bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular structures and electron distributions of higher-valent iron and manganese porphyrins: Density functional theory calculations and some preliminary open-shell coupled-cluster results
Authors: GHOSH ABHIK , VANGBERG TORGIL , GONZALEZ EMMANUEL , TAYLOR PETER
Published: August 2002

Density functional theory (DFT) calculations have been carried out for a variety of iron and manganese porphyrin complexes with metal oxidation states of +3 and above. In general, DFT gives very good descriptions of molecular structure and electron distributions, but appears less reliable in predictions of the relative energetics of different spin states of transition metal compounds. For instance, the fact that our calculations favor a quartet state for the five-coordinate complex, ( P ) FeCl , over a sextet state may be regarded as a shortcoming of currently available exchange-correlation functionals. This problem is corrected at the considerably more demanding spin-restricted open-shell coupled-cluster level of theory. For both +3 and +4 metal oxidation states, the manganese 3d subshells appear to be significantly more spatially contracted than the 3d subshells of analogous iron compounds. This appears to be a key factor underlying the anomalously low MnO stretching frequencies of Mn(IV) -oxo porphyrins, compared to the FeO stretching frequencies of Fe(IV) -oxo porphryins. Similarly, a dramatic ruffling-induced redistribution of unpaired spin density in the case of an A2 u-type iron(IV)-oxo porphyrin cation radical, recently reported by Deeth, has been ascribed to a metal( dxy)–porphyrin( a2 u) orbital interaction that becomes symmetry-allowed on ruffling of the porphyrin ring. If the axial ligand in a compound I species is strongly basic such as imidazolate (e.g. horseradish peroxidase) or mercaptide (chloroperoxidase and cytochrome P450), it too can be strongly noninnocent and carry a significant unpaired electron spin population. Similarly, theoretical modeling of a synthetic 'perferryl' complex, reported by Morishima and co-workers, has revealed a noninnocent axial methoxide ligand.
Relationships between dinoflagellate cyst assemblages in surface sediment and hydrographic conditions in the Bering and Chukchi seas
Authors: Radi Taoufik , Vernal Anne de , Peyron Odile
Published: August 2002

Palynological analyses were performed on 52 surface sediment samples from the eastern part of the Bering Sea and Chukchi Sea in order to document the regional distribution of dinoflagellate cyst assemblages and their relationship with sea‐surface conditions. The assemblages present a relatively high species diversity (20 taxa are recovered routinely), especially in the Bering Sea, where they are dominated by Operculodinium centrocarpum and the cyst of Pentapharsodinium dalei accompanied mainly by Spiniferites elongatus s.l., Spiniferites ramosus, Impagidinium pallidum, Brigantedinium spp., Islandinium minutum, Selenopemphix quanta, Selenopemphix nephroides, Quinquecuspis concreta and the cyst of Polykrikos kofoidii. The percentages of the main taxa vary with latitude, and principal component analysis shows that the distribution of assemblages is closely related to hydrographic conditions, notably the seasonal duration of sea‐ice cover and the sea‐surface temperature in February. The dinoflagellate cyst assemblages from the Bering Sea differ significantly from those of subarctic seas of the North Atlantic, with respect to their species composition and relationships with sea‐surface conditions. In particular, the occurrence of the cyst of Polykrikos kofoidii and Quinquecuspis concreta and the positive correlation between the percentages of Operculodinium centrocarpum and the extent of sea‐ice, constitute peculiar features in the Bering Sea assemblages. Copyright © 2001 John Wiley & Sons, Ltd.
Late Weichselian and Holocene sediment flux and sedimentation rates in Andfjord and Vågsfjord, North Norway
Authors: Plassen Liv , Vorren Tore O.
Published: August 2002

Late Weichselian and Holocene sediment flux and sedimentation rates in a continental‐shelf trough, Andfjord, and its inshore continuation, Vågsfjord, North Norway, have been analysed. The study is based on sediment cores and high‐resolution acoustic data. Andfjord was deglaciated between 14.6 and 13 14C kyr BP (17.5 and 15.6 calibrated (cal.) kyr BP), the Vågsfjord basin before 12.5 14C kyr BP (14.7 cal. kyr BP), and the heads of the inner tributary fjords about 9.7 14C kyr BP (11.2 cal. kyr BP). In Andfjord, five seismostratigraphical units are correlated to a radiocarbon dated lithostratigraphy. Three seismostratigraphical units are recognised in Vågsfjord. A total volume of 23 km3 post‐glacial glacimarine and marine sediments was mapped in the study area, of which 80% are of Late Weichselian origin. Sedimentation rates in outer Andfjord indicate reduced sediment accumulation with increasing distance from the ice margin. The Late Weichselian sediment flux and sedimentation rates are significantly higher in Vågsfjord than Andfjord. Basin morphology, the position of the ice front and the timing of deglaciation are assumed to be the reasons for this. Late Weichselian sedimentation rates in Andfjord and Vågsfjord are comparable to modern subpolar glacimarine environments of Greenland, Baffin Island and Spitsbergen. Downwasting of the Fennoscandian Ice Sheet, and winnowing of the banks owing to the full introduction of the Norwegian Current, caused very high sedimentation rates in parts of the Andfjord trough at the Late Weichselian–Holocene boundary. Holocene sediment flux and sedimentation rates in Andfjord are about half the amount found in Vågsfjord, and about one‐tenth the amount of Late Weichselian values. A strong bottom current system, established at the Late Weichselian–Holocene boundary, caused erosion of the Late Weichselian sediments and an asymmetric Holocene sediment distribution. Copyright © 2002 John Wiley & Sons, Ltd.
Fourier transform Raman spectroscopic study of pigments present in decorative wallpapers of the middle nineteenth century from the Santa Isabel factory (Vitoria, Basque Country, Spain)
Authors: Castro K. , Rodríguez‐Laso M. D. , Fernández L. A. , Madariaga J. M.
Published: August 2002

One of the earliest wallpapers manufactured by the Santa Isabel factory (Vitoria, Basque Country, Spain) (1845) was found at the Torre de los Varona (near Vitoria) during restoration work on the building. As part of this cleaning and restoration work, the identification of the wallpaper's pigments was carried out by Fourier transform (FT) Raman spectroscopy. Fragments of paper were set in a sampler kit for planar surfaces. By moving the paper samples, it is possible to locate the laser beam's spot at the point that it is going to be analysed with a spatial resolution of about 0.5 mm. With this method it is possible to map a surface of several square centimetres without the need for an optical microscope. As FT‐Raman analysis is totally non‐destructive, the samples were restored and integrated with the whole wallpaper at the end of the analysis. Small particles of pigment were collected for the analysis of the pink and green colours by atomic absorption spectrometry (AAS). In both cases, the damage caused by the pigment sampling was minimal and non‐visible. BaSO4, CaCO3, Pb3O4, PbCrO4, PbO, Prussian Blue, gypsum and an organic black pigment were detected. It is important to take into account the laser beam's penetrative power in order to interpret the spectra correctly. The identification of only eight pigments to make 12 different colours, mostly in two different shades, shows the ability of the wallpaper manufacturer to create a rich palette at low cost. This type of primitive industrial decorative work has become real artwork that it is necessary to preserve and restore. Copyright © 2002 John Wiley & Sons, Ltd.
Malignant transformation of “benign” cystic mesothelioma of the peritoneum
Authors: González‐Moreno Santiago , Yan Hui , Alcorn Kirsten W. , Sugarbaker Paul H.
Published: August 2002

Background and Objectives

Peritoneal mesothelioma is being diagnosed with greater accuracy as a result of immunocytochemical analysis. The histological type of peritoneal mesothelioma has a great influence on the natural history of the disease. Benign cystic mesothelioma is a definite clinical entity; however, the absence of a uniform approach to treatment and a lack of long‐term follow‐up of patients seriously hinders an accurate assessment of the disease process.

Methods

The medical history of a patient with a diagnosis of benign peritoneal cystic mesothelioma followed for 10 years is presented. The medical literature of this disease is reviewed.

Results

The patient was a 36‐year‐old woman initially diagnosed with benign cystic peritoneal mesothelioma; however, after six surgical procedures with the aim of reducing the volume of intraperitoneal fluid and cysts, the disease developed into an aggressive, diffuse malignant mesothelioma. Involvement of abdominal incisions, invasion of lymph nodes, and invasion of the viscera occurred.

Conclusions

Peritoneal cystic mesothelioma is a disease in need of careful longitudinal studies in order to better define the clinical course of these patients. This case report along with a literature review suggests caution in the assessment of cystic mesothelioma as a benign process. This patient had a clear malignant transformation of benign cystic mesothelioma to an invasive and potentially lethal process. J. Surg. Oncol. 2002;79:243–251. © 2002 Wiley‐Liss, Inc.
Clear cell sarcoma: The Roswell Park experience
Authors: Finley J. William , Hanypsiak Bryan , Mcgrath Brian , Kraybill William , Gibbs John F.
Published: August 2002

Background and Objectives:

Clear cell sarcoma of the tendons and aponeuroses (CCSTA) is an aggressive, rare soft‐tissue tumor with approximately 300 reported cases. Although it appears to be histogenetically related to melanoma, its clinical behavior resembles soft tissue sarcoma with a propensity for lymph node metastases. We report our experience at a tertiary cancer center.

Methods:

Eight cases of CCSTA evaluated at Roswell Park Cancer Institute between 1970 and 1998 were reviewed retrospectively. Patient data analyzed included patient age, gender, anatomic location, size of tumor, development of local, regional and distant recurrence, and patient status at last follow up.

Results:

Six of eight patients were alive at 2 years, while three of seven patients were alive at 5 years. Of the patients alive with no evidence of recurrence, two had tumors of less than 2 cm, and the remaining patient had incomplete information regarding tumor size. Five patients recurred within 2 years of definitive surgical management. Four had tumors > 5 cm. All five patients progressed to metastatic disease at a median follow up of 20 months (range 1–108 months) following definitive surgical management and all eventually died of their disease at a median of 3 months (range 0–24 months) from presentation with metastatic disease. Four of five patients with lesions > 5 cm received adjuvant chemotherapy with intent to cure, but all eventually died of disease at 4, 22, 34, and 41 months from initial presentation.

Conclusions:

CCSTA is an aggressive tumor of the soft tissues. Early recognition and management are associated with an excellent long‐term prognosis. Tumors greater than 5 cm warrant aggressive surgical management and treatment, and are at high risk of the development of distant disease. Aggressive multiagent chemotherapy appeared to have no impact on outcome. Other adjuvant therapeutic options including immunotherapy should be investigated. J. Surg. Oncol. 2001; 77:16–20. © 2001 Wiley‐Liss, Inc.
Synergies in destination image management: a case study and conceptualisation
Authors: Laws Eric , Scott Noel , Parfitt Nick
Published: August 2002

This paper addresses the question of how operators and destination authorities work within a destination region, illustrating a method by which the problems resulting from different geographical scales and objectives of business units can be tackled through co‐operative marketing within a strong destination image. Following a review of the literature, a case study covering the research underpinning a cooperative marketing programme involving hotels in Port Douglas, Tropical North Queensland (TNQ) is presented. The research methodology is outlined. The policy implications of the findings for the State Tourist Organisation and for organisations involved in destination image management are considered, and a conceptual model of cooperative marketing at the destination level is proposed. Copyright © 2002 John Wiley & Sons, Ltd.
Kinetics and mechanism associated with the reactions of hydroxyl radicals and of chlorine atoms with 1‐propanol under near‐tropospheric conditions between 273 and 343 K
Authors: Cheema Shahbaz A. , Holbrook Kenneth A. , Oldershaw Geoffrey A. , Walker Raymond W.
Published: August 2002

Rate constants for the reactions of OH radicals and Cl atoms with 1‐propanol (1‐C3H7OH) have been determined over the temperature range 273–343 K by the use of a relative rate technique. The value of k(Cl + 1‐C3H7OH) = (1.69 ± 0.19) × 10−12 cm3 molecule−1 s−1 at 298 K and shows a small increase of 10% between 273 and 342 K. The value of k(OH + 1‐C3H7OH) increases by 14% between 273 and 343 K with a value of (5.50 ± 0.55) × 10−12 cm3 molecule−1 s−1 at 298 K, and further when combined with a single independent experimentally determined value at 753 K gives k(OH + 1‐C3H7OH) = 4.69 × 10−17T1.8 exp(422/T) cm3 molecule−1 s−1, which fits each data point to better than 2%. Two well‐established structure–activity relationships for H abstraction by OH radicals give accurate predictions of the rate constant for OH + 1‐C3H7OH, provided the β‐CH2 group is given an increased reactivity of a factor of about 2 over that for the structurally equivalent CH2 group in alkanes at 298 K.

A quantitative product analysis was carried out at 298 K for the Cl‐initiated photooxidation of 1‐C3H7OH, using both FTIR and gas chromatography. HCHO, CH3CHO, and C2H5CHO were the only major organic primary products observed, although HCOOH was found in much smaller amounts as a secondary product. A key characteristic of the analysis was that the initial values of the product ratio [CH3CHO]/[C2H5CHO] were effectively constant for NO pressures between 0.15 and 0.3 Torr, but fell by about 35% as the pressure fell to 0.0375 Torr. From a detailed consideration of the mechanism for the oxidation, it is suggested that C2H5CHO, CH3CHO (+HCHO), and 3 molecules of HCHO are formed uniquely from CH3CH2CHOH, CH3CHCH2OH, and CH2CH2CH2OH radicals, respectively. On this basis, use of the product yields gives the branching ratios of 56, 30, and 14% for Cl atom reaction at the α‐, β‐, and γ‐CH positions in 1‐C3H7OH at 298 K. Given the very low temperature coefficients involved, little change will occur over tropospheric temperature ranges. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 110–121, 2002
On‐site and off‐site effects of wind erosion on European light soils
Authors: Riksen M. J. P. M. , de Graaff J.
Published: August 2002

In intensively cultivated areas with light soils in Europe, wind erosion can have important on‐site and off‐site effects. In the framework of the EU research project Wind Erosion and European Light Soils (WEELS), an assessment has been made of these effects and of the order of magnitude of the damage and costs caused by these effects. An analysis is made of the land use and cropping in four selected sites, and farmers have provided information about the damage of wind erosion. This damage consists mainly of crop losses and additional inputs in the case of resowing. Detailed information from one of these sites shows that depending on the crop the average annual on‐site costs in high‐risk areas amount to about €60 per hectare. However, for sugar beet and oilseed rape the costs can be once in five years as much as €500 per hectare. Farmers are generally well aware of the erosion risk and do apply a variety of control measures. With these measures the average annual costs of wind erosion can be reduced significantly. Copyright © 2001 John Wiley & Sons, Ltd.
Adhesion of composite resins to enamel irradiated by the er:YAG laser: Application of the ultrasonic scaler on irradiated surface
Authors: Eguro Toru , Maeda Toru , Tanabe Midori , Otsuki Masahito , Tanaka Hisayoshi
Published: August 2002

Background and Objective

The clinical use of the Er:YAG laser in cavity preparation has become widespread. With respect to cavities prepared with the Er:YAG laser, restorations using composite resins and glass ionomer cements are common. The bond strength of current resin bonding systems to ground enamel is 14–30 MPa, whereas the strength to Er:YAG laser‐irradiated enamel, regardless of the use or non‐use of phosphoric acid etching is less than 10 MPa.

Study Design/Materials and Methods

In this investigation, an ultrasonic scaler was tested as a technique to increase the bond strength of composite resins to the Er:YAG irradiated enamel surface.

Results

The application of the ultrasonic scaler significantly increased bond strength.

Conclusions

The tensile bond strength in the groups treated with the ultrasonic scaler exhibited approximately twice the strength observed in groups treated with laser irradiation alone. Lasers Surg. Med. 28:365–370, 2001. © 2001 Wiley‐Liss, Inc.
Laser soldering of rat skin, using fiberoptic temperature controlled system
Authors: Simhon D. , Ravid A. , Halpern M. , Cilesiz I. , Brosh T. , Kariv N. , Leviav A. , Katzir A.
Published: August 2002

Background and Objective

Laser soldering of tissues is based on the application of a biological solder on the approximated edges of a cut. Our goal was to use laser soldering for sealing cuts in skin under temperature feedback control and compare the results with ones obtained using standard sutures.

Study Design/Materials and Methods

Albumin solder was applied onto the approximated edges of cuts created in rat skin. A fiberoptic system was used to deliver the radiation of a CO2 laser, to heat a spot near the cut edges, and to control the temperature. Laser soldering was carried out, spot by spot, where the temperature at each spot was kept at 65–70°C for 10 sec.

Results

The tensile strength of laser‐soldered cuts was measured after 3–28 days postoperatively and was found comparable to that of sutured cuts. Histopathological studies showed no thermal damage and less inflammatory reaction than that caused by standard sutures (P = 0.04).

Conclusions

Temperature controlled laser soldering of cuts in rat skin gave strong bonding. The cosmetic and histological results were very good, in comparison to those of standard sutures. Lasers Surg. Med. 29:265–273, 2001. © 2001 Wiley‐Liss, Inc.
A p21waf1‐independent pathway for inhibitory phosphorylation of cyclin‐dependent kinase p34cdc2 and concomitant G2/M arrest by the chemopreventive flavonoid apigenin
Authors: McVean Maralee , Weinberg Wendy C. , Pelling Jill C.
Published: August 2002

Apigenin, a nonmutagenic flavonoid, has been shown to inhibit ultraviolet light–induced skin tumorigenesis when topically applied to mouse skin. Our previous studies have shown that apigenin treatment of cultured mouse keratinocytes induces G2/M arrest accompanied by an increase in p53 protein stability and expression of p21waf1. In this study, we determined whether the G2/M arrest induced by apigenin was dependent upon the presence of the cyclin dependent kinase inhibitor p21waf1. We exposed WWT.8 (p21waf1 wild‐type) and WKO.16 (p21waf1 null) mouse keratinocytes to various doses of apigenin for 24 h and observed G2/M arrest in both cell lines, thereby establishing that the apigenin‐induced G2/M arrest was p21waf1 independent. A 4‐h treatment with apigenin induced increases in p53 protein level by sixfold and tenfold in the WWT.8 p21waf1 wild‐type cells and WKO.16 p21waf1 null cells, respectively. After 24 h in WWT.8 cells, p21waf1 protein also was induced in a dose‐dependent manner, but it was not expressed in WKO.16 keratinocytes. We then measured the effect of apigenin treatment on the mammalian homologue of the yeast cdc2 gene (p34cdc2) cyclin‐dependent kinase and cyclin B1 (cycB1), because these proteins complex to regulate G2/M progression. Apigenin treatment decreased the protein level of p34cdc2, and p34cdc2 kinase activity was inhibited in both p21waf1+/+ and p21waf1−/− cell lines by approximately 40%. The inhibition of p34cdc2 kinase activity by apigenin treatment correlated with increasing levels of p34cdc2 phosphorylation at Tyr15, a site in the p34cdc2 kinase that undergoes inhibitory phosphorylation by Wee1 kinase. Apigenin treatment also had no effect on the protein level or activity of the competing phosphatase, cdc25c, which dephosphorylates p34cdc2 kinase at Tyr15. Apigenin had little effect on the accumulation of cycB1 protein. These results supported the conclusion that G2/M arrest induced by apigenin was accompanied by inhibition of the p34cdc2 cyclin‐dependent kinase protein level and activity in a p21waf1‐independent manner. © 2002 Wiley‐Liss, Inc.
Hypermethylation of the tumor necrosis factor receptor superfamily 6 (APT1, Fas, CD95/Apo‐1) gene promoter at rel/nuclear factor κB sites in prostatic carcinoma
Authors: Santourlidis Simon , Warskulat Ulrich , Florl Andrea R. , Maas Simone , Pulte Thomas , Fischer Johannes , Müller Wolfram , Schulz Wolfgang A.
Published: August 2002

DNA hypermethylation of CpG‐rich promoter sequences is associated with tumor suppressor gene inactivation in many human cancers, notably in carcinoma of the prostate and the urinary bladder. Recently, the mouse homologue of the tumor necrosis factor receptor superfamily 6 (TNFRSF6) gene was reported to be inactivated by DNA methylation in various cell types. The Fas (CD95, Apo‐1) protein encoded by the TNFRSF6 gene is an important mediator of apoptosis, which also is downregulated in different types of human carcinoma. We therefore investigated the methylation of the TNFRSF6 promoter in prostatic and bladder carcinomas and cell lines. In a restriction enzyme polymerase chain reaction assay, four of 32 prostatic carcinomas and three of 15 advanced bladder carcinomas showed evidence of hypermethylation at the rel/nuclear factor κB (NFκB) binding sites essential for promoter activity. The DU145 cell line derived from a metastasis of a prostate carcinoma also displayed hypermethylation in this assay, which was confirmed by bisulfite sequencing. Treatment of DU145 cells with the methylation inhibitor deoxyazacytidine slightly increased Fas protein expression, as detected by flow cytometry analysis. In vitro methylation of the TNFRSF6 promoter at the rel/NFκB sites completely abolished its activity. Thus, although the TNFRSF6 gene can be inactivated efficiently by DNA methylation, hypermethylation occurs neither frequently nor extensively in human carcinomas and appears to play a limited role in downregulation of Fas expression. © 2001 Wiley‐Liss, Inc.
Field validation of a method for population screening of parkinsonism
Authors: Sevillano Maria Dolores , de Pedro‐Cuesta Jesús , Duarte Jacinto , Clavería Luis Erik
Published: August 2002

We sought to validate an instrument and two application procedures for screening for prevalence of parkinsonism in conjunction with a door‐to‐door survey in Cantalejo, Spain. Residents in Cantalejo aged 40 years or older were assigned to three groups specifically designed to optimise case‐finding and cost/efficiency. A nine‐item questionnaire aimed at identifying parkinsonism‐related symptoms was administered and collected door‐to‐door by laymen and repeated by specialists at a medical facility before neurological examination. Diagnoses were then established and confirmed after a 3‐year follow‐up. Different indices for and concordance of answers were studied for both applications in groups of 25 individuals with parkinsonism. The scoring procedure was updated using the prevalence community sample of parkinsonism. Whereas the application administered by laymen showed, using the same cut‐off scores, a higher sensitivity for parkinsonism than that administered by trained personnel, it yielded a lower positive predictive value for parkinsonism diagnosed during the study, i.e., at a 30‐point cut‐off (96% vs. 80% and 15% vs. 76%, respectively). Concordance was ≥64% with κ ≥0.316 and P ≤0.031 for six questions. Instrument sensitivity, determined by different cut‐off scores, had a high impact on PD detection, observed M/F ratio, severity, and mean age at onset. Choice of screening method or application can considerably affect prevalence measurements and disease natural history parameters described in PD surveys. © 2002 Movement Disorder Society
Sudden daytime sleep onset in Parkinson's disease: Polysomnographic recordings
Authors: Tracik F. , Ebersbach G.
Published: August 2002

Sleep attacks in Parkinson's disease are controversially discussed. This paper describes a patient with Parkinson's disease suffering from sudden, irresistible onset of sleep during daytime. Medication included levodopa, entacapone, budipine, and cabergoline. Introduction of entacapone was the last therapeutic action preceding onset of sleep events, suggesting increased bioavailabilty of levodopa to be provocative in this case. In contrast to previous cases, the sudden sleep events were witnessed by clinical staff members and documented by polysomnographic and video recordings. Polysomnography during these sleep events remarkably showed abrupt slowing of EEG‐background activity and occurrence of slow eye movements and K‐complexes within 10 seconds after stable wakefulness. Within 60 seconds, the polysomnographic pattern proceeded to stable sleep stage 2. © 2001 Movement Disorder Society.
Frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP‐17): PPND family. A longitudinal videotape demonstration
Authors: Wszolek Zbigniew K. , Kardon Randy H. , Wolters Erik Ch. , Pfeiffer Ronald F.
Published: August 2002

Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP‐17), characterized by an autosomal dominant inheritance pattern, has recently been recognized as a distinct entity that can display a confusingly broad clinical phenotype. The pallido‐ponto‐nigral degeneration (PPND) variant is the prototypical example of the parkinsonism‐predominant pattern of FTDP‐17. A longitudinal videotape demonstration of the clinical progression of this entity in a single individual, along with brief videotape segments from three additional affected individuals, is presented in order to facilitate recognition of this disorder. © 2001 Movement Disorder Society.
A new artificial nerve graft containing rolled Schwann cell monolayers
Authors: Hadlock Tessa A. , Sundback Cathryn A. , Hunter Daniel A. , Vacanti Joseph P. , Cheney Mack L.
Published: August 2002

This study hypothesized that introducing high numbers of Schwann cells in monolayers via a novel rolled graft architecture would promote robust nerve regeneration. The objective was to place adherent Schwann cells in artificial nerve grafts and to assess regeneration through the Schwann cell–laden grafts compared with that through acellular grafts and autografts. Schwann cells were isolated from neonatal Fisher rats. Small intestinal submucosa (SIS) was harvested from adult Fisher rats, cut into 7 mm × 8 cm pieces, and pinned out. Schwann cells were plated onto the strips, allowed to reach confluence, and subsequently rolled into a laminar structure and implanted across a 7‐mm gap in the rat sciatic nerve (n = 12). Control animals received SIS conduits without Schwann cells (n = 11) or autograft repair (n = 12). At 10.5 weeks, functional regeneration through the Schwann cell–laden grafts, measured by both sciatic function index and extensor postural thrust testing, exceeded that through the cell‐free grafts and approached that achieved through autografts. These results highlight the role of Schwann cells in nerve regeneration. Regenerative results approaching autograft levels in the Schwann cell–laden group suggest that this methodology may ultimately be useful in clinical nerve repair. © 2001 Wiley‐Liss, Inc. Microsurgery 21:96–101 2001
Long‐acting morphine for pain control in paediatric oncology
Authors: Zernikow Boris , Lindena Gabriele
Published: August 2002

Background

Guidelines for treatment of paediatric cancer pain recommend the usage of long‐acting morphine. However, published paediatric experience with this drug is restricted to 147 children not systematically evaluated, and thus insufficient. We aimed to systematically analyse the age‐dependent effects and adverse effects of long‐acting morphine in paediatric cancer patients.

Procedure

Ninety‐five children aged 1 to 19 years were enrolled in a collaborative retrospective study conducted over seven‐and‐a‐half years. Pain was scored according to a numeric rating scale (NRS, range 0 to 5), and the corresponding medication was recorded.

Results

In 83 children documentation period started during morphine treatment (71, oral long‐acting; 1, rectal; 11, IV). Mean oral/equivalent morphine starting dose was 1.3 mg/kgbw/d (SD 0.9). Mean end dose was 2.8 mg/kgbw/d (SD 2.7). Infants aged < 7 years received the highest average dose (2.6 mg/kgbw/d, SD 2.8), while patients > 12 years received the lowest dose (1.4 mg/kgbw/d, SD 1.1). Median pain intensity decreased from score 1.0 (mean 1.2) NRS at the beginning to 0 (mean 0.6) NRS at the end. The proportion of patients scoring > 2 NRS (severe or most severe pain) under morphine treatment decreased from 26 to 12% (P = 0.08). In children > 12 years pruritus was frequently observed (23% of patients). In all age groups, there were no severe adverse effects during the study period.

Conclusions

In paediatric haematology/oncology, pain control by oral long‐acting morphine proved to be safe and effective even in the very young patients. The pharmacological properties of long‐acting morphine are ideally suited for paediatric use, combining efficacy and compatibility. Med. Pediatr. Oncol. 36:451–458, 2001. © 2001 Wiley‐Liss, Inc.
Cloning of brain aromatase gene and expression of brain and ovarian aromatase genes during sexual differentiation in genetic male and female Nile tilapia Oreochromis niloticus
Authors: Kwon Joon Yeong , McAndrew Brendan J. , Penman David J.
Published: August 2002

A brain aromatase gene was identified from the Nile tilapia Oreochromis niloticus. The cDNA sequence of this gene differed from that of the ovarian aromatase gene previously reported from this species. Tissue specific expression for both brain and ovarian aromatase genes was examined in the tissues of adult tilapia. Brain aromatase mRNA was expressed in the brain, kidney, eye, ovary, and testis, but not in the liver and spleen. Ovarian aromatase mRNA was expressed in the brain, spleen, ovary, and testis but not in the eye, kidney, and liver. Differential aromatase gene expression between the sexes was investigated in all‐male (XY) and all‐female (XX) groups of tilapia fry from fertilisation throughout the sexual differentiation period. Semi‐quantitative RT‐PCR analysis revealed that the initiation of expression of both aromatase genes lay between 3 and 4 dpf (days post fertilisation) in both sexes. The level of brain aromatase mRNA gradually increased throughout the period studied with little difference between the sexes. This contrasted with marked sexual dimorphism of ovarian aromatase mRNA expression. In females, the expression level was maintained or increased gradually throughout ontogeny, while the level in males was dramatically down‐regulated between 15 and 27 dpf. Subsequently, the level of ovarian aromatase mRNA expression fluctuated slightly in both sexes, with the expression in females always being higher than in males. These findings clearly suggest that ovarian aromatase plays a decisive role in sexual differentiation in this species and that this is achieved by down‐regulation of the expression of this gene in males. Mol. Reprod. Dev. 59: 359–370, 2001. © 2001 Wiley‐Liss, Inc.
Single‐coil arterial spin‐tagging for estimating cerebral blood flow as viewed from the capillary: Relative contributions of intra‐ and extravascular signal
Authors: Ewing James R. , Cao Yue , Fenstermacher Joseph
Published: August 2002

The single‐capillary model was applied to the exchange microvessels for water in the cerebral parenchyma and used to calculate blood‐to‐brain flux of water; the theory of the steady‐state arterial spin‐tagging (AST) technique for estimating cerebral blood flow (CBF) was revised to incorporate the presence of both extravascular (tissue) and capillary signal. A crucial element of the single‐coil AST experiment is that magnetization transfer (MT) shortens the effective T1 of the extravascular water, making it one‐quarter that of the T1 of capillary blood. Furthermore, the mean capillary transit time is on the order of the T1 of the extravascular water. The single‐coil AST experiment is distinguished from other methods which use water as an indicator for measurement of CBF in that the (flow‐dependent) populations of inverted protons in the intra‐ and extravascular compartments can be nearly equal for normal physiological conditions. The following questions are considered: Is single‐coil AST contrast linear in resting CBF? Is contrast in the single‐coil AST technique likely to be linear under changes in CBF in normal tissue? Is the contrast likely to be linear in such common pathologies as stroke and cerebral tumor? We demonstrate that, if the population of inverted protons in the microvessels is included in the experiment, the voxel population of inverted protons will be approximately linear with flow across a broad range of flow values. We predict that the single‐coil AST experiment will systematically overestimate resting CBF for flows in the normal range, that changes in CBF in normal tissue will produce an approximately linear response in AST measurement, and, finally, we predict the operating characteristics of the measurement in common cerebral pathologies. Magn Reson Med 46:465–475, 2001. © 2001 Wiley‐Liss, Inc.
The natural history of long thoracic and spinal accessory neuropathies
Authors: Friedenberg Scott M. , Zimprich Todd , Harper C. Michel
Published: August 2002

A cohort of 106 patients with electrodiagnostically confirmed long thoracic neuropathy (50 patients) or spinal accessory neuropathy (56 patients) seen at the Mayo Clinic over a 22‐year period were retrospectively studied to better understand the natural history of these disorders and to determine the role of electrodiagnostic testing in predicting prognosis. Mean follow‐up was 48 and 50 months, respectively. Good functional recovery was generally observed regardless of the results of electrodiagnostic studies, but improvement in the amplitude of the spinal accessory compound muscle action potential on serial nerve conduction studies tended to predict a good outcome. No electrodiagnostic findings correlated with poor outcome. Traumatic neuropathies generally did worse than neuropathies of other causes. In spinal accessory neuropathies, involvement of the dominant limb, scapular winging, and impaired arm elevation were associated with a poor outcome. Our data suggest that, contrary to other focal neuropathies, the electrodiagnostic findings do not predict functional outcome in these neuropathies. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
The clique partitioning problem: Facets and patching facets
Authors: Oosten Maarten , Rutten Jeroen H. G. C. , Spieksma Frits C. R.
Published: August 2002

The clique partitioning problem (CPP) can be formulated as follows: Given is a complete graph G = (V, E), with edge weights wij ∈ ℝ for all {i, j} ∈ E. A subset A ⊆ E is called a clique partition if there is a partition of V into nonempty, disjoint sets V1,…, Vk, such that each Vp (p = 1,…, k) induces a clique (i.e., a complete subgraph), and A = ∪ {{i, j}|i, j ∈ Vp, i ≠ j}. The weight of such a clique partition A is defined as Σ{i,j}∈A wij. The problem is now to find a clique partition of maximum weight. The clique partitioning polytope P is the convex hull of the incidence vectors of all clique partitions of G. In this paper, we introduce several new classes of facet‐defining inequalities of P. These suffice to characterize all facet‐defining inequalities with right‐hand side 1 or 2. Also, we present a procedure, called patching, which is able to construct new facets by making use of already‐known facet‐defining inequalities. A variant of this procedure is shown to run in polynomial time. Finally, we give limited empirical evidence that the facet‐defining inequalities presented here can be of use in a cutting‐plane approach for the clique partitioning problem. © 2001 John Wiley & Sons, Inc.
Agonists cause endocytosis of nicotinic acetylcholine receptors on cultured myotubes
Authors: St. John Paul A. , Gordon Herman
Published: August 2002

Regulated trafficking of neurotransmitter receptors in excitable cells may play an important role in synaptic plasticity. In addition, agonist‐induced endocytosis of nicotinic acetylcholine receptors (nAChRs) in particular might be involved in nicotine tolerance and addiction. The existing evidence concerning regulated internalization of cell‐surface nAChRs is indirect and equivocal, however. In the present study, radioligand binding and fluorescence microscopy were used to show that agonists cause substantial endocytosis of nAChRs on cultured myotubes. Exposure to carbachol or nicotine caused a decrease in the intensity of fluorescent labeling of clusters of cell‐surface nAChRs that was blocked by low temperature. Overall, myotubes exposed to carbachol or nicotine bound 50–70% less [125I]‐α‐bungarotoxin on the cell surface than untreated cells. The effect of carbachol was significant within 5 min, increased progressively for at least 4 h, and had a sensitivity of 100 nM or less. Exposure to carbachol caused the appearance or dramatic expansion of an intracellular pool of nAChRs, which were localized to discrete, largely perinuclear structures. A pulse‐chase labeling protocol allowed the selective labeling and localization of nAChRs that had been internalized from the cell surface. In untreated cells, very little internalization of nAChRs occurred over a period of 3 h, indicating that constitutive endocytosis of receptors over this period was minimal. Exposure to carbachol, however, caused a dramatic increase in the endocytosis of nAChRs. These results provide direct evidence that agonists, including the tobacco alkaloid nicotine, can cause substantial endocytosis of cell‐surface nAChRs. © 2001 John Wiley & Sons, Inc. J Neurobiol 49: 212–223, 2001
Higher‐order hybrid‐mixed axisymmetric thick shell element for vibration analysis
Authors: Kim Jin Gon , Kim Yoon Young
Published: August 2002

In this study, we present free vibration analysis of shells of revolution using the hybrid‐mixed finite element. The present hybrid‐mixed element, which is based on the modified Hellinger–Reissner variational principle, employs consistent stress parameters corresponding to cubic displacement polynomials with additional nodeless degrees to resolve the numerical difficulties due to the spurious constraints. The stress parameters are eliminated and the nodeless degrees are condensed out by the Guyan reduction. Several numerical examples show that the present element with cubic displacement interpolation functions and consistent quadratic stress functions is highly accurate for the free vibration analysis of shells of revolution, especially for higher vibration modes. Copyright © 2001 John Wiley & Sons, Ltd.
Complexity in local stakeholder coordination: decentralization and community water management in Northern Ghana
Authors: Jackson Edward T. , Gariba Sulley
Published: August 2002

Stakeholder coordination is a prominent theme in current development discourse. Experience with decentralization and community water management in northern Ghana highlights the complexities of coordinating stakeholders at the local level. In this case, roles and responsibilities must be clarified between legislated sub‐district structures on the one hand, and civic water groups on the other. This is especially important with regard to resolving which party should collect revenues and manage assets and expenditures in the water sector. The key mechanism for addressing these issues is the District Assembly, which is empowered under the decentralization law to coordinate stakeholders, both ‘horizontally’, across social actors, and ‘vertically’, between the national and sub‐district levels. While such local‐level dynamics are indeed complex and challenging, they are at the same time probably more amenable to at least medium‐term resolution than stakeholder competition issues at the national level. Copyright © 2002 John Wiley & Sons, Ltd.
The effect of ionic strength on the viscosity of sodium alginate solution
Authors: Zhang Hucheng , Wang Hanqing , Wang Jianji , Guo Ruifang , Zhang Qingzhi
Published: August 2002

The viscosities of aqueous sodium alginate solutions were measured in different NaCl concentrations (C
s) at 298 K. Based on the Odijk–Skolnick–Fixman theories, the electrostatic persistence lengths were calculated for various ionic strengths. The intrinsic persistence length of sodium alginate in solution was determined to be 125 Å by the method suggested by Odijk. In the region of $\hbox{C}_{\rm S}^{-1/2}> 6.5$, the increase in intrinsic viscosity, [η], for sodium alginate on decreasing the C
s is due to the larger contribution of electrostatic persistence length to the total persistence length, and the departure of [η]
calc from [η]
expl is attributed to the variation of the Flory Φ constant with ionic strength. A peak was observed in the plot of reduced viscosity v. sodium alginate concentration at a constant low ionic strength. As in the treatment of Rinaudo et al., this maximum in reduced viscosity is attributed to a preferential intermolecular distance. The roles of electrostatic persistence length, the critical inter‐rod spacing and the effect of added salt concentration on this maximum are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Automated complete slide digitization: a medium for simultaneous viewing by multiple pathologists
Authors: Leong F. J. W‐M. , McGee J. O'D.
Published: August 2002

Developments in telepathology robotic systems have evolved the concept of a ‘virtual microscope’ handling ‘digital slides’. Slide digitization is a method of archiving salient histological features in numerical (digital) form. The value and potential of this have begun to be recognized by several international centres. Automated complete slide digitization has application at all levels of clinical practice and will benefit undergraduate, postgraduate, and continuing education. Unfortunately, as the volume of potential data on a histological slide represents a significant problem in terms of digitization, storage, and subsequent manipulation, the reality of virtual microscopy to date has comprised limited views at inadequate resolution. This paper outlines a system refined in the authors' laboratory, which employs a combination of enhanced hardware, image capture, and processing techniques designed for telepathology. The system is able to scan an entire slide at high magnification and create a library of such slides that may exist on an internet server or be distributed on removable media (such as CD‐ROM or DVD). A digital slide allows image data manipulation at a level not possible with conventional light microscopy. Combinations of multiple users, multiple magnifications, annotations, and addition of ancillary textual and visual data are now possible. This demonstrates that with increased sophistication, the applications of telepathology technology need not be confined to second opinion, but can be extended on a wider front. Copyright © 2001 John Wiley & Sons, Ltd.
Two‐ and three‐dimensional ultrasound in malformations of the medullary canal: report of four cases
Authors: Bonilla‐Musoles Fernando , Machado Luis E. , Osborne Newton G. , Muñoz Elkin A. , Raga Francisco , Blanes Javier , Bonilla Jr Francisco
Published: August 2002

A comparison between two‐dimensional (2D), and three‐dimensional (3D) ultrasonography was made in four fetuses diagnosed with neural tube defect (NTD) in the first half of pregnancy. 3D ultrasonography (orthogonal and multiplanar systems) proved to be an excellent complement to 2D, particularly when using orthogonal planes. When using the 3D multiplanar surface imaging system, excellent images of the malformations can be rapidly obtained. Copyright © 2001 John Wiley & Sons, Ltd.
Novel mutations in the human CYP21 gene
Authors: Levo Antti , Partanen Jukka
Published: August 2002

The great majority of genetic defects underlying steroid 21‐hydroxylase deficiency appear to result from intergenic recombinations between the homologous CYP21 and CYP21P genes. For a minority, novel sporadic point mutations have been detected. De novo mutations in CYP21 have also been reported, but only a few studies have systematically screened their occurrence. We here describe a population‐based patient sample in order to estimate the rate of single‐family (i.e. sporadic) and de novo germline mutations in the human CYP21 locus. Among 76 Finnish families were observed three single‐family mutations and two de novo mutations in CYP21. The rates obtained, ∼5% and ∼2% for novel and de novo mutations, respectively, indicate that they are not rare and that their occurrence should not be ignored in genetic diagnostics of this disorder. Copyright © 2001 John Wiley & Sons, Ltd.
Animal models of fetal renal disease
Authors: Peters Craig A.
Published: August 2002

Fetal models of urinary tract disease have been used for many years and have provided unique and important insights into the pathophysiology of these conditions. This review will summarize the principal model systems used and the current directions of investigation. These models (including rabbit, opossum, sheep and recently swine) have demonstrated that in utero obstruction of the urinary tract alters renal growth, differentiation and produces stereotypical patterns of tissue response, particularly fibrosis. New molecular understanding of these processes has identified specific mechanisms that may be key elements in the development of renal dysfunction due to obstruction. These factors include the renin–angiotensin system (RAS) and its interaction with TGF‐β in altering growth regulation and tissue fibrosis. These factors offer the prospect of clinical utility as markers of disease progression as well as pharmacologic therapy. Gene knockout systems have opened a new horizon of molecular models of congenital obstructive uropathy with insights into the role of the RAS in particular. It remains to be defined how closely these knockouts represent the human conditions they resemble. Continued application of fetal models of urinary obstruction, integrating large animal and knockout systems offers promise for improved diagnosis and treatment in these challenging conditions. Copyright © 2001 John Wiley & Sons, Ltd.