Plasma oxidized polyhydroxymethylsiloxane--a new smooth surface for supported lipid bilayer formation.

A novel substrate for preparation of supported lipid bilayers (SLBs), smooth at the subnanometer scale and of variable thickness from ten to several hundred nanometers, was developed by surface oxidation of spin-coated poly(hydroxymethylsiloxane) (PHMS) films. The deposited polymeric thin films were modified by a combination of oxygen plasma and thermal treatment (PHMS(ox)), in order to convert the outermost surface layer of the polymer film to a stable SiO(2) film, suitable for SLB formation. The hydrophilic, SiO(2)-like surfaces were characterized by XPS, wetting angle, ellipsometry, and AFM. Lipid bilayers were formed on this surface using the well-known vesicle adsorption-rupture-fusion process, usually performed on glass or vapor-deposited SiO(2). Reproducible formation of homogeneous SLBs of different compositions (POPC, DOEPC, and POPC/DOPS) was demonstrated on the new SiO(2) surface by quartz crystal microbalance with dissipation (QCM-D), surface plasmon resonance (SPR), and optical reflectometry measurements. The SLB formation kinetics on the PHMS(ox)-coated sensors showed very similar characteristics, for all investigated PHMS thicknesses, as on reference sensors coated with vapor-deposited SiO(2). The good adhesive properties of the PHMS to gold allows for the preparation of thin PHMS(ox) layers compatible with SPR. The much smaller roughness at the nanometer scale of the PHMS(ox) surfaces, compared to standard vapor-deposited SiO(2)-coated sensors, makes them advantageous for AFM and optical experiments and promising for patterning. To benefit optical experiments with the PHMS(ox) surfaces, it was also investigated how the PHMS film thickness influences the SPR and reflectometry responses upon SLB formation.

[Adrenogenital syndrome--molecular biology and prenatal diagnosis]. / Adrenogenitalt syndrom--molekyloerbiologi og proenatal diagnostik.

Congenital adrenal hyperplasia (CAH) comprises a group of autosomal recessive disorders affecting the synthesis of adrenal corticosteroids. CAH is caused by a functional defect in any one of five enzymatic steps required for the biosynthesis of cortisol. Deficiency of 21-hydroxylase is the most frequent of these disorders, accounting for approximately 95% of all CAH cases. 21-hydroxylase deficiency is due to mutations in the gene CYP21 encoding the enzyme. Using molecular biology techniques mutations in the involved families can be characterized, thereby allowing prenatal diagnosis in following pregnancies. Likewise fast and reliable carrier diagnosis can be offered to relatives of the patient.

False-positive results in mammographic screening for breast cancer in Europe: a literature review and survey of service screening programmes.

OBJECTIVE: To estimate the cumulative risk of a false-positive screening result in European mammographic screening programmes, and examine the rates and procedures of further assessment. METHODS: A literature review was conducted to identify studies of the cumulative risk of a false-positive result in European screening programmes (390,000 women). We then examined aggregate data, cross-sectional information about further assessment procedures among women with positive results in 20 mammographic screening programmes from 17 countries (1.7 million initial screens, 5.9 million subsequent screens), collected by the European Network for Information on Cancer project (EUNICE). RESULTS: The estimated cumulative risk of a false-positive screening result in women aged 50-69 undergoing 10 biennial screening tests varied from 8% to 21% in the three studies examined (pooled estimate 19.7%). The cumulative risk of an invasive procedure with benign outcome ranged from 1.8% to 6.3% (pooled estimate 2.9%). The risk of undergoing surgical intervention with benign outcome was 0.9% (one study only). From the EUNICE project, the proportions of all screening examinations in the programmes resulting in needle biopsy were 2.2% and 1.1% for initial and subsequent screens, respectively, though the rates differed between countries; the corresponding rates of surgical interventions among women without breast cancer were 0.19% and 0.07%. CONCLUSION: The specific investigative procedures following a recall should be considered when examining the cumulative risk of a false-positive screening result. Most women with a positive screening test undergo a non-invasive assessment procedure. Only a small proportion of recalled women undergo needle biopsy, and even fewer undergo surgical intervention.

Mammographic screening programmes in Europe: organization, coverage and participation.

OBJECTIVES: To summarize participation and coverage rates in population mammographic screening programmes for breast cancer in Europe. METHODS: We used the European Network for Information on Cancer (EUNICE), a web-based data warehouse (EUNICE Breast Cancer Screening Monitoring, EBCSM) for breast cancer screening, to obtain information on programme characteristics, coverage and participation from its initial application in 10 national and 16 regional programmes in 18 European countries. RESULTS: The total population targeted by the screening programme services covered in the report comprised 26.9 million women predominantly aged 50-69. Most of the collected data relates to 2005, 2006 and/or 2007. The average participation rate across all programmes was 53.4% (range 19.4-88.9% of personally invited); or 66.4% excluding Poland, a large programme that initiated personal invitations in 2007. Thirteen of the 26 programmes achieved the European Union benchmark of acceptable participation (>70%), nine achieved the desirable level (>75%). Despite considerable invitation coverage across all programmes (79.3%, range 50.9-115.2%) only 48.2% (range 28.4-92.1%) of the target population were actually screened. The overall invitation and examination coverage excluding Poland was 70.9% and 50.3%, respectively. CONCLUSIONS: The results demonstrate the feasibility of European-wide screening monitoring using the EBCSM data warehouse, although further efforts to refine the system and to harmonize standards and data collection practices will be required, to fully integrate all European countries. The more than three-fold difference in the examination coverage should be taken into account in the evaluation of service screening programmes.

Mutations in the gene encoding 21-hydroxylase detected by solid-phase minisequencing.

We have developed an assay based on solid-phase minisequencing to screen for the following seven point mutations in the gene CYP21 encoding 21-hydroxylase: Pro30Leu, I2-splice, Ile172Asn, Cluster-E6, Val281Leu, Gln318Stop, and Arg356Trp. 5'-Biotinylated PCR products of CYP21 are bound to streptavidin-coated microtiter wells, where the minisequencing reaction takes place after denaturation of DNA. Depending on the sequence investigated, one specific 3H-labelled deoxyribonucleotide is incorporated to extend a detection primer. By using an appropriate set of detection primers, it is possible to screen the gene for several mutations within the same PCR amplificate. This fast and reliable method very clearly distinguishes between DNA from homozygous mutant, heterozygous, and normal individuals and is well suited for routine diagnosis of patients with 21-hydroxylase deficiency and for carrier detection.

Genetic diagnosis of 21-hydroxylase deficiency: DGGE-based mutation scanning of CYP21.

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is caused by mutations in the gene CYP21 encoding the enzyme steroid 21-hydroxylase. In addition to deletions, approximately 20 different point mutations have been reported, and still novel mutations are detected. This makes genetic diagnosis as well as carrier detection of 21-hydroxylase deficiency a complicated matter. We developed a simple nonradioactive assay based on the polymerase chain reaction (PCR) in combination with denaturing gradient gel electrophoresis (DGGE) to screen for mutations in the CYP21 gene. DGGE allows a fast scanning of PCR-amplified segments of genes for the presence or absence of any single base pair alterations. We have performed this technique on the coding sequence and intron-exon junctions of CYP21. Our results emphasize that this procedure constitutes a fast and reliable approach when performing diagnosis of 21-hydroxylase deficiency.

Steroid 21-hydroxylase deficiency: mutational spectrum in Denmark, three novel mutations, and in vitro expression analysis.

We have investigated 68 unrelated 21-hydroxylase deficient Danish patients, representing 136 alleles, and determined the mutational spectrum of the CYP21 gene. The most frequent mutations detected were deletion of CYP21 and the splice mutation in intron 2 (I2-splice). Segregation analysis showed evidence of a de novo mutation in each of two patients. Three novel mutations were detected: G64E in exon 1, Q262X in exon 7, and A362V in exon 8. G64E and A362V were introduced in the CYP21 cDNA by in vitro site-directed mutagenesis, and the two corresponding proteins were transiently expressed in COS-7 cells. The activity of 21-hydroxylase was determined using the two hormone substrates 17-hydroxyprogesterone and progesterone. The analysis showed no enzyme activity for any of the substrates, a result that correlates well with the severity of the patients' disease.

Warm tub bathing during labor: maternal and neonatal effects.

AIM: To study possible detrimental maternal and neonatal effects of immersion in warm water during labor. DESIGN: Prospective randomized controlled bathing during first stage of labor vs no bathing. SETTING: Obstetrical departments at a university hospital and two central hospitals. PRIMARY END-POINT: Referral of newborns to NICU. MATERIAL AND METHODS: Randomization took place by means of sealed opaque envelopes at each delivery unit. Preconditions for participation in the study were: singleton parturient wishing to bathe, a gestational duration of at least 35 weeks+0 days, a planned vaginal delivery, normal admission test, regular contractions and cervix dilated to at least 3-4 cm. Parturients randomized to the 'no bath' control group were allowed to use a shower. Rupture of the membranes was not a contra-indication to participation. Those excluded from randomization were women with intra-uterine growth retardation, meconium-stained amniotic fluid, or in the event that the tub was occupied by another randomized parturient. MAIN RESULTS: On average, parturients stayed in the tub for 50-60 min. No significant difference was seen regarding the referral rate to NICU among 612 cases vs 625 controls, OR 0.8; 95% CL 0.2, 3.1. The OR for epidural analgesia was 1.0; 95% CL 0.8, 1.3. Nor was any significant difference seen in the rate of perineal tear grade III-IV (OR 1.3), instrumental delivery (OR 1.1), cesarean section (OR 1.8), or maternal post partum stay on the ward. During the neonatal period, no significant difference was seen in the number of newborns with Apgar <7 at 5 min (4 vs 5), neonatal distress (OR 2.2) or tachypnéa (OR 1.0). CONCLUSION: In the present study no negative effects of bathing during labor could be discerned. The results indicate that expectant mothers wishing to bathe during labor may do so without jeopardizing their own, or their newborns' wellbeing after birth.