The BALB/C mouse infected with Brugia pahangi has been evaluated as a model for the selection of filaricidal compounds with activity against immature worms. Mice were infected by the intraperitoneal inoculation of 50 infective larvae and candidate compounds were administered by the intraperitoneal (i.p.), subcutaneous or oral route once daily from day 4 to day 8 post infection. Animals were examined on days 29 to 32 post infection. Variation in the larval recoveries from undrugged mice within and between experimental groups limited the value of drug assessments based upon percentage worm recoveries. The infection rate of undrugged mice was 85% over-all, range 60 to 100%. Using the infection rate of drugged v. undrugged animals as the criterion of activity the test has been evaluated with a series of standard nematicidal compounds.. Lcvamisolc and the benzimidazole carbamatcs, mebendazole, flubendazole and fenbendazole given i.p. at lOmg/kg daily were active in this screen whilst DEC, DEC-N-oxidc, ivcrmcctin, amoscanatc, mctrifonatc and suramin were inactive at the dosages tested. No retardation of growth or morphological abnormalities were observed in worms from the drugged mice.

A number of in vitro culture systems were tested for their ability to support the development of Dirofilaria immitis infective larvae to the fourth larval stage. In cultures of medium ML-15 containing a feeder layer of Dog Sarcoma (DS) cells larvae successfully moulted and showed a small but significant increase in length. Ultrastructural observations demonstrated that the fourth-stage cuticle was synthesized in vitro and in some larvae was fully formed by 60 hours of culture. The hypodermis of moulting larvae contained numerous multi-vesicular bodies. It is concluded that the moult in vitro is a true moult and not an atypical response of the larvae to the conditions of culture.

The possibility of coproantigen detection in the diagnosis of strongyloidiasis was investigated in rats experimentally infected with Strongyloides ratti. A capture ELISA was developed using affinity-purified polyclonal antibodies raised in rabbits against adult and filariform larval somatic antigens. The first detection of coproantigen coincided with patency and the coproantigen level remained elevated even when the parasite count was low. Following challenge infection, when examination of stool for larvae or ova was negative, coproantigen was detected by anti-adult somatic capture ELISA. Despite the use of antisera raised against crude worm extracts, the test was specific showing only low cross-reactivity with Necator americanus and Syphacia muris.

The existence of primary branchiogenic carcinoma – that is, carcinoma arising in a pre-existing branchial cleft cyst (a benign developmental cyst) – has in recent decades been the subject of increasing scepticism. Recognition of the propensity of a variety of head and neck sites – including in particular the tonsil – to give rise to cervical metastases while the primary tumours themselves remain undetected has given rise to the idea that virtually all cystic carcinomas of the neck represent metastatic deposits, whether or not their primary sites are found. A diagnosis of primary branchiogenic carcinoma should be viewed with extreme scepticism, and every effort should be made (e.g. imaging, panendoscopy, elective tonsillectomy) to exclude the existence of a primary site elsewhere, before considering a diagnosis of primary branchiogenic carcinoma.

Previous studies have shown that the secreted phosphorylcholine-containing glycoprotein of filarial nematodes, ES-62, is only present in the post-infective life-cycle stages, but that the mRNA is transcribed throughout the worm's life-cycle. The aim of this current study was to investigate whether the presence or absence of protein expression simply reflects differences in mRNA abundance. To this end, we investigated the relative abundance of ES-62 using TaqMan real time RT-PCR, in different life-cycle stages of 2 model filarial nematode parasites, Acanthocheilonema viteae and Brugia pahangi. For B. pahangi, microfilariae, infective larvae and adult worms were each found to have approximately similar levels of ES-62 mRNA. However, the corresponding stages of A. viteae differed greatly from each other with a pattern of increased mRNA production with maturation. As a rule A. viteae had higher levels of ES-62 mRNA than B. pahangi, and this was particularly noticeable in the adult stage where the difference was approximately 3500-fold higher. However, this significant difference in mRNA abundance was not reflected in the quantity of ES-62 protein secreted by the adult worms of each species, as A. viteae only secreted ~3 times as much ES-62 as B. pahangi. Thus, overall, the results obtained from this study indicate that ES-62 protein production does not solely reflect mRNA levels, and also suggest that the 2 nematodes may employ different mechanisms for regulating protein production.

ES62, an immunomodulatory phosphorylcholine-containing glycoprotein secreted by the rodent filarial nematode Acanthocheilonema viteae, has previously been shown to be produced by L4 larvae and adult worms only. However, homologous sequences to ES62 have recently been found in L1 and L3 cDNA libraries of certain human filarial nematodes. Therefore, the various stages of A. viteae were re-examined and it was again found that only the post-L3 stages secreted ES62. Synthesis but not secretion by earlier stages was ruled out by examination of the protein content of whole worm extracts and by immunoelectron microscopy. However, examination by PCR of the mRNA for ES62 revealed that it was found in the L1 and L3 larvae. This may explain why homologous sequences to ES62 have been found in Brugia malayi and Onchocerca volvulus larval cDNA libraries. It also suggests that filarial nematodes, in general, may secrete ES62. To obtain evidence for this, we investigated production by Brugia pahangi, a close relation of B. malayi. We found that ES62 was indeed secreted but, as with A. viteae, only by the post-L3 stages, although again the mRNA for ES62 could be detected in the earlier stages. Overall our results suggest that production of ES62 is not species specific, that it is indeed stage specific, and that this may be due to post-transcriptional control of expression.

A cDNA library constructed from 3 day post-infective L3 of the filarial nematode Brugia pahangi was screened by differential hybridization with cDNA probes prepared from different life-cycle stages. Five cDNA clones hybridizing selectively to the mosquito-derived L3 probe were isolated and characterized. Northern blot analysis of 4 of the clones confirmed that each was most highly expressed in the mosquito-derived L3. The expression of each mRNAduring parasite development in the mosquito vector was investigated using RT–PCR, and all were shown to be abundant in the immature L3. Four of the 5 cDNAs cloned coded for structural proteins: 2 cuticular collagens, and the muscle proteins tropomyosin and troponin. Further studies on troponin using an antiserum raised to the recombinant protein demonstrated that the protein, unlike the mRNA, was present in all life-cycle stages examined, while immunogold labelling demonstrated that it was localized to the muscle blocks.

The mechanism of linkage of phosphorylcholine (PC) to excretory–secretory products (ES) of adult Brugia pahangi has been investigated. Biosynthetic radio-isotope labelling of ES with [3H]choline followed by SDS–PAGE/fluorography revealed a smear of molecular weight approximately 40–100 kDa which loses its radiolabel following exposure to N-glycosidase F, but not mild alkali. PC is thus attached to this smear of molecules via N-type glycans, a mechanism of linkage previously observed with respect to PC–ES of Acanthocheilonema viteae. Western blotting analysis of non-radiolabelled ES demonstrated the existence of additional PC–ES which were insensitive to N-glycosidase F, but not to alkali. This second group of molecules is therefore likely to contain PC linked to O-glycans. Filarial nematodes may thus utilize 2 classes of glycan for attachment of PC. Examination of B. pahangi and A. viteae whole worm extracts by Western blotting indicated that their PC content could not be cleaved by N-glycosidase F and hence the use of N-type glycans may be restricted to a subset of ES products. The implications of these findings with respect to developing inhibitors of PC attachment for use as anti-filarial drugs are discussed.

We report the observation of T Tau by visible speckle interferometry at the CFHT. The observations were carried out at two wavelengths simultaneously. Each image was split into two, allowing improved data processing. The 4-channel photon-counting detector CP40 was used. We have discovered that 30% of the total energy at Hα is emitted by an extended elliptical component, with a FWHM of 70 marcsec. In the neighbouring continuum, T Tau is not resolved by the 3.60 m CFHT. We briefly discuss the astrophysical consequences of this new result.

This paper summarizes a series of experiments to determine the strontium leachability of cement-based sludge-slurry hydrofracture grouts.

The hydrofracture process has been used at ORNL since 1966 for the routine disposal of intermediate-level waste (ILW) solutions. In this process, cement and other additives are mixed with a waste stream to form grout, which is then injected into a shale bed at a pressure sufficient to cause fracturing along the horizontal bedding planes. This injected grout soon hardens, fixing the radionuclides between layers of the massive Conasauga shale formation.

Modified IAEA dynamic leach tests on hydrofracture grout specimens showed improved leach resistance (by a factor of 3 to 5) as the curing time increased from 28 d to 91 d. A weak trend toward lower leachability with increased amounts of dry solids was observed.

The moving boundary-plus-diffusion leach model fits the dynamic leach data successfully in most cases. An apparent diffusion coefficient of 5 × 10−12 cm2/s and a moving boundary coefficent of 1 × 10−7 s−1 were obtained when one of the best grout compositions was leached in distilled water.

Concretes formed under elevated temperatures and pressures (FUETAP concretes) are effective hosts for transuranic (TRU) and high-level defense and commercial wastes.

Tailored cement formulations developed at Oak Ridge National Laboratory (ORNL) use Portland cement, fly ash, sand, and clay additives. These FUETAP concretes are cured under mild autoclave conditions, then the unbound water is removed.

This paper summarizes the FUETAP development program. These continuous studies address the major questions concerning the performance of radioactive waste forms.