scholarly journals PPARs in Irradiation-Induced Gastrointestinal Toxicity

PPAR Research ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Christine Linard ◽  
Maâmar Souidi
Keyword(s):  
Normal Tissue ◽  
Treatment Time ◽  
Therapeutic Benefit ◽  
Gastrointestinal Toxicity ◽  
Overall Treatment Time ◽  
Inflammatory Reactions ◽  
Normal Tissues ◽  
Inflammatory Processes ◽  
Patients Experience ◽  
Abdominal Irradiation

The use of radiation therapy to treat cancer inevitably involves exposure of normal tissues. Although the benefits of this treatment are well established, many patients experience distressing complications due to injury to normal tissue. These side effects are related to inflammatory processes, and they decrease therapeutic benefit by increasing the overall treatment time. Emerging evidence indicates that PPARs and their ligands are important in the modulation of immune and inflammatory reactions. This paper discusses the effects of abdominal irradiation on PPARs, their role and functions in irradiation toxicity, and the possibility of using their ligands for radioprotection.

Altered Fractionation in Radiotherapy

1998 ◽  
Vol 84 (2) ◽  
pp. 155-159 ◽  
Author(s):  
Riccardo Valdagni
Keyword(s):  
Treatment Time ◽  
Clinical Results ◽  
Therapeutic Benefit ◽  
Phase Iii ◽  
Overall Treatment Time ◽  
Conventional Fractionation ◽  
Normal Tissues ◽  
Normal Tissue Damage ◽  
Altered Fractionation ◽  
Cell Repopulation

Differences between late-responding (slowly proliferating) normal tissues and early-responding (rapidly proliferating) normal tissues and tumor cells and the event of tumor cell repopulation occurring during treatment have essentially led to the development of altered fractionation schemes. Altered fractionation regimens mainly refer to schedules utilising two or more (small dose) fractions per day for part of or for the entire treatment course. It must be underlined that a true standard or conventional fractionation regimen does not exist: no schedule is universally recognised as the standard of reference to be compared with. However, continental European and U.S. conventional regimens are the considered control arm with which the new experimental regimens have to be compared. For this reason they are generally recognised as the standards. The basic rationale for hyperfractionated or accelerated regimens respectively lies in the possibility (a) to deliver higher total doses reducing late-responding normal tissue damage, (b) to deliver total doses in a reduced overall treatment time to defeat tumor clonogen repopulation. Multiple fractions per day should not be delivered with interfraction intervals smaller than 6 hours. Clinical results of phase I-II and limited but convincing phase III randomised trials suggest that a therapeutic benefit can be achieved with new altered regimens.

The PACE trial: International randomised study of laparoscopic prostatectomy vs. stereotactic body radiotherapy (SBRT) and standard radiotherapy vs. SBRT for early stage organ-confined prostate cancer.

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. TPS153-TPS153 ◽  
Author(s):  
Kirsty Morrison ◽  
Alison Tree ◽  
Vincent Khoo ◽  
Nicholas John Van As ◽  
Keyword(s):  
Prostate Cancer ◽  
Stereotactic Body Radiotherapy ◽  
Treatment Time ◽  
Early Stage ◽  
Treatment Options ◽  
Therapeutic Benefit ◽  
Phase Iii ◽  
Overall Treatment Time ◽  
Multicentre Phase ◽  
Randomised Study

TPS153 Background: The development of Stereotactic Body Radiotherapy (SBRT) has provided a further treatment option for early stage prostate cancer. In addition to the benefits of an overall treatment time reduction, profound hypofractionation could result in therapeutic gain given the radiobiology of prostate cancer. Evidence suggests SBRT to be safe and effective; however randomised data is lacking comparing outcomes with standard treatment options. Aim: To assess whether SBRT offers therapeutic benefit in comparison to prostatectomy or standard radiotherapy. Methods: The PACE trial is an international multicentre phase III trial, comprising two parallel randomisation processes. Within PACE A, potential surgical candidates are randomised between radical prostatectomy and SBRT (36.25 Gy in 5 fractions). In PACE B, randomisation is between standard radiotherapy (78Gy in 39 fractions or 62Gy in 20 fractions) and SBRT (36.35Gy in 5 fractions). SBRT can be delivered using Cyberknife or gantry based techniques. Patients with low or intermediate risk prostate cancer are eligible for the trial, and are treated without the use androgen deprivation therapy. Follow up is for a period of 10 years. The aim is to recruit 234 patients to PACE A (117 in each arm) and 858 patients to PACE B (429 patients in each arm). Primary Objectives: PACE A: To determine whether there is improved quality of life after SBRT compared with surgery at 2 years post treatment, using EPIC score to measure urinary incontinence and bowel bother. PACE B: to determine whether SBRT is non-inferior to surgery in terms of freedom from biochemical/clinical failure at 5 years from randomisation. Progress: PACE A has been slower to recruit than anticipated due to the difficulties of a surgery versus radiotherapy randomisation. However, it is expected to reach target accrual, having recruited 57 patients from 3 centres. In contrast, PACE B is recruiting exceptionally well, open in 40 centres, and as of October 2017 recruited 762 patients. Accrual target is expected to be reached by the end of 2017. Clinical trial information: NCT01584258.

Strahlenwirkung am Normalgewebe

2010 ◽  
Vol 49 (S 01) ◽  
pp. S53-S58 ◽  
Author(s):  
W. Dörr
Keyword(s):  
Radiation Exposure ◽  
Normal Tissue ◽  
Radiation Effects ◽  
A Priori ◽  
Cell Loss ◽  
Turnover Time ◽  
Complete Healing ◽  
Internal Radiotherapy ◽  
Normal Tissues ◽  
Chronic Radiation

SummaryThe curative effectivity of external or internal radiotherapy necessitates exposure of normal tissues with significant radiation doses, and hence must be associated with an accepted rate of side effects. These complications can not a priori be considered as an indication of a too aggressive therapy. Based on the time of first diagnosis, early (acute) and late (chronic) radiation sequelae in normal tissues can be distinguished. Early reactions per definition occur within 90 days after onset of the radiation exposure. They are based on impairment of cell production in turnover tissues, which in face of ongoing cell loss results in hypoplasia and eventually a complete loss of functional cells. The latent time is largely independent of dose and is defined by tissue biology (turnover time). Usually, complete healing of early reactions is observed. Late radiation effects can occur after symptom-free latent times of months to many years, with an inverse dependence of latency on dose. Late normal tissue changes are progressive and usually irreversible. They are based on a complex interaction of damage to various cell populations (organ parenchyma, connective tissue, capillaries), with a contribution from macrophages. Late effects are sensitive for a reduction in dose rate (recovery effects).A number of biologically based strategies for protection of normal tissues or for amelioration of radiation effects was and still is tested in experimental systems, yet, only a small fraction of these approaches has so far been introduced into clinical studies. One advantage of most of the methods is that they may be effective even if the treatment starts way after the end of radiation exposure. For a clinical exploitation, hence, the availability of early indicators for the progression of subclinical damage in the individual patient would be desirable. Moreover, there is need to further investigate the molecular pathogenesis of normal tissue effects in more detail, in order to optimise biology based preventive strategies, as well as to identify the precise mechanisms of already tested approaches (e. g. stem cells).

Resveratrol as an Adjuvant for Normal Tissues Protection and Tumor Sensitization

2020 ◽  
Vol 20 (2) ◽  
pp. 130-145 ◽  
Author(s):  
Keywan Mortezaee ◽  
Masoud Najafi ◽  
Bagher Farhood ◽  
Amirhossein Ahmadi ◽  
Dheyauldeen Shabeeb ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Cancer Treatment ◽  
Cancer Cells ◽  
Clinical Studies ◽  
Normal Tissue ◽  
Medical Science ◽  
Treatment Modalities ◽  
Radiation Toxicity ◽  
Normal Tissues ◽  
Normal Tissue Toxicity

Cancer is one of the most complicated diseases in present-day medical science. Yearly, several studies suggest various strategies for preventing carcinogenesis. Furthermore, experiments for the treatment of cancer with low side effects are ongoing. Chemotherapy, targeted therapy, radiotherapy and immunotherapy are the most common non-invasive strategies for cancer treatment. One of the most challenging issues encountered with these modalities is low effectiveness, as well as normal tissue toxicity for chemo-radiation therapy. The use of some agents as adjuvants has been suggested to improve tumor responses and also alleviate normal tissue toxicity. Resveratrol, a natural flavonoid, has attracted a lot of attention for the management of both tumor and normal tissue responses to various modalities of cancer therapy. As an antioxidant and anti-inflammatory agent, in vitro and in vivo studies show that it is able to mitigate chemo-radiation toxicity in normal tissues. However, clinical studies to confirm the usage of resveratrol as a chemo-radioprotector are lacking. In addition, it can sensitize various types of cancer cells to both chemotherapy drugs and radiation. In recent years, some clinical studies suggested that resveratrol may have an effect on inducing cancer cell killing. Yet, clinical translation of resveratrol has not yielded desirable results for the combination of resveratrol with radiotherapy, targeted therapy or immunotherapy. In this paper, we review the potential role of resveratrol for preserving normal tissues and sensitization of cancer cells in combination with different cancer treatment modalities.

scholarly journals Apoptosis and inflammation

1995 ◽  
Vol 4 (1) ◽  
pp. 5-15 ◽  
Author(s):  
C. Haanen ◽  
I. Vermes
Keyword(s):  
Cell Death ◽  
Inflammatory Reaction ◽  
Inflammatory Diseases ◽  
Apoptotic Cell ◽  
Cell Damage ◽  
Target Cells ◽  
Apoptotic Bodies ◽  
Accidental Injury ◽  
Inflammatory Reactions ◽  
Inflammatory Processes

During the last few decades it has been recognized that cell death is not the consequence of accidental injury, but is the expression of a cell suicide programme. Kerr et al. (1972) introduced the term apoptosis. This form of cell death is under the influence of hormones, growth factors and cytokines, which depending upon the receptors present on the target cells, may activate a genetically controlled cell elimination process. During apoptosis the cell membrane remains intact and the cell breaks into apoptotic bodies, which are phagocytosed. Apoptosis, in contrast to necrosis, is not harmful to the host and does not induce any inflammatory reaction. The principal event that leads to inflammatory disease is cell damage, induced by chemical/physical injury, anoxia or starvation. Cell damage means leakage of cell contents into the adjacent tissues, resulting in the capillary transmigration of granulocytes to the injured tissue. The accumulation of neutrophils and release of enzymes and oxygen radicals enhances the inflammatory reaction. Until now there has been little research into the factors controlling the accumulation and the tissue load of granulocytes and their histotoxic products in inflammatory processes. Neutrophil apoptosis may represent an important event in the control of intlamtnation. It has been assumed that granulocytes disintegrate to apoptotic bodies before their fragments are removed by local macrophages. Removal of neutrophils from the inflammatory site without release of granule contents is of paramount importance for cessation of inflammation. In conclusion, apoptotic cell death plays an important role in inflammatory processes and in the resolution of inflammatory reactions. The facts known at present should stimulate further research into the role of neutrophil, eosinophil and macrophage apoptosis in inflammatory diseases.

scholarly journals Intermolar Mandibular Distraction Osteogenesis—A Preliminary Report

2021 ◽  
Vol 11 (9) ◽  
pp. 4118
Author(s):  
Suen A. N. Lie ◽  
Britt H. B. T. Engelen ◽  
Veronique C. M. L. Timmer ◽  
Nico M. P. Vrijens ◽  
Paolo Asperio ◽  
...  
Keyword(s):  
Distraction Osteogenesis ◽  
Treatment Time ◽  
Average Length ◽  
Case Series ◽  
Growth Spurt ◽  
Overall Treatment Time ◽  
Mandibular Distraction ◽  
Mandibular Distraction Osteogenesis ◽  
Root Fractures

Background: Dental Class II is the most common indication for combined orthodontic-orthognathic treatment. Intermolar mandibular distraction osteogenesis (IMDO) treatment was performed during the growth spurt, to avoid surgery at a later age. The aim of this study is to present our first experience with IMDO. Methods: This is a retrospective case series of patients who underwent an IMDO. All patients showed mandibular retrognathism, and orthodontic treatment with functional appliances was not successful. Results: In total, 20 patients (mean age of 14.8 years (SD = 0.9 ys) were included. All patients achieved a Class I occlusion. An average length gain of 9.6 mm (SD = 3.7 mm) was reached. In one patient an abscess occurred. Nine patients presented with root fractures of the second molar; three were lost, one treated endodontically. The average time between insertion and removal of the distractors was 4.6 months (SD = 1.5 mths). In one case a premature consolidation was seen. Conclusion: We achieved satisfactory results with IMDO, although undesirable effects occurred. An advantage is the manageable overall treatment time. Open questions concern the occurrence of root fractures. Furthermore, the question of long-term stability is open. The question of dynamic distraction treatment in relation to temporomandibular joint changes can only be answered in the long term.

Primary Human Liver Cells as Source for Modular Extracorporeal Liver Support - a Preliminary Report

2002 ◽  
Vol 25 (10) ◽  
pp. 1001-1005 ◽  
Author(s):  
I.M. Sauer ◽  
K. Zeilinger ◽  
N. Obermayer ◽  
G. Pless ◽  
A. Grünwald ◽  
...  
Keyword(s):  
Human Liver ◽  
Treatment Time ◽  
Liver Perfusion ◽  
Cell Mass ◽  
Liver Weight ◽  
Liver Cells ◽  
Liver Support ◽  
Overall Treatment Time ◽  
Human Liver Cells ◽  
Extracorporeal Liver Support

Cell-based extracorporeal liver support is an option to assist or replace the failing organ until regeneration or until transplantation can be performed. The use of porcine cells or tumor cell lines is controversial. Primary human liver cells, obtained from explanted organs found to be unsuitable for transplantation, are a desirable cell source as they perform human metabolism and regulation. The Modular Extracorporeal Liver Support (MELS) concept combines different extracorporeal therapy units, tailored to suit the individual and intra-individual clinical needs of the patient. A multi-compartment bioreactor (CellModule) is loaded with human liver cells obtained by 5-step collagenase liver perfusion. A cell mass of 400 g – 600 g enables the clinical application of a liver lobe equivalent hybrid organ. A detoxification module enables single pass albumin-dialysis via a standard high-flux dialysis filter, and continuous venovenuous hemodiafiltration may be included if required. Cells from 54 human livers have been isolated (donor age: 56 ± 13 years, liver weight: 1862 ± 556 g resulting in a viability of 55.0 ± 15.9%). These grafts were not suitable for LTx, due to steatosis (54%), cirrhosis (15%), fibrosis (9%), and other reasons (22%). Out of 36 prepared bioreactors, 10 were clinically used to treat 8 patients with liver failure. The overall treatment time was 7–144 hours. No adverse events were observed. Initial clinical applications of the bioreactor evidenced the technical feasibility and safety of the system.

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