Objective To investigate the delay of the denervated skeletal muscle atrophy with the method of restraining the increment of the connective tissues by tetrandrine and hormone. Methods The left hind limbs of 42 male adult SD rats were made into models of the denervated gastrocnemius, and then the rats were randomly divided into 3 groups, with 14 rats in each. In Group A, tetrandrine (8 mg/L）was injected into the denervated gastrocnemius; in Group B, triamcinolone acetonide（1.6 g/L） was injected; in Group C (the control group),normal saline was injected. Enough samples were obtained according to the different observation indexes at 30 days after operation. Electromyography, muscle wet weight measurement, light microscopy,electron microscopy,and microimage analysis were performed. ResultsThe fibrillation potential amplitude was 0.195 8±0.041 9 μV in Group A and 0.185 2±0.050 3 μV in Group B, and there was no significant difference betweenthe two groups (Pgt;0.05). However,in Group C the fibrillation potential amplitude was 0.137 7±0.058 9μV. The fibrillation potential amplitude was significantly greater in Group A than in Group C（Plt;0.05）. The muscle wet weight was 1.740 0±0.415 9 g in Group A and 1.940 1±0.389 4 gin Group B, and there was no significant difference between the two groups(Pgt;0.05).However, in Group C the muscle wet weight was 0.800 0±0.100 0 g. The muscle wet weight was significantly greater in Group A than in Group C（Plt;0.05）.The microscopy showed that more remarkable atrophy occurred in the control group. The muscle fibers were more complete, thicker and larger, with more nuclei and clearer cross-lines. More connective tissue and flat cells could be observed in Groups A and B. The myogenic protein amount was 440.124 2±46.135 6 in Group A and 476.211 4±41.668 8in Group B, and there was no significant difference between the two groups(Pgt;0.05).However, in Group C the amount was 380.040 0±86.315 9.The myogenic protein amount was significantly greater in Group A thanin Group C（Plt;0.05）. The muscle fiber number, diameter, cross section, and connective tissue increment were all significantly greater in Group A than in Group C（Plt;0.05）; however, there wasno significant difference between Groups A and B (Pgt;0.05). The electron microscopy showed that there were more degeneration changes, such as muscle silk disorder, chondriosome disappearance, and hepatin reduction, could be observed inGroup C than in Groups A and B. Conclusion Tetrandrine and hormone can delay the denervated skeletal muscle atrophy by restraining the increment of the connective tissues.
Objective To observe the delaying effect of neural stem cell (NSC) transplantation on denervated muscle atrophy after peri pheral nerve injury, and to investigate its mechanism. Methods NSCs were separated from the spinal cords of green fluorescent protein (GFP) transgenic rats aged 12-14 days mechanically and were cultured and induced to differentiate in vitro. Thirty-two F344 rats, aged 2 months and weighed (180 ± 20) g, were randomized into two groups (n=16 per group). The animal models of denervated musculus triceps surae were establ ished by transecting right tibial nerve and commom peroneal nerve 1.5 cm above the knee joints. In the experimental and the control group, 5 μL of GFP-NSCsuspension and 5 μL of culture supernatant were injected into the distal stump of the tibial nerve, respectivel. The generalcondition of rats after operation was observed. At 4 and 12 weeks postoperatively, the wet weight of right musculus tricepssurae was measured, the HE staining, the Mallory trichrome staining and the postsynaptic membrane staining were adopted for the histological observation. Meanwhile, the section area of gastrocnemius fiber and the area of postsynaptic membrane were detected by image analysis software and statistical analysis. Results The wounds in both groups of animals healed by first intension, no ulcer occurred in the right hind l imbs. At 4 and 12 weeks postoperatively, the wet weight of right musculus triceps surae was (0.849 ± 0.064) g and (0.596 ± 0.047) g in the experimental group, respectively, and was (0.651 ± 0.040) g and (0.298 ± 0.016) g in the control group, respectively, showing a significant difference (P lt; 0.05). The fiber section area of the gastrocnemius was 72.55% ± 8.12% and 58.96% ± 6.07% in the experimental group, respectively, and was 50.23% ± 4.76% and 33.63% ± 4.41% in the control group, respectively. There were significant differences between them (P lt; 0.05). Mallory trichrome staining of muscle notified that there was more collagen fiber hyperplasia of denervated gastrocnemius in the control group than that in the experimental group at 4 and 12 weeks postoperatively. After 12 weeks of operation, the area of postsynaptic membrane in the experimental group was (137.29 ± 29.14) μm2, which doubled that in the control group as (61.03 ± 11.38) μm2 and was closer to that in normal postsynaptic membrane as (198.63 ± 23.11) μm2, showing significant differences (P lt; 0.05). Conclusion The transplantation in vivo of allogenic embryonic spinal cord NSCs is capable of delaying denervated muscle atrophy and maintaining the normal appearance of postsynaptic membrane, providing a new approach to prevent and treat the denervated muscle atrophy cl inically.
This study analyzed the inherent relation between arterial blood mass flow and muscle atrophy of residual limb to provide some necessary information and theoretical support for the clinical rehabilitation of lower limb amputees. Three-dimensional arterial model reconstruction was performed on both intact side and residual limb of a unilateral transfemoral amputee who is the subject. Then hemodynamic calculation was carried out to comparatively analyze the mass flow state at each arterial outlet of both lower extremities. The muscle atrophy ratio of residual limb was calculated by measuring the cross-sectional area of bilateral muscles. Based on the blood supply relationship, the correlation between arterial blood flow reduction ratio and muscle atrophy ratio was discussed. The results showed that the mass flow of superficial femoral arteries and lateral circumflex femoral arteries severely reduced. Meanwhile rectus femoris, vastus lateralis and vastus medialis which were fed by these arteries showed great atrophy too. On the contrary, the mass flow of deep femoral arteries and medial femoral circumflex arteries slightly reduced. Meanwhile gracilis, adductor longus, long head of biceps which were fed by these arteries showed mild atrophy too. These results indicated that there might be a positive and promotion correlation between the muscle atrophy ratio and the blood mass flow reduction ratio of residual limb during rehabilitation.
Leber hereditary optic neuropathy is an optic neuropathy associated with mitochondrial DNA. The disease affects young men mainly, which is considered to be due to denaturation of the retinal nerve ganglion cell and axonal loss of optic nerve, leading to optic atrophy. Nowadays, there are some development in studying Leber hereditary optic neuropathy by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). It is great help to know the disease, forecast the progression of disease, and take action on intervention. In addition, there is a lack of in-depth study on OCT and OCTA characteristics among different mutation sites of LHON, different genders of the same site, different families of the same site or even different branches of the same family. It is expected to be improved in the future work.
Mutations in optic atrophy (OPA) genes can lead to a similar phenotype, namely optic atrophy, which can manifest as isolated optic atrophy or be accompanied by other systemic symptoms, mostly related to the nervous system. Currently, a total of 13 OPA genes have been discovered, covering a variety of inheritance patterns, including chromosomal dominant inheritance, autosomal recessive inheritance, and X-linked inheritance. Through genetic testing and analysis of patients, it is possible to accurately determine whether they carry mutation genes related to optic atrophy, and predict the progression of the disease and potential complications accordingly. This not only provides valuable genetic counseling and fertility planning guidance for patients and their families, but also helps better understand the disease, discover new therapeutic targets, and lay the foundation for developing more precise and effective drugs or gene therapies in the future.
ObjectiveTo observe the peripapillary atrophy (PPA) and peripapillary choroidal vascularity index (CVI) in patients with different degrees of myopia and to analyze their correlations. MethodsA cross-sectional clinical study. From September 2021 to December 2021, 281 mypoic patients of 281 eyes treated in Eye Hospital of Wenzhou Medical University at Hangzhou were included in this study, and the right eye was used as the treated eye. There were 135 eyes in 135 males and 146 eyes in 146 females. The age was 28.18±5.78 years. The spherical equivalent refraction (SE) was －5.13±2.33 D. The patients were divided into three groups: low myopia group (group A, －3.00 D ＜SE≤－0.50 D), moderate myopia group (group B, －6.00 D≤SE≤－3.00 D);high myopia group (group C, SE＜－6.00 D). The spherical equivalent refraction was statistically different among the three groups (H=241.353, P＜0.05). All of the affected eyes were examined by swept-source optical coherence tomography. Combined with B-scan image,assessment and area measurement of β area, γ area (β-PPA and γ-PPA) were carried out on the en-face image. After binarization of the collected images, the nasal, superior, temporal and inferior CVI of the optic disc were calculated. For comparison between groups, one-way ANOVA was used for continuous variables with normal distribution, Kruskal-Wallis test was used for continuous variables with abnormal distribution, and categorical variables were used χ2 inspection. Linear regression analysis was used for the relationship between β-PPA and γ-PPA area and peripapillary CVI of different regions. Linear regression analysis was used to evaluate the relationships between the area of peripapillary atrophy and peripapillary choroidal vascularity index in different regions. ResultsThere was no statistical difference in the incidence of β-PPA among the three groups (χ2=4.672, P=0.097). The incidence of γ-PPA in group A was lower than that in group B anc C, and the difference was statistically different (χ2=33.053, P＜0.001), in which both group A was lower than group B and C. Among the three groups, the area of β-PPA and γ-PPA was statistically significant (H=36.535, 39.503; P＜0.001, 0.001); the β-PPA area of group A and B was lower than that of group C; the γ-PPA area was group A＜group B＜group C. Peripapillary CVI of different regions in group A, group B and group C was statistically significant (F=11.450, 5.037, 6.018, 4.489; P＜0.05). The temporal CVI in group C was lower than that in group A and B; The inferior CVI of group C was lower than that of group A, and the superior and nasal CVI of group B and C were lower than that of group A. In multivariate analysis, SE (β=0.374, P＜0.001), temporal CVI (β=－0.299, P＜0.001) were correlated with the area of β-PPA (adjusted R2=296, P＜0.001); AL (β=0.452, P＜0.001), temporal CVI (β=－0.220, P＜0.001) were correlated with the area of γ-PPA (adjusted R2=0.309, P＜0.001). ConclusionsThe incidence and area of γ-PPA are increased in the higher degree of myopia group. The area of γ-PPA is positively correlated with the axial length, and both the area of β-PPA and γ-PPA are negatively correlated with temporal CVI.
Objective To study the quantitative changes of ubiquitin l igase MAFbx mRNA and protein expression, muscle atrophy and muscle function following free muscle transplantation and to explore relationshi ps among them. Methods Thirty-six female SD rats, SPF grade, weighing (250 ± 25) g, were used. One hind l imb of the rat was randomly selected as experimental side to receive in situ free gracil is muscle transplantation, and the counterlateral hind l imb underwent no operation serving as control side. General condition of the rats was observed after operation. Muscle contractivecapacity and muscle wet weight maintenance rate of the experimental and the control side were detected 1, 2, 4, 10, 15, and 30 weeks after operation, and 6 rats were killed at each time point. Meanwhile, HE staining was performed to observe muscle fibre cross-sectional area, real-time quantitative PCR was appl ied to detect relative expression of MAFbx/Atrogin-1 mRNA, and Western blot test was used to observe MAFbx protein expression. Results All rats survived till the end of the experiment, all incisions healed well, and no dysfunction occurred in the experimental sides. The value of muscle contractive capacity, muscle wet weight maintenance rate, muscle’s maximal force of single contraction, and muscle’s maximal force of tetanic contraction in the experimental sides dramatically decreased in the first 4 weeks after operation and increased gradually over 4 to 30 weeks. The MAFbx mRNA expression of the experimental sides peaked and was seven times greater than the control sides 2 weeks after operation, then the value gradually decreased over 15 to 30 weeks after operation and was 1.1 to 1.5 times greater than the control sides, and significant difference was evident between the experimental sides and the control sides at each time point (P lt; 0.05). Significant difference was evident between the experimental sides and the control sides in terms of MAFbx protein expression of the muscle 1 to 15 weeks after operation according to the Western blot result (P lt; 0.05), and no significant difference was noted at 30 weeks (P gt; 0.05). The correlation coefficient between muscle wet weight maintenance rate and muscle’s maximal force of single contraction maintenance rate was 0.95, between muscle wet weight maintenance rate and muscle’s maximal force of tetanic contraction maintenance rate was 0.75, between muscle fibre cross-sectional area recovery rate and muscle’s maximal force of single contraction maintenance rate was 0.93, and between muscle fibre cross-sectional area recovery rate and muscle’s maximal force of tetanic contraction maintenance rate was 0.68 (P lt; 0.05). The correlation coefficient between MAFbx mRNA expression and the parameter of muscle wet weight maintenance rate, muscle fibre cross-sectional area recovery rate, muscle’s maximal force of single contraction maintenance rate, and muscle’s maximal force of tetanic contraction maintenance rate was — 0.62 (P lt; 0.05), — 0.45 (P gt; 0.05), — 0.72 (P lt; 0.05) and — 0.78 (P lt; 0.05), respectively; the correlation coefficient between MAFbx protein relative expression and the parameter of muscle wet weight maintenance rate, muscle fibre cross-sectional area recovery rate, muscle’s maximal force of single contraction maintenance rate, and muscle’s maximal force of tetanic contraction maintenance rate was — 0.95 (P lt; 0.05), — 0.82 (P lt; 0.05), — 0.89 (P lt; 0.05), and — 0.54 (P gt; 0.05), respectively. Conclusion Decrease of muscle function after transplantation correlates closely with muscle atrophy. The high expression of MAFbx mRNA and protein, especially their persistent increases from 4 to 15 weeks after nerve reinnervation, is a junction between the muscle atrophy and thedecrease of muscle function.
ObjectiveTo investigate the relationship between genotype and phenotype in children with CRB1 mutated Leber congenital amaurosis (LCA) and early onset retinal dystrophy (EOSRD).MethodsA retrospective clinical study. From January 2013 to December 2019, 10 children with CRB1 mutated LCA/EOSRD were enrolled in the study. The patients were identified as CRB1 mutation by the second generation targeted capture sequencing, Sanger sequencing and the family segregation analysis. All children underwent electroretinogram (ERG) and fundus examination. At the same time, 6 cases were examined by optical coherence tomography (OCT); 1 case was examined by fluorescein fundus angiography (FFA), 7 cases were examined by wide-angle laser scanning ophthalmoscope (UWF SLO).ResultsThere were 6 cases of LCA and 4 cases of EOSRD in 10 patients with CRB1 gene mutations. The average age of first visit was 3.61 years old. The light and dark wave of ERG was flat in 6 cases, and decreased in 4 cases. A total of 19 pathogenic mutations were detected. There were 1 homozygous mutation and 9 compound heterozygous mutations. There were 4, 2 and 1 cases of “copper-coin” like, “salt and pepper” like and “osteocyte” like pigment changes in retina, 1 case of “crystalline pigment” change and 2 cases of macular pigment scar. In 7 cases of UWF SLO examination, different degrees of para-arteriolar pigment epithelium retention (PPRPE) were found in the middle and peripheral fundus. In 6 cases examined by OCT, the outer layer of retina atrophied and the band of ellipsoid disappeared. Symmetrical cystoid macular edema, splitting cystoid macular degeneration and adhesion of epi-macular membrane to optic disc and macular area were found in 1 case, respectively, the retinal structure was rough and thickened, and the fovea became thinner in 3 cases. In FFA examination, 1 case showed uveitis-like changes with late optic disc fluorescein staining, macular fluorescence accumulation, strong fluorescence diffusing along the blood vessels in each quadrant, peripheral PPRPE of “frost-branch” like strong fluorescence.ConclusionThe relationship between genotype and phenotype of CRB1 mutation is complex, and PPRPE is a common characteristic change.
Muscle atrophy of the residual limb after lower-limb amputation is a disadvantage of amputees' rehabilitation. To investigate the biomechanics mechanism of muscle atrophy of the residual limb, we built a finite element model of a residual limb including muscle, skeletons and main vessels based on magnetic resonance images of a trans-femoral amputee, and studied the biomechanics effects of the socket of the lower-limb prosthesis on the soft tissue and vessels in the residual limb. It was found that the descending branch of the lateral femoral circumflex artery suffered the most serious constriction due to the extrusion, while that of the deep femoral artery was comparatively light. Besides, the degree of the constriction of the descending branch of the lateral femoral circumflex vein, femoral vein and deep femoral vein decreased in turn, and that of the great saphenous vein was serious. The stress-strain in the anterior femoral muscle group were highest, while the stress concentration of the inferior muscle group was observed at the end of the thighbone, and other biomechanical indicators at the inferior region were also high. This study validated that the extrusion of the socket on the vessels could cause muscle atrophy to some degree, and provided theoretical references for learning the mechanism of muscle atrophy in residual limb and its effective preventive measures.
Objective To review the research progress of mitochondrial dynamics mediated by optic atrophy 1 (OPA1) in skeletal system diseases. MethodsThe literatures about OPA1-mediated mitochondrial dynamics in recent years were reviewed, and the bioactive ingredients and drugs for the treatment of skeletal system diseases were summarized, which provided a new idea for the treatment of osteoarthritis. Results OPA1 is a key factor involved in mitochondrial dynamics and energetics and in maintaining the stability of the mitochondrial genome. Accumulating evidence indicates that OPA1-mediated mitochondrial dynamics plays an important role in the regulation of skeletal system diseases such as osteoarthritis, osteoporosis, and osteosarcoma. Conclusion OPA1-mediated mitochondrial dynamics provides an important theoretical basis for the prevention and treatment of skeletal system diseases.
