Acanthamoeba cysts are resistant to unfavorable physiological conditions and various disinfectants. Acanthamoeba cysts have 2 walls containing various sugar moieties, and in particular, one third of the inner wall is composed of cellulose. In this study, it has been shown that down-regulation of cellulose synthase by small interfering RNA (siRNA) significantly inhibits the formation of mature Acanthamoeba castellanii cysts. Calcofluor white staining and transmission electron microscopy revealed that siRNA transfected amoeba failed to form an inner wall during encystation and thus are likely to be more vulnerable. In addition, the expression of xylose isomerase, which is involved in cyst wall formation, was not altered in cellulose synthase down-regulated amoeba, indicating that cellulose synthase is a crucial factor for inner wall formation by Acanthamoeba during encystation.
Acanthamoeba castellanii/*enzymology/genetics/metabolism ; Aldose-Ketose Isomerases/*biosynthesis ; Amebiasis/*pathology ; Benzenesulfonates ; Cell Wall/chemistry/genetics/*metabolism ; Cellulose/biosynthesis ; Down-Regulation ; Encephalitis/parasitology ; Glucosyltransferases/*biosynthesis/genetics ; Keratitis/parasitology ; Microscopy, Electron, Transmission ; RNA Interference ; RNA, Small Interfering

Babesia gibsoni is an intraerythrocytic apicomplexan parasite that causes piroplasmosis in dogs. B. gibsoni infection is characterized clinically by fever, regenerative anemia, splenomegaly, and sometimes death. Since no vaccine is available, rapid and accurate diagnosis and prompt treatment of infected animals are required to control this disease. Over the past decade, several candidate molecules have been identified using biomolecular techniques in the authors' laboratory for the development of a serodiagnostic method, vaccine, and drug for B. gibsoni. This review article describes newly identified candidate molecules and their applications for diagnosis, vaccine production, and drug development of B. gibsoni.
Animals ; Antigens, Protozoan/*diagnostic use/*immunology ; Antiprotozoal Agents/*isolation & purification/pharmacology ; Babesia/*drug effects/immunology/*isolation & purification ; Babesiosis/*diagnosis/drug therapy/prevention & control ; Dogs ; Drug Discovery/methods ; Protozoan Vaccines/*immunology

Encystation is an essential process for Acanthamoeba survival under nutrient-limiting conditions and exposure to drugs. The expression of several genes has been observed to increase or decrease during encystation. Epigenetic processes involved in regulation of gene expression have been shown to play a role in several pathogenic parasites. In the present study, we identified the protein arginine methyltransferase 5 (PRMT5), a known epigenetic regulator, in Acanthamoeba castellanii. PRMT5 of A. castellanii (AcPRMT5) contained domains found in S-adenosylmethionine-dependent methyltransferases and in PRMT5 arginine-N-methyltransferase. Expression levels of AcPRMT5 were increased during encystation of A. castellanii. The EGFP-PRMT5 fusion protein was mainly localized in the nucleus of trophozoites. A. castellanii transfected with siRNA designed against AcPRMT5 failed to form mature cysts. The findings of this study lead to a better understanding of epigenetic mechanisms behind the regulation of encystation in cyst-forming pathogenic protozoa.
Acanthamoeba castellanii ; Acanthamoeba* ; Epigenesis, Genetic ; Epigenomics ; Gene Expression Regulation ; Methyltransferases ; Parasites ; Protein-Arginine N-Methyltransferases* ; RNA, Small Interfering ; Trophozoites

Diphyllobothrium latum and Diphyllobothrium nihonkaiense are the 2 reported main causes of human diphyllobothriasis in the Republic of Korea. However, the differentiation of these 2 species based on morphologic features alone is difficult. The authors used nucleotide sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene to diagnose Diphyllobothrium spp. Two patients visited the emergency room at Kyungpook National University Hospital on 3 April and 12 April 2013, respectively, with fragments of parasites found while defecating. The parasites were identified as Diphyllobothrium spp. based on morphologic characteristics, and subsequent cox1 gene sequencing showed 99.9% similarity (1,478/1,480 bp) with D. nihonkaiense. Our findings support the hypothesis that D. nihonkaiense is a dominant species in Korea.
Adult ; Animals ; Anthelmintics/therapeutic use ; Base Sequence ; DNA, Helminth/*genetics ; Diphyllobothriasis/*diagnosis/drug therapy ; Diphyllobothrium/*genetics ; Electron Transport Complex IV/*genetics ; Humans ; Male ; Middle Aged ; Mitochondria/enzymology ; Phylogeny ; Praziquantel/therapeutic use ; Republic of Korea ; Sequence Analysis, DNA ; Young Adult

Strongyloides stercoralis can cause systemic infection, termed strongyloidiasis, and gastrointestinal ulcer disease in immunocompromised patients. However, to our knowledge, there are no reported cases of comorbid gastric adenocarcinoma and S. stercoralis infection. Here, we report a case of an 81-year-old Korean man who presented with S. stercoralis infection coexisting with early gastric adenocarcinoma (T1aN0M0). S. stercoralis eggs, rhabditiform larvae, and adult females were observed in normal gastric and duodenal crypts. They were also observed in atypical glands representative of adenocarcinoma and adenoma. Preliminary laboratory tests revealed mild neutrophilic and eosinophilic leukocytosis. A routine stool test failed to detect rhabditiform larvae in the patient's fecal sample; however, S. stercoralis was identified by PCR amplification and 18S rRNA sequencing using genomic DNA extracted from formalin-fixed paraffin-embedded tissues. Postoperatively, the patient had a persistent fever and was treated with albendazole for 7 days, which alleviated the fever. The patient was followed-up by monitoring and laboratory testing for 4 months postoperatively, and no abnormalities were observed thus far. The fact that S. stercoralis infection may be fatal in immunocompromised patients should be kept in mind when assessing high-risk patients.
Adenocarcinoma/*complications/*diagnosis/pathology ; Aged, 80 and over ; Albendazole/therapeutic use ; Animals ; Anthelmintics/therapeutic use ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Endoscopy, Digestive System ; Female ; Histocytochemistry ; Humans ; Korea ; Male ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Stomach Neoplasms/*complications/*diagnosis/pathology ; Strongyloides stercoralis/*isolation & purification ; Strongyloidiasis/*complications/*diagnosis/drug therapy/pathology ; Treatment Outcome

Strongyloides stercoralis can cause systemic infection, termed strongyloidiasis, and gastrointestinal ulcer disease in immunocompromised patients. However, to our knowledge, there are no reported cases of comorbid gastric adenocarcinoma and S. stercoralis infection. Here, we report a case of an 81-year-old Korean man who presented with S. stercoralis infection coexisting with early gastric adenocarcinoma (T1aN0M0). S. stercoralis eggs, rhabditiform larvae, and adult females were observed in normal gastric and duodenal crypts. They were also observed in atypical glands representative of adenocarcinoma and adenoma. Preliminary laboratory tests revealed mild neutrophilic and eosinophilic leukocytosis. A routine stool test failed to detect rhabditiform larvae in the patient's fecal sample; however, S. stercoralis was identified by PCR amplification and 18S rRNA sequencing using genomic DNA extracted from formalin-fixed paraffin-embedded tissues. Postoperatively, the patient had a persistent fever and was treated with albendazole for 7 days, which alleviated the fever. The patient was followed-up by monitoring and laboratory testing for 4 months postoperatively, and no abnormalities were observed thus far. The fact that S. stercoralis infection may be fatal in immunocompromised patients should be kept in mind when assessing high-risk patients.
Adenocarcinoma/*complications/*diagnosis/pathology ; Aged, 80 and over ; Albendazole/therapeutic use ; Animals ; Anthelmintics/therapeutic use ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Endoscopy, Digestive System ; Female ; Histocytochemistry ; Humans ; Korea ; Male ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Stomach Neoplasms/*complications/*diagnosis/pathology ; Strongyloides stercoralis/*isolation & purification ; Strongyloidiasis/*complications/*diagnosis/drug therapy/pathology ; Treatment Outcome

PURPOSE: The aim of this report was to describe a new reconstructive technique of pancreaticogastrostomy and to also discuss this procedure's effectiveness for reducing the incidence of postoperative complications. METHODS: We retrospectively analyzed early surgical outcomes in 21 consecutive patients who underwent this novel pancreaticogastrostomy after pancreaticoduodenectomy. Pancreaticogastrostomy was completed with 2 transpancreatic sutures with buttresses on both the upper and lower edges of the implanted pancreas through the retracted anterior gastrotomy. RESULTS: Operative mortality was zero and morbidity was 23.8%. A significant pancreatic fistula occurred in 1 patient (4.7%; grade B). CONCLUSION: This technique is very easy to perform, less traumatic to the pancreatic stump, can be performed through a mini-laparotomy due to good vision and straight sutures, and it is secure owing to anchoring of the invaginated pancreatic stump to the stomach's posterior wall with buttresses. The results of this pilot study indicate that the technique may provide a favorable outcome and could be an alternative method of pancreatoenteric anastomosis. However, to determine its superiority over the conventional procedures, this operative technique should be evaluated more comprehensively in a larger series.
Humans ; Incidence ; Pancreas ; Pancreatic Fistula ; Pancreaticoduodenectomy ; Pilot Projects ; Retrospective Studies ; Sutures ; Vision, Ocular

PURPOSE: The aim of this report was to describe a new reconstructive technique of pancreaticogastrostomy and to also discuss this procedure's effectiveness for reducing the incidence of postoperative complications. METHODS: We retrospectively analyzed early surgical outcomes in 21 consecutive patients who underwent this novel pancreaticogastrostomy after pancreaticoduodenectomy. Pancreaticogastrostomy was completed with 2 transpancreatic sutures with buttresses on both the upper and lower edges of the implanted pancreas through the retracted anterior gastrotomy. RESULTS: Operative mortality was zero and morbidity was 23.8%. A significant pancreatic fistula occurred in 1 patient (4.7%; grade B). CONCLUSION: This technique is very easy to perform, less traumatic to the pancreatic stump, can be performed through a mini-laparotomy due to good vision and straight sutures, and it is secure owing to anchoring of the invaginated pancreatic stump to the stomach's posterior wall with buttresses. The results of this pilot study indicate that the technique may provide a favorable outcome and could be an alternative method of pancreatoenteric anastomosis. However, to determine its superiority over the conventional procedures, this operative technique should be evaluated more comprehensively in a larger series.
Humans ; Incidence ; Pancreas ; Pancreatic Fistula ; Pancreaticoduodenectomy ; Pilot Projects ; Retrospective Studies ; Sutures ; Vision, Ocular

PURPOSE: To evaluate the usefulness of percutaneous management and prognosis in venous rupture during angioplasty of hemodialytic arteriovenous fistulas. MATERIALS AND METHODS: Among 814 patients who underwent angioplasty on account of inadequate hemodialysis, 63[39 women and 24 men aged 20-78 (mean, 55.8) years] were included in this study. All 63 had peripheral venous stenosis. Venous rupture was diagnosed when contrast leakage was seen at venography after percutaneous angioplasty (PTA). In order to manage venous rupture, the sites at which this occurred were compressed manually for 3-5 minutes or blood flow was blocked with a balloon catheter for the same period. In one case, a stent was inserted at the rupture site. Using the Kaplan-Meier method, we investigated the patency rate of arteriovenous fistula (AVF) in cases of successful PTA. We also compared PTA patency rates in cases with and without peripheral venous rupture. RESULTS: Venous rupture occurred in 38 cephalic, 16 brachial, and 9 basilic veins. In 63 patients, bleeding stopped and in 54 (85.7%) of these, PTA was successful. Among the nine failed cases, dilatation was incomplete in five, though bleeding had stopped. In patients with brachial and cephalic vein rupture, the venous tract at the rupture site was not located. Two patients underwent surgery: one of these experienced brachial venous rupture, with incontrollable bleeding, and the other had nerve compression symptoms due to hematoma. Among 54 patients in whom PTA was successful, the primary and secondary six-month rates for angioaccess were 47.9% and 81.2%, and the mean patency period was 6.1 and 15.8 months, respectively. In cases of non-venous rupture, the mean patency period was 9.6 months, significantly longer than in cases involving venous rupture (p=0.02). CONCLUSION: Venous rupture occurring during the PTA of hemodialytic AVF can be managed percutaneously.
Angioplasty* ; Arteriovenous Fistula ; Catheters ; Constriction, Pathologic ; Dilatation ; Female ; Hematoma ; Hemorrhage ; Humans ; Male ; Ocimum basilicum ; Phlebography ; Prognosis ; Renal Dialysis* ; Rupture* ; Stents ; Veins

BACKGROUND/AIMS: Liver transplant patients are at high risk for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) colonization. We evaluated patients before and after liver transplant using active surveillance culture (ASC) to assess the prevalence of MRSA and VRE and to determine the effect of bacterial colonization on patient outcome. METHODS: We performed ASC on 162 liver transplant recipients at the time of transplantation and 7 days posttransplantation to monitor the prevalence of MRSA and VRE. RESULTS: A total of 142 patients had both nasal and rectal ASCs. Of these patients, MRSA was isolated from 12 (7.4%) at the time of transplantation (group 1a), 9 (6.9%) acquired MRSA posttransplantation (group 2a), and 121 did not test positive for MRSA at either time (group 3a). Among the three groups, group 1a patients had the highest frequency of developing a MRSA infection (p < 0.01); however, group 2a patients had the highest mortality rate associated with MRSA infection (p = 0.05). Of the 142 patients, VRE colonization was detected in 37 patients (22.8%) at the time of transplantation (group 1b), 21 patients (20%) acquired VRE posttransplantation (group 2b), and 84 patients did not test positive for VRE at either time (group 3b). Among these three groups, group 2b patients had the highest frequency of VRE infections (p < 0.01) and mortality (p = 0.04). CONCLUSIONS: Patients that acquired VRE or MRSA posttransplantation had higher mortality rates than did those who were colonized pre-transplantation or those who never acquired the pathogens. Our findings highlight the importance of preventing the acquisition of MRSA and VRE posttransplantation to reduce infections and mortality among liver transplant recipients.
Adult ; Enterococcus/*isolation & purification ; Female ; Gram-Positive Bacterial Infections/diagnosis/*microbiology/mortality/transmission ; Humans ; Liver Transplantation/*adverse effects/mortality ; Male ; Methicillin-Resistant Staphylococcus aureus/*isolation & purification ; Middle Aged ; Prevalence ; Prospective Studies ; Republic of Korea/epidemiology ; Risk Factors ; Staphylococcal Infections/diagnosis/*microbiology/mortality/transmission ; Time Factors ; Treatment Outcome ; *Vancomycin Resistance