Search results for "Tumor growth"
showing 10 items of 25 documents
Caretakers and Gatekeepers
2017
It has now been generally accepted that the genes responsible for familial cancer syndromes can be divided into two categories, known as caretakers and gatekeepers. Caretakers are genes that control the maintenance of the genetic information integrity in each cell while gatekeepers are those genes which directly regulate tumor growth, codifying for proteins which either stimulate or inhibit proliferation, differentiation or apoptosis. Keywords: gatekeeper genes; caretaker genes; tumor suppressor genes; cell cycle; hereditary syndromes
The Role of Mathematical Models in Immuno-Oncology: Challenges and Future Perspectives
2021
Immuno-oncology (IO) focuses on the ability of the immune system to detect and eliminate cancer cells. Since the approval of the first immune checkpoint inhibitor, immunotherapies have become a major player in oncology treatment and, in 2021, represented the highest number of approved drugs in the field. In spite of this, there is still a fraction of patients that do not respond to these therapies and develop resistance mechanisms. In this sense, mathematical models offer an opportunity to identify predictive biomarkers, optimal dosing schedules and rational combinations to maximize clinical response. This work aims to outline the main therapeutic targets in IO and to provide a description …
Vascular patterns provide therapeutic targets in aggressive neuroblastic tumors
2016
// Irene Tadeo 1 , Gloria Bueno 2 , Ana P. Berbegall 1 , M. Milagro Fernandez-Carrobles 2 , Victoria Castel 3 , Marcial Garcia-Rojo 4 , Samuel Navarro 1 , Rosa Noguera 1 1 Pathology Department, Medical School, University of Valencia, INCLIVA, 46010 Valencia, Spain 2 VISILAB, E.T.S. Ingenieros Industriales, University of Castilla-La Mancha, 13071 Ciudad Real, Spain 3 Pediatric Oncology Unit, University and Polytechnic Hospital La Fe, 46026 Valencia, Spain 4 Department of Pathology, Hospital de Jerez de la Frontera, 11407 Jerez de la Frontera, Cadiz, Spain Correspondence to: Rosa Noguera Salva, e-mail: rnoguera@uv.es Keywords: extracellular matrix, blood vessels, capillaries, sinusoids, neuro…
Itinéraire d’un agent double
2016
Protein S-nitrosylation is now recognized as a ubiquitous regulatory mechanism. Like any post-translational modifications, S-nitrosylation is critical for the control of numerous cellular processes. It is now clear that S-nitrosylation is playing a double game, enhancing or inhibiting the tumor growth or the induction of cell death. Thanks to research aimed at demonstrating NO cytotoxic effects, new therapeutic strategies based on NO donor drugs have emerged. Although therapeutic NO donors can target a large number of proteins, the cellular mechanism is still not fully understood. This review reflects the current state of knowledge on S-nitrosylated proteins that take part of the oncogenic …
Competing species system as a qualitative model of radiation therapy
2016
To examine complex features of tumor dynamics we analyze a competing-species lattice model that takes into account the competition for nutrients or space as well as interaction with therapeutic factors such as drugs or radiation. Our model might be interpreted as a certain prey–predator system having three trophic layers: (i) the basal species that might be interpreted as nutrients; (ii) normal and tumor cells that consume nutrients, and (iii) therapeutic factors that might kill either nutrient, normal or tumor cells. Using a wide spectrum of parameters we examined survival of our species and tried to identify the corresponding dynamical regimes. It was found that the radiotherapy influence…
Management of intralabyrinthine schwannomas
2006
Abstract Objectives Our protocol to manage the intralabyrinthine schwannoma (ILS). Methods Retrospective chart review of 7 consecutive patients managed for ILS. Results Five patients underwent surgical removal of the lesions and none experienced significant complications or recurrent disease. One patient refused surgical treatment and was closely followed by serial MRI scans with no signs of tumor growth. One patient is presently managed conservatively due to a good hearing. Conclusions Diagnosis of ILS is based on high resolution MRI scans and should be included in the differential diagnosis of patients investigated for cochleovestibular symptoms. Treatment modality of ILS is controversial…
Effect of Kernels Used for the Reconstruction of MDCT Datasets on the Semi-Automated Segmentation and Volumetry of Liver Lesions
2014
Purpose: To evaluate the effect of different reconstruction kernels on the semi-automated segmentation of liver lesions in MDCT. Materials and Methods: A total 62 liver lesions were measured by three independent radiologists with the semi-automated segmentation software Oncology-Prototype (Fraunhofer MEVIS, Siemens Healthcare, Germany) using MDCT datasets (3-mm slice thickness, 2-mm increment) reconstructed with standard, soft and detailed kernels (Philips B, A and D). To ensure objective measurements, only lesions with satisfactory initial segmentation were included, and manual correction was not used. The effective diameter and volume were recorded for each lesion. Segmentation in the sof…
Predictive Power of the Tumor Oxygenation Status
1999
In most solid tumors the tissue pO2 status is poorer than in normal tissue at the site of tumor growth (for reviews see Vaupel et al., 1996, 1998; Vaupel and Hoeckel, 1998). Peculiarities of tumor tissue oxygenation can mainly be attributed to characteristic structural and functional abnormalities of the tumor microcirculation (perfusion-limited O2 delivery), to a deterioration of the diffusion-geometry (diffusion-limited O2 delivery), and—in some cases—to a reduced O2 carrying capacity of the blood due to tumor-associated anemia.
Chemokine Expression Is Involved in the Vascular Neogenesis of Ewing Sarcoma: A Preliminary Analysis of the Early Stages of Angiogenesis in a Xenogra…
2018
Background Ewing sarcoma (EWS) is the second most common bone cancer in pediatric patients. Angiogenesis is a major factor for tumor growth and metastasis. Our aim was to carry out a histological, immunohistochemical, and molecular characterization of the neovascularization established between xenotransplanted tumors and the host during the initial phases of growth in nude mice in three angiogenesis experiments (ES2, ES3, and ES4). Methods The original human EWS were implanted subcutaneously on the backs of three nude mice. Tumor pieces 3 mm–4 mm in size from early passages of Nu432, Nu495, and Nu471 were also implanted subcutaneously on the backs of three sets (ES2, ES3, and ES4) of athymi…
Effects of tumor necrosis factor-alpha on tumor blood flow and hyperthermic treatment.
1989
The impact of recombinant human tumor necrosis factor-alpha (rhTNF-alpha), given alone or in combination with local hyperthermia, on perfusion and growth of a moderately rhTNF-alpha-sensitive rat tumor (DS-carcinosarcoma) was investigated. DS-carcinosarcomas were implanted into the hind foot dorsum of Sprague-Dawley rats. Tumor blood flow (TBF) was measured with the krypton-85 clearance technique. Treatment with either tumor necrosis factor-alpha (0.1-1.0 mg/kg) or hyperthermia (43.3 and 44.3 degrees C, 40 min) can decrease the perfusion of malignant tumors. The TBF reduction was fully established 2 h after rhTNF-alpha injection and lasted for at least 4 h. The application of local hyperthe…