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1.
Inorg Chem ; 62(4): 1328-1340, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36651855

RESUMO

In this work, the Na3[Ln(ODA)3]·2NaClO4·6H2O (Ln = Ce-Yb; ODA = oxydiacetate) series was analyzed with the ab initio ligand field theory (AILFT) module of the ORCA computational suite. The results were discussed within the framework of the angular overlap model (AOM) and compared to literature data. We find that the structural changes observed across the series exemplifies the effects of the lanthanide contraction also manifesting in the value of the AOM parameters. It is also shown that the complete active space self-consistent field (CASSCF) methodology is sufficient to describe the ligand field interactions in mononuclear lanthanide complexes, and the effects of dynamic correlation, through n-electron valence state perturbation theory (NEVPT2), are discussed. The calculated ligand field parameters of the present work are compared to the experimentally derived values from the literature.

2.
PLoS Med ; 19(4): e1003960, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35439243

RESUMO

BACKGROUND: Severe mental illness (SMI; schizophrenia, bipolar disorders (BDs), and other nonorganic psychoses) is associated with increased risk of cardiovascular disease (CVD) and CVD-related mortality. To date, no systematic review has investigated changes in population level CVD-related mortality over calendar time. It is unclear if this relationship has changed over time in higher-income countries with changing treatments. METHODS AND FINDINGS: To address this gap, a systematic review was conducted, to assess the association between SMI and CVD including temporal change. Seven databases were searched (last: November 30, 2021) for cohort or case-control studies lasting ≥1 year, comparing frequency of CVD mortality or incidence in high-income countries between people with versus without SMI. No language restrictions were applied. Random effects meta-analyses were conducted to compute pooled hazard ratios (HRs) and rate ratios, pooled standardised mortality ratios (SMRs), pooled odds ratios (ORs), and pooled risk ratios (RRs) of CVD in those with versus without SMI. Temporal trends were explored by decade. Subgroup analyses by age, sex, setting, world region, and study quality (Newcastle-Ottawa scale (NOS) score) were conducted. The narrative synthesis included 108 studies, and the quantitative synthesis 59 mortality studies (with (≥1,841,356 cases and 29,321,409 controls) and 28 incidence studies (≥401,909 cases and 14,372,146 controls). The risk of CVD-related mortality for people with SMI was higher than controls across most comparisons, except for total CVD-related mortality for BD and cerebrovascular accident (CVA) for mixed SMI. Estimated risks were larger for schizophrenia than BD. Pooled results ranged from SMR = 1.55 (95% confidence interval (CI): 1.33 to 1.81, p < 0.001), for CVA in people with BD to HR/rate ratio = 2.40 (95% CI: 2.25 to 2.55, p < 0.001) for CVA in schizophrenia. For schizophrenia and BD, SMRs and pooled HRs/rate ratios for CHD and CVD mortality were larger in studies with outcomes occurring during the 1990s and 2000s than earlier decades (1980s: SMR = 1.14, 95% CI: 0.57 to 2.30, p = 0.71; 2000s: SMR = 2.59, 95% CI: 1.93 to 3.47, p < 0.001 for schizophrenia and CHD) and in studies including people with younger age. The incidence of CVA, CVD events, and heart failure in SMI was higher than controls. Estimated risks for schizophrenia ranged from HR/rate ratio 1.25 (95% CI: 1.04 to 1.51, p = 0.016) for total CVD events to rate ratio 3.82 (95% CI: 3.1 to 4.71, p < 0.001) for heart failure. Incidence of CHD was higher in BD versus controls. However, for schizophrenia, CHD was elevated in higher-quality studies only. The HR/rate ratios for CVA and CHD were larger in studies with outcomes occurring after the 1990s. Study limitations include the high risk of bias of some studies as they drew a comparison cohort from general population rates and the fact that it was difficult to exclude studies that had overlapping populations, although attempts were made to minimise this. CONCLUSIONS: In this study, we found that SMI was associated with an approximate doubling in the rate ratio of CVD-related mortality, particularly since the 1990s, and in younger groups. SMI was also associated with increased incidence of CVA and CHD relative to control participants since the 1990s. More research is needed to clarify the association between SMI and CHD and ways to mitigate this risk.


Assuntos
Doenças Cardiovasculares , Insuficiência Cardíaca , Transtornos Mentais , Transtornos Psicóticos , Esquizofrenia , Doenças Cardiovasculares/epidemiologia , Humanos , Transtornos Mentais/complicações , Transtornos Mentais/epidemiologia , Esquizofrenia/complicações , Esquizofrenia/epidemiologia
3.
J Comput Chem ; 39(3): 176-186, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-29143342

RESUMO

The program BonnMag has been developed to calculate the absorption spectra and temperature dependent magnetic susceptibilities of f n systems. The computations of the transition energies are performed within the angular overlap model. Using Judd-Ofelt theory BonnMag allows estimation of the relative absorption coefficients of the electronic transitions with reasonable accuracy. A description of the theoretical background of the implemented methods is given. Using Slater-Condon-Shortley parameters and spin-orbit coupling coefficients for free Ln3+ ions from ab initio calculations, the transition energies of all Ln3+ ions are calculated and compared to the results from CASSCF/NEV-PT2 calculations. Splitting due to the ligand field as well as transition energies of all Cs2 NaLnCl6 (except Gd and Pm) are calculated using parameters reported in the literature. Based on the comparison between theory and experiment, the potential and limitations of the program BonnMag are shown. © 2017 Wiley Periodicals, Inc.

4.
Chemistry ; 24(20): 5319-5330, 2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29405448

RESUMO

The electronic and magnetic properties of a set of mononuclear terbium(III) and dysprosium(III) complexes with two tetradentate 1-hydroxy-pyridin-2-one (1,2-HOPO) ligands are reported. Two primary coordination geometries are observed, depending on the length of the linker between the 1,2-HOPO donor moieties and the resulting arrangements of the linker. Fine details of the magnetic circular dichroism (MCD) spectra of the dysprosium(III) complexes illustrate differences in the splitting of the J multiplets and allow for a thorough ligand field analysis. High frequency electron paramagnetic resonance (HF-EPR) studies of the terbium(III) complexes give insight into the composition of the ground states. Ab initio calculations are utilized to rationalize the experimental results and further illustrate the effect of the structural features on the electronic and magnetic properties of the different complexes.

5.
Chemistry ; 24(20): 5082-5085, 2018 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-29315883

RESUMO

Single crystal structural analysis of [FeII (tame)2 ]Cl2 ⋅MeOH (tame=1,1,1-tris(aminomethyl)ethane) as a function of temperature reveals a smooth crossover between a high temperature high-spin octahedral d6 state and a low temperature low-spin ground state without change of the symmetry of the crystal structure. The temperature at which the high and low spin states are present in equal proportions is T1/2 =140 K. Single crystal, variable-temperature optical spectroscopy of [FeII (tame)2 ]Cl2 ⋅MeOH is consistent with this change in electronic ground state. These experimental results confirm the spin activity predicted for [FeII (tame)2 ]2+ during its de novo artificial evolution design as a spin-crossover complex [Chem. Inf. MODEL: 2015, 55, 1844], offering the first experimental validation of a functional transition-metal complex predicted by such in silico molecular design methods. Additional quantum chemical calculations offer, together with the crystal structure analysis, insight into the role of spin-passive structural components. A thermodynamic analysis based on an Ising-like mean field model (Slichter-Drickammer approximation) provides estimates of the enthalpy, entropy and cooperativity of the crossover between the high and low spin states.

6.
Eur Biophys J ; 44(6): 393-415, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26129727

RESUMO

Magnetic circular dichroism (MCD) is a convenient technique for providing structural and mechanistic insight into enzymatic systems in solution. The focus of this review is on aspects of geometric and electronic structure that can be determined by MCD, and how this method can further our understanding of enzymatic mechanisms. Dinuclear Co(II) systems that catalyse hydrolytic reactions were selected to illustrate the approach. These systems all contain active sites with similar structures consisting of two Co(II) ions bridged by one or two carboxylates and a water or hydroxide. In most of these active sites one Co(II) is five-coordinate and one is six-coordinate, with differing binding affinities. It is shown how MCD can be used to determine which binding site--five or six-coordinate--has the greater affinity. Importantly, zero-field-splitting data and magnetic exchange coupling constants may be determined from the temperature and field dependence of MCD data. The relevance of these data to the function of the enzymatic systems is discussed.


Assuntos
Materiais Biomiméticos/química , Dicroísmo Circular , Cobalto/química , Hidrolases/química , Diester Fosfórico Hidrolases/química
7.
Inorg Chem ; 54(23): 11247-58, 2015 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-26588004

RESUMO

A series of seven isostructural homodinuclear lanthanide complexes are reported. The magnetic properties (ac and dc SQUID measurements) are discussed on the basis of the X-ray structural properties which show that the two lanthanide sites are structurally different. MCD spectroscopy of the dysprosium(III) and neodymium(III) complexes ([Dy(III)2(L)(OAc)4](+) and [Nd(III)2(L)(OAc)4](+)) allowed us to thoroughly analyze the ligand field, and high-frequency EPR spectroscopy of the gadolinium(III) species ([Gd(III)2(L)(OAc)4](+)) showed the importance of dipolar coupling in these systems. An extensive quantum-chemical analysis of the dysprosium(III) complex ([Dy(III)2(L)(OAc)4](+)), involving an ab initio (CASSCF) wave function, explicit spin-orbit coupling (RASSI-SO), and a ligand field analysis (Lines model and Stevens operators), is in full agreement with all experimental data (SQUID, HF-EPR, MCD) and specifically allowed us to accurately simulate the experimental χT versus T data, which therefore allowed us to establish a qualitative model for all relaxation pathways.

8.
Chemistry ; 20(43): 14102-11, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25204640

RESUMO

The first members of a promising new family of hybrid amino acid-polyoxometalates have emerged from a search for modular functional molecules. Incorporation of glycine (Gly) or norleucine (Nle) ligands into an yttrium-tungstoarsenate structural backbone, followed by crystallization with p-methylbenzylammonium (p-MeBzNH3(+)) cations, affords (p-MeBzNH3)6K2(GlyH)[As(III)4(Y(III)W(VI)3)W(VI)44Y(III)4O159(Gly)8(H2O)14]⋅47 H2O (1) and enantiomorphs (p-MeBzNH3)15(NleH)3[As(III)4(Mo(V)2Mo(VI)2)W(VI)44Y(III)4O160(Nle)9(H2O)11][As(III)4(Mo(VI)2W(VI)2)W(VI)44Y(III)4O160(Nle)9(H2O)11] (generically designated 2: L-Nle, 2 a; D-Nle, 2 b). An intensive structural, spectroscopic, electrochemical, magnetochemical and theoretical investigation has allowed the elucidation of site-selective metal substitution and photoreduction of the tetranuclear core of the hybrid polyanions. In the solid state, markedly different crystal packing is evident for the compounds, which indicates the role of noncovalent interactions involving the amino acid ligands. In solution, mass spectrometric and small-angle X-ray scattering studies confirm maintenance of the structure of the polyanions of 2, while circular dichroism demonstrates that the chirality is also maintained. The combination of all of these features in a single modular family emphasizes the potential of such hybrid polyoxometalates to provide nanoscale molecular materials with tunable properties.

9.
Inorg Chem ; 53(23): 12323-36, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25393875

RESUMO

Three synthetic analogues of westiallamide, H3L(wa), have previously been synthesized (H3L(1-3)) that have a common backbone (derived from l-valine) with H3L(wa) but differ in their heterocyclic rings (imidazole, oxazole, thiazole, and oxazoline). Herein we explore in detail through high-resolution pulsed electron paramagnetic resonance (EPR) and magnetic circular dichroism (MCD) spectroscopy in conjunction with density functional theory (DFT) the geometric and electronic structures of the mono- and dinuclear Cu(II) complexes of these cyclic pseudo hexapeptides. Orientation-selective hyperfine sublevel correlation, electron nuclear double resonance, and three-pulse electron spin echo envelope modulation spectroscopy of [Cu(II)(H2L(1))(MeOH)2](+) reveal delocalization of the unpaired electron spin onto the ligating and distal nitrogens of the coordinated heterocyclic rings and that they are magnetically inequivalent. DFT calculations confirm this and show similar spin densities on the distal heteroatoms in the heterocyclic rings coordinated to the Cu(II) ion in the other cyclic pseudo hexapeptide [Cu(II)(H2L(2,3,wa))(MeOH)2](+) complexes. The magnetic inequivalencies in [Cu(II)(H2L(1))(MeOH)2](+) arise from different orientations of the heterocyclic rings coordinated to the Cu(II) ion, and the delocalization of the unpaired electron onto the distal heteroatoms within these N-methylimidazole rings depends upon their location with respect to the Cu(II) d(x(2)-y(2)) orbital. A systematic study of DFT functionals and basis sets was undertaken to examine the ability to reproduce the experimentally determined spin Hamiltonian parameters. Inclusion of spin-orbit coupling (SOC) using MAG-ReSpect or ORCA with a BHLYP/IGLO-II Wachters setup with SOC corrections and ∼38% Hartree-Fock exchange gave the best predictions of the g and A((63)Cu) matrices. DFT calculations of the (14)N hyperfine and quadrupole parameters for the distal nitrogens of the coordinated heterocyclic rings in [Cu(II)(H2L(1))(MeOH)2](+) with the B1LYP functional and the SVP basis set were in excellent agreement with the experimental data, though other choices of functional and basis set also provided reasonable values. MCD, EPR, mass spectrometry, and DFT showed that preparation of the dinuclear Cu(II) complex in a 1:1 MeOH/glycerol mixture (necessary for MCD) resulted in the exchange of the bridging methoxide ligand for glycerol with a corresponding decrease in the magnitude of the exchange coupling.


Assuntos
Cobre/química , Imidazóis/química , Peptídeos Cíclicos/química , Fenômenos Eletromagnéticos , Modelos Moleculares , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray
10.
Inorg Chem ; 52(18): 10481-99, 2013 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-24011251

RESUMO

The temperature dependence of the structures of a wide range of mixed-cation Tutton's salts of general formula K2(x)Rb(2-2x)[Cu(H2O)6](SeO4)2 has been determined over the temperature range 90 to 320 K. Crystals with a high proportion of potassium adopt a different structure (form B) from those with a low ratio (form A). In both forms, the [Cu(H2O)6](2+) ion has an orthorhombically distorted tetragonally elongated coordination geometry, but the long and intermediate bonds occur with a different pair of water molecules in form A compared with form B. The alkali metal is surrounded by seven close oxygen atoms in form B but eight oxygen atoms in form A, and this difference in coordination number is associated with the change in the Cu-O bond distances via the hydrogen-bonding network. For crystals with between 32 and ∼41% potassium, a relatively sharp change from form B to A occurs on cooling, and the temperature at which this occurs increases approximately linearly as the proportion of potassium falls. For the whole range of mixed crystals, the bond lengths have been determined as a function of temperature. The data have been interpreted as a thermal equilibrium of the two structural forms of the [Cu(H2O)6](2+) ion that develops gradually as the temperature increases, with this becoming more pronounced as the proportions of the two cations become more similar. The temperature dependence of the bond lengths in this thermal equilibrium has been analyzed using a model in which the Jahn-Teller potential surface of the [Cu(H2O)6](2+) ion is perturbed by lattice strain interactions. The magnitude and sign of the orthorhombic component of this strain interaction depends upon the proportion of potassium to rubidium ions in the structure.

11.
BMJ Mil Health ; 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36997238

RESUMO

Since the February 2022 Russian invasion of Ukraine, the prospect of an Article 5 North Atlantic Treaty Organisation collective defence operation in Europe has increased significantly. Were this type of operation to occur, it would present different challenges to the Defence Medical Services (DMS) than those of the era of the International Security Assistance Force in Afghanistan, where air superiority was assured, and combat casualty numbers did not approach the tens of thousands experienced by Russia and Ukraine in the first months following the invasion. This essay examines how the DMS could prepare for such an operation using four key themes: preparing for prolonged field care, training medical personnel for combat, recruiting and retaining medical personnel and planning for post-traumatic stress disorder.

12.
JCO Clin Cancer Inform ; 7: e2200155, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36809022

RESUMO

PURPOSE: Develop a method for extracting smoking status and quantitative smoking history from clinician notes to facilitate cohort identification for low-dose computed tomography (LDCT) scanning for early detection of lung cancer. MATERIALS AND METHODS: A sample of 4,615 adult patients were randomly selected from the Multiparameter Intelligent Monitoring in Critical Care (MIMIC-III) database. The structured data were obtained by queries of the diagnosis tables using the International Classification of Diseases codes in use at that time. Unstructured data were drawn from clinician notes via natural language processing (NLP) using named entity recognition and our clinical data processing and extraction algorithms to identify two main clinical criteria for each smoking patient: (1) pack years smoked and (2) time from quit date (if applicable). A subset of 10% of the patient charts were manually reviewed for accuracy and precision. RESULTS: The structured data revealed 575 (12.5%) ever smokers (current plus past use). None of these patients had quantification of their smoking history, and 4,040 (87.5%) had no smoking information in the diagnosis tables; consequently, a cohort of patients eligible for LDCT could not be determined. Review of the physician notes by NLP disclosed 1,930 (41.8%) ever smokers of whom 537 were active smokers and 1,299 former smokers, and in 94 cases, it could not be determined if they were active or former smokers. A total of 1365 patients (29.6%) had no smoking data recorded. When the smoking and the age criteria for LDCT were applied to this group, 276 were found to be eligible for LDCT using the USPSTF criteria. As determined by clinician review, our F-score for identifying patients eligible for LDCT was 0.88. CONCLUSION: Unstructured data, obtained by NLP, can accurately identify a precise cohort that meets the USPSTF guidelines for LDCT.


Assuntos
Registros Eletrônicos de Saúde , Neoplasias Pulmonares , Adulto , Humanos , Fumar/efeitos adversos , Neoplasias Pulmonares/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Detecção Precoce de Câncer
13.
J Biol Chem ; 286(28): 24872-81, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21592966

RESUMO

SoxAX cytochromes catalyze the formation of heterodisulfide bonds between inorganic sulfur compounds and a carrier protein, SoxYZ. They contain unusual His/Cys-ligated heme groups with complex spectroscopic signatures. The heme-ligating cysteine has been implicated in SoxAX catalysis, but neither the SoxAX spectroscopic properties nor its catalysis are fully understood at present. We have solved the first crystal structure for a group 2 SoxAX protein (SnSoxAX), where an N-terminal extension of SoxX forms a novel structure that supports dimer formation. Crystal structures of SoxAX with a heme ligand substitution (C236M) uncovered an inherent flexibility of this SoxA heme site, with both bonding distances and relative ligand orientation differing between asymmetric units and the new residue, Met(236), representing an unusual rotamer of methionine. The flexibility of the SnSoxAX(C236M) SoxA heme environment is probably the cause of the four distinct, new EPR signals, including a high spin ferric heme form, that were observed for the enzyme. Despite the removal of the catalytically active cysteine heme ligand and drastic changes in the redox potential of the SoxA heme (WT, -479 mV; C236M, +85 mV), the substituted enzyme was catalytically active in glutathione-based assays although with reduced turnover numbers (WT, 3.7 s(-1); C236M, 2.0 s(-1)). SnSoxAX(C236M) was also active in assays using SoxYZ and thiosulfate as the sulfur substrate, suggesting that Cys(236) aids catalysis but is not crucial for it. The SoxYZ-based SoxAX assay is the first assay for an isolated component of the Sox multienzyme system.


Assuntos
Proteínas de Bactérias/química , Grupo dos Citocromos c/química , Bacilos e Cocos Aeróbios Gram-Negativos/enzimologia , Oxirredutases/química , Multimerização Proteica/fisiologia , Substituição de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Catálise , Domínio Catalítico/fisiologia , Cristalografia por Raios X , Grupo dos Citocromos c/genética , Grupo dos Citocromos c/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Bacilos e Cocos Aeróbios Gram-Negativos/genética , Heme/química , Heme/genética , Heme/metabolismo , Mutação de Sentido Incorreto , Oxirredutases/genética , Oxirredutases/metabolismo , Estrutura Quaternária de Proteína , Rhodobacter capsulatus/enzimologia , Rhodobacter capsulatus/genética , Relação Estrutura-Atividade
14.
Inorg Chem ; 51(4): 2065-78, 2012 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-22289382

RESUMO

A mixed-valence complex, [Fe(III)Fe(II)L1(µ-OAc)(2)]BF(4)·H(2)O, where the ligand H(2)L1 = 2-{[[3-[((bis(pyridin-2-ylmethyl)amino)methyl)-2-hydroxy-5-methylbenzyl](pyridin-2-ylmethyl)amino]methyl]phenol}, has been studied with a range of techniques, and, where possible, its properties have been compared to those of the corresponding enzyme system purple acid phosphatase. The Fe(III)Fe(II) and Fe(III)(2) oxidized species were studied spectroelectrochemically. The temperature-dependent population of the S = 3/2 spin states of the heterovalent system, observed using magnetic circular dichroism, confirmed that the dinuclear center is weakly antiferromagnetically coupled (H = -2JS(1)·S(2), where J = -5.6 cm(-1)) in a frozen solution. The ligand-to-metal charge-transfer transitions are correlated with density functional theory calculations. The Fe(III)Fe(II) complex is electron paramagnetic resonance (EPR)-silent, except at very low temperatures (<2 K), because of the broadening caused by the exchange coupling and zero-field-splitting parameters being of comparable magnitude and rapid spin-lattice relaxation. However, a phosphate-bound Fe(III)(2) complex showed an EPR spectrum due to population of the S(tot) = 3 state (J= -3.5 cm(-1)). The phosphatase activity of the Fe(III)Fe(II) complex in hydrolysis of bis(2,4-dinitrophenyl)phosphate (k(cat.) = 1.88 × 10(-3) s(-1); K(m) = 4.63 × 10(-3) mol L(-1)) is similar to that of other bimetallic heterovalent complexes with the same ligand. Analysis of the kinetic data supports a mechanism where the initiating nucleophile in the phosphatase reaction is a hydroxide, terminally bound to Fe(III). It is interesting to note that aqueous solutions of [Fe(III)Fe(II)L1(µ-OAc)(2)](+) are also capable of protein cleavage, at mild temperature and pH conditions, thus further expanding the scope of this complex's catalytic promiscuity.


Assuntos
Fosfatase Ácida/química , Compostos Férricos/química , Compostos Ferrosos/química , Glicoproteínas/química , Fosfatase Ácida/metabolismo , Animais , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Domínio Catalítico , Bovinos , Cristalografia por Raios X , Espectroscopia de Ressonância de Spin Eletrônica , Compostos Férricos/metabolismo , Compostos Ferrosos/metabolismo , Glicoproteínas/metabolismo , Hidrólise , Modelos Moleculares , Piridinas/química , Piridinas/metabolismo , Soroalbumina Bovina/metabolismo
15.
J Investig Med High Impact Case Rep ; 10: 23247096221074591, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35152792

RESUMO

Systemic sclerosis with negative serology, particularly that complicated by scleroderma renal crisis (SRC), is rarely encountered. We describe a patient with seronegative systemic sclerosis who developed acute kidney injury, proteinuria, and hypertensive emergency following motor vehicle-related trauma and in the setting of nonsteroidal anti-inflammatory drug use. Findings on physical examination, imaging, and skin biopsy led to a clinical diagnosis of scleroderma, despite the lack of supportive laboratory data. IgG lambda paraproteinemia was detected on workup. Bone marrow biopsy showed plasmacytosis and trace lambda-restricted plasma cells consistent with monoclonal gammopathy of undetermined significance. Chemotherapy was initially started given concern for myeloma with cast nephropathy but was later stopped after a kidney biopsy revealed thrombotic microangiopathy (TMA). The SRC associated with TMA was ultimately diagnosed, though atypical hemolytic uremic syndrome (aHUS) induced perhaps by monoclonal gammopathy or hypertension was also possible. Captopril and eculizumab were initiated for SRC and aHUS, respectively. Despite therapy, renal function did not recover, and the patient required hemodialysis indefinitely. This case highlights clinical features common to both SRC and aHUS as well as points out a few ways to differentiate between them.


Assuntos
Injúria Renal Aguda , Anemia Hemolítica , Síndrome Hemolítico-Urêmica Atípica , Gamopatia Monoclonal de Significância Indeterminada , Paraproteinemias , Púrpura Trombocitopênica Trombótica , Escleroderma Sistêmico , Microangiopatias Trombóticas , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Anemia Hemolítica/complicações , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Feminino , Humanos , Masculino , Gamopatia Monoclonal de Significância Indeterminada/complicações , Paraproteinemias/complicações , Escleroderma Sistêmico/complicações , Microangiopatias Trombóticas/etiologia
16.
Appl Environ Microbiol ; 77(8): 2813-6, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21357435

RESUMO

This study evaluated real-time sensing of Escherichia coli as a microbial contaminant in water distribution systems. Most sensors responded to increased E. coli concentrations, showing that select sensors can detect microbial water quality changes and be utilized as part of a contaminant warning system.


Assuntos
Monitoramento Ambiental , Escherichia coli/isolamento & purificação , Água Doce/microbiologia , Contagem de Colônia Microbiana , Escherichia coli/crescimento & desenvolvimento , Microbiologia da Água , Abastecimento de Água
17.
Inorg Chem ; 50(18): 9178-83, 2011 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-21812394

RESUMO

In the treatment of chronic iron overload disorders, ligands capable of complexing so-called "labile" (nonprotein bound) Fe are required to enter iron-loaded cells, sequester excess Fe, and then exit the cell (and the body) as an intact Fe complex. Despite the emergence of several ligand families that show high activity in mobilizing intracellular Fe, the mechanism and the locations of these subcellular labile Fe pools are still poorly understood. Our previous studies have unearthed a class of heterocyclic hydrazine-based chelators (e.g., benzoyl picolinoyl hydrazine, H(2)BPH) that show excellent activity at mobilizing Fe from Fe-loaded cells. Herein, we have grafted a fluorescent tag (rhodamine B) onto H(2)BPH to generate a ligand (L(1)) that is nonfluorescent in its uncomplexed form but becomes strongly fluorescent in complex with Fe(III). The free ligand and its 1:2 Fe complex [Fe(III)(L(1))(2)](3+) have both been fully characterized spectroscopically and with X-ray crystallography. Confocal fluorescent microscopy of HeLa cells incubated with [Fe(III)(L(1))(2)](3+) shows that the complex rapidly enters HeLa cells and localizes within endosomes/lysosomes.


Assuntos
Corantes Fluorescentes/química , Hidrazinas/química , Quelantes de Ferro/química , Rodaminas/química , Permeabilidade da Membrana Celular , Cristalografia por Raios X , Endossomos/metabolismo , Corantes Fluorescentes/metabolismo , Células HeLa , Humanos , Hidrazinas/metabolismo , Quelantes de Ferro/metabolismo , Ligantes , Lisossomos/metabolismo , Modelos Moleculares , Rodaminas/metabolismo
18.
Inorg Chem ; 50(11): 4900-16, 2011 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21539359

RESUMO

The crystal structures of trans-diaquabis(methoxyacetato)copper(II) and the isostructural nickel(II) complex have been determined over a wide temperature range. In conjunction with the reported behavior of the g-values, the structural data suggest that the copper(II) compound exhibits a thermal equilibrium between three structural forms, two having orthorhombically distorted, tetragonally elongated geometries but with the long and intermediate bonds to different atoms, and the third with a tetragonally compressed geometry. This is apparently the first reported example of a copper(II) complex undergoing an equilibrium between tetragonally elongated and compressed forms. The optical spectrum of single crystals of the copper(II) compound is used to obtain metal-ligand bonding parameters which yield the g-values of the compressed form of the complex and hence the proportions of the complex in each structural form at every temperature. When combined with estimates of the Jahn-Teller distortions of the different forms, the latter produce excellent agreement with the observed temperature dependence of the bond lengths. The behavior of an infrared combination band is consistent with such a thermal equilibrium, as is the temperature dependence of the thermal ellipsoid parameters and the XAFS. The potential surfaces of the different forms of the copper(II) complex have been calculated by a model based upon Jahn-Teller coupling. It is suggested that cooperative effects may cause the development of the population of tetragonally compressed complexes, and the crystal packing is consistent with this hypothesis, though the present model may oversimplify the diversity of structural forms present at high temperature.

19.
BMJ Case Rep ; 14(6)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34167976

RESUMO

We describe the case of a patient who presented with symptoms of persistent headaches, left-sided facial pain and blurry vision of the left eye. The patient had recovered from a herpes zoster infection of the V1 division of the trigeminal nerve 1 month prior. Serum inflammatory markers were elevated, raising concern for temporal arteritis. Empiric high-dose prednisone was initiated. Bilateral temporal artery biopsies were performed but did not show evidence of vasculitis or multinucleated giant cells. Instead, extracellular material deposits were present within the vessel walls. Congo red staining was diagnostic for amyloidosis. Liquid chromatography and mass spectrometry identified the amyloid fibrils to be transthyretin-type (ATTR) consistent with age-related amyloidosis. Temporal artery involvement of amyloidosis is rare but when present is most often due to light chain amyloidosis. Based on our review of the literature, only a few cases of temporal artery ATTR amyloidosis have been reported.


Assuntos
Neuropatias Amiloides Familiares , Arterite de Células Gigantes , Herpes Zoster , Arterite de Células Gigantes/diagnóstico , Arterite de Células Gigantes/tratamento farmacológico , Herpes Zoster/complicações , Herpes Zoster/diagnóstico , Herpes Zoster/tratamento farmacológico , Humanos , Pré-Albumina
20.
Opt Express ; 18(25): 26754-9, 2010 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-21165025

RESUMO

Novel telluride glasses with high electrical conductivity, wide infrared transparency and good resistance to crystallization are used to design an opto-electrophoretic sensor for detection and identification of hazardous microorganisms. The sensor is based on an attenuated total reflectance element made of Ge-As-Te glass that serves as both an optical sensing zone and an electrode for driving the migration of bio-molecules within the evanescent wave of the sensor. An electric field is applied between the optical element and a counter electrode in order to induce the migration of bio-molecules carrying surface charges. The effect of concentration and applied voltage is tested and the migration effect is shown to be reversible upon switching the electric field. The collected signal is of high quality and can be used to identify different bacterial genus through statistical spectral analysis. This technique therefore provides the ability to detect hazardous microorganisms with high specificity and high sensitivity in aqueous environments. This has great potential for online monitoring of water quality.


Assuntos
Biopolímeros/análise , Técnicas Biossensoriais/instrumentação , Calcogênios/química , Condutometria/instrumentação , Eletroforese/instrumentação , Tecnologia de Fibra Óptica/instrumentação , Refratometria/instrumentação , Condutividade Elétrica , Desenho de Equipamento , Análise de Falha de Equipamento , Vidro/química
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