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1.
J Pathol ; 245(1): 85-100, 2018 05.
Article in English | MEDLINE | ID: mdl-29435980

ABSTRACT

Alzheimer's disease (AD) is a devastating neurological disorder that still lacks an effective treatment, and this has stimulated an intense pursuit of disease-modifying therapeutics. Given the increasingly recognized link between AD and defective brain insulin signaling, we investigated the actions of liraglutide, a glucagon-like peptide-1 (GLP-1) analog marketed for treatment of type 2 diabetes, in experimental models of AD. Insulin receptor pathology is an important feature of AD brains that impairs the neuroprotective actions of central insulin signaling. Here, we show that liraglutide prevented the loss of brain insulin receptors and synapses, and reversed memory impairment induced by AD-linked amyloid-ß oligomers (AßOs) in mice. Using hippocampal neuronal cultures, we determined that the mechanism of neuroprotection by liraglutide involves activation of the PKA signaling pathway. Infusion of AßOs into the lateral cerebral ventricle of non-human primates (NHPs) led to marked loss of insulin receptors and synapses in brain regions related to memory. Systemic treatment of NHPs with liraglutide provided partial protection, decreasing AD-related insulin receptor, synaptic, and tau pathology in specific brain regions. Synapse damage and elimination are amongst the earliest known pathological changes and the best correlates of memory impairment in AD. The results illuminate mechanisms of neuroprotection by liraglutide, and indicate that GLP-1 receptor activation may be harnessed to protect brain insulin receptors and synapses in AD. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Subject(s)
Cognitive Dysfunction/drug therapy , Liraglutide/pharmacology , Memory/drug effects , Receptor, Insulin/drug effects , Synapses/pathology , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Animals , Disease Models, Animal , Hippocampus/drug effects , Hypoglycemic Agents/pharmacology , Male , Mice , Receptor, Insulin/metabolism , Synapses/drug effects
2.
Mem. Inst. Oswaldo Cruz ; 112(7): 492-498, July 2017. tab
Article in English | LILACS | ID: biblio-841811

ABSTRACT

BACKGROUND Increasing evidence suggests that human papillomavirus (HPV) intratype variants (specific lineages and sublineages) are associated with pathogenesis and progression from HPV infection to persistence and the development of cervical cancer. OBJECTIVES This study aimed to verify the prevalence of HPV infection and distribution of HPV types and HPV16 variants in southern Brazil in women with normal cytology or intraepithelial lesions. METHODS HPV typing was determined by L1 gene sequencing. To identify HPV16 variants, the LCR and E6 regions were sequenced, and characteristic single nucleotide variants were identified. FINDINGS A total of 445 samples were studied, with 355 from cervical scrapes and 90 from cervical biopsies. HPV was detected in 24% and 91% of these samples, respectively. The most prevalent HPV types observed were 16 (cervical, 24%; biopsies, 57%) and 58 (cervical, 12%; biopsies, 12%). Seventy-five percent of the HPV16-positive samples were classified into lineages, with 88% defined as lineage A, 10% as lineage D, and 2% as lineage B. MAIN CONCLUSIONS This study identified a high frequency of European and North American HPV16 lineages, consistent with the genetic background of the human population in southern Brazil.


Subject(s)
Humans , Female , Adult , Genetic Variation/genetics , DNA, Viral/genetics , Uterine Cervical Neoplasms/virology , Papillomavirus Infections/virology , Human papillomavirus 16/genetics , Socioeconomic Factors , Brazil , Uterine Cervical Dysplasia , Polymerase Chain Reaction , Cross-Sectional Studies
3.
Mem Inst Oswaldo Cruz ; 112(7): 492-498, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28591310

ABSTRACT

BACKGROUND: Increasing evidence suggests that human papillomavirus (HPV) intratype variants (specific lineages and sublineages) are associated with pathogenesis and progression from HPV infection to persistence and the development of cervical cancer. OBJECTIVES: This study aimed to verify the prevalence of HPV infection and distribution of HPV types and HPV16 variants in southern Brazil in women with normal cytology or intraepithelial lesions. METHODS: HPV typing was determined by L1 gene sequencing. To identify HPV16 variants, the LCR and E6 regions were sequenced, and characteristic single nucleotide variants were identified. FINDINGS: A total of 445 samples were studied, with 355 from cervical scrapes and 90 from cervical biopsies. HPV was detected in 24% and 91% of these samples, respectively. The most prevalent HPV types observed were 16 (cervical, 24%; biopsies, 57%) and 58 (cervical, 12%; biopsies, 12%). Seventy-five percent of the HPV16-positive samples were classified into lineages, with 88% defined as lineage A, 10% as lineage D, and 2% as lineage B. MAIN CONCLUSIONS: This study identified a high frequency of European and North American HPV16 lineages, consistent with the genetic background of the human population in southern Brazil.


Subject(s)
Genetic Variation/genetics , Human papillomavirus 16/genetics , Papillomavirus Infections/virology , Uterine Cervical Dysplasia/virology , Uterine Cervical Neoplasms/virology , Adult , Brazil , Cross-Sectional Studies , DNA, Viral/genetics , Female , Humans , Polymerase Chain Reaction , Socioeconomic Factors
4.
Rev. Inst. Med. Trop. Säo Paulo ; 56(2): 133-138, Mar-Apr/2014. tab
Article in English | LILACS | ID: lil-703735

ABSTRACT

In the absence of intervention, the rate of vertical transmission of HIV can range from 15-45%. With the inclusion of antiretroviral drugs during pregnancy and the choice of delivery route this amounts to less than 2%. However ARV use during pregnancy has generated several questions regarding the adverse effects of the gestational and neonatal outcome. This study aims to analyze the risk factors for vertical transmission of HIV-1 seropositive pregnant women living in Rio Grande and the influence of the use of ARVs in pregnancy outcome. Among the 262 pregnant women studied the rate of vertical transmission of HIV was found to be 3.8%. Regarding the VT, there was a lower risk of transmission when antiretroviral drugs were used and prenatal care was conducted at the referral service. However, the use of ART did not influence the outcome of pregnancy. However, initiation of prenatal care after the first trimester had an influence on low birth weight, as well as performance of less than six visits increased the risk of prematurity. Therefore, the risk factors analyzed in this study appear to be related to the realization of inadequate pre-natal and maternal behavior.


Na ausência de intervenção, as taxas de transmissão vertical do HIV podem variar de 15-45%. Com a inserção dos antirretrovirais durante a gestação e a escolha da via de parto estas taxas chegam a menos de 2%. No entanto o uso de ARV na gestação tem gerado várias duvidas quanto aos efeitos adversos causados ao desfecho gestacional e ao neonato. Este estudo objetiva analisar os fatores de risco da transmissão vertical do HIV-1 em gestantes soropositivas atendidas na cidade do Rio Grande e a influência do uso do ARV no desfecho gestacional. Entre as 262 gestantes estudadas a taxa de transmissão vertical do HIV encontrada foi de 3,8%. Em relação à TV, foi observado menor risco de transmissão quando esta havia feito uso de antirretrovirais e o pré-natal era realizado no serviço de referência. Entretanto, o uso de ARV não influenciou negativamente o desfecho gestacional. No entanto, o inicio do pré-natal após o primeiro trimestre teve influencia sobre o baixo peso ao nascer, assim como a realização de menos de seis consultas aumentou o risco de prematuridade. Portanto, os fatores de risco analisados neste estudo parecem estar relacionados à realização não adequada do pré-natal e ao comportamento materno.


Subject(s)
Adult , Female , Humans , Infant, Newborn , Pregnancy , Young Adult , Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , HIV Infections/transmission , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Outcome , Pregnancy Complications, Infectious/drug therapy , Apgar Score , Educational Status , HIV-1 , Infant, Low Birth Weight , Infant, Premature , Parity , Risk Factors
5.
AIDS ; 20(16): 2011-9, 2006 Oct 24.
Article in English | MEDLINE | ID: mdl-17053347

ABSTRACT

OBJECTIVE: To identify a new circulating recombinant form (CRF) of HIV-1 comprising two circulating subtypes in the southern region in Brazil, subtypes B and C. METHODS: A total of 152 HIV-positive patients followed at two hospitals in southern Brazil had their viral pol genes isolated by reverse transcriptase-polymerase chain reaction (PCR) from plasma. PCR products were sequenced and phylogenetically analysed using HIV-1 subtype reference sequences. Six full-length subtype C viruses from Brazil previously described as 'pure' strains were included in the analysis. Sequences suggestive of recombination were analysed by boot scanning and phylogenetic analyses of separate fragments. The common ancestry of recombinant strains was evaluated by similarity plot and informative site analyses. RESULTS: : HIV-1 subtypes commonly found in Brazil (B, C and F1) were observed. Sixty-two viruses were initially assigned as subtype C, but 15 viruses clustered in a separate internal clade. Pol from two full-length genomes of subtype C viruses grouped together with those samples. Boot scanning analysis showed that all 17 viruses had the same recombinant structure, with a 240 base pair fragment of subtype B in the middle of the reverse transcriptase pol region. Subtype B assignment of this fragment was confirmed by phylogenetic analyses using different methods of tree inference and cluster robustness tests. Mosaics were shown to have a common ancestry. CONCLUSION: As CRF_BC represents 11% of the HIV-1 viruses circulating in the southern region of the country, which borders several south American countries, the assessment of its spread is of pivotal importance to the HIV/AIDS epidemic in Brazil and Latin America.


Subject(s)
HIV Infections/virology , HIV-1/classification , Base Sequence , Brazil , Genes, pol , Genome , HIV-1/genetics , HIV-1/isolation & purification , Humans , Molecular Sequence Data , Phylogeny , RNA, Viral/analysis , Recombination, Genetic , Reverse Transcriptase Polymerase Chain Reaction/methods
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