bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation products of bisphenol A by a recombinant Trametes villosa laccase and their estrogenic activity
Authors: Fukuda Tetsuya , Uchida Hiroyuki , Suzuki Motoshi , Miyamoto Hideo , Morinaga Hidetaka , Nawata Hajime , Uwajima Takayuki
Published: October 2004

A Trametes villosa laccase, produced as a recombinant protein in Aspergillus oryzae, was purified to an electrophoretically homogeneous state and employed in studies on the metabolism of bisphenol A. Structural analysis of the bisphenol A reaction products by the enzyme indicated that the dimer, trimer, tetramer, pentamer, and hexamer of bisphenol A with CC and/or CO bonds between phenol moieties, were formed as the result of successive oxidative‐condensation. The reaction mixture also contained oligomers fragments, each with phenol molecules, suggesting the occurrence of cleavage of the formed oligomers to release 4‐isopropenylphenol. A luciferase reporter assay using COS‐7 cells revealed that both the soluble and insoluble fractions of the bisphenol A reaction products had no estrogenic activity even at rather high concentrations. Copyright © 2004 Society of Chemical Industry
Hoxc8 early enhancer of the Indonesian coelacanth, Latimeria menadoensis
Authors: Shashikant Cooduvalli , Bolanowski Stacey A. , Danke Joshua , Amemiya Chris T.
Published: October 2004

Hoxc8 early enhancer controls the initiation and establishment phase of Hoxc8 expression in the mouse. Comparative studies indicate the presence of Hoxc8 early enhancer sequences in different vertebrate clades including mammals, birds and fish. Previous studies have shown differences between teleost and mammalian Hoxc8 early enhancers with respect to sequence and organization of protein binding elements. This raises the question of when the Hoxc8 early enhancer arose and how it has become modified in different vertebrate lineages. Here, we describe Hoxc8 early enhancer from the Indonesian coelacanth, Latimeria menadoensis. Coelacanths are the only extant lobefinned fish whose genome is tractable to genome analysis. The Latimeria Hoxc8 early enhancer sequence more closely resembles that of the mouse than that of Fugu or zebrafish. When assayed for enhancer activity by reporter gene analysis in transgenic mouse embryos, Latimeria Hoxc8 early enhancer directs expression to the posterior neural tube and mesoderm similar to that of the mouse enhancer. These observations support a close relationship between coelacanths and tetrapods and place the origin of a common Hoxc8 early enhancer sequence within the sarcopterygian lineage. The divergence of teleost (actinopterygii) Hoxc8 early enhancer may reflect a case of relaxed selection or other forms of instability induced by genome duplication events. J. Exp. Zool. (Mol. Dev. Evol.) 302B:000000, 2004. © 2004 Wiley‐Liss, Inc.
Regulated expression of VP16CREB in neuroblastoma cells: Analysis of differentiation and apoptosis
Authors: Andreatta Cynthia P. , Nahreini Piruz , Hanson Amy J. , Prasad Kedar N.
Published: October 2004

Highly malignant neuroblastoma tumors generally have defects in differentiation and apoptotic pathways. For a better understanding of these events, we use a murine neuroblastoma cell line (NBP2) that terminally differentiates into mature neurons in response to elevated levels of cAMP. Because one of the main downstream effectors of the cAMP signaling pathway is cAMP‐response element binding (CREB), we reasoned that it might affect the expression of genes associated with differentiation and apoptotic events in NBP2 cells. To investigate this, we established tetracycline‐regulated expression (TetOff) of VP16CREB, which constitutively transactivates promoters containing the CRE sequence motif. Using this system, we found that inducible expression of VP16CREB in NBP2 cells results in 1) morphological differentiation that is characterized by the formation of neurites and growth cones, 2) reversible cell differentiation unlike cAMP‐induced terminal differentiation, 3) cell cycle arrest at G1, 4) no apoptosis in the presence of partial inhibition of proteasome unlike an increase in cAMP levels, and 5) changes in the expression of many genes, including down‐regulation of N‐myc, cyclin B1, Dickkopf‐1, and Mad‐2 and up‐regulation of tyrosine hydroxylase, c‐fos, N10, and ICER genes. Although VP16CREB expression and activation of the cAMP pathway impart many similar effects in NBP2 cells, they also bear some distinct genetic and morphological differences. Our data suggest that increased levels of cAMP function through not only CREB but also other signaling pathways that account for the additional cAMP‐induced effects, including irreversible differentiation and onset of apoptosis during partial inhibition of proteasome in NBP2 cells. © 2004 Wiley‐Liss, Inc.
On‐line separation for the speciation of mercury in natural waters by flow injection‐cold vapour‐atomic absorption spectrometry
Authors: Sanz Jon , Raposo Juan Carlos , Larreta Joana , Martinez‐Arkarazo Irantzu , de Diego Alberto , Madariaga Juan Manuel
Published: October 2004

Inorganic mercury and methylmercury are determined in natural waters by injecting the filtered samples onto a low cost commercial flow injection system in which an anion exchange microcolumn is inserted after the injection loop (FIA‐IE). If hydrochloric acid is used as the carrier solution, the HgCl42– species (inorganic mercury) will be retained by the anion exchanger while the CH3HgCl species (methylmercury) will flow through the resin with negligible retention. Four anion exchangers and seven elution agents were checked, in a batch mode, to search for the best conditions for optimal separation and elution of both species. Dowex M‐41 and L‐cysteine were finally selected. Mercury detection was performed by cold vapour‐electrothermal atomic adsorption spectrometry (HG‐ETAAS). Both systems were coupled to perform the continuous on‐line separation/detection of both inorganic mercury and methylmercury species. Separation and detection conditions were optimized by two chemometric approaches: full factorial design and central composite design. A limit of detection of 0.4 μg L–1 was obtained for both mercury species (RSD < 3.0% for 20 μg L–1 inorganic and methylmercury solutions). The method was applied to mercury speciation in natural waters of the Nerbioi‐Ibaizabal estuary (Bilbao, North of Spain) and recoveries of more than 95% were obtained.
Wrapping of Single‐Walled Carbon Nanotubes with A‐B‐A Block Telomers
Authors: Kitano Hiromi , Tachimoto Kazutaka , Nakaji‐Hirabayashi Tadashi , Shinohara Hiroaki
Published: October 2004

Summary: Single‐walled carbon nanotubes (SWNTs) mechanically dispersed in HEPES buffer were incubated with a dispersion of A‐B‐A block telomers, composed of 2‐methacryloyloxyethyl‐D‐glucopyranoside telomers (A block) and a styrene telomer (B block), which had been prepared by the macroinitiator technique. After the incubation, the polymer‐wrapped SWNT could be stably dispersed in the buffer without any precipitation for several months. The glucose residue above the SWNT was definitely recognized by lectin (Concanavalin A) as proven by the increase in turbidity. Using a similar procedure, a block telomer composed of N‐isopropylacrylamide telomers (A block) and a styrene telomer (B block) could easily be deposited onto the SWNT. A temperature‐responsive aggregation and the subsequent precipitation of the modified SWNT could clearly be observed. The usage of the block‐telomer examined here would be promising for the preparation of stable dispersions of SWNTs with various functions.

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Novel Possibilities by Cationic Ring‐Opening Polymerisation of Cyclodextrin Derivatives: Preparation of a Copolymer Bearing Block‐Like Sequences of Tri‐O‐methylglucosyl Units
Authors: Adden Roland , Bösch Andreas , Mischnick Petra
Published: October 2004

Summary: Equimolar mixtures of O‐permethylated and O‐perdeuteromethylated cyclodextrins were submitted to cationic ring‐opening polymerisation (CROP) with Et3OPF6 or BF3 · Et2O as initiator in dichloromethane. Reaction started after an incubation time and yielded a polymeric product, which was partially degraded again during competing chain transfer reaction. Average block length was determined by ESI‐MS after partial methanolysis and was found to be close to the theoretical value of 14 for β‐cyclodextrin in the early stage of the reaction, but decreased to 2–5 during further chain transfer reactions accompanied by an equilibration of α‐ and β‐configurated glucosidic linkages to a ratio of 64:36. Molecular weight was estimated from end group analysis and GPC to reach about 29 000 as a maximum. From 31P NMR spectra of the initiator it was obvious that PF is partly hydrolysed to PO2F under participation of the glass surface.

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Front Cover: Macromol. Chem. Phys. 15/2004
Authors: Severn John R. , Chadwick John C.
Published: October 2004

Front Cover: High and stable activity in ethylene polymerization has been achieved with a wide range of Ti‐based single‐site catalysts without the use of MAO or borate activators, using spherical supports of type MgCl2/AlRn(OEt)3–n obtained by reaction of AlR3 with adducts of MgCl2 and ethanol. Polyethylene having spherical particle morphology and narrow molecular weight distribution was obtained.

Further details can be found in the Full Paper by J. R. Severn and J. C. Chadwick* on page 1987.
Back Cover: Macromol. Chem. Phys. 15/2004
Authors: Egbe Daniel Ayuk Mbi , Sell Stephan , Ulbricht Christoph , Birckner Eckhard , Grummt Ulrich‐Walter
Published: October 2004

Back Cover: The Cover shows the absorption and emission spectra of alkyl‐ and alkoxy‐substituted dialdehydes, and their respective poly[(phenylene ethynylene)‐alt‐(phenylene vinylene)] hybrid polymers, obtained by the polycondensation of the dialdehydes with alkoxy‐substituted bisphosphonates. Photophysical investigations and quantum chemical calculations reveal remarkable differences between alkyl‐ and alkoxy‐substituted dialdehydes. On the contrary, their polymers exhibit similar photophysical properties, indicating an identical fluorophore system located around the lower energy phenylene‐vinylene segment of the polymers.

Further details can be found in the Full Paper by D. A. M. Egbe,* S. Sell, C. Ulbricht, E. Birckner, and U.‐W. Grummt on page 2105.
The meaning of negative DAT SPECT and F‐Dopa PET scans in patients with clinical Parkinson's disease
Authors: Morrish Paul
Published: October 2004

See 10.1002/mds.20313 for a reply to this letter.
Cigarette smoking and Parkinson's disease: A case–control study in a population characterized by a high prevalence of pesticide exposure
Authors: Galanaud Jean‐Philippe , Elbaz Alexis , Clavel Jacqueline , Vidal Jean‐Sébastien , Corrèze Jean‐René , Alpérovitch Annick , Tzourio Christophe
Published: October 2004

Epidemiological studies have been consistent in showing that cigarette smoking is inversely associated with Parkinson's disease (PD), whereas pesticide use is positively associated with PD. However, the relationship between PD and cigarette smoking remains poorly understood. Our objective was to study the relationship between cigarette smoking and PD in a population characterized by a high prevalence of pesticide exposure. This case–control study was carried out among subjects enrolled in the Mutualité Sociale Agricole, the French health insurance organization for workers connected to the agricultural world. We included 247 cases and 676 controls matched on age, sex, and region of residency. Information on smoking was obtained through in‐person interviews. Pesticide exposure was assessed using a case‐by‐case expert evaluation procedure. We found an inverse relationship between ever cigarette smoking and PD (odds ratio [OR] = 0.6; 95% confidence interval [CI] = 0.4–0.9). The strength of this association increased with the number of pack‐years. This relationship was present even when smoking was considered as long as 40 years before PD onset. An inverse association was also present among subjects professionally exposed to pesticides (OR = 0.5; 95% CI = 0.3–0.8) and was independent of the duration of exposure among men. We confirm the inverse association between cigarette smoking and PD in a population characterized by a high prevalence of professional pesticide exposure. The relationship between PD and cigarette smoking was not significantly modified or confounded by exposure to pesticides. © 2004 Movement Disorder Society
Reply: The meaning of negative DAT and F‐Dopa PET scans in a patient with clinical Parkinson's disease
Authors: Marshall Vicky , Grosset Donald
Published: October 2004

See 10.1002/mds.20304 for the original article to which this letter refers.
A new method to measure caudal motor conduction time using magnetic stimulation
Authors: Han Tai Ryoon , Paik Nam Jong , Lee Seong Jae , Kwon Bum Sun
Published: October 2004

Although central motor conduction time (CMCT) has been used for the diagnosis of lumbosacral spinal stenosis (LSSS), its diagnostic value is limited due to the short length of the involved segment compared to the long length of the total conduction distance. To overcome this, we introduce a new method to measure the caudal motor conduction time (caudal MCT) using magnetic stimulation. Magnetic stimulation was applied to the vertex and the T12 and S1 spinous processes for transcortical, thoracic, and sacral stimulation, respectively, and compound muscle action potentials were recorded simultaneously from the rectus abdominis (RA) and the right and left abductor hallucis (AH) muscles using three channels. CMCT was calculated by the latency difference in the AH response between transcortical and sacral stimulation, and between transcortical and thoracic stimulation for RA. Caudal MCT was calculated by subtracting CMCT for RA from that for AH. Caudal MCT was delayed in patients with LSSS compared to normal persons. We suggest that measuring caudal MCT may be useful for the diagnosis of LSSS, but its diagnostic sensitivity and specificity requires prospective study. Muscle Nerve, 2004
Anal sphincter electromyography: Editing of sampled motor unit action potentials
Authors: Gregory W. Thomas , Clark Amanda L. , Johnson Joshua , Willis Kimberly , Stuyvesant Amy , Lou Jau‐Shin
Published: October 2004

During multi‐motor unit action potential (MUAP) analysis of the tonically contracted external anal sphincter (EAS), a mild interference pattern often obscures the baseline, affecting the algorithm's ability to determine accurate boundaries of detected MUAPs. To assess the equivalence of methods of editing and selecting candidate MUAPs from the EAS, 17 nulliparous women underwent concentric needle electromyography (EMG) of the EAS using multi‐MUAP software. The selected MUAPs either were accepted without question (“automated”), or a subset was deleted due to a noisy baseline (“manual‐deletion”) or manually marked (“manual‐mark”). A second examiner repeated the analysis. Each examiner found that the two editing methods were equivalent and yielded results that differed from those obtained by automated analysis of unedited data. However, there was a moderate difference in MUAP amplitude when the manual‐deletion method was compared between the two examiners. Editing of selected EAS MUAPs during multi‐MUAP analysis is required, and development of common protocols is essential to enable meaningful comparisons between similar studies. Muscle Nerve, 2005
Automated parallel investigations/optimizations of the reversible addition‐fragmentation chain transfer polymerization of methyl methacrylate
Authors: Fijten Martin W. M. , Meier Michael A. R. , Hoogenboom Richard , Schubert Ulrich S.
Published: October 2004

Poly(methyl methacrylate)s were successfully synthesized in a controlled fashion via reversible addition‐fragmentation chain transfer polymerizations utilizing an automated synthesizer. Sixteen polymers were synthesized in a parallel way utilizing the Chemspeed Accelerator™ SLT100 to investigate the reproducibility and the control over the polymerizations. The obtained polymers were characterized by gel permeation chromatography (GPC) and automated MALDI TOFMS measurements, thereby proving the reproducibility and controllability of the investigated automated setup. Furthermore, temperature optimization reactions were performed utilizing an individually heatable reactor block. Moreover, to demonstrate the presence of active polymer chains in the reaction mixture, chain extension polymerizations were performed on the automated synthesizer. The results obtained from these chain extension experiments demonstrate the possibility to design well‐defined A‐b‐B block copolymers with different monomers as building units. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5775–5783, 2004
Preparation of methoxy poly(ethylene glycol)/polyester diblock copolymers and examination of the gel‐to‐sol transition
Authors: Kim Moon Suk , Seo Kwang Su , Khang Gilson , Cho Sun Hang , Lee Hai Bang
Published: October 2004

Diblock copolymers consisting of methoxy poly(ethylene glycol) (MPEG) and poly(ϵ‐caprolactone) (PCL), poly(δ‐valerolactone) (PVL), poly(L‐lactic acid) (PLLA), or poly(lactic‐co‐glycolic acid) (PLGA) as biodegradable polyesters were prepared to examine the phase transition of diblock copolymer solutions. MPEG–PCL and MPEG–PVL diblock copolymers and MPEG–PLLA and MPEG–PLGA diblock copolymers were synthesized by the ring‐opening polymerization of ϵ‐caprolactone or δ‐valerolactone in the presence of HCl · Et2O as a monomer activator at room temperature and by the ring‐opening polymerization of L‐lactide or a mixture of L‐lactide and glycolide in the presence of stannous octoate at 130 °C, respectively. The synthesized diblock copolymers were characterized with 1H NMR, IR, and gel permeation chromatography. The phase transitions for diblock copolymer aqueous solutions of various concentrations were explored according to the temperature variation. The diblock copolymer solutions exhibited the phase transition from gel to sol with increasing temperature. As the polyester block length of the diblock copolymers increased, the gel‐to‐sol transition moved to a lower concentration region. The gel‐to‐sol transition showed a dependence on the length of the polyester block segment. According to X‐ray diffraction and differential scanning calorimetry thermal studies, the gel‐to‐sol transition of the diblock copolymer solutions depended on their degrees of crystallinity because water could easily diffuse into amorphous polymers in comparison with polymers with a crystalline structure. The crystallinity markedly depended on both the distinct character and composition of the block segment. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5784–5793, 2004
Block‐diagonalization problem for the common Hückel‐type Hamiltonian matrix of alternant hydrocarbons and its nonperturbative solution
Authors: Gineityte V.
Published: October 2004

The block‐diagonalization problem originating from the Brillouin theorem and determining the noncanonical molecular orbitals (NCMOs) has been formulated and solved for the common Hamiltonian matrix H of alternant hydrocarbons in the framework of the simple Hückel model. The well‐known way of partitioning of the total basis set of 2pz AOs of carbon atoms of these molecules into two subsets allowed the problem to be solved nonperturbatively in terms of entire subsets of atomic orbitals (AOs), and thereby of respective submatrices (blocks) of the matrix H, without specifying either the internal structures or dimensions of the latter. As a result, the NCMOs of alternant hydrocarbons proved to be characterized by common peculiarities, including uniform total extents of delocalization. A close relationship has been established between the block‐diagonalization problem under study and the commutation equation determining the respective one‐electron density matrix (DM) directly without invoking the canonical molecular orbitals (CMOs). In particular, the off‐diagonal blocks both of the NCMO representation matrix C and of the DM P were shown to follow from the same matrix condition originally suggested by G. G. Hall on the basis of structures of CMOs of alternant hydrocarbons. The relationship between the two fundamental noncanonical problems gave an additional insight into the origin of the observed similarity between constitutions of matrices C and P. It has been concluded on this basis that the common DM of alternant hydrocarbons (the charge‐bond order matrix) is among noncanonical (localized) ways of describing electronic structures whatever the actual method of its derivation. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Perturbative perspectives on the chemical reaction prediction problem
Authors: Ayers Paul W. , Anderson James S. M. , Bartolotti Libero J.
Published: October 2004

When a molecule is in the presence of a chemical reagent, the external potential and the number of electrons in the molecule change. This leads to perturbative perspectives on chemical reactivity, wherein the response of a molecule to various “model perturbations” of the external potential and number of electrons is used to predict its reactivity. The perturbative perspective allows one to treat indices associated with conceptual density functional theory in a unified way. Here we concentrate on the implications of the perturbative perspective in describing regioselectivity and certain global properties of molecules, specifically, their electrophilicity, nucleofugality, and electrofugality. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
The basis set effect on the results of the minimization of the total energy bifunctional E[ρA,ρB]
Authors: Dulak Marcin , Wesolowski Tomasz A.
Published: October 2004

The basis set effect on the results of the minimization of the total energy bifunctional E[ρA, ρB] approximated at the local density approximation level is analyzed for several weak intermolecular complexes. The considered complexes formed by hydrocarbons at the equilibrium geometry were previously studied by means of the same formalism using large decontracted basis sets consisting of Gaussian‐type atomic orbitals limited to s‐, p‐, and d‐functions. In this work, we use our two new computer implementations of the formalism to analyze the basis set effects accompanying changing the basis sets from Gaussian‐type orbitals to Slater‐type orbitals and including f‐functions. We show that the interaction energies, their components, and the energies of the highest occupied molecular orbital converge within a range of 0.07 kcal/mol, 0.08 kcal/mol, and 0.06 eV, respectively. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Layer model approach to background correction in r.f.‐GDOES
Authors: Payling R. , Nelis T. , Aeberhard M. , Michler J. , Seris P.
Published: October 2004

Two methods are presented for dealing with variable background signals in radiofrequency glow discharge optical emission spectroscopy (r.f.‐GDOES). Their aim is to improve elemental analysis at trace levels, in bulk analysis or in compositional depth profiling, without having to measure background signals during the analysis. Each method uses background signals measured away from the analytical emission lines of interest during calibration only. The background signal is first determined during calibration for each material type of interest. During analysis in the first method the estimated background signal is varied according to the material type being analysed. In depth profiles this means identifying the various layers present as different material types, hence the name ‘layer model’. The second method is a more conventional approach, where part of the background signal is estimated as a spectral interference. Results are presented for the bulk analysis of a tool steel and for two depth profiles: TiO2 coating on silicon and TiN‐coated tool steel. The two methods give similar results in the depth profiles, both significantly better than with a constant background. Copyright © 2004 John Wiley & Sons, Ltd.
Monte‐Carlo simulation of spatial distribution of characteristic x‐rays in multi‐film targets: source size of Al Kα x‐rays in W/Al film targets
Authors: Yoshioka Akihiro , Yamaguchi Yoshikazu , Tamura Keiji , Shimizu Ryuichi
Published: October 2004

A Monte‐Carlo simulation approach has been applied to describe the spatial distribution of characteristic x‐rays in W/Al film targets of different combinations of film thicknesses for the optimal design of a small‐sized x‐ray source having a high x‐ray intensity.

The result has led to optimal combinations of W and Al film targets for 100 kV electrons, e.g. W(1 µm)/Al(20 µm), W(3 µm)/Al(15 µm) and W(5 µm)/Al(8 µm). These Al/W targets could be used as x‐ray sources for a medical instrument currently under development. Copyright © 2004 John Wiley & Sons, Ltd.
Prophylactic treatment of patients with esophageal varices: Is it ever indicated?
Authors: Greig James D. , Garden O. James , Carter David C.
Published: October 2004

The prognosis of patients who bleed from esophageal varices is dismal. Prophylactic treatment of the varix or the elevated portal venous pressure offers a possibility of improving the outlook for these patients. However, as only approximately one‐third of patients with varices bleed during their lifetime, correct identification of high‐risk patients is vital before embarking on prophylaxis. At present, neither European or Japanese selection criteria are perfect in this respect. The documented incidence of initial variceal bleeding varies between 27% and 48%, and most bleeding episodes occur within the first year after varices are diagnosed. Data from six randomized controlled trials comparing prophylactic β‐blockers with placebo demonstrated a decreased incidence of bleeding in propranolol‐treated patients, which in large measure may depend on patient compliance and did not significantly affect survival in all but one study. Early randomized studies of prophylactic sclerotherapy have shown significant reductions in both the incidence of bleeding and mortality, but this promise has not been sustained by subsequent trials, and indeed sclerotherapy was detrimental in two studies. The impressive results in highly selected patients treated in Japan by prophylactic surgery are unlikely to be repeated in a Western setting, involving patient populations that consist predominantly of alcoholic cirrhotics. At present prophylaxis with β‐blockade seems to offer the best therapeutic option, but the future may lie in the development of new interventional techniques such as tranjugular intrahepatic portosystemic stent shunting (TIPS) or variceal banding, and ultimately with hepatic transplantation.
Long‐term management of variceal bleeding: The place of varix injection and ligation
Authors: Terblanche John , Stiegmann Greg V. , Krige Jake E. J. , Bornman Philippus C.
Published: October 2004

Injection sclerotherapy remains the most widely used long‐term management for patients after an esophageal variceal bleed. Sclerotherapy treatments should be repeated weekly until the varices are eradicated. Follow‐up endoscopy every 6 to 12 months is required for life. Whenever varices recur, further weekly injection treatments are administered until re‐eradication is achieved. Failure of sclerotherapy must be diagnosed early and an alternative salvage procedure performed. We currently recommend the distal splenorenal shunt. Although the complications of sclerotherapy are not great, they are cumulative with time. Unlike most surgical procedures for portal hypertension, the technique of performing sclerotherapy is not standardized, making the comparison of controlled trials difficult. The current status of controlled trials comparing sclerotherapy with other treatments is evaluated. We conclude that repeated injection sclerotherapy is at present the initial treatment of choice for patients after an esophageal variceal bleed. The technique of the new procedure of esophageal variceal ligation is described. As with sclerotherapy, weekly treatment sessions are recommended until the esophageal varices are eradicated, followed by long‐term endoscopic surveillance and repeat ligation treatment when varices recur. The four controlled trials that have compared variceal ligation with sclerotherapy favor ligation. Ligation eradicated esophageal varices with fewer treatment sessions and a lower complication rate. One trial demonstrated improved survival. Complications due to the overtube are being increasingly reported but were not a problem in the controlled trials. Although esophageal variceal ligation or ligation plus sclerotherapy may ultimately prove to be superior to sclerotherapy alone, more data are required before a final conclusion can be reached.
Narrow‐diameter portacaval shunts for management of variceal bleeding
Authors: Collins John Craig , Rypins Eric B. , Sarfeh I. James
Published: October 2004

Over the past decade, we have developed and refined a method for partial portosystemic shunting for the control of bleeding esophageal varices in alcoholic cirrhotic patients. The narrow‐diameter interposition portacaval H‐graft using 8 mm polytetraffuoroethylene has been performed in 32 patients at our institution with low operativ mortality (16.3%) and nearly complete cessation of variceal bleeding (96.7%) over a mean follow‐up period of 43 months. In comparison with total shunts, diminished rates of postshunt encephalopathy (13% versus 40%) have been observed. Prograde portal blood flow has been preserved in 90% of 30 patients studied by perioperative portography. Shunt patency with continued prograde flow has been demonstrated at up to 9 years of follow‐up. Investigators at three other centers have studied partial shunting using substantially similar techniques, with similar findings. Based on these results, we conclude that narrow‐diameter shunts provide effective, long‐lasting treatment for variceal hemorrhage due to portal hypertension in the alcoholic.
Sugiura procedure for management of variceal bleeding in Japan
Authors: Idezuki Yasuo , Kokudo Norihiro , Sanjo Kensho , Bandai Yasutsugu
Published: October 2004

During the last three decades the Sugiura procedure and other nonshunting operations have been widely performed as the operations of choice for bleeding esophageal varices in Japan. The Sugiura procedure (University of Tokyo method), a transthoracoabdominal esophageal transection, consists in paraesophageal devascularization, esophageal transection and reanastomosis, splenectomy, and pyloroplasty. The results have been satisfactory with low operative mortality and low rebleeding rate. The prognosis of the patients after this operation depended on the liver function at the time of operation but not on whether operation was done as an emergency, elective, or prophylactic measure. Although the Sugiura procedure has recently been performed in more selected cases with an advance in endoscopic injection sclerotherapy, this procedure remains the ultimate direct operation for portal hypertension in Japan.
Adult pancreatic tissue fate after pancreatic fragment autotransplantation into the spleen of the pancreatectomized dog
Authors: Madureira Mário L. C.
Published: October 2004

As far as we know, after adult enzyme‐digested pancreatic fragment autotransplantation, the fate of the inoculated pancreatic tissue has never been reported and the hypothetic engrafted islet mass growth by mitotic division or by a true islet neogenesis from ductular precursor cells has never been demonstrated. In dogs with total or near‐total (90%) pancreatectomy that preserves the duodenum and the common bile duct, morphologic study of the pancreatic tissue inoculated into the spleen has demonstrated an exuberant ductular‐acinar‐islet regenerative process, with progressive cystic degeneration of the newly formed ductular‐acinar structures occurring simultaneously with the selective survival and growing predominance of extraductal tissue scattered as distinct islets, clusters of islet cells, or single islet cells. In addition to the B, A2, and D cell types of the normal adult dog islet, we have also seen a peculiar ultrastructural pleomorphism of the insular B cells, frequently combined with their ductular or glandular arrangement in maturing islets. Rare or never before reported islet cell types in the adult dog's islets (G cells, mixed endocrine cells of the A2‐D, D‐B, and A2‐B types, and mixed acinar‐islet cells of the D‐acinar type) were also putatively identified. Using light microscopy we have identified many mitotic figures on ductular and centroacinar cells in ductules and ductular‐acinar structures. Moreover, we have ultrastructurally characterized a pluriendocrine nesidioblastic process identified in the most common islet cell types (B, A2, D) and in G cells and mixed acinar islet cells of the B‐ac, A2‐ac, D‐ac, F‐ac, and G‐ac types as well as “intermediary” or “transitional” cells of incipient ductular‐acinar, ductular‐islet, and ductular‐acinar‐islet differentiation. The characteristics of the extraductal islet tissue and the exuberant nesidioblastic process have demonstrated neogenesis of islets and islet cells from precursor ductular cells at several points after the autotransplant, and we suggest that this mechanism may be of fundamental importance for the engrafted islet mass growth—keeping in mind the age of the pancreatic tissue donors and the life‐span of the juvenile diabetic recipient receiving the transplant. This evolution has taken place simultaneously with the progressive rarefaction of the regenerated ductular‐acinar structures definitively deprived of an intestinal drainage route by virtue of their heterotopic location.
Lymph node metastasis and recurrence in patients with a carcinoma of the thoracic esophagus who underwent three‐field dissection
Authors: Fujita Hiromasa , Kakegawa Teruo , Yamana Hideaki , Shima Ichiro , Tanaka Hissaki , Ikeda Sumihiro , Nogami Shyuichi , Toh Yuhi
Published: October 2004

The indication, efficacy, and extent of extended lymphadenectomy for a carcinoma in the thoracic esophagus remain controversial and under clinical investigation. Here we report the frequency and mode of lymph node metastasis at operation and of lymph node recurrence after operation in 70 patients who underwent three‐field dissection and 75.7% of whom suffered from metastasis or recurrence in the lymph nodes (metastasis in 71.4% and recurrence in 21.4%). metastasis or recurrence in the cervical and cervicothoracic nodes were found in 18.6% and 41.4%, respectively. The frequency of cervical and cervicothoracic lymph node metastasis or recurrence was, respectively, 40.0% and 90.0% for a carcinoma in the upper thoracic esophagus, 21.6% and 37.8% for a carcinoma in the middle thoracic esophagus, and 4.3% and 26.1% for a carcinoma in the lower thoracic esophagus. Lymph node metastasis at operation was most frequently found in the right recurrent nerve nodes, right paracardiac nodes, periesophageal nodes, and lesser curvature nodes, whereas lymph node recurrence after operation was found in the left upper recurrent nerve nodes and the right supraclavicular, celiac, and abdominal paraaortic nodes. Metastasis or recurrence was rarely found in the internal jugular, pretracheal, greater curvature, common hepatic, or splenic nodes. This finding suggests the need for recurrent nerve node dissection for cases and for three‐field dissection for a carcinoma in the upper or middle thoracic esophagus.
Evaluation of two training programs for laparoscopic cholecystectomy: Incidence of major complications
Authors: Yamashita Yuichi , Kurohiji Toshihiko , Kakegawa Teruo
Published: October 2004

To determine the need for a training program for laparoscopic cholecystectomy, we evaluated two programs by surveying perioperative complications. The two programs were completed by eight surgeons in each. Program A consisted of 10 supervised operations and program B of only 2. A total of 1054 operations were performed, and 12 major complications required conversion to open surgery owing to transection of the bile duct in 5 cases, laceration of the common bile duct in 1 case, delayed perforation of the common hepatic duct in 1 case, bile leakage in 2 cases, duodenal injury in 1 case, and bleeding from the cystic artery in 2 cases. The incidence of a major complication was significantly higher in group B than in group A, and six of the nine major complications in group B occurred during the initial seven independent operations. Overall, the most common major complication was an injury during the operation to the common bile duct or to the hepatic duct. Four of the five transections of the bile duct required Roux‐en‐Y hepaticojejunotomy, and the other required end‐to‐end anastomosis with T‐tube drainage; one laceration required simple suture closure; and the one delayed perforation required T‐tube drainage. The mean duration of hospitalization for 7 patients with an injury to the bile duct was 74.4 days (range 16–151 days). We recommend that a training program for laparoscopic cholecystectomy should include at least 10 operations to prevent a major complication during the initial 10 operations.
Preoperative staging of gastric cancer as precondition for multimodal treatment
Authors: Sendler A. , Dittler H. J. , Feussner H. , Nekarda H. , Bollschweiler E. , Fink U. , Helmberger H. , Höfler H. , Siewert J. R.
Published: October 2004

Preoperative staging of gastric cancer plays a crucial role in every multimodal treatment protocol. At present, staging intends to be far more than evaluation of the depth of tumor infiltration into the organ wall, that is, T stage, nodular status (N category), and the presence of distant metastases (M stage) according to UICC criteria. In modern surgical oncology it includes more often the evaluation of prognostic factors such as the RAS‐protein, p53 tumor suppressor gene, growth factor receptors, cell adhesion molecules, proteolytic factors, and proliferation‐associated antigens. Furthermore, evaluation of nodular status is possible by sophisticated computer programs. The conventional staging of gastric cancer using endoscopy and sonography, conventional ultrasonography, computed tomography, and magnetic resonance imaging is discussed. Possible improvements of staging in oncologic centers should include surgical laparoscopy, laparoscopic ultrasonography, and meticulous evaluation of an abdominal lavage including immunohistochemical detection of free tumor cells. The most promising tumor biology‐related prognostic factors in gastric cancer are briefly discussed.
Neoadjuvant chemotherapy for gastric cancer: Update
Authors: Fink U. , Stein H. J. , Schuhmacher C. , Wilke H. J.
Published: October 2004

Neoadjuvant chemotherapy has recently received increasing attention in an attempt to increase the rate of complete tumor resections, combat systemic metastases, and prolong survival in patients with gastric cancer. The available data indicate that neoadjuvant chemotherapy is feasible and does not increase postoperative morbidity and mortality. Compared to the results that can today be obtained with primary resection and lymphadenectomy, however, preoperative chemotherapy has so far failed to show a clear increase in the rate of complete tumor removal in patients with resectable gastric cancer. In patients with locally advanced or unresectable gastric cancer, preoperative chemotherapy may cause substantial reduction in locoregional tumor mass and thus increase the resection rate. This finding appears to translate into a survival benefit for those who respond to chemotherapy and have subsequent complete tumor resection. Because of severe shortcomings in the study design of the published reports, definite conclusions cannot be drawn from the available studies. Randomized controlled prospective trials are therefore clearly warranted. Exact pretherapeutic tumor staging, standardized resection and lymphadenectomy techniques, diligent evaluation of the resected specimen, and close follow‐up are essential when designing these trials to identify subgroups of patients who may benefit from neoadjuvant chemotherapy for gastric carcinoma.
Modified treatment of early gastric cancer: Evaluation of endoscopic treatment of early gastric cancers with respect to treatment indication groups
Authors: Hiki Yoshiki , Shimao Hitoshi , Mieno Hiroyoshi , Sakakibara Yuzuru , Kobayashi Nobuyuki , Saigenji Katsunori
Published: October 2004

The results of endoscopic treatment of early gastric cancers were evaluated. The lesions were divided into two groups: the group with an absolute indication (AI) and the other with a relative indication (RI) for endoscopic treatment. Endoscopic mucosal resection (EMR) was performed on 106 lesions in 104 patients. In addition, 108 patients were treated by laser irradiation (LI). The status of the patients were serially assessed during the postoperative period. The residual rate in AI patients who underwent EMR was 30.3%, whereas the rate in RI patients was 80%. The residual rate in 70 AI patients who underwent LI was 0%. Although the recurrence rate was 4.2%, the cumulative curative rate after additional treatments was 100%. The residual rate in RI patients who underwent LI was 17.4%, and the recurence rate was 13.2%. The cumulative curative rate after additional treatments was 97.4%. In AI patients, the initial mode of treatment used was EMR. Patients who exhibited residual cancerous tissue after EMR or those in whom EMR was difficult to perform, either technically or otherwise, underwent LI. EMR was the first choice therapeutic technique because endoscopic specimens obtained could be subjected to histopathologic examination. In RI patients, the conventional operation was the therapeutic technique of first choice. The LI procedure was performed in those who either refused surgery or who could not undergo operative treatment for various reasons.
Problem of proximal third gastric carcinoma
Authors: Siewert J. R. , Böttcher K. , Stein H. J. , Roder J. D. , Busch R.
Published: October 2004

The prevalence of proximal third gastric carcinoma increases rapidly in the Western world. An analysis of prognostic factors indicates that the poor prognosis usually associated with these tumors is due at least in part to late presentation and advanced tumor stages. The current TNM classification usually understages these tumors because it does not take the partly retroperitoneal location of the proximal stomach into account. After correction of the TNM classification a proximal tumor location has no influence on survival. Because these tumors benefit most from radical lymph node dissection, the retroperitoneal lymphatic drainage must be taken into account when performing lymphadenectomy for proximal third gastric cancer. To avoid pancreatic fistulas and the associated morbidity, a pancreas‐preserving splenectomy and lymphadenectomy should be adapted if an extended lymph node resection of the retroperitoneum is performed. Because of the high prevalence of “intestinal type” tumors in the proximal third of the stomach the extent of the luminal resection margins can be limited; that is, a total gastrectomy with transhiatal resection of the distal esophagus usually suffices to achieve complete tumor removal at the oral margin.
Pancreas‐preserving total gastrectomy for proximal gastric cancer
Authors: Maruyama Keiichi , Sasako Mitsuru , Kinoshita Taira , Sano Takeshi , Katai Hitoshi , Okajima Kazuo
Published: October 2004

Lymph node (LN) dissection along the upper border of the pancreas is one of the essential parts of curative surgery for gastric cancer, and the distal portion of the pancreas was frequently resected for complete removal of LNs along the splenic artery. Hoever, pancreatic juice leakage, subphrenic abscess, and postoperative diabetes were common complications in patients treated by pancreatic resection. To avoid these problems a new surgical procedure, the pancreas‐preserving operation, was developed by Maruyama in 1979. We found that lymphatic channels from the stomach did not flow into the pancreas parenchyma, and that the spleen, splenic artery, and fatty connective tissue including nodes could be removed completely without dissection of the pancreas parenchyma and splenic vein. The preserved pancreas receives its arterial blood supply through the transverse pancreatic artery, and its preservation prevents postoperative diabetes. A total of 299 patients were treated by this procedure. The operative mortality rate was 0.3%, the hospital death rate 1.6%, and the surgical complications rate 19.6%. The cumulative 5‐year survival rate for those with stage II was 70.5% and for those with stage III 54.1%. These results were superior to those of the pancreas resection group.
Splenectomy for treatment of gastric cancer: Japanese experience
Authors: Okajima Kunio , Isozaki Hiroshi
Published: October 2004

Surgery for gastric cancer in Japan has frequently been combined with resection of the spleen (splenectomy) or of the pancreatic body and tail and spleen (pancreatosplenectomy, PS). Splenectomy in patients with gastric cancer has been performed with two major purposes in mind: (1) curability of the cancer and (2) immunologic reasons. Direct cancerous invasion to the pancreas requires PS, although examination of these cases revealed that in 34.3% of such macroscopic invasions only fibrous adhesion to pancreas existed. Metastases to lymph nodes at the splenic hilus (no. 10) or along the splenic artery (no. 11) also required splenectomy. The incidences of no. 10 or no. 11 lymph node metastasis were as high as 26.7% and 22.2% respectively, for cancers of whole stomach, and 15.5% and 12.1% for cancers of the upper portion of stomach. Concerning the immunologic aspect of splenectomy for gastric cancer, the reports of fundamental research and clinical studies suggest that the spleen plays sometimes acts as a suppressor and at other times as a helper to the tumor activity, according to the number of tumor cells. From these data, we concluded that the spleen should be preserved in stage I, II, and III patients with curative operation; for stage IV patients the spleen should be resected. The immunologic significance of splenectomy should be clarified precisely in the near future.
Extended gastrectomy: Who benefits?
Authors: Köckerling F. , Reck T. , Gall F. P.
Published: October 2004

In the area of radical surgical treatment of gastric carcinoma, extended or multiorgan resection is—as is systematically extended lymph node dissection—becoming increasingly important. One indication for extended gastrectomy is intramural or transmural infiltration of neighboring organs or the gross presence of metastatic involvement of the lymph nodes associated with the celiac trunk, splenic artery, or splenic hilum. Because the mortality rate associated with extended gastrectomy is hardly any higher than that for nonextended gastrectomy, the indication for the former may be generously applied. The prognostically most unfavorable case is histologic evidence of transmural infiltration of neighboring organs (pT4). Multiorgan resection with improved systematic extension of lymph node dissection is of greatest benefit to patients with inflammatory adhesion of the stomach to neighboring organs or pN2 lymph node metastases. Intramural infiltration of the esophagus can be treated by including the thoracic part of the esophagus in the gastric resection done via an abdominothoracic approach, ensuring an appropriate margin of clearance, with no significant worsening of the prognosis.