ABSTRACT
Neuromuscular excitability is a vital body function, and Mg2+ is an essential regulatory cation for the function of excitable membranes. Loss of Mg2+ homeostasis disturbs fluxes of other cations across cell membranes, leading to pathophysiological electrogenesis, which can eventually cause vital threat to the patient. Chronic subclinical Mg2+ deficiency is an increasingly prevalent condition in the general population. It is associated with an elevated risk of cardiovascular, respiratory and neurological conditions and an increased mortality. Magnesium favours bronchodilation (by antagonizing Ca2+ channels on airway smooth muscle and inhibiting the release of endogenous bronchoconstrictors). Magnesium exerts antihypertensive effects by reducing peripheral vascular resistance (increasing endothelial NO and PgI2 release and inhibiting Ca2+ influx into vascular smooth muscle). Magnesium deficiency disturbs heart impulse generation and propagation by prolonging cell depolarization (due to Na+/K+ pump and Kir channel dysfunction) and dysregulating cardiac gap junctions, causing arrhythmias, while prolonged diastolic Ca2+ release (through leaky RyRs) disturbs cardiac excitation-contraction coupling, compromising diastolic relaxation and systolic contraction. In the brain, Mg2+ regulates the function of ion channels and neurotransmitters (blocks voltage-gated Ca2+ channel-mediated transmitter release, antagonizes NMDARs, activates GABAARs, suppresses nAChR ion current and modulates gap junction channels) and blocks ACh release at neuromuscular junctions. Magnesium exerts multiple therapeutic neuroactive effects (antiepileptic, antimigraine, analgesic, neuroprotective, antidepressant, anxiolytic, etc.). This review focuses on the effects of Mg2+ on excitable tissues in health and disease. As a natural membrane stabilizer, Mg2+ opposes the development of many conditions of hyperexcitability. Its beneficial recompensation and supplementation help treat hyperexcitability and should therefore be considered wherever needed.
ABSTRACT
MOTIVATION: Timetrees depict evolutionary relationships between species and the geological times of their divergence. Hundreds of research articles containing timetrees are published in scientific journals every year. The TimeTree (TT) project has been manually locating, curating and synthesizing timetrees from these articles for almost two decades into a TimeTree of Life, delivered through a unique, user-friendly web interface (timetree.org). The manual process of finding articles containing timetrees is becoming increasingly expensive and time-consuming. So, we have explored the effectiveness of text-mining approaches and developed optimizations to find research articles containing timetrees automatically. RESULTS: We have developed an optimized machine learning system to determine if a research article contains an evolutionary timetree appropriate for inclusion in the TT resource. We found that BERT classification fine-tuned on whole-text articles achieved an F1 score of 0.67, which we increased to 0.88 by text-mining article excerpts surrounding the mentioning of figures. The new method is implemented in the TimeTreeFinder (TTF) tool, which automatically processes millions of articles to discover timetree-containing articles. We estimate that the TTF tool would produce twice as many timetree-containing articles as those discovered manually, whose inclusion in the TT database would potentially double the knowledge accessible to a wider community. Manual inspection showed that the precision on out-of-distribution recently published articles is 87%. This automation will speed up the collection and curation of timetrees with much lower human and time costs. AVAILABILITY AND IMPLEMENTATION: https://github.com/marija-stanojevic/time-tree-classification. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Subject(s)
Biological Evolution , Data Mining , Humans , Phylogeny , Databases, Factual , Machine LearningABSTRACT
Takayasu Arteritis (TA) is characterized by granulomatous panarteritis, vessel wall fibrosis, and irreversible vascular impairment. The aim of this study is to explore the usefulness of the Enhanced Liver Fibrosis score (ELF), procollagen-III aminoterminal propeptide (PIIINP), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), and hyaluronic acid (HA) in assessing vascular damage in TA patients. ELF, PIIINP, TIMP-1, and HA were measured in 24 TA patients, and the results were correlated with the clinical damage indexes (VDI and TADS), an imaging damage score (CARDS), and disease activity scores (NIH and ITAS2010). A mean ELF score 8.42 (±1.12) and values higher than 7.7 (cut-off for liver fibrosis) in 21/24 (87.5%) of patients were detected. The VDI and TADS correlated significantly to ELF (p < 0.01). Additionally, a strong association across ELF and CARDS (p < 0.0001), PIIINP and CARDS (p < 0.001), and HA and CARDS (p < 0.001) was observed. No correlations of the tested biomarkers with inflammatory parameters, NIH, and ITAS2010 scores were found. To our knowledge, this is the first study that suggests the association of the serum biomarkers PIIINP, HA, and ELF score with damage but not with disease activity in TA patients. The ELF score and PIIINP may be useful biomarkers reflecting an ongoing fibrotic process and quantifying vascular damage.
ABSTRACT
BACKGROUND: Takayasu arteritis (TA) is a systemic vasculitis, affecting mainly the aorta and its branches. OBJECTIVE: To analyze the HLA class I and class II alleles in patients with TA and explore their relationship with clinical and demographic characteristics, and potential significance in prognosis. METHODS: Twenty-five, unrelated TA patients were genotyped for HLA-A, HLA-B, HLA-C, HLA-DRB1, and the HLA-DQB1 loci. The frequencies of the HLA-A, HLA-B, and the HLA-DRB1 were compared with a control group of 1992, while the HLA-C and the HLA-DQB1 were compared with a group of 159 healthy, unrelated individuals. RESULTS: Among TA patients, 5/25 (20%) were identified as the HLA-B*52 carriers. There was a significant difference in the HLA-B*52 allele frequency in the TA patients (10%) compared with the healthy controls (1.2%). Moreover, presence of the HLA-B*52 was associated with significantly earlier disease onset, more severe clinical presentations, and a poorer response to treatment. The HLA-C*03 was detected in 32% of patients and was present exclusively in those with a clinically mild form of the TA, indicating a putative protective effect. CONCLUSION: These findings indicate that the HLA-B*52 allele contributes to a higher susceptibility to the TA whereas the HLA-C*03, can be a protective factor in the TA.
Subject(s)
Genes, MHC Class II , Genes, MHC Class I , Takayasu Arteritis , Alleles , Gene Frequency , Genetic Predisposition to Disease , HLA-B Antigens/genetics , HLA-DQ beta-Chains/genetics , HLA-DRB1 Chains/genetics , Haplotypes , Humans , Prognosis , Takayasu Arteritis/diagnosis , Takayasu Arteritis/geneticsABSTRACT
KEY POINTS: Stimulation of postsynaptic muscarinic receptors was shown to excite principal hippocampal neurons by modulating several membrane ion conductances. We show here that activation of postsynaptic muscarinic receptors also causes neuronal excitation by inhibiting Na+ /K+ -ATPase activity. Muscarinic Na+ /K+ -ATPase inhibition is mediated by two separate signalling pathways that lead downstream to enhanced Na+ /K+ -ATPase phosphorylation by activating protein kinase C and protein kinase G. Muscarinic excitation through Na+ /K+ -ATPase inhibition is probably involved in cholinergic modulation of hippocampal activity and may turn out to be a widespread mechanism of neuronal excitation in the brain. ABSTRACT: Stimulation of muscarinic cholinergic receptors on principal hippocampal neurons enhances intrinsic neuronal excitability by modulating several membrane ion conductances. The electrogenic Na+ /K+ -ATPase (NKA; the 'Na+ pump') is a ubiquitous regulator of intrinsic neuronal excitability, generating a hyperpolarizing current to thwart excessive neuronal firing. Using electrophysiological and pharmacological methodologies in rat hippocampal slices, we show that neuronal NKA pumping activity is also subjected to cholinergic regulation. Stimulation of postsynaptic muscarinic, but not nicotinic, cholinergic receptors activates membrane-bound phospholipase C and hydrolysis of membrane-integral phosphatidylinositol 4,5-bisphosphate into diacylglycerol (DAG) and inositol 1,4,5-triphosphate (IP3 ). Along one signalling pathway, DAG activates protein kinase C (PKC). Along a second signalling pathway, IP3 causes Ca2+ release from the endoplasmic reticulum, facilitating nitric oxide (NO) production. The rise in NO levels stimulates cGMP synthesis by guanylate-cyclase, activating protein kinase G (PKG). The two pathways converge to cause partial NKA inhibition through enzyme phosphorylation by PKC and PKG, leading to a marked increase in intrinsic neuronal excitability. This novel mechanism of neuronal NKA regulation probably contributes to the cholinergic modulation of hippocampal activity in spatial navigation, learning and memory.
Subject(s)
Hippocampus , Sodium-Potassium-Exchanging ATPase , Animals , Cholinergic Agents , Cyclic GMP-Dependent Protein Kinases , Hippocampus/metabolism , Neurons/metabolism , Rats , Sodium-Potassium-Exchanging ATPase/metabolismABSTRACT
OBJECTIVE: We sought to predict if patients with type 2 diabetes mellitus (DM2) would develop 10 selected complications. Accurate prediction of complications could help with more targeted measures that would prevent or slow down their development. MATERIALS AND METHODS: Experiments were conducted on the Healthcare Cost and Utilization Project State Inpatient Databases of California for the period of 2003 to 2011. Recurrent neural network (RNN) long short-term memory (LSTM) and RNN gated recurrent unit (GRU) deep learning methods were designed and compared with random forest and multilayer perceptron traditional models. Prediction accuracy of selected complications were compared on 3 settings corresponding to minimum number of hospitalizations between diabetes diagnosis and the diagnosis of complications. RESULTS: The diagnosis domain was used for experiments. The best results were achieved with RNN GRU model, followed by RNN LSTM model. The prediction accuracy achieved with RNN GRU model was between 73% (myocardial infarction) and 83% (chronic ischemic heart disease), while accuracy of traditional models was between 66% - 76%. DISCUSSION: The number of hospitalizations was an important factor for the prediction accuracy. Experiments with 4 hospitalizations achieved significantly better accuracy than with 2 hospitalizations. To achieve improved accuracy deep learning models required training on at least 1000 patients and accuracy significantly dropped if training datasets contained 500 patients. The prediction accuracy of complications decreases over time period. Considering individual complications, the best accuracy was achieved on depressive disorder and chronic ischemic heart disease. CONCLUSIONS: The RNN GRU model was the best choice for electronic medical record type of data, based on the achieved results.
Subject(s)
Algorithms , Deep Learning , Diabetes Complications , Diabetes Mellitus, Type 2/complications , Risk Assessment/methods , Decision Trees , Humans , Neural Networks, Computer , PrognosisABSTRACT
Recent studies suggest that 2,4-DABA, a neurotoxic excitatory amino acid present in virtually all environments, but predominantly in aquatic ecosystems may be a risk factor for development of neurodegenerative diseases in animals and humans. Despite its neurotoxicity and potential environmental importance, mechanisms underlying the excitatory and putative excitotoxic action of 2,4-DABA in neurons are still unexplored. We previously reported on extensive two-stage membrane depolarization and functional disturbances in leech Retzius neurons induced by 2,4-DABA. Current study presents the first detailed look into the electrophysiological processes leading to this depolarization. Intracellular recordings were performed on Retzius neurons of the leech Haemopis sanguisuga using glass microelectrodes and input membrane resistance (IMR) was measured by injecting hyperpolarizing current pulses through these electrodes. Results show that the excitatory effect 2,4-DABA elicits on neurons' membrane potential is dependent on sodium ions. Depolarizing effect of 5·10-3 mol/L 2,4-DABA in sodium-free solution was significantly diminished by 91% reducing it to 3.26⯱â¯0.62â¯mV and its two-stage nature was abrogated. In addition to being sodium-dependent, the depolarization of membrane potential induced by this amino acid is coupled with an increase of membrane permeability, as 2,4-DABA decreases IMR by 8.27⯱â¯1.47â¯MΩ (67.60%). Since present results highlight the role of sodium ions, we investigated the role of two putative sodium-dependent mechanisms in 2,4-DABA-induced excitatory effect - activation of ionotropic glutamate receptors and the electrogenic transporter for neutral amino acids. Excitatory effect of 5·10-3 mol/L 2,4-DABA was partially blocked by 10-5 mol/L 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) a non-NMDA receptor antagonist as the first stage of membrane depolarization was significantly reduced by 2.59⯱â¯0.98â¯mV (40%), whilst second stage remained unaltered. Moreover, involvement of the sodium-dependent transport system for neutral amino acids was investigated by equimolar co-application of 5·10-3 mol/L 2,4-DABA and L-alanine, a competitive inhibitor of this transporter. Although L-alanine exhibited no effect on the first stage of membrane depolarization elicited by 2,4-DABA, it substantially reduced the second stage (the overall membrane depolarization) from 39.63⯱â¯2.22â¯mV to 16.28⯱â¯2.58â¯mV, by 58.92%. We therefore propose that the electrophysiological effect of 2,4-DABA on Retzius neurons is mediated by two distinct mechanisms, i.e. by activation of ionotropic glutamate receptor that initiates the first stage of membrane depolarization followed by the stimulation of an electrogenic sodium-dependent neutral amino acid transporter, leading to additional influx of positive charge into the cell and the second stage of depolarization.
Subject(s)
Aminobutyrates/toxicity , Electrophysiological Phenomena/drug effects , Leeches/physiology , Neurons/drug effects , 6-Cyano-7-nitroquinoxaline-2,3-dione/pharmacology , Alanine/pharmacology , Amino Acid Transport System A/antagonists & inhibitors , Animals , Glutamic Acid/metabolism , Leeches/drug effects , Membrane Potentials/drug effects , Neurons/physiologyABSTRACT
The kidneys are recognized as a major target of cadmium-induced toxicity. However, all mechanisms that are involved in the early stages of cadmium nephrotoxicity, particularly considering low micromolar concentrations of cadmium ions (Cd2+) are still unknown. Therefore, the aim of this study was to investigate the effects of peritubular acute exposure to micromolar Cd2+ concentration (2.3⯵mol/L) on the rapid depolarization and the rate of slow repolarization of peritubular membrane potential difference (PD), induced by luminal application of L-alanine in proximal tubular cells of frog kidney. The results showed that the luminal application of L-alanine rapidly depolarized the peritubular membrane PD of -42.00⯱â¯11.68â¯mV by 23.89⯱â¯4.15â¯mV with an average rate of slow repolarization of 5.64⯱â¯0.81â¯mV/min. Additionally, peritubular acute exposure to Cd2+ induced change in rapid depolarization of peritubular membrane PD of -53.33⯱â¯13.01â¯mV by 18.78⯱â¯3.31â¯mV (Pâ¯<â¯0.01) after luminal application of L-alanine. Also, peritubular acute exposure to Cd2+ led to statistically significant decrease in the rate of slow repolarization of peritubular membrane PD (3.53⯱â¯0.35â¯mV/min; Pâ¯<â¯0.05). In conclusion, these results suggest that peritubular acute exposure to low micromolar Cd2+ concentration decreased the rapid depolarization and the rate of slow repolarization of peritubular membrane PD induced by luminal application of L-alanine. This is followed by reduced luminal sodium-coupled transport of L-alanine and this change may be one of the possible mechanisms involved in the early stages of Cd2+-induced nephrotoxicity.
Subject(s)
Alanine/metabolism , Cadmium/pharmacology , Kidney Tubules, Proximal/drug effects , Animals , Biological Transport/drug effects , Cadmium/administration & dosage , Female , Kidney Tubules, Proximal/metabolism , Male , Membrane Potentials/drug effects , Rana esculentaABSTRACT
Oxidative stress and the generation of reactive oxygen species (ROS) play an important role in cellular damage. Electrophysiological analyses have shown that membrane transport proteins are susceptible to ROS. In the present study, oxidative stress was induced in Retzius nerve cells of the leechHaemopis sanguisugaby bath application of 1â mM of hydrogen peroxide (H2O2) and 0.02â mM of copper (Cu) for 20â min. The H2O2/Cu(II) produced considerable changes in the electrical properties of the Retzius nerve cells. Intracellular recording of the resting membrane potential revealed that the neuronal membrane was depolarized in the presence of H2O2/Cu(II). We found that the amplitude of action potentials decreased, while the duration augmented in a progressive way along the drug exposure time. The combined application of H2O2and Cu(II) caused an initial excitation followed by depression of the spontaneous electrical activity. Voltage-clamp recordings revealed a second effect of the oxidant, a powerful inhibition of the outward potassium channels responsible for the repolarization of action potentials. The neurotoxic effect of H2O2/Cu(II) on the spontaneous spike electrogenesis and outward K(+)current of Retzius nerve cells was reduced in the presence of hydroxyl radical scavengers, dimethylthiourea and dimethyl sulfoxide, but not mannitol. This study provides evidence for the oxidative modification of outward potassium channels in Retzius nerve cells. The oxidative mechanism of the H2O2/Cu(II) system action on the electrical properties of Retzius neurons proposed in this study might have a wider significance, referring not only to leeches but also to mammalian neurons.
ABSTRACT
This paper promotes the biometric classification system of plant cultivars, unique characteristics, in terms of the uranium (U) uptake, primarily in the function of the application for phytoremediation. It is known that the degree of adoption of U depends on the plant species and its morphological and physiological properties, but it is less known what impact have plants cultivars, sorts, and hybrids. Therefore, we investigated the U adoption in four cultivars of three plant species (corn, sunflower and soy bean). "Vegetation experiments were carried out in a plastic-house filled with soil (0.66 mgU) and with tailing (15.3 mgU kg(-1)) from closed uranium mine Gabrovnica-Kalna southeast of Serbia". Principal Component Analysis (PCA), Cluster Analysis (CA) and analysis of variance (ANOVA) were used for assessing the effect of different substrates cultivars, plant species and plant organs (root or shoot) on U uptake. Obtained results showed that a difference in U uptake by three investigated plant species depends not only of the type of substrate types and plant organs but also of their cultivars. Biometrics techniques provide a good opportunity for a better understanding the behavior of plants and obtaining much more useful information from the original data.
Subject(s)
Glycine max/metabolism , Helianthus/metabolism , Soil Pollutants, Radioactive/metabolism , Uranium/metabolism , Zea mays/metabolism , Biodegradation, Environmental , Biometry , Principal Component AnalysisABSTRACT
Large amounts of fruit seeds, especially peach, are discarded annually in juice or conserve producing industries which is a potential waste of valuable resource and serious disposal problem. Regarding the fact that peach seeds can be obtained as a byproduct from processing companies their exploitation should be greater and, consequently more information of cultivars' kernels and their composition is required. A total of 25 samples of kernels from various peach germplasm (including commercial cultivars, perspective hybrids and vineyard peach accessions) differing in origin and ripening time were characterized by evaluation of their sugar composition. Twenty characteristic carbohydrates and sugar alcohols were determined and quantified using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC/PAD). Sucrose, glucose and fructose are the most important sugars in peach kernels similar to other representatives of the Rosaceae family. Also, high amounts of sugars in seeds of promising hybrids implies that through conventional breeding programs peach kernels with high sugar content can be obtained. In addition, by the means of several pattern recognition methods the variables that discriminate peach kernels arising from diverse germplasm and different stage of maturity were identified and successful models for further prediction were developed. Sugars such as ribose, trehalose, arabinose, galactitol, fructose, maltose, sorbitol, sucrose, iso-maltotriose were marked as most important for such discrimination.
Subject(s)
Carbohydrates/analysis , Prunus persica , Seeds/chemistry , Chromatography, High Pressure Liquid , Food Handling , Fructose/analysis , Fruit/chemistry , Glucose/analysis , Prunus persica/chemistry , Prunus persica/classification , Prunus persica/growth & development , Sucrose/analysis , Sweetening Agents , Waste ProductsABSTRACT
The effects of Mg2+ on Ni(2+)-induced epileptiform bursting activity and input membrane resistance during this activity of leech Retzius neurons were examined using intracellular recordings. To induce epileptiform activity, 3 mmol/l NiCl2 was added into superfusing Ringer (Ri) saline. To test for dose-dependence of the effects of Mg2+ on the induced epileptiform activity, MgCl2 was added in concentrations from 1 mmol/l to 20 mmol/l Mg2+ to the Ni(2+)-containing Ri saline. Input membrane resistance (IMR) was measured in standard Ri, Ni2+ Ri and 20 mmol/l Mg2+Ni2+ Ri saline. Superfusion with Ni2+ Ri induced epileptiform bursting activity characterized by generation of paroxysmal depolarization shifts (PDSs). Parameters of epileptiform activity including PDS frequency, PDS duration, PDS amplitude and the number of spikes/PDS were measured. Magnesium suppressed Ni(2+)-induced epileptiform activity, significantly reducing values of all parameters observed in a concentration-dependent manner. The highest concentration applied of 20 mmol/l Mg2+ completely eliminated epileptiform activity. To test for the effect of Mg2+ on membrane conductance during bursting, IMR was measured. Magnesium significantly increased IMR during bursting suppression.
Subject(s)
Leeches/cytology , Magnesium/pharmacology , Neurons/drug effects , Neurons/physiology , Animals , Cells, Cultured , Neurons/cytology , Nickel/pharmacologyABSTRACT
INTRODUCTION: Vesicovaginal fistula can occur after delivery, gynaecologic or urologic surgery, irradiation therapy or as destruction caused by a tumour or trauma. The main problem after irradiation is decreased elasticity of the tissue around the fistula. We present our experience in the treatment of three patients with vesicovaginal fistula using a labia maiora skin flap. CASE OUTLINE: From May 2007 to January 2008 three patients with vesicovaginal fistula were treated using labia maiora skin flap. The fistulae occurred after mean 19 months (11, 20 and 26 months) following irradiation therapy applied to treat malignant disease. The mean age of the patients was 54 years (47, 53 and 62 years). The mean diameter of the fistulae was 3.5 cm (2, 4 and 4.5 cm). Using transvaginal approch, all devitalized and fibrous tissue was removed with the closure of the bladder wall. The labia maiora skin flap with good vascularization was transposed to close the defect and anastomozed to the vagina. The mean follow-up was 16 months (13, 17 and 18 months). Labia maiora skin flap size was mean 3.7 cm (2.6, 3.7 and 4.8 cm). We achieved satisfactory outcome in all patients. There were neither postoperative complications nor fistula recurrence. CONCLUSION: Labia maiora skin flap presents a good alternative for surgical treatment of vesicovaginal fistula. The flap is more adequate for larger defects and for the repair of fibrously changed vaginal wall which is present after irradiation therapy.
Subject(s)
Radiation Injuries/surgery , Surgical Flaps , Vesicovaginal Fistula/surgery , Female , Humans , Middle Aged , Radiation Injuries/complications , Vesicovaginal Fistula/etiologyABSTRACT
BACKGROUND/AIM: Myomas of the uterus, the most common benign tumors, have been studied for decades from the aspects of different basic and clinical disciplines. Despite this fact, their pathogenesis is still poorly understood. The aim of this study was to determine immunocytochemical characteristics of smooth muscle cells and connective tissue components of submucosal myomas of the uterus. METHOD: During the course of this study, 25 samples of submucosal myomas of the uterus were analyzed, all of them obtained during the surgery, after abdominal histerctomy by Aldridge. The samples were fixed in 4% formalin and embedded in paraffin. Sections of 5 microm thickness were stained immunocytochemically using the DAKO LSAB+/HRP technique to identify alpha-smooth muscle actin (alpha-SMA), vimentin, desmin, CD34, CD45, CD68 and PCNA (DAKO specification). RESULTS: Our results suggest that submucosal myomas of the uterus are build-up of smooth muscle cells which are immunoreactive to alpha-SMA and desmin, but also to a certain number of smooth muscle cells which are immunoreactive to alpha-SMA and vimentin. Some of vimentin-immunoreactive cells also show an immunoreactivity of PCNA. In the build-up of connective stroma CD34-immunoreactive fibroblasts and neovascular formations are also present. By examining the distribution of CD45 antigen, at all the analyzed samples we observed a weak reaction. CONCLUSION: Submucosal myomas of the uterus are made-up of smooth muscle cells of the highly differentiated contractile phenotype (alpha-SMA- and desmin-immunoreactivity), as well as smooth muscle cell of the synthetic phenotype which proliferate (alpha-SMA-, vimentin- and PCNA-immunoreactivity). In submucosal myoma of the uterus there is a significant presence of connective tissue as a result of synthetic activity of fibroblasts, which clearly differ in their immunocytochemical characteristics from smooth muscle cells of the synthetic phenotype.
Subject(s)
Leiomyoma/metabolism , Uterine Neoplasms/metabolism , Actins/metabolism , Antigens, CD34/metabolism , Female , Humans , Immunohistochemistry , Intermediate Filament Proteins/metabolism , Leiomyoma/pathology , Muscle, Smooth/metabolism , Muscle, Smooth/pathology , Proliferating Cell Nuclear Antigen/metabolism , Uterine Neoplasms/pathologyABSTRACT
In the present study we have examined effects of ethanol and magnesium on Ni(2+)-induced bursting of leech Retzius cells. Saline with 3 mmol/l NiCl2 induced spontaneous bursting activity, characterized by rapid depolarizations to a plateau level during which bursts of action potentials occurred. To test for the mechanism of bursting initiation external Na+ was completely removed. Removal of external Na(+) in presence of 3 mmol/l NiCl2 terminated the bursting activity. Application of 2% ethanol solution significantly decreased the bursting frequency, duration and amplitude of depolarization plateaus, and the number of spikes per plateau. Solution containing 10 mmol/l Mg2+ almost completely abolished the oscillatory activity of the neurons and completely suppressed action potential generation. We conclude that ethanol and magnesium suppress Ni(2+)-induced epileptic activity.
Subject(s)
Ethanol/pharmacology , Leeches/cytology , Magnesium/pharmacology , Neurons/cytology , Neurons/drug effects , Nickel/pharmacology , Animals , Dose-Response Relationship, Drug , Ion Channels/metabolism , Neurons/physiology , Seizures/metabolism , Seizures/pathology , Seizures/physiopathology , Sodium/pharmacology , Synaptic Transmission/drug effectsABSTRACT
INTRODUCTION: One of the most dramatic conditions in obstetrics is definitely bleeding from the uterus which fails to compress. This condition is known as postpartum atony. When such a condition is diagnosed, the obstetrician has a choice of several conservative methods to stimulate the uterus to contract and several surgical methods to stop the bleeding. The most extreme measure used to save the patient's life and stop the bleeding is hysterectomy. This surgery is characterized by high morbidity, primarily by the loss of woman's fertility. In order to avoid hysterectomy, several authors have introduced the compressive uterine suture technique into gynaecological practice. OBJECTIVE: The aim of the paper is to demonstrate the technique of applying compressive uterine suture after delivery to stop excessive bleeding, and to present results obtained by this technique. METHODS: The paper explains the technique of applying compressive suture to the atonic uterus in cases when all other procedures to stop excessive bleeding after delivery fail. Since uterine atony is the main reason for excessive and uncontrollable bleeding after childbirth, the need to perform such surgery is rather common. Authors demonstrate the technique of applying four compressive sutures which prevent uterus dilation and thus stop the bleeding. RESULTS: Compressive suture technique was used by the authors eight times, seven of which during caesarean section and one after spontaneous delivery. All patients had normal postpartum period and normal involution of the uterus. CONCLUSION: Although this surgery requires a skillful and experienced obstetrician, the authors find it rather easy to perform and it is suggested to be applied in all cases of uterine atony when excessive bleeding cannot be stopped by other any other method except hysterectomy. This surgical procedure saves the uterus and facilitates quick and easy patient's recovery.
Subject(s)
Hemostasis, Surgical , Postpartum Hemorrhage/surgery , Suture Techniques , Female , Humans , Hysterectomy , PregnancyABSTRACT
The hydrogels prepared by free radical copolymerization of acrylamide and itaconic acid were investigated with regard to their composition and crosslinking degree to find materials with satisfactory swelling and drug release properties. Samples were characterized by measuring the swelling behavior and in vitro release of paracetamol as a model drug in aqueous media with different pH values. The two-factor, three-level experimental design and response surface methodology were applied to statistically evaluate the influence of investigated factors.