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1.
J Biol Chem ; 300(5): 107267, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38583863

RESUMO

Phospholamban (PLB) is a transmembrane micropeptide that regulates the sarcoplasmic reticulum Ca2+-ATPase (SERCA) in cardiac muscle, but the physical mechanism of this regulation remains poorly understood. PLB reduces the Ca2+ sensitivity of active SERCA, increasing the Ca2+ concentration required for pump cycling. However, PLB does not decrease Ca2+ binding to SERCA when ATP is absent, suggesting PLB does not inhibit SERCA Ca2+ affinity. The prevailing explanation for these seemingly conflicting results is that PLB slows transitions in the SERCA enzymatic cycle associated with Ca2+ binding, altering transport Ca2+ dependence without actually affecting the equilibrium binding affinity of the Ca2+-coordinating sites. Here, we consider another hypothesis, that measurements of Ca2+ binding in the absence of ATP overlook important allosteric effects of nucleotide binding that increase SERCA Ca2+ binding affinity. We speculated that PLB inhibits SERCA by reversing this allostery. To test this, we used a fluorescent SERCA biosensor to quantify the Ca2+ affinity of non-cycling SERCA in the presence and absence of a non-hydrolyzable ATP-analog, AMPPCP. Nucleotide activation increased SERCA Ca2+ affinity, and this effect was reversed by co-expression of PLB. Interestingly, PLB had no effect on Ca2+ affinity in the absence of nucleotide. These results reconcile the previous conflicting observations from ATPase assays versus Ca2+ binding assays. Moreover, structural analysis of SERCA revealed a novel allosteric pathway connecting the ATP- and Ca2+-binding sites. We propose this pathway is disrupted by PLB binding. Thus, PLB reduces the equilibrium Ca2+ affinity of SERCA by interrupting allosteric activation of the pump by ATP.


Assuntos
Proteínas de Ligação ao Cálcio , Cálcio , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático , Animais , Humanos , Trifosfato de Adenosina/metabolismo , Regulação Alostérica , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/química , Miocárdio/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/química , Cães , Células HEK293 , Modelos Moleculares , Estrutura Terciária de Proteína
2.
Hepatology ; 80(1): 87-101, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38381705

RESUMO

BACKGROUND AND AIMS: Despite the substantial impact of environmental factors, individuals with a family history of liver cancer have an increased risk for HCC. However, genetic factors have not been studied systematically by genome-wide approaches in large numbers of individuals from European descent populations (EDP). APPROACH AND RESULTS: We conducted a 2-stage genome-wide association study (GWAS) on HCC not affected by HBV infections. A total of 1872 HCC cases and 2907 controls were included in the discovery stage, and 1200 HCC cases and 1832 controls in the validation. We analyzed the discovery and validation samples separately and then conducted a meta-analysis. All analyses were conducted in the presence and absence of HCV. The liability-scale heritability was 24.4% for overall HCC. Five regions with significant ORs (95% CI) were identified for nonviral HCC: 3p22.1, MOBP , rs9842969, (0.51, [0.40-0.65]); 5p15.33, TERT , rs2242652, (0.70, (0.62-0.79]); 19q13.11, TM6SF2 , rs58542926, (1.49, [1.29-1.72]); 19p13.11 MAU2 , rs58489806, (1.53, (1.33-1.75]); and 22q13.31, PNPLA3 , rs738409, (1.66, [1.51-1.83]). One region was identified for HCV-induced HCC: 6p21.31, human leukocyte antigen DQ beta 1, rs9275224, (0.79, [0.74-0.84]). A combination of homozygous variants of PNPLA3 and TERT showing a 6.5-fold higher risk for nonviral-related HCC compared to individuals lacking these genotypes. This observation suggests that gene-gene interactions may identify individuals at elevated risk for developing HCC. CONCLUSIONS: Our GWAS highlights novel genetic susceptibility of nonviral HCC among European descent populations from North America with substantial heritability. Selected genetic influences were observed for HCV-positive HCC. Our findings indicate the importance of genetic susceptibility to HCC development.


Assuntos
Carcinoma Hepatocelular , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/genética , Masculino , Feminino , Pessoa de Meia-Idade , América do Norte/epidemiologia , Estudos de Casos e Controles , Polimorfismo de Nucleotídeo Único , Idoso , Loci Gênicos , População Branca/genética
3.
Ann Surg Oncol ; 31(4): 2632-2639, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38319513

RESUMO

BACKGROUND: The management of invasive intraductal papillary mucinous cystic neoplasm (I-IPMN) does not differ from de novo pancreatic ductal adenocarcinoma (PDAC); however, I-IPMNs are debated to have better prognosis. Despite being managed similarly to PDAC, no data are available on the response of I-IPMN to neoadjuvant chemotherapy. METHODS: All patients undergoing pancreatic resection for a pancreatic adenocarcinoma from 2011 to 2022 were included. The PDAC and I-IPMN cohorts were compared to evaluate response to neoadjuvant therapy (NAT) and overall survival (OS). RESULTS: This study included 1052 PDAC patients and 105 I-IPMN patients. NAT was performed in 25% of I-IPMN patients and 65% of PDAC patients. I-IPMN showed a similar pattern of pathological response to NAT compared with PDAC (p = 0.231). Furthermore, positron emission tomography (PET) response (71% vs. 61%; p = 0.447), CA19.9 normalization (85% vs. 76%, p = 0.290), and radiological response (32% vs. 37%, p = 0.628) were comparable between I-IPMN and PDAC. A significantly higher OS and disease-free survival (DFS) of I-IPMN was denoted by Kaplan-Meier analysis, with a p-value of < 0.001 in both plots. In a multivariate analysis, I-IPMN histology was independently associated with lower risk of recurrence and death. CONCLUSIONS: I-IPMN patients have a longer OS and DFS after surgical treatment when compared with PDAC patients. The more favorable oncologic outcome of I-IPMNs does not seem to be related to early detection, as I-IPMN histological subclass is independently associated with a lower risk of disease recurrence. Moreover, neoadjuvant effect on I-IPMN was non-inferior to PDAC in terms of pathological, CA19.9, PET, and radiological response and thus can be considered in selected patients.


Assuntos
Adenocarcinoma Mucinoso , Adenocarcinoma Papilar , Adenocarcinoma , Carcinoma Ductal Pancreático , Neoplasias Intraductais Pancreáticas , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/cirurgia , Adenocarcinoma/patologia , Terapia Neoadjuvante , Adenocarcinoma Mucinoso/tratamento farmacológico , Adenocarcinoma Mucinoso/cirurgia , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/cirurgia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/cirurgia , Adenocarcinoma Papilar/patologia , Estudos Retrospectivos
4.
Ann Surg Oncol ; 31(8): 5370-5376, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38689169

RESUMO

BACKGROUND: Cytoreductive hepatectomy can improve survival and symptoms of hormonal excess in patients with small intestinal neuroendocrine tumor (siNET) liver metastases, but whether to proceed when peritoneal metastases are encountered at the time of planned cytoreductive hepatectomy is controversial. METHODS: This was a retrospective review of patients who underwent surgical management of metastatic siNETs at Mayo Clinic between 2000 and 2020. Patients who underwent cytoreductive operation for isolated liver metastases or both liver and peritoneal metastases were compared. RESULTS: Of 261 patients who underwent cytoreductive operation for siNETs, 211 had isolated liver metastases and 50 had liver and peritoneal metastases. Complete cytoreduction was achieved in 78% of patients with isolated liver metastases and 56% of those with liver and peritoneal metastases (p = 0.002). After complete cytoreduction, median overall survival (OS) was 11.5 years for isolated liver metastases and 11.2 years for liver and peritoneal metastases (p = 0.10), and relief of carcinoid syndrome was ≥ 97% in both groups. After incomplete cytoreduction with debulking of > 90% of hepatic disease and/or closing Lyon score of 1-2, median OS was 6.4 years for isolated liver metastases and 7.1 years for liver and peritoneal metastases (p = 0.12). CONCLUSIONS: Patients with siNETs metastatic to both the liver and peritoneum have favorable outcomes after aggressive surgical cytoreduction, with the best outcomes observed after complete cytoreduction. Therefore, the presence of peritoneal metastases should not by itself preclude surgical cytoreduction in this population.


Assuntos
Procedimentos Cirúrgicos de Citorredução , Neoplasias Intestinais , Neoplasias Hepáticas , Tumores Neuroendócrinos , Neoplasias Peritoneais , Humanos , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Feminino , Neoplasias Peritoneais/secundário , Neoplasias Peritoneais/cirurgia , Masculino , Tumores Neuroendócrinos/cirurgia , Tumores Neuroendócrinos/patologia , Tumores Neuroendócrinos/secundário , Estudos Retrospectivos , Pessoa de Meia-Idade , Neoplasias Intestinais/cirurgia , Neoplasias Intestinais/patologia , Neoplasias Intestinais/secundário , Taxa de Sobrevida , Idoso , Seguimentos , Intestino Delgado/cirurgia , Intestino Delgado/patologia , Hepatectomia/mortalidade , Prognóstico , Adulto
5.
Ann Surg Oncol ; 31(8): 4931-4941, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38717544

RESUMO

BACKGROUND: Surgical cytoreduction for neuroendocrine tumor liver metastasis (NETLM) consistently shows positive long-term outcomes. Despite reservations in guidelines for surgery when the primary tumor is unidentified (UP-NET), this study compared the surgical and oncologic long-term outcomes between patients with these rare cases undergoing cytoreductive surgery and patients who had liver resection for known primaries. METHODS: The study identified 32 unknown primary liver metastases (UP-NETLM) in 522 retrospectively evaluated patients who underwent resection of well-differentiated NETLM between January 2000 and December 2020. Tumor and patient characteristics were compared with those in 490 cases of liver metastasis from small intestinal (SI-NETLM) or pancreatic (pNETLM) primaries. Survival analysis was performed to highlight long-term outcome differences. Surgical outcomes were compared between liver resections alone and simultaneous primary resections to assess surgical risk distinctions. RESULTS: The UP-NET patients had fewer NETLMs (p = 0.004), which on the average were larger than SI-NETLMs or pNETLMs (p = 0.002). Expression of Ki-67 was balanced among the groups. Major hepatectomy was performed more often in the UP-NETLM group (p = 0.017). The 10-year survival rate of 53% for UP-NETLM was comparable with that for SI-NETML (58%; p = 0.463) and pNETLMs (47%; p = 0.497). The median hepatic progression-free survival was 26 months for the UP-NETLM patients and 25 months for the SI-NETLM patients compared to 12 months for the pNETLM patients (p < 0.001). Perioperative mortality was lower than 2%, and severe postoperative morbidity occurred in 21%, similarly distributed among all the groups. CONCLUSION: The surgical risk and long-term outcomes for the UP-NETLM patients were comparable with those for other NETLM cases, affirming the validity of equally aggressive surgical cytoreduction as a therapeutic option in carefully selected cases.


Assuntos
Procedimentos Cirúrgicos de Citorredução , Hepatectomia , Neoplasias Hepáticas , Neoplasias Primárias Desconhecidas , Tumores Neuroendócrinos , Humanos , Masculino , Feminino , Hepatectomia/mortalidade , Hepatectomia/métodos , Tumores Neuroendócrinos/cirurgia , Tumores Neuroendócrinos/patologia , Pessoa de Meia-Idade , Procedimentos Cirúrgicos de Citorredução/mortalidade , Estudos Retrospectivos , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/secundário , Taxa de Sobrevida , Neoplasias Primárias Desconhecidas/cirurgia , Neoplasias Primárias Desconhecidas/patologia , Idoso , Seguimentos , Adulto , Prognóstico
6.
Ann Surg Oncol ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38896229

RESUMO

BACKGROUND: Posthepatectomy liver failure (PHLF), complications of portal hypertension, and disease recurrence determine the outcome for hepatocellular carcinoma (HCC) patients undergoing liver resection. This study aimed to evaluate the von Willebrand factor antigen (vWF-Ag) as a non-invasive test for clinically significant portal hypertension (CSPH) and a predictive biomarker for time to recurrence (TTR) and overall survival (OS). METHODS: The study recruited 72 HCC patients with detailed preoperative workup from a prospective trial (NCT02118545) and followed for complications, TTR, and OS. Additionally, 163 compensated patients with resectable HCC were recruited to evaluate vWF-Ag cutoffs for ruling out or ruling in CSPH. Finally, vWF-Ag cutoffs were prospectively evaluated in an external validation cohort of 34 HCC patients undergoing liver resection. RESULTS: In receiver operating characteristic (ROC) analyses, vWF-Ag (area under the curve [AUC], 0.828) was similarly predictive of PHLF as indocyanine green clearance (disappearance rate: AUC, 0.880; retention rate: AUC, 0.894), whereas computation of future liver remnant was inferior (AUC, 0.756). Cox-regression showed an association of vWF-Ag with TTR (per 10%: hazard ratio [HR], 1.056; 95% confidence interval [CI] 1.017-1.097) and OS (per 10%: HR, 1.067; 95% CI 1.022-1.113). In the analyses, VWF-Ag yielded an AUC of 0.824 for diagnosing CSPH, with a vWF-Ag of 182% or lower ruling out and higher than 291% ruling in CSPH. Therefore, a highest-risk group (> 291%, 9.7% of patients) with a 57.1% incidence of PHLF was identified, whereas no patient with a vWF-Ag of 182% or lower (52.7%) experienced PHLF. The predictive value of vWF-Ag for PHLF and OS was externally validated. CONCLUSION: For patients with resectable HCC, VWF-Ag allows for simplified preoperative risk stratification. Patients with vWF-Ag levels higher than 291% might be considered for alternative treatments, whereas vWF-Ag levels of 182% or lower identify patients best suited for surgery.

7.
Surg Endosc ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39117957

RESUMO

BACKGROUND: Despite a growing body of literature supporting the safety of robotic hepatopancreatobiliary (HPB) procedures, the adoption of minimally invasive techniques in HPB surgery has been slow compared to other specialties. We aimed to identify barriers to implementing robotic assisted surgery (RAS) in HPB and present a framework that highlights opportunities to improve adoption. METHODS: A modified nominal group technique guided by a 13-question framework was utilized. The meeting session was guided by senior authors, and field notes were also collected. Results were reviewed and free text responses were analyzed for major themes. A follow-up priority setting survey was distributed to all participants based on meeting results. RESULTS: Twenty three surgeons with varying robotic HPB experience from different practice settings participated in the discussion. The majority of surgeons identified operating room efficiency, having a dedicated operating room team, and the overall hospital culture and openness to innovation as important facilitators of implementing a RAS program. In contrast, cost, capacity building, disparities/risk of regionalization, lack of evidence, and time/effort were identified as the most significant barriers. When asked to prioritize the most important issues to be addressed, participants noted access and availability of the robot as the most important issue, followed by institutional support, cost, quality of supporting evidence, and need for robotic training. CONCLUSIONS: This study reports surgeons' perceptions of major barriers to equitable access and increased implementation of robotic HPB surgery. To overcome such barriers, defining key resources, adopting innovative solutions, and developing better methods of collecting long term data should be the top priorities.

8.
Surg Endosc ; 38(8): 4365-4373, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38886227

RESUMO

BACKGROUND: Although minimally invasive hepato-pancreato-biliary (MIS HPB) surgery can be performed with good outcomes, there are currently no standardized requirements for centers or surgeons who wish to implement MIS HPB surgery. The aim of this study was to create a consensus statement regarding safe dissemination and implementation of MIS HPB surgical programs. METHODS: Sixteen key questions regarding safety in MIS HPB surgery were generated after a focused literature search and iterative review by three field experts. Participants for the working group were then selected using sequential purposive sampling and snowball techniques. Review of the 16 questions took place over a single 2-h meeting. The senior author facilitated the session, and a modified nominal group technique was used. RESULTS: Twenty three surgeons were in attendance. All participants agreed or strongly agreed that formal guidelines should exist for both institutions and individual surgeons interested in implementing MIS HPB surgery and that routine monitoring and reporting of institutional and surgeon technical outcomes should be performed. Regarding volume cutoffs, most participants (91%) agreed or strongly agreed that a minimum annual institutional volume cutoff for complex MIS HPB surgery, such as major hepatectomy or pancreaticoduodenectomy, should exist. A smaller proportion (74%) agreed or strongly agreed that a minimum annual surgeon volume requirement should exist. The majority of participants agreed or strongly agreed that surgeons were responsible for defining (100%) and enforcing (78%) guidelines to ensure the overall safety of MIS HPB programs. Finally, formal MIS HPB training, minimum case volume requirements, institutional support and infrastructure, and mandatory collection of outcomes data were all recognized as important aspects of safe implementation of MIS HPB surgery. CONCLUSIONS: Safe implementation of MIS HPB surgery requires a thoughtful process that incorporates structured training, sufficient volume and expertise, a proper institutional ecosystem, and monitoring of outcomes.


Assuntos
Procedimentos Cirúrgicos Minimamente Invasivos , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/normas , Segurança do Paciente/normas , Procedimentos Cirúrgicos do Sistema Biliar/métodos , Hepatectomia/métodos , Hepatectomia/normas , Hepatectomia/efeitos adversos , Consenso
9.
JAMA ; 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39158894

RESUMO

Importance: Tranexamic acid reduces bleeding and blood transfusion in many types of surgery, but its effect in patients undergoing liver resection for a cancer-related indication remains unclear. Objective: To determine whether tranexamic acid reduces red blood cell transfusion within 7 days of liver resection. Design, Setting, and Participants: Multicenter randomized clinical trial of tranexamic acid vs placebo conducted from December 1, 2014, to November 8, 2022, at 10 hepatopancreaticobiliary sites in Canada and 1 site in the United States, with 90-day follow-up. Participants, clinicians, and data collectors were blinded to allocation. A volunteer sample of 1384 patients undergoing liver resection for a cancer-related indication met eligibility criteria and consented to randomization. Interventions: Tranexamic acid (1-g bolus followed by 1-g infusion over 8 hours; n = 619) or matching placebo (n = 626) beginning at induction of anesthesia. Main Outcomes and Measures: The primary outcome was receipt of red blood cell transfusion within 7 days of surgery. Results: The primary analysis included 1245 participants (mean age, 63.2 years; 39.8% female; 56.1% with a diagnosis of colorectal liver metastases). Perioperative characteristics were similar between groups. Red blood cell transfusion occurred in 16.3% of participants (n = 101) in the tranexamic acid group and 14.5% (n = 91) in the placebo group (odds ratio, 1.15 [95% CI, 0.84-1.56]; P = .38; absolute difference, 2% [95% CI, -2% to 6%]). Measured intraoperative blood loss (tranexamic acid, 817.3 mL; placebo, 836.7 mL; P = .75) and total estimated blood loss over 7 days (tranexamic acid, 1504.0 mL; placebo, 1551.2 mL; P = .38) were similar between groups. Participants receiving tranexamic acid experienced significantly more complications compared with placebo (odds ratio, 1.28 [95% CI, 1.02-1.60]; P = .03), with no significant difference in venous thromboembolism (odds ratio, 1.68 [95% CI, 0.95-3.07]; P = .08). Conclusions and Relevance: Among patients undergoing liver resection for a cancer-related indication, tranexamic acid did not reduce bleeding or blood transfusion but increased perioperative complications. Trial Registration: ClinicalTrials.gov Identifier: NCT02261415.

14.
Adv Surg ; 58(1): 311-327, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39089784

RESUMO

The evolution of laparoscopic liver surgery, originating in the 1990s, has been marked by significant advancements and milestones, overcoming initial technical hurdles and gaining widespread acceptance within the surgical community as a precise and safe alternative to open procedures. Along this journey, numerous challenges emerged, leading to the accumulation of evidence and the development of guidelines aimed at assisting surgeons in determining the safety, suitability, and complexity of laparoscopic liver resection. This chapter provides a thorough examination of key aspects of laparoscopic liver resection, including difficulty scoring systems, criteria for patient selection, technical considerations, outcomes across different types of liver lesions, and the innovative solutions developed to address challenges, thus offering a comprehensive overview of laparoscopic liver resection, and highlighting its evolving significance in modern hepatobiliary surgery.


Assuntos
Hepatectomia , Laparoscopia , Seleção de Pacientes , Humanos , Laparoscopia/métodos , Hepatectomia/métodos , Neoplasias Hepáticas/cirurgia , Hepatopatias/cirurgia , Resultado do Tratamento
15.
Artigo em Inglês | MEDLINE | ID: mdl-38739530

RESUMO

PURPOSE: To determine the effectiveness of the correction of corneal astigmatism utilizing the Alcon Image Guidance system (Ft. Worth, Texas) versus manual marking in the orientation of femtosecond laser-assisted astigmatic keratotomy incisions. SETTING: This study was based in a private practice in Albany, New York, USA. DESIGN: Retrospective review of patients undergoing FLACS from January 2018 to June 2022. METHODS: Patients who underwent FLACS with Image Guidance (IG) and without IG were investigated. Variables including pre-operative K values, cylinder, spherical equivalent (SE), and visual acuity (VA) were collected, as well as the cyclorotation angle delta registered by IG, post- operative refractive cylinder, SE, and VA. The primary outcome was post-operative refractive cylinder in patients with IG compared to those without IG. RESULTS: A total of 160 eyes were included, with 103 eyes who had IG and 57 eyes who did not have IG. Post-operative cylinder was similar in those with IG (0.31 +/- 0.36 D) compared to those without IG (0.31 +/- 0.37 D) (p=0.97). Average cyclorotation in the IG group was 2.82 ± 3.03 degrees. When cyclorotation was stratified into three groups (<2.8 degrees, 2.8-8.5 degrees, >8.5 degrees), no differences were found in post-operative refractive cylinder (p=0.35). CONCLUSIONS: Patients who underwent FLACS with Image Guidance had similar post-operative cylinder outcomes compared to those without Image Guidance. This study suggests that the accommodation of cyclotorsion using an advanced image guidance system is similar to that obtained with manual marking techniques in patients having 2 diopters or less of astigmatism corrected.

16.
Artigo em Inglês | MEDLINE | ID: mdl-39054039

RESUMO

Forensic psychiatry fellowship programs recruit applicants through a nonstandardized process that differs by program. Although there are deadlines, informal guidance, and more recent communication guidelines, perceived differences in recruitment practices persist between geographic regions, small and large programs, and newer and more well-established programs. In the wake of a survey of fellowship applicants that found mixed opinions surrounding the application process, U.S. forensic fellowship directors undertook a mixed method quantitative-qualitative survey of their colleagues to assess interest in a match as a potential improvement and factors influencing that interest (e.g., program size, age, and unfilled positions). With responses from all 46 active U.S. programs, results indicated broad support for principles of fairness, transparency, and minimizing pressure on applicants, with an almost perfectly divided interest in a match. Respondents supported the use of a centralized database to standardize the application process and favored certain exceptions for internal applicants. Hypotheses about the reasons underlying program directors' attitudes toward a match did not yield significant results, with only the size of a program approaching significance. This novel comprehensive survey of forensic fellowship directors offers a model for assessing and monitoring the evolution of application processes for medical subspecialties interested in expanding and improving their recruitment.

17.
Gastro Hep Adv ; 3(3): 426-439, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39131140

RESUMO

Background and Aims: Effective approaches for prevention of hepatocellular carcinoma (HCC) will have a significant impact on HCC-related mortality. There are strong preclinical data and rationale to support targeting epidermal growth factor receptor (EGFR) for HCC chemoprevention. Small molecule inhibitors of EGFR have been Food and Drug Administration-approved for cancer therapy, which provides an opportunity to repurpose one of these drugs for chemoprevention of HCC. Unfortunately, the frequency of side effects associated with administration of these drugs at oncology doses renders them ineffective for chemoprevention. This clinical trial assesses whether lower doses of one of these inhibitors, erlotinib, still engages EGFR in the liver to block signaling (eg, EGFR phosphorylation). The objective of this clinical trial was determination of a safe and minimum effective dose of erlorinib for which ≥ 50% reduction phospho-EGFR immunohistochemical staining in the liver was observed. Methods: Forty six participants were preregistered and 25 participants were registered in this multicenter trial. By dose de-escalation trial design, cohorts of participants received a 7-day course of erlotinib 75 mg/day, 50 mg/day or 25 mg/day with liver tissue acquisition prior to and after erlotinib. Results: A ≥50% reduction phospho-EGFR immunohistochemical staining in the liver was observed in a minimum of 40% of participants (predetermined threshhold) at each of the dose levels. Erlotinib was very well tolerated with few side effects observed, particularly at the dose of 25 mg/day. Favorable modulation of the Prognostic Liver Signature was observed in participants who received erlotinib. Conclusion: These data support the selection of erlotinib doses as low as 25 mg/day of for a longer intervention to assess for evidence of efficacy as an HCC chemoprevention drug (ClinicalTrials.govNCT02273362).

18.
Nat Struct Mol Biol ; 31(3): 413-423, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38177683

RESUMO

Escherichia coli Septu system, an anti-phage defense system, comprises two components: PtuA and PtuB. PtuA contains an ATPase domain, while PtuB is predicted to function as a nuclease. Here we show that PtuA and PtuB form a stable complex with a 6:2 stoichiometry. Cryo-electron microscopy structure of PtuAB reveals a distinctive horseshoe-like configuration. PtuA adopts a hexameric arrangement, organized as an asymmetric trimer of dimers, contrasting the ring-like structure by other ATPases. Notably, the three pairs of PtuA dimers assume distinct conformations and fulfill unique roles in recruiting PtuB. Our functional assays have further illuminated the importance of the oligomeric assembly of PtuAB in anti-phage defense. Moreover, we have uncovered that ATP molecules can directly bind to PtuA and inhibit the activities of PtuAB. Together, the assembly and function of the Septu system shed light on understanding other ATPase-containing systems in bacterial immunity.


Assuntos
Bacteriófagos , Inflamassomos , Microscopia Crioeletrônica , Bacteriófagos/metabolismo , Adenosina Trifosfatases/metabolismo , Escherichia coli/metabolismo
19.
J Gastrointest Surg ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38906319

RESUMO

BACKGROUND: Metastasis or recurrence of pancreatic neuroendocrine tumors (pNETs) after pancreatectomy is an important source of postsurgical morbidity. This study aimed to define disease-free survival (DFS) in this population. METHODS: Patients who underwent pancreatectomy for pNETs between January 2005 and January 2022 were included. Clinicopathologic and survival data were collected, and the primary endpoint was DFS. Kaplan-Meier survival analysis and Cox proportional hazards regression modeling were performed. RESULTS: Of the 223 patients, 144 (65%) distal/subtotal/partial pancreatectomies, 71 (32%) pancreaticoduodenectomies, 6 (3%) total pancreatectomies, and 2 (1%) enucleations were performed. Of the 223 patients, 45 (20%) experienced disease recurrence or metastasis after index pancreatectomy during the 17 years of the study. Nonfunctional pNETs (162 [73%]) were more common than hormonally functional subtypes. The 2- and 5-year DFSs were 82% and 76%, respectively. Kaplan-Meier analysis demonstrated that N1 node positive disease, size of ≥ 4 cm, lymphovascular invasion, perineural invasion, Ki-67 of ≥ 20%, and nonfunctional pNETs are significantly associated with a lower DFS (P < .05). Univariate Cox analysis identified the following predictors to be significantly associated with poorer DFS: larger tumor size (hazard ratio [HR], 1.16; 95% CI, 1.04-1.28), Ki-67 index of ≥ 20% (HR, 4.93; 95% CI, 2.00-11.44), perineural invasion (HR, 3.23; 95% CI, 1.40-7.89), open surgery (HR, 3.34; 95% CI, 1.03-1.33), node-positive disease (HR, 5.27; 95% CI, 2.28-13.26), and increased body mass index (HR, 1.10; 95% CI, 1.03-1.17) (P < .05). CONCLUSION: Of note, 1 in 5 patients who underwent resection developed recurrence or metastasis after pancreatectomy. Prognostic predictors of DFS in pNETs could help optimize treatment and enhance follow-up protocols to improve quality and reduce morbidity.

20.
Cancers (Basel) ; 16(15)2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39123448

RESUMO

Biliary tract cancers, including cholangiocarcinoma, gallbladder, and ampulla of Vater cancers, rank second among hepatobiliary cancers, known for their poor prognoses. The United States has witnessed a notable increase in intrahepatic cholangiocarcinoma incidence. This study examines the incidence and survival outcomes of biliary tract cancers in Olmsted County, Minnesota from 1976 to 2018. Using data from the Rochester Epidemiology Project (REP), residents aged 20 and above were analyzed across four eras. Incidence rates were calculated and adjusted for age and sex, and temporal trends were assessed using Poisson regression. Intrahepatic cholangiocarcinoma exhibited a significant escalation in incidence rates over time, while gallbladder cancers showed a decline among women. Median survival times for biliary tract cancers notably improved. These findings confirm the rising incidence of intrahepatic cholangiocarcinoma and suggest improving survival rates. Nevertheless, the overall prognosis for biliary tract cancers remains very poor, emphasizing the continual need for enhanced management strategies and further research.

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