Intestinal Translocation of Live Porphyromonas gingivalis Drives Insulin Resistance

Periodontitis has been emphasized as a risk factor of insulin resistance-related systemic diseases. Accumulating evidence has suggested a possible "oral-gut axis" linking oral infection and extraoral diseases, but it remains unclear whether periodontal pathogens can survive the barriers of the digestive tract and how they play their pathogenic roles. The present study established a periodontitis mouse model through oral ligature plus Porphyromonas gingivalis inoculation and demonstrated that periodontitis aggravated diet-induced obesity and insulin resistance, while also causing P. gingivalis enrichment in the intestine. Metabolic labeling strategy validated that P. gingivalis could translocate to the gastrointestinal tract in a viable state. Oral administration of living P. gingivalis elicited insulin resistance, while administration of pasteurized P. gingivalis had no such effect. Combination analysis of metagenome sequencing and nontargeted metabolomics suggested that the tryptophan metabolism pathway, specifically indole and its derivatives, was involved in the pathogenesis of insulin resistance caused by oral administration of living P. gingivalis. Moreover, liquid chromatography-high-resolution mass spectrometry analysis confirmed that the aryl hydrocarbon receptor (AhR) ligands, mainly indole acetic acid, tryptamine, and indole-3-aldehyde, were reduced in diet-induced obese mice with periodontitis, leading to inactivation of AhR signaling. Supplementation with Ficz (6-formylindolo (3,2-b) carbazole), an AhR agonist, alleviated periodontitis-associated insulin resistance, in which the restoration of gut barrier function might play an important role. Collectively, these findings reveal that the oral-gut translocation of viable P. gingivalis works as a fuel linking periodontitis and insulin resistance, in which reduction of AhR ligands and inactivation of AhR signaling are involved. This study provides novel insight into the role of the oral-gut axis in the pathogenesis of periodontitis-associated comorbidities.

Bioinformatics-based design of a fusion vaccine with CTLA-4 variable region to combat Brucella

Brucellosis has become a global zoonotic disease, seriously endangering the health of people all over the world. Vaccination is an effective strategy for protection against Brucella infection in livestock in developed countries. However, current vaccines are pathogenic to humans and pregnant animals, which limits their use. Therefore, it is very important to improve the safety and immune protection of Brucella vaccine. In this study, different bioinformatics approaches were carried out to predict the physicochemical properties, T/B epitope, and tertiary structure of Omp2b and Omp31. Then, these two proteins were sequentially linked, and the Cytotoxic T lymphocyte associated antigen-4 (CTLA-4) variable region was fused to the N-terminal of the epitope sequence. In addition, molecular docking was performed to show that the structure of the fusion protein vaccine had strong affinity with B7 (B7-1, B7-2). This study showed that the designed vaccine containing CTLA-4 had high potency against Brucella, which could provide a reference for the future development of efficient brucellosis vaccines.

Comprehensive Analysis of Long Non-coding RNA and mRNA Transcriptomes Related to Hypoxia Adaptation in Tibetan Sheep

Tibetan sheep have lived on the Qinghai-Tibet Plateau for a long time, and after long-term natural selection, they have shown stable genetic adaptability to high-altitude environments. However, little is known about the molecular mechanisms of the long non-coding (lnc)RNAs involved in the adaptation of Tibetan sheep to hypoxia. Here, we collected lung tissues from high-altitude Tibetan sheep and low-altitude Hu sheep for RNA sequencing to study the regulatory mechanisms of the lncRNAs and mRNAs in the adaptation of Tibetan sheep to hypoxia. We identified 254 differentially expressed lncRNAs and 1,502 differentially expressed mRNAs. We found 20 pairs of cis-regulatory relationships between 15 differentially expressed lncRNAs and 14 protein-coding genes and two pairs of trans-regulatory relationships between two differentially expressed lncRNAs and two protein-coding genes. These differentially expressed mRNAs and lncRNA target genes were mainly enriched in pathways related to lipid metabolism and immune function. Interaction network analysis showed that 17 differentially expressed lncRNAs and 15 differentially expressed mRNAs had an interactive relationship. Additionally, we used six differentially expressed lncRNAs and mRNAs to verify the accuracy of the sequencing data via qRT-PCR. Our results provide a comprehensive overview of the expression patterns of the lncRNAs and mRNAs involved in the adaptation of Tibetan sheep to hypoxia, laying a foundation for further analysis of the adaptations of plateau animals.

The Transcriptional Cell Atlas of Testis Development in Sheep at Pre-Sexual Maturity

Sheep testes undergo a dramatic rate of development with structural changes during pre-sexual maturity, including the proliferation and maturation of somatic niche cells and the initiation of spermatogenesis. To explore this complex process, 12,843 testicular cells from three males at pre-sexual maturity (three-month-old) were sequenced using the 10× Genomics Chromium^TM single-cell RNA-seq (scRNA-seq) technology. Nine testicular somatic cell types (Sertoli cells, myoid cells, monocytes, macrophages, Leydig cells, dendritic cells, endothelial cells, smooth muscle cells, and leukocytes) and an unknown cell cluster were observed. In particular, five male germ cell types (including two types of undifferentiated spermatogonia (A_pale and A_dark), primary spermatocytes, secondary spermatocytes, and sperm cells) were identified. Interestingly, A_pale and A_dark were found to be two distinct states of undifferentiated spermatogonia. Further analysis identified specific marker genes, including UCHL1, DDX4, SOHLH1, KITLG, and PCNA, in the germ cells at different states of differentiation. The study revealed significant changes in germline stem cells at pre-sexual maturation, paving the way to explore the candidate factors and pathways for the regulation of germ and somatic cells, and to provide us with opportunities for the establishment of livestock stem cell breeding programs.

A generalized l 2,p-norm regression based feature selection algorithm

Feature selection is an important data dimension reduction method, and it has been used widely in applications involving high-dimensional data such as genetic data analysis and image processing. In order to achieve robust feature selection, the latest works apply the l 2 , 1 or l 2 , p -norm of matrix to the loss function and regularization terms in regression, and have achieved encouraging results. However, these existing works rigidly set the matrix norms used in the loss function and the regularization terms to the same l 2 , 1 or l 2 , p -norm, which limit their applications. In addition, the algorithms for solutions they present either have high computational complexity and are not suitable for large data sets, or cannot provide satisfying performance due to the approximate calculation. To address these problems, we present a generalized l 2 , p -norm regression based feature selection ( l 2 , p -RFS) method based on a new optimization criterion. The criterion extends the optimization criterion of ( l 2 , p -RFS) when the loss function and the regularization terms in regression use different matrix norms. We cast the new optimization criterion in a regression framework without regularization. In this framework, the new optimization criterion can be solved using an iterative re-weighted least squares (IRLS) procedure in which the least squares problem can be solved efficiently by using the least square QR decomposition (LSQR) algorithm. We have conducted extensive experiments to evaluate the proposed algorithm on various well-known data sets of both gene expression and image data sets, and compare it with other related feature selection methods.

[CFTR gene variations and phenotypes in seven children]

Objective: To analyze the cystic fibrosis transmembrane conductance regulator (CFTR) gene variations and phenotypes in 7 Chinese children. Methods: In this retrospective study, the data of 7 children with CFTR gene variations admitted to Children's Hospital of Chongqing Medical University from December 2013 to October 2020 were extracted. The general information, clinical manifestations, gene variations, diagnosis and treatment were summarized. Results: Among the 7 children, 2 were males and 5 were females, aged 5.2(0.5-11.3) years. Main clinical manifestations included malnutrition (5 cases), recurrent respiratory infection (4 cases), bronchiectasis (3 cases), steatorrhea (3 cases), vomiting in infancy (2 cases), liver cirrhosis (2 cases), meconium ileus (1 case), metabolic alkalosis and hypochloremia (1 case). A total of 15 variations were found by whole exon sequencing and Sanger sequencing, among which 3 were newly discovered, and 7 were missense mutations. Four children were diagnosed as CF, and the other 3 were diagnosed as CFTR related disease (CFTR-RD). Compared with CF patients, the pancreatic insufficiency and typical CF lung disease were relatively mild in CFTR-RD patients. After treatment, 6 children were clinically improved, while the rest one withdrew treatment due to critical pulmonary infection and disturbance of water-electrolyte metabolism. Conclusions: The loci and phenotypes of CFTR gene variants vary hugely and the pathogenicity of some variations are not clear. Whole exon sequencing can facilitate the identification of CF-and CFTR-RD-causing variaions. For the cases not compatible with CF, CFTR-RD should be considered and evaluated by timely gene detection, so as to carry out appropriate long term management.

Quantitative proteomic analysis identified differentially expressed proteins with tail/rump fat deposition in Chinese thin- and fat-tailed lambs

Tail adipose as one of the important functional tissues can enhance hazardous environments tolerance for sheep. The objective of this study was to gain insight into the underlying development mechanisms of this trait. A quantitative analysis of protein abundance in ovine tail/rump adipose tissue was performed between Chinese local fat- (Kazakh, Hu and Lanzhou) and thin-tailed (Alpine Merino, Tibetan) sheep in the present study by using lable-free approach. Results showed that 3400 proteins were identified in the five breeds, and 804 were differentially expressed proteins, including 638 up regulated proteins and 83 down regulated proteins in the tail adipose tissues between fat- and thin-tailed sheep, and 8 clusters were distinguished for all the DEPs’ expression patterns. The differentially expressed proteins are mainly associated with metabolism pathways and peroxisome proliferator activated receptor signaling pathway. Furthermore, the proteomics results were validated by quantitative real-time PCR and Western Blot. Our research has also suggested that the up-regulated proteins ACSL1, HSD17β4, FABP4 in the tail adipose tissue might contribute to tail fat deposition by facilitating the proliferation of adipocytes and fat accumulation in tail/rump of sheep. Particularly, FABP4 highly expressed in the fat-tail will play an important role for tail fat deposition. Our study might provide a novel view to understanding fat accumulation in special parts of the body in sheep and other animals.

A global analysis of CNVs in Chinese indigenous fine-wool sheep populations using whole-genome resequencing

Background

Copy number variation (CNV) is an important source of genetic variation that has a significant influence on phenotypic diversity, economically important traits and the evolution of livestock species. In this study, the genome-wide CNV distribution characteristics of 32 fine-wool sheep from three breeds were analyzed using resequencing.

Results

A total of 1,747,604 CNVs were detected in this study, and 7228 CNV regions (CNVR) were obtained after merging overlapping CNVs; these regions accounted for 2.17% of the sheep reference genome. The average length of the CNVRs was 4307.17 bp. “Deletion” events took place more frequently than “duplication” or “both” events. The CNVRs obtained overlapped with previously reported sheep CNVRs to variable extents (4.39–55.46%). Functional enrichment analysis showed that the CNVR-harboring genes were mainly involved in sensory perception systems, nutrient metabolism processes, and growth and development processes. Furthermore, 1855 of the CNVRs were associated with 166 quantitative trait loci (QTL), including milk QTLs, carcass QTLs, and health-related QTLs, among others. In addition, the 32 fine-wool sheep were divided into horned and polled groups to analyze for the selective sweep of CNVRs, and it was found that the relaxin family peptide receptor 2 (RXFP2) gene was strongly influenced by selection.

Conclusions

In summary, we constructed a genomic CNV map for Chinese indigenous fine-wool sheep using resequencing, thereby providing a valuable genetic variation resource for sheep genome research, which will contribute to the study of complex traits in sheep.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07387-7.

Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry and Rapid Evaporative Ionization Mass Spectrometry Were Used to Develop a Lamb Authentication Method: A Preliminary Study

A untargeted metabolomics approach was proposed in this study based on ultra-high performance liquid chromatography quadrupole time-of-flight (UHPLC-QTOF) and rapid evaporative ionization mass spectrometry (REIMS) to discriminate lamb and mutton meat and investigate their subtle metabolic differences, considering the higher popularity of lamb meat than mutton in the market. Multivariate statistical analysis was performed for data processing in order to distinguish between the two sample types. A total of 42 potential metabolites (20 in positive and 22 in negative ion mode) were defined for UHPLC-QTOF analysis, which provided references for discriminating the two kinds of meat. Furthermore, three potential markers were tentatively identified using LC/MS data against chemical databases. In addition, 14 potential metabolites were putatively identified in negative ion mode using the LipidMaps database. Meanwhile, the data-driven soft independent modeling of class analogy (DD-SIMCA) model was established, which could rapidly differentiate non-pretreated lamb meat and mutton with 92% specificity, rendering REIMS a promising technique for meat identification.

Exogenous 6-benzyladenine application affects root morphology by altering hormone status and gene expression of developing lateral roots in Malus hupehensis

Malus hupehensis is an extensively used apple rootstock in China. In the current study, M. hupehensis seedlings were treated with exogenous 2.2 µm 6-benzyladenine (6-BA) so as to investigate the mechanism by which 6-BA affects lateral root development. The results indicate that 6-BA treatment promotes elongation and thickening of both root and shoot in M. hupehensis, but reduces the number of lateral roots, as well as reducing the auxin level after 6-BA treatment. Moreover, MhAHK4, MhRR1 and MhRR2 were also significantly up-regulated in response to 6-BA treatment. Expression levels of auxin synthesis- and transport-related genes, such as MhYUCCA6, MhYUCCA10, MhPIN1 and MhPIN2, were down-regulated, which corresponds with lower auxin levels in the 6-BA-treated seedlings. A negative regulator of auxin, MhIAA3, was induced by 6-BA treatment, leading to reduced expression of MhARF7 and MhARF19 in 6-BA-treated seedlings. As a result, expression of MhWOX11, MhWOX5, MhLBD16 and MhLBD29 was blocked, which in turn inhibited lateral root initiation. In addition, a lower auxin level decreased expression of MhRR7 and MhRR15, which repressed expression of key transcription factors associated with root development, thus inhibiting lateral root development. In contrast, 6-BA treatment promoted secondary growth (thickening) of the root by inducing expression of MhCYCD3;1 and MhCYCD3;2. Collectively, the changes in hormone levels and gene expression resulted in a reduced number of lateral roots and thicker roots in 6-BA-treated plants.

Genetic signatures of high-altitude adaptation and geographic distribution in Tibetan sheep

Most sheep breeding programs designed for the tropics and sub-tropics have to take into account the impacts of environmental adaptive traits. However, the genetic mechanism regulating the multiple biological processes driving adaptive responses remains unclear. In this study, we applied a selective sweep analysis by combing 1% top values of F_st and ZHp on both altitude and geographic subpopulations (APS) in 636 indigenous Tibetan sheep breeds. Results show that 37 genes were identified within overlapped genomic regions regarding F_st significantly associated with APS. Out of the 37 genes, we found that 8, 3 and 6 genes at chromosomes (chr.) 13, 23 and 27, respectively, were identified in the genomic regions with 1% top values of ZHp. We further analyzed the INDEL variation of 6 genes at chr.27 (X chromosome) in APS together with corresponding orthologs of 6 genes in Capra, Pantholops, and Bos Taurus. We found that an INDEL was located within 5′UTR region of HAG1 gene. This INDEL of HAG1 was strongly associated with the variation of APS, which was further confirmed by qPCR. Sheep breeds carrying “C-INDEL” of HAG1 have significantly greater body weight, shear amount, corpuscular hemoglobin and globulin levels, but lower body height, than those carrying “CA-INDEL” of HAG1. We concluded that “C-INDEL” variation of HAG1 gene confers better hypoxia tolerance in the highlands of Tibetan and explains well geographic distributions in this population. These results contribute to our understanding of adaptive responses to altitude and geographic adaptation in Tibetan sheep populations and will help to guide future conservation programs for Tibetan sheep native to Qinghai-Tibetan Plateau.

Analysis of dynamic and widespread lncRNA and miRNA expression in fetal sheep skeletal muscle

The sheep is an economically important animal, and there is currently a major focus on improving its meat quality through breeding. There are variations in the growth regulation mechanisms of different sheep breeds, making fundamental research on skeletal muscle growth essential in understanding the regulation of (thus far) unknown genes. Skeletal muscle development is a complex biological process regulated by numerous genes and non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). In this study, we used deep sequencing data from sheep longissimus dorsi (LD) muscles sampled at day 60, 90, and 120 of gestation, as well as at day 0 and 360 following birth, to identify and examine the lncRNA and miRNA temporal expression profiles that regulate sheep skeletal myogenesis. We stained LD muscles using histological sections to analyse the area and circumference of muscle fibers from the embryonic to postnatal development stages. Our results showed that embryonic skeletal muscle growth can be characterized by time. We obtained a total of 694 different lncRNAs and compared the differential expression between the E60 vs. E90, E90 vs. E120, E120 vs. D0, and D0 vs. D360 lncRNA and gene samples. Of the total 701 known sheep miRNAs we detected, the following showed a wide range of expression during the embryonic stage: miR-2387, miR-105, miR-767, miR-432, and miR-433. We propose that the detected lncRNA expression was time-specific during the gestational and postnatal stages. GO and KEGG analyses of the genes targeted by different miRNAs and lncRNAs revealed that these significantly enriched processes and pathways were consistent with skeletal muscle development over time across all sampled stages. We found four visual lncRNA–gene regulatory networks that can be used to explore the function of lncRNAs in sheep and may be valuable in helping improve muscle growth. This study also describes the function of several lncRNAs that interact with miRNAs to regulate myogenic differentiation.

Comparative proteomics reveals genetic mechanisms underlying secondary hair follicle development in fine wool sheep during the fetal stage

The aim of this study was to investigate the genetic mechanisms underlying wool production by characterizing the skin protein profile and determining the proteomic changes that occur as a consequence of development in wool-producing sheep using a label-free proteomics approach. Samples were collected at four stages during gestation (87, 96, 102, and 138 days), and every two consecutive stages were statistically compared (87 versus 96, 96 versus 102, and 102 versus 138 days). We identified 227 specific proteins in the sheep proteome that were present in all four stages, and 123 differentially abundant proteins (DAPs). We also observed that the microstructure of the secondary follicles changed significantly during the development of the fetal skin hair follicle. The screened DAPs were strictly related to metabolic and skin development pathways, and were associated with pathways such as the glycolysis/gluconeogenesis. These analyses indicated that the wool production of fine wool sheep is regulated via a variety of pathways. These findings provide an important resource that can be used in future studies of the genetic mechanisms underlying wool traits in fine wool sheep, and the identified DAPs should be further investigated as candidate markers for predicting wool traits in sheep. SIGNIFICANCE: Wool quality (fiber diameter, length, etc.) is an important economic trait of fine wool sheep that is determined by secondary follicle differentiation and re-differentiation. Secondary follicles of fine wool sheep developed from a bud (87 days), and underwent differentiation (96 days) and rapid growth (102 days) until maturity (138 days) during gestation. Comparative analysis based on differential proteomics of these four periods could provide a better understanding of the wool growth mechanism of fine wool sheep and offer novel strategies for improving fine wool quality by breeding.

Genome-Wide Association Study of Body Weight Traits in Chinese Fine-Wool Sheep

Body weight is an important economic trait for sheep and it is vital for their successful production and breeding. Therefore, identifying the genomic regions and biological pathways that contribute to understanding variability in body weight traits is significant for selection purposes. In this study, the genome-wide associations of birth, weaning, yearling, and adult weights of 460 fine-wool sheep were determined using resequencing technology. The results showed that 113 single nucleotide polymorphisms (SNPs) reached the genome-wide significance levels for the four body weight traits and 30 genes were annotated effectively, including AADACL3, VGF, NPC1, and SERPINA12. The genes annotated by these SNPs significantly enriched 78 gene ontology terms and 25 signaling pathways, and were found to mainly participate in skeletal muscle development and lipid metabolism. These genes can be used as candidate genes for body weight in sheep, and provide useful information for the production and genomic selection of Chinese fine-wool sheep.

Two linked TBXT (brachyury) gene polymorphisms are associated with the tailless phenotype in fat-rumped sheep

T‐box transcription factor T (TBXT), encoding the brachyury protein, is an embryonic nuclear transcription factor involved in mesoderm formation and differentiation. Previous studies indicate that TBXT mutations are responsible for the tailless or short‐tailed phenotype of many vertebrates. To verify whether the tailless phenotype in fat‐rumped sheep is associated with TBXT mutations, exon 2 of the TBXT gene for 301 individuals belonging to 13 Chinese and Iranian sheep breeds was directly sequenced. Meanwhile, 380 samples were used to detect the genotypes of the candidate variations by mapping to their reads databases in the Sequence Read Archive repository of GenBank. The results showed that one missense mutation, c.334G>T (GGG>TGG) with a completely linked synonymous variant c.333G>C (CCG>CCC) was found to be associated with the ‘tailless’ characteristic in typical fat‐rumped sheep breeds. The c.334G>T transversion led to the conversion of glycine to tryptophan at the 112th amino acid in the T‐box domain of the brachyury protein. In addition, crossbreeding experiments for long‐tailed and tailless sheep showed that CT/CT allele of nucleotides (nt) 333 and 334, a recessive mutation, would cause sheep tails to be shorter, suggesting that these two linked variants at nucleotides 333 and 334 in TBXT are probably causative mutations responsible for the tailless phenotype in sheep.

Vitamin A maintains the airway epithelium in a murine model of asthma by suppressing glucocorticoid-induced leucine zipper

BACKGROUND

The effects of glucocorticoids (GCs) on the repair of the airway epithelium in asthma are controversial, and we previously reported that the GC dexamethasone (Dex) inhibits the repair of human airway epithelial cells and that this process is mediated by glucocorticoid-induced leucine zipper (GILZ) through MAPK-ERK signaling in vitro. Vitamin A (VA) is involved in the regulation of the MAPK-ERK pathway but has not been widely supplied during asthma treatment. It is unclear whether VA attenuates the negative regulation of GILZ on the MAPK-ERK pathway and maintains airway epithelium integrity during asthma treatment.

METHODS

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) and subsequently treated with Dex, VA or intranasal inhalation of adenovirus sh-GILZ vectors. Indexes of airway epithelium integrity, including pathological alterations, pulmonary EGFR expression and airway hyperresponsiveness (AHR), were then measured. The expression of GILZ and key components of activated MAPK-ERK signals (p-Raf-1, p-MEK, and p-Erk1/2) were also detected.

RESULTS

Dex failed to relieve OVA-induced asthma airway epithelium injury, as assessed through H&E staining, EGFR expression and AHR. Moreover, in the OVA-challenged mice treated with Dex, GLIZ expression was increased, whereas the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were significantly decreased. Further study indicated that GILZ expression was decreased and that the ratios of p-Raf-1/Raf-1, p-MEK/MEK and p-Erk1/2/Erk1/2 were up-regulated in the GILZ-silenced OVA-challenged mice and VA-fed OVA-challenged mice, independent of Dex treatment. The airway epithelium integrity of the OVA-challenged mice was maintained by treatment with both VA and Dex.

CONCLUSIONS

Vitamin A maintained the Dex-treated asthma airway epithelium via the down-regulation of GILZ expression and the activation MAPK-ERK signaling, and these effects might contribute to improving the effects of GC therapeutics on asthma.

Apical stress distribution under vertical compaction of gutta-percha and occlusal loads in canals with varying apical sizes: a three-dimensional finite element analysis

AIM

To investigate and compare the effects of two apical canal instrumentation protocols on apical stress distribution at the root apex under vertical compaction of gutta-percha and occlusal loads using finite element analysis.

METHODOLOGY

Three finite element analysis models of a mandibular first premolar were reconstructed: an original canal model, a size 35, .04 taper apical canal enlargement model and a Lightspeed size 60 apical canal enlargement model. A 15 N compaction force was applied vertically to the gutta-percha 5 mm from the apex. A 175 N occlusal load in two directions (vertical and 45° to the longitudinal axis of the tooth) was simulated. Stresses in the apical 2 mm of the root were calculated and compared among the three models.

RESULTS

Under vertical compaction, stresses in the apical canal instrumented by Lightspeed size 60 (maximal 3.3 MPa) were higher than that of the size 35, .04 taper model (maximal 1.3 MPa). In the case of the two occlusal forces, the Lightspeed size 60 apical enlargement was associated with the greatest stress distribution in the apical region. The greatest stress and the most obvious stress difference between the models appeared at the tip of the root when occlusal and vertical compaction loads were applied.

CONCLUSIONS

Apical enlargement caused stress distribution changes in the apical region of roots. The larger apical size led to higher stress concentration at the root apex.

Evaluation of Crossbreeding of Australian Superfine Merinos with Gansu Alpine Finewool Sheep to Improve Wool Characteristics

Crossbreeding of Australian Superfine Merinos (ASMs) with Gansu Alpine Finewool (GAF) sheep and an evaluation of the potential benefits of this genetic cross has not been previously conducted. 13 ASMs were crossbred with GAF sheep over a five year period with backcrossing designed to assess heterosis. Data from 11,178 lambs sired by 189 rams were used in the study. Genotype, birth year, birth type, dam age, sex and/or management group, and record age were fitted as fixed effects and within-genotype sire fitted as a random effect. Crossbreeds of 1/2 ASM expressed the most desirable effects for improving average fiber diameter (AFD), clean fleece weight (CFW), yield, coefficient of variation of AFD (CVAFD), yearling staple length (YSL) to AFD ratio (YSL/AFD), and CFW to metabolic yearling bodyweight (YWT^0.75) ratio (CFW/YWT^0.75) but showed the least post-weaning average daily gain (powADG) and YWT. Genotype of backcrossing with 1/4 ASM obtained moderate improvements in AFD, CFW, CVAFD, and YSL/AFD but the highest YSL, WWT, and prwADG. Except for yield (-1.42%) and CFW/YWT^0.75 (-1%), heterosis estimates were generally low and positive, and ranged from 0.1% for CVAFD to 4% for powADG, which indicates the potential to improve relevant traits through exploiting heterosis to a varying extent. The ASMs sampled in this study were found to be superior to GAFs for AFD, CFW, yield, and CVAFD by 19.82%, 11.68%, 14.47%, and 6.99%, respectively, but inferior for YSL, PowADG, and YWT by 4.36%, 50.97%, and 16.93%, respectively. ASMs also appeared to be more efficient than GAFs in clean wool production (25.34%) and staple length growth (16.17%). The results of our study strongly suggest that an infusion of ASM genes via crossbreeding is an effective and appropriate approach to improve wool microns and wool production from GAF sheep, and we make recommendations to tackle the undesirable traits of YWT and YSL from ASM introduction.

Genetic Diversity and Phylogenetic Evolution of Tibetan Sheep Based on mtDNA D-Loop Sequences

The molecular and population genetic evidence of the phylogenetic status of the Tibetan sheep (Ovis aries) is not well understood, and little is known about this species' genetic diversity. This knowledge gap is partly due to the difficulty of sample collection. This is the first work to address this question. Here, the genetic diversity and phylogenetic relationship of 636 individual Tibetan sheep from fifteen populations were assessed using 642 complete sequences of the mitochondrial DNA D-loop. Samples were collected from the Qinghai-Tibetan Plateau area in China, and reference data were obtained from the six reference breed sequences available in GenBank. The length of the sequences varied considerably, between 1031 and 1259 bp. The haplotype diversity and nucleotide diversity were 0.992±0.010 and 0.019±0.001, respectively. The average number of nucleotide differences was 19.635. The mean nucleotide composition of the 350 haplotypes was 32.961% A, 29.708% T, 22.892% C, 14.439% G, 62.669% A+T, and 37.331% G+C. Phylogenetic analysis showed that all four previously defined haplogroups (A, B, C, and D) were found in the 636 individuals of the fifteen Tibetan sheep populations but that only the D haplogroup was found in Linzhou sheep. Further, the clustering analysis divided the fifteen Tibetan sheep populations into at least two clusters. The estimation of the demographic parameters from the mismatch analyses showed that haplogroups A, B, and C had at least one demographic expansion in Tibetan sheep. These results contribute to the knowledge of Tibetan sheep populations and will help inform future conservation programs about the Tibetan sheep native to the Qinghai-Tibetan Plateau.

Integrated Analysis of the Roles of Long Noncoding RNA and Coding RNA Expression in Sheep (Ovis aries) Skin during Initiation of Secondary Hair Follicle

Initiation of hair follicle (HF) is the first and most important stage of HF morphogenesis. However the precise molecular mechanism of initiation of hair follicle remains elusive. Meanwhile, in previous study, the more attentions had been paid to the function of genes, while the roles of non-coding RNAs (such as long noncoding RNA and microRNA) had not been described. Therefore, the roles of long noncoding RNA(LncRNA) and coding RNA in sheep skin during the initiation of sheep secondary HF were integrated and analyzed, by using strand-specific RNA sequencing (ssRNA-seq).A total of 192 significant differentially expressed genes were detected, including 67 up-regulated genes and 125 down-regulated genes between stage 0 and stage 1 of HF morphogenesis during HF initiation. Only Wnt2, FGF20 were just significant differentially expressed among Wnt, Shh, Notch and BMP signaling pathways. Further expression profile analysis of lncRNAs showed that 884 novel lncRNAs were discovered in sheep skin expression profiles. A total of 15 lncRNAs with significant differential expression were detected, 6 up-regulated and 9 down-regulated. Among of differentially expressed genes and LncRNA, XLOC002437 lncRNA and potential target gene COL6A6 were all significantly down-regulated in stage 1. Furthermore, by using RNAhybrid, XLOC005698 may be as a competing endogenous RNA ''sponges" oar-miR-3955-5p activity. Gene Ontology and KEGG pathway analyses indicated that the significantly enriched pathway was peroxisome proliferator-activated receptors (PPARs) pathway (corrected P-value < 0.05), indicating that PPAR pathway is likely to play significant roles during the initiation of secondary HF.Results suggest that the key differentially expressed genes and LncRNAs may be considered as potential candidate genes for further study on the molecular mechanisms of HF initiation, as well as supplying some potential values for understanding human hair disorders.

Exploring Differentially Expressed Genes and Natural Antisense Transcripts in Sheep (Ovis aries) Skin with Different Wool Fiber Diameters by Digital Gene Expression Profiling

Wool fiber diameter (WFD) is the most important economic trait of wool. However, the genes specifically controlling WFD remain elusive. In this study, the expression profiles of skin from two groups of Gansu Alpine merino sheep with different WFD (a super-fine wool group [FD = 18.0 ± 0.5 μm, n=3] and a fine wool group [FD=23.0 ± 0.5 μm, n=3]) were analyzed using next-generation sequencing-based digital gene expression profiling. A total of 40 significant differentially expressed genes (DEGs) were detected, including 9 up-regulated genes and 31 down-regulated genes. Further expression profile analysis of natural antisense transcripts (NATs) showed that more than 30% of the genes presented in sheep skin expression profiles had NATs. A total of 7 NATs with significant differential expression were detected, and all were down-regulated. Among of 40 DEGs, 3 DEGs (AQP8, Bos d2, and SPRR) had significant NATs which were all significantly down-regulated in the super-fine wool group. In total of DEGs and NATs were summarized as 3 main GO categories and 38 subcategories. Among the molecular functions, cellular components and biological processes categories, binding, cell part and metabolic process were the most dominant subcategories, respectively. However, no significant enrichment of GO terms was found (corrected P-value >0.05). The pathways that were significantly enriched with significant DEGs and NATs were mainly the lipoic acid metabolism, bile secretion, salivary secretion and ribosome and phenylalanine metabolism pathways (P < 0.05). The results indicated that expression of NATs and gene transcripts were correlated, suggesting a role in gene regulation. The discovery of these DEGs and NATs could facilitate enhanced selection for super-fine wool sheep through gene-assisted selection or targeted gene manipulation in the future.

Characterizations, relationship, and potential sources of outdoor and indoor particulate matter bound polycyclic aromatic hydrocarbons (PAHs) in a community of Tianjin, Northern China

Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. However, because there are unsubstantial data on indoor and outdoor particulate PAHs, efforts in assessing inhalation exposure and cancer risk to PAHs are limited in China. This study measured 12 individual PAHs in indoor and outdoor environments at 36 homes during the non-heating period and heating period in 2009. Indoor PAH concentrations were comparable with outdoor environments in the non-heating period, but were lower in the heating period. The average indoor/outdoor ratios in both sampling periods were lower than 1, while the ratios in the non-heating period were higher than those in the heating period. Correlation analysis and coefficient of divergence also verified the difference between indoor and outdoor PAHs, which could be caused by high ventilation in the non-heating period. To support this conclusion, linear and robust regressions were used to estimate the infiltration factor to compare outdoor PAHs to indoor PAHs. The calculated infiltration factors obtained by the two models were similar in the non-heating period but varied greatly in the heating period, which may have been caused by the influence of ventilation. Potential sources were distinguished using a diagnostic ratio and a mixture of coal combustion and traffic emission, which are major sources of PAHs.

Patient preference: a comparison of electronic patient-completed questionnaires with paper among cancer patients

In this study, we compared cancer patients preference for computerised (tablet/web-based) surveys versus paper. We also assessed whether the understanding of a cancer-related topic, pharmacogenomics is affected by the survey format, and examined differences in demographic and medical characteristics which may affect patient preference and understanding. Three hundred and four cancer patients completed a tablet-administered survey and another 153 patients completed a paper-based survey. Patients who participated in the tablet survey were questioned regarding their preference for survey format administration (paper, tablet and web-based). Understanding was assessed with a 'direct' method, by asking patients to assess their understanding of genetic testing, and with a 'composite' score. Patients preferred administration with tablet (71%) compared with web-based (12%) and paper (17%). Patients <65 years old, non-Caucasians and white-collar professionals significantly preferred the computerised format following multivariate analysis. There was no significant difference in understanding between the paper and tablet survey with direct questioning or composite score. Age (<65 years) and white-collar professionals were associated with increased understanding (both P = 0.03). There was no significant difference in understanding between the tablet and print survey in a multivariate analysis. Patients overwhelmingly preferred computerised surveys and understanding of pharmacogenomics was not affected by survey format.

First Report of Sclerotinia Stem Rot of Canola Caused by Sclerotinia sclerotiorum in Texas

During the past several years, canola (Brassica napus L.) has been grown experimentally in different areas of Texas to evaluate its potential as a crop, particularly for use as a biofuel source. In early April 2007, symptoms typical of Sclerotinia stem rot were observed in a canola variety trial that was flowering in Wharton County, Texas. Stems had white mycelia growing on the outside, or a bleached appearance, near the soil surface and plants were lodging. Inside bleached stems, there were spherical to cylindrical, black sclerotia that were 3 to 10 mm. Isolations from surface-disinfested stems onto potato dextrose agar (PDA) consistently yielded white, fluffy colonies with sclerotia typical of Sclerotinia sclerotiorum (Lib.) de Bary (1). Sequence analyses were conducted on two replicates of mycelium by extracting fungal DNA with the Qiagen DNeasy Plant Mini Kit (Valencia, CA). PCR amplification was performed using two primer sequences (92-4 AF377919: TCGCCTCAGAAGAATGTGC/AGCGGGTTACAAGGAGATGG; and 119-4 AF377925: GTAACAAGAGACCAAAATTCGG/TGAACGAGCTGTCATTCCC) (2) that have previously been used to characterize S. sclerotiorum (3). The BLAST search revealed that the sequences were 99 and 98% homologous with S. sclerotiorum Accession Nos. AF377919 and AF377925 over 376 and 377 bp of aligned sequence, respectively. Agar segments (1 cm²) from a 5-day-old culture grown on PDA were placed in the leaf axils of 15 2-month-old canola plants ('Wichita') growing in pots. Plants were placed in a humid chamber under fluorescent lights at 16 to 22°C. After 2 days, water soaking and necrosis occurred on petioles and stems adjacent to the inoculum, but not on plants treated with sterile PDA. S. sclerotiorum was consistently reisolated from symptomatic tissue plated on acidified PDA. The inoculations were repeated once with similar results. To our knowledge, this is the first report of Sclerotinia stem rot of canola in Texas. Currently, there is no significant canola production in Texas; however, interest in biofuels could lead to an increase in planted acres. Sclerotinia stem rot of canola could become a significant disease problem in areas of Texas where canola is planted as a winter crop. References: (1) L. M. Kohn. Phytopathology 69:881, 1979. (2) C. Sirjusingh and L. M. Kohn. Mol. Ecol. Notes 1:267, 2001. (3) J. E. Woodward et al. Plant Dis. 92:1468, 2008.

Antifungal Activity in Transgenic Peanut (Arachis hypogaea L.) Conferred by a Nonheme Chloroperoxidase Gene

A nonheme chloroperoxidase gene (cpo-p) from Pseudomonas pyrrocinia, a growth inhibitor of mycotoxin-producing fungi, was introduced into peanut via particle bombardment. The expression of the cpo-p gene is predicted to increase pathogen defense in peanut. Embryogenic peanut tissues were bombarded with gold particles coated with plasmid pRT66 carrying the cpo-p and hygromycin phosphotransferase (hph) genes, under the control of a double CaMV 35S and a single CaMV 35S promoter, respectively. Selection for hygromycin-resistant somatic embryos was performed on a liquid medium containing 10–20 mg/L hygromycin 3–4 days after bombardment. The integration and expression of the cpo-p gene was confirmed by Southern, Northern and Western blot analyses. In vitro bioassay using crude protein extracts from transgenic T0, T1, and T4 plants showed inhibition of Aspergillus flavus hyphal growth, which could translate to a reduction in aflatoxin contamination of peanut seed.

Repression of NFAT3 transcriptional activity by estrogen receptors

Nuclear factor of activated T cells 3 (NFAT3) activities have been implicated in many biological processes, such as breast cancer, cardiac hypertrophy, learning and memory, and adipocyte differentiation. However, how protein factors regulate NFAT3 transcriptional activity is poorly understood. Here, we report that regardless of estrogen, overexpression of estrogen receptor alpha and beta (ERalpha and ERbeta) suppresses NFAT3 transcriptional activity, whereas knockdown of endogenous ERalpha and ERbeta enhances the activity. Estrogen further enhances ER inhibition of NFAT3-dependent transcription. ERalpha and ERbeta interact with NFAT3 independently of the NFAT agonists phorbol myristate acetate (PMA) and ionomycin, and ERalpha is recruited to an NFAT3 target gene promoter. Phosphorylation of ERalpha at different sites differentially affects ERalpha modulation of NFAT3 transcriptional activity. These results suggest that ER may play a critical role in regulation of NFAT3 transcriptional activity.

Subinhibitory concentrations of cinnamaldehyde interfere with quorum sensing

AIMS

To investigate the effect of cinnamaldehyde (CA) on transcription from selected quorum sensing (QS) promoters.

METHODS AND RESULTS

The action of CA on QS was assayed using three E. coli green fluorescent protein (GFP) based bioreporters (two inducible and the other constitutive) and two Vibrio harveyi bioluminescent reporter strains. LuxR-mediated transcription from the P(luxI) promoter, which is induced by 3-oxo-C6-homoserine lactone (HSL), was reduced by 70 per cent following exposure to 200 micromol l(-1) CA (26 ppm). The bioluminescence of Vibrio harveyi BB886, which is mediated by 3-hydroxy-C4-HSL, was reduced by 55 per cent after exposure to 60 micromol l(-1) CA (8 ppm), and 100 micromol l(-1) CA (13 ppm) inhibited the bioluminescence of the autoinducer-2 (AI-2) responsive reporter strain V. harveyi BB170 by nearly 60 per cent. CA did not inhibit the growth of the bioreporter strains at these concentrations. CA had a minimal effect on LasR promoter activity, induced by 3-oxo-C12-HSL.

CONCLUSIONS

Low concentrations of CA were effective at inhibiting two types of acyl homoserine lactone mediated QS, and also autoinducer-2 mediated QS.

SIGNIFICANCE AND IMPACT OF STUDY

Because CA is widely used in the food and flavour industries, its potential to affect bacterial QS regulated processes should be recognized.

Colorimetric method for identifying plant essential oil components that affect biofilm formation and structure

The specific biofilm formation (SBF) assay, a technique based on crystal violet staining, was developed to locate plant essential oils and their components that affect biofilm formation. SBF analysis determined that cinnamon, cassia, and citronella oils differentially affected growth-normalized biofilm formation by Escherichia coli. Examination of the corresponding essential oil principal components by the SBF assay revealed that cinnamaldehyde decreased biofilm formation compared to biofilms grown in Luria-Bertani broth, eugenol did not result in a change, and citronellol increased the SBF. To evaluate these results, two microscopy-based assays were employed. First, confocal laser scanning microscopy (CLSM) was used to examine E. coli biofilms cultivated in flow cells, which were quantitatively analyzed by COMSTAT, an image analysis program. The overall trend for five parameters that characterize biofilm development corroborated the findings of the SBF assay. Second, the results of an assay measuring growth-normalized adhesion by direct microscopy concurred with the results of the SBF assay and CLSM imaging. Viability staining indicated that there was reduced toxicity of the essential oil components to cells in biofilms compared to the toxicity to planktonic cells but revealed morphological damage to E. coli after cinnamaldehyde exposure. Cinnamaldehyde also inhibited the swimming motility of E. coli. SBF analysis of three Pseudomonas species exposed to cinnamaldehyde, eugenol, or citronellol revealed diverse responses. The SBF assay could be useful as an initial step for finding plant essential oils and their components that affect biofilm formation and structure.

Acetylenic TACE inhibitors. Part 1. SAR of the acyclic sulfonamide hydroxamates

The SAR of a series of potent sulfonamide hydroxamate TACE inhibitors, all bearing a butynyloxy P1' group, was explored. In particular, compound 5j has excellent in vitro potency against isolated TACE enzyme and in cells, good selectivity over MMP-1 and MMP-9, and oral activity in an in vivo model of TNF-alpha production and a collagen-induced arthritis model.

[Immunoregulation of IL-2 in Trichinella-infected mice]

AIM

To study the immunoregulation of IL-2 in Trichinella-infected mice.

METHODS

Mice infected respectively with HL strain and AM strain larvae of Trichinella spiralis were treated i.p. with IL-2 from the second day postinfection for 3 days. Serum IgG antibody levels were determined by ELISA and the infection capacity was determined using reproductive capacity index (RCI).

RESULTS

In HL, higher dosage of IL-2 injection induced lower RCI and showed apparent anti-Trichinella effect. In AM, both low and high dose of IL-2 had no measurable effect on RCI, however, high dose of IL-2 reduced the infectivity of newborn larvae.

CONCLUSION

IL-2 exhibits apparent suppressive effect on the infectivity of T. spiralis of HL strain.

[Sensitivity and specificity of nested polymerase chain reaction in detecting Plasmodium vivax in infected mosquitoes]

AIM

To study the sensitivity and specificity of nested polymerase chain reaction for detection of Plasmodium vivax in infected mosquitoes.

METHODS

Two pairs of primers specific to small subunit ribosomal DNA of P. vivax were used to amplify the specific SSUrDNA 121 bp fragment of P. vivax for detecting P. vivax-infected mosquitoes with nested PCR.

RESULTS

Nested PCR could detect as few as 3 sporozoites in one mosquito or 1 infected mosquito mixed with a group of 99 normal ones. In contrast, no such specific 121 bp DNA band was detected in P. falciparum, P. cynomolgi, P. yoelii yoelii infected samples, nor in normal mosquito.

CONCLUSION

The nested PCR technique we established showed high sensitivity and specificity.

Gene expression in CD34(+) cells from normal bone marrow and leukemic origins

INTRODUCTION

To address the molecular regulation of hematopoiesis and the complex mechanism in leukemogenesis, we established the first catalogs of genes expressed in normal bone marrow and leukemia CD34(+) cells.

MATERIALS AND METHODS

CD34(+) cell cDNA libraries were constructed using mRNA from adult bone marrow and from a case of acute myeloid leukemia-M5 transformed from myelodysplastic syndrome (MDS-AML). Expressed sequence tags (ESTs) and full-length cDNAs were generated by sequencing and were annotated using bioinformatic tools.

RESULTS

From a total of 4142 ESTs obtained from normal bone marrow, 3424 meaningful tags were integrated into 1630 clusters, representing 622 known genes, 522 dbEST entries and 486 novel sequences. Out of 5382 ESTs from MDS-AML, 1985 clusters were produced based on the analysis of 4321 useful ESTs, including 711 known genes, 657 known ESTs and 617 novel sequences. Among 251 transcripts found in both bone marrow and MDS-AML EST datasets and those present in only one dataset, 58 showed statistically significant differences in EST copy numbers between the two tissues (P<0.05). Twenty putative full-length cDNAs for novel genes were also cloned from the MDS-AML library.

CONCLUSION

The distinct gene expression patterns in MDS-AML-CD34(+) cells as compared to normal control cells may contribute to the development and/or maintenance of the malignant phenotypes of leukemia cells.

DNA transfer by highly asymmetric somatic hybridisation in Medicago truncatula (+) Medicago rugosaand Medicago truncatula(+) Medicago scutellata

A regenerable line of Medicago truncatula(Jemalong 2HA) as a recipient species, was fused with the sexually incompatible species Medicago scutellataor Medicago rugosa.The treatments described maintain the chromosome number of the recipient but enable the transfer of small amounts of DNA of the donor species, probably by intergenomic recombination. Without a chromosome number-change fusion products can readily regenerate to produce fertile plants; and potentially a library with a diverse array of new genetic material. The selection of fused cells is based on treatment of the recipient cells with iodoacetamide (IOA), a non-regenerable donor, gamma-irradiation of the donor, and regeneration on a medium favouring the recipient. DNA transfer was demonstrated by amplified fragment length polymorphism (AFLP), Southern hybridisation and changed morphology.

Molecular cytogenetic characterization and clinical relevance of additional, complex and/or variant chromosome abnormalities in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is characterized by typical morphological manifestation, t(15;17) translocation and active response to all-trans retinoic acid (ATRA) in the great majority of patients. However, a subset of APL cases may present atypical phenotypic, cytogenetic or molecular features at different stages of the disease. The biological and clinical significance of these features sometimes remains obscure. In this study, 284 APL patients were cytogenetically analyzed and precise diagnosis was performed according to the molecular cytogenetic results. Twenty-six APL patients were identified as having additional, complex and/or variant chromosomal abnormalities at diagnosis or at relapse, 16 of them being further analyzed using fluorescence in situ hybridization (FISH) or chromosome painting (CP). Interestingly, some of these chromosomal aberrations were found to be associated with atypical morphology and/or drug response, indicating a genotype-phenotype correlation. Analysis of the complex karyotype may also allow a better understanding of the levels of cellular origin of the leukemogenesis. Examination of the remission induction and survival data showed that the presence of the additional/complex chromosome abnormalities was related to the prognosis in both primarily diagnosed and relapsed patients in this series.

Novel (4-piperidin-1-yl)-phenyl sulfonamides as potent and selective human beta(3) agonists

A series of novel (4-piperidin-1-yl)-phenyl sulfonamides was prepared and evaluated for their biological activity on the human beta(3)-adrenergic receptor (AR). Replacement of the 3,4-dihydroxyl group of the catechol moiety with 4-hydroxyl-3-methyl sulfonamide on the left-hand side of the compounds resulted in a number of potent full agonists at the beta(3) receptor. Modification of the right-hand side of the compounds by incorporation of a free carboxylic acid resulted in a few potent human beta(3) agonists with low affinities for beta(1)- and beta(2)-ARs. N-Alkyl substitution on the 4-piperidin-1-yl-phenylamine further increased the beta(3) potency while maintaining the selectivity. For example, sulfonamide 48 is a potent full beta(3) agonist (EC(50)=0.004 microM, IA=1.0) with > 500-fold selectivity over beta(1)- and beta(2)-ARs.

Studies on the clinical efficacy and pharmacokinetics of low-dose arsenic trioxide in the treatment of relapsed acute promyelocytic leukemia: a comparison with conventional dosage

Twenty cases of patients with relapsed acute promyelocytic leukemia (APL) were entered into this study for evaluating the clinical efficacy and pharmacokinetics of low-dose arsenic trioxide (As2O3). As2O3 was given at a daily dose of 0.08 mg/kg intravenously for 28 days. Pharmacokinetic study was carried out in eight patients. 16/20 (80%) patients achieved CR. The occurrence of some toxic events including gastrointestinal disturbance, facial edema and cardiac toxicity seemed reduced in the low-dose group than those in the standard-dose group. Differentiation changes were observed in peripheral blood, as well as in bone marrow (BM). Pharmacokinetic study showed that the plasma concentration increased soon after administration of As2O3 with the peak values of 1.535-3.424 micromol/l. After infusion, the plasma concentration was around 0.1-0.5 micromol/l. The arsenic concentration of the plasma of BM aspirates 24 h after administration in five patients was close to the level needed for differentiation-inducing effect. The estimated 2-year OS and RFS were 61.55+/-15.79% and 49.11+/-15.09% respectively, with no difference as compared with those in patients treated with conventional dose (P = 0.2865 and 0.7146, respectively). In conclusion, we demonstrated that low-dose As2O3 had the same effect as the conventional dosage and the mechanism of low-dose arsenic seemed to primarily induce differentiation of APL cells.

Nested polymerase chain reaction in detection of Plasmodium vivax sporozoites in mosquitoes

OBJECTIVE

To detect malaria DNA in mosquitoes.

METHODS

A nested polymerase chain reaction (nested PCR) procedure which amplifies a 121 bp DNA of a SSUrRNA gene specific to Plasmodium vivax was used.

RESULTS

In laboratory-infected mosquitoes, nested PCR could detect as few as 3 sporozoites or 1 infected mosquito mixed in a group of 99 normal ones. Furthermore, no specific 121 bp band was seen with DNA templates from other malaria parasites or negative mosquitoes.

CONCLUSION

Sensitivity and specificity obtained indicated an advantage of the nested PCR over DNA probes or direct PCR for the detection of Plasmodium vivax sporozoites in mosquitoes with low-grade parasitic infections.

Feasibility and clinical significance of real-time quantitative RT-PCR assay of PML-RARalpha fusion transcript in patients with acute promyelocytic leukemia

INTRODUCTION

To study the relationship between the expression level of the PML-RARalpha fusion transcripts and the clinical status and efficiency of the therapy in acute promyelocytic leukemia (APL) patients, we applied a very sensitive and specific real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) system to quantify the dose of PML-RARalpha fusion transcripts in a series of APL patients at distinct disease stages.

MATERIALS AND METHODS

A total of 31 APL patients (19 males and 12 females; aged from 8 to 74 years) from eight hospitals in Shanghai were analysed. Real-time Quantitative RT-PCR was used to measure the normalized dose (DoseN) of PML-RARalpha fusion transcripts.

RESULTS

A wide range of PML-RARalpha DoseN above 1 x 10(3) was noted in 25 newly diagnosed patients. PML-RARalpha DoseN was significantly decreased after remission induction with ATRA, ATRA/chemotherapy or As2O3 and further reduced after consolidation. The fact that all patients with long disease free survival had a constantly low PML-RARalpha DoseN below 2 x 10(2) and a higher level predicted impending relapse suggests that this value could serve as a 'threshold' for molecular remission. PML-RARalpha DoseN was also of prognostic value in a group of relapsed patients, since good response to As2O3 reinduction was accompanied by a remarkable reduction of fusion transcript level, whereas patients with high PML-RARalpha Dose(N) after the second CR tended to relapse again rapidly.

CONCLUSION

These results confirm that real-time RT-PCR assay for PML-RARalpha transcripts in APL patients is useful in reflecting leukemic burden, assessing response to treatment and indicating the ultimate clinical outcome or curability of disease.