A histological and biomechanical study of bone stress and bone remodeling around immediately loaded implants

Immediate loading(IL)increases the risk of marginal bone loss.The present study investigated the biomechanical response of peri-implant bone in rabbits after IL,aiming at optimizing load management.Ninety-six implants were installed bilaterally into femurs of 48 rabbits.Test implants on the left side created the maximal initial stress of 6.9 and 13.4 MPa in peri-implant bone and unloaded implants on the contralateral side were controls.Bone morphology and bone-implant interface strength were measured with histological examination and push-out testing during a 12-week observation period.Additionally,the animal data were incorporated into finite element(FE)models to calculate the bone stress distribution at different levels of osseointegration.Results showed that the stress was concentrated in the bone margin and the bone stress gradually decreased as osseointegration proceeded.A stress of about 2.0 MPa in peri-implant bone had a positive effect on new bone formation,osseointegration and bone-implant interface strength.Bone loss was observed in some specimens with stress exceeding 4.0 MPa.Data indicate that IL significantly increases bone stress during the early postoperative period,but the load-bearing capacity of peri-implant bone increases rapidly with an increase of bone-implant contact.Favorable bone responses may be continually promoted when the stress in peri-implant bone is maintained at a definite level.Accordingly,the progressive loading mode is recommended for IL implants.     

Intracellular levels of calmodulin are increased in transformed cells

By using Hoechst 33342,rabbit anti calmodulin antibody,FITC-labeled goat anti rabbit IgG and SR101(sulfo rhodamine 101)simultaneously to stain individual normal and transformed cells,the microspectrophotometric analysis demonstrated that 3 markers which represented the nucleus,calmodulin and total protein respectively,could be recognized in individualj cells without interference,The phase of the cell cycle was determined by DNA content(Hoechst 33342),We found that in transformed cells(NIH3T3) tsRSV-LA90,cultured at 33℃ and transformed C3H10T1/2 Cells),the ration of calmodulin to total protein (based on the phases of cell cycle)was higher than that in normal cells (NIH3T3 tsRSV-LA90 cells,cultured at 39℃ and C3H10T1/2 cells)in every cell cycle phase,This ration increased obviously only from G1 to S phase in either normal or transformed cells.The results showed that calmodulinreally increased during the transformation,and its increase was specific.In the meantime when cells proceeded from G1 to S.the intraceollular calmodulin content also increased specifically.     

MYCOLOGY IN CHINA WITH EMPHASIS ON REVIEW OF THE ANCIENT LITERATURE

<正> Ⅰ.Ancient Literature ReviewThe edibility and medicinal use of fungi were known to Chinese ancestors long,long ago.Our fathers recognized and used them as food,as medicine,in agriculture,in industry,for fermentation,etc.Fungi such as common mushrooms,wood ear,jellyfungus(Tremella fusiformis)have been used for food;china root(Poria coccus),ca-     

The association between HLA alleles (A, B, DRB1) and HIV-1 infection/ AIDS progression in the Han Chinese population of Hubei province

The association between HLA alleles (A, B, DRB1), haplotypes and AIDS progression in HIV-1 infected patients was investigated by analyzing and comparing the differences gene frequencies of HLA alleles (A, B, DRB1) and haplotypes in HIV-1 infected and AIDS individuals in Hubei province of China. Four hundred and twenty- four HIV-1 seropositive individuals were divided into two groups: HIV-1 infected group and AIDS patient group, according to diagnostic criteria. HLA-A, B, and DRB1 allele typing was performed using polymerase chain reaction-sequence-specific oligonucleotide (PCR-SSOP) and polymerase chain reaction-sequencing based typing (PCR-SBT) techniques. Our study revealed that B*57:01 seemed resistant to AIDS progression, and the presence of DRB1*04:05 was associated with a poor disease outcome in HIV-1 infection. These associations were independent of age, sex, and transmission route of the host. No association was observed between HLA-A, B, DRB1 homozygotes, HLA-Bw4, Bw6 serological types and AIDS progression. We concluded that HLA gene polymorphism has a significant role in HIV-1 infection/AIDS progression. This observational study may open up avenues for precision medicine in the personalized prevention and treatment of AIDS.     

不同预处理方法对大麦花药-花粉培养的影响

研究了甘露醇预处理的适应性以及pH值对甘露醇预处理效果的影响;并首次将山梨醇预处理应用到大麦花药培养中,获得理想的实验结果。第一,采用甘露醇预处理, 17种材料平均愈伤组织诱导率为20.67块/花药,绿苗产量为2.46株/花药。第二,甘露醇预处理溶液的pH值不同,其预处理的效果也不同。其中,愈伤组织诱导率和绿苗产量均以pH5.6最高。第三,不同浓度(0.1-0.5mol/L)的山梨醇预处理3天绿苗产量差异不显著;但同一浓度(0.3mol/L)山梨醇预处理不同天数(1-7天)绿苗产量差异极显著,以3天处理效果最好,绿苗产量是对照的51.2倍。     

130例智力低下儿童脆性X检测报告

本文采用脆性 X检测技术对130例先天性智力低下儿童进行了细胞遗传学研究,结果共发现27例具有染色体异常。其中t(5;15)及t(8;12),inv(9)两例核型,经鉴定为世界首报核型;检出5例脆性X综合征,检出率为3.77%,占异常核型的18.5%。 Abstract:The cytogenetic study was made on 130 mentally retarded children with the technique of Fra(X) detection.Among the 27 mentally retarded children with chromosomal abnormalities found in the study,the two karyotypes of t (5;15) and t (8;21),inv(9) were first reported in the literature.of the 130 mentally retarded cases,5 had fragile (X) syndrome (3.77%).The syndrome accounted for 18.5% in the abnormal karyotypes.     

油用向日葵主要农艺性状的遗传分析

对10个油用向日葵品种的主要农艺性状进行遗传分析的结果表明,株高、单株粒数、百粒重、盘径和单株粒重等农艺性状具有较大的遗传率,可以在早代单株选择或直接选择;出苗-现蕾、现蕾-开花、开花-成熟、皮壳率等性状的遗传率较低,应根据各性状间相关关系进行间接选择或将选择推迟到晚期世代进行。遗传变异幅度较大的性状有皮壳率、单株粒数、小区产量、单株粒重等。由于性状的遗传改良效果主要由该性状的遗传率和变异幅度及选择强度所决定,因此,在选择率确定为5%情况下,遗传改良效果较好的性状为单株粒数和单株粒重。 Abstract:The genetic analysis of main agronomic characters was conducted with 10 varieties of oil sunflower(Helianthus annuus L.).The results showed that direct selection can be carried out at early generation for characters with higher heritability such as plant height,grain number pere plant,100-grain weight,diameter of disc and grain weight per plant.For maturity and percentage of shell with lower heritability,indirect selection correlated with other characters or late generation selection can be utilized.The characters showing wide genetic variation were those as percentage of shell,grain number per plant,grain yield per plot and grain weight.Since the successful improvement of a character mainly depends on its heritability,variation of heritability and intensity of selection,we suggest that the characters which may give better genetic improvement are grain number and grain weight per plant under condition of 5% selection pressure.     

猫叫综合征一家系高分辨染色体分析

本文采用高分辨染色体技术,对一例猫叫综合征患儿及其家系进行了分析,结 果提示,猫叫综合征染色体关键片段位于5p15.3→5pter。     

Dedifferentiating initiation and embryogenesis from freshly-isolated microspores of barley

By using DNA-specific fluorescent dye and a confocal laser scanning microscope, the present study was designed to investigate the cytological characteristics of dedifferentiating initiation during pretreatment and em-bryogenesis during culture in freshly-isolated microspores of barley, and the difference in main developmental pathway between freshly-isolated and cold-treated microspores. The results revealed that ( i ) freshly-isolated microspores started the initiation within 12 h of mannitol pretreatment, whose main cytological characteristics were that: cell vol-ume was obviously extended; the volume of nuclei and nucleoli were also greatly increased; nucleoli were extremely clear and highly condensed; N/C ratio was very high; ( ii ) all the pretreatment methods led to the initiation of the mi-crospores, thus triggering the embryogenic process; ( iii ) pretreatment methods influenced the main developmental pathway of microspores by changing the pattern of the first mitosis. The cold-treated microspor