Signatures of the Optical Stark Effect on Entangled Photon Pairs from Resonantly Pumped Quantum Dots.

Two-photon resonant excitation of the biexciton-exciton cascade in a quantum dot generates highly polarization-entangled photon pairs in a near-deterministic way. However, the ultimate level of achievable entanglement is still debated. Here, we observe the impact of the laser-induced ac-Stark effect on the quantum dot emission spectra and on entanglement. For increasing pulse-duration-to-lifetime ratios and pump powers, decreasing values of concurrence are recorded. Nonetheless, additional contributions are still required to fully account for the observed below-unity concurrence.

Five-year risk of CIN3 after short-term HPV-DNA negativity in cytology-negative women: a population-based cohort study.

OBJECTIVE: To assess the 5-year risk of high-grade lesions in women with a transient high-risk HPV infection. DESIGN: Population-based cohort study. SETTING: HPV primary testing within population-based organised cervical cancer screening programmes. POPULATION: Italian women enrolled in seven pilot projects and attending the second round. METHODS: On the basis of the cytology triage performed on HPV-positive women, immediate colposcopy or HPV repeat at 12 months was recommended. Data were collected at the subsequent round 3-4 years after HPV infection clearance. MAIN OUTCOME MEASURES: Rates of HPV infection, CIN2+ and CIN3+ detection at subsequent round after HPV clearance, and relative risks (RR) in comparison with HPV-negative women (with 95% confidence interval). RESULTS: Data on 1230 women (1027 aged 25-64 years and 203 aged 35-64 years) have been analysed. Overall compliance with repeat HPV testing was 84%. In comparison with HPV-negative women, those with a transient HPV infection had higher proportions of HPV positivity (15% versus 3.7%) and of CIN2+ lesions (0.87% versus 0.23%) in round two; most of these (7/10) were CIN2; no cancers were detected, and CIN3 occurred in 3/1230 (0.24%). CONCLUSIONS: HPV-based protocols for cervical cancer screening allow long intervals for HPV-negative women; it is important to monitor the clinical outcome in the women with transient high-risk HPV infection. CIN3 detection is similar to that observed in routine European cytology-based screening programmes (CIN3+: 2.7‰); 5-year intervals may provide reasonable protection but longer intervals are not recommended. TWEETABLE ABSTRACT: A screening interval of 5 years (but no longer) appears safe in women with transient HPV detection.

A fall-off in cervical screening coverage of younger women in developed countries.

OBJECTIVES: To analyse cervical screening coverage data by age over time in a number of developed countries throughout the world, with specific emphasis on trends for younger women and on age differentials between younger and older women. METHODS: Routinely collected cervical screening statistics and survey data were collected on the proportion of women who have undergone cervical screening with cytology in seven countries in the period 1995 to 2005. RESULTS: Data for the 25-29 age group were examined. Coverage fell in most countries, in three by more than 5 percentage points. In two countries while overall coverage rose in the period, the rise was not as steep in the youngest group of women. Data for each available 5-year age group for the different countries shows a similar gradient in most, regardless of the absolute level of coverage. Although the trend is not uniform in every country, it appears that generally the gap between coverage of younger women and coverage of older women increased, sometimes dramatically, between the mid-1990s and the mid-2000s. CONCLUSIONS: There is a general trend in developed countries towards lower coverage in young women (25-29 years old). No common underlying cause has been clearly identified and there is a need for further studies to investigate the possible reasons for this phenomenon.

Age-specific patterns of unsatisfactory results for conventional Pap smears and liquid-based cytology: data from two randomised clinical trials.

OBJECTIVE: To investigate the rate of unsatisfactory cervical cell samples in liquid-based cytology (LBC) versus conventional cytology (CC) by age. DESIGN: Randomised clinical trials. SETTING: Population-based cervical cancer screening in the Netherlands and Italy. POPULATION: Asymptomatic women invited for screening enrolled in two randomised trials: Netherlands ThinPrep versus conventional cytology (NETHCON; 39 010 CC, 46 064 LBC) and New Technologies in Cervical Cancer Screening (NTCC; 22 771 CC, 22 403 LBC). METHODS: Comparison of categorical variables using Pearson's chi-square test, logistic regression and trend tests. MAIN OUTCOME MEASURES: Proportion of unsatisfactory samples, ratio of LBC versus CC, and variation by 5-year group. RESULTS: In NETHCON, a lower percentage of LBC samples were judged to be unsatisfactory compared with CC samples (0.33 versus 1.11%). There was no significant trend in unsatisfactory results by age group for conventional cytology (P(trend) = 0.54), but there was a trend towards an increasing percentage of unsatisfactory results with increasing age for LBC (P(trend) < 0.001). In NTCC, a lower percentage of LBC samples were judged to be unsatisfactory compared with conventional cytology (2.59 versus 4.10%). There was a decrease in the unsatisfactory results by age group with conventional cytology (P(trend) < 0.001) and with LBC (P(trend) = 0.01), although the latter trend arose from the 55-60-years age group (P(trend) = 0.62 when excluding this group). CONCLUSIONS: The clinical trial in which the results were collected and the cytologic method used were the most important determinants of unsatisfactory cytology. In all situations, the proportion of unsatisfactory samples was lower in LBC compared with CC. The effects of age depended on the criteria used to define unsatisfactory results.

European Guidelines for Quality Assurance in Cervical Cancer Screening. Second edition--summary document.

European Guidelines for Quality Assurance in Cervical Cancer Screening have been initiated in the Europe Against Cancer Programme. The first edition established the principles of organised population-based screening and stimulated numerous pilot projects. The second multidisciplinary edition was published in 2008 and comprises approximately 250 pages divided into seven chapters prepared by 48 authors and contributors. Considerable attention has been devoted to organised, population-based programme policies which minimise adverse effects and maximise benefits of screening. It is hoped that this expanded guidelines edition will have a greater impact on countries in which screening programmes are still lacking and in which opportunistic screening has been preferred in the past. Other methodological aspects such as future prospects of human papillomavirus testing and vaccination in cervical cancer control have also been examined in the second edition; recommendations for integration of the latter technologies into European guidelines are currently under development in a related project supported by the European Union Health Programme. An overview of the fundamental points and principles that should support any quality-assured screening programme and key performance indicators are presented here in a summary document of the second guidelines edition in order to make these principles and standards known to a wider scientific community.

Do women >or=50 years of age need as much screening as women <50 years after they have had negative screening results?

To assess the adequacy of a routine screening to identify cervical intraepithelial neoplasia 2 or worse (CIN2+) in women over 50 years of age, a retrospective cohort was set in six Italian organised population-based screening programmes. In all, 287 330 women (1 714 550 person-years of observation, 1110 cases) screened at age 25-64, with at least two cytological screening tests, the first negative, were followed from their first negative smear until a biopsy proven CIN2+ lesion or their last negative smear. For women aged 25-49 and 50-64 years, crude and age-standardised detection rate (DR), cumulative risk (CR), adjusted hazard risk for number of previous negative screens, probability of false-positive CIN2+ after two or more smear tests were calculated. Detection rate is significantly lower over 50 years of age. Multivariable analysis shows a significant protective effect from four screening episodes (DR=0.70, 95% CI: 0.51-0.97); the effect of age >or=50 is 0.29 (95% CI: 0.24-0.35). The CR of CIN2+ is at least eightfold higher in women <50 (CR=2.06, 95% CI: 1.88-2.23) after one previous negative test than in women >or=50 years with four screens (CR=0.23, 95% CI: 0.00-0.46). Over 50 years of age, after four tests at least three false-positive cases are diagnosed for every true positive. Benefits arising from cytological screening is uncertain in well-screened older women.

Interlaboratory reproducibility of liquid-based equivocal cervical cytology within a randomized controlled trial framework.

Within a multicentre controlled trial framework, an external quality control (EQC) was scheduled to evaluate the interlaboratory reproducibility of liquid-based cytology. In particular, this EQC intended to evaluate the reproducibility of the ASCUS diagnosis.A selected set of 30 slides (4 within normal limit cases, 16 atypical squamous cells of undetermined significance; 4 low-grade squamous intraepithelial lesions and 6 high-grade squamous intraepithelial lesions) circulated among the 13 laboratories involved in the trial.Kappa values were obtained from the comparison between individual laboratory diagnoses and majority diagnoses with target diagnoses. Specific kappa values resulted moderate to high for HSIL and low to moderate for LSIL and WNL. Meanwhile, the specific kappa for ASCUS was below 0.4 in 12 of 13 participating laboratories. The lack of reproducibility for ASCUS was not a result of the introduction of this new technology but rather to the low reproducibility of the ASCUS category itself stemming from intrinsic uncertainties in the reporting criteria.

Worldwide distribution of human papillomavirus types in cytologically normal women in the International Agency for Research on Cancer HPV prevalence surveys: a pooled analysis.

BACKGROUND: The proportion of women infected with human papillomavirus (HPV) varies greatly across populations, as might the distribution of HPV types. We aimed to compare HPV-type distribution in representative samples of women from different world regions. METHODS: Women were randomly selected from the general population of 13 areas from 11 countries (Nigeria, India, Vietnam, Thailand, Korea, Colombia, Argentina, Chile, the Netherlands, Italy, and Spain). A standardised protocol was used for cervical specimen collection. All HPV testing was by GP5+/6+ PCR-based EIA. The proportion of HPV-positive women infected with different HPV types was compared by study area and between pooled regions with age-adjusted odds ratios (ORs) with corresponding 95% floating CIs. FINDINGS: 15 613 women aged 15-74 years without cytological abnormalities were included in a pooled analysis. Age-standardised HPV prevalence varied nearly 20 times between populations, from 1.4% (95% CI 0.5-2.2) in Spain to 25.6% (22.4-28.8) in Nigeria. Although both overall HPV prevalence and HPV16 prevalence were highest in sub-Saharan Africa, HPV-positive women in Europe were significantly more likely to be infected with HPV16 than were those in sub-Saharan Africa (OR 2.64, p=0.0002), and were significantly less likely to be infected with high-risk HPV types other than HPV16 (OR 0.57, p=0.004) and/or low-risk HPV types (OR 0.44. p=0.0002). Women from South America had HPV-type distribution in between those from sub-Saharan Africa and Europe. Heterogeneity between areas of Asia was significant. INTERPRETATION: Heterogeneity in HPV type distribution among women from different populations should be taken into account when developing screening tests for the virus and predicting the effect of vaccines on the incidence of infection.

Impact of the introduction of organised screening for cervical cancer in Turin, Italy: cancer incidence by screening history 1992-98.

After an organised cervical screening programme was introduced in Turin in 1992, the age-adjusted cervical cancer incidence ratio in 1992-98 was 0.81 (95% confidence interval (CI) 0.59-1.09) for invited vs not invited women and 0.25 (95% CI 0.13-0.50) for attenders vs non attenders. An organised screening programme can further reduce cervical cancer incidence in an area where substantial spontaneous activity was previously present.

Cervical cancer screening programmes and policies in 18 European countries.

A questionnaire survey was conducted by the Epidemiology Working Group of the European Cervical Cancer Screening Network, and the International Agency for Research on Cancer, IARC, between August and December 2003 in 35 centres in 20 European countries with reliable cervical cancer incidence and/or mortality data in databanks held at IARC and WHO. The questionnaire was completed by 28 centres from 20 countries. The final tables included information on 25 centres from 18 countries. Six countries had started screening in the 1960s, whereas 10 countries or regions had started at least a pilot programme by 2003. There were six invitational and nine partially invitational programmes, the rest employing opportunistic screening only. Recommended lifetime number of smears varied from seven to more than 50. Coverage of smear test within the recommended screening interval (usually 3 or 5 years) was above 80% in three countries. Screening registration took place in 13 programmes. Eight programmes reported the rates of screen-detected cervical cancers and precursor lesions. There was wide variation in the CIN3 detection rates. International guidelines and quality assurance protocols are useful for monitoring and evaluating screening programmes systematically. Our survey indicated that the recommendations as currently given are met in only few European countries. Health authorities need to consider stronger measures and incentives than those laid out in the current set of recommendations.

Interlaboratory reproducibility of atypical squamous cells of undetermined significance report: a national survey.

The study was aimed at assessing interlaboratory reproducibility in the reporting of cervical smears in the atypical squamous cells of undetermined significance (ASCUS) category. A set of 50 selected slides circulated among 89 laboratories, currently involved in population-based screening programmes for cervical cancer, which provided a diagnostic report according to four main reporting categories based on the 1991 Bethesda system. Interlaboratory agreement was determined according to kappa (K) statistics: overall and weighted K values were determined for each laboratory and for single reporting categories. The results showed a very low reproducibility for the ASCUS category. This finding supports the Bethesda system 1991 recommendation to limit the use of this reporting category and suggests that the clinical response to ASCUS reports should be decided locally, based on the observed positive predictive value for cervical intraepithelial neoplasia 2 or more severe lesions.

Effect of circulation and discussion of cervical smears on agreement between laboratories.

The study objective was assessing whether circulation of smears and discussion of those with differing interpretation can increase reproducibility between laboratories. The study included: the blind interpretation of a first set of 194 smears among seven laboratories, the discussion of smears with discrepant diagnoses during the previous phase and the blind interpretation of a second set of smears of same size and characteristics. After discussions, the overall weighted kappa increased in five laboratories (substantially in three : +50%, +27% and +20%). However, no change was observed in one laboratory and a slight decrease (-4%) in another. The latter interpreted the second set of smears at a longer time interval from discussions. Agreement improved for all diagnostic classes except low grade intraepithelial neoplasia (LSIL). Overall, the intervention increased diagnostic agreement, but its effect varied with laboratory and by diagnostic class and could be transient. Continued programmes of smear exchange and discussion appear to be advisable.

Spirohydantoins from D-ribose as new potent enzymatic inhibitors.

Anomeric spirohydantoin derivatives from monosaccharides are known for various biological properties. We describe herein the synthesis of the 3-spirohydantoin derivatives of D-allose and D-ribose. The key step is the stereoselective glyco-alpha-aminonitrile formation from ulose derivatives of D-glucose and D-xylose using titanium tetra-isopropoxide as a mild and efficient catalyst. Target compounds were synthesized from these intermediates. The glucidic moiety was partially or totally deprotected under acidic conditions. These new heterocyclic monosaccharidic derivatives are potent glycogen phosphorylase inhibitors.

Asymmetric synthesis of novel isoindolines: azasaccharide mimics as potential enzyme inhibitors.

2',3'-Dideoxy-2',3'-didehydronucleosides and azasaccharides are known to possess antiviral activity. The synthesized 1-methoxyisoindoline system (10), which is related to the above nucleosides, is potentially stable in-vivo. The 1-methoxyisoindoline was synthesized from the achiral phthalaldehyde in 10 steps via an enantiomerically pure diol obtained by Sharpless asymmetric dihydroxylation. The new heterocyclic compound is an azosaccharide mimic which provides an access to a new series of nucleoside analogues with potential as antiretroviral agents (anti-HIV) and as glycosidase inhibitors.

Synergistic efficacy of 3n-butyrate and 5-fluorouracil in human colorectal cancer xenografts via modulation of DNA synthesis.

BACKGROUND & AIMS: Butyrate, produced in the colon lumen, maintains mucosal cell homeostasis. Poorly diffusible, its access is compromised in growing colon cancers and absent in distant metastases. Butyrate regulates DNA synthesis. We postulated that systemic administration of butyrate should reduce colon cancer growth and enhance 5-fluorouracil (5-FU) efficacy. METHODS: A stable derivative of butyrate (3n-But) was used. The antitumoral efficacy of 5-FU and 3n-But, alone or combined, was evaluated in human colorectal cancers (hCRCs) subcutaneously, orthotopically, or intrasplenically grafted into nude mice. Thymidylate synthase (TS) and thymidine kinase (TK) mRNA expression, proliferation, apoptosis, and cell cycle alterations were studied. RESULTS: In vivo, 5-FU alone inhibited growth of only 3 of the 12 hCRCs tested and 3n-But alone had no effect; the 5-FU/3n-But combination inhibited growth of all 16 hCRCs tested. The hCRCs differed in their p53 and microsatellite instability status. 5-FU/3n-But decreased TK and TS mRNA expression by 20- and 40-fold, respectively, and TS activity by 75%, stopped cell proliferation without affecting cell differentiation, and significantly enhanced apoptosis. 3n-But potentiated the efficacy of Tomudex and methotrexate, 2 TS inhibitors, but not that of oxaliplatin. In vitro, 5-FU/3n-But inhibited [3H]thymidine but not bromodeoxyuridine incorporation and induced apoptosis in hCRC cell lines. Cells treated with 5-FU/3n-But did not accumulate in G1 nor in S phase of the cell cycle, while 5-FU and 3n-But arrested the cycle in S and in G1 phase, respectively. 3n-But prevented the cell rescue from 5-FU-induced cytotoxicity by uridine or thymidine. CONCLUSIONS: 3n-But and TS inhibitors acted synergistically against colorectal cancers, independently of the genetic alterations of the hCRCs. The mechanism of action of 5-FU/3n-But could be enhanced reduction of TS and prevention of thymidine salvage in DNA synthesis.

Overview of important cervical cancer screening process values in European Union (EU) countries, and tentative predictions of the corresponding effectiveness and cost-effectiveness.

The objective was the evaluation of the (cost-)effectiveness of cervical cancer screening in the European Union (EU) countries. Data were collected on recommended screening age ranges and intervals, coverage, proportion of non-negative smears and smear use. Estimates reported by representatives of each participating Member State were compared, and used as input for model based on (using the MISCAN simulation model for cancer screening) effectiveness and cost-effectiveness calculations. Differences in coverage from below 50 to 82% resulted in more or less proportional differences in expected percentage life-years lost reduction, almost regardless of differences in 7-50+ smears recommended in a lifetime. Differences in screening intensity (resulting from the recommended number of smears per lifetime and the number of excess smears on top of these recommendations) resulted in more than 2-fold difference in the expected number of smears per percentage life-years lost reduction. (Cost-)effectiveness predictions would have greatly improved if estimates of long-term coverage had also been available. To conclude, estimates for a restricted set of well defined parameters - a few for short and long-term coverage and one for the total number of smears - are quite useful for country-specific (cost-)effectiveness evaluations. The main, and to some extent, unsolvable problem for further improvement of the analysis is the lack of reliable country-specific estimates for the background risk of cervical cancer in women eligible for screening in the near future.

Cervical cancer screening in Italy.

Until recently cervical cancer screening in Italy has been mainly spontaneous, with only a few organised programmes. This resulted in low coverage and high frequency of tests in screened women (mostly every year). The situation is, however, rapidly changing. In 1996 nationwide organised programmes, on a regional basis, were recommended. National guidelines recommend personal invitation of women aged 25-64 years for a Pap-test every third year. At the end of 1999 34% of the Italian population 25-64 years old was included in organised programmes. Most organised programmes have fail-safe systems for women referred for colposcopy, protocols for diagnostic work-up and treatment and reference centres for such phases, according to the recommendations of national and European guidelines. However the size of laboratories is frequently smaller than recommended. Most organised programmes implement quality assurance processes for cytology interpretation, that have been intensive in some centre, but there is no nationwide standardisation. In recent years data for monitoring screening activity have been collected in a standardised way by most organised programmes, in the framework of GISCi (Italian Group for Cervical Cancer Screening) allowing internal and external comparisons. In some cases strong improvements of coverage after the introduction of an organised activity have been documented. Data, however, suggest a relevant heterogeneity of criteria for cytology interpretation, requiring actions to increase consistency. The impact of these transformations on incidence of cervical cancer will be observed in the future: preliminary results suggest a reduction in older programmes.

Prediction of high-grade cervical intraepithelial neoplasia in cytologically normal women by human papillomavirus testing.

Human papillomavirus (HPV) testing has been suggested for primary screening of cervical cancer. Prediction of future high-grade cervical lesions is crucial for effectiveness and cost. We performed a case control study in a retrospective cohort of women with at least two cervical smears, all but the last one being negative, from the organized cervical screening programme in Florence, Italy. We searched for high-risk HPV in all previous, archival, smears from cases (new histologically confirmed cervical intraepithelial neoplasia (CIN) grade II or worse) and in one previous smear from each control (last smear cytologically normal, matched by age and interval (latency) from last smear). We applied polymerase chain reaction (PCR), and the b-globin gene was used as a DNA preservation marker. High-risk HPV was identified in 71/92 (77.17%) previous smears from 79 cases and 17/332 controls (5.12%). The odds ratio (OR) was 63.76 (95% CI 30.57-132.96). Among cases the proportion of HPV-positive smears declined slightly with increasing latency. Among cases, HPV was found in 81.24% (95% CI 69.93-88.96%) of smears with latency < 4 years and in 67.80% (95% CI 47.72-82.93%) of those taken at longer intervals, up to 6 years. These findings suggest that testing for high-risk HPV allows predicting 80% of CINII/III 3 years before the cytological diagnosis and two thirds 6 years before. They also suggest that testing women negative for high-risk HPV at longer interval and strictly following-up women who are HPV positive could be an effective strategy for cervical cancer screening.