A Simple Method for Screening of Macrofilaricidal Compounds-The Inhibitory Effect of Substances on Phosphatase Activity of Adult Dirofilaria immitis

A simple and reproducible screening method of macrofilaricides is described. The method evaluated in the present paper is based on inhibitory activity of the drugs on acid-phosphatase of Dirofilaria immitis adult worms. The potent inhibitor of acid-phosphates, NaF, inhibited completely the enzymic activity at 1 mM. trimelarsan, suramin and flubendazole inhibited partially the enzymic activity. Their inhibitory activity is comparable to that of Na_2HAsO_4, a specific inhibitor of phosphatase. Diethylcarbamazine and levamisole did not inhibit the phosphatase of D. immitis

Acetylcholinesterase Secretion by Brugia pahangi in vitro

The experiment was designed to demonstrate acetylcholinesterase (AChE) secretion by Brugia pahangi in vitro. Seventy five B. pahangi adult female worms were cultured in 2 ml of Eagle\u27s minimal essential medium (MEM), and the culture fluid was measured for AChE activity by the colorimetric method of Ellman et al. (1961). The enzymic activity increased by the incubation time during the first 24 hours of culture. In an experiment where 25-150 female worms were cultured for 24 hours, higher enzymic activity was detected in the culture fluid where the larger number of worms were cultured. Since AChE activity was not detected in the culture fluid where 100,000 microfilariae were cultured, the results showed that the AChE was secreted by B. pahangi adult female worms. The adult male worms did not have enzyme secreting potential. The secreted AChE was identified as a single protein by disc electrophoresis and possessed the characteristics of the true AChE for its substrate specificity and inhibition by eserine

Simple and Sensitive Enzyme-Linked Immunosorbent Assay for Ivermectin

A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) for the determination of the concentration of ivermectin (IVM) in biological fluids was developed. A conjugate of IVM on bovine serum albumin and poly-L-lysine was used to produce antibodies in rabbits and served as a solid-phase marker for titration of antibodies, respectively. The competitive ELISA was conducted by simultaneously incubating IVM and IVM-biotin conjugate with anti-IVM antiserum over goat anti-rabbit IgG (Fc) and then determining the amount of bound IVM-biotin with avidin-peroxidase conjugate as a tracer. The coefficient of variation for the assay was less than 10% in the range of 0.3?10 ng/ml. The limit of detection was 0.1 ng/ml. The cross-reactivities of anti-IVM antiserum with some anthelmintic drugs were negligible. Using this ELISA, serum levels of IVM were easily determined in Mongolian jirds (Meriones unguiculatus) up to 72 hr following a single oral dose of 500 μg/kg of body weight

The Effect of Praziquantel on Patterns of Schistosoma mansoni Eggshell Hatching Breaks

The break of the eggshell formed by water- and praziquantel (PZQ)-induced hatching of Schistosoma mansoni eggs was observed by scanning electron microscopy. The break most frequently formed on the long axis of the eggshell opposite the spine, and less frequently along spine side, parallel or oblique to the long axis of the lateral side of the egg-shell. An outwardly-curled lip of shell lined the external margins of the hatching orifice. The shell itself was of uniform thickness and fairly smooth. No significant difference was observed in the position breaks between water- and PZQ-hatched eggs. However, PZQ hatching produced smaller hatching orifices and the miracidium frequently failed to escape

Non-Effectiveness of Azadirachta indica (Neem Tree) Leaf Extract against the Larvae of Angiostrongylus cantonensis and Trichinella spiralis.

The effectiveness of the leaf extracts of Azadirachta indica (neem tree) against two nematodes, Angiostrongylus cantonensis and Trichinella spiralis was investigated in mice. Laboratory mice were inoculated with the nematodes followed by the oral administration of the leaf extracts. Two standard drugs, flubendazole and mebendazole were compared with the plant extract in the study. No significant effects of the leaf extract against the nematodes were observed. Thus, although the extract has been shown by other investigators to be animalarial, antibacterial and antifungal, no activity was observed against the two nematodes in this study

Nutritional factors, parasite infection and allergy in rural and suburban Vietnamese school children

Urban areas often have more allergy than rural areas. Dietary patterns and parasite infection have been suggested as possible related factors. This study evaluated the prevalence of allergy in school children in one rural and suburban area of Vietnam where parasite infection is common. A total of 195 children aged 9 to 13 years old completed a self-administered allergy questionnaire and provided blood and stool samples for analysis. Nutritional status, dietary intake and parasite infection were determined in all participants. Allergy was more common in girls (10.7% vs. 7.6%), suburban children (11.8% vs. 6.9%), children with weight-for-age (16.7% vs. 6.0%) and height-for-age (14.8% vs. 4.9%) in the10th to75th percentile compared to lt3rd percentile, and in children without trichuriasis compared to light trichuriasis (12.5%vs. 9.3%), although none of these comparisons were statistically significant. Logistic regression adjusted for sex, age and area of residence revealed no association between allergy and nutritional status, food intake or parasite infection. Intake of riboflavin, however, was negatively associated with allergy (OR=0.00,95% CI:0.00-0.65, p=0.038). In conclusion, we were unable to detect any association between allergy and nutritional status, diet, or parasite infection. However, in a population with high undernutrition and parasite infection, the prevalence of allergy was low and the extremely low intake of riboflavin was associated with a higher risk of allergy

Markedly improved outcomes and acceptable toxicity in adolescents and young adults with acute lymphoblastic leukemia following treatment with a pediatric protocol: a phase II study by the Japan Adult Leukemia Study Group

The superiority of the pediatric protocol for adolescents with acute lymphoblastic leukemia (ALL) has already been demonstrated, however, its efficacy in young adults remains unclear. The ALL202-U protocol was conducted to examine the efficacy and feasibility of a pediatric protocol in adolescents and young adults (AYAs) with BCR\u27ABL-negative ALL. Patients aged 15\u2724 years (n = 139) were treated with the same protocol used for pediatric B-ALL. The primary objective of this study was to assess the disease-free survival (DFS) rate and its secondary aims were to assess toxicity, the complete remission (CR) rate and the overall survival (OS) rate. The CR rate was 94%. The 5-year DFS and OS rates were 67% (95% confidence interval (CI) 58\u2775%) and 73% (95% CI 64\u2780%), respectively. Severe adverse events were observed at a frequency that was similar to or lower than that in children treated with the same protocol. Only insufficient maintenance therapy significantly worsened the DFS (hazard ratio 5.60, Po0.001).These results indicate that this protocol may be a feasible and highly effective treatment for AYA with BCR\u27ABL-negative ALL

Comparison of the Methods Available for Purification of Brugia pahangi Microfilariae in the Peritoneal Lavage of Jirds (Meriones unguiculatus)

The pros and cons of the methods available for the separation and purification of Brugia pahangi microfilariae in jirds peritoneal lavage was studied. The methods examined in the present study were agar-enclosing method described by Nogami et al. (1982) and Sephadex PD-10 column method described by Rathaur et al. (1987). Both methods allowed us to recover live microfilariae alone. The purity of microfilarial suspension was satisfactory in both methods; no peritoneal cells, dead microfilariae nor ovum. The PD-10 column method was superior in the percent recovery of microfilariae; 77-89% of microfilariae loaded were recovered by passage on PD-10 column, while 53-74% of microfilariae embedded were recovered by agar-enclosing method. Agar pads used for separation of microfilariae were fragile and frequently disrupted, resulting in the contamination of peritoneal cells in microfilarial suspension. In addition, the PD-10 method was superior in less time consuming and less laborious procedure. PD-10 column can be used repeatedly. Thus the PD-10 column method is, at present, the best available one for separation and purification of microfilariae from peritoneal lavage