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 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.
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.
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 assess the efficacy and safety of Hirudoid for microcirculation disorder. Methods?We searched The Cochrane Library (Issue 4, 2009), PubMed, EMbase, CNKI, CBM, and VIP databases up to December 2009. Randomized controlled trials (RCTs) or quasi-RCTs concerning Hirudoid for microcirculation disorder were included. The methodological quality of the included studies was assessed according to the Cochrane Reviewer’s Handbook 5.0.1, and meta-analyses were conducted using RevMan software 5.0. Results?Twenty-five RCTs were included, of which only one was graded as high quality and others were of low quality. The results of meta-analyses showed: Hirudoid could be effective in preventing the occurrence of phlebitis (OR=0.18, 95%CI 0.13 to 0.25). Hirudoid for treating phlebitis was also significantly better than magnesium sulfate or placebo (OR=7.18, 95%CI 4.59 to 11.22) and the time to symptom relief of Hirudoid was significantly shorter than placebo (MD= –?29, 95%CI –?37.30 to –?20.70). Hirudoid for internal fistula in hemodialysis patients was better than the simple hot compress (OR=8.89, 95%CI 4.25 to 18.58), and also better than the magnesium sulfate plus hot compress (OR=7.62, 95%CI 2.84 to 20.44). Hirudoid could also prevent the formation of hematoma and eliminate hematoma quickly. Hirudoid for tissue injury caused by irritating fluid extravasation was significantly better than magnesium sulfate (OR=4.25, 95%CI 2.06 to 8.78). Conclusion?Hirudoid can significantly improve the microcirculation disorder, especially to the phlebitis. Due to the low quality of the included studies, further, more high quality trials are required.
【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.
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.
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.
In order to investigate the survival mechanism and the role of venous drainage in arterialized venous skin flap, 60 rabbits’ ears were used for research and clinical application of the flap was performed subsequently in two cases. The rabbits were divided into 4 groups. Experimental group was standard arterialized venous skin flap, control 1 group was venous skin flap, control 2 group was arterialized venous skin flap with only one drainage vein and control 3 group was normal skin flap. The process of survival of the flaps was observed by hemodynamic and histological method. The results showed that there was no significant difference between standard arterialized venous skin flap and normal skin flap (P gt; 0.01). Two cases of arterialized venous skin flap survived completely. The conclusion were as follow: 1. the opening of collateral circulation between the veinlets was the main change of the microcirculation; 2. the blood flow of the graft was changed from unphysiological circulation to physiological circulation as the time elapsed and 3. amelioration of venous drainage was important in inproving the survival rate of arterialized vein graft.
