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1.
J Med Radiat Sci ; 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39332941

RESUMEN

INTRODUCTION: In radiotherapy for head and neck cancer, a mask is used to immobilise the head and shoulders. An open mask that does not cover the face is expected to cause less anxiety, but there is need to further investigate the patients' experience of open versus closed masks. Therefore, the aim of this study is to evaluate patient preferences for open or closed masks and whether an open mask can reduce discomfort and anxiety for patients. METHODS: Twenty participants were treated in alternating weeks using open and closed masks. Their distress was evaluated through semi-structured interviews and patient-reported outcome measures. RESULTS: When using the open mask, it took longer to position the patient correctly. The closed mask felt more confining and could induce a sense of claustrophobia. Participants employed both internal and external strategies to cope with the stressful situation. The Hospital Anxiety and Depression Scale (HADS) showed a significant reduction in anxiety over time during the treatment period, but no significant difference between the masks. When participants chose which mask to use for the final treatments, 12 chose the open mask, while 8 chose the closed mask. In addition to the 20 analysed participants, two participants withdrew from the study because they could only tolerate the open mask, one due to anxiety and the other due to swelling. CONCLUSIONS: The open mask seems to provide a less confined experience but may lead to greater difficulties in achieving the correct treatment position. While both masks can be viable options for most patients, some cannot tolerate closed masks but do tolerate open masks.

2.
Proc Natl Acad Sci U S A ; 119(38): e2204038119, 2022 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-36095178

RESUMEN

Mechanistic details of the signal recognition particle (SRP)-mediated insertion of membrane proteins have been described from decades of in vitro biochemical studies. However, the dynamics of the pathway inside the living cell remain obscure. By combining in vivo single-molecule tracking with numerical modeling and simulated microscopy, we have constructed a quantitative reaction-diffusion model of the SRP cycle. Our results suggest that the SRP-ribosome complex finds its target, the membrane-bound translocon, through a combination of three-dimensional (3D) and 2D diffusional search, together taking on average 750 ms. During this time, the nascent peptide is expected to be elongated only 12 or 13 amino acids, which explains why, in Escherichia coli, no translation arrest is needed to prevent incorrect folding of the polypeptide in the cytosol. We also found that a remarkably high proportion (75%) of SRP bindings to ribosomes occur in the cytosol, suggesting that the majority of target ribosomes bind SRP before reaching the membrane. In combination with the average SRP cycling time, 2.2 s, this result further shows that the SRP pathway is capable of targeting all substrate ribosomes to translocons.


Asunto(s)
Proteínas de Escherichia coli , Escherichia coli , Ribosomas , Partícula de Reconocimiento de Señal , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Cinética , Redes y Vías Metabólicas , Péptidos/química , Péptidos/metabolismo , Pliegue de Proteína , Ribosomas/metabolismo , Partícula de Reconocimiento de Señal/metabolismo
3.
Environ Sci Technol ; 56(7): 4620-4631, 2022 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-35290040

RESUMEN

In permafrost peatlands, up to 20% of total organic carbon (OC) is bound to reactive iron (Fe) minerals in the active layer overlying intact permafrost, potentially protecting OC from microbial degradation and transformation into greenhouse gases (GHG) such as CO2 and CH4. During the summer, shifts in runoff and soil moisture influence redox conditions and therefore the balance of Fe oxidation and reduction. Whether reactive iron minerals could act as a stable sink for carbon or whether they are continuously dissolved and reprecipitated during redox shifts remains unknown. We deployed bags of synthetic ferrihydrite (FH)-coated sand in the active layer along a permafrost thaw gradient in Stordalen mire (Abisko, Sweden) over the summer (June to September) to capture changes in redox conditions and quantify the formation and dissolution of reactive Fe(III) (oxyhydr)oxides. We found that the bags accumulated Fe(III) under constant oxic conditions in areas overlying intact permafrost over the full summer season. In contrast, in fully thawed areas, conditions were continuously anoxic, and by late summer, 50.4 ± 12.8% of the original Fe(III) (oxyhydr)oxides were lost via dissolution. Periodic redox shifts (from 0 to +300 mV) were observed over the summer season in the partially thawed areas. This resulted in the dissolution and loss of 47.2 ± 20.3% of initial Fe(III) (oxyhydr)oxides when conditions are wetter and more reduced, and new formation of Fe(III) minerals (33.7 ± 8.6% gain in comparison to initial Fe) in the late summer under more dry and oxic conditions, which also led to the sequestration of Fe-bound organic carbon. Our data suggest that there is seasonal turnover of iron minerals in partially thawed permafrost peatlands, but that a fraction of the Fe pool remains stable even under continuously anoxic conditions.


Asunto(s)
Hielos Perennes , Compuestos Férricos/metabolismo , Hierro/metabolismo , Oxidación-Reducción , Estaciones del Año , Suelo
4.
Anticancer Res ; 41(7): 3489-3498, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34230144

RESUMEN

BACKGROUND/AIM: Previous studies of node-negative oral squamous cell carcinoma have shown a benefit of elective neck dissection compared to observation. Evidence for radiotherapy as single-modality elective treatment of the node-negative neck is so far lacking. PATIENTS AND METHODS: In a retrospective material of 420 early-stage oral cancers from 2000 to 2016, overall survival, disease-free survival, and regional relapse-free survival were calculated with the Kaplan-Meier method. RESULTS: At five years, overall survival was 59.7%, disease-specific survival was 77.2%, and regional relapse-free survival was 83.5%. Among those with adjuvant treatment of the neck after surgery of T1-T2 tumours during 2009-2016, regional relapse-free survival at five years was 85.7% for elective radiotherapy of the neck and 87.4% for elective neck dissection. CONCLUSION: Elective radiotherapy to the neck with a modern technique and adequate dose might be an alternative to neck dissection for patients with early-stage oral squamous cell cancer.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Neoplasias de la Boca/radioterapia , Carcinoma de Células Escamosas de Cabeza y Cuello/radioterapia , Anciano , Supervivencia sin Enfermedad , Femenino , Humanos , Metástasis Linfática/radioterapia , Masculino , Persona de Mediana Edad , Cuello/efectos de la radiación , Disección del Cuello/métodos , Recurrencia Local de Neoplasia/radioterapia , Oncología por Radiación/métodos , Estudios Retrospectivos
5.
J Contemp Brachytherapy ; 13(3): 245-253, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34122563

RESUMEN

PURPOSE: Until now, most long-term results for brachytherapy only has been published for low-dose-rate (LDR) seeds. Due to radiobiology reasons, high-dose-rate (HDR) mono-brachytherapy is of growing interest. The aim of the study was to report long-term biochemical control rate and toxicities with HDR monotherapy. MATERIAL AND METHODS: This was a retrospective single-institution experience, including 229 men, clinically staged T1c-T2b, Gleason 3 + 3 (prostate specific antigen (PSA) ≤ 15), or Gleason 3 + 4 (PSA ≤ 10), consecutively treated between 2004 and 2012 with HDR brachytherapy alone, using three different fractionation schedules of 92-95 Gy (EQD(2), α/ß = 3). Group 4F (n = 19) had a single implant of 9.5 Gy in four fractions over 2 days. Group 3F (n = 107) had three separate implants of 11 Gy over 4 weeks. Group 2F (n = 103) had two implants of 14 Gy over 2 weeks. No adjuvant hormonal therapy was allowed. RESULTS: For 4F, 3F, and 2F study groups, median follow-up was 10.2, 7.1, and 6.1 years, respectively, and biochemical failure rate was 10.5%, 4.7%, and 14.6%, respectively. Early and late side effects were followed with common terminology criteria version 2.0 and patient-reported questionnaires. There were a temporary acute urethral toxicity increase, 1-2 grades over baseline lower urinary tract symptoms (LUTS), which usually recovered. About 1/3 of the patients had a remaining one grade over baseline LUTS. Severe grade 3-4 toxicity were only found in 3.5% of patients. No rectal toxicity was observed. Erectile dysfunction (ED) was depending on age and erectile function before treatment. In patients without ED before the treatment, we found a complete ED in 21% of men at the last follow-up. CONCLUSIONS: In the present study, HDR mono-brachytherapy was found to be an effective treatment, with mild long-term side effects difficult to differentiate from aging effects. There were no significant differences in PSA regression, PSA failure rate, and toxicity between the different fraction schedules.

6.
Anticancer Res ; 39(1): 285-289, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30591470

RESUMEN

BACKGROUND: This was a validation study of a regional register of oral cancer in Örebro, Sweden. The purpose was to assess the rate of errors in baseline, and treatment, and the completeness and accuracy of data on recurrences. MATERIALS AND METHODS: A total of 653 cases with squamous cell cancer in the oral cavity were identified from the register. A randomized sample of 73 (11%) was selected, and a set of relevant data was compared to medical records. RESULTS: Data on patient and tumour characteristics showed high accuracy, with 98% correct data and more than 99% of treatment data were correct. Follow-up data had a higher rate of errors, with 23% of recurrences not recorded, 13.6% misclassified, and 9.1% of cases showing errors in timing of the recurrence. CONCLUSION: data concerning patients, tumour status, and treatment in the Regional Head and Neck Register in Örebro are highly accurate. However, the follow-up data contain a higher rate of errors, that must be taken into consideration when evaluating outcome after treatment.


Asunto(s)
Errores Diagnósticos , Neoplasias de Cabeza y Cuello/diagnóstico , Boca/patología , Neoplasias de Células Escamosas/diagnóstico , Adulto , Anciano , Femenino , Neoplasias de Cabeza y Cuello/epidemiología , Neoplasias de Cabeza y Cuello/patología , Humanos , Masculino , Oncología Médica , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/patología , Neoplasias de Células Escamosas/epidemiología , Neoplasias de Células Escamosas/patología , Suecia
7.
Lung Cancer ; 122: 180-186, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30032828

RESUMEN

OBJECTIVES: Concurrent chemoradiotherapy is the mainstay treatment for NSCLC stage III disease. To investigate whether radiation dose escalation based on individual normal tissue constraints can improve outcome, the Swedish lung cancer study group launched this randomized phase II trial. MATERIALS AND METHODS: NSCLC patients with stage III disease, good performance status (0-1) and adequate lung function (FEV1 > 1.0 L and CO diffusion capacity > 40%) received three cycles of cisplatin (75 mg/m2 day 1) and vinorelbine (25 mg/m2 day 1 and 8) every third week. Radiotherapy started concurrently with the second cycle, with either 2 Gy daily, 5 days a week, to 68 Gy (A) or escalated therapy (B) based on constraints to the spinal cord, esophagus and lungs up to 84 Gy by adding an extra fraction of 2 Gy per week. RESULTS: A pre-planned safety analysis revealed excessive toxicity and decreased survival in the escalated arm, and the study was stopped. Thirty-six patients were included during 2011-2013 (56% male, 78% with adenocarcinoma, 64% with PS 0 and 53% with stage IIIB). The median progression-free survival (PFS) and overall survival (OS) were 11 and 17 months in arm B compared to the encouraging results of 28 and 45 months in the standard arm. The 1- and 3-year survival rates were 56% and 33% (B) and 72% and 56% (A), respectively. There were seven toxicity-related deaths due to esophageal perforations and pneumonitis: five in the escalated group and two with standard treatment. CONCLUSION: Dose-escalated concurrent chemoradiotherapy to 84 Gy to primary tumor and nodal disease is hazardous, with a high risk of excessive toxicity, whereas modern standard dose chemoradiotherapy with proper staging given in the control arm shows a promising outcome with a median survival of 45 months and a 3-year survival of 56% (NCT01664663).


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/terapia , Quimioradioterapia , Perforación del Esófago/etiología , Esófago/efectos de los fármacos , Neoplasias Pulmonares/terapia , Neumonía/etiología , Dosificación Radioterapéutica , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Quimioradioterapia/efectos adversos , Cisplatino/uso terapéutico , Terminación Anticipada de los Ensayos Clínicos , Perforación del Esófago/mortalidad , Esófago/patología , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/mortalidad , Persona de Mediana Edad , Estadificación de Neoplasias , Neumonía/mortalidad , Análisis de Supervivencia , Suecia , Resultado del Tratamiento , Vinblastina/uso terapéutico , Vinorelbina/uso terapéutico
9.
Radiother Oncol ; 118(2): 335-41, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26777124

RESUMEN

BACKGROUND AND PURPOSE: Health related quality of life (HRQoL) was assessed in the randomised, prospective ARTSCAN study comparing conventional radiotherapy (CF) with accelerated radiotherapy (AF) for head and neck cancer. MATERIAL AND METHODS: 750 patients with squamous cell carcinoma (of any grade and stage) in the oral cavity, oro-, or hypopharynx or larynx (except T1-2, N0 glottic carcinoma) without distant metastases were randomised to either conventional fractionation (2 Gy/day, 5 days/week in 49 days, total dose 68 Gy) or accelerated fractionation (1.1+2.0 Gy/day, 5 days/week in 35 days, total dose 68 Gy). HRQoL was assessed with EORTC QLQ-C30, QLQ-H&N35 and HADS at baseline, at end of radiotherapy (eRT) and at 3 and 6 months and 1, 2 and 5 years after start of treatment. RESULTS: The AF group reported HRQoL was significantly lower at eRT and at 3 months for most symptoms, scales and functions. Few significant differences were noted between the groups at 6 months and 5 years. Scores related to functional oral intake never reached baseline. CONCLUSION: In comparison to CF, AF has a stronger adverse effect on HRQoL in the acute phase.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeza y Cuello/radioterapia , Calidad de Vida , Adulto , Anciano , Anciano de 80 o más Años , Fraccionamiento de la Dosis de Radiación , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
10.
Radiother Oncol ; 117(1): 99-105, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26427805

RESUMEN

BACKGROUND AND PURPOSE: This report contains the mature five-year data from the Swedish ARTSCAN trial including information on the influence of p16 positivity (p16+) for oropharyngeal cancers. MATERIAL AND METHODS: Patients with previously untreated squamous cell carcinoma without distant metastases of the oral cavity, oropharynx, larynx (except T1-2, N0 glottic cancers) and hypopharynx were included. Patients were randomised between accelerated fractionation (AF) (1.1Gy+2Gy per day, 5days/week for 4.5weeks, total dose 68Gy) and conventional fractionation (CF) (2Gy per day, 5days/week for 7weeks, total dose 68Gy). Human papillomavirus (HPV)-associated p16-expression was assessed retrospectively in tumour tissues from patients with oropharyngeal carcinoma. RESULTS: There was no significant difference in loco-regional control (LRC) between AF and CF (log-rank test p=0.75). LRC at 5years was 65.5% for AF and 64.9% for CF. Overall survival (OS) was similar in both arms (p=0.99). The estimated cancer specific survival (CSS) at 5years was 62.2% (AF) and 63.3% (CF) (p=0.99). 206 specimens were analysed for p16 with 153 specimens (74%) identified as p16+. P16 status did not discriminate for response to AF vs. CF with regard to LRC, OS or CSS. Patients with p16+ tumours had a statistically significant better overall prognosis compared with p16- tumours. CONCLUSION: This update confirms the results of the 2-year report. We failed to identify a positive effect resulting from AF with regards to LRC, OS and CSS. The addition of information on the HPV-associated p16 overexpression did not explain this lack of effect.


Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeza y Cuello/radioterapia , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/virología , Fraccionamiento de la Dosis de Radiación , Femenino , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/virología , Papillomavirus Humano 16/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Orofaríngeas/patología , Neoplasias Orofaríngeas/radioterapia , Neoplasias Orofaríngeas/virología , Infecciones por Papillomavirus/complicaciones , Pronóstico , Estudios Retrospectivos , Carcinoma de Células Escamosas de Cabeza y Cuello
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