Process Optimization of Dual-Liquid Casting and Interfacial Strength-Toughness of the Produced LAS/HCCI Bimetal.

The pouring time interval is the decisive factor of dual-liquid casting for bimetallic productions. Traditionally, the pouring time interval is fully determined by the operator's experience and on-site observation. Thus, the quality of bimetallic castings is unstable. In this work, the pouring time interval of dual-liquid casting for producing low alloy steel/high chromium cast iron (LAS/HCCI) bimetallic hammerheads is optimized via theoretical simulation and experimental verification. The relevancies of interfacial width and bonding strength to pouring time interval are, respectively, established. The results of bonding stress and interfacial microstructure indicate that 40 s is the optimum pouring time interval. The effects of interfacial protective agent on interfacial strength-toughness are also investigated. The addition of the interfacial protective agent yields an increase of 41.5% in interfacial bonding strength and 15.6% in toughness. The optimum dual-liquid casting process is used to produce LAS/HCCI bimetallic hammerheads. Samples cut from these hammerheads show excellent strength-toughness (1188 Mpa for bonding strength and 17 J/cm2 for toughness). The findings could be a reference for dual-liquid casting technology. They are also helpful for understanding the formation theory of the bimetal interface.

Synaptic development of layer V pyramidal neurons in the prenatal human prefrontal neocortex: a Neurolucida-aided Golgi study.

The prefrontal neocortex is involved in many high cognitive functions in humans. Deficits in neuronal and neurocircuitry development in this part of the cerebrum have been associated with various neuropsychiatric disorders in adolescents and adults. There are currently little available data regarding prenatal dendrite and spine formation on projecting neurons in the human prefrontal neocortex. Previous studies have demonstrated that Golgi silver staining can identify neurons in the frontal lobe and visual cortex in human embryos. In the present study, five fetal brains, at 19, 20, 26, 35, and 38 gestational weeks, were obtained via the body donation program at Xiangya School of Medicine, Central South University, China. Golgi-stained pyramidal neurons in layer V of Brodmann area 46 in fetuses were quantitatively analyzed using the Neurolucida morphometry system. Results revealed that somal size, total dendritic length, and branching points of these neurons increased from 26 to 38 gestational weeks. There was also a large increase in dendritic spines from 35 to 38 gestational weeks. These findings indicate that, in the human prefrontal neocortex, dendritic growth in layer V pyramidal neurons occurs rapidly during the third trimester of gestation. The use of human fetal brain tissue was approved by the Animal Ethics Committee of Xiangya School of Medicine, Central South University, China (approval No. 2011-045) on April 5, 2011.

[Plasma gelsolin level and its relationship with the prognosis of patients with severe burns].

OBJECTIVE: To observe the changes in plasma gelsolin (pGSN) level of patients with severe burn and to explore its relationship with sepsis and death of patients. METHODS: One hundred and two patients with total burn area equal to or larger than 30% TBSA hospitalized from May 2010 to May 2012 were included as burn group. Twenty-five healthy volunteers were recruited as healthy control group. Peripheral venous blood of patients was harvested on post burn day (PBD) 1, 3, 7, 14, and 21 to determine the pGSN level with double antibody sandwich ELISA kits, and the same maneuver was carried out in healthy volunteers. (1) Patients in burn group were divided into three groups by burn size: small burn area group (30% - 49% TBSA, n = 39), medium burn area group (larger than 49% and smaller than or equal to 69% TBSA, n = 33), and large burn area group (larger than 69% and smaller than or equal to 99% TBSA, n = 30). (2) According to diagnostic criteria of burn sepsis, patients in burn group were divided into sepsis group (n = 43) and non-sepsis group (n = 59). (3) According to the prognosis of patients with sepsis, patients in sepsis group were further divided into non-survival sepsis group (n = 14) and survival sepsis group (n = 29). The levels of pGSN in above groups were compared, and their relationship with sepsis and death of patients was analyzed. Data were analyzed with analysis of variance, LSD test and one-way Logistic regressions. RESULTS: (1) Levels of pGSN in burn group were obviously lower than those of healthy control group on PBD 1, 3, 7, 14, and 21 (with F values respectively 140.01, 369.52, 702.15, 360.14, 84.16, P values all below 0.01). (2) The mean levels of pGSN in large, medium, and small burn area groups at five time points were (43 ± 11), (85 ± 23), (124 ± 38) mg/L, showing statistically significant differences among them (F = 367.76, P < 0.01), and they were all lower than that of healthy control group [(326 ± 51) mg/L, P values all below 0.01]. (3) The mean levels of pGSN in sepsis group and non-sepsis group at the five time points were (77 ± 12), (122 ± 38) mg/L. Levels of pGSN in sepsis group were lower than those in non-sepsis group on PBD 3, 7, 14, and 21 (with F values respectively 30.35, 111.59, 209.36, 422.76, P values all below 0.01). (4) The mean levels of pGSN in non-survival sepsis group and survival sepsis group at the five time points were (53 ± 8) and (103 ± 25) mg/L. Levels of pGSN in non-survival sepsis group were lower than those in survival sepsis group on PBD 1, 3, 7, 14, and 21 (with F values respectively 9.05, 18.48, 41.34, 107.11, 180.48, P values all below 0.01). (5) Logistic regression analysis showed that the level of pGSN is the independent risk factor related to the complication of sepsis (odds ratio: 5.44, 95% confidence interval: 2.35 - 12.74, P < 0.01) and death (odds ratio: 5.52, 95% confidence interval: 2.34 - 12.19, P < 0.01) in burn patients. CONCLUSIONS: Severe burn injury could down-regulate the pGSN level of patients, and it decreases along with the increase in the area and severity of burn trauma. pGSN level appears to be an early prognostic marker for patients suffering from severe burns.

[Epidemiological studies on close contacts of smear-positive tuberculosis patients in Shijiazhuang city from 2007 to 2008].

OBJECTIVE: To analyze the incidence of tuberculosis (TB) in people who were in close contact with smear-positive TB patients. METHODS: A total of 19 159 subjects, including 17 334 family members and 1825 classmates of patients, in close contact with 6653 smear-positive TB patients in Shijiazhuang city from 2007 to 2008 were observed. All the classmates were tested by purified protein derivative (PPD) test and symptom screening, and all family members were screened by symptoms. All these subjects were trained with knowledge related to TB. The ones with positive PPD test and suspected TB symptoms were further examined by chest X-ray and sputum smear microscopy, and those without any symptom were followed up monthly throughout a two year period and were examined at any time if symptoms occurred. RESULTS: A total of 281 patients with pulmonary TB were diagnosed in 2 years, including 176 family members and 105 classmates in all close contacts. The smear-positive incidences were 1466.67/100 000. The incidences for 14 - 25 years old group and more than 75 years old group were 2907.18/100 000 (83/2855) and 2650.96/100 000 (18/679), which were higher than those for other groups. Two higher incidences were related to close contact time periods of 6 months (929.07/100 000, 178/19 159) and 13 - 18 months (369.12/100 000, 70/18 964). Three highest incidences were observed in the roommates (11 384.62/100 000, 37/325), classmates (4533.33/100 000, 68/1500) and couples (1624.17/100 000, 86/5295). CONCLUSION: Closer contact with smear-positive patients with TB may result in the higher chance of TB. Close contact for 6 months or 13 to 18 months caused more patients, and the 14 - 25 years old group and more than 75 years old group had higher incidences of TB.

Reduction of plasma gelsolin levels correlates with development of multiple organ dysfunction syndrome and fatal outcome in burn patients.

BACKGROUND: Depletion of the circulating actin-binding protein, plasma gelsolin (pGSN) has been described in critically ill surgical patients. We hypothesized that the extent of pGSN reduction might correlate with different outcome of burn patients. The study was performed to evaluate the prognostic implications of pGSN levels on the development of multiple organ dysfunction syndrome (MODS) and fatal outcome in a group of severely burn patients. METHODS AND FINDINGS: 95 patients were included, and they were divided into three groups with different burn area: group I (n = 33), group II (n = 32) and group III (n = 30). According to whether there was development of MODS or not, patients were divided into MODS group (n = 28) and none-MODS group (n = 67); then the patients with MODS were further divided into non-survivor group (n = 17) and survivor group (n = 11). The peripheral blood samples were collected on postburn days (PBD) 1, 3, 7, 14, and 21. The levels of pGSN were determined and T cells were procured from the blood. The contents of cytokines (IL-2, IL-4 and IFN-γ) released by T cells were also measured. The related factors of prognosis were analyzed by using multivariate logistic regression analysis. The results showed that pGSN concentrations, as well as the levels of IL-2 and IFN-γ, decreased markedly on PBD 1-21, whereas, the levels of IL-4 increased markedly in all burn groups as compared with normal controls (P<0.05 or P<0.01), and there were obviously differences between group I and group III (P<0.05 or P<0.01). The similar results were found in MODS patients and the non-survivor group as compared with those without MODS and the survival group on days 3-21 postburn (P<0.05 or P<0.01). Moreover, as the pGSN levels decreased, the incidence of septic complication as well as MODS remarkably increased. CONCLUSIONS: pGSN levels appear to be an early prognostic marker in patients suffering from major burns.

Association of high mobility group box-1 protein levels with sepsis and outcome of severely burned patients.

BACKGROUND: The study was performed to observe the systemic release and kinetics of high mobility group box-1 protein (HMGB1) in burned patients. METHODS: 106 patients were included, and they were divided into three groups with different burn sizes: group I, group II and group III. Healthy volunteers served as normal controls (n=25). The peripheral blood samples were collected on postburn days (PBD) 1, 3, 7, 14, and 21. The blood samples were used to detect levels of HMGB1 in plasma by ELISA kits for human. Gene expression of HMGB1 in peripheral blood mononuclear cells was assessed by real-time quantitative PCR taking GAPDH as the internal standard. RESULTS: The levels of HMGB1 were significantly elevated on PBD 1-21 in patients with various burn sizes compared with normal controls, and there were obvious differences between group I and group III. The HMGB1 levels were significantly higher in septic patients than those without sepsis on PBD 7-21. Among septic patients, the HMGB1 levels in the survival group were markedly lower than those with fatal outcome on PBD 3-21. CONCLUSIONS: Extensive burn injury could result in significantly increased HMGB1 levels, which appears to be associated with the development of sepsis and fatal outcome of major burns.

[Influence of CD14 gene polymorphism on the expression of high mobility group box-1 protein in patients with severe burn].

OBJECTIVE: To investigate the influence of the lipopolysaccharide receptor CD14-159C/T gene polymorphism on the synthesis and release of high mobility group box-1 protein (HMGB1), and its relation to sepsis in patients with severe burn. METHODS: Venous blood from 35 patients with burn area equal to or larger than 30% TBSA was obtained on post burn day (PBD) 1, 3, 5, 7, 14, 21, and 28 respectively. Eleven volunteers were enrolled as healthy control group (HC).CD14-159C/T gene polymorphism was detected with polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis. Plasma level of HMGB1 was determined with ELISA. Leukocyte HMGB1 mRNA expression was determined with RT-PCR. Data were processed with chi(2) test, analysis of variance, and t test. RESULTS: Among the C-159T genotype of CD14 gene in the 35 patients, the distribution frequency of the T and the C allele was respectively 57.2% and 42.8%. Seven cases (20.0%) were homozygous for the C allele (CC), 16 cases (45.7%) were heterozygous (TC), and 12 cases (34.3%) were homozygous for the T allele (TT). Allele and genotype frequencies in cases were testified as reaching the Hard-Weinberg equilibrium. The incidence of sepsis was markedly lower in CC homozygous patients than in TC heterozygous and TT homozygous patients. Only one of the 3 septic patients in CC homozygous type died; 4 of 9 septic cases in TC heterozygous type and 4 of 7 septic cases in TT homozygous type died. Plasma levels of HMGB1 of patients were significantly elevated early on PBD 1 as compared with HC group, and higher values were found in TC heterozygous and TT homozygous patients than that in CC homozygous patients on PBD 14, 21, 28 (with F value respectively 3.5671, 4.2035, 3.8529, P < 0.05 or P < 0.01). Higher HMGB1 mRNA expression was found in septic patients as compared with non-sepsis patients on PBD 14 (1.5 +/- 0.5 vs. 1.2 +/- 0.4, t = -2.205, P < 0.05). Plasma level of HMGB1 was also respectively higher in septic patients than in non-sepsis patients on PBD 7, 21 [(44 +/- 29) ng/mL vs. (26 +/- 12) ng/mL, t = -2.355, P < 0.05; (25 +/- 15) ng/mL vs. (10 +/- 6) ng/mL, t = -3.872, P < 0.01)]. CONCLUSIONS: CD14C-159T gene polymorphism might markedly influence the synthesis and release of HMGB1, and it is associated with increase in susceptibility of sepsis in patients with severe burn.

Synthesis, structure, DNA-binding properties, and cytotoxicity of ruthenium(II) polypyridyl complexes.

Many ruthenium(II) complexes show high antitumor activities, and the in vitro antitumor activities are usually related to DNA binding. We designed and synthesized two Ru(II) polypyridyl complexes, [Ru(dmp)2(fpp)]2+ (dmp=2,9-dimethyl-1,10-phenanthroline; fpp=2-[3,4-(difluoromethylenedioxy)phenyl]imidazo[4,5-f] [1,10]phenanthroline and [Ru(phen)(2)(fpp)]2+ (phen=1,10-phenanthroline). The DNA-binding properties of these complexes have been investigated by spectroscopic titration, DNA melting experiments, viscosity measurements, and photoactivated cleavage. The mechanism studies of photocleavage revealed that singlet oxygen (1O2) and superoxide anion radical (O2(.-)) may play an important role in the photocleavage. The cytotoxicity of complexes 1 and 2 have been evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) method; complex 2 shows slightly higher anticancer potency than 1 does against all the cell lines screened.

In vitro cytotoxicity, apoptosis, DNA-binding, and antioxidant activity studies of ruthenium (II) complexes.

Two new ligands maip (1) (maip = 2-(3-aminophenyl)imizado[4,5-f][1,10]phenanthroline), paip (2) (paip = 2-(4-aminophenyl)imidazo[4,5-f][1,10]phenanthroline), and their ruthenium (II) complexes [Ru(phen)(2)(maip)](ClO(4))(2) (3) and [Ru(phen)(2)(paip)](ClO(4))(2) (4) (phen = 1,10-phenanthroline) have been synthesized and characterized. The cytotoxicity of these compounds was evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The apoptosis assay was carried out with acridine orange/ethidium bromide staining methods. The DNA-binding behaviors of complexes 3 and 4 were investigated by viscosity measurements, thermal denaturation, photocleavage, and spectroscopic methods. The results show that the two complexes intercalate into the base pairs of DNA. In the presence of a complex, apoptosis of BEL-7402 cells was observed. Experiments show that these compounds exhibit antioxidant activity against hydroxyl radicals.

Association between regulatory T cell activity and sepsis and outcome of severely burned patients: a prospective, observational study.

INTRODUCTION: To investigate the significance of changes in regulatory T cells (Tregs) activity and its relationship with sepsis, as well as outcome of patients with major burns. METHODS: The periphery blood samples of 106 patients were collected on post-burn days 1, 3, 7, 14, and 21. Tregs were isolated and their phenotypes (cytotoxic T-lymphocyte-associated antigen 4 and forkhead/winged helix transcription factor p3) were analyzed by flow cytometry, and the contents of cytokines (interleukin-10 and transforming growth factor-beta1) released into supernatants by Tregs were also determined by enzyme-linked immunosorbent assay kits. Gene expressions of cytokines were assessed by real-time quantitative polymerase chain reaction. RESULTS: Expressions of Tregs phenotypes and gene/protein expression of cytokines were all elevated after burn, and there were obvious differences among patients with various burn sizes. They were also higher in septic patients than those without sepsis. Among septic patients, the expressions of Tregs phenotypes and the levels of cytokines were markedly lower in the survival group than those in patients with fatal outcome. CONCLUSIONS: Severe burn injury per se could lead to the changes in Tregs activities. Elevated levels of cytokines produced by Tregs and activation markers on Tregs surface might play an important role in the pathogenesis of sepsis and mortality in burned patients.

Synthesis, DNA-binding, photocleavage, cytotoxicity and antioxidant activity of ruthenium (II) polypyridyl complexes.

Two new ligands maip (1a), paip (1b) with their ruthenium (II) complexes [Ru(bpy)(2)(maip)](ClO(4))(2) (2a) and [Ru(bpy)(2)(paip)](ClO(4))(2) (2b) have been synthesized and characterized. The results show that complexes 2a and 2b interact with DNA through intercalative mode. The cytotoxicity of these compounds has been evaluated by MTT assay. The experiments on antioxidant activity show that these compounds exhibit good antioxidant activity against hydroxyl radical (OH).

[Study on the correlation between CD14 gene polymorphism and T cell-mediated immunity in severely burned patients].

OBJECTIVE: To investigate the correlation between CD14 gene polymorphism and T cell-mediated immunity in severely burned patients. METHODS: The blood samples of 77 patients with extensive burn injury (> 30% total body surface area) were collected, and CD14-159C/T gene polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). T lymphocyte cell proliferation and interleukin-2 (IL-2) production were determined, and the ratio of CD4(+)/CD8(+) T lymphocyte as well as apoptosis of CD4(+) T lymphocyte was examined by flow cytometry. RESULTS: The ability of T lymphocyte proliferation was obviously decreased in severely burned patients. Compared with CC homozygote patients, proliferative activity of T lymphocyte to mitogen stimulation was significantly depressed in TT and TC patients on post burn days 5, 21, and 28 (P < 0.05 or P < 0.01). IL-2 production in TT, TC patients was constantly in low level after burns, while it was increased from post burn day 14 in CC patients. The ratio of CD4(+)/CD8(+) T lymphocytes was markedly decreased in TC, TT patients than that in CC patients, especially on post burn days 1, 3, 14, 21, and 28 (P < 0.05 or P < 0.01). Meanwhile, compared with CC homozygote patients, the apoptosis rates of CD3(+)CD4(+) T lymphocytes were much higher in TT patients on post burn days 5, 7, and 21 (P < 0.05), and in TC patients on days 7, 14 (P < 0.05), respectively. However, no obvious differences in parameters of immune function of T lymphocytes were found between TT and TC patients (P > 0.05). CONCLUSION: CD14-159C/T polymorphism could influence the T cell-mediated immunity in extensively burned patients, which might participate in the development of septic complications secondary to major burns.

Poly[[aqua-bis(µ(3)-isonicotinato-κO:O':N)tris-(µ(2)-isonicotinato-κO,O':N)(nitrato-κO)bis-(µ(4)-oxalato-κO,O:O:O,O:O)dierbium(III)tetra-silver(I)] tetra-hydrate].

In the title coordination polymer, {[Ag(4)Er(2)(C(6)H(4)NO(2))(5)(C(2)O(4))(2)(NO(3))(H(2)O)]·4H(2)O}(n), each Er(III) atom is coordinated in a bicapped trigonal-prismatic coordination geometry by three O atoms from two isonicotinate (IN) ligands, four O atoms from two oxalate ligands and one O atom from either a nitrate ion or a water mol-ecule, both of which are half-occupied over the same site. One Ag(I) atom has a Y-shaped geometry defined by one N atom from one IN ligand, one O atom from another IN ligand and one O atom from an oxalate ligand. The other Ag(I) atom is coordinated by two IN ligands and one O atom from an oxalate ligand. One of the IN ligands is disordered over an inversion center and forms a bridge between two centrosymmetric Ag(I) ions. Due to the disorder, this IN ligand coordinates to the Ag atom through either the pyridyl N or the carboxyl-ate O atoms. The IN and oxalate ligands link the Er and Ag atoms into a three-dimensional coordination framework. O-H⋯O and C-H⋯O hydrogen bonds are observed in the crystal structure.

[Repair of occipital and nuchal wounds with inferior trapezius myocutaneous flaps in patients after high voltage electrical burn].

OBJECTIVE: To explore the methods and effects of repair of occipital and nuchal wounds with inferior trapezius myocutaneous flap after deep electrical bum. METHODS: Twelve patients with high-voltage electrical burn in occipital and nuchal regions were hospitalized to our ward from March 2003 to September 2007. They were repaired with improved inferior trapezius myocutaneous flaps after debridement. Flaps were of two types: (1) blood supply from cutaneous and perforator branches of the original segment of the superficial descending branch of transverse cervical artery. (2) combined blood supply from both superficial and deep descending branches of transverse cervical artery C, i.e., dorsal scapular artery). All flaps carried segmental and limited trapezius muscle cuff surrounding the vascular pedicle of the flap similar to a perforator flap. RESULTS: Flaps survived completely primarily in eight cases. In two patients, infection developed in flaps adjacent to wounds with lignification; they healed after dress change. Necrosis appeared in distal end of flap (one case), it healed after re-operation. One patient with surviving flaps died of sepsis and multiple organ failure 21 days after operation. The flaps which survived were not swollen ; the donor sites at scapular region looked normal without pterygoid or pendulous scapula deformities. CONCLUSION: Inferior trapezius myocutaneous flaps can be used to repair occipital and nuchal wounds, with the advantages of constant blood vessels, reliable blood supply, convenience for application.

[Change in T cell-mediated immunity and its relationship with high mobility group box-1 protein levels in extensively burned patients].

OBJECTIVE: To investigate the change in T cell-mediated immunity and its relationship with plasma high mobility group box-1 protein (HMGB1) levels in severely burned patients. METHODS: Thirty-five extensively burned patients (> 30% total body surface area) were included in this study, and were divided into MODS group (n = 13) and non-MODS group (n = 22). The blood samples were collected on post burn days 1, 3, 5, 7, 14, 21 and 28. The plasma levels of HMGB1 were measured by using ELISA, and T lymphocyte proliferation response and its IL-2 production ability in peripheral blood were determined too. In addition, the ratio of CD4+/CD8+ T cells were detected by using flow cytometry. RESULTS: Plasma HMGB1 levels were markedly elevated on post burn day 1 in severely burned patients, and HMGB1 level was significantly higher in MODS group than in non-MODS group (P < 0.05). Lymph proliferation response and IL-2 production of T cells in peripheral blood, and the ratio of CD4+/CD8+ T cells in MODS group were markedly lower than those in non-MODS group on post burn days 1, 14, 21 and 28 (all P < 0.05). It indicated that plasma HMGB1 levels were negatively correlated to T cellular immune function parameters, including lymphocyte proliferation response, IL-2 production, and the ratio of CD4+/ CD8+ T cells in extensively burned patients (all P < 0.05). CONCLUSIONS: Extensive burns could lead to T cellular immune dysfunction, which appears to be associated with the development of MODS. HMGB1, as an important late mediators of inflammation, might be involved in the pathogenesis of suppression of T cell-mediated immunity in these patients.

Interaction studies of DNA binding of ruthenium(II) mixed-ligand complexes: [Ru(phen)2(dtmi)]2+ and [Ru(phen)2(dtni)]2+.

Two new ligands, 3-(pyrazin-2-yl)-as-triazino[5,6-f]-5-methoxylisatin (dtmi), 3-(pyrazin-2-yl)-as-triazino[5,6-f]-5-nitroisatin (dtni) and their ruthenium(II) complexes [Ru(phen)2(dtmi)](ClO4)2 (1) and [Ru(phen)2(dtni)](ClO4)2 (2) have been prepared and characterized by elemental analysis, FAB-MS, ES-MS and 1H NMR. The DNA-binding behaviors of complexes have been studied by spectroscopic titration, viscosity measurements, thermal denaturation and circular dichromism (CD). The results indicate that the complexes 1 and 2 interact with calf thymus DNA (CT-DNA) by intercalative mode. The DNA-binding affinity of the complexes 2 is larger than that complex 1 does.

[Study on the relationship between the human leucocyte antigen-DR expression on CD14+ monocytes and sepsis].

OBJECTIVE: To investigate the changes in the expression of HLA-DR on CD14+ monocytes of burn patients with delayed resuscitation, and to analyze the relationship between it and sepsis. METHODS: Twenty-five patients with total burn surface area over 30% TBSA and delayed resuscitation were enrolled in the study, among which 7 were complicated by sepsis during hospitalization. Peripheral blood was collected on 1, 3, 7, 14 and 28 post-burn days (PBD), and the blood of the patients with sepsis were also collected on the 1 and 2 days after the occurrence of sepsis. Twenty healthy volunteers were enrolled as controls. Expression rate of HLA-DR on CD14+ monocytes was determined by flow cytometry. The level of TNF-alpha and IL-10 were measured by ELISA. RESULTS: Expression rate of HLA-DR antigen on CD14+ monocytes in burn patients without sepsis on 1, 3, 7, 14, 28 PBD were (15 +/- 6)%, (7 +/- 5)%, (26 +/- 17)%, (28 +/- 16)% and (47 +/- 16)%, respectively, which were obviously lower than that of healthy people [(92 +/- 10)%, P < 0.01], and it was also markedly lower on 1 and 2 days after the occurrence of sepsis than that of controls and those of patients without sepsis on 1, 7, 14, 28 PBD (P < 0.01). The positive rate and concentration of TNF-alpha in patients with sepsis were obviously higher than that of healthy people and patients without sepsis (P < 0.05 or P < 0.01). There was a negative correlation between the expression rate of HLA-DR on CD14+ monocytes and IL-10 levels, and it showed significant difference on 1, 7, and 28 PBD (r = -0.9963, -0.7459, -0.8474, respectively, P < 0.01). CONCLUSION: Immune function is suppressed and proinflammatory mediators are excessively released in severely burn patients after delayed resuscitation, especially when complicated with sepsis. Expression of HLA-DR on CD14+ monocytes may be an useful parameter for monitoring the immune function of burn patients.

[Clinical significance of changes in quantitative expression of human leukocyte antigen DR in severely burned patients].

OBJECTIVE: To investigate the clinical significance of kinetic changes in quantitative expression of human leukocyte antigen DR (HLA-DR) in severely burned patients. METHODS: The blood samples of 77 extensively burned patients (>30% of total body surface area) were serially collected in the present study. The expression of HLA-DR on CD14(+) mononuclear cell surface in burned patients were quantified by flow cytometry (using monoclonal antibody, QuantiBRITETM Anti-HLA-DR PE(*)/Anti-Monocyte PerCP-Cy5.5) on days 1, 3, 5, 7, 14, 21 and 28 post burn. RESULTS: The expressions of HLA-DR on CD14(+) mononuclear cell surface in severely burned patients were significantly lower than those in healthy volunteers from the first day post burn (P < 0.05), and the value of HLA-DR expression was negatively correlated with the burned area (r = -0.7232, P < 0.05). The expression of HLA-DR in patients complicated with multiple organ dysfunction syndrome (MODS) was persistently decreased following major burns, and it was significantly lower than that of non-MODS patients on days 3, 14, 21 and 28 post burn (P < 0.05). The incidence rate of MODS rose markedly along with the lowering of HLA-DR expression, accompanied with poorer prognosis. CONCLUSIONS: Extensive burns could result in marked damage in expression of HLA-DR on CD14(+) mononuclear cell surface and immunologic dysfunction. Quantitative measurement of HLA-DR expression might be of significance in forecasting the development of MODS and prognosis in extensively burned patients.

[The clinical significance of changes in immunological function of T lymphocyte in severe burn patients with sepsis].

OBJECTIVE: To observe the immunological function changes in T lymphocyte in severe burn patients with sepsis, and to explore its relationship with sepsis. METHODS: Fifty-nine burn patients with burn surface exceeding 30% TBSA were enrolled in the study, and they were divided into sepsis group (S, n =43) and non-sepsis group (NS, n = 16). The peripheral venous blood samples of the patients in both groups were collected on 1, 3, 5, 7, 14, 21 and 28 post-burn days (PBD). The T lymphocyte proliferation ability and the interleukin-2 (IL-2) level in both groups were observed and the correlation between them were analyzed. The percentage of CD3+/CD4+ T lymphocytes and its apoptosis rate were determined by flow cytometry and the correlation between them was analyzed. RESULTS: Compared with that in NS group, the proliferation ability of T lymphocyte and the level of IL-2 were significantly decreased in patients in S group on 1, 14, 21, and 28 PBD (P < 0.05 or P < 0.01). The inhibition of T lymphocyte proliferation was positively correlated to the low level of IL-2 production in burn patients (r = 0.82, P < 0.01). The percentage of CD3+/CD4+ T lymphocytes in S group were obviously lower than that in NS group on 1, 5, 14, 21, 28 PBD, whereas on opposite tendency in the apoptosis rate of CD3+ CD4+ T lymphocytes were found at the same time (P < 0.05 or P < 0.01). The percentage of CD3+/CD4+ T lymphocytes was negatively correlated to apoptosis rate of T lymphocytes (r = -0.66, P < 0.05). CONCLUSION: The immunological function of T lymphocyte in severely burn patients with sepsis is depressed persistently. Apoptosis of T lymphocyte may participate in the pathological process of cell immunological disorder induced by sepsis.

[Expression of matrix metalloproteinase-2, -9 and their inhibitor-1 in hypertrophic scars].

OBJECTIVE: To investigate the gene expression of matrix metalloproteinases (MMP-2, MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in proliferative and mature hypertrophic scars. METHODS: Total RNA from 8 normal skin samples and from 16 human hypertrophic scar samples of different maturing stage was respectively extracted, and then mRNA was isolated. The gene expressions of MMP-2, MMP-9 and TIMP-1 in these samples were examined with reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The gray scale ratio of MMP-2, MMP-9 and TIMP-1 transcription in normal skin were (3.8 +/- 0.7)%, (5.8 +/-4.4)%, (30.3 +/- 3.0)%, respectively, which were obviously higher than those in proliferative hypertrophic scar [(14 +/- 5)%, (18 +/- 5)%, (38 +/- 4)%, P < 0.05]. The expression of MMP-2 and MMP-9 genes in mature hypotrophic scar returned to normal level, but that of TIMP-1 remained high when compared with that of normal level (P < 0. 05). CONCLUSION: The increase in MMP-2, MMP-9 and TIMP-1 gene expression might be involved in the formation of hypertrophic scars, while the lowering of MMP-2 and MMP-9 gene expression might be associated with the maturation of hypertrophic scars.