Flip-over of blood vessel intima caused by vascular closure device: A case report.

BACKGROUND: Complications of vascular closure devices mainly include bleeding, vascular injury, and trapped device that cannot be removed percutaneously. However, arterial stenosis or occlusion induced by vascular injury is rare. This article introduces a rare case with severe acute limb ischemia after using the vascular closure device (StarClose). CASE SUMMARY: A 54-year-old man was admitted because of necrosis of the second toe of the left foot for 2 mo. Ultrasound showed left femoral artery stenosis, and occlusion of the left popliteal, posterior tibial, peroneal, anterior tibial and dorsalis pedis arteries, suggesting arteriosclerosis obliterans of low extremities, gangrene and type 2 diabetes. He underwent an interventional procedure of drug-eluting balloon in the left lower limb via antegrade puncture of the left common femoral artery. He developed acute limb ischemia after 1 h, and severe pain, numbness, pale skin, low skin temperature and weakened sensation in the left foot. Injury of the common femoral artery intima was considered. Exploratory surgery showed occlusion at the puncture point accompanied with bulged vascular lumen and flipped vascular intima caused by StarClose. The flipped intima was removed. The limb blood supply was restored and the limb was saved post-surgery. He recovered well at final follow-up. CONCLUSION: Incorrect use of the vascular closure device was the main cause of severe acute limb ischemia in this case.

[Effects of stand structure regulation on soil labile organic carbon in Pinus elliottii plantation].

Taking 21-year-old Pinus elliottii pure plantation as the control, effects of enrichment planting with broadleaf trees (Liquidambar fornosana) after thinning the conifer trees (P. elliottii) on soil labile organic carbon of different plantations, including 3-year-old, 6-year-old, 9-year-old P. elliottii and 21-year-old P. elliottii-L. fornosana mixed plantations, were investigated. The results showed that the contents of soil dissolved organic carbon (DOC), readily oxidizable organic carbon (ROC), and microbial biomass carbon (MBC) significantly increased in the 6-year-old and 9-year-old plantations compared with those in the 21-year-old P. elliottii pure plantation. Soil labile organic carbon contents in the 21-year-old P. elliottii-L. fornosana mixed plantation increased significantly than those in 3-year-old, 6-year-old, 9-year-old stands, and the DOC, ROC and MBC contents increased by 113.1%, 53.3% and 54.6%, respectively, compared with those in the 21-year-old P. elliottii pure plantation. The results suggested that replanting with broadleaf trees are an effective measure to improve the soil ecological function in pure P. elliottii plantation.

Immobilization of cross-linked phenylalanine ammonia lyase aggregates in microporous silica gel.

A separable and highly-stable enzyme system was developed by adsorption of phenylalanine ammonia lyase (PAL) from Rhodotorula glutinis in amino-functionalized macroporous silica gel and subsequent enzyme crosslinking. This resulted in the formation of cross-linked enzyme aggregates (PAL-CLEAs) into macroporous silica gel (MSG-CLEAs). The effect of adsorptive conditions, type of aggregating agent, its concentration as well as that of cross-linking agent was studied. MSG-CLEAs production was most effective using ammonium sulfate (40%-saturation), followed by cross-linking for 1 h with 1.5% (v/v) glutaraldehyde. The resulting MSG-CLEAs extended the optimal temperature and pH range compared to free PAL and PAL-CLEAs. Moreover, MSG-CLEAs exhibited the excellent stability of the enzyme against various deactivating conditions such as temperature and denaturants, and showed higher storage stability compared to the free PAL and the conventional PAL-CLEAs. Such as, after 6 h incubation at 60°C, the MSG-CLEAs still retained more than 47% of the initial activity whereas PAL-CLEAs only retained 7% of the initial activity. Especially, the MSG-CLEAs exhibited good reusability due to its suitable size and active properties. These results indicated that PAL-CLEAs on MSG might be used as a feasible and efficient solution for improving properties of immobilized enzyme in industrial application.

A simple technique of preparing stable CLEAs of phenylalanine ammonia lyase using co-aggregation with starch and bovine serum albumin.

Cross-linked enzyme aggregates (CLEAs) have been recently proposed as an alternative to conventional immobilization methods on solid carriers. However, the low cross-linking efficiency causes the major activity loss and instability in the conventional protocol for CLEA preparation. Herein, the effects of bovine serum albumin and starch addition on the cross-linking efficiency of CLEAs of phenylalanine ammonia lyase (PAL) from Rhodotorula glutinis were evaluated. A co-aggregation strategy was developed to improve cross-linking efficiency by adding starch and bovine serum albumin (BSA). CLEAs of PAL prepared in the presence of BSA and starch (PSB-CLEAs) retained 36 % activity, whereas CLEAs prepared without BSA and starch (PAL-CLEAs) retained only 8 % activity of the starting enzyme preparation. Compared with PAL-CLEAs, the thermal stability of PSB-CLEAs has improved considerably, maintaining 30 % residual activity after 4 h of incubation at 70 °C, whereas the PAL-CLEAs have only 13 % residual activity. PSB-CLEAs also exhibited the expected increased stability of PAL against hydrophilic organic solvents, superior operability, and higher storage stability. The proposed technique of preparing CLEAs using co-aggregation with starch and BSA would rank among the potential strategies for efficiently preparing robust and highly stable enzyme aggregates.

[Eeffects of Coptis Chinensis on vasoconstrictive activity of isolated thoracic aorta of normoxic and chronic intermittent hypobaric hypoxic rats].

OBJECTIVE: To observe the effects of Coptis Chinensis on vasoconstrictive activity of isolated thoracic aorta rings of normoxic and chronic intermittent hypobaric hypoxic (CIHH) rats, and to investigate the underlying mechanisms. METHODS: Young male Sprague-Dawley rats were randomly divided into normoxic group and CIHH group: the fonnrmer were not given any special treatment; the latter were exposed to hypoxia in a hypobaric chamber simulating 5000 m altitude (PB = 404 mmHg, PO2 = 84 mmHg, 11.1% O2), 6 hours daily for 28 days. The isolated thoracic aorta rings of rats were prepared and perfused in thermostat, and the effects of Coptis on vasoconstrictive activity of aorta rings were recorded, the mechanisms were investigated simultaneouly. RESULTS: Coptis Chinensis significantly decreased NE and KC-induced vasoconstriction of normoxic and CIHH rats' isolated aortic rings, but the inhibitive effects had no obvious discrepancy between the two groups. The contractive amplitude had no marked change after the removal of endothelium. When calculated by Logit Loglinear analysis, IC50 of NE and KCl-induced contractive amplitude in normoxic group were respectively 2.99 g/L and 6.14 g/L, while they were 3.45 g/L and 5.81 g/L in CIHH group. The inhibitive effect of Coptis on vasoconstrictive activity of both groups could be partly decreased by Glibenclamide and nitro-L-arginine methyl ester; Indomethacin suppressed the effect on normoxic group as well. Also Coptis significantly inhibited NE-induced both intracellular and extracellular calciumion-depended vasoconstriction. CONCLUSION: Coptis Chinensis obviously relaxes isolated thoracic aorta rings of normoxic and CIHH rats, but the effects are endothelium-independent and have no marked discrepancy between the two groups. The mechanisms of the effects may be related to the opening of ATP-sensitive K+ channel, raise of nitric oxide concentration in both groups, and the increasing of PGI2 in normoxic group. Besides, Coptis may inhibit sarcoplasmic reticulum releasing Ca2+ and decrease the inflow of extracellular Ca2+ via cell membrane.