bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Chemical Devices: Generation of Reversible Extension/Contraction Molecular Motion by Ion‐Triggered Single/Double Helix Interconversion
Authors: Barboiu Mihail , Vaughan Gavin , Kyritsakas Nathalie , Lehn Jean‐Marie
Published: February 2003

The polyheterocyclic strands 1‐H and 2‐H adopt a helical shape enforced by the pyridine–pyrimidine helicity codon. The crystal structure of 2‐H shows the formation of stacks of dimers of right‐ and left‐handed individual helices. Treatment of 1‐H and 2‐H with silver triflate results in the generation of double‐helical entities 1‐DH and 2‐DH, containing two strands and two silver ions. NMR studies and determination of the crystal structure of 2‐DH indicate that the duplex is stabilized by coordination of each Ag+ ion to two terminal bipyridine units, one from each strand, and by pronounced π–π stacking interactions between the internal heterocycles of the strands, yielding a very robust double helical structure. Reversible interconversion of the single and double helix may be achieved by addition of a cryptand capable of sequestering Ag+ and releasing it by protonation. Thus, successive addition of acid and base leads to reversible interconversion between the shorter (∼3.6 Å) single helix and the longer (∼10.3 Å) double helix, resulting in the generation of pronounced extension/contraction motion. The system 1,2‐H/1,2‐DH represents a dynamic chemical device undergoing ionic modulation of reversible molecular mechanical motion fueled by acid/base neutralization.
Synthesis and Solid‐State NMR Studies of P‐Vinylbenzylphosphonic Acid
Authors: Frantz Richard , Durand Jean‐Olivier , Carré Francis , Lanneau Gérard F. , Bideau Jean Le , Alonso Bruno , Massiot Dominique
Published: February 2003

P‐Vinylbenzylphosphonic acid (2) was synthesized and crystallized in two phases A and B. The latter phase was easily converted into the former. Both phases were investigated by IR and solid‐state 31P and 1H NMR spectroscopy, and X‐ray crystallography. The use of recently developed NMR methods has enabled us to increase the usually poor resolution of solid‐state 1H spectra. This gave additional insights on the proton environments. In particular, two dimensional 2D 1H‐31P heteronuclear correlation (HETCOR) experiments, incorporating a Lee–Golburg homonuclear decoupling scheme, allowed description of the mixture of phase A and B.
Detection of tumor specific gene expression in bone marrow and peripheral blood from patients with small cell lung carcinoma
Authors: Shingyoji Masato , Takiguchi Yuichi , Watanabe Reiko , Hiroshima Kenzo , Motoori Ken , Kurosu Katsushi , Kasahara Yasunori , Tanabe Nobuhiro , Tatsumi Koichiro , Kuriyama Takayuki
Published: February 2003

BACKGROUND

Small cell lung carcinoma (SCLC) has the propensity to grow rapidly and metastasize extensively. Detection of micro‐dissemination of SCLC may have clinical relevance. For its detection, tumor‐specific gene expressions were examined in peripheral blood and bone marrow aspirate from patients with SCLC.

METHODS

Expression of prepro‐gastrin‐releasing peptide (preproGRP), neuromedin B receptor (NMB‐R) and gastrin‐releasing peptide receptor (GRP‐R) were examined by reverse transcriptase polymerase chain reaction (RT‐PCR) in peripheral blood and bone marrow aspirate from 40 untreated patients with SCLC. Control samples consisted of peripheral blood samples from 5 patients with nonsmall cell lung cancer (NSCLC) and 20 healthy volunteers.

RESULTS

Positive rates of preproGRP, NMB‐R, and GRP‐R in bone marrow aspirate of patients with SCLC were 23% (9/40), 8% (3/40), and 10% (4/40), respectively. Those rates in peripheral blood were 11% (4/38), 5% (2/38), and 29% (11/38), respectively. Although GRP‐R expression was detected in patients with NSCLC and in healthy volunteers, preproGRP and NMB‐R expressions were not detected in patients with NSCLC and in healthy volunteers. All three gene expressions in bone marrow were more frequently observed in patients with bone marrow metastasis, accessed by biopsy, than in patients without. PreproGRP gene expression in bone marrow was also more frequent in patients with bone metastasis, accessed by bone scintigram, than in patients without, and was related to poorer survival.

CONCLUSIONS

Micro‐dissemination of SCLC was detectable by RT‐PCR of preproGRP and NMB‐R, both specific for SCLC. These gene expressions in bone marrow may be related to disease extent and prognosis. Cancer 2003;97:1057–62. © 2003 American Cancer Society.

DOI 10.1002/cncr.11108
Evaluation of responses to chemoembolization in patients with unresectable hepatocellular carcinoma
Authors: Ebied Osama M. , Federle Michael P. , Carr Brian I. , Pealer Karen M. , Li Wei , Amesur Nikhil , Zajko Albert
Published: February 2003

BACKGROUND

The authors used computed tomography (CT) scans to correlate the changes in tumor vascularity, necrosis, and size with response and survival after transcatheter arterial chemoembolization (TACE) in patients with advanced, unresectable, hepatocellular carcinoma (HCC).

METHODS

The authors studied 72 patients with biopsy‐proven, unresectable HCC and focused on 186 individual tumor masses. A baseline, multiphase, helical CT was performed and at least three follow‐up CT scans were performed after treatment by TACE. Tumors were classified as hypervascular or hypovascular and patients were classified as responders or nonresponders based on CT evidence of altered tumor size, tumor necrosis, and the appearance of new tumors. A new scoring system was used to monitor patient response to TACE.

RESULTS

Thirty‐eight patients were responders and 34 were nonresponders. Patient survival was significantly increased (P = 0.009) in patients who were hypervascular responders. Survival also was increased in hypervascular nonresponders compared with hypovascular nonresponders (P = 0.008) and in hypovascular responders compared with hypovascular nonresponders (P = 0.002). Response to chemoembolization was found to be significantly (P = 0.02) and inversely proportional to tumor size, but the number of tumor foci in an individual patient was not predictive.

CONCLUSIONS

TACE appears to result in improved survival among HCC patients with hypervascular tumors who responded to therapy. However, even patients classified by CT as hypervascular nonresponders and hypovascular responders have improved survival. Cancer 2003;97:1042–50. © 2003 American Cancer Society.

DOI 10.1002/cncr.11111
Stereotactic linear accelerater‐based radiosurgery for the treatment of patients with glomus jugulare tumors
Authors: Maarouf Mohammad , Voges Jürgen , Landwehr Peter , Bramer Rainer , Treuer Harald , Kocher Martin , Müller Rolf‐Peter , Sturm Volker
Published: February 2003

BACKGROUND

The optimal treatment for patients with glomus jugulare tumor (GJT) of the skull base remains controversial. Surgical excision is associated with a high incidence of cranial nerve injury, decreased quality of life, and high mortality. Fractionated radiotherapy is used to control the majority of these tumors, but disadvantages are a prolonged therapy interval and exposition of adjacent brain tissue to irradiation. The authors present the results of a study on 12 of 14 consecutively admitted patients who were treated using linear accelerator‐based radiosurgery (LINAC‐RS), an innovative method for the treatment of GJT.

METHODS

From May 1991 to March 2001, 14 patients with GJT were treated with stereotactic LINAC‐RS for continued growth of tumor or of remaining tumor after surgery. Twelve patients (9 women and 3 men; age range, 28–71 years; median age, 59 years) with a median follow‐up of 4 years (range, 0.8–9,0 years), were selected for retrospective analysis. A median single dose of 15 grays (Gy; range, 11–20 Gy) was applied to the surface of the tumor.

RESULTS

After undergoing LINAC‐RS, 8 of 12 patients (67%) reported partial or complete subjective improvement, whereas complaints remained unchanged in 4 patients (33%). Neurologic status improved in 3 patients (25%) and remained unchanged in 8 patients (67%). Magnetic resonance images showed tumor shrinkage in 8 patients (67%) and no further progression in 4 patients (33%).

CONCLUSIONS

LINAC‐RS is an effective and safe therapy for patients with GJT and may be used as an alternative to surgical resection. Compared with fractionated radiotherapy, LINAC‐RS has some advantages. However, to clarify the question of long‐term tumor control, longer observation times are required. Cancer 2003;97:1093–98. © 2003 American Cancer Society.

DOI 10.1002/cncr.11118
Does local recurrence affect the rate of distant metastases and survival in patients with early‐stage breast carcinoma treated with breast‐conserving therapy?
Authors: Vicini Frank A. , Kestin Larry , Huang Raywin , Martinez Alvaro
Published: February 2003

BACKGROUND

The purpose of the current analysis was to evaluate the impact of local recurrence (LR) on the development of distant metastases (DM), overall survival (OS), and cause specific survival (CSS) in patients with early‐stage breast carcinoma who underwent conservative surgery (CS) and received postoperative radiotherapy (RT).

METHODS

Between 1980 and 1995, 1169 patients underwent CS and received RT. All patients were followed for > 1 year and had ≤ 4 lymph nodes involved with disease. The median duration of follow‐up was 7.7 years. A Cox proportional hazards model was performed to evaluate the effect of LR on the development of DM and CSS. A matched‐pair analysis that controlled for multiple prognostic factors also was performed comparing the outcomes of patients with and without LR.

RESULTS

The LR rate was 11% at 12 years. For the entire population, LR led to poorer OS and CSS rates at 12 years compared with local control (LC) (71% vs. 81% [P = 0.001] and 69% vs. 88% [P < 0.001], respectively). In a Cox multiple regression model, LR was a significant predictor of disease specific mortality. The hazard ratio (HR) associated with LR was 2.69 for mortality and 2.67 for DM (P < 0.001 and P < 0.001, respectively). The median time from surgery to the development of DM was 3.8 years for patients without LR compared with 4.7 years for patients with LR. Patients who developed LR also had two peaks in the rate of DM (at 2.5 years and at 6.5 years) compared to only one peak (at 1.5 years) for patients who did not develop LR. The impact of LR on DM still was evident in patients with small tumors (≤ 2.0 cm; P < 0.001), negative lymph nodes (P = 0.004), or both (P < 0.001). Recurrent disease that developed outside of the surgical bed region had no negative effect on survival. In the matched‐pair analysis (controlling for age, tumor size, grade, number of positive lymph nodes, and estrogen receptor status), LR remained the most significant predictor of mortality (HR: mortality, 5.86; DM, 6.43).

CONCLUSIONS

The current results suggest that LR may be responsible for an increase in DM and disease specific mortality in patients who undergo CS and receive RT. This suggestion is reinforced by the distinct difference seen in the time distribution of DM after LR developed and by the fact that recurrent disease that originated outside of the surgical bed did not affect OS. These data reinforce the necessity to insure optimal LC in patients who are treated with breast‐conserving therapy. Cancer 2003;97:910–9. © 2003 American Cancer Society.

DOI 10.1002/cncr.11143
Vascular endothelial growth factor, CD68, and epidermal growth factor receptor expression and survival in patients with Stage II and Stage III colon carcinoma
Authors: Khorana Alok A. , Ryan Charlotte K. , Cox Christopher , Eberly Shirley , Sahasrabudhe Deepak M.
Published: February 2003

BACKGROUND

The elucidation of new therapeutic targets of prognostic significance in colon carcinoma is necessary to improve outcomes. In the current study, the authors examined the expression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in primary colon carcinoma cases and VEGF in tumor‐associated macrophages (TAM)/stroma, and their correlation with survival.

METHODS

The authors identified 131 consecutive American Joint Committee on Cancer Stage II and Stage III colon carcinoma patients seen at the University of Rochester between 1990–1995. Expression of VEGF, EGFR, and CD68 were examined by immunohistochemistry in paraffin‐embedded primary colon tumors and graded as the percentage of cells stained. Data were analyzed using a multivariate Cox proportional hazards model.

RESULTS

VEGF expression in tumor was not found to be significantly associated with survival. However, 42% of the patients expressed VEGF in TAM/stroma. The median survival in this group was 9.7 years versus 4.3 years in the VEGF‐negative (TAM/stroma) group (hazards ratio of 0.57, 95% confidence interval [95% CI], 0.34–0.95; P = 0.03). Although TAM infiltration alone was not found to be significant in multivariate analysis, the presence of both CD68 and VEGF (TAM/stroma) was predictive of improved survival (hazards ratio of 0.48, 95% CI, 0.28–0.83; P = 0.006). High grades of EGFR expression (≥ Grade 2) were found to be associated with a trend toward worsened survival.

CONCLUSIONS

The greater than twofold increase in median survival associated with VEGF‐expressing TAM suggests a hitherto unknown role for this subset of cells in the host response to colon carcinoma and requires further investigation. Overexpression of EGFR may be associated with worsened survival, providing a rationale for trials of anti‐EGFR agents as adjuvant therapy. Cancer 2003;97:960–8. © 2003 American Cancer Society.

DOI 10.1002/cncr.11152
Quantitative biopsy pathology for the prediction of pathologically organ‐confined prostate carcinoma
Authors: Haese Alexander , Chaudhari Manisha , Miller M. Craig , Epstein Jonathan I. , Huland Hartwig , Palisaar Juri , Graefen Markus , Hammerer Peter , Poole Edward C. , O'Dowd Gerard J. , Partin Alan W. , Veltri Robert W.
Published: February 2003

BACKGROUND

Quantitative biopsy pathology with prostate specific antigen significantly improves the prediction of pathologic stage in patients with clinically localized prostate carcinoma (PCa). The authors recently reported a computational model for predicting patient specific likelihood of organ confinement of PCa using biopsy pathology and clinical data. The current study validates the initial models and presents an new, improved tool for clinical decision making.

METHODS

The authors assessed 10 biopsy pathologic parameters and 2 clinical parameters using data from two institutions. Of 1287 patients, 798 men had pathologically organ confined (OC) PCa, 282 men had nonorgan‐confined disease with capsular penetration (NOC‐CP) only, and 207 men showed seminal vesicle or lymph node invasion (NOC‐AD) after undergoing pelvic lymphadenectomy and radical prostatectomy. Patient input data were evaluated by ordinal logistic (OLOGIT) and neural network (NN) models; and the likelihood of developing OC, NOC‐CP, or NOC‐AD disease was calculated for the combined and separate data sets and was compared with the results from original presentation. In addition, a new two‐output model was constructed (OC/NOC‐CP vs. NOC‐AD).

RESULTS

The three‐output OLOGIT and NN models predicted OC disease with 95.0% and 98.6% accuracy, respectively, for the combined data set and with 93.0% and 98.6% accuracy, respectively, on subset analysis. The combined accuracy for predicting OC, NOC‐CP, and NOC‐AD disease in the entire validation set was 66.7% for OLOGIT model and 66.0% for the NN model. The two‐output OLOGIT and NN models correctly predicted 94.9% and 100.0% of all OC/NOC‐CP disease, respectively.

CONCLUSIONS

Both computation models predicted OC PCa with an accuracy of 93.0–98.6% when they were validated with two different data sets. The OLOGIT and NN‐based, two‐output model permitted an appropriate treatment decision for 85.2–90.2% of patients. These data support the use of quantitative pathology and clinical data‐based decision modeling to manage patients with clinically localized PCa. Cancer 2003;97:969–78. © 2003 American Cancer Society.

DOI 10.1002/cncr.11153
Syndromic aspects of testicular carcinoma
Authors: Holzik Martijn F. Lutke , Sijmons Rolf H. , Sleijfer Dirk T. , Sonneveld Dirk J. A. , Hoekstra‐Weebers Josette E. H. M. , van Echten‐Arends Jannie , Hoekstra Harald J.
Published: February 2003

BACKGROUND

In patients with hereditary or constitutional chromosomal anomalies, testicular carcinoma can develop sporadically or on the basis of an underlying hereditary genetic defect. Greater knowledge of these genetic defects would provide more insight into the molecular pathways that lead to testicular carcinoma. To the authors' knowledge, little attention has been paid to date to the comorbid occurrence of testicular carcinoma in patients with hereditary disorders or constitutional chromosomal anomalies.

METHODS

The authors performed a review of the literature.

RESULTS

Twenty‐five different hereditary disorders or constitutional chromosomal anomalies have been reported in patients who developed seminomatous or nonseminomatous testicular carcinoma.

CONCLUSIONS

Although most of these malignancies were too rare to enable the detection of statistically significant correlations between the chromosomal/hereditary disorder and the testicular tumor, it was striking that many of the patients had also other urogenital abnormalities. Susceptibility to urogenital abnormalities seems to disrupt normal urogenital differentiation and suggests a correlation with testicular dysgenesis and, thus, also with testicular carcinoma. Other evidence of causal involvement has been found in the field of tumor cytogenetics. Some of the genes responsible for hereditary disorders have been mapped to regions that are of interest in the development of sporadic testicular carcinoma. Molecular studies on candidate genes will be required to provide definite answers. Completion of the human gene map and the availability of advanced gene arrays and bioinformatics are expected to greatly facilitate further exploration of the role of hereditary genetic defects in testicular carcinoma. Cancer 2003;97:984–92. © 2003 American Cancer Society.

DOI 10.1002/cncr.11155
Hypermethylation in promoter region of E‐cadherin gene is associated with tumor dedifferention and myometrial invasion in endometrial carcinoma
Authors: Saito Tsuyoshi , Nishimura Makoto , Yamasaki Hiroshi , Kudo Ryuichi
Published: February 2003

BACKGROUND

Loss of E‐cadherin expression is associated with aberrant 5′ CpG island methylation in various tumors.

METHODS

The authors analyzed the methylation status and immunohistochemical expression of E‐cadherin in 142 endometrial tissues, consisting of 21 normal endometria, 17 endometrial hyperplasias, and 104 endometrial carcinomas.

RESULTS

All normal endometria and endometrial hyperplasias showed positive staining of E‐cadherin, and methylation of the E‐cadherin gene was not detected in any samples. In endometrial carcinoma, the positive ratio of methylation was higher and was associated with tumor dedifferention and myometrial invasion. In G1 endometrial adenocarcinomas, 66.7% showed positive staining and 33.3% showed heterogeneous staining. Methylation of the E‐cadherin gene was detected in 15.6%. In G2 tumors, 19.0% showed positive staining, 69.0% showed heterogeneous staining and 11.9% showed negative staining. Methylation of the E‐cadherin gene was found in 50.0%. In G3 tumors, 9.1% showed positive staining, 54.5% showed heterogeneous staining and 36.3% showed negative staining. Methylation of the E‐cadherin gene was found in 81.8% of the tumors. Of the samples with no‐myometrial invasion, 23.1% had methylation. In those with invasion in less than half of the myometrium, 28.6% did and in those with invasion of half or more of the myometrium, 55.6% had methylation. Of samples that did not have lymph node metastasis, 33.7% had methylation, whereas of samples that had lymph node metastasis, 60.0% had methylation.

CONCLUSIONS

This is the first report to analyze methylation of the E‐cadherin gene promoter of endometrial carcinoma and the evidence suggests that methylation of the E‐cadherin gene occurs in association with the acquisition of invasive capacity. Cancer 2003;97:1002–9. © 2003 American Cancer Society.

DOI 10.1002/cncr.11157
Overexpression of Glut‐1 and increased glucose metabolism in tumors are associated with a poor prognosis in patients with oral squamous cell carcinoma
Authors: Kunkel Martin , Reichert Torsten E. , Benz Peter , Lehr Hans‐Anton , Jeong Jong‐Hyeon , Wieand Samuel , Bartenstein Peter , Wagner Wilfried , Whiteside Theresa L.
Published: February 2003

BACKGROUND

The overexpression of glucose transporters, especially of Glut‐1, is a common characteristic of human malignancies, including head and neck carcinoma. Recently, the assessment of glucose metabolism in the tumor with [18F]‐2‐fluoro‐2 deoxy‐D‐glucose (FDG) and positron emission tomography (FDG‐PET) has been used to identify particularly aggressive tumors. The authors tested the hypothesis that both glucose transport and its metabolism play a key role in the progression of oral squamous cell carcinoma (OSCC).

METHODS

Retrospective analysis of Glut‐1 expression was performed by immunohistology in 118 patients with OSCC, and a Glut‐1 labeling index (LI) was established for each. A separate group of 44 patients with primary OSCC was evaluated prospectively by FDG‐PET prior to surgery. To link the expression of Glut‐1 with glucose metabolism, both FDG‐PET and immunohistology were determined in a subgroup of 31 patients, and the results were correlated with overall survival.

RESULTS

The patients who had OSCC with a low LI for Glut‐1 survived significantly longer compared with patients who had OSCC with a high LI (138 months vs. 60 months; P = 0.0034). It was found that Glut‐1 expression was an independent marker of prognosis in patients with OSCC. In patients who were evaluated by FDG‐PET, the standardized uptake value (SUV) below the median split value of 5.6 was predictive of a longer survival (P < 0.027), whereas an SUV > 5.6 was associated with an increased hazard of death. In combination, a high Glut‐1 level and a high SUV predicted shorter survival (P < 0.005) for patients with OSCC. Patients who achieved a complete response to preoperative radiation tended to have tumors with low glucose metabolism, as defined by both the Glut‐1 LI and the SUV.

CONCLUSIONS

Both glucose transport and glucose metabolism determine the glycolytic tumor phenotype, which is a significant negative biomarker of prognosis and overall survival in patients with OSCC. Cancer 2003;97:1015–24. © 2003 American Cancer Society.

DOI 10.1002/cncr.11159
Validation of a treatment policy for patients with prostate specific antigen failure after three‐dimensional conformal prostate radiation therapy
Authors: Pinover Wayne H. , Horwitz Eric M. , Hanlon Alexandra L. , Uzzo Robert G. , Hanks Gerald E.
Published: February 2003

BACKGROUND

The objective of this report was to present an outcomes validation for the Fox Chase Cancer Center (FCCC) management policy for patients who demonstrate prostate specific antigen (PSA) failure after receiving three‐dimensional conformal radiation therapy (3DCRT).

METHODS

Eligible patients included 248 men with T1–T3N0M0 prostate carcinoma who demonstrated PSA failure (according to the American Society for Therapeutic Radiology and Oncology definition) after completing definitive 3DCRT alone or with androgen deprivation (AD) therapy between May 1989 and November 1997. The primary endpoint evaluated was freedom from distant metastasis (FDM). The secondary endpoints evaluated included cause specific survival (CSS) and overall survival (OS). The variables evaluated in the multivariate analyses (MVA) included initial PSA, Gleason score, T classification, dose, PSA nadir, time to PSA failure, PSA doubling time (PSADT), initial use of AD therapy, and the use of AD therapy upon PSA failure.

RESULTS

The 5‐year FDM, CSS, and OS rates for the entire group were 76%, 92%, and 76%, respectively. It was found that four variables were independent predictors of FDM: Gleason score (P= 0.0039), PSA nadir (P= 0.0001), PSADT (P= 0.0001), and the use of AD on PSA failure (P= 0.0001). One hundred forty‐eight men demonstrated a PSADT < 12 months. AD therapy was started in 59 men, and 89 men refused AD therapy and were observed. The use of AD therapy was associated with a significant improvement in the 5‐year FDM rate (57% vs. 78%;P= 0.0026). In the group of men with PSADT < 12 months, the median time to distant failure was significantly longer in the men who received AD therapy (6 months vs. 25 months;P= 0.02). Of the 100 men with a PSADT ≥ 12 months, 89 men were observed, and 11 men received AD therapy. There was no improvement in the 5‐year FDM rate with the use of AD therapy compared with observation (88% vs. 92%, respectively;P= 0.74).

CONCLUSIONS

The current results validate the use of PSADT as an indicator of patients who may be observed expectantly or treated with AD therapy for PSA failure after 3DCRT. Prospective trials are needed to define further the optimal treatment for these patients. Cancer 2003;97:1127–33. © 2003 American Cancer Society.

DOI 10.1002/cncr.11166
A digital watermark technique using morphological signal processing
Authors: Okamoto Akihiro , Miyazaki Akio
Published: February 2003

Electronic watermarking technology has attracted substantial attention recently as a way to provide protection of copyright and prevention of unauthorized copying of digital content. This is realized by embedding copyright information within the content in a form not perceivable by humans. In this paper, an electronic watermarking method is proposed in which the watermarking information is embedded in binary patterns such as characters and figures by making use of morphological signal processing. This method is applied to alphabet characters to show the robustness of the proposed method to noise and printing. It is found possible to realize electronic watermarking by the proposed method for sentences in Western languages. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 67–75, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10007
Computational methods through genetic algorithms for obtaining Stackelberg solutions to two‐level integer programming problems
Authors: Nishizaki Ichiro , Sakawa Masatoshi , Kan Tetsuya
Published: February 2003

In this paper, by using the genetic algorithms whose effectiveness in optimization problems has been demonstrated recently, a derivation is attempted for Stackelberg solutions to two‐level integer programming problems. It is assumed that each integer variable has upper and lower bounds. As the individuals in the genetic algorithm, 0‐1 bit sequences are used. Each individual is required to satisfy the constraints and the decision of the decision maker at the lower level must be a rational response to the decision maker at the upper level. If these two conditions are not satisfied, a penalty is imposed on the fitness. By computational experiment, the proposed method is compared with that of Moore and Bard based on the branch‐and‐bound approach and the effectiveness of the proposed method is demonstrated. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 59–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10012
Associative memory by neural networks with delays and pruning
Authors: Miyoshi Seiji , Okada Masato
Published: February 2003

In the correlation‐type associative memory model it is known that the storage capacity per synapse increases when synapses are pruned. In that case, however, the storage capacity of the whole network is decreased. In order to solve this difficulty, the authors introduce the synapse with delay, and propose a scheme in which the coupling rate of the synapse is reduced while retaining the number of synapses. As an example of such an approach, this paper discusses a discrete‐time synchronous model with delayed coupling and synaptic pruning. The dynamics of the model is investigated theoretically by statistical neurodynamics, and the storage capacity is analyzed quantitatively. An analysis is performed for two types of synaptic pruning, random and systematic. In either case, it is seen that the storage capacity increases when the number of delay stages is increased while reducing the synaptic coupling rate, provided that the total number of synapses is kept constant. The increasing tendency is more marked in systematic pruning than in random pruning. These results were verified by comparing the results to those of computer simulation. The significance of the theoretical findings and the excessive generation and pruning of the synapses in the brain are also discussed from the viewpoint of the theory of computation. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 48–58, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10037
Synchronous acquisition methods with code‐orthogonalizing filters in DS/CDMA over multipath fading channels
Authors: Tahara Masaaki , Hamamura Masanori , Tachikawa Shin'ichi
Published: February 2003

In this paper, we propose a new method for speeding up synchronous acquisition methods by using code‐orthogonalizing filters in DS/CDMA. In the proposed synchronous acquisition method, the normalized complex LMS algorithm is adopted as an adaptive algorithm with code‐orthogonalizing filters and can be applied to multipath fading transmission paths. To further shorten the synchronous acquisition time, we study the step size, the number of updates of the tap weights of the adaptive algorithm, and multiple‐dwell detection. By simulating these methods on a computer, we evaluated the average synchronous acquisition time as a function of the co‐channel power ratio and the number of users, compared the proposed method to conventional methods, and clearly demonstrated its effectiveness. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 38–47, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10051
Design of 2D separable‐denominator state‐space digital filters using orthogonal projection
Authors: Doi Akimitsu , Fujiwara Hiromichi , Hinamoto Takao
Published: February 2003

In this paper, a design method is proposed for a two‐dimensional separable‐denominator state‐space digital filter based on the projection method. First, the square error function is expressed in terms of the coefficient matrix of the local state‐space model. Next, the given FIR filter is realized by a local state‐space model. An equivalent transform based on the eigenvalue–eigenvector decomposition of the impulse response Grammian is applied to this filter. The obtained model is approximated at lower order by orthogonal projection. The projection parameters are optimized by an iterative algorithm based on the error function, deriving a lower dimensional model with a higher design accuracy. The conventional lower dimensional approximation algorithm based on rounding down of the coefficient matrix is used to find the initial values in the present method. The stability of the filter obtained by the present method is always guaranteed. The effectiveness of the present method is confirmed by numerical examples. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 10–18, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10066
Comparison‐checking diagnosis policies for a two‐unit system
Authors: Mizutani Satoshi , Nakagawa Toshio , Ito Kodo
Published: February 2003

This paper considers a two‐unit system for improving reliability and discusses a model that systematically performs diagnosis to detect faults. The system performs comparison‐checking diagnosis while it is operating as a two‐unit system, and performs self‐checking diagnosis when it operates as a single‐unit system. It is assumed that loss due to performance degradation, for example, differs depending on whether comparison‐checking diagnosis or self‐checking diagnosis is performed. In a model performing comparison‐diagnosis at periodic intervals for each operation, the time from the beginning of system operation to detection of faults in both units is defined as a cycle. The inspection strategy of reliability theory is applied to such a model, and the expected time and total expected cost are derived analytically. The optimal diagnosis interval that minimizes the expected cost per unit time is determined. Then, assuming that the fault distribution follows the exponential distribution, the optimal diagnosis interval and the expected cost are calculated numerically, with various discussions. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 1–9, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10068
A secure digital watermark system for secondary distribution
Authors: Iwamura Keiichi , Sakurai Kouichi , Imai Hideki
Published: February 2003

Conventional digital watermark systems assume that the distributor (server) is a completely reliable organization. If the server is not a reliable organization, in a conventional system it is possible that suspicion may fall on a user who is not illegally distributing. Several methods have been proposed to handle this problem. In these methods, however, the system is essentially composed of two kinds of entities: the agent and the users. There is no discussion of a system composed of three entities—authors, agent, and users—where secondary distribution takes place from the author to an agent and then to the users. This paper proposes a digital watermark system that can prevent illegal conduct in a secondary distribution system composed of three types of entities—authors, agent, and users. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 76–85, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1151
Fat‐Derived Aziridines and Their N‐Substituted Derivatives: Biologically Active Compounds Based on Renewable Raw Materials
Authors: Fürmeier Sandra , Metzger Jürgen O.
Published: February 2003

The first successful preparation of the aziridines methyl (9Z,12S,13R)‐12,13‐epimino‐9‐octadecenoate (10), derived from vernolic acid, and methyl (9R,10S,12R)‐9,10‐epimino‐12‐hydroxyoctadecanoate (12a) and methyl (9S,10R,12R)‐9,10‐epimino‐12‐hydroxyoctadecanoate (12b), both derived from ricinoleic acid, is reported. These are the first examples of enantiomerically pure fat‐derived aziridines. Treatment of the corresponding epoxides with sodium azide and ammonium chloride in ethanol in the presence of water yielded the new azido hydroxy compounds, which could be treated in an improved way with polymer‐bound triphenylphosphane to afford the aziridines in good yields. The intermediate azido hydroxy compounds could easily be reduced and so offer access to a variety of interesting β‐amino alcohols 17−21. The synthesis of various N‐substituted aziridine derivatives 22−29 by treatment of methyl cis‐9,10‐epiminooctadecanoate (3) with phenyl isocyanate and isothiocyanate, acetyl chloride, alkyl and aryl chloroformates and acrylonitrile is described. Finally, the fat‐derived 2,5‐dialkyl‐substituted pyrrole methyl 9‐(5‐pentyl‐1H‐pyrrol‐2‐yl)nonanoate (9) was obtained. The previously reported bis(aziridine) methyl cis‐9,10;cis‐12,13‐diepiminooctadecanoate, derived from linoleic acid, and tris(aziridine) methyl cis‐9,10;cis‐12,13;cis‐15,16‐triepiminooctadecanoate, derived from linolenic acid,1 have been subjected to different biological tests and showed cytotoxic and antimicrobial activity as well as remarkable antitumour‐promoting and good neuroprotective effects. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of Buta‐1,3‐diyne‐Bridged Macrocycles with (Z)‐1,4‐Diethynyl1,4‐dimethoxycyclohexa‐2,5‐diene as the Building Block
Authors: Srinivasan Manivannan , Sankararaman Sethuraman , Hopf Henning , Varghese Babu
Published: February 2003

(Z)‐1,4‐Diethynyl‐1,4‐dimethoxycyclohexa‐2,5‐diene has been used as a building block for the synthesis of two novel macrocycles containing buta‐1,3‐diyne units as bridges. The tetrayne derivative 5c has been structurally characterized by single crystal X‐ray crystallographic data. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Semisynthesis of 7‐Deoxypaclitaxel Derivatives Devoid of an Oxetane D‐Ring, Starting from Taxine B
Authors: Beusker Patrick H. , Veldhuis Harald , Brinkhorst Johan , Hetterscheid Dennis G. H. , Feichter Nicolas , Bugaut Anthony , Scheeren Hans W.
Published: February 2003

Six 7‐deoxypaclitaxel derivatives have been prepared from taxine B; they contribute to understanding of the effect of the oxetane D‐ring in paclitaxel on the cytotoxic activity of paclitaxel. Three of these analogues each contain a double bond instead of a D‐ring at the C‐4 position, while two others each contain a three‐membered ring in place of the oxetane ring. Both the C‐4 double bond and the small D‐ring in these paclitaxel derivatives were intended to act as substitutes for the paclitaxel oxetane D‐ring and were expected to impose on the taxane skeleton and the pendant groups a kind of rigidity and conformation similar to that produced by the oxetane ring in paclitaxel. All the derivatives demonstrated considerably reduced in vitro cytotoxic activity − relative to paclitaxel − against a panel of seven well‐characterized human tumor cell lines. The general picture coming out of the structure‐activity relationships of the paclitaxel derivatives reported here is that the presence of an oxygen atom at a spatial position resembling that of the oxygen atom in the oxetane ring of paclitaxel is important if a paclitaxel derivative is to retain considerable cytotoxic activity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
On the Mechanism of Carbohydroxypalladation of Enynes. Additional Insights on the Cyclization of Enynes with Electrophilic Metal Complexes
Authors: Nevado Cristina , Charruault Lise , Michelet Véronique , Nieto‐Oberhuber Cristina , Muñoz M. Paz , Méndez María , Rager Marie‐Noëlle , Genêt Jean‐Pierre , Echavarren Antonio M.
Published: February 2003

Different mechanisms have been proposed for the cyclization of enynes catalyzed by electrophilic metal halides or complexes. We present evidence to indicate that the previously reported “carbohydroxypalladation” and the “hydroxycyclization catalyzed by PtII” are closely related reactions. Thus, palladium complexes formed in situ from PdCl2 and trisulfonated phosphane TPPTS or cyclic phosphite P(OCH2)3CEt as the ligands catalyze the methoxy‐ or hydroxycyclization of enynes with selectivities similar to those observed with PtII complexes. Deuteration studies indicate that activation of the alkyne by PdII promotes an anti‐addition of the alkene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and SAR Studies of 3‐Substituted 1′‐Benzylspiro[[2]benzoxepine1,4′‐piperidines]
Authors: Maier Christoph A. , Wünsch Bernhard
Published: February 2003

The preparation of the hitherto unknown spiro[[2]benzoxepine‐1,4′‐piperidine] ring system is described. The synthesis consists of a Wittig reaction of 2‐bromobenzaldehyde (4) and (1,3‐dioxolan‐2‐ylmethyl)triphenylphosphonium bromide (5) to yield an α,β‐unsaturated acetal. The double bond of 6 was subsequently hydrogenated. The resulting brominated acetal 7 was treated with n‐butyllithium and then with 1‐benzylpiperidin‐4‐one (9) to yield the hydroxy acetal 10. Acid‐catalyzed cyclization of 10 with p‐toluenesulfonic acid or aqueous HCl resulted in the formation of the 1′‐benzylspiro[[2]benzoxepine‐1,4′‐piperidines] 11 and 12, respectively. The substituents in the 3‐position of the spiro compounds 11 and 12 were further modified by reaction with trimethylsilyl cyanide or (cyanomethylene)triphenylphosphorane in order to introduce residues with one or two carbon atoms, respectively. The synthesized compounds were evaluated for σ1‐ and σ2‐receptor affinity in vitro. The most potent σ1‐ligand was the methoxy derivative 11 (Ki = 2.56 nM), whereas the cyanomethyl derivative 20 turned out to be the most σ1‐selective compound (σ1/σ2 selectivity 768). ((© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Three New 2,3‐Dihydroxy Fatty Acid Glycosphingolipids from the Mediterranean Tunicate Microcosmus sulcatus
Authors: Aiello Anna , Fattorusso Ernesto , Mangoni Alfonso , Menna Marialuisa
Published: February 2003

Three new glycosphingolipids (2a−4a) were isolated as their peracetates (2b−4b) from the marine ascidian Microcosmus sulcatus, and their structures were elucidated by spectroscopic and chemical analysis. Compounds 2a−4a are the first natural glycosphingolipids whose ceramide contains a 2,3‐dihydroxy acid. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Iron‐Mediated Synthesis of Carbazomycin G and Carbazomycin H, the First Carbazole‐1,4‐quinol Alkaloids from Streptoverticillium ehimense
Authors: Knölker Hans‐Joachim , Fröhner Wolfgang , Reddy Kethiri R.
Published: February 2003

The total synthesis of the carbazole‐1,4‐quinol alkaloids carbazomycin G (7) and carbazomycin H (8) was achieved by a highly convergent iron‐mediated construction of the carbazole framework. Electrophilic substitution of the arylamine 15 using the iron complex salts 13 and 14, followed by oxidative iron‐mediated arylamine cyclization, afforded the carbazole derivatives 11 and 12, respectively. These carbazoles were transformed to the corresponding carbazole‐1,4quinones 9 and 10 by oxidation with cerium(IV) ammonium nitrate. Finally, regioselective addition of methyllithium at C−1 provided carbazomycin G (7) and carbazomycin H (8). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
New Bis(chalcones) and Their Transformation into Bis(pyrazoline) and Bis(pyrazole) Derivatives
Authors: Pinto Diana C. G. A. , Silva Artur M. S. , Cavaleiro José A. S. , Elguero José
Published: February 2003

The reaction of bis(chalcones) 1a−d and bis(chalcone) tetrabromo derivatives 3a−d with hydrazine hydrate gave bis(pyrazolines) 4a−d and bis(pyrazoles) 5a−d, respectively. Bis(pyrazoles) 5e,f bearing hydroxyphenyl substituents have been prepared from the reaction of bis(chromones) 6c,d with hydrazine hydrate, because their synthesis from the corresponding benzyloxy‐substituted 5c,d gave very poor yields. The structures of all new compounds have been established by extensive NMR spectroscopic studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Unusual Rearrangements of cis‐4,7‐Disubstituted 4,7‐Dihydro4,7‐dihydroxy[2.2]paracyclophanes on Dehydration: Stereoselective Formation of Planar Chiral Cyclohexadienones
Authors: Vorontsova Natalia , Rozenberg Valeria , Vorontsov Evgenii , Antonov Dmitrii , Starikova Zoya
Published: February 2003

Under acid conditions, cis‐4,7‐disubstituted 4,7‐dihydro‐4,7‐dihydroxy[2.2]paracyclophanes undergo dehydration accompanied by rearrangement, affording cyclohexadienone derivatives as major products and with polysubstituted phenols being formed as minor products. The formation of either an ortho or a para semiquinoid system, as well as the configuration of the newly formed asymmetric center, depended strictly on the nature of the substituent (alkyl, allyl, or phenyl). The structures of 3,4‐dihydro‐3,7‐dimethyl[2.2]paracyclophane‐4‐one (10), 3,7‐diallyl‐3,4‐dihydro[2.2]paracyclophane‐4‐one (12), and 4,7‐dihydro‐7,8‐diphenyl[2.2]paracyclophane‐4‐one (22) were determined by X‐ray structural analysis. [2.2]Paracyclophane‐4,7‐quinone (1) was obtained in optically active form. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Voltammetric Study of Nitro Radical Anion Generated from Some Nitrofuran Compounds of Pharmacological Significance
Authors: Bollo S. , Núñez‐Vergara L. J. , Martinez C. , Chauviere G. , Périé J. , Squella J. A.
Published: February 2003

The electrochemical behavior of 2‐(5‐amino‐ 1,3,4‐oxadiazolyl)‐5‐nitrofuran (NF359) and its comparison with well‐known drugs such as nifurtimox (NFX) and nitrofurazone (NFZ) in protic, mixed and aprotic media by cyclic voltammetry, tast and differential pulse polarography was studied. All the compounds were electrochemically reducible in all media being the reduction of the nitrofuran group the main voltammetric signal. The one‐electron reduction couple due to the nitro radical anion formation was visualized in mixed (for NF359 and NFZ) and aprotic media (for all compounds). By applying a cyclic voltammetric methodology we have calculated the decay constants (k2) of the corresponding nitro radical anions in mixed and aprotic media. In mixed medium data fit well with a disproportionation reaction of the nitro radical anion but in aprotic medium fit better with a dimerization reaction. Also, considering cyclic voltammetric measurements in aprotic media we have estimated the reduction potential of the RNO2/RNO2.− couple in aqueous medium, pH 7 (E17 values) finding very good correlation with E17 values obtained by pulse radiolysis. Furthermore we have calculated the equilibrium constants from the electron transfer from nitro radical anion to oxygen (kO2) finding that nitro radical anion from NF359 is thermodynamically favored to react with oxygen in respect to both NFZ and NFX.
Characterization of the Surface Redox Process of Adsorbed Cercosporin (CER) at Glassy Carbon Electrodes by Anodic Stripping Square‐Wave Voltammetry
Authors: Marchiando Nancy Cristina , Zón María Alicia , Fernández Héctor
Published: February 2003

The adsorptive accumulation of cercosporin (CER) at glassy carbon electrodes is studied by square‐wave voltammetry (SWV). The Freundlich adsorption isotherm resulted in being the best one to describe the specific interaction of CER with glassy carbon electrodes by using a fitting procedure of experimental fractional surface coverage vs. the CER bulk concentration (c*CER). SWV was also used to generate Q vs. c*CER and Ip, n. vs. c*CER calibration plots from pure commercial reagent solutions. Theoretical detection limits of 1.8×10−7 and 9.7×10−8 M were calculated from Q. vs. c*CER and Ip, n vs. c*CER plots, respectively. The lowest concentration value measured experimentally from calibration plots performed at a f =40 Hz for a signal to noise ratio of 2 : 1 was 3.7×10−8 M, being this value two orders of magnitude smaller than that obtained previously by us from the diffusion controlled CER reduction peak. Ip, n./f vs. f plots from SW voltammograms performed at different c*CER as well as different accumulation times showed the so‐called “quasi‐reversible maxima”. A splitting of the voltammetric peak was also observed by increasing the SW amplitude at a given frequency. A value of (−0.260±0.011) V was determined for the formal potential of the adsorbed redox couple from the split voltammetric peak. A full characterization of the surface redox process was obtained by applying the methods of the “quasi‐reversible maximum” and the “split SW peak”. In 1 M HClO4 aqueous solution, the formal rate constant and the anodic transfer coefficient were (3.5±0.5)×102 s−1 and (0.50±0.03), respectively. Besides, the number of electrons exchanged during the redox reaction was calculated as n≈1.