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PubMed1995

Transference and counter-transference variations in the course of the cognitive-analytic therapy of two borderline patients: the relation to the diagrammatic reformulation of self-states.

The cognitive-analytic therapy of two patients with borderline personality disorder is described. Patients and therapists completed post-sessional questionnaires which yielded measures of transference and counter-transference. The relation of changes in these to the sequential diagrammatic reformulation of the patients' self-states is considered.

Adult↗

PubMed1972

Regulation of the tyrosine biosynthetic enzymes in Salmonella typhimurium: analysis of the involvement of tyrosyl-transfer ribonucleic acid and tyrosyl-transfer ribonucleic acid synthetase.

Mutants of Salmonella typhimurium were isolated that require tyrosine for growth because of an altered tyrosyl-transfer ribonucleic acid (tRNA) synthetase. Extracts of one strain (JK10) contain a labile enzyme with decreased ability to transfer tyrosine to tRNA(Tyr) and a higher K(m) for tyrosine than the wild-type enzyme. Strain JK10 maintains repressed levels of the tyrosine biosynthetic enzymes when the growth rate is restricted due to limitation of charged tRNA(Tyr). Several second-site revertants of strain JK10 exhibit temperature-sensitive growth due to partially repaired, heat-labile tyrosyl-tRNA synthetase. The tyrosine biosynthetic enzymes are not derepressed in thermosensitive strains grown at the restrictive temperature. A class of tyrosine regulatory mutants, designated tyrR, contains normal levels of tyrosyl-tRNA synthetase and tRNA(Tyr). These results suggest that charging of tRNA(Tyr) is not necessary for repression. This conclusion is substantiated by the finding that 4-aminophenylalanine, a tyrosine analogue which causes repression of the tyrosine biosynthetic enzymes, is not attached to tRNA(Tyr) in vivo, nor does it inhibit the attachment reaction in vitro. A combined regulatory effect due to the simultaneous presence of tyrS and tyrR mutations in the same strain was detected. The possibility of direct participation of tyrosyl-tRNA synthetase in tyrosine regulation is discussed.

Aldehyde-Lyases↗

PubMed1975

Role of methionyl-transfer ribonucleic acid in the regulation of methionyl-transfer ribonucleic acid synthetase of Escherichia coli K-12.

A decrease in the in vivo acylation level of methionine transfer ribonucleic acid (tRNAmet) induced by methioninyl adenylate led to a specific derepression of methionyl-transfer ribonucleic acid (tRNA) synthetase formation. This derepression required de novo protein synthesis and was reflected by overproduction of unaltered enzyme. Two different strains of Escherichia coli K-12 that have normal levels of methionyl-tRNA synthetase were examined and the derepression of methionyl-tRNA synthetase was observed in both. Moreover, for one of these strains, the relation between the level of methionyl-tRNA synthetase and deacylation level of tRNAmet was established; under the growth conditions used, when more than 25% of tRNAmet was deacylated, methionyl-tRNA synthetase formation was derepressed and the level of derepression became proportional to the amount of tRNAmet deacylated. Concomitantly, the enzyme was subject to specific inactivation as a consequence of which the true de novo rate of derepression of the formation of this enzyme was higher than that determined by measurements of enzyme activity. These studies were extended to strains AB311 and ed2, which had a constitutive enhanced level of methionyl-tRNA synthetase. In these strains no derepression of enzyme formation was observed on reducing the acylation level of tRNAmet by use of methioninyl adenylate.

Adenosine Monophosphate↗

PubMed1996

The conjugal transfer system of Agrobacterium tumefaciens octopine-type Ti plasmids is closely related to the transfer system of an IncP plasmid and distantly related to Ti plasmid vir genes.

We have determined the DNA sequences of two unlinked regions of octopine-type Ti plasmids that contain genes required for conjugal transfer. Both regions previously were shown to contain sequences that hybridize with tra genes of the nopaline-type Ti plasmid pTiC58. One gene cluster (designated tra) contains a functional oriT site and is probably required for conjugal DNA processing, while the other gene cluster (designated trb) probably directs the synthesis of a conjugal pilus and mating pore. Most predicted Tra and Trb proteins show relatively strong sequence similarity (30 to 50% identity) to the Tra and Trb proteins of the broad-host-range IncP plasmid RP4 and show significantly weaker sequence similarity to Vir proteins found elsewhere on the Ti plasmid. An exception is found in the Ti plasmid TraA protein, which is predicted to be a bifunctional nickase-helicase that has no counterpart in IncP plasmids or among Vir proteins but has homologs in at least six other self-transmissible and mobilizable plasmids. We conclude that this Ti plasmid tra system evolved by acquiring genes from two or three different sources. A similar analysis of the Ti plasmid vir region indicates that it also evolved by appropriating genes from at least two conjugal transfer systems. The widely studied plasmid pTiA6NC previously was found to be nonconjugal and to have a 12.65-kb deletion of DNA relative to other octopine-type Ti plasmids. We show that this deletion removes the promoter-distal gene of the trb region and probably accounts for the inability of this plasmid to conjugate.

Agrobacterium tumefaciens↗

PubMed1996

Gene transfer in Mycoplasma arthritidis: transformation, conjugal transfer of Tn916, and evidence for a restriction system recognizing AGCT.

Mycoplasma arthritidis is a rat pathogen causing a severe polyarthritis. The study of its pathogenic mechanisms has been hampered by the lack of genetic systems for use with M. arthritidis. Described here are procedures for genetic transformation of M. arthritidis and conjugal transfer of Tn916 from an enterococcal donor to M. arthritidis. The location of Tn916 insertion sites in the mycoplasmal chromosome was random, suggesting that Tn916 may be useful as an insertional mutagen in this organism. Additionally, a restriction and modification system was identified which presented a strong barrier to gene transfer. For transformation, the restriction system was circumvented by using DNA that was modified in vitro with the appropriate site-specific methylase (AluI).

Conjugation, Genetic↗

PubMedDate not supplied

Plasma concentrations of cholesteryl ester transfer protein in hyperlipoproteinemia. Relation to cholesteryl ester transfer protein activity and other lipoprotein variables.

Cholesteryl ester transfer protein (CETP) mediates an important pathway for reverse cholesterol transport. Concentrations of CETP in fasting plasma were measured by radioimmunoassay in two different groups of hyperlipoproteinemic subjects. Plasma CETP concentrations measured by radioimmunoassay correlated closely with cholesterol ester transfer activity in normal plasma (r = 0.86). In the first group of 58 patients, plasma CETP concentrations were significantly increased, as compared with those in 79 normal subjects and in hypercholesterolemic (+26%) and combined hyperlipoproteinemic (+25%) subjects but were not altered in moderately hypertriglyceridemic subjects. Marked elevations in plasma CETP levels were documented in patients with dysbetalipoproteinemia (+68%) and severe chylomicronemia (+85%). Similar results were obtained in a second population of 50 hyperlipoproteinemic subjects. Significant correlations were found between plasma CETP levels and total cholesterol (r = 0.52), very low density lipoprotein (VLDL) cholesterol (r = 0.63), and apolipoprotein E concentration (r = 0.40). Correction of the lipoprotein phenotype by dietary means resulted in significant reductions in plasma CETP concentrations in patients with chylomicronemia and dysbetalipoproteinemia. In these subjects, plasma high density lipoprotein cholesterol concentrations increased as CETP decreased. These studies indicate that CETP levels increase in association with enhanced peripheral cholesterol transport via low density lipoprotein, beta-VLDL, or chylomicron remnants.

Adult↗

PubMed1994

Use of the rabbit ear artery to serially assess foreign protein secretion after site-specific arterial gene transfer in vivo. Evidence that anatomic identification of successful gene transfer may underestimate the potential magnitude of transgene expression.

BACKGROUND: The development of molecular strategies for the treatment of restenosis has been hindered by low efficiencies of in vivo arterial transfection. Expression of intracellular marker proteins is generally evident in < 1% of vascular smooth muscle cells after in vivo arterial transfection. Efforts to improve the efficiency of in vivo gene transfer have been further impeded by the use of transgenes encoding for intracellular marker proteins, necessitating tissue removal and limiting survey for expression to one point in time. METHODS AND RESULTS: To study gene expression on a serial basis in vivo and determine the relation between a secreted gene product and transfection efficiency after in vivo arterial gene transfer, a method for performing and serially monitoring gene expression in vivo was developed using the central artery of the rabbit ear. Liposome-mediated transfection of plasmid DNA containing the gene for human growth hormone (hGH) was successfully performed in 18 of 23 arteries. Serum hGH levels measured 5 days after transfection ranged from 0.1 to 3.8 ng/mL (mean, 0.97 ng/mL); in contrast, serum drawn from the control arteries demonstrated no evidence of hGH production. Serial measurement of hGH from transfected arteries demonstrated maximum hGH secretion 5 days after transfection and no detectable hormone after 20 days. Despite these levels of secreted gene product documented in vivo, immunohistochemical staining of sections taken from the rabbit ear artery at necropsy disclosed only rare cells in which there was evidence of successful transfection. CONCLUSIONS: These experiments demonstrate a useful method of performing serial in vivo analyses of gene expression after vascular transfection and that anatomic analyses of transfection efficiency may underestimate the potential magnitude of expression in the case of a secreted gene product. These findings have implications for the clinical application of somatic gene therapy because low-efficiency transfection with a gene encoding for a secreted protein may achieve therapeutic effects not realized by transfection with genes encoding for proteins that remain intracellular.

Animals↗

PubMed1971

Transfer of stimulus control: measuring the moment of transfer.

Three severely retarded boys acquired simple form discriminations errorlessly. Each was first taught to press a red key versus a simultaneously present white key. After this discrimination had been established, black figures were superimposed on the red and white keys. Each correct response affected the next trial by delaying the onset of the red stimulus an additional 0.5 sec. Transfer of stimulus control to the figures was indicated when the subjects responded correctly before the onset of the red stimulus. A series of errorless discrimination reversals was accomplished with this technique, during which the number of trials to transfer systematically decreased with successive reversals.

Adolescent↗

PubMed1999

VLDL-bound lipoprotein lipase facilitates the cholesteryl ester transfer protein-mediated transfer of cholesteryl esters from HDL to VLDL.

In recent years, it has been established that lipoprotein lipase (LPL) is partly associated with circulating lipoproteins. This report describes the effects of physiological amounts of very low density lipoprotein (VLDL)-bound LPL on the cholesteryl ester transfer protein (CETP)-mediated cholesteryl ester transfer (CET) from high density lipoprotein (HDL) to VLDL. Three patients with severe LPL deficiency exhibited a strong decrease in net mass CET that was more than 80% lower than that of common hypertriglyceridemic subjects. Recombination experiments showed that this was due to an abnormal behavior of the VLDL fraction. Replacement of the latter by normal VLDL totally normalized net mass CET. We therefore prepared VLDL containing controlled amounts of bound LPL that we used as CE acceptors in experiments involving unidirectional radioisotopic CET measurements. These were carried out either in the absence or in the presence of inhibitors of LPL lipolytic activity. When LPL-induced lipolysis was totally blocked, the stimulating effect of the enzyme on the CETP-dependent CET was only reduced by about 50%, showing that it did not entirely result from its lipolytic action. These data were dependent upon neither the type of LPL inhibitor (E600 or THL) nor the source of CETP (delipidated plasma or partially purified CETP). Thus, in addition to the well-known stimulating effect of LPL-dependent lipolysis on CET, our work demonstrates that physiological amounts of VLDL-bound LPL may facilitate CET through a mechanism partially independent of its lipolytic activity.

Animals↗

PubMed2000

Distribution of phospholipid transfer protein in human plasma: presence of two forms of phospholipid transfer protein, one catalytically active and the other inactive.

Plasma phospholipid transfer protein (PLTP) plays an important role in the maintenance of plasma high-density lipoprotein (HDL) content and remodeling of HDL in the circulation. In the present study we have used different fractionation methods to investigate the distribution of PLTP in human plasma. A novel enzyme-linked immunosorbent assay developed during the study allowed for simultaneous assessment of both PLTP mass and activity in the fractions obtained. Size-exclusion chromatography and plasma fractionation by nondenaturing polyacrylamide gel electrophoresis (PAGE) yielded similar results demonstrating that PLTP associates in native plasma with two distinct particle populations, while ultracentrifugation with high salt leads to detachment of PLTP from lipoprotein particles and loss of a majority of its phospholipid transfer activity. Interestingly, analysis of the size-exclusion chromatography fractions demonstrated that PLTP exists in the circulation as an active population that elutes in the position of HDL corresponding to an average molecular mass of 160+/-40 kDa and an inactive form with an average mass of 520+/-120 kDa. The inactive fraction containing approximately 70% of the total PLTP protein eluted between HDL and low density lipoprotein (LDL). Thus, the two PLTP pools are associated with different types of lipoprotein particles, suggesting that the PLTP activity in circulation is modulated by the plasma lipoprotein profile and lipid composition.

Antibodies, Monoclonal↗

PubMedDate not supplied

[Hydrodynamics-based transfer of human apolipoprotein A-I gene into mice: study of factors involving an efficacy and duration of the transferred gene expression in animals' liver].

Human apolipoprotein A-I gene (apoA-I) plasmid expression vectors were transferred into mice by hydrodynamic injections into tail vein. Two types of expression vectors were used. First one -pCMVcapoAI contains cDNA of apo A-I driven by human cytomegalovirus early gene promoter (CMV). Second one--pAlg contains genomic locus of intron-containing apo A-I under control of own extended 5'-regulatory region (APOAI). Hydrodynamic intravenous injections of both expression vectors led to appearance of human apo A-I mRNA in the liver and human Apo A-I protein in the serum of injected mice. Dynamics of human Apo A-I content in the serum of mice injected by pCMVcapoAI and pAlg were different. When pCMVcapoAI was used, maximal concentration of human Apo A-I protein in the mouse serum was detected one day after injection with following decline to zero level during next two weeks. Under the same conditions injections of pAlg led to maximal level of human Apo A-I concentration in the mouse serum (up to 20 mkg/ml in some animals) on the 5th-7th day of experiment with following graduate decline during several months (human Apo A-I concentration in the serum of oldest analyzed mouse (6 months after injection) was about 25% of its maximal level in the same animal). Levels of human Apo A-I concentration in the mouse serum were compatible after injections of both expression vectors, in spite of much more strong activity of CMV promoter in comparison with APOAI in cultured human hepatoma cells HepG2. We ascribe the revealed difference in dynamics of human Apo A-I expression to delay of apo A-I transcription from pAlg vector, that was confirmed by nested RT-PCR. Significant level and long-term persistence of human Apo A-I in the serum of mice injected by pAlg could be explained by properties of APOAI or (and) exon-intron structure of genomic apo A-I gene. To test the role of APOAI in long-term expression of human Apo A-I in the mice we performed hydrodynamic injections of plasmid vectors containing cDNA of reporter gene encoding luciferase driven by variants of APOAI. No long-term expression of luciferase was found in the livers of injected mice. Therefore, our data suggest the role of exon-intron structure in maintaining of efficient and long-term expression of transferred human apo A-I.

Animals↗

PubMed1985

Murine transfer factor. II. Transfer of delayed hypersensitivity to synthetic antigens.

Synthetic polyaminoacid antigens were used to examine the specificity of transfer of delayed-type hypersensitivity with spleen cell dialysates in mice. Dialysates from GAT10-sensitized donors sensitized recipients to GAT10, but not GLA5 or cytochrome c. Dialysates from GLA5-sensitized donors sensitized recipients to GLA5, but not GAT10 or cytochrome c. We interpret these findings as consistent with the concept that passive transfer of delayed hypersensitivity with dialyzable materials is an immunologically specific event.

Animals↗

PubMed1989

[Embryo transfer in swine in relation to a gene transfer program].

The production of the recommended embryonic stage for microinjection of foreign DNA into pronuclei needs a precisely timed preparation of donor pigs. For oestrus induction 1250 IU of PMSG is used at a body weight of 60 kg to 90 kg. To induce ovulation 750 IU of HCG are injected 3 days later. After two inseminations eggs are collected by surgical flush of the oviducts and centrifuged for 3 min at 15,000 g for visualization of the pronuclei. After DNA-microinjection the embryos are transferred to 12 h asynchronous recipients. About 50% of the collected eggs could be used for our experiments. The number and quality of the recovered eggs was related to the body weight of the donors. An in vivo culture system in the non-ligated pig oviduct was established in order to measure the effects of the distinct steps in microinjection on embryo survival. The survival rate of untreated zygotes was 52%. After centrifugation the rate was reduced to 38% and after microinjection to 12%. Pregnancy rate after 98 transfers was 37% and an average of 3.9 piglets were born per litter.

Animals↗

PubMed1981

Successful passive transfer of resistance to Fasciola hepatica infection in rats by immune serum and transfer factor.

Resistance to Fasciola hepatica was shown by a 64 per cent reduction in fluke recovery compared with control rats was recorded in rats inoculated with serum from sheep experimentally infected with F hepatica. A comparable reduction (55.6 per cent) was obtained using transfer factor prepared from lysed leucocytes of infected rats. No significant reduction was obtained using transfer factor prepared from sheep or calves.

Animals↗

PubMed1995

Suppression of tumorigenicity of breast cancer cells by transfer of human chromosome 17 does not require transferred BRCA1 and p53 genes.

A number of candidate tumor suppressor genes located on the human chromosome 17 are thought to have a role to play in the development of breast cancer. In addition to the p53 gene on 17p13.1 and the BRCA1 gene mapped to 17q12-21, other chromosomal regions for tumor suppressor genes have been suggested to exist on 17p13.3 and both the central and the distal parts of 17q, although definitive functional proof of their involvement in breast cancer tumorigenesis is still lacking. In this report we show that microcell transfer of a human chromosome 17 into wild-type p53 breast cancer cells CAL51 results in loss of tumorigenicity and anchorage-independent growth, changes in cell morphology and a reduction of cell growth rates of the neo-selected microcell hybrids. In the hybrid cells, which express the p53 wild-type protein, only the p- and the distal parts of the q arm of donor chromosome 17 are transferred. Thus, our results provide functional evidence for the presence of one or more tumor suppressor gene(s) on chromosome 17, which are distinct from the p53 and the BRCA1 genes.

Animals↗

PubMed1994

The influence of endosome-disruptive peptides on gene transfer using synthetic virus-like gene transfer systems.

The process by which viruses destabilize endosomal membranes in an acidification-dependent manner has been mimicked with synthetic peptides that are able to disrupt liposomes, erythrocytes, or endosomes of cultured cells. Peptides containing the 20 amino-terminal amino acid sequence of influenza virus hemagglutinin as well as acidic derivatives showed erythrocyte lysis activity only when peptides were elongated by an amphipathic helix or by carboxyl-terminal dimerization. Interestingly, peptides consisting of the 23 amino-terminal amino acids of influenza virus hemagglutinin were also active in erythrocyte lysis. When peptides were incorporated into DNA complexes that utilize a receptor-mediated endocytosis pathway for uptake into cultured cells, either by ionic interaction with positively charged polylysine-DNA complexes or by a streptavidin-biotin bridge, a strong correlation between pH-specific erythrocyte disruption activity and gene transfer was observed. A high-level expression of luciferase or interleukin-2 was obtained with optimized gene transfer complexes in human melanoma cells and several cell lines.

Amino Acid Sequence↗

PubMed1994

Adenovirus-mediated gene transfer in the transplant setting. II. Successful expression of transferred cDNA in syngeneic liver grafts.

These experiments establish a model for gene transfer to transplanted liver grafts ex vivo using adenoviral vectors. Rat liver grafts (n = 8) were harvested, and preserved in UW or lactated Ringer's. The grafts were infected ex-vivo via portal vein perfusion with replication-defective Ad vectors encoding the beta-galactosidase (beta-gal) gene diluted in UW solution. The infected grafts were stored at 4 degrees C for 1 hr, then transplanted into syngeneic hosts. Liver biopsies were taken at 1, 7, and 15 days after transplantation. Infection rate was assessed by histochemical staining for beta-gal. Liver DNA and RNA were assayed for the beta-gal sequences, and recombinant protein production measured at 24 hr and 7 days after transplantation. Under conditions mimicking liver graft cold storage, efficient gene transfer was achieved with an infection rate of 10-15%, as assessed by X-gal staining. Viral DNA and RNA presence in the graft was confirmed; gene expression with protein production were verified by western blots and a functional protein assay. All studies were negative in control livers. Gene expression persisted for at least 2 weeks after transplantation. We conclude that efficient adenovirus-mediated gene insertion and expression of gene products can be accomplished in whole-liver grafts under hypothermic preservation conditions currently used in clinical transplantation.

Adenoviridae↗

PubMed1996

Transmyometrial embryo transfer after difficult immediate mock transcervical transfer.

OBJECTIVE: To evaluate the place of ultrasound-directed transvaginal transmyometrial ET in a protocol using both the transcervical and transmyometrial routes in a step-wise fashion. DESIGN: A prospective descriptive clinical study. SETTING: A university-based assisted conception unit. PATIENTS: Thirteen patients who had difficult or impossible mock transcervical ET immediately before the real transfer. INTERVENTION: Ultrasound-directed transvaginal transmyometrial ET. MAIN OUTCOME MEASURES: Pregnancy and clinical pregnancy. RESULTS: Four patients became pregnant, including three with clinical pregnancies. CONCLUSIONS: In cases in which transcervical ET isd difficult or impossible, transvaginal transmyometrial ET is a viable option. The use of mock transcervical ET immediately before the real transfer would identify patients needing transmyometrial ET.

Cervix Uteri↗