DeepMPTB: a vaginal microbiome-based deep neural network as artificial intelligence strategy for efficient preterm birth prediction

In recent decades, preterm birth (PTB) has become a significant research focus in the healthcare field, as it is a leading cause of neonatal mortality worldwide. Using five independent study cohorts including 1290 vaginal samples from 561 pregnant women who delivered at term (n = 1029) or prematurely (n = 261), we analysed vaginal metagenomics data for precise microbiome structure characterization. Then, a deep neural network (DNN) was trained to predict term birth (TB) and PTB with an accuracy of 84.10% and an area under the receiver operating characteristic curve (AUROC) of 0.875 ± 0.11. During a benchmarking process, we demonstrated that our DL model outperformed seven currently used machine learning algorithms. Finally, our results indicate that overall diversity of the vaginal microbiota should be taken in account to predict PTB and not specific species. This artificial-intelligence based strategy should be highly helpful for clinicians in predicting preterm birth risk, allowing personalized assistance to address various health issues. DeepMPTB is open source and free for academic use. It is licensed under a GNU Affero General Public License 3.0 and is available at https://deepmptb.streamlit.app/ . Source code is available at https://github.com/oschakoory/DeepMPTB and can be easily installed using Docker ( https://www.docker.com/ ).

Feasibility study on using house-tree-person drawings for automatic analysis of depression

Major depression is a severe psychological disorder typically diagnosed using scale tests and through the subjective assessment of medical professionals. Along with the continuous development of machine learning techniques, computer technology has been increasingly employed to identify depression in recent years. Traditional methods of automatic depression recognition rely on using the patient's physiological data, such as facial expressions, voice, electroencephalography (EEG), and magnetic resonance imaging (MRI) as input. However, the acquisition cost of these data is relatively high, making it unsuitable for large-scale depression screening. Thus, we explore the possibility of utilizing a house-tree-person (HTP) drawing to automatically detect major depression without requiring the patient's physiological data. The dataset we used for this study consisted of 309 drawings depicting individuals at risk of major depression and 290 drawings depicting individuals without depression risk. We classified the eight features extracted from HTP sketches using four machine-learning models and used multiple cross-validations to calculate recognition rates. The best classification accuracy rate among these models reached 97.2%. Additionally, we conducted ablation experiments to analyze the association between features and information on depression pathology. The results of Wilcoxon rank-sum tests showed that seven of the eight features significantly differed between the major depression group and the regular group. We demonstrated significant differences in HTP drawings between patients with severe depression and everyday individuals, and using HTP sketches to identify depression automatically is feasible, providing a new approach for automatic identification and large-scale screening of depression.

Top-Down System for Multi-Person 3D Absolute Pose Estimation from Monocular Videos

Two-dimensional (2D) multi-person pose estimation and three-dimensional (3D) root-relative pose estimation from a monocular RGB camera have made significant progress recently. Yet, real-world applications require depth estimations and the ability to determine the distances between people in a scene. Therefore, it is necessary to recover the 3D absolute poses of several people. However, this is still a challenge when using cameras from single points of view. Furthermore, the previously proposed systems typically required a significant amount of resources and memory. To overcome these restrictions, we herein propose a real-time framework for multi-person 3D absolute pose estimation from a monocular camera, which integrates a human detector, a 2D pose estimator, a 3D root-relative pose reconstructor, and a root depth estimator in a top-down manner. The proposed system, called Root-GAST-Net, is based on modified versions of GAST-Net and RootNet networks. The efficiency of the proposed Root-GAST-Net system is demonstrated through quantitative and qualitative evaluations on two benchmark datasets, Human3.6M and MuPoTS-3D. On all evaluated metrics, our experimental results on the MuPoTS-3D dataset outperform the current state-of-the-art by a significant margin, and can run in real-time at 15 fps on the Nvidia GeForce GTX 1080.

Influence of cardiac phase on myocardial native T1 values by a segmental approach

Funding Acknowledgements

Type of funding sources: None.

Background. Native T1 values are usually assessed in the end-diastole to minimize motion artifacts while the systolic data acquisition offers the advantage of a thicker myocardium, with reduced partial-volume effects. Higher myocardial T1 values have been detected in diastole at both 1.5T and 3T but the dependence of this difference on myocardial segments or gender has not been fully explored.

Aim. We provided a systematic comparison of myocardial native T1 values in diastole and systole, by considering separately myocardial segments and dividing males and females.

Methods. Sixty-one healthy subjects (46.0 ± 14.1 years, 32 males) underwent CMR at 1.5T (Signa Artist; GE Healthcare). Three short-axis slices of the left ventricle acquired in diastole and systole using a Modified Look–Locker Inversion Recovery sequence. Image analysis was performed with a commercially available software package. T1 value was assessed in all 16 myocardial segments and global value was the mean.

Results. Table 1 shows the comparison between T1 values calculated from maps obtained in diastole and systole. Systolic T1 values were significantly lower in the basal anterolateral segment, in all medium segments except for the medium inferior segment, and in all apical segments. The percentage difference between diastolic and systolic T1 values was considered to compensate for the higher T1 values in females, and a significantly higher value was detected in females for the majority of medium segments, for all apical segments, and for the global value.

Conclusion. The diastolic-systolic discrepancy was more pronounced for the females and at the apical level, supporting the hypothesis that, besides the physiologic variations in myocardial blood volume during the cardiac cycle, the partial volume-effect may be a strong additional contributing factor. Native T1 values should be obtained always in the same cardiac phase to avoid a potential bias in the discrimination between healthy and pathologically affected myocardium.

The dark side of centromeres: types, causes and consequences of structural abnormalities implicating centromeric DNA

Centromeres are the chromosomal domains required to ensure faithful transmission of the genome during cell division. They have a central role in preventing aneuploidy, by orchestrating the assembly of several components required for chromosome separation. However, centromeres also adopt a complex structure that makes them susceptible to being sites of chromosome rearrangements. Therefore, preservation of centromere integrity is a difficult, but important task for the cell. In this review, we discuss how centromeres could potentially be a source of genome instability and how centromere aberrations and rearrangements are linked with human diseases such as cancer.

Social laughter is correlated with an elevated pain threshold

Although laughter forms an important part of human non-verbal communication, it has received rather less attention than it deserves in both the experimental and the observational literatures. Relaxed social (Duchenne) laughter is associated with feelings of wellbeing and heightened affect, a proximate explanation for which might be the release of endorphins. We tested this hypothesis in a series of six experimental studies in both the laboratory (watching videos) and naturalistic contexts (watching stage performances), using change in pain threshold as an assay for endorphin release. The results show that pain thresholds are significantly higher after laughter than in the control condition. This pain-tolerance effect is due to laughter itself and not simply due to a change in positive affect. We suggest that laughter, through an endorphin-mediated opiate effect, may play a crucial role in social bonding.

An incidental finding of breast cancer after breast injury

We report of a 52-year-old woman presenting with a breast palpable mass after a trauma due to accidental fall. The patient came to our attention to perform an ultrasonographic examination because of the persistence of the mass after the trauma. The exam showed an hypo-anechoic oval formation with blurred margins and no vascularization at Power Doppler, located to the union of the upper quadrants of the right breast. The patient also performed mammographic examination, which showed an unknown oval radiopaque area. The findings were consistent with post-traumatic hematoma, even in relation to the anamnestic data, therefore we recommended anti-inflammatory therapy and a new check in fifteen days. The next ultrasonographic examination showed the persistence of the mass, slightly reduced in size, so we tried to achieve a more detailed diagnosis by performing MRI; however, the diagnostic doubt still remained, so we decided to perform a US-guided core-biopsy: the histological diagnosis was infiltrating ductal carcinoma of the breast. A review of the literature confirmed that breast lesions often are incidental findings after a breast trauma.

Cortical surface mapping using topology correction, partial flattening and 3D shape context-based non-rigid registration for use in quantifying atrophy in Alzheimer's disease

Magnetic resonance (MR) provides a non-invasive way to investigate changes in the brain resulting from aging or neurodegenerative disorders such as Alzheimer's disease (AD). Performing accurate analysis for population studies is challenging because of the interindividual anatomical variability. A large set of tools is found to perform studies of brain anatomy and population analysis (FreeSurfer, SPM, FSL). In this paper we present a newly developed surface-based processing pipeline (MILXCTE) that allows accurate vertex-wise statistical comparisons of brain modifications, such as cortical thickness (CTE). The brain is first segmented into the three main tissues: white matter, gray matter and cerebrospinal fluid, after CTE is computed, a topology corrected mesh is generated. Partial inflation and non-rigid registration of cortical surfaces to a common space using shape context are then performed. Each of the steps was firstly validated using MR images from the OASIS database. We then applied the pipeline to a sample of individuals randomly selected from the AIBL study on AD and compared with FreeSurfer. For a population of 50 individuals we found correlation of cortical thickness in all the regions of the brain (average r=0.62 left and r=0.64 right hemispheres). We finally computed changes in atrophy in 32 AD patients and 81 healthy elderly individuals. Significant differences were found in regions known to be affected in AD. We demonstrated the validity of the method for use in clinical studies which provides an alternative to well established techniques to compare different imaging biomarkers for the study of neurodegenerative diseases.

Bacterial community changes during bioremediation of aliphatic hydrocarbon-contaminated soil

The microbial community response during the oxygen biostimulation process of aged oil-polluted soils is poorly documented and there is no reference for the long-term monitoring of the unsaturated zone. To assess the potential effect of air supply on hydrocarbon fate and microbial community structure, two treatments (0 and 0.056 mol h⁻¹ molar flow rate of oxygen) were performed in fixed bed reactors containing oil-polluted soil. Microbial activity was monitored continuously over 2 years throughout the oxygen biostimulation process. Microbial community structure before and after treatment for 12 and 24 months was determined using a dual rRNA/rRNA gene approach, allowing us to characterize bacteria that were presumably metabolically active and therefore responsible for the functionality of the community in this polluted soil. Clone library analysis revealed that the microbial community contained many rare phylotypes. These have never been observed in other studied ecosystems. The bacterial community shifted from Gammaproteobacteria to Actinobacteria during the treatment. Without aeration, the samples were dominated by a phylotype linked to the Streptomyces. Members belonging to eight dominant phylotypes were well adapted to the aeration process. Aeration stimulated an Actinobacteria phylotype that might be involved in restoring the ecosystem studied. Phylogenetic analyses suggested that this phylotype is a novel, deep-branching member of the Actinobacteria related to the well-studied genus Acidimicrobium.

Evaluation of automated brain MR image segmentation and volumetry methods

We compare three widely used brain volumetry methods available in the software packages FSL, SPM5, and FreeSurfer and evaluate their performance using simulated and real MR brain data sets. We analyze the accuracy of gray and white matter volume measurements and their robustness against changes of image quality using the BrainWeb MRI database. These images are based on "gold-standard" reference brain templates. This allows us to assess between- (same data set, different method) and also within-segmenter (same method, variation of image quality) comparability, for both of which we find pronounced variations in segmentation results for gray and white matter volumes. The calculated volumes deviate up to >10% from the reference values for gray and white matter depending on method and image quality. Sensitivity is best for SPM5, volumetric accuracy for gray and white matter was similar in SPM5 and FSL and better than in FreeSurfer. FSL showed the highest stability for white (<5%), FreeSurfer (6.2%) for gray matter for constant image quality BrainWeb data. Between-segmenter comparisons show discrepancies of up to >20% for the simulated data and 24% on average for the real data sets, whereas within-method performance analysis uncovered volume differences of up to >15%. Since the discrepancies between results reach the same order of magnitude as volume changes observed in disease, these effects limit the usability of the segmentation methods for following volume changes in individual patients over time and should be taken into account during the planning and analysis of brain volume studies.

PhylArray: phylogenetic probe design algorithm for microarray

MOTIVATION

Microbial diversity is still largely unknown in most environments, such as soils. In order to get access to this microbial 'black-box', the development of powerful tools such as microarrays are necessary. However, the reliability of this approach relies on probe efficiency, in particular sensitivity, specificity and explorative power, in order to obtain an image of the microbial communities that is close to reality.

RESULTS

We propose a new probe design algorithm that is able to select microarray probes targeting SSU rRNA at any phylogenetic level. This original approach, implemented in a program called 'PhylArray', designs a combination of degenerate and non-degenerate probes for each target taxon. Comparative experimental evaluations indicate that probes designed with PhylArray yield a higher sensitivity and specificity than those designed by conventional approaches. Applying the combined PhyArray/GoArrays strategy helps to optimize the hybridization performance of short probes. Finally, hybridizations with environmental targets have shown that the use of the PhylArray strategy can draw attention to even previously unknown bacteria.

Transcranial Magnetic Stimulation : Magnetic Field Computation in empty free space

Transcranial Magnetic Stimulation (TMS) is a technique for brain stimulation using magnetic field generated by an external coil. As another techniques like ECT or the implantation of electrodes into motor cortex, TMS has several applications in medical and clinical research. The main benefit of TMS is to be non invasive and painless. TMS use increases but stimulation process remains still empirical and pratician has to perform several stimulations to find the best coil position/direction. We propose to develop a simulator of transcranial magnetic stimulation which aims at computing the electromagnetic field induced in the cortex by TMS. We present in this article the first step of this tool, a parametrical coil model allowing the computation of potential magnetic field outside the head and some way to represent it.

Synthesis of a functional information with anatomical landmarks by multiresolution fusion of brain images

In order to help clinicians with the diagnosis of neurodegenerative diseases, we provide a synthetic functional information located in relation with anatomical structures. The final image is processed by multimodal data fusion between SPECT and MR images. We propose a new method for the management of such multiresolution data, in which a geometrical model allows an accurate correspondence of voxels from both images, while preserving at best both original pieces of information. We use this matching method to replace the interpolation step in the compulsory image registration of the data fusion process. The geometrical model is first built from registration parameters. Computational geometry algorithms, applied to this model, allow the computation of numerical values used to process the final information. The method has been applied to brain perfusion and neurotransmission SPECT images.

Oxidized low density lipoproteins induce apoptosis in human lymphocytes: involvement of mitogen-activated protein kinases

Oxidized low density lipoproteins (oxLDL), macrophages and T-lymphocytes are present in atherosclerotic lesions. We and others have shown that oxLDL is cytotoxic for macrophages, endothelial, smooth muscle and activated T-lymphocytes and induce apoptosis. Here we demonstrate that (i) oxidized LDL (oxLDL), oxidized VLDL (oxVLDL) and hydrogen peroxide (H2O2) induce apoptosis in human T-lymphocytes and (ii) mitogen-activated protein kinases are involved in this process. Apoptosis was monitored by immunofluorescence microscopy and flow cytometry for annexin V binding, Apo 2.7 expression, the TUNEL reaction and caspase 3 activity. In the presence of oxLDL (100 microg/ml), oxVLDL (50 microg/ml) and H2O2 (5 mM), the fraction of apoptotic cells increased within 6 hours to more than 70%. Preincubation of lymphocytes with the MAPKK inhibitor PD-98059 and the p38MAPK inhibitor SB-203580 almost completely abolished these effects. Furthermore, oxLDL and H2O2 but not native LDL strongly enhanced phosphorylation of JNK, p38MAPK and p42/44MAPK. The results suggest that in the resting lymphocyte apoptosis triggered by oxidized lipoproteins and oxidative stress depends on the activation of p44/42MAPK and p38MAPK cascades.

Robust segmentation and analysis of DNA microarray spots using an adaptative split and merge algorithm

Microarray images push to their limits classical analysis methods, since gene spots are often poorly contrasted, ill defined and of irregular shapes. These characteristics hinder a robust quantification of corresponding values for red and green intensities as well as their R/G ratio. New approaches are thus needed to ensure accurate data extraction from these images. Herein we present an automatic non-supervised algorithm for a fast and accurate spot data extraction from DNA microarrays. The method is based on a split and merge algorithm, relying on a Delaunay triangulation process, allowing an incremental partition of the image into homogeneous polygons. Geometric properties of triangles as well as homogeneity criteria are defined according to the specificities of microarray image signals. The method is first assessed on simulated data, and then compared with GenePix and Jaguar Softwares. Results in segmentation and quantification are superior to those obtained from a number of standard techniques for spot extraction.

Analysis of gene expression data using functional principal components

The large amount of data involved in DNA microarrays implies the development of efficient computer algorithms to analyze the gene expressions, and thus to study the transcriptome. Numerous techniques already exist and we propose a new method based on the key idea that gene profiles may be considered as continuous curves. The analysis of the set of curves stemming from the DNA microarray may be then performed using a functional analysis which can exhibit the main modes of variations in this set, gather genes with similar variations and extract characteristic parameters of gene profiles. We aim here at introducing this method, called the Functional Principal Component Analysis. A prospective study has been performed on two available datasets, concerning on the one hand the sporulation data of the Saccharomyces cerevisiae, and on the other hand data of tumor cell lines. Results are very promising: the method is able to extract characteristic parameters from the datasets, to extract significant modes of variations in the set of gene profiles, and to link these variations to biological processes already studied in literature.

Extraction of epileptogenic foci from PET and SPECT images by fuzzy modeling and data fusion

During the presurgical evaluation of medically intractable epilepsy, isotopic functional imagery provides an increasing amount of data concerning the potential location of the focus. The aim of this study is to facilitate the surgical decision by presenting an image fusion method able to extract epileptogenic foci from periictal single photon emission computed tomography (SPECT), interictal SPECT, fluoro-desoxy-glucose (FDG) position emission tomography (PET), and flumazenil PET. After spatial coregistration, the images are converted into fuzzy maps whose membership functions indicate the pathological degree of each voxel, according to each modality. These maps are then fused together thanks to a combination operator managing uncertainty (due to the sensitivity) and imprecision (due to poor resolution and partial volume effect) of the images. In the framework of possibilistic theory, this operator mimics the way the physicians evaluate and compare the various exams. The technique was successfully tested on simulated images with well-defined abnormalities, in terms of size and intensity. A preliminary clinical study was also performed and gave results in accordance with the "gold standard" investigation (deep electrodes or postsurgical outcome) in 11 patients out of 12.

Effects of two electrical stimulation frequencies in thigh muscle after knee surgery

The purpose of this study was to compare the effects of two protocols of electrical stimulation combined with voluntary contractions on the recovery of thigh muscles after anterior cruciate ligament (ACL) surgery. Ten sportsmen with a mean age of 26 yrs were randomly assigned into two groups: a 80 Hz stimulated group (5 patients) and a 20 Hz stimulated group (5 patients). All patients received electrical stimulation of the quadriceps femoris, five days a week, for 12 weeks, and had a standard program of voluntary contractions. Muscle and fat volumes of the thigh were assessed using MRI before surgery and after 12 weeks of rehabilitation. Quadriceps and hamstring muscle strength were evaluated by isokinetic measurements. Twelve weeks after surgery, the quadriceps peak torque deficit in the operated limb with respect to the non operated limb at 180 degrees /s and 240 degrees /s was significantly (p < 0.05) less in the 20 Hz group than in the 80 Hz group. This difference was not confirmed when comparing the pre-surgery quadriceps peak torque of the operated limb with the post-surgery one. Subcutaneous fat volume was increased for the two groups at the post-surgery test. This increase was significantly (p < 0.05) greater for the 80 Hz group. Thigh muscle volume deficit was not significantly different between the two groups.

Glandular kallikreins in the teleost Cyprinus carpio: tissue distribution, possible involvement in prolactin processing, and effect of 17 beta-estradiol in vivo

We examined glandular kallikrein (GK), a putative prolactin processing protease, in the teleost Cyprinus carpio. When employing an anti-Centropristis striata GK antibody proteins of 39 kDa in muscle, 52 kDa in gill, 52 kDa in kidney, and two proteins of 46 and 72 kDa in pituitary gland were detected. Immunoreactive kallikreins were recognized in intermuscle cell tissue, epithelial gill cells, apical region of tubular cells, and prolactin producing lactotrophs in pituitary gland, suggesting a osmoregulatory role for this enzyme. We found three prolactin (PRL) variants using anti-tilapia PRL antibodies, in pituitary gland 23 and 16 kDa, and in plasma 23 and 22 kDa forms. Clearly co-localization of GK and PRL in lactotrophs could be demonstrated. In winter-acclimatized male carp, where the pituitary PRL level is low, 17beta-estradiol treatment increased PRL but not GK immunoreactivity. In contrast to GK and PRL co-regulation by estrogen in mammalian pituitary gland, no similar effect on immunoreactive PRL and GK was observed in the ichtyc pituitary. No changes in GK immunostaining occurred in gill or muscle tissue in response to estrogen treatment. These results, taken with the observation of significantly increased GK immunoreactivity in the apical region of kidney tubular cells in estrogen treated male carp, indicate that the regulation of GK expression in pituitary and kidney could be different in fish with respect to mammals.

Segmentation of fat and muscle from MR images of the thigh by a possibilistic clustering algorithm

Physical training is proved to induce changes in physical capacity and body composition. We propose in this article a fast, unsupervised and fully three-dimensional automatic method to extract muscle and fat volumes from magnetic resonance images of thighs in order to assess these changes. The technique relies on the use of a fuzzy clustering algorithm and post-processings to accurately process the body composition of thighs. Results are compared on 11 healthy voluntary elderly people with those provided on the same data by a validated method already published, and its reliability is assessed on repeated measures on three subjects. The two methods statistically agree when computing muscle and fat volumes, and clinical implications of this fully automatic method are important for medicine, physical conditioning, weight-loss programs and predictions of optimal body weight.

Fusion in medical imaging: theory, interests and industrial applications

The accumulation of several data coming from medical images and signals, expert knowledge and databases is becoming very common for the study of a given pathology. The aggregation of all this information is mentally performed by a clinician, and generally allows for a better medical decision in clinical studies. We propose in this article a fusion method that models this aggregation process. This method is a three step scheme, that first transforms all the available information in a common theoretical frame, then aggregates these data using their redundancy and their conflicts, and finally computes a new information synthesizing all the initial knowledge. We first introduce in this article the fusion scheme and its theoretical aspects, and we particularly focus on the three steps of the process. We then detail the software implementation of this concept, achieved in collaboration with SEGAMI Corporation Inc. We finally apply this concept to a real clinical problem, the study of Alzheimer's disease using MR and SPECT images, and we show very encouraging preliminary results.

Automatic volumetric measurement of lateral ventricles on magnetic resonance images with correction of partial volume effects

PURPOSE

To propose a method for the quantification of lateral ventricle (LV) volumes on a single sequence of 3D magnetic resonance (MR) images.

MATERIALS AND METHODS

This algorithm, following a preliminary fuzzy tissue classification step, is based on the development of mathematical morphology processes allowing both the extraction of the LVs and the correction of partial volume effects on their boundaries. The procedure is fast and totally unsupervised. The method is tested on a phantom image, then applied to five patients diagnosed as potentially suffering from Alzheimer's disease, and finally applied on several MR acquisitions to show the genericness of the algorithm.

RESULTS AND CONCLUSION

This technique yielded both an accurate estimation of ventricular volumes intra- and intersubject with respect to published data and a relevant management of partial volume effects. Numerous clinical applications are now expected, from the study of schizophrenia to the longitudinal follow-up of Alzheimer's patients.

Vasopressin stimulates tyrosine phosphorylation by activation of PKC in the rat smooth muscle cell line, A-10

Arginine vasopressin (AVP)-induced tyrosine phosphorylation was studied in a rat smooth muscle cell line, A-10, by western blotting, using a monoclonal antibody against phosphotyrosine. AVP stimulated the phosphorylation of several cellular proteins of molecular mass 60-130 kDa in a time- and dose-dependent manner. Phosphorylation was mediated largely by V(1)receptor subtype since it was inhibited by selective V(1)antagonist and was only partially elicited by the V(2)agonist, desmopressin. Heterotrimeric G-proteins seemed to be involved in the phosphorylation mechanism because fluoraluminates, an activator of heterotrimeric G-proteins (and thus an uncoupler of the receptor-G-protein interaction) inhibited the AVP-induced phosphorylation. The protein kinase C (PKC) inhibitors: staurosporine, H7 and GF109203X are able to block the AVP-stimulated phosphorylation. The last of these has been shown to be one of the most selective inhibitors of PKC. These results indicate that PKC is upstream of the phosphorylation, a motion which is supported by the fact that the AVP-stimulated phosphorylation was downregulated by phorbol esters.

Automatic segmentation of subcortical brain structures in MR images using information fusion

This paper reports a new automated method for the segmentation of internal cerebral structures using an information fusion technique. The information is provided both by images and expert knowledge, and consists in morphological, topological, and tissue constitution data. All this ambiguous, complementary and redundant information is managed using a three-step fusion scheme based on fuzzy logic. The information is first modeled into a common theoretical frame managing its imprecision and incertitude. The models are then fused and a decision is taken in order to reduce the imprecision and to increase the certainty in the location of the structures. The whole process is illustrated on the segmentation of thalamus, putamen, and head of the caudate nucleus from expert knowledge and magnetic resonance images, in a protocol involving 14 healthy volunteers. The quantitative validation is achieved by comparing computed, manually segmented structures and published data by means of indexes assessing the accuracy of volume estimation and spatial location. Results suggest a consistent volume estimation with respect to the expert quantification and published data, and a high spatial similarity of the segmented and computed structures. This method is generic and applicable to any structure that can be defined by expert knowledge and morphological images.

A general framework for the fusion of anatomical and functional medical images

The collection of various data coming from anatomical and functional imagery is becoming very common for the study of a given pathology, and their aggregation generally allows for a better medical decision in clinical studies. A fusion process is described in this article for the modeling of this aggregation. The process is illustrated in the case of anatomical and functional images of the brain, but the general principle may be extended to other organs. The whole three-step fusion process based on possibilistic logic is detailed and a new class of fusion operator is introduced. The use of fuzziness in the process in general and in the operator in particular allows for the management of uncertainty and imprecision inherent to the images. The fusion process is illustrated in two clinical cases: the study of Alzheimer's disease by MR/SPECT fusion and the study of epilepsy by MR/SPECT/PET fusion. Results are presented and evaluated, and a preliminary clinical validation is achieved. The assessment of the method is encouraging, allowing its application on several clinical problems.

Peroneus brevis tendon transfer in neglected tears of the Achilles tendon

BACKGROUND

We present the results of a single-center, single-surgeon study in 59 patients with a fresh (4 women and 23 men; mean age, 43.6 +/- 8.8 years) or a neglected (1 woman and 21 men; mean age, 41.3 +/- 7.4 years) Achilles tendon rupture.

METHODS

Patients with a fresh rupture were operated on using end-to-end suture, and patients with a neglected rupture received the tendon of the peroneus brevis as an autologous graft. Patients were assessed during the sixth postoperative week, and during the sixth postoperative month. They were discharged within 1 year after the operation, and were reviewed at an average of 53 +/- 13 months after surgery.

RESULTS

Patients were generally satisfied with the procedure, but those with a neglected rupture tended to have a greater postoperative complication rate, greater loss of isokinetic strength variables at high speeds, and greater loss of calf circumference.

CONCLUSION

The management of acute and neglected subcutaneous tears of the Achilles tendon by peroneus tendon transfer is safe but technically demanding. It affords good recovery, even in patients with a neglected rupture of 6 weeks' to 9 months' duration. Patients with a neglected rupture are at a slightly greater risk of postoperative complications, and their ankle plantar flexion strength can be reduced.

Giant cell tumour of the hamate. Case report

We report the case of a 31-year-old woman who had had the distal end of the ulna resected for a giant cell tumour five years before presenting with a further one in the hamate. The medullary cavity of the hamate was curetted and cancellous bone grafted from the distal radius. Her symptoms resolved, and 26 months postoperatively the cortex of the hamate was fully restored.

Benefit of endurance training in elderly people over a short period is reversible

The present study assessed daily activity, physical capacity and body composition in 11 initially sedentary healthy subjects [5 men and 6 women, mean age 62.8 (SD 2.7) years] before training (T(o)), after completion of 7 (T(7w)) and 14 (T(14w)) weeks of training, and again 6 (T(6m)) and 12 (T(12m)) months after training. The mean daily activity index decreased from T(7w) to T(12m) reaching a lower level than at T(o) [T(12m) - T(o) = -1.5 (SD 4.6) units, P = 0.18]. Mean maximal oxygen uptake (VO(2max)) and its corresponding mean power output (Wdot(max)) were increased by 12.5 (SD 6.6)% (P = 0. 003) and 22.8 (SD 12.8)% (P = 0.003), respectively, at T(14w), and returned to their T(o) levels within 1 year. Mean body mass (m(b)) remained stable until T(6m) but increased significantly by 2.6 (SD 3. 7)% from T(6m) to T(12m) (P < 0.05). Mean fat mass (m(f), from bioelectrical impedance analysis measurements) tended to decrease [-2.0 (SD 4.2)%, P = 0.10] during the training period but increased by 7.8 (SD 10.9)% between T(6m) and T(12m) (P < 0.05). The mean fat free mass did not vary during the study period (P = 0.81) but magnetic resonance imaging (MRI) showed that mean thigh muscle volume decreased between T(7w) and T(12m) to less than at T(o) [T(12m) - T(o) = -2.3 (SD 3.6)%, P = 0.05]. Therefore, this study confirmed the favourable effects of endurance training on the physical capacity and body composition of elderly people, but demonstrated that the training programme would have to be continued to maintain the training-related benefits (i.e. increased VO(2max) and Wdot(max)) which would otherwise be lost within 1 year. After training, m(b) and m(f) were found to be increased. Furthermore, a fast and reproducible MRI protocol was validated for study of small intra-individual variations in tissue volumes in longitudinal studies.

Tissue segmentation on MR images of the brain by possibilistic clustering on a 3D wavelet representation

An algorithm for the segmentation of a single sequence of three-dimensional magnetic resonance (MR) images into cerebrospinal fluid, gray matter, and white matter classes is proposed. This new method is a possibilistic clustering algorithm using the fuzzy theory as frame and the wavelet coefficients of the voxels as features to be clustered. Fuzzy logic models the uncertainty and imprecision inherent in MR images of the brain, while the wavelet representation allows for both spatial and textural information. The procedure is fast, unsupervised, and totally independent of any statistical assumptions. The method is tested on a phantom image, then applied to normal and Alzheimer's brains, and finally compared with another classic brain tissue segmentation method, affording a relevant classification of voxels into the different tissue classes.

[D/D genotype of the gene for angiotensin converting enzyme as a risk factor for post-stent coronary restenosis]

INTRODUCTION

Although intracoronary stenting has decreased restenosis rate compared to percutaneous balloon angioplasty, still a high number of patients develop in-stent restenosis, which is an entity primarily due to tissue proliferation. Experimental studies have indicated that the renin-angiotensin system is involved in neointimal hyperplasia. Plasma and cellular levels of ACE are associated with an I/D polymorphism in the ACE gene. Indeed, DD subjects have the higher ACE levels. The purpose of this study was to explore the possibility that the I/D polymorphism might be related with in-stent restenosis.

METHODS

We studied the ACE polymorphism in 48 consecutive patients who underwent successful implantation of an elective coronary stent in native coronary vessels and had a 6 month angiographic follow up. Restenosis (50% of the reference vessel) was observed in 23/48 patients. Patients with or without restenosis did not differ in demographic or clinical variables like diabetes, plasma cholesterol levels or in quantitative angiographic parameters such as vessel reference size or minimal lumen diameter after stent implantation.

RESULTS

I/D polymorphism was distributed as follows: 22.9% of the patients were D/D; 14.5% were I/I and 62.5% of the patients were heterozygous I/D. The presence of restenosis was strongly related with the I/D polymorphism: 81.8% of the patients with D/D genotype had restenosis, compared with 40.0% of I/D patients and only 14.2% of the I/I patients (chi 2 p < 0.01).

CONCLUSIONS

In this limited cohort, homocygous D/D of the ACE gene was significantly associated with in-stent restenosis, whereas restenosis was infrequent in patients with the I/I genotype.

[Clinico-radiologic considerations on "stress fractures" of the leg]

Stress fractures are ubiquitary and most often caused by the subject's activities. In the past they occurred mostly in recruits, but today they are frequent in sportsmen. Stress fractures most frequently occur in the lower limbs, especially in the distal leg. We reviewed 32 injuries observed January, 1993, to June, 1995, and found that 25% of them had been misdiagnosed as stress fractures: in the cases where the diagnosis was correct, fatigue fractures (32%) were less frequent than insufficiency fractures (68%) and occurred in young subjects (mean age: 24 years), usually sportsmen (2/3 of cases). Insufficiency fractures may occur in people aged 8 to 81 years (mean: 61 years) and in subjects with metabolic disorders (45.5%). Considering the injury biomechanics and the patient history and symptoms, these lesions appear a rather uncommon event, whose radiologic diagnosis must be confirmed by clinical findings, since radiology mostly (81.6% of cases) showed only the repair process, rather than the fracture itself. The radiologic patterns were classified into three groups: the fracture margin was not shown in 70% of cases (group I), where however intraperiosteal reaction and/or soft tissue effusion were found; bone fracture was shown in 3 cases (group II) and fracture sequels in 4 (group III), where bone thickening (3 cases) or abnormal consolidation (1 case) was found. There are several synonyms of "stress fracture" and confusion is increased because stress lines and other not necessarily abnormal signs such as Park or Harris lines, reinforcement or calcification lines, are often grouped together with stress fractures. Only accurate clinical examination and laboratory findings permit to distinguish fatigue from insufficiency stress fractures and the latter are also very difficult to differentiate from pathologic fractures. The differentiation of fatigue from insufficiency fractures, originally made by English speaking authors, may be confusing because the definition "pathologic fractures" should be reserved only to focal injuries while in the past it included also insufficiency fractures. Thus, only (bone) fatigue injuries in patients exercising intensely and constantly should be considered stress fractures. Conventional radiography is an indispensable tool and MRI is used in selected cases where the former method is negative and in the patients needing early mobility to go back to work. If radiographic findings are questionable for metastases, nuclear medicine is the method of choice and CT and/or MRI may be indicated as second-line diagnostic imaging tools.

alpha-Melanocyte-stimulating hormone during human perinatal life

To obtain information on human pituitary intermediate lobe activity throughout the perinatal period, plasma alpha MSH immunoreactivity (IR) was measured in 106 newborns at delivery and during the first week of postnatal life. Subjects were divided into groups according to gestational age at birth, mode of parturition, and antenatal state of health. Plasma alpha MSH IR decreased progressively from severe preterm to fullterm neonates born by vaginal delivery (VD; P < 0.001) or cesarean section (CS) with and without prenatal distress (P < or = 0.001 in both cases). alpha MSH IR was due, in all studied conditions, to three major forms: desacetyl alpha MSH, alpha MSH, and diacetyl alpha MSH. Desacetyl alpha MSH was always the most represented form, but it decreased from 75-80% of the total in severe premature to 40-45% in mature infants. In term neonates, total alpha MSH IR values were higher in subjects born by normal VD than by elective CS (P < or = 0.05), in complicated than in normal VD (P < or = 0.01), and in CS performed because of fetal distress than in elective CS (P < or = 0.01). No significant difference was detectable in mature subjects in the percentages of the three alpha MSH forms in relation to the mode of delivery and fetal state during antenatal life or at parturition. Twelve hours after birth, total alpha MSH IR significantly decreased in all groups of term newborns, reaching a plateau of 0.8-1.4 pmol/L. In premature infants, similar concentrations were detectable by the fourth postnatal day. We conclude that 1) alpha MSH IR intermediate lobe secretion progressively decreases throughout the third trimester of pregnancy; 2) stress, including that pertinent to parturition, stimulates alpha MSH IR release; and 3) pituitary intermediate lobe activity declines shortly after birth independently of the maturity reached by the fetus, the mode of parturition, and the presence of antenatal chronic distress, although the process is slightly retarded in premature newborns.

Identification of the V1 vasopressin receptor by chemical cross-linking and ligand affinity blotting

Chemical and photoaffinity cross-linking experiments as well as ligand affinity blotting techniques were used to label the V1 vasopressin receptor. In order to determine the optimal reaction conditions, pig liver membranes were incubated with 5 nM [8-lysine]vasopressin (LVP) labeled with 125I and then cross-linked with the use of DMS (dimethyl suberimidate), EGS [ethylene glycol bis(succinimidyl succinate)] or HSAB (hydroxysuccinimidyl p-azidobenzoate) at different final concentrations. Consistently, EGS was found to label with high yield one band of Mr 60,000 in rat and pig liver membranes when used at a final concentration between 0.05 and 0.25 mM. The protein of Mr 60,000 is labeled in a concentration-dependent manner when pig liver membranes are incubated with increasing concentrations of 125I-LVP and then cross-linked with EGS. The label was displaced by increasing concentrations of unlabeled LVP or d(CH2)5 [Tyr2(Me),-Tyr9(NH2)]AVP (V1/V2 antagonist). A protein band of similar molecular mass was cross-linked with 125I-LVP in rat liver membranes. The reaction was specific since the incorporation of label into the protein of Mr 60,000 was inhibited by LVP, [8-arginine]vasopressin (AVP), the V1/V2-antagonist, and the specific V1-antagonist d(CH2)5 [Tyr2(Me)]AVP, only partially by [des-Gly9]AVP (V2-agonist) and by oxytocin, and not at all by angiotensin II. Incubation of nitrocellulose containing membrane proteins from pig liver with 125I-LVP showed the labeling of a band of Mr 58,000 that is inhibited by an excess of unlabeled LVP. This band of Mr 58,000 seems to correspond with the protein of Mr 60,000 revealed by the cross-linking experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

[The usefulness of endoscopic polypectomy of rectosigmoid and colon in childhood]

Rectal polyps are relatively frequent in infancy and constitute one of the main causes of hematoquezia during this time of life. They are usually treated with multiple drugs before the correct diagnosis is made. We report our experiences with the use of rectoscopy and colonoscopy for the diagnosis and treatment of 214 patients with rectosigmoid polyps, including other sites in the colon, studied between 1982-1988. The highest incidence was between 3 and 6 years of age (63.8%), and the most frequent location in 253 rectosigmoid polyps (91%) and histologically (99.7%) were juvenile polyps. Endoscopic polypectomy proved to be a valuable method, easy to perform and with few complications to treat colon polyps, thus eliminating the surgical interventions.

[Achalasia in children]

Achalasia is a pathology which was first described more than 300 years ago, it is relatively rare in children. Four cases of childhood achalasia were studied in children admitted to the J. M. de los Ríos Hospital during the period January, 1971 to June, 1990. The clinical presentation was characterized by progressive dysphagia to solids and liquids, regurgitations, weight loss and in certain cases, a moist cough, predominantly nocturnal. The diagnostic workup carried out included radiological, endoscopic and manometric studies. They were helpful to diagnose the following positive signs: esophageal dilation with alteration of motility and a small caliber cardio-esophageal junction, in addition to an elevation of the inferior esophageal sphincteric pressure with non-peristaltic esophageal contractions. The Starck dilator was used to create a mechanical disruption of the muscle fibers of the inferior esophageal sphincter. The procedure improved the clinical symptoms, lowered the inferior esophageal sphincteric pressure leading to adequate pondostatural progress and a satisfactory evolution.

[Biliary ascaridiasis in children. Ultrasonic diagnosis]

Ascariasis is one of the most frequent intestinal parasitosis of man, specially in tropical regions where it affects mostly children. The adult worm can migrate through the ampulla of vater and penetrate the bile ducts producing different degrees of obstruction and infection. Ultrasonography is a rapid and simple non invasive procedure very effective for the visualization of the worm in the biliary tree. We present the clinical and ultrasonographic characteristic of biliary ascariasis in five children diagnosed by ultrasonography in our institution during the last nine years.

[Theoretical and practical aspects of globular sedimentation velocity]

The following methods used to determine globular sedimentation rate (VSG) were reviewed: Westergren and Wintrobe techniques, Chattas micromethod, Sibora and Sediplast systems and z percentage sedimentation. Also included are the VSG phases and those factors which determine the aggregation of the red corpuscles whether they be plasmatic, globular or extrinsic.

[Modified erythrocyte sedimentation rate. Study in pre-school and school children]

The Westergren inclined technique can be used to determine the globular sedimentation rate (GSR) at 10 and 15 minutes which are equivalent to the first and second hours respectively of the classic method. The present study compares GSR correlations using both methods, on a sample of 64 healthy children, included according to predetermined study selection criteria. The sample included 38 preschoolers (59.37%) and 26 school children (48.63%); with an age range between 4.14 +/- 0.48 years and 8.68 +/- 0.62 years (mean +/- 2 EE) respectively. The hematocrit range was between 38.75 +/- 0.56 Vol%; no erythrocyte alterations were observed. A significant positive correlation was observed in the GSR determinations between 1 hour-10 min and 2 hours-15 min, which were r1 = 0.9049 (P less than 0.001) and r2 = 0.9404 (P less than 0.001). No significant difference (P greater than 0.05) was noted on the basis of sex (34 males, 30 females). The determinations taken with the Westergren inclined method proved superior to the classic method, but the technique requires the inclusion of normal values of the former. The conclusion is that the inclined method can be used and interpreted by the clinician in the same way as the classic Westergren method. It permits a time saving, which in large hospital practices implies an important economic factor.

[Usefulness of colonoscopy in the diagnosis of colonic diseases in childhood]

We present here our experience in colonoscopy performed in 93 children between 1984-1988 at hospital J. M. de los Ríos de Caracas. Mean age was 5.44 y/o and the range was 2-13 y/o. Rectal bleeding in 91.36% of the cases was the most common indication of the procedure. Rectal and sigmoid polyps were found in 24.73%. Vascular malformations in 16.13%, studies informs as normal 13.98% and ulcerative colitis in 10.75% No complications were observed so we can suggest colonoscopy as the first tool in diagnosis and treatment of the colonic pathology in children of any age.