Raloxifene retards cartilage degradation and improves subchondral bone micro-architecture in ovariectomized rats with patella baja-induced - patellofemoral joint osteoarthritis.

OBJECTIVE: Abnormal remodeling of subchondral bone (SB) induced by estrogen deficiency has been shown to be involved in osteoarthritis (OA). Raloxifene (RAL) is commonly used to treat postmenopausal osteoporosis (OP). However, little is known about its effects on OA combined with estrogen deficiency. This study was performed to evaluate the efficacy of RAL on patella baja-induced patellofemoral joint OA (PFJOA) in an ovariectomized rat model. DESIGN: Patellar ligament shortening (PLS) and ovariectomy (OVX) were performed simultaneously in 3-month-old female Sprague-Dawley rats, which were treated with RAL (10 mg/kg/day) or vehicle at 72 h postoperatively for 10 weeks. PFJOA was assessed by immunohistochemistry (IHC), real-time polymerase chain reaction (PCR), tartrate-resistant acid phosphatase (TRAP) staining, enzyme-linked immunosorbent assay (ELISA), micro-computed tomography (µCT), histomorphology and behavioral analyses. RESULTS: X-ray examinations showed that patella baja was successfully established by PLS. Histomorphological analysis revealed that PFJOA was significantly exacerbated by OVX and markedly alleviated by RAL. Moreover, RAL improved cartilage metabolism by decreasing MMP-13, ADAMTS-4, and caspase-3 and increasing Col-II and aggrecan at both the protein and mRNA levels. Furthermore, RAL markedly improved bone mass and SB microarchitecture and reduced osteoclast numbers and the serum osteocalcin and CTX-I levels. Although RAL showed a trend toward reducing pain sensitivity based on mechanical allodynia testing, this result was not statistically significant. CONCLUSION: These findings demonstrate that RAL treatment retards PFJOA progression in an ovariectomized rat model, suggesting that it may be a potential candidate for amelioration of the progression of PFJOA accompanied by postmenopausal OP.

[Effects of RGD peptides-grafted porous tantalum on morphological change of MG63 osteoblasts-tantalum conjunctive interface and expression of osteogenesis factors].

OBJECTIVE: To investigate the effects of the Arg-Gly-Asp polypeptedes (RGD) peptides-modified porous tantalum surface on osteoblasts morphology and expressions of osteogenesis factors, and to evaluate RGD peptides promotes junctura ossium of tantalum-bone interface in vivo. METHODS: RGD peptides of different concentrations (1 g/L, 5 g/L, and 10 g/L) were loaded to porous tantalum slices with a diameter of 10 mm and a thickness of 3 mm by physical absorption. The 3rd generation of MG63 cells were co-cultured with tantalum and divided into 4 groups: Ta-cells (control) group, 1 g/L cells/Ta/RGD group, 5 g/L cells/Ta/RGD group, and 10 g/L cells/Ta/RGD group. Porous tantalum compo-sites and osteoblasts-tantalum interface were observed by scanning electron microscopy. The adhesion rate of osteoblasts was detected and immunocytochemistry was used to detect the expressions of filamentous actin (F-actin), osteocalcin (OC) and fibronectin (FN). RESULTS: The scanning electron microscope (SEM) revealed that osteoblasts distributed on the surface of porous tantalum and secreted extracellular matrix on outside and inner of micro-pores. The osteoblasts adhesion rate on porous tantalum modified with RGD was higher than that in the unmodified porous tantalum at the end of 24, 48, and 72 hours. The best adhesion effect was got in 5 g/L cells/Ta/RGD group at hour 48 [(68.07±3.80) vs. (23.40±4.39), P<0.05]. The results of immunocytochemistry showed that the expressions intensity of F-actin, OC and FN in osteoblasts on porous tantalum modified groups with RGD were stronger than that in the unmodified groups, and the expressions of 5 g/L cells/Ta/RGD group were significantly higher than those in the 10 g/L group and 1 g/L group [OC: (18.08±0.08) vs. (15.14±0.19), P<0.05; (18.08±0.08) vs. (14.04±0.61), P<0.05. FN: (24.60±0.98) vs. (15.90±0.53), P<0.05; (24.60±0.98) vs. (15.30±0.42), P<0.05. F-actin: (29.20±1.31) vs. (24.50±1.51), P<0.05; (29.20±1.31) vs. (16.92±0.40), P<0.05]. Correspondingly F-actin in osteoblasts was showed in longitudinal arrangement, and the expressions intensity was stronger than those OC and FN. CONCLUSION: The RGD peptides is beneficial to enhance adhesion of osteoblast, spreading and reorganization of cytoskeleton on porous tantalum surface and improve the interface morphology, further promoting osteoblasts-tantalum conjunctive interface osseointegration.

Parathyroid hormone (1-34) promotes fracture healing in ovariectomized rats with type 2 diabetes mellitus.

Ovariectomized (OVX) rats with type 2 diabetes mellitus (T2DM) with femur fracture received vehicle, insulin, or insulin plus parathyroid hormone (PTH) treatment for 2 and 3 weeks. Radiography, histomorphometry, histology, and immunohistochemistry in callus were evaluated. INTRODUCTION: Reports about effects of PTH plus insulin on callus formation of osteoporotic fracture with T2DM were limited. This study was designed to investigate the effects of the combination of PTH and insulin on fracture healing in OVX rats with T2DM. METHODS: Two-month-old female rats were randomly divided into five groups: normal fracture (F), OVX fracture (OF), T2DM + OVX fracture (DOF), insulin-treated (2-4 u/daylight, 4-6 u/night, DOFI), and treated with insulin and PTH (50 µg/kg/day, 5 days/week, DOFIP). A closed mid-shaft fracture was established in the right femurs of all rats after 6 weeks of OVX. Rats were euthanized at 2 and 3 weeks post-fracture according to the time schedule, respectively. RESULTS: The administration of insulin alone or insulin combined with PTH significantly increased mineralized bone volume fraction (BV/TV) and connectivity density (Conn.D) compared with those of the DOF group at 3 weeks post-fracture and also increased cartilaginous callus area ratio in the DOFI and DOFIP groups at 2 weeks and bony callus area ratio in the DOFIP groups at both the 2 and 3 weeks post-fracture. CONCLUSIONS: OVX rats with T2DM exhibited a marked delay in the fracture healing process; insulin treatment ameliorated these effects, and the healing process was enhanced following treatment with a combination of insulin and PTH.

Parathyroid hormone(1-34) exhibits more comprehensive effects than celecoxib in cartilage metabolism and maintaining subchondral bone micro-architecture in meniscectomized guinea pigs.

OBJECTIVE: To evaluate the effects of PTH(1-34) on cartilage, subchondral bone mass and structure in medial meniscectomized guinea pigs and compare them to those of celecoxib (CLX). METHOD: Forty-eight 3-month-old male Hartley albino guinea pigs received either sham or medial meniscectomy (MNX) operations. One week after the procedure, meniscectomized animals began 12 weeks of treatment by oral administration of CLX (20 mg/kg, daily), subcutaneous injection of PTH (1-34) (24 µg/kg, 5 days/week), or normal saline for MNX group. All animals were euthanized 12 weeks later, cartilage degeneration and subchondral bone micro-architecture was analyzed. RESULTS: OARSI scores indicated cartilage degeneration was partially inhibited by either CLX or PTH(1-34). Cartilage was significantly thicker in PTH(1-34)-treated animals than in CLX-treated animals. Both CLX and PTH(1-34) treatment were associated with lower ADAMTS-4 and periostin expression than MNX. MMP-13 expression in PTH(1-34) group was significantly lower than that in CLX group. However, AGG expression and the ratio of Col-II/MMP-13 expression in PTH(1-34) group were significantly higher than in the CLX group. Micro-CT analysis showed BMD, BV/TV, and Tb.Th levels to be significantly lower in the MNX group and CLX groups than in the sham group, but these parameters were significantly higher in the PTH(1-34) group than in either the MNX group or CLX group. CONCLUSIONS: Both CLX and PTH(1-34) exhibits protective effects on cartilage degeneration in meniscectomized guinea pigs. However, PTH(1-34) exhibited superior performance to CLX not only in metabolism of cartilage tissue but also in maintenance of subchondral bone micro-architecture.

Calcitonin suppresses intervertebral disk degeneration and preserves lumbar vertebral bone mineral density and bone strength in ovariectomized rats.

UNLABELLED: We investigated the effect of calcitonin (CT) on lumbar intervertebral disk degeneration (LIDD) in rats with ovariectomy-induced osteopenia. CT protected ovariectomized rats from LIDD by, at least in part, modifying extracellular matrix metabolism of the disks and preserving the microarchitecture and biomechanical properties of adjacent vertebrae. INTRODUCTION: The present study aimed to investigate the effect of CT on lumbar vertebral bone mineral density and intervertebral disk degeneration in ovariectomized (OVX) rats. METHODS: We first subjected 50 3-month-old female rats to either OVX (n = 30) or sham (n = 20). Twelve weeks later, ten OVX and ten sham rats were necropsied. The remaining OVX rats began to receive either saline vehicle (OVX + V, n = 10), or salmon CT (OVX + CT, 16 IU/kg/2 days, n = 10). After 12 weeks of treatment, necropsy was conducted and bone mineral density was determined in L3-4 and L5-6 vertebrae. The microstructure and biomechanical properties of L3 vertebrae were detected by micro-computed tomography and compression test, respectively. L5-6 was also used to measure intervertebral disk height and observe intervertebral disk histological changes by Van Gieson staining and histological scores, as well as immunohistochemistry (IHC) analysis of matrix metalloprotease (MMP)-1, MMP-13, and collagen II expression. RESULTS: At 12 weeks post-OVX, OVX rats had lower BV/TV and Tb.N and higher intervertebral disk histological score than sham rats. After 24 weeks, OVX + CT rats had higher BMD, BV/TV, Tb.N, and bone biomechanical strength values than OVX + V rats. Histological analysis showed OVX + CT rats had significantly lower disk degeneration scores than OVX + V rats. IHC analysis revealed CT treatment decreased expression of MMP-1 and MMP-13 and increased expression of collagen II compared with OVX + V rats. CONCLUSIONS: Our data demonstrate that CT-treated OVX rats display less intervertebral disk degeneration and favorable changes in intervertebral disk metabolism, associated with higher trabecular bone mass, better trabecular microarchitecture, and better biomechanical strength when compared to vehicle-treated OVX rats.

Parathyroid hormone (1-34) prevents cartilage degradation and preserves subchondral bone micro-architecture in guinea pigs with spontaneous osteoarthritis.

OBJECTIVE: To assess whether parathyroid hormone (PTH) (1-34) could improve the micro-structure of subchondral bone, and retard cartilage degradation in a naturally occurring Osteoarthritis (OA) model. DESIGN: Forty-eight 1-month-old guinea pigs were divided into two groups: 32 were treated by normal saline (NS) and sacrificed at 1, 3, 6 and 9 months of age; the other 16 received PTH (1-34) from 3 months, and were sacrificed at 6 and 9 months. Masson staining and the Osteoarthritis Research Society International (OARSI) grade scores were used to assess cartilage degradation. Immunohistochemistry analyses of type-II collagen, matrix metalloproteinases-13 (MMP-13) and sclerostin (SOST) in the cartilage, osteoprotegerin (OPG) and receptor activator of nuclear factor-kB ligand (RANKL) and PTH receptor (PTH1R) in the cartilage and subchondral bone were performed. Subchondral bone micro-architecture was assessed by micro-computed tomography (micro-CT). RESULTS: Histological analyses revealed OA occurred at 3 months of age and was more severe with increasing age, and PTH (1-34) reduced the OARSI scores at 6 and 9 months of age. Micro-CT analysis indicated that PTH (1-34) treatment increased the bone volume ratio and bone mineral density (BMD), while retarding the subchondral trabecular bone micro-architectural changes from rod-like to plate-like. Immunohistochemical staining demonstrated that PTH (1-34) treatment increased type-II collagen expression and decreased SOST and MMP-13 expression in the cartilage, while elevating the PTH1R, OPG/RANKL expression ratio in the cartilage and subchondral trabecular bone when compared with the control groups. CONCLUSIONS: PTH (1-34) can prevent cartilage damage progression and retard the deterioration of subchondral trabecular bone in guinea pigs.

[Influencing factors and their predictive value of skin graft survival after Meek grafting in severe burn patients].

Objective: To investigate the influencing factors and their predictive value of skin graft survival after Meek grafting in severe burn patients. Methods: A retrospective case-control study was conducted in 115 severe burn patients (95 males, 20 females, aged 1-74 years) who met the inclusion criteria and received Meek grafting in the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January 2013 to December 2019. The patients were divided into good skin graft survival group with skin graft survival rate≥70% (68 cases) and poor skin graft survival group with skin graft survival rate<70% (47 cases). The statistics of patients in the two groups were recorded during their first Meek grafting after admission including the gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level, preoperative platelet count, and platelet count on the first, third, and fifth day after operation. The above indicators were statistically analyzed between the two groups with independent sample t test, Mann-Whitney U test, and chi-square test. A 1∶1 propensity score matching (PSM) of the gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation of patients in the two groups were performed to eliminate the differences in baseline data, and then the above indicators of the remaining patients in the two groups were recorded and analyzed again. The indicators with statistically significant differences between the two groups after 1∶1 PSM were selected for multivariate logistic regression analysis to screen the independent risk factors affecting the skin graft survival after Meek grafting in severe burn patients. The receiver operating characteristic (ROC) curve of independent risk factors for predicting poor skin graft survival after Meek grafting in severe burn patients after 1∶1 PSM was drawn, and the area under the curve, the cut-off value, and the sensitivity and specificity under the cut-off value were calculated. The patients after 1∶1 PSM were divided into independent risk factor>the cut-off value group and independent risk factor≤the cut-off value group with the incidence of poor skin graft survival after Meek grafting compared using the chi-square test, and the relative risk of poor skin graft survival after Meek grafting was calculated. Results: Before 1∶1 PSM, there were no statistically significant differences in gender, age, body mass index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level of patients between the two groups (P>0.05); the full-thickness burn area and burn index of patients in poor skin graft survival group were significantly higher than those in good skin graft survival group (Z=-2.672, -2.882, P<0.01); the preoperative platelet count and the platelet count on the first, third, and fifth day after operation of patients in poor skin graft survival group were significantly lower than those in good skin graft survival group (Z=-3.411, -3.050, -2.748, -2.686, P<0.01). After 1∶1 PSM, 46 cases were remained in each group. There were no statistically significant differences in gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level of remaining patients between the two groups (P>0.05); the preoperative platelet count and the platelet count on the first, third, and fifth day after operation of patients in poor skin graft survival group were significantly lower than those in good skin graft survival group (Z=-3.428, -2.940, t=-2.427, -2.316, P<0.05 or P<0.01). Multivariate logistic regression analysis showed that the preoperative platelet count was the only independent risk factor affecting the skin graft survival after Meek grafting in severe burn patients (odds ratio=0.994, 95% confidence interval=0.989-0.998, P<0.01). The area under the ROC curve of preoperative platelet count predicting poor skin graft survival after Meek grafting in 92 patients was 0.707 (95% confidence interval=0.603-0.798, P<0.01), and the cut-off value of preoperative platelet count was 98×109/L, with sensitivity of 54.3% and specificity of 78.3% under the cut-off value. The incidence of poor skin survival after Meek grafting of patients in preoperative platelet count≤98×109/L group was 71.4% (25/35), which was obviously higher than 36.8% (21/57) in preoperative platelet count>98×109/L group (χ2=10.376, P<0.01). Compared with that in preoperative platelet count>98×109/L group, patients in preoperative platelet count≤98×109/L group had a relative risk of poor skin graft survival after Meek grafting of 2.211 (95% confidence interval=1.263-3.870). Conclusions: Preoperative platelet count is an independent risk factor affecting the skin graft survival after Meek grafting in severe burn patients and has a good predictive value. Meek grafting should be performed with caution when the preoperative platelet count of patients is≤98×109/L.

[Clinical application of extracorporeal membrane oxygenation in the treatment of burn patients with acute respiratory distress syndrome: a retrospective analysis and systematic review].

Objective: To analyze the clinical effect of extracorporeal membrane oxygenation (ECMO) in the treatment of burn patients with acute respiratory distress syndrome (ARDS). Methods: The retrospective observational study and the systematic review were applied. From March 2014 to July 2020, five burn patients with ARDS received ECMO treatment in the First Affiliated Hospital of Army Medical University (the Third Military Medical University). All the five patients were male, aged from 40 to 62 years. The average total burn surface area was 58.8% total body surface area (TBSA) and four cases had severe inhalation injury. Patient's ECMO starting time, duration and mode, and whether successfully weaned or the cause of death, and others. were recorded. Furthermore, the changes of oxygenation and infection before, during, and after utilizing ECMO were analyzed. PubMed and Web of Science from the establishment of each database to August 2021 were searched using "Extracorporeal Membrane Oxygenation", "ECMO", "burn", "inhalation" as the search terms and "Title/Abstract" as the field to retrieve the clinical articles that meet the selection criteria . Basic information were extracted from the articles, including sample size, gender, age, total burn area, inhalation injury, the indication of ECMO, the start and lasting time of ECMO, ECMO mode, rate of successful weaning, complications of ECMO, mortality, the combined application of continuous renal replacement therapy (CRRT). Results: Five patients started venovenous ECMO on an average of 10.2 days after injury and lasted an average of 180.4 hours. Three out of 5 patients were weaned successfully with one patient survived. Four patients died of multiple organ dysfunction syndrome (MODS) and septic shock. Compared with those before ECMO treatment, the arterial oxygen partial pressure (PaO2) and oxygen saturation in arterial blood (SaO2) of three successfully weaned patients obviously increased during and after ECMO treatment. The fraction of inspired oxygen (FiO2) decreased below 50% and PaO2/FiO2 ratio increased above 200 mmHg (1 mmHg=0.133 kPa) during and after ECMO. Furthermore, lactic acid and respiratory rate decreased, basically. Compared with those before ECMO, PaO2 and SaO2 in the other two patients during ECMO, who failed to be weaned, continuously decreased while lactic acid increased. Before and during ECMO, the PaO2/FiO2 ratios of unsuccessfullg weaned cases were less than 200 mmHg, and partial pressure of carbon dioxide in arterial blood (PaCO2) were more than 40 mmHg. Compared with those before ECMO, there were no significant changes in body temperature during and after ECMO, which were less than 38 ℃. Compared with those before ECMO, the leucocyte number (the index without this in unsuccessfully weaned cases was omitted, the same as below) in four patients showed a significant decrease during ECMO, but rose after removal of ECMO. The proportion of neutrophils in three patients were slightly higher during ECMO than before ECMO, and did not change significantly after removal of ECMO. Compared with those before ECMO, platelet counts in three patients were significantly reduced during ECMO, and all five patients during ECMO were below normal levels. Compared with those before ECMO, the procalcitonin levels in four deaths were significantly increased during ECMO. Catheter culture of microorganism was performed in three successfully weaned patients, all of which were negative. A total of 13 literature were included, ranging from 1990 to 2019. The sample size in 6 studies was less than 10, and the sample size in 4 studies was between 10 and 20, and only 2 literatures had a sample size larger than 50. ECMO was applied in 295 burn patients with overall mortality of 48.8% (144/295), including 157 adults and 138 children. The most common indication of ECMO was severe ARDS. Among 157 adult burn patients (95 males and 65 females), 36 cases had inhalation injury. The average burn area was 27%-37%TBSA in 5 reported studies and was more than 50%TBSA in 2 reported studies. The most common mode was venovenous ECMO. ECMO treatment began 26.5 hours to 7.4 days after injury and lasted from 90 hours to 18 days, and the rate of successful weaning ranged from 50% to 100%. The most common complications were bleeding and infection. The mortality was 52.9% (83/157). MODS and sepsis were the leading causes of death. Among 138 pediatric burn patients (77 boys and 61 girls), 29 patients had inhalation injury. The average burn area was 17%-50.2%TBSA in 3 studies. ECMO treatment lasted from 165.2 hours to 324.4 hours. Bleeding was the most common complication. The mortality was 44.2% (61/138). Conclusions: ECMO is an effective strategy for the salvage treatment of burns complicated with ARDS. Furthermore, the prevention and treatment of bleeding, infection and organ dysfunction should be emphasized during the use of ECMO. More importantly, evidence-based guidelines for burns are urgently needed to further improve the clinical effect of ECMO.

[Recommendations for normalizing the medical practices of burn treatment during the outbreak of coronavirus disease 2019].

2019 novel coronavirus (2019-nCoV) is one of the beta coronaviruses and is identified as the pathogen of the severe " coronavirus disease 2019 (COVID-19)" in 2019. China manages COVID-19 according to the reguirement of the highest level infectious diseases in China. Currently, the prevention and control of COVID-19 in China is at a critical period. Burn Department as an emergency discipline is confronted with risk of 2019-nCoV infection. Based on the guidelines for the diagnosis and treatment of COVID-19 (6th trial edition), in combination with the latest literature at home and abroad, the features of the COVID-19, the recommendations for the COVID-19 prevention and control issued by the National Health Commission of China, and the management experience of COVID-19 diagnosis and treatment of other related disciplines, we put forward some recommendations for the medical practices of burn treatment during the outbreak of the COVID-19 in outpatient and emergency, inpatient treatment, and the management of operation theatres and wards, etc. We hope these recommendations could benefit the medical professionals in the field of burn treatment and relevant hospital management during the outbreak of COVID-19, improve burn treatment, and avoid or reduce the risk of infection of medical staff.

[Retrospective study on the characteristics of early organ injury in elderly patients with severe burns].

Objective: To analyze the clinical characteristics of early organ injury in elderly patients with severe burns and the effects on the prognosis of patients. Methods: From January 2010 to August 2018, 62 patients with severe burns (43 men and 19 women, aged from 60 to 89 years at the time of admission) who were hospitalized in the Institute of Burn Research of the First Affiliated Hospital of Army Medical University (the Third Military Medical University, hereinafter referred to as the author's affiliation), meeting the inclusion criteria, were included in elderly (E) group, and 124 patients with severe burns (86 men and 38 women, aged from 18 to 59 years at the time of admission) at the same term were included in young and middle-aged (YM) group. Treatment of patients in the 2 groups followed the conventional procedures of the author's affiliation. The following data of patients in the 2 groups were retrospectively analyzed. (1) Fluid replacement volume and urine volume within the first and second post injury hour (PIH) 24 were recorded. The levels of hemoglobin, haematocrit, and blood lactic acid at admission, PIH 24 and 48 were recorded. (2) The creatine kinase isozyme-MB (CK-MB), total bilirubin, blood creatinine, oxygenation index, and blood platelet count at admission, at shock stage, and on post injury day (PID) 3 to 7 were collected. (3) The days of seriously or critically ill and deaths were recorded. Data were processed with chi-square test, group t test, Mann-Whitney U test, analysis of variance for repeated measurement, and Bonferroni correction. Results: (1) There were no statistically significant differences in fluid replacement volume within the first and second PIH 24, and urine volume within the second PIH 24 between patients in the 2 groups (t=0.351, 1.307, 1.110, P>0.05). The urine volume of patients in group E within the first PIH 24 was significantly less than that in group YM (t=5.628, P<0.05). There were no statistically significant differences in levels of hemoglobin (t=0.011, 1.075, 0.239), haematocrit (t=0, 0.033, 0.199), and blood lactic acid (t=0.017, 1.002, 0.739) at admission, PIH 24 and 48 between patients in the 2 groups (P>0.05). (2) There were no statistically significant differences in levels of CK-MB at admission and on PID 3 to 7 between patients in the 2 groups (t=0.069, 0.001, P>0.05). The level of CK-MB of patients in group E at shock stage was significantly higher than that in group YM (t=4.017, P<0.05). There were no statistically significant differences in levels of total bilirubin at admission and on PID 3 to 7 between patients in the 2 groups (t=0.227, 0.002, P>0.05). However, the level of total bilirubin of patients in group E at shock stage was significantly higher than that in group YM (t=6.485, P<0.05). The levels of blood creatinine of patients in group E at admission and shock stage were significantly higher than those in group YM (t=4.226, 12.299, P<0.05 or P<0.01), while there was no statistically significant difference between them on PID 3 to 7 (t=0.693, P>0.05). The oxygenation indexes of patients in group E at admission and shock stage and on PID 3 to 7 [(371±16), (263±16), and (228±18) mmHg (1 mmHg=0.133 kPa)] were lower than (420±13), (327±13), and (281±17) mmHg of patients in group YM, respectively (t=5.650, 9.782, 4.856, P<0.05 or P<0.01). There were no statistically significant differences in levels of blood platelet count at admission and shock stage between patients in the 2 groups (t=0.038, 0.588, P>0.05), while the level of blood platelet count of patients in group E on PID 3 to 7 was significantly lower than that in group YM (t=6.636, P<0.05). (3) The days of seriously or critically ill and death rate of patients in group E were respectively longer or higher than those in group YM (Z=-2.303, χ(2)=13.676, P<0.05 or P<0.01). Conclusions: In the case of the same tissue perfusion at shock stage, injuries in heart, liver, kidney, lung, and coagulation system in elderly patients with severe burns are more obvious than those in young and middle-aged patients, with more severe illness and higher mortality.

[In vitro study of effects of transient receptor potential vanilloid 1 on autophagy in early hypoxic mouse cardiomyocytes and the mechanism].

Objective: To explore the effects of transient receptor potential vanilloid 1 (TRPV1) on autophagy in early hypoxic mouse cardiomyocytes and the mechanism in vitro. Methods: The hearts of 120 C57BL/6 mice aged 1-2 days, no matter male or female, were isolated, and then primary cardiomyocytes were cultured and used for the following experiments, the random number table was used for grouping. (1) The cells were divided into normoxia group and hypoxia 3, 6, and 9 h groups, with one well in each group. The cells in normoxia group were routinely cultured (the same below), the cells in hypoxia 3, 6, and 9 h groups were treated with fetal bovine serum-free and glucose-free Dulbecco' s modified Eagle medium under low oxygen condition in a volume fraction of 1% oxygen, 5% carbon dioxide, and 94% nitrogen for 3, 6, and 9 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, TRPV1 were determined with Western botting. (2) The cells were divided into normoxia group and hypoxia group, with two coverslips in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above. The positive expression of TRPV1 was detected by immunofluorescence assay. (3) The cells were divided into 4 groups, with one well in each group. The cells in simple hypoxia group were treated with hypoxia for 6 h as above, and the cells in hypoxia+ 0.1 µmol/L capsaicin group, hypoxia+ 1.0 µmol/L capsaicin group, and hypoxia+ 10.0 µmol/L capsaicin group were respectively treated with 0.1, 1.0, 10.0 µmol/L capsaicin for 30 min before hypoxia for 6 h. The protein expressions of LC3, Beclin-1, and TRPV1 were detected by Western blotting. (4) The cells were divided into 5 groups, with 5 wells in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ chloroquine group, hypoxia+ capsaicin group, and hypoxia+ capsaicin+ chloroquine group were treated with hypoxia for 6 h after being cultured with 50 µmol/L chloroquine, 10.0 µmol/L capsaicin, and 50 µmol/L chloroquine+ 10.0 µmol/L capsaicin for 30 min, respectively. Viability of cells was detected by cell counting kit 8 assay. (5) The cells were divided into simple hypoxia group and hypoxia+ 10.0 µmol/L capsaicin group, with one well in each group. The cells in hypoxia group were treated with hypoxia for 6 h as above, the cells in hypoxia+ 10.0 µmol/L capsaicin group were treated with 10.0 µmol/L capsaicin for 30 minutes and then with hypoxia for 6 h. The protein expressions of lysosomal associated membrane protein 1 (LAMP-1) and LAMP-2 were detected by Western blotting. Each experiment was repeated for 3 or 5 times. Data were processed with one-way analysis of variance, least significant difference t test, and Bonferroni correction. Results: (1) Compared with those of normoxia group, the protein expressions of LC3, Beclin-1, and TRPV1 were significantly increased in cardiomyocytes of hypoxia 3, 6, and 9 h groups (t(3 h)=4.891, 5.890, 4.928; t(6 h)=9.790, 6.750, 10.590; t(9 h)=6.948, 6.764, 5.049, P<0.05 or P<0.01), which of hypoxia 6 h group were the highest (1.08±0.05, 1.12±0.10, 0.953±0.071, respectively). (2) The density of TRPV1 in cell membrane and inside the cardiomyocytes in hypoxia group was significantly increased with lump-like distribution, and the expression of TRPV1 was higher than that in normoxia group. (3) Compared with those of simple hypoxia group, the protein expression of Beclin-1 in cardiomyocytes of hypoxia+ 0.1 µmol/L capsaicin group was increased (t=10.488, P<0.01), while the protein expressions of LC3 and TRPV1 were increased without statistically significant differences (t=4.372, 3.026, P>0.05); the protein expressions of LC3, TRPV1, and Beclin-1 in cardiomyocytes of hypoxia+ 1.0 µmol/L capsaicin group and hypoxia+ 10.0 µmol/L capsaicin group were significantly increased (t=15.505, 5.773, 13.430; 20.915, 8.054, 16.384; P<0.05 or P<0.01), which of hypoxia+ 10.0 µmol/L capsaicin group were the highest (2.33±0.09, 1.34±0.07, 1.246±0.053, respectively). (4) Compared with 0.585±0.045 in normoxia group, the cardiomyocyte viability in hypoxia group was significantly decreased (0.471±0.037, t=4.365, P<0.05). Compared with that in hypoxia group, the cardiomyocyte viability in hypoxia+ chloroquine group was further decreased (0.350±0.023, t=6.216, P<0.01), while 0.564±0.047 in hypoxia+ capsaicin group was significantly increased (t=3.489, P<0.05). Compared with that in hypoxia+ chloroquine group, the cardiomyocyte viability in hypoxia+ capsaicin+ chloroquine group did not significantly change (0.364±0.050, t=0.545, P>0.05). (5) Compared with 0.99±0.04 and 0.54±0.04 in simple hypoxia group, the protein expressions of LAMP-1 and LAMP-2 in hypoxia+ 10.0 µmol/L capsaicin group were significantly increased (1.49±0.06, 0.81±0.05, t=12.550, 7.442, P<0.01). Conclusions: TRPV1 can further promote the expression of autophagy-related proteins in hypoxic cardiomyocytes through autophagy-lysosomal pathway, enhance autophagy activity, and improve autophagic flow for alleviating early hypoxic cardiomyocyte injury.

Irradiation effects on embryotoxicity and oxidative properties of gossypol dissolved in methanol.

Gossypol dissolved in methanol (0.25 and 0.5 mg/ml) was gamma-irradiated at 0, 5, 10, and 20 kGy. The gossypol content was significantly reduced by irradiation in a dose-dependent manner. Ames test performed with nonirradiated and irradiated gossypol solutions was negative at the level of 0.1, 0.5, 1, 10, 50, and 100 microg gossypol/plate. At the gossypol concentration of 2.5 microg/ml, the blastocysts formation rate of mice embryo were decreased by a factor of two as compared with the control, but irradiation at 20 kGy increased the blastocysts formation, resulting in no difference from the control. Addition of gossypol to oil emulsion system or oil showed a prooxidative effect of lipids at the beginning stage by increasing 2-thiobarbituric acid reactive substances (TBARS) and peroxide value but irradiation of the gossypol solution decreased the oxidative changes significantly as compared with the nonirradiated one. Results indicated that irradiation decreased the gossypol concentration dissolved in methanol, resulting in a reduction of embryotoxicity in mice.

Microdetermination of aldose and aldehyde reductases from human tissues.

Microfluorometric method has been described for the determination of aldose reductase and aldehyde reductase II activities in human erythrocyte, brain, and lens. The enzyme activity determined by the microfluorometric method was compared with the activity determined spectrophotometrically by following the oxidation of NADPH and fluorometrically by the formation of sorbitol. The activity of aldose reductase in homogenous preparations from human lens, brain, and erythrocyte was identical when determined by NADPH oxidation, NADP formation, and sorbitol formation using glucose as substrate and NADPH as co-factor. This indicated that NADPH oxidation by aldose reductase is not due to a non-specific oxidation by oxidants generated as a result of interaction of aldose reductase and glucose. Similarly, the activity of aldehyde reductase II obtained by NADPH oxidation and that by NADP formation were in good agreement. The microfluorescent method is convenient and accurate and can be used for the determination of aldose reductase in human tissues using glucose as substrate even when the sample size is small.

Effect of gamma irradiation on the survival of pathogens in kwamegi, a traditional Korean semidried seafood.

Kwamegi (semidried raw Pacific saury) is traditional seafood available in Korea. It has water activity in the range of 0.90 to 0.95. Spoilage and the growth of most pathogenic bacteria is retarded because of low water activity, low temperature, and packaging. However, it is contaminated with bacteria of public health significance and poses a hazard to the consumer because it is consumed raw without any cooking. The effectiveness of these hurdles in preventing the growth of Staphylococcus aureus, Bacillus cereus, Salmonella Typhimurium, and Escherichia coli and the efficacy of irradiation treatment in eliminating these bacteria from kwamegi using inoculated pack studies was examined. Radiation sensitivity of S. aureus, B. cereus, Salmonella Typhimurium, and E. coli in kwamegi was investigated. D10-values of these organisms in kwamegi were 590 +/- 13.6, 640 +/- 14.9, 560 +/- 45.4, and 550 +/- 8.6 Gy, respectively. The growth of all four test organisms inoculated into these foods during 4 weeks of storage at an ambient winter temperature (ranging from -5 degrees C to +5 degrees C) was recorded. All four pathogens (inoculated at 10(6) CFU/g) were eliminated by irradiation at 4 kGy. These studies unequivocally demonstrate that irradiation, with a combination of low water activity and low temperature, results in microbiologically safe kwamegi.

Activities of aldose reductase, ATPases, and nucleotide concentrations of erythrocytes in patients with type 2 (non-insulin-dependent) diabetes mellitus.

Aldose reductase (EC 1.1.1.21) is implicated in the pathophysiology of diabetic complications. In this paper we determined the activities of aldose reductase and ATPases of the erythrocytes in 17 patients with Type 2 (non-insulin-dependent) diabetes mellitus (NIDDM). In the aldose reductase assay we used fluorometric method to avoid the disturbance of hemoglobin. With dihydronicotinamide adenine dinucleotide (NADH), we verified it was aldose reductase but not aldehyde reductase II that was activated in the erythrocytes of the patients with NIDDM. The aldose reductase activity of the erythrocytes in the patients was significantly higher (P less than 0.01) than that in the controls. The activity of Na+/K(+)-ATPase of the patients was significantly lower (P less than 0.01) than that of the controls. The activities of Ca(2+)-ATPase and Mg(2+)-ATPase on the erythrocyte membranes of the patients were similar to those of the controls. At the same time we measured the seven nucleotide concentrations in the erythrocytes of the patients. In this experiment we used ultrafiltration method, instead of acid precipitation to make it possible to determine dihydronicotinamide adenine dinucleotide phosphate (NADPH) and NADH. The concentrations of ATP, ADP and AMP were similar to those of the controls. The concentrations of NADPH, NAD+ and NADH in the erythrocytes of the patients were significantly lower (P less than 0.01, 0.05 and 0.05 respectively) than those of controls. The concentration of nicotinamide adenine dinucleotide phosphate (NADP+) in the patients was significantly higher (P less than 0.01) than that of controls.

Determination of InN/Diamond Heterojunction Band Offset by X-ray Photoelectron Spectroscopy.

Diamond is not only a free standing highly transparent window but also a promising carrier confinement layer for InN based devices, yet little is known of the band offsets in InN/diamond system. X-ray photoelectron spectroscopy was used to measure the energy discontinuity in the valence band offset (VBO) of InN/diamond heterostructure. The value of VBO was determined to be 0.39 ± 0.08 eV and a type-I heterojunction with a conduction band offset (CBO) of 4.42 ± 0.08 eV was obtained. The accurate determination of VBO and CBO is important for the application of III-N alloys based electronic devices.

[Screening of all types of alleles of (A-C)n dinucleotide tandem repeat sequence of aldose reductase gene].

The screening method of seven alleles (Z-6, Z-4, Z-2, Z, Z + 2, Z + 4 and Z + 6) in the (A-C)n dinucleotide tandem repeat sequence was studied. These alleles constitute a microsatellite DNA marker upstream of the transcription initiation site on the aldose reductase gene. At first, genoimic DNAs were isolated from leucocyte pellets, and the region containing the dinucleotide repeats was amplified by PCR with a pair of amplification primers that flanked 132-144 bp region. Then, the PCR products of the DNA samples whose alleles belonged to homozygotes were selected, purified, and sequenced directly in order to find out the types of alleles. Finally, using Z-2 allele as a marker, the samples containing Z-2 allele were detected by 12% fromamide-urea gel electrophoresis together with silver-staining. This method is simple, quick and accurate. It facilitates the screening of a large number of samples and is also suitable for identification of other dinucleotide tandem repeat sequences.

[Study on base insertion/deletion of CAG-rich region in insulin receptor substrate-1 5'-regulatory sequence].

To study the relationship of the polymorphism of the insulin receptor substrate-1 (IRS-1) gene 5'-flanking regulatory sequence and Type 2 diabetes, the IRS-1 gene 5'-flanking regulatory sequence was scanned by PCR-SSCP in 78 healthy control subjects and 76 Type 2 diabetic subjects. Applying PCR-denatured polyacrylamide gel electrophoresis and silver staining, the insertion/deletion polymorphism of the CAG-rich region was analyzed. The genome DNA of the normal and variant subjects was amplified with high-fidelity pfu DNA polymerase. The purified and digested target fragments were then subcloned into the pCAT Basic vector. Each allele was identified according to the mobility by the restrictive endonuclease digestion of the recombinant combined with denatured polyacrylamide gel electrophoresis and silver staining, and finally the constructive plasmids containing different alleles were analyzed by DNA sequencing. Firstly, we found several insertion/deletion variations in the CAG-rich region of IRS-1 gene. Secondly, 7 genotypes and 6 alleles(T1-T6) in this site were detected. Moreover, T5 and T6 were only observed in Type 2 diabetic group.