[Minimally invasive vitrectomy for the treatment of severe proliferative diabetic retinopathy].

Objective: To report the efficacy and safety of minimally invasive vitrectomy for the treatment of severe proliferative diabetic retinopathy (PDR) and the effect of preoperative retinal photocoagulation on prognosis. Methods: Case-series study and cohort study. This study included 48 severe PDR patients (53 eyes). There are 28 males and 20 females. The average age was 53.5 (range, 40.0 to 59.0) years old. Patients were divided into two groups according to whether preoperative retinal photocoagulation was performed. Under the guidance of the concept of minimally invasive vitrectomy, all patients received intravitreal injection of conbercept 3 days before standard pars plana vitrectomy with a 27G+ vitrectomy system. To relieve traction, the proliferative fibrovascular membrane was divided into islands as small as possible. It was not necessary to pursue a complete removal of the proliferative membrane. The 27G+ vitrector was flexibly applied as a multifunctional tool for membrane removal by reducing frequencies at which the device entered and left the eye. Intraocular retinal photocoagulation was performed in the main area. The primary outcome measures were best corrected visual acuity (BCVA) and retinal reattachment rate, and the secondary outcome measures were intraoperative and postoperative complications. Statistical analysis was performed using t test, rank sum test and χ² test. Results: All patients tolerated intravitreal conbercept, with no serious intraoperative or postoperative adverse events. Postoperative BCVA values were improved significantly compared with preoperative values (χ²=125.11, P<0.01). The mean logMAR BCVA improved from 1.90 (1.30, 2.30) preoperatively to 1.00 (0.70, 1.90) at 1 week postoperatively, 0.8 (0.5, 1.3) at 1 month postoperatively, 0.7 (0.40, 1.20) at 3 months postoperatively, and 0.70 (0.40, 1.20) at 6 months postoperatively. The visual function increased progressively with time. Postoperatively, the primary and final reattachment rates were 92.5% (50/53) and 96.2% (51/53), respectively. Abnormal intraocular pressure lasted for more than one week occurred in 2 eyes; Vitreous hemorrhage recurred in 5 eyes; Retinal detachment occurred in 4 eyes (7.5%); No postoperative endophthalmitis, choroidal detachment or incision related retinal hole occurred. The intraoperative and postoperative parameters in the preoperative retinal photocoagulation group were better than the preoperative non-photocoagulation group, but the difference was not significant (P>0.05). Conclusions: Minimally invasive vitrectomy is fully qualified for the management of severe PDR, with maximized benefits. (Chin J Ophthalmol, 2021, 57:440-446).

[Comparison of whole blood indium and the serum indium of the population exposed to the indium].

Objective: The method was established for the detection of whole blood indium and serum indium. By comparing the results of two samples, it is possible to explore the significance of whole blood indium and serum indium in the population exposed to indium compounds. Methods: According to GBZ/T 295-2017 and GBZ 294-2017, the whole blood and serum samples were diluted 20 times by 0.5% nitric acid solution (including 0.05% Triton X-100) . Under the standard mode of inductively coupled plasma mass spectrometry (ICP-MS) , whole blood indium and serum indium of indirect exposure group, low exposure group and high exposure group in an indium mine were detected with 20 µg/L rhodium standard solution as internal standard. Results: This method has a working range of 0.00~5.00 µg/L and a correlation coefficien t>0.999. The detection limit and quantitative lower limit of whole blood indium were 0.076 µg/L and 0.26 µg/L respectively. Those of serum indium were 0.06 µg/L and 0.20 µg/L accordingly. The recovery rates of serum and whole blood samples were 88.5%~95.6% and 93.0%~101%. Intra batch precisions were 1.3%~4.4% and 1.9%~3.5% and inter batch precision were 2.4%~6.1% and 2.1%~4.6% in two samples. There were no significant differences between whole blood indium and serum indium in indirect exposure group. The serum indium level was lower than the detection limit in 3 cases, while their whole blood indium was only below the quantitative lower limit. However, in other groups whole blood indium level was significantly higher than serum indium level (P<0.05) and even was two-fold in the high exposure group. Conclusion: The detection of whole blood indium is more sensitive than that of serum indium, which can reflect the internal exposure level more accurately in exposure population. Therefore, the whole blood indium is of more important referential value to health examination and poisoning diagnosis in the population exposed to indium and its compounds.

[Accuracy analysis of full-arch implant digital impressions when using a geometric feature].

Objective: To evaluate the effect of adding a geometric feature on the accuracy of digital impressions obtained by intraoral scanners for implant restoration of edentulous jaw quantitatively. Methods: A dentiform model of the maxilla of completely edentulous arch with 6 implant analogs+scan bodies (No. 1-6) was selected as the reference model. Without geometric feature, the dentiform model was scanned by dental model scanner and repeated for 5 times as true value group. Before and after adding the geometric feature, the same operator used intraoral scanner A (Trios 3) and B (Aoralscan 2) to scan the dentiform model with the same scanning path. Each type of intraoral scanner scanned 10 times and ".stl " datas were obtained. The results were imported into reverse engineering software (Geomagic Studio 2015). The linear distances of center point of upper plane between sacn body 1 to 6 was calculated, denoted as D12, D13, D14, D15 and D16. Trueness was the absolute value subtracted from the measured value of the intraoral scanner groups and true value; precision was the absolute value of pairwise subtraction of the measured values in the intraoral scanner groups.The smaller the value, the better the accuracy or precision.With or without the feature, all scan data were statistically analyzed, and the effect of adding geometric feature on the trueness and precision of the two intraoral scanners were evaluated. Results: As for intraoral scanner A, with the feature in place, significant differences were found in D14, D15, D16 for tureness(t=2.66, 2.75, 2.95, P<0.05); the trueness for D16 decreased from (101.9±47.1) µm to (49.6±30.3) µm. On the other hand, with features on the edentulous area, the precision was significantly increased in D15 and D16 (U=378.00, 672.00, P<0.05); the precision for D15 decreased from 40.8 (45.1) µm to 13.1 (17.0) µm. As for intraoral scanner B, the trueness of D12, D13 and D14 after adding geometric features was significantly better than before (t=3.02, 2.66, U=22.00, P<0.05). With feature on the edentulous area, the trueness for D13 decreased from (116.6±41.2) µm to (70.8±35.5) µm. There was no statistical significance in the trueness of D15 and D16 with or without geometric feature (P>0.05), however, the precision of D15 and D16 after adding geometric feature was significantly better than before (U=702.00, 489.00,P<0.05). The precision of D16 decreased from 112.5 (124.7) µm to 35.9 (85.8) µm. Conclusions: The use of geometric feature in edentulous space improves the trueness and precision of the different principle intraoral scanners tested.

[Application and outlook of robotics in prosthetic dentistry].

At present, robotic system has been applied in many aspects of the field of prosthetic dentistry, such as tooth preparation, oral implant surgery, full denture arrangement, prosthodontic material testing and robotic education of prosthodontics. The advantages of prosthodontic robotics lie in their ability to perform quantitative and precise operations whilerepeating the work flow indefinitely, which assist dentists to complete heavy and complicated daily treatment. In the research and development of prosthodontic robotics, the limitation of oral operation space should be fully considered, and robotics should have high safety and flexibility. The review briefly summarizes the application and existing problems of robotics in prosthodontics, and provides references for further development and design.

[Quantitative study of intraoral scanners' accuracy].

Objective: To establish a standard method to evaluate the scanning accuracy of intraoral scanner (IOS) and to investigate six IOS's scanning accuracy and the relationship between different scan span. Methods: Five simplified six abutments full arch model were fabricated by high accuracy (5 µm) milling machine with 7075 aluminum alloy. The machining accuracy, which was verified by a coordinate measuring machine with higher accuracy (0.7 µm), was considered as the reference accuracy. The model with the highest machining accuracy was considered as the test model in IOS's scanning accuracy test, and computer-aided design (CAD) data of the model was used as the reference data. Six IOS scanned the test model 10 times with the same scanning path, obtained 60 test data. CAD data and test data were input into Geomagic Studio 2014. The preparation part above the margin of the abutments of the data was isolated and divided into 4 segments of interest: single crown, three-unit bridge, five-unit bridge, and full arch. The test data were then best-fit aligned to CAD data or each other followed by deviation analysis. Scanning trueness and precision were then calculated. Results: The mid-value of scanning trueness and precision of six IOS in single crown, three-unit bridge, five-unit bridge and full arch were 13.3-29.6 µm and 7.6-20.7 µm, 15.4-30.9 µm and 8.7-26.5 µm, 17.0-66.1 µm and 11.3-44.2 µm, 24.0-107.9 µm and 24.6-150.1 µm respectively. Conclusions: Long-span scanning can affect the accuracy of IOS to a varying extent.

[Clinical study on anti-senility effect of kuangquan 851 oral liquor type R and type Y].

The anti-senility effects of Kuangquan 851 Oral Liquor type R and type Y were studied and compared with Qing Chun Bao Oral Liquor as control in 303 subjects of geratic period or presenium with senile syndromes of Kidney or Spleen Deficiency. The results indicated that both type R and Y could improve the Kidney and Spleen Deficiency. The effective rates of type R and Y were 96.6% and 92.3% respectively and were much better than that of the control group. The laboratory findings before and after treatment revealed that effects of Kuangquan 851 Oral Liquor were as follows: increasing antioxidation and clearing away free-radicals; promoting collagen metabolism; enhancing the function of T lymphocytes; improving pulmonary, cardiovasular, brain function; raising male serum testosterone and estradiol levels. The two types were similar in effect.

Curcumin inhibits SK-Hep-1 hepatocellular carcinoma cell invasion in vitro and suppresses matrix metalloproteinase-9 secretion.

Curcumin (diferuloylmethane), widely used as a spice and coloring agent in food, possesses potent antioxidant, anti-inflammatory and anticarcinogenic properties. Recently, curcumin was further demonstrated to have an antimetastatic effect in mice. In this study, we attempted to clarify the possible mechanisms of this latter effect of curcumin. A highly invasive SK-Hep-1 cell line of human hepatocellular carcinoma (HCC) was selected for this study. An in vitro assay, without or with Matrigel matrix, was used to quantitate cellular migration and invasion. Gelatin-based zymography was adapted to assay the secretion of matrix metalloproteinase (MMP). We found that curcumin, at 10 microM, inhibited 17.4 and 70.6% of cellular migration and invasion of SK-Hep-1, respectively. Compared with a less invasive human HCC cell line, Huh-7, SK-Hep-1 showed a much higher MMP-9 secretion. Further, and parallel with its anti-invasion activity, curcumin inhibited MMP-9 secretion in SK-Hep-1 in a dose-dependent fashion. We conclude that curcumin has a significant anti-invasion activity in SK-Hep-1 cells, and that this effect is associated with its inhibitory action on MMP-9 secretion.