A novel 3D-printed patient-specific instrument based on "H-point" for medial opening wedge high tibial osteotomy: a cadaver study

BACKGROUND

Opening wedge high tibial osteotomy (OWHTO) is an effective surgical treatment for knee osteoarthritis. This study aimed to explore the feasibility and accuracy of a novel 3D-printed patient-specific instrument (PSI) based on "H-point" for medial OWHTO in a prospective cadaver study.

METHODS

Twenty-six fresh-frozen lower limbs were collected and randomly divided into two groups: PSI group treated with 3D virtual preoperative planning and a novel 3D-printed PSI; control group with the standard technique. 3D models were reversely reconstructed for preoperative surgical planning, guide plate design, and simulated osteotomy. Anatomic features of "H-point," surgical time, fluoroscopic dose, correction accuracy including tibiofemoral angle (FTA) and posterior tibial slope (TS) angle were measured.

RESULTS

First, H-point was always described as a bony bulge in the posteromedial to the proximal tibia and had a relatively constant relationship with the osteotomy site. Second, the absolute correction error of mFTA and TS were significantly smaller in the PSI group. The effective rate of TS in the PSI group was more concentrated with absolute correction error within 1° and within 2° for 53.3% and 93.3%, compared to 9.1% and 45.5% in the control group. The total operation time, positioning osteotomy time, distraction correction time and fluoroscopy dose in the PSI group were significantly less than those in the control group.

CONCLUSIONS

The novel 3D-printed PSI based on H-point is feasibility and accuracy with advantages in terms of TS, surgery time and radiation dose for OWHTO.

Astragalus membranaceus root supplementation improves average daily gain, rumen fermentation, serum immunity and antioxidant indices of Tibetan sheep

The use of antibiotics as supplements in animal feed is restricted due to possible health hazards associated with them. Consequently, there is increasing interest in exploiting natural products to improve health and production of livestock with no detrimental side effects. In this study, we examined the effect of Astragalus membranaceus root (AMT) supplementation on DM intake, growth performance, rumen fermentation and immunity of Tibetan sheep. Twenty-four male Tibetan sheep (31 ± 1.4 kg; 9 months old) were assigned randomly to one of four dietary treatments with different levels of AMT: 0, 20, 50 and 80 g/kg DM (A₀, A₂, A₅ and A₈, respectively) in addition to their basal diets. A₀ acted as a control group, and measurements were recorded over a 56-d feeding period. Sheep fed with AMT had a higher average daily gain and a lower feed:gain ratio than controls (P < 0.001). Rumen concentrations of NH₃-N (P < 0.001), total volatile fatty acids (P = 0.028), acetate (P = 0.017) and propionate (P = 0.031) in A₅ and A₈ were higher than those in A₀. The addition of AMT in the feed significantly increased serum antioxidant and immunity factors of the sheep and increased the concentrations of serum interleukin, immunoglobulin and tumour necrosis factor-α (P = 0.010). We concluded that AMT can be used as a feed additive to improve growth performance and rumen fermentation and enhance the immunity of Tibetan sheep. Some responses exhibited a dose-dependent response, whereas other did not exhibit a pattern, with an increase in AMT. The addition of 50 and 80 g/kg AMT of total DM intake showed the most promising results.

Reference gene selection for gene expression studies in lily using quantitative real-time PCR

Quantitative real-time polymerase chain reaction (qRT-PCR) is an important technology used to analyze gene-expression levels. Reference genes, which are assumed to be expressed consistently across various developmental stages and in different tissues, were selected for expression level analysis. Using digital gene expression technology, we selected nine reference genes (18S, EF, CYCOL, SAND, GAPDH, ACTIN, BHLH, TIP, and Clathrin) as candidate reference genes for further study. Using three different analysis methods (GeNorm, NormFinder, and BestKeeper), a total of 144 lily (Lilium x formolongi "Raizan 3") samples were analyzed. The samples were collected from four different tissues under various developmental stages. In addition, leaves treated with different plant hormones were collected and analyzed. The data showed that the stability of the nine reference genes differed among samples, but TIP, EF, Clathrin, and BHLH could be identified as the most stable genes overall. In addition, the relative expression level of LfFT in different lily tissues with the competence to flower was also analyzed to verify the selected reference genes. This study constitutes an important source for selecting reference genes when analyzing the expression patterns of flowering time and floral development regulation genes in lily cultivars.

Effect of melatonin supplementation on cryopreserved sperm quality in mouse

BACKGROUND

Antioxidants protect spermatozoa against cell damage during cryopreservation.

OBJECTIVE

To investigate whether melatonin supplement in the extender may improve the quality of cryopreserved mouse sperm.

METHODS

Kunming mice sperm frozen in extender R18S3 (18% (w/v) raffinose and 3% (w/v) skim milk) supplemented with melatonin were thawed and evaluated.

RESULTS

Mouse spermatozoa were cryopreserved in the freezing extender R18S3 that contained melatonin at 0, 0.125, 0.25 and 0.5 mg/mL melatonin. The extender without melatonin supplement was associated with increased formation of reactive oxygen species (ROS) and decreased sperm motility. Melatonin supplement at 0.125 mg/mL significantly increased the progressive motility of sperm in comparison to other melatonin concentration or control. The percentage of thawed viable sperm with ROS was lower in the melatonin-treated groups than in untreated group. Melatonin supplement also increased antiapoptotic gene Bcl-xl expression in the thawed sperm.

CONCLUSION

Supplement of 0.125 mg/mL melatonin could reduce oxidative damage and apoptosis.