Southern bluefin tuna (SBT) is a valuable species that has been subject to high exploitation rates since the 1950s. In 2011, the spawning stock biomass was estimated to be at a historically low level, at only 5% of pre-fished biomass. A key component for managing and rebuilding the stock is having reliable, fishery-independent estimates of juvenile abundance.
View Article and Find Full Text PDFAdvances in DNA sequencing technology have revolutionized the field of molecular analysis of trophic interactions, and it is now possible to recover counts of food DNA sequences from a wide range of dietary samples. But what do these counts mean? To obtain an accurate estimate of a consumer's diet should we work strictly with data sets summarizing frequency of occurrence of different food taxa, or is it possible to use relative number of sequences? Both approaches are applied to obtain semi-quantitative diet summaries, but occurrence data are often promoted as a more conservative and reliable option due to taxa-specific biases in recovery of sequences. We explore representative dietary metabarcoding data sets and point out that diet summaries based on occurrence data often overestimate the importance of food consumed in small quantities (potentially including low-level contaminants) and are sensitive to the count threshold used to define an occurrence.
View Article and Find Full Text PDFClimate influences marine ecosystems on a range of time scales, from weather-scale (days) through to climate-scale (hundreds of years). Understanding of interannual to decadal climate variability and impacts on marine industries has received less attention. Predictability up to 10 years ahead may come from large-scale climate modes in the ocean that can persist over these time scales.
View Article and Find Full Text PDFDNA metabarcoding is a powerful new tool allowing characterization of species assemblages using high-throughput amplicon sequencing. The utility of DNA metabarcoding for quantifying relative species abundances is currently limited by both biological and technical biases which influence sequence read counts. We tested the idea of sequencing 50/50 mixtures of target species and a control species in order to generate relative correction factors (RCFs) that account for multiple sources of bias and are applicable to field studies.
View Article and Find Full Text PDFThe demographics of the southern bluefin tuna (SBT) Thunnus maccoyii spawning stock were examined through a large-scale monitoring program of the Indonesian longline catch on the spawning ground between 1995 and 2012. The size and age structure of the spawning population has undergone significant changes since monitoring began. There has been a reduction in the relative abundance of larger/older SBT in the catch since the early 2000s, and a corresponding decrease in mean length and age, but there was no evidence of a significant truncation of the age distribution.
View Article and Find Full Text PDFTransforming growth factor-β (TGF-β) is known to act as a tumour suppressor early in carcinogenesis, but then switches to a pro-metastatic factor in some late stage cancers. However, the actions of TGF-β are context dependent, and it is currently unclear how TGF-β influences the progression of human squamous cell carcinoma (SCC). This study examined the effect of overexpression of TGF-β1 or TGF-β2 in Ras-transfected human malignant epidermal keratinocytes that represent the early stages of human SCC.
View Article and Find Full Text PDFBackground: The aim was to determine whether Bcl-2-associated athanogene-1 (Bag-1) and/or its binding protein heat shock protein-70 (Hsp70) exhibit deregulated expression in epidermal squamous cell carcinoma (SCC) and whether Bag-1 confers apoptosis resistance.
Method: Immunohistochemistry for Bag-1 and Hsp70 was performed on 60 epidermal SCC and 10 normal skin samples. The epidermal SCC cell line SCC-13 was treated with 5-fluorouracil (5-FU) after Bag-1 knockdown to determine whether high Bag-1 levels contribute to growth and/or apoptosis resistance.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod
October 2010
Squamous cell carcinomas (SCC) of minor salivary gland origin are extremely rare. We present an unusual case of a 29-year-old female patient who presented with a well-differentiated SCC of minor salivary gland origin arising in the lower lip. Wedge resections of the lip, including bilateral mental nerve excision, were required to clear the tumor because of striking pathological evidence of perineural invasion distant from the primary tumor site.
View Article and Find Full Text PDFIt is now generally accepted that TGF-β acts as a pro-metastatic factor in advanced human breast cancer. However, it is well documented, that TGF-β is context dependent, and whether the TGF-β pathway switches to promote metastasis during the progression of squamous cell carcinoma (SCC) is unknown. This study examined the role of TGF-β signalling in SCC using a series of genetically related keratinocyte cell lines representing later stages of the disease, stably transduced with a dominant negative TβRII cDNA (dnTβRII).
View Article and Find Full Text PDFBr J Oral Maxillofac Surg
September 2008
Diffuse, non-inflammatory, non-neoplastic enlargement of the major salivary glands (sialosis) is uncommon and has various systemic causes. This paper examines 35 patients whose persistent swelling of the parotid was diagnosed as sialosis, and shows that diabetes mellitus and alcoholism are the most common causes.
View Article and Find Full Text PDFInt J Oral Maxillofac Surg
January 2007
Neural invasion is a relatively common feature of squamous cell carcinomas of the head and neck and malignant salivary gland tumours. The symptoms depend on the location and the particular nerves involved, and include pain, anaesthesia, paraesthesia and cranial nerve palsy. The present case appears to be unique.
View Article and Find Full Text PDFRadial forearm free flaps are used routinely to reconstruct oro-facial tissues following resection of oral squamous cell carcinoma. Surprisingly, there is little information regarding their behaviour following engraftment. The present report is a clinico-pathological study of 10 patients who had incisional biopsies of cutaneous free flaps after the presence of a white patch or erythema raised clinical suspicion.
View Article and Find Full Text PDFBackground: Poorly preserved biological tissues have become an important source of DNA for a wide range of zoological studies. Measuring the quality of DNA obtained from these samples is often desired; however, there are no widely used techniques available for quantifying damage in highly degraded DNA samples. We present a general method that can be used to determine the frequency of polymerase blocking DNA damage in specific gene-regions in such samples.
View Article and Find Full Text PDFBackground: The presence of lichenoid or granulomatous inflammation in an oral mucosal biopsy usually suggests a distinct range of diagnostic possibilities. However, the presence of both patterns of inflammation in the same biopsy is uncommon.
Methods: A clinico-pathological study of six patients.
Int J Oral Maxillofac Surg
December 2004
Salivary gland involvement, particularly salivary gland enlargement (sialosis), is a recognised complication in bulimia. We report the rare association of sialosis and necrotising sialometaplasia with bulimia in the same patient. The association of sialosis and necrotising sialometaplasia in the same patient with bulimia has been reported previously in two patients and may be coincidental, but the appearance in this additional patient suggests it may be prudent to explore this further.
View Article and Find Full Text PDFOral carcinomas are known to have a greater apoptotic index than normal oral epithelium, evident as shrinking cells with condensed chromatin. In this study, these morphologically apoptotic cells stained positively for cleaved (active) caspase-3. In normal oral epithelium, cleaved caspase-3 positive-cells were only rarely detected.
View Article and Find Full Text PDFThis study examined the behaviour of nine human malignant oral keratinocyte cell lines following orthotopic transplantation to the floor of the mouth of athymic mice. Tumourigenesis, local spread, and metastatic dissemination were correlated with known cellular responses to transforming growth factor-beta 1 (TGF-beta 1). Six of nine cell lines were tumourigenic; four of these cell lines showed local spread which was characterized by vascular and bone invasion.
View Article and Find Full Text PDFWe examined the effect of stable transfection of dominant negative TbetaR-II (dn TbetaR-II) cDNA in a human oral carcinoma cell line that contained normal Ras and was growth inhibited by TGF-beta1. Two clonal cell lines containing dn TbetaR-II were isolated and compared to the vector-only control and parent cell line. The treatment of cells with exogenous TGF-beta1 resulted in a decrease in ligand-induced growth inhibition and loss of c-myc downregulation in test cells compared to controls; transcriptional activation of certain genes including fra-1 and collagenase was retained.
View Article and Find Full Text PDFJ Vet Med A Physiol Pathol Clin Med
October 2003
Basal cell adenocarcinoma of the salivary gland is described in a cat and two dogs; tumour tissue was characterized by cords and islands of epithelial cells with a distinct basal layer. The tumours were stained by various immunohistochemical methods. In addition to positive staining with cytokeratin 14 and pancytokeratin (CKs 5, 6, 8, 17 and 19), there was also staining with Jack bean agglutinin A (ConA) and soya bean agglutinin (SBA); this occurs in many other types of salivary gland tumours and is a feature of normal salivary gland acinar cells.
View Article and Find Full Text PDFIntramuscular vascular lesions in the tongue are rare and are usually the capillary form of haemangioma. A case is described of a lingual mass that resembled intramuscular haemangioma but had unique histological features that do not appear to have been described previously. The term intramuscular capillary hamartoma is suggested to describe it.
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