[Effects of Janus kinase/signal transduction and activator of transcription 3 pathway inhibitor in skeletal muscle function in severely burned rats and its mechanism]

Objective: To observe the functional changes of skeletal muscle in severely burned rats, and to investigate the effects and possible mechanisms of Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway inhibitor in skeletal muscle function. Methods: The experiment research method was applied. One hundred and twenty male Wistar rats of 8-week-old were divided into sham injury group, simple burn group, and burn+JAK/STAT3 inhibitor group according to the random number table, with 40 rats in each group. Rats in simple burn group and burn+JAK/STAT3 inhibitor group were inflicted with 50% total body surface area full-thickness scald on the back and abdomen, and rats in sham injury group were sham injured. Rats in burn+JAK/STAT3 inhibitor group were intraperitoneally injected with JAK/STAT3 inhibitor ruxolitinib. On post injury day (PID) 0 (immediately), 1, 4, 7, and 14, 8 rats in each group were used to measure the specific force generated by extensor digitorum longus in optimal length stimulated with pulse frequency of 20, 40, 60, 80, 100, 120, 140, and 160 Hz using a multichannel electrophysiological instrument, and specific force in fatigue period of extensor digitorum longus in optimal length stimulated with pulse frequency of 50 Hz for 0, 10, 20, 30, 60, 120, 180, 240, and 300 s. On PID 0, 1, 4, 7, and 14, carbonyl compound content of extensor digitorum longus was determined by ultraviolet spectrophotometry, and ATP content of extensor digitorum longus was determined by micrometry. Data were statistically analyzed with analysis of variance for repeated measurement, analysis of variance for factorial design, Bonferroni method, and t test. Results: Compared with those of sham injury group, specific forces of extensor digitorum longus of rats in simple burn group were significantly decreased after being stimulated with all the pulse frequency on PID 0, 1, 7, and all the pulse frequency except for 20 Hz on PID 4, and pulse frequency of 20 and 40 Hz on PID 14 (P<0.05 or P<0.01). Compared with those of simple burn group, specific forces of extensor digitorum longus of rats in burn+JAK/STAT3 inhibitor group were significantly increased after being stimulated with all the pulse frequency except for 20 Hz on PID 1 and all the pulse frequency on PID 4, 7, and 14 (P<0.05 or P<0.01). Compared with those of sham injury group, specific forces of extensor digitorum longus of rats in simple burn group were significantly decreased in fatigue period at all the time points post injury and stimulation time points except for 240 s on PID 7 (P<0.05 or P<0.01). Compared with those of simple burn group, specific forces of extensor digitorum longus of rats in burn+JAK/STAT3 inhibitor group were obviously increased in fatigue period at all the stimulation time points except for 60 and 300 s on PID 1 and 240 s on PID 4, and all the stimulation time points on PID 7 and 14 (P<0.05 or P<0.01). The carbonyl compound content of extensor digitorum longus of rats in simple burn group on PID 0, 1, 4, 7, and 14 was (0.651±0.155), (0.739±0.194), (0.618±0.086), (0.813±0.162), (0.615±0.115) nmol/mg, which were obviously higher than (0.196±0.019), (0.156±0.004), (0.169±0.023) (0.156±0.027), (0.175±0.008) nmol/mg in sham injury group (t=7.219, 6.491, 10.938, 9.182, 11.589, P<0.01) and (0.538±0.069), (0.369±0.059), (0.273±0.061), (0.334±0.109), (0.318±0.101) nmol/mg in burn+JAK/STAT3 inhibitor group (t=2.446, 4.689, 8.355, 5.754, 6.097, P<0.05 or P<0.01). The ATP content in extensor digitorum longus of rats in simple burn group on PID 1, 4, 7, and 14 was obviously lower than that in sham injury group (t=7.159, 7.591, 7.473, 4.026, P<0.01) and burn+JAK/STAT3 inhibitor group (t=2.295, 2.575, 2.453, 2.997, P<0.05). Conclusions: After severe burn, the specific force of extensor digitorum longus in rats decreased significantly after being stimulated with different pulse frequencies, and the extensor digitorum longus in rats was prone to fatigue. Blocking the JAK/STAT3 signaling pathway can reduce the oxidative stress of muscle protein and increase ATP content, thereby reducing the muscle strength decline caused by burn injury and improving the muscle strength decline during fatigue period.

Numerical modelling to assess the tear force of human capsulotomy margin

Tear force of the capsulotomy edge is a paramount parameter to affect the surgical safety in cataract surgery. This paper aimed to investigate the stretch force of the capsulotomy edge using finite element (FE) method. A FE model of capsule bag was developed to simulate dynamic response of the lens capsule to the stretch of retractors. The failure criterion based on the distortion energy theory was applied to predict the rupture of the anterior capsule. The simulation results showed a good agreement with the experimental data reported in the literature. Sensitivity studies were then conducted to evaluate the effect of the various parameters on tear force, including the stretching velocity, capsulorhexis dimension, age, retractor width and shape, and rim morphology. The rupture force was proportional to the stretching velocity, capsulorhexis dimension and retractor width, while the age showed the opposite trend. In addition, the retractor shape has a greatly effect on the tear force and the rim of continuous curvilinear capsulorhexis (CCC) has the higher tear resistance. This work can contribute to the understanding of the regularity for capsule rupture.

[Effect of Buyang Huanwu decoction (, BYHWD) on X-ray evaluation of early callus and level of serum alkaline phosphatase in elderly patients with Colles fracture after manual reduction and splint external fixation]

OBJECTIVE

To explore effects of Buyang Huanwu Decoction (, BYHWD) on early callus X-ray evaluation and level of serum alkaline phosphatase in elderly patients with Colles fracture after manual reduction and splint external fixation.

METHODS

From October 2016 to October 2018, 60 elderly patients with Colles fractures were treated with manual reduction and splint external fixation and were divided into experimental group and control group. There were 30 patients in control group, including 15 males and 15 females; aged from 56 to 75 years old with an average of (67.81±5.41) years old; bone mineral density was (0.82±0.24) g/cm 2; patients were performed lift shoulders, bend and extend elbow joint, stretch five fingers and make a fist at 3 days after operation, 3 times daily for 1 month, 30 min once a time. There were 30 patients in experimental group, including 13 males and 17 females; aged from 57 to 77 years old with an average of (66.02±5.16) years old; bone mineral density was (0.76±0.23) g/cm²; patients performed rehabilitation exercise as control group and combined with BYHWD, 400 ml per dose, 2 times daily, 7 days as one course, totally 4 courses. RUSS scores at 14 and 28 days after reduction between two groups were compared, serum level of alkaline phosphatase (ALP) and serum calcium concentration were observed at immediately, 14 and 28 days after reduction.

RESULTS

The patients between two groups were successfully fixed without re fractures and complications occurred. The patients were followed up for 30 to 35 days with an average of (31.60±1.03) days. RUSS score in experimental group at 14 and 28 days after reduction were 4.58±0.31 and 7.07±0.36, respectively; while in control group were 3.98±0.30 and 6.15±0.35, respectively; RUSS score in experimental group was significantly higher than that of control group. Serum alkaline phosphatase concentrations in experimental group at immediately, 14 and 28 days after reduction were (90.62±12.19) mmol/L ,(105.40±11.63) mmol/L, and (160.86±35.77) mmol/L respectively; while in controlgroup were (91.27±13.52) mmol/L ,(94.60±11.10) mmol/L ,(144.17±26.27) mmol/L respectively; there was no statistically difference between two groups at immediately; and had statistically differences between two groups at 14 and 28 days after reduction. There was no significant difference in serum calcium concentration between two groups at immediately, 14 and 28 days after reduction.

CONCLUSION

BYHWD for elderly patients with Colles fracture could promote early formation of callus, effectively increase concentration of serum alkaline phosphatase and promote fracture healing.

Effect of marker segregation distortion on high density linkage map construction and QTL mapping in Soybean (Glycine max L.)

Marker segregation distortion is a natural phenomenon. Severely distorted markers are usually excluded in the construction of linkage maps. We investigated the effect of marker segregation distortion on linkage map construction and quantitative trait locus (QTL) mapping. A total of 519 recombinant inbred lines of soybean from orthogonal and reciprocal crosses between LSZZH and NN493-1 were genotyped by specific length amplified fragment markers and seed linoleic acid content was measured in three environments. As a result, twenty linkage groups were constructed with 11,846 markers, including 1513 (12.77%) significantly distorted markers, on 20 chromosomes, and the map length was 2475.86 cM with an average marker-interval of 0.21 cM. The inclusion of distorted markers in the analysis was shown to not only improve the grouping of the markers from the same chromosomes, and the consistency of linkage maps with genome, but also increase genome coverage by markers. Combining genotypic data from both orthogonal and reciprocal crosses decreased the proportion of distorted markers and then improved the quality of linkage maps. Validation of the linkage maps was confirmed by the high collinearity between positions of markers in the soybean reference genome and in linkage maps and by the high consistency of 24 QTL regions in this study compared with the previously reported QTLs and lipid metabolism related genes. Additionally, linkage maps that include distorted markers could add more information to the outputs from QTL mapping. These results provide important information for linkage mapping, gene cloning and marker-assisted selection in soybean.

Influence of needling conditions on the corneal insertion force

Needle insertion plays an important part in the process of corneal graft surgery. In this paper, a three-dimensional symmetry model of the human cornea is constructed using the finite element method. Simplification of specific optic physiology is defined for the model: The cornea constrained by the sclera is presented as two layers consisting of epithelium and stroma. A failure criterion based on the distortion energy theory has been proposed to predict the insertion process of the needle. The simulation results show a good agreement with the experimental data reported in the literature. The influence of needling conditions (e.g. insertion velocity, rotation parameters and vibration parameters) on the insertion force are then discussed. In addition, a multi-objective optimization based on particle swarm optimization (PSO) is applied to reduce the insertion force. The numerical results provide guidelines for selecting the motion parameters of the needle and a potential basis for further developments in robot-assisted surgery.

[Effects of insulin therapy on skeletal muscle wasting in severely scalded rats and its related mechanism]

Objective: To explore the effects of insulin therapy on skeletal muscle wasting (SMW) in severely scalded rats and its related mechanism. Methods: Totally 48 male Wistar rats aged 7-8 weeks were divided into simple scald (SS) group and insulin therapy (IT) group according to the random number table, with 24 rats in each group. After weighing the body mass and measuring the blood glycemic level of the tail end with a glucometer, the rats in the two groups were immersed in hot water at 94 ℃ for 12 seconds to make a full-thickness dorsal scald model involving 30% total body surface area. Rats in group IT were subcutaneously injected with 1 U/kg insulin glargine at 8: 00 a day from post injury day (PID) 1 to 7, whilst rats in group SS were given the same amount of normal saline. Rats in the two groups were given 10 mL/kg enteral nutritional emulsion by intragastric infusion at 8: 00 (after insulin administration), 13: 00, and 18: 00 a day respectively from PID 1 to 7. The blood glycemic levels of tail end of rats in the two groups were measured by glucometer before insulin administration on PID 1-4, 6, and 7 and on every morning of PID 8, 9, 11, 12, and 14. The body mass of rats in the two groups on PID 14 without any treatment was weighed. Eight rats from each group were collected respectively on PID 4, 7, and 14 to harvest tibialis anterior muscle (TAM) samples. The mass of TAM on PID 14 was weighed. The ultrastructural changes of TAM myocytes on PID 7 were observed with transmission electron microscope. The apoptotic rates of TAM myocytes on PID 4, 7, and 14 were assessed by the assay of terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphate-biotin nick end labeling, the expressions of cysteine-aspartic protease-3 (caspase-3) of TAM on PID 4, 7, and 14 were detected with immunohistochemistry, and protein expressions of endoplasmic reticulum (ER) stress (ERS) associated proteins glucose-regulated protein 78 (GRP78), CCAAT/enhancer binding protein-homologous protein (CHOP), and activated caspase-12 of TAM on PID 4, 7, and 14 were detected with Western blotting. Data were processed with completely random design t test, analysis of variance for repeated measurement, analysis of variance for factorial design, t test, and Bonferroni correction. Results: The blood glycemic level and body mass of rats in the two groups before injury were similar (t=0.204, 0.405, P>0.05). There were no statistically significant differences in blood glycemic levels of rats between the two groups on PID 1, 6, 9, 11, 12, and 14 (t=0.229, 3.339, 1.610, 0.178, 0.181, 0.079, P>0.05). Compared with those of group SS, blood glycemic levels of rats in group IT were significantly lower on PID 2, 3, 4, 7, and 8 (t=7.245, 4.165, 4.609, 4.018, 3.995, P<0.05 or P<0.01). On PID 14, the body mass and TAM mass of rats in group IT were (271±19) g and (0.47±0.05) g respectively, both obviously higher than (254±12) g and (0.43±0.04) g of group SS (t=2.159, 2.375, P<0.05). On PID 7, nuclear pyknosis and deformation, chromosome misdistribution, and ER swelling in TAM myocytes of rats in group SS were observed; the apoptotic alterations and ER swelling of TAM myocytes were alleviated in rats of group IT as compared with those of group SS. The apoptotic rates of TAM myocytes of rats in group IT were obviously lower than those of group SS on PID 4, 7, and 14 (t=4.262, 9.153, 9.799, P<0.01). The expressions of caspase-3 in TAM of rats in group IT were obviously lower than those of group SS on PID 7 and 14 (t=10.429, 7.617, P<0.01). Compared with those of group SS, the protein expressions of GRP78 were obviously increased on PID 4 and 14 (t=4.172, 4.437, P<0.05), the protein expressions of activated caspase-12 were obviously decreased on PID 7 and 14 (t=11.049, 11.181, P<0.01), and the protein expressions of CHOP were obviously decreased on PID 4, 7, and 14 (t=13.837, 9.572, 6.930, P<0.01) in TAM of rats in group IT. Conclusions: Insulin therapy may reduce skeletal muscle myocytes apoptosis and SMW by alleviating ERS in rats with severe scald.

[Effects of leucine on adipogenesis in 3T3-L1 preadipocytes during and after differentiation]

OBJECTIVE

To observe the effects of leucine on adipogenesis in 3T3-L1 preadipocyte during and after differentiation, and to investigate possible mechanisms.

METHODS

Respectively, 0.0 (control), 0.5, 1.0 and 2.0 mmol/L leucine was added in 3T3-L1 cells and cell proliferation was measured by MTT. Then, 3T3-L1 preadipocyte was induced to differentiate. Leucine was added during whole differentiation period, or after differentiation for 4 days. The cells were stained with Oil Red O dye to observe lipid droplet. The culture media were collected and used to determine glycerol contents. Meanwhile, protein expressions related to lypolytic enzymes, leptin signaling pathway were determined by Western blot.

RESULTS

MTT result showed that cell viabilities were (100.00±12.10)%, (102.73±12.38)%, (103.94±14.65)%, (108.70±5.05)% in 0.0, 0.5, 1.0 and 2.0 mmol/L leucine groups, respectively, there were no significant differences in cell proliferation among 4 groups (F=1.07, P=0.383). When 0.0, 0.5, 1.0 and 2.0 mmol/L leucine was added during differentiation, the relative number of lipid droplet was 1.00±0.06, 0.94±0.09, 0.82±0.08 and 0.79±0.04, respectively (F=11.74, P<0.001), and it was significantly lower in 1.0 and 2.0 mmol/L leucine groups than in control group (P=0.002 and P<0.001, respectively). There was no significant difference in lipid droplet when leucine was added after differentiation (F=0.16, P=0.924). When leucine was added during differentiation, the increment of glyceride contents in medium was (65.04 ± 11.75), (71.45 ± 23.71), (79.37 ± 17.63) and (110.32 ± 25.36) μmol/L, respectively (F=2.92, P=0.100). And it was significantly higher in 2.0 mmol/L leucine group (110.32 ± 25.36) μmol/L than in control group (65.04 ± 11.75) μmol/L (t=2.73, P=0.026). No significant difference of the increment of glyceride contents among 4 groups was observed when leucine was added after differentiation (F=0.80, P=0.528). Western blot results showed that leucine treatment during differentiation upregulated expression level of hormone-sensitive lipase phosphorylation (after 0.0 and 2.0 mmol/L leucine treatment,the protein levels were 1.00 ± 0.08 vs. 2.54 ± 0.27, P<0.001) , and downregulated the protein expression levels of perilipin A, leptin and leptin-related pathway, such as leptin receptor, Janus kinase 2 and suppressor of cytokine signaling-3 (after 0.0 and 2.0 mmol/L leucine was added, the protein levels were (1.00 ± 0.03) vs. (0.31 ± 0.07) , (1.00 ± 0.08) vs. (0.22±0.07) , (1.00±0.07) vs. (0.21 ± 0.04) , (1.00 ± 0.03) vs. (0.35 ± 0.05) , (1.00 ± 0.06) vs. (0.34 ± 0.05) , P<0.001). Leucine treatment after differentiation had no effects on these protein expressions (all P>0.05).

CONCLUSION

Leucine inhibits adipogenesis during 3T3-L1 preadipocyte differentiation by the regulation of lypolytic enzymes and leptin signaling pathway; however, leucine has no effect on adipogenesis when differentiation completed.

An efficient hierarchical generalized linear mixed model for mapping QTL of ordinal traits in crop cultivars

Many important phenotypic traits in plants are ordinal. However, relatively little is known about the methodologies for ordinal trait association studies. In this study, we proposed a hierarchical generalized linear mixed model for mapping quantitative trait locus (QTL) of ordinal traits in crop cultivars. In this model, all the main-effect QTL and QTL-by-environment interaction were treated as random, while population mean, environmental effect and population structure were fixed. In the estimation of parameters, the pseudo data normal approximation of likelihood function and empirical Bayes approach were adopted. A series of Monte Carlo simulation experiments were performed to confirm the reliability of new method. The result showed that new method works well with satisfactory statistical power and precision. The new method was also adopted to dissect the genetic basis of soybean alkaline-salt tolerance in 257 soybean cultivars obtained, by stratified random sampling, from 6 geographic ecotypes in China. As a result, 6 main-effect QTL and 3 QTL-by-environment interactions were identified.