A deep insight into ferroptosis in lung disease: facts and perspectives

In the last decade, ferroptosis has received much attention from the scientific research community. It differs from other modes of cell death at the morphological, biochemical, and genetic levels. Ferroptosis is mainly characterized by non-apoptotic iron-dependent cell death caused by iron-dependent lipid peroxide excess and is accompanied by abnormal iron metabolism and oxidative stress. In recent years, more and more studies have shown that ferroptosis is closely related to the occurrence and development of lung diseases. COPD, asthma, lung injury, lung fibrosis, lung cancer, lung infection and other respiratory diseases have become the third most common chronic diseases worldwide, bringing serious economic and psychological burden to people around the world. However, the exact mechanism by which ferroptosis is involved in the development and progression of lung diseases has not been fully revealed. In this manuscript, we describe the mechanism of ferroptosis, targeting of ferroptosis related signaling pathways and proteins, summarize the relationship between ferroptosis and respiratory diseases, and explore the intervention and targeted therapy of ferroptosis for respiratory diseases.

Lagged feedback of peak season photosynthetic activities on local surface temperature in Inner Mongolia, China

Increased vegetation peak growth and phenological shifts toward spring have been observed in response to climate warming in the temperate regions. Such changes have the potential to modify warming by perturbing land‒atmosphere energy exchanges; however, the signs and magnitudes of biophysical feedback on surface temperature in different biomes are largely unknown. Here, we synthesized information from vegetation growth proxies, land surface temperature (LST), and surface energy balance factors (surface evapotranspiration (ET), albedo, and broadband emissivity (BBE)) to investigate the variations in timing (PPT) and productivity (PPmax) of seasonal peak photosynthesis and their time-lagged biophysical feedbacks to the post-season LST in Inner Mongolia (IM) during 2001-2020. We found that increased PPmax, rather than advanced PPT, exhibited a significant impact on LST, with divergent signs and magnitudes across diurnal periods and among different biomes. In the grassland biome, increased PPmax cooled both LST during daytime (LSTday) and nighttime (LSTnight) throughout the post-season period, with a more pronounced response during daytime and diminishing gradually from July to September. This cooling effect on LST was primarily attributed to enhanced ET, as evidenced by the greater effect of ET cooling than that of albedo warming and BBE cooling based on a structural equation model (SEM). In the forest biome, increased PPmax led to a symmetrical warming effect on LSTday and LSTnight, and none of the surface energy balance factors were identified as significant intermediate explanatory factors for the observed warming effect. Moreover, the responses of average LST (LSTmean) and diurnal temperature range of LST (LSTDTR) to variations in PPmax were consistent with those of LSTday at two biomes. The observations above elucidate the divergent feedback mechanisms of vegetation peak growth on LST among different biomes and diurnal cycles, which could facilitate the improvement of the realistic parameterization of surface processes in global climate models.

Positive change in asthma control using therapeutic patient education in severe uncontrolled asthma: a one-year prospective study

Background

Severe asthma is difficult to control. Therapeutic patient education enables patients to better understand their disease and cope with treatment, but the effect of therapeutic patient education in severe uncontrolled asthma is unclear. We evaluated whether therapeutic patient education is effective in improving asthma control and decreasing the frequency of exacerbations in severe uncontrolled asthma.

Methods

This was a prospective, observational, and self-controlled study that enrolled 40 subjects with severe uncontrolled asthma. Patients were seen at a clinic four times (on day 1 and after 3, 6, and 12 months). After baseline data collection, the subjects completed a therapeutic patient education program and were also followed-up via telephone after 1, 2, 4, 5, 7, 8, 9, 10, and 11 months to monitor asthma medication adherence and collect asthma-related information.

Results

Within the 1-year study period, a total of 23 exacerbations were recorded in 14 patients, seven of whom required emergency treatment and two of whom were hospitalized. Twelve months after the standardized therapeutic patient education program, pulmonary function and fractional exhaled nitric oxide levels improved significantly in all 40 patients. Moreover, the scores from three standardized asthma questionnaires and indices suggested improved quality of life in these patients with severe uncontrolled asthma. Serum levels of biomarkers reflecting asthma immune responses did not change between baseline and the 1-year follow-up time point.

Conclusions

Therapeutic patient education is effective in improving asthma control and decreasing exacerbations in patients with severe uncontrolled asthma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40733-021-00076-y.

Short-term outcomes of COVID-19 and risk factors for progression

Coronavirus disease 2019 (COVID-19) has now become a worldwide health concern. The severity of COVID-19 has been classified as mild, moderate, severe and critical [1]. To date, there have been a few studies focused on the clinical course and outcome of critical cases [2–4]. However, information regarding outcomes of mild-to-moderate cases is lacking, despite the fact that mild-to-moderate cases have accounted for approximately 80% of laboratory-confirmed patients [1, 5]. This study aimed to investigate short-term outcomes of patients rated with different severities on admission, and to identify risk factors for progression, thereby helping the management of COVID-19 in clinical practice.

With a median (IQR) follow-up time of 24.0 (17.5–30.0) days, progression occurred in 19.6% moderate, 27.8% severe and 66.7% critical COVID-19. Neutrophil-to-lymphocyte ratio ≥2.973, age ≥50 years, male sex and comorbidity were associated with progression.https://bit.ly/3crsJr0

Coronavirus Disease 2019 in a Hemodialysis Patient

There has been a global outbreak of the coronavirus disease 2019 (COVID-19) since December 2019. Here, we describe the case of a 49-year-old male undergoing maintenance hemodialysis (HD) who got infected with COVID-19 and our experience in performing HD for him. The patient's symptoms and lung imaging changes were atypical. However, his lymphocyte range decreased upon admission and the polymerase chain reaction of the pharyngeal swab for the -COVID-19 nucleic acid was positive. The patient developed respiratory failure and required mechanical ventilation 8 days after admission. In the end, he died from multiple organ dysfunction syndrome. The difficulties in diagnosis, infection control, and treatment of COVID-19 in maintenance HD patients are discussed in this report.

Evaluating and comparing remote sensing terrestrial GPP models for their response to climate variability and CO2 trends

Remote sensing (RS)-based models play an important role in estimating and monitoring terrestrial ecosystem gross primary productivity (GPP). Several RS-based GPP models have been developed using different criteria, yet the sensitivities to environmental factors vary among models; thus, a comparison of model sensitivity is necessary for analyzing and interpreting results and for choosing suitable models. In this study, we globally evaluated and compared the sensitivities of 14 RS-based models (2 process-, 4 vegetation-index-, 5 light-use-efficiency, and 3 machine-learning-based models) and benchmarked them against GPP responses to climatic factors measured at flux sites and to elevated CO₂ concentrations measured at free-air CO₂ enrichment experiment sites. The results demonstrated that the models with relatively high sensitivity to increasing atmospheric CO₂ concentrations showed a higher increasing GPP trend. The fundamental difference in the CO₂ effect in the models' algorithm either considers the effect of CO₂ through changes in greenness indices (nine models) or introduces the influences on photosynthesis (three models). The overall effects of temperature and radiation, in terms of both magnitude and sign, vary among the models, while the models respond relatively consistently to variations in precipitation. Spatially, larger differences among model sensitivity to climatic factors occur in the tropics; at high latitudes, models have a consistent and obvious positive response to variations in temperature and radiation, and precipitation significantly enhances the GPP in mid-latitudes. Compared with the results calculated by flux-site measurements, the model performance differed substantially among different sites. However, the sensitivities of most models are basically within the confidence interval of the flux-site results. In general, the comparison revealed that models differed substantially in the effect of environmental regulations, particularly CO₂ fertilization and water stress, on GPP, and none of the models performed consistently better across the different ecosystems and under the various external conditions.

Spatial distribution and temporal variation of drought in Inner Mongolia during 1901-2014 using Standardized Precipitation Evapotranspiration Index

With intensification of climate change and human activities, warming and drying trend has brought severe challenges to pastoral areas in arid and semi-arid regions. Consequently, it becomes imperative to explore non-stationarity features of drought in such regions. In this research, the SPEIbase v2.4 datasets with a 0.5 degree spatial resolution was employed to extract Standardized Precipitation Evapotranspiration Index (SPEI) in Inner Mongolia, China. We explored non-stationarity characteristics of drought using Breaks For Additive Seasonal and Trend (BFAST) method, investigated the variation characteristics of drought intensity in each time interval using intensity analysis method, and finally assessed the spatial and temporal gathering characteristics of drought with Empirical Orthogonal Function (EOF). The results showed that trend of regional drought had a tendency towards drought conditions, which is particularly significant from the year 1945 onwards in the overall Inner Mongolia. We have explored a long behavior of drought in semiarid and central regions of cold semihumid climate zone throughout the whole study period, and detected a drying trend in northeastern regions of Inner Mongolia at the latter decades. The overall drought intensity displayed an increasing trend first, which was followed by a decreasing trend, among which the extreme drought was dominant in period of 1960-1970. EOF mode1 showed that variation intensity of drought showed a not significantly increasing trend in the entire region, and the drought with high amplitude was likely to occur in the central region. EOF mode2 showed that variation intensity of drought displayed the opposite phases between the eastern and the western regions. The northeastern regions were prone to display a high amplitude of drought.

Effect of propranolol on proliferation and apoptosis of hemangioma endothelial cells in infants and young children

The aim of this study was to investigate the effects of propranolol on the proliferation and apoptosis of hemangioma endothelial cells in infants and young children, and to explore the molecular mechanism of hemangioma treatment. Infant HemEC was cultured in vitro. HemEC cells were treated with different concentrations of propranolol (0umol/L, 25umol/L, 50umol/L, 75umol/L, 100umol/L, 125umol/L). After 24, 48 and 72 hours, the viability of the cells was examined by MTT {3-(4, 5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide} method. The apoptosis rate of the cells was measured by flow cytometry using Annexin V. The propranolol concentration was 25umol/L. After 24 h and 48 h, HemEC could slightly proliferate (P<0.05). With the concentration of ≥100umol/L, the survival time of HemEC decreased when the action time was longer than 24 h. Within a certain range, the drug efficacy was positively correlated with drug concentration and action time (P<0.05). When propranolol concentration was ≥100umol/L, it could cause HemEC apoptosis. With the increase of drug concentration and the prolongation of intervention time, the apoptosis rate increased (P<0.05). In conclusion, the inhibition of hemangiomas by propranolol may be related to the inhibition of HemEC proliferation and its promotion of apoptosis.

Dynamics and ecological risk assessment of chromophoric dissolved organic matter in the Yinma River Watershed: Rivers, reservoirs, and urban waters

The extensive use of a geographic information system (GIS) and remote sensing in ecological risk assessment from a spatiotemporal perspective complements ecological environment management. Chromophoric dissolved organic matter (CDOM), which is a complex mixture of organic matter that can be estimated via remote sensing, carries and produces carcinogenic disinfection by-products and organic pollutants in various aquatic environments. This paper reports the first ecological risk assessment, which was conducted in 2016, of CDOM in the Yinma River watershed including riverine waters, reservoir waters, and urban waters. Referring to the risk formation theory of natural disaster, the entropy evaluation method and DPSIR (driving force-pressure-state-impact-response) framework were coupled to establish a hazard and vulnerability index with multisource data, i.e., meteorological, remote sensing, experimental, and socioeconomic data, of this watershed. This ecological vulnerability assessment indicator system contains 23 indicators with respect to ecological sensitivity, ecological pressure, and self-resilience. The characteristics of CDOM absorption parameters from different waters showed higher aromatic content and molecular weights in May because of increased terrestrial inputs. The assessment results indicated that the overall ecosystem risk in the study area was focused in the extremely, heavily, and moderately vulnerable regions. The ecological risk assessment results objectively reflect the regional ecological environment and demonstrate the potential of ecological risk assessment of pollutants over traditional chemical measurements.

Cortical microstructure compensates for smaller bone size in young Caribbean Hispanic versus non-Hispanic white men

Hispanic men have smaller bone size but thicker and denser cortices compared to white men, leading to similar mechanical competence.

INTRODUCTION

The purpose of this study was to assess differences in vBMD and microarchitecture in young Caribbean Hispanic (n = 30) and non-Hispanic Caucasian (n = 30) men.

METHODS

We measured areal bone mineral density (aBMD) at the spine, total hip (TH), femoral neck (FN), and forearm by dual-energy X-ray absorptiometry (DXA) and bone geometry, mass, microarchitecture, and mechanical competence by high-resolution peripheral quantitative computed tomography (HRpQCT), individual trabecula segmentation (ITS), and finite element analysis (FEA).

RESULTS

Hispanic men were slightly older, shorter, and heavier and had higher BMI compared with white men. aBMD, measured by DXA, did not differ at the spine, TH, or forearm before or after adjustment for age, height, weight, and the interaction of height and weight. At the FN, marginally significant higher BMD in Hispanics prior to adjustment was attenuated and no longer differed after adjustment for covariates. Adjusted HRpQCT indices indicated smaller total and trabecular area at the radius but greater total volumetric density and cortical thickness in Hispanic versus white men. The adjusted difference in cortical density at the radius was of borderline significance. Trabecular and ITS microstructure tended not to differ at the radius. At the tibia, results were similar. Bone size tended to be smaller and covariate-adjusted cortical density and cortical thickness were greater in Hispanic versus white men. Additionally, cortical porosity was lower at the tibia in Hispanic compared to white men. Stiffness and failure load did not differ at either skeletal site by ethnicity.

CONCLUSION

In conclusion, greater cortical thickness and density as well as lower cortical porosity tend to compensate for smaller bone size in Hispanic men, leading to similar mechanical competence compared with white men.

MiR-200c and miR-141 inhibit ZEB1 synergistically and suppress glioma cell growth and migration

OBJECTIVE

This study aimed to investigate the expression of miR-200c and miR-141 in glioma tissues and cell lines and then to study their regulative effect on ZEB1 expression and on glioma cell growth and migration.

MATERIALS AND METHODS

QRT-PCR analysis was performed to detect miR-200c and miR-141 expression in 10 paired glioma tissues and adjacent normal tissues from patients with glioblastoma multiforme (GBM) and in glioma cell lines. U87 and U251 cells were transfected with miR-200c mimics, miR-141 mimics or ZEB1 siRNA respectively. ZEB1 expression was detected qRT-PCR and Western blot assay. MTT assay, flow cytometry and wound healing assay were performed to examine the tumor suppressive effects of the miR-200c/miR-141-ZEB1 axis on glioma cells.

RESULTS

Both miR-200c and miR-141 were significantly lower in glioma tissues than in adjacent normal tissues. The glioma cell lines, including U87, U251 and A172 also had significantly decreased miR-200c and miR-141 expression than normal tissues. ZEB1 expression had at least two-fold increase in glioma tissues than in normal tissues. Both miR-200c and miR-141 could significantly induce ZEB1 mRNA degradation and suppress ZEB1 protein expression. ZEB1 siRNA presented similar growth and migration inhibiting and apoptosis inducing effect to miR-200c and miR-141 mimics in U87 cells.

CONCLUSIONS

MiR-200c and miR-141 are significantly downregulated in glioma tissues and cell lines and can significantly induce ZEB1 mRNA degradation and suppress ZEB1 protein expression in the cells. ZEB1 is a functional downstream target of miR-200c and miR-141 in inhibiting glioma cell growth and migration.

Leukotriene D4 inhalation challenge for predicting short-term efficacy of montelukast: a pilot study

INTRODUCTION

The convenient measure to predict efficacy of leukotriene receptor antagonist is lacking.

OBJECTIVES

To determine if leukotriene D4 inhalation challenge predicts short-term efficacy of montelukast in asthma.

METHODS

In this open-labelled 28-day trial, 45 patients with asthma were allocated to leukotriene-sensitive and leukotriene-insensitive group to receive montelukast monotherapy (10 mg, once daily) based on the positive threshold of leukotriene D4 inhalation challenge test (4.800 nmol). Miscellaneous measurements comprised fractional exhaled nitric oxide, methacholine inhalation challenge, Asthma Control Test and Asthma Quality of Life Questionnaire. Peak expiratory flow was self-monitored throughout the treatment. End point assessments were performed 3 to 5 days after montelukast withdrawal.

RESULTS

Twenty-three patients in leukotriene-sensitive group and 10 leukotriene-insensitive group completed the study. Both groups differed neither in 28-day peak expiratory flow rate nor in maximal weekly peak expiratory flow (both P > 0.05). However, minimal weekly peak expiratory flow was significantly higher in leukotriene-insensitive group throughout the treatment course (all P < 0.05) except for week 1 (P > 0.05). Both groups did not differ statistically in the post-treatment improvement in forced expiratory volume in 1 s (FEV1 ) predicted% prior to inhalation challenge, fractional exhaled nitric oxide or the airway responsiveness to leukotriene D4 or methacholine (all P > 0.05). There was a marked increase in Asthma Control Test score and the symptom score of Asthma Quality of Life Questionnaire in both groups (both P < 0.05). The overall significance of Logistic regression model was unremarkable (P = 0.467).

CONCLUSION

Responsiveness to inhaled leukotriene D4 alone might not be sufficient to predict the short-term efficacy of montelukast monotherapy in patients with asthma.

Effects of liver diseases on drug-metabolizing enzymes: implications for drug fate alterations and nano-therapeutic openings

Metabolizing and eliminating toxic chemicals in the liver are key processes in the body's defense system. Drug-metabolizing enzymes (DMEs) play central roles in such processes. The activity and expression of several key DMEs are changed in various liver diseases and thus lead to significantly altered drug disposition. This phenomenon severely affects the pharmacotherapy of clinical medications in terms of the safety and efficacy of drug responses. This review highlights liver physiological functions, altered DMEs, and altered drug disposition in liver diseases. Moreover, the implications of changes in DMEs on the fate of clinically relevant drugs are also discussed. Pregnane X receptor and constitutive androstane receptor are two liver-enriched nuclear receptors originally defined as xenobiotic sensors that affect regulation of DMEs. Altered regulation of DMEs in liver diseases contributes to the development of powerful in vitro and in vivo tools to predict drug responses and options for improved drug delivery and development. Although a number of treatment drugs are available for liver diseases, they are limited by their low drug concentration in the target site, presence of side effects, and instability in the human body. The nanoparticle drug delivery system has recently attracted research attention because of its potential to offer solutions to current obstacles that involve the use of therapeutic drugs for liver diseases. Conclusively, this review aims to improve understanding on the regulation of DMEs in liver diseases and on corresponding implications in drug disposition, including novel therapeutic medications.

TRAF2 docking with related proteins in silico studies

Using the protein-protein docking program, this study investigates the relationship between TRAF2 and its related proteins and the diversity within the 3D structures of TRAF2s. TRAF2 exists in monomer, trimer, and hexamer forms and it can combine with a number of proteins. Through comparative analysis we found that TRAF2(122), TRAF2(22), TRAF2(21740), TRAF2(2), TRAF2( 22ABC), and TRAF2(Phyre) perform very close homoousia in docking with the same group of ligands, though these TRAF2s come from different sources. The TRAF2-related proteins of cluster 1 change docking values strongly from top to bottom. The TRAF2- related proteins of clusters 2 and 3 have acceptable variation of the docking values. In consideration of the amino acid percentage, TRAF2-related proteins of cluster 2 represent appropriate docking values.

[The effect of L-arginine on the microcirculation reperfusion of cremaster muscle in rats]

OBJECTIVE

To investigate the effect of L-arginine and the role of nitric oxide (NO) on the microcirculation of cremaster muscle after the ischemia-reperfusion.

METHODS

A group of male Sprague-Dawley rats, each weighing 180-220 g, were surgically prepared with the neurovascular bundle freed only to connect to the cremaster muscle, subjected to 5 hours warm ischemia and 2 hours of reperfusion, and treated with L-arginine. The microcirculation was observed with the measurement of the arteriole in diameter under intravital microscopy.

RESULTS

1. The arteriole re-flowing with the L-arginine treatment was significantly higher than the saline control with only 53% in 30 minutes after the reperfusion (P < 0.01). 2. The diameter of the reflowed arteriole and the perfused capillary density were increasing greatly with the L-arginine treatment, compared to the control group. 3. The pathological phenomena of "only irrigation and no reflow" was observed in local muscle microcirculation, which subsequently resulted in the large-scale leakage hemorrhage.

CONCLUSIONS

The nitric oxide product could relieve the vasospasm and decrease the no-reflow of skeletal muscular during reperfusion; The venular no-reflow resulted from venular thrombi may play an important part during the tissue reperfusion injury.

[Anatomicopathological relation between facial nerve and large vestibular Schwannoma]

OBJECTIVE

To study the anatomicopathological relation between facial nerve and large vestibular schwannoma.

METHODS

Operation by suboccipital retrosigmoid sinus approach was performed on 40 cases with large vestibular schwannoma, During the operation, the anatomicopathological relation between the facial nerve and the vestibular schwannoma was observed directly.

RESULTS

The facial nerve was found to be located ventrally (deep under the tumor), dorsally (over the tumor), at the upper pole of the tumor (near the tentorium cerebelli), at the lower pole of the tumor (near the rear group cranial nerves), or aberrant (unable to be identified because of infiltration of tumor). In 31 cases, mainly with parenchymatous tumor, the facial nerve was flat in shape. In 9 cases, mainly with cystic tumor, the facial nerve was bandlike.

CONCLUSION

The facial nerve varies greatly in neuroanatomy among patients with large vestibular schwannoma. Strengthening of operative monitoring can increase the safety of operation.

[Experimental study on selective thrombolytic activity of pro-urokinase]

OBJECTIVE

To evaluate the valve of pro-urokinase as a selective thrombolytic agent in microsurgery.

METHODS

The levators muscle model in rats was used to investigate the effect of pro-urokinase on dissolving ischemic thrombi and fibrinogenolytic activities in circulation by local infusion. The tissue microcirculation, pathologic appearance of rat lungs and muscles, and general fibrinogenolytic activities were observed.

RESULTS

The thrombolytic rate of pro-urokinase was 92.3% (P < 0.05), the positive rate of D-dime was 83.3%(P < 0.05). No significant change of alpha 2-PI was observed on general fibrinogenolytic activities(P > 0.05).

CONCLUSIONS

It is suggested that pro-urokinase can be used to dissolve the thrombi in microcirculation of free tissue transplantation without affect general fibrinogenolytic activities. It is safe to use pro-urokinase in free tissue transplantation.

[Influence of reperfusion following ischemia on microvessels and microcirculation of skeletal muscle]

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 the peritenon, which was characterized by "no reflow" in most area and there was significant 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.

[Study on intravascular pressure change during sclerotherapy for cavernous hemangiomas (CHs)]

To investigate the regulation and significance of the intravascular pressure change of cavernous hemangiomas during the treatment of sclerotherapy, we did observations in 29 cases with slowing down the efferent blood flow of the CHs in their treatment. It was found that the baseline intravascular pressure of CHs is 5-15 mmHg, the lowest being at the neck. The efferent rate of CHs is higher than the afferent rate. The higher the efferent rate, the more times of injection and more amount of thrombotic agent were needed. At the beginning of the thrombosis, the CHs pressure rose gradually to a flat curve, which suggested that the efferent veins were being thrombosed one by one. Then the CHs pressure curve became a blunt peak, which suggested that all the efferent veins were thrombosed and it was time to inject the sclerosing agent. Finally the CHs pressure curve became a sharp peak, suggesting that the whole CHs was thrombosed and sclerosed. Follow-up from 6 months to 3 years revealed that CHs disappeared in 26 of 29 cases, recurred in 3 cases. No severe complications were found. The authors concluded that the treatment can improve the curative effect and decrease complications.

[Experimental study on vascularized area of the prefabricated axial skin flap after implantation of vascular bundles]

Thirty-eight New Zealand white male rabbits were used to study vascularized area of the prefabricated axial skin flaps (PASFs) after implantation of vascular bundles (VBs) into subcutaneous tissues of the animal's abdomen. Influential factors were investigated including the interval after implantation, the size of VBs, the subcutaneous layer where VBs were implanted and simultaneous skin expansion. The results indicated that the suitable time for PASFs transferring was 3-4 weeks after implantation of VBs. The VBs of larger diameter prefabricated larger area of PASFs. Larger areas of PASFs were created by implanting VBs into the subcutaneous layers that possessed rich vascular plexuses. It was possible that the expanded PASFs could be transferred.

[Effects of electret and Ligusticum wallichii (chuangxiong) on the functional recovery of muscle grafts]

The aim of this study was to evaluate the effects of electret and Ligusticum wallichii (Chuangxiong, a traditional Chinese herb medicine) on the functional recovery of muscle grafts. Twenty-eight adult dogs were divided into 4 groups with each consisting of 7 animals. After orthotopical transplantation of bilateral rectus femoris muscle with neurovascular anastomosis, group A received electret local implant, group B received Chuangxiong injection, group C received both electret local implant and Chuangxiong injection and group D was used as control. The results showed that the functional recovery of the transplanted rectus femoris muscle in group A and B was better than group D while group C was the best. At 22 postoperative weeks, the recovery rate of maximal tetanic tension was 64.94 +/- 3.82% in group c: 57.68 +/- 1.67% in group A, 53.64 +/- 3.82% in group B and 47.99 +/- 2.21% in group D (P < 0.05). The structural recovery of the transplanted muscle in group C was closest to the normal.

[Changes in surface microcirculation of extensor digitorum longus tendon after ischemia-reperfusion of rabbit hindlimbs]

The circulation was stopped by tourniquet in one rabbit hindlimb. After 2 or 5 hr of ischemia, the hindlimb was reperfused. During the first 1 hr of reperfusion, dynamic changes in surface microcirculation of extensor digitorum longus tendon were observed by using intravital microscopy. Particular attention was paid to leukocyte-endothelium adhesion and microvascular perfusion condition. It was found that 1) the number of leukocytes adherent to the venular endothelium of ischemic tissue significantly increased following reperfusion and the degree of increases appeared to be directly related to the duration of ischemic period; 2) reperfusion after 5 hr of ischemia could result in the formation of "no reflow phenomenon" in the ischemic tissues, including "primary no reflow" and "secondary capillary perfusion failure". These results suggest that 1) leukocyte-endothelium adhesion may contribute to the development of ischemia reperfusion injury; 2) in the limbs undergone 5 hr of ischemia, not all injuries that occur after ischemi-reperfusion can be attributed to ischemia reperfusion injury. The injury seen some in areas may be produced by ischemia alone, and in others ischemia-reperfusion-secondary ischemia injury may be responsible.

[Anastomosis of small artery using ZT medical adhesive and soluble stent]

The conventional technique of interrupted suture in microvascular anastomosis is difficult to perform and timeconsuming. A new method with ZT medical adhesive and soluble intravascular stent is introduced. Using this method, end-to-end anastomosis of small arteries could be performed easily and quickly. Both the patency rate and histopathologic changes at the anastomosis sites were examined. In comparison with suture technique, similar patency rate was obtained. Inflammatory reaction in mid and outer layers of the vessel was observable and reendothelialization of the intima was identical.

[Free medial leg flap with fasciocutaneous branch of tibial nutrient artery]

According to the results of anatomical study in 20 fresh cadaver legs and transparent specimens of 10 medial leg flaps, it is found that the tibial nutrient artery arises from the posterior tibial artery and runs obliquely downwards close to the surface of the popliteal muscle, and at the level of 61.62 +/- 15 mm below the tibial tuberosity it sends out the fasciocutaneous branch, which becomes one of the main nutritional vessels of the medial area of the leg. Vascularized transplantation of the medial leg free flap which is supplied by the fasciocutaneous branch of the above named artery has been undertaken with satisfactory results clinically.

[Experimental studies on microcirculation of the hindlimb after ischemia and reperfusion in the rabbits. 1. Establishment of an in vivo method for observing microcirculation using tendon surface microvessels on the dorsum of the foot]

The blood supply system of the extensor digitorum longus tendon in the rabbit hindlimb is observed by the aid of dye injection technique and dissecting microscope. We find that the segment proximal to metatarsophalangeal joint of this tendon is an ideal site for observation of in vivo microcirculation. In this site, there are abundant microvessels on the surface of the tendon, and as red microvessels are on white tendon, it forms a sharp contrast. In addition, the tendon is only covered by skin and little loose connective tissue, so it is easy to expose. On the bases of abovementioned findings, a new in vivo method for observing microcirculation in the rabbit hindlimb is developed. In our experiences, the advantages of this method are as follows: (1) It is simple and convenient; (2) The time required for preparation is short (about 10-15 min), and the observation period can be extended (over 6 h.); (3) Surgical trauma is not serious; (4) The image is clear. This method opens up a new way to using rabbit hindlimb ischemia model to study microcirculation changes in vivo following reperfusion after extremity ischemia.