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D Moser

Publications and source records attributed to D Moser.

At least 37 records · Page 2Linked to original sources
PubMed1998

Thiopental inhibits migration of human leukocytes through human endothelial cell monolayers in vitro.

OBJECTIVES: The interactions between blood and vascular wall cells are essential for the understanding of pathophysiologic processes, e.g. inflammation. The influence of the anesthetic drug thiopental on leukocyte function is well documented. Recently, an inhibitory effect of thiopental on leukocyte chemotaxis in a Boyden chamber assay (i.e. endothelial cells were not included) was demonstrated. In vivo, leukocytes have to interact with endothelial cell monolayers to invade the tissue. The influence of thiopental on a monolayer of endothelial cells has not yet been investigated. The aim of the current study was to investigate the influence of thiopental on the migration of leukocytes through endothelial cell monolayers (ECM). MATERIAL AND METHODS: Human umbilical vein endothelial cells (HUVEC) were isolated and cultured on microporous membrane filters to achieve a monolayer. Isolated polymorphonuclear leukocytes (PMNL) as well as ECM were preincubated with different concentrations of thiopental. The rate of leukocyte migration against the chemotactic protein formyl-methyl-leucyl-phenylalanine was measured (n = 7). Thiopental was able to reduce the amount of leukocyte migration through ECM significantly. CONCLUSION: In conclusion, we could show that thiopental is able to reduce the migration of PMNL through ECM significantly.

Adult↗
PubMed1998

Leukocyte migration: a new triple migration chamber assay allows investigation of various cell interactions simultaneously.

Examination of the interactions between various cells of the vascular wall and blood components are essential for understanding different pathophysiological processes. Such investigations require appropriate techniques. Several groups have attempted to establish different methods. In all blood vessels except capillaries, endothelial cells (EC) and smooth muscle cells (SMC) coexist and interact very closely. The current study describes a new 3-dimensional triple chamber migration assay, studying leukocyte migration through human endothelial cell monolayers (ECM) towards human SMC layers simultaneously. To test the new assay, SMC-layers were prestimulated with different concentrations of tumor necrosis factor alpha (TNF-alpha, 1 ng/ml, 10 ng/ml, 100 ng/ml) over 6 hours. Then, two microporous membranes, a collecting membrane and a third membrane with cultured ECM, were inserted. Freshly isolated peripheral blood mononuclear cells (PBMNC) were seeded on the ECM and transmigrated cells were measured after further 3 hours incubation. The migration against non stimulated SMC-layers was used as control. Prestimulated SMC-layers led to a dose dependent increase of PBMNC migration into the subendothelial cell space. Antibodies against interleukin-1 reduced the PBMNC migration. In conclusion, this assay allows to study cell migration into the subendothelial space and interactions between different vascular cells. Moreover, this assay can also be used for studies on other cell-cell interactions in man.

Cell Migration Inhibition↗
PubMed1998

Sufentanil inhibits migration of human leukocytes through human endothelial cell monolayers.

UNLABELLED: The interactions between blood and vascular wall cells are essential for understanding pathophysiological processes, e.g., during inflammation. The influence of anesthetics on leukocyte function is well documented. An inhibitory effect of thiopental, midazolam, and ketamine on leukocyte chemotaxis in a Boyden chamber chemotaxis assay (i.e., endothelial cells were not included) has been demonstrated. Little is known, however, about the influence of sufentanil on the inflammatory processes. To reach their targets in the tissue in vivo, leukocytes must interact with endothelial cell monolayers (ECMs). The aim of the current study was to investigate the influence of sufentanil on the migration of leukocytes through an ECM. Human umbilical vein endothelial cells were cultured to achieve a monolayer. Isolated polymorphonuclear leukocytes and ECM were preincubated with different concentrations of sufentanil. The rate of leukocyte migration against the chemotactic protein formyl-methyl-leucyl-phenylalanine was measured (n = 7). Sufentanil significantly reduced the amount of leukocyte migration through ECM to 77%+/-7.8% (P < 0.05 compared with control). Endothelial cells as well as leukocytes contributed to this effect: treatment of both cell types showed an additive effect. Although lower concentrations showed no effect, high concentrations reduced leukocyte migration through ECM to 61%+/-7.1%. IMPLICATIONS: Leukocytes play an important role during inflammation, and anesthetics influence leukocyte functions, e.g., respiratory burst or chemotaxis. The effect of sufentanil on transendothelial leukocyte migration has not been investigated. Therefore, we used a migration assay including endothelial cell monolayers. Sufentanil showed a reducing effect on transendothelial leukocyte migration.

Adult↗
PubMed1998

Ketamine significantly reduces the migration of leukocytes through endothelial cell monolayers.

OBJECTIVE: To study the role of neutrophils in host defense, using human endothelial cells in migration studies in the presence of ketamine (0.3, 3, and 30 microg/mL). DESIGN: Prospective, controlled study. SETTING: University research laboratories. SUBJECTS: Seven independent experiments from different donors were done, investigating the influence of ketamine (0.3, 3, and 30 microg/mL) to the migration of human leukocytes through human endothelial cell monolayers. INTERVENTIONS: Human endothelial cell monolayers and/or human leukocytes were preincubated with clinically relevant (3 microg/mL), higher (30 microg/mL), and lower (0.3 microg/mL) concentrations of ketamine. The amount of leukocyte migration after 3 hrs was measured in a fluorometer. MEASUREMENTS AND MAIN RESULTS: Human endothelial cells isolated from umbilical veins were cultured on microporous membranes (polyethylene-terephthalat membranes) until they formed an endothelial cell monolayer. Leukocytes were separated by standard procedures. The migration of leukocytes through monolayers of endothelial cells under the clinically relevant concentration of ketamine was reduced to 59+/-9.8% (SD) (p< .05) when leukocytes but not the endothelial cell monolayers were preincubated with ketamine. Leukocyte migration was reduced to 92+/-7.3% (p > .05) when only monolayers of endothelial cells were treated with ketamine, and to 52+/-8.8% (p< .05) when both leukocytes and monolayers of endothelial cells were treated with ketamine. The higher and lower concentrations showed a dose-dependent effect. CONCLUSIONS: We investigated the cellular interaction between both cell systems, leukocytes and endothelial cells, simultaneously in the presence of ketamine. Ketamine is able to reduce significantly the migration of leukocytes through endothelial cell monolayers. The use of different dosages revealed a dose-dependent effect. The current model allowed treatment of one cell type, either leukocyte or endothelial cell. Ketamine inhibits the function of leukocytes more than the function of endothelial cells.

Anesthetics, Dissociative↗
PubMed1998

Nitric oxide synthase 1 mRNA: tissue-specific variants from rat with alternative first exons.

We cloned a novel alternative first exon for nitric oxide synthase 1 (NOS1) that is specific for kidney and two novel alternative second exons which can be inserted between the kidney-specific first exon and the exon currently numbered exon 2. The novel exons were localized within 17 kb upstream of exon 2, and their flanking regions and the boundaries of exon 2 were sequenced. NOS1 mRNAs starting with four additional alternative first exons were characterized with respect to tissue distribution and alternative splicing. Altogether, at least 11 different splice variants were found. Those present in kidney were mainly lacking exon 2.

Alternative Splicing↗
PubMed1997

Myocutaneous flaps in patients with head and neck cancer retain their immunological capacities in an activated functional state.

Free/pedicled myocutaneous flaps used as functional replacement after radical dissection of advanced stage squamous cell carcinomas of the oral cavity/oropharynx were examined by immunohistochemistry (APAAP-technique). Biopsies from eight patients were taken at the time of surgery and at 3 and 5 months post-operatively. Fifteen monoclonal antibodies were used to detect surface antigens as markers of phenotypic changes of immune competent cells. In post-operative biopsies all antigens investigated increased significantly. Significantly higher numbers of CD45RO+ (P < 0.01) and CD45RA+ (P < 0.001) leukocytes were detectable. The majority of these leukocytes were TcR alpha/beta +/CD3+ T-cells, which increased in the CD4 (P < 0.05) and the CD8 (P < 0.001) subset. In addition, B-cells (P < 0.05), granulocytes (P < 0.05), NK cells (CD16+ lymphocytic cells; P < 0.05) and mature macrophages (25F9+cells; P < 0.01) were increased. Intra- and subepidermally a significantly (P < 0.01) higher number of dendritic-/Langerhans cells (CD1a+) was detectable. In post-operative biopsies, the activation-associated antigens ICAM-1, VCAM and HLA-DR were expressed on significantly more mononuclear-/endothelial cells and on keratinocytes. Our findings indicate that the myocutaneous flaps still contained cells with immunological capacities.

Aged↗
PubMed1995

Plasmid and chromosomal DNA recovery by electroextraction of cyanobacteria.

High voltage electroporation has been investigated as a method for rapid recovery of plasmid and chromosomal DNA from the cyanobacteria Nostoc PCC 7121, Synechococcus PCC 7002, and Anabaena PCC 7120. Pulses of 18 kV/cm and higher applied to concentrated Nostoc cells carrying a shuttle plasmid (pRL25) resulted in copious release of nucleic acids and phycobiliproteins into the suspending medium. Small portions of these supernatants, when electroporated with Escherichia coli, gave rise to hundreds of E. coli transformants which contained pRL25. Electroporation of Synechococcus carrying plasmid pAQE19 did not cause detectable release of macromolecules but did reveal a low-level, voltage independent 'leakage' of pAQE19 into the medium. Electroextraction of Nostoc or Anabaena followed by addition of E. coli and delivery of a second high-voltage pulse permitted direct, one-cuvette transfer of shuttle plasmids from these cyanobacteria into E. coli. Electroextraction of single cyanobacterial colonies, as shown for Nostoc, also released sufficient chromosomal DNA for amplification of specific sequences by the polymerase chain reaction.

Anabaena↗
PubMed1995

Expression of the thiazide-sensitive Na-Cl cotransporter in rat and human kidney.

An electroneutral thiazide-sensitive Na-Cl cotransport pathway (TSC) has been localized functionally to the distal convoluted tubule (DCT), although the TSC has also been detected in the connecting tubule (CNT), the cortical collecting duct, and the medullary collecting tubule as well. The present experiments were designed to localize expression of message for the TSC in rat and human kidney. A riboprobe, generated from the mouse TSC, was used for in situ hybridization. Simultaneous immunocytochemistry, using antibodies to Tamm-Horsfall protein, band 3, and the Na+/Ca2+ exchanger, permitted delineation of specific nephron segments. In rat, message for the TSC was highly expressed in DCT cells but not elsewhere. The transition from thick ascending limb to DCT was abrupt, whereas the transition to CNT was gradual. In the more distal region of rat DCT (DCT-2), which contained few intercalated cells, both TSC message and Na+/Ca2+ exchanger immunoreactivity were present. Treatment of rats with furosemide for 5 days increased expression of TSC message within the DCT but did not induce its expression elsewhere. In humans, expression of TSC message was also highest in cells of the DCT. In humans, however, expression extended well into the CNT. These experiments indicate that the TSC is expressed predominantly by DCT cells in both rat and humans, although expression extends into the CNT cells in humans. They also show that the TSC and Na+/Ca2+ exchanger are coexpressed by a subpopulation of DCT cells near the junction with the CNT.

Animals↗
PubMed1995

Expression of the thiazide-sensitive Na-Cl cotransporter by rabbit distal convoluted tubule cells.

A thiazide-sensitive Na-Cl cotransporter contributes importantly to mammalian salt homeostasis by mediating Na-Cl transport along the renal distal tubule. Although it has been accepted that thiazide-sensitive Na-Cl cotransport occurs predominantly along the distal convoluted tubule in rats and mice, sites of expression in the rabbit have been controversial. A commonly accepted model of rabbit distal nephron transport pathways identifies the connecting tubule, not the distal convoluted tubule, as the predominant site of thiazide-sensitive Na-Cl cotransport. The thiazide-sensitive Na-Cl cotransporter has been cloned recently. The present experiments were designed to localize sites of thiazide-sensitive Na-Cl cotransporter mRNA expression along the rabbit distal nephron. Nonradioactive in situ hybridization with a thiazide-sensitive Na-Cl cotransporter probe was combined with immunocytochemistry with an antibody that recognizes distal convoluted tubule cells and with a Na+/Ca2+ exchanger antibody that recognizes only connecting tubule cells. The results indicate that thiazide-sensitive Na-Cl cotransporter mRNA is highly expressed by cells of the distal convoluted tubule and not by connecting tubule cells. Segments that stain with the Na+/Ca2+ exchanger antibody (connecting tubules) do not demonstrate thiazide-sensitive Na-Cl cotransporter mRNA expression. We conclude that the predominant site of thiazide-sensitive Na-Cl cotransporter mRNA expression in rabbit distal nephron is the distal convoluted tubule and that sites of mRNA expression of electroneutral Na and Cl transport are similar in rabbits, rats, and mice.

Animals↗
PubMed1993

Predicting death from progressive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

Data were retrospectively reviewed on 528 consecutive patients hospitalized for treatment of advanced heart failure (left ventricular ejection fraction 0.2 +/- 0.07) and cardiac transplant evaluation, who were stabilized with medical therapy and discharged home. Predictors of heart failure death or rehospitalization for urgent transplantation were identified using the Cox proportional-hazards model. Within 1 year, 59 patients (11%) died suddenly and 70 (13%) died of heart failure or required urgent transplantation. A serum sodium < or = 134 mEq/liter, pulmonary arterial diastolic pressure > 19 mm Hg, left ventricular diastolic dimension index > 44 mm/m2, peak oxygen consumption during exercise testing < 11 ml/kg/min and the presence of a permanent pacemaker were independent predictors of hemodynamic deterioration. In the absence of these risk factors the risk of hemodynamic deterioration within 1 year from this study was only 2%. This risk increased to > 50% in the presence of hyponatremia and any 2 additional risk factors. Thus, patients with advanced heart failure at highest risk for progressive hemodynamic deterioration can be identified from clinical variables that could aid in triaging such patients to earlier cardiac transplantation.

Actuarial Analysis↗
PubMed1993

Prognostic usefulness of positive or negative exercise stress echocardiography for predicting coronary events in ensuing twelve months.

Stress echocardiography is useful in diagnosing myocardial ischemia in patients with significant coronary artery disease. This study examines the correlation between the results of exercise stress echocardiography and cardiac event rates within 12 months after testing in patients referred for evaluation of possible myocardial ischemia. Cardiac events, defined as myocardial infarction, coronary artery bypass surgery, percutaneous transluminal coronary angioplasty or death, were tabulated for 360 patients with > or = 12 months of follow-up, or a cardiac event within 12 months of follow-up, or both. Wall motion abnormalities at rest were present in 60% of patients. A positive stress echocardiogram, defined as the development of new or worsened wall motion abnormalities, was obtained in 18% of patients (65 of 360), and > or = 1 cardiac event during follow-up was present in 14% (n = 49). A cardiac event occurred in 34% of patients (22 of 65) with a positive stress echocardiogram and in 9% (27 of 295) with a negative one. Myocardial infarctions occurred in 9% of patients with a positive stress echocardiogram compared with 2% with a negative test. An insufficient exercise capacity to reliably exclude ischemia was present in 63% of patients (17 of 27) with a cardiac event despite a negative stress echocardiogram. The predictive value of the stress echocardiographic results was enhanced by combining these results with the electrocardiographic results. In summary, a positive stress echocardiogram was associated with a threefold increased incidence of any cardiac event, and a fourfold increased incidence of myocardial infarction within 12 months of follow-up compared with a negative stress echocardiogram.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Significance of aborted cardiac arrest and sustained ventricular tachycardia in patients referred for treatment therapy of advanced heart failure.

Cardiac arrest in patients with heart failure may be the result of remediable factors such as pulmonary edema, drug toxicity, or electrolyte abnormalities, or it may be due to primary arrhythmias. The relation of prior aborted cardiac arrest or sustained ventricular tachycardia to subsequent prognosis was assessed in 458 consecutive patients referred for management of advanced heart failure (left ventricular ejection fraction 0.2 +/- 0.07). All patients received tailored vasodilator and diuretic therapy and were then followed as outpatients. Patients were divided into four groups: 388 patients (85%) with no prior cardiac arrest or sustained ventricular tachycardia, 31 patients (7%) with a primary arrhythmia cardiac arrest, 22 patients (5%) with a secondary cardiac arrest, and 17 patients (4%) with sustained ventricular tachycardia without cardiac arrest. Patients with cardiac arrest resulting from a primary arrhythmia were usually treated with antiarrhythmic drugs (25 patients), and five patients received an implantable defibrillator. After hospital discharge actuarial 1-year sudden death risk (17%) and total mortality (24%) rates for the group with primary arrhythmia were similar to corresponding values in patients with no history of cardiac arrest or sustained ventricular tachycardia (17% and 30%, respectively). In patients with a secondary cardiac arrest as a result of exacerbation of heart failure (11 patients), torsade de pointes (10 patients), or hypokalemia (one patient), therapy focused on removal of aggravating factors. Actuarial 1-year sudden death (39%) and total mortality (54%) rates for the group with secondary arrest were higher than for patients without a history of cardiac arrest (p = 0.003 and 0.005, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1992

A stage-specific calcium-binding protein expressed in eggs of Schistosoma mansoni.

A cDNA sequence encoding a Schistosoma mansoni egg antigen SmE16 was cloned in Escherichia coli. The 16-kDa polypeptide deduced from the nucleotide sequence is related to the calmodulin and troponin C gene families of calcium-binding proteins, and the most significant homology is displayed around the four calcium-binding sites. The antigen was expressed as a hybrid protein of the bacteriophage MS2 polymerase. The MS2-SmE16 fusion protein binds calcium, as demonstrated via ligand blotting with 45Calcium. The detection of antibodies to the purified recombinant egg antigen in sera of schistosomiasis patients opens up the possibility that it may be a useful candidate for the development of serodiagnostic assays. The function of the protein in the egg is presently unclear.

Amino Acid Sequence↗
PubMed1991

A 14-kDa Schistosoma mansoni polypeptide is homologous to a gene family of fatty acid binding proteins.

The complete nucleotide sequence encoding a Schistosoma mansoni protein termed Sm14 was determined from cDNA clones propagated in bacteriophage lambda gt11 in Escherichia coli. The 14.8-kDa protein bears significant homologies with a family of related polypeptides which bind hydrophobic ligands. Members of this group of cytosolic proteins were originally identified based on their affinity for long chain fatty acids. The purified recombinant protein exhibited an affinity to fatty acids, in contrast to a mutant lacking 16 N-terminal amino acids. Immunofluorescence experiments show that tubercles, which are structures located on the dorsal surface of adult male schistosome and known to contain lipids, are stained using antibodies raised to the beta-galactosidase fusion protein. A regular staining pattern is also evident in the muscle layers as well as in the body of the parasite. As the schistosome cannot synthesize fatty acids de novo and is dependent on the uptake of lipids from serum, the available data support a role for Sm14 in the transport of fatty acids.

Animals↗
PubMed1991

Acidic cytochrome c6 of unicellular cyanobacteria is an indispensable and kinetically competent electron donor to cytochrome oxidase in plasma and thylakoid membranes.

Cytochromes c6 from three cyanobacteria were tested as substrates for membranous cyt. c oxidase(aa3) of Anacystis and Synechocystis using intact spheroplasts or isolated plasma(CM) and thylakoid(ICM) membranes. Neither spheroplasts nor CM/ICM gave significant O2 uptake rates with NADH without added cyt. c. Horse cyt. c (at low ionic strength) or cyt. c6 from Anacystis, Synechocystis or Microcystis (at high ionic strength) supported substantial HCN- & CO-sensitive NADH oxidase activity, consistent with in vivo O2 uptake. Cyanobacterial respiratory electron transport involves NADH dehydrogenase(fpN), plastoquinone, cyt. b/c(f), cyt. c6 & cyt. aa3, in both CM & ICM. In ICM, fpN and cyt. aa3 are functionally replaced in the light by PS II and PS I, respectively. In both membranes, cyt. c6 is an obligatory electron donor to cyt. aa3 &/or to P700. Respiratory action of acidic cyt. c6 (in unicellular species) may be unmasked only under conditions of elevated ionic strength.

Animals↗
PubMed1991

Immunological analysis of cloned Schistosoma mansoni antigens Sm31 and Sm32 with sera of schistosomiasis patients.

Two immunogenic proteins, Sm31 and Sm32, originating from the gut of Schistosoma mansoni were evaluated for their potential as recombinant immunodiagnostic reagents. Sm31 and Sm32 cDNA fragments were cloned and expressed in Escherichia coli as polypeptides fused to RNA polymerase of bacteriophage MS2. The recombinant proteins were tested in enzyme-linked immunosorbent assays (ELISA) with paired sera of 182 persons from Mali with S. mansoni and S. haematobium infections collected before and one year after treatment with praziquantel. Pretreatment sera of the study population gave a strong antibody response to Sm31 and Sm32 in immunoblots of total worm extract with the sera. The sensitivities of both western blotting (86%) and ELISA (75%) using Sm31 and Sm32 fusion proteins compared well with a single egg count (84%). Chemotherapy resulted in an overall decline of egg counts. Posttreatment sera gave significantly lower reactivities than the pretreatment sera. Our results demonstrate the feasibility of detecting circulating antibodies with recombinant antigens in schistosomiasis.

Adolescent↗