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P Cramer

Publications and source records attributed to P Cramer.

At least 37 records · Page 2Linked to original sources
PubMed1999

Personality, personality disorders, and defense mechanisms.

The prototype approach was used to assess the presence of personality features associated with borderline, narcissistic, histrionic, and psychopathic personality syndromes in a sample of 91 young adults from the Block and Block (1980) longitudinal study. These personality prototypes were found to be related to the use of denial and projection, and especially to the immature manifestations of those defenses, in ways consistent with theory.

Adult↗
PubMed1999

Ego functions and ego development: defense mechanisms and intelligence as predictors of ego level.

This study considers the contribution of two ego functions--intelligence and defense mechanisms--to ego developmental level. Two independent assessments of ego level were related to IQ and defense mechanism use in a sample of 89 young adults. Whereas IQ and defense were themselves found to be unrelated, both variables predicted ego level: The relation with IQ was linear, whereas the relation with defense was curvilinear. In addition, the relation between defense and ego level varied as a function of IQ level. At low levels of IQ, stronger use of Denial and Projection was associated with higher ego levels. At high IQ levels, strong use of Denial was associated with lower ego levels, whereas moderate use of Projection was associated with higher ego levels.

Adult↗
PubMed1999

Gender identity: affected by social change?

To determine whether social changes in attitudes toward the role of men and women have influenced gender identity measures, 60 male and female college students were assessed using both a Thematic Apperception Test measure (May's, 1966, Deprivation/Enhancement measure) and a self-report measure (Bem's, 1974, Sex Role Identity [BSRI]), both of which were developed more than 20 years ago. Although some recent research has found the BSRI to no longer differentiate between men and women (Twenge, 1997; Wilcox & Francis, 1997), this study found significant gender differences for both gender identity measures.1

Journal Article↗
PubMed1998

Preschool antecedents of defense mechanism use in young adults: a longitudinal study.

Preschool antecedents of the use of defense mechanisms were longitudinally studied using data from 90 nursery school children who were again evaluated at age 23. Defense use was determined by coding Thematic Apperception Test (H.A. Murray, 1943) stories with a method previously shown to be reliable and valid. The findings indicated continuity between preschool personality and subsequent defense use for male participants but little continuity for female participants. Young men's use of the age-inappropriate defense of denial was predicted by indications at ages 3-4 of low ego resiliency and psychological difficulties in the areas of emotion, intellect, impulse control, and social interactions.

Adult↗
PubMed1998

Threat to gender representation: identity and identification.

To investigate the effect of a threat to gender identity on the use of defense mechanisms, college students were given false feedback regarding their sex-role identity. Male and female students who were given gender-contrary feedback showed a marked increase in the use of the defense of identification, as compared to students who were given gender-consistent feedback. Further, both affect change and the use of identification was a function of the degree of discrepancy between feedback condition and conscious gender identity.

Adolescent↗
PubMed1997

Structure of the human NF-kappaB p52 homodimer-DNA complex at 2.1 A resolution.

The crystal structure of human NF-kappaB p52 in its specific complex with the natural kappaB DNA binding site MHC H-2 has been solved at 2.1 A resolution. Whereas the overall structure resembles that of the NF-kappaB p50-DNA complex, pronounced differences are observed within the 'insert region'. This sequence segment differs in length between different Rel proteins. Compared with NF-kappaB p50, the compact alpha-helical insert region element is rotated away from the core of the N-terminal domain, opening up a mainly polar cleft. The insert region presents potential interaction surfaces to other proteins. The high resolution of the structure reveals many water molecules which mediate interactions in the protein-DNA interface. Additional complexity in Rel protein-DNA interaction comes from an extended interfacial water cavity that connects residues at the edge of the dimer interface to the central DNA bases. The observed water network might acount for differences in binding specificity between NF-kappaB p52 and NF-kappaB p50 homodimers.

Amino Acid Sequence↗
PubMed1997

Functional association between promoter structure and transcript alternative splicing.

It has been assumed that constitutive and regulated splicing of RNA polymerase II transcripts depends exclusively on signals present in the RNA molecule. Here we show that changes in promoter structure strongly affect splice site selection. We investigated the splicing of the ED I exon, which encodes a facultative type III repeat of fibronectin, whose inclusion is regulated during development and in proliferative processes. We used an alternative splicing assay combined with promoter swapping to demonstrate that the extent of ED I splicing is dependent on the promoter structure from which the transcript originated and that this regulation is independent of the promoter strength. Thus, these results provide the first evidence for coupling between alternative splicing and promoter-specific transcription, which agrees with recent cytological and biochemical evidence of coordination between splicing and transcription.

Alternative Splicing↗
PubMed1997

Engineering of diffraction-quality crystals of the NF-kappaB P52 homodimer:DNA complex.

The eukaryotic transcription factors NF-kappaB P50 and NF-kappaB P52 are closely related members of the Rel family. Growth of diffraction-quality NF-kappaB P52:DNA co-crystals crucially depended on (a) extensive screens for the DNA fragment of optimal length and (b) engineering of the protein based on the two known NF-kappaB P50:DNA co-crystal structures [Müller et al. (1995) Nature 373, 311-317; Ghosh et al. (1995) Nature 373, 303-310]; namely, deletion of 12 C-terminal amino acid residues. These residues are part of the Rel homology region and comprise the nuclear localization signal. The approach might be of general use for the crystallization of other Rel protein: DNA complexes and in our case yielded co-crystals which diffract beyond 2.0 A resolution.

Crystallization↗
PubMed1997

Evidence for change in children's use of defense mechanisms.

Using a cohort-longitudinal design, children's use of the defenses of denial, projection, and identification was assessed at four points over a 2-year time span, covering the age period from 6 years, 6 months to 9 years, 5 months. The results showed a clear decrease in the use of denial from early to middle childhood, a sharp increase in the use of projection, and an increase in the use of identification. These findings, predicted by a theory of defense mechanism development, are consistent with cross-sectional results reported previously.

Age Factors↗
PubMed1997

[Role of different forms of fibronectin in in vitro bovine follicular development].

This study was aimed at testing the hypothesis that different forms of fibronectin (FN), produced as a consequence of the alternative splicing of the precursor mRNA, play specific roles during follicular development. In particular, we analyzed the presence of the ED-I region, which is absent in the plasma form. Analysis of FN levels in follicular fluids corresponding to different stages of development of bovine follicles revealed marked changes in the concentrations of ED-I + FN whereas total FN levels remained relatively constant. A negative correlation (P < 0.001) was detected between ED-I + FN and estradiol levels. This steroid was without effect on the alternative splicing of FN in primary cultures of bovine granulosa cells. However, cAMP produced a marked decrease in the incorporation of the ED-I region. In contrast, transforming growth factor beta (TGF-beta) elicited both a stimulation on overall FN synthesis and an increase in the inclusion of ED-I. This effect was evident at the protein level (Western blots) and also in the mRNAs (Northern blots). A peptide corresponding to the ED-I region stimulated DNA synthesis in a bovine granulosa cell line (BGC-1) whereas the peptide corresponding to the flanking sequences was without effect. Data presented herein suggest a novel form of regulation by which changes in the primary structure of FN may mediate some of the effects of gonadotropin and intraovarian factors during follicular development.

Animals↗
PubMed1996

Structural and energetic responses to cavity-creating mutations in hydrophobic cores: observation of a buried water molecule and the hydrophilic nature of such hydrophobic cavities.

We have solved the 2.0-A resolution crystal structures of four cavity-creating Ile/Leu-->Ala mutations in the hydrophobic core of barnase and compare and contrast the structural responses to mutation with those found for Leu-->Ala mutations in T4 lysozyme. First, there are rearrangements of structure of barnase that cause the cavities to collapse partly, and there is an approximately linear relationship between the changes in stability and the volume of the cavity similar to that found for the mutants of T4 lysozyme. Second, although it is currently accepted that hydrophobic cavities formed on the mutation of large hydrophobic side chains to smaller ones are not occupied by water molecules, we found a buried water molecule in the crystal structure of the barnase mutant Ile76-->Ala. A single hydrogen bond is formed between the water molecule and a polar atom, the carbonyl oxygen of Phe7, in the hydrophobic cavity that is formed on mutation. A survey of hydrophobic cavities produced by similar mutations in different proteins reveals that they all contain a proportion of polar atoms in their linings. The availability of such polar sites has implications for understanding folding pathways because a solvated core is presumed present in the transition state for folding and unfolding. Notably, the hydrogen bond between the cavity-water and the carbonyl group of Phe7 is also a marked early feature of very recent molecular dynamics simulations of barnase denaturation [Caflisch, A., & Karplus, M. (1995) J. Mol. Biol. 252, 672-708]. It is possible that cavities engineered into the hydrophobic cores of other proteins may contain water molecules, even though they cannot be detected by crystallographic analysis.

Amino Acid Sequence↗
PubMed1996

The fibronectin gene as a model for splicing and transcription studies.

The fibronectin (FN) gene has become paradigmatic to illustrate genome evolution by exon shuffling, generation of protein diversity by alternative mRNA splicing, and topological coordination between transcription and splicing. Alternative splicing in three sites of the primary transcript gives rise to multiple FN polypeptides. This process is cell type-, development- and age-regulated. The different FN variants seem to play specific roles in FN dimer secretion, blood clotting, adhesion to lymphoid cells, skin wound healing, atherosclerosis, and liver fibrosis. This review focuses on function assignment to the alternatively spliced segments, as well as on the external signals and cis-acting sequences that control the mechanisms of alternative splicing. We also discuss FN transcriptional regulation in response to viral transformation, growth factors, and cyclic AMP in the light of promoter architecture and its interaction with specific transcription factors. The relevance of FN RNA "tracks" as assembly lines of coordinated transcription and RNA processing is also addressed.

Alternative Splicing↗
PubMed1996

Use of rat and human liver slices for the detection of steroid hormone-induced DNA-adducts in vitro by means of the (32)P-postlabeling technique.

Precision cut liver slices from humans and rats were used to investigate the covalent binding of xenobiotics to the DNA by means of the (32)P-postlabeling technique. Human liver slices were incubated with the structurally related steroid hormones chlormadinone acetate (5 mu g/ml), cyproterone acetate (0.01-5 mu g/ml), megestrol acetate (5 mu g/ml), and the positive control 2-aminofluorene (0.01-5 mu g/ml), which is known for its marked ability to form DNA-adducts in vivo. Rat liver slices were incubated with cyproterone acetate in concentrations of 0.1, 1, and 5 mu g/ml. The functional viability and metabolic activity of the slices were shown to be sufficiently maintained during the incubation time by measurement of the intracellular K(+)-content and the metabolic turnover of the model substrate 7-ethoxycoumarin, respectively. All three test substances and the control induced DNA-adducts in human liver slices, however, with a different adduct pattern. While the total DNA-adduct levels obtained with cyproterone acetate and megestrol acetate were in the same order of magnitude (on average 1000 DNA-adducts/10(9) nucleotides after incubation with 5 mu g /ml), the relative adduct labeling calculated for chlormadinone acetate was about 400. Following in vitro incubation of rat liver slices with cyproterone acetate, the relative adduct labeling values increased proportionally with increasing concentrations and added linearily to in vivo generated DNA-adducts. At the level of liver slices, different DNA-adduct patterns were induced by cyproterone acetate in rat and man. In contrast to the finding of others, using rat hepatocytes, the relative adduct labeling values of cyproterone acetate and megestrol acetate were in the same order of magnitude after incubation with human liver slices. The present study indicates that liver slices are a useful tool to investigate the in vitro DNA-adduct inducing potential of xenobiotics.

Adult↗
PubMed1996

A one year prospective study of the effect of life events and medication in the aetiology of schizophrenic relapse.

BACKGROUND: We set out to determine whether and to what degree life events independent of illness increase the risk of relapse in schizophrenia following withdrawal from medication in the previous 6 months, either by triggering a relapse in the following 4 weeks or by acting cumulatively over time. METHOD: Seventy-one patients fulfilling DSM-III-R criteria for schizophrenia with chronic illness were followed for 48 weeks and assessed on the LEDS scale. Half were treated with regular neuroleptic medication and half had been recently withdrawn from medication. A subgroup was randomised double-blind to treatment or placebo. RESULTS: A proportional hazards regression model showed that life events made a significant cumulative contribution over time (P < 0.05) to the risks of relapse and that ceasing medication made an independent contribution. The risk of relapse increased in proportion to the number of life events but no interaction between medication status and events could be detected, i.e. life events were not more closely associated with relapse on medication than off medication. For those of the sample exposed to the mean rate of life events during the study period, it was estimated that 23% of the relapse risk could be attributed to life events, and for those with twice the mean rate of events, 41%. In contrast, patients who continued on regular medication had 80% less risk of relapse than those who had been withdrawn from medication either by choice or under double-blind controlled conditions. CONCLUSIONS: A contribution of life events to the risk of relapse in schizophrenia was confirmed by this study but the hypothesis that life events trigger relapse was not supported, nor was the hypothesis that life events are more relevant to relapse in patients on maintenance medication than in patients off medication.

Adult↗
PubMed1993

Effects of apomorphine and L-dopa on the parkinsonian bladder.

Neurogenic bladder frequently occurs in Parkinson's disease. Detrusor hyperreflexia is a consequence of nigrostriatal dopamine depletion, whereas the cause of hyporeflexia remains unclear. We compared the results of cystometry and urethral profilometry with and without apomorphine (and L dopa) in 12 idiopathic parkinsonians with urinary disorders free of dopaminergic treatment. Whereas hyperreflexic patients improved with apomorphine, and to a lesser extent with L dopa, these drugs had no effect on hyporeflexic patients. These results confirm the role of dopaminergic lesions in the occurrence of bladder hyperreflexia and the possible implication of nondopaminergic lesions in the occurrence of hyporeflexia.

Aged↗
PubMed1992

The safety and efficacy of zolpidem in insomniac patients: a long-term open study in general practice.

The safety and efficacy of 10 or 20 mg/day zolpidem, a new hypnotic belonging to the imidazopyridine class, were studied over a 180-day period in 96 patients with sleep disorders. The treatment was continued for a further 180 days by 49 of these patients. Follow-up information from 21 patients who discontinued treatment after 180 days showed no rebound insomnia or withdrawal signs. Efficacy of treatment with respect to reduction of sleep onset latency and number of nocturnal wakenings, and improvement in duration of sleep, quality of sleep and morning wakenings was found in nearly 90% of patients and was maintained in those patients who continued treatment for 360 days. This efficacy was achieved with a stable percentage of patients receiving 10 mg/day and 20 mg/day zolpidem from day 30 to the final visit. Zolpidem, therefore, has been shown to be an effective and safe hypnotic, and to be devoid of rebound and withdrawal effects.

Family Practice↗
PubMed1992

Schizophrenics and social judgement. Why do schizophrenics get it wrong?

Videotaped social interactions were shown to a population of schizophrenics and controls who were asked to comment on the emotional state of the principal protagonist. Their free responses were subjected to a content analysis to examine which of three possible explanations of known schizophrenic inaccuracies on this task were responsible: formal thought disorder, selective avoidance of psychological factors, or perceptual/attentional deficits. Neither selective avoidance nor marked thought disorder were found to explain these errors. The schizophrenics as a group rated much the same, irrespective of clinical profile. Their judgements of personality were less clear-cut than the controls.

Adult↗