365 research outputs found
Hepatic progenitor cells from adult human livers for cell transplantation.
Objective: Liver regeneration is mainly based on cellular
self-renewal including progenitor cells. Efforts have been
made to harness this potential for cell transplantation, but
shortage of hepatocytes and premature differentiated
progenitor cells from extra-hepatic organs are limiting
factors. Histological studies implied that resident cells in
adult liver can proliferate, have bipotential character and
may be a suitable source for cell transplantation.
Methods: Particular cell populations were isolated after
adequate tissue dissociation. Single cell suspensions were
purified by Thy-1 positivity selection, characterised in vitro
and transplanted in immunodeficient Pfp/Rag2 mice.
Results: Thy-1+ cells that are mainly found in the portal
tract and the surrounding parenchyma, were isolated from
surgical liver tissue with high yields from specimens with
histological signs of regeneration. Thy-1+ cell populations
were positive for progenitor (CD34, c-kit, CK14, M2PK,
OV6), biliary (CK19) and hepatic (HepPar1) markers
revealing their progenitor as well as hepatic and biliary
nature. The potential of Thy-1+ cells for differentiation in
vitro was demonstrated by increased mRNA and protein
expression for hepatic (CK18, HepPar1) and biliary (CK7)
markers during culture while progenitor markers CK14,
chromogranin A and nestin were reduced. After
transplantation of Thy-1+ cells into livers of immunodeficient
mice, engraftment was predominantly seen in the
periportal portion of the liver lobule. Analysis of in situ
material revealed that transplanted cells express human
hepatic markers HepPar1 and albumin, indicating functional
engraftment.
Conclusion: Bipotential progenitor cells from human
adult livers can be isolated using Thy-1 and might be a
potential candidate for cell treatment in liver diseases
Ileo-right hemi-colonic cervical pull-up on a non-supercharged ileocolic arterial pedicle: A technical and case report
Esophageal reconstruction can be challenging when stomach and colon are not anatomically intact and their use as esophageal substitutes is therefore limited. Innovative individual approaches are then necessary to restore the intestinal passage. We describe a technique in which a short stump of the right hemicolon and 25 cm of ileum on a long, non-supercharged, fully mobilized ileocolic arterial pedicle were used for esophageal reconstruction to the neck. In this case, a 65 year-old male patient had accidentally indigested hydrochloric acid which caused necrosis of his upper digestive tract. An emergency esophagectomy, gastrectomy, duodenectomy, pancreatectomy and splenectomy had been performed in an outside hospital. A cervical esophagostomy and a biliodigestive anastomosis had been created and a jejunal catheter for enteral feeding had been placed. After the patient had recovered, a reconstruction of his food passage via the left and transverse colon failed for technical reasons due to an intraoperative necrotic demarcation of the colon. Our team then faced the situation that only a short stump of the right hemi-colon was left in situ when the patient was referred to our center. After intensified nutritional therapy, we reconstructed this patient's food passage with the right hemicolon-approach described herein. After treatment of a postoperative pneumonia, the patient was discharged from hospital on the 26th postoperative day in a good clinical condition on an oral-only diet. In conclusion, individual approaches for long-segment reconstruction of the esophagus can be technically feasible in experienced hands. They do not always require arterial supercharging or free intestinal transplantation
Crohn's disease activity index and Vienna classification - Is it worthwhile to calculate before surgery?
Background: Crohn's disease (CD) patients with increased disease activity may reveal an increased risk for perioperative complications. The `Crohn's disease activity index' (CDAI) and the `Vienna classification' (VC) were developed for standardized disease activity estimations. The significance of these scores to predict extent, type and early outcome of surgery in CD patients was analyzed. Methods: In 179 surgically treated CD patients, the CDAI and VC were assessed from a prospective database. Relations of the scores with CD risk factors, type, number, location and complications of surgery were analyzed. Results: VC behavior and location subtypes were associated with distinct types of surgery (i.e. `strictureplasty' in `stricturing disease', `colon surgery' in `colon involvement'), but not with surgery type and extent or outcome. Surgery extent (i.e. with 5 vs. 3 `surgical sites' 425 +/- 25 vs. 223.3 +/- 25) and complications (357.1 +/- 36.9 (with) vs. 244.4 +/- 13 (without)) were associated with elevated CDAI levels; however, nicotine abuse remained the only significant risk factor for perioperative complications after multiple logistic regression. Conclusion: The significance of VC or CDAI for predicting the extent of surgery or complications is limited. None of the tested variables except preoperative nicotine abuse influenced the likelihood for perioperative complications. Copyright (c) 2006 S. Karger AG, Base
Search for the electric dipole excitations to the multiplet in Sn
The odd-mass Sn nucleus was investigated in nuclear resonance
fluorescence experiments up to an endpoint energy of the incident photon
spectrum of 4.1 MeV at the bremsstrahlung facility of the Stuttgart University.
More than 50 mainly hitherto unknown levels were found. From the measurement of
the scattering cross sections model independent absolute electric dipole
excitation strengths were extracted. The measured angular distributions
suggested the spins of 11 excited levels. Quasi-particle phonon model
calculations including a complete configuration space were performed for the
first time for a heavy odd-mass spherical nucleus. These calculations give a
clear insight in the fragmentation and distribution of the , , and
excitation strength in the low energy region. It is proven that the
component of the two-phonon quintuplet built on
top of the ground state is strongly fragmented. The theoretical
calculations are consistent with the experimental data.Comment: 10 pages, 5 figure
Super selective percutaneous transhepatic coil embolization of intrahepatic pseudoaneurysm after pediatric liver transplantation: a case report
Background
Intrahepatic arterial pseudoaneurysms are a rare, life-threatening complication after pediatric liver transplantation. Treatment of choice represents interventional radiological management with endovascular embolization of the segmental artery proximal and distal to the aneurysm. However, this technique results in loss of arterial perfusion distal to the aneurysm with subsegment arterial ischemia.
Case presentation
We report a case of a 1-year-old girl with a pseudoaneurysm in the split-liver graft. Direct percutaneous, transhepatic access to the pseudoaneurysm was performed followed by super selective coil application into the aneurysm.
Conclusion
Super selective percutaneous, transhepatic coil application is feasible even in pediatric patients after liver transplantation and results in preservation of the entire course of the liver artery
Predictive preoperative clinical score for patients with liver-only oligometastatic colorectal cancer
BACKGROUND: Resection of liver metastases from colorectal cancer (CRC) in the oligometastatic stage improves survival and is a potentially curative treatment. Thus, predictive scores that reliably identify those patients who especially benefit from surgery are essential. PATIENTS AND METHODS: In this multicenter analysis, 512 patients had undergone surgery for liver metastases from CRC. We investigated distinct cancer-specific risk factors that are routinely available in clinical practice and developed a predictive preoperative score using a training cohort (TC), which was thereafter tested in a validation cohort (VC). RESULTS: Inflammatory response to the tumor, a right-sided primary tumor, multiple liver metastases, and node-positive primary tumor were significant adverse variables for overall survival (OS). Patients were stratified in five groups according to the cumulative score given by the presence of these risk factors. Median OS for patients without risk factors was 133.8 months [95% confidence interval (CI) 81.2-not reached (nr)] in the TC and was not reached in the VC. OS decreased significantly for each subsequent group with increasing number of risk factors. Median OS was significantly shorter (P < 0.0001) for patients presenting all four risk factors: 14.3 months (95% CI 10.5 months-nr) in the TC and 16.6 months (95% CI 14.6 months-nr) in the VC. CONCLUSIONS: Including easily obtainable variables, this preoperative score identifies oligometastatic CRC patients with prolonged survival rates that may be cured, and harbors potential to be implemented in daily clinical practice
Safety and feasibility of third-party multipotent adult progenitor cells for immunomodulation therapy after liver transplantation--a phase I study (MISOT-I)
BACKGROUND: Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs. METHODS: Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n=3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with Basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each). DISCUSSION: If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy
Current approaches to gene regulatory network modelling
Many different approaches have been developed to model and simulate gene regulatory networks. We proposed the following categories for gene regulatory network models: network parts lists, network topology models, network control logic models, and dynamic models. Here we will describe some examples for each of these categories. We will study the topology of gene regulatory networks in yeast in more detail, comparing a direct network derived from transcription factor binding data and an indirect network derived from genome-wide expression data in mutants. Regarding the network dynamics we briefly describe discrete and continuous approaches to network modelling, then describe a hybrid model called Finite State Linear Model and demonstrate that some simple network dynamics can be simulated in this model
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