Helicobacter pylori infection(Hp-I)represents a typical microbial agent intervening in the complex mechanisms of gastric homeostasis by disturbing the balance between the host gastric microbiota and mucosa-related fac...Helicobacter pylori infection(Hp-I)represents a typical microbial agent intervening in the complex mechanisms of gastric homeostasis by disturbing the balance between the host gastric microbiota and mucosa-related factors,leading to inflammatory changes,dysbiosis and eventually gastric cancer.The normal gastric microbiota shows diversity,with Proteobacteria[Helicobacter pylori(H.pylori)belongs to this family],Firmicutes,Actinobacteria,Bacteroides and Fusobacteria being the most abundant phyla.Most studies indicate that H.pylori has inhibitory effects on the colonization of other bacteria,harboring a lower diversity of them in the stomach.When comparing the healthy with the diseased stomach,there is a change in the composition of the gastric microbiome with increasing abundance of H.pylori(where present)in the gastritis stage,while as the gastric carcinogenesis cascade progresses to gastric cancer,the oral and intestinal-type pathogenic microbial strains predominate.Hp-I creates a premalignant environment of atrophy and intestinal metaplasia and the subsequent alteration in gastric microbiota seems to play a crucial role in gastric tumorigenesis itself.Successful H.pylori eradication is suggested to restore gastric microbiota,at least in primary stages.It is more than clear that Hp-I,gastric microbiota and gastric cancer constitute a challenging tangle and the strong interaction between them makes it difficult to unroll.Future studies are considered of crucial importance to test the complex interaction on the modulation of the gastric microbiota by H.pylori as well as on the relationships between the gastric microbiota and gastric carcinogenesis.展开更多
The pandemic of coronavirus disease 2019(COVID-19),caused by a newly identifiedβ-coronavirus(SARS-CoV-2)has emerged as a dire health problem,causing a massive crisis for global health.Primary method of transmission w...The pandemic of coronavirus disease 2019(COVID-19),caused by a newly identifiedβ-coronavirus(SARS-CoV-2)has emerged as a dire health problem,causing a massive crisis for global health.Primary method of transmission was firstly thought to be animal to human transmission.However,it has been observed that the virus is transmitted from human to human via respiratory droplets.Interestingly,SARS-CoV-2 ribonucleic acid(RNA)has been isolated from patient stools,suggesting a possible gastrointestinal(GI)involvement.Most commonly reported clinical manifestations are fever,fatigue and dry cough.Interestingly,a small percentage of patients experience GI symptoms with the most common being anorexia,diarrhea,nausea and vomiting.The presence of viral RNA in stools is also common and fecal tests can be positive even after negative respiratory samples.The exact incidence of digestive symptoms is a matter of debate.The distribution of Angiotensin converting enzyme type 2 receptors in multiple organs in the body provides a possible explanation for the digestive symptoms’mechanism.Cases with solely GI symptoms have been reported in both adults and children.Viral RNA has also been detected in stool and blood samples,indicating the possibility of liver damage,which has been reported in COVID-19 patients.The presence of chronic liver disease appears to be a risk factor for severe complications and a poorer prognosis,however data from these cases is lacking.The aim of this review is firstly,to briefly update what is known about the origin and the transmission of SARS-CoV-2,but mainly to focus on the manifestations of the GI tract and their pathophysiological background,so that physicians on the one hand,not to underestimate or disregard digestive symptoms due to the small number of patients exhibiting exclusively this symptomatology and on the other,to have SARS-CoV-2 on their mind when the“gastroenteritis”type symptoms predominate.展开更多
Pancreatic cancer is one of the highest and in fact,unchanged mortality-associated tumor,with an exceptionally low survival rate due to its challenging diagnostic approach.So far,its treatment is based on a combinatio...Pancreatic cancer is one of the highest and in fact,unchanged mortality-associated tumor,with an exceptionally low survival rate due to its challenging diagnostic approach.So far,its treatment is based on a combination of approaches(such as surgical resection with or rarely without chemotherapeutic agents),but with finite limits.Thus,looking for additional space to improve pancreatic tumorigenesis therapeutic approach,research has focused on gene therapy with unexpectedly growing horizons not only for the treatment of inoperable pancreatic disease,but also for its early stages.In vivo gene delivery viral vectors,despite few disadvantages(possible immunogenicity,toxicity,mutagenicity,or high cost),could be one of the most efficient cancer gene therapeutic strategies for clinical application due to their superiority compared with other systems(ex vivo delivery strategies).Their dominance consists of simple preparation,easy operation and a wide range of functions.Adenoviruses are one of the most common used vectors,inducing strong immune as well as inflammatory reactions.Oncolytic virotherapy,using the above mentioned in vivo viral vectors,is one of the most promising nonpathogenic,highly-selective cytotoxic anti-cancer therapy using anti-cancer agents with high anti-tumor potency and strong oncolytic effect.There have been a variety of targeted therapeutic and pre-clinical strategies tested for gene therapy in pancreatic cancer such as gene-editing systems(e.g.,clustered regularly interspaced palindromic repeats-Cas9),RNA interference technology(e.g.,microRNAs,short hairpin RNA or small interfering RNA),adoptive immunotherapy and vaccination(e.g.,chimeric antigen receptor T-cell therapy)with encouraging results.展开更多
The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was con...The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was considered a zoonotic disease, the virus has also spread among humans via respiratory secretions. The expression and distribution of angiotensin converting enzyme type 2(ACE2) in various human organs might also show other possible infection routes. High ACE2 ribonucleic acid expression has been identified in the gastrointestinal tract(GI) indicating its importance as a possible infection pathway of SARS-CoV-2. ACE2 induces viral entry into the host and most importantly has been found to be associated with the function of the gut. Its deficiency has been implicated in several pathologies such as colorectal inflammation. The renin-angiotensin system(RAS) is an essential regulatory cascade operating both at a local tissue level and at the systemic or circulatory level. The RAS may be important in the pathogenesis of chronic liver disease and is associated with the up-regulation of ACE2. Thus, the aim of this review is firstly, the analysis of some important general and genome characteristics of SARS-CoV-2 and secondly, and most importantly, to focus on the utility of ACE2 receptors in both SARS-CoV-2 replication and pathogenesis, especially in the GI tract.展开更多
Neuroendocrine tumors of the gastrointestinal tract are rare neoplasms. Rectal neuroendocrine tumors consist approximately the 5%-14% of all neuroendocrine neoplasms in Europe. These tumors are diagnosed in relatively...Neuroendocrine tumors of the gastrointestinal tract are rare neoplasms. Rectal neuroendocrine tumors consist approximately the 5%-14% of all neuroendocrine neoplasms in Europe. These tumors are diagnosed in relatively young patients,with a mean age at diagnosis of 56 years. Distant metastases from rectal neuroendocrine tumors are not very common. Herein we describe a case of a rectal neuroendocrine tumor which metastasized to the lung,mediastinum and orbit. This case underscores the importance of early identification and optimal management to improve patient's prognosis. Therefore,the clinical significance of this case is the necessity of physicians' awareness and education regarding neuroendocrine tumors' diagnosis and management.展开更多
Colorectal cancer(CRC) is one of the most prevalent malignancies in the world. CRC-associated morbidity and mortality is continuously increasing, in part due to a lack of early detection. The existing screening tools ...Colorectal cancer(CRC) is one of the most prevalent malignancies in the world. CRC-associated morbidity and mortality is continuously increasing, in part due to a lack of early detection. The existing screening tools such as colonoscopy, are invasive and yet high cost, affecting the willingness of patients to participate in screening programs. In recent years, evidence is accumulating that the interaction of aberrant genetic and epigenetic modifications is the cornerstone for the CRC development and progression by alternating the function of tumor suppressor genes, DNA repair genes and oncogenes of colonic cells. Apart from the understanding of the underlying mechanism(s) of carcinogenesis, the aforementioned interaction has also allowed identification of clinical biomarkers, especially epigenetic, for the early detection and prognosis of cancer patients. One of the ways to detect these epigenetic biomarkers is the cell-free circulating DNA(circ DNA), a blood-based cancer diagnostic test, mainly focusing in the molecular alterations found in tumor cells, such as DNA mutations and DNA methylation.In this brief review, we epitomize the current knowledge on the research in circ DNA biomarkers-mainly focusing on DNA methylation-as potential blood-based tests for early detection of colorectal cancer and the challenges for validation and globally implementation of this emergent technology.展开更多
Patients with long-standing ulcerative colitis(UC) and extensive Crohn's colitis(CC) are at increased risk for dysplasia and colorectal cancer(CRC). Several studies have shown that UC extending proximal to the rec...Patients with long-standing ulcerative colitis(UC) and extensive Crohn's colitis(CC) are at increased risk for dysplasia and colorectal cancer(CRC). Several studies have shown that UC extending proximal to the rectum, CC involving at least 1/3 of the colon, co-existence of primary sclerosing cholangitis, undetermined or unclassified colitis, family history of CRC and young age at diagnosis appear to be independent risk factors for inflammatory bowel disease(IBD)-related CRC. Therefore, screening and surveillance for CRC in IBD patients is highly recommended by international and national guidelines, whilst colonoscopy remains the unequivocal tool in order to detect potentially resectable dysplastic lesions or CRC at an early stage. Although the importance of screening and surveillance is widely proven, there is a controversy regarding the time of the first colonoscopy and the criteria of who should undergo surveillance. In addition, there are different recommendations among scientific societies concerning which endoscopic method is more efficient to detect dysplasia early, as well as the terminology for reporting visible lesions and the management of those lesions. This article concisely presents the main endoscopic methods and techniques performed for detecting dysplasia and CRC surveillance in patients with IBD focusing on their evidence-based accuracy and efficiency, as well as their cost-effectiveness. Finally, newer methods are mentioned, highlighting their applicability in daily endoscopic practice.展开更多
文摘Helicobacter pylori infection(Hp-I)represents a typical microbial agent intervening in the complex mechanisms of gastric homeostasis by disturbing the balance between the host gastric microbiota and mucosa-related factors,leading to inflammatory changes,dysbiosis and eventually gastric cancer.The normal gastric microbiota shows diversity,with Proteobacteria[Helicobacter pylori(H.pylori)belongs to this family],Firmicutes,Actinobacteria,Bacteroides and Fusobacteria being the most abundant phyla.Most studies indicate that H.pylori has inhibitory effects on the colonization of other bacteria,harboring a lower diversity of them in the stomach.When comparing the healthy with the diseased stomach,there is a change in the composition of the gastric microbiome with increasing abundance of H.pylori(where present)in the gastritis stage,while as the gastric carcinogenesis cascade progresses to gastric cancer,the oral and intestinal-type pathogenic microbial strains predominate.Hp-I creates a premalignant environment of atrophy and intestinal metaplasia and the subsequent alteration in gastric microbiota seems to play a crucial role in gastric tumorigenesis itself.Successful H.pylori eradication is suggested to restore gastric microbiota,at least in primary stages.It is more than clear that Hp-I,gastric microbiota and gastric cancer constitute a challenging tangle and the strong interaction between them makes it difficult to unroll.Future studies are considered of crucial importance to test the complex interaction on the modulation of the gastric microbiota by H.pylori as well as on the relationships between the gastric microbiota and gastric carcinogenesis.
文摘The pandemic of coronavirus disease 2019(COVID-19),caused by a newly identifiedβ-coronavirus(SARS-CoV-2)has emerged as a dire health problem,causing a massive crisis for global health.Primary method of transmission was firstly thought to be animal to human transmission.However,it has been observed that the virus is transmitted from human to human via respiratory droplets.Interestingly,SARS-CoV-2 ribonucleic acid(RNA)has been isolated from patient stools,suggesting a possible gastrointestinal(GI)involvement.Most commonly reported clinical manifestations are fever,fatigue and dry cough.Interestingly,a small percentage of patients experience GI symptoms with the most common being anorexia,diarrhea,nausea and vomiting.The presence of viral RNA in stools is also common and fecal tests can be positive even after negative respiratory samples.The exact incidence of digestive symptoms is a matter of debate.The distribution of Angiotensin converting enzyme type 2 receptors in multiple organs in the body provides a possible explanation for the digestive symptoms’mechanism.Cases with solely GI symptoms have been reported in both adults and children.Viral RNA has also been detected in stool and blood samples,indicating the possibility of liver damage,which has been reported in COVID-19 patients.The presence of chronic liver disease appears to be a risk factor for severe complications and a poorer prognosis,however data from these cases is lacking.The aim of this review is firstly,to briefly update what is known about the origin and the transmission of SARS-CoV-2,but mainly to focus on the manifestations of the GI tract and their pathophysiological background,so that physicians on the one hand,not to underestimate or disregard digestive symptoms due to the small number of patients exhibiting exclusively this symptomatology and on the other,to have SARS-CoV-2 on their mind when the“gastroenteritis”type symptoms predominate.
文摘Pancreatic cancer is one of the highest and in fact,unchanged mortality-associated tumor,with an exceptionally low survival rate due to its challenging diagnostic approach.So far,its treatment is based on a combination of approaches(such as surgical resection with or rarely without chemotherapeutic agents),but with finite limits.Thus,looking for additional space to improve pancreatic tumorigenesis therapeutic approach,research has focused on gene therapy with unexpectedly growing horizons not only for the treatment of inoperable pancreatic disease,but also for its early stages.In vivo gene delivery viral vectors,despite few disadvantages(possible immunogenicity,toxicity,mutagenicity,or high cost),could be one of the most efficient cancer gene therapeutic strategies for clinical application due to their superiority compared with other systems(ex vivo delivery strategies).Their dominance consists of simple preparation,easy operation and a wide range of functions.Adenoviruses are one of the most common used vectors,inducing strong immune as well as inflammatory reactions.Oncolytic virotherapy,using the above mentioned in vivo viral vectors,is one of the most promising nonpathogenic,highly-selective cytotoxic anti-cancer therapy using anti-cancer agents with high anti-tumor potency and strong oncolytic effect.There have been a variety of targeted therapeutic and pre-clinical strategies tested for gene therapy in pancreatic cancer such as gene-editing systems(e.g.,clustered regularly interspaced palindromic repeats-Cas9),RNA interference technology(e.g.,microRNAs,short hairpin RNA or small interfering RNA),adoptive immunotherapy and vaccination(e.g.,chimeric antigen receptor T-cell therapy)with encouraging results.
文摘The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was considered a zoonotic disease, the virus has also spread among humans via respiratory secretions. The expression and distribution of angiotensin converting enzyme type 2(ACE2) in various human organs might also show other possible infection routes. High ACE2 ribonucleic acid expression has been identified in the gastrointestinal tract(GI) indicating its importance as a possible infection pathway of SARS-CoV-2. ACE2 induces viral entry into the host and most importantly has been found to be associated with the function of the gut. Its deficiency has been implicated in several pathologies such as colorectal inflammation. The renin-angiotensin system(RAS) is an essential regulatory cascade operating both at a local tissue level and at the systemic or circulatory level. The RAS may be important in the pathogenesis of chronic liver disease and is associated with the up-regulation of ACE2. Thus, the aim of this review is firstly, the analysis of some important general and genome characteristics of SARS-CoV-2 and secondly, and most importantly, to focus on the utility of ACE2 receptors in both SARS-CoV-2 replication and pathogenesis, especially in the GI tract.
文摘Neuroendocrine tumors of the gastrointestinal tract are rare neoplasms. Rectal neuroendocrine tumors consist approximately the 5%-14% of all neuroendocrine neoplasms in Europe. These tumors are diagnosed in relatively young patients,with a mean age at diagnosis of 56 years. Distant metastases from rectal neuroendocrine tumors are not very common. Herein we describe a case of a rectal neuroendocrine tumor which metastasized to the lung,mediastinum and orbit. This case underscores the importance of early identification and optimal management to improve patient's prognosis. Therefore,the clinical significance of this case is the necessity of physicians' awareness and education regarding neuroendocrine tumors' diagnosis and management.
文摘Colorectal cancer(CRC) is one of the most prevalent malignancies in the world. CRC-associated morbidity and mortality is continuously increasing, in part due to a lack of early detection. The existing screening tools such as colonoscopy, are invasive and yet high cost, affecting the willingness of patients to participate in screening programs. In recent years, evidence is accumulating that the interaction of aberrant genetic and epigenetic modifications is the cornerstone for the CRC development and progression by alternating the function of tumor suppressor genes, DNA repair genes and oncogenes of colonic cells. Apart from the understanding of the underlying mechanism(s) of carcinogenesis, the aforementioned interaction has also allowed identification of clinical biomarkers, especially epigenetic, for the early detection and prognosis of cancer patients. One of the ways to detect these epigenetic biomarkers is the cell-free circulating DNA(circ DNA), a blood-based cancer diagnostic test, mainly focusing in the molecular alterations found in tumor cells, such as DNA mutations and DNA methylation.In this brief review, we epitomize the current knowledge on the research in circ DNA biomarkers-mainly focusing on DNA methylation-as potential blood-based tests for early detection of colorectal cancer and the challenges for validation and globally implementation of this emergent technology.
文摘Patients with long-standing ulcerative colitis(UC) and extensive Crohn's colitis(CC) are at increased risk for dysplasia and colorectal cancer(CRC). Several studies have shown that UC extending proximal to the rectum, CC involving at least 1/3 of the colon, co-existence of primary sclerosing cholangitis, undetermined or unclassified colitis, family history of CRC and young age at diagnosis appear to be independent risk factors for inflammatory bowel disease(IBD)-related CRC. Therefore, screening and surveillance for CRC in IBD patients is highly recommended by international and national guidelines, whilst colonoscopy remains the unequivocal tool in order to detect potentially resectable dysplastic lesions or CRC at an early stage. Although the importance of screening and surveillance is widely proven, there is a controversy regarding the time of the first colonoscopy and the criteria of who should undergo surveillance. In addition, there are different recommendations among scientific societies concerning which endoscopic method is more efficient to detect dysplasia early, as well as the terminology for reporting visible lesions and the management of those lesions. This article concisely presents the main endoscopic methods and techniques performed for detecting dysplasia and CRC surveillance in patients with IBD focusing on their evidence-based accuracy and efficiency, as well as their cost-effectiveness. Finally, newer methods are mentioned, highlighting their applicability in daily endoscopic practice.
