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Mutagenic purine–pyrimidine repeats can adopt the left-handed Z-DNA conformation. DNA breaks at potential Z-DNA sites can lead to somatic mutations in cancer or to germline mutations that are transmitted to the next generation. It is not known whether any mechanism exists in the germ line to control Z-DNA structure and DNA breaks at purine–pyrimidine repeats. Here we provide genetic, epigenomic and biochemical evidence for the existence of a biological process that erases Z-DNA specifically in germ cells of the mouse male foetus. We show that a previously uncharacterized zinc finger protein, ZBTB43, binds to and removes Z-DNA, preventing the formation of DNA double-strand breaks. By removing Z-DNA, ZBTB43 also promotes de novo DNA methylation at CG-containing purine–pyrimidine repeats in prospermatogonia. Therefore, the genomic and epigenomic integrity of the species is safeguarded by remodelling DNA structure in the mammalian germ line during a critical window of germline epigenome reprogramming.

Exploring early embryonic gene expression is challenging due to the rate of development and the limited material available. Here, we present a protocol for ordering Drosophilaembryos along a developmental pseudo-time trajectory and determining the sex of the embryos using RNA-seq data. We describe steps for sample collection, RNA isolation, RNA-seq, and RNA-seq data processing. We then detail the establishment of a continuous transcriptome dataset for assessing gene expression throughout early development and in a sex-specific manner.

This article gives an overview of several new, patented (proprietary) carburising and nitriding techniques. The SAT12 process, developed by Swagelok Company, and the Kolsterising process are carburising methods that may give rise to colossal carbon supersaturation to the surface layer of austenitic stainless steels, resulting in substantial improvement to mechanical and corrosion properties. A newly-invented, patented nitriding technique for achieving colossal nitrogen content in the surface layer of austenitic stainless steel is introduced in this article, too. One of the weaknesses of conventional carburization/nitriding techniques is the formation of carbides and nitrides. However, nearly no carbide/nitride/carbonitride precipitation takes place for the new carburising/nitriding techniques until very high C/N contents. Besides, very thick carburized/nitrided layers may be achieved with the new techniques. In addition to carburising and nitriding, a variety of novel, new, and potentially patentable surface enhancing methods (e.g., surface nanostructuring processes and laser surface treatment) are also presented in this article.

Since the introduction of endovascular embolization with Guglielmi Detachable Coils (GDC)1–3in April 1997, we have performed 56 endovascular treatments for ruptured cerebral aneurysms in the acute stage based on our definition of candidates for this modality. Overall outcomes are as follows. 1) Rebleeding within one year was limited to one case (2.5%). 2) Vasospasm occurrences: four cases (7.1%) infarction and three cases (5.4%) as transient ischemia. 3) H&K Grade IV; 60% of cases resulted in improved outcomes. 4) H&K Grade II: One case of rupture during an operation. 5) Three out of five older subjects (over 80 years old) resulted in GR or MD.In this study, we reviewed endovascular embolization in acute stage in terms of candidates and technical problems.

Polyostotic fibrous dysplasia, a major osseous change in McCune-Albright syndrome, is seen in the cranium, facial bones, bones of the extremities, and ribs, but rarely in the spine. Spinal X-rays revealed no abnormalities in an 8-year-old girl with this syndrome, but99mTc-methylene diphosphonate bone scintigraphy disclosed high-density areas in the thoracic and lumbar vertebrae. Multiple well-circumscribed areas of low signal intensity were seen on T1-weighted magnetic resonance imaging (MRI) of the spine. Although MRI spine scans in this disease have never been reported, our findings in this case proved interesting for evaluating osseous lesions. MRI made it possible to differentiate between fibrous lesions (low signal intensity on T1- and T2-weighted MRI) and cartilaginous lesions (low signal intensity on T1-weighted MRI and high signal intensity on T2-weighted MRI).

Summary Systematic morphological study of the cerebral arteries was made in six autopsy cases of ruptured aneurysms. The time course of the arterial luminal narrowing was observed by repeated angiograms, and segments of the narrowed arteries were studied histologically.

Purpose: This study was performed to evaluate the effects of a residual dissection on coagulation, fibrinolysis, and platelet function after surgical treatment of acute type A aortic dissection. Methods: Between 1987 and 1995, 48 consecutive patients underwent emergency surgery for acute type A aortic dissection. Thirty-five of 41 survivors were followed-up for periods ranging from 6 to 112 months (median, 30.3 months). These survivors were classified into three groups by computed tomographic scanning and angiography. Fifteen patients had no residual dissection (group I). Of the 20 patients who had residual dissection, nine had an enlarged aorta greater than 45 mm in maximal diameter (group II), and 11 had an aorta less than 45 mm in maximal diameter (group III). For all patients, blood samples were collected for coagulation, fibrinolysis, and platelet function studies on the same day that the computed tomographic scanning had been performed. Results: @b-thromboglobulin, thrombin-antithrombin III complex, D-dimer, and @a2 plasmin inhibitor-plasmin complex concentrations were significantly higher in group II than in the other two groups. Strong correlations between the maximal diameter of the dissected aorta and @b-thromboglobulin, thrombin-antithrombin III complex, D-dimer, and plasmin inhibitor-plasmin complex concentrations were evident. In contrast, correlations between the length of the dissected aorta and coagulation/fibrinolysis measurements were weak. Conclusions: Our findings suggest that the coagulopathy worsened in proportion to the degree of dilatation of the dissected aorta. (J Vasc Surg 1997;26:609-15.)

Digestion of vesicle-bound SecA by trypsin entrapped within the vesicles showed that refolding precursor ribose-binding protein (pRBP) of Escherichia coli retards the lipid bilayer penetration by SecA while the signal peptide enhances it. This discrepancy was found to be due to reduced SecA binding to the vesicles in the presence of the pRBP while the signal peptide induced a tight binding. Studies on the binding of 1-anilino-8-naphthalene sulfonate (ANS) to SecA indicated that SecA assumes more closed conformation upon interaction with pRBP and signal peptide induces more open structure of SecA. Kinetic studies of ANS binding to SecA upon dilution of unfolded pRBP with SecA solution showed an initial fast ANS binding, which was followed by a slow release of ANS. This suggests that first the signal peptide portion of the pRBP binds with the SecA making its structure more open and then the subsequent binding of the mature domain makes the SecA structure more compact. The pRBP enhanced the digestion of SecA added to the E. coli inverted vesicles, suggesting an inhibition of SecA penetration while the signal peptide had an opposite effect, agreeing with the results from the model systems above. When the pRBP and ATP were present together, however, the penetration of SecA increased dramatically underlining the importance of the SecY/E complex for the membrane insertion of SecA.

In this paper we describe a novel approach to the scheduling and instruction selection phases of code generation. Our approach mimics that used by human programmers and combines heuristic search with hierarchical planning and a modified means-ends analysis. Optimal code generation is known to be NP-Complete hard. Our algorithm can be executed in time polynomial to the size of the input program and exponential only to the depth of the search. Empirical results show that very good results can be accomplished with depths as small as 3. The quality of the generated code is comparable (in some cases superior) to that of codes generated by human digital signal processing experts.

La maladie hémorroïdaire est une pathologie fréquente, avec un fort impact sur la qualité de vie. La ligature des artères hémorroïdaires guidée par doppler, associée à une mucopexie, permet le traitement de la pathologie hémorroïdaire de manière moins invasive que les techniques classiques.