116 research outputs found
Oncosurgical approach to colorectal liver metastases
Spitalul Universitar Vall d'Hebron, Departamentul Chirurgie HBP şi Transplantologie, Barcelona, Spania, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Rezumat: Pacienţii cu metastaze hepatice din cancerul colorectal (CCR) reprezintă o provocare majoră în sănătatea publică cu
aproximativ 1,2 milioane cazuri de CCR anual în lume. Rezecţia metastazelor hepatice de origine colorectală (MHCR) este
singurul tratament care oferă posibilitatea de vindecare şi a prezentat beneficii clare de supravieţuire. Totuşi, doar 10-20% din
pacienţii cu MHCR sunt eligibili de această procedură în avans. Pe parcursul ultimii decade, au avut loc progrese esențiale în
managementul MHCR care vizează trei domenii: oncologia, radiologia şi chirurgia. Aceste progrese au condus la creşterea ratei
de rezecţie până la 20-30% din cazuri cu o supravieţuire de 35-50% la 5 ani. Tratamentul neoadjuvant cu aşa preparate
chemoterapeutice ca irinotecanul şi oxaliplatina şi preparate biologice (bevacizumab, cetuximab, panitumumab) are un rol
important în creşterea numărului de pacienţi eligibili pentru rezecţie secundară. Numărul sau dimensiunea metastazelor sau
chiar prezenţa bolii rezecabile extrahepatice nu trebuie să mai fie o contraindicaţie absolută, iar durata chimioterapiei trebuie să
fie cât mai scurtă pentru a ajunge la rezecţie imediat, ce este posibil din punct de vedere tehnic în absenţa progresului tumorii.
În această situaţie, cel puţin patru cure de chimioterapie de primă linie trebuie administrate, cu verificarea răspunsului tumorii la
fiecare 2 luni. Creşterea interesului în aşa marcheri moleculari ca KRAS şi BRAF, de asemenea va ajuta în stratificarea
populaţiei cu identificarea de pacienţi pentru terapia ţintă. În această revistă a literaturii, noi descriem strategiile oncochirurgicale
curente utilizate la pacienţii cu MHCR rezecabile şi non-rezecabile pentru a facilita atingerea rezecţiei R0 care
include embolizarea venei porte, hepatectomia pe etape şi hepatectomia prin ablaţie cu radiofrecvenţă, beneficiile acestora, cât
şi strategiile viitoare de tratament. În concluzie, participarea unei echipe multidisciplinare în tratamentul MHCR este esenţială
pentru îmbunătăţirea rezultatelor clinice şi de supravieţuire.Summary: Patients with liver metastases from colorectal cancer (CRC) present a major public health challenge with
approximately, 1.2 million cases of CRC occur yearly worldwide. Resection of colorectal liver metastases (CRLM) is the only
treatment offering the possibility of cure and has been shown to provide clear survival benefits. However, only 10 to 20% of
patients with CRLM are eligible for this procedure upfront. During the last decade, major advances in the management of CRLM
have taken place involving three fields: oncology, radiology and surgery. These advances have increased the resectability rate
to 20-30% of cases with a 5-year survival of 35-50%. Neoadjuvant treatment with chemotherapeutic agents such as irinotecan
and oxaliplatin, and biologic agents (bevacizumab, cetuximab, panitumumab) play an important role in increasing the number of
patients eligible to secondary resection. The number or size of metastases or even the presence of resectable extrahepatic
disease should not be longer an absolute contraindication, and the duration of chemotherapy should be as short as possible to
achieve the resection as soon as technically possible in the absence tumour progression. In this situation, at least four courses
of first-line chemotherapy should be given, with assessment of tumour response every 2 months. Increasing interest in
predictive molecular markers, such as KRAS and BRAF, will also help stratify patient populations to targeted therapy. In this
review, we have described the current oncosurgical strategies employed in patients with resectable and non resectable CRLM
to help achieve R0 resection including portal vein embolization, staged hepatectomies, and hepatectomies with radiofrequency
ablation, their benefits, and future treatment strategies. In conclusion, multidisciplinary team for the treatment of CRLM is
essential for improving clinical and survival outcomes
Adenocarcinoma in Caroli's Disease Treated by Liver Transplantation
Caroli's disease is characterized by congenital cystic dilatation of the intrahepatic bile ducts. In 7% of
casea a malignant tumor develops complicating the course of the disease
Homozygous R136S mutation in PRNP gene causes inherited early onset prion disease
Altres ajuts: Fundació la Marató de TV3/201821-31Background: More than 40 pathogenic heterozygous PRNP mutations causing inherited prion diseases have been identified to date. Recessive inherited prion disease has not been described to date. Methods: We describe the clinical and neuropathological data of inherited early-onset prion disease caused by the rare PRNP homozygous mutation R136S. In vitro PrP propagation studies were performed using recombinant-adapted protein misfolding cyclic amplification technique. Brain material from two R136S homozygous patients was intracranially inoculated in TgMet129 and TgVal129 transgenic mice to assess the transmissibility of this rare inherited form of prion disease. Results: The index case presented symptoms of early-onset dementia beginning at the age of 49 and died at the age of 53. Neuropathological evaluation of the proband revealed abundant multicentric PrP plaques and Western blotting revealed a ~ 8 kDa protease-resistant, unglycosylated PrP fragment, consistent with a Gerstmann-Sträussler-Scheinker phenotype. Her youngest sibling suffered from progressive cognitive decline, motor impairment, and myoclonus with onset in her late 30s and died at the age of 48. Genetic analysis revealed the presence of the R136S mutation in homozygosis in the two affected subjects linked to homozygous methionine at codon 129. One sibling carrying the heterozygous R136S mutation, linked to homozygous methionine at codon 129, is still asymptomatic at the age of 74. The inoculation of human brain homogenates from our index case and an independent case from a Portuguese family with the same mutation in transgenic mice expressing human PrP and in vitro propagation of PrP studies failed to show disease transmissibility. Conclusion: In conclusion, biallelic R136S substitution is a rare variant that produces inherited early-onset human prion disease with a Gerstmann-Sträussler-Scheinker neuropathological and molecular signature. Even if the R136S variant is predicted to be "probably damaging", heterozygous carriers are protected, at least from an early onset providing evidence for a potentially recessive pattern of inheritance in human prion diseases
Kinetic modeling of tumor growth and dissemination in the craniospinal axis: implications for craniospinal irradiation
BACKGROUND: Medulloblastoma and other types of tumors that gain access to the cerebrospinal fluid can spread throughout the craniospinal axis. The purpose of this study was to devise a simple multi-compartment kinetic model using established tumor cell growth and treatment sensitivity parameters to model the complications of this spread as well as the impact of treatment with craniospinal radiotherapy. METHODS: A two-compartment mathematical model was constructed. Rate constants were derived from previously published work and the model used to predict outcomes for various clinical scenarios. RESULTS: The model is simple and with the use of known and estimated clinical parameters is consistent with known clinical outcomes. Treatment outcomes are critically dependent upon the duration of the treatment break and the radiosensitivity of the tumor. Cross-plot analyses serve as an estimate of likelihood of cure as a function of these and other factors. CONCLUSION: The model accurately describes known clinical outcomes for patients with medulloblastoma. It can help guide treatment decisions for radiation oncologists treating patients with this disease. Incorporation of other treatment modalities, such as chemotherapy, that enhance radiation sensitivity and/or reduce tumor burden, are predicted to significantly increase the probability of cure
Bona fide atypical scrapie faithfully reproduced for the first time in a rodent model
Atypical Scrapie, which is not linked to epidemics, is assumed to be an idiopathic spontaneous prion disease in small ruminants. Therefore, its occurrence is unlikely to be controlled through selective breeding or other strategies as it is done for classical scrapie outbreaks. Its spontaneous nature and its sporadic incidence worldwide is reminiscent of the incidence of idiopathic spontaneous prion diseases in humans, which account for more than 85% of the cases in humans. Hence, developing animal models that consistently reproduce this phenomenon of spontaneous PrP misfolding, is of importance to study the pathobiology of idiopathic spontaneous prion disorders. Transgenic mice overexpressing sheep PrPC with I112 polymorphism (TgShI112, 1–2 × PrP levels compared to sheep brain) manifest clinical signs of a spongiform encephalopathy spontaneously as early as 380 days of age. The brains of these animals show the neuropathological hallmarks of prion disease and biochemical analyses of the misfolded prion protein show a ladder-like PrPres pattern with a predominant 7–10 kDa band. Brain homogenates from spontaneously diseased transgenic mice were inoculated in several models to assess their transmissibility and characterize the prion strain generated: TgShI112 (ovine I112 ARQ PrPC), Tg338 (ovine VRQ PrPC), Tg501 (ovine ARQ PrPC), Tg340 (human M129 PrPC), Tg361 (human V129 PrPC), TgVole (bank vole I109 PrPC), bank vole (I109I PrPC), and sheep (AHQ/ARR and AHQ/AHQ churra-tensina breeds). Our analysis of the results of these bioassays concludes that the strain generated in this model is indistinguishable to that causing atypical scrapie (Nor98). Thus, we present the first faithful model for a bona fide, transmissible, ovine, atypical scrapie prion disease.info:eu-repo/semantics/publishedVersio
Bona fide atypical scrapie faithfully reproduced for the first time in a rodent model
Atypical Scrapie, which is not linked to epidemics, is assumed to be an idiopathic spontaneous prion disease in small ruminants. Therefore, its occurrence is unlikely to be controlled through selective breeding or other strategies as it is done for classical scrapie outbreaks. Its spontaneous nature and its sporadic incidence worldwide is reminiscent of the incidence of idiopathic spontaneous prion diseases in humans, which account for more than 85% of the cases in humans. Hence, developing animal models that consistently reproduce this phenomenon of spontaneous PrP misfolding, is of importance to study the pathobiology of idiopathic spontaneous prion disorders. Transgenic mice overexpressing sheep PrPC with I112 polymorphism (TgShI112, 1–2 × PrP levels compared to sheep brain) manifest clinical signs of a spongiform encephalopathy spontaneously as early as 380 days of age. The brains of these animals show the neuropathological hallmarks of prion disease and biochemical analyses of the misfolded prion protein show a ladder-like PrPres pattern with a predominant 7–10 kDa band. Brain homogenates from spontaneously diseased transgenic mice were inoculated in several models to assess their transmissibility and characterize the prion strain generated: TgShI112 (ovine I112 ARQ PrPC), Tg338 (ovine VRQ PrPC), Tg501 (ovine ARQ PrPC), Tg340 (human M129 PrPC), Tg361 (human V129 PrPC), TgVole (bank vole I109 PrPC), bank vole (I109I PrPC), and sheep (AHQ/ARR and AHQ/AHQ churra-tensina breeds). Our analysis of the results of these bioassays concludes that the strain generated in this model is indistinguishable to that causing atypical scrapie (Nor98). Thus, we present the first faithful model for a bona fide, transmissible, ovine, atypical scrapie prion disease.info:eu-repo/semantics/publishedVersio
Development of a New largely scalable in vitro prion propagation method for the production of infectious recombinant prions for high resolution structural studies.
The resolution of the three-dimensional structure of infectious prions at the atomic level is pivotal to understand the pathobiology of Transmissible Spongiform Encephalopathies (TSE), but has been long hindered due to certain particularities of these proteinaceous pathogens. Difficulties related to their purification from brain homogenates of disease-affected animals were resolved almost a decade ago by the development of in vitro recombinant prion propagation systems giving rise to highly infectious recombinant prions. However, lack of knowledge about the molecular mechanisms of the misfolding event and the complexity of systems such as the Protein Misfolding Cyclic Amplification (PMCA), have limited generating the large amounts of homogeneous recombinant prion preparations required for high-resolution techniques such as solid state Nuclear Magnetic Resonance (ssNMR) imaging. Herein, we present a novel recombinant prion propagation system based on PMCA that substitutes sonication with shaking thereby allowing the production of unprecedented amounts of multi-labeled, infectious recombinant prions. The use of specific cofactors, such as dextran sulfate, limit the structural heterogeneity of the in vitro propagated prions and makes possible, for the first time, the generation of infectious and likely homogeneous samples in sufficient quantities for studies with high-resolution structural techniques as demonstrated by the preliminary ssNMR spectrum presented here. Overall, we consider that this new method named Protein Misfolding Shaking Amplification (PMSA), opens new avenues to finally elucidate the three-dimensional structure of infectious prions
Understanding the key features of the spontaneous formation of bona fde prions through a novel methodology that enables their swift and consistent generation
Among transmissible spongiform encephalopathies or prion diseases afecting humans, sporadic forms such as spo‑
radic Creutzfeldt–Jakob disease are the vast majority. Unlike genetic or acquired forms of the disease, these idiopathic
forms occur seemingly due to a random event of spontaneous misfolding of the cellular PrP (PrPC) into the patho‑
genic isoform (PrPSc). Currently, the molecular mechanisms that trigger and drive this event, which occurs
in approximately one individual per million each year, remain completely unknown. Modelling this phenomenon
in experimental settings is highly challenging due to its sporadic and rare occurrence. Previous attempts to model
spontaneous prion misfolding in vitro have not been fully successful, as the spontaneous formation of prions is infre‑
quent and stochastic, hindering the systematic study of the phenomenon. In this study, we present the frst method
that consistently induces spontaneous misfolding of recombinant PrP into bona fde prions within hours, providing
unprecedented possibilities to investigate the mechanisms underlying sporadic prionopathies. By fne‑tuning the Pro‑
tein Misfolding Shaking Amplifcation method, which was initially developed to propagate recombinant prions,
we have created a methodology that consistently produces spontaneously misfolded recombinant prions in 100%
of the cases. Furthermore, this method gives rise to distinct strains and reveals the critical infuence of charged sur‑
faces in this process.The present work was partially funded by three different grants awarded by “Ministerio de Economía y Competitividad” (Spanish Government), grant numbers PID2021-122201OB-C21, PID2021-1222010B-C22 and PID2020-117465GB-I00, funded by MCIN/AEI/10.13039/501100011033 and co-financed by the European Regional Development Fund (ERDF), and by the Instituto de Salud Carlos III (ISCIII), grant number AC21_2/00024. Additionally, CIC bioGUNE currently holds a Severo Ochoa Excellence accreditation, CEX2021-001136-S, also funded by MCIN/AEI/10.13039/501100011033. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio
Higher Postoperative Mortality and Inferior Survival After Right-Sided Liver Resection for Perihilar Cholangiocarcinoma:Left-Sided Resection is Preferred When Possible
BACKGROUND: A right- or left-sided liver resection can be considered in about half of patients with perihilar cholangiocarcinoma (pCCA), depending on tumor location and vascular involvement. This study compared postoperative mortality and long-term survival of right- versus left-sided liver resections for pCCA.METHODS: Patients who underwent major liver resection for pCCA at 25 Western centers were stratified according to the type of hepatectomy-left, extended left, right, and extended right. The primary outcomes were 90-day mortality and overall survival (OS).RESULTS: Between 2000 and 2022, 1701 patients underwent major liver resection for pCCA. The 90-day mortality was 9% after left-sided and 18% after right-sided liver resection (p < 0.001). The 90-day mortality rates were 8% (44/540) after left, 11% (29/276) after extended left, 17% (51/309) after right, and 19% (108/576) after extended right hepatectomy (p < 0.001). Median OS was 30 months (95% confidence interval [CI] 27-34) after left and 23 months (95% CI 20-25) after right liver resection (p < 0.001), and 33 months (95% CI 28-38), 27 months (95% CI 23-32), 25 months (95% CI 21-30), and 21 months (95% CI 18-24) after left, extended left, right, and extended right hepatectomy, respectively (p < 0.001). A left-sided resection was an independent favorable prognostic factor for both 90-day mortality and OS compared with right-sided resection, with similar results after excluding 90-day fatalities.CONCLUSIONS: A left or extended left hepatectomy is associated with a lower 90-day mortality and superior OS compared with an (extended) right hepatectomy for pCCA. When both a left and right liver resection are feasible, a left-sided liver resection is preferred.</p
Higher Postoperative Mortality and Inferior Survival After Right-Sided Liver Resection for Perihilar Cholangiocarcinoma:Left-Sided Resection is Preferred When Possible
BACKGROUND: A right- or left-sided liver resection can be considered in about half of patients with perihilar cholangiocarcinoma (pCCA), depending on tumor location and vascular involvement. This study compared postoperative mortality and long-term survival of right- versus left-sided liver resections for pCCA.METHODS: Patients who underwent major liver resection for pCCA at 25 Western centers were stratified according to the type of hepatectomy-left, extended left, right, and extended right. The primary outcomes were 90-day mortality and overall survival (OS).RESULTS: Between 2000 and 2022, 1701 patients underwent major liver resection for pCCA. The 90-day mortality was 9% after left-sided and 18% after right-sided liver resection (p < 0.001). The 90-day mortality rates were 8% (44/540) after left, 11% (29/276) after extended left, 17% (51/309) after right, and 19% (108/576) after extended right hepatectomy (p < 0.001). Median OS was 30 months (95% confidence interval [CI] 27-34) after left and 23 months (95% CI 20-25) after right liver resection (p < 0.001), and 33 months (95% CI 28-38), 27 months (95% CI 23-32), 25 months (95% CI 21-30), and 21 months (95% CI 18-24) after left, extended left, right, and extended right hepatectomy, respectively (p < 0.001). A left-sided resection was an independent favorable prognostic factor for both 90-day mortality and OS compared with right-sided resection, with similar results after excluding 90-day fatalities.CONCLUSIONS: A left or extended left hepatectomy is associated with a lower 90-day mortality and superior OS compared with an (extended) right hepatectomy for pCCA. When both a left and right liver resection are feasible, a left-sided liver resection is preferred.</p
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