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.
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.
【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.
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.
【Abstract】 Objective To investigate the angiogenesis in hypertropic scar tissue of rabbit ears at different periods and to explore a new method to prevent hyperplastic scar. Methods Nineteen Japanese white rabbits(weigthing 2.0-2.5 kg) were made animal models of hypertropic scar of ear. At 10th, 30th, 60th and 90 days, after epithel ization, the microvessel and microcirculation in hyperplastic scar of 8 rabbits were studied by microcirculation microscope and laser Doppler flowmetry. The other 11 rabbits’ right or left ears were randomly chosen into experimental group and control group. At 10 days after epithel ization,40 μL of adenovirus extracellular protein with metalloprotease and thrombospondin 1 domains (Ad-METH1) was injected into tissue of scar along the perimeter of the scar in experimental group. The same volume of empty adenovirus was injected in control group. After 30 days of injection, the gross appearance of 10 rabbits’ ears scar was recorded, the number of microvessel in scarwas counted and HE stainning of scar tissue was performed in experimental and control groups. One additional rabbit was used to evaluate the mRNA and protein expression of METH1 by RT-PCR and Western blot after 3 days of injection. R e sults The average number of microvessel at 10, 30, 60 and 90 days after epithel ization was 42.37 ± 3.89, 49.46 ± 4.13, 33.12± 4.34 and 13.24 ±2.31, respectively; the average value of microcirculatory perfusion at 10, 30, 60 and 90 days after epithetl ization was (37.75 ±2.11), (59.87 ± 6.46), (44.53 ± 6.14) and (29.21 ± 1.84)PU; the density of microvessels and perfusion of microcirculation in scar tissues during prol iferative stage (from 10 to 60 days after epithel ization) were markedly higher than that during mature period (90 days after epithel ization, P lt; 0.05).At 10 to 30 days after epithel ization, the histol igical features of scar showed early stage of prol iferation and prol iferative stage appearance; at 60 days after epithel ization, it is still in prol iferative stage, while some of scars were in mature phase; at 90 days after epithel ization, the histol igical features of scar were mature period appearance. At 3 days after Ad-METH1 injection, METH1 gene was successfully expressed at both mRNA and protein levels in experimental group, but not in control group. At 30 days after injection, the gross appearanceobservation showed that scars in experimental group were flat and soft with the color close to normal, but scars incontrol group were obvious and hard. The number of microvessel of scar tissue was 12.38±2.56 in experimental group and 48.12±6.46 in control group, showing statistically significant difference between two groups(P lt; 0.01). In experimental group, HE staining shows that the density of microvessel and the number of fibroblasts were greatly decreased and collagen fibers arranged regularly. In control group, plenty of fibroblasts and abundant microvessels were observed. Thick and tight collagen fibers were seen in the outer layer of dermis with a irregular arrangement. Conclusion Theanti-angiogenesis by Ad-METH1 may have a promising appl ication in the prevention of human hyperthropic scar.
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 observe the retinal microcirculation changes in chinchilla rabbit with branch retinal vein occlusion (BRVO), and to evaluate the feasibility of laser speckle imaging (LSI) technology as monitoring tool for retinal microcirculation. MethodsTen 4-month-old chinchilla rabbits were used for the experiment, selecting the right eye as the experimental eye. The main retinal vein, adjacent 0.5-1.0 mm to the optic of rabbit retina, was selected to the target vessel under surgical microscope. The software of LSI instrument was used to measure the diameter of target vein and blood flow of 0.2 mm2 area of target vein. The BRVO rabbit model was induced by photodynamic therapy, then measure the diameter and blood flow in the same region using the method as before and after 10 minutes modeled. ResultsThe retinal color pictures, infrared laser and the distribution of blood flow pseudo-color were synchronous displayed by LSI technology. Before and after modeling, the target vessel diameter were (0.104±0.009), (0.128±0.008) mm, and the 0.2 mm2 area blood flow of target vessel were (563.500±28.788), (256.000±53.319) PU. The diameter of target blood vessel after modeling was significantly thicker than before, with the significant difference (t=12.14,P=0.008). The blood flow in 0.2 mm2 area of target vessel was significantly lower than before, also with the significant difference (t=183.00,P=0.009). ConclusionsThe diameter of target vessel of the BRVO rabbit model is enlarged, and the target vessel area of 0.2 mm2 blood flow is reduced significantly. LSI system can monitor the retinal microcirculation real-time and quantitatively.
OBJECTIVE: To study the forms of microcirculation of arterialized venous flap. METHODS: Twenty New Zealand rabbits were equally divided into two groups, arterialized venous flap group (group A) and control group (group B). The microcirculatory haemodynamic of arterialized venous flap was studied through observation of transparent chamber in rabbit’s ears with aspecial TV set with manification of 1000. RESULTS: The blood of arterilized venous flap flowed through venule anastomosis and drained to another venule. CONCLUSION: It is the main form of microcirculation in early stage that blood flows from venule to draining venule by way of communicating networks between venules.
ObjectiveTo observe and analyze the effect of HbA1c level on macular microcirculation in patients with type 2 diabetes mellitus (T2DM).MethodsA cross-sectional study. One hundred and twenty-four T2DM patients (124 eyes) without diabetic retinopathy who diagnosed by the examination of fundus color photography in Lixiang Eye Hospital Of Soochow University during September to December 2017 were enrolled in this study. There were 59 males (59 eyes) and 65 females (65 eyes), with the mean age of 65.06±7.99 years old. All patients underwent BCVA, fundus color photography, and OCT angiography (OCTA). The history of diabetes, hypertension and dyslipidemia were recorded in detail. According to the HbA1c level, patients were divided into three groups, HbA1c ideal control group (group A, HbA1c ＜7%, 67 eyes), HbA1c control group (group B, 7%≤HbA1c≤9%, 44 eyes), and HbA1c poor control group (group C, HbA1c＞9%, 13 eyes), respectively. The 3 mm×3 mm range of the macular area was scanned by OCTA instrument. The vascular density (VD) and skeleton density (SD) of nonsegmented retinal layer (NRL), superficial retinal layer (SRL) and deep retinal layer (DRL) in the macular area and foveal avascular zone (FAZ) area, non-circularity index, axial rate (AR) of SRL were measured. The correlation between HbA1c, BCVA and VD, SD of NRL, SRL, DRL was analyzed statistically with Spearman correlation test. The correlation between systemic factors and the above indicators was analyzed statistically with linear regression analysis.ResultsThe results of linear regression analysis showed that HbA1c was significantly correlated with VD (t=−3.237, −3.156, −2.050) and SD (t=−0.3.45, −3.034, −2.248) of NRL, SRL and DRL (P＜0.05); but no correlation with FAZ, non-circularity index and AR (t=1.739, 0.429, 1.155; P＞0.05). The differences of VD (F=6.349, 5.981, 3.709), SD (F=7.275, 6.085, 1.904) and AR (F=0.027) of NRL, SRL and DRL in group A, B and C were statistically significant (P＜0.05); but the differences of FAZ (F=1.904), non-circularity index (F=0.280) was not statistically significant (P＞0.05). Significant differences (P＜0.05) of VD and SD of NRL were found between group A and B (t=1.987, 2.201), group A and C (t=3.365, 3.572), group B and C (t=2.010, 2.076). Significant differences (P＜0.05) of VD and SD of SRL were found between group A and B (t=2.087, 2.168), group A and C (t=3.197, 3.194). There were significant differences (P＜0.05) in SD of DRL between group A and B (t=2.239), group A and C (t=−2.519). There was significant difference in VD of DRL between group A and C (t=2.363). The results of Spearman correlation analysis showed that HbA1c was negatively correlated with VD (r=−0.273, −0.255, −0.222; P=0.002, 0.004, 0.013) and SD (r=−0.275, −0.236, −0.254; P＜0.05) of NRL, SRL, DRL; positively correlated with FAZ and BCVA (r=0.221, 0.183; P＜0.05). BCVA was negatively correlated with VD (r=−0.210, −0.190, −0.245) and SD (r=−0.239, −0.207, −0.296) of NRL, SRL, and DRL (P＜0.05), but not correlated with FAZ (r=0.099, P＞0.05).ConclusionThe decrease of macular perfusion and the morphological change of FAZ accompanied by HbA1c increased.