NADH is one of the central signalling molecules that serve as a substrate for many vital processes, in particular, is a donor for the electron transport chain in mitochondria. At the same time, mitochondrial activity and the intensity of metabolic processes in the tissues of different brain regions drastically differ. This work aimed to compare the NAD(P)H production rate in the tissues of various brain regions (cortex, cerebellum, hippocampus, brainstem) assessed by the parameters of dynamics of its autofluorescence. We studied acute slices of the rat brain of the corresponding regions. The intensity of NAD(P)H autofluorescence and its rate of production was determined to assess the activity of mitochondria. Whereafter the slices were analysed by histological examination. It has been observed that mitochondrial activity in hippocampal tissues is significantly higher than in other brain regions, which may be associated with more complex cognitive functions of the hippocampus in mammals. The results of this research can help explain the selectivity of hippocampal lesions during ischemic injuries and neurodegenerative diseases.
The paper describes the results of experimental studies using custom developed optical biopsy system for diagnostics in vivo during the procedure of fine needle aspiration biopsy. Experimental studies were conducted in laboratory mice with inoculated hepatocellular carcinoma. The measurements were carried out using fluorescence spectroscopy and diffuse reflectance spectroscopy methods to reveal metabolic and morphological changes in tissues. The results show that the developed approach is sensitive for cancer detection. Quantified differences in the maximum of fluorescence spectra and diffuse reflectance spectra between tumor and normal tissues were demonstrated and approved with morphological analysis.
The aim of the study was to compare the metabolic activity of brain cortex after the acute hypoxia caused by the impairment of breathing or blood circulation. Male Wistar rats were randomized in two groups: impaired breathing and blood circulation failure groups. Fluorescence under 365 and 450 nm excitation and diffuse reflectance intensity at 550-820 nm range were estimated. We found that after long-term hypoxic conditions, notable metabolic changes occur. We suppose that oxygen deficiency causes an activation of the GABA shunt mechanism. In cases of blood circulation failure, fluorescence intensity changes faster than in cases of breathing impairment.
The paper describes the methodology and technical implementation of a multimodal approach for optical diagnostics in hepatopancreatobiliary organs focal and diffuse neoplasms. Fine needle aspiration biopsy technique and following cytological examination show its effectiveness and safety but its performing takes several days. However, the problem of real-time analysis of pathological changes in tissues remains relevant. The solution suggested is implementing of optical biopsy methods (namely fluorescence spectroscopy and diffuse reflectance spectroscopy) in the form of fiber-optic probe compatible with standard biopsy fine needles. The special device was designed for this purpose to conduct optical measurements and compare the results with ones obtained by conventional biopsy. The proposed methodology seems promising for developing new diagnostic criteria for clinical practice.
Fine needle aspiration biopsy technique and following histological examination show its effectiveness and safety but its performing takes several time. However, the problem of real-time analysis of pathological changes in tissues remains relevant. We demonstrate optical fine-needle biopsy method, combining a fine needle (17.5G) and a fiber-optic probe (1 mm diameter) for minimally invasive interrogation of tissue in vivo. During rat tumor experiment, we collected spectrally-resolved diffuse reflectance and fluorescence. Quantified differences between tumor and normal tissues were demonstrated and approved with morphological analysis. The proposed methodology seems promising for developing new diagnostic criteria for clinical practice.
This studiy was carried out on groups of clinically healthy male Wistar rats. Animals received distilled drinking water ad libitum for 1 month, water containing succinic acid, water containing zinc sulphate and succinate zinc. Using the method of fluorescence spectroscopy, the parameters of brain metabolism in vivo in a model of laboratory rats was investigated. Based on data obtained by fluorescence spectroscopy, we have registered a change in the degree of cellular respiration in different structures of the cerebral cortex with the toxic effect of zinc compounds and succinic acid on the oxygen exchange process.
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