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Results for “Indirect transfer”

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At least 19 recordsLinked to original sources

PubMed2026

A rare and atypical case of long-distance indirect DNA transfer: Contamination from an investigator never present at the scene.

To maximize the usefulness of DNA obtained from biological samples in forensic genetics, it is crucial to avoid DNA contamination throughout all procedures, from sample collection at crime scenes to STR profile generation in DNA laboratories. This study reports a rare and atypical case of DNA contamination in a forensic setting. During the analysis of biological evidence from a cold case preserved for 18 years, the STR profile obtained from the surface of a plastic bag matched that of an investigator, identified through the DNA elimination database. Case reconstruction confirmed that the investigator-who was located 80 km from the DNA laboratory and had never entered the crime scene or the sample storage room-was not a suspect and that the obtained STR profile originated from contamination. The most plausible explanation for the contamination was indirect transfer: investigator's DNA had adhered to a colleague's clothing and was subsequently dislodged and deposited onto the surface of the plastic bag as the colleague approached the sample pretreatment area. This study integrates trace DNA profiling of challenged samples with rapid contamination investigation and proposes prevention and control measures. This case underscores that, although DNA is widely regarded as the "gold standard" in forensic genetics, its interpretation must be considered within the context of the entire case. Conclusions should not be drawn based solely on a single DNA result.

Humans↗

PubMed1976

Transfer of substrates across the chloroplast envelope.

The chloroplast represents a relatively autonomous metabolic compartment within the plant cell. It is surrounded by an envelope consisting of two membranes of which the inner membrane is the functional barrier. Utilizing the energy of light the chloroplast is able to synthesize dihydroxyacetonephosphate from carbon dioxide and water. To provide the cell with this substrate, inorganic phosphate is required. In the case of phosphate deficiency the product of CO2 fixation may be temporarily stored within the chloroplast as starch. Specific transport processes across the inner envelope membrane permit the transfer of metabolites between the chloroplast and the cytosol. The phosphate translocator facilitates the export of dihydroxyacetone phosphate in exchange for inorganic phosphate. It also catalyzes a shuttle for inorganic phosphate with 3-phosphoglycerate, permitting the indirect transfer of reducing equivalents and of ATP from the chloroplast to the cytosol. The dicarboxylate carrier transporting various dicarboxylates may be suited for the transfer of reducing equivalents from the cytosol into the chloroplast. The ATP translocator, catalyzing a transport of ATP into the chloroplast in exchange for ADP, appears to be important for providing the chloroplast with ATP during the night phase, as required for the mobilization of starch.

Biological Transport↗

PubMed1976

The indirect deltopectoral flap.

A method of indirect transfer of the deltopectoral flap is described to repair craniofacial defects out of reach of the conventional direct flap.

Aged↗

PubMed1978

Bacille Calmette-Guérin infection in the mouse. Regulation of macrophage plasminogen activator by T lymphocytes and specific antigen.

High levels of plasminogen activator (PA) were induced in mouse peritoneal macrophages by infection with BCG, 2-6 X 10(7) viable organisms intravenously, followed 3-4 wk later by intraperitoneal challenge with purified protein derivative (PPD) 2 days before harvest. Macrophages obtained from infected animal without boosting showed little fibrinolytic activity, but challenge of Bacille-Calmette-Guèrin (BCG)-primed peritoneal cells with PPD in culture also enhanced macrophage PA 4- to 10-fold. Stimulation of macrophage PA by PPD depended on specifically sensitized thymus-derived (T) lymphocytes because it was abolished by pretreatment of BCG-primed peritoneal cells with anti-thy 1.2 antiserum and complement. A direct assay was developed in which nylon wool separated sensitized lymphocytes and PPD induced PA in macrophages from uninfected animals under defined conditions on 125I-fibrin. Enhanced macrophage fibrinolysis was proportional to concentration of PPD and the number of sensitized lymphocytes transferred. An indirect two-stage assay was also used to show that BCG-sensitized peritoneal cells released a soluble inducer of macrophage PA into the culture medium, after challenge with PPD. Induction of macrophage PA by PPD challenge in vitro made it possible to study the generation and activity of sensitized peritoneal lymphocytes at different stages of infection. Our results show that nonadherent peritoneal cells of BCG-infected mice provide a rich source of specifically sensitized lymphocytes and that macrophage activation is limited by continued availability of antigen, as well as sensitized lymphocytes. Induction of macrophage PA provides a sensitive, versatile, and rapid in vitro assay to study the role of lymphocytes and specific antigen in macrophage activation by BCG.

Animals↗

PubMed1975

Polymyxin B reactions, IgE antibody, and T-cell deficiency. Immunochemical studies in a patient after bone marrow transplantation.

A patient with aplastic anemia was immunosuppressed with cyclophosphamide and transplanted with allogenic bone marrow. While lacking demonstrable T-cell activity posttransplantation, he developed a generalized macular erythematous eruption and fever, clinically attributed to intranasal polymyxin B. A specific IgE antibody, demonstrated by direct skin testing, Prausnitz-Kustner passive transfer, and indirect passive hemagglutination was temporally related to the reaction. Discontinuation of the drug led to prompt defervescence and resolution of the drug eruption.

Adolescent↗

PubMed1976

Arrangement and conformations of substrates at the active site of pyruvate kinase from model building studies based on magnetic resonance data.

Seventeen distances from two paramagnetic reference points, as determined by nuclear relaxation studies of six active complexes of rabbit muscle pyruvate kinase, have been used to construct molecular models of two composite enzyme complexes. In the model of the hypothetical pyruvate kinase-M(I)-M(II)-ATP-Cr(III)-P-enolpyruvate complex, overlap of the transferred phosphoryl groups of the two substrates, which is required to explain the observed competition, is incomplete, allowing greater than or equal to 1 A for the transition state to form. In the active enzyme-M(I)-M(II)-ATP-Cr(III)-pyruvate complex, the gamma-phosphoryl phosphorus of ATP is in molecular contact (3.0 +/- 0.5 A) with the carbonyl oxygen of pyruvate, consistent with direct phosphoryl transfer, indicating no need for intermediate phosphorylation of the enzyme. The enzyme-bound divalent cation, which forms second sphere complexes with the phosphoryl groups of P-enolpyruvate and ATP, may activate the transferred phosphoryl group indirectly, through a water ligand. By analogy with the position of Cr(III), a second divalent cation may participate more directly by coordination of the triphosphate chain of ATP.

Adenosine Triphosphate↗

PubMed1979

From the hospital to the prison: a step forward in deinstitutionalization?

In Massachusetts there is a growing trend to transfer both direct and indirect mental health service delivery from civil mental hospitals to prison facilities. Three factors associated with deinstitutionalization and a community-based delivery system appear to have contributed to the trend. Those factors are the over-all compromising of programming caused by unitization of state hospitals and the requirement that a full range of psychiatric services be available in every community, the decrease in morale and training of state hospital employees not involved in community treatment, and the lack of outreach to patients in the community who are dangerous or difficult to deal with.

Adult↗

PubMed1978

Ontogeny of B-lymphocyte function. V. Thymus cell involvement in the functional maturation of B-lymphocytes from fetal mice transferred into adult irradiated hosts.

Lethally irradiated mice reconstituted with adult thymus cells and neonatal or fetal liver cells produce an anti-2,4-dinitrophenyl or anti-bovine gamma globulin response of restricted heterogeneity of affinity in comparison with the response of mice reconstituted with B cells from adult donors. In addition, mice reconstituted with day 15 fetal B cells and adult thymus cells produce relatively few indirect plaque-forming cells (PFC). It was found that B cells acquire the capacity to produce a heterogeneous response, of predominantly indirect PFC within 7 days of transfer only when thymus cells are transferred along with the B cells. B cells from fetal or neonatal donors transferred without young adult thymus cells develop the capacity to generate indirect PFC within 13 days after transfer to adult recipients, but continue to produce a response of restricted heterogeneity of affinity for up to 28 days after transfer. Thus, it has been shown that cells present in the thymus facilitate, or are necessary for the functional maturation of B lymphocytes. Furthermore, the data suggest that maturation of the B-cell population to produce a heterogeneous response is controlled independently of its maturation to be capable of producing indirect PFC.

Aging↗

PubMed1976

Hypothalamic-pituitary control of perinatal prolactin secretion in Macaca mulatta.

Sequential changes in maternal and fetal plasma and amniotic fluid concentrations of prolactin (PRL) and growth hormone (GH) were examined after these intravascular administration of thyrotropin releasing hormone (TRH) or L-dopa alone or combined directly to the near-term Rhesus fetus. The neonatal plasma responses to these same stimuli were also examined. Fetal and neonatal plasma PRL levels increased immediately after TRH injection and remained elevated from baseline levels (102-800%) throughout the 45 min sampling period. Maternal plasma PRL levels also increased markedly. Although amniotic fluid concentrations were more variable, the trend was an increase. After L-dopa injection, fetal and neonatal plasma PRL values declined 26-62% from baseline levels. Maternal plasma PRL concentrations also declined 30-50%, but amniotic fluid PRL concentrations progressively increased. When L-dopa and TRH were administered together, fetal plasma PRL levels declined 14-40% from initial levels, but maternal plasma PRL levels did not change in a consistent manner, and amniotic fluid PRL levels remained stable. There was no change from baseline fetal or neonatal plasma GH concentrations in these experiments. The plasma PRL responses of the primate conceptus to these stimuli are consistent with those found in the adult; the unresponsiveness of plasma GH is not. The direction and magnitude of changes in both maternal plasma and amniotic fluid PRL concentrations provide indirect evidence of placental transfer of TRH and L-dopa in some experiments, and require a biophysical explanation not apparent in others.

Amniotic Fluid↗

PubMed1975

IgE antipolymyxin B antibody formation in a T cell-depleted bone marrow transplant patient.

The production of IgE-class antibody specific for polymyxin B is documented in an 18-year-old white female acute myelocytic leukemic patient in relapse. The patient was rendered T cell-deficient by total body X-irradiation and antihuman thymocyte globulin for the purpose of bone marrow transplatation. Thereafter, symptoms of nasal congestion, rhinorrhea, and perinasal urtication produced by topical application of a polymyxin solution were noted. Reaginic activity mediated by an IgE antibody against polymyxin is documented by Prausnbitz-Küstner-type passive transfer reactions and by an indirect hemagglutination technique developed for these studies. The occurrence of type I hypersensitivity to this topical antibiotic is rare. It is speculated that pharmaceuticals normally having a low sensitizing potential might demonstrate increased reaginic immunogenicity in a spontaneously or iatrogenically T cell-depleted patient.

Adolescent↗

PubMed1975

Relationship between Fc receptors, antigen-binding sites on T and B cells, and H-2 complex-associated determinants.

The relationship between H-2 complex-associated determinants, Fc receptors, and specific antigen-recognition sites on T and B cells was examined by binding and functional assays. The Fc receptor was detected by radiolabeled immune complexes or aggregated human IgG. Both these reagents selectively bound to B cells, not to T cells. When spleen cells, from mice primed to several antigens, were exposed to highly substituted radioactive aggregates, their capacity to transfer both a direct and indirect plaque-forming cell response to these antigens was abrogated. Addition of B cells, but not of T cells, restored responsiveness. Complexed Ig binding to Fc receptors was prevented by pretreatment of mixed lymphoid cell populations with antisera directed against membrane components on the same cell (e.g., H-2) and on other cells (e.g., theta). The lack of specificity of inhibition was thought to be due to the formation on cell surfaces of antigen-antibody complexes which would then attach to the Fc receptor during the incubation precedure. Specific blockade of the Fc receptor during the incubation procedure. Specific blockade of the Fc receptor however occurred when B cells were pretreated with the Fab fragments of anti-H-2 antibody. This was demonstrated autoradiographically and by inhibition of aggregate-induced suicide. The blocking activity of ante-H-2 Fab was removed by absorption with spleen cells from thymectomized irradiated mice but not with thymus cells of appropriate specificity. This suggested that the antibodies involved had specificity for determinants on the B-cell membrane distinct from those coded by the K or D end of the H-2 complex, and either absent from, or poorly represented on, thymus cells. Specific antigen-induced suicide of B cells was achieved simply by incubating the cells with radioactive antigen in the cold. T-cell suicide on the other hand required that the 125I-labeled antigen be presented to the T cells at 37 degrees-C on the surface of spleen cells from antigen-primed mice. Pretreatment of T cells with the Fab fragment of anti-H-2 antibody protected them from the suicide effect. By contrast no such protection of B cells could be achieved by this procedure. In other words H-2 (? Ir)-associated determinants may not only be in close proximity to the antigen-binding site on T cells but, in addition, may be involved in the effective operation of the receptor.

Animals↗

PubMed1979

[F' transfer from Escherichia coli to Proteus mirabilis].

The task of this work was the establishment of an effective transfer system for F'-plasmids from Escherichia coli to Proteus mirabilis. It is shown that cells of PG VI act as recipients in crosses with E. coli F' strains but with a low transfer rate of the plasmid. The presumption that a restriction -- modification system in P. mirabilis was the only reason for the low transfer could not be confirmed. An indirect selection method was developed to isolate P. mirabilis cells which are better recipients. Conjugation experiments showed that the isolated mutants had a better recipient capacity (increase of about 100). This is true not only for the transfer of a F'-plasmid but also for a R-plasmid. The stability of these plasmids in the mutant cells, however, was much lower than in the wild type.

Conjugation, Genetic↗

PubMed1975

Tumour-associated transplantation antigen in sera of rats with large RSV-induced sarcomas.

A factor inhibiting tumour growth in syngeneic hosts was found in the sera of inbred Lewis rats carrying Rous sarcoma virus-induced tumour (RSL). The findings presented here suggest that the serum factor is a tumour-associated transplantation antigen (TATA) shed from the neoplasm into the circulation. All the tumour bearers' sera tested with RSL cells were negative in indirect membrane immunofluorescence;however, on passive transfer into syngeneic rats, they protected the animals against the growth of an RSL tumour inoculum. A similar protective effect was also observed after injection of TATA prepared from RSL cell membranes by solubilization with potassium cholate. When incorporated into Freund's adjuvant, tumour-bearers' sera immunized the animals against a subsequent RSL sarcoma graft. Sera collected from immunosuppressed rats bearing large sarcomas which presumably contain neither tumour-specific antibody nor antigen-antibody complexes, transferred inhibition of tumour growth to syngeneic hosts. Intact immunological reactivity of recipients was a necessary prerequisite for the protective effect of sera, since the passive transfer of an inhibitory serum to immunosuppressed rats did not inhibit tumour growth. We assume that the TATA present in tumour-bearers' serum is released from the growing neoplasm as a result of either cell death or membrane metabolic turnover.

Animals↗

PubMed1976

Temperature gradients and prediction of flap viability.

This study validates a simple clinical method used to determine optimum time for flap transference. Temperature was used as an indirect measurement to determine blood flow. By means of a needle thermocouple, temperature differences in a variety of flaps were measured. Differences between the base and most distal portion from the blood supply were recorded. The method was first developed on the dog and then applied to patients. It was found that temperature differences of 2.5 degrees C or less insured flap success. Greater temperature differences increased the chance of necrosis.

Animals↗

PubMed1976

Detection of complement-dependent antibody to tumor cells in sera of strain-2 guinea pigs cured of their tumors by BCG Treatment.

Sera of strain-2 guinea pigs (cured of line-10 tumor by BCG therapy) were tested for complement-dependent, cytotoxic antibody. About 30% of the sera tested contained significant cytotoxic acitivity with the addition of human, but not syngeneic, complement. Using papain pretreated line-10 cells, we detected antibody in about 50% of the sera with syngeneic sera as the source of complement. Antibody to line-10 was also demonstrated in selected sera by indirect fluorescence and the C1 fixation and transfer test.

Animals↗

PubMed1979

Hormonal regulation in two rat mammary cancer cell lines: glucocorticoid and androgen receptors.

We have studied the hormonal control of two continuous cell lines derived from rat-mammary tumors induced by two different carcinogens (dimethylbenzanthracene and N-nitrosomethylurea). The steroid receptors were assayed using charcoal or hydroxyapatite and the effect of different hormones on cell growth was evaluated by measuring total DNA and following the growth of transplanted cells in nude mice. Similar results were found for the two cell lines; they were unresponsive to estrogen since they did not contain appreciable amounts of estradiol receptor. Conversely, these two cell lines contained high concentrations of androgen and glucocorticoid receptors, which were both transferable to the nucleus. While dexamethasone stimulated, directly or indirectly, the growth of RBA and NMU cells, the effect of androgens on cell growth is still questioned. These two cell lines offer a potential model to study the mechanism of action of androgens and glucocorticoids in mammary cancer.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1976

ABO hemolytic disease in Puerto Rico and North Carolina.

A prospective study was carried out at the University of Puerto Rico Hospital (UPRH) and at the North Carolina Baptist Hospital (NCBH) in order to establish the incidence of ABO hemolytic disease (ABO HD) in the two populations and to determine the relationship of intestinal parasitic infection of the mother to ABO HD in the infant. The incidence of ABO HD among UPRH at risk pregnancies (type O mother with type A or B infant) was 28.3% or 1 in 3.5 as compared with 18.4% or 1 in 5.4 of NCBH at risk pregnancies (P less than .05). Indirect Coombs' tests in cord sera, representing the passive transfer from mother to fetus of antibodies directed toward antigens on the infants' erythrocytes, were positive in 58.8% of UPRH at risk infants as opposed to 40.4% of NCBH at risk infants (P less than .001). Maternal isohemagglutinin titers at term were higher in type O UPRH mothers than in type O NCBH mothers (P less than .01). A relationship between helminth parasitic infection of the mother and ABO HD in the infant was suspected but not proved.

ABO Blood-Group System↗

PubMed1978

Suppression of rejection of Nippostrongylus brasiliensis in iron and protein deficient rats: effect of syngeneic lymphocyte transfer.

Rejection of Nippostrongylus brasiliensis is impaired in iron and protein deficient rats and this suggests that iron and protein deficiency directly or indirectly suppresses the immune response. The site of the immunological defect in deficient rats was investigated using the technique of cellular transfer of resistance. The functional activity of immune mesenteric lymph node cells obtained from iron and protein deficient donors was not depressed as measured by their capacity to cause parasite rejection in nutritionally sufficient recipients. In contrast, immune lymph node cells obtained from either sufficient or deficient donors did not result in parasite rejection in iron and protein deficient recipients. These results indicate that there is no permanent defect of lymphocyte function in iron and protein deficient rats and suggest that either some other component of the rejection mechanism is defective, or that lymphocyte function is blocked in an iron and protein deficient environment.

Animals↗