Amebic liver abscess(ALA)is still a common problem in the tropical world,where it affects over three-quarters of patients with liver abscess.It is caused by an anaerobic protozoan Entamoeba hystolytica,which primarily...Amebic liver abscess(ALA)is still a common problem in the tropical world,where it affects over three-quarters of patients with liver abscess.It is caused by an anaerobic protozoan Entamoeba hystolytica,which primarily colonises the cecum.It is a non-suppurative infection of the liver consisting primarily of dead hepatocytes and cellular debris.People of the male gender,during their reproductive years,are most prone to ALA,and this appears to be due to a poorly mounted immune response linked to serum testosterone levels.ALA is more common in the right lobe of the liver,is strongly associated with alcohol consumption,and can heal without the need for drainage.While majority of ALA patients have an uncomplicated course,a number of complications have been described,including rupture into abdomino-thoracic structures,biliary fistula,vascular thrombosis,bilio-vascular compression,and secondary bacterial infection.Based on clinico-radiological findings,a classification system for ALA has emerged recently,which can assist clinicians in making treatment decisions.Recent research has revealed the role of venous thrombosis-related ischemia in the severity of ALA.Recent years have seen the development and refinement of newer molecular diagnostic techniques that can greatly aid in overcoming the diagnostic challenge in endemic area where serology-based tests have limited accuracy.Metronidazole has been the drug of choice for ALA patients for many years.However,concerns over the resistance and adverse effects necessitate the creation of new,safe,and potent antiamebic medications.Although the indication of the drainage of uncomplicated ALA has become more clear,high-quality randomised trials are still necessary for robust conclusions.Percutaneous drainage appears to be a viable option for patients with ruptured ALA and diffuse peritonitis,for whom surgery represents a significant risk of mortality.With regard to all of the aforementioned issues,this article intends to present an updated review of ALA.展开更多
Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.hist...Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.histolytica hemolysin gene HLY6.Genomic DNA of E.histolytica trophozoites strain HK9 was used to optimize the LAMP mixture and conditions.Amplification of DNA in the LAMP mixture was monitored through visual inspection for turbidity of the LAMP mix as well as addition of fluorescent dye.Results:Positive LAMP reactions turned turbid while negative ones remained clear.Upon addition of a fluorescent dye,all positive reactions turned green while the negative control remained orange under ambient light After elecrophoresis in 1.5% agarose gels,a ladder of multiple bands of different sizes can be oliserved in positive samples while no bands were detected in the negative control.The sensitivity of the assay was found to be S parasites per reaction which corresponds to approximately 1S.8 ng/μL DNA.The specificity of the assay was verified by the absence of amplified products when DNA from other gastrointestinal parasites such as the morphologically similar but non-pathogenic species,Entamoeba dispar. and other diarrhea-causing organisms such as Blastocystis hominis and Escherichia coli were used.Conclusions:The I.AMP assay we have developed enables the detection of E.histolytica with rapidity and ease,therefore rendering it is suitable for laboratory and field diagnosis of amebiasis.展开更多
Entameba histolytica is a protozoan that usually causes procto-colitis. E. histolytica amebiasis is endemic in tropical countries but exceedingly rare in the US Amebic liver abscess commonly presents with fever, abdom...Entameba histolytica is a protozoan that usually causes procto-colitis. E. histolytica amebiasis is endemic in tropical countries but exceedingly rare in the US Amebic liver abscess commonly presents with fever, abdominal distension, right upper quadrant pain/tenderness, hepatomegaly, and tachycardia. We discuss the presentation/diagnosis of amebiasis in a child who had visited Mexico and the difficulty of early diagnosis when there is no evidence of intestinal infection. Ultrasonography and/or CT were essential diagnostic tools and an IgG antibody study confirmed the diagnosis. Management included oral metronida-zole and abscess drainage.展开更多
Amebiasis is a parasitic infection caused by the protozoa Entamoeba histolytica. It is capable of causing a spectrum of illnesses from asymptomatic infection, to dysentery and invasive extra-intestinal conditions, the...Amebiasis is a parasitic infection caused by the protozoa Entamoeba histolytica. It is capable of causing a spectrum of illnesses from asymptomatic infection, to dysentery and invasive extra-intestinal conditions, the most common of which is liver abscess. Here is presented the case of a 14-month old boy presented with Fever of Unknown Origin, which after work-up was diagnosed as amebic liver abscess. Although amebiasis is more prevalent in developing countries the increasing phenomena of migration and tourism has transformed it into a global health issue. It is recommended to maintain a high index of suspicion while valuating a child with Fever of Unknown Origin.展开更多
Amebiasis is uncommon in developed countries. Several case reports in the literature emphasize that both the presenting symptoms and the radiological findings of colonic amebiasis closely resemble more common conditio...Amebiasis is uncommon in developed countries. Several case reports in the literature emphasize that both the presenting symptoms and the radiological findings of colonic amebiasis closely resemble more common conditions, such as idiopathic inflammatory bowel disease and gastro-intestinal malignancy. We describe a unique case of colonic amebiasis(amebomas) coexisting with signet-ring cell carcinoma of the ileocecal valve, the cecum and the appendix. Endoscopically, the ulcerated tumor was indistinguishable from the ulcerations and pseudotumors(amebomas) detected in the ascending colon. Histological examination of biopsy specimens revealed the pathognomonic features of protozoa with ingested erythrocytes in combination with signet-ring cell infiltration. The author concludes that amebiasis may not only mimic carcinoma but, rarely, may coexist with carcinoma in the same patient. Clinicians and pathologists should be aware of this possibility in order not to delay diagnosis and treatment of malignant disease.展开更多
AIM. To assess the causes of ileocecal mass in patients with amebic liver abscess. METHODS： Patients with amebic liver abscess and ileocecal mass were carefully examined and investigated by contrast-enhanced CT scan ...AIM. To assess the causes of ileocecal mass in patients with amebic liver abscess. METHODS： Patients with amebic liver abscess and ileocecal mass were carefully examined and investigated by contrast-enhanced CT scan followed by colonoscopy and histological examination of biopsy materials from lesions during colonoscopy. RESULTS： Ileocecal masses were found in seventeen patients with amebic liver abscess. The cause of the mass was ameboma in 14 patients, cecal tuberculosis in 2 patients and adenocarcinoma of the cecum in 1 patient. Colonic ulcers were noted in five of the six （83%） patients with active diarrhea at presentation. The ileocecal mass in all these patients was ameboma. Ulcers were seen in only one of the 11 （9%） patients without diarrhea. The difference was statistically significant from the group with diarrhea （P〈 0.005）. CONCLUSION： Ileocecal mass is not an uncommon finding in patients with amebic liver abscess. Although, the ileocecal mass is due to ameboma formation in most cases, it should not be assumed that this is the case in all patients. Colonoscopy and histological examination of the target biopsies are mandatory to avoid missing a more sinister lesion.展开更多
Objective:To determine the level of oxygen-nitrogen stress parameters in the pathogenesis of amebiasis.Methods:Twenty-four acute intestinal amebiasis patients and 20 healthy controls were enrolled in the present study...Objective:To determine the level of oxygen-nitrogen stress parameters in the pathogenesis of amebiasis.Methods:Twenty-four acute intestinal amebiasis patients and 20 healthy controls were enrolled in the present study.Serum malondialdehyde and nitric oxide levels were determined spectrophotometrically.Results:Serum raalondialdehyde and nitric oxide levels were significantly higher in acute intestinal amebiasis patients than healthy controls(P<0.00l). Conclusions:These results suggest that oxidative and nitrosative stress may play a major role in tissue damage in acute intestinal amebiasis patients.Also these parameters can be used to supplement the conventional microscopic method for reliable diagnosis of intestinal amebiasis.展开更多
A 54-year-old man presented with rectal pain and bleeding secondary to ulcerated,necrotic rectal and cecal masses that resembled colorectal carcinoma upon colonoscopy.These masses were later determined to be benign am...A 54-year-old man presented with rectal pain and bleeding secondary to ulcerated,necrotic rectal and cecal masses that resembled colorectal carcinoma upon colonoscopy.These masses were later determined to be benign amebomas caused by invasive Entamoeba histolytica,which regressed completely with medical therapy.In Western countries,the occurrence of invasive protozoan infection with formation of amebomas is very rare and can mistakenly masquerade as a neoplasm.Not surprisingly,there have been very few cases reported of this clinical entity within the United States.Moreover,we report a patient that had an extremely rare occurrence of two synchronous lesions,one involving the rectum and the other situated in the cecum.We review the current literature on the pathogenesis of invasive E.histolytica infection and ameboma formation,as well as management of this rare disease entity at a western medical center.展开更多
Background:Primary pulmonary amoeba is very rare and here we report a case of a 68-year-old man presenting with primary pulmonary amoeba after undergoing chemotherapy for lung adenocarcinoma.Case presentation:In Octob...Background:Primary pulmonary amoeba is very rare and here we report a case of a 68-year-old man presenting with primary pulmonary amoeba after undergoing chemotherapy for lung adenocarcinoma.Case presentation:In October 2016,the man aged 68 was admitted to our hospital because of repeated cough for 8 months and hemoptysis for 1 month.He was diagnosed lung adenocarcinoma and underwent surgery in 2012 without receiving chemotherapy.In March 2016,the patients suffered recurrence of cancer and was treated with chemotherapy.After 2 months of chemotherapy,the patient had consistent cough with white sputum,and chest CT showed a local lung nodule.The physicians suspected that the patient had pulmonary infectious diseases,and he was treated with empirical antibacterial treatment.However,his symptom wasn’t relieved and later the percutaneous lung biopsy found trophozites of Entamoeba histolytica.After administration of metronidazole,the symptoms of the patient were markedly relieved and the lesions were absorbed.Conclusions:In such cases where patients with pulmonary nodules were in immunodeficiency state and had adequate but ineffective anti-bacterial treatment,Entamoeba histolytica infection could be one of the rare causes.Percutaneous lung biopsy should be recommended and specific dying for parasites should be done when necessary.展开更多
BACKGROUND Amebic colitis is an infection caused by Entamoeba histolytica and most commonly observed in regions with poor sanitation.It is also seen as a sexually transmitted disease in developed countries.While amebi...BACKGROUND Amebic colitis is an infection caused by Entamoeba histolytica and most commonly observed in regions with poor sanitation.It is also seen as a sexually transmitted disease in developed countries.While amebic colitis usually has a chronic course with repeated exacerbations and remissions,it may also manifest as a fulminant form that rapidly progresses and leads to severe,life-threatening complications,such as intestinal perforation,peritonitis,and sepsis,that have a high mortality rate.CASE SUMMARY A 68-year-old man was admitted to our hospital with chest pain and acute dyspnea.He was diagnosed with acute coronary syndrome,acute heart failure,and bacterial pneumonia.His respiratory condition worsened despite receiving intensive care and intravenous antibiotics.On the fifth day of hospitalization,he was diagnosed with acute respiratory distress syndrome and was started on steroid therapy.He subsequently developed bloody stools and was diagnosed with cytomegalovirus(CMV)enterocolitis based on biopsy results and a peripheral blood CMV pp65 antigenemia test result.Although we started antiviral therapy with ganciclovir,which was successful in reducing his antigen titers,he continued to have bloody diarrhea.Three weeks after initiation of ganciclovir therapy and six weeks after his admission,the patient died from intestinal perforation.We only posthumously diagnosed him with amebic colitis and CMV enterocolitis based on autopsy findings of transmural necrosis of the entire colon with massive ameba infiltration.CONCLUSION We urge clinicians to consider Entamoeba histolytica infection if severe colitis progresses after steroid therapy.Preemptive treatment is recommended then.展开更多
文摘Amebic liver abscess(ALA)is still a common problem in the tropical world,where it affects over three-quarters of patients with liver abscess.It is caused by an anaerobic protozoan Entamoeba hystolytica,which primarily colonises the cecum.It is a non-suppurative infection of the liver consisting primarily of dead hepatocytes and cellular debris.People of the male gender,during their reproductive years,are most prone to ALA,and this appears to be due to a poorly mounted immune response linked to serum testosterone levels.ALA is more common in the right lobe of the liver,is strongly associated with alcohol consumption,and can heal without the need for drainage.While majority of ALA patients have an uncomplicated course,a number of complications have been described,including rupture into abdomino-thoracic structures,biliary fistula,vascular thrombosis,bilio-vascular compression,and secondary bacterial infection.Based on clinico-radiological findings,a classification system for ALA has emerged recently,which can assist clinicians in making treatment decisions.Recent research has revealed the role of venous thrombosis-related ischemia in the severity of ALA.Recent years have seen the development and refinement of newer molecular diagnostic techniques that can greatly aid in overcoming the diagnostic challenge in endemic area where serology-based tests have limited accuracy.Metronidazole has been the drug of choice for ALA patients for many years.However,concerns over the resistance and adverse effects necessitate the creation of new,safe,and potent antiamebic medications.Although the indication of the drainage of uncomplicated ALA has become more clear,high-quality randomised trials are still necessary for robust conclusions.Percutaneous drainage appears to be a viable option for patients with ruptured ALA and diffuse peritonitis,for whom surgery represents a significant risk of mortality.With regard to all of the aforementioned issues,this article intends to present an updated review of ALA.
基金supported financially by a research grant from the Natural Sciences Research Institute,University of the Philippines ) BIO 1 l-l-05) to W.L.R.
文摘Objective:To develop a loop-mediated isothermal amplification(LAMP) assay for the detection of Entamoeba histolytica(E.histolytica),the causative agent of amebiasis.Methods:The LAMP primer set was designed from E.histolytica hemolysin gene HLY6.Genomic DNA of E.histolytica trophozoites strain HK9 was used to optimize the LAMP mixture and conditions.Amplification of DNA in the LAMP mixture was monitored through visual inspection for turbidity of the LAMP mix as well as addition of fluorescent dye.Results:Positive LAMP reactions turned turbid while negative ones remained clear.Upon addition of a fluorescent dye,all positive reactions turned green while the negative control remained orange under ambient light After elecrophoresis in 1.5% agarose gels,a ladder of multiple bands of different sizes can be oliserved in positive samples while no bands were detected in the negative control.The sensitivity of the assay was found to be S parasites per reaction which corresponds to approximately 1S.8 ng/μL DNA.The specificity of the assay was verified by the absence of amplified products when DNA from other gastrointestinal parasites such as the morphologically similar but non-pathogenic species,Entamoeba dispar. and other diarrhea-causing organisms such as Blastocystis hominis and Escherichia coli were used.Conclusions:The I.AMP assay we have developed enables the detection of E.histolytica with rapidity and ease,therefore rendering it is suitable for laboratory and field diagnosis of amebiasis.
文摘Entameba histolytica is a protozoan that usually causes procto-colitis. E. histolytica amebiasis is endemic in tropical countries but exceedingly rare in the US Amebic liver abscess commonly presents with fever, abdominal distension, right upper quadrant pain/tenderness, hepatomegaly, and tachycardia. We discuss the presentation/diagnosis of amebiasis in a child who had visited Mexico and the difficulty of early diagnosis when there is no evidence of intestinal infection. Ultrasonography and/or CT were essential diagnostic tools and an IgG antibody study confirmed the diagnosis. Management included oral metronida-zole and abscess drainage.
文摘Amebiasis is a parasitic infection caused by the protozoa Entamoeba histolytica. It is capable of causing a spectrum of illnesses from asymptomatic infection, to dysentery and invasive extra-intestinal conditions, the most common of which is liver abscess. Here is presented the case of a 14-month old boy presented with Fever of Unknown Origin, which after work-up was diagnosed as amebic liver abscess. Although amebiasis is more prevalent in developing countries the increasing phenomena of migration and tourism has transformed it into a global health issue. It is recommended to maintain a high index of suspicion while valuating a child with Fever of Unknown Origin.
文摘Amebiasis is uncommon in developed countries. Several case reports in the literature emphasize that both the presenting symptoms and the radiological findings of colonic amebiasis closely resemble more common conditions, such as idiopathic inflammatory bowel disease and gastro-intestinal malignancy. We describe a unique case of colonic amebiasis(amebomas) coexisting with signet-ring cell carcinoma of the ileocecal valve, the cecum and the appendix. Endoscopically, the ulcerated tumor was indistinguishable from the ulcerations and pseudotumors(amebomas) detected in the ascending colon. Histological examination of biopsy specimens revealed the pathognomonic features of protozoa with ingested erythrocytes in combination with signet-ring cell infiltration. The author concludes that amebiasis may not only mimic carcinoma but, rarely, may coexist with carcinoma in the same patient. Clinicians and pathologists should be aware of this possibility in order not to delay diagnosis and treatment of malignant disease.
文摘AIM. To assess the causes of ileocecal mass in patients with amebic liver abscess. METHODS： Patients with amebic liver abscess and ileocecal mass were carefully examined and investigated by contrast-enhanced CT scan followed by colonoscopy and histological examination of biopsy materials from lesions during colonoscopy. RESULTS： Ileocecal masses were found in seventeen patients with amebic liver abscess. The cause of the mass was ameboma in 14 patients, cecal tuberculosis in 2 patients and adenocarcinoma of the cecum in 1 patient. Colonic ulcers were noted in five of the six （83%） patients with active diarrhea at presentation. The ileocecal mass in all these patients was ameboma. Ulcers were seen in only one of the 11 （9%） patients without diarrhea. The difference was statistically significant from the group with diarrhea （P〈 0.005）. CONCLUSION： Ileocecal mass is not an uncommon finding in patients with amebic liver abscess. Although, the ileocecal mass is due to ameboma formation in most cases, it should not be assumed that this is the case in all patients. Colonoscopy and histological examination of the target biopsies are mandatory to avoid missing a more sinister lesion.
基金Supported by Scientific Research Projects Governing Unit ofGaziantep University(No.TF:00 04)
文摘Objective:To determine the level of oxygen-nitrogen stress parameters in the pathogenesis of amebiasis.Methods:Twenty-four acute intestinal amebiasis patients and 20 healthy controls were enrolled in the present study.Serum malondialdehyde and nitric oxide levels were determined spectrophotometrically.Results:Serum raalondialdehyde and nitric oxide levels were significantly higher in acute intestinal amebiasis patients than healthy controls(P<0.00l). Conclusions:These results suggest that oxidative and nitrosative stress may play a major role in tissue damage in acute intestinal amebiasis patients.Also these parameters can be used to supplement the conventional microscopic method for reliable diagnosis of intestinal amebiasis.
文摘A 54-year-old man presented with rectal pain and bleeding secondary to ulcerated,necrotic rectal and cecal masses that resembled colorectal carcinoma upon colonoscopy.These masses were later determined to be benign amebomas caused by invasive Entamoeba histolytica,which regressed completely with medical therapy.In Western countries,the occurrence of invasive protozoan infection with formation of amebomas is very rare and can mistakenly masquerade as a neoplasm.Not surprisingly,there have been very few cases reported of this clinical entity within the United States.Moreover,we report a patient that had an extremely rare occurrence of two synchronous lesions,one involving the rectum and the other situated in the cecum.We review the current literature on the pathogenesis of invasive E.histolytica infection and ameboma formation,as well as management of this rare disease entity at a western medical center.
文摘Background:Primary pulmonary amoeba is very rare and here we report a case of a 68-year-old man presenting with primary pulmonary amoeba after undergoing chemotherapy for lung adenocarcinoma.Case presentation:In October 2016,the man aged 68 was admitted to our hospital because of repeated cough for 8 months and hemoptysis for 1 month.He was diagnosed lung adenocarcinoma and underwent surgery in 2012 without receiving chemotherapy.In March 2016,the patients suffered recurrence of cancer and was treated with chemotherapy.After 2 months of chemotherapy,the patient had consistent cough with white sputum,and chest CT showed a local lung nodule.The physicians suspected that the patient had pulmonary infectious diseases,and he was treated with empirical antibacterial treatment.However,his symptom wasn’t relieved and later the percutaneous lung biopsy found trophozites of Entamoeba histolytica.After administration of metronidazole,the symptoms of the patient were markedly relieved and the lesions were absorbed.Conclusions:In such cases where patients with pulmonary nodules were in immunodeficiency state and had adequate but ineffective anti-bacterial treatment,Entamoeba histolytica infection could be one of the rare causes.Percutaneous lung biopsy should be recommended and specific dying for parasites should be done when necessary.
文摘BACKGROUND Amebic colitis is an infection caused by Entamoeba histolytica and most commonly observed in regions with poor sanitation.It is also seen as a sexually transmitted disease in developed countries.While amebic colitis usually has a chronic course with repeated exacerbations and remissions,it may also manifest as a fulminant form that rapidly progresses and leads to severe,life-threatening complications,such as intestinal perforation,peritonitis,and sepsis,that have a high mortality rate.CASE SUMMARY A 68-year-old man was admitted to our hospital with chest pain and acute dyspnea.He was diagnosed with acute coronary syndrome,acute heart failure,and bacterial pneumonia.His respiratory condition worsened despite receiving intensive care and intravenous antibiotics.On the fifth day of hospitalization,he was diagnosed with acute respiratory distress syndrome and was started on steroid therapy.He subsequently developed bloody stools and was diagnosed with cytomegalovirus(CMV)enterocolitis based on biopsy results and a peripheral blood CMV pp65 antigenemia test result.Although we started antiviral therapy with ganciclovir,which was successful in reducing his antigen titers,he continued to have bloody diarrhea.Three weeks after initiation of ganciclovir therapy and six weeks after his admission,the patient died from intestinal perforation.We only posthumously diagnosed him with amebic colitis and CMV enterocolitis based on autopsy findings of transmural necrosis of the entire colon with massive ameba infiltration.CONCLUSION We urge clinicians to consider Entamoeba histolytica infection if severe colitis progresses after steroid therapy.Preemptive treatment is recommended then.
