Phylogenetic analysis of the Rhabdocoela (Platyhelminthes) with emphasis on the Neodermata and relatives

Phylogenetic systematic analysis of 24 taxa representing the rhabdocoel platyhelminths, based on a suite of 89 morphological characters, produced two equally parsimonious trees, 181 steps long, with a consistency index (CI) of 0.69 and a rescaled consistency index (RCI) of 0.56, differing only with respect to that portion of the tree containing Umagillidae, Acholadidae, Graffillinae, Pseudograffillinae, Pterastericolidae and Hypoblepharinidae. Our results accommodate all previously proposed sister taxa to the Neodermata in a single clade in which ((Dalyelliidae + Temnocephalida) Typhloplanidae) is the sister group of ((Fecampiidae +  Urastoma ) ( Udonella ((Aspidogastrea + Digenea) (Monogenea (Gyrocotylidea (Amphilinidea + Eucestoda)))))). Bootstrap and jackknife analyses indicate that the groupings of ((Dalyelliidae + Temnocephalida) Typhloplanidae) and of ((Fecampiidae +  Urastoma ) ( Udonella ((Aspidogastrea + Digenea) (Monogenea (Gyrocotylidea (Amphilinidea + Eucestoda)))))) are highly robust, with the latter clade having a CI of 90% and RCI of 82%. Disagreements among previous analyses of these taxa have been due to the influence of missing data for critical characters in key taxa and differences in the taxa analysed, rather than any inherent weakness in the morphological data. Non-phylogenetic systematic approaches to homology assessment and misconceptions regarding phylogenetic systematic methodology are discussed. Recent analyses combining sequence data with a subset of approximately 60% of the morphological characters should be re-assessed using the entire morphological database. Even if Udonella is a monogenean, it is most parsimonious to suggest that the common ancestor of the Neodermata had a vertebrate–arthropod two-host life cycle.     

Estrogen interconversions in the induced cycle in female rhesus monkeys

To determine the extractions and interconversions of estrone and estradiol across and within the uterus, [3H]estradiol and [14C]estrone were infused at a constant rate in six ovariectomized female rhesus (Macaca mulatta) monkeys. Studies were done on Days 9, 14, and 23 of artificial menstrual cycles induced by the timed insertion and removal of Silastic capsules of estradiol and progesterone. Measurements of estrogen radioactivity were made from peripheral arterial blood and uterine venous blood as well as from endometrial biopsy samples. A significant increase occurred in the conversion of estradiol to estrone measured within the uterus on Day 23 compared to Days 9 and 14. The conversion of estrone to estradiol, measured within the uterus, fell progressively from Day 9 to Day 23, but this decrease was not significant. The extractions and interconversions across the uterus, and the overall interconversions of estrone and estradiol were not significantly different on Days 9, 14, or 23 of the cycle. Thus, we have been able to confirm in vivo the increase in the activity of the 17 beta-hydroxysteroid dehydrogenase, the enzyme responsible for estradiol to estrone interconversions, shown earlier by studies done in vitro. However, the increase in 17 beta-hydroxysteroid activity in the uterus is not reflected in the overall interconversions of estrone and estradiol as reflected by measurements in peripheral arterial blood.     

A comparison of cuticular ridge patterns and other morphological characters of Mazamastrongylus odocoilei and Mazamastrongylus pursglovei (Nematoda: Trichostrongyloidea) from white-tailed deer Odocoileus virginianus

The synlophes of Mazamastrongylus odocoilei (Dikmans, 1931) and M. pursglovei (Davidson & Prestwood, 1979) from Odocoileus virginianus were described to provide characteristics for their differentiation from related species in domestic and wild ruminants. The synlophes of M. odocoilei and M. pursglovei were identical. Both had single continuous dorsal, ventral and lateral ridges. Other ridges in the lateral fields in the anterior third of the body angled posteriorly ending adjacent to the single lateral ridge. The ridge system in Mazamastrongylus spp. appears to be unique in lacking the continuous subventral and subdorsal ridges present in all previously studied medium stomach worms from domestic ruminants. Only two characters, spicule length and structure, are known to be useful for differentiating males of M. odocoilei and M. pursglovei, and females cannot be differentiated. Evidence that M. odocoilei and M. pursglovei are separate species include: (1) the two species are frequently found together in the same individual host, but each is also found in the absence of the other; (2) no overlap in spicule size or intergrades in shape have been found although numerous populations have been sampled; and (3) the two species have overlapping, but different, geographical ranges in eastern North America. No differences in the synlophe were found between these two species. The importance of this finding is that the absence of differences in the synlophe is not an unequivocal indicator that nematodes are conspecific.     

New host and geographic records for two protostrongylids in Dall's sheep.

Biodiversity survey and inventory have resulted in new information on the distribution of Protostrongylidae in Dall's sheep (Ovis dalli dalli) from the Northwest Territories (NT, Canada) and from Alaska (AK, USA). In 1998, Parelaphostrongylus odocoilei adults were found for the first time in the skeletal muscles of Dall's sheep in the Mackenzie Mountains (NT). Adult P. odocoilei were associated with petechial and ecchymotic hemorrhages and localized myositis; eggs and larvae in the lungs were associated with diffuse granulomatous pneumonia. Experimental infections of the slugs Deroceras laeve and Deroceras reticulatum with dorsal-spined first-stage larvae assumed to be P. odocoilei, from ground-collected feces from Dall's sheep in the Mackenzie Mountains, yielded third-stage larvae by at least 28 (in D. laeve) and 48 (in D. reticulatum) days post-infection. Third-stage larvae emerged from D. laeve between days 19 and 46 post-infection and emergence occurred both at room temperature and at 10 to 12 C. Protostrongylus stilesi were definitively identified from the lungs of Dall's sheep collected in the Mackenzie Mountains, NT in 1998. Specimens collected from sheep in the Mackenzie Mountains, NT in 1971-72, and the Alaska Range, AK in 1972 were also confirmed as P. stilesi. Lung pathology associated with adults, eggs, and larvae of P. stilesi was similar to that described in bighorn sheep (Ovis canadensis). Concurrent infections with P. odocoilei and P. stilesi in a single host have not been previously reported.     

"Emerging" parasitic infections in arctic ungulates

Important drivers for emergence of infectious disease in wildlifeinclude changes in the environment, shrinking habitats or concentrationof wildlife, and movement of people, animals, pathogens, orvectors. In this paper we present three case-studies of emergingparasitic infections and diseases in ungulates in the Canadiannorth. First we discuss climate warming as an important driverfor the emergence of disease associated with Umingmakstrongyluspallikuukensis, a nematode lungworm of muskoxen. Then we examinehow Protostrongylus stilesi, the sheep lungworm, emerged (orre-emerged) in muskoxen after re-introduction of this host intoits historical range made it sympatric with Dall's sheep. Finally,we consider Teladorsagia boreoarcticus, a newly described andcommon abomasal nematode of muskoxen that is emerging as a disease-causingparasite and may be an important regulator for muskox populationson Banks Island, Northwest Territories. These and other arctichost-parasite systems are exquisitely tuned and constrainedby a harsh and highly seasonal environment. The dynamics ofthese systems will be impacted by climate change and other ecologicaldisruptions. Baseline knowledge of parasite biodiversity andparasite and host ecology, together with predictive models andlong-term monitoring programs, are essential for anticipatingand detecting altered patterns of host range, geographic distribution,and the emergence of parasitic infections and diseases.     

Potassium channel activators based on the benzopyran substructure: synthesis and activity of the C-8 substituent

The synthesis of a series of methoxy bearing 2,2-dimethyl-2H-1-benzopyrans have been achieved for testing as potassium channel activators. The synthesis involves formation of 6-cyano-8-methoxy-2,2-dimethyl-2H-1-benzopyran from vanillin, epoxidation, then ring opening of the epoxide with nitrogen nucleophiles to produce the new benzopyrans. Biological testing showed a dramatic decrease in activity thus revealing an important site of activity in this class of compounds.     

Monoesterification of di-O-isopropylidene and di-O-cyclohexylidene chiro-inositols

Monoesterification of D- or L-chiro-inositols protected as diacetals proceeds in excellent selectivity and yields. The metal-catalyzed, one-step reaction proceeds at room temperature under an air atmosphere and has been developed using a range of examples.