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1.
J Neonatal Perinatal Med ; 17(4): 565-573, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38788097

RESUMO

BACKGROUND: Several reports demonstrated that perinatal SARS-CoV-2 has significant impact on maternal and neonatal health outcomes. However, the relationship between severity of maternal illness with outcomes remains less clear. METHODS: This is a single-center retrospective cohort study of mother/infant dyads with positive maternal test for SARS-CoV-2 between 14 days prior and 3 days after delivery from 3/30/2020 to 12/28/2021. RESULTS: Among 538 mothers, those with moderate/severe/critical illness were more likely to undergo induction, receive oxygen, mechanical ventilation or ECMO. Mortality was significantly higher among the mothers with severe illness than asymptomatic and those with mild illness (6% vs 0% and 0%, respectively, P < 0.05). Neonates born to mothers with moderate/severe/critical illness were more likely to be preterm with lower birth weight, and to be admitted to the NICU (P < 0.05) but not to be small for gestational age. Mild maternal illness was only associated with NICU admission for isolation precaution and decreased rate of breastfeeding. CONCLUSIONS: Maternal illness severity was significantly associated with prematurity and several adverse maternal and neonatal outcomes.


Assuntos
COVID-19 , Complicações Infecciosas na Gravidez , Índice de Gravidade de Doença , Humanos , COVID-19/mortalidade , Feminino , Gravidez , Recém-Nascido , Estudos Retrospectivos , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , SARS-CoV-2 , Resultado da Gravidez/epidemiologia , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Masculino , Respiração Artificial/estatística & dados numéricos , Transmissão Vertical de Doenças Infecciosas/estatística & dados numéricos
2.
J Neonatal Perinatal Med ; 14(3): 411-417, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33459671

RESUMO

BACKGROUND: PICC line use is a common practice in neonatal units, but it is associated with various complications. Catheter migration is the most common complication in neonates. Periodic imaging is recommended to monitor the tip position of the PICCs, but the optimal frequency is undetermined. The incidence, timing and risk factors that are associated with PICC migration have not been fully investigated beyond 24 hrs in neonates. The aim of the study was to determine the incidence, timing and risk factors that are associated with peripherally inserted central venous catheter (PICC) migration in neonates. METHODS: This was a single center, retrospective study of 168 PICCs placed in 141 neonates in the neonatal intensive care unit (NICU) between 2015 and 2016. The incidence of catheter migration was determined radiographically at 12-24 hrs and every third day after insertion until it was removed. RESULTS: Overall incidence of PICC migration was 28%and most commonly was detected within the first three days after PICC placement (83%). The incidence of PICC migration was higher in males. The PICC migration was associated with difficulty advancing the PICC at the time of insertion and PICC dressing change. CONCLUSION: Serial evaluation of PICC placement in neonates is required to maintain proper position. Based on our experience in our unit, we recommend periodic imaging at 12-24 hrs and on the third day after PICC placement as most migration occurred within three days after insertion.


Assuntos
Infecções Relacionadas a Cateter , Cateterismo Venoso Central , Cateterismo Periférico , Cateterismo Venoso Central/efeitos adversos , Cateterismo Periférico/efeitos adversos , Feminino , Humanos , Incidência , Recém-Nascido , Masculino , Estudos Retrospectivos , Fatores de Risco
3.
J Perinatol ; 37(9): 1043-1046, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28617427

RESUMO

OBJECTIVE: To assess whether mortality in patients with evolving bronchopulmonary dysplasia (BPD, defined as ⩾28 days of oxygen exposure with lung disease) is independently associated with pulmonary arterial hypertension (PAH) and surgery. STUDY DESIGN: Single institution retrospective birth cohort of preterm infants with gestational age (GA) 230/7 to 366/7 weeks, and evolving BPD delivered between 2001 and 2014. Surgery was classified as minor or major using published criteria. Mortality was analyzed by stepwise logistic regression analysis. RESULTS: Among 577 patients with evolving BPD, 33 (6%) died prior to discharge. Mortality decreased with GA (adjusted odds ratio (aOR): 0.69; 95% confidence interval (CI): 0.55, 0.87), birth weight Z-score (aOR: 0.69, 95% CI: 0.47, 0.996) and increased with PAH (aOR: 30, 95% CI: 2.1, 415), major surgery (aOR; 2.8, 95% CI: 1.3, 6.3), and PAH and surgery (aOR: 10.3, 95% CI: 2.5, 42.1). CONCLUSION: Among preterm patients with evolving BPD, PAH and surgery are independently associated with mortality.


Assuntos
Displasia Broncopulmonar/mortalidade , Hipertensão Pulmonar/mortalidade , Displasia Broncopulmonar/cirurgia , Estudos de Casos e Controles , Eletrocardiografia , Feminino , Idade Gestacional , Humanos , Hipertensão Pulmonar/diagnóstico , Lactente , Lactente Extremamente Prematuro , Recém-Nascido , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Modelos Logísticos , Masculino , Estudos Retrospectivos , Fatores de Risco
4.
J Perinatol ; 37(4): 441-447, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27977011

RESUMO

OBJECTIVE: The objective of the study was to determine whether withdrawal of support in severe 'intraventricular hemorrhage' (IVH), that is, IVH grade 3 and periventricular hemorrhagic infarction (PVHI), has decreased after publication of studies that show improved prognosis and to examine cranial ultrasonograms, including PVHI territories defined by Bassan. STUDY DESIGN: Retrospective cohort of preterm infants from 23 0/7 to 28 6/7 weeks' gestation in 1993 to 2013. RESULTS: Among the 1755 infants, 1494 had no bleed, germinal matrix hemorrhage (GMH) or IVH grade 2, 137 had grade 3 IVH and 124 had PVHI. The odds of withdrawal of support, adjusted for severity of GMH-IVH and baseline variables, did not decrease after publications showing better prognosis. Among 82 patients who died with PVHI, 76 had life support withdrawn, including 34 without another contributing cause of death. The median number of PVHI territories involved was three. CONCLUSION: Withdrawal of support adjusted for severity of GMH-IVH did not significantly change after publications showing better prognosis.


Assuntos
Hemorragia Cerebral/mortalidade , Hemorragia Cerebral/terapia , Lactente Extremamente Prematuro , Cuidados para Prolongar a Vida , Suspensão de Tratamento/estatística & dados numéricos , Hemorragia Cerebral/diagnóstico por imagem , Bases de Dados Factuais , Ecoencefalografia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Modelos Logísticos , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Texas/epidemiologia
6.
Biochemistry (Mosc) ; 66(11): 1249-55, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11743869

RESUMO

A large share of the current ideas about the mechanism of proton transport by bacteriorhodopsin has emerged from studies of site-specific mutants. This review is an attempt to check some of these ideas against the natural variability in the primary structure of the protein.


Assuntos
Bacteriorodopsinas/metabolismo , Sequência de Aminoácidos , Bacteriorodopsinas/química , Bacteriorodopsinas/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Prótons , Homologia de Sequência de Aminoácidos
7.
Addiction ; 96(9): 1297-305, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11672494

RESUMO

AIMS: This study evaluated the hypothesis that the subjective interviewer severity rating (ISR) summary indices of the intake Addiction Severity Index (ASI) of less trained interviewers are less valid than those of more highly trained interviewers. DESIGN: Baseline ASIs from three completed studies whose interviewers varied in degree of initial ASI training and subsequent quality assurance monitoring were examined. Associations between baseline ISRs and three other sets of ASI summary indices not based on interviewer ratings-composite scores, clinical indices and evaluation indices-were compared for three groups of interviewers with varying amounts of training. The assumption underlying these analyses was that more reliable ISRs, found in more trained interviewers, would be more highly associated with the other more objective indices. SETTING: Methadone maintenance patients in the Philadelphia and New York City areas. PARTICIPANTS: Thirty-five interviewers with the most intense training who administered 295 interviews; 10 interviewers with an intermediate level of training who administered 763 interviews; and eight identified (and other unidentified) least trained interviewers who administered a total of 276 interviews. Measurements and methods. Four sets of summary indices from the above ASIs. Both bivariate and multivariate analyses were performed. FINDINGS: The study found that the validity of the validity of ISRs was greater in more trained interviewers. CONCLUSIONS: Greater training and subsequent monitoring of ASI interviewers generally appears to be associated with increased ISR validity.


Assuntos
Entrevistas como Assunto/normas , Competência Profissional , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Adulto , Feminino , Pessoal de Saúde/educação , Humanos , Masculino , Metadona/uso terapêutico , Pennsylvania , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
8.
Biochemistry ; 40(38): 11308-17, 2001 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-11560478

RESUMO

In the N to O reaction of the bacteriorhodopsin photocycle, Asp-96 is protonated from the cytoplasmic surface, and coupled to this, the retinal isomerizes from 13-cis,15-anti back to the initial all-trans configuration. To dissect the two steps, and to better understand how and why they occur, we describe the properties of two groups of site-specific mutants in which the N intermediate has greatly increased lifetime. In the first group, with the mutations near the retinal, an unusual N state is produced in which the retinal is 13-cis,15-anti but Asp-96 has a protonated carboxyl group. The apparent pK(a) for the protonation is 7.5, as in the wild-type. It is likely that here the interference with N decay is the result of steric conflict of side-chains with the retinal or with the side-chain of Lys-216 connected to the retinal, which delays the reisomerization after protonation of Asp-96. In the second group, with the mutations located near Asp-96 or between Asp-96 and the cytoplasmic surface, reprotonation of Asp-96 is strongly perturbed. The reisomerization of the retinal occurs only after recovery from a long-living protein conformation in which reprotonation of Asp-96 is either entirely blocked or blocked at low pH.


Assuntos
Ácido Aspártico , Bacteriorodopsinas/química , Bacteriorodopsinas/metabolismo , Halobacterium salinarum/metabolismo , Retinaldeído/química , Retinaldeído/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Bacteriorodopsinas/efeitos da radiação , Sítios de Ligação , Cristalografia por Raios X , Concentração de Íons de Hidrogênio , Cinética , Luz , Modelos Moleculares , Conformação Molecular , Mutagênese Sítio-Dirigida , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo
9.
J Biol Chem ; 276(35): 32495-505, 2001 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-11435422

RESUMO

It was recently found that NOP-1, a membrane protein of Neurospora crassa, shows homology to haloarchaeal rhodopsins and binds retinal after heterologous expression in Pichia pastoris. We report on spectroscopic properties of the Neurospora rhodopsin (NR). The photocycle was studied with flash photolysis and time-resolved Fourier-transform infrared spectroscopy in the pH range 5-8. Proton release and uptake during the photocycle were monitored with the pH-sensitive dye, pyranine. Kinetic and spectral analysis revealed six distinct states in the NR photocycle, and we describe their spectral properties and pH-dependent kinetics in the visible and infrared ranges. The phenotypes of the mutant NR proteins, D131E and E142Q, in which the homologues of the key carboxylic acids of the light-driven proton pump bacteriorhodopsin, Asp-85 and Asp-96, were replaced, show that Glu-142 is not involved in reprotonation of the Schiff base but Asp-131 may be. This implies that, if the NR photocycle is associated with proton transport, it has a low efficiency, similar to that of haloarchaeal sensory rhodopsin II. Fourier-transform Raman spectroscopy revealed unexpected differences between NR and bacteriorhodopsin in the configuration of the retinal chromophore, which may contribute to the less effective reprotonation switch of NR.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas Fúngicas , Neurospora crassa/metabolismo , Rodopsina/metabolismo , Substituição de Aminoácidos , Bacteriorodopsinas/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/genética , Halobacterium salinarum/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Luz , Mutagênese Sítio-Dirigida , Neurospora crassa/genética , Neurospora crassa/efeitos da radiação , Fenótipo , Fotoquímica , Fotólise , Pichia/metabolismo , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Rodopsina/química , Rodopsina/genética , Deleção de Sequência , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier
10.
J Clin Psychol ; 57(8): 1005-12, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11449383

RESUMO

The concept of countertransference has been seen as problematic by feminist therapists. However, feminist therapy theory is intensely interested in the symbolic levels of the relationships between therapists and clients, with an emphasis on how the here and now social context informs and transforms those symbols. This article describes a feminist perspective on the therapist's symbolic relationships to clients, and the positive and challenging ramifications of those symbolic encounters.


Assuntos
Contratransferência , Emoções , Feminismo , Psicoterapia/métodos , Adulto , Ira , Feminino , Humanos , Teoria Psicológica , Simbolismo
11.
J Mol Biol ; 304(5): 715-21, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11124021

RESUMO

Spin labeling EPR spectroscopy has been used to characterize light-induced conformational changes of bacteriorhodopsin (bR). Pairs of nitroxide spin labels were attached to engineered cysteine residues at strategic positions near the cytoplasmic ends of transmembrane alpha-helices B, F, and G in order to monitor distance changes upon light activation. The EPR analysis of six doubly labeled bR mutants indicates that the cytoplasmic end of helix F not only tilts outwards, but also rotates counter-clockwise during the photocycle. The direction of the rotation of helix F is the opposite of the clockwise rotation previously reported for bovine rhodopsin. The opposite chirality of the F helix rotation in the two systems is perhaps related to the differences in the cis-trans photoisomerization of the retinal in the two proteins. Using time-resolved EPR, we monitored the rotation of helix F also in real time, and found that the signal from the rotation arises concurrently with the reprotonation of the retinal Schiff base.


Assuntos
Bacteriorodopsinas/química , Bacteriorodopsinas/efeitos da radiação , Proteínas de Escherichia coli , Luz , Rotação , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Bacteriorodopsinas/genética , Bovinos , Células Quimiorreceptoras , Cisteína/genética , Cisteína/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Cinética , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Modelos Moleculares , Estrutura Secundária de Proteína , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo , Rodopsina/química , Rodopsina/metabolismo , Marcadores de Spin , Temperatura
12.
Biochim Biophys Acta ; 1460(1): 49-59, 2000 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-10984590

RESUMO

As a result of the number of new high-resolution structures of the pigment and some of its photointermediates, a realistic model for the functioning of bacteriorhodopsin seems to be finally emerging. However, lack of structural information for some of the key functional states, and contradictions between some published structural models, argue for the use of the synthetic approach, one that includes use of data from both crystallographic and mutagenesis studies. The role of mutagenesis in this synthetic approach falls into two categories. First, to provide additional structural information, and second, to test the predictions of structural models by studying mutant phenotypes. This review urges critical comparisons of the structural and mutagenesis data, as there are problems with their selective and indiscriminate use.


Assuntos
Bacteriorodopsinas/química , Bombas de Próton/química , Bacteriorodopsinas/genética , Cristalografia , Modelos Químicos , Mutagênese Sítio-Dirigida , Fenótipo , Relação Estrutura-Atividade , Difração de Raios X
13.
Biochemistry ; 39(5): 938-45, 2000 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-10653637

RESUMO

Deuterium kinetic isotope effects (KIE) were measured, and proton inventory plots were constructed, for the rates of reactions in the photocycles of wild-type bacteriorhodopsin and several site-specific mutants. Consistent with earlier reports from many groups, very large KIEs were observed for the third (and largest) rise component for the M state and for the decay of the O state, processes both linked to proton transfers in the extracellular region. The proton inventory plots (ratio of reaction rates in mixtures of H(2)O and D(2)O to that in H(2)O vs mole fraction of D(2)O) were approximately linear for the first and second M rise components and for M decay, as well as for O decay, indicating that the rates of these reactions are limited by simple proton transfer. Uniquely, the third rise component of M (and in the D96N mutant also a fourth rise component) exhibited a strongly curved proton inventory plot, suggesting that its rate, which largely accounts for the rate of deprotonation of the retinal Schiff base, depends on a complex multiproton process. This curvature is observed also in the E194Q, E204Q, and Y57F mutants but not in the R82A mutant. From these findings, and from the locations of bound water in the extracellular region in the crystal structure of the protein [Luecke, Schobert, Richter, Cartailler, and Lanyi (1999) J. Mol. Biol. 291, 899-911], we suspect that the effects of deuterium substitution on the formation of the M state originate from cooperative rearrangements of the extensively hydrogen-bonded water molecules 401, 402, and 406 near Asp-85 and Arg-82.


Assuntos
Bacteriorodopsinas/química , Óxido de Deutério/química , Prótons , Arginina/genética , Ácido Aspártico/genética , Bacteriorodopsinas/genética , Ácido Glutâmico/genética , Halobacterium salinarum/química , Halobacterium salinarum/genética , Cinética , Mutagênese Sítio-Dirigida , Fotólise , Membrana Purpúrea/química , Tirosina/genética , Água/química
15.
Biochemistry ; 38(31): 10070-8, 1999 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-10433714

RESUMO

We measured time-resolved difference spectra, in the visible and the infrared, for the Glu-194 and Glu-204 mutants of bacteriorhodopsin and detected an anomalous O state, labeled O', in addition to the authentic O intermediate, before recovery of the initial state in the photocycle. The O' intermediate exhibits prominent bands at 1712 cm(-1) (positive) and 1387 cm(-1) (negative). These bands arise with the same time constant as the deprotonation of Asp-85. Both bands are shifted to lower frequency upon labeling of the protein with [4-(13)C]aspartic acid. The former band, but not the latter, is shifted in D2O. These shifts identify the two bands as the carboxyl stretch of a protonated aspartic acid and the symmetric carbonyl stretch of an unprotonated aspartate, respectively, and suggest that in O' an initially anionic aspartate enters into protonation equilibrium with Asp-85. Elimination of the few other candidates, on various grounds, identifies Asp-212 as the unknown residue. It is possible, therefore, that in the last step of the photocycle of the mutants studied the proton released from Asp-85 is conducted to the extracellular surface via Asp-212. An earlier report of a weak band at 1712 cm(-1) late in the wild-type photocycle [Zscherp and Heberle (1997) J. Phys. Chem. B 101, 10542-10547] suggests that Asp-212 might play this role in the wild-type protein also.


Assuntos
Ácido Aspártico/química , Bacteriorodopsinas/química , Prótons , Ácido Aspártico/metabolismo , Bacteriorodopsinas/genética , Bacteriorodopsinas/metabolismo , Ácido Glutâmico/genética , Glutamina/genética , Halobacterium salinarum , Cinética , Fotólise , Fotoperíodo , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo
16.
Biophys J ; 76(6): 3219-26, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10354446

RESUMO

Adding Ca2+ or other cations to deionized bacteriorhodopsin causes a blue to purple color shift, a result of deprotonation of Asp85. It has been proposed by different groups that the protonation state of Asp85 responds to the binding of Ca2+ either 1) directly at a specific site in the protein or 2) indirectly through the rise of the surface pH. We tested the idea of specific binding of Ca2+ and found that the surface pH, as determined from the ionization state of eosin covalently linked to engineered cysteine residues, rises about equally at both extracellular and cytoplasmic surfaces when only one Ca2+ is added. This precludes binding to a specific site and suggests that rather than decreasing the pKa of Asp85 by direct interaction, Ca2+ increases the surface pH by binding to anionic lipid groups. As Ca2+ is added the surface pH rises, but deprotonation of Asp85 occurs only when the surface pH approaches its pKa. The nonlinear relationship between Ca2+ binding and deprotonation of Asp85 from this effect is different in the wild-type protein and in various mutants and explains the observed complex and varied spectral titration curves.


Assuntos
Bacteriorodopsinas/química , Bacteriorodopsinas/metabolismo , Cálcio/metabolismo , Ácido Aspártico/química , Bacteriorodopsinas/genética , Sítios de Ligação , Fenômenos Biofísicos , Biofísica , Calorimetria , Cisteína/química , Halobacterium salinarum/genética , Halobacterium salinarum/metabolismo , Concentração de Íons de Hidrogênio , Mutação , Ligação Proteica , Prótons , Propriedades de Superfície
17.
Biochemistry ; 38(21): 6855-61, 1999 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-10346907

RESUMO

The functions of the four aspartic acid residues in interhelical loops at the cytoplasmic surface of bacteriorhodopsin, Asp-36, Asp-38, Asp-102, and Asp-104, were investigated by studying single and multiple aspartic acid to asparagine mutants. The same mutants were examined also with the additional D96N residue replacement. The kinetics of the M and N intermediates of the photochemical cycles of these recombinant proteins were affected only in a minor, although self-consistent, way. When residue 38 is an aspartate and anionic, it makes the internal proton exchange between the retinal Schiff base and Asp-96 about 3 times more rapid, and events associated with the reisomerization of retinal to all-trans about 3 times slower. Asp-36 has the opposite effect on these processes, but to a smaller extent. Asp-102 and Asp-104 have even less or none of these effects. Of the four aspartates, only Asp-36 could play a direct role in proton uptake at the cytoplasmic surface. In the 13 bacterioopsin sequences now available, only this surface aspartate is conserved.


Assuntos
Ácido Aspártico/química , Bacteriorodopsinas/química , Citoplasma/química , Sequência de Aminoácidos , Asparagina/genética , Ácido Aspártico/genética , Ácido Aspártico/fisiologia , Bacteriorodopsinas/genética , Bacteriorodopsinas/fisiologia , Transporte Biológico/genética , Sequência Conservada , Citoplasma/genética , Citoplasma/fisiologia , Halobacterium salinarum/genética , Concentração de Íons de Hidrogênio , Luz , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fotólise , Prótons , Membrana Purpúrea/química
18.
Drug Alcohol Depend ; 54(1): 11-8, 1999 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10101613

RESUMO

Six-month methadone-maintenance response and outcome were examined for African-American and Hispanic men and women in a large urban sample. A consistent pattern of improvement was indicated for both races and genders on the addiction severity index (ASI). There were virtually no statistically significant differences in ASI outcomes between Hispanics and African-Americans and men and women using conventional analysis of variance (ANOVA) procedures. Results from an additional equivalence analysis, however, indicated that baseline to 6-month changes for the different groups were generally not similar enough to consider them equivalent. Urine toxicologies obtained during the 6-month treatment period were also not statistically equivalent by race and gender. Evaluating outcomes by gender and race are discussed, as are the implications of using equivalence tests when examining group differences.


Assuntos
Negro ou Afro-Americano/psicologia , Hispânico ou Latino/psicologia , Metadona/uso terapêutico , Cooperação do Paciente , Transtornos Relacionados ao Uso de Substâncias/reabilitação , Análise de Variância , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/urina , Resultado do Tratamento , População Urbana
19.
Infect Control Hosp Epidemiol ; 19(11): 829-35, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9831938

RESUMO

OBJECTIVE: To assess the prevalence of tuberculosis (TB) or a positive skin test in healthcare workers (HCWs) providing services to human immunodeficiency virus (HIV)-infected individuals and to determine prospectively the incidence of new infections in this population. DESIGN: This prospective cohort study enrolled 1,014 HCWs working with HIV-infected populations from 10 metropolitan areas. Purified protein derivative (PPD) tuberculin skin tests were placed at baseline and every 6 months afterwards on those without a history of TB or a positive PPD. Demographic, occupational, and TB exposure data also were collected. SETTING: Outpatient clinics, hospitals, private practice offices, and drug treatment programs providing HIV-related healthcare and research programs. PARTICIPANTS: A voluntary sample of staff and volunteers from 16 Community Programs for Clinical Research on AIDS units. RESULTS: Factors related to prior TB or a positive skin test at baseline included being foreign-born, increased length of time in health care, living in New York City, or previous bacille Calmette-Guerin vaccination. The rate of PPD conversion was 1.8 per 100 person years of follow-up. No independent relation was found between the amount or type of contact with HIV-infected populations and the risk of TB infection. CONCLUSION: These data provide some reassurance that caring for HIV-infected patients is not related to an increased rate of TB infection among HCWs in these settings.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/transmissão , Pessoal de Saúde/estatística & dados numéricos , Transmissão de Doença Infecciosa do Paciente para o Profissional , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/transmissão , Adulto , Feminino , Humanos , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Fatores de Risco , Estados Unidos/epidemiologia
20.
Biophys J ; 75(3): 1455-65, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9726947

RESUMO

In the recently proposed local-access model for proton transfers in the bacteriorhodopsin transport cycle (Brown et al. 1998. Biochemistry. 37:3982-3993), connection between the retinal Schiff base and Asp85 (in the extracellular direction) and Asp96 (in the cytoplasmic direction)is maintained as long as the retinal is in its photoisomerized state. The directionality of the proton translocation is determined by influences in the protein that make Asp85 a proton acceptor and, subsequently, Asp96 a proton donor. The idea of concurrent local access of the Schiff base in the two directions is now put to a test in the photocycle of the D115N/D96N mutant. The kinetics had suggested that there is a single sequence of intermediates, L<-->M1<-->M2<-->N, and the M2-->M1 reaction depends on whether a proton is released to the extracellular surface. This is now confirmed. We find that at pH 5, where proton release does not occur, but not at higher pH, the photostationary state created by illumination with yellow light contains not only the M1 and M2 states, but also the L and the N intermediates. Because the L and M1 states decay rapidly, they can be present only if they are in equilibrium with later intermediates of the photocycle. Perturbation of this mixture with a blue flash caused depletion of the M intermediate, followed by its partial recovery at the expense of the L state. The change in the amplitude of the C=O stretch band at 1759 cm-1 demonstrated protonation of Asp85 in this process. Thus, during the reequilibration the Schiff base lost its proton to Asp85. Because the N state, also present in the mixture, arises by protonation of the Schiff base from the cytoplasmic surface, these results fulfill the expectation that under the conditions tested the extracellular access of the Schiff base would not be lost at the time when there is access in the cytoplasmic direction. Instead, the connectivity of the Schiff base flickers rapidly (with the time constant of the M1<-->M2 equilibration) between the two directions during the entire L-to-N segment of the photocycle.


Assuntos
Bacteriorodopsinas/química , Bacteriorodopsinas/efeitos da radiação , Ácido Aspártico/química , Ácido Aspártico/efeitos da radiação , Bacteriorodopsinas/genética , Fenômenos Biofísicos , Biofísica , Halobacterium salinarum/química , Halobacterium salinarum/genética , Halobacterium salinarum/efeitos da radiação , Concentração de Íons de Hidrogênio , Cinética , Luz , Modelos Químicos , Mutagênese Sítio-Dirigida , Fotoquímica , Conformação Proteica/efeitos da radiação , Prótons , Retinaldeído/química , Retinaldeído/efeitos da radiação , Bases de Schiff/química , Bases de Schiff/efeitos da radiação , Espectroscopia de Infravermelho com Transformada de Fourier
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