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1.
Ann Hematol ; 100(3): 809-816, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33496839

RESUMEN

Adult acute lymphoblastic leukemia/lymphoma (ALL/LBL) is a rare and heterogeneous malignancy characterized by uncontrolled proliferation of B or T cell precursor cells. Here, we retrospectively analyzed the outcome of early autologous stem cell transplantation in standard-risk patients in first complete remission (n=24) and of allogeneic transplantation in high and highest risk, and relapsed/refractory patients (n=35). The 10-year overall survival after autologous transplantation was 45%. The 10-year overall survival after allogeneic transplantation was 58%. The cumulative incidence of relapse was 29% after allogeneic and 67% after autologous transplantation. The cumulative incidence of non-relapse mortality was 0% after autologous and 12% after allogeneic transplantation. This retrospective single center analysis in a limited number of standard-risk patients clearly demonstrates that early autologous transplantation in first complete remission leads to an acceptable long-term outcome with a short overall treatment duration of less than 6 months compared with more than 2 years with conventional chemotherapy. More sensitive and standardized methods to detect minimal residual disease (MRD) will further help to identify those patients more accurately who are most likely to benefit from such a short and intensive treatment strategy (i.e., MRD negative standard-risk patients) or those who require early targeted therapy (e.g., blinatumomab) in case of MRD positivity. Early allogeneic transplantation results in long-term survival/cure in nearly two-thirds of all high and highest risk, and relapsed/refractory patients.


Asunto(s)
Intervención Médica Temprana , Trasplante de Células Madre de Sangre Periférica/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Adulto , Anciano , Austria/epidemiología , Intervención Médica Temprana/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasia Residual , Trasplante de Células Madre de Sangre Periférica/efectos adversos , Trasplante de Células Madre de Sangre Periférica/estadística & datos numéricos , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Recurrencia , Inducción de Remisión , Estudios Retrospectivos , Factores de Tiempo , Tiempo de Tratamiento , Trasplante Autólogo , Trasplante Homólogo , Resultado del Tratamiento , Adulto Joven
2.
Infection ; 49(1): 103-110, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33090329

RESUMEN

BACKGROUND: In this study we analyzed gender differences in the clinical presentation of patients with molecular confirmed influenza A. Additionally, we tried to identify predictors of influenza-associated mortality. MATERIALS/METHODS: In this prospective observational multi-center-study we included all influenza-positive patients ≥ 18 years who were hospitalized and treated on flu-isolation-wards in three hospitals in Vienna during the 2018/19 influenza season. Diagnoses were made via Cobas® Liat® POCT. RESULTS: 490 Patients (48.8% female) tested positive for influenza A. Female patients were older (median age 76 years vs. 70 years, p < 0.001). Male patients had a higher rate of chronic liver disease in history (8.8% vs. 2.9%, p = 0.006), myositis (11.7% vs. 3.1%, p < 0.001) and ICU admissions (9.6% vs. 4.6%, p = 0.03). The in-hospital mortality rate was 4.3% and increased to 9.5% during the 90-day follow-up period. Female patients > 75 years had a significantly higher in-hospital mortality rate than ≤ 75-year-old females (9.2% vs. 1.7%, p = 0.019). This effect was not observed in male patients (5.4% vs. 1.9%, p = ns). Age > 75 years (OR 5.49, 95% CI 1.10-27.43), acute heart failure (OR 3.56, 95% CI 1.03-12.05) and ICU admission (OR 6.1, 95% CI 0.98-37.91) were predictors for in-hospital mortality for female patients, while any malignancy (OR 9.4, 95% CI 1.90-46.54) and ICU admission (OR 7.05, 95% CI 1.44-34.55) were predictors in male patients. CONCLUSIONS: Gender is associated with differences in clinical presentation and complications of influenza A virus infection. Women with acute heart failure or aged > 75 years have an increased risk of influenza associated in-hospital mortality, while ICU admission and any malignancy are predictors for male patients. Mortality rates in patients > 75 years are 5-10 times higher compared to their non-hospitalized influenza-negative Austrian counterparts.


Asunto(s)
Virus de la Influenza A , Gripe Humana , Anciano , Anciano de 80 o más Años , Femenino , Hospitalización , Humanos , Gripe Humana/epidemiología , Gripe Humana/mortalidad , Gripe Humana/terapia , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores Sexuales
3.
Nano Lett ; 18(9): 5396-5400, 2018 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-30075629

RESUMEN

A strong increase of spontaneous radiative emission from colloidally synthesized CdSe/CdS/PMMA hybrid particles is achieved when manipulated into plasmonic bullseye resonators with the tip of an atomic force microscope (AFM). This type of antenna provides a broadband resonance, which may be precisely matched to the exciton ground state energy in the inorganic cores. Statistically analyzing the spectral photoluminescence (PL) of a large number of individual coupled and uncoupled CdSe/CdS/PMMA quantum dots, we find an order of magnitude of intensity enhancement due to the Purcell effect. Time-resolved PL shows a commensurate increase of the spontaneous emission rate with radiative lifetimes below 230 ps for the bright exciton transition. The combination of AFM and PL imaging allows for sub-200 nm localization of the particle position inside the plasmonic antenna. This capability unveils a different coupling behavior of dark excitonic states: even stronger PL enhancement occurs at positions with maximum spatial gradient of the nearfield, effectively adding a dipolar component to original quadrupole transitions. The broadband maximization of light-matter interaction provided by our nanoengineered compound systems enables an attractive class of future experiments in ultrafast quantum optics.

5.
Eur Phys J E Soft Matter ; 35(5): 37, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22623035

RESUMEN

We study the dynamics of oscillatory hair bundles which are coupled elastically in their deflection variable and are subject to noise. We present a stochastic description capturing the dynamics of the hair bundles' mean field. In particular, the presented derivation elucidates the origin of the previously described noise reduction by coupling. By comparison of simulations of the approximate dynamics and the full system, we verify our results. Furthermore, we demonstrate that the specific type of coupling considered implies coupling-induced changes in the dynamics beyond mere noise reduction.


Asunto(s)
Elasticidad , Células Ciliadas Auditivas Internas , Modelos Biológicos , Fenómenos Biomecánicos , Periodicidad , Procesos Estocásticos
6.
Biochemistry (Mosc) ; 76(7): 808-22, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21999543

RESUMEN

In silico analysis of available bacterial genomes revealed the phylogenetic proximity levels of enzymes responsible for biosynthesis of lipopolysaccharide (LPS) of Yersinia pestis, the cause of plague, to homologous proteins of closely related Yersinia spp. and some other bacteria (Serratia proteamaculans, Erwinia carotovora, Burkholderia dolosa, Photorhabdus luminescens and others). Isogenic Y. pestis mutants with single or double mutations in 14 genes of LPS biosynthetic pathways were constructed by site-directed mutagenesis on the base of the virulent strain 231 and its attenuated derivative. Using high-resolution electrospray ionization mass spectrometry, the full LPS structures were elucidated in each mutant, and the sequence of monosaccharide transfers in the assembly of the LPS core was inferred. Truncation of the core decreased significantly the resistance of bacteria to normal human serum and polymyxin B, the latter probably as a result of a less efficient incorporation of 4-amino-4-deoxyarabinose into lipid A. Impairing of LPS biosynthesis resulted also in reduction of LPS-dependent enzymatic activities of plasminogen activator and elevation of LD(50) and average survival time in mice and guinea pigs infected with experimental plague. Unraveling correlations between biological properties of bacteria and particular LPS structures may help a better understanding of pathogenesis of plague and implication of appropriate genes as potential molecular targets for treatment of plague.


Asunto(s)
Genes Bacterianos/fisiología , Lipopolisacáridos/biosíntesis , Yersinia pestis/enzimología , Yersinia pestis/genética , Amino Azúcares/metabolismo , Animales , Actividad Bactericida de la Sangre , Farmacorresistencia Bacteriana , Femenino , Cobayas , Humanos , Lípido A/biosíntesis , Masculino , Ratones , Peste/microbiología , Activadores Plasminogénicos/metabolismo , Polimixina B/farmacología , Espectrometría de Masa por Ionización de Electrospray , Virulencia , Yersinia pestis/efectos de los fármacos , Yersinia pestis/patogenicidad
7.
Biochemistry (Mosc) ; 75(4): 443-51, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20618133

RESUMEN

A knockout mutant with a deletion in a quorum sensing system gene qseC was generated from the vaccine strain Francisella tularensis 15 by site-directed mutagenesis. The variant with the inactivated gene qseC differed from the parental strain in growth rate on solid nutrient medium but had the same growth dynamics in liquid nutrient medium. The mutation abolished almost completely the resistance of the vaccine strain to normal rabbit serum and its ability to survive in macrophages; in addition, the strain lost the residual virulence. A significant phenotypic alteration was observed in the lipopolysaccharide of F. tularensis. Particularly, the mutant strain synthesized no noticeable amount of the lipopolysaccharide with the high-molecular-mass O-polysaccharide, presumably as a result of impairing biosynthesis of the repeating unit, namely, a loss of the ability to incorporate a formyl group, an N-acyl substituent of 4-amino-4,6-dideoxy-D-glucose.


Asunto(s)
Proteínas Bacterianas/genética , Francisella tularensis/genética , Lipopolisacáridos/química , Percepción de Quorum/genética , Animales , Vacunas Bacterianas/inmunología , Francisella tularensis/inmunología , Francisella tularensis/metabolismo , Técnicas de Inactivación de Genes , Mutagénesis Sitio-Dirigida , Antígenos O/química , Fenotipo , Conejos , Espectrometría de Masa por Ionización de Electrospray , Virulencia
8.
Bioorg Khim ; 36(3): 429-32, 2010.
Artículo en Ruso | MEDLINE | ID: mdl-20644600

RESUMEN

The full structure of the lipopolysaccharide core of bacteria Shigella flexneri types 2a and 5b, the causative agents of bacillary dysentery (shigellosis), was established by chemical methods, high-resolution electrospray ionization mass spectrometry, and two-dimensional NMR spectroscopy. The structure of the O-antigen repeating unit and the configuration and position of the linkage between the O-antigen and the core were determined in the lipopolysaccharide of S. flexneri type 2a.


Asunto(s)
Lipopolisacáridos/química , Oligosacáridos/química , Shigella flexneri/química , Secuencia de Carbohidratos , Datos de Secuencia Molecular , Shigella flexneri/aislamiento & purificación , Espectrometría de Masa por Ionización de Electrospray
9.
Eur Phys J E Soft Matter ; 29(4): 449-60, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19701785

RESUMEN

A deterministic system that operates in the vicinity of a Hopf bifurcation can be described by a single equation of a complex variable, called the normal form. Proximity to the bifurcation ensures that on the stable side of the bifurcation (i.e. on the side where a stable fixed point exists), the linear-response function of the system is peaked at the frequency that is characteristic of the oscillatory instability. Fluctuations, which are present in many systems, conceal the Hopf bifurcation and lead to noisy oscillations. Spontaneous hair bundle oscillations by sensory hair cells from the vertebrate ear provide an instructive example of such noisy oscillations. By starting from a simplified description of hair bundle motility based on two degrees of freedom, we discuss the interplay of nonlinearity and noise in the supercritical Hopf normal form. Specifically, we show here that the linear-response function obeys the same functional form as for the noiseless system on the stable side of the bifurcation but with effective, renormalized parameters. Moreover, we demonstrate in specific cases how to relate analytically the parameters of the normal form with added noise to effective parameters. The latter parameters can be measured experimentally in the power spectrum of spontaneous activity and linear-response function to external stimuli. In other cases, numerical solutions were used to determine the effects of noise and nonlinearities on these effective parameters. Finally, we relate our results to experimentally observed spontaneous hair bundle oscillations and responses to periodic stimuli.


Asunto(s)
Modelos Químicos , Movimiento (Física) , Modelos Lineales , Dinámicas no Lineales
10.
Structure ; 8(6): 585-92, 2000 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-10873859

RESUMEN

BACKGROUND: Lipopolysaccharide (LPS), a lipoglycan from the outer membrane of Gram-negative bacteria, is an immunomodulatory molecule that stimulates the innate immune response. High levels of LPS cause excessive release of inflammatory mediators and are responsible for the septic shock syndrome. The interaction of LPS with its cognate binding proteins has not, as yet, been structurally elucidated. RESULTS: The X-ray crystallographic structure of LPS in complex with the integral outer membrane protein FhuA from Escherichia coli K-12 is reported. It is in accord with data obtained using mass spectroscopy and nuclear magnetic resonance. Most of the important hydrogen-bonding or electrostatic interactions with LPS are provided by eight positively charged residues of FhuA. Residues in a similar three-dimensional arrangement were searched for in all structurally known proteins using a fast template-matching algorithm, and a subset of four residues was identified that is common to known LPS-binding proteins. CONCLUSIONS: These four residues, three of which form specific interactions with lipid A, appear to provide the structural basis of pattern recognition in the innate immune response. Their arrangement can serve to identify LPS-binding sites on proteins known to interact with LPS, and could serve as a template for molecular modeling of a LPS scavenger designed to reduce the septic shock syndrome.


Asunto(s)
Proteínas de Fase Aguda , Proteínas Portadoras/metabolismo , Proteínas de Escherichia coli , Lipopolisacáridos/química , Lipopolisacáridos/metabolismo , Glicoproteínas de Membrana , Proteínas de la Membrana Bacteriana Externa/química , Proteínas de la Membrana Bacteriana Externa/metabolismo , Sitios de Unión , Secuencia de Carbohidratos , Proteínas Portadoras/química , Cristalografía por Rayos X , Escherichia coli/química , Humanos , Enlace de Hidrógeno , Espectrometría de Masas , Modelos Moleculares , Datos de Secuencia Molecular , Unión Proteica , Conformación Proteica , Receptores Virales/química , Receptores Virales/metabolismo , Electricidad Estática
11.
Biochim Biophys Acta ; 1510(1-2): 185-97, 2001 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-11342157

RESUMEN

Highly purified bisphosphoryl, monophosphoryl and dephosphoryl lipids A from Erwinia carotovora with different acylation patterns were characterized physico-chemically. Applying matrix assisted laser desorption/ionization mass spectrometry, the purity of the lipid A fractions was determined, and from monolayer measurements the molecular space requirement was estimated. Fourier transform infrared spectroscopy allowed the elucidation of the gel to liquid crystalline phase transition of the acyl chains as well as the determination of the tilt angle of the diglucosamine backbone with respect to the acyl chain direction applying dichroitic measurements with attenuated total reflectance. With synchrotron radiation small-angle X-ray diffraction the supramolecular aggregate structure was determined, and with fluorescence resonance energy transfer spectroscopy the lipopolysaccharide binding protein induced intercalation of lipid A into a phospholipid matrix corresponding to that of the macrophage membrane was investigated. From the results, a clear dependence of the physico-chemical parameters on the particular lipid A structure can be followed. Furthermore, these parameters correlate well with the biological activities of the various lipids A as deduced from their ability to induce biological activity (Limulus assay and cytokine induction in mononuclear cells). These results contribute to a closer interpretation of the physico-chemical prerequisites for endotoxic activity as found for enterobacterial lipid A.


Asunto(s)
Erwinia/fisiología , Lípido A/análisis , Lipopolisacáridos/química , Aire , Erwinia/química , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Prueba de Limulus , Lípido A/análogos & derivados , Lípido A/farmacología , Conformación Molecular , Estructura Molecular , Fosfolípidos/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Temperatura , Factor de Necrosis Tumoral alfa/biosíntesis , Agua , Difracción de Rayos X
12.
J Endotoxin Res ; 11(5): 299-303, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16263003

RESUMEN

Lipopolysaccharide (LPS) is the eminent lipid component of the outer leaflet of the outer membrane of Gram-negative bacteria and the major initiator of innate immune response to bacterial infection. Below the critical micellar concentration (CMC), LPS is exclusively present as a monomer. Above this concentration, aggregates are formed. Increasing the concentration beyond the CMC leads to an increase in aggregate concentration, whereas the concentration of monomers remains constant or even decreases. The question how LPS activates immune cells and whether the aggregate or the monomer is the biologically active unit has been and still is controversial. To prepare clearly defined monomeric solutions, we utilized a dialysis set-up consisting of a donor and an acceptor chamber, separated by a dialysis diaphragm with a cut-off of 5 kDa, thus allowing only monomers to pass. Human mononuclear cells (MNCs) were then stimulated with equal concentrations of aggregates and monomers, respectively, of deep rough mutant LPS from Escherichia coli strain F515 (Re LPS) and TNF-alpha release was determined. In contrast to earlier and very recent work of others, we started with a preparation of aggregate-suspensions and pure monomer-solutions and show that monomers are significantly less active than aggregates in the absence and presence of serum proteins at identical concentrations. In our model, we propose that LPS aggregates are detected by membrane-associated LBP and intercalated into the cell membrane to bring LPS into close proximity to signaling proteins in the membrane, thus finally leading to cell activation. To support this model, we present data showing that LBP is indeed present in or at the cell membrane of human macrophages.


Asunto(s)
Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Membrana Celular , Escherichia coli/patogenicidad , Infecciones por Bacterias Gramnegativas/inmunología , Infecciones por Bacterias Gramnegativas/fisiopatología , Humanos , Leucocitos Mononucleares , Macrófagos/fisiología , Modelos Teóricos , Factor de Necrosis Tumoral alfa/metabolismo
13.
J Invest Dermatol ; 117(5): 1126-36, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11710923

RESUMEN

Ceramides and glucosylceramides are pivotal molecules in multiple biologic processes such as apoptosis, signal transduction, and mitogenesis. In addition, ceramides are major structural components of the epidermal permeability barrier. The barrier ceramides derive mainly from the enzymatic hydrolysis of glucosylceramides. Recently, anti-ceramide and anti-glucosylceramide anti-sera have become available that react specifically with several epidermal ceramides and glucosylceramides, respectively. Here we demonstrate the detection of two epidermal covalently bound omega-hydroxy ceramides and one covalently bound omega-hydroxy glucosylceramide species by thin-layer chromatography immunostaining. Moreover, we show the ultrastructural distribution of ceramides and glucosylceramides in human epidermis by immunoelectron microscopy on cryoprocessed skin samples. In basal epidermal cells and dermal fibroblasts ceramide was found: (i) at the nuclear envelope; (ii) at the inner and outer mitochondrial membrane; (iii) at the Golgi apparatus and the endoplasmic reticulum; and (iv) at the plasma membrane. The labeling density was highest in mitochondria and at the inner nuclear membrane, suggesting an important role for ceramides at these sites. In the upper epidermis, ceramides were localized: (i) in lamellar bodies; (ii) in trans-Golgi network-like structures; (iii) at the cornified envelope; and (viii) within the intercellular space of the stratum corneum, which is in line with the known analytical data. Glucosylceramides were detected within lamellar bodies and in trans-Golgi network-like structures of the stratum granulosum. The localization of glucosylceramides at the cornified envelope of the first corneocyte layer provides further proof for the existence of covalently bound glucosylceramides in normal human epidermis.


Asunto(s)
Ceramidas/metabolismo , Epidermis/metabolismo , Glucosilceramidas/metabolismo , Membrana Celular/metabolismo , Cromatografía en Capa Delgada , Retículo Endoplásmico/metabolismo , Retículo Endoplásmico/ultraestructura , Células Epidérmicas , Epidermis/ultraestructura , Fibroblastos/metabolismo , Fibroblastos/ultraestructura , Aparato de Golgi/metabolismo , Aparato de Golgi/ultraestructura , Humanos , Inmunohistoquímica , Membranas Intracelulares/metabolismo , Membranas Intracelulares/ultraestructura , Microscopía Inmunoelectrónica , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , Membrana Nuclear/metabolismo , Membrana Nuclear/ultraestructura , Valores de Referencia , Coloración y Etiquetado , Distribución Tisular
14.
J Endotoxin Res ; 7(2): 133-46, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11521094

RESUMEN

We here report on the structural analysis of a novel tetra-acyl lipid A (LA (tetra) ) isolated from Escherichia coli deep rough (Re)-mutant strain F515. In addition to the biologically active hexa-acyl E. coli-type lipid A (compound 506), this incompletely acylated lipid A was found to be also present in the native LPS. Its structure was studied without further derivatisation by chemical analysis, matrix-assisted laser desorption/ionization mass spectrometry, and one- and two-dimensional (1)H- and (13)C-NMR spectroscopy. It was found to be structurally distinct from the tetra-acyl lipid A biosynthetic precursor Ia (compound 406) in lacking the primary (R)-3-hydroxytetradecanoic acid 14:0(3-OH) in position 3' ester-linked to the 'non-reducing' glucosamine (GlcN II). The hydroxyl group at the (R)-3-hydroxytetradecanoic acid attached to position 2' of GlcN II was found to be substituted by dodecanoic acid (12:0), thus forming a dodecanoyloxytetradecanoyl residue 14:0[3-O(12:0)]. The acylation pattern at the 'reducing' GlcN I was identical to that of compound 406 in having two primary (R)-3-hydroxy tetradecanoic acid residues [14:0(3-OH)] attached to positions 3 (ester-linked) and 2 (amide-linked), respectively. In human mononuclear cells (hMNC) the new LA (tetra) antagonized LPS-induced release of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in a dose-dependent manner with identical antagonistic potency as compared with compound 406. Also like compound 406, it was found to be an agonist in murine macrophage-like J774.1 cells.


Asunto(s)
Endotoxinas/antagonistas & inhibidores , Escherichia coli/química , Lípido A/química , Lípido A/toxicidad , Monocitos/efectos de los fármacos , Animales , Células Cultivadas , Cromatografía en Capa Delgada , Relación Dosis-Respuesta Inmunológica , Humanos , Interleucina-6/metabolismo , Lípido A/inmunología , Lípido A/aislamiento & purificación , Activación de Linfocitos , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Espectroscopía de Resonancia Magnética , Ratones , Estructura Molecular , Monocitos/inmunología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Factor de Necrosis Tumoral alfa/metabolismo
15.
J Endotoxin Res ; 9(3): 181-6, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12831460

RESUMEN

We have previously shown in patch-clamp experiments on excised outside-out cytoplasmic membrane patches from human macrophages that the activation of a high-conductance Ca(2+)- and voltage-dependent potassium channel, the MaxiK channel, is an early step in LPS-induced transmembrane signal transduction in macrophages. MaxiK can be activated by agonistically active LPS, and activation can be completely inhibited by LPS antagonists (e.g. synthetic compound 406) and by anti-CD14 antibodies. Furthermore, by inhibiting MaxiK with the specific MaxiK blocker paxilline, we could show that activation of MaxiK is essential for LPS-induced cytokine production. As shown by RT-PCR, blockade of MaxiK by paxilline also inhibits induction of the mRNA of TNF-alpha and IL-6. This observation together with the fact that all patch-clamp experiments were done on excised outside-out patches reveal that MaxiK activation is an early step in cell activation by endotoxins. Thus, since cells lacking TLR4 on their surface can also not be activated to produce cytokines, these data allow the conclusion that TLR4 and MaxiK are both essential for activation by LPS and may form a co-operative signaling complex. We have also shown that LBP not only exists as a soluble acute-phase serum protein, but is also incorporated as a transmembrane protein (mLBP) in the cytoplasmic membrane of MNC; in this configuration, it is obviously involved in the binding of endotoxin and its transfer to the transmembrane signaling proteins finally triggering cell activation. Complexation of soluble LBP and LPS in the serum prior to binding of LPS to mLBP, in contrast, leads to neutralization of LPS. Here, we provide evidence from fluorescence resonance energy transfer spectroscopy that endotoxin aggregates are intercalated into reconstituted membranes by mLBP. In addition, cell culture assays and patch-clamp experiments demonstrate that endotoxin activates macrophages and the MaxiK channel in the aggregated, but not in the monomeric, state at similar concentrations.


Asunto(s)
Proteínas de Fase Aguda , Proteínas Portadoras/metabolismo , Membrana Celular/efectos de los fármacos , Lípido A/análogos & derivados , Lipopolisacáridos/farmacología , Activación de Macrófagos/efectos de los fármacos , Glicoproteínas de Membrana , Canales de Potasio Calcio-Activados/metabolismo , Anticuerpos Bloqueadores/farmacología , Membrana Celular/metabolismo , Células Cultivadas , Glucolípidos/farmacología , Humanos , Indoles/farmacología , Interleucina-6/genética , Interleucina-6/metabolismo , Subunidades alfa de los Canales de Potasio de Gran Conductancia Activados por Calcio , Canales de Potasio de Gran Conductancia Activados por el Calcio , Lípido A/farmacología , Receptores de Lipopolisacáridos/inmunología , Lipopolisacáridos/antagonistas & inhibidores , Sustancias Macromoleculares , Activación de Macrófagos/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Técnicas de Placa-Clamp , Canales de Potasio Calcio-Activados/antagonistas & inhibidores , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Salmonella enterica/química , Transducción de Señal , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
16.
J Med Chem ; 37(25): 4407-11, 1994 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-7996553

RESUMEN

Ten halogenated monoterpenes (2-6 and 8-12) related to the novel antitumor compound halomon (1) or to the carbocyclic analog 7 have been isolated from different geographic collections of the red alga, Portieria hornemannii. Structures were assigned to the basis of spectral analyses (primarily NMR and MS). The absolute configuration of isohalomon (2) was further established by X-ray crystallography. The compounds were comparatively evaluated alongside 1 and 7 in the U.S. National Cancer Institute's in vitro human tumor cell line screening panel. The results provide some interesting initial insights into the structure/activity relationships in this series.


Asunto(s)
Antineoplásicos/aislamiento & purificación , Hidrocarburos Halogenados/química , Rhodophyta , Terpenos/aislamiento & purificación , Antineoplásicos/química , Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Simulación por Computador , Cristalografía por Rayos X , Humanos , Hidrocarburos Halogenados/farmacología , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Modelos Moleculares , Conformación Molecular , Estructura Molecular , Terpenos/química , Terpenos/farmacología , Células Tumorales Cultivadas
17.
Hum Pathol ; 32(10): 1136-40, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11679949

RESUMEN

We report a 52-year-old woman who underwent otoneurosurgery to resect acoustic neurinoma. Bone reconstruction was performed with an aluminium (Al)-containing cement. Six weeks later the patient suffered from loss of consciousness, myoclonic jerks, and persistent grand mal seizures, clinical symptoms that resembled those of lethal dialysis encephalopathy of the 1960s and 1970s. She died 6 months later because of septic complications. Light- and electron-microscopic investigation of the central nervous system (CNS) showed pathognomonic Al-containing intracytoplasmic argyrophilic inclusions in choroid plexus epithelia, neurons, and cortical glia. These changes are characteristics of dialysis-associated encephalopathy (DAE), induced nowadays by long-term ingestion of Al-containing drugs (and with benign clinical courses). Atomic absorption spectrometry showed an increase of mean bulk Al concentration of the cortex and subcortex up to 9.3 microg/g (normal range <2 microg/g); laser microprobe showed the increase of Al in subcellular structures. This unique case again shows the extraordinary neurotoxicity of Al, which was, in our patient, initiated by an amount of about 30 mg Al and apparently caused by direct Al access to the brain parenchyma via a cerebrospinal fluid leakage.


Asunto(s)
Aluminio/envenenamiento , Encefalopatías/inducido químicamente , Oído Interno/cirugía , Complicaciones Posoperatorias , Aluminio/análisis , Silicatos de Aluminio/efectos adversos , Silicatos de Aluminio/química , Materiales Biocompatibles/efectos adversos , Materiales Biocompatibles/química , Cementos para Huesos/efectos adversos , Cementos para Huesos/química , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Química Encefálica , Encefalopatías/patología , Resultado Fatal , Femenino , Cementos de Ionómero Vítreo/efectos adversos , Humanos , Persona de Mediana Edad , Convulsiones/etiología
18.
Virchows Arch ; 424(1): 105-12, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7981897

RESUMEN

We have described new silver-staining methods for the demonstration of lesions in senile dementia of the Alzheimer type. The same procedure was used to visualize characteristic aluminium (Al)-containing inclusions in choroid epithelium, glia and neurons of the central nervous system in dialysis-associated encephalopathy (DAE). Here we describe the patterns and degree of Al deposition in extracerebral tissues of 12 DAE autopsy cases. Light microscopy of silver-stained paraffin sections demonstrated autonomic ganglion cells filled with numerous intracytoplasmic black-stained fine granular inclusions, which were also seen in endocrine tissues (pituitary, parathyroid and adrenal) and in Leydig cells. Heart, liver cells and the testicular tubules were involved, but decalcified bones, haematopoetic elements, hyperplastic epithelium and one case of malignant epithelium lacked inclusions. Laser microprobe mass analysis revealed prominent Al-related mass signals within the en-bloc silver-stained inclusions which were seen at low intensity in adjacent non-stained structures. Electron microscopy demonstrated accumulations of small electron-dense granules intermingling with lipopigments.


Asunto(s)
Aluminio/análisis , Encefalopatías/etiología , Diálisis Renal/efectos adversos , Adulto , Anciano , Huesos/química , Encefalopatías/metabolismo , Glándulas Endocrinas/química , Femenino , Humanos , Riñón/química , Células Intersticiales del Testículo/química , Hígado/química , Tejido Linfoide/química , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Miocardio/química , Tinción con Nitrato de Plata , Testículo/química
19.
Int J Antimicrob Agents ; 4(4): 271-9, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-18611617

RESUMEN

In vitro drug effects on Mycobacterium leprae (M. leprae) in a cell-free system have been monitored by mass spectrometric determination of the ratio of the intrabacterial concentrations of the sodium and potassium ions (Na(+), K(+) ratio) of a limited number of individual bacteria per sample. From the drug-induced increase of the median values of the distributions of the Na(+), K(+) ratio, information on the concentration and time dependence of drug effects as well as on antagonistic or synergistic interactions of drugs has been obtained. Moreover, absolute values for the percentage of killed bacteria (% kill) have been derived from the distribution of the Na(+), K(+) ratios within a bacterial population. For this, the limiting value of the Na(+), K(+) ratio (up to which bacteria are viable) -which had been determined as 0.45 for cultivable bacteria - has been presumed to be valid also for M. leprae. Highest killing rates have been observed for fusidic acid and clarithromycin, followed by rifabutine, rifampin, and clofazimine. Minocycline and dapsone have shown only moderate killing effects and isoniazid and - probably due to the restricted metabolism of M. leprae in a cell-free medium - ofloxacin have been completely inactive. Strong ofloxacin effects, however, have been observed for cultivable mycobacteria and intracellular M. leprae phagocytized by a murine macrophage cell line.

20.
Int J Antimicrob Agents ; 2(2): 117-28, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18611531

RESUMEN

Drug are generally screened for activity against Mycobacterium leprae by administration to M. leprae-infected mice, and the efficacy of a chemotherapeutic regimen is assessed by inoculating mice with M. leprae recovered from the skin-biopsy specimens obtained at intervals during treatment. Both methods are expensive and time consuming. Although a number of methods has been proposed for the rapid distinction between viable and non viable M. leprae, none has found wide acceptance. Earlier work had shown that the ratios of the intrabacterial concentrations of Na(+) and K(+) (Na(+),K(+)-ratio) of individual bacterial cells, measured by means of laser microprobe mass analysis, are a sensitive indicator of the viability of cultivable organisms. Assuming that the maximal value (the "limiting value") of the Na(+),K(+)-ratio of viable cultivable organisms is valid for non-cultivable species, the degree of correspondence between intrabacterial Na(+),K(+)-ratios of M. lepraemurium after treatment in vivo with isoniazid, streptomycin and clofazimine, and the ability of these organisms to multiply in mice were examined. A linear relationship between the proportion of viable organisms, calculated from the limiting value of the Na(+),K(+)-ratio, and that calculated from ID50 was found, suggesting that, at least for M. lepraemurium, the intrabacterial Na(+),K(+)-ratio predicts the effect of drugs measured by the much more demanding technique of mouse inoculation.

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