bluuebunny/crossref_metadata_2025_split huggingface dataset:
OCT Macular Changes in Amblyopic Children
Authors: Abdelmeseh Bola George , Shafik Heba Mohamed , Arafa Elsayed Samir , Ali Ahmed Lotfi 
Published: April 2022

Background: Amblyopia is defined as a decrease in best-corrected visual acuity in one or both eyes that is not solely due to a defect in the structure of the eye. This study aimed to investigate the OCT changes occurring in the amblyopic eye retina compared to normal eye.
Methods: This prospective study was carried out on 30 cases diagnosed with amblyopia using the better eye as a control. Patients were subjected to Assessment (visual acuity was measured by Landolt’s chart. Refraction error measured by autorefractometer) and macular analysis.
Results: CMT was statistically insignificant difference between amblyopic and non-amblyopic eyes. The difference in AMT between amblyopic and non-amblyopic eyes was statistically significant (p = 0.001). BCVA in different ages before and after treatment was statistically significant difference (P=0.001). The various types of refractive errors of the studied eyes regarding BCVA, before and after treatment was statistically significant difference (P=0.001).
Conclusions: CMT and AMT of the amblyopic eye more than the sound eye and after 6 months of patching, there was a decrease in the CMT and AMT of the amblyopic eye.
Pregnancy and its outcome in quadriplegia due to Pott's spine
Authors: Vaidya M.K. , Shah G.V. , Bharucha K.E. 
Published: July 2002

AbstractPregnancy with quadriplegia is a problem sometimes encountered in obstetric practice. The etiology of quadriplegia in the developed world is mainly spinal cord tumor or accident, while in the developing countries the main cause is tuberculosis of the spine. We report the management of two pregnant patients with quadriplegia due to tuberculosis of the cervical spine. Worsening of the neurological condition necessitated early surgical intervention, and termination of pregnancy was advised in both patients. Literature on the subject makes frequent reference to the life‐threatening complication of autonomic hyperreflexia encountered during pregnancy and delivery. It is characterized by sweating, headache, severe hypertension leading to unconsciousness and convulsions. These complications, surprisingly, were absent in both of our patients.
On the mechanism of the inhibition of Na+, K+‐ATPase activity caused by homocysteine
Authors: Streck Emilio L. , Zugno Alexandra I. , Tagliari Bárbara , Sarkis João J.F. , Wajner Moacir , Wannmacher Clóvis M.D. , Wyse Angela T.S. 
Published: July 2002

AbstractIn the present work, we investigated the kinetics of the inhibition of Na+, K+‐ATPase activity caused by homocysteine (Hcy) in rat hippocampus. We also studied the interaction between Hcy and phenylalanine (Phe) and the kinetics of alanine (Ala) reversal of the inhibition of Na+, K+‐ATPase caused by Hcy. The apparent Km and Vmax of Na+, K+‐ATPase for ATP as substrate were 0.55 mM and 2.0 nmol Pi released per min per mg of protein, respectively. Ki value was approximately 0.1 mM, and the inhibition was of the non‐competitive type. The results also showed a competition between Hcy and Phe. Ala per se did not alter this enzyme, but prevented the inhibitory effect caused by Hcy, suggesting a common binding site for these substances. It is proposed that the inhibition of Na+, K+‐ATPase by Hcy may be one of the mechanisms related to the neuronal dysfunction observed in human homocystinuria.
Characterization of a Novel Biocatalyst System for Sulfide Oxidation
Authors: McComas Charles , Sublette Kerry L. , Jenneman Gary , Bala Greg 
Published: July 2002

AbstractIt has been demonstrated that an enrichment culture dominated by Thiomicrospira sp. CVO may be cultured on H2S(g) as an energy source under sulfide‐limiting conditions in suspended culture with nitrate as the electron acceptor. Hydrogen sulfide (10,000 ppmv) was completely removed from the feed gas and oxidized to sulfate in <3 s of gas‐liquid contacting time. Maximum loading of the biomass for sulfide oxidation was observed to be 5.8 mmol H2S/h‐g biomass protein, comparable to that reported previously for Thiobacillus denitrificans under similar conditions. However, the enrichment culture was shown to be more tolerant of extremes in pH and elevated temperature than T. denitrificans. Coupled with a reported tolerance of CVO for up to 10% NaCl, these observations suggest that a CVO‐based culture is potentially a more robust biocatalyst system for sulfide oxidation than cultures based on Thiobacilli.
Adsorption of Protein from Several Commercial Lipase Preparations onto a Hollow‐Fiber Membrane Module
Authors: Balcão Victor M. , Vieira Madalena C. , Malcata F. Xavier 
Published: July 2002

AbstractTen commercially available crude preparations of lipase from various microbial sources were adsorbed from aqueous buffers at several initial concentrations onto a bundle of hydrophobic hollow fibers made of poly(propylene) at pH 7.0 and 40 °C. The kinetics of adsorption were evaluated from measurements at various times of the protein content of the supernatant solution (using BSA as equivalent) in a well‐mixed reservoir placed in series with the hollow fiber module. Preliminary tracer experiments have indicated that the module and the tank can be simulated as a system consisting of a plug flow reactor in series with a continuous stirred tank reactor. A mechanistic model based on the hydrodynamic assumptions associated with this system coupled with the postulation of two reversible first‐order steps for the adsorption of protein was successfully fitted to the experimental data via nonlinear regression analysis. The statistical significance of the model was checked using tests for lack of fit. This work is useful in predicting the time period required to immobilize a (crude) lipase by adsorption onto a hydrophobic hollow fiber module, a configuration which has proved successful in the recent past for the performance of lipase‐catalyzed reactions.
Gaulin Homogenization: A Mechanistic Study
Authors: Lander R. , Manger W. , Scouloudis M. , Ku A. , Davis C. , Lee A. 
Published: July 2002

AbstractFree radical‐based oxidation has been detected in the normal operating regime of the Gaulin homogenizer, demonstrating that cavitation occurs in this important industrial bioprocessing equipment. Free radical generation is suppressed by imposition of back pressure, proving that such cavitation occurs in the impingement section. The calculated value of the cavitation number is consistent with submerged jet cavitation, wherein a high‐speed jet exiting from the valve gap accelerates fluid in the impingement region, creating the vacuum conditions for cavitation. Using polysaccharides as a model shear‐sensitive compound, their breakage pattern in the homogenizer was characterized by molecular size and polydispersity and compared to those of fluid shear flows in capillary tubes and cavitating flow from a sonic horn. The results indicate that breakage occurs primarily by fluid shear, although a contribution by cavitation is also apparent when back pressure is applied. Because biological molecules can readily react with free radicals and the alterations caused thereby are subtle in nature, a thorough evaluation of the impact of free radicals in upstream homogenization is warranted.
Psychological stress in undergraduate dental students: baseline results from seven European dental schools
Authors: Humphris Gerry , Blinkhorn Andy , Freeman Ruth , Gorter Ronald , Hoad‐Reddick Gillian , Murtomaa Heikki , O'Sullivan Robin , Splieth Christian 
Published: July 2002

Objectives: To determine the degree of psychological distress, the experience of emotional exhaustion, and the extent of stress associated with course work in dental students and to compare these measurements among seven European dental schools.Design: Multi‐centred survey.Setting: Dental Schools at Amsterdam, Belfast, Cork, Greifswald, Helsinki, Liverpool and Manchester.Participants: 333 undergraduate first‐year dental students.Measures: General Health Questionnaire (GHQ12), Maslach Burnout Inventory (MBI), Dental Environment Stress Questionnaire (DES), demographic variables.Procedure: Questionnaire administered to all students attending first year course. Completed questionnaires sent to central office for processing.Results: Seventy‐nine percent of the sampled students responded. Over a third of the students (36%) reported significant psychological distress (morbidity) at the recommended cut‐off point (>3 on GHQ). These scores were similar to those reported for medical undergraduates. Twenty‐two percent recorded comparatively high scores on emotional exhaustion. A wide variation in these 2 measurements was found across schools (p's<0.001). Stress levels indicated by the DES were less variable (p>0.5). Some evidence showed that contact with patients and the level of support afforded by living at home may be protective.Conclusion: Higher than expected levels of emotional exhaustion were found in a large sample of first‐year undergraduate dental students in Europe.
The UBiT‐100 13CO2 Infrared Analyzer: Comparison Between Infrared Spectrometric Analysis and Mass Spectrometric Analysis
Authors: Ohara Shuichi , Kato Mototsugu , Asaka Masahiro , Toyota Takayoshi 
Published: July 2002

Background.Although the 13C‐urea breath test is the most accurate noninvasive method for detecting the presence of H. pylori infection, the requirement for an expensive mass spectrometer to analyze breath samples has prevented physicians from providing rapid results near the patient. Recently, a new type of infrared spectrometric analyzer, the UBiT‐100, was developed for analyzing 13CO2 in breath. The purpose of this study is to compare results analyzed by the UBiT‐100 to those analyzed by the mass spectrometric method.Methods.Four hundred and fifty‐three subjects participated in this study. Breath samples were collected before administration of 100~mg of 13C‐urea and at 10, 20, 30, 45 and 60~min after administration. Subjects were asked to hold their breath for 10~sec and then exhale in order to collect breath samples containing more than a 2% concentration of CO2. Samples were then analyzed by both methods.Results.The correlation analysis using values at 20~min after the administration of the study drug (433 points) was excellent with the regression equation of Y~=~1.034x − 0.203;r~=~.996. The results of the UBiT‐100 were available in 6~min, making the entire testing procedure less than 30~min.Conclusions.The UBiT‐100 infrared analyzer provides a simple and accurate method of performing the urea breath test while the patient is still in the doctor's office.
On the growth of two dimensional crystals. I. Fluctuations and the relation of step free energies to morphology
Authors: Sadler David M. 
Published: July 2002

Some fundamental aspects of crystallization of two dimensional (2D) crystals are examined, including an analysis of the fluctuations in step positions, computer simulation results for the step density and growth rates, and analysis for predicting crystal shapes. A discussion is given of whether nucleation can occur on the 1D surface of a 2D crystal. During the course of the paper it is shown that a more appropriate description, for any infinite 1D surface, is of a step density related to the equilibrium value and a growth rate which is proportional to the density and speed of these steps. The speed depends essentially linearly on the net thermodynamic driving force for crystallization. (This description is not appropriate for a 2D surface since the equilibrium step density can then be zero.) Nevertheless, one can define a criterion, depending both on the density of steps and on the extent of the fluctuations in step positions, for a regime of growth with some similarities to nucleation (1D nucleation). Kinetic (nucleation) theories for polymer crystallization, using a rate equation approach, have implicitly assumed the conditions for 1D nucleation to hold. Even when the conditions do not hold, the results of this rate equation approach are in reasonable agreement with the simulation results (though a rather curious discrepancy of a factor of 21/2 occurs since the rate equation approach omits a growth mediated approach to equilibrium). The agreement in general trend is shown to be the fortuitous consequence, in the rate equation approach, of neglecting both the enhancement of step annihilations caused by fluctuations and the creation of pairs of steps at cavities. If the latter effect is neglected but not the former, anomalous results can be obtained which violate thermodynamic principles. Growth rate results from simulation are obtained as a function of the obliquity of the growth face with respect to the principal directions in the lattice. These growth rate anisotropy data are used to predict the shapes of crystal outlines. Comparisons between these results and
experimental observations on shapes of polymer crystals are made, and a preliminary account is given of how the step free energy per length of step decreases with increasing temperature. In general, the total step free energies tend to decrease as the crystal thickness increases for polyethylene.
The thermodynamic stability of clathrate hydrate. II. Simultaneous occupation of larger and smaller cages
Authors: Tanaka Hideki , Kiyohara Kenji 
Published: July 2002

The thermodynamic stability of a clathrate hydrate encaging methane or xenon has been investigated by examining the free energy of formation. The total free energy is divided into several contributions: the interaction between water and guest molecules, the entropic contribution arising from the combinations of cage occupancy, and also the free energy arising from the guest molecular motions inside cages. Our method is based on the generalized van der Waals and Platteeuw theory used for the study of the hydrate encaging propane and is free from some of the fundamental assumptions in the original theory. This enables us to evaluate separately the factors which contribute significantly to the thermodynamic stability of the hydrate, and to address a question as to what extent the original theory is applicable to the prediction of the phase diagrams. While the potential energy curve of the guest molecule with surrounding water molecules in a smaller cage has a single minimum and the molecular motion can be accurately approximated to a collection of harmonic oscillators strongly coupled with the host molecules, the guest molecular motion in a larger cage does not couple with the host. To show evidence that the fixed lattice approximation is sufficient to describe molecular motions inside the larger cage, two kinds of molecular dynamics simulations have been carried out.
In one simulation, both host water and guest molecules move according to the classical equations of motion. In another simulation only guest molecules are allowed to move, interacting with fixed host molecules. We perform two kinds of analyses on those motions. In the first analysis, the velocity autocorrelation functions are calculated from molecular dynamics simulations at several temperatures and the power spectra are obtained by the Fourier transform of the correlation functions. In the second, a so-called normal mode analysis is performed and the densities of state for intermolecular vibrations are obtained. The densities of state (corresponding to 0 K) are compared with the power spectra. It is revealed that the fixed lattice approximation can be applied when describing the molecular motions of methane and xenon in larger cages. The free energy for the accommodation of an extremely large CF4 or small argon guest is also examined.
Levels of soluble ICAM‐1 in premature and full‐term neonates with infection
Authors: Apostolou Melita , Dimitriou Helen , Kaleyias Joseph , Perdikogianni Chrissoula , Stiakaki Eftichia , Costalos Christos , Kalmanti Maria 
Published: July 2002

Background: Infection in the neonatal period is an extremely serious condition and diagnosis is difficult. C‐reactive protein (CRP) is widely used as a marker of infection; however, its usefulness is limited in the early phase. The role of soluble intracellular adhesion molecule‐1 (sICAM‐1), an adhesion molecule, has been examined in recent studies as an early marker of neonatal infection with controversial results.Aim: Assessment of sICAM‐1 concentrations and correlation with CRP, which is the currently used marker of infection, in order to use sICAM as an early diagnostic tool in neonates suspected for infectionMethods: Blood samples and blood cultures were obtained from two groups of pre‐term and full‐term neonates with clinical suspicion of infection prior to the initiation of antibiotics. The sICAM‐1 and CRP values were compared with the corresponding non‐infected ones
(n = 10 each).Results: The sICAM‐1 levels were found increased in the group of both premature and term neonates with infection compared with the corresponding healthy ones (p < 0.0001). Prematurity combined with infection resulted in excessive increase of the levels of sICAM‐1 in comparison with full‐term infected newborns (p < 0.001). CRP values were normal in all samples except one in both full‐term and premature infected neonates on day 1 of clinically suspected infection. Serial detection of CRP values on days 2 and 4 of infection revealed a pattern according to which CRP values in premature neonates continued rising, while in the group of full terms these values, after rising on the second day, lowered on day 4.Conclusions: Increased sICAM‐1 levels can be detected early in both full‐term and premature neonates with sepsis while CRP levels are within normal range at the sametime. Assessment of sICAM‐1 concentrationsmay be used as a diagnostic tool in neonates suspected for infection, resulting in earlier initiation of antibiotic therapy and therefore improving their outcome.
Alterations in excitatory amino acid‐mediated regulation of midbrain dopaminergic neurones induced by chronic psychostimulant administration and stress: relevance to behavioural sensitization and drug addiction
Authors: CLARK DAVID , OVERTON PAUL G. 
Published: July 2002

AbstractRepeated, intermittent administration of the psychostimulants d‐amphetamine and cocaine, as well as other drugs of abuse, leads to an enduring augmentation of certain behavioural responses (e.g. locomotor activity) produced by these drugs. This behavioural sensitization has been the subject of considerable interest due to its potential relevance to drug addiction. Repeated administration of d‐amphetamine also leads to an enhancement in the ability of electrical stimulation of the prefrontal cortex to induce burst firing in midbrain dopaminergic (DA) neurones. This hyper‐responsiveness probably reflects a potentiation of transmission at excitatory amino acid (EAA)ergic synapses on DA neurones. In addition, we have previously reported that selective activation of mineralocorticoid receptors (MRs) by corticosterone leads to a potentiation of EAA‐induced burst firing in midbrain DA neurones, an effect antagonized by glucocorticoid receptor (GR) activation. In this review article, we propose a model describing how drugs of abuse and stress alter EAA function at the level of DA cells in the ventral tegmental area (VTA), which can result in a long‐lasting impact on behaviour. D‐amphetamine produces a transitory increase in EAA‐mediated transmission at the level of DA cells in the VTA, which triggers a more long‐lasting change in EAAergic function resembling hippocampal long‐term potentiation. Dopaminergic burst events are likely to be a critical link between enhanced EAAergic activity in afferents synapsing on DA neurones and plasticity at these synapses, by increasing calcium transport into the cell, which is known to be an important factor in synaptic plasticity. Selective MR occupation by corticosterone in the VTA facilitates the development of this plasticity. However, we hypothesize that during stress, GR‐occupation also activates EAAergic afferents to DA neurones in a manner similar to that following psychostimulants. Under these circumstances, GR‐occupation acts via circuitry external to the VTA, which may include the hippocampus. Thus, potentiation of EAAergic synapses on DA neurones in the VTA may represent a final common pathway by which two divserse means (psychostimulants and stress) achieve the same end (sensitization). Alterations in EAA‐mediated transmission at the level of DA cells not only plays a critical role in the induction of behavioural sensitization, but probably continues to produce abnormal DA cell responses in the drug‐free situation.
Metastatic Osteosarcoma: A Review of Current Issues in Systemic Treatment
Authors: Bramwell Vivien 
Published: July 2002

Purpose. Original articles and abstracts published between January 1991 and January 1997
were selected according to specified criteria and reviewed to provide answers to five interesting questions about the
systemic treatment of metastatic osteosarcoma.Results.(1) In patients with metastatic disease at presentation, what is the outcome after intensive multi‐agent chemotherapy?Historically, survival has been poor, but may be improving with the use of ifosfamide‐containing regimens.(2) Can response to new agents be evaluated better in patients who have received no previous chemotherapy?Based on limited data, this is probably true.(3) Is the response to neo‐adjuvant chemotherapy, as determined by histopathology, similar for the primary tumor and
synchronous pulmonary metastases?With intensive multi‐agent chemotherapy, good histological response rates are in the range 70–90% for both groups.(4) What is the outcome, after intensive combined modality treatment with chemotherapy and surgery, in patients
relapsing with metastases after previous adjuvant chemotherapy, and what are the important prognostic factors?Outcome is highly variable, but 5‐year survival ranges between 25 and 50% and a good outcome is more likely if
recurrent disease is limited to resectable lung metastases.(5) Can a biological agent (L‐MTP‐PE) prolong the time to relapse in patients with resected metastatic osteosarcoma?Preliminary data suggest that this is possible, but more studies are required.
The Geometric Osteotomy: Joint Preservation in Juxta‐Articular Surface Bone Neoplasms
Authors: Masterson Eric L. , Ferracini Riccardo , Davis Aileen M. , Wunder Jay S. , Bell Robert S. 
Published: July 2002

Purpose. To present the oncologic and functional results of a consecutive series of patients treated by geometric
osteotomy and allograft reconstruction for juxta‐articular surface bone neoplasms.Patients. Twelve consecutive patients (mean age 28 years) underwent excision of benign aggressive or malignant
juxta‐articular surface bone neoplasms. In each case, only part of the circumference of the bone was excised, and the joint
surface was preserved and kept in continuity with the remainder of the bone. The defects were filled with allograft or
autograff, and internally fixed as appropriate.Methods. Patients were eligible for the study if they had a histologically proven, primary tumour of bone adjacent to a
joint such that the turnout could be completely excised with a partial cortical resection and preservation of the joint. The
database at the University Musculoskeletal Oncology Unit was used to identify all cases. Patient demographics and
oncologic results were recorded. Functional assessment was performed using the Musculoskeletal Tumor Society rating
scale and the Toronto Extremity Salvage Score.Results. Nine tumours were about the knee and three were in the proximal humerus. Negative margins were achieved in
all cases. No patient had metastatic disease at a mean follow‐up of 56.5 months. There was one local recurrence and this
was managed by conversion to a Van Nes rotationplasty. Functional results were excellent in the proximal humeral cases
and in cases about the knee where the stabilizing ligaments were preserved. Cases with post‐operative knee instability were
less successful but none the less were well controlled with bracing.Discussion. This technique offers an alternative to joint excision and prosthetic replacement in
a group of young patients.