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PubMed1997

Secondary insults during the interhospital transfer of head-injured patients: an audit of transfers in the Mersey Region.

To assess the incidence of secondary insults and unidentified extracranial injuries a prospective audit of 50 head-injury transfers to a regional neurosurgical unit using a standardized assessment proforma was undertaken. There was wide variability in the quality of transfers. Six per cent of the group were hypoxic on arrival and 15 per cent were hypotensive. In the patients with multiple injuries, 29 per cent had inadequately diagnosed or managed injuries when they arrived. A comparison of this cohort of patients with previous studies is presented. As a result of the audit a set of transfer and referral guidelines have been drawn up and, following distribution of the guidelines to our referring hospitals, a further cohort of patients will be audited.

Adolescent↗

PubMed2001

Analysis of gene transfer efficiency of retrovirus producer cell transplantation for in situ gene transfer to hematopoietic cells.

OBJECTIVE: The aim of this study was to assess the gene transfer efficiency of an in situ administration protocol for hematopoietic stem/progenitor cells in the rhesus macaque (Macaca mulatta) animal model. MATERIALS AND METHODS: Moloney murine leukemia virus amphotropic vector producer cells (1--2 x 10(8) cells/animal) were transplanted into the femoral bone marrow cavities of six macaques. To determine if the levels of gene transfer could be increased, a second injection at the same dose of producer cells was performed into the iliac crest in three of the six macaques. RESULTS: We demonstrated that 0.02-0.1% of peripheral blood mononuclear cells contained the vector transgene for up to 12 months following the initial administration of producer cells. Hematopoietic progenitor cell assays indicated that the neomycin phosphotransferase gene was detected in 10--30% of progenitor cell colonies. A humoral immune response directed toward viral particles was demonstrated in all animals. Additionally, we demonstrated that an increase in the levels of transduced cells, up to 1% of circulating peripheral blood mononuclear cells and granulocytes, contain the transgene following producer cell readministration. CONCLUSIONS: These data demonstrate the successful in situ gene transfer to hematopoietic stem/progenitor cells and circulating peripheral blood mononuclear cells that persists as long as 12 months postinjection, in the absence of any preconditioning.

Animals↗

PubMed1998

The implications of the structure of the bactericidal/permeability-increasing protein on the lipid-transfer function of the cholesteryl ester transfer protein.

The cholesteryl ester transfer protein (CETP) is evolutionarily related to the bactericidal/permeability-increasing protein (BPI). The recently solved structure of BPI shows an elongated, boomerang-shaped molecule, with two hydrophobic pockets opening to its concave side. These pockets each contain a phospholipid molecule. A model of CETP, based on the recently solved crystal structure of BPI, provides the basis for interpreting functional studies on CETP. In this model, C-terminal residues 461-476, which were shown to be required for neutral lipid transfer between plasma lipoproteins, from an amphipathic helix covering the opening of the N-terminal pocket. A possible lipid-transfer mechanism for CETP, with the initial step involving the disordering of lipids in the lipoprotein surface, followed by the flipping and entry of a lipid molecule into the hydrophobic lipid-binding pocket, is hypothesized in light of structural evidence and recent studies.

Antimicrobial Cationic Peptides↗

PubMed2001

The rate of lipid transfer during fusion depends on the structure of fluorescent lipid probes: a new chain-labeled lipid transfer probe pair.

A number of fluorescent probes have been used to follow membrane fusion events, particularly intermixing of lipids. None of them is ideal. The most popular pair of probes is NBD-PE and Rh-PE, in which the fluorescent groups are attached to the lipid headgroups, making them sensitive to changes in the surrounding medium. Here we present a new assay for monitoring lipid transfer during membrane fusion using the acyl chain tagged fluorescent probes BODIPY500-PC and BODIPY530-PE. Like the NBD-PE/Rh-PE assay, this assay is based on fluorescence resonance energy transfer (FRET) between the donor, BODIPY500, and the acceptor, BODIPY530. The magnitude of FRET is sensitive to the probe surface concentration, allowing one to detect movement of probes from labeled to unlabeled vesicles during fusion. The high quantum yield of fluorescence, high efficiency of FRET (R(o) is estimated to be approximately 60 A), photostability, and localization in the central hydrophobic region of a bilayer all make this pair of probes quite promising for detecting fusion. We have compared this and two other lipid mixing assays for their abilities to detect the initial events of poly(ethylene glycol) (PEG)-mediated fusion of small unilamellar vesicles (SUVs). We found that the BODIPY500/530 assay showed lipid transfer rates consistent with those obtained using the DPHpPC self-quenching assay, while lipid mixing rates measured with the NBD-PE/Rh-PE RET assay were significantly slower. We speculate that the bulky labeled headgroups of NBD-PE and especially Rh-PE molecules hamper movement of probes through the stalk between fusing vesicles, and thus reduce the apparent rate of lipid mixing.

Boron Compounds↗

PubMed1987

Reactions of electron-transfer flavoprotein and electron-transfer flavoprotein: ubiquinone oxidoreductase.

Electron-transfer flavoprotein:ubiquinone oxidoreductase (ETF-Q oxidoreductase) catalyses the re-oxidation of reduced electron-transfer flavoprotein (ETF) with ubiquinone-1 (Q-1) as the electron acceptor. A kinetic assay for the enzyme was devised in which glutaryl-CoA in the presence of glutaryl-CoA dehydrogenase was used to reduce ETFox. and the reduction of Q-1 was monitored at 275 nm. The partial reactions involved in the overall assay system were examined. Glutaryl-CoA dehydrogenase catalyses the rapid reduction of ETFox. to the anionic semiquinone (ETF.-), but reduces ETF.- to the fully reduced form (ETFhq) at a rate that is about 6-fold lower. ETF.-, but not ETFhq, is directly re-oxidized by Q-1 at a rate that, depending on the steady-state concentration of ETF.-, may contribute significantly to the overall reaction. ETF-Q oxidoreductase catalyses rapid disproportionation of ETF.- with an equilibrium constant of about 1.0 at pH 7.8. In the presence of Q-1 it also catalyses the re-oxidation of ETFhq at a rate that is faster than that of the overall reaction. Rapid-scan experiments indicated the formation of ETF.-, but its fractional concentration in the early stages of the re-oxidation of ETFhq is low. The data indicate that the re-oxidation of ETFhq proceeds at a rate that is adequate to account for the overall rate of electron transfer from glutaryl-CoA to Q-1. An unusual property of ETF-Q oxidoreductase seems to be that it not only catalyses the re-oxidation of the reduced forms of ETF but also facilitates the complete reduction of ETFox. to ETFhq by disproportionation of the radical.

Catalysis↗

PubMedDate not supplied

Transferring dying nursing home residents to the hospital: DON perspectives on the nurse's role in transfer decisions.

This qualitative study elicits factors that influence decision-making by nurses about transferring a dying resident from the nursing home to the hospital. Focus groups with directors of nursing (DONs) from long-term care facilities revealed those decisions are influenced by knowledge (or lack thereof) of resident or family preferences, nurse interactions with physicians, nursing home technological and personnel resources, and nurse concerns about institutional liability. DONs can improve transfer decisions by communicating with all parties, clarifying nursing home processes for end-of-life care, and scheduling early and thorough conversations with residents and families about end-of-life care. DONs can implement improvements through staff education on communication issues, rigorous evaluation and performance outcome measures related to patient transfer, and conveyance to staff of the institution's mission and the nursing service's values.

Decision Making↗

PubMed2006

Structure of electron transfer flavoprotein-ubiquinone oxidoreductase and electron transfer to the mitochondrial ubiquinone pool.

Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a 4Fe4S flavoprotein located in the inner mitochondrial membrane. It catalyzes ubiquinone (UQ) reduction by ETF, linking oxidation of fatty acids and some amino acids to the mitochondrial respiratory chain. Deficiencies in ETF or ETF-QO result in multiple acyl-CoA dehydrogenase deficiency, a human metabolic disease. Crystal structures of ETF-QO with and without bound UQ were determined, and they are essentially identical. The molecule forms a single structural domain. Three functional regions bind FAD, the 4Fe4S cluster, and UQ and are closely packed and share structural elements, resulting in no discrete structural domains. The UQ-binding pocket consists mainly of hydrophobic residues, and UQ binding differs from that of other UQ-binding proteins. ETF-QO is a monotopic integral membrane protein. The putative membrane-binding surface contains an alpha-helix and a beta-hairpin, forming a hydrophobic plateau. The UQ-flavin distance (8.5 A) is shorter than the UQ-cluster distance (18.8 A), and the very similar redox potentials of FAD and the cluster strongly suggest that the flavin, not the cluster, transfers electrons to UQ. Two possible electron transfer paths can be envisioned. First, electrons from the ETF flavin semiquinone may enter the ETF-QO flavin one by one, followed by rapid equilibration with the cluster. Alternatively, electrons may enter via the cluster, followed by equilibration between centers. In both cases, when ETF-QO is reduced to a two-electron reduced state (one electron at each redox center), the enzyme is primed to reduce UQ to ubiquinol via FAD.

Animals↗

PubMed2003

Adoptive transfer of apoptotic splenocytes worsens survival, whereas adoptive transfer of necrotic splenocytes improves survival in sepsis.

In sepsis, both necrotic and apoptotic cell death can occur. Apoptotic cells induce anergy that could impair the host response, whereas necrotic cells cause immune activation that might result in enhanced antimicrobial defenses. We determined whether adoptive transfer of apoptotic or necrotic cells impacted survival in a clinically relevant sepsis model. We also evaluated the effects of adoptive transfer of apoptotic or necrotic cells on the prototypical TH1 and TH2 cytokines IFN-gamma and IL-4, respectively. C57BL6/J mice had adoptive transfer of apoptotic (irradiated) or necrotic (freeze thaw) splenocytes. Controls received saline. Apoptotic cells greatly increased mortality, whereas necrotic splenocytes markedly improved survival, P < or = 0.05. The contrasting effects that apoptotic or necrotic cells exerted on survival were mirrored by opposite effects on splenocyte IFN-gamma production with greatly decreased and increased production, respectively. Importantly, either administration of anti-IFN-gamma antibodies or use of IFN-gamma knockout mice prevented the survival benefit occurring with necrotic cells. This study demonstrates that the type of cell death impacts survival in a clinically relevant model and identifies a mechanism for the immune suppression that is a hallmark of sepsis. Necrotic cells (and likely apoptotic cells) exert their effects via modulation of IFN-gamma

Adoptive Transfer↗

PubMed1971

Base composition differences between avian myeloblastosis virus transfer RNA and transfer RNA isolated from host cells.

Using a novel chemical tritium derivative method, we have determined the base composition of 4S RNA isolated from an RNA tumor virus, the avian myeloblastosis virus, and from normal and neoplastic host cells. Extensive differences were detected, particularly with respect to the amount of methylated bases in the viral RNA. The viral 4S RNA, which fulfills the criteria for designation as transfer RNA, appears to be derived from a precursor pool that is different from the precursor population of host-cell 4S RNA. These results are discussed in regard to the possible relationship between transfer RNA of avian mycoblastosis virus and cellular transfer RNA.

Animals↗

PubMed1992

Synthesis and secretion of wild-type and mutant human plasma cholesteryl ester transfer protein in baculovirus-transfected insect cells: the carboxyl-terminal region is required for both lipoprotein binding and catalysis of transfer.

Functional plasma cholesteryl ester transfer protein (CETP; 476 amino acids) has been expressed in baculovirus-transfected Sf9 insect cells by using a full-length cDNA derived from a human placental library. The product bound to each major plasma lipoprotein class, and it catalyzed the transfer of both cholesteryl esters and triglyceride. CETP species with overlapping deletions were generated in the carboxyl-terminal region. These mutants were defective in cholesteryl ester and triglyceride transfer. Structural and functional analysis suggests that normal lipoprotein binding and effective catalysis may require the carboxyl-terminal sequence -Phe-Leu-Leu-Leu- (residues 454-457), possibly with the involvement of other sequences in the carboxyl-terminal region. A similar sequence is contained in several other proteins whose functions involve binding nonpolar lipids, including lecithin: cholesterol acyltransferase, lipopolysaccharide-binding protein, bactericidal permeability-increasing protein, cholesterol 7 alpha-hydroxylase, cholesterol esterase, and hormone-sensitive lipase. These data suggest that a conserved neutral lipid-binding sequence may be one important factor in the activity of CETP and possibly in several other proteins of plasma and cellular lipid metabolism.

Amino Acid Sequence↗

PubMed1994

Luminescence energy transfer using a terbium chelate: improvements on fluorescence energy transfer.

We extend the technique of fluorescence resonance energy transfer (FRET) by introducing a luminescent terbium chelate as a donor and an organic dye, tetramethylrhodamine, as an acceptor. The results are consistent with a Förster theory of energy transfer, provided the appropriate parameters are used. The use of lanthanide donors, in general, and this pair, in particular, has many advantages over more conventional FRET pairs, which rely solely on organic dyes. The distance at which 50% energy transfer occurs is large, 65 A; the donor lifetime is a single exponential and long (millisecond), making lifetime measurements facile and accurate. Uncertainty in the orientation factor, which creates uncertainty in measured distances, is minimized by the donor's multiple electronic transitions and long lifetime. The sensitized emission of the acceptor can be measured with little or no interfering background, yielding a > 25-fold improvements in the signal-to-background ratio over standard donor-acceptor pairs. These improvements are expected to make distances > 100 A measurable via FRET. We also report measurement of the sensitized emission lifetime, a measurement that is completely insensitive to total concentration and incomplete labeling.

Base Sequence↗

PubMed2005

Sit to stand transfer: performance in rising power, transfer time and sway by age and sex in senior athletes.

OBJECTIVE: To observe the differences in performance variables of the sit to stand transfer (as measured on the NeuroCom Balance Master) in a population of senior athletes. METHOD: A convenience sample of 173 subjects aged 50 years and older. Data were obtained from voluntary participation in a health fair offered at the annual Huntsman World Senior Games in St George, Utah, USA. All sit to stand tests were performed on the NeuroCom Balance Master. The measured parameters were weight transfer time (WTT), rising power (force exerted to rise), and centre of gravity sway (COG sway) during the rising phase. RESULTS: A significant difference was found between stratified age groups (50-64 and 65+ years) on rising power. There was also a sex difference in rising power. No significant differences were found in weight transfer time or COG sway. CONCLUSION: While rising power decreases with increasing age in senior athletes, WTT and COG sway remain similar regardless of age or sex. The maintenance of these other two variables (WTT and COG sway) may be attributable to physical activity and/or participation in sport.

Age Factors↗

PubMed2006

Plasma phospholipid transfer protein fused with green fluorescent protein is secreted by HepG2 cells and displays phosphatidylcholine transfer activity.

Phospholipid transfer protein (PLTP) is a serum glycoprotein with a central role in high-density lipoprotein metabolism. We created a fusion protein in which enhanced green fluorescent protein (EGFP) was fused to the carboxyl-terminus of PLTP. Stably transfected HepG2 cells, which overexpress this fusion protein, were generated. PLTP-EGFP was translocated into the ER and fluoresced within the biosynthetic pathway, showing a marked concentration in the Golgi complex. The transfected cells secreted into the growth medium phospholipid transfer activity 7-fold higher than that of the mock-transfected controls. The medium of the PLTP-EGFP - expressing cells displayed EGFP fluorescence, demonstrating that both the PLTP and the EGFP moieties had attained a biologically active conformation. However, the specific activity of PLTP-EGFP in the medium was markedly reduced as compared with that of endogenous PLTP. This suggests that the EGFP attached to the carboxyl-terminal tail of PLTP interferes with the interaction of PLTP with its substrates or with the lipid transfer process itself. Fluorescently tagged PLTP is a useful tool for elucidating the intracellular functions of PLTP and the interaction of exogenously added PLTP with cells, and will provide a means of monitoring the distribution of exogenously added PLTP between serum lipoprotein subspecies.

Cell Line↗

PubMed1984

Adoptive transfer of delayed hypersensitivity and protective immunity to Eimeria tenella with chicken-derived transfer factor.

Delayed hypersensitivity (DH) and protective immunity were transferred to nonimmune 4- and 10-week-old broiler chickens with transfer factor (TF) prepared from splenic leukocytes of chickens immunized with CocciVac D. Only chickens injected with the immune TF showed DH by wattle reaction to oocyst antigen and protective immunity to Eimeria tenella challenge infection. Chickens given a single injection of TF 5 days before challenge infection exhibited a significant (P less than .05) DH response at the time of infection. Immune TF preparations were active at concentrations of 100, 200, or 400 mg. Neither DH nor protective immunity was transferred to chickens injected with the TF-diluent control or nonimmune TF. The nonimmune TF was prepared from chickens kept free of coccidial infection. These findings indicated that TF prophylaxis produced beneficial results in nonimmune chickens by conferring some protection against challenge with E. tenella. The effects of TF on T-lymphocyte mediated protective immunity to coccidia in chickens are discussed.

Animals↗

PubMed1989

Distribution and functions of lecithin:cholesterol acyltransferase and cholesteryl ester transfer protein in plasma lipoproteins. Evidence for a functional unit containing these activities together with apolipoproteins A-I and D that catalyzes the esterification and transfer of cell-derived cholesterol.

The distribution of apolipoprotein A-I, apolipoprotein D, lecithin:cholesterol acyltransferase, and cholesteryl ester transfer protein in fasting normal human plasma was determined by two-dimensional electrophoresis followed by immunoblotting. The synthesis and transfer of labeled cholesteryl esters generated in plasma briefly incubated with [3H]cholesterol-labeled fibroblasts was followed in terms of the lipoprotein species containing these antigens. Following the early appearance of labeled free cholesterol in two pre beta-migrating apolipoprotein A-I species (Castro, G. R., and Fielding, C. J. (1988) Biochemistry 27, 25-29), labeled esters were first detected, after a 2-min delay, in a third pre beta-migrating species which also contained apolipoprotein D, lecithin:cholesterol acyltransferase, and cholesteryl ester transfer protein. Pulse-chase experiments determined that label generated in this fraction was the precursor of at least a major part of labeled cholesteryl esters in the bulk of alpha-migrating high density lipoprotein. Over the maximum time course of these experiments (15 min, 37 degrees C), less than 10% of labeled cholesteryl esters were recovered in low or very low density lipoproteins separated by electrophoresis, immunoaffinity, or heparin-agarose chromatography. These data suggest channeling of cell-derived cholesterol and cholesteryl esters derived from it through a preferred pathway involving several minor pre beta-migrating lipoproteins to alpha-migrating high density lipoprotein.

Antibodies, Monoclonal↗

PubMed1989

Early transferences and transference-like reactions.

Some patients manifest intense transferences or transference-like reactions in the earliest hours of psychotherapy. Although these reactions may actually represent transference, they may also arise from other sources, such as aspects of a patient's character, displacements from former therapists, impaired reality testing, information about the therapist, and therapist's behavior. Clinical examples are presented, and their management is discussed.

Anxiety↗

PubMed1987

Human plasma cholesteryl ester transfer protein enhances the transfer of cholesteryl ester from high density lipoproteins into cultured HepG2 cells.

The role of human plasma cholesteryl ester transfer protein (CETP) in the cellular uptake of high density lipoprotein (HDL) cholesteryl ester (CE) was studied in a liver tumor cell line (HepG2). When HepG2 cells were incubated with [3H]cholesteryl ester-labeled HDL3 in the presence of increasing concentrations of CETP there was a progressive increase in cell-associated radioactivity to levels that were 2.8 times control. The CETP-dependent uptake of HDL-CE was found to be saturated by increasing concentrations of both CETP and HDL. The CETP-dependent uptake of CE radioactivity increased continuously during an 18-h incubation. In contrast to the effect on cholesteryl ester, CETP failed to enhance HDL protein cell association or degradation. Enhanced uptake of HDL cholesteryl ester was shown for the d greater than 1.21 g/ml fraction of human plasma, partially purified CETP, and CETP purified to homogeneity, but not for the d greater than 1.21 g/ml fraction of rat plasma which lacks cholesteryl ester transfer activity. HDL cholesteryl ester entering the cell under the influence of CETP was largely degraded to free cholesterol by a process inhibitable by chloroquine. CETP enhanced uptake of HDL [3H]CE in cultured smooth muscle cells and to a lesser extent in fibroblasts but did not significantly influence uptake in endothelial cells or J774 macrophages. These experiments show that, in addition to its known role in enhancing the exchange of CE between lipoproteins, plasma CETP can facilitate the in vitro selective transfer of CE from HDL into certain cells.

Carcinoma, Hepatocellular↗

PubMed1982

Energy transfer as parametric excitation: an examination of nonlinearity in enzymatic reaction, nerve conduction, muscle contraction, electron tunneling, and electron transfer.

Chemical parametric excitation is presented as the fundamental mechanism of energy transfer. Together with the Franck-Condon principle, it provides a mechanically sound explanation for enzymatic reaction, nerve excitation, muscle contraction, and electron transfer at a basic level. Intermediate between macroscopic models of membrane asymmetry and molecular models, the new model rests on a systematic approach, proposed here, to organizational aspects of the energy transfer processes. In support, a derivation is given of the chemical analog of the Manley-Rowe power conservation relations for parametrically excited electrical networks. This extension to chemical systems indicates for the first time an explanation of power flow directionality and delegates a pumping role to the enzyme. The generalized Manley-Rowe relations are suggested to be a universal law of nature. In such case, nonlinearity could be attributable to the coupling of three systems by these generalized Manley-Rowe conditions relating flows/reactions/oscillations--even though separately each system might be described by linear (Onsager) relations.

Animals↗