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1.
J Virus Erad ; 7(3): 100053, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34621530

RESUMO

HIV-1 is able to persist in the face of potent antiretroviral therapy (ART). A number of strategies are being explored to allow ART-free viral remission or viral eradication. In order to gauge the progress of these strategies, assays with which to measure viral reservoir size and activity are needed. In a large percentage of aviremic individuals on suppressive ART, viral transcripts can be detected in peripheral blood CD4+ T cells. While this cell-associated RNA has been considered as a marker of viral reservoir activity, it is unclear whether cell-associated viral transcripts in aviremic individuals originate from biologically competent proviruses as opposed to being a product of abortive transcription from defective proviruses. We assessed whether cell-associated viral RNA in peripheral blood CD4+ T cells from aviremic individuals on ART originated from biologically competent proviruses. We demonstrate that cell-associated viral RNA transcripts were highly related to viral sequences obtained by ex vivo outgrowth. This relationship was also observed when viral transcription in the outgrowth cultures was limited to donor CD4+ T cells. Our study indicates that cell-associated viral RNA warrants further consideration as a viral reservoir surrogate in individuals on suppressive ART.

2.
Infect Genet Evol ; 51: 194-197, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28392467

RESUMO

HIV cure research is increasingly focused on anatomical tissues as sites for residual HIV replication during combined antiretroviral therapy (cART). Tissue-based HIV could contribute to low-level immune activation and viral rebound over the course of infection and could also influence the development of diseases, such as atherosclerosis, neurological disorders and cancers. cART-treated subjects have a decreased and irregular presence of HIV among tissues, which has resulted in a paucity of actual evidence concerning how or if HIV persists, replicates and evolves in various anatomical sites during therapy. In this study, we pooled 1806 HIV envelope V3 loop sequences from twenty-six tissue types (seventy-one total tissues) of six pre-cART subjects, four subjects with an unknown cART history who died with profound AIDS, and five subjects who died while on cART with an undetectable plasma viral load. A computational approach was used to assess sequences for their ability to utilize specific cellular coreceptors (R5, R5 and X4, or X4). We found that autopsied tissues obtained from virally suppressed cART+ subjects harbored both integrated and expressed viruses with similar coreceptor usage profiles to subjects with no or ineffective cART therapy (i.e., significant plasma viral load at death). The study suggests that tissue microenvironments provide a sanctuary for the continued evolution of HIV despite cART.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Microambiente Celular/imunologia , Infecções por HIV/imunologia , Evasão da Resposta Imune , Neoplasias/imunologia , Receptores CCR5/genética , Receptores CXCR4/genética , Terapia Antirretroviral de Alta Atividade , Autopsia , Biologia Computacional , Feminino , Expressão Gênica , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções por HIV/patologia , HIV-1/genética , HIV-1/crescimento & desenvolvimento , HIV-1/imunologia , Humanos , Masculino , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Receptores CCR5/imunologia , Receptores CXCR4/imunologia , Análise de Sequência de RNA , Carga Viral/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
3.
J Viral Hepat ; 24(7): 551-560, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28092412

RESUMO

The extensive genetic heterogeneity of hepatitis C virus (HCV) requires in-depth understanding of the population dynamics of different viral subtypes for more effective control of epidemic outbreaks. We analysed HCV sequences data from 125 participants in Wuhan, China. These participants were newly infected by subtype 1b (n=13), 3a (n=15), 3b (n=50) and 6a (n=39) while on methadone maintenance treatment (MMT). Bayesian phylogenies and demographic histories were inferred for these subtypes. Participants infected with HCV-1b and 3a were clustered in well-supported monophyletic clades, indicating local subepidemics. Subtypes 3b and 6a strains were intermixed with other Chinese isolates, as well as isolates from other Asian countries, reflecting ongoing across geographic boundary transmissions. Subtypes 1b and 3a declined continuously during the past ten years, consistent with the health and economic reform in China, while subtype 3b showed ongoing exponential growth and 6a was characterized by several epidemic waves, possibly related to the recently growing number of travellers between China and other Asian countries. In conclusion, results of this study suggest that HCV subtype 3b and 6a subepidemics in China are currently not under control, and new epidemic waves may emerge given the rapid increase in international travelling following substantial economic growth.


Assuntos
Analgésicos Opioides/administração & dosagem , Hepacivirus/classificação , Hepatite C/virologia , Metadona/administração & dosagem , Tratamento de Substituição de Opiáceos/métodos , Dinâmica Populacional , Abuso de Substâncias por Via Intravenosa/tratamento farmacológico , Adulto , China/epidemiologia , Feminino , Genótipo , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C/complicações , Hepatite C/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Filogenia , Abuso de Substâncias por Via Intravenosa/complicações
4.
Clin Exp Med ; 16(2): 213-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-25773165

RESUMO

Hereditary angioedema (HAE) is a rare autosomal dominant disorder, due to C1-inhibitor deficiency, which causes episodic swellings of subcutaneous tissues, bowel walls and upper airways which are disabling and potentially life-threatening. We evaluated n = 17 patients with confirmed HAE diagnosis in basal and crisis state and n = 19 healthy subjects. The samples were tested for IL-17, FGFb, G-CSF and GM-CSF, using Bio-plex kit. Data analysis was performed via nonparametric Spearman's correlations and two sets of linear mixed models. When comparing HAE subjects during basal and crisis states, we found out significantly (i.e., p value <0.05) higher values in crisis states rather than in basal states for the three growth factors and cytokine IL-17. When comparing healthy subjects versus HAE patients at basal state, we found out significantly higher values in HAE subjects only for GM-CSF, FGFb and IL-17, but not for G-CSF. In HAE patients, there is a connection between IL-17 and growth factors. The low-grade inflammation in absence of attacks is demonstrated by constant higher amount of IL-17, FGFb and GM-CSF with respect to healthy patients. This could indicate that in this disease there is a level of activation that maintains the system in a "tick-over state," that can be activate by several stimuli that are able to induce a increase in inflammatory mediators during the acute attack.


Assuntos
Angioedemas Hereditários/patologia , Peptídeos e Proteínas de Sinalização Intercelular/análise , Interleucina-17/análise , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
Andrologia ; 48(4): 380-8, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26259725

RESUMO

Changes in seminal fluid viscosity (SFV), reactive oxygen species (ROS) production, cytokines and seminal leucocyte concentration related to microbiological outcome in patients with chronic bacterial prostatitis (CBP) were studied. One hundred and ten infertile patients with CBP (positive sperm culture ≥10(5) colony-forming units [CFU] ml(-1), pathogens or Chlamydia in expressed prostatic secretions) were treated with levofloxacin 500 mg daily for 14 consecutive days per month for 3 months. In case of bacterial prostatitis, two conditions were examined: responders, eradication of 0 to <10(3) CFU ml(-1) (n = 78) and poor responders, >10(3) to <10(5) CFU ml(-1) (n = 32). Compared with poor responders, responders showed a significant increase of sperm progressive motility and a significant decrease in seminal leucocyte count, SFV, liquefaction time, ROS production (in all fractions and conditions), seminal tumour necrosis factor-α and interleukin 6. None of these variables showed significant differences compared with a control group of 37 fertile men. On the other hand, the poor responders showed significant changes in these variables compared with matched pretreatment values. In patients with CBP, antibiotic therapy alone leads to eradication in ≈71%, with improvement of sperm progressive motility, SFV and the framework of prooxidative factors. However, in the remaining ≈29% with poor antibiotic responsiveness, a deterioration of all variables is observed.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Levofloxacino/uso terapêutico , Prostatite/tratamento farmacológico , Sêmen/química , Adulto , Antibacterianos/administração & dosagem , Infecções Bacterianas/complicações , Infecções Bacterianas/microbiologia , Chlamydia , Doença Crônica , Humanos , Infertilidade Masculina/tratamento farmacológico , Infertilidade Masculina/etiologia , Interleucina-6/análise , Itália , Contagem de Leucócitos , Levofloxacino/administração & dosagem , Masculino , Prostatite/complicações , Prostatite/microbiologia , Espécies Reativas de Oxigênio/metabolismo , Sêmen/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Resultado do Tratamento , Fator de Necrose Tumoral alfa/análise , Viscosidade , Adulto Jovem
6.
Cell Mol Biol (Noisy-le-grand) ; 61(5): 49-51, 2015 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-26475388

RESUMO

In the present study, we analysed a 31bp variable number of tandem repeats (VNTR) of the cystathionine ß-synthase (CBS) gene in 427 subjects: 127 patients with Down syndrome (DS) and in 60 of their mothers; 172 age-and sex-matched controls and in 68 of their mothers. A significant statistical difference in the distribution of the 21 repeat allele was found comparing mothers of subjects with DS versus mothers of children without DS (χ2= 4.166; P = 0.0413; Table 2). Since CBS 21 repeats allele carriers show a decrease of CBS enzyme activity possibly leading to lower intracellular glutathione concentration, these results could be explained by a higher not disjunction probability of chromosome 21 in oocytes, due to poor antioxidative protection against reactive oxygen species (ROS) toxic activity.


Assuntos
Cistationina beta-Sintase/genética , Síndrome de Down/genética , Repetições Minissatélites/genética , Adulto , Idoso , Alelos , Cromossomos Humanos Par 21/genética , Feminino , Frequência do Gene/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mães , Espécies Reativas de Oxigênio/metabolismo , Fatores de Risco
8.
Nutr Metab Cardiovasc Dis ; 24(5): 511-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24582685

RESUMO

BACKGROUND AND AIMS: Carotid intima-media thickness (IMT) and arterial stiffness parameters, including aortic augmentation index (AIx) and pulse wave velocity (PWV), are independent predictors of stroke and cardiovascular disease. Genetic effects on these traits were never explored in a Mediterranean country. The present study aims to quantify the contribution of genes, environment and age to carotid IMT and aortic Aix and PWV. METHODS AND RESULTS: The twin design was used. A total of 348 adult twins from the Italian Twin Register underwent measurements of carotid IMT and aortic PWV and AIx in three university hospitals located in Rome, Padua and Perugia. Carotid IMT was measured by B-mode ultrasound, aortic PWV and AIx by Arteriograph. Genetic modelling was performed to decompose total variance of traits into genetic, shared and unshared environmental and age components. For each phenotype, the best-fitting model included additive genetic, unshared environmental and age effects. For IMT, heritability was 0.32 (95% confidence interval (CI): 0.25-0.38), unshared environmental component was 0.25 (0.18-0.32) and age contribution was 0.44 (0.39-0.49). For AIx and PWV, heritabilities were 0.42 (0.29-0.55) and 0.49 (0.35-0.62), unshared environmental components were 0.31 (0.22-0.44) and 0.37 (0.26-0.51) and age contributions were 0.27 (0.16-0.39) and 0.14 (0.06-0.24), respectively. CONCLUSION: This study shows substantial genetic and unshared environmental influences on carotid intima-media thickness and arterial stiffness and confirms the relevant role of age in the aetiology of these traits. Further support is provided for prevention and health promotion strategies based on modifiable factors.


Assuntos
Espessura Intima-Media Carotídea , Interação Gene-Ambiente , Rigidez Vascular/genética , Adulto , Idoso , Aorta/metabolismo , Índice de Massa Corporal , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/genética , Artéria Carótida Primitiva/diagnóstico por imagem , Feminino , Predisposição Genética para Doença , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Análise de Onda de Pulso , Fatores de Risco
9.
Andrologia ; 46(10): 1148-55, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24329571

RESUMO

Changes in levels of oxidative damage products in semen and their relationship to seminal fluid viscosity (SFV) have recently received increasing research interest. We analysed whether SFV was associated with ROS generation, levels of cytokines TNF-alpha (TNF-α), IL-6 and IL-10 and seminal leucocyte concentration, and whether ROS production was related to the extent of infections/inflammations at one (prostatitis) or two (prostato-vesiculitis) male accessory glands. We studied 169 infertile patients, with chronic bacterial prostatitis (PR, n = 74) and/or bilateral prostato-vesiculitis (PV, n = 95), as diagnosed by the ultrasound (US) criteria. Healthy fertile men (n = 42) served as controls. In the PV patient group, SFV, semen characteristics and ROS production had median values that were significantly higher than those found in PR patients and controls, although other sperm variables had values significantly lower than those found in PR patients or controls. In PV infertile patients, ROS generation and pro-inflammatory cytokines levels were higher than those found in PR infertile patients and controls, although seminal IL-10 levels in PV and PR patients were lower than those found in the controls. In PR patients, the levels of SFV were positively related to TNF-α (r = 0.67; P < 0.01), fMLP-stimulated ROS production in the 45% Percoll fraction (r = 0.687, P < 0.01) and the 90% Percoll fraction in basal condition (r = 0.695, P < 0.01), and after fMLP-stimulation (r = 0.688, P < 0.01). Thus, our data indicated that seminal hyperviscosity is associated with increased oxidative stress in infertile men and increased pro-inflammatory interleukins in patients with male accessory gland infection, more when the infection was extended to the seminal vesicles.


Assuntos
Infertilidade Masculina/metabolismo , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Prostatite/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sêmen/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Humanos , Infertilidade Masculina/patologia , Leucócitos/metabolismo , Masculino , Estresse Oxidativo/fisiologia , Glândulas Seminais/metabolismo , Glândulas Seminais/patologia , Contagem de Espermatozoides , Viscosidade
11.
São Paulo; SMS; 18 jul. 2013. 1 p. map, tab.
Não convencional em Português | Coleciona SUS, COVISA-Producao, Sec. Munic. Saúde SP, Sec. Munic. Saúde SP | ID: biblio-940618
12.
Eur J Histochem ; 57(2): e13, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23807292

RESUMO

A genetic background has been implicated in the development of prostate cancer. Protein microarrays have enabled the identification of proteins, some of which associated with apoptosis, that may play a role in the development of such a tumor. Inhibition of apoptosis is a co-factor that contributes to the onset and progression of prostate cancer, though the molecular mechanisms are not entirely understood. Poly (ADP-ribose) polymerase 1 (PARP-1) gene is required for translocation of the apoptosis-inducing factor (AIF) from the mitochondria to the nucleus. Hence, it is involved in programmed cell death. Different PARP-1 gene expression has been observed in various tumors such as glioblastoma, lung, ovarian, endometrial, and skin cancers. We evaluated the expression of PARP-1 protein in prostatic cancer and normal prostate tissues by immunohistochemistry in 40 men with prostate cancer and in 37 normal men. Positive nuclear PARP-1 staining was found in all samples (normal prostate and prostate cancer tissues). No cytoplasmic staining was observed in any sample. PARP-1-positive cells resulted significantly higher in patients with prostate carcinoma compared with controls (P<0.001). PARP-1 over-expression in prostate cancer tissue compared with normal prostate suggests a greater activity of PARP-1 in these tumors. These findings suggest that PARP-1 expression in prostate cancer is an attempt to trigger apoptosis in this type of tumor similarly to what reported in other cancers.


Assuntos
Regulação Enzimológica da Expressão Gênica , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Próstata/enzimologia , Neoplasias da Próstata/enzimologia , Idoso , Idoso de 80 Anos ou mais , Apoptose , Carcinoma/enzimologia , Carcinoma/patologia , Núcleo Celular/enzimologia , Citoplasma/enzimologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Poli(ADP-Ribose) Polimerase-1 , Neoplasias da Próstata/patologia
13.
Eur J Histochem ; 56(1): e9, 2012 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-22472897

RESUMO

One of the most common type of primary brain tumors in adults is the glioblastoma multiforme (GBM) (World Health Organization grade IV astrocytoma). It is the most common malignant and aggressive form of glioma and it is among the most lethal ones. Poly (ADP-ribose) polymerase 1 (PARP-1) gene, located to 1q42, plays an important role for the efficient maintenance of genome integrity. PARP-1 protein is required for the apoptosis-inducing factor (AIF) translocation from the mitochondria to the nucleus. PARP-1 is proteolytically cleaved at the onset of apoptosis by caspase-3. Microarray analysis of PARP-1 gene expression in more than 8,000 samples revealed that PARP-1 is more highly expressed in several types of cancer compared with the equivalent normal tissues. Overall, the most differences in PARP-1 gene expression have been observed in breast, ovarian, endometrial, lung, and skin cancers, and non-Hodgkin's lymphoma. We evaluated the expression of PARP-1 protein in normal brain tissues and primary GBM by immunohistochemistry. Positive nuclear PARP-1 staining was found in all samples with GBM, but not in normal neurons from controls (n=4) and GBM patients (n=27). No cytoplasmic staining was observed in any sample. In conclusion, PARP-1 gene is expressed in GBM. This finding may be envisioned as an attempt to trigger apoptosis in this tumor, as well as in many other malignancies. The presence of the protein exclusively at the nucleus further support the function played by this gene in genome integrity maintenance and apoptosis. Finally, PARP-1 staining may be used as GBM cell marker.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias Encefálicas/enzimologia , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioblastoma/enzimologia , Proteínas de Neoplasias/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Poli(ADP-Ribose) Polimerases/biossíntese , Adulto , Idoso , Apoptose , Encéfalo/enzimologia , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Núcleo Celular/enzimologia , Núcleo Celular/patologia , Feminino , Perfilação da Expressão Gênica , Glioblastoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Poli(ADP-Ribose) Polimerase-1
14.
J Endocrinol Invest ; 35(1): 5-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22391137

RESUMO

The most frequent defect of the male urogenital tract at birth is cryptorchidism. Cryptorchidism causes primitive testicular pathology responsible for infertility. Men with Down's syndrome (DS) have an increased risk of cryptorchidism. The spermatid perinuclear RNA-binding protein (STRBP) gene codifies a microtubule-associated RNA-binding protein and it is highly expressed in the testis as well as in the brain. At both levels, this gene seems to play a relevant role in the regular development of these organs. These observations prompted us to evaluate the expression of STRBP mRNA in 5 DS men with cryptorchidism and 5 normal healthy men (controls) by quantitative Real Time PCR in peripheral blood leukocytes. We found a decreased expression of the STRBP gene in men with DS and cryptorchidism compared with controls. This finding suggests that the impaired expression of this gene in DS may play a pathogenetic role in the altered brain and testicular development in subjects with DS and cryptorchidism.


Assuntos
Criptorquidismo/genética , Síndrome de Down/genética , Proteínas Associadas aos Microtúbulos/genética , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Testículo/metabolismo , Adulto , Estudos de Casos e Controles , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Andrologia ; 44 Suppl 1: 556-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21919943

RESUMO

The aim of this study was to evaluate whether the viscosity of semen in patients with male accessory gland infection is related to the extension of the inflammatory process to the various glands. To achieve this, viscosity was assessed by quantitative viscosimeter and the results were expressed in centipoise (cps). The study was conducted on 30 infertile patients with clinical evidence of male accessory gland infection and a mean age of 29.0 ± 4.0 years. Their semen viscosity was evaluated through quantitative viscometer. All patients showed an increase of viscosity evaluated according to WHO criteria, while this parameter was normal in all controls. Semen viscosity of patients with male accessory gland infection (28.6 ± 2.2 cps) was significantly (P < 0.05) higher than that in the controls (10.7 ± 0.6 cps). Significantly increasing values were observed in patients with involvement of multiple gland inflammation (prostatitis

Assuntos
Genitália Masculina/fisiopatologia , Infecções/fisiopatologia , Sêmen , Adulto , Humanos , Masculino
16.
Andrologia ; 44 Suppl 1: 565-70, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21919944

RESUMO

The aim of this study was to evaluate the level of malondialdehyde (MDA) (one of the final products of lipid peroxidation and well-known marker of oxidative stress) in semen of infertile men with type 2 diabetes and to investigate its relationship with their glycaemic control. Forty infertile men with type 2 diabetes were evaluated. The mean ages were 36.5 ± 8.0. Men with diabetes were divided into two groups. Group A (n = 20) with glycated haemoglobin >10% and group B (n = 20) with glycated haemoglobin <7%. A single sample was examined according to the criteria of the World Health Organization (WHO Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Interaction, 1999, Cambridge University Press). MDA was assessed using the thiobarbituric acid method. MDA concentration in semen of group A patients (0.95 ± 0.35 nmol ml(-1)) was significantly higher than in group B patients (0.43 ± 0.13 nmol ml(-1)) (P value < 0.05) and had negative relationship with sperm density (r = -.717; P value < 0.05), total sperm count (r = -.625; P value < 0.05), progressive motility (r = -.489; P value < 0.05) and normal forms (r = -.545; P value < 0.05). Based on these results, it could be concluded that increase in lipid peroxidation in men with diabetes with poor metabolic control was associated with low sperm quality.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Peroxidação de Lipídeos , Sêmen/metabolismo , Adulto , Estudos de Casos e Controles , Humanos , Infertilidade Masculina/metabolismo , Masculino
17.
Methods Ecol Evol ; 2(5): 437-445, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22121470

RESUMO

Nucleotide sequences sampled at different times (serially-sampled sequences) allow researchers to study the rate of evolutionary change and the demographic history of populations. Some phylogenies inferred from serially-sampled sequences are described as having strong 'temporal clustering', such that sequences from the same sampling time tend to to cluster together and to be the direct ancestors of sequences from the following sampling time. The degree to which phylogenies exhibit these properties is thought to reflect interesting biological processes, such as positive selection or deviation from the molecular clock hypothesis.Here we introduce the Temporal Clustering (TC) statistic, which is the first quantitative measure of the degree of topological 'temporal clustering' in a serially-sampled phylogeny. The TC statistic represents the expected deviation of an observed phylogeny from the null hypothesis of no temporal clustering, as a proportion of the range of possible values, and can therefore be compared among phylogeny of different sizes.We apply the TC statistic to a range of serially-sampled sequence datasets, which represent both rapidly-evolving viruses and ancient mitochondrial DNA. In addition, the TC statistic was calculated for phylogenies simulated under a neutral coalescent process.Our results indicate significant temporal clustering in many empirical datasets. However, we also find that such clustering is exhibited by trees simulated under a neutral coalescent process; hence the observation of significant 'temporal clustering' cannot unambiguously indicate that presence of strong positive selection in a population.Quantifying topological structure in this manner will provide new insights into the evolution of measurably evolving populations.

18.
São Paulo; SMS; 2 jun. 2011. 1 p. graf.
Não convencional em Português | Sec. Munic. Saúde SP, COVISA-Producao, Sec. Munic. Saúde SP, Sec. Munic. Saúde SP | ID: sms-1688
19.
São Paulo; São Paulo (Cidade). Secretaria da Saúde; 2 jun. 2011. 1 p. graf.
Não convencional em Português | Coleciona SUS, COVISA-Producao, Sec. Munic. Saúde SP, Sec. Munic. Saúde SP | ID: biblio-937241
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