47 research outputs found

    Structural Analysis of the Female Reptile Reproductive System by Micro-Computed Tomography and Optical Coherence Tomography†

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    Volumetric data provide unprecedented structural insight to the reproductive tract and add vital anatomical context to the relationships between organs. The morphology of the female reproductive tract in non-avian reptiles varies between species, corresponding to a broad range of reproductive modes and providing valuable insight to comparative investigations of reproductive anatomy. However, reproductive studies in reptilian models, such as the brown anole studied here, have historically relied on histological methods to understand the anatomy. While these methods are highly effective for characterizing the cell types present in each organ, histological methods lose the 3D relationships between images and leave the architecture of the organ system poorly understood. We present the first comprehensive volumetric analyses of the female brown anole reproductive tract using two non-invasive, non-destructive imaging modalities: micro-computed tomography (microCT) and optical coherence tomography (OCT). Both are specialized imaging technologies that facilitate high-throughput imaging and preserve three-dimensional information. This study represents the first time that microCT has been used to study all reproductive organs in this species and the very first time that OCT has been applied to this species. We show how the non-destructive volumetric imaging provided by each modality reveals anatomical context including orientation and relationships between reproductive organs of the anole lizard. In addition to broad patterns of morphology, both imaging modalities provide the high resolution necessary to capture details and key anatomical features of each organ. We demonstrate that classic histological features can be appreciated within whole-organ architecture in volumetric imaging using microCT and OCT, providing the complementary information necessary to understand the relationships between tissues and organs in the reproductive system. This side-by-side imaging analysis using microCT and OCT allows us to evaluate the specific advantages and limitations of these two methods for the female reptile reproductive system

    Assessment of the effect of 21-day head-down bed rest on the cardiovascular system by blood protein composition

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    Head-down bed rest (HDBR) is one of the models of the physiological effects of weightlessness used, among other things, to assess the effect of hypokinesia on the physiological systems of the human body and, first of all, on the cardiovascular system. The aim of the work was to study the effect of 21 days of HDBR factors on the cardiovascular system based on blood proteomic profile data. It was revealed that HDBR conditions led to an increase in the levels of proteins of the complement and the coagulation cascade systems, platelet degranulation, fibrinolysis, acute phase proteins, post-translational modification of proteins, retinol-binding protein 4 (RBP4), apolipoprotein B, which are associated with cardiovascular diseases, and other proteins that affect the functions of endothelial cells. Blood levels of proteins involved in cytoskeletal remodelling, oxygen transport, heme catabolism, etc. have been shown to decrease during HDBR

    Сhronic kidney disease complications in patients with type 1 diabetes mellitus after simultaneous pancreas-kidney transplantation – potential role of oxidative stress and glycation end products

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    BACKGROUND: Normoglycaemia in patients with diabetes mellitus type 1 (T1DM) after simultaneous pancreas-kidney transplantation (SPKT) is very interesting in regards to chronic kidney disease (CKD) complications dynamics depending of posttransplantation period and possible targets of potential treatment from the point of view “metabolic memory” AIM: To evaluate the relationship between oxidative stress indicators and advanced glycation end products and complications of end-stage renal disease (ESRD) in patients with T1DM Đ°nd a long-term history of diabetes decompensation, who reached stable euglycemia after SPKT. MATERIALS AND METHODS: The study included 20 patients with compensation of carbohydrate metabolism after SPKT performed from November 2011 to September 2018. Assessment included examination of complications of ESRD (arterial hypertension, dyslipidemia, anemia, mineral and bone disorder) and analysis of "metabolic memory" markers: 3-nitrothyrosine (3-NT), superoxide dismutase (SOD), advanced glycation end products (AGE) and AGE receptor (RAGE). We performed follow-up examination of patients included in the early postoperative period (1st day/week) in 6-12 months after SPKT. RESULTS: All patients with DM1 duration for 22 [19; 28] years, diabetic nephropathy (DN) 8 [6; 14] years and duration of renal replacement therapy (dialysis) for 3 [1.5; 4] years reached euglycemia (HbA1c 5,5 [5,1; 5,8] %; ĐĄ-peptide 3,2 [2,45; 3,63] ng/ml) after 6 month of surgical treatment. Despite of stable graft function (estimated glomerular filtration rate (eGFR) CKD-EPI 84 [69; 95] ml/min/1.73m2) 35% of patients still needed antihypertensive therapy, 40% needed treatment with recombinant human erythropoietin (RHuEPO) and 15% – ferrotherapy. With vitamin D deficiency, observed in 80% of cases (13.3 [9.3; 18.5] ng/ml), 55% of patients had secondary hyperparathyroidism, 45% – osteoporosis. The results of the correlation analysis revealed the association of the state of ESRD target organs with the studied "metabolic memory" markers: oxidative stress and AGE-RAGE system. CONCLUSIONS: SPKT as the way to achieve compensation of carbohydrate metabolism and uremia does not provide regress of diabetes and complications of ESRD. Analysis of "metabolic memory" markers indicate their direct contribution to the persistence of metabolic consequences of diabetic nephropathy (DN). Found trends need more long-lasting observation and enlargement of study groups

    Fibulin-2 Is a Driver of Malignant Progression in Lung Adenocarcinoma

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    The extracellular matrix of epithelial tumors undergoes structural remodeling during periods of uncontrolled growth, creating regional heterogeneity and torsional stress. How matrix integrity is maintained in the face of dynamic biophysical forces is largely undefined. Here we investigated the role of fibulin-2, a matrix glycoprotein that functions biomechanically as an inter-molecular clasp and thereby facilitates supra-molecular assembly. Fibulin-2 was abundant in the extracellular matrix of human lung adenocarcinomas and was highly expressed in tumor cell lines derived from mice that develop metastatic lung adenocarcinoma from co-expression of mutant K-ras and p53. Loss-offunction experiments in tumor cells revealed that fibulin-2 was required for tumor cells to grow and metastasize in syngeneic mice, a surprising finding given that other intra-tumoral cell types are known to secrete fibulin-2. However, tumor cells grew and metastasized equally well in Fbln2-null and -wildtype littermates, implying that malignant progression was dependent specifically upon tumor cellderived fibulin-2, which could not be offset by other cellular sources of fibulin-2. Fibulin-2 deficiency impaired the ability of tumor cells to migrate and invade in Boyden chambers, to create a stiff extracellular matrix in mice, to cross-link secreted collagen, and to adhere to collagen. We conclude that fibulin-2 is a driver of malignant progression in lung adenocarcinoma and plays an unexpected role in collagen cross-linking and tumor cell adherence to collagen

    Contribution of Social Isolation, Restraint, and Hindlimb Unloading to Changes in Hemodynamic Parameters and Motion Activity in Rats

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    The most accepted animal model for simulation of the physiological and morphological consequences of microgravity on the cardiovascular system is one of head-down hindlimb unloading. Experimental conditions surrounding this model include not only head-down tilting of rats, but also social and restraint stresses that have their own influences on cardiovascular system function. Here, we studied levels of spontaneous locomotor activity, blood pressure, and heart rate during 14 days under the following experimental conditions: cage control, social isolation in standard rat housing, social isolation in special cages for hindlimb unloading, horizontal attachment (restraint), and head-down hindlimb unloading. General activity and hemodynamic parameters were continuously monitored in conscious rats by telemetry. Heart rate and blood pressure were both evaluated during treadmill running to reveal cardiovascular deconditioning development as a result of unloading. The main findings of our work are that: social isolation and restraint induced persistent physical inactivity, while unloading in rats resulted in initial inactivity followed by normalization and increased locomotion after one week. Moreover, 14 days of hindlimb unloading showed significant elevation of blood pressure and slight elevation of heart rate. Hemodynamic changes in isolated and restrained rats largely reproduced the trends observed during unloading. Finally, we detected no augmentation of tachycardia during moderate exercise in rats after 14 days of unloading. Thus, we concluded that both social isolation and restraint, as an integral part of the model conditions, contribute essentially to cardiovascular reactions during head-down hindlimb unloading, compared to the little changes in the hydrostatic gradient

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Possible role of non-muscle alpha-actinins in muscle cell mechanosensitivity.

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    The main hypothesis suggested that changes in the external mechanical load would lead to different deformations of the submembranous cytoskeleton and, as a result, dissociation of different proteins from its structure (induced by increased/decreased mechanical stress). The study subjects were fibers of the soleus muscle and cardiomyocytes of Wistar rats. Changes in external mechanical conditions were reconstructed by means of antiorthostatic suspension of the animals by their tails for 6, 12, 18, 24 and 72 hours. Transversal stiffness was measured by atomic force microscopy imaging; beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 levels in membranous and cytoplasmic fractions were quantified by Western blot analysis; expression rates of the corresponding genes were studied using RT-PCR.In 6 hours, alpha-actinin 1 and alpha-actinin 4 levels decreased in the membranous fraction of proteins of cardiomyocytes and soleus muscle fibers, respectively, but increased in the cytoplasmic fraction of the abovementioned cells. After 6-12 hours of suspension, the expression rates of beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 were elevated in the soleus muscle fibers, but the alpha-actinin 1 expression rate returned to the reference level in 72 hours. After 18-24 hours, the expression rates of beta-actin and alpha-actinin 4 increased in cardiomyocytes, while the alpha-actinin 1 expression rate decreased in soleus muscle fibers. After 12 hours, the beta- and gamma-actin content dropped in the membranous fraction and increased in the cytoplasmic protein fractions from both cardiomyocytes and soleus muscle fibers. The stiffness of both cell types decreased after the same period of time. Further, during the unloading period the concentration of nonmuscle actin and different isoforms of alpha-actinins increased in the membranous fraction from cardiomyocytes. At the same time, the concentration of the abovementioned proteins decreased in the soleus muscle fibers

    Expression level of genes encoding cytoskeletal proteins in left ventricle cardiomyocytes (LV) and soleus muscle fibers (Sol) of rats after short-term gravitational unloading.

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    <p>*–p<0.05 as compared to the group «Control» – indicated as «C» in this figure, <sup>#</sup>–p<0.05 as compared to the group «24h». A – alpha-actinin-1 gene (Actn1), B – alpha-actinin-4 gene (Actn4), C – beta-actin gene (Actb), D – gamma-actin gene (Actg).</p
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