Effect of a novel radio-frequency atmospheric-pressure glow discharge plasma jet treatment on crosslinking of dentin collagen / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effect of a noval radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet on crosslinking of dentin collagen.@*METHODS@#(1) Twenty intact third molars were collected. The middle dentin discs were prepared for each tooth by low-speed water-cooled Isomet saw, and then immersed in 10% (mass fraction) H3PO4 solution for 16 h to obtain fully demine-ralized dentin collagen. The twenty dentin discs were then randomly divided into five groups. The control group was untreated while the four experimental groups were treated by plasma jet with gas temperature of 4 ℃ for different times (20 s, 30 s, 40 s, and 50 s). The structure and crosslinking degree of dentin collagen were characterized by attenuated total reflection-Fourier transform infrared spectroscopy. The surface morphology of demineralized dentin was observed by scanning electron microscope, and the microstructure was observed by transmission electron microscope. (2) Fourty non-caries third molars were collected to prepare 5 g fine dentin powder, then completely demineralized with 10% H3PO4 solution. The control group was untreated, while the four experimental groups were treated by plasma jet for 20 s, 30 s, 40 s and 50 s. The crosslinking degree of each group was determined by ninhydrin colorimetric method. (3) Forty intact third molars were collected to obtain dentin strips. Only two central symmetrical dentin strips (nasty 80) were taken from each tooth and immersed in 10% H3PO4 solution for 16 h to obtain fully demineralized dentin collagen. Eighty dentine collagen fiber strips were randomly divided into five groups. The control group was untreated and the axial surfaces of dentin collagen fiber strips in the expe-rimental groups were treated with the plasma jet for 20 s, 30 s, 40 s and 50 s. The ultimate tensile strength of dentin was measured by universal mechanical machine.@*RESULTS@#(1) The surface morphology of demineralized dentin observed by scanning electron microscope showed that the network structure of collagen fibers on the surface of demineralized dentin treated with the plasma jet for 20 s, 30 s and 40 s could maintain the uncollapsed three-dimensional structure, and part of the microstructure was destroyed after plasma jet treated for 50 s. After being treated by plasma jet for 20 s, 30 s and 40 s, the three-dimensional structure was uncollapsed, and the typical periodic transverse pattern of natural type Ⅰ collagen fiber could be seen. The results of infrared spectra showed that the secondary conformation of dentin collagen fibers was the same as that of the control group after being treated with the plasma jet, and the intensity of amide band was significantly increased after being treated for 30 s and 40 s. (2) The results of ninhydrin crosslinking test showed that the crosslinking ratio of dentin collagen treated by plasma jet for 30 s and 40 s was the highest, and the difference was statistically significant (P < 0.05). (3) The results of dentin ultimate tensile strength showed that the control group was (1.67±0.24) MPa, and the plasma jet treated 20 s, 30 s, 40 s and 50 s groups were (4.21±0.15) MPa, (7.06±0.30) MPa, (7.32±0.27) MPa, and (6.87±0.17) MPa, which were significantly different from that of the control group (P < 0.05).@*CONCLUSION@#The novel RF-APGD plasma jet treatment can promote the crosslinking degree of demineralized dentin collagen and improve their ultimate tensile strength.

Acupuncture adjuvant treatment for dysphagia in patients with Parkinson's disease: a randomized controlled trial / 中国针灸

OBJECTIVE@#To observe the effect of acupuncture on swallowing function and nutritional status of patients with Parkinson's disease (PD) dysphagia.@*METHODS@#A total of 56 patients with PD dysphagia were randomly divided into an observation group and a control group, 28 cases in each one. Both groups were given conventional treatment and swallowing function rehabilitation training.On the basis, the observation group was treated with acupuncture (filiform needling and tongue picking acupuncture). The acupoints of filiform needling were Lianquan (CV 23), Shanglianquan (Extra), Yifeng (TE 17), etc.; and the tongue picking acupuncture was applied at Jinjin (EX-HN 12), Yuye (EX-HN 13) and posterior pharyngeal wall. Rehabilitation training and acupuncture were performed once a day for 5 consecutive days a week, 2 weeks as a course of treatment, 3 courses in total. The swallowing function [oral transit time (OTT), swallowing response time (SRT), pharyngeal transit time (PTT), laryngeal closure duration (LCD)] and nutritional indexes [body mass index (BMI), serum albumin (ALB), serum prealbumin (PA), hemoglobin (Hb)] in the two groups were evaluated before and after treatment, and the clinical effects were compared.@*RESULTS@#After treatment, the paste and liquid OTT, SRT, PTT, LCD in the two groups were shorter than those before treatment (@*CONCLUSION@#Acupuncture-assisted rehabilitation training can improve the swallowing function and nutritional status in patients with Parkinson's disease swallowing disorders.

Effect of different plasma treated zirconia on the adhensive behaviour of human gingival fibroblasts / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effect of different cold atmospheric plasma (CAP) treatment on the surface chemical and physical properties of zirconia and adhensive behaviour of human gingival fibroblasts (HGFs) cultured on zirconia disks.@*METHODS@#The zirconia disks were divided into four groups and treated using helium, argon and mixture of argon and oxygen cold atmospheric plasma for 90 s or left untreated. The surface morphology, wettability and chemical elements were analyzed right after treatment. Human gingival fibroblasts were grown from biopsies obtained from a periodontally healthy human subject during periodontal surgery. HGFs were seeded on zirconia disk, and cells density was measured at the time point of 3 hours. Indirect immunofluorescence (IIF) was performed for morphometric examination at the time point of 3 hours.@*RESULTS@#The crystallographic structure of zirconia was analyzed previously and the results suggested that it fitted the properties of zirconium yttrium oxide. After helium, argon and mixture of argon and oxygen cold atmospheric plasma treatment, the surface morphology and roughness of zirconia disks remained the same. The contact angle of zirconia decreased significantly(P<0.05)after CAP treatment: from 68.38° to 17.90°. After different CAP plasmas treatment, the atomic percentage of carbon on the outermost surface of the three groups decreased, as did the surface C/O ratio. The surface C/O ratio of zirconia decreased from 1.07 to 0.33. Fibroblasts density increased on CAP treated disks, especially the ones treated by mixture of argon and oxygen CAP(P<0.05). Cells of the three CAP plasma treatment groups spread better and had more protrusions, as well as larger surficial areas.@*CONCLUSION@#Based on the results of this study after being treated by different kinds of CAP plasmas for 90 s, the surface wettability increased and the elements changed significantly with no changes in the tomography and roughness of the materials. The CAP treatment enhances the adhensive behavior of fibroblasts on zirconia by increasing the oxygen functional groups and promoting the cell density. Wettability of zirconia, an important physicochemical property, has a vital influence on the cell behaviors.

Effect of a novel cold atmospheric plasma jet treatment with different temperatures on resin-dentin bonding / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effect of different treatment temperatures of a novel cold atmospheric plasma jet treatment on the resin-dentin bonding.@*METHODS@#(1) Fifty-two freshly extracted, non-carious and intact third molars were collected. The occlusal one-third of the crown was removed by means of a water-cooled low-speed Isomet saw. One dentin disc [(900 ±100) μm] was prepared for each tooth. The fifty-two dentin discs were randomly divided into control group and experimental groups, of which four were in control group, and forty-eight were divided into four experimental groups according to the different treatment temperatures (4 °C, 10 °C, 20 °C and 30 °C) of the novel radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet, twelve in each group. Each experimental group was divided into three subgroups according to different treatment time (10 s, 20 s and 30 s), with four in each subgroup. The occlusal one-third of the crown was removed by means of a water-cooled low-speed Isomet saw. The morphology of demineralized dentin surfaces was analyzed using field emission scanning electron microscopy. (2) Twenty unerupted, non-carious and intact third molars were randomly divided into five groups, four in each group: control group, untreated; 4 °C, 10 °C, 20 °C and 30 °C experimental groups, each group was treated with the RF-APGD plasma jet for 20 s. The micro-tensile resin dentin bond strength was tested after 20 s RF-APGD plasma jet treatment with different temperatures, using a universal mechanical machine.@*RESULTS@#(1) The field emission scanning electron microscopy results indicated that when compared with the control group, a 10 s RF-APGD plasma jet treatment with 30 °C and 20 °C collapsed the collagen scaffold. Collagen fibrils maintained an uncollapsed three-dimensional structure after the 4 °C RF-APGD plasma jet treatment for even 30 s treatment. (2) The microtensile resin dentin bond strength results of the 4 °C RF-APGD plasma jet treatment group (57.8±0.7) MPa were significantly higher than that of the control group [(47.4±0.5) MPa] and 10 s, 20 s and 30 s RF-APGD plasma treatment group [(51.9±0.7) MPa,(29.7±1.0) MPa and (22.2±1.5) MPa] with statistically significant difference (P<0.05). Compared with the control group, the micro-tensile bond strength increased about 21.9% and 9.5% after 4 °C and 10 °C RF-APGD plasma jet treatment, respectively.@*CONCLUSION@#Compared with other treatment temperatures, this novel RF-APGD plasma jet treatment with the temperature of 4 °C can preserve the three-dimensional morphology of demineralized dentin better, and can improve the resin-dentin bonding.

Genetic analysis of the nonstructural gene (NS1) of H9N2 avian influenza viruses isolated in China / 病毒学报

The nonstructural genes (NS1) of nine H9N2 subtype avian influenza viruses isolated from diseased chickens on different farms during 1998-2005 were amplified by RT-PCR and completely sequenced. The nucleotide and deduced amino acid sequences of NS1 genes of these isolates were compared. The results showed that NS1 genes of all H9N2 isolates contained 654 bp and encoded 217 amino acids. The homologies of the nucleotide and deduced amino sequences of the isolates were 95.4%-99.8% and 93.6%-100%, respectively. Comparison of the amino acid sequences of NS1 proteins of these isolates with other H9N2 viruses demonstrated that NS1 proteins of the nine strains had a deletion of 13 amino acid residues at the carboxyl terminus, which may be the molecule mark of the isolates in mainland China. Phylogenetic analysis revealed that the NS1 genes of these isolates fell into the same lineage and belonged to allele A. Eight out of nine isolates belonged to the CK/SH/F/98-like lineage while only Ck/HN/A3/98 strain belonged to the Ck/HK/Y280/97-like linease. All the isolates were derived from Ck/BJ/1/94 strain which was the first isolate is mainland China in 1994. The results indicated that H9N2 subtype AIV appeared differentiation following the passage of time and the viruses belonging to Ck/SH/F/98-like acquired an epidemic spread advantage in chicken population in mainland China.

Clinicopathological significance of homeobox BP1 mRNA expression in lung cancer tissue / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of beta-protein 1 (BP(1)) gene, a novel member of DLX homeobox gene family, in lung cancer tissue and its relationship with clinical features of lung cancer.</p><p><b>METHODS</b>RT-PCR was employed for detecting BP(1) gene expression in the lung cancer tissues, adjacent tissues, non-cancer lung tissues of 46 lung cancer patients.</p><p><b>RESULTS</b>Thirty-six lung cancer tissues and 6 adjacent tissues but none of the normal tissues were found to have BP(1) gene overexpression, showing significant difference in BP(1) expression between the tissues (P<0.01). Significant difference in BP1 gene overexpression was noted between well differentiated cancers (13 of out 21) and poorly differentiated cancers (22 of the 25), but not between cancers of different stages or between squamous carcinoma and adenocarcinoma.</p><p><b>CONCLUSION</b>BP(1) gene expression is up-regulated in human lung cancer in related to the differentiation level of lung cancer but not to the clinical stage.</p>