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Background: Alcohol use is a concerning issue for the military given its potential negative impact on human performance. Limited data are available regarding the incidence of alcohol use disorder in the military, which is critical to understand to evaluate force readiness, as well as for preventative initiatives and treatment planning. The aim was to examine the alcohol use disorder incidence rates (overall and across demographics) among active duty service members from 2001 to 2018. Methods: Data on 208,870 active duty service members between 2001 and 2018 from the Defense Medical Epidemiology Database was examined. Incidence rates were analyzed to determine the diagnostic rates of AUD (including both alcohol abuse and dependence), which were then examined by sex, age, service branch, military pay grade, marital status, and race. Results: Incidence rates of AUD in active duty service members (per 1,000 service members) ranged from 6.45 to 10.50 for alcohol abuse and 5.21 to 7.11 for alcohol dependence. Initial diagnoses of new-onset AUD occurred most frequently within 20-24 year-old, white, male, and non-married U.S. Army service members in the enlisted pay grades of E-1 to E-4. Statistically significant differences (p <.001) were found between observed and expected counts across all examined demographic variables. Conclusions: To our knowledge, this is the first study to provide a comprehensive examination of AUD incidence rates in an active-duty military population over an extended 18-year period and during the last decade. Incidence rates were higher than expected for alcohol dependence and lower than expected for alcohol abuse. Given the untoward effects of AUD on overall health and force readiness, active-duty service members may benefit from more advanced preventative interventions to decrease incidence rates of AUD over time. Future research should use these data to develop targeted interventions for the demographics at greatest risk.
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Alcoolismo , Militares , Adulto , Consumo de Bebidas Alcoólicas , Alcoolismo/epidemiologia , Humanos , Incidência , Masculino , Estado Civil , Estados Unidos/epidemiologia , Adulto JovemRESUMO
BACKGROUND: The first UK guidelines for the management of hidradenitis suppurativa (HS) were published by the British Association of Dermatologists (BAD) in 2018. The guidelines contained a set of audit criteria. AIM: To evaluate current HS management against the audit standards in the BAD guidelines. METHODS: BAD members were invited to complete audit questionnaires between January and May 2020 for five consecutive patients with HS per department. RESULTS: In total, 88 centres participated, providing data for 406 patients. Disease staging using the Hurley system and disease severity using a validated tool during follow-ups was documented in 75% and 56% of cases, respectively, while quality of life and pain were documented in 49% and 50% of cases, respectively. Screening for cardiovascular disease risk factors was as follows: smoking 75%, body mass index 27% and others such as lipids and diabetes 57%. Screening for depression and anxiety was performed in 40% and 25% of cases, respectively. Support for smokers or obese patients was documented in 35% and 23% of cases. In total, 182 patients were on adalimumab, of whom 68% had documentation of baseline disease severity, and 76% were reported as having inadequate response or contraindications to systemic treatments; 44% of patients continued on adalimumab despite having < 25% improvement in lesion count. CONCLUSION: UK dermatologists performed well against several audit standards, including documenting disease staging at baseline and smoking status. However, improvements are needed, particularly with regard to screening and management of comorbidities that could reduce the long-term complications associated with HS. A re-audit is required to evaluate changes in practice in the future.
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Auditoria Clínica , Hidradenite Supurativa/diagnóstico , Hidradenite Supurativa/tratamento farmacológico , Adalimumab/uso terapêutico , Anti-Infecciosos Locais/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Índice de Massa Corporal , Fármacos Dermatológicos/uso terapêutico , Fidelidade a Diretrizes , Hidradenite Supurativa/complicações , Humanos , Guias de Prática Clínica como Assunto , Qualidade de Vida , Fatores de Risco , Índice de Gravidade de Doença , Fumar/efeitos adversos , Tetraciclinas/uso terapêutico , Reino UnidoRESUMO
BACKGROUND: We conducted a re-audit of the surgical practice of UK dermatologists for the treatment of nonmelanoma skin cancer and examined changes with reference to our previous audit in 2014. The audit was supplemented by a detailed assessment of completeness of the histopathology reports for each tumour. METHODS: UK dermatologists collected data on 10 consecutive nonmicrographic excisions for basal cell carcinoma (BCC) and 5 for squamous cell carcinoma (SCC). Data were collected on site, preoperative diagnosis, histological diagnosis, proximity to previous scars, and histological deep and peripheral margins. RESULTS: In total, 222 responses were received from 135 centres, reporting on 3290 excisions. Excisions from the head and neck accounted for 56.7% of cases. Tumour diameter (mean ± SD) was 11.4 ± SD 7.1 mm (maximum size 100 mm) and 97% of cases were primary excisions. BCCs and SCCs respectively accounted for 65.7% and 26.8% of total cases. Of the suspected BCCs and SCCs, 95.8% and 80.4%, respectively, were confirmed histologically. All margins for any tumour were clear in 97.0% of cases, and complication rate in the audit was < 1%. Of the 2864 histology reports evaluated, only 706 (24.6%) contained all core data items; 95% of these were structure (synoptic) reports. Commonly omitted items were level of invasion, risk and T stage, which were absent from 35.7%, 64.2% and 44.1% of reports, respectively. CONCLUSIONS: Diagnostic accuracy and complete excision rates remain high. Complication rates may be under-reported owing to lack of follow-up. Histopathology reporting has a greater chance of being complete if reports are generated on a field-based platform (synoptic reporting).
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Dermatologistas , Patologistas , Padrões de Prática Médica/estatística & dados numéricos , Neoplasias Cutâneas/cirurgia , Carcinoma Basocelular/cirurgia , Carcinoma de Células Escamosas/cirurgia , Auditoria Clínica , Procedimentos Cirúrgicos Dermatológicos/estatística & dados numéricos , Margens de Excisão , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia , Sociedades Médicas , Reino UnidoRESUMO
BACKGROUND: In 2010, the British Association of Dermatologists (BAD) published clinical guidelines for the safe introduction and continued use of isotretinoin in patients with acne in the UK. The BAD provides UK dermatologists with a facility for national audit, and it undertook an audit on compliance with these guidelines in 2012. AIM: To determine current clinical practices relating to use of isotretinoin among dermatologists in the UK (including geographical variations) as measured against BAD standards, and to ascertain any improvement since the 2012 audit. METHODS: The 2012 isotretinoin audit proforma was used, with additional questions on clinical setting, complaints and litigation. A web-based survey tool was used for data entry and submission, with email invitation to working, UK-based BAD members (n = 1226) in December 2013 and weekly reminders during the 8.5-week data collection period. Responders were requested to enter data for the three most recent consecutive patients (including one male and one female patient) who had completed treatment within the previous 6 months. RESULTS: In total, 338 (27.6%) respondents provided data on 1013 patients. Serum lipids were checked in 93.4% of patients and documentation of mental health and/or mood state was recorded in 82.1%. Regarding the Pregnancy Prevention Programme (PPP), 91.6% of female patients of childbearing potential had signed the PPP information form, while 93.3% who had followed the PPP had taken pregnancy tests both before and during treatment, and 54.7% had taken a pregnancy test 5 weeks post-treatment. CONCLUSION: Overall, there is currently good compliance with standards. Certain aspects of care that are less frequently preformed, such as pregnancy testing post-treatment, are highlighted.
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BACKGROUND: Diagnosis and management of nonmelanoma skin cancer (NMSC) represents a large part of the dermatology workload, and complete excision is a required surgical standard for treatment. AIM: To conduct an audit of the surgical practice for the treatment of NMSC by dermatologists in the UK. METHODS: Data on 10 consecutive nonmicrographic excisions of nonmelanoma skin cancer by UK dermatologists. Data collected included site, preoperative diagnosis, histological diagnosis, proximity to previous scars, and histological deep and peripheral margins. RESULTS: A total of 227 responses from 135 centres reported 2739 excisions. Excisions on the head and neck accounted for 58.3% of cases. Tumour diameter (mean ± SD) was 10.61 ± 6.9 mm (maximum 130 mm), and 96.7% of cases were primary excisions, with 3.3% being re-excisions. Basal cell carcinomas (BCCs) accounted for 79.1% (n = 2167) of the total cases and squamous cell carcinomas (SCCs) for 17.9% n = 491). Of the suspected BCCs and SCCS, 94.4% (n = 2045) and 66.8% (328), respectively, were confirmed histologically to be the respective carcinomas. Similar proportions of BCC and SCC cases were within 10 mm of a previous excision. Lateral and deep margins were clear in 98.3% and 99.2% of BCC cases, respectively, and in 98.4% and 97.1% of SCC cases, respectively. Reported surgical complication rate in the audit was 3.4%. CONCLUSIONS: The majority of excisions for NMSC are for BCC and SCC. Our figures for diagnostic accuracy are at the upper range of previously published figures. Most patients were not followed up in secondary care, hence complication rates may be under-reported.
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Auditoria Clínica/métodos , Procedimentos Cirúrgicos Dermatológicos , Dermatologia , Inoculação de Neoplasia , Encaminhamento e Consulta , Neoplasias Cutâneas/cirurgia , Sociedades Médicas , Diagnóstico Diferencial , Humanos , Melanoma , Prevalência , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/epidemiologia , Reino Unido/epidemiologiaRESUMO
To investigate the seasonal changes in physiological and psychological parameters of stress in collegiate swimmers. Fifteen NCAA Division I swimmers (8 men) participated in a tethered anaerobic swim test to determine physiological responses in an ecologically-relevant, graded exercise test. Wisconsin Upper Respiratory Symptom Survey (WURSS-21), Activation-Deactivation Adjective Check List (AD-ACL), Daily Analysis of Life Demands of Athletes (DALDA), and Pittsburgh Sleep Quality Index were assessed at post-season in April (V1), the end of off-season in June (V2), and pre-season in October (V3). The percent change was determined from V2-V1 (off-season phase), V3-V2 (pre-season phase), V1-V3 (in-season phase). Spearman's rho correlation was used to examine associations between change in physiological and psychological outcomes. All data results showed a better swim performance occurred at V2. Men tended to have faster speed (p = 0.07) in fewer strokes (p = 0.10) and greater work per stroke (p = 0.10) at V2 than V1. Women were faster during V2 compared to V1 (p = 0.02) and V3 (p = 0.05). Women had fewer strokes (p = 0.02) and greater work per stroke (p = 0.01) at V2 compared to V3. Women had the lowest HR and lactate concentration at V3 compared to other visits (p < 0.05). During the in-season phase, swim speed decreased the greatest extent and stress sources and symptoms assessed by DALDA had greatest elevation (p < 0.05). An increased in stress sources and symptoms assessed by DALDA was associated with an increase in upper respiratory illness from WURSS-21 (rho = 0.44, p = 0.009), being less energetic (rho = - 0.35, p = 0.04) and greater tension state (rho = 0.49, p = 0.003; AD-ACL), and a decrease in swim speed (rho =- 0.38, p = 0.03). Swim performance peaked at off-season when psychological stress was at its lowest. The relationship between DALDA scores with psychological parameters and swim performance suggested physiological and psychological parameters of stress is an important aspect to avoid overtraining when approaching high swim performance.
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Teste de Esforço , Masculino , Humanos , Feminino , Estações do Ano , Inquéritos e Questionários , WisconsinRESUMO
BACKGROUND: Increasingly women at high risk of breast cancer are opting for risk reducing surgery. The aim of this study was to assess the effectiveness of this approach in women at high risk in both carriers and non-carriers of BRCA1/2. METHODS: Data from 10 European centres that offer a genetic counselling and screening service to women at risk were obtained prospectively from 1995. Breast cancer risks were estimated from life tables and a control group of women at risk who did not undergo surgery. RESULTS: The combined centres have data on 550 women who have undergone risk reducing mastectomy with greater than 3334 women years of follow-up. Operations were carried out on women with lifetime risks of 25-80%, with an average expected incidence rate of 1% per year. No breast cancers have occurred in this cohort in the "at risk" unaffected breast, whereas >34 would have been expected. A high rate (2-3.6%) of occult disease was identified in the at risk breast at the time of surgery. INTERPRETATION: We conclude that risk reducing surgery is highly effective.
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Neoplasias da Mama/cirurgia , Mastectomia/métodos , Adulto , Idoso , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Aconselhamento Genético , Testes Genéticos , Humanos , Incidência , Pessoa de Meia-Idade , Ovariectomia , Fatores de Risco , Adulto JovemAssuntos
Máscaras Laríngeas , Manometria , Faringite/prevenção & controle , Padrão de Cuidado , Humanos , PressãoRESUMO
BACKGROUND: The perception of choice in becoming a caregiver may impact on caregiver psychological and physical health. We determined the proportion of spousal dementia caregivers who felt they had a choice, and examined whether lack of choice in taking up the caregiving role and the perceived degree of choice in caregiving predicted caregiver health and wellbeing and care-recipient placement in long-term care at 1-year follow-up. METHODS: We performed secondary analyses of data from DeStress, a longitudinal study of 251 spousal dementia caregivers in Ireland. We used multivariate logistic and linear regression analyses to examine whether lack of choice (a dichotomous item) and/or the perceived degree of choice (a 9-point scale) at baseline predicted caregiver health (number of chronic health conditions; self-reported health) and wellbeing (e.g., burden, anxiety, depression, stress, and positive aspects of caregiving) and care status (continued care at home or placement in long-term care) at follow-up. RESULTS: The vast majority of caregivers (82%) reported that they had no choice in taking up the caregiving role. Nevertheless, nearly three-quarters (74%) responded above the midpoint on the rating scale (Mean = 6.82, SD = 3.22; Median = 9; Mode = 9), indicating they provided care voluntarily. Caregivers who reported a greater degree of choice were more likely to still be providing care at home at follow-up and to identify benefits from providing care. Neither choice nor degree of choice predicted any other caregiver outcomes. CONCLUSION: For the vast majority of spousal dementia caregivers, taking up the caregiving role is not perceived as a choice; yet, most report performing this role voluntarily. Thus, facilitating greater choice may not necessarily diminish the key contribution family caregivers make to the care system. Although we found no evidence that caregiver choice predicted more positive caregiver health and wellbeing, the perception of choice is important in and of itself, and may benefit caregivers by facilitating the identification of positive aspects of care and be a factor in delaying care-recipient placement in long-term care. Future research should be especially mindful of how caregiver choice is assessed and how this may affect the resulting prevalence of choice.
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The ultrastructure of thylakoid membranes from Arabidopsis thaliana wild-type, JB67 and LK3 fatty acid desaturation deficient mutants was studied by thin-section and freeze-fracture electron microscopy. There was a decrease in the amount of the appressed and non-appressed membranes in JB67 and LK3 Arbidopsis mutants when compared to the wild type, resulting in a reduction in the length of photosynthetic membrane per plastid. The results from freeze-fracture showed a decrease in size and a marked increase in packing density of membrane-associated particles on the exo- and endoplasmic fracture faces of the mutants. In addition, areas of the appressed membranes of the mutants contained particles in regular arrays under conditions where no such arrays were observed in wild-type thylakoid membranes. These observations suggest, that the decreased level of lipid fatty acid unsaturation affects the ability of the lipid matrix to mediate the assembly of chloroplast membrane components. The role of polyunsaturated membrane lipids is considered in terms of their ability to promote functional oligomeric assemblies of components of the photosynthetic apparatus.
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Arabidopsis/química , Ácidos Graxos Insaturados/análise , Arabidopsis/genética , Membrana Celular/ultraestrutura , Cloroplastos/ultraestrutura , Técnica de Fratura por Congelamento , Microscopia Eletrônica , Mutação , Tamanho da PartículaRESUMO
The low temperature phase properties of aqueous dispersions of di-18:2 and di-18:3 phosphatidylethanolamine are strongly influenced by the presence of ice. In the presence of cryoprotectants to inhibit ice formation, these lipids persist in the H(II) phase down to at least -50 degrees C. Ice formation, however, leads to a drastic reduction in the amount of available free water and a rapid reduction in the diameter of the inverted cylindrical micelles of the H(II) phase. The resulting increase in surface curvature of the micelles induces an imbalance in the forces acting in the lipid surface and the hydrophobic core which is relieved by formation of the L(alpha) phase. On reheating the lipid samples undergo an abrupt L(alpha) --> H(II) phase transition at about -20 degrees C. The radius of the water core of the inverted micelles at their point of formation is estimated to be 0.9 nm. This increases with temperature as more unfrozen water becomes available until the normal equilibrium radius of about 2.3 nm is reached at 0 degrees C when the bulk water in the sample finally melts. A small proportion of the H(II) phase lipid enters an as yet unidentified cubic phase on freezing. The spacings of the (10) planes of the H(II) phase, the (111) planes of the cubic phase and the d-spacing of the L(alpha) phase were found to be almost identical at the phase transition temperature. The cubic phase appears to disappear at low temperature but to reform on heating. Freeze-fracture studies revealed no unequivocal evidence for cubic phase lipid but the presence of residual non-bilayer lipid structures was observed even at temperatures as low as -80 degrees C. The presence of intersecting stacks of lamellar sheets in the replicas strongly suggest the existence of an epitaxial relationship between the L(alpha) and H(II) phases in these systems.
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Bicamadas Lipídicas/química , Lipídeos de Membrana/química , Fosfatidiletanolaminas/química , Polienos/química , Técnica de Fratura por Congelamento , Microscopia Eletrônica , Água , Difração de Raios XRESUMO
Freeze fracture electron microscopy studies were performed on samples of Anacystis nidulans quenched from different temperatures. Membrane lipid phase separations were observed to take place over the ranges 15--30 degrees C, 5--25 degrees C and -5--15 degrees C for cultures grown at 38, 28 and 18 degrees C, respectively. Differential scanning calorimetry heating curves showed endotherms which coincided with these temperature ranges. Variations of phase separation temperatures with growth temperature, and hysteresis effects in the calorimetric measurements, were related to changes in the fatty acid composition of membrane lipids.
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Membrana Celular/ultraestrutura , Cianobactérias/ultraestrutura , Fracionamento Celular/métodos , Cianobactérias/crescimento & desenvolvimento , Ácidos Graxos/análise , Técnica de Fratura por Congelamento , Lipídeos de Membrana/análise , Microscopia Eletrônica , TemperaturaRESUMO
The formation of 'lipidic' particles corresponding to inverted lipid micelles in freeze-fracture replicas of aqueous dispersions of mono- and digalactosyldiacylglycerols can be greatly enhanced either by increasing the temperature from which the samples are thermally quenched or by the addition of cryoprotectants such as ethylene glycol. In the case of the heated samples, the lipids tend to form quasi-crystalline structures consisting of sheets of 8-9 nm diameter particles organised on an orthorhombic lattice. The orientation of alternate sheets varies giving rise to a characteristic herring-bone pattern. Ethylene glycol-treated samples, in contrast, form more regular structures consisting of 13-16 nm diameter particles. Lowering the temperature from which the samples are quenched and/or decreasing the concentration of ethylene glycol reduces the frequency of formation of such structures. A number of intermediate states associated with the reincorporation of the lipid molecules of the inverted micelles into the lamella phase are also identified. The factors influencing particle formation are briefly discussed. It is concluded that the destabilisation of lipid-water interactions play a major role in this process.
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Coloides , Diglicerídeos , Galactolipídeos , Glicerídeos , Glicolipídeos , Micelas , Etilenoglicóis , Técnica de Fratura por Congelamento , Temperatura Alta , Microscopia Eletrônica , Conformação MolecularRESUMO
Saccharomyces cerevisiae NCYC 239 suspended in solutions of NaCl showed two distinct plateaus in plots of electrophoretic mobility vs. pH, corresponding to pKa values of approx. 2 and 5. This is in contrast to cells suspended in buffer where only a single pKa (4) can be determined. Modification of cells with KI/I2 or nitrous acid led to altered electrophoretic mobility, indicating the presence of sulphydryl and amino groups, respectively, in the yeast cell surface, whereas uranyl nitrate modification had little effect, suggesting phosphate groups to be absent. Electron micrographs showed visible effects of KI/I2 and nitrous acid modification on cell membrane structure, and in these modified cells amphotericin B uptake was rapid. It is suggested that diffusion through the cell wall is the rate-limiting step for amphotericin B uptake. An activation energy of 20 kJ X mol-1 was determined for uptake of amphotericin B by unmodified cells.
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Anfotericina B/metabolismo , Iodo/farmacologia , Nitritos/farmacologia , Ácido Nitroso/farmacologia , Iodeto de Potássio/farmacologia , Saccharomyces cerevisiae/fisiologia , Parede Celular/ultraestrutura , Fenômenos Químicos , Química , Eletroforese , Técnica de Fratura por Congelamento , Concentração de Íons de Hidrogênio , Microscopia Eletrônica , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/ultraestrutura , Termodinâmica , Nitrato de Uranil/farmacologiaRESUMO
AIM: To establish the uptake of contralateral risk reducing mastectomy in women informed of their risks and options at time of diagnosis of their primary unilateral breast cancer. METHODS: We have assessed the surgical choices of 70 women diagnosed with breast cancer <50 years as part of a family history surveillance program and fully informed about their contralateral risks and surgical options. We have compared this to women from other surgical clinics who were subsequently found to harbour a pathogenic BRCA1/2 mutation. RESULTS: Sixty-five percent (13/20) of BRCA1/2 mutation carriers and 59% (n=20/34) of those at the highest level of risk pre-diagnosis (33+% lifetime risk) opted for contra-lateral mastectomy in the study sample. In contrast only 10% (n=9/88) women identified as mutation carriers from other clinics opted for such surgery. CONCLUSIONS: We would suggest that women with a significant family history and therefore a high contra-lateral breast cancer risk, should have these risks and management options discussed at the time of diagnosis of breast cancer.
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Neoplasias da Mama/cirurgia , Predisposição Genética para Doença/psicologia , Mastectomia/psicologia , Adulto , Fatores Etários , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Neoplasias da Mama/psicologia , Comportamento de Escolha , Feminino , Genes BRCA1 , Genes BRCA2 , Testes Genéticos , Humanos , Programas de Rastreamento , Mastectomia/métodos , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
The water permeability of human erythrocytes has been monitored by nuclear magnetic resonance (NMR) before and after treatment of the cells with various sulfhydryl reagents. Preincubation of the cells with N-ethylmaleimide (NEM), a non-inhibitory sulfhydryl reagent, results in a faster and more sensitive inhibition of water exchange by mercurials. The inhibition of water exchange by p-chloromercuribenzene sulfonate (PCMBS) was maximal at a binding of approximately 10 nmol PCMBS per mg protein when non-specific sulfhydryl groups are blocked by NEM. Inhibition by PCMBS has been correlated with the binding of 203Hg to erythrocyte membrane proteins. A significant binding of label to band 3 and the polypeptides in band 4.5 occurs, with approximately 1 mol of mercurial bound per mol of protein. Inhibition of water transport by sulfhydryl reagents does not induce major morphological changes in the cells as assessed by freeze-fracture and scanning electron microscopy.
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Permeabilidade da Membrana Celular , Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , 4-Cloromercuriobenzenossulfonato/sangue , Transporte Biológico , Difusão , Membrana Eritrocítica/ultraestrutura , Técnica de Congelamento e Réplica , Humanos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica , Microscopia Eletrônica de VarreduraRESUMO
We report a case of metastatic malignant melanoma in an inguinal lymph node, expressing ganglioneuroblastic differentiation. This was characterized by the presence of discrete nests and islands of large ganglion cells with abundant cytoplasm and eccentric nuclei with prominent nucleoli admixed with smaller primitive neuroblasts. The cells were separated by pale pink fibrillar material representing neuritic cell processes. These foci of ganglioneuroblastoma were seen over a background of an otherwise typical metastatic epithelioid, focally melanotic, malignant melanoma. Immunohistochemistry showed positivity for neurofilament, synaptophysin, chromogranin, vasoactive intestinal peptide, and glial fibrillary acidic protein in the areas with ganglioneuroblastic differentiation, but not in the melanocytic component. Conversely, HMB45 positivity was expressed by the melanocytic cells only. S-100 protein and Melan-A, a putative melanocytic marker, showed positivity in both melanocytic and ganglioneuroblastic components. Ultrastructurally, neuritic cell processes and dense core neurosecretory granules were identified in the ganglionic and neuroblastic cells. A subsequent nodal metastasis in the same region showed focal neuroblastic differentiation without the ganglionic element. No evidence of neuronal or ganglionic differentiation was seen in the primary skin melanoma.
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Ganglioneuroblastoma/patologia , Melanoma/patologia , Neoplasias Cutâneas/patologia , Adulto , Feminino , Humanos , Imuno-Histoquímica , Metástase Linfática , Melanoma/secundário , Melanoma/cirurgia , Microscopia Eletrônica , Neoplasias Cutâneas/cirurgiaRESUMO
The microstructure of ultra-high molecular weight polyethylene (UHMWPE) has been studied using a range of techniques. Both the unprocessed base powder and ram-extruded polymer have been examined using optical microscopy, scanning and transmission electron microscopy and small-angle light scattering. By examining the microstructure of samples compression moulded at a range of temperatures, techniques have been developed to assess the degree of consolidation of the processed polymer. The raw polymer is a powder with a particle size in the range 50-250 microm. These particles are themselves agglomerates of much finer particles typically 0.5-1 microm in size. It has been suggested that these sub-micron particles may be the origin of the sub-micron wear debris found in tissues around total joint replacements. However, examination of the ram-extruded polymer, from which implants are machined, shows a different structure from the powder, with no evidence of retention of the 0.5-1 microm structure seen in the powder in the processed material. It thus appears that the similarity in size between the sub-micron wear debris particles and the fine structure seen in the unprocessed UHMWPE resin is coincidental. Processed UHMWPE does show a 'memory' of the grain boundaries between powder particles and the degree of consolidation can be assessed by observing the distinctiveness of these boundaries.
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Materiais Biocompatíveis/química , Prótese Articular , Polietilenos/química , Fenômenos Biomecânicos , Varredura Diferencial de Calorimetria , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Peso Molecular , Tamanho da Partícula , Pós , Difração de Raios XRESUMO
AIMS: To establish the structural changes that occur in deep surgical wounds engrafted with allogeneic sheets, their time course and inter-relation. METHODS: Deep surgical wounds following shave excision of tattoos (down to deep dermis/subcutaneous fat) were treated with sheets of sex mismatched allogeneic keratinocytes in 19 patients and then biopsied weekly until wound healing was complete. More superficial surgical wounds--that is, 20 standard skin graft donor sites, were biopsied at seven to 10 days (all healed) following application of keratinocyte allografts. All biopsy specimens were examined with a large panel of monoclonal antibodies to keratins, envelope proteins, basement membrane components, and to extracellular matrix components. RESULTS: The hyperproliferative keratin pair K6/16 was expressed in all wounds, for up to six weeks in keratinocyte grafted deep wounds, and up to six months in split thickness skin grafted wounds. CONCLUSIONS: Keratins 6 and 16 have not been detected in normal skin, although the relevant mRNA has. This raises the possibility of regulation at a post-transcriptional level allowing a rapid response to injury with cytoskeletal changes that may aid cell migration. This keratin pair offers the most sensitive marker for altered epidermis following wounding.