77 research outputs found

    Quantification of Cellular Proliferation in Acne Using the Monoclonal Antibody Ki-67

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    The mechanism by which ductal hypercornification occurs in acne is uncertain. We investigated proliferation in normal and acne follicles and in the interfollicular epidermis using the monoclonal antibody Ki-67, which reacts with a nuclear antigen expressed by cells in the G1, S, M, and G2 phases of the cell cycle. Cryostat sections of biopsies from the interscapular region from acne patients and from normal volunteers were stained with Ki-67 antibody and counterstained with 2% methyl green. The number of Ki-67-positive nuclei in the basal layer were counted and expressed as a percentage of the total number of basal nuclei in the ductal or interfollicular epithelia. The data was expressed as mean percent ± SD. In normal follicles from acne-affected sites 17.40% ± 1.86% (n = 8) of the nuclei were Ki-67 positive. This was significantly higher (p <0.01) than follicles from an area of skin unaffected by acne (11.01% ± 6.16%, n = 8). In the follicular epithelia of non-inflamed lesions, the percentage of Ki-67 positive nuclei was 23.44% ± 8.36% (n = 15). It was impossible to count the nuclei of follicular epithelium of inflamed lesions because little of this remained intact. In normal interfollicular epidermis, Ki-67-positive nuclei represented 5.33% ± 3.36% (n = 8) of the total. This value was not significantly different from the value obtained for interfollicular epidermis near non-inflamed lesions (10.46% ± 4.45%, n = 15). However, the number of Ki- 67-positive nuclei in the interfollicular epidermis near inflamed lesions was significantly higher than either of these two values: 25.26% ± 6.83%, n = 13, p < 0.05. Our results with Ki-67 confirm that ductal hyperproliferation occurs in acne and shows that normal follicles from acne skin may be “acne-prone.

    Separation and recovery of materials from scrap printed circuit boards

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    Printed circuit boards from waste computers, televisions, and mobile phones were pyrolysed in a fixed bed reactor with the aim of separating and recovering the organic and metallic materials. A selection of printed circuit boards from each of the three waste classes was pyrolysed at 800°C and the pyrolysis products were analysed using GC-FID, GC-TCD, GC-MS, GC-ECD, ICP-MS, and SEM-EDX. The pyrolysis oils contained high concentrations of phenol, 4-(1-methylethyl)phenol, and p-hydroxyphenol, as well as bisphenol A, tetrabromobisphenol A, methyl phenols, and bromophenols. The pyrolysis oils also contained significant concentrations of organo – phosphate compounds and a number of tetrabromobisphenol A pyrolysis products were also identified. The pyrolysis residues were very fragile and the organic, glass fibre, and metallic fractions could easily be separated and the electrical components could easily be removed from the remains of the printed circuit boards. The ash in the residue mainly consisted of copper, calcium, iron, nickel, zinc, and aluminium, as well as lower concentrations of valuable metals such as gallium, bismuth, silver, and gold, silver was present in particularly high concentrations. Many other metals were also identified in the ash by ICP-MS and SEM EDX. The pyrolysis gases mainly consisted of CO2 and CO but all of the C1 – C4 alkanes and alkenes were present, as were some inorganic halogens

    Opportunities for improving animal welfare in rodent models of epilepsy and seizures

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    Animal models of epilepsy and seizures, mostly involving mice and rats, are used to understand the pathophysiology of the different forms of epilepsy and their comorbidities, to identify biomarkers, and to discover new antiepileptic drugs and treatments for comorbidities. Such models represent an important area for application of the 3Rs (replacement, reduction and refinement of animal use). This report provides background information and recommendations aimed at minimising pain, suffering and distress in rodent models of epilepsy and seizures in order to improve animal welfare and optimise the quality of studies in this area. The report includes practical guidance on principles of choosing a model, induction procedures, in vivo recordings, perioperative care, welfare assessment, humane endpoints, social housing, environmental enrichment, reporting of studies and data sharing. In addition, some model-specific welfare considerations are discussed, and data gaps and areas for further research are identified. The guidance is based upon a systematic review of the scientific literature, survey of the international epilepsy research community, consultation with veterinarians and animal care and welfare officers, and the expert opinion and practical experience of the members of a Working Group convened by the United Kingdom's National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs)

    Prospective observational study of SARS-CoV-2 infection, transmission and immunity in a cohort of households in Liverpool City Region, UK (COVID-LIV): a study protocol

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    Introduction The emergence and rapid spread of COVID-19 have caused widespread and catastrophic public health and economic impact, requiring governments to restrict societal activity to reduce the spread of the disease. The role of household transmission in the population spread of SARS-CoV-2, and of host immunity in limiting transmission, is poorly understood. This paper describes a protocol for a prospective observational study of a cohort of households in Liverpool City Region, UK, which addresses the transmission of SARS-CoV-2 between household members and how immunological response to the infection changes over time. Methods and analysis Households in the Liverpool City Region, in which members have not previously tested positive for SARS-CoV-2 with a nucleic acid amplification test, are followed up for an initial period of 12 weeks. Participants are asked to provide weekly self-throat and nasal swabs and record their activity and presence of symptoms. Incidence of infection and household secondary attack rates of COVID-19 are measured. Transmission of SARS-CoV-2 will be investigated against a range of demographic and behavioural variables. Blood and faecal samples are collected at several time points to evaluate immune responses to SARS-CoV-2 infection and prevalence and risk factors for faecal shedding of SARS-CoV-2, respectively. Ethics and dissemination The study has received approval from the National Health Service Research Ethics Committee; REC Reference: 20/HRA/2297, IRAS Number: 283 464. Results will be disseminated through scientific conferences and peer-reviewed open access publications. A report of the findings will also be shared with participants. The study will quantify the scale and determinants of household transmission of SARS-CoV-2. Additionally, immunological responses before and during the different stages of infection will be analysed, adding to the understanding of the range of immunological response by infection severity

    Investigation of SARS-CoV-2 faecal shedding in the community: a prospective household cohort study (COVID-LIV) in the UK

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    Background SARS-CoV-2 is frequently shed in the stool of patients hospitalised with COVID-19. The extent of faecal shedding of SARS-CoV-2 among individuals in the community, and its potential to contribute to spread of disease, is unknown. Methods In this prospective, observational cohort study among households in Liverpool, UK, participants underwent weekly nasal/throat swabbing to detect SARS-CoV-2 virus, over a 12-week period from enrolment starting July 2020. Participants that tested positive for SARS-CoV-2 were asked to provide a stool sample three and 14 days later. In addition, in October and November 2020, during a period of high community transmission, stool sampling was undertaken to determine the prevalence of SARS-CoV-2 faecal shedding among all study participants. SARS-CoV-2 RNA was detected using Real-Time PCR. Results A total of 434 participants from 176 households were enrolled. Eighteen participants (4.2%: 95% confidence interval [CI] 2.5–6.5%) tested positive for SARS-CoV-2 virus on nasal/throat swabs and of these, 3/17 (18%: 95% CI 4–43%) had SARS-CoV-2 detected in stool. Two of three participants demonstrated ongoing faecal shedding of SARS-CoV-2, without gastrointestinal symptoms, after testing negative for SARS-CoV-2 in respiratory samples. Among 165/434 participants without SARS-CoV-2 infection and who took part in the prevalence study, none had SARS-CoV-2 in stool. There was no demonstrable household transmission of SARS-CoV-2 among households containing a participant with faecal shedding. Conclusions Faecal shedding of SARS-CoV-2 occurred among community participants with confirmed SARS-CoV-2 infection. However, during a period of high community transmission, faecal shedding of SARS-CoV-2 was not detected among participants without SARS-CoV-2 infection. It is unlikely that the faecal-oral route plays a significant role in household and community transmission of SARS-CoV-2

    Multiomics in the central Arctic Ocean for benchmarking biodiversity change

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    Multiomics approaches need to be applied in the central Arctic Ocean to benchmark biodiversity change and to identify novel species and their genes. As part of MOSAiC, EcoOmics will therefore be essential for conservation and sustainable bioprospecting in one of the least explored ecosystems on Earth
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