Temporary increase in circulating replication-competent latent HIV-infected resting CD4+ T cells after switch to an integrase inhibitor based antiretroviral regimen

BACKGROUND

The principal barrier to an HIV cure is the presence of the latent viral reservoir (LVR), which has been understudied in African populations. From 2018 to 2019, Uganda instituted a nationwide rollout of ART consisting of Dolutegravir (DTG) with two NRTI, which replaced the previous regimen of one NNRTI and the same two NRTI.

METHODS

Changes in the inducible replication-competent LVR (RC-LVR) of ART-suppressed Ugandans with HIV (n = 88) from 2015 to 2020 were examined using the quantitative viral outgrowth assay. Outgrowth viruses were examined for viral evolution. Changes in the RC-LVR were analyzed using three versions of a Bayesian model that estimated the decay rate over time as a single, linear rate (model A), or allowing for a change at time of DTG initiation (model B&C).

FINDINGS

Model A estimated the slope of RC-LVR change as a non-significant positive increase, which was due to a temporary spike in the RC-LVR that occurred 0-12 months post-DTG initiation (p < 0.005). This was confirmed with models B and C; for instance, model B estimated a significant decay pre-DTG initiation with a half-life of 6.9 years, and an ∼1.7-fold increase in the size of the RC-LVR post-DTG initiation. There was no evidence of viral failure or consistent evolution in the cohort.

INTERPRETATION

These data suggest that the change from NNRTI- to DTG-based ART is associated with a significant temporary increase in the circulating RC-LVR.

FUNDING

Supported by the NIH (grant 1-UM1AI164565); Gilead HIV Cure Grants Program (90072171); Canadian Institutes of Health Research (PJT-155990); and Ontario Genomics-Canadian Statistical Sciences Institute.

High level of HIV viral suppression in a cross-sectional study of Ugandan men with urethritis and bacterial STI

BACKGROUND

Urethritis associated with non-viral sexually transmitted infections (STI) increases the risk of HIV acquisition and transmission in those living with HIV (LWH) without viral load suppression (VLS). Compared to women, men typically have lower rates of HIV VLS. We assessed the prevalence of VLS and drug resistance mutations in men LWH and urethral discharge syndrome (UDS) in Kampala, Uganda.

METHODS

Men with UDS were recruited in Kampala October 2019-November 2020. Medical, demographic, and behavioural data were collected with biological samples. All reactive HIV results (rapid, sequential algorithm) underwent confirmatory HIV antibody- and HIV incidence-testing, and viral load (VL) measurement. The pol and gp41 regions were sequenced on samples with VLs >1000 cpm, phylogenetic trees were generated, and resistance mutations were investigated.

RESULTS

50 of 250 participants (20%) had reactive HIV rapid tests and 48/50 (96%) were aware of their HIV status and using antiretroviral therapy (ART). The median age was 38 years (IQR 32-45), 27/50 (54%) had engaged in transactional sex, and 30/50 (60%) reported alcohol before sex. VLS was present in 46/50 (92%). There were no major resistance mutations present in any samples analyzed.

CONCLUSIONS

The prevalence of HIV and VLS was greater in these men than in the general Ugandan adult population. Most men LWH were on ART and thus less likely to transmit HIV despite demonstrating sexual behaviours associated with high-risk of STIs. These data emphasize that high levels of ART coverage and VLS are achievable among men with UDS in urban Kampala.

Dating reservoir formation in virologically suppressed people living with HIV-1 in Rakai, Uganda

The timing of the establishment of the HIV latent viral reservoir (LVR) is of particular interest, as there is evidence that proviruses are preferentially archived at the time of antiretroviral therapy (ART) initiation. Quantitative viral outgrowth assays (QVOAs) were performed using Peripheral Blood Mononuclear Cells (PBMC) collected from Ugandans living with HIV who were virally suppressed on ART for >1 year, had known seroconversion windows, and at least two archived ART-naïve plasma samples. QVOA outgrowth populations and pre-ART plasma samples were deep sequenced for the pol and gp41 genes. The bayroot program was used to estimate the date that each outgrowth virus was incorporated into the reservoir. Bayroot was also applied to previously published data from a South African cohort. In the Ugandan cohort (n = 11), 87.9 per cent pre-ART and 56.3 per cent viral outgrowth sequences were unique. Integration dates were estimated to be relatively evenly distributed throughout viremia in 9/11 participants. In contrast, sequences from the South African cohort (n = 9) were more commonly estimated to have entered the LVR close to ART initiation, as previously reported. Timing of LVR establishment is variable between populations and potentially viral subtypes, which could limit the effectiveness of interventions that target the LVR only at ART initiation.

Temporary increase in circulating replication-competent latent HIV-infected resting CD4+ T cells after switch to an integrase inhibitor based antiretroviral regimen

The principal barrier to an HIV cure is the presence of a latent viral reservoir (LVR) made up primarily of latently infected resting CD4+ (rCD4) T-cells. Studies in the United States have shown that the LVR decays slowly (half-life=3.8 years), but this rate in African populations has been understudied. This study examined longitudinal changes in the inducible replication competent LVR (RC-LVR) of ART-suppressed Ugandans living with HIV (n=88) from 2015-2020 using the quantitative viral outgrowth assay, which measures infectious units per million (IUPM) rCD4 T-cells. In addition, outgrowth viruses were examined with site-directed next-generation sequencing to assess for possible ongoing viral evolution. During the study period (2018-19), Uganda instituted a nationwide rollout of first-line ART consisting of Dolutegravir (DTG) with two NRTI, which replaced the previous regimen that consisted of one NNRTI and the same two NRTI. Changes in the RC-LVR were analyzed using two versions of a novel Bayesian model that estimated the decay rate over time on ART as a single, linear rate (model A) or allowing for an inflection at time of DTG initiation (model B). Model A estimated the population-level slope of RC-LVR change as a non-significant positive increase. This positive slope was due to a temporary increase in the RC-LVR that occurred 0-12 months post-DTG initiation (p<0.0001). This was confirmed with model B, which estimated a significant decay pre-DTG initiation with a half-life of 7.7 years, but a significant positive slope post-DTG initiation leading to a transient estimated doubling-time of 8.1 years. There was no evidence of viral failure in the cohort, or consistent evolution in the outgrowth sequences associated with DTG initiation. These data suggest that either the initiation of DTG, or cessation of NNRTI use, is associated with a significant temporary increase in the circulating RC-LVR.

Pembrolizumab monotherapy versus chemotherapy in platinum-pretreated, recurrent or metastatic nasopharyngeal cancer (KEYNOTE-122): an open-label, randomized, phase III trial

BACKGROUND

Pembrolizumab previously demonstrated robust antitumor activity and manageable safety in a phase Ib study of patients with heavily pretreated, programmed death ligand 1 (PD-L1)-positive, recurrent or metastatic nasopharyngeal carcinoma (NPC). The phase III KEYNOTE-122 study was conducted to further evaluate pembrolizumab versus chemotherapy in patients with platinum-pretreated, recurrent and/or metastatic NPC. Final analysis results are presented.

PATIENTS AND METHODS

KEYNOTE-122 was an open-label, randomized study conducted at 29 sites, globally. Participants with platinum-pretreated recurrent and/or metastatic NPC were randomly assigned (1 : 1) to pembrolizumab or chemotherapy with capecitabine, gemcitabine, or docetaxel. Randomization was stratified by liver metastasis (present versus absent). The primary endpoint was overall survival (OS), analyzed in the intention-to-treat population using the stratified log-rank test (superiority threshold, one-sided P = 0.0187). Safety was assessed in the as-treated population.

RESULTS

Between 5 May 2016 and 28 May 2018, 233 participants were randomly assigned to treatment (pembrolizumab, n = 117; chemotherapy, n = 116); Most participants (86.7%) received study treatment in the second-line or later setting. Median time from randomization to data cut-off (30 November 2020) was 45.1 months (interquartile range, 39.0-48.8 months). Median OS was 17.2 months [95% confidence interval (CI) 11.7-22.9 months] with pembrolizumab and 15.3 months (95% CI 10.9-18.1 months) with chemotherapy [hazard ratio, 0.90 (95% CI 0.67-1.19; P = 0.2262)]. Grade 3-5 treatment-related adverse events occurred in 12 of 116 participants (10.3%) with pembrolizumab and 49 of 112 participants (43.8%) with chemotherapy. Three treatment-related deaths occurred: 1 participant (0.9%) with pembrolizumab (pneumonitis) and 2 (1.8%) with chemotherapy (pneumonia, intracranial hemorrhage).

CONCLUSION

Pembrolizumab did not significantly improve OS compared with chemotherapy in participants with platinum-pretreated recurrent and/or metastatic NPC but did have manageable safety and a lower incidence of treatment-related adverse events.

Genomic and phenotypic analyses suggest moderate fitness differences among Zika virus lineages

RNA viruses have short generation times and high mutation rates, allowing them to undergo rapid molecular evolution during epidemics. However, the extent of RNA virus phenotypic evolution within epidemics and the resulting effects on fitness and virulence remain mostly unknown. Here, we screened the 2015-2016 Zika epidemic in the Americas for lineage-specific fitness differences. We engineered a library of recombinant viruses representing twelve major Zika virus lineages and used them to measure replicative fitness within disease-relevant human primary cells and live mosquitoes. We found that two of these lineages conferred significant in vitro replicative fitness changes among human primary cells, but we did not find fitness changes in Aedes aegypti mosquitoes. Additionally, we found evidence for elevated levels of positive selection among five amino acid sites that define major Zika virus lineages. While our work suggests that Zika virus may have acquired several phenotypic changes during a short time scale, these changes were relatively moderate and do not appear to have enhanced transmission during the epidemic.

Higher Proinflammatory Cytokines Are Associated With Increased Antibody Titer After a Third Dose of SARS-CoV-2 Vaccine in Solid Organ Transplant Recipients

BACKGROUND

Solid organ transplant recipients (SOTRs) are at increased risk for severe COVID-19 and exhibit lower antibody responses to SARS-CoV-2 vaccines. This study aimed to determine if prevaccination cytokine levels are associated with antibody response to SARS-CoV-2 vaccination.

METHODS

A cross-sectional study was performed among 58 SOTRs before and after two-dose mRNA vaccine series, 35 additional SOTRs before and after a third vaccine dose, and comparison to 16 healthy controls (HCs). Antispike antibody was assessed using the IgG Euroimmun ELISA. Electrochemiluminescence detection-based multiplexed sandwich immunoassays (Meso Scale Diagnostics) were used to quantify plasma cytokine and chemokine concentrations (n = 20 analytes) and compare concentrations between SOTRs and HCs, stratified by ultimate antibody response to the vaccine using Wilcoxon-rank-sum test with false discovery rates computed to correct for multiple comparisons.

RESULTS

In the study population, 100% of HCs, 59% of SOTRs after 2 doses and 63% of SOTRs after 3 doses had a detectable antibody response. Multiple baseline cytokines were elevated in SOTRs versus HCs. There was no significant difference in baseline cytokine levels between SOTRs with high versus low-titer antibodies after 2 doses of vaccine. However, as compared with poor antibody responders, SOTRs who went on to develop a high-titer antibody response to a third dose of vaccine had significantly higher prethird dose levels of several innate immune cytokines including IL-17, IL-2Ra, IL-6, IP-10, MIP-1α, and TNF-α (false discovery rates < 0.05).

CONCLUSIONS

A specific inflammatory profile may be associated with developing higher antibodies in response to a third dose of SARS-CoV-2 vaccine in SOTRs.

Differential antibody production by symptomatology in SARS-CoV-2 convalescent individuals.. [PMID: 35169815 PMCID: PMC8845513 DOI: 10.1101/2022.02.09.22270718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The association between COVID-19 symptoms and antibody responses against SARS-CoV-2 is poorly characterized. We analyzed antibody levels in individuals with known SARS-CoV-2 infection to identify potential antibody-symptom associations. Convalescent plasma from 216 SARS-CoV-2 RNA+ individuals with symptomatology information were tested for the presence of IgG to the spike S1 subunit (Euroimmun ELISA), IgG to receptor binding domain (RBD, CoronaCHEK rapid test), and for IgG, IgA, and IgM to nucleocapsid (N, Bio-Rad ELISA). Logistic regression was used to estimate the odds of having a COVID-19 symptom from the antibody response, adjusting for sex and age. Cough strongly associated with antibodies against S1 (adjusted odds ratio [aOR]= 5.33; 95% CI from 1.51 to 18.86) and RBD (aOR=4.36; CI 1.49, 12.78). In contrast, sore throat significantly associated with the absence of antibodies to S1 and N (aOR=0.25; CI 0.08, 0.80 and aOR=0.31; 0.11, 0.91). Similarly, lack of symptoms associated with the absence of antibodies to N and RBD (aOR=0.16; CI 0.03, 0.97 and aOR=0.16; CI 0.03, 1.01). Cough appeared to be correlated with a seropositive result, suggesting that SARS-CoV-2 infected individuals exhibiting lower respiratory symptoms generate a robust antibody response. Conversely, those without symptoms or limited to a sore throat while infected with SARS-CoV-2 were likely to lack a detectable antibody response. These findings strongly support the notion that severity of infection correlates with robust antibody response.

Travel Surveillance and Genomics Uncover a Hidden Zika Outbreak during the Waning Epidemic

The Zika epidemic in the Americas has challenged surveillance and control. As the epidemic appears to be waning, it is unclear whether transmission is still ongoing, which is exacerbated by discrepancies in reporting. To uncover locations with lingering outbreaks, we investigated travel-associated Zika cases to identify transmission not captured by reporting. We uncovered an unreported outbreak in Cuba during 2017, a year after peak transmission in neighboring islands. By sequencing Zika virus, we show that the establishment of the virus was delayed by a year and that the ensuing outbreak was sparked by long-lived lineages of Zika virus from other Caribbean islands. Our data suggest that, although mosquito control in Cuba may initially have been effective at mitigating Zika virus transmission, such measures need to be maintained to be effective. Our study highlights how Zika virus may still be "silently" spreading and provides a framework for understanding outbreak dynamics. VIDEO ABSTRACT.

Safety and antitumor activity of the anti-PD-1 antibody pembrolizumab in patients with recurrent carcinoma of the anal canal

Background

Safety and efficacy of pembrolizumab, a humanized programmed death 1 monoclonal antibody, was assessed in KEYNOTE-028, a multicohort, phase Ib trial for patients with programmed death ligand 1 (PD-L1)-positive advanced solid tumors. We report results for the cohort of patients with advanced anal carcinoma.

Patients and methods

Patients with PD-L1-positive tumors (≥1%) received intravenous pembrolizumab 10 mg/kg once every 2 weeks for up to 2 years or until confirmed progression or unacceptable toxicity. Response was assessed every 8 weeks for the first 6 months and every 12 weeks thereafter per Response Evaluation Criteria In Solid Tumors, version 1.1. Primary endpoints were safety and overall response rate per investigator review. Secondary endpoints included progression-free survival, overall survival, and response duration. Data cutoff date was 1 July 2015.

Results

Of the 43 patients with advanced anal carcinoma evaluable for PD-L1 expression, 32 (74%) had PD-L1-positive tumors as assessed with the 22C3 prototype assay, of whom 25 were enrolled between April and September 2014. Sixteen patients (64%) experienced treatment-related adverse events; the most common ones were diarrhea and fatigue in four patients (16%) each and nausea in three patients (12%). There were no treatment-related deaths or discontinuations as of the data cutoff date. Among the 24 patients with squamous cell carcinoma histology, four had confirmed partial response, for an overall response rate of 17% [95% confidence interval (CI), 5%-37%) and 10 (42%) had confirmed stable disease, for a disease control rate of 58%. One additional patient with non-squamous histology had confirmed stable disease.

Conclusion

In this population of patients with PD-L1-positive advanced squamous cell anal carcinoma, pembrolizumab demonstrated a manageable safety profile and encouraging antitumor activity. These data support further study of pembrolizumab for this patient population.

ClinicalTrials.gov

NCT02054806.

Introducing dental hygienists in general practice to research - an in-practice evaluation programme in the United Kingdom

AIM

To introduce dental hygienists (DHs) in the UK to the principles of research through a practice-based product evaluation programme.

METHODS

The programme consisted of an initial training and orientation day with presentations on evidence-based practice, research methods and the structure of research papers. The programme and its aims were explained in detail, and participants were briefed on the methods to be used. Participants then recruited seven to ten patients from their practices (offices), carried out a baseline assessment of: plaque, gingival health, calculus and staining at anterior teeth, and gave the patients a questionnaire asking about their teeth and then provided a 3-month supply of a test toothpaste. About 10 weeks later, a follow-up assessment of the same variables was performed and the questionnaire was repeated. A second training day followed during which the DHs provided feedback of their experiences and received training in literature searching and critical appraisal of literature including interpretation of results.

RESULTS

Sixty-five DHs attended the first training day; 31 were able to recruit sufficient patients and attend the second training day. The DHs recruited 168 patients who received baseline and follow-up assessments. All the variables improved overall. Feedback from the DHs was very positive, and patients expressed delight with the care they had received.

CONCLUSIONS

Qualitative feedback for participating DHs suggests the programme met its aim and could be used in the future as a mechanism for helping DHs who want to increase their understanding of research methodology.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

Cefoperazone sodium impregnated polycaprolactone composite implant for osteomyelitis

The use of local antibiotics from a biodegradable implant for chronic osteomyelitis is an attractive alternative. The implant delivers high antibiotic concentration at tissue levels, obliterates dead space, aids bone repair and does not need to be removed. The purpose of this paper is to develop and evaluate a calcium sulphate and polycaprolactone based composite biodegradable implantable delivery system of cefoperazone sodium. Implants were prepared by modified fabrication technique to avoid solvent use. Interaction studies were carried out to check any incompatibility between ingredients. Prepared implants were evaluated for various in vitro parameters like dimensions, hardness, tensile strength, drug release profile and sterility. Morphological changes in pellet before and after drug release were evaluated by scanning electron microscopy. The pellet were also tested for microbiological efficacy and compared with plain drug solution in different concentrations. Developed pellets are regular in shape and size with good tensile strength. The release profile displayed drug levels above MIC continuously up to 2 months. Wide zone of inhibition by pellet against Staph. aureus as compared to drug solution proves its efficacy in treatment of osteomyelitis.

Paradoxical decrease in HDL-cholesterol and apolipoprotein A1 with simvastatin and atorvastatin in a patient with type 2 diabetes

Statins are agents widely used to lower LDL-cholesterol (LDL-C) in primary and secondary prevention of coronary heart disease. The five statins available in the UK (simvastatin, pravastatin, fluvastatin, atorvastatin and rosuvastatin) differ in many of their pharmacologic properties. In addition to lowering LDL-C, statins also increase HDL-cholesterol (HDL-C) moderately. There have been rare reports of significant HDL-C decreases in patients commenced on fibrates and when thiazolidinediones are added to fibrates. This is known as a 'paradoxical HDL-C decrease' as both groups of agents usually increase HDL-C. This phenomenon has never been clearly documented following statin therapy. We now describe a patient with type 2 diabetes who showed this paradoxical fall in HDL-C (baseline HDL-C: 1.8 mmol/L; on simvastatin 40 mg HDL-C 0.6 mmol/L; on atorvastatin 20 mg HDL-C 0.9 mmol/L) with a similar decrease in apolipoprotein A1. No similar decrease was observed with pravastatin and rosuvastatin therapy. This phenomenon appeared to be associated with statin treatment and not a statin/fibrate combination. Our patient clearly demonstrated a paradoxical HDL-C fall with simvastatin and atorvastatin, but not pravastatin or rosuvastatin. Simvastatin and atorvastatin share many pharmacokinetic properties such as lipophilicity while pravastatin and rosuvastatin are relatively hydrophilic and are not metabolized by cytochrome P450 3A4. However, these characteristics do not explain the dramatic reductions in HDL-C observed.

Applications of novel drug delivery system for herbal formulations

Over the past several years, great advances have been made on development of novel drug delivery systems (NDDS) for plant actives and extracts. The variety of novel herbal formulations like polymeric nanoparticles, nanocapsules, liposomes, phytosomes, nanoemulsions, microsphere, transferosomes, and ethosomes has been reported using bioactive and plant extracts. The novel formulations are reported to have remarkable advantages over conventional formulations of plant actives and extracts which include enhancement of solubility, bioavailability, protection from toxicity, enhancement of pharmacological activity, enhancement of stability, improved tissue macrophages distribution, sustained delivery, and protection from physical and chemical degradation. The present review highlights the current status of the development of novel herbal formulations and summarizes their method of preparation, type of active ingredients, size, entrapment efficiency, route of administration, biological activity and applications of novel formulations.

Phytoconstituents as photoprotective novel cosmetic formulations

Phytoconstituents are gaining popularity as ingredients in cosmetic formulations as they can protect the skin against exogenous and endogenous harmful agents and can help remedy many skin conditions. Exposure of skin to sunlight and other atmospheric conditions causes the production of reactive oxygen species, which can react with DNA, proteins, and fatty acids, causing oxidative damage and impairment of antioxidant system. Such injuries damage regulation pathways of skin and lead to photoaging and skin cancer development. The effects of aging include wrinkles, roughness, appearance of fine lines, lack of elasticity, and de- or hyperpigmentation marks. Herbal extracts act on these areas and produce healing, softening, rejuvenating, and sunscreen effects. We have selected a few photoprotective phytoconstituents, such as curcumin, resveratrol, tea polyphenols, silymarin, quercetin and ascorbic acid, and have discussed the considerations to be undertaken for the development of herbal cosmetic formulations that could reduce the occurrence of skin cancer and delay the process of photoaging. This article is aimed at providing specific and compiled knowledge for the successful preparation of photoprotective herbal cosmetic formulations.

Antiplatelet Resistance—Does it Exist and how to Measure it?

Aspirin and clopidogrel are the most commonly used antiplatelet agents in patients with coronary artery disease. The existence of resistance to these agents has been a controversial issue and new drugs are being developed to overcome this problem. Laboratory tests, which can identify resistance and correlate this with clinical outcome, are being studied in order to identify patients at risk of future thrombotic events. We discuss the evidence for the existence of antiplatelet resistance—both in the laboratory and in the clinical setting. So far, platelet aggregometry has been considered the gold standard test, but is very operator dependant, time consuming, and has shown little correlation with other available tests of antiplatelet resistance. We discuss the available tests of platelet function, their limitations, and evidence for their use. A simple, rapid, near-patient test, which is affordable and useful in the clinical (not just laboratory) setting, could allow risk stratification of patients and individualization of antiplatelet medication to improve outcome.

Antiplatelet Resistance-Does it Exist and How to Measure it?

Aspirin and clopidogrel are the most commonly used antiplatelet agents in patients with coronary artery disease. The existence of resistance to these agents has been a controversial issue and new drugs are being developed to overcome this problem. Laboratory tests, which can identify resistance and correlate this with clinical outcome, are being studied in order to identify patients at risk of future thrombotic events. We discuss the evidence for the existence of antiplatelet resistance-both in the laboratory and in the clinical setting. So far, platelet aggregometry has been considered the gold standard test, but is very operator dependant, time consuming, and has shown little correlation with other available tests of antiplatelet resistance. We discuss the available tests of platelet function, their limitations, and evidence for their use. A simple, rapid, near-patient test, which is affordable and useful in the clinical (not just laboratory) setting, could allow risk stratification of patients and individualization of antiplatelet medication to improve outcome.

Shear-induced global thrombosis test of native blood: pivotal role of ADP allows monitoring of P2Y12 antagonist therapy

BACKGROUND

It is claimed that in shear-induced platelet function tests, shear-stress is the sole agonist causing platelet activation and resultant thrombosis. However, the fact that red blood cells (RBC) are essential to achieve platelet aggregation in these tests supports recent evidence that ADP makes an important contribution to shear-induced platelet reaction.

AIM

To establish the role of ADP in shear-induced thrombosis, and investigate whether a shear-induced thrombosis test can assess ADP-receptor (P2Y12) antagonist medication.

METHODS

Blood from healthy volunteers was tested using the Global Thrombosis Test (GTT), before and after clopidogrel. To investigate the importance of contact of blood with plastic, the reactive part of the tube was primed with saline. We also investigated the effect of priming the tube with water, to cause localised haemolysis and ADP release.

RESULTS

Saline-priming prolonged occlusion times (OT) by 25% (p<0.01) confirming ADP release from platelets and RBC as a result of contact. Water-priming shortened OT, accelerating the thrombotic reaction (accelerated GTT; aGTT) (OT 379 vs. 177s, p<0.01). Clopidogrel increased OT (379 vs. 477s, p<0.01), preventing the shortening of aGTT-OT (177 vs. 362s, pre- and post-clopidogrel; p<0.01).

CONCLUSION

In addition to thrombin formation, ADP released from platelets and RBC in native blood subjected to high shear-stress makes an important contribution to the resultant thrombotic occlusion. The described aGTT sensitively detected the effect of clopidogrel and thus seems suitable for monitoring and individualizing ADP-receptor antagonist therapy. Parallel measurement of GTT and aGTT would allow assessment of both global thrombotic status and response to P2Y12 antagonist therapy.

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.