Experimental infections with Fasciola in snails, mice and rabbits.

Experimental infection trails of Lymnaea (cailliaudi) natalensis snails with miracidia of Fasciola hepatica revealed neither cercariae nor larval stages shed. Infection of white mice with metacercariae from field-collected snails proved to be negative for Fasciola eggs and immature juveniles or adults after 84 days post infection. The infection of eight rabbits (Oryctolagus cuniculus) has succeeded; two rabbits were infected, with a very low infection rate. Faeces of rabbits were negative for eggs. The worm burden was one and three worms from 40 fed metacercariae. The obtained fluke measures 23 mm in length by 4 mm in width. The tegument is covered with sharp-ending spines. The uterus contains few eggs. The intrauterine eggs measured 158 microm x 80 microm. According to the morphological characters of these flukes, they belong to F. gigantica.

Application of neural networks to the real-time diagnosis of acute toxoplasmic infection in immunocompetent patients.

Neural networks constitute a relatively new, radically different approach to the interpretation and recognition of subtle diagnostic patterns in multivariate data. In this study the use of neural networks with a single serum sample for rapid real-time recognition of recent toxoplasmic infection was investigated. A neural-network model was implemented on the basis of data obtained by four serological methods--dye test, indirect fluorescence assay, indirect hemagglutination assay, and IgM immunosorbent agglutination assay--and was "trained" to extract features of acute infection by application to an analysis of 65 immunocompetent patients, 10 of whom were in fact acutely infected. The trained model correctly classified all 10 cases of acute infection. On its application to 61 additional infected patients, this method correctly identified seven cases as potentially acute. Our study shows that neural networks can discern diagnostic patterns from variables that individually have limited utility in the diagnosis of acute toxoplasmosis.

Exogenous oxytocin dilates the cervix in ewes.

Cervical anatomy in ewes usually prevents nonsurgical, intrauterine AI and transcervical embryo transfer (ET), which limits their commercial use in sheep. This study was conducted to determine whether oxytocin would dilate the cervix in ewes and permit passage of a stainless steel rod into the uterus. In Exp. 1, at 44 and 52 h after removal of progestogenated pessaries, ewes were injected i.v. with 0 (saline), 200, 400, or 600 USP units of oxytocin. Immediately before and after treatments, stainless steel rods were used to evaluate cervical dilation and determine whether the uterus could be entered. A rod could not be passed through the cervix and into the uterus in any of the saline-treated ewes. All doses of oxytocin given at 44 and 52 h after pessary removal dilated the cervix and permitted easy passage of a rod into the uterus. At both 44 and 52 h, a stainless steel rod was passed into the uterus in 33 of 43 (77%) of the oxytocin-treated ewes. In 93% (40/43) of these ewes, a rod could be passed into the uterus during either the 44-h or during the 52-h attempt. In Exp. 2, on d 9 after pessary removal, ewes were injected i.v. with oxytocin (400 USP units) at 6 or 12 h after i.v. estradiol-17 beta (0, 100, or 200 micrograms). Cervical dilation was evaluated as in Exp. 1. Dose of estradiol x time of oxytocin affected (P less than .01) the proportion of ewes in which a rod could be passed transcervically into the uterus.(ABSTRACT TRUNCATED AT 250 WORDS)