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1.
J Intellect Disabil Res ; 64(2): 131-157, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31808223

RESUMO

BACKGROUND: While people with intellectual disability (ID) face disparities relating to sexual and reproductive health (SRH) services, little is known about the role of family caregivers who assist women and girls with ID access SRH services. This scoping review examined the findings of studies to elucidate the role of family caregivers with regard to SRH for women and girls with ID. METHOD: We used Arksey and O'Malley's six-stage scoping framework, with Levac, Colquhoun and O'Brien's revisions, to evaluate identified sources. We searched three electronic databases, six ID journals and reference lists in full-text articles. Inclusion criteria included (1) primary and secondary source research studies in peer-reviewed journals; (2) published in English; (3) all research methodologies (i.e. qualitative, quantitative, mixed methods and systematic reviews or commentaries); (4) published between 2000 and 2016; and (5) studies from any country. RESULTS: The search yielded 2062 studies; 57 articles met inclusion criteria. Most studies employed purposive, convenience or criterion sampling. Participants included people with ID, family caregivers, paid caregivers and health-care professionals. Findings were summarised thematically: (1) menstruation and menopause; (2) vaccinations and preventive screenings; (3) supporting sexuality and healthy relationships; (4) coordinating with health-care providers and (5) contraception and sterilisation. CONCLUSIONS: Findings from this scoping review underscore the need for more and better-quality research, including how family caregivers assist women and girls with ID access perinatal and preventive SRH services and sexual abuse education. Family caregivers, women and girls with ID and health-care providers need increased access to information about SRH.


Assuntos
Cuidadores , Acessibilidade aos Serviços de Saúde , Deficiência Intelectual/enfermagem , Serviços de Saúde Reprodutiva , Saúde Reprodutiva , Saúde Sexual , Adolescente , Adulto , Feminino , Humanos , Adulto Jovem
2.
J Intellect Disabil Res ; 61(1): 50-61, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27306542

RESUMO

BACKGROUND: Despite an increase in international studies examining the experiences of parents with intellectual impairments and their children, few have utilised population-based data. This study investigated the behavioural and cognitive outcomes of 3-year-old US children of mothers with intellectual impairments compared with children of mothers without intellectual impairments. METHODS: This study employed a secondary analysis of the Fragile Families Child and Wellbeing Study, a longitudinal birth cohort study in the US. Our analytic sample included mothers with intellectual impairments (n = 263) and a comparison group of mothers without intellectual impairments (n = 1298), as well as each sampled mother's focal child. When weighted, Fragile Families is representative of all births in US cities with populations over 200 000. RESULTS: Children of mothers with intellectual impairments had poorer behavioural and cognitive outcomes in comparison to same-age children of mothers without intellectual impairments. Notably, however, children of mothers with intellectual impairments were not at increased risk of being aggressive unless their family income was below 200% of the federal poverty level. Further, families headed by mothers with intellectual impairments experienced multiple hardships related to socioeconomic factors, limited social supports and poor self-reported health. CONCLUSION: Appropriate policies and programmes must be developed and implemented to effectively support these families, such as increased financial benefits.


Assuntos
Comportamento Infantil , Desenvolvimento Infantil , Filho de Pais com Deficiência/estatística & dados numéricos , Deficiência Intelectual/epidemiologia , Transtornos Mentais/epidemiologia , Mães/estatística & dados numéricos , Fatores Socioeconômicos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Idade Materna , Adulto Jovem
3.
J Small Anim Pract ; 51(6): 325-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20492455

RESUMO

An eight-year-old male Staffordshire bull terrier was presented with a bleeding mass in the urethral mucosa 1.5 cm distal to the ischial arch. After cytological findings suggestive of a squamous cell carcinoma and confirmation of the mass with urethroscopy, total penile amputation followed by transpelvic urethrostomy using an ischial symphyseal ostectomy was performed. The procedure successfully produced a tension-free anastomosis of the urethra to the skin in the scrotal position and no major complications were observed in the postoperative period. Histologically, the lesion was reported as a ruptured vascular structure with thrombosis and repair tissue. Seven months after surgery the dog is free of clinical signs.


Assuntos
Amputação Cirúrgica/veterinária , Doenças do Cão/cirurgia , Doenças do Pênis/veterinária , Pênis/cirurgia , Obstrução Uretral/veterinária , Animais , Cães , Masculino , Doenças do Pênis/cirurgia , Resultado do Tratamento , Obstrução Uretral/cirurgia , Derivação Urinária/veterinária , Micção/fisiologia
4.
Vet Pathol ; 45(2): 159-73, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18424828

RESUMO

Feline myeloma-related disorders (MRD) are rare neoplasms of plasma cells. The multistep transformation model of myeloma in humans is based on the premise that plasma cells undergo neoplastic transformation primarily within the intramedullary compartment and that over time they become poorly differentiated and metastasize to extramedullary locations. Historically, diagnostic criteria used for human multiple myeloma have been applied to the cat, with the assumption that feline MRD commonly arises in the intramedullary compartment. Our objectives were to describe the features of feline MRD confirmed by cytology, histopathology, histochemistry, and immunohistochemistry and to categorize these tumors. A priori hypotheses were 1) tumor category predicts survival and 2) cats with well-differentiated tumors commonly have extramedullary involvement in contrast to human myeloma patients. This multicenter, retrospective study identified 26 MRD cases. There was good agreement between histopathologic and cytologic tumor categorization. Histochemistry and immunohistochemistry were shown to be valuable adjunct tests in the diagnosis of MRD. Cats with well-differentiated tumors had increased median survival relative to those with poorly differentiated tumors (254 versus 14 days). We have reported that marked extramedullary involvement at initial clinical presentation is significantly more common in the cat than in human MRD patients. In this study, we demonstrate that cats with well-differentiated tumors more commonly have extramedullary involvement than human myeloma patients with well-differentiated tumors (90% versus 20%, P < 0.0002). These results contrast strongly with the human myeloma model of primary intramedullary neoplastic transformation and suggest that primary extramedullary neoplastic transformation may be more common in feline MRD.


Assuntos
Doenças do Gato/patologia , Mieloma Múltiplo/veterinária , Animais , Gatos , Feminino , Imuno-Histoquímica/veterinária , Estimativa de Kaplan-Meier , Masculino , Mieloma Múltiplo/patologia , Estudos Retrospectivos
5.
Eur Respir J ; 29(4): 793-803, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17400878

RESUMO

While asthma is an inflammatory disorder of the airways usually associated with atopy, an important additional component is involvement of the epithelium and underlying mesenchyme acting as a trophic unit (EMTU). In addition to allergens, a wide range of environmental factors interact with the EMTU, such as virus infections, environmental tobacco smoke and pollutants, to initiate tissue damage and aberrant repair responses that are translated into remodelling of the airways. While candidate gene association studies have revealed polymorphic variants that influence asthmatic inflammation, positional cloning of previously unknown genes is identifying a high proportion of novel genes in the EMTU. Dipeptidyl peptidase (DPP) 10 and disintegrin and metalloproteinase (ADAM)33 are newly identified genes strongly associated with asthma that are preferentially expressed in the airway epithelium and underlying mesenchyme, respectively. Also of increasing importance is the recognition that genes associated with asthma and atopy have important interactions with the environment through epigenetic mechanisms that influence their expression. This type of research will not only identify biomarkers of different types of asthma across the full range of phenotypic expression, but will also identify novel therapeutic targets that could influence the natural history of the heterogenes lung disease.


Assuntos
Asma/diagnóstico , Asma/genética , Asma/patologia , Proteínas ADAM/genética , Alérgenos , Dipeptidil Peptidases e Tripeptidil Peptidases/genética , Progressão da Doença , Meio Ambiente , Epitélio/metabolismo , Predisposição Genética para Doença , Humanos , Inflamação , Modelos Biológicos , Modelos Genéticos , Fatores de Risco , Fatores de Tempo
6.
Thorax ; 61(4): 313-9, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16449267

RESUMO

BACKGROUND: Transforming growth factor beta (TGF beta) upregulates a number of smooth muscle specific genes in (myo)fibroblasts. As asthma is characterised by an increase in airway smooth muscle, we postulated that TGFbeta(2) favours differentiation of asthmatic (myo)fibroblasts towards a smooth muscle phenotype. METHODS: Primary fibroblasts were grown from bronchial biopsy specimens from normal (n = 6) and asthmatic (n = 7) donors and treated with TGF beta2 to induce myofibroblast differentiation. The most stable genes for normalisation were identified using RT-qPCR and the geNorm software applied to a panel of 12 "housekeeping" genes. Expression of alpha-smooth muscle actin (alpha SMA), heavy chain myosin (HCM), calponin 1 (CPN 1), desmin, and gamma-actin were measured by RT-qPCR. Protein expression was assessed by immunocytochemistry and western blotting. RESULTS: Phospholipase A2 and ubiquitin C were identified as the most stably expressed and practically useful genes for normalisation of gene expression during myofibroblast differentiation. TGF beta2 induced mRNA expression for all five smooth muscle related transcripts; alpha SMA, HCM and CPN 1 protein were also increased but desmin protein was not detectable. Although there was no difference in basal expression, HCM, CPN 1 and desmin were induced to a significantly greater extent in asthmatic fibroblasts than in those from normal controls (p = 0.041 and 0.011, respectively). CONCLUSIONS: Although TGF beta2 induced the transcription of several smooth muscle related genes, not all were translated into protein. Thus, while TGF beta2 is unable to induce a bona fide smooth muscle cell phenotype, it may "prime" (myo)fibroblasts for further differentiation, especially if the cells are derived from asthmatic airways.


Assuntos
Asma/metabolismo , Brônquios/metabolismo , Fibroblastos/metabolismo , Células Musculares/metabolismo , Músculo Liso/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adulto , Asma/patologia , Diferenciação Celular , Células Cultivadas , Feminino , Humanos , Imuno-Histoquímica/métodos , Masculino , Músculo Liso/patologia , Fosfolipases A , Fosfolipases A2 , RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Fator de Crescimento Transformador beta2 , Ubiquitina C/metabolismo , Regulação para Cima
8.
J Biol Chem ; 276(32): 29782-91, 2001 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-11387341

RESUMO

Binding of the TATA-binding protein (TBP) to promoter DNA bearing the TATA sequence is an obligatory initial step in RNA polymerase II transcription initiation. The interactions of Saccharomyces cerevisiae TBP with the E4 (TATATATA) and adenovirus major late (TATAAAAG) promoters have been modeled via global analysis of kinetic and thermodynamic data obtained using fluorescence resonance energy transfer. A linear two-intermediate kinetic mechanism describes the reaction of both of these consensus strong promoters with TBP. Qualitative features common to both interactions include tightly bound TBP-DNA complexes with similar solution geometries, simultaneous DNA binding and bending, and the presence of intermediate TBP-DNA conformers at high mole fraction throughout most of the reaction and at equilibrium. Despite very similar energetic changes overall, the stepwise entropic and enthalpic compensations along the two pathways differ markedly following the initial binding/bending event. Furthermore, TBP-E4 dissociation ensues from both replacement and displacement processes, in contrast to replacement alone for TBP-adenovirus major late promoter. A model is proposed that explicitly correlates these similarities and differences with the sequence-specific structural properties inherent to each promoter. This detailed mechanistic comparison of two strong promoters interacting with TBP provides a foundation for subsequent comparison between consensus and variant promoter sequences reacting with TBP.


Assuntos
Proteínas E4 de Adenovirus/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Proteínas E4 de Adenovirus/metabolismo , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Cinética , Modelos Químicos , Ligação Proteica , Saccharomyces cerevisiae/metabolismo , Espectrometria de Fluorescência , Proteína de Ligação a TATA-Box , Temperatura , Termodinâmica , Fatores de Tempo , Fatores de Transcrição/genética
9.
J Virol ; 75(10): 4918-21, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11312365

RESUMO

Some echoviruses (EV) that bind decay-accelerating factor (DAF) also bind cells of human and murine origins in a DAF-independent manner. Pretreatment of cells with heparinase 1 or heparin blocks the binding of radiolabeled virus to the cell surface, and heparin prevents infection of rhabdomyosarcoma cells by certain EV, including several low-passage clinical isolates of EV 6 and some EV that do not bind DAF. These studies suggest that heparan sulfate may be of in vivo relevance as an attachment molecule for EV.


Assuntos
Enterovirus Humano B/metabolismo , Heparitina Sulfato/metabolismo , Receptores Virais/metabolismo , Células 3T3 , Animais , Antígenos CD55/genética , Antígenos CD55/fisiologia , Células CHO , Membrana Celular/metabolismo , Cricetinae , Heparina/análogos & derivados , Heparina/metabolismo , Heparina Liase/metabolismo , Humanos , Camundongos , Fosfolipases Tipo C/metabolismo
10.
J Biol Chem ; 276(18): 14623-7, 2001 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-11278275

RESUMO

The complex formed between the TATA-binding protein (TBP) and the "TATA box" of eukaryotic class II promoters is the foundation for assembly of the complex to which RNA polymerase II is ultimately recruited. TBP binds productively to canonical and diverse variant TATA sequences with >100-fold differences in transcription efficiency. Co-crystals of canonical sequences and >11 variant sequences bound to various TBP molecules all have approximately 80 degrees bends. In contrast, the bend angles for TBP-TATA complexes in solution, derived from distance distributions, are approximately 80 degrees for a canonical sequence but range from 30 degrees to 62 degrees for five variant sequences. We show in this study that the osmolytes used to crystallize TBP-TATA complexes induce profound increases in the DNA bends of two transcriptionally active TBP-bound variant sequences to a common angle of approximately 80 degrees but have little effect on a transcriptionally inactive variant. The effect of osmolyte on the TBP-induced DNA bend of a variant TATA box sequence is also manifest in the kinetics of association, demonstrating a functional consequence of an osmolyte-induced structural change.


Assuntos
Proteínas de Ligação a DNA/química , DNA/química , Conformação de Ácido Nucleico , Fatores de Transcrição/química , DNA/genética , Soluções , Proteína de Ligação a TATA-Box
11.
J Biol Chem ; 276(18): 14614-22, 2001 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-11278276

RESUMO

The TATA-binding protein (TBP) initiates assembly of transcription preinitiation complexes on eukaryotic class II promoters, binding to and restructuring consensus and variant "TATA box" sequences. The sequence dependence of the DNA structure in TBP-TATA complexes has been investigated in solution using fluorescence resonance energy transfer. The mean 5'dye-3'dye distance varies significantly among oligomers bearing the adenovirus major late promoter sequence (AdMLP) and five single-site variants bound to Saccharomyces cerevisiae TBP, consistent with solution bend angles for AdMLP of 76 degrees and for the variants ranging from 30 degrees to 62 degrees. These solution bends contrast sharply with the corresponding co-crystal structures, which show approximately 80 degrees bends for all sequences. Transcription activities for these TATA sequences are strongly correlated with the solution bend angles but not with TBP-DNA binding affinities. Our results support a model in which transcription efficiency derives primarily from the sequence-dependent structure of the TBP-TATA binary complex. Specifically, the distance distribution for the average solution structure of the TBP-TATA complex may reflect the sequence-dependent probability for the complex to assume a conformation in which the TATA box DNA is severely bent. Upon assumption of this geometry, the binary complex becomes a target for binding and correctly orienting the other components of the preinitiation complex.


Assuntos
Proteínas de Ligação a DNA/química , DNA/química , Conformação de Ácido Nucleico , TATA Box , Fatores de Transcrição/química , Sequência de Bases , DNA/genética , Soluções , Espectrometria de Fluorescência , Proteína de Ligação a TATA-Box
12.
Anesth Analg ; 90(6): 1423-7, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10825334

RESUMO

UNLABELLED: The neurotransmitter pathways involved in the mechanism of postanesthetic shivering (PAS) are poorly understood. Meperidine, clonidine, and physostigmine are all effective treatments, indicating that opioid, alpha(2)-adrenergic, and anticholinergic systems are probably involved. We investigated the effect of ondansetron, a 5-HT(3) antagonist used to treat postoperative nausea and vomiting, on intraoperative core and peripheral temperatures and PAS. Eighty-two patients (age, 18-60 yr) undergoing orthopedic, general, or urological surgery were randomized into three groups in this double-blinded, placebo-controlled, study: Group O4 (n = 27) received ondansetron 4 mg IV, Group O8 (n = 27) received ondansetron 8 mg IV, and Group C (n = 28) received saline IV immediately before the anesthetic induction. Core (tympanic) and fingertip temperature (dorsum of middle finger) were recorded. Anesthesia was induced with IV fentanyl 1 microg/kg and propofol 2.0-2.5 mg/kg and maintained with 1 minimum alveolar anesthetic concentration isoflurane in 70% nitrous oxide/oxygen. The occurrence of shivering was documented clinically during recovery by nursing staff, who were unaware of the group assignment. PAS occurred in 16 of 28 (57%) patients in Group C, compared with 9 of 27 (33%) in Group O4 (P = 0.13) and 4 of 27 (15%) patients in Group O8 (P = 0.003). Within each group, core temperature decreased and peripheral temperature increased significantly, but there were no significant differences among the groups at any time interval. We conclude that ondansetron 8 mg IV given during the induction of anesthesia prevents PAS without affecting the core-to-peripheral redistribution of heat during general anesthesia. This suggests that serotonergic pathways have a role in the regulation of PAS. IMPLICATIONS: In a randomized, double-blinded, placebo-controlled, clinical study, ondansetron 8 mg IV, given just before the induction, reduced the incidence of postanesthetic shivering compared with saline. The anticipated core-to-peripheral redistribution of body temperature during general anesthesia was not affected. This implies that ondansetron probably acts by a central inhibitory mechanism, and that 5-hydroxytryptaminergic pathways have a role in regulating postanesthetic shivering.


Assuntos
Anestesia Geral/efeitos adversos , Antieméticos/uso terapêutico , Ondansetron/uso terapêutico , Estremecimento/efeitos dos fármacos , Adulto , Temperatura Corporal/efeitos dos fármacos , Método Duplo-Cego , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Temperatura Cutânea/efeitos dos fármacos
13.
J Gen Virol ; 81(Pt 5): 1393-401, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10769083

RESUMO

A number of echoviruses use decay accelerating factor (DAF) as a cellular receptor or attachment protein for cell infection. Binding of echovirus 7 to DAF at the cell surface, but not to soluble DAF in solution, triggers the formation of virus particles exhibiting an altered sedimentation coefficient ('A' particles) which are considered indicative of the particle uncoating process. We have previously demonstrated that antibodies to beta(2)-microglobulin block cell infection at a stage prior to 'A' particle formation and suggested that this reflects the involvement of beta(2)-microglobulin (or the associated MHC-I) in a virus-receptor complex that forms at the cell surface. We demonstrate here that antiserum to CD59 specifically blocks infection of rhabdomyosarcoma cells by a range of echoviruses, including viruses that bind DAF (e. g. echovirus 7) and those that use currently unidentified receptors other than DAF. The block occurs prior to 'A' particle formation and is cell-type specific. The potential role of CD59 as an active member, or passive participant, in the virus-receptor complex is discussed.


Assuntos
Anticorpos Antivirais/imunologia , Antígenos CD59/fisiologia , Enterovirus Humano B/fisiologia , Rabdomiossarcoma/virologia , Animais , Antígenos CD55/imunologia , Antígenos CD55/metabolismo , Antígenos CD59/imunologia , Enterovirus Humano B/metabolismo , Soros Imunes , Camundongos , Coelhos , Receptores Virais/metabolismo , Células Tumorais Cultivadas , Vírion/metabolismo
14.
J Virol ; 74(7): 3410-2, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10708459

RESUMO

Picornavirus infection requires virus uncoating, associated with the production of 135S "A" particles and 80S empty particles from 160S mature virions, to release the RNA genome into the cell cytoplasm. Normal albumin inhibits this process. We now show that when depleted of fatty acids, albumin induces the formation of echovirus A particles.


Assuntos
Albuminas/fisiologia , Enterovirus Humano B/fisiologia , Ácidos Graxos/química , Vírion , Albuminas/química , Enterovirus Humano B/genética , Genoma Viral , RNA Viral
15.
J Gen Virol ; 80 ( Pt 2): 283-290, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10073686

RESUMO

Echoviruses induce a wide spectrum of diseases in man, the most severe being meningitis. In neonates, however, a severe systemic infection can be observed, leading to death. Serum albumin is the most abundant protein in plasma and most interstitial fluids, and its functions include osmoregulation and transport and delivery of hydrophobic molecules such as fatty acids and steroids. The results of cold-synchronized one-step growth analysis of echovirus 7 infection and sucrose-gradient analysis of A-particles suggest that physiological concentrations of albumin block echovirus 7 infection by inhibiting uncoating. The blockage was reversible and was still effective when albumin was added 30 min after virus adsorption. Inhibition of uncoating was confirmed by using rhodanine, a known specific inhibitor of echovirus uncoating. After removal of the albumin blockage, addition of rhodanine perpetuated the inhibition. Serum and interstitial albumin concentrations may limit echovirus infection in vivo and thereby act as an extracellular determinant for echovirus tropism.


Assuntos
Enterovirus Humano B/efeitos dos fármacos , Enterovirus Humano B/patogenicidade , Albumina Sérica/farmacologia , Animais , Capsídeo/efeitos dos fármacos , Capsídeo/fisiologia , Bovinos , Linhagem Celular , Efeito Citopatogênico Viral/efeitos dos fármacos , Infecções por Echovirus/etiologia , Infecções por Echovirus/prevenção & controle , Infecções por Echovirus/virologia , Enterovirus Humano B/fisiologia , Células HeLa , Humanos , Recém-Nascido , Poliovirus/efeitos dos fármacos , Poliovirus/patogenicidade , Poliovirus/fisiologia , Receptores Virais/efeitos dos fármacos , Receptores Virais/fisiologia , Soroalbumina Bovina/farmacologia , Virulência
16.
J Biol Chem ; 273(46): 30443-7, 1998 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-9804811

RESUMO

The biochemical properties of the molecular interactions mediating viral-cell recognition are poorly characterized. In this study, we use surface plasmon resonance to study the affinity and kinetics of the interaction of echovirus 11 with its cellular receptor decay-accelerating factor (CD55). As reported for interactions between cell-cell recognition molecules, the interaction has a low affinity (KD approximately 3.0 microM) as a result of a very fast dissociation rate constant (kon approximately 10(5) M-1.s-1, koff approximately 0.3 s-1). This contrasts with the interaction of soluble ICAM-1 (sICAM-1, CD54) with human rhinovirus 3 which has been reported to have a similar affinity but 10(2)-10(3)-fold slower kinetics (Casasnovas, J. M., and Springer, T. A. (1995) J. Biol. Chem. 270, 13216-13224). The extracellular portion of decay-accelerating factor comprises four short consensus repeat domains (domains 1-4) and a mucin-like stalk. By comparison of the binding affinity for echovirus 11 of various fragments of decay-accelerating factor, we are able to conclude that short consensus repeat domain 3 contributes approximately 80% of the binding energy.


Assuntos
Antígenos CD55/metabolismo , Enterovirus Humano B/metabolismo , Glicoproteínas de Membrana/metabolismo , Receptores Virais/metabolismo , Técnicas Biossensoriais , Linhagem Celular , Sequência Consenso , Humanos , Cinética , Pichia , Ligação Proteica , Proteínas Recombinantes/metabolismo
17.
J Gen Virol ; 79 ( Pt 7): 1707-13, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9680134

RESUMO

Several echoviruses (EVs) have previously been shown to use decay accelerating factor (DAF) as a cellular receptor. Since DAF is expressed on erythrocytes, EVs that use this receptor cause haemagglutination. Here we show that all EVs that haemagglutinate do so via attachment to DAF and that this interaction can be inhibited by a monoclonal antibody (MAb) specific for DAF domain SCR3. Although the viruses haemagglutinate via DAF some can bind to rhabdomyosarcoma cells from which DAF has been removed and infect in the presence of a MAb against DAF. This suggests that some EVs have the capacity to interact with more than one cellular receptor.


Assuntos
Antígenos CD55/metabolismo , Enterovirus Humano B/metabolismo , Receptores Virais/metabolismo , Animais , Anticorpos Monoclonais/metabolismo , Antígenos CD55/genética , Antígenos CD55/imunologia , Linhagem Celular , Echovirus 6 Humano/metabolismo , Hemaglutinação , Testes de Inibição da Hemaglutinação , Humanos , Camundongos , Fosfatidilinositol Diacilglicerol-Liase , Radioisótopos de Enxofre , Células Tumorais Cultivadas , Fosfolipases Tipo C/metabolismo , Fosfolipases Tipo C/farmacologia
18.
J Virol ; 72(7): 5360-5, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9620989

RESUMO

A monoclonal antibody (MAb) that blocks most echoviruses (EVs) from infecting rhabdomyosarcoma (RD) cells has been isolated. By using the CELICS cloning method (T. Ward, P. A. Pipkin, N. A. Clarkson, D. M. Stone, P. D. Minor, and J. W. Almond, EMBO J. 13:5070-5074, 1994), the ligand for this antibody has been identified as beta2-microglobulin (beta2m), the 12-kDa protein that associates with class I heavy chains to form class I HLA complexes. A commercial MAb (MAb 1350) against beta2m was also found to block EV7 infection without affecting binding to its receptor, DAF, or replication of EV7 viral RNA inside cells. Entry of EV7 into cells was reduced by only 30% by antibody and cytochalasin D, an inhibitor of endocytosis mediated by caveolae and clathrin-coated pits, but was not significantly reduced by sodium azide. The block to virus entry by cytochalasin D was additive to the block induced by antibody. We suggest that EV7 rapidly enters into a multicomponent receptor complex prior to entry into cells and that this initial entry event requires beta2m or class I HLA for infection to proceed.


Assuntos
Enterovirus Humano B/fisiologia , Rabdomiossarcoma/virologia , Microglobulina beta-2/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Células COS , Células HeLa , Antígenos de Histocompatibilidade Classe I/fisiologia , Humanos , Camundongos , Testes de Neutralização , Replicação Viral
19.
Transfusion ; 38(4): 332-6, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9595014

RESUMO

BACKGROUND: Cromer blood group antigens are located on decay-accelerating factor (DAF, CD55), which contains four short consensus repeats (SCRs). Cromer system antibodies may be of clinical significance in blood transfusion. STUDY DESIGN AND METHODS: Soluble recombinant DAF (srDAF) constructs, consisting of all four SCRs or of only two SCRs, were expressed in the yeast Pichia pastoris. They are used in hemagglutination-inhibition tests with Cromer system antibodies and with DAF-specific monoclonal antibodies. RESULTS: The srDAF inhibited hemagglutination by all Cromer system alloantibodies in undiluted serum. Antibodies to antigens of other blood group systems were not inhibited by the srDAF. Hemagglutination-inhibition tests with domain-deleted srDAF showed that UMC is on SCR-4 and confirmed that Tca, TcaTcb, and WESb are on SCR-1; Dra is on SCR-3; and Cra is on SCR-4. CONCLUSIONS: Hemagglutination inhibition with srDAF is useful in the recognition of antibodies that belong to the Cromer blood group system and facilitates pretransfusion testing. This use of domain-deleted srDAF provides an easy method of determining epitope location on DAF and is an aid to more precise identification of Cromer system antibodies.


Assuntos
Antígenos de Grupos Sanguíneos/imunologia , Antígenos CD55/genética , Antígenos CD55/imunologia , Testes de Inibição da Hemaglutinação/métodos , Antígenos CD55/química , Humanos , Isoanticorpos/sangue , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/imunologia , Solubilidade
20.
J Virol ; 71(12): 9306-12, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9371589

RESUMO

Soluble forms of decay-accelerating factor (DAF) (CD55), the receptor for echovirus 7, were synthesized in the yeast Pichia pastoris. Purified recombinant protein containing SCR domains 2, 3, and 4, but lacking the serine/threonine rich region, was shown to block infection of susceptible cells by echovirus 7. In contrast to the situation with poliovirus and its receptor, the neutralization of echovirus 7 by soluble DAF was completely reversible and did not lead to the formation of 135S A-particles. Binding of virus to susceptible cells, by contrast, did lead to the formation of A particles, mainly from virus that had been internalized. The data suggest that a secondary factor(s) may contribute to A-particle formation and uncoating of echovirus 7.


Assuntos
Antígenos CD55/metabolismo , Enterovirus Humano B/metabolismo , Receptores Virais/metabolismo , Antígenos CD55/genética , Células HeLa , Humanos , Testes de Neutralização , Poliovirus/fisiologia , Receptores Virais/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Deleção de Sequência , Vírion/fisiologia
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