Alejandra Vargas

Alejandra Vargas


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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28 February 2024 in Clinical Gastroenterology and Hepatology
Verified
Journal Article
Closed access
AVAna Vilela
Ana Vilela
EQElit Quingalahua
Elit Quingalahua
AVAlejandra Vargas
Alejandra Vargas
FHFadi Hawa
Fadi Hawa
CSCarol Shannon
Carol Shannon
JMJorge D Machicado
Jorge D Machicado

3 September 2024 in American Journal of Gastroenterology
Verified
Journal Article
Closed access
ABAzizullah Beran
Azizullah Beran
TATarek Aboursheid
Tarek Aboursheid
AAAdel Hajj Ali
Adel Hajj Ali
HAHashem N Albunni
Hashem N Albunni
MMMouhand Mohamed
Mouhand Mohamed
JGJohn Guardiola
John Guardiola
INTRODUCTION: Inadequate bowel preparation (IBP) before colonoscopy remains a common problem. This meta-analysis aimed to assess the risk factors associated with IBP. METHODS: We searched multiple databases for studies that assessed risk factors for IBP after adjustment and reported the data as adjusted odds ratios with 95% confidence intervals. Meta-analyses were conducted using a random-effects model, and pooled adjusted odds ratios for risk factors reported in ≥ 3 studies were constructed. RESULTS: One hundred fifty-four studies with 358,257 participants were included. We analyzed 48 unique risk factors. Sociodemographic predictors of IBP were Medicaid insurance, obesity, current tobacco use, age ≥ 65 years, Black race, low education level, male sex, and unmarried status. Comorbidity-related predictors of IBP were any psychiatric disease, cirrhosis, American Society of Anesthesiologists (ASA) class ≥ 3, poor functional status, constipation, diabetes, previous abdominopelvic surgery, and hematochezia. Medication-related predictors of IBP were tricyclic antidepressants, antidepressants, opioids, nontricyclic antidepressants, and calcium channel blockers. Preparation/procedure-related predictors of IBP were brown liquid rectal effluent, any incomplete bowel preparation (BP) intake, lack of split-dose BP, increased BP-to-defecation interval, any nonadherence to dietary instructions, increased BP-to-colonoscopy interval, any BP intolerance, previous IBP, and inpatient status. Although afternoon colonoscopy was a predictor of IBP, subgroup analysis of prospective studies revealed no significant association. DISCUSSION: Our meta-analysis focused on adjusted risk factors to provide precise estimates of the most important risk factors for IBP. Our findings could help develop a validated prediction model to identify high-risk patients for IBP, improve colonoscopy outcomes, reduce the need for repeat colonoscopies, and reduce associated healthcare costs.

19 January 2025 in Exploration of Medicine
Verified
Journal Article
Open access
PDF file
AVAlejandra Vargas
Alejandra Vargas
BRBenjamin L. Robinson
Benjamin L. Robinson
KHKevin Houston
Kevin Houston
ASAna Rosa Vilela Sangay
Ana Rosa Vilela Sangay
MSMichael Saadeh
Michael Saadeh
DJDavid Johnson
David Johnson
The gut microbiota, a complex ecosystem of microorganisms, plays an essential role in maintaining immune and metabolic homeostasis. Disruption of this microbial balance, known as dysbiosis, has been increasingly implicated in the pathogenesis of chronic inflammatory conditions, including cardiovascular, gastrointestinal, and autoimmune diseases, as well as metabolic disorders such as diabetes and obesity. A crucial mechanism through which the gut microbiota exerts its effects on host physiology is via the production of bioactive metabolites. These metabolites, including short-chain fatty acids, bile acids, and tryptophan derivatives, are key in modulating immune responses and regulating metabolic functions. Dysbiosis disrupts the production and function of these metabolites, thereby contributing to immune dysregulation, chronic inflammation, and disease progression. This review examines the role of gut microbiota-derived metabolites in chronic inflammatory diseases, with a focus on their immunomodulatory and metabolic effects. A deeper understanding of these mechanisms may open the way for novel therapeutic strategies aimed at restoring immune homeostasis and mitigating the global burden of chronic inflammatory diseases.

6 March 2024 in Diagnostics
Verified
Journal Article
Open access
PDF file
AVAlejandra Vargas
Alejandra Vargas
PDPriyata Dutta
Priyata Dutta
ECEileen Carpenter
Eileen Carpenter
JMJorge D Machicado
Jorge D Machicado
Pancreatic cancer is on the rise and expected to become the second leading cause of cancer-related death by 2030. Up to a one-fifth of pancreatic cancers may arise from mucinous pancreatic cysts, which are frequently present in the general population. Currently, surgical resection is the only curative approach for pancreatic cancer and its cystic precursors. However, only a dismal proportion of patients are eligible for surgery. Therefore, novel treatment approaches to treat pancreatic cancer and precancerous pancreatic cysts are needed. Endoscopic ultrasound (EUS)-guided ablation is an emerging minimally invasive method to treat pancreatic cancer and premalignant pancreatic cysts. Different ablative modalities have been used including alcohol, chemotherapy agents, and radiofrequency ablation. Cumulative data over the past two decades have shown that endoscopic ablation of mucinous pancreatic cysts can lead to cyst resolution in a significant proportion of the treated cysts. Furthermore, novel data are emerging about the ability to endoscopically ablate early and locally advanced pancreatic cancer. In this review, we aim to summarize the available data on the efficacy and safety of the different EUS-ablation modalities for the management of premalignant pancreatic cysts and pancreatic cancer.

25 June 2024 in American Journal of Gastroenterology
Verified
Journal Article
Closed access
ABAzizullah Beran
Azizullah Beran
MMMouhand F.H. Mohamed
Mouhand F.H. Mohamed
AVAlejandra Vargas
Alejandra Vargas
TATarek Aboursheid
Tarek Aboursheid
MAMuhammad Aziz
Muhammad Aziz
MGMarwan S. Ghabril
Marwan S. Ghabril
INTRODUCTION: Diagnostic paracentesis is recommended for patients with cirrhosis admitted to the hospital, but adherence is suboptimal with unclear impact on clinical outcomes. The aim of this meta-analysis was to assess the outcomes of early vs delayed diagnostic paracentesis among hospitalized patients with cirrhosis and ascites. METHODS: We searched multiple databases for studies comparing early vs delayed diagnostic paracentesis among hospitalized patients with cirrhosis and ascites. The pooled odds ratio (OR) and mean difference with confidence intervals (CIs) for proportional and continuous variables were calculated using the random-effects model. Early diagnostic paracentesis was defined as receiving diagnostic paracentesis within 12–24 hours of admission. The primary outcome was in-hospital mortality. Secondary outcomes were length of hospital stay, acute kidney injury, and 30-day readmission. RESULTS: Seven studies (n = 78,744) (n = 45,533 early vs n = 33,211 delayed diagnostic paracentesis) were included. Early diagnostic paracentesis was associated with lower in-hospital mortality (OR 0.61, 95% CI 0.46–0.82, P = 0.001), length of hospital stay (mean difference −4.85 days; 95% CI −6.45 to −3.20; P < 0.001), and acute kidney injury (OR 0.62, 95% CI 0.42–0.92, P = 0.02) compared with delayed diagnostic paracentesis, with similar 30-day readmission (OR 1.11, 95% CI 0.52–2.39, P = 0.79). Subgroup analysis revealed consistent results for in-hospital mortality whether early diagnostic paracentesis performed within 12 hours (OR 0.51, 95% CI 0.32–0.79, P = 0.003, I 2 = 0%) or within 24 hours of admission (OR 0.67, 95% CI 0.45–0.98, P = 0.04, I 2 = 82%). Notably, the mortality OR was numerically lower when diagnostic paracentesis was performed within 12 hours, and the results were precise and homogenous (I 2 = 0%). DISCUSSION: Findings from this meta-analysis suggest that early diagnostic paracentesis is associated with better patient outcomes. Early diagnostic paracentesis within 12 hours of admission may be associated with the greatest mortality benefit. Data from large-scale randomized trials are needed to validate our findings, especially if there is a greater mortality benefit for early diagnostic paracentesis within 12 hours.

17 November 2023 in Pancreatology
Verified
Journal Article
Closed access
IOItegbemie Obaitan
Itegbemie Obaitan
HWHisham Wehbe
Hisham Wehbe
JEJeffrey J. Easler
Jeffrey J. Easler
JSJoseph T. Stethen
Joseph T. Stethen
NMNeetu Mahendraker
Neetu Mahendraker
MAMohammad Al-Haddad
Mohammad Al-Haddad