Expert range maps of global mammal distributions harmonised to three taxonomic authorities

AIM

Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW).

LOCATION

Global.

TAXON

All extant mammal species.

METHODS

Range maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species).

RESULTS

Range maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use.

MAIN CONCLUSION

Expert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control.

Phylogenetic and morphological significance of an overlooked flying squirrel (Pteromyini, Rodentia) from the eastern Himalayas with the description of a new genus

The flying squirrels (Pteromyini, Rodentia) are the most diverse and widely distributed group of gliding mammals. Taxonomic boundaries and relationships within flying squirrels remain an area of active research in mammalogy. The discovery of new specimens of Pteromys (Hylopetes) leonardi Thomas, 1921, previously considered a synonym of Hylopetes alboniger, in Yunnan Province, China allowed a morphological and genetic reassessment of the status of this taxon. Phylogenetic reconstruction was implemented using sequences of two mitochondrial (12S ribosomal RNA and 16S ribosomal RNA) and one nuclear (interphotoreceptor retinoid-binding protein) gene fragments. Morphological assessments involved examinations of features preserved on skins, skulls, and penises of museum specimens, supplemented with principal component analysis of craniometric data. Together these assessments revealed that this taxon should be recognized not only as a distinct species, but should also be placed within a new genus, described here as Priapomysgen. nov.

Across the great divide: revision of the genus Eupetaurus (Sciuridae: Pteromyini), the woolly flying squirrels of the Himalayan region, with the description of two new species

The woolly flying squirrel, Eupetaurus cinereus, is among the rarest and least studied mammals in the world. For much of the 20th century it was thought to be extinct, until it was rediscovered in 1994 in northern Pakistan. This study outlines the first taxonomic and biogeographical review of the genus Eupetaurus, which until now has contained only a single species. Careful review of museum specimens and published records of Eupetaurus demonstrates that the genus occurs in three widely disjunct areas situated on the western (northern Pakistan and north-western India), north-central (south-central Tibet, northern Sikkim and western Bhutan) and south-eastern margins (north-western Yunnan, China) of the Himalayas. Taxonomic differentiation between these apparently allopatric populations of Eupetaurus was assessed with an integrative approach involving both morphological examinations and molecular phylogenetic analyses. Phylogenetic reconstruction was implemented using sequences of three mitochondrial [cytochrome b (Cytb), mitochondrially encoded 12S and 16S ribosomal RNA (12S, 16S)] and one nuclear [interphotoreceptor retinoid-binding protein (IRBP)] gene fragment. Morphological assessments involved qualitative examinations of features preserved on museum skins and skulls, supplemented with principal components analysis of craniometric data. Based on genetic and morphological comparisons, we suggest that the three widely disjunct populations of Eupetaurus are each sufficiently differentiated genetically and morphologically to be recognized as distinct species, two of which are described here as new.

Landscape management of the mahogany glider (Petaurus gracilis) across its distribution: subpopulations and corridor priorities

Key threatening processes to biodiversity include habitat loss and fragmentation, with populations restricted to small fragments of habitat being more prone to extinction. The mahogany glider (Petaurus gracilis) is endemic to sclerophyll woodland forests between Tully and Ingham in north Queensland and is one of Australia’s most endangered arboreal mammals due to these processes. The aim of this study was to identify the degree of habitat fragmentation of the remaining remnant vegetation of the mahogany glider, identify subpopulations within its distribution and identify key wildlife corridors for restoration to facilitate the movement of this species within and between subpopulations. Ten glider subpopulations, spread over 998 habitat fragments, were identified, of which only five subpopulations may currently be considered to be viable. To assist in providing habitat connectivity between and within the subpopulations, 55 corridors were identified for restoration that had an average length of 8.25 km. The average number of gaps greater than 30 m was 3.4 per corridor, with the average length of these gaps being 523 m. This study confirmed a high degree of habitat fragmentation across the distribution of the mahogany glider and highlighted the need to strengthen the remaining subpopulations by restoring habitat connectivity between the remaining habitat fragments.

Discovery and description of a mysterious Asian flying squirrel (Rodentia, Sciuridae, Biswamoyopterus) from Mount Gaoligong, southwest China

The flying squirrels of the tribe Pteromyini (Family Sciuridae) currently include 15 genera of which the genus Biswamoyopterus comprises two recognized species, B.biswasi Saha, 1981 and B.laoensis Sanamxay et al., 2013. These two species were each described from only one specimen that are separated from each other by 1,250 kilometres in southern Asia, where they occur in northeast India and central Lao PDR respectively. In 2017 and 2018, two specimens of Biswamoyopterus were discovered from Mount Gaoligong, west Yunnan province, southwest China (between the type locality of the two recognized species). This study aimed to evaluate the taxonomic status of these two newly acquired specimens of Biswamoyopterus by comparing their morphology with the two described species of the genus. The results of this study showed that the specimens from Yunnan province (China) differed from both B.laoensis and B.biswasi in both pelage colour and craniology, and should be recognised as a distinct species, B.gaoligongensissp. nov., which is formally described here. This study contributes to the understanding of the flying squirrels of southern Asia and identifies an additional species that appears to be endemic to southwest China; however, more research is required to provide details of its ecology, distribution, and conservation status.

Abstract 5201: Using Taqman assays to verify eQTL links arising from GWAS studies

Tremendous progress has been made using genome-wide association studies (GWAS) to link genetic variation with phenotypes and pathologies. In spite of these success, it has been estimated that as many as 90% of SNPs identified in GWAS studies map to non-coding regions, complicating the mechanistic interpretation of the results. It is thought that these non-coding SNPs fall into regulatory regions and influence the expression of a gene or genes. The study of expression quantitative trait loci (eQTLs) provides a method for understanding the link between genetic variants and altered gene expression, and could potentially provide new insights connecting GWAS results to molecular mechanisms. To illustrate how eQTLs can be found and verified, we generated transcriptomic information from various tumor samples using Applied Biosystems’ Clariom D microarrays. We also generated SNP genotyping data from the same samples using Applied Biosystems’ Axiom UK Biobank microarrays. To find putative eQTLs, we compared the SNPs genotypes and the gene expression levels in these samples to the GTEx database. Potential eQTLs in this set of samples were verified using Applied Biosystems’ Taqman SNP Genotyping and Taqman Gene Expression assays. We therefore illustrate a workflow where candidate eQTLs can be confirmed and screened in larger cohorts using the more economical qPCR reagents available from Applied Biosystems.

Citation Format: Stephen M. Jackson, Harita Veereshlingham, Kamini Varma. Using Taqman assays to verify eQTL links arising from GWAS studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5201.

Growth and development of the Mahogany Glider (Petaurus gracilis)

The growth and development of the endangered Mahogany Glider (Petaurus gracilis) was monitored in a captive population at Burleigh Heads, Queensland, Australia. Video surveillance confirmed that the gestation period for this species was 16 days. Morphometric data and developmental milestones were recorded from 10 Mahogany Gliders from birth to weaning. Growth curves were developed for head length, ulna length, tail length, and body weight. Weekly inspections of female pouches revealed the young's eyelid margins were visible by Day 21, the first hair erupted on the bridge of the nose at Day 30, pigmentation of the body developed at Day 63, and they started detaching from the teat intermittently, and the body was covered in short fur by Day 70. The young were left in the nest alone from Days 84 to 87, their eyes opened between Days 84 and 94, and there was a rapid increase in length and density of fur from Day 98 onwards. At Days 101 to 105 of age the young left the nest box with its mother as back young. Weaning occurred from 184 to 187 days. Typically, the reproductive rate was two young per annum per pair, but one pair produced five young in 19 months. Females produced young from 12 months to 7 years of age, males up to 9.4 years of age. The average longevity of Mahogany Gliders in the studbook in 2018 was 11.6 years. This study provides data on the reproductive biology of the Mahogany Glider that will assist in its captive breeding, management, and conservation.

The Dogma of Dingoes-Taxonomic status of the dingo: A reply to Smith et al

Adopting the name Canis dingo for the Dingo to explicitly denote a species-level taxon separate from other canids was suggested by Crowther et al.  (2014) as a means to eliminate taxonomic instability and contention. However, Jackson et al.  (2017), using standard taxonomic and nomenclatural approaches and principles, called instead for continued use of the nomen C. familiaris for all domestic dogs and their derivatives, including the Dingo. (This name, C. familiaris, is applied to all dogs that derive from the domesticated version of the Gray Wolf, Canis lupus, based on nomenclatural convention.) The primary reasons for this call by Jackson et al.  (2017) were: (1) a lack of evidence to show that recognizing multiple species amongst the dog, including the Dingo and New Guinea Singing Dog, was necessary taxonomically, and (2) the principle of nomenclatural priority (the name familiaris Linnaeus, 1758, antedates dingo Meyer, 1793). Overwhelming current evidence from archaeology and genomics indicates that the Dingo is of recent origin in Australia and shares immediate ancestry with other domestic dogs as evidenced by patterns of genetic and morphological variation. Accordingly, for Smith et al.  (2019) to recognise Canis dingo as a distinct species, the onus was on them to overturn current interpretations of available archaeological, genomic, and morphological datasets and instead show that Dingoes have a deeply divergent evolutionary history that distinguishes them from other named forms of Canis (including C. lupus and its domesticated version, C. familiaris). A recent paper by Koepfli et al.  (2015) demonstrates exactly how this can be done in a compelling way within the genus Canis-by demonstrating deep evolutionary divergence between taxa, on the order of hundreds of thousands of years, using data from multiple genetic systems. Smith et al.  (2019) have not done this; instead they have misrepresented the content and conclusions of Jackson et al.  (2017), and contributed extraneous arguments that are not relevant to taxonomic decisions. Here we dissect Smith et al.  (2019), identifying misrepresentations, to show that ecological, behavioural and morphological evidence is insufficient to recognise Dingoes as a separate species from other domestic dogs. We reiterate: the correct binomial name for the taxon derived from Gray Wolves (C. lupus) by passive and active domestication, including Dingoes and other domestic dogs, is Canis familiaris. We are strongly sympathetic to arguments about the historical, ecological, cultural, or other significance of the Dingo, but these are issues that will have to be considered outside of the more narrow scope of taxonomy and nomenclature.

Novel antibody probes for the characterization of endosialin/TEM-1

Endosialin (Tumor Endothelial Marker-1 (TEM-1), CD248) is primarily expressed on pericytes of tumor-associated microvasculature, tumor-associated stromal cells and directly on tumors of mesenchymal origin, including sarcoma and melanoma. While the function of endosialin/TEM-1 is incompletely understood, studies have suggested a role in supporting tumor growth and invasion thus making it an attractive therapeutic target. In an effort to further understand its role in cancer, we previously developed a humanized anti-endosialin/TEM-1 monoclonal antibody (mAb), called ontuxizumab (MORAb-004) for testing in preclinical and clinical studies. We herein report on the generation of an extensive panel of recombinant endosialin/TEM-1 protein extracellular domain (ECD) fragments and novel mAbs against ECD motifs. The domain-specific epitopes were mapped against ECD sub-domains to identify those that can detect distinct structural motifs and can be potentially formatted as probes suitable for diagnostic and functional studies. A number of mAbS were shown to cross-react with the murine and human protein, potentially allowing their use in human animal models and corresponding clinical trials. In addition, pairing of several mAbs supported their use in immunoassays that can detect soluble endosialin/TEM-1 (sEND) in the serum of healthy subjects and cancer patients.

Gene expression analyses support fallopian tube epithelium as the cell of origin of epithelial ovarian cancer

Folate receptor alpha (FOLR1/FRA) is reported to be overexpressed in epithelial ovarian cancers (EOC), especially the serous histotype. Further, while dysregulation of the folate-dependent 1-carbon cycle has been implicated in tumorogenesis, little is known relative to the potential mechanism of action of FOLR1 expression in these processes. We therefore investigated the expression of FOLR1, other folate receptors, and genes within the 1-carbon cycle in samples of EOC, normal ovary and fallopian tube on a custom TaqMan Low Density Array. Also included on this array were known markers of EOC such as MSLN, MUC16 and HE4. While few differences were observed in the expression profiles of genes in the 1-carbon cycle, genes previously considered to be overexpressed in EOC (e.g., FOLR1, MSLN, MUC16 and HE4) showed significantly increased expression when comparing EOC to normal ovary. However, when the comparator was changed to normal fallopian tube, these differences were abolished, supporting the hypothesis that EOC derives from fallopian fimbriae and, further, that markers previously considered to be upregulated or overexpressed in EOC are most likely not of ovarian origin, but fallopian in derivation. Our findings therefore support the hypothesis that the cell of origin of EOC is tubal epithelium.

An accurate assessment of habitat loss and current threats to the mahogany glider (Petaurus gracilis)

Despite the establishment of legislation to protect the remaining habitat of the endangered mahogany glider (Petaurus gracilis) there is an urgent need to understand where habitat remains and how it should be managed. Regional ecosystem mapping was used to identify the true extent of habitat loss from clearing and the extent of habitat degradation due to the transition to rainforest (where rainforest develops within in a sclerophyll community) and sclerophyll thickening (where saplings of local sclerophyllous species form a thick secondary tree layer). The total area of habitat available to mahogany gliders decreased by 49%, from 276 880 to 141 122 ha, as a result of clearing of vegetation for agriculture and other human activities. Of the habitat remaining, 51 870 ha was the most structurally complex and floristically diverse habitat type ‘Mixed Open Forest’, 55 760 ha was the more open and less diverse ‘Mixed Woodland’, 29 988 ha consisted of mainly single-canopy-species vegetation ‘Monotypic Stands’ and 3504 ha was classed as having only Emergent trees (trees emergent from a rainforest canopy) suitable for the mahogany glider. The loss of habitat occurred mostly on freehold land where it has decreased from 129 435 ha to 26 852 ha. Within the remaining Mixed Open Forest habitat, 45% is considered to have decreasing habitat suitability for the mahogany glider as a result of sclerophyll thickening or transition to rainforest, as is 26% of Mixed Woodland habitat, 33% of Monotypic Stands habitat and 8% of Emergent habitat. The impact of a large reduction in habitat area and decreasing habitat suitability has been compounded by habitat fragmentation. The remaining habitat must be actively managed to ensure its usefulness to the mahogany glider by implementing an appropriate fire regime and ensuring that habitat connectivity is maintained or increased.

Mitochondrial dysfunction in NnaD mutant flies and Purkinje cell degeneration mice reveals a role for Nna proteins in neuronal bioenergetics

The Purkinje cell degeneration (pcd) mouse is a recessive model of neurodegeneration, involving cerebellum and retina. Purkinje cell death in pcd is dramatic, as >99% of Purkinje neurons are lost in 3 weeks. Loss of function of Nna1 causes pcd, and Nna1 is a highly conserved zinc carboxypeptidase. To determine the basis of pcd, we implemented a two-pronged approach, combining characterization of loss-of-function phenotypes of the Drosophila Nna1 ortholog (NnaD) with proteomics analysis of pcd mice. Reduced NnaD function yielded larval lethality, with survivors displaying phenotypes that mirror disease in pcd. Quantitative proteomics revealed expression alterations for glycolytic and oxidative phosphorylation enzymes. Nna proteins localize to mitochondria, loss of NnaD/Nna1 produces mitochondrial abnormalities, and pcd mice display altered proteolytic processing of Nna1 interacting proteins. Our studies indicate that Nna1 loss of function results in altered bioenergetics and mitochondrial dysfunction.

CD45RO: A Marker for BCR-mediated Selection

We previously showed that IgH sequence alone minimally influenced germinal centre (GC) B-cell survival fate. As end-stage effector B cells are typically more mutated than founder GC B cells, we worked to develop an assay that would enrich for populations of GC B cells with progressively increasing numbers of somatic mutations, which could potentially be used as an indicator of positive selection. We targeted CD45 as it has been shown to influence activation-induced cytidine deaminase (AID) expression. In this study, anti-CD77 and anti-CD45RO (RO) were used to subdivide CD19(+)IgD(-)CD38(+)CD77(+) centroblasts (CB) and CD19(+)IgD(-)CD38(+)CD77(-) centrocytes (CC) into three contiguous RO fractions (RO(-), RO(+/-) and RO(+)) and assessed whether mutation frequency and characteristics associated with selection varied with respect to increasing RO expression. Here, we show that the average number of mutations per IgV(H)4 transcript increased concordantly with RO for CC, but not for CB. CC also exhibited an RO-associated increase in replacement mutations. Comparative analysis of clonally related sequences revealed that increased mutations were not due to the exclusive persistence of surface RO on highly mutated cells. RO-expressing CC and CB pools showed increased signs of activation (CD69(+)) and were enriched for surface Ig(+) cells. BCR-crosslinking induced a significant increase in surface RO on total tonsillar and GC B cells, which collectively suggests that the RO-associated increase in mutations is attributable, at least in part, to the cycling of cells that may have recently undergone BCR-mediated selection, or are potentially in developmental transition between CC and CB stages.

CD45RO enriches for activated, highly mutated human germinal center B cells

To date, there is no consensus regarding the influence of different CD45 isoforms during peripheral B-cell development. Examining correlations between surface CD45RO expression and various physiologic processes ongoing during the germinal center (GC) reaction, we hypothesized that GC B cells, like T cells, that up-regulate surface RO should progressively acquire phenotypes commonly associated with activated, differentiating lymphocytes. GC B cells (IgD(-)CD38(+)) were subdivided into 3 surface CD45RO fractions: RO(-), RO(+/-), and RO(+). We show here that the average number of mutations per IgV(H) transcript increased in direct correlation with surface RO levels. Conjunctional use of RO and CD69 further delineated low/moderately and highly mutated fractions. Activation-induced cytidine deaminase (AID) mRNA was slightly reduced among RO(+) GC B cells, suggesting that higher mutation averages are unlikely due to elevated somatic mutation activity. Instead, RO(+) GC B cells were negative for Annexin V, comprised mostly (93%) of CD77(-) centrocytes, and were enriched for CD69(+) cells. Collectively, RO(+) GC B cells occupy what seems to be a specialized niche comprised mostly of centrocytes that may be in transition between activation states. These findings are among the first to sort GC B cells into populations enriched for live mutated cells solely using a single extracellular marker.

The bovine antibody repertoire

Cattle are able to produce a full range of Ig classes including the long-elusive IgD through rearrangement of their germline genes. Several IgL groupings have been reported but as in several other livestock species (e.g. sheep, rabbits, chickens), rearrangement per se fails to generate significant IgH diversity. This is largely because of the modest number of bovine VH segments that participate in rearrangement and their conserved sequences. Perhaps in compensation, bovine Ig heavy chains carry CDR3 sequences of exceptional length. Processes that operate post-rearrangement to generate diversity remain ill defined as are the location, timing and triggers to these events. Reagents are needed to understand better the maturation of B lymphocytes, their responses to antigens and cytokines, and to provide standards for the quantitation of Ig responses in cattle; recombinant methods may help meet this need as Ab engineering technologies become more widely used.

A SCA7 CAG/CTG repeat expansion is stable in Drosophila melanogaster despite modulation of genomic context and gene dosage

CAG and CTG repeat expansions are the cause of at least a dozen inherited neurological disorders. In these so-called "dynamic mutation" diseases, the expanded repeats display dramatic genetic instability, changing in size when transmitted through the germline and within somatic tissues. As the molecular basis of the repeat instability process remains poorly understood, modeling of repeat instability in model organisms has provided some insights into potentially involved factors, implicating especially replication and repair pathways. Studies in mice have also shown that the genomic context of the repeat sequence is required for CAG/CTG repeat instability in the case of spinocerebellar ataxia type 7 (SCA7), one of the most unstable of all CAG/CTG repeat disease loci. While most studies of repeat instability have taken a candidate gene approach, unbiased screens for factors involved in trinucleotide repeat instability have been lacking. We therefore attempted to use Drosophila melanogaster to model expanded CAG repeat instability by creating transgenic flies carrying trinucleotide repeat expansions, deriving flies with SCA7 CAG90 repeats in cDNA and genomic context. We found that SCA7 CAG90 repeats are stable in Drosophila, regardless of context. To screen for genes whose reduced function might destabilize expanded CAG repeat tracts in Drosophila, we crossed the SCA7 CAG90 repeat flies with various deficiency stocks, including lines lacking genes encoding the orthologues of flap endonuclease-1, PCNA, and MutS. In all cases, perfect repeat stability was preserved, suggesting that Drosophila may not be a suitable system for determining the molecular basis of SCA7 CAG repeat instability.

IgH V-Region Sequence Does Not Predict the Survival Fate of Human Germinal Center B Cells

Germinal center (GC) B cell survival fate is governed in part by the outcome of successful/failed BCR-mediated interactions with accessory cells. However, the extent to which the BCR primary sequence influences such interactions is not fully understood. Over 1000 IgV(H)4 family cDNAs were sequenced from living (annexin V(-)) and apoptotic (annexin V(+) or from within tingible body macrophages) GC B cell fractions from seven tonsils. Results surprisingly demonstrate that living and dying GC B cells do not significantly differ in IgV(H), D, or J(H) gene segment use; HCDR3 length or positive charge; or mutation frequency. Additionally, equivalent IgH cDNA sequences were identified in both fractions, suggesting that BCR sequence alone is an unreliable predictor of GC B cell survival.

Monsieur Jules Verreaux and the platypus, Ornithorhynchus anatinus: comments on a naturaliste voyageur

During his 15 month sojourn in Tasmania, Monsieur Jules Verreaux devoted most of his efforts to studying the platypus, including making observations in the field. While some of his observations were accurate and original, others were at odds with those of later naturalists and current scientific findings. Like most other 19th century expatriate naturalists from the Northern Hemisphere, Verreaux failed to determine that the species laid eggs but he described some intriguing attributes which remain controversial and/or unsubstantiated by the work of more recent naturalists and scientists. Perhaps the most controversial was that the newly emerged young prod the mammary areas of the female and take the exuded milk from the surface of the water. An annotated summary of Verreaux's findings is presented, along with the full text of his work in French and a translation of this text into modern English.

Human immunoglobulin selection associated with class switch and possible tolerogenic origins for C delta class-switched B cells

Current paradigms of peripheral B cell selection suggest that autoreactive B cells are controlled by clonal deletion, anergy, and developmental arrest. We report that changes to the human antibody repertoire likely resulting from these mechanisms both for a well-characterized autoreactivity from antibodies encoded by the V(H)4-34 gene and for other hallmarks of an autoreactive repertoire are apparent mainly for class-switched B cells and not for IgM germinal center, IgM memory, or IgM plasma cells. Other possible indicators of autoreactivity found selected with immunoglobulin class include J(H)6 gene segment usage, increased frequency of B cells with long third hypervariable regions, and distal J(kappa) gene segment bias. Of particular interest is the finding that B cells with these same characteristics are selected into the lineage of B cells that have undergone the unusual class switch from constant region C mu to C delta (C delta-CS). The C delta-CS population also displays an increased frequency of charged amino acids localized to the complementarity-determining regions, further suggesting autoreactivity, and evidence is presented that these B cells had undergone extensive receptor editing. Thus, the C delta-CS lineage may be a "sink" for B cells harboring autoreactive specificities in normal humans. A model for a new tolerizing mechanism that could account for the C delta-CS lineage is presented.

A Drosophila homolog of the polyglutamine disease gene SCA2 is a dosage-sensitive regulator of actin filament formation

Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disorder caused by the expansion of a CAG repeat encoding a polyglutamine tract in ataxin-2, the SCA2 gene product. The normal cellular function of ataxin-2 and the mechanism by which polyglutamine expansion of ataxin-2 causes neurodegeneration remain unknown. In this study we have used genetic and molecular approaches to investigate the function of a Drosophila homolog of the SCA2 gene (Datx2). Like human ataxin-2, Datx2 is found throughout development in a variety of tissue types and localizes to the cytoplasm. Mutations that reduce Datx2 activity or transgenic overexpression of Datx2 result in female sterility, aberrant sensory bristle morphology, loss or degeneration of tissues, and lethality. These phenotypes appear to result from actin filament formation defects occurring downstream of actin synthesis. Further studies demonstrate that Datx2 does not assemble with actin filaments, suggesting that the role of Datx2 in actin filament formation is indirect. These results indicate that Datx2 is a dosage-sensitive regulator of actin filament formation. Given that loss of cytoskeleton-dependent dendritic structure defines an early event in SCA2 pathogenesis, our findings suggest the possibility that dysregulation of actin cytoskeletal structure resulting from altered ataxin-2 activity is responsible for neurodegeneration in SCA2.

An A-kinase anchoring protein is required for Protein kinase A regulatory subunit localization and morphology of actin structures during oogenesis inDrosophila

Protein kinase A (PKA) holoenzyme is anchored to specific subcellular regions by interactions between regulatory subunits (Pka-R) and A-kinase anchoring proteins (AKAPs). We examine the functional importance of PKA anchoring during Drosophila oogenesis by analyzing membrane integrity and actin structures in mutants with disruptions in Akap200, an AKAP. In wild-type ovaries, Pka-RII and Akap200 localized to membranes and to the outer rim of ring canals, actin-rich structures that connect germline cells. In Akap200 mutant ovaries, Pka-RII membrane localization decreased, leading to a destabilization of membrane structures and the formation of binucleate nurse cells. Defects in membrane integrity could be mimicked by expressing a constitutively active PKA catalytic subunit (Pka-C) throughout germline cells. Unexpectedly, nurse cells in Akap200 mutant ovaries also had enlarged, thin ring canals. In contrast, overexpressing Akap200 in the germline resulted in thicker, smaller ring canals. To investigate the role of Akap200 in regulating ring canal growth, we examined genetic interactions with other genes that are known to regulate ring canal morphology. Akap200 mutations suppressed the small ring canal phenotype produced by Src64B mutants, linking Akap200 with the non-receptor tyrosine kinase pathway. Together, these results provide the first evidence that PKA localization is required for morphogenesis of actin structures in an intact organism.

Drosophila rhino encodes a female-specific chromo-domain protein that affects chromosome structure and egg polarity

Here we describe our analyses of Rhino, a novel member of the Heterochromatin Protein 1(HP1) subfamily of chromo box proteins. rhino (rhi) is expressed only in females and chiefly in the germline, thus providing a new tool to dissect the role of chromo-domain proteins in development. Mutations in rhi disrupt eggshell and embryonic patterning and arrest nurse cell nuclei during a stage-specific reorganization of their polyploid chromosomes, a mitotic-like state called the "five-blob" stage. These visible alterations in chromosome structure do not affect polarity by altering transcription of key patterning genes. Expression levels of gurken (grk), oskar (osk), bicoid (bcd), and decapentaplegic (dpp) transcripts are normal, with a slight delay in the appearance of bcd and dpp mRNAs. Mislocalization of grk and osk transcripts, however, suggests a defect in the microtubule reorganization that occurs during the middle stages of oogenesis and determines axial polarity. This defect likely results from aberrant Grk/Egfr signaling at earlier stages, since rhi mutations delay synthesis of Grk protein in germaria and early egg chambers. In addition, Grk protein accumulates in large, actin-caged vesicles near the endoplasmic reticulum of stages 6-10 egg chambers. We propose two hypotheses to explain these results. First, Rhi may play dual roles in oogenesis, independently regulating chromosome compaction in nurse cells at the end of the unique endoreplication cycle 5 and repressing transcription of genes that inhibit Grk synthesis. Thus, loss-of-function mutations arrest nurse cell chromosome reorganization at the five-blob stage and delay production or processing of Grk protein, leading to axial patterning defects. Second, Rhi may regulate chromosome compaction in both nurse cells and oocyte. Loss-of-function mutations block nurse cell nuclear transitions at the five-blob stage and activate checkpoint controls in the oocyte that arrest Grk synthesis and/or inhibit cytoskeletal functions. These functions may involve direct binding of Rhi to chromosomes or may involve indirect effects on pathways controlling these processes.

Local control of T3N0 glottic carcinoma by 60 Gy given over five weeks in 2.4 Gy daily fractions. One more point on the biological effective dose (BED) curve

Seventy patients with T3N0 glottic cancer who received a total dose of 60 Gy in twenty-five 2.4 Gy daily fractions over 5 weeks had an initial post radiation primary recurrence free rate of 65% at 5 years. This provides one more point for the dose response for T3 glottic cancer Radiother Oncol (1999) 15.

Elevated serum and bronchoalveolar lavage fluid levels of interleukin 8 and granulocyte colony-stimulating factor associated with the acute chest syndrome in patients with sickle cell disease

The role of cytokines in the development of acute chest syndrome (ACS) in patients with sickle cell disease (SCD) was studied. Serum interleukin 8 (IL-8) levels were elevated in 14 episodes and undetectable in six out of 20 episodes of ACS in 19 patients with SCD. In contrast, IL-8 levels were undetectable in the sera of 29 control patients with SCD studied during routine clinic visits or hospitalization for vaso-occlusive crises. The differences in mean IL-8 levels and the proportion of patients with detectable levels between the two groups were highly significant (P < 0.0001 and 0.04 respectively). The mean IL-8 level in bronchial fluid samples from children with ACS was also significantly higher than that in sickle cell patients undergoing elective surgery (5500 +/- 1400 pg/ml vs. 1900 +/- 470 pg/ml, P = 0.03). Granulocyte colony-stimulating factor (G-CSF) (2000 +/- 1700 pg/ml) was present in five out of six samples of bronchial fluid, but not serum, from children with ACS. All but one of the patients with ACS studied were negative for the Duffy red cell antigen, which is a receptor that binds and inactivates IL-8 and other chemokines. These findings suggest that IL-8 and G-CSF may play a role in the development of the ACS and the complications associated with it.

Bone marrow transplantation versus periodic prophylactic blood transfusion in sickle cell patients at high risk of ischemic stroke: a decision analysis

Measurement of cerebral blood velocity (CBV) by transcranial Doppler has been used to identify patients with sickle cell disease (SCD) who are at high risk of ischemic stroke. This study examines outcomes of bone marrow transplantation (BMT) and periodic blood transfusion (PBT) as a basis for making treatment recommendations for patients who have elevated CBV and no other indications for BMT. Decision analysis was used to compare the number of quality-adjusted life years (QALYs) experienced by a population of patients with SCD at high risk for stroke who were treated with PBT or BMT. Markov models were constructed to represent the clinical course of patients with SCD who were treated with PBT or BMT. Medical literature and expert opinion provided risks of stroke and death for different disease states, estimates of transition probabilities from one clinical state to another, and quality of life. An intention-to-treat analysis and an analysis of treatment received were both performed on hypothetical cohorts of 100 000 patients. Patients with SCD who were managed with a strategy of intending to provide BMT could expect 16.0 QALYs, compared with 15.7 QALYs for a strategy of intending to provide PBT; however, the variation around these estimates was large. In the treatment received analysis, patients compliant with PBT therapy and iron chelation could expect the best outcomes (19.2 QALYs). From a policy perspective, neither BMT nor PBT can be considered the "best" treatment for children with SCD who have abnormal CBV. Abnormal CBV should not be the only criterion for selecting patients with sickle cell for BMT.

Doxazosin inhibits retinoblastoma protein phosphorylation and G(1)-->S transition in human coronary smooth muscle cells

Previous studies have demonstrated that the alpha(1)-adrenergic receptor antagonist doxazosin (Dox) inhibits multiple mitogenic signaling pathways in human vascular smooth muscle cells. This broad antiproliferative activity of Dox occurs through a novel mechanism unrelated to its blocking the alpha(1)-adrenergic receptor. Flow cytometry demonstrated that Dox prevents mitogen-induced G(1)-->S progression of human coronary artery smooth muscle cells (CASMCs) in a dose-dependent manner, with a maximal reduction of S-phase transition by 88+/-10.5% in 20 ng/mL platelet-derived growth factor and 1 micromol/L insulin (P+I)-stimulated cells (P<0.01 for 10 micromol/L Dox versus P+I alone) and 52+/-18.7% for 10% FBS-induced mitogenesis (P<0.05 for 10 micromol/L Dox versus 10% FBS alone). Inhibition of G(1) exit by Dox was accompanied by a significant blockade of retinoblastoma protein (Rb) phosphorylation. Hypophosphorylated Rb sequesters the E2F transcription factor, leading to G(1) arrest. Adenoviral overexpression of E2F-1 stimulated quiescent CASMCs to progress through G(1) and enter the S phase. E2F-mediated G(1) exit was not affected by Dox, suggesting that it targets events upstream from Rb hyperphosphorylation. Downregulation of the cyclin-dependent kinase inhibitory protein p27 is important for maximal activation of G(1) cyclin/cyclin-dependent kinase holoenzymes to overcome the cell cycle inhibitory activity of Rb. In Western blot analysis, p27 levels decreased after mitogenic stimulation (after P+I, 43+/-1.8% of quiescent cells [P<0.01 versus quiescent cells]; after 10% FBS, 55+/-7.7% of quiescent cells [P<0. 05 versus quiescent cells]), whereas the addition of Dox (10 micromol/L) markedly attenuated its downregulation (after P+I, 90+/-8.3% of quiescent cells [P<0.05 versus P+I alone]; after 10% FBS, 78+/-8.3% of quiescent cells [P<0.05 versus 10% FBS alone]). Furthermore, Dox inhibited cyclin A expression, an E2F regulated gene that is essential for cell cycle progression into the S phase. The present study demonstrates that Dox inhibits CASMC proliferation by blocking cell cycle progression from the G(0)/G(1) phase to the S phase. This G(1)-->S blockade likely results from an inhibition of mitogen-induced Rb hyperphosphorylation through prevention of p27 downregulation.

Peroxisome proliferator-activated receptor activators modulate the osteoblastic maturation of MC3T3-E1 preosteoblasts

The reduced bone mineral density (BMD) observed in osteoporosis results, in part, from reduced activity of bone-forming osteoblasts. We examined the effect of peroxisome proliferator-activated receptor (PPAR) activators on MC3T3-E1 preosteoblast maturation. Activators of PPARalpha, delta and gamma induced alkaline phosphatase activity, matrix calcification and the expression of osteoblast genes as determined by reverse transcriptase-polymerase chain reaction. However, at relatively high concentrations of the specific PPARgamma ligands, ciglitazone and troglitazone, maturation was inhibited. PPARalpha, delta and gamma1 were expressed in MC3T3-E1 cells. PPARgamma1 mRNA and protein levels were induced early during osteoblastic maturation. We speculate that endogenous and pharmacological PPAR activators may affect BMD by modulating osteoblastic maturation.

Effect of time interval between breast-conserving surgery and radiation therapy on ipsilateral breast recurrence

PURPOSE

To examine the effect of the time interval (interval) between breast-conserving surgery (BCS) and the start of radiation therapy (RT) on the subsequent risk of ipsilateral breast cancer recurrence (IBR).

METHODS AND MATERIALS

We reviewed interval and a number of prognostic and treatment factors among 1,962 women treated with BCS and RT for invasive breast cancer diagnosed between January 1, 1989 and December 31, 1993 in British Columbia, Canada. Subjects were female, less than 90 years old at diagnosis, not treated with chemotherapy, not stage T4 or M1, and had survived more than 30 days from diagnosis. The cumulative incidence of IBR was estimated in four interval groups: 0-5, 6-8, 9-12, and 13+ weeks. Only 23 women had an interval of greater than 20 weeks between BCS and start of RT. To assess whether an imbalance of prognostic and treatment factors could be obscuring real differences between the interval groups, Cox proportional hazards regression analyses were conducted.

RESULTS

Median follow-up was 71 months. The crude incidence of IBR for the entire sample was 3.9%. The cumulative incidence of IBR in the 6-8, 9-12, and 13+ week groups was not statistically significantly different from the cumulative incidence of IBR in the 0-5 week group. Multivariate analyses demonstrated that patients not using tamoxifen p = 0.027) and those with grade 3 histology (p = 0.003) were more likely to recur in the breast. Interval between BCS and RT was not a statistically significant predictor of breast recurrence when entered into a model incorporating tamoxifen use and tumor grade (0-5 vs. 6-8 weeks, p = 0.872; 0-5 vs. 9-12 weeks, p = 0.665; 0-5 vs. 13+ weeks, p = 0.573).

CONCLUSIONS

We found no univariate or multivariate difference in ipsilateral breast cancer recurrence between intervals of 0 to 20 weeks from breast conserving surgery to start of radiation therapy, in a population-based, low risk group of women not receiving adjuvant chemotherapy, after controlling for other factors important in predicting ipsilateral breast cancer recurrence.

Home-range and den use of the mahogany glider, Petaurus gracilis

The home-range of the mahogany glider was estimated, and its social behaviour examined, by following radio-collared animals over a two-year period within an area of continuous habitat and an adjacent area of fragmented habitat. The average home range within the continuous habitat was 19.25 ha for males and 20.34 ha for females, with male and female pairs occupying a combined area of 23.15 ha. In contrast, the average home range in the fragmented habitat was 11.05 ha for males and 6.80 ha for females, with a combined home-range of male and female pairs being 11.60 ha. The average overlap of the home ranges of paired males and females was 85.9%, compared with approximately 11% for non-paired individuals, which suggests that mahogany gliders are socially monogamous. For a total of 46 nights on which gliders were considered to behave normally for the entire night, the average foraging distance was 1506 m (range 590–3420 m) with no significant difference between males and females in either the continuous or fragmented habitat. There was, however, a significant difference in the distance individuals travelled during different times of the year, with longer distances being travelled during late dry season/wet season and shorter distances during the early to mid dry season. Mahogany gliders also travelled further when there was a high availability of nectar and pollen than when there was lower availability. A total of 83 dens (tree hollows) were recorded for the mahogany glider, with the poplar gum, Eucalyptus platyphylla, forest red gum, Eucalyptus tereticornis, and Clarkson's bloodwood, Corymbia clarksoniana, being most used.

Habitat relationships of the mahogany glider, Petaurus gracilis, and the sugar glider, Petaurus breviceps

Trapping data of the mahogany glider, Petaurus gracilis, and the sugar glider, Petaurus breviceps, in sympatry, in north Queensland, were analysed with vegetation variables to determine the habitat relationships of these two species. The study area contained a trapping grid (80 traps) within an area of continuous forest and trapping transects within an adjacent area of fragmented forest (44 traps). The mahogany glider was trapped more often at 43 of the 124 locations (38 in the continuous and 5 in the fragmented forest), with the sugar glider dominant at 46 locations (18 in the continuous forest and 28 in the fragmented forest). The remaining 27 trap locations where gliders were caught did not favour either species. Eight trap locations within riparian rainforest had no captures of either species. The presence of mahogany gliders was significantly correlated with the presence of Corymbia clarksoniana, Eucalyptus platyphylla, the absence of Corymbia intermedia and Acacia mangium, and a small mid and upper canopy cover. In contrast, the presence of sugar gliders was most correlated with a large number of stems. When the presence of the mahogany glider was compared with that of the sugar glider with respect to various habitat variables for the entire study area, the mahogany glider was most associated with the presence of C. clarksoniana, Eucalyptus pellita, Lophostemon suaveolens, Melaleuca dealbata and a reduced lower and upper canopy. In contrast, the sugar glider was most associated with C. intermedia, A. mangium, a large number of potential food species, rainforest species and a dense mid and upper canopy cover.

Population dynamics and life history of the mahogany glider, Petaurus gracilis, and the sugar glider, Petaurus breviceps, in north Queensland

Mahogany gliders, Petaurus gracilis, and sugar gliders, Petaurus breviceps, were trapped in an area of open woodland in north Queensland between 1994 and 1996 to examine their population ecology and life history. This study area contained two smaller areas, one consisting of continuous habitat and the other an area of fragmented habitat adjacent to the continuous habitat. Within the continuous area, the mahogany glider had an average density of 0.24 ha–1 whereas the sugar glider had an average density of 0.27 ha–1. In contrast, the density of mahogany gliders in the fragmented habitat averaged only 0.16 ha–1 whereas the density of sugar gliders was higher, at 0.46 ha–1. Both the mahogany glider and the sugar glider showed sexual dimorphism in their weight, head length and head width. The average body weight of both species fluctuated throughout the year with no consistent pattern. The mahogany glider showed a distinct breeding season, with births being recorded between April and October, whereas the sugar glider showed no pattern, with births being recorded during all months except February and April. During the study, all adult females of both species were observed to have bred, with an average litter size of 1.55 and a natality rate of 2.09 for the mahogany glider, and an average litter size of 1.83 and a natality rate of 2.14 for the sugar glider. The sugar glider was able to raise two litters of young within a single year whereas a second litter was raised by the mahogany glider only if the first litter was lost.

The comet assay in clinical practice

The comet assay is a single-cell gel electrophoresis technique that measures DNA damage in individual cells. Since radiation produces 3-4 times more DNA damage in well-oxygenated cells compared with hypoxic cells, this assay can quantify the fraction of radiation-resistant hypoxic cells found in many solid tumours. This paper summarizes our results with 73 accessible metastatic tumours irradiated with palliative intent. Hypoxic fractions ranged from 0.0 to 0.67 with a mean of 0.15; 62% of these advanced tumours showed a hypoxic fraction > 0.05. Comparisons between two sequential aspirates in 33 tumours gave a slope of 0.92 (r2 = 0.88), suggesting that a single aspirate is generally representative of the tumour. A limitation, however, is that the hypoxic fraction could not be measured in clinical samples given a conventional dose of 2 Gy.

Atherogenic diet and minimally oxidized low density lipoprotein inhibit osteogenic and promote adipogenic differentiation of marrow stromal cells

In osteoporosis, the bone marrow stroma osteogenic cell population declines and adipocyte numbers increase. We recently showed that oxidized lipids inhibit differentiation of preosteoblasts. In this report, we assess the effect of minimally oxidized low density lipoprotein (MM-LDL) on osteoblastic differentiation of murine marrow stromal cells, M2-10B4. MM-LDL, but not native LDL, inhibited stromal cell osteoblastic differentiation as demonstrated by inhibition of alkaline phosphatase activity, collagen I processing, and mineralization, through a mitogen-activated protein kinase-dependent pathway. In addition, marrow stromal cells from C57BL/6 mice fed a high fat, atherogenic diet failed to undergo osteogenic differentiation in vitro. The ability of MM-LDL to regulate adipogenesis was also assessed. Treatment of M2-10B4 as well as 3T3-L1 preadipocytes with MM-LDL, but not native LDL, promoted adipogenic differentiation in the presence of peroxisome proliferator-activated receptor (PPAR) gamma agonist thiazolidinediones, BRL49653 and ciglitizone. Based on promoter-reporter construct experiments, MM-LDL may be acting in part through activating PPARalpha. These observations suggest that LDL oxidation products promote osteoporotic loss of bone by directing progenitor marrow stromal cells to undergo adipogenic instead of osteogenic differentiation. These data lend support to the "lipid hypothesis of osteoporosis."

Soma-to-germline interactions during Drosophila oogenesis are influenced by dose-sensitive interactions between cut and the genes cappuccino, ovarian tumor and agnostic

The cut gene of Drosophila melanogaster encodes a homeodomain protein that regulates a soma-to-germline signaling pathway required for proper morphology of germline cells during oogenesis. cut is required solely in somatic follicle cells, and when cut function is disrupted, membranes separating adjacent nurse cells break down and the structural integrity of the actin cytoskeleton is compromised. To understand the mechanism by which cut expression influences germline cell morphology, we determined whether binucleate cells form by defective cytokinesis or by fusion of adjacent cells. Egg chambers produced by cut, cappuccino, and chickadee mutants contained binucleate cells in which ring canal remnants stained with antibodies against Hu-li tai shao and Kelch, two proteins that are added to ring canals after cytokinesis is complete. In addition, defects in egg chamber morphology were observed only in middle to late stages of oogenesis, suggesting that germline cell cytokineses were normal in these mutants. cut exhibited dose-sensitive genetic interactions with cappuccino but not with chickadee or other genes that regulate cytoskeletal function, including armadillo, spaghetti squash, quail, spire, Src64B, and Tec29A. Genomic regions containing genes that cooperate with cut were identified by performing a second-site noncomplementing screen using a collection of chromosomal deficiencies. Sixteen regions that interact with cut during oogenesis and eight regions that interact during the development of other tissues were identified. Genetic interactions between cut and the ovarian tumor gene were identified as a result of the screen. In addition, the gene agnostic was found to be required during oogenesis, and genetic interactions between cut and agnostic were revealed. These results demonstrate that a signaling pathway regulating the morphology of germline cells is sensitive to genetic doses of cut and the genes cappuccino, ovarian tumor, and agnostic. Since these genes regulate cytoskeletal function and cAMP metabolism, the cut-mediated pathway functionally links these elements to preserve the cytoarchitecture of the germline cells.

Peroxisome proliferator-activated receptor activators target human endothelial cells to inhibit leukocyte-endothelial cell interaction

An early event in acute and chronic inflammation and associated diseases such as atherosclerosis and rheumatoid arthritis is the induced expression of specific adhesion molecules on the surface of endothelial cells (ECs), which subsequently bind leukocytes. Peroxisome proliferator-activated receptors (PPARs), members of the nuclear receptor superfamily of transcription factors, are activated by fatty acid metabolites, peroxisome proliferators, and thiazolidinediones and are now recognized as important mediators in the inflammatory response. Whether PPAR activators influence the inflammatory responses of ECs is unknown. We show that the PPAR activators 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), Wyeth 14643, ciglitazone, and troglitazone, but not BRL 49653, partially inhibit the induced expression of vascular cell adhesion molecule-1 (VCAM-1), as measured by ELISA, and monocyte binding to human aortic endothelial cells (HAECs) activated by phorbol 12-myristate 13-acetate (PMA) or lipopolysaccharide. The "natural" PPAR activator 15d-PGJ(2) had the greatest potency and was the only tested molecule capable of partially inhibiting the induced expression of E-selectin and neutrophil-like HL60 cell binding to PMA-activated HAECs. Intracellular adhesion molecule-1 induction by PMA was unaffected by any of the molecules tested. Both PPAR-alpha and PPAR-gamma mRNAs were detected in HAECs by using reverse transcription-polymerase chain reaction and a ribonuclease protection assay; however, we have yet to determine which, if any, of the PPARs are mediating this process. These results suggest that certain PPAR activators may help limit chronic inflammation mediated by VCAM-1 and monocytes without affecting acute inflammation mediated by E-selectin and neutrophil binding.

The use of static mass spectrometry to determine the combined stable isotopic composition of small samples of atmospheric methane

Global budgets of atmospheric trace gases are increasingly being constrained by means of stable isotope measurements. Published analytical techniques for studying the parallel stable isotopic composition of methane (delta(13)C and deltaD) require prohibitively large quantities of methane for analysis, making them unsuitable for studies where sample size is small, e.g. soil methane fluxes. A highly sensitive static mass spectrometer has been developed which uniquely uses CH(4) as the analyte. The method requires only 8 ng of CH(4) for analysis (<10 mL ambient air), making replicated measurements of the isotopic composition of CH(4) in small samples feasible for the first time. This paper provides the first detailed description of the instrumentation and the analytical technique. The technique has been used to analyse small samples of air collected in Snowdonia over 21 months. The combined stable isotopic composition (delta(17)M) ranged from 29.5 to 35.5 per thousand, with an average value of 32.2 per thousand, and was strongly correlated with wind direction (p <0.01, r(2) = 0.71). Copyright 1999 John Wiley & Sons, Ltd.

Compliance with radiation treatment guidelines in a provincial setting

Since 1979, consensus guidelines have been produced for radiation treatment practice in British Columbia. These guidelines have been revised, updated and circulated to all radiation oncologists periodically. A comprehensive computer database for all patients receiving radiation treatment in the province was established in 1984. Between 1985 and 1996 inclusive, 7667 prostate cancer patients and 9748 breast cancer patients received primary radical radiation treatment or adjuvant postsurgical treatment. Palliative treatments and the treatment of other disease sites are not included in this review. Compliance of these treatments with the published guidelines is reported. Over 98% of patients completed treatment as planned and, in the last 3 years, more than 90% of patients received a guideline dose to either the prostate or the breast. Compliance was less in the treatment of the regional lymph nodes in breast cancer. Practice in prostate cancer tended to precede the changes in the guidelines. This was not the case for breast cancer.

Cancer of the tonsil: the results of ipsilateral radiation treatment

BACKGROUND AND PURPOSE

The use of ipsilateral irradiation techniques to treat patients with carcinoma of the tonsil reduces the acute radiation reaction in the contralateral pharynx and late damage to the contralateral salivary tissue. However, this may also spare microscopic disease in apparently uninvolved contralateral lymph nodes. The purpose of this study was to analyse the survival and recurrence rates and sites of recurrance in a group of patients with carcinoma of the tonsil treated with ipsilateral techniques.

MATERIALS AND METHODS

Between 1975 and 1993, 271 patients with invasive squamous cell cancer of the tonsil were referred to the Vancouver Cancer Centre (VCC). One hundred and seventy-eight received ipsilateral radiation treatment. Three received surgery only, six post-operative radiation, 12 supportive treatment only and 72 bilateral radiation treatment. In the absence of bilateral neck nodes and extensive lymphodenopathy, field sizes were generally kept small to include the primary tumour and the first echelon of nodes. The most common dose was 60 Gy in 25 daily fractions in 5 weeks (2.4 Gy per day).

RESULTS AND DISCUSSION

The disease specific survival for all patients treated by radical radiation treatment was 61% at 5 years. For the 178 patients who received ipsilateral radiation treatment the overall primary tumour control rate by ipsilateral radiation treatment alone was 75% and for T1 and T2 tumours 84%. Eight (7.5%) of 101 of these patients with N0 nodes at presentation and without prior failure at the primary site, developed nodal recurrence (four within the initially radiated high dose volume). Two developed contralateral nodes, and two developed field edge nodal recurrence, one cured by surgery. In 54 patients with N1 disease, five developed nodal recurrence, two within field, two contralateral, one of whom was cured by surgery, and one at field edge. In 23 patients with N2a, N2b or N3 disease node control was achieved from radiation treatment in 11 and two more were cured by surgery. All nodal failures were within the radiated volume. Overall, 10 of the 25 patients with nodal failure were cured by subsequent surgery.

CONCLUSIONS

Ipsilateral treatment of patients with carcinoma of the tonsil gives survival results that are at least as good as those reported with bilateral treatment with fewer side effects and a very low risk of failure in the contralateral neck.