Investigating the particle to fibre transition threshold during electrohydrodynamic atomization of a polymer solution.

Electrohydrodynamic atomization (EHDA) is a key research area for producing micro and nano-sized structures. This process can be categorized into two main operating regimes: electrospraying for particle generation and electrospinning for fibre production. Producing particles/fibres of the desired size or morphology depends on two main factors; properties of the polymeric solution used and the processing conditions including flow rate, applied voltage and collection distance. In this work the particle-fibre transition region was analyzed by changing the polymer concentration of PLGA poly (lactic-co-glycolic acid) in acetone between 2 and 25wt%. Subsequently the processing conditions were adjusted to study the optimum transition parameters. Additionally the EHDA configuration was also modified by adding a metallic plate to observe the deposition area. The diameter and the distance of the plate from the capillary tip were adjusted to investigate variations in particle and fibre morphologies as well. It was found that complete transition from particles to fibres occurs at 20wt% indicating concentration to be the dominant criterion. Low flow rates yielded fibres without beads. However the applied voltage and distance between the tip of the nozzle jetting the polymer solution and collector (working distance) did not yield definitive results. Reducing the collector distance and increasing applied voltages produces smooth as well as beaded fibres. Addition of a metal plate reduces particle size by ~1µm; the fibre size increases especially with increasing plate diameter while bead density and size reduces when the disc is fixed closer to the capillary tip. Additionally, the deposition area is reduced by 70% and 57% with the addition of metal plates of 30mm and 60mm, respectively. The results indicate that a metal plate can be utilized further to tune the particle/fibre size and morphology and this also significantly increases the yield of EHDA process which is currently a limitation in adopting it as a mass production technique.

Unplanned alcohol withdrawal: a survey of consecutive admissions to an acute medical unit in 2010 and 2011.

BACKGROUND: Alcohol-related presentations to hospital have been increasing in the UK in recent years, including the occurrence of acute withdrawal. This study sought to better characterize the clinical features, patterns of treatment and outcomes in this patient group. METHODS: Patients admitted to the Acute Medical Unit of York Hospital due to acute alcohol withdrawal are normally treated according to a protocol that involves both fixed-dose and symptom-triggered drug administration. Admissions between 2010 and 2011 inclusive were studied. RESULTS: There were 211 admission episodes solely due to acute alcohol withdrawal, involving 127 patients (97 men, 76.4%) with median age of 45 years (interquartile range: 39-52 years). There was a high prevalence of depression (34%), alcoholic liver disease (22%) and drug misuse (12%). Total dose of chlordiazepoxide varied between 0 and 610 mg and tapered rapidly after the first day of admission. Vitamin supplements were administered to >90% of patients, including parenteral and oral in 74%, parenteral alone in 9% and oral alone in 9%. A specialist alcohol nurse reviewed patients while in hospital in 40% of cases. Approximately one-third of patients had multiple admissions for alcohol withdrawal during the study period. CONCLUSION: A high prevalence of physical and mental health disorders was observed. The local policy permitted high initial chlordiazepoxide doses and prompt downward titration, with a broad range of doses between individuals. Approximately 10% required no specific therapy, and there may be opportunities for developing alternative pathways for delivery of care in an ambulatory setting for these patients.

Cytopathology in the United Kingdom: 1854 to the present.

The paper traces the history of cytopathology in the U.K. from the time of the pioneers in the last century to the 1930s and continues with the development of cervical and breast screening, with reference to training and quality control, to the present time. Diagn. Cytopathol. 2000;22:203-206.

Cell preparation methods and criteria for sample adequacy. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: Cell Preparation Methods Standardized fixation and optimal staining Sampling of cervix, sampling error, homogenization of sample, subsampling Assessment of liquid-based preparations: efficacy and economic impact Training and transitional procedures before full implementation of new technologies Criteria for Sample Adequacy Clinician responsibility for collecting and providing representative sample to laboratory Collection instruments, number of slides Cellular content of samples: evidence of transformation zone (TZ) sampling, number of squamous cells present, obscuring factors Screening issues CONSENSUS POSITION The conventional cervical smear remains the standard method of cervical cancer screening but has limitations in individual test sensitivity and specificity. Sample takers should: (1) receive appropriate training in sample collection, (2) be held responsible for providing the laboratory with appropriate samples, and (3) have their performance monitored. The instruments used for sampling should collect cells from both the ectocervix and endocervix; optimally, TZ sampling, represented by the presence of endocervical or squamous metaplastic cells, should be identifiable in samples other than atrophic specimens. The adequacy of a specimen (as judged microscopically) does not guarantee that it is representative of the cervix. Each cytology report should include a comment on cellular content/adequacy of the specimen. Liquid-based preparations may overcome many of the inherent problems with the conventional cervical smear. ONGOING ISSUES: We need further data on the cost-effectiveness of making two slides from cervical specimens and/or using two samplers rather than a single one. Do we have enough information to make recommendations as to the appropriate type of sampler to be used in particular situations, such as routine screening? What is the best method of screening for/detecting endocervical glandular neoplasia? How are such terms as unsatisfactory and inadequate defined in cervical cytology classifications other than the Bethesda System? What number and types of epithelial cells should be present (visualized) in a cervical smear or liquid-based preparation for it to be considered adequate? Do we need to have evidence of TZ sampling in specimens taken during the follow-up period after treatment of squamous intraepithelial lesion or after detection of endocervical glandular neoplasia? What criteria for obscuring factors, such as blood and inflammation, should be used in assessing adequacy? Cost-benefit analyses of utilizing liquid-based preparations are needed. Should we inform women about the technical details of the test methods available or chosen by the laboratory? Are women in a position to decide which method is the most appropriate to assess their cervical scrape sample? We need to obtain more information about the properties of proprietary liquid fixative/transport media with respect to inactivation of viral pathogens, tuberculosis and other bacterial pathogens and suitability for immunobiologic and molecular tests, etc. We need to obtain more information on the use of stoichiometric stains and the limitations of Papanicolaou stain for image analysis systems. The use of liquid-based preparations for nongynecologic cytopathology and ancillary tests must be considered, including criteria for adequacy. We need to obtain more information on the time required for and best methods of training experienced cytotechnologists to become competent at assessing liquid-based cervical preparations.

PAPNET. The human and other dimensions.

OBJECTIVE: To study the effect of specimen preparation and observer variation on the accuracy of interpretation of PAPNET images. STUDY DESIGN: The PAPNET scanner makes use of conventional Papanicolaou-stained smears and presents the cytologist with pictures of selected "abnormal" cells. This minitrial was designed to investigate the human variability in different grades of personnel and to consider any problems caused by the use of conventional smears. RESULTS: The personnel involved consisted of a consultant cytopathologist, a senior chief medical laboratory scientific officer and two senior cytotechnologists, one from another laboratory. Experience with the system ranged from six months to a few years. The best interobserver agreement was found between the senior chief and the senior technologist, who worked in the same laboratory. Majority agreement with the "gold standard" (at least three out of four) was highest for the extremes of "negative" and "high grade" smears. Three high grade smears were "missed" due to the quality of the smears and scantiness of "abnormal" cells. CONCLUSION: Although fatigue in screening is reduced by the interactive mode, it does not overcome the subjectivity of human examination both in review of the dat tape and in microscopic examination of selected cells on the slides. Experience with the method is important, and different background experiences will have an effect. The technical quality of the smear is important since the automated scanner cannot be expected to select abnormal cells if they are absent or obscured for any reason. A monolayer may be the solution, although at greater cost.

Consistency of a double PAPNET scan of cervical smears.

OBJECTIVE: To determine the reproducibility and accuracy of the PAPNET system in finding and presenting abnormal and atypical cells. STUDY DESIGN: To assess the potential variation of a double PAPNET scan on the same cervical smear, 516 cervical smears from women with abnormal histologic diagnoses were scanned twice via PAPNET and reviewed by two independent examiners in a double-blind trial. RESULTS: The false negative rate of 5.7% in conventional screening was reduced to 0.4% and 0.8%, respectively, by PAPNET testing. The resulting concurrence of the first and the second PAPNET reviews was 99.2%, indicating the accuracy, sensitivity and consistency of this supplemental test. CONCLUSION: The results obtained demonstrate the reproducibility and accuracy of the system in finding and presenting abnormal and atypical cells.

Inter- and intra-observer variation in the reporting of cervical smears: specialist cytopathologists versus histopathologists.

One hundred and ten cervical smears were circulated to five specialist consultant cytopathologists and five consultant histopathologists. Of these smears, 100 were randomized and re-circulated. The cytopathologists reported endocervical cells and wart virus infection more frequently than the histopathologists, although neither group showed good inter-observer agreement for either assessment. Apart from smear adequacy and the presence of endocervical cells, both groups showed good intra-observer agreement in all the parameters measured. This suggests that overall individuals were applying their own personal criteria with consistency over time, although a previous study had shown considerable lack of inter-observer agreement among the histopathologists on the grade of dyskaryosis and the management recommendation. The results indicate that specialist cytopathologists bring a different viewpoint to the reporting of cervical smears than histopathologists. They also show a lack of standardization in the reporting of smears despite the guidelines issued by the British Society for Clinical Cytology.

Health and cancer prevention: knowledge and beliefs of children and young people.

OBJECTIVE: To collect information from children and young people about their knowledge of and attitudes towards cancer and their understanding of health and health related behaviours to inform future health promotion work. DESIGN: Questionnaire survey of 15-16 year olds, and interviews with play materials with 9-10 year old children. SETTING: Six inner city, suburban, and rural schools. SUBJECTS: 226 children aged 15-16 years and 100 aged 9-10 years. MAIN OUTCOME MEASURES: Knowledge about different types of cancer; beliefs about health; sources of information; quality of research data obtainable from young children about cancer and health. RESULTS: Both samples knew most about lung cancer, but there was also some knowledge of breast and skin cancer and leukaemia. Smoking, together with pollution and other environmental factors, were seen as the dominant causes of cancer. Environmental factors were mentioned more often by the inner city samples. Television and the media were the most important sources of information. Young people were more worried about unemployment than about ill health. More than half the young people did not describe their health as good, and most said they did not have a healthy lifestyle. Children were able to provide detailed information about their knowledge and understanding by using drawings as well as interviews. CONCLUSIONS: Children and young people possess considerable knowledge about cancer, especially about lung cancer and smoking, and show considerable awareness of predominant health education messages. Despite this knowledge, many lead less than healthy lifestyles. Health is not seen as the most important goal in life by many young people; the circumstances in which many children and young people live are not experienced as health promoting.

Interobserver variation in the diagnosis and grading of dyskaryosis in cervical smears: specialist cytopathologists compared with non-specialists.

AIMS: To compare the assessment of dyskaryosis in cervical smears made by specialist consultant cytopathologists and consultant general histopathologists. METHODS: One hundred and ten cervical smears were circulated to 10 observers from five district general hospital histopathology departments and five major departments of cytopathology. Their responses were analysed by five consultant general histopathologists and five consultant specialist cytopathologists. In 54 of the 110 cases, the histology of a corresponding cervical biopsy specimen was compared with the smear assessments. RESULTS: Specialist cytopathologists were more consistent than non-specialists when diagnosing and grading dyskaryosis. They chose the higher grades of dyskaryosis more frequently than the non-specialists. The cytopathologists recommended referral for colposcopy more frequently, but if they asked for a repeat smear, they wanted it done within three months more frequently than the histopathologists. The specialists were more frequently in agreement with the biopsy grade of intra-epithelial neoplasia than the non-specialists, whose smear diagnoses tended to underestimate the severity of the histopathological abnormality. CONCLUSIONS: This study has shown major differences between specialist and non-specialist cytopathologists in the diagnosis and grading of cervical smears and in the recommended management of patients with abnormal smears. These differences may result in uneven clinical management of women with smear abnormalities. It is therefore important to explore possible strategies for standardising the reporting of cervical smears, such as centralisation of screening services, accreditation in cytopathology for non-specialist consultants, and the value of participation in external quality assessment schemes.

An analysis of the variation of human interpretation: Papnet a mini-challenge.

The Papnet was given a mini-challenge of 200 cervical smears loaded to 50% with varying degrees of abnormality as interpreted by the originating laboratory. The range of abnormality extended from 'atypia' to invasive cancer and a few 'glandular' lesions were included as were a few smears which had been reported as 'inadequate'. Three cytologists (two cytopathologists and one cytotechnologist) read and analysed the 128 monitor pictures per slide, selected by the Scanning Algorithm and Neural Network systems. These results were compared with a 'gold standard' report on the glass slide produced by two cytopathologists. The analysis was done for each individual cytologist, for cases in which all three agreed, for a consensus between two of the three and for the 'best of three'. The latter gave an error rate of 4% false negative (Papnet scan negative) and 10% 'false positive' (referred for glass slide examination). Individual cytologists had higher error rates demonstrating that errors could be due to human interaction and not necessarily to the Scanner. This also indicated that wide experience in interpretation of monitor images is needed to achieve high quality results.

Semi-automated cervical smear pre-screening systems: an evaluation of the Cytoscan-110.

This paper reports a test of a system for provision of machine assistance in cervical cytology screening. The hypothesis tested was that if the results of examination by a screener of a small number of high-ploidy cells on specially prepared monolayers, automatically selected and presented by the system, were combined with machine measurement of cell and cell population characteristics, it would be possible to distinguish conditions requiring further action on the part of a cytology service from those in which the patient could safely be signed out. The system appeared broadly capable of this discrimination, with a false-negative error not significantly different (for the numbers tested) on CIN1 and more severe cases to that obtaining for routine screening of the parallel PAP smears, and also to results obtained by a panel of three observers. The machine system appeared to do better than other systems in selecting borderline cases for review, but this may have been an artefact of the method of evaluation used: all results were compared with a 'reference diagnosis', which was computed using statistical techniques to integrate diagnostic information from all available sources. The false-negative error-rate of the system amounted to 5% of high-grade cases, 17% of CIN1's and 29% of borderlines, but were not substantially different from the FN rates for other reporting systems on the same material. The proportion of negative cases referred back for full cytological diagnosis was 34%. Despite this high false-positive rate, the system is potentially cost-effective in use.

Monoclonal immunofluorescence compared with silver stain for investigating Pneumocystis carinii pneumonia.

Two hundred and eighty two specimens from 220 patients positive for HIV with respiratory tract symptoms, or febrile illness, or both, were examined for the presence of Pneumocystis carinii. Specimens were either induced sputum samples or bronchoalveolar lavage fluids. To establish the optimal method for laboratory diagnosis a comparison was made of detection of the organism by use of monoclonal antibody and immunofluorescence with conventional silver staining methods. Three commercially available reagents for immunofluorescence were also compared. Immunofluorescence was significantly more sensitive than the silver stain and the best results for immunofluorescence were obtained using. Northumbria Biologicals Ltd reagents.