Integrative concept of homeostasis: translating physiology into medicine

To truly understand living systems they must be viewed as a whole. In order to achieve this and to come to some law to which living systems obey, data obtained on cells, tissues and organs should be integrated. Because there are no such laws yet, there is usually a long path for physiological findings obtained by reductionist approaches to be translated into medical practice. The concept and accompanying equations of homeostasis presented here are aimed to develop biological laws and to bridge this gap between physiology and medicine. The concept of homeostasis takes into account energy input and output, enlisting all relevant contributors. In homeostasis, input should equal the output. What I suggest here is that if the system is out of homeostasis, the homeostasis may be regained by changing any of the input or output components in an adequate manner, not only the one that has changed first. The proposed equation should enable for new lab findings regarding any pathophysiological conditions to find a more direct use in medicine. It should also ease ‘decision making’ in medicine and make therapy development and treatment outcome more straightforward and predictable. Finally, to recognize the basic laws of living systems enables for evolutionary adaptations and processes to be understood better

Mitochondria-Targeted Antioxidants: Future Perspectives in Kidney Ischemia Reperfusion Injury

Kidney ischemia/reperfusion injury emerges in various clinical settings as a great problem complicating the course and outcome. Ischemia/reperfusion injury is still an unsolved puzzle with a great diversity of investigational approaches, putting the focus on oxidative stress and mitochondria. Mitochondria are both sources and targets of ROS. They participate in initiation and progression of kidney ischemia/reperfusion injury linking oxidative stress, inflammation, and cell death. The dependence of kidney proximal tubule cells on oxidative mitochondrial metabolism makes them particularly prone to harmful effects of mitochondrial damage. The administration of antioxidants has been used as a way to prevent and treat kidney ischemia/reperfusion injury for a long time. Recently a new method based on mitochondria-targeted antioxidants has become the focus of interest. Here we review the current status of results achieved in numerous studies investigating these novel compounds in ischemia/reperfusion injury which specifically target mitochondria such as MitoQ, Szeto-Schiller (SS) peptides (Bendavia), SkQ1 and SkQR1, and superoxide dismutase mimics. Based on the favorable results obtained in the studies that have examined myocardial ischemia/reperfusion injury, ongoing clinical trials investigate the efficacy of some novel therapeutics in preventing myocardial infarct. This also implies future strategies in preventing kidney ischemia/reperfusion injury

Uteropexy in Sheep as Potential Method for Prevention of Uterine Torsion

Background: Uterine torsion is one of many causes of dystocia in sheep. Failure in performing of wright-time diagnostic procedures and treatment by certain obstetric procedures, can result with death of both fetus and ewe. There is sufficient knowledge about risk factors which could contribute to the occurrence of uterine torsion in sheep, but there is insufficient knowledge about measures for prevention of uterine torsion. The aim of this study was to evaluate the effects of performing incorporative uteropexy as potential method for prevention of uterine torsion. Cases: This research was part of the experimental research of changes in the anterior presentation in sheep fetuses due to their ventro-sacral position in the 2nd half of gestation. At the same sheep farm where afore mentioned research was conducted, the farmer has reported the death of 3 pregnant ewes. In all of 3 animals, torsion of the uterus was diagnosed by patho-anatomical examination. This study was conducted on 6 ewes. All of the animals were in the period around the 100th day of pregnancy at the time of clinical examination. The exact day of pregnancy was not determinated because of free mating in the herd. Confirmation of pregnancy in all of 6 ewes was performed by ultrasound examination. Uniparous pregnancy was found in all of 6 ewes. The entire surgical procedures were performed in the field conditions. Laparotomy was performed in the animals positioned in the left lateral recumbency. Surgical procedure of incorporative uteropexy was performed during the closure of muscle layers of abdominal wall. In need for experimental research of changes in the anterior presentation in sheep fetuses due to their ventro-sacral position in the second half of gestation, 14 days after surgical procedures were conducted, all of sheep were positioned by assistants into a sitting position so that their trunks were vertical to the ground and kept in that position for 2 min. Ultrasound examination of surgical place of uteropexy confirmed that, in all of animals, uteruses were in place of surgical procedures. All of 6 ewes included in this study lambed naturally. One of 6 sheep was sent for economic exploitation on the 14th day after lambing. At the slaughter line, the abdominal wall was evaluated at the site where the incorporative uteropexy was performed. Patho-anatomical examination revealed tissue adhesions at the junction of the uterine horn with the abdominal wall. Discussion: Postsurgical tissue adhesions develop during normal healing process of tissue. According to our knowledge, previous studies do not mention effective measures that could contribute to the prevention of uterine torsion in sheep, but attention is focused on prompt diagnosis and treatment of the disease. According to the results of this study, postsurgical tissue adhesions were developed and confirmed by patho-anatomical examination in 1 sheep.  Other 5 sheep were not economically exploited or sacrificed, and no studies were performed to establish the presence of postsurgical tissue adhesions. In conclusion, it could be said that incorporative uteropexy could be considered as preventive procedure in order to avoid the development of uterine torsion in ewes which have shown a history of this pathology, but also in ewes with identified risk factors for the disease. In future studies, it is necessary to identify more parameters which will contribute to identification of sheep which have high risk factors to obtain the torsion of uterus. Also, it is necessary to use non-invasive methods of clinical diagnostics, primary ultrasound diagnostic, to evaluate the area of ​​incorporative uteropexy in order to assess newly formed tissue adhesions as well as to assess the vitality of fetus. It is necessary to follow the lambing process of ewes with incorporated uterus, and to provide medical assistance to the animals if complications occur during the lambing time. Keywords: sheep, uterus, fetus, torsion, incorporative uteropexy

Urinary F2-Isoprostanes and Metabolic Markers of Fat Oxidation

Metabolomic studies of increased fat oxidation showed increase in circulating acylcarnitines C2, C8, C10, and C12 and decrease in C3, C4, and C5. We hypothesize that urinary F2-isoprostanes reflect intensity of fatty acid oxidation and are associated with circulating C2, C8, C10, and C12 directly and with C3, C4, and C5 inversely. Four urinary F2-isoprostane isomers and serum acylcarnitines are quantified using LC-MS/MS within the Insulin Resistance Atherosclerosis Study nondiabetic cohort (n = 682). Cross-sectional associations between fasting urinary F2-isoprostanes (summarized as a composite index) and the selected acylcarnitines are examined using generalized linear models. F2-isoprostane index is associated with C2 and C12 directly and with C5 inversely: the adjusted beta coefficients are 0.109, 0.072, and −0.094, respectively (P \u3c 0.05). For these acylcarnitines and for F2- isoprostanes, the adjusted odds ratios (ORs) of incident diabetes are calculated from logistic regression models: the ORs (95% CI) are 0.77 (0.60–0.97), 0.79 (0.62–1.01), 1.18 (0.92–1.53), and 0.51 (0.35–0.76) for C2, C12, C5, and F2-isoprostanes, respectively.The direction of the associations between urinary F2-isoprostanes and three acylcarnitines (C2, C5, and C12) supports our hypothesis. The inverse associations of C2 and C12 and with incident diabetes are consistent with the suggested protective role of efficient fat oxidation

IRON MODULATES NOREPINEPHRINE EFFECT ON ASTROCYTES

Aims: Astrocyte position between synapses and blood vessels allows them to ful l crucial functions such as regulation of synaptic activity and potassium bu ering. Well positioned in the close vicinity of synaptic cleft astrocytes are considered to be a direct target of norepinephrine (NE). Synaptic activity and neurotransmitter actions can be in uenced by extracellular iron. Here we investigated whether iron interacts with NE and if this interaction can modulate astrocyte response to NE. Methods: To investigate the interaction between iron and norepinephrine we used spectrophotometry approach. Iron e ect on astrocyte response to NE was examined by the whole-cell patch-clamp technique. Membrane currents were recorded from cultured cortical astrocytes prepared from WT rats. Results: Using spectrophotometry we observed that iron interacts with NE which leads to the formation of a stable complex in the 1:1 stoichiometry. We also found that iron bound to NE completely blocks NE-induced increase of large-conductance calcium sensitive potassium current in astrocytes. Conclusions: Astrocyte response to NE is modi ed when this neurotransmitter forms a complex with iron. This implies that NE binding to astrocytic noradrenergic receptors may be prevented by iron. Our ndings point toward compromised astrocyte functions related to the potassium bu ering when NE action is modified by iron.kategorija M3

Probing the Surface Polarization of Ferroelectric Thin Films by X-ray Standing Waves

Understanding the mechanisms underlying a stable polarization at the surface of ferroelectric thin films is of particular importance both from a fundamental point of view and to achieve control of the surface polarization itself. In this study, it is demonstrated that the X-ray standing wave technique allows the polarization near the surface of a ferroelectric thin film to be probed directly. The X-ray standing wave technique is employed to determine, with picometer accuracy, Ti and Ba atomic positions near the surface of three differently strained $\mathrm{BaTiO_3}$ thin films grown on scandate substrates, with a $\mathrm{SrRuO_3}$ film as bottom electrode. This technique gives direct access to atomic positions, and thus to the local ferroelectric polarization, within the first 3 unit cells below the surface. By employing X-ray photoelectron spectroscopy, a detailed overview of the oxygen-containing species adsorbed on the surface, upon exposure to ambient conditions, is obtained. The combination of structural and spectroscopic information allows us to conclude on the most plausible mechanisms that stabilize the surface polarization in the three samples under study. The different amplitude and orientation of the local ferroelectric polarizations are associated with surface charges attributed to the type, amount and spatial distribution of the oxygen-containing adsorbates

Energetski status krava sa različitim nivoom reproduktivne efikasnosti

Financial efficiency of dairy farms depends on the reproductive efficiency of cows on these farms. Reproductive efficiency of cows on farms depends on the occurrence of postpartum ovarian activity and the visible oestrus. Cows are in negative energy balance in early lactation. We hypothesized that negative energy balance adversely affects the onset of postpartum ovarian activity and occurrence of visible estrus. The pupils were 2 groups of cows: on the basis of ovarian activity (cows that showed ovarian activity until 30 days after parturition, and cows that ovarian activity showed later) and on the basis of visible postpartum estrus (cows that have shown a clinically visible oestrus to 70 days after parturition, and cows that were first estrus shown later). Performed to investigate the parameters of the metabolic profile in the first, fourth and eighth week after parturition. Cows with higher quality reproductive efficiency have lower concentrations of nonesterified fatty acids and ketones, and higher glucose concentration. These results confirm that postpartum reproductive efficiency depends on the energy status of cows. Number of days to starst of ovarial activity and days to firs visible oestrus negatively corelated with glucose concentration and positively with value of NEFA and BHB.Reproduktivna efikasnost krava na farmama zavisi od nastanka postpartalne ovarijalne aktivnosti i pojave vidljivih estrusa. Krave se nalaze u negativnom energetskom bilansu u početku laktacije. Predpostavili smo da negativni energetski bilans negativno utiče na nastanak postpartalne ovarijane aktivnosti i nastanka vidljivog estrusa. Formirane su 2 grupe krava: na osnovu ovarijalne aktivnosti (krave koje pokazuju ovarijalnu aktivnost do 30. dana posle partusa i krave koje su ovarijalnu aktivnost pokazale kasnije) i na osnovu vidljivog postpartalnog estrusa (krave koje su pokazale klinički vidljiv estrus do 70. dana posle partusa i krave koje su prvi estrus pokazale kasnije). Vršeno je ispitivanje parametara metaboličkog profila u prvoj, četvrtoj i osmoj nedelji posle partusa. Krave sa kvalitetnijom reproduktivnom efikasnošću imaju nižu koncentraciju neesterifikovanih masnih kiselina i ketona i višu koncentaciju glukoze u prvoj i četvrtoj nedelji posle teljenja. Nađena je pozitivna korelacija između vrednosti NEFA i BHB, a negativna korelacija glukoze i momenta kada je započela ovarijalna aktivnost, odnosno kada je uočen prvi klinički vidljiv estru

Preclinical Testing of a Novel Niclosamide Stearate Prodrug Therapeutic (NSPT) shows efficacy against Osteosarcoma

Therapeutic advances for osteosarcoma (OS) have stagnated over the past several decades, leading to an unmet clinical need for patients. The purpose of this study was to develop a novel therapy for OS by reformulating and validating niclosamide, an established anthelminthic agent, as a Niclosamide Stearate Prodrug Therapeutic (NSPT). We sought to improve the low and inefficient clinical bioavailability of oral dosing, especially for the relatively hydrophobic classes of anti-cancer drugs. Nanoparticles were fabricated by rapid-solvent shifting and verified using dynamic light scattering and UV-vis spectrophotometry. NSPT efficacy was then studied in vitro for cell-viability, cell-proliferation, intracellular-signaling by western blot; ex vivo pulmonary metastatic assay model; and in vivo PK and lung mouse metastatic model of OS. NSPT formulation stabilizes niclosamide stearate against hydrolysis and delays enzymolysis; increases circulation in vivo with t1/2 ~5 h; reduces cell-viability and cell-proliferation in human and canine OS cells in vitro at 0.2 - 2 µM IC50; inhibits recognized growth pathways, and induces apoptosis at 20µM; eliminates metastatic lesions in the ex-vivo lung metastatic model; and, when injected intravenously (i.v.) at 50mg/kg weekly, it prevents metastatic spread in the lungs in a mouse model of OS over 30 days. In conclusion, niclosamide was optimized for preclinical drug delivery as a unique prodrug nanoparticle injected i.v. at 50mg/kg (1.9mM). This increased bioavailability of niclosamide in the blood stream prevented metastatic disease in the mouse. This chemotherapeutic strategy is now ready for canine trials, and if successful, will be targeted for human trials in OS patients

2-Hydroxyglutarate Production, but Not Dominant Negative Function, Is Conferred by Glioma-Derived NADP+-Dependent Isocitrate Dehydrogenase Mutations

Gliomas frequently contain mutations in the cytoplasmic NADP(+)-dependent isocitrate dehydrogenase (IDH1) or the mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDH2). Several different amino acid substitutions recur at either IDH1 R132 or IDH2 R172 in glioma patients. Genetic evidence indicates that these mutations share a common gain of function, but it is unclear whether the shared function is dominant negative activity, neomorphic production of (R)-2-hydroxyglutarate (2HG), or both.We show by coprecipitation that five cancer-derived IDH1 R132 mutants bind IDH1-WT but that three cancer-derived IDH2 R172 mutants exert minimal binding to IDH2-WT. None of the mutants dominant-negatively lower isocitrate dehydrogenase activity at physiological (40 µM) isocitrate concentrations in mammalian cell lysates. In contrast to this, all of these mutants confer 10- to 100-fold higher 2HG production to cells, and glioma tissues containing IDH1 R132 or IDH2 R172 mutations contain high levels of 2HG compared to glioma tissues without IDH mutations (54.4 vs. 0.1 mg 2HG/g protein).Binding to, or dominant inhibition of, WT IDH1 or IDH2 is not a shared feature of the IDH1 and IDH2 mutations, and thus is not likely to be important in cancer. The fact that the gain of the enzymatic activity to produce 2HG is a shared feature of the IDH1 and IDH2 mutations suggests that this is an important function for these mutants in driving cancer pathogenesis