Free radicals in beer production impact flavor, color, and shelf life. Managing them is crucial for ensuring consistent brewing quality.
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It is possible to obtain 3D map of redox status in a fast and non-invasive way? Antioxidant defence system and stabilized level of reactive oxygen species (ROS) protect organisms against various diseases such as stroke or inflammation. In order to create an effective therapy for such diseases, the in vivo redox status map may be useful. The fact is that EPR imaging, with a suitable external imaging probe, is a great tool for monitoring the balance or imbalance between oxidation and reduction reactions and assessing the redox state of the brain. That issue was considered by Hirotada Fujii and his research group in the paper “Mapping of Redox Status in a Brain-Disease Mouse Model by Three-Dimensional EPR Imaging”. Control mice and transient middle cerebral artery occlusion (MCAO) mice were used as the subjects in this experiment. The in vivo redox state in the brains of control and MCAO mice was measured by improved EPR imager that enabled rapid data acquisition, engineered by Fuji and colleagues. Reduction of the acquisition time has allowed to obtain high-quality 3D images in a very short time. A nitroxide, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxy (HMP), was used as a redox-sensitive spin probe. HMP has passed freely through the brain-blood barrier, which was also confirmed by MRI examination. The redox status of MCAO mice was visualized as 3D maps, where each voxel represents half-live of HMP in the difference part of brain. The half-life mapping of HMP has shown a significant heterogeneity of the redox state in brain of MCAO mice. It was also revealed that there is an increase of HMP in the brain of ischemia-reperfusion-treated mice, and consequently, the reduction rate of nitroxide is slower in MCAO mice. This study confirmed that with the use of an EPR scanner and given an appropriate time of data acquisition, is it possible to provide a 3D map of the in vivo redox state in the mouse brain . Therefore, the role of EPR imaging systems in the research on redox status is significant. References: Fujii H, Sato-Akaba H, Kawanishi K, Hirata H.; Mapping of redox status in a brain-disease mouse model by three-dimensional EPR imaging; Magn Reson Med. 2011 Jan;65(1):295-303; DOI: 10.1002/mrm.22598.
It is possible to obtain 3D map of redox status in a fast and non-invasive way? Dowiedz się więcej »
It is possible to conduct in-vivo pO2 measurements in conscious mouse? It is a well-known fact that the oxygenation level is a significant determinant when it comes to identifying and monitoring neoplastic changes. Another fact is that anesthetics affect the physiology of the oxygen inside the animal’s body, which could cause inaccuracies during in vivo experiments. The question is whether it is possible to monitor conscious animal, avoiding the anesthesia’s impact and, simultaneously, collect high-quality data. To answer this question, we begin by taking a closer look at the study conducted by Matsumoto et al. “Dynamic Monitoring of Localized Tumor Oxygenation Changes Using RF Pulsed Electron Paramagnetic Resonance in Conscious Mice”. The authors used an electron paramagnetic resonance (EPR) spectroscopy at frequency of 750 MHz to assess the pO2 level in tumor bearing mice. Crystals of lithium phthalocyanine (LiPc) was implanted into squamous cell carcinoma (SCC) tumor and femoral muscle on opposing legs of mice. It has been examined whether there is a correlation between oxygenation and factors such as anesthesia, body temperature and carbogen inhalation. As a consequence of the conducted experiment, this correlation has been confirmed by Matsumoto and colleagues. In conclusion, EPR spectroscopy, due to a rapid acquisition of spectral data, enables the pO2 measurements in conscious mice and minimizing the influence of anesthetics. This ability makes the EPR with LiPc a powerful tool in oncology researches, especially. in studies on tissues oxygenation. References: Matsumoto S. et al.; Dynamic monitoring of localized tumor oxygenation changes using RF pulsed electron paramagnetic resonance in conscious mice; Magn Reson Med. 2008 Mar;59(3):619-25; DOI: 10.1002/mrm.21500.
It is possible to conduct in-vivo pO2 measurements in mouse? Dowiedz się więcej »
Biological differences between cancerous tissues and healthy ones. Nowadays, a fight against cancer seems to be one of the most important issue for scientists. Research groups all around the world are working on new cancer therapies which target tumour cells. One of the approaches to this problem consists in learning the physiological differences between normal and neoplastic tissue. The differences could appeared among physiological parameters such as redox state, oxygenation and pH value. The fact is that Electron Paramagnetic Resonance is a non-invasive and rapid method that enables detection of insignificant changes of above-mentioned characteristics and thus it is a great tool for preclinical cancer research and has a great potential to become a method used in clinical trials. A hypothesis that the redox state and pO2 value differ in normal and neoplastic tissue, have been presented in a paper “Noninvasive Imaging of Tumor Redox Status and Its Modification by Tissue Glutathione Levels” by Kuppusamy et al. The main goal of the research was: i) develop a non-invasive technique that enables measurement and imaging of the tissue’s redox state ii) acquire images of redox state from normal and malignant tissue iii) analyse the role of glutathione (GSH) in changes of the redox status. In examinations conducted by the research group, in vivo EPR spectroscopy and imaging (EPRI) with a nitroxide spin probe were used. Buthionine sulfoximine (BSO), as a GSH synthesis inhibitor, was applied to decrease the level of GSH in a tissue. The subject was tumour-bearing mice with implanted radiation-induced fibrosarcoma (RIF-1) tumour growing in the right leg. The normal tissue from the left leg was used as a control. The results of experiments have confirmed the hypothesis posed by the research group. It has been shown that physiological parameters such as redox status, in the normal tissue and in the neoplastic tissue significantly differ from each other. Obtained data showed that it was a higher concentration of GSH in malignant tissue. It was also noted that BSO treatment causes differences in reduction of GSH level. Tumour tissue showed higher reduction rate in comparison to healthy tissue. Physiological differences between malignant tissue and normal tissue are a significant factor involved in improving cancer treatments, and what is important, EPR technique is a very promising and helpful tool in such researches. References: Kuppusamy P. et al.; Noninvasive imaging of tumor redox status and its modification by tissue glutathione levels; Cancer Res. 2002 Jan 1;62(1):307-12.
Biological differences between cancerous tissues and healthy ones. Dowiedz się więcej »
EPR is making its way to clinical studies There are subtle physiological differences between normal tissue and tumour tissue. These differences mainly concern characteristics such as redox status and pO2 levels. Thus, imaging methods that enable detection of these biological variations may be valuable in developing treatment strategies. Electron Paramagnetic Resonance Imaging is capable of non-invasive measurements of redox state and pO2 level, involving proper nitroxide probes. The study of the distribution and lifetime of nitroxides in normal and tumour tissue was the aim of Kuppusamy’s research paper “In vivo Electron Paramagnetic Resonance Imaging of Tumour Heterogeneity and Oxygenation in a Murine Model”. As has been pointed out, nitroxides occur in biological systems in two forms: as a free radical and/or as a diamagnetic hydroxylamine which is a product of one-electron reduction of the nitroxide free radical. The reduction rate of nitroxides is increasing during hypoxia conditions. A specificity of these compounds may indicate some of the physiological differences in tissues, which exist under various oxygenation levels. In order to detect tissue heterogeneity, three nitroxides were used: TPL (4-OH, 2,2,6,6-tetramethylpiperidine-1-oxyl ), 3-CP (3-carbamoyl-proxyl) and PDT (4-oxo-L,2,6,6-tetramethylpiperadine-1-oxyl). TPL has been specified as an in vitro radioprotector, the 3-CP, due to greater biostability in tissues, was used in in vivo EPRI experiments and PDT was used as a probe for pO2 levels assessment. Mice bearing tumour in size approximately 10 – 15 mm in diameter were examined. Electron Paramagnetic Resonance Imaging was used to perform measurements of reduction rates, distribution and levels of nitroxides in normal and tumour tissues. The obtained results have shown that the peak level of nitroxides was significantly lower in the tumour tissue. Moreover, the reduction rate of nitroxides was much higher in tumours, compared to normal tissues. 3D imaging has confirmed a significant heterogeneity in the distribution of spin probes and redox state in tumour tissue, whereas normal tissues has remained homogenous. With the use of PDT, a significant difference in pO2 level between normal tissue and tumour tissue have been shown. An average level of oxygenation in tumours was three times lower, then in normal tissue. A state of hypoxia in tumours is linked to lower nitroxides content and its greater reduction rate. The study conducted by Kuppusamy’s group has confirmed, that EPRI is a technique that enables performing both the spatial bio-distribution and functional imaging as a result of spectral properties of nitroxides. EPRI may be a breakthrough approach to plan treatment of neoplastic diseases. References: Kuppusamy P et al.;In vivo electron paramagnetic resonance imaging of tumor heterogeneity and oxygenation in a murine model; Cancer Res. 1998 Apr 1;58(7):1562-8.
Differences Between Normal Tissue and Tumour Tissue Dowiedz się więcej »
A new therapeutic approach for neurodegenerative diseases. Nowadays, neurodegenerative diseases are a very serious problem. Scientists are trying to discover all the mechanisms for the formation of diseases such as Alzheimer’s, as well as finding a way to diagnose them faster and treat them more effectively. An interesting fact is that a research group led by professor Emoto has conducted a series of animal studies, the result of which was the discovery of a potential therapeutic approach for neurodegenerative diseases. The details of those experiments were shown in the article “Non-invasive imaging of the levels and effects of glutathione on the redox status of mouse brain using electron paramagnetic resonance imaging”. The authors’ purpose was to determine the influence of gluthathione (GSH) on the redox state in the mouse brain. In order to measure the GSH level in animal models, electron paramagnetic resonance (EPR) imaging and a redox-sensitive nitroxide imaging probe, 3-methoxycarbonyl-2,2,5,5-tetramrthylpiperidine-1-oxyl (MCP), were used. As emphasized, the antioxidants defence system, endogenous antioxidants compounds and enzymatic systems are able to protect the brain from oxidative damage. On the one hand, GSH and ascorbic acid (AsA) are the main endogenous antioxidants. More importantly, their level of concentration could change in the case of a disease. It should be mentioned that AsA, in contrast to GSH, directly influences the reduction of nitroxides. On the other hand, nitroxide probes, once introduced into the animal’s body, are easily reduced under the oxidative stress condition. The reduction rate of nitroxides may be considered as a ratio of in vivo redox state. Therefore, the capabilities of EPR imaging and the MCP probe have been used in this examination. On the basis of the map of MCP reduction rate, a visualization of the redox state in an animal model under oxidative stress has been made. Due to the reduction of GSH levels in the animal’s body, the redox map of mice brain (control and GSK-depleted) has shown a significant change in the redox state. The linear relationship between the reduction rate of nitroxide probe and the GSH concentration in both control and GSH-depleted mice, has been observed. Therefore, this correlation could be used as a potential method for estimating the GSK levels in vivo from the redox map. Of course, this type of measurement could be conducted with the use of EPR and a nitroxide probe. It is important to emphasize that GSH levels decrease in the case of diseases related to oxidative stress, such as Alzheimer’s disease. The increase of GSK levels has a potential approach for creating therapies against neurodegenerative disorders. The contribution of GSK to neurodegenerative diseases needs detailed studies, and fortunately EPR imaging could be helpful in such research. References Emoto MC, Matsuoka Y, Yamada KI, Sato-Akaba H, Fujii HG; Non-invasive imaging of the levels and effects of glutathione on the redox status of mouse brain using electron paramagnetic resonance imaging; Biochem Biophys Res Commun. 2017 Apr 15;485(4):802-806; DOI: 10.1016/j.bbrc.2017.02.134.
A new therapeutic approach for neurodegenerative diseases. Dowiedz się więcej »
5 servings of fruit and vegetables – why are they so important? “You should have at least 5 portions of fruit and vegetables every day” Sounds familiar? I bet you said yes. Doctors and nutritionists around the world constantly remind us of the importance of eating greens. See what we discovered and see why. Fruit and vegetables apart from all the beneficial vitamins and nutrients are important sources of antioxidants. Antioxidants slow down the ageing process and protect against the harmful effect of free radicals. It is best to eat raw fruit and vegetables and juice may be the perfect option on a busy day. We decided to conduct a simple experiment in which we compared peach and carrot juice. We wanted to see how they handle free radicals scavenging. We filled 0.5 ml Eppendorf with 150 ml of carrot juice and 150 ml of 1 mM nitroxide spin probe. The EPR signal from the sample was measured for 15 minutes using the Novilet L-band system. Then an analogous experiment was carried out with peach juice. After 15 minutes of the experiment, the signal from the carrot juice decreased exponentially by nearly 80%, while in the case of peach juice, the signal decay was linear and only decreased by about 20% So what did we conclude? The results showed that carrot juice was significantly more efficient at scavenging free radicals compared to peach juice. Quote to remember! The more juices you drink, the fewer free radicals you have! Cheers!
5 servings of fruit and vegetables – why are they so important? Dowiedz się więcej »
Why you shouldn’t forget about your coffee, but drink it as fast as you can? Coffee is one of the most popular hot beverages consumed every day all over the world. For some people drinking coffee is like a ritual, for some, it is a way of boosting the energy throughout the day and for others, it is a perfect choice during the first date. It is not surprising because who doesn’t like the scent of freshly brewed coffee in the morning? The debate on the impact of coffee on the human organism is going on for a while now. In an appropriate dose, coffee can be considered a beneficial source of antioxidants. We decided that, since we work so much with free radicals we could show you the information we learned after we looked more closely inside our cups. How many times did you make yourself a coffee at work or at home and then forget about it? We wanted to see if the antioxidant properties of coffee change after some time, and when it is the best time to drink it. We performed a simple experiment with our L-Band spectrometer. Easy access to the measured area, as well as straight-froward sample preparation, let us do the experiment during… well… a coffee break (who would expect that, right? ?). We compared the antioxidant capacity of the freshly brewed coffee with the coffee 1 hour after brewing. It appears that freshly brewed coffee has about 30% better antioxidant properties than the beverage that was tested later. We can’t wait to see other results. We think that comparing different types of coffee would be very interesting, to see how the brewing temperature can affect the antioxidant properties, how the antioxidant capacity impacts the taste. If you would be interested in carrying out those types of experiments let us know and we will discover the secrets of coffee together! Cheers! ☕☕☕
Why you shouldn’t forget about your coffee? Dowiedz się więcej »
EPR is making its way to clinical studies It was recently reported by Schaner PE et. all that the Electron Paramagnetic Resonance technique together with a specially designed spin probe called OxyChip can be successfully applied in clinical trials. This is the first reported example of this new approach. The method has the potential to complete the diagnostic and monitoring of the development of several types of cancers. 23 patients with severe cancer were enrolled in the study. OxyChips were implanted inside tumours and then the data was collected for a certain period of time. The signals were successfully obtained in 16 patients. The data directly showed the oxygen concentration in tumours, which allowed the authors to clarify if the cancer is hypoxic. The signals were collected by the surface resonator placed on the skin, where the OxoChip was implanted. In a conclusion, with the combination of EPR with OxoChip, it is possible to measure the level of oxygen in tumours directly from the patient’s body. The undoubted advantage of this method is repeatable and quick data collection. The uniqueness of the technique is the ability to repeat the measurements many times without the patient’s discomfort. References: Philip E. Schaner et.al.: First-In-Human Study in Cancer Patients Establishing the Feasibility of Oxygen Measurements in Tumors Using Electron Paramagnetic Resonance With the OxyChip, Front. Oncol. 2021 Oct 1;11:743256.
EPR is making its way to clinical studies Dowiedz się więcej »
