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The tropical carpenter bee, Xylocopa latipes, has metallic-reflecting, iridescent wings. The wing reflectance spectra for TE- and TM-polarized light depend on the angle of light incidence in a way characteristic for dielectric multilayers. Anatomy indicates the presence of melanin multilayers in the wing’s chitinous matrix. A simple optical model of melanin multilayers explains the angle dependence of the wing reflectance spectra. The wing reflections that occur upon oblique illumination exhibit colourful and strongly polarized light patterns, which may mediate intraspecific signaling and mutual recognition by conspecifics.

The tropical carpenter bee, Xylocopa latipes, has metallic-reflecting, iridescent wings. The wing reflectance spectra for TE- and TM-polarized light depend on the angle of light incidence in a way characteristic for dielectric multilayers. Anatomy indicates the presence of melanin multilayers in the wing's chitinous matrix. A simple optical model of melanin multilayers explains the angle dependence of the wing reflectance spectra. The wing reflections that occur upon oblique illumination exhibit colourful and strongly polarized light patterns, which may mediate intraspecific signaling and mutual recognition by conspecifics.

While the importance of automatic image analysis is increasing at an enormous pace, recent meta-research revealed major flaws with respect to algorithm validation. Specifically, performance metrics are key for objective, transparent and comparative performance assessment, but relatively little attention has been given to the practical pitfalls when using specific metrics for a given image analysis task. A common mission of several international initiatives is therefore to provide researchers with guidelines and tools to choose the performance metrics in a problem-aware manner. This dynamically updated document has the purpose to illustrate important limitations of performance metrics commonly applied in the field of image analysis. The current version is based on a Delphi process on metrics conducted by an international consortium of image analysis experts.

Magnetic Resonance Imaging (MRI) is widely used in routine clinical diagnosis and treatment. However, variations in MRI acquisition protocols result in different appearances of normal and diseased tissue in the images. Convolutional neural networks (CNNs), which have shown to be successful in many medical image analysis tasks, are typically sensitive to the variations in imaging protocols. Therefore, in many cases, networks trained on data acquired with one MRI protocol, do not perform satisfactorily on data acquired with different protocols. This limits the use of models trained with large annotated legacy datasets on a new dataset with a different domain which is often a recurring situation in clinical settings. In this study, we aim to answer the following central questions regarding domain adaptation in medical image analysis: Given a fitted legacy model, 1) How much data from the new domain is required for a decent adaptation of the original network?; and, 2) What portion of the pre-trained model parameters should be retrained given a certain number of the new domain training samples? To address these questions, we conducted extensive experiments in white matter hyperintensity segmentation task. We trained a CNN on legacy MR images of brain and evaluated the performance of the domain-adapted network on the same task with images from a different domain. We then compared the performance of the model to the surrogate scenarios where either the same trained network is used or a new network is trained from scratch on the new dataset.The domain-adapted network tuned only by two training examples achieved a Dice score of 0.63 substantially outperforming a similar network trained on the same set of examples from scratch., 8 pages, 3 figures

The pierid butterfly Colias croceus (Geoffroy in Fourcroy, 1785), established in the Azores archipelago, is polymorphic with six forms, C. croceus f. croceus ♂ and ♀, C. c. f. cremonae ♂ and ♀, C. c. f. helice ♀, and C. c. f. cremonaehelice ♀. We investigated the optical mechanisms underlying the wing colouration of the butterflies by performing spectrophotometry and imaging scatterometry of the variously coloured wing areas and scales. The scale colouration is primarily due to wavelength-selective absorption of incident light by pterins expressed in granular beads in the wing scales, but thin film reflections of the scales’ lower lamina and scale stacking also contribute. Three forms (croceus ♂ and ♀ and helice ♀) are consistent with the patterns of the well-known ‘alba’ polymorphism. We postulate the coexistence of a second polymorphism, ‘cremonae’, to understand the three other forms (cremonae ♂ and ♀, and cremonaehelice ♀), which are characterized by the absence of red pigment, presumably due to the differential blocking of erythropterin expression.

The palm borer moth Paysandisia archon (Castniidae; giant butterfly-moths) has brown dorsal forewings and strikingly orange-coloured dorsal hindwings with white spots surrounded by black margins. Here, we have studied the structure and pigments of the wing scales in the various coloured wing areas, applying light and electron microscopy and (micro)spectrophotometry, and we analysed the spatial reflection properties with imaging scatterometry. The scales in the white spots are unpigmented, those in the black and brown wing areas contain various amounts of melanin, and the orange wing scales contain a blue-absorbing ommochrome pigment. In all scale types, the upper lamina acts as a diffuser and the lower lamina as a thin film interference reflector, with thickness of about 200 nm. Scale stacking plays an important role in creating the strong visual signals: the colour of the white eyespots is created by stacks of unpigmented blue scales, while the orange wing colour is strongly intensified by stacking the orange scales.

The blue secondary and purple-to-green tail feathers of magpies are structurally coloured due to stacks of hollow, air-containing melanosomes embedded in the keratin matrix of the barbules. We investigated the feathers’ spectral and spatial reflection characteristics by applying (micro)spectrophotometry and imaging scatterometry. To interpret the spectral data, we performed optical modelling, applying the Finite-Difference Time-Domain (FDTD) method as well as an effective media approach, treating the melanosome stacks as multilayers with effective refractive indices dependent on the component media. The differently coloured magpie feathers are realised by adjusting the melanosome size, with the diameter of the melanosomes as well as their hollowness being the most sensitive parameters that influence the appearance of the feathers.

The ventral hindwings of Pipevine Swallowtail butterflies, Battus philenor, display a colourful pattern, created by variously coloured wing scales. Reflectance and transmittance measurements of single scales indicate that the cream and orange scales contain papiliochrome pigments, while brown, black and blue scales contain melanin. Microspectrophotometry and scatterometry of both sides of the wing scales show that the lower lamina acts as a thin film, with reflection properties dependent on the scale's pigmentation. Notably in the orange scales, the reflectance spectrum of the lower lamina is tuned to the pigment's absorbance spectrum. The dorsal hindwings of the male (but not the female) B. philenor are blue-green iridescent. At oblique illumination, the light reflected by the male's dorsal hindwings can be highly polarised, which may have a function in intersexual signalling.

Background/Purpose: Gastroesophageal reflux is a major cause of complications after esophageal atresia repair. The suitability of the Nissen fundoplication in these patients is still disputed. Therefore, the authors evaluated the results of their prospective treatment protocol in those patients who underwent a Nissen fundoplication. Methods: From 1984 to 1996, 125 patients underwent anastomosis for esophageal atresia. A Nissen fundoplication was later performed in 29 patients. The prospective protocol included x-ray after 10 days, 6 weeks, 12 weeks, 6 months, and 12 months. Forty-eightNhour pH measurements were performed between 6 and 12 weeks. Mean postfundoplication follow-up was at least 5 years (range, 2 to 13 years). Results: Two of the 29 patients died after the Nissen fundoplication from unrelated causes. A third patient was excluded from the study group. Nineteen of the remaining 26 patients showed severe stricture. pH-metry succeeded in 18 patients, showing pathological reflux in 17. In 24 patients the fundoplication was performed between 1 and 24 months (median, 4 months), in the other 2 patients much later. In 4 of the 26 patients (15%) the Nissen proved to be insufficient and had to be redone. The remaining 22 patients had no short-term or long-term complications. Conclusion: The authors' findings in this group of patients, comparing them with the results reported in the literature, indicate that there is no reason to change their prospective treatment protocol nor their policy to perform Nissen fundoplications at an early stage. J Pediatr Surg 35:573-576. Copyright © 2000 by W.B. Saunders Company.

SUMMARY The wings of the swordtail butterfly Graphium sarpedon (the Common Bluebottle) have blue/green-colored patches that are covered on the underside by two types of scales: white and glass scales. Transmission and scanning electron microscopy revealed that the white scales are classically structured: the upper lamina, with prominent ridges and large open windows, is well separated by trabeculae from a flat, continuous lower lamina. In the glass scales, the upper lamina, with inconspicuous ridges and windows, is almost flat and closely apposed to the equally flat lower lamina. The glass scales thus approximate ideal thin films, in agreement with the observation that they reflect light directionally and are iridescent. Reflectance and transmittance spectra measured from the glass scales with a microspectrophotometer agree with spectra calculated for an ideal non-absorbing thin film. Imaging scatterometry of single, isolated glass scales demonstrated that the reflected light can be strongly polarized, indicating that they function as polarizing reflectors.

SUMMARYThe colours of the common kingfisher, Alcedo atthis, reside in the barbs of the three main types of feather: the orange breast feathers, the cyan back feathers and the blue tail feathers. Scanning electron microscopy showed that the orange barbs contain small pigment granules. The cyan and blue barbs contain spongy nanostructures with slightly different dimensions, causing different reflectance spectra. Imaging scatterometry showed that the pigmented barbs create a diffuse orange scattering and the spongy barb structures create iridescence. The extent of the angle-dependent light scattering increases with decreasing wavelength. All barbs have a cortical envelope with a thickness of a few micrometres. The reflectance spectra of the cortex of the barbs show oscillations when measured from small areas, but when measured from larger areas the spectra become wavelength independent. This can be directly understood with thin film modelling, assuming a somewhat variable cortex thickness. The cortex reflectance appears to be small but not negligible with respect to the pigmentary and structural barb reflectance.

Eight sediment cores were taken from Lake Ketelmeer, a sedimentation area of the Rhine River, located in the central part of The Netherlands. Priority pollutants (eight metals, six planar and mono-ortho polychlorinated biphenyls, seven polychlorinated dibenzo-p-dioxins, 10 polychlo-rinated dibenzofurans, and eight polycyclic aromatic hydrocarbons) were determined in all or in a selected number of cores. Present-day and historical levels of pollutants since the late 1930s were established through the use of radionuclide time tracers (137Cs, 134Cs) and area-specific geological time markers. Postdepositional redistribution of pollutants and possible transformations were evaluated by analyzing sediment top-layer samples that were taken in 1972. Disappearance in the anaerobic sediment was observed for several chlorinated biphenyls, dioxins, and furans, Disappearance of the chlorinated compounds may be caused by microbial dechlorination reactions in the anaerobic lake sediment. For the persistent metals and polycyclic aromatic hydrocarbons, as well as for the somewhat changed concentrations of chlorinated aromatics, trends in the concentration profiles during the last five decades are described. Rather low concentrations of almost all studied chlorinated compounds were observed in the early 1940s. These low levels were in contrast to the metal and PAH concentrations, which were already high in the late 1930s and were lowered during the second world war. For all studied compounds, maximum concentrations were found between 1955 and 1975. Cadmium and nickel levels remained high until 1980. The highly toxic 2,3,7,8-tetrachlo-rodibenzo-p-dioxin reached concentrations up to 400 ng/kg in the mid-1960s. Recently deposited sediments showed lower pollutant levels. The levels of lead, arsenic, and all studied PAHs were the lowest observed in the past five decades.

Cystic fibrosis (CF) lung disease is characterized by chronic airway inflammation and recurrent infections, resulting in (ir)reversible structural lung changes and a progressive decline in lung function. The objective of this study was to investigate the relationship between non-invasive inflammatory markers (IM) in exhaled breath condensate (EBC), lung function indices and structural lung changes, visualized by high resolution computed tomography (HRCT) scans in CF. In 34 CF patients, lung function indices (forced expiratory volume in 1 s, forced vital capacity [FVC], residual volume, and total lung capacity [TLC]) and non-invasive IM (exhaled nitric oxide, and condensate acidity, nitrate, nitrite, 8-isoprostane, hydrogen peroxide, interferon-gamma) were assessed. HRCT scans were scored in a standardized and validated way, a composite score and component scores were calculated. In general, the correlations between non-invasive IM and structural lung changes, and between IM and lung function were low (correlation coefficients0.40). Patients with positive sputum Pseudomonas cultures had higher EBC nitrite levels and higher parenchymal HRCT subscores than patients with Pseudomonas-negative cultures (p0.05). Multiple linear regression models demonstrated that FVC was significantly predicted by hydrogen peroxide in EBC, and the scores of bronchiectasis and mosaic perfusion (Pearson correlation coefficient R = 0.78, p0.001). TLC was significantly predicted by 8-isoprostane, nitrate, hydrogen peroxide in EBC, and the mucous plugging subscore (R = 0.92, p0.01). Static and dynamic lung function indices in this CF group were predicted by the combination of non-invasive IM in EBC and structural lung changes on HRCT imaging. Future longitudinal studies should reveal whether non-invasive monitoring of airway inflammation in CF adds to better follow-up of patients.

Since cerebrospinal fluid shunt malfunction is common and its diagnosis often requires invasive testing, we have evaluated magnetic resonance imaging (MRI) as a noninvasive test for shunt function. In prior experiments, MRI has been shown to be capable of detecting flows as low as 0.4 cc h-1 in shunt systems. Because patient movement and position in an MRI scanner are variable, we have studied the effects of shunt position on the ability to reliably detect the rate of CSF flow. Flow related enhancement of fluid flowing from 0 to 2 cc h-1 was measured in a specialized section of tubing using multiple spin echo scans (TR2000,TE20). The angle of the specialized tubing was varied relative to the axis of the MRI scanner and then the intensity of the MR signal at specific points in the tubing was measured at different flow rates. No flow standards were used as controls. The results show that the linear relationship between signal intensity and flow that had previously been demonstrated was significantly altered by changes of position. Positions angled superior to the axis of the scanner enhanced the signal while lateral changes in the plane of the scan degraded the signal. These results suggest that in order for MRI to become an accurate test for shunt function, techniques must be developed to overcome the effects of shunt position.

Background: Gastroesophageal reflux is a major cause of anastomotic complications after repair of esophageal atresia. For this reason, we evaluated a prospective, postoperative treatment protocol with the emphasis on comparing medical and operative treatment. Study Design: From 1994 to 1995, 26 consecutive patients underwent correction of esophageal atresia in the Sophia Children's Hospital. These patients were enrolled in a decision-making protocol meant to establish the effect of medical treatment on gastroesophageal reflux and stricture formation, the relation between anastomotic tension and reflux, and the question of whether performing a Nissen fundoplication was justified. Patients who showed reflux on the first postoperative x-ray were given medical treatment. Reflux was assessed after 6–12 weeks by x-ray and 48-hour pH-metry (24 hours with and 24 hours without medication). Evaluations were repeated at 18 weeks, 6 months, and 1 year. Twenty-three patients were followed for ≥ 1 year. Results: Twenty-four patients had classic esophageal atresia combined with tracheoesophageal fistula. Two had isolated atresia and underwent a colonic interposition. One of the others died of severe cerebral hemorrhage early after the operation. Twenty-two of the remaining 23 showed reflux on the first postoperative x-ray and were given medical treatment. The mean 3.8% total mild reflux time (range, 0.0–11.0%) decreased to a mean of 1.47% (range, 0.0–6.8%). Medical treatment given according to protocol did not influence severe reflux. Eleven of 23 patients showed stricture formation, requiring a mean of four dilatation procedures (range, 1–9). Defining a real stricture as one needing three or more dilatations, as seen in seven patients, the following results were seen: four nonrefluxing patients (proved by x-ray and pH-metry) needed a mean of 4.2 dilatations (range, 3–7), and three refluxing patients (proved by x-ray and pH-metry) needed a mean of 7.3 dilatations (range, 5–9). Three of seven patients with anastomotic tension had proved gastroesophageal reflux; reflux was also diagnosed in 8 of 15 patients without any tension on the anastomosis. Nine of 23 patients underwent a Nissen fundoplication according to the protocol. In four of them, this was decided because of severe reflux-associated respiratory problems; in one, for resistent stenosis after a Livaditis procedure; and in one with normal pH-metry, the procedure was done on clinical grounds. The latter patient needed an aortopexy at a later stage. A late fundoplication was performed in two patients for persistent gastroesophageal reflux unresponsive to medical treatment, and in one for persistent stenosis and reflux. In all patients, the outcomes were successful, without complications. Conclusions: Medical treatment of gastroesophageal reflux after repair of esophageal atresia has a distinct effect on the duration of reflux and could have a positive effect on the occurrence and treatment of stenosis. There is no clear relation between the occurrence of reflux and tension on the anastomosis. Nissen fundoplication according to the protocol was done appropriately in eight of nine patients.

Background: This study was undertaken to determine baseline values of 24-hour pH-metry in children who had undergone correction for esophageal atresia. Methods: A 24-hour pH-metry without medication was conducted in 13 patients with an uncomplicated postoperative course after correction of esophageal atresia. The pH-metry was performed in the hospital with a flexible glass electrode. Results: The mean reflux index was 4.08%, the mean total number of reflux periods with a pH less than 4 was 21, and the mean number of periods of pH less than 4 lasting longer than 5 minutes was 2.5. Conclusions: Twenty-four-hour pH-metry values in asymptomatic esophageal atresia patients are the same as in children from the same age group with normal anatomy.

In case of congenital diaphragmatic hernia (CDH), survival generally depends not on prenatal diagnosis, planned delivery, and immediate postnatal operation, but on the gravity of pulmonary hypoplasia and persistent hypertension (PPH). Many vasoactive drugs have become available for lowering PPH, but the mortality rate for CDH still amounts to 40% to 70%. Preoperative stabilization might prevent or at least reduce the risk of PPH. This method was evaluated in a pilot study lasting 15 months and involving 13 patients. All were admitted to the pediatric surgical intestive care unit within six hours of birth, all requiring mechanical ventilation. Continuous suction of the stomach and bowel proved successful in reducing the mediastinal shift. Study parameters were alveolar-arterial oxygenation differences ((A-a)DO 2 ), mean airway pressure (MAP), oxygenation index (OI), and ventilation index (VI), measured on admission and at set times before and after surgery. Eight patients did not survive, but in two cases death was not directly related to CDH. The following conclusions were reached: (1) satisfactory ventilation parameters on admission will remain good during the preoperative stabilization phase and will not be affected by its duration or by subsequent surgery, spelling survival; (2) unsatisfactory ventilation parameters on admission may improve with preoperative stabilization, giving these patients a better chance of survival; and (3) poor ventilation parameters on admission that fail to improve with preoperative stabilization will not improve with surgery or postoperatively, spelling death.

To obtain additional insight into the chemical reactions occuring furing fixation of tissue lipids by osmium tetroxide, the reaction between osmium tetroxide and lecithin has been studied. Procedures have been developed whereby quantitative information may be obtained about the nature of this reaction. One series of experiments was designed to arrive at the stoichiometry of the reaction and its time-course. To this end air-dried lecithin spots on cover glasses or on filter paper were exposed to oxmium tetroxide vapor. The weight increase of the lecithin spots was determined, and related to time of exposure to osmium tetroxide and to the quantity of lecithin present. Under the conditions chosen the binding of osmium tetroxide rapidly reaches a limiting value; thus the reaction appears to proceed to a definite end-point. The number of double bonds in the lecithin molecule, as determined by gas chromatography, corresponds with the number of moles of osmium tetroxide bound per mole of lecithin. This supplements earlier spectrophotometric findings, and confirms part of the reaction scheme proposed by Criegee for the interaction between osmium tetroxide and unsaturated compounds generally. The chemical properties of lecithin, and of other polar lipids, are determined not only by the presence of unsaturated linkages but also by the presence of an ampho-ionic group. Earlier research has demonstrated that this group is responsible for the staining properties of lecithin with anionic dyes, for instance, Brilliant Scarlet 3 R (Ponceau 4R or 4RS, Colour Index No. 16255). In this paper evidence is presented to show that the stainability of lecithin spots by Brilliant Searlet 3 R, under specified conditions, decreases markedly with increasing time of exposure to osmium tetroxide. It appears likely that as a result of the reaction with osmium tetroxide the lecithin polar group has changed properties. After studying the staining properties of lecithin towards an anionic dye, in relation to time of exposure to osmium tetroxide, its staining capacity for a representative cationic dye was similarly studied. Evidence is presented demonstrating an increased binding capacity of exposed lecithin spots to Brilliant Green (Colour Index no 42040). After considering a few possible interpretations we suggest that the simplest hypothesis to account for this phenomenon is a partial removal of the positive charge of lecithin, whereby the negatively charged groups are freed for interaction with positive dye molecules.

Six patients with total colonic aganglionosis (TCA) with ileal involvement were treated with a total colectomy and ileorectal anastomosis according to Rehbein. Follow-up lasted from 1 to 7 years and showed no mortality. Postoperative management consisted of total parenteral nutrition initially, followed by gradual introduction of oral feeding beginning with a low-osmolarity low-residue diet, the use of loperamide, an adequate oral intake of salt, and regular bowel deflation. Major postoperative complications disappeared and all patients demonstrated weight gain by the end of the first postoperative year, with normal feeding and two to three soft stools per day.

The effects on yeast cells of two related compounds, chlorhexidine and paludrine. were compared with those of cetyltrimethylammonium bromide (CTAB). The action of chlorhexidine closely resembles that of CTAB, following an all-or-none pattern. Involvement of membrane lipids is suggested by the similar effect of chlorhexidine and CTAB on liposomes. The possibility, that the disruptive effect of positive surfactants is due to their penetration of the region of the glycerol moieties of membrane lipids is discussed.

The extraction of lipids from lipoproteins with ether proceeds according to unusual kinetics. The addition of small amounts of ethanol is necessary. It was shown that the same kind of phenomenon may occur when oil is extracted by petroleum ether from emulsions prepared with combinations of charged surfactants. In mixtures of positive and negative surfactants the kinetics of oil extraction proved to be highly complicated. In many cases the extraction of oil is inversely related to the development of a thick interfacial layer. This layer consists of swollen emulsion droplets surrounded by thin layers of a P-coacervate. The kinetics of oil extraction is determined by three factors: (1) the leakage of oil through the P-coacervate; (2) the penetration of petroleum ether into the emulsion droplets; and (3) the maximal amount of stretching of the P-coacervate layer. If the first factor is relatively low and the third relatively high, the oil extraction will at first be low and increase suddenly after a certain time of shaking with petroleum ether. It is suggested that the same type of mechanism results in the S-curve relating lipid extraction and time in lipoprotein extraction.

Supplemental Digital Content is available in the text., Background: Complex molecular programs in specific cell lineages govern human heart development. Hypoplastic left heart syndrome (HLHS) is the most common and severe manifestation within the spectrum of left ventricular outflow tract obstruction defects occurring in association with ventricular hypoplasia. The pathogenesis of HLHS is unknown, but hemodynamic disturbances are assumed to play a prominent role. Methods: To identify perturbations in gene programs controlling ventricular muscle lineage development in HLHS, we performed whole-exome sequencing of 87 HLHS parent–offspring trios, nuclear transcriptomics of cardiomyocytes from ventricles of 4 patients with HLHS and 15 controls at different stages of heart development, single cell RNA sequencing, and 3D modeling in induced pluripotent stem cells from 3 patients with HLHS and 3 controls. Results: Gene set enrichment and protein network analyses of damaging de novo mutations and dysregulated genes from ventricles of patients with HLHS suggested alterations in specific gene programs and cellular processes critical during fetal ventricular cardiogenesis, including cell cycle and cardiomyocyte maturation. Single-cell and 3D modeling with induced pluripotent stem cells demonstrated intrinsic defects in the cell cycle/unfolded protein response/autophagy hub resulting in disrupted differentiation of early cardiac progenitor lineages leading to defective cardiomyocyte subtype differentiation/maturation in HLHS. Premature cell cycle exit of ventricular cardiomyocytes from patients with HLHS prevented normal tissue responses to developmental signals for growth, leading to multinucleation/polyploidy, accumulation of DNA damage, and exacerbated apoptosis, all potential drivers of left ventricular hypoplasia in absence of hemodynamic cues. Conclusions: Our results highlight that despite genetic heterogeneity in HLHS, many mutations converge on sequential cellular processes primarily driving cardiac myogenesis, suggesting novel therapeutic approaches.

© Springer Nature Switzerland AG 2018. Delineation of organs at risk (OAR) on CT images is a crucial step in the planning of radiotherapy treatment. Manual delineation is time-consuming and high interrater variability is observed within and across radiotherapy centers. Automated delineation of OAR is fast and can lead to more consistent treatment plans. We developed an auto-delineation tool based on a 3D convolutional neural network (CNN) to automatically delineate 16 OAR structures in head and neck cancer (HNC) patients. The CNN was trained off-line using 70 previously collected patient datasets and implemented to be available on-line in clinical routine practice. The tool was applied prospectively for delineation of 20 consecutive new HNC cases within the department of Radiation Oncology, with subsequent manual editing and approval of the contours by the clinical expert. Validation based on the automatically proposed and edited contours shows that the auto-delineation tool is able to achieve highly accurate segmentation results for most OAR. As a result, 3D delineation time is reduced to less than 19 min on average (about 1 min/structure), compared to usually 1 h or more without auto-delineation tool. ispartof: pages:223-232 ispartof: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) vol:11041 LNCS pages:223-232 ispartof: 7th international workshop on clinical image-based procedures: Translational research in medical imaging - CLIP 2018, held in conjunction with MICCAI 2018 location:Granada, Spain date:16 Sep - 16 Sep 2018 status: published

This paper presents a novel method for multi-modal lung image registration constrained by a motion model derived from lung 4DCT. The motion model is estimated based on the results of intra-patient image registration using Principal Component Analysis. The approach with a prior motion model is particularly important for regions where there is not enough information to reliably drive the registration process, as in the case of hyperpolarized Xenon MRI and proton density MRI to CT registration. Simultaneously, the method addresses local variations between images in the supervoxel-based motion model parameters optimization step. We compare our results in terms of the plausibility of the estimated deformations and correlation coefficient with 4DCT-based estimated ventilation maps using state-of-the-art multi-modal image registration methods. Our method achieves higher average correlation scores, showing that the application of Principal Component Analysis-based motion model in the deformable registration, helps to drive the registration for the regions of the lungs with insufficient amount of information.

Mucopolysaccharidosis type VI (MPS VI; Maroteaux-Lamy syndrome) is a lysosomal storage disorder caused by mutations in the N-acetylgalactosamine-4-sulfatase (arylsulfatase B, ARSB) gene. ARSB is a lysosomal enzyme involved in the degradation of the glycosaminoglycans (GAG) dermatan and chondroitin sulfate. ARSB mutations reduce enzyme function and GAG degradation, causing lysosomal storage and urinary excretion of these partially degraded substrates. Disease onset and rate of progression is variable, producing a spectrum of clinical presentation. In this study, 105 MPS VI patients—representing about 10% of the world MPS VI population—were studied for molecular genetic and biochemical parameters. Direct sequencing of patient genomic DNA was used to identify ARSB mutations. In total, 83 different disease-causing mutations were found, 62 of which were previously unknown. The novel sequence changes included: 38 missense mutations, five nonsense mutations, 11 deletions, one insertion, seven splice-site mutations, and four polymorphisms. ARSB mutant protein and residual activity were determined on fibroblast extracts for each patient. The identification of many novel mutations unique to individuals/their families highlighted the genetic heterogeneity of the disorder and provided an appropriate cohort to study the MPS VI phenotypic spectrum. This mutation analysis has identified a clear correlation between genotype and urinary GAG that can be used to predict clinical outcome. Hum Mutat 28(9), 897–903, 2007. Published 2007 Wiley-Liss, Inc.