The guanine-quadruplex structure in the human c-myc gene's promoter is converted into B-DNA form by the human poly(ADP-ribose)polymerase-1.

The important regulatory role of the guanine-quadruplex (GQ) structure, present in the nuclease hypersensitive element (NHE) III(1) region of the human c-myc (h c-myc) gene's promoter, in the regulation of the transcription of that gene has been documented. Here we present evidences, that the human nuclear poly(ADP-ribose)polymerase-1 (h PARP-1) protein participates in the regulation of the h c-myc gene expression through its interaction with this GQ structure, characterized by binding assays, fluorescence energy transfer (FRET) experiments and by affinity pull-down experiments in vitro, and by chromatin immunoprecipitation (ChIP)-qPCR analysis and h c-myc-promoter-luciferase reporter determinations in vivo. We surmise that h PARP-1 binds to the GQ structure and participates in the conversion of that structure into the transcriptionally more active B-DNA form.

Assessment of radiolucent lines around the Oxford unicompartmental knee replacement: sensitivity and specificity for loosening.

The Oxford unicompartmental knee replacement gives good results in patients with symptomatic osteoarthritis of the medial compartment. Previous studies have suggested that the presence of radiolucent lines (RLLs) does not reflect a poor outcome in such patients. However, the reliability and validity of this assessment have not been determined.

Valvular heart disease in osteogenesis imperfecta: presentation of a case and review of the literature.

Osteogenesis imperfecta (OI) is a rare inheritable disorder of connective tissue. While musculoskeletal abnormalities are well known, cardiovascular involvement is rare. Aortic root dilation is the most common cardiovascular manifestation.

Echocardiography. The role of this noninvasive test in the geriatric population.

Echocardiography assumes a major role in the diagnosis and evaluation of cardiovascular disease in the older population. Available diagnostic modalities are briefly reviewed and their role in identifying disease entities common in a geriatric population is discussed. The prognostic implications of echocardiographic findings of mitral annular calcification and aortic sclerosis are reviewed, as are the use of echo and Doppler techniques in the assessment of congestive heart failure.

Radiation-induced cardiovascular dysfunction.

Coronary artery disease and valvular dysfunction are long-term complications of mediastinal irradiation. We describe 3 patients who underwent successful combined coronary artery bypass grafting and valve replacement for symptoms related to radiation-induced coronary artery and valvular disease.