Thrombophilic disorders in children with cerebral infarction.
Explore the source record for details and available documents.
Adolescent↗
Biomedical subjects
S Becker
Publications and source records attributed to S Becker.
Interactions of Marburg virus nucleocapsid proteins.
In this study, the components of Marburg virus nucleocapsid complex were determined, and interactions between the compounds were investigated. Using salt dissociation of isolated virions, four proteins (NP, VP35, VP30, and L) remained attached to the core complex. Same proteins were detected intracellularly to be localized in MBGV-induced inclusion bodies, which are presumed to represent areas of nucleocapsid formation. To investigate interactions between the four proteins, immunofluorescence analysis of coexpressed proteins was carried out. Complexes between NP-VP35 and NP-VP30 were formed, which was demonstrated by redistribution of VP35 and VP30 into NP-induced inclusion bodies. Furthermore, complexes between L and VP35 were detected by coimmunoprecipitation. Using deletion mutants of L, the binding site of VP35 on L could be restricted to the N-terminal 530 amino-acid residues. Coexpression of NP, VP35, and L led to the formation of a triple complex where VP35 linked NP and L. The detected complexes are presumed to represent the key components of the MBGV transcription and replication machinery.
Animals↗
The CHORUS database on patient clinical care--and interview with Stephen Becker, M.D. Interview by John S. James.
Explore the source record for details and available documents.
Data Collection↗
Correction of respiratory burst activity in X-linked chronic granulomatous cells to therapeutically relevant levels after gene transfer into bone marrow CD34+ cells.
Chronic granulomatous disease (CGD) is a disorder of the lymphohematopoietic system, whereby phagocytes of affected patients are unable to kill microorganisms. CGD is caused by a functional defect in the phagocytic nicotinamide adenine dinucleotide phosphatase (NADPH) oxidase (phox) enzyme complex, leading to a lack of microbicidal metabolites. As a therapeutic approach toward the predominant X-linked form of CGD, we have developed a bicistronic retroviral vector containing the coding sequences of gp91-phox and a cytoplasmically truncated version of the human low-affinity receptor for nerve growth factor (deltaLNGFR). Full reconstitution of superoxide-generating activity was achieved with this vector in a gp91-phox-deficient cell line. Using an optimized gene transfer protocol, up to 85% of the CD34+ cells obtained from the bone marrow of X-CGD patients were transduced. CD15+ cells differentiated in vitro from transduced X-CGD CD34+ cells showed correction of NADPH oxidase activity to 45-52% of normal levels whereas deltaLNGFR expression was found in 40-67% of the CD15+ cells. Moreover, immunoblots prepared from extracts of transduced CD15+ cells revealed gp91-phox protein levels similar to those found in neutrophils derived from normal CD34+ cells. Taking into consideration that superoxide production in only 5 to 10% of wild-type neutrophils is sufficient to protect X-CGD heterozygotes from serious infections, the results achieved in this study shows that for X-CGD patients a curative approach based on the genetic modification of hematopoietic stem/progenitor cells is feasible.
Antigens, CD34↗
Respiratory syncytial virus-induced RANTES production from human bronchial epithelial cells is dependent on nuclear factor-kappa B nuclear binding and is inhibited by adenovirus-mediated expression of inhibitor of kappa B alpha.
Respiratory syncytial virus (RSV) infection is an important cause of lower respiratory tract illness, the severity of which may be partly due to cellular recruitment. RSV infection activates chemokine secretion from airway epithelial cells by largely unknown mechanisms. We investigated the regulation of RSV-induced activation of the chemokine RANTES in the bronchial epithelial cell line BEAS-2B and primary normal human tracheobronchial epithelial cultures. RANTES protein and mRNA were detected at 24 h and up until 72 h from cultures of BEAS-2B infected with replicating virus, but not with UV-inactivated RSV. RSV infection of BEAS-2B or normal human tracheobronchial epithelial cells stimulated NF-kappa B translocation to the nucleus and binding to the RANTES-specific kappa B-binding sequences within 2 h, with levels peaking at 24 h. Supershift assays indicated that binding was due to p50/p65 heterodimers. BEAS-2B cells were transfected with a replication-deficient adenoviral vector, expressing a mutated, nondegradable form of I kappa B alpha. I kappa B alpha overexpression specifically blocked NF-kappa B translocation and inhibited mRNA accumulation and secretion of RANTES induced by RSV or TNF-alpha plus IFN-gamma. Adenoviral transfection did not interfere with RSV replication or significantly induce apoptosis. Further, a control adenovirus, expressing the beta-galactosidase gene, did not alter cellular functions. Thus, NF-kappa B nuclear translocation is a critical step in RSV induction of RANTES secretion. Elucidating the mechanisms of cellular activation by RSV and targeting specific areas may lead to novel therapeutic approaches in the treatment of RSV.
Adenoviridae↗
Three-dimensional structure of the Stat3beta homodimer bound to DNA.
STAT proteins are a family of eukaryotic transcription factors that mediate the response to a large number of cytokines and growth factors. Upon activation by cell-surface receptors or their associated kinases, STAT proteins dimerize, translocate to the nucleus and bind to specific promoter sequences on their target genes. Here we report the first crystal structure of a STAT protein bound to its DNA recognition site at 2.25 A resolution. The structure provides insight into the various steps by which STAT proteins deliver a response signal directly from the cell membrane to their target genes in the nucleus.
Amino Acid Sequence↗
Sarcolipin regulates the activity of SERCA1, the fast-twitch skeletal muscle sarcoplasmic reticulum Ca2+-ATPase.
The 31-amino acid proteolipid, sarcolipin (SLN), is associated with the fast-twitch skeletal muscle sarcoplasmic reticulum Ca2+-ATPase (SERCA1). Constructs of human and rabbit SLN and of rabbit SLN with the FLAG epitope at its N terminus (NF-SLN) or its C terminus (SLN-FC) were coexpressed with SERCA1 in HEK-293 T-cells. Immunohistochemistry was used to demonstrate colocalization of NF-SLN and SERCA1 in the endoplasmic reticulum membrane and to demonstrate the cytosolic orientation of the N terminus of SLN. Coexpression of native rabbit SLN or NF-SLN with SERCA1 decreased the apparent affinity of SERCA1 for Ca2+ but stimulated maximal Ca2+ uptake rates (Vmax). The N terminus of SLN is not well conserved among species, and the addition of an N-terminal FLAG epitope did not alter SLN function. Anti-FLAG antibody reversed both the inhibition of Ca2+ uptake by NF-SLN at low Ca2+ concentrations and the stimulatory effect of NF-SLN on Vmax. Addition of the FLAG epitope to the highly conserved C terminus decreased the apparent affinity of SERCA1 for Ca2+ relative to native SLN and decreased Vmax significantly. Mutations in the C-terminal domain showed that this sequence is critical for SLN function. Mutational analysis of the transmembrane helix, together with the additive regulatory effects of coexpression of both SLN and phospholamban (PLN) with SERCA1, provided evidence for different mechanisms of interaction of SLN and PLN with SERCA molecules. Ca2+ uptake rates in sarcoplasmic reticulum vesicles, isolated from rabbit fast-twitch muscle (tibialis anterior) subjected to chronic low frequency stimulation, were reduced by approximately 40% in 3- and 4-day stimulated muscle, with a marginal increase in apparent affinity of SERCA1 for Ca2+. SERCA1 mRNA and protein levels were unaltered after stimulation. In contrast, SLN mRNA was decreased by 15%, and SLN protein was reduced by 40%. Reduced SLN expression could explain the decrease in SERCA1 activity observed in these muscles and might represent an early functional adaptation to chronic low frequency stimulation.
Amino Acid Sequence↗
Rapid reversed-phase high-performance liquid chromatography method for quantitation, at high pH, of the recombinant apolipoprotein A-IMilano in Escherichia coli fermentation broth.
An automated reversed-phase high-performance liquid chromatography method for quantitative determination of recombinant apolipoprotein A-IMilano (r-Apo A-IM) in E. coli fermentation broth has been developed and evaluated. The use of a unique matrix (Poros IIR/H) makes it possible to achieve rapid separation and good resolution at high pH. The r-Apo A-IM-containing fraction is well separated from other proteins allowing a reliable quantification. The automation and high sample throughput of this method makes it very useful for routine determination of r-Apo A-IM in fermentation broth and in eluates from the various purfication steps. With suitable modifications and adaptions this method is likely to be useful for similar rapid analytical determination of recombinant proteins in complex solutions.
Apolipoprotein A-I↗
Primary non-Hodgkin lymphoma of the spine.
Primary non-Hodgkin lymphoma (PHL) occurs very rarely in bone. We report a case of a 63-year-old patient with PHL of the spine and an unusual postoperative complication leading to the development of a perforation of the transverse colon. After right hemicolectomy the patient recovered fully and was further treated with chemo- and radiotherapy. We emphasise the importance of an immunohistochemical analysis to exclude misdiagnosis.
Antineoplastic Combined Chemotherapy Protocols↗
Infant leukemia in Belarus after the Chernobyl accident.
Petridou et al. [1] have reported an increase in infant leukemia in Greek children born between 1/7/86 and 31/12/87 and have linked this increase to in utero radiation exposure due to the Chernobyl accident. Subsequently, Michaelis et al. [2] have reported a similar trend for Germany but found that it was not correlated to the levels of contamination. For Belarus, which was much more severely affected, a similar but much weaker trend is found.
Cohort Studies↗
Reproductive health care: services oriented to couples.
Historically, the combination of women's rights to care, population concerns and the development of female-oriented contraceptive methods resulted in family planning programs focusing on women's contraceptive needs and little else. The 1994 United Nations Population Conference in Cairo called for an expansion of programs to cover reproductive health in its broadest interpretation. As this concept has developed and been put into practice it has become evident that a key element in reproductive health services should be the inclusion of the sexually active couple.
Adult↗
The effect of fluticasone propionate on respiratory syncytial virus-induced chemokine release by a human bronchial epithelial cell line.
Respiratory syncytial virus (RSV) is an important cause of bronchiolitis in infants, is an important trigger of asthma exacerbation, and stimulates chemokine production by human respiratory epithelial cells in vitro. We tested the effect of the corticosteroid fluticasone propionate (FP) on RSV-stimulated production of the chemokines interleukin 8 (IL-8) and RANTES (regulated upon activation, normal T cell expressed and secreted) by a human bronchial epithelial cell line, BEAS-2B. Confluent BEAS-2B cultures were inoculated with RSV at approximately 1 plaque-forming unit/cell, and media were collected at 24 h intervals. Concentrations of IL-8 and RANTES were measured in supernatants using ELISA. The effect of FP at varying concentrations on RSV-induced chemokine release was determined. RSV stimulated increased release of both IL-8 and RANTES, particularly at 24-48 h after virus inoculation. Significant but incomplete inhibition of RSV-stimulated increases for both chemokines was found when cultures were treated with FP at > or = 10(-8) M (for IL-8) or > or = 10(-7) M (for RANTES). There was no significant effect of FP on release of RSV itself from infected BEAS-2B cells. We conclude that a possible mechanism for the efficacy of inhaled corticosteroids in reducing the frequency or severity of asthma exacerbations is inhibition of virus-induced chemokine production by airway cells.
Androstadienes↗
Contextual determinants of maternal mortality in rural Pakistan.
Maternal mortality is high in Pakistan, particularly in the rural areas which have poor access to health services. We investigated the risk factors associated with maternal mortality in sixteen rural districts of Balochistan and the North-West Frontier (NWFP) provinces of Pakistan. We designed a nested case-control study comprising 261 cases (maternal deaths reported during last five years) and 9135 controls (women who survived a pregnancy during last five years). Using contextual analysis, we estimated the interactions between the biological risk factors of maternal mortality and the district-level indicators of health services. Women under 19 or over 39 yr of age, those having their first birth, and those having a previous history of fetal loss were at greater risk of maternal death. Staffing patterns of peripheral health facilities in the district and accessibility of essential obstetric care (EOC) were significantly associated with maternal mortality. These indicators also modified the effects of the biological risk factors of maternal mortality. For example, nulliparous women living in the under-served districts were at greater risk than those living in the better-served districts. Our results are consistent with several studies which have pointed out the role of health services in the causation of maternal mortality. Many such studies have implicated distance to hospital (an indicator of access to EOC) and lack of prenatal care as major determinants of maternal mortality. We conclude that better staffing of peripheral health facilities and improved access to EOC could reduce the risk of maternal mortality among women in rural Balochistan and the NWFP.
Adolescent↗
Cell-specific differences in the susceptibility of potential cellular targets of human origin derived from blood and lung following treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
The induction of cytochrome P4501A (CYP1A1) enzyme activity is one of the best-studied direct effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds and has been shown to be a sensitive biomarker of exposure to polycyclic aromatic hydrocarbons (PAH) in different experimental animal species as well as in humans. TCDD has also been shown to modulate cytokine gene expression in human keratinocytes, including IL-1 beta, TGF-alpha and TFG-beta 2. In the present studies, the aim was to determine whether different cellular targets of human origin differed in susceptibility to TCDD as measured by CYP1A1 activity and mRNA expression, and whether cytokine gene induction/suppression correlated with TCDD susceptibility. Human airway epithelial cells, alveolar macrophages (AM), peripheral blood monocytes and lymphocytes (PBL) were exposed to 10(-10)-10(-7) mol/L TCDD. CYP1A1 enzyme activity was determined by ethoxyresorufin-O-deethylase (EROD) activity, mRNA expression of CYP1A1 was measured by semiquantitative PCR assay. The secretion and/or gene expression of specific cytokines, including IL-6, IL-8, and IL-1 beta were also examined. Overall, there was a clear correlation between TCDD-induced enzyme activity and CYP1A1 mRNA levels, which were dose-dependently increased in the bronchoepithelial cells and PBL. The human airway epithelial cells (BEAS-S6 cell line and primary cells) appeared to be the most inducible cellular target, with up to 50-fold increases at 10(-8) mol/L TCDD with an EC50 of 3 x 10(-11) mol/L TCDD. The pokeweed mitogen-activated peripheral blood lymphocytes revealed approximately 5-fold less capacity in CYP1A1 activity, with high interindividual variabilities (EC50 3 x 10(-9) mol/L TCDD). In contrast, CYP1A1 enzyme activity in both AM and purified peripheral blood monocytes, which were costimulated with LPS and/or GM-CSF, could not be detected. CYP1A1 mRNA levels, however, were detectable and only marginally enhanced in response to TCDD. The ability of all these cells to express and produce the proinflammatory cytokines IL-6 and IL-8 was neither enhanced nor impaired by TCDD. These results indicate that cell types found in human lung and peripheral blood vary in susceptibility to TCDD, with the lung epithelium being highly susceptible and the alveolar macrophage being nonsusceptible. However, expression and production of specific cytokines such as IL-6 and IL-8, which may potentiate inflammatory processes and/or work as mitogens, does not appear to be influenced by TCDD.
Adolescent↗
[Standards for treatment and expert opinion on transsexuals. The German Society for Sexual Research, The Academy of Sexual medicine and the Society for Sexual Science].
Over the last two-and-a-half years a committee of experts, consisting of members of the three leading German sexology associations, developed guidelines for treating and assessing transsexuals. Their purpose is to improve the care for patients with sex identity disorders and to ensure that such care is of uniform quality to avoid erroneous decisions to the disadvantage of those affected. The guidelines are set out in full.
Diagnosis, Differential↗
Characterisation of crude oils by carbon and sulphur isotope ratio measurements as a tool for pollution control.
The potential of carbon and sulphur isotope ratios to group crude oils with respect to their origin was investigated. Sample selection was based on the actual crude oil imports to Germany. Analysed crude oils from Algeria, the Community of Independent States (CIS), Middle East, Nigeria, the North Sea and Venezuela make up over 86% of the German crude oil imports. The oil as received was deasphalted and the maltene fraction was separated by MPLC into saturated, aromatic and polar fractions. Due to overlapping areas, it is not possible to group the crude oils by their delta 13C values alone. A complete grouping of the crude oils with respect to their origin can only be achieved by the combined use of delta 13C and delta 34S of crude oils, and isotope type-curves. In some cases isotope type-curves enable differentiation between different oil fields of the same geographical origin. In order to determine the post-spill changes of delta 13C values, an experimental spill of crude oil was studied over a period of seven weeks in an outdoor aquarium containing pond water. The delta 13C measurements of crude oil fractions showed changes up to 1.1/1000 during the oil spill simulation. The delta 13C values of the polar fraction exhibited the smallest change, with a variation of 0.3/1000, and are therefore especially useful for the characterisation of crude oil spills.
Carbon Isotopes↗
Seasonal patterns of deaths in Matlab, Bangladesh.
BACKGROUND: Deaths exhibit a seasonal pattern in most parts of the world. Analyses of deaths for the years 1972-1974 from the vital registration system of Matlab, Bangladesh, published in this journal 17 years ago, showed sinusoidal seasonal patterns. As death rates have declined in other nations, the seasonal pattern is attenuated. Death rates have declined substantially in Bangladesh in the past two decades. Thus, the present study examines monthly counts of deaths from Matlab data for a period 15 years later and tests the hypothesis of a decrease or shift in seasonality over time. METHODS: Trigonometric regression models were fit to monthly data by age and cause of death from the Matlab vital registration system for the years 1982-1990. A total of 20,328 death records were available for analyses. RESULTS: In the recent period significant sinusoidal seasonal patterns are found in all but one of the age and cause of death groups. Total deaths peak in the winter as do neonatal deaths but post-neonatal and child deaths are maximum in April and July respectively. Among cause groups, injury deaths (mostly attributed to drowning) show the greatest seasonal swing. The time of peak has only shifted for one age group--neonates--since the 1972-1974 period. The magnitude of the seasonal swing has declined significantly only for the neonatal age group and injury cause of death group. CONCLUSION: Marked seasonal patterns of deaths persist in the Matlab area of Bangladesh even as the level of mortality has declined.
Adolescent↗
Three of the four nucleocapsid proteins of Marburg virus, NP, VP35, and L, are sufficient to mediate replication and transcription of Marburg virus-specific monocistronic minigenomes.
This paper describes the first reconstituted replication system established for a member of the Filoviridae, Marburg virus (MBGV). MBGV minigenomes containing the leader and trailer regions of the MBGV genome and the chloramphenicol acetyltransferase (CAT) gene were constructed. In MBGV-infected cells, these minigenomes were replicated and encapsidated and could be passaged. Unlike most other members of the order Mononegavirales, filoviruses possess four proteins presumed to be components of the nucleocapsid (NP, VP35, VP30, and L). To determine the protein requirements for replication and transcription, a reverse genetic system was established for MBGV based on the vaccinia virus T7 expression system. Northern blot analysis of viral RNA revealed that three nucleocapsid proteins (NP, VP35, and L) were essential and sufficient for transcription as well as replication and encapsidation. These data indicate that VP35, rather than VP30, is the functional homologue of rhabdo- and paramyxovirus P proteins. The reconstituted replication system was profoundly affected by the NP-to-VP35 expression ratio. To investigate whether CAT gene expression was achieved entirely by mRNA or in part by full-length plus-strand minigenomes, a copy-back minireplicon containing the CAT gene but lacking MBGV-specific transcriptional start sites was employed in the artificial replication system. This construct was replicated without accompanying CAT activity. It was concluded that the CAT activity reflected MBGV-specific transcription and not replication.
Animals↗