bluuebunny/crossref_metadata_2025_split huggingface dataset:
The support taken through walking aids during hemiplegic gait
Authors: Tyson S F 
Published: March 2004

Objective: To assess the effect of different aids on the amount of support hemiplegic subjects took from them. The relationship between the amount of support, severity of hemiplegia and walking ability were also assessed. Design: Hemiplegic subjects' gait and the amount of support they took from the aid were measured as they walked with a normal height stick, a high stick and a tripod. Subjects: Fifteen subjects with a hemiplegia of more than three months' duration who could walk independently were recruited. Outcome measures: Velocity, the gross function section of the Rivermead Motor Assessment, percentage bodyweight taken through the aid, the aid contact time, the placement of the aid, and the lateral shift of the pelvis when weight bearing were assessed. Results: No differences in the amount of support or walking ability were found with the different aids. There was a significant relationship between severity of hemiplegia and the percentage of bodyweight taken through the aid ( r = –0.67), between aid contact time and severity of hemiplegia (–0.53) and between aid contact time and walking ability (–0.53). No relationship between walking ability and other measures of the amount of support was found. Conclusions: Different types of aid did not influence the amount of support taken by hemiplegic subjects. These results contradict the beliefs of many neurological physiotherapists in Britain and the clinical implications are discussed.
Electrical stimulation of human tibialis anterior: (A) contractile properties are stable over a range of submaximal voltages; (B) high- and low-frequency fatigue are inducible and reliably assessable at submaximal voltages
Authors: Hanchard Nca , Williamson M , Caley R W , Cooper R G 
Published: March 2004

Objectives: To investigate the validity and reliability of submaximal voltage stimulation for assessing the ‘fresh’ contractile properties of human tibialis anterior muscle (TA) and the efficacy of such stimulation in inducing and assessing high- and low-frequency fatigue. Interventions: (A) Contractile properties of fresh TA were assessed in six normal volunteers using multifrequency stimulation trains (comprising 2 seconds at each of 10, 20 and 50 Hz, arranged contiguously) over a range of submaximal voltages. (B) On three separate occasions, fatigue was induced in the TA of 10 normal volunteers by means of a 3-minute unbroken sequence of the described multifrequency stimulation trains, delivered at a ‘standardized’ submaximal voltage. This fatiguing protocol was preceded by discrete multifrequency stimulation trains, at the same standardized voltage, but followed by discrete multifrequency trains delivered over a range of submaximal voltages (which included the standardized voltage). Outcome measures: In experiment A the 10:50 Hz and 20:50 Hz force ratios were analysed for between-voltages variability using coefficients of variation (CVs), and for trends using Friedman tests and post-hoc Wilcoxon tests. In experiment B low-frequency fatigue was detected using 10:50 Hz and 20:50 Hz force ratios derived from the discrete multifrequency trains. High-frequency fatigue was calculated from the decline in high-frequency force which occurred during the fatiguing protocol itself. Each parameter was assessed for between-days repeatability using CVs. Results: In experiment A the ‘fresh’ 10:50 Hz force ratio was clearly unreliable at voltages which generated <10% of maximal voluntary contractile force (MVC) (CV ≤29.7%), but was reasonably reliable at voltages which generated 20–30% of MVC (CV ≤11.5%; p = 0.847). The ‘fresh’ 20:50 Hz force ratio was, in contrast, extremely reliable throughout the tested voltage range (CV ≤5.8%; p = 0.636) in fresh muscle. In experiment B paired t-tests indicated that the fatiguing protocol induced significant high-frequency fatigue ( p <0.0037) and low-frequency fatigue ( p <0.0008 for ‘fresh’ versus ‘fatigued’ 10:50 Hz force ratio; p <0.0001 for ‘fresh’ versus ‘fatigued’ 20:50 Hz force ratio). In muscle thus fatigued, the 20:50 Hz force ratio was extremely reliable in the 20–33% of MVC range (CV ≤7.3%; p = 0.847). Between-days repeatability was poor for the 10:50 Hz force ratio in both fresh and fatigued muscle (CV ≤23.8 and 44.4% respectively), but was highly acceptable for both voluntary and stimulated fatigue indices and for the 20:50 Hz force ratio, the latter in both fresh and fatigued muscle. Conclusions: These results confirm the validity and reliability of submaximal voltages in assessing contractile properties (including low-frequency fatiguability) and inducing fatigue of human TA.
Relationship between impairments, disability and handicap in reflex sympathetic dystrophy patients: a long-term follow-up study
Authors: Geertzen Jan Hb , Dijkstra Pieter U , Sonderen Eric Lp van , Groothoff Johan W , Duis Henk Jan ten , Eisma Willem H 
Published: March 2004

Objective: To determine the relationship between impairments, disability and handicap in reflex sympathetic dystrophy (RSD) patients. Design: A long-term follow-up study of upper extremity RSD patients. Setting: A university hospital. Subjects: Sixty-five patients, 3–9 years (mean interval 5.5 years) after RSD of the upper extremity (mean age 50.2 years). Main outcome measures: Impairments: range of motion, moving two point discrimination, muscle strength of the hand and pain were measured. Disability was assessed with the Groningen Activity Restriction Scale (GARS) and handicap was assessed with three subscales (social functioning, role limitations due to physical problems and role limitations due to emotional problems) of the RAND-36. Results: After RSD of the upper extremity, 62% of the patients are limited in activities of daily living (ADL) and/or instrumental ADL (IADL). Pain and restrictions in forward flexion of the shoulder, thumb opposition and grip strength are the most important impairments limiting ADL and IADL. Patients with limitations in ADL and IADL are significantly more handicapped than patients without limitations. Pain is the most important factor contributing to handicap. Conclusion: The relationship between impairments and disability and between disability and handicap in RSD patients is weak to moderate. Pain is the most important factor leading to disability and handicap.
Small Nuclear RING Finger Protein Stimulates the Rat Luteinizing Hormone-β Promoter by Interacting with Sp1 and Steroidogenic Factor-1 and Protects from Androgen Suppression
Authors: Curtin Denis , Ferris Heather A. , Häkli Marika , Gibson Matthew , Jänne Olli A. , Palvimo Jorma J. , Shupnik Margaret A. 
Published: March 2004

AbstractGnRH controls expression of the LH subunit genes, α and LHβ, with the LHβ subunit regulated most dramatically. Two enhancer regions, distal and proximal, on the rat LHβ gene promoter cooperate for full basal expression and GnRH stimulation. It has been hypothesized that the transcription factors binding to these regions, Sp1, Egr-1, and steroidogenic factor 1 (SF-1), may interact directly or indirectly via a coactivator. One such coactivator may be small nuclear RING finger protein (SNURF), which is expressed in pituitary tissue and the LβT2 gonadotrope cell line. In transfection experiments in LβT2 cells, SNURF stimulated basal expression of LHβ and increased overall GnRH stimulation. SNURF specifically stimulated LHβ, with no effect on the α-subunit promoter. SNURF interacts with Sp1 and SF-1, but not Egr-1, in pull-down experiments. Point mutations or deletions of SNURF functional domains demonstrated that Sp1 and SF-1 interactions with SNURF are required for SNURF stimulatory effects on the LHβ promoter. Endogenous SNURF is associated with the LHβ promoter on native chromatin, suggesting that it plays a physiological role in LHβ gene expression. SNURF also binds the androgen receptor, and SNURF overexpression overcomes androgen suppression of GnRH-stimulated LHβ but not αsubunit promoter activity. SNURF mutations that disrupt Sp1 or SF-1 binding eliminate rescue by SNURF. We conclude that SNURF may mediate interactions between the distal and proximal GnRH response regions of the LHβ promoter to stimulate transcription and can also protect the promoter from androgen suppression.
Central activity of hydroalcoholic extracts from Erythrina velutina and Erythrina mulungu in mice
Authors: Vasconcelos Silvânia M M , Macedo Danielle S , de Melo Carla Thiciane V , Monteiro Andreisa Paiva , Cunha Geanne M A , Sousa Francisca Cléa F , Viana Glauce Socorro B , Rodrigues Alexandre César P , Silveira Edilberto R 
Published: March 2004

Abstract
This work studied the central behavioural effects of hydroalcoholic extracts from the stem bark of Erythrina velutina and Erythrina mulungu on the elevated plus maze, open field, and rota rod tests in mice. These medicinal plants belong to the Fabaceae family and are popularly used in Brazil for their effects on the central nervous system. Single doses of the extracts were administered orally (200, 400 or 800 mg kg−1) or intraperitoneally (200 or 400 mg kg−1) to female mice. A reduction of the locomotor activity was observed in the open field test with both hydroalcoholic extracts after intraperitoneal treatment with all doses, but only with the highest dose after oral administration. In addition, oral and intraperitoneal administration of the extracts decreased the incidence of rearing and grooming. Decreases in the number of entries in the open (NEOA)and closed (NECA)arms of the elevated plus maze were observed after the administration of the highest dose (800 mg kg−1, p.o.) of both hydroalcoholic extracts, and this effect may be due to the decrease in locomotor activity. These hydroalcoholic extracts failed to affect the motor coordination in the rota rod test. In conclusion, we showed that the hydroalcoholic extracts of E. velutina and E. mulungu have depressant effects on the central nervous system, which, at least partially, corroborates the popular use of these species as tranquilizers in Brazilian popular medicine.
Effect of P-glycoprotein inhibition on methadone analgesia and brain distribution in the rat
Authors: Rodriguez Monica , Ortega Ignacio , Soengas Itziar , Suarez Elena , Lukas John C , Calvo Rosario 
Published: March 2004

Abstract
Methadone is an opiate drug that has been identified as an in-vitro substrate of the efflux pump P-glycoprotein (P-gp), active in the intestinal epithelium and in the blood–brain barrier (BBB), among other sites. The objective of this study was to test in vivo, in the rat model, the role of P-gp modulation on the analgesic effect and brain uptake of methadone, as well as identify the most relevant site via dual oral and intravenous (i.v.) experiments. The P-gp specific inhibitor (valspodar or PSC833) was preadministered (10 mg kg−1 i.v.) to test groups. Analgesia was measured using the tailflick test. The ED50 for oral methadone (2, 3, 6 and 8 mg kg−1) decreased three-fold in valspodar groups compared with controls (2.23 + 0.002 mg kg−1 and 6.07 + 0.07 mg kg−1; P &lt; 0.0001). The overall analgesic effect (% antinociception) was elevated 3.1 times in pretreated compared with control rats (90.65% + 0.22 vs 29.23% + 14.0; P &lt; 0.01) after 6 mg kg−1 oral methadone and 2.8 times after i.v. (0.35 mg kg−1) administration (91.75% + 4.27 vs 32.45% + 9.0; P &lt; 0.01). The brain:plasma distribution ratio was higher in pretreated animals and AUCbrain (overall brain concentration) was 6 times higher after oral methadone and 4 times higher after i.v. compared with controls, disproportionally increased relative to plasma, implying an active process at the BBB. P-gp, and hence substrate comedication, plays a critical role in the evolution of the methadone analgesic effect and in its brain uptake, independent of the administration route.
Melatonin reverses urinary system and aorta damage in the rat due to chronic nicotine administration
Authors: Sener Göksel , Kapucu Caner , Paskaloglu Kübra , Ayanoglu-Dülger Gül , Arbak Serap , Ersoy Yasemin , Alican Inci 
Published: March 2004

Abstract
We have evaluated the changes in contractile activity and oxidant damage of corpus cavernosum, urinary bladder, kidney and aorta after chronic nicotine administration in rats. The effects of melatonin on these parameters were investigated also. Male Wistar albino rats were injected intraperitoneally with nicotine hydrogen bitartrate (0.6 mg kg−1 daily for 21 days) or saline. Melatonin (10 mg kg−1, i.p.) was administered either alone or with nicotine injections. Corpus cavernosum, bladder and aorta were used for contractility studies, or stored with kidneys for the measurement of malondialdehyde and glutathione levels. Corpus cavernosum, bladder, and aorta samples were examined histologically and the extent of microscopic tissue damage was scored. In the nicotine-treated group, the contraction of corpus cavernosum, bladder and aorta samples and the relaxation of corporeal and aorta tissues decreased significantly compared with controls. However, melatonin treatment restored these responses. In the nicotine-treated group, there was a significant increase in the malondialdehyde levels of the corporeal tissue, bladder, kidney and aorta, with marked reductions in glutathione levels compared with controls. Melatonin treatment reversed these effects also. Melatonin administration to nicotine-treated animals caused a marked reduction in the microscopic damage of the tissues compared with those of the untreated group. In this study, nicotine-induced dysfunction of the corpus cavernosum, bladder and aorta of rats was reversed by melatonin treatment. Moreover, melatonin, as an antioxidant, abolished elevation in lipid peroxidation products, and reduction in the endogenous antioxidant glutathione, and protected the tissues from severe damage due to nicotine exposure.
Effect of lubricant type and concentration on the punch tip adherence of model ibuprofen formulations
Authors: Roberts Matthew , Ford James L , Rowe Philip H , Dyas A Mark , MacLeod Graeme S , Fell John T , Smith George W 
Published: March 2004

Abstract
A model formulation, comprising ibuprofen and direct compression lactose (Tablettose 80) was used to assess the influence of two lubricants, magnesium stearate and stearic acid, on punch tip adherence. Lubricant concentrations were varied from 0.25% to 2% w/w. Formulations in the presence and absence of 0.5% w/w colloidal silica (Aerosil 200) were examined, to assess the influence of the glidant on the anti-adherent effects of the lubricants. Differential scanning calorimetry (DSC) was used to examine the effect of the lubricants on the melting temperature of ibuprofen. Tablets were compacted using a single punch tablet press at 10 kN using hard chrome-plated punches or at 40 kN using uncoated steel punches, tooling was 12.5-mm diameter in each case. The upper punch faces were characterized by obtaining Taylor Hobson Talysurf surface profiles. Following compaction, ibuprofen attached to the face was quantified by spectroscopy. At low concentrations of each lubricant, the levels of sticking observed were similar. Whilst sticking increased at magnesium stearate concentrations above 1%, sticking with stearic acid remained relatively constant at all concentrations. DSC revealed that the melting temperature of ibuprofen was lowered by the formation of eutectic mixtures with both lubricants. However, the onset temperature of melting and melting point were lowered to a greater extent with magnesium stearate compared with stearic acid. When using uncoated tooling at 40 kN, the deleterious effects of magnesium stearate on the tensile strength of the tablets also contributed to sticking. When using chrome-plated punches at 10 kN, the tensile strength reduction by the presence of magnesium stearate was less pronounced, as was the level of sticking.
Pretreatment with Ginkgo biloba extract weakens the hypnosis action of phenobarbital and its plasma concentration in rats
Authors: Kubota Yoko , Kobayashi Kyoko , Tanaka Naoko , Nakamura Kazuki , Kunitomo Masaru , Shinozuka Kazumasa , Kubota Yoko , Kunitomo Masaru , Shinozuka Kazumasa , Umegaki Keizo 
Published: March 2004

Abstract
In a previous study, we found that orally administered Ginkgo biloba extract (GBE) induced hepatic cytochrome P450 (CYP) in rats, especially the CYP2B type. This fact suggested that GBE influenced the availability and safety of drugs that were metabolized via CYP2B type enzymes. To confirm this possibility, in this study we examined the effect of feeding a 0.1, 0.5 and 1.0% GBE diet for 2 weeks on the pharmacokinetics and pharmacological action of phenobarbital, which is known to be metabolized by CYP2B in Wistar rats. The feeding of GBE markedly shortened the sleeping time in rats. Furthermore, the maximal phenobarbital plasma concentration (Cmax) and the 24-h area under the curve (AUC0–24) were decreased in rats fed GBE. These findings indicate that GBE reduces the therapeutic potency of phenobarbital via enhancement of cytochrome P450 expression, and raises the possibility that GBE and drug interactions may occur clinically.
Quantitative structure-pharmacokinetic relationship modelling: apparent volume of distribution
Authors: Ghafourian Taravat , Barzegar-Jalali Mohammad , Hakimiha Nasim , Ghafourian Taravat , Cronin Mark T D 
Published: March 2004

Abstract
The purpose of this study was to develop a quantitative structure-activity relationship (QSAR) for the prediction of the apparent volume of distribution (Vd) in man for a heterogeneous series of drugs. The relationship of many computed, and some experimental, structural descriptors with Vd, and the Vd corrected for protein binding (unbound Vd), was investigated. Models were constructed using stepwise regression analysis for all the 70 drugs in the dataset, as well as for acidic drugs and basic drugs separately. The predictive power of the models was assessed using half the chemicals as a test set, and revealed that the models for Vd yielded lower prediction errors than those constructed for the unbound Vd (mean fold error of 2.01 for Vd compared with 2.28 for unbound Vd). Moreover, the separation of the compounds into acids and bases did not reduce the prediction error significantly.
Systemic and ocular pharmacokinetics of N-4-benzoylaminophenylsulfonylglycine (BAPSG), a novel aldose reductase inhibitor
Authors: Sunkara Gangadhar , Ayalasomayajula Surya P , Rao Cheruku S , Vennerstrom Jonathan L , Kompella Uday B , DeRuiter Jack , Kompella Uday B 
Published: March 2004

Abstract
To better develop N-[4-(benzoylamino)phenylsulfonyl]glycine (BAPSG), a potent and selective aldose reductase inhibitor capable of delaying the progression of ocular diabetic complications, the objective of this study was to assess its pharmacokinetics. The plasma pharmacokinetics of BASPG was assessed in male Sprague-Dawley rats following intravenous, intraperitoneal and oral routes of administration and its distribution to various tissues including those of the eye was studied following intraperitoneal administration. In addition, rat plasma protein binding of BAPSG was studied using ultracentrifugation method and its ocular tissue disposition was assessed following topical administration in rabbits. Plasma and tissue levels of BAPSG were analysed using an HPLC assay. BAPSG exhibited dose-proportionate AUC0→∞ (area under the plasma concentration-time curve) following both intravenous and intraperitoneal administration over the dose range (5–50 mg kg−1) studied and an erratic oral absorption profile with low oral bioavailability. The fraction bioavailability following oral and intraperitoneal administration was 0.06 and 0.7–1, respectively. BAPSG exhibited short plasma elimination half-lives in the range 0.5–1.5 h. BAPSG was bound to rat plasma proteins and the percent protein binding ranged from 83 to 99.8%. BAPSG was better distributed to cornea, lens and retina than to brain, following intraperitoneal administration in rats. However, the distribution was lower compared with kidney and liver. Following topical administration in rabbits, BAPSG delivery to the surface ocular tissues, cornea and conjunctiva was higher compared with intraocular tissues, aqueous humour, iris-ciliary body and lens. Thus, BAPSG was distributed to ocular tissues following systemic and topical modes of administration.
Medicinal plants in Suriname: hypotensive effect of Gossypium barbadense
Authors: Hasrat J A , Pieters L , Vlietinck A J 
Published: March 2004

Abstract
In traditional medicine Gossypium barbadense L. is used against hypertension. Looking for a scientific basis for this use, the blood-pressure-lowering effect of the decoction of the leaves was confirmed. Fraction II (frII) of the crude extract of G. barbadense showed a dose-dependent hypotensive effect in anaesthetized rats. In hexamethonium-treated rats, the blood-pressure-lowering effect of frII was almost abolished. A small decrease of the blood-pressure-lowering effect was followed by an increase in the blood pressure. Phentolamine antagonized the increase in blood pressure in hexamethoniumtreated rats. High doses of atropine (4 mg/rat) suppressed both depressor and heart effects. In-vitro experiments revealed that atropine did not antagonize the contraction of the ileum of the rat. Tripelennamine in a concentration of 100 μg could not influence the contraction either, whereas 300 μg did. In the guinea-pig ileum 10 μg tripelennamine did not reduce the contraction significantly.
In the mechanism of action of frII, acetylcholine receptors could be involved, but not histaminergic or adrenergic receptors. Although it is still not known which compound(s) in G. barbadense is (are) the active substance(s), the results obtained may explain the use of this plant in traditional medicine in Suriname.
Polymeric nanoparticles composed of fatty acids and polyvinylalcohol for topical application of sunscreens
Authors: Luppi B , Cerchiara T , Bigucci F , Basile R , Zecchi V 
Published: March 2004

Abstract
Benzophenone-3 (BZP) or oxybenzone is widely used in many cosmetic formulations, such as sunscreen lotions or emulsions, shampoos and hair sprays. The nature of the vehicle used can enhance or block the percutaneous absorption of UV filter. In this work, we hydrophobically modified polyvinylalcohol 10000 (PVA) with fatty acids (FAs) to obtain PVA-FA derivatives for the preparation of lipophilic polymeric nanoparticles able to prevent BZP movement towards the skin. Synthesized PVA-FA derivatives were confirmed by H1NMR. Nanoparticles loaded with BZP were prepared using a solvent extraction method. The particle size was monitored by means of dynamic light scattering measurements. In-vitro skin permeation studies were performed.
Modeling of Pedestrian Delays with Pulsed Vehicular Traffic Flow
Authors: Guo Xiaoping , Dunne Michael C. , Black John A. 
Published: March 2004

The phenomenon of the bunching of urban traffic is considered together with a mathematical model for the associated problem of the delay to pedestrians crossing a traffic stream. The approach used is also applicable to estimating delay to a single vehicle at a priority intersection and to merging vehicular traffic. Many pedestrian delay models include the assumption that successive vehicular headways are independent and identically distributed random variables. Such models may not be appropriate where vehicles form bunches—as occurs, for example, near traffic signals. Modeling of pedestrian delay is considered in two parts: the delay to pedestrians arriving during a vehicular bunch, and delay to those arriving during the random flow between bunches. These two parts are considered in combination to obtain overall delay. Three field surveys were conducted in metropolitan Sydney. Useable data were obtained on 4,350 headways and 252 crossing pedestrians on major arterial roads. The field data were used to assess the validity and accuracy of the proposed model. They support the theoretical model and suggest that, under certain conditions, it provides a more accurate estimation of pedestrian delays downstream of traffic signals than do some existing models, such as Adams' (1936) model.