Evidence suggesting interactions between immunodominant membrane protein Imp of Flavescence dorée phytoplasma and protein extracts from distantly related insect species.

AIMS: In this study, binding between the immunodominant membrane protein Imp of the 16SrV-D phytoplasma associated with Flavescence dorée disease (FD-Dp) and insect proteins of vectors and non-vectors of FD-Dp was tested. METHODS AND RESULTS: Six Auchenorrhyncha species, from distantly related groups were selected: Scaphoideus titanus, Euscelidius variegatus, Macrosteles quadripunctulatus, Zyginidia pullula (Cicadomorpha), Ricania speculum and Metcalfa pruinosa (Fulgoromorpha). The vector status of each species was retrieved from the literature or determined by transmission trials in this study. A His-tagged partial Imp protein and a rabbit polyclonal antibody were synthesized and used for Western and Far-Western dot Blot (FWdB) experiments. Total native and membrane proteins (MP) were extracted from entire bodies and organs (gut and salivary glands) of each insect species. FWdB showed decreasing interaction intensities of Imp fusion protein with total proteins from entire bodies of S. titanus, E. variegatus (competent vectors) and M. quadripunctulatus (non-vector), while no interaction signal was detected with the other three species (non-vectors). A strong signal detected upon interaction of FD-D Imp and MP from guts of closely related insects supports the role of this organ as the first barrier to ensure successful transmission. CONCLUSIONS: Our results showed that specific Imp binding, correlated with vector status, is involved in interactions between FD-Dp and insect proteins. SIGNIFICANCE AND IMPACT OF THE STUDY: Integrating knowledge on host-pathogen protein-protein interactions and on insect phylogeny would help to identify the actual range of vectors of phytoplasma strains of economic importance.

Estimating the value of surgical clips for target volume delineation in external beam partial breast radiotherapy.

AIMS: To investigate the role of surgical clips in defining the clinical target volume (CTV) for three-dimensional conformal external beam radiotherapy-partial breast irradiation (3D-CRT-PBI) using preoperative computed tomography scans. MATERIALS AND METHODS: A group of patients with early breast cancer underwent conservative surgery with placement of surgical titanium clips (at least three clips required). All patients had a treatment planning computed tomography simulation before (CT1) and after surgery (CT2). The two sets of images were co-registered with a match point registration. The relationship between the clips-based CTV for PBI delineated on CT2 and the initial tumour location on CT1 was studied, evaluating the percentage of intersection volume. RESULTS: Twenty-eight patients participated in this study. In total, 13 patients (46.4%) had an intersection volume ≥ 50% and 10 patients (35.7%) had complete intersection (intersection volume = 100%). An increased median intersection volume was observed in patients with more than six clips (P = 0.007) and in patients with a larger portion of breast volume covered by the PBI-CTV (CTV/BV; P = 0.010). Intersection volume increased with the number of clips, after adjustment for CTV/BV (linear coefficient = 5.1693; P = 0.043). Also, a maximum distance from the chest wall ≤0.7 cm and CTV/BV > 9.5% were found to be predictors of an intersection volume ≥50% (area under the curve 0.841; confidence interval 0.649-0.952; P < 0.0001; area under the curve 0.800; confidence interval 0.607-0.926; P = 0.0004) and of an intersection volume of 100% (area under the curve 0.776, confidence interval 0.573-0.916, P = 0.046; area under the curve 0.752, confidence interval 0.536-0.935; P = 0.032). CONCLUSIONS: Titanium clips are essential and six or more increase the accuracy of tumour bed delineation for PBI; also the primary tumour location as well as the percentage of volume of breast covered by PBI-CTV may influence the correct delineation of PBI-CTV.

A comprehensive tool for image-based generation of fetus and pregnant women mesh models for numerical dosimetry studies.

Fetal dosimetry studies require the development of accurate numerical 3D models of the pregnant woman and the fetus. This paper proposes a 3D articulated fetal growth model covering the main phases of pregnancy and a pregnant woman model combining the utero-fetal structures and a deformable non-pregnant woman body envelope. The structures of interest were automatically or semi-automatically (depending on the stage of pregnancy) segmented from a database of images and surface meshes were generated. By interpolating linearly between fetal structures, each one can be generated at any age and in any position. A method is also described to insert the utero-fetal structures in the maternal body. A validation of the fetal models is proposed, comparing a set of biometric measurements to medical reference charts. The usability of the pregnant woman model in dosimetry studies is also investigated, with respect to the influence of the abdominal fat layer.

Influence of pregnancy stage and fetus position on the whole-body and local exposure of the fetus to RF-EMF.

This paper analyzes the influence of pregnancy stage and fetus position on the whole-body and brain exposure of the fetus to radiofrequency electromagnetic fields. Our analysis is performed using semi-homogeneous pregnant woman models between 8 and 32 weeks of amenorrhea. By analyzing the influence of the pregnancy stage on the environmental whole-body and local exposure of a fetus in vertical position, head down or head up, in the 2100 MHz frequency band, we concluded that both whole-body and average brain exposures of the fetus decrease during the first pregnancy trimester, while they advance during the pregnancy due to the rapid weight gain of the fetus in these first stages. From the beginning of the second trimester, the whole-body and the average brain exposures are quite stable because the weight gains are quasi proportional to the absorbed power increases. The behavior of the fetus whole-body and local exposures during pregnancy for a fetus in the vertical position with the head up were found to be of a similar level, when compared to the position with the head down they were slightly higher, especially in the brain.

Imaging and 3D morphological analysis of collagen fibrils.

The recent booming of multiphoton imaging of collagen fibrils by means of second harmonic generation microscopy generates the need for the development and automation of quantitative methods for image analysis. Standard approaches sequentially analyse two-dimensional (2D) slices to gain knowledge on the spatial arrangement and dimension of the fibrils, whereas the reconstructed three-dimensional (3D) image yields better information about these characteristics. In this work, a 3D analysis method is proposed for second harmonic generation images of collagen fibrils, based on a recently developed 3D fibre quantification method. This analysis uses operators from mathematical morphology. The fibril structure is scanned with a directional distance transform. Inertia moments of the directional distances yield the main fibre orientation, corresponding to the main inertia axis. The collaboration of directional distances and fibre orientation delivers a geometrical estimate of the fibre radius. The results include local maps as well as global distribution of orientation and radius of the fibrils over the 3D image. They also bring a segmentation of the image into foreground and background, as well as a classification of the foreground pixels into the preferred orientations. This accurate determination of the spatial arrangement of the fibrils within a 3D data set will be most relevant in biomedical applications. It brings the possibility to monitor remodelling of collagen tissues upon a variety of injuries and to guide tissues engineering because biomimetic 3D organizations and density are requested for better integration of implants.

Bio-corrosion characterization of Mg-Zn-X (X = Ca, Mn, Si) alloys for biomedical applications.

The successful applications of magnesium-based alloys as biodegradable orthopedic implants are mainly inhibited due to their high degradation rates in physiological environment. This study examines the bio-corrosion behaviour of Mg-2Zn-0.2X (X = Ca, Mn, Si) alloys in Ringer's physiological solution that simulates bodily fluids, and compares it with that of AZ91 magnesium alloy. Potentiodynamic polarization and electrochemical impedance spectroscopy results showed a better corrosion behaviour of AZ91 alloy with respect to Mg-2Zn-0.2Ca and Mg-2Zn-0.2Si alloys. On the contrary, enhanced corrosion resistance was observed for Mg-2Zn-0.2Mn alloy compared to the AZ91 one: Mg-2Zn-0.2Mn alloy exhibited a four-fold increase in the polarization resistance than AZ91 alloy after 168 h exposure to the Ringer's physiological solution. The improved corrosion behaviour of the Mg-2Zn-0.2Mn alloy with respect to the AZ91 one can be ascribed to enhanced protective properties of the Mg(OH)(2) surface layer. The present study suggests the Mg-2Zn-0.2Mn alloy as a promising candidate for its applications in degradable orthopedic implants, and is worthwhile to further investigate the in vivo corrosion behaviour as well as assessed the mechanical properties of this alloy.

Ochratoxin a: comparison of extraction methods from grapes and quantitative determination by different competitive enzyme-linked immunosorbent assay kits.

The European Community has recently established a maximum limit for ochratoxin A (OTA) concentration in grapevine products, but many practical difficulties remain concerning the establishment of optimum cost-effective methods of quantification. The performance of four extraction procedures and three commercial competitive enzyme-linked immunosorbent assays (cELISAs) for grapes were compared. Results differed for the extractions and the cELISA kits. The advantage of using immunoaffinity columns (IACs) in the extraction was the excellent detection limit, which was between 0.06 and 0.0075 ng ml(-1) depending on the cELISA kit used. Despite lower sensitivity (between 1.2 and 0.15 ng ml(-1) depending on the cELISA kit), an extraction method in liquid phase, which was simple and inexpensive, was confirmed as suitable for quantifying OTA at levels estimated to be dangerous for human health. Two of the three cELISA kits produced satisfactory results. When these two cELISAs were coupled with IAC extraction, the lower quantification limits were 0.010 and 0.0075 ng ml(-1), respectively, and the dynamic ranges were 50 and 27, respectively. The most reliable procedures were then compared with the reference method, high-performance liquid chromatography plus fluorescent detection coupled with an IAC. The results were very similar, although the cELISAs generally provided slightly higher values than did the chromatography method. The IAC method coupled with the cELISA was four times more sensitive than was the IAC method coupled with the chromatography method. The cELISA detection techniques were excellent alternatives to the already established chromatographic protocols, especially for mass screening and for determining concentrations of OTA as low as 0.010 ng ml(-1).

An automated myocardial segmentation in cardiac MRI.

In this paper we present an automatic approach to segment Cardiac Magnetic Resonance (CMR) images. A preprocessing step that consists in filtering the image using connected operators (area opening and closing filters) is applied in order to homogenize the cavity and solve the problems due to the papillary muscles. Thereby the GVF snake algorithm is applied with one point clicked in the cavity as initialization and an optimized tuning of parameters for the endocardial contour extraction. The epicardial border is then obtained using the endocardium as initialization. The performance of the proposed method was assessed by experimentation on thirty-nine CMR images. A high agreement between manual and automatic contours was obtained with correlation scores of 0.96 for the endocardium and 0.90 for the epicardium. Overlapping percentage, mean and maximum distances between the two contours show a good performance of the method.

Interest of the steady state free precession (SSFP) sequence for 3D modeling of the whole fetus.

Fetal magnetic resonance imaging (MRI) has been gaining interest over the last two decades. Current fast MRI sequences provide imaging data of the whole uterus in less than 20 seconds, avoiding fetal motion related artifacts without any maternal or fetal sedation. MRI has proved to be a useful adjunct to echographic screening for prenatal diagnosis. However, MRI volumetric data is still mainly interpreted on 2D slices and 3D applications remain limited. In this paper, we discuss the qualities of the SSFP MRI sequences to provide adequate data for 3D segmentation and modeling of the fetus. Potential exploitations of 3D segmentation and derived anatomical models cover several domains: biometric and morphologic clinical studies, quantitative longitudinal studies of normal and abnormal fetus developments, direct visualization of the overall fetus body and simulations in different fields (surgery, radiation dosimetry,...).

Influence of sodium hypochlorite on fracture properties and corrosion of ProTaper Rotary instruments.

AIM: To evaluate the influence of immersion in NaOCl on resistance to cyclic fatigue fracture and corrosion of ProTaper NiTi Rotary instruments. METHODOLOGY: A total of 120 new ProTaper NiTi Rotary files (F2) were randomized and assigned to three different groups of 40 each. Group 1 was the control group; 20 mm (excluding the shaft) of group 2 instruments were immersed in 5% NaOCl at 50 degrees C for 5 min; instruments in group 3 were completely immersed in 5% NaOCl at 50 degrees C for 5 min. All instruments were then tested for cyclic fatigue, recording the time in seconds to fracture. Data were analysed by the Kruskall-Wallis test and post-hoc multiple comparisons (P < 0.05). Micromorphological and microchemical analyses were also completed by means of a field emission scanning electron microscopy (SEM) on those instruments in group 3 that had undergone early fracture. RESULTS: Instruments in group 3 had a significantly lower resistance to fracture because of cyclic fatigue than those in groups 1 and 2 (P < 0.001). In some instruments in group 3, early fracture occurred after only a few seconds of fatigue testing. SEM observations revealed evident signs of corrosion of the fractured instruments. CONCLUSION: Group 3 had significantly reduced resistance to cyclic fatigue compared with instruments in groups 1 and 2. The phenomenon of early fracture may be attributed to galvanic corrosion induced by the presence of dissimilar metals, where one acts as the cathode of a galvanic couple, established when the instrument is immersed in NaOCl solution. The NiTi alloy may acts as the anode and thus undergoes corrosion.

Effect of micrometer-scale metallic fillers on the mechanical and corrosion resistance properties of alternative materials for conservative dentistry.

In conservative dentistry, glass-ionomer cements (GICs) have been proposed as substitutes for composite resins. This is because the latter, although widely used over the last 10 yrs, exhibit inadequate physico-chemical properties. Although the performance of a typical commercial GIC is not yet optimal for restorative dentistry, the addition of metallic filler could improve this. In this study, a series of commercially available GICs were incorporated in trial dental amalgams, whose mechanical and calorimetric properties and morphologies, were examined. The metallic component of these amalgams comprised one of three metallic fillers, each including micrometer-scale metal particles of a different shape. The corrosion resistance of the amalgams, in fluids simulating the oral cavity environment, was also studied. The addition of metallic filler to GIC produced a general improvement in mechanical properties. Of particular note were increases in the elastic modulus, up to around sixfold, with the addition of Valiant metallic filler to the GIC Fuji II, and of the stress at break, up to around fourfold, for the New Gen metallic filler/GIC Fuji II amalgam. In these cases, the mechanical properties of dentine were studied. Micrographic observations showed a highly compact structure of the added GICs, thus reflecting a reduction in shrinkage. Calorimetric and dilatometric analyses further confirmed the suitability for applications in preservative dentistry. Finally, with respect to corrosion resistance, the effect of the introduction of the metallic filler was beneficial in samples with low porosity.

Abnormal cardiac function in fetuses with increased nuchal translucency.

OBJECTIVE: To evaluate cardiac function in structurally and chromosomally normal fetuses with increased nuchal translucency (NT). METHODS: Forty-two structurally and chromosomally normal fetuses with increased NT at 11-14 weeks of gestation underwent fetal echocardiographic examination at 20-23 weeks. Fifty fetuses with normal NT values were considered as controls. Pulmonary and aortic peak velocity and time to peak velocities were measured as indices of ventricular systolic function. The ratios between the E-wave and A-wave (E/A) and the ratios between the E-wave and time velocity integral (E/TVI) at the level of both atrioventricular valves were evaluated as indices of ventricular diastolic function. RESULTS: In fetuses with increased NT the E/A ratios were significantly decreased when compared to control fetuses at the level of both the mitral (0.52 +/- 0.09 vs. 0.60 +/- 0.10, P = 0.0002) and tricuspid (0.51 +/- 0.09 vs. 0.61 +/- 0.09, P < 0.0001) valves. Similar results were found for the E/TVI ratios (mitral valve 4.79 +/- 1.03 vs. 5.63 +/- 1.23, P = 0.0007 and tricuspid valve 4.40 +/- 0.88 vs. 5.19 +/- 0.82, P < 0.0001). No significant relationship was found between the degree of NT and the abnormalities in Doppler indices. There were no significant differences in Doppler systolic indices. CONCLUSION: Structurally and chromosomally normal fetuses with increased NT have low E/A and E/TVI ratios at 20-23 weeks of gestation. These findings might indicate cardiac diastolic dysfunction.

Comparison of genotypic and phenotypic resistance patterns of human immunodeficiency virus type 1 isolates from patients treated with stavudine and didanosine or zidovudine and lamivudine.

Sequencing of reverse-transcriptase genes and recombinant virus assays were performed on paired isolates from antiretroviral drug-naive patients randomized to stavudine and didanosine (group 1; n = 21) or zidovudine and lamivudine (group 2; n = 21) at baseline and after > or = 12 months of follow-up. The T215Y mutation emerged in 13 (61.9%) and 2 (9.5%) isolates in groups 1 and 2, respectively (P < .0001). Furthermore, in group 1, mutations associated with multidideoxynucleoside resistance were selected in 3 isolates. In group 2, all isolates carried the M184V mutation. The median fold changes in susceptibilities to zidovudine, stavudine, and lamivudine were 16.4 and 1, 2.2 and 0.6, and 4.5 and > 38 in groups 1 and 2, respectively (P < .0001, all comparisons). These results suggest that the combination of stavudine and didanosine is associated more frequently with the emergence of zidovudine resistance and a decrease in susceptibility to stavudine than the combination of zidovudine and lamivudine.

LV volume quantification via spatiotemporal analysis of real-time 3-D echocardiography.

This paper presents a method of four-dimensional (4-D) (3-D + Time) space-frequency analysis for directional denoising and enhancement of real-time three-dimensional (RT3D) ultrasound and quantitative measures in diagnostic cardiac ultrasound. Expansion of echocardiographic volumes is performed with complex exponential wavelet-like basis functions called brushlets. These functions offer good localization in time and frequency and decompose a signal into distinct patterns of oriented harmonics, which are invariant to intensity and contrast range. Deformable-model segmentation is carried out on denoised data after thresholding of transform coefficients. This process attenuates speckle noise while preserving cardiac structure location. The superiority of 4-D over 3-D analysis for decorrelating additive white noise and multiplicative speckle noise on a 4-D phantom volume expanding in time is demonstrated. Quantitative validation, computed for contours and volumes, is performed on in vitro balloon phantoms. Clinical applications of this spaciotemporal analysis tool are reported for six patient cases providing measures of left ventricular volumes and ejection fraction.

La prevención del parto prematuro. Nuevas perspectivas / Prediction of preterm delivery: new approaches

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Ni-Zr alloys: relationship between surface characteristics and electrocatalytic behavior

A relationship between electrocatalytic activity for the hydrogen evolution reaction and the surface composition of the electrode was established for Ni-Zr crystalline and amorphous alloys by means of secondary ion mass spectrometry (SIMS). Electrocatalytic activity was tested by means of cathodic polarization in 1 M KOH at 25 degrees C and the resulting exchange current density has been taken as a measure of catalytic efficiency. Surface activation treatment involved chemical etching in HF solutions; the consequent morphological and compositional surface changes were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical behavior of the pure elements (Ni and Zr) was also considered for comparison. All samples submitted to chemical etching in HF solutions showed an increase in electrocatalytic activity, particularly the alloy with the highest Ni content. The beneficial effect of chemical etching is due to dissolution of the zirconium oxide layer and to the formation of nanocrystalline Ni on the surfaces.

Blood flow velocity waveforms from fetal peripheral pulmonary arteries in pregnancies with preterm premature rupture of the membranes: relationship with pulmonary hypoplasia.

OBJECTIVES: To measure fetal peripheral pulmonary artery velocity waveforms by Doppler ultrasonography in pregnancies complicated by premature rupture of membranes under 24 weeks' gestation and to relate the Doppler indices to the development of fetal pulmonary hypoplasia. DESIGN: A prospective longitudinal study of fetal peripheral pulmonary artery velocity waveforms from premature rupture of membranes to delivery. SUBJECTS: Twenty pregnancies complicated by premature rupture of membranes before 24 weeks of gestation and delivering after 26 weeks. METHODS: Peripheral pulmonary artery velocity waveforms were recorded by Doppler technique at weekly intervals until delivery and Pulsatility Index (PI) calculated. Pregnancies were managed conservatively according to an institutional management protocol. Pulmonary hypoplasia was defined at autopsy by lung/body weight ratios and radial alveolar counts. Pulsatility Indices of fetuses developing pulmonary hypoplasia were compared with those with a normal lung development. RESULTS: After premature rupture of membranes PI values were higher than normal reference limits for gestation, but no differences were found between the six fetuses which developed pulmonary hypoplasia and the remaining 14 fetuses with normal lung development. In this latter group PI values progressively decreased with advancing gestation (ANOVA for repeated measurements F = 11.61; P < or = 0.001), while they increased in fetuses developing pulmonary hypoplasia (F = 8.44; P < or = 0.001). As a consequence of these opposite trends significant differences in PI values were present between the two groups of fetuses from 2 weeks after the premature rupture of membranes. Two weeks after the premature rupture of membranes a PI value from the peripheral pulmonary arteries above the 95th centile had a sensitivity of 62.5%, specificity of 94.6%, positive predictive value of 83.3%, negative predictive value of 78.5% and relative risk of 3.88 (95th confidence interval 1.34-11.28) for the prediction of pulmonary hypoplasia. CONCLUSION: The measurement of peripheral pulmonary velocity waveforms may help to establish the risk of developing pulmonary hypoplasia in pregnancies complicated by premature rupture of membranes.

Reliability of Pd based dental alloys regarding to corrosion resistance and production processes.

The knowledge of the relationship among chemical composition, microstructure, productive processes, functional properties, quality and price of the final product is an ever greater requirement for the firms producing dental alloys as well as for the dental laboratories making prosthesis. The present study deals with the evaluation of the corrosion resistance of high-Pd and Pd-Ag alloys by quantification of released ions following the recent European regulations suggested. Moreover the reliability of the alloys as far as concern their corrosion resistance was also investigated in relation to the different steps of alloy industrial production and restoration forming processes as well as after homogenization treatments followed by different cooling rate. The very complex microstructure of both alloys was greatly affected by the different casting conditions, deformation rate and thermal treatments used in alloy industrial production and prosthesis manufacturing. However the corrosion resistance of both alloys remained very good in all metallurgical states. The potentiodynamic tests allowed to distinguish among the structural conditions: the homogenization treatments, eliminating segregation inside the different phases, improved further the corrosion resistance of both alloys.

Taurine entry into perilymph of the guinea pig.

Taurine is a beta-aminosulfonic acid and is a ubiquitous amino acid whose role in the cochlea is not well established. In this study, its entry from blood into perilymph was investigated in the guinea pig as animal model. The penetration rate of [3H]taurine (molecular weight 125) into the perilymph of the scala vestibuli was measured 1 and 2 h after the intravenous infusion of [3H]taurine in nephrectomized animals. Results showed a rate of penetration in perilymph related to plasma at 36 +/- 4.7% (n = 5) after 1 h and 43 +/- 5.6% (n = 5) after 2 h. Compared to the penetration rate of urea (molecular weight 60) and mannitol (molecular weight 186) reported previously in rats, a passive entry of taurine into perilymph through the blood-perilymph barrier is suggested.

Ultrasonographic assessment of the uterine cervix and interleukin-8 concentrations in cervical secretions predict intrauterine infection in patients with preterm labor and intact membranes.

OBJECTIVE: Interleukin-8 concentrations in cervical secretions have been related to microbial invasion of the amniotic cavity and histological chorioamnionitis. Since a short uterine cervix may be a risk factor for intrauterine infection, we set out to determine the interrelationship between cervical-secretion interleukin-8 concentration, cervical length measured by transvaginal sonography and intrauterine infection in women with preterm labor and intact membranes. DESIGN: The study group comprised 144 pregnant women admitted to hospital for preterm labor and intact membranes. At admission, interleukin-8 in cervical secretions was assayed. The uterine cervix was evaluated by transvaginal sonography and the cervical index (funnel length + 1)/cervical length) was measured. In all cases, amniotic fluid was obtained by amniocentesis immediately after cervical examination and was cultured for aerobic and anaerobic bacteria including Ureaplasma ureolyticum and Mycoplasma hominis. Placentas were analyzed at delivery for the presence of histological chorioamnionitis. RESULTS: Forty-three per cent (62/144) of pregnancies delivered preterm and 12.5% (18/144) of the amniotic fluid cultures were positive. Placentas were available from 54 pregnancies which delivered preterm and histological chorioamnionitis was found in 59.2% (32/54) of the cases. Interleukin-8 concentrations in cervical secretions were significantly higher in the presence of microbial invasion of the amniotic cavity (median 1191.5 ng/ml, range 812-5234 ng/ml vs. median 109 ng/ml, range 12-2231 ng/ml; p < or = 0.0001) and histological chorioamnionitis (median 982.5 ng/ml, range 430-5234 ng/ml vs. median 435 ng/ml, range 40-1750 ng/ml; p < or = 0.0001). Similarly, higher values for cervical index were obtained in the presence of a positive amniotic fluid culture (median 1.23, range 0.35-5.88 vs. median 0.29, range 0.024-4.85; p < or = 0.0001) or histological chorioamnionitis (median 1.18, range 0.043-5.88 vs. median 0.562, range 0.040-2.48; p = 0.011). Multiple logistic regression analysis indicates significant independent associations with a positive amniotic fluid culture and histological chorioamnionitis for the cervical interleukin-8 concentrations (amniotic fluid culture positive > or = 850, histological chorioamnionitis > or = 450) and for the cervical index (amniotic fluid culture positive < or = 0.58, histological chorioamnionitis < or = 0.56). CONCLUSIONS: Intrauterine infection is associated with increased interleukin-8 concentrations in cervical secretions and a short cervix. Their combined analysis may reduce the indications for invasive procedures and improve the selection of women in preterm labor who may benefit from antimicrobial treatment.