Gastrointestinal tract neoplasia is on the third place of death statistics among oncological diseases, which is associated with the difficulty of early diagnosis of this disease. This study aims to evaluate applicability of delta-aminolevulinic acid / protoporphyrin IX photosensitizer (5-ALA / PpIX) as diagnosing agent for detection of small and large intestine neoplasia. The experiments were performed <i>in vivo</i> on white laboratorial rats. The animals were divided into 2 groups: control and experimental (overpopulation social stress and a diet, including nitrites and amines) ones. The results of the studies, averaged for each type of tissue, clearly show significant differences between normal tissues and malignant intestine tissues of the rats useful for fluorescent-based discrimination of the tissue state. The fluorescence from malignant areas in small and large intestine represented bright red fluorescence with specific maxima at 635 and 704 nm, typical for PpIX, due to the high accumulation of this photosensitizer in the affected tissues. The accumulation of protoporphyrin IX in the intestine cancerous tissues was very well pronounced. A contrast achieved between normal and abnormal tissue sites at 635 nm fluorescence emission was more than an order of magnitude in the case of large intestine neoplasia, which allows using the 5-ALA/PpIX as a sensitive indicator of gastrointestinal carcinoma.
Gastric cancer is the main cause of death among oncological diseases of the gastrointestinal tract, which is associated with the difficulty of early diagnosis of this disease. This study aims to develop a new method for diagnosing gastric cancer using the delta-aminolevulinic acid / protoporphyrin IX photosensitizer (5-ALA / PpIX). The experiments were performed on white rats of average weight 250 grams. The animals were divided into 2 groups: control and experimental (stress + diet, including nitrites and carcinogenic amines) ones. The results of the studies, averaged for each type of tissue, clearly show significant differences between normal, precancerous and malignant changes in the stomach tissues of rats on the background of application of photodynamic diagnostics. The fluorescence from malignant neoplasms in the organ was maximal at 635 nm, which corresponds to the maximum emission of protoporphyrin due to the high accumulation of this photosensitizer in the affected tissues. The most important result of the study was the detection of precancerous changes (atrophic gastritis, confirmed by histological methods), using photodynamic diagnostics with photosensitizer 5-ALA / PpIX. Intensity of fluorescence in case of precancerous changes occupied an intermediate value between that in normal and in malignant mucosa of the stomach.
Gastric cancer often appears without preliminary symptoms that could be detected and recognized at early stages. Its diagnostic is sometime provided based on photodynamic techniques, although the latter are restricted by quite poor tumor selectivity. Due to this, additional experimental and data processing tools are required to improve diagnostic abilities. In this study we analyze how complexity measures can detect early changes in the normal gastric microcirculation. We apply a recently developed approach based on the multiscale entropy and show that the estimated measures of SampEn related to distinct ranges of scales enable the detection of early gastric cancer that is in accordance with the results of histological analysis.
Stroke and traumatic brain injury are often associated with formation of brain edema, which is a potentially fatal pathological state provoking extensive accumulation of fluid in the brain tissues resulting in elevation of intracranial pressure and leading to impaired nerve function. There is only symptomatic anti-edema therapy is currently available. Therefore, the development of novel strategies to remove edema fluid is required. The brain edema is classified as vasogenic or cytotoxic edema, which associated with excess accumulation of fluid (edema) around capillaries resulting from disruption of the blood-brain barrier (BBB) or intracellular spaces (cell swelling) of the brain, respectively. In this brief review, we discuss possible mechanisms underlying brain edema formation and new strategies in development of novel of anti-edema drugs.
Here we present preliminary experimental data suggesting about involvement of the meningeal and cervical lymphatics in neurorehabilitation. Using model of hemorrhagic stroke, immunohistochemical analysis and atomic absorption spectroscopy, we clearly demonstrate the lymphatic clearance from the blood after stroke via the meningeal lymphatic vessels with further accumulation of hemosiderin and iron (products of disaggregated hemoglobin) in the deep cervical node (dcLN). The optical coherent tomography (OCT) was used for in vivo monitoring of accumulation of gold nanorods (92 nm in diameter) in the dcLN after their injection into the cisterna magna with the aim of mimicking of the brain clearance from of blood. The both ex vivo and in vivo data show the lymphatic clearance from subjects (the blood/GNRs) injected into the subarachnoid space that might be an important mechanism of neurorehabilitation after the intracranial hemorrhages.