Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 305
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
J Virol ; 98(2): e0150423, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38289119

RESUMO

Coxsackievirus B3 (CVB3) is known to cause acute myocarditis and pancreatitis in humans. We investigated the microRNAs (miRNAs) that can potentially govern the viral life cycle by binding to the untranslated regions (UTRs) of CVB3 RNA. MicroRNA-22-3p was short-listed, as its potential binding site overlapped with the region crucial for recruiting internal ribosome entry site trans-acting factors (ITAFs) and ribosomes. We demonstrate that miR-22-3p binds CVB3 5' UTR, hinders recruitment of key ITAFs on viral mRNA, disrupts the spatial structure required for ribosome recruitment, and ultimately blocks translation. Likewise, cells lacking miR-22-3p exhibited heightened CVB3 infection compared to wild type, confirming its role in controlling infection. Interestingly, miR-22-3p level was found to be increased at 4 hours post-infection, potentially due to the accumulation of viral 2A protease in the early phase of infection. 2Apro enhances the miR-22-3p level to dislodge the ITAFs from the SD-like sequence, rendering the viral RNA accessible for binding of replication factors to switch to replication. Furthermore, one of the cellular targets of miR-22-3p, protocadherin-1 (PCDH1), was significantly downregulated during CVB3 infection. Partial silencing of PCDH1 reduced viral replication, demonstrating its proviral role. Interestingly, upon CVB3 infection in mice, miR-22-3p level was found to be downregulated only in the small intestine, the primary target organ, indicating its possible role in influencing tissue tropism. It appears miR-22-3p plays a dual role during infection by binding viral RNA to aid its life cycle as a viral strategy and by targeting a proviral protein to restrict viral replication as a host response.IMPORTANCECVB3 infection is associated with the development of end-stage heart diseases. Lack of effective anti-viral treatments and vaccines for CVB3 necessitates comprehensive understanding of the molecular players during CVB3 infection. miRNAs have emerged as promising targets for anti-viral strategies. Here, we demonstrate that miR-22-3p binds to 5' UTR and inhibits viral RNA translation at the later stage of infection to promote viral RNA replication. Conversely, as host response, it targets PCDH1, a proviral factor, to discourage viral propagation. miR-22-3p also influences CVB3 tissue tropism. Deciphering the multifaced role of miR-22-3p during CVB3 infection unravels the necessary molecular insights, which can be exploited for novel intervening strategies to curb infection and restrict viral pathogenesis.


Assuntos
Regiões 5' não Traduzidas , Infecções por Coxsackievirus , Enterovirus Humano B , Interações entre Hospedeiro e Microrganismos , MicroRNAs , Biossíntese de Proteínas , RNA Viral , Animais , Humanos , Camundongos , Regiões 5' não Traduzidas/genética , Antivirais/metabolismo , Infecções por Coxsackievirus/genética , Infecções por Coxsackievirus/virologia , Enterovirus Humano B/genética , Enterovirus Humano B/patogenicidade , Enterovirus Humano B/fisiologia , Células HeLa , Intestino Delgado/metabolismo , Intestino Delgado/virologia , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Tropismo Viral/genética , Replicação Viral/genética , Cisteína Endopeptidases/metabolismo , Protocaderinas/deficiência , Protocaderinas/genética , Miocardite , Interações entre Hospedeiro e Microrganismos/genética
2.
PLoS Pathog ; 19(8): e1011552, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37540723

RESUMO

Host protein HuR translocation from nucleus to cytoplasm following infection is crucial for the life cycle of several RNA viruses including hepatitis C virus (HCV), a major causative agent of hepatocellular carcinoma. HuR assists the assembly of replication-complex on the viral-3'UTR, and its depletion hampers viral replication. Although cytoplasmic HuR is crucial for HCV replication, little is known about how the virus orchestrates the mobilization of HuR into the cytoplasm from the nucleus. We show that two viral proteins, NS3 and NS5A, act co-ordinately to alter the equilibrium of the nucleo-cytoplasmic movement of HuR. NS3 activates protein kinase C (PKC)-δ, which in-turn phosphorylates HuR on S318 residue, triggering its export to the cytoplasm. NS5A inactivates AMP-activated kinase (AMPK) resulting in diminished nuclear import of HuR through blockade of AMPK-mediated phosphorylation and acetylation of importin-α1. Cytoplasmic retention or entry of HuR can be reversed by an AMPK activator or a PKC-δ inhibitor. Our findings suggest that efforts should be made to develop inhibitors of PKC-δ and activators of AMPK, either separately or in combination, to inhibit HCV infection.


Assuntos
Hepacivirus , Hepatite C , Humanos , Hepacivirus/fisiologia , Proteínas Quinases Ativadas por AMP/metabolismo , Proteína Semelhante a ELAV 1/genética , Proteína Semelhante a ELAV 1/metabolismo , Citoplasma/metabolismo , Hepatite C/metabolismo , Linhagem Celular Tumoral , Replicação Viral , Proteínas não Estruturais Virais/metabolismo
3.
Ann Hematol ; 103(3): 749-758, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38242970

RESUMO

We studied the incidence of relapse, transformation to myelodysplastic syndrome/acute myeloid leukemia, and survival in patients with aplastic anemia (AA) surviving more than 1 year after ATG/ALG-based immunosuppressive therapy (IST) between 1985 and 2020. Four-hundred seventy patients (413 adults and 57 children) were studied, and data were compared with 223 patients who underwent matched sibling donor transplant (MSD HSCT). Median follow-up is 50 months (12-359). Relapse occurred in 21.9% at a median time of 33.5 months (5-228) post IST. Twenty-six (5.5%) patients progressed to PNH, while 20 (4.3%) evolved to MDS/AML. Ten-year estimated overall survival (OS) is 80.9 ± 3% and was significantly better in patients without an event (85.1 ± 4%) compared to relapse (74.6% ± 6.2%) or clonal evolution (12.8% ± 11.8%) (p = 0.024). While the severity of AA (p = 0.011) and type of ATG (p = 0.028) used predicted relapse, only age at IST administration influenced clonal evolution (p = 0.018). Among HSCT recipients, relapse rates were 4.9% with no clonal evolution, and the 10-year OS was 94.5 ± 2%. In patients who survived 1 year following IST, outcomes were good except with clonal evolution to MDS/AML. These outcomes, however, were still inferior compared to matched sibling donor HSCT.


Assuntos
Anemia Aplástica , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Adulto , Criança , Humanos , Doença Enxerto-Hospedeiro/etiologia , Estudos Retrospectivos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Terapia de Imunossupressão/efeitos adversos , Síndromes Mielodisplásicas/terapia , Síndromes Mielodisplásicas/complicações , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/complicações , Recidiva
4.
Eur J Haematol ; 112(5): 810-818, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38213291

RESUMO

INTRODUCTION: During normal aging, telomeric DNA is gradually lost in dividing somatic cells, and critically short telomeres lead to replicative senescence, apoptosis, or chromosomal instability. We studied telomere length in bone marrow failure syndromes (BMFS) compared to normal healthy population. METHODS: Peripheral blood was collected from the participants, and genomic DNA was extracted. Relative telomere length was measured using a quantitative polymerase chain reaction. Statistical analysis was performed using SPSS and GraphPad Prism 8.2 software. RESULTS: The median age of normal Indian population was 31 (0-60) years. As expected, telomere length (TL) showed a decline with age and no difference in TL between males and females. The median age of 650 patients with aplastic anemia (AA) was 30 (1-60) years. TL was significantly shorter in patients with AA compared to healthy controls (p < .001). In FA and MDS patients, TL was significantly shorter than age-matched healthy controls (p = .028; p < .001), respectively. There was no difference between the median TL in age-matched AA and FA patients (p = .727). However, patients with MDS had shorter TL than age-matched AA (p = .031). CONCLUSION: TL in BMF syndrome patients was significantly shorter than age-matched healthy controls.


Assuntos
Anemia Aplástica , Masculino , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Anemia Aplástica/diagnóstico , Anemia Aplástica/genética , Transtornos da Insuficiência da Medula Óssea , Telômero/genética , Encurtamento do Telômero , DNA
5.
J Med Genet ; 60(8): 801-809, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36894310

RESUMO

BACKGROUND: Fanconi anaemia (FA) is a rare inherited bone marrow failure disease caused by germline pathogenic variants in any of the 22 genes involved in the FA-DNA interstrand crosslink (ICL) repair pathway. Accurate laboratory investigations are required for FA diagnosis for the clinical management of the patients. We performed chromosome breakage analysis (CBA), FANCD2 ubiquitination (FANCD2-Ub) analysis and exome sequencing of 142 Indian patients with FA and evaluated the efficiencies of these methods in FA diagnosis. METHODS: We performed CBA and FANCD2-Ub analysis in the blood cells and fibroblasts of patients with FA. Exome sequencing with improved bioinformatics to detect the single number variants and CNV was carried out for all the patients. Functional validation of the variants with unknown significance was done by lentiviral complementation assay. RESULTS: Our study showed that FANCD2-Ub analysis and CBA on peripheral blood cells could diagnose 97% and 91.5% of FA cases, respectively. Exome sequencing identified the FA genotypes consisting of 45 novel variants in 95.7% of the patients with FA. FANCA (60.2%), FANCL (19.8%) and FANCG (11.7%) were the most frequently mutated genes in the Indian population. A FANCL founder mutation c.1092G>A; p.K364=was identified at a very high frequency (~19%) in our patients. CONCLUSION: We performed a comprehensive analysis of the cellular and molecular tests for the accurate diagnosis of FA. A new algorithm for rapid and cost-effective molecular diagnosis for~90% of FA cases has been established.


Assuntos
Anemia de Fanconi , Pancitopenia , Humanos , Anemia de Fanconi/diagnóstico , Anemia de Fanconi/genética , Fibroblastos , Genótipo , Técnicas de Laboratório Clínico
6.
J Gen Virol ; 104(6)2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37326617

RESUMO

Geminivirus-betasatellite disease complexes are an epidemic threat to the majority of economically important crops across the world. Plant virus satellites including betasatellites are maintained by their associated helper virus. Geminivirus-betasatellites influence viral pathogenesis by substantially increasing or decreasing their helper virus accumulation. In the present study, we attempted to understand the mechanistic details of the geminivirus-betasatellite interaction. Here, we used tomato leaf curl Gujarat virus (ToLCGV) and tomato leaf curl Patna betasatellite (ToLCPaB) as a model system. This study reveals that ToLCGV can efficiently trans-replicate ToLCPaB in Nicotiana benthamiana plants, but ToLCPaB greatly reduced the accumulation of its helper virus DNA. For the first time, we have identified that the ToLCPaB-encoded ßC1 protein is able to interact with ToLCGV-encoded replication initiator protein (Rep). In addition, we demonstrate that the C-terminal region of ßC1 interacts with the C-terminus of Rep (RepC) protein. Our previous study had established that ßC1 proteins encoded by diverse betasatellites possess a novel ATP hydrolysis activity and the conserved lysine/arginine residues at positions 49 and 91 are necessary for this function. Here, we show that mutating lysine at positions 49 to alanine of ßC1 (ßC1K49A) protein did not affect its ability to interact with RepC protein. Biochemical studies performed with ATP hydrolysis activity-deficient K49A mutated ßC1 (ßC1K49A) and RepC proteins revealed that Rep-ßC1 interaction interferes with the ATP hydrolysis activity of Rep protein. Further, we demonstrate that ßC1 protein is able to interact with D227A and D289A mutated RepC proteins but not with D262A, K272A or D286A mutated RepC proteins, suggesting that the ßC1-interacting region of Rep protein encompasses its Walker-B and B' motifs. The results of docking studies supported that the ßC1-interacting region of Rep protein encompasses its motifs associated with ATP binding and ATP hydrolysis activities. Docking studies also provided evidence that the Rep-ßC1 interaction interferes with the ATP binding activity of Rep protein. Together, our findings suggest that ßC1 protein regulates helper virus accumulation by interfering with the ATP hydrolysis activity of helper virus Rep protein.


Assuntos
Begomovirus , Geminiviridae , Geminiviridae/genética , Vírus Auxiliares , Lisina/metabolismo , Hidrólise , Proteínas Virais/genética , Proteínas Virais/metabolismo , Begomovirus/genética , Trifosfato de Adenosina/metabolismo , Doenças das Plantas , Nicotiana
7.
Blood Cells Mol Dis ; 99: 102727, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36725474

RESUMO

Iron deficiency anemia is associated with maternal morbidity and poor pregnancy outcomes. Heme and non-heme iron transport proteins expressed in the placenta help in adequate iron supply from anemic mother to fetus. Here we examined the expression of placental iron trafficking molecules and their association with maternal and neonatal iron status in pregnant women with iron deficiency anemia (IDA). Pregnant women who received prenatal care at Christian Medical College, Vellore, India for childbirth were recruited. Pregnant women who were 18-35 years old with gestational age (GA) of ≥36 weeks were eligible to participate in the study. In a prospective cohort of pregnant women, 22 % were iron deficiency anemia and 42 % were iron replete. Samples were collected (Maternal blood, placental tissue, and cord blood) from pregnant women with a gestational age of ≥38 weeks at the time of delivery. The mean gestational age at the first visit and delivery was 12.8 ± 2.72 weeks and 39 ± 1.65 weeks, respectively. Hemoglobin (9.3 ± 0.9 g/dl) and ferritin (15.4(0.8-28.3) ng/ml) levels at delivery were significantly decreased in IDA as compared to controls. The fetal hemoglobin and ferritin levels were in the normal range in both groups. There was no correlation between maternal and cord blood hepcidin with fetal iron status in IDA. We further analyzed the expression of iron transport genes in the placenta of controls and the IDA group. Under maternal iron insufficiency, the expression of placental iron transporters DMT1, FPN1, and GDF15 was upregulated at the protein level. In IDA, placental GDF15 and ferroportin protein had an association with fetal iron status. These findings confirm that placental iron traffickers respond to maternal iron deficiency by increasing their expression and allowing sufficient iron to pass to the fetus.


Assuntos
Anemia Ferropriva , Ferro , Recém-Nascido , Feminino , Humanos , Gravidez , Lactente , Adolescente , Adulto Jovem , Adulto , Ferro/metabolismo , Placenta/metabolismo , Cuidado Pré-Natal , Estudos Prospectivos , Ferritinas , Resultado da Gravidez , Proteínas de Membrana Transportadoras , Sangue Fetal/metabolismo
8.
Blood ; 137(4): 556-568, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33104215

RESUMO

Social determinants of health, including poverty, contribute significantly to health outcomes in the United States; however, their impact on pediatric hematopoietic cell transplantation (HCT) outcomes is poorly understood. We aimed to identify the association between neighborhood poverty and HCT outcomes for pediatric allogeneic HCT recipients in the Center for International Blood and Marrow Transplant Research database. We assembled 2 pediatric cohorts undergoing first allogeneic HCT from 2006 to 2015 at age ≤18 years, including 2053 children with malignant disease and 1696 children with nonmalignant disease. Neighborhood poverty exposure was defined a priori per the US Census definition as living in a high-poverty ZIP code (≥20% of persons below 100% federal poverty level) and used as the primary predictor in all analyses. Our primary outcome was overall survival (OS), defined as the time from HCT until death resulting from any cause. Secondary outcomes included relapse and transplantation-related mortality (TRM) in malignant disease, acute and chronic graft-versus-host disease, and infection in the first 100 days post-HCT. Among children undergoing transplantation for nonmalignant disease, neighborhood poverty was not associated with any HCT outcome. Among children undergoing transplantation for malignant disease, neighborhood poverty conferred an increased risk of TRM but was not associated with inferior OS or any other transplantation outcome. Among children with malignant disease, a key secondary finding was that children with Medicaid insurance experienced inferior OS and increased TRM compared with those with private insurance. These data suggest opportunities for future investigation of the effects of household-level poverty exposure on HCT outcomes in pediatric malignant disease to inform care delivery interventions.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Pobreza , Determinantes Sociais da Saúde , Adolescente , Causas de Morte , Criança , Pré-Escolar , Doença Crônica/mortalidade , Doença Crônica/terapia , Bases de Dados Factuais , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/epidemiologia , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/economia , Transplante de Células-Tronco Hematopoéticas/mortalidade , Transplante de Células-Tronco Hematopoéticas/estatística & dados numéricos , Humanos , Lactente , Infecções/epidemiologia , Cobertura do Seguro/estatística & dados numéricos , Masculino , Medicaid , Neoplasias/mortalidade , Neoplasias/terapia , Recidiva , Análise de Sobrevida , Transplante Homólogo , Resultado do Tratamento , Estados Unidos
9.
Strahlenther Onkol ; 199(10): 922-935, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37278833

RESUMO

PURPOSE: Total marrow lymphoid irradiation (TMLI) with volumetric modulated arc therapy (VMAT) is challenging due to large treatment fields with multiple isocenters, field matching at junctions, and targets being surrounded by many organs at risk. This study aimed to describe our methodology for safe dose escalation and accurate dose delivery of TMLI treatment with the VMAT technique based on early experience at our center. MATERIALS AND METHODS: Computed tomography (CT) scans were acquired in head-first supine and feet-first supine orientations for each patient with an overlap at mid-thigh. VMAT plans were generated for 20 patients on the head-first CT images with either three or four isocenters in the Eclipse treatment planning system (Varian Medical Systems Inc., Palo Alto, CA) and the treatment was delivered in a Clinac 2100 C/D linear accelerator (Varian Medical Systems Inc., Palo Alto, CA). RESULTS: Five patients were treated with a prescription dose of 13.5 Gy in 9 fractions and 15 patients were treated with an escalated dose of 15 Gy in 10 fractions. The mean doses to 95% of the clinical target volume (CTV) and planning target volume (PTV) were 14.3 ± 0.3 Gy and 13.6 ± 0.7 Gy for the prescription doses of 15 Gy, and 13 ± 0.2 Gy and 12.3 ± 0.3 Gy for the prescription doses of 13.5 Gy, respectively. Mean dose to the lung in both schedules was 8.7 ± 0.6 Gy. The overall time taken to execute the treatment plans was approximately 2 h for the first fraction and 1.5 h for subsequent fractions. The average in-room time of 15.5 h per patient over 5 days leads to potential changes in the regular treatment schedules for other patients. CONCLUSION: This feasibility study highlights the methodology adopted for safe implementation of TMLI with the VMAT technique at our institution. Escalation of dose to the target with adequate coverage and sparing of critical structures was achieved with the adopted treatment technique. Clinical implementation of this methodology at our center could serve as a practical guide to start the VMAT-based TMLI program safely by others who are keen to start this service.


Assuntos
Radioterapia de Intensidade Modulada , Humanos , Medula Óssea/efeitos da radiação , Estudos de Viabilidade , Irradiação Linfática , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Centros de Atenção Terciária
10.
Clin Transplant ; 37(9): e15010, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37144852

RESUMO

INTRODUCTION: Total marrow lymphoid irradiation (TMLI) can deliver higher doses of irradiation without increasing toxicity compared to Total body irradiation (TBI). METHODS: Twenty adult patients undergoing hematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia with lymphoid blast crises (CML-LBC) received TMLI and cyclophosphamide for conditioning. Ten patients each received 13.5 or 15 Gy of TMLI. The graft source was peripheral blood stem cells in all, and donors included matched related (n = 15), haplo-identical (n = 3) or matched unrelated donors (n = 2). RESULTS: The median cell dose infused was 9 × 106 CD34/kg (range 4.8-12.4). Engraftment occurred in all (100%) at a median of 15 days (range: 14-17). Toxicity was low with hemorrhagic cystitis seen in two but no sinusoidal obstruction syndrome. Acute GVHD occurred in 40% while chronic GVHD was seen in 70.5%. Viral infections were seen in 55% while blood stream bacterial infections occurred in 20% and invasive fungal disease (IFD) in 10%. The Day 100 non-relapse mortality (NRM) was 10%. At a median follow up of 25 months (range 2-48), two patients have relapsed. Overall survival at 2 years is 80% while the disease-free survival is 75%. CONCLUSIONS: The combination of TMLI and cyclophosphamide for myeloablative conditioning is associated with low toxicity and favorable early outcomes in patients undergoing HSCT for ALL and CML-LBC.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Leucemia Mielogênica Crônica BCR-ABL Positiva , Leucemia Mieloide Aguda , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adulto , Humanos , Medula Óssea/efeitos da radiação , Crise Blástica , Irradiação Linfática , Ciclofosfamida/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/etiologia , Doença Enxerto-Hospedeiro/etiologia , Doença Crônica , Condicionamento Pré-Transplante/efeitos adversos , Leucemia Mieloide Aguda/etiologia , Estudos Retrospectivos
11.
Ann Clin Microbiol Antimicrob ; 22(1): 12, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36793051

RESUMO

PURPOSE: Identifying persistent bacteremia early in patients with neutropenia may improve outcome. This study evaluated the role of follow-up blood cultures (FUBC) positivity in predicting outcomes among patients with neutropenia and carbapenem-resistant gram-negative bloodstream infections (CRGNBSI). METHODS: This retrospective cohort study conducted between December 2017 and April 2022 included patients more than 15 years old with neutropenia and CRGNBSI, who survived for ≥ 48 h, receiving appropriate antibiotic therapy and had FUBCs. Patients with polymicrobial bacteremia within 30 days were excluded. The primary outcome was 30 day mortality. Persistent bacteremia, septic shock, recovery from neutropenia, prolonged or profound neutropenia, requirement of intensive care and dialysis, and initiation of appropriate empirical therapy were also studied. RESULTS: In our study cohort of 155 patients, the 30 day mortality rate was 47.7%. Persistent bacteremia was common in our patient cohort (43.8%). Carbapenem resistant isolates identified in the study were K.pneumoniae (80%), E.coli (12.26%), P.aeruginosa (5.16%), A.baumanii (1.94%) and E.cloacae (0.65%). The median time for sending a FUBC was 2 days (IQR, 1-3 days). Patients with persistent bacteremia had higher mortality than those without (56.76% versus 32.1%; p < 0.001). Appropriate initial empirical therapy was given to 70.9%. Recovery from neutropenia occurred in 57.4% while 25.8% had prolonged or profound neutropenia. Sixty-nine percent (107/155) had septic shock and needed intensive care; 12.2% of patients required dialysis. Non-recovery from neutropenia (aHR, 4.28; 95% CI 2.53-7.23), presence of septic shock (aHR, 4.42; 95%CI 1.47-13.28), requirement of intensive care (aHR,3.12;95%CI 1.23-7.93), and persistent bacteremia (aHR,1.74; 95%CI 1.05-2.89) significantly predicted poor outcomes in multivariable analysis. CONCLUSION: FUBC showing persistent bacteremia predicted poor outcomes among neutropenic patients with carbapenem-resistant gram-negative bloodstream infections (CRGNBSI) and should be routinely reported.


Assuntos
Bacteriemia , Neutropenia , Choque Séptico , Humanos , Adolescente , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Estudos Retrospectivos , Choque Séptico/tratamento farmacológico , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Neutropenia/complicações , Neutropenia/tratamento farmacológico
12.
J Stroke Cerebrovasc Dis ; 32(11): 107305, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37677898

RESUMO

INTRODUCTION: Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal hematopoietic disorder, where there is deficiency of glycosylphosphatidylinositol (GPI) anchored proteins in the cell membrane, leading to increased complement sensitivity of red blood cells, intravascular hemolysis and vascular inflammation. Arterial and venous strokes in patients with PNH are a rarity posing significant diagnostic and therapeutic challenges. We report our experience with management of PNH patients with cerebrovascular emergencies. METHODS: We report 2 patients with PNH, one who was previously diagnosed with PNH and had arterial stroke, the other had an index presentation of cerebral venous sinus thrombosis (CVT) and was subsequently diagnosed with PNH. We also present the systematic review of literature reporting similar cases, highlighting the challenges in management. RESULTS: Both patients presented to our centre with cerebrovascular emergency. The first patient was a diagnosed with PNH, and presented with left hemispheric infarction caused by thrombosis of middle cerebral artery. He was thrombolysed and underwent mechanical thrombectomy, which was unsuccessful in view of repeated re - thrombosis of the vessel. The patient survived with significant disability. The second patient had severe cerebral venous sinus thrombosis with large right hemispheric hemorrhagic venous infarction. She underwent emergency decompressive hemicraniectomy complicated by massive blood loss and disseminated intravascular coagulation. She subsequently had recurrent life threatening intracranial bleed secondary to platelet transfusions, thrombocytopenia, and use of contrast agents. She progressed to develop Budd Chiari syndrome and was initiated on Eculuzimab. She became transfusion independent, however remained in minimally conscious state and succumbed to sepsis. CONCLUSIONS: Management of arterial and venous strokes is complex in patients with PNH. Invasive procedures and platelet transfusions are to be avoided in acute thrombosis, till robust evidence is available establishing the safety of the same in patients with PNH. Eculuzimab is a promising option, but far from reach for patients in developing countries.

13.
Br J Haematol ; 196(3): 724-734, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34605011

RESUMO

Although telomere shortening is seen frequently in patients with aplastic anaemia (AA), there are no data on its association in matched sibling donor (MSD) transplants. We evaluated the effect of pre-transplant telomere length of patients and donors, measured by quantitative real-time polymerase chain reaction in 163 recipients undergoing MSD transplants. The median age of patients and donors was 24 and 26 years, respectively. Fludarabine and cyclophosphamide was the main conditioning regimen used and all received peripheral blood stem cell grafts. Engraftment occurred in 89% with graft failure (primary and secondary) in 6%. Acute and chronic graft-versus-host disease (GVHD) occurred in 28% and 24%, respectively. At a median follow-up of 37 months, 117 patients (72%) were alive. All patients and donors were divided into short and long telomere length based on their median and quartile values. Patient telomere length was not associated with severity of AA, neutrophil recovery, graft failure, acute GVHD or chronic GVHD. Longer donor telomere length was associated with better overall survival [hazard ratio (HR) = 0·2, P = 0·006] but did not influence neutrophil recovery, graft failure, acute or chronic GVHD. The five-year overall survival was significantly better (94·9 ± 3·5% vs 65·4 ± 4·3%, P = 0·002) for donors with long (highest quartile, DTL-HQ) versus short (lower three quartiles, DTL-LQ) telomeres, respectively. On multivariate analysis, longer donor telomere length, recipient age and acute GVHD continued to remain significant. This is the first study demonstrating an association of donor telomere length on overall survival following MSD transplant for AA but it needs to be confirmed in larger studies.


Assuntos
Anemia Aplástica/mortalidade , Anemia Aplástica/terapia , Transplante de Células-Tronco Hematopoéticas , Irmãos , Homeostase do Telômero , Telômero/genética , Doadores de Tecidos , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Transplante de Células-Tronco Hematopoéticas/métodos , Transplante de Células-Tronco Hematopoéticas/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Condicionamento Pré-Transplante/métodos , Resultado do Tratamento , Adulto Jovem
14.
J Virol ; 95(21): e0091521, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34406862

RESUMO

Coxsackievirus B3 (CVB3) is an enterovirus belonging to the family Picornaviridae. Its 5' untranslated region (UTR) contains a cloverleaf structure followed by an internal ribosome entry site (IRES). The cloverleaf forms an RNA-protein complex known to regulate virus replication, translation, and stability of the genome, and the IRES regulates virus RNA translation. For positive-strand RNA-containing viruses, such as members of the flaviviruses or enteroviruses, the genomic RNA is used for translation, replication, and encapsidation. Only a few regulatory mechanisms which govern the accessibility of genomic RNA templates for translation or replication have been reported. Here, we report the role of human antigen R (HuR) in regulating the fate of CVB3 positive-strand RNA into the replication cycle or translation cycle. We have observed that synthesis of HuR is induced during CVB3 infection, and it suppresses viral replication by displacing PCBP-2 (a positive regulator of virus replication) at the cloverleaf RNA. Silencing of HuR increases viral RNA replication and consequently reduces viral RNA translation in a replication-dependent manner. Furthermore, we have shown that HuR level is upregulated upon CVB3 infection. Moreover, HuR limits virus replication and can coordinate the availability of genomic RNA templates for translation, replication, or encapsidation. Our study highlights the fact that the relative abundance of translation factors and replication factors in the cell decides the outcome of viral infection. IMPORTANCE A positive-strand RNA virus must balance the availability of its genomic template for different viral processes at different stages of its life cycle. A few host proteins are shown to be important to help the virus in switching the usage of a template between these processes. These proteins inhibit translation either by displacing a stimulator of translation or by binding to an alternative site. Both mechanisms lead to ribosome clearance and availability of the genomic strand for replication. We have shown that HuR also helps in maintaining this balance by inhibiting replication and subsequently promoting translation and packaging.


Assuntos
Infecções por Coxsackievirus/metabolismo , Infecções por Coxsackievirus/virologia , Proteína Semelhante a ELAV 1/fisiologia , Enterovirus Humano B/fisiologia , RNA Viral/metabolismo , Regiões 5' não Traduzidas , Animais , Regulação Viral da Expressão Gênica , Inativação Gênica , Células HeLa , Interações entre Hospedeiro e Microrganismos , Humanos , Sítios Internos de Entrada Ribossomal , Estágios do Ciclo de Vida , Proteínas de Ligação a RNA/metabolismo , Ribossomos/metabolismo , Replicação Viral
15.
Ann Hematol ; 101(9): 1987-2000, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35840818

RESUMO

The role of next-generation sequencing (NGS) in identifying mutations in the driver, epigenetic regulator, RNA splicing, and signaling pathway genes in myeloproliferative neoplasms (MPNs) has contributed substantially to our understanding of the disease pathogenesis as well as disease evolution. NGS aids in determining the clonal nature of the disease in a subset of these disorders where mutations in the driver genes are not detected. There is a paucity of real-world data on the utility of this test in the characterization of triple-negative myeloproliferative neoplasms (TN-MPN). In this study, 46 samples of TN-MPN (essential thrombocythemia (ET) = 17; primary myelofibrosis (PMF) = 23; & myeloproliferative neoplasm unclassified (MPN-u) = 6) were screened for markers of clonality using targeted NGS. Among these, 25 (54.3%) patients had mutations that would help determine the clonal nature of the disease. Eight of the 17 TN-ET (47%) and 13 of the 23 TN-PMF (56.5%) patients had noncanonical mutations in the driver genes and mutations in the genes involved in epigenetic regulation. Identification of mutations categorized as high molecular markers (HMR) in 2 patients helped classify them as PMF with high risk according to the MIPSS 70 scoring system. A novel mutation in the MPIG6B (C6orf25) gene associated with childhood myelofibrosis was detected in a 14-year-old girl. The presence of clonal hematopoiesis could be confirmed in four of the six MPN-u patients in this cohort. This study demonstrates the utility of NGS in improving the characterization of TN-MPN by establishing clonality and detecting noncanonical mutations in driver genes, thereby aiding in clinical decision-making.


Assuntos
Transtornos Mieloproliferativos , Neoplasias , Trombocitemia Essencial , Adolescente , Criança , Epigênese Genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Janus Quinase 2/genética , Mutação , Transtornos Mieloproliferativos/diagnóstico , Transtornos Mieloproliferativos/genética , Trombocitemia Essencial/diagnóstico , Trombocitemia Essencial/genética
16.
Curr Microbiol ; 79(10): 288, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35972696

RESUMO

The 5'UTR of the genomic RNA of CVB3, unusually long and rich on highly structured secondary structure, contains a conserved cis acting RNA element named the cryptic AUG (cAUG), where the cellular 48S complex is formed. In this study, we investigate the role of this cAUG in CVB3 translation, replication, and virulence. Mutant viral sub-genomic replicon RNA was constructed by site-directed mutagenesis. We characterize in vitro translation and replication efficiencies and in vivo virulence of a cAUG mutant in comparison with wild-type strain. UV-cross-linking assay and Real-Time PCR were used, respectively, to detect binding host proteins and to quantify viral production. Secondary structures of domain containing the cAUG site were studied and compared. The results suggest that introduced mutation in the CVB3 5'UTR affects in vitro and ex vivo viral translation which cannot be rescued by compensatory mutations. A reduced interaction of the La and PCBP2 translation initiation factors with cAUG residue of mutant was revealed. Decreasing production of viral mutant RNA was also demonstrated. Furthermore, secondary structure prediction reveals changes in the ribosome binding sites of the cAUG moiety of mutant sense strand RNA and no alterations in the structure of wild type, suggesting that cAUG mutation specifically affects the secondary structure of the sense RNA strand. Taken together, AUG integrity influences the efficiency of ribosome recruitment through IRES element and the capacity of replication.


Assuntos
Enterovirus Humano B , RNA Viral , Regiões 5' não Traduzidas , Enterovirus Humano B/genética , Enterovirus Humano B/metabolismo , Células HeLa , Humanos , Mutação , Conformação de Ácido Nucleico , Biossíntese de Proteínas , RNA Viral/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Virulência/genética , Replicação Viral
17.
Br J Haematol ; 192(2): 292-299, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33216980

RESUMO

The standard of care for patients with acute promyelocytic leukaemia (APL) relapsing after front-line treatment with arsenic trioxide (ATO)-based regimens remains to be defined. A total of 67 patients who relapsed after receiving ATO-based up-front therapy and were also salvaged using an ATO-based regimen were evaluated. The median (range) age of patients was 28 (4-54) years. While 63/67 (94%) achieved a second molecular remission (MR) after salvage therapy, three (4·5%) died during salvage therapy. An autologous stem cell transplant (auto-SCT) was offered to all patients who achieved MR, 35/63 (55·6%) opted for auto-SCT the rest were administered an ATO + all-trans retinoic acid maintenance regimen. The mean (SD) 5-year Kaplan-Meier estimate of overall survival and event-free survival of those who received auto-SCT versus those who did not was 90·3 (5·3)% versus 58·6 (10·4)% (P = 0·004), and 87·1 (6·0)% versus 47·7 (10·3)% (P = 0·001) respectively. On multivariate analysis, failure to consolidate MR with an auto-SCT was associated with a significantly increased risk of relapse [hazard ratio (HR) 4·91, 95% confidence interval (CI) 1·56-15·41; P = 0·006]. MR induction with ATO-based regimens followed by an auto-SCT in children and young adults with relapsed APL who were treated with front-line ATO-based regimens was associated with excellent long-term survival.


Assuntos
Antineoplásicos/uso terapêutico , Trióxido de Arsênio/uso terapêutico , Leucemia Promielocítica Aguda/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adolescente , Adulto , Criança , Pré-Escolar , Gerenciamento Clínico , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Terapia de Salvação , Resultado do Tratamento , Adulto Jovem
18.
J Clin Immunol ; 41(2): 393-413, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33225392

RESUMO

Primary immunodeficiency diseases (PIDs) are a group of clinically and genetically heterogeneous disorders showing ethnic and geographic diversities. Next-generation sequencing (NGS) is a comprehensive tool to diagnose PID. Although PID is common in India, data on the genetic spectrum of PIDs are limited due to financial restrictions. The study aims to characterize the clinical and genetic spectrum of PID patients in India and highlight the importance of a cost-effective targeted gene panel sequencing approach for PID in a resource-limited setting. The study includes 229 patients with clinical and laboratory features suggestive of PIDs. Mutation analysis was done by Sanger sequencing and NGS targeting a customized panel of genes. Pathogenic variants were identified in 97 patients involving 42 different genes with BTK and IL12RB1 being the most common mutated genes. Autosomal recessive and X-linked recessive inheritance were seen in 51.6% and 23.7% of patients. Mendelian susceptibility to mycobacterial diseases (MSMD) and IL12RB1 mutations was more common in our population compared to the Western world and the Middle East. Two patients with hypomorphic RAG1 mutations and one female with skewed CYBB mutation were also identified. Another 40 patients had variants classified as variants of uncertain significance (VUS). The study shows that targeted NGS is an effective diagnostic strategy for PIDs in countries with limited diagnostic resources. Molecular diagnosis of PID helps in genetic counseling and to make therapeutic decisions including the need for a stem cell transplantation.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Patologia Molecular/métodos , Doenças da Imunodeficiência Primária/diagnóstico , Doenças da Imunodeficiência Primária/genética , Adolescente , Adulto , Criança , Pré-Escolar , Análise Mutacional de DNA/métodos , Feminino , Testes Genéticos/métodos , Humanos , Índia , Lactente , Recém-Nascido , Masculino , Mutação/genética , Adulto Jovem
19.
Transfus Apher Sci ; 60(1): 102962, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33051092

RESUMO

The use of cytokine mobilized peripheral blood stem cells (PBSC) for stem cell transplantation offers early engraftment, and less early transplant related mortality and morbidity. This can be done easily in the out-patient setting in an adult donor, but is difficult in children. The safety and efficacy of general anaesthesia outside the controlled operation room setting is quite challenging and demanding. We present our experience with paediatric PBSC harvest done under anaesthesia in the out-patient setting between January 2009 to June 2017. A total of 158 children underwent 164 PBSC harvests during the study period. Donors were predominantly females with a median age of 5 years (1-12) and a median weight of 17.5 kg (9.4-51). In 50% of the cases, induction of anaesthesia was by sevoflurane followed by total intravenous anaesthesia (TIVA) while in 32% it was sevoflurane induction followed by sedation. Hudson mask (48.5%) and laryngeal mask airway (50%) were the most common modes of airway and all patients were ventilated in the spontaneous mode. Propofol was the most commonly used maintenance agent (67%). There were no major complications except for acute pulmonary edema secondary to infusion of blood products requiring a short stay in ICU for one donor. All donors were discharged on the next day of harvest. No long term complications have been reported in any of these donors. Paediatric PBSC harvest can be safely done under anaesthesia with due precautions in the day care setting.


Assuntos
Anestesia/métodos , Transplante de Células-Tronco de Sangue Periférico/métodos , Células-Tronco de Sangue Periférico/metabolismo , Pré-Escolar , Hospital Dia , Feminino , Humanos , Masculino
20.
Can J Neurol Sci ; 48(5): 616-625, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33397535

RESUMO

OBJECTIVES: To study the clinical profile and outcomes of patients with paraproteinemic neuropathy (PPN) and to explore the utility of nerve conduction studies (NCSs) to differentiate between the demyelinating subtypes. METHODS: We did a retrospective analysis of patients diagnosed with PPN between January 2010 and December 2019 in an inpatient setting. The study population consisted of patients above 16 years of age presenting with clinical features suggestive of chronic peripheral neuropathy and on evaluation was found to have PPN. RESULTS: A total of 74 patients were identified. The patients were predominantly in the 6th decade, and the majority were males. The subtypes of PPN were monoclonal gammopathy of undetermined significance (MGUS) (45.9%), POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes) (24.3%), solitary plasmacytoma (17.6%), multiple myeloma (8.1%), and AL amyloidosis (4.1%). There are specific features on NCS which can help in identifying POEMS syndrome and IgM MGUS. The majority of patients with PPN tend to stabilize or improve with treatment; however, many have a severe residual disability. New terminology and classification of these entities as 'monoclonal gammopathies of neurological significance' can aid in early diagnosis and the development of effective treatment, to prevent residual disability. CONCLUSION: PPN has a heterogeneous spectrum of clinical, biochemical, and electrophysiological features. NCS can help distinguish POEMS syndrome and IgM MGUS from other demyelinating subtypes.


Assuntos
Gamopatia Monoclonal de Significância Indeterminada , Paraproteinemias , Doenças do Sistema Nervoso Periférico , Plasmocitoma , Humanos , Masculino , Gamopatia Monoclonal de Significância Indeterminada/complicações , Gamopatia Monoclonal de Significância Indeterminada/diagnóstico , Paraproteinemias/complicações , Paraproteinemias/diagnóstico , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA