Long-term stability in the richness and structure of helminth communities in eels,Anguilla anguilla,in Lough Derg,River Shannon,Ireland

A data set on intestinal helminth parasites was collected in the course of an 18 year investigation into the biology of eels in Meelick Bay, Lough Derg, River Shannon. This was used to test two hypotheses relating to the composition and structure of intestinal helminth communities, namely that eels in large rivers do not harbour richer and more diverse communities than those in small rivers but that community composition and structure are more stable over time than in small rivers. The helminth community was species poor, with only six species comprising the component community and a maximum infracommunity richness of three species. The community was overwhelmingly dominated by the acanthocephalan Acanthocephalus lucii, reflecting the importance of its intermediate host Asellus aquaticus in the eels' diet. The remaining helminth species contributed to species richness but made very little contribution to community diversity. Population levels of Acanthocephalus lucii fell and remained low between 1992 and 2000, probably reflecting increased movement of eels from other parts of the lough into Meelick Bay. Diversity values were low, but similar to those reported from other rivers in Britain and Europe. The results provided support for both hypotheses and indicated that in respect of richness, diversity and dominance, the helminth communities of eels in the River Shannon were typical of, and comparable to, those of other large rivers throughout Europe.     

High-performance liquid chromatographic assay for the determination of a semisynthetic avermectin analog (eprinomectin) in bovine milk at parts per billion levels--method development and validation

A reversed-phase HPLC method for the quantitative determination of total topotecan in human whole blood and unwashed erythrocytes has been developed and validated in terms of sensitivity, specificity, precision and accuracy. Linear calibration curves were constructed in the range of 0.20 to 50.0 ng/ml. The sample pre-treatment for whole blood involved a two-step extraction with methanol and perchloric acid. Prior to extraction, erythrocytes were separated from other blood components by centrifugation in MESED instruments. Separations were achieved on an Inertsil ODS-80A analytical column (150x4.6 mm, 5 microm particle size), eluted at 50 degrees C and a flow-rate of 1.00 ml/min, with a mixture of 100 mM ammonium acetate (pH 6.0)-tetrahydrofuran (94.6:5.4, v/v). Fluorescence detection was performed using excitation and emission wavelengths of 381 and 525 nm, respectively. With the applied method, 80% of topotecan was extracted out of whole blood. The lower limit of quantitation in whole blood was established at 0.20 ng/ml with within-run and between-run precisions, respectively, ranging from 1.7 to 9.3% and 1.5-6.1%, while the accuracy ranged from 100 to 113%. The described method will be used in clinical studies to explore the role of erythrocytes in the overall kinetic behavior of topotecan.     

Phylogeny of the Drosophila saltans species group based on combined analysis of nuclear and mitochondrial DNA sequences

Nucleotide sequences from two nuclear loci, alcohol dehydrogenase and internal transcribed spacer-1 of the nuclear ribosomal DNA repeats, and two mitochondrial genes, cytochrome oxidase I and cytochrome oxidase II, were determined from nine species in the Drosophila saltans species group. The partition homogeneity test and partitioned Bremer support were used to measure incongruence between phylogenetic hypotheses generated from individual partitions. Individual loci were generally congruent with each other and consistent with the previously proposed morphological hypothesis, although they differed in level of resolution. Since extreme conflict between partitions did not exist, the data were combined and analyzed simultaneously. The total evidence method gave a more resolved and highly supported phylogeny, as indicated by bootstrap proportions and decay indices, than did any of the individual analyses. The cordata and elliptica subgroups, considered to have diverged early in the history of the D. saltans group, were sister taxa to the remainder of the saltans group. The sturtevanti subgroup, represented by D. milleri and D. sturtevanti, occupies an intermediate position in this phylogeny. The saltans and parasaltans subgroups are sister clades and occupy the most recently derived portion of the phylogeny. As with previous morphological studies, phylogenetic relationships within the saltans subgroup were not satisfactorily resolved by the molecular data.      

Variations in the response of enzyme-dissociated rat pituitary cells to thyrotropin releasing hormone.

While exploring the interaction between thyrotropin releasing hormone (TRH) and normal rat anterior pituitary cells in monolayer culture we observed that cells dissociated with the use of trypsin did not respond to TRH with an increase in either TSH or prolactin (PRL) release. The dissociated cells were cultured for 3 days, then washed to remove serum proteins and exposed to 10^?6M TRH for 3 hours. TSH and PRL secretion from stimulated and unstimulated cultures was determined by radio-immunoassay and normalized using cell protein. When such trypsin-dissociated cells were exposed to 0.5 mM dibutyryl cyclic AMP the release of both TSH and PRL doubled indicating that the intracellular secretory machinery was functional and that the block to TRH was proximal to the formation of cyclic AMP and presumably at the level of a TRH surface receptor. Previous studies have shown that such trypsin-dissociated cells respond to LHRH and a crude hypothalamic extract with a dose dependent increase in LH, FSH and ACTH release. This rules out a non-specific effect of trypsin. When pituitary cells were dissociated with a non-trypsin technique, the unstimulated release of both TSH and PRL was comparable to that found with the trypsin-dissociated cultures. However, these cultures did respond to TRH with an increase in TSH release although again no effect was seen with PRL. The susceptibility of the cells to trypsin suggests the possibility that a protein moiety may be closely associated with the function of the receptor.     

The position of heterologous epitopes inserted in hepatitis B virus core particles determines their immunogenicity.

The nucleocapsid (HBcAg) of the hepatitis B virus (HBV) has been suggested as a carrier moiety for vaccine purposes. We investigated the influence of the position of the inserted epitope within hybrid HBcAg particles on antigenicity and immunogenicity. For this purpose, genes coding for neutralizing epitopes of the pre-S region of the HBV envelope proteins were inserted at the amino terminus, the amino terminus through a precore linker sequence, the truncated carboxy terminus, or an internal site of HBcAg by genetic engineering and were expressed in Escherichia coli. All purified hybrid HBc/pre-S polyproteins were particulate. Amino- and carboxy-terminal-modified hybrid HBc particles retained HBcAg antigenicity and immunogenicity. In contrast, insertion of a pre-S(1) sequence between HBcAg residues 75 and 83 abrogated recognition of HBcAg by 5 of 6 anti-HBc monoclonal antibodies and diminished recognition by human polyclonal anti-HBc. Predictably, HBcAg-specific immunogenicity was also reduced. With respect to the inserted epitopes, a pre-S(1) epitope linked to the amino terminus of HBcAg was not surface accessible and not immunogenic. A pre-S(1) epitope fused to the amino terminus through a precore linker sequence was surface accessible and highly immunogenic. A carboxy-terminal-fused pre-S(2) sequence was also surface accessible but weakly immunogenic. Insertion of a pre-S(1) epitope at the internal site resulted in the most efficient anti-pre-S(1) antibody response. Furthermore, immunization with hybrid HBc/pre-S particles exclusively primed T-helper cells specific for HBcAg and not the inserted epitope. These results indicate that the position of the inserted B-cell epitope within HBcAg is critical to its immunogenicity.     

Using a nursing protocol to assure equitable delivery of cancer-related prevention services.

A nurse-administered, protocol-driven model (NP) for preventive services delivery was compared with a traditional physician reminder (PR) model with nursing back-up among 473 patients attending Internal Medicine and Family Medicine clinics. A total of 240 patients were randomized to the NP group and 233 to the PR group. Demographic characteristics including gender [71% female (NP) and 71% female (PR)], race (78% and 75% African American, respectively) and age (numbers of persons aged 18-54, 55-64 and 65+ years) were similar in each group. In the NP group 244/244 screening tests for breast, cervical and colon cancers and alcohol abuse were initiated or completed by nurses, while in the PR group 110/215 (51%) were initiated or completed by physicians. The NP group received 552/552 counseling services from nurses for tobacco, alcohol, nutrition, exercise and prostate screening, while in the PR group, physicians delivered 10% of the needed services (56/560). Aside from counseling for prostate cancer screening, which was 100% in both the NP and PR groups, all other between-group differences for each service were significant at the level of p<0.001. Results show the feasibility of a nursing protocol for initiating equitable cancer prevention services in a primary care setting.     

Maple phylogeny and biogeography inferred from phylogenomic data

Acer (the maple genus) is one of the diverse tree genera in the Northern Hemisphere with about 152 species, most of which are in eastern Asia. There are roughly a dozen species in Europe/western Asia and a dozen in North America. Several phylogenetic studies of Acer have been conducted since 1998, but none have provided a satisfactory resolution for basal relationships among sections of Acer. Here we report the first well‐resolved phylogeny of Acer based on DNA sequences of over 500 nuclear loci generated using the anchored hybrid enrichment method and explore the implications of the robust phylogeny for Acer systematics and biogeography. Our phylogenetic results support the most recent taxonomic treatment of Acer by de Jong with some modifications; section Pentaphylla may be expanded to include section Trifoliata, and A. yangbiense may be included in section Lithocarpa. Sections Spicata, Negundo, Arguta, and Palmata form a clade sister to the rest of the genus where sections Glabra and Parviflora comprise the first clade followed by section Macrantha, sections Ginnala, Lithocarpa, Indivisa, sections Platanoidea and Macrophylla, section Rubra, section Acer, and section Pentaphylla. Monotypic sections Glabra and Macrophylla in North America are sister to the Japanese section Parviflora and Eurasian section Platanoidea, respectively. Ancestral area inferences using statistical dispersal and vicariance analysis (S‐DIVA) and dispersal and extinction cladogenesis (DEC) methods suggest that Asia might be the most likely ancestral area of Acer as proposed by Wolfe and Tanai and molecular dating using Bayesian evolutionary analysis by sampling trees (BEAST) indicate that section diversifications of Acer might have completed largely in the late Eocene and the intercontinental disjunctions of Acer between eastern Asia and eastern North America formed mostly in the Miocene.