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1.
Blood ; 141(13): 1626-1639, 2023 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-36564029

RESUMEN

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the only curative treatment option for a number of hematologic malignancies. Its therapeutic potential relies on the potency of donor T cells to eliminate residual malignant cells, the so-called graft-versus-leukemia (GVL) effect. Disease relapse remains the most frequent treatment failure and is associated with poor outcome. Therefore, it is inevitable to decipher mechanisms that weaken GVL. In recent years, studies of tumor biology have revealed that metabolic remodeling of the micromilieu can critically regulate immune responses. Accumulation of reactive oxygen species leads to a metabolic condition known as oxidative stress, which can severely hamper T cells. Currently, only a few studies, mainly using preclinical models, have demonstrated the occurrence of oxidative stress after allo-SCTs. Therefore, we sought to investigate oxidative stress in a well-characterized group of patients who underwent allo-SCT and its impact on reconstituting T cells. We identified high concentrations of serum 8-hydroxydeoxyguanosine (8-OHdG) as an established biomarker for oxidative stress. 8-OHdG is one of the major products of DNA oxidation, which is normally rapidly removed. After allo-SCT, T cells accumulated oxidative DNA damage. High cellular 8-OHdG content (8-OHdGhi) was associated not only with signs of enhanced T-cell activation but also premature exhaustion. The inability of 8-OHdGhi T cells to efficiently target malignant cells or produce cytotoxic granzyme B and interferon gamma was associated with a significantly increased relapse risk and a shorter overall survival. Taken together, our novel findings could give reason to focus on bolstering DNA repair in reconstituting T cells as a means to improve GVL efficacy.


Asunto(s)
Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Humanos , Linfocitos T , Trasplante Homólogo , Enfermedad Crónica , Recurrencia , Estrés Oxidativo
2.
Leukemia ; 35(12): 3482-3496, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34021248

RESUMEN

Immunotherapies have heralded a new era in the cancer treatment. In addition to checkpoint inhibitors, agonistic antibodies against co-stimulatory immune receptors hold the potential to invoke efficient antitumor immunity. Targeting CD137 has gained momentum based on its ability to drive NK- and T-cell-based responses. CD137-engaging mAbs have already entered clinical trials for different types of tumors showing promising results. Despite the efforts to translate CD137-mediated immunotherapy into clinical practice, little remains known regarding the role of CD137 in human monocytes/macrophages.We found CD137 being expressed on monocytes of healthy controls and at even higher levels in patients with multiple myeloma or CLL. CD137HI(GH) monocytes displayed a distinct phenotypic, transcriptomic, and metabolic profile. They possessed an increased phagocytic capacity enabling superior antibody-dependent phagocytosis (ADPC) of multiple myeloma and lymphoma cells that were treated with anti-CD38 or anti-CD20 mAbs. Triggering CD137 promoted both metabolic and tumoricidal activity in an extracellular signal-regulated kinase (ERK)-dependent fashion. In addition, we observed a phenotypic, transcriptomic, and functional skewing towards a M1-like phenotype.Overall, we introduce CD137 as a positive immune checkpoint on human monocytes/macrophages, which can have therapeutic implications especially in view of synergistic effects when combining CD137 agonists with tumor-targeting antibodies.


Asunto(s)
Inmunoterapia/métodos , Macrófagos/inmunología , Monocitos/inmunología , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/inmunología , Miembro 9 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/inmunología , Anticuerpos Monoclonales/farmacología , Citotoxicidad Celular Dependiente de Anticuerpos , Células Cultivadas , Reprogramación Celular/inmunología , Humanos , Células Asesinas Naturales/inmunología , Macrófagos/metabolismo , Monocitos/metabolismo , Mieloma Múltiple/sangre , Mieloma Múltiple/metabolismo , Fagocitosis , Linfocitos T/inmunología , Miembro 9 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismo
3.
Plants (Basel) ; 9(8)2020 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-32784886

RESUMEN

Interest in using harvest aids (defoliants or crop desiccants) such as paraquat, carfentrazone-ethyl, glyphosate, and sodium chlorate (NaClO3) have become increasingly important to assure harvest efficiency, producer profit, and to maintain seed quality. However, information on the effects of harvest aids on seed nutrition (composition) (protein, oil, fatty acids, sugars, and amino acids) in soybean is very limited. The objective of this research was to investigate the influence of harvest aids on seed protein, oil, fatty acids, sugars, and amino acids in soybean. Our hypothesis was that harvest aid may influence seed nutrition, especially at R6 as at R6 the seeds may still undergo biochemical changes. Field experiments were conducted in 2012 and 2013 under Midsouth USA environmental conditions in which harvest aids were applied at R6 (seed-fill) and R7 (yellow pods) growth stages. Harvest aids applied included an untreated control, 0.28 kg ai ha-1 of paraquat, 0.28 kg ai ha-1 of paraquat, and 1.015 kg ai ha-1 of carfentrazone-ethyl (AIM); 6.72 kg ai ha-1 sodium chlorate, 1.015 kg ai ha-1 carfentrazone-ethyl; and 2.0 kg ae ha-1 glyphosate. Results showed that the application of harvest aids at either R6 or R7 resulted in the alteration of some seed composition such as protein, oil, oleic acid, fructose, and little effects on amino acids. In addition, harvest aids affected seed composition constituents differently depending on year and growth stage. This research demonstrated the possible alteration of some nutrients by harvest aids. This research helps growers and scientists to advance the understanding and management of harvest aids and investigate possible effects of harvest aids on seed nutrition.

4.
Leukemia ; 33(7): 1783-1796, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30679801

RESUMEN

Mesenchymal stem cells (MSCs) represent key contributors to tissue homeostasis and promising therapeutics for hyperinflammatory conditions including graft-versus-host disease. Their immunomodulatory effects are controlled by microenvironmental signals. The MSCs' functional response towards inflammatory cues is known as MSC-"licensing" and includes indoleamine 2,3-dioxygenase (IDO) upregulation. MSCs use tryptophan-depleting IDO to suppress T-cells. Increasing evidence suggests that several functions are (co-)determined by the cells' metabolic commitment. MSCs are capable of both, high levels of glycolysis and of oxidative phosphorylation. Although several studies have addressed alterations of the immune regulatory phenotype elicited by inflammatory priming metabolic mechanisms controlling this process remain unknown. We demonstrate that inflammatory MSC-licensing causes metabolic shifts including enhanced glycolysis and increased fatty acid oxidation. Yet, only interfering with glycolysis impacts IDO upregulation and impedes T-cell-suppressivity. We identified the Janus kinase (JAK)/signal transducer and activator of transcription (STAT)1 pathway as a regulator of both glycolysis and IDO, and show that enhanced glucose turnover is linked to abundant STAT1 glycosylation. Inhibiting the responsible O-acetylglucosamine (O-GlcNAc) transferase abolishes STAT1 activity together with IDO upregulation. Our data suggest that STAT1-O-GlcNAcylation increases its stability towards degradation thus sustaining downstream effects. This pathway could represent a target for interventions aiming to enhance the MSCs' immunoregulatory potency.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Glucólisis , Inflamación/inmunología , Células Madre Mesenquimatosas/inmunología , Factor de Transcripción STAT1/metabolismo , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/patología , Proliferación Celular , Glicosilación , Células HeLa , Humanos , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Inflamación/metabolismo , Inflamación/patología , Janus Quinasa 1/genética , Janus Quinasa 1/metabolismo , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/patología , Factor de Transcripción STAT1/genética , Transducción de Señal , Regulación hacia Arriba
7.
Leukemia ; 31(2): 470-478, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27479178

RESUMEN

Immune dysfunctions in chronic lymphocytic leukemia (CLL) contribute to tumor immune escape and attenuate immune-based therapies. Monocytes/macrophages represent key components of cancer immune surveillance and effectors for antibody-mediated antitumor effects. Monocytes display an altered subset composition in CLL. Moreover, we find a changed metabolic phenotype: glucose uptake, glucose transporters and expression of glycolytic molecules are reduced. Our data establish a link between glycolytic competence and monocyte-mediated phagocytosis of tumor cells. Furthermore, we report that CLL monocytes express Bruton's tyrosine kinase (BTK). Our observations suggest that using BTK inhibitors in CLL might further aggravate the observed immune metabolic defects in monocytes. Triggering the programmed cell death-1 (PD-1) checkpoint on monocytes hampers glycolysis, phagocytosis and BTK signaling. Conversely, disrupting PD-1/PD-L1 signaling reverses these immune metabolic dysfunctions. Taken together, our findings imply a novel metabolic interplay between CLL cells and monocytes and that blocking PD-1/PD-L1 might restore metabolic together with antitumor activity of CLL monocytes/macrophages.


Asunto(s)
Antígeno B7-H1/metabolismo , Leucemia Linfocítica Crónica de Células B/inmunología , Leucemia Linfocítica Crónica de Células B/metabolismo , Monocitos/inmunología , Monocitos/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Agammaglobulinemia Tirosina Quinasa , Biomarcadores , Metabolismo Energético/inmunología , Glucosa/metabolismo , Glucólisis/inmunología , Humanos , Monocitos/patología , Fagocitosis/inmunología , Fenotipo , Unión Proteica , Proteínas Tirosina Quinasas/metabolismo , Transducción de Señal
8.
J Dairy Sci ; 98(10): 7218-25, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26277308

RESUMEN

Whereas most soybean feedstuffs have been extensively investigated for use in ruminant diets, a lack of information exists regarding steam-flaked soybeans (SFSB). This research evaluated various inclusion rates of SFSB in diets for lactating dairy cattle. Twelve multiparous Holstein cows (103 ± 39 d in milk) were used in a 4 × 4 Latin square experiment consisting of 28-d periods, 14 d for diet transitioning followed by a 14-d sampling period. Treatments were inclusion of SFSB at 0, 5, 10, and 15% of dietary dry matter (DM), replacing a mixture of soybean meal, soy hulls, calcium salts of fatty acids, and choice white grease. Animals were fed lactating dairy cow diets formulated to be isonitrogenous and isoenergetic, containing 60% of DM as forage and 40% of DM as concentrate. Dry matter intake (mean = 28.8 kg/d), milk production (42.2 kg/d), milk fat percentage (3.52%), and feed efficiency (1.43 kg of energy-corrected milk/kg of DM intake) were similar across all treatments. Milk protein (2.98%) and lactose (4.87%) were also unaffected by the amount of SFSB in the diet. Milk urea nitrogen concentration decreased linearly as the amount of SFSB in the diet increased. Unlike some other soybean supplements, feeding SFSB did not increase trans-11 C18:1 or cis-9,trans-11 conjugated linoleic acid, but instead resulted in increased cis-9,cis-12 C18:2 and α-C18:3. Body weights (752 kg) and body condition scores (3.17) were similar with all diets. This research demonstrated that SFSB can be substituted for soybean meal and commercial fat sources while maintaining milk and milk component production and decrease milk urea nitrogen concentration.


Asunto(s)
Bovinos/fisiología , Dieta/veterinaria , Suplementos Dietéticos , Glycine max , Leche/metabolismo , Alimentación Animal/análisis , Animales , Industria Lechera , Femenino , Lactancia , Proteínas de la Leche/metabolismo , Vapor
9.
Zentralbl Chir ; 140(2): 214-8, 2015 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-25874472

RESUMEN

Extended resections of pelvic malignancies, especially in cases of recurrent malignancies, result in the formation of large tissue defects in the region of the pelvic floor and perineum, which are difficult to deal with. Both after extra levator rectal excision and pelvic exenteration, wound healing deficiencies and local infections of the perineal wound are frequent. Primary closure is often impossible due to a lack of tissue substance after resection and an additional previous radiotherapy in most cases. This can result in poor or non-healing wounds, a consecutive need of complex care and an increased risk of secondary problems including tumour recurrences. A permanent wound closure of good quality can therefore only be achieved by plastic surgery. This can be done by local or distant muscle flaps with or without skin, for example, the gluteus maximus flap, the vertical rectus abdominis muscle flap (VRAM) or free flaps such as the latissimus dorsi flap.


Asunto(s)
Recurrencia Local de Neoplasia/cirugía , Exenteración Pélvica/métodos , Neoplasias Pélvicas/cirugía , Procedimientos de Cirugía Plástica/métodos , Femenino , Humanos , Masculino , Sacro/cirugía , Colgajos Quirúrgicos/cirugía , Cicatrización de Heridas/fisiología
10.
Front Plant Sci ; 6: 31, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25741347

RESUMEN

Information on the effects of management practices on soybean seed composition is scarce. Therefore, the objective of this research was to investigate the effects of planting date (PD) and seeding rate (SR) on seed composition (protein, oil, fatty acids, and sugars) and seed minerals (B, P, and Fe) in soybean grown in two row-types (RTs) on the Mississippi Delta region of the Midsouth USA. Two field experiments were conducted in 2009 and 2010 on Sharkey clay and Beulah fine sandy loam soil at Stoneville, MS, USA, under irrigated conditions. Soybean were grown in 102 cm single-rows and 25 cm twin-rows in 102 cm centers at SRs of 20, 30, 40, and 50 seeds m(-2). The results showed that in May and June planting, protein, glucose, P, and B concentrations increased with increased SR, but at the highest SRs (40 and 50 seeds m(-2)), the concentrations remained constant or declined. Palmitic, stearic, and linoleic acid concentrations were the least responsive to SR increases. Early planting resulted in higher oil, oleic acid, sucrose, B, and P on both single and twin-rows. Late planting resulted in higher protein and linolenic acid, but lower oleic acid and oil concentrations. The changes in seed constituents could be due to changes in environmental factors (drought and temperature), and nutrient accumulation in seeds and leaves. The increase of stachyose sugar in 2010 may be due to a drier year and high temperature in 2010 compared to 2009; suggesting the possible role of stachyose as an environmental stress compound. Our research demonstrated that PD, SR, and RT altered some seed constituents, but the level of alteration in each year dependent on environmental factors such as drought and temperature. This information benefits growers and breeders for considering agronomic practices to select for soybean seed nutritional qualities under drought and high heat conditions.

11.
Plant Dis ; 99(9): 1236-1240, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30695921

RESUMEN

Corn infected with Ustilago maydis (common smut) produces galls that are valued as a delicacy in some cultures. During a 4-year period, aflatoxin levels in asymptomatic kernels of smutted ears were, on average, 45-fold higher than in kernels harvested from smut-free control ears and 99-fold higher than in smut galls. Aflatoxin levels in smut galls were lower than in kernels of smut-free control corn in all years combined. Fumonisin levels in asymptomatic kernels harvested from smutted ears were 5.2-fold higher than in kernels from smut-free control ears and 4.0-fold higher than in smut galls. Fumonisin levels in smut galls were not significantly different than in kernels of smut-free control corn. These studies indicate that, although corn smut was relatively free of the mycotoxins studied, the asymptomatic kernels of those ears contained mycotoxins at levels much higher than usually considered safe for direct human consumption.

12.
Chirurg ; 86(6): 552-60, 2015 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-25298187

RESUMEN

Liver resection has developed into the current standard procedure due to modern resection techniques, profound knowledge of the liver anatomy and optimized surgical and anesthesiological strategies to allow extended resections with both low morbidity and mortality. Initially major blood loss was the biggest concern with liver resection and a Pringle's manoeuvre was necessary. Nowadays, biliary leakage is the major problem after liver surgery. Besides the classical conventional clamp crushing technique for parenchymal transection, various devices including ultrasound, microwaves and staplers have been introduced. Minimally invasive techniques have become increasingly important for liver resection but are still applied in selected patients only. The selection of the resection technique and device mainly depends on the extent of the resection and also on the liver parenchyma, the liver disease, costs, personal experiences and preferences. This article presents a selection of techniques used in modern parenchymal transection during liver resection with special focus on transection time, blood loss, bile leakage and costs.


Asunto(s)
Fístula Biliar/prevención & control , Hepatectomía/métodos , Hepatopatías/cirugía , Complicaciones Posoperatorias/prevención & control , Hemorragia Posoperatoria/prevención & control , Fístula Biliar/etiología , Fístula Biliar/terapia , Terapia Combinada , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/terapia , Hemorragia Posoperatoria/etiología , Hemorragia Posoperatoria/terapia , Reoperación
13.
Rev Sci Instrum ; 85(11): 11D601, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25430177

RESUMEN

We present a temporally and a spatially resolved spectrometer for titanium x-ray absorption spectroscopy along 2 axial symmetric lines-of-sight. Each line-of-sight of the instrument uses an elliptical crystal to acquire both the 2p and 3p Ti absorption lines on a single, time gated channel of the instrument. The 2 axial symmetric lines-of-sight allow the 2p and 3p absorption features to be measured through the same point in space using both channels of the instrument. The spatially dependent material temperature can be inferred by observing the 2p and the 3p Ti absorption features. The data are recorded on a two strip framing camera with each strip collecting data from a single line-of-sight. The design is compatible for use at both the OMEGA laser and the National Ignition Facility. The spectrometer is intended to measure the material temperature behind a Marshak wave in a radiatively driven SiO2 foam with a Ti foam tracer. In this configuration, a broad band CsI backlighter will be used for a source and the Ti absorption spectrum measured.

14.
J Agric Food Chem ; 61(48): 11759-70, 2013 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-23750911

RESUMEN

Mycotoxin contamination levels in maize kernels are controlled by a complex set of factors including insect pressure, fungal inoculum potential, and environmental conditions that are difficult to predict. Methods are becoming available to control mycotoxin-producing fungi in preharvest crops, including Bt expression, biocontrol, and host plant resistance. Initial reports in the United States and other countries have associated Bt expression with reduced fumonisin, deoxynivalenol, and zearalenone contamination and, to a lesser extent, reduced aflatoxin contamination in harvested maize kernels. However, subsequent field results have been inconsistent, confirming that fumonisin contamination can be reduced by Bt expression, but the effect on aflatoxin is, at present, inconclusive. New maize hybrids have been introduced with increased spectra of insect control and higher levels of Bt expression that may provide important tools for mycotoxin reduction and increased yield due to reduced insect feeding, particularly if used together with biocontrol and host plant resistance.


Asunto(s)
Proteínas Bacterianas/genética , Endotoxinas/genética , Contaminación de Alimentos/análisis , Proteínas Hemolisinas/genética , Micotoxinas/análisis , Plantas Modificadas Genéticamente/química , Zea mays/química , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/metabolismo , Endotoxinas/metabolismo , Inocuidad de los Alimentos , Proteínas Hemolisinas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/microbiología , Estados Unidos , Zea mays/genética , Zea mays/metabolismo , Zea mays/microbiología
15.
Chemosphere ; 83(4): 593-8, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21190714

RESUMEN

Aminomethylphosphonic acid (AMPA) is formed in glyphosate-treated glyphosate-resistant (GR) and glyphosate-sensitive (GS) soybean [Glycine max (L.) Merr.] plants and is known to cause yellowing in soybean. Although, AMPA is less phytotoxic than glyphosate, its mode of action is different from that of glyphosate and is still unknown. Greenhouse studies were conducted at Stoneville, MS to determine the effects of AMPA on plant growth, chlorophyll content, photosynthesis, nodulation, nitrogenase activity, nitrate reductase activity, and shoot nitrogen content in GR and GS soybeans. AMPA was applied to one- to two-trifoliolate leaf stage soybeans at 0.1 and 1.0 kg ha(-1), representing a scenario of 10% and 100% degradation of glyphosate (1.0 kg ae ha(-1) use rate) to AMPA, respectively. Overall, AMPA effects were more pronounced at 1.0 kg ha(-1) than at 0.1 kg ha(-1) rate. Visual plant injury (18-27%) was observed on young leaves within 3d after treatment (DAT) with AMPA at the higher rate regardless of soybean type. AMPA injury peaked to 46-49% at 14 DAT and decreased to 17-18% by 28 DAT, in both soybean types. AMPA reduced the chlorophyll content by 37%, 48%, 66%, and 23% in GR soybean, and 17%, 48%, 57%, and 22% in GS soybean at 3, 7, 14, and 28 DAT, respectively. AMPA reduced the photosynthesis rate by 65%, 85%, and 77% in GR soybean and 59%, 88%, and 69% in GS soybean at 3, 7, and 14 DAT, respectively, compared to non-treated plants. Similarly, AMPA reduced stomatal conductance to water vapor and transpiration rates at 3, 7, and 14 DAT compared to non-treated plants in both soybean types. Photosynthesis rate, stomatal conductance, and transpiration rate recovered to the levels of non-treated plants by 28 DAT. Plant height and shoot dry weight at 28 DAT; nodulation, nitrogenase activity at 10 DAT, and nitrate reductase activity at 3 and 14 DAT were unaffected by AMPA. AMPA reduced root respiration and shoot nitrogen content at 10 DAT. These results suggest that a foliar application of AMPA could indirectly reduce photosynthesis through decreased chlorophyll content in GR and GS soybean up to 14 DAT, but affected plants can recover to normal growth by 28 DAT.


Asunto(s)
Glycine max/efectos de los fármacos , Glicina/análogos & derivados , Herbicidas/toxicidad , Organofosfonatos/toxicidad , Clorofila/metabolismo , Resistencia a Medicamentos/genética , Glicina/toxicidad , Isoxazoles , Fotosíntesis/efectos de los fármacos , Plantas Modificadas Genéticamente , Glycine max/genética , Glycine max/fisiología , Tetrazoles , Glifosato
16.
J Cell Mol Med ; 14(1-2): 267-74, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18505475

RESUMEN

The use of foetal liver cells (FLC) in the context of hepatic tissue engineering might permit efficient in vitro expansion and cryopreservation in a cell bank. A prerequisite for successful application of bioartificial liver tissue is sufficient initial vascularization. In this study, we evaluated the transplantation of fibrin gel-immobilized FLC in a vascularized arterio-veno-venous (AV)-loop model. FLC were isolated from embryonic/foetal (ED 16) rat livers and were enriched by using magnetic cell sorting (MACS). After cryopreservation, FLC were labelled by pkh-26. Cells were transplanted in a fibrin matrix into a subcutaneous chamber containing a microsurgically created AV-loop in the femoral region of the recipient rat. The chambers were explanted after 14 days. Subcutaneous implants without an AV-loop and cell-free implants served as controls. Fluorescence microscopy of the constructs was used to identify pkh-26(+)- donor cells. Characterization was performed by RT-PCR and immunhistology (IH) for CK-18 and CD31. Transplantation of FLC using the AV-loop permitted a neo-tissue formation in the fibrin matrix. A high-density vascularization was observed in the AV-loop constructs as shown by CD31 IH. Viable foetal donor cells were detected which expressed CK-18. FLC can be successfully used for heterotopic transplantation. Fibrin matrix permits rapid blood vessel ingrowth from the AV-loop and supports engraftment of FLC. It is therefore an appropriate environment for hepatocyte transplantation in combination with microsurgical vascularization strategies. Transplantation of fibrin gel-immobilized FLC may be a promising approach for the development of highly vascularized in vivo tissue-engineering-based liver support systems.


Asunto(s)
Técnicas de Cultivo de Célula , Feto/citología , Hepatocitos/trasplante , Animales , Diferenciación Celular , Femenino , Fibrina/metabolismo , Hepatocitos/citología , Hepatocitos/fisiología , Humanos , Separación Inmunomagnética , Hígado Artificial , Embarazo , Ratas , Ratas Endogámicas Lew , Ingeniería de Tejidos/métodos , Andamios del Tejido/química
17.
Chirurg ; 80(10): 915-22, 2009 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-19711022

RESUMEN

Liver resection as an emergency procedure in patients with liver injury due to abdominal trauma has become a rare procedure. In most cases liver trauma can be managed conservatively. Currently surgery is only indicated in hemodynamically instable patients and in cases of progredient haematoma where the main aim is control of bleeding. Anatomical liver resection should be avoided and may only be performed in cases of total vascular avulsion. Debridement of devascularized tissue can also be carried out in terms of an atypical liver resection. This article elucidates the current indications for liver resection after traumatic liver injury.


Asunto(s)
Traumatismos Abdominales/cirugía , Traumatismos Abdominales/terapia , Hepatopatías/cirugía , Traumatismos Abdominales/clasificación , Traumatismos Abdominales/diagnóstico por imagen , Medios de Contraste , Hematoma/cirugía , Humanos , Circulación Hepática , Radiografía
18.
J Agric Food Chem ; 56(16): 7578-85, 2008 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-18642924

RESUMEN

Mycotoxin and Aspergillus flavus levels in soil-surface corn debris left by no-till agriculture methods (stover, cobs, and cobs with grain) were determined during the December-March fallow period for near-isogenic Bt and non-Bt hybrid corn. By December, average mycotoxin levels in non-Bt corn were many times higher in cobs with grain than in grain harvested in September (total aflatoxins, 774 vs 211 ng/g; total fumonisins, 216 vs 3.5 microg/g; cyclopiazonic acid, 4102 vs 72.2 microg/g; zearalenone, 0.2 vs < 0.1 microg/g). No trichothecenes were detected. Levels of mycotoxins and A. flavus propagules were approximately 10- to 50-fold lower in cobs without grain and stover, respectively, for all mycotoxins except zearalenone. Mycotoxin levels in corn debris fractions decreased during winter but began to rise in March. Levels of all mycotoxins and A. flavus propagules were lower in harvested grain and debris from Bt than non-Bt corn, but differences were significant (p < 0.05) only for aflatoxins.


Asunto(s)
Agricultura/métodos , Aspergillus flavus , Micotoxinas/análisis , Plantas Modificadas Genéticamente/microbiología , Zea mays/microbiología , Aflatoxinas/análisis , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas/genética , Endotoxinas/genética , Fumonisinas/análisis , Expresión Génica , Proteínas Hemolisinas/genética , Mississippi , Plantas Modificadas Genéticamente/química , Estaciones del Año , Semillas/química , Semillas/microbiología , Factores de Tiempo , Zea mays/química , Zea mays/genética
19.
Transplant Proc ; 37(1): 276-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15808618

RESUMEN

The origin of liver cells from distinct bone marrow stem cells, eg, hematopoietic stem cells or multipotent adult progenitor cells has been recently described using in vitro studies. Cell culture experiments revealed the key role of growth factors and the organ-specific environment for the induction of liver-specific genes. We investigated the in vitro potential of rat mesenchymal stem cells to differentiate into hepatocytic cells in cocultures with isolated rat liver cells. Rat mesenchymal stem cells (MSCs) propagated in culture, and transduced with green fluorescent protein (GFP) were cloned. Cells from selected clones were either cultured under liver-stimulating conditions, using serum free medium supplemented with HGF, EGF, SCF, and FGF-4 alone on fibronectin-coated surfaces, or cocultured with freshly isolated rat liver cells. Cocultured cells were harvested after two weeks and sorted into GFP-positive (GFP+) and GFP-negative (GFP-) cells. RT-PCR for liver specific markers CK-18 and albumin were performed on the different cell populations. After 2 weeks, the specified culture conditions led to the expression of albumin and CK-18 RNA in GFP-positive sorted MSCs from the cocultures, whereas MSCs cultured without liver cells did not express the studied genes. The results indicate, that when cocultured with liver cells MSCs from the bone marrow have the potential to differentiate toward hepatocytic cells in vitro. We conclude that MSC may possess an enhanced capacity to differentiate into functional liver cells. Additionally, environmental factors seem to be crucial for specific and directed differentiation.


Asunto(s)
Hepatocitos/fisiología , Hígado/citología , Mesodermo/citología , Células Madre/citología , Animales , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cocultivo , Factor de Crecimiento Epidérmico/farmacología , Factores de Crecimiento de Fibroblastos/farmacología , Genes Reporteros , Proteínas Fluorescentes Verdes/análisis , Proteínas Fluorescentes Verdes/genética , Factor de Crecimiento de Hepatocito/farmacología , Hepatocitos/citología , Hígado/efectos de los fármacos , Hígado/fisiología , Ratas , Factor de Células Madre/farmacología , Células Madre/fisiología
20.
Eur Heart J ; 23(17): 1394-401, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12191751

RESUMEN

INTRODUCTION: Numerous reports on the inducibility of ventricular tachyarrhythmias (VT) in patients with atypical right bundle branch block and right precordial ST-elevation (Brugada syndrome) are based on multicentre studies that have used different stimulation protocols. Therefore, we prospectively investigated the inducibility of VT in these patients using a uniform protocol. METHODS: In 41 consecutive patients (29 males) showing a pattern of right bundle branch block and ST-elevation, programmed ventricular stimulation was performed in the right ventricular apex with up to three premature stimuli at sinus rhythm and at four different paced cycle lengths (500, 430, 370, and 330 ms) until refractoriness was reached or reproducible induction of a sustained (>30s) VT occurred. If a VT was not reproducibly inducible, the same protocol was repeated in the right ventricular outflow tract. RESULTS: A history of life-threatening events defined as syncope (n=17) or aborted sudden cardiac death (n=13) was present in 30 patients (73%); 11 individuals were asymptomatic. Inducibility (68%) was similar between symptomatic (n=21, 70%) and asymptomatic patients (n=7, 64%). In 16 (39%) patients, VT were reproducibly inducible. If patients were only stimulated in the right ventricular apex, inducibility rate decreased to 39%. If only two premature beats at two sites were used it was as low as 32%. The mean coupling intervals of the second and third premature stimuli inducing sustained VT were short: 189+/-21 ms vs 186+/-22 ms, respectively. Forty-four percent of all patients (i.e. 64% of the inducible patients) had inducible VT only with coupling intervals shorter than 200 ms. CONCLUSIONS: The stimulation protocol markedly influences the extent of inducibility of VT in patients with right bundle branch block and ST-segment elevation. These findings question the significance of previous multicentre studies using different stimulation protocols and should have implications for further studies.


Asunto(s)
Bloqueo de Rama/fisiopatología , Taquicardia Ventricular/fisiopatología , Adulto , Anciano , Desfibriladores Implantables , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Síndrome , Fibrilación Ventricular/fisiopatología
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