273 research outputs found
Experimental two dimensional cellular flames
International audienceThe propagation of very unstable cellular flames (also called self-turbulent flames) is studied experimentally in a Hele-Shaw cell. This quasi-two dimensional configuration allows for quantitative image analysis. The dynamics of the premixed flame is controlled in these conditions by the creation or merging of the cusps that appear on the front
Long-term spatiotemporal stability and dynamic changes in helminth infracommunities of bank voles (Myodes glareolus) in NE Poland
Parasites are considered to be an important selective force in host evolution but ecological studies of host-parasite systems are usually short-term providing only snap-shots of what may be dynamic systems. We have conducted four surveys of helminths of bank voles at three ecologically similar woodland sites in NE Poland, spaced over a period of 11 years, to assess the relative importance of temporal and spatial effects on helminth infracommunities. Some measures of infracom- munity structure maintained relative stability: the rank order of prevalence and abundance of Heligmosomum mixtum, Heligmosomoides glareoli and Mastophorus muris changed little between the four surveys. Other measures changed markedly: dynamic changes were evident in Syphacia petrusewiczi which declined to local extinction, while the capillariid Aonchotheca annulosa first appeared in 2002 and then increased in prevalence and abundance over the remaining three surveys. Some species are therefore dynamic and both introductions and extinctions can be expected in ecological time. At higher taxonomic levels and for derived measures, year and host-age effects and their interactions with site are import- ant. Our surveys emphasize that the site of capture is the major determinant of the species contributing to helminth community structure, providing some predictability in these systems
Metastatic squamous cell carcinoma of an unknown primary localized to the neck. Advantages of an aggressive treatment.
Treatment of patients with squamous cell carcinoma (SCC) of an unknown primary localized to the neck is still controversial, particularly regarding advanced disease. We reviewed 41 such patients treated with surgery and/or radiotherapy (RT) (n = 25) or with combined modality treatment including chemotherapy (CH) (n = 16). The male to female ratio was 28 to 13, and the median age was 58 years (range, 32 to 94 years). There were 27 (66%) patients with poorly differentiated SCC and 8 with moderately differentiated or well-differentiated cancer. Twenty-three (56%) patients had N3 disease, 16 (39%) had N2, and 2 had N1. The majority of N3 patients have been treated with CH and RT (n = 12) or with RT alone (n = 9). The combined CH-RT was well tolerated, with no life-threatening toxicity. The complete response (CR) to CH-RT was 81% (11 patients have no evidence of disease [NED] currently). The median survival time of this group was 37+ months. Of the 25 patients who had surgery and/or RT as their first planned treatment, 7 (28%) have NED currently. The median survival time of this group was 24 months. Patients with N3 disease who received CH had a higher CR rate and a longer survival time as compared with those treated with surgery and/or RT, despite a higher (N3) stage of disease. These findings warrant further investigation in randomized cooperative studies
Sensorineural hearing loss after concurrent chemoradiotherapy in nasopharyngeal cancer patients
<p>Abstract</p> <p>Background</p> <p>Sensorineural hearing loss (SNHL) is one of the major long term side effects from radiation therapy (RT) in nasopharyngeal cancer (NPC) patients. This study aims to review the incidences of SNHL when treating with different radiation techniques. The additional objective is to determine the relationship of the SNHL with the radiation doses delivered to the inner ear.</p> <p>Methods</p> <p>A retrospective cohort study of 134 individual ears from 68 NPC patients, treated with conventional RT and IMRT in combination with chemotherapy from 2004-2008 was performed. Dosimetric data of the cochlea were analyzed. Significant SNHL was defined as > 15 dB increase in bone conduction threshold at 4 kHz and PTA (pure tone average of 0.5, 1, 2 kHz). Relative risk (RR) was used to determine the associated factors with the hearing threshold changes at 4 kHz and PTA.</p> <p>Results</p> <p>Median audiological follow up time was 14 months. The incidence of high frequency (4 kHz) SNHL was 44% for the whole group (48.75% in the conventional RT, 37% with IMRT). Internal auditory canal mean dose of > 50 Gy had shown a trend to increase the risk of high frequency SNHL (RR 2.02 with 95% CI 1.01-4.03, p = 0.047).</p> <p>Conclusion</p> <p>IMRT and radiation dose limitation to the inner ear appeared to decrease SNHL.</p
Phase II randomised trial of chemoradiotherapy with FOLFOX4 or cisplatin plus fluorouracil in oesophageal cancer
International audienceBackground: Concurrent chemoradiotherapy is a valuable treatment option for localised oesophageal cancer (EC), but improvement is still needed. A randomised phase II trial was initiated to assess the feasibility and efficacy in terms of the endoscopic complete response rate (ECRR) of radiotherapy with oxaliplatin, leucovorin and fluorouracil (FOLFOX4) or cisplatin/fluorouracil. Methods: Patients with unresectable EC (any T, any N, M0 or M1a), or medically unfit for surgery, were randomly assigned to receive either six cycles (three concomitant and three post-radiotherapy) of FOLFOX4 (arm A) or four cycles (two concomitant and two post-radiotherapy) of cisplatin/fluorouracil (arm B) along with radiotherapy 50 Gy in both arms. Responses were reviewed by independent experts. Results: A total of 97 patients were randomised (arm A/B, 53/44) and 95 were assessable. The majority had squamous cell carcinoma (82%; arm A/B, 42/38). Chemoradiotherapy was completed in 74 and 66%. The ECRR was 45 and 29% in arms A and B, respectively. Median times to progression were 15.2 and 9.2 months and the median overall survival was 22.7 and 15.1 months in arms A and B, respectively. Conclusion: Chemoradiotherapy with FOLFOX4, a well-tolerated and convenient combination with promising efficacy, is now being tested in a phase III trial
Riboflavin Ameliorates Cisplatin Induced Toxicities under Photoillumination
BACKGROUND: Cisplatin is an effective anticancer drug that elicits many side effects mainly due to induction of oxidative and nitrosative stresses during prolonged chemotherapy. The severity of these side effects consequently restricts its clinical use under long term treatment. Riboflavin is an essential vitamin used in various metabolic redox reactions in the form of flavin adenine dinucleotide and flavin mononucleotide. Besides, it has excellent photosensitizing property that can be used to ameliorate these toxicities in mice under photodynamic therapy. METHODS AND FINDINGS: Riboflavin, cisplatin and their combinations were given to the separate groups of mice under photoilluminated condition under specific treatment regime. Their kidney and liver were excised for comet assay and histopathological studies. Furthermore, Fourier Transform Infrared Spectroscopy of riboflavin-cisplatin combination in vitro was also conducted to investigate any possible interaction between the two compounds. Their comet assay and histopathological examination revealed that riboflavin in combination with cisplatin was able to protect the tissues from cisplatin induced toxicities and damages. Moreover, Fourier Transform Infrared Spectroscopy analysis of the combination indicated a strong molecular interaction among their constituent groups that may be assigned for the protective effect of the combination in the treated animals. CONCLUSION: Inclusion of riboflavin diminishes cisplatin induced toxicities which may possibly make the cisplatin-riboflavin combination, an effective treatment strategy under chemoradiotherapy in pronouncing its antineoplastic activity and sensitivity towards the cancer cells as compared to cisplatin alone
Feasibility of intensity-modulated and image-guided radiotherapy for locally advanced esophageal cancer
BACKGROUND:In this study the feasibility of intensity-modulated radiotherapy (IMRT) and tomotherapy-based image-guided radiotherapy (IGRT) for locally advanced esophageal cancer was assessed.METHODS:A retrospective study of ten patients with locally advanced esophageal cancer who underwent concurrent chemotherapy with IMRT (1) and IGRT (9) was conducted. The gross tumor volume was treated to a median dose of 70Gy (62.4-75Gy).RESULTS:At a median follow-up of 14months (1-39 months), three patients developed local failures, six patients developed distant metastases, and complications occurred in two patients (1 tracheoesophageal fistula, 1 esophageal stricture requiring repeated dilatations). No patients developed grade 3-4 pneumonitis or cardiac complications.CONCLUSIONS:IMRT and IGRT may be effective for the treatment of locally advanced esophageal cancer with acceptable complications.This item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at [email protected]
Validation of a new prognostic index score for disseminated nasopharyngeal carcinoma
Patients with metastatic nasopharyngeal carcinoma have variable survival outcomes. We previously designed a scoring system to better prognosticate these patients. Here, we report results on validation of this new prognostic index score in a separate cohort of patients. Clinical features and laboratory parameters were examined in 172 patients with univariate and multivariate analyses and a numerical score was derived for each independent prognostic variable. Significant independent prognostic variables and their scores assigned included poor performance status (score 5), haemoglobin <12 g dl−1 (score 4) and disease-free interval (DFI) (DFI⩽6 months (score 10) or metastases at initial diagnosis (score 1)). Maximum score was 19 and patients stratified into three prognostic groups: good, 0–3; intermediate, 4–8; poor, ⩾9. When applied to a separate cohort of 120 patients, 59 patients were good, 43 intermediate and 18 poor prognosis, with median survivals of 19.6 (95% CI 16.1, 23.1), 14.3 (95% CI 12.3, 16.2) and 7.9 (95% CI 6.6, 9.2) months, respectively. (logrank test: P=0.003). We have validated a new prognostic score with factors readily available in the clinics. This simple score will prove useful as a method to prognosticate and stratify patients as well as to promote consistent reporting among clinical trials
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