Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
1.
J Hosp Infect ; 149: 26-35, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38705476

RESUMO

BACKGROUND: The environmental surveillance of air grilles in clinical areas has not been systematically analysed. METHODS: Samples were collected from frequently touched items (N = 529), air supply (N = 295) and exhaust (N = 184) grilles in six medical and 11 surgical wards for the cultures of multi-drug-resistant organisms (MDROs): meticillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenemase-producing Enterobacterales (CPE), and isolates were selected for whole-genome sequencing (WGS). The contamination rates were correlated with the colonization pressures of the respective MDROs. RESULTS: From 3rd October to 21st November 2023, 9.8% (99/1008) of the samples tested positive, with MRSA (24.2%, 24/99), CRAB (59.6%, 59/99) and CPE (2.0%, 2/99), being the only detected MDROs. The contamination rate in air exhaust grilles (26.6%, 49/184) was significantly higher than in air supply grilles (5.8%, 17/295; P<0.001). The contamination rate of air exhaust grilles with any MDRO in acute medical wards (73.7%, 14/19) was significantly higher than in surgical wards (12.5%, 4/32; P<0.001). However, there was no difference in the contamination rate of air exhaust grilles between those located inside and outside the cohort cubicles for MDROs (27.1%, 13/48 vs 28.8%, 30/104; P=0.823). Nevertheless, the weekly CRAB colonization pressure showed a significant correlation with the overall environmental contamination rate (r = 0.878; 95% confidence interval (CI): 0.136-0.986; P=0.004), as well as with the contamination rate in air supply grilles (r = 0.960; 95% CI: 0.375-0.999; P<0.001) and air exhaust grilles (r = 0.850; 95% CI: 0.401-0.980; P=0.008). WGS demonstrated clonal relatedness of isolates collected from patients and air exhaust grilles. CONCLUSIONS: Air grilles may serve as MDRO reservoirs. Cohort nursing in open cubicles may not completely prevent MDRO transmission through air dispersal, prompting the consideration of future hospital design.

5.
J Hosp Infect ; 123: 52-60, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35196559

RESUMO

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) infections are rampant in hospitals and residential care homes for the elderly (RCHEs). AIM: To analyse the prevalence of MRSA colonization among residents and staff, and degree of environmental contamination and air dispersal of MRSA in RCHEs. METHODS: Epidemiological and genetic analysis by whole-genome sequencing (WGS) in 12 RCHEs in Hong Kong. FINDINGS: During the COVID-19 pandemic (from September to October 2021), 48.7% (380/781) of RCHE residents were found to harbour MRSA at any body site, and 8.5% (8/213) of staff were nasal MRSA carriers. Among 239 environmental samples, MRSA was found in 39.0% (16/41) of randomly selected resident rooms and 31.3% (62/198) of common areas. The common areas accessible by residents had significantly higher MRSA contamination rates than those that were not accessible by residents (37.2%, 46/121 vs. 22.1%, 17/177, P=0.028). Of 124 air samples, nine (7.3%) were MRSA-positive from four RCHEs. Air dispersal of MRSA was significantly associated with operating indoor fans in RCHEs (100%, 4/4 vs. 0%, 0/8, P=0.002). WGS of MRSA isolates collected from residents, staff and environmental and air samples showed that ST 1047 (CC1) lineage 1 constituted 43.1% (66/153) of all MRSA isolates. A distinctive predominant genetic lineage of MRSA in each RCHE was observed, suggestive of intra-RCHE transmission rather than clonal acquisition from the catchment hospital. CONCLUSION: MRSA control in RCHEs is no less important than in hospitals. Air dispersal of MRSA may be an important mechanism of dissemination in RCHEs with operating indoor fans.


Assuntos
COVID-19 , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Idoso , COVID-19/epidemiologia , Portador Sadio/epidemiologia , Humanos , Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Pandemias , Infecções Estafilocócicas/epidemiologia
6.
J Hosp Infect ; 116: 78-86, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34403765

RESUMO

AIM: To describe the nosocomial transmission of Air, multidrug-resistant, Acinetobacter baumannii, nosocomial, COVID-19 Acinetobacter baumannii (MRAB) in an open-cubicle neurology ward with low ceiling height, where MRAB isolates collected from air, commonly shared items, non-reachable high-level surfaces and patients were analysed epidemiologically and genetically by whole-genome sequencing. This is the first study to understand the genetic relatedness of air, environmental and clinical isolates of MRAB in the outbreak setting. FINDINGS: Of 11 highly care-dependent patients with 363 MRAB colonization days during COVID-19 pandemic, 10 (90.9%) and nine (81.8%) had cutaneous and gastrointestinal colonization, respectively. Of 160 environmental and air samples, 31 (19.4%) were MRAB-positive. The proportion of MRAB-contaminated commonly shared items was significantly lower in cohort than in non-cohort patient care (0/10, 0% vs 12/18, 66.7%; P<0.001). Air dispersal of MRAB was consistently detected during but not before diaper change in the cohort cubicle by 25-min air sampling (4/4,100% vs 0/4, 0%; P=0.029). The settle plate method revealed MRAB in two samples during diaper change. The proportion of MRAB-contaminated exhaust air grills was significantly higher when the cohort cubicle was occupied by six MRAB patients than when fewer than six patients were cared for in the cubicle (5/9, 55.6% vs 0/18, 0%; P=0.002). The proportion of MRAB-contaminated non-reachable high-level surfaces was also significantly higher when there were three or more MRAB patients in the cohort cubicle (8/31, 25.8% vs 0/24, 0%; P=0.016). Whole-genome sequencing revealed clonality of air, environment, and patients' isolates, suggestive of air dispersal of MRAB. CONCLUSIONS: Our findings support the view that patient cohorting in enclosed cubicles with partitions and a closed door is preferred if single rooms are not available.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , COVID-19 , Infecção Hospitalar , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Pandemias , SARS-CoV-2
8.
Artigo em Inglês | MEDLINE | ID: mdl-33567728

RESUMO

BACKGROUND: A burgeoning literature has found relationships between telomere length, telomerase activity, and human health and longevity. Although some research links a history of childhood adversity with shortened telomere length, our review found no prior research on the relationship between child maltreatment history and telomerase activity in adulthood. We hypothesized a negative relationship between child maltreatment and telomerase activity and hypothesized that the association would be moderated by sex. METHODS: These relationships were tested on a sample of 262 Hong Kong Chinese adults (200 females versus 62 males) with mild to moderate depression. RESULTS: Counterintuitively, emotional abuse was positively associated with telomerase activity, while other maltreatment types were non-significant. The positive relationship between emotional abuse and telomerase activity was significantly moderated by the sex of the participant. CONCLUSIONS: We advance two possible explanations for this finding (1) a culturally informed resilience explanation and (2) a homeostatic complexity explanation. The two explanations are not mutually exclusive. This trial is registered under Hong Kong Clinical Trial Register number HKCTR-1929. SIGNIFICANCE STATEMENT: Emotional abuse was significantly positively associated with telomerase activity. There are at least two non-mutually exclusive explanations for the findings. Simply put, either (1) in the cultural context of Hong Kong emotional abuse was not a risk factor, and/or (2) the conceptualization of telomerase activity as a straightforward indicator of longevity is overly simplistic. The first story we might term a "resilience explanation" while the second we might call a "homeostatic complexity" story.


Assuntos
Maus-Tratos Infantis , Telomerase , Adulto , Criança , Abuso Emocional , Feminino , Hong Kong , Humanos , Masculino , Inquéritos e Questionários , Telômero , Encurtamento do Telômero
9.
PLoS One ; 15(5): e0232932, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413063

RESUMO

Childhood sexual abuse (CSA) has been shown to predict the coupling of depression and inflammation in adulthood. Trust within intimate relationships, a core element in marital relations, has been shown to predict positive physical and mental health outcomes, but the mediating role of trust in partners in the association between CSA and inflammation in adulthood requires further study. The present study aimed to examine the impact of CSA on inflammatory biomarkers (IL-6 and IL-1ß) in adults with depression and the mediating role of trust. A cross-sectional survey data set of adults presenting with mood and sleep disturbance was used in the analysis. CSA demonstrated a significant negative correlation with IL-6 level (r = -0.28, p<0. 01) in adults with clinically significant depression, while trust showed a significant positive correlation with IL-6 level (r = 0.36, p < .01). Sobel test and bootstrapping revealed a significant mediating role for trust between CSA and IL-6 level. CSA and trust in partners were revealed to have significant associations with IL-6 level in adulthood. Counterintuitively, the directions of association were not those expected. Trust played a mediating role between CSA and adulthood levels of IL-6. Plausible explanations for these counterintuitive findings are discussed.


Assuntos
Sobreviventes Adultos de Maus-Tratos Infantis/psicologia , Interleucina-6/imunologia , Confiança/psicologia , Adulto , Criança , Abuso Sexual na Infância/psicologia , Estudos Transversais , Depressão/metabolismo , Feminino , Humanos , Inflamação/imunologia , Interleucina-1beta/análise , Interleucina-1beta/sangue , Interleucina-6/análise , Interleucina-6/sangue , Relações Interpessoais , Masculino , Casamento/psicologia , Transtornos Mentais/psicologia , Pessoa de Meia-Idade , Fatores de Risco , Parceiros Sexuais/psicologia
10.
Transplant Proc ; 50(10): 3144-3151, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30577180

RESUMO

Anastomosing the renal artery and vein in transplant recipients without a cooling mechanism exposes the kidney to temperatures exceeding the metabolic threshold (15°C to 18°C), at which the protective effects of renal hypothermia are lost. This anastomotic time, or second warm ischemic time, can be deleterious to graft outcomes, especially if it is prolonged. Techniques to ameliorate organ warming prior to reperfusion have been designed, and range from simpler surface cooling techniques, to organ immersion in bags of ice slush, and the application of 'jackets' that incorporate their own internal cooling mechanism. The efficacy of these methods with respect to the minimization of kidney temperature prior to reperfusion and subsequent effects on graft outcomes are discussed using clinical and experimental data, in the setting of open, laparoscopic, and robotic kidney transplantation.


Assuntos
Hipotermia Induzida/métodos , Transplante de Rim/métodos , Laparoscopia/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Isquemia Quente/métodos , Anastomose Cirúrgica , Temperatura Corporal , Humanos , Rim/irrigação sanguínea , Artéria Renal
11.
Mol Genet Metab Rep ; 17: 3-8, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30181955

RESUMO

BACKGROUND AND OBJECTIVES: This retrospective study analysed a case series of subjects with citrin deficiency, and aims to present the molecular and clinical characterization of this disease in the Hong Kong Chinese population for the first time. PATIENTS AND METHODS: Data from medical records of eighteen patients with citrin deficiency (years 2006-2015) were retrieved. Demographic data, biochemical parameters, radiological results, genetic testing results, management, and clinical outcome were collected and analysed. RESULTS: Eighteen patients with diagnosis of citrin deficiency were recruited. All 18 patients carried at least one common pathogenic variant c.852_855delTATG in SLC25A13. Prolonged jaundice (neonatal intrahepatic cholestasis caused by citrin deficiency, NICCD) was the most common presenting symptom, in conjunction with elevated plasma citrulline, threonine, alkaline phosphatase, and alpha-fetoprotein levels. The abnormal biochemical parameters including liver derangement returned to normal range in most of the cases by 6 months of age after the introduction of a lactose-free formula. There were a few cases with atypical presentations. Two subjects did not present with NICCD, and were subsequently diagnosed later in life after their siblings presented with symptoms of citrin deficiency at one month of age and subsequently received a molecular diagnosis. One patient with citrin deficiency also exhibited multiple liver hemangioendotheliomas, which subsided gradually after introduction of a lactose-free formula. Only one patient from this cohort was offered expanded metabolic screening at birth. She was not ascertained by conducted newborn screening and was diagnosed upon presentation with cholestatic jaundice by 1 month of age. CONCLUSION: This is the first report of the clinical and molecular characterization of a large cohort of patients with citrin deficiency in Hong Kong. The presentation of this cohort of patients expands the clinical phenotypic spectrum of NICCD. Benign liver tumors such as hemangioendotheliomas may be associated with citrin deficiency in addition to the well-known association with hepatocellular carcinoma. Citrin deficiency may manifest in later infancy period with an NICCD-like phenotype. Furthermore, this condition is not always ascertained by expanded newborn metabolic screening testing.

12.
Aliment Pharmacol Ther ; 47(1): 114-122, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29023803

RESUMO

BACKGROUND: Hepatitis B e antigen (HBeAg) seroconversion is a treatment endpoint for HBeAg-positive CHB, and a necessary precursor to HBsAg loss. Biomarkers that predict serological outcomes would be useful. AIM: To evaluate the utility of measuring HBeAg levels for predicting HBeAg seroconversion and HBsAg loss under long-term tenofovir (TDF) therapy. METHODS: A total of 266 patients were enrolled into a phase III study of TDF vs adefovir (ADV) for 48 weeks in HBeAg-positive patients, followed by open-label TDF up to 384 weeks. Serum HBeAg levels were measured for subjects with samples available at both baseline and week 24 of treatment (n = 200). Analysis compared subjects who achieved HBeAg seroconversion by week 384 vs no HBeAg seroconversion. RESULTS: HBeAg seroconversion rate was 52% by week 384. Time to HBeAg seroconversion was 80 weeks (IQR: 36-162). HBeAg decline at week 24 was associated with HBeAg seroconversion (1.63 vs 0.90 log10 PEIU/mL, P = .002). The optimal threshold for identifying HBeAg seroconversion was HBeAg decline ≥2.2 log10 PEIU/mL at week 24, with HBeAg seroconversion achieved by 76% of patients, compared to 44% if HBeAg decline <2.2 log10 (P < .0001). HBeAg decline ≥2.2 log10 PEIU/mL at week 24 was associated with HBsAg loss in genotype A or D patients (38% vs 15%, P = .03). Precore/basal core promotor variants were associated with lower baseline HBeAg levels, but not HBeAg seroconversion. CONCLUSION: Decline in HBeAg levels by week 24 was associated with HBeAg seroconversion and HBsAg loss in HBeAg-positive chronic hepatitis B patients treated with long-term TDF.


Assuntos
Antivirais/uso terapêutico , Antígenos E da Hepatite B/sangue , Hepatite B Crônica/tratamento farmacológico , Tenofovir/uso terapêutico , Adenina/análogos & derivados , Adenina/uso terapêutico , Adulto , Biomarcadores/sangue , Método Duplo-Cego , Feminino , Antígenos de Superfície da Hepatite B/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Organofosfonatos/uso terapêutico , Resultado do Tratamento , Adulto Jovem
13.
Hong Kong Med J ; 23(6): 586-93, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29123073

RESUMO

INTRODUCTION: A survey conducted during 2005 to 2007 by the Centre for Food Safety in Hong Kong suggested that only 5% of the local population had a sufficient dietary intake of iodine. The study, however, was limited as biochemical data (ie urinary iodine concentration) were lacking. Pregnant women are vulnerable to iodine deficiency because of their increased requirement. Recent studies have shown that iodine deficiency in early pregnancy is associated with poorer cognitive development in early childhood. This study reports the iodine status of women during early gestation at an obstetric unit in Hong Kong. METHODS: Healthy pregnant women with no history of hyperemesis gravidarum were enrolled into a study when they first made a booking in an antenatal clinic of a public hospital to investigate their iodine status during early pregnancy. All subjects were asked to collect their morning urine for measurement of iodine and creatinine levels. Daily dietary intake of iodine was assessed in a subgroup of participants by structured interview using a standard food frequency questionnaire. RESULTS: A total of 600 pregnant women were enrolled at a median of 7.0 weeks of gestation. The median urinary iodine concentration and urinary iodine-to-creatinine ratio were 100 µg/L and 98 µg/g, respectively; 429 (71.5%) participants had iodine insufficiency according to the World Health Organization classification. Daily dietary intake of iodine was assessed in 146 participants. The median daily intake of iodine was 69.5 µg and 122 (83.6%) participants had an intake below the 250 µg recommended during pregnancy by the World Health Organization. CONCLUSIONS: Local pregnant women continue to have an inadequate dietary intake of iodine and remain iodine-deficient.


Assuntos
Alimentos Fortificados , Iodo/deficiência , Complicações na Gravidez/epidemiologia , Adulto , Feminino , Hong Kong/epidemiologia , Humanos , Iodo/administração & dosagem , Serviços de Saúde Materna , Gravidez , Complicações na Gravidez/prevenção & controle , Complicações na Gravidez/urina , Cuidado Pré-Natal
14.
J Reprod Immunol ; 120: 27-33, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28432903

RESUMO

Preeclampsia is a devastating complication of pregnancy characterized by late-gestation hypertension and proteinuria. Because the only definitive treatment is delivery of the fetus and placenta, preeclampsia contributes to increased morbidity and mortality of both mother and fetus. The BPH/5 mouse model, which spontaneously develops a syndrome strikingly similar to preeclampsia, displays excessive inflammation and suppression of inflammation improves pregnancy outcomes. During early pregnancy, decidual macrophages play an important role in promoting maternal tolerance to fetal antigens and regulating tissue remodeling, two functions that are critical for normal placental development. BPH/5 pregnancies are characterized by abnormal placentation; therefore, we hypothesized that macrophage localization and/or function is altered during early pregnancy at the site of placental formation (the decidua) compared to C57BL/6 controls. At early gestation time points, before the onset of maternal hypertension or proteinuria, there was a reduction in the number of macrophages in BPH/5 decidua and a concomitant increase in activated T cells compared with C57BL/6. BPH/5 decidua also exhibited decreased expression of the immunosuppressive cytokine, IL-10, and increased expression of pro-inflammatory, inducible nitric oxide synthase. Together, these data suggest that a reduction in decidual macrophages during pregnancy is associated with immune activation in BPH/5 mice, inadequate placental development and may contribute to adverse pregnancy outcomes in this model.


Assuntos
Decídua/imunologia , Inflamação/imunologia , Macrófagos/imunologia , Pré-Eclâmpsia/imunologia , Linfócitos T/imunologia , Animais , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Idade Gestacional , Humanos , Mediadores da Inflamação/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Placentação , Gravidez
15.
Psychooncology ; 26(6): 856-861, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27479290

RESUMO

BACKGROUND: Patients with cancer and their spouses usually both suffer, but the dyadic effects have not been thoroughly investigated. This study examined the dyadic effects of psychological distress on sleep disturbance in Chinese couples affected by cancer. METHODS: Patients with cancer and their spouses (N = 135) participated in this study. The Hospital Anxiety and Depression Scale and Pittsburgh Sleep Quality Index were used to measure anxiety, depression, and sleep disturbance. RESULTS: There were significant patient-spouse associations on anxiety (r = 0.48, P < .01), depression (r = 0.55, P < .01), and sleep disturbance (r = 0.30, P < .01). Analyses using the actor-partner interdependence model showed that anxiety had significant actor effects, rather than partner effects, on sleep disturbance in both patients and their spouses, but depression had both actor and partner effects. In addition to providing evidence for the concordance in distress and sleep disturbance in patients with cancer and their spouses, the findings indicate a mutual influence of depression on sleep disturbance among the couples. CONCLUSIONS: Clinicians and health care providers are suggested to integrate depression management as a component of sleep therapies and involve both patients and their spouses in treatment programs.


Assuntos
Relações Interpessoais , Neoplasias/psicologia , Transtornos do Sono-Vigília/psicologia , Cônjuges/psicologia , Estresse Psicológico/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ansiedade/psicologia , China , Depressão/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/terapia , Cônjuges/estatística & dados numéricos
16.
J Virol ; 90(16): 7171-7183, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27252524

RESUMO

UNLABELLED: Chronic hepatitis B (CHB) is prevalent worldwide. The infectious agent, hepatitis B virus (HBV), replicates via an RNA intermediate and is error prone, leading to the rapid generation of closely related but not identical viral variants, including those that can escape host immune responses and antiviral treatments. The complexity of CHB can be further enhanced by the presence of HBV variants with large deletions in the genome generated via splicing (spHBV variants). Although spHBV variants are incapable of autonomous replication, their replication is rescued by wild-type HBV. spHBV variants have been shown to enhance wild-type virus replication, and their prevalence increases with liver disease progression. Single-molecule deep sequencing was performed on whole HBV genomes extracted from samples, including the liver explant, longitudinally collected from a subject with CHB over a 15-year period after liver transplantation. By employing novel bioinformatics methods, this analysis showed that the dynamics of the viral population across a period of changing treatment regimens was complex. The spHBV variants detected in the liver explant remained present posttransplantation, and a highly diverse novel spHBV population as well as variants with multiple deletions in the pre-S genes emerged. The identification of novel mutations outside the HBV reverse transcriptase gene that co-occurred with known drug resistance-associated mutations highlights the relevance of using full-genome deep sequencing and supports the hypothesis that drug resistance involves interactions across the full length of the HBV genome. IMPORTANCE: Single-molecule sequencing allowed the characterization, in unprecedented detail, of the evolution of HBV populations and offered unique insights into the dynamics of defective and spHBV variants following liver transplantation and complex treatment regimens. This analysis also showed the rapid adaptation of HBV populations to treatment regimens with evolving drug resistance phenotypes and evidence of purifying selection across the whole genome. Finally, the new open-source bioinformatics tools with the capacity to easily identify potential spliced variants from deep sequencing data are freely available.


Assuntos
Variação Genética/genética , Genoma Viral/genética , Vírus da Hepatite B/genética , Hepatite B Crônica/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Cirrose Hepática/cirurgia , Transplante de Fígado , Idoso , Antivirais/uso terapêutico , Biologia Computacional , DNA Viral/genética , Farmacorresistência Viral/genética , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/complicações , Hepatite B Crônica/virologia , Humanos , Cirrose Hepática/virologia , Masculino , Replicação Viral
17.
J Med Virol ; 86(4): 695-706, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24497078

RESUMO

Indigenous Australians experience a significant health burden from chronic hepatitis B infection; however, the strain of hepatitis B virus (HBV) found among Indigenous Australians has not been well characterized. Blood samples were collected from 65 Indigenous Australians with chronic HBV infection from across the Top End of Australia's Northern Territory. Phylogenetic analysis of HBV from these samples revealed that 100% of the isolates were genotype C, sub-genotype C4, expressing the serotype ayw3. This strain is a divergent group within the HBV/C genotype, and has only been described in Indigenous Australians. Evidence of recombination was suggested by discordant phylogenetic clustering of the C4 sequences when comparing the full genome to the surface region and confirmed by recombination analysis which showed the surface gene region to be most closely related to genotype J, while the remaining regions of the genome were most similar to genotype C sequences. Mutational analysis revealed the presence of multiple mutations that have been linked with more rapid liver disease progression and an increased risk of hepatocellular carcinoma. These mutations were detected in the majority of sequences examined. Variants associated with vaccine failure were detected as the predominant viral quasi-species in 3/35 samples. In summary, the HBV C4 variant found in this population has a high potential to cause advanced liver disease and to escape vaccination programs. Further in vitro functional and natural history studies are warranted in order to determine the clinical and public health consequences of infection with the HBV C4 variant in these communities.


Assuntos
Genoma Viral/genética , Vírus da Hepatite B/genética , Hepatite B Crônica/sangue , Hepatite B Crônica/epidemiologia , Sequência de Aminoácidos , Austrália/epidemiologia , Sequência de Bases , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/virologia , Análise Mutacional de DNA , DNA Viral/genética , Variação Genética , Genótipo , Antígenos E da Hepatite B/imunologia , Vírus da Hepatite B/classificação , Hepatite B Crônica/virologia , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/virologia , Dados de Sequência Molecular , Mutação , Filogeografia , Grupos Populacionais , Alinhamento de Sequência , Análise de Sequência de DNA
18.
J Viral Hepat ; 21(11): 809-17, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24329944

RESUMO

This study sought to assess the antiviral efficacy of lamivudine (LMV) administered during third trimester to reduce maternal viraemia and to identify the emergence of LMV resistance. A prospective observational analysis was performed on 26 mothers with high viral load (>107 IU/mL). Twenty-one women received LMV (treated group) for an average of 53 days (range 22-88 days), and the remaining five formed the untreated control group. Serum samples from two time points were used to measure HBV DNA levels and antiviral drug resistance. The LMV-treated women achieved a median HBV DNA reduction of 2.6-log10 IU/mL. Although end-of-treatment (EOT) HBV DNA in four (18%) LMV-treated women remained at >10(7) IU/mL (± 0.5 log IU/mL), no mother-to-baby transmission was observed. In contrast, a baby from the untreated mother was HBsAg positive at 9 months postpartum. Four technologies were used for drug resistance testing. Only ultra-deep pyrosequencing (UDPS) was sufficiently sensitive to detect minor viral variants down to <1%. UDPS showed that LMV therapy resulted in increased viral quasispecies diversity and positive selection of HBV variants with reverse transcriptase amino acid substitutions at sites associated with primary LMV resistance (rtM204I/V and rtA181T) in four (19%) women. These viral variants were detected mostly at low frequencies (0.63-5.92%) at EOT, but one LMV-treated mother had an rtA181T variant that increased from 2.2% pretherapy to 25.59% at EOT. This mother was also infected with the vaccine escape variant (sG145R), which was inhibited by LMV treatment. LMV therapy during late pregnancy only reduced maternal viraemia moderately, and drug-resistant viral variants emerged.


Assuntos
Antivirais/uso terapêutico , Farmacorresistência Viral , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B/tratamento farmacológico , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Lamivudina/uso terapêutico , Complicações Infecciosas na Gravidez/tratamento farmacológico , Sangue/virologia , DNA Viral/genética , DNA Viral/isolamento & purificação , Feminino , Variação Genética , Hepatite B/prevenção & controle , Hepatite B/virologia , Vírus da Hepatite B/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Recém-Nascido , Mutação , Gravidez , Complicações Infecciosas na Gravidez/virologia , Estudos Prospectivos , Seleção Genética , Resultado do Tratamento , Carga Viral
19.
Am J Respir Cell Mol Biol ; 50(2): 419-28, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24053134

RESUMO

Endogenous glucocorticoid (GC) hormones, signaling via the GC receptor (GR), are essential for normal lung development, and synthetic GCs are routinely used to treat respiratory disorders of very preterm babies. Germline GR knockout (GR(-/-)) mice show immature lung morphology and severe lung cellular hyperplasia during embryogenesis and die at birth due to respiratory failure. Two recent studies have reported contradictory results regarding the necessity for GR expression in specific lung germ layers during respiratory maturation. We further investigate in detail the lung phenotype in mice with a conditional deletion of GR in the endothelium, mesenchyme, and lung epithelium. We show that loss of GR in the mesenchyme alone produces a retarded lung phenotype almost identical to that of germline GR(-/-) mice, including severe postnatal lethality and lung cell hyperplasia. Loss of GR in lung epithelial cells and the endothelium had no gross effect on survival or lung morphology, but loss of epithelial GR caused increased cell proliferation in multiple compartments. Mesenchymal GR loss also produced increased epithelial cell proliferation, implying the existence of GC-regulated germ layer cross-talk. Protein levels of GR-mediated cell cycle regulators, including the cyclin-dependent kinase inhibitor p21(CIP1) and the growth factor midkine, were unaffected by mesenchymal GR deletion, yet expression of the extracellular matrix proteoglycan versican was up-regulated in the distal lung on loss of mesenchymal GR. These results show that GR-mediated signaling from the mesenchyme regulates respiratory maturation and ultimately survival at birth and that a key GR-repressed transcriptional target in lung mesenchymal cells is versican.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Glucocorticoides/metabolismo , Pulmão/citologia , Mesoderma/citologia , Receptores de Glucocorticoides/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citocinas/farmacologia , Modelos Animais de Doenças , Epitélio/metabolismo , Glucocorticoides/genética , Pulmão/metabolismo , Mesoderma/metabolismo , Camundongos , Camundongos Transgênicos , Midkina , Receptores de Glucocorticoides/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
20.
J Med Virol ; 82(9): 1481-8, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20648600

RESUMO

This study analyzed the genotype distribution and frequency of lamivudine (LAM) and tenofovir (TDF) resistance mutations in a group of patients co-infected with HIV and hepatitis B virus (HBV). A cross-sectional study of 847 patients with HIV was conducted. Patients provided blood samples for HBsAg detection. The load of HBV was determined using an "in-house" real-time polymerase chain reaction. HBV genotypes/subgenotypes, antiviral resistance, basal core promoter (BCP), and precore mutations were detected by DNA sequencing. Twenty-eight patients with co-infection were identified. The distribution of HBV genotypes among these patients was A (n = 9; 50%), D (n = 4; 22.2%), G (n = 3; 16.7%), and F (n = 2; 11.1%). Eighteen patients were treated with LAM and six patients were treated with LAM plus TDF. The length of exposure to LAM and TDF varied from 4 to 216 months. LAM resistance substitutions (rtL180M + rtM204V) were detected in 10 (50%) of the 20 patients with viremia. This pattern and an accompanying rtV173L mutation was found in four patients. Three patients with the triple polymerase substitution pattern (rtV173L + rtL180M + rtM204V) had associated changes in the envelope gene (sE164D + sI195M). Mutations in the BCP region (A1762T, G1764A) and in the precore region (G1896A, G1899A) were also found. No putative TDF resistance substitution was detected. The data suggest that prolonged LAM use is associated with the emergence of particular changes in the HBV genome, including substitutions that may elicit a vaccine escape phenotype. No putative TDF resistance change was detected after prolonged use of TDF.


Assuntos
Fármacos Anti-HIV/farmacologia , Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico , Vírus da Hepatite B/genética , Hepatite B/virologia , Lamivudina/farmacologia , Adenina/análogos & derivados , Adenina/farmacologia , Adenina/uso terapêutico , Adulto , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Brasil/epidemiologia , Comorbidade , Estudos Transversais , DNA Polimerase Dirigida por DNA/genética , Feminino , Hepatite B/epidemiologia , Vírus da Hepatite B/efeitos dos fármacos , Humanos , Lamivudina/uso terapêutico , Masculino , Mutação , Organofosfonatos/farmacologia , Organofosfonatos/uso terapêutico , Tenofovir , Proteínas do Core Viral/genética , Carga Viral , Proteínas Virais/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA