Gamma-aminobutyric acid (GABA) improves salinity stress tolerance in soybean seedlings by modulating their mineral nutrition, osmolyte contents, and ascorbate-glutathione cycle.

BACKGROUND: In plants, GABA plays a critical role in regulating salinity stress tolerance. However, the response of soybean seedlings (Glycine max L.) to exogenous gamma-aminobutyric acid (GABA) under saline stress conditions has not been fully elucidated. RESULTS: This study investigated the effects of exogenous GABA (2 mM) on plant biomass and the physiological mechanism through which soybean plants are affected by saline stress conditions (0, 40, and 80 mM of NaCl and Na2SO4 at a 1:1 molar ratio). We noticed that increased salinity stress negatively impacted the growth and metabolism of soybean seedlings, compared to control. The root-stem-leaf biomass (27- and 33%, 20- and 58%, and 25- and 59% under 40- and 80 mM stress, respectively]) and the concentration of chlorophyll a and chlorophyll b significantly decreased. Moreover, the carotenoid content increased significantly (by 35%) following treatment with 40 mM stress. The results exhibited significant increase in the concentration of hydrogen peroxide (H2O2), malondialdehyde (MDA), dehydroascorbic acid (DHA) oxidized glutathione (GSSG), Na+, and Cl- under 40- and 80 mM stress levels, respectively. However, the concentration of mineral nutrients, soluble proteins, and soluble sugars reduced significantly under both salinity stress levels. In contrast, the proline and glycine betaine concentrations increased compared with those in the control group. Moreover, the enzymatic activities of ascorbate peroxidase, monodehydroascorbate reductase, glutathione reductase, and glutathione peroxidase decreased significantly, while those of superoxide dismutase, catalase, peroxidase, and dehydroascorbate reductase increased following saline stress, indicating the overall sensitivity of the ascorbate-glutathione cycle (AsA-GSH). However, exogenous GABA decreased Na+, Cl-, H2O2, and MDA concentration but enhanced photosynthetic pigments, mineral nutrients (K+, K+/Na+ ratio, Zn2+, Fe2+, Mg2+, and Ca2+); osmolytes (proline, glycine betaine, soluble sugar, and soluble protein); enzymatic antioxidant activities; and AsA-GSH pools, thus reducing salinity-associated stress damage and resulting in improved growth and biomass. The positive impact of exogenously applied GABA on soybean plants could be attributed to its ability to improve their physiological stress response mechanisms and reduce harmful substances. CONCLUSION: Applying GABA to soybean plants could be an effective strategy for mitigating salinity stress. In the future, molecular studies may contribute to a better understanding of the mechanisms by which GABA regulates salt tolerance in soybeans.

Test-retest reliability analysis of MRI criteria in the 2019 Bosniak classification of cystic renal masses / 中华放射学杂志

Objective:To evaluate the test-retest reliability of MRI criteria in the 2019 Bosniak classification of cystic renal masses (CRMs) and to analyze the impact of lesions′ property, size and readers′ experience on the test-retest reliability.Methods:From January 2009 to June 2019, 207 patients with 207 CRMs were included in this retrospective study. All of them underwent renal MRI and surgical-pathologic examination. According to Bosniak classification, version 2019, all CRMs were independently classified twice by eight radiologists with different levels of experience. All radiologists were blinded to the pathology of the lesions. By using intraclass correlation coefficient (ICC), test-retest reliability was evaluated for all CRMs and for subgroups with different pathological properties (benign and malignant) and different sizes (≤40 mm and>40 mm). The test-retest reliability of 4 senior readers (≥10 years of experience) and 4 junior readers (<10 years of experience) were evaluated respectively. The comparison of ICC was performed using Z test. Results:The 207 CRMs included 111 benign lesions (83 benign cysts, 28 benign tumors) and 96 malignant tumors. There were 87 lesions with maximum diameter ≤40 mm and 120 with maximum diameter>40 mm. The test-retest reliability (ICC) of each reader for all lesions was 0.776-0.888, the overall ICC was 0.848 (95%CI 0.821-0.872). The ICCs of senior and junior readers were 0.853 (95%CI 0.824-0.880) and 0.843 (95%CI 0.811-0.871) respectively, without significant difference between the two groups ( Z=0.85, P=0.374). The ICC of all readers was 0.827 for benign lesions and 0.654 for malignant lesions, showing significant difference ( Z=2.80, P=0.005). The ICC was 0.770 for lesions ≤40 mm and 0.876 for lesions>40 mm, which was significantly different ( Z=-2.36, P=0.018). For CRM subgroups with different pathological properties and different sizes, there was no significant difference in test-retest reliability between senior and junior readers (all P>0.05). Conclusion:The test-retest reliability of MRI criteria in the 2019 Bosniak classification of CRMs is excellent and unaffected by readers′ experience. The reliabilities are not consistent among CRMs of different pathological properties and different sizes, but all reached the level of good and above.

The research on MRI for differential diagnosis of benign and malignant lesions of SPN / 中国医学装备

Objective:To investigate the clinical value of magnetic resonance imaging (MRI) in differential diagnosis for benign and malignant lesions of solitary pulmonary nodules (SPN).Methods: 120 patients with SPN were enrolled in the retrospective analysis, and all of them underwent scan of MR including MRI, DCE-MR and diffusion weighted imaging (DWI) before their surgery. All of patients received detection of pathology or histopathological examination after their surgery, and the ADC values under different b values of dispersion sensitivity factor (300 s/mm2, 500 s/mm2 and 800 s/mm2) were compared.Results:Under the conditions both of 300 s/mm2 and 800 s/mm2, the differences of ADC value between benign nodule and malignant nodule were not statistically significant (t=1.195,P>0.05). And under the condition of 500 s/mm2, the ADC value of benign nodule was significantly higher than that of malignant nodule (t=4.313,P<0.05), and at this time, the sensitivity, specificity, rate of missed diagnosis and misdiagnosis rate of the differential diagnosis for benign and malignant lesions of SPN by using MR were 85.71％, 74％, 14.9％ and 26％, respectively.Conclusion: MR examination has higher sensitivity in differential diagnosis for benign and malignant lesions of SPN, and it has a certain clinical value when it is used as early detecting method.

Preliminary study on the size-changing lateral cerebral ventricle in second-third trimester normal pregnancy with gestational age / 实用放射学杂志

Objective To explore the growing change of sizes of lateral cerebral ventricle in second-third trimester normal fetuses in MRI,to provide the normal reference for clinical monitoring.Methods MRI findings in 98 normal second-third trimester fetuses were retrospectively analyzed.The fetuses were divided into 6 groups according to gestational age (unit:week)including 18-21,22-25,26-29,30-33,34-37 and 38-40 weeks,respectively.The maximum transverse sizes of fetal atrium and occipital horns of lateral ventricle (cm)were measured.The SigmaStat statistical program was used for statistical analysis.Results The length of lateral ventricle atrium horn in 6 groups were 0.35 ± 0.03,0.33 ± 0.05,0.31 ± 0.04,0.30 ± 0.03,0.26 ± 0.05 and 0.25 ± 0.04,respectively,and the ventricle length of occipital horns were 0.91± 0.09,0.84 ± 0.09,0.84 ± 0.1 1,0.81 ± 0.13,0.80 ± 0.1 1 and 0.74 ± 0.13,respectively.The length of lateral ventricle atrium horn and ventricle occipital horns among some differ-ent groups showed significant differences (P <0.05).The length of fetal ventricle atrium and occipital horn were reduced gradually with gestational ages.Conclusion The ventricular length of atrium and occipital horn in second-third trimester normal fetuses reduce gradually with gestational ages.