publications

Preprints

1. Structural and functional neuroimaging of late-life depression: a coordinate-based meta-analysis Saberi A, Mohammadi E, Zarei M, Eickhoff S, and Tahmasian M* PsyArXiv, 2020 [abstract] [my experience] [doi] [pdf]

   Several neuroimaging studies have investigated localized aberrations in brain structure, function or connectivity in late-life depression, but the ensuing results are equivocal and often conflicting. Here, we provide a quantitative consolidation of neuroimaging in late-life depression using coordinate-based meta-analysis by searching multiple databases and tracing the relevant references up to March 2020. Our search revealed 3252 unique records, among which we identified 32 eligible whole-brain neuroimaging publications comparing 674 late-life depression patients with 568 healthy controls. The peak coordinates of group comparisons between patients and controls were extracted and then analyzed using activation likelihood estimation method. Our sufficiently powered analysis on all the experiments, and more homogenous subsections of the data (in-/decreases, experiments using functional imaging) revealed no significant convergent regional abnormality in late-life depression. This inconsistency might be due to experimental (e.g., choice of tasks, image modalities) and analytic flexibility (e.g., preprocessing and analytic parameters), distributed patterns of neural abnormalities, and heterogeneity of clinical populations (e.g., severity of late-life depression, age of onset). Our findings highlight the need for more reproducible research by using pre-registered and standardized protocols on more homogenous populations to identify potential consistent brain abnormalities in late-life depression.

   Learned how to do coordinate-based meta-analyses. Also learned a lot about the different methods of neuroimaging by reading the neuroimaging studies on late-life depression.

Papers

1. Predictive value of red blood cell distribution width for mortality in patients with acute pancreatitis: A systematic review and meta-analysis Ganji A, Esmaeilzadeh A, Ghanaei O, Saberi A*, Taherzadeh D, Sazgarnia S, Mayabi Joghal Z, Zirak M, AbdolahRamazani S, and Zarifmahmoudi L Medical Journal of the Islamic Republic of Iran Q3, 2017 [abstract] [my experience] [doi] [pdf]

   Background: Red blood cell distribution width (RDW) is a quantitative measure of variability in the size of circulating erythrocytes. It has been recently identified as a prognostic marker in several diseases including acute pancreatitis (AP). In this systematic review the prognostic value of RDW in predicting mortality of AP patients will be assessed.
   Methods: PubMed, Scopus, EMBASE, and ISI databases were searched until September 2016 using the following search strategy: (pancreatitis OR pancreatitides) AND (RDW OR "red cell distribution width" OR "red blood cell distribution width" OR anisocytosis). Four authors independently reviewed the retrieved articles. Studies were included if they had evaluated the association between RDW value and mortality of acute pancreatitis patients. Case reports, comments, letters to the editor, reviews, study protocols, and experimental studies were not included. Data abstraction and quality assessment for the included studies was independently performed by two authors. Quality of studies was assessed using Oxford Center for Evidence-Based Medicine checklist for prognostic studies. Data were synthesized qualitatively, and a meta-analysis was performed on the diagnostic performance of RDW to predict mortality in AP patients.
   Results: Seven studies (976 patients) were included in the systematic review. Six studies reported a statistically significant association between RDW value and mortality. Meta-analysis was performed on four studies (487 patients) using a bivariate model and a summary receiver operating characteristic (sROC) curve was plotted with an area under the curve (AUC) of 0.757. The pooled diagnostic odds ratio (DOR), sensitivity and specificity was 19.51 (95% CI: 5.26-72.30), 67% (95% CI: 51%-80%) and 90% (95% CI: 73%-96%), respectively.
   Conclusion: RDW is an easy to use and an inexpensive marker with a moderate prognostic value to predict death in AP patients. Clinicians should be more alert when a patient with AP has an increased RDW. Investigation of possible combinations of other prognostic markers with RDW is recommended.

   Learned how to design and manage a systematic review and meta-analysis in practice, and drafted my very first manuscript, as the corresponding author.

Conference Abstracts

1. A Coordinate Based Meta-Analysis on the Brain Functional and Structural Changes in Late Life Depression Saberi A, Mohammadi E, Eickhoff C, Zarei M, Eickhoff S, and Tahmasian M* 6th Iranian Human Brain Mapping Congress, Shahid Beheshti University (Tehran, Iran), 2019 [abstract] Oral Best Presentation Award

   Late life depression (LLD) is turning into a health concern with the aging of the population. Its unique presentation with somatic symptoms and cognitive dysfunction highlights the need to study LLD as a distinct disease process from depression in younger adults. Numerous functional and structural neuroimaging studies have investigated the neural correlates of LLD, but have reported inconsistent results. In this study, we aimed to identify locations in the brain that were most consistently altered across the existing studies.Method We searched PubMed, Embase, and Web of Knowledge for relevant studies published until July 2019 and retrieved 2657 potential studies. All whole-brain voxel-based morphometry (VBM), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI) studies comparing patients with LLD and healthy controls (HC) were included. Two authors independently extracted the data and the peak coordinates of the significant foci. Coordinate-based meta-analysis was performed using the revised activation likelihood estimation (ALE) method according to the current best-practice guidelines.Results We identified 23 eligible studies (eight VBM, one PET, five resting-state fMRI, and ten task-based fMRI) including 516 LLD patients and 490 HCs. No significant converging structural and functional brain abnormalities between LLD and HC (27 experiments) was observed after controlling for multiple comparisons using a stringent cluster-level family-wise error correction (pcFWE = 0.680). Additionally, the meta-analysis on LLD > HC with 13 experiments (pcFWE = 0.069) and LLD < HC with 14 experiments (pcFWE = 0.357) revealed no significant convergent abnormalities.Conclusions The lack of convergence across individual studies might be related to the differences in experimental designs and statistical approaches, heterogeneity of clinical populations, and small sample sizes of the individual studies. Currently, there is not enough evidence available to pinpoint a specific underlying neural pathology associated with LLD.

2. Neutrophil to Lymphocyte Ratio as a Prognostic Marker in Glioblastoma Multiforme: a Systematic Review and Meta-Analysis Saberi A*, and Ghodsi H 1st International Neuroinflammation Congress, Ghaem Hospital (Mashhad, Iran), 2017 [abstract] [doi] [poster]

   Introduction: Glioblastoma multiforem (GBM) is the most common primary malignant brain tumor in adults and it is important to identify biomarkers that can predict its prognosis. The aim of this study was to systematically review the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in patients with GBM.
   Materials and Methods: PubMed, Scopus and EMBASE databases were searched until February 2016 using the following search strategy: neutrophil* AND lymphocyte* AND (glioma OR glioblastoma OR astrocytoma). Two authors independently screened the retrieved articles to find all the studies that evaluated the prognostic value of NLR in GBM patients. Data extraction and quality assessment for the included studies was performed independently by two authors. Studies using Cox proportional hazards model to compare overall survival (OS) in patients with low and high values of NLR were included in the meta-analysis.
   Results: Six studies and 827 patients were included in the systematic review. Progression-free survival (PFS) was the primary outcome in two studies. One study identified lower values of NLR as a significant predictor of better PFS, but the other one showed the opposite effect. Performing a meta-analysis was not possible on these two studies. The primary outcome in six studies was OS, four of which reported NLR as a significant prognostic marker. Pooled univariate hazard ratios (HRs) of two studies for predicting OS was 1.903 (95% CI: 1.420-2.551) and pooled multivariate HRs of four studies for predicting OS was 1.564 (95% CI: 1.208-2.024). Negligible heterogeneity was observed between studies.
   Conclusion: Overall survival of GBM patients can be predicted using NLR, but its application as a predictive marker of PFS is uncertain.

3. Cerebral blood volume as a prognostic marker in glioblastoma patients treated with bevacizumab: a systematic review Saberi A*, Gazanchian M, Ghodsi H, Mofatteh A, and Nazarpour S 1st International Razavi Cancer Congress, Razavi Hospital (Mashhad, Iran), 2016 [abstract] [doi] [poster]

   Context: Bevacizumab is an FDA approved antiangiogenic agent for the treatment of recurrent glioblastoma. Patients have varied response to this treatment and it is important to identify biomarkers that can predict responders.
   Objective: To systematically review the prognostic value of cerebral blood volume (CBV) in glioblastoma patients treated with bevacizumab.
   Data sources: PubMed, Scopus and EMBASE databases were searched until March 2016 using the following search strategy: “glioblastoma AND bevacizumab AND (‘cerebral blood volume’ OR ‘relative blood volume’ OR CBV OR rCBV or RBV)”.
   Study Selection: Two authors independently reviewed the retrieved articles. All studies that evaluated the prognostic value of cerebral blood volume in glioblastoma patients treated with bevacizumab were included. Case reports, letters to editor and review articles were excluded.
   Data Extraction: Data extraction for included studies was performed independently by two authors. Quality of studies was assessed using Oxford Center for Evidence-Based Medicine checklist for prognostic studies.
   Results: Eight studies (303 patients) were included. In six studies all the patients had recurrent glioblastoma and in one study patients with grade III glioma were included as well. OS and PFS were the outcomes of interest in 7 and 8 studies, respectively. To evaluate the prognostic value of cerebral blood volume, six studies performed log-rank survival analysis and five studies used univariate or multivariate Cox proportional hazards model, three of which reported hazard ratios. Cerebral blood volume was reported as a significant predictor of OS and PFS in 4 studies (173 patients).
   Conclusions: The conflicting results of included studies indicate that the application of cerebral blood volume as a prognostic factor in glioblastoma patients treated with bevacizumab is uncertain. We suggest performing a meta-analysis to further explore this prognostic role.

4. The effect of stress on working memory in individuals with different personality traits Acheshmeh Z, Alizade H, Ghodsi H, Saberi A, and Shahrokhi Y 1st Razavi International Anxiety Congress, Razavi Hospital (Mashhad, Iran), 2012 [abstract]

   Stress affects working memory based on plenty of evidences and in most cases its effect is impairing. It seems that severity of this effect depends on multiple factors. One of the possible factors may be personality traits. Current study is designed to examine probable vulnerability of some personality traits to the effect of social stress on working memory. In this study, performance of individuals in working memory test will be compared before and after the treatment with Trier Social Stress Test (TSST). Individuals’ personality will be evaluated based on NEO-FFI (NEO-Five Factor Inventory). Salivary Cortisol levels will be measured before and after the treatment as a marker of HPAA (Hypothalamic-Pituatury-Adrenal axis) activity. Finally, we will analyze the correlation between data obtained from working memory test and NEO-FFI.

* corresponding author