Mario Calvo Arellano

Dr. Mario Calvo Arellano

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2006 in Journal of Clinical Gastroenterology
Verified
Journal Article
Closed access
ARArnoldo Riquelme
Arnoldo Riquelme
MCMario Calvo
Mario Calvo
FSFelipe Salech
Felipe Salech
SVSebastián Valderrama
Sebastián Valderrama
APAlejandro Pattillo
Alejandro Pattillo
LLLuz María Letelier
Luz María Letelier
Adenosine deaminase (ADA) levels are used for diagnosing tuberculosis in several locations and although many studies have evaluated ADA levels in ascitic fluid. These studies have defined arbitrary cut-off points creating difficulties in the clinical application of the results. The goals of this study are: to determine the usefulness of ADA levels in ascitic fluid as a diagnostic test for peritoneal tuberculosis (PTB) and define the best cut-off point. A systematic review was done on the basis of 2 independent searches. We selected prospective studies that included consecutive patients. Diagnosis of PTB had to be confirmed by bacteriologic or histologic methods and ADA levels determined by the Giusti method. Inclusion/exclusion criteria were applied by 2 independent reviewers. A receiver operating characteristic curve was constructed to establish the optimal cut-off point and the likelihood ratios (LRs) estimated using fixed-effect pooled method. Twelve prospective studies were found. Four of them met the inclusion criteria and were thus included in the meta-analysis. They included 264 patients, of which 50 (18.9%) had PTB. ADA levels showed high sensitivity (100%) and specificity (97%) using cut-off values from 36 to 40 IU/L. The included studies were homogeneous. Optimal cut-off point was determined at 39 IU/L, and LRs were 26.8 and 0.038 for values above and below this cut-off. This study supports the proposition that ADA determination is a fast and discriminating test for diagnosing PTB with an optimal cut-off value of 39 IU/L.

1 October 2014 in Emerging Infectious Diseases
Verified
Journal Article
Open access
CMConstanza Martinez-Valdebenito
Constanza Martinez-Valdebenito
MAMario Calvo Arellano
Mario Calvo Arellano
CVCecilia Vial
Cecilia Vial
RMRita Mansilla
Rita Mansilla
CMClaudia Marco
Claudia Marco
MFMarcela Ferres
Marcela Ferres
Andes hantavirus (ANDV) causes hantavirus cardiopulmonary syndrome in Chile and is the only hantavirus for which person-to-person transmission has been proven. We describe an outbreak of 5 human cases of ANDV infection in which symptoms developed in 2 household contacts and 2 health care workers after exposure to the index case-patient. Results of an epidemiologic investigation and sequence analysis of the virus isolates support person-to-person transmission of ANDV for the 4 secondary case-patients, including nosocomial transmission for the 2 health care workers. Health care personnel who have direct contact with ANDV case-patients or their body fluids should take precautions to prevent transmission of the virus. In addition, because the incubation period of ANDV after environmental exposure is longer than that for person-to-person exposure, all persons exposed to a confirmed ANDV case-patient or with possible environmental exposure to the virus should be monitored for 42 days for clinical symptoms.

1 January 2003 in Journal of Clinical Gastroenterology
Verified
Journal Article
Closed access
ARArnoldo J. Riquelme
Arnoldo J. Riquelme
MAMario Calvo Arellano
Mario Calvo Arellano
AGAna M. Guzmán
Ana M. Guzmán
MDMaría S. Depix
María S. Depix
PGPatricia García
Patricia García
JLJaime A. Labarca
Jaime A. Labarca
Saccharomyces boulardii is widely used as a probiotic compound. Clinical data suggest that this agent is safe and effective. We report two cases of fungemia caused by S. cerevisiae occurring in immunosuppressed patients treated orally with S. boulardii. Molecular typing confirmed clonality in isolate strains from patients and the S. boulardii capsule. Physicians caring for immunosuppressed patients must be aware of this potential serious complication of probiotic use.

1 May 2014 in Antiviral Therapy
Verified
Journal Article
Closed access
PVPablo A Vial
Pablo A Vial
FVFrancisca Valdivieso
Francisca Valdivieso
MAMario Calvo Arellano
Mario Calvo Arellano
MRM Luisa Rioseco
M Luisa Rioseco
RRRaul Riquelme
Raul Riquelme
HCHantavirus Study Group in Chile
Hantavirus Study Group in Chile
Background: In Chile, Andes virus (ANDV) is the sole aetiological agent of hantavirus cardiopulmonary syndrome (HCPS) with mean annual incidence of 55 cases, 32% case fatality rate (CFR) and no specific treatment. Neutralizing antibody (NAb) titres at hospital admission correlate inversely with HCPS severity. We designed an open trial to explore safety and efficacy and evaluate pharmacokinetics of immune plasma as a treatment strategy for this disease. Methods: We performed plasmapheresis on donors at least 6 months after HCPS and measured NAb titres through a focus-reduction neutralization test. Subjects admitted to 10 study sites with suspected/confirmed HCPS were eligible for treatment with immune plasma by intravenous infusion at an ANDV NAb dose of 5,000 U/kg. HCPS was confirmed through immunoglobulin M serology or reverse transcriptase-PCR. The main outcome was mortality within 30 days. Results: From 2008–2012, we enrolled and treated 32 cases and confirmed HCPS in 29. CFR of hantavirus plasma-treated cases was 4/29 (14%); CFR of non-treated cases in the same period in Chile was 63/199 (32%; P=0.049, OR=0.35, CI=0.12, 0.99); CFR of non-treated cases at the same study sites between 2005–2012 was 18/66 (27%; ( P=0.15, OR=0.43, CI=0.14, 1.34) and CFR in a previous methylprednisolone treatment study was 20/60 (33%; P=0.052, OR=0.32, CI=0.10, 1.00). We detected no serious adverse events associated to plasma infusion. Plasma NAb titres reached in recipients were variable and viral load remained stable. Conclusions: Human ANDV immune plasma infusion appears safe for HCPS. We observed a decrease in CFR in treated cases with borderline significance that will require further studies for confirmation.

19 June 2013 in Clinical Infectious Diseases
Verified
Journal Article
Open access
PDF file
PVPablo A Vial
Pablo A Vial
FVFrancisca Valdivieso
Francisca Valdivieso
MFMarcela Ferres
Marcela Ferres
RRRaul Riquelme
Raul Riquelme
MRM. Luisa Rioseco
M. Luisa Rioseco
EBEdward Bedrick
Edward Bedrick
Background. Andes virus (ANDV)–related hantavirus cardiopulmonary syndrome (HCPS) has a 35% case fatality rate in Chile and no specific treatment. In an immunomodulatory approach, we evaluated the efficacy of intravenous methylprednisolone for HCPS treatment, through a parallel-group, placebo-controlled clinical trial. Methods. Patients aged >2 years, with confirmed or suspected HCPS in cardiopulmonary stage, admitted to any of 13 study sites in Chile, were randomized by study center in blocks of 4 with a 1:1 allocation and assigned through sequentially numbered envelopes to receive placebo or methylprednisolone 16 mg/kg/day (≤1000 mg) for 3 days. All personnel remained blinded except the local pharmacist. Infection was confirmed by immunoglobulin M antibodies or ANDV RNA in blood. The composite primary endpoint was death, partial pressure of arterial oxygen/fraction of inspired oxygen ratio ≤55, cardiac index ≤2.2, or ventricular tachycardia or fibrillation within 28 days. Safety endpoints included the number of serious adverse events (SAEs) and quantification of viral RNA in blood. Analysis was by intention to treat. Results. Infection was confirmed in 60 of 66 (91%) enrollees. Fifteen of 30 placebo-treated patients and 11 of 30 methylprednisolone-treated patients progressed to the primary endpoint (P = .43). We observed no significant difference in mortality between treatment groups (P = .41). There was a trend toward more severe disease in placebo recipients at entry. More subjects in the placebo group experienced SAEs (P = .02). There were no SAEs clearly related to methylprednisolone administration, and methylprednisolone did not increase viral load. Conclusions. Although methylprednisolone appears to be safe, it did not provide significant clinical benefit to patients. Our results do not support the use of methylprednisolone for HCPS. Clinical Trials Registration. NCT00128180.

21 November 2018 in Science Translational Medicine
Verified
Journal Article
Closed access
PDF file
JGJose L. Garrido
Jose L. Garrido
JPJoseph Prescott
Joseph Prescott
MAMario Calvo Arellano
Mario Calvo Arellano
FBFelipe Bravo
Felipe Bravo
RARaymond Alvarez
Raymond Alvarez
MBMaria Ines Barria
Maria Ines Barria
Post-exposure highly potent human monoclonal antibodies target Andes hantavirus glycoprotein in a hamster hantavirus cardiopulmonary syndrome model.