Regulative effects of vessel active drugs on extremital skin temperature of experimental animals exposed to cold / 中国应用生理学杂志

<p><b>OBJECTIVE</b>Using an experimental model of animals exposed to cold to evaluate the regulative effects of prazosin hydrochloride (Pra) and racanisodamine (Ani) on extremital skin temperature of rats and mice.</p><p><b>METHODS</b>Eighty animals were randomly divided into eight groups according to the drug dosage. After been administered with drugs by intragastric at room temperature for 60 min, the animals were moved into specified temperature (5 degrees C,18 degrees C) environment and the skin temperatures at the 1/3 site at the proximal end of tail were measured by infrared camera on 180 min and 300 min. Effects of drug were evaluated by changes in tail skin temperatures.</p><p><b>RESULTS</b>Pra and Ani combination raised the extremital skin temperature of experimental animals significantly in a dose-dependent manner, while single use of Pra was not potent to rats and less potent to mice, and single use of Ani could not raise extremital skin temperature of both rats and mice. Change of rectal temperature in mice showed that Pra and Ani combination did not affect core temperature.</p><p><b>CONCLUSION</b>Pra and Ani combination could significantly raise extremital skin temperature of rats and mice exposed to cold, and would not affect their core (rectal) temperature.</p>

The damage effects of hypothermia combined with hypoxia on rat pulmonary microvascular endothelial cells / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the synergistic effects of hypothermia and hypoxia on the damage of pulmonary microvascular endothelial cells (PMVEC) in rat.</p><p><b>METHODS</b>Primary PMVECs were obtained by complex phosphoesterasum digesting from isolated lung tissues of Wistar rats, the PMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen and bandeiraea simplicifolia isolectin (BSI) binding test. Factorial design was adopted in trial according to hypothermia and hypoxia existing or not. Using corresponding kit measured the levels of lactate dehydrogenase (LDH) activity in cell medium. Level of nitric oxide (NO) concentration was measured by Griess Assay. RT-PCR was used to examine the expression of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) mRNA in PMVECs.</p><p><b>RESULTS</b>The monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were PMVECs. Compared to the control group, LDH activity and VEGF, ET-1 expression levels were significantly increased in hypothermia group, hypoxia group and hypoxia combined with hypothermia group. And the levels of NO concentration were reduced in these three groups. The results of One-way ANOVA showed that there was a synergistic effect between hypothermia and hypoxia.</p><p><b>CONCLUSION</b>Hypothermia and hypoxia both have an effect on PMVECs whether in altering the cell permeability or in releasing of vasoactive substances including NO and ET-1. In addition, there is a synergistic effect between hypothermia and hypoxia.</p>

Effects of low temperature exposure on dermal microvascular endothelial cells function / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the damage effects and expression of vascular endothelial growth factor (VEGF) exposed with different low-temperatures on rat dermal microvascular endothelial cells (DMVECs).</p><p><b>METHODS</b>Primary DMVECs were obtained by discontinuous Percoll gradient centrifugation. The DMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen. Applied 28 degrees C, 12 degrees C and 0 degrees C to interfere with rat DMVECs as cold-exposure model. The changes of cells morphology were observed under invert microscope. The membrane integrity was determined by lactate dehydrogenase (LDH) activity. RT-PCR was used to examine the expression of vascular endothelial growth factor mRNA in cells.</p><p><b>RESULTS</b>The monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were DMVECs. After 24 h cold exposure, the cell morphology of 0 degrees C group was shrunken, the other groups were "Fibroblast-like". The LDH activity (U/L) in the medium of 28 degrees C, 12 degrees C and 0 degrees C groups was 54.17 +/- 3.02, 64.66 +/- 3.03, 82.13 +/- 10.91 respectively, which was significantly higher than that of 37 degrees C group (12.23 +/- 3.0, P < 0.01). The VEGF mRNA expression level was up-regulated in 28 degrees C group and 12 degrees C group versus control group (P < 0.05), but unchanged in 0 degrees C group.</p><p><b>CONCLUSION</b>The rat DMVECs injury severity are deteriorated with temperature decreasing, and VEGF might be involved in the regulation of membrane permeability in this period.</p>

The characteristics of vascular endothelial injuries induced by extreme environmental factors / 中国应用生理学杂志

Vascular endothelium plays an important role in regulating vascular homeostasis. Over the past years, it has become clear that endothelial dysfunction is a key event of pathophysiological changes in the initiation and progression of injuries induced by extreme environmental factors. The present review summarizes current understanding of vascular endothelial dysfunction induced by hypoxia, cold and heat, and provides the information for prevention and treatment of environmental exposure injuries.

The acclimatization to extreme environments and its physiological mechanisms / 中国应用生理学杂志

Acclimatization is a process of biological adaptation when exposed to environmental factors such as hypoxia, cold and heat for prolonged periods of time, where non-genetical variations play a role in allowing subjects to tolerate hypoxic, cold or hot environments. This review focuses on the characteristics and mechanisms of acclimatization found through major research advances by our institute. First, the mechanisms underlying the acclimatization to extreme environments are complex. In our investigations, the physiological changes of multiple systems including the nervous, circulatory, respiratory, and hemopoietic system were demonstrated when the acclimatization to hypoxia was developed, and the underlying significance of hypoxia-inducible factor-1 (HIF-1) was investigated. Second, it is suggested that the development of acclimatization to extreme environments is complicated. Hypoxia and cold coexist at high altitude. Our investigations revealed the characteristics of negative cross-relationship in the acclimatization to hypoxia and cold. And third, it is interesting for us to understand that acclimatization to extreme environments is transferable among individuals, and the characteristics of heat acclimatization-inducing factor (HAlF) were presented. The above findings will provide a theoretical guidance for protective operations and help to establish a solid foundation for future research related to acclimatization.

Effect of hypoxia on activation of the peripheral blood T lymphocyte in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the effect of hypoxia on the peripheral blood T lymphocyte subsets and co-stimulatory molecules in rats so as to provide the basis for studying the intervention measure.</p><p><b>METHODS</b>Before hypoxia and during hypoxia at 8 000 m for 8 h, 3 d, 6 d and 10 d the change of peripheral blood T lymphocyte subsets and co-stimulatory molecules in rats were detected by flowcytometer with three-color immunofluorescence label.</p><p><b>RESULTS</b>Rats were exposed to hypoxia at 8 000 m for 8 hours, and CD3+, CD8+, CD8+ CD28- lymphocyte percentages were significantly decreased (P < 0.01) compared with that before hypoxia. After 3 days of hypoxia, besides aforesaid change, CD4+ CD28+ lymphocyte percentage also prominently decreased (P < 0.01) and CD4+ CD28- prominently increased (P < 0.01). After 6 and 10 days of hypoxia, CD3+, CD4+ lymphocyte percentages were further decreased, while CD8+ CD28+ lymphocyte percentage significantly increased (P < 0.01).</p><p><b>CONCLUSION</b>After exposed to hypoxia at 8 000 m for 8 hours and 3 days, activation of CD8+ and CD4+ T lymphocyte was prominently decreased, while with the prolong of exposed time activation of CD8+ T lymphocyte was significantly increased.</p>

Study of hypoxia-induced immune injury and its intervention measure / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the characteristic of hypoxia-induced immune injury, its mechanisms and the intervention measure.</p><p><b>METHODS</b>The change of immune organ index, T lymphocyte subsets of peripheral blood and immune organ in mice during hypoxia were detected. Lymphocyte apoptosis of immune organ, pathology of lung and kidney in mice were observed. Then by way of prophylaxis we studied the effect of Chinese Traditional Medicine on hypoxia-induced immune injury in mice.</p><p><b>RESULTS</b>(1) Exposure to hypoxia at 8 000 m simulated altitude for 8 h resulted in marked decrease in CD4+ CD8+ thymocytes and marked increase in CD4+ CD8-, CD4- CD8+ thymocytes (P < 0.01). After 3 days of hypoxia, the mice had a much lower percentage of CD4+ T-cell (P < 0.05). The ratio of CD4+/CD8+ decreased significantly and aforesaid changes of thymocyte were further enlarged. Also mice had a pronounced increase in rates of late apoptosis or necrosis of spleen lymphocyte and thymocyte (P < 0.05). After 6 days of hypoxia, index of spleen was significantly increased (P < 0.05), index of thymus was significantly decreased (P < 0.05) and CD3+, CD4+, CD8+ lymphocyte percentage of spleen were significantly decreased (P < 0.01). Also late apoptosis or necrosis lymphocytes of spleen and thymus were further increased (P < 0.01), viable cell rates of spleen lymphocyte and thymocytes were markedly decreased (P < 0.01), early apoptosis rates of spleen lymphocyte were markedly increased (P < 0.01). There was no significant change in the percentage of CD8+ lymphocyte in peripheral blood during the whole hypoxia period. (2) New Compound Codonopsis Pilosula (NCCP), Xiang Qi Polysaccharide (XQP) and NCCP + XQP could significantly increase the number of peripheral blood CD3+, CD4+ and spleen CD4+, but had no significant influence on the number of spleen CD8+. XQP and XQP+ NCCP could significantly decrease the number of CD4+ CD8+ (P < 0.01), increase that of CD4+ CD8- (P < 0.01), and had no significant influence on CD4- CD8+ in thymus. However, NCCP didn't influence the component of thymocytes.</p><p><b>CONCLUSION</b>After hypoxia at 8 000 m simulated altitude decrease of lymphocyte of periphery in mice may be related with increase of apoptosis and necrosis of lymphocyte, and with increase of distribution of lymphocyte to lung in early period of exposure. NCCP and XQP have hopeful prospect in intervention study of hypoxia-induced immune injury.</p>

Protective effects of new compound codonopsis tablets against acute mountain sickness / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study on the protective effects of new compound codonopsis tablets against acute mountain sickness (AMS).</p><p><b>METHODS</b>Forty-five male plain resident soldiers stayed at 1400 m altitude for 3 months were randomly divided into two groups, control (15 men) and treatment group (30 men). Single blind trial was used in this study. The subjects in the two groups took placebo and new compound codonopsis tablets respectively for 5 days before climbing to high mountain, and continued to take for another 10 days until the 3rd day after arriving at 5200 m altitude. On the 1st , 3rd, and 5th day after they arrived at 5200 m altitude, the score and the degree of AMS symptoms of soldiers were followed up and recorded according to State Military Standard GJB1098-91--"Principles of diagnosis and treatment of benign form of acute mountain sickness", heart rate (beats/min) and arterial oxygen saturation (%) were detenrmined. On the 6th day after they arrived at high altitude, forced vital capacity(FVC), forced expired volume in one second(FEV1.0), FEV1% (FEV1.0/FVC), FEF25%-75%, peak expiratory flow (PEF) and maximal voluntary ventilation (MVV) were detected, total frequency of hands cross movement and memory of order numbers test were measured.</p><p><b>RESULTS</b>Comparison with control, AMS symptoms of treatment group reduced on the 1st, 3rd, and 5th day after arriving at 5200 m high altitude (P < 0.01). The degree of AMS symptoms of treatment group was significantly different from that of control. The proportion of slight symptoms in treatment group was high, and that of relative serious symptoms in control was high. Compared with control, FVC, FEV1.0, FEF25%-75%, PEF and MVV of treatment group increased (P < 0.05, P < 0.01), and Ttis, Ctis of treatment group increased (P < 0.05, P < 0.01), Atime decreased markedly (P < 0.05), there was no statistically significant difference in Etis and Sum between the two groups.</p><p><b>CONCLUSION</b>New compound codonopsis tablets could decrease the incidence of AMS, mitigate the symptoms of AMS, and improve breathing function and fingers movement function. New compound codonopsis tablets have an obvious effect on prevention and treatment of acute mountain sickness.</p>

Effects of shivering on airway rewarming / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effects of shivering on airway rewarming.</p><p><b>METHODS</b>The hypothermic dog model without shivering was established by immersing an anesthetized dog in cold water and administering atracurium to inhibit the dog shivering. The model dog respired warm fully humidified (40-45 degrees C, RH 99.9%) air and room temperature air(19 +/- 1 degrees C, RH 30% - 75%) to rewarm each for 2 hours, the priority of different temperature air respired was arranged randomly. After rewarming for 4 hours, the relaxed dog breathed warm humidified air by positive pressure ventilation in order to restore its spontaneous respiratory. Then the dog continued to respire warm humidified air spontaneously until the esophageal (Te) and rectal temperature (Tr) of the dog achieved the same degrees as the dog was immersed in the water. The metabolic heat production was detected by indirect calorimetry during the experiment.</p><p><b>RESULTS</b>(1) When the shivering was inhibited, inhaling warm humidified air for 2 hours made the Tr and Te of the dogs increase 0.26-0.39 degrees C and 0.44-1.11 degrees C per hour respectively, inhaling air at room temperature for 2 hours made Tr and Te of the dogs decrease 0.24-0.51 degrees C and 0.58-0.67 degrees C per hour, respectively. And the changes in Tr and Te of the dogs were unrelated to the priority of inhaling air at different temperature. (2) When the dog with shivering respired spontaneously warm humidified air, the rewarming rates of Tr and Te were 2.26-2.33 degrees C/h and 1.96-2.38 degrees C/h respectively, quicker than those of the dogs whose shivering was inhibited. (3) Compared with metabolic heat production of the unshivering dog respiring warm humidified air by positive pressure ventilation, that of the shivering dog respiring warm humidified air spontaneously increased outstandingly, shivering thermogenesis made the rewarming rates increased obviously.</p><p><b>CONCLUSION</b>Airway rewarming is a method conducive to rewarming of hypothermia. When the body is shivering, the metabolic heat production increases obviously, that makes the rewarming rate increase markedly. So the shivering must be inhibited in order to eliminate the interference of shivering thermogenesis when the effects of airway rewarming are detected.</p>

Observation on therapeutic effect of Hwato never and muscle stimulator on peripheral facial paralysis / 中国针灸

<p><b>OBJECTIVE</b>To observe the therapeutic effect of Hwato never and muscle stimulator on peripheral facial paralysis.</p><p><b>METHODS</b>Eighty-seven cases of peripheral facial paralysis were randomly divided into a Hwato never and muscle stimulator observation group (n=44) and a G 6805 electronic stimulator control group (n=43). The same acupoints, Hegu (LI 4), Sanyinjiao (SP 6), Taichong (LR 3) and local acupoints on the affected side were selected in the two groups. The therapeutic effects were compared between the two groups.</p><p><b>RESULTS</b>Although the total effective rates were both 100.0% in the two groups, the cured rate was 90.9% in the observation group and 62.8% in the control group with a significant difference between the two groups (P < 0.05). There were no adverse effects in the two groups.</p><p><b>CONCLUSION</b>The cured rate of Hwato never and muscle stimulator on peripheral facial paralysis is superior to that of G 6805 electronic stimulator.</p>

Effects of lactate on cell injury in primary cultures of rat cortical neurons during hypoxia/reoxygenation / 中国应用生理学杂志

<p><b>AIM</b>To explore the effects of different concentrations of lactate on neuronal injury during hypoxia/reoxygenation (H/R) and its mechanism.</p><p><b>METHODS</b>Different concentrations of lactate (0, 0.5, 1.0, 2.0, 5.0 mmol/L) were added into medium after different duration of hypoxia, then reoxygenation for 24 h, cell survival rate and LDH release were assayed to determine neuronal damage, moreover, equal concentration of hydrochloric acid were used to mimic the changes of pH brought by lactate for investigating the mechanism of the effects of lactate on neuronal H/R injury.</p><p><b>RESULTS</b>Under normoxia and H/R 5.0 mmol/L lactate and hydrochloric acid induced or exacerbated neuronal injury. After 12 h and 24 h hypoxia exposure 1.0 mmol/L lactate was shown to be protective, 1.0 mmol/L hydrochloric acid had no effect on neuronal H/R damage.</p><p><b>CONCLUSION</b>Lactate of lower concentration was demonstrated to be neuroprotective during H/R, this protective effect was shown to be due to lactate anions. In contrast, higher concentration of lactate could induce or aggravate neuronal damage under normoxia and H/R, perhaps via the mechanism which involved the changes of pH.</p>

Study on effect of electroacupuncture at Hegu (LI 4) on the uterotonic time in parturients of uterus inertia / 中国针灸

<p><b>OBJECTIVE</b>To evaluate the therapeutic effect and applying value of Hegu (LI 4) for inertia of uterus.</p><p><b>METHODS</b>In three centers, 276 cases enrolled were randomly assigned to a western medicine group and an acupuncture and western medicine group. The western medicine group were treated with intravenous drip of oxytocin, and the acupuncture and western medicine group were treated with electroacupuncture at Hego (LI 4) and intravenous drip of oxytocin. Changes of inertia of uterus and duration and interval of uterine contraction were investigated in the two groups.</p><p><b>RESULTS</b>The total effective rate was 97.1% in the acupuncture group, and 70.3% in the western medicine group with a very significant difference between the two groups (P < 0. 01). There was a significant difference in the duration and the interval of uterine contraction between the two groups (P < 0.1, P < 0.05).</p><p><b>CONCLUSION</b>Elecoroacupuncture at Hego (LI 4) can be adopted for treatment of dystocia due to abnormality of force of labor.</p>

Establishment of a hypothermic dog model to investigate airway rewarming / 中国应用生理学杂志

<p><b>AIM</b>In order to study airway rewarming method and rewarming devices for hypothermia, hypothermic dog model was established.</p><p><b>METHODS</b>The anesthetized dog was immersed in cold water at 16.7 degrees C until the esophageal temperature (Te) of the dog decreased to 34.0 degrees C, the core temperature and skin temperature were monitored by using a 12-channel scanning thermometers. Atracurium besylate, a skeletal muscle relaxant, was injected intravenously when the core temperature of the dog was basically steady after the dog was out of the cold water, the hypothermic dog model was established.</p><p><b>RESULTS</b>Rectal and esophageal temperature could stand for the core temperature of the hypothermic dog model, but mixing with each other was prohibited because of leading to mistakes. Administering of atracurium besylate could eliminate the effect of shivering on airway rewarming alone, hypothermic dog model in which shivering was inhibited could be used in determination of airway rewarming technique and rewarming devices for hypothermia.</p><p><b>CONCLUSION</b>Hypothermic dog model in which shivering was inhibited can abolish the interference of shivering, experimental repeatability is good, experimental method quite simple, and the model appropriate for application and dissemination.</p>

Immune complex may play an important role in freezing injury of frostbite rats / 中国应用生理学杂志

<p><b>AIM</b>To explore the role of humoral immunity in the pathophysiological process of freezing injury and the possible immune interference in the preventation and treatment of frostbite.</p><p><b>METHODS</b>Severe experimental freezing injury model was made in Wistar rats( n = 20). The concentration of three types of immunoglobulin (IgG, IgA and IgM), two types of complement components (C3 and C4), and circulating immune complex (CIC) were measured respectively before and at 4h, 1d, 3d, and 5d after frostbite. At the same time, the tissue immune complex (TIC) in skeletal muscle and the contents of the red blood cell immune complex (RBC-IC) were also observed and then was the red blood cell immune adherence activity (RCIA).</p><p><b>RESULTS</b>Serum IgG concentration decreased rapidly to the lowest level at 4 h after frostbite IgA concentration dropped to the nadir on 1 day after freezing. Decreases of both immunoglobulins were maintained during the 5 days after frostbite. The fate of both C3 and C4 were the same as those immunoglobulins. Freezing had rather less effect on IgM level. CIC concentration in serum, expressed as the percent of prefreezing increased rapidly and to the zenith on the 3 days post-freezing. By immunofluorescence microscopy, thin continuous linear pattern (IgG) was demonstrated along the SM on the first day post-freezing. Granular and nodular deposits (IgG) appeared along the SM as the time proceeded after frostbite. RBC-IC contents, expressed as the erythrocyte IC rosette rate, increased significantly and to the zenith on the 3 d post-freezing, while RCIA depressed to the nadir at the same time.</p><p><b>CONCLUSION</b>The freezing frostbite is an immune complex related disease which have not been reported by others before.</p>

Role of cellular adhesion molecule ICAM-1 in freezing/thawing injury of vascular endothelial cells / 中国应用生理学杂志

<p><b>AIM</b>To investigate the role of ICAM-1 on the surface of vascular endothelial cell (VEC) in freezing/thawing injury of VEC, in order to elucidate the pathogenesis of freezing/thawing injury.</p><p><b>METHODS</b>VEC separated and cultured from rat aorta and PMN separated from rat peripheral blood were selected as experiment materials. The frozen/thawed VEC model was founded by freezing VEC with the type WKL-V rate cooling instrument and then rewarming them in a water bath. ICAM-1 expression on the surface of frozen/thawed VEC was detected at 4, 12 and 24 h after freezing/thawing with immunohistochemical method. After coincubating frozen/thawed VEC with normal PMN, the adhesion of VEC to PMN was monitored with rose bengal staining assay and the injury level of VEC was indicated by measuring LDH activity in nutrient solution.</p><p><b>RESULTS</b>The ICAM-1 expression on the surface of VEC increased from 13.2% +/- 3.6% before freezing/thawing of VEC to 22.3% +/- 4.4% at 4 hour after freezing/thawing, and reached the peak (37.9% +/- 2.5%) at 12 hour after freezing/thawing of VEC. After coincubation of frozen/thawed VEC with normal PMN, the adherence of frozen/thawed VEC to PMN increased from group control 0.204 +/- 0.025 to 0.363 +/- 0.022 (P < 0.01), LDH activity in nutrient solution increased from group control 104.64 +/- 20.14 U/L to 162.33 +/- 27.88 U/L (P < 0.01), monoclonal antibody against ICAM-1 (ICAM-1 Mab) could partially block the adherence of frozen/thawed VEC to PMN (0.270 +/- 0.021, P < 0.01), and diminish LDH activity in nutrient solution (125.39 +/- 22.26 U/L, P < 0.05).</p><p><b>CONCLUSION</b>The freezing/thawing of VEC can elicit an increase in ICAM-1 expression on the surface of VEC, and then proceed to VEC-PMN adherence and lead to VEC injury.</p>

Application of Cytological Examination of Cerebrospinal Fluid in Diag nosis of Central Nervous System Leukemia / 实用儿科临床杂志

Objective To investigate the diagnosis value of the cytological examination of the cerebrospinal fluid of central nervous system leukemia.Methods Adopting cell smear centrifugal machine to collect the cerebrospinal fluid cells,the cells were stained and examinated under the microscope.Results Fifty-nine children with different type of leukemia had been examinated by 438 times by cerebrospinal fluid.The positive rates of the cases and samples were 15.3% and 8.7%,respectively.Conclusion The cytological examination of cerebrospinal fluid is especially valuable for the early diagnosis ,therapy and relapse of central nervous system leukemia of monitoring.

Hygienic characteristic evaluation of an anti-immersion trousers dressed by soldiers during fighting a flood and relieving victims of a disaster I Test on land / 医疗卫生装备

In order to investigate the hygienic characteristic of anti-immersion trousers, ten male soldiers dressed in the trousers or in camouflage trousers were subjected to exercise test and sedentary test respectively at room temperature of 17?2℃. In the test, eleven parameters such as core temperature, skin temperature, heat flow and so on were observed. The results indicated that in sedentary tests, the low limb heat flow of the subjects dressed in anti-immersion trousers was larger than that dressed in camouflage trousers; the heat insulation value of anti-immersion trousers was smaller than that of camouflage trousers; and for the other parameters, there was no evident difference between the two group. It suggested that when used on land, hygiene characteristic and effect on body heat balance of the anti-immersion trousers were similar to those of camouflage trousers.

The role of LFA-1 in the vascular endothelial cells injury mediated by frozen/thawed neutrophils / 中国应用生理学杂志

<p><b>AIM</b>To investigate the mechanism of the vascular endothelial cell (VEC) injury caused by freezing/thawing.</p><p><b>METHODS</b>The frozen/thawed neutrophil (PMN) model was founded by freezing PMNs with a rate cooling instrument and then rewarming them in a water bath, the PMNs used here were separated from rat's peripheral blood using density gradients centrifugation techniques. The expression of LFA-1 on the surface of frozen/thawed PMNs was observed at 4 h,12 h and 24 h after freezing/thawing. After co-incubating untreated VECs with frozen/thawed PMNs, we detected the VEC injury and the changes in PMN-VEC adhesion.</p><p><b>RESULTS</b>(1) The PMNs LFA-1 expression increased in a time-dependent manner within 24 h after the freezing/thawing of PMNs. (2) After co-incubating untreated VECs with frozen/thawed PMNs, the adhesion between frozen/thawed PMNs and VECs increased and VEC injury occurred. (3) Monoclonal antibody against LFA-1 could block the PMN-VEC adhesion and subsequently attenuated the VEC injury.</p><p><b>CONCLUSION</b>The freezing/thawing of PMNs can elicited an increase in PMN LFA-1 expression and trigger the PMN-VEC adhesion and subsequently bring about the VEC injury.</p>