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1.
Trop Med Int Health ; 26(1): 89-101, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33012038

RESUMEN

OBJECTIVES: Accurate serological assays are urgently needed to support public health responses to Zika virus (ZIKV) infection with its potential to cause foetal damage during pregnancy. Current flavivirus serology for ZIKV infections lacks specificity due to cross-reacting antibodies from closely related other flaviviruses. In this study, we evaluated novel serological tests for accurate ZIKV IgG detection. METHODS: Our ELISAs are based on immune complex binding. The high specificity is achieved by the simultaneous incubation of labelled ZIKV antigen and unlabelled flavivirus homolog protein competitors. Two assays were validated with a panel of 406 human samples from PCR-confirmed ZIKV patients collected in Brazil (n = 154), healthy blood donors and other infections from Brazil, Europe, Canada and Colombia (n = 252). RESULTS: The highest specificity (100% [252/252, 95% confidence interval (CI) 98.5-100.0]) was shown by the ZIKV ED3 ICB ELISA using the ED3 antigen of the ZIKV envelope. A similar test using the NS1 antigen (ZIKV NS1 ICB ELISA) was slightly less specific (92.1% [232/252, 95% CI 88.0-95.1]). The commercial Euroimmun ZIKV ELISA had a specificity of only 82.1% (207/252, 95% CI 76.8-86.7). Sensitivity was high (93-100%) from day 12 after onset of symptoms in all three tests. Seroprevalence of ZIKV IgG was analysed in 87 samples from Laos (Asia) confirming that the ED3 ELISA showed specific reactions in other populations. CONCLUSIONS: The novel ED3 ICB ELISA will be useful for ZIKV-specific IgG detection for seroepidemiological studies and serological diagnosis for case management in travellers and in countries where other flavivirus infections are co-circulating.


Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Inmunoglobulina G/sangre , Infección por el Virus Zika/sangre , Infección por el Virus Zika/diagnóstico , Virus Zika/aislamiento & purificación , Adolescente , Adulto , Anciano , Complejo Antígeno-Anticuerpo/inmunología , Brasil , Niño , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Humanos , Inmunoglobulina G/inmunología , Laos , Masculino , Persona de Mediana Edad , Embarazo , Sensibilidad y Especificidad , Estudios Seroepidemiológicos , Pruebas Serológicas , Adulto Joven , Virus Zika/inmunología , Infección por el Virus Zika/inmunología
2.
Hum Reprod ; 35(11): 2515-2523, 2020 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-32914172

RESUMEN

STUDY QUESTION: What is the reason for insufficient contraceptive efficacy of levonorgestrel (LNG) delivered by intravaginal ring (IVR) releasing comparable amounts of LNG as approved progestogen-only pills (POPs)? SUMMARY ANSWER: The pharmacokinetic (PK) evaluation in a subpopulation indicated that the steady-state concentration of plasma LNG was markedly lower in the participants in the USA compared to those in Japan suggesting non-compliance in the US participants which may explain a clearly higher Pearl Index (PI) in USA (8.2, unadjusted PI) compared to Japan (1.4, unadjusted PI). WHAT IS KNOWN ALREADY: Contraceptive efficacy of LNG in POPs has been demonstrated following different routes of administration (e.g. orally, implants, intrauterine systems), and the PK is well-characterized including a target exposure needed for contraception. Exposure above this target concentration was reached in Phase 1 studies using IVR delivering 40 µg LNG per day. STUDY DESIGN, SIZE, DURATION: The primary objective of this multicenter, open-label, single-arm study conducted in the USA and in Japan was to assess the contraceptive efficacy of an LNG-containing IVR during a planned treatment period of 1 year in healthy women 18-35 years of age. The study was planned to be conducted in 1600 participants (1300 in the USA, 300 in Japan). The study was prematurely terminated after approximately one-third of the planned exposure was reached due to a high number of pregnancies (28) in the US study population. PARTICIPANTS/MATERIALS, SETTING, METHODS: In total, 1471 participants were treated (1166 participants in the USA and 305 participants in Japan). The PI as a measure of contraceptive efficacy was calculated from the frequency of unintended pregnancies during treatment. LNG exposure in the systemic circulation was assessed during treatment in 136 participants (PK subgroups: 106 in the USA and 30 in Japan). MAIN RESULTS AND THE ROLE OF CHANCE: The PK evaluation in the PK subgroups indicated that the steady-state concentration of plasma LNG after 6 months was markedly lower in the participants in the USA (geometric mean 91.2 ng/l) compared to those in Japan (263.8 ng/l). This PK finding cannot be explained by the regional differences in body weight observed between the PK subgroups, thus suggesting non-compliance in the US participants. In 15.7% of the samples collected in the USA and 3.5% samples in Japan, the LNG concentration at steady state was below the lower limit of quantification (10 ng/l), which is not expected with the required continuous use of the IVR documented in most of the eDiaries. LIMITATIONS, REASONS FOR CAUTION: The planned duration of treatment was 12 months, but due to the premature termination of the study none of the participants completed the 12-month treatment. All data collected until the study termination were considered, but it is to be noted that the amount of missing data limits the conclusions that can be drawn from the data. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study triggered the termination of the project, because the objective to show sufficient contraceptive efficacy of the LNG IVR was not met. The choice of a user-dependent contraceptive method with an LNG dose that is not inhibiting ovulation is not advisable for women who may have compliance issues. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by Bayer AG and all authors are employees of Bayer AG. TRIAL REGISTRATION NUMBER: NCT02403401.


Asunto(s)
Anticonceptivos Femeninos , Dispositivos Intrauterinos Medicados , Anticoncepción , Efectividad Anticonceptiva , Femenino , Humanos , Japón , Levonorgestrel , Cooperación del Paciente , Embarazo
3.
Hum Reprod ; 31(8): 1713-22, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27390369

RESUMEN

STUDY QUESTION: What are suitable doses of the aromatase inhibitor anastrozole (ATZ) and the progestin levonorgestrel (LNG), when delivered to the systemic circulation by an intravaginal ring (IVR), for further clinical development as a potential new therapy for the treatment of endometriosis? SUMMARY ANSWER: Anticipated targets for pharmacokinetics, pharmacodynamics and safety/tolerability were achieved for both drug components of the IVR at the doses investigated, supporting selection of the doses to be investigated in Phase 2 studies. WHAT IS KNOWN ALREADY: Aromatase is a key enzyme in the biosynthesis of estrogens and is known to increase local levels of estradiol (E2) at extragonadal sites. Up-regulation of aromatase expression has been demonstrated in endometriotic lesions and the use of oral aromatase inhibitors has been shown to reduce endometriosis-associated pelvic pain in small-scale clinical trials. STUDY DESIGN, SIZE, DURATION: This Phase 1, randomized, multicentre, parallel-group, three-arm, open-label study assessed the pharmacokinetics, pharmacodynamics, safety and tolerability of various IVRs intended for systemic drug delivery. After screening, healthy, ovulating women aged 18-35 years were randomized to use IVRs releasing one of the three ATZ/LNG dose combinations (in vitro nominal daily drug release rates on Day 29: ATZ/LNG 500 µg/20 µg [low dose], ATZ/LNG 1000 µg/30 µg [mid dose] or ATZ/LNG 1500 µg/40 µg [high dose]) for two consecutive 28-day wearing periods without a treatment break. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sixty women were included in the per protocol set. The primary variables were plasma concentrations of ATZ and LNG at the end of each treatment period and the mean size of largest follicle-like structures (FLSs) over 56 days. Serum concentrations of several hormones were also evaluated, with emphasis on E2 levels. MAIN RESULTS AND THE ROLE OF CHANCE: At the end of the first treatment period, geometric mean plasma concentrations of LNG and ATZ, respectively, were 0.228 and 12.5 µg/l for the low dose, 0.269 and 19.8 µg/l for the mid dose and 0.384 and 37.3 µg/l for the high dose; results were similar at the end of the second treatment period. Over the entire treatment period, mean FLS sizes were higher in all three treatment groups than during the pretreatment cycle; more women in the mid- and high-dose groups had FLSs of at least 30 mm (32-45%) than those in the low-dose group (14-24%). Changes in the mean size of FLSs were similar to those reported for low-dose progestin-only oral contraceptives and generally resolved during the 2-month treatment period. Serum E2 levels were decreased, but only one woman in each of the mid- and high-dose groups, and no woman in the low-dose group, had a serum E2 level below 20 pg/ml in both cycles. All ATZ and LNG combinations showed good tolerability. LIMITATIONS, REASONS FOR CAUTION: This was an exploratory study; no formal power calculation was performed. WIDER IMPLICATIONS OF THE FINDINGS: The results of this first-in-human study of the ATZ/LNG IVR facilitated the selection of ATZ and LNG doses to be investigated in the Phase 2 studies of patients with endometriosis. STUDY FUNDING/COMPETING INTEREST: The study was funded by Bayer Pharma AG. T.R. is an employee of DINOX GmbH, which received funding from Bayer Pharma AG to perform this study. M.-H.S.-M., K.W., R.N., S.K., J.K., H.S. and B.R. are or have been employees of Bayer Pharma AG. H.S. is a named inventor on EP 2 552 404 B1, a patent application relating to this work. TRIAL REGISTRATION NUMBER: EudraCT number: 2011-005620-18. TRIAL REGISTRATION DATE: 16 November 2011. DATE OF FIRST PATIENT'S ENROLMENT: 14 March 2012.


Asunto(s)
Inhibidores de la Aromatasa/farmacología , Levonorgestrel/farmacología , Nitrilos/farmacología , Folículo Ovárico/efectos de los fármacos , Triazoles/farmacología , Administración Intravaginal , Adulto , Anastrozol , Inhibidores de la Aromatasa/administración & dosificación , Inhibidores de la Aromatasa/efectos adversos , Inhibidores de la Aromatasa/farmacocinética , Endometriosis/tratamiento farmacológico , Estradiol/sangre , Femenino , Voluntarios Sanos , Humanos , Levonorgestrel/administración & dosificación , Levonorgestrel/efectos adversos , Levonorgestrel/farmacocinética , Nitrilos/administración & dosificación , Nitrilos/efectos adversos , Nitrilos/farmacocinética , Premenopausia , Triazoles/administración & dosificación , Triazoles/efectos adversos , Triazoles/farmacocinética , Salud de la Mujer , Adulto Joven
4.
Biomater Adv ; 136: 212754, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35929289

RESUMEN

Current alloplastic materials such as PMMA, titanium or PEEK don't show relevant bone ingrowth into the implant when used for cranioplasty, ceramic implants have the drawback being brittle. New materials and implant designs are urgently needed being biocompatible, stable enough for cranioplasty and stimulating bone formation. In an in vivo critical size sheep model circular cranial defects (>2.4 cm) were covered with three different types of a 3D-printed porous titanium scaffolds with multidirectional, stochastically distributed architecture (uncoated scaffold, hydroxyapatite-coated scaffold, uncoated scaffold filled with a calcium phosphate bone cement paste containing ß-TCP granules). An empty titanium mesh served as control. Among the different investigated setups the hydroxyapatite-coated scaffolds showed a surprisingly favourable performance. Push-out tests revealed a 2.9 fold higher force needed in the hydroxyapatite-coated scaffolds compared to the mesh group. Mean CT density at five different points inside the scaffold was 2385HU in the hydroxyapatite-coated group compared to 1978HU in the uncoated scaffold at nine months. Average lateral bone ingrowth after four months in the hydroxyapatite-coated scaffold group was up to the implant center, 12.1 mm on average, compared to 2.8 mm in the control group covered with mesh only. These properties make the investigated scaffold with multidirectional, stochastically distributed structure superior to all products currently on the market. The study gives a good idea of what future materials for cranioplasty might look like.


Asunto(s)
Prótesis e Implantes , Titanio , Animales , Cementos para Huesos , Durapatita/farmacología , Impresión Tridimensional , Ovinos , Cráneo/diagnóstico por imagen , Titanio/química
5.
Orthopade ; 40(7): 624-6, 628-9, 2011 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-21327613

RESUMEN

We present the case of a patient with Klippel-Trenaunay syndrome (KTS) who underwent a one-stage revision of an infected total knee arthroplasty. A detailed orthopedic description of KT is presented as well as a discussion on the implementation of one-stage or multi-stage revision following infections of total knee arthroplasty. Due to vascular anomalies with severe coagulation problems, soft tissue swelling and increased risk of infection, surgical treatment of such patients presents a special challenge.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Síndrome de Klippel-Trenaunay-Weber/cirugía , Prótesis de la Rodilla , Infecciones Relacionadas con Prótesis/cirugía , Infecciones por Proteus/cirugía , Proteus mirabilis , Estudios de Seguimiento , Humanos , Síndrome de Klippel-Trenaunay-Weber/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Falla de Prótesis , Infecciones Relacionadas con Prótesis/diagnóstico por imagen , Infecciones por Proteus/diagnóstico por imagen , Radiografía , Reoperación
6.
J Cell Biol ; 139(3): 695-707, 1997 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-9348286

RESUMEN

Rigor insect flight muscle (IFM) can be relaxed without ATP by increasing ethylene glycol concentration in the presence of adenosine 5'-[beta'gamma- imido]triphosphate (AMPPNP). Fibers poised at a critical glycol concentration retain rigor stiffness but support no sustained tension ("glycol-stiff state"). This suggests that many crossbridges are weakly attached to actin, possibly at the beginning of the power stroke. Unaveraged three-dimensional tomograms of "glycol-stiff" sarcomeres show crossbridges large enough to contain only a single myosin head, originating from dense collars every 14.5 nm. Crossbridges with an average 90 degrees axial angle contact actin midway between troponin subunits, which identifies the actin azimuth in each 38.7-nm period, in the same region as the actin target zone of the 45 degrees angled rigor lead bridges. These 90 degrees "target zone" bridges originate from the thick filament and approach actin at azimuthal angles similar to rigor lead bridges. Another class of glycol-PNP crossbridge binds outside the rigor actin target zone. These "nontarget zone" bridges display irregular forms and vary widely in axial and azimuthal attachment angles. Fitting the acto-myosin subfragment 1 atomic structure into the tomogram reveals that 90 degrees target zone bridges share with rigor a similar contact interface with actin, while nontarget crossbridges have variable contact interfaces. This suggests that target zone bridges interact specifically with actin, while nontarget zone bridges may not. Target zone bridges constitute only approximately 25% of the myosin heads, implying that both specific and nonspecific attachments contribute to the high stiffness. The 90 degrees target zone bridges may represent a preforce attachment that produces force by rotation of the motor domain over actin, possibly independent of the regulatory domain movements.


Asunto(s)
Adenilil Imidodifosfato/farmacología , Glicol de Etileno/farmacología , Hemípteros/química , Relajación Muscular/efectos de los fármacos , Músculos/química , Músculos/ultraestructura , Actinas/química , Actinas/ultraestructura , Animales , Cristalografía por Rayos X , Vuelo Animal , Procesamiento de Imagen Asistido por Computador , Microscopía Electrónica , Subfragmentos de Miosina/química , Subfragmentos de Miosina/ultraestructura
7.
Eur J Med Res ; 13(8): 355-65, 2008 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-18952517

RESUMEN

At first ADV is presented as a typical pandemic. The contagiosity of adenovirus is high because of the viability of the virus on inorganic surfaces in medical offices up to 35 days. Outbreaks and epidemics occur 3-30 days after infection, which is mainly contracted from medical facilities. EKC is considered a notifiable condition in most countries, and outbreaks, suspects and infections must be reported. Symptoms like "pink eye", foreign body sensations, photophobia, pain, signs such as follicles, hemorrhages and corneal infiltrates, and vision decrease associated with malaise are frequently observed first in one eye, later involving the fellow eye. Unilateral disease has a high rate of misdiagnosis. Currently no vaccine or virustatic is available, which is effective, cost-efficient and tolerable. Treatment is symptomatic and antiinflammatory. Late scarring may be amenable to phototherapeutic keratectomy. Infection control measures focus on the disinfection of equipment and hands of staff, the handling of infected patients with gloves, spatial separation of infected individuals resp. cohorting of infected patients, use of unit-dose eye solutions, and the chlorination of pools by approved and registered disinfectants and germicides. In connection with this it is shown how to handle the dynamics of infections by mathematical models like cellular automation, systems of differential equations and to visualize periodic effects by Fourier Analysis and to calculate costs by mathematical programming. Using mathematical analysis the percentage of a population needing vaccination to prevent spreading of pandemic can be calculated. It is shown here that especially the method of cellular automation is a simple way to simulate complex epidemiological situations without completely knowing the mathematical details.


Asunto(s)
Infecciones por Adenoviridae/epidemiología , Adenoviridae/metabolismo , Queratoconjuntivitis/epidemiología , Queratoconjuntivitis/metabolismo , Queratoconjuntivitis/virología , Infecciones por Adenoviridae/virología , Adulto , Brotes de Enfermedades/prevención & control , Humanos , Persona de Mediana Edad , Modelos Biológicos , Modelos Teóricos , Oftalmología/métodos , Factores de Tiempo
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 2953-2956, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30441019

RESUMEN

The number of implantable bidirectional neural interfaces available for neuroscientific research applications is still limited, despite the rapidly increasing number of customized components. We previously reported on how to translate available components into "ready-to-use" wireless implantable systems utilizing components off-the-shelf (COTS). The aim of the present study was to verify the viability of a micro-electrocorticographic ($\mu $ECoG) device built by this approach. Functionality for both neural recording and stimulation was evaluated in an ovine animal model using acoustic stimuli and cortical electrical stimulation, respectively. We show that auditory evoked responses were reliably recorded in both time and frequency domain and present data that demonstrates the cortical electrical stimulation functionality. The successful recording of neuronal activity suggests that the device can compete with existing implantable systems as a neurotechnological research tool.


Asunto(s)
Encéfalo , Electrocorticografía , Animales , Potenciales Evocados Auditivos , Neurofisiología , Prótesis e Implantes , Ovinos
9.
J Clin Invest ; 96(3): 1520-6, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7544808

RESUMEN

Various immune mechanisms have been reported to contribute to the progressive destruction of Th cells in HIV-1-infected patients. Among these, complement mediated lysis of infected cells has been suggested. An increased sensitivity of lymphocytes from HIV-1-infected patients to lysis by monoclonal antibodies directed to MHC class I antigen and complement has been directly correlated with a decreased expression of the decay accelerating factor (CD55). It also has been reported that the expression of the membrane inhibitor of reactive lysis (CD59) is decreased during HIV-1 infection. We examined the effect of antibodies in the serum of HIV-1-positive individuals and normal human serum (NHS) as source of complement on several HIV-1-infected cell lines differing in their expression of CD55 and CD59. When HIV-1-infected target cells without membrane expression of CD55 and CD59 were used, a highly significant cytotoxic effect was observed in the presence of heat inactivated anti-HIV-1-positive sera and NHS, while heat-inactivated anti-HIV-1-negative sera and NHS were unable to induce cytolysis. Similar results were obtained using purified IgG isolated from HIV-1-positive sera and either NHS or guinea pig serum as source of complement. Lysis of HIV-1-infected cells correlated with expression of viral antigens on the cell surface. HIV-1-infected CD55 and CD59 positive target cells showed specific lysis, when the function of these molecules was abrogated by blocking antibodies to CD55 and CD59. The finding of anti-HIV-1-specific cytotoxic antibodies in sera from HIV-1-infected patients should be considered in the pathogenesis of the HIV-1-infection.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos , Antígenos CD/sangre , Proteínas del Sistema Complemento/inmunología , VIH-1 , Glicoproteínas de Membrana/sangre , Linfocitos T/inmunología , Síndrome de Inmunodeficiencia Adquirida/sangre , Anticuerpos Monoclonales , Linfocitos T CD4-Positivos/inmunología , Antígenos CD55 , Antígenos CD59 , Línea Celular , Proteínas Inactivadoras de Complemento , Citometría de Flujo , Humanos
10.
J Mol Biol ; 311(1): 1-7, 2001 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-11469853

RESUMEN

With the completion of the sequences of entire genomes, the need for functional characterisation of proteins and their domains is becoming acute. Conserved regions within proteins often share overlapping functions but despite this conservation may fulfil quite different tasks in different species. In this work, we investigated the cysteine-rich motif (C1 domain) of yeast protein kinase C (Pkc1p) as a model to establish a test system for domain function. C1 domains activate kinases through binding of either diacylglycerol and/or phosphatidylserine, as in many members of the protein kinase C (PKC) family, or by binding small GTPases, as in Raf kinase. In contrast to other members of the protein kinase C superfamily, Pkc1p of Saccharomyces cerevisiae is activated via binding of the small G-protein Rho1p to its C1 domain. We developed a system for domain shuffling to establish the function of C1 domains from human Raf kinase and rat PKC eta in yeast. Only the C1 domain from Raf kinase enabled the chimeric enzyme to bind Rho1p when substituted for the native yeast domain. Accordingly, a chimeric Pkc1p carrying the C1 from Raf kinase, but not that from PKC eta, was able to partially complement the phenotypes of a yeast pkc1 deletion mutant. We interpret these data as further evidence that interaction with a small GTPase is the main regulatory function of the C1 domain in yeast.


Asunto(s)
Cisteína/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Isoenzimas/química , Isoenzimas/metabolismo , Proteínas Quinasas Activadas por Mitógenos , Proteína Quinasa C/química , Proteína Quinasa C/metabolismo , Proteínas Proto-Oncogénicas c-raf/química , Proteínas Proto-Oncogénicas c-raf/metabolismo , Proteínas de Saccharomyces cerevisiae , Secuencias de Aminoácidos , Sustitución de Aminoácidos/genética , Animales , Cisteína/genética , Proteínas Fúngicas/genética , Humanos , Isoenzimas/genética , Mutación/genética , Fenotipo , Fosforilación , Proteína Quinasa C/genética , Proteínas Quinasas/metabolismo , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas c-raf/genética , Ratas , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Relación Estructura-Actividad , Técnicas del Sistema de Dos Híbridos , Proteínas de Unión al GTP rho/genética , Proteínas de Unión al GTP rho/metabolismo
11.
J Mol Biol ; 300(4): 743-58, 2000 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-10891267

RESUMEN

MAP kinases are essential components of signal transduction pathways in yeasts and higher eukaryotes. Here, we report on the isolation of the gene encoding the MAP kinase KlMpk1p by complementation of the respective Saccharomyces cerevisiae deletion mutant with a genomic library from Kluyveromyces lactis. Sequencing revealed the presence of an open reading frame capable of encoding a protein of 520 amino acid residues with a deduced molecular mass of 59.726 Da. The deduced protein sequence displayed a high degree of similarity to known MAP kinases from yeast to man, with an overall identity of 70 % to ScMpk1p. One-hybrid analysis demonstrated the presence of a cryptic transcriptional activation domain in the C-terminal part of the protein. Deletion of this sequence in ScMpk1p resulted in a reduced MAP kinase activity (measured by an indirect assay), an increased sensitivity towards caffeine and an increased resistance against Calcofluor white. Complete deletion mutants of Klmpk1 display an osmo-remedial phenotype on rich medium, but are capable of growth in the absence of osmotic stabilization on synthetic medium. As Scmpk1 deletion mutants, they are sensitive to cell surface destabilizing agents such as Calcofluor white and SDS, and growth is inhibited in the presence of 5 mM caffeine. Overexpression of KlMPK1 did not produce a growth defect in S. cerevisiae or in K. lactis.


Asunto(s)
Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Kluyveromyces/enzimología , Proteínas Quinasas Activadas por Mitógenos/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/enzimología , Secuencia de Aminoácidos , Bencenosulfonatos/farmacología , Cafeína/farmacología , Clonación Molecular , Proteínas Fúngicas/química , Prueba de Complementación Genética , Kluyveromyces/efectos de los fármacos , Kluyveromyces/genética , Kluyveromyces/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Proteínas Quinasas Activadas por Mitógenos/química , Datos de Secuencia Molecular , Concentración Osmolar , Fenotipo , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Alineación de Secuencia , Eliminación de Secuencia/genética , Dodecil Sulfato de Sodio/farmacología , Técnicas del Sistema de Dos Híbridos
12.
J Mol Biol ; 264(2): 279-301, 1996 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-8951377

RESUMEN

Treatment of rigor fibers of insect flight muscle (IFM) with AMPPNP at 23 degrees C causes a 70% drop in tension with little change in stiffness. In order to visualize the changes in crossbridge conformation and distribution that give rise to the mechanical response, we have produced three-dimensional reconstructions by tomography of both rigor and AMPPNP-treated muscle that do not average the repeating motifs of crossbridges, and thereby retain information on variability of crossbridge structure and distribution. Tomograms can be averaged when display of only the regular features is wanted. Tomograms of rigor IFM show double-headed lead and single-headed rear crossbridges. Tomograms of IFM treated with AMPPNP at 23 degrees C reveal many double-headed and some single-headed "lead" bridges but few crossbridges corresponding to the rear bridges of rigor. Instead, new non-rigor forms of variably angled crossbridges are found bound to actin sites not labeled with myosin heads in rigor. This indicates that the rear bridges of rigor have redistributed during the transition from rigor to the AMPPNP state, which could explain the maintenance of rigor stiffness despite the loss of tension. Comparison of in situ crossbridges in tomograms of rigor with atomic model of acto-S1, the complex formed by myosin subfragment 1 and actin, reveals that the regulatory domain of S1 would require significant bending and realignment to fit into both types of rigor crossbridges. The modifications are particularly significant for the rear bridges and suggest that differential strain in the regulatory domain of rear bridges may be the basis for their detachment and redistribution upon binding AMPPNP. Similar comparison using lead-type crossbridges in AMPPNP reveals departures from the rigor acto-S1 atomic model that include azimuthal straightening and a slight M-ward bending in the regulatory domain. Both the motor and regulatory domains of the new non-rigor crossbridges differ from those in the atomic model of acto-S1. A new crossbridge motif identified in AMPPNP-treated muscle consists of paired rigor-like and non-rigor crossbridges and suggests possible transitions in the myosin working stroke.


Asunto(s)
Adenosina Trifosfato/análogos & derivados , Adenilil Imidodifosfato/farmacología , Hemípteros/ultraestructura , Fibras Musculares Esqueléticas/ultraestructura , Músculo Esquelético/ultraestructura , Animales , Procesamiento de Imagen Asistido por Computador , Fibras Musculares Esqueléticas/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Subfragmentos de Miosina/metabolismo , Rigor Mortis , Temperatura
13.
Food Chem Toxicol ; 43(2): 307-14, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15621343

RESUMEN

Recent reports on sporadic cases of liver disorders (acute hepatitis, icterus, hepatocellular necrosis) after ingestion of dietary supplements based on hydro-alcoholic extracts from green tea leaves led to restrictions of the marketing of such products in certain countries of the EU. Since green tea is considered to exert a number of beneficial health effects, and, therefore, green tea products are widely used as dietary supplements, we were interested in the possible mechanism of hepatotoxicity of green tea extracts and in the components involved in such effects. Seven hours after seeding on collagen, rat hepatocytes in primary culture were treated with various hydro-alcoholic green tea extracts (two different native 80% ethanolic dry extracts and an 80% ethanolic dry extract cleared from lipophilic compounds). Cells were washed, and reduction of resazurin, used as a viability parameter monitoring intact mitochondrial function, was determined. It was found that all seven green tea extracts examined enhanced resazurin reduction significantly at a concentration range of 100-500 microg/ml medium, while a significant decrease was observed at 1-3mg/ml medium. Decreased levels were concomitant with abundant necrosis as observed by microscopic inspection of the cultures and with increased leakage of lactate dehydrogenase activity from the cells. In a separate series of experiments, the green tea constituents (-)-epicatechin, (-)-epigallocatechin-3-gallate, caffeine and theanine were tested at concentrations reflecting their levels in a typical green tea extract. Synthetic (+)-epigallocatechin (200 microM) was used for comparison. Cytotoxicity was found with (-)-epigallocatechin-3-gallate only. The concomitant addition of 0.25 mM ascorbate/0.05 mM alpha-tocopherol had no influence on cytotoxicity. In conclusion, our results suggest that high concentrations of green tea extract can exert acute toxicity in rat liver cells. (-)-Epigallocatechin-3-gallate seems to be a key constituent responsible for this effect. The relatively low bioavailability of catechins reported after oral exposure to green tea argues, however, against a causal role of these constituents in the reported liver disorders.


Asunto(s)
Catequina/análogos & derivados , Catequina/toxicidad , Hepatocitos/efectos de los fármacos , Extractos Vegetales/toxicidad , Té/química , Animales , Disponibilidad Biológica , Catequina/farmacocinética , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas , Hepatocitos/enzimología , Absorción Intestinal/efectos de los fármacos , L-Lactato Deshidrogenasa/metabolismo , Masculino , Oxazinas , Extractos Vegetales/farmacocinética , Ratas , Ratas Wistar , Xantenos
14.
Euro Surveill ; 10(6): 1-2, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29183474

RESUMEN

The threat posed by emerging and re-emerging communicable diseases and, more recently, by the intentional release of infectious agents in a susceptible population, has been receiving considerable attention at the national and international levels. Public health efforts to strengthen disease detection, surveillance and control have been intensified. However, clinicians and clinical microbiology laboratories play an important role in the early detection of disease, the identification of the putative agent, and notification of the appropriate authorities. To be effective in this role, laboratories must be specially prepared to handle viral agents safely, and need, among other things, the appropriate rapid and sensitive diagnostic tests. In 1998 the European Network for Diagnostics of "Imported" Viral Diseases (ENIVD) was established. ENIVD presently comprises, as permanent members, 44 expert laboratories in 21 European Union (EU) member states and 4 non-EU countries and is one of the networks on infectious diseases funded by the European Commission. ENIVD fulfils many of the important tasks required for the surveillance and control of imported, rare and emerging viral infections such as the exchange of expertise and the organisation of external quality assurance (EQA) programmes, both of which are needed to improve diagnostics. Here, we summarise the data generated by recent EQA activities focussed on the diagnostics of infections with hantavirus, dengue virus, filovirus, Lassa virus, orthopox virus and the SARS-coronavirus (SARS-CoV). These were carried out between 1999 and 2004 and involved 93 laboratories from 41 countries, including laboratories from additional countries outside of Europe. Particularly the EU-candidate countries and Eastern neighbouring countries will be invited to join the network in the near future. A public website is available at http://www.enivd.de.

15.
Euro Surveill ; 10(6): 102-6, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16077216

RESUMEN

The threat posed by emerging and re-emerging communicable diseases and, more recently, by the intentional release of infectious agents in a susceptible population, has been receiving considerable attention at the national and international levels. Public health efforts to strengthen disease detection, surveillance and control have been intensified. However, clinicians and clinical microbiology laboratories play an important role in the early detection of disease, the identification of the putative agent, and notification of the appropriate authorities. To be effective in this role, laboratories must be specially prepared to handle viral agents safely, and need, among other things, the appropriate rapid and sensitive diagnostic tests. In 1998 the European Network for Diagnostics of 'Imported' Viral Diseases (ENIVD) was established. ENIVD presently comprises, as permanent members, 44 expert laboratories in 21 European Union (EU) member states and 4 non-EU countries and is one of the networks on infectious diseases funded by the European Commission. ENIVD fulfils many of the important tasks required for the surveillance and control of imported, rare and emerging viral infections such as the exchange of expertise and the organisation of external quality assurance (EQA) programmes, both of which are needed to improve diagnostics. Here, we summarise the data generated by recent EQA activities focussed on the diagnostics of infections with hantavirus, dengue virus, filovirus, Lassa virus, orthopox virus and the SARS-coronavirus (SARS-CoV). These were carried out between 1999 and 2004 and involved 93 laboratories from 41 countries, including laboratories from additional countries outside of Europe. Particularly the EU-candidate countries and Eastern neighbouring countries will be invited to join the network in the near future. A public website is available at http://www.enivd.de.


Asunto(s)
Bioterrorismo/prevención & control , Defensa Civil/métodos , Vigilancia de la Población/métodos , Garantía de la Calidad de Atención de Salud/métodos , Virosis/diagnóstico , Virosis/epidemiología , Defensa Civil/normas , Europa (Continente)/epidemiología , Humanos , Garantía de la Calidad de Atención de Salud/normas , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
16.
Clin Drug Investig ; 25(10): 651-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-17532710

RESUMEN

OBJECTIVE: The efficacy and tolerability of acarbose were examined in a postmarketing surveillance study of 27 803 patients with diabetes mellitus (26 044 were diagnosed as having type 2 diabetes) over a 12-week treatment period. PATIENTS AND M ethods: Overall efficacy data were reported for type 1 and type 2 diabetes, and a detailed data analysis was conducted for patients with type 2 diabetes. Tolerability was described for the total group. Of the type 2 diabetes patients, 37.6% were treated with diet only; 44.2% were additionally treated with sulphonylureas; 6.3% with metformin or metformin plus sulphonylurea; and 11.6% with insulin alone or in combination with oral treatment. The frequency of two or more concomitant diseases was 45.8% for all type 2 diabetes patients, and 62.4% in elderly patients (age >/=70 years). RESULTS: In patients with type 2 diabetes, acarbose administration in addition to the existing treatment resulted in reductions in mean blood glucose levels (fasting 50 mg/dL, 1h post-prandial [pp] 60 mg/dL, 2h pp 56 mg/dL), glycosylated haemoglobin (HbA(1c) 1.3%; HbA(1) 1.6%) and bodyweight (1.5 kg). Results for type 1 diabetes patients were similar. No clinically relevant influence of age, body mass index or number of concomitant diseases on the results could be observed. Tolerability was good: 83% of patients had no adverse events, 13.7% reported flatulence, and 2.2% had at least one occurrence of diarrhoea. Hypoglycaemia was found in 0.07% of patients, mainly in combination with metformin or insulin. Tolerability was independent of patients' age. Laboratory investigations gave no indication of other adverse events. CONCLUSION: This postmarketing surveillance study documents the therapeutic benefit and good tolerability and compliance of acarbose as mono- and combination therapy, even in elderly and multimorbid patients.

17.
Mol Immunol ; 20(7): 719-26, 1983 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6193418

RESUMEN

The five synthetic antigenic sites of sperm whale myoglobin were used in their free form (i.e. not coupled to any carrier) to immunize separate groups of BALB/cByJ mice. The synthetic peptides corresponded to: site 1, residues 15-22; site 2, residues 56-62; site 3, residues 94-99; site 4, residues 113-119; site 5, residues 145-151. Serum samples obtained from each group of mice contained antibodies that bound specifically to myoglobin and exclusively to the immunizing antigenic site. Monoclonal antibodies to each of the five antigenic sites were subsequently obtained by hybridizing Fa/O mouse myeloma cells with spleen cells derived from each group of mice. These monoclonal antibodies were either IgM(kappa) or IgGl(kappa). They expressed the same isotypes as the antigen specific serum antibodies produced by the mice whose spleen cells were used for hybridization. Solid phase radioimmunoassay studies also indicated that each monoclonal antibody, like the immune serum of the parent animals, bound specifically to myoglobin and exclusively to the synthetic peptide used as an immunogen. These results suggested that the hybridoma antibodies expressed submolecular binding specificities that were the result of peptide immunization rather than hybrid selection. This strongly supports our previous findings that it is possible to produce monoclonal antibodies with preselected submolecular binding specificities to continuous protein determinants by the techniques of somatic cell hybridization when the corresponding free synthetic determinants are used as immunogens.


Asunto(s)
Anticuerpos Monoclonales/biosíntesis , Especificidad de Anticuerpos , Mioglobina/inmunología , Animales , Anticuerpos Monoclonales/clasificación , Anticuerpos Monoclonales/inmunología , Epítopos/inmunología , Femenino , Hibridomas/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Radioinmunoensayo , Ballenas
18.
Mol Immunol ; 19(12): 1699-1702, 1982 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6186911

RESUMEN

Two monoclonal antibodies with pre-selected submolecular binding specificities to sperm whale myoglobin (Mb) were obtained by hybridizing Fa/0 mouse myeloma cells with spleen cells derived from mice which had been immunized with free (not coupled to any carrier) Mb synthetic peptides 132-153 or 145-151 (antigenic site 5). Both monoclonal antibodies were IgG1 (k). Their homogeneity was confirmed by analytical isoelectric focusing electrophoresis. According to competitive inhibition studies in which Mb, the five synthetic antigenic sites of Mb, Mb peptide 132-153, bovine serum albumin (BSA), and lysozyme were used as inhibitors, the binding specificities of both monoclonal antibodies were restricted to determinants present in the peptides used for immunizations. The results of direct binding studies confirmed this conclusion and suggested that monoclonal antibodies with pre-selected submolecular binding specificities can be readily obtained by the techniques of somatic cell hybridization when the corresponding free synthetic determinants are used as immunogens.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Especificidad de Anticuerpos , Epítopos/inmunología , Mioglobina/inmunología , Animales , Unión Competitiva , Femenino , Focalización Isoeléctrica , Masculino , Ratones , Ratones Endogámicos BALB C , Péptidos/inmunología , Ballenas
19.
Mol Immunol ; 20(5): 567-70, 1983 May.
Artículo en Inglés | MEDLINE | ID: mdl-6192328

RESUMEN

Previous studies have resulted in the determination of the entire structure of myoglobin. The present work was carried out to investigate the antigenicity of the synthetic antigenic sites and other surface peptides of Mb in their free form (i.e. without coupling to a carrier). Site 1 (peptide 15-22), site 2 (peptide 56-62), site 3 (peptide 94-100), site 4 (peptide 113-120), site 5 (peptide 145-151) and two surface peptides, peptide 1-6 and peptide 121-127, were injected in complete Freund's adjuvant into Balb/c mice. Radioimmune antibody binding studies showed that immunization with each of these peptides, in their free form, resulted in the formation of antibodies that bound specifically to Mb and to the immunizing peptide. The advantage and significance of these findings are discussed.


Asunto(s)
Formación de Anticuerpos , Epítopos/inmunología , Mioglobina/inmunología , Péptidos/inmunología , Animales , Especificidad de Anticuerpos , Sueros Inmunes/inmunología , Inmunización , Ratones , Ratones Endogámicos BALB C
20.
Neotrop Entomol ; 44(2): 140-52, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26013132

RESUMEN

The species composition and the relative abundance of species in an insect community can vary in time and space for many reasons, including climatic variables and habitat preferences. Drosophilids were collected each quarter from April 2011 to April 2012 (five collections in all) in a natural area of the Pampa biome, considering three environments: open field, forest edge and the interior of forest patches. Kruskal-Wallis and chi-square tests were used to examine the effects of temporal and spatial components on the drosophilid assemblage. Four diversity measures: S obs , S rar , H' and E var were used to evaluate the community structure. A total of 7164 drosophilids belonging to 51 species were collected. The interaction of species in each environment varied among sampling periods. The abundance of both Neotropical and exotic species was affected by temporal and spatial components. The species of the D. repleta group were predominantly more abundant in the open field, but they migrated to the forest patches during periods of thermal stress. Generally, diversity was greatest in the interior of forest patches. Nevertheless, temporal components appear to be the predominant environmental determinant of the characteristics of the drosophilid community of the Pampas. Furthermore, the forest patches appear to act as a center of recolonization, reinforcing their importance in the maintenance of biodiversity in the Pampas; this function will be even more important in the future, when the temperatures will, most likely, be higher.


Asunto(s)
Distribución Animal , Drosophilidae , Animales , Brasil , Clima , Ecosistema
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