[Emphasizing the timing and procedure selection for vitrectomy in pathological myopic traction maculopathy].

Myopic maculopathy is the primary cause of irreversible visual impairment in patients with pathologic myopia, and myopic traction maculopathy often requires vitrectomy for treatment. Myopic traction maculopathy encompasses epiretinal membrane, foveoschisis, macular hole, and macular hole-related retinal detachment. It is recommended to perform vitrectomy combined with inner limiting membrane peeling for Type II epiretinal membrane, foveal-sparing inner limiting membrane peeling for foveoschisis, inverted inner limiting membrane flap technique for macular hole, and vitrectomy combined with macular buckle for refractory macular hole-related retinal detachment. Myopic traction maculopathy is a chronically progressive condition, and surgeons need to accurately determine the timing of surgery and choose appropriate procedures to maximize the benefits for patients.

[Preliminary study on automatic quantification and grading of leopard spots fundus based on deep learning technology].

Objective: To achieve automatic segmentation, quantification, and grading of different regions of leopard spots fundus (FT) using deep learning technology. The analysis includes exploring the correlation between novel quantitative indicators, leopard spot fundus grades, and various systemic and ocular parameters. Methods: This was a cross-sectional study. The data were sourced from the Beijing Eye Study, a population-based longitudinal study. In 2001, a group of individuals aged 40 and above were surveyed in five urban communities in Haidian District and three rural communities in Daxing District of Beijing. A follow-up was conducted in 2011. This study included individuals aged 50 and above who participated in the second 5-year follow-up in 2011, considering only the data from the right eye. Color fundus images centered on the macula of the right eye were input into the leopard spot segmentation model and macular detection network. Using the macular center as the origin, with inner circle diameters of 1 mm, 3 mm, and outer circle diameter of 6 mm, fine segmentation of the fundus was achieved. This allowed the calculation of the leopard spot density (FTD) and leopard spot grade for each region. Further analyses of the differences in ocular and systemic parameters among different regions' FTD and leopard spot grades were conducted. The participants were categorized into three refractive types based on equivalent spherical power (SE): myopia (SE<-0.25 D), emmetropia (-0.25 D≤SE≤0.25 D), and hyperopia (SE>0.25 D). Based on axial length, the participants were divided into groups with axial length<24 mm, 24-26 mm, and>26 mm for the analysis of different types of FTD. Statistical analyses were performed using one-way analysis of variance, Kruskal-Wallis test, Bonferroni test, and Spearman correlation analysis. Results: The study included 3 369 participants (3 369 eyes) with an average age of (63.9±10.6) years; among them, 1 886 were female (56.0%) and 1, 483 were male (64.0%). The overall FTD for all eyes was 0.060 (0.016, 0.163); inner circle FTD was 0.000 (0.000, 0.025); middle circle FTD was 0.030 (0.000, 0.130); outer circle FTD was 0.055 (0.009, 0.171). The results of the univariate analysis indicated that FTD in various regions was correlated with axial length (overall: r=0.38, P<0.001; inner circle: r=0.31, P<0.001; middle circle: r=0.36, P<0.001; outer circle: r=0.39, P<0.001), subfoveal choroidal thickness (SFCT) (overall: r=-0.69, P<0.001; inner circle: r=-0.57, P<0.001; middle circle: r=-0.68, P<0.001; outer circle: r=-0.72, P<0.001), age (overall: r=0.34, P<0.001; inner circle: r=0.30, P<0.001; middle circle: r=0.31, P<0.001; outer circle: r=0.35, P<0.001), gender (overall: r=-0.11, P<0.001; inner circle: r=-0.04, P<0.001; middle circle: r=-0.07, P<0.001; outer circle: r=-0.11, P<0.001), SE (overall: r=-0.20; P<0.001; inner circle: r=-0.19, P<0.001; middle circle: r=-0.20, P<0.001; outer circle: r=-0.20, P<0.001), uncorrected visual acuity (overall: r=-0.18, P<0.001; inner circle: r=-0.26, P<0.001; middle circle: r=-0.24, P<0.001; outer circle: r=-0.22, P<0.001), and body mass index (BMI) (overall: r=-0.11, P<0.001; inner circle: r=-0.13, P<0.001; middle circle: r=-0.14, P<0.001; outer circle: r=-0.13, P<0.001). Further multivariate analysis results indicated that different region FTD was correlated with axial length (overall: ß=0.020, P<0.001; inner circle: ß=-0.022, P<0.001; middle circle: ß=0.027, P<0.001; outer circle: ß=0.022, P<0.001), SFCT (overall: ß=-0.001, P<0.001; inner circle: ß=-0.001, P<0.001; middle circle: ß=-0.001, P<0.001; outer circle: ß=-0.001, P<0.001), and age (overall: ß=0.002, P<0.001; inner circle: ß=0.001, P<0.001; middle circle: ß=0.002, P<0.001; outer circle: ß=0.002, P<0.001). The distribution of overall (H=56.76, P<0.001), inner circle (H=72.22, P<0.001), middle circle (H=75.83, P<0.001), and outer circle (H=70.34, P<0.001) FTD differed significantly among different refractive types. The distribution of overall (H=373.15, P<0.001), inner circle (H=367.67, P<0.001), middle circle (H=389.14, P<0.001), and outer circle (H=386.89, P<0.001) FTD differed significantly among different axial length groups. Furthermore, comparing various levels of FTD with systemic and ocular parameters, significant differences were found in axial length (F=142.85, P<0.001) and SFCT (F=530.46, P<0.001). Conclusions: The use of deep learning technology enables automatic segmentation and quantification of different regions of theFT, as well as preliminary grading. Different region FTD is significantly correlated with axial length, SFCT, and age. Individuals with older age, myopia, and longer axial length tend to have higher FTD and more advanced FT grades.

Genome-wide association study reveals a quantitative trait locus and two candidate genes on Sus scrofa chromosome 5 affecting intramuscular fat content in Suhuai pigs.

Intramuscular fat content (IFC) is an essential quantitative trait of meat, affecting multiple meat quality indicators. A certain amount of IFC could not only improve the sensory score of pork but also increase the flavour, tenderness, juiciness and shelf-life. To dissect the genetic determinants of IFC, two methods, including genome-wide efficient mixed-model analysis (GEMMA) and linkage disequilibrium adjusted kinships (LDAKs), were used to carry out genome-wide association studies for IFC in Suhuai pig population. A total of 14 and 18 significant single nucleotide polymorphisms (SNPs) were identified by GEMMA and LDAK, respectively. The results of these two methods were highly consistent and all 14 significant SNPs in GEMMA were detected by LDAK. Seven of the 18 SNPs reached the genome-wide significance level (P < 9.85E-07) while 11 cases reached the suggestive significance level (P < 1.77E-05). These significant SNPs were mainly distributed on Sus scrofa chromosome (SSC) 5, 3, and 7. Moreover, one locus resides in a 2.27 Mb (71.37-73.64 Mb) region on SSC5 harbouring 13 significant SNPs associated with IFC, and the lead SNP (rs81302978) also locates in this region. Linkage disequilibrium (LD) analysis showed that there were four pairs of complete LD (r2 = 1) among these 13 SNPs, and the remaining 9 SNPs with incomplete LD (r2 ≠ 1) were selected for subsequent analyses of IFC. Association analyses showed that 7 out of 9 SNPs were significantly associated with IFC (P < 0.05) in 330 Suhuai pigs, and the other 2 SNPs tended to reach a significant association level with IFC (P < 0.1). The phenotypic variance explained (PVE) range of these 9 SNPs was 0.92-3.55%. Meanwhile, the lead SNP was also significantly associated (rs81302978) with IFC (P < 0.05) in 378 commercial hybrid pigs (Pietrain × Duroc) × (Landrace × Yorkshire) (PDLY), and the PVE was 1.38%. Besides, two lipid metabolism-relevant candidate genes, the leucine rich repeat kinase 2 (LRRK2) and PDZ domain containing ring finger 4 (PDZRN4) were identified in the 2.27 Mb region on SSC5. In conclusion, our results may provide a set of markers useful for genetic improvement of IFC in pigs and will advance the genome selection process of IFC on pig breeding programmes.

Elevated circulating miR-494 in plasma of children with enterovirus 71 induced hand, foot, and mouth disease and its potential diagnostic value.

Hand, foot, and mouth disease (HFMD) is a common pediatric disease, whose outcome depends of the enterovirus genotype infecting the patient. The present study is focused on the potential diagnostic value and the role of circulating microRNA-494 (miR-494) in enterovirus 71-induced more severe form of HFMD. We included 102 children with enterovirus 71 (EV71)-induced HFMD, 42 coxsackievirus A16 (CA16)-induced HFMD and 102 healthy controls. The plasma and serum samples were collected. The expression level of circulating miR-494 was determined by RT-PCR method. Moreover, ROC curve has been drawn to evaluate the sensitivity and specificity of circulating miR-494 for the diagnosis of EV71-induced HFMD. Furthermore, the correlation between the circulating miR-494 and the levels of interleukin 6 (IL-6), interleukin 4 (IL-4) and interferon γ (IFN-γ) in the serum of patients were analyzed. Circulating miR-494 was significantly increased in plasma of children with EV71-induced HFMD compared with the healthy children or CA16-induced HFMD, and level of miR-494 in the EV71 severe group was significantly higher than the EV71 mild group. Moreover, results of ROC analysis suggested that miR-494 is a sensitive biomarker to distinguish EV71 patients from healthy controls and CA16 patients. Furthermore, IL-6 and IFN-γ were elevated in serum of patients with EV71-induced HFMD and the level of circulating miR-494 in patients with EV71-induced HFMD was positively correlated with the serum levels of both IL-6 and IFN-γ, respectively. Circulating miR-494 was abnormally up-regulated in plasma of the children with EV71-induced HFMD, and miR-494 may serve as potential biomarker for the diagnosis and treatment of the disease. Keywords: miR-494; HFMD; biomarker; enterovirus 71; inflammation.

MicroRNA 34b inhibits cell proliferation in pediatric acute myeloid leukemia via regulating LDHA.

OBJECTIVE: To elucidate the regulatory effect of microRNA-34b on the occurrence of pediatric acute myeloid leukemia and the underlying mechanism. PATIENTS AND METHODS: The expression of microRNA-34b in the bone marrow of 72 children with newly diagnosed acute myeloid leukemia (AML) was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between microRNA-34b expression and pathological characteristics was analyzed. Kaplan-Meier curve was introduced for evaluating the prognostic value of microRNA-34b in pediatric AML. The regulatory effects of microRNA-34b on proliferation, cell cycle, and apoptosis of leukemia cells were accessed by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Bioinformatics prediction and dual-luciferase reporter gene assay were conducted to evaluate the binding between microRNA-34b and lactate dehydrogenase A (LDHA). LDHA expression after overexpression of microRNA-34b was determined by qRT-PCR and Western blot. Rescue experiments were conducted to verify whether microRNA-34b could regulate proliferative and apoptotic behaviors of leukemia cells by suppressing LDHA expression. RESULTS: MicroRNA-34b was markedly downregulated in AML children. Low expression of microRNA-34b was correlated to FAB typing, cytogenetic abnormality, and day 7 response to the treatment of pediatric AML. By collecting the follow-up data, it was found that low expression of microRNA-34b was correlated to the poor prognosis of AML. Overexpression of microRNA-34b inhibited proliferative ability and cell cycle progression, but accelerated apoptosis of AML cells. Dual-luciferase reporter gene assay verified that microRNA-34b could bind to LDHA, thereafter inhibiting LDHA expression. Overexpression of LDHA reversed the regulatory effects of microRNA-34b on proliferation, cell cycle, and apoptosis of AML cells. CONCLUSIONS: We found that microRNA-34b is lowly expressed in pediatric AML patients, and low expression of microRNA-34b may serve as an indicator of malignant progression and poor prognosis of pediatric AML. MicroRNA-34b may affect the proliferation and apoptosis of leukemia cells by regulating the expression of LDHA.

The phytoestrogen daidzein may affect reproductive performance of Zhedong White geese by regulating gene mRNA levels in the HPG axis.

1. The effect of daidzein, a naturally occurring phytoestrogen, on the reproductive performance of 120 female Zhedong White geese was determined. The geese were divided into 4 groups which were fed on diets containing 0 (Control), 10 (Da1), 20 (Da2) and 30 (Da3) mg daidzein per kg diet. Egg production and weight, fertility and hatchability rates, concentrations of estradiol (E2), triiodothyronine (T3), progesterone (P4), thyroxine (T4) and growth hormone (GH) in serum, and mRNA levels of gonadotropin releasing hormone (GnRH), ß-follicle stimulating hormone (FSHß), follicle stimulating hormone receptor (FSHR), oestrogen receptor1 (ESR1), oestrogen receptor2 (ESR2), prolactin (PRL), prolactin receptor (PRLR), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in the hypothalamus-pituitary-gonadal axis (HPGA) were measured. 2. Daidzein increased egg weight and fertility but had no detectable effect on egg production and hatchability. 3. Daidzein affected serum P4 and GH concentrations and T4 rhythm, up-regulated GnRH mRNA and PRLR mRNA levels in the hypothalamus, down-regulated PRLR mRNA in the hypothalamus, PRL mRNA in the pituitary, and ESR2 mRNA levels in the ovary, respectively. The mRNA rhythms of PRLR in the hypothalamus, PRL, PRLR and FSHß in the pituitary, FSHR, ESR1 and ESR2 in the ovary were significantly changed in the Da2 group. 4. It is suggested that an appropriate dose of daidzein might improve reproductive performance by affecting serum hormone concentrations and rhythms and regulating gene mRNA levels in the HPGA of female Zhedong White geese.

Effects of alfalfa meal on growth performance and gastrointestinal tract development of growing ducks.

A study was conducted to evaluate effects of alfalfa meal on growth performance and gastrointestinal tract development of growing layer ducks to provide evidence for application of alfalfa meal in the duck industry. Two hundred and fifty-six healthy Shaoxing 7-wk old growing layer ducks were selected and randomly allocated to 1 of 4 dietary treatments based on corn and soybean meal and containing 0, 3, 6, and 9% of alfalfa meal for 8 wks. Each treatment consisted of 4 replicates of 16 ducks each. Briefly, birds were raised in separate compartments, and each compartment consisted of three parts: indoor floor house, adjacent open area and a connecting water area. The results showed: i) Growing ducks fed alfalfa meal diet were not significantly different in average daily gain, feed intake and gain-to-feed ratio from those fed no alfalfa diet (p>0.05). ii) Alfalfa meal increased the ratio crop, gizzard to live weight, caecum to live weight, the caecum index of growing ducks (p<0.05). iii) Villus height in duodenum and jejunum of growing ducks increased significantly with the increase of alfalfa meal levels (p<0.05). Crypt depth in duodenum and jejunum of growing ducks decreased significantly with the increase of alfalfa meal levels (p<0.05). This experiment showed that feeding of alfalfa meal to growing layer ducks could improve gastrointestinal tract growth and small intestinal morphology without effect on performance. This experiment provides evidence that alfalfa meal is a very valuable feedstuff for growing layer ducks.

Effects of alfalfa meal on carcase quality and fat metabolism of Muscovy ducks.

1. The effects of alfalfa meal on carcase quality and fat metabolism of Muscovy duck were evaluated. The objective of this research was to establish whether alfalfa meal can reduce fat content and improve carcase quality of Muscovy duck. Animal products with a high fat content present a risk factor for many diseases. Reducing fat content in poultry products is an important goal for the poultry industry. 2. A total of 240 14-d-old white Muscovy ducks were selected and randomly allocated to 1 of 4 dietary treatments containing 0, 3, 6, and 9% of alfalfa meal for 5 weeks. Growth performances were recorded and carcase characteristics and lipid parameters were analysed. 3. Results showed that 3, 6, and 9% alfalfa meal in diet had no significant effects on growth performance of Muscovy ducks from 14 to 49 d of age. Ducks given 3, 6, and 9% alfalfa meal had significantly higher dressing percentage and lower abdominal fat percentage compared with those given no alfalfa meal. Ducks given 9% alfalfa meal had higher breast meat percentage compared with those given no alfalfa meal. The concentrations of triglyceride, total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and free fatty acid in serum of ducks fed on alfalfa meal decreased. Alfalfa meal in the diet decreased abdominal fat percentage and improved carcase traits of Muscovy duck. 4. The study showed that dietary alfalfa meal decreased abdominal fat percentage and improved carcase traits, without an adverse effect on performance.

Rarefied-gas heat transfer in micro- and nanoscale Couette flows.

The physics of the heat conduction and viscous dissipation in rarefied gases is analyzed and discussed. A heat transfer model valid for arbitrary Knudsen numbers, defined as the ratio of the molecular mean free path to the characteristic length of channels, is derived by treating the heat transfer behavior in the slip and transition regimes as an intermediate function of continuum heat transfer model and free molecular heat transfer model. Comparison studies reveal that this model not only shows good agreement with the numerical results based on the direct simulation Monte Carlo method, but also has some unique features that can overcome the deficiencies existing in the previous models. Therefore, this model is capable to study the heat transport phenomena in very dilute gas Couette flows through micro/nanochannels more accurately.

Islet autoantibodies are associated with HLA-DQ genotypes in Han Chinese patients with type 1 diabetes and their relatives.

The objective of this study was to explore the relationship between islet autoantibodies of glutamic acid decarboxylase (GADA), islet antigen-2A (IA-2A), insulin autoantibody (IAA), and human leukocyte antigen (HLA)-DQ genotypes in type 1 diabetes (T1D) patients and their first-degree relatives (FDRs). Cross-sectional and case-control study. Four hundred and ninety-five T1D patients, 419 FDRs, and 376 control subjects in Han Chinese populations were recruited and tested for GADA and IA-2A, while 71 cases, all FDRs and 300 controls were tested for IAA. The 338 T1D patients (including 187 antibody-positive and 151 antibody-negative patients), 173 FDRs and 278 controls were genotyped for HLA-DQ with polymerase chain reaction sequencing-based method. Compared with the control, the frequency of DQA1*03-DQB1*0303, DQA1*05-DQB1*0201, and DQA1*03-DQB1*0401 haplotypes was higher (P < 0.05-0.01) but DQA1*0102-DQB1*0602 haplotype was lower (P < 0.01) in T1D patients. DQA1*03 allele was less in the FDRs than in their probands (P < 0.05). GADA was more prevalent in T1D patients carrying DQA1*05-DQB1*0201 or DQA1*03-DQB1*0401 haplotype (55.8% vs 41.0%, 65.5% vs 40.3%, P < 0.05-0.01), whereas IA-2A presented more in the patients carrying DQA1*03-DQB1*0303 haplotype (27.0% vs 7.9%, P < 0.05-0.01), both GADA and IA-2A showed frequently in the patients with DQA1*03-DQB1*0303/DQA1*05-DQB1*0201 haplotypes (34.5% vs 9.7%, P < 0.01). GADA positivity was lower in the patients with DQA1*0102-DQB1*0602 haplotype (16.7% vs 45.9%, P < 0.05). The frequency of IAA was not different between patients with and without susceptible DQ haplotypes (P > 0.05). GADA, IA-2A or IAA presented frequently in FDRs with DQA1*03-DQB1*0303 haplotype. The findings in the study indicate that some of specific HLA-DQA1/-DQB1 genotypes and haplotypes not only confer susceptibility to T1D but also are associated with the presence of the islet autoantibodies in the Han Chinese population.

[Clinical and experimental study on effect of shuanghuang shengbai granule on myelosuppression induced by chemotherapy and ultrastructure observation of bone marrow in mice].

OBJECTIVE: To observe the leukocyte increasing effects of Shaunghuang Shengbai Granule (SHSBG) in tumor patients treated by chemotherapy (CT) and its function on bone marrow hematopoietic microenvironment in mice. METHODS: Patients of non-small-cell lung cancer and breast, gastric or intestinal cancer, who were retreated with CT, were enrolled and divided into 4 groups randomly. The 28 cases in the treated group 1 received SHSBG and CT simultaneously. The 27 cases in the treated group 2 also received firstly CT, and SHSBG started when WBC count lowered to less than 4 x 10(9)/L after CT. The control group 1 and 2 (n = 33 and n = 24) was treated by the method similar to that applied to the treated group 1 and 2 respectively but with Rubidate instead of SHSBG. Experimental study of observing bone marrow ultrastructure in mice was also conducted with electron microscopy. RESULTS: The total leukocyte increasing effective rate occurred in the treated group 1 was 75.00%, that in the treated group 2 was 88.89%, in the control group 1 was 54.55% and in the control group 2 was 58.33%. There was significant difference between the treated groups and the control groups (P < 0.01). Experimental study showed that SHSBG has good bone marrow hematopoietic microenvironmental protecting and improving effect in mice. CONCLUSION: SHSBG has obvious protecting and treating effect on CT caused bone marrow suppression in tumor patients.

[Effects of differentiation status on apoptosis of human leukemia HL60 cells].

The effects of differentiation of human leukemia HL60 cells on harringtonine(Har) and camptothecin(Cam) induced apoptosis(in these cells) were studied. When treated with phorbol 12-myriate, 13-acetate 16 nmol.L-1 for 24 h, the HL60 cells differentiated into monocyte/macrophage cells and were arrested at G1 phase. The differentiated cells were shown to be resistant to the Har and Cam induced apoptosis, but showed no change of expression of c-myc gene. HL60 cells incubated in 1.4% dimethyl sulfoxide for 48 h differentiated into granulocyte cells and were also gene arrested at G1 phase. The differentiated cells became resistant to the apoptosis induced by Cam, but not that by Har, and expression of c-myc decreased drastically in the differentiated cells. The results indicate that the differentiated status of human leukemia HL60 cells apparently affected the apoptosis induced by harringtonine and camptothecin, but it was irrelevant to the change of the expression of c-myc gene.

Characteristics of harringtonine-resistant human leukemia HL60 cell.

AIM: To study the mechanisms of the resistance to harringtonine (Har) in the HL60 cells. METHODS: Growth inhibition, karyotype analysis, flow cytometry, Western blotting and polymerase chain reaction. RESULTS: The Har-resistant HL60 cell line, named HR20, showed cross resistance to homoharringtonine, doxorubicin, daunorubicin, vincristine, and colchicine. The growth doubling time and the cell numbers in G1 phase were increased. The accumulation of cellular daunorubicin in the resistant cells was obviously reduced, but distinctly increased by tetrandrine and verapamil. The numbers of telocentromeric chromosome increased and the chromosomal aberration more occured in the resistant cells. The resistant cells overexpressed multidrug resistant mdr-1 gene and P-glycoprotein 150 kDa. CONCLUSION: The Har-resistant HL60 cell strain belonged to a multidrug resistance strain, overexpressing mdr-1 gene and P-glycoprotein.

Correlation between expression of mdr-1 gene and oncogenes in human promyelocytic leukemic HL60 cell line and sublines.

AIM: To study the relationship between expression of oncogenes and multiple drug resistant (MDR) phenotype. METHODS: The drug resistant level of HL60 cell line and its sublines were determined with flow cytometry. RNA Dot blot hybridization was used to identify the expression of oncogenes and mdr-1 gene. RESULTS: The expression of mdr-1 gene was in the opposite relation with c-myc expression, but in the positive relation with c-H-ras gene expression in the multiple drug resistant cell lines. In non-MDR cell line HL60/RA, the expression levels of mdr-1, c-myc, and c-H-ras were the same as HL60 parental cells. CONCLUSION: Multiple drug resistance is related to not only mdr-1 expression, but also some oncogenes expression level.

[Induction of expression of MDR 1 gene by retinoic acid and DMSO and effects on rhodamine-123 efflux in HL-60 cell lines and resistant sublines].

Using dot blot hybridization and flowcytometry, the effects of differentiation inducers retinoic acid (RA) and dimethyl sulfoxide (DMSO) on the resistant level of HL-60 cells and its resistant subline cells were studied. When the cells were treated with RA 1 mumol.L-1 for 24 h, the expression of MDR 1 mRNA evidently increased in both HL-60 and its multidrug resistant subline cells. The efflux of Rho-123 in the multidrug resistant subline cells was slightly decreased. But, when the cells were treated with 2% DMSO for 24 h the efflux of Rho-123 increased obviously. The results suggest that RA can induce the expression of MDR1 gene but perhaps inhibit the function of pump glycoprotein 170 (Pgp-170) through phosphorylation/dephosphorylation pathway. However, DMSO could induce the expression of full function of Pgp.

Inefficient complementation activity of poliovirus 2C and 3D proteins for rescue of lethal mutations.

Poliovirus (PV) 2C protein is a nonstructural polypeptide involved in viral RNA replication, whose biochemical activity(ies) in this process has not been defined. By using site-directed mutagenesis, it was shown previously that disruption of nucleotide-binding motifs present in this protein abolished viral RNA synthesis (C. Mirzayan and E. Wimmer, Virology 189:547-555, 1992; N. L. Teterina, K. M. Kean, E. Gorbalenya, V. I. Agol, and M. Girard, J. Gen. Virol. 73:1977-1986, 1992). We have tested whether PV 2C or 2BC protein provided in trans could rescue the replication of these mutated genomes. Rescuing proteins were provided either by cotransfection with helper chimeric PV-coxsackievirus genomes or by expression in cells with a vaccinia virus-T7 RNA polymerase transient-expression system. We report here that replication of mutated RNAs genomes was poorly supported in trans both by helper genomes and by expressed 2C or 2BC proteins. Similarly, very inefficient complementation was observed for two mutated genomes with lethal lesions in 3D polymerase coding sequence. Our results indicate that poliovirus RNA replication shows marked preference for proteins contributed in cis.

The molecular specificity of linear B-epitopes in the E7 open reading frame protein of human papillomavirus 16 defined by monoclonal antibodies.

Human papillomavirus (HPV) 16 is highly associated with premalignant and malignant anogenital epithelial lesions. The transforming function resides within the viral E7 open reading frame protein. We have defined three immunodominant linear B-epitopes in the E7 protein. In the present study, we determine the contribution of individual amino acid residues to antibody binding of these three epitopes using replacement set analysis. In this approach, each epitope residue is substituted in turn by each of the other 19 genetically encoded amino acids to produce analogues which are tested for specific monoclonal antibody binding. We demonstrate the specificity of the monoclonal antibodies for epitopes of HPV 16 E7 in binding studies using synthetic epitope analogues of other HPV genotypes. Comparison between HPV 16 and other HPV genotypes suggests that variability in amino acid composition at the E7 epitopic sites does not appear to be host-antibody driven.

Prostaglandin E and F2 alpha levels in plasma and amniotic fluid during mid-trimester abortion induced by trichosanthin.

This paper gives a brief account concerning the estimation of PGE and PGF2 alpha concentrations in both plasma and amniotic fluid by radioimmunoassay in mid-trimester abortion induced by Trichosanthin. The significant change in amniotic fluids as compared with that in plasma is brought out for discussion as an aid to the study of mechanism of abortion by Trichosanthin.

PIP: Trichosanthin, an abortifacient plant protein isolated from Radix Trichosanthes, has a success rate of approximately 98%. This paper examines changes in prostaglandin (PG) E and F2alpha levels in both plasma and amniotic fluid by radioimmunoassay in midtrimester abortion induced by Trichosanthin. Trichosanthin was given by transabdominal amniotic injection (average dosage, 8-11 mg) in 8 women (7 primigravidae and 1 secundigravida) of 17-24 weeks gestation. Venous blood and amniotic fluid samples were collected both before and after drug administration. PGE and F2alpha in plasma and amniotic fluid were measured by radioimmunoassay based upon a method described by the Pekin Institute of Zoology. Injection-abortion time ranged from 72-168 hours with a mean of 100 hours. No significant change was observed between concentrations of PGE and PGF2alpha in the plasma before and after drug administration, probably due to the fact that the 2 PGs were released in pulsatile fashion instead of continuous, and because PGs have short half-life in the circulating blood. In contrast, both PGE and PGF2alpha levels in the amniotic fluid were markedly increased after Trichosanthin administration, the increments amounting to 12.8 and 23.8 times the preinjection value respectively (p0.001). In midtrimester abortion, Trichosanthin exerts a selective action on the syncytiotrophoblasts as demonstrated by their degenerative and necrotic changes and simultaneous deciduitis. These injuries are followed by impairment of the endocrine functions of the placenta, a disintegration of lysosomes inside the decidual cells, and a decreased stability of the lysosomal membrane, an increase of synthesis of PGE and PGF2alpha both in the fetal membrane and decidua, and finally, complete abortion.