D/D translocations in newborn children

A family study has been made of seven unselected probands with 13/14 translocations found among 5049 consecutive liveborn children at a Danish maternity hospital. All cases were 13/14 translocations and all were familial. No individuals with unbalanced chromosome constitution were found in the seven families, and there was no information which might indicate the presence of individuals with Down's syndrome among the relatives. The segregation rate of carriers to normals did not deviate from unity. The frequency of abortions, stillbirths and infant mortality among the carriers was not significantly higher than among non-carriers. Fertility among male carriers was comparatively low compared with female carriers and male carriers with normal chromosomes, but the difference was not significant. There was no indication of any increased risk of mental or physical disorders in carriers compared with normals.     

Hepatitis D

Hepatitis D virus (HDV) is a small, RNA-containing virus that requires the concomitant presence of Hepatitis B virus (HBV) in an obligate manner for its survival and pathogenicity. HDV infection is very uncommon in Czech Republic. The results of antiviral therapy of hepatitis D patients are not satisfactory. Alpha-interferon (alpha-IFN) in high doses (9-10 MU three times a week for 12 months) is usually recommended.     

Factor D

Complement factor D (FD) is a serine protease that plays an essential role in the activation of the alternative pathway (AP) by cleaving complement factor B (FB) and generating the C3 convertases C3(H₂O)Bb and C3bBb. FD is produced mainly from adipose tissue and circulates in an activated form. On the contrary, the other serine proteases of the complement system are mainly synthesized in the liver. The activation mechanism of FD has long been unknown. Recently, a serendipitous discovery in the mechanism of FD activation has been provided by a generation of Masp1 gene knockout mice lacking both the serine protease MASP-1 and its alternative splicing variant MASP-3, designated MASP-1/3-deficient mice. Sera from the MASP-1/3-deficient mice had little-to-no lectin pathway (LP) and AP activity with circulating zymogen or proenzyme FD (pro-FD). Sera from patients with 3MC syndrome carrying mutations in the MASP1 gene also had circulating pro-FD, suggesting that MASP-1 and/or MASP-3 are involved in activation of FD. Here, we summarize the current knowledge of the mechanism of FD activation that was finally elucidated using the sera of mice monospecifically deficient for MASP-1 or MASP-3. Sera of the MASP-1-deficient mice lacked LP activity, but those of the MASP-3-deficient mice lacked AP activity with pro-FD. This review illustrates the pivotal role of MASP-3 in the physiological activation of the AP via activation of FD.     

A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data

Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.     

Postzygotic D/D translocation homozygosity associated with recurrent abortions

A Robertsonian translocation involving homologous D chromosomes was found in two cases with a history of recurrent abortions. In the first case the propositus was a 37-year-old phenotypically normal man who had a balanced t(14q14q) translocation. In the second case, a 27-year-old phenotypically normal woman was found to be a balanced t(15q15q) translocation carrier. The recurrent abortions in both cases were probably owing to this translocation.     

Cell Migration in 1D and 2D Nanofiber Microenvironments

Understanding how cells migrate in fibrous environments is important in wound healing, immune function, and cancer progression. A key question is how fiber orientation and network geometry influence cell movement. Here we describe a quantitative, modeling-based approach toward identifying the mechanisms by which cells migrate in fibrous geometries having well controlled orientation. Specifically, U251 glioblastoma cells were seeded onto non-electrospinning Spinneret based tunable engineering parameters fiber substrates that consist of networks of suspended 400 nm diameter nanofibers. Cells were classified based on the local fiber geometry and cell migration dynamics observed by light microscopy. Cells were found in three distinct geometries: adhering two a single fiber, adhering to two parallel fibers, and adhering to a network of orthogonal fibers. Cells adhering to a single fiber or two parallel fibers can only move in one dimension along the fiber axis, whereas cells on a network of orthogonal fibers can move in two dimensions. We found that cells move faster and more persistently in 1D geometries than in 2D, with cell migration being faster on parallel fibers than on single fibers. To explain these behaviors mechanistically, we simulated cell migration in the three different geometries using a motor-clutch based model for cell traction forces. Using nearly identical parameter sets for each of the three cases, we found that the simulated cells naturally replicated the reduced migration in 2D relative to 1D geometries. In addition, the modestly faster 1D migration on parallel fibers relative to single fibers was captured using a correspondingly modest increase in the number of clutches to reflect increased surface area of adhesion on parallel fibers. Overall, the integrated modeling and experimental analysis shows that cell migration in response to varying fibrous geometries can be explained by a simple mechanical readout of geometry via a motor-clutch mechanism.     

D/D Translocations in Males Examined for Military Service

Three males with Robertsonian translocations were found in a sample of 1115 males examined for military service. One was a 14/15 translocation, and two were 13/14 translocations. One was spontaneous and two familial. The segregation rate of the translocations did not deviate significantly from unity in the sibships where the mother was the carrier, whereas all five children had the translocation in the two sibships where the father was the carrier. There were no abortions and no aneuploid chromosome abnormalities in the progeny of carriers with D/D translocation. There were no indications of any association between the D/D translocations and physical or mental development.     

Klinefelter''s syndrome associated with a D/D translocation.

A case of Klinefelter's syndrome and a simultaneous familial D/D translocation is described. The clinical, endocrine, and psychiatric features were typical of those found in Klinefelter's syndrome. Other family members showed no obvious abnormality despite presence of the D/D translocation.     

Hepatitis D virus

The hepatitis D virus (HDV) relies on the helper hepatitis B virus (HBV) for the provision of its envelope, which consists of hepatitis B surface antigen (HBsAg). The RNA genome of HDV is a circular rod-like structure due to its extensive intramolecular base-pairing. HDV-RNA has ribozyme activity which includes autocatalytic cleavage and self-ligation properties, essential in virus replication via the rolling circle mechanism. Replication of the RNA is thought to be effected by cellular RNA polymerase II. Hepatitis D antigen (HDAg) is the only protein encoded by HDV-RNA and its long and short forms have a regulatory role in the replication and morphogenesis of the virus. Superinfected HBV carriers who become chronically infected with HDV are at increased risk of developing cirrhosis. Attempts to treat such carriers with interferon have not been particularly successful. In recent years the epidemiology of HDV has changed primarily due to the impact of HBV vaccination in preventing an increase in the pool of susceptible individuals. © 1998 John Wiley & Sons, Ltd.     

D2 and D4 dopamine receptor polymorphisms and personality

The relationship of various dimensions of temperament, measured by the Tridimensional Personality Questionnaire (TPQ), to polymorphisms of the D₂ dopamine receptor (DRD2) and D₄ dopamine receptor (DRD4) genes was determined in 119 healthy Caucasian boys who had not yet begun to consume alcohol and other drugs of abuse. Total Novelty Seeking score of the TPQ was significantly higher in boys having, in common, all three minor (A1,B1, and Intron 6 1) alleles of the DRD2 compared to boys without any of these alleles. Boys with the DRD4 7 repeat (7R) allele also had a significantly higher Novelty Seeking score than those without this allele. However, the greatest difference in Novelty Seeking score was found when boys having all three minor DRD2 alleles and the DRD4 7R allele were contrasted to those without any of these alleles. Neither the DRD2 nor the DRD4 polymorphisms differentiated total Harm Avoidance score. Whereas subjects having all three minor DRD2 alleles had a significantly higher Reward Dependence 2 (Persistence) score than subjects without any of these alleles, no significant difference in this personality score was found between subjects with and without the DRD4 7R allele. In conclusion, DRD2 and DRD4 polymorphisms individually associate with Novelty Seeking behavior. However, the combined DRD2 and DRD4 polymorphisms contribute more markedly to this behavior than when these two gene polymorphisms are individually considered. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 81:257–267, 1998. © 1998 Wiley-Liss, Inc.     

基于CUDA的2D、3D刚性配准方法

目的:实时医学图像配准技术是外科手术导航系统的关键技术之一。在医学图像分析中,图像配准通常是一个非常耗时的操作,不利于临床实时性需求,本文研究实现了图像配准过程的加速。方法:为了提高配准速度,本文提出了一种基于CUDA(compute unified device architecture)编程模型的硬件加速配准新技术,采用并行的方法实现像素的坐标变换,线性插值,同时计算对应像素的灰度值残差。结果:配准误差为亚像素级别,配准速度要比基于CPU的配准快几十甚至上百倍。结论:该方法在保持配准精度不变的前提下,大大提高了刚性配准的速度。     

Haemoglobin D Punjab (D Los Angeles)

A search for haemoglobin variants undertaken in Canada revealed 21 unrelated instances of Hb D Punjab amongst 207,300 specimens tested. Of these, eight came from East Indian immigrants and the rest from Canadians of United Kingdom origin. No instances of Hb D Punjab were found in 14,500 specimens from Canadian Indians that were tested. The geographical origins of 27 instances of Hb D Punjab characterized at the MRC Abnormal Haemoglobin Unit, Cambridge are presented. Of these five were natives of the British Isles. The results of surveys undertaken in the United Kingdom are summarized. The global distribution of Hb D Punjab is discussed.     

RNA 3D structure prediction: (1) assessing rna 3D structure similarity from 2D structure similarity

Computational techniques for 3D structure prediction of proteins, the holy grail of bioinformatics, have undergone major developments in recent years, geared by international cooperation and competition with CASP (Critical Assessment of Structure Prediction Techniques) like contests to improve and refine them. Although straightforward extrapolation of these methodologies for the prediction of the 3D structures of other similarly relevant bio macromolecules may not be too compelling due mostly to the intrinsic differences in constitution, nature, and function between them, the conceptual framework underlying most of those techniques applied to the development of similar computational techniques in structural biology can lead to efficient systems for prediction of the 3D structure of other bio-macromolecules. One of them is the development of rational methodologies to model RNA 3D structures from the sequence of nucleotides composing them. In this paper we establish the fundamentals of a methodology to thread a sequence of nucleotides into a set of 3D fragments extracted from a data base expressly developed for this purpose. The technique is based on a newly implemented algorithm for extraction of 3D fragments by comparison of secondary structures of RNA. The result is a highly efficient system to produce a set of fragments from which entire RNA structure for the given nucleotide sequence can be built.     

A Hybrid 2D/3D User Interface for Radiological Diagnosis

This paper presents a novel 2D/3D desktop virtual reality hybrid user interface for radiology that focuses on improving 3D manipulation required in some diagnostic tasks. An evaluation of our system revealed that our hybrid interface is more efficient for novice users and more accurate for both novice and experienced users when compared to traditional 2D only interfaces. This is a significant finding because it indicates, as the techniques mature, that hybrid interfaces can provide significant benefit to image evaluation. Our hybrid system combines a zSpace stereoscopic display with 2D displays, and mouse and keyboard input. It allows the use of 2D and 3D components interchangeably, or simultaneously. The system was evaluated against a 2D only interface with a user study that involved performing a scoliosis diagnosis task. There were two user groups: medical students and radiology residents. We found improvements in completion time for medical students, and in accuracy for both groups. In particular, the accuracy of medical students improved to match that of the residents.     

De novo Robertsonian D/D type translocations: the Leuven experience

In this paper we report a de novo 13/14 Robertsonian type translocation with apparent loss of band 14q11 in a mentally retarded, blind 24-year-old male. The findings in 10 other patients with a de novo Robertsonian D/D type translocation diagnosed in this center are reviewed.     

Registering 2D and 3D imaging data of bone during healing

Abstract

Purpose/Aims of the study: Bone’s hierarchical structure can be visualized using a variety of methods. Many techniques, such as light and electron microscopy generate two-dimensional (2D) images, while micro-computed tomography (µCT) allows a direct representation of the three-dimensional (3D) structure. In addition, different methods provide complementary structural information, such as the arrangement of organic or inorganic compounds. The overall aim of the present study is to answer bone research questions by linking information of different 2D and 3D imaging techniques. A great challenge in combining different methods arises from the fact that they usually reflect different characteristics of the real structure.

Materials and methods: We investigated bone during healing by means of µCT and a couple of 2D methods. Backscattered electron images were used to qualitatively evaluate the tissue’s calcium content and served as a position map for other experimental data. Nanoindentation and X-ray scattering experiments were performed to visualize mechanical and structural properties.

Results: We present an approach for the registration of 2D data in a 3D µCT reference frame, where scanning electron microscopies serve as a methodic link. Backscattered electron images are perfectly suited for registration into µCT reference frames, since both show structures based on the same physical principles. We introduce specific registration tools that have been developed to perform the registration process in a semi-automatic way.

Conclusions: By applying this routine, we were able to exactly locate structural information (e.g. mineral particle properties) in the 3D bone volume. In bone healing studies this will help to better understand basic formation, remodeling and mineralization processes.