Diagnostic Performance of Ultrasound Computer-Aided Diagnosis Software Compared with That of Radiologists with Different Levels of Expertise for Thyroid Malignancy: A Multicenter Prospective Study.

The aim of the work described here was to evaluate the diagnostic performance of ultrasound thyroid computer-aided diagnosis (CAD) software. This multicenter prospective study included 494 patients (565 thyroid nodules) who underwent surgery or biopsy after ultrasonography at four hospitals from January 2019 to September 2019. The diagnostic performance metrics of different readers were calculated and compared with the pathologic results. The sensitivity of CAD was outstanding and was equivalent to that of a senior radiologist (90.51% vs. 88.47%, p > 0.05). The area under the curve of CAD was equivalent to that of a junior radiologist (0.748 vs. 0.739, p > 0.05). However, the specificity was only 49.63%, which was lower than those of the three radiologists (75.56%, 85.93% and 90.37% for the junior, intermediate and senior radiologists, respectively). The diagnostic performance of the junior radiologist was significantly improved with the aid of CAD (junior + CAD). The sensitivity and area under the curve of junior + CAD were improved from 72.20% to 89.93% and from 0.739 to 0.816, respectively (both p values <0.05), and the positive predictive value, negative predictive value and κ coefficient improved from 76.3% to 78.6%, 82.0% to 86.8% and 0.394 to 0.511, respectively. Though specificity slightly decreased from 75.56% to 73.33%, the difference was not statistically significant (p > 0.05). In general, the clinical application value of CAD is promising, and its instrumental value for junior radiologists is significant.

Analysis on Chemical Characteristics of Lycii Fructus in Qinghai Province Based on 1H-NMR Plant Metabolomics / 中国实验方剂学杂志

Objective:The chemical differences of Lycii Fructus samples from Qinghai, Ningxia, Gansu, Xinjiang and Inner Mongolia provinces were compared based on proton nuclear magnetic resonance (1H-NMR) plant metabolomics. Method:A total of 97 Lycii Fructus samples from five provinces were collected, including 61 samples in Qinghai, and extracted by 50% methanol for detecting. 1H-NMR spectra were obtained and compared by multivariate statistical analysis for investigating the chemical differences of samples from Qinghai and other production areas. And the content of Lycii Fructus polysaccharides in all samples was determined with the wavelength of 490 nm (calculated by anhydrous glucose). Result:A total of 32 chemical components were detected in the Lycii Fructus extract by 1H-NMR. The multivariate statistical analysis revealed that there was no significant difference among the samples from five provinces. The difference between Lycii Fructus from Qinghai and Ningxia, as well as the samples among the six regions of Qinghai province were relatively small. The similarity values of the majority of samples were >0.85. Univariate analysis showed that no significant difference was observed for the most metabolites in Lycii Fructus collected from five provinces, except for sucrose, glucose, proline and so on. There was no significant difference in the content of Lycii Fructus polysaccharides between Qinghai and other provinces. And the correlation coefficient between the content of Lycii Fructus polysaccharides and the small molecular compounds identified by 1H-NMR was -0.2-0.4. Conclusion:In this study, chemical characteristics of Lycii Fructus in Qinghai province are analyzed from the holistic view by 1H-NMR plant metabolomics, in combination of polysaccharide determination, and the results show that there is no significant difference between samples from Qinghai and other four provinces. The quality evaluation method based on 1H-NMR established in this study can provide scientific basis for improving quality control level and selecting planting areas of Lycii Fructus.

Clinical Phenotype and Gene Mutation Analysis of a Family with Early-Onset Familial Alzheimer′s Disease / 中山大学学报(医学科学版)

@#【Objective】A full exome sequencing of an early-onset family Alzheimer′s disease (EOFAD) was conduct? ed to identify the mutational sites which may cause diseases. The result of the current study may provide suggestion to genetic counseling and prenatal diagnosis.【Methods】Whole exome sequencing was performed on the family members and software PolyPhen-2 as well as SIFT was employed for hazard prediction (Prediction on functional effects of the missense mutation).【Results】The heterozygous mutation c.758A>G (p.Tyr253Cys) in exon 9 of TTC3 gene had been identified in proband whose mother had been proved with heterozygous mutation c.758A>G. According to the family separation and related bioinformatics analysis, the mutant gene was a possible pathogenic mutation. 【Conclusion】 A new mutation was found of c.758A>G in TTC3 gene within a Chinese EOFAD family and a new mutation to the spectrum of genetic mutation in EOFAD was expanded. The finding provides a significant groundwork for future exploration on the mechanisms underlying EOFAD.

[Dynamics of active organic carbon in a paddy soil under different rice farming modes].

A field experiment was conducted to study the dynamics of dissolved organic carbon (DOC), readily oxidizable organic carbon (ROC), and microbial biomass carbon (MBC) in a paddy soil under integrated rice-duck farming (RD), intermittent irrigation (RW), and conventional flooded irrigation (CK), the three rice farming modes typical in southern China. Under these three farming modes, the soil DOC and MBC contents reached the highest during the period from rice booting to heading, while the soil ROC content had less change during the whole rice growth period. Two-factor variance analysis showed that soil MBC was greatly affected by rice growth stage, soil DOC was greatly affected by rice growth stage and farming mode, and soil ROC was mainly affected by farming mode. Comparing with CK, RD significantly increased the soil DOC and ROC contents and their availability, while RW significantly decreased the soil DOC content and its availability but increased the soil ROC content and its availability. No significant differences were observed in the soil MBC and microbial quotient among RD, RW, and CK.

[Individual and interactive effects of aluminum, selenium, silicon and phosphorus on rice seedlings growth].

By using quadratic orthogonal rotation combinatorial design, and taking aluminum (Al), selenium (Se), silicon (Si), and phosphorus (P) as test factors, the regression models of test factors and the survival rate (SR), shoot mass per hundred plants (SMHP), root mass per one hundred plant seedlings (RMHP), and proline contents (PC) of rice seedlings were established, with the individual and interactive effects of the factors analyzed. The individual effects of test factors on the SR, SMHP, RMHP, and PC of rice seedlings decreased in the order of Al > P > Se > Si. Al showed negative effect, while Se, Si, and P showed positive effect. There were no significant interactive effects between the factors, except between Al and Si. Simulated optimization test showed that rice seedlings could grow better in an Al-containing solution when the Al was within the range of 0.587-0.913 mmol L(-1), Se was of 0.478-0.564 mg x L(-1), Si was of 0.613-1.069 mmol x L(-1), and P was of 2.252-2.657 mmol L(-1).

Mesenchymal stem cells transplanted in mdx mice differentiate into myocytes and express dystrophin/utrophin / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the differentiation of rat bone marrow mesenchymal stem cells (MSCs) into myocytes and their expression of dystrophin/utrophin after transplantation in mdx mice.</p><p><b>METHODS</b>BrdU-labeled fifth-passage rat MSCs were transplanted in mdx mice with previous total body gamma irradiation (7 Gy). At 4, 8, 12 and 16 weeks after the transplantation, the mice were sacrificed to detect dystrophin/BrdU and utrophin expressions in the gastrocnemius muscle using immunofluorescence assay, RT-PCR and Western blotting. Five normal C57 BL/6 mice and 5 mdx mice served as the positive and negative controls, respectively.</p><p><b>RESULTS</b>Four weeks after MSC transplantation, less than 1% of the muscle fibers of the mdx mice expressed dystrophin, which increased to 15% at 16 weeks. Donor-derived nuclei were detected in both single and clusters of dystrophin-positive fibers. Some BrdU-positive nuclei were centrally located, and some peripherally within myofibers. Utrophin expression decreased over time after transplantation.</p><p><b>CONCLUSION</b>The myofibers of mdx mice with MSC transplantation express dystrophin, which is derived partially from the transplanted MSCs. Dystrophin expression from the transplanted MSCs partially inhibits the upregulation of utrophin in mdx mouse muscle, showing a complementary relation between them.</p>

Dynamic distribution of implanted human bone marrow mesenchymal stem cells in mdx mice / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the dynamic distribution of human bone marrow mesenchymal stem cells (hBM-MSCs) in mdx mice.</p><p><b>METHODS</b>Twenty-four 8-10-week-old immunocompromised mdx mice were transplanted with 1 x 10(7) passage 5 hBM-MSCs labeled with bromodeoxyuridine (BrdU) by means of injection into the tail vein. The mice were euthanized 48 hours and 2, 4, 8, 12, 16, 20, and 24 weeks after transplantation. BrdU-positive cells in tissue and organs of the mice were detected by immunofluorescence analysis. Skeletal muscle was stained for anti-human nuclei mouse monoclonal antibody (anti-Hu) and analyzed for human dystrophin (Dys) expression by immunohistochemistry and reverse transcription-polymerase chain reaction.</p><p><b>RESULTS</b>After transplantation, BrdU-positive cells were found in most organs (especially in bone marrow, liver, and lung) within 4 weeks, and these cells in liver and lung decreased gradually after 4 weeks. At 48 hours after transplantation, BrdU-positive cells were found in bone marrow, which reached a peak level after 2 weeks and were still detectable after 16 weeks. BrdU-positive cells in skeletal muscle increased gradually over time of transplantation. A small number of anti-Hu positive cells were detected in skeletal muscle 2 weeks after transplantation. A small number of Dys positive cell were seldom found at 4 weeks and small Dys mRNA expression detected 4 weeks after transplantation. The proportion of anti-Hu in parallel with Dys positive cells and Dys mRNA in skeletal muscle of mdx mice increased gradually over time of transplantation.</p><p><b>CONCLUSION</b>After being transplanted into mdx mice, hBM-MSCs are mainly distributed in bone marrow, liver, and lung during the early time (2-4 weeks) , and then in bone marrow and skeletal muscle (after 4 weeks).</p>

Association between angiotensin-converting enzyme and polymorphisms of N5, N10-methylenetetrahydrofolic acid reductase gene in patients with ischemic stroke / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the association between angiotensin-converting enzyme (ACE) and the polymorphisms of N5, N10-methylenetetrahydrofolic acid reductase (MTHFR) gene in patients with ischemic stroke (IS).</p><p><b>METHODS</b>Totally 454 patients with IS (IS group) and 334 controls (control group) were recruited in our study. Their I/D polymorphisms of ACE gene and C677T polymorphisms of MTHFR gene were detected by PCR and denaturing high performance liquid chromatography.</p><p><b>RESULTS</b>The frequencies of DD, ID, II and CC, CT, TT genotype in IS group were 22.5%, 43.4%, 34.1%, and 51.8%, 40.5%, 7.7%, respectively, and were 17.4%, 45.5%, 37.1% and 56.9%, 38.3%, 4.8% in the control group, respectively. DD genotype was associated with large-artery atherosclerosis (LAA), and TT genotype and T allele were associated with LAA and cardioembolism. Synergistic effects were found between TT and DD/ID DD genotypes in the pathogenesis of ischemic stroke.</p><p><b>CONCLUSION</b>DD, TT genotype and T allele are risk factors of IS, and ACE gene and MTHFR gene have synergistic effects in the pathogenesis of IS.</p>

Detecting the polymorphism of methylenetetrahydrofolate reductase gene by denaturing high performance liquid chromatography / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a method for detecting the polymorphism of methylenetetrahydrofolate reductase gene (MTHFR).</p><p><b>METHODS</b>The MTHFR was amplified, and the amplified products were detected by denaturing high performance liquid chromatography (DHPLC), and the amplified MTHFR was confirmed by sequencing and restriction enzyme digesting.</p><p><b>RESULTS</b>A total of 334 individuals of Han people in southern China were recruited in our study, and their polymorphisms of MTHFR were detected. The accurate rate of the DHPLC method, that was very sensitive with 100% detection rate available, was over 99%. The frequencies of CC, CT and TT genotypes were 56.9%, 38.3% and 4.8% individually, and the frequencies of T and C alleles were 23.95% and 76.05% individually.</p><p><b>CONCLUSION</b>The DHPLC method can detect polymorphism of MTHFR rapidly, effectively and economically. And there is the existence of different MTHFR polymorphisms in area and race.</p>