Search results for "Normal tissue"

2019

Purpose: Clear resection margins are paramount for good outcome in children undergoing solid tumor resections. Multiphoton microscopy (MPM) can provide high-resolution, real-time, intraoperative microscopic images of tumor tissue. Objective: This prospective international multicenter study evaluates the diagnostic accuracy, feasibility, and interobserver congruence of MPM in diagnosing solid pediatric tissue and tumors for the first time. Material and methods: Representative fresh sections from six different neonatal solid tissues (liver, lung, kidney, adrenal gland, heart muscle, testicle) and two types of typical pediatric solid tumors (neuroblastoma, rhabdomyosarcoma) with adjacent nonne…

A Novel Radiotherapeutic Approach to Treat Bulky Metastases Even From Cutaneous Squamous Cell Carcinoma: Its Rationale and a Look at the Reliability …

2022

IntroductionMetastatic cutaneous squamous cell carcinoma (cSCC) is a very rare condition. The lack of definition of an oligometastatic subgroup means that there is no consensus for its treatment, unlike the mucosal head and neck counterpart. Like the latter, the cutaneous form is able to develop bulky tumor masses. When this happens, the classic care approach is just for palliative intent due to a likely unfavorable benefit–risk balance typical of aggressive treatments. Here we proposed a novel radiotherapy (RT) technique to treat bulky metastases from cSCC in the context of an overall limited tumor burden and tried to explain its clinical outcome by the currently available mathematical rad…

Evidence for characteristic vascular patterns in solid tumours: quantitative studies using corrosion casts

1999

The vascular architecture of four different tumour cell lines (CaX, CaNT, SaS, HEC-1B) transplanted subcutaneously in mice was examined by means of microvascular corrosion casting in order to determine whether there is a characteristic vascular pattern for different tumour types and whether it differs significantly from two normal tissues, muscle and gut. Three-dimensional reconstructed scanning electron microscope images were used for quantitative measurements. Vessel diameters, intervessel and interbranch distances showed large differences between tumour types, whereas the branching angles were similar. In all tumours, the variability of the vessel diameters was significantly higher than …

Community effects allow bioelectrical reprogramming of cell membrane potentials in multicellular aggregates: Model simulations.

2020

Bioelectrical patterns are established by spatiotemporal correlations of cell membrane potentials at the multicellular level, being crucial to development, regeneration, and tumorigenesis. We have conducted multicellular simulations on bioelectrical community effects and intercellular coupling in multicellular aggregates. The simulations aim at establishing under which conditions a local heterogeneity consisting of a small patch of cells can be stabilized against a large aggregate of surrounding identical cells which are in a different bioelectrical state. In this way, instructive bioelectrical information can be persistently encoded in spatiotemporal patterns of separated domains with diff…

Metabolic Status and Reaction to Heat of Normal and Tumor Tissue

1995

The occurrence of differential heating and differential thermal sensitivity between malignant tumors and normal tissues is thought to be due to limited heat dissipation and energy depletion in many solid tumors which in turn results from an inadequately functioning tumor microcirculation (Jain and Ward-Hartley 1984; Song 1984, 1991; Vaupel and Kallinowski 1987; Reinhold 1988; Vaupel et al. 1988a; Vaupel 1990). As a consequence of the latter pathophysiological condition, supply and drainage function are restricted in many solid tumors or, at least, in some tumor areas, thus creating a hostile metabolic microenvironment characterized by tissue hypoxia, acidosis, and energy depletion. Thermal …

Correlation between Regional Atp and Blood Flow in Tumors and Surrounding Normal Tissue

1994

Various experimental and human tumors are characterized by a marked heterogeneity in the pathophysiologic micromilieu (1, 2). An inadequate and heterogeneous nutritional blood supply has been suggested to explain the non-uniform distribution of oxygen, pH, and high energy phosphates as it has been observed by many investigators (3, 4). Although there is a distinct understanding of the general interrelationships between these parameters (5), little is known about their actual regional correlation, which cannot be assessed by global measurements. With the autoradiographic method for measurement of blood flow (6, 7) and the metabolic imaging with ATP-induced bioluminescence (8, 9) it has becom…

In Vitro Assessment of the Genotoxic Hazard of Novel Hydroxamic Acid- and Benzamide-Type Histone Deacetylase Inhibitors (HDACi)

2020

Histone deacetylase inhibitors (HDACi) are already approved for the therapy of leukemias. Since they are also emerging candidate compounds for the treatment of non-malignant diseases, HDACi with a wide therapeutic window and low hazard potential are desirable. Here, we investigated a panel of 12 novel hydroxamic acid- and benzamide-type HDACi employing non-malignant V79 hamster cells as toxicology guideline-conform in vitro model. HDACi causing a &ge

Effect of Localized Hyperthermia on Tumor Blood Flow and Oxygenation

1984

Hyperthermia has been shown to have a lethal effect in tumor cell cultures, particularly at temperatures above 42°C.1 Moreover, it has been demonstrated that hyperthermia retards the growth rate of certain types of malignant tumors and can be effective in completely eradicating some tumors without any major damage to normal tissue.2,3,4 The differential response of solid tumors in vivo to heat treatment in comparison to normal tissue probably results from several factors. Among these the in vivo micro-environment seems to play a decisive role. In general, the interstitial milieu of solid tumors is characterized by tissue hypoxia and anoxia5,6 and by severe tissue acidosis.7 These unfavorabl…

TISSUE OXYGENATION AND NORMAL AND HYPERTHERMIC CONDITIONS

1981

Publisher Summary This chapter describes the tissue oxygenation and normal and hyperthermic conditions. The knowledge of the effect of hyperthermia on tumor and normal tissue blood flow is important not only for the effect of hyperthermia on hypoxic cells at the time of radiation, but also for differential tumor heating. There is considerable evidence from plethsmography that an elevation of normal tissue temperature to 41°C is accompanied by a considerable increase in blood flow. The chapter discusses studies that were conducted to examine changes in the microenvironment of normal and tumor tissue as measured directly with ultramicroelectrodes. In situ studies were carried out in fourth ge…

Pathophysiological aspects of hyperthermia

1992

Blood flow in many rapidly growing tumors is sluggish leading to an impairment of convective heat dissipation which facilitates tumor heating compared to normal tissues. In addition, the compromised microcirculation causes a hostile metabolic micromilieu which can modulate the therapeutic effect of heat. After clinically relevant heat doses, a shut-down of tumor microcirculation is often observed creating a “heat-reservoir” and aggravating tumor hypoxia, acidosis, and substrate and energy depletion, factors which are known to greatly enhance tumor cell killing by heat. Since the mechanisms described are mostly derived from experimental results on fast-growing animal tumors, the clinical rel…