bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absorption and fluorescence study of the interaction between (2-hydroxy-benzimido)ethyl-n-hexylselenide and bovine serum albumin
Authors: Chang-Ying Yang , Yi Liu , Jun Wu , Ran Li , Yan-Jun Hu , Song-Sheng Qu 
Published: August 2004

Abstract
The binding of Schiff base selenide, (2-hydroxy-benzimido)ethyl-n-hexylselenide, to bovine serum albumin (BSA) was studied using fluorescence spectroscopy. The measurement was performed in Tris-HCl buffer aqueous medium at pH 7.4. Stern-Volmer graphs were plotted and quenching constants were estimated. The quenching constant at 303 K was (1.639 ± 0.046) × 1013 L mol−1 s−1. Decreased quenching was observed as temperature increased, but at the temperature range of 303–313 K, the association of Schiff base selenide to BSA was not significantly different. The static quenching presented in the system of Schiff base selenide and BSA. A complex was possibly formed between Schiff base selenide and BSA, which was responsible for the quenching of the fluorescence of BSA. This fact was also confirmed by differences in the absorption spectra of BSA before and after Schiff base selenide addition. The hydrophobic interaction was found to play a main role in the binding according to the thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) of reaction. Schiff base selenide most likely binds to the hydrophobic pockets within sub domain IIA of BSA, which can be proved by competition experiments for sodium dodecyl sulfate. By constant-wavelength synchronous fluorescence spectra, the influence of (2-hydroxy-benzimido)-ethyl-n-hexylselenide on the surrounding environment of tyrosine and tryptophan residues in BSA was also investigated. The red shift of the fluorescence peak of tryptophan residues indicated that the hydrophobic amino acid structure surrounding tryptophan residues in BSA collapsed slightly after the addition of (2-hydroxy-benzimido)ethyl-n-hexylselenide.
Analysis of the interaction of substituted coumarins with the DPPH free radical by means of multivariate statistics
Authors: Vrakas Demetris , Hadjipavlou-Litina Dimitra , Tsantili-Kakoulidou Anna 
Published: August 2004

Abstract
The interaction of some substituted coumarin derivatives with the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was analysed by means of multivariate statistics using a variety of molecular descriptors. The compounds contain a conjugated double bond system, which was considered to be an essential structural characteristic for the free-radical scavenging activity. Partial least-square analysis led to an adequate two-component model based on bulk descriptors and the electronic properties concerning atoms involved or next to the double-bond system.
Efficacy of chitosan microspheres for controlled intra-articular delivery of celecoxib in inflamed joints
Authors: Thakkar Hetal , Sharma R K , Mishra A K , Chuttani Krishna , Murthy R S R 
Published: August 2004

AbstractThe use of polymeric carriers in formulations of therapeutic drug delivery systems has gained widespread application, due to their advantage of being biodegradable and biocompatible. In this study, we aimed to prepare celecoxib-loaded chitosan microspheres for intra-articular administration and to compare the retention of the celecoxib solution and chitosan microspheres in the joint cavity. The microspheres were characterized for entrapment efficiency, particle size and surface morphology by scanning electron microscopy. In-vitro drug release studies of microspheres revealed that the microspheres are able to control the release of celecoxib over a period of 96 h. Biodistribution studies of celecoxib and chitosan microspheres were performed by radiolabelling with 99mTc and injecting intra-articularly in rats. The study indicated that following intra-articular administration the distribution of the drug to the organs, like liver and spleen, is very rapid compared with that of the microspheres. Compared with the drug solution, a 10-fold increase in the concentration of the drug in the joint was observed 24 h post intra-articular injection (P &lt; 0.005) when drug was encapsulated in microspheres.
Fluorescein permeability and electrical resistance of human skin during low frequency ultrasound application
Authors: Cancel Limary M , Tarbell John M , Ben-Jebria Abdellaziz 
Published: August 2004

Abstract
Transdermal drug delivery offers an alternative to injections and oral medication but is limited by the low skin permeability of most drugs. The use of low-frequency ultrasound over long periods of time, typically over an hour, has been shown to enhance skin permeability, a phenomenon referred to as sonophoresis. In this study, we investigated the effects of short time sonication of human skin at 20 kHz and at variable intensities and duty cycles on the dynamics of fluorescein transport across the skin (permeability) as well as the changes in the skin's structural integrity (electrical resistance). We found that a short application of ultrasound enhanced the transport of fluorescein across human skin by a factor in the range of 2–9 for full thickness skin samples and by a factor in the range of 2–28 000 for heat-stripped stratum corneum samples (however, samples with very high (103) enhancement were likely to have been damaged by ultrasound). The electrical resistance of the skin decreased by an average of 20% for full thickness samples and 58% for stratum corneum samples. Increasing the duty cycle from 10 to 60% caused a significant increase in permeability enhancement from 2.3 to 9.1, and an increase in intensity from 8 to 23 mW cm2 induced a significant increase in permeability enhancement from 2 to 7.4, indicating a clear dependence of the permeability on both duty cycle and intensity. The increase in solute flux upon ultrasound exposure was immediate, demonstrating for the first time the fast response dynamics of sonophoretic enhancement. In addition, a quantitative analysis of the thermal and convective dispersion effects associated with ultrasound application showed that each contributes significantly to the overall permeability enhancement observed.
Cytotoxicity of 3,4-dihalogenated 2(5H)-furanones
Authors: Lattmann Eric , Kinchington Derek , Dunn Simon , Singh Harjit , Ayuko Washington O , Tisdale Michael J 
Published: August 2004

Abstract
Mucohalogen acids have been used for the preparation of a variety of 3,4-dihalogenated 2(5H)-furanones. In one synthetic step the carbamates 2a-c and the pseudoanhydrides 4a-e were prepared using isocyanates and acid anhydrides. A series of 5-alkoxylated 3,4-dichloro-2(5H)-furanones 5a-o have been synthesized with a wide range of lipophilicity, using the hydroxy-form of mucohalogen acids 1a and 1b. The 5-allyl-3,4-dichloro-2(5H)-furanone 5f was derived into the dihydro-isoxazol 6 and the oxirane 7. The methyl ester 5a was converted with ammonia into the tetramic acid chloride 11. The pseudo acid chloride 3 was reacted further into the bis aziridine 8. Reduction of the mucochloric acid 1a furnished the trichlorofuranone 3. The cytotoxicity of these simple and bis-cyclic butenolides have been evaluated in tissue culture on MAC13 and MAC16 cancer cell lines using the MTT cytotoxicity assay. The ester 5g, the acetate 4b and the carbamate 2b displayed a cytotoxicity in the low micromolar range. Further, an IC50 (50% inhibitory concentration) of 50 nM and 30 nM was determined for the epoxide 7 and the aziridine 8.
Oral delivery of spray dried PLGA/amifostine nanoparticles
Authors: Pamujula Sarala , Graves Richard A , Freeman Thomas , Srinivasan Venkataraman , Bostanian Levon A , Kishore Vimal , Mandal Tarun K 
Published: August 2004

Abstract
Amifostine (Ethyol, WR-2721) is a cytoprotective drug approved by the US Food & Drug Administration for intravenous administration in cancer patients receiving radiation therapy and certain forms of chemotherapy. The primary objective of this project was to develop orally active amifostine nanoparticles using spray drying technique. Two different nanoparticle formulations (Amifostine-PLGA (0.4:1.0 and 1.0:1.0)) were prepared using a Buchi B191 Mini Spray Dryer. A water-in-oil emulsion of amifostine and PLGA (RG 502) was spray dried using an airflow of 600 Lh−1 and input temperature of 55°C. A tissue distribution study in mice was conducted following oral administration of the formulation containing drug-polymer (0.4:1.0). The efficiency of encapsulation was 90% and 100%, respectively, for the two formulations while the median particle sizes were 257 and 240 nm, with 90% confidence between 182 and 417 nm. Since amifostine is metabolized to its active form, WR-1065, by intracellular alkaline phosphatase, the tissue levels of WR-1065 were measured, instead of WR-2721. WR-1065 was detected in significant amounts in all tissues, including bone marrow, jejunum and the kidneys, and there was some degree of selectivity in its distribution in various tissues. This work demonstrates the feasibility of developing an orally effective formulation of amifostine that can be used clinically.
A review of selected anti-tumour therapeutic agents and reasons for multidrug resistance occurrence
Authors: Sawicka M , Kalinowska M , Skierski J , Lewandowski W 
Published: August 2004

Abstract
It is assumed that proteins from the ABC family (i.e., glycoprotein P (Pgp)) and a multidrug resistance associated protein (MRP) play a main role in the occurrence of multidrug resistance (MDR) in tumour cells. Other factors that influence the rise of MDR are mechanisms connected with change in the effectiveness of the glutathione cycle and with decrease in expression of topoisomerases I and II. The aim of this review is to characterize drugs applied in anti-tumour therapy and to describe the present state of knowledge concerning the mechanisms of MDR occurrence, as well as the pharmacological agents applied in reducing this phenomenon.
Anticonvulsant Hypersensitivity Syndrome: Lymphocyte Toxicity Assay for the Confirmation of Diagnosis and Risk Assessment
Authors: Bavdekar Sandeep B , Muranjan Mamta N , Gogtay Nithya J , Kantharia Vishakha , Kshirsagar Nilima A 
Published: August 2004

OBJECTIVE To report a case of anticonvulsant hypersensitivity syndrome (AHS) precipitated by exposure to phenobarbital. Case Summary An 11-year-old girl receiving phenobarbital developed fever, exfoliative skin rash, mucous membrane lesions, alopecia, and hepatic inflammation. Investigations ruled out an infectious etiology; an adverse event following phenobarbital administration was considered. Applying the Naranjo probability scale for objective causality assessment showed the adverse reaction was probably due to phenobarbital. The diagnosis was confirmed by in vitro lymphocyte toxicity assay, which demonstrated increased cell death following exposure to phenobarbital, as well as other aromatic anticonvulsants and lamotrigine. DISCUSSION AHS is a rare, potentially fatal event with multisystem manifestations. It is reported following exposure to aromatic antiepileptics. The mechanism proposed for AHS is accumulation of toxic arene oxide metabolites due to a defect in epoxide hydrolase—mediated detoxification. Despite the difference in chemical structure of lamotrigine, in vitro susceptibility to AHS was demonstrated in our patient. CONCLUSIONS Although AHS is a rare event, it should be suspected in patients who develop unexplained systemic manifestations following exposure to aromatic antiepileptics. The potential of lamotrigine to cause AHS should be remembered when this drug is used in subjects who have developed AHS on exposure to phenobarbital and other first-line antiepileptic agents.
A Physiologically Based Model of Interaural Time Difference Discrimination
Authors: Hancock Kenneth E. , Delgutte Bertrand 
Published: August 2004

Interaural time difference (ITD) is a cue to the location of sounds containing low frequencies and is represented in the inferior colliculus (IC) by cells that respond maximally at a particular best delay (BD). Previous studies have demonstrated that single ITD-sensitive cells contain sufficient information in their discharge patterns to account for ITD acuity on the midline (ITD = 0). If ITD discrimination were based on the activity of the most sensitive cell available (“lower envelope hypothesis”), then ITD acuity should be relatively constant as a function of ITD. In response to broadband noise, however, the ITD acuity of human listeners degrades as ITD increases. To account for these results, we hypothesize that pooling of information across neurons is an essential component of ITD discrimination. This report describes a neural pooling model of ITD discrimination based on the response properties of ITD-sensitive cells in the IC of anesthetized cats.Rate versus ITD curves were fit with a cross-correlation model of ITD sensitivity, and the parameters were used to constrain a population model of ITD discrimination. The model accurately predicts ITD acuity as a function of ITD for broadband noise stimuli when responses are pooled across best frequency (BF). Furthermore, ITD tuning based solely on a system of internal delays is not sufficient to predict ITD acuity in response to 500 Hz tones, suggesting that acuity is likely refined by additional mechanisms. The physiological data confirms evidence from the guinea pig that BD varies systematically with BF, generalizing the observation across species.
Postnatal Management of Resolving Fetal Lung Lesions
Authors: Blau Hannah , Barak Asher , Karmazyn Boaz , Mussaffi Huda , Ben Ari Joseph , Schoenfeld Tommy , Aviram Micha , Vinograd Yitzchak , Lotem Yitzchak , Meizner Israel 
Published: August 2004

Objectives. Lung lesions are increasingly diagnosed since the advent of routine prenatal ultrasound. These lesions seem to involute in 15% to 30% of cases. Postnatal evaluation is frequently limited, particularly when repeated ultrasound or initial chest radiographs are normal. As careful follow-up or resection may be required, accurate diagnosis is essential. The objective of this study was to determine whether prenatal lung lesions that seem to resolve are still present when evaluated more closely.
Methods. We followed 24 cases of prenatally diagnosed lung lesions at our center, using repeated chest radiographs and chest computerized tomography (CT).
Results. Some lesions caused mild mediastinal shift, but none showed hydrops fetalis. In 7 cases, the last prenatal ultrasound was negative. In 15 cases, initial postnatal chest radiograph was normal and in only 4 of these, the lesion was seen on later chest radiographs. This apparently high rate of resolution was, however, misleading. In 22 of the 23 cases in which CT was performed, lung cysts or lobar overinflation was clearly demonstrated.
Conclusions. Apparent involution of lung lesions on serial prenatal ultrasounds or neonatal chest radiograph can be misleading. We strongly recommend repeated radiographs and chest CT for definitive diagnosis in all cases.
Long-Term Ophthalmic Outcome of Low Birth Weight Children With and Without Retinopathy of Prematurity
Authors: O’Connor Anna R. , Stephenson Terence , Johnson Ann , Tobin Michael J. , Moseley Merrick J. , Ratib Sonia , Ng Yin , Fielder Alistair R. 
Published: August 2004

Objective. A prospective study of retinopathy of prematurity (ROP) of 505 infants who weighed &lt;1701 g at birth was undertaken in the mid-1980s. This cohort was traced at 10 to 12 years of age to determine how low birth weight alone and ROP might influence their ophthalmic outcome.Methods. Outcome measures were 1) visual functions (visual acuity, contrast sensitivity, stereoacuity, perimetry, and color vision), 2) presence of strabismus, and 3), measurements of eye size and the dimensions of its components including refractive state. A total of 169 11-year-olds who were born at term were recruited as control subjects and examined under the same conditions.Results. A total of 448 of the original cohort were traced, and 254 consented to a further examination. Compared with the control group, the follow-up cohort differed significantly with reduced visual functions and increased incidence of both myopia and strabismus. Compared with published data, eye size was smaller in the low birth weight cohort. To summarize the ophthalmic data, we defined ophthalmic morbidity as visual acuity below 0.0 log units or the presence of strabismus, myopia, color vision defect, or visual field defect. The rate of ophthalmic morbidity was 50.8% (n = 129/254) in the study cohort compared with 19.5% (n = 33/169) in the control group. The highest rate of ophthalmic morbidity was associated with severe ROP (stages 3/4), although those with no ROP had a less favorable outcome than the control group.Conclusion. This study shows that low birth weight children are at increased risk of visual impairments compared with children who are born at full term. Visual impairments are associated with low birth weight per se and severe ROP. Regressed mild ROP is only a risk factor for strabismus. The functional significance of these deficits is largely unknown.
Multiple-Birth Infants at Higher Risk for Development of Deformational Plagiocephaly: II. Is One Twin at Greater Risk?
Authors: Littlefield Timothy R. , Kelly Kevin M. , Pomatto Jeanne K. , Beals Stephen P. 
Published: August 2004

Objective. In part 1 of this investigation, we demonstrated that children of multiple birth pregnancies are at higher risk for development of deformational plagiocephaly. In the current investigation, we explore whether certain prenatal and postnatal risk factors predispose one twin over the other by examining the occurrence and severity of plagiocephaly in both discordant (only 1 affected) and concordant (both affected) twin pairs.
Methods. Throughout 1999, we obtained detailed medical histories on 140 sets of twins who had presented for treatment at 1 of 9 treatment centers across the United States. The study cohort consisted of 46 concordant and 94 discordant twin pairs (a total of 280 study participants). Information about prenatal and postnatal history of each infant was obtained through detailed review of the children’s medical records as well as analysis of a patient database maintained on all infants who receive treatment. Follow-up interviews were performed to verify the information recorded and to obtain additional information about the child who had not received treatment (if appropriate) or use of reproductive assistance (fertility drugs, intracytoplasmic sperm injection, etc) that had not been previously recorded. Statistical analyses were performed to assess the effects of prenatal and postnatal risk factors (in utero position, in utero orientation, birth weight, neck involvement, sleeping position) with respect to which infant was affected in the discordant twin pairs and to which infant was more severely affected in the concordant twin pairs.
Results. Statistical analyses of both discordant and concordant twin pairs demonstrated that the lower in utero infant was significantly more likely to be affected (χ2 = 17.391). In addition, the more severely affected infant was significantly more likely to have some form of neck involvement (torticollis, neck tightness; χ2 = 46.380), as well as have been carried in a vertex position (χ2 = 7.408). Conversely, neither sleeping position nor gender was found to be associated with development of plagiocephaly.
Conclusions. The results of this investigation strongly support an in utero cause of plagiocephaly and demonstrate that intrauterine positioning may play a prominent role in determining both the occurrence and severity of deformational plagiocephaly in twins. These findings confirm that the lower in utero infant is at increased risk for the development of plagiocephaly, likely resulting from the more restrictive intrauterine environment encountered during the later part of the pregnancy.
Social Factors Associated With Prolonged Hospitalization Among Diabetic Children
Authors: Keenan Heather T. , Foster Carol M. , Bratton Susan L. 
Published: August 2004

Objective. To determine social factors associated with increased risk of hospital admission from diabetic ketoacidosis (DKA) or diabetic coma as well as risk of prolonged hospital stay.Methods. A cohort of all children (≤21 years) with type 1 diabetes mellitus (DM) in the National Inpatient Sample admitted for DKA or diabetic coma during 1996 or 1997 was conducted. Patients’ age, race, gender, and insurance coverage were identified. Length of stay and charges were examined; prolonged length of stay was defined as ≥7 days.Results. A total of 8443 children with a primary hospital diagnosis of DKA and 123 children with type 1 DM and coma were identified; 55% of the children were girls, 32% were nonwhite, 29% received Medicaid insurance, and 33% resided in areas of poverty. Children with prolonged hospital stay were significantly more likely to be of nonwhite race (odds ratio [OR]: 2.0; 95% confidence interval [CI]: 1.6–2.5), to receive Medicaid insurance (OR: 1.4; 95% CI: 1.1–1.7), to live in areas of poverty (OR: 1.3; 95% CI: 1.1–1.7), and to be of younger age.Conclusions. When compared with state census data, nonwhite and poor children were more likely to be admitted with complications of DM and to have significantly prolonged and expensive hospital stays. These children should be targeted for intensive diabetes education and outpatient medical support both to improve their health and potentially to decrease total health care costs.
Centers for Disease Control and Prevention 2000 Growth Charts for the United States: Improvements to the 1977 National Center for Health Statistics Version
Authors: Ogden Cynthia L. , Kuczmarski Robert J. , Flegal Katherine M. , Mei Zuguo , Guo Shumei , Wei Rong , Grummer-Strawn Laurence M. , Curtin Lester R. , Roche Alex F. , Johnson Clifford L. 
Published: August 2004

Objective. To present a clinical version of the 2000 Centers for Disease Control and Prevention (CDC) growth charts and to compare them with the previous version, the 1977 National Center for Health Statistics (NCHS) growth charts.Methods. The 2000 CDC percentile curves were developed in 2 stages. In the first stage, the empirical percentiles were smoothed by a variety of parametric and nonparametric procedures. To obtain corresponding percentiles and z scores, we approximated the smoothed percentiles using a modified LMS estimation procedure in the second stage. The charts include of a set of curves for infants, birth to 36 months of age, and a set for children and adolescents, 2 to 20 years of age.Results. The charts represent a cross-section of children who live in the United States; breastfed infants are represented on the basis of their distribution in the US population. The 2000 CDC growth charts more closely match the national distribution of birth weights than did the 1977 NCHS growth charts, and the disjunction between weight-for-length and weight-for-stature or length-for-age and stature-for-age found in the 1977 charts has been corrected. Moreover, the 2000 CDC growth charts can be used to obtain both percentiles and z scores. Finally, body mass index-for-age charts are available for children and adolescents 2 to 20 years of age.Conclusion. The 2000 CDC growth charts are recommended for use in the United States. Pediatric clinics should make the transition from the 1977 NCHS to the 2000 CDC charts for routine monitoring of growth in infants, children, and adolescents.