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Biomedical subjects

B Andersson

Publications and source records attributed to B Andersson.

At least 199 records · Page 11Linked to original sources
PubMed1996

Bronchial brush biopsies for studies of epithelial inflammation in stable asthma and nonobstructive chronic bronchitis.

Recently, bronchial brush biopsy (BBB) has been introduced as a complimentary method to bronchial forceps biopsy for the study of bronchial epithelial cells. We wanted to determine whether epithelial inflammatory cells in bronchial brush biopsies can reflect mucosal inflammation assessed indirectly by levels of cellular activation markers in bronchial lavage fluid. We studied 15 healthy controls, 11 asthmatics with regular steroid inhalation therapy, 13 asthmatics without steroids, and 10 smokers with nonobstructive chronic bronchitis. Differential counts of epithelial and inflammatory cells were made from the BBB material. Bronchial lavage levels of eosinophil cationic protein (ECP), myeloperoxidase (MPO), tryptase, hyaluronan and interleukin-8 (IL-8) were measured as indirect markers for inflammatory cell activation. We found an increased percentage of eosinophil granulocytes in the BBB from the steroid-untreated asthmatic patients (1.16%) in comparison to the other groups (0.11%, 0.09% and 0.02%, respectively; p<0.01). In the steroid-untreated asthmatic patients, the percentage of eosinophils correlated with ECP in bronchial lavage fluid (r=0.73; p<0.01), indicating that the BBB method can reflect the degree of eosinophilic activation. A negative correlation was found for the percentage of eosinophils in BBB with levels of provocative concentration of methacholine causing a 20% fall in forced expiratory volume in one second (PC20) for the asthmatic patients in the study (r= -0.67; p<0.003). The bronchial brush biopsy method appears to give information on the changes present in superficial bronchial epithelium in inflammatory airways disease. These changes appear to relate to the degree of inflammatory activity and disease severity in asthma.

Administration, Inhalation↗
PubMed1996

Impact of preexisting CNS involvement on the outcome of bone marrow transplantation in adult hematologic malignancies.

PURPOSE: To determine the impact of prior or current CNS disease on the outcome of high-dose chemotherapy for patients with hematologic malignancies. PATIENTS AND METHODS: In a 54-month period, 373 patients with hematologic malignancies underwent allogeneic or autologous bone marrow transplantation (BMT) or blood stem-cell transplantation using high-dose thiotepa, busulfan, and cyclophosphamide (TBC) as the preparative regimen. Four patients with active CNS disease at BMT and 20 patients with a history of prior CNS disease were identified. The outcomes of those with a history of CNS disease were compared with those of a matched control group. RESULTS: Of four patients with active CNS disease at the time of BMT, two had CNS recurrences and one recurred in the bone marrow. One patient died of treatment-related toxicity. Four of 20 patients with prior CNS involvement currently remain free of disease. At 2 years, the disease-free survival (DFS) rate was 23% +/- 19%, and the DFS rate for the control group 39% +/- 24% (P = .053). An increased rate of treatment-related toxicity and especially grades II to IV CNS toxicity accounted for the poorer outcome of patients who had a history of CNS disease. Recurrence rates were not significantly different between the two groups. Prior radiation to the CNS correlated with CNS complications posttransplant (p = .01). CONCLUSION: Consolidation with TBC and BMT can induce prolonged DFS in a proportion of patients with a history of CNS disease. Such patients are at increased risk for CNS complications that lead to an inferior overall outcome when compared with a control group.

Adolescent↗
PubMed1996

Assimilation of triglycerides in subcutaneous and intraabdominal adipose tissues in vivo in men: effects of testosterone.

To determine the effects of testosterone (T) on lipid assimilation in different adipose tissue depots, T (250 mg, im) was given to 17 middle-aged men 5 days before abdominal surgery. Twenty-four hours before surgery, 10 microCi labeled oleic acid in 80 g milk fat were administered orally. Lipid radioactivity was measured in adipose tissue biopsies from abdominal ac, omental, and retroperitoneal adipose tissues. Subcutaneous, visceral (omental plus mesenteric), and retroperitoneal adipose tissue masses were determined using computerized tomography scans at 22 levels. Sixteen men who were not treated with T served as controls. T administration was followed by an increase in serum concentrations from 17.7 +/- 1.1 to 32.6 +/- 1.8 nmol/L (P < 0.001) and a marked (> 50%) reduction compared with controls in lipid radioactivity in omental and retroperitoneal adipose tissues, but not in sc adipose tissue. In controls, sc, visceral, and retroperitoneal adipose tissues assimilated 59.2 g (73.4%), 16.9 g (20.9%), and 4.6 g (5.7%), respectively, of the orally administered fat. In the T-treated men, this was changed to 73.5 g (88.8%), 6.4 g (7.7%), and 2.9 g (3.5%), respectively. It was concluded that T inhibits triglyceride assimilation in intra-abdominal depots and apparently directs this lipid to sc fat in men.

Abdomen↗
PubMed1996

Method for 96-well M13 DNA template preparations for large-scale sequencing.

Efficient preparation of DNA templates is an important step in large-scale DNA sequencing. The ensure high-quality sequence data, we have prepared M13 phage DNA templates using a glass fiber-filtration method. We present the adaptation of this protocol to a 96-well format using commercially available filter plates. Two variations are described: one using polyethylene glycol precipitation and a second where the phage particles are disrupted before filtration, thus eliminating the need for precipitation. Using either of these protocols, 96 templates can be prepared in less than 2 h. Sufficient DNA for 1-2 dye primer sequencing reactions is routinely obtained from 1 mL of culture, and the resulting sequence data are of high quality.

Bacteriophage M13↗
PubMed1996

Increased release of tumor necrosis factor-alpha and interleukin-6 in women with the syndrome of hemolysis, elevated liver enzymes, and low platelet count.

BACKGROUND: Complement is activated in preeclampsia and complement products are known to activate macrophages. The aim of this study was to determine whether the macrophage derived cytokines, interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha, are released in patients with a form of severe preeclampsia characterized by the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome). METHODS: Complement activation and plasma levels of cytokines were studied in 11 women with HELLP syndrome and in 11 controls with uncomplicated pregnancies. To further evaluate the connection between complement activation and cytokine release an in vitro study on heparinized whole blood incubated with recombinant C5a was performed. RESULTS: In the HELLP group, complement anaphylatoxin C5a was increased in plasma at delivery (p < 0.01) and one day after delivery (p < 0.05), terminal C5b-9 complement complex was elevated in plasma at delivery (p < 0.001) and one day after (p < 0.01), plasma levels of interleukin-6 were increased one day after delivery (p < 0.01), and plasma concentrations of tumor necrosis factor-alpha were elevated at delivery (p < 0.01), compared with corresponding levels in controls. All parameters normalized within one week. Interleukin-I beta did not differ between the groups. In vitro, recombinant C5a incubated in whole blood gave a dose-dependent release of interleukin-6. No increased release of interleukin-1 or tumor necrosis factor-alpha was seen after incubation. CONCLUSIONS: Since cytokine release occurs in severe preeclampsia, inflammatory mechanisms may participate in the pathophysiology of severe preeclampsia.

Adult↗
PubMed1996

C-reactive protein: the difference between quantitation is serum and EDTA plasma.

We report the differences between using either EDTA plasma or serum in a turbidimetric assay for quantitation of C-reactive protein (CRP). A systematic discrepancy was found for these two sample materials. This was most pronounced in the low concentration range (below 20 mg1(-1)) at which lower values were found in serum than in EDTA plasma. Conversely, in the high concentration range, serum showed slightly higher values. Addition of K3-EDTA to the reaction buffer improved the kinetics for sera with low concentrations of CRP, thus increasing the sensitivity of the assay. We found an overall constant discrepancy of approximately 8% lower values in plasma than in serum (equally for low and high levels of CRP) after the addition of K3-EDTA. The most probable explanation for this effect seems to be the differing water content of serum and EDTA plasma. We discuss the role and function of EDTA in the CRP assay and suggest some hypothetical mechanisms.

Blood Chemical Analysis↗
PubMed1996

The metabolic response to cholecystectomy: insulin resistance after open compared with laparoscopic operation.

OBJECTIVE: To study the changes in insulin sensitivity and plasma concentrations of interleukin-6 (IL-6) after open compared with laparoscopic cholecystectomy. DESIGN: Prospective open study. SETTING: University hospital, Sweden. SUBJECTS: 12 otherwise healthy patients undergoing either open (n = 6) or laparoscopic (n = 6) cholecystectomy. MAIN OUTCOME MEASURE: Relative insulin sensitivity (compared with preoperative) on the day after operation. Changes in IL-6 concentrations postoperatively. RESULTS: The mean (SEM) relative reduction in insulin sensitivity was significantly smaller after laparoscopic (18 (5)%) compared with the open operation, (58 (4)%) (p < 0.01). There was a significant increase in plasma concentrations of IL-6 postoperatively, but there was no difference between the groups. CONCLUSION: Insulin sensitivity is less affected 24 hours after laparoscopic than after open cholecystectomy, which in this study was not accompanied by a simultaneous difference in the IL-6 response. The small postoperative reduction of insulin sensitivity may be a contributing factor to the clinical benefit of improved wellbeing observed after laparoscopic surgery.

Adult↗
PubMed1996

Graft-versus-leukemia effect after allogeneic bone marrow transplantation for chronic lymphocytic leukemia.

We report the case of a patient with chronic lymphocytic leukemia (CLL) with persistent lymphocytosis and lymphadenopathy after allogeneic bone marrow transplantation (BMT). After receiving a donor lymphocyte infusion on day 87 he achieved complete remission upon development of chronic graft-versus-host disease, suggesting that a graft-versus-leukemia effect is operative in this malignancy.

Adult↗
PubMed1996

Allogeneic peripheral blood stem cell transplantation using normal patient-related pediatric donors.

Successful allogeneic peripheral blood progenitor cell (PBPC) transplantation has recently been reported by several transplant centers. This is a first report describing allogeneic PBPC transplantation in five patients using related pediatric donors between the ages of 4 and 13 years. Donors underwent 3 or 4 days of rhG-CSF treatment (6 micrograms/kg q 12 h) for stem cell peripheralization prior to PBPC collection, which was performed by continuous-flow apheresis on day 4 or 5. Venous access was exclusively by ante-cubital veins. A median of 2.2 times (range 1.4-3.6) the donor's total blood volume (TBV) was processed per procedure. In cases where the donor's TBV was < 2 liters, the blood cell separator was primed with human serum albumin (HSA-5%), and anticoagulation was performed using a combination of heparin (pre-apheresis bolus + continuous infusion (CI)) and/or ACD-A (CI at a reduced rate). The median number of CD34+ cells collected per kg of donor body weight (b.w.) and per liter of donor blood processed during each procedure was 128 x 10(4) (range 58 x 10(4)-314 x 10(4)). Between one and two aphereses were sufficient to collect a safe CD34+ cell engraftment dose of 3 or 4 x 10(6)/kg of recipient b.w. Two PBPC recipients were parents, and three were siblings. After freezing and thawing, the median number of CD34+ cells per kg of recipient b.w. thawed and transfused was 8.5 x 10(6) (range 3.2 x 10(6)-9.7 x 10(6)). The time to PMN > 1000/microliters was between 10 and 16 days (four out of five evaluable patients), and platelets > 20000/microliters were reached between day 13 and 14 post-transplantation (three out of five evaluable patients). Two out of three evaluable patients developed grades one and three acute GVHD, and one out of three developed chronic GVHD. Two patients died of sepsis and VOD at day 10 and 19, respectively. Two adult patients are alive and in cytogenetic and molecular remission of CML at +339 and +227 days post-allotransplantation. One 3-year-old girl with hemophagocytic lymphohistiocytosis is in remission at +304 days post-transplantation. Using pediatric donors for allogeneic PBPC transplantation appears to be safe, yields a sufficient amount of progenitors for prompt engraftment, and results in clinical outcome similar to adult PBPC allotransplantation.

Adult↗
PubMed1996

Delayed effects of rhG-CSF mobilization treatment and apheresis on circulating CD34+ and CD34+ Thy-1dim CD38- progenitor cells, and lymphoid subsets in normal stem cell donors for allogeneic transplantation.

Allogeneic transplantation of peripheral blood progenitor cells (PBPC) is emerging as a new stem cell transplant modality. Rather than undergoing general anesthesia for bone marrow harvest, normal blood stem cell donors are subjected to rhG-CSF mobilization treatment followed by single or multiple apheresis. Whereas the effects of cytokine treatment and apheresis on stem cell peripheralization and collection have been described, little is known about delayed effects of rhG-CSF treatment and apheresis on a normal hematopoietic system, and there are no long-term data that address safety issues. Ten normal, patient-related donors underwent a 3 or 4 day rhG-CSF (filgrastim) treatment (12 micrograms/kg/day) followed by single or tandem apheresis. We monitored peripheral blood (PB) cellularity including CD34+ and lymphoid subsets at baseline, during cytokine treatment, prior to apheresis, and at days 2, 4, 7, 30 and 100 post-apheresis. The PB progenitor cell concentration peak prior to apheresis was followed by a nadir by day 7 and normalized by day 30, with the exception of the most primitive CD34+ Thy-1dim CD38- progenitor subset that reached a nadir by day 30. Lymphoid subsets such as CD3, 4, 8, suppressor cells (CD3+ 4- 8- TCR+ alpha beta), and B cells (CD19+) showed a similar pattern with a nadir concentration by day 7, followed, except for B cells, by a rebound by day 30 and subnormal counts at day 100. The PB concentrations of hemoglobin and platelets dropped mainly due to the apheresis procedure itself, and normalized by day 30. With cytokine treatment, the PB alkaline phosphatase and lactate dehydrogenase concentrations increased 2.2- and 2.8-fold, respectively, over baseline, and returned to normal range by day 30. Based on the preliminary nature of this study, the clinical relevance of these findings is still unclear.

ADP-ribosyl Cyclase↗
PubMed1996

Decreased expression of signal-transducing zeta chain in peripheral T cells and natural killer cells in patients with cervical cancer.

An impaired immune response is frequently observed in patients and experimental animals with advanced cancer. We and others have shown alterations in CD3-associated signal-transducing zeta molecules in tumor-infiltrating T cells and peripheral blood lymphocytes (PBLs) of patients with advanced cancer. By using flow cytometric analysis of permeabilized cells with a monoclonal antibody (TIA-2) that reacts with the cytoplasmic domain of the zeta chain, here we demonstrate a marked decrease (P < 0.01) in the expression of the signal-transducing CD3 zeta chain of PBLs in patients with cervical cancer (n = 22) as compared to PBLs from healthy donors (n = 21). In addition, PBLs isolated from patients (n = 23) with cervical intraepithelial neoplasia (CIN), to a lesser but significant (P < 0. 01) extent, expressed reduced CD3 zeta levels as compared to those from healthy donors. This decreased expression of zeta chains was also observed on CD16(+) natural killer cells in PBLs from patients with cervical cancer. Surface expression of CD3 epsilon on PBLs was also decreased in cervical cancer patients as compared to healthy donors, but not on PBLs from patients with CIN. CD3 zeta chain expression significantly (r = 0.53, P < 0.01) correlated with the ability of the PBLs to produce tumor necrosis factor in response to anti-CD3 stimulation. These findings suggest that alterations of signal-transducing zeta molecules commonly occur in patients with cervical cancer and to a lesser extent with CIN, and that they are associated with reduced cellular functions such as production of tumor necrosis factor.

Antibodies, Monoclonal↗
PubMed1995

The nuclear-encoded chlorophyll-binding photosystem II-S protein is stable in the absence of pigments.

The 22-kDa chlorophyll a/b-binding protein (CAB) (psbS gene product) is associated with photosystem II and related to the CAB gene family. Here we report that the PSII-S protein unlike other chlorophyll-binding proteins is stable in the absence of pigments. It is present in etiolated spinach plants and accumulates in the dark progressively with the cellular development of the seedlings. Furthermore, it is present in several pigment-deficient mutants. Analysis of the pigment composition of the PSII-S protein isolated from etiolated plants suggests that neither carotenoids nor chlorophyll precursors are involved in its stabilization in the dark. Exposure of etiolated spinach to light leads to further accumulation of the PSII-S protein, which appears more early than other chlorophyll-binding proteins. Accumulation of the PSII-S protein in green plants is developmentally regulated and restricted to photosynthetic tissues. It is suggested that the function of the PSII-S protein may not be light-harvesting but it could act as a ligand chaperone required for transient binding of pigments during biogenesis or turnover of chlorophyll-binding proteins. Such function would be essential for coordination between pigment biosynthesis and ligation as well as avoiding toxic effects of non-bound chlorophyll molecules.

Carotenoids↗
PubMed1995

Identification of spinach farnesyl protein transferase. Dithiothreitol as an acceptor in vitro.

Spinach seedlings were found to contain farnesyl protein transferase. The enzyme is activated by Zn2+, but not by Mg2+. The pH optimum is approximately 7.0 and maximal activity is obtained at 40-45 degrees C. The apparent Km for the farnesyl diphosphate substrate is 7 microM. Western blotting of soluble proteins with an antiserum raised against mammalian farnesyl protein transferase demonstrated a specific cross-reactivity with the spinach enzyme. The antiserum preferentially recognises the beta-subunit of the heterodimeric farnesyl protein transferase, and the corresponding spinach polypeptide has a molecular mass of 42 kDa on SDS/PAGE. The enzyme can employ dithiothreitol as an acceptor for the farnesyl moiety and catalyses the formation of a thioether linkage between these substrates. On the basis of this discovery, a new method was developed utilising the hydrophobicity of the reaction product, and its interaction with poly(propylene). During in vivo labelling, the plants took up dithiothreitol, which inhibited the incorporation of [3H]mevalonate metabolites into proteins, indicating that dithiothreitol might be isoprenylated in vivo as well as in vitro. However, isoprenylation of some proteins remains unaffected by dithiothreitol suggesting the existence of different isoprenylation mechanisms. Thus, it is demonstrated that plants possess farnesyl protein transferase, which resembles its mammalian and yeast homologues.

Alkyl and Aryl Transferases↗
PubMed1995

Degradation of the D1- and D2-proteins of photosystem II in higher plants is regulated by reversible phosphorylation.

The effects of protein phosphorylation and dephosphorylation upon high-light-induced degradation of the photosystem II reaction center proteins D1 and D2 have been studied in isolated thylakoid membranes and photosystem II core complexes. The rate of photoinactivation of photosystem II electron transport is not affected by thylakoid membrane phosphorylation. However, the degradation rate of the D1-protein in its phosphorylated form is drastically reduced under conditions which induce either acceptor- or donor-side photoinhibition of photosystem II. The degradation rate of the D2-protein is also reduced following protein phosphorylation. The stability of the phosphorylated D1-protein is further increased under conditions of reduced phosphatase activity, suggesting that phosphorylated and damaged D1-protein has to be dephosphorylated prior to proteolytic degradation. Our results expand on experiments performed in vivo, which suggest that following photoinhibition the controlled repair of damaged photosystem II centers requires not only proteolytic enzymes but also kinase and phosphatase activities. It is suggested that the phosphorylation of the D1- and D2-proteins allows tight coordination of the degradation of damaged proteins with insertion of new copies of proteins into photosystem II.

Adenosine Triphosphate↗
PubMed1995

Antioxidant activity of reduced plastoquinone in chloroplast thylakoid membranes.

The antioxidant effect of reduced plastoquinone was studied in chloroplast membranes. Isolated spinach thylakoid membranes were subjected to strong illumination followed by analysis of pigment bleaching and lipid peroxidation. The plastoquinone pool was kept in the reduced or oxidized state during the light stress by the addition of the electron transport inhibitors 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone and o-phenanthroline, respectively. In the absence of inhibitors there occurred a bleaching of carotenoids and chlorophyll a, while chlorophyll b was unchanged. Formation of thiobarbituric acid reactive substances, used as a measure of lipid peroxidation, was negligible during the first hour of strong illumination, but during the second hour there was a marked increase in the rate of lipid peroxidation. Reduction of the plastoquinone pool resulted in a virtually complete inhibition of lipid peroxidation and pigment bleaching. In contrast, conditions of an oxidized plastoquinone pool markedly enhanced lipid peroxidation and pigment bleaching. It is argued that the reduced form of plastoquinone can act as a scavenger of toxic oxygen species generated in the thylakoid membranes during strong illumination.

Antioxidants↗
PubMed1995

In vitro synthesis and assembly of photosystem II core proteins. The D1 protein can be incorporated into photosystem II in isolated chloroplasts and thylakoids.

The D1 reaction center protein of the membrane-bound photosystem II complex (PSII) has a much higher turnover rate than the other PSII proteins. Thus, the D1 protein has to be replaced while the other PSII components are not newly synthesized. In this study, this D1 protein replacement into PSII complexes was followed in two in vitro translation systems: isolated chloroplasts and a homologous run-off translation system consisting primarily of isolated thylakoids with attached ribosomes. The incorporation of newly synthesized radiolabeled products into different (sub)complexes was analyzed by sucrose density gradient centrifugation of n-dodecyl beta -D-maltoside-solubilized thylakoid membranes. This analysis allowed us to follow the release of the nascent polypeptide chains from the ribosomes and identification of at least four assembly steps of the PSII complex, as shown below. (i) Both in isolated chloroplasts and in thylakoids, newly synthesized D1 protein is predominantly incorporated into existing PSII subcomplexes, indicating that synthesis and import of nuclear-encoded factors is not needed for D1 protein replacement. (ii) In chloroplasts, D1 protein incorporation into PSII core complexes is more efficient than during translation in isolated thylakoids. In the thylakoid translation system, a large percentage of radiolabeled D1 protein is found in smaller PSII subcomplexes, like PSII reaction center particles, and as unassembled protein in the membrane. This indicates that stromal factors are required in the replacement process of the D1 protein. (iii) Both in isolated chloroplasts and in thylakoids, the other PSII core proteins D2, CP43, and CP47 are also synthesized and released from the membrane-bound ribosomes, but incorporation into PSII complexes occurs to a much smaller extent than the D1 protein. Instead they accumulate predominantly as unassembled proteins in the thylakoid membrane. (iv) In chloroplasts, synthesis of the D1 protein seems to be adjusted according to the possibilities of incorporation into PSII complexes, while synthesis of the D2 protein, CP43, and CP47 is less regulated and their accumulation as unassembled protein in the membrane is abundant.

Carotenoids↗
PubMed1995

Immunoaffinity column clean-up for the high-performance liquid chromatographic determination of aflatoxins B1, B2, G1, G2, M1 and Q1 in urine.

A method for the determination of aflatoxins B1, B2, G1, G2, M1 and Q1 in human urine has been developed. The 10-ml urine samples were automatically cleaned up on immunoaffinity columns and analysed by high-performance liquid chromatography (HPLC), including post-column derivatization with bromine and fluorescence detection. Average aflatoxin recoveries were: B1 103%, B2 106%, G1 98% and G2 96% in the range 6.8-73 pg/ml of urine and M1 103% and Q1 100% in the range 18-97 pg/ml of urine. The relative standard deviations were all between 1% and 21%. The determination limits of aflatoxins in urine were 6.8 pg/ml for B1, B2, G1 and G2 and 18 pg/ml for M1 and Q1.

Aflatoxin B1↗