Description of Paratetrahymena parawassi n. sp. using Morphological and Molecular Evidence and a Phylogenetic Analysis of Paratetrahymena and Other Taxonomically Ambiguous Genera in the Order Loxocephalida (Ciliophora,Oligohymenophorea)

ABSTRACT. The marine scuticociliate Paratetrahymena parawassi n. sp. is described on the basis of morphology, especially infraciliature, and the sequence of its small subunit (SSU) rRNA gene to become the second known member of its genus. Paratetrahymena and other ciliates in the order Loxocephalida possess a mixture of morphological and morphogenetic features characteristic of the subclasses Hymenostomatia and Scuticociliatia. Accordingly, we used SSU rRNA sequences to analyze the phylogeny of Paratetrahymena and three other loxocephalid genera. Paratetrahymena and Cardiostomatella vermiformis formed a moderately well‐supported clade that diverged at a deep level from all other scuticociliates, supporting separation of loxocephalids from other scuticociliates as a suprafamilial taxon. Sathrophilus holtae was a sister taxon to Paratetrahymena and Cardiostomatella in a poorly supported, unresolved relationship; nevertheless, association of all three genera into a single clade was supported by an approximately unbiased (AU) test. Any association of these genera singly or as a group with the Hymenostomatia was rejected decisively by AU tests and by a complete absence in the loxocephalids of the unique nucleotide identities that distinguish hymenostomes. Therefore, the morphological and morphogenetic similarities of loxocephalids to hymenostomes may be plesiomorphies, and the conflicting mix of scuticociliate and hymenostome characteristics seen in loxocephalids may result from differing rates of character evolution. Dexiotrichides pangi and Urocentrum, which is currently classified as a peniculid, formed a small clade that associated with hymenostomes and peritrichs. Monophyly of the Loxocephalida with Dexiotrichides and/or Urocentrum included was not rejected by AU; however, inclusion of Urocentrum in the Peniculia was rejected by AU tests. A hypothesis is offered to explain the lack of resolution of loxocephalid ciliates and Urocentrum in phylogenetic trees, namely that their phylogenetic positions are influenced by a combination of heterogeneous data and long‐branch attraction caused by poor representation of taxa in analyses. The well‐known genus Cyclidium, a member of the order Pleuronematida, was revealed to be polyphyletic as a byproduct of our analyses of loxocephalids. In particular, Cyclidium porcatum appears to fall outside the clade containing typical members of the subclass Scuticociliatia and thus invites investigation as a possible member of the order Loxocephalida.     

Vector competence of Coquillettidia linealis (Skuse) (Diptera: Culicidae) for Ross River and Barmah Forest viruses

Abstract Coquillettidia linealis is a severe pest on some of the Moreton Bay islands in Queensland, Australia, but little is known of its breeding habitats and biology. Because of its high abundance and its association with Ross River (RR) and Barmah Forest (BF) viruses by field isolation, its vector competence was evaluated in the laboratory by feeding dilutions of both viruses in blood. For RR, Cq. linealis was of comparable efficiency to Ochlerotatus vigilax (Skuse), recognised as being a major vector. Results were as follows for Cq. linealis and Oc. vigilax , respectively: dose to infect 50%, 10^2.2 and <10^1.7 CCID₅₀/mosquito; 88% and 90% disseminated infection at 4 days postinfection; transmission at 4 days with rates of 68−92% and 25−60%. For BF dose to infect 50%, 10^2.7 and 10^2.0; disseminated infection rates on first transmission day (day 6), 40% and 70%; transmission rates of 8−16% and 0−10%. As a capillary-tube method was used rather than suckling mice to demonstrate transmission, transmission rates may be underestimates. This, the first study of the vector competence of Cq. linealis in Australia, demonstrates that this species deserves control on the southern Moreton Bay islands.     

Prevalence of non-strongyle gastrointestinal parasites of horses in Riyadh region of Saudi Arabia

This study aimed to provide recent data on the occurrence of non-strongyle intestinal parasite infestation in horses in the Riyadh region of Saudi Arabia as a basis for developing parasite control strategies. We conducted necropsy for 45 horses from September 2006 to November 2007 in the Riyadh region, Saudi Arabia. 39 out of 45 horses were infected with intestinal parasites with an infestation rate of 86.6%. Infestations with seven nematode species and two species of Gasterophilus larva were found. The most prevalent parasites were Strongyloides westeri (64.4%) and Parascaris equorum (28.8%) followed by Habronema muscae (22.2%). Trichostrongylus axei and Oxyuris equi were less common at (11.1%) and (8.8%), respectively. Habronema megastoma and Setaria equine were found in two horses only (4.4%). Gasterophilus intestinalis larvae were recovered from 39 horses (86.6%) and Gasterophilus nasalis larvae were found in 17 horses (37.7%). Season had a significant effect on the prevalence of P. equorum and G. nasalis, while age of horses had a significant effect only on the prevalence of P. equorum. The husbandry in Saudi Arabia appears to be conductive to parasites transmitted in stables or by insects rather than in pasture.     

Strength and power profiles of the lower and upper extremities in master throwers at different ages

Thirty-two master athletes (shot put, discus, and hammer throw) were divided into 4 groups according to their age (T40 [40 years of age], 50 [50 years of age], 60 [60 years of age], and 75 [75 years of age]). Twenty-eight age-matched men served as controls (C40 [40 years of age], 50 [50 years of age], 60 [60 years of age], and 75 [75 years of age]). The subjects were tested for maximal isometric strength of the lower and upper extremities. Power was measured by performing jump squats and bench press in the Smith machine with the load of 60% of 1 repetition maximum. Electromyographic (EMG) activity was recorded from 6 different muscles. The muscle thickness of vastus lateralis and intermedius (VL+VI) and triceps brachii (TB) was measured by ultrasound. Maximal strength differed (p < 0.05- 0.001) in all testing actions between T40 and T60 and T40 and T75 as well as between T and C groups. Both VL+VI and TB thickness in T40 was greater (p < 0.05-0.01) than in T60 and T75 and in T was larger than in C groups. Average force during the first 500 milliseconds (ms) was higher (p < 0.05-0.001) in T40 compared to T50, T60, and T75 in bilateral leg extension, biceps curl, and especially in unilateral knee flexion. T40 produced higher power than the other groups (p < 0.05-0.001). The relative agonist EMG activation (VL) in leg extension during the first 100 ms compared to maximum activation was lower (p < 0.05) in T50, T60, and T75, but not in T40. The present data indicate that maximal strength and muscle thickness as well as explosive strength and power characteristics decline with aging also in master athletes who carry out strength training and throwing exercises actively over several decades. Nevertheless, in master athletes, maximal strength and muscle mass as well as explosive force production of the upper and lower extremities seem to be at remarkably higher levels than those recorded for age-matched control men.     

KPNA7, a nuclear transport receptor,promotes malignant properties of pancreatic cancer cells in vitro

Pancreatic cancer is an aggressive malignancy and one of the leading causes of cancer deaths. The high mortality rate is mostly due to the lack of appropriate tools for early detection of the disease and a shortage of effective therapies. We have previously shown that karyopherin alpha 7 (KPNA7), the newest member of the alpha karyopherin family of nuclear import receptors, is frequently amplified and overexpressed in pancreatic cancer. Here, we report that KPNA7 expression is absent in practically all normal human adult tissues but elevated in several pancreatic cancer cell lines. Inhibition of KPNA7 expression in AsPC-1 and Hs700T pancreatic cancer cells led to a reduction in cell growth and decreased anchorage independent growth, as well as increased autophagy. The cell growth effects were accompanied by an induction of the cell cycle regulator p21 and a G1 arrest of the cell cycle. Interestingly, the p21 induction was caused by increased mRNA synthesis and not defective nuclear transport. These data strongly demonstrate that KPNA7 silencing inhibits the malignant properties of pancreatic cancer cells in vitro and thereby provide the first evidence on the functional role for KPNA7 in human cancer.