811 resultados para Explorers, Australian
Resumo:
To define the location of potential oncogenes and tumor suppressor genes in ocular melanoma we carried out comparative genomic hybridization (CGH) analysis on a population-based series of 25 formalin-fixed, paraffin-embedded primary tumors comprising 17 choroidal, 2 ciliary body, 4 iris, and 2 conjunctival melanomas. Twelve (48%) of the 25 melanomas showed no chromosomal changes and 13 (52%) had at least one chromosomal gain or loss. The mean number of CGH changes in all tumors was 3.3, with similar mean numbers of chromosomal gains (1.5) and losses (1.8). The highest number of chromosomal changes (i.e., nine) occurred in a conjunctival melanoma and included four changes not observed in tumors at any other ocular site (gains in 22q and 11p and losses in 6p and 17p). The most frequent gains in all primary ocular melanomas were on chromosome arm 8q (69%), 6p (31%) and 8p (23%) and the most frequent losses were on 6q (38%), 10q (23%), and 16q (23%). The most common pairing was gain in 8p and gain in 8q, implying a whole chromosome copy number increase; gains in 8p occurred only in conjunction with gains in 8q. The smallest regions of copy number alteration were mapped to gain of 8q21 and loss of 6q21, 10q21, and 16q22. Sublocalization of these chromosomal changes to single-band resolution should accelerate the identification of genes involved in the genesis of ocular melanoma.
Resumo:
Fraser details the violence experienced by white Pentecostal married women in Australia, a violence that is legitimated by and internalized through religious discourse. She focuses on the mechanisms of the androcentric silencing of women by male Pentecostal leaders and doctrine, and on women's collaboration with them from a feminist theoethical perspective.
Resumo:
A new macropodiniid ciliate genus, Megavestibulum, is described which is endocommensal in the stomach of macropodid marsupials. Two new species, M. morganorum and M. kuhri, are described from Macropus dorsalis and Wallabia, bicolor respectively. Megavestibulum is holotrichous, the somatic ciliation arranged into meridional, curving kineties between broad ridges. The interkinetal ridges are lined apically by thick-walled vacuoles similar to those lining the longitudinal grooves of Macropodinium. The conical vestibulum is apical and very large, occupying up to 1/3 of the cell volume. The vestibular lip appears closable and has a cleft which may allow distention of the vestibullum to ingest large food items. The vestibular ultrastructure is similar to that of Macropodinium including the presence of vestibular vacuoles and the hemispherical differentiation of the distribution of small nematodesmata. Many specimens contained ingested whole ciliates of the genera Amylovorax and Polycosta. The structure of the vestibulum suggests that Megavestibulum is adapted for life as an active predator of other stomach ciliates as well as sweeping in small particulates. The morphology of Megavestibulum suggests that it represents the plesiomorphic body plan within the family Macropodiniidae.
Resumo:
A new genus of amylovoracid ciliates, Bandia gen.nov., is described. They are endosymbiotic/endocommensal in the stomachs of macropodid marsupials. Six new species, B. beveridgei, B. equimontanensis, B. tammar, B. deveneyi, B. cribbi and B. smalesae, are described from Setonix brachyurus, Petrogale assimilis, Macropus eugenii, M. robustus, M. parryi and M. agilis respectively. The gross morphology of Bandia is similar to that of Bitricha, with holotrichous somatic ciliation in two fields, longitudinal dorsal and oblique ventral. The somatic kineties are arranged in groups between non-ciliated. major interkinetal ridges; the groups of kineties thus give the cell a banded appearance. Several species are bimorphic, one form holotrichous and the other with a glabrous right body groove which appears to be derived from an ingrowth of one of the major interkinetal ridges. The groove may function in attachment either in sequestration or conjugation. The ultrastructure of the somatic kineties and the oral structures is similar to that of Amylovorax. Bandia also has unique ultrastructural features associated with the major interkinetal ridges, right body groove and a karyophore. Morphological evolution within the Amylovoracidae may have proceeded from simple forms such as Amylovorax via a process of cellular torsion and/or oral migration to forms similar to Bitricha and by further torsion and cellular elaboration to Bandia.
Resumo:
A new family, Polycostidae, containing one new genus, Polycosta, of ciliates endwocommensal in the stomachs of macropodid marsupials is described. Four new species, A roundi, P. turniae, A sebastopolensis and P. parma are described from Wallabia bicolor, Macropus dorsalis, Petrogale herberti and M. eugenii, respectively. Polycosta is holotrichous with slightly spiral meridional kineties arranged between broad interkinetal ridges. The ultrastructure of one representative species displays the knitted together pattern of postciliary microtubules and kinetodesmata of somatic kinetids common in trichostomes and the interkinetal ridges are dominated by layers of dark bodies but lack ectoplasmic hydrogenosomes. The vestibulum is conical and its aperture appears capable of closing tightly in most species; vesibular kineties are continuations of the right somatic kineties into the vestibulum. There is a prominent phago-plasm delimited internally by a basket of nematodesmata derived from electron dense plates at the bases of kinetosomes the anterior somatic and vestibular kineties. There is a prominent cytoproct which is situated within an invagination of the cell in some species. Polycosta is similar to Amylovorax in terms of gross morphology, somatic ciliature and cortical ultrastructure. The vestibular ultrastructure, however, is more similar to that of Macropodinium. The affinities of the group are thus not clear and this unique combination of characters supports the erection of a new family.
Resumo:
Trichostome ciliates are associated with many different lineages of herbivorous mammals but there are few comparative studies of these associations in each lineage of herbivores. Here the occurrence of the ciliate fauna in a range of herbivorous marsupials (diprotodonts) is investigated and compared with that of ruminants. A total of 371 potential host animals, representing 33 species and 7 families, were examined for the presence of ciliates. The prevalence of endocommensal ciliates within individual host species varied between 0 and 100%. Of the different dietary groups of marsupials examined, only foregut (macropodids) and hindgut (vombatids) fermentative herbivores were found to harbour ciliates; carnivorous (dasyurids), omnivorous (peramelids) and midgut fermenting herbivores (phalangeroids) all lacked ciliates. The majority of ciliate species were oioxenic, several occurred in closely related hosts and some were able to colonise unnatural hosts in captive populations. Ciliate prevalences were found to vary at all levels: between hosts of different species, between conspecific hosts collected at different localities or seasons and between conspecific hosts at one collecting locality. The faunal composition of the 2 marsupial families which harboured ciliates differed greatly: the vombatid fauna was composed exclusively of amylovoracids whereas the macropodids harboured amylovoracids, polycostids and macropodiniids. In comparison to the ciliate fauna of ruminants, the fauna of macropodids is both depauperate and much more host specific. Low species richness in each host may be due to the large numbers of stomach nematodes in macropodids which compete with and may prey upon the ciliates within the stomach. The high levels of host specificity are probably due to different patterns of ciliate transmission in macropodids as they do not ruminate, eructate or feed indiscriminantly on pasture contaminated with saliva containing ciliates.
Resumo:
Objectives: The aim was to determine whether methadone maintenance treatment reduced heroin use, syringe sharing and HIV or hepatitis C incidence among prisoners. Methods: All eligible prisoners seeking drug treatment were randomised to methadone or a waitlist control group from 1997 to 1998 and followed up after 4 months. Heroin use was measured by hair analysis and self report; drugs used and injected and syringe sharing were measured by self report. Hepatitis C and HIV incidence was measured by serology. Results: Of 593 eligible prisoners, 382 (64%) were randomised to MMT (n = 191) or control (n = 191). 129 treated and 124 control subjects were followed up at 5 months. Heroin use was significantly lower among treated than control subjects at follow up. Treated subjects reported lower levels of drug injection and syringe sharing at follow up. There was no difference in HIV or hepatitis C incidence. Conclusions: Consideration should be given to the introduction of prison methadone programs particular where community based programs exist. (C) 2003 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Our previous studies have shown that two distinct genotypes of Sindbis (SIN) virus occur in Australia. One of these, the Oriental/Australian type, circulates throughout most of the Australian continent, whereas the recently identified south-west (SW) genetic type appears to be restricted to a distinct geographic region located in the temperate south-west of Australia. We have now determined the complete nucleotide and translated amino acid sequences of a SW isolate of SIN virus (SW6562) and performed comparative analyses with other SIN viruses at the genomic level. The genome of SW6562 is 11,569 nucleotides in length, excluding the cap nucleotide and poly (A) tail. Overall this virus differs from the prototype SIN virus (strain AR339) by 23% in nucleotide sequence and 12.5% in amino acid sequence. Partial sequences of four regions of the genome of four SW isolates were determined and compared with the corresponding sequences from a number of SIN isolates from different regions of the World. These regions are the non-structural protein (nsP3), the E2 gene, the capsid gene, and the repeated sequence elements (RSE) of the 3'UTR. These comparisons revealed that the SW SIN viruses were more closely related to South African and European strains than to other Australian isolates of SIN virus. Thus the SW genotype of SIN virus may have been introduced into this region of Australia by viremic humans or migratory birds and subsequently evolved independently in the region. The sequence data also revealed that the SW genotype contains a unique deletion in the RSE of the 3'UTR region of the genome. Previous studies have shown that deletions in this region of the SIN genome can have significant effects on virus replication in mosquito and avian cells, which may explain the restricted distribution of this genotype of SIN virus.
Resumo:
Australian mosquitoes were evaluated for their ability to become infected with and transmit a Torres Strait strain of Japanese encephalitis virus. Mosquitoes, which were obtained from either laboratory colonies and collected using Centers for Disease Control and Prevention light traps baited with CO2 and octenol or reared from larvae, were infected by feeding on a blood/sucrose solution containing 10(4.5+/-0.1) porcine stable-equine kidney (PS-EK) tissue culture infectious dose(50)/ mosquito of the TS3306 virus strain. After 14 d, infection and transmission rates of 100% and 81%, respectively, were obtained for a southeast Queensland strain of Culex annulirostris Skuse, and 93% and 61%, respectively, for a far north Queensland strain. After 13 or more days, infection and transmission rates of > 90% and greater than or equal to 50%, respectively, were obtained for southeast Queensland strains of Culex sitiens Wiedemann and Culex quinquefasciatus Say, and a far north Queensland strain of Culex gelidus Theobald. Although infection rates were > 55%, only 17% of Ochlerotatus vigilax (Skuse) and no Cx. quinquefasciatus, collected from far north Queensland, transmitted virus. North Queensland strains of Aedes aegypti L., Ochlerotatus kochi (Donitz), and Verrallina funerea (Theobald) were relatively refractory to infection. Vertical transmission was not detected among 673 F, progeny of Oc. vigilax. Results of the current vector competence study, coupled with high field isolation rates, host feeding patterns and widespread distribution, confirm the status of Cx. annulirostris as the major vector of Japanese encephalitis virus in northern Australia. The relative roles of other species in potential Japanese encephalitis virus transmission cycles in northern Australia are discussed.