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Biomedical subjects

R Sosnowski

Publications and source records attributed to R Sosnowski.

9 recordsLinked to original sources
PubMed2000

Rapid, high fidelity analysis of simple sequence repeats on an electronically active DNA microchip.

We describe a method for the discrimination of short tandem repeat (STR) alleles based on active microarray hybridization. An essential factor in this method is electronic hybridization of the target DNA, at high stringency, in <5 min. High stringency is critical to avoid slippage of hybrids along repeat tracts at allele-specific test sites in the array. These conditions are attainable only with hybridization kinetics realized by electronic concentration of DNA. A sandwich hybrid is assembled, in which proper base stacking of juxtaposed terminal nucleotides results in a thermodynamically favored complex. The increased stability of this complex relative to non-stacked termini and/or base pair mismatches is used to determine the identification of STR alleles. This method is capable of simultaneous and precise identification of alleles containing different numbers of repeats, as well as mutations within these repeats. Given the throughput capabilities of microarrays our system has the potential to enhance the use of microsatellites in forensic criminology, diagnostics and genetic mapping.

Alleles↗
PubMed2000

Activation of translation in pituitary gonadotrope cells by gonadotropin-releasing hormone.

The neuropeptide GnRH is a central regulator of mammalian reproductive function produced by a dispersed population of hypothalamic neurosecretory neurons. The principal action of GnRH is to regulate release of the gonadotropins, LH and FSH, by the gonadotrope cells of the anterior pituitary. Using a cultured cell model of mouse pituitary gonadotrope cells, alphaT3-1 cells, we present evidence that GnRH stimulation of alphaT3-1 cells results in an increase in cap-dependent mRNA translation. GnRH receptor activation results in increased protein synthesis through a regulator of mRNA translation initiation, eukaryotic translation initiation factor 4E-binding protein, known as 4EBP or PHAS (protein, heat, and acid stable). Although the GnRH receptor is a member of the rhodopsin-like family of G protein-linked receptors, we show that activation of translation proceeds through a signaling pathway previously described for receptor tyrosine kinases. Stimulation of translation by GnRH is protein kinase C and Ras dependent and sensitive to rapamycin. Furthermore, GnRH may also regulate the cell cycle in alphaT3-1 cells. The activation of a signaling pathway that regulates both protein synthesis and cell cycle suggests that GnRH may have a significant role in the maintenance of the pituitary gonadotrope population in addition to directing the release of gonadotropins.

5' Untranslated Regions↗
PubMed1999

[Supra-acetabular cysts of the hip: results of surgical treatment].

Results of surgical treatment for supraacetabular cystic changes in 8 middle-aged females are presented. Complete excision and filling the defect with iliac autografts has been performed, histological examination of the change followed in all cases. No inflammatory, systemic or neoplasmatic changes were identified. Good results were achieved and hip osteoarthritis delayed. Surgery proved useful in treatment for supraacetabular cystic changes in the hip.

Acetabulum↗
PubMed1996

[Our clinical experience with the diagnosis and treatment of Kummell-Verneuille disease].

Pathology and clinical symptoms in 10 patients with Kümmell-Verneuille disease treated in CMKP Orthopaedic Department are presented. Special attention is given to the course of the disease, natural history of vertebral body necrosis and serious neurological complications. Every phase of the disease is radiographically documented. The preferred treatment, both in early and late phase, is posterior fusion embracing adjacent vertebrae. In neurologically complicated cases anterior spinal decompression and perivertebral fusion is recommended.

Adult↗
PubMed1995

[Degenerative spondylolisthesis].

Results of surgical treatment for degenerative spondylolisthesis in 31 patients are presented. Disabling lumbar and radicular pain not responding to conservative treatment was the indication for surgery in all cases. Twenty-six patients underwent neural decompression and segmental fusion; in 5 patients with no radicular symptoms fusion alone has been performed. In 15 patients with partially preserved intervertebral disc the fusion embraced the pedicle and processus transversus, in other 15 with damaged disc posterior fusion was done and in one case intervertebral fusion was performed. In 7 cases of posterior fusion a wire loop was used for internal stabilization of vertebrae. There were 28 good and fair results (91%) and in 3 patients no improvement was attained. The authors conclude surgical treatment according to the indications presented in this paper is the most beneficial mode of treatment for degenerative spondylolisthesis.

Bone Wires↗
PubMed1991

The transcription factor, Egr-1, is rapidly modulated in response to retinoic acid in P19 embryonal carcinoma cells.

The pluripotent murine embryonal carcinoma cell line, P19, differentiates along at least three main pathways under the inductive influence of retinoic acid (RA). The events most critical to the establishment of a particular differentiation pathway must occur early since P19 cells are committed to differentiation pathways after 30 min of exposure to RA (M. W. McBurney, personal communication and our unpublished results). We have, therefore, looked for genes that are induced (or repressed) within 30 min of RA addition and find that Egr-1 is one of these genes. Egr-1 is a transcription factor of the zinc-finger class and is known to transactivate genes after binding to specific oligonucleotide sequences. We describe here the extremely rapid and transient increase of Egr-1 transcript and protein levels in P19 cells after RA addition. Stable induction of Egr-1 transcripts occurred in the presence of protein synthesis inhibitors. Simultaneous addition of RA and cycloheximide did not result in an additive effect. The mechanism of induction with either drug appears to involve relief of a block to transcriptional elongation. The response was more rapid at high RA concentrations and this suggests that the Egr-1 transcription factor could play a role in initiation of differentiation pathways of P19 EC cells.

Animals↗
PubMed1989

[A case of multiple cartilage exostosis of atypical localization].

A case of multiple cartilage exostosis, originating from the transverse process of the second thoracic vertebra in a 16-year old female patient has been described. Because of the symptoms of compression of the brachial plexus and progressive growth, the tumor was surgically removed. The atypical, very rare localization of the tumor created some technical difficulties in planning of the operation. Computerized tomography was helpful in this case and determined the site of origin of the tumor. After surgical treatment, all symptoms subsided.

Adolescent↗
PubMed1989

[Chondrosarcoma of the vertebral column L5--S1].

A case of chondrosarcoma of the spine in a 15-year-old female patient has been described. The tumor was localized within the body of S1 and it partially involved the left wing of the ilium. The radiological condition corresponded with the so-called "ivory vertebra". The symptoms of compression of the cauda equina took the lead. Surgical decompression of the cauda equina was performed and an attempt of resection of the tumor was undertaken but it failed because of extension of the process. The further course of the disease, in spite of radiotherapy, was exceptionally malignant and within several months, the process became generalized.

Adolescent↗