Biomedical subjects

W Goossens

Publications and source records attributed to W Goossens.

At least 19 recordsLinked to original sources

PubMed2000

In vitro activity of gemifloxacin compared with other antimicrobial agents against recent clinical isolates of streptococci.

This study investigated the in vitro activity of gemifloxacin (SB-265805) against 50 recent clinical isolates of Streptococcus pyogenes, Streptococcus agalactiae and viridans streptococci using the microdilution method. This activity was compared with that of the quinolone agents ofloxacin, ciprofloxacin, levofloxacin, trovafloxacin and grepafloxacin, and with that of penicillin, ampicillin, clarithromycin and azithromycin. Gemifloxacin was significantly more potent than the other quinolones tested. Its potency was equal to that of penicillin for S. agalactiae, and superior to that of penicillin for viridans streptococci. The MIC(50) of gemifloxacin for S. pyogenes (0.015 mg/L) was equal to that of penicillin, with an MIC(90) of 0.03 mg/L. Gemifloxacin was also active against isolates of S. agalactiae (MIC = 0.03-0.06 mg/L) and S. pyogenes (MIC = 0.03- 0.06 mg/L) with reduced susceptibility to ofloxacin (MIC = 4-8 mg/L) and grepafloxacin (MIC = 4 mg/L). These preliminary observations indicate that gemifloxacin is a promising antimicrobial agent for clinical use.

Anti-Infective Agents↗

PubMed1999

The presence of transcription factors in chicken albumin, yolk and blastoderm.

Embryonic development is determined by preset intrinsic programs and extrinsic signals. To explore the possibility that transcription factors are present at the onset of development, preparations of yolk, albumin, and blastoderm from unfertilized and fertilized white Leghorn chicken eggs were screened by a panel of 16 transcription factor antibodies with Western blot techniques. Yolk was positive for 13 transcription factors, whereas blastoderm was positive for 10, and albumin was positive for 5. In yolk, several transcription factors, GATA-2, E2F-1, MyoD, and TFIID, were developmentally regulated. These results indicate that intracellular yolk and extracellular albumin contain transcription factors which presumably influence early chick embryonic development from prefertilization to the late blastoderm stage. Thus, the utility of preset maternal transcription factors within yolk and albumin complement maternally derived mRNA to determine the early development of the zygote.

Albumins↗

PubMed1998

The presence of transcription factors in fetal bovine sera.

Three sources of fetal bovine serum (FBS) were fractionated by ammonium sulfate precipitation and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), transferred to Immobilon-P membranes, immunoblotted with a panel of transcription factor antibodies, and detected by enhanced chemiluminescence. Nine transcription factors were detected--ATF-2, SRE-ZBP, GATA-2, TFIID, Ets-1/Ets-2, E2F-1, Oct-2, p53, and AP-2; four transcription factors were not detected--Myo D, CREB, Sp2, and Wilms' tumor. The results indicated the presence of varying amounts of several transcription factors in three commercial sources and may represent heretofore unrecognized factors influencing cell culture.

Animals↗

PubMed1998

CD44H localization in primary open-angle glaucoma.

PURPOSE: Primary open-angle glaucoma (POAG) is associated with a decreased content of hyaluronan in the trabecular meshwork and in the juxtacanalicular connective tissue. In this study, the authors examined selected regions of the anterior segment to localize and determine the content of CD44H, a transmembrane multifunctional glycoprotein and the principal receptor of hyaluronan. METHODS: Sections of ethanol-fixed anterior segments of six POAG and six normal postmortem eyes were analyzed by immunostaining with and without the nonionic detergent Triton X-100, using the CD44H monoclonal antibody, and the avidin/biotin complex. They were visualized by Vector VIP substrate and were quantitated by computer-aided color image analysis. RESULTS: CD44H was expressed in all regions. Statistically significant decreased content of CD44H was observed in the POAG regions compared with normal regions--ciliary muscle (P < 0.001), ciliary stroma (P < 0.001), anterior iris (P < 0.05), iris root (P < 0.05), and trabecular meshwork (P < 0.05)--and in a subgroup of nonlaser POAG juxtacanalicular connective tissue (P < 0.05) and trabecular meshwork (P < 0.01). In sections treated with Triton X-100 a further increase in immunostaining was observed in normal eyes. As evidenced by scattergram plots of the ciliary body stroma region of the change in the optical density of CD44H between pretreatment with Triton X-100 and without Triton X-100 (y axis) versus the optical density of CD44H without Triton X-100 (x axis), individual cases of POAG were separated from normals. CONCLUSIONS: These results indicate that CD44H may represent a marker of POAG and an etiologic factor in the POAG disease process.

Aged↗

PubMed1997

Pathological changes in exposed neural tissue of fetal delayed splotch (Spd) mice.

If meningomyelocele is indeed a progressive intrauterine process, then early delivery or possibly intrauterine repair of meningomyelocele becomes an issue. Utilizing the delayed splotch (Spd) mouse, a genetically transmitted neural tube defect model, we looked for evidence of abnormalities of neural tissue exposed to amniotic fluid. Affected embryonic and fetal mice were examined with the light microscope, and also with the transmission and scanning electron microscope. Neuronal development and programmed cell death paralleled normal fetal development. No evidence of inflammation on or within the exposed neural tissue was observed. Because the vascular supply to the alar and basilar plate are different, vascular development was also examined and no difference could be found. In conclusion, we found no evidence of deterioration of the exposed neural tube during the gestational period of a mouse, which suggests that exposure of unneurulated spinal cord to amniotic fluid is not a risk factor to the fetus with a neural tube defect.

Amniotic Fluid↗

PubMed1997

Evaluation of the Abbott Cell Dyn 4000 automated fluorescent reticulocyte measurements: comparison with manual, FACScan and Sysmex R1000 methods.

The Abbott Cell Dyn 4000 (CD4000) is the first haematology analyser in which fully-automated reticulocyte measurements can be routinely determined by fluorescence as part of the full blood count. This communication reports the first evaluation of this method which was undertaken by three independent reference laboratories in Belgium, Germany and Italy. A total of 695 different samples was entered into the study which was designed to compare CD4000 reticulocyte information (enumeration and qualitative maturational data) with results determined in parallel with the existing manual (supravital staining) reference procedure, and two semi-automated fluorescent assays (Becton Dickinson FACScan and Sysmex R1000 instruments). These studies revealed good agreement between the CD4000 and the manual procedure, with no inter-method bias. Comparison of CD4000 and FACScan reticulocyte measurements, however, indicated a distinct tendency for the FACScan to give higher reticulocyte estimates than the CD4000. Finally, the comparison of the CD4000 with the Sysmex R1000 showed excellent agreement in the range 0-6% reticulocytes, although there was some inter-method bias in the higher range (> 15%). Analysis of agreement levels between the methods using specific 'clinical decision points' confirmed the tendency for overestimation by the FACScan, in that 58% of the samples with a reticulocytopenia of < 0.5% as defined by the CD4000 gave FACScan results within the normal range (0.5-1.8%). In contrast, there was absolute agreement between the CD4000 and the Sysmex R1000 for all reticulocytopenias. Comparison (195 samples) of instrument fluorescent reticulocyte maturation profiles demonstrated an exponential relationship (r = 0.78) between CD4000 IRF and R1000 HFR (highly fluorescent reticulocyte fraction) values. The suggestion that the CD4000 IRF values includes some of the MFR as well the HFR reticulocyte fraction was confirmed as the correlation between the CD4000 IRF and the Sysmex R1000 MFR plus HFR percentages was linear (r = 0.82). This study confirms a high performance level for the CD4000 automated fluorescent reticulocyte method.

Autoanalysis↗

PubMed1996

Glycosaminoglycans of the human trabecular meshwork in primary open-angle glaucoma.

PURPOSE: Glycosaminoglycans (GAGs) contribute to the filtration barrier of aqueous outflow through the trabecular meshwork (TM). The purpose of this biochemical study was to identify the type and amount of GAGs in normal and in primary open-angle glaucoma (POAG) TM and adjacent anterior segment structures. METHODS: The GAGs of 21 masked individual normal and POAG human TMs, as well as iris, ciliary body, and anterior sclera, were isolated biochemically, identified by selective GAG-degrading enzymes, and quantitated by computer-enhanced densitometry. RESULTS: In 10 normal TMs (8 donors, 65 to 83 years of age), the GAG profile was: hyaluronic acid (0.77 +/- 0.26 ng/microgram dry-defatted weight +/- SEM); chondroitin 4(6-) sulfates and dermatan sulfate, collectively referred to as chondroitin sulfates (1.90 +/- 0.13 ng); keratan sulfates (0.33 +/- 0.06 ng); heparitin sulfates (2.02 +/- 0.52 ng); GAG enzyme-resistant material (0.02 +/- 0.01 ng); and total GAGs (5.05 +/- 0.70 ng). In 10 POAG TMs (6 donors, 67 to 88 years of age), the GAG profile was: hyaluronic acid (0.18 +/- 0.11 ng; P < 0.02, a 77% decrease; 6 of 10 TMs contained no detectable hyaluronic acid); chondroitin sulfates (2.39 +/- 0.31 ng); keratan sulfates (0.21 +/- 0.06 ng); heparitin sulfates (1.36 +/- 0.43 ng); GAG enzyme-resistant material (0.08 +/- 0.01 ng; P < 0.02); and total GAGs (4.09 +/- 0.33 ng; statistically insignificant). In the POAG iris, hyaluronic acid content was less (82% decrease, P < 0.02), and the chondroitin sulfates content was higher (72% increase, P < 0.02). Similarly, the POAG ciliary body and anterior sclera contained less hyaluronic acid and more chondroitin sulfates. The GAG profile of a "glaucoma suspect" donor specimen was similar to that of the POAG donor specimen. CONCLUSIONS: The data provide the first quantitative biochemical profiles of GAGs of individual normal and POAG TM, and we suggest that a depletion of hyaluronic acid and the accumulation of chondroitin sulfates may increase aqueous outflow resistance in the POAG TM:

Aged↗

PubMed1996

Glycosaminoglycan stratification of the juxtacanalicular tissue in normal and primary open-angle glaucoma.

PURPOSE: The juxtacanalicular tissue (JCT) is the probable site of aqueous outflow resistance in normal eyes and of the increased resistance in primary open-angle glaucoma eyes (POAG). The purpose of this histochemical study was to determine the glycosaminoglycan (GAG) composition and stratification in the JCT of POAG and age-matched normal eyes. METHODS: Five eyes from four normal donors and five eyes from four POAG donors (69 to 80 years of age) were analyzed. Using methods that histochemically preserve GAGs, GAG-degrading enzymes, Alcian blue staining, and real color discrimination to exclude pigment, nuclear staining and unstained areas, the type and amount of GAGs were estimated by compute-raided charge-coupled device color video image analysis. To examine GAG stratification, the JCT was segmented into three regions-anterior, middle, and posterior-to examine regional differences in GAG composition; each region was further divided into four 2-microns layers, from layer 1, adjacent to and including the endothelium of Schlemm's canal, to layer 4, to the first trabecular lamellae. RESULTS: The normal GAG JCT profile was as follows: hyaluronic acid (HA), 7.78 +/- 1.23 femtograms (fg)/micron2; chondroitin sulfates (CS), 8.18 +/- 0.82 fg/micron2; dermatan sulfate, 0.29 +/- 0.18 fg/micron2; the total, 18.73 +/- 0.68 fg/micron2. In contrast, the POAG GAG JCT profile was as follows: HA 0.57 +/- 0.31 fg/micron2 (P < 0.00001), a 93% decrease; CS 13.49 +/- 0.74 fg/micron2 (P < 0.0001), a 83% increase; dermatan sulfate, 0.90 +/- 0.53 fg/micron2; and the total, 17.31 +/- 0.95 fg/micron2, an 8.2% decrease. The HA was depleted in all layers of all regions of POAG JCT. CONCLUSIONS: Results indicate that the normal JCT is stratified, with HA as the predominant GAG in layers 1 and 2. The POAG JCT is depleted of HA and has an accumulation of CS, which may increase outflow resistance and, consequently, increase intraocular pressure in patients with POAG.

Aged↗

PubMed1995

Reduced glutathione for the treatment of anemia during hemodialysis: a preliminary communication.

In 4 chronic hemodialysis patients we have tested whether the administration of reduced glutathione (GSH; Glutamed, Boehringer Mannheim Italia; 1,200 mg i.v.) at the end of each hemodialytic session during 90 days could minimize oxidative damage to the red blood cells (RBC) and reduce the recombinant human erythropoietin requirements. Treatment with GSH was followed by an increase in RBC GSH content (n = 3), a normalization of the ascorbine cyanide test (n = 4), an increase in RBC survival (n = 3), and a reduction in 2 patients of the erythropoietin need (41 and 26%, respectively, after 3 months of therapy). When the GSH supplements were terminated, we noticed after 3 months a re-establishment of the baseline values. On the other hand, malonyldialdehyde, RBC deformability, and RBC splenic pool were abnormal before and remain abnormal during the test period. Since no adverse reactions were noticed, these findings seem to indicate the GSH could ameliorate the intraerythrocytic oxidative defense and could be as useful drug in the treatment of anemia in patients affected by chronic renal failure.

Aged↗

PubMed1994

Storage of saline-adenine-glucose-mannitol suspended red cells in diethylhexyl phtalate and butyryl-n-trihexyl-citrate plasticized polyvinyl chloride containers. An in vitro comparative study.

Units of whole blood collected into butyryl-n-trihexyl-citrate (BTHC) and diethylhexyl phtalate (DEHP) plasticized polyvinylchloride (PVC) blood storage containers and processed by means of an 'Optipress', which allows automated removal of the buffy coat, were compared. Units collected into standard PVC containers processed by the traditional method (no buffy coat removal) were used as a control group. The red cell concentrates were suspended in saline-adenine-glucose-mannitol (SAGM) and stored 42 days at 2-6 degrees C. Comparison of the buffy coat depleted red cell concentrates showed that red cell energy and oxygen delivery capacity, as evidenced by ATP and 2,3-DPG values, were slightly better preserved in the BTHC plasticized container, compared to the DEHP container. The red cell membrane, however, was slightly less well preserved, (the hemolysis at day 42 with BTHC ww 0.39%; with DEHP, 0.20%) in this container. The higher ATP levels might lead to a better in vivo recovery of stored red cells. In vivo studies comparing both plastic containers, therefore are indicated in order to determine if these differences have practical significance. A longer holding time of the whole blood at room temperature before processing reduced the hemolysis (42 days stored RCC as 0.26%). Slightly more fibrinopeptide A (FPA) generation and marginally lower pH and 2,3-DPG values were observed in this situation. This finding suggests an effect of higher plasticizer levels on the red cell membrane.

Adenine↗

PubMed1994

Quality of washed salvaged red blood cells during total hip replacement: a comparison between the use of heparin and citrate as anticoagulants.

A randomized, prospective study comparing heparin with citrate (ACD) as anticoagulant during red blood cell saving was performed in 10 ASA grade I-II patients undergoing primary total hip replacement. Blood samples were taken before and after surgery and at several steps during cell saving. In the heparin group, salvaged red cells showed normal values, with the exception of decreased filtrability and moderate hemolysis. More differences in red cell quality were found in the ACD group. Mean corpuscular volume was higher (110 vs 95 x 10(-12) mL), red cell distribution was increased (17% vs 13%), osmotic resistance was lower (0.54 vs 0.43 g NaCl/L at 50% hemolysis), antioxidative reserve capacity was lower (1.9 vs 4.6 U glutathione reductase per gram of hemoglobin) and there was more hemolysis (15% vs 11%). Despite the small volume of autologous blood retransfused (388 +/- 92 mL), the differences in vitro produced significantly higher free hemoglobin levels in the patients' plasma at the end of the operation (58 vs 23 mg/dL). We conclude that heparin is preferable to citrate as an anticoagulant during autotransfusion with cell washing and immediate retransfusion.

Anticoagulants↗

PubMed1993

Osmotic effects of dilution on erythrocytes after freezing and thawing in glycerol-containing buffer.

Red blood cells frozen in 1.7 M and particularly in 2.2 M of glycerol retain a high degree of integrity upon thawing as long as the dilution procedure of the cryoprotectant is slow and preferentially compensated by the addition of sorbitol. As the nonpenetrating cryoprotectant sorbitol induces initial cell shrinkage, cell swelling upon dilution of the cryoprotectants may not lead to hemolysis. However, rapid dilution of glycerol even with buffer containing up to 0.50 M of sorbitol cannot be achieved without provoking considerable hemolysis. Due to the relative slow rate at which glycerol leaves the cells, membrane damage to the younger cell populations remains considerable and is even more pronounced in the older cell groups. The dramatic osmotic changes occurring during the dilution process lead to the formation of aberrant cell populations as demonstrated by the red cell size frequency distribution curves.

Buffers↗

PubMed1993

Comparative evaluation of three flow cytometers for reticulocyte enumeration.

Flow cytometric determination of reticulocytosis is progressively replacing the manual microscopic method. We evaluated three flow cytometers (Becton Dickinson FACScan, Coulter EPICS Profile II, Ortho Cytoron Absolute) for reticulocyte enumeration, using thiazole orange. For each sample, 30,000 cells were analysed. In order to comparatively evaluate the three instruments, reticulocytes were counted by manually gating the erythroid population and evaluating the gated population for fluorescence characteristics. The different instruments showed good linearity and precision. No carry-over was observed. Orthogonal regression analysis of reticulocyte counts of 100 healthy blood donor samples and 108 haematological patient samples showed a good mutual comparability between all three instruments tested, although the paired t-test showed a significant difference between the Cytoron and both the FACScan and the Profile. Despite minor statistical differences, the three instruments can be considered equivalent for daily routine reticulocyte enumeration.

Benzothiazoles↗

PubMed1993

Serum erythropoietin levels in elderly inpatients with anemia of chronic disorders and iron deficiency anemia.

OBJECTIVE: To analyze the relationship between serum erythropoietin levels and hemoglobin levels in elderly patients with anemia of chronic disorders related to cancer or acute infection when compared with anemic patients with iron deficiency. DESIGN: Prospective survey with comparison groups. SETTING: Tertiary care center. PATIENTS: An elderly group aged 70 and above (mean 84, range 70-96) was divided into subgroups of 45 with anemia of chronic disorders (23 with cancer and 22 with acute infection), 24 with iron-deficiency anemia, and 27 with no anemia. Thirty non-anemic younger adults were also studied. MEASUREMENTS: Serum erythropoietin (radioimmunoassay), complete blood count, serum iron, B12, folate and ferritin, liver and kidney function tests, blood gas analyses, and bacteriological and radiological tests. RESULTS: The serum erythropoietin levels were significantly lower in the elderly non-anemic hospitalized group than in the healthy younger group. A significant negative relationship between the log serum erythropoietin and hemoglobin levels was found in patients with iron deficiency, but not in the other groups. For any given hemoglobin level, the response of erythropoietin was significantly higher in anemic patients with iron deficiency when compared with the neoplastic and infectious group. CONCLUSION: Erythropoietin response to anemia is blunted in elderly patients with anemia of chronic disorders related to cancer or acute infection. Erythropoietin level is lower in non-anemic elderly inpatients than in healthy younger persons.

Acute Disease↗

PubMed1993

Cobalamin absorption and serum homocysteine and methylmalonic acid in elderly subjects with low serum cobalamin.

We prospectively studied 41 consecutive elderly patients with serum cobalamin (vitamin B12) levels lower than 125 pmol/l. The protein-bound cobalamin absorption test (PBAT) was performed in 34 of them and in 27 selected elderly control patients. The lower decision limit was 0.18% and an abnormal test was detected in only 9 (26%) of the 34 patients with low serum cobalamin level. When the PBAT was compared to the Schilling (Dicopac method) test, a concordant result was found in 80%. Serum methylmalonic acid and/or total homocysteine concentrations were elevated in 75% (26/35) of the patients with low serum cobalamin levels but also in 30% (5/17) of the control patients. Of the 12 and 9 cobalamin-deficient patients with elevated serum levels of methylmalonic acid and homocysteine, normalization after cobalamin therapy was obtained in 11 and 5 respectively. In conclusion, determination of serum metabolites and their response to cobalamin therapy are a sensitive index of significant cobalamin deficiency and a useful means of distinguishing between cobalamin and folate deficiency. The PBAT offers little advantage over the Schilling test in diagnosing cobalamin malabsorption in elderly patients.

Aged↗

PubMed1993

Oxidative injury to erythrocytes, cell rigidity and splenic hemolysis in hemodialyzed patients before and during erythropoietin treatment.

The oxidative injury to erythrocytes, red blood cell (RBC) rigidity and splenic hemolysis was assayed in 17 chronically hemodialyzed patients before and during recombinant erythropoietin (EPO) treatment. When a stable hematocrit between 30 and 35% had been established for at least 4 months, a statistically significant increase in RBC volume, hemoglobin concentration, hematocrit, reticulocyte count, and several RBC enzymes (2,3-diphosphoglycerate, glucose 6-phosphate dehydrogenase, pyruvate kinase, hexokinase) was noted. This indicated significant RBC rejuvenation under the influence of EPO. However, no significant improvement in the RBC oxidative sensitivity, RBC deformability, splenic RBC volume, slow mixing splenic RBC volume, and the intrasplenic RBC transit time could be disclosed. These data confirm the existence of an extra-erythrocytic factor in uremic plasma, which is partly responsible for a reduced RBC life span in hemodialysis patients despite EPO treatment.

Adult↗

PubMed1992

Measurement of serum cytokine levels in patients with myelodysplastic syndromes.

Sera of 25 healthy controls and 75 patients suffering from myelodysplastic syndromes (MDS) were investigated for serum concentration of interleukin-1 alpha (IL-1 alpha), IL-3, IL-6, granulocyte-colony-stimulating factor (G-CSF), granulocyte-macrophage-CSF (GM-CSF), erythropoietin (Epo), and tumor necrosis factor-alpha (TNF-alpha). According to French-American-British (FAB) classification, 21 refractory anemia (RA), seven refractory anemia with ring sideroblasts (RARS), 15 chronic myelomonocytic leukemia (CMML), 12 refractory anemia with excess of blasts (RAEB), and 20 RAEB in transformation (RAEBt) were examined. TNF-alpha levels were inversely correlated with lower levels of hemoglobin concentration (r = -0.31, p = 0.005), irrespective of the requirements for transfusion in anemic MDS patients. Significant differences in TNF-alpha levels between CMML (26.2 +/- 5.9 pg/ml) and the FAB subgroups (16.1 +/- 1.6 pg/ml) were detected. There was an overall inverse relationship between the level of erythropoietin and the degree of anemia, but a wide range of Epo response between patients with similar hemoglobin concentrations. Serum levels of IL-1 alpha and GM-CSF were undetected in most of the patients. In 57% of the samples there were detectable levels of G-CSF, without a correlation of the serum levels with blood cell counts, nor with any of the FAB subcategories. Overall, 29% and 25% of the patient sera exhibited elevated IL-3 and IL-6 levels, respectively. There was no correlation of the serum levels with any of the blood counts, other cytokines, nor FAB subcategories. In conclusion, simple negative feedback mechanism between a specific cytokine and the production of blood cells seems not to be the case in MDS, except for red cell production and erythropoietin concentration. Our data may suggest the involvement of TNF-alpha in the pathogenesis of anemia in MDS.

Adolescent↗

PubMed1991

The prevention of erythrocyte swelling upon dilution after freezing and thawing.

Cellular swelling of erythrocytes exposed to Me2SO during freezing and thawing may lead to hemolysis upon dilution of the cryoprotectant with pure electrolyte buffer. Excessive cell swelling is effectively avoided by exposing the RBC to the nonpenetrating sorbitol after thawing and before dilution. Due to the initial reduction in volume by sorbitol, cell swelling upon dilution may not cause hemolysis particularly with concentrations of 0.05 to 0.15 M of sorbitol in the diluting electrolyte buffer. Membrane damage incurred during freezing and thawing is particularly pronounced with the older red cell population, while the younger population membrane integrity can be preserved to an optimal degree.

Blood Preservation↗