reinforces the role of prolyl hydroxylation as an oxygen-dependent destruction signal.

Hypoxia inducible factor-alpha binding and ubiquitylation by the von Hippel-Lindau tumor suppressor protein.

The von Hippel-Lindau tumor suppressor protein (pVHL) has emerged as a key factor in cellular responses to oxygen availability, being required for the oxygen-dependent proteolysis of alpha subunits of hypoxia inducible factor-1 (HIF). Mutations in VHL cause a hereditary cancer syndrome associated with dysregulated angiogenesis, and up-regulation of hypoxia inducible genes. Here we investigate the mechanisms underlying these processes and show that extracts from VHL-deficient renal carcinoma cells have a defect in HIF-alpha ubiquitylation activity which is complemented by exogenous pVHL. This defect was specific for HIF-alpha among a range of substrates tested. Furthermore, HIF-alpha subunits were the only pVHL-associated proteasomal substrates identified by comparison of metabolically labeled anti-pVHL immunoprecipitates from proteosomally inhibited cells and normal cells. Analysis of pVHL/HIF-alpha interactions defined short sequences of conserved residues within the internal transactivation domains of HIF-alpha molecules sufficient for recognition by pVHL. In contrast, while full-length pVHL and the p19 variant interact with HIF-alpha, the association was abrogated by further N-terminal and C-terminal truncations. The interaction was also disrupted by tumor-associated mutations in the beta-domain of pVHL and loss of interaction was associated with defective HIF-alpha ubiquitylation and regulation, defining a mechanism by which these mutations generate a constitutively hypoxic pattern of gene expression promoting angiogenesis. The findings indicate that pVHL regulates HIF-alpha proteolysis by acting as the recognition component of a ubiquitin ligase complex, and support a model in which its beta domain interacts with short recognition sequences in HIF-alpha subunits.

Inhibiting albumin glycation ameliorates diabetic nephropathy in the db/db mouse.

Albumin modified by Amadori glucose adducts stimulates the expression of extracellular matrix proteins by glomerular mesangial and endothelial cells, and has been mechanistically linked to the pathogenesis of diabetic nephropathy. To test the hypothesis that inhibiting the formation of glycated albumin might beneficially influence the development of kidney disease in diabetes, we treated diabetic db/db mice for 12 weeks with a low-molecular-weight compound (EXO-226) that impedes the condensation of free glucose with lysine epsilon-amino groups in albumin. Administration of EXO-226 (3 mg/kg) twice daily by gavage normalized the plasma concentration of glycated albumin within days after initiation of treatment and maintained glycated albumin within the normal range throughout the study, despite persistent and severe hyperglycemia. Urine albumin excretion, which was markedly increased at the start of the study (age 12 weeks), was significantly reduced in treated diabetic animals compared with their untreated diabetic littermates. The fall in creatinine clearance that was observed in untreated diabetic animals was prevented in diabetic littermates that received treatment. Compared with the nondiabetic controls, the amount of glomerular mesangial matrix was threefold greater in untreated diabetic mice; in contrast, the mesangial matrix fraction was only 1. 5 times that of nondiabetic controls in the treated diabetic animals, representing a reduction in mesangial matrix accumulation of more than 50%. EXO-226 also reduced the overexpression of mRNA encoding for alpha1 (IV) collagen in renal cortex of db/db mice. We conclude that normalization of plasma glycated albumin concentrations with the glycation inhibitor EXO-226 ameliorates the glomerular structural and functional abnormalities associated with diabetic nephropathy in the db/db mouse.

Synthesis and antibacterial properties of beta-diketone acrylate bioisosteres of pseudomonic acid A.

A series of beta-diketone acrylate bioisosteres 4 of pseudomonic acid A 1 have been synthesized and evaluated for their ability to inhibit bacterial isoleucyl-tRNA synthetase and act as antibacterial agents. A number of analogues have excellent antibacterial activity. Selected examples were shown to afford good blood levels and to be effective in a murine infection model.

The T-cell oncogenic protein HOX11 activates Aldh1 expression in NIH 3T3 cells but represses its expression in mouse spleen development.

Hox11 is a homeobox gene essential for spleen formation in mice, since atrophy of the anlage of a developing spleen occurs in early embryonic development in Hox11 null mice. HOX11 is also expressed in a subset of T-cell acute leukemias after specific chromosomal translocations. Since the protein has a homeodomain and can activate transcription, it probably exerts at least some of its effects in vivo by regulation of target genes. Representational difference analysis has been used to isolate cDNA clones corresponding to mRNA species activated following stable expression of HOX11 in NIH 3T3 cells. The gene encoding the retinoic acid-synthesizing enzyme aldehyde dehydrogenase 1 (Aldh1), initially called Hdg-1, was found to be ectopically activated by HOX11 in this system. Study of Aldh1 gene expression during spleen development showed that the presence of Aldh1 mRNA inversely correlated with Hox11. Hox11 null mouse embryos have elevated Aldh1 mRNA in spleen primordia prior to atrophy, while Aldh1 seems to be repressed by Hox11 during organogenesis of the spleens of wild-type mice. This result suggests that expression of Aldh1 protein is negatively regulated by Hox11 and that abnormal expression of Aldh1 in Hox11 null mice may cause loss of splenic precursor cells by aberrant retinoic acid metabolism.

Optimal activation of an endogenous gene by HOX11 requires the NH2-terminal 50 amino acids.

The HOX11 homeobox gene was first identified through studies of the t(7;10) and t(10;14) chromosomal translocations of acute T-cell leukemia. In addition, analysis of Hox11-/- mice has demonstrated a critical role for this gene in murine spleen development. A possible mode of in vivo function for the HOX11 protein in these two situations is regulation of target genes following DNA binding via the homeodomain, but little is known about how HOX11 regulates transcription in vivo. By performing transcriptional studies in yeast and mammalian one-hybrid systems, a modular transcriptional transactivation region at the NH2 terminus of HOX11 has been functionally dissected from other parts of the protein. This NH2-terminal region includes the previously identified short conserved Hep motif, which itself activates transcription in one-hybrid assays. The importance of the NH2-terminal region for the function of HOX11 in vivo was assayed by activating a HOX11-dependent gene in NIH 3T3 cells. Activation of this gene was found to be dependent upon an intact homeodomain in HOX11, but maximal activation was obtained only when the NH2-terminal 50 amino acids of HOX11 was present, showing that this region of HOX11 is important for in vivo transcriptional control of a chromosomal target gene.

A novel mechanism for isolated central hypothyroidism: inactivating mutations in the thyrotropin-releasing hormone receptor gene.

Isolated central hypothyroidism, characterized by insufficient TSH secretion resulting in low levels of thyroid hormones, is a rare disorder. We report a boy in whom isolated central hypothyroidism was diagnosed at 9 yr of age. Complete absence of TSH and PRL responses to TRH led us to speculate that he had an inactivating mutation of the TRH receptor gene. The patients' genomic DNA was isolated, and the entire coding region of the TRH receptor was amplified by the PCR and sequenced directly. Confirmation of the mutations and haplotyping of the family was performed using restriction enzymes. The biological activity of the wild-type and mutated TRH receptors was verified by evaluating the binding of labeled TRH and stimulation by TRH of total inositol phosphate accumulation in transfected HEK-293 and COS-1 cells. The patient was found to be a compound heterozygote, having inherited a different mutated allele from each of the parents; both mutations were in the 5'-part of the gene. Mutated receptors were unable to bind TRH and to activate total inositol phosphate accumulation. Our report is the first description of naturally occurring inactivating mutations of a G protein-coupled receptor linked to the phospholipase C second messenger pathway. The prevalence and phenotypic spectrum of TRH receptor mutations in isolated central hypothyroidism remain to be established.

The chemistry of pseudomonic acid. 17. Dual-action C-1 oxazole derivatives of pseudomonic acid having an extended spectrum of antibacterial activity.

A series of C-1 oxazole isosteres of pseudomonic acid A (mupirocin) bearing a nitroheterocycle have been synthesized, and significant differences in both spectrum of activity and potency were found between these derivatives and mupirocin. Additionally, the antibacterial potency of two members of this class of compounds against mupirocin-resistant staphylococci could not be accounted for solely by inhibition of the target enzyme isoleucyl-tRNA synthetase (IRS), indicating an additional mode of action. The most potent compound, the nitrofuran 3f (SB 205952), was the most electron affinic derivative prepared and was transformed by NAD(P)H-dependent bacterial reductases at a rate similar to that for nitrofurantoin. The second mode of action of this compound may therefore arise from its reduction to a species with cellular targets other than IRS. In in vivo studies, 3f was shown to be a very effective agent by both the subcutaneous and oral routes of administration.

Chemistry of pseudomonic acid. Part 16. Aryl and heteroaryl ketone derivatives of monic acid.

The synthesis, antibacterial activities, murine pharmacokinetic and infection model data for a range of aryl and heteroaryl ketone derivatives of monic acid (2a) are reported. The best results were found for the 3-furyl and 2-methoxy thiazol-5-yl analogues.

Relevance of Chlamydia pneumoniae murine pneumonitis model to evaluation of antimicrobial agents.

A mouse model of Chlamydia pneumoniae pneumonitis was established in outbred MF1 mice immunosuppressed with cyclophosphamide. Following intranasal inoculation with 2.2 x 10(3) inclusion-forming units of C. pneumoniae TW-183 per mouse, chlamydiae were culturable from the lungs for at least 29 days. Progressive subacute pneumonitis with perivascular and peribronchial lymphoid cell hyperplasia was observed, and C. pneumoniae organisms were located in consolidated areas of tissue by immunocytochemistry. Mice were treated orally, commencing at 8 days after infection, with clinically achievable concentrations of amoxicillin-clavulanate or ciprofloxacin (three times daily for 7 days), ofloxacin, doxycycline, or erythromycin (twice daily for 7 days), or azithromycin (once daily for 4 days). Despite disparate antichlamydial activity in cell culture and different pharmacokinetic properties in infected animals, all treatments reduced the chlamydial load in the lungs (P < 0.05) when the loads were evaluated by culture at 1 and 10 days after the cessation of dosing, and this was reflected in the histopathological and immunocytochemistry scores. There was no significant difference between these treatments, and C. pneumoniae TW-183 was eradicated from the majority but not from all mice. These results confirm the limited clinical data available to date. In conclusion, a range of oral antimicrobial agents commonly used for the treatment of community-acquired respiratory infection was found to be efficacious in this experimental model of C. pneumoniae pneumonitis, which may therefore be of utility in chemotherapy and follow-up studies.