The adult human brain represents only 2 % of the body's total weight, however it is one of the most metabolically active organs in the mammalian body. Its high metabolic activity necessitates an efficacious waste clearance system. Besides the blood, there are two fluids closely linked to the brain and spinal cord drainage system: interstitial fluid (ISF) and cerebrospinal fluid (CSF). The aim of this review is to summarize the latest research clarifying the channels of metabolite removal by fluids from brain tissue, subarachnoid space (SAS) and brain dura (BD). Special attention is focused on lymphatic vascular structures in the brain dura, their localizations within the meninges, morphological properties and topographic anatomy. The review ends with an account of the consequences of brain lymphatic drainage failure. Knowledge of the physiological state of the clearance system is crucial in order to understand the changes related to impaired brain drainage.
Agriculture faces several challenges to use the available resources in a more environmentally sustainable manner. One of the most significant is to develop sustainable water management. The modern Internet of Things (IoT) techniques with real-time data collection and visualisation can play an important role in monitoring the readily available moisture in the soil. An automated Arduino-based low-cost capacitive soil moisture sensor has been calibrated and developed for data acquisition. A sensor- and soil-specific calibration was performed for the soil moisture sensors (SKU:SEN0193 - DFROBOT, Shanghai, China). A Repeatability and Reproducibility study was conducted by range of mean methods on clay loam, sandy loam and silt loam soil textures. The calibration process was based on the data provided by the capacitive sensors and the continuously and parallelly measured soil moisture content by the thermo-gravimetric method. It can be stated that the response of the sensors to changes in soil moisture differs from each other, which was also greatly influenced by different soil textures. Therefore, the calibration according to soil texture was required to ensure adequate measurement accuracy. After the calibration, it was found that a polynomial calibration function (R2 ≥ 0.89) was the most appropriate way for modelling the behaviour of the sensors at different soil textures.
Chlorophyll fluorescence has developed into a well-established noninvasive technique to study photosynthesis and by extension, the physiology of plants and algae. The versatility of the fluorescence analysis has been improved significantly due to advancements in the technology of light sources, detectors, and data handling. This allowed the development of an instrumention that is effective, easy to handle, and affordable. Several of these techniques rely on point measurements. However, the response of plants to environmental stresses is heterogeneous, both spatially and temporally. Beside the nonimaging systems, low- and high-resolution imaging systems have been developed and are in use as real-time, multi-channel fluorometers to investigate heterogeneous patterns of photosynthetic performance of leaves and algae. This review will revise in several paragraphs the current status of chlorophyll fluorescence imaging, in exploring photosynthetic features to evaluate the physiological response of plant organisms in different domains. In the conclusion paragraph, an attempt will be made to answer the question posed in the title., R. Valcke., and Obsahuje bibliografické odkazy
Attention-deficit/hyperactivity disorder (ADHD) is a mental disorder with a heterogeneous origin with a global incidence that continues to grow. Its causes and pathophysiological mechanisms are not fully understood. It includes a combination of persistent symptoms such as difficulty in concentration, hyperactivity and impulsive behavior. Maternal methamphetamine (MA) abuse is a serious problem worldwide, it can lead to behavioral changes in their offspring that have similarities with behavioral changes seen in children with ADHD. There are several types of ADHD animal models, e.g. genetic models, pharmacologically, chemically and exogenously induced models. One of the exogenously induced ADHD models is the hypoxia-induced model. Our studies, as well as those of others, have demonstrated that maternal MA exposure can lead to abnormalities in the placenta and umbilical cord that result in prenatal hypoxia as well as fetal malnutrition that can result in irreversible changes to experimental animals. Therefore, the aim the present study was to compare the cognitive impairments in MA exposure model with those in established model of ADHD – prenatal hypoxia model, to test whether MA exposure is a valid model of ADHD. Pregnant Wistar rats were divided into four groups based on their gestational exposure to MA: (1) daily subcutaneous injections of MA (5 mg/kg), (2) saline injections at the same time and volume, (3) daily 1-hr hypoxia (10 % O2), and (4) no gestational exposure (controls). Male rat offspring were tested for short-term memory in the Novel Object Recognition Test and the Object Location Test between postnatal days 35 and 40. Also their locomotor activity in both tests was measured. Based on the present results, it seems that prenatal MA exposure is not the best animal model for ADHD since it shows corresponding symptoms only in certain measures. Given our previous results supporting our hypothesis, more experiments are needed to further test possible use of prenatal MA exposure as an animal model of the ADHD.
Capsazepine is a competitive antagonist of capsaicin, a TRPV1 agonist responsible for the spicy taste of pepper. TRPV1 agonists and antagonists are known to affect mammalian body temperature, but their action on thermoregulation in insects is poorly known. In this study we evaluated the effect of capsazepine on the thermal preference of the American cockroach, Periplaneta americana using a thermal gradient. Our results revealed that capsazepine in submicromolar concentrations induces a preference for higher ambient temperatures when compared to the control insects. To assess whether capsazepine may act also as an antagonist of capsaicin in insects, we determined this insects' thermal behaviour when capsazepine was applied before capsaicin. The hypothermic response to capsaicin was clearly blocked by pre-treatment with capsazepine only in female American cockroaches. Our results indicate the involvement of structures functionally similar to TRPV1 in insect thermosensation., Justyna Maliszewska, Eugenia Tęgowska., and Obsahuje bibliografii
Phototherapy is the most effective non-invasive method of neonatal hyperbilirubinemia treatment. Application of this method can be associated with side effects including changes in the cardiovascular system. During phototherapy, the primary effects in the cardiovascular system include cutaneous vasodilation leading to skin hyperperfusion and subsequent redistribution of blood. The increased blood flow through the skin is associated with increased transepidermal water loss. Further effects include an increase in cerebral blood flow. Redistribution of blood to the cutaneous bed is compensated by hypoperfusion in the splanchnic area (mostly postprandial) and a significant reduction of the renal blood flow. Regarding closure/reopening of the ductus arteriosus, the results suggest that that phototherapy does not affect ductal patency. During phototherapy the cardiac output can be slightly reduced due to a decreased stroke volume, especially in preterm newborns. Systemic blood pressure is decreased and heart rate is elevated in both preterm and term newborns during phototherapy. The heart rate variability is slightly reduced. Symbolic dynamics analysis of the short-term HRV showed that during phototherapy the activity of the ANS regulating the heart rate is shifted towards the dominancy of the sympathetic activity. The responses in the cardiovascular system of premature/mature newborns without other pathology confirm a well physiologically functioning control of this system, even under specific conditions of phototherapy.
Down Syndrome (Ds) is the most common chromosomal cause of intellectual disability that results from triplication of chromosome 21 genes. Individuals with Ds demonstrate cognitive deficits in addition to comorbidities including cardiac defects, pulmonary arterial hypertension (PAH), low blood pressure (BP), and differences in autonomic regulation. Many individuals with Ds are born with heart malformations and some can be surgically corrected. Lower BP at rest and in response to exercise and other stressors are a prevalent feature in Ds. These reduced cardiovascular responses may be due to underlying autonomic dysfunction and have been implicated in lower exercise/work capacity in Ds, which is an important correlate of morbidity, mortality and quality of life. Exercise therapy can be beneficial to normalize autonomic function and may help prevent the development of co-morbidities in Ds. We will review cardiovascular physiology and pathophysiology in individuals with Ds, along with exercise therapy and special considerations for these individuals.
Osteoporosis is a bone disease characterized by low bone mineral density (BMD) and impaired bone microarchitecture due to the abnormal activity of osteoclasts. Cathelicidins are antimicrobial peptides present in the lysosomes of macrophages and polymorphonuclear leukocytes. LL-37, a cathelicidin, induces various biological effects, including modulation of the immune system, angiogenesis, wound healing, cancer growth, as well as inflammation, and bone loss. A previous study reported direct involvement of LL-37 suppressing osteoclastogenesis in humans. Here, we examined the role of LL-37 in the treatment of osteoporosis using an ovariectomy (OVX) rat model. Our results showed that LL-37 significantly reduced bone loss and pathological injury in OVX rats with osteoporosis. Furthermore, we found that LL-37 significantly increased the activity of the Wnt/β-catenin pathway in OVX rats with osteoporosis, including the increased expression of β-catenin, Osterix (Osx), and Runt-related transcription factor 2 (Runx2), whereas XAV-939, an inhibitor of the Wnt/β-catenin pathway, significantly blocked the effects of LL-37 on bone loss and abnormal bone metabolism. Altogether, our findings suggested that LL-37 exerted a protective role in regulating bone loss and abnormal bone metabolism in rats with osteoporosis by activating the Wnt/β-catenin pathway.
Metabolic flux investigations of cells and tissue samples are a rapidly advancing tool in diverse research areas. Reliable methods of data normalization are crucial for an adequate interpretation of results and to avoid a misinterpretation of experiments and incorrect conclusions. The most common methods for metabolic flux data normalization are to cell number, DNA and protein. Data normalization may be affected by a variety of factors, such as density, healthy state, adherence efficiency, or proportional seeding of cells. The mussel-derived adhesive Cell-Tak is often used to immobilize poorly adherent cells. Here we demonstrate that this coating strongly affects the fluorescent detection of DNA leading to an incorrect and highly variable normalization of metabolic flux data. Protein assays are much less affected and cell counting can virtually completely remove the effect of the coating. Cell-Tak coating also affects cell shape in a cell line-specific manner and may change cellular metabolism. Based on these observations we recommend cell counting as a gold standard normalization method for Seahorse metabolic flux measurements with protein content as a reasonable alternative.