Raman Spectral Signatures of Cervical Exfoliated Cells from Liquid-Based Cytology Samples

It is widely accepted that cervical screening has significantly reduced the incidence of cervical cancer worldwide. The primary screening test for cervical cancer is the Papanicolaou (Pap) test, which has extremely variable specificity and sensitivity. There is an unmet clinical need for methods to aid clinicians in the early detection of cervical precancer. Raman spectroscopy is a label-free objective method that can provide a biochemical fingerprint of a given sample. Compared with studies on infrared spectroscopy, relatively few Raman spectroscopy studies have been carried out to date on cervical cytology. The aim of this study was to define the Raman spectral signatures of cervical exfoliated cells present in liquid-based cytology Pap test specimens and to compare the signature of high-grade dysplastic cells to each of the normal cell types. Raman spectra were recorded from single exfoliated cells and subjected to multivariate statistical analysis. The study demonstrated that Raman spectroscopy can identify biochemical signatures associated with the most common cell types seen in liquid-based cytology samples; superficial, intermediate, and parabasal cells. In addition, biochemical changes associated with high-grade dysplasia could be identified suggesting that Raman spectroscopy could be used to aid current cervical screening tests

Raman Spectroscopy of Liquid-Based Cervical Smear Samples as a Triage to Stratify Women Who Are HPV-Positive on Screening

Persistent high-risk human papillomavirus (HPV) infection can lead to cervical precancer and cancer. Recently, HPV testing has been introduced for primary cervical screening, but the HPV DNA test cannot distinguish between transient and persistent HPV infection. Thus, there is an unmet clinical need to develop a new test to identify women with a high-risk persistent HPV infection. Raman spectra were recorded from cervical smear samples (n = 60) and, on the basis of HPV DNA and HPV mRNA test results, a classifier was developed to identify persistent HPV infection. A further blinded independent test set (n = 14) was used to validate the model, and sensitivity of 90% and specificity of 100% were achieved. Improved triage would allow women with a high-risk persistent HPV infection to be referred for immediate treatment, while women with a low-risk transient infection could avoid overtreatment

Reducing dose for digital cranial radiography : The increased source to the image-receptor distance approach

This investigation proposes that an increased source to the image-receptor distance (SID) technique can be used to optimize occipital frontal and lateral cranial radiographs acquired with direct digital radiography. Although cranial radiography is not performed on a routine basis, it should nonetheless be optimized to keep the dose to the patient as low as reasonably achievable, particularly because it can form part of the facial bone and sinus series. Dose measurements were acquired at various SIDs, and image quality was assessed using visual grading analysis. Statistically significant reductions in the effective dose between 19.2% and 23.9% were obtained when the SID was increased from the standard 100 to 150 cm (P ≤.05), and visual grading analysis scores indicate that image quality remained diagnostically acceptable for both projections. This investigation concludes that increasing the SID effectively optimizes occipital frontal and lateral skull radiographs. Radiology departments must be advised of the benefits of this technique with the goal of introducing an updated reference SID of 150 cm into clinical practice.Peer reviewe

Phage-Encoded Cationic Antimicrobial Peptide Required for Lysis

Abstract: Most phages of Gram-negative bacteria hosts encode spanins for disruption of the outer membrane, which is the last step in host lysis. However, bioinformatic analysis indicates that ∼15% of these phages lack a spanin gene, suggesting they have an alternate way of disrupting the outer membrane (OM). Here, we show that the T7-like coliphage phiKT causes an explosive cell lysis associated with spanin activity despite not encoding spanins. A putative lysis cassette cloned from the phiKT late gene region includes the hypothetical novel gene 28 located between the holin and endolysin genes and supports inducible lysis in Escherichia coli K-12. Moreover, induction of an isogenic construct lacking gene 28 resulted in divalent cation-stabilized spherical cells rather than lysis, implicating gp28 in OM disruption. Additionally, gp28 was shown to complement the lysis defect of a spanin-null λ lysogen. Gene 28 encodes a 56-amino acid cationic protein with predicted amphipathic helical structure and is membrane-associated after lysis. Urea and KCl washes did not release gp28 from the particulate, suggesting a strong hydrophobic membrane interaction. Fluorescence microscopy supports membrane localization of the gp28 protein before lysis. The protein gp28 is similar in size, charge, predicted fold, and membrane association to the human cathelicidin antimicrobial peptide LL-37. Synthesized gp28 behaved similarly to LL-37 in standard assays mixing peptide and cells to measure bactericidal and inhibitory effects. Taken together, these results indicate that phiKT gp28 is a phage-encoded cationic antimicrobial peptide that disrupts bacterial outer membranes during host lysis and, thus, establishes a new class of phage lysis proteins, the disruptins. Importance: We provide evidence that phiKT produces an antimicrobial peptide for outer membrane disruption during lysis. This protein, designated a disruptin, is a new paradigm for phage lysis and has no similarities to other known lysis genes. Although many mechanisms have been proposed for the function of antimicrobial peptides, there is no consensus on the molecular basis of membrane disruption. Additionally, there is no established genetic system to support such studies. Therefore, the phiKT disruptin may represent the first genetically tractable antimicrobial peptide, facilitating mechanistic analyses

Seawater softening of suture zones inhibits fracture propagation in Antarctic ice shelves

Suture zones are abundant on Antarctic ice shelves and widely observed to impede fracture propagation, greatly enhancing ice-shelf stability. Using seismic and radar observations on the Larsen C Ice Shelf of the Antarctic Peninsula, we confirm that such zones are highly heterogeneous, consisting of multiple meteoric and marine ice bodies of diverse provenance fused together. Here we demonstrate that fracture detainment is predominantly controlled by enhanced seawater content in suture zones, rather than by enhanced temperature as previously thought. We show that interstitial seawater can reduce fracture-driving stress by orders of magnitude, promoting both viscous relaxation and the development of micro cracks, the incidence of which scales inversely with stress intensity. We show how simple analysis of viscous buckles in ice-penetrating radar data can quantify the seawater content of suture zones and their modification of the ice-shelf’s stress regime. By limiting fracture, enhancing stability and restraining continental ice discharge into the ocean, suture zones act as vital regulators of Antarctic mass balance

Live virtual placements: an alternative to traditional ‘in person’ placements

Background and aim: The role of the paramedic is diversifying, and universities need to respond by developing curriculums that support paramedic graduates to meet future workforce needs. Placements are key to our students developing the necessary competencies to become qualified paramedics and the pressure is on universities to offer a wide range of placements to reflect professional diversification. In addition, Health and Care Professions Council’s new standards of proficiency acknowledge that paramedics of the future are likely to consult patients in the virtual world [1]. As universities strive to meet this demand, they are often faced with placement capacity issues. Rising student numbers, staff retention issues and competition for placements from other healthcare students can make it extremely challenging to secure placements, especially in desirable areas such as primary care. Activity: The author, with the support from colleagues, was successful in obtaining funding from Health Education England to pilot a series of live virtual placement experiences, the first of which was successfully delivered on 20th April. On this date, 30 learners from our paramedic degree apprenticeship programme, in a classroom on our Lancaster campus, virtually attended a live clinic in a primary care setting in the south of England. The clinic was rigged with various cameras and microphones, with real patients consenting to being filmed. The experience comprised of 5 patients, with the lead clinician providing a brief to the learners before each patient arrived for their consultation. Afterwards, the clinician would complete their clinical documentation before engaging in a two-way conversation with our learners and academic staff via Microsoft teams. Following the clinic, our apprentices had the opportunity to consolidate their learning via case study driven seminars which linked to the mornings experience. Findings: Overall, student feedback was supportive, with the majority stating they found the experience enjoyable and engaging. The video stream of the placement was recorded for reuse in the programme’s curriculum, and we hope that future live virtual placements will see other professions, such as physiotherapy and nursing, take part. Eventually, we want to develop the model for other disciplines and placement settings Conclusion: The academic team are looking forward to the second of three experiences, in May, with the view to contributing to the growing evidence base in this area, to reflect the value that we believe ‘Live Virtual Placement’ experiences have in the development of our future workforce. Ethics statement: Authors confirm that all relevant ethical standards for research conduct and dissemination have been met. The submitting author confirms that relevant ethical approval was granted, if applicable. References: 1. Health and Care Professions Council [Internet]. 2023 [cited 2023 Apr 29]. Available from: https://www.hcpc-uk.org/globalassets/standards/standards-of-proficiency/reviewing/paramedics---new-standards.pd

Social disorganization and history of child sexual abuse against girls in sub-Saharan Africa : a multilevel analysis

Background: Child sexual abuse (CSA) is a considerable public health problem. Less focus has been paid to the role of community level factors associated with CSA. The aim of this study was to examine the association between neighbourhood-level measures of social disorganization and CSA. Methods: We applied multiple multilevel logistic regression analysis on Demographic and Health Survey data for 6,351 adolescents from six countries in sub-Saharan Africa between 2006 and 2008. Results: The percentage of adolescents that had experienced CSA ranged from 1.04% to 5.84%. There was a significant variation in the odds of reporting CSA across the communities, suggesting 18% of the variation in CSA could be attributed to community level factors. Respondents currently employed were more likely to have reported CSA than those who were unemployed (odds ratio [OR] = 2.05, 95% confidence interval [CI] 1.48 to 2.83). Respondents from communities with a high family disruption rate were 57% more likely to have reported CSA (OR=1.57, 95% CI 1.14 to 2.16). Conclusion: We found that exposure to CSA was associated with high community level of family disruption, thus suggesting that neighbourhoods may indeed have significant important effects on exposure to CSA. Further studies are needed to explore pathways that connect the individual and neighbourhood levels, that is, means through which deleterious neighbourhood effects are transmitted to individuals

Split operator method for fluorescence diffuse optical tomography using anisotropic diffusion regularisation with prior anatomical information

Fluorescence diffuse optical tomography (fDOT) is an imaging modality that provides images of the fluorochrome distribution within the object of study. The image reconstruction problem is ill-posed and highly underdetermined and, therefore, regularisation techniques need to be used. In this paper we use a nonlinear anisotropic diffusion regularisation term that incorporates anatomical prior information. We introduce a split operator method that reduces the nonlinear inverse problem to two simpler problems, allowing fast and efficient solution of the fDOT problem. We tested our method using simulated, phantom and ex-vivo mouse data, and found that it provides reconstructions with better spatial localisation and size of fluorochrome inclusions than using the standard Tikhonov penalty term

"It's a can of worms": understanding primary care practitioners' behaviours in relation to HPV using the Theoretical Domains Framework

Background: The relationship between infection with high-risk human papillomavirus (HPV) and cervical cancer is transforming cervical cancer prevention. HPV tests and vaccinations have recently become available. In Ireland, as elsewhere, primary care practitioners play a key role in prevention. ATHENS (A Trial of HPV Education and Support) aims to develop a theorybased intervention to support primary care practitioners in their HPV-related practice. This study, the first step in the intervention development process, aimed to: identify HPV-related clinical behaviours that the intervention will target; clarify general practitioners’ (GPs’) and practice nurses’ roles and responsibilities; and determine factors that potentially influence clinical behaviour. A secondary objective was to informally assess the utility of the Theoretical Domains Framework (TDF) in understanding clinical behaviours in an area with an evolving evidence-base. Methods: In-depth semi-structured telephone interviews were conducted with GPs and practice nurses. The topic guide, which contained open questions and HPV-related clinical scenarios, was developed through literature review and clinical experience. Interview transcripts were content-analysed using the TDF as the coding framework. Results: 19 GPs and 14 practice nurses were interviewed. The major HPV-related clinical behaviours were: initiating a discussion about HPV infection with female patients; offering/recommending HPV vaccination to appropriate patients; and answering patients’ questions about HPV testing. While the responsibility for taking smears was considered a female role, both male and female practitioners dealt with HPV-related issues. All 12 theoretical domains arose in relation to HPV infection; the domains judged to be most important were: knowledge, emotion, social influences, beliefs about capabilities and beliefs about consequences. Eleven domains emerged in relation to HPV vaccination, with beliefs about consequences, social influences, knowledge and environmental context and resources judged to be the most important. Nine domains were relevant to HPV testing, with knowledge and beliefs about capabilities judged to be the most important. Conclusions: The findings confirm the need for an intervention to support primary care practitioners around HPV and suggest it should target a range of theoretical domains. The TDF proved valuable in analysing qualitative data collected using a topic guide not specifically designed to capture TDF domains and understanding clinical behaviours in an area with an evolving evidence-base