Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Kidney Int ; 101(5): 1027-1038, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35124011

RESUMO

Long-term adaptive immune memory has been reported among immunocompetent individuals up to eight months following SARS-CoV-2 infection. However, limited data is available in convalescent patients with a solid organ transplant. To investigate this, we performed a thorough evaluation of adaptive immune memory at different compartments (serological, memory B cells and cytokine [IFN-γ, IL-2, IFN-γ/IL12 and IL-21] producing T cells) specific to SARS-CoV-2 by ELISA and FluoroSpot-based assays in 102 convalescent patients (53 with a solid organ transplants (38 kidney, 5 liver, 5 lung and 5 heart transplant) and 49 immunocompetent controls) with different clinical COVID-19 severity (severe, mild and asymptomatic) beyond six months after infection. While similar detectable memory responses at different immune compartments were detected between those with a solid organ transplant and immunocompetent individuals, these responses were predominantly driven by distinct COVID-19 clinical severities (97.6%, 80.5% and 42.1%, all significantly different, were seropositive; 84% vs 75% vs 35.7%, all significantly different, showed IgG-producing memory B cells and 82.5%, 86.9% and 31.6%, displayed IFN-γ producing T cells; in severe, mild and asymptomatic convalescent patients, respectively). Notably, patients with a solid organ transplant with longer time after transplantation did more likely show detectable long-lasting immune memory, regardless of COVID-19 severity. Thus, our study shows that patients with a solid organ transplant are capable of maintaining long-lasting peripheral immune memory after COVID-19 infection; mainly determined by the degree of infection severity.


Assuntos
COVID-19 , Transplante de Órgãos , Anticorpos Antivirais , Humanos , Memória Imunológica , Transplante de Órgãos/efeitos adversos , SARS-CoV-2 , Transplantados
2.
J Neurooncol ; 154(3): 353-364, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34498213

RESUMO

BACKGROUND: Amplification of EGFR and its active mutant EGFRvIII are common in glioblastoma (GB). While EGFR and EGFRvIII play critical roles in pathogenesis, targeted therapy with EGFR-tyrosine kinase inhibitors or antibodies has shown limited efficacy. To improve the likelihood of effectiveness, we targeted adult patients with recurrent GB enriched for simultaneous EGFR amplification and EGFRvIII mutation, with osimertinib/bevacizumab at doses described for non-small cell lung cancer. METHODS: We retrospectively explored whether previously described EGFRvIII mutation in association with EGFR gene amplification could predict response to osimertinib/bevacizumab combination in a subset of 15 patients treated at recurrence. The resistance pattern in a subgroup of subjects is described using a commercial next-generation sequencing panel in liquid biopsy. RESULTS: There were ten males (66.7%), and the median patient's age was 56 years (range 38-70 years). After their initial diagnosis, 12 patients underwent partial (26.7%) or total resection (53.3%). Subsequently, all cases received IMRT and concurrent and adjuvant temozolomide (TMZ; the median number of cycles 9, range 6-12). The median follow-up after recurrence was 17.1 months (95% CI 12.3-22.6). All patients received osimertinib/bevacizumab as a second-line intervention with a median progression-free survival (PFS) of 5.1 months (95% CI 2.8-7.3) and overall survival of 9.0 months (95% CI 3.9-14.0). The PFS6 was 46.7%, and the overall response rate was 13.3%. After exposure to the osimertinib/bevacizumab combination, the main secondary alterations were MET amplification, STAT3, IGF1R, PTEN, and PDGFR. CONCLUSIONS: While the osimertinib/bevacizumab combination was marginally effective in most GB patients with simultaneous EGFR amplification plus EGFRvIII mutation, a subgroup experienced a long-lasting meaningful benefit. The findings of this brief cohort justify the continuation of the research in a clinical trial. The pattern of resistance after exposure to osimertinib/bevacizumab includes known mechanisms in the regulation of EGFR, findings that contribute to the understanding and targeting in a stepwise rational this pathway.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Glioblastoma , Acrilamidas , Adulto , Idoso , Compostos de Anilina , Bevacizumab/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas , Receptores ErbB/genética , Feminino , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Humanos , Neoplasias Pulmonares , Masculino , Pessoa de Meia-Idade , Mutação , Recidiva Local de Neoplasia , Inibidores de Proteínas Quinases , Estudos Retrospectivos
3.
J Craniofac Surg ; 30(1): 244-253, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30394975

RESUMO

BACKGROUND: The accessory infraorbital foramen (AIOF) is an anatomical variation associated with the infraorbital foramen (IOF) and nerve (ION). Its occurrence and neural contents have clinical implications regarding failure of loco-regional anesthesia and risk of neural damage during surgical interventions involving the maxillary region. Thus, morphologic characterization of the AIOF and neural contents as well as the spatial relationships to the IOF are potentially useful for optimizing surgical procedures. Additionally, predictive features of the AIOF based on its relationship to IOF morphology could enable the surgeon to anticipate its presence and proceed accordingly. The purpose of this study was to determine whether the presence of an AIOF and its neural contents affected the size, shape, and composition of the IOF and ION. The specific hypothesis tested was that the topography and fascicular composition of the ION and IOF differs between individuals possessing an AIOF and those lacking this anatomical variant. METHODS: Gross topographic features of the IOF (42 crania) were compared between specimens possessing (test) or lacking (control) an AIOF. Nerve fascicles of ION (60 cadaveric sides) were examined histologically and compared morphometrically between specimens presenting or lacking an AIOF. An additional sample of 30 crania was subjected to cone-beam computed tomography (CBCT) analysis to determine the course of the canal leading to the AIOF. RESULTS: The AIOF incidence was 47.6% (20 crania) and 32.1% of the sides (27 sides). A single AIOF was observed in 24 sides and double AIOF in three sides. The AIOF occurred bilaterally in 7 specimens (16.7%). The majority of AIOF (86.7%) were located superomedial to IOF. A slightly higher frequency of the AIOF was found in left side compared to the right. Using CBCT, a patient sample showed an AIOF incidence in 21 sides of 16 patients (65.6%). A single AIOF was observed in 19 sides. Only 1 double AIOF was found in the scans, whereas 3 were found in the dry skull group. The AIOF occurred bilaterally in 3 scans (10%). The majority of AIOF (90.4%) were located superomedial to the IOF based on the CBCT scans. The AIOF was consistently seen connected to the infraorbital canal and progressed superiorly and medially from the infraorbital canal to the maxillary surface. The size of the ION without an AIOF was not significantly different than the ION in the presence of an AIOF (1.45 × 10/1.32 × 10 µm, P < 0.35) based on fascicular area. However, the number of ION fascicles was greater in specimens without an AIOF compared to those showing this feature (15.15/12.71, P < 0.04) CONCLUSION:: Results indicate that the area of the ION is not affected by an AIOF, suggesting that the field of innervation of this area is not modified by its occurrence. However, the ION appears to divide more proximally into its component branches when the AIOF is present.


Assuntos
Maxila/anatomia & histologia , Nervo Maxilar/anatomia & histologia , Órbita/inervação , Adulto , Variação Anatômica , Cadáver , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
J Am Soc Nephrol ; 27(8): 2487-94, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26647424

RESUMO

Tertiary hyperparathyroidism is a common cause of hypercalcemia after kidney transplant. We designed this 12-month, prospective, multicenter, open-label, randomized study to evaluate whether subtotal parathyroidectomy is more effective than cinacalcet for controlling hypercalcemia caused by persistent hyperparathyroidism after kidney transplant. Kidney allograft recipients with hypercalcemia and elevated intact parathyroid hormone (iPTH) concentration were eligible if they had received a transplant ≥6 months before the study and had an eGFR>30 ml/min per 1.73 m(2) The primary end point was the proportion of patients with normocalcemia at 12 months. Secondary end points were serum iPTH concentration, serum phosphate concentration, bone mineral density, vascular calcification, renal function, patient and graft survival, and economic cost. In total, 30 patients were randomized to receive cinacalcet (n=15) or subtotal parathyroidectomy (n=15). At 12 months, ten of 15 patients in the cinacalcet group and 15 of 15 patients in the parathyroidectomy group (P=0.04) achieved normocalcemia. Normalization of serum phosphate concentration occurred in almost all patients. Subtotal parathyroidectomy induced greater reduction of iPTH and associated with a significant increase in femoral neck bone mineral density; vascular calcification remained unchanged in both groups. The most frequent adverse events were digestive intolerance in the cinacalcet group and hypocalcemia in the parathyroidectomy group. Surgery would be more cost effective than cinacalcet if cinacalcet duration reached 14 months. All patients were alive with a functioning graft at the end of follow-up. In conclusion, subtotal parathyroidectomy was superior to cinacalcet in controlling hypercalcemia in these patients with kidney transplants and persistent hyperparathyroidism.


Assuntos
Calcimiméticos/uso terapêutico , Cinacalcete/uso terapêutico , Hipercalcemia/tratamento farmacológico , Hipercalcemia/cirurgia , Hiperparatireoidismo Secundário/tratamento farmacológico , Hiperparatireoidismo Secundário/cirurgia , Transplante de Rim , Paratireoidectomia , Complicações Pós-Operatórias/tratamento farmacológico , Complicações Pós-Operatórias/cirurgia , Feminino , Humanos , Hipercalcemia/etiologia , Hiperparatireoidismo Secundário/complicações , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
5.
Transplant Proc ; 54(9): 2454-2456, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36273957

RESUMO

BACKGROUND: Messenger RNA vaccination against COVID-19 has been shown to produce an immune response with sufficient efficacy to prevent natural infection in immunocompetent recipients. However, the response in kidney transplant recipients is low. We aimed to evaluate the specific humoral response to SARS-CoV-2 after vaccination in a population of kidney transplant recipients and assess the main factors associated with a lack of response. METHODS: We undertook a prospective study of 105 kidney transplant recipients and 11 recipients of a combined kidney-pancreas transplant. We analyzed immunoglobulin G and immunoglobulin M antibodies after the patients received their second and third doses of the messenger RNA 1273 (Moderna) or BNT162b1 (BionTECH-Pfizer) vaccinations between February and November 2021. RESULTS: Mean (SD) age of the 116 patients was 50 (16) years, and 65% were men. They had their transplants for 40 months (IQR, 15-123 months), with 14% undergoing retransplant and 11% sensitized. The maintenance immunosuppression regimen was steroids + tacrolimus + mycophenolate (MMF) in 68% of the patients and any combination with mammalian target of rapamycin inhibitor (mTORi) in 28%. A humoral response developed in 40% of the patients 6 weeks (IQR, 4-10 weeks) after receiving the second dose of the vaccine. Of the 67 patients with no response to the second dose, 51 had an analysis of the humoral response after the third dose, which was positive in 16 (31%). A total of 80% received the Moderna vaccine and 20% the BionTECH-Pfizer. No patient experienced major adverse effects after the vaccination. Factors associated with a lack of humoral response to the vaccine were recipient age (odds ratio [OR], 1.02; 95% CI, 1.001-1.05; P = .04), diabetes (OR, 2.8; 95% CI, 1.2-6.9; P = .02), and treatment with MMF (OR, 2.6; 95% CI, 1.08-6.8; P = .03). Treatment with mTORi was associated with a better response to vaccination (OR, 0.3; 95% CI, 0.1-0.9; P = .04). CONCLUSIONS: The humoral response to the COVID-19 vaccine in kidney transplant recipients is poor. Factors related with this lack of immunity are recipient age and diabetes, plus MMF therapy, whereas mTORi therapy was associated with a better response to vaccination.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Transplante de Rim , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Anticorpos Antivirais , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Terapia de Imunossupressão , Transplante de Rim/efeitos adversos , Estudos Prospectivos , RNA Mensageiro , SARS-CoV-2 , Transplantados , Vacinação
6.
Clin Lung Cancer ; 23(6): 522-531, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35798634

RESUMO

INTRODUCTION: Osimertinib is a third generation EGFR-TKI inhibitor approved in the first-line setting for patients with advanced non-small cell lung cancer (NSCLC). Additionally, it represents the treatment of choice in patients who present with T790M mutations and evidence of relapse of the disease. Effectiveness and safety of this drug have been studied in multiple clinical trials and observational studies, however, information regarding outcomes among Hispanic patients treated with Osimertinib is scarce. The objective of this study was to examine real-world effectiveness and safety of first-line Osimertinib in a cohort of Hispanic patients with NSCLC, emphasizing post-progression outcomes. METHODS: This is a multicenter, multinational, retrospective cohort study of Hispanic patients treated with Osimertinib as first-line for EGFR-mutated NSCLC. Patients with a confirmed diagnosis of metastatic EGFR-mutated NSCLC who received Osimertinib (80mg/day until evidence of disease progression or presence of intolerable adverse effects) were identified and included. NGS was performed in tumor samples or liquid biopsies among patients who had disease progression. The primary outcome was progression-free survival, and the secondary outcome was post-progression survival. RESULTS: A total of 94 patients from Mexico, Argentina, Costa Rica, Colombia, Panama, Chile and the USA were included, with a median age of 59 years. Identified mutations included EGFR Exon 19 deletions and EGFR pL858R point mutations. Median progression-free survival (PFS) was 14.4 months (95%CI 12.4-18.2 months). Lung/pleura and lymph nodes were the most common sites of progression. Median post-progression survival was 7.73 months (95%CI 4.07 months-Not reached). Factors which negatively affected PFS included presence of liver metastases at diagnosis and a tumor mutational burden > 5 mut/Mb. CONCLUSION: Treatment with first line osimertinib represents an effective and safe option for Hispanic patients with metastatic NSCLC. Liver metastases and a higher tumor mutation burden were associated with a lower PFS. Despite effectiveness, different mechanisms of resistance were identified among the patients in this cohort, including mutations which can be targeted by other therapeutic options.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares , Acrilamidas , Compostos de Anilina , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Progressão da Doença , Receptores ErbB/genética , Hispânico ou Latino , Humanos , Indóis , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Pessoa de Meia-Idade , Mutação/genética , Recidiva Local de Neoplasia/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas , Estudos Retrospectivos
7.
Clin Pharmacol Ther ; 110(1): 238-247, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33626199

RESUMO

Tacrolimus (Tac) is the cornerstone calcineurin inhibitor in transplantation. Extended-release Meltdose formulation (Tac-LCP) offers better bioavailability compared with immediate-release formulation (Tac-IR). We postulated that the less fluctuating pharmacokinetic (PK) profile of Tac-LCP might maintain a sustained inhibition of calcineurin activity (CNA) between dose intervals. Higher concentrations (peak plasma concentration (Cmax )) after Tac-IR may not result in a more potent CNA inhibition due to a capacity-limited effect. This study was aimed at evaluating the pharmacodynamic (PD)/PK profiles of Tac-IR compared with Tac-LCP. An open-label, prospective, nonrandomized, investigator-driven study was conducted. Twenty-five kidney transplant recipients receiving Tac-IR were switched to Tac-LCP. Before and 28 days after conversion, intensive CNA-PD and PK sampling were conducted using ultra-high-performance liquid chromatography-tandem accurate mass spectrometry. PD nonlinear mixed effects model was performed in Phoenix-WinNonlin. Statistically significant higher Cmax (P < 0.001) after Tac-IR did not result in lower CNA as compared with after Tac-LCP (P = 0.860). Tac-LCP showed a statistically more maintained CNA inhibition between dose intervals (area under the effect-time curve from 0 to 24 hours (AUE0-24h )) compared with Tac-IR, in which CNA returned to predose levels after 4 hours of drug intake (373.8 vs. 290.5 pmol RII·h/min·mg prot, Tac-LCP vs. Tac-IR; P = 0.039). No correlation was achieved between any PD and PK parameters in any formulations. Moreover, Tac concentration to elicit a 50% of the maximum response (half-maximal inhibitory concentration) was 9.24 ng/mL. The higher Cmax after Tac-IR does not result in an additional CNA inhibition compared with Tac-LCP attributable to a capacity-limited effect. Tac-LCP may represent an improvement of the PD of Tac due to the more sustained CNA inhibition during dose intervals.


Assuntos
Inibidores de Calcineurina/administração & dosagem , Imunossupressores/administração & dosagem , Transplante de Rim , Modelos Biológicos , Tacrolimo/administração & dosagem , Idoso , Área Sob a Curva , Calcineurina/efeitos dos fármacos , Calcineurina/metabolismo , Inibidores de Calcineurina/farmacocinética , Inibidores de Calcineurina/farmacologia , Cromatografia Líquida de Alta Pressão , Preparações de Ação Retardada , Feminino , Humanos , Imunossupressores/farmacocinética , Imunossupressores/farmacologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tacrolimo/farmacocinética , Tacrolimo/farmacologia , Espectrometria de Massas em Tandem
8.
J Int Adv Otol ; 15(2): 267-271, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31418717

RESUMO

OBJECTIVES: This study aimed to determine whether, in asymmetric hearing loss, the presence of an ear with a better or worse hearing threshold is related to either better or worse speech-in-noise (SiN) intelligibility. MATERIALS AND METHODS: A total of 618 subjects with different degrees of hearing loss were evaluated for their ability to understand SiN. A stepwise forward logistic regression analysis was performed to identify the factors that affect performance. The influencing factors of very high or very low performance were determined. RESULTS: Age, especially after 70 years of age, and hearing loss, especially from moderate hearing loss, negatively influence SiN intelligibility. Remarkably high intelligibility was identified in subjects with a contralateral ear presenting a better auditory threshold. CONCLUSION: Although age and hearing loss are known factors that affect SiN intelligibility, the presence of a healthy contralateral ear is presented as the first description of preservation of SiN hearing ability.


Assuntos
Compreensão/fisiologia , Perda Auditiva/fisiopatologia , Ruído , Inteligibilidade da Fala/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Audiometria de Tons Puros , Limiar Auditivo/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
Open Forum Infect Dis ; 6(6): ofz243, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31214630

RESUMO

BACKGROUND: Whether antibiotic treatment of asymptomatic bacteriuria (AB) can prevent acute graft pyelonephritis (AGP) in kidney transplant (KT) recipients has not been elucidated. METHODS: In this multicenter, open-label, nonblinded, prospective, noninferiority, randomized controlled trial, we compared antibiotic treatment with no treatment for AB in KT recipients in the first year after transplantation when urinary catheters had been removed. The primary endpoint was the occurrence of AGP. Secondary endpoints included bacteremic AGP, cystitis, susceptibility of urine isolates, graft rejection, graft function, graft loss, opportunistic infections, need for hospitalization, and mortality. RESULTS: We enrolled 205 KT recipients between 2013 and 2015. AB occurred in 41 (42.3%) and 46 (50.5%) patients in the treatment and no treatment groups, respectively. There were no differences in the primary endpoint in the intention-to-treat population (12.2% [5 of 41] in the treatment group vs 8.7% [4 of 46] in the no treatment group; risk ratio, 1.40; 95% confidence interval, 0.40-4.87) or the per-protocol population (13.8% [4 of 29] in the treatment group vs 6.7% [3 of 45] in the no treatment group; risk ratio, 2.07, 95% confidence interval, 0.50-8.58). No differences were found in secondary endpoints, except for antibiotic susceptibility. Fosfomycin (P = .030), amoxicillin-clavulanic (P < .001) resistance, and extended-spectrum ß-lactamase production (P = .044) were more common in KT recipients receiving antibiotic treatment for AB. CONCLUSIONS: Antibiotic treatment of AB was not useful to prevent AGP in KT recipients and may increase antibiotic resistance. However, our findings should be regarded with caution, due to the small sample size analyzed.

10.
Antivir Ther ; 10(1): 171-7, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15751775

RESUMO

OBJECTIVE: To describe the occurrence of a high early virological failure (VF) rate and development of resistance mutations in antiretroviral-naive patients receiving tenofovir, didanosine and efavirenz. METHODS: HIV-infected antiretroviral-naive patients with viral load > or =30 000 copies/ml were enrolled in a pilot randomized trial of tenofovir/didanosine (250 mg)/ efavirenz with (arm A) or without (arm B) lopinavir/r for the first 12 weeks. As six cases of early VF (a drop of <2 log at month 3, or a rebound of >1 log from the nadir) were detected (five in arm B and one in arm A who had previously stopped lopinavir/r) an unplanned interim analysis was performed. RESULTS: A total of 29 out of 36 enrolled patients completed at least 3 months of follow-up and were included in the interim analysis. An intent-to-treat analysis showed treatment failure in 7/15 (46.7%) patients in arm B (five VF, one lost, one switched) versus 2/14 (14.3%) in arm A (one lost, one switched) (P=0.109). The patient in arm A who interrupted lopinavir/r at day 3 and continued with tenofovir/didanosine/efavirenz later developed VF. At baseline, 6/6 VF patients had VL >100000 copies/ml and an advanced stage of disease (CD4 <200 plus CDC stage C or B3) versus 0/8 non-VF patients taking the triple drug regimen (P<0.001). At failure, G190S/E alone or associated with K103N and K101R mutations was detected in five patients, and K103N/L1001/V108l in the sixth patient. Additionally, L74V/I and K65R were detected in four and two patients, respectively. CONCLUSIONS: A high early virological failure rate and the occurrence of resistance mutations were detected in a group of antiretroviral-naive patients treated with tenofovir/didanosine/efavirenz.


Assuntos
Adenina/análogos & derivados , Adenina/administração & dosagem , Fármacos Anti-HIV/administração & dosagem , Didanosina/administração & dosagem , Infecções por HIV/tratamento farmacológico , Organofosfonatos/administração & dosagem , Oxazinas/administração & dosagem , Adulto , Idoso , Alcinos , Terapia Antirretroviral de Alta Atividade , Benzoxazinas , Ciclopropanos , Farmacorresistência Viral/genética , Feminino , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Lopinavir , Masculino , Pessoa de Meia-Idade , Mutação , Pirimidinonas/administração & dosagem , RNA Viral/sangue , Tenofovir , Fatores de Tempo , Falha de Tratamento , Viremia/tratamento farmacológico , Viremia/virologia
11.
FEMS Microbiol Lett ; 315(1): 63-71, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21175741

RESUMO

A genetic screening for osmoregulated genes allowed us to identify the yfeR gene of Salmonella enterica serovar Typhimurium. The yfeR gene product encodes a novel LysR-type transcriptional regulator (LTTR), the expression of which decreases when external osmolarity increases. Out of the adjacent gene yfeH, YfeR modulates expression of several genes that may be required for optimal growth under low osmolarity conditions.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , DNA Bacteriano/metabolismo , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Equilíbrio Hidroeletrolítico/genética , Sítios de Ligação , DNA Intergênico/genética , Regulação Bacteriana da Expressão Gênica , Mutagênese Insercional , Ligação Proteica
12.
J Med Virol ; 78(10): 1271-5, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16927288

RESUMO

The human polyomavirus JC (JCV) is the causative agent of progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system (CNS). JCV has a hyper-variable non-coding transcriptional control region (TCR), which contains the origin of replication and the promoters of viral transcription and replication. The archetype form of TCR-JCV is frequently found in the urine and kidneys of healthy and immunocompromised subjects. However, the rearranged forms, possibly generated by deletion and duplication of segments of the archetype sequence, are found in the peripheral blood, cerebrospinal fluid (CSF), and brain of PML patients. Most experience on this setting has come from the human immunodeficiency virus (HIV) pandemic. Little has been described on the JCV-TCR sequences from PML-HIV-negative patients affected by other immunosuppressive disorders. The aim of this study was to analyze the JCV-TCR detected in CSF samples from 12 HIV-negative immunosuppressed patients suffering from PML and to investigate the possible role of genomic organization in the different incidences of PML in HIV-positive and HIV-negative patients. The results confirm that the JCV-TCR rearrangements play a crucial role in the development of PML, although they do not account for the higher frequency of the disease in HIV infection. These data support the hypothesis that, independently of the rearrangement patterns of JCV-TCR, the direct action of HIV together with other as yet unidentified cellular determinants can be a key to explaining the high rate of PML in HIV infection with respect to other underlying immunosuppressive conditions.


Assuntos
Vírus JC/genética , Leucoencefalopatia Multifocal Progressiva/virologia , Transplante de Medula Óssea/imunologia , Rearranjo Gênico , Soronegatividade para HIV , Humanos , Hidroxicorticosteroides/efeitos adversos , Hospedeiro Imunocomprometido/efeitos dos fármacos , Transplante de Rim/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Leucoencefalopatia Multifocal Progressiva/líquido cefalorraquidiano , Leucoencefalopatia Multifocal Progressiva/imunologia , Linfoma não Hodgkin/imunologia , Transcrição Gênica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA