In order to observe activity of tumor necrosis factor (TNF) in the serum, pancreatic histopathological damage, as well as their relationships in acute necrotizing pancreatitis (ANP), thirty five SD rats were randomly divided into 7 groups according to their sampling time with 5 in each group. ANP was induced by retrograde infusion of 5% sodium taurocholate through biliopancreatic duct in 6 experimental groups (Group B1～B6).Blood and pancreatic tissue samples were obtained at hour 0,0.5,2,4,6 or 8 respectively when the animals were sacrificed.Results showed that serum level of TNF activity rose significantly in Group B2,and reached the maximal value in Group B4.The pancreatic histopathological damage in ANP rats was getting worse along with time. Serum TNF activity had close relation to pancreatic histopathological score (r=0.63, Ｐ＜0.01),suggesting that serum TNF may play an important role in the process of deterioration of pancreatic tissue damage during ANP.
Objective To investigate the effectiveness and preliminary mechanisms of icariin (ICA) in enhancing the reparative effects of adipose-derived stem cells (ADSCs) on skin radiation damagies in rats. Methods Twelve SPF-grade Sprague Dawley rats [body weight (220±10) g] were subjected to a single dose of 10 Gy X-ray irradiation on a 1.5 cm×1.5 cm area of their dorsal skin, with a dose rate of 200 cGy/min to make skin radiation damage model. After successful modelling, the rats were randomly divided into 4 groups (n=3), and on day 2, the corresponding cells were injected subcutaneously into the irradiated wounds: group A received 0.1 mL of rat ADSCs (1×107cells/mL), group B received 0.1 mL of rat ADSCs (1×107cells/mL)+1 μmol/L ICA (0.1 mL), group C received 0.1 mL of rat ADSCs (1×107cells/mL) pretreated with a hypoxia-inducible factor 2α (HIF-2α) inhibitor+1 μmol/L ICA (0.1 mL), and group D received 0.1 mL of rat ADSCs (1×107cells/mL) pretreated with a Notch1 inhibitor+1 μmol/L ICA (0.1 mL). All treatments were administered as single doses. The skin injury in the irradiated areas of the rats was observed continuously from day 1 to day 7 after modelling. On day 28, the rats were sacrificed, and skin tissues from the irradiated areas were harvested for histological examination (HE staining and Masson staining) to assess the repair status and for quantitative collagen content detection. Immunohistochemical staining was performed to detect CD31 expression, while Western blot and real-time fluorescence quantitative PCR (qRT-PCR) were used to measure the protein and mRNA relative expression levels of vascular endothelial growth factor (VEGF), platelet-derived growth factor BB (PDGF-BB), fibroblast growth factor 2 (FGF-2), interleukin 10 (IL-10), transforming growth factor β (TGF-β), HIF-2α, and Notch1, 2, and 3. ResultsAll groups exhibited skin ulcers and redness after irradiation. On day 3, exudation of tissue fluid was observed in all groups. On day 7, group B showed significantly smaller skin injury areas compared to the other 3 groups. On day 28, histological examination revealed that the epidermis was thickened and the dermal fibers were slightly disordered with occasional inflammatory cell aggregation in group A. In group B, the epidermis appeared more normal, the dermal fibers were more orderly, and there was an increase in new blood vessels without significant inflammatory cell aggregation. In contrast, groups C and D showed significantly increased epidermal thickness, disordered and disrupted dermal fibers. Group B had higher collagen fiber content than the other 3 groups, and group D had lower content than group A, with significant differences (P<0.05). Immunohistochemical staining showed that group B had significantly higher CD31 expression than the other 3 groups, while groups C and D had lower expression than group A, with significant differences (P<0.05). Western blot and qRT-PCR results indicated that group B had significantly higher relative expression levels of VEGF, PDGF-BB, FGF-2, IL-10, TGF-β, HIF-2α, and Notch1, 2, and 3 proteins and mRNAs compared to the other 3 groups (P<0.05). Conclusion ICA may enhance the reparative effects of ADSCs on rat skin radiation damage by promoting angiogenesis and reducing inflammatory responses through the HIF-2α-VEGF-Notch signaling pathway.
Objective To investigate the effects of vaporized perfluorocarbon( PFC) inhalation on histopathology of lung, small intestine, liver and kidney of acute lung-injured rabbits. Methods Eighteen New Zealand rabbits were randomly divided into 3 groups, ie. a conventional mechanical ventilation( CMV)group, a PFC group, and a control group. The rabbits were mechanical ventilated and intratracheally infused artificial seawater to induce acute lung injury. After ALI was established( PaO2 /FiO2 lt; 200 mm Hg) , the CMV group received CMV for 6 hours. The PFC group received PFC inhalation for 2 hours, and followed by CMV for 4 hours. And the control group was weaned from ventilation. Then they were sacrificed for histopathological measurement of lung, small intestine, liver and kidney. Results The rabbits in the control group died in 15 minutes after discontinuation of ventilation. Vaporized PFC inhalation can obviously improve oxygenation and attenuate the damage of the lung in contrast to CMV. Mild improvement was observed in small intestine, liver and kidney after vaporized PFC inhalation, but without statistical significance. Conclusion Vaporized PFC inhalation can improve oxygenation and attenuate lung injury in histopathology,but have no apparent protective effects on extra-pulmonary organs.
Microfluidic chips can be used to realize continuous cryoprotectants (CPA) loading/unloading for oocytes, reducing osmotic damage and chemical toxicity of CPA. In this study, five different Y-shape microfluidic chips were fabricated to realize the continuous CPA loading/unloading. The effects of flow rate, entrance angle, aspect ratio and turning radius of microchannels on the mixing efficiency of microfluidic chips were analyzed quantitatively. The experimental results showed that with the decrease of flow rates, the increase of aspect ratios and the decrease of turning raradius of microchannel, the mixing length decreased and the mixing velocity was promoted, while the entrance angle had little effect on the mixing efficiency. However, the operating conditions and structural parameters of the chips in practical application should be determined based on an overall consideration of CPA loading/unloading time and machining accuracy. These results would provide a reference to the application of microfluidic chip in CPA mixing.
The mumber of Polymorphonuclear leukocyte (PMN) in hepatic tissue increased in the rats with cholangitis, PMN infiltration was mainly in the hepatic sinus in the early stage; and PMN infiltration presented around the hepatocytes 12 hours after infection. Degeneration and necrosis of the hepatic cells was also observed in the rats with acute cholangitis. Only 40 percent of the rats survived 24 hours after infection. Depletion of circulating PMN decreased the damage and necrosis of hepatocytes and improving the survival rate of the infected rats. The results suggest that PMN infiltration plays an important role in hepatic damage in acute cholangitis.
ObjectiveTo explore the method of preventing heat steam induced skin damage in robotic nipple-sparing mastectomy and immediate breast reconstruction (R-NSM-IBR) using Da Vinci Robots. Methods A clinical data of 128 female patients with breast cancer, who were treated with R-NSM-IBR between September 2022 and December 2023 and met the selection criteria, was retrospectively analyzed. During robotic nipple-sparing mastectomy, the breasts were covered with gauze cooled by ice water to reduce skin temperature in 99 cases (group A) and were not treated in 29 cases (group B). There was no significant difference in the age, affected side, body mass index, pathological type of breast cancer, and constituent ratios of adjuvant chemotherapy and neoadjuvant chemotherapy between the two groups (P>0.05). Intraoperative breast skin temperature, unilateral robotic nipple-sparing mastectomy time, and the incidence of complications of breast heat steam induced skin damage were recorded. Results The time for unilateral robotic nipple-sparing mastectomy was (77.18±9.23) minutes in group A and (76.38±12.88) minutes in group B, with significant difference between the two groups (P<0.05). The intraoperative breast skin temperature was significantly lower in group A than in group B [(25.61±0.91)℃ vs (33.38±1.14)℃; P<0.05]. Seven cases of heat steam skin damage occurred during operation, including 2 cases (2.0%) in group A and 5 cases (17.2%) in group B, with a significant difference in incidence between the two groups (P<0.05). Among them, 1 patient in group B had a vesication rupture and infection, which eventually led to the removal of the implant; the rest of the patients were treated with postoperative interventions for skin recovery. Conclusion The use of breast covered with gauze cooled by ice water during R-NSM-IBR can effectively reduce the risk of heat steam induced skin damage.
The deoxyribonucleic acid (DNA) molecule damage simulations with an atom level geometric model use the traversal algorithm that has the disadvantages of quite time-consuming, slow convergence and high-performance computer requirement. Therefore, this work presents a density-based spatial clustering of applications with noise (DBSCAN) clustering algorithm based on the spatial distributions of energy depositions and hydroxyl radicals (·OH). The algorithm with probability and statistics can quickly get the DNA strand break yields and help to study the variation pattern of the clustered DNA damage. Firstly, we simulated the transportation of protons and secondary particles through the nucleus, as well as the ionization and excitation of water molecules by using Geant4-DNA that is the Monte Carlo simulation toolkit for radiobiology, and got the distributions of energy depositions and hydroxyl radicals. Then we used the damage probability functions to get the spatial distribution dataset of DNA damage points in a simplified geometric model. The DBSCAN clustering algorithm based on damage points density was used to determine the single-strand break (SSB) yield and double-strand break (DSB) yield. Finally, we analyzed the DNA strand break yield variation trend with particle linear energy transfer (LET) and summarized the variation pattern of damage clusters. The simulation results show that the new algorithm has a faster simulation speed than the traversal algorithm and a good precision result. The simulation results have consistency when compared to other experiments and simulations. This work achieves more precise information on clustered DNA damage induced by proton radiation at the molecular level with high speed, so that it provides an essential and powerful research method for the study of radiation biological damage mechanism.
Local hypothermia as a preventive method to reperfusion injury of skeletal muscles was studied. Sixteen Japanese rabbits were divided into four groups at random. Before the tourniquet was inflated, a cold gel pack was applied to the right hind leg of each rabbit for 15 minutes to produce local hypothermic condition, without application of tourniquet the left hind limb was under local hypothermic condition as a control. The duration of tourniquet ischemia was 4 hours, and then reperfusion for one and two hours in the A and B groups respectively; in the C and D groups the duration of ischemia was 5 hours, and reperfusion for one and two hours, respectively. The muscle temperature averaged 16.6 degrees C with a needle thermocouple in the hind limb under local hypothermia. The serum K+, LA, SOD, LPO were determined from bilateral femoral veins, and electron and light microscopic studies of sural muscles were done in the post-reperfusion period. It was found that the K+, LA, LPO were lower than that of the control groups (P lt; 0.01), but SOD was higher than that of the control group (P lt; 0.01). Electron and light microscopic studies showed sight but reversible damage of muscular structure with the possibility of in the hypothermic groups cell regeneration. Basing on this experimental results, this method was applied in 45 cases reparative and reconstructive surgery of limbs. The duration of application of tourniquet averaged 2 hours and 57 minutes, the longest being 4 hours and 31 minutes, when the muscle temperature had reduced to 22.4 degrees C. There were no postoperative complications associated with this technique. Local hypothermia appeared to be a safe and effective method of decreasing the reperfusion damage after ischemia.
ObjectiveTo summarize the nursing experience of vacuum-assisted closure (VAC) technology for deficiency of skin and soft tissue in "4·20" earthquake damage. MethodsWe used VAC to treat 20 patients suffering from deficiency of skin and soft tissue who were injured in "4·20" earthquake (35 wounds) from April 21st to 28th, 2013; and we observed closely the results of nursing for pain and psychological care. ResultsA total of 35 wounds were all cleaned after 5 to 7 days; 20 wounds were healed after VAC treatment; 15 wounds recovered well by covering autogenous split-thickness skin; 20 patients had stable emotion and all left the hospital with the recovery. ConclusionVAC for deficiency of skin and soft tissue caused by "4·20" earthquake damage may obviously decrease the time of wound healing, relieve the pain caused by changing fresh dressing, and reduce the length of stay in the hospital.
Energy interruption and infrastructure damage are the common characteristic between the snow disaster occurred in some southern provinces of China and the 5?12 Wenchuan earthquake in China in 2008. This paper summaries the effects on medical and health institutions caused by interruption of energy flow and damaged infrastructure, shares the preparation and response practices, experience, and lessons of medical disasters, and gives suggestions about how to prepare and response for medical and health institutions when energy flow is interrupted and infrastructure is damaged.