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S Heck

Publications and source records attributed to S Heck.

25 records · Page 2Linked to original sources

A new efficient gene disruption cassette for repeated use in budding yeast.

The dominant kanr marker gene plays an important role in gene disruption experiments in budding yeast, as this marker can be used in a variety of yeast strains lacking the conventional yeast markers. We have developed a loxP-kanMX-loxP gene disruption cassette, which combines the advantages of the heterologous kanr marker with those from the Cre-lox P recombination system. This disruption cassette integrates with high efficiency via homologous integration at the correct genomic locus (routinely 70%). Upon expression of the Cre recombinase the kanMX module is excised by an efficient recombination between the loxP sites, leaving behind a single loxP site at the chromosomal locus. This system allows repeated use of the kanr marker gene and will be of great advantage for the functional analysis of gene families.

Base Sequence↗

Interaction of the Ubc9 human homologue with c-Jun and with the glucocorticoid receptor.

Glucocorticoid hormones convert the glucocorticoid receptor (GR) from an inactive cytosolic complex to a nuclear form that regulates transcription. Binding of GR to palindromic DNA-recognition sites (hormone response elements) leads to activated target gene transcription. GR also exerts negative actions on transcription, e.g., by interfering with the function of several other transcription factors such as AP-1, NK-kappa B, CREB, and Oct-1. Physical interactions of GR with AP-1 subunits are readily detectable but do not seem sufficient since nonrepressing GR mutants still interact in vitro, so that specific conformational changes and/or interactions with additional partner proteins may be required for negative action. In an attempt to find such partner proteins, we defined regions of c-Jun and GR essential for mutual interference and used in those a yeast two-hybrid screen for interacting proteins. Repeatedly we isolated overlapping cDNA sequences of one protein interaction with both c-Jun and GR. This protein does not interact with c-Fos or a non-repressing GR mutant and expressed in mammalian cells does not substantially affect AP-1 or GR activity. Interestingly, however, the protein rescues yeast cells from the toxic effects of the GR fragment used for screening. The protein represents the human homologue of the yeast E2 ubiquitin-conjugating enzyme, Ubc9; its specific interactions with both GR and c-Jun, but not mutant GR, suggest that it may exert physiologic regulatory functions.

Animals↗

Pain dysfunction syndrome of the knee.

Pain dysfunction syndrome is a descriptive term recommended by Amadio to describe patients whose pain is excessive, nonanatomic, and out of proportion to their injury. This retrospective review reports the effectiveness of a differential epidural block in the evaluation of these patients. Four patterns of response were identified with the block: 1) reflex sympathetic dystrophy (RSD) (14%), 2) somatic (9%), 3) mixed sympathetic and somatic (27%), and 4) central (50%). The inciting injury in 70% of the patients was a minor strain, sprain, or contusion. Despite accurate diagnosis, the results in compensation cases with pain dysfunction syndrome are exceedingly poor.

Adolescent↗

A distinct modulating domain in glucocorticoid receptor monomers in the repression of activity of the transcription factor AP-1.

Steroid receptors activate and repress genes. An important class of genes that they repress is controlled by the transcription factor AP-1. The activity of AP-1 is inhibited by the receptor, a mechanism exploited for the therapy of various forms of pathological hyperproliferation in humans. We show here by point mutations in the DNA binding domain and by the choice of steroid ligands that repression of AP-1 activity and transactivation functions of the glucocorticoid receptor (GR) are separable entities. While DNA binding and activation of glucocorticoid-regulated promoters require GR dimerization, we present data that suggest that repression is a function of GR monomers.

Amino Acid Sequence↗

Financial modeling/case-mix analysis.

The authors describe a case mix system developed by users which goes beyond DRG requirements to respond to management's clinical/financial data needs for marketing, planning, budgeting and financial analysis as well as reimbursement. Lessons learned in development of the system and the clinical/financial base will be helpful to those currently contemplating the implementation of such a system or evaluating available software.

Computers↗

Long-term followup of anterior cruciate ligament reconstruction using freeze-dried fascia lata allografts.

We identified 79 patients who underwent arthroscopically assisted intraarticular anterior cruciate ligament reconstruction with freeze-dried fascia lata allografts and an additional lateral extraarticular reconstruction. We were able to contact 62 patients (79%) for follow-up evaluation at an average of 134.5 months. Forty patients (51%) returned for objective evaluation. Lysholm scores at followup averaged 92.3 and Tegner activity scores averaged 5.1. Only four (6%) of the 62 patients contacted reported episodes of full giving way. Thirty (75%) of the 40 patients examined demonstrated 3 mm or less side-to-side difference on KT-1000 arthrometer manual maximum evaluation. Forty-eight (77%) of the 62 patients were participating in sporting activities at final followup. No patient had evidence of graft rejection.

Adult↗