bluuebunny/crossref_metadata_2025 huggingface dataset:
Case Report: Microbubble Contrast-Enhanced Ultrasound Characteristics of Multiple Biliary Hamartomas (von Meyenberg Complexes)
Authors: Berry Jonathan D , Boxer Mark E , Rashid Hisham I , Sidhu Paul S
Published: May 2004

Multiple biliary hamartomas (von Meyenberg complexes) are an uncommon benign biliary neoplasm detected incidentally on imaging. To our knowledge the appearances of multiple biliary hamartomas on microbubble contrast-enhanced ultrasound have not been previously described. We report a case using Coherent Contrast Imaging® and Agent Detection Imaging® techniques with the contrast agents Sonovue®and Levovist®. While both methodologies failed to differentiate these focal liver lesions from malignant neoplasms, they enhanced the conspicuity of the hamartomas. Radiologically-guided biopsy and histological analysis remain the reference standard in the diagnosis of multiple biliary hamartomas.
Endoanal Ultrasound
Authors: Maier Andrea
Published: May 2004

Endoanal sonography has proven its usefulness and, today, medical specialists within such areas as pelvic floor imaging, coloproctology, rectal surgery and incontinence are well aware of its value.
Short Course on Abdominal Ultrasound in Tropical Medicine, Pavia University, Pavia, Northern Italy, 16–20 February 2004
Authors: Conlon Rosie
Published: May 2004

Having had considerable practical experience of ultrasound in Tropical Medicine during my work in Africa establishing ultrasound training programmes, it was as a result of very kind sponsorship from Philips Medical Systems and BMUS that I had the opportunity to reinforce this with some theoretical education and training through attendance at this excellent short course held at the Division of Infectious and Tropical Disease at Pavia University. Pavia is an old provincial capital of Roman origin in Northern Italy and home to one of the more ancient universities in Europe, it is situated approximately 40 km south of Milan and in 1999 came first in the most 'liveable city' competition. It is a peaceful, clean town with a number of fine medieval churches and palaces in its cobbled streets.
The influence of N-acetyl-L-cystein infusion on cytokine levels and gastric intramucosal pH during severe sepsis
Authors: Emet Sayım , Memiş Dilek , Pamukçu Zafer
Published: May 2004

Introduction

The purpose of the present study was to evaluate the effects of continuously infused N-acetyl-L-cystein (NAC) on serum cytokine levels and gastric intramucosal pH in humans suffering from severe sepsis.

Methods

Fifty-three patients were included in the study. In the NAC group (n = 27), after an initial intravenous bolus of NAC (150 mg/kg over 5 min), a continuous intravenous infusion of 12.5 mg/kg per hour was given for 6 hours. Patients in the control group (n = 26) were administered dextrose (5% solution) at the same dosage. We recorded the following: haemodynamic parameters, nasopharyngeal temperature, arterial blood gas changes, plasma cytokine levels, biochemical parameters, intramucosal pH, length of stay in the intensive care unit, duration of of mechanical ventilation and mortality. All measurements were taken at baseline (15 min before the start of the study) and were repeated immediately after the bolus infusion, and at 24 and 48 hours after initiation of the continuous NAC infusion.

Results

No differences were found between groups in levels of the major cytokines, duration of ventilation and intensive care unit stay, gastric intramucosal pH and arterial oxygen tension/inspired fractional oxygen ratio (P > 0.05).

Conclusion

We found that NAC infusion at the doses given did not affect cytokine levels, outcomes, or gastric intramucosal pH in patients with severe sepsis. Because of the limited number of patients included in the study and the short period of observation, our findings need confirmation in larger clinical trials of NAC infused in a dose-titrated manner. However, our results do not support the use of NAC in patients with severe sepsis.
Preventing falls and stump injuries in lower limb amputees during inpatient rehabilitation: completion of the audit cycle
Authors: Gooday Helen MK , Hunter John
Published: May 2004

Objectives: To study the factors contributing to falls among recent lower limb amputees, and to reduce the number of falls during inpatient rehabilitation and resulting injuries.

Design: Retrospective, followed by prospective, cohort study, then a follow-up study conducted after interventions.

Setting: Twenty-bedded inpatient rehabilitation unit for amputees.

Subjects: Lower limb amputees.

Interventions: Patient education, environmental modifications and application of a bivalve plaster of Paris stump protector to patients who were aged 70 or over, or cognitively impaired.

Main outcome measures: Numbers of falls and other accidents, and resulting injuries.

Results: In phase 1 of the study, a retrospective audit of incident forms that had been completed on lower limb amputees who had an accident during their inpatient rehabilitation, between 1 April 1996 and 31 Ocotber 1998, was carried out. This showed that approximately a third of admissions (32%) were complicated by an accident. Most accidents were falls. In phase 2, a prospective study of 113 patients admitted to the unit was undertaken. Patients who fell were significantly older than those who did not. In phase 3, 62 consecutive patients were studied. There were 37 accidents in total, of which 35 were falls. Compared with the phase 2 study, there was no reduction in the proportion of patients who had a fall or other accident in phase 3, but significantly fewer falls resulted in any injury (p/0.05).

Conclusions: Although the interventions employed did not reduce the proportion of patients who had falls or other accidents, significantly fewer falls resulted in injuries.
Effectiveness of provision of outdoor mobility services and devices in the Netherlands
Authors: Wessels R D , de Witte L P , Jedeloo S , van den Heuvel W PM , van den Heuvel W JA
Published: May 2004

Objective: To answer the following questions: What are the problems encountered by people with outdoor mobility disabilities? What solutions are being offered to them in the Netherlands? How effective are these solutions? How responsive is the IPPA instrument (Individually Prioritized Problem Assessment)?

Design: Analysing the results of a follow-up study using the IPPA instrument.

Setting: The Dutch Service for the Disabled Act (SDA, in Dutch: WVG) provision system. This act is responsible for the provision of mobility aids and home adaptations.

Subjects: Fifty-nine people with outdoor mobility disabilities.

Interventions: The provision of outdoor mobility service and devices.

Main outcome measures: Effectiveness of provisions as measured using IPPA (i.e., the degree to which activities have become less difficult to perform), effect size of IPPA with this intervention.

Results: Problems identified by clients are very diverse and specific but can be classified fairly well on the basis of the International Classification of Functioning, Disability and Health (ICF); in the main, the solutions they are provided with are very similar and generic. Effectiveness is excellent at a group level, but insufficient for some at an individual level. The IPPA instrument is highly responsive in this setting. Most mobility problems respondents identified, although very individual and specific, were related to shopping, social visits or leisure activities. These specific sets of problems were solved using ‘standard’, generic solutions.

Conclusions: The Dutch provision system should be more ‘demand oriented’ and less ‘supply oriented’. IPPA turns out to be a useful, structured and individualoriented method to evaluate service delivery.
The effect of preoperative physiotherapy and education on the outcome of total hip replacement: a prospective randomized controlled trial
Authors: Gocen Zeliha , Sen Ayse , Unver Bayram , Karatosun Vasfi , Gunal Izge
Published: May 2004

Objective: To investigate the effects of preoperative physical therapy for patients undergoing total hip replacement.

Design: Prospective randomized controlled study.

Setting: Department of Orthopaedics and Traumatology in a university hospital.

Subjects: Sixty patients with osteoarthritis of the hip scheduled to receive total hip replacement were randomly assigned into two groups.

Interventions: Subjects in the study group received preoperative physiotherapy designed to strengthen the muscles of the upper and lower limbs and to improve range of motion of the hip, beginning from eight weeks before the operation. These patients also received an educational programme about living with a prosthesis. The control group received no preoperative physiotherapy or educational programme.

Main outcome measures: Patients were evaluated at baseline (study group only, eight weeks prior to operation), before surgery, at discharge, three months and two years postoperatively using Harris Hip Score, visual analogue scale and range at hip abduction.

Results: Although patients in the study group performed transfer activities earlier than the control group, there were no significant differences between the groups at discharge with regard to the improvement in Harris Hip Score ( p < 0.48) and hip adduction ( p < 0.97) and visual analogue scale at rest ( p < 0.54) and activity ( p < 0.89). At the latest follow-up (two years postoperatively) both groups had improved in Harris Hip Score, but rate of improvement between the groups was similar ( p < 0.05).

Conclusions: We conclude that the routine use of preoperative physiotherapy and education programme is not useful in total hip replacement surgery.
Percutaneous neuromuscular electrical stimulation (P-NMES) for treating shoulder pain in chronic hemiplegia. Effects on shoulder pain and quality of life
Authors: Renzenbrink Gerbert J , Ijzerman Maarten J
Published: May 2004

Objective: To evaluate the effect of percutaneous neuromuscular electrical stimulation (P-NMES) of the shoulder muscles on shoulder pain intensity and health-related quality of life in chronic hemiplegia.

Design: Prospective, open label design.

Setting: The outpatient services of a large teaching rehabilitation hospital in the Netherlands.

Subjects: Fifteen stroke survivors with chronic (> six months) hemiplegia and a therapy-resistant painful shoulder with subluxation. All patients suffered from clinically relevant shoulder pain, as assessed by a score of at least 4 out of 10 on a numerical rating scale. Shoulder subluxation was indicated by at least 1/2 fingerbreadth of glenohumeral separation on palpation.

Intervention: Six hours of P-NMES per day for a total of six weeks.

Main outcome measures: Shoulder pain (Brief Pain Inventory), shoulder subluxation (clinical and radiographic), shoulder pain-free external rotation (hand-held goniometer), motor impairment (Fugl-Meyer Motor test) and quality of life (SF-36) were assessed before treatment, after six weeks of intramuscular stimulation, at three months and six months follow-up.

Results: A significant reduction in pain was found on the Brief Pain Inventory. Pain reduction was still present at six months follow-up. All domains, in particular bodily pain, of the SF-36 showed improvement in the short term. After six months of follow-up, bodily pain was still strongly and significantly reduced, whereas social functioning and role physical demonstrated a nonsignificant improvement of more than 10% compared with baseline.

Conclusion: This pilot suggests that P-NMES potentially reduces shoulder pain in chronic hemiplegia. To establish the clinical value of P-NMES in treating hemiplegic shoulder pain a randomized controlled trial is needed.
Overview of primary progressive multiple sclerosis (PPMS): similarities and differences from other forms of MS, diagnostic criteria, pros and cons of progressive diagnosis
Authors: Thompson Alan
Published: May 2004

Patients with the primary progressive form of multiple sclerosis (PPMS) have a unique clinical course and demonstrate additional demographic and imaging features, which separate them from the relapsing/remitting form of the condition. Whether these features indicate a fundamental difference in the underlying patho genesis of the condition or simply reflect opposite ends of a clinical spectrum is unclear. What is clear, however, is that this form of MS provides a valuable model of progression, which has the potential to explain this most disabling component of the disease process. The lack of the hallmark relapses and remissions in PPMS poses diagnostic difficulties, some of which have been addressed by recently published diagnostic criteria. Following diagnosis, the need for information, specific to this form of MS, must be recognized and addressed.
The pathology of primary progressive multiple sclerosis
Authors: Lucchinetti Claudia , Bruck Wolfgang
Published: May 2004

The patho logical hallmark of chronic multiple sclerosis includes focal demyelination, gliosis, inflammation and axonal injury. There is limited information on whether these pathological features differ across the clinical pheno types of the disease (relapsing-remitting, secondary progressive, and primary progressive). This review will focus on the patho logical aspects of PPMS and pathogenic implications. A better understanding of the differences in PPMS pathology and patho genesis will lead to more effective treatment strategies.
Primary progressive multiple sclerosis: cerebrospinal fluid considerations
Authors: Freedman Mark S
Published: May 2004

Diagnosing the ‘primary progressive’ form of multiple sclerosis (PPMS) requires assurance that other conditions that might cause a chronic inflammatory neurodegenerative central nervous system (CNS) disease have been ruled out. Both imaging and pathological studies have shown that this form of MS tends to be less inflammatory compared with either the relapsing-remitting or secondary progressive types. There are therefore many conditions that cause a slowly progressive wasting of the C NS that might be confused with MS. The new MS diagnostic scheme has made the presence of ‘typical’ MS abnormalities in the cerebrospinal fluid (C SF) a mandatory first criterion, but there may well be individuals that still have PPMS even in the absence of a typical MS C SF. Here we explore what the C SF can tell about an individual’s disease process and outline the current state of the art in terms of C SF analysis. Used properly, the C SF can be very helpful in clarifying a diagnosis of PPMS.
Overview of London trial of intramuscular interferon-b1a in primary-progressive multiple sclerosis
Authors: Miller David H , Leary Siobhan M , Thompson Alan J
Published: May 2004

This short monograph describes the rationale, design and outcome of a pilot study of beta interferon in patients with primary progressive MS. A total of 50 patients were studied for 2 years using a randomized, double-blinded, placebo -controlled design. There was an emphasis on using MRI measures to evaluate outcome. The study showed that with the numbers studied, useful data could be obtained on safety and on efficacy on certain MRI measures. A larger study would be required to evaluate treatment on disability in this patient cohort and further work is needed to elucidate the relationship between quantitative MR and clinical measures over the longer term.
Mitoxantrone as a potential therapy for primary progressive multiple sclerosis
Authors: Stüve Olaf , Kita Mariko , Pelletier Daniel , Fox Robert J , Stone Jerome , Goodkin Donald E , Zamvil Scott S
Published: May 2004

Mitoxantrone (Novantrone®) was the first drug approved in western Europe and North A merica for treatment of secondary progressive multiple sclerosis (SPMS) and progressive relapsing MS (PRMS). Pharmacological properties of mitoxantrone, its role in SPMS, the study rational and design of an ongoing multi-centre, double blind, randomized, placebo -controlled phase 2 trial will be outlined in this article.
Multicentre proton magnetic resonance spectroscopy imaging of primary progressive multiple sclerosis
Authors: Narayana Ponnada A , Wolinsky Jerry S , Rao Sajja B , He Renjie , Mehta Meghana ,   PROMiSe Trial MRSI Group
Published: May 2004

Multicentre baseline proton magnetic resonance spectro scopic data on primary progressive multiple sclerosis (PPMS) patients are acquired and analysed, using automatic analysis software. The metabolite ratios did not differ from centre to centre. The average N-acetylaspar tate/creatine (NA A/C r) ratio in PPMS was significantly lower compared to normal controls. No significant differences were observed in this ratio between lesion-containing regions (LC R) and normal-appearing tissues (NAT). Strong lipid resonances, even in the absence of lesions, are observed in the both grey and white matter in these patients. These observations suggest extensive diffuse and/or microscopic pathology in PPMS. No significant correlation between any of the metabolite ratios and the Extended Disability Scale Score (EDSS) or with other MR measures such as lesion burden and enhancement volumes is observed.
Cervical cord atrophy assessment on magnetic resonance imaging: PRO MiSe trial
Authors: Li David , Laule Cornelia , Vavasour Irene , Vavasour Jeff , Whittall Kenneth , MacKay Alexander
Published: May 2004

The research plan to study the cervical cord in a subgroup of patients enrolled in the PRO Mise trial is described. Baseline and annual MRI evaluation will be performed to assess cervical cord area and quantitative T2 relaxation measurement changes at the C 2 level.
Phased mission modelling using fault tree analysis
Authors: La Band R A , Andrews J D
Published: May 2004

Many types of system operate for missions that are made up of several phases. For the complete mission to be a success, the system must operate successfully during each of the phases. Examples of such systems include an aircraft flight, and also many military operations for both aircraft and ships. An aircraft mission could be considered as the following phases: taxiing to the runway, take-off, climbing to the correct altitude, cruising, descending, landing and taxiing back to the terminal. Component failures can occur at any point during the mission, but their condition may only be critical for one particular phase. As such, it may be that the transition from one phase to another is the critical event leading to mission failure, and the component failures resulting in the system failure may have occurred during some previous phase. This paper describes a means of analysing the reliability of non-repairable systems that undergo phased missions. Fault tree analysis (FTA) has been used as a method for assessing the system performance. The results of the analysis are the system failure modes in each phase (minimal cut sets), the failure probability in each phase and the total mission unreliability. To increase the efficiency of the analysis, the fault trees constructed to represent the system failure logic are analysed using a modularization method. Binary decision diagrams (BDDs) are then employed to quantify the likelihood of failure in each phase.
Kramers—Kronig Relations and Sum Rules in Nonlinear Optical Spectroscopy
Authors: Peiponen Kai-Erik , Lucarini Valerio , Saarinen Jarkko J. , Vartiainen Erik
Published: May 2004

The full potential of the Kramers–Kronig relations and sum rules for nonlinear susceptibilities has unfortunately drawn relatively little attention in nonlinear optical spectra analysis. In this feature article a simple treatment of an anharmonic oscillator model in description of the nonlinear susceptibility of media and holomorphic properties of the nonlinear susceptibility were utilized. Using such concepts, conventional Kramers–Kronig, multiply-subtractive Kramers–Kronig, and generalized Kramers–Kronig dispersion relations can be derived. We demonstrate how in practice the variety of different Kramers–Kronig relations mentioned above, as well as various sum rules, can be applied in nonlinear optical spectra analysis. As an example we treat the third-harmonic wave generation spectrum from a polymer.
Fourier Transform Infrared—Attenuated Total Reflection Nitrate Determination of Soil Pastes Using Principal Component Regression, Partial Least Squares, and Cross-Correlation
Authors: Linker Raphael , Kenny Amit , Shaviv Avi , Singher Liviu , Shmulevich Itzhak
Published: May 2004

This paper investigates the use of Fourier transform infrared (FT-IR) attenuated total reflectance (ATR) spectroscopy as a fast and simple way for direct determination of nitrate concentration in soil pastes, which would assist precision fertilizer placement and reduce nitrate pollution. Eight types of soils are investigated, with nitrate concentrations ranging from 0 to 1000 ppm-N. The spectral region around the nitrate band (1300–1550 cm−1) is analyzed by (1) principal component regression (PCR), (2) partial least squares (PLS), and (3) cross-correlation with reference libraries that include spectra of pure ions and/or soils. The main obstacle to accurate nitrate measurement appears to be an interfering band present in calcareous soils. This band, which may be due to carbonate, is located around 1450 cm−1 and overlaps with the nitrate band centered around 1370 cm−1. For non-calcareous soils, and in particular for light sandy agricultural soils, PLS and cross-correlation with a reference library containing only spectra of ions in water give similar results (about 8 ppm-N on dry soil basis), while PCR leads to slightly poorer results. When calcareous soils are included in the analysis, the prediction errors are about twice as large. In this case, the best results are obtained using PLS, followed by PCR, while cross-correlation with reference libraries leads to poorer results.
Infrared Spectroscopy of OD Vibrators in Minerals at Natural Dilution: Hydroxyl Groups in Talc and Kaolinite, and Structural Water in Beryl and Emerald
Authors: de Donato Philippe , Cheilletz Alain , Barres Odile , Yvon Jacques
Published: May 2004

An infrared (IR) study of natural deuteration is conducted on minerals containing hydroxyl groups (talc and kaolinite) and channel-water-bearing minerals (beryl and emerald). In talc, the OD valence vibration is located at 2710 cm−1, corresponding to OD groups surrounded by 3 Mg atoms. In kaolinite, the OD valence vibrations are located at 2671 cm−1 (inner OD group), 2712, 2706, and 2700 cm−1 (three inner-surface OD groups). In beryl and emerald, natural deuteration of channel water is observed for the first time by infrared microspectroscopy. In beryl from Minas Gerais (Brazil), the OD profiles are characterized by four bands at 2735, 2686, 2672, and 2641 cm−1. In emeralds from Colombia and Brazil, the OD profiles are characterized by five or four bands, respectively, at 2816, 2737, 2685, 2673, and 2641 cm−1 (Colombia) and 2730, 2684, 2672, and 2640 cm−1 (Brazil). The band at 2816 cm−1 can be assigned to –OD or OD−, and bands at 2686–2684, 2673–2672, and 2641–2640 cm−1 can be assigned to type-I and type-II HOD molecules. The band at 2737–2730 cm−1 is partially disturbed by combination bands of the mineral. Such OD profiles are different from those obtained by artificial deuteration at higher OD dilution.
Quantitative Analysis of the in situ Fourier Transform Infrared Absorption and Emission Spectrum of Gas-Phase SiO (Δv = 1 and 2) Produced in Si—N—O Fiber Growth
Authors: Martin P. A. , Daum R. , Beil A. , Vogt U. , Vital A. , Graehlert W. , Leparoux M. , Hopfe V.
Published: May 2004

The in situ Fourier transform infrared (FT-IR) spectrum of gas-phase SiO produced in silicon oxynitride fiber growth has been quantitatively analyzed. Both absorption and emission FT-IR spectra at a spectral resolution of 0.5 cm−1 were produced from the reaction zone at 1450 °C. The fundamental and hot bands were observed with vibrational levels up to v = 7. For the purposes of quantitative analysis the individual vibration–rotation integrated line strengths for the three main isotopes, 28SiO, 29SiO, and 30SiO, were calculated based on ab initio quantum chemical calculations of the electric dipole moment function and the transition moment. Vibrational anharmonicity and Hermann–Wallis correction factors were also incorporated. From the line strengths at specific temperatures and the known Dunham coefficients, the absorbance spectrum was simulated with best fits giving the averaged SiO concentration in the 400 mm reaction zone of 1.0 × 1017 molecules/cm3. Such quantitative measurements demonstrate the power of in situ infrared (IR) spectroscopy combined with quantum chemical calculations. The rapid determination of synthetic calibration datasets for chemometric analysis can thus lead to correlation of gas-phase species concentrations with fiber growth properties and subsequently to real-time process control.
Part I: Surface-Enhanced Raman Spectroscopy Investigation of Amino Acids and Their Homodipeptides Adsorbed on Colloidal Silver
Authors: Podstawka Edyta , Ozaki Yukihiro , Proniewicz Leonard M.
Published: May 2004

Surface-enhanced Raman scattering spectra (SERS) were measured for various amino acids: L-methionine (Met), L-cysteine (Cys), L-glycine (Gly), L-leucine (Leu), L-phenylalanine (Phe), and L-proline (Pro) and their homodipeptides (Met-Met, Cys-Cys, Gly-Gly, Leu-Leu, Phe-Phe, and Pro-Pro) in silver colloidal solutions. The geometry and orientation of the amino acids or dipeptides on the silver surface, and their specific interaction with the surface, were deducted by detailed spectral analysis of the SERS spectra. This analysis has allowed us to propose the particular surface geometry of amino acids or dipeptides and also implied that C–C bonds were almost parallel to the surface, as evidenced by the absence of marker bands in the skeletal C–C stretching region of the spectra. Additionally, using “time-dependent” SERS measurements we solved an existing controversy regarding the binding specificity of Gly-Gly on the silver surface.
Part II: Surface-Enhanced Raman Spectroscopy Investigation of Methionine Containing Heterodipeptides Adsorbed on Colloidal Silver
Authors: Podstawka Edyta , Ozaki Yukihiro , Proniewicz Leonard M.
Published: May 2004

Surface-enhanced Raman scattering (SERS) spectra of methionine (Met) containing dipeptides: Met-X and X-Met, where X is: L-glycine (Gly), L-leucine (Leu), L-proline (Pro), and L-phenylalanine (Phe) are reported. Using pre-aggregated Ag colloid we obtained high-quality SERS spectra of these compounds spontaneously adsorbed on colloidal silver. Additionally, we measured Raman spectra (RS) of these heterodipeptides in a solid state as well as in acidic and basic solutions. The RS and SERS spectra of Met-X and X-Met presented in this work appear to be different. One of the most prominent and common features in the SERS spectra of all these dipeptides is a band in the 660–690 cm−1 range that is due to the C–S stretching, v(CS), vibration of Met. This suggests that all the abovementioned compounds adsorb on the silver surface through a thioether atom. On the other hand, the SERS spectra of X-Met show clearly that not only the S atom but also the carboxylate group interact with the colloid surface as manifested by the enhancement of bands in the 920–930 and 1380–1396 cm−1 regions. These bands are ascribed to the v(C–COO−) and vsym(COO−) vibrations, respectively. Additionally, a SERS spectrum of Phe-Met indicates that the interaction of the thioether atom, amine group, and aromatic side chain with the silver surface is favorable and may dictate the orientation and conformation of adsorbed peptide.
Further Investigations on a Poly(Vinyl Alcohol)— Polyelectrolyte Chemically Selective Optical Film
Authors: Paddock Jean R. , Zudans Imants , Heineman William R. , Seliskar Carl J.
Published: May 2004

The ionomer poly(vinylbenzyltrimethylammonium chloride) has been blended with cross-linked poly(vinyl alcohol) to form optically clear composites that can be covalently linked as thin films to oxide surfaces. Films are characterized using spectroscopic ellipsometry with refractive index ( n) and extinction coefficient ( k) data presented for wavelengths 300 to 1100 nm. A refractive index of 1.54 and average thickness of 709 nm are typical of an air dry film prepared by spin-coating. Dynamic in situ ellipsometry results for films exposed to 0.1 M KNO3 and 1.0 mM Fe(CN)6−3 are presented. Upon initial exposure to 0.1 M KNO3, an air dry film expands by about 160% and stabilizes in size and refractive index at about 18 hours. Ion exchange of film cationic groups with ferricyanide is marked by slight film contraction, presumably due to electrostatic crosslinking by the multivalent anion. These films are useful in the spectroelectrochemical sensor with our newly developed fluorescence detection mode, as demonstrated by results of the reversible incorporation of the fluorescent anion fluorescein.
Time-Resolved Fluorescence Spectroscopic Study of Crude Petroleum Oils: Influence of Chemical Composition
Authors: Ryder Alan G.
Published: May 2004

The fluorescence of crude petroleum oils is sensitive to changes in chemical composition and many different fluorescence methods have been used to characterize crude oils. The use of fluorescence lifetimes to quantitatively characterize oil composition has practical advantages over steady-state measurements, but there have been comparatively few studies in which the lifetime behavior is correlated with gross chemical compositional data. In this study, the fluorescence lifetimes for a series of 23 crude petroleum oils with American Petroleum Institute (API) gravities of between 10 and 50 were measured at several emission wavelengths (450–785 nm) using a 380 nm light emitting diode (LED) excitation source. It was found that the intensity average fluorescence lifetime (τ̄) at any emission wavelength does not correlate well with either API gravity or aromatic concentration. However, it was found that τ̄ is strongly negatively correlated with both the polar and sulfur concentrations and positively correlated with the corrected alkane concentration. This indicates that the fluorescence behavior of crude petroleum oils is governed primarily by the concentration of quenching species. All the strong lifetime–concentration correlations are nonlinear and show a high degree of scatter, especially for medium to light oils with API gravities of between 25 and 40. The degree of scatter is greatest for oils where the concentrations (wt %) of the polar fraction is ∼10 ± 4%, the asphaltene component is ∼1 ± 0.5%, and sulfur is 0.5 ± 0.4%. This large degree of scatter precludes the use of average fluorescence lifetime data obtained with 380 nm excitation for the accurate prediction of the common chemical compositional parameters of crude petroleum oils.
Influence of Wavelength-Shifted Calibration Spectra on Multivariate Calibration Models
Authors: Vogt Frank , Booksh Karl
Published: May 2004

Multivariate calibration models are sensitive to wavelength shifts in calibration spectra as such disturbances are linearly independent from unshifted spectra and increase the calibration model's dimension. However, if wavelength shifts included in the calibration model are random, the predictability of the model is not improved. On the contrary, overfitting is introduced, thereby increasing the prediction error. Because calibration spectra are defined to be error free and are the only available data at that point, there is no analytical way to find out that the calibration model is erroneous. This study gives a mathematical explanation of how the model's dimension is increased by wavelength shifts and that the additional basis vectors, principal components for instance, possess derivative-shaped features. It is also demonstrated by means of an example that the reverse is not necessarily true. Hence, derivative-shaped features found in principal components are no indication of wavelength-shifted calibration spectra. A method is presented for analyzing calibration spectra for such shifts. The algorithm takes advantage of the fact that artificial shift compensations of true shifts increase the similarity, i.e., correlation, of shifted spectra with respect to the remaining, unshifted spectra. Synthetic and experimental data are used to demonstrate and assess the performance of the algorithm. It is shown that wavelength shifts in calibration spectra can be detected and corrected if a small number of spectra are disturbed. Significant improvements of the prediction errors of chemometric calibration models can be achieved by means of this shift-correction algorithm.
Alveolar Epithelial Type I Cells Express β2-Adrenergic Receptors and G-protein Receptor Kinase 2
Authors: Liebler Janice M. , Borok Zea , Zhou Xian Li Beiyun , Sandoval Argelia J. , Kim Kwang-Jin , Crandall Edward D.
Published: May 2004

β2-Adrenergic agonists stimulate alveolar epithelial sodium (Na+) transport and lung fluid clearance. Alveolar type II (AT2) cells have been reported to express β2-adrenergic receptors (β2AR). Given the large surface area covered by alveolar type I (AT1) cells and their potential role in alveolar fluid removal, we were interested in learning if AT1 cells express β2AR as well. Because β2AR is potentially susceptible to desensitization by G-protein-coupled receptor kinase 2 (GRK2), we also undertook localization of GRK2. β2AR and GRK2 expression was evaluated in whole lung, isolated alveolar epithelial cells (AECs), and AECs in primary culture, and was localized to specific AEC phenotypes by immunofluorescence techniques. β2AR is highly expressed in AT1 cells. β2AR mRNA increases with time in culture as AT2 cells transdifferentiate towards the AT1 cell phenotype. Immunoreactive GRK2 is seen in both AT1 and AT2 cells in similar amounts. These data suggest that both AT1 and AT2 cells may contribute to the increased alveolar Na+ and water clearance observed after exposure to β2 adrenergic agents. Both cell types also express GRK2, suggesting that both may undergo desensitization of β2AR with subsequent decline in the stimulatory effects of β2-adrenergic agonists over time.
Immunohistochemical Study of Protein 4.1B in the Normal and W/Wv Mouse Seminiferous Epithelium
Authors: Terada Nobuo , Ohno Nobuhiko , Yamakawa Hisashi , Baba Takeshi , Fujii Yasuhisa , Zea Zagreb , Ohara Osamu , Ohno Shinichi
Published: May 2004

Cell-cell adhesion is crucial not only for mechanical adhesion but also for tissue morphogenesis. Protein 4.1B, a member of the protein 4.1 family named from an erythrocyte membrane protein, is a potential organizer of an adherens system. In adult mouse seminiferous tubules, protein 4.1B localized in the basal compartment, especially in the attaching region of spermatogonia and Sertoli cells. Protein 4.1B localization and appearance were not different in each spermatogenic stage. Developmentally, protein 4.1B was not detected at postnatal day 3 (P3), was diffusely localized at P15, and was found in the basal compartment during the third week. By double staining for protein 4.1B and F-actin, their localizations were shown to be different, indicating that protein 4.1B was localized in a region lower than the basal ectoplasmic specialization that formed the Sertoli–Sertoli junction. By electron microscopy, immunoreactive products were seen mainly on the membranes of Sertoli cells. In the W/Wv mutant mouse, the seminiferous epithelium had few germ cells. Protein 4.1B and β-catenin were not detected, although the basal ectoplasmic specialization was retained. These results indicate that protein 4.1B may be related to the adhesion between Sertoli cells and germ cells, especially the spermatogonium.
Expression and Characterization of Murine Hevin (SC1), a Member of the SPARC Family of Matricellular Proteins
Authors: Brekken Rolf A. , Sullivan Millicent M. , Workman Gail , Bradshaw Amy D. , Carbon Juliet , Siadak Anthony , Murri Carrie , Framson Paul E. , Sage E. Helene
Published: May 2004

Hevin, also known as SC1, MAST 9, SPARC-like 1, RAGS1 and ECM2, is a member of the SPARC-related family of matricellular proteins. Mouse hevin is 53% identical to mouse SPARC, and both proteins share a follistatin-like module and an extracellular Ca2+-binding (E-C) domain. SPARC functions as a modulator of cell-matrix interactions, a regulator of growth factor activity, a de-adhesive protein, and a cell cycle inhibitor. Although the functions of mouse hevin are unknown, its human orthologue has been shown to be de-adhesive for endothelial cells. We now report the production of recombinant mouse hevin in insect cells through the use of a baculoviral expression system and its purification by anion-exchange, size-exclusion chromatography, and isoelectric focusing. Furthermore, we have produced rat anti-hevin monoclonal antibodies (MAbs) that have been characterized by indirect and capture ELISAs, immunoblotting, immunoprecipitation, and immunohistochemistry (IHC). Recombinant hevin, present as a soluble factor or bound to tissue-culture plastic, inhibited the spreading of bovine aortic endothelial cells in vitro. IHC analysis of hevin in normal human and mouse tissues revealed a limited expression pattern in many tissues, with particularly dominant staining in dermis, ducts, vasculature, muscle, and brain. In lung and pancreatic tumor xenografts, we found distinct reactivity with MAbs that were selective for stromal cells, tumor cells, and/or endothelial cells. Although similar to SPARC in its anti-adhesive activities, hevin nevertheless exhibits a distinctive histological distribution that, in certain invasive tumors, is associated with desmoplasia.
Presence of Collagen IV in the Ciliary Zonules of the Human Eye
Authors: Los Leonoor I. , van der Worp Roelofje J. , van Luyn Marja J.A. , Hooymans Johanna M.M.
Published: May 2004

The ciliary zonules of the eye are composed of fibrillar and non-fibrillar components. Fibrils provide tensile strength and elasticity, whereas non-fibrillar components serve as a coating surrounding the fibrils. This coating behaves as a barrier to macromolecules. The present light and transmission electron microscopic (LM and TEM) study identified collagen IV as a novel component of this coating. Collagen IV was demonstrated by pre-embedding and postembedding immunohistochemical (IHC) techniques using monoclonal and polyclonal antibodies. The specificity of the polyclonal anticollagen IV antibody was verified by ELISA. (J Histochem Cytochem 52:789–795, 2004)
School is out
Authors: Fouz-Hernández Santiago
Published: May 2004

This article analyses the politics of gender representation in two well-known ‘coming-out’ British films of the 1990s: Hettie MacDonald’s Beautiful Thing (1996) and Simon Shore’s Get Real (1999). In contrast with similar gaythemed British youth
films of the previous decade - such as the Merchant- Ivory adaptation of E.M. Forster’s posthumous novel Maurice (1987) or Peter Saville’s The Fruit Machine (1988) - the films discussed here offer a comparatively positive picture of the ‘coming-out’ process
that has been criticized by some critics as unrealistic. Yet, similar rigid class and gender structures to those that permeated Forster’s early twentieth-century classic can be seen to have a direct influence on the more contemporary settings. Issues of gender stereotyping and the disparity
between queer and non-queer spaces, together with the potential queer politics of both films are also considered as evidence that these films are anything but simplistic or overoptimistic.
NR2B-Containing Receptors Mediate Cross Talk among Hippocampal Synapses
Authors: Scimemi Annalisa , Fine Alan , Kullmann Dimitri M. , Rusakov Dmitri A.
Published: May 2004

Under some conditions, synaptically released glutamate can exert long-range actions in the cortical microcircuitry. To what extent glutamate spillover leads to direct cross talk among individual synapses remains unclear. We recorded NMDAR-mediated EPSCs in acute hippocampal slices at 35°C by stimulating two independent pathways that converge on the same CA1 pyramidal cell. Activation of a conditioning pathway in the presence of the use-dependent blocker dizocilpine maleate (MK801) resulted in partial NMDA receptor (NMDAR) blockade in the other, silent pathway. This was accompanied by an increase in the rise time of the EPSCs in the conditioning (although not the silent) pathway, implying an increase in diffusional distance from release site to NMDARs. We estimated that up to ∼30% of NMDARs contributing to EPSCs were activated by glutamate released from multiple synaptic sources; however, NMDAR-mediated synaptic cross talk was undetectable when NR2B subunit-containing receptors were blocked (but could be rescued by blocking glutamate uptake). We propose that NR2B-containing NMDARs can detect glutamate arising from multiple synapses, whereas NR2A-containing NMDARs only normally mediate direct synaptic transmission. These NMDAR isoforms thus play complementary roles in sensing global and local glutamate signals, respectively.
Group I Metabotropic Glutamate Receptors Inhibit GABA Release at Interneuron-Purkinje Cell Synapses through Endocannabinoid Production
Authors: Galante Micaela , Diana Marco A.
Published: May 2004

Actions of endocannabinoids in the cerebellum can be demonstrated following distinct stimulation protocols in Purkinje cells. First, depolarization-induced elevations of intracellular Ca2+ lead to the suppression of neurotransmitter release from both inhibitory and excitatory afferents. In another case, postsynaptic group I metabotropic glutamate receptors (mGluRs) trigger a strong inhibition of the glutamatergic inputs from parallel and climbing fibers. Both pathways involve endocannabinoids retrogradely acting on type 1 cannabinoid receptors (CB1Rs) at presynaptic terminals. Here, we show that group I mGluR activation also depresses GABAergic transmission at the synapses between molecular layer interneurons and Purkinje cells. Using paired recordings, we found that application of the group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine reduced the evoked IPSCs in Purkinje cells. This effect was independent of postsynaptic Ca2+ increases and was completely blocked by a CB1R antagonist.

Experiments performed with the GTP-analogues GDP-βS and GTP-γS provided evidence that endocannabinoids released after G-protein activation can also inhibit GABAergic inputs onto nearby, unstimulated Purkinje cells. Block of the enzymes DAG lipase or phospholipase C reduced the group I mGluR-dependent inhibition, suggesting that 2-arachidonyl glycerol could act as retrograde messenger. Finally, group I mGluR activation by brief bursts of activity of the parallel fibers induced a short-lived depression of spontaneous IPSCs via presynaptic CB1Rs. Our results reveal a mechanism with potential physiological importance, by which glutamatergic synapses induce an endocannabinoid-mediated inhibition of the GABAergic inputs onto Purkinje cells.
The Arg451Cys-Neuroligin-3 Mutation Associated with Autism Reveals a Defect in Protein Processing
Authors: Comoletti Davide , De Jaco Antonella , Jennings Lori L. , Flynn Robyn E. , Gaietta Guido , Tsigelny Igor , Ellisman Mark H. , Taylor Palmer
Published: May 2004

The neuroligins are a family of postsynaptic transmembrane proteins that associate with presynaptic partners, the β-neurexins. Neurexins and neuroligins play a critical role in initiating formation and differentiation of synaptic junctions. A recent study reported that a mutation ofneuroligin-3(NL3), an X-linked gene, was found in siblings with autistic spectrum disorder in which two affected brothers had a point mutation that substituted a Cys for Arg451. To characterize the mutation at the biochemical level, we analyzed expression and activity of the mutated protein. Mass spectrometry comparison of the disulfide bonding pattern between the native and the mutated proteins indicates the absence of aberrant disulfide bonding, suggesting that the secondary structure of the mutated protein is conserved. However, the mutation separately affects protein expression and activity. The Cys mutation causes defective neuroligin trafficking, leading to retention of the protein in the endoplasmic reticulum. This, in turn, decreases the delivery of NL3 to the cell surface. Also, the small fraction of protein that reaches the cell membrane lacks or has markedly diminished β-neurexin-1 (NX1β) binding activity. Other substitutions for Arg451 allow for normal cellular expression but diminished affinity for NX1β. Our findings reveal a cellular phenotype and loss of function for a congenital mutation associated with autistic spectrum disorders.
Independent Functions of hsp90 in Neurotransmitter Release and in the Continuous Synaptic Cycling of AMPA Receptors
Authors: Gerges Nashaat Z. , Tran Irwin C. , Backos Donald S. , Harrell Jennifer M. , Chinkers Michael , Pratt William B. , Esteban José A.
Published: May 2004

The delivery of neurotransmitter receptors into synapses is essential for synaptic function and plasticity. In particular, AMPA-type glutamate receptors (AMPA receptors) reach excitatory synapses according to two distinct routes: a regulated pathway, which operates transiently during synaptic plasticity, and a constitutive pathway, which maintains synaptic function under conditions of basal transmission. However, the specific mechanisms that distinguish these two trafficking pathways are essentially unknown. Here, we evaluate the role of the molecular chaperone hsp90 (heat shock protein 90) in excitatory synaptic transmission in the hippocampus. On one hand, we found that hsp90 is necessary for the efficient neurotransmitter release at the presynaptic terminal. In addition, we identified hsp90 as a critical component of the cellular machinery that delivers AMPA receptors into the postsynaptic membrane. Using the hsp90-specific inhibitors radicicol and geldanamycin, we show that hsp90 is required for the constitutive trafficking of AMPA receptors into synapses during their continuous cycling between synaptic and nonsynaptic sites. In contrast, hsp90 function is not required for either the surface delivery of AMPA receptors into the nonsynaptic plasma membrane or for the acute, regulated delivery of AMPA receptors into synapses during plasticity induction (long-term potentiation). The synaptic cycling of AMPA receptors was also blocked by an hsp90-binding tetratricopeptide repeat (TPR) domain, suggesting that the role of hsp90 in AMPA receptor trafficking is mediated by a TPR domain-containing protein. These results demonstrate new roles for hsp90 in synaptic function by controlling neurotransmitter release and, independently, by mediating the continuous cycling of synaptic AMPA receptors.