A 6-month randomized, double-blind, placebo-controlled trial of weekly exenatide in adolescents with obesity.

BACKGROUND: Pharmacological treatment options for adolescents with obesity are very limited. Glucagon-like-peptide-1 (GLP-1) receptor agonist could be a treatment option for adolescent obesity. OBJECTIVE: To investigate the effect of exenatide extended release on body mass index (BMI)-SDS as primary outcome, and glucose metabolism, cardiometabolic risk factors, liver steatosis, and other BMI metrics as secondary outcomes, and its safety and tolerability in adolescents with obesity. METHODS: Six-month, randomized, double-blinded, parallel, placebo-controlled clinical trial in patients (n = 44, 10-18 years, females n = 22) with BMI-SDS > 2.0 or age-adapted-BMI > 30 kg/m2 according to WHO were included. Patients received lifestyle intervention and were randomized to exenatide extended release 2 mg (n = 22) or placebo (n = 22) subcutaneous injections given once weekly. Oral glucose tolerance tests (OGTT) were conducted at the beginning and end of the intervention. RESULTS: Exenatide reduced (P < .05) BMI-SDS (-0.09; -0.18, 0.00), % BMI 95th percentile (-2.9%; -5.4, -0.3), weight (-3 kg; -5.8, -0.1), waist circumference (-3.2 cm; -5.8, -0.7), subcutaneous adipose tissue (-552 cm3 ; -989, -114), 2-hour-glucose during OGTT (-15.3 mg/dL; -27.5, -3.1), total cholesterol (11.6 mg/dL; -21.7, -1.5), and BMI (-0.83 kg/m2 ; -1.68, 0.01) without significant change in liver fat content (-1.36; -3.12, 0.4; P = .06) in comparison to placebo. Safety and tolerability profiles were comparable to placebo with the exception of mild adverse events being more frequent in exenatide-treated patients. CONCLUSIONS: Treatment of adolescents with severe obesity with extended-release exenatide is generally well tolerated and leads to a modest reduction in BMI metrics and improvement in glucose tolerance and cholesterol. The study indicates that the treatment provides additional beneficial effects beyond BMI reduction for the patient group.

Genetically modified plants for non-food or non-feed purposes: straightforward screening for their appearance in food and feed.

Genetically modified (GM) plants aimed at producing food/feed are part of regular agriculture in many areas of the World. Commodity plants have also found application as bioreactors, designated non-food/non-feed GM (NFGM) plants, thereby making raw material for further refinement to industrial, diagnostic or pharmaceutical preparations. Many among them may pose health challenge to consumers or livestock animals, if occurring in food/feed. NFGM plants are typically released into the environment, but are grown under special oversight and any among several containment practices, none of which provide full protection against accidental dispersal. Adventitious admixture with food or feed can occur either through distributional mismanagement or as a consequence of gene flow to plant relatives. To facilitate NFGM surveillance we propose a new mandatory tagging of essentially all such plants, prior to cultivation or marketing in the European Union. The suggested tag--Plant-Made Industrial or Pharmaceutical Products Tag (PMIP-T)--is envisaged to occur as a transgenic silent DNA identifier in host plants and designed to enable technically simple identification and characterisation of any NFGM. Implementation of PMIP-T would permit inexpensive, reliable and high-throughput screening for NFGM specifically. The paper outlines key NFGM prospects and challenges as well as the PMIP-T concept.

Parallel DNA template preparation using a vacuum filtration sample transfer device.

Solid-phase techniques have facilitated the handling of biochemical analytes. This has stimulated the development of systems by which large sample panels can be analyzed with high levels of security and quality. We describe a sample transfer device based on the principle of vacuum filtration, which enables parallel handling of 96 samples of analytes bound to Sepharose beads. The tool was employed for strand separation of DNA samples, by attracting the beads to filter probes while passing them between the reagent solutions. The samples were analyzed using Pyrosequencing technology and proved to yield genotyping results of high quality. The presented sample preparation procedure provides an important link in the development of integrated systems for rapid genetic analysis at a low cost. In addition, the same filter could be reused extensively with very low risk for detectable cross-contamination between assays and without any reduction in processing capacity, thus further reducing the cost per analyzed sample.

Mitochondrial sequence analysis for forensic identification using pyrosequencing technology.

Over recent years, requests for mtDNA analysis in the field of forensic medicine have notably increased, and the results of such analyses have proved to be very useful in forensic cases where nuclear DNA analysis cannot be performed. Traditionally, mtDNA has been analyzed by DNA sequencing of the two hypervariable regions, HVI and HVII, in the D-loop. DNA sequence analysis using the conventional Sanger sequencing is very robust but time consuming and labor intensive. By contrast, mtDNA analysis based on the pyrosequencing technology provides fast and accurate results from the human mtDNA present in many types of evidence materials in forensic casework. The assay has been developed to determine polymorphic sites in the mitochondrial D-loop as well as the coding region to further increase the discrimination power of mtDNA analysis. The pyrosequencing technology for analysis of mtDNA polymorphisms has been tested with regard to sensitivity, reproducibility, and success rate when applied to control samples and actual casework materials. The results show that the method is very accurate and sensitive; the results are easily interpreted and provide a high success rate on casework samples. The panel of pyrosequencing reactions for the mtDNA polymorphisms were chosen to result in an optimal discrimination power in relation to the number of bases determined.

Pyrosequencing as a method for grouping of Listeria monocytogenes strains on the basis of single-nucleotide polymorphisms in the inlB gene.

By using pyrosequencing (i.e., sequencing by synthesis) 106 strains of different serovars of Listeria monocytogenes were rapidly grouped into four categories based on nucleotide variations at positions 1575 and 1578 of the inlB gene. Strains of serovars 1/2a and 1/2c constituted one group, and strains of serovars 1/2b and 3b constituted another group, whereas serovar 4b strains were separated into two groups.

Screening and scanning of single nucleotide polymorphisms in the pig melanocortin 1 receptor gene (MC1R) by pyrosequencing.

The increasing interest in the discovery and characterization of single nucleotide polymorphisms (SNPs) emphasis the need for high-throughput and cost effective scoring methods. Pyrosequencing is a novel method for screening SNPs. In this study we examine breed specific SNPs in the pig melanocortin 1 receptor gene (MC1R), some causing coat color phenotypes. A total of fifteen pigs representing eight breeds and crosses were analyzed by pyrosequencing. In addition to nine previously known SNPs, we also detected one new missense mutation by pyrosequencing. We here show that the SNPs were readily scored using standard reaction conditions. Insertions as well as substitutions were unambiguously detected and all genotypes were resolved in terms of homo- and heterozygozity.

Determination of single-nucleotide polymorphisms by real-time pyrophosphate DNA sequencing.

The characterization of naturally occurring variations in the human genome has evoked an immense interest during recent years. Variations known as biallelic Single-Nucleotide Polymorphisms (SNPs) have become increasingly popular markers in molecular genetics because of their wide application both in evolutionary relationship studies and in the identification of susceptibility to common diseases. We have addressed the issue of SNP genotype determination by investigating variations within the Renin-Angiotensin-Aldosterone System (RAAS) using pyrosequencing, a real-time pyrophosphate detection technology. The method is based on indirect luminometric quantification of the pyrophosphate that is released as a result of nucleotide incorporation onto an amplified template. The technical platform employed comprises a highly automated sequencing instrument that allows the analysis of 96 samples within 10 to 20 minutes. In addition to each studied polymorphic position, 5-10 downstream bases were sequenced for acquisition of reference signals. Evaluation of pyrogram data was accomplished by comparison of peak heights, which are proportional to the number of incorporated nucleotides. Analysis of the pyrograms that resulted from alternate allelic configurations for each addressed SNP revealed a highly discriminating pattern. Homozygous samples produced clear-cut single base peaks in the expected position, whereas heterozygous counterparts were characterized by distinct half-height peaks representing both allelic positions. Whenever any of the allelic bases of an SNP formed a homopolymer with adjacent bases, the nonallelic signal was added to those of the SNP. This feature did not, however, influence SNP readability. Furthermore, the multibase reading capacity of the described system provides extensive flexibility in regard to the positioning of sequencing primers and allows the determination of several closely located SNPs in a single run.

Detailed genetic and physical mapping in the Sjögren-Larsson syndrome gene region in 17p11.2.

Sjögren-Larsson syndrome (SLS) is an autosomal recessive disorder characterised by mental retardation, spasticity, and ichthyosis. In 1994, SLS was linked to chromosome 17 and the gene causing the disorder was recently identified as fatty aldehyde dehydrogenase (FALDH) located in 17p11.2. In this paper we present a detailed genetic and physical map of the region surrounding the SLS/FALDH locus, produced by using new microsatellite markers analysed on the extensive Swedish family material, a radiation hybrid panel, and yeast artificial chromosomes (YACs).

Venous thrombosis: factor V G1691A genotyping related to APC resistance as measured by 2 methods.

Blood samples were collected from consecutive unrelated patients with venous thrombosis. The patients originate from the middle part of Sweden. We investigated the presence of the reported point mutation at nt 1691 of factor V which renders the protein resistant to cleavage by activated protein C (APC). Thirty-seven per cent of the patients were heterozygote carriers, and 4.5% were homozygotes for a mutated factor V gene. In addition, resistance to coagulation induced by APC was measured, both by the conventional APTT assay and by a modified APTT assay which has been reported to have an increased resolution. Compared to a control group of healthy people, the mean value was significantly lower in the patient group. A strong correlation between low APC ratio and presence of the factor V mutation was found. By using the modified method, a complete resolution of carriers of the factor V mutation and people with normal factor V alleles was found. However, there was still an overlap between heterozygote carriers and people homozygous for the mutation. The modified method was also found useful in patients treated with warfarin. Among 40 healthy blood donors 7% were found to be heterozygous.

Achondroplasia in Sweden caused by the G1138A mutation in FGFR3.

Achondroplasia, an autosomal dominant inherited disorder, is one of the most common forms of skeletal dysplasia resulting in disproportionate extreme shortness. Recently, two point mutations, both affecting nucleotide 1138 in the fibroblast growth factor receptor type 3 (FGFR3) gene, were found to be the cause of the disorder. We investigated DNA from 16 Swedish patients with achondroplasia for the presence of these mutations. All patients were found to be heterozygous for the G to A transition at nucleotide 1138. Our data thus support previous reports showing a striking genetic homogeneity, in that almost all achondroplasia patients have the FGFR3 G380R mutation at the protein level.

Regulation of DNA synthesis in division-arrested mouse C127 cells permissive for bovine papillomavirus DNA amplification.

Spontaneous amplification of bovine papillomavirus type 1 DNA occurs following a prolonged period of serum starvation of wild-type virus-transformed C127 cell lines and is associated with abundant viral E2 protein synthesis and a concomitant induction of viral oncogene (E5 and E6) expression. We show here that a subpopulation of the permissive cells incorporate bromo-deoxyuridine under conditions of cell growth arrest (serum starvation), whereas DNA synthesis is suppressed in the resting population of nonpermissive cells. Flow cytometric measurements of the cellular DNA content of the permissive cell population indicated that it contained predominantly a 4n DNA content, suggesting that these cells were blocked in the G2 phase of the cell cycle. In keeping with the hypothesis that viral DNA amplification is associated with the induction of a cellular S phase, we observed a specific induction of expression of two cell proliferation-related cellular antigens (PCNA and Ki67) in a subpopulation of permissive cells. C127 cell lines transformed by an E5-minus bovine papillomavirus type 1 mutant, which was competent for autonomous plasmid replication in mitotic cells, were completely defective for the induction of DNA synthesis and mutant viral DNA amplification under conditions of serum starvation. Moreover, the E5 protein is shown by immunofluorescence analysis to be expressed at a high level specifically in the permissive cell population. These results imply a dual role for the viral E5 protein in the C127 model system, both as a transforming protein and as a factor required for the induction of viral DNA amplification in postmitotic cells. We suggest that E5 acts at an early step in the induction of this process in C127 cells and may be required to turn on host cell DNA synthesis as a prerequisite for viral DNA amplification.

Segregation properties of bovine papillomaviral plasmid DNA.

Essentially complete segregation of replication-competent BPV-1 plasmid DNA species was observed in daughter subclones derived from primary co-transformed C127 cell lines. Thus, whereas primary co-transformants retained both of two distinguishable co-transfected plasmid species, subcloning experiments revealed that morphologically transformed daughter subclones derived from such co-transformed cell lines contained only one species of viral plasmid DNA. Similar results were obtained with each of two conveniently marked replication and transformation-competent mutants: one with a linker-insertion in the viral upstream regulatory region, and one with a 260 base-pair deletion within the L2 (late) gene, which has no recognized role in plasmid replication or stability. Morphological revertant cell clones that contained no detectable viral plasmid DNA genomes were also isolated at a surprisingly high frequency from clonal wild-type BPV-1 transformed cell lines and from cell lines transformed by various BPV-1 mutants. Further co-transfection experiments were done with a combination of transformation-competent and transformation-defective BPV-1 genomes to investigate a possible role for a viral oncogene in plasmid persistence. In this case, elimination of the transformation-defective mutant was observed after the initial establishment of both input genomes as replicating plasmids in cell clones morphologically transformed by the transformation-competent viral mutant with an intact E5 oncogene. No cell subclones were isolated that contained only the transformation-defective mutant, implying that it was defective in long-term plasmid persistence. Our results indicate that there is significant randomization in the processes of replication and/or partitioning of the BPV-1 genome in mouse C127 cells, and, in combination with previous observations, also suggest that BPV plasmid persistence in C127 cell lines may be the result of a selective proliferative advantage conferred on virus-infected cells by viral oncogene-induced cell growth transformation.

Evidence that the transcriptional trans-activating function of the bovine papillomavirus type 1 E2 gene is not required for viral DNA amplification in division-arrested cells.

Amplification of bovine papillomavirus type 1 (BPV-1) DNA in growth-arrested mouse cell cultures appears to mimic the process of induction of vegetative BPV-1 DNA synthesis in cells of the stratum spinosum in productively infected bovine warts. In both cases, cells permissive for viral DNA amplification express large amounts of viral E2 protein which accumulates within the cell nucleus. Whereas in latently infected virus-transformed cells truncated transcriptional repressor forms of E2 predominate, our previous studies have demonstrated that the full-length E2 transcriptional trans-activator protein is preferentially expressed during the period of maximal BPV-1 DNA amplification in growth-arrested cell cultures. To investigate the role of the full-length E2 gene in the induction of viral DNA amplification in this experimental viral replication system we have used a mutant BPV-1 genome (BPVE2-ts1) containing an E2 gene which is temperature-sensitive (ts) for transcriptional trans-activation. This mutant genome has also been shown to be ts for stable viral plasmid DNA replication and for the induction of cell transformation. We show here that viral DNA amplification was not severely impaired when BPVE2-ts1-transformed cells were tested at the restrictive temperature, indicating that the transcriptional trans-activating function of E2 was not essential for viral DNA amplification in division-arrested cells and, moreover, that the trans-activation and replication functions of E2 were separable. Consistent with this hypothesis, amplification of the BPVE2-ts1 genome at the restrictive temperature was still associated with the accumulation of large amounts of nuclear E2 antigen, showing that the mutation did not disrupt nuclear transport or render the E2 protein highly unstable. Furthermore, C127 cells harbouring ts E2 and full-length E1 expression constructs supported transient plasmid replication of a BPV origin vector at the restrictive temperature. These observations imply that E2 functions primarily as a viral replication factor in the vegetative phase of BPV-1 DNA replication, and suggest a fundamental difference in the genetic regulation of stable BPV-1 plasmid DNA replication in mitotic cells and viral DNA amplification in postmitotic cells.

Identification and genetic definition of a bovine papillomavirus type 1 E7 protein and absence of a low-copy-number phenotype exhibited by E5, E6, or E7 viral mutants.

The bovine papillomavirus type 1 (BPV-1) genome replicates as a multiple-copy plasmid in murine C127 cells transformed to neoplasia by virus infection or by transfection with BPV-1 DNA. It was reported previously that BPV-1 genomes harboring frameshift mutations in the E6 or E7 open reading frame (ORF) replicated in C127 cells transformed by these mutants at a low copy number. Furthermore, the characterization of a BPV-1 mRNA in which the E6 and E7 ORFs were spliced together in frame has led to the assumption that an E6/7 fusion protein is expressed in virus-transformed C127 cells. To define the number and nature of the E6 and E7 gene products expressed in BPV-1-transformed cells, we performed immunoprecipitation experiments with antisera raised to bacterially expressed BPV-1 E6 and E7 fusion proteins. By employing cell culture conditions which induce BPV-1 E2 transactivator expression and viral early region transcription in virus-transformed C127 cell lines, we detected a single immunoprecipitated E6 protein species with an apparent molecular mass of 17 kDa and a single E7 protein species with an apparent molecular mass of 15 kDa. To characterize further these E6 and E7 proteins, C127 cells were transformed by transfection with BPV-1 genomes containing mutations predicted to prevent expression of specific E6 or E7 gene products, and the transformed cells were subjected to immunoprecipitation analysis with the E6 or E7 antiserum. The results of these experiments confirmed that the E6 and E7 ORFs encode distinct proteins and failed to establish the existence of an E6/7 fusion protein. We did not find a significant difference in the viral genome copy number between clonal C127 cell lines transformed by wild-type BPV-1 or by mutant viral genomes unable to express the E6 or the E7 protein. Furthermore, in contrast to two previous reports suggesting that expression of the BPV-1 E5 gene was required for the establishment or maintenance of a high viral plasmid copy number, we observed a two- to fourfold increase over wild-type BPV-1 plasmid copy number in C127 cells transfected with a BPV-1 E5-minus mutant and subsequently selected by neoplastic focus formation.

Induction of bovine papillomavirus E2 gene expression and early region transcription by cell growth arrest: correlation with viral DNA amplification and evidence for differential promoter induction.

The bovine papillomavirus type 1 (BPV-1) genome replicates as a latent plasmid in mouse C127 cells transformed in vitro by the virus. However, we have recently shown that BPV-1 DNA amplification can be induced in a subpopulation of cells under culture conditions which suppress cell proliferation, a finding which led us to hypothesize that expression of a viral replication factor was regulated by cell growth stage. In this report, we describe the detection in these cells of abundant BPV-1 nuclear E2 antigen by immunofluorescence analysis. Expression of E2 antigen in fibropapilloma tissue was similarly localized to nonproliferating epidermal cells of the lower spinous layers--the natural site of induction of vegetative viral DNA replication. Immunoprecipitation analysis showed that the previously characterized 48-kilodalton (transactivator) and 31-kilodalton (repressor) E2 proteins were both induced in growth-arrested cell cultures. In parallel with E2 antigen synthesis under conditions of serum-deprivation in vitro, we observed a significant increase in levels of BPV-1 early region mRNAs. Furthermore, we present evidence for preferential induction of the P2443 promoter, in addition to specific induction of the P7940 promoter in response to serum deprivation. These observations indicate a central role for E2 transcription factors in the induction of viral DNA amplification in division-arrested cells in vitro and in vivo and suggest that this process is associated with a qualitative switch in the expression of viral early region genes.

Transcriptional activation of the human papillomavirus-16 P97 promoter by an 88-nucleotide enhancer containing distinct cell-dependent and AP-1-responsive modules.

The P97 promoter upstream of the oncogenic early genes of human papillomavirus (HPV)-16 is active in keratinocytes and in cervical carcinoma cells due to a 5' keratinocyte-dependent cis enhancer. In this study, we have mapped the main enhancer activity to an 88-nucleotide (nt) fragment composed of multiple cis elements. A 63-nt promoter-proximal enhancer core was sufficient for P97 activation in a human keratinocytic cell line, HaCaT, and in cervical carcinoma cells. Although the enhancer functioned poorly in hepatoma cells or in fibroblasts, nuclear extracts from different cells protected similar cis elements from DNase I digestion. Two protected half-palindromic NF-I/CTF sites within the 63-nt core were necessary for its function; one represents a "cytokeratin element" (CK), a previously described 8-nt sequence shared with cytokeratin gene promoters. Both sites formed complexes of the same apparent size and relative binding affinity with NF-I/CTF-like factor(s) present in all cells tested. Although cell-dependent P97 activation could be determined by similar, yet distinct NF-I/CTF-like proteins, adjacent cis elements in the enhancer core were also required for function, and may thus interact with additional transcription factors. A 25-nt distal module with two AP-1 sites increased enhancer activity and cooperated with cis elements of the proximal core. Each AP-1 site as well as a third AP-1 site near the promoter bound c-Jun and Jun/Fos in vitro, and was activated by c-Jun and c-Fos in transfections. In addition to cell type-dependent activation, HPV-16 P97 transcription may therefore respond to growth factors and oncogene products via the AP-1 pathway.