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At least 883 records · Page 49Linked to original sources
PubMed1996

Fos and Jun bend the AP-1 site: effects of probe geometry on the detection of protein-induced DNA bending.

The effect of Fos and Jun binding on the structure of the AP-1 recognition site is controversial. Results from phasing analysis and phase-sensitive detection studies of DNA bending by Fos and Jun have led to opposite conclusions. The differences between these assays, the length of the spacer between two bends and the length of the sequences flanking the bends, are investigated here using intrinsic DNA bend standards. Both an increase in the spacer length as well as a decrease in the length of flanking sequences resulted in a reduction in the phase-dependent variation in electrophoretic mobilities. Probes with a wide separation between the bends and short flanking sequences, such as those used in the phase-sensitive detection studies, displayed no phase-dependent mobility variation. This shape-dependent variation in electrophoretic mobilities was reproduced by complexes formed by truncated Fos and Jun. Results from ligase-catalyzed cyclization experiments have been interpreted to indicate the absence of DNA bending in the Fos-Jun-AP-1 complex. However, truncated Fos and Jun can alter the relative rates of inter- and intramolecular ligation through mechanisms unrelated to DNA bending, confounding the interpretation of cyclization data. The analogous phase- and shape-dependence of the electrophoretic mobilities of the Fos-Jun-AP-1 complex and an intrinsic DNA bend confirm that Fos and Jun bend DNA, which may contribute to their functions in transcription regulation.

Base Sequence↗
PubMed2005

Separation of small peptides by electrochromatography on silica-based reversed phases and hydrophobic anion exchange phases.

Peptide separations are regarded as a promising application of capillary electrochromatography (CEC) and, at the same time, a suitable model to elucidate its mixed separation mechanism when charged analytes are involved. In this paper, studies on the separation of small peptides (2-4 amino acids) on a Spherisorb octadecyl silane (ODS) phase at acidic pH and on a strong anion exchange (SAX)/C18 mixed mode phase at weakly basic pH are reported. For the ODS phase a comparison of CEC, capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC) under identical buffer/eluent conditions is presented. The predicted retention factors for CEC under the assumption of simple superposition of HPLC retention and CZE migration matched the measured results for the peptides that had small retention factors in HPLC. For both types of stationary phases, a variation of the acetonitrile content in the mobile phase led to a wide range of retention factors, including negative values when co-electroosmotic migration was dominant. Though both the ODS and the SAX/C18 phase offer unique advantages, the SCX/C18 phase at pH 9 provides more flexibility to alter separation selectivity for the selected peptides.

Acetonitriles↗
PubMed2006

Indium flux synthesis of RE4Ni2InGe4 (RE = Dy, Ho, Er, and Tm): an ordered quaternary variation on the binary phase Mg5Si6.

The quaternary compounds RE4Ni2InGe4 (RE = Dy, Ho, Er, and Tm) were obtained as large single crystals in high yields from reactions run in liquid In. The title compounds crystallize in the monoclinic C2/m space group with the Mg(5)Si(6) structure type with lattice parameters a = 15.420(2) A, b = 4.2224(7) A, c = 7.0191(11) A, and beta = 108.589(2) degrees for Dy4Ni2InGe4, a = 15.373(4) A, b = 4.2101(9) A, c = 6.9935(15) A, and beta = 108.600(3) degrees for Ho4Ni2InGe4, a = 15.334(7) A, b = 4.1937(19) A, c = 6.975(3) A, and beta =108.472(7) degrees for Er4Ni2InGe4, and a = 15.253(2) A, b = 4.1747(6) A, c = 6.9460(9) A, and beta = 108.535(2) degrees for Tm4Ni2InGe4. RE4Ni2InGe4 formed in liquid In from a melt that was rich in the rare-earth component. These compounds are polar intermetallic phases with a cationic rare-earth substructure embedded in a transition metal and main group matrix. The rare-earth atoms form a highly condensed network, leading to interatomic distances that are similar to those found in the elemental lanthanides themselves. The Dy and Ho analogues display two maxima in the susceptibility, suggesting antiferromagnetic ordering behavior and an accompanying spin reorientation. The Er analogue shows only one maximum in the susceptibility, and no magnetic ordering was observed for the Tm compound down to 2 K.

Journal Article↗
PubMed2005

Ethnic variations in the initial phase of mental health treatment: a study of Sami and non-Sami clients and therapists in northern Norway.

Several studies indicate that mental health and mental health service vary with ethnicity. Ethnically linked social differences affect these results. We examined the multiethnic population in northern Norway where social inequalities between the Sami and the non-Sami population are not prominent. Clients (N=347) and therapists (N=32) in outpatient treatments reported demographics, ethnicity and the therapeutic alliance. Clients also reported pretreatment psychosocial status, service utilization and the type of help requested. Therapist recorded clinical and diagnostic assessments and treatment plans. The Sami and non-Sami client groups were similar in demographics and pretreatment psychosocial characteristics. However, the therapists prescribed more sessions and more socially focused interventions when clients were Sami. Verbal therapy was more often used by the non-Sami therapists. Alliance ratings were positively correlated only between Sami therapists and their clients, and Sami therapists rated the largest initial clinical improvement. Clinics located in the high Sami density areas offered their clients more therapy sessions, than in clinics in the high non-Sami density areas. Ethnic similarity between client and therapist were associated with more frequent use of medication and less frequent use of verbal therapy.

Adult↗
PubMed1993

Daily intervals of heat exposure alter the phase of the daily variation of plasma hormones in Holtzman rats.

The effects of timed daily increases in ambient temperature (thermopulses) (from 22 +/- 1 to 40 +/- 1 degree C for 2 h) on daily variations of hormones involved in glucose and lipid metabolism were tested in male Holtzman rats (3-4 mo old) exposed to a 12-h daily photoperiod. The thermopulses were administered for 14 days either at light onset (TP0) or 16 h after light onset (TP16). Body weights and food consumption were monitored during the experiment. Retroperitoneal fat weights and plasma concentrations of insulin, glucose, glucagon, corticosterone, and prolactin were determined from blood taken every 4 h during a 24-h period commencing 24 h after the last thermopulse. TP0 treatment did not alter any of the parameters tested. Conversely, TP16 treatment obliterated the daily rhythms of insulin and corticosterone present in the controls (nonthermopulsed) and decreased body weight gains, retroperitoneal fat stores, food consumption, and the baseline levels of plasma insulin and corticosterone. The present study supports a role for circadian neuroendocrine rhythms in the reduction of fat stores induced by properly timed daily thermopulses.

Acclimatization↗