bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Caffeine on Topographic Quantitative EEG
Authors: Siepmann Martin , Kirch Wilhelm 
Published: April 2003

Despite the widespread use of caffeine as a central nervous stimulant, the central pharmacodynamic properties of the drug have not yet been conclusively evaluated in humans. The present study was undertaken to assess the acute effects of caffeine on measures of topographical quantitative electroencephalogram (EEG) in normal subjects. Ten healthy male volunteers (mean age ± SD 25 ± 4 years) received placebo and 200 mg of caffeine as powder with oral water solution (caffeine amount = 2 cups of coffee) under randomized, double-blind crossover conditions on two different occasions. Before administration and 30 min afterwards, a 17-channel quantitative EEG was recorded during relaxation with eyes open and closed (15 min each). Caffeine caused a significant reduction of total EEG power at fronto-parieto-occipital and central electrode positions of both hemispheres when the subjects kept their eyes open. Absolute power of the slow and fast alpha and slow beta activities was diminished in various regions of the brain (p < 0.05). The effect was more pronounced with the subjects keeping their eyes open than with eyes closed. It can be concluded that quantitative EEG is a sensitive method to assess the effects of psychostimulants on the human brain. Therefore, in pharmaco-EEG studies, environmental factors such as caffeine have to be excluded.
Retinoic Acid Increases in the Retina of the Chick with Form Deprivation Myopia
Authors: Seko Yuko , Shimizu Masato , Tokoro Takashi 
Published: April 2003

We previously reported that expression of retinoic acid receptor β increases in the sclera of the 2-week-old chick with form deprivation myopia (FDM) and that all-<i>trans</i>-retinoic acid (<i>t</i>-RA) influences proliferation and differentiation of scleral cells. The purpose of this study was to quantify <i>t</i>-RA in the retina of the chick with FDM and to investigate the role of <i>t</i>-RA in FDM in the chick. FDM was induced in 2-day-old chicks by placement of a translucent plastic goggle over one eye, with the contralateral eye used as a control. After 5 days, the chicks were sacrificed. <i>t</i>-RA was extracted from neural retina and served for high-performance liquid chromatography analysis. <sup>3</sup>H-<i>t</i>-RA was used for normalization. Pieces of the retinae from 5 eyes served as one sample. As a result, <i>t</i>-RA was 0.960 ± 0.086 ng/eye (0.387 ± 0.056 ng/mg protein) in the myopic retina and 0.864 ± 0.108 ng/eye (0.319 ± 0.043 ng/mg protein) in the control retina. The concentration of <i>t</i>-RA (ng/mg protein) in the myopic retina was significantly higher than that in the control (p < 0.05, n = 7). These results demonstrate that <i>t</i>-RA increases in the retina within 5 days after visual deprivation. This finding suggests that <i>t</i>-RA may play a role in the metabolic changes in FDM.
Serotonin-2A Receptor mRNA Expression in Rat Retinal Pigment Epithelial Cells
Authors: Nash Mark , Flanigan Thomas , Leslie Ron , Osborne Neville 
Published: April 2003

Previous studies have shown that rat retinal pigment epithelial (RPE) cells in culture express 5-HT<sub>2</sub>-type serotonin receptors coupled to phospholipase C activity. The presented data confirm this observation where it is shown that serotonin induced increases in radioactive inositol phosphates accumulation in RPE cells pretreated with tritiated inositol. This increase was significantly (p < 0.01) attenuated by 1 µM spiperone, ketanserin, mesulergine and metergoline while the same concentration of spiroxatrine or yohimbine had no effect, suggesting the involvement of 5-HT<sub>2A</sub> receptors. Using reverse transcriptase-polymerase chain reaction the presence of 5-HT<sub>2A</sub> receptor mRNA was demonstrated in total RNA isolated from rat RPE cell cultures. Amplification of a 5-HT<sub>2A</sub> receptor mRNA-derived product was additionally confirmed by Southern blot analysis. The combined data demonstrates the existence of functional 5-HT<sub>2A</sub> receptors in rat RPE cells.
In vitro Testing of Antioxidants and Biochemical End-Points in Bovine Retinal Tissue
Authors: Chida M. , Suzuki K. , Nakanishi-Ueda T. , Ueda T. , Yasuhara H. , Koide R. , Armstrong D. 
Published: April 2003

Lipid peroxidation in aliquots of bovine retina (without rod outer segments, ROS), purified ROS and retinal pigment epithelium (RPE) was initiated with 5 m<i>M</i> ferric iron and 80 m<i>M</i> ADP. After 30 min of oxidation at 37°C, the concentration of thiobarbituric-acid-reacting substances (TBARS) which approximates lipid hydroperoxide (LHP), increased in the ROS from 2.0 ± 3.6 to 90.2 ± 34.5 nmol malondialdehyde (MDA)/mg protein and in the RPE from 0.54 ± 0.2 to 51.5 ± 15.8 nmol MDA/mg protein. Sixteen lipid and aqueous antioxidants (AOX) from natural or synthetic sources, including five flavonoids, were evaluated for their ability to inhibit the oxidative reaction. Palm-oil-derived vitamin E showed significant protection in retina, ROS and RPE (64, 68 and 74%), respectively. Of the flavonoids tested, good protection in the retina was found at 10<sup>–5</sup><i>M</i> for epigallocatechin gallate (50%) and at 50 ng/ml for pycnogenol (61%) and catechin (52%). When catechin and palm oil vitamin E, catechin and coenzyme Q<sub>10</sub> or coenzyme Q<sub>10</sub> and pycnogenol were combined, the individual effect was enhanced. TBARS as an indirect measure of LHP level and hemoglobin-methylene blue determination for direct LHP were used as alternative end-point determinations of lipid peroxidation. These measure different aspects of AOX reactions. The results demonstrate the usefulness of an in vitro model system that can rapidly and accurately determine the capacity of a single AOX against lipid peroxidation or be used to show synergistic efficacy.
Effect of Insulin-Like Growth Factors 1 and 2, and Glucose on the Migration and Proliferation of Bovine Retinal Pigment Epithelial Cellsin vitro
Authors: Spraul Christoph W. , Kaven Corinna , Amann Josef , Lang Gerhard K. , Lang Gabriele E. 
Published: April 2003

<i>Background:</i> The retinal pigment epithelium (RPE) has been implicated in the development of diabetic retinopathy and it has been suggested that insulin-like growth factors (IGF) and glucose may be among those factors which are responsible for the RPE changes in diabetics. The purpose of this study was to investigate the effect of IGF-1, IGF-2, and glucose on the migration and proliferation of bovine RPE cells in vitro. <i>Methods:</i> Primary cultures of bovine RPE cells were established from freshly enucleated eyes and passages 5–8 were used for these experiments. RPE cell migration was studied in confluent RPE cultures grown in multiwell plates. After inhibition of proliferation with mitomycin C (10 µg/ml) and partial denudation of the RPE in each well, the cells were incubated with IGF-1 (10 ng/ml), IGF-2 (10 ng/ml) or glucose (10 m<i>M</i>). Migration was measured as the number of cells that had entered the denuded area after 20 h. RPE cell proliferation was determined by [<sup>3</sup>H]-thymidine incorporation after incubation with IGF-1, IGF-2, and glucose for 24 h. Statistical analysis was performed with the paired Student’s t test. <i>Results:</i> Exposure of RPE cells to IGF-1, IGF-2, and glucose resulted in a significantly higher RPE cell migration as compared to the control medium (p < 0.008) with 21, 20, 17, and 9 cells/raster field, respectively. Additionally, IGF-1 (p = 0.004) and IGF-2 (p = 0.008) but not glucose caused a statistically significant stimulation of DNA synthesis with 761, 747, and 593 ccpm, respectively, as compared to the negative control (352 ccpm). <i>Conclusion:</i> This study indicates that IGF-1 and IGF-2 influence RPE cell migration and proliferation. This is further evidence that these factors are among those which have to be kept in mind when trying to modulate the development of diabetic eye diseases.
Intragenic breakpoint within RAD51L1 in a t(6;14)(p21.3;q24) of a pulmonary chondroid hamartoma
Authors: Blank C. , Schoenmakers E.F.P.M. , Rogalla P. , Huys E.H.L.P.G. , van Rijk A.A.F. , Drieschner N. , Bullerdiek J. 
Published: April 2003

Rearrangements involving chromosome region 14q23→q24 represent a main cytogenetic subgroup in a variety of benign solid tumors. Recently, in uterine leiomyomas containing the classical t(12;14)(q15;q23→q24), the primary chromosome 14 target gene was identified as the protein kinase-encoding gene RAD51L1. In this report we show that RAD51L1 is also involved in the frequently ocurring t(6;14) (p21;q23→q24) in pulmonary chondroid hamartomas.
Effect of Vegetarian Diet on Homocysteine Levels
Authors: Bissoli L. , Di Francesco V. , Ballarin A. , Mandragona R. , Trespidi R. , Brocco G. , Caruso B. , Bosello O. , Zamboni M. 
Published: April 2003

<i>Objective:</i> To compare fasting total plasma homocysteine (tHcy) levels in vegans, lacto-ovovegetarians and control subjects, and to evaluate the relationships between tHcy levels and nutritional variables in vegetarians. <i>Methods:</i> The study was conducted on 45 vegetarian subjects: 31 vegans (19 males, 12 females, mean age 45.8 ± 15.8 years); 14 lacto-ovovegetarians (6 males, 8 females, mean age 48.5 ± 14.5 years), and 29 control subjects (19 males, 10 females, mean age 43.4 ± 16.7 years). tHcy was evaluated by high-performance liquid chromatography. Serum vitamin B<sub>12</sub> and folate were analyzed by automated chemiluminescence systems. Clinical records, nutritional and anthropometric variables were collected for all vegetarian subjects. <i>Results:</i> tHcy was significantly higher in vegetarian subjects than in controls (23.9 ± 21.3 vs. 11.6 ± 4.9 µmol/l, p < 0.001). The prevalence of hyperhomocysteinemia was higher in vegetarians than in controls (53.3 vs. 10.3%, p < 0.001). Serum vitamin B<sub>12</sub> levels were lower in vegetarians than in control subjects (171.2 ± 73.6 vs. 265.0 ± 52.2 pmol/l, p < 0.01; normal range 220–740 pmol/l). In vegetarian subjects, significant inverse correlations were found between tHcy and serum vitamin B<sub>12</sub> levels (r = –0.776, p < 0.001) and between tHcy and serum folate levels (r = –0.340, p < 0.05). Positive correlations were found between tHcy and mean red cell volume (r = 0.44, p < 0.01) and between tHcy and fat-free mass (r = 0.36, p < 0.05). <i>Conclusion:</i> Vegetarian subjects presented significantly higher tHcy levels, higher prevalence of hyperhomocysteinemia, and lower serum vitamin B<sub>12</sub> levels than controls.
Bactericidal Effect of Combinations of Antibiotic and Antineoplastic Agents against <i>Staphylococcus aureus</i> and <i>Escherichia coli</i>
Authors: Nyhlén A. , Ljungberg B. , Nilsson-Ehle I. , Odenholt I. 
Published: April 2003

<i>Background:</i> The bactericidal effect of some antibiotic and antineoplastic agents commonly used in clinical practice was investigated to analyse whether the combinations act synergistically, have indifferent or antagonistic antibacterial effects compared to the effect of the antibiotics alone. <i>Methods:</i> The rate of killing of meropenem, ceftazidime and tobramycin was studied against six different strains of <i>Staphylococcus aureus</i> and <i>Escherichia coli</i>, and the results were compared to the rate of killing of the antibiotics in combination with the cytostatic drugs doxorubicin, etoposide and 5-fluorouracil (5-FU). <i>Results:</i> Tobramycin showed synergy against two strains of <i>S. aureus</i> after 3 h in the presence of 5-FU and against one strain of <i>S. aureus</i> in the presence of doxorubicin. Meropenem induced an antagonistic bactericidal effect against one isolate of <i>S. aureus</i> after 24 h. Ceftazidime expressed an indifferent bactericidal effect together with the cytostatic agents. The antineoplastic agents had no impact on the bacterial killing of any of the antibiotics against <i>E. coli. </i><i>Conclusions:</i> Tobramycin expressed a significantly better bactericidal effect against <i>S. aureus</i> after 3 h in the presence of doxorubicin and 5-FU than tobramycin alone. Meropenem expressed antagonism against one clinical strain of <i>S. aureus</i>, but the cytostatic drugs did not affect the killing of other strains tested. Ceftazidime expressed indifferent bactericidal activity together with the antineoplastic agents.
Left Ventricular Hypertrophy and Diastolic Dysfunction in Healthy Pregnant Women
Authors: Schannwell Christiana M. , Zimmermann Tobias , Schneppenheim Markus , Plehn Gunnar , Marx Roger , Strauer Bodo E. 
Published: April 2003

<i>Objective:</i> The purpose of this study was to examine which hemodynamic parameters change under the natural volume overload of pregnancy. <i>Study Design:</i> 46 healthy pregnant women were echocardiographically examined during the course of pregnancy. To evaluate left ventricular diastolic function, mitral inflow and pulmonary venous flow profiles were used. Fractional shortening and left ventricular muscle mass were calculated. <i>Results:</i> In the course of pregnancy the left ventricular muscle mass index increased (from 66 ± 6 to 96 ± 9 g/m<sup>2</sup>), fractional shortening decreased (from 38 ± 4 to 32 ± 6%) and a disturbed diastolic relaxation pattern was documented. Eight weeks after delivery, all left ventricular systolic and diastolic functional parameters returned to normal values. <i>Conclusion:</i> The natural volume overload in pregnancy leads to a reversible ‘physiological’ left ventricular hypertrophy, a short-term decrease in systolic function and a significant change in left ventricular diastolic function.
Evidence of Different Profiles of Side Effects and Drug–Drug Interactions among the Quinolones _ The Pharmacokinetic Standpoint
Authors: Lode Hartmut 
Published: April 2003

Recent pharmacokinetic data, interaction profiles, and specific tolerance problems associated with the fluoroquinolones are reviewed. Oral absorption was highest for levofloxacin (99–100%), and 500 mg oral levofloxacin achieved a much higher initial concentration than either sparfloxacin (400 mg) or ciprofloxacin (500 mg, b.i.d.), with a slow drop in concentration over 24 h. The C<sub>max</sub> achieved after an oral 250-mg dose ranged from a low of 1.2 µg/ml/70 kg for ciprofloxacin, to 1.71 for gatifloxacin and 2.17 for moxifloxacin, to a high of 2.48 for levofloxacin (<i>p</i> < 0.01). Ciprofloxacin had the lowest AUC of 4.6 µg/ml/70 kg, gatifloxacin 15, levofloxacin 17.9, and moxifloxacin 19.7 µg/ml/70 kg (<i>p</i> < 0.01). All fluoroquinolones interact with multivalent cation-containing products and bioavailability is reduced by 50% when co-administered with iron compounds (ciprofloxacin and moxifloxacin are more affected than levofloxacin or gemifloxacin). The interaction between theophylline and fluoroquinolones is most marked with enoxacin, pefloxacin, and ciprofloxacin, with no such interaction reported for levofloxacin. Sparfloxacin is associated with cardiac manifestations of QTc prolongation and has a high phototoxicity potential. Moxifloxacin is currently under observation concerning QTc effects. Levofloxacin has no QTc prolongation and a very low phototoxic potential, making it one of the safest new fluoroquinolones.
Comparison of Cerebral Blood Flow Velocity as Measured in Preeclamptic, Healthy Pregnant, and Nonpregnant Women by Transcranial Doppler Sonography
Authors: Zatik János , Aranyosi János , Mihálka László , Páll Dénes , Major Tamás , Fülesdi Béla 
Published: April 2003

<i>Aim: </i>To test the hypothesis that the middle cerebral artery blood flow velocity (MCAV) is altered in preeclamptic pregnant women as compared with healthy pregnant and nonpregnant women. <i>Methods:</i> Preeclamptic (n = 21) and healthy pregnant (n = 17) as well as healthy nonpregnant (n = 29) women underwent transcranial Doppler MCAV measurements. The mean MCAV values were compared between the different groups. Anova combined with Bonferroni correction was used for statistical analysis. <i>Results:</i> The MCAV was significantly higher in nonpregnant women (mean ± SE 73.0 ± 2.12 cm/s) as compared with healthy pregnant women (67.0 ± 1.8 cm/s, p = 0.0356). Preeclamptic women showed significantly higher MCAV values (83.5 ± 2.1 cm/s) as compared with nonpregnant females (73.0 ± 2.12 cm/s, p = 0.0014). Similar to nonpregnant women, healthy pregnant women showed lower MCAV values (67.0 ± 1.8 cm/s) as compared with preeclamptic women (83.5 ± 2.1 cm/s, p = 0.001). After Bonferroni correction the MCAV values in patients suffering from preeclampsia were still statistically significantly higher as compared with the two other groups. <i>Conclusions: </i>We detected increased resting MCAV values in pregnant women with preeclampsia. In our opinion, this finding refers to arteriolar dilation of the resistance vessels of the brain. Further studies are needed to prove altered vasoreactivity responses of the brain resistance arterioles in preeclampsia.
Bacterial Adhesiveness: Effects of the SH Metabolite of Erdosteine (Mucoactive Drug) plus Clarithromycin versus Clarithromycin Alone
Authors: Braga P.C. , Zuccotti T. , Dal Sasso M. 
Published: April 2003

After metabolization, erdosteine (a mucoactive drug) produces an active metabolite (Met I) with an SH group that is capable of opening disulphide bonds, including those of pilin, a protein of bacterial fimbriae. This induces stereochemical conformational changes that interfere with the binding of bacterial adhesins (fimbriae) to receptors on eukaryotic cells. At subinhibitory concentrations, the macrolide clarithromycin inhibits the expression of adhesins on bacterial cell surfaces. The addition of 5 and 10 µg/ml of Met I to 1/8, 1/16 and 1/32 MIC of clarithromycin potentiated the inhibition of <i>Staphylococcus aureus</i> adhesiveness to human mucosal cells in comparison with the antibiotic alone. This finding opens up a new possibility of interfering with bacterial adhesiveness and its resulting pathogenicity not only by using antibiotics but also by means of their combination with agents devoid of antibacterial activity.
MRI of Blood Volume and Cellular Uptake of Superparamagnetic Iron in an Animal Model of Choroidal Melanoma
Authors: Krause Matthias , Kwong Kenneth K. , Xiong Jing , Gragoudas Evangelos S. , Young Lucy H.Y. 
Published: April 2003

Functional magnetic resonance imaging (MRI), using monocrystalline iron oxide nanoparticles (MION) as a new intravascular contrast agent, was adapted for a rabbit model of pigmented choroidal melanoma. Three-dimensionally spoiled gradient recalled sequences were used for the quantitative assessment of blood volume and cellular uptake. In all ocular tissues studied, MION reduced the T<sub>2</sub>-weighted signal intensity within 0.5 h and at 24 h (both p < 0.05) after the injection. In individual tumors, MION reduced the T<sub>2</sub>-weighted signal intensity by 46–78% within 0.5 h and by 24–48% at 24 h. In addition, MION increased the T<sub>1</sub>-weighted signal intensity in all tissues. T<sub>2</sub> yielded a higher sensitivity than T<sub>1</sub>-weighted images. Functional MRI with MION is a noninvasive technique with regard to the eye, permitting measurement of blood volume and cellular uptake of the contrast agent. Further study is necessary to determine the feasibility of this technique for the tumor diagnosis and evaluation of tumor viability following treatments.
Remineralization of Advanced Root Dentin Lesions in vitro
Authors: Mukai Y. , ten Cate J.M. 
Published: April 2003

The possibility for remineralization of advanced root dentin lesions was investigated in vitro. Lesions were produced in acidic buffer solution with 0.1 and 0.5 ppm fluoride, for 3 and 5 weeks, respectively, using a single-section model. Next, the sections were immersed in a remineralization solution containing 0.1 ppm F (as NaF) for 20 weeks. Microradiographs were made after each 4-week-period. The lesions were around 500 µm deep, with mineral loss values between 11,000 and 18,000 vol%·µm. After 20 weeks of remineralization, the absolute amounts of deposited mineral ranged from 7,500 to 10,000 vol%·µm, corresponding to a repair between 50 and 85%. Lesion depth was, on average, reduced by 199 µm. This was not significantly different (at p < 0.05) between the four experimental groups. This study showed that remineralization of advanced dentinal lesions is possible in spite of the virtual absence of mineral in the lesion body after demineralization. The surface layer of the lesion was the preferred site for mineral deposition until mineral content values reached those of sound dentine. The mineral content in the lesion body increased with time, at a rate reflecting the initial severity of the lesion. We conclude that a remineralized surface layer does not inhibit transport of mineral ions to the body and that the remineralization in the lesion body reflected the number of sites for crystal growth.
Risk Factor Analysis for Long-Term Tunneled Dialysis Catheter-Related Bacteremias
Authors: Jean G. , Charra B. , Chazot C. , Vanel T. , Terrat J.C. , Hurot J.M. , Laurent G. 
Published: April 2003

Infection, mainly related to vascular access, is one of the main causes of morbidity and a preventable cause of death in hemodialysis patients. From January 1994 to April 1998 we conducted a prospective study to assess the incidence and risk factors of catheter-related bacteremia. One hundred and twenty-nine tunneled dual-lumen hemodialysis catheters were inserted percutaneously into the internal jugular vein in 89 patients. Bacteremia (n = 56) occurred at least once with 37 (29%) of the catheters (an incidence of 1.1/1,000 catheter-days); local infection (n = 45, 1/1,000 catheter-days) was associated with bacteremia in 18 cases. Death in 1 case was directly related to <i>Staphylococcus aureus</i> (SA) septic shock, and septicemia contributed to deaths in 2 additional cases. Catheters were removed in 48% of the bacteremic episodes. Treatment comprised intravenous double antimicrobial therapy for 15–20 days. Bacteriological data of bacteremia showed 55% involvement of SA. Nasal carriage of SA was observed in 35% of the patients with catheters. Bacteremic catheters were more frequently observed in patients with diabetes mellitus (p = 0.03), peripheral atherosclerosis (p = 0.001), a previous history of bacteremia (p = 0.05), nasal carriage of SA (p = 0.0001), longer catheter survival time (p = 0.001), higher total intravenous iron dose (p = 0.001), more frequent urokinase catheter infusion (p < 0.01), and local infection (p < 0.001) compared with non-bacteremic catheters. Monovariate survival analysis showed that significant initial risk factors for bacteremia were nasal carriage of SA (p = 0.00001), previous bacteremia (p = 0.0001), peripheral atherosclerosis (p = 0.005), and diabetes (p = 0.04). This study confirms the relatively high incidence of bacteremia with tunneled double-lumen silicone catheters and its potential complications. Possible preventive actions are discussed according to the risk factors.