Comparative study on transduction and toxicity of protein transduction domains

BACKGROUND AND PURPOSE

Protein transduction domains (PTDs), such as Tat, antennapedia homeoprotein (Antp), Rev and VP22, have been extensively utilized for intracellular delivery of biologically active macromolecules in vitro and in vivo. There is little known, however, about the relative transduction efficacy, cytotoxicity and internalization mechanism of individual PTDs.

EXPERIMENTAL APPROACH

We examined the cargo delivery efficacies of four major PTDs (Tat, Antp, Rev and VP22) and evaluated their toxicities and cell internalizing pathways in various cell lines.

KEY RESULTS

The relative order of the transduction efficacy of these PTDs conjugated to fluorescein was Rev>Antp>Tat>VP22, independent of cell type (HeLa, HaCaT, A431, Jurkat, MOLT-4 and HL60 cells). Antp produced significant toxicity in HeLa and Jurkat cells, and Rev produced significant toxicity in Jurkat cells. Flow cytometric analysis demonstrated that the uptake of PTD-fluorescein conjugate was dose-dependently inhibited by methyl-beta-cyclodextrin, cytochalasin D and amiloride, indicating that all four PTDs were internalized by the macropinocytotic pathway. Accordingly, in cells co-treated with 'Tat-fused' endosome-disruptive HA2 peptides (HA2-Tat) and independent PTD-fluorescent protein conjugates, fluorescence spread throughout the cytosol, indicating that all four PTDs were internalized into the same vesicles as Tat.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that macropinocytosis-dependent internalization is a crucial step in PTD-mediated molecular transduction. From the viewpoint of developing effective and safe protein transduction technology, although Tat was the most versatile carrier among the peptides studied, PTDs should be selected based on their individual characteristics.

Quantitative evaluation of the petal shape variation in Primula sieboldii caused by breeding process in the last 300 years

Primula sieboldii: (E. Morren) has been a popular garden plant at least since the Edo period, about 300 years ago. We compared petal form between cultivars and wild populations in order to characterise the changes that have occurred during domestication. The comparison was made using EF-PCA analysis, which describes overall petal shape mathematically by transforming petal contour coordinates into elliptic Fourier descriptors; it subsequently summarises these descriptors by principal component analysis (PCA). Rearing cultivars in a common-garden experiment identified the PCs with a substantial genetic element. A clear heritable component was detected for the PCs characterising symmetrical variation in flower shape, but not the asymmetrical variation. Wild populations of this species have become endangered owing to habitat destruction by human activity, and many lowland floodplain habitats have been lost. Variation within the remaining wild populations was significantly lower than in the cultivars for PC1 (aspect ratio), PC3 (curvature of proximal and distal parts) and petal area; but not for PC2 (depth of head notch) and PC4 (position of the centre of gravity). The shifts in petal form from the wild populations to the cultivars parallel those seen in other crop-types following domestication, including an increase in size and diversity of forms: cultivars have shallower head notches, more fan-shaped petals and larger petals than do wild P. sieboldii.

[Aortic valve replacement presence of anti-Jr(a) antibody]

A 65-year-old female with a heart murmur developed progressive symptom of chest oppression. She was diagnosed severe aortic valve stenosis with echocardiogram. Antibody screening revealed anti-Jr(a) antibody. Preoperatively, erythropoietin was administered. Over 14 days, a total 1,000 ml of her blood was drawn and stored for autologous transfusion. The aortic valve was replaced with ATS mechanical valve [18 mm advanced performance (AP)]. Following surgery, her stored blood was administered to him. But her HCT was 17% on the 1st postoperative day. Frozen thawed red cells were transferred 7th postoperative day.

Explanations for the smoking paradox in Japan

The prevalence of cigarette smoking among Japanese men has been consistently high compared with Western males over the past 30 years. However, during the same period, the incidence of and mortality rates for lung cancer have consistently been lower in Japan than in Western countries ('Japanese smoking paradox'). The odds ratio/relative risk of cigarette smoking for lung cancer mortality/incidence relative to the same number of cigarettes smoked per capita in Japan, were apparently lower than those in Western countries. This must be the cause driving the 'Japanese smoking paradox'. Furthermore, low carcinogenic ingredients in Japanese cigarettes and a congenitally-related resistance to smoking-related lung carcinogenesis emerged as the main factors which have brought the 'Japanese smoking paradox'.

[Surgical treatment for left ventricular false aneurysm caused by infective endocarditis; report of a case]

A 24-year-old man who had left ventricular (LV) false aneurysm, which is caused by mitral valve infective endocarditis, underwent aneurysmectomy, direct closure of aneurysmal mouth and concomitant mitral valve replacement. Post-operative course was uneventful. It has been reported that the etiology of this false aneurysm was due to the vegetations' friction, which could have caused an initial endocardial ulceration that progressively expanded into the myocardium. The false aneurysmal wall should be completely removed in order to eliminate the possibility of recurrence of the infective endocarditis. We believe that the surgical treatment should be carried out as soon as possible after completion of diagnosis because the aneurysmal wall is usually quite thin and could rupture easily.

[Prosthetic valve endocarditis after aortic valve replacement with freestyle stentless xenograft]

A 52-year-old man underwent aortic valve replacement with freestyle stentless xenograft, using subcoronary technique for active infective endocarditis in June, 2001. Eighteen month later he had late prosthetic valve endocarditis associated with aortic annular abscess due to Staphylococcus epidermidis infection. The abscess was debrided and gelatin-resorcin-formalin glue (GRF glue) was injected into the abscess cavity. Abscess cavity was closed with continuous running suture of 3-0 polypropylene stitches. Finally the aortic valve was replaced with ATS mechanical valve (20 mmAP). After administration of vancomycin and gentamicin for 4 weeks, he discharged on 57th postoperative day in good condition. We strongly suggest that GRF glue is essential to close the aortic annular abscess of combined with aortic regurgitation due to active infective endocarditis.

[Thymic carcinoma (mixed small cell undifferentiated squamous cell carcinoma); report of a case]

A 52-year-old man was admitted to our hospital on October, 1997 with complains of left anterior chest pain. A chest X-ray and computed tomography on admission showed evidence of a mass in the left anterior mediastinum. The patient was treated with combination chemotherapy [cisplatin (CDDP), etoposide (VP-16)] and radiation therapy (2 gray x 25 days), preoperatively. Median sternotomy revealed a tumor invading into the left anterior chest wall, the pericardium, and partial pleura. The tumor was extirpated with combined resection of invaded organs. Microscopically and immunohistochemically, the tumor was diagnosed mixed small cell and undifferentiated squamous cell carcinoma documented by Snover et al. The patient was discharge on March 1998, but 2 years later after operation, he was dead by recurrent. We reported a rare case of thymic carcinoma.

Nitric oxide at a low concentration protects murine macrophage RAW264 cells against nitric oxide-induced death via cGMP signaling pathway

1. We investigated the cytoprotective effect of low-dose nitric oxide (NO) on NO-induced cell death in mouse macrophage-like cell line RAW264. 2. Sodium nitroprusside (SNP), an NO donor, at a high concentration (4 mM) released cytochrome c from mitochondria and induced death in RAW264 cells. Acetyl-L-aspartyl-L-glutamyl-L-valyl-L-aspart-1-al (Ac-DEVD-CHO, 100-200 microM), a caspase-3 inhibitor, attenuated the SNP-induced cell death in a concentration-dependent manner. 3. Pretreatment with 100 microM SNP for 24 h, which had no effect on cell viability, attenuated the cell death and reduced cytochrome c release from mitochondria to the cytosol induced by 4 mM SNP. 4. LY83583 (1-3 microM) and 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, 30-100 microM), soluble guanylate cyclase inhibitors, negated the protective effect of the 100 microM SNP pretreatment. 5. Pretreatment with 1 mM dibutylyl guanosine-3',5'-cyclic monophosphate (DBcGMP), a cell-permeable guanosine-3',5'-cyclic monophosphate (cGMP) analogue, for 24 h inhibited both cytochrome c release and cell death induced by SNP. 6. Protein kinase G inhibitor KT5823 (10 microM) significantly reduced the cytoprotective effects of low-dose SNP and DBcGMP. 7. These results indicate that low-dose NO protects RAW264 cells from NO-induced apoptosis through cGMP production and activation of protein kinase G.

VEGF regulates the proliferation of acid-exposed alveolar lining epithelial cells

BACKGROUND

Acid induced pneumonitis resulting in acute respiratory distress syndrome (ARDS) is characterised by increased alveolar permeability and accumulation of neutrophils. It is hypothesised that vascular endothelial growth factor (VEGF) is involved in the development of lung oedema. Furthermore, lower levels of VEGF are detected in bronchoalveolar lavage fluid from patients with ARDS than from non-ARDS patients. We hypothesised that VEGF acts cytoprotectively and have investigated this possibility in vitro with A549 cells.

METHODS

A549 cells were incubated in 24 well culture dishes 24 hours before exposure to acid, then incubated with serum free medium containing various concentrations of HCl for 30 minutes at 37 degrees C in 5% CO(2). The acidified medium was changed to normal complete medium; at specified incubation periods the supernatants were collected and the VEGF concentration measured and the number of adherent cells counted.

RESULTS

Proliferation of A549 cells and VEGF production were suppressed for at least 48 hours in HCl at a concentration of 50 mM. Restoration of cellular proliferation occurred following exogenous administration of VEGF (concentration of 1-250 ng/ml) and was inhibited by co-incubation with neutralising anti-VEGF antibody, indicating an interaction between VEGF molecules and A549 cells. Control cells were not influenced by administration of exogenous VEGF or anti-VEGF antibody. Treatment with neutralising anti-VEGF receptor (VEGFR) antibodies against VEGFR-1 and VEGFR-2 suppressed proliferation of acid exposed A549 cells but had no effect on control cells.

CONCLUSIONS

Exogenous VEGF interacts with VEGFR-1 and VEGFR-2 on the surface and regulates the proliferation of injured alveolar lining epithelial cells in an autocrine or paracrine fashion.

Proposal of a new grading system for evaluation of tongue hemiatrophy as a late effect of brachytherapy for oral tongue cancer

PURPOSE

To evaluate tongue hemiatrophy as a late effect of brachytherapy, a new grading system was designed and applied to patients who had received low dose rate (LDR) or high dose rate (HDR) brachytherapy for early tongue cancer.

METHODS AND MATERIALS

Between December 1998 and April 1999, 49 patients who had received brachytherapy for early tongue cancer (T1/T2=22:27) at Osaka University Hospital were investigated. All patients had undergone either LDR or HDR brachytherapy with Ir-192 (LDR/HDR=30:19) between 1980 and 1998. Atrophic changes in their tongue were classified into four categories (G0-G3): G3, not able to protrude the tongue beyond incisors; G2, hemiatrophy is seen on the irradiated side in the resting position of the tongue; G1, deviation of the tip of the tongue to the irradiated side is seen when protruded; and G0, none of these signs. The relationship between tongue hemiatrophy and tumor factors, treatment factors, and patients' functional impairment was then investigated. The median time from treatment to assessment was 75 months (range 8-219 months). Volume index was defined as the number of needles that were implanted vertically into the tongue.

RESULTS

Fourteen patients were classified as G0, 29 as G1, five as G2, and one as G3. None of the G0 patients showed any speech or swallowing dysfunction, pain or contracted feeling, or general dissatisfaction with post-treatment tongue status. There was a tendency for such problems to increase with the tongue hemiatrophy grade. The frequency of T2 and non-superficial type tumors also tended to increase with the tongue hemiatrophy grade. The volume index of the G2-3 hemiatrophy group was significantly larger than that of the G0-1 group (P=0.041).

CONCLUSION

This new grading system makes evaluation of atrophic changes in the tongue after brachytherapy easy and effective.

Adult-onset foveomacular vitelliform dystrophy with retinal folds

BACKGROUND

Adult-onset foveomacular vitelliform dystrophy is characterized by a solitary, oval, slightly elevated, yellowish subretinal lesion of the fovea. We examined a patient with adult-onset foveomacular vitelliform dystrophy with stellate retinal folds by optical coherence tomography and scanning laser ophthalomoscopy.

CASE

A 58-year-old Japanese woman with a complaint of decreased vision in her right eye was diagnosed as having adult-onset foveomacular vitelliform dystrophy.

OBSERVATIONS

Ophthalmoscopic examination revealed a yellowish lesion of one-third disc diameter in size at the fovea in the right eye. Fluorescein angiography demonstrated an irregular block of choroidal fluorescence corresponding to the yellowish lesion, which was surrounded by stellate retinal folds. Optical coherence tomography images showed a steep elevation of the retinal pigment epithelium (RPE) as a focally protruded reflective band over an optically clear space. Scanning laser ophthalmoscopy provided morphologic enhancement in the specifically affected layers of the macula. Using an argon green laser, band-shaped bright reflexes were seen in the right fovea. The helium-neon laser revealed a bright patch corresponding to the yellowish lesion over the fovea, which was surrounded by stellate retinal folds. The diode laser revealed a bright patch corresponding to the yellowish lesion.

CONCLUSION

The stellate retinal folds of this patient were considered to be caused by the steep elevation of the RPE with an extracellular accumulation of the vitelliform deposits.

Phase III trial of high- vs. low-dose-rate interstitial radiotherapy for early mobile tongue cancer

PURPOSE

Early mobile tongue cancer can be controlled with interstitial radiotherapy (ISRT). We carried out a Phase III trial to compare the treatment results of low-dose-rate (LDR) ISRT and high-dose-rate (HDR) ISRT for early mobile tongue cancer.

METHODS AND MATERIALS

From April 1992 through October 1996, 59 patients with cancer of the early mobile tongue were registered in this Phase III study. Eight patients were excluded from the evaluation because of violations of the requirements for this study. Of 51 eligible patients, 26 patients were treated with LDR-ISRT (70 Gy/4-9 days) and 25 patients with HDR-ISRT (60 Gy/10 fractions/1 week). For the hyperfractionated HDR-ISRT, the time interval between 2 fractions was more than 6 h.

RESULTS

Five-year local control rates of the LDR and HDR groups were 84% and 87% respectively. Nodal metastasis occurred in 6 patients in each group. Five-year nodal control rates of the LDR and HDR groups were 77% and 76%, respectively.

CONCLUSION

Hyperfractionated HDR-ISRT for early mobile tongue cancer has the same local control compared with continuous LDR-ISRT. Hyperfractionated HDR-ISRT is an alternative treatment for continuous LDR-ISRT.

Identification of a monofunctional aspartate kinase gene of Arabidopsis thaliana with spatially and temporally regulated expression

We screened a gene trap library of Arabidopsis thaliana and isolated a line in which a gene encoding a homologue of monofunctional aspartate kinase was trapped by the reporter gene. Aspartate kinase (AK) is a key enzyme in the biosynthsis of aspartate family amino acids such as lysine, threonine, isoleucine, and methionine. In plants, two types of AK are known: one is AK which is sensitive to feedback inhibition by threonine and carries both AK and homoserine dehydrogenase (HSD) activities. The other one is monofunctional, sensitive to lysine and synergistically S-adenosylmethionine, and has only AK activity. We concluded that the trapped gene encoded a monofunctional aspartate kinase and designated as AK-lys3, because it lacked the HSD domain and had an amino acid sequence highly similar to those of the monofunctional aspartate kinases ofA. thaliana. AK-lys3 was highly expressed in xylem of leaves and hypocotyls and stele of roots. Significant expression of this gene was also observed in trichomes after bolting. Slight expression of AK-lys3 was detected in vascular bundles and mesophyll cells of cauline leaves, inflorescence stems, sepals, petals, and stigmas. These results indicated that this aspartate kinase gene was not expressed uniformly but in a spatially specific manner.

Mitochondrial genotypes and radiation-induced micronucleus formation in human osteosarcoma cells in vitro

We investigated whether or not the mitochondrial genotypes affect radiation-induced micronucleus (MN) formation. For that purpose, the rho+, KT1 and rho0 human osteosarcoma cell lines were used, which carry the wild-type mitochondrial DNA (mtDNA), the tRNALys mutant mtDNA and no mtDNA, respectively. Despite no significant difference in the clonogenic radiosensitivity, the rho+, KT1 and rho0 cells exhibited high, intermediate and low radiosensitivities, respectively, to the MN induction in cytokinesis-blocked binucleated cells. Such differential MN inductions were correlated with high, intermediate and low levels of cellular ATP in the rho+, KT1 and rho0 cells, respectively, but not exactly with ROS production. Antimycin A that inhibits the respiratory complex III reduced the rate of radiation-induced MN induction in the rho+ and KT1, but not rho0 cells. Thus, the functional status of the mtDNA to produce ATP appears to play a significant role for radiation-induced MN.

[Suppression of stress proteins, GRP78, GRP94, calreticulin and calnexin in liver endoplasmic reticulum of rat treated with a highly toxic coplanar PCB]

The present study was addressed on the effect of 3,3',4,4',5-pentachlorobiphenyl (PenCB) to the expression of molecular chaperon proteins, glucose regulated protein (GRP) 78, GRP94, calreticulin and calnexin in liver endoplasmic reticulum of rat by treatment with acute exposure. Male Wistar rats received PenCB in corn oil at once a dose of 10 mg/kg i.p., then at 5 days after treatment the microsomes were prepared. Free-fed and pair-fed control groups were given the vehicle. The microsomal proteins were separated on SDS-PAGE, transferred to membrane and blotted using antibody towards respective chaperone proteins. The protein levels of GRP78, GRP94, calreticulin and calnexin were significantly decreased with the acute exposure. In addition, albumin level in the microsomes was also significantly reduced by the PenCB treatment. The transferrin level was significantly higher than pair-fed but not from free-fed group. These chaperone proteins have important physiological functions against synthesized and/or denatured proteins, which include assembling, folding of proteins. PenCB-treatment may alter the extent of biosynthesis of secretory protein such as albumin through the decreasing levels of chaperone proteins in endoplasmic reticulum. Interestingly, reduced GRP78 protein level by PenCB was not due to decreased mRNA level. Our results suggested that a part of the toxicity of PenCB is associated to significant decrease of the chaperone proteins in the endoplasmic reticulum.

Influence of thoracic radiotherapy on exhaled nitric oxide levels in patients with lung cancer

BACKGROUND

To determine the physiological role of exhaled nitric oxide (NO) in patients with lung cancer.

METHODS

We investigated changes in exhaled NO levels in 29 patients undergoing thoracic radiation therapy with or without chemotherapy. The exhaled NO level was assessed using a chemiluminescence analyzer.

RESULTS

The level of exhaled NO was higher in patients with lung cancer before treatment than in controls. With radiotherapy, the exhaled NO level decreased for patients undergoing 40 Gy irradiation and post-radiotherapy. However, five patients showed elevated levels of exhaled NO three times or more than that before radiotherapy. Three of these patients showed signs of radiation pneumonitis. However, none of the other patients showed signs of radiation pneumonitis (p = 0.002).

CONCLUSION

Radiation therapy can lower exhaled levels of NO and the levels of exhaled NO may be a useful index for the early prediction of radiation pneumonitis.

Influence of age on the results of brachytherapy for early tongue cancer

PURPOSE

To determine the influence of elder age on the results of brachytherapy for early (T1-2 N0 M0) oral tongue cancer and examine the compatibility of low-dose rate (LDR) with high-dose rate (HDR) brachytherapy.

METHODS AND MATERIALS

We analyzed 591 patients treated at Osaka University Hospital between 1967 and 1999. We compared the results of radiotherapy for 156 elderly patients (137 LDR and 19 HDR) 65 years of age or older and 435 patients (383 LDR and 52 HDR) less than 65 years of age.

RESULTS

HDR brachytherapy showed the same local control rate as LDR brachytherapy (81% at 3 years). Elderly patients showed a poorer local control rate (75% at 3 years) than the younger group (83% at 3 years)(p = 0.002). Multivariate analysis identified age as the only prognostic factor for local control (p = 0.002).

CONCLUSIONS

HDR brachytherapy achieved the same result as LDR brachytherapy. However, the elderly patient showed a higher rate of local recurrence after brachytherapy.

Endothelins increase tyrosine phosphorylation of astrocytic focal adhesion kinase and paxillin accompanied by their association with cytoskeletal components

Astrocytic endothelin receptors are involved in the appearance of activated astrocytes upon injury of the brain [Ishikawa N. et al. (1997) Eur. J. Neurosci. 9, 895-901; Koyama Y. et al. (1999) Glia 26, 268-271]. To clarify signal transduction triggered by endothelin receptors, we examined the effects of endothelins on protein tyrosine phosphorylation in cultured rat astrocytes. Endothelin-1 (1 nM) increased tyrosine phosphorylation of focal adhesion kinase and paxillin. The tyrosine phosphorylation was also induced by endothelin-1 (1 nM) and Ala(1,3,11,15)-endothelin-1 (10nM), an endothelin-B receptor agonist. BQ788 (100 nM), an endothelin-B receptor antagonist, inhibited the effects of endothelin-3. Orthovanadate (VO(4)(3-)), a tyrosine phosphatase inhibitor, but not bradykinin (1 microM), angiotensin II (100 nM), A23187 (5 microM) and phorbol 12-myristate 13-acetate (100 nM), increased tyrosine phosphorylation of focal adhesion kinase and paxillin. The tyrosine phosphorylation by endothelin-3 was not prevented by pertussis toxin, Ca(2+) chelation, protein kinase C inhibitors (calphostin C and staurosporine) or wortmannin. Immunocytochemical staining showed that endothelin-3 and VO(4)(3-) induced redistribution of focal adhesion kinase and paxillin to focal adhesions concomitant with stress fiber formation in dibutyryl cyclic-AMP-treated astrocytes. Treatment with endothelin-3 and VO(4)(3-) increased focal adhesion kinase and paxillin associated with astrocytic cytoskeletal fraction. In the presence of cytochalasin B, an actin disrupting agent, endothelin-3 and VO(4)(3-) did not phosphorylate focal adhesion kinase and paxillin. Application of cytochalasin B after treatment with endothelin-3 and VO(4)(3-) stimulated dephosphorylation of focal adhesion kinase and paxillin. These results suggest that the associations of focal adhesion kinase and paxillin with cytoskeletal components are required in the endothelin-induced tyrosine phosphorylation of the astrocytic proteins.

Enhancing effects of fibroblast growth factor on the proliferation of salivary gland carcinoma cells and salivary gland carcinogenesis

The proliferation of mouse submandibular gland carcinoma YT-12 cells was stimulated by endothelial cell growth factor (ECGF)/bovine brain-derived acidic fibroblast growth factor (aFGF) and recombinant human aFGF. To determine whether aFGF was capable of modifying salivary gland carcinogenesis, the effect of brain-derived aFGF was examined in vivo. Mice in Groups 1 and 2 were injected with 9,10-dimethyl-1,2-benzanthracene (DMBA) into the left submandibular gland, and then Group 1 mice received bovine brain-derived aFGF and Group 2 mice received vehicle subcutaneously for 10 weeks. Group 3 and 4 mice received either bovine brain-derived aFGF or vehicle only. Sixteen weeks after the start of the experiment, the incidence of submandibular gland carcinomas in Group 1 was significantly greater than that in Group 2. Immunohistochemical study indicated that ducts in the normal submandibular glands and carcinomas showed positive staining with anti-aFGF antibody. Immunoblot and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed the expression of aFGF in these tissues. FGF receptor (FGFR)-1 and FGFR-4 were detectable in the mouse submandibular glands and carcinomas. These findings suggest that bovine brain-derived aFGF stimulates the proliferation of submandibular gland carcinoma cells and promotes mouse submandibular gland carcinogenesis.

Changes in performance status of elderly patients after radiotherapy

BACKGROUND

To examine the feasibility of external radiation therapy for patients 80 years old and older.

METHODS

We analyzed changes in the performance status (PS) of 1353 patients by external radiotherapy at Osaka Teishin Hospital. In addition, factors influencing PS change and interruption of treatment were assessed in patients undergoing radical and palliative radiotherapy.

RESULTS

Among elderly patients aged 80 years or more (n=67), two patients showed deterioration in PS (3%), whereas 128 (10%) did so among those 79 years old or younger. The rate of treatment completion was 90% (60/67) for patients aged 80 years and over compared with 89% (1146/1286) for younger patients. Changes in PS were more frequent for palliative treatment (improvement 83/683, 12%; deterioration 77/683, 11%) than for radical treatment (improvement 12/305, 4%; deterioration 21/305, 7%) because patients with better performance status and early disease stages underwent radical treatment. For radical radiotherapy, patients with advanced disease (stages III and IV) showed more changes (improvement 4/108, 4%; deterioration 17/108, 16%) than those with early ones (stages I and II)(improvement 7/132, 5%; deterioration 3/132, 2%) (p<0.01). Better treatment results showed a higher treatment completion rate (CR 99%, PR 86%) than poor treatment results (NC 75%, PD 50%)(p<0.01). For palliative therapy, better performance status (PS 0-2) showed a better correlation with completion of treatment (403/451 or 89%) than did poor performance status (PS 3-4)(174/ 232, 75%)(p<0.01).

CONCLUSIONS

Age is not a limiting factor for external radiation therapy. Poor performance status is a significant predisposing factor for interruption of palliative radiotherapy.