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Background and objective: Ultrasound has been widely used in the diagnosis and minimally invasive treatment of peripheral nerve diseases in the clinic, but there is still a lack of feasibility analysis in rodent models of neurological disease. The purpose of this study was to investigate the changes in the cross-sectional area of the sciatic nerve of different genders and body weights and to explore the effectiveness and reliability of an ultrasound-guided block around the sciatic nerve in living rats. Methods: Using ultrasound imaging anatomy of the sciatic nerve of rats, the cross-sectional area of the sciatic nerve in rats of different genders from 6 to 10 weeks old was calculated, and then analyzed its correlation with body weight. Further analyses were conducted through behavioral and cadaveric studies to evaluate the feasibility of ultrasound-guided perineural injection of the sciatic nerve in rats. Results: We first reported that the sciatic nerve cross-sectional area of rats was increased with age (F = 89.169, P < 0.001), males had a higher sciatic nerve cross-sectional area than females (F = 60.770, P < 0.001), and there was a positive correlation with body weight (rMale = 0.8976, P < 0.001; rFemale = 0.7733, P < 0.001). Behavioral observation of rats showed that the lower extremity complete block rate was 80% following the administration of drugs around the sciatic nerve under ultrasound guidance and staining with methylene blue occurred in all sciatic nerves and surrounding muscles and fascia using 20 ultrasound-guided injections. Conclusions: Ultrasound visualization technology can be used as a new auxiliary evaluation and intervention therapy for animal models of peripheral nerve injury, and will provide overwhelming new references for the basic research of neurological diseases.
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BACKGROUND: Limb body wall complex (LBWC) is a fatal malformation characterized by major defects in the fetal abdominal or thoracic wall, visceral herniation, significant scoliosis or spina bifida, limb deformities, craniofacial deformities, and umbilical cord abnormalities (short or absent umbilical cord). Early diagnosis of this condition is of great clinical significance for clinical intervention and pregnancy decision-making. With the rapid development of fetal ultrasound medicine, early pregnancy (11-13+6 wk) standardized prenatal ultrasound examinations have been widely promoted and applied. AIM: To explore the value of prenatal ultrasound in the diagnosis of fetal LBWC syndrome during early pregnancy. METHODS: The ultrasonographic data and follow-up results of 18 cases of fetal LBWC diagnosed by prenatal ultrasound during early pregnancy (11-13+6 wk) were retrospectively analyzed, and their ultrasonographic characteristics were analyzed. RESULTS: Among the 18 fetuses with limb wall abnormalities, there were spinal dysplasia (18/18, 100%), varying degrees of thoracoschisis and gastroschisis (18/18, 100%), limb dysplasia in 6 cases (6/18, 33%), craniocerebral malformations in 4 cases (4/18, 22%), thickening of the transparent layer of the neck in 5 cases (5/18, 28%), and umbilical cord abnormalities in 18 cases (18/18, 100%), single umbilical artery in 5 cases. CONCLUSION: Prenatal ultrasound in early pregnancy can detect LBWC as early as possible, and correct prenatal evaluation provides important guidance value for pregnancy decision-making and early intervention.
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We examined the vertical distribution characteristics of soil organic carbon (C), total nitrogen (N), total phosphorus (P) and their ecological stoichiometric ratios in 0-80 cm soil profile under three forest stand types in the middle and lower reaches of the Beijiang River, including broad-leaved forest, coniferous forest, and mixed coniferous and broad-leaved forest. The results showed that soil C, N and P contents of the three forest stand types were 12.17-14.25, 1.14-1.31, and 0.27-0.30 g·kg-1, respectively. The contents of C and N decreased with the increases of soil depth. The content of C and N in each soil layer showed that coniferous and broad-leaved mixed forest > coniferous forest > broad-leaved forest. There was no significant difference in P content among the three stand types, and there was no obvious variation in the vertical profile. The soil C/N, C/P, and N/P of the three forest types were 11.2-11.3, 49.0-60.3, and 4.5-5.7, respectively. There was no significant difference in soil C/N among the three stand types. The highest soil C/P and N/P were found in the mixed forest. There was no interaction between soil depth and stand type in affecting soil C, N, P contents and their stoichiometric ratios. There was significant positive correlation between C and N, and between N and C/P in each stand type and soil layer. Soil C/P and N/P had stronger ecological indicating effects on stand types. The coniferous and broad-leaved mixed forest was strongly limited by P availability.