Biomedical subjects

R J Fisher

Publications and source records attributed to R J Fisher.

At least 37 records · Page 2Linked to original sources

PubMed2000

Measurement of exocytosis by amperometry in adrenal chromaffin cells: effects of clostridial neurotoxins and activation of protein kinase C on fusion pore kinetics.

We have used carbon-fibre amperometry to examine the kinetics of individual secretory granule fusion/release events in bovine adrenal chromaffin cells. Transfection with plasmids encoding the light chains of botulinum neurotoxins (BoNTs) was used to investigate the effects of cleavage of syntaxin or SNAP-25 on exocytosis. Expression of BoNT/C1 or BoNT/E inhibited the extent of exocytosis that was evoked by application of digitonin/Ca(2+) to permeabilise and stimulate single chromaffin cells. Following neurotoxin expression, the residual release events were no different from those of control cells in their magnitude and kinetics from analysis of the amperometric spikes. In contrast, activation of protein kinase C (PKC) resulted in a modification of the kinetics of single granule release events. Following phorbol ester treatment, the amperometric spikes showed a significant decrease in their total charge due to a decrease in their mean half-width with increases in the rate of the initial rise and also the fall to baseline of the spikes. These changes were prevented by pre-treatment with the PKC inhibitor bisindolylmaleimide. These results suggest that PKC regulates the rate of fusion pore expansion and also subsequent pore closure or granule retrieval. A PKC-mediated regulation of kiss-and-run fusion may, therefore, control the extent of catecholamine release from single secretory granules. The experimental approach used here may provide further information on the protein constituents and regulation of the fusion pore machinery.

Animals↗

PubMed1999

Heterogeneity of in vitro radiosensitivity in human bladder cancer cells.

Human bladder cancer is often heterogeneous containing biologically different populations. Radiotherapy plus chemotherapy is the most common treatment for invasive disease. However few studies have investigated the role of heterogeneity in determining radiosensitivity. The radiation sensitivities of a parent human bladder cancer cell line (UCRU-BL-17CL) and nine cloned cell lines derived from it were determined. These cloned cell lines were previously shown to exhibit different biological characteristics when grown in nude mice. Radiation sensitivity was determined using both MTT and clonogenic assays. The radiobiological parameters, alpha,beta, and surviving fractions at 2 Gy and 8 Gy from the linear-quadratic model, were used to assess radiation sensitivity in the statistical analyses. The nine clones differed in radiosensitivity by both assays. By MTT, but not by the clonogenic assay, their radiation sensitivities were relatively consistent within each of the three biological groups (non-tumorigenic, tumorigenic, invasive); invasive clones were more sensitive than those of the non-tumorigenic and the tumorigenic groups for all the three-test criteria. The heterogeneity exhibited by this cell line may explain some of the variations in the clinical responses seen in the radiation treatment of invasive bladder cancer.

Animals↗

PubMed1999

The effect of transfection with Botulinum neurotoxin C1 light chain on exocytosis measured in cell populations and by single-cell amperometry in PC12 cells.

We examined the effect on exocytosis in PC12 neuroendocrine cells of transient transfection with the specific endoprotease Botulinum neurotoxin C1 light chain (BoNT/C1), which cleaves syntaxin and SNAP-25. The effects of toxin expression on basal and evoked exocytosis were determined in cell population measurements and also in a single-cell transfection-amperometry assay. Co-expression of BoNT/C1 with human growth hormone (hGH) as a marker of secretory granules in transfected cells resulted in a 95% inhibition of hGH release evoked either by the purinergic agonist ATP or by depolarization with 55 mM K+. In addition, basal hGH release was also inhibited to the same extent. The high level of co-transfection efficiency revealed by this extent of inhibition was exploited in a high-resolution single-cell assay based on cell detection by expression of enhanced green fluorescent protein (EGFP) and analysis of evoked dopamine release by amperometry using a carbon fibre microelectrode. Cells expressing EGFP alone showed population responses and single-cell amperometric responses indistinguishable from those of control non-transfected cells. In contrast, co-expression of BoNT/C1 with EGFP resulted in an almost complete inhibition of current transients due to exocytosis evoked by ATP. These results establish and validate a single-cell assay of transfection-amperometry for analysing the effects of specific proteins on exocytosis.

Animals↗

PubMed1999

Protein markers in colorectal cancer: predictors of liver metastasis.

OBJECTIVE: To assess the significance of the expression of five protein markers (nm23, p53, c-erbB-2, u-PA, and VEGF) to the development of metastasis in colorectal cancer. SUMMARY BACKGROUND DATA: The metastatic cascade is a complex multistep process involving several genetic alterations, angiogenesis activation, and tissue proteolysis. Although the prognosis of colorectal cancer depends on the stage of the tumor, the development of metastasis is difficult to predict. METHODS: Paraffin-embedded specimens of 58 patients who underwent surgery for colorectal cancer were retrospectively analyzed by immunohistochemistry, and the coexpression of these protein markers was related to patient outcome. RESULTS: The risk of developing liver secondaries was correlated with the expression of nm23 protein (p < 0.0001); this was also the case in those patients with Dukes' stage B showing positive nm23 immunostaining (p = 0.006). The determination of the number of positive markers or the cumulative intensity score did not improve the predictive value over and above that of nm23 protein alone. CONCLUSION: Expression of nm23 protein is correlated with the risk of developing liver metastasis. Its evaluation alone may help to determine which patients who have undergone apparently curative resection of a colorectal cancer have an increased risk of liver recurrence, especially those with Dukes' stage B tumors who might be considered for adjuvant chemotherapy.

Adult↗

PubMed1998

Overexpression of nm23 protein assessed by color video image analysis in metastatic colorectal cancer: correlation with reduced patient survival.

The function and prognostic significance of the nm23 gene is controversial in colorectal cancer (CRC). The aim of this study was to determine if nm23 protein expression correlated with the subsequent development of liver metastasis. Paraffin-embedded sections of 30 metastasizing CRC primaries and their subsequently resected liver secondaries were compared with those of 28 nonmetastasizing CRCs, 20 adenomas, and 20 cases of normal colonic mucosa. Expression of nm23 protein, assayed by immunohistochemistry, was measured using a standard semiquantitative scaling system and compared with a microcomputerbased color video image analysis (VIA). There was good correlation between color VIA and semiquantitative evaluation of nm23 immunoreactivity, confirming the validity of quantitative analysis (Pearson's r = 0.88; p < 0.001). Metastasizing CRC primaries and secondaries overexpressed nm23 protein when compared with the other clinical groups, particularly nonmetastasizing CRC (Student's t-test, p < 0.001). Furthermore, more nm23 immunoreactivity was associated with a higher risk of death from CRC (log-rank test, p = 0.002). These results suggest that overexpression of nm23 is highly associated with liver metastases from CRC and reduced survival.

Antigens, Neoplasm↗

PubMed1998

BIAcore for macromolecular interaction.

Examination of the literature for the period of this review revealed nearly two hundred citations that employed surface plasmon resonance (SPR) spectroscopy using BIAcore technology to evaluate biospecific interactions, demonstrating the increasing popularity of this powerful technique. Among these we noted the development of several new applications/modifications of standard techniques. In general, we find the qualitative aspects of the reported experiments to be excellent but the quantitative descriptions (kT, kon, koff, and keq) as well as the binding models still lagging behind.

Biosensing Techniques↗

PubMed1998

Sequence-specific binding of human immunodeficiency virus type 1 nucleocapsid protein to short oligonucleotides.

We have analyzed the binding of recombinant human immunodeficiency virus type 1 nucleocapsid protein (NC) to very short oligonucleotides by using surface plasmon resonance (SPR) technology. Our experiments, which were conducted at a moderate salt concentration (0.15 M NaCl), showed that NC binds more stably to runs of d(G) than to other DNA homopolymers. However, it exhibits far more stable binding with the alternating base sequence d(TG)n than with any homopolymeric oligodeoxyribonucleotide; thus, it shows a strong sequence preference under our experimental conditions. We found that the minimum length of an alternating d(TG) sequence required for stable binding was five nucleotides. Stable binding to the tetranucleotide d(TG)2 was observed only under conditions where two tetranucleotide molecules were held in close spatial proximity. The stable, sequence-specific binding to d(TG)n required that both zinc fingers be present, each in its proper position in the NC protein, and was quite salt resistant, indicating a large hydrophobic contribution to the binding. Limited tests with RNA oligonucleotides indicated that the preferential sequence-specific binding observed with DNA also occurs with RNA. Evidence was also obtained that NC can bind to nucleic acid molecules in at least two distinct modes. The biological significance of the specific binding we have detected is not known; it may reflect the specificity with which the parent Gag polyprotein packages genomic RNA or may relate to the functions of NC after cleavage of the polyprotein, including its role as a nucleic acid chaperone.

Capsid↗

PubMed1998

Correlates of urokinase-type plasminogen activator in colorectal cancer: positive relationship with nm23 and c-erbB-2 protein expression.

We undertook a study to analyze the expression of urokinase-type plasminogen activator (u-PA) protein in colorectal cancer (CRC) and to compare it with c-erbB-2 (HER2/neu) and nm23 protein expression. Paraffin-embedded specimens from 58 patients with CRC were retrospectively collected. Immunohistochemical staining of u-PA, c-erbB-2, and nm23 was quantitatively evaluated using a color video image analysis (color VIA) technique. No correlation was found between u-PA expression and tumor stage, age, sex, or tumor site. Although there was no evidence from our data that the level of u-PA in the primary tumors could predict risk of liver metastasis or survival duration, CRC showing overexpression of u-PA (above 85 pixels) had a worse prognosis (P = 0.013). There were significant positive correlations among all three u-PA, c-erbB-2, and nm23 proteins (u-PA vs. c-erbB-2, P = 0.003; u-PA vs. nm23, P < 0.001; c-erbB-2 vs. nm23, P = 0.001), suggesting that, in vivo, all proteins interact or are similarly regulated.

Biomarkers, Tumor↗

PubMed1997

Inhibition of vascular endothelial growth factor-induced endothelial cell migration by ETS1 antisense oligonucleotides.

Vascular endothelial growth factor (VEGF) increased the level of ETS1 mRNA in human umbilical vein endothelial cells (HUVEC) and human lung microvascular endothelial cells (HMVEC-L) over 5-fold. Protein levels were shown to increase concordantly. VEGF was also found to stimulate the invasiveness of endothelial cells as measured by migration through Matrigel- or gelatin-coated membranes. The VEGF-induced invasiveness was inhibited by ETS1 antisense oligonucleotides but not by a sense control. In addition, the ETS1 antisense oligonucleotides reduced the levels of ETS1 and urokinase-type plasminogen activator mRNAs. The antisense oligonucleotides directed against the ETS1 gene thus altered a cellular property of endothelial cells that is correlated with the ability of the cells to migrate through basement membranes. Together, these observations demonstrate a direct role for the ETS1 gene in angiogenesis.

Cell Division↗

PubMed1997

Correction of the NMR structure of the ETS1/DNA complex.

The ETS family of transcription factors consists of a group of proteins that share a highly conserved 85 amino acid DNA-binding domain (DBD). This family recognizes a consensus sequence rich in purine bases with a central GGAA motif. A comparison of the published three-dimensional structures of the DBD/DNA complexes of ETS1 by NMR [Werner et al. (1995) Cell, 83, 761-771] and the related Pu.1 by X-ray crystallography [Kodandapani et al. (1996) Nature, 380, 456-460] reveals an apparent discrepancy in which the protein domains bind with opposite polarity to their target sequences. This surprising and highly unlikely result prompted us to reexamine our NMR structure. Additional NMR experiments now reveal an error in the original interpretation of the spectra defining the orientation of the ETS1-DBD on DNA. It was originally reported that the ETS1-DBD bound to DNA with a bipartite motif involving major groove recognition via a helix-turn-helix element and minor groove recognition via protein side-chain intercalation. The presence of intercalation was deduced on the basis of numerous NOEs between several amino acids in the protein and a resonance at 12.33 ppm originally assigned to a DNA imino proton. New NMR experiments now conclusively demonstrate that this resonance, which is located within the DNA imino proton region of the spectrum, arises from the hydroxyl proton of Tyr86. Realization of this error necessitated reanalysis of the intermolecular NOEs. This revealed that the orientation of the ETS1-DBD in the complex is opposite to that originally reported and that a tryptophan residue does not intercalate into the DNA. The calculation of a new ensemble of structures based on the corrected data indicates that the structure of the ETS1-DBD/DNA complex is indeed similar to the X-ray structure of the Pu.1-DBD/DNA complex.

Amino Acid Sequence↗

PubMed1997

Relationship between radiation response and p53 status in human bladder cancer cells.

Mutations in the p53 tumour suppressor gene are found at high frequency in bladder cancer. There is strong evidence that p53 plays an important role in controlling the cell cycle after DNA damage by ionizing radiation. However, the effect of loss of p53 function on radiosensitivity is not yet clear. Radiotherapy combined with chemotherapy is the most common treatment for patients with invasive bladder cancer. Recently three bladder cancer cell lines have been established and this paper investigates the p53 status and clonogenic survival of these cell lines following irradiation. It was found that one line expresses wt p53 (UCRU-BL-13) and two lines contain a codon 72 polymorphism (UCRU-BL-17 and UCRU-BL-28). UCRU-BL-17 cells also contain a point mutation affecting codon 280. The level of p53 expression in the cell lines is clearly different, with UCRU-BL-17 expressing a higher level of p53 compared with UCRU-BL-13; UCRU-BL-28 expressed intermediate levels. The clonogenic survival of these cell lines has been determined. It was found that the line expressing a p53 mutation was more sensitive than those with wild type p53, providing support for a model in which loss of p53 function is associated with increased radiosensitivity, possibly due to reduced p53-dependent DNA repair.

Cell Survival↗

PubMed1997

Lactational performance of cows fed low or high ruminally undegradable protein prepartum and supplemental methionine and lysine postpartum.

Multiparous Holstein cows (n = 24) were fed diets containing 34 or 41% ruminally undegradable protein (RUP) for 30 d before parturition; then each group was fed a basal diet supplemented with or without ruminally stable Met (10.6 g/d) and Lys (15.2 g/d) for 75 d in the subsequent lactation. Supplementation of Met and Lys increased the milk yield of cows previously fed the low RUP diet, but milk yields before and after amino acid (AA) supplementation were similar for cows previously fed the high RUP diet. Milk protein content (percentage) increased from 2.83 to 2.96 for cows previously fed the high RUP diet. Milk protein yield increased from 1.13 to 1.21 kg/d when Met and Lys were fed. Data on AA concentration in plasma and AA extraction by the mammary gland suggest that the supplementation of Met and Lys corrected a Met limitation. According to the Cornell Net Carbohydrate and Protein System, the lactation diet was limiting for Met for maximum milk yield and was corrected by AA supplementation. Based on limiting AA, allowable milk yield was 42.5 kg/d, and the observed yield was 40.9 kg/d averaged across treatments. The group with the greatest allowable milk yield (45.2 kg/d) had the greatest actual milk yield (43.0 kg/d). The regression equation of observed milk yield on allowable milk yield was Y = 3.4 + 0.8805X.

Animals↗

PubMed1997

Adequacy of amino acids in diets fed to lactating dairy cows.

The Cornell Net Carbohydrate and Protein System was used to evaluate absorbable limiting amino acids (AA) for milk yield. The system was utilized to characterize whether diets in five previous experiments met AA requirements for milk protein synthesis. Twenty-nine treatment means for milk yield from 367 cows constituted the database for the evaluation. Using the mechanistic relationships of nutrient metabolism described in the Cornell system, absorbed amounts were predicted of each essential AA from a diet and milk yields allowed by the most limiting AA. Regression of observed milk yield (Y) on predicted milk yield (X) using all treatment means (n = 29) was Y = 2.3 + 0.799X (r2 = 0.72). The linear relationship was stronger using 6 treatment means (n = 18) when protein supplements were fed rather than when ruminally protected AA were fed or when AA were postruminally infused (Y = -1.8 + 0.983X; r2 = 0.93). The Cornell system predicted that, for diets based on corn, Met or Lys was limiting when soybean meal was the protein source, but Lys was limiting when corn gluten meal or brewers grains were the source of protein. By AA limitation, the Cornell system explained differences in milk yield for diets that differed in supplemental protein sources in some of the experiments. As determined from milk protein yields in these studies, requirements for individual essential AA were expressed as a percentage of dietary dry matter or total essential AA, and values were relatively constant among dietary treatments and experiments.

Amino Acids↗

PubMed1996

The S29 ribosomal protein increases tumor suppressor activity of K rev-1 gene on v-K ras-transformed NIH3T3 cells.

The human S29 ribosomal protein (S29 rp) cDNA has been isolated from differential hybridization screening of a colon carcinoma cDNA library. Northern blot analysis showed that the level of S29 rp mRNA was higher in undifferentiated HT29 human colon carcinoma cells than in a morphologically differentiated subclone under the same growth condition. Furthermore, the level of S29 rp mRNA was downregulated in rapidly proliferating HT29 cells, as compared to the contact inhibited cells. Interestingly, the amount of Krev-1 mRNA was inversely correlated with respect to the amount of S29 rp mRNA in these cells. To examine a functional link between S29 rp and Krev-1 protein, we co-transfected the expression vectors containing wild-type or mutant S29 rp and mutationally activated Krev-1(63E) cDNAs into the v-Ki-ras-transformed NIH3T3 (DT) cells, and observed the induction of flat revertants. Krev-1(63E) induced a certain amount of flat colonies, while S29 rp alone also induced flat colonies at low frequencies. Interestingly, revertant-inducing activity of Krev-1(63E) was significantly enhanced by S29 rp. We have also demonstrated that a zinc finger-like domain of S29 rp indeed has a zinc binding activity and a derivative, S29 rp(ms), which was unable to bind zinc ion but still retained revertant inducing activity by itself, could not functionally interact with Krev-1(63E) protein.

3T3 Cells↗

PubMed1996

Radiotherapy for early infradiaphragmatic Hodgkin's disease: the Australasian experience.

PURPOSE: To review the Australasian results of Stage I and IIA Infradiaphragmatic Hodgkin's Disease (IHD) treated solely by irradiation. METHODS AND MATERIALS: Eligible patients had IHD only and were treated by irradiation with curative intent over the period of 1969 to 1988. Ten radiation oncology centres from within Australia and New Zealand were surveyed for patient, tumour and treatment variables. Disease free rates, survival and complications were analysed. RESULTS: 106 patients with IHD were studied. The average potential follow up was 9.4 years. The male to female ratio was 3.3:1. The median age was 37.5 years. Histological subgroups were as follows; lymphocyte predominant 43%, mixed cellularity 21%, lymphocyte depleted 5%, nodular sclerosing 27% and unclassifiable 4%. Fifty nine patients had laparotomy of which 22 (37%) were positive for tumour. Nine laparotomies were performed for diagnosis and the remainder for staging. One patient was up-staged by laparotomy and three were down-staged. Sixty-eight patients presented with inguinal disease alone, five with abdominal disease alone, 19 with two sites of involvement and 12 with inguinal, pelvic and abdominal disease. In two patients the site was unknown. There was no correlation between site of involvement, age, sex or histological subtype. Forty seven cases were clinically staged (CS) as follows: CS IA-23, CS IIA-24. The other 59 were pathologically staged (PS) as follows: PS IA-37, PS IB-1, PS IIA-21. Treatment consisted of involved field alone (16), inverted Y (68), inverted Y and spleen (13), para-aortic irradiation only (3), or total nodal irradiation (6). Mean dose was 37 Gy. There were 30 recurrences to give an acturial 10-year disease-free rate of 70%. In multivariate analysis lower number of tumour sites, lymphocyte predominant histology and higher dose were all significantly correlated with higher disease free rates. Eight patients died of Hodgkin's disease and 19 of other causes. The 10-year overall survival rate was 71%. Older age and higher number of disease sites were significantly correlated with shorter survival. Fourteen of 30 relapses may have been avoidable by the use of total nodal irradiation. In particular ten of 21 patients with abdominal disease relapsed in nodal sites which would have been covered by total nodal irradiation. CONCLUSIONS: The rate of control in IHD could perhaps be improved by avoiding involved field irradiation or by aggressive therapy with total nodal irradiation or combined modality chemo-irradiation in Stage II disease. Staging laparotomy does not appear to be indicated.

Abdominal Neoplasms↗

PubMed1995

The solution structure of the human ETS1-DNA complex reveals a novel mode of binding and true side chain intercalation.

The solution structure of a 24.4 kDa specific complex of the DNA-binding domain (DBD) of the human ETS1 (hETS1) oncoprotein with a 17-mer DNA has been solved by NMR. The interaction of the hETS1 DBD with DNA reveals a surprising twist on the general features of helix-turn-helix (HTH)-DNA interactions. Major groove recognition involves the C-terminal two thirds of the HTH recognition helix, while minor groove recognition occurs via true intercalation of the side chain of Trp-28, which extends from the minor to the major groove. This results in a sharp kink of approximately 60 degrees and a widening of the minor groove over one-half turn of the DNA. The orientation of the HTH element of the hETS1 DBD with respect to the major groove is significantly rotated relative to other HTH proteins. These observations establish the ETS family of DNA-binding proteins as a distinct family of HTH proteins.

Amino Acid Sequence↗

PubMed1995

ERF: an ETS domain protein with strong transcriptional repressor activity, can suppress ets-associated tumorigenesis and is regulated by phosphorylation during cell cycle and mitogenic stimulation.

ERF (ETS2 Repressor Factor) is a novel member of the ets family of genes, which was isolated by virtue of its interaction with the ets binding site (EBS) within the ETS2 promoter. The 2.7 kb ubiquitously expressed ERF mRNA encodes a 548 amino acid phosphoprotein that exhibits strong transcriptional repressor activity on promoters that contain an EBS. The localization of the DNA-binding domain of the protein at the N-terminus and th repression domain at the C-terminus is reminiscent of the organization of ELK1-like members of the ets family; however, there is no significant homology between ERF and ELK1 or any other ets member outside the DNA-binding domain. The repressor activity of ERF can antagonize the activity of other ets genes that are known transcriptional activators. Furthermore, ERF can suppress the ets-dependent transforming activity of the gag-myb-ets fusion oncogene of ME26 virus. Although ERF protein levels remain constant throughout the cell cycle, the phosphorylation level of the protein is altered as a function of the cell cycle and after mitogenic stimulation. The ERF protein is also hyperphosphorylated in cells transformed by the activated Ha-ras and v-src genes and the transcription repressor activity of ERF is decreased after co-transfection with activated Ha-ras or the kinase domain of the c-Raf-1 gene, indicating that ERF activity is probably regulated by the ras/MAPK pathway. Consistent with the in vivo phosphorylation and inactivation by ras, ERF is efficiently phosphorylated in vitro by Erk2 and cdc2/cyclin B kinases, at sites similar to those detected in vivo. Furthermore, a single mutation at position 526 results in the loss of a specific phosphopeptide both in in vivo and in vitro (by Erk2) labeling. Substitution of Thr526 for glutamic acid also decreases the repression ability of ERF. Our data suggest a model in which modulation of ERF activity is involved in the transcriptional regulation of genes activated during entry into G1 phase. Obstruction of the ERF repressor function by the transactivating members of the ets family of genes (i.e.gag-myb-ets) may be essential for the control of genes involved in cell proliferation and may also underlie their tumorigenic effects.

3T3 Cells↗

PubMed1995

Oropharyngeal cancer in the elderly.

PURPOSE: The poor prognosis of elderly patients in many cancers may be due to less thorough investigation and less aggressive treatment because of the perception that radical treatment will be poorly tolerated and that elderly patients have a limited life expectancy. We wished to assess whether older age is associated with (a) less radical treatment, (b) poorer outcome, or (c) greater toxicity, after adjusting for other possible contributing factors. METHODS AND MATERIALS: A retrospective study of patients with loco-regional oropharyngeal cancer treated between January 1980 and December 1985 was conducted. Patients were treated with radiotherapy, surgery, chemotherapy, or combinations. Cox regression was used to assess age effects while allowing for the influence of other factors. RESULTS: Eighty-eight patients were treated radically and 16 palliatively. Treatment intent (radical or palliative) did not appear to be related to age, before (p = 0.42) or after adjusting for other factors (p = 0.34). In a selected group of 86 radically treated patients ages ranged from 33 to 85 (median 60). There were 35 loco-regional failures and 58 deaths (38 related to oropharyngeal cancer). Older patients were prescribed and received lower doses of radiation. However, older age was not related to the risk of loco-regional recurrence (p = 0.96) or shorter survival (p = 0.67), and was not associated with duration of treatment interruption or severity of toxicity after adjustment for prognostic factors. There was some suggestion of a higher risk of recurrence with increasing age for patients under 70 years but with a risk for patients over 70 at least equal to that of the youngest group. Elderly patients in our study may have been a selected group. CONCLUSION: Older patients with loco-regional oropharyngeal cancer, or at least a subset of them, appear to be able to tolerate radical courses of radiotherapy, and to have similar outcomes as do younger patients.

Adult↗