Association of SV40 with human tumours

SV40 was discovered as a contaminant of poliovirus vaccines that were inadvertently administered to millions of people in Europe and the United States between 1955 and 1963. Shortly afterwards, SV40 was proven to be oncogenic in rodents and capable of transforming human and animal cells in vitro. The possibility that SV40 might cause tumours in humans thus became a subject of scientific and public interest and scrutiny. However, largely due to a lack of significant epidemiological evidence, interest in assessing SV40's potential carcinogenic role in humans diminished. Recently, many laboratories have reported the presence of SV40-like DNA in a high proportion of human mesotheliomas, ependymomas and osteosarcoma (the three main types of tumours caused by virus in hamsters), renewing the question whether SV40 might be a human tumour virus. Molecular data from these studies are reviewed to re-evaluate the potential role of SV40 as a human carcinogen.

Randomized controlled trial to assess the effectiveness of a videotape about radiotherapy

In a randomized controlled trial, the additional provision of information on videotape was no more effective than written information alone in reducing pre-treatment worry about radiotherapy. Images of surviving cancer patients, however, may provide further reassurance to patients once therapy is completed.

The effect of an intrauterine application of two percent lignocaine gel on pain perception during Vabra endometrial sampling: a randomised double-blind, placebo-controlled trial

OBJECTIVE

To determine whether two percent lignocaine gel can reduce the perception of pain during Vabra endometrial aspiration.

DESIGN

Randomised, double-blind placebo-controlled trial.

SETTING

Women's Health Directorate, Warrington Hospital NHS Trust.

POPULATION

Women were referred to the endometrial sampling clinic for the investigation of pre and postmenopausal vaginal bleeding.

METHODS

Randomisation to either pre-sampling intrauterine two percent lignocaine gel or an inert gel. Patients, recruiters and assessors were blinded to the gel used.

MAIN OUTCOME MEASURES

The difference between the study groups in the proportion of women who, after Vabra sampling, recorded a pain score of > or = 6 out of 10 on a visual analogue scale.

RESULTS

Three hundred and eight women were randomised, 284 (92%) completed a pain scale before and immediately after the procedure. After the procedure, 84 women (30%) recorded a pain score of > or = 6, 38 (26%) received anaesthetic and 46 (33%) an inert gel. The difference in the proportion of women recording a pain score of 6 or above between the two study groups was not significant (relative risk (RR) for the anaesthetic gel = 0.79 95% CI, 0.55, 1.14).

CONCLUSIONS

Intrauterine application of 2% lignocaine gel did not significantly reduce the frequency with which women experienced unacceptable levels of pain or anxiety during endometrial aspiration compared with placebo.

Do women have equitable access to quality breast prosthesis services?

Although up to 90% of women who have had a mastectomy use breast prostheses, significant gaps exist around current breast prosthesis services for Australian women. These gaps include the timeliness and quality of information provision, the disparity in financial assistance, and the lack of knowledge regarding the determinants of what constitutes a "quality" breast prosthesis. Revised policy initiatives are central to addressing these gaps to ensure equitable access to quality breast prosthesis services.

Evolution and origins of tobamoviruses

More than a dozen tobamoviruses are known. In nature, each species probably survives by moving between several closely related host species. Each infected plant contains a population of variants, but in most host populations the tobamovirus population is stable. The phylogenetic relationships of tobamovirus species broadly correlate with those of their angiosperm hosts. The simplest explanation for this correlation is that they have coevolved with the angiosperms, and hence, like them, are about 120-140 million years old. Gene sequence differences between species also indicate that the tobamoviruses are an ancient genus. Their gene sequences, and the protein motifs they encode, link them to tobraviruses, hordeiviruses and soil-borne wheat mosaic virus, more distantly to the tricornaviruses, and even to hepatitis virus E and other furoviruses, rubiviruses and alphaviruses. Their progenitors may have been associated with charophycean algae, and perhaps also plasmodiophoromycete fungi.

Should smoking cessation cost a packet? A pilot randomized controlled trial of the cost-effectiveness of distributing nicotine therapy free of charge

This pilot study suggests that changes in prescribing policy for nicotine replacement patches should be made only when evidence of cost-effectiveness can be adduced from a randomized controlled trial.

Mineral fibre analysis and routes of exposure to asbestos in the development of mesothelioma in an English region

OBJECTIVES

To compare the concentrations of inorganic fibres in the lungs in cases of mesothelioma and controls: to determine whether concentrations of retained asbestos fibres differ with the different exposures identified from interview; and to investigate the existence of a cut off point in concentrations of asbestos fibres that indicates occupational exposure.

METHODS

Case-control study; 147 confirmed cases of mesothelioma and 122 controls identified from deaths occurring in four districts of Yorkshire between 1979 and 1991. Surviving relatives were interviewed to determine lifetime exposure history to asbestos. Mineral fibre analysis was carried out on lung tissue from postmortem examinations.

RESULTS

Odds on high concentrations of retained asbestos fibres were greater in cases than controls. After excluding subjects with occupational and paraoccupational exposure, the odds on high concentrations were still greater in cases than controls, but only significantly so for amphiboles. There was only a weak relation between probability of occupational exposure to asbestos and concentrations of retained asbestos fibres, and no significant difference in fibre concentrations was found between subjects who had been exposed to asbestos through different routes: these comparisons were only based on small groups. There was considerable overlap in concentrations of retained asbestos fibres between cases and controls with and without histories of occupational exposure.

CONCLUSIONS

The study has confirmed previous results of higher concentrations of asbestos fibres in cases than controls, and has shown that this is still found in subjects with little evidence of occupational and para-occupational exposure. The overlap in concentrations of retained asbestos for different groups of subjects did not suggest a clear cut of value.

The GPRIME package: computer programs for identifying the best regions of aligned genes to target in nucleic acid hybridisation-based diagnostic tests, and their use with plant viruses

The GPRIME (Group PRIMEr design) programs examine aligned sets of gene sequences to discover homologous regions to be targeted in diagnostic tests. The core program moves a 'window' over the aligned sequences and calculates, at each window position, a 'redundancy value', namely the number of sequences that would represent all permutations of the variable sequence positions within that window. Regions with minimal redundancy values may then be targeted in diagnostic tests based on oligonucleotide hybridisation. The likely specificity of tests targeting such regions can be assessed by searching the international databases with those regions using FASTA. The GPRIME programs, which include programs for designing primers to distinguish between two sub-sets of a group of aligned sequences, can be obtained from http://life.anu.edu.au/software.html. We have used GPRIME to design redundant primers for RT-PCR tests to detect all potexviruses and tobamoviruses, and then used these, together with a previously reported pair of primers for the Potyviridae, to screen some Australian orchid collections. Two orchid viruses previously reported from Australia were found; cymbidium mosaic potexvirus was common, but odontoglossum ringspot tobamovirus was not. In addition the recently described ceratobium mosaic potyvirus was found to be common, and three other novel potyviruses were also found.

Guidelines for mineral fibre analyses in biological samples: report of the ERS Working Group. European Respiratory Society

Microscopic techniques for analysing asbestos fibres in lung tissue and bronchoalveolar lavage have provided major information in the understanding of asbestos-related diseases. These analyses are increasingly applied for clinical work and medicolegal problems. Differences in sampling, preparation and counting techniques, definitions of reference populations and expression of results have caused major difficulties in comparing results from different laboratories. Therefore it appeared necessary to set a goal to harmonize these analyses between the European laboratories active in this field. This article summarizes the work of a European Respiratory Society working group with participation from nine European laboratories. The five main issues touched upon are: 1) definitions of control populations and reference levels; 2) sampling, preparation and analytical techniques; 3) asbestos fibres in lung tissues in different pathologies; 4) asbestos bodies in lung tissue, bronchoalveolar lavage and sputum; and 5) basis for the interpretation of fibres and asbestos bodies in biological samples. These guidelines indicate the crucial importance of several factors for the interpretation of the results; namely, adequate sampling, comparable analytical procedures and expression of the results, the use of well-defined reference populations, and a comprehensive understanding of the factors affecting the fibre retention and the dose-responses associated with the different asbestos-related diseases.

Turnip yellow mosaic virus isolates with experimentally produced recombinant virion proteins

The consensus secondary structure of the virion proteins (VPs) of tymoviruses was predicted from their amino acid sequences using a combination of computer methods: profile alignment, hydrophobicity moment and 'PredictProtein'. All methods predicted that they were eight-stranded anti-parallel beta-barrels with two alpha-helical regions. The predicted structure was used to design recombinants of turnip yellow mosaic virus (TYMV) in which selected parts of its VP were replaced with homologous regions of belladonna mottle virus (BeMV) in a cDNA clone encoding the genome of TYMV. Six of ten such recombinants were fully viable and most gave symptoms in Chinese cabbage indistinguishable from those of TYMV, although they did not always infect plants systemically and none infected hosts of BeMV or of other tymoviruses. A TYMV recombinant with the N-terminal part of its VP replaced with the E71 epitope of Plasmodium falciparum was also viable, but others with the same region replaced with the V3 region of the lentivirus human immunodeficiency virus type 1 were not. Epitope analysis of antisera prepared against the virions of parental TYMV and some of the recombinants showed that, although the N terminus of the VP is immunogenically dominant, it is not exposed at the surface of the virion, a finding confirmed by comparing the electrophoretic mobilities of the virions. The recently published structure of the TYMV VP determined by X-ray crystallography confirms the accuracy of the predicted secondary structure of the VP, and hence the utility of the methods used.

Effect of Shear on the Strength of Polymer-Induced Flocs

Micromechanics was used to show that the rupture strength of polymer-induced flocs varied with the hydrodynamic conditions at which the flocs were formed. A maximum floc strength at an intermediate shear rate was observed. The overall performance of the polymeric flocculants, as determined by two independent methods, showed that the conditions for optimal flocculation did not coincide with those for maximum floc strength. The amount of flocculation was explained in terms of the competing effects of the particle collision frequency and the destructive hydrodynamic forces. The contributing forces to the floc strength are, however, more likely to be densification of the floc by shear and the weakening of reattachment strengths. The evidence presented here may be useful for explaining flocculation data that depart from the constant yield stress theory. Thus, the notion of the floc strength varying with shear rate may offer an alternative to multilevel floc structure models in the description of flocculation kinetics. Copyright 1997 Academic Press. Copyright 1997Academic Press

Completeness of reporting on prognostic factors for breast cancer: a regional survey

BACKGROUND

Effective management of breast cancer is dependent on adequate pathological reporting of the surgical specimen.

OBJECTIVE

To describe the frequency with which histopathological features of known prognostic importance are routinely recorded.

STUDY POPULATION

885 cases of invasive breast cancer diagnosed in NHS laboratories in Lancashire and Greater Manchester.

METHODS

Pathology reports were reviewed for details for tumour histological type, size, and grade, the presence or absence of tumour in blood or lymphatic vascular channels, and a comment on the proximity of tumour to the lines of surgical excision. Laboratories were categorised according to their throughput of cases of breast cancer, involvement in the breast screening programme, and whether they were attached to a teaching hospital.

RESULTS

Histological type, tumour size, presence or absence of tumour in vascular channels, and adequacy of excision were recorded for 843 (95%), 803 (91%), 436 (49%), and 761 (86%) cases, respectively. Non-screening and low throughput laboratories were significantly less likely to record certain histopathological features. No significant differences were observed between teaching and non-teaching hospitals.

CONCLUSIONS

The substantial interlaboratory variation in the histopathological reporting of breast cancers can, in part, be related to throughput of cases and involvement in the breast screening programme.

A primer pair for amplifying part of the genome of all potyvirids by RT-PCR

Sequence analysis was used to design a pair of degenerate oligonucleotide primers that amplified a 1.6-2.1 kbp fragment from the 3' end of the genome (virion protein gene and part of the NIb gene) of 17 species of the Potyviridae ('potyvirids'); 11 potyviruses, 2 bymoviruses, 2 macluraviruses, an ipomovirus and a rymovirus. The 'potyvirid primer 1' hybridizes to the 3' terminal poly-A region of the genome, and 'potyvirid primer 2' to the genomic region encoding the-GNNSGQ-motif of the NIb protein. Database searches showed that the potyvirid 2 primer is specific for potyvirids. Associated analyses indicated that the published amino acid sequence of part of the wheat streak mosaic rymovirus NIb protein is probably incorrect in part.

Calculations to determine sample size

Evidence-based care is currently being promoted in the NHS. The implications of this strategy are that nursing practice should be based on evidence rather than opinion or tradition. It is generally accepted that the strongest evidence is provided by a randomised controlled trial. In a randomised controlled trial two groups are involved, one of which receives a new treatment and one of which, the control group, receives a standard or alternative treatment. Ideally, tables of random numbers are used to allocate individual patients to the new treatment and the alternative treatment. In this context, treatment may include not only medication but also an educational or other therapeutic intervention. 'The method is thus widely applicable to nursing research.

Does additional lubrication reduce condom failure?

It has been suggested that using additional spermicide with condoms provides added contraceptive effect and protection from infection, and that water-based lubricants may lower condom breakage rates. This questionnaire-based study investigated the use of additional lubrication with condoms amongst 525 female students presenting for post-coital contraception, and the current and past experience of condom and additional lubrication use amongst 481 controls attending the same health centre. Of those requesting post-coital contraception, 83% claimed condom failure as the cause, with 66% of the control group having also experienced condom failure at some time. Use of additional water-based lubrication was significantly associated with lower condom failure rates (odds ratio 8.88, 95% C.I.: 3.79, 20.8). Gender, regularity of use of condoms and using oil-based lubricants were not associated with higher failure rates. Additional lubricant use was not significantly associated with increased condom slippage.

Replication slippage in the evolution of potyviruses

Recently published evidence for sequence repetition in potyvirus genomes prompted us to analyse the published complete genome sequences and coat protein gene sequences of viruses of this family for evidence of replication slippage. Five of nine complete genomic sequences and 17 of 32 coat protein genes had significant sequence repetitions. Most of these were in coat protein genes, although the 5' region of the turnip mosaic virus genome also showed evidence of slippage. The results suggest that replication slippage may be involved in the evolution of viruses, as well as prokaryotes and eukaryotes, and that slippage can occur in both RNA and DNA when it is being replicated.

DIPLOMO: the tool for a new type of evolutionary analysis

A package of computer programs called DIPLOMO (DIstance PLOt MOnitor) has been developed for making pairwise comparisons of different estimates of the distances between a set of taxa by plotting them against each other in a simple scatter plot. Taxa with similar relative distance characteristics are thereby grouped graphically. Groupings of different taxa may be directly identified, and the distance characteristics of chosen groups visualised and compared using devices to give them different colours or symbols. The program is particularly useful for detecting and analysing subtle trends in gene sequence evolution. This is done by comparing different components of change, for example synonymous versus non-synonymous nucleotide changes, transversions versus transitions and changes in different genes of the same set of taxa, etc. The program has a wide range of other uses, for example comparing different methods of sequence analysis, assessing which components of genetic change correlate best with phenotypic change or with geographical separation. This paper describes the DIPLOMO package, and illustrates typical DIPLOMO analyses using lentivirus gene sequence data.

Sex- and age-related changes in the biophysical properties of cuticular lipids of the housefly, Musca domestica

We examined the biophysical properties of cuticular lipids isolated from the housefly, Musca domestica. Melting temperatures (Tm) of surface lipids isolated from female houseflies decreased from 39.3 degrees C to 35.3 degrees C as the females attained sexual maturity and produced sex pheromone, whereas those prepared from males did not change with age. Lipids melted over a 10-25 degrees C temperature range, and their physical properties were a complex function of the properties of the component lipids. The Tm of total cuticular lipids was slightly below that of cuticular hydrocarbons (HC), the predominant lipid fraction. Hydrocarbons were further fractionated into saturated, unsaturated, and methyl-branched components. The order of decreasing Tm was total alkanes > total HCs > methyl-branched alkanes > alkenes. For 1-day-old flies, measured TmS of hydrocarbons were 1.3-5.5 degrees C lower than TmS calculated from a weighted average of TmS for saturated and unsaturated components. For 4-day-old flies, calculated TmS underestimated Tm by 11-14 degrees C.

Spontaneous ovulatory cycle donor insemination programme: prognostic indicators of a successful pregnancy

The effects of female and male infertility factors as well as the insemination regime on the outcome of donor insemination (DI) during 1001 spontaneous ovulatory cycles were assessed. Overall, the average monthly fecundability was 4.4% and the cumulative conception rate after nine cycles was 45%. Female DI recipients' age, nulligravidity or the presence of other infertility factors were associated with a significantly lower pregnancy rate. DI recipients of azoospermic partners had a significantly higher pregnancy rate. The likelihood of a successful pregnancy was higher when more frequent (> or = 1) inseminations were used or in association with higher cervical score and larger follicle diameter at the time of insemination. We suggest that female recipients of DI should be fully investigated before commencing DI treatment. Early resort to other methods of assisted reproduction should be considered in DI recipients aged > or = 35 years, or in younger women if they fail to conceive after nine cycles of DI. More frequent and better timing of inseminations is expected to improve the fecundability rate during spontaneous ovulatory DI cycles.

Coping with domestic violence in pregnancy

This article defines the term domestic violence, outlines its prevalence, and indicates a link between domestic violence and pregnancy outcomes. A need for the identification and development of intervention strategies by UK midwives is proposed and some consideration and concerns regarding their implementation are expressed.