Sequencing,verification and functional analysis of differentially expressed genes in brain tissue of a rat model with acute intracerebral hemorrhage / 中国组织工程研究

BACKGROUND:There are differentially expressed genes in acute intracerebral hemorrhage,which are related to the occurrence and development of intracerebral hemorrhage. OBJECTIVE:To screen differentially expressed genes and key genes in brain tissue of a rat model with acute intracerebral hemorrhage,to validate them through qPCR,and to analyze the relationships between key genes and the neurological function and brain tissue water content after intracerebral hemorrhage. METHODS:Seventy-eight Sprague-Dawley rats were randomly divided into two groups:in intracerebral hemorrhage group,a rat model of acute intracerebral hemorrhage was made using collagenase injection at the right caudate nucleus;and in sham-operated group,rats were injected with equal amount of saline at the same site.RNA was extracted from rat brain tissues of both groups using the TRIzol method and transcriptome sequencing technology was used to identify differentially expressed genes in brain tissues of acute intracerebral hemorrhage,which were then verified by qPCR and analyzed for the relationships between the genes and neurological function and brain tissue water content after intracerebral hemorrhage.And the key genes were analyzed by GO and KEGG functional enrichment analysis in combination with bioinformatics. RESULTS AND CONCLUSION:Ten key genes were identified,including CXCL8,SERPINE1,TFPI2,CXCR4,GDA,KCNQ5,ERICH3,SCN3B,CACNA1E,and CCL20.The contents of GDA,KCNQ5,ERICH3,SCN3B,and CACNA1E in the intracerebral hemorrhage group were lower than those in the sham-operated group(P＜0.05).The contents of CXCL8,SERPINE1,TFPI2,CXCR4 and CCL20 in the intracerebral hemorrhage group were higher than those in the sham-operated group(P＜0.05).The contents of GDA,KCNQ5,ERICH3,SCN3B,and CACNA1E were positively correlated with brain tissue water content and neurologic deficit score(P＜0.05),while the contents of CXCL8,SERPINE1,TFPI2,CXCR4 and CCL20 were negatively correlated with brain tissue water content and neurologic deficit score(P＜0.05).GO analysis indicated that differentially expressed genes were mainly enriched in two biological processes(leukocyte chemotaxis and chemokine-mediated signaling pathways),two cell components(cation channel complexes and ion channel complexes),and two molecular functions(gated channel activity and ion channel activity).KEGG analysis indicated that differentially expressed genes were concentrated in tumor necrosis factor signaling pathway,glutamatergic synapses and GABAergic synapses.To conclude,the differentially expressed genes in intracerebral hemorrhage include CXCL8,SERPINE1,TFPI2,CXCR4,GDA,KCNQ5,ERICH3,SCN3B,CACNA1E,and CCL20,and these genes are related to brain tissue water content and neurological function after intracerebral hemorrhage.These genes are mainly enriched in cell components,binding functions,cellular protrusions,and other related biological functions.

Hyperspectral imaging for perioperative monitoring of microcirculatory tissue oxygenation and tissue water content in pancreatic surgery - an observational clinical pilot study.

BACKGROUND: Hyperspectral imaging (HSI) could provide extended haemodynamic monitoring of perioperative tissue oxygenation and tissue water content to visualize effects of haemodynamic therapy and surgical trauma. The objective of this study was to assess the capacity of HSI to monitor skin microcirculation and possible relations to perioperative organ dysfunction in patients undergoing pancreatic surgery. METHODS: The hyperspectral imaging TIVITA® Tissue System was used to evaluate superficial tissue oxygenation (StO2), deeper layer tissue oxygenation (near-infrared perfusion index (NPI)), haemoglobin distribution (tissue haemoglobin index (THI)) and tissue water content (tissue water index (TWI)) in 25 patients undergoing pancreatic surgery. HSI parameters were measured before induction of anaesthesia (t1), after induction of anaesthesia (t2), postoperatively before anaesthesia emergence (t3), 6 h after emergence of anaesthesia (t4) and three times daily (08:00, 14:00, 20:00 ± 1 h) at the palm and the fingertips until the second postoperative day (t5-t10). Primary outcome was the correlation of HSI with perioperative organ dysfunction assessed with the perioperative change of SOFA score. RESULTS: Two hundred and fifty HSI measurements were performed in 25 patients. Anaesthetic induction led to a significant increase of tissue oxygenation parameters StO2 and NPI (t1-t2). StO2 and NPI decreased significantly from t2 until the end of surgery (t3). THI of the palm showed a strong correlation with haemoglobin levels preoperatively (t2: r = 0.83, p < 0.001) and 6 h postoperatively (t4: r = 0.71, p = 0.001) but not before anaesthesia emergence (t3: r = 0.35, p = 0.10). TWI of the palm and the fingertip rose significantly between pre- and postoperative measurements (t2-t3). Higher blood loss, syndecan level and duration of surgery were associated with a higher increase of TWI. The perioperative change of HSI parameters (∆t1-t3) did not correlate with the perioperative change of the SOFA score. CONCLUSION: This is the first study using HSI skin measurements to visualize tissue oxygenation and tissue water content in patients undergoing pancreatic surgery. HSI was able to measure short-term changes of tissue oxygenation during anaesthetic induction and pre- to postoperatively. TWI indicated a perioperative increase of tissue water content. Perioperative use of HSI could be a useful extension of haemodynamic monitoring to assess the microcirculatory response during haemodynamic therapy and major surgery. TRIAL REGISTRATION: German Clinical Trial Register, DRKS00017313 on 5 June 2019.

Cardiac Phenotype and Tissue Sodium Content in Adolescents With Defects in the Melanocortin System.

CONTEXT: Pro-opiomelanocortin (POMC) and the melanocortin-4 receptor (MC4R) play a pivotal role in the leptin-melanocortin pathway. Mutations in these genes lead to monogenic types of obesity due to severe hyperphagia. In addition to dietary-induced obesity, a cardiac phenotype without hypertrophy has been identified in MC4R knockout mice. OBJECTIVE: We aimed to characterize cardiac morphology and function as well as tissue Na+ content in humans with mutations in POMC and MC4R genes. METHODS: A cohort of 42 patients (5 patients with bi-allelic POMC mutations, 6 heterozygous MC4R mutation carriers, 19 obese controls without known monogenic cause, and 12 normal weight controls) underwent cardiac magnetic resonance (CMR) imaging and 23Na-MRI. RESULTS: Monogenic obese patients with POMC or MC4R mutation respectively had a significantly lower left ventricular mass/body surface area (BSA) than nonmonogenic obese patients. Left ventricular end-diastolic volume/BSA was significantly lower in POMC- and MC4R-deficient patients than in nonmonogenic obese patients. Subcutaneous fat and skin Na+ content was significantly higher in POMC- and MC4R-deficient patients than in nonmonogenic obese patients. In these compartments, the water content was significantly higher in patients with POMC and MC4R mutation than in control groups. CONCLUSION: Patients with POMC or MC4R mutations carriers had a lack of transition to hypertrophy, significantly lower cardiac muscle mass/BSA, and stored more Na+ within the subcutaneous fat tissue than nonmonogenic obese patients. The results point towards the role of the melanocortin pathway for cardiac function and tissue Na+ storage and the importance of including cardiologic assessments into the diagnostic work-up of these patients.

On the Feasibility of Skin Water Content Imaging Adjuvant to Tissue Oximetry.

Oxygen supply to tissues can be seriously impacted during wound healing. In particular, edema can increase the distance between capillaries, thus decreasing oxygen supply to cells. Thus, the detection of edema, preferably at the preclinical stage, is of great importance. However, there is no reference standard for a cross-sectional, objective measurement of edema. Multispectral imaging can be such adjuvant technology to elucidate the impact of edema on oxygen transport to tissues. The purpose of the current study is to assess the feasibility of multispectral imaging for visualization of water content in surface tissues. METHODS: The skin (hand and forearm) of healthy volunteers was imaged using the Multi-Spectral Imaging Device (MSID). MSID is a multispectral imaging system for visualization of tissue chromophores in surface tissues. It uses a 12-bit scientific-grade NIR-enhanced monochrome camera and ten wavelength light source (600-1000 nm range) to visualize the distribution of oxy- and deoxyhemoglobins, methemoglobin, water, and melanin. The imaging distance is 30 cm and the field of view: 7 × 7 cm. RESULTS: Water content was extracted using various subsets of two and three wavelengths. To mimic the use of a consumer-grade camera, four least significant bits for each pixel value of a 12-bit image were discarded during preprocessing. Eight-bit results were compared with 12-bit results. CONCLUSIONS: Rough numerical calculations and initial experiments show feasibility of water content imaging in the skin using 970 nm band illumination and 12- and 8-bit cameras.

Bedside hyperspectral imaging indicates a microcirculatory sepsis pattern - an observational study.

INTRODUCTION: Microcirculatory alterations are key mechanisms in sepsis pathophysiology leading to tissue hypoxia, edema formation, and organ dysfunction. Hyperspectral imaging (HSI) is an emerging imaging technology that uses tissue-light interactions to evaluate biochemical tissue characteristics including tissue oxygenation, hemoglobin content and water content. Currently, clinical data for HSI technologies in critical ill patients are still limited. METHODS AND ANALYSIS: TIVITA® Tissue System was used to measure Tissue oxygenation (StO2), Tissue Hemoglobin Index (THI), Near Infrared Perfusion Index (NPI) and Tissue Water Index (TWI) in 25 healthy volunteers and 25 septic patients. HSI measurement sites were the palm, the fingertip, and a suprapatellar knee area. Septic patients were evaluated on admission to the ICU (E), 6 h afterwards (E+6) and three times a day (t3-t9) within a total observation period of 72 h. Primary outcome was the correlation of HSI results with daily SOFA-scores. RESULTS: Serial HSI at the three measurement sites in healthy volunteers showed a low mean variance expressing high retest reliability. HSI at E demonstrated significantly lower StO2 and NPI as well as higher TWI at the palm and fingertip in septic patients compared to healthy volunteers. StO2 and TWI showed corresponding results at the suprapatellar knee area. In septic patients, palm and fingertip THI identified survivors (E-t4) and revealed predictivity for 28-day mortality (E). Fingertip StO2 and THI correlated to SOFA-score on day 2. TWI was consistently increased in relation to the TWI range of healthy controls during the observation time. Palm TWI correlated positively with SOFA scores on day 3. DISCUSSION: HSI results in septic patients point to a distinctive microcirculatory pattern indicative of reduced skin oxygenation and perfusion quality combined with increased blood pooling and tissue water content. THI might possess risk-stratification properties and TWI could allow tissue edema evaluation in critically ill patients. CONCLUSION: HSI technologies could open new perspectives in microcirculatory monitoring by visualizing oxygenation and perfusion quality combined with tissue water content in critically ill patients - a prerequisite for future tissue perfusion guided therapy concepts in intensive care medicine.

Postmortem water contents of major organs with regard to the cause of death.

The water contents of individual organs are maintained in a narrow range, but altered in morbidity owing to a disturbance of water equilibrium. The present study investigated the tissue water contents of major organs with regard to the cause of death in serial autopsy cases within 3 days postmortem (n = 329; 223 males, 106 females; age range, 1-100 years). Individual tissue water contents differed markedly across organs, but no significant postmortem or survival-period dependence, gender-related difference, or age dependence was observed. However, the lung water contents were higher in drowning cases, especially in saltwater cases (p < 0.05), and in strangulation among the acute mechanical asphyxiation cases. The brain water contents were higher in hypothermia cases (cold exposure) and tended to be higher in hyperthermia cases (heatstroke). The kidney water contents were higher in drowning and acute cardiac cases than in fatal intoxication and fire fatality cases, but tended to be higher in fresh- and bathwater drowning cases than in saltwater cases (p > 0.05). The spleen water contents were higher in bathwater drowning than in saltwater and freshwater cases, but did not differ among other the causes of death. These findings suggest that the postmortem tissue water content of individual organs, especially the lungs and/or kidney, depends on the cause of death and particularly contributes to differentiation between saltwater and freshwater drowning, respectively. This work therefore provides insight into the investigation of varied tissue water imbalances during the death process. In conclusion, we recommend the measurement of tissue water content because it is easy to perform and appears to be useful for evaluating the pathophysiology of systemic circulatory failure.

Can tissue dielectric constant measurements assess circulating blood volume changes in patients undergoing haemodialysis?

BACKGROUND: The tissue dielectric constant (TDC) method uses an open-ended coaxial probe to achieve non-invasive measurement of water content in skin. The aim of our study was to test the hypothesis that the changes in circulating blood volume would be associated with the changes in TDC values in patients undergoing haemodialysis. METHODS: In this prospective descriptive study, TDC measurements were performed for three parts of the body (the face, shin and hand) before and after patients underwent haemodialysis (N = 83). The primary outcome measure was the correlation between the amount of water removal and ΔTDC at each body site measured (ΔTDC = posthaemodialysis TDC-prehaemodialysis TDC). The secondary outcome measure was the mean difference in TDC value before and after haemodialysis. RESULTS: The TDC values measured at each part of the body were significantly reduced after haemodialysis, but the percentage difference between pre- haemodialysis and posthaemodialysis was small for the face, shin and hand, with %mean ± SE values of -4.4 ± 0.70, -3.2 ± 0.98 and -6.0 ± 1.6; 95 per cent confidence intervals (lower bound to upper bound) of 3.0-5.8, 1.3-5.2 and 2.7-9.2; and P values of P = 0.000, P = 0.000 and P = 0.000, respectively. The inverse correlation between ΔTDC and the amount of water removal was also weak (correlation at the face, r = -0.25, P = 0.028; at the shin, r = -0.26, P = 0.018; and at the hand, no significant correlation). CONCLUSION: Our results indicate that TDC measurement can be used to assess the changes in local oedema, but may be unlikely to evaluate real-time changes in the circulating blood volume in a clinical setting.

Electrical conductivity and permittivity maps of brain tissues derived from water content based on T1 -weighted acquisition.

PURPOSE: To develop an electrical properties tomography (EPT) technique that can provide in vivo electrical conductivity and permittivity images of biological tissue without performing complex-valued radiofrequency field measurements. THEORY AND METHODS: Electrical conductivity and permittivity images are modeled as a monotonic function of tissues' water content (W) under the principle of Maxwell's mixture theory. Water content maps are estimated from two spin-echo images having different repetition times (TRs). For the modeling functions, physically measured parameters (electrical properties, water content, and T1 ) of brain cerebrospinal fluid (CSF), gray matter, and white matter are used as landmark literature references. The formulations are validated by a developed electrolyte-protein phantom and by human brain studies at 3 Tesla (T). RESULTS: The electrical properties (EPs) of the phantom estimated by the proposed method match well with the values measured on the bench. The conductivity and permittivity maps from all experiments show uncompromised spatial resolution without boundary artifacts and higher contrast when compared with water content maps. CONCLUSIONS: Human brain and phantom EP images suggest that water content is a dominating factor in determining the electrical properties of tissues. Despite possible literature inaccuracies, the proposed method offers EP maps that can provide complementary information to current approaches, to facilitate EPT scans in clinical applications. Magn Reson Med 77:1094-1103, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

THz and mm-Wave Sensing of Corneal Tissue Water Content: In Vivo Sensing and Imaging Results.

A pulsed terahertz (THz) imaging system and millimeter-wave reflectometer were used to acquire images and point measurements, respectively, of five rabbit cornea in vivo. These imaging results are the first ever produced of in vivo cornea. A modified version of a standard protocol using a gentle stream of air and a Mylar window was employed to slightly dehydrate healthy cornea. The sensor data and companion central corneal thickness (CCT) measurements were acquired every 10-15 min over the course of two hours using ultrasound pachymmetry.. Statistically significant positive correlations were established between CCT measurements and millimeter wave reflectivity. Local shifts in reflectivity contrast were observed in the THz imagery; however, the THz reflectivity did not display a significant correlation with thickness in the region probed by the 100 GHz and CCT measurements. This is explained in part by a thickness sensitivity at least 10× higher in the mm-wave than the THz systems. Stratified media and effective media modeling suggest that the protocol perturbed the thickness and not the corneal tissue water content (CTWC). To further explore possible etalon effects, an additional rabbit was euthanized and millimeter wave measurements were obtained during death induced edema. These observations represent the first time that the uncoupled sensing of CTWC and CCT have been achieved in vivo.

Effects of hydration on steric and electric charge-induced interstitial volume exclusion--a model.

The presence of collagen and charged macromolecules like glycosaminoglycans (GAGs) in the interstitial space limits the space available for plasma proteins and other macromolecules. This phenomenon, known as interstitial exclusion, is of importance for interstitial fluid volume regulation. Physical/mathematical models are presented for calculating the exclusion of electrically charged and neutral macromolecules that equilibrate in the interstitium under various degrees of hydration. Here, a central hypothesis is that the swelling of highly electrically charged GAGs with increased hydration shields parts of the neutral collagen of the interstitial matrix from interacting with electrically charged macromolecules, such that exclusion of charged macromolecules exhibits change due to steric and charge effects. GAGs are also thought to allow relatively small neutral, but also charged macromolecules neutralized by a very high ionic strength, diffuse into the interior of GAGs, whereas larger macromolecules may not. Thus, in the model, relatively small electrically charged macromolecules, such as human serum albumin, and larger neutral macromolecules such as IgG, will have quite similar total volume exclusion properties in the interstitium. Our results are in agreement with ex vivo and in vivo experiments, and suggest that the charge of GAGs or macromolecular drugs may be targeted to increase the tissue uptake of macromolecular therapeutic agents.

Microvascular fluid exchange during pulsatile cardiopulmonary bypass perfusion with the combined use of a nonpulsatile pump and intra-aortic balloon pump.

OBJECTIVE: To evaluate how pulsed versus nonpulsed cardiopulmonary bypass influences microvascular fluid exchange in an experimental setup combining a nonpulsatile perfusion pump and an intra-aortic balloon pump. METHODS: A total of 16 pigs were randomized to pulsatile cardiopulmonary bypass perfusion with an intra-aortic balloon pump switched to an automatic 80 beats/min mode after the start of cardiopulmonary bypass (pulsatile perfusion [PP] group, n = 8) or to nonpulsatile cardiopulmonary bypass with the pump switched to the off position (nonpulsatile [NP] group, n = 8). Normothermic cardiopulmonary bypass was initiated after 60 minutes of stabilization and continued for 3 hours. The fluid needs, plasma volume, colloid osmotic pressure in plasma, colloid osmotic pressure in interstitial fluid, hematocrit, and total tissue water content were recorded, and the protein masses and fluid extravasation rates were calculated. RESULTS: After cardiopulmonary bypass was started, the mean arterial pressure increased in the PP group and decreased in the NP group. At 180 minutes, the mean arterial pressure of the PP and NP groups was 70.9 ± 2.7 mm Hg and 55.9 ± 2.7 mm Hg, respectively (P = .004). The central venous pressure (right atrium) had decreased in the NP group (P = .002). A decreasing trend was seen in the PP group. No between-group differences were present. The hematocrit and colloid osmotic pressure in plasma and interstitial fluid had decreased similarly in both study groups during cardiopulmonary bypass. The plasma volume of the PP group had decreased initially but then returned gradually to precardiopulmonary bypass levels. In the NP group, the plasma volume remained contracted (P = .02). No significant differences in the fluid extravasation rate were obtained. The fluid extravasation rate of the PP group tended to stay slightly higher than the fluid extravasation rate of the NP group at all measurement intervals. The total tissue water content increased significantly in a number of organs compared with that in the control animals. However, differences in the total tissue water content between pulsed and nonpulsed perfusion were absent. CONCLUSIONS: No significant differences in the fluid extravasation rates were present between pulsed and nonpulsed cardiopulmonary bypass perfusion in the present experimental setup.