STUDY QUESTION
Does the health status of infants fathered by nonmosaic Klinefelter syndrome (KS) patients whose partners underwent ICSI with sperm obtained from testicular dissection reveal any ...genetic risk for the offspring?.
SUMMARY ANSWER
KS patients undergoing testicular sperm extraction (TESE) are capable of conceiving healthy children.
WHAT IS KNOWN ALREADY
Paternity has been successfully achieved in nonmosaic KS patients (47,XXY karyotype) by ICSI using either ejaculated or testicular spermatozoa. A crucial concern is the potential transmission of genetic abnormalities to the offspring. Some studies reported that 47,XXY spermatogonia are capable of completing spermatogenesis leading to the production of mature spermatozoa with increased aneuploidies. Other authors showed that where focal spermatogenesis is present in nonmosaic KS males, it originates from euploid germ cells and, therefore, produces normal mature gametes. In support of this finding, at present, the great majority of children born from nonmosaic KS patients are chromosomally normal.
STUDY DESIGN, SIZE, DURATION
From April 2004 to June 2010, 38 azoospermic patients with nonmosaic KS were examined for the presence of testicular spermatozoa. Spermatozoa were retrieved from 15 patients and 26 ICSI cycles were done (16 with cryopreserved sperm). There were 15 pregnancies leading to the birth of 16 babies who were karyotyped at amniocentesis and after birth.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Participants were recruited from couples attending the European Hospital, Rome, and Clinica MAR&Gen, Granada, for infertility treatment. Both the European Hospital and Clinica MAR&Gen are private clinics. Testicular tissue was extracted with TESE or micro-TESE. After retrieval, fresh sperm was used for ICSI or it was cryopreserved for future use.
MAIN RESULTS AND THE ROLE OF CHANCE
Spermatozoa were retrieved from 15 patients (14 TESE and 1 micro-TESE) out of 38 (39.5%). A total of 26 ICSI cycles were performed: 10 with fresh and 16 with cryopreserved-thawed sperm. Mean ages (y) of patients with positive and negative sperm retrieval were, respectively, 34.8 ± 1.72 and 35.6 ± 4.08 (NS, nonsignificant). Comparing ICSI cycles performed with fresh sperm (n = 10) to those performed with frozen–thawed sperm (n = 16): Fertilization rates per injected oocyte were 53.0% (44 of 83) and 47.8% (32 of 67), respectively (NS). The cleavage rate per injected oocyte was 90.6% (29 of 32) versus 68.2% (30 of 44); P = 0.026. Clinical outcomes were not significantly different between the fresh and the frozen–thawed sperm group: clinical pregnancy rates were 7 of 10 (70.0%) and 8 of 16 (50.0%); implanted embryos (per transferred embryo) were 8 of 23 (34.8%) and 8 of 29 (27.6%); delivery rates were 6 of 10 (60.0%) and 5 of 16 (31.3%). Sixteen babies were born, all of them are healthy with a normal karyotype, eight from the fresh sperm group and eight from the frozen–thawed sperm group.
LIMITATIONS, REASONS FOR CAUTIONS
The small numbers available for study mean that only common problems can be excluded.
WIDER IMPLICATIONS OF THE FINDINGS
This study provides further reassurance that KS men can father healthy children and that pre-implantation genetic diagnosis on embryos conceived with their sperm is not strongly indicated. However, until conclusive information is available, such couples should be offered extensive genetic counseling.
STUDY FUNDING/COMPETING INTEREST(S)
No external funding was obtained for the present study. None of the authors has any conflict of interest to declare.
TRIAL REGISTRATION NUMBER
Not applicable.
In this paper, we introduce a new recursive neural network model able to process directed acyclic graphs with labelled edges. The model uses a state transition function which considers the edge ...labels and is independent both from the number and the order of the children of each node. The computational capabilities of the new recursive architecture are assessed. Moreover, in order to test the proposed architecture on a practical challenging application, the problem of object detection in images is also addressed. In fact, the localization of target objects is a preliminary step in any recognition system. The proposed technique is general and can be applied in different detection systems, since it does not exploit any a priori knowledge on the particular problem. Some experiments on face detection, carried out on scenes acquired by an indoor camera, are reported, showing very promising results.
The Graph Neural Network Model Scarselli, F.; Gori, M.; Ah Chung Tsoi ...
IEEE transactions on neural networks,
2009-Jan., 2009, 2009-Jan, 2009-01-00, 20090101, Letnik:
20, Številka:
1
Journal Article
Odprti dostop
Many underlying relationships among data in several areas of science and engineering, e.g., computer vision, molecular chemistry, molecular biology, pattern recognition, and data mining, can be ...represented in terms of graphs. In this paper, we propose a new neural network model, called graph neural network (GNN) model, that extends existing neural network methods for processing the data represented in graph domains. This GNN model, which can directly process most of the practically useful types of graphs, e.g., acyclic, cyclic, directed, and undirected, implements a function tau(G,n) isin IR m that maps a graph G and one of its nodes n into an m -dimensional Euclidean space. A supervised learning algorithm is derived to estimate the parameters of the proposed GNN model. The computational cost of the proposed algorithm is also considered. Some experimental results are shown to validate the proposed learning algorithm, and to demonstrate its generalization capabilities.
Discusses the ability of multilayer perceptrons (MLPs) to model the probability distribution of data in typical pattern recognition and verification problems. It is proven that multilayer perceptrons ...with sigmoidal units and a number of hidden units less or equal than the number of inputs are unable to model patterns distributed in typical clusters, since these networks draw open separation surfaces in the pattern space. When using more hidden units than inputs, the separation surfaces can be closed but, unfortunately it is proven that determining whether or not a MLP draws closed separation surfaces in the pattern space is NP-hard. The major conclusion of the paper is somewhat opposite to what is believed and reported in many application papers: MLPs are definitely not adequate for applications of pattern recognition requiring a reliable rejection and, especially, they are not adequate for pattern verification tasks.
Localizing faces in images is a difficult task, and represents the first step towards the solution of the face recognition problem. Moreover, devising an effective face detection method can provide ...some suggestions to solve similar object and pattern detection problems. This paper presents a novel approach to the solution of the face localization problem using Recursive neural networks (RNNs). The proposed method assumes a graph-based representation of images that combines structural and symbolic visual features. Such graphs are then processed by RNNs, in order to establish the possible presence and the position of faces inside the image. A novel RNN model that can deal with graphs with labeled edges has been also exploited. Some experiments on snapshots from video sequences are reported, showing very promising results.
Self-Organizing Maps capable of encoding structured information will be used for the clustering of XML documents. Documents formatted in XML are appropriately represented as graph data structures. It ...will be shown that the Self-Organizing Maps can be trained in an unsupervised fashion to group XML structured data into clusters, and that this task is scaled in linear time with increasing size of the corpus. It will also be shown that some simple prior knowledge of the data structures is beneficial to the efficient grouping of the XML documents.
An 8 bit segmented current steering DAC is presented for the compensation of mismatch of sensors with current output arranged in a large arrays. The DAC is implemented in a 1.8 V supply voltage 180 ...nm standard CMOS technology. Post layout simulations reveal that the design target concerning a sampling frequency of 2.6 MHz is exceeded, worst-case settling time equals 60.6 ns. The output current range is 0–10 μA, which translates into an LSB of 40 nA. Good linearity is achieved, INL < 0.5 LSB and DNL < 0.4 LSB, respectively. Static power consumption with the outputs operated at a voltage of 0.9 V is approximately 10 μW. Dynamic power, mainly consumed by switching activity of the digital circuit parts, amounts to 100 μW at 2.6 MHz operation frequency. Total area is 38.6 × 2933.0 μm2.
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