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1.
Internist (Berl) ; 58(8): 855-858, 2017 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-28405696

RESUMEN

A 35-year-old woman who had previously undergone a lung transplantation presented with severe abdominal pain and vomiting. The gastroscopy showed diffuse ulcerative gastric lesions. Tests for varicella zoster virus and Epstein-Barr virus via polymerase chain reactions (PCR) on endoscopically obtained gastric biopsies were found to be positive and confirmed varicella gastritis. Intravenous antiviral therapy with acyclovir was administered resulting in a normalization of all clinical symptoms, especially of abdominal pain and inflammation parameters.


Asunto(s)
Varicela/diagnóstico , Gastritis/diagnóstico , Granulomatosis con Poliangitis/cirugía , Trasplante de Pulmón , Aciclovir/uso terapéutico , Adulto , Antivirales/uso terapéutico , Varicela/complicaciones , Varicela/tratamiento farmacológico , Femenino , Gastritis/tratamiento farmacológico , Gastritis/virología , Herpesvirus Humano 3 , Humanos , Huésped Inmunocomprometido
2.
J Viral Hepat ; 21(5): 333-40, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24716636

RESUMEN

Since 2011, telaprevir (TVR)-based triple therapy is the new treatment standard for hepatitis C genotype 1 virus infection. The aim of our retrospective interim analysis encompassing the first 24 weeks on TVR-based triple therapy was to assess 'real-life' antiviral efficacy and side effects in a large single-centre cohort, both in comparison with the data obtained in large prospective clinical trials. In total, we treated 102 patients: 24 treatment-naïve patients, 58 patients pretreated with PEG-IFN/RBV (thereof: 28 with nonresponse, 25 with relapse, five unknown) and 20 patients who previously had received nonpegylated interferon. 74 of 102 patients were assigned with HCV genotype 1b; 34 of 102 patients were treated in the context of liver cirrhosis. 72 of 102 patients have reached treatment week 24 (mean treatment duration 31 weeks). In the ITT analysis, overall response rates were at: week 4: 66%; week 12: 85%; and week 24: 78%. So far, 24 patients discontinued treatment prematurely, of those, 10 patients were due to virological failure. Haematological side effects were frequent (40% anaemia), as were 'flu-like' symptoms (94%), rash (65%) and pruritus (79%). According to our interim ITT analysis encompassing up to 24 weeks of TVR-based triple therapy, our 'real-life' antiviral effects are comparable to the results of large multicentric clinical trials. However, TVR-based triple therapy exhibited a high frequency of side effects requiring multiple therapeutic interventions. Notably, in our 'real-life' cohort, no lethal case was observed so far.


Asunto(s)
Antivirales/efectos adversos , Antivirales/uso terapéutico , Hepacivirus/aislamiento & purificación , Oligopéptidos/efectos adversos , Oligopéptidos/uso terapéutico , Carga Viral , Adulto , Anciano , Estudios de Cohortes , Quimioterapia Combinada/efectos adversos , Quimioterapia Combinada/métodos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Femenino , Genotipo , Hepacivirus/clasificación , Hepacivirus/genética , Humanos , Interferones/efectos adversos , Interferones/uso terapéutico , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Ribavirina/efectos adversos , Ribavirina/uso terapéutico , Resultado del Tratamiento , Adulto Joven
3.
Z Gastroenterol ; 52(1): 27-34, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24420796

RESUMEN

Recurrent HCV infection post-liver transplantation (post-LT) is still a major challenge in the treatment of hepatitis C virus (HCV) infection. In this retrospective analysis we gathered data about treatment response and safety of all 14 post-LT patients who were treated between 2011 and 2013 at our centre with a telaprevir (TVR)-based triple therapy. Seven out of 14 patients completed the full treatment course of 48 weeks. Five patients achieved a SVR 24, while 3 additional HCV RNA-negative patients are still in follow-up (end of treatment, SVR 12 and 22). Four patients discontinued treatment prematurely due to side effects. A virological non-response at TW 4 was seen in 1 patient. Virological breakthrough was observed in 2 patients at TW 16 and 28, respectively; 1 patient displayed a virological relapse after the end of treatment (EOT). Patients with a complicated course post-LT accumulated most of the severe side effects, largely infections. One patient with cholestatic hepatitis died 11 weeks after discontinuation of treatment due to progressive graft failure. In conclusion, TVR-based triple therapy in post-LT patients reveals an acceptable antiviral efficacy. Unfortunately, severe side effects are frequent and often require therapeutic interventions. Therefore, with the approval of less straining DAA like sofosbuvir in sight, TVR-based triple therapy in post-LT patients should be, if possible avoided.


Asunto(s)
Hepatitis C/etiología , Hepatitis C/prevención & control , Trasplante de Hígado/efectos adversos , Oligopéptidos/administración & dosificación , Anciano , Antivirales/uso terapéutico , Quimioterapia Combinada , Femenino , Hepatitis C/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Prevención Secundaria , Resultado del Tratamiento
4.
Gene Ther ; 20(11): 1033-41, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23719065

RESUMEN

Due to late diagnosis and a pronounced chemoresistance, most patients with hepatocellular carcinoma (HCC) have an overall poor prognosis. Measles vaccine viruses (MeV) have been shown to possess anti-tumor properties and their efficacy has been enhanced by arming with suicide genes. To test armed MeV for the treatment of HCC, we equipped it with the suicide gene Super-cytosine deaminase (SCD) and tested the efficacy in cell culture and in a mouse xenograft model of human HCC. Prodrug conversion was investigated in cell culture and quantified by high-performance liquid chromatography. We observed a strong oncolytic activity of MeV-SCD against human HCC in vitro and in vivo. The prodrug was efficiently converted in infected cells leading to a significant enhancement of the cytotoxic effect. Treatment of HCC xenografts with MeV caused long-term virus replication in tumor tissue. We show that the suicide gene therapy induces an apoptosis-like cell death but is not dependent on intact apoptosis pathways. These results demonstrate that MeV-based suicide gene therapy is a promising novel therapy regimen for HCC overcoming resistance towards conventional therapy. The independence from apoptosis raises hopes for the treatment of patients whose tumor cells exert defects in this cell death mechanism.


Asunto(s)
Apoptosis , Carcinoma Hepatocelular/terapia , Citosina Desaminasa/genética , Virus del Sarampión , Viroterapia Oncolítica , Animales , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Chlorocebus aethiops , Cromatografía Liquida , Terapia Combinada , Citosina Desaminasa/metabolismo , Resistencia a Antineoplásicos , Genes Transgénicos Suicidas , Terapia Genética , Células Hep G2 , Humanos , Neoplasias Hepáticas Experimentales/patología , Neoplasias Hepáticas Experimentales/terapia , Vacuna Antisarampión , Virus del Sarampión/genética , Ratones , Ratones Desnudos , Virus Oncolíticos/genética , Células Tumorales Cultivadas , Células Vero , Replicación Viral , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Gynecol Oncol ; 130(2): 362-8, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23676551

RESUMEN

OBJECTIVE: To preclinical assess the feasibility of combining oncolytic measles vaccine virus (MeV) with suicide gene therapy for ovarian cancer treatment. METHODS: We genetically engineered a recombinant MeV armed with a yeast-derived bifunctional suicide gene that encodes for cytosine deaminase and uracil phosphoribosyltransferase (MeV-SCD). From this suicide gene, a chimeric protein is produced that converts the non-toxic prodrug 5-fluorocytosine (5-FC) into highly cytotoxic 5-fluorouracil (5-FU) and directly into 5-fluorouridine monophosphate (5-FUMP) thereby bypassing an important mechanism of chemoresistance to 5-FU. RESULTS: MeV-SCD was demonstrated to infect, replicate in and effectively lyse not only human ovarian cancer cell lines, but also primary tumor cells (albeit at lower efficiencies) that were derived from malignant ascites of ovarian cancer patients. Addition of the prodrug 5-FC significantly enhanced cell killing. Importantly, precision-cut tumor slices of human ovarian cancer patient specimens were efficiently infected with MeV-SCD. The prodrug-converting enzyme SCD was expressed by all infected tumor slices, thereby ensuring provision of the suicide gene arming function in patient-derived materials. CONCLUSIONS: With respect to safety and therapeutic impact, arming of oncolytic measles vaccine virus warrants further clinical investigation for ovarian cancer treatment.


Asunto(s)
Citosina Desaminasa/genética , Terapia Genética , Virus del Sarampión/genética , Viroterapia Oncolítica/métodos , Neoplasias Ováricas/terapia , Pentosiltransferasa/genética , Línea Celular Tumoral , Femenino , Flucitosina/farmacología , Humanos , Vacuna Antisarampión , Saccharomyces cerevisiae/enzimología
6.
ESMO Open ; 8(2): 100884, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36863095

RESUMEN

BACKGROUND: Talimogene laherparepvec (T-VEC), a first-in-class oncolytic viral immunotherapy, enhances tumor-specific immune activation. T-VEC combined with atezolizumab, which blocks inhibitor T-cell checkpoints, could provide greater benefit than either agent alone. Safety/efficacy of the combination was explored in patients with triple negative breast cancer (TNBC) or colorectal cancer (CRC) with liver metastases. METHODS: In this phase Ib, multicenter, open-label, parallel cohort study of adults with TNBC or CRC with liver metastases, T-VEC (106 then 108 PFU/ml; ≤4 ml) was administered into hepatic lesions via image-guided injection every 21 (±3) days. Atezolizumab 1200 mg was given on day 1 and every 21 (±3) days thereafter. Treatment continued until patients experienced dose-limiting toxicity (DLT), had complete response, progressive disease, needed alternative anticancer treatment, or withdrew due to an adverse event (AE). The primary endpoint was DLT incidence, and secondary endpoints included efficacy and AEs. RESULTS: Between 19 March 2018 and 6 November 2020, 11 patients with TNBC were enrolled (safety analysis set: n = 10); between 19 March 2018 and 16 October 2019, 25 patients with CRC were enrolled (safety analysis set: n = 24). For the 5 patients in the TNBC DLT analysis set, no patient had DLT; for the 18 patients in the CRC DLT analysis set, 3 (17%) had DLT, all serious AEs. AEs were reported by 9 (90%) TNBC and 23 (96%) CRC patients, the majority with grade ≥3 [TNBC, 7 (70%); CRC, 13 (54%)], and 1 was fatal [CRC, 1 (4%)]. Evidence of efficacy was limited. Overall response rate was 10% (95% confidence interval 0.3-44.5) for TNBC; one (10%) patient had a partial response. For CRC, no patients had a response; 14 (58%) were unassessable. CONCLUSIONS: The safety profile reflected known risks with T-VEC including risks of intrahepatic injection; no unexpected safety findings from addition of atezolizumab to T-VEC were observed. Limited evidence of antitumor activity was observed.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Hepáticas , Melanoma , Viroterapia Oncolítica , Neoplasias de la Mama Triple Negativas , Adulto , Humanos , Melanoma/terapia , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/etiología , Estudios de Cohortes , Viroterapia Oncolítica/efectos adversos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Colorrectales/terapia
7.
Gene Ther ; 18(3): 225-31, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20811468

RESUMEN

The misuse of somatic gene therapy for the purpose of enhancing athletic performance is perceived as a coming threat to the world of sports and categorized as 'gene doping'. This article describes a direct detection approach for gene doping that gives a clear yes-or-no answer based on the presence or absence of transgenic DNA in peripheral blood samples. By exploiting a priming strategy to specifically amplify intronless DNA sequences, we developed PCR protocols allowing the detection of very small amounts of transgenic DNA in genomic DNA samples to screen for six prime candidate genes. Our detection strategy was verified in a mouse model, giving positive signals from minute amounts (20 µl) of blood samples for up to 56 days following intramuscular adeno-associated virus-mediated gene transfer, one of the most likely candidate vector systems to be misused for gene doping. To make our detection strategy amenable for routine testing, we implemented a robust sample preparation and processing protocol that allows cost-efficient analysis of small human blood volumes (200 µl) with high specificity and reproducibility. The practicability and reliability of our detection strategy was validated by a screening approach including 327 blood samples taken from professional and recreational athletes under field conditions.


Asunto(s)
Rendimiento Atlético , Doping en los Deportes/métodos , Doping en los Deportes/prevención & control , Terapia Genética/métodos , Transgenes/genética , Animales , Dependovirus/genética , Componentes del Gen , Humanos , Ratones , Técnicas de Amplificación de Ácido Nucleico , Reacción en Cadena de la Polimerasa/métodos , Factor A de Crecimiento Endotelial Vascular/genética
8.
Mucosal Immunol ; 9(2): 444-57, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26307665

RESUMEN

Foxp3 (forkhead box P3 transcription factor)-expressing regulatory T cells (Tregs) are essential for immunological tolerance, best illustrated by uncontrolled effector T-cell responses and autoimmunity upon loss of Foxp3 expression. Tregs can adopt specific effector phenotypes upon activation, reflecting the diversity of functional demands in the different tissues of the body. Here, we report that Foxp3(+)CD4(+) T cells coexpressing retinoic acid-related orphan receptor-γt (RORγt), the master transcription factor for T helper type 17 (Th17) cells, represent a stable effector Treg lineage. Transcriptomic and epigenetic profiling revealed that Foxp3(+)RORγt(+) T cells display signatures of both Tregs and Th17 cells, although the degree of similarity was higher to Foxp3(+)RORγt(-) Tregs than to Foxp3(-)RORγt(+) T cells. Importantly, Foxp3(+)RORγt(+) T cells were significantly demethylated at Treg-specific epigenetic signature genes such as Foxp3, Ctla-4, Gitr, Eos, and Helios, suggesting that these cells have a stable regulatory rather than inflammatory function. Indeed, adoptive transfer of Foxp3(+)RORγt(+) T cells in the T-cell transfer colitis model confirmed their Treg function and lineage stability in vivo, and revealed an enhanced suppressive capacity as compared with Foxp3(+)RORγt(-) Tregs. Thus, our data suggest that RORγt expression in Tregs contributes to an optimal suppressive capacity during gut-specific immune responses, rendering Foxp3(+)RORγt(+) T cells as an important effector Treg subset in the intestinal system.


Asunto(s)
Colitis/inmunología , Factores de Transcripción Forkhead/inmunología , Inmunidad Mucosa/efectos de los fármacos , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/inmunología , Linfocitos T Reguladores/inmunología , Traslado Adoptivo , Animales , Antígeno CTLA-4/genética , Antígeno CTLA-4/inmunología , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Linaje de la Célula , Colitis/genética , Colitis/patología , Colon/inmunología , Colon/patología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/inmunología , Epigénesis Genética/inmunología , Femenino , Factores de Transcripción Forkhead/genética , Proteína Relacionada con TNFR Inducida por Glucocorticoide/genética , Proteína Relacionada con TNFR Inducida por Glucocorticoide/inmunología , Inflamación , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/inmunología , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Transducción de Señal , Linfocitos T Reguladores/patología , Linfocitos T Reguladores/trasplante , Factores de Transcripción/genética , Factores de Transcripción/inmunología
9.
Oncogene ; 8(12): 3359-67, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8247538

RESUMEN

In two recently reported cases, integrated hepatitis B virus (HBV) DNAs cloned from hepatocellular carcinoma were found to express a transcriptional transactivator from 3'-terminally truncated HBV surface (preS/S) genes. In this study, we characterized the transactivator at the protein level. Expression of a 3'-truncated preS2/S gene in Spodoptera frugiperda (Sf9) insect cells resulted in a C-terminally truncated middle surface protein of 76 amino acids (MHBst76), which was found to be associated with membranes of the endoplasmic reticulum and retained from Golgi processing and secretion. Accordingly, the microsome fraction of MHBst76-expressing Sf9 cells displayed transactivator activity after electric field-mediated transfer into Chang liver cells. In contrast to full-length MHBs, MHBst76 is unglycosylated, and glycosylation is not required for transactivation as shown by mutation of the glycosylation site at asparagine-4. Since highly purified MHBst76 derived from an E. coli expression system also showed transactivator activity, it is concluded that unglycosylated MHBst76 protein is the authentic transactivating factor. As the transactivator protein derives from inactive MHbs by rearrangements of integrated HBV DNA, it may be important for HBV-associated liver carcinogenesis.


Asunto(s)
Aminoácidos/análisis , Retículo Endoplásmico/química , Virus de la Hepatitis B/metabolismo , Glicoproteínas de Membrana/análisis , Animales , Asparagina/metabolismo , Línea Celular , ADN Viral/genética , Retículo Endoplásmico/fisiología , Retículo Endoplásmico/ultraestructura , Escherichia coli , Técnica del Anticuerpo Fluorescente , Reordenamiento Génico , Glicosilación , Aparato de Golgi/metabolismo , Aparato de Golgi/ultraestructura , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/fisiología , Microsomas Hepáticos/química , Microsomas Hepáticos/metabolismo , Microsomas Hepáticos/ultraestructura , Mariposas Nocturnas , Activación Transcripcional/fisiología
10.
Oncogene ; 12(8): 1597-608, 1996 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-8622879

RESUMEN

The hepatoma-derived hepatitis B virus (HBV) DNA insert HU-a has recently been shown to contain two viral transactivator genes, X and preS2 /S. We report here that HU-a induces malignant transformation after stable transfection of the fetal mouse hepatocyte line FMH202, as indicated by soft agar growth and nude mouse tumorigenicity. Transfections with HU-a subclones, containing the X gene of the preS2 /S gene alone or sequences without transactivator gene, respectively, suggested that the X gene is essential for transformation. Sequential stages of transformation and tumor progression were analysed by injection of the stably transfected FMH202 lines into nude mice, explanation of the resulting tumors and re-establishment of cell lines from the tumors. Comparison of two HU-a-transformed cell lines by HBV mRNA hybridization, Southern analysis and chromosomal in situ hybridization revealed that integrated HBV DNAs were involved in major chromosomal rearrangements in both cases. Interestingly, recombination of the HBV Dna insert during the nude mouse passage had completely abolished HBV-specific transcription in one case, indicating that expression of integrated HBV genes, while presumably involved in early transformation, is dispensable at later stages of tumor progression. The sequential transformation observed in this experimental system suggests that expression of the X gene by integrated viral DNA and subsequent hepatocyte genome mutations might both contribute to HBV-associated liver carcinogenesis.


Asunto(s)
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/virología , Transformación Celular Neoplásica , ADN Viral , Productos del Gen tax/genética , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Neoplasias Hepáticas/genética , Precursores de Proteínas/genética , Animales , Pruebas de Carcinogenicidad , Carcinoma Hepatocelular/patología , Aberraciones Cromosómicas , Elementos Transponibles de ADN , Regulación Viral de la Expresión Génica , Neoplasias Hepáticas/embriología , Neoplasias Hepáticas/virología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Oncogenes , Fenotipo , Transcripción Genética , Transfección , Células Tumorales Cultivadas
11.
Cancer Gene Ther ; 7(3): 430-7, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10766349

RESUMEN

The dramatic expansion of clinical gene therapy trials requires the development of noninvasive clinical monitoring procedures, which provide information about expression levels, expression kinetics, and spatial distribution of transduced therapeutic genes. With the development of such procedures, invasive sampling of tissue probes from patients potentially could be reduced significantly. In this study, an experimental platform for the rational design and in vitro testing of suitable receptor-ligand couples as components of future transduction tag systems for noninvasive gene therapy monitoring applications was developed. Initially, the feasibility of the delta LNGFR/nerve growth factor (NGF) transduction tag system was investigated; this system employs a mutated version of the low-affinity nerve growth factor receptor (p75mut or delta LNGFR) lacking the entire cytoplasmic domain. Specific binding of 125I-radiolabeled NGF was demonstrated for two stable delta LNGFR-transduced cell lines, but not for delta LNGFR-negative parental control cell lines. An additional binding analysis performed in a MicroImager directly confirmed binding of radiolabeled ligands (125I-NGF, 125I-anti-p75 monoclonal antibody) to the p75mut expressed on intact target cells, but not on control cells. Subsequent binding studies employing NGF radiolabeled with the positron-emitting isotope 124I demonstrated a specific binding for LNGFR+ PC12 cells. Consequently, the first in vitro proof of a transduction tag approach based on the specificity of the 124I-NGF/LNGFR interaction was provided, which opens up the possibility for future noninvasive positron emission tomography monitoring in clinical gene therapy trials.


Asunto(s)
Terapia Genética/métodos , Factor de Crecimiento Nervioso/genética , Receptor de Factor de Crecimiento Nervioso/genética , Retroviridae/genética , Transducción Genética , Células 3T3 , Animales , Anticuerpos Monoclonales/metabolismo , Sitios de Unión de Anticuerpos , Línea Celular , Regulación Neoplásica de la Expresión Génica , Marcadores Genéticos , Radioisótopos de Yodo/metabolismo , Ratones , Factor de Crecimiento Nervioso/biosíntesis , Células PC12 , Ratas , Receptor de Factor de Crecimiento Nervioso/biosíntesis , Receptor de Factor de Crecimiento Nervioso/inmunología , Eliminación de Secuencia/genética , Tomografía Computarizada de Emisión/métodos
12.
Arch Virol Suppl ; 4: 63-4, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1450727

RESUMEN

We have studied the c-myc gene as a possible target of HBV X protein in liver carcinogenesis. Our results indicate that trans-activation by X protein occurs via PKC/AP1 signal transduction, suggesting a possible two-step mechanism in HBV related liver carcinogenesis.


Asunto(s)
Virus de la Hepatitis B/genética , Transducción de Señal , Transactivadores/genética , Activación Transcripcional , Células Cultivadas , Genes myc/genética , Humanos , Neoplasias Hepáticas/etiología , Proteína Quinasa C/metabolismo , Proteínas Reguladoras y Accesorias Virales
13.
Phytopathology ; 89(9): 805-10, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18944709

RESUMEN

ABSTRACT Chromosome sizes of 71 phytoplasmas belonging to 12 major phylogenetic groups including several of the aster yellows subgroups were estimated from electrophoretic mobilities of full-length chromosomes in pulsed-field gels. Considerable variation in genome size, from 660 to 1,130 kilobases (kb), was observed among aster yellows phytoplasmas. Chromosome size heterogeneity was also observed in the stolbur phytoplasma group (range 860 to 1,350 kb); in this group, isolate STOLF contains the largest chromosome found in a phytoplasma to date. A wide range of chromosome sizes, from 670 to 1,075 kb, was also identified in the X-disease group. The other phytoplasmas examined, which included members of the apple proliferation, Italian alfalfa witches' broom, faba bean phyllody, pigeon pea witches' broom, sugarcane white leaf, Bermuda grass white leaf, ash yellows, clover proliferation, and elm yellows groups, all have chromosomes smaller than 1 megabase, and the size ranges within each of these groups is narrower than in the aster yellows, stolbur, and X-disease groups. The smallest chromosome, approximately 530 kb, was found in two Bermuda grass white leaf phytoplasma isolates. This not only is the smallest mollicute chromosome found to date, but also is the smallest chromosome known for any cell. More than one large DNA band was observed in several phytoplasma preparations. Possible explanations for the occurrence of more than one band may be infection of the host plant by different phytoplasmas, the presence of more than one chromosome in the same organism, or the presence of large extrachromosomal DNA elements.

14.
J Biochem Biophys Methods ; 36(2-3): 143-55, 1998 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-9711500

RESUMEN

Conventional isolation protocols for the parietal type of the gastric mucosal cell population are based on physical criteria such as cell size and cell density. Time-consuming centrifugation techniques are required, which decrease the overall yield and exert a negative influence on the functional integrity of purified cells. As an alternative, we now have developed a phenotype-dependent magnetic selection method. A monoclonal antibody (P1.4D5) was raised against rat parietal cells. After immunohistochemical, biochemical and functional characterization, P1.4D5 was used for rapid antibody-mediated magnetic cell sorting (MACS) of enzymatically dispersed gastric mucosal cells, which resulted in a 2.2- to 3-fold enrichment of parietal cells. Characterization of P1.4D5 demonstrated its applicability for parietal cell-specific immunostaining of formalin treated and paraffin-embedded tissue samples and cryosections from both rat and man. In vitro studies of the 14C-aminopyrine accumulation showed no intrinsic effect of P1.4D5 on the acid production of the parietal cell or on the histamine-stimulated acid production. This absence of negative influence on the parietal cell function qualifies P1.4D5 for immunomagnetic cell sorting procedures.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Separación Celular/métodos , Magnetismo , Células Parietales Gástricas/citología , Aminopirina/farmacocinética , Animales , Citometría de Flujo , Histamina/farmacología , Histocitoquímica , Humanos , Immunoblotting , Inmunohistoquímica , Ratas
15.
J Antibiot (Tokyo) ; 44(1): 59-65, 1991 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1825820

RESUMEN

In the course of our screening for antithrombotic compounds using platelet rich plasma from bovine slaughter blood, 2-methoxy-5-methyl-1,4-benzoquinone (1) has been isolated from mycelial cultures of Lentinus adhaerens. The compound inhibits the U46619-induced aggregation of human blood platelets with an IC50 of 2.5 micrograms/ml (16.45 microM) and is a new thromboxane A2 receptor antagonist. This is the first report on an inhibitor of platelet aggregation derived from secondary metabolism of basidiomycetes.


Asunto(s)
Antibacterianos/farmacología , Basidiomycota/metabolismo , Benzoquinonas/farmacología , Fibrinolíticos/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Receptores de Prostaglandina/efectos de los fármacos , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Benzoquinonas/química , Benzoquinonas/aislamiento & purificación , Fermentación , Fibrinolíticos/química , Fibrinolíticos/aislamiento & purificación , Humanos , Estructura Molecular , Inhibidores de Agregación Plaquetaria/química , Inhibidores de Agregación Plaquetaria/aislamiento & purificación , Receptores de Tromboxanos , Tromboxanos/antagonistas & inhibidores , Tromboxanos/metabolismo
16.
J Antibiot (Tokyo) ; 42(6): 875-82, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2500412

RESUMEN

Aleurodiscal, an antifungal antibiotic has been isolated from mycelial cultures of Aleurodiscus mirabilis (Berk. & Curt.) Höhn. It causes abnormal apical branchings of Mucor miehei hyphae at very low concentrations. The structure and absolute configuration of the antibiotic has been determined by a single crystal X-ray analysis and hydrolysis to D-(+)-xylose. Aleurodiscal is a hydroxysesterterpene aldehyde beta-D-xyloside with a novel carbon skeleton.


Asunto(s)
Aminoglicósidos , Antibacterianos/análisis , Antifúngicos/análisis , Basidiomycota/metabolismo , Mucor/efectos de los fármacos , Antibacterianos/biosíntesis , Antibacterianos/farmacología , Antifúngicos/biosíntesis , Antifúngicos/farmacología , Cromatografía Líquida de Alta Presión , Fermentación , Inmunodifusión , Estructura Molecular , Difracción de Rayos X
17.
Rofo ; 175(12): 1711-9, 2003 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-14661144

RESUMEN

PURPOSE: Imaging artifacts in magnetic resonance tomography (MRT) caused by metallic vascular implants (stents) were characterized systematically in dependence on the material and the construction of the implants as well as with respect to different measurement protocols and for different static field strength B (0). METHODS: Twelve stents, different in material (stainless steel, nitinol, Co-alloy) and/or construction, were examined at B (0) = 0.2 T and 1.0 T with two 2D gradient echo (GE) sequences (TE = 4 and 10 ms), one 3D GE sequence and one spin echo (SE) sequence. The stents were put into water with Gd-DTPA contrast agent. The dependence on the orientation was analyzed for the 9 possibilities of an orthogonal alignment of the stent axis, the direction of B (0), the slice, the read out, and the phase encoding direction. Special interest was given to the visibility of the stent lumen at forced rf excitation, as well as to the influence of broken struts on the signal obtained. RESULTS: For the examined stents GE technique showed, due to spin dephasing regions a total signal loss ranging up to 8 mm away from the stent mashes. The value depends on the stent material, the stent orientation in the scanner and grows with voxel size, echo time and B (0). In SE technique dephasing artifacts vanish and wrong spatial encoding gets visible, rf shielding is more pronounced. The visibility of the stent lumen ranges from nearly unperturbed down to a complete signal loss. An improvement is possible using enlarged flip angles. Broken struts can not be imaged significantly. DISCUSSION: The MR representation of metallic stents commercially available at the time, especially of nitionol stents, can be optimized with a suitable adaptation of the imaging parameters. However, a profound improvement can only be expected from new stent material and design.


Asunto(s)
Artefactos , Imagen por Resonancia Magnética , Stents , Aleaciones , Medios de Contraste , Gadolinio DTPA , Humanos , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética/métodos , Metales , Acero Inoxidable , Factores de Tiempo , Tomografía Computarizada por Rayos X
19.
Geburtshilfe Frauenheilkd ; 72(2): 132-136, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25374430

RESUMEN

Oncolytic viruses are replication competent "live" viruses. They infect tumor cells, replicate highly selective inside and thereby destroy them. Because of the enormous advances in the field of genetic engineering and biotechnology during the last decade, virotherapy is increasingly used within clinical trials and proved to be safe and effective. In particular, treatment of ovarian cancer patients is one main focus of research. On the one hand, this is due to the poor prognosis of this dismal entity, resulting in the urgent need for novel therapeutics. On the other hand, as ovarian cancer typically spreads within the peritoneal cavity, intraperitoneal administration of oncolytic viruses is feasible. This paper provides an overview of promising results from clinical trials to treat ovarian cancer patients with oncolytic viruses.

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