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.
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 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.
Objective To explore the effect of renal microcirculation following severity acute pancreatitis （SAP） on renal injury and to explore the protection effect of urokinase on them. Methods A total of 192 Wistar rats were randomized divided into normal control group， SAP group， and urokinase group， then rats of 3 groups were sub-divided into 2， 6， 12， and 24 hours group， each group enrolled 16 rats. Of the 16 rats in each subgroup， 8 rats underwent blood flow of renal test， other 8 rats were sacrificed to get blood samples and to perform histopathological examination. The rat models of SAP were established by retrograde injecting with 5% sodium taurocholate into the cholangiopancreatic duct. Radioactive biomicrosphere technique was used to measure the blood flow of renal， levels of plasma thromboxane B2（TXB2） and 6-keto-prostaglandin F1α （6-Keto-PGF1α） were tested by the TXB2 kit and 6-Keto-PGF1α kit， and histopa-thological changes of renal tissues were observed by using HE staining. Results Compared with normal control group at the same time point， the blood flow of renal were lower （P＜0.05）， activity ratio of TXB2 to 6-Keto-PGF1α were higher（P＜0.01）， and the histopathological injury were worse （P＜0.01） in rats of SAP group and urokinase group. Compared with SAP group， the blood flow of renal at 2， 6， and 12 hours in urokinase group were higher （P＜0.01）， the activity ratios of TXB2 to 6-Keto-PGF1α were lower （P＜0.01）， and the histopathological injury were lighter （P＜0.05） in all the 4 time points of urokinase group. Conclusions The renal microcirculation dysfunction and increase of activity ratio of TXB2 to 6-Keto-PGF1α may play an important role in renal injury following SAP in early stage. Urokinase can protect the renal from such injuries.
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.
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.
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.
【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.