Here in <i>ex vivo</i> (confocal imaging) and <i>in vivo</i> (optical coherent tomography) experiments on adult mice, we clearly demonstrate that the meningeal lymphatic drainage is an important mechanism for the brain clearing that might be also pathway for the brain clearing from metabolites and waste products that requests further detailed studies. Photodynamic effects stimulate the meningeal/cervical drainage opening new ideas for development of novel methods of activation of brain clearing that might be progressive strategies in therapy of neurovegetative diseases.
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 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.
We discuss entrainment phenomena in the regulation of cerebral and peripheral blood flow in newborn rats under normal conditions and during pathological changes in the dynamics of blood vessels accompanying the development of stroke. Using a wavelet-based coherence measure, we analyze the degree of interrelation between the dynamics of blood flow in the sagittal sinus, the surrounding network of small vessels, as well as in the artery and vein of the neck. We show that the coherence measure reflects changes in the entrainment at the latent stage of stroke formation.
In the recent study delta-ALA/PpIX is used as fluorescent marker for tumor detection in stomach, small intestine and colon. 5-ALA was administered per os two hours before measurements at dose 20 mg/kg weight. Twenty laboratorial rats with developed neoplasia in gastrointestinal tract were used. Three of them formed control group - without application of exogenous 5-ALA/PpIX, as a contrast fluorescent marker. Their spectral properties were evaluated and used for correction of endogenous sources of fluorescence from stomach and intestine lesions detected. Macroscopic fluorescence spectroscopy parameters of gastrointestinal tissues of the other 17 animals, which were sensitized with 5- ALA?PpIX, were obtained on excitation at 405 nm. Excitation and emission light was delivered by fiberoptic probe 6+1 to the organs investigated in vivo during open surgery procedure on the laboratorial animals used. The fluorescence detected from tumor sites has very complex spectral origins. It consists of autofluorescence, fluorescence from exogenous fluorophores and re-absorption from the chromophores accumulated in the tissue investigated. Spectral features observed during endoscopic investigations could be distinct as the next regions: 450-630 nm region, where tissue autofluorescence is observed; 630-710 nm region, where fluorescence of PpIX is clearly pronounced; 530-580 nm region, where minima in the autofluorescence signal are observed, related to re-absorption of oxy-hemoglobin in this spectral area. The contrast achieved in normal vs. neoplastic gastrointestinal tissues was evaluated. Influence of endogenous 5-ALA/PpIX accumulation was taken into account; as well the role of inflammatory processes on the PpIX distribution and accumulation into the body was evaluated. Dimensionless ratio R=I<sub>635</sub>/I<sub>560</sub> is evaluated as highly informative one for development of a simple algorithm for differentiation, which could has high diagnostic accuracy for evaluation of tumor vs. inflammatory vs. normal mucosa, using 1-D spectral results. Very good correlation between fluorescence data and histology examination of the lesions investigated was achieved as well.