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BACKGROUND: Acne vulgaris (AV) is a widespread inflammatory skin condition associated with increased sebum production, abnormal keratinization, bacterial overgrowth, and inflammation. Overactive sebaceous glands (SGs) produce excess sebum, promote Cutibacterium acnes growth, and affect acne development. Energy-based treatments (EBDs), including light therapy, photodynamic therapy (PDT), lasers, and radiofrequency (RF) devices, have emerged as effective treatment options. As the use of EBDs becomes more widespread, it is imperative to understand their effects on skin parameters, such as sebum, in AV. METHODS: Searches were conducted in Embase, PubMed, Web of Science, and the Cochrane Library. The studies included were randomized and nonrandomized trials on facial AV that used EBDs and featured objective casual sebum level (CSL) measurements via Sebumeter. Data synthesis involved percentage reductions in CSL at follow-ups compared to baseline. RESULTS: Twenty-three studies were analyzed. PDT and RF consistently reduced CSL by 30%-40% and 30%-35%, respectively. Laser therapy showed lesser reductions, whereas light therapy varied significantly and studies had a high risk of bias. All EBD therapies were more effective than no treatment and PDT was superior to light monotherapy. Laser therapy combined with fractional microneedling radiofrequency (FMR) or as a standalone was more effective than laser alone. CONCLUSION: Noninvasive sebum measurement provides valuable insights into AV treatment efficacy. PDT, lasers, especially the 1450-nm diode laser, and FMR are promising for reducing sebum. Standardization of measurement techniques and further research are vital for enhancing treatment personalization, reducing side effects, and improving AV management.
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The gap between organ supply and demand in liver transplantation remains large in most parts of the world. One strategy to increase the donor pool is to use grafts infected with HCV, HBV, and/or HIV viruses. We aimed to explore the current use of HBsAg-positive liver grafts worldwide. A prospective cross-sectional web-based survey was designed, with a total of 28 queries, assessing national and local regulations, center experience, and center-specific experience related to the topic, and sent to all members of International Liver Transplantation Society, European Association for the Study of the Liver, and American Association for the Study of the Liver, and promoted on social media. A total of 135 liver transplant centers answered the survey: 38% from WHO European Regions, 39% from American regions, and 9.7% from South-East Asian regions. Most of the participating centers (67.3%) had been performing liver transplantation for over 15 years, with a mean of 66.5 liver transplants per year, and 54% also performed living-donor liver transplants. HBV-related disease was the indication for liver transplantation in an average of 15% of all liver transplantation cases. Regarding national and/or regional regulations, 40% of the centers reported that the use of HBsAg-positive donors was permitted, and an additional 20% could use them under special circumstances. Thirty-two centers (31%) had previously used HBsAg-positive donors. Among these centers, 62.5% conducted living-donor liver transplants and showed an increased inclination toward the use of HBsAg-positive grafts in centers with elevated waitlist mortality. HBsAg-positive donors are underutilized worldwide. The use of HBsAg-positive liver grafts could help to increase the donor pool, particularly in highly endemic areas.
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BACKGROUND: One of the primary goals of the Liver Cirrhosis Network (LCN) is to develop a cohort study to better understand and predict the risk of hepatic decompensation and other clinical and patient-reported outcomes among patients with Child A cirrhosis. METHODS: The LCN consists of a Scientific Data Coordinating Center (SDCC) and 10 clinical centers whose investigators populate multiple committees. The LCN Definitions and Measurements Committee developed preliminary definitions of cirrhosis and its complications by literature review, expert opinion, and reviewing definition documents developed by other organizations. The Cohort Committee developed the study protocol with the input of the steering committee. RESULTS: The LCN developed a prospective cohort study to describe and predict the rates of incident clinical events pertaining to first decompensation and patient reported outcomes. The LCN developed a pragmatic definition of compensated cirrhosis incorporating clinical, laboratory, imaging, and histological criteria. Definitions of incident and recompensated ascites, overt hepatic encephalopathy, variceal hemorrhage, bleeding due to portal gastropathy, and hepatocellular carcinoma were also codified. CONCLUSION: The LCN Cohort Study design will inform the natural history of cirrhosis in contemporary patients with compensated cirrhosis. The LCN Definitions and Measures Committee developed criteria for the definition of cirrhosis to standardize entry into this multi-center cohort study and standardized criteria for liver-related outcome measures. This effort has produced definitions intended to be both sensitive and specific as well as easily operationalized by study staff such that outcomes critical to the LCN cohort are identified and reported in an accurate and generalizable fashion.
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The American Diabetes Association and the European Association for the Study of Diabetes published a 2022 consensus report recommending changes in diabetes care. This Perspective raises three concerns: with how the report summarizes evidence, how it frames the social determinants of health (SDOH), and with its transnational composition and conflicts of interest. The Perspective analyzes three new clinical recommendations that change the role of metformin from first-line therapy to a first-line option, for the inclusion of weight management as a co-primary treatment goal with glycemic control for patients without cardiac or renal complications, and for addition of the SDOH as a universal component of diabetes care together with lifestyle changes and self-management support. The Perspective considers how the poor evidence assessments of the recommendations and the imprecise framing of the SDOH introduce bias. The composition of the panel's membership poorly represents and accounts for the challenges faced by vulnerable US communities or safety net providers. The report is placed in a historical context for diabetes of organized medicine's failures to overcome prejudices and promote health equity. The Perspective concludes that the report perpetuates a pattern of prejudice within organized medicine at the expense of scientific precision and health equity.
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INTRODUCTION: There is considerable debate over the indication of liver transplantation (LT) for critically ill patients with cirrhosis, in part due to their potentially poor post-LT prognosis. We analyzed the epidemiology and outcome of LT for critically ill patients with cirrhosis over 4 time periods of 4 years. METHODS: We included adult patients who underwent liver transplant alone between 2005 and 2020 using the United Network for Organ Sharing registry database. We defined critically ill patients with cirrhosis as being in the intensive care unit with 1 or more of the following characteristics at the time of LT: (i) grade III/IV hepatic encephalopathy, (ii) mechanical ventilation, (iii) dialysis, and (iv) vasopressors. RESULTS: A total of 85,594 LT recipients were included, 5,827 (6.8%) of whom were classified as being critically ill with cirrhosis at the time of LT. The number and percentage of critically ill LT recipients with cirrhosis increased over the study period: 819 (4.3%) in 2005-2008 vs 2,067 (7.9%) in 2017-2020, P < 0.001. There was a 17% absolute increase in 1-year survival after LT: 72.5% in 2005-2008 vs 89.5% in 2017-2020, P < 0.001. The 1-year post-LT survival gap between critically ill and noncritically ill patients with cirrhosis narrowed over the study period: 16.7 percentage points in 2005-2008 vs 4.6 percentage points in 2017-2020. The year of LT was independently associated with lower 1-year post-LT mortality (hazard ratio 0.92, 95% confidence interval 0.91-0.93, P < 0.001). DISCUSSION: The absolute number and relative percentage of LT recipients who were critically ill increased over time, as did 1-year post-LT survival. Meanwhile, the gap in survival between this group of patients and noncritically ill patients with cirrhosis decreased but persisted. Cautious access to selected LT candidates who are critically ill may be warranted, provided the gap in survival with noncritically ill patients remains as small as possible.
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BACKGROUND: Specialized aesthetic skincare treatments are an important part of helping reduce facial signs of aging. AIMS: This article highlights real-world experience with a Macrocystis pyrifera ferment-containing skincare regimen comprising a cleansing foam, a serum, and a moisturizer with anti-aging, anti-inflammatory, anti-erythema, and healing properties for facial skin condition improvement. PATIENTS/METHODS: The real-world case (RWC) series presented highlights and the expert panel's clinical experience with the M. pyrifera ferment-containing skincare regimen used for 12 weeks to improve facial skin conditions. The panelists convened a meeting to discuss and select RWCs from their practice using the M. pyrifera ferment-containing skincare regimen. RESULTS: The RWC series showed that erythema and inflamed, easily irritated skin bother patients, even when it is mild. Reducing inflammation, erythema, and visible signs of facial aging and improving skin health contributed to patient satisfaction. CONCLUSION: The M. pyrifera ferment-containing skincare regimen comprising a cleansing foam, a serum, and a moisturizer is effective in decreasing the visible effects of inflammation and signs of aging while promoting healing by enhancing barrier resilience and recovery.
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Cara , Rejuvenecimiento , Envejecimiento de la Piel , Cuidados de la Piel , Humanos , Envejecimiento de la Piel/efectos de los fármacos , Femenino , Persona de Mediana Edad , Cuidados de la Piel/métodos , Satisfacción del Paciente , Adulto , Eritema/tratamiento farmacológico , Anciano , Masculino , Resultado del TratamientoRESUMEN
BACKGROUND AND AIMS: While avoidance of long-term corticosteroids is a common objective in the management of autoimmune hepatitis (AIH), prolonged immunosuppression is usually required to prevent disease progression. This study investigates the patient and provider factors associated with treatment patterns in US patients with AIH. APPROACH AND RESULTS: A retrospective cohort of adults with the incident and prevalent AIH was identified from Optum's deidentified Clinformatics Data Mart Database. All patients were followed for at least 2 years, with exposures assessed during the first year and treatment patterns during the second. Patient and provider factors associated with corticosteroid-sparing monotherapy and cumulative prednisone use were identified using multivariable logistic and linear regression, respectively.The cohort was 81.2% female, 66.3% White, 11.3% Black, 11.2% Hispanic, and with a median age of 61 years. Among 2203 patients with ≥1 AIH prescription fill, 83.1% received a single regimen for >6 months of the observation year, which included 52.2% azathioprine monotherapy, 16.9% azathioprine/prednisone, and 13.3% prednisone monotherapy. Budesonide use was uncommon (2.1% combination and 1.9% monotherapy). Hispanic ethnicity (aOR: 0.56; p = 0.006), cirrhosis (aOR: 0.73; p = 0.019), osteoporosis (aOR: 0.54; p =0.001), and top quintile of provider AIH experience (aOR: 0.66; p = 0.005) were independently associated with lower use of corticosteroid-sparing monotherapy. Cumulative prednisone use was greater with diabetes (+441 mg/y; p = 0.004), osteoporosis (+749 mg/y; p < 0.001), and highly experienced providers (+556 mg/y; p < 0.001). CONCLUSIONS: Long-term prednisone therapy remains common and unexpectedly higher among patients with comorbidities potentially aggravated by corticosteroids. The greater use of corticosteroid-based therapy with highly experienced providers may reflect more treatment-refractory disease.
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BACKGROUND: Opportunistic infections (OIs) are a significant cause of morbidity and mortality after organ transplantation, though data in the liver transplant (LT) population are limited. METHODS: We performed a retrospective cohort study of LT recipients between January 1, 2007 and Deceber 31, 2016 using Medicare claims data linked to the Organ Procurement and Transplantation Network database. Multivariable Cox regression models evaluated factors independently associated with hospitalizations for early (≤1 year post transplant) and late (>1 year) OIs, with a particular focus on immunosuppression. RESULTS: There were 11 320 LT recipients included in the study, of which 13.2% had at least one OI hospitalization during follow-up. Of the 2638 OI hospitalizations, 61.9% were early post-LT. Cytomegalovirus was the most common OI (45.4% overall), although relative frequency decreased after the first year (25.3%). Neither induction or maintenance immunosuppression were associated with early OI hospitalization (all p > .05). The highest risk of early OI was seen with primary sclerosing cholangitis (aHR 1.74; p = .003 overall). Steroid-based and mechanistic target of rapamycin inhibitor-based immunosuppression at 1 year post LT were independently associated with increased late OI (p < .001 overall). CONCLUSION: This study found OI hospitalizations to be relatively common among LT recipients and frequently occur later than previously reported. Immunosuppression regimen may be an important modifiable risk factor for late OIs.
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Hospitalización , Trasplante de Hígado , Medicare , Infecciones Oportunistas , Humanos , Estados Unidos/epidemiología , Masculino , Medicare/estadística & datos numéricos , Femenino , Hospitalización/estadística & datos numéricos , Estudios Retrospectivos , Factores de Riesgo , Anciano , Infecciones Oportunistas/epidemiología , Persona de Mediana Edad , Trasplante de Hígado/efectos adversos , Inmunosupresores/efectos adversos , Inmunosupresores/uso terapéutico , Terapia de Inmunosupresión/efectos adversos , Infecciones por Citomegalovirus/epidemiologíaRESUMEN
The Infinium DNA Methylation BeadChips have significantly contributed to population-scale epigenetics research by enabling epigenome-wide trait association discoveries. Here, we design, describe, and experimentally verify a new iteration of this technology, the Methylation Screening Array (MSA), to focus on human trait screening and discovery. This array utilizes extensive data from previous Infinium platform-based epigenome-wide association studies (EWAS). It incorporates knowledge from the latest single-cell and cell type-resolution whole genome methylome profiles. The MSA is engineered to achieve scalable screening of epigenetics-trait association in an ultra-high sample throughput. Our design encompassed diverse human trait associations, including those with genetic, cellular, environmental, and demographical variables and human diseases such as genetic, neurodegenerative, cardiovascular, infectious, and immune diseases. We comprehensively evaluated this array's reproducibility, accuracy, and capacity for cell-type deconvolution and supporting 5-hydroxymethylation profiling in diverse human tissues. Our first atlas data using this platform uncovered the complex chromatin and tissue contexts of DNA modification variations and genetic variants linked to human phenotypes.
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The gasotransmitter hydrogen sulfide (H2S) is thought to be involved in the post-translational modification of cysteine residues to produce reactive persulfides. A persulfide-specific chemoselective proteomics approach with mammalian cells has identified a broad range of zinc finger (ZF) proteins as targets of persulfidation. Parallel studies with isolated ZFs show that persulfidation is mediated by ZnII, O2, and H2S, with intermediates involving oxygen- and sulfur-based radicals detected by mass spectrometry and optical spectroscopies. A small molecule ZnII complex exhibits analogous reactivity with H2S and O2, giving a persulfidated product. These data show that ZnII is not just a biological structural element, but also plays a critical role in mediating H2S-dependent persulfidation. ZF persulfidation appears to be a general post-translational modification and a possible conduit for H2S signaling. This work has implications for our understanding of H2S-mediated signaling and the regulation of ZFs in cellular physiology and development.
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Sulfuro de Hidrógeno , Proteómica , Sulfuros , Dedos de Zinc , Zinc , Sulfuro de Hidrógeno/química , Sulfuro de Hidrógeno/metabolismo , Zinc/química , Humanos , Sulfuros/química , Procesamiento Proteico-PostraduccionalRESUMEN
Racial, ethnic, and socioeconomic disparities exist in the prevalence and natural history of chronic liver disease, access to care, and clinical outcomes. Solutions to improve health equity range widely, from digital health tools to policy changes. The current review outlines the disparities along the chronic liver disease health care continuum from screening and diagnosis to the management of cirrhosis and considerations of pre-liver and post-liver transplantation. Using a health equity research and implementation science framework, we offer pragmatic strategies to address barriers to implementing high-quality equitable care for patients with chronic liver disease.
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Continuidad de la Atención al Paciente , Disparidades en Atención de Salud , Hepatopatías , Humanos , Hepatopatías/terapia , Enfermedad Crónica , Trasplante de Hígado , Equidad en Salud , Accesibilidad a los Servicios de Salud , Cirrosis Hepática/terapiaRESUMEN
Importance: A new liver allocation policy was implemented by United Network for Organ Sharing (UNOS) in February 2020 with the stated intent of improving access to liver transplant (LT). There are growing concerns nationally regarding the implications this new system may have on LT costs, as well as access to a chance for LT, which have not been captured at a multicenter level. Objective: To characterize LT volume and cost changes across the US and within specific center groups and demographics after the policy implementation. Design, Setting, and Participants: This cross-sectional study collected and reviewed LT volume from multiple centers across the US and cost data with attention to 8 specific center demographics. Two separate 12-month eras were compared, before and after the new UNOS allocation policy: March 4, 2019, to March 4, 2020, and March 5, 2020, to March 5, 2021. Data analysis was performed from May to December 2022. Main Outcomes and Measures: Center volume, changes in cost. Results: A total of 22 of 68 centers responded comparing 1948 LTs before the policy change and 1837 LTs postpolicy, resulting in a 6% volume decrease. Transplants using local donations after brain death decreased 54% (P < .001) while imported donations after brain death increased 133% (P = .003). Imported fly-outs and dry runs increased 163% (median, 19; range, 1-75, vs 50, range, 2-91; P = .009) and 33% (median, 3; range, 0-16, vs 7, range, 0-24; P = .02). Overall hospital costs increased 10.9% to a total of $46â¯360â¯176 (P = .94) for participating centers. There was a 77% fly-out cost increase postpolicy ($10â¯600â¯234; P = .03). On subanalysis, centers with decreased LT volume postpolicy observed higher overall hospital costs ($41â¯720â¯365; P = .048), and specifically, a 122% cost increase for liver imports ($6â¯508â¯480; P = .002). Transplant centers from low-income states showed a significant increase in hospital (12%) and import (94%) costs. Centers serving populations with larger proportions of racial and ethnic minority candidates and specifically Black candidates significantly increased costs by more than 90% for imported livers, fly-outs, and dry runs despite lower LT volume. Similarly, costs increased significantly (>100%) for fly-outs and dry runs in centers from worse-performing health systems. Conclusions and Relevance: Based on this large multicenter effort and contrary to current assumptions, the new liver distribution system appears to place a disproportionate burden on populations of the current LT community who already experience disparities in health care. The continuous allocation policies being promoted by UNOS could make the situation even worse.
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OBJECTIVES: Describing our institution's off-label use of gabapentin to treat irritability after superior cavopulmonary connection surgery and its impact on subsequent opiate and benzodiazepine requirements. METHODS: This is a single-center retrospective cohort study including infants who underwent superior cavopulmonary connection operation between 2011 and 2019. RESULTS: Gabapentin was administered in 74 subjects (74/323, 22.9%) during the observation period, with a median (IQR) starting dose of 5.7 (3.3, 15.0) mg/kg/day and a maximum dose of 10.7 (5.5, 23.4) mg/kg/day. Infants who underwent surgery in 2015-19 were more likely to receive gabapentin compared with those who underwent surgery in 2011-14 (p < 0.0001). Infants prescribed gabapentin were younger at surgery (137 versus 146 days, p = 0.007) and had longer chest tube durations (1.8 versus 0.9 days, p < 0.001), as well as longer postoperative intensive care (5.8 versus 3.1 days, p < 0.0001) and hospital (11.5 versus 7.0 days, p < 0.0001) lengths of stays. The year of surgery was the only predisposing factor associated with gabapentin administration in multivariate analysis. In adjusted linear regression, infants prescribed gabapentin on postoperative day 0-4 (n = 64) had reduced benzodiazepine exposure in the following 3 days (-0.29 mg/kg, 95% CI -0.52 - -0.06, p = 0.01) compared with those not prescribed gabapentin, while no difference was seen in opioid exposure (p = 0.59). CONCLUSIONS: Gabapentin was used with increasing frequency during the study period. There was a modest reduction in benzodiazepine requirements associated with gabapentin administration and no reduction in opioid requirements. A randomised controlled trial could better assess gabapentin's benefits postoperatively in children with congenital heart disease.
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BACKGROUND: In May 2019, liver transplant (LT) allocation policy changed to limit MELD exception points for hepatocellular carcinoma (HCC) to median MELD at transplant minus three (MMaT-3). We evaluated this policy's impact on waitlist outcomes for HCC candidates, by race and ethnicity, hypothesizing that the introduction of the MMaT-3 reduced inequities in waitlist outcomes. METHODS: Retrospective cohort study of the Scientific Registry for Transplant Recipients, including all adult LT candidates (N = 10 751) who received HCC exception points from May 17, 2017 to May 18, 2019 (pre-policy; N = 6627) to May 19, 2019 to March 1, 2021 (post-policy; N = 4124). We compared incidence of LT and waitlist removal for death or becoming too sick pre- and post-policy for non-Hispanic White, non-Hispanic Black, Hispanic/Latinx, and Asian patients using competing risk regression adjusted for candidate characteristics. RESULTS: One-year cumulative incidence of LT decreased significantly pre-/post-policy among White (77.4% vs. 64.5%; p < .01) and Black (76.2% vs. 63.1%; p < .01) candidates only, while a 1-year incidence of death/non-LT waitlist removal decreased significantly only among Hispanics (13.4% vs. 7.5%; p < .01). After covariate adjustment, the effect of the policy change was a significantly decreased incidence of LT for White (SHR: .63 compared to pre-policy; p < .001), Black (SHR: .62; p < .001), and Asian (SHR: .68; p = .002), but no change for Hispanic patients. Only Hispanic patients had a significant decrease in death/waitlist removal after the policy change (SHR: .69; p = .04). Compared to White patients in the pre-policy era, Hispanic (SHR: .88, p < .007) and Asian candidates (SHR: .72; p < .001) had lower unadjusted incidence of LT. This disparity was mitigated in the post-policy era where Hispanic patients had higher likelihood of LT than Whites (SHR: 1.22; p = .002). For the outcome of death/non-LT waitlist removal, the only significant difference was a 42% lower incidence of waitlist removal for Asian compared to White patients in the post-policy era (SHR: .58; p = .03). CONCLUSION: Among LT recipients with HCC, racial/ethnic subpopulations were differentially affected by the MMAT-3 policy, resulting in a post-policy reduction of some of the previous disparities.
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Carcinoma Hepatocelular , Etnicidad , Neoplasias Hepáticas , Trasplante de Hígado , Obtención de Tejidos y Órganos , Listas de Espera , Humanos , Carcinoma Hepatocelular/cirugía , Carcinoma Hepatocelular/mortalidad , Masculino , Neoplasias Hepáticas/cirugía , Neoplasias Hepáticas/mortalidad , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Etnicidad/estadística & datos numéricos , Estudios de Seguimiento , Obtención de Tejidos y Órganos/estadística & datos numéricos , Pronóstico , Tasa de Supervivencia , Disparidades en Atención de Salud/estadística & datos numéricos , Adulto , Sistema de Registros/estadística & datos numéricos , Grupos Raciales/estadística & datos numéricos , AncianoRESUMEN
INTRODUCTION: Chronic exposure to ultraviolet light photoages skin. Retinol, a precursor molecule to retinoic acid that causes less irritation, is available as a nonprescription, cosmetic retinoid and improves collagen production, skin elasticity, and signs of photoaging. Advances in formulation science have allowed the production of stabilized bioactive retinol formulations. This integrated analysis aims to build on previous studies and further examine the comprehensive efficacy and tolerability of topical 0.1% stabilized bioactive retinol. METHODS: This analysis included 6 vehicle-controlled studies of 0.1% stabilized bioactive retinol in women with mild-to-moderate signs of photodamage. Across all studies, the same dermatologist investigator assessed overall photodamage; wrinkles on the forehead, cheeks, and undereye area; crow’s feet wrinkles and fine lines; lack of even skin tone; and brown spots at baseline and weeks 4, 8, and 12 on a numerical scale. Tolerability was also assessed. RESULTS: Participants (retinol, N=237; vehicle, N=234) had a mean (SD) age of 47.4 (6.6) years. Retinol induced greater improvements from baseline in all signs of photoaging vs vehicle as early as week 4 and through 12 weeks of application. Few participants experienced irritation; all events were mild to moderate and transient. The most common signs of irritation were erythema (n=2) and skin scaling/peeling (n=5). CONCLUSIONS: This pooled analysis of 6 vehicle-controlled clinical studies provides new evidence for the efficacy of 0.1% stabilized bioactive retinol in improving signs of photoaging without causing major irritation. Topical 0.1% stabilized bioactive retinol was well tolerated with only a few reported cases of skin irritation. J Drugs Dermatol. 2024;23(4): doi:10.36849/JDD.8124.
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Envejecimiento de la Piel , Vitamina A , Femenino , Humanos , Persona de Mediana Edad , Administración Cutánea , Método Doble Ciego , Retinoides , Resultado del Tratamiento , Tretinoina/efectos adversos , Adulto , Ensayos Clínicos Controlados como AsuntoRESUMEN
In the dairy industry bacteriophage (phage) contamination significantly impairs the production and quality of products like yogurt and cheese. To combat this issue, the strains of bacteria used as starter cultures possess mechanisms that make them resistant to phage infection, such as envelope resistance, or processes that render them immune to phage infection, such as restriction-modification and CRISPR-Cas. Lactococcus lactis, used to manufacture cheese and other dairy products, can also block the reproduction of infecting phages by abortive infection (Abi), a process in which phage-infected cells die before the phage replicate. We employ mathematical-computer simulation models and experiments with two Lactococcus lactis strains and two lytic phages to investigate the conditions under which Abi can limit the proliferation of phages in L. lactis populations and prevent the extinction of their populations by these viruses. According to our model, if Abi is almost perfect and there are no other populations of bacteria capable of supporting the replication of the L. lactis phages, Abi can protect bacterial populations from succumbing to infections with these viruses. This prediction is supported by the results of our experiment, which indicate that Abi can help protect L. lactis populations from extinction by lytic phage infections. However, our results also predict abortive infection is only one element of L. lactis defenses against phage infection. Mutant phages that can circumvent the Abi systems of these bacteria emerge. The survival of L. lactis populations then depends on the evolution of envelope mutants that are resistant to the evolved host-range phage.
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Bacteriófagos , Lactococcus lactis , Bacteriófagos/genética , Lactococcus lactis/genética , Simulación por Computador , Proteínas Bacterianas , BacteriasRESUMEN
Helicobacter pylori (HP) is a causative agent in gastric cancer (GC).1 In the United States, HP is more prevalent in racial and ethnic minorities, including African Americans, Asian Americans, Latinos, and immigrants, the same groups that are more likely to develop and die from GC.2 Although screening for HP is not presently performed in the United States, there are plausible benefits to doing so, because HP is considered a group 1 carcinogen by the World Health Organization, and its link to GC parallels that of human papilloma virus and cervical cancer.1 HP eradication as a means of preventing GC also fulfils the Wilson and Jungner criteria for a successful screening program, and literature has consistently demonstrated that HP eradication reduces GC risk and death from GC.3 In fact, in countries with a high burden of GC, HP eradication is considered primary prevention for GC. As such, targeted HP testing in the United States may reduce GC burden in high-risk groups.4 We evaluate the results of community-based HP testing in an at-risk, underserved population.
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The nature of the axial ligand in high-valent iron-oxo heme enzyme intermediates and related synthetic catalysts is a critical structural element for controlling proton-coupled electron-transfer (PCET) reactivity of these species. Herein, we describe the generation and characterization of three new 6-coordinate, iron(IV)-oxo porphyrinoid-π-cation-radical complexes and report their PCET reactivity together with a previously published 5-coordinate analogue, FeIV(O)(TBP8Cz+â¢) (TBP8Cz = octakis(p-tert-butylphenyl)corrolazinato3-) (2) (Cho, K. A high-valent iron-oxo corrolazine activates C-H bonds via hydrogen-atom transfer. J. Am. Chem. Soc. 2012, 134, 7392-7399). The new complexes FeIV(O)(TBP8Cz+â¢)(L) (L = 1-methyl imidazole (1-MeIm) (4a), 4-dimethylaminopyridine (DMAP) (4b), cyanide (CN-)(4c)) can be generated from either oxidation of the ferric precursors or by addition of L to the Compound-I (Cpd-I) analogue at low temperatures. These complexes were characterized by UV-vis, electron paramagnetic resonance (EPR), and Mössbauer spectroscopies, and cryospray ionization mass spectrometry (CSI-MS). Kinetic studies using 4-OMe-TEMPOH as a test substrate indicate that coordination of a sixth axial ligand dramatically lowers the PCET reactivity of the Cpd-I analogue (rates up to 7000 times slower). Extensive density functional theory (DFT) calculations together with the experimental data show that the trend in reactivity with the axial ligands does not correlate with the thermodynamic driving force for these reactions or the calculated strengths of the O-H bonds being formed in the FeIV(O-H) products, pointing to non-Bell-Evans-Polanyi behavior. However, the PCET reactivity does follow a trend with the bracketed reduction potential of Cpd-I analogues and calculated electron affinities. The combined data suggest a concerted mechanism (a concerted proton electron transfer (CPET)) and an asynchronous movement of the electron/proton pair in the transition state.
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The Fontan operation is the current standard of care for single-ventricle congenital heart disease. Individuals with a Fontan circulation (FC) exhibit central venous hypertension and face life-threatening complications of hepatic fibrosis, known as Fontan-associated liver disease (FALD). The fundamental biology and mechanisms of FALD are little understood. Here, we generated a transcriptomic and epigenomic atlas of human FALD at single-cell resolution using multiomic snRNA-ATAC-seq. We found profound cell type-specific transcriptomic and epigenomic changes in FC livers. Central hepatocytes (cHep) exhibited the most substantial changes, featuring profound metabolic reprogramming. These cHep changes preceded substantial activation of hepatic stellate cells and liver fibrosis, suggesting cHep as a potential first "responder" in the pathogenesis of FALD. We also identified a network of ligand-receptor pairs that transmit signals from cHep to hepatic stellate cells, which may promote their activation and liver fibrosis. We further experimentally demonstrated that activins A and B promote fibrotic activation in vitro and identified mechanisms of activin A's transcriptional activation in FALD. Together, our single-cell transcriptomic and epigenomic atlas revealed mechanistic insights into the pathogenesis of FALD and may aid identification of potential therapeutic targets.
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Procedimiento de Fontan , Células Estrelladas Hepáticas , Hepatocitos , Hepatopatías , Humanos , Epigenómica , Procedimiento de Fontan/efectos adversos , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Hepatocitos/metabolismo , Hígado/patología , Hígado/metabolismo , Cirrosis Hepática/etiología , Cirrosis Hepática/patología , Hepatopatías/etnología , Hepatopatías/patología , Multiómica , Análisis de la Célula Individual , TranscriptomaRESUMEN
The Liver Simulated Allocation Model (LSAM) is used to evaluate proposed organ allocation policies. Although LSAM has been shown to predict the directionality of changes in transplants and nonused organs, the magnitude is often overestimated. One reason is that policymakers and researchers using LSAM assume static levels of organ donation and center behavior because of challenges with predicting future behavior. We sought to assess the ability of LSAM to account for changes in organ donation and organ acceptance behavior using LSAM 2019. We ran 1-year simulations with the default model and then ran simulations changing donor arrival rates (ie, organ donation) and center acceptance behavior. Changing the donor arrival rate was associated with a progressive simulated increase in transplants, with corresponding simulated decreases in waitlist deaths. Changing parameters related to organ acceptance was associated with important changes in transplants, nonused organs, and waitlist deaths in the expected direction in data simulations, although to a much lesser degree than changing the donor arrival rate. Increasing the donor arrival rate was associated with a marked decrease in the travel distance of donor livers in simulations. In conclusion, we demonstrate that LSAM can account for changes in organ donation and organ acceptance in a manner aligned with historical precedent that can inform future policy analyses. As Scientific Registry of Transplant Recipients develops new simulation programs, the importance of considering changes in donation and center practice is critical to accurately estimate the impact of new allocation policies.