Clinico-pathological, parasitological, microbiological and immunologic studies were made in 238 of islanders Cheju, a highly endemic area of amebiasis in Korea. Ameba immobilization test was carried out using immunized rabbit sera and several strains of Entamoeba histolytica. The results are summarized and concluded as follows; I. The number of males with liver abscess was markedly greater than female, and the largest group distribution was observed in ages 30-39. In liver abscess patients, an increase of white blood cells(W.B.C.) and a decrease of red blood cells'R.B.C.) was noted. The differential count of W.B.C. showed an increase of segmented neutrophils and a decrease of 1ymphocytes. The level of total cholesterol and its ester was also diminished, and urobilinogen in patients, urine was increased in comparison with healthy controls. 2. The detection rate for microorganisms in aspirated liver abscess was 42.1%. Most of the recovered microorganisms were Gram negative enteric bacilli; Escherichia coli, Alkaligenes fecalis, Aerobacder aerogenes and paracolon group. Fungi and cocci were not observed. 3. In the immobilization test using immune rabbit sera immunized with a 48-hour-culture of E. histolytica, the highest immobilization reaction occurred 45-105 minutes after the beginning of the test and remobilization of the parasite took place gradually. Immobilization of ameba continued for more hours and at higher rate in the inactivated rabbit sera group, and the differences among ameba strains were not remarkable. In human amebiasis sera, the highest peak of immobilization reaction occurred at 45-90 minutes after testing with the parasite. 4. Positive rates for the immobilization test according to clinical feature were 83.3-100% in liver abscess cases, 83.3-90.7% in hepatomegaly cases, 45.4% in asymptomatic cyst-passers and 31.5% in healthy controls. 5. For 56 patients who showed a high rate of immobilization, the follow-up positive rate after treatment for amebiasis was markedly reduced in 2-3 months.
Adolescent ; Adult ; Animals ; Child ; Entamoeba histolytica/isolation & purification ; Female ; Human ; Korea ; Liver Abscess/*microbiology ; Liver Abscess, Amebic/immunology/*microbiology ; Male ; Middle Aged ; Serologic Tests

OBJECTIVETo compare the efficacy of three different tissue stains, namely haematoxylin and eosin (H&E), periodic-acid Schiff (PAS) and immunohistochemical (IHC) stains for detection of Entamoeba histolytica (E. histolytica) trophozoites in abscessed liver tissues of hamster.

METHODSAmoebic liver abscess was experimentally induced in a hamster by injecting 1 × 10(6) of axenically cultured virulent E. histolytica trophozoites (HM1-IMSS strain) into the portal vein. After a week post-inoculation, the hamster was sacrificed and the liver tissue sections were stained with H&E, PAS and IHC stains to detect the amoebic trophozoite.

RESULTSThe three stains revealed tissue necrosis and amoebic trophozoites, but with varying clarity. H&E and PAS stained the trophozoites pink and magenta, respectively, however it was difficult to differentiate the stained trophozoites from the macrophages because of their similarity in size and morphology. On the other hand, IHC stain revealed distinct brown appearance of the trophozoites in the infected liver tissues.

CONCLUSIONSIt can be concluded that out of the three stains, IHC is the best for identification of E. histolytica trophozoites in tissue sections.

Animals ; Disease Models, Animal ; Entamoeba histolytica ; cytology ; isolation & purification ; Histocytochemistry ; methods ; Immunohistochemistry ; methods ; Liver Abscess, Amebic ; diagnosis ; pathology ; Male ; Mesocricetus ; Microscopy ; Parasitology ; methods ; Staining and Labeling ; methods ; Trophozoites ; cytology

Amebiasis is a protozoan disease caused by Entamoeba histolytica and a potential health threat in areas where sanitation and hygiene are inappropriate. Highly sensitive PCR methods for detection of E. histolytica in clinical and environmental samples are extremely useful to control amebiasis and to promote public health. The present study compared several primer sets for small subunit (SSU) rDNA and histone genes of E. histolytica cysts. A 246 bp of the SSU rDNA gene of pure cysts contained in phosphate-buffered saline (PBS) and in stool samples was successfully amplified by nested PCR, using the 1,147-246 bp primer set, of the primary PCR products which were pre-amplified using the 1,147 bp primer as the template. The detection limit of the nested PCR using the 1,147-246 primer set was 10 cysts in both groups (PBS and stool samples). The PCR to detect histone gene showed negative results. We propose that the nested PCR technique to detect SSU rDNA can be used as a highly sensitive genetic method to detect E. histolytica cysts in stool samples.
DNA Primers/genetics ; DNA, Protozoan/genetics ; DNA, Ribosomal/genetics ; Entamoeba histolytica/genetics/*isolation & purification ; Entamoebiasis/*diagnosis ; Histones/genetics ; Humans ; Molecular Diagnostic Techniques/*methods ; Parasitology/*methods ; Polymerase Chain Reaction/*methods ; Protozoan Proteins/genetics ; Sensitivity and Specificity

This study investigated the effect of breast-feeding in protection against protozoan infection in infants with persistent diarrhea. Infants were classified into 2 groups; 161 breast-fed infants and the same number of non-breast-fed infants. Microscopic examinations of stool were done for detection of parasites and measuring the intensity of infection. Moreover, serum levels of IgE and TNF-alpha were measured by ELISA. Cryptosporidium spp., Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Blastocystis sp. were demonstrated in infants with persistent diarrhea. The percentage of protozoan infections was significantly lower in breast-fed infants than that in the non-breast-fed infants. The levels of IgE and TNF-alpha were significantly lower in the breast-fed group than in the non-breast-fed group. There were significant positive associations between the serum levels of IgE and TNF-alpha and the intensity of parasite infection in the breast-fed group. It is suggested that breast-feeding has an attenuating effect on the rate and intensity of parasite infection.
Antigens, Protozoan/analysis/*immunology ; Diarrhea, Infantile/*diagnosis/parasitology ; Entamoeba ; Entamoeba histolytica/*isolation & purification ; Entamoebiasis/*diagnosis/parasitology ; Enzyme-Linked Immunosorbent Assay ; Feces/parasitology ; Female ; Giardia lamblia ; Giardiasis/*diagnosis/parasitology ; Humans ; Infant ; Intestines/parasitology ; Protozoan Infections/*diagnosis/parasitology ; Tumor Necrosis Factor-alpha/metabolism