[The role of peripheral retinal defocus in myopia progression].

The increasing incidence of myopia has become a global public health concern. Exploring the mechanisms underlying the onset and progression of myopia is crucial for prevention and control. This paper reviews the role of peripheral retinal defocus mechanisms in the development of myopia, with particular emphasis on the interaction between accommodation lag and peripheral retinal defocus, as well as the impact of optical intervention on myopia control effectiveness. In recent years, researchers have developed various optical tools for myopia prevention and control based on the peripheral retinal defocus theory, such as peripheral defocus spectacle lenses, orthokeratology lenses, and peripheral defocus soft contact lenses. This paper aims to provide clinicians with the latest research findings to deepen their understanding of the mechanisms involved in myopia development and to guide the future development and clinical application of myopia prevention and control products.

[Spatial distribution pattern of local tumor progression analysis after microwave ablation of hepatocellular carcinoma based on three-dimensional magnetic resonance imaging].

Objective: To investigate the spatial distribution pattern of local tumor progression (LTP) for hepatocellular carcinoma (HCC) ≤5 cm after microwave ablation. Methods: A retrospective analysis was performed on 169 HCCs with matched MRI before and after ablation from December 2009 to December 2019. A tumor MRI was reconstructed using three-dimensional visualization technology. LTP was classified as contact or non-contact, early or late stage, according to whether LTP was in contact with the edge of the ablation zone and the occurrence time (24 months). The tumor-surrounded area was divided into eight quadrants by using the eight-quadrant map method. An analysis was conducted on the spatial correlation between the quadrant where the ablative margin (AM) safety boundary was located and the quadrant where different types of LTP occurred. The t-test, or rank-sum test, was used for the measurement data. 2-test for count data was used to compare the difference between the two groups. Results: The AM quadrant had a distribution of 54.4% LTP, 64.2% early LTP stage, and 69.1% contact LTP, suggesting this quadrant was much more concentrated than the other quadrants (P < 0.001). Additionally, the AM quadrant had only 15.2% of non-contact type LTP and 17.1% of late LTP, which was not significantly different from the average distribution probability of 12.5% (100/8%) among the eight quadrants (P = 0.667, 0.743). 46.6% of early contact type LTP was located at the ablation needle tip, 25.2% at the body, and 28.1% at the caudal, while the location distribution probabilities of non-early contact LTP were 34.8%, 31.8%, and 33.3%, respectively. Conclusion: LTP mostly occurs in areas where the ablation safety boundary is the shortest. However, non-contact LTP and late LTP stages exhibit the feature of uniform distribution. Thus, this type of LPT may result from an inadequate non-ablation safety boundary.

[Efficacy of one-stage total spondylectomy and circumferential reconstruction for axial tumors through a combined anterior retropharyngeal-posterior approach].

Objective: To elucidate the safety and efficacy of one-stage total spondylectomy and circumferential reconstruction through a combined anterior retropharyngeal-posterior approach for axial tumors. Methods: A total of 20 patients with axial tumor who received total spondylectomy through a combined anterior retropharyngeal-posterior approach in Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology from February 2006 to December 2018 were retrospectively analyzed. Anterior reconstruction was performed with a special-shaped titanium mesh or three-dimensional printed (3DP) implants. The degree of local pain and neurological function was assessed by the visual analogue scale (VAS) and Frankel classification systems, respectively. Status of internal fixation and local recurrence was analyzed by radiological examination during follow-up. Results: Among the 20 patients, 12 were male and 8 were female with a mean age of (59.1±11.0) years (31 to 72 years). The mean operation time was (605.0±60.1) minutes (430 to 700 minutes) with a mean intraoperative blood loss of (1 250±347) ml (800 to 2 400 ml). The mean postoperative hospital stay was (13.2±2.8) days (8 to 20 days), and mean follow-up duration was (37.2±14.2) months(14 to 66 months). Anterior reconstructions were performed with a special-shaped titanium mesh in 14 patients and with 3DP implants in another 6 patients. Posterior occipital-cervical fixation was performed in 5 patients, while cervical fixation only in another 15 patients. The mean VAS score of pain at the last follow-up decreased significantly when compared with that before operation (1.6±0.6 vs 7.1±1.1, P<0.001). Nine patients with neurological deficits indicated significant improvement by at least 1 level at the last follow-up; among them, 2 cases of Frankel B improved to Frankel C and D, respectively; 3 cases of Frankel C all improved to Frankel D, and 4 cases of Frankel D improved to Frankel E. The perioperative complications included: 2 cases of vertebral artery injury, 2 cases of dysphagia, 3 cases of hoarseness and cough, 2 cases of cerebrospinal fluid leakage, and 1 case of greater occipital neuralgia. At the last follow-up, 5 patients died and 3 patients relapsed. Only 1 case suffered fixation failure due to local recurrence at the last follow up. Conclusions: One-stage total spondylectomy and circumferential reconstruction through a combined anterior retropharyngeal-posterior approach is safe and effective for axial tumors with favorable clinical outcomes and minor complications. Circumferential reconstruction with special-shaped titanium mesh or 3DP implant and posterior fixation can effectively reconstruct mechanical stability.

A meta-analysis of prognostic factors of osteosarcoma.

OBJECTIVE: To systemically evaluate the factors influencing the prognosis of osteosarcoma. MATERIALS AND METHODS: Case-control studies (sample size>100) investigating the factors influencing the prognosis of osteosarcoma published from 1st January 1980 to 1st February 2019 were searched in the databases, including PubMed, Embase, and CBM. The meta-analysis was conducted within the Review Manager 5.3 software. RESULTS: 22 studies were included. The 5-year overall survival (OS) of male patients was significantly lower than that of female patients (OR=0.84, 95% CI=0.76-0.93). There was no significant statistical difference in 5-year OS between the adolescent group (≤14 years old) and the adult group (>14 years old) (OR=0.88, 95% CI=0.68-1.14). Before standardized chemotherapy, which was started in 2000, the 5-year OS of patients receiving surgery and chemotherapy was significantly higher than patients only receiving surgery (OR=3.20, 95% CI=2.30-4.46). After 2000, the 5-year OS of patients receiving standardized chemotherapy was significantly higher than those undergoing non-standardized chemotherapy (OR=2.17, 95% CI=1.77-2.67). The 5-year OS of the limb-salvage surgery group was higher than that of the amputation surgery group (OR=2.17, 95% CI=1.77-2.67). The 5-year OS of patients with a good response to chemotherapy (Huvos III+IV) was higher than that of patients with poor response to chemotherapy (Huvos I+II) (OR=2.45, 95% CI=2.10-2.87). Patients without bone metastasis had significantly better 5-year OS than those with bone metastasis at initial diagnosis (OR=0.2, 95% CI=0.11-0.39). CONCLUSIONS: The prognosis of male osteosarcoma patients was slightly worse than that of female patients. Surgery plus standardized chemotherapy can improve the 5-year OS of osteosarcoma patients. Patients who had undergone limb-salvage surgery had a better prognosis. Poor response to chemotherapy and bone metastasis had a negative influence on the prognosis of osteosarcoma.

[The changes in corneal transparency after orthokeratology with juvenile myopia].

Objective: To evaluate the changes of corneal transparency undergoing overnight orthokeratology treatment. Methods: Prospective cohort study. Right eyes of juvenile myopic patients fitted with Ortho-K CL at Qingdao Eye Hospital were enrolled. Corneal optical density values were measured by the Pentacam Scheimpflug system before orthokeratology and at 1 day, 1 week, and 1, 3, 6, and 12 months after wearing. Four concentric radial zones centered on the apex of the cornea (≤2 mm, >2 mm and ≤6 mm, >6 mm and ≤10 mm, and>10 mm and ≤12 mm diameter) were applied. Anterior layer (anterior 120 µm), central layer, and posterior layer (posterior 60 µm) were defined according to corneal depth. The data analysis were used One-Way Repeated Measures ANOVA and LSD test. Results: Forty patients (40 eyes) with myopia (24 male and 16 female, age 10.76±1.74 years) were in enrolled. Corneal optical density value was 13.18±0.23 before orthokeratology, then showed a decreasing trend at the early stage, but there was no statistical difference (within 3months: t=-1.594, -1.472, 0.064, 1.971; P>0.05). The value increased significantly and reached the peak (15.31±0.23, t=7.613, P<0.01) at 6-month, and was still maintained in a high value at 1-year (15.15±0.24, t=7.227, P<0.01). Anterior, central, and posterior layer of corneal optical density values had a downward trend at early stage, and increased significantly in 6-and 12-month (anterior layer t=7.143, 6.177, central layer t=7.508, 6.563, posterior layer t=6.722, 8.533;P<0.01). Only the values decreased significantly in posterior layer at 1-week (baseline 10.21±0.14 vs. 1-week 9.91±0.14, t=-2.348, P=0.024). The corneal optical density value of ≤2 mm diameter began to increase significantly at 1-month (baseline 12.88±0.14 vs. 1-month 13.31±0.19, t=2.158, P=0.037),>2 mm and ≤6 mm diameter at 3-month (baseline 11.71±0.13 vs. 3-month 12.50±0.19, t=3.213, P=0.003), and>6 mm and ≤10 mm diameter at 6-month (baseline 11.40±0.30 vs. 6-month 13.70±0.33, t=7.635, P=0.000). The high values lasted for 1 year at this three areas. However, >10 mm and ≤12 mm diameter had no obvious change in optical density (F=1.668, P>0.05). In addition, the significant reduction of optical density values at early stage were mainly concentrated in the posterior layer of the cornea and the>6 mm and ≤10 mm diameter. Conclusions: Orthokeratology transiently increases corneal transparency of the posterior layer and the>6 mm and ≤10 mm diameter at early stage. However, long-term wearing can cause a decrease of transparency within a 10 mm diameter range. The corneal transparency changes first at the center of the optical zone, then gradually expanding to the periphery, and the anterior, central and posterior layers of cornea are all affected. We speculate orthokeratology affect the corneal oxygen supply and compress cornea mechanically, that leads to corneal stromal remodeling. (Chin J Ophthalmol, 2019, 55:435-441).

MICA, HLA-B haplotypic variation in five population groups of sub-Saharan African ancestry.

The human major histocompatibility complex (MHC) class I chain-related gene A (MICA), located 46 kb centromeric to HLA-B, encodes a stress-inducible protein, which is a ligand for the NKG2D receptor. In addition to its primary role in immune surveillance, data suggest that MICA is involved in the immune response to transplants and in susceptibility to some diseases. In this study, 152 subjects from the Yoruba (n=74), Efik (n=32), and Igbo (n=46) tribes of southern Nigeria, 39 nationwide African-American stem cell donors, and 60 African-American individuals residing in the metropolitan Boston area were studied for MICA, HLA-B allelic variation, haplotypic diversity, and linkage disequilibrium (LD). MICA and HLA-B exhibited a high degree of genetic diversity among the populations studied. In particular, MICA allele and HLA-B-MICA haplotype frequencies and LD in the Efik and Igbo tribes were significantly different from the other study groups. HLA-B and MICA loci demonstrated significant global LD in all five populations (P-values &<0.00001). LD also varied in a haplotype-specific manner. A novel MICA allele was detected in the Boston population. These findings are important from an anthropologic perspective, and will inform future HLA-linked disease association studies in related ethnic groups of African-derived ancestry.

MICA genetic polymorphism and linkage disequilibrium with HLA-B in 29 African-American families.

The human major histocompatibility complex (MHC) class I chain-related gene A ( MICA) is located 46 kb upstream of HLA-B and encodes a stress-inducible protein which displays a restricted pattern of tissue expression. MICA molecules interact with NKG2D, augmenting the activation of natural killer cells, CD8(+) alpha beta T cells, and gamma delta T cells. MICA allelic variation is thought to be associated with disease susceptibility and immune response to transplants. We investigated MICA allelic variations and linkage disequilibrium with HLA-A, B, and DRB1 loci on 110 parental haplotypes from 29 African-American families. PCR/sequence-specific oligonucleotide probing (SSOP) was used to define MICA polymorphisms in exons 2, 3, and 4. Ambiguous allelic combinations were resolved by sequencing exons 2, 3, and 4. Exon 5 polymorphisms were analyzed by size sequencing. For HLA-A, B and DRB1 typing, low-resolution PCR/SSOP and allelic PCR/sequence-specific priming techniques were used. Twelve MICA alleles were observed, the most frequent of which were MICA*008, MICA*004, and MICA*002, with gene frequencies of 28.2, 26.4, and 25.5%, respectively. Thirty-eight HLA-B- MICA haplotypic combinations were uncovered, 22 of which have not been reported in the HLA homozygous typing cell lines from the 10th International Histocompatibility Workshop. Significant positive linkage disequilibria were found in 8 HLA-B- MICA haplotypes. Furthermore, haplotypes bearing HLA-B*1503, *1801, *4901, *5201, *5301, and *5703 were found to segregate with at least two different MICA alleles. Our results provide new data about MICA genetic polymorphisms in African-Americans, which will form the basis for future studies of MICA alleles in allogeneic stem cell transplantation outcome.

CD4 TCRBV CDR3 analysis in prevalent SLE cases from two ethnic groups.

We examined CD4+ T cell TCRBV-CDR3 transcripts from 19 lupus patients and 16 controls to test the hypothesis that CD4+ TCRBV-CDR3 expression in SLE differs from normals. Within the disease group we also performed exploratory analyses to determine the association between risk of oligoclonality and HLA-DRB specificities and the duration of the CDR3 patterns. Oligoclonal patterns consistent with CDR3 restriction were three times more likely in SLE than in controls (OR = 3.7). TCRBV1, BV4, BV5.1, BV7, BV9, BV18 and BV22 gene segment CDR3 patterns of oligoclonality were seen exclusively among lupus patients. HLA-DRB3 increased the risk of oligoclonal expression in SLE. In four patients studied over time, the pattern of TCRBV-CDR3 expression was stable in a second sample obtained 6-14 months later. The increased frequency of CD4+ T cell TCRBV-CDR3 oligoclonal expression in SLE when compared to controls and the persistence of these patterns are consistent with an expanded pool of autoreactive CD4 T cells in SLE which recognize peptides derived from autoantigens. The association of HLA-DRB3 genes with increased risk of CDR3 oligoclonality among the SLE subjects is compatible with the hypothesis that molecules encoded by HLA-DRB3 may facilitate autoantigen recognition by CD4 T cells.

Molecular analysis of major histocompatibility complex allelic associations with systemic lupus erythematosus in Taiwan.

OBJECTIVE: To investigate the association of HLA class II alleles/haplotypes, type I C2 deficiency gene, and tumor necrosis factor a gene promoter allele (TNF2) with systemic lupus erythematosus (SLE) in the Chinese population in Taiwan. METHODS: The HLA-DRB1 and DQB1 alleles were studied in 105 SLE patients and 115 controls by the polymerase chain reaction (PCR)/sequence-specific oligonucleotide probe method, the subtyping of DRB1*15/16 and DRB5 by PCR with sequence-specific primers, type I C2 deficiency gene by PCR, and TNF2 by PCR-Nco I restriction fragment length polymorphism. RESULTS: The frequencies of the HLA class II alleles DRB1*02, DRB1*1502, DRB5*0102, DQB1*0501, and DQB1*0602 and DR2-associated haplotypes DRB1* 1501,DRB5*0101,DQB1*0602 and DRB1*1502,DRB5* 0102,DQB1*0501 were higher among SLE patients than among controls; however, only DQB1*0501 was statistically significantly associated with SLE. No specific allele/haplotype was significantly associated with lupus nephritis. No subject had type I C2 deficiency. SLE patients had a marginally higher percentage of TNF2, which was in linkage disequilibrium with DR3. Since DR3 was not associated with SLE in this Taiwanese Chinese population, TNF2 might play a role in the immunopathogenesis of SLE. CONCLUSION: Although no HLA-DRB1 allele was found to be significantly associated with SLE, the associations with DQB1*0501 and TNF2 suggest that DQB1 and tumor necrosis factor a may be important genetic factors in SLE susceptibility in the Chinese population in Taiwan.