Pathogenesis ; Swine ; Papua New Guinea

Platelet-activation factor (PAF), one of the potent proinflammatory mediators, is produced from a large range of cells, including polymorphonuclear neutrophils, monocytes, and natural killer cells. To study the role of PAF in the pathogenesis of silicosis, we determined the PAF in silicotic patients and in healthy persons. The results showed that the concentration of PAF in the plasma of silicotic patients was significantly higher than that of healthy persons. Our in vitro experimental results showed that the total numbers of fibroblasts were markedly raised with added PAF from 0 to 1 μ g/ml. Adding 1 μ g/ml PAF significantly increased the total numbers of fibroblasts after culture for 48, 72, 96 hrs. Therefore, we suggest that PAF be possibly involved in the pathogenesis of silicosis. However, the mechanism remains to be further elucidated.
Platelet Activating Factor ; g <3> ; Pathogenesis ; /mL ; Effective

Allergic rhinitis is the single most common chronic allergic disease affecting an estimated four million people in Malaysia. House dust mites, grass pollens and fungal spores play has been identified to play a major role in the pathogenesis of allergic rhinitis. However, sensitization to pollen and spores in Malaysia is not well documented. On the basis of the results of an aerobiological survey of the common mold spores and pollens in the Klang Valley, twelve local extracts of molds and two local extracts of grass pollens were prepared by the Institute for Medical Research for this study. The study evaluated the prevalence of skin prick test (SPT) reactivity to the extracts of those airborne molds and pollens in allergic rhinitis patients in the Klang Valley. A total of 85 allergic rhinitis patients were recruited. All molds and grass pollens extracts tested, elicited positive response to SPT. Among the molds extracts, Fusarium was observed to have the highest prevalence of SPT reactivity (23.5%), followed by Aspergillus flavum (21.2%), Dreselera orysae (18.8%), Alternaria sp (17.6%), Curvularis eragrostidis (17.6%), Penicillium oxa (16.5%), Pestolotriopsis gtuepini (16.5%), Rhizopphus arrhi (16.5%), Aspergilluls nigus (15.3%). Penicillium choy (12.9%), Aspergillus fumigatus (11.8%), and Cladosporium sp (4.7%). In the grass pollen, the SPT reactivity to Ischaemum and Enilia is 14.1% and 5.9% respectively. However, the prevalence of SPT reactivity was not influenced by the age, sex, ethnicity, symptomatology and concurrent allergic condition. We have documented the prevalence of skin prick test reactivity to common molds and grass pollens in the Klang valley, which is comparable to the neighboring countries. Its prevalence in our allergic rhinitis patients suggests that it has a role in pathogenesis of allergic diseases. A larger representative sample involving multi-centric centers in Malaysia should be encouraged in the near future.
Mold, NOS ; Allergic rhinitis, NOS ; Prevalence aspects ; Malaysia ; Pathogenesis

This special issue is devoted to a review of the current state of knowledge of clonorchiasis. Sections deal with: the biology of Clonorchis sinensis; geographical distribution, with particular regard to Korea; epidemiology; pathogenesis; clinical features; diagnosis; prevention and control; chemotherapy.
review ; parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; epidemiology ; pathogenesis ; liver ; diagnosis ; chemotherapy ; praziquantel ; control ; hetol ; di

In order to evaluate the pathogenicity of Korean strains of Trichomonas vaginalis, an experimental inoculation of T. vaginalis into mouse peritoneal cavity was performed. Fifteen strains of T. vaginalis were selected from 53 infected cases and were cultured axenically in Roiron-Rattner medium at 37C for 48 hours. Each strain, at the dose of 0.5 ml of 1x10(6)/ml trichomonads, was inoculated intraperitoneally to a group of 10 mice, respectively. A total of 15 groups, consisted of 150 mice, were sacrificed on the 8th day of inoculation, and then they were thoroughly examined for the detection of the lesion. The results obtained in present study were summarized as follows: Prior to inoculation, the positive rates in 2 kinds of media cultivating T. vaginalis were compared. In Johnson's CPLM medium, 65 percent of positive rate was obtained, and 94.2 percent of positive rate, the better result, was shown in the culture of Roiron-Rattner medium. Overall death rate of 150 inoculated mice was 7.3 percent (range 0-40 percent), and 7 strains (46.7 percent) out of 15 inoculated strains were proved as fatal strain. The intraperitoneal lesions produced by the inoculation of T. vaginalis were observed in the liver (20 percent), intestinal wall and mesentery (14 percent), peritoneal wall (9.3 percent), wall of the stomach (6.0 percent), and the spleen (5.3 percent) of 150 inoculated mice. Occasionally, the lesions were also found in the pancreas and wall of the urinary bladder. In 11.3 percent of inoculated mice, purulent ascites with living trichomonads could be seen. Thirteen strains (86.7 percent) out of the 15 inoculated strains produced the T. vaginalis-associated pathological lesions. On the histopathological investigation of those lesions, intraperitoneal inoculation was characterzed by a necrotizing granulomatous inflammation, i.e., acutely necrotizing process with areas of encircling granuloma formation. Numerous free lying trichomonads were seen along the expanding margin of the lesion. Where there were free trichomonads, the reaction was usually of necrotizing. And these organisms directly eroded the vascular wall and often provoked thrombosis. From the above findings, it is considered that the Korean strains of T. vaginalis are highly pathogenic.
parasitology-protozoa-Trichomonas vaginalis ; pathogenesis ; mouse ; granuloma ; necrosis ; Roiron-Rattner medium ; Johnson's CPLM medium

The traditional Japanese diet with its high intake of fruits and vegetables that are rich in antioxidants is believed to effectively ward off cardiovascular disease. Oxidative stress, related to reactive oxygen and nitrogen species produced by aerobic organisms, is responsible for the pathogenesis of most chronic diseases. Oxidative low density lipoprotein (LDL) is thought to play a key role in the pathogenesis of early atherosclerosis. There has been increasing interest in antioxidant substances derived from edible plants. It has been suggested that the measurement of LDL antioxidant activity is physiopathologically more important and informative for screening antioxidant activity to prevent atherosclerosis than other methods. We assessed by LDL oxidation assay the antioxidant characteristics of various edible plants from rural areas. The mulberry (Morus alba L.) leaf showed comparatively high antioxidant activity. We identified the antioxidant compounds and investigated compound levels in the mulberry leaf and found the antioxidant activity of mulberry leaves to be mainly attributable to quercetin 3-(6-malonylglucoside) (Q3MG). Dietary consumption of mulberry leaves and/or Q3MG may enhance resistance to oxidative modification of LDL and attenuated atherosclerotic lesion development. However, the outcome of intervention trials suggested that a single antioxidant had little effect on the risk of developing cardiovascular disease. The synergic effect of certain combinations may determine outcome. We need to widen our understanding of the synergic effect of diets and nutrient-gene interactions related to nutrient/disease risk.
Antioxidants ; seconds ; Low density lipoprotein cholesterol measurement ; Pathogenesis ; Oxidative Dietary Supplements

The pathogenicity of free-living amoeba, Naegleria fowleri, is influenced according to the strain, cultural condition and host (Culbertson et al., 1968; Carter, 1970; Wong et al., 1975). Phillips (1973) demonstrated that Entamoeba histolytica became avirulent after more than 2 year maintenance in axenic culture in vitro. This study was carried out to compare the difference in pathogenicity between two strains of N. fowleri, one of a prolonged maintenance in axenic medium and the other one obtained by serial brain passage in mice. The 0 strain was that N. fowleri had cultivated axenically more than 7 years in CGVS medium. The 2-1 strain was obtained from the brain of mouse inoculated intranasally with a strain, which was from the mouse brain infected with 0 strain, and cultured for 15 weeks until the beginning of this experiment. White male mice weighing 18-22 g were used. Mice were anesthetized by an intraperitoneal injection of about 1 mg secobarbital, and inoculated intranasally with 10 x 10(4) live N. fowleri trophozoites in a 5 microliter cell suspension. Sluggish behaviour, nervousness, rotation and leg paralysis were developed earlier and more frequently in the 2-1 experimental group than the control 0 group. Pathological changes such as inflammatory and necrotic lesion were observed in the olfactory and anterior portion of brain, and these changes were more extensive in the 2-1 group. The edematous and inflammatory changes in lung were demonstrated in mice died after 13th day post-inoculation. The experimental mice of 2-1 group began to die suddenly from 7th day post-inoculation, and the survival time in 2-1 group mice was shorter than 0 group mice. The typical primary amoebic meningoencephalitis was developed in the mice inoculated intranasally with N. fowleri. The prolonged maintenance of N. fowleri amoebae in axenic CGVS medium was observed to have lost their original pathogenicity for mice, but their pathogenicity was restored by serial brain passage in mice.
parasitology-protozoa ; Naegleria fowleri ; pathogenesis ; mouse ; brain ; primary amoebic meningoencephalitis ; secobarbital ; CGVS medium ; pathology ; nervousness ; leg paralysis