objective(s) varicocele is associated with impaired testicular function and male infertility, but the molecular mechanisms by which fertility is affected have not been satisfactorily explained. the aim of our study was to investigate whether or not the polymerase gamma (polg) polymorphism is associated with iranian varicocele patients.    materials and methods we determined the polg cag repeat ...

In this article, the effect of a d(CG) DNA dinucleotide repeat sequence on RNA polymerase II transcription is examined in yeast Saccharomyces cerevisiae. Our previous report shows that a d(CG)n dinucleotide repeat sequence located proximally upstream of the TATA box enhances transcription from a minimal CYC1 promoter in a manner that depends on its surrounding negative supercoiling. Here, we de...

Centromere protein B, which is involved in centromere formation, binds to centromeric repetitive DNA by recognizing a nucleotide motif called the CENP-B box. Humans have large numbers of CENP-B boxes in the centromeric repetitive DNA of their autosomes and X chromosome. The current understanding is that these CENP-B boxes are located at identical positions in the repeat units of centromeric DNA...

Formation of RNA-DNA hybrid, or R-loop, was studied in vitro by transcribing an AGGAG repeat with T7 RNA polymerase. When ribonuclease T1 was present, R-loop formation in cis was diminished, indicating that the transcript was separated from the template and reassociated with it. The transcript was found to form an R-loop in trans with DNA comprising the AGGAG repeat, when the DNA was supercoile...

INTRODUCTION Advanced gastric carcinoma often decreases quality of life because of upper gastrointestinal tract stenosis. Self-expandable metal stents have been thought to be an effective, minimally invasive treatment for stenosis. However, the effectiveness of self-expandable metal stent placement for carcinomatous stenosis of the gastric body and antrum has not been clarified, and there have ...

Abdominal aortic coarctation is an extremely rare vascular pathology. Its etiology can be congenital or acquired. Here we present a case of acquired infrarenal abdominal coarctation in a 66-year-old woman who complained of low back and legs pain. She had no signs of resting lower limb ischemia, with diminished distal pulses and normal blood pressure in upper and lower extremities. Magnetic reso...

BACKGROUND AND OBJECTIVE Drainage with metallic stents is the treatment of choice in malignant obstructive jaundice. Technical and clinical success with metallic stents is obtained in over 90% and 80% of cases, respectively. There are self-expandable metallic stents designed to increase permeability. The aim of this study was to describe the results obtained with totally covered self-expandable...

This article reviews studies of Fixion expandable nail biomechanical properties in case of long bones fractures osteosynthesis. The purpose of this study was to systematize biomechanical researches dedicated to the expandable nail. There were found seven biomechanical studies published between 2005 and 2008. Among them, six studies are devoted to mechanical experiments, and one is a comment to ...

Nucleotide repeat instability is associated with an increasing number of cancers and neurological disorders. The mechanisms that govern repeat instability in these biological disorders are not well understood. To examine genetic aspects of repeat instability we have introduced an expanded CAG trinucleotide repeat into transgenic mice. We have detected intergenerational CAG repeat instability in...

SUMMARY This paper presents a methodology for designing single-degree-of-freedom expandable " free-form " structures composed of rigid blocks connected through simple cylindrical joints. The underlying idea is to interconnect two or more individually expandable plate structures. Using a two-dimensionally expanding sphere as a first example, the conditions that must be satisfied to preserve the ...