RESUMEN
Recent studies have provided insights into the pathology of and immune response to COVID-191-8. However, a thorough investigation of the interplay between infected cells and the immune system at sites of infection has been lacking. Here we use high-parameter imaging mass cytometry9 that targets the expression of 36 proteins to investigate the cellular composition and spatial architecture of acute lung injury in humans (including injuries derived from SARS-CoV-2 infection) at single-cell resolution. These spatially resolved single-cell data unravel the disordered structure of the infected and injured lung, alongside the distribution of extensive immune infiltration. Neutrophil and macrophage infiltration are hallmarks of bacterial pneumonia and COVID-19, respectively. We provide evidence that SARS-CoV-2 infects predominantly alveolar epithelial cells and induces a localized hyperinflammatory cell state that is associated with lung damage. We leverage the temporal range of fatal outcomes of COVID-19 in relation to the onset of symptoms, which reveals increased macrophage extravasation and increased numbers of mesenchymal cells and fibroblasts concomitant with increased proximity between these cell types as the disease progresses-possibly as a result of attempts to repair the damaged lung tissue. Our data enable us to develop a biologically interpretable landscape of lung pathology from a structural, immunological and clinical standpoint. We use this landscape to characterize the pathophysiology of the human lung from its macroscopic presentation to the single-cell level, which provides an important basis for understanding COVID-19 and lung pathology in general.
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COVID-19/patología , COVID-19/virología , Progresión de la Enfermedad , Pulmón/patología , Pulmón/virología , SARS-CoV-2/patogenicidad , Análisis de la Célula Individual , Células Epiteliales Alveolares/patología , Células Epiteliales Alveolares/virología , COVID-19/mortalidad , COVID-19/fisiopatología , Humanos , Inflamación/patología , Inflamación/fisiopatología , Inflamación/virología , Pulmón/fisiopatología , Macrófagos/inmunología , Neutrófilos/inmunología , Factores de Tiempo , Tropismo ViralRESUMEN
BACKGROUND: The number of publications on the subject of diversity, equity, and inclusion has surged in the last 5 years. However, a systematic review of this topic has not been published. METHOD: Six top plastic surgery journals were queried from 2018 to 2023 using the search term "diversity." Methods, conclusions, and recommendations were tabulated. RESULTS: A total of 138 publications were identified; 68 studies presented data suitable for analysis. All studies were retrospective. Currently, over 40% of plastic surgery residency applicants are women. The proportion of women in integrated plastic surgery residents is now 43%. In 2021 and 2022, the percentage of female first-year residents exceeded men. The percentage of female presenters at meetings (34%) is double the number in the workforce (17%). Twenty-five percent of academic faculty positions and 22% of program director positions are now held by women. Underrepresented minorities account for fewer than 10% of applicants to integrated plastic surgery residencies. DISCUSSION: The proportion of Black and Hispanic applicants to integrated plastic surgery residencies (6% and 8%, respectively) mirrors the proportion of Black and Hispanic medical students (7% and 6%, respectively). Numerous recommendations have been made to increase the proportion of underrepresented minorities in plastic surgery programs. CONCLUSIONS: The representation of women in plastic surgery has increased dramatically. A lack of Hispanics and Blacks reflects a small pool of applicants, as opposed to a "leaky pipeline."
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Diversidad Cultural , Internado y Residencia , Cirugía Plástica , Cirugía Plástica/educación , Cirugía Plástica/estadística & datos numéricos , Humanos , Internado y Residencia/estadística & datos numéricos , Femenino , Estados Unidos , Masculino , Médicos Mujeres/estadística & datos numéricos , Grupos Minoritarios/estadística & datos numéricos , Selección de ProfesiónRESUMEN
Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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Implantación de Mama , Implantes de Mama , Humanos , Implantes de Mama/efectos adversos , Implantación de Mama/efectos adversosRESUMEN
ABSTRACT: Journals insist that authors disclose their financial conflicts. However, the same standard is rarely imposed on journal editors. Surprisingly, most high-impact medical journals (about 88%) do not publish editor conflicts of interest (COIs).The Sunshine Act makes it possible to query physician payments from industry. Importantly, some companies are exempted. The leading 5 US-based plastic surgery journals were investigated. Only chief editors and coeditors were included, for a total of 10 editors. The range of payments was US $0 to US $297,000 between 2015 and 2021. The mean payment was $90,890, or $12,984 per year. This amount may be compared with the average industry payments to all plastic surgeons, which is approximately $5000 annually.Examples of editor COIs are considered. In one case, an article detailing important factual deficiencies in an article defending Allergan macrotextured breast implants was rejected by coeditors that included a coeditor who received payments from Allergan. An article promoting radiofrequency treatments containing previously reported data was accepted by a chief editor with a COI, who was also a coauthor.Articles claiming improved scarring for a wound adhesive device and numerous benefits for an Allergan implant insertion funnel also found acceptance by conflicted chief editors, despite serious deficiencies.Editor COIs should be published. Attempts to manage editor COI have not been successful. No data support a dollar limit or expiry date for COIs. Relevance and breadth of COIs are unsolved problems. The ethics of industry payments to physicians are questionable at best. An alternative option is recommended-elimination of COI for journal editors. This remedy would restore editorial integrity and avoid the need for recusals. There is precedence. About half of high-impact medical journal editors have no COIs. Industry subsidies in general should be reconsidered. Abandoning them would be in the best interest of our patients and our specialty.
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Implantación de Mama , Procedimientos de Cirugía Plástica , Cirujanos , Cirugía Plástica , Humanos , Conflicto de InteresesRESUMEN
BACKGROUND: The Keller funnel (Allergan; AbbVie Inc, North Chicago, IL) is commonly used to insert breast implants as part of a "no touch" protocol. Many plastic surgeons believe that this device reduces the risk of capsular contracture. This review was undertaken to evaluate the evidence regarding any reduction in capsular contracture rate, other possible benefits, safety and to investigate financial conflict of interest. METHODS: A PubMed electronic literature search was conducted to identify studies comparing capsular contracture rates with and without the Keller funnel. The Open Payments database was accessed for information regarding corporate payments to plastic surgeons. RESULTS: Two retrospective historical case-control studies, published in 2016 and 2018, were identified. Both studies had important confounders, including implant type and placement, which are known to affect capsular contracture rates. Major financial conflicts of interest were present. Most authors did not disclose these conflicts, which totaled more than $1 million and were usually categorized as gifts from Allergan, which purchased the Keller funnel in 2017. DISCUSSION: Financial conflict of interest, along with publication bias, creates a bias toward publication of positive findings. No reliable evidence supports a "no touch" technique, which is a misnomer because manual handling of implants is unavoidable, even when using a funnel. Recent microbiological studies do not support a specific bacterial etiology for capsular contracture. No evidence supports contamination by the surgeon touching the implant. Among other proposed benefits, such as reduced operating time, less contamination, a shorter incision, and less implant trauma, only a slightly shorter incision (1 cm) is supported by the evidence. The cost is $150 per funnel. CONCLUSIONS: No reliable evidence supports the use of a Keller funnel to reduce the risk of capsular contracture. Both supportive studies contain confounding variables, limited follow-up time, and no plausible scientific basis for efficacy. Institutional review board approval of studies on human subjects is not optional. Financial conflicts of interest are extraordinary in their magnitude and potential for creating undue influence. Greater transparency and honest disclosures are needed.
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Implantación de Mama , Implantes de Mama , Contractura , Humanos , Implantes de Mama/efectos adversos , Implantación de Mama/métodos , Estudios Retrospectivos , Contractura Capsular en Implantes/etiologíaRESUMEN
BACKGROUND: Energy-based treatments include ultrasound, lasers, cryolipolysis, and radiofrequency. The most recent energy treatment for noninvasive body contouring is electromagnetic treatments-a hot topic in plastic surgery today. A systematic review to assess efficacy and safety has not been published. METHODS: An electronic search was performed using PubMed to identify the literature describing electromagnetic treatments. Measurements from imaging studies were tabulated and compared. RESULTS: Fourteen clinical studies were evaluated. Two studies included simultaneous radiofrequency treatments. In 11 studies, the Emsculpt device was used; in 2 studies, the Emsculpt-Neo device was used. One study included a sham group of patients. The usual protocol was 4 treatments given over a 2-week period. No complications were reported. Eight studies included abdominal measurement data obtained using magnetic resonance imaging, computed tomography, or ultrasound. Photographic results were typically modest. Photographs showing more dramatic results also showed unexplained reductions in untreated areas.Measurement variances were high. The mean reduction in fat thickness was 5.5 mm. The mean increment in muscle thickness was 2.2 mm. The mean decrease in muscle separation was 2.9 mm (P = 0.19). Early posttreatment ultrasound images in 1 study showed an echolucent muscle layer, compared with a more echodense layer at the baseline, consistent with tissue swelling after exercise. Almost all studies were authored by medical advisors for the device manufacturer. DISCUSSION: Measurement data show small reductions in fat thickness, occurring almost immediately after the treatments. Adipocyte removal without tissue swelling would be unique among energy-based treatments. Similarly, muscle hypertrophy is not known to occur acutely after exercise; muscle swelling likely accounts for an early increment in muscle thickness. Any improvement in the diastasis recti is likely fictitious. CONCLUSIONS: Electromagnetic treatments, either administered alone or in combination with radiofrequency, are safe. However, the evidence for efficacy is tenuous. Measured treatment effects are very small (<5 mm). Conflict of interest and publication bias are major factors in studies evaluating energy-based alternatives. The evidence-based physician may not be satisfied that an equivocal treatment benefit justifies the time and expense for patients.
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Contorneado Corporal , Lipectomía , Humanos , Contorneado Corporal/métodos , Estudios de Seguimiento , Satisfacción del Paciente , Lipectomía/métodos , Fenómenos ElectromagnéticosRESUMEN
ABSTRACT: Little information is available regarding how to review a plastic surgery manuscript. This vital responsibility ensures that publications meet an acceptable scientific standard. Thoughtful and thorough reviews are essential to protect patients and surgeons from unscientific practices and products. This discussion provides information for the reviewer, gained from the author's experience, including examples of a thorough review, likely to be useful to the editor, and a cursory one that is unhelpful.The first consideration is relevance. Prerequisites for publication include institutional review board approval, disclosure of financial conflicts, and discussion of the regulatory status of devices. Particular attention is needed to check for conflicts of interest, which are endemic in plastic surgery today. In view of the common practice of using computer-generated imaging, reviewers need to be especially vigilant for inauthentic "photoshopped" photographs. Examples of published images that have been digitally altered are provided.If data are available, it may be possible to check the statistical tests. Reviewers need to be aware of the practice of p-hacking. A quick literature search can identify relevant but unreferenced publications. The manuscript needs to be properly organized into sections. Minor points may be made regarding style. The study design and methodology need to be evaluated to be sure that the conclusions are well supported by data. Randomized studies are rarely feasible. Fortunately, well-done prospective observational studies in consecutive patients can be just as useful. Realistic complication rates are expected. Meta-analyses in plastic surgery are often subject to confounding variables. Comments should be available to the authors; confidential comments hidden from authors are discouraged. Like honesty, transparency is the best policy. Manuscripts should be evaluated solely for merit, not the identity of the author or institution. Timeliness of submission of the review is appreciated by authors.Evidence-based medicine is concerned solely with the facts. The 2 basic criteria are a solid scientific basis and reliable evidence of efficacy. Reviewers need to keep an open mind. Studies that challenge the status quo are often the most valuable ones and are needed for the advancement of the specialty.
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Procedimientos de Cirugía Plástica , Cirugía Plástica , Humanos , Revisión por Pares , Revelación , Proyectos de InvestigaciónRESUMEN
BACKGROUND: Breast implants can be introduced through a variety of incisions, most commonly an inframammary incision, but also a periareolar incision or an axillary incision. Usually, the implant is inserted through the same incision used in performing an augmentation/mastopexy. Some authors use a separate inframammary incision. Capsular contracture is the most common complication of breast augmentation. One theory holds that it is caused by an infected biofilm, prompting surgeons to minimize implant handling, known as the "no touch" technique. This review was undertaken to investigate the relationship, if any, between the access incision and the risk of capsular contracture. METHODS: An electronic literature search was conducted to identify publications comparing capsular contracture rates by the access incision. RESULTS: Ten studies were evaluated. Most were retrospective series. Three were prospective core studies. Some studies reported an increased risk of capsular contracture for a periareolar incision; a similar number did not. One study supported a separate inframammary incision at the time of vertical augmentation/mastopexy. DISCUSSION: Bacterial studies in the last decade show that the resident bacteria on the skin surface and within breast tissue are similar. Sophisticated microbiological evaluation of breast capsules reveals that the microbiome relates to the patient, as opposed to a specific bacterial profile for capsular contracture. A review of the statistics used in determining an advantage for a separate incision at the time of vertical augmentation/mastopexy reveals that there is no statistically significant risk reduction when using an additional inframammary incision, which adds an unnecessary scar. CONCLUSIONS: The access incision at the time of breast augmentation or augmentation/mastopexy is unlikely to affect the capsular contracture risk. There is no need to make a separate incision to insert the implant at the time of augmentation/mastopexy, or to isolate the implant from contact with breast parenchyma. Little evidence supports the "no touch" technique. The etiology of capsular contracture remains unknown.
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Implantación de Mama , Implantes de Mama , Contractura , Mamoplastia , Herida Quirúrgica , Humanos , Estudios Retrospectivos , Estudios Prospectivos , Mamoplastia/métodos , Implantación de Mama/métodos , Implantes de Mama/efectos adversos , Herida Quirúrgica/cirugía , Contractura/cirugía , Contractura Capsular en Implantes/etiologíaRESUMEN
BACKGROUND: Most published studies on abdominoplasty focus on methods to reduce the risk of seromas. These methods include limited dissection (lipoabdominoplasty), quilting sutures, and preservation of the Scarpa fascia. Quantitative evaluation of the aesthetic result has been lacking. METHODS: A retrospective study was undertaken of all patients undergoing abdominoplasty in the author's practice from 2016 to 2022. A full abdominoplasty was performed, usually with liposuction (87%). All patients were treated under total intravenous anesthesia without paralysis or prone positioning. A single closed suction drain was removed 3 or 4 days after surgery. All procedures were performed as outpatients. Ultrasound surveillance was used to detect any deep venous thromboses. No patient received chemoprophylaxis. The operating table was flexed, often to 90°. Deep fascial anchoring sutures were used to attach the Scarpa fascia of the flap to the deep muscle fascia. Measurements of the scar level were made at intervals after surgery up to 1 year. RESULTS: Three hundred ten patients were evaluated, including 300 women. The mean follow-up time was 1 year. The overall complication rate, which included minor scar deformities, was 35.8%. Five deep venous thromboses were detected. There were no hematomas. Fifteen patients (4.8%) developed seromas that were successfully treated by aspiration. The mean vertical scar level 1 month after surgery was 9.9 cm (range, 6.1-12.9 cm). There was no significant change in scar level at subsequent follow-up times up to 1 year. By comparison, the scar level in published studies ranged from 8.6 to 14.1 cm. DISCUSSION: Avoidance of electrodissection reduces tissue trauma that causes seromas. Flexed patient positioning during surgery and deep fascial anchoring sutures are effective in keeping the scar low. By avoiding chemoprophylaxis, hematomas can be avoided. Limiting the dissection (lipoabdominoplasty), preserving the Scarpa fascia, and adding quilting (progressive tension) sutures are unnecessary. CONCLUSIONS: Total intravenous anesthesia offers important safety advantages. Avoiding electrodissection is effective in keeping seroma rates at a tolerable level (5%), and the scar low and more easily concealed. Alternative methods present disadvantages that may contribute to a suboptimal aesthetic result and require additional operating time.
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Abdominoplastia , Trombosis de la Vena , Humanos , Femenino , Cicatriz/prevención & control , Cicatriz/complicaciones , Estudios Retrospectivos , Seroma/etiología , Seroma/prevención & control , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/etiología , Abdominoplastia/métodos , Trombosis de la Vena/complicacionesRESUMEN
The transcription factor Oct1/Pou2f1 promotes poised gene expression states, mitotic stability, glycolytic metabolism and other characteristics of stem cell potency. To determine the effect of Oct1 loss on stem cell maintenance and malignancy, we deleted Oct1 in two different mouse gut stem cell compartments. Oct1 deletion preserved homeostasis in vivo and the ability to establish organoids in vitro, but blocked the ability to recover from treatment with dextran sodium sulfate, and the ability to maintain organoids after passage. In a chemical model of colon cancer, loss of Oct1 in the colon severely restricted tumorigenicity. In contrast, loss of one or both Oct1 alleles progressively increased tumor burden in a colon cancer model driven by loss-of-heterozygosity of the tumor suppressor gene Apc. The different outcomes are consistent with prior findings that Oct1 promotes mitotic stability, and consistent with differentially expressed genes between the two models. Oct1 ChIPseq using HCT116 colon carcinoma cells identifies target genes associated with mitotic stability, metabolism, stress response and malignancy. This set of gene targets overlaps significantly with genes differentially expressed in the two tumor models. These results reveal that Oct1 is selectively required for recovery after colon damage, and that Oct1 has potent effects in colon malignancy, with outcome (pro-oncogenic or tumor suppressive) dictated by tumor etiology.
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Carcinogénesis/genética , Colon/metabolismo , Neoplasias del Colon/genética , Regulación Neoplásica de la Expresión Génica , Factor 1 de Transcripción de Unión a Octámeros/genética , Animales , Azoximetano/administración & dosificación , Carcinogénesis/metabolismo , Carcinogénesis/patología , Colon/efectos de los fármacos , Colon/patología , Neoplasias del Colon/inducido químicamente , Neoplasias del Colon/mortalidad , Neoplasias del Colon/patología , Sulfato de Dextran/administración & dosificación , Modelos Animales de Enfermedad , Femenino , Perfilación de la Expresión Génica , Células HCT116 , Humanos , Integrasas/genética , Integrasas/metabolismo , Intestino Delgado/efectos de los fármacos , Intestino Delgado/metabolismo , Intestino Delgado/patología , Ratones , Ratones Noqueados , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Factor 1 de Transcripción de Unión a Octámeros/deficiencia , Organoides/efectos de los fármacos , Organoides/metabolismo , Organoides/patología , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Regeneración , Transducción de Señal , Análisis de Supervivencia , Tamoxifeno/administración & dosificaciónRESUMEN
BACKGROUND: Subsurface radiofrequency (RF) treatments produce skin contraction by causing coagulation of the underlying subcutaneous fat. This method is marketed to fill a treatment gap for patients who do not wish to have surgery. A systematic review of this subject has not been previously published. METHODS: An electronic search was performed using PubMed to identify the literature describing subsurface RF treatments. RESULTS: Thirty articles were evaluated. An InMode device was used in 23 studies, and a Thermi device was used in 6 studies, with or without liposuction. Treatment areas included the face, neck, body, breasts, and labia. Most studies relied on patient satisfaction scores and physician review of photographs. The most frequent complications were induration and nodules. Most patients experienced prolonged swelling and numbness. Several studies reported marginal mandibular neuropraxias. The skin response after treatment of the abdomen was poor, and seromas were common. The incidence of burns improved after modification of the InMode device. Breast treatment did not appear to be effective in treating ptosis. Patient satisfaction scores were modest. Most studies (77%) were published by authors with a known conflict of interest. In some studies, the photographs did not accurately depict the treatment result. Institutional review board approval and disclosure of off-label regulatory status were often missing. DISCUSSION: Thermal treatment of the subcutaneous tissue introduces extra risks without a compensatory benefit. Comparisons in terms of safety, cost, recovery time, results, and complications do not favor energy-based devices. A treatment gap may be fictitious; properly informed patients may be treated with existing surgical procedures at all ages. CONCLUSIONS: Little evidence supports the efficacy and safety of subcutaneous RF treatments as an improvement over results that may be obtained using traditional surgical methods such as submental lipectomy, liposuction, and abdominoplasty. Photographic integrity is often lacking. Financial conflict of interest is pervasive. Marketing precedes the science. Plastic surgeons need to be aware of these serious limitations and the off-label regulatory status of these devices, before purchasing expensive equipment and recommending subsurface RF treatments to patients.
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Ablación por Radiofrecuencia , Grasa Subcutánea , Cirugía Plástica , Abdominoplastia , Humanos , Lipectomía , Ablación por Radiofrecuencia/efectos adversos , Ablación por Radiofrecuencia/métodos , Grasa Subcutánea/cirugía , Cirugía Plástica/métodos , Resultado del TratamientoRESUMEN
BACKGROUND: Laboratory and clinical research on breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is rapidly evolving. Changes in standard of care and insights into best practice were recently presented at the 3rd World Consensus Conference on BIA-ALCL. OBJECTIVES: The authors sought to provide practice recommendations from a consensus of experts, supplemented with a literature review regarding epidemiology, etiology, pathogenesis, diagnosis, treatment, socio-psychological aspects, and international authority guidance. METHODS: A literature search of all manuscripts between 1997 and August 2021 for the above areas of BIA-ALCL was conducted with the PubMed database. Manuscripts in different languages, on non-human subjects, and/or discussing conditions separate from BIA-ALCL were excluded. The study was conducted employing the Delphi process, gathering 18 experts panelists and utilizing email-based questionnaires to record the level of agreement with each statement by applying a 5-point Likert Scale. Median response, interquartile range, and comments were employed to accept, reject, or revise each statement. RESULTS: The literature search initially yielded 764 manuscripts, of which 405 were discarded. From the remaining 359, only 218 were included in the review and utilized to prepare 36 statements subdivided into 5 sections. After 1 round, panelists agreed on all criteria. CONCLUSIONS: BIA-ALCL is uncommon and still largely underreported. Mandatory implant registries and actions by regulatory authorities are needed to better understand disease epidemiology and address initial lymphomagenesis and progression. Deviation from current diagnosis and treatment protocols can lead to disease recurrence, and research on breast implant risk factors provide insight to etiology.
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Implantación de Mama , Implantes de Mama , Neoplasias de la Mama , Linfoma Anaplásico de Células Grandes , Implantación de Mama/efectos adversos , Implantación de Mama/métodos , Implantes de Mama/efectos adversos , Neoplasias de la Mama/etiología , Femenino , Humanos , Linfoma Anaplásico de Células Grandes/diagnóstico , Linfoma Anaplásico de Células Grandes/epidemiología , Linfoma Anaplásico de Células Grandes/etiología , Recurrencia Local de Neoplasia , Factores de RiesgoRESUMEN
AIM: Alzheimer's disease (AD) is characterised by extracellular deposition of amyloid-ß (Aß) in amyloid plaques and intracellular aggregation and accumulation of hyperphosphorylated tau in neurofibrillary tangles (NFTs). Although several kinases have been identified to contribute to the pathological phosphorylation of tau, kinase-targeted therapies for AD have not been successful in clinical trials. Critically, the kinases responsible for numerous identified tau phosphorylation sites remain unknown. G protein-coupled receptor (GPCR) kinases (GRKs) have recently been implicated in phosphorylation of non-GPCR substrates, for example, tubulin and α-synuclein, and in neurological disorders, including schizophrenia and Parkinson's disease. Accordingly, we investigated the involvement of GRKs in the pathophysiology of AD. METHODS: We performed a comprehensive immunohistochemical and biochemical analysis of the ubiquitously expressed GRKs, namely, GRK2, 3, 5 and 6, in postmortem human brain tissue of control subjects and AD patients. RESULTS: GRKs display unique cell-type-specific expression patterns in neurons, astrocytes and microglia. Levels of GRKs 2, 5 and 6 are specifically decreased in the CA1 region of the AD hippocampus. Biochemical evidence indicates that the GRKs differentially associate with total, soluble and insoluble pools of tau in the AD brain. Complementary immunohistochemical studies indicate that the GRKs differentially colocalise with total tau, phosphorylated tau and NFTs. Notably, GRKs 3 and 5 also colocalise with amyloid plaques. CONCLUSION: These studies establish a link between GRKs and the pathological phosphorylation and accumulation of tau and amyloid pathology in AD brains and suggest a novel role for these kinases in regulation of the pathological hallmarks of AD.
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Enfermedad de Alzheimer/patología , Encéfalo/patología , Quinasas de Receptores Acoplados a Proteína-G/metabolismo , Ovillos Neurofibrilares/patología , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Astrocitos/metabolismo , Humanos , Neuronas/patología , Proteínas tau/metabolismoRESUMEN
Introduction: Mechanically induced skin breakdown is a significant problem for many lower-limb prosthesis users. It is known that skin can adapt to the mechanical stresses of prosthesis use thereby reducing the risk of breakdown, yet little is understood about the biology behind skin adaptation. This is a proof-of-concept study for the use of novel, noninvasive optical coherence tomography (OCT) imaging techniques to investigate skin adaptation. Methods: Two OCT imaging-based tests were used to evaluate features of the skin that may be involved in adaptation to limb-socket interface stresses. The tests were used to assess the function and structure of the cutaneous microvasculature, respectively. Epidermal thickness was also quantified. Tests were run on three lower-limb prosthesis users in a region of the residual limb believed to be highly stressed within the prosthetic socket. The measurements were compared with measurements taken at a location-matched site on the contralateral limb. Results: Two of three participants demonstrated a faster time-to-peak and larger peakmagnitude reactive hyperemia response in their residual limb compared with their contralateral limb. Two of three participants also demonstrated a larger magnitude vessel density at maximum dilation in their residual limb versus contralateral limb. The epidermal thickness was greater in the residual limb versus contralateral limb for all participants. Conclusions: This study demonstrated the utility of two novel OCT imaging techniques for investigating skin adaptation in users of lower-limb prostheses. If we are able to confirm these findings on a larger subject population, we will better understand the biology behind mechanically induced skin adaptation. These findings, along with the noninvasive OCT imaging methods introduced here, would have the potential to improve clinical practice by enabling the development of rehabilitation techniques and therapeutics to better strengthen skin, thereby reducing the incidence of harmful skin breakdown.
RESUMEN
BACKGROUND: Skin breakdown due to limb-socket interface stress is a significant problem for lower limb prosthesis users. While it is known that skin can adapt to stress to become more resistant to breakdown, little is understood about skin adaptation and few methods exist to noninvasively investigate it. In this study, we present novel, noninvasive imaging methods using Optical Coherence Tomography (OCT) to assess key features of the cutaneous microvasculature that may be involved in skin adaptation. MATERIALS AND METHODS: Eight able-bodied participants wore a modified below-knee prosthetic socket for two weeks to stress the skin of their lower limb. Two OCT-based imaging tests were used to assess the function and structure, respectively, of the cutaneous microvasculature at multiple time points throughout the socket wear protocol. RESULTS: A measurable reactive hyperemia response was reliably induced in the skin of study participants in the vascular function assessment test. The vascular structure assessment demonstrated excellent field-of-view repeatability, providing rich data sets of vessel structure. No statistically significant differences were found in any of the measurements when compared between time points of the adaptation protocol. The participants' limbs were likely not stressed enough by the able-bodied socket to induce measurable skin adaptation. CONCLUSION: This study introduced new techniques to investigate skin adaptation to mechanical stress. If the key limitations are addressed, these methods have the potential to provide insight into the function and structure of the cutaneous microvasculature that previously could not be attained noninvasively.
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Fenómenos Fisiológicos de la Piel , Piel , Estrés Mecánico , Tomografía de Coherencia Óptica , Adulto , Miembros Artificiales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Piel/diagnóstico por imagenRESUMEN
BACKGROUND: Capsulectomy has traditionally been recommended as a treatment for capsular contracture after breast augmentation. With the advent of breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL), and the Food and Drug Administration's decision to ban Biocell textured devices, this operation has taken on new importance. This review was undertaken to better inform clinical recommendations for women with textured devices. METHODS: An electronic search was performed using PubMed to identify all the available literature on the subject of capsulectomy and open capsulotomy (the alternative treatment). RESULTS: Fifty-seven articles on this topic were identified. Capsulectomy was widely recommended for treatment of capsular contracture, although many authors recommended leaving thin capsular tissue behind in the absence of symptoms. En bloc resection was recommended only for women with a diagnosis of BIA-ALCL. No information supported a prophylactic role for capsulectomy in asymptomatic women with textured breast implants who are concerned regarding their future risk of BIA-ALCL. Routine pathologic examination in asymptomatic patients was not supported. DISCUSSION: Capsulectomy adds substantially to the surgical risk, discomfort, recovery time, and expense. Implant removal or replacement without a simultaneous capsulectomy is atraumatic and poses negligible risk. CONCLUSIONS: Capsulectomy introduces additional morbidity and is not mandatory for asymptomatic patients. Implant removal or exchange for smooth implants without a capsulectomy may be an acceptable choice for many women who do not demonstrate capsular pathology. However, any symptoms or surgical findings suggesting pathology warrant a capsulectomy. En bloc resections are reserved for patients diagnosed with BIA-ALCL.
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Implantación de Mama , Implantes de Mama , Neoplasias de la Mama , Linfoma Anaplásico de Células Grandes , Mamoplastia , Mama , Neoplasias de la Mama/cirugía , Femenino , Humanos , Linfoma Anaplásico de Células Grandes/etiología , Linfoma Anaplásico de Células Grandes/cirugíaRESUMEN
Understanding the pressure distributions at the limb-socket interface is essential to the design and evaluation of prosthetic components for lower limb prosthesis users. Force sensing resistors (FSRs) are employed in prosthetics research to measure pressure at this interface due to their low cost, thin profile, and ease of use. While FSRs are known to be sensitive to many sources of error, few studies have systematically quantified these errors using test conditions relevant to lower limb prosthetics. The purpose of this study was to evaluate FSR accuracy for the measurement of lower limb prosthetics interface pressures. Two FSR models (Flexiforce A201 and Interlink 402) were subjected to a series of prosthetic-relevant tests. These tests included: (1) static compression, (2) cyclic compression, and (3) a combined static and cyclic compression protocol mimicking a variable activity (walk-sit-stand) procedure. Flexiforce sensors outperformed Interlink sensors and were then subjected to two additional tests: (4) static curvature and (5) static shear stress. Results demonstrated that FSRs experienced significant errors in all five tests. We concluded that: (1) if used carefully, FSRs can provide an estimate of prosthetic interface pressure, but these measurements should be interpreted within the expected range of possible measurement error given the setup; (2) FSRs should be calibrated in a setup that closely matches how they will be used for taking measurements; and (3) both Flexiforce and Interlink sensors can be used to estimate interface pressures; however, in most cases Flexiforce sensors are likely to provide more accurate measurements.