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1.
J Inorg Biochem ; 257: 112593, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38754275

RESUMO

Four Ru(II) complexes (A2-A5) were synthesized from the reaction of coumarin Schiff base ligands (7da2-tsc, 7da3-mtsc, 7da4-etsc and 7da5-ptsc) with [RuHCl(CO)(PPh3)3]. The compounds were characterized by FT-IR, UV-Vis, 1H, 13C and 31P NMR, mass spectrometry and crystallographic analysis. Calf Thymus DNA (CT-DNA) binding studies revealed the intercalative mode of binding of the complexes with DNA. The results of Bovine serum albumin (BSA) binding studies established the interaction between BSA followed static quenching mechanism. The cytotoxic effects of the complexes and the ligands were evaluated against breast (MCF-7 and MDA-MB-231) and lung carcinoma cell lines (A549 and NCI-H460) using MTT assay. Complex A4 demonstrated potent cytotoxic effects on both breast and lung cancer cells. Furthermore, morphological observations and FACS analysis showed the decrease in cell density by complex A4 by induced morphological changes and apoptotic body formation and cell death in both breast and lung cancer cells. Moreover, the invertebrate model Caenorhabditis elegans was employed to assess the in vivo anticancer activity of compound A4. The findings indicated that the treatment with A4 reduced tumor development and significantly extended organismal lifespan by 64 % in the tumoral strain JK1466 without adversely affecting essential physiological functions of the worm. Additionally, A4 demonstrated an upregulation of two crucial antioxidant defense genes. Overall, these results suggested that the compound A4 can be a potential candidate with novel chemotherapeutic applications.


Assuntos
Antineoplásicos , Caenorhabditis elegans , Complexos de Coordenação , Rutênio , Animais , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Rutênio/química , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Linhagem Celular Tumoral , Mutação , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , DNA/química , Células MCF-7
2.
Health Care Women Int ; : 1-20, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35834362

RESUMO

Body mapping is an arts-based research technique that uses a life-sized outline of the participant's body and symbols that visually represent their lived experiences. In this article, we describe the methods of body mapping and analytic techniques used in a research inquiry exploring how child abuse influenced the embodied processes in anorexia. We aim to contribute to methodological research practice in anorexia using a method that can potentially add value in other areas of ED research or be adapted for treatment settings. Our research findings suggest that body mapping can add value to the interview method and extend the range of methods for researchers interested in interrogating the hard-to-reach subjective embodied processes.

3.
RSC Adv ; 8(3): 1539-1561, 2018 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-35540910

RESUMO

New cyclometallated ruthenium(ii) complexes of 3-acetyl-7-methoxycoumarin-4N-substituted thiosemicarbazones were synthesized and characterized by analytical and spectral techniques. The crystal structures of the ligands H2L1-3 and complexes (1, 2 and 4) were confirmed by X-ray crystallography. The analysis showed that the ligands have undergone C-H activation at the C(4) carbon of the pyrone ring and acted in a tridentate fashion by binding through C, N and S atoms. CT-DNA and protein (BSA/HSA) binding studies were carried out to analyze their interaction with biomolecules. Good binding affinity with DNA was observed with intercalative binding mode, which was further confirmed by EB displacement and viscosity measurement studies. The quenching mechanism with BSA/HSA was found to be static. Three dimensional (3D) fluorescence measurements were carried out to validate the micro environmental changes in the serum albumins. Their antioxidant propensity and antimicrobial study insisted that the compounds displayed good spectrum of activity. Evaluation of their anticancer potential against MCF-7 (human breast cancer) and A549 (human lung carcinoma) cell lines revealed that the complexes exhibited better activity than the ligands and cisplatin. Further, the results of LDH and NO release assays supported the cytotoxic nature of the compounds. The non-toxic nature of the compounds was established by testing against the non-cancerous cell line HaCaT (human normal keratinocyte).

4.
Dalton Trans ; 43(15): 5759-76, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24573149

RESUMO

Novel p-tolylimido rhenium(v) complexes trans-(Cl,Cl)-[Re(p-NC6H4CH3)Cl2(pyz-2-COO)(PPh3)]·MeCN (1), trans-(Cl,Cl)-[Re(p-NC6H4CH3)Cl2(pyz-2-COO)(PPh3)] (2), trans-(Br,Br)-[Re(p-NC6H4CH3)Br2(pyz-2-COO)(PPh3)] (3), cis-(Cl,Cl)-[Re(p-NC6H4CH3)Cl2(ind-3-COO)(PPh3)]·2MeOH (4), 2[Re(p-NC6H4CH3)Cl2(ind-3-COO)(PPh3)]·MeCN (5), 2[Re(p-NC6H4CH3)Br2(ind-3-COO)(PPh3)]·MeOH (6) and 2[Re(p-NC6H4CH3)Br2(ind-3-COO)(PPh3)]·MeCN (7) were obtained in the reactions of [Re(p-NC6H4CH3)X3(PPh3)2] (X = Cl, Br) with pyrazine-2-carboxylic (pyz-2-COOH or PCA) and indazole-3-carboxylic (ind-3-COOH) acids. The compounds were identified by elemental analysis, IR, (1)H, (13)C and (31)P NMR spectroscopy and X-ray crystallography. To get a deeper understanding of the structural and bonding properties of the imido rhenium(v) complexes, calculations at the DFT level were undertaken for trans-(Cl,Cl)-[Re(p-NC6H4CH3)Cl2(pyz-2-COO)(PPh3)] and cis-(Cl,Cl)-[Re(p-NC6H4CH3)Cl2(ind-3-COO)(PPh3)]. Complexes 1, 3, 4 and 6 exhibited high catalytic activity in oxidation of alkanes with H2O2 and tert-butyl hydroperoxide (TBHP) and of alcohols with TBHP. The selectivity parameters measured in the reactions with linear and branched alkanes indicated that the processes with H2O2 or TBHP proceed with the participation of hydroxyl or tert-butoxyl radicals, respectively. The composition of isomers from oxygenation of methylcyclohexane corresponds to the existence of some steric hindrance around the reaction centers.

5.
Phys Rev E Stat Nonlin Soft Matter Phys ; 69(6 Pt 2): 066208, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15244709

RESUMO

The results of our study of the motion of a three particle, self-gravitating system in general relativistic lineal gravity is presented for an arbitrary ratio of the particle masses. We derive a canonical expression for the Hamiltonian of the system and discuss the numerical solution of the resulting equations of motion. This solution is compared to the corresponding nonrelativistic and post-Newtonian approximation solutions so that the dynamics of the fully relativistic system can be interpreted as a correction to the one-dimensional Newtonian self-gravitating system. We find that the structure of the phase space of each of these systems yields a large variety of interesting dynamics that can be divided into three distinct regions: annulus, pretzel, and chaotic; the first two being regions of quasiperiodicity while the latter is a region of chaos. By changing the relative masses of the three particles we find that the relative sizes of these three phase space regions changes, and that this deformation can be interpreted physically in terms of the gravitational interactions of the particles. Furthermore, we find that many of the interesting characteristics found in the case where all of the particles share the same mass also appear in our more general study. We find that there are additional regions of chaos in the unequal mass system which are not present in the equal mass case. We compare these results to those found in similar systems.

6.
Phys Rev E Stat Nonlin Soft Matter Phys ; 69(1 Pt 2): 016214, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14995700

RESUMO

We consider the problem of three-body motion for a relativistic one-dimensional self-gravitating system. After describing the canonical decomposition of the action, we find an exact expression for the three-body Hamiltonian, implicitly determined in terms of the four coordinates and momentum degrees of freedom in the system. Nonrelativistically these degrees of freedom can be rewritten in terms of a single particle moving in a two-dimensional hexagonal well. We find the exact relativistic generalization of this potential, along with its post-Newtonian approximation. We then specialize to the equal-mass case and numerically solve the equations of motion that follow from the Hamiltonian. Working in hexagonal-well coordinates, we obtain orbits in both the hexagonal and three-body representations of the system, and plot the Poincaré sections as a function of the relativistic energy parameter eta. We find two broad categories of periodic and quasiperiodic motions that we refer to as the annulus and pretzel patterns, as well as a set of chaotic motions that appear in the region of phase space between these two types. Despite the high degree of nonlinearity in the relativistic system, we find that the global structure of its phase space remains qualitatively the same as its nonrelativistic counterpart for all values of eta that we could study. However, the relativistic system has a weaker symmetry and so its Poincare section develops an asymmetric distortion that increases with increasing eta. For the post-Newtonian system we find that it experiences a chaotic transition in the interval 0.21

7.
Emerg Infect Dis ; 7(6): 933-44, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11747719

RESUMO

From October 4 to November 2, 2001, the first 10 confirmed cases of inhalational anthrax caused by intentional release of Bacillus anthracis were identified in the United States. Epidemiologic investigation indicated that the outbreak, in the District of Columbia, Florida, New Jersey, and New York, resulted from intentional delivery of B. anthracis spores through mailed letters or packages. We describe the clinical presentation and course of these cases of bioterrorism-related inhalational anthrax. The median age of patients was 56 years (range 43 to 73 years), 70% were male, and except for one, all were known or believed to have processed, handled, or received letters containing B. anthracis spores. The median incubation period from the time of exposure to onset of symptoms, when known (n=6), was 4 days (range 4 to 6 days). Symptoms at initial presentation included fever or chills (n=10), sweats (n=7), fatigue or malaise (n=10), minimal or nonproductive cough (n=9), dyspnea (n=8), and nausea or vomiting (n=9). The median white blood cell count was 9.8 X 10(3)/mm(3) (range 7.5 to 13.3), often with increased neutrophils and band forms. Nine patients had elevated serum transaminase levels, and six were hypoxic. All 10 patients had abnormal chest X-rays; abnormalities included infiltrates (n=7), pleural effusion (n=8), and mediastinal widening (seven patients). Computed tomography of the chest was performed on eight patients, and mediastinal lymphadenopathy was present in seven. With multidrug antibiotic regimens and supportive care, survival of patients (60%) was markedly higher (<15%) than previously reported.


Assuntos
Antraz/fisiopatologia , Bioterrorismo , Exposição por Inalação/efeitos adversos , Adulto , Idoso , Antraz/epidemiologia , Antraz/transmissão , Bacillus anthracis/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos/epidemiologia
8.
J Biol Chem ; 275(12): 8480-6, 2000 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-10722684

RESUMO

Cyclic AMP receptor protein (CRP) regulates the expression of several genes in Escherichia coli. The ability of CRP to bind specific DNA sequences and stimulate transcription is achieved as result of binding of an allosteric ligand: cAMP. Stopped-flow fluorimetry was employed to study the kinetics of the conformational changes in CRP induced by cAMP binding to high and low affinity receptor sites. Results of experiments using CRP labeled at Cys-178 with 1,5-I-AENS indicate change in conformation of the helix-turn-helix, occurring after the formation of CRP-cAMP(2) complex, i.e. after saturation of the high affinity sites. The observed conformational change occurs according to sequential model of allostery and is described by rate constants: k(c) = 9.7 +/- 0.1 s(-1) and k(-c) = 0.31 +/- 0.05 s(-1), for the forward and backward reaction, respectively. Results of experiments monitored using CRP intrinsic fluorescence suggest that conformational change precedes the formation of CRP-cAMP(4) complex and results from displacement of equilibrium between two forms of CRP-cAMP(2), caused by binding of cAMP to low affinity sites of one of these forms only. The observed conformational change occurs according to concerted model of allostery and is described by rate constants: k(on) = 28 +/- 1.5 s(-1) and k(off) = 75.5 +/- 3 s(-1). Results of experiments using single-tryptophan-containing CRP mutants indicate that Trp-85 is mainly responsible for the observed total change in intrinsic fluorescence of wild-type CRP.


Assuntos
Proteínas de Bactérias/efeitos dos fármacos , Proteína Receptora de AMP Cíclico/efeitos dos fármacos , AMP Cíclico/farmacologia , Proteínas de Ligação a DNA/efeitos dos fármacos , Regulação Alostérica , Escherichia coli , Análise de Injeção de Fluxo , Cinética , Modelos Teóricos , Conformação Proteica/efeitos dos fármacos , Espectrometria de Fluorescência , Termodinâmica , Triptofano/química
9.
Neuroepidemiology ; 19(2): 62-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10686530

RESUMO

Iatrogenic Creutzfeldt-Jakob disease (CJD) has never been reported among recipients of dura mater grafts processed in the US. We recently investigated a report of such a case in a 72-year-old man with a typical clinical presentation of CJD. We found no evidence of CJD in either the 34-year-old donor or in other, proximal patients undergoing craniotomies. Although the graft may have caused the illness, sporadic CJD is a more likely explanation, with the graft being coincidental.


Assuntos
Síndrome de Creutzfeldt-Jakob/transmissão , Dura-Máter/transplante , Adulto , Idoso , Síndrome de Creutzfeldt-Jakob/epidemiologia , Humanos , Doença Iatrogênica , Masculino , Estados Unidos/epidemiologia
10.
Public Health Rep ; 114(5): 427-38, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10590765

RESUMO

OBJECTIVES: Until 1995, infection with Cyclospora cayetanenis, a parasite that causes gastroenteritis, was diagnosed in the US primarily in overseas travelers; its modes of transmission were largely unknown. In 1995, 45 cases of cyclosporiasis were diagnosed in Florida residents who had no history of recent foreign travel, but an investigation could not pinpoint a source for the parasite. In 1996, a North American outbreak of cyclosporiasis resulted in more than 1400 cases, 180 of them in Florida. The authors investigated the 1996 Florida outbreak to identify the vehicle of transmission. METHODS: The authors conducted a matched case-control study in which each of 86 laboratory-confirmed sporadic cases was matched with up to four controls. They also investigated nine clusters of cases associated with common meals and attempted to trace implicated foods to their countries of origin. RESULTS: In the case control study, eating raspberries was strongly associated with cyclosporiasis (matched odds ratio = 31.9; 95% confidence interval [CI] 7.4, 138.2). In the cluster investigation, raspberries were the only food common to all nine clusters of cases; a summary analysis showed a strong association between consumption of raspberries and confirmed or probable cyclosporiasis (risk ratio = 17.6; 95% CI 1.9, 188.8). Guatemala was the sole country of origin for raspberries served at six of nine events. CONCLUSIONS: Guatemalan raspberries were the vehicle for the 1996 Florida cyclosporiasis outbreak. Cyclospora is a foodborne pathogen that may play a growing role in the etiology of enteric disease in this country as food markets become increasingly international.


Assuntos
Surtos de Doenças , Frutas/parasitologia , Enteropatias Parasitárias/epidemiologia , Adulto , Estudos de Casos e Controles , Análise por Conglomerados , Feminino , Florida/epidemiologia , Humanos , Enteropatias Parasitárias/transmissão , Masculino , Pessoa de Meia-Idade , Estações do Ano
11.
J Mol Biol ; 287(1): 47-57, 1999 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-10074406

RESUMO

The apurinic/apyrimidinic endonucleases (APE) contain several highly conserved sequence motifs. The glutamic acid residue in a consensus motif, LQE96TK98 in human APE (hAPE-1), is crucial because of its role in coordinating Mg2+, an essential cofactor. Random mutagenesis of the inactive E96A mutant cDNA, followed by phenotypic screening in Escherichia coli, led to isolation of an intragenic suppressor with a second site mutation, K98R. Although the Km of the suppressor mutant was about sixfold higher than that of the wild-type enzyme, their kcat values were similar for AP endonuclease activity. These results suggest that the E96A mutation affects only the DNA-binding step, but not the catalytic step of the enzyme. The 3' DNA phosphoesterase activities of the wild-type and the suppressor mutant were also comparable. No global change of the protein conformation is induced by the single or double mutations, but a local perturbation in the structural environment of tryptophan residues may be induced by the K98R mutation. The wild-type and suppressor mutant proteins have similar Mg2+ requirement for activity. These results suggest a minor perturbation in conformation of the suppressor mutant enabling an unidentified Asp or Glu residue to substitute for Glu96 in positioning Mg2+ during catalysis. The possibility that Asp70 is such a residue, based on its observed proximity to the metal-binding site in the wild-type protein, was excluded by site-specific mutation studies. It thus appears that another acidic residue coordinates with Mg2+ in the mutant protein. These results suggest a rather flexible conformation of the region surrounding the metal binding site in hAPE-1 which is not obvious from the X-ray crystallographic structure.


Assuntos
Carbono-Oxigênio Liases/genética , Domínio Catalítico/genética , Proteínas de Escherichia coli , Mutação de Sentido Incorreto , Supressão Genética , Carbono-Oxigênio Liases/química , Carbono-Oxigênio Liases/efeitos dos fármacos , Carbono-Oxigênio Liases/metabolismo , Cátions Bivalentes/farmacologia , DNA Liase (Sítios Apurínicos ou Apirimidínicos) , Desoxirribonuclease IV (Fago T4-Induzido) , Escherichia coli/genética , Humanos , Magnésio/farmacologia , Mutagênese Sítio-Dirigida , Estrutura Secundária de Proteína , Proteínas Recombinantes
12.
Am J Trop Med Hyg ; 59(2): 235-42, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9715939

RESUMO

Before 1995, only one outbreak of cyclosporiasis had been reported in the United States. To identify risk factors for Cyclospora infection acquired in Florida in 1995, we conducted a matched case-control study (24 sporadic cases and 69 controls) and retrospective cohort studies of clusters of cases associated with two May social events (attack rates = 15.4% [8 of 52] and 54.5% [6 of 11]). In univariate analysis of data from the case-control study, consumption of fresh raspberries (odds ratio [OR] = 6.0, 95% confidence interval [CI] = 1.1-31.7) and bare-handed contact with soil (OR = 5.4, 95% CI = 1.4-20.7) were associated with infection; soil contact was also implicated in multivariate analysis. For the events, mixed-fruit items that had only fresh raspberries and strawberries in common had elevated relative risks (3.7 and 4.2), but the confidence intervals overlapped 1.0. The raspberries eaten at the events and by sporadic case-patients were imported. Given the cumulative evidence of the three studies and the occurrence in 1996 and 1997 of outbreaks in North America associated with consumption of Guatemalan raspberries, food-borne transmission of Cyclospora was likely in 1995 in Florida as well.


Assuntos
Coccidiose/epidemiologia , Diarreia/epidemiologia , Surtos de Doenças , Eucoccidiida/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Diarreia/parasitologia , Ingestão de Líquidos , Fezes/parasitologia , Feminino , Florida/epidemiologia , Frutas , Humanos , Lactente , Masculino , Esterco , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Solo
13.
J Protein Chem ; 17(3): 219-28, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9588945

RESUMO

Kinetic measurements of denaturation and renaturation of two mutants of cAMP receptor protein (CRP) at position 128, namely Ser --> Ala and Ser --> Pro, were performed in order to assess changes introduced by the mutation in the quaternary structure and protein stability. No significant changes were found in the unfolding/refolding reactions. However, small perturbations in the dissociation of CRP dimer can be seen, which indicate that subunit interactions are influenced by the mutation. Studies of intrinsic fluorescence quenching of these two mutants are also reported, showing changes compared with wild-type protein. Near-UV circular dichroism measurements indicate, however, that Trp residues remain in the same environment as in the wild-type CRP. It is proposed that Ser at position 128 is involved in maintaining the proper domain alignment within CRP subunits.


Assuntos
Proteína Receptora de AMP Cíclico/química , Escherichia coli/química , Dobramento de Proteína , Serina/química , Dicroísmo Circular , Mutação , Conformação Proteica , Desnaturação Proteica
14.
J Protein Chem ; 17(8): 745-55, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9988521

RESUMO

cAMP receptor protein (CRP) regulates expression of a number of genes in Escherichia coli. The protein is a homodimer and each monomer is folded into two structural domains. The biological activation of CRP upon cAMP binding may involve the subunit realignment as well as reorientation between the domains within each subunit. In order to study the interactions between the subunits or domains, we performed stopped-flow measurements of the guanidine hydrochloride (GuHCI)-induced denaturation of CRP. The changes in CRP structure induced by GuHCl were monitored using both intrinsic Trp fluorescence as well as the fluorescence of an extrinsic probe, 8-anilino-1-Naphthalenesulfonic acid (ANS). Results of CRP denaturation using Trp fluorescence detection are consistent with a two-step model [Malecki, and Wasylewski, (1997), Eur. J. Biochem. 243, 660], where the dissociation of dimer into subunits is followed by the monomer unfolding. The denaturation of CRP monitored by ANS fluorescence reveals the existence of two additional processes. One occurs before the dissociation of CRP into subunits, whereas the second takes place after the dissociation, but prior to proper subunit unfolding. These additional processes suggest that CRP denaturation is described by a more complicated mechanism than a simple three-state equilibrium and may involve additional changes in both inter- and intrasubunit interactions. We also report the effect of cAMP on the kinetics of CRP subunit unfolding and refolding.


Assuntos
Escherichia coli/química , Guanidina/farmacologia , Receptores de AMP Cíclico/química , Receptores de AMP Cíclico/metabolismo , Espectrometria de Fluorescência/métodos , Naftalenossulfonato de Anilina/química , Naftalenossulfonato de Anilina/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Dimerização , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Guanidina/química , Guanidina/metabolismo , Cinética , Desnaturação Proteica/efeitos dos fármacos , Dobramento de Proteína , Receptores de AMP Cíclico/efeitos dos fármacos
15.
Eur J Biochem ; 243(3): 660-9, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9057829

RESUMO

cAMP receptor protein (CRP) is involved in regulation of expression of several genes in Escherichia coli. The protein is a homodimer and each monomer is folded into two distinct structural domains. The mechanism of the biological activity of the protein may involve the interaction between the subunits and domains. In order to determine the interaction between the subunits or domains of CRP, we have studied the reversible denaturation of the protein by guanidine hydrochloride. The unfolding and refolding kinetics of CRP was monitored using stopped-flow fluorescence spectroscopy at 20 degrees C and pH 7.9. The results of CRP denaturation indicate that the transition can be described by a three-state model: (CRP native)2<=> 2 (CRP native)<=>2 (CRP denatured). The faster process, characterized by the relaxation time tau 2 = 80 +/- 3 ms, corresponds to the dissociation of CRP dimer into monomers. The slower process has the relaxation time tau t = 1.9 +/- 0.1 s and corresponds to the cooperative unfolding of CRP monomer. The free energy change in the absence of denaturant upon CRP dissociation is delta G dis degrees = 46.9 +/- 2.5 kJ/mol and for monomer unfolding delta G unf degrees = 30.9 +/- 1.3 kJ/mol. The thermal unfolding of CRP was studied by circular dichroism and fluorescence spectroscopy at various guanidine hydrochloride concentrations. It has been found that the native protein is maximally stable at about 21 +/- 0.3 degrees C and is denatured upon heating and cooling from this temperature. The apparent free energy change for CRP unfolding at 21 degrees C is equal to 30.5 +/- 0.4 kJ/mol and the apparent specific heat change is equal to delta Cp, app = 10.7 +/- 0.7 kJ mol-1 K-1. The predicted values of cold denaturation midpoint is equal to tau G = -18.8 +/- 1.5 degrees C and for high-temperature transition tau G = 63.1 +/- 1.5 degrees C. The predicted midpoint of high-temperature unfolding transition is about the same as determined experimentally.


Assuntos
Escherichia coli/metabolismo , Dobramento de Proteína , Receptores de AMP Cíclico/química , Receptores de AMP Cíclico/metabolismo , Dicroísmo Circular , Estabilidade de Medicamentos , Escherichia coli/química , Guanidina , Guanidinas/farmacologia , Cinética , Desnaturação Proteica , Receptores de AMP Cíclico/efeitos dos fármacos , Termodinâmica
16.
Public Health Rep ; 112(1): 59-62, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9018290

RESUMO

OBJECTIVE: A prospective cohort study was performed to identify risk factors for seabather's eruption. METHODS: Study participants were recruited at four beaches in Palm Beach County, Florida, during three weekends of May and June 1993. Participants were interviewed by telephone after 48 hours regarding medical history, beach activities, development of rashes, and use of possible preventive measures. RESULTS: Seabather's eruption, defined by the occurrence of a rash within two days of exposure to seawater, was reported by 114 (16%) of 735 respondents. The strongest predictor of seabather's eruption was a past history of the condition. Children less than 16 years of age were also at increased risk, as were surfers. Showering with one's bathing suit off was a useful protective measure. CONCLUSION: The study's findings suggest that when the seasonal risk of seabather's eruption is present, children, people with a history of seabather's eruption, and surfers are at greatest risk. During the sea lice season, seabathers can minimize their risk by showering with their bathing suits off after seabathing. Length of the time spent in water was not significantly associated with seabather's eruption.


Assuntos
Dermatite/etiologia , Cifozoários , Água do Mar/efeitos adversos , Natação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Dermatite/prevenção & controle , Feminino , Florida , Humanos , Lactente , Larva , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Estações do Ano , Inquéritos e Questionários , Fatores de Tempo
17.
J Public Health Policy ; 17(2): 153-69, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8764389

RESUMO

Experience in developing a local public health program, covering a period of approximately 45 years, is described. Included are the assessment and analysis of problems, policy formulation, plan development, and program implementation. A study of problems of seasonal farm workers, particularly those who migrate, is described, as well as a health services delivery program based on this study. Attention is given to incorporation of medical care with core public health services, and the use of a multidisciplinary team. Special features required to overcome cultural, language, educational, and other barriers are outlined. Adaption of knowledge gained from the migrant health project toward meeting needs of the county's medically underserved population is described. Involvement of the community, including representatives of private and public sectors, in the development and implementation of plans is emphasized. Maintaining appropriate emphasis on preventive aspects is discussed, together with mobilization of financial and other support. The importance of qualified public health staff is also emphasized: residency programs for physicians and dentists and training for other personnel are described.


Assuntos
Reforma dos Serviços de Saúde/legislação & jurisprudência , Acessibilidade aos Serviços de Saúde/legislação & jurisprudência , Saúde Pública/legislação & jurisprudência , Florida , Implementação de Plano de Saúde/legislação & jurisprudência , Humanos , Indigência Médica/legislação & jurisprudência , Crescimento Demográfico , Planos Governamentais de Saúde/legislação & jurisprudência , Migrantes/legislação & jurisprudência , Estados Unidos
18.
J Protein Chem ; 14(5): 299-308, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8590598

RESUMO

Time-resolved, steady-state fluorescence and fluorescence-detected circular dichroism (FDCD) have been used to resolve the fluorescence contributions of the two tryptophan residues, Trp-13 and Trp-85, in the cyclic AMP receptor protein (CRP). The iodide and acrylamide quenching data show that in CRP one tryptophan residue, Trp-85, is buried within the protein matrix and the other, Trp-13, is moderately exposed on the surface of the protein. Fluorescence-quenching-resolved spectra show that Trp-13 has emission at about 350 nm and contributes 76-83% to the total fluorescence emission. The Trp-85, unquenchable by iodide and acrylamide, has the fluorescence emission at about 337 nm. The time-resolved fluorescence measurements show that Trp-13 has a longer fluorescence decay time. The Trp-85 exhibits a shorter fluorescence decay time. In the CRP-cAMP complex the Trp-85, previously buried in the apoprotein becomes totally exposed to the iodide and acrylamide quenchers. The FDCD spectra indicate that in the CRP-cAMP complex Trp-85 remains in the same environment as in the protein alone. It has been proposed that the binding of cAMP to CRP is accompanied by a hinge reorientation of two protein domains. This allows for penetration of the quencher molecules into the Trp-85 residue previously buried in the protein matrix.


Assuntos
Proteínas de Bactérias/análise , Proteína Receptora de AMP Cíclico/análise , Escherichia coli/química , Acrilamida , Acrilamidas/farmacologia , Dicroísmo Circular , AMP Cíclico/farmacologia , Fluorescência , Iodetos/farmacologia , Cinética , Conformação Proteica , Espectrometria de Fluorescência , Triptofano/análise
19.
Toxicon ; 33(1): 99-104, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7778134

RESUMO

Thirty-six of 44 patients with seabather's eruption had specific IgG antibodies against Linuche unguilata (thimble jelly) medusae antigen. ELISA detected antibodies in serum stored for 10 years. The extent of the cutaneous eruption or sting severity was correlated with antibody titer. Antibodies were detected in patients acquiring the eruption in Florida, the Bahamas and Aruba, reflecting the habitat of these jellyfish. This serological assay can be useful to confirm the clinical diagnosis.


Assuntos
Anticorpos/sangue , Cifozoários/imunologia , Dermatopatias/imunologia , Natação , Adulto , Idoso , Animais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Am J Dis Child ; 146(10): 1166-70, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1415043

RESUMO

OBJECTIVE: To describe the factors underlying an increasing incidence of tuberculosis in children. DESIGN: Descriptive case review. SETTING: Palm Beach County, Fla. PARTICIPANTS: Forty-four children with suspected and confirmed pediatric tuberculosis from 1985 through 1989. INTERVENTIONS: None. MEASUREMENTS/MAIN RESULTS: From 1988 through 1989, tuberculosis was confirmed in 15 children and suspected in another 16 compared with data from 1985 through 1987 in which the disease was confirmed in nine children and suspected in four. Pediatric tuberculosis occurred primarily in blacks younger than 5 years; the increase in the number of cases reported in 1988 and 1989 occurred only in blacks. One child in whom tuberculosis was confirmed during the recent period was infected with the human immunodeficiency virus (HIV); however, among children with suspected tuberculosis, four of the nine children tested were seropositive for HIV. There was no evidence of increased transmission of tuberculosis to children by HIV-seropositive adults compared with transmission by HIV-seronegative adults with TB. New adult tuberculosis cases in the county increased annually, from 92 cases in 1986 to 169 in 1989, of whom at least 36% were infected with HIV. CONCLUSIONS: The largest effect of the HIV epidemic on tuberculosis in children appeared to be indirect, through an increase in the number of adults with active tuberculosis serving as potential sources of tuberculosis infection for children. A direct effect of HIV infection in the progression of tuberculous disease in children is likely, but was not detected in this investigation. Case-finding for tuberculosis among children will need to increase, particularly in areas heavily affected by acquired immunodeficiency syndrome, but may be complicated by the difficulty of diagnosing tuberculosis in HIV-infected children.


Assuntos
Infecções por HIV/epidemiologia , HIV-1 , Tuberculose/epidemiologia , Adolescente , Fatores Etários , Criança , Pré-Escolar , Comorbidade , Busca de Comunicante , Feminino , Florida/epidemiologia , Infecções por HIV/complicações , Infecções por HIV/diagnóstico , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Vigilância da População , Grupos Raciais , Fatores de Risco , Tuberculose/complicações , Tuberculose/diagnóstico
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