BACKGROUND:Physical structure and inorganic composition of composite calcium phosphate bone implants are similar to human bone, and the implants have good bioabsorbable ability and biocompatibility. Studies have confirmed that Dipsacus powder can significantly improve the speed of bone defect repair.
OBJECTIVE:To study the effects of Dipsacus asperoides/composite calsium phosphate bone implant material in the repair of bone defects.
METHODS:Bone defects of 1.0 cm×0.5 cm×0.3 cm were made on the bilateral mandibular bodies. The right side was implanted with Dipsacus asperoides/composite calsium phosphate bone implant as experimental group and the left side implanted with calcium phosphate bone material served as control group. Samples were col ected at 4, 8, 12 weeks after implantation for gross observation, cone beam CT, scanning electron microscope observation and histological observation.
RESULTS AND CONCLUSION:(1) Gross observation:the osteogenic speed, degradation rate and hardness in the experimental group were higher than those in the control group. (2) Cone beam CT detection:the implant in the experimental group was more tightly integrated with the surrounding tissues than that in the control group, and the degradation speed in the experimental group was higher than that in the control group. (3) Scanning electron microscope observation:there were many fibrous connective tissues between the implants and the surrounding tissues in the two groups, which was more obvious in the experimental group than the control group. With time gone, the implants were combined with the surrounding tissues more tightly. (4) Histological observation:the osteogenic speed and activity in the experimental group were superior to those in the control group. These findings indicate that Dipsacus asperoides combined with composite calcium phosphate bone implant can accelerate bone repair.

BACKGROUND:Studies have confirmed that the nano-hydroxyapatite/chitosan/alginate composite materials have a certain flexibility and strength and possess a bioactivity similar to human bone.
OBJECTIVE:To explore the effect of the nano-hydroxyapatite/chitosan/alginate composite materials on the repair of rabbit mandible defects.
METHODS:Bilateral mandibular defect models of 10 mm × 5 mm × 5 mm were made in 18 healthy New Zealand white rabbits. Then, the rabbits were divided into two groups:experimental group was implanted with nano-hydroxyapatite/chitosan/alginate composite material, and control group was implanted with hydroxyapatite/chitosan composite. At 4, 8 and 12 weeks after implantation, cone-beam CT was applied to observe implant degradation, cal us growth and bone connection in the defect area;new bone formation was observed by hematoxylin-eosin staining.
RESULTS AND CONCLUSION:The gray values of the bone density in the experimental group and control group gradual y increased with time, and there were remarkably significant differences between the two groups at different time points (P<0.01). At the same time point, the experimental group was superior to the control group in gross observation, cone-beam CT observation, gray value of CT and histological observation (P<0.05). At 4-8 weeks after implantation, the implant materials in the two groups were gradual y degraded with a blurred junction between the defect and bone tissue, and a smal amount of new bone formed tightly integrated to the recipient bone tissue, in which the experimental group was more significant. And during 8 to 12 weeks, the degradation of implanted materials in the two groups was basical y complete, and the implant began to merge with the recipient bone tissue, with further generation of new bone tissue and gradual repair of bone defect area, in which, the experimental group was more obvious. Results show that the nano-hydroxyapatite/chitosan/alginate can repair bone defects effectively, and promote the new bone formation.

Objective To demonstrate that heme oxygenase (HO) isoforms exist in rat spleen treated with hematin and phenylhydrazine and to confirm that the isolated cDNA actually encodes HO-1 by expressing cDNA in monkey kidney cells (COS-1 cells ) in order to prepare HO-1 mutant for inhibiting the natural enzyme.Methods The rat spleen microsomal fractions were first purified by diethylaminoethyl (DEAE)-Sephacel and hydroxylapatite. The activity of two isoforms (HO-1 and HO-2) of enzyme and their apparent molecular weight on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) were measured. Secondly, using the isolated HO-1 cDNA clone, the expression plasmid pcDNA3HO1 was constructed and transfected into cultured COS-1 cells. The transfected cells were collected and disrupted by sonication, and the microsomes were prepared by ultracentrifugation. The activity of HO-1 was measured.Conclusion The activity of expressed HO-1 in COS-1 cells is higher than that of purified enzyme from rat spleen tissue. It is suggested that this clone having an insert of 1030 base-pairs encodes HO-1 and that we can prepare HO-1 mutant by site-directed mutagenesis of HO-1 cDNA to prevent and treat hyperbilirubinemia.

Objective:To analyze the status of neonatal respiratory distress syndrome (RDS) management in 10 hospitals in Northwest China over the past five years and to investigate the strategies for improving the prevention and treatment of RDS.Methods:This retrospective study involved premature infants with RDS who were admitted to the neonatal intensive care units (NICU) of 10 hospitals (six in Shaanxi Province, three in Gansu Province, and one in Xinjiang Uygur Autonomous Region) of the Northwest China Neonatal Collaborative Group within 3 d after birth from January 1 to December 31, 2016, and from January 1 to December 31, 2021. Basic information, perinatal condition, treatment approaches, complications, and prognosis of the patients were compared. T-test, rank sum, and Chi-square tests were used for statistical analysis. Result:(1) This study enrolled 322 premature infants with RDS in 2016 and 349 in 2021. Premature infants at the gestational age of 30 to 33 weeks were mainly affected, and the majority were male [64.3% (207/322) and 57.3% (200/349)]. The average maternal age in 2021 was older than that in 2016 [(30.6±4.8) years vs (28.6±5.4) years, t=24.02, P<0.001], and the proportion of women at advanced maternal age was also higher in 2021 [19.2% (67/349) vs 12.4% (40/322), χ2=4.18, P<0.05]. (2) The proportions of pregnancies conceived with assisted reproductive technologies [11.7% (41/349) vs 1.9% (6/322), χ2=25.12], underwent routine prenatal examinations [58.5% (204/349) vs 30.4% (98/322), χ2=53.33], exposed to steroids [62.2% (217/349) vs 28.6% (92/322), χ2=82.58] and delivered by cesarean section or elective cesarean section [73.6% (257/349) vs 51.6% (166/322), χ2=35.06; 24.1% (84/349) vs 6.5% (21/322), χ2=39.07], as well as the ratio of cesarean scar pregnancy [7.4% (26/349) vs 3.4% (11/322), χ2=5.23] were all higher in 2021 than those in 2016 (all P<0.05). Moreover, the incidence of fetal distress [30.1% (105/349) vs 20.2% (65/322), χ2=8.68], gestational hypertension [24.6% (86/349) vs 13.0% (42/322), χ2=14.59], premature rupture of membranes [16.0% (56/349) vs 10.2% (33/322), χ2=4.89], meconium-stained amniotic fluid [12.6% (44/349) vs 5.6% (18/322), χ2=9.83], placental abruption [10.3% (36/349) vs 5.3% (17/322), χ2=5.84], gestational diabetes mellitus [10.3% (36/349) vs 1.6%(5/322), χ2=22.41], chorioamnionitis [4.6%(16/349) vs 0.9% (3/322), χ2=8.12], thyroid dysfunction [4.3% (15/349) vs 0.6% (2/322), χ2=7.88] and heart disease [4.3% (15/349) vs 0.3% (1/322), χ2=9.17] were higher in 2021 than in 2016 (all P<0.05). (3) In 2021, the rate of pulmonary surfactant (PS) usage, the dosage of porcine PS, and the proportion of bovine PS usage were all significantly higher than those in 2016 [73.6% (257/349) vs 67.1% (216/322), χ2=11.62; (178.5±38.0) mg/kg vs (165.2±42.8) mg/kg, t=7.85; 47.9% (123/257) vs 19.4% (42/216), χ2=41.72; all P<0.01]. No significant difference in the incidence of intubation-surfactant-extubation (INSURE), early PS administration (≤2 h after birth), or the arterial blood gas values before and after PS treatment was found between the cases enrolled in 2021 and 2016. The duration of antibiotic treatment [7.0 d (5.0-14.0 d) vs 5.0 d (1.0-8.0 d), Z=7.55] and assisted ventilation [144 h (81-264 h) vs 73 h (47-134 h), Z=8.20] and the median hospital stay [24 d(14-42 d) vs 16 d (10-25 d), Z=6.74] were significantly longer in 2021 than in 2016 (all P<0.01). More patients required nasal intermittent positive pressure ventilation [29.6% (100/338) vs 1.0% (3/306), χ2=97.81] and conventional ventilation [42.6% (144/338) vs 30.1% (92/306), χ2=10.87] in 2021 as compared with those five years ago (both P<0.01). (4) In 2021, the incidence of patent ductus arteriosus [15.5% (54/349) vs 6.2% (20/322), χ2=63.40], bronchopulmonary dysplasia [9.2% (32/349) vs 2.8% (9/322), χ2=12.88], persistent pulmonary hypertension [5.4% (19/349) vs 0.6% (2/322), χ2=12.85], periventricular leukomalacia [4.3% (15/349) vs 1.2% (4/322), χ2=7.52] and pneumothorax [3.4% (12/349) vs 0.3% (1/322), χ2=9.68] increased as compared with those in 2016 (all P<0.05), while the incidence of nosocomial infection decreased significantly [7.4% (26/349) vs 19.6% (63/322), χ2=21.37, P<0.001]. (5) The cure rate of premature infants with RDS was 70.8% (247/349) in 2021, which was significantly higher than that in 2016 [56.2% (181/322), χ2=15.37, P<0.001]. Moreover, the rate of withdrawing treatment and the total mortality rate was lower in 2021 than in 2016 [7.7% (27/349) vs 14.3% (46/322), χ2=7.41; in-hospital: 1.4% (5/349) vs 5.6% (18/322), χ2=8.74; out of hospital: 8.3% (29/349) vs 13.7% (44/322), χ2=4.96; all P<0.05]. Conclusions:The clinical management of RDS in premature infants in the involved hospitals has been improved. However, there is room for improvement in prenatal examinations.