A population growth trend analysis for Neotricula aperta, the snail intermediate host of Schistosoma mekongi, after construction of the Pak-Mun dam.

Background: The Pak-Mun dam is a controversial hydro-power project on the Mun River in Northeast Thailand. The dam is sited in a habitat of the freshwater snail Neotricula aperta, which is the intermediate host for the parasitic blood-fluke Schistosoma mekongi causing Mekong schistosomiasis in humans in Cambodia and Laos. Few data are available which can be used to assess the effects of water resource development on N.

Observations on Neotricula aperta (Gastropoda: Pomatiopsidae) population densities in Thailand and central Laos: implications for the spread of Mekong schistosomiasis.

Background: The snail Neotricula aperta transmits Mekong schistosomiasis in southern Laos and Cambodia, with about 1.5 million people at risk of infection. Plans are under consideration for at least 12 hydroelectric power dams on the lower Mekong river and much controversy surrounds predictions of their environmental impacts.

The phylogeography of Indoplanorbis exustus (Gastropoda: Planorbidae) in Asia.

Background: The freshwater snail Indoplanorbis exustus is found across India, Southeast Asia, central Asia (Afghanistan), Arabia and Africa. Indoplanorbis is of economic importance in that it is responsible for the transmission of several species of the genus Schistosoma which infect cattle and cause reduced livestock productivity. The snail is also of medical importance as a source of cercarial dermatitis among rural workers, particularly in India.

The distribution of Mekong schistosomiasis, past and future: preliminary indications from an analysis of genetic variation in the intermediate host.

Neotricula aperta is the only known intermediate host of Schistosoma mekongi which infects humans in Cambodia and the southern tip of Lao PDR. DNA-sequence data (partial rrnL, i.e.

DNA-sequence variation among Schistosoma mekongi populations and related taxa; phylogeography and the current distribution of Asian schistosomiasis.

Background: Schistosomiasis in humans along the lower Mekong River has proven a persistent public health problem in the region. The causative agent is the parasite Schistosoma mekongi (Trematoda: Digenea). A new transmission focus is reported, as well as the first study of genetic variation among S.

Classification of the parenchymal cells in Fasciola gigantica based on ultrastructure and their expression of fatty acid binding proteins (FABPs).

Parenchymal cells in adult Fasciola gigantica can be classified into three types based on their ultrastructural features and different quantities of fatty acid binding protein (FABP) being stored. Parenchymal cell type 1 (Pc1) has pale cytoplasm consisting largely of a loose network of fine fibers, and it contains few mitochondria but numerous glycogen particles. This cell type may be specialized in the storage and metabolism of glycogen and glucose.

Molecular and immunological characterization of encoding gene and 14-3-3 protein 1 in Fasciola gigantica.

A cDNA encoding Fg14-3-3 protein 1 was cloned by immunoscreening of an adult-stage Fasciola gigantica cDNA library using a rabbit antiserum against tegumental antigens of the parasite. The protein has a deduced amino acid sequence of 252 residues and a calculated molecular weight of 28.7 kDa.

Opisthorchis viverrini: identification of a glycine-tyrosine rich eggshell protein and its potential as a diagnostic tool for human opisthorchiasis.

A cDNA encoding a novel eggshell protein (OvESP) with high-glycine (49.2%) and -tyrosine (27.8%) content was cloned from the human liver fluke Opisthorchis viverrini.

Histopathological alterations in the edible snail, Babylonia areolata (spotted babylon), in acute and subchronic cadmium poisoning.

Histopathological alterations in 6- to 8-month-old juvenile spotted babylon, Babylonia areolata, from acute and subchronic cadmium exposure were studied by light microscopy. The 96-h LC(50) value of cadmium for B. areolata was found to be 3.

Ultrastructural changes in various organs of the fish Puntius gonionotus fed cadmium-enriched cyanobacteria.

The accumulation and toxicity of cadmium in Puntius gonionotus fish that consumed the cyanobacterium Spirulina platensis contaminated with cadmium were studied. Fish were fed cadmium-contaminated cells for 4 weeks, after which cadmium accumulation in various organs was determined. The highest cadmium content was found in the kidney (56.

Occurrence of Perkinsus sp. in undulated surf clams Paphia undulata from the Gulf of Thailand.

The undulated surf clam Paphia undulata supports Thailand's largest shellfishery in the Gulf of Thailand, with landings in 1999 recorded at 70000 t (metric tonnes) yr(-1). We report, for the first time, the prevalence of Perkinsus sp. in clams in the Gulf.

Molecular cloning and analysis of stage and tissue-specific expression of cathepsin B encoding genes from Fasciola gigantica.

The transcriptional products of Fasciola gigantica genes encoding cathepsin B proteases were cloned from adult, newly excysted juvenile (NEJ), and metacercarial stages. The obtained cDNAs were named FG cat-B1, FG cat-B2, and FG cat-B3. The deduced amino acid sequences of the encoded proteases have identities ranging from 64 to 79%.

Schistosomes in the Xe Kong river of Cambodia: the detection of Schistosoma mekongi in a natural population of snails and observations on the intermediate host's distribution.

A natural population of Neotricula aperta (Gastropoda: Pomatiopsidae) in the Xe Kong river of Cambodia was found to be infected with Schistosoma mekongi--apparently the first time this parasite has been found in snails outside the Mekong river. Only 0.14% of the N.

Investigation of Nematopsis spp. oocysts in 7 species of bivalves from Chonburi province, Gulf of Thailand.

This is the first detailed report of Nematopsis spp. in Thai bivalves. A monthly survey was conducted on 7 species of commercial bivalves from Chonburi province, on the eastern seaboard of Thailand, from November 2000 to November 2001 to investigate the prevalence of the apicomplexan parasite Nematopsis Schneider, 1892.

Ultrastructural alterations in the liver and kidney of white sea bass, Lates calcarifer, in acute and subchronic cadmium exposure.

Ultrastructural alterations in the liver and kidney of 3-month-old white sea bass, Latescalcarifer, after cadmium exposure were studied by transmission electron microscopy (TEM). One group of fish was exposed to a cadmium concentration of 10 mg/L (acute) for 96 h in a static system, and another group was exposed to cadmium concentrations of 0.8 and 3 mg/L cadmium (subchronic) for 3 months in a recirculation closed system.

Cadmium biosorption by cells of Spirulina platensis TISTR 8217 immobilized in alginate and silica gel.

The biosorption of cadmium by immobilized Spirulina platensis on alginate gel and silica gel was studied. The maximum biosorption capacities for alginate immobilized cells and silica immobilized cells were 70.92 and 36.

Opisthorchis viverrini and opisthorchiasis: a historical review and future perspective.

Opisthorchiasis is caused by the liver fluke, Opisthorchis viverrini. The fluke afflicts approximately seven million inhabitants in northeastern and northern Thailand. The fluke utilizes, respectively, freshwater snails and cyprinoid fish as its first and second intermediate hosts.

Biochemical and histopathological effects of glyphosate herbicide on Nile tilapia (Oreochromis niloticus).

In Oreochromis niloticus that had been exposed for 3 months to sublethal concentrations (5 and 15 ppm) of the commercial glyphosate herbicide (C(3)H(8)NO(5)P) Roundup, the organs exhibited varying degrees of histopathological change. In the gills filament cell proliferation, lamellar cell hyperplasia, lamellar fusion, epithelial lifting, and aneurysm were observed. In the liver there were vacuolation of hepatocytes and nuclear pyknosis.

Kinetics of basic dye (methylene blue) biosorption by giant duckweed (Spirodela polyrrhiza).

Wastewater containing pigments and/or dyes can cause serious water pollution problems in the form of reduced light penetration and photosynthesis, and the toxicity from heavy metals associated with pigments and/or dyes. Laboratory investigations, of the potential use of dried Spirodela polyrrhiza biomass as an adsorbent for the removal of the basic dye methylene blue from aqueous solution were conducted. A series of experiments were undertaken in an agitated batch adsorber to assess the effect of the system variables, i.

Histopathological alterations of white seabass, Lates calcarifer, in acute and subchronic cadmium exposure.

Histopathological alterations to white seabass, Lates calcarifer aged 3 months in acute and subchronic cadmium exposure were studied by light and scanning electron microscopy. The 96-h LC50 values of cadmium to L. calcarifer was found to be 20.

Biosorption of cadmium and chromium in duckweed Wolffia globosa.

The biosorption of cadmium (Cd) and chromium (Cr) by using dried Wolffia globosa biomass were investigated using batch technique. The effects of concentration and pH solution on the adsorption isotherm were measured by determining the adsorption isotherm at initial metal concentrations from 10 to 400 mg/L and pH 4 to 7 for Cd, and pH 1.5 to 6 for Cr.

Production and characterization of a monoclonal antibody against 28.5 kDa tegument antigen of Fasciola gigantica.

A monoclonal antibody (MoAb) against the 28.5 kDa tegumental antigen of Fasciola gigantica was produced by the hybridoma technique using spleen cells from BALB/c mice immunized with the tegumental extract from adult F. gigantica.