bluuebunny/crossref_metadata_2025_split huggingface dataset:
Broadly Tunable Femtosecond Sources in the Mid-Infrared and Two-Wavelength Ultrafast Spectroscopy of Holes in GaAs
Authors: Tang C. L. , Burr K. C. , Ganikhanov F. Sh. 
Published: July 2003

The recent development of periodically poled lithium niobate (PPLN) has led to a variety of highly efficient and compact all-solid-state nonlinear optical devices. Of particular interest are the optical parametric oscillators. We have most recently demonstrated for the first time a highly efficient broadly tunable femtosecond optical parametric oscillator (fs OPO) using PPLN. The threshold for oscillation of the PPLN fs OPO is remarkably low, on the order of 50 mW. As a result, it is now possible to use a diode-pumped and frequency-doubled Nd:YVO 4 laser, rather than an Ar-ion laser, as the pump source for the mode-locked Ti:sapphire laser for pumping the fs OPO. Such an OPO can operate from approximately 1 μm to 5.4 μm. Femtosecond sources have been used in a variety of experiments to study the dynamics of hot carriers in semiconductors. Because of the limited available wavelength range of earlier femtosecond sources, most such studies have been limited to electron dynamics in the conduction band of III–V compounds such as GaAs. With the extended tuning range of the recently developed fs OPO's, it is now possible to study a much wider variety of materials and transitions. We have recently obtained preliminary results on the ultrafast dynamics of holes in GaAs using two-wavelength tunable femtosecond spectroscopy, by pumping the valence-to-conduction band transition at approximately 800 nm and simultaneously probing the transitions between the split-off band and the perturbed heavy-hole band at approximately 3 μm. These recent results are summarized and discussed briefly.
Effect of Linezolid on the Phagocytic Functions of Human Polymorphonuclear Leukocytes
Authors: Ballesta Sofía , Pascual Álvaro , García Isabel , Perea Evelio J. 
Published: July 2003

The effect of linezolid on the phagocytic and bactericidal functions of human polymorphonuclear neutrophils (PMN) against gram-positive cocci was evaluated. Preincubation (30 min; 37°C) of PMN with different concentrations of linezolid (2, 10 and 20 mg/l) did not significantly affect the phagocytosis of either <i>Staphylococcus aureus</i> (methicillin susceptible and resistant) or <i>Enterococcus faecalis</i> (vancomycin susceptible and resistant). Overnight exposure of vancomycin-resistant <i>E. faecalis</i> to 1/4 minimum inhibitory concentrations (MIC) of linezolid slightly increased phagocytosis by PMN. Preincubation of the other three strains with 1/4 MIC of linezolid did not affect phagocytosis by these cells. Preincubation of PMN (30 min; 37°C) using different extracellular concentrations of linezolid (2, 10 and 20 mg/l) did not affect their production of either superoxide or hydrogen peroxide radicals. In conclusion, linezolid did not affect the phagocytic and bactericidal functions of human PMN.
The Penetration of Moxifloxacin into the Pancreas of Male Rats in Experimental Acute Necrotizing Pancreatitis
Authors: Wacke Rainer , Park Sora , Mundkowski Ralf G. , Block Norma , Kuhn-Thiel Alexandra , Drewelow Bernd 
Published: July 2003

Infectious complications of acute necrotizing pancreatitis (ANP) determine the extent of multiorgan failure and account for 80% of deaths. Prophylactic use of antibiotics can reduce the incidence of these complications. However, the actual indication as well as choice of drug remains a controversial matter. We examined the penetration of moxifloxacin, a new broad-spectrum fluoroquinolone, in healthy and inflamed pancreatic tissue in rats after inducing ANP. The concentration of moxifloxacin in pancreatic tissue and serum was determined 10, 30, 60 and 240 min after the administration of moxifloxacin (5 mg/kg, i.v.). Mean serum concentrations 10 min after administration in rats with ANP were 1,886 ng/ml versus 1,805 ng/ml in healthy controls, and these values decreased to 350 versus 222 ng/ml, respectively, after 240 min. Corresponding concentrations in pancreatic tissue were in the mean 2–3 times higher.
Comparative in vitro Activity of Three Fluoroquinolones against Clinical Isolates by E Test
Authors: Madhusudhan Kunapuli T. , Counts Carolyn , Lody Cecilia , Carter Ophelia , Dodson Sarah , Ojha Neelam 
Published: July 2003

The in vitro susceptibility of levofloxacin, ciprofloxacin and moxifloxacin against several gram-positive and gram-negative clinical isolates was tested by E test. We found that the MIC<sub>50</sub> and MIC<sub>90</sub> values against all members of the Enterobacteriaceae family except <i>Serratia</i> were <0.5 mg/l for ciprofloxacin and levofloxacin (MIC range 0.006–32 mg/l) based on the in vitro susceptibility data. The susceptibility rates for ciprofloxacin and levofloxacin were more than 85% for <i>Escherichia coli, Citrobacter, Enterobacter cloacae, Enterobacter aerogenes</i> and <i>Klebsiella pneumoniae,</i> although <i>Serratia</i> and <i>Acinetobacter</i> exhibited more or less similar susceptibility rates (about 80%). <i>Pseudomonas aeruginosa</i> demonstrated significant resistance to fluoroquinolones (MIC<sub>90</sub> >32 mg/l) and decreased bactericidal rates (<65%) to levofloxacin and ciprofloxacin. Respiratory pathogens such as <i>Streptococcus pneumoniae</i> and <i>Haemophilus influenzae</i> were highly susceptible (100%) to levofloxacin and moxifloxacin. The ineffectiveness of fluoroquinolones for treating coagulase-positive <i>Staphylococcus aureus</i> was demonstrated by poor in vitro susceptibility rates with levofloxacin (52%) and moxifloxacin (57%). Coagulase-negative staphylococci demonstrated significantly decreased bactericidal rates to levofloxacin (21%), while the in vitro susceptibility to moxifloxacin was higher (66%) than that to levofloxacin. We propose that the beneficial effect of inclusion of any of these three fluoroquinolones in treating <i>Enterococcus</i> infections is marginal, as demonstrated by significantly reduced susceptibility rates (<32%). These data demonstrate the utility of fluoroquinoles to treat several gram-negative bacterial infections (with the exception of <i>Acinetobacter</i> and <i>P. aeruginosa)</i>, as well as <i>S. pneumoniae</i> and <i>H. influenzae.</i>
Antimicrobials as Potential Adjunctive Agents in the Treatment of Biofilm Infection with <i>Staphylococcus epidermidis</i>
Authors: Peck Kyong Ran , Kim Shin Woo , Jung Sook-In , Kim Yeon-Sook , Oh Won Sup , Lee Ji Young , Jin Joung Hwa , Kim Sungmin , Song Jae-Hoon , Kobayashi Hiroyuki 
Published: July 2003

<i>Background:</i> This study was performed to evaluate the interaction of erythromycin or rifampin with vancomycin against <i>Staphylococcus epidermidis</i> biofilms. <i>Methods:</i> Biofilm-forming <i>S. epidermidis</i> strains (ATCC 35983, 35984) and polyurethane (PU) sheets were incubated for the formation of bacterial biofilms. Biofilms on PU sheets were treated with various antibiotic regimens. The number of viable bacteria on the sheets was counted. <i>Results:</i> While erythromycin or vancomycin alone did not significantly reduce the biofilm bacterial concentration, the combination of vancomycin and erythromycin resulted in a clear reduction in bacterial concentration compared with the single agents. Rifampin was the most active single agent against biofilm-forming <i>S. epidermidis</i>, while the combination of rifampin and vancomycin showed further reduction in bacterial concentration. <i>Conclusions:</i> These data suggest that the combination of erythromycin or rifampin and vancomycin is more effective than vancomycin alone in the treatment of biofilm infections caused by biofilm-forming <i>S. epidermidis</i>.
Combination Chemotherapy with Irinotecan and Ifosfamide as Second-Line Treatment of Refractory or Sensitive Relapsed Small Cell Lung Cancer: A Phase II Study
Authors: Ichiki Masao , Gohara Rumi , Rikimaru Toru , Kitajima Takao , Fujiki Rei , Shimada Akiko , Aizawa Hisamichi 
Published: July 2003

This phase II study was conducted to investigate the efficacy and safety of irinotecan (CPT-11) and ifosfamide as second-line chemotherapy for relapsed small cell lung cancer (SCLC). Eligibility criteria included histologically or cytologically confirmed SCLC, prior chemotherapy including platinum + etoposide, and measurable or evaluable disease. CPT-11 (80 mg/m<sup>2</sup>) was administered intravenously on days 1, 8 and 15, while ifosfamide (1.5 g/m<sup>2</sup>) was given on days 1 through 3 every 4 weeks. Thirty-four patients (29 men) with a median age of 69 years (range 42–77) and a median Eastern Cooperative Oncology Group (ECOG) performance status of 1 (range 0–2) were enrolled. The response rate was 52.9% (95% confidence interval: 29.8–64.9%) with 2 complete responses and 16 partial responses. Our analyses of prognostic factors showed risk factors assessed before receiving second-line chemotherapy, which were the number of metastatic sites, performance status and the type of relapse. WHO grade 3–4 neutropenia was recorded in 52.9% of the patients, grade 3 diarrhea in 5.9%. The combination of CPT-11 and ifosfamide demonstrated clinical efficacy in relapsed SCLC with a favorable toxicity profile, particularly for performance status 0–1 and sensitive cases with only one metastatic site.
Downregulation of Superoxide Dismutase Activity and Gene Expression in Cultured Rat Brain Astrocytes after Incubation with Vitamin C
Authors: Kao Pai-Feng , Lee Wen-Sen , Liu Ju-Chi , Chan Paul , Tsai Jen-Chen , Hsu Yung-Ho , Chang Wen-Yin , Cheng Tzu-Hurng , Liao Shue-Sen 
Published: July 2003

Reactive oxygen species have been linked with neuropathological changes in the central nervous system. Epidemiological studies supported the beneficial effect of supplementation of antioxidants. Superoxide dismutase (SOD) is an endogenous enzyme which can scavenge reactive oxygen species. This study investigated the effect of supplementation with ascorbic acid (vitamin C) on the changes of SOD in cultured neurological cells. Rat brain astrocytes (RBA-1 cells) were incubated with vitamin C and divided into four groups: a control group (without vitamin C) and three treatment groups with vitamin C at 40, 80, and 160 µmol/l. After short-term (2 days) and long-term (7 days) incubation, SOD activity, SOD mRNA level by Northern blotting, and SOD protein amounts by Western blotting were measured. After 2 days of incubation, vitamin C resulted in a decrease in the activity of SOD in a concentration-dependent manner (Mn-SOD from 14.8 ± 1.2 to 13.2 ± 0.5 U/mg protein and Cu/Zn-SOD from 64.8 ± 1.2 to 51.7 ± 0.9 U/mg protein; p < 0.05), and vitamin C also attenuated the Cu/Zn-SOD mRNA level from 100 to 86.3 ± 6.7%; p < 0.01), whereas the protein amounts of these two SODs remained unchanged. After 7 days of incubation with vitamin C, the SOD activity of RBA-1 cells decreased significantly (Mn-SOD from 14.9 ± 0.3 to 11.8 ± 0.3 U/mg protein and Cu/Zn SOD from 61.8 ± 1.8 to 54.6 ± 0.9 U/mg protein; p < 0.01), and the mRNA level was also attenuated (Mn-SOD from 100 to 86.8 ± 8.7% and Cu/Zn-SOD from 100 to 84.7 ± 4.8%; p < 0.01). These results suggest that 2 and 7 days of incubation with relatively high concentrations of vitamin C may downregulate activity and gene expression of SOD in cultured RBA-1 cells.
Effect of Endothelin on Bladder Contraction: Potential Role in Bladder Hyperactivity
Authors: Westfall Timothy D. , McCafferty Gerald P. , Pullen Mark , Ventre Jessica , Eybye Marianne , Jugus Malcolm J. , Brooks Stuart A. , Hieble J. Paul , Brooks David P. 
Published: July 2003

In the present study, we demonstrate that the intravenous infusion of endothelin-1 (3 and 10 ng/kg/min) causes a decrease in the mean micturition volume of rats in addition to an increase in mean arterial pressure. These effects are blocked by both the ET<sub>A</sub>/ET<sub>B</sub>-non-selective and the ET<sub>A</sub>-selective endothelin antagonists SB 217242 and SB 247083 respectively (both 30 mg/kg). However, it was also observed that the ET<sub>B</sub>-selective agonist sarafotoxin 6c (3 and 10 ng/kg/min) had similar effects on both mean arterial pressure and micturition volume. Initial experiments indicated that spontaneously hypertensive rats have a much lower mean micturition volume than normal rats. Binding studies comparing the total number and ratio of ET<sub>A</sub>/ET<sub>B</sub> receptors in spontaneously hypertensive, Wister-Kyoto and Sprague-Dawley rats revealed no significant differences in receptor expression. However, the magnitude of the response to endothelin-1 was greater in spontaneously hypertensive versus normal rats.
Roles of Reactive Oxygen Species, NF-κB, and Peroxiredoxins in Glycochenodeoxycholic Acid-Induced Rat Hepatocytes Death
Authors: Chu Sang Hui , Lee-Kang Jihee , Lee Kweon-haeng , Lee Kyungeun 
Published: July 2003

The aim of this study was to determine the roles of reactive oxygen species (ROS), NF-ĸB and antioxidants in glycochenodeoxycholic acid (GCDC, 0–400 µmol/l, 0.5– 3 h)-induced hepatocytes death. The differential uptake of ethidium bromide and acridine orange revealed that apoptotic death occurred dose-dependently in GCDC-treated hepatocytes whereas necrotic death was prominent especially at higher GCDC concentrations (≧200 µmol/l). ROS generation measured fluorometrically either by a confocal laser microscope or by a microplate fluorescence reader was increased dose-dependently. The dose-dependent NF-ĸB activation with the significant IĸB-α decrease preceded both hepatocyte cell death and the alteration of antioxidant enzymes. The Cu/Zn-SOD level among several antioxidants, we checked, remained unchanged. In contrast, the catalase level and its enzymatic activity were markedly decreased only at 400 µmol/l. The Prx I and Prx II, newly defined antioxidant enzymes reducing H<sub>2</sub>O<sub>2</sub> levels were decreased at the 200 and 400 µmol/l. These observations point to ROS generation in the GCDC-treated hepatocyte as the proximate event that triggers NF-ĸB activation, IĸB-α proteolysis, Prx depletion, and finally cell death. And oxidative stress may be more related to necrotic cell death in GCDC-treated hepatocytes.
Effects of Endogenous Histamine on Seizure Development of Pentylenetetrazole-Induced Kindling in Rats
Authors: Zhang Li-San , Chen Zhong , Huang Yu-Wen , Hu Wei-Wei , Wei Er-Qing , Yanai Kazuhiko 
Published: July 2003

This study was performed to investigate whether or not endogenous histamine can protect seizure development of pentylenetetrazole (PTZ)-induced kindling in rats. An intracerebroventricular (i.c.v.) injection with clobenpropit (5 and 10 µg), a representative H<sub>3</sub>-antagonist, significantly prolonged the onset of kindling and inhibited the seizure stages in a dose-dependent manner. Its action was significantly reversed by both immepip (2 µg, i.c.v.), an H<sub>3</sub>-agonist, and α-fluoromethylhistidine (α-FMH, 10 µg, i.c.v.), a selective histidine decarboxylase inhibitor. α-FMH (20 µg, i.c.v.) and pyrilamine (1 and 5 mg/kg i.p.), a classical H<sub>1</sub>-antagonist, markedly augmented the severity of seizure development of PTZ-induced kindling. Therefore, these results indicate that brain endogenous histamine plays a certain protective role on seizure development of PTZ-induced kindling in rats, and that its protective roles are mediated by H<sub>1</sub>-receptors.
Effects of Camonagrel, a Selective Inhibitor of Platelet Thromboxane Synthase, on the Platelet-Subendothelium Interaction
Authors: Villalobos M.A. , De La Cruz J.P. , Escalante R. , Arrebola M.M. , Guerrero A. , Sánchez de la Cuesta F. 
Published: July 2003

The aim of this study was to compare the effects of a new thromboxane synthase inhibitor, camonagrel, on platelet aggregation and platelet-subendothelium interaction under flow conditions, in comparison with a standard thromboxane synthase inhibitor (dazoxiben) and a cyclooxygenase inhibitor (acetylsalicylic acid). With respect to platelet aggregation in whole blood, the 50% inhibitory concentrations (IC<sub>50</sub>) of camonagrel were between 318 and 797 µmol/l after induction with collagen and adenosine 5′-diphosphate, respectively. For inhibition of thromboxane B<sub>2</sub> synthesis, the IC<sub>50</sub> values were 868 ± 68 µmol/l; prostaglandin E<sub>2</sub> was inhibited only by acetylsalicylic acid (IC<sub>50</sub> for camonagrel >2,000 µmol/l), and the leukocyte 6-keto-PGF<sub>1α</sub> level was increased by camonagrel. The greatest reduction in percentage subendothelial surface occupied by platelets (mainly in the thrombi) after blood perfusion was seen after incubation with camonagrel in the range of concentrations that inhibited collagen-induced platelet aggregation. In conclusion, camonagrel reduced platelet-subendothelium interaction under flow conditions, showing this effect in a range of concentrations lower than in inhibition of platelet aggregation.
Nutritionally Regulated Hormonal Factors in Prolonged Postnatal Growth Retardation and Its Associated Adverse Neurodevelopmental Outcome in Extreme Prematurity
Authors: Yeung Melinda Y. , Smyth John P. 
Published: July 2003

Recent published data show that at hospital discharge, most infants born at <30 weeks of gestation would not achieve the median birth weight of the reference fetus at the same postconceptional age, and many would be less than the 10th centile. Estimating from the current recommendations of calorie and protein intakes, these infants accrue large deficits in intakes of protein and calorie during the first weeks of life. Postnatal growth retardation over a prolonged period of time is related to neurodevelopmental delays. While a total energy intake of 120 kcal/kg/day has generally been considered adequate, protein requirement in low gestation infants remains a matter for debate. Increasing the dietary protein:calorie ratio has previously been proposed as a strategy to enhance growth and to achieve a body composition similar to that of the reference fetus. Previous study data reveal that serum insulin-like growth factor I (IGF-I) concentration is positively correlated with protein intake, and nitrogen retention, in turn, is positively correlated with serum IGF-I concentration. Remarkably, elevated serum growth hormone but low serum IGF-I concentrations have been reported in low gestation infants and in infants with intrauterine growth retardation, suggesting IGF-I being a nutritionally regulated hormonal factor in the postnatal growth retardation. As neurodevelopment in extreme prematurity is likely affected by multiple factors, we hypothesize that a combined strategy of the previously proposed hormonal supplement with hydrocortisone and tri-iodothyronine together with increased dietary protein intake (progressively increasing from 1.5 g/kg/day intravenously administered amino acids immediately after birth, then 3.6 g/100 kcal at &#8776;125 kcal/kg/day when enterally fed till the infant reaches a body weight of ≧1.8 kg and at ≧50th centile weight of the reference fetus at the same postconceptional age) would likely be synergistic and more effective in improving neurodevelopmental outcome.
Effects of Antenatal Antibiotics on the Incidence and Bacteriological Profile of Early-Onset Neonatal Sepsis
Authors: Laugel V. , Kuhn P. , Beladdale J. , Donato L. , Escande B. , Astruc D. , Messer J. 
Published: July 2003

<i>Background:</i> Recommendations for the use of antenatal antibiotics have been widely implemented in the past few years, notably to prevent group B streptococcal disease or to prolong pregnancy in the case of preterm premature rupture of the membranes. <i>Objectives:</i> We designed a retrospective study to assess the potential effects of this increasing use of antibiotics on the incidence and bacteriological profile of early-onset neonatal sepsis (EONS). <i>Methods:</i> All neonates referred to our department for suspected EONS from January 1 1995 through December 31 1999 were included. Antenatal antibiotic exposure together with clinical and microbiological data from the neonatal period were gathered and analyzed on a yearly basis. <i>Results:</i> Of the 485 newborns who met the inclusion criteria, there were 101 cases of culture-confirmed sepsis; 339 cases of suspected sepsis and 69 cases of confirmed sepsis involved children born in the hospital, among a total of 16,627 live births registered in our center over the study period. The overall incidence of EONS dropped from 6.8 to 0.6/1,000 births between 1995 and 1999 (p < 0.001), but the rate of group B streptococcal infection decreased much more rapidly than that of non-group B streptococcal infection. We observed a trend towards the emergence of ampicillin-resistant <i>Escherichia coli</i> strains, which were isolated in seven cases. Among <i>E. coli</i> infections, ampicillin resistance was statistically linked with antenatal antibiotic use (p = 0.025). We also delineated several risk factors associated with these infections. <i>Conclusion:</i> In our center, antenatal antibiotic treatment was effective in reducing the incidence of EONS, but this benefit may come at the cost of favoring the emergence of ampicillin-resistant organisms causing severe neonatal infections. Antenatal and postnatal antibiotic treatment strategies should take this adverse effect into account.
Maternal Diet with Diverse Omega–6/Omega–3 Ratio Affects the Brain Docosahexaenoic Acid Content of Growing Chickens
Authors: Ajuyah A.O. , Wang Y. , Sunwoo H. , Cherian G. , Sim J.S. 
Published: July 2003

Eggs with diverse ω–6/ω–3 ratio produced by feeding breeder hens a wheat-soybean meal-basal diet containing 5% (wt/wt) sunflower oil (Hω6), 5% fish oil (Hω3) or 2.5% sunflower oil plus 2.5% fish oil (Mω3ω6) were incubated. The hatched chicks were fed a docosahexaenoic acid (DHA)-deficient diet up to 6 weeks of age. The fatty acid composition of chick brain was determined on 0, 2, 4 and 6 weeks and brain weight was taken on day 0 and day 42. The ω–6/ω–3 ratios were 37.12, 4.21 and 0.98 for the maternal diet; 28.36, 2.83 and 0.89 for the egg yolk; 1.94, 0.48 and 0.18 for hatched chick brain (p < 0.05). At 2 weeks of age, the ω–6/ω–3 ratios were 1.88, 0.81 and 0.60 for chicks hatched from hens fed Hω6, Mω3ω6 and Hω3 diets, respectively. The brain DHA contents at 0 and 2 weeks of age were Hω3 > Mω3ω6 < Hω6 (p < 0.05) and at 4 and 6 weeks of age Hω3 = Mω3ω6 > Hω6. Dietary C18:3ω3 in the starter and finisher diet did not increase brain DHA (p > 0.05). The significant increase in the content of C22:5ω3 at 6 weeks of age in group 1 birds with a concomitant reduction in DHA suggests a weak delta-4 desaturation but an effective delta-6 and delta-5 desaturation similar to human infants. Considering the role of DHA in early brain development and growth, the maternal supply of DHA during growth might be of importance when fed a DHA-deficient neonatal diet.