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1.
J Virus Erad ; 9(1): 100315, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36911658

RESUMO

The International Workshop on HIV Persistence during Therapy provides a forum in which HIV/AIDS researchers gather to share the latest research findings related to viral reservoirs and cure. The Tenth Workshop, which was attended by over 400 delegates, extended over 4 days and comprised eight sessions covering topics from the basic science of viral persistence to therapeutic approaches to HIV cure. Furthermore, satellite sessions on the first day of the Conference featuring cure research endeavours being pursued by the Bill and Melinda Gates Foundation as well as those being coordinated under the National Institutes of Health Martin Delaney Collaboratory program, provided important updates on research advances being made in these initiatives. As with previous conferences, the International Workshop on HIV Persistence during Therapy is primarily abstract-driven with only one invited talk for each of the sessions. This format, therefore, increases the number of presentations from early-stage investigators. Furthermore, presentations by Community representatives illustrated approaches to creating cure research literacy with effective messaging for the Community. The following article offers a synopsis of the meeting sessions. Due to space constraints, some presentations may have only been briefly discussed. Nevertheless, the Workshop abstracts can be found online (https://www/sciencedirect.com/journal/journal-of-virus-eradication/vol/8/suppl/S).

2.
Digit Health ; 8: 20552076221128678, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36386244

RESUMO

This paper summarizes the information technology-related research findings after 5 years with the INTROducing Mental health through Adaptive Technology project. The aim was to improve mental healthcare by introducing new technologies for adaptive interventions in mental healthcare through interdisciplinary research and development. We focus on the challenges related to internet-delivered psychological treatments, emphasising artificial intelligence, human-computer interaction, and software engineering. We present the main research findings, the developed artefacts, and lessons learned from the project before outlining directions for future research. The main findings from this project are encapsulated in a reference architecture that is used for establishing an infrastructure for adaptive internet-delivered psychological treatment systems in clinical contexts. The infrastructure is developed by introducing an interdisciplinary design and development process inspired by domain-driven design, user-centred design, and the person based approach for intervention design. The process aligns the software development with the intervention design and illustrates their mutual dependencies. Finally, we present software artefacts produced within the project and discuss how they are related to the proposed reference architecture. Our results indicate that the proposed development process, the reference architecture and the produced software can be practical means of designing adaptive mental health care treatments in correspondence with the patients' needs and preferences. In summary, we have created the initial version of an information technology infrastructure to support the development and deployment of Internet-delivered mental health interventions with inherent support for data sharing, data analysis, reusability of treatment content, and adaptation of intervention based on user needs and preferences.

3.
Sensors (Basel) ; 21(23)2021 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-34883949

RESUMO

Functional near-infrared spectroscopy (fNIRS) is a comparatively new noninvasive, portable, and easy-to-use brain imaging modality. However, complicated dexterous tasks such as individual finger-tapping, particularly using one hand, have been not investigated using fNIRS technology. Twenty-four healthy volunteers participated in the individual finger-tapping experiment. Data were acquired from the motor cortex using sixteen sources and sixteen detectors. In this preliminary study, we applied standard fNIRS data processing pipeline, i.e., optical densities conversation, signal processing, feature extraction, and classification algorithm implementation. Physiological and non-physiological noise is removed using 4th order band-pass Butter-worth and 3rd order Savitzky-Golay filters. Eight spatial statistical features were selected: signal-mean, peak, minimum, Skewness, Kurtosis, variance, median, and peak-to-peak form data of oxygenated haemoglobin changes. Sophisticated machine learning algorithms were applied, such as support vector machine (SVM), random forests (RF), decision trees (DT), AdaBoost, quadratic discriminant analysis (QDA), Artificial neural networks (ANN), k-nearest neighbors (kNN), and extreme gradient boosting (XGBoost). The average classification accuracies achieved were 0.75±0.04, 0.75±0.05, and 0.77±0.06 using k-nearest neighbors (kNN), Random forest (RF) and XGBoost, respectively. KNN, RF and XGBoost classifiers performed exceptionally well on such a high-class problem. The results need to be further investigated. In the future, a more in-depth analysis of the signal in both temporal and spatial domains will be conducted to investigate the underlying facts. The accuracies achieved are promising results and could open up a new research direction leading to enrichment of control commands generation for fNIRS-based brain-computer interface applications.


Assuntos
Interfaces Cérebro-Computador , Espectroscopia de Luz Próxima ao Infravermelho , Análise Discriminante , Humanos , Movimento , Máquina de Vetores de Suporte
4.
Am J Ophthalmol Case Rep ; 24: 101220, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34786517

RESUMO

PURPOSE: To present to and inform the practitioner of an unusual presentation of Varicella zoster virus and Ramsay-Hunt Syndrome. OBSERVATIONS: A 69-year-old bedbound male with vascular dementia presented to the emergency room with a red right eye with associated tearing and mucus production. The patient could not express if he was in pain. The initial diagnosis from the emergency room was bacterial keratitis, confirmed with a positive pseudomonas culture. However, upon examination by the ophthalmologist it was noted that there was not only a large, infected epithelial defect, but also an intraocular pressure of 35 and a candy-cane hypopyon. The diagnosis of herpes neurotrophic keratitis and iridocyclitis was made and the patient was started on intravenous acyclovir along with the appropriate topical medications. A day later, it was noted that the patient developed a right sided facial palsy and vesicular lesions inside the right ear canal, as confirmed by otolaryngology. CONCLUSION AND IMPORTANCE: Ramsay-Hunt Syndrome is usually known to the ophthalmologist due to the exposure keratopathy caused by facial palsy. This case demonstrates varicella-zoster virus (VZV) neurotrophic keratitis preceding the development of facial palsy, which can further exacerbate an already neurotrophic cornea. The practitioner should be aware of these signs and symptoms and adjust their treatment with systemic acyclovir-prednisone.

5.
Musculoskelet Surg ; 102(3): 257-260, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29150740

RESUMO

PURPOSE: Scheuermann kyphosis is the most common structural kyphosis among adolescence and young people. Surgical treatment may be performed through combined anterior and posterior or posterior-only approaches; to our knowledge, the efficacy of posterior-only approach as less invasive procedure is not well studied in case of severe rigid Scheuermann kyphosis. MATERIALS AND METHODS: Eighteen patients with severe rigid Scheuermann kyphosis operated through only posterior approach from 2013 to 2016 were evaluated. All information regarding demographic data, curve size before and after the surgery, surgical time, amount of blood loss, correction loss during follow-up and also complications was collected. RESULT: There were six females and 12 males. Mean age of the patients was 22.4 years (range 17-38). Mean kyphosis angle before surgery was 87.2° (range 85-105), and that reduced to 47.4° (range 45-55) after the surgery. Mean curve size in hyperextension view was 73.8°. Mean postoperative Cobb angle was 50-55 percent of preoperative curves. Mean hospital admission duration was 3.5 days after the index surgery (range 3-5 days). Mean blood loss during the surgery was 250 ml. Mean surgical duration time was 150 min. Mean follow-up period was 9 months (range 8-48 months). No complication was found among the patients. CONCLUSION: Posterior-only approach using advanced osteotomy techniques and posterior release is a safe and reliable approach for treatment of patients suffering from severe rigid Scheuermann kyphosis and provides acceptable deformity correction.


Assuntos
Doença de Scheuermann/cirurgia , Adolescente , Adulto , Perda Sanguínea Cirúrgica , Feminino , Seguimentos , Humanos , Tempo de Internação , Masculino , Duração da Cirurgia , Estudos Retrospectivos , Doença de Scheuermann/diagnóstico por imagem , Resultado do Tratamento , Adulto Jovem
6.
Front Hum Neurosci ; 10: 237, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27252637

RESUMO

In this study, we determine the optimal feature-combination for classification of functional near-infrared spectroscopy (fNIRS) signals with the best accuracies for development of a two-class brain-computer interface (BCI). Using a multi-channel continuous-wave imaging system, mental arithmetic signals are acquired from the prefrontal cortex of seven healthy subjects. After removing physiological noises, six oxygenated and deoxygenated hemoglobin (HbO and HbR) features-mean, slope, variance, peak, skewness and kurtosis-are calculated. All possible 2- and 3-feature combinations of the calculated features are then used to classify mental arithmetic vs. rest using linear discriminant analysis (LDA). It is found that the combinations containing mean and peak values yielded significantly higher (p < 0.05) classification accuracies for both HbO and HbR than did all of the other combinations, across all of the subjects. These results demonstrate the feasibility of achieving high classification accuracies using mean and peak values of HbO and HbR as features for classification of mental arithmetic vs. rest for a two-class BCI.

7.
J Hand Surg Eur Vol ; 41(4): 441-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26307139

RESUMO

Infected forearm nonunion is challenging to treat. We have used a vascularized pedicled bone graft from the distal ulna based on the posterior interosseous artery to treat forearm nonunion with current or previous signs of infection in six patients. Bone union was achieved after a mean of 3.8 months. After a mean follow-up of 25.7 months, no signs of persistent or reactivation of infection were seen in any patient. The mean Quick DASH score significantly improved from 77.4 to 17.6. In addition, the active range of motion of the wrist improved significantly after surgery. In our patients, a vascularized posterior interosseous pedicled bone from the distal ulna is a reliable vascularized bone graft for managing infected forearm nonunion.


Assuntos
Fraturas não Consolidadas/cirurgia , Osteomielite/cirurgia , Fraturas do Rádio/cirurgia , Fraturas da Ulna/cirurgia , Ulna/transplante , Adulto , Idoso , Desbridamento , Seguimentos , Fixação Interna de Fraturas , Consolidação da Fratura , Força da Mão , Humanos , Masculino , Pessoa de Meia-Idade , Ulna/irrigação sanguínea , Adulto Jovem
8.
Am J Orthop (Belle Mead NJ) ; 41(3): E39-42, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22530202

RESUMO

Neuropathic arthropathy (NA), or Charcot joint, is a chronic and progressive degenerative arthropathy associated with an underlying neurologic disorder. NA of the elbow is a rare entity, with few cases reported in the literature. We report the cases of 2 patients with NA of the elbow. In case 1, the probable etiology was an intramedullary lesion, most likely syringomyelia and likely diabetes mellitus. In case 2, the probable etiology was syringomyelia and likely diabetes mellitus. The aim in NA treatment is to manage the underlying disease and reduce the rate of deformity to its lowest level. Management of NA is usually conservative. The diagnosis of NA should be considered in destructive cases without an evident pain report, and the underlying neurologic problem should be addressed.


Assuntos
Artropatia Neurogênica/diagnóstico , Articulação do Cotovelo/patologia , Amplitude de Movimento Articular/fisiologia , Adulto , Artralgia/diagnóstico , Artralgia/etiologia , Artropatia Neurogênica/etiologia , Artropatia Neurogênica/terapia , Análise Química do Sangue , Dor Crônica/diagnóstico , Dor Crônica/etiologia , Terapia Combinada , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/tratamento farmacológico , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Medição de Risco , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento , Ultrassonografia Doppler/métodos
9.
J Hand Surg Eur Vol ; 33(5): 575-80, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18662958

RESUMO

Ten male patients with McGowan's grade III ulnar neuropathy due to traumatic cubitus valgus deformity underwent anterior subcutaneous ulnar transposition. Evaluation was performed using subjective and objective measures, and a modified Bishop score. After operation, subjective sensory and motor disturbances were improved or resolved in most of the patients, while objective measures improved less well. Improvement in two-point discrimination (2PD) was consistently associated with symptom relief. All of the patients reported satisfaction with the operation. There were no complications or recurrences. The results of ulnar nerve transposition in our patients were comparable to the results of this operation in patients with severe idiopathic cubital tunnel syndrome. Although the outcome of surgery is not always satisfactory in severe ulnar neuropathy, symptom relief may justify performing the operation.


Assuntos
Síndrome do Túnel Ulnar/etiologia , Síndrome do Túnel Ulnar/cirurgia , Articulação do Cotovelo , Fraturas do Úmero/complicações , Deformidades Articulares Adquiridas/complicações , Adulto , Idoso , Estudos de Coortes , Síndrome do Túnel Ulnar/fisiopatologia , Humanos , Fraturas do Úmero/diagnóstico , Fraturas do Úmero/fisiopatologia , Deformidades Articulares Adquiridas/diagnóstico por imagem , Deformidades Articulares Adquiridas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Radiografia , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
10.
Haemophilia ; 13(2): 182-8, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17286772

RESUMO

Repeated intra-articular bleeding with subsequent development of chronic synovitis and cartilage changes, leading to haemophilic arthropathy, is one the most debilitating problems in haemophilic patients. Radiosynovectomy is a familiar therapeutic choice in management of chronic synovitis in haemophilia. We report the treatments results of synoviorthesis with (32)P chromic phosphate with emphasis on clinical aspects. Between 2002 and 2006 we performed 66 procedures in 53 patients. Seven patients were excluded. The remaining 46 patients were followed for an average of 31 months. The mean age of patients at the time of injection was 15.9 years (range: 6-28). There were three repeat injections. According to Fernandez-pallazi and Cavilgia clinical classification (Table 1) [23], nine joints were Stage II and 46 were Stage III. In latest follow-up, 77% of patients reported at least a 50% decrease in bleeding frequency after treatment (P < 0.0001). The need for antihaemophilic factor consumption dropped by about 74% postradiosynovectomy (P < 0.0001). In most of the injected joints, the range of motion remained stable or improved. A trend was found for the number of haemarthrosis to increase after a period of considerable improvement. Synoviorthesis using (32)P effectively reduces the intra-articular bleeding rate and factor concentrate use. Durability of the response seems to be unpredictable, perhaps attributable to the late intervention. An early radiosynovectomy might be more helpful in terms of stability of response to treatment.


Assuntos
Compostos de Cromo/administração & dosagem , Hemartrose/radioterapia , Hemofilia A/complicações , Fosfatos/administração & dosagem , Compostos Radiofarmacêuticos/administração & dosagem , Sinovite/radioterapia , Adolescente , Adulto , Criança , Doença Crônica , Feminino , Humanos , Injeções Intra-Articulares , Irã (Geográfico) , Masculino , Resultado do Tratamento
11.
Cell Mol Life Sci ; 61(21): 2738-43, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15549175

RESUMO

Cellular entry of enveloped viruses is often dependent on attachment proteins expressed on the host cell surface. Viral envelope proteins bind these receptors, and, in an incompletely understood process, facilitate fusion of the cellular and viral membranes so as to introduce the viral core into the cytoplasm. Only a small fraction of viral receptors have been identified so far. Recently, a novel coronavirus was identified as the etiological agent of severe acute respiratory syndrome (SARS). The fusion protein gene of SARS coronavirus (SARS-CoV) was cloned and characterized, and shortly thereafter, angiotensin-converting enzyme 2 (ACE2) was shown to be its functional receptor. Identification of ACE2 as a receptor for SARS-CoV will likely contribute to the development of antivirals and vaccines. It may also contribute to the development of additional animal models for studying SARS pathogenesis, and could help identify the animal reservoir of SARS-CoV.


Assuntos
Carboxipeptidases/metabolismo , Receptores Virais/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/fisiologia , Enzima de Conversão de Angiotensina 2 , Animais , Humanos , Glicoproteínas de Membrana/metabolismo , Peptidil Dipeptidase A , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/química , Síndrome Respiratória Aguda Grave/virologia , Glicoproteína da Espícula de Coronavírus , Proteínas do Envelope Viral/metabolismo
12.
J Neurosci Res ; 74(3): 370-7, 2003 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-14598313

RESUMO

gamma-Secretase activity is involved in the generation of Abeta and therefore likely contributes to the pathology of Alzheimer's disease. Blocking this activity was seen as a major therapeutic target to slow down or arrest Abeta-related AD progression. This strategy seemed more doubtful when it was established that gamma-secretase also targets other substrates including Notch, a particularly important transmembrane protein involved in vital functions, at both embryonic and adulthood stages. We have described previously new non-peptidic inhibitors able to selectively inhibit Abeta cellular production in vitro without altering Notch pathway. We show here that in vivo, these inhibitors do not alter the Notch pathway responsible for somitogenesis in the zebrafish embryo. In addition, we document further the selectivity of JLK inhibitors by showing that, unlike other described gamma-secretase inhibitors, these agents do not affect E-cadherin processing. Finally, we establish that JLKs do not inhibit beta-site APP cleaving enzymes (BACE) 1 and BACE2, alpha-secretase, the proteasome, and GSK3beta kinase. Altogether, JLK inhibitors are the sole agents to date that are able to prevent Abeta production without triggering unwanted cleavages of other proteins.


Assuntos
Anticoagulantes/farmacologia , Carbamatos/farmacologia , Dipeptídeos/farmacologia , Endopeptidases/metabolismo , Proteínas de Membrana/metabolismo , Ácido gama-Aminobutírico/análogos & derivados , Secretases da Proteína Precursora do Amiloide , Peptídeos beta-Amiloides/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Western Blotting , Caderinas/metabolismo , Carbamatos/análise , Linhagem Celular/efeitos dos fármacos , Cisteína Endopeptidases/metabolismo , Dipeptídeos/análise , Relação Dose-Resposta a Droga , Embrião de Mamíferos/efeitos dos fármacos , Embrião não Mamífero , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Hibridização In Situ , Técnicas In Vitro , Rim , Complexos Multienzimáticos/metabolismo , Mutação , Fragmentos de Peptídeos/metabolismo , Testes de Precipitina , Complexo de Endopeptidases do Proteassoma , Receptores Notch , Fatores de Tempo , Transfecção/métodos , Triglicerídeos/farmacologia , Peixe-Zebra , Ácido gama-Aminobutírico/farmacologia
13.
J Exp Med ; 194(11): 1661-73, 2001 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-11733580

RESUMO

The chemokine receptor CCR5 plays an important role in leukocyte chemotaxis and activation, and also acts as a coreceptor for human and simian immunodeficiency viruses (HIV-1, HIV-2, and SIV). We provide evidence that CCR5 is O-glycosylated on serine 6 in the NH2 terminus. The O-linked glycans, particularly sialic acid moieties, significantly contribute to binding of the chemokine ligands. By contrast, removal of O-linked oligosaccharide exerted little effect on HIV-1 infection. Sulfation of specific tyrosine residues in the CCR5 NH2 terminus was important for efficient beta-chemokine binding. Thus, as has been observed for the binding of selectins and their ligands, O-linked carbohydrates and tyrosine sulfates play major roles in promoting the interaction of chemokines with CCR5. The resulting flexible arrays of negative charges on the CCR5 surface may allow specific, high-affinity interactions with diverse chemokine ligands. Although this is the first example of O-linked oligosaccharides and tyrosine sulfates playing a role in chemokine binding, the high density of serines, threonines and tyrosines in the N-termini of many CC chemokine receptors suggests that these posttranslational modifications may commonly contribute to chemokine binding.


Assuntos
Proteínas Inflamatórias de Macrófagos/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Polissacarídeos/metabolismo , Receptores CCR5/metabolismo , Sulfatos/metabolismo , Tirosina/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células CHO , Linhagem Celular , Linhagem Celular Transformada , Células Cultivadas , Quimiocina CCL4 , Cricetinae , Cães , Expressão Gênica , Glicosilação , HIV-1/metabolismo , HIV-1/fisiologia , Células HeLa , Humanos , Macrófagos , Dados de Sequência Molecular , Ligação Proteica , Receptores CCR5/genética , Vírus da Imunodeficiência Símia/metabolismo , Vírus da Imunodeficiência Símia/fisiologia
14.
J Virol ; 75(22): 10808-14, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11602722

RESUMO

Mast cells are critical components of innate and adaptive immunity that differentiate in tissues in situ from circulating committed progenitor cells. We now demonstrate that human cord blood-derived mast cell progenitors are susceptible to infection with macrophagetropic (M-tropic) and dualtropic human immunodeficiency virus type 1 (HIV-1) isolates but not with T-cell-tropic (T-tropic) strains. Mast cell progenitors (c-kit(+) CD13(+) cells with chloroacetate esterase activity) were purified from 4-week-old cultures of cord blood mononuclear cells maintained in stem cell factor, interleukin-6 (IL-6), and IL-10 using a CD14 depletion column. These progenitors expressed CCR3, CCR5, and CXCR4, as well as low levels of CD4. When infected in vitro with viruses pseudotyped with different HIV and simian immunodeficiency virus envelope glycoproteins, only M-tropic and dualtropic, but not T-tropic, viruses were able to enter mast cell progenitors. Both the CCR5-specific monoclonal antibody 2D7 and TAK-779, a nonpeptide inhibitor of CCR5-mediated viral entry, blocked HIV-1 strain ADA infection by >80%. Cultures infected with replication-competent virus produced progressively increasing amounts of virus for 21 days as indicated by p24 antigen detection. Mast cell progenitors that were exposed to an M-tropic, green fluorescent protein-expressing HIV-1 strain exhibited fluorescence indicative of viral entry and replication on a single-cell level and retained virus production during differentiation. The trafficking of mast cell progenitors to multiple tissues, combined with the long life span of mature mast cells, suggests that they could provide a widespread and persistent HIV reservoir in AIDS.


Assuntos
HIV-1/fisiologia , Mastócitos/virologia , Células-Tronco/virologia , Antígenos CD4/análise , Antígenos CD4/fisiologia , Células HeLa , Humanos , Receptores CCR3 , Receptores CCR5/análise , Receptores CCR5/fisiologia , Receptores CXCR4/análise , Receptores CXCR4/fisiologia , Receptores de Quimiocinas/fisiologia , Replicação Viral
15.
J Exp Med ; 193(9): 1059-66, 2001 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-11342590

RESUMO

The complement anaphylatoxin C5a and its seven-transmembrane segment (7TMS) receptor play an important role in host defense and in a number of inflammation-associated pathologies. The NH(2)-terminal domain of the C5a receptor (C5aR/CD88) contributes substantially to its ability to bind C5a. Here we show that the tyrosines at positions 11 and 14 of the C5aR are posttranslationally modified by the addition of sulfate groups. The sulfate moieties of each of these tyrosines are critical to the ability of the C5aR to bind C5a and to mobilize calcium. A C5aR variant lacking these sulfate moieties efficiently mobilized calcium in response to a small peptide agonist, but not to C5a, consistent with a two-site model of ligand association in which the tyrosine-sulfated region of the C5aR mediates the initial docking interaction. A peptide based on the NH(2) terminus of the C5aR and sulfated at these two tyrosines, but not its unsulfated analogue or a doubly sulfated control peptide, partially inhibited C5a association with its receptor. These observations clarify structural and mutagenic studies of the C5a/C5aR association and suggest that related 7TMS receptors are also modified by functionally important sulfate groups on their NH(2)-terminal tyrosines.


Assuntos
Antígenos CD/metabolismo , Complemento C5a/metabolismo , Processamento de Proteína Pós-Traducional , Receptores de Complemento/metabolismo , Sulfatos/metabolismo , Tirosina/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Cálcio/metabolismo , Linhagem Celular Transformada , Humanos , Dados de Sequência Molecular , Peptídeos/metabolismo , Receptor da Anafilatoxina C5a
16.
J Virol ; 74(24): 11972-6, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11090199

RESUMO

In addition to the CCR5 and CXCR4 chemokine receptors, a subset of primary human immunodeficiency virus type 1 (HIV-1) isolates can also use the seven-transmembrane-domain receptor APJ as a coreceptor. A previously identified ligand of APJ, apelin, specifically inhibited the entry of primary T-tropic and dualtropic HIV-1 isolates from different clades into cells expressing CD4 and APJ. Analysis of apelin analogues demonstrated that potent and specific antiviral activity was retained by a 13-residue, arginine-rich peptide. Antiviral potency was influenced by the integrity of methionine 75, which contributes to APJ-binding affinity, and by the retention of apelin residues 63 to 65. These studies demonstrate the ability of a small peptide ligand to block the function of APJ as an HIV-1 coreceptor, identify apelin sequences important for the inhibition, and provide new reagents for the investigation of the significance of APJ to HIV-1 infection and pathogenesis.


Assuntos
Síndrome da Imunodeficiência Adquirida/virologia , Proteínas de Transporte/fisiologia , HIV-1/fisiologia , Receptores de Dopamina D2/fisiologia , Receptores Acoplados a Proteínas G , Sequência de Aminoácidos , Apelina , Receptores de Apelina , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Ligantes , Dados de Sequência Molecular , Receptores Virais/fisiologia , Replicação Viral
17.
Proc Natl Acad Sci U S A ; 97(17): 9712-7, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10931940

RESUMO

Production of amyloid-beta protein (Abeta) is initiated by a beta-secretase that cleaves the Abeta precursor protein (APP) at the N terminus of Abeta (the beta site). A recently identified aspartyl protease, BACE, cleaves the beta site and at residue 11 within the Abeta region of APP. Here we show that BACE2, a BACE homolog, cleaves at the beta site and more efficiently at a different site within Abeta. The Flemish missense mutation of APP, implicated in a form of familial Alzheimer's disease, is adjacent to this latter site and markedly increases Abeta production by BACE2 but not by BACE. BACE and BACE2 respond identically to conservative beta-site mutations, and alteration of a common active site Arg inhibits beta-site cleavage but not cleavage within Abeta by both enzymes. These data suggest that BACE2 contributes to Abeta production in individuals bearing the Flemish mutation, and that selective inhibition of these highly similar proteases may be feasible and therapeutically advantageous.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Processamento de Proteína Pós-Traducional , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Secretases da Proteína Precursora do Amiloide , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/genética , Arginina/genética , Arginina/metabolismo , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/genética , Sítios de Ligação , Linhagem Celular , Clonagem Molecular , Endopeptidases , Perfilação da Expressão Gênica , Humanos , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Mutação de Sentido Incorreto/genética , Sistema Nervoso/enzimologia , Países Baixos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Fenilalanina/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Especificidade por Substrato , Suécia
18.
J Biol Chem ; 275(43): 33516-21, 2000 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-10938094

RESUMO

The sequential association of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 with CD4 and a seven-transmembrane segment coreceptor such as CCR5 or CXCR4 initiates entry of the virus into its target cell. The N terminus of CCR5, which contains several sulfated tyrosines, plays a critical role in the CD4-dependent association of gp120 with CCR5 and in viral entry. Here we demonstrate that a tyrosine-sulfated peptide based on the N terminus of CCR5, but not its unsulfated analogue, inhibits infection of macrophages and peripheral blood mononuclear cells by CCR5-dependent, but not CXCR4-dependent, HIV-1 isolates. The sulfated peptide also inhibited the association of CCR5-expressing cells with gp120-soluble CD4 complexes and, less efficiently, with MIP-1alpha. Moreover, this peptide inhibited the precipitation of gp120 by 48d and 23e antibodies, which recognize CD4-inducible gp120 epitopes, but not by several other antibodies that recognize proximal epitopes. The ability of the sulfated peptide to block 48d association with gp120 was dependent in part on seven tropism-determining residues in the third variable (V3) and fourth conserved (C4) domains of gp120. These data underscore the important role of the N-terminal sulfate moieties of CCR5 in the entry of R5 HIV-1 isolates and localize a critical contact between gp120 and CCR5.


Assuntos
Antivirais/farmacologia , Antígenos CD4/metabolismo , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/efeitos dos fármacos , Receptores CCR5/fisiologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células Cultivadas , Cães , HIV-1/fisiologia , Humanos , Dados de Sequência Molecular , Receptores CCR5/química , Relação Estrutura-Atividade , Sulfatos/farmacologia , Tirosina
19.
Nat Biotechnol ; 18(6): 649-54, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10835604

RESUMO

Seven-transmembrane segment, G protein-coupled receptors play central roles in a wide range of biological processes, but their characterization has been hindered by the difficulty of obtaining homogeneous preparations of native protein. We have created paramagnetic proteoliposomes containing pure and oriented CCR5, a seven-transmembrane segment protein that serves as the principal coreceptor for human immunodeficiency virus (HIV-1). The CCR5 proteoliposomes bind the HIV-1 gp120 envelope glycoprotein and conformation-dependent antibodies against CCR5. The binding of gp120 was enhanced by a soluble form of the other HIV-1 receptor, CD4, but did not require additional cellular proteins. Paramagnetic proteoliposomes are uniform in size, stable in a broad range of salt concentrations and pH, and can be used in FACS and competition assays typically applied to cells. Integral membrane proteins can be inserted in either orientation into the liposomal membrane. The magnetic properties of these proteoliposomes facilitate rapid buffer exchange useful in multiple applications. As an example, the CCR5-proteoliposomes were used to select CCR5-specific antibodies from a recombinant phage display library. Thus, paramagnetic proteoliposomes should be useful tools in the analysis of membrane protein interactions with extracellular and intracellular ligands, particularly in establishing screens for inhibitors.


Assuntos
Proteolipídeos/química , Receptores CCR5/química , Anticorpos Monoclonais/metabolismo , Antígenos CD4/química , Antígenos CD4/metabolismo , Linhagem Celular , Membrana Celular/química , Relação Dose-Resposta a Droga , Relação Dose-Resposta Imunológica , Eletroforese em Gel de Poliacrilamida , Citometria de Fluxo , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Ligantes , Bicamadas Lipídicas/química , Magnetismo , Microscopia Confocal , Modelos Biológicos , Biblioteca de Peptídeos , Ligação Proteica , Conformação Proteica , Receptores CCR5/imunologia , Receptores CCR5/metabolismo
20.
J Virol ; 74(12): 5716-25, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10823881

RESUMO

The human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins function as a membrane-anchored trimer of three gp120 exterior glycoproteins and three gp41 transmembrane glycoproteins. Previously, we reported three approaches to stabilize soluble trimers containing parts of the gp41 ectodomains: addition of GCN4 trimeric helices, disruption of the cleavage site between gp120 and gp41, and introduction of cysteines in the gp41 coiled coil to form intersubunit disulfide bonds. Here, we applied similar approaches to stabilize soluble gp140 trimers including the complete gp120 and gp41 ectodomains. A combination of fusion with the GCN4 trimeric sequences and disruption of the gp120-gp41 cleavage site resulted in relatively homogeneous gp140 trimers with exceptional stability. The gp120 epitopes recognized by neutralizing antibodies are intact and exposed on these gp140 trimers. By contrast, the nonneutralizing antibody epitopes on the gp120 subunits of the soluble trimers are relatively occluded compared with those on monomeric gp120 preparations. This antigenic similarity to the functional HIV-1 envelope glycoproteins and the presence of the complete gp41 ectodomain should make the soluble gp140 trimers useful tools for structural and immunologic studies.


Assuntos
Proteínas de Ligação a DNA , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/metabolismo , HIV-1/química , Proteínas de Saccharomyces cerevisiae , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular , Dissulfetos/metabolismo , Epitopos/imunologia , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/imunologia , HIV-1/genética , Humanos , Dados de Sequência Molecular , Peso Molecular , Ligação Proteica , Conformação Proteica , Engenharia de Proteínas , Proteínas Quinases/química , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Processamento de Proteína Pós-Traducional , Receptores de HIV/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Deleção de Sequência/genética , Solubilidade , Termodinâmica
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