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Biomedical subjects

P Papp

Publications and source records attributed to P Papp.

At least 19 recordsLinked to original sources
PubMed2002

Modulation of the phototoxic effect of hypericin in human leukemia CEM cell line by N-ethylmaleimide, amiloride and omeprazole.

Hypericin is a photosensitizing plant pigment from Hypericum perforatum with multiple modes of light-induced biological activities due to production of singlet oxygen and/or excited-state proton transfer with consequent pH drop in the hypericin environment. In the present work, we studied the effects of three inhibitors of crucial mechanisms responsible for intracellular pH (pHi) regulation on hypericin phototoxicity: N-ethylmaleimide (NEM), an inhibitor of H+-ATPase, 5'-(N,N-dimethyl)-amiloride (DMA), an inhibitor of Na+/H+ exchanger, and omeprazole (OME), an inhibitor of H+K+-ATPase. Our experiments show that the effect of hypericin at 1 x 10(-5) and 1 x 10(-6) mol x l(-1) was significantly potentiated by NEM (1 x 10(-7)-1 x 10(--9) mol x l(-1)) and DMA (1 x 10(-6) and 1 x 10(-7) mol x l(-1)) in leukemic CEM cell line. On the other hand, OME had no significant effect on hypericin cytotoxicity. Our results support the hypothesis that the excited-state proton transfer and the consequent acidification of hypericin environment could play a role in the biological activity of hypericin.

Amiloride↗
PubMed1998

Integrative promoter cloning plasmid vectors for Rhizobium meliloti.

A set of integrative 'promoter probe' plasmids were constructed for both translational and transcriptional fusions. The vectors are based on the broad host range, low copy number plasmid pRK290 (IncPl) in which the attachment site of Rhizobium phage 16-3 and the lacZ gene of Escherichia coli were combined. The vectors integrate into the chromosome of Rhizobium meliloti, providing also the advantages of the single copy promoter probe cassettes. Thus they fulfil the prerequisite of the systems used for investigating gene regulation. The plasmids were applied for the study of the transcription regulation of the 16-3 phage. Their versatile use is also demonstrated.

Amino Acid Sequence↗
PubMed1998

Kidney transplantation in recipients with mental retardation: clinical results in a single-center experience.

Mental retardation has been a controversial relative contraindication to organ transplantation. Currently, there are few data available in the literature that describe the outcome of kidney transplantation in mentally retarded patients. In a series of 1,271 kidney transplantations performed between January 1968 and March 1996, we identified eight patients (0.6%) with significant mental retardation (IQ < 70). Only cooperative patients supervised by a reliable long-term caregiver, with long life expectancy, and able to take medication under supervision, were accepted as candidates, independent of the IQ level. At a mean follow-up of 7.3 years, seven patients are alive with functioning grafts, and one lost the kidney to chronic rejection 10 years after transplantation and died of sepsis after resuming dialysis. The 1- and 5-year patient and graft survival are thus 100%. Compliance with immunosuppressive treatment and clinical follow-up was excellent in all of the recipients. The patient quality of life and health were judged by the support persons as highly improved after transplantation in comparison to dialysis. We conclude that kidney transplantation in properly selected patients with mental retardation provides excellent patient and graft survival rates and improves quality of life. In such patients, the presence of mental retardation should not be considered a contraindication to kidney transplantation.

Adolescent↗
PubMed1996

Family themes: transmission and transformation.

This article describes a method for doing therapy that uses multisystemic themes that combine meaning and action to facilitate therapeutic change. By identifying central themes that operate at the individual, dyadic, triadic, whole family, intergenerational, and sociocultural levels, the therapist is able to develop effective interview questions and design useful interventions. In this method, behavioral symptoms are framed as a current manifestation of an overarching theme. This orientation enables family and therapist to de-pathologize symptoms and work collaboratively toward change. Case examples from a wide variety of families with differing presenting problems, interactional patterns, three-generational histories, and cultural backgrounds, illustrate the efficacy of the method.

Adolescent↗
PubMed1994

[A comparison of 2 methods of plastic cast fixation in treatment of loco classico radius fracture. A prospective, randomized study].

The purpose of this study was to compare the functional and radiological result of two different positions of the wrist in a plaster cast following Colles' fracture. For this prospective study, each of 50 patients with type A 2.2, A 3.3, C 1.2 or C 2.2 (AO classification) fractures of the radius was randomly assigned to one of two groups. Both groups were treated in the same way as far as anaesthesia and reduction were concerned. The only difference in treatment lay in the position of fixation in plaster. In group 1 the wrist was immobilized in neutral flexion-extension. In group 2 the wrist was dorsiflexed 20 degrees, while the carpus was pushed in a volar direction by an impression in the plaster cast. At review 2-7 years after the accidents, the two groups were compared with reference to symptoms, range of motion at the wrist, power of first closure and radiographic appearance. In group 1 there were 5 patients with significant disability, compared with only 1 in group 2. A significant difference was found in the range of movement between the two groups for flexion and ulnar abduction (p < 0.01). The loss of power of first clenching (difference between injured and healthy hand) was 6.2 mmHg for group 1 and 3.8 mmHg for group 2 (not significant). The radiographic examination showed significant differences both in sagittal inclination (p < 0.001) and in radial shortening (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The bacterial attachment site of the temperate Rhizobium phage 16-3 overlaps the 3' end of a putative proline tRNA gene.

Bacteriophage 16-3 inserts its genome into the chromosome of Rhizobium meliloti strain 41 (Rm41) by site-specific recombination. The DNA regions around the bacterial attachment site (attB) and one of the hybrid attachment sites bordering the integrated prophage (attL) were cloned and their nucleotide sequences determined. We demonstrated that the 51 bp region, where the phage and bacterial DNA sequences are identical, is active as a target site for phage integration. Furthermore it overlaps the 3' end of a putative proline tRNA gene. This gene shows 79% similarity to the corresponding proline tRNA-like genomic target sequence of certain integrative plasmids in Actinomycetes.

Attachment Sites, Microbiological↗
PubMed1991

The isolated N-terminal DNA binding domain of the c repressor of bacteriophage 16-3 is functional in DNA binding in vivo and in vitro.

The 197 amino acid c repressor of the temperate Rhizobium meliloti phage 16-3 still regulates the OR operator of the phage after removal of its carboxyl terminal region. When cloned in the low-copy-number plasmid pGA46, a severely truncated variant (R1-77), which retains only the first 77 amino acids of the intact protein, repressed in vivo transcription from the phage promoter PR. When the R1-77 repressor was fused to E. coli beta-galactosidase, the hybrid protein bound OR operator DNA in vitro. The behavior of fusion proteins derived from a point mutant is consistent with the assignment of DNA binding specificity to the amino-terminal region. Furthermore two repressor alleles bearing ts mutations that mapped in the R1-77 region (near a helix-turn-helix motif) were also temperature sensitive for regulation of the OR site, while an 18 bp "in frame" deletion mutant, which mapped in the carboxyl terminal segment, regulated the OR operator in wild-type fashion. The carboxyl terminal region of the repressor is however necessary for the control of lysogenic development of 16-3.

Alleles↗
PubMed1982

Staging reciprocal metaphors in a couples group.

This paper has described a format for treating couples using the technique of couples choreography to define the marital relationship in metaphorical terms. When the metaphors are acted out, the reciprocity in the relationship is translated into concrete images. These images provide the basis for systemic interventions aimed at disrupting the escalating reciprocity. Prechange tests are used to regulate the speed of change in relation to the reciprocal positions. Change is viewed as an unsettling phenomenon that temporarily unbalances the marital relationship. The group serves as a theatrical setting in which the marital relationships are "staged" and examined with humor and objectivity. An atmosphere of experimentation is created, which is necessary for carrying out the unconventional tasks.

Dominance-Subordination↗
PubMed1980

The Greek chorus and other techniques of paradoxical therapy.

This paper has described some of the interventions developed at the Ackerman Brief Therapy Project in treating the families of symptomatic children. The interventions are based upon a differential diagnosis of the family system and upon an evaluation of that system's resistance to change. They are classified as compliance-based or defiance-based, depending upon the family's degree of anxiety, motivation, and resistance. Paradoxical interventions, which are defiance-based, are used as a clinical tool in dealing with resistance and circumventing the power struggle between therapist and family. A consultation group acting as a Greek chorus underlines the therapist's interventions and comments on the consequences of systemic change. This group is also sometimes used to form a therapeutic triangle among the family, therapist and group, with the therapist and group debating over the family's ability to change.

Child↗