[Clinical characteristics and related factors analysis of adrenal crisis occurred in children with primary nephrotic syndrome].

Objective: To investigate the clinical characteristics and related factors of corticosteroid induced adrenal crisis (AC) in children with primary nephrotic syndrome (NS). Methods: Case control study. The case group included 7 children aged 1 to 18 years with NS combined with AC hospitalized in Peking University First Hospital from January 2016 to May 2021 (AC group). According to the ratio of case group: control group 1: 4, 28 children aged 1 to 18 years who were diagnosed with NS without AC during the same period were matched as controls (non-AC group). Clinical data were collected. The clinical characteristics of AC were described. The clinical parameters were compared between the 2 groups by t test, Mann-Whitney U test or Fisher's test. Receiver operating characteristic (ROC) curve was used to analyze the cutoff values of clinical parameters for prediction of AC. Results: The AC group included 4 boys and 3 girls aged 6.9 (4.6, 10.8) years. The non-AC group included 20 boys and 8 girls aged 5.2 (3.3, 8.4) years. All AC events occurred during the relapse of NS with infection. Seven children had gastrointestinal symptoms such as nausea, vomiting and abdominal pain. Six children had poor mental state or impaired consciousness. No significant differences in NS course, corticosteroid treatment course, corticosteroid type, steroid dosage, steroid medication interval, the proportion of gastroenteritis and fever existed between the two groups (all P>0.05). Compared with the non-AC group, the duration from the onset of the relapse of NS until hospitalization in the AC group was significantly shorter (0.2 (0.1, 0.6) vs. 1.0 (0.4, 5.0) month,U=25.50, P=0.005). The 24 h urinary total protein (UTP) level was significantly higher in the AC group (193 (135, 429) vs. 81 (17, 200) mg/kg, U=27.00,P=0.036) than the non-AC group. The serum albumin level in the AC group was significantly lower((13.1±2.1) vs. (24.5±8.7) g/L,t=-6.22,P<0.001) than the non-AC group. There were significantly higher total white blood cell counts ((26±9)×109 vs. (11±5)×109/L,t=4.26,P=0.004), percentage of neutrophils (0.71±0.08 vs. 0.60±0.19,t=2.56,P=0.017) and the proportion of children with C reactive protein level≥8 mg/L (3/7 vs. 0,P=0.005) in the AC group than in the non-AC group. ROC curve analysis showed that the cutoff value of 24 h UTP was 122 mg/(kg·d) with a sensitivity of 100.0% and specificity of 70.4%. The cutoff value of serum albumin was 17.0 g/L with a sensitivity of 100.0% and specificity of 82.1%. Conclusions: Gastrointestinal symptoms and poor mental state were prominent manifestations of AC in children with NS. High 24 h UTP level, low serum albumin level, high peripheral white blood cell counts, high neutrophils percentage, and high C-reactive protein level during the early stage of NS relapse may be related to the occurrence of AC in children with NS.

[Suitability of estimated urine protein using different estimated 24 h urine creatinine equations in children with glomerular diseases].

Objective: To assess the reliability of estimated urine protein to predict 24 h urine protein excretion in children with glomerular diseases. Methods: Four hundred and forty-three children with glomerular diseases, who were admitted to pediatric department of Peking University First Hospital from January 2001 to December 2021, were enrolled in the cross-sectional study. The 24 h estimated urine creatinine which calculated by 6 previously described equations, 24 h measured urine creatinine, measured urine protein-to-creatinine ratio(UPCR), 24 h urine protein (24 hUP) and urinary sediment analysis with microscopy were collected, estimated urine protein was computed as the product of measured UPCR and estimated or measured 24 h urine creatinine. Spearman correlation analysis, Bland-Altman analysis and linear regression analysis were used to compare the correlation, agreement and accuracy between estimated urine protein and 24 hUP, and the effect of urinary protein level and erythrocyte numbers on their relationship was analyzed. Results: Of 443 children with glomerular diseases (aged (11±4) years, 221 male, 222 female), there were 216 participants with nephrotic syndrome, 78 participants with IgA nephropathy, 47 participants with Alport syndrome, 42 participants with lupus nephritis, 58 participants with purpura nephropathy, and 2 participants with isolated proteinuria. Spearman correlation analysis showed a strong correlation between estimated urine protein and 24 hUP (r=0.90, P<0.05), and the correlation improved after multiplying the measured UPCR by 24 h measured urine creatinine (r=0.94, P<0.05). Improved correlation was also observed using the estimated urine creatinine which calculated by Hellerstein formula, Ghazali-Barratt formula, Ellam formula, Walser formula, Cockcroft-Gault formula, Ix formula (r=0.93, 0.94, 0.90, 0.90, 0.94, 0.93, all P<0.05).Bland-altman analysis showed that the difference between measured UPCR and 24 hUP was (-0.30±2.22) g, consistency limit was -4.65-4.04, and the consistency improved after 24 h measured urine creatinine correction (difference was (0.27±1.31) g, consistency limit -2.30-2.84). The consistency of estimated urine protein was further improved after correction by different formulas, and the Cockcroft-Gault formula showed the best consistency between estimated urine protein and 24 hUP (difference was (0.11±1.18)g, consistency limit was -2.20-2.42). Linear regression analysis showed that measured UPCR had poor accuracy in predicting 24 hUP (R2=0.55, α=0.48, ß=0.60, P<0.05), and the accuracy improved after 24 h measured urine creatinine correction, the accuracy of estimated urine protein for predicting 24 hUP was further improved by using different formulas, and Cockcroft-Gault formula was the best (R2=0.81, α=0.18, ß=0.96, P<0.05). With the increase of urinary protein level and the decrease of urinary erythrocyte numbers, the correlation, agreement and accuracy between estimated urine protein and measured UPCR and 24 hUP were improved(all P<0.05). Except Ellam and Ix formulas, estimated urine protein using the rest four formulas outperformed measured UPCR(all P<0.05). Conclusion: The 24 h urine creatinine excretion rate (obtained by the Cockcroft-Gault equation)-weighted urine protein-to-creatinine ratio more reliably predicts 24 hUP than measured UPCR alone in children with glomerular diseases.

[C1q or IgA deposition in glomeruli of children with primary membranous nephropathy].

Objective: To assess the correlation of glomerular C1q or IgA deposition with clinical and pathological features of primary membranous nephropathy (PMN) in children. Methods: The clinical and pathological manifestations including (phospholipase A2 receptor, PLA2R) and IgG subclasses staining in renal biopsies, serum anti-PLA2R antibody and therapeutic response of 33 children diagnosed with PMN in Peking University First Hospital from December 2012 to December 2020 were retrospectively summarized and analyzed. According to results of PLA2R test and findings renal pathological, the patients were divided into PLA2R-related group and non-PLA2R-related group, typical MN group and atypical MN group, C1q deposit group and non-C1q deposit group, as well as IgA deposit group and non-IgA deposit group respectively. T-test, Mann-Whitney U test and Fisher's exact probability test were used for comparison between the groups. Results: Among the 33 children with PMN, there were 20 males and 13 females, of that the age of onset was 11 (8, 13) years, and 32 patients had nephrotic level proteinuria. Renal biopsies were performed at 4.6 (2.1, 11.6) months after onset, and 28 patients (85%) received glucocorticoid or immunosuppressive therapy prior to renal biopsy. There were 20 cases (61%) with PLA2R-related MN and 13 cases (39%) with non-PLA2R-related MN. Compared with the non-PLA2R-related group, the PLA2R-related group had an older age of onset (12 (10, 13) vs. 7 (3, 12) years, Z=-2.52, P=0.011), a lower preceding infection rate (45% (9/20) vs. 11/13, P=0.032) and lower spontaneous remission rate (0 vs. 4/13, P=0.017). Renal PLA2R positivity was significantly associated with predominant or co-deposition of IgG4 (13/17 vs. 5/15, P=0.031) and low albumin levels at renal biopsy ((25±6) vs. (29±7) g/L, t=2.14, P=0.041). There were 12 patients with typical PMN and 21 patients with atypical PMN, and no significant difference in clinical and pathological manifestations was found between these 2 groups (all P>0.05). There were 10 cases (32.3%) with glomerular C1q deposition, and their disease course before renal biopsy was significantly shorter than those without C1q deposition (1.8 (0.8, 5.9) vs. 6.0 (2.5, 22.3) months, Z=-2.27, P=0.023). Twelve cases (36.4%) had glomerular IgA deposition, and their course of disease,clinical and pathological manifestations were not significantly different from those without IgA deposition (all P>0.05). Conclusion: Glomerular C1q or IgA deposition may not affect the clinical manifestations, glomerular PLA2R and IgG subclasses staining pattern, or the response to treatment of PMN in children.

Copy Number Variations Analysis Identifies QPRT as a Candidate Gene Associated With Susceptibility for Solitary Functioning Kidney.

BACKGROUND: The lack of understanding of molecular pathologies of the solitary functioning kidney makes improving and strengthening the continuity of care between pediatric and adult nephrological patients difficult. Copy number variations (CNVs) account for a molecular cause of solitary functioning kidney, but characterization of the pathogenic genes remains challenging. METHODS: In our prospective cohort study, 99 fetuses clinically diagnosed with a solitary functioning kidney were enrolled and evaluated using chromosomal microarray analysis (CMA). The genetic drivers for the pathogenic CNVs were analyzed. We characterized QPRT localization in fetal kidneys using immunohistochemistry and its expression in adult kidneys using quantitative RT-PCR. Further, QPRT was knocked down using siRNA in human embryonic kidney (HEK293T) cells, and the cell cycle and proliferation were tested. RESULTS: Besides one Triple X syndrome and one Down syndrome, we identified a total of 45 CNVs out of 34 subjects. Among the 14 pathogenic CNVs, CNV 16p11.2 reached the highest number of records with the phenotype of kidney anomalies in the Decipher database. Among the 26 genes within the 16p11.2 region, as a key enzyme for nicotinamide adenine dinucleotide (NAD+) biosynthesis, QPRT was distinctly localized in renal tubules but was barely observed in renal interstitial and glomeruli in fetal kidneys. The loss of QPRT prevented cells' efficient transition into S phase, affected cell-cycle progression, and abrogated proliferation of human embryonic kidney cells. CONCLUSION: Our data suggest that QPRT is a candidate gene associated with susceptibility for solitary functioning kidney. The CNVs discovered in our study exhibit great potential for future applications in genetic counseling and pregnancy management.

Correlated optical and electrical analyses of inhomogeneous core/shell InGaN/GaN nanowire light emitting diodes.

The performance of core-shell InGaN/GaN nanowire (NW) light emitting diodes (LEDs) can be limited by wire-to-wire electrical inhomogeneities. Here we investigate an array of core-shell InGaN/GaN NWs which are morphologically identical, but present electrical dissimilarities in order to understand how the nanoscale phenomena observed in individual NWs affect the working performance of the whole array. The LED shows a low number of NWs (∼20%) producing electroluminescence under operating conditions. This is related to a presence of a potential barrier at the interface between the NW core and the radially grown n-doped layer, which differently affects the electrical properties of the NWs although they are morphologically identical. The impact of the potential barrier on the performance of the NW array is investigated by correlating multi-scanning techniques, namely electron beam induced current microscopy, electroluminescence mapping and cathodoluminescence analysis. It is found that the main cause of inhomogeneity in the array is related to a non-optimized charge injection into the active region, which can be overcome by changing the contact architecture so that the electrons become injected directly in the n-doped underlayer. The LED with so-called 'front-n-contacting' is developed leading to an increase of the yield of emitting NWs from 20% to 65%.

Adoption of enterprise architecture for healthcare in AeHIN member countries.

BACKGROUND: Healthcare organisations are undergoing a major transformational shift in the use of information and digital health technologies. Enterprise architecture (EA) has been incrementally adopted in many healthcare organisations globally to facilitate this change. EA can increase the effectiveness of an organisation's digital health capabilities and resources. However, little is known about the status of EA adoption in low-income and middle-income countries. This study aimed to evaluate the challenges, goals and benefits associated with adoption of EA for healthcare in the Asia eHealth Information Network (AeHIN) member countries . METHODS: We developed an EA Adoption Evaluation framework with four principal layers: governance, strategy, EA and performance. The framework guided the development of a questionnaire to investigate the goals, challenges and benefits faced before and during EA adoption by healthcare organisations. SAMPLE: 26 participants from 18 healthcare organisations in the Asia-Pacific region representing 11 countries. Organisations included Ministries of Health, Universities, Non-Governmental Organisations and Technical Advisory Groups. FINDINGS: Only 5 of the 18 organisations had begun adopting EA. The goals expressed for EA adoption were to address issues such as interoperability, lack of technical infrastructure and poor alignment of business and information technology strategies. Cost reduction was less emphasised. The main challenges to adopting EA was the lack of EA knowledge, leadership and involvement of senior management. CONCLUSION: The adoption of EA is incipient in AeHIN member healthcare organisations. To encourage EA adoption, these organisations need to invest in internal capacity building, senior management training and seek independent EA expert advice to systematically identify and address the barriers to adopting EA.

Comparison of the cohort selection performance of Australian Medicines Terminology to Anatomical Therapeutic Chemical mappings.

OBJECTIVE: Electronic health records are increasingly utilized for observational and clinical research. Identification of cohorts using electronic health records is an important step in this process. Previous studies largely focused on the methods of cohort selection, but there is little evidence on the impact of underlying vocabularies and mappings between vocabularies used for cohort selection. We aim to compare the cohort selection performance using Australian Medicines Terminology to Anatomical Therapeutic Chemical (ATC) mappings from 2 different sources. These mappings were taken from the Observational Medical Outcomes Partnership Common Data Model (OMOP-CDM) and the Pharmaceutical Benefits Scheme (PBS) schedule. MATERIALS AND METHODS: We retrieved patients from the electronic Practice Based Research Network data repository using 3 ATC classification groups (A10, N02A, N06A). The retrieved patients were further verified manually and pooled to form a reference standard which was used to assess the accuracy of mappings using precision, recall, and F measure metrics. RESULTS: The OMOP-CDM mappings identified 2.6%, 15.2%, and 24.4% more drugs than the PBS mappings in the A10, N02A and N06A groups respectively. Despite this, the PBS mappings generally performed the same in cohort selection as OMOP-CDM mappings except for the N02A Opioids group, where a significantly greater number of patients were retrieved. Both mappings exhibited variable recall, but perfect precision, with all drugs found to be correctly identified. CONCLUSION: We found that 1 of the 3 ATC groups had a significant difference and this affected cohort selection performance. Our findings highlighted that underlying terminology mappings can greatly impact cohort selection accuracy. Clinical researchers should carefully evaluate vocabulary mapping sources including methodologies used to develop those mappings.

Long non-coding RNA H19 regulates the development of gliomas through the Wnt/ß-catenin signaling pathway.

OBJECTIVE: We investigated the effects of long non-coding RNA (lncRNA) H19 on glioma cell proliferation, invasion, migration, and apoptosis and the underlying mechanisms. PATIENTS AND METHODS: H19 expression in glioma tissues, para-carcinoma tissues, and glioma cell lines was analyzed by Real-time polymerase chain reaction (RT-PCR). After transfecting U251 and U87MG cells with siRNA-H19, cell proliferation was detected by the cell counting kit-8 (CCK8) assay. Invasion and migration were detected by a transwell assay; cell cycle distribution and apoptosis were measured by flow cytometry analysis; Dvl2, GSK-3ß, cyclin D1, and ß-catenin expressions were detected by RT-PCR and Western blotting. RESULTS: H19 expression in glioma tissues was higher than that in para-carcinoma tissues and associated with poor prognosis in glioma patients. Cell proliferation, invasion, and migration significantly decreased, the percentage of glioma cells in G0/G1 significantly increased, the percentage of glioma cells in the S phase significantly decreased, and apoptosis significantly increased in U251 and U87MG cells transfected with siRNA-H19 compared to those in the siRNA-NC group. Downregulation of H19 decreased DVL2, cyclin D1, and ß-catenin expression and increased GSK-3ß expression. The inhibitory effects of downregulation of H19 on glioma cell proliferation, invasion, and migration were reversed by SKL2001 via the activation of the Wnt/ß-catenin signal pathway, which was further enhanced by inhibition of the Wnt/ß-catenin signal pathway by XAV939. CONCLUSIONS: H19 was overexpressed in glioma tissues and glioma cell lines. Downregulation of H19 inhibited cell proliferation, invasion, and migration, arrested cell cycle progression in the G0/G1 phase, and induced cell apoptosis by restraining activation of the Wnt/ß-catenin signaling pathway in glioma cells. Therefore, H19 is a potential therapeutic target for glioma therapy.

Optical properties of GaN nanowires grown on chemical vapor deposited-graphene.

Optical properties of GaN nanowires (NWs) grown on chemical vapor deposited-graphene transferred on an amorphous support are reported. The growth temperature was optimized to achieve a high NW density with a perfect selectivity with respect to a SiO2 surface. The growth temperature window was found to be rather narrow (815°C ± 5°C). Steady-state and time-resolved photoluminescence from GaN NWs grown on graphene was compared with the results for GaN NWs grown on conventional substrates within the same molecular beam epitaxy reactor showing a comparable optical quality for different substrates. Growth at temperatures above 820 °C led to a strong NW density reduction accompanied with a diameter narrowing. This morphology change leads to a spectral blueshift of the donor-bound exciton emission line due to either surface stress or dielectric confinement. Graphene multi-layered micro-domains were explored as a way to arrange GaN NWs in a hollow hexagonal pattern. The NWs grown on these domains show a luminescence spectral linewidth as low as 0.28 meV (close to the set-up resolution limit).

ß-Glucan attenuates inflammatory responses in oxidized LDL-induced THP-1 cells via the p38 MAPK pathway.

AIM: To investigate the immunomodulatory effects of ß-(1,3/1,6)-d-glucan on atherosclerosis as well as on the molecular mechanisms of its transition. METHODS AND RESULTS: Human monocytic leukemia (THP-1) cells were differentiated into the macrophage phenotype by incubation with oxLDL in the absence or presence of ß-glucan. ß-glucan attenuated CD86 and CD80 expression and simultaneously reduced secretion of the inflammatory cytokines IL-2, IL-8, IL-12, TNF-α and IFN-γ. Western blot analysis showed that oxLDL treatment induced phosphorylation of p38 MAPK and ERK1/2 in PMA-differentiated THP-1 cells. However, ß-glucan inhibited p38 MAPK activation. In experiments with monocytes derived from healthy donors, ß-glucan inhibited IL-8, IL-12 and TNF-α production. The anti-inflammatory effects of ß-glucan were also observed in atherosclerotic plaque cells. CONCLUSIONS: ß-glucan inhibited oxLDL-induced pro-inflammatory effects in macrophages via regulation of p38 MAPK phosphorylation. This novel finding may provide insight for new therapeutic strategies.

NFU-Enabled FASTA: moving bioinformatics applications onto wide area networks.

BACKGROUND: Advances in Internet technologies have allowed life science researchers to reach beyond the lab-centric research paradigm to create distributed collaborations. Of the existing technologies that support distributed collaborations, there are currently none that simultaneously support data storage and computation as a shared network resource, enabling computational burden to be wholly removed from participating clients. Software using computation-enable logistical networking components of the Internet Backplane Protocol provides a suitable means to accomplish these tasks. Here, we demonstrate software that enables this approach by distributing both the FASTA algorithm and appropriate data sets within the framework of a wide area network. RESULTS: For large datasets, computation-enabled logistical networks provide a significant reduction in FASTA algorithm running time over local and non-distributed logistical networking frameworks. We also find that genome-scale sizes of the stored data are easily adaptable to logistical networks. CONCLUSION: Network function unit-enabled Internet Backplane Protocol effectively distributes FASTA algorithm computation over large data sets stored within the scaleable network. In situations where computation is subject to parallel solution over very large data sets, this approach provides a means to allow distributed collaborators access to a shared storage resource capable of storing the large volumes of data equated with modern life science. In addition, it provides a computation framework that removes the burden of computation from the client and places it within the network.

The relationship among nephrin, podocin, CD2AP, and alpha-actinin might not be a true 'interaction' in podocyte.

The abnormality of a single podocyte molecule, caused by a single gene mutation, such as NPHS1, NPHS2, CD2AP, and ACTN4, can lead to the hereditary/congenital nephrotic syndromes (NS). Further studies suggested that more than one podocyte molecule were together involved in acquired or experimental NS. However, we do not know much on the relationship among these podocyte molecules, and the molecular response induced by the change of each podocyte protein to the remaining ones. We respectively knockdown the nephrin, podocin, CD2AP, or alpha-actinin-4 mRNA by using reconstructed RNA interference vector--psiRNA-hH1GFPzeo in mouse podocyte clone. The molecular behavior or response was revealed by the quantitative expression both at mRNA and protein levels with RT-PCR and Western blot, and by the molecular distribution detected with confocal microscopy. With nephrin knockdown, only CD2AP increased, whereas podocin showed no change. Contrarily, with podocin or CD2AP knockdown, nephrin decreased, while CD2AP or podocin increased. Nephrin, podocin, or CD2AP knockdown did not change the expression of alpha-actinin-4, whereas alpha-actinin-4 knockdown begetted the reduction of nephrin, and the increment of podocin and CD2AP. The redistributions of nephrin, podocin, and CD2AP were revealed around a predominant nuclear staining compared with the membrane surface staining in the control podocytes. Our data imply that the response between the four podocyte molecules is very complicated and evidently different. There is not always an interaction between podocyte molecules. The normal localization of podocyte molecules would depend on their normal expression quantity and the molecular reactions between them.

Sol-gel technique for the preparation of beta-cyclodextrin derivative stationary phase in open-tubular capillary electrochromatography.

A novel open-tubular capillary electrochromatography (OT-CEC) column coated with 2,6-dibutyl-beta-cyclodextrin (DB-beta-CD) was prepared using sol-gel technique. In the sol-gel approach, owing to the three-dimensional network of sol-gel and the strong chemical bond between the stationary phase and the surface of capillary columns, good chromatographic characteristics and unique selectivity in separating isomers were shown. We achieved high efficiencies of 5-14 x 10(4) plates/m for the isomeric nitrophenols using the sol-gel-derived DB-beta-CD columns. The migration time reproducibility of the separation of the isomeric nitrophenols was better than 2.2% over five runs and 4.5% from column to column. These sol-gel-coated DB-beta-CD columns have shown improved separations of isomeric aminophenols, isomeric dihydroxybenzenes and isomeric nitrophenols, in comparison with the sol-gel matrix capillary column. The influences of buffer pH and methanol solvent on separation were investigated. The chiral resolution of enantiomers such as ibuprofen and binaphthol was explored primarily.

The FAD binding sites of human liver monoamine oxidases A and B: investigation of the role of flavin ribityl side chain hydroxyl groups in the covalent flavinylation reaction and catalytic activities.

The role of ribityl side chain hydroxyl groups of the flavin moiety in the covalent flavinylation reaction and catalytic activities of recombinant human liver monoamine oxidases (MAO) A and B have been investigated using the riboflavin analogue: N(10)-omega-hydroxypentyl-isoalloxazine. Using a rib5 disrupted strain of Saccharomyces cerevisiae which is auxotrophic for riboflavin, MAO A and MAO B were expressed separately under control of a galactose inducible GAL10/CYC1 promoter in the presence of N(10)-omega-hydroxypentyl-isoalloxazine as the only available riboflavin analogue. Analysis of mitochondrial membrane proteins shows both enzymes to be expressed at levels comparable to those cultures grown on riboflavin and to contain covalently bound flavin. Catalytic activities, as monitored by kynuramine oxidation, are equivalent to (MAO A) or 2-fold greater (MAO B) than control preparations expressed in the presence of riboflavin. Although N(10)-omega-hydroxypentyl-isoalloxazine is unable to support growth of riboflavin auxotrophic S. cerevisiae, it is converted to the FMN level by yeast cell free extracts. The FMN form of the analogue is converted to the FAD level by the yeast FAD synthetase, as shown by expression of the recombinant enzyme in Escherichia coli. These data show that the ribityl hydroxyl groups of the FAD moiety are not required for covalent flavinylation or catalytic activities of monoamine oxidases A and B. This is in contrast to the suggestion based on mutagenesis studies that an interaction between the 3'-hydroxyl group of the flavin and the beta-carbonyl of Asp(227) is required for the covalent flavinylation reaction of MAO B (Zhou et al., J. Biol. Chem. 273 (1998) 14862-14868).

Effective amplification of 20-kb DNA by reverse transcription PCR.

Polymerase chain reaction has been applied to the amplification of long DNA fragments from a variety of sources, including genomic, mitochondrial, and viral DNAs. However, polymerase chain reaction amplification from cDNA templates produced by reverse transcription has generally been restricted to products of less than 10 kilobases. In this paper, we report a system to effectively amplify fragments up to 20 kilobases from human coronavirus 229E genomic RNA. We demonstrate that the integrity of the RNA template and the prevention of false priming events during reverse transcription are the critical parameters to achieve the synthesis of long cDNAs. The optimization of the polymerase chain reaction conditions enabled us to improve the specificity and yield of product but they were not definitive. Finally, we have shown that the same reverse transcription polymerase chain reaction technology can be used for the amplification of extended regions of the dystrophin mRNA, a cellular RNA of relatively low abundance.

Epstein-Barr virus-derived plasmids replicate only once per cell cycle and are not amplified after entry into cells.

Some possible ways in which replication of plasmids containing the Epstein-Barr virus (EBV) plasmid maintenance origin, oriP, might be controlled were investigated. Virtually all plasmid molecules were found to replicate no more than once per cell cycle, whether replication was observed after stable introduction of the plasmids into cells by drug selection or during the first few cell divisions after introducing the DNA into cells. The presence in the cells of excess amounts of EBNA1, the only viral protein needed for oriP function, did not increase the number of oriP-replicated plasmids maintained by cells under selection. In the cell lines studied, EBNA1 and oriP seem to lack the capacity to override the cellular controls that limit DNA replication to one initiation event per DNA molecule per S phase. The multicopy status of EBV-derived, selectable plasmids appears to result from the initial uptake by cells of large numbers of plasmid molecules, the efficient maintenance of these plasmids, and the pressure of genetic selection against plasmid loss. Other unknown controls must be responsible for the amplification of EBV genomes soon after latent infection of cells.

[A study of carcinogenicity skin of extracts from different size particles in air].

The article presents the experimental results on mice skin Tumor-initiating test of extracts of air particles collected from Beijing, Taiyuan and Xuanwei. In this experiment, we use extracts as initiators. The results show that extracts from different size particles all have the positive carcinogenicity, however, there exists a close relationship between the size of particles and carcinogenicity, that is, the extract from the smaller size particles has stronger carcinogenicity.