Abstract P5-02-03: Evaluating the feasibility of a web-based preference-tolerant randomized trial of risk-based vs. annual breast cancer screening: WISDOM study pilot

Background: The WISDOM Study (Women Informed to Screen Depending on Measures of risk) aims to examine the effectiveness of personalized breast cancer screening and to bring objective recommendations to the current mammography screening debate. The WISDOM Study is a 100,000 woman randomized trial with a preference-tolerant design that will determine if risk-based screening (RBS) vs. annual screening, is as safe, less morbid, enables prevention and is preferred by women. A pilot was conducted to test the logistics of online participation and examine the acceptance of the study design and approach.

Methods: Women were recruited from the UCSF site of the Athena Breast Health Network, a clinical care-research cohort of 110,000 women from the 5 University of California Medical Centers and Sanford Health. The pilot recruited women via email who were 40 -74 years of age with no history of breast cancer and a normal mammogram in the past year. Those interested visited the WISDOM Study website (wisdomstudy.org), signed up, elected randomization or self-selection, provided electronic consent using DocuSign (eConsent), and completed genetic testing (RBS arm). The Breast Cancer Surveillance Consortium (BCSC) model (standard risk factors, ethnicity, and breast density) in addition to genetic testing (9 genes and 75 SNPs) was used to calculate breast cancer risks that informed the start and frequency of screening for women in the RBS arm. BCSC was also used in the annual screening arm but did not inform mammography screening recommendations. The pilot used a mixed method approach (using enrollment data, Exit Survey data, individual interviews and focus groups) to assess enrollment preferences, randomization acceptance and overall study workflow.

Results: The online electronic enrollment process and patient engagement portal was successfully implemented. In total, 639 women were invited, 235 registered (34%), and 171 (27%) consented to the pilot. Of these, 74% (127) elected to be randomized, and 26% chose to self-assign (66% chose annual screening (29)). Mean age was 56 years and the ethnic breakdown of the cohort was: 79% White, 10% Asian, 7% Latino, 3% Black, 1% other. 92% of those in the risk-based arm of the study completed genetic testing and were given results; only one genetic mutation was identified and occurred in CHEK2. Within the RBS arm (78), mammography recommendations were: 61% no further mammography until the age of 50, 22% biennial, 11% annual, and 6% every 6 month alternating MRI and mammogram. Exit Survey data illuminated confusion in study arm names (risk-based vs. annual), randomization acceptance (74%), annual arm preference in the self-selection group (66%), eConsent satisfaction (90%), enrollment process ease of use (88%), and website content, navigation and appearance satisfaction (66%). The pilot concluded in May 2016 to allow for refinements prior to the full trial.

Conclusion: Our pilot demonstrates that the majority of women are willing to be randomized and participate in an online screening study to answer the important question on optimal breast cancer screening. The pilot study results will inform implementation of the 100,000 women WISDOM Study which launches in fall of 2016.

Citation Format: Stover Fiscalini A, Theiner S, Kaplan C, Sarrafan S, Sawyer S, Liang A, Rosenberg-Wohl S, Gordon D, Frick M, Borowsky A, Anton-Culver H, Naeim A, LaCroix A, Cink T, Collaboration Athena Breast Health Network and Advocate Partners, Esserman L, van 't Veer L. Evaluating the feasibility of a web-based preference-tolerant randomized trial of risk-based vs. annual breast cancer screening: WISDOM study pilot [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-02-03.

Understanding Biases in Ribosome Profiling Experiments Reveals Signatures of Translation Dynamics in Yeast

Ribosome profiling produces snapshots of the locations of actively translating ribosomes on messenger RNAs. These snapshots can be used to make inferences about translation dynamics. Recent ribosome profiling studies in yeast, however, have reached contradictory conclusions regarding the average translation rate of each codon. Some experiments have used cycloheximide (CHX) to stabilize ribosomes before measuring their positions, and these studies all counterintuitively report a weak negative correlation between the translation rate of a codon and the abundance of its cognate tRNA. In contrast, some experiments performed without CHX report strong positive correlations. To explain this contradiction, we identify unexpected patterns in ribosome density downstream of each type of codon in experiments that use CHX. These patterns are evidence that elongation continues to occur in the presence of CHX but with dramatically altered codon-specific elongation rates. The measured positions of ribosomes in these experiments therefore do not reflect the amounts of time ribosomes spend at each position in vivo. These results suggest that conclusions from experiments in yeast using CHX may need reexamination. In particular, we show that in all such experiments, codons decoded by less abundant tRNAs were in fact being translated more slowly before the addition of CHX disrupted these dynamics.

Ribosome profiling measures the precise locations of millions of actively translating ribosomes on mRNAs. In theory, the frequency with which ribosomes are observed positioned over each type of codon can be used to quantify the speed with which each codon is translated. In practice, ribosome profiling experiments in yeast that use translation inhibitors to arrest translation before measuring the positions of ribosomes report very different apparent translation speeds for each codon than experiments that do not use inhibitors. To explain this inconsistency, we show that a previously unappreciated mechanism causes experiments using translation inhibitors to not measure ribosomes at each position on mRNAs in proportion to the actual amount of time spent there in vivo. Understanding this mechanism reveals that experiments without inhibitors more accurately measure translation dynamics and provides guidance for the design and interpretation of future ribosome profiling experiments.

Evolutionary origins of the estrogen signaling system: insights from amphioxus

Classically, the estrogen signaling system has two core components: cytochrome P450 aromatase (CYP19), the enzyme complex that catalyzes the rate limiting step in estrogen biosynthesis; and estrogen receptors (ERs), ligand activated transcription factors that interact with the regulatory region of target genes to mediate the biological effects of estrogen. While the importance of estrogens for regulation of reproduction, development and physiology has been well-documented in gnathostome vertebrates, the evolutionary origins of estrogen as a hormone are still unclear. As invertebrates within the phylum Chordata, cephalochordates (e.g., the amphioxus of the genus Branchiostoma) are among the closest invertebrate relatives of the vertebrates and can provide critical insight into the evolution of vertebrate-specific molecules and pathways. To address this question, this paper briefly reviews relevant earlier studies that help to illuminate the history of the aromatase and ER genes, with a particular emphasis on insights from amphioxus and other invertebrates. We then present new analyses of amphioxus aromatase and ER sequence and function, including an in silico model of the amphioxus aromatase protein, and CYP19 gene analysis. CYP19 shares a conserved gene structure with vertebrates (9 coding exons) and moderate sequence conservation (40% amino acid identity with human CYP19). Modeling of the amphioxus aromatase substrate binding site and simulated docking of androstenedione in comparison to the human aromatase shows that the substrate binding site is conserved and predicts that androstenedione could be a substrate for amphioxus CYP19. The amphioxus ER is structurally similar to vertebrate ERs, but differs in sequence and key residues of the ligand binding domain. Consistent with results from other laboratories, amphioxus ER did not bind radiolabeled estradiol, nor did it modulate gene expression on an estrogen-responsive element (ERE) in the presence of estradiol, 4-hydroxytamoxifen, diethylstilbestrol, bisphenol A or genistein. Interestingly, it has been shown that a related gene, the amphioxus "steroid receptor" (SR), can be activated by estrogens and that amphioxus ER can repress this activation. CYP19, ER and SR are all primarily expressed in gonadal tissue, suggesting an ancient paracrine/autocrine signaling role, but it is not yet known how their expression is regulated and, if estrogen is actually synthesized in amphioxus, whether it has a role in mediating any biological effects. Functional studies are clearly needed to link emerging bioinformatics and in vitro molecular biology results with organismal physiology to develop an understanding of the evolution of estrogen signaling. This article is part of a Special Issue entitled 'Marine organisms'.

Maximum geographic range of a mutant allele considered as a subtype of a Brownian branching random field

A rare allelic type is modeled as a field of individuals diffusing independently in d-dimensional space (d = 1,2,...), in which individuals are replaced by random numbers of offspring at a constant rate. In an infinite-allele model with selectively identical alleles, the offspring distribution would have mean 1 - u, in which u is the mutation rate; otherwise mean (1 - u)w, in which w is the relative fitness of the allele. Let p(x) be the probability that some descendent of an individual initially at zero diffuses unilaterally as far as x(d = 1), or else the probability that some descendent of an individual at x diffuses within a > 0 of the origin (d >/= 2). A nonlinear differential equation is found for p(x) that is solvable for d = 1 and related to Emden's equation for d >/= 2. For p(x) >/= 10(-4) and u </= 10(-5), genetic drift is more important than mutation in the behavior of p(x) (d = 1). If u = 0 and w = 1, p(x) approximately C/x(2) as x --> infinity for d </= 3. As a mathematical application, it is shown that if the initial distribution is uniform Poisson, a bounded open set K is visited by individuals in the field at arbitrarily large times if d >/= 2 but not if d = 1.

Sequence analysis and classification of apparent recombinant begomoviruses infecting tomato in the nile and mediterranean basins

ABSTRACT Numerous whitefly-transmitted viral diseases of tomato have emerged in countries around the Nile and Mediterranean Basins the last 20 years. These diseases are caused by monopartite geminiviruses (family Gemini viridae) belonging to the genus Begomovirus that probably resulted from numerous recombination events. The molecular biodiversity of these viruses was investigated to better appreciate the role and importance of recombination and to better clarify the phylogenetic relationships and classification of these viruses. The analysis partitioned the tomato-infecting begomoviruses from this region into two major clades, Tomato yellow leaf curl virus and Tomato yellow leaf curl Sardinia virus. Phylogenetic and pairwise analyses together with an evaluation for gene conversion were performed from which taxonomic classification and virus biodiversity conclusions were drawn. Six recombination hotspots and three homogeneous zones within the genome were identified among the tomatoinfecting isolates and species examined here, suggesting that the recombination events identified were not random occurrences.

Enhancing validity: what counts as an asthma attack?

BACKGROUND

Major epidemiological studies in asthma use the question: "How many attacks of asthma have you had in the last 12 months?" We set out to study what constitutes an asthma attack from the perspective of people with asthma. We also examined concordance between qualitative responses and standard quantitative measures of this question.

METHODS

Individuals aged 18 to 70 years who sought care for asthma at Emergency Departments in an Australian central city, a suburban and a regional hospital were recruited. Sixty two (43 women and 19 men) participants were interviewed in depth. All interviews were taped, transcribed and thematically analyzed. Demographic data and responses to respiratory health data were also collected.

FINDINGS

Widely varying responses to the question, "How many attacks of asthma have you had in the last 12 months?" were found in the quantitative data set. Comparison of quantitative and qualitative data sets showed good agreement between these two responses (intraclass correlation 0.66). People defined asthma attacks as "major" and "minor," as determined by the degree of personal control they were able to exercise. A strongly unifying description of a severe attack was that it was "out of control." Patient's recognized that upper respiratory tract infections commonly triggered major attacks.

INTERPRETATION

A commonly asked question about the number of asthma attacks in the past year needs refinement in order to enhance validity. Asthma action plans should use the words "out of control" when defining a severe attack of asthma.

The use of conventional and complementary treatments for knee osteoarthritis in the community

OBJECTIVES

The aim of the survey was to assess the prevalence of clinically diagnosed knee osteoarthritis (OA) in two general practice populations in the Wessex region (practice A: a deprived urban population and practice B: an affluent rural population) and to assess both conventional and complementary therapy use in these two populations.

METHODS

All patients over 55 yr with a clinical diagnosis of knee OA, as identified from the practice computerized records, were sent a questionnaire about their knee pain and their use of conventional and complementary treatments.

RESULTS

A total of 4566 patients over 55 yr were registered in the two practices. Of these, 828 (18.13%) had a clinical diagnosis of knee OA and 240 (29%) patients were asymptomatic at the time of survey. Physiotherapy was under-utilized with only 13.1% of patients having received either hospital- or GP-based physiotherapy. There was a high prevalence of non-steroidal anti-inflammatory drug (NSAID) use, being significantly more in the affluent population (P < 0.05). In the affluent population there were statistically more social class groups 1-3a; statistically more NSAIDs, glucosamine and chondroitin sulphate were also used. The median amount spent on complementary medicine per month was 5.00 UK pounds, with the affluent population spending significantly more (P < 0.05).

CONCLUSIONS

In this population, physiotherapy is an under-utilized treatment for knee OA, in spite of its recommendation as first-line treatment in all guidelines. Complementary medicines and therapies are commonly used, particularly in affluent populations.

General anaesthesia or conscious sedation for painful procedures in childhood cancer: the family's perspective

BACKGROUND

Until recently, midazolam sedation was routinely used in our institution for bone marrow aspirates and lumbar punctures in children with cancer. It has been perceived by many doctors and nurses as being well tolerated by children and their families.

AIM

To compare the efficacy of inhalational general anaesthesia and midazolam sedation for these procedures.

METHODS

A total of 96 children with neoplastic disorders, who received either inhalational general anaesthesia with sevoflurane, nitrous oxide, and oxygen (GA) or sedation with oral or nasal midazolam (SED) as part of their routine preparation for procedures were studied. The experiences of these children were examined during their current procedure and during their first ever procedure. Main outcome measures were the degree of physical restraint used on the child, and the levels of distress and pain experienced by the child during the current procedure and during the first procedure. The family's preference for future procedures was also determined.

RESULTS

During 102 procedures under GA, restraint was needed on four occasions (4%) when the anaesthetic mask was first applied, minimal pain was reported, and children were reported as distressed about 25% of the time. During 80 SED procedures, restraint was required in 94%, firm restraint was required in 66%, the child could not be restrained in 14%, median pain score was 6 (scale 0 (no pain) to 6 (maximum pain)), and 90% of the parents reported distress in their child. Ninety per cent of families wanted GA for future procedures. Many families reported dissatisfaction with the sedation regime and raised concerns about the restraint used on their child.

CONCLUSIONS

This general anaesthetic regime minimised the need for restraint and was associated with low levels of pain and distress. The sedation regime, by contrast, was much less effective. There was a significant disparity between the perceptions of health professionals and those of families with respect to how children coped with painful procedures.

Molecular diversity of RNA-2 genome segments in pecluviruses causing peanut clump disease in West Africa and India

The complete nucleotide sequence of RNA-2 genome segments of four isolates of Peanut clump virus (PCV) and two isolates of Indian peanut clump virus (IPCV) were determined. Comparisons among the complete RNA-2 sequences of six isolates from this study and two published earlier, revealed a high degree of variability in size (between 4290 and 4652 nucleotides) and nucleotide sequence identities (between 58 % and 79 %). Amino acid sequence alignments of the five open reading frames (ORF) showed that ORF 4, which encodes the second of the triple gene block proteins, is highly conserved (90 to 98 % identical) whereas the protein encoded by ORF 2, whose function is unknown, is less conserved (25 to 60 % identical). The coat protein of the eight isolates showed amino acid identities between 37 % and 89 % and contained several conserved residues. Phylogenetic comparisons, based on complete RNA-2 sequences, revealed that the eight isolates grouped into two distinct clusters with no geographical distinction between PCV and IPCV isolates. Phylogenetic tree topologies for individual ORFs showed an overall similarity with that obtained from entire RNA-2 sequences, although the relative positions of individual isolates vary within each cluster. The results indicate that there is substantial divergence among the RNA-2 genomes of pecluviruses and suggest that different proteins have evolved differently, possibly due to different selection pressures.

Directional selection and the site-frequency spectrum

In this article we explore statistical properties of the maximum-likelihood estimates (MLEs) of the selection and mutation parameters in a Poisson random field population genetics model of directional selection at DNA sites. We derive the asymptotic variances and covariance of the MLEs and explore the power of the likelihood ratio tests (LRT) of neutrality for varying levels of mutation and selection as well as the robustness of the LRT to deviations from the assumption of free recombination among sites. We also discuss the coverage of confidence intervals on the basis of two standard-likelihood methods. We find that the LRT has high power to detect deviations from neutrality and that the maximum-likelihood estimation performs very well when the ancestral states of all mutations in the sample are known. When the ancestral states are not known, the test has high power to detect deviations from neutrality for negative selection but not for positive selection. We also find that the LRT is not robust to deviations from the assumption of independence among sites.

Evaluation of an automated system for the collection of packed RBCs, platelets, and plasma

BACKGROUND

This study evaluated the quality of WBC-reduced platelets, RBCs, and plasma collected on a new system (Trima, Gambro BCT) designed to automate the collection of all blood components. The study also evaluated donor safety and suitability of these components for transfusion.

STUDY DESIGN AND METHODS

In Phase I, the quality of the components collected on the new system was evaluated by standard in vitro and in vivo testing methods. Results were compared to those from control components collected by currently approved standard methods. In Phase II, additional collections were performed to evaluate the acceptability of the new system and the safety of platelets collected.

RESULTS

In vivo 24-hour RBC recovery was 76.8 +/- 3.1 percent for the test RBC units and 77.1 +/- 4.4 percent recovery for whole-blood (control) RBCs. The differences between test and control platelet results in the in vivo and in vitro assays were not clinically significant. Plasma clotting factors and fibrinogen levels met international standards. The system was well accepted by donors, and no major adverse donor reactions were reported for the 68 procedures performed. No problems were reported with transfusing the blood components collected.

CONCLUSION

Blood components collected with the Trima are equivalent to currently available components, and they meet the applicable regulatory standards. This system provides consistent, standardized components with predictable yields. It provides the option of fully automating the collection of all blood components.

Mcm10 and the MCM2-7 complex interact to initiate DNA synthesis and to release replication factors from origins

MCM2-7, a complex of six subunits, is an essential component of the prereplication chromatin that is assembled at Saccharomyces cerevisiae replication origins during G(1) phase. It is also believed to be the processive helicase at growing forks. To elucidate the action of MCM2-7 during the transition from initiation to elongation replication, we have focused our studies on Mcm10, a replication initiation protein that physically interacts with members of the MCM2-7 complex. We show that Mcm10 is a chromatin-associated protein that mediates the association of the MCM2-7 complex with replication origins. Furthermore, diminished interaction between Mcm10 and Mcm7, a subunit of the MCM2-7 complex, by a mutation in either Mcm10 or Mcm7 inhibits replication initiation. Surprisingly, a double mutant containing both the mcm10-1 and mcm7-1 (cdc47-1) alleles restores interaction between Mcm10 and Mcm7 and corrects all of the defects exhibited by each of the single mutants, including the stalling of replication forks at replication origins typically seen in mcm10-1 cells. This mutual compensation of defects between two independently isolated mutations is allele specific. These results suggest that Mcm10, like Mcm7, is a critical component of the prereplication chromatin and that interaction between Mcm10 and Mcm7 is required for proper replication initiation and prompt release of origin-bound factors.

Mcm10 and the MCM2–7 complex interact to initiate DNA synthesis and to release replication factors from origins

MCM2–7, a complex of six subunits, is an essential component of the prereplication chromatin that is assembled at Saccharomyces cerevisiae replication origins during G1 phase. It is also believed to be the processive helicase at growing forks. To elucidate the action of MCM2–7 during the transition from initiation to elongation replication, we have focused our studies on Mcm10, a replication initiation protein that physically interacts with members of the MCM2–7 complex. We show that Mcm10 is a chromatin-associated protein that mediates the association of the MCM2–7 complex with replication origins. Furthermore, diminished interaction between Mcm10 and Mcm7, a subunit of the MCM2–7 complex, by a mutation in either Mcm10 or Mcm7 inhibits replication initiation. Surprisingly, a double mutant containing both the mcm10-1 and mcm7-1(cdc47-1) alleles restores interaction between Mcm10 and Mcm7 and corrects all of the defects exhibited by each of the single mutants, including the stalling of replication forks at replication origins typically seen in mcm10-1 cells. This mutual compensation of defects between two independently isolated mutations is allele specific. These results suggest that Mcm10, like Mcm7, is a critical component of the prereplication chromatin and that interaction between Mcm10 and Mcm7 is required for proper replication initiation and prompt release of origin-bound factors.

Obesity in childhood and adolescence

BACKGROUND

Obesity in childhood and adolescence is increasing in developed countries around the world. Management is often difficult and can be unsuccessful.

OBJECTIVE

The epidemiology, causes and complications of obesity in childhood and adolescence are described, and a general clinical approach to weight management is provided.

DISCUSSION

In general, a comprehensive history and examination can elicit medical causes of obesity. This paper does not seek to expand on medical causes but rather focuses on the clinical issues dealing with management of the overweight child or adolescent. This approach relies on actively engaging the child or young person, as well as involving the entire family in the process. Weight management consists of a combination of healthy eating behaviour and engaging in physical activity.

Attentional function in secondary school students receiving isoniazid prophylaxis for tuberculosis infection

Reports have suggested that isoniazid treatment may be associated with poor concentration and subtle reduction in memory. This study examines attentional function and processing speed in a group of 25 adolescents who received isoniazid prophylaxis for at least 6 months. As adolescents often face major educational assessment milestones, such cognitive side effects may have important implications. Participants were assessed before treatment, 1 month into treatment and at least 1 week after treatment cessation. Measures included the Paced Auditory Serial Addition Test and subtests of the appropriate Wechsler scale sensitive to attention and speed of information processing. Isoniazid does not appear to cause significant adverse effects on attentional function in adolescents.

Possible emergence of new geminiviruses by frequent recombination

Although exchange of genetic information by recombination plays a role in the evolution of viruses, the extent to which it generates diversity is not clear. We analyzed genomes of geminiviruses for recombination using a new statistical procedure developed to detect gene conversions. Geminiviruses (family, Geminiviridae) are a group of plant viruses characterized by a genome of circular single-stranded DNA (approximately 2700 nucleotides in length) encapsidated in twinned quasi-isometric particles. Complete nucleotide sequences of geminiviruses were aligned, and recombination events were detected by searching pairs of viruses for sequences that are significantly more similar than expected based on random distribution of polymorphic sites. The analyses revealed that recombination is very frequent and occurs between species and within and across genera. Tests identified 420 statistically significant recombinant fragments distributed across the genome. The results suggest that recombination is a significant contributor to geminivirus evolution. The high rate of recombination may be contributing to the recent emergence of new geminivirus diseases.

Quality and clinical response to transfusion of prestorage white cell-reduced apheresis platelets prepared by use of an in-line white cell-reduction system

BACKGROUND

This study evaluated the quality and clinical effectiveness of white cell (WBC)-reduced apheresis platelets collected by the use of a new technology, fluidized particle-bed separation.

STUDY DESIGN AND METHODS

In phase 1, six suitable donors underwent two separate plateletpheresis procedures on one occasion, each separated by less than 10 minutes. In random order, a control unit was collected with the COBE Spectra and a test unit with the Spectra Leukocyte-Reduction System (LRS). The quality of apheresis platelet components was assessed by an in vitro test panel, and residual WBCs were counted by Nageotte chamber and flow cytometric methods. For the in vivo studies, the test and control units were randomly labeled with either 51Cr or 111In at the end of storage and transfused simultaneously to the donor. Samples were taken for calculation of platelet survival and recovery. In phase II, 109 thrombocytopenic patients were given platelets collected by use of the Spectra LRS.

RESULTS

Test platelets had significantly fewer residual WBCs (median 7.6 x 10(4)) than control platelets (median 3.9 x 10(5)), with equivalent in vitro function values. Test and control platelets had similar recovery and survival. Transfused platelets collected by use of the LRS achieved a mean 1-hour corrected-count increment of 19.3.

CONCLUSION

The LRS collects platelet components with significantly lower WBC contamination without adverse effects on the function or in vivo survival of the platelets.

A novel approach to monitoring adherence to preventive therapy for tuberculosis in adolescence

OBJECTIVES

To evaluate the usefulness of a microelectronic tablet-dispenser for monitoring adherence to preventive therapy for tuberculosis infection in adolescents.

METHODOLOGY

Twenty-one patients with positive Mantoux tests were treated with isoniazid (INH), dispensed in a microelectronic tablet-dispenser that recorded the date, time and duration that the container was opened. Other measures of adherence included attendance at clinic, patient self-report, tablet count, and measurement of urinary INH metabolites.

RESULTS

The mean adherence rates were: 83% using attendance at clinic, 91% using tablet counts, 79% using urine assays, and 66% using the electronic tablet-dispenser. Self-reporting appeared to over-estimate adherence.

CONCLUSION

Adherence to 6 months of INH calculated using different measures is higher in this study than in previous reports. Microelectronic tablet-dispensers are an effective method to objectively measure adherence on a daily basis. Other measures are less helpful.

Smoking prevention and cessation in adolescents

Tobacco smoking is the most important preventable health risk factor in Australia. It has lost popularity and acceptability in Australia as a result of public health campaigns and their reinforcement through government legislation. The rate of smoking in Australia has gradually declined due to increased cessation in adults. Adolescents, however, are smoking as much as ever. The aim of this paper is to provide family practitioners with practical, simple clinical strategies to reduce teenage smoking.

Arterial heparin deposition: role of diffusion, convection, and extravascular space

Transvascular transport has been studied with atherogenic, tracer, and inert compounds such as low-density lipoprotein, horseradish peroxidase, and albumin, respectively. Few studies used vasoactive compounds, and virtually all studies examined entry from the lumen and not from the perivascular space. We compared several mechanisms that govern arterial heparin deposition after administration to the perivascular and endovascular aspects of the calf carotid artery in vitro and the rabbit iliac artery in vivo. In the absence of transmural hydrostatic pressure gradients, heparin deposition following endovascular administration was unaffected by deendothelialization and was indistinguishable from perivascular delivery. Deposition in the former was enhanced by the addition of a pressure gradient and to a greater extent in denuded arteries, indicating that convection influences transport but is dampened by the endothelium. Neither the endothelium nor the adventitia pose significant resistances to heparin. Deposition in vivo was greater following endovascular hydrogel release than perivascular application from similar devices to native or denuded arteries. The loss of drug to extra-arterial microvessels exceeded the loss of drug to the lumen flow. These findings are essential for describing vascular pharmacokinetics and for implementing local pharmacotherapies.

Introducing an analgesic prescription chart

The report of the working party on pain after surgery states that the 'failure to relieve pain is morally and ethically unacceptable' (Working Party of the Commission on the Provision of Surgical Services, 1990). The report's recommendations include: A patient's pain should be assessed and recorded along with other observations; The level of care and monitoring is appropriate both to the clinical condition of the patient and the technique employed, with training for staff to include programmes for the diagnosis and management of the complications and hazards of particular forms of treatment.

Interferon-gamma protects against herpes simplex virus type 1-mediated neuronal death

Host inflammatory mediators, such as interferons, play a protective role in infection, but the mechanism is undefined and may differ between tissue compartments. To determine whether interferon-gamma (IFN-gamma) elicitation prevents destructive encephalitis in herpes simplex virus type 1 (HSV-1) infection of the central nervous system, IFN-gamma-knockout (GKO) mice were challenged intravitreally with HSV-1 strain F, inciting infection of the eyes and the brain. Indeed, the GKO mice showed encephalitis with ataxia, whereas nontransgenic controls remained asymptomatic. Morphology and digoxigenin labeling of DNA fragments revealed increased apoptosis in the brains of GKO mice compared with controls, although viral replication was not influenced at early stages of infection. Greater numbers of apoptotic cells in the brains of GKO mice correlated with neurological symptoms, as well as lower expression of the protective protooncogene bcl-2. Thus, IFN-gamma inhibits apoptosis, affording neuronal protection from destructive encephalitis during viral infection of the central nervous system.

Effects of short and long term ethanol on the activation of signal transducer and activator transcription factor 3 in normal and regenerating liver

Interleukin-6 (IL-6) induced activation of Signal Transducer and Activator Transcription Factor 3 (Stat3) is a critical step in liver regeneration. Chronic ethanol consumption is known to increase the plasma concentration of IL-6, yet the ability of the liver to regenerate and the regenerative induction of several IL-6 initiated events are impaired in chronic alcoholic liver disease. We hypothesized that chronic ethanol consumption inhibits IL-6 dependent signal transduction. To test this hypothesis, the effect of ethanol on the Stat3 signal transduction pathway was studied in the adult rat liver. In vitro treatment of freshly isolated normal adult rat hepatocytes with 50-100 mM ethanol for 30 min blocked IL-6-induced Stat3 activation. Long-term ethanol intake in vivo significantly attenuated the activation of Stat3 induced either in vivo by partial hepatectomy or in vitro by IL-6. In contrast, short-term ethanol consumption enhanced the regenerative induction of Stat3 but inhibited IL-6 induced Stat3 activation. These data suggest that the inhibition of liver regeneration by chronic ethanol consumption is, at least in part, mediated by modulating the activation of Stat3.

The expression of p-selectin during collection, processing, and storage of platelet concentrates: relationship to loss of in vivo viability

BACKGROUND

Recent studies suggested that platelet activation with surface expression of p-selectin on stored platelets may be related to a loss of viability. At present, there has been no thorough investigation of the extent or significance of p-selectin expression during the collection, processing, and storage of platelet concentrates (PCs) under various conditions.

STUDY DESIGN AND METHODS

Platelet surface expression of p-selectin (CD62) was determined on fixed platelet samples using fluorescein-conjugated monoclonal antibodies. Platelet viability was assessed by autologous transfusion of platelets stored for 5 days and labeled with either 51Cr or 111in.

RESULTS

Little (2-10%) platelet expression of p-selectin was found in whole blood and platelet-rich-plasma preparations, whereas PCs showed a substantial increase in p-selectin expression to levels of 20 to 30 percent. Both fresh PCs and those stored for 5 days, obtained with one cell separator (MCS, Haemonetics) showed substantially lower levels of p-selectin expression than PCs from two other cell separators (Spectra, COBE, and CS-3000 with TNX-6, Baxter Healthcare). Exposure of platelets to EDTA, cold, or a pH below 6.2, conditions that are known to result in the loss of viability upon transfusion, produced substantial and irreversible p-selectin expression. PCs with a pH of 6.2 to 6.8 (conditions in which no loss of viability has been demonstrated) also showed pronounced p-selectin expression, which returned to control values after incubation at 37 degrees C in plasma at pH 7.0 to 7.2. With storage under current conditions the in vivo studies (n = 61) demonstrated a rather poor correlation between p-selectin expression and the percentage of recovery (r = -0.25) but a somewhat better correlation with survival (r = -0.42). Better correlations were observed with the extent of shape change, lactate, and hypotonic shock response.

CONCLUSION

These studies show that p-selectin expression on the platelet surface is a predictor of platelet viability, although the extent of shape change and the hypotonic shock response may be more sensitive.

Studies on platelets exposed to or stored at temperatures below 20 degrees C or above 24 degrees C

BACKGROUND

Platelet concentrates (PCs) may be subjected to temperatures outside 20 to 22 degrees C during shipping or storage, which may have an adverse effect on platelet quality.

STUDY DESIGN AND METHODS

These studies systematically evaluated the effect of short-term exposure (< or = 24 hours) of platelets to temperatures above 22 degrees or below 20 degrees C as part of standard 5-day PC storage at 22 degrees C, as well as the effect of long-term storage (5 days) at 24 and 26 degrees C. For the short-term exposure studies, up to 6 units of Day 1 standard PCs were mixed, split, and returned to the containers. Test units were then stored without agitation in an incubator at a specific temperature (4, 12, 16, or 18 degrees C) for various times up to 24 hours, after which they were stored with agitation at 22 degrees C. One unit acted as control and was stored at 20 to 22 degrees C throughout the 5-day storage period. Loss of platelet discoid shape was determined photometrically by the extent of shape change assay, by an increase in apparent platelet size by morphologic evaluation, and by swirling.

RESULTS

A gradual loss of platelet discoid shape occurred at temperatures below 20 degrees C. For similar periods, a greater difference between test and control PCs was observed in units held at 4 degrees C than in those held at 16 degrees C. The data were fitted to an equation to relate platelet discoid shape (% of control) to exposure temperature and time. Assuming that a 20-percent decrease or more in the extent of shape change assay represents a significant loss in platelet viability, the equation predicts that such a loss occurs when the platelets are exposed to 16 degrees C for > or = 16 hours, to 12 degrees C for > or = 10 hours, or to 4 degrees C for > or = 6 hours, whereas exposure to 18 degrees C for < or = 24 hours has no significant effect. Storage for 5 days at temperatures < or = 26 degrees C was not associated with any significant reduction in platelet discoid shape or other measures of platelet quality.

CONCLUSION

There was a gradual loss of platelet discoid shape at exposure temperatures < 20 degrees C, which worsened as temperatures decreased and exposure times increased to 24 hours. This relationship can be described in an equation that could be used as a guideline for allowable exposure conditions.