bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Generation of β‐L‐Rhamnosidic Linkages by the 2‐Ulosyl Donor Approach: Synthesis of a Trisaccharide with a Central β‐L‐Rhamnose Unit
Authors: Lichtenthaler Frieder W. , Metz Thomas
Published: July 2003

Practical procedures for the production of variously blocked 6‐deoxy‐α‐L‐arabino‐2‐ketohexosyl bromides from L‐rhamnose have been developed. These compounds are highly useful as indirect β‐L‐rhamnosyl donors: they undergo β‐specific glycosidations under Koenigs‐Knorr conditions, and the 2‐keto group of the resulting 6‐deoxy‐β‐L‐hexosiduloses is reduced with high β‐L‐rhamno selectivity. The straightforward application of this 2‐ulosyl donor approach for the synthesis of β‐L‐rhamnose‐containing di‐ and trisaccharides is demonstrated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Sterically Hindered Cyclic Diynes − Syntheses and Structures
Authors: Schaefer Carsten , Gleiter Rolf , Rominger Frank
Published: July 2003

The synthesis of three 14‐membered ring systems 8a−8c with the 1,3,8,10‐tetraoxa‐2,9‐disilacyclotetradeca‐5,12‐diyne skeleton is described. In all three ring systems the α‐positions are substituted with gem‐dimethyl and/or gem‐diphenyl groups. Structural investigations on 8a and 8c reveal a chair like conformation of the central ring with parallel alkyne units. For 8b the voluminous phenyl groups cause a twist‐chair and a twist‐boat conformation. Columnar structures were encountered for 8a in the solid state. Reactions with octacarbonyldicobalt yield for 8a mono‐ and biscomplexation (12, 13). For 8b only the mono complexation product 14 was isolated. For 8c the bis(hexacarbonyldicobalt) complex 15 was obtained. X‐ray investigations revealed columnar structures in the solid state for 12, 13, and 15. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
C‐Glycosidations of a 2‐Ketohexosyl Bromide with Electrophilic, Radical, and Nucleophilic Anomeric Carbons
Authors: Lichtenthaler Frieder W. , Lergenmüller Matthias , Schwidetzky Sabine
Published: July 2003

The susceptibility of acylated 2‐ketohexosyl halides to C‐homologation is demonstrated with the easily accessible tri‐O‐benzoyl‐α‐D‐arabino‐hexos‐ulosyl bromide 1 as the model compound. C‐Glycosidation with an electrophilic anomeric carbon requires prior carbonyl protection, to avoid carbonyl addition by the C‐nucleophile, for example, as the cyanohydrin. Silver triflate‐promoted reaction with the silylenol ether of acetophenone then efficiently yields the β‐phenacyl product. With thermal (AIBN) or photochemical induction, 1 smoothly generates an anomeric radical − comparatively electrophilic, due to its capto‐dative substitution − which exclusively traps hydrogen in the presence of tributyltin and electron‐deficient alkenes. With allyltributylstannanes, however, it reacts with high stereoselectivity to afford α‐C‐allyl glycosiduloses. The α‐bromoketone functionality in ulosyl bromide 1 is susceptible to Reformatsky conditions: treatment with zinc‐copper couple readily generates the 1,2‐enolate, a most simple anomeric nucleophile, which effectively adds to aldehydes to give α‐C‐hydroxyalkyl glycosiduloses or α‐C‐disaccharides (with sugar aldehydes) with a high degree of double stereoselection. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Novel Promising Benzoazacrown Ethers as a Result of Ring Transformation of Benzocrown Ethers: Synthesis, Structure, and Complexation with Ca2+
Authors: Gromov Sergey P. , Dmitrieva Svetlana N. , Vedernikov Artem I. , Kuz’mina Lyudmila G. , Churakov Andrey V. , Strelenko Yuri A. , Howard Judith A. K.
Published: July 2003

A series of promising benzoazacrown ethers with the nitrogen atom conjugated with the benzene ring were synthesized using a novel synthetic procedure based on stepwise transformation of the macroheterocycle. The structures and spectral properties of the resulting benzoazacrown ethers and their complexes with Ca2+ were studied by X‐ray diffraction and 1H, 13C, and 15N NMR spectroscopy including the 2D NOESY technique. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A New Versatile Synthesis of Macrotricyclic Tetraazacycloalkane‐Based Ligands from Bis‐aminal Derivatives
Authors: Develay Stéphanie , Tripier Raphaël , Chuburu Françoise , Le Baccon Michel , Handel Henri
Published: July 2003

A new powerful synthesis of symmetrical (two‐step) or dissymmetrical (three‐step) macrotricyclic cyclen‐ or cyclam‐based ligands is reported. In this procedure, the starting materials are bis‐aminals derived from condensation of cyclen or cyclam with glyoxal. The two macrocyclic subunits are linked by two aromatic spacers through nitrogen atoms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Syntheses and Structures of Imidazole Analogues of Lissoclinum Cyclopeptides
Authors: Haberhauer Gebhard , Rominger Frank
Published: July 2003

The syntheses of the cyclic peptides 3−7, which contain imidazole units in their backbones and resemble naturally occurring marine cyclopeptides such as westiellamide and ascidiacyclamide, are described. Structural investigations on the trimer 3 reveal a molecular triangle conformation with all lone pairs of the imidazole nitrogen atoms and the hydrogen atoms of the secondary amides directed to the center of the macrocycle. The structures of the tetramers 4 and 6 display distorted molecular square conformations with the heterocycles (4) and the αCH groups (6) placed at the corners of the rectangle, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of 1‐ and 3‐Nitrobenzo[a]pyrene
Authors: Dyker Gerald , Kadzimirsz Daniel , Thöne Andreas
Published: July 2003

The synthesis of the important carcinogens 1‐nitrobenzo[a]pyrene and 3‐nitrobenzo[a]pyrene was achieved in four steps starting from the parent compound. A hexyl ester functionality was introduced as a removable blocking group, controlling the regioselectivity of the synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of Benzo[a]pyren‐6‐yl‐Substituted Carboxylic Acids
Authors: Dyker Gerald , Kadzimirsz Daniel
Published: July 2003

The title compounds were synthesized from benzo[a]pyrene in three to four steps, depending on the chain length of the carboxylic acid. After iodination, alkanone chains were introduced by special Heck reactions. Transformation into carboxylic acids was achieved by haloform reaction and by Willgerodt−Kindler reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of “Garner” Aldehyde‐Derived Cyclopropylboronic Esters
Authors: Pietruszka Jörg , Witt Andreas , Frey Wolfgang
Published: July 2003

The “Garner” aldehyde has been used as a common intermediate for the preparation of the corresponding alkyne 7 and the alkenylboronic esters 12−16 (24−80%). Diastereoselective cyclopropanation afforded cyclopropylboronic esters 17−20 (60−84%, dr 22:78 to 92:8), the configurations of which were determined by chemical correlation (cyclopropanols 22), X‐ray structural analysis (of 21a), and characteristic NMR spectroscopic data. The protected amino alcohols 23−26 and amino acids 27 have been synthesised from the cyclopropylboronic esters 19 by oxidation, Matteson homologation or Suzuki coupling. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Reactions of a Stable (Phosphanyl)(silyl)carbene with Aliphatic Aldehydes: [2+1] versus [2+2] Addition to a Carbonyl Group
Authors: Illa Ona , Gornitzka Heinz , Branchadell Vicenç , Baceiredo Antoine , Bertrand Guy , Ortuño Rosa M.
Published: July 2003

The reactions between the stable (phosphanyl)(silyl)carbene 1 and different aliphatic aldehydes have been investigated for the first time. Results reveal that two competitive processes take place. The kinetically most favorable one is a concerted [2+1] cycloaddition to carbonyl leading to oxiranes as single diastereomers, with the trans arrangement of the alkyl and phosphoranyl groups, as the major products. Simultaneously, a [2+2]‐like addition provides short‐lived oxaphosphetene intermediates that rapidly evolve to the corresponding olefins with E stereochemistry, which are the thermodynamically most stable compounds. DFT calculations establish the mechanism for both processes and a rationale for the observed diastereoselectivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Self‐Terminating Radical Oxygenations: Probing of the Scope of the Concept by Use of Various Organic O‐Centered Radicals
Authors: Jargstorff Christian , Wille Uta
Published: July 2003

Addition of various organic O‐centered radicals XO• {i.e. (alkoxycarbonyl)oxyl radicals, ROC(O)O•, [(alkoxycarbonyl)acyl]oxyl radicals, ROC(O)C(O)O•, (carbamoyl)oxyl radicals, R2NC(O)O•, alkoxyl radicals, RO•, and nitroxyl radicals, R2NO•} to alkynes initiates an oxidative radical cyclization cascade, which is terminated by release of a C‐ or N‐centered radical X•. This finding clearly highlights the generality of the recently discovered concept of self‐terminating radical oxygenations, through which C≡C triple bonds may be converted into carbonyl groups under very mild reaction conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Novel Chiral Amide Hosts Derived from Mandelic Acid: A Marked Difference in Inclusion Abilities between Host Stereoisomers
Authors: Tanaka Koichi , Hiratsuka Takaichi , Urbanczyk‐Lipkowska Zofia
Published: July 2003

Novel chiral amide host compounds (2−8) have been synthesized from mandelic acid (1). A marked difference between the inclusion properties of analogous isomers such as 5 and 6 was observed. Host compounds 4 and 5 showed a relatively high chiral recognition in the optical resolution of guest compounds by inclusion crystallization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture: Sterically Hindered Cyclic Diynes − Syntheses and Structures (Eur. J. Org. Chem. 16/2003)
Authors: Schaefer Carsten , Gleiter Rolf , Rominger Frank
Published: July 2003

The cover picture shows on the left‐hand side a sterically hindered cyclic diyne and its synthesis. The packing of the molecules in the crystal is depicted in the center. Within the crystal weak intermolecular interactions were found that are illustrated on the right‐hand side. For more details on the synthesis of sterically hindered cyclic diynes and their reactivity towards octacarbonyldicobalt as well as the solid‐state structures of the diynes and their products, see the article by R. Gleiter et al. on p. 3051 ff.
ADV measurements of velocity distributions in a gravel‐bed flume
Authors: Ferro Vito
Published: July 2003

Velocity measurements carried out by an acoustic doppler velocimeter (ADV) in a rectangular laboratory ﬂume having a gravel bed are presented. The velocity proﬁles are measured in six verticals of the channel cross‐section having an increasing distance (from 4 to 38·5 cm) from the ﬂume wall. The experimental runs are carried out for ﬁve different bed arrangements, characterized by different concentrations of coarser elements, and for the two conditions of small‐ and large‐scale roughness. For both hydraulic conditions, the velocity measurements are ﬁrst used to test the applicability of the Dean proﬁle and of the logarithmic proﬁle corrected by a divergence function proposed in this paper. Then, for each value of the depth sediment ratio h/d84, the non‐dimensional friction factor parameter is calculated by integration of the measured velocity distributions in the different verticals of the cross‐section. Finally a semi‐logarithmic ﬂow resistance equation is empirically deduced. Copyright © 2003 John Wiley & Sons, Ltd.
A casting procedure for reproducing coarse‐grained sedimentary surfaces
Authors: Buffin‐Bélanger Thomas , Reid Ian , Rice Stephen , Chandler Jim H. , Lancaster Jill
Published: July 2003

In the ﬁeld, the measurement of near‐bed hydraulics remains problematic. Greater precision is possible in the laboratory, but, in the case of gravels, it is difﬁcult to create a water‐worked channel‐bed that is realistic enough to replicate faithfully the conditions found in nature. In this paper, a technique to reproduce coarse‐grained sedimentary fabrics of large areal extent is described. It involves moulding natural river‐bed surfaces from which facsimiles are cast. Remarkably realistic casts with dimensions of 1 m by 2 m have been produced and their quality assessed using spatial data derived using automated digital photogrammetry. The casts reproduce the prototype surfaces with errors at millimetre scale (0·5 per cent of the microrelief). The technique has facilitated the introduction of sedimentary surfaces that incorporate natural, complex structures of grains up to cobble size into experimental channels where detailed studies of near‐bed hydraulics can be carried out. Copyright © 2003 John Wiley & Sons, Ltd.
Evolution and inheritance of a rock coast: western Galicia, northwestern Spain
Authors: Blanco Chao R. , Costa Casais M. , Martínez Cortizas A. , Pérez Alberti A. , Trenhaile A. S.
Published: July 2003

There is increasing evidence that shore platforms and other elements of rock coasts may be inherited, at least in part, from interglacial stages when sea level was similar to today's. Most of this evidence, which includes ancient beaches and datable terrestrial deposits, has been obtained from areas of resistant, slowly eroding rock, where the platforms often appear to be much too wide to have developed since the sea reached its present level. It is much more difﬁcult to demonstrate that inheritance has occurred in areas of weaker rock, which generally lack any datable material. The coast of western Galicia in northwestern Spain has shore platforms in igneous and metamorphic rocks that were deeply weathered during the Tertiary. These platforms are closely associated with ancient beaches from the last interglacial stage, and associated periglacial and ﬂuvio‐nival deposits that covered and fossilized most of the Eemian platforms and cliffs during the late middle and late Weichselian glacial stage. The sedimentary processes and the thickness and facies of the sediments were determined by the height, aspect and gradient of the coastal mountains, and their distance from the coast. Radiocarbon dating, sedimentary analysis and platform morphology indicate that the shore platforms of Galicia have been inherited from at least the last interglacial stage. They were fossilized in places beneath thick Weichselian deposits and then exhumed during the Holocene transgression. The abundant evidence for inheritance in Galicia has important implications for other coasts in fairly weak rocks where such evidence is generally lacking. Copyright © 2003 John Wiley & Sons, Ltd.
Stem mechanics, functional anatomy and ecology ofAlnus viridisandAlnus glutinosa
Authors: Brüchert F. , Gallenmüller F. , Bogenrieder A. , Speck T.
Published: July 2003

Mechanical properties, the internal stem structure and the wood anatomy of stems ofAlnusglutinosafrom the Black Forest and of two populations ofAlnusviridisfrom the Black Forest and from the Swiss Alps are compared as to their ecological significance. The mechanical bending properties are characterised by the parameters “flexural stiffness” (Estruct·Iax) and “structural modulus of elasticity” (Estruct). The structural modulus of elasticity increases significantly for all three populations during the first years of growth and becomes approximately constant in stems being five years old and older. These ontogenetic variations of the bending mechanical properties are affected by changes of the internal stem structure, i.e. by changes of the amount and distribution of plant tissues with different mechanical properties within the cross section, described by the axial second moment of area (Iax) which weights the position of the tissues by their distance to the neutral plane. The contribution of bending‐stiff wood towards the axial second moment of area increases during the first years of growth whereas the contribution of the more bending flexible bark decreases. With further increasing age, i.e. in five years old and older stems, the distribution of tissues remains approximately constant as do the mechanical properties. Comparing the different species or populations, respectively, the interspecific difference betweenA.glutinosaandA.viridisfrom the same regional origin (Black Forest) are much smaller than the intraspecific differences between the twoA.viridispopulations from the Black Forest and from the Alps. Significant differences between the two species from the Black Forest are only found in the structural modulus of elasticity of 5–7 year old stems. In contrary, in most ontogenetic stages significant differences are found in all tested mechanical and anatomical parameters betweenA.viridisfrom the Black Forest andA.viridisfrom the Alps. The differences may be due to the different environmental conditions in high elevated sites in the Alps compared to lower sites in the Black Forest. However, the observed differences may also originate from a genetic differentiation into two different ecotypes inA. viridis.
Cotyledon morphology: an aid in identification of Ipomoea taxa (Convolvulaceae)
Authors: Ogunwenmo K. O.
Published: July 2003

Morphometric and qualitative characters of matured cotyledons of 18 taxa of Ipomoea were assessed to determine their value for identification at seedling stage. The characters examined include cotyledon colour, texture, indumentum, basal‐apical notch distance, shape and dimensions. A key for the identification of the taxa based on these characters is presented.
The hairs of Plantago reniformisBeck, section EremopsylliumPilg. (Plantaginaceae)
Authors: Andrzejewska‐Golec E.
Published: July 2003

The paper is a continuation of the investigations on the hairs in representatives of family Plantaginaceae. It regards monotypic section Eremopsyllium Pilg. separated by Pilger from sectio Lamprosantha Decne. According to Rahn and Rønsted it is incorrect. In Plantago reniformis headed hairs typical of the family Plantaginaceae are present. They are plesiomorphic hairs with one celled stalk and head divided vertically into two cells. Headless hairs also are similar to hairs in subgenus Plantago sensu Rahn.
Revision of the subgenus Wichuraea (M.Roemer) Baker of BomareaMirbel (Alstroemeriaceae)
Authors: Hofreiter A. , Tillich H.‐J.
Published: July 2003

The subgenus Wichuraea of Bomarea (Alstroemeriaceae) was last revised by Baker (1888) as part of his revision of the genus Bomarea. Since then the number of validly published names has increased from seven to recently 50, indicating an urgent need for further revision. Extensive field studies in Peru (A. Hofreiter) and depth investigation of herbarium material have led to new insights into the subgenus. As a result a number of Bomarea species formerly placed under Wichuraea are relocated to another subgenus, a large number of names are placed into synonymy and one species, Bomarea vargasii Hofreiter sp. nova, and one subspecies, Bomarea andimarcana subsp. andimarcana Hofreiter comb. nov. und B. andimarcana subsp. densifolia Hofreiter comb. nov., are newly described. A key to the 16 species is given. Field studies revealed that even taxonomically valuable characters can be remarkably variable, even within a single population. This has demonstrably resulted in a high degree of taxa instability in the group. The typical habit and its variability, preferred habitats and the geographical distribution of each species is presented.
Welche Bedeutung hat die sexuelle Reproduktion für den Erfolg der Art Calamagrostis epigejos (L.) Roth?
Authors: Grüttner A. , Heinze U.
Published: July 2003

Als Quellen der Variabilität im Potential der sexuellen Reproduktion fanden sich Unterschiede in der Keimungsgeschwindigkeit (entspelzte Karyopsen keimten rascher und synchroner), bei den Keimraten und vor allem bei der Zahl keimfähiger Diasporen pro Rispe. Von den anderen abweichend zeigten kleine isolierte Bestände geringere Keimraten und brachten – wohl bedingt durch Selbstinkompatibilität – kaum keimfähige Diasporen hervor.

Bei gezielter Suche fanden sich Keimlinge auf offenen, zumindest leicht tonhaltigen Rohböden. Das Wachstum der Keimlinge stagnierte und keiner von über 6000 überlebte bis zum nächsten Jahr. Da Bewässerung die Entwicklung auf dem selben Substrat sehr förderte, war offenbar Wassermangel für das geringe Wachstum ausschlaggebend. Die erfolgreiche generative Etablierung ist also auf den Zufall günstiger Witterungsphasen oder Standorte angewiesen.

Auch im Frühjahr waren noch keimfähige Diasporen in aufrechten Rispen nachweisbar, sodass sich der Diasporenfall mehr oder weniger über das gesamte Jahr erstreckt. Im Zusammenspiel mit dem Fehlen von Dormanz ermöglicht das die Nutzung nicht vorhersagbarer günstiger Witterungsphasen.

Bei einem Kulturversuch kamen einzelne Individuen auch mit schwierigen Substraten gut zurecht, auf denen die Mehrzahl kümmerte. Danach ergibt sich die standörtliche Breite der Art C. epigejos als Summe sehr unterschiedlicher Reaktionsnormen der Individuen.

Die angeführten Befunde unterstreichen insgesamt die Bedeutung der sexuellen Reproduktion und der genetischen Diversität für den Erfolg der Art.
Einfluss extensiver Bewirtschaftung auf die Segetalflora sandiger Standorte unter Berücksichtigung phänologischer Aspekte
Authors: Litterski B.
Published: July 2003

Der Einfluss unterschiedlicher extensiver Bewirtschaftungsweisen auf die Segetalflora ertragsschwacher, sandiger Standorte wird verglichen. Es wird deutlich, dass sich längere bearbeitungsfreie Zeiten (z. B. Stoppelbrache) positiv auf die Artenvielfalt auswirken und dass sowohl typische Segetalpflanzen sandiger Standorte (Zielarten) als auch Unkräuter von der Bewirtschaftung beeinflusst werden. Angaben über den Lebenszyklus einiger Segetalpflanzen werden ergänzt bzw. bestätigt.
Parathyroid adenoma autoinfarction: A report of a case
Authors: Govindaraj Satish , Wasserman Jared , Rezaee Rod , Pearl Adam , Bergman Donald A. , Wang Beverly Y. , Urken Mark L.
Published: July 2003

Background.

Parathyroid adenoma autoinfarction, although uncommon, is an entity that has been previously reported in the literature; however, the influence of intraoperative parathyroid hormone (PTH) monitoring on therapeutic management has not been reported.

Methods.

We present a case of parathyroid autoinfarction that is unique in that it applies a new technology to parathyroid surgery: intraoperative PTH monitoring.

Results.

Intraoperative PTH monitoring aided in the successful surgical management of this patient.

Conclusions.

Intraoperative PTH monitoring can serve as a therapeutic adjunct in the surgical management of parathyroid adenoma autoinfarction. © 2003 Wiley Periodicals, Inc. Head Neck 25: 695–699, 2003
Treatment of gustatory sweating (Frey's syndrome) with botulinum toxin A
Authors: Eckardt André , Kuettner Christian
Published: July 2003

Background.

Gustatory sweating is a common complication of parotid surgery. Injection of botulinum toxin A has been reported as a safe and effective treatment option for patients with Frey's syndrome.

Patients and Methods.

A total of 69 patients who had undergone superficial parotidectomy because of adenoma were evaluated with respect to the incidence of Frey's syndrome and treatment interest. Minor's iodine starch test was used to detect the affected skin area. Affected skin areas were documented using a digital camera; skin areas were evaluated morphometrically. A single injection of Botox per 1 cm2 skin field was administered to those patients interested in treatment.

Results.

Of 43 patients (62%) with gustatory sweating, 33 patients requested treatment. The affected skin area varied from 16 cm2 to 81 cm2. The individual Botox dosage ranged from 16 to 80 IU. All relevant clinical symptoms of sweating disappeared within 1 week after a single injection. Treatment was well tolerated with no side effects.

Conclusion.

Botox A injection is a safe and effective treatment with long‐lasting effects for patients with extensive gustatory sweating. © 2003 Wiley Periodicals, Inc. Head Neck 25: 624–628, 2003
Comparison of pharyngoesophageal segment pressure in total laryngectomy patients with and without pharyngeal neurectomy
Authors: Köybaşıoğlu Ahmet , Öz Övgü , Uslu Sabri , İleri Fikret , İnal Erdoğan , Ünal Selahattin
Published: July 2003

Background.

To compare pharyngoesophageal segment (PES) pressure values in total laryngectomy patients with and without pharyngeal neurectomy (PN) in the early postoperative period.

Methods.

Forty‐five previously untreated laryngeal carcinoma patients were enrolled into this prospective randomized study. Twenty of them underwent total laryngectomy with PN, and 25 underwent total laryngectomy without PN. PES pressures were measured on the tenth postoperative day with a four‐channel catheter.

Results.

Average PES pressures in patients with and without pharyngeal neurectomy were 12.82 ± 6.11 mmHg and 17.40 ± .72 mmHg respectively (p < .05). When compared with the critical point of 20 mmHg that is closely related to voice attainment in the group without pharyngeal neurectomy, 10 (40%) patients had pressure levels greater than 20 mmHg and in the other group only 1 (5%) patient had a pressure level greater than 20 mmHg. The difference between the groups with pressure levels greater than 20 mmHg was found to be statistically significant (p < .05).

Conclusions.

Pharyngeal neurectomy results in a statistically significant decrease of PES pressures in total laryngectomy patients. © 2003 Wiley Periodicals, Inc. Head Neck 25: 617–623, 2003
Rhabdomyoma of the head and neck: Clinicopathologic features of two cases
Authors: Favia Gianfranco , Muzio Lorenzo Lo , Serpico Rosario , Maiorano Eugenio
Published: July 2003

Background.

Extracardiac rhabdomyomas are rare benign tumors of the head and neck. They are frequently misdiagnosed and possibly overtreated when confused with other aggressive tumors.

Methods.

This article reports on the clinicopathologic features of two such tumors affecting adult patients and initially seen as slowly‐growing, indolent neoplasms.

Results.

The tumors were of fibrous consistency, mobile, with well‐demarcated borders and evident lines of cleavage. Both patients were treated by conservative surgery and remained disease‐free after prolonged clinical observation. Histologically, both tumors were composed of large eosinophilic cells intermingled with polyhedral clear cells. Both cell types contained abundant glycogen accumulations.

Conclusions.

The differential diagnosis is with granular cell tumor and with sarcomas, the former being easily distinguishable morphologically, and the latter be seen with more rapid growth and adherence to the adjacent tissues. On the basis of the preceding features, rhabdomyomas can be suspected at a preoperative stage and adequately managed with enucleation or simple excision. © 2003 Wiley Periodicals, Inc. Head Neck 25: 700–704, 2003
Cricopharyngeal spasm and Zenker's diverticulum
Authors: Veenker Elizabeth A. , Andersen Peter E. , Cohen James I.
Published: July 2003

Cricopharyngeal spasm and Zenker's diverticulum represent disorders of the pharyngoesophageal junction for which a unifying theory of etiology has yet to be established. There is, however, a large body of evidence that supports an association with gastroesophageal reflux. Cricopharyngeal myotomy is the key to successful management of both disorders. Newer transoral endoscopic techniques of management have a lower overall morbidity than traditional open approaches in appropriately selected patients and are therefore gaining popularity as the preferred method of treatment. © 2003 Wiley Periodicals, Inc. Head Neck 25: 681–694, 2003
Therapy evaluation of laryngeal carcinomas by tyrosine‐pet
Authors: de Boer Jurjan R. , Pruim Jan , Burlage Fred , Krikke Allard , Tiebosch Anton T. M. G. , Albers Frans W. J. , Vaalburg Willem , van der Laan Bernard F. A. M.
Published: July 2003

Introduction.

One of the major problems in head and neck oncology is determination of tumor status after radiotherapy. Physical examination and conventional imaging by CT and MRI do not always accurately differentiate between residual or recurrent tumor and posttreatment inflammation, fibrosis, edema, or scarring. The feasibility of positron emission tomography (PET) with L‐[1‐11C]‐tyrosine (TYR) for therapy evaluation of laryngeal squamous cell carcinomas by identification of residual or recurrent disease after radiotherapy was investigated.

Patients and Methods.

Nineteen patients with laryngeal carcinomas had standard workups with endoscopy and conventional imaging. All subjects underwent a TYR PET scan (PET1) before definitive treatment. For determination of tumor status, a second TYR PET scan (PET2) was performed 3 months after radiotherapy. At the time of scanning, seven patients were clinically suspected of having residual disease, and in these cases, additional CT imaging and biopsies during endoscopy were performed. During the minimal follow‐up period of 29 months, six patients had clinical suspicion of recurrent disease. In these six cases, a third TYR PET (PET3), CT imaging, and biopsy were performed.

Results.

All pretreatment tumors were depicted by TYR PET (PET1). Three months after radiotherapy, sensitivity and specificity of TYR PET (PET2) for discrimination between residual tumor and benign posttreatment tissue changes were both 100%, and for CT, 50% and 67%, respectively. For detection of recurrent tumor during follow‐up, sensitivity and specificity of TYR PET (PET3) were also 100%, and CT, 75% and 50%, respectively.

Conclusions.

Dynamic TYR PET is an accurate imaging modality for therapy evaluation in detection of residual and recurrent disease with higher sensitivity (100%) and specificity (100%) for discrimination of tumor status by TYR PET compared with conventional imaging. © 2003 Wiley Periodicals, Inc. Head Neck 25: 634–644, 2003
P53 mutation correlates with cisplatin sensitivity in head and neck squamous cell carcinoma lines
Authors: Bradford Carol R. , Zhu Shaobo , Ogawa Haruko , Ogawa Tetsuya , Ubell Matthew , Narayan Ajita , Johnson Garfield , Wolf Gregory T. , Fisher Susan G. , Carey Thomas E.
Published: July 2003

Background.

A critical factor for successful organ preservation treatment in head and neck cancer may be selecting tumors that respond to chemotherapy and radiation. Previous results in patients indicated that tumors that overexpressed p53 were more sensitive to chemotherapy than those that did not overexpress p53.

Methods.

To determine the relationship of p53 mutations to sensitivity to cisplatin in vitro, 23 head and neck squamous cell carcinoma (HNSCC) cell lines were analyzed for cisplatin sensitivity, p53 expression, and p53 mutation status.

Results.

Mutations of the p53 gene were identified in 13 of 23 of the cell lines tested. Mutation of the p53 gene was significantly associated with high levels of expression of the p53 protein. The average ID50 (drug dose required to inhibit 50% of cell growth) for cell lines with mutant p53 was 6.8 μM, whereas the average ID50 for cell lines with wild‐type p53 was 13.7 μM.

Conclusions.

These in vitro data support a role for mutation of the p53 tumor suppressor gene as a marker for response to cisplatin in HNSCC. © 2003 Wiley Periodicals, Inc. Head Neck 25: 654–661, 2003
Distant metastases after definitive radiotherapy for squamous cell carcinoma of the head and neck
Authors: Al‐Othman Majid O. F. , Morris Christopher G. , Hinerman Russell W. , Amdur Robert J. , Mendenhall William M.
Published: July 2003

Purpose.

To analyze parameters that influence the risk of distant metastases after definitive radiotherapy.

Methods.

Between 1983 and 1997, 873 patients were treated with definitive radiotherapy and had follow‐up for 2 years or more. Univariate and multivariate analyses were performed to evaluate risk factors that might influence the risk of distant metastases.

Results.

The 5‐year distant metastasis‐free survival rate was 86%. Univariate analyses revealed that the risk of distant metastases was significantly influenced by gender (p = .0092), primary site (p = .0023), T stage (p < .0001), N stage (p < .0001), overall stage (p < .0001), level of nodal metastases in the neck (p < .0001), histologic differentiation (p = .0096), control above the clavicles (p < .0001), and time to locoregional recurrence (p < .0001). Multivariate analysis of freedom from distant metastases revealed that gender (p = .0390), T stage (p < .0001), N stage (p = .0060), nodal level (p < .0001), and locoregional control (p < .0001) significantly influenced this end point. Multivariate analysis revealed that gender (p = .0049), T stage (p < .0001), N stage (p < .0001), and locoregional control (p < .0001) significantly influenced cause‐specific survival.

Conclusions.

The risk of distant metastases after definitive radiotherapy is 14% at 5 years and is significantly influenced by gender, T stage, N stage, nodal level, and locoregional control. © 2003 Wiley Periodicals, Inc. Head Neck 25: 629–633, 2003
Anaplastic transformation of thyroid cancer: Review of clinical, pathologic, and molecular evidence provides new insights into disease biology and future therapy
Authors: Wiseman Sam M. , Loree Thom R. , Rigual Nestor R. , Hicks Wesley L. , Douglas Wade G. , Anderson Garth R. , Stoler Daniel L.
Published: July 2003

Background.

Anaplastic thyroid cancer ranks among the most lethal of all human malignancies. Its rarity and rapidly fatal course have made it a difficult cancer to both study and treat. Unfortunately, there has been little progress in the management and control of this malignancy. Anaplastic transformation, or the intratumoral evolution of anaplastic carcinoma from pre‐existing differentiated thyroid cancer, has become a well‐accepted process, despite a limited understanding of its underlying mechanisms.

Methods.

It is through review of the literature that an understanding of the aggressive disease biology can be developed. The aim of this review is to evaluate the relevant clinical, pathologic, and molecular studies to develop an insight into the mechanisms that underlie the intratumoral molecular evolution of anaplastic thyroid carcinoma.

Results/Conclusion.

It is based on an understanding of this process that effective treatments for this aggressive malignancy are currently being developed. © 2003 Wiley Periodicals, Inc. Head Neck 25: 662–670, 2003
A histological comparison of deep and superficial lobe pleomorphic adenomas of the parotid gland
Authors: Harney Michael S. , Murphy Colette , Hone Stephen , Toner Mary , Timon Conrad V.
Published: July 2003

Background.

Excision of parotid superficial lobe pleomorphic adenomas requires removal of a surrounding cuff of normal parotid tissue. Less aggressive dissection in removing pleomorphic adenomas that occur in the deep lobe of the parotid gland does not seem to compromise prognosis in these patients. We attempted to define histologic characteristics, differentiating superficial and deep lobe tumors, in an attempt to explain this clinical phenomenon.

Method.

Thirty‐one pleomorphic adenomas, 12 deep‐lobe tumors, and 19 superficial lobe tumors were analyzed and compared, looking at tumor size, capsule thickness, penetration of tumor through capsule, and predominant cell types present.

Results.

The superficial lobe tumors had significantly thinner capsules (p = .02). There was increased extracapsular extension of tumor in the superficial lobe group compared with the deep lobe group (79% and 58%, respectively). The tumors were larger in patients with deep lobe lesions (2.6 cm vs 3.6 cm). There was no difference in predominant cell types.

Conclusions.

The anatomic location of deep lobe tumors is a likely explanation for the histologic differences observed in this study. These important differences allow less aggressive dissection in deep lobe tumors without compromising prognosis. © 2003 Wiley Periodicals, Inc. Head Neck 25: 649–653, 2003
Using thallium‐201 SPECT to detect recurrent or residual nasopharyngeal carcinoma after radiotherapy in patients with indeterminate CT findings
Authors: Shiau Yu‐Chien , Liu Feng‐Yuan , Huang Wen‐Sheng , Yen Ruoh‐Fang , Kao Chia‐Hung
Published: July 2003

Background.

The aim of this study is to evaluate the usefulness of thallium‐201 (Tl‐201) single‐photon emission CT (SPECT) to detect recurrent or residual nasopharyngeal carcinomas (NPC) when CT findings are indeterminate.

Methods.

After radiotherapy, 30 NPC patients with indeterminate CT findings were included. CT, Tl‐201, and biopsy were performed at least 4 months after radiotherapy and within 1 week of each other. The final results were based on histopathologic findings and clinical follow‐up after at least 6 months.

Results.

The rates for sensitivity, specificity, and accuracy of Tl‐201 SPECT in detecting recurrent or residual NPC when there were indeterminate CT findings, were 86.7%, 93.3%, and 90.0%, respectively.

Conclusions.

These results suggest that Tl‐201 SPECT is effective in detecting recurrent or residual NPC when CT findings are indeterminate. © 2003 Wiley Periodicals, Inc. Head Neck 25: 645–648, 2003
Hard palate resection, microvascular reconstruction, and prosthetic restoration: A 14‐year retrospective analysis
Authors: Bernhart Brendan J. , Huryn Joseph M. , Disa Joseph , Shah Jatin P. , Zlotolow Ian M.
Published: July 2003

Background.

This retrospective analysis was conducted to evaluate self‐reported patient and clinician assessed functional outcomes of patients who have undergone ablative hard palate oncologic resection and microvascular free‐flap reconstruction with and without maxillofacial prosthetic intervention.

Methods.

All Head and Neck Surgery Service, Plastic and Reconstruction Surgery Service, and Dental Service charts and progress notes entered into the Institutional Health Care Information System of 57 patients who underwent hard palate resection and microvascular reconstruction at Memorial Sloan‐Kettering Cancer Center (MSKCC) between January 1, 1988, and December 31, 2001 were reviewed retrospectively by three maxillofacial prosthodontists (BJB, JMH, IMZ). Prosthetic and nonprosthetic rehabilitation outcomes for each patient were reported as having normal; limited; or poor esthetics and function according to each prosthodontist's clinical evaluations; patients' self‐perceptions; and feedback from friends, family members, and/or spouse. Speech intelligibility was determined in the same manner but reported as normal, hypernasal, and hyponasal.

Results.

Most of the 26 prosthetically rehabilitated patients were reported as having normal esthetics (81%), normal function (77%), normal speech (96%), and were able to return to per oral full diets (81%) without any restrictions.

Conclusions.

Acceptable oral rehabilitation outcomes were reported for most prosthetically rehabilitated free‐flap patients. Normal speech can be anticipated with a high degree of certainty, and a high percentage of prosthetically restored free‐flap patients achieved per oral diets. © 2003 Wiley Periodicals, Inc. Head Neck 25: 671–680, 2003
Methods for the identiﬁcation of chemical respiratory allergens in rodents: comparisons of cytokine proﬁling with induced changes in serum IgE
Authors: Dearman R. J. , Skinner R. A. , Humphreys N. E. , Kimber I.
Published: July 2003

No validated or widely recognized test methods are currently available for the prospective identiﬁcation of chemicals with the potential to cause respiratory allergy. The cellular and molecular mechanisms that result in the induction of chemical sensitization of the respiratory tract are unclear, although there is evidence for the selective development of T helper 2 (Th2)‐type responses and, in some cases, the production of IgE antibody. We have therefore examined the utility of cytokine proﬁling using BALB/c mice, together with the measurement of induced increases in the total serum concentration of IgE in the Brown Norway (BN) rat, as markers for the prospective identiﬁcation of chemical respiratory allergens. Responses provoked by the reference respiratory allergen trimellitic anhydride (TMA) have been compared with those stimulated by the respiratory sensitizing diisocyanates toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI) and by the acid anhydride hexahydrophthalic anhydride (HHPA). Topical exposure of BN rats to TMA, TDI and HHPA each provoked marked immune activation (increases in lymph node cellularity and proliferation). However, only treatment with TMA stimulated vigorous increases in the total serum concentration of IgE. In contrast, exposure to HHPA, TDI or HDI failed to provoke signiﬁcant changes in serum IgE concentration or induced only transient and relatively weak increases in serum IgE levels. In parallel experiments using BALB/c strain mice, however, topical application of all four chemical respiratory allergens provoked a marked Th2‐type cytokine secretion proﬁle in draining lymph node cells. These data suggest that the measurement of induced changes in serum IgE is not sufﬁciently sensitive for the robust identiﬁcation of chemical respiratory allergens. Furthermore, irrespective of the reasons for variations in TMA‐induced IgE production among BN rats, doubts remain regarding the utility of these animals for the characterization of immune responses to chemical allergens. Cytokine proﬁling using the BALB/c strain mouse apparently provides a more robust method for the hazard assessment of chemical respiratory allergens. Copyright © 2003 John Wiley & Sons, Ltd.
Evidence for redox cycling of lawsone (2‐hydroxy‐1,4‐naphthoquinone) in the presence of the hypoxanthine/xanthine oxidase system
Authors: Osman A. M. , van Noort P. C. M.
Published: July 2003

This study reports that lawsone (2‐hydroxy‐1,4‐naphthoquinone) undergoes redox cycling in the presence of the hypoxanthine/xanthine oxidase system. The rate of cytochrome c reduction obtained in the presence of 80 µM lawsone was almost three times the rate of cytochrome c reduction measured in its absence. This increase in the rate of cytochrome c reduction was partially inhibited by superoxide dismutase, suggesting the involvement of O2•− in this process. It is remarkable to note that, even though lawsone is considered to be a non‐redox‐cycling quinone in vitro, this quinone was shown to be more toxic in vivo in rats than menadione, causing haemolytic anemia of an oxidative nature and renal damage. The view that this quinone is a non‐redox‐cycling quinone was based on the inability of one‐electron‐transferring ﬂavoenzymes such as NADPH‐cytochrome c reductase to reduce this naphthoquinone. Our ﬁnding that lawsone, like menadione, undergoes redox cycling in the presence of the hypoxanthine/xanthine oxidase system could explain the observed oxidative damage of tissues inﬂicted by this quinone in rats in vivo. Such an observation therefore reconciles the in vivo toxicity results of this naphthoquinone with those of in vitro experiments. Copyright © 2003 John Wiley & Sons, Ltd.
Tissue histopathology, clinical chemistry and behaviour of adult comt‐gene‐disrupted mice
Authors: Haasio Kristiina , Huotari Marko , Nissinen Erkki , Männistö Pekka T.
Published: July 2003

Catechol‐O‐methyltransferase (COMT) enzyme is a widely distributed enzyme that catalyses O‐methylation of catecholamines and other compounds having a catechol structure. Because there has been some concern about the consequences of a low COMT activity in the development of oestrogen‐dependent cancers and because one of the COMT inhibitors, tolcapone, has caused serious liver injuries in Parkinsonian patients, the histopathology and clinical chemistry of Comt‐gene‐disrupted mice were studied at the age of 12 months. Owing to the high COMT activities in liver and kidney and the role of COMT in the metabolism of catechol oestrogens, special emphasis was given to the histology of the liver, kidney and oestrogen‐dependent organs such as mammary glands and uterus.

The mice of both heterozygous and homozygous genotypes appear to be physically healthy and fertile. Diurnal motility rhythm and behaviour in measuring anxiety and depression were equal in all genotypes. At the age of 12 months, the body weight of homozygous mice was 7–9% lower than that of the other groups. This was reﬂected in histology as a diminished incidence of vacuolation of liver cells (fatty change). Macroscopic pathology and histopathology revealed no abnormal ﬁndings in any COMT genotype. The values of some clinical chemistry parameters, such as alkaline phosphatase, alanine aminotransferase, urea, glucose, calcium and proteins, were at a higher level in homozygous animals compared with the wild‐type mice. However, all the values remained within the normal physiological range, and the differences in enzyme levels between genotypes were not reﬂected as histopathological ﬁndings in the relevant organs. No changes in haematological parameters or plasma catecholamine concentrations were noted but plasma 3,4‐dihydroxyphenylethylene glycol levels were high in COMT null mice.

The results suggest that the full or 50% lack of Comt gene as such is not associated with any toxic consequences. Copyright © 2003 John Wiley & Sons, Ltd.
Apoptosis induced by different doses of caffeine on Chinese hamster ovary cells
Authors: Fernández M. J. , López A. , Santa‐Maria A.
Published: July 2003

Caffeine has been investigated for its potential mutagenic activity to bacteria, fungi and mammalian cells in culture, and at high concentrations it is also an inducer of apoptosis. Caffeine can exert acute cellular toxicity, including inhibition of cell growth and cell death, in Chinese hamster ovary cells.

The aim of this study was to evaluate the cell survival and apoptotic or non‐apoptotic effects of caffeine to different concentrations in Chinese hamster ovary cells (CHO‐K1). These effects were evaluated by measuring cell viability, caspase 8 activity and fragmented DNA. This study suggests that the concentration of caffeine is of critical importance because high doses of caffeine induce apoptosis and low concentrations can act as an antioxidant.

Previously, the cytotoxicity of caffeine was evaluated using a wide range of concentrations by the neutral red test. From this screening, adequate doses were selected to perform the caspase activity and fragmentation DNA studies. The potential antioxidant effect of caffeine was studied using tert‐butyl‐hydroperoxide as a free‐radical generator. The repeatability was checked through three separate tests with the same concentration. Copyright © 2003 John Wiley & Sons, Ltd.