Expressed transcripts associated with high rates of egg production in chicken ovarian follicles.

The purpose of this study was to characterize differentially expressed transcripts associated with varying rates of egg production in Taiwan country chickens. Ovarian follicles were isolated from two strains of chicken which showed low (B) or high (L2) rates of egg production, then processed for RNA extraction and cDNA library construction. Three thousand and eight forty clones were randomly selected from the cDNA library and amplified by PCR, then used in microarray analysis. Differentially expressed transcripts (P<0.05, log(2)> or = 1.75) were sequenced, and aligned using GenBank. This analysis revealed 20 non-redundant sequences which corresponded to known transcripts. Eight transcripts were expressed at a higher level in ovarian tissue prepared from chicken strain B, and 12 transcripts were expressed at a higher level in L2 birds. These differential patterns of expression were confirmed by semi-quantitative RT-PCR. We show that transcripts of cyclin B2 (cycB2), ferritin heavy polypeptide 1 (FTH1), Gag-Pol polyprotein, thymosin beta4 (TB4) and elongation factor 1 alpha1 (EEF1A1) were enriched in B strain ovarian follicles. In contrast, thioredoxin (TXN), acetyl-CoA dehydrogenase long chain (ACADL), inhibitor of growth family member 4 (ING4) and annexin II (ANXA2) were expressed in at higher levels in the L2 strain. We suggest that our approach may lead to the isolation of effective molecular markers that can be used in selection programs in Taiwan country chickens.

Surgical resection for metastatic melanoma to the liver: the John Wayne Cancer Institute and Sydney Melanoma Unit experience.

HYPOTHESIS: Metastatic melanoma to the liver is not incurable; complete surgical resection can achieve long-term survival in selected patients. BACKGROUND: Metastases to the liver are diagnosed in 10% to 20% of patients with American Joint Committee on Cancer stage IV melanoma. Surgical resection has not been generally accepted as a therapeutic option, as most patients will have other sites of disease that limit their survival to a median of only 4 to 6 months. However, there is little information on outcomes following resection in those patients with disease limited to the liver. PATIENTS AND METHODS: Review of the prospective melanoma databases at the John Wayne Cancer Institute, Santa Monica, Calif, and the Sydney Melanoma Unit, Sydney, Australia, identified 1750 patients with hepatic metastases, of whom 34 (2%) underwent exploration with intent to resect the metastases. Prognostic factors within the group of patients who underwent resection were examined by univariate and multivariate analysis, and median disease-free survival (DFS) and overall survival (OS) were calculated. RESULTS: Of 34 patients undergoing exploratory celiotomy, 24 (71%) underwent hepatic resection and 10 (29%) underwent exploration but not resection. Eighteen patients (75%) underwent complete surgical resection, while the remaining 6 underwent palliative or debulking procedures with incomplete resection. The operative resections included lobectomy (n=14), segmentectomy (4), nonanatomic resection (5), and extended lobectomy (1). The median number of resected lesions was 1, and median lesion size was 5 cm (range, 0.7-22 cm). The median disease-free interval between initial diagnosis of melanoma and development of hepatic metastases was 58 months (range, 0-264 months). Median DFS and OS estimates in the 24 patients who underwent surgical resection were 12 months (range, 0-147 months) and 28 months (range, 2-147 months), respectively. Five-year DFS and OS in this group were 12% and 29%. Macroscopically, complete resection of disease (P =.001) and histologically negative resection margins (P =.03) significantly improved DFS by univariate analysis. Patients rendered surgically free of disease also tended to have improved OS (P =.06). Median OS was 28 months for patients who underwent surgical resection compared with 4 months for patients who underwent exploration only (P<.001). CONCLUSIONS: Resection of metastatic melanoma to the liver may improve DFS and OS in selected patients, similar to resection of other metastatic sites. Therefore, patients with limited metastatic sites, including the liver, who can be rendered free of disease should be considered for complete surgical resection, as their prognosis is otherwise dismal.

Purification and cloning of cytotoxic ribonucleases from Rana catesbeiana (bullfrog).

Ribonucleases with antitumor activity are mainly found in the oocytes and embryos of frogs, but the role of these ribonucleases in frog development is not clear. Moreover, most frog ribonuclease genes have not been cloned and characterized. In the present study, a group of ribonucleases were isolated from Rana catesbeiana (bullfrog). These ribonucleases in mature oocytes, namely RC-RNase, RC-RNase 2, RC-RNase 3, RC-RNase 4, RC-RNase 5 and RC-RNase 6, as well as liver-specific ribonuclease RC-RNase L1, were purified by column chromatographs and detected by zymogram assay and western blotting. Characterization of these purified ribonucleases revealed that they were highly conserved in amino acid sequence and had a pyroglutamate residue at their N-termini, but possessed different specific activities, base specificities and optimal pH values for their activities. These ribonucleases were cytotoxic to cervical carcinoma HeLa cells, but their cytotoxicities were not closely correlated to their enzymatic specific activities. Some other amino acid residues in addition to their catalytic residues were implicated to be involved in the cytotoxicity of the frog ribonucleases to tumor cells. Because the coding regions lack introns, the ribonuclease genes were cloned by PCR using genomic DNA as template. Their DNA sequences and amino acid sequences are homologous to those of mammalian ribonuclease superfamily, approximately 50 and approximately 25%, respectively.

The effects of cell size and ploidy on cell allocation in mouse chimaeric blastocysts.

In a previous study of mouse tetraploid<-->diploid chimaeric blastocysts, tetraploid cells were found to be more abundant in the trophectoderm than the inner cell mass (ICM) and more abundant in the mural trophectoderm than the polar trophectoderm. This non-random allocation of tetraploid cells to different regions of the chimaeric blastocyst may contribute to the restricted tissue distribution seen in post-implantation stage tetraploid<-->diploid chimaeras. However, the tetraploid and diploid embryos that were aggregated together differed in several respects: the tetraploid embryos had fewer cells and these cells were bigger and differed in ploidy. Each of these factors might underlie a non-random allocation of tetraploid cells to the chimaeric blastocyst. A combination of micromanipulation and electrofusion was used to produce two series of chimaeras that distinguished between the effects of cell size and ploidy on the allocation of cells to different tissues in chimaeric blastocysts. When aggregated cells differed in cell size but not ploidy, the derivatives of the larger cell contributed significantly more to the mural trophectoderm and polar trophectoderm than the ICM. When aggregated cells differed in ploidy but not cell size, the tetraploid cells contributed significantly more to the mural trophectoderm than the ICM. In both experiments the contributions to the polar trophectoderm tended to be intermediate between those of the mural trophectoderm and ICM. These experiments show that both the larger size and increased ploidy of tetraploid cells could have contributed to the non-random cell distribution that was observed in a previous study of tetraploid<-->diploid chimaeric blastocysts.

Matrix metalloproteinase inhibitors reduce phorbol ester-induced cutaneous inflammation and hyperplasia.

Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteases which play key roles in extracellular matrix remodeling, connective tissue damage, inflammation and cell proliferation in a variety of tissues. Since MMP inhibitors have been recently shown to decrease proliferation of vascular smooth-muscle cells, and to prevent neutrophil infiltration in response to alkali burns, we sought to determine whether MMPs play a role in the pathogenesis of inflammatory or hyperproliferative skin disorders. The effects of a specific MMP inhibitor and its analogues on phorbol dibutyrate (PdiBu)-induced inflammation and epidermal hyperplasia in murine skin were assessed. Topical GM 6001, a hydroxamic acid analog with potent inhibitory activity against several MMPs, markedly inhibited PdiBu-induced increases in both ear thickness and ear punch-biopsy weight in a dose-dependent manner 30 h after topical application of PdiBu. Maximal inhibition (75%) was obtained at a dose of 100 micrograms/cm2 (P < 0.01). Moreover, histologic analysis revealed that GM 6001 decreased both the inflammatory cellular infiltrates and epidermal hyperplasia induced by PdiBu. Whereas similar results were found for GM 1489, an analog of GM 6001, acetohydroxamic acid, containing the critical metal ligand group but without the amino acid side chains necessary for binding to the MMPs, did not alter the response to PdiBu inflammation/hyperplasia. These results show that the MMP inhibitors, GM 6001 and GM 1489, are effective in reducing both the inflammatory and hyperproliferative responses that occur following topical phorbol ester application, suggesting a potential role for MMPs in cutaneous inflammatory dermatoses. Moreover, the delivery of this class of inhibitors across intact stratum corneum implies that MMP inhibition could provide an approach to the topical treatment of inflammatory dermatoses.