Infection with multiple sexually transmitted agents has been associated with inflammation of the cervix and an increased risk of cervical cancer in women infected with human papillomaviruses (HPVs). Two proinflammatory cytokines, interleukin la (IL-la) and tumor necrosis factor a (TNF-a), inhibited proliferation of normal epithelial cells cultured from human cervix. In contrast, both cytokines significantly stimulated proliferation of cervical cell lines (5 of 7) immortalized by transfection with HPV-16 or -18 DNAs or lines derived from cervical carcinomas (7 of 11). Stimulation was dose dependent from 0.01 to 1.0 nM and was blocked by specific inhibitors, such as the IL-1 receptor antagonist or the TNF type 1 or 2 soluble receptors. Growth stimulation by IL-la or TNF-a was accompanied by a 6-to 10-fold increase in RNA encoding amphiregulin, an epidermal growth factor (EGF) receptor ligand. Recombinant human amphiregulin (0.1 nM) was as effective as IL-la or TNF-a in promoting proliferation. Monoclonal antibodies that blocked signal transduction by the EGF receptor or that neutralized amphiregulin activity prevented mitogenic stimulation by IL-la or TNF-a. These studies indicate that IL-la and TNF-a stimulate proliferation of immortal and malignant cervical epithelial cells by an EGF receptor-dependent pathway requiring autocrine stimulation by amphiregulin. Furthermore, they suggest that chronic inflammation and release of proinflammatory cytokines might provide a selective growth advantage for abnormal cervical cells in vivo.
During a research cruise in July 1997 in the Gulf of Mexico we discovered a gas hydrate approximately 1 m thick and over 2 m in diameter which had recently breached the sea floor at a depth of 540 m. The hydrate surface visible from the submarine was considerably greater than that of any other reported hydrate. Two distinct color bands of hydrate were present in the same mound, and the entire exposed surface of the hydrate was infested (2500 individuals/m2) with 2 to 4 cm-long worms, since described as a new species, Hesiocaeca methanicola, in the polychaete family Hesionidae (Desbruyères and Toulmond 1998). H. methanicola tissue stable isotope values are consistent with a chemo-autotrophic food source. No evidence of chemo-autotrophic symbionts was detected, but geochemical data support the presence of abundant free living bacteria on the hydrate. The activities of the polychaetes, grazing on the hydrate bacteria and supplying oxygen to their habitats, appears to contribute to the dissolution of hydrates in surface sediments.
The vestimentiferan tubeworms Lamellibrachia luymesi and Seepiophila jonesi are found at hydrocarbon seeps in the Gulf of Mexico. Primers for polymorphic microsatellite loci were developed from genomic libraries of L. luymesi (five loci) and from S. jonesi tissue (eight loci) and were used to screen individuals collected from nine northern Gulf of Mexico hydrocarbon seep sites. Loci had from four to more than 50 alleles with high expected levels of heterozygosity. Cross-species amplification, tested on seven vestimentiferan species including both hydrothermal vent and cold seep species, was generally strong in similar species but weak in more genetically distant species.
The presence of the freshwater polychaete, Namanereis hummelincki (Augener), on Montserrat is documented for the first time. Although collected in the sediment of a freshwater stream, this subterranean species most likely lives in groundwater aquifers. A mitochondrial cytochrome c oxidase subunit I (COI) sequence obtained from this material supports assignment to the genus Namanereis Chamberlin, and morphological analysis supports identification as N. hummelincki. Differences in jaw morphology observed in the Montserrat specimens may indicate long-term separation from other Caribbean island populations.
The Lake Victoria haplochromine cichlids comprise a unique 'species flock' of over 500 historic species, of which perhaps only half still exist because of the introduction of invasive species and eutrophication of the Lake. Dr Les Kaufman supervised the establishment of captive populations of those cichlids he was able to acquire from Africa and Europe by developing the first North American regional studbook. Long-term propagation of these fish was then undertaken by public aquariums in Europe and North America. One species, the Pitch-black fulu Haplochromis piceatus, stands out as it has thrived at public aquariums and within the organizational structure of the Association of Zoos and Aquariums Species Survival Plans. These cooperative breeding programmes focus on the conservation of select species of threatened animals. Captive populations of H. piceatus at public aquariums in the United States show a relatively slow loss of genetic diversity. Additionally, fish in at least two breeding programmes show a higher than expected heterozygosity, indicating that these programmes are successfully keeping their fish from inbreeding. The husbandry and genetic management of this population of fish is outlined, hopefully providing useful information for nascent breeding programmes of other aquatic species at zoos and aquariums around the world.
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