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1.
Front Netw Physiol ; 2: 1036832, 2022.
Article in English | MEDLINE | ID: mdl-36926085

ABSTRACT

Acute and chronic insomnia have different causes and may require different treatments. They are investigated with multi-night nocturnal actigraphy data from two sleep studies. Two different wrist-worn actigraphy devices were used to measure physical activities. This required data pre-processing and transformations to smooth the differences between devices. Statistical, power spectrum, fractal and entropy analyses were used to derive features from the actigraphy data. Sleep parameters were also extracted from the signals. The features were then submitted to four machine learning algorithms. The best performing model was able to distinguish acute from chronic insomnia with an accuracy of 81%. The algorithms were then used to evaluate the acute and chronic groups compared to healthy sleepers. The differences between acute insomnia and healthy sleep were more prominent than between chronic insomnia and healthy sleep. This may be associated with the adaptation of the physiology to prolonged periods of disturbed sleep for individuals with chronic insomnia. The new model is a powerful addition to our suite of machine learning models aiming to pre-screen insomnia at home with wearable devices.

2.
R Soc Open Sci ; 8(6): 202264, 2021 Jun 16.
Article in English | MEDLINE | ID: mdl-34150313

ABSTRACT

We propose a novel machine learning-based method for analysing multi-night actigraphy signals to objectively classify and differentiate nocturnal awakenings in individuals with chronic insomnia (CI) and their cohabiting healthy partners. We analysed nocturnal actigraphy signals from 40 cohabiting couples with one partner seeking treatment for insomnia. We extracted 12 time-domain dynamic and nonlinear features from the actigraphy signals to classify nocturnal awakenings in healthy individuals and those with CI. These features were then used to train two machine learning classifiers, random forest (RF) and support vector machine (SVM). An optimization algorithm that incorporated the predicted quality of each night for each individual was used to classify individuals into CI or healthy sleepers. Using the proposed actigraphic signal analysis technique, coupled with a rigorous leave-one-out validation approach, we achieved a classification accuracy of 80% (sensitivity: 76%, specificity: 82%) in classifying CI individuals and their healthy bed partners. The RF classifier (accuracy: 80%) showed a better performance than SVM (accuracy: 75%). Our approach to analysing the multi-night nocturnal actigraphy recordings provides a new method for screening individuals with CI, using wrist-actigraphy devices, facilitating home monitoring.

3.
Hippokratia ; 23(4): 186-189, 2019.
Article in English | MEDLINE | ID: mdl-32742172

ABSTRACT

INTRODUCTION: Isolated infrarenal abdominal aortic dissection is a rare clinical entity. Most cases are treated by endovascular techniques, and open surgery is seldom necessary. CASE DESCRIPTION: We present a rare case of spontaneous symptomatic infrarenal aortic dissection with leading symptom right leg ischemia. We opted for abdominal surgery as the attempt for open surgical fenestration of the dissecting flap exit through right femoral access was unsuccessful. Dacron vascular prosthesis was implanted with aortoiliofemoral bypass on the right side. One of the two accessory right renal arteries was ligated, which led to a confined zone of renal ischemia. Upon follow-up, complete restoration of the renal parenchyma was observed; kidney function remained unaffected. CONCLUSION: By infrarenal abdominal aortic dissection with accessory renal arteries, abdominal surgery with selective clamping is a reliable therapeutic approach allowing maximal preservation of renal blood flow. HIPPOKRATIA 2019, 23(4): 186-189.

4.
Bull Math Biol ; 81(1): 277-311, 2019 01.
Article in English | MEDLINE | ID: mdl-30411251

ABSTRACT

Experimental studies of the flowering of Arabidopsis thaliana have shown that a large complex gene regulatory network (GRN) is responsible for its regulation. This process has been mathematically modelled with deterministic differential equations by considering the interactions between gene activators and inhibitors (Valentim et al. in PLoS ONE 10(2):e0116973, 2015; van Mourik et al. in BMC Syst Biol 4(1):1, 2010). However, due to complexity of the model, the properties of the network and the roles of the individual genes cannot be deducted from the numerical solution the published work offers. Here, we propose simplifications of the model, based on decoupling of the original GRN to motifs, described with three and two differential equations. A stable solution of the original model is sought by linearisation of the original model which contributes to further investigation of the role of the individual genes to the flowering. Furthermore, we study the role of noise by introducing and investigating two types of stochastic elements into the model. The deterministic and stochastic nonlinear dynamic models of Arabidopsis flowering time are considered by following the deterministic delayed model introduced in Valentim et al. (2015). Steady-state regimes and stability of the deterministic original model are investigated analytically and numerically. By decoupling some concentrations, the system was reduced to emphasise the role played by the transcription factor Suppressor of Overexpression of Constants1 ([Formula: see text]) and the important floral meristem identity genes, Leafy ([Formula: see text]) and Apetala1 ([Formula: see text]). Two-dimensional motifs, based on the dynamics of [Formula: see text] and [Formula: see text], are obtained from the reduced network and parameter ranges ensuring flowering are determined. Their stability analysis shows that [Formula: see text] and [Formula: see text] are regulating each other for flowering, matching experimental findings. New sufficient conditions of mean square stability in the stochastic model are obtained using a stochastic Lyapunov approach. Our numerical simulations demonstrate that the reduced models of Arabidopsis flowering time, describing specific motifs of the GRN, can capture the essential behaviour of the full system and also introduce the conditions of flowering initiation. Additionally, they show that stochastic effects can change the behaviour of the stability region through a stability switch. This study thus contributes to a better understanding of the role of [Formula: see text] and [Formula: see text] in Arabidopsis flowering.


Subject(s)
Arabidopsis/growth & development , Arabidopsis/genetics , Models, Biological , Arabidopsis Proteins/genetics , Computer Simulation , Flowers/genetics , Flowers/growth & development , Gene Expression Regulation, Developmental , Gene Expression Regulation, Plant , Gene Regulatory Networks , Genes, Plant , Linear Models , MADS Domain Proteins/genetics , Mathematical Concepts , Nonlinear Dynamics , Stochastic Processes , Time Factors , Transcription Factors/genetics
5.
J Theor Biol ; 418: 66-76, 2017 04 07.
Article in English | MEDLINE | ID: mdl-28130099

ABSTRACT

We study the effect of diabetic deficiencies on the production of an oscillatory ultradian regime using a deterministic nonlinear model which incorporates two physiological delays. It is shown that insulin resistance impairs the production of oscillations by dampening the ultradian cycles. Four strategies for restoring healthy regulation are explored. Through the introduction of an instantaneous glucose-dependent insulin response, explicit conditions for the existence of periodic solutions in the linearised model are formulated, significantly reducing the complexity of identifying an oscillatory regime. The model is thus shown to be suitable for representing the effect of diabetes on the oscillatory regulation and for investigating pathways to reinstating a physiological healthy regime.


Subject(s)
Biological Clocks , Blood Glucose/metabolism , Diabetes Mellitus/blood , Insulin/blood , Models, Biological , Humans
6.
Akush Ginekol (Sofiia) ; 55(4): 3-8, 2016.
Article in Bulgarian | MEDLINE | ID: mdl-29370486

ABSTRACT

In the recent years according to WHO, genital chlamydia is the mos't common sexually transmitted infection. Chlamydia Trachomatis is an intracellular parasite which target are the tubular epithelial cells of the urethra, endocervix, endometrium, endosalpinx, conjunctiva, synovial lining of the joints, Glisson's capsule of the liver Our study, as well as some international researches, shows that in the cases of genital chlamydia there are changes in the ovarian hormones (estradiol and progesterone), their impact on the immune system and their importance for the development and the complications of the infection with Chlamydia trachomatis. The physiological level of the steroid hormones in its turn contributes for the normalization of the local immunity and reduces the possibility of recurrences.


Subject(s)
Chlamydia Infections/blood , Chlamydia trachomatis/immunology , Hormones/blood , Steroids/blood , Chlamydia Infections/diagnosis , Chlamydia Infections/immunology , Chlamydia trachomatis/isolation & purification , Estradiol/blood , Estradiol/immunology , Female , Hormones/immunology , Humans , Immunity , Progesterone/blood , Progesterone/immunology , Prospective Studies , Steroids/immunology
8.
Akush Ginekol (Sofiia) ; 52 Suppl 2: 5-11, 2013.
Article in Bulgarian | MEDLINE | ID: mdl-24294754

ABSTRACT

Authors track current trends in preterm labor diagnostics. The emphasis is laid on biochemical tests for examination of fibronectin (fFN) and insulin-like growth factor-binding protein (IGFBP-1) in cervical and vaginal secretions, as well as ultrasound assessment of cervical length.


Subject(s)
Cervix Uteri/pathology , Fibronectins/analysis , Insulin-Like Growth Factor Binding Protein 1/analysis , Obstetric Labor, Premature/diagnosis , Vagina/pathology , Cervix Uteri/diagnostic imaging , Female , Humans , Obstetric Labor, Premature/diagnostic imaging , Pregnancy , Ultrasonography
9.
Endocr Regul ; 45(4): 175-81, 2011 Oct.
Article in English | MEDLINE | ID: mdl-22073946

ABSTRACT

OBJECTIVE: Deleterious effects of free radicals do not only result from the amount of free radicals produced but also are related to the efficiency and to the activities of enzymatic antioxidant systems. We investigated the effect of exogenous superoxide dismutase (SOD1) or Cu-chelating agent diethyldithiocarbamate (DDC) on the apoptosis (caspase-3 activity) of human granulosa luteinized cells (hGLC) in vitro. METHODS: The effects of SOD1 and DDC were studied using in vitro culture system, caspase-3 and the total SOD activity in hGLCs were measured using AcDEVD-PNA substrate and Beaushap and Fridovich methods, respectively, after 48 h of the culture period. RESULTS: The activity of SOD1 was the lowest in GLCs treated with 100 µM DDC as compared to control cells and to the cells supplemented with Cu, Zn-SOD or DDC (10 µM). The effect of DDC was associated with elevated caspase-3 activity as compared to control cells. CONCLUSIONS: It was demonstrated for the first time that the supplementation of cultured hGLCs with Cu2+, Zn2+-SOD (200 U/ml) maintains the viability of hGLCs via caspase-3 suppression.


Subject(s)
Cell Culture Techniques/methods , Fertilization in Vitro/methods , Granulosa Cells/cytology , Granulosa Cells/drug effects , Superoxide Dismutase/pharmacology , Apoptosis/drug effects , Caspase 3/metabolism , Cell Survival/drug effects , Chelating Agents/pharmacology , Culture Media/pharmacology , Ditiocarb/pharmacology , Female , Granulosa Cells/enzymology , Humans , Oxidative Stress/drug effects , Superoxide Dismutase-1
10.
Phys Rev Lett ; 102(1): 018102, 2009 Jan 09.
Article in English | MEDLINE | ID: mdl-19257244

ABSTRACT

We report a chemically driven membrane shape instability that triggers the ejection of a tubule growing exponentially toward a chemical source. The instability is initiated by a dilation of the exposed monolayer, which is coupled to the membrane spontaneous curvature and slowed down by intermonolayer friction. Our experiments are performed by local delivery of a basic pH solution to a giant vesicle. Quantitative fits of the data give an intermonolayer friction coefficient b approximately 2x10;{9} J s/m;{4}. The exponential growth of the tubule may be explained by a Marangoni stress yielding a pulling force proportional to its length.


Subject(s)
Lipid Bilayers/chemistry , Lipids/chemistry , Models, Chemical , Unilamellar Liposomes/chemistry , Cell Membrane/chemistry , Hydrogen-Ion Concentration , Thermodynamics
15.
Akush Ginekol (Sofiia) ; 47(5): 3-6, 2008.
Article in Bulgarian | MEDLINE | ID: mdl-19230256

ABSTRACT

In high risk IVF patients the ovulation triggering was done with agonist (0.2 mg), 1.gr., Pregnyl 5000 IE, 2. and 4.gr., Ovitrelle 0.250 mg, 3.gr., and Pregnyl 10000 IE in the fifth--non-risk group. The protocol of the first and fourth group included antagonist, the second and third group was with short and the fifth group with long agonist protocol. There was no grave OHSS in the first group, one case in each second, third and fourth group and 4 cases in the fifth group, as a whole 7 patients (3.3%). In all of them an abdominal drainage lasting 4 to 30 days was performed and all pregnancies were preserved. The average success rate was 50%, 71.4% in the fourth and 43.1% in the fifth group. A protocol with antagonist and ovulation triggering with agonist or reduced dose ChG in order to diminish OHSS in high risk IVF patients is recommended.


Subject(s)
Chorionic Gonadotropin , Fertilization in Vitro/methods , Gonadotropin-Releasing Hormone/agonists , Ovulation Induction/methods , Adult , Chorionic Gonadotropin/administration & dosage , Chorionic Gonadotropin/therapeutic use , Chorionic Gonadotropin/urine , Drug Administration Schedule , Drug Therapy, Combination , Female , Glycoprotein Hormones, alpha Subunit/administration & dosage , Glycoprotein Hormones, alpha Subunit/therapeutic use , Glycoprotein Hormones, alpha Subunit/urine , Gonadotropin-Releasing Hormone/administration & dosage , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/antagonists & inhibitors , Gonadotropin-Releasing Hormone/therapeutic use , Humans , Ovarian Hyperstimulation Syndrome/prevention & control , Recombinant Proteins/administration & dosage , Recombinant Proteins/therapeutic use , Recombinant Proteins/urine , Treatment Outcome
16.
Akush Ginekol (Sofiia) ; 47(5): 34-7, 2008.
Article in Bulgarian | MEDLINE | ID: mdl-19230260

ABSTRACT

Bleedings are the leading cause for mother's mortality rate worldwide and that is why the authors face once more the abdominal operative methods for definite copying the early post partum haemorrhages (EPH). They share their experience gained already with 46 cases when EPH has definitively been copied by means of stepwise uterine devascularization of the vessels with atonic bleedings and ligation of a. iliaca interna presenting with laceration of the lower uterine segment and vagina as well. Hysterectomy has been performed only when the uterus has already exhausted its fertile capacities in a structural and functional aspect, e.g. after numerous abortions, deliveries and experienced Caesarean sections, intra-partum septic conditions, appoplexio uteri, etc. According to authors' opinion, the stepwise uterine devascularization is the method of choice for EPH surgical copying during which woman' fertility is, in fact, preserved. With this method, no complications typical of the various compression methods applied to overcome the puerperal bleedings such as B-Linch sutures, haemostatic sutures of 'multiple squares' type as well as U-shape compression sutures have been observed at all.


Subject(s)
Arteries/surgery , Hemostatic Techniques , Postpartum Hemorrhage/surgery , Uterus/blood supply , Female , Humans , Hysterectomy , Laparoscopy , Ligation , Postpartum Hemorrhage/epidemiology , Pregnancy , Prospective Studies , Suture Techniques , Uterus/surgery
17.
Phys Rev Lett ; 99(4): 044503, 2007 Jul 27.
Article in English | MEDLINE | ID: mdl-17678371

ABSTRACT

We examine the time-dependent distortion of a nearly circular viscous domain in an infinite viscous sheet when suction occurs. Suction, the driving force of the instability, can occur everywhere in the two phases separated by an interface. The model assumes a two-dimensional Stokes flow; the selection of the wavelength at short times is determined by a variational procedure. Contrary to the viscous fingering instability, undulations of the boundary may be observed for enough pumping, whatever the sign of the viscosity contrast between the two fluids involved. We apply our model to the suction by lipoproteins of cholesterol-enriched domains in giant unilamellar vesicles. Comparison of the number of undulations given by the model and by the experiments gives reasonable values of physical quantities such as the viscosities of the domains.

19.
Am J Hum Biol ; 18(6): 798-805, 2006.
Article in English | MEDLINE | ID: mdl-17039479

ABSTRACT

The effect of cobalt on the cardiovascular system is one of many aspects of cobalt metabolism in humans. Elastin and collagen are the main proteins of the vascular wall. The aims of this study were: 1) to determine serum cobalt concentrations in children with hypertension; and 2) to study the correlation between serum cobalt and some biological markers of the extracellular matrix of the vascular wall, i.e., anti-elastin and anti-collagen type IV antibodies. Patients showed statistically significant higher levels of systolic and diastolic blood pressure, and significantly lower serum cobalt concentrations, than controls. Children with hypertension showed significantly higher levels of total cholesterol (P = 0.0003) and collagen type IV IgM (P = 0.04). Collagen type IV IgG levels (P = 0.027) were lower than in controls. Serum cobalt in patients showed a correlation with systolic blood pressure (r = -0.44, P = 0.05), elastin IgM (r = 0.60, P = 0.007), and collagen type IV IgG (r = -0.46, P = 0.04). Our data suggest the existence of a correlation between changes in levels of serum cobalt, total cholesterol, anti-collagen type IV antibodies, and essential hypertension in children. This is the first study of serum cobalt in children with essential hypertension.


Subject(s)
Cobalt/blood , Collagen/metabolism , Elastin/metabolism , Extracellular Matrix/metabolism , Hypertension/physiopathology , Adolescent , Analysis of Variance , Autoantibodies/metabolism , Biomarkers , Blood Vessels/metabolism , Blood Vessels/ultrastructure , Bulgaria , Case-Control Studies , Child , Cholesterol/blood , Collagen/immunology , Collagen Type IV/immunology , Elastin/immunology , Humans
20.
Akush Ginekol (Sofiia) ; 45 Suppl 3: 60-4, 2006.
Article in Bulgarian | MEDLINE | ID: mdl-18240726

ABSTRACT

PURPOSE OF THE STUDY: To investigate the reasons for preterm premature rupture of amnionic membranes (PPRAM), the methods for diagnosis and for identification of the syndrome of amnionic infection as well as to define the behaviour in relation to gestational age. MATERIAL AND METHODS: The study covered 859 premature newborns of which, 283 (32.95%) were delivered by mothers presenting with PPRAM. The following methods were made use of: inspection by using speculum, "fern test", pH with nitrazine paper, and ultrasound examination. The amnionic infection was proved by means of measurement of body temperature and heart rate, leukocyte number and differential blood test, C-reactive protein, microbiological examination of the amniotic fluid including the diagnostic polymerase chain reaction as well as by histological examination of the amnionic membranes. RESULTS AND DISCUSSION: The most common reasons for PPRAM were the following: histologically proved chorioamnionitis (in 15.55%), bleeding during the present pregnancy (in 14.84%), preceding PPRAM or preterm delivery (in 10.95%), multifoetus pregnancy (in 4.59%), isthmicocervical insufficiency (in 3.89% of the cases), etc. No dependence between the histological evidence of a chorioamnionitis and the time passed since PPRAM and between the bacterial contamination of the amniotic fluid and the presence of amnionitis could be established at all. In the protocol, the rules for the application of corticosteroids, antibiotics and tocolytics in dependence on the gestational age and the obstetric behaviour such as expecting, labour induction, or Cesarean section were defined.


Subject(s)
Chorioamnionitis , Fetal Membranes, Premature Rupture , Adrenal Cortex Hormones/administration & dosage , Adrenal Cortex Hormones/therapeutic use , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Chorioamnionitis/diagnosis , Chorioamnionitis/drug therapy , Female , Fetal Membranes, Premature Rupture/diagnosis , Fetal Membranes, Premature Rupture/drug therapy , Fetal Membranes, Premature Rupture/etiology , Gestational Age , Humans , Infant, Newborn , Pregnancy , Risk Factors , Tocolytic Agents/administration & dosage , Tocolytic Agents/therapeutic use
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