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1.
Ann Hepatol ; 28(4): 101097, 2023.
Article in English | MEDLINE | ID: mdl-37030570

ABSTRACT

INTRODUCTION AND OBJECTIVES: there is insufficient data regarding bacterial infections in patients with cirrhosis to support recommendations for empiric antibiotic treatments, particularly in Latin America. This study aimed to evaluate bacterial infection's clinical impact and microbiological characteristics, intending to serve as a platform to revise current practices. MATERIALS AND METHODS: multicenter prospective cohort study of patients with cirrhosis and bacterial infections from Argentina and Uruguay. Patient and infection-related information were collected, focusing on microbiology, antibiotic susceptibility patterns, and outcomes. RESULTS: 472 patients were included. Spontaneous bacterial infections and urinary tract infections (UTIs) were registered in 187 (39.6%) and 116 (24.6%) patients, respectively, representing the most common infections. Of the 256 culture-positive infections, 103 (40.2%) were caused by multidrug-resistant organisms (reaching 50% for UTI), and 181 (70.7%) received adequate initial antibiotic treatment. The coverage of cefepime and ceftriaxone was over 70% for the empirical treatment of community-acquired spontaneous infections, but ceftazidime´s coverage was only 40%. For all UTI cases and for healthcare-associated or nosocomial spontaneous bacterial infections, the lower-spectrum antibiotics that covered at least 70% of the isolations were imipenem and meropenem. During hospitalization, a second bacterial infection was diagnosed in 9.8% of patients, 23.9% required at least one organ support, and 19.5% died. CONCLUSIONS: short-term mortality of bacterial infections in patients with cirrhosis is very high, and a high percentage were caused by multidrug-resistant organisms, particularly in UTIs. The information provided might serve to adapt recommendations, particularly related to empirical antibiotic treatment in Argentina and Uruguay. The study was registered in Clinical Trials (NCT03919032).


Subject(s)
Bacterial Infections , Community-Acquired Infections , Cross Infection , Urinary Tract Infections , Humans , Prospective Studies , Argentina/epidemiology , Uruguay/epidemiology , Bacterial Infections/diagnosis , Bacterial Infections/drug therapy , Bacterial Infections/epidemiology , Anti-Bacterial Agents/therapeutic use , Liver Cirrhosis/complications , Liver Cirrhosis/diagnosis , Liver Cirrhosis/drug therapy , Urinary Tract Infections/diagnosis , Urinary Tract Infections/drug therapy , Urinary Tract Infections/epidemiology , Bacteria , Cross Infection/diagnosis , Cross Infection/drug therapy , Cross Infection/epidemiology , Community-Acquired Infections/drug therapy
2.
Eur J Clin Microbiol Infect Dis ; 42(4): 481-491, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36820931

ABSTRACT

It is unclear whether norfloxacin predisposes to infections by multidrug-resistant organisms (MDROs). We aimed to evaluate if patients with cirrhosis receiving norfloxacin prophylaxis at the time of the diagnosis of bacterial infections were more likely to present a multidrug-resistant isolate than those without prophylaxis. This is a cross-sectional study of hospitalized patients with cirrhosis and bacterial infections from Argentina and Uruguay (NCT03919032) from September 2018 to December 2020. The outcome variable was a multidrug-resistant bacterial infection. We used inverse probability of treatment weighting to estimate the odds ratio (OR) of norfloxacin on infection caused by MDROs considering potential confounders. Among the 472 patients from 28 centers, 53 (11%) were receiving norfloxacin at the time of the bacterial infection. Patients receiving norfloxacin had higher MELD-sodium, were more likely to have ascites or encephalopathy, to receive rifaximin, beta-blockers, and proton-pump inhibitors, to have a nosocomial or health-care-associated infection, prior bacterial infections, admissions to critical care units or invasive procedures, and to be admitted in a liver transplant center. In addition, we found that 13 (24.5%) patients with norfloxacin and 90 (21.5%) of those not receiving it presented infections caused by MDROs (adjusted OR 1.55; 95% CI: 0.60-4.03; p = 0.360). The use of norfloxacin prophylaxis at the time of the diagnosis of bacterial infections was not associated with multidrug resistance. These results help empiric antibiotic selection and reassure the current indication of norfloxacin prophylaxis in well-selected patients.Study registration number: NCT03919032.


Subject(s)
Bacterial Infections , Peritonitis , Humans , Norfloxacin/therapeutic use , Cross-Sectional Studies , Bacterial Infections/drug therapy , Bacterial Infections/prevention & control , Bacterial Infections/microbiology , Anti-Bacterial Agents/therapeutic use , Liver Cirrhosis/complications , Liver Cirrhosis/microbiology , Peritonitis/microbiology , Drug Resistance, Multiple , Antibiotic Prophylaxis/adverse effects
3.
Liver Int ; 42(8): 1891-1901, 2022 08.
Article in English | MEDLINE | ID: mdl-35608939

ABSTRACT

BACKGROUND & AIMS: Information about the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with liver cancer is lacking. This study characterizes the outcomes and mortality risk in this population. METHODS: Multicentre retrospective, cross-sectional, international study of liver cancer patients with SARS-CoV-2 infection registered between February and December 2020. Clinical data at SARS-CoV-2 diagnosis and outcomes were registered. RESULTS: Two hundred fifty patients from 38 centres were included, 218 with hepatocellular carcinoma (HCC) and 32 with intrahepatic cholangiocarcinoma (iCCA). The median age was 66.5 and 64.5 years, and 84.9% and 21.9% had cirrhosis in the HCC and iCCA cohorts respectively. Patients had advanced cancer stage at SARS-CoV-2 diagnosis in 39.0% of the HCC and 71.9% of the iCCA patients. After a median follow-up of 7.20 (IQR: 1.84-11.24) months, 100 (40%) patients have died, 48% of the deaths were SARS-CoV-2-related. Forty (18.4%) HCC patients died within 30-days. The death rate increase was significantly different according to the BCLC stage (6.10% [95% CI 2.24-12.74], 11.76% [95% CI 4.73-22.30], 20.69% [95% CI 11.35-31.96] and 34.52% [95% CI 17.03-52.78] for BCLC 0/A, B, C and D, respectively; p = .0017). The hazard ratio was 1.45 (95% CI 0.49-4.31; p = .5032) in BCLC-B versus 0/A, and 3.13 (95% CI 1.29-7.62; p = .0118) in BCLC-C versus 0/A in the competing risk Cox regression model. Nineteen out of 32 iCCA (59.4%) died, and 12 deaths were related to SARS-CoV-2 infection. CONCLUSIONS: This is the largest cohort of liver cancer patients infected with SARS-CoV-2. It characterizes the 30-day mortality risk of SARS-CoV-2 infected patients with HCC during this period.


Subject(s)
COVID-19 , Carcinoma, Hepatocellular , Liver Neoplasms , COVID-19/complications , COVID-19 Testing , Cohort Studies , Cross-Sectional Studies , Humans , Retrospective Studies , SARS-CoV-2
4.
Medicina (B Aires) ; 76(4): 208-12, 2016.
Article in Spanish | MEDLINE | ID: mdl-27576278

ABSTRACT

Relative adrenal insufficiency (RAI) is a common finding in cirrhotic patients with severe sepsis, and increased mortality. Its significance is unknown in stable conditions. The aim of this study was to evaluate the prevalence of RAI in stable cirrhotic patients at different stages of the disease. Also, the impact of RAI on the survival was evaluated and basal cortisol levels between plasma and saliva was correlated in control subjects and cirrhotic patients. Forty seven ambulatory patients and 16 control subjects were studied. RAI was defined as a serum cortisol increase of less than 9 υg/dl from baseline after the stimulation with 250 mg of synthetic ACTH. Twenty two had Child-Pugh = 8 and 25 = 9. The prevalence of RAI in patients with stable cirrhosis was 22%. A higher incidence of RAI was observed in patients with a Child-Pugh = 9 (8/32) than in those with = 8 (3/13, p < 0.05). A correlation between salivary cortisol and basal plasma cortisol (r = 0.6, p < 0.0004) was observed. Finally, survival at 1 year (97%) and 3 years (91%) was significantly higher without RAI than those who developed this complication (79% and 51%, p < 0.05, respectively). In summary, the prevalence of RAI is frequent in patients with stable cirrhosis and that it is related to the severity of liver diseaseand increased mortality.


Subject(s)
Adrenal Insufficiency/epidemiology , Liver Cirrhosis/complications , Adrenal Insufficiency/mortality , Case-Control Studies , Female , Humans , Hydrocortisone/analysis , Hydrocortisone/blood , Hypothalamo-Hypophyseal System/metabolism , Liver/physiopathology , Liver Cirrhosis/metabolism , Liver Cirrhosis/mortality , Male , Middle Aged , Pituitary-Adrenal System/metabolism , Prevalence , Prognosis , Prospective Studies , Saliva/chemistry , Sepsis
5.
Medicina (B.Aires) ; 76(4): 208-212, Aug. 2016. graf, tab
Article in Spanish | LILACS | ID: biblio-841578

ABSTRACT

La insuficiencia suprarrenal relativa (ISR) es frecuente en pacientes cirróticos con sepsis grave, asociándose a un pobre pronóstico. Se desconoce su importancia en condiciones de enfermedad estable. El objetivo del trabajo ha sido evaluar la prevalencia de la ISR en una serie de pacientes cirróticos estables y su relación con el deterioro de la función hepática. Se determinó el impacto de la ISR en la supervivencia y se correlacionaron los niveles entre el cortisol basal en plasma y saliva en sujetos controles y cirróticos. Fueron incluidos 47 pacientes ambulatorios y 16 controles. La funcionalidad del eje hipotalámico-pituitario-suprarrenal se valoró mediante la prueba de estimulación con 250 μg de ACTH sintética EV, definiendo la ISR como delta cortisol < 9 μg/dl. Respecto al grado de deterioro de la función hepática, 22 tenían un Child-Pugh ≤ 8 y 25 pacientes = 9. La prevalencia de ISR fue de un 22%, siendo significativamente más elevada en aquellos con mayor deterioro de la función hepática (8/32 vs. 3/13, p < 0.05). Se observó correlación entre el cortisol salival y el plasmático basal (r = 0.6, p < 0.0004). Por último, la supervivencia fue más elevada en los pacientes sin ISR al año (97%) y a los tres años (91%) que aquellos que desarrollaron esta complicación (79 % y 51%, p < 0.05, respectivamente). En resumen, la prevalencia de ISR es elevada en los pacientes con cirrosis estable y se relaciona con un deterioro de la función hepática y una mayor mortalidad.


Relative adrenal insufficiency (RAI) is a common finding in cirrhotic patients with severe sepsis, and increased mortality. Its significance is unknown in stable conditions. The aim of this study was to evaluate the prevalence of RAI in stable cirrhotic patients at different stages of the disease. Also, the impact of RAI on the survival was evaluated and basal cortisol levels between plasma and saliva was correlated in control subjects and cirrhotic patients. Forty seven ambulatory patients and 16 control subjects were studied. RAI was defined as a serum cortisol increase of less than 9 μg/dl from baseline after the stimulation with 250 mg of synthetic ACTH. Twenty two had Child-Pugh ≤ 8 and 25 = 9. The prevalence of RAI in patients with stable cirrhosis was 22%. A higher incidence of RAI was observed in patients with a Child-Pugh = 9 (8/32) than in those with ≤ 8 (3/13, p < 0.05). A correlation between salivary cortisol and basal plasma cortisol (r = 0.6, p < 0.0004) was observed. Finally, survival at 1 year (97%) and 3 years (91%) was significantly higher without RAI than those who developed this complication (79% and 51%, p < 0.05, respectively). In summary, the prevalence of RAI is frequent in patients with stable cirrhosis and that it is related to the severity of liver diseaseand increased mortality.


Subject(s)
Humans , Male , Female , Middle Aged , Adrenal Insufficiency/epidemiology , Liver Cirrhosis/complications , Pituitary-Adrenal System/metabolism , Prognosis , Saliva/chemistry , Hydrocortisone/analysis , Hydrocortisone/blood , Case-Control Studies , Prevalence , Prospective Studies , Adrenal Insufficiency/mortality , Sepsis , Hypothalamo-Hypophyseal System/metabolism , Liver/physiopathology , Liver Cirrhosis/metabolism , Liver Cirrhosis/mortality
6.
Gastroenterol. hepatol. (Ed. impr.) ; 38(7): 431-435, ago.-sept. 2015. tab, ilus
Article in English | IBECS | ID: ibc-141753

ABSTRACT

Introduction: The introduction of noninvasive liver stiffness (LS) determination has heralded a new stage in the diagnosis and treatment of liver fibrosis. Aim: We evaluated the effect of food intake on LS in patients with different degrees of liver disease. Patients and methods: We evaluated 24 patients (F≤1, n = 11 and F> 1, n = 13). LS (Fibroscan®) and portal blood flow (PBF) (Doppler ultrasound) were studied before and 30 min after ingestion of a standard liquid meal. Results: Food intake increased PBF (51 ± 10%, p < 0.001). Splanchnic hyperemia was accompanied by a significant rise in LS (from 7.8 ± 3.3 to 10.3 ± 4.1 kPa, p < 0.001). These increases were similar in patients with minimal fibrosis(F≤1) and in those with more advanced fibrosis or cirrhosis (F > 1). Hemodynamic and LS values returned to baseline pre-meal levels within 2 hours. Conclusion: LS increases markedly after ingestion of a standard meal, irrespective of the degree of fibrosis. Our results strongly suggest that LS should be measured in fasting conditions (AU)


Introducción: El desarrollo de nuevos métodos que permiten la determinación no invasiva de la rigidez hepática ha abierto una nueva era en el manejo de la fibrosis hepática. Objetivo: El objetivo del trabajo fue evaluar el efecto de ingesta de una comida sobre la rigidez hepática en pacientes con diferentes grados de fibrosis. Pacientes y métodos: Se evaluaron 24 pacientes (F ≤ 1, n = 11, y F > 1, n = 13), que fueron estudiados basalmente y 30 min después de la ingesta de una comida estándar (Ensure Plus®). La rigidez hepática se midió por Fibroscan®, y los parámetros hemodinámicos portales, mediante Doppler. La ingesta de una comida ocasionó un aumento del flujo sanguíneo portal (51 ± 10%, p < 0,001). La hiperemia esplácnica fue acompañada por un marcado incremento en la rigidez hepática (7,8 ± 3,3 a 10,3 ± 4,1 kPa, p < 0,001). Este efecto fue similar en pacientes con fibrosis mínima (F ≤ 1) y con fibrosis significativa (F > 1). Los valores de ambos parámetros retornaron a niveles similares a los basales a las 2 h luego de la ingesta. Conclusión: Este estudio demuestra que la respuesta vascular posprandial se acompaña de aumento de la rigidez hepática. Los cambios son independientes del grado de fibrosis. Nuestros resultados sugieren fuertemente que los estudios deben realizarse en condiciones de ayuno (AU)


Subject(s)
Humans , Eating/physiology , Liver Cirrhosis/physiopathology , Fasting/physiology , Hyperemia/physiopathology , Fibrosis , Ultrasonography, Doppler , Postprandial Period/physiology
7.
Nat Commun ; 6: 6461, 2015 Mar 09.
Article in English | MEDLINE | ID: mdl-25751579

ABSTRACT

HIV protease (PR) is required for proteolytic maturation in the late phase of HIV replication and represents a prime therapeutic target. The regulation and kinetics of viral polyprotein processing and maturation are currently not understood in detail. Here we design, synthesize, validate and apply a potent, photodegradable HIV PR inhibitor to achieve synchronized induction of proteolysis. The compound exhibits subnanomolar inhibition in vitro. Its photolabile moiety is released on light irradiation, reducing the inhibitory potential by 4 orders of magnitude. We determine the structure of the PR-inhibitor complex, analyze its photolytic products, and show that the enzymatic activity of inhibited PR can be fully restored on inhibitor photolysis. We also demonstrate that proteolysis of immature HIV particles produced in the presence of the inhibitor can be rapidly triggered by light enabling thus to analyze the timing, regulation and spatial requirements of viral processing in real time.


Subject(s)
Aminocoumarins/pharmacology , Carbamates/pharmacology , HIV Protease Inhibitors/pharmacology , HIV Protease/chemistry , HIV-1/drug effects , Protein Precursors/antagonists & inhibitors , Valine/analogs & derivatives , Aminocoumarins/chemical synthesis , Binding Sites , Carbamates/chemical synthesis , HEK293 Cells , HIV Protease/metabolism , HIV Protease Inhibitors/chemical synthesis , HIV-1/physiology , HIV-1/radiation effects , Humans , Kinetics , Light , Models, Molecular , Photolysis , Protein Binding , Protein Precursors/chemistry , Protein Precursors/metabolism , Proteolysis/drug effects , Time Factors , Valine/chemical synthesis , Valine/pharmacology , Virus Replication
8.
Gastroenterol Hepatol ; 38(7): 431-5, 2015.
Article in English | MEDLINE | ID: mdl-25769876

ABSTRACT

INTRODUCTION: The introduction of noninvasive liver stiffness (LS) determination has heralded a new stage in the diagnosis and treatment of liver fibrosis. AIM: We evaluated the effect of food intake on LS in patients with different degrees of liver disease. PATIENTS AND METHODS: We evaluated 24 patients (F≤1, n=11 and F> 1, n=13). LS (Fibroscan®) and portal blood flow (PBF) (Doppler ultrasound) were studied before and 30min after ingestion of a standard liquid meal. RESULTS: Food intake increased PBF (51±10%, p<0.001). Splanchnic hyperemia was accompanied by a significant rise in LS (from 7.8±3.3 to 10.3±4.1kPa, p<0.001). These increases were similar in patients with minimal fibrosis(F≤1) and in those with more advanced fibrosis or cirrhosis (F>1). Hemodynamic and LS values returned to baseline pre-meal levels within 2hours. CONCLUSION: LS increases markedly after ingestion of a standard meal, irrespective of the degree of fibrosis. Our results strongly suggest that LS should be measured in fasting conditions.


Subject(s)
Eating/physiology , Fasting/physiology , Liver Cirrhosis/diagnostic imaging , Liver/physiopathology , Adult , Aged , Clinical Decision-Making , Elasticity , Female , Hemodynamics , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/diagnostic imaging , Humans , Hyperemia/etiology , Laser-Doppler Flowmetry , Liver Circulation , Liver Cirrhosis/etiology , Male , Meals , Middle Aged , Prospective Studies , Splanchnic Circulation , Ultrasonography, Doppler
9.
J Virol ; 88(24): 13956-70, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25253335

ABSTRACT

UNLABELLED: Cytoplasmic entry of HIV-1 requires binding of the viral glycoproteins to the cellular receptor and coreceptor, leading to fusion of viral and cellular membranes. Early studies suggested that productive HIV-1 infection occurs by direct fusion at the plasma membrane. Endocytotic uptake of HIV-1 was frequently observed but was considered to constitute an unspecific dead-end pathway. More recent evidence suggested that endocytosis contributes to productive HIV-1 entry and may even represent the predominant or exclusive route of infection. We have analyzed HIV-1 binding, endocytosis, cytoplasmic entry, and infection in T-cell lines and in primary CD4(+) T cells. Efficient cell binding and endocytosis required viral glycoproteins and CD4, but not the coreceptor. The contribution of endocytosis to cytoplasmic entry and infection was assessed by two strategies: (i) expression of dominant negative dynamin-2 was measured and was found to efficiently block HIV-1 endocytosis but to not affect fusion or productive infection. (ii) Making use of the fact that HIV-1 fusion is blocked at temperatures below 23 °C, cells were incubated with HIV-1 at 22 °C for various times, and endocytosis was quantified by parallel analysis of transferrin and fluorescent HIV-1 uptake. Subsequently, entry at the plasma membrane was blocked by high concentrations of the peptidic fusion inhibitor T-20, which does not reach previously endocytosed particles. HIV-1 infection was scored after cells were shifted to 37 °C in the presence of T-20. These experiments revealed that productive HIV-1 entry occurs predominantly at the plasma membrane in SupT1-R5, CEM-ss, and primary CD4(+) T cells, with little, if any, contribution coming from endocytosed virions. IMPORTANCE: HIV-1, like all enveloped viruses, reaches the cytoplasm by fusion of the viral and cellular membranes. Many viruses enter the cytoplasm by endosomal uptake and fusion from the endosome, while cell entry can also occur by direct fusion at the plasma membrane in some cases. Conflicting evidence regarding the site of HIV-1 fusion has been reported, with some studies claiming that fusion occurs predominantly at the plasma membrane, while others have suggested predominant or even exclusive fusion from the endosome. We have revisited HIV-1 entry using a T-cell line that exhibits HIV-1 endocytosis dependent on the viral glycoproteins and the cellular CD4 receptor; results with this cell line were confirmed for another T-cell line and primary CD4(+) T cells. Our studies show that fusion and productive entry occur predominantly at the plasma membrane, and we conclude that endocytosis is dispensable for HIV-1 infectivity in these T-cell lines and in primary CD4(+) T cells.


Subject(s)
CD4-Positive T-Lymphocytes/virology , Cell Membrane/virology , Endocytosis , HIV-1/physiology , Virus Internalization , Cells, Cultured , Humans , Temperature
10.
J Virol ; 88(23): 13722-31, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25231305

ABSTRACT

UNLABELLED: HIV-1 assembles at the plasma membrane of virus-producing cells as an immature, noninfectious particle. Processing of the Gag and Gag-Pol polyproteins by the viral protease (PR) activates the viral enzymes and results in dramatic structural rearrangements within the virion--termed maturation--that are a prerequisite for infectivity. Despite its fundamental importance for viral replication, little is currently known about the regulation of proteolysis and about the dynamics and structural intermediates of maturation. This is due mainly to the fact that HIV-1 release and maturation occur asynchronously both at the level of individual cells and at the level of particle release from a single cell. Here, we report a method to synchronize HIV-1 proteolysis in vitro based on protease inhibitor (PI) washout from purified immature virions, thereby temporally uncoupling virus assembly and maturation. Drug washout resulted in the induction of proteolysis with cleavage efficiencies correlating with the off-rate of the respective PR-PI complex. Proteolysis of Gag was nearly complete and yielded the correct products with an optimal half-life (t(1/2)) of ~5 h, but viral infectivity was not recovered. Failure to gain infectivity following PI washout may be explained by the observed formation of aberrant viral capsids and/or by pronounced defects in processing of the reverse transcriptase (RT) heterodimer associated with a lack of RT activity. Based on our results, we hypothesize that both the polyprotein processing dynamics and the tight temporal coupling of immature particle assembly and PR activation are essential for correct polyprotein processing and morphological maturation and thus for HIV-1 infectivity. IMPORTANCE: Cleavage of the Gag and Gag-Pol HIV-1 polyproteins into their functional subunits by the viral protease activates the viral enzymes and causes major structural rearrangements essential for HIV-1 infectivity. This proteolytic maturation occurs concomitant with virus release, and investigation of its dynamics is hampered by the fact that virus populations in tissue culture contain particles at all stages of assembly and maturation. Here, we developed an inhibitor washout strategy to synchronize activation of protease in wild-type virus. We demonstrated that nearly complete Gag processing and resolution of the immature virus architecture are accomplished under optimized conditions. Nevertheless, most of the resulting particles displayed irregular morphologies, Gag-Pol processing was not faithfully reconstituted, and infectivity was not recovered. These data show that HIV-1 maturation is sensitive to the dynamics of processing and also that a tight temporal link between virus assembly and PR activation is required for correct polyprotein processing.


Subject(s)
HIV-1/physiology , Human Immunodeficiency Virus Proteins/metabolism , Protein Processing, Post-Translational , Virology/methods , Virus Assembly , Virus Release , Humans , Proteolysis
11.
PLoS One ; 9(6): e99504, 2014.
Article in English | MEDLINE | ID: mdl-24915417

ABSTRACT

Human immunodeficiency virus particles undergo a step of proteolytic maturation, in which the main structural polyprotein Gag is cleaved into its mature subunits matrix (MA), capsid (CA), nucleocapsid (NC) and p6. Gag proteolytic processing is accompanied by a dramatic structural rearrangement within the virion, which is necessary for virus infectivity and has been proposed to proceed through a sequence of dissociation and reformation of the capsid lattice. Morphological maturation appears to be tightly regulated, with sequential cleavage events and two small spacer peptides within Gag playing important roles by regulating the disassembly of the immature capsid layer and formation of the mature capsid lattice. In order to measure the influence of individual Gag domains on lattice stability, we established Förster's resonance energy transfer (FRET) reporter virions and employed rapid kinetic FRET and light scatter measurements. This approach allowed us to measure dissociation properties of HIV-1 particles assembled in eukaryotic cells containing Gag proteins in different states of proteolytic processing. While the complex dissociation behavior of the particles prevented an assignment of kinetic rate constants to individual dissociation steps, our analyses revealed characteristic differences in the dissociation properties of the MA layer dependent on the presence of additional domains. The most striking effect observed here was a pronounced stabilization of the MA-CA layer mediated by the presence of the 14 amino acid long spacer peptide SP1 at the CA C-terminus, underlining the crucial role of this peptide for the resolution of the immature particle architecture.


Subject(s)
HIV-1/metabolism , Proteolysis , Virion/metabolism , gag Gene Products, Human Immunodeficiency Virus/metabolism , Detergents/pharmacology , Fluorescence Resonance Energy Transfer , Humans , Kinetics , Light , Proteolysis/drug effects , Scattering, Radiation , Virion/drug effects
12.
Acta Gastroenterol Latinoam ; 44(3): 239-42, 2014.
Article in English | MEDLINE | ID: mdl-26742296

ABSTRACT

Pancreatic panniculitis is an uncommon condition that can occur in association with pancreatic disease. Most of the cases reported to date were associated with acute or chronic pancreatitis and pancreas cancer. Recently, development has been described in kidney transplant patients and secondarily to allograft pancreatitis in a pancreas-kidney transplant recipient. Both findings suggest that immunological processes may be involved in the pathogenesis of this entity. We report for the first time a case of acute pancreatitis associated with pancreatic panniculitis in a patient who underwent a liver transplant 10 months before. A 69-year-old man with a history of epigastric pain of a few days of evolution was presented with painful subcutaneous nodules on both legs. Blood chemistry showed raised serum amylase and lipase levels. Ultrasonography and multislice CT scan were suggestive of an acute pancreatitis. A skin biopsy showed typical features of pancreatic panniculitis which included lobular panniculitis with lipocyte degeneration with ghost cells. The administration of octreotide resulted in both a rapid improvement of symptoms and a disappearance of skin lesions. Liver transplant specialists should be aware that the pancreatic panniculitis could be a manifestation ofpancreas disease in patients who have undergone l ver transplantation.


Subject(s)
Liver Transplantation/adverse effects , Pancreatitis/etiology , Panniculitis, Nodular Nonsuppurative/etiology , Acute Disease , Aged , Amylases/blood , Humans , Immunosuppression Therapy/adverse effects , Lipase/blood , Male , Pancreatitis/pathology , Panniculitis, Nodular Nonsuppurative/pathology , Skin/pathology
13.
Acta Gastroenterol Latinoam ; 43(2): 121-5, 2013 Jun.
Article in Spanish | MEDLINE | ID: mdl-23940912

ABSTRACT

The present study reports the effectiveness of the association of a single dose of hepatitis B immunoglobulin (HBIg) associated to entecavir in the prophylaxis of hepatitis B in patients who have undergone liver transplantation. Six patients that had been transplanted because of hepatitis B liver disease were retrospectively evaluated. Three of them developed non-oncological complications related to liver cirrhosis, two had hepatocellular carcinoma and another one had fulminant HBV hepatitis. The mean follow-up was 22 months (range: 7-52 months). The 6 patients received entecavir as prophylactic treatment before transplantation. The pretransplant viral load was undetectable in all patients. HBsAg seroconversion was observed in four of the six patients. Three patients died during follow-up, two because of recurrent hepatocellular carcinoma, none of them had detectable HBV serum viral load. In a small series of patients we could demonstrate that a regimen with a single dose of gamma globulin entecavir is effective in the post-transplant management of patients with liver disease associated with HBV. Future studies will be able to demonstrate the effectiveness of specific gamma globulin-free regimens.


Subject(s)
Antiviral Agents/administration & dosage , Guanine/analogs & derivatives , Hepatitis B/prevention & control , Immunoglobulins/administration & dosage , Liver Cirrhosis/surgery , Liver Transplantation , Adult , Aged , Argentina , Drug Therapy, Combination , Female , Guanine/administration & dosage , Humans , Liver Cirrhosis/virology , Male , Middle Aged , Retrospective Studies , Secondary Prevention
14.
Gastroenterol. hepatol. (Ed. impr.) ; 36(1): 1-6, ene. 2013. ilus, tab
Article in Spanish | IBECS | ID: ibc-109242

ABSTRACT

Introducción El objetivo del presente trabajo ha sido investigar el impacto del Model for End-stage Liver Disease(MELD) en los costes del trasplante. Material y métodos Se incluyeron todos los pacientes que recibieron un trasplante hepático por una enfermedad hepática terminal entre 2006 y 2010. El período de estudio incluye desde el día del trasplante hasta el alta hospitalaria. Los pacientes fueron categorizados en 2 grupos: 6 a 19 y 20 a 40. En forma arbitraria se definió como alto coste aquel que excedía el percentil 85. Se analizaron 77 pacientes. Resultados La media del puntaje MELD al momento del trasplante fue 19,2±7,0 (media ± DE). La media de los costes por trasplante en el período mencionado fue de 33.461 USD por paciente (rango 21.795-104.629). El coste del trasplante en los pacientes que tenían un valor de MELD de 6-19 fue de 30.493±8.825 USD y en aquellos con un MELD de 20-40, de 36.506±15.833 USD, siendo esta diferencia estadísticamente significativa (p=0,04). En un análisis escalonado por regresión logística, tener un puntaje MELD 20 fue el único predictor independiente de alto coste (OR 11,8; CI 1,6-87). En el modelo de regresión lineal, el tiempo de estancia hospitalaria fue el predictor más relevante de coste (r2=43%).Discusión Nuestros resultados demuestran que el MELD tiene un impacto directo en el coste del trasplante. Sugerimos que los sistemas de reembolso deberían compensar a los diferentes prestadores en relación a la gravedad de la patología de base, evaluada mediante el modelo MELD (AU)


Introduction The aim of the present study was to investigate the impact of the Model for End-stage Liver Disease (MELD) on transplantation costs. Material and methods We included all patients who received a liver transplant for end-stage liver disease between 2006 and 2010. The study period encompassed the day of transplantation until hospital discharge. The patients were classified into two groups: those with a MELD score of 6-19 and those with a score of 20-40.ResultsThe mean MELD score at transplantation was 19.2±7.0 (mean±SD). The mean cost per procedure in the study period was USD 33,461 per patient (range 21,795-104,629). The cost of transplantation was USD 30,493±8,825 in patients with a MELD score of 6-19 and was USD 36,506±15,833 in those with a score of 20-40; this difference was statistically significant (P=.04). In a stepwise logistic regression analysis, the only independent predictor of high cost was having a MELD score of 20 (OR 11.8; CI 1.6-87). In the linear regression model, the most important predictor of cost was the length of hospital stay (r2=43%).Discussion Our results demonstrate that the MELD score directly affects transplantation costs. We suggest that reimbursement systems compensate the distinct financing bodies according to the severity of the underlying disease, evaluated with the MELD(AU)


Subject(s)
Humans , Liver Transplantation/economics , /statistics & numerical data , End Stage Liver Disease/surgery , Hospitals, Community/statistics & numerical data , Economics, Hospital/organization & administration , Severity of Illness Index
15.
Gastroenterol Hepatol ; 36(1): 1-6, 2013 Jan.
Article in Spanish | MEDLINE | ID: mdl-23123035

ABSTRACT

INTRODUCTION: The aim of the present study was to investigate the impact of the Model for End-stage Liver Disease (MELD) on transplantation costs. MATERIAL AND METHODS: We included all patients who received a liver transplant for end-stage liver disease between 2006 and 2010. The study period encompassed the day of transplantation until hospital discharge. The patients were classified into two groups: those with a MELD score of 6-19 and those with a score of 20-40. RESULTS: The mean MELD score at transplantation was 19.2±7.0 (mean±SD). The mean cost per procedure in the study period was USD 33,461 per patient (range 21,795-104,629). The cost of transplantation was USD 30,493±8,825 in patients with a MELD score of 6-19 and was USD 36,506±15,833 in those with a score of 20-40; this difference was statistically significant (P=.04). In a stepwise logistic regression analysis, the only independent predictor of high cost was having a MELD score of 20 (OR 11.8; CI 1.6-87). In the linear regression model, the most important predictor of cost was the length of hospital stay (r(2)=43%). DISCUSSION: Our results demonstrate that the MELD score directly affects transplantation costs. We suggest that reimbursement systems compensate the distinct financing bodies according to the severity of the underlying disease, evaluated with the MELD.


Subject(s)
End Stage Liver Disease , Liver Transplantation/economics , Models, Statistical , Adolescent , Adult , Aged , Child , Costs and Cost Analysis , Female , Hospitals, Community , Humans , Male , Middle Aged , Prognosis , Severity of Illness Index , Young Adult
16.
Acta gastroenterol. latinoam ; 43(2): 121-5, 2013 Jun.
Article in Spanish | LILACS, BINACIS | ID: biblio-1157368

ABSTRACT

The present study reports the effectiveness of the association of a single dose of hepatitis B immunoglobulin (HBIg) associated to entecavir in the prophylaxis of hepatitis B in patients who have undergone liver transplantation. Six patients that had been transplanted because of hepatitis B liver disease were retrospectively evaluated. Three of them developed non-oncological complications related to liver cirrhosis, two had hepatocellular carcinoma and another one had fulminant HBV hepatitis. The mean follow-up was 22 months (range: 7-52 months). The 6 patients received entecavir as prophylactic treatment before transplantation. The pretransplant viral load was undetectable in all patients. HBsAg seroconversion was observed in four of the six patients. Three patients died during follow-up, two because of recurrent hepatocellular carcinoma, none of them had detectable HBV serum viral load. In a small series of patients we could demonstrate that a regimen with a single dose of gamma globulin entecavir is effective in the post-transplant management of patients with liver disease associated with HBV. Future studies will be able to demonstrate the effectiveness of specific gamma globulin-free regimens.


Subject(s)
Antiviral Agents/administration & dosage , Liver Cirrhosis/surgery , Guanine/analogs & derivatives , Hepatitis B/prevention & control , Immunoglobulins/administration & dosage , Liver Transplantation , Adult , Argentina , Liver Cirrhosis/virology , Retrospective Studies , Female , Guanine/administration & dosage , Humans , Aged , Male , Middle Aged , Secondary Prevention , Drug Therapy, Combination
17.
Acta Gastroenterol. Latinoam. ; 43(2): 121-5, 2013 Jun.
Article in Spanish | BINACIS | ID: bin-132990

ABSTRACT

The present study reports the effectiveness of the association of a single dose of hepatitis B immunoglobulin (HBIg) associated to entecavir in the prophylaxis of hepatitis B in patients who have undergone liver transplantation. Six patients that had been transplanted because of hepatitis B liver disease were retrospectively evaluated. Three of them developed non-oncological complications related to liver cirrhosis, two had hepatocellular carcinoma and another one had fulminant HBV hepatitis. The mean follow-up was 22 months (range: 7-52 months). The 6 patients received entecavir as prophylactic treatment before transplantation. The pretransplant viral load was undetectable in all patients. HBsAg seroconversion was observed in four of the six patients. Three patients died during follow-up, two because of recurrent hepatocellular carcinoma, none of them had detectable HBV serum viral load. In a small series of patients we could demonstrate that a regimen with a single dose of gamma globulin entecavir is effective in the post-transplant management of patients with liver disease associated with HBV. Future studies will be able to demonstrate the effectiveness of specific gamma globulin-free regimens.


Subject(s)
Antiviral Agents/administration & dosage , Guanine/analogs & derivatives , Hepatitis B/prevention & control , Immunoglobulins/administration & dosage , Liver Cirrhosis/surgery , Liver Transplantation , Adult , Aged , Argentina , Drug Therapy, Combination , Female , Guanine/administration & dosage , Humans , Liver Cirrhosis/virology , Male , Middle Aged , Retrospective Studies , Secondary Prevention
18.
Science ; 338(6106): 524-8, 2012 Oct 26.
Article in English | MEDLINE | ID: mdl-23112332

ABSTRACT

Human immunodeficiency virus type 1 (HIV-1) buds from the cell as an immature particle requiring subsequent proteolysis of the main structural polyprotein Gag for morphological maturation and infectivity. Visualization of the viral envelope (Env) glycoprotein distribution on the surface of individual HIV-1 particles with stimulated emission depletion (STED) superresolution fluorescence microscopy revealed maturation-induced clustering of Env proteins that depended on the Gag-interacting Env tail. Correlation of Env surface clustering with the viral entry efficiency revealed coupling between the viral interior and exterior: Rearrangements of the inner protein lattice facilitated the alteration of the virus surface in preparation for productive entry. We propose that Gag proteolysis-dependent clustering of the sparse Env trimers on the viral surface may be an essential aspect of HIV-1 maturation.


Subject(s)
HIV-1/physiology , Virus Internalization , env Gene Products, Human Immunodeficiency Virus/metabolism , gag Gene Products, Human Immunodeficiency Virus/metabolism , HIV-1/metabolism , HIV-1/ultrastructure , Humans , Microscopy, Fluorescence , Nanotechnology/methods , Protein Multimerization , Proteolysis
19.
Retrovirology ; 9: 60, 2012 Jul 25.
Article in English | MEDLINE | ID: mdl-22830600

ABSTRACT

BACKGROUND: Entry of human immunodeficiency virus type 1 (HIV-1) into the host cell involves interactions between the viral envelope glycoproteins (Env) and the cellular receptor CD4 as well as a coreceptor molecule (most importantly CCR5 or CXCR4). Viral preference for a specific coreceptor (tropism) is in particular determined by the third variable loop (V3) of the Env glycoprotein gp120. The approval and use of a coreceptor antagonist for antiretroviral therapy make detailed understanding of tropism and its accurate prediction from patient derived virus isolates essential. The aim of the present study is the development of an extended description of the HIV entry phenotype reflecting its co-dependence on several key determinants as the basis for a more accurate prediction of HIV-1 entry phenotype from genotypic data. RESULTS: Here, we established a new protocol of quantitation and computational analysis of the dependence of HIV entry efficiency on receptor and coreceptor cell surface levels as well as viral V3 loop sequence and the presence of two prototypic coreceptor antagonists in varying concentrations. Based on data collected at the single-cell level, we constructed regression models of the HIV-1 entry phenotype integrating the measured determinants. We developed a multivariate phenotype descriptor, termed phenotype vector, which facilitates a more detailed characterization of HIV entry phenotypes than currently used binary tropism classifications. For some of the tested virus variants, the multivariant phenotype vector revealed substantial divergences from existing tropism predictions. We also developed methods for computational prediction of the entry phenotypes based on the V3 sequence and performed an extrapolating calculation of the effectiveness of this computational procedure. CONCLUSIONS: Our study of the HIV cell entry phenotype and the novel multivariate representation developed here contributes to a more detailed understanding of this phenotype and offers potential for future application in the effective administration of entry inhibitors in antiretroviral therapies.


Subject(s)
HIV-1/physiology , Receptors, CCR5/metabolism , Receptors, CXCR4/metabolism , Virus Internalization , Amino Acid Sequence , Benzylamines , CCR5 Receptor Antagonists , Computational Biology , Cyclams , Cyclohexanes/pharmacology , Genetic Vectors , HEK293 Cells , HIV Fusion Inhibitors/pharmacology , HIV Infections/metabolism , HIV Infections/virology , HIV-1/drug effects , Heterocyclic Compounds/pharmacology , Humans , Maraviroc , Models, Biological , Molecular Sequence Data , Multivariate Analysis , Phenotype , Receptors, CXCR4/antagonists & inhibitors , Receptors, CXCR4/genetics , Transfection , Triazoles/pharmacology
20.
Medicina (B.Aires) ; 72(1): 10-14, feb. 2012. graf, tab
Article in Spanish | LILACS | ID: lil-639644

ABSTRACT

El pronóstico de la enfermedad crónica hepática depende de la extensión y la progresión de la fibrosis hepática. Actualmente la biopsia hepática es la técnica de elección para determinar el grado de fibrosis, pero es una prueba invasiva, no exenta de complicaciones. Por ello, el desarrollo de marcadores no invasivos de fibrosis hepática se convirtió en una necesidad indiscutible. Se propuso la elastografìa por transición (Fibroscan®) para valorar la fibrosis hepática en pacientes con enfermedad crónica hepática, mediante la medición de la rigidez hepática. Nuestro objetivo fue evaluar la efectividad, la objetividad y la seguridad de esta técnica. Se estudiaron 68 pacientes a los que se les realizó una biopsia hepática en los 18 meses previos al estudio. Todos los procedimientos de elastografia y biopsia hepática fueron analizados por un mismo profesional (DA y MA, respectivamente). Para la valoración de la biopsia hepática se utilizó la escala METAVIR. El valor medio de rigidez en pacientes sin fibrosis o con fibrosis leve (F0-F1) y en los pacientes con fibrosis avanzada o cirrosis (F3-F4) fue 6.8 ± 3.0 kPa y 21.0 ± 15.1 kPa, respectivamente (con diferencia significativa, p < 0.01). Las áreas debajo de la curva ROC definieron los niveles de corte en cada grupo. Con independencia del diagnóstico etiológico de enfermedad hepática, hallamos una correlación positiva, en todos los pacientes, entre rigidez hepática medida por elastografìa y grado de fibrosis hepática en la biopsia. En conclusión, podemos considerar que el Fibroscan® es un método no invasivo, seguro, fácil y rápido, que lo convierte en la alternativa a la biopsia para identificar fibrosis significativa o cirrosis.


The prognosis and management of chronic liver disease largely depends on the extent and progression of liver fibrosis. Unfortunately, liver biopsy, an invasive and painful technique with several limitations, continues to be the gold standard for the staging and grading of fibrosis. Therefore, accurate noninvasive tests for liver injury are urgently needed. During the last years, transient elastography (Fibroscan®) has been proposed for the assessment of hepatic fibrosis in patients with chronic liver disease, by measuring liver stiffness. The aim of this study was to evaluate the effectiveness, objectivity and safety of this technique. We included 68 patients who underwent a liver biopsy in the last 18 months with a wide spectrum of chronic liver diseases. All procedures as well as the liver biopsies according to the METAVIR scoring system were analyzed by the same sonographer and the same specialist in pathology, respectively. Median value of stiffness with none or mild fibrosis (F0 and FI), and severe fibrosis or cirrhosis (F3 and F4) was 6.8 ± 3.0 kPa and 21.0 ± 15.1 kPa, respectively, with a significant difference between them (p < 0.01). The areas under the receiver operating characteristic curves showed the optimal liver stiffness cut-off values for each group. We found also a positive correlation between liver stiffness found by transient elastography and fibrosis stage on biopsy in all patients, independently of the liver disease etiology. Fibroscan® is an easy, quick to perform and safe non-invasive method, reliable for assessing liver fibrosis.


Subject(s)
Female , Humans , Male , Middle Aged , Elasticity Imaging Techniques/methods , Liver Cirrhosis/pathology , Liver Cirrhosis , Liver/pathology , Biopsy , Biomarkers/analysis , Chronic Disease , Cross-Sectional Studies , Elasticity Imaging Techniques/standards , Fibrosis
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