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Biomedical subjects

E R Burns

Publications and source records attributed to E R Burns.

At least 19 recordsLinked to original sources
PubMed1994

The temporal relationships of synthesis and phosphorylation in stress proteins 70 and 90 in aged caloric restricted rats exposed to bleomycin.

A single intraperitoneal injection of the human therapeutic drug bleomycin (BL) was administered to three groups of male Fischer 344 rats at time 0, and the incorporation of [35S]methionine ("synthesis") and phosphorylation patterns of stress proteins (sps/hsps) from bone marrow cells were analyzed over time by two-dimensional electrophoresis and fluorography. Two groups of rats, young ad libitum (Y/AL--3 months) and old ad libitum (O/AL--28 months), had free access to rat chow, and a third group of old rats (O/CR--28 months) were maintained on a caloric restricted intake (60% of the AL diet). The administration of BL in Y/AL, O/AL and O/CR animals activated the 35S-labeling of sp 90 which reached a peak at 4 hours. Labeling of sp 90 was significantly greater in Y/AL compared to O/AL, and the incorporation pattern of O/CR was intermediate to Y/AL and O/AL animals. All labeling of sp 90 in each group had disappeared by 10 hours after BL administration. Stress protein 70x (inducible form) in these three animal groups displayed a similar pattern of 35S-incorporation, but the amount of labeling was less than that of sp 90. No labeling of sp 70x remained by 13 hours after BL administration. Phosphorylation ([32P] phosphate incorporation) of sp 90 reached a maximum level at 2 hours in all animals, and 32P-labeling in Y/AL was significantly increased over O/AL and O/CR with an intermediate level found in O/CR animals. The turnover rate (phosphorylation/dephosphorylation) of sp 90 induced by BL was significantly suppressed and temporarily extended in O/AL as compared with O/CR, which implied that CR not only increased incorporation of sp 90, but also enhanced a utilization of the phosphate pool very similar to that seen in Y/AL animals.

Aging↗
PubMed1992

A nuclear protein associated with lethal heat shock of HL-60 cells.

The responses to stress in living cells are well known. Thermal stress causes decreased protein synthesis as well as rapid induction of heat shock proteins (hsps), or alternately termed stress proteins (sps). The exposure of cultured promyelocytic leukemia cells (HL-60) to a 45 degrees C lethal heat shock for 1 h elicited synthesis and phosphorylation of a polypeptide M(r) 48,000 and pI 7.5 (p 48) as visualized by two-dimensional polyacrylamide gel ultra-microelectrophoresis. p 48, which was not observed at sublethal temperatures (39 and 41 degrees C), was synthesized during all phases of the cell cycle but was phosphorylated only in G0 + G1 and S-phases. The appearance of p 48 was marked by a concomitant and reciprocal reduction in hsps or sps 70 and 90. Distinct protease V8 fragment maps of p 48, hsps 70 and 90 in conjunction with immunochemical determination indicated vast differences in their primary structures. These facts suggest that p 48 was not formed from coalesced breakdown products of hsps 70 or 90. Western blotting showed that p 48 possessed the same immunochemical determinants as two other proteins with the same molecular mass but different isoelectric points. In an association assay, p 48 was shown to bind with actins and hsp 90 from HL-60 nuclei.

Cell Cycle↗
PubMed1992

Preoperative laboratory assessment of hemostasis for orthognathic surgery.

Platelet count, prothrombin time, and activated partial thromboplastin time provide a baseline to evaluate patients with known coagulopathy, as well as present an opportunity to diagnose disease in previously symptom free patients. Current hematologic management of patients with Von Willebrand's disease uses heated Factor VIII that allows patients to undergo orthognathic surgery without significant risk of disease transmission from banked blood products.

Adult↗
PubMed1992

Prevention of growth of Yersinia enterocolitica in blood by polyester fiber filtration.

The ability of polyester white cell-reduction blood filters to prevent the growth of Yersinia enterocolitica in units of donated blood was studied. Sixteen units of freshly drawn blood were inoculated with 10, 50, 100, or 150 colony-forming units (CFU) per mL of a clinical isolate of Y. enterocolitica (serotype O:3). The units were subsequently fractionated into red cell concentrate and resuspended in AS-1 or AS-3 solution. One-half of the red cell concentrates in each solution were filtered within 15 hours of phlebotomy and stored for 42 days. The remaining units served as unfiltered controls. Bacterial growth was monitored by weekly cultures and, on the last storage day, by the presence of endotoxin and the formation of methemoglobin. One hundred twelve primary cultures (560 plates) were performed. Units collected in AS-1 and filtered remained sterile when initially inoculated with 50 CFU or less. Filtered units spiked with 100 CFU or less and collected in AS-3 remained sterile throughout their shelf life. All unfiltered units supported bacterial growth and the formation of endotoxin and methemoglobin. The filtration of freshly donated blood proves to limit the growth of Y. enterocolitica in red cell components.

Blood Gas Analysis↗
PubMed1992

The high mobility group of nuclear proteins as biomarkers of age and caloric restriction in rats.

The quantitative levels and phosphorylation states of the high mobility group (HMG) of proteins were investigated in bone marrow, brain, heart, kidney, liver, pancreas, spleen, testis and thymus of three groups of male Fischer 344 rats. Two groups of rats, young ad libitum (Y/AL - 1 1/2 mo.) and old ad libitum (O/AL - 28 mo.), had free access to rat chow, and a third group of old rats were maintained on a caloric restricted intake (O/CR - 28 mo.). The quantities of HMGs 1,2,14 and 17 were significantly reduced in O/AL rats compared with Y/AL rats in all tissues examined, and in many cases, the amount of HMGs of O/CR rats were increased by varying degrees from O/AL animals. In G2-phase nuclei of bone marrow, spleen and testis, phosphorylation of HMG proteins was reduced significantly in O/AL rats, but was enhanced in O/CR animals (especially HMG14). These levels of HMGs in O/CR animals, altered by age and diet dependent factors, reflect a condition which is more reminiscent of Y/AL than O/AL animals.

Aging↗
PubMed1991

Treatment of septic thrombocytopenia with immune globulin.

Thrombocytopenia frequently complicates systemic infection and results from multiple possible mechanisms. We and others have demonstrated that platelet-associated IgG (PAIgG) levels are elevated in the majority of patients with septic thrombocytopenia. Corticosteroids may be undesirable as a treatment for thrombocytopenia for patients with severe infection because of their potential for suppressing the immune response. We hypothesized that septic thrombocytopenia is, in most cases, an immune disorder analogous to idiopathic thrombocytopenic purpura (ITP) which might respond to intravenous gamma-globulin as a treatment for increasing the platelet count in this disorder. Intravenous immune globulin (IVIG), 400 mg/kg daily for 3 days, was administered in a randomized double-blind placebo-controlled trial. Twenty-nine patients who developed thrombocytopenia during a documented, septic episode were studied. Patients with disseminated intravascular coagulation (DIC), hypersplenism, or drugs known to cause thrombocytopenia were excluded. Elevated PAIgG levels were documented in 52% of evaluable patients. Mean platelet counts in the IVIG group rose from 43K at study entry to 178K (411% rise) by Day 9. In the placebo group platelets rose from 51K to 125K (261% rise; P = 0.02). Seventy-seven percent of the IVIG group had a minimum peak rise of 35K, vs 56% of the placebo group. Three patients in the placebo group had a serious bleeding episode, vs one in the IVIG group. The use of IVIG to treat septic thrombocytopenia not associated with DIC leads to a more rapid, more sustained, and greater increase in platelet count than placebo. Its use is recommended in the septic patient who is bleeding or is likely to need invasive or surgical procedures.

Blood Platelets↗
PubMed1991

Synergistic effects of endothelin-1 (ET-1) and transforming growth factor alpha (TGF-alpha) or epidermal growth factor (EGF) on DNA replication and G1 to S phase transition.

The cooperative cell kinetic actions of ET-1 with TGF-alpha or EGF in normal rat kidney fibroblasts (NRK-49F) and KNRK cells (Kirsten MSV transformed) were analyzed by [3H]-thymidine incorporation assay and flow cytometry. A marked synergistic effect of TGF-alpha and ET-1 (or EGF and ET-1) on DNA synthesis and G1 to S transition was observed in NRK cells; 15-20% S for TGF-alpha and 12% S for ET-1 alone but 45-50% S in combination. There was no detectable effect on cell cycle kinetics by TGF-alpha (1 ng/ml) or EGF (1 ng/ml) plus ET-1 (1 ng/ml) in KNRK cells treated for 22 hours. Insulin, insulin-like growth factor I (IGF-I), fibroblast growth factor (FGF), platelet derived growth factor (PDGF), and transforming growth factor beta (TGF-beta) were also tested and found to have no significant synergistic effects on ET-1 actions. Our findings suggest that the combination of TGF-alpha (EGF) and ET-1 is an important part of an intricate network which coordinates progression of G1 to S phase in normal cells.

Animals↗
PubMed1991

A rare-event analysis model for quantifying white cells in white cell-depleted blood.

An analysis model to detect and quantify white cells (WBCs) in red cell concentrates (RBCC) drawn from units of blood that are highly depleted of WBCs is described. WBC detection is performed by fluorescence analysis of 50 microL of RBCC labeled with propidium iodide, a DNA/RNA fluorophore. Quantification is performed by regression analysis of standard dilutions of RBCC in substantially WBC-free red cells. This RBCC diluent is obtained by filtration of blood through a new medium. The method proves to be precise (CV = 7%), efficient (+/- 30 min/aliquot), and linear (r = 0.99) to 6 log10 WBC depletion of the native product. The current technique is preferable to those suggested previously, such as ficoll concentration, which requires the sacrifice of the unit of blood for counting purposes, and to earlier fluorescence analysis techniques that do not employ WBC-free red cell diluents. The latter do not monitor extremely low concentrations of WBCs because they lack adequate signal-to-noise discrimination. The sensitivity of the described method allows for monitoring of WBC depletion procedures with greater efficiency than is currently available commercially.

Blood Component Removal↗
PubMed1991

Improvement in transfusion safety using a new blood unit and patient identification system as part of safe transfusion practice.

A new patient and blood unit identification system designed to confirm the identity of crossmatched blood products and that of the intended recipient was evaluated. Six hundred seventy-two red cell concentrates were transfused to 312 patients. Participating hospital personnel and patients were interviewed regarding the use and benefit of this unique system, which incorporates a "lock-box" approach to the identification process. The product and procedure were accepted unanimously and enthusiastically, and three potential mistransfusions were avoided by use of the system during the limited period of observation. This type of approach to the identification process affords greater security than conventional practices and minimally burdens staff.

Blood Transfusion↗
PubMed1991

Rapid removal of heparin from plasma by affinity filtration.

Coagulation test abnormalities caused by the presence of heparin are not uncommon and frequently result in additional laboratory investigation and unwarranted therapy. Methods to neutralize the effect of heparin include the addition of polyanions, enzymes, or resins to the clinical samples. These techniques are time consuming and cumbersome and produce inconsistent results. As an alternative, use of a positively charged porous filtration medium to remove heparin from the sample is described. The filtration procedure requires less than one minute and provides a consistent and total removal of heparin at plasma concentrations in excess of therapeutic levels. Chromogenic substrate analysis for residual heparin activity confirms total removal of the drug at levels greater than one unit/mL of plasma. In clinical trials, filtration normalized the activated partial thromboplastin time (APTT) of all patient specimens containing heparin (n = 41). Filtration did not shorten the coagulation assay times of patients receiving warfarin (n = 36) or of those with a variety of acquired coagulopathies (n = 14). The level of coagulation factors adsorbed to the filter medium compares favorably to that adsorbed by other commercially available heparin-binding resins. Routine use of the filter in the clinical laboratory allows for the rapid and definitive identification of heparin in specimens with prolonged coagulation times and provides clinically meaningful data.

Blood Coagulation Factors↗
PubMed1991

Platelet studies in the pathogenesis of thrombocytopenia in May-Hegglin anomaly.

Thrombocytopenia has a variable incidence in the May-Hegglin anomaly, a rare congenital syndrome characterized by inclusions resembling Dohle bodies within leukocytes, thrombocytopenia, and giant platelets. We studied a 16-year-old girl and three relatives with the syndrome to elucidate the pathogenesis of the thrombocytopenia and the degree of impaired hemostasis. On confirmation of automated platelet counts by manual techniques we found that both aperture-impedence and light-scatter instruments tended to undercount the actual number of platelets by 30-50%. An enzyme immunoassay for platelet-associated IgG showed elevated levels in all patients (mean of 2.3 +/- 0.6 ng/10(6) platelets versus 0.8 +/- 0.6 in normals, p less than 0.0001). Bleeding time and platelet aggregation in response to adenosine diphosphate, arachidonic acid, epinephrine, ristocetin, and collagen were all normal. No clinical bleeding was observed in any of the patients in the face of major surgery or childbirth. The findings suggest the possibility of a peripheral destructive and perhaps an immune pathogenesis of the thrombocytopenia of May-Hegglin anomaly and confirm that clinical bleeding may not accompany the severe thrombocytopenia seen in this disorder.

Adolescent↗
PubMed1991

Nuclear protein phosphorylation in rat cerebral cells following acute exposure to ethanol.

The sequelae of acute ethanol toxicity encompass a broad spectrum of metabolic and cellular derangements, including the induction of stress proteins in cells exposed to high levels of ethanol. In this investigation, the effects of ethanol exposure on nuclear protein synthesis and phosphorylation were compared by two-dimensional gel electrophoresis in glial-enriched cultures, adult rat cerebrum and regenerated liver. Cellular exposure to ethanol was at clinically relevant levels and tissue was analyzed at 1 h and 48 h after exposure. Cell nuclei were stained with propidium iodide, a DNA specific fluorochrome and flow cytometrically sorted to obtain cell cycle phase populations of nuclei for analysis. Ethanol treatment of intact rats and glial-enriched cultures induced phosphorylation of specific nuclear proteins, which were detected by two-dimensional electrophoresis and autoradiography. The autoradiographs of [32P]phosphate and [3H]leucine labeled proteins from glial-enriched cultures and from the G0/G1 phase of the regenerating liver tissue exhibited intense labeling indicative of active protein synthesis and phosphorylation. In contrast, the autoradiographs of proteins from adult rat cerebra showed substantial phosphorylation, but weak protein synthesis. Ethanol treatment was associated with phosphorylation of a 50,000 Mr protein in G0/G1 phase cells of the cultures and in predominantly G0 cells of the adult rat cerebra. A protein with similar characteristics was not found in ethanol exposed regenerating rat liver tissue and has not been observed in other 'heat shock' or 'stress' protein systems which we have previously studied.

Animals↗
PubMed1991

Synthesis and phosphorylation of nuclear matrix proteins following a toxic dose of retinoic acid in cycling and differentiating HL-60 cells.

Exposure of HL-60 cells to 2 microM retinoic acid, twice the dose necessary for differentiation, initiated protein synthesis within 2 h exposure in the nuclear matrix proteins and phosphorylation of a subfraction of these proteins, designated the phenol-soluble nuclear proteins. These processes were examined by fluorography of two-dimensional polyacrylamide gels. Three cell-cycle related stress proteins (22, 70c, 70x Mr x 10(-3)), were seen in the nuclear matrix fraction that were synthesized early and disappeared rapidly following dosing with retinoic acid. In control cells, protein 120 was also cell-cycle related and showed modest synthesis in nuclear matrix and strong phosphorylation in phenol-soluble fraction. Within 5 h after dosing, p120 exhibited alteration in phosphorylation as evidenced by mapping of [32P]-labeled peptides. Two nuclear matrix proteins, p52 and p55, incorporated [3H] retinoic acid rapidly, were cell-cycle-related, and disappeared within 12 h of dosing. Progressive increases in the labeling of the nuclear matrix and phenol-soluble nuclear proteins with increasing retinoic acid exposure was apparent in G2-phase at 96 h time-after-dosing.

Antigens, Nuclear↗
PubMed1991

Synthesis and biochemical characteristics of nucleoproteins following a toxic dose of retinoic acid in cycling and differentiating HL-60 cells.

Exposure of HL-60 cells to 2 microM retinoic acid (RA), twice the dose necessary for differentiation, initiated rapid synthesis (2 h) of the nuclear stress proteins (SPs) e.g., 90, 70c, 70x, 22 (Mr x 10(-3)) during the G0 + G1 phase of the cell cycle as observed by polyacrylamide gel electrophoresis (PAGE). Synthesis of SPs was cell cycle correlated and not dependent on time-after-dosing, and all labeling disappeared from these proteins within 48 h of RA exposure. Stress proteins were not elicited with a 1 microM dose or less of retinoic acid. Non-stress nuclear proteins revealed changes in synthesis levels (e.g., actin, lamins, tubulins) which were cell cycle related and temporally associated with dosing. A major non-stress nuclear protein (Mr 120,000) which possessed an affinity for actin in binding assays, was cell cycle related in control cells, and was suppressed in synthesis in cells exposed to 2 microM retinoic acid. Two additional nuclear non-SPs 51 and 55 (Mr x 10(-3)) covalently bound the isotope [3H]retinoic acid, and their incorporation was cell cycle correlated during early periods of RA exposure. Except for the induction of SPs, the autoradiographs of nuclear proteins of RA dosed HL-60 cells, showed more quantitative than qualitative changes.

Actins↗
PubMed1990

Flow cytometric DNA analysis of corneal epithelium.

We have modified an existing technique in order to perform DNA analysis by flow cytometry (FCM) of corneal epithelium from the mouse, rat, chicken, rabbit, and human. This protocol permitted an investigation of human corneal scrapings from several categories: normal, aphakic bullous keratopathy (ABK), keratoconus (KC), Fuch's dystrophy, edema, epithelial dysplasia, and lipid degeneration. No abnormal characteristic cell-kinetic profile was detected when averaged DNA histograms were compared statistically between the normal and either ABK, KC, edema, or Fuch's dystrophy groups. Abnormal DNA histograms were recorded for cell samples that were taken 1) from three individuals who had epithelial dysplasia and 2) from one individual diagnosed with lipid degeneration. The former condition was characterized by histograms that had a subpopulation of cells with an aneuploid amount of DNA or had higher than normal percentages of cells in the S and G2 + M phases of the cell cycle. Corneal cells from the patient who had lipid degeneration had an abnormally high percentage of cells in the G2 + M phases of the cell cycle. The availability of accurate DNA flow cytometric analysis of corneal epithelium allows further studies on this issue from both experimental and clinical situations.

Animals↗
PubMed1990

Clinical utility of serum tests for iron deficiency in hospitalized patients.

Serum iron and ferritin measurements lack the requisite sensitivity and/or specificity to accurately diagnose iron deficiency. To determine their utility in hospitalized patients, the authors compared the results of these tests with the presence of stainable iron in bone marrow aspirates of 301 patients. Forty (13.3%) had absent marrow iron. The serum diagnosis of iron deficiency was accepted on the basis of the following: iron less than 11 mumol/L, total iron-binding capacity (TIBC) greater than 45 mumol/L, transferrin saturation (%Sat) less than 0.20, and ferritin less than 13 micrograms/L for females and less than 25 micrograms/L for males. Using these criteria, iron deficiency was correctly diagnosed by serum iron in 41%, TIBC in 84%, %Sat in 50%, and ferritin in 90% of the patients. The serum ferritin is clearly the only useful serum test for diagnosing iron deficiency in hospitalized patients but is limited by a low sensitivity. The bone marrow examination is the most sensitive test for diagnosing iron deficiency in hospitalized patients.

Anemia, Hypochromic↗
PubMed1990

Hematologic manifestations in pediatric HIV infection: severe anemia as a prognostic factor.

The hematologic profile of 100 symptomatic children infected by the human immunodeficiency virus (HIV) was evaluated and compared to HIV uninfected infants with transplacentally acquired maternal anti-HIV antibodies, and to HIV-negative infants born to i.v. drug-abusing HIV uninfected mothers. Anemia was present in 94% of HIV-infected infants and was a major predictor of disease progression. In 91% of patients having a hematocrit (HcT) less than 25%, the disease course was rapidly fatal. Leukopenia and thrombocytopenia occurred in 47 and 33% of HIV infected patients, respectively. Neutropenia was most severe in children with opportunistic infections. There was no evidence of suppression of any component of hematopoiesis by passively acquired antibodies to HIV.

Anemia↗