Active bone material containing modified recombinant human bone morphogenetic protein 2 induces bone regeneration in the alveolar process cleft in rabbits.

The clinical application of most materials used to fill severe bone defects is limited owing to the insufficient ability of such materials to induce bone regeneration over a long repair period. The purpose of this study was to establish a model for the alveolar process cleft in rabbits to evaluate the effect of active bone material in bone defect repair. The active bone material used in this study is a new bone repair material composed of a heterogeneous collagen membrane implanted with modified recombinant human bone morphogenetic protein 2. This proposed active bone material can specifically bind to collagen. Twenty-four young Japanese white rabbits (JWRs) were selected and randomly divided into four groups (normal, control, material, and bone morphogenetic protein groups). The alveolar process cleft model was established by removing an equal volume bone at the left maxillary position. Blood samples were collected from the JWRs 3 and 6 months after the surgery to evaluate the biocompatibility of the active bone materials. Subsequently, the skull model was established, and the appearance was observed. Imaging methods (including X-ray examination and micro-computerized tomography scanning), tissue staining, and immunohistochemistry were employed for the evaluation. The bone collagen material and active bone material exhibited high biocompatibility. In addition, the ability of the active bone material to induce bone repair and regeneration was higher than that of the bone collagen material. The active bone material exhibited satisfactory bone regeneration performance in rabbits, indicating its potential as an active material for repairing congenital alveolar process clefts in humans.

Repair of alveolar cleft bone defects by bone collagen particles combined with human umbilical cord mesenchymal stem cells in rabbit.

BACKGROUND: Alveolar cleft is a type of cleft lip and palate that seriously affects the physical and mental health of patients. In this study, a model of the alveolar cleft phenotype was established in rabbits to evaluate the effect of bone collagen particles combined with human umbilical cord mesenchymal stem cells (HUC-MSCs) on the repair of alveolar cleft bone defects. METHODS: A model of alveolar clefts in rabbits was established by removing the incisors on the left side of the upper jaw bone collagen particles combined with HUC-MSCs that were then implanted in the defect area. Blood biochemical analysis was performed 3 months after surgery. Skull tissues were harvested for gross observation, and micro-focus computerised tomography (micro-CT) analysis. Tissues were harvested for histological and immunohistochemical staining. The experiments were repeated 6 months after surgery. RESULTS: Bone collagen particles and HUC-MSCs showed good biocompatibility. Bone collagen particles combined with HUC-MSCs were markedly better at inducing bone repair and regeneration than bone collagen particles alone. CONCLUSIONS: Combining HUC-MSCs with bone collagen particles provides a simple, rapid and suitable method to fill a bone defect site and treat of alveolar cleft bone defects.

Synovial Fluid Macrophage Migration Inhibitory Factor Levels Correlate with Severity of Self-Reported Pain in Knee Osteoarthritis Patients.

BACKGROUND Inflammation is considered as one of the main pathogeneses in OA-induced pain. Macrophage migration inhibitory factor (MIF) is a well known pro-inflammatory cytokine. We aimed to determine whether MIF levels in serum and synovial fluid (SF) are associated with severity of OA-induced pain. MATERIAL AND METHODS We recruited 226 patients with knee OA and 106 controls. Self-reported pain severity of OA patients was evaluated using the Western Ontario McMaster University Osteoarthritis (WOMAC) pain scores. MIF levels were detected using enzyme-linked immunosorbent assay (ELISA). RESULTS OA patients had similar serum MIF levels compared to controls (11.93 [5.68-18.10] vs. 10.06 [6.60-14.61] ng/ml, P>0.05). In OA patients, MIF levels in SF were dramatically lower compared to paired serum samples (3.39 [1.87-5.89] vs. 11.93 [5.68-18.10] ng/ml, P<0.01). MIF levels in SF were significantly correlated with WOMAC pain scores (r=0.237, P<0.001), but MIF levels in serum had no significant correlation with WOMAC pain scores (r=0.009, P=0.898). CONCLUSIONS MIF levels in SF, but not in serum, were independently associated with the severity of self-reported pain in OA patients. The inhibition of MIF signaling pathways may be a novel therapeutic approach for ameliorating OA-induced pain.

A giant magnetoimpedance-based biosensor for sensitive detection of Escherichia coli O157:H7.

A giant magnetoimpedance (GMI)-based biosensor was developed for detection of Escherichia coli (E. coli) O157: H7. The GMI sensor involving the sensing elements of Cr/Cu/NiFe/Cu/NiFe was fabricated by Micro Electro-Mechanical system (MEMS) technology, including thick photoresist lithography and electroplating. A separate Au film substrate as immunoplatform was used to capture E. coli O157:H7. The monoclonal mouse anti-E. coli antibody was immobilized on Au film substrate surface with a self-assembled layer. The different concentration E. coli O157:H7 (100, 300 and 500 cfu/ml) were combined with Dynabeads-antibody conjugates (DAC) respectively. DAC were prepared by conjugating streptavidin-coupled Dynabeads with biotin-labeled polyclonal mouse anti-E. coli antibodies. The classical sandwich assay was used for detection of E. coli O157:H7 targeted with Dynabeads by using antibody-antigen pair combination of biotin-streptavidin. The fundamental principle for detection of E. coli O157:H7 based on GMI sensor was that Dynabeads were employed as magnetic labels of E. coli O157:H7, and E. coli O157:H7 can be monitored by detecting the fringe field of Dynabeads using magnetic sensing elements. We observed that the GMI ratio were significantly improved due to the presence of E. coli O157:H7 combined with Dynabeads. The GMI ratio increased as the E. coli O157:H7 concentration increased. A lower detectable concentration of 100 cfu/ml was achieved in present work. The GMI-based biosensor provides a new method to rapid and sensitive detection E. coli O157:H7, which has a large potential for bio-application.

Human Umbilical Cord Mesenchymal Stem Cells Combined with Dehydroepiandrosterone Inhibits Inflammation-Induced Uterine Aging in Mice.

With the postponement of the reproductive age of women, the difficulty of embryo implantation caused by uterine aging has become a key factor restricting fertility. However, there are few studies on protective interventions for naturally aging uteri. Although many factors cause uterine aging, such as oxidative stress (OS), inflammation, and fibrosis, their impact on uterine function manifests as reduced endometrial receptivity. This study aimed to use a combination of human umbilical cord mesenchymal stem cells (hUC-MSCs) and dehydroepiandrosterone (DHEA) to delay uterine aging. The results showed that the combined treatment of hUC-MSCs + DHEA increased the number of uterine glandular bodies and the thickness of the endometrium while inhibiting the senescence of endometrial epithelial cells. This combined treatment alleviates the expression of OS (reactive oxygen species, superoxide dismutase, and GSH-PX) and proinflammatory factors (interleukin [IL]-1, IL6, IL-18, and tumor necrosis factor-α) in the uterus, delaying the aging process. The combined treatment of hUC-MSCs + DHEA alleviated the abnormal hormone response of the endometrium, inhibited excessive accumulation and fibrosis of uterine collagen, and upregulated uterine estrogen and progesterone receptors through the PI3K/AKT/mTOR pathway. This study suggests that uterine aging can be delayed through hUC-MSCs + DHEA combination therapy, providing a new treatment method for uterine aging.

[Effects of intraperitoneal injection of marrow mesenchymal stem cells on intestinal barrier in acute pancreatitis].

OBJECTIVE: To explore the effects of intraperitoneal injection of mesenchymal stem cells (MSC) on intestinal barrier in serve acute pancreatitis (SAP) rats. METHODS: MSC were harvested and cultured from femurs of one male SD rat. And 30 female SD rats were divided into 3 groups: control group (n = 6), SAP group (n = 12) and MSC transplantation group (n = 12). SAP was induced by intraperitoneal injection of L-arginine (2 g/kg) twice in SAP and MSC groups. In MSC group, the third-generation MSC (5×10(6)) were injected intraperitoneally once daily for 3 days. All rats were sacrificed after 72 h. The histomorphologic alternations of small intestine were measured to evaluate the therapeutic effect of MSC transplantation. Reverse transcription (RT)-PCR were used to identify the expression of TNF-α mRNA and IL-1ß mRNA in small intestine and pancreas. Small intestine and pancreatic samples were examined for the engraftment of donor-derived MSC by Y chromosome in situ hybridization analysis. RESULTS: Compared with SAP group, histomorphologic alternations of small intestine significantly lower in MSC group (4.17 ± 0.28 vs 3.00 ± 0.33, P < 0.05). The relative expression quantity of TNF-α mRNA and IL-1ß mRNA in pancreas were both significant higher in SAP and MSC groups than those in control group (3.10 ± 0.73 and 1.92 ± 0.37 vs 0.51 ± 0.24, 4.60 ± 0.59 and 2.43 ± 0.39 vs 1.15 ± 0.18, all P < 0.05). Compared with SAP group, the expression quantity of TNF-α mRNA and IL-1ß mRNA in pancreas significantly lower in MSC group (both P < 0.05). The relative expression quantity of TNF-α mRNA and IL-1ß mRNA in small intestine were both significant higher in SAP and MSC groups than those in control group (2.73 ± 0.91 and 1.55 ± 0.48 vs 0.62 ± 0.20, 5.20 ± 0.94 and 2.10 ± 0.34 vs 0.99 ± 0.10, all P < 0.05). The expressions of TNF-α mRNA and IL-1ß mRNA in MSC group were lower than those in SAP group (both P < 0.05). Sry gene was not detected in pancreatic and intestinal tissue of MSC-treated rats. CONCLUSIONS: Syngraft MSC exert protective effects on pancreas and small intestine injury. And their beneficial effects are primarily mediated via indirect actions but not by their differentiation into target cells.

Application of Human Umbilical Cord Mesenchymal Stem Cells in Rat Spinal Cord Injury Model.

The treatment of spinal cord injury (SCI) is a hot topic in clinic. In this study, female rats were selected and randomly divided into four groups (normal, sham, SCI, and mesenchymal stem cells [MSCs] groups). Hemostatic forceps were used to clamp the spinal cord for 1 min to establish the SCI animal model in rats. The levels of proinflammatory factors in the blood of each group were compared 4 h after operation. The motor function of hind limb was estimated by Basso, Beattie & Bresnahan Locomotor rating scale (BBB scale) at 3 months after surgery, the spinal cord tissue from the experimental area was obtained and stained histologically and immunohistochemically. Basso, Beattie & Bresnahan Locomotor rating scale results indicated that human umbilical cord (HUC) MSCs transplantation could improve the walking ability in rats with the SCI. Human umbilical cord mesenchymal stem cells substantially upregulated the secretion of anti-inflammatory factors and downregulated the secretion of proinflammatory factors, and promoted the repair of the SCI and inhibited the increase of glial cells induced by the SCI. Human umbilical cord mesenchymal stem cells transplantation can partially recovered the motor ability of rats with the SCI through promoting the regeneration of nerve cell and the expression of neural related genes, and inhibiting inflammatory reaction.

Characteristics, differential diagnosis, individualized treatment, and prevention of hyperhomocysteinemia in newborns.

OBJECTIVES: This study aimed to investigate the incidence rate, clinical phenotype, gene variation spectrum, and prognosis of neonatal hyperhomocysteinemia (HHcy) and explore its diagnosis, individualised treatment, and prevention strategies. METHODS: We screened 84722 neonates for HHcy using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with biochemical detection, urine gas chromatography-mass spectrometry (GC-MS), and next-generation sequencing (NGS) for gene analysis to comprehensively differentiate and diagnose diseases. RESULTS: 18 children (P1-P18) were diagnosed with methylmalonic acidemia (MMA) and HHcy, and fourteen known and one new variant of the MMACHC gene were found. Five children showed poor mental reactions, brain dysplasia, lethargy, hyperbilirubinemia, and jaundice, whereas the other 13 children had no evident abnormalities. These children were all cobalamin- and folic acid-reactive types, and they were mainly supplemented with cobalamin, L-carnitine, betaine, and folic acid. The mother of P12 had a prenatal diagnosis at the next pregnancy; the results showed that MMACHC gene was not pathogenic and she gave birth to a healthy baby. One child (P19) was diagnosed with methylenetetrahydrofolate reductase (MTHFR) deficiency, and one new mutation was detected in the MTHFR gene. Patient P19 showed congenital brain dysplasia, neonatal anaemia, and hyperbilirubinemia, and treatment consisted mainly of betaine and cobalamin supplementation. One child (P20) was confirmed to have methionine adenosyltransferase I (MAT I) deficiency but had no clinical manifestations. After treatment, all the children had a good prognosis. CONCLUSION: The incidence of neonatal HHcy in the Zibo area was 1/4236, and the common pathogenic variants were c.609G>A, c.80A>G, and c.482G>A in the MMACHC gene. Patients with HHcy can achieve a good prognosis if pathogenic factors and targeted treatment are identified. Gene analysis and prenatal diagnosis contribute to the early prevention of HHcy.

Amniotic fluid karyotype analysis and prenatal diagnosis strategy of 3117 pregnant women with amniocentesis indication.

Aim: To examine prenatal diagnosis strategies through fetal karyotype analysis for 3117 pregnant women with genetic amniocentesis indications. Materials & methods: According to the different indications for amniocentesis, the study was divided into 8 groups. The number of amniocentesis specimens, the number of abnormal karyotypes and the positive rate of each group were analyzed. Results: Compared with prenatal serum screening, noninvasive prenatal DNA testing is more accurate and can effectively improve screening efficiency. Multiple prenatal diagnosis indicators (37.349%) were more likely to be detected than single prenatal diagnosis indicators (11.091%). Conclusion: None of the screening methods can completely replace amniocentesis, and for pregnant women with genetic indications for amniocentesis, amniocentesis is strongly recommended.

Combining Bone Collagen Material with hUC-MSCs for Applicationto Spina Bifida in a Rabbit Model.

Spina bifida is one of the neural tube defects, with a high incidence in human birth defects, which seriously affects the health and quality of life of patients. In the treatment of bone defects, the source of autologous bone is limited and will cause secondary damage to the patient. At the same time, since the bone tissue in animals needs to play a variety of biological functions, its complex structure cannot be replaced by a single material. The combination of mechanical materials and biological materials has become a common choice. Human umbilical cord mesenchymal stem cells (hUC-MSCs) have the advantages of easy access, rapid proliferation, low immunogenicity, and no ethical issues. It is often used in the clinical research of tissue regeneration and repair. Therefore, in this study, we established a spina bifida model using Japanese white rabbits. This model was used to screen the best regenerative repair products for congenital spina bifida, and to evaluate the safety of regenerative repair products. The results showed that the combination of hUC-MSCs with collagen material had better regeneration effect than collagen material alone, and had no negative impact on the health of animals. This study provides a new idea for the clinical treatment of spina bifida, and also helps to speed up the research progress of regenerative repair products.

Combining Bone Collagen Matrix with hUC-MSCs for Application to Alveolar Process Cleft in a Rabbit Model.

BACKGROUND: Most materials used clinically for filling severe bone defects either cannot induce bone re-generation or exhibit low bone conversion, therefore, their therapeutic effects are limited. Human umbilical cord mesenchymal stem cells (hUC-MSCs) exhibit good osteoinduction. However, the mechanism by which combining a heterogeneous bone collagen matrix with hUC-MSCs to repair the bone defects of alveolar process clefts remains unclear. METHODS: A rabbit alveolar process cleft model was established by removing the bone tissue from the left maxillary bone. Forty-eight young Japanese white rabbits (JWRs) were divided into normal, control, material and MSCs groups. An equal volume of a bone collagen matrix alone or combined with hUC-MSCs was implanted in the defect. X-ray, micro-focus computerized tomography (micro-CT), blood analysis, histochemical staining and TUNEL were used to detect the newly formed bone in the defect area at 3 and 6 months after the surgery. RESULTS: The bone formation rate obtained from the skull tissue in MSCs group was significantly higher than that in control group at 3 months (P < 0.01) and 6 months (P < 0.05) after the surgery. The apoptosis rate in the MSCs group was significantly higher at 3 months after the surgery (P < 0.05) and lower at 6 months after the surgery (P < 0.01) than those in the normal group. CONCLUSIONS: Combining bone collagen matrix with hUC-MSCs promoted the new bone regeneration in the rabbit alveolar process cleft model through promoting osteoblasts formations and chondrocyte growth, and inducing type I collagen formation and BMP-2 generation.

Association of BCL-2 polymorphism with the presence and severity of lumbar disc degeneration in the Chinese Han population.

BACKGROUND: Apoptosis is involved in the mechanism of lumbar disc disease (LDD). BCL-2 has been shown to play an anti-apoptosis role. The present study aims to examine the association of -938C > A polymorphism of the BCL-2 gene with the presence and severity of LDD in the Chinese Han population. METHODS: This study consisted of 325 patients with LDD and 236 normal controls. The grade of disc degeneration was determined according to Schneiderman's classification for MRI. -938C > A polymorphism was determined by "slow-down" polymerase chain reaction (PCR) method. RESULTS: The genotype frequency of -938C > A polymorphism was consistent with Hardy-Weinberg equilibrium (p = 0.136). Higher frequencies of -938CA and AA genotypes were found in patients with LDD compared with normal controls (p = 0.019). Furthermore, there were higher frequencies of the A allele in LDD patients than in normal controls (p = 0.005). Unconditional logistic regression analysis revealed that -938CA and AA genotypes were significantly associated with the presence of LDD compared with CC genotype (p = 0.041; OR 1.449; 95% CI 1.015 - 2.067 and p = 0.015; OR 2.102; 95% CI 1.158 - 3.813, respectively). The A allele was significantly associated with the susceptibility to LDD compared with the C allele (p = 0.005; OR 1.436; 95% CI 1.113 - 1.851). In addition, -938CA and AA genotypes, as well as the A allele were found to be associated with the risk for higher degenerative grades of LDD compared with the CC genotype and C allele, respectively (p = 0.017 and p = 0.003, respectively). CONCLUSIONS: The -938C > A polymorphism of BCL-2 may be associated with the presence and severity of LDD in the Chinese Han population.

Newborn screening and genetic variation of medium chain acyl-CoA dehydrogenase deficiency in the Chinese population.

OBJECTIVES: Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is an autosomal recessive disorder of the fatty acid oxidative metabolism. This study aimed to investigate the epidemiological characteristics, the spectrum of variation, clinical phenotype, and prognosis of MCADD in Chinese newborns. METHODS: We retrospectively analysed newborn screening (NBS) data in the Zibo area from January 2016 to March 2022 and summarized 42 cases recently reported in Chinese neonates. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and next-generation sequencing (NGS) were used to detect the concentrations of carnitine in the blood spots and for diagnosis. RESULTS: A total of 183,082 newborns were detected, and six patients were diagnosed with MCADD (1/3,0514). The primary octanoylcarnitine (C8) and the octanoylcarnitine/decanoylcarnitine ratio (C8/C10) were elevated in all patients. Gene analysis revealed four known and four novel variants of the ACADM gene. Five patients were asymptomatic and developed normally under dietary guidance. One child died of vaccination-induced MCADD, presenting with hypoglycemia and elevated acylcarnitines. CONCLUSIONS: The incidence of MCADD in Chinese newborns varies geographically from 1/222,903 to 1/30,514, and the most common pathogenic variant is c.449_452 del CTGA (p. T150Rfs∗4) in ACADM gene with a frequency of 27.7%. HPLC-MS/MS and genetic analysis are beneficial for early prevention and good prognosis of MCADD.

Active bone material containing modified recombinant human bone morphogenetic protein-2 induces bone regeneration in rabbit spina bifida.

This study focuses on spina bifida, which is a high incidence among the current clinical manifestations of human birth defects. Because in the treatment of bone defects, the source of autologous bone is limited and it is easy to cause secondary injury to the patient. At the same time, since the bone tissue in animals needs to perform a variety of biological functions, its complex structure cannot be replaced by a single material. Therefore, in this study, we used Japanese white rabbits to establish an animal model similar to human congenital spina bifida. The established animal model is used to screen the best regenerative repair products for the treatment of congenital spondylolisthesis defects, and to evaluate the safety of regenerative repair products. The results show that bone morphogenetic protein (BMP)-2 combined with collagen material has a better regeneration effect than collagen material alone, and it did not negatively affect the health of animals. This study is not only suitable for the screening of large-scale biomaterials, accelerating the research progress of regenerative repair products, but also conducive to the research on the mechanism of regeneration and repair of various materials.

Genetically engineered FGF1-sericin hydrogel material treats intrauterine adhesion and restores fertility in rat.

Endometrial injury can cause intrauterine adhesions (IUA) and induce the formation of endometrial fibrosis, leading to infertility and miscarriage. At present, there is no effective treatment method for severe IUA and uterine basal injury with adhesion area larger than one-third of the uterus. In this study, we prepared FGF1 silk sericin hydrogel material (FGF1-SS hydrogel) to treat endometrial injury and prevent endometrial fibrosis. Compared with the silk sericin hydrogel material (WT-SS hydrogel), FGF1-SS hydrogel significantly promotes the cell migration and infiltration ability of endometrial stromal cells (ESCs). More importantly, FGF1-SS hydrogel can release FGF1 stably for a long time and inhibit the ESCs injury model forms fibrosis through the TGF-ß/Smad pathway. In the IUA rat model, FGF1-SS hydrogel treatment effectively restored the number of uterine glands and uterine wall thickness in rats, with a fertility rate of 65.1% ± 6.4%. The results show that FGF1-SS hydrogel is expected to be a candidate to prevent IUA.

Differences in Immunological Landscape between EGFR-Mutated and Wild-Type Lung Adenocarcinoma.

Recent clinical trials of lung adenocarcinoma with immune checkpoint inhibitors revealed that lung adenocarcinoma patients with EGFR mutations have a poor response to immunotherapy. However, the mechanisms have not been addressed. We performed immunohistochemistry analyses of resected lung adenocarcinoma tissues with and without EGFR mutations to investigate and compare the characteristics of the tumor microenvironment (TME). We retrospectively enrolled a total of 323 lung adenocarcinoma patients (164 had EGFR mutations), and their corresponding tissue samples were analyzed by the EGFR mutation test and immunohistochemistry. We selected the markers of the immune checkpoint molecule (PD1, PD-L1, and LAG-3) and immune cell (CD3, CD4, CD8, and Foxp3) as markers of the tumor microenvironment. Our results revealed that patients had a distinct tumor microenvironment between EGFR-mutant and wild-type lung adenocarcinomas; the expression of CD3, CD4, PD-L1, and Foxp3 in EGFR-mutant tumors was significantly higher than that in wild-type tumors, while the expression of LAG3 and PD-1 showed a positive correlation with EGFR-wild-type tumors. In survival analysis, EGFR-wild-type patients had longer disease-free survival (DFS) than EGFR-mutant patients (P = 0.0065). Our research demonstrates significant differences in tumor microenvironment composition between EGFR-mutant and wild-type patients. Our findings provide novel evidence that contributes to understanding the mechanism underlying the poor efficacy of immune checkpoint inhibitors.

Repair of alveolar cleft bone defects in rabbits by active bone particles containing modified rhBMP-2.

Objective: A model of alveolar cleft phenotype was established in rabbits to evaluate the effect of active bone particles containing modified rhecombinant human BMP-2 on the repair of the alveolar cleft. Methods: 2-month-old Japanese white rabbits were selected and randomly divided into four groups: normal, control, material and BMP groups. Blood biochemical analysis, skull tomography (microfocus computerized tomography), and histological and immunohistochemical staining analysis of paraffin sections were performed 3  and 6 months after operation. Results: Both types of collagen particles showed good biocompatibility and promoted bone regeneration. The effect of active bone particles on bone repair and regeneration was better than that of bone collagen particles. Conclusions: Active bone particles containing modified rhecombinant human BMP-2 can be used for incisors regeneration.

[The expression of melatonin MT1 receptor in acute necrotizing pancreatitis rats and the protective effects of melatonin].

OBJECTIVE: To investigate the expression of melatonin MT1 receptor in rats with acute necrotizing pancreatitis (ANP) and the protective effects of melatonin (MT) pre-intervention for the pancreas. METHODS: Fifty-four male Sprague-Dawley (SD) rats were randomly divided into three groups: sham-operation group, ANP group and MT-pretreated group. The models of ANP were induced by retrograde injection sodium taurocholate into the bili-pancreatic duct. MT group undergoing intraperitoneal injection 50 mg/kg 30 minutes before the establishment of ANP models. Four, 8 and 12 hours after the onset of operation, the levels of serum amylase and pathological changes of the pancreas were observed. The contents of malondialdehyde (MDA), superoxide dismutase (SOD) and tumor necrosis factor-alpha (TNFα) in the pancreas were measured. The expression of MT1 protein and MT1 mRNA in pancreas were separately analyzed by immunohistochemistry and real-time PCR. RESULTS: (1) Pancreatic pathological damage in ANP groups was progressive exacerbated. It was obviously ameliorated in MT group as compared with ANP group (P < 0.05); (2) Compared with SO group, the levels of serum amylase, MDA and TNFα in the pancreas were significantly increased in ANP group (P < 0.05 or P < 0.01). They were markedly decreased in MT group as compared with ANP group [12 h, (2348.00 ± 278.90) U/L vs (3194.83 ± 538.10) U/L, (2.255 ± 0.472) µmol/L vs (2.960 ± 0.722) µmol/L, (102.929 ± 29.399) ng/L vs (378.544 ± 183.454) ng/L, P < 0.05]. The level of SOD was decreased in ANP group compared with SO group (P < 0.05) and increased in MT group [12 h, (11.448 ± 1.594) U/L vs (8.427 ± 1.950) U/L, P < 0.05]; (3) Compared with SO group, the expression of MT1 protein and MT1 mRNA in ANP group were down-regulated as the severity of the disease increased (P < 0.05). They were significantly higher in MT group than ANP group. CONCLUSIONS: Melatonin pre-intervention is able to increase SOD level and decrease MDA, TNFα levels, thereby reducing pancreatic injury. The MT1 might play an important role in the pathogenesis of ANP. MT might exert protective effects for the pancreas in ANP rats through increase the expression of MT1.

Comparison of three surgical models of bone tissue defects in cleft palate in rabbits.

OBJECTIVE: Cleft palate is one of the most common craniofacial birth defects in the maxillofacial region. There is an urgent need in tissue regeneration research to establish animal models that faithfully mimic human diseases. Here, we compared three surgical models of bone tissue defects in cleft palate in rabbits in order to screen for the biomaterials that induced optimal bone regeneration. DESIGN: Rabbits were used to establish the models of hard palate cleft, alveolar cleft, and alveolar process cleft. Eight weeks following surgery, bone tissue self-healing capacity was estimated by macroscopic appearance and calculating the area of defective bone tissue. The dimensions of the upper jaw in left and right sides were measured at zero and eight weeks. RESULTS: Bone defects in three types of cleft palate models were made at the positions of the hard palate, alveoli and alveolar process. After 8 weeks, when the hard palate was partially excised, it underwent self-healing. When the hard palate was completely excised, it underwent partial self-healing. However, in the models of alveolar cleft and alveolar process cleft, there was no significant self-healing in the bone tissues. The dimensions of the upper jaw in left and right sides were no significant differences in three types of cleft palate models. CONCLUSIONS: Bone defects in the alveolar and alveolar process clefts exhibit a diminished capability for self-healing. This study may provide valuable information for the screening of materials that induce bone regeneration.

[Mechanism of liver injury in severe acute pancreatitis rats and role of melatonin].

OBJECTIVE: To investigate the activation level of nuclear factor-kappaB (NF-kappaB) in liver injury caused by severe acute pancreatitis (SAP) and the protective role of melatonin against liver injury. METHODS: Ninety-six Sprague-Dawley (SD) rats were randomly divided into 3 equal groups: SAP group undergoing injection of sodium taurocholate to establish SAP models, melatonin (Mel) treatment group undergoing intraperitoneal injection 50 mg/kg 30 minutes before the establishment of SAP models, and sham operation group (Sham group). 4, 12, 24, and 48 hours after the onset of operation, blood samples were collected from the inferior vena casa of 8 rats from each group to measure the serum level of amylase (AMY) and alanine transaminase (ALT) by iodine colorimetry, and to detect the serum level of tumor necrosis factor-alpha (TNF-alpha) by ELISA. The livers were taken out to undergo pathological examination. Immunohistochemistry was used to examine the percentage of nuclear factor (NF)-kappaB in the hepatocytes. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) was used to determine the extent of hepatic apoptosis. RESULTS: The AMY and ALT levels at different time points of the SAP and Mel subgroups were all significantly higher than those of the sham operation subgroups (all P<0.05), and the AMY and ALT levels at different time points of the Mel subgroup were all significantly lower than those of the SAP subgroups (all P<0.05). The liver NF-kappaB activation level and hepatocellular apoptosis index of the SAP group increased since the fourth hour after the operation, and peaked at the time point of 24 hour, all significantly higher than those of the sham operation group (all P<0.05), and then declined. The TNF-alpha level at the time points of 12, 24, and 48 h in the SAP group were all significantly higher than those of the other 2 groups (all P<0.05). The levels of TNF-alpha, AMY, and ALT, the activity of NF-kappaB, and the extent of hepatocellular apoptosis at any time points of the Mel group were all significantly lower than those of the SAP group, but significantly higher than those of the sham operation group. Microscopy showed that the liver pathological damages of the Mel group were milder than those of the SAP group. CONCLUSION: SAP with liver injury is associated with the hepatic NF-kappaB activation leading to the production of NF-kappaB dependent cytokines and chemokines such as TNF-alpha. Melatonin reduces the apoptosis and necrosis in liver by inhibiting the activity of NF-kappaB and decreasing the expression of TNF-alpha.