An increasing body of evidence supports the validity of self-sampling as an alternative to clinician collection for primary Human Papillomavirus (HPV) screening. Self-sampling effectively reaches ...underscreened women and can be a powerful strategy in low- and high-resource settings for all target ages. This work aims to summarize the current use of HPV self-sampling worldwide. It is part of a larger project that describes cervical cancer screening programmes and produces standardized coverage estimates worldwide. A systematic review of the literature and official documents supplemented with a formal World Health Organisation country consultation was conducted. Findings show that the global use of HPV self-sampling is still limited. Only 17 (12%) of countries with identified screening programs recommend its use, nine as the primary collection method, and eight to reach underscreened populations. We identified 10 pilots evaluating the switch to self-sampling in well-established screening programs. The global use of self-sampling is likely to increase in the coming years. COVID-19's pandemic has prompted efforts to accelerate HPV self-sampling introduction globally, and it is now considered a key element in scaling up screening coverage. The information generated by the early experiences can be beneficial for decision-making in both new and existing programs.
The knowledge that persistent human papillomavirus infection is the main cause of cervical cancer has resulted in the development of assays that detect nucleic acids of the virus and prophylactic ...vaccines. Up-to-date and reliable data are needed to assess impact of existing preventive measures and to define priorities for the future.
Best estimates on cervical cancer incidence and mortality are presented using recently compiled data from cancer and mortality registries for the year 2008.
There were an estimated 530 000 cases of cervical cancer and 275 000 deaths from the disease in 2008. It is the third most common female cancer ranking after breast (1.38 million cases) and colorectal cancer (0.57 million cases). The incidence of cervical cancer varies widely among countries with world age-standardised rates ranging from <1 to >50 per 100 000. Cervical cancer is the leading cause of cancer-related death among women in Eastern, Western and Middle Africa; Central America; South-Central Asia and Melanesia. The highest incidence rate is observed in Guinea, with ∼6.5% of women developing cervical cancer before the age of 75 years. India is the country with the highest disease frequency with 134 000 cases and 73 000 deaths. Cervical cancer, more than the other major cancers, affects women <45 years.
In spite of effective screening methods, cervical cancer continues to be a major public health problem. New methodologies of cervical cancer prevention should be made available and accessible for women of all countries through well-organised programmes.
Background:Penile carcinoma is an uncommon and potentially mutilating disease with a heterogeneous aetiology. Several risk factors have been established for its development. Human papillomavirus ...(HPV) infection seems to play an important role in the development of a subset of these carcinomas and its presence is thought to be related to the histological type. HPV prevalence in penile tumours is reported to be associated to a variety of morphological changes. Its determination will provide a better estimate for HPV related cancer burden and its preventable fraction.Methods:A systematic and comprehensive literature review of the major penile cancer studies published from 1986 until June 2008 evaluating the HPV prevalence among the different histological types was carried out.Results:31 studies including 1466 penile carcinomas were reviewed. Global HPV prevalence was 46.9%. Relative contribution was: HPV-16 (60.23%), HPV-18 (13.35%), HPV-6/11 (8.13%), HPV-31 (1.16%), HPV-45 (1.16%), HPV-33 (0.97%), HPV-52 (0.58%), other types (2.47%). Assessment of multiple infections contribution is limited due to study design. Basaloid and warty squamous cell carcinomas were the most frequent HPV-related histological types, but keratinising and non-keratinising subtypes also showed prevalence rates of around 50%.Conclusions:About half of the penile tumours were associated with HPV 16–18 with little presence of other genotypes. Research on the mechanisms behind penile carcinogenesis is warranted. Available HPV vaccines are likely to be effective in penile tumours.
A rapid multi-step procedure, potentially amenable to automation, was proposed for quantifying viable and active bacterial cells, estimating their biovolume using flow cytometry (FCM) and to ...calculate their biomass within the main stages of a wastewater treatment plant: raw wastewater, settled wastewater, activated sludge and effluent. Fluorescent staining of bacteria using SYBR-Green I + Propidium Iodide (to discriminate cell integrity or permeabilisation) and BCECF-AM (to identify enzymatic activity) was applied to count bacterial cells by FCM. A recently developed specific procedure was applied to convert Forward Angle Light Scatter measured by FCM into the corresponding bacterial biovolume. This conversion permits the calculation of the viable and active bacterial biomass in wastewater, activated sludge and effluent, expressed as Volatile Suspended Solids (VSS) or particulate Chemical Oxygen Demand (COD). Viable bacterial biomass represented only a small part of particulate COD in raw wastewater (4.8 ± 2.4%), settled wastewater (10.7 ± 3.1%), activated sludge (11.1 ± 2.1%) and effluent (3.2 ± 2.2%). Active bacterial biomass counted for a percentage of 30–47% of the viable bacterial biomass within the stages of the wastewater treatment plant.
Technologies proposed in the last decades for the reduction of the sludge production in wastewater treatment plants and based on the mechanism of cell lysis-cryptic growth (physical, mechanical, ...thermal, chemical, oxidative treatments) have been widely investigated at lab-, pilot- and, in some cases, at full-scale but the effects on cellular lysis have not always been demonstrated in depth. The research presented in this paper aims to investigate how these sludge reduction technologies affect the integrity and permeabilisation of bacterial cells in sludge using flow cytometry (FCM), which permits the rapid and statistically accurate quantification of intact, permeabilised or disrupted bacteria in the sludge using a double fluorescent DNA-staining instead of using conventional methods like plate counts and microscope.
Physical/mechanical treatments (ultrasonication and high pressure homogenisation) caused moderate effects on cell integrity and caused significant cell disruption only at high specific energy levels. Conversely, thermal treatment caused significant damage of bacterial membranes even at moderate temperatures (45–55 °C). Ozonation significantly affected cell integrity, even at low ozone dosages, below 10 mgO
3/gTSS, causing an increase of permeabilised and disrupted cells. At higher ozone dosages the compounds solubilised after cell lysis act as scavengers in the competition between soluble compounds and (particulate) bacterial cells. An original aspect of this paper, not yet reported in the literature, is the comparison of the effects of these sludge reduction technologies on bacterial cell integrity and permeabilisation by converting pressure, temperature and ozone dosage to an equivalent value of specific energy. Among these technologies, comparison of the applied specific energy demonstrates that achieving the complete disruption of bacterial cells is not always economically advantageous because excessive energy levels may be required.
Trophoblast research over the past decades has underlined the striking similarities between the proliferative, migratory and invasive properties of placental cells and those of cancer cells. This ...review recapitulates the numerous key molecules, proto-oncogenes, growth factors, receptors, enzymes, hormones, peptides and tumour-associated antigens (TAAs) expressed by both trophoblastic and cancer cells in an attempt to evaluate the genes and proteins forming molecular circuits and regulating the similar behaviours of these cells. Among the autocrine and paracrine loops that might be involved in the strong proliferative capacity of trophoblastic and cancer cells, epidermal growth factor (EGF)/EGF receptor (EGFR), hepatocyte growth factor (HGF)/HGF receptor (HGFR) (Met) and vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) loops may play a predominant role. Similar mechanisms of migration and invasion displayed by trophoblastic and malignant cells comprise alterations in the adhesion molecule phenotype, including the increased expression of α1β1 and αvβ3 integrin receptors, whereas another critical molecular event is the down-regulation of the cell adhesion molecule E-cadherin. Among proteases that may play an active role in the invasive capacities of these cells, accumulating evidence suggests that matrix metalloproteinase-9 (MMP-9) expression/activation is a prerequisite. Finally, an overview of molecular circuitries shared by trophoblast and cancer cells reveals that the activation of the phosphatidylinositol 3′-kinase (PI3K)/AKT axis has recently emerged as a central feature of signalling pathways used by these cells to achieve their proliferative, migratory and invasive processes.
In this work we calculate the static limit of the energy for a quark-antiquark pair from the Nambu-Goto action using a holographic approach with a deformed AdS space, with warp factor exp { ( κ z ) ...n / n } . From this energy we derive the Cornell potential for the quark-antiquark interaction. We also find a range of values for our parameters which fits exactly the Cornell potential parameters. In particular, setting the zero energy of the Cornell potential at 0.33 fermi, we find that κ = 0.56 GeV and n = 1.3 .
In the Anaerobic Side-Stream Reactor (ASSR), part of the return sludge undergoes alternating aerobic and anaerobic conditions with the aim of reducing sludge production. In this paper, viability, ...enzymatic activity, death and lysis of bacterial cells exposed to aerobic and anaerobic conditions for 16 d were investigated at single-cell level by flow cytometry, with the objective of contributing to the understanding of the mechanisms of sludge reduction in the ASSR systems.
Results indicated that total and viable bacteria did not decrease during the anaerobic phase, indicating that anaerobiosis at ambient temperature does not produce a significant cell lysis. Bacteria decay and lysis occurred principally under aerobic conditions. The aerobic decay rate of total bacteria (bTB) was considered as the rate of generation of lysed bacteria. Values of bTB of 0.07–0.11 d−1 were measured in anaerobic + aerobic sequence. The enzymatic activity was not particularly affected by the transition from anaerobiosis to aerobiosis. Large solubilisation of COD and NH4+ was observed only under anaerobic conditions, as a consequence of hydrolysis of organic matter, but not due to cell lysis.
The observations supported the proposal of two independent mechanisms contributing equally to sludge reduction: (1) under anaerobic conditions: sludge hydrolysis of non-bacterial material, (2) under aerobic conditions: bacterial cell lysis and oxidation of released biodegradable compounds.
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•Physiological cell status investigated in ASSR under aerobiosis/anaerobiosis.•Anaerobiosis at ambient temperature does not produce a significant cell lysis.•Passing from anaerobiosis to aerobiosis, cell lysis occurs under aerobiosis.•Anaerobiosis favours hydrolysis and solubilisation of non-bacterial material.•Mechanism of sludge reduction: anaerobic sludge hydrolysis + aerobic cell lysis.
In this study the functional status of bacterial biomass within a vertical subsurface flow (VSSF) constructed wetland was examined with the aim to understand the relationship between viable and dead ...bacteria in soil and influent/effluent wastewater and elucidate the large amount of dead cells in the soil which may affect the long-term behavior of the system. The quantification of viable and dead bacteria in influent and effluent wastewater and in the soil of a VSSF was performed at single-cell level by flow cytometry (FCM). An optimised pre-treatment was applied to soil samples using sodium pyrophosphate and ultrasonication at a specific energy of 80kJ/L. Viable and dead cells were detected on the basis of cellular membrane integrity coupling SYBR-Green I and Propidium Iodide. The bacteria profile in the VSSF soil depends on the depth and the material grain size. In the upper 0-10cm sand layer the number of total bacteria per gram of dry weight (DW) was higher (1.82109 cells/gDW) than in the deeper 40-50cm (4.8108 cells/gDW) probably due to the vertical feeding and a sieving effect of influent in the top layers. Bacterial biomass in the entire VSSF depth was 0.082mgVSS/gDW or 144gVSS/m3 (per cubic meter of VSSF bed). Size of viable bacteria in the VSSF was smaller (0.16 mu m3/cell) than typical size of activated sludge (0.23 mu m3/cell), due to lower nutrient conditions and a longer retention time of viable bacteria in the bed, estimated at around 130 days by mass balance. Dead bacteria were prevalent in the VSSF soil with a viable/dead bacteria ratio (V/D) of 0.52. The content of dead bacteria might be higher in the soil due to the presence of unsaturated zones not reached by fresh influent wastewater ("dead-zones"), where moisture and substrate are not so available and bacteria may die. Conversely, the higher V/D ratio (3.3) in the effluent reflects the enrichment of wastewater with viable bacteria during the passage through the VSSF bed and along preferential water flow, with higher water content and substrate availability, where the bacterial growth is favored.
•The physiological status of activated sludge treated with toxicants was evaluated.•Flow cytometry is suitable to investigate the response of bacteria to a toxicant.•3,5-Dichlorophenol has a strong ...effect on membrane integrity and cell disruption.•Real landfill leachate affects both bacteria integrity and enzymatic activity.•The FCM approach described in this paper may be extended to other bioprocesses.
In wastewater treatment plants the sensitivity of activated sludge to a toxicant depends on the toxicity test chosen, and thus the use of more than one test is suggested. The physiological status of bacteria in response to toxicants was analysed by flow cytometry to distinguish intact, permeabilised, active cells and cells disrupted. Results were compared with respirometry and bioluminescence bioassay (Vibrio fischeri).
3,5-Dichlorophenol (DCP) was used as reference xenobiotic. DCP has a strong effect on cellular integrity, causing an increase in permeabilised and disrupted cells. A reduction of 44–80% of intact cells with 6–30mgDCP/L for 5h was found. Inhibition of active cells was 25–49%, at 6–30mgDCP/L for 5h. The bioluminescence bioassay resulted oversensitive to DCP compared to tests based on activated sludge, while oxygen uptake rate was affected similarly to intact cells measured by flow cytometry.
Landfill leachate was tested: a detrimental impact on both cellular integrity and enzymatic activity was observed. Reduction of intact cells and active cells was by 32% and 61% respectively after addition of 50% (v/v) of leachate for 5h.
The flow cytometry analysis proposed here might be widely applicable in the monitoring of various toxicants and in other aquatic biosystems.
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