Papers by Georgios Ayiomamitis
Hellenic Journal of Surgery, 2017
IntroductionPatients with ventriculoperitoneal shunts (VPS) are at risk of associated complicatio... more IntroductionPatients with ventriculoperitoneal shunts (VPS) are at risk of associated complications during laparoscopic surgery. Although these cases are rare, the surgeon should be aware of the pathophysiology of such complications in order to recognize and avoid them.Case presentationThree patients with a VPS who underwent laparoscopic cholecystectomy are presented. Two of the patients suffered from symptomatic gallstone disease, and the third, the oldest, from acute calculus cholecystitis. All patients had a VPS because of hydrocephalus. There were no intraoperative complications in this series.DiscussionThis small case series presents a rare condition that can be the cause of complications during laparoscopic surgery. Septic complications, including VPS infection and cerebrospinal fluid (CSF) infection, pneumocephalus, CSF pseudocyst, and adhesions due to the presence of the VPS, are all possible occurrences. These are discussed, with a short literature review.
Analytical cellular pathology (Amsterdam), 2018
To study the expression of angiodrastic chemokines in colorectal tumors and correlate findings wi... more To study the expression of angiodrastic chemokines in colorectal tumors and correlate findings with clinicopathological parameters and survival. The proangiogenic factor VEGF, the angiogenic chemokines CXCL8 and CXCL6, and the angiostatic chemokine CXCL4 were measured by ELISA in tumor and normal tissue of 35 stage II and III patients and correlated with the histopathology markers Ki67, p53, p21, bcl2, EGFR, and MLH1 and 5-year survival. The Wilcoxon and chi-square tests were used for statistical comparisons. There was a significant increase of CXCL6 ( = 0.005) and VEGF ( = 0.003) in cancerous tissue compared to normal. Patients with lower levels of CXCL8 and CXCL4 lived significantly longer. Patients with loss of EGFR expression had higher levels of CXCL8 while p21 loss was associated with higher levels of CXCL6. Chemokine levels were not correlated with TNM or Dukes classification. Strong expression of p53 was accompanied by decreased survival. (1) The angiogenic factors CXCL6 and...
Hormones (Athens, Greece), 2017
The elucidation of the changes of fetuin-A in the context of bariatric surgery. Twenty obese pati... more The elucidation of the changes of fetuin-A in the context of bariatric surgery. Twenty obese patients (8 males, 12 females; body mass index = 42.5±3.4 kg/m2) were studied at baseline and 6 months after bariatric surgery. Serum fetuin-A levels did not differ with regard to the presence of each individual component of the Metabolic Syndrome (MetS) at baseline, except for hypertriglyceridaemia [increased serum fetuin-A levels (p=0.011)]. Circulating fetuin-A was positively correlated with serum triglycerides (TG) (r=0.461, p=0.047) and negatively correlated with serum globulins (r=-0.477, p=0.033) and C-reactive protein (CRP) (r=-0.604, p=0.010), while it independently predicted TG at baseline. Circulating fetuin-A did not change during the 6 months either in the whole population or in the subgroups of patients who were positive for each individual component of MetS at baseline and negative for this component at 6 months of follow-up, except for hypertriglyceridaemia [reduction of seru...
Hellenic Journal of Surgery, 2012
Case Reports in Oncological Medicine, 2014
Introduction. Primary splenic angiosarcoma is an extremely unusual neoplasm originating from sinu... more Introduction. Primary splenic angiosarcoma is an extremely unusual neoplasm originating from sinusoidal vascular endothelium. Surgical extirpation is the mainstay of treatment of this highly malignant disease.Case Presentation. An 82-year-old woman was admitted with left pleural effusion and a palpable left upper quadrant abdominal mass, secondary to splenomegaly by two large splenic tumors. Classic open splenectomy was performed and angiosarcoma of the spleen was the final histopathological diagnosis, which was primary since no other disease site was revealed.Discussion. The incidence of the disease is 0.14–0.23 cases per million, with slight male predominance. Etiology is not established and clinical presentation may confuse even experienced physicians. Imaging modalities cannot differentiate the lesion from other vascular splenic neoplasms and the correct diagnosis is mainly set after histopathological examination of the resected spleen. As with other sarcomas, surgery is the onl...
Hellenic Journal of Surgery
Differences in clinical presentation, epidemiology, prognosis, and molecular mechanisms between l... more Differences in clinical presentation, epidemiology, prognosis, and molecular mechanisms between left-sided colon cancer (LCC) and right-sided colon cancer (RCC) have been widely studied in recent years. Indeed, mutations seen in LCC differ in nature and frequency compared to LCC. Furthermore, the differences in the biological environment, including histopathological, microbiological, and biochemical differences of the two regions promote different gene expressions in carcinomas. These molecular differences distinguish the nature of colorectal cancer according to the primary site of formation. In this narrative review, all such differences have been explored in detail with the aim of providing further insights into the topic, since in the era of individualised treatment, sidedness is a major factor in the treatment of colorectal cancer.
Figure S9. Overall survival between CRCs with high and low load of tumor-assocated neutrophils (... more Figure S9. Overall survival between CRCs with high and low load of tumor-assocated neutrophils (TAN load), using combined CRC samples from the TCGA-COAD and READ datasets, respectively. The patients were separated into high and low TAN load, based on the median number of TANs. (JPG 19 kb)
Figure S8. CIBERSORT analysis results (in silico flow cytometry) depict the fractional representa... more Figure S8. CIBERSORT analysis results (in silico flow cytometry) depict the fractional representation of 22 hematopoietic cell types present in the gene expression profile of each cytolytic subset in colon (COAD) and rectal (READ) cancers, respectively. Columns represent cell types from the signature genes file and rows represent the deconvolution results for each tumor sample within each cytolytic subgroup. Filtering was set at p = 0.05 with 1000 permutations during analysis. All results are reported as relative fractions normalized to 1 across all cell subsets. P-value: Statistical significance of the deconvolution result across all cell subsets; useful for filtering out results with a poor "goodness of fit". Correlation: Pearson's correlation coefficient (R), generated from comparing the original mixture with the estimated mixture, the latter of which is calculated using imputed cell fractions and corresponding expression profiles from the signature genes file. Of n...
Figure S7. Expression of differentially expressed Treg markers in cytolytic subsets of colorectal... more Figure S7. Expression of differentially expressed Treg markers in cytolytic subsets of colorectal cancer. (JPG 1825 kb)
Figure S6. MATH scores did not correlate with the number of classically defined neoepitopes (CDN)... more Figure S6. MATH scores did not correlate with the number of classically defined neoepitopes (CDN) or alternatively defined neoepitopes (ADN) neoepitopes in CRC. (JPG 474 kb)
Figure S5. Top 25 mutually exclusive ( 1 log10 p-value) gene pairs in COAD and READ, using pair-w... more Figure S5. Top 25 mutually exclusive ( 1 log10 p-value) gene pairs in COAD and READ, using pair-wise Fisher's exact test. The red arrow indicates significant mutual exclusivity between BRAF and APC in COAD. (JPG 530 kb)
Figure S4. APC and KRAS mutation types across the two CRC datasets and association with the cytol... more Figure S4. APC and KRAS mutation types across the two CRC datasets and association with the cytolytic index, showing no statistically significant correlation between APC or KRAS mutations and CYT-high or -low subsets. (JPG 1232 kb)
Figure S3. Gene set variation analysis (GSVA) of known immune-related gene sets (e.g., BIOCARTA_C... more Figure S3. Gene set variation analysis (GSVA) of known immune-related gene sets (e.g., BIOCARTA_CTL_PATHWAY; TCYTOTOXIC_PATHWAY; TCRA_PATHWAY; THELPER_PATHWAY; PD1_SIGNALING; PRODUCING_DENDRITIC_CELL) showed statistically significant increase in CRCs identified as CYT-high, based on the expression of GZMA and PRF1. (JPG 1293 kb)
Figure S2. Enrichment of selected immune-related gene sets in CYT-high colon (COAD) and rectum (R... more Figure S2. Enrichment of selected immune-related gene sets in CYT-high colon (COAD) and rectum (READ) adenocarcinomas. A. Cytolytic-high tumors show increased enrichment of gene sets from activated, cytolytic CD8+ T-cell populations and PD1high CD8 T-cells [38, 39]. B. Gene set variation analysis (GSVA) of known immune-related gene sets shows statistically significant increase in CYT-high colon and rectal tumors. (JPG 2337 kb)
Table S10. CIBERSORT analysis results depict the fractional representations of 22 hematopoietic c... more Table S10. CIBERSORT analysis results depict the fractional representations of 22 hematopoietic cell types present in the gene expression profile of each cytolytic subset in colon (COAD) and rectal (READ) cancers, respectively. Columns represent cell types from the signature genes file and rows represent deconvolution results for each tumor sample in each cytolytic subgroup. Filtering was set at p = 0.05 with 1000 permutations during analysis. All results are reported as relative fractions normalized to 1 across all cell subsets. P-value: Statistical significance of the deconvolution result across all cell subsets; useful for filtering out results with a poor "goodness of fit". Correlation: Pearson's correlation coefficient (R), generated from comparing the original mixture with the estimated mixture, the latter of which is calculated using imputed cell fractions and corresponding expression profiles from the signature genes file. Of note, the correlation is restricted...
Table S9. Tumor heterogeneity was inferred using â maftoolsâ , with which we clustered variant al... more Table S9. Tumor heterogeneity was inferred using â maftoolsâ , with which we clustered variant allele frequencies (VAF). We also measured the extent of heterogeneity in terms of a numerical value. Mutant-Allele Tumor Heterogeneity (MATH) score is a simple quantitative measure of intra-tumor heterogeneity, which calculates the width of the VAF distribution. (XLSX 86 kb)
Table S8. GISTIC (v2.0.22) analysis results for rectal cancers (READ). GISTIC was used to detect ... more Table S8. GISTIC (v2.0.22) analysis results for rectal cancers (READ). GISTIC was used to detect recurrent somatic copy number alterations (SCNA) in CYT-high and -low rectum cancers, using MutSigCV (v1) from the Broad Institute's GenePattern. Each SCNA was assigned a G-score indicative of its amplitude and occurrence across samples. SCNAs in each RED sample within each cytolytic subgroup were counted by taking the sum of segment mean changes ≥ 0.6 and ≤ − 0.4 between somatic and normal samples. Significantly amplified or deleted genomic regions in each cytolytic subgroup with FDR
Table S7. GISTIC (v2.0.22) analysis results for colon cancers (COAD). GISTIC was used to detect r... more Table S7. GISTIC (v2.0.22) analysis results for colon cancers (COAD). GISTIC was used to detect recurrent somatic copy number alterations (SCNA) in CYT-high and -low colon cancers, using MutSigCV (v1) from the Broad Institute's GenePattern. Each SCNA was assigned a G-score indicative of its amplitude and occurrence across samples. SCNAs in each COAD sample within each cytolytic subgroup were counted by taking the sum of segment mean changes ≥ 0.6 and ≤ − 0.4 between somatic and normal samples. Significantly amplified or deleted genomic regions in each cytolytic subgroup with FDR
Table S6. Top-upregulated genes in the cytolytic-high (CYT-high) COAD and READ tumors, against th... more Table S6. Top-upregulated genes in the cytolytic-high (CYT-high) COAD and READ tumors, against their cytolytic-low (CYT-low) counterparts. (XLSX 9165 kb)
Table S5. Patient IDs and cytolytic activity levels (CYT) for CYT-high and CYT-low cytolytic subg... more Table S5. Patient IDs and cytolytic activity levels (CYT) for CYT-high and CYT-low cytolytic subgroups of COAD and READ tumors. (XLSX 27546 kb)
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Papers by Georgios Ayiomamitis