Awareness of prostate cancer among patients and the general public: results of an international survey.

The objective of this study was to assess the level of awareness of prostate cancer (PCa) among the general public and PCa patients in Europe and North America. A survey was undertaken across four European countries (UK, Germany, Italy and Spain), and across the United States and Canada in late 2007. In total, 1008 men with PCa and their partners (the 'prostate sample'), and 911 men without PCa and their partners (the 'well sample') participated in the survey, all aged > or =50 years. Interviews were conducted through telephone, pen and paper, and online. Many people surveyed (53%) thought that breast cancer is more common than PCa. Moreover, 1 in 10 people from the well sample (10%) thought that PCa affects both men and women. When the prostate sample was asked about their perceived level of risk of PCa before diagnosis, 50% believed that they/their husband or partner were previously at low or very low risk, before they were diagnosed. Awareness of the major risk factors for PCa (age and family history) was generally good, but respondents were less clear about the role of other potential factors, such as smoking and drinking alcohol. This international survey, thought to be largest of its type, shows that although patient and public awareness of PCa is generally satisfactory, there is still a considerable lack of clarity about PCa risk factors, and a danger for people to underestimate their own/their partner's perceived risk for PCa. Programmes to responsibly educate and inform men and their partners about risk factors, prevalence and screening tools for PCa are required.

Specificity of acyltransferases and their genetic manipulation for environmental adaptation and development of new industrial oils.

The biosynthesis of complex lipids involves specific acylation reactions catalysed by acyltransferases. These reactions are important for the formation of both storage lipids, triacylglycerols, as well as structural lipids such as phospholipids and galactolipids. The current status of our understanding of the specificity, selectivity, structure, cloning and genetic manipulation of these enzymes is reviewed. These studies clearly indicate the possibilities of selecting appropriate acyltransferases to produce designer lipids with defined acyl groups at different positions of the triglyceride molecule. In separate transgenic studies manipulation of these enzymes has demonstrated a dramatic alteration in the chilling sensitivity of plants.

Identification of a cDNA that encodes a 1-acyl-sn-glycerol-3-phosphate acyltransferase from Limnanthes douglasii.

Two different techniques were used to isolate potential cDNAs for acyl-CoA: 1-acyl-sn-glycerol-3-phosphate acyltransferase (LPA-AT) enzymes from Limnanthes douglasii. Both heterologous screening with the maize pMAT1 clone and in vivo complementation of the Escherichia coli mutant JC201 which is deficient in LPA-AT activity, were carried out. Clones identified by these procedures were different. Homology searches demonstrated that the clone isolated by heterologous probing, pLAT1, encodes a protein which is most similar to the maize (open reading frame in pMAT1) and yeast SLC1 proteins, which are putative LPA-AT sequences. This L. douglasii sequence shows much lower homology to the E. coli LPA-AT protein PlsC, which is the only LPA-AT sequence confirmed by over-expression studies. The clone isolated by complementation, pLAT2, encodes a protein with homology to both SLC1 and PlsC. It was not possible to over-express the complementing protein encoded by pLAT2 but further experimentation on membranes from complemented JC201 demonstrated that they possess a substrate specificity distinctly different from PlsC and similar to Limnanthes sp. microsome specificity. This data strongly supports the contention that pLAT2 is an LPA-AT clone. Northern blot analysis revealed different expression patterns for the two genes in pLAT1 and pLAT2. Transcription of the gene encoding the insert of pLAT2 occurred almost exclusively in developing seed tissue, whilst the cDNA of pLAT1 hybridised to poly(A)+ mRNA from seed, stem and leaf, demonstrating more widespread expression throughout the plant. Southern blot analysis indicated that the cDNA of pLAT2 was transcribed from a single-copy gene while that for pLAT1 was a member of a small gene family.

Transfection of heteroduplexes containing uracil.guanine or thymine.guanine mispairs into plant cells.

We have compared the fate of U.G mispairs or analogous T.G mispairs in DNA heteroduplexes transfected into tobacco protoplasts. The heteroduplex DNA consisted of tomato golden mosaic virus DNA sequences in the Escherichia coli vectors pUC118 or pUC119. After transfection, the mismatched U residues were lost with an efficiency of greater than 95%, probably as a result of the uracil-DNA glycosylase pathway for excision of U residues in any sequence context. In contrast to the preferential removal of the mispaired U residues, biased removal of T residues from analogous heteroduplexes was not seen in the transfected plant cells. Also, we investigated the effect of extensively methylating one strand of the heteroduplex DNA used for transfection. Surprisingly, such methylation resulted in highly biased loss of the mismatched base from the 5-methylcytosine-rich strand of T.G-containing heteroduplexes.

Kinetics of tomato golden mosaic virus DNA replication and coat protein promoter activity in Nicotiana tabacum protoplasts.

We have analyzed the replication kinetics of the DNA A and DNA B genome components of the geminivirus tomato golden mosaic virus (TGMV) in protoplasts derived from Nicotiana tabacum suspension culture. In addition, the kinetics of TGMV coat protein promoter activity, as measured by expression of a beta-glucuronidase (GUS) reporter, have been examined. In our protoplast system, double-stranded DNA forms of both viral genome components appeared by 18 hr post-transfection, while single-stranded DNA accumulated to detectable levels after 18-24 hr. Expression of GUS from the TGMV coat protein promoter did not require viral DNA replication, nor was it dependent on expression of AL1, the only viral gene necessary for DNA replication. However, maximal expression was achieved following AL1-mediated replication of DNA A. GUS activity from replicating templates exceeded that from nonreplicating templates by 60- to 90-fold. Expression of the GUS reporter gene from nonreplicating viral DNA templates was similar to GUS expression from the 35S promoter of cauliflower mosaic virus in N. tabacum protoplasts.

DNA methylation inhibits propagation of tomato golden mosaic virus DNA in transfected protoplasts.

The effects of methylation on plant viral DNA replication have been studied in Nicotiana tabacum protoplasts transfected with DNA of the geminivirus tomato golden mosaic virus (TGMV). The transfected cells were also used to determine whether experimentally introduced methylation patterns are maintained in extrachromosomal viral DNA. Replacement of cytosine residues with 5-methylcytosine (m5C) reduced the amount of viral DNA which accumulated in transfected protoplasts. The reduction was observed whether m5C residues were substituted for cytosine residues in vitro in either the viral strand or the complementary strand of double-stranded circular inoculum DNAs containing tandemly repeated copies of the A component of the TGMV genome. Both limited and extensive cytosine methylation of TGMV DNA sequences in vitro was not propagated in progeny viral DNA. The absence of detectable maintenance-type methylation of the transfecting TGMV DNA sequences may be related to the lack of methylation observed in double-stranded TGMV DNA isolated from infected plants.

Genetic analysis of tomato golden mosaic virus: ORF AL2 is required for coat protein accumulation while ORF AL3 is necessary for efficient DNA replication.

Tomato golden mosaic virus (TGMV) is a geminivirus whose genome is divided between two DNA components, designated A and B. The TGMV genome contains six open reading frames (ORFs) which can encode proteins of greater than 10 kDa. We have used a protoplast transfection system to determine the effects of viral proteins, as defined by these ORFs, on the accumulation of viral DNA in infected cells. The accumulation of cost protein was also examined in leaf discs. Our results indicate that mutations in ORFs AR1 and AL2 do not affect viral double-stranded DNA (dsDNA) levels, although AR1 and AL2 mutants accumulate only small amounts of single-stranded viral DNA (ssDNA). In contrast, a large reduction in both ss- and dsDNA levels is observed when a mutation is introduced into ORF AL3. Mutations within either of the two DNA B ORFs do not affect DNA replication. The AL3, BR1, and BL1 mutants are capable of synthesizing coat protein; however, coat protein is not detected in leaf discs inoculated with AR1 or AL2 mutants. Testable models are proposed to explain the influence of AL2 protein on coat protein accumulation and to account for the stimulation of viral DNA synthesis mediated by the AL3 gene product.

Ultrastructural features of egg development in oviparae of the vetch aphid, Megoura viciae buckton.

In the ovaries of the oviparous morph of the aphid, Megoura viciae, resting oocytes are located in the basal region of each germarium. During previtellogenic egg development, electron-dense spheres appear in the ooplasm. During vitellogenesis a brush border develops at the oolemma, and numerous protein and lipid-like spheres accumulate in the egg cytoplasm. Follicle cells are of two morphologically distinct types, termed 'type 1' and 'type 2' follicle cells. Unlike the more numerous 'type 1' cell, 'type 2' cells do not become patent. The acellular tunica propria exterior to follicle cell apices remains intact throughout egg development. During late vitellogenesis symbiont invasion of eggs takes place via 'receptor' cells encircling the pedicel at the posterior egg pole. These cells shrink and/or degenerate to create intercellular spaces that facilitate symbiont transmission. The end of vitellogenesis is marked by vitelline membrane formation and secretion of the chorionic layers, at which time the next egg in the ovariole undergoes final stages of previtellogenic growth and enters vitellogenesis.

Molecular cloning of a recA-like gene of Methylophilus methylotrophus and identification of its product.

A recombinant plasmid, pPF5, has been constructed which contains a 5.5-kb fragment of Methylophilus methylotrophus DNA inserted into pAT153, and which confers resistance to UV and mitomycin C (MC) upon Escherichia coli recA mutants. Hybridisation analysis indicates that sequence homology exists between the cloned DNA and a fragment of E. coli chromosomal DNA that contains the recA gene. Tn1000 insertions have been isolated within pPF5 that inactivate its ability to complement recA mutations, and the site of each insertion has been determined by restriction mapping. A 36-kDa protein is synthesised by pPF5 but not by any of the Tn1000 derivatives, indicating that this protein is the product of the gene responsible for the complementation. Comparison of the size of truncated polypeptides produced by selected pPF5::Tn1000 derivatives with the position of the insertion sites of the transposon, gave the direction of transcription of the M. methylotrophus recA+ gene. SOS proteins are induced in E. coli recA mutants harbouring pPF5 following MC treatment.