289 research outputs found

    Eosinophilic dysplasia of the gallbladder: a hitherto undescribed variant identified in association with a "porcelain" gallbladder

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    Non-mass forming, neoplastic intraepithelial proliferations (dysplasia) represent the most well-accepted precursor lesions to gallbladder adenocarcinomas. They are typically small, localized, grossly unrecognizable lesions that have been identified in the epithelium adjacent to up to 79% of gallbladder adenocarcinomas. Morphologic variants that have been reported include flat, micropapillary, papillary and cribriform. We have recently encountered a morphologically distinctive, previously unreported lesion to which we have applied the designation eosinophilic dysplasia. This lesion was identified in a gallbladder with diffuse mural fibrosis and calcification (porcelain gallbladder). The dysplastic focus was confined to one tissue section, and was comprised of a localized true papilla [i.e with a fibrovascular core], measuring approximately 1.2 mm in greatest dimension and an adjacent, flat, 7-cell epithelial segment. These foci were lined by cells displaying significant nuclear enlargement [1.5–4 times the adjacent benign cells], nuclear pleomorphism, occasional multinucleation, hyperchromasia and nuclear membrane irregularities. Nucleoli were present but inconspicuous. These cells also showed voluminous eosinophilic to granular cytoplasm, such that the overall nuclear-to-cytoplasmic ratio was generally not increased. The cells displayed diffuse and marked nuclear immunoreactivity for p53, and approximately 70% of the cells showed nuclear positivity for Ki-67. The cells were also positive for cytokeratin 7 and were entirely negative for carcinoembryonic antigen (CEA) and chromogranin A. The cells of the adjacent normal epithelium were positive for cytokeratin 7 and CEA, negative for p53 and chromogranin A and showed a Ki-67 labeling index of <10%. Marked overexpression of the p53 protein as well as its high proliferative index are strong arguments in favor of the dysplastic nature of this lesion. However, further studies are required to elucidate its true clinical significance and to determine whether or not its association with a porcelain gallbladder, as noted herein, is entirely fortuitous. However, such studies can only be performed with an increased recognition by practitioners of this distinctive variant

    Neural network controller for active demand side management with PV energy in the residential sector

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    In this paper, we describe the development of a control system for Demand-Side Management in the residential sector with Distributed Generation. The electrical system under study incorporates local PV energy generation, an electricity storage system, connection to the grid and a home automation system. The distributed control system is composed of two modules: a scheduler and a coordinator, both implemented with neural networks. The control system enhances the local energy performance, scheduling the tasks demanded by the user and maximizing the use of local generation

    DEVELOPMENT AND APPLICATION OF A MACHINE VISION SYSTEM FOR MEASUREMENT OF TOOL WEAR

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    ABSTRACT Tool wear measurement is of great concern in machining industry, as it affects the surface qualities, dimensional accuracy and production costs of the machined components. The orthodox methods of measuring tool wear are time consuming and limited in accuracy and application. In this study, machine vision system based on digital image processing was developed for measurement of tool wear. The basic components of the system are: a charge coupled device (CCD) camera, PC, Microsoft Windows Video Maker, frame grabber, Video to USB cable, digital image processing software (Photoshop and digital image processing toolbox for MATLAB), multi-directional insert fixture, and light source. Tool wear images were captured and ten different wear features: length, width, area, equivalent diameter, centroid, major axis length, minor axis length, solidity, eccentricity and orientation were extracted from the images. The pixels dimension of the system was found to be PB B x B B = 0.03306 and PB B y B B = 0.03333. The accuracy of the system compared to SANDVIK CoromantP P P Phand-held microscopic lens was found to have an absolute error less than 3.13%. The system has been applied in the analysis of tool wear of uncoated cemented carbide inserts used for turning of NST 37.2 steel. A tool wear index (TWI) was proposed as a potential indicator for tool wear monitoring. A graphical user interface (GUI) was designed for easy application of system

    Activities across Africa to improve antimicrobial utilisation and reduce AMR

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    There are concerns with current prescribing and dispensing of antimicrobials in Africa. Point prevalence studies in hospitals shown variable rates with high rates HIV in some. Variable ASPs, extended prophylaxis and high rates self purchasing in some

    Microparticles and microplastics contamination in African table salts

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    Staff PublicationThe presence of micro/plastic particles has been reported in various seafood products. However, information on microplastics contamination in salts from African continent is very limited. This study analysed 23 brands of table salts from 8 African countries for microplastics using microscopic/spectroscopic techniques. South Africa showed the highest microplastics concentration (0–1.33 ± 0.32 particles/kg), Nigeria, Cameroun, and Ghana (0–0.33 ± 0.38 particles/kg each); characterized as polyvinyl acetate, polypropylene, and polyethylene. Other countries have no detectable microplastics at 0.3 μm filter pore size. To our best knowledge, this is the first study to characterize micro-fibres/plastics in table salts across African countries, confirming that it is an emission source of micro-fibres/plastics into the human food chain, highlighting the overarching need to understand their effects on human health

    Exploring the acceptability of Option B plus among HIV-positive Nigerian women engaged and not engaged in the prevention of mother-to-child transmission of HIV cascade: a qualitative study

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    The acceptability of lifelong antiretroviral therapy (ART) among HIV-positive women in highburden Nigeria, is not well-known. We explored readiness of users and providers of prevention of mother-to-child transmission of HIV (PMTCT) services to accept lifelong ART -before Option B plus was implemented in Nigeria. We conducted 142 key informant interviews among 100 PMTCT users (25 pregnant-newly-diagnosed, 26 pregnant-in-care, 28 lost-to-follow-up (LTFU) and 21 postpartum women living with HIV) and 42 PMTCT providers in rural North-Central Nigeria. Qualitative data were manually analyzed via Grounded Theory. PMTCT users had mixed views about lifelong ART, strongly influenced by motivation to prevent infant HIV and by presence or absence of maternal illness. Newly-diagnosed women were most enthusiastic about lifelong ART, however postpartum and LTFU women expressed conditionalities for acceptance and adherence, including minimal ART side effects and potentially serious maternal illness. Providers corroborated user findings, identifying the postpartum period as problematic for lifelong ART acceptability/adherence. Option B plus scale-up in Nigeria will require proactively addressing PMTCT user fears about ART side effects, and continuous education on long-term maternal and infant benefits. Structural barriers such as the availability of trained providers, long clinic wait times and patient access to ART should also be addressed.Keywords: Nigeria; HIV; adherence; Option B plus; PMTCT; rura

    Dysplastic Ichthyosis Uteri-like changes of the entire endometrium associated with a squamous cell carcinoma of the uterine cervix

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    Ichthyosis uteri is an exceedingly rare condition in which the entire surface of the endometrium is replaced by stratified squamous epithelium. Originally described as an endometrial response to iatrogenically-introduced caustic substances, similar changes have since been described in association with a variety of inflammatory conditions of the endometrium. We describe herein a heretofore undescribed example of a moderately differentiated squamous cell carcinoma of the uterine cervix associated with extensive ichthyosis uteri-like changes of the entire adjacent endometrium. Additionally, the squamous epithelium of the latter also showed multifocal changes diagnostic of a low-grade squamous intraepithelial lesion. The potential genesis of this composite of findings is discussed, as is the neoplastic potential of ichthyosis uteri. It is concluded that a squamous cell carcinoma of the cervix extended proximally into the endometrium, and that there was a colonization of a pre-existing ichthyosis uteri by associated human papillomavirus. The possibility of significant cervical pathology should be considered when plaques of squamous epithelium with low grade dysplastic changes are identified in an endometrial biopsy or curettage

    Malignant perivascular epithelioid cell tumor of the uterus

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    Perivascular epithelioid cell tumors (PEComas) are a rare collection of tumors arising in a wide array of anatomic locations and characterized by a myomelanocytic phenotype. PEComas which occur in non-classic anatomic distributions are known as perivascular epithelioid cell tumor-not otherwise specified (PEComa-NOS), and one of the most common primary sites for PEComa-NOS is the uterus. The risk of aggressive behavior of these tumors has been linked to a number of factors evaluable on pathologic review following initial surgical resection. We report a case of PEComa-NOS of the uterus with multiple high-risk features, including frank vascular invasion, with no evidence of recurrent disease 18 months following initial surgical resection

    Comparative Study of Some Histological Features in the Pancreas of Some Mammals Having Different Feeding Habits

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    Background: Mammals\u27 endocrine and exocrine systems depend heavily on the pancreas, which aids in functions including digestion and blood sugar management. The pancreas may have differences in histological structure that reflect adaptations to various dietary habits, even though its functional responsibilities are comparable across species. These differences can shed light on the functional and evolutionary connections between pancreatic shape and nutrition. Objective: This study aims to compare the histological features of the pancreas, body weight, and blood glucose level in some mammals with different feeding habits. Methodology: Ten female pangolins, rabbits, and rats each were studied. Body weight and fasting blood glucose levels were measured. The pancreas was harvested post-sacrifice and analysed histologically using Hematoxylin and Eosin, Masson’s Trichrome, Von Gieson, and Gomori aldehyde fuchsin stains to evaluate endocrine and exocrine structures. Results: Rabbits had the highest body (1975±66.2) and blood glucose levels (662.9±6.153), followed by pangolins (1327±48.01)(116.6±6.806) and rats (215.3±6.648) (121.1±6.873). Pangolins had the heaviest pancreas in absolute terms (1.930±0.068), while rats showed the highest relative pancreatic weight (0.0050±0.0) p value &lt; 0.01. Histologically, pangolins exhibited compact acinar architecture with indistinct islets of Langerhans. Rabbits showed loosely organised acini with poorly defined islets, while rats had clearly delineated islets and well-structured lobules. Conclusion: The observed structural and physiological differences in the pancreas across species reflect dietary specialisation and metabolic demands. Pangolins exhibit a predominantly exocrine pancreas adapted to a protein-rich insectivorous diet, while rats and rabbits demonstrate mixed pancreatic features aligned with their respective feeding habits. &nbsp; Keywords: pancreas,&nbsp
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