【Abstract】Objective To study the change of pancreatic microcirculation in the early phase of acute pancreatitis. MethodsLiteratures on acute pancreatitis and microcirculation were collected and reviewed.ResultsPancreatic microcirculation has changed in the early phase of acute pancreatitis, including contraction of interlobular arteriole, slowing of blood fluid, increasing of pancreatic vascular permeability, leukocyte adherence in postcapillary venules, and decreasing of pancreatic perfusion.Conclusion Impairment of pancreatic microcirculation in the early phase of acute pancreatitis may play a key role in the progression of this disease.
Objective To study the advances in microcirculation after islets of Langerhans transplantation (ILT). Methods The literature in the recent years on the study of the relationship between ILT and microcirculation was reviewed. Results The process of angiogenesis and revascularization of the islet grafts was in progress within 1 week after transplantation, and was completed within 10-14 days after transplantation, exhibiting a microangioarchitecture similar to pancreatic islets in situ. The sequence of vascular intraislet cellular perfusion was from β cells outward to α-and δ-cell cortex, with the majority of α cells perfused before the majority of δ cells. Freely transplanted islet grafts were revascularized from the hostderived microvascular bed. The interstitial pressure in the islet transplants was markedly lower than the capillary pressure. There were clearly differences in microcirculation between syngeneic and xenogeneic islet grafts. The phenomena of microcirculation failure were observed in xenografts. The influential factors of microcirculation after ILT were ①culture temperature of isolated islets, ②cultured time and cryopreserved method of islets, ③blood glucose, ④immunosuppressive agents, ⑤angiogenesis factors. Conclusion Microvascularization of freely islet grafts is one of the essential requirements for successful engraftment, guaranteeing sufficient nutritional blood supply to the tissue and establishing blood drainage for adequate liberation of the endocrine hormones. Through the studies of the microcirculation after ILT, it is helpful to recognize the mechanism of the survival of islet grafts.
The model of acut hemorrhagic necrotizing pancreatitis(AHNP)was produced by retrograde injection of 3% sodium taurocholate into the biliopancreatic duct.48rats with AHNP were treated with Tanshin by subcutaneous injection(100mg/100g body weight,q12h,tanshin group),48 rats with AHNP without any treatment as control(control group).The resule showed that in the control group,there were severe hemorrhage,necroses and the lesions of microvascular,the activity of pancreatic enzyme in serum increased significantly(Plt;0.01)at 6h,after 12h the activities of those pancreatic enzymes decreased gradually, the lesions of microvascular and histology were becoming severer.In the Tanshin group,at 24h the lesions of microvascular and histology of the pancreas were modified significantly (Plt;0.05).These results suggest that the lesion of microcirculation play an important role in the later AHNP,and Tanshin has some effects on the AHNP by modifying the microcirculation of the pancreas.
In order to observe the effect of far infrared rays on the survival of skin flap, the following experiment was performed. Forty-eight SD rats were selected and divided into two groups. The rats received 0.3 w/cm2 radiation twice a day from 3 days before operation to 5 days after operation in the experimental group, while in the control group the rats received none before or after the operation. The flap was designed as 2 cm x 6 cm in the back of the rats with the pedicle caudalward. The microcirculatory changes of the flap were observed, and the survival area of the flap was calculated. The results showed that either in the proximal or in the distal part of the graft, in the experimental group, the mean opening rate, diameter and the flowing velocity of the microvessels were significantly higher than those in the control group (P lt; 0. 05). The mean rate of survival area of the experimental group (80.5%) was also higher than that of the control group (62.7%) (P lt; 0.01). It was suggested that radiation with far infrared rays could dilate the microvessels, improve the flap microcirculation, therefore, enhance the survival of the randomized skin flap.
In order to study the influence of reperfusion following ischemia on microvesseles and microcirculation of skeletal muscle, unilateral hindlimbs of 16 rabbits were subjected to normothermic ischemia for 2 and 5 hours by tourniquet. After release of the tourniquet, microcirculation of the peritenon on dorsum of the foot was observed for 1 hours by intravital microscope. At 1 hour and 72 hours following reperfusion, the anterior tibia muscle biopsiy were taken and the specimens were subjected to light and electron microscopic examinations. It was found that after release of the tourniquet, in the limbs undergone 2 hours ischemia, there was immediate and well distributed reflow in the microvesseles of peritenon though a few aggregates of red cells and increase in the number of adherent leukocytes occured in some venules, and the microvesseles of the skeletal muscle only showed signs of minimal injury, the muscle fibers could survive in the limbs undergone 5 hours of ischemia, however, there was serious disturbance of microcirculation in theperitenon, which was characterized by "no reflow" in most area and there was signi ficant increase in the number of leukocytes adherent to venular endothelium, and the microvesseles of the skeletal muscle showed signs of severe injury, including remarkable swelling of the endothelial cell, disruption of the basement membrane and interstitial edema, and finally, most of the muscle fibers had necrosis occured. The results demonstrated that reperfusion following ischimia might result in microvascular injury and microcirculation disorder in the ischemic area. The degree of the injury and disorder depended on the duration of ischemic period, and was an important factor which determined the fate of the parenchymal cell.
Anti-VEGF therapies have been widely used in the treatment of age-related macular degeneration, diabetic macular edema, retinal vein occlusion with macular edema and other retinal diseases. It have achieved remarkable treatment effect with relatively high safety, but there are still reports of adverse reactions in cardio-cerebral vessels and eyes. There are many methods to measure retinal blood flow. Although the principles of these methods are different, the results are different, and there is no uniform standard, it has been observed that anti-VEGF drugs may cause some changes in retinal vessel diameter, arterial blood flow velocity and blood flow parameters. Especially after multiple injections, the effect may be more obvious.
Objective To observe and analysis the features of images of fundus fluorescein angriography (FFA) in low-perfused retinopathy caused by cephalo-cervical peripheral vascular stenosis or occlusion. Methods The results of FFA of 27 patients diagnosed with carotid artery stenosis or occlusion by digital subtraction angiography (DSA) and examination of Doppler and vascular-pulsation were retrospectively analyzed. Result All of the patients had a delayed arm-retinal circulation duration from 20.0 to 81.08 seconds with the mean of 32.1 seconds; a delayed retinal arteriovenous filling duration from 6 to 64.0 seconds with the mean of 24.2 seconds. Delayed arm-retinal circulation duration and retinal a rteriovenous filling duration in 10 cases (37.0%); microangioma, vascular wall staining, nonperfused capillary area in 11 (40.7%); and anterior ischemic syndrome in 6 (22.2%) were found. In the 6 patients with anterior ischemic syndrome, 4 cases had narrow retinal artery, segmental changes of blood stream, vascular atresia, and abnormal arterio-venous anastomosis, and 2 cases had bold vascular loops. Conclusions The main manifestations of FFA in patients with low-perfused retinopathy are malperfusion and retinal ischemia, whose degrees relate to the extend of carotid artery stenosis or atresia, and the process of the disease.Serious retinal ischemia may combined with anterior ischemic syndrome. (Chin J Ocul Fundus Dis，2004，20：84-86)
ObjectiveTo explore the effects of urinastatin(UTI) on microcirculation of extrapancreatic organs in rats with acute necrotizing pancreatitis(ANP). Methods A total of 48 rats were randomized into control group, ANP group and UTI group. The model of ANP was established by uniform injection of 5% sodium taurocholate solution under pancreatic capsule, only injection of normal saline in control group. Then the rats of UTI group were injected with UTI through the femoral vein, the rats of ANP group and control group were injected with normal saline. The blood flow of lung, kidney and distal small intestine was measured by radioactive biomicrosphere technique at 2 h and 6 h after ANP.ResultsCompared with the control group, the blood flow of lung, kidney and intestine was decreased significantly in the ANP group at the 2 h and 6 h after ANP （P＜0.05）, compared with the ANP group, the blood flow was increased significantly in UTI group （P＜0.05）. ConclusionMicrocirculation disorder is an important factor of the extrapancreatic organ damage in ANP, and UTI plays a protective role against microcirculation disorder of the extrapancreatic organ in ANP.
Objective To investigate the relationship between gene expression of endothelin-3 (ET-3） and inflammation of acute pancreatitis （AP） in rats. Methods Fifty-four rats were divided randomly into 4 groups: sham operation group, AP group, arterial injection group and vein injection group. AP was induced by reverse intra-bile duct infusion 4.5% sodium taurocholate, treated with low dose dopamine 〔5 μg/（kg·min）〕 by injecting arterial or tail vein. Rats were sacrificed at 1， 6 and 24 h after the induction of AP. The mRNA expression of ET-3 was evaluated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and pathological changes was observed in rats. Results Expression of ET-3 mRNA could be detected from 1 up to 24 h after the induction of pancreatitis. Expression of ET-3 mRNA of sham operation group was decreased significantly compared with other three groups. Expression of ET-3 mRNA showed a significant decrease by arterial injection dopamine than that by tail vein (P＜0.05， P＜0.01). The pathologic score in AP group was the highest, vein injection group was the next one, and score in sham operation group was the lowest. Conclusion There are significant relationship between inflammation of AP and expression of ET-3 mRNA. Dopamine administration by arterial injection is more effective than that by tail vein injection.
ObjectiveTo observe the changes of choroid, macular microcirculation and retinal light sensitivity (MS) in people with different degrees of myopia and emmetropia, and to analyze the relationship between them and the axial length (AL).MethodsA cross-sectional observational study. From May 2019 to November 2020, 142 people (142 eyes) of different degrees of myopia and volunteers from Nanchang Aier Eye Hospital were included in the study. All subjects underwent comprehensive optometry, OCT angiography (OCTA), micro-perimetry examination, and axial length (AL) measurement. A frequency domain OCTA instrument was used to measure the blood flow density of the superficial retinal capillary plexus (SVD), the blood flow density of the deep capillary plexus (DVD), the area of the foveal avascular zone (FAZ) and the choroidal capillaries in the 6 mm×6 mm area of the macula, and percentage of vascular blood flow blank area (FD). The macular integrity assessment instrument was used to measure macular 10° retinal MS and macular fovea 2°, 4° fixation rate (P1, P2), 63% and 95% hyperbolic ellipse area (BCEA). Pairwise comparisons between groups were tested by the least significant difference method.ResultsAmong 142 eyes, 68 eyes were in male, 74 eyes were in female. According to different equivalent spherical powers (SER), subjects were divided into emmetropia group, low myopia group, moderate myopia group, and high myopia group, with 31 eyes, 36 eyes, 44 eyes, and 31 eyes, respectively. Compared with SER (H=132.776) and AL (F=61.118) of the tested eyes in the 4 groups, the difference was statistically significant. The SVD (P=0.003, 0.002, 0.003) and DVD (P＜0.001,＜0.001, P=0.001) of the emmetropia group, low myopia group, and moderate myopia group were higher than those of the high myopia group, and the difference was statistically significant. The FAZ area of the emmetropia group was higher than that of the moderate myopia group, the difference was statistically significant (P=0.013). The FD percentage of choroidal capillaries in the moderate myopia group and the high myopia group was higher than that of the emmetropia group, the difference was statistically significant (P=0.011, 0.030). MS in the high myopia group was significantly lower than that in the emmetropia group, low myopia group, and moderate myopia group, the difference was statistically significant (P＜0.001,＜0.001, P=0.035). Compared with 63% BCEA, 95% BCEA, P1 and P2 among subjects in the emmetropia group, low myopia group, moderate myopia group, and high myopia group, the difference was not statistically significant (H=6.936, 7.041, 5.450, 4.239; P>0.05). The results of correlation analysis showed that the macular area SVD (r=－0.256, P=0.002), DVD (r=－0.465, P＜0.001), FAZ area (r=－0.308, P＜0.001) were negatively correlated with AL. The percentage of FD of choroidal capillaries was positively correlated with AL (r=0.170, P=0.043). Retinal MS was positively correlated with SVD (r=0.252, P=0.003), DVD (r=0.298, P＜0.001), FAZ area (r=0.334, P＜0.001), it was negatively correlated with AL (r=－0.439, P＜0.001), it was not related to the percentage of FD of choroidal capillaries (r=－0.061, P=0.473).ConclusionsWith the increase of myopic refractive power and AL, the macular area SVD, DVD, and retinal MS all show a downward trend. The decline of retinal MS is related to the decrease of SVD and DVD.