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1.
J Evol Biol ; 26(9): 1866-74, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23837400

RESUMO

Habitats are spatially and temporally variable, and organisms must be able to track these changes. One potential mechanism for this is dispersal by flight. Therefore, we would expect flying animals to show adaptations in wing shape related to habitat variation. In this work, we explored variation in wing shape in relation to preferred water body (flowing water or standing water with tolerance for temporary conditions) and landscape (forested to open) using 32 species of dragonflies of the genus Trithemis (80% of the known species). We included a potential source of variation linked to sexual selection: the extent of wing coloration on hindwings. We used geometric morphometric methods for studying wing shape. We also explored the phenotypic correlation of wing shape between the sexes. We found that wing shape showed a phylogenetic structure and therefore also ran phylogenetic independent contrasts. After correcting for the phylogenetic effects, we found (i) no significant effect of water body on wing shape; (ii) male forewings and female hindwings differed with regard to landscape, being progressively broader from forested to open habitats; (iii) hindwings showed a wider base in wings with more coloration, especially in males; and (iv) evidence for phenotypic correlation of wing shape between the sexes across species. Hence, our results suggest that natural and sexual selection are acting partially independently on fore- and hindwings and with differences between the sexes, despite evidence for phenotypic correlation of wing shape between males and females.


Assuntos
Adaptação Biológica/fisiologia , Evolução Biológica , Ecossistema , Odonatos/fisiologia , Pigmentação/fisiologia , Asas de Animais/anatomia & histologia , Análise de Variância , Animais , Feminino , Lagos , Masculino , Países Baixos , Filogenia , Rios , Fatores Sexuais , Especificidade da Espécie , Asas de Animais/fisiologia
2.
Placenta ; 131: 28-35, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36473391

RESUMO

INTRODUCTION: Chronic histiocytic intervillositis (CHI) is a rare histopathological lesion in the placenta that is associated with poor reproductive outcomes. The intervillous infiltrate consists mostly of maternal mononuclear cells and fibrin depositions, which are both indicators for the severity of the intervillous infiltrate. The severity of the intervillous infiltrate as well as the clinical outcomes of pregnancy differ between cases. Our objective is to determine the relation between the severity of the intervillous infiltrate and the clinical outcomes of CHI. METHODS: Cases of CHI were semi-quantitatively graded based on histopathological severity scores. Hereto, CD68 positive mononuclear cells were quantified, fibrin depositions visualized by both a PTAH stain and an immuohistochemical staining, and placental dysfunction was assessed via thrombomodulin staining. RESULTS: This study included 36 women with CHI. A higher CD68 score was significantly associated with a lower birthweight. Loss of placental thrombomodulin was associated with lower gestational age, lower birthweight, and a lower placenta weight. The combined severity score based on CD68 and PTAH was significantly associated with fetal growth restriction, and the joint score of CD68 and fibrin was associated with birthweight and placental weight. DISCUSSION: More severe intervillous infiltrates in CHI placentas is associated with a lower birth weight and placental weight. Furthermore, this study proposes thrombomodulin as a possible new severity marker of placental damage. More research is needed to better understand the pathophysiology of CHI.


Assuntos
Doenças Placentárias , Placenta , Gravidez , Feminino , Humanos , Placenta/patologia , Vilosidades Coriônicas/patologia , Trombomodulina , Idade Gestacional , Peso Fetal , Peso ao Nascer , Doenças Placentárias/patologia , Fibrina
3.
ESMO Open ; 6(3): 100103, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33887686

RESUMO

BACKGROUND: Organoid technology has recently emerged as a powerful tool to assess drug sensitivity of individual patient tumors in vitro. Organoids may therefore represent a new avenue for precision medicine, as this circumvents many of the complexities associated with DNA- or transcriptional-profiling. MATERIALS AND METHODS: The SENSOR trial was a single-arm, single-center, prospective intervention trial to evaluate the feasibility of patient-derived organoids to allocate patients for treatment with off-label or investigational agents. The primary endpoint was an objective response rate of ≥20%. Patients underwent a biopsy for culture before commencing their last round standard of care. Organoids were exposed to a panel of eight drugs and patients were treated after progression on standard-of-care treatment and when a clear signal of antitumor activity was identified in vitro. RESULTS: Sixty-one patients were included and we generated 31 organoids of 54 eligible patients. Twenty-five cultures were subjected to drug screening and 19 organoids exhibited substantial responses to one or more drugs. Three patients underwent treatment with vistusertib and three with capivasertib. Despite drug sensitivity of organoids, patients did not demonstrate objective clinical responses to the recommended treatment. CONCLUSIONS: Organoid technology had limited value as a tool for precision medicine in this patient population because a large fraction of patients could not undergo treatment or because the recommended treatment did not elicit an objective response. We identified several essential parameters, such as the culture success rate, clinical deterioration of patients during standard of care, and rational design of drug panels that need to be accounted for in organoid-guided clinical studies.


Assuntos
Neoplasias Colorretais , Preparações Farmacêuticas , Neoplasias Colorretais/tratamento farmacológico , Humanos , Organoides , Medicina de Precisão , Estudos Prospectivos
4.
J Neural Eng ; 17(2): 022001, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-31986492

RESUMO

The N400 is an event related potential that is evoked in response to conceptually meaningful stimuli. It is for instance more negative in response to incongruent than congruent words in a sentence, and more negative for unrelated than related words following a prime word. This sensitivity to semantic content of a stimulus in relation to the mental context of an individual makes it a signal of interest for Brain Computer Interfaces. A complicating aspect is the number of factors that can affect the N400 amplitude. In this paper, we provide an accessible overview of this range of N400 effects, and survey the three main BCI application areas that currently exploit the N400: (1) exploiting the semantic processing of faces to enhance matrix speller performance, (2) detecting language processing in patients with Disorders of Consciousness, and (3) using semantic stimuli to probe what is on a user's mind. Drawing on studies from these application areas, we illustrate that the N400 can successfully be exploited for BCI purposes, but that the signal-to-noise ratio is a limiting factor, with signal strength also varying strongly across subjects. Furthermore, we put findings in context of the general N400 literature, noting open questions and identifying opportunities for further research.


Assuntos
Interfaces Cérebro-Computador , Encéfalo , Computadores , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Masculino , Tempo de Reação , Semântica
5.
J Reprod Immunol ; 142: 103194, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32979711

RESUMO

Oocyte donation (OD) pregnancies are characterized by a complete immunogenetic dissimilarity between mother and fetus, which requires enhanced immunoregulation compared to naturally conceived (NC) pregnancies. The trophoblast expresses co-inhibitory ligands crucial for regulation of the maternal T cell response. Therefore, we studied the role of placental immune checkpoint inhibitors for the establishment of fetal tolerance and their relation to the development of preeclampsia in OD compared to NC pregnancies. Placental tissue from uncomplicated OD (n = 21) and NC (n = 21) pregnancies, and OD (n = 9) and NC (n = 15) pregnancies complicated with preeclampsia were studied. Protein expression of co-inhibitory ligands PD-L1 and CD200 was double blind semi-quantitatively determined by immunohistochemistry. Messenger RNA expression of PD-L1, CD200 and indoleamine 2,3-dioxygenase (IDO) was determined using qPCR. Decreased PD-L1 and CD200 protein expression and increased IDO mRNA expression was observed in uncomplicated OD versus NC pregnancies (all p < 0.05). CD200 protein expression was positively correlated with PD-L1 expression in all groups, with the number of HLA total mismatches and with HLA class I mismatches in uncomplicated OD cases (all p < 0.05). Preeclamptic cases showed lower PD-L1 protein and CD200 protein and mRNA expression in OD compared to NC pregnancies (all p < 0.05). This study shows that signaling by co-inhibitory PD-L1 and CD200 and by immunosuppressive IDO is altered in the placenta of OD pregnancies, suggesting a contribution to the higher risk for preeclampsia. These insights provide future prospects in unraveling the immune paradox of oocyte pregnancy, which are applicable for better risk management and treatment of uncomplicated and preeclamptic pregnancies.


Assuntos
Antígenos CD/metabolismo , Antígeno B7-H1/metabolismo , Doação de Oócitos/efeitos adversos , Pré-Eclâmpsia/imunologia , Trofoblastos/patologia , Adulto , Estudos de Casos e Controles , Feminino , Feto/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Tolerância Imunológica , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Pessoa de Meia-Idade , Pré-Eclâmpsia/patologia , Gravidez , Linfócitos T/imunologia , Trofoblastos/imunologia , Trofoblastos/metabolismo
6.
Prev Med ; 47(3): 279-83, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18329704

RESUMO

OBJECTIVE: Natural elements in the built healthcare environment have shown to hold potential stress-reducing properties. In order to shed light on the underlying mechanism of stress-reducing effects of nature, the present study investigates whether the stress-reducing effects of indoor plants occur because such an environment is perceived as being more attractive. METHOD: A single-factor between-subjects experimental design (nature: indoor plants vs. no plants) was used in which participants (n=77) were presented with a scenario describing hospitalization with a possible legionella diagnosis. The study was conducted from March to May 2007 in the Netherlands. Subsequently, they were exposed to a photo of a hospital room. In this room were either indoor plants, or there was a painting of an urban environment on the wall. Afterwards, perceived stress and the perceived attractiveness of the hospital room were measured. RESULTS: Participants exposed to the hospital room with indoor plants reported less stress than those in the control condition. Mediation analysis confirmed that indoor plants in a hospital room reduce feelings of stress through the perceived attractiveness of the room. CONCLUSION: This study confirms the stress-reducing properties of natural elements in the built healthcare environment. It also sheds light on the underlying mechanism causing this stress-reduction.


Assuntos
Afeto , Planejamento Ambiental , Quartos de Pacientes , Percepção , Plantas , Estresse Psicológico , Adulto , Saúde Ambiental , Arquitetura de Instituições de Saúde , Feminino , Hospitais , Humanos , Pacientes Internados/psicologia , Decoração de Interiores e Mobiliário , Masculino , Países Baixos , Síndrome do Edifício Doente/prevenção & controle , Estresse Psicológico/terapia , Ventilação
7.
Curr Biol ; 7(4): 239-45, 1997 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9094311

RESUMO

BACKGROUND: Protein disulfide isomerase (PDI), a multifunctional protein of the endoplasmic reticulum, catalyzes the formation, breakage and rearrangement of disulfide bonds during protein folding. Dissection of this protein into its individual domains has confirmed the presence of the a and a' domains, which are homologous to thioredoxin, having related structures and activities. The a and a' domains both contain a -Cys-Gly-His-Cys- active-site sequence motif. The remainder of the molecule consists primarily of two further domains, designated b and b' which are thought to be sequence repeats on the basis of a limited sequence similarity. The functions of the b and b' domains are unknown and, until now, the structure of neither domain was known. RESULTS: Heteronuclear nuclear magnetic resonance (NMR) methods have been used to determine the global fold of the PDI b domain. The protein has an alpha/beta fold with the order of the elements of secondary structure being beta1-alpha1-beta2-alpha2-beta3-alpha3-beta4-beta5+ ++-alpha4. The strands are all in a parallel arrangement with respect to each other, except for beta4 which is antiparallel. The arrangement of the secondary structure elements of the b domain is identical to that found in the a domain of PDI and in the ubiquitous redox protein thioredoxin; the three-dimensional folding topology of the b domain is also very similar to that of these proteins. CONCLUSIONS: Our determination of the global fold of the b domain of PDI by NMR reveals that, like the a domain, the b domain contains the thioredoxin motif, even though the b domain has no significant amino-acid sequence similarities to any members of the thioredoxin family. This observation, together with indications that the b' domain adopts a similar fold, suggests that PDI consists of active and inactive thioredoxin modules. These modules may have been adapted during evolution to provide PDI with its complete spectrum of enzymatic activities.


Assuntos
Isomerases/química , Isomerases/metabolismo , Dobramento de Proteína , Estrutura Secundária de Proteína , Tiorredoxinas/química , Tiorredoxinas/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Simulação por Computador , Humanos , Espectroscopia de Ressonância Magnética , Modelos Estruturais , Dados de Sequência Molecular , Isomerases de Dissulfetos de Proteínas , Software
8.
Ned Tijdschr Geneeskd ; 161: D2381, 2017.
Artigo em Holandês | MEDLINE | ID: mdl-29271322

RESUMO

There are two reasons why general practitioners (GPs) should collaborate with others in their neighbourhood: social problems that translate into physical symptoms and addressing healthy lifestyles and prevention.


Assuntos
Clínicos Gerais , Papel do Médico , Medicina Preventiva/métodos , Comportamento Social , Feminino , Promoção da Saúde/métodos , Estilo de Vida Saudável , Humanos , Masculino , Características de Residência
9.
Biochim Biophys Acta ; 623(2): 461-6, 1980 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-7190440

RESUMO

Proton-NMR resonances of trytophan 3 and tyrosine 69 in bovine pancreatic phospholipase A2, its pro-enzyme and in Ala1-transaminated protein were assigned using photochemically-induced dynamic nuclear polarization (photo-CIDNP) as such or in combination with spin-echo measurements. In addition assignments were made by suppression of cross-relaxation effects using short (0.1 s) high-power laser pulses.


Assuntos
Pâncreas/enzimologia , Fosfolipases A , Fosfolipases , Animais , Bovinos , Lasers , Espectroscopia de Ressonância Magnética , Micelas , Física Nuclear , Fosfolipases A2 , Conformação Proteica , Triptofano/análise , Tirosina/análise
10.
J Mol Biol ; 308(5): 993-1009, 2001 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-11352587

RESUMO

The determination by NMR of the solution structure of the phosphorylated enzyme IIB (P-IIB(Chb)) of the N,N'-diacetylchitobiose-specific phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli is presented. Most of the backbone and side-chain resonances were assigned using a variety of mostly heteronuclear NMR experiments. The remaining resonances were assigned with the help of the structure calculations.NOE-derived distance restraints were used in distance geometry calculations followed by molecular dynamics and simulated annealing protocols. In addition, combinations of ambiguous restraints were used to resolve ambiguities in the NOE assignments. By combining sets of ambiguous and unambiguous restraints into new ambiguous restraints, an error function was constructed that was less sensitive to information loss caused by assignment uncertainties. The final set of structures had a pairwise rmsd of 0.59 A and 1.16 A for the heavy atoms of the backbone and side-chains, respectively. Comparing the P-IIB(Chb) solution structure with the previously determined NMR and X-ray structures of the wild-type and the Cys10Ser mutant shows that significant differences between the structures are limited to the active-site region. The phosphoryl group at the active-site cysteine residue is surrounded by a loop formed by residues 10 through 16. NOE and chemical shift data suggest that the phosphoryl group makes hydrogen bonds with the backbone amide protons of residues 12 and 15. The binding mode of the phosphoryl group is very similar to that of the protein tyrosine phosphatases. The differences observed are in accordance with the presumption that IIB(Chb) has to be more resistant to hydrolysis than the protein tyrosine phosphatases. We propose a proton relay network by which a transfer occurs between the cysteine SH proton and the solvent via the hydroxyl group of Thr16.


Assuntos
Cisteína/metabolismo , Dissacarídeos/metabolismo , Escherichia coli/enzimologia , Ressonância Magnética Nuclear Biomolecular , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/química , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Mutação , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/genética , Fosforilação , Estrutura Secundária de Proteína , Prótons , Solventes , Especificidade por Substrato , Termodinâmica
11.
Artigo em Inglês | MEDLINE | ID: mdl-26949710

RESUMO

People affected by severe neuro-degenerative diseases (e.g., late-stage amyotrophic lateral sclerosis (ALS) or locked-in syndrome) eventually lose all muscular control. Thus, they cannot use traditional assistive communication devices that depend on muscle control, or brain-computer interfaces (BCIs) that depend on the ability to control gaze. While auditory and tactile BCIs can provide communication to such individuals, their use typically entails an artificial mapping between the stimulus and the communication intent. This makes these BCIs difficult to learn and use. In this study, we investigated the use of selective auditory attention to natural speech as an avenue for BCI communication. In this approach, the user communicates by directing his/her attention to one of two simultaneously presented speakers. We used electrocorticographic (ECoG) signals in the gamma band (70-170 Hz) to infer the identity of attended speaker, thereby removing the need to learn such an artificial mapping. Our results from twelve human subjects show that a single cortical location over superior temporal gyrus or pre-motor cortex is typically sufficient to identify the attended speaker within 10 s and with 77% accuracy (50% accuracy due to chance). These results lay the groundwork for future studies that may determine the real-time performance of BCIs based on selective auditory attention to speech.

12.
Protein Sci ; 2(8): 1331-41, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8401218

RESUMO

This report presents the backbone assignments and the secondary structure determination of the A domain of the Escherichia coli mannitol transport protein, enzyme-IImtl. The backbone resonances were partially assigned using three-dimensional heteronuclear 1H NOE 1H-15N single-quantum coherence (15N NOESY-HSQC) spectroscopy and three-dimensional heteronuclear 1H total correlation 1H-15N single-quantum coherence (15N TOCSY-HSQC) spectroscopy on uniformly 15N enriched protein. Triple-resonance experiments on uniformly 15N/13C enriched protein were necessary to complete the backbone assignments, due to overlapping 1H and 15N frequencies. Data obtained from three-dimensional 1H-15N-13C alpha correlation experiments (HNCA and HN(CO)CA), a three-dimensional 1H-15N-13CO correlation experiment (HNCO), and a three-dimensional 1H alpha-13C alpha-13CO correlation experiment (COCAH) were combined using SNARF software, and yielded the assignments of virtually all observed backbone resonances. Determination of the secondary structure of IIAmtl is based upon NOE information from the 15N NOESY-HSQC and the 1H alpha and 13C alpha secondary chemical shifts. The resulting secondary structure is considerably different from that reported for IIAglc of E. coli and Bacillus subtilis determined by NMR and X-ray.


Assuntos
Escherichia coli/enzimologia , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/química , Conformação Proteica , Estrutura Secundária de Proteína , Sequência de Aminoácidos , Bacillus subtilis/enzimologia , Enterobacter/enzimologia , Proteínas de Escherichia coli , Espectroscopia de Ressonância Magnética/métodos , Dados de Sequência Molecular , Proteínas de Transporte de Monossacarídeos , Salmonella typhimurium/enzimologia , Homologia de Sequência de Aminoácidos , Difração de Raios X
13.
Protein Sci ; 4(12): 2587-93, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8580850

RESUMO

A genetically engineered protein consisting of the 120 residues at the N-terminus of human protein disulfide isomerase (PDI) has been characterized by 1H, 13C, and 15N NMR methods. The sequence of this protein is 35% identical to Escherichia coli thioredoxin, and it has been found also to have similar patterns of secondary structure and beta-sheet topology. The results confirm that PDI is a modular, multidomain protein. The last 20 residues of the N-terminal domain of PDI are some of those that are similar to part of the estrogen receptor, yet they appear to be an intrinsic part of the thioredoxin fold. This observation makes it unlikely that any of the segments of PDI with similarities to the estrogen receptor comprise individual domains.


Assuntos
Isomerases/química , Espectroscopia de Ressonância Magnética , Tiorredoxinas/química , Sequência de Aminoácidos , Escherichia coli/química , Humanos , Dados de Sequência Molecular , Isomerases de Dissulfetos de Proteínas , Estrutura Secundária de Proteína , Receptores de Estrogênio/química , Homologia de Sequência
14.
Protein Sci ; 6(2): 304-14, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9041631

RESUMO

The assignment of the side-chain NMR resonances and the determination of the three-dimensional solution structure of the C10S mutant of enzyme IIBcellobiose (IIBcel) of the phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli are presented. The side-chain resonances were assigned nearly completely using a variety of mostly heteronuclear NMR experiments, including HCCH-TOCSY, HCCH-COSY, and COCCH-TOCSY experiments as well as CBCACOHA, CBCA(CO)NH, and HBHA(CBCA)(CO)NH experiments. In order to obtain the three-dimensional structure, NOE data were collected from 15N-NOESY-HSQC, 13C-HSQC-NOESY, and 2D NOE experiments. The distance restraints derived from these NOE data were used in distance geometry calculations followed by molecular dynamics and simulated annealing protocols. In an iterative procedure, additional NOE assignments were derived from the calculated structures and new structures were calculated. The final set of structures, calculated with approximately 2000 unambiguous and ambiguous distance restraints, has an rms deviation of 1.1 A on C alpha atoms. IIBcel consists of a four stranded parallel beta-sheet, in the order 2134. The sheet is flanked with two and three alpha-helices on either side. Residue 10, a cysteine in the wild-type enzyme, which is phosphorylated during the catalytic cycle, is located at the end of the first beta-strand. A loop that is proposed to be involved in the binding of the phosphoryl-group follows the cysteine. The loop appears to be disordered in the unphosphorylated state.


Assuntos
Escherichia coli/enzimologia , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/química , Sequência de Aminoácidos , Isótopos de Carbono , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Isótopos de Nitrogênio , Prótons , Soluções
15.
Protein Sci ; 8(1): 5-12, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10210178

RESUMO

The transmembrane glycoprotein gp130 is the common signal transducing receptor subunit of the interleukin-6-type cytokines. It is a member of the cytokine-receptor superfamily predicted to consist of six domains in its extracellular part. The second and third domain constitute the cytokine-binding module defined by a set of four conserved cysteines and a WSXWS motif, respectively. The three-dimensional structure of the carboxy-terminal domain of this region was determined by multidimensional NMR. The domain consists of seven beta-strands constituting a fibronectin type III-like topology. The structure reveals that the WSDWS motif of gp130 is part of an extended tryptophan/arginine zipper which modulates the conformation of the CD loop.


Assuntos
Antígenos CD/química , Glicoproteínas de Membrana/química , Receptores de Citocinas/química , Sequência de Aminoácidos , Receptor gp130 de Citocina , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Homologia de Sequência de Aminoácidos
16.
Protein Sci ; 3(2): 282-90, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8003964

RESUMO

The assignment of backbone resonances and the secondary structure determination of the Cys 10 Ser mutant of enzyme IIBcellobiose of the Escherichia coli cellobiose-specific phosphoenol-pyruvate-dependent phosphotransferase system are presented. The backbone resonances were assigned using 4 triple resonance experiments, the HNCA and HN(CO)CA experiments, correlating backbone 1H, 15N, and 13C alpha resonances, and the HN(CA)CO and HNCO experiments, correlating backbone 1H,15N and 13CO resonances. Heteronuclear 1H-NOE 1H-15N single quantum coherence (15N-NOESY-HSQC) spectroscopy and heteronuclear 1H total correlation 1H-15N single quantum coherence (15N-TOCSY-HSQC) spectroscopy were used to resolve ambiguities arising from overlapping 13C alpha and 13CO frequencies and to check the assignments from the triple resonance experiments. This procedure, together with a 3-dimensional 1H alpha-13C alpha-13CO experiment (COCAH), yielded the assignment for all observed backbone resonances. The secondary structure was determined using information both from the deviation of observed 1H alpha and 13C alpha chemical shifts from their random coil values and 1H-NOE information from the 15N-NOESY-HSQC. These data show that enzyme IIBcellobiose consists of a 4-stranded parallel beta-sheet and 5 alpha-helices. In the wild-type enzyme IIBcellobiose, the catalytic residue appears to be located at the end of a beta-strand.


Assuntos
Escherichia coli/enzimologia , Espectroscopia de Ressonância Magnética , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/química , Sequência de Aminoácidos , Sequência de Bases , Dados de Sequência Molecular , Mutagênese , Estrutura Secundária de Proteína
17.
FEBS Lett ; 315(1): 11-5, 1993 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-8416803

RESUMO

The region of the surface of the histidine-containing protein (HPr) which interacts with the A domain of the mannitol-specific Enzyme II (II(Amt1)) has been mapped by titrating the A-domain into a solution of 15N-labeled HPr and monitoring the effects on the amide proton and nitrogen chemical shifts via heteronuclear single quantum correlation spectroscopy (HSQC). Fourteen of the eighty-five HPr amino acid residues show large changes in either the 15N or 1H chemical shifts or both as a result of the presence of II(Amt1) while a further seventeen residues experience lesser shifts. Most of the residues involved are surface residues accounting for approximately 25% of the surface of HPr. Phosphorylation of HPr with catalytic amounts of Enzyme I (EI), in the absence of II(Amt1) resulted in chemical shift changes in a sub-set of the above residues; these were located more in the vicinity of the active site phospho-histidine. Phosphorylation of the HPr/II(Amt1) complex resulted in a HSQC spectrum which was indistinguishable from the P-HPr spectrum in the absence of II(Amt1) indicating that, as expected, the complex P-HPr/P-II(Amt1) does not exist even at the high concentrations necessary for NMR.


Assuntos
Escherichia coli/metabolismo , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/metabolismo , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Substâncias Macromoleculares , Espectroscopia de Ressonância Magnética , Fosforilação , Estrutura Terciária de Proteína
18.
Obstet Gynecol ; 96(3): 346-50, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10960624

RESUMO

OBJECTIVE: To determine whether the degree of cervical lengthening after cerclage and whether serial follow-up measurements of cervical length after cerclage are predictive of pregnancy outcome. METHODS: Eighty women whose primary physician determined that a prophylactic (n = 50) or urgent cerclage (n = 30) was indicated had transvaginal ultrasonographic evaluation before and after cerclage. Thereafter, most women had three additional transvaginal ultrasound examinations until 32 weeks' gestation. At each examination, the mean of three measurements was calculated. Statistical analyses were done by t test, analysis of variance, and logistic regression, with significance set at P <.05. RESULTS: The mean +/- standard deviation precerclage cervical length was 27.2 +/- 10.3 mm and after cerclage was 34.1 +/- 9.9 mm (n = 80, P <.001, paired t test). No significant association was found (r = -0.26) between the difference in cervical length (postcerclage - precerclage lengths) and pregnancy outcome. Patients with a prophylactic cerclage had a mean cervical length that was consistently longer in patients delivering at term compared with those who delivered preterm at 20 to 32 weeks' gestation. In the urgent cerclage group a significant difference in cervical length between those who delivered at term compared with preterm was evident only at 28 to 32 weeks. CONCLUSION: The increase in cervical length after cerclage is not predictive of term delivery. Serial cervical length measurements in the late second or early third trimester predict preterm birth but could provide earlier warning in patients with a prophylactic cerclage than in patients with urgent cerclage.


Assuntos
Colo do Útero/diagnóstico por imagem , Endossonografia , Trabalho de Parto Prematuro/diagnóstico por imagem , Ultrassonografia Pré-Natal , Incompetência do Colo do Útero/cirurgia , Adulto , Feminino , Seguimentos , Idade Gestacional , Humanos , Recém-Nascido , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Gravidez , Prognóstico , Estudos Prospectivos , Técnicas de Sutura , Incompetência do Colo do Útero/diagnóstico por imagem
19.
Early Hum Dev ; 30(1): 33-40, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1396288

RESUMO

Using Doppler ultrasound, previous studies revealed a considerable increase in vascular resistance in the uteroplacental circulation during Braxton Hicks' contractions. Consequently, uteroplacental blood flow is reduced and this affects placental oxygen transfer to the fetus, causing a fall in fetal arterial PO2. In view of the important role of arterial PO2 in the regulation of cerebral blood flow in the fetus, we hypothesised that Braxton Hicks' contractions cause a decrease in cerebral vascular resistance. A study was undertaken in 16 healthy near term pregnancies, using pulsed-wave Doppler ultrasound to evaluate the influence of Braxton Hicks' contractions on cerebral vascular resistance of the fetus. Flow velocity waveforms (FVWs) were recorded of the fetal internal carotid and umbilical artery and the Pulsatility Index (PI) was calculated. During Braxton Hicks' contractions the PI in the recorded vessels did not change. Fetal heart rate showed also no changes during Braxton Hicks' contractions. These findings indicate that resistance to blood flow downstream of these arteries, is not significantly altered, suggesting that Braxton Hicks' contractions have little or no effect on fetal haemodynamics and on fetal oxygenation in the healthy near term fetus.


Assuntos
Artéria Carótida Interna/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Reologia/métodos , Ultrassonografia Pré-Natal/métodos , Artérias Umbilicais/diagnóstico por imagem , Contração Uterina/fisiologia , Artéria Carótida Interna/embriologia , Feminino , Feto/fisiologia , Humanos , Gravidez , Artérias Umbilicais/embriologia
20.
Gerontologist ; 41(4): 449-60, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11490043

RESUMO

PURPOSE: We examined the effects of communication skills training and the use of memory books by certified nursing assistants (CNAs) on verbal interactions between CNAs (n = 64) and nursing home residents (n = 67) during care routines. DESIGN AND METHODS: CNAs were taught to use communication skills and memory books during their interactions with residents with moderate cognitive impairments and intact communication abilities. A staff motivational system was used to encourage performance and maintenance of these skills. Formal measures of treatment implementation were included. RESULTS: Results were compared with those for participants on no-treatment control units. Trained CNAs talked more, used positive statements more frequently, and tended to increase the number of specific instructions given to residents. Changes in staff behavior did not result in an increase in total time giving care to residents. Maintenance of CNA behavior change was found 2 months after research staff exited the facility. Although an increase was found in positive verbal interactions between CNAs and residents on intervention units, other changes in resident communication were absent. IMPLICATIONS: Nursing staff can be trained to improve and maintain communication skills during care without increasing the amount of time delivering care. The methodological advantages of including measures to assess treatment implementation are discussed.


Assuntos
Doença de Alzheimer/enfermagem , Comunicação , Instituição de Longa Permanência para Idosos , Relações Enfermeiro-Paciente , Casas de Saúde , Recursos Humanos de Enfermagem/psicologia , Atividades Cotidianas/psicologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/psicologia , Feminino , Seguimentos , Avaliação Geriátrica , Humanos , Capacitação em Serviço , Masculino , Pessoa de Meia-Idade , Motivação , Avaliação de Processos e Resultados em Cuidados de Saúde , Sistemas de Alerta
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