Intestinal microsporidiosis in HIV-infected children with diarrhea.

Intestinal microsporidiosis is a common opportunistic disease associated with diarrhea in adult AIDS patients in Thailand; the data regarding this infection in children are scarce. The present study was designed to investigate the prevalence and clinical features of intestinal microsporidiosis in hospitalized HIV-infected and uninfected (free of HIV) children with diarrhea. Of the 95 HIV-infected children and 87 uninfected children, 24 (25.3%) and 13 (14.9%) respectively were diagnosed with intestinal microsporidiosis. Species identification of microsporidia spores, by transmission electron microscopy, demonstrated Enterocytozoon bieneusi in 5 cases. Cryptosporidium parvum was a common coinfective parasite; pneumonia was the most frequent concurrent disease found in children with intestinal microsporidiosis. Malnutrition was commoner in the HIV-infected group (79.2% vs 23.1%; p = 0.003). This study indicates that intestinal microsporidiosis is an important disease in both HIV-infected and uninfected Thai children with diarrhea.

Ultrastructural features of sidero - apoptotic hepatocytes in thalassemia.

Liver tissues from 20 patients with thalassemia were investigated by light and electron microscopy, with focus on ultrastructure of sidero-apoptosis. The results of light microscopy were compared. Sidero-apoptosis was found in 82% in b thal/Hb E disease, 67% in thalassemia Hb H, 100% in and b-thal major, respectively. Regardless of the type of hemoglobin, sidero-apoptosis was present in various degrees. The main criteria used for identification of sidero-apoptosis were marked condensation of chromatin against the nuclear membrane, and fragmentation into nuclear fragments of varying sizes and structures into membrane-bounded sidero-apop-totic bodies. These bodies may be phagocytosed by macrophages or neighboring cells or remain free. However, the cell may also shrink into a dense, rounded mass, as a single sidero-apoptotic body. Sidero-apoptoic bodies were similar to acidophilic bodies, or Councilman bodies, commonly found in viral hepatitis. This preliminary report suggestsd that sidero-apoptosis is a features of human liver pathology in thalassemia and may be due to hepatotoxicity of iron overload. In addition, many factors or other agents-hormone, killer cells, cytokines, various physical, chemical and viral agents should be considered. We propose the term "sidero-apoptosis" to describe the features resenbling acidophilic bodies commonly seen in viral hepatitis but with a heavy depositi of iron.

Intestinal parasitic infections in HIV and non-HIV infected patients with chronic diarrhea in Thailand.

Chronic diarrhea is a common problem in AIDS patients, and enteric parasites are re-cognized as important causes. This study determined the prevalence of parasitic infections in HIV infected patients with chronic diarrhea. Ninety-one patients with AIDS who presented with chronic diarrhea and 103 patients who were HIV negative were enrolled in the study. Detection of stool parasites was made by microscopy of simple smear, formalin-ether concentration method, modified acid-fast and modified trichrome staining techniques. Species identification of microsporidia spores was made by transmission electron microscopy (TEM). Cases in which serial fecal examinations were negative were subjected to gastroduodenoscopy and/or colonoscopy. Parasitic infections were found in 51 (56%) AIDS patients with chronic diarrhea and in 18 (17%) non-HIV cases (p < 0.001). Microsporidia and Cryptosporidium parvum were the most common parasites found in HIV infected patients and were also significantly more prevalent than in non-HIV infected cases [29% vs 0% for microsporidia, (p < 0.001), and 25% vs 1% for C. parvum, (p < 0.001)]. Species identification of microsporidia spores in 26 patients using TEM revealed Enterocytozoon bieneusi in 19 cases. This study indicated that microsporidia and C. parvum are important pathogenic causes of chronic diarrhea in AIDS patients in Thailand.

Dedifferentiated leiomyosarcoma of the retroperitoneum, report of a case with immunohistochemical and ultrastructural study.

Dedifferentiated leiomyosarcoma is referred to well-differentiated leiomyosarcoma with presence of pleomorphic malignant fibrous histiocytome - like portion. A case of this tumour of the retoperitoneum was reported in a 75-year-old Thai woman who complained of 2 months of right sided abdominal pain. The 8 cm well-circumscribed mass adherent to the aorta and right ureter was found. Removal of the tumour with cauterization of the remaning fibrous tissue was performed. The patient died 3 months later with recurrence of the tumour and metastasis. Pathological examination revealed well-differentiated leiomosarcoma with abrupt change into malignant fibrous histiocytoma – like tumour. The pleomorphic multinucleated giant cells had immunoreactivities for vimentin, alpha-1-antitrypsin and alpha-1-antichymotrypsin. Very few cells stained with smooth muscle actin. Ultrastructural features were those of undifferentiated cells with rare poorly developed microfilaments with dense aggregate-like area. The findings were similar to one dedifferentiated leiomyosarcoma of the intestinal tract reported by Fakuda et al. The immunohistochemical and ultrastructural study of the dedifferentiated portion reflected malignant fibrous histiocytoma-like features (myofibroblastic) or differentiation toward smooth muscle.

Electron microscopical and immunohistochemical studies of liver tissue in thalassaemic patients: Emphasis on iron and hepatitis B virus.

Fine structure and immunohistochemical studies were investigated in 30 thalassaemic patients. They were diagnosed as having beta thalassemis/haemoglobin E in 19 cases, haemoglobin H disease in 7, and beta thalassemia major in 4. Regardless of the type of haemoglobin, lysosomal haemosiderin was present in various degrees in all cases and some were associated with ferritin molecules. The ferritin molecules were found in both cell sap and lysosome, in four forms: paracrystalline arrangement, hexagonal pattern, finger print fashion and unorganized form. By peroxidase-anti peroxidase (PAP) technique for the detection of hepatitis B surface (HBs) and hepatitis B core (HBc) antigens, HBsAg was found in 1 case of beta thalassemia/Hb E. Ferro-acidophilic bodies (FAB) and ferro-acidophilic degeneration (FAD) were also found. FAB and FAD were probably due to iron hepatotoxicity, because no viral particles were found in this study.