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At least 163 records · Page 9Linked to original sources
PubMed2002

Screening for symptoms of eating disorders: reliability of the SCOFF screening tool with written compared to oral delivery.

OBJECTIVE: The validity of the SCOFF delivered orally as a screening tool for eating disorders has previously been established, but clinical screening for eating disorders also occurs via written format, for example, in occupational health settings. The objective was to compare responses to the SCOFF between verbal and written administration. METHOD: In a volunteer group of nursing and midwifery students at a South London University SCOFF was delivered orally at interview and via written questionnaire. Order was allocated randomly with repeat administration interrupted by distraction questions. RESULTS: There were 185 students who participated, providing 178 fully completed responses. Twenty subjects were male. There was overall agreement in the scores of 157 subjects (88.2%), providing a kappa coefficient of 0.811, with agreement in prediction of eating disorder for 167 (93.8%) and a kappa value of 0.824 (both p < 0.001). For 82 subjects administered the SCOFF verbally first followed by the written version, the kappa statistic was 0.752 (p < 0.001). For 96 subjects with SCOFF administered in reverse order (written form first), kappa was 0.862 (p < 0.001). DISCUSSION: Results demonstrated overall good replicability of the SCOFF administered as a written questionnaire compared to oral interview. Two trends were noted. The first was towards higher scores with written versus oral delivery irrespective of order, possibly indicating enhanced disclosure via written format. The second was of less consistency where verbal preceded written responses. Altogether findings support use of the SCOFF where a concise, valid and reliable screening for eating disorders is required in written form.

Anorexia Nervosa↗
PubMedDate not supplied

Generalized Crick equations for modeling noncanonical coiled coils.

Crick envisaged the alpha-helical coiled coil to result from systematic bending of an alpha-helix such that every seventh residue was structurally equivalent, and he derived equations for the coordinates of the backbone atoms. Crick's predictions were vindicated experimentally and coiled-coil sequences were shown to have hydrophobic residues alternately spaced 3 and 4 residues apart. Nonetheless, in some coiled coils such canonical heptad repeats are interrupted by inserts of 3 or 4 residues generating decad and hendecad motifs. The supercoiling of the coiled coils varies with the sequence pattern, being left- or right-handed in purely heptad-based or hendecad-based motifs, respectively. To model coiled coils with a mixture of motifs, we describe how Crick's equations can be modified for cases where the pitch is not constant. Using the analogy of the bending of a beam, we took the tilt angle to change linearly with distance along the major helix and the pitch of a motif to be affected by neighboring motifs depending on the rigidity of the alpha-helical strands. We tested our approach by fitting the two-, three-, and four-stranded noncanonical coiled coils of GrpE, hemagglutinin, and tetrabrachion. The backbone atoms of the model and crystal structures agreed with root mean square deviations of <1.1 A.

Amino Acid Motifs↗
PubMed1983

Evaluation of antiarrhythmic activity of prostaglandin F2 alpha in man.

Since prostaglandin (PG) F2 alpha had been shown to act anti-arrhythmically in various animal models and also in preliminary investigations in man, further evaluation of this effect was made in 30 patients with cardiac extrasystoles and in 2 patients with tachycardias. PGF2 alpha was infused intravenously at individually adapted consecutive rates from 5 to 100 micrograms/min each for at least 5 min. In the incidence of extrasystoles a mean maximum decrease of 41% (P less than 0.001) was obtained. One patient showed repeated short interruptions of a ventricular tachycardia. A dose-dependent significant rise in blood pressure and no significant influences on heart rate, PQ interval and QRS interval of the ECG were found. It is concluded that PGF2 alpha has probably no practical importance for the therapy of cardiac arrhythmias.

Adult↗
PubMed1998

LVAD power delivery: a percutaneous approach to avoid infection.

BACKGROUND: Driveline infection limits the event-free survival of patients with a left ventricular assist device. With the evolving prospect of improved left ventricular assist devices in the bridge-to-transplantation or recovery setting, we sought to reduce the risk of driveline complications. METHODS: As part of the Oxford Jarvik 2000 research program, we developed a carbon and then titanium pedestal to transmit the electric wires through the skin. In a sheep model, the pedestal was brought out through the skin of the shoulder (n = 10) or the scalp (n = 9) with underlying fixation to the skull. Exit wounds were carefully inspected for healing and infection. Power cable durability tests were performed in 6 additional animals without an implanted pump. RESULTS: The cumulative observation period was 1,491 days (mean time, 78 days; range, 14 days to 198 days). There was no difference in observation period between the two groups. Infection (n = 2) and impaired healing (n = 5) occurred in the mobile tissues at the shoulder. Skull-mounted pedestals were free from infection or healing problems. The electric cables were not interrupted by repeated neck flexion (cumulative observation period, 588 days). The carbon pedestal was replaced by a titanium pedestal when the head butting of the sheep fractured the carbon. CONCLUSIONS: The combination of rigid fixation and highly vascular scalp skin reduces the risk of percutaneous driveline infection and may solve an important outstanding problem in use of left ventricular assist devices.

Animals↗
PubMed1989

Sequence analysis of the 5' region of the human DF3 breast carcinoma-associated antigen gene.

DF3 antigen is a high molecular weight glycoprotein detectable in human breast carcinomas. Recent studies have demonstrated that the gene coding for the DF3 core protein consists in part of highly conserved 60 base pair tandem repeats. The present work extends these findings by identifying the region of the DF3 gene 5' to the repeats. The results of primer extension studies demonstrate that the transcription start site of the cDNA is 384 base pairs upstream to the first tandem repeat. Comparison of the cDNA and genomic sequences has demonstrated that the sequences transcribed upstream to the repeats are interrupted by the presence of an intron at 124 bases after the start site. We have also identified the putative promoter region of the DF3 region. This region has several elements, including a TATA sequence and multiple GC boxes, that may be involved in the regulation of DF3 gene transcription.

Amino Acid Sequence↗
PubMed1996

Theoretical analysis of the kinetics of DNA hybridization with gel-immobilized oligonucleotides.

A new method of DNA sequencing by hybridization using a microchip containing a set of immobilized oligonucleotides is being developed. A theoretical analysis is presented of the kinetics of DNA hybridization with deoxynucleotide molecules chemically tethered in a polyacrylamide gel layer. The analysis has shown that long-term evolution of the spatial distribution and of the amount of DNA bound in a hybridization cell is governed by "retarded diffusion," i.e., diffusion of the DNA interrupted by repeated association and dissociation with immobile oligonucleotide molecules. Retarded diffusion determines the characteristic time of establishing a final equilibrium state in a cell, i.e., the state with the maximum quantity and a uniform distribution of bound DNA. In the case of cells with the most stable, perfect duplexes, the characteristic time of retarded diffusion (which is proportional to the equilibrium binding constant and to the concentration of binding sites) can be longer than the duration of the real hybridization procedure. This conclusion is indirectly confirmed by the observation of nonuniform fluorescence of labeled DNA in perfect-match hybridization cells (brighter at the edges). For optimal discrimination of perfect duplexes from duplexes with mismatches the hybridization process should be brought to equilibrium under low-temperature nonsaturation conditions for all cells. The kinetic differences between perfect and nonperfect duplexes in the gel allow further improvement in the discrimination through additional washing at low temperature after hybridization.

DNA↗
PubMed1994

Termination of pregnancy for maternal toxoplasmosis.

Termination of pregnancy is usually recommended to pregnant women who have infection with Toxoplasma gondii before 26 weeks of pregnancy if the fetus is infected. No prospective studies are available on the outcome if such pregnancies are allowed to continue with anti-parasitic treatment. We prospectively studied 163 mothers with acute toxoplasma infection before 28 weeks of amenorrhoea. All received anti-parasitic treatment with 9 million IU spiramycin orally. 23 also received pyrimethamine and sulphadiazine. All had cordocentesis and regular obstetric ultrasound examinations. The 162 liveborn infants were followed up for 15 to 71 months. 3 fetuses died in utero. 27 of 162 liveborn infants had proven congenital toxoplasmosis: 10 had one or more clinical signs of congenital toxoplasmosis; 5 had isolated or multiple intracranial calcifications; 7 had peripheral chorioretinitis; and 2 had moderate ventricular dilations. All 27 are free from symptoms and have normal neurological development at 15 to 71 months of age. We conclude that in first and second trimester pregnancies with acute fetal toxoplasma infection, the pregnancy need not be interrupted if repeated fetal ultrasound is normal, and antiparasitic treatment is given.

Abortion, Eugenic↗
PubMed2004

Microsatellite variation among divergent populations of stalk-eyed flies, genus Cyrtodiopsis.

Microsatellite primers are often developed in one species and used to assess neutral variability in related species. Such analyses may be confounded by ascertainment bias (i.e. a decline in amplification success and allelic variability with increasing genetic distance from the source of the microsatellites). In addition, other factors, such as the size of the microsatellite, whether it consists of perfect or interrupted tandem repeats, and whether it is autosomal or X-linked, can affect variation. To test the relative importance of these factors on microsatellite variation, we examine patterns of amplification and allelic diversity in 52 microsatellite loci amplified from five individuals in each of six populations of Cyrtodiopsis stalk-eyed flies that range from 2.2 % to 11.2% mitochondrial DNA sequence divergence from the population used for microsatellite development. We find that amplification success and most measures of allelic diversity declined with genetic distance from the source population, in some cases an order of magnitude faster than in birds or mammals. The median and range of the repeat array length did not decline with genetic distance. In addition, for loci on the X chromosome, we find evidence of lower observed heterozygosity compared with loci on autosomes. The differences in variability between X-linked and autosomal loci are not adequately explained by differences in effective population sizes of the chromosomes. We suggest, instead, that periodic selection events associated with X-chromosome meiotic drive, which is present in many of these populations, reduces X-linked variation.

Animals↗
PubMedDate not supplied

[epiDRB--a new minimally invasive concept for referencing in the field of computer-assisted orthopaedic surgery].

AIM: Optoelectronic navigation for computer-assisted orthopaedic surgery (CAOS) is based on a firm connection of bone with passive reflectors or active light-emitting diodes in a specific three-dimensional pattern. Even a so-called "minimally-invasive" dynamic reference base (DRB) requires fixation with screws or clamps via incision of the skin. Consequently an originally percutaneous intervention would unnecessarily be extended to an open procedure. Thus, computer-assisted navigation is rarely applied. Due to their tree-like design most DRB's interfere with the surgeon's actions and therefore are at permanent risk to be accidentally dislocated. Accordingly, the optic communication between the camera and the operative site may repeatedly be interrupted. The aim of the research was the development of a less bulky, more comfortable, stable and safely trackable device that can be fixed truly percutaneously. METHOD: With engineering support of the industrial partner the radiolucent epiDRB was developed. It can be fixed with two or more pins and gains additional stability from its epicutaneous position. The intraoperative applicability and reliability was experimentally tested. RESULTS: Its low centre of gravity and its flat design allow the device to be located directly in the area of interest. Thanks to its epicutaneous position and its particular shape the epiDRB may perpetually be tracked by the navigation system without hindering the surgeon's actions. Hence, the risk of being displaced by accident is minimised and the line of sight remains unaffected. CONCLUSION: With the newly developed epiDRB computer-assisted navigation becomes easier and safer to handle even in punctures and other percutaneous procedures at the spine as much as at the extremities without an unproportionate amount of additional trauma. Due to the special design referencing of more than one vertebral body is possible at one time, thus decreasing radiation exposure and increasing efficiency.

Equipment Design↗
PubMed1982

A transposable element from Halobacterium halobium which inactivates the bacteriorhodopsin gene.

We describe the characterization of a transposable element from an archaebacterium. The bacteriorhodopsin genes from the wild-type and two mutant Halobacterium halobium strains have been cloned as BamHI fragments in pBR322. The cloned DNA fragments from the two mutants both contain a 1.1-kilobase-pair insertion sequence (ISH1) near the NH2 terminus of the bacteriorhodopsin coding sequence. ISH1 is present in the two mutants in an identical palindromic site but in opposite orientations. The complete sequence of ISH1 has been determined; it is 1,118 nucleotides long, it has 8-base-pair interrupted inverted repeats at the ends, and it duplicates an 8-base-pair (A-G-T-T-A-T-T-G) target sequence upon insertion. As for most eukaryotic and some prokaryotic transposable elements, the sequence of the ISH1 begins with T-G and ends in C-A. ISH1 contains an open reading frame 810 nucleotides long and codes for an RNA approximately 900 nucleotides long. The copy number of ISH1 ranges from one to five or more in different H. halobium strains. In at least one of the strains, one copy of ISH1 is present also on a plasmid DNA.

Bacteriorhodopsins↗
PubMed1998

The anhidrotic ectodermal dysplasia gene (EDA) undergoes alternative splicing and encodes ectodysplasin-A with deletion mutations in collagenous repeats.

Anhidrotic ectodermal dysplasia (EDA) is an X-linked recessive disorder which affects ectodermal structures. A cDNA encoding a 135 amino acid protein with mutations in 5-10% of EDA patients has been reported. We have built up a complete splicing map of the EDA gene and characterized the longest and what most probably represents the full-length EDA transcript, EDA-A. It encodes a 391 amino acid transmembrane protein with a short collagenous domain, (Gly-X-Y)19, and is highly homologous to the protein mutated in Tabby mice (Ta-A). Four new transcripts that code for truncated proteins lacking the collagenous domain were also detected. The splice variants show different expression patterns in eight tissues analyzed, suggesting a regulatory mechanism for gene expression. The EDA-A form of the protein is transported to the cell membrane and induces rounding of the cells, properties also associated with the 135 amino acid isoform. We have determined the genomic organization and the exon-intron boundaries of the EDA gene. SSCP analysis of the nine exons corresponding to EDA-A allowed the identification of mutations in 12 out of 15 EDA patients. Interestingly, three mutations removed either two or four of the Gly-X-Y repeats without interrupting the reading frame, thus suggesting a functional role for the collagenous domain. Our results will allow mutation diagnostics in the majority of patients.

Alternative Splicing↗
PubMed2006

MBNL1 and CUGBP1 modify expanded CUG-induced toxicity in a Drosophila model of myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder caused by a CTG expansion in the 3' UTR of the dystrophia myotonica protein kinase (DMPK) gene. It has been hypothesized that the pathogenesis in DM1 is triggered by a toxic gain of function of the expanded DMPK RNA. This expanded RNA is retained in nuclear foci where it sequesters and induces alterations in the levels of RNA-binding proteins (RNA-BP). To model DM1 and study the implication of RNA-BP in CUG-induced toxicity, we have generated a Drosophila DM1 model expressing a non-coding mRNA containing 480 interrupted CUG repeats; i.e. [(CUG)20CUCGA]24. This (iCUG)480 transcript accumulates in nuclear foci and its expression leads to muscle wasting and degeneration in Drosophila. We also report that altering the levels of two RNA-BP known to be involved in DM1 pathogenesis, MBNL1 and CUGBP1, modify the (iCUG)480 degenerative phenotypes. Expanded CUG-induced toxicity in Drosophila is suppressed when MBNL1 expression levels are increased, and enhanced when MBNL1 levels are reduced. In addition, (iCUG)480 also causes a decrease in the levels of soluble MBNL1 that is sequestered in the CUG-containing nuclear foci. In contrast, increasing the levels of CUGBP1 worsens (iCUG)480-induced degeneration even though CUGBP1 distribution is not altered by the expression of the expanded triplet repeat. Our data supports a mechanism for DM1 pathogenesis in which decreased levels of MBNL and increased levels of CUGBP mediate the RNA-induced toxicity observed in DM1. Perhaps more importantly, they also provide proof of the principle that CUG-induced muscle toxicity can be suppressed.

Animals↗
PubMed2000

Recurrent use of newer oral contraceptives and the risk of venous thromboembolism.

The epidemiological studies that assessed the risk of venous thromboembolism (VTE) associated with newer oral contraceptives (OC) did not distinguish between patterns of OC use, namely first-time users, repeaters and switchers. Data from a Transnational case-control study were used to assess the risk of VTE for the latter patterns of use, while accounting for duration of use. Over the period 1993-1996, 551 cases of VTE were identified in Germany and the UK along with 2066 controls. Totals of 128 cases and 650 controls were analysed for repeat use and 135 cases and 622 controls for switching patterns. The adjusted rate ratio of VTE for repeat users of third generation OC was 0.6 (95% CI:0.3-1.2) relative to repeat users of second generation pills, whereas it was 1.3 (95% CI:0.7-2.4) for switchers from second to third generation pills relative to switchers from third to second generation pills. We conclude that second and third generation agents are associated with equivalent risks of VTE when the same agent is used repeatedly after interruption periods or when users are switched between the two generations of pills. These analyses suggest that the higher risk observed for the newer OC in other studies may be the result of inadequate comparisons of pill users with different patterns of pill use.

Adult↗
PubMed1991

Constitutive expression of the urokinase plasminogen activator gene in murine RAW264 macrophages involves distal and 5' non-coding sequences that are conserved between mouse and pig.

The 5' flanking regions of the mouse and pig urokinase plasminogen activator (uPA) genes were sequenced and sequence homology interrupted by repeat elements was found to extend to -4.6kb in pig and -6.6kb in mouse. A transient transfection procedure was devised for the murine macrophage cell line RAW264. Pig uPA promoter-CAT constructs were more active than mouse constructs in this assay. This contrast may involve sequence differences within 100 bp of the transcription start site. The selective deletion of distal regions of the promoter (greater than 2.6 kb upstream), and of a conserved element, 5'-AGGAGGAAATGAGG-TCA-3' around -2 kb greatly reduced the activity of reporter constructs in RAW264 cells. Electrophoretic mobility shift assays using the latter sequence identified a single nuclear protein complex. This element has been referred to as PEA3/AP1-like, but the complex did not comigrate with either AP1 or known proteins that bind polypurines (including the macrophage-specific factor PU-1) and was not competed by AP1 or polypurine oligonucleotides. uPA promoters contain multiple AP1 and AP2-like DNA sequences, which were recognised by nuclear proteins expressed constitutively in RAW264 cells. They also contain multiple binding sites for NF kappa B but activated NF kappa B was not expressed in RAW264 cells. The conserved, transcribed 5' non-coding sequences were also required for maximal gene expression. Hence, the uPA promoter contains multiple weak cis-acting elements distributed over 7.0 kb 5' to the translation start site.

Animals↗
PubMed2000

Critical nucleotides in the interaction of CatR with the pheBA promoter: conservation of the CatR-mediated regulation mechanisms between the pheBA and catBCA operons.

The promoter of the plasmid-borne pheBA genes encoding enzymes for phenol degradation resembles the catBCA promoter and is activated by CatR, the regulator of the chromosomally encoded catechol-degradative catBCA genes in Pseudomonas putida. In this study, site-directed mutagenesis of the pheBA promoter region was performed. The interrupted inverted repeat sequence of the CatR recognition binding site (RBS) of the pheBA promoter is highly homologous to that of the catBCA promoter. However, the RBS was shown not to be the sole important feature for high-affinity binding of CatR to this site. Mutagenesis of the activation binding site (ABS) of CatR, which overlaps the -35 hexamer sequence TTGGAT of the promoter, revealed that the two G nucleotides in this sequence are important for promoter activity but not for CatR binding. All other substitutions made in the ABS negatively affected both the promoter activity and CatR binding. The spacer sequence of the pheBA and catBCA promoters between the -10 and -35 hexamers is 19 bp, which is longer than optimal. However, reducing the spacer region of the pheBA promoter was not sufficient for CatR-independent promoter activation. An internal binding site (IBS) for CatR is located downstream of the transcriptional start site of the catBCA genes and it negatively regulates the operon. A similar IBS was identified in the case of the pheBA operon and tested for its functionality. The results indicate a conservation of CatR-mediated regulation mechanisms between the pheBA promoter and the catBCA promoter. This universal mechanism of CatR-mediated transcriptional activation could be of great importance in enabling catechol-degrading bacteria to expand their substrate range via horizontal transfer of the phenol degradative genes.

Bacterial Proteins↗
PubMed1983

Self-conversion of drug resistant ventricular tachycardia by rapid atrial pacing.

A 523-year-old man with recurrent ventricular tachycardia two months post myocardial infarction is described. The tachycardia resulted in low output and heart failure at the time of presentation. Following electrocardioversion of ventricular tachycardia, sinus rhythm would last for only a few seconds, and ventricular tachycardia could not be terminated or prevented by drugs, nor by overdrive pacing. Over a 20-hour period, asynchronous right ventricular pacing at 30/min resulted in repeated random interruption of successive paroxysms of ventricular tachycardia, resulting in maintenance of sinus rhythm about 60 to 70% of the time. This produced marked hemodynamic improvement and a decrease in the frequency of paroxysms of tachycardia which, however, continued to recur once every few days. Despite their reduced frequency, these paroxysms continued to be resistant to drugs and had to be terminated by cardioversion. At this point it was discovered that rapid atrial pacing was able to terminate the patient's tachycardia reliably and reproducibly. A permanent right atrial externally activated radio frequency pacemaker device was inserted and over the ensuing eighteen-month period the patient self-terminated over fifty discrete episodes of ventricular tachycardia.

Anti-Arrhythmia Agents↗
PubMed1986

Differential elimination of rDNA genes in bobbed mutants of Drosophila melanogaster.

In Drosophila melanogaster, the multiply repeated genes encoding 18S and 28S rRNA are located on the X and Y chromosomes. A large percentage of these repeats are interrupted in the 28S region by insertions of two types. We compared the restriction patterns from a subcloned wild-type Oregon R strain to those of spontaneous and ethyl methanesulfonate-induced bobbed mutants. Bobbed mutations were found to be deficiencies that modified the organization of the rDNA locus. Genes without insertions were deleted about twice as often as genes with type I insertions. Type II insertion genes were not decreased in number, except in the mutant having the most bobbed phenotype. Reversion to wild type was associated with an increase in gene copy number, affecting exclusively genes without insertions. One hypothesis which explains these results is the partial clustering of genes by type. The initial deletion could then be due either to an unequal crossover or to loss of material without exchange. Some of our findings indicated that deletion may be associated with an amplification phenomenon, the magnitude of which would be dependent on the amount of clustering of specific gene types at the locus.

Animals↗
PubMed1982

Evaluation of blood gas quality control and proficiency testing materials by tonometry.

Because of consistent differences found by other investigators and by us, we systematically tonometered, sampled, and measured PO2 and PCO2 concentrations of fresh blood, plasma, and several commercial quality control materials in three models of semiautomated blood gas machines. We found no significant differences between materials or machines for PCO2 between 25 to 72 mm Hg. For tonometered PO2 of approximately 25 to 100 mm Hg, the measured PO2 concentrations were accurate for blood, high for materials with hemoglobin or fluorocarbon (high O2 capacity), and very high for other materials (low O2 capacity). A low O2 capacity material tonometered to a PO2 of 0 mm Hg gave very high values in semiautomated machines and gave correct values only when injected repeatedly without interrupting rinse cycles into a manual machine. These findings indicate significant contamination of blood gas machines with fluids other than the sample so that low O2 capacity quality control materials are inadequate for proficiency testing at degrees of PO2 below 100 mm Hg.

Blood Gas Analysis↗