[Characteristics and microRNA expression profile of exosomes derived from odontogenic dental pulp stem cells].

OBJECTIVE: To investigate the characteristics of exosomes derived from dental pulp stem cells (DPSCs) in the direction of odontogenic differentiation, to analyze the differences in microRNA expression profile between exosomes derived from undifferentiated and odontogenic DPSCs, and to analyze their possible signal transduction pathways. METHODS: (1) DPSCs were cultured in α minimum Eagle' s medium (α-MEM), and odontogenic DPSCs were cultured in odontogenic differentiation medium for 21 days, using alizarin red staining and alkaline phosphatase staining to identify the odontogenic differentiation. Exosomes from the cell supernatant were isolated respectively, named as dental pulp stem cells-exosomes (DPSCs-Exo) and dental pulp stem cells-odontogenic-exosomes (DPSCs-OD-Exo). The exosomes were identified by transmission electron microscopy, nanoparticle tracking analysis and Western blot. (2) The microRNA expression profiles of DPSCs-Exo and DPSCs-OD-Exo were investigated by microRNA microarray. To validate the result of the microRNA microarray, real-time quantitative polymerase chain reaction (real-time PCR) assay was applied on 3 most significantly differential expressed microRNA. Pathway analysis was taken to detect enriched pathways associated with the predicted target genes of microRNA. RESULTS: (1) The DPSCs were isolated and cultured in vitro showed typical fibroblast-like morphology. The odontogenic differentiated DPSCs were spindle-shaped, polygonal, and uniform in size. Odontogenic differentiation group showed a large number of dark deposits in alizarin red staining and the cells were darkly stained in alkaline phosphatase staining, while the cells in normal culture medium group did not show obvious dyeing. The DPSCs-Exo and DPSCs-OD-Exo had the same morphology, both showed bilayer membrane and cup-shape. The peak sizes of DPSCs-Exo and DPSCs-OD-Exo were (114.67±9.07) nm and (134.00±8.54) nm, respectively. The difference between the two was statistically significant. DPSCs-Exo and DPSCs-OD-Exo both expressed the markers of exosomes, tumor susceptibility gene (TSG)101 and CD63. (2) microRNA microarray results showed that the expression profiles of DPSCs-Exo and DPSCs-OD-Exo were different. Nineteen increased by more than two times, and one decreased by 64%. Real-time PCR results showed that the expression levels of microRNA-1246, microRNA-1246-100-5p and microRNA-1246-494-3p in DPSCs-OD-Exo were significantly up-regulated. The difference was statistically significant. microRNA target prediction database and gene signaling pathway database were used to analyze differentially expressed microRNA, and it was predicted that differentially expressed microRNA could target axis inhibition protein 2(AXIN2) gene and Wnt/ß-catenin signaling pathway. CONCLUSION: DPSCs-OD-Exo and DPSCs-Exo had differences in their microRNA expression profile. Those differentially expressed microRNA may be involved in the regulation of DPSCs odontogenic differentiation.

[Establishment of a nucleic acid dipstick test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay].

OBJECTIVE: To develop a rapid test for detection of Schistosoma japonicum specific gene fragments based on the recombinase-aided isothermal amplification assay (RAA) and nucleic acid dipstick test. METHODS: The S. japonicum SjG28 gene fragment was selected as the target gene fragment, and the primers and fluorescent probe were designed and synthesized. Then, a S. japonicum nucleic acid dipstick test was established. The sensitivity of this dipstick test was evaluated by detecting different copies of recombinant plasmids containing the S. japonicum SjG28 gene fragment and different concentrations of genomic DNA from adult worms of S. japonicum, and the specificity of the dipstick test was evaluated by detecting the genomic DNA from Clonorchis sinensis, S. mansoni, Ancylostoma duodenale, S. haematobium, Babesia and Paragonimus westermani. RESULTS: The S. japonicum nucleic acid dipstick test based on the S. japonicum SjG28 gene fragment showed the minimum detectable limit of 10 copies/µL of the recombinant plasmid containing the S. japonicum SjG28 gene fragment and the minimum detectable limit of 1 pg/µL of S. japonicum genomic DNA, and the dipstick assay tested negative for the genomic DNA from C. sinensis, S. mansoni, A. duodenale, S. haematobium, Babesia and P. westermani. CONCLUSIONS: A rapid, simple, and visualized assay is established for detection of S. japonicum specific gene fragments based on RAA and nucleic acid dipstick test.

[Performance of a recombinase - aided amplification assay for detection of Schistosoma japonicum infections in Oncomelania hupensis].

OBJECTIVE: To evaluate the efficiency of a recombinase-aided amplification (RAA) assay for the detection of Schistosoma japonicum infections in Oncomelania hupensis snails. METHODS: A group test was employed. Fifty Oncomelania snails were collected as a detection sample. The detection samples without infected snails were designated as negative specimens, while the detection samples that contained different numbers of infected snails were designated as positive specimens. A total of 10 negative specimens, 10 positive specimens containing 1 infected snail, 20 positive specimens containing 2 infected snails and 10 positive specimens containing 3 infected snails were assigned. Following random grouping, 40 specimens were subject to the florescent RAA assay using a blind method. The miradium shedding method served as a gold standard, and the sensitivity, specificity, Youden's index and coincidence rate of the florescent RAA assay were estimated. In addition, 20 samples consisted of 5 negative specimens and 15 positive specimens with 1, 2 and 3 infected snails respectively were grouped randomly. The same specimens were detected using the crushing method and fluorescent RAA assay with the blind method in a paired-design manner. Then, the test results were compared and analyzed. RESULTS: Florescent RAA assay detected 29 positives in the 30 specimens containing different numbers of infected snails, with a sensitivity of 96.67%, and 8 negatives in the 10 detection specimens without infected snails, with a specificity of 80.00%, showing a Youden's index of 0.77. The coincidence rate was 100% among 10 repeated assays for a detection specimen. In addition, there was no significant difference in the detection of infected snails between the florescent RAA assay and the crushing method (χ2 = 0, P > 0.05), and the actual coincidence rates of the florescent RAA assay and crushing method were 95.00% (19/20) and 90.00% (18/20) with the real results, respectively. CONCLUSION: Fluorescent RAA assay has a favorable efficiency for the detection of S. japonicum infections in Oncomelania snails, which shows a potential in screening of S. japonicum-infected Oncomelania snails.

[Establishment of the gene detection method of Schistosoma mansoni based on the recombinase-aided isothermal amplification assay].

OBJECTIVE: To establish a recombinase-aided isothermal amplification (RAA) assay for nucleic acid detection of Schistosoma mansoni. METHODS: The 121 bp highly-repeated sequence of S. mansoni was selected as the target gene fragment to be detected. The primers and fluorescent probes were designed using the Amplfix software, and a fluorescent RAA assay was established and optimized. The fluorescent RAA assay was performed to detect gradient diluent recombinant plasmids containing target gene fragment and different concentrations of S. mansoni genomic DNA to determine the sensitivity, and this assay was applied to detect the genomic DNA of S. japonicum, S. haematobium, Ancylostoma duodenale and Clonorchis sinensis to evaluate the specificity. RESULTS: A fluorescent RAA assay was successfully established, which was effective to amplify the specific gene fragments of S. mansoni within 20 min at 39 ℃. The minimum detectable limit of the fluorescent RAA assay was 10 copies/µL using recombinant plasmids as templates and 0.1 fg/µL using S. mansoni genomic DNA samples as templates. The fluorescent RAA assays were all negative for detecting the genomic DNA from S. japonicum, S. haematobium, A. duodenale and C. sinensis. CONCLUSIONS: A novel fluorescent RAA assay is successfully established, which is simple, rapid, sensitive and specific to detect genomic DNA of S. mansoni.

LINC00662 promotes cell proliferation, migration and invasion of melanoma by sponging miR-890 to upregulate ELK3.

OBJECTIVE: Melanoma is one of the most malignant types of skin tumors and accounts for the majority of skin cancer-related deaths. LINC00662 is a tumor promoter in multiple types of cancer, but the role of LINC00662 in melanoma has not been fully elucidated. MATERIALS AND METHODS: The expression levels of LINC00662, miR-890, and ELK3 were detected by Real Time-quantitative Polymerase Chain Reaction (RT-qPCR). MTT assay was performed to measure the cell proliferation ability in A375 and SK-MEL-1 cells. Cell migration and invasion abilities were measured by wound healing assay and transwell assay, respectively. Besides, Luciferase reporter assay was employed to examine the interaction between miR-890 and LINC00662 or ELK3. RESULTS: In the present study, it was demonstrated that melanoma patients with high expression levels of LINC00662 had a shorter survival time than those with low expression levels of LINC00662. LINC00662 exhibited higher expression levels in melanoma tissues and cell lines. Additionally, suppression of LINC00662 impaired cell proliferation, migration, and invasion. Furthermore, animal experiments demonstrated that LINC00662 facilitated tumor growth in vivo. LINC00662 was confirmed to bind with miR-890, and ELK3 was identified as a downstream target gene of miR-890. Furthermore, miR-890 was found to negatively regulate ELK3 expression. Through rescue assays, overexpression of ELK3 reversed the inhibitive effects of LINC00662 knockdown or miR-890 mimics on the cell proliferative, migratory, and invasive abilities. CONCLUSIONS: Our results demonstrated that LINC00662 facilitated the occurrence and development of melanoma by sponging miR-890 to upregulate ELK3. This discovery implied that LINC00662 may be a promising prognostic and therapeutic biomarker for patients with melanoma.

[Target delivery of small interfering RNAs with vitamin E- loaded lipid nanoparticles in inhibition of hepatitis C virus core protein expression in mouse model].

Objective: To study the efficacy of vitamin E-loaded lipid nanoparticles (VE-DC) in the mouse model to target small interfering RNA (siRNA) for inhibition of hepatitis C virus(HCV) core protein expression. Methods: A high-pressure hydrodynamic method was adopted to construct an animal model of liver-specific expression to inject the plasmid containing HCV core protein into mice tail vein. Western blotting and immunofluorescence techniques were used to evaluote the liver targeting property of VE - DC/siRNA nanoparticles and the effectiveness to repress HCV Core expression. Dual luciferase reporter gene assays and in vivo imaging in mice further confirmed the inhibiting effect of VE-DC/siRNA on gene expression mediated by HCV 5' untranslated region. The adverse reactions of VE-DC/siRNA were reported by detecting serum creatinine, white blood cells and interferon. Student's t - test and one -way analysis of variance were used to compare the difference between the two groups, and P < 0.05 was considered statically significant. Results: The dual luciferase reporter gene analysis showed that the luciferase activity of the VE-DC/siRNA treated group was 39.67 ± 15.53, which was significantly lower than 77.33±11.06 of the DC/siRNA group and 91.67 ± 13.65 of the siRNA treated group, P < 0.05. The difference was statistically significant, and there was no obvious organ toxicity and obvious immune response to VE-DC/siRNA. Nanoparticle VE-DC has a good liver targeting ability, which can transport siRNA to the liver and effectively inhibit the expression of HCV Core, with an average inhibition rate of 83.01%. Conclusion: VE-DC could target the delivery of siRNA to the liver and inhibit the expression of HCV- related genes in a mouse model, showing high effectiveness and low toxicity.

LncRNA SNHG16 predicts poor prognosis in ESCC and promotes cell proliferation and invasion by regulating Wnt/ß-catenin signaling pathway.

OBJECTIVE: Increasing evidence indicated that small nucleolar RNA host gene 16 (SNHG16) acted as a key regulator in the proliferation and metastasis of several cancers, including esophageal squamous cell carcinoma (ESCC). In this research, we aimed to explore biological functions, clinical significance and the underlying molecular mechanisms of SNHG16 in ESCC. PATIENTS AND METHODS: qRT-PCR was performed to examine the expression of SNHG16 in ESCC cell lines and clinical ESCC tissue samples. The association of SNHG16 expression with clinicopathological factors and prognosis was statistically analyzed. Cell Counting Kit-8, flow cytometry, and transwell invasion assays were performed to determine the effect of SNHG16 in the regulation of biological behaviors of ESCC cells. Luciferase assay and Western blot were performed to determine the activation of Wnt/ß-catenin signaling pathway RESULTS: We observed that SNHG16 expression levels were significantly upregulated in ESCC tissues and cell lines compared with the corresponding normal tissues and normal esophageal cell line, respectively. In addition, increased expression of SNHG16 were strongly linked to tumor stage (p = 0.019), lymph nodes metastasis (p = 0.007) and clinical stage (p = 0.026). Kaplan-Meier assay showed that the survival time of patients with high SNHG16 expression was significantly shorter than those with low SNHG16 expression (p = 0.0017). Univariate and multivariate analyses showed that high SNHG16 expression in ESCC was an independent predictor of poor survival. Loss-of-function experiments revealed that knockdown of SNHG16 suppressed proliferation and invasion and induced apoptosis of ESCC cells. Mechanistically, Wnt/ß-catenin signaling pathways were actively modulated by SNHG16 in ESCC cells. CONCLUSIONS: Our findings reveal that SNHG16 plays an important role in ESCC proliferation/metastasis via modulating Wnt/ß-catenin signaling pathways and could represent a novel biomarker for predicting poor survival as well a promising therapeutic target.

[Diagnostic value of quantitative pharmacokinetic parameters and relative quantitative pharmacokinetic parameters in breast lesions with dynamic contrast-enhanced MRI].

Objective: To explore the differential between the value of dynamic contrast-enhanced MRI quantitative pharmacokinetic parameters and relative pharmacokinetic quantitative parameters in breast lesions. Methods: Retrospective analysis of 255 patients(262 breast lesions) who was obtained by clinical palpation , ultrasound or full-field digital mammography , and then all lessions were pathologically confirmed in Zhongda Hospital, Southeast University from May 2012 to May 2016. A 3.0 T MRI scanner was used to obtain the quantitative MR pharmacokinetic parameters: volume transfer constant (K(trans)), exchange rate constant (k(ep))and extravascular extracellular volume fraction (V(e)). And measured the quantitative pharmacokinetic parameters of normal glands tissues which on the same side of the same level of the lesions; and then calculated the value of relative pharmacokinetic parameters: rK(rans)、rk(ep) and rV(e).To explore the diagnostic value of two pharmacokinetic parameters in differential diagnosis of benign and malignant breast lesions using receiver operating curves and model of logistic regression. Results: (1)There were significant differences between benign lesions and malignant lesions in K(trans) and k(ep) (t=15.489, 15.022, respectively, P<0.05), there were no significant differences between benign lesions and malignant lesions in V(e)(t=-2.346, P>0.05). The areas under the ROC curve(AUC)of K(trans), k(ep) and V(e) between malignant and benign lesions were 0.933, 0.948 and 0.387, the sensitivity of K(trans), k(ep) and V(e) were 77.1%, 85.0%, 51.0% , and the specificity of K(trans), k(ep) and V(e) were 96.3%, 93.6%, 60.8% for the differential diagnosis of breast lesions if taken the maximum Youden's index as cut-off. (2)There were significant differences between benign lesions and malignant lesions in rK(trans), rk(ep) and rV(e) (t=14.177, 11.726, 2.477, respectively, P<0.05). The AUC of rK(trans), rk(ep) and rV(e) between malignant and benign lesions were 0.963, 0.903 and 0.575, the sensitivity of rK(trans), rk(ep) and rV(e) were 85.6%, 71.9%, 52.9% , and the specificity of rK(trans), rk(ep) and rV(e) were 94.5%, 92.7%, 60.6% for the differential diagnosis of breast lesions.(3)There was no significant difference in the area under the ROC curve between the predictive probability of quantitative pharmacokinetic parameters and the prediction probability of relative quantitative pharmacokinetic parameters(Z=0.867, P=0.195). Conclusion: There was no significant difference between the quantitative parameter values (K(trans,) k(ep)) and the relative quantitative parameter values (rK(trans,) rk(ep)) in diagnosis of breast lesions, which were important parameters in differential diagnosis of benign and malignant breast lesions.

[Effect of nicorandil on ventricular arrhythmia in patients with acute ST-segment elevation myocardial infarction underwent emergent percutaneous coronary intervention treatment].

Objective: To investigate the effect of nicorandil on ventricular arrhythmia in patients with acute ST-segment elevation myocardial infarction (STEMI) treated with emergent percutaneous coronary intervention (PCI). Methods: A total of 120 acute STEMI patients treated with emergent PCI in our hospital from January 2015 to June 2016 were randomly divided into control group and experiment group (n=60 each). Patients in both groups received conventional therapy.Patients in experiment group took 10 mg nicorandil orally before PCI and received oral nicorandil treatment (15 mg/d, three times daily) for 3 days.QT disperse(QTd), correct QTd(QTcd) and the occurrence rate of ventricular arrhythmia were compared between two groups. Results: QTd at 6, 24, 48 and 72 hours((70.6±4.4), (67.2±5.3), (55.7±8.5), (48.2±8.2) ms, respectively) after PCI was significantly lower in the experiment group than those of control group ((77.1±7.1), (71.3±6.5), (65.1±8.1), (57.2±5.4) ms, all P<0.05). The level of QTd was also significantly lower in the experiment group at 6, 24, 48 and 72 hours((77.5±7.7), (67.7±8.6), (61.2±7.5), (52.9±8.4) ms, respectively) after PCI comared to those of control group ((88.6±8.1), (79.2±7.8), (74.4±7.4), (69.6±8.6) ms, all P<0.05). There was no significant difference in the incidence of reperfusion arrhythmia during PCI procedure between the two groups.The prevalence of the ventricular premature beat in the experiment group (25/60, 41.7%) was significantly lower than in the control group(45/60, 75.0%) within 3 days after PCI(P<0.01), the prevalence of the no sustained ventricular tachycardia and ventricular fibrillation in the experiment group(6/60, 10.0%) was also significantly lower than in the control group (18/60, 30.0%, P<0.01) within 3 days after PCI. Conclusions: Nicorandil use prior and post PCI could decrease the occurrence rate of ventricular arrhythmia in STEMI patients undergoing emergent PCI, and this effect might be related with reduced QTd and QTcd post medication.

Critical values in hematology of 862 institutions in China.

INTRODUCTION: A national survey on critical values in hematology of China laboratories was conducted to determine the current practice and assess the quality indicators so as to obtain a quality improvement. METHODS: Laboratories participating were asked to submit the general information, the practice of critical value reporting, and the status of timeliness of critical value reporting. RESULTS: A total of 862 laboratories submitted the results. The majority of participants have included white blood cell count, blood platelet count, hemoglobin, prothrombin time, and activated partial thromboplastin time in their critical value lists. Many sources are used for establishing a critical value policy, and some of the laboratories consult with clinicians. The unreported critical value rate, late critical value reporting rate, and clinically unacknowledged rate in China are relatively low, and the median of critical value reporting time is 8-9 minutes. CONCLUSION: There exists a wide variety for critical value reporting in hematology in China. Laboratories should establish a policy of critical value reporting suited for their own situations and consult with clinicians to set critical value lists. Critical values are generally reported in a timely manner in China, but some measures should be taken to further improve the timeliness of critical value reporting.

Removal of titanium dioxide nanoparticles by coagulation: effects of coagulants, typical ions, alkalinity and natural organic matters.

To investigate the possibility of removing titanium dioxide nanoparticles (TiO2 NPs) from water by coagulation, as well as to find the optimal coagulant and experimental conditions for TiO2 NP removal, four types of coagulant were adopted: polyferric sulfate (PFS), ferric chloride (FeCl3), polyaluminum chloride (PACl), and alum (Al2(SO4)3). It was found that the removal of TiO2 NPs by coagulation was affected by ionic strength, alkalinity, as well as types and dosages of coagulants. PFS and FeCl3 achieved much higher removal efficiency of TiO2 NPs than PACl and Al2(SO4)3 did. For 30 mg/L TiO2 NPs, a dosage of 0.3 mM PFS (as Fe) achieved 84% removal after coagulation followed by 30 min settlement. Optimal ionic strength (0.1 M NaCl or 0.03 M CaCl2) is of vital importance for the performance of PFS. Na2SO4 is unfavorable for the performance of PFS. Optimal alkalinity (0.01-0.03 M NaHCO3) is necessary for FeCl3 to remove TiO2 NPs. Natural organic matter, as represented by humic acid (HA) up to 11 mg/L, reduces the removal of TiO2 NPs by coagulation. These findings indicate that coagulation is a good option for the removal of TiO2 NPs from water, and more attention should be paid to the effects of water quality when using coagulation to remove TiO2 NPs from aqueous matrices. This provides a possible solution to alleviate the potential hazard caused by TiO2 NPs.

Development of microsatellite markers for Mytilus coruscus (Mytilidae), an economically important mussel in the East China Sea.

Twelve new polymorphic microsatellite loci were developed for the hard-shelled mussel, Mytilus coruscus. In 32 individuals from a wild population of coastal Zhoushan, Zhejiang Province, China, the number of alleles at these loci varied from 3 to 15, with a mean of 5.667. The mean observed and expected heterozygosities were 0.6927 and 0.6591, respectively. Among these polymorphic microsatellite loci, three (MC42, MC129, and MC180) significantly deviated from Hardy-Weinberg equilibrium after sequential Bonferroni's correction. All other microsatellite loci were in linkage equilibrium. These microsatellite loci will be useful for detecting genetic differences and for planning aquaculture management of M. coruscus.

Dispersion and stability of titanium dioxide nanoparticles in aqueous suspension: effects of ultrasonication and concentration.

The increasing applications of titanium dioxide (TiO(2)) nanoparticles raise concerns about their potential environmental impacts. To investigate the fate and transport of TiO(2) nanoparticles in aqueous suspension, ultrasonication is widely used for the dispersion of TiO(2) nanoparticles in laboratory-scale studies. There is a pressing need for detailed information on the dispersion and stability of TiO(2) nanoparticles. This study investigated the change of size, zeta potential, and pH of TiO(2) nanoparticles aqueous suspension under different conditions of ultrasonication and concentrations. It was found that the hydrodynamic diameter of TiO(2) nanoparticles decreased with increasing suspension concentration and remained stable for more than 1 hour after sonication, which is enough for experimental research. The pH decreased with increasing nanoparticles concentration. Ultrasonication remarkably improved zeta potential to be above 15 mV for all the samples. Therefore, 20 minutes of ultrasonication (180 W) is sufficient for the dispersion of this rutile TiO(2) nanoparticles suspension, which can remain stable for more than 1 hour. However, the optimum sonication time for TiO(2) nanoparticles dispersion is influenced by many factors, such as TiO(2) nanoparticles concentration, solution chemistry, and sonicator parameters.

Imaging study of the long extracranial extension of the inferior petrosal sinus with MSCT.

The aim of this study was to explore the anatomic route of Long-Inferior Petrosal Sinuses (IPS) with multi-slice spiral computed tomography, and to provide referenced evidence for the interventional preoperative evaluation for the diagnosis and treatment of skull base and sellar lesions. The route of Long-IPS and its confluence with the internal jugular vein (IJV) and the connection level of 12 IPS were shown with multi-planar reconstruction and curved multi-planar reconstruction, and the IPS length was determined. Combining the results of continuous multi-slice scanning, the diameters of the IPS at the initial segment in the jugular foreman and middle segment and the confluence segment of the IPS-IJV junction level were determined. The mean length of the Long-IPS was 66.2 +/- 17.5 mm, and the length was over 60 mm on eight sides and its peak value 100 mm. The mean diameters of the IPS were 2.4 mm +/- 0.7 mm, 2.1 mm +/- 0.4 mm, and 2.1 mm +/- 0.5 mm at the initial, middle, and confluent segments, respectively. Their diameters were equal to or greater than 2 mm at the connection level on eight sides. Furthermore, the diameter was greater than 1.6 mm at the middle and initial segments. The Long-IPS might be used as a route to the intra-cranial IPS. MSCT is helpful for showing the route and variation of the IPS and could be an effective method for preoperative evaluation of the IPS.

Metastability of amorphous silicon from silicon network rebonding.

We propose a network rebonding model for light-induced metastability in amorphous silicon, involving bonding rearrangements of silicon and hydrogen atoms. Nonradiative recombination breaks weak silicon bonds and generates dangling bond-floating bond pairs, with very low activation energies. The transient floating bonds annihilate, generating local hydrogen motion. Charged defects are also found. Support for these processes is found with tight-binding molecular dynamics simulations. The model accounts for major experimental features of the Staebler-Wronski effect including electron-spin resonance data, the t(1/3) kinetics of defect formation, two types of metastable dangling bonds, and hysteretic annealing.

Effects of L-arginine on the proliferation of human renal mesangial cells and production of extracellular matrix.

AIM: To investigate the effect of L-arginine (L-arg) on the proliferation of human mesangial cells and production of collagen. METHODS: The influence of L-arg on the cell proliferation was determined by MTT assay, immunocytochemical detection of expression of proliferative cell nuclear antigen (PCNA), and flow cytometrical analysis of cell cycle. Procollagen III and total collagen level in the supernatant and expression of collagen IV mRNA in human mesangial cells were determined by radioimmunoassay, hydroxyproline colorimetric assay, and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: L-Arg induced inhibition of human mesangial cell lines (HMCL) in a concentration- and time-dependent manner. Immunocytochemical study for PCNA showed the number of cells was decreased, though the percentage of PCNA positive cells was increased in L-arg-treated group. Flow cytometrical analysis showed that cells in S and G2/-M phases were markedly increased in L-arg-treated group compared with those in control group. Furthermore, L-arg significantly inhibited the production of procollagen III and total collagen in the supernatants determined by radioimmunoassay and hydroxyproline colorimetric assay (P < 0.05 and 0.01, respectively) and inhibited the expression of collagen IV mRNA determined by RT-PCR (P < 0.01). CONCLUSION: L-arg could exert an inhibitory effect on the proliferation of human mesangial cells and production of extracellular components, which strongly suggested its potential therapeutic role in the chronic renal scarring.

Skeletal maturity of the hand and wrist in Chinese children in Changsha assessed by TW2 method.

Skeletal maturity of 2122 normal children aged 2-20 years in the southern Chinese city of Changsha have been assessed by the TW2 score method. These mean bone ages are lower than the British standards up to puberty and thereafter higher than the British standards.

[Hybridization experiments using Anopheles minimus from Guangxi and Yunnan].

Hybridization experiments were conducted by forced mating between Anopheles minimus from Guangxi (G) and Yunnan (Y). F1 hybrid females were all fertile with normally developed ovaries. (Y female x G male) F1 males were all sterile, with abnormally enlarged testes. (G female x Y male) F1 males, though fertile, showed somewhat atrophic testes, and when they were back crossed with parental females, the latter produced eggs with very low hatching rate. Ovarian nurse cell polytene chromosomes from F1 hybrid females showed partial asynapsis in X chromosome as well as in autosonles, asynapsis at 38 zone in 3L being the most constant. It was obvious that there was definite, though partial, reproductive isolation between An minimus from Guangxi and that from Yunnan. Whether they are sibling species remains to be further investigated (Figs. 1-8).

[Observation on polytene chromosomes of the ovarian nurse cell of Anopheles minimus from Guangxi].

The ovarian nurse cell's polytene chromosomes of An. minimus exist as 5 arms, the telocentric X chromosome, the submetacentric chromosome 2 and the metacentric chromosome 3. The X chromosome is easily recognized by its length and shuttle-shaped zone 6. The most important characteristics is that each autosome arm has one to three big puffs. Among the 46 zones, 7A, B and 19C in 2R which is the longest arm in the complement, 28A and 20A, B in 2L, 30A, B and 37D in 3R and 46D and 38A, B in 3L are considered as characteristic zones. It is proposed that this map might be considered as the "standard" map of the ovarian nurse cell's polytene chromosomes for An. minimus from Guangxi.