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Biomedical subjects

J Zupan

Publications and source records attributed to J Zupan.

At least 19 recordsLinked to original sources
PubMed2004

Topical umbilical cord care at birth.

BACKGROUND: Umbilical cord infection caused many neonatal deaths before aseptic techniques were used. OBJECTIVES: To assess the effects of topical cord care in preventing cord infection, illness and death. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register (September 2003) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003). We also contacted experts in the field. SELECTION CRITERIA: Randomized and quasi-randomized trials of topical cord care compared with no topical care, and comparisons between different forms of care. DATA COLLECTION AND ANALYSIS: Two reviewers assessed trial quality and extracted data. MAIN RESULTS: Twenty-one studies (8959 participants) were included, the majority of which were from high-income countries. No systemic infections or deaths were observed in any of the studies reviewed. No difference was demonstrated between cords treated with antiseptics compared with dry cord care or placebo. There was a trend to reduced colonization with antibiotics compared to topical antiseptics and no treatment. Antiseptics prolonged the time to cord separation. Use of antiseptics was associated with a reduction in maternal concern about the cord. REVIEWERS' CONCLUSIONS: Good trials in low-income settings are warranted. In high-income settings, there is limited research which has not shown an advantage of antibiotics or antiseptics over simply keeping the cord clean. Quality of evidence is low.

Anti-Bacterial Agents↗
PubMed2004

Prediction of selectivity of alpha1-adrenergic antagonists by counterpropagation neural network (CP-ANN).

A quantitative structure-selectivity relationships of series of structurally diverse alpha1-adrenergic antagonists was performed by using counter-propagation neural network (CP-ANN). The theoretical molecular descriptors have been calculated and selected using CODESSA program. The results obtained for a highly non-congeneric set of molecules have confirmed the potential of use of CP-ANN approach in prediction of relative activity (selectivity) of alpha1-adrenergic antagonists.

Adrenergic alpha-Antagonists↗
PubMed2004

Highly compact 2D graphical representation of DNA sequences.

Most 2D graphical representations of primary DNA sequences, while offering visual geometrical patterns for depicting sequences, do require considerable space if enough details of such representations are to be visible. In this contribution, we consider a highly compact graphical representation of DNA, which allows visual inspection and numerical characterization of DNA sequences having a large number of nucleic acid bases. The approach is illustrated on the DNA sequences of the first exon of human beta-globin. The same graphical approach not only allows one to depict differences in composition within a single DNA, but makes possible graphical representation of protein sequences, which have hitherto evaded similar 2D visual representations.

Computer Graphics↗
PubMed2003

Perinatal mortality and morbidity in developing countries. A global view.

Global perinatal mortality figures show that of the 132 million births per year, there are between 6 and 7 million perinatal deaths. While 90% of these births are in less developed countries, perinatal deaths take 98% of the global share. These statistics show on average the rates as they were in England during the 1930s. The most common recorded medical causes of perinatal deaths are also similar in the less developed countries, and the common denominators are early childbearing, poor maternal health and above all, the lack of appropriate and quality services. Although life-saving practices for most infants have been known for decades, currently a third of mothers still have no access to services during pregnancy, and almost half do not have access to services for childbirth. There are enormous variations both among and within countries. It takes innovation to find the best fit between the needs of women and infants and resources. A health worker with excellent knowledge and skills is the key resource and the best investment. The cost is moderate, and the investment pays a high dividend in improved health of both the mother and her baby, and better health for the next generation at lower cost.

Adult↗
PubMed2002

Application of a Kohonen neural network to the analysis of data regarding the alkylation of toluene with methanol catalyzed by ZSM-5 type zeolites.

para-Xylene is widely used in chemical industry. It can be synthesized by alkylation of toluene with methanol using zeolite ZSM-5 as catalyst. The proportion of para-xylene, among its other isomers and other reaction byproducts, depends on the reaction conditions. As this process still remains largely empirical, we attempted to build a theoretical model able to predict the para-xylene yield under specific reaction conditions. We have consequently collected data regarding this reaction from the literature and exploited the potency of a particular artificial neural network (ANN), the counter-propagation ANN based on the Kohonen technique. The results show that such an approach is suitable to establish a predictive model of the yield in para-xylene on the basis of reaction parameters. The quality of the model could be further improved by considering a larger valuable data set, e.g. including experiments characterized by a low yield in para-xylene.

Journal Article↗
PubMed2002

Novel matrix invariants for characterization of changes of proteomics maps.

Previous studies on mathematical characterization of proteomics maps by sets of map invariants were based on the construction of a set of distance-related matrices obtained by matrix multiplication of a single matrix by itself. Here we consider an alternative characterization of proteomics maps based on a set of matrices characterizing local features of an embedded zigzag curve over the map. It is shown that novel invariants can well characterize proteomics maps. Advantages of the novel approach are discussed.

Models, Theoretical↗
PubMed2001

Computer simulation of ion chromatography separation: an algorithm enabling continuous monitoring of anion distribution on an ion-exchange chromatography column.

A computer algorithm for the calculation of ion chromatography separation is presented. It is based on the calculation of equilibrium concentrations of present analyte in discrete column segments. The continuous column is treated as a number of discrete cells or segments where the equilibration process between the stationary phase and the eluent is simulated. The ion-exchange equilibration process is supposed to be instantaneous and quantitative. The continuous flow of the eluent is rendered by discrete transfers. The size of each transfer of the eluent corresponds to a portion of the volume contained in one column segment. The equilibrium calculations in all column segments are repeated for each transfer of the eluent, through all the stages of the chromatographic process. The distribution of the analytes between the stationary phase and the eluent can be monitored at any step and in any column segment which means that the described algorithm provides the spatial and time concentration profiles. The simulated chromatogram is acquired as a time-concentration profile in the last column segment. The obtained chromatograms are in good agreement with the experimental ones. The distribution of ions between the stationary phase and the eluent in the early stages of the ion chromatographic process can thus be studied with confidence.

Algorithms↗
PubMed2000

Viscosity prediction of lipophilic semisolid emulsion systems by neural network modelling.

Previously published data (Gasperlin et al., 1998) on viscoelastic behaviour of lipophilic semisolid emulsion systems and the prediction of their physical stability by neural network modelling are analysed in further detail. Most attention has been paid to viscosity, which with storage (G') and loss modulus (G"), is one of the most important rheological parameters influenced by structure. Complex dynamic viscosity (eta*) was measured by oscillatory rheometry. The viscosity dependence of the lipophilic semisolid emulsions on the ratio of the particular components was defined by the neural network (error back-propagation algorithm), linear and incomplete polynomial models of higher orders. Polynomial models were used to complement the neural network model and to determine the relationship between variables. Since the viscosity was expressed in the whole measured frequency range, modelling was more complex and indirect modelling was introduced. The determined models were tested and the results confirm their usefulness for the explanation and prediction of the rheological characteristics of emulsion systems. The trained and tested neural network model proved to be a highly effective and applicable tool for predicting the viscosity of a lipophilic semisolid emulsion system of given composition.

Emulsions↗
PubMed2000

Topical umbilical cord care at birth.

BACKGROUND: Umbilical cord infection caused many neonatal deaths before aseptic techniques were used. OBJECTIVES: The objective of this review was to assess the effects of topical cord care in preventing cord infection, illness and death. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register (Cochrane Library issue 4, 1997) and Medline. We also contacted experts in the field. SELECTION CRITERIA: Randomised and quasi-randomised trials of topical cord care compared with no routine care, and comparisons between different forms of care. DATA COLLECTION AND ANALYSIS: Two reviewers assessed trial quality and extracted data. MAIN RESULTS: Ten studies were included, all from developed countries. No systemic infections or deaths were observed in any of the studies reviewed. Cord and other skin infections within six weeks of observation were not affected by use of antiseptics. There was a trend to reduced colonization with antibiotics compared to antiseptics and no treatment. Antiseptics prolonged the time to cord separation. Use of antiseptics was associated with a reduction in maternal concern about the cord. REVIEWER'S CONCLUSIONS: Simply keeping the cord clean appears to be as effective and safe as using antibiotics or antiseptics.

Anti-Bacterial Agents↗
PubMed2000

The N- and C-terminal portions of the Agrobacterium VirB1 protein independently enhance tumorigenesis.

Genetic transformation of plants by Agrobacterium tumefaciens is mediated by a virulence (vir)-specific type IV secretion apparatus assembled from 11 VirB proteins and VirD4. VirB1, targeted to the periplasm by an N-terminal signal peptide, is processed to yield VirB1*, comprising the C-terminal 73 amino acids. The N-terminal segment, which shares homology with chicken egg white lysozyme as well as lytic transglycosylases, may provide local lysis of the peptidoglycan cell wall to create channels for transporter assembly. Synthesis of VirB1* followed by its secretion to the exterior of the cell suggests that VirB1* may also have a role in virulence. In the present study, we provide evidence for the dual roles of VirB1 in tumorigenesis as well as the requirements for processing and secretion of VirB1*. Complementation of a virB1 deletion strain with constructs expressing either the N-terminal lysozyme-homologous region or VirB1* results in tumors intermediate in size between those induced by a wild-type strain and a virB1 deletion strain, suggesting that each domain has a unique role in tumorigenesis. The secretion of VirB1* translationally fused to the signal peptide indicates that processing and secretion are not coupled. When expressed independently of all other vir genes, VirB1 was processed and VirB1* was secreted. When restricted to the cytoplasm by deletion of the signal peptide, VirB1 was neither processed nor secreted and did not restore virulence to the virB1 deletion strain. Thus, factors that mediate processing of VirB1 and secretion of VirB1* are localized in the periplasm or outer membrane and are not subject to vir regulation.

Agrobacterium tumefaciens↗
PubMed1999

New tools for protein linkage mapping and general two-hybrid screening.

The two-hybrid system has proved to be a facile method for detecting and analyzing protein-protein interactions. An expanded application of this system, protein linkage mapping, provides a means of identifying interactions on a global scale and should prove a powerful tool in analyzing whole genomes as their sequences become available. To overcome some of the inherent difficulties in such a large-scale approach, we have constructed a set of new strains and vectors that will allow for more efficient screening. The strains contain a GAL1-URA3 reporter for positive and negative selection, as well as a UAS(G)-lacZ reporter. The strains are of opposite mating types, permitting libraries present in one strain to be easily screened against a second library in the companion strain. We also constructed a family of CEN-based vectors for expression of both Gal4 DNA-binding and activation domain fusions. These plasmids include a hemagglutinin epitope tag and different polylinkers to increase the ease of subcloning. CEN-based vectors are maintained at 1-2 copies per cell, limiting the number of individual cells containing multiple plasmids that can confuse further analyses, and ensuring that fusions are not expressed at toxic levels. Using these vectors, both homo- and heterodimeric interactions resulted in up to 10-fold higher reporter gene transcription than obtained with 2micro;-based plasmids, despite significantly lower protein levels. In addition to protein linkage mapping, these reagents should be generally useful in standard two-hybrid applications.

Base Sequence↗
PubMed1995

Tobacco mosaic virus movement protein associates with the cytoskeleton in tobacco cells.

Tobacco mosaic virus movement protein P30 complexes with genomic viral RNA for transport through plasmodesmata, the plant intercellular connections. Although most research with P30 focuses on its targeting to and gating of plasmodesmata, the mechanisms of P30 intracellular movement to plasmodesmata have not been defined. To examine P30 intracellular localization, we used tobacco protoplasts, which lack plasmodesmata, for transfection with plasmids carrying P30 coding sequences under a constitutive promoter and for infection with tobacco mosaic virus particles. In both systems, P30 appears as filaments that colocalize primarily with microtubules. To a lesser extent, P30 filaments colocalize with actin filaments, and in vitro experiments suggested that P30 can bind directly to actin and tubulin. This association of P30 with cytoskeletal elements may play a critical role in intracellular transport of the P30-viral RNA complex through the cytoplasm to and possibly through plasmodesmata.

Actins↗
PubMed1994

Gestational age and intrauterine growth retardation among white and black very low birthweight infants: a population-based cohort study.

Very low birthweight (VLBW) is a commonly used endpoint in perinatal epidemiology, but the population of VLBW infants comprises a wide range of gestational ages and rates of fetal growth. We used data from a population-based study of all 1072 black and white VLBW liveborn infants born in 29 counties in Georgia between April 1986 and March 1988. Less than 1% of the VLBW infants were > or = 37 weeks gestation; most were 29-32 weeks (26%) or 25 to 28 weeks (40%); 12% were 22 weeks or less. All infants 33 weeks gestation or greater were growth retarded. The population of VLBW infants seems to comprise three groups: approximately 11% very immature infants of 22 weeks or less; the majority of infants, born between 23 and 30 weeks, 90% of which are of normal weight for their gestational age; and a group of less premature, growth-retarded infants from 31 to 36 weeks. We found little or no difference in the distribution of gestational age or the percentage of intrauterine growth rates (IUGR) between black and white infants. In the USA the VLBW rate among black infants is over three times greater than that among white infants and consequently the rates of the three types of VLBW among black infants are likely to be triple those among white infants.

Black People↗
PubMed1993

Patterns of use of obstetrical interventions in 12 countries.

Recent obstetrical practice trends in 12 countries were surveyed. There was a 3-fold difference in caesarean section rates and a 10-fold difference in instrumental vaginal delivery rates among countries. There was a net increase in the caesarean section rate of all countries over the study period and a net decrease in the instrumental vaginal delivery rate of some countries. There was a decrease in the caesarean section rate during the last year of observation in Australia, Denmark and Finland. In general, countries with high caesarean rates also had high instrumental vaginal delivery rates. There was no consistent relationship between use of caesarean section and use of instrumental vaginal delivery, although in several countries increasing use of caesarean section was accompanied by decreasing use of instrumental vaginal delivery. Oxytocin use rates were associated positively with instrumental delivery but not with caesarean section rates. While it was not possible to determine the proportions of women who received appropriate obstetrical care, we can infer that a significant proportion of interventions were unnecessary or only marginally beneficial. Continued increases in rates of obstetrical intervention are unlikely to result in improvements in birth outcome overall and may pose a risk to mothers and their newborns.

Australia↗
PubMed1993

Careprovider and obstetrical interventions--a comparative study of four European countries.

The purpose of this study was to compare the treatment recommendations of obstetricians and midwives in four European countries: the Czech Republic, Finland, Hungary, and Slovenia. Intervention orientation was examined with six hypothetical patient cases. We wanted to learn whether midwives differ from obstetricians in their choices, and whether there is any variation among countries regarding the willingness of staff to intervene. In Finland the two professions were quite similar in their recommendations for interventions, but in Hungary and Slovenia, midwives and obstetricians differed from each other. There were also differences between the countries in the treatment recommendations, and there was disparity between opinions and actual obstetrical practices. Slovenian obstetrical staff were the most interventionistic in many cases, compared with others, although the actual frequency of interventions was no greater than in other countries. In Finland the staff were the most passive in their opinions, yet the actual proportion of interventions was greatest.

Adult↗
PubMed1992

Nuclear localization of Agrobacterium VirE2 protein in plant cells.

The Agrobacterium single-stranded DNA (ssDNA) intermediate T-strand is likely transferred to the plant cell nucleus as a complex with a single VirD2 molecule at its 5' end and multiple VirE2 molecules along its length. VirD2 contains a nuclear localization signal (NLS); however, because the T-strand is principally coated with VirE2 molecules, VirE2 also might assist in nuclear uptake. Indeed, VirE2 fused to a reporter protein localizes to plant cell nuclei, a process mediated by two amino acid sequences with homology to the bipartite NLS of Xenopus nucleoplasmin. Moreover, tumorigenicity of an avirulent virE2 mutant is restored when inoculated on transgenic plants expressing VirE2, supporting in planta function of VirE2.

Amino Acid Sequence↗