34 research outputs found
Stability analysis of a hypothalamic-pituitary-adrenal axis model with inclusion of glucocorticoid receptor and memory
This paper analyzes a four-dimensional model of the
hypothalamic-pituitary-adrenal (HPA) axis that includes the influence of the
glucocorticoid receptor in the pituitary. Due to the spatial separation between
the hypothalamus, pituitary and adrenal glands, distributed time delays are
introduced in the mathematical model. The existence of the positive equilibrium
point is proved and a local stability and bifurcation analysis is provided,
considering several types of delay kernels. The fractional-order model with
discrete time delays is also taken into account. Numerical simulations are
provided to illustrate the effectiveness of the theoretical findings.Comment: 9 page
First trimester combined screening for fetal aneuploidies enhanced with additional ultrasound markers: an 8-year prospective study
Objectives: To describe our screening population and audit of the performance of first-trimester screening for Down syndrome, based on a combined test, enhanced with additional ultrasound markers, over the whole period of the study.
Material and methods: We performed a prospective study from 2009 to 2016, which included 1358 singleton fetuses with a crown-rump length of 45–84 mm. The risk of aneuploidy was calculated using nuchal translucency, fetal heart rate (FHR), and additional markers, such as nasal bone (NB), tricuspid flow (TF) and ductus venosus (DV), combined with maternal serum free β-human chorionic gonadotropin (fβ-hCG) and pregnancy-associated plasma protein-A (PAPP-A).
Results: 87% of patients were evaluated using all the additional ultrasound markers and 97% of patients were assessed using at least two markers, in any combination. 70.5% of patients were also evaluated using maternal serum biochemistry. The most common risk calculation used nuchal translucency, FHR, all additional ultrasound markers, fβ-hCG and PAPP-A in 851 (62.7%) of cases. The adjusted risk of trisomy 21 was greater than 1:100 in 65 (4.8%) women. Of these patients, 58 (87.7%) chose to have an invasive test. There were 24 aneuploid fetuses (1.7%); and from these we identified 12 (50%) trisomy 21, 6 (25%) sex chromosome anomalies, with the remainder being triploidy and trisomy 18/13. The combined test detected 11 of the 12 cases as having trisomy 21, with a first trimester detection rate of 91.7%. 39 fetuses (2.8%) had various types of structural anomalies. Conclusions: The combined test enhanced with all additional ultrasound markers did not show any substantial improvement in T21 detection rate, when compared with using only one of the additional markers
Elastographie en temps réel – impact de la réponse d’anélasticité
Université de Médecine et de Pharmacie ”Victor Babes”, Timisoara, Roumanie
The IVth Congress of Radiology and Medical Imaging of the Republic of Moldova with international participation, Chisinau, May 31 – June 2, 2018Introduction: L’élastographie mammaire est une technique récente utilisée en complément de l’échographie mammaire dans le dépistage du
cancer du sein. L’élastographie fournit non seulement des informations qualitatives (carte à codage de couleur), ainsi que quantitative, liée
au rapport d’élasticité du nodule versus le tissu adipeux (FLR). À la lumière de la qualité, il y a controverse sur la valeur de discrimination
entre les lésions bénignes et malignes. Actuellement, la limite utilisée dans notre centre est la valeur médiane de 4,88, validée sur une étude
comparative avec l’examen histopathologique, une valeur qui assure une sensibilité de 86,5% et une spécificité de 90,4%
Matériel et méthodes: L’étude a inclu 344 femmes, âgées de 19 à 76 ans, avec des pathologies mammaires chirurgicales, qui ont eu un résultat
histopathologique clair et, dans certains cas, un résultat immunohistochimique clair.
Résultats: Sur le total de 344 cas, ont été diagnostiqués lésions bénignes en 186 (54,1%), le cancer du sein dans 158 cas (45,9%). Lorsque
nous avons examiné la valeur FLR, on a eu la stratification du risque suivant: faible risque dans 166 cas, 38 cas avec risque intermédiaire
et à haut risque 138 cas. La sensibilité et la spécificité de cette stratification considérée isolée, sans l’information fournie par l’échographie
2B, est 92,4% et respectivement 83,9%. Le système conventionnel BIRADS-US n’avait qu’une sensibilité de 75,6%, avec une spécificité de
69,9%. Contrairement à cela, un nombre important de cas classés comme intermédiaires, 97 cas (catégorie BIRADS 4 a), ont été réorganisés
dans l’autre catégorie de risque, alors quand ils ont été soumis à l’évaluation élastographique, 23 ont été attribués à un groupe à haut risque
en raison de l’anélasticité et 26 ont été attribués à classe de risque faible parce que l’élasticité était présente. Seuls 48 cas sont restés dans la
catégorie intermédiaire.
Conclusions: Évidemment, l’élastographie apporte un plus pour l’échographie classique, en réduisant le nombre de résultats faux positifs et
faux négatifs par rapport à l’échographie classique
Changes in T Cell and Dendritic Cell Phenotype from Mid to Late Pregnancy Are Indicative of a Shift from Immune Tolerance to Immune Activation.
During pregnancy, the mother allows the immunologically distinct fetoplacental unit to develop and grow. Opinions are divided as to whether this represents a state of fetal-specific tolerance or of a generalized suppression of the maternal immune system. We hypothesized that antigen-specific T cell responses are modulated by an inhibitory T cell phenotype and modified dendritic cell (DC) phenotype in a gestation-dependent manner. We analyzed changes in surface markers of peripheral blood T cells, ex vivo antigen-specific T cell responses, indoleamine 2,3-dioxygenase (IDO) activity (kynurenine/tryptophan ratio, KTR), plasma neopterin concentration, and the in vitro expression of progesterone-induced blocking factor (PIBF) in response to peripheral blood mononuclear cell culture with progesterone. We found that mid gestation is characterized by reduced antigen-specific T cell responses associated with (1) predominance of effector memory over other T cell subsets; (2) upregulation of inhibitory markers (programmed death ligand 1); (3) heightened response to progesterone (PIBF); and (4) reduced proportions of myeloid DC and concurrent IDO activity (KTR). Conversely, antigen-specific T cell responses normalized in late pregnancy and were associated with increased markers of T cell activation (CD38, neopterin). However, these changes occur with a simultaneous upregulation of immune suppressive mechanisms including apoptosis (CD95), coinhibition (TIM-3), and immune regulation (IL-10) through the course of pregnancy. Together, our data suggest that immune tolerance dominates in the second trimester and that it is gradually reversed in the third trimester in association with immune activation as the end of pregnancy approaches
Advanced Ultrasound Application – Impact on Presurgical Risk Stratification of the Thyroid Nodules
Dana Stoian, 1, 2 Viviana Ivan, 1 Ioan Sporea, 1 Varcus Florian, 3 Ioana Mozos, 4 Dan Navolan, 5 Dragos Nemescu 6 1 2nd Department of Internal Medicine, “Victor Babes” University of Medicine, Timisoara, Romania; 2Dr. D Center for Ultrasound in Endocrinology, Timisoara, Romania; 3 2nd Department of Surgery, “Victor Babes” University of Medicine, Timisoara, Romania; 4Department of Physiopathology, “Victor Babes” University of Medicine, Timisoara, Romania; 5Department of Obstetrics Gynecology, “Victor Babes” University of Medicine, Timisoara, Romania; 6Department of Obstetrics Gynecology, “Gr. T. Popa” University of Medicine, Iasi, RomaniaCorrespondence: Dan NavolanDepartment of Obstetrics Gynecology, “Victor Babes” University of Medicine and Pharmacy Timisoara, P-ta Eftimie Murgu, Nr. 2, Timisoara 300011, RomaniaEmail [email protected] Ivan 2nd Department of Internal Medicine, “Victor Babes” University of Medicine and Pharmacy Timisoara, P-ta Eftimie Murgu, Nr. 2, Timisoara 300011, RomaniaTel +40 722 960 911Fax +40 256 020 1890Email [email protected]: Current major guidelines recommend risk stratification of the thyroid nodules, after each diagnostic evaluation, in order to focus attention on potentially risky nodules. The main aim of our study was to evaluate the performance of combined advanced ultrasound techniques in this process, compared with conventional stratification models, in order to reduce unnecessary fine-needle biopsies, respectively, surgery.Material and Methods: We evaluated 261 cases (261 nodules) using conventional ultrasound (2B), real-time Doppler evaluation (4D) respectively, real-time elastography, using a linear multifrequency probe and a linear volumetric probe (Hitachi Prerius Machine, Hitachi Inc, Japan). All the nodules were classified using a risk stratification model comprising seven conventional US characteristics, two 4 D characteristics and a color map RTE aspect. The results were compared with the pathology results, considered the golden standard diagnosis.Results: The prevalence of malignant nodules was 21.83% (57 cases). Conventional risk classification generated: 106 low-risk cases, 113 intermediate-risk and 42 high-risk cases. Our proposed risk classification changes the conventional risk classification with a risk upgrade in 27 cases and with a risk downgrade in 69 cases. The diagnostic quality of the combined risk stratification model was better, considering a low-risk category predictive for benignancy and a high category predictive for malignancy: Sensitivity: 80.88% versus 49.01%, respectively, Specificity: 91.22% versus 54.38. The diagnostic power differences were observed regardless of the nodule size.Conclusion: Advanced ultrasound techniques did add diagnostic value in the presurgical risk assessment of the thyroid nodules.Keywords: strain elastography, volumetric Doppler, complex ultrasound thyroid evaluation, risk stratificatio
A Computational Intelligence Approach for Ranking Risk Factors in Preterm Birth
Abstract- The aim of this paper is to propose a filter, based on a multi-objective evolutionary algorithm, for attributes ’ ranking in the context of a data mining task. The behavior of this filter is analyzed for the problem of ranking risk factors in preterm birth. The results obtained by applying the proposed evolutionary approach are compared with rankings obtained by applying some classical attributes selection methods and a logistic regression procedure. The influence of the ranking on a supervised classification (based on a radial basis function neural network) is also analyzed and the results suggest that the evolutionary approach provides a good quality ranking. I
Safety Indices during Fetal Echocardiography at the Time of First-Trimester Scan Are Machine Dependent.
The aim of our study was to evaluate the thermal index (TI) and mechanical index (MI), during the assessment of the fetal heart at the time of first-trimester scan, with different ultrasound machines. This was part of an observational study conducted in patients undergoing routine first-trimester screening. Cases were examined with Voluson E8 or 730Pro scanners using 2-8 MHz transabdominal probes. TI and MI were retrieved from the saved displays while in gray mode, color flow mapping and pulsed-wave (PW) Doppler examinations of the fetal heart and also from the ductus venosus (DV) assessment. We evaluated 552 fetal cardiac examinations, 303 (55%) performed with Voluson E8 and 249 (45%) with Voluson 730Pro ultrasound machines. The gray-scale exam of the heart and the PW Doppler DV assessment had TI values significantly lower for the Voluson E8 group (median, 0.04 vs. 0.2 and 0.1 vs. 0.2, respectively). The MI values from gray-scale and color flow mapping of the heart were significantly lower (median, 0.6 vs, 1.2 and 0.7 vs. 1) and for PW Doppler exam of the tricuspid flow were significantly higher (median 0.4 vs. 0.2) in the Voluson E8 group. The TI values from Doppler examinations of the heart, either color flow or PW imaging and MI values from DV assessment were not significantly different between the two groups. A different (newer) generation of ultrasound equipment provides lower or at least the same safety indices for most of the first-trimester heart examinations
A rare case of partial trisomy 8q24.12-q24.3 and partial monosomy of 8q24.3: Prenatal diagnosis and clinical findings
Objective: We describe a rare case of “pure” 8q duplication diagnosed prenatally by conventional karyotyping, that was further characterized by array comparative genomic hybridization (aCGH). Case report: A 39-year-old, primigravida woman underwent amniocentesis at 23 weeks of gestation because of an abnormal second trimester maternal serum screening for Down syndrome. Conventional cytogenetic analysis demonstrated a karyotype of 46,XX,der(8) (q24.12q24.3) and aCGH identified a duplication of approximately 27 Mb, affecting the distal region of chromosome 8q24.12-q24.3. Parenteral karyotype of both parents was normal and excluded familial translocation or other rearrangements. Although prenatal ultrasound examination showed multiple anomalies the parents decided to keep the pregnancy. The baby was born at 38 weeks of gestation, with an Apgar score of 2. The evolution was unfavorable, and he died within the first 24 h of birth. Conclusion: Molecular investigations contribute to a more accurate characterization of the patients with these rare duplication, but also for estimating their prognosis. Keywords: Array comparative genomic hybridization, Chromosome 8 duplication, Prenatal diagnosi
Thyroid Autoimmune Disease—Impact on Sexual Function in Young Women
The important prevalence of autoimmune thyroid disease (AITD) in the general population was the main motivation for conducting the present study. The present paper aims to estimate the possible comorbidities related to female sexual dysfunction (FSD) and depression related to AITD. The study group consisted of 320 patients: 250 cases known with untreated AITD, divided into subgroups (euthyroid subgroup, subclinical hypothyroidism subgroup and clinical hypothyroidism subgroup); respectively 70 healthy females in the control group. Patients underwent thyroid evaluation, ovarian evaluation and laboratory assays. At the time of the diagnosis of autoimmune thyroid disease, psychometric scales were filled in by the patients: the Female Sexual Function Index 6 (FSFI-6) and the Beck’s Depression Inventory-II (BDI-II). It was observed that healthy patients had significantly higher FSFI scores than patients with AITD (28 vs. 27; p = 0.006). In the AITD group, the risk of FSD increases with the severity of thyroid disease. The most affected areas were: sexual desire (p p = 0.001) and orgasm (p = 0.008), followed by excitability and sexual satisfaction. The severity of hypothyroidism influences the degree of decrease in libido, central and peripheral excitability. Sexual satisfaction and orgasm were less influenced. The field related to pain seems uninfluenced by the presence of thyroid disease. The concomitant presence of depression and the value of thyroid-stimulating hormone (TSH) are risk factors in the development of FSD. Higher TSH value and BDI-II score increase the risk of female sexual dysfunction by 1.083 and 1.295 times, respectively. Our findings are significant and promising; they may help professionals dealing with sexual and reproductive health. Despite the importance of female sexual dysfunction and its prevalence, clinicians and patients often ignore it. In fact, only a small percentage of patients consult their doctors about sexual health, and their doctors do not often ask them questions related to this aspect
Shear Wave Elastography versus Strain Elastography in Diagnosing Parathyroid Adenomas
Objectives. The aim of the study was to compare elastographic means in parathyroid adenomas, using shear wave elastography and strain elastography. Methods. This prospective study examined 20 consecutive patients diagnosed with primary hyperparathyroidism and parathyroid adenoma, confirmed by biochemical assay, technetium-99 sestamibi scintigraphy, and pathology report, after parathyroid surgery. All patients were examined on conventional 2B ultrasound, 2D shear wave elastography, and strain elastography. We determined using 2D shear wave elastography (SWE) the elasticity index (EI) in parathyroid adenoma, thyroid parenchyma, and surrounding muscle and examined using strain elastography the parathyroid adenoma, and determined the strain ratio with the thyroid tissue and muscle tissue. Results. All patients had positive sestamibi scintigraphy and underwent surgery, with confirmation of parathyroid adenoma in all cases. The mean parathormone (PTH) value before surgery was 153.29 pg/ml (36.5, 464.8) and serum calcium concentration was 10.5 mg/dl (9, 11.5). We compared using 2D-SWE and strain elastography parathyroid adenoma with thyroid tissue and with surrounding muscle. The mean EI measured by SWE in parathyroid adenoma was 4.74 ± 2.74 kPa and in thyroid parenchyma was 11.718 ± 4.206 kPa (mean difference = 6.978 kPa, p<0.001), and the mean EI value in muscle tissue was 16.362 ± 3.829 kPa (mean difference = 11.622, p<0.001). Using ROC analysis, we found that an EI below 7 kPa correctly identifies parathyroid tissue. We evaluated parathyroid adenomas using strain elastography by color mapping and strain ratio as a semiquantitative measurement; however, we could not find any statistical correlation comparing the strain ratio obtained from the parathyroid adenoma with the thyroid tissue (p=0.485). Conclusion. Ultrasound elastography is a helpful tool in identifying parathyroid adenomas. A cutoff value below 7 kPa can be used in 2D-SWE. Color maps in strain elastography without adding strain ratio can be used, parathyroid adenoma being identified as score 1 in the Rago criteria