RESUMO
BACKGROUND: It is common for patients with neurofibromatosis type 2 to develop bilateral profound hearing loss hearing loss, and this is one of the main determinants of quality of life in this patient group. OBJECTIVES: The aim of this systematic review was to review the current literature regarding hearing outcomes of treatments for vestibular schwannomas in neurofibromatosis type 2 including conservative and medical management, radiotherapy, hearing preservation surgery and auditory implantation in order to determine the most effective way of preserving or rehabilitating hearing. SEARCH STRATEGY: A MESH search in PubMed using search terms (('Neurofibromatosis 2' [Mesh]) AND 'Neuroma, Acoustic'[Mesh]) AND 'Hearing Loss' [Mesh] was performed. A search using keywords was also performed. Studies with adequate hearing outcome data were included. With the exception of the cochlear implant studies (cohort size was very small), case studies were excluded. EVALUATION METHOD: The GRADE system was used to assess quality of publication. Formal statistical analysis of data was not performed because of very heterogenous data reporting. RESULTS: Conservative management offers the best chance of hearing preservation in stable tumours. The use of bevacizumab probably improves the likelihood of hearing preservation in growing tumours in the short term and is probably more effective than hearing preservation surgery and radiotherapy in preserving hearing. Of the hearing preservation interventions, hearing preservation surgery probably offers better hearing preservation rates than radiotherapy for small tumours but recurrence rates for hearing preservation surgery were high. For patients with profound hearing loss, cochlear implantation provides significantly better auditory outcomes than auditory brainstem implantation. Patients with untreated stable tumours are likely to achieve the best outcomes from cochlear implantation. Those who have had their tumours treated with surgery or radiotherapy do not gain as much benefit from cochlear implantation than those with untreated tumours. CONCLUSIONS: This review summarises the current literature related to hearing preservation/rehabilitation in patients with NF2. Whilst it provides indicative data, the quality of the data was low and should be interpreted with care. It is also important to consider that the management of vestibular schwannomas in NF2 is complex and decision-making is determined by many factors, not just the need to preserve hearing.
Assuntos
Perda Auditiva/etiologia , Perda Auditiva/terapia , Neurofibromatose 2/complicações , Perda Auditiva/diagnóstico , Humanos , Neurofibromatose 2/diagnóstico , Neurofibromatose 2/terapiaRESUMO
BACKGROUND: Neurofibromatosis type 2 (NF2) is an autosomal dominant condition with high spontaneous mutation rate which predisposes to the development of multiple nerve sheath tumours (schwannomas), meningiomas and ependymoma. The cardinal feature and main diagnostic criterion for the diagnosis of NF2 remains the development of bilateral vestibular schwannoma (BVS). With increasing use of MRI screening the possibility of a 'chance' diagnosis of BVS has been mooted with a potential frequency of one in two million people in their lifetime. Until now, however, no evidence for such an event has been published. We aimed to demonstrate that chance occurrence can occur and to estimate its frequency among those with just BVS late in life. METHODS: Two vestibular schwannomas from the same patient were DNA sequenced and underwent loss of heterozygosity analysis. RESULTS: We show that a man who developed BVS, at ages 52 and 67 years developed these tumours sporadically by demonstrating that there were no molecular events in common between the two tumours. Furthermore from a database of over 1200 patients with NF2, we have estimated that ~25% of cases of BVS over 50 years and 50% over 70 years of age where no other features of NF2 are present represent a chance occurrence rather than due to an underlying mosaic or constitutional NF2 mutation. CONCLUSIONS: Patients presenting with BVS later in life should be appraised of the potential likelihood they may not have NF2 and the resultant further reduction in risks of transmission to offspring.
Assuntos
Neuroma Acústico/diagnóstico , Neuroma Acústico/genética , Idade de Início , Idoso , Diagnóstico Diferencial , Genes da Neurofibromatose 2 , Humanos , Perda de Heterozigosidade , Pessoa de Meia-Idade , Mutação , Neurofibromatose 2/diagnóstico , Neurofibromatose 2/genéticaRESUMO
OBJECTIVES: Complicated fracture healing is often associated with the severity of surrounding muscle tissue trauma. Since inflammation is a primary determinant of musculoskeletal health and regeneration, it is plausible that delayed healing and non-unions are partly caused by compounding local inflammation in response to concomitant muscle trauma. METHODS AND RESULTS: To investigate this possibility, a Lewis rat open fracture model [tibia osteotomy with adjacent tibialis anterior (TA) muscle volumetric muscle loss (VML) injury] was interrogated. We observed that VML injury impaired tibia healing, as indicated by diminished mechanical strength and decreased mineralized bone within the fracture callus, as well as continued presence of cartilage instead of woven bone 28 days post-injury. The VML injured muscle presented innate and adaptive immune responses that were atypical of canonical muscle injury healing. Additionally, the VML injury resulted in a perturbation of the inflammatory phase of fracture healing, as indicated by elevations of CD3(+) lymphocytes and CD68+ macrophages in the fracture callus at 3 and 14d post-injury, respectively. CONCLUSIONS: These data indicate that heightened and sustained innate and adaptive immune responses to traumatized muscle are associated with impaired fracture healing and may be targeted for the prevention of delayed and non-union following musculoskeletal trauma.
Assuntos
Consolidação da Fratura/imunologia , Fraturas Expostas/patologia , Inflamação/patologia , Músculo Esquelético/lesões , Fraturas da Tíbia/patologia , Animais , Modelos Animais de Doenças , Fraturas Expostas/imunologia , Inflamação/imunologia , Masculino , Músculo Esquelético/imunologia , Músculo Esquelético/patologia , Ratos , Ratos Endogâmicos Lew , Reação em Cadeia da Polimerase em Tempo Real , Fraturas da Tíbia/imunologia , Microtomografia por Raio-XRESUMO
Volumetric muscle loss (VML) results in a large void deficient in the requisite materials for regeneration for which there is no definitive clinical standard of care. Autologous minced muscle grafts (MG), which contain the essential components for muscle regeneration, may embody an ideal tissue engineering therapy for VML. The purpose of this study was to determine if orthotopic transplantation of MG acutely after VML in the tibialis anterior muscle of male Lewis rats promotes functional tissue regeneration. Herein we report that over the first 16 wk postinjury, MG transplantation 1) promotes remarkable regeneration of innervated muscle fibers within the defect area (i.e., de novo muscle fiber regeneration); 2) reduced evidence of chronic injury in the remaining muscle mass compared with nonrepaired muscles following VML (i.e., transplantation attenuated chronically upregulated transforming growth factor-ß1 gene expression and the presence of centrally located nuclei in 30% of fibers observed in nonrepaired muscles); and 3) significantly improves net torque production (i.e., â¼55% of the functional deficit in nonrepaired muscles was restored). Additionally, voluntary wheel running was shown to reduce the heightened accumulation of extracellular matrix deposition observed within the regenerated tissue of MG-repaired sedentary rats 8 wk postinjury (collagen 1% area: sedentary vs. runner, â¼41 vs. 30%), which may have been the result of an augmented inflammatory response [i.e., M1 (CCR7) and M2 (CD163) macrophage expression was significantly greater in runner than sedentary MG-repaired muscles 2 wk postinjury]. These findings support further exploration of autologous minced MGs for the treatment of VML.
Assuntos
Desenvolvimento Muscular , Músculo Esquelético/transplante , Atrofia Muscular/cirurgia , Regeneração , Engenharia Tecidual/métodos , Animais , Biomarcadores/metabolismo , Fenômenos Biomecânicos , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Masculino , Atividade Motora , Contração Muscular , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Atrofia Muscular/genética , Atrofia Muscular/metabolismo , Atrofia Muscular/patologia , Atrofia Muscular/fisiopatologia , Ratos , Ratos Endogâmicos Lew , Recuperação de Função Fisiológica , Fatores de Tempo , Fator de Crescimento Transformador beta1/metabolismo , Transplante AutólogoRESUMO
BACKGROUND: South Africa (SA)'s high rate of interpersonal violence persists as a leading public health problem for the country. The first South African Comparative Risk Assessment Study (SACRA1) in 2000 quantified the long-term mental and physical health burden attributable to interpersonal violence by supplementing the direct injury burden of disease attributable to interpersonal violence injuries with the substantial contribution of mental health, behavioural and reproductive health consequences accruing from exposure to intimate partner violence (IPV) and child sexual abuse. OBJECTIVES: To revise and improve these estimates by including the additional burden from other forms of child maltreatment, community violence, sexual violence by non-partners, and bullying victimisation in SA for 2000, 2006 and 2012, and trends over time. METHODS: We used comparative risk assessment methods to calculate population attributable fractions (PAFs) for interpersonal violence. This method requires inputs on the prevalence of exposure to the interpersonal violence risk factor subtypes, namely child maltreatment, bullying, IPV, sexual violence by non-partners and other community violence; the burden of related health outcomes (mortality and morbidity); and relative risks of health outcomes in individuals exposed to the risk factor v. those unexposed. We estimated the PAF for the combinations of all interpersonal violence subtypes together to estimate the burden attributable to interpersonal violence overall for 2000, 2006 and 2012. RESULTS: Between 2000 and 2012, there was a decrease in interpersonal violence age-standardised attributable death rates from 100 to 71 per 100 000. In the second South African Comparative Risk Assessment Study (SACRA2), estimates of the attributable disability-adjusted life years (DALYs) for interpersonal violence for the year 2000 were revised, from 1.7 million to 2 million DALYs, taking into account attributable mortality and disability from additional forms of violence. There was a decrease in DALYs attributable to interpersonal violence from 2 million in 2000 to 1.75 million in 2012, accounting for 8.5% of the total burden for SA, ranking second highest, after unsafe sex, among 18 risk factors evaluated in 2012. CONCLUSION: Overall, interpersonal violence-attributable DALYs decreased substantially but remain high. The reduction in age-standardised attributable death rates indicates that some policy and social intervention aspects are effective. Further strengthening of existing laws pertaining to interpersonal violence, and other prevention measures, are needed to intensify the prevention of violence, particularly gender-based violence. Additional forms of violence included in this analysis have improved our understanding of the interpersonal violence burden, but the attributable burden in males, although exceedingly high, remains an underestimate. There is a need to improve the epidemiological data on prevalence and risks for the different types of interpersonal violence, particularly for males.
Assuntos
Maus-Tratos Infantis , Violência , Criança , Masculino , Humanos , África do Sul/epidemiologia , Percepção Social , Efeitos Psicossociais da DoençaRESUMO
BACKGROUND: The intersection of violence exposure and mental health problems is a public health crisis for South African (SA) adolescents. Understanding the impact of community violence on adolescent mental health can inform future interventions. OBJECTIVES: To assess pathways between community violence exposure and internalising and externalising problems in SA adolescents receiving mental healthcare, and the roles of parent and peer relationships in these associations. METHODS: Participants (N=120 parent-adolescent pairs) were recruited from four mental health clinics in Western Cape Province to participate in a pilot test of a family-based HIV prevention study. Adolescents reported on their exposure to community violence, parental attachment, peer support of risk behaviour, and mental health. Parents reported on adolescents' internalising and externalising mental health problems. Participants received transport money (ZAR30 = USD3) and a shopping voucher or cash (ZAR50 = USD5) for their time. RESULTS: Adolescents were 12 - 18 years old (mean (standard deviation) 14.39 (1.82) years), 53% were male, and 67% and 33% reported black African and mixed-race ethnicity, respectively. Parents were 94% female and reported an average monthly income of ZAR3â 973 (USD397). Boys reported significantly higher rates of witnessing community violence than girls. Among boys, significant paths emerged from community violence and low parent attachment to externalising symptoms and from community violence to peer support of risky behaviour. For girls, the only significant path was from low parent attachment to peer support of risky behaviour. CONCLUSIONS: This cross-sectional study sheds new light on the possible pathways from witnessing community violence to mental health problems among SA adolescents. Identifying factors that drive and mitigate psychological distress in the context of persistent community violence is critical to SA's future and can inform the selection and delivery of appropriate and targeted evidence-based interventions.
Assuntos
Comportamento do Adolescente/psicologia , Transtornos Mentais/epidemiologia , Saúde Mental , Violência/psicologia , Adolescente , Saúde do Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Relações Pais-Filho , Pais/psicologia , Grupo Associado , Projetos Piloto , Assunção de Riscos , Fatores Sexuais , África do SulRESUMO
BACKGROUND: Parenting programs based on social learning theory have increasing empirical evidence for reducing violence against children. Trials are primarily from high-income countries and with young children. Globally, we know little about how parenting programs work to reduce violence, with no known studies in low or middle-income countries (LMICs). This study examines mechanisms of change of a non-commercialized parenting program, Parenting for Lifelong Health for Teens, designed with the World Health Organization and UNICEF. A cluster randomized trial showed main effects on parenting and other secondary outcomes. We conducted secondary analysis of trial data to investigate five potential mediators of reduced violence against children: improved parenting, adolescent behaviour, caregiver mental health, alcohol/drug avoidance, and family economic strengthening. METHODS: The trial was implemented in rural South Africa with 40 sites, n = 552 family dyads (including adolescents aged 10-18 and primary caregivers). Intervention sites (n = 20) received the 14-session parenting program delivered by local community members, including modules on family budgeting and savings. Control sites (n = 20) received a brief informational workshop. Emotional and physical violence against children/adolescents and each potential mediator were reported by adolescents and caregivers at baseline and 9-13 months post-randomisation. Structural equation modelling was used to test simultaneous hypothesized pathways to violence reduction. RESULTS: Improvements in four pathways mediated reduced violence against children: 1) improved parenting practices, 2) improved caregiver mental health (reduced depression), 3) increased caregiver alcohol/drug avoidance and 4) improved family economic welfare. Improved child behaviour was not a mediator, although it was associated with less violence. CONCLUSIONS: Simultaneously bolstering a set of family processes can reduce violence. Supporting self-care and positive coping for caregivers may be essential in challenging contexts. In countries with minimal or no economic safety nets, linking social learning parenting programs with economic strengthening skills may bring us closer to ending violence against children.
Assuntos
Saúde Mental , Poder Familiar , Adolescente , Cuidadores , Criança , Pré-Escolar , Humanos , África do Sul , Violência/prevenção & controleRESUMO
Intracellular deposition of misfolded protein aggregates into ubiquitin-rich cytoplasmic inclusions is linked to the pathogenesis of many diseases. Why these aggregates form despite the existence of cellular machinery to recognize and degrade misfolded protein and how they are delivered to cytoplasmic inclusions are not known. We have investigated the intracellular fate of cystic fibrosis transmembrane conductance regulator (CFTR), an inefficiently folded integral membrane protein which is degraded by the cytoplasmic ubiquitin-proteasome pathway. Overexpression or inhibition of proteasome activity in transfected human embryonic kidney or Chinese hamster ovary cells led to the accumulation of stable, high molecular weight, detergent-insoluble, multiubiquitinated forms of CFTR. Using immunofluorescence and transmission electron microscopy with immunogold labeling, we demonstrate that undegraded CFTR molecules accumulate at a distinct pericentriolar structure which we have termed the aggresome. Aggresome formation is accompanied by redistribution of the intermediate filament protein vimentin to form a cage surrounding a pericentriolar core of aggregated, ubiquitinated protein. Disruption of microtubules blocks the formation of aggresomes. Similarly, inhibition of proteasome function also prevented the degradation of unassembled presenilin-1 molecules leading to their aggregation and deposition in aggresomes. These data lead us to propose that aggresome formation is a general response of cells which occurs when the capacity of the proteasome is exceeded by the production of aggregation-prone misfolded proteins.
Assuntos
Cisteína Endopeptidases/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Corpos de Inclusão/metabolismo , Proteínas de Membrana/metabolismo , Complexos Multienzimáticos/metabolismo , Organelas/fisiologia , Dobramento de Proteína , Animais , Células CHO , Linhagem Celular , Cricetinae , Cricetulus , Regulador de Condutância Transmembrana em Fibrose Cística/química , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Humanos , Rim/embriologia , Proteínas de Membrana/química , Microtúbulos/ultraestrutura , Organelas/ultraestrutura , Presenilina-1 , Complexo de Endopeptidases do Proteassoma , Deleção de Sequência , Ubiquitinas/fisiologia , Vimentina/metabolismoRESUMO
Class I major histocompatibility (MHC) antigens are expressed by virtually all mammalian cells, yet their levels of expression and behavior on the cell surface vary in a cell-specific fashion. A panel of lymphoid (both B and T) and nonlymphoid cell lines was used to study the kinetics of internalization of the H-2Ld class I MHC in different cell types. These studies revealed that endocytosis of H-2Ld occurs by both constitutive and PMA-regulated pathways in lymphoid cells, but only by a PMA-refractory pathway in the nonlymphoid cells tested. Transfectant derivatives of the T lymphoma, EL4, which express wild-type or mutant H-2Ld class I MHC antigens, were used to investigate the requirement for the cytoplasmic domain of the class I MHC antigen for its endocytosis in T lymphocytes. These studies showed that modification or deletion of the cytoplasmic domain of H-2Ld abrogates endocytosis via a PMA-regulated pathway. The role of cytoplasmic domain phosphorylation in PMA-inducible endocytosis was examined. The wild-type H-2Ld antigen is phosphorylated in all cell types examined, and this phosphorylation is up-regulated by PMA treatment. In contrast, cytoplasmic domain mutants of H-2Ld fail to be phosphorylated in vivo, in the presence or absence of PMA. The universality of PMA-inducible hyperphosphorylation of the class I MHC antigen among diverse cell types leads us to conclude that phosphorylation of the cytoplasmic domain, while perhaps necessary, is not sufficient for triggering endocytosis via a PMA-inducible pathway. Furthermore, the results with the cytoplasmic domain mutants of H-2Ld suggest that a structural conformation of the class I MHC cytoplasmic domain is required for endocytosis via this route.
Assuntos
Endocitose/efeitos dos fármacos , Antígenos H-2 , Acetato de Tetradecanoilforbol/farmacologia , Sequência de Aminoácidos , Animais , Linhagem Celular , Membrana Celular/imunologia , Membrana Celular/metabolismo , Deleção Cromossômica , Citoplasma/efeitos dos fármacos , Citoplasma/fisiologia , Genes MHC Classe I , Antígenos H-2/genética , Cinética , Dados de Sequência Molecular , MutaçãoRESUMO
Folding and oligomerization of most plasma membrane glycoproteins, including those involved in ion transport, occur in the ER and are frequently required for their exit from this organelle. It is currently unknown, however, where or when in the biosynthetic pathway these proteins become functionally active. AE1 and AE2 are tissue-specific, plasma membrane anion transport proteins. Transient expression of AE2 in a eukaryotic cell line leads to an increase in stilbene inhibitable whole cell 35SO4(2-)-efflux consistent with its function as a plasma membrane anion exchanger. No such increased transport activity was observed in AE1 transfectants, despite the fact that the two proteins were synthesized in roughly equal portions. In contrast, both AE1 and AE2 expression resulted in significant increase in Cl-/SO4(2-)-exchange in crude microsomes demonstrating that both AE1 and AE2 cDNAs encode functional proteins. Immunofluorescence staining and pulse-chase labeling experiments revealed that while 60% of AE2 is processed to the cell surface of transfectants, AE1 is restricted to an intracellular compartment and never acquires mature oligosaccharides. Crude microsomes from transfected cells were fractionated into plasma membrane and ER-derived vesicles by con A affinity chromatography. All of the AE1 and approximately half of the cellular AE2 was eluted with the ER vesicles, confirming their intracellular localization. Anion transport measurements on these fractions confirmed that the ER-restricted anion exchangers were functional. We conclude that AE1 and AE2 acquire the ability to mediate anion exchange at an early stage of their biosynthesis, before their exit from the ER.
Assuntos
Proteínas de Transporte de Ânions , Antiporters , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Animais , Ânions/metabolismo , Sequência de Bases , Linhagem Celular , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , DNA , Retículo Endoplasmático/metabolismo , Imunofluorescência , Humanos , Immunoblotting , Transporte de Íons , Rim/citologia , Camundongos , Microssomos/metabolismo , Dados de Sequência Molecular , Processamento de Proteína Pós-Traducional , Proteínas SLC4A , Sulfatos/metabolismoRESUMO
Ribavirin has a minor and transient effect on hepatitis C virus (HCV) replication and has been suggested to select a novel mutation, F415Y, in the RNA-dependent RNA polymerase of subtype 1a viruses. Twenty-nine patients with chronic hepatitis C (subtyped by INNO LiPA as 1a, 17; 1b, 11; 1a/1b, 1) who were nonresponders to interferon-based therapies were identified retrospectively and screened at Baseline, week 24 of treatment, and 24 weeks post-treatment. Selection of resistance mutations, including at amino acid position 415 of the polymerase, was investigated. Using clonal sequencing and pyrosequencing of the NS5B gene, we screened for the F415Y resistance mutation among patients who received combination therapy with ribavirin and interferon α. Of the 15 subtype 1a patients treated with interferon plus ribavirin, only one had the F415Y change at week 24, and an F/Y mixture was still present 24 weeks after therapy. Four additional patients in this group had the F415Y change 24 weeks post-therapy. The NS5B genes were sequenced in order to identify amino acid changes associated with ribavirin therapy, but no evidence was found that ribavirin selects for particular amino acids in the RNA-dependent RNA polymerase. Ribavirin, a weak inhibitor of HCV replication, does not select for resistance mutations in the sequence of the HCV RNA polymerase.
Assuntos
Farmacorresistência Viral , Hepacivirus/efeitos dos fármacos , Interferons/farmacologia , Mutação , Ribavirina/farmacologia , Seleção Genética , Proteínas não Estruturais Virais/genética , Adulto , Antivirais/farmacologia , Antivirais/uso terapêutico , Feminino , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Humanos , Interferons/uso terapêutico , Masculino , Pessoa de Meia-Idade , RNA Polimerase Dependente de RNA/genética , Ribavirina/uso terapêuticoRESUMO
OBJECTIVES: To assess critical incident exposure among prehospital emergency services personnel in the developing world context of South Africa; and to assess associated mental health consequences. METHODS: We recruited a representative sample from emergency services in the Western Cape Province, South Africa, to participate in this cross sectional epidemiological study. Questionnaires covered critical incident exposure, general psychopathology, risky alcohol use, symptoms of post-traumatic stress disorder (PTSD), and psychological and physical aggression between co-workers. Open ended questions addressed additional stressors. RESULTS: Critical incident exposure and rates of general psychopathology were higher than in studies in the developed world. Exposure to critical incidents was associated with general psychopathology, symptoms of PTSD, and with aggression between co-workers, but not with alcohol use. Ambulance, fire, and sea rescue services had lower general psychopathology scores than traffic police. The sea rescue service also scored lower than traffic police on PTSD and psychological aggression. The defence force had higher rates of exposure to physical assault, and in ambulance services, younger staff were more vulnerable to assault. Women had higher rates of general psychopathology and of exposure to psychological aggression. Other stressors identified included death notification, working conditions, and organisational problems. CONCLUSIONS: Service organisations should be alert to the possibility that their personnel are experiencing work -related mental health and behavioural problems, and should provide appropriate support. Attention should also be given to organisational issues that may add to the stress of incidents. Workplace programmes should support vulnerable groups, and address death notification and appropriate expression of anger.
Assuntos
Auxiliares de Emergência/psicologia , Estresse Psicológico/prevenção & controle , Análise e Desempenho de Tarefas , Adolescente , Adulto , Idoso , Agressão , Consumo de Bebidas Alcoólicas , Estudos Transversais , Feminino , Humanos , Masculino , Saúde Mental , Pessoa de Meia-Idade , África do Sul , Transtornos de Estresse Pós-Traumáticos/etiologia , Transtornos de Estresse Pós-Traumáticos/prevenção & controle , Estresse Psicológico/etiologiaRESUMO
The nucleotide sequence of bacteriophage T3 DNA, from gene 2.5 through gene 9 has been determined. In addition to regulatory sites, the sequence predicts 19 close-packed genes plus two genes that overlap, in a different reading frame, another gene. The majority of these genes are highly homologous to those in the corresponding region of bacteriophage T7. However, there are some genes that are present in one, but not the other, phage. These apparent deletions are almost exactly gene size and thus the close-packed organization of genes remains the same in T3 as in T7. The varying levels of homology between T3 and T7 DNAs, first noted by Davis and Hyman in their study of DNA heteroduplexes, are also demonstrated here by a comparison of T3 and T7 nucleotide sequences. Many regions of extremely high homology immediately abut sequences that have no apparent homology. These data suggest that bacteriophages T3 and T7 have recombined, both with each other and with other members of a pool of T7-like phages, during their co-evolution.
Assuntos
DNA Viral/genética , Genes Virais , Fagos T/genética , Proteínas Virais/genética , Proteínas Estruturais Virais/genética , Sequência de Aminoácidos , Sequência de Bases , Evolução Biológica , Teste de Complementação Genética , Ligação de Hidrogênio , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Biossíntese de Proteínas , RNA Viral/ultraestrutura , Mapeamento por Restrição , Homologia de Sequência do Ácido NucleicoRESUMO
BACKGROUND: The antiviral effect of anti-influenza drugs such as zanamivir may be demonstrated in patients as an increased rate of decline in viral load over a time course of treatment as compared with placebo. Historically this was measured using plaque assays, or Culture Enhanced Enzyme Linked Immunosorbent Assay (CE-ELISA). OBJECTIVES: to develop and characterise real time quantitative PCR (qPCR) assays to measure influenza A and B viral load in clinical samples, that offer improvements over existing methods, in particular virus infectivity assays. STUDY DESIGN: The dynamic range and robustness were established for the real time qPCR assays along with stability of the assay components. Cross validation of the real time PCR assays with CE-ELISA was performed by parallel testing of both serial dilutions of three different subtypes of cultured virus and a panel of influenza positive throat swab specimens. RESULTS: the assays were specific for influenza A and B and the dynamic ranges were at least seven logs. The assay variability was within acceptable limits but increased towards the lower limit of quantification, which was 3.33 log(10) viral cDNA copies/ml of virus transport medium (ten viral RNA copies/PCR). The components of the assay were robust enough to withstand extended storage and several freeze-thaw cycles. For the real time PCR assays the limit of quantification was equivalent to the virus infectivity cut off, which equates to a 93-fold increase in sensitivity. CONCLUSION: Well characterised real time PCR assays offer significant improvements over the existing methods for measuring the viral load of strains of influenza A and B in clinical specimens.
Assuntos
Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/virologia , Reação em Cadeia da Polimerase/métodos , DNA Complementar/genética , Ensaio de Imunoadsorção Enzimática , Humanos , Vírus da Influenza A/genética , Vírus da Influenza B/genética , Faringe/virologia , Reação em Cadeia da Polimerase/instrumentação , RNA Viral/análise , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Manejo de Espécimes , Carga Viral , Cultura de VírusRESUMO
The human genetic disease cystic fibrosis is caused by a single defective gene on chromosome 7 that codes for a 1480 amino acid protein called the cystic fibrosis transmembrane conductance regulator (CFTR). The defect causes a profound reduction of Cl- permeability in several tissues, which in turn impairs salt absorption and fluid secretion. A 25-80 pS, rectifying Cl- channel has been targeted as the exclusive or primary channel affected in CF. However, we have found no evidence for significant activation or spontaneous activity of this channel in cell-attached patches of normal lymphoblasts or dog tracheal cells. However, in dog tracheal cells, we find lower conductance, linear Cl- channels that are spontaneously active in unstimulated cells and may show increased activity in stimulated cells. Attempts to correlate the expression of mRNA for the CFTR protein in various types of cells with the presence of the rectifying Cl- channel show a lack of correlation: i.e., depolarization-activated rectifying Cl- channesl have been found in excised, inside-out patches from all cell types that we have examined to date, but the CFTR mRNA has so far only been detected in a subset of epithelial cells.
Assuntos
Fibrose Cística/metabolismo , Proteínas de Membrana/metabolismo , Animais , Canais de Cloreto , Cloretos/metabolismo , Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística , Humanos , Canais Iônicos/metabolismo , Proteínas de Membrana/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Seventy-three bacterial isolates from 65 horses with and without evidence of lower airway disease were identified to assess whether the association with disease was accounted for by a small or large number of species. Just over half (50.5 per cent were Actinobacillus equuli, 17.8 per cent were A suis-like, 11 per cent were Pasteurella pneumotropica, 8.2 per cent were A lignieresii, 6.8 per cent were P haemolytica and 5.5 per cent were P mairii. These results suggest that a range of Actinobacillus and Pasteurella species can be isolated from the lower airways of horses, with many of the isolates being A equuli. Among the horses examined, lower airway inflammation was significantly associated with A suis-like bacteria and A lignieresii. However, these two species constituted too small a proportion of the undifferentiated Actinobacillus/Pasteurella species to explain the association of this group of bacteria with lower airway disease. Since A equuli constituted just over 50 per cent of the group of bacteria it is possible that it too is playing a significant role in lower airway disease.
Assuntos
Actinobacillus/isolamento & purificação , Doenças dos Cavalos/microbiologia , Pasteurella/isolamento & purificação , Infecções Respiratórias/veterinária , Animais , Cavalos , Infecções Respiratórias/microbiologia , Sensibilidade e Especificidade , Traqueia/microbiologiaRESUMO
A 12-year-old girl presented with hemorrhaging at menarche and required multiple blood transfusions. She had a history of severe epistaxis. Bleeding studies indicated that the patient had type 1 von Willebrand's disease. Her three siblings were then screened and all tested positive for the disease.
Assuntos
Menarca , Hemorragia Uterina/etiologia , Doenças de von Willebrand/complicações , Adolescente , Adulto , Criança , Feminino , Humanos , Menorragia/etiologia , Doenças de von Willebrand/genética , Doenças de von Willebrand/terapiaRESUMO
UNLABELLED: Therapeutic shrinkage of prolactinomas with dopamine agonists achieves clinical benefit but can expose fistulae that have arisen as a result of bony erosion of the sella floor and anterior skull base by the invasive tumour, resulting in the potential development of cerebrospinal fluid (CSF) rhinorrhoea, meningitis, and rarely pneumocephalus. Onset of symptoms is typically within 4 months of commencing therapy. The management is typically surgical repair via an endoscopic transnasal transsphenoidal approach. A 23-year-old man presented to the Emergency Department with acute left limb weakness and intermittent headaches. Visual fields were full to confrontation. Immediate computed tomography and subsequent magnetic resonance imaging (MRI), demonstrated a 5âcm lobular/cystic mass invading the right cavernous sinus, displacing and compressing the midbrain, with destruction of the bony sella. He was referred to the regional pituitary multidisciplinary team (MDT). Serum prolactin was 159â455âmIU/l (7514.37âng/ml) (normal ranges 100-410âmIU/l (4.72-19.34âng/ml)). Cabergoline was commenced causing dramatic reduction in tumour size and resolution of neurological symptoms. Further dose titrations were required as the prolactin level plateaued and significant residual tumour remained. After 13 months of treatment, he developed continuous daily rhinorrhea, and on presenting to his general practitioner was referred to an otolaryngologist. When next seen in the routine regional pituitary clinic six-months later he was admitted for urgent surgical repair. Histology confirmed a prolactinoma with a low proliferation index of 2% (Ki-67 antibody). In view of partial cabergoline resistance he completed a course of conventional radiotherapy. Nine months after treatment the serum prolactin had fallen to 621âmIU/l, and 12 months after an MRI showed reduced tumour volume. LEARNING POINTS: CSF rhinorrhoea occurred 13 months after the initiation of cabergoline, suggesting a need for vigilance throughout therapy.Dedicated bony imaging should be reviewed early in the patient pathway to assess the potential risk of CSF rhinorrhoea after initiation of dopamine agonist therapy.There was a significant delay before this complication was brought to the attention of the regional pituitary MDT, with associated risk whilst left untreated. This demonstrates a need for patients and healthcare professionals to be educated about early recognition and management of this complication to facilitate timely and appropriate referral to the MDT for specialist advice and management. We changed our nurse-led patient education programme as a result of this case.An excellent therapeutic response was achieved with conventional radiotherapy after limited surgery having developed partial cabergoline resistance and CSF rhinorrhoea.