Mathematical medicine and biology : a journal of the IMA最新文献_第8页

On the influence of an equatorial cerclage on closure of posterior retinal detachment 赤道环扎术对后视网膜脱离闭合的影响

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-12-01 DOI: 10.1093/imammb/dqv028

Peinan Ge;William J. Bottega;Jonathan L. Prenner;Howard F. Fine

{"title":"On the influence of an equatorial cerclage on closure of posterior retinal detachment","authors":"Peinan Ge;William J. Bottega;Jonathan L. Prenner;Howard F. Fine","doi":"10.1093/imammb/dqv028","DOIUrl":"10.1093/imammb/dqv028","url":null,"abstract":"A mechanics-based mathematical model of an eye possessing a posterior retinal detachment is presented for the case where an encircling scleral buckle (a cerclage) is sutured around the equator of the eye. The mechanical behaviour of the retina and the globe, both before and after applying the cerclage, is studied. An energy formulation yields the self-consistent equations of equilibrium and boundary conditions of the ocular system, and analytical solutions are established for the scleral buckle, for the globe and for the detached segment of the retina. Results of numerical simulations based on the solutions unveil characteristic behaviour of the ocular system, and demonstrate the influence of the scleral buckle, as well as of the pressure difference between the vitreous cavity and the subretinal space, on the deformation of the eye and on closing the region of retinal detachment. The results indicate that a scleral buckle encircling the equator, normally used for closing retinal tears and associated retinal detachments in the immediate vicinity of the buckle, can have a marked influence on bringing the detached segment of neurosensory retina back into contact with the retinal pigment epithelium, even for detachments at the posterior of the eye.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":"33 4","pages":"417-433"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqv028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33991424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Allee effects in tritrophic food chains: some insights in pest biological control 营养食物链中的狭缝效应:害虫生物防治的一些见解

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-12-01 DOI: 10.1093/imammb/dqv027

Michel Iskin da S. Costa;Lucas dos Anjos

引用次数: 3

Effective equations for anisotropic glioma spread with proliferation: a multiscale approach and comparisons with previous settings 各向异性胶质瘤扩散与增殖的有效方程:多尺度方法和与先前设置的比较

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-12-01 DOI: 10.1093/imammb/dqv030

Christian Engwer;Alexander Hunt;Christina Surulescu

{"title":"Effective equations for anisotropic glioma spread with proliferation: a multiscale approach and comparisons with previous settings","authors":"Christian Engwer;Alexander Hunt;Christina Surulescu","doi":"10.1093/imammb/dqv030","DOIUrl":"10.1093/imammb/dqv030","url":null,"abstract":"Glioma is a common type of primary brain tumour, with a strongly invasive potential, often exhibiting non-uniform, highly irregular growth. This makes it difficult to assess the degree of extent of the tumour, hence bringing about a supplementary challenge for the treatment. It is therefore necessary to understand the migratory behaviour of glioma in greater detail. In this paper, we propose a multiscale model for glioma growth and migration. Our model couples the microscale dynamics (reduced to the binding of surface receptors to the surrounding tissue) with a kinetic transport equation for the cell density on the mesoscopic level of individual cells. On the latter scale, we also include the proliferation of tumour cells via effects of interaction with the tissue. An adequate parabolic scaling yields a convection–diffusion–reaction equation, for which the coefficients can be explicitly determined from the information about the tissue obtained by diffusion tensor imaging (DTI). Numerical simulations relying on DTI measurements confirm the biological findings that glioma spread along white matter tracts.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":"33 4","pages":"435-459"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqv030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33998591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 36

A Green's function method for simulation of time-dependent solute transport and reaction in realistic microvascular geometries 模拟微血管几何中随时间变化的溶质输运和反应的格林函数方法

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-12-01 DOI: 10.1093/imammb/dqv031

Timothy W. Secomb

{"title":"A Green's function method for simulation of time-dependent solute transport and reaction in realistic microvascular geometries","authors":"Timothy W. Secomb","doi":"10.1093/imammb/dqv031","DOIUrl":"10.1093/imammb/dqv031","url":null,"abstract":"A novel theoretical method is presented for simulating the spatially resolved convective and diffusive transport of reacting solutes between microvascular networks and the surrounding tissues. The method allows for efficient computational solution of problems involving convection and non-linear binding of solutes in blood flowing through microvascular networks with realistic 3D geometries, coupled with transvascular exchange and diffusion and reaction in the surrounding tissue space. The method is based on a Green's function approach, in which the solute concentration distribution in the tissue is expressed as a sum of fields generated by time-varying distributions of discrete sources and sinks. As an example of the application of the method, the washout of an inert diffusible tracer substance from a tissue region perfused by a network of microvessels is simulated, showing its dependence on the solute's transvascular permeability and tissue diffusivity. Exponential decay of the washout concentration is predicted, with rate constants that are about 10-30% lower than the rate constants for a tissue cylinder model with the same vessel length, vessel surface area and blood flow rate per tissue volume.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":"33 4","pages":"475-494"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqv031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34236576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 23

Back matter 背景材料

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-09-01

引用次数: 0

Strategy for stochastic dose-rate induced enhanced elimination of malignant tumour without dose escalation 随机剂量率诱导恶性肿瘤增强消除而不增加剂量的策略

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-09-01 DOI: 10.1093/imammb/dqv012

Subhadip Paul;Prasun Kumar Roy

{"title":"Strategy for stochastic dose-rate induced enhanced elimination of malignant tumour without dose escalation","authors":"Subhadip Paul;Prasun Kumar Roy","doi":"10.1093/imammb/dqv012","DOIUrl":"10.1093/imammb/dqv012","url":null,"abstract":"The efficacy of radiation therapy, a primary modality of cancer treatment, depends in general upon the total radiation dose administered to the tumour during the course of therapy. Nevertheless, the delivered radiation also irradiates normal tissues and dose escalation procedure often increases the elimination of normal tissue as well. In this article, we have developed theoretical frameworks under the premise of linear-quadratic-linear (LQL) model using stochastic differential equation and Jensen's inequality for exploring the possibility of attending to the two therapeutic performance objectives in contraposition—increasing the elimination of prostate tumour cells and enhancing the relative sparing of normal tissue in fractionated radiation therapy, within a prescribed limit of total radiation dose. Our study predicts that stochastic temporal modulation in radiation dose-rate appreciably enhances prostate tumour cell elimination, without needing dose escalation in radiation therapy. However, constant higher dose-rate can also enhance the elimination of tumour cells. In this context, we have shown that the sparing of normal tissue with stochastic dose-rate is considerably more than the sparing of normal tissue with the equivalent constant higher dose-rate. Further, by contrasting the stochastic dose-rate effects under LQL and linear-quadratic (LQ) models, we have also shown that the LQ model over-estimates stochastic dose-rate effect in tumour and under-estimates the stochastic dose-rate effect in normal tissue. Our study indicates the possibility of utilizing stochastic modulation of radiation dose-rate for designing enhanced radiation therapy protocol for cancer.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":"33 3","pages":"319-328"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqv012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33365615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Front matter 前页

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-09-01

引用次数: 0

On the stability of a spherical tumour 球形肿瘤的稳定性

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-09-01 DOI: 10.1093/imammb/dqv016

George Dassios;Vasiliki Christina Panagiotopoulou

引用次数: 1

A coupled non-Fickian model of a cardiovascular drug delivery system 心血管给药系统的耦合非菲克模型

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-09-01 DOI: 10.1093/imammb/dqv023

J. A. Ferreira;J. Naghipoor;Paula de Oliveira

引用次数: 12

Extreme protraction for low-grade gliomas: theoretical proof of concept of a novel therapeutical strategy 低级别胶质瘤的极端延长:一种新的治疗策略概念的理论证明

Mathematical medicine and biology : a journal of the IMA Pub Date : 2016-09-01 DOI: 10.1093/imammb/dqv017

Victor M. Pérez-García;Luis A. Pérez-Romasanta

{"title":"Extreme protraction for low-grade gliomas: theoretical proof of concept of a novel therapeutical strategy","authors":"Victor M. Pérez-García;Luis A. Pérez-Romasanta","doi":"10.1093/imammb/dqv017","DOIUrl":"10.1093/imammb/dqv017","url":null,"abstract":"Grade II gliomas are slowly growing primary brain tumours that affect mostly young patients and become fatal after a variable time period. Current clinical handling includes surgery as first-line treatment. Cytotoxic therapies (radiotherapy RT or chemotherapy QT) are used initially only for patients having a bad prognosis. Therapies are administered following the ‘maximum dose in minimum time’ principle, which is the same schedule used for high-grade brain tumours. Using mathematical models describing the growth of these tumours in response to radiotherapy, we find that an extreme protraction therapeutical strategy, i.e. enlarging substantially the time interval between RT fractions, may lead to better tumour control. Explicit formulas are found providing the optimal spacing between doses in a very good agreement with the simulations of the full 3D mathematical model approximating the tumour spatiotemporal dynamics. This idea, although breaking the well-established paradigm, has biological meaning since, in these slowly growing tumours, it may be more favourable to treat the tumour as the tumour cells leave the quiescent compartment and move into the cell cycle.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":"33 3","pages":"253-271"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqv017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33301568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2