bluuebunny/crossref_metadata_2025 huggingface dataset:
Palliative Chemotherapy or Watchful Waiting? A Vignettes Study Among Oncologists
Authors: Koedoot C.G. , de Haes J.C.J.M. , Heisterkamp S.H. , Bakker P.J.M. , de Graeff A. , de Haan R.J.
Published: August 2002

PURPOSE: To determine the preferences of oncologists for palliative chemotherapy or watchful waiting and the factors considered important to that preference.

METHODS: Sixteen vignettes (paper case descriptions), varying on eight patient and treatment characteristics, were designed to assess the oncologists’ preferences. Their strength of preference was rated on a 7-point scale. An orthogonal main effects design provided a subset of all possible combinations of the characteristics, allowing estimations of the relative weights of the presented characteristics. A written questionnaire was sent to a random sample of oncologists (N = 1,235).

RESULTS: The response rate was 67%, and 697 questionnaires were available for analysis. Eighty-one percent of the respondents were male. The mean age was 46 years. We found considerable variation among the oncologists. No major associations between physician characteristics and preferences were found. Of the patient and treatment characteristics affecting treatment preference, age was the strongest predictor, followed by the patient’s wish to be treated and the expected survival gain. Other patient and treatment characteristics had a limited effect on preferences, except for psychologic distress, which had no independent impact.

CONCLUSION: Patients will encounter different decisions depending on their oncologists’ preferences and their own personal background. Therefore, to ensure adequate information for decision-making processes, decision aids are proposed.
Molecular Biology of Anaplastic Lymphoma Kinase–Positive Anaplastic Large-Cell Lymphoma
Authors: Kutok Jeffery L. , Aster Jon C.
Published: August 2002

ABSTRACT: Anaplastic large-cell lymphoma (ALCL) provides an excellent example of how molecular insights into tumor pathogenesis are influencing and improving tumor classification. ALCL was described initially as a subtype of T-cell/null-cell lymphoma characterized by unusual tumor cell morphology and the expression of CD30. However, it was soon recognized that a subset of ALCLs contained chromosomal translocations involving anaplastic lymphoma kinase (ALK), a novel receptor tyrosine kinase gene. These rearrangements create chimeric genes encoding self-associating, constitutively active ALK fusion proteins that activate a number of downstream effectors, including phospholipase C-gamma, phosphoinositol 3'-kinase, RAS, and signal transducer and activator of transcription proteins, all of which seem potentially important in cellular transformation. Not all tumors classified as ALCLs have ALK rearrangements and, conversely, ALK rearrangements occur in lymphomas of widely varying morphology. Hence, only molecular markers can reliably identify ALK+ ALCL. The importance of doing so is reflected by clinical studies suggesting that ALK+ ALCLs have a significantly better prognosis than other aggressive peripheral T-cell or B-cell lymphomas, including ALK− ALCLs. The unique molecular pathogenesis of ALK+ ALCL is likely to lead to novel therapeutic approaches directed at specific inhibition of ALK or downstream effectors.
Paclitaxel Plus Carboplatin Versus Gemcitabine Plus Paclitaxel in Advanced Non–Small-Cell Lung Cancer: A Phase III Randomized Trial
Authors: Kosmidis Paris , Mylonakis Nick , Nicolaides Costas , Kalophonos Charalabos , Samantas Epaminontas , Boukovinas John , Fountzilas George , Skarlos Dimosthenis , Economopoulos Theophanis , Tsavdaridis Dimitrios , Papakostas Pavlos , Bacoyiannis Charalabos , Dimopoulos Meletios
Published: August 2002

PURPOSE: We conducted this randomized study comparing the activity and toxicity of paclitaxel and gemcitabine (PG) and paclitaxel and carboplatin (PC) combinations for the treatment of advanced non–small-cell lung cancer (NSCLC).

PATIENTS AND METHODS: Chemotherapy-naive patients were randomized to paclitaxel 200 mg/m2on day 1 plus either carboplatin at an area under the concentration-time curve of 6 on day 1 (group A) or gemcitabine 1,000 mg/m2on days 1 and 8 (group B) every 3 weeks. A retrospective cost analysis was conducted using Student’s t test to compare independent samples between groups.

RESULTS: A total of 509 patients (group A, 252 patients; group B, 257 patients) were enrolled; all characteristics were well balanced. The median survival time was 10.4 months (95% confidence interval [CI], 8.8 to 12 months) for group A and 9.8 months (95% CI, 8.0 to 11.7 months) for group B (P = .32). Respective 1-year survival rates were 41.7% and 41.4%. The response rate for group A was 28.0% (2% complete response [CR], 26% partial response [PR] [95% CI, 22% to 34%]), and the response rate for group B was 35.0% (5% CR, 30% PR) [95% CI, 29% to 41%]) (P = .12). Toxicity was mild. Grades 3/4 neutropenia, thrombocytopenia, and anemia for groups A and B were seen in 15% and 15%, 2% and 1%, and 5% and 2%, respectively. The mean total cost (outpatient clinic visits plus chemotherapy drug fee) for group A (€ 7,612.64) versus group B (€ 7,484.77) was not statistically significant (P < .66).

CONCLUSION: The PG combination is as equally active and well tolerated as the PC combination in patients with advanced NSCLC.
Dose-Dense Anthracycline-Based Chemotherapy for Node-Positive Breast Cancer
Authors: Ellis Georgiana K. , Livingston Robert B. , Gralow Julie R. , Green Stephanie J. , Thompson Tove
Published: August 2002

PURPOSE: Theoretical considerations and clinical experience suggest that dose-dense chemotherapy may be superior to other approaches using the same drugs. We studied a dose-dense combination of doxorubicin and cyclophosphamide, with or without fluorouracil, as adjuvant therapy.

PATIENTS AND METHODS: Patients with resected breast cancer were treated if they were node-positive and estrogen receptor–negative, positive for overexpression of Her-2-neu, or had four or more involved nodes. Doxorubicin was given weekly to a total dose of 480 mg/m2. Cyclophosphamide 60 mg/m2 was given daily by mouth during the period of doxorubicin treatment. The first 30 patients received fluorouracil at 300 mg/m2/wk intravenously concurrently with doxorubicin administration. In the last 22, it was omitted because of symptomatic hand-foot syndrome in the majority of patients. Filgrastim (granulocyte colony-stimulating factor [G-CSF]) was administered during chemotherapy every day except the day of intravenous administration and continued until 1 week after the completion of the chemotherapy.

RESULTS: Between October 20, 1992, and June 10, 1997, we enrolled 52 patients. The mean delivered dose-intensity for doxorubicin was 18.6 mg/m2/wk. Hospitalization was required in 6% of patients for reversible febrile neutropenia. There were no acute treatment-related deaths, but one patient subsequently died of acute leukemia with a characteristic translocation for anthracycline-related exposure. At 5 years, the event-free survival was 86% for all patients (95% confidence interval, 75% to 95%).

CONCLUSION: Continuous dose-dense chemotherapy with G-CSF support produced encouraging results, which seem to be superior to those expected with “standard” doxorubicin and cyclophosphamide chemotherapy. It deserves a test in the form of a randomized trial where this approach to anthracycline-based treatment is compared with intermittent administration.
Functional Insulin Receptors on Human Epithelial Ovarian Carcinoma Cells: Implications for IGF-II Mitogenic Signaling
Authors: Kalli Kimberly R. , Falowo Oluwole I. , Bale Laurie K. , Zschunke Michael A. , Roche Patrick C. , Conover Cheryl A.
Published: August 2002

The insulin receptor mediates a proliferative response in certain transformed cells, but little is known about its function in ovarian cancer. We used human epithelial ovarian carcinoma cell lines and lifespan-extended normal ovarian surface epithelial (OSE) cells to examine 125I-insulin binding and mitogenic responses to insulin. All cancer cell and OSE cultures specifically bound 125I-insulin. Except for OV202, the carcinoma lines had elevated insulin binding compared with OSE cells. All carcinoma lines except OV202 expressed insulin receptor as detected by flow cytometry and increased 3H-thymidine incorporation or cell number in response to 0.1–10 nm insulin. Interestingly, similar concentrations of IGF-II also induced proliferation of the insulin-responsive cancer cell lines and displaced 125I-insulin binding. Direct binding of 125I-IGF-II to the insulin receptor was visualized by cross-linking and immunoprecipitation. Binding of IGF-II to the insulin receptor and a proliferative effect of insulin suggest the presence of insulin receptor isoform A. Real-time PCR analyses confirm that insulin receptor isoform A expression predominates over isoform B expression in the ovarian carcinoma cell lines. This report suggests that the insulin receptor may play a role in the regulation of ovarian cancer cell growth.
Estrogen Receptor-Related Receptor α Impinges on the Estrogen Axis in Bone: Potential Function in Osteoporosis
Authors: Bonnelye Edith , Kung Vanessa , Laplace Catherine , Galson Deborah L. , Aubin Jane E.
Published: August 2002

The orphan nuclear estrogen receptor-related receptor α (ERRα) is expressed by osteoblastic cells and plays a functional role in osteoprogenitor proliferation and differentiation. To dissect further the role of ERRα in bone, we investigated the effects of estrogen (E2) on ERRα both in vitro and in vivo. Chronic treatment of fetal rat calvaria cells with E2-stimulated bone nodule formation and up-regulated ERRα mRNA expression at early (10 h and d 8) but not later times in culture, suggesting a link between ERRα and E2 during osteoprogenitor proliferation. ERRα mRNA levels were significantly lower in ovariectomized adult rat bones vs. those of sham-operated rats early (1 d and 1 wk) post surgery, but levels returned to control levels thereafter. ERRα is also expressed in osteoclasts (tartrate-resistant acid phosphatase + multinucleated cells) in vivo and in vitro (RAW 264.7 cells) and ovariectomization lowered the OPG/receptor activator of nuclear factor κB ligand expression ratio. Down-regulation of ERRα expression via antisense treatment of rat calvaria cells not only inhibited osteogenesis but also increased adipocyte colony formation and changed the OPG/receptor activator of nuclear factor κB ligand ratio. These data suggest that ERRα is regulated by estrogen in bone in which it may play a functional role at several levels (osteoblasts, adipocytes, and osteoclasts) in E2 deficiency diseases such as osteoporosis.
Hepatocyte Growth Factor/Scatter Factor Facilitates Migration of GN-11 Immortalized LHRH Neurons
Authors: Giacobini P. , Giampietro C. , Fioretto M. , Maggi R. , Cariboni A. , Perroteau I. , Fasolo A.
Published: August 2002

The molecular cues regulating the migratory process of LHRH neurons from the olfactory placode into the brain are not well known, but gradients of chemotropic and chemorepellent factors secreted by the targets are likely to play a key role in guidance mechanisms.

Hepatocyte growth factor/scatter factor (HGF/SF) is a pleiotropic cytokine inducing cell migration. It is involved in a variety of developmental processes through interaction with its receptor c-Met. Here we show that c-Met-antibody labels LHRH migrating neurons in the olfactory mesenchyme of E12 mouse and analyze the potential chemotropic effect of HGF/SF on two immortalized LHRH cell lines, GT1-7 and GN11, isolated from tumors developed in the hypothalamus and in the olfactory bulb, respectively.

By RT-PCR analysis, Western blotting, and immunocytochemistry, we provide evidence for a high level of c-Met expression in GN11, but not in GT1-7, cells. In addition, HGF/SF treatment promotes specific migratory activity of GN11 cells, as demonstrated by collagen gel assay, time-lapse video microscopy, and Boyden’s chamber experiments. Such promotion is inhibited by the neutralizing antibody.

The data reported here represent the first direct evidence of a chemotactic effect of HGF/SF on immortalized LHRH neurons.
Minireview: A Novel Pathway of Prostacyclin Signaling—Hanging Out with Nuclear Receptors
Authors: Lim Hyunjung , Dey Sudhansu K.
Published: August 2002

Prostacylin (PGI2), one of the major prostaglandins, is derived from arachidonic acid by the action of the cyclooxygenase (COX) system coupled to PGI2 synthase (PGIS). The presence of the COX-2/PGIS at the nuclear and endoplasmic reticular membrane suggests differential signaling pathways of PGI2 actions involving both cell surface and nuclear receptors. Although the signaling of PGI2 via its cell surface receptor, prostacyclin receptor (IP), is well documented in vascular biology, its action via nuclear receptors in other physiological responses is gradually being more appreciated. Peroxisomal proliferator-activated receptors (PPARs), PPARα, PPARγ, and PPARδ, though initially cloned as a family of orphan receptors, are now known for their ligand promiscuity. The ligands range from free fatty acids and their derivatives produced by the cyclooxygenase or lipoxygenase pathway to certain hypolipidemic drugs. The predisposition of PPARs to use a wide spectrum of ligands is well explained by their unusually large ligand-binding pocket. The promiscuous ligand usage by PPARs is also reflected by their involvement in various pathophysiological events. Several recent independent reports show that endogenously produced PGI2 indeed activates PPARδ in vivo, indicating that a novel signaling mechanism for this abundant eicosanoid is operative in certain systems. This review attempts to cover recent developments in nuclear actions of PGI2 in diverse biological functions.
Retinoic Acid Receptors and Retinoids Are Up-Regulated in the Developing and Adult Rat Prostate by Neonatal Estrogen Exposure
Authors: Prins Gail S. , Chang William Y. , Wang Yan , van Breemen Richard B.
Published: August 2002

Exposure to estrogens during the neonatal period interrupts rat prostatic development by reducing branching morphogenesis and by blocking epithelial cells from entering a normal differentiation pathway. Upon aging, ventral prostates exhibit extensive hyperplasia, dysplasia, and massive lymphocytic infiltrate, suggesting that neonatal estrogens may predispose the prostate gland to precancerous lesions. Vitamin A (retinol) and their derivatives (retinoic acids) are known key developmental regulators that bind and activate retinoic acid receptors (RARs). To evaluate whether neonatal estrogenization alters the sensitivity of the developing rat prostate to retinoids, RARα, -β, and -γ cellular localization and protein levels were analyzed over the course of development and into adulthood by immunocytochemistry and Western analysis, whereas mRNA levels were measured using RT-PCR. In addition, intraprostatic retinol and retinoic acid levels were quantitated on d 10 and 90 using HPLC-mass spectroscopy. Male rats were given 25 μg estradiol benzoate or oil on d 1, 3, and 5 of life, and prostatic complexes were removed on d 6, 10, 15, 30, and 90. The RARs localized to distinct cell populations: RARβ was expressed within basal epithelial cells, RARα was localized to differentiated luminal epithelial cells and smooth muscle cells, and RARγ was expressed within periductal stromal cells. Over the normal course of development, total protein and mRNA levels for the RARs declined, so that the adult prostate possessed the lowest amounts of RAR. Exposure to estrogens during the neonatal period resulted in an immediate and sustained increase in RARα levels and in the number of cells that expressed RARβ, whereas RARγ levels were unaffected. Western analysis confirmed that total prostatic RAR protein levels were significantly increased, whereas RT-PCR demonstrated that RARα and RARβ mRNA levels were markedly elevated in response to estrogenic exposure. The total prostatic retinol content was tripled by estrogenic exposure on d 10 and 90, indicating that the ability to retain retinoids within the prostate was permanently increased. Intraprostatic levels of 9-cis- and all-trans-retinoic acid levels were reduced on d 10, whereas 13-cis-retinoic acid levels were increased in response to estrogens. In the adult prostates of rats exposed neonatally to estrogen, total retinoic acid levels were doubled due to significant increases in both 9-cis- and 13-cis-retinoic acids compared with those in control prostates. In summary, levels of specific RARs and their activating ligands are increased in the prostate gland after neonatal estrogenic exposure, and this effect is permanent throughout the life of the animal. Thus, we hypothesize that alterations in morphogenesis as well as dysplasia in the adult prostate may be mediated in part through augmentation of transcriptional signals in the retinoid pathway.
Stimulation of Hepatic Signal Transducer and Activator of Transcription 5b by GH Is Not Altered by 3-Methylcholanthrene
Authors: Timsit Yoav E. , Riddick David S.
Published: August 2002

We are investigating the mechanisms by which aromatic hydrocarbons, such as 3-methylcholanthrene (MC), suppress hepatic cytochrome P450 2C11 (CYP2C11) gene expression. CYP2C11 is an enzyme expressed in the liver of male rats and is regulated by a pulsatile pattern of GH secretion. We have previously shown that MC attenuates the stimulatory effect of GH on CYP2C11 expression in hypophysectomized male rats. In follow-up studies we evaluated the effect of MC on GH-stimulated signal transducer and activator of transcription 5b (STAT5b) phosphorylation, nuclear translocation, and DNA-binding activity. GH-stimulated increases in hepatic nuclear STAT5b and phospho-STAT5b levels were not different between groups of hypophysectomized rats receiving MC or vehicle. This observation was corroborated at the DNA-binding level by EMSA. We also measured GH-induced STAT5b activation in the H4IIE rat hepatoma cell line. STAT5b DNA-binding activity detected in GH-treated cells was not affected by MC. Immunocytochemistry experiments revealed no effect of MC on GH-stimulated STAT5b nuclear translocation in H4IIE cells. These in vivo and in vitro data suggest that interference with GH-stimulated STAT5b activation does not constitute a mechanism by which MC attenuates the stimulatory effect of GH on CYP2C11 gene expression.
Calcium Dynamics and Resting Transcriptional Activity Regulates Prolactin Gene Expression
Authors: Villalobos Carlos , Núñez Lucía , Faught William J. , Leaumont David C. , Boockfor Fredric R. , Frawley L. Stephen
Published: August 2002

Research on the regulation of hormone gene expression by calcium signaling is hampered by the difficulty of monitoring both parameters within the same individual, living cells. Here we achieved concurrent, dynamic measurements of both intracellular Ca2+ concentration ([Ca2+]i) and prolactin (PRL) gene promoter activity in single, living pituitary cells. Cells were transfected with the luciferase reporter gene under control of the PRL promoter and subjected to bioluminescence and fluorescence imaging before and after presentation of TSH-releasing hormone (TRH), a prototypic regulator of PRL secretion and gene expression that induces a transient Ca2+ release, followed by sustained Ca2+ influx. We found that cells displaying specific photonic emissions (i.e. mammotropes) showed heterogeneous calcium and transcriptional responses to TRH. Transcriptionally responsive cells always exhibited a TRH-induced [Ca2+]i increase. In addition, transcriptional responses were related to the rate of Ca2+ entry but not Ca2+ release. Finally, cells lacking transcriptional responses (but showing [Ca2+]i rises) exhibited larger levels of resting PRL promoter activity than transcriptionally responsive cells. Thus, our results suggest that the sustained entry of Ca2+ induced by TRH (but not the Ca2+ release) regulates transcriptional responsiveness. Superimposed on this regulation, the previous, resting PRL promoter activity also controls transcriptional responses.
Ghrelin Stimulates GH But Not Food Intake in Arcuate Nucleus Ablated Rats
Authors: Tamura Hideki , Kamegai Jun , Shimizu Takako , Ishii Shinya , Sugihara Hitoshi , Oikawa Shinichi
Published: August 2002

Ghrelin, an endogenous ligand for the GH secretagogue receptor 1a (GHS-R1a), was originally purified from the rat stomach. Ghrelin mRNA and peptide have also been detected in the hypothalamus and pituitary. Ghrelin is a novel acylated peptide that regulates GH release and energy metabolism. GHS-R1a mRNA is expressed in the pituitary gland as well as in several areas of the brain including the hypothalamus. In this study, we examined whether ghrelin could stimulate GH secretion and feeding in chronic GHRH, neuropeptide Y, and agouti-related protein deficient rats that were neonatally treated with monosodium glutamate (MSG), which destroys the neurons in the hypothalamic arcuate nucleus (ARC). Intravenous (iv) administration of rat ghrelin (10 μg/kg body weight) increased plasma GH levels significantly in the normal adult male rats during a GH trough period of pulsatile GH secretion, while iv injection of ghrelin in MSG-treated rats resulted in a markedly attenuated GH response. When rat ghrelin (10 μg/rat) was administered intracerebroventricular (icv), plasma GH levels were increased comparably in normal control and MSG-treated rats. However, the GH release after icv injection of ghrelin was markedly diminished compared with that after iv administration of a small amount of ghrelin in normal control rats (icv: 10 μg/rat, iv: approximately 4.0 μg/rat), indicating that the GH-releasing activity of exogenous ghrelin is route dependent and at least in part via hypothalamic ARC. The icv administration of 1 μg of ghrelin increased significantly 4-h food intake in normal control, whereas the peptide did not increase food intake in MSG-treated rats, indicating that the feeding response to ghrelin requires intact ARC. Taken together, the primary action of ghrelin on appetite control and GH releasing activity is via the ARC even though it might act on another type of GHS-R besides GHS-R1a.
Regulation of Microsomal P450, Redox Partner Proteins, and Steroidogenesis in the Developing Testes of the Neonatal Pig
Authors: Moran F. M. , Ford J. J. , Corbin C. J. , Mapes S. M. , Njar V. C. , Brodie A. M. , Conley A. J.
Published: August 2002

Testicular growth and plasma androgen concentrations increase markedly in the first weeks of neonatal life of pigs. The regulation of steroidogenesis through this period was examined by measuring total microsomal cytochromes P450 (P450), 17α-hydroxylase/17,20-lyase P450 (P450c17) and aromatase P450 (P450arom) enzyme activities, and the redox partner proteins nicotinamide adenine dinucleotide phosphate, reduced form (NADPH)-cytochrome P450 reductase (reductase) and cytochrome b5 in testicular microsomes. Testes were collected from 1–24 d of age, and testicular development was suppressed by a GnRH antagonist in some animals from d 1–14. Both 17/20-lyase and aromatase activities increased from d 1–7 but not thereafter, and 17–20-lyase activity was always at least 200-fold higher than aromatase activity. Reductase decreased in wk 1, then increased to d 24. No changes were seen in cytochrome b5 expression. GnRH antagonist treatment suppressed plasma LH, testosterone and testes growth to d 14. 17,20-Lyase and aromatase activities in testicular microsomes were reduced by 20% and 50%, respectively. Total microsomal P450 concentration was reduced by 50% on d 7, but there was no effect of treatment on reductase or cytochrome b5 expression. These data support the hypothesis that the rise in neonatal testicular androgen secretion is more likely due to gonadotropin-stimulated gonadal growth, rather than specific P450c17 expression. Neither P450c17 nor P450arom can account for the decline in total microsomal P450. Reductase and cytochrome b5 expression appears to be constitutive, but reductase levels saturate both P450c17 and P450arom.
Postnatal Growth and Circulating ACTH and Cortisol Concentratoins during the First Month of Life in Cloned Lambs
Authors: Edwards Lisa , Peura Teija , Hartwich Katrina , Rudiger Skye , McMillen I. Caroline , Walker Simon
Published: August 2002

Recent studes have indicated that there is a decrease in perinatal survival of apparently normal animals produced by somatic-cell nuclear transfer. Here we report that the cortisol and adrenocorticotrophic hormone (ACTH) profiles of cloned lambs in the first 4 weeks of life are significantly different to that of control lambs. The growth of cloned lambs however was not different to controls. These findings demonstrate that endocrine development may be altered in apparently “normal” clones.
Review: Organotin compounds and their therapeutic potential: a report from the Organometallic Chemistry Department of the Free University of Brussels
Authors: Gielen Marcel
Published: August 2002

An overview of the development of antitumour organotin derivatives is presented and discussed for selected classes of compounds, such as tetraorganodicarboxylatodistannoxanes and related diorganotin dicarboxylates, and for triorganotin carboxylates. Among the carboxylate groups used are steroidcarboxylates and other biologically relevant carboxylates. High to very highin vitroactivities have been found, sometimes equalling that of doxorubicin. Solubility in water is an important issue, dominating thein vivotesting of compounds. Polar substituents, like fluorine or polyoxaalkyl moieties, improve the water solubility. Although organotin derivatives constitute a separate class of compounds, the comparison with cisplatin is inevitable. Among the observed toxicities, neurotoxicity, known from platinum cytostatics, and gastrointestinal toxicity, typical for many oncology drugs, have been detected, but to a lower extent. Further research to develop novel useful organotin antitumour compounds needs to be carried out. Copyright © 2002 John Wiley & Sons, Ltd.
Cobalt(II) tri‐tert‐butoxysilanethiolates: in search of models for catalytic metal site of liver alcohol dehydrogenase
Authors: Becker Barbara , Pladzyk Agnieszka , Konitz Antoni , Wojnowski Wieslaw
Published: August 2002

The reaction of dimeric [Co{SSi(OtBu)3}2(NH3)]2 (1) with 2‐picoline at 0 °C leads to the formation of a thiolate complex [Co{SSi(OtBu)3}2(NH3)(2‐Pic)] (3), with two different nitrogen ligands in the cobalt(II) coordination sphere. Dissolution of 1 in acetonitrile gives one cobalt(II) thiolate complex with two ammine ligands bonded to metal: [Co{SSi(OtBu)3}2(NH3)2]·MeCN (4). A second, unique, aqua‐ligated cobalt(II) thiolate — [Co{SSi(OtBu)3}3(H2O)]− +HNEt3 (5) — forms when CoCl2 reacts with an excess of (tBuO)3SiSH in the presence of triethylamine in water. The structures of 3, 4 and 5 were determined by X‐ray structure methods, revealing a distorted tetrahedral arrangement of ligands around cobalt. Under normal conditions, all three complexes are unstable. 3 loses ammonia to give stable [Co{SSi(OtBu)3}2(2‐Pic)] (2). A reverse reaction is also possible. Moreover, 2 is able to capture water, and there is spectral evidence that a complex [Co{SSi(OtBu)3}3(H2O)(2‐Pic)] with a CoNOS2 core, mimicking the cobalt‐substituted liver alcohol dehyrogenase active site, is formed in solution. Copyright © 2002 John Wiley & Sons, Ltd.
Grignard reagents in toluene solutions
Authors: Sassian M. , Panov D. , Tuulmets A.
Published: August 2002

Grignard reagents were prepared from chloroalkanes and chlorobenzene in toluene in the presence of one or 0.5 equivalents of various organic bases (ethers and amines). Reagents with an average monosolvation can be obtained in high yields from primary or secondary alkyl chlorides and chlorobenzene. Diethyl ether is the most effective donor, in that it affords the reagents with a very small content of base. The kinetics of the reactions of n‐butylmagnesium chloride in diethyl ether, and of this Grignard reagent monosolvated with the ether in toluene, with alkylalkoxysilanes were investigated. Reactivity of the partially solvated reagent greatly exceeds that of the conventional Grignard reagent. Yields of addition and reduction reactions of mono‐ and semi‐solvated n‐butylmagnesium chlorides in toluene with a ketone, an aldehyde, and two esters were determined. The partially solvated reagents afford the addition products (tertiary alcohols) in yields better than, or at least comparable to, those obtained with the conventional Grignard reagents. Copyright © 2002 John Wiley & Sons, Ltd.
Communication: A complex with the cyclo‐R2Sb2S2 [R = CH(SiMe3)2] ligand
Authors: Breunig Hans Joachim , Ghesner Ioan , Lork Enno
Published: August 2002

The reaction of the cyclo oligomers R
nSb
nS
n [n = 2, 3; R = CH(SiMe3)2] with W(CO)5thf (thf = tetrahydrofuran) in thf results in trapping of the dimer in cyclo‐[R2Sb2S2][W(CO)5]2 (1). An X‐ray crystal structure analysis revealed that the complex contains a four‐membered antimony–sulfur ring in an almost planar conformation, where the alkyl groups occupy cis positions and the W(CO)5 units are bonded trans to the alkyl groups on the antimony atoms. Copyright © 2002 John Wiley & Sons, Ltd.
Review: Applications of novel sterically demanding aromatics in organometallic synthesis
Authors: Steele Barry R. , Micha‐Screttas Maria , Screttas Constantinos G.
Published: August 2002

Catalytic amounts of the mixed reagents n‐BuLi and LiK(OCH2CH2NMe2)2 in combination with Mg(OCH2CH2OEt)2 promote the multiple and clean addition of ethylene to a series of alkyl aromatics to produce sterically demanding aromatic hydrocarbons and their functional derivatives. Copyright © 2002 John Wiley & Sons, Ltd.
Review: Synthesis of organometallics and catalytic hydrogenations in ionic liquids
Authors: Dyson Paul J.
Published: August 2002

New solvents provide synthetic chemists with the opportunity of conducting new reactions and carrying out new processes. In this paper the author's own work on organometallic chemistry in ionic liquids is reviewed and placed in context with studies from other groups in this area. Specifically, the paper will describe the use of ionic liquids in the synthesis of organometallic complexes and clusters and the use of ionic liquids in hydrogenation catalysis. The synthesis and reactivity of ionic liquids with organometallic anions will also be discussed. Copyright © 2002 John Wiley & Sons, Ltd.
N‐Pyrrolyl‐[N,N,N]‐bis(imino)pyridyl iron(II) and cobalt(II) olefin polymerization catalysts
Authors: Amort Christoph , Malaun Michael , Krajete Alexander , Kopacka Holger , Wurst Klaus , Christ Maria , Lilge Dieter , Kristen Marc O. , Bildstein Benno
Published: August 2002

A series of new [N,N,N] 2,6‐bis(imino)pyridyl iron and cobalt halide complexes as precatalysts for the homo‐ and co‐polymerization of ethylene has been synthesized and evaluated for their catalytic performance. The novel key structural feature of these [N,N,N]MCl2 catalysts is their peripheral substitution with bulky N‐heterocyclic groups, including substituted N‐pyrrolyl, N‐indolyl, N‐carbazolyl, and N‐triazolyl moieties. The synthesis starts with the corresponding N‐amino‐N‐heterocycles, which were prepared by a modified Paal–Knorr condensation of 1,4‐diketones with mono‐protected hydrazines, or by electrophilic amination of benzannelated azoles. Condensation with 2,6‐diacetylpyridine or 2,5‐diformylthiophene afforded 14 different terdentate ligands, and complex formation with iron(II), iron(III), cobalt(II) yielded 23 different precatalysts. A single crystal structure analysis of one representative showed that these paramagnetic complexes have a distorted trigonal bipyramidal structure with orthogonal sterically shielding N‐azolyl groups. All the methylalumoxane‐activated iron(II) and cobalt(II) complexes with N‐pyrrolyl, N‐indolyl, and N‐carbazolyl substituents are highly active catalysts for the homo‐ and co‐polymerization of ethylene, producing polymers with comparatively narrow molecular weight distributions and with a wide range of molecular weights, dependent on the substitution pattern of the peripheral N‐azolyl substituents. The observed microstructures of the polymers vary from very highly branched to mostly linear, giving access to oligomers and polymers with an unusual broad spectrum of macroscopic physical properties. Copyright © 2002 John Wiley & Sons, Ltd.
Oxidative dehydrodimerization of manganese vinylidene complexes (η5‐C5R5)(CO)(L)MnCCHPh (R = Me, L = CO; R = H, L = PPh3)
Authors: Novikova Lyudmila N. , Peterleitner Mikhail G. , Sevumyan Karine A. , Semeikin Oleg V. , Valyaev Dmitri A. , Ustynyuk Nikolai A.
Published: August 2002

The oxidative dehydrodimerization of the phenylvinylidene manganese complexes (η5‐C5R5)(CO)(L)MnCCHPh (5: R=Me, L=CO; 6: R=H, L=PPh3) into the corresponding bis‐vinylidene compounds (η5‐C5R5)(CO)(L)MnCCPhCPhCMn(CO)(L)(η5‐C5R5) (7: R=Me, L=CO; 8: R=H, L=PPh3) was studied by cyclic voltammetry and chemical experiments. It was found that dehydrodimerization of 5 and 6 proceeds via direct C(β)C(β) coupling of the radical cations 5
+· and 6
+· to give dicationic bis‐carbyne complexes [(η5‐C5R5)(CO)(L)Mn≡CCPhHCPhHC≡Mn(CO)(L)(η5‐C5R5)]2+ (10
++: R=Me, L=CO; 11
++: R=H, L=PPh3), which can be converted into bis‐vinylidene complexes 7 and 8 respectively by reduction with (η‐C6H6)2Cr. In this process, binuclear 19‐electron bis‐carbyne compounds 10
·· and 11
·· undergo further transformation into the dimers 7 and 8 via homolysis of C(β)H bonds of the bis‐carbyne ligand, thus exhibiting rare examples of reductive activation of CH bonds in 19‐electron transition metal carbyne complexes. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and biological activity of ‘3 + 1’ mixed ligand (3‐thiapentane‐1,5‐dithiolato)oxorhenium(V) complexes bearing 1,2,3,4‐tetrahydro(iso)quinoline and quinoline
Authors: Zablotskaya Alla , Segal Izolda , Germane Skaidrite , Shestakova Irina , Lukevics Edmunds , Kniess Torsten , Spies Hartmut
Published: August 2002

‘3 + 1’ mixed ligand oxorhenium(V) complexes of the type ReO(SSS)S(CH2)
nHetN have been synthesized by the reaction of the preliminary prepared tetrahydro(iso)quinolyl containing monodentate ligands with chloro(3‐thiapentane‐1,5‐dithiolato)oxorhenium(V). The newly synthesized ligands and complexes were characterized by elemental analysis, IR, 1H, and 13C NMR spectroscopy. Metal complexes were screened for psychotropic and antitumour activities and receptor‐binding properties and were found to be active in this respect. Copyright © 2002 John Wiley & Sons, Ltd.
Some platinum(II) complexes derived from aromatic alkynes
Authors: Bruce Michael I. , Davy Julianne , Hall Ben C. , Galen Yvonne Jansen van , Skelton Brian W. , White Allan H.
Published: August 2002

Several trans‐platinum(II) complexes, of the type R′{Pt(PBu3)2}R″{Pt(PR3)2}R′, where R′ and R″ are groups derived from a series of aromatic alkynes and diynes, have been prepared and characterized. Extensive spectroscopic data for these and other known related complexes are presented. A more precise structural study of trans‐Pt(C≡CC6H4C≡CPh)2(PBu3)2 (cf. Z. Kristallogr. 1998; 213: 483) is reported. Copyright © 2002 John Wiley & Sons, Ltd.
Di‐n‐butyltin aminoarylcarboxylates: structure, properties and in vitro antitumor activity
Authors: Pruchnik Florian P. , Bańbuła Małgorzata , Ciunik Zbigniew , Chojnacki Henryk , Latocha Małgorzata , Skop Barbara , Wilczok Tadeusz
Published: August 2002

The properties and structures of the tetranuclear dibutyltin complexes [Sn4(µ3‐O)2(C4H9‐n)8­{OOCC6H3(NH2)2‐3,4}4] (1), [Sn4(µ3‐O)2(C4H9‐n)8{OOCC6H3(NH2)2‐3,5}4] (2), [Sn4(µ3‐O)2(C4H9‐n)8­{OOC‐2‐C6H4NNC6H4N(CH3)2‐4}4] (3) are described. Complex 3 adopts a structure with a tetranuclear Sn4(µ3‐O)2 core. All tin atoms are five‐coordinate and form bonds with three oxygen atoms and two butyl ligands. Two carboxylates are bridging and two are terminal ligands. IR and NMR spectra indicate that the same structure is adopted by complexes 1 and 2. The molecular and electronic structures of complex 1 of C
i symmetry have been studied using the semi‐empirical PM3 formalism. The calculated structure and bond distances agree with X‐ray data. All complexes are effective antitumor agents. Copyright © 2002 John Wiley & Sons, Ltd.
UV laser photolysis of silacyclopent‐3‐ene: effect of admixtures on nature of chemically vapour‐deposited organosilicon films
Authors: Urbanová Markéta , Pola Josef
Published: August 2002

Examination of ArF laser‐induced gas‐phase photolysis of silacyclopent‐3‐ene, occuring as extrusion of silylene, in the presence of admixtures reveals that photolysis is not interfered with in the presence of N2, CO and CO2, but it is in the presence of O2, 2‐C4F8, CH3OH, CD3OH, CF3CH2OH and CH3CO2H. Formation of volatile products and solid deposited films incorporating fluorine or oxygen atoms is interpreted in terms of reactions of silylene with the admixtures. Copyright © 2002 John Wiley & Sons, Ltd.
Working methods paper: Micro‐scale preparation and characterization of isotopically enriched monomethylmercury
Authors: Rodríguez Martín‐Doimeadios R. C. , Stoichev T. , Krupp E. , Amouroux D. , Holeman M. , Donard O. F. X.
Published: August 2002

A synthesis method for the micro‐scale laboratory preparation of isotopically enriched monomethylmercury (MMHg) has been successfully established. This compound is an important standard for species‐specific isotope dilution analysis. The isotopically enriched MMHg has been synthesized from commercially available mercury oxide (201HgO) using methylcobalamin co‐enzyme as methylating agent. The time required is less than 2 h and the final yield is about 90%. The proposed method is faster than those previously reported in the literature. It allows work on a micro scale to control the use of expensive enriched isotope standard. It also allows control of unintentional formation of dimethylmercury. The enriched mercury‐containing reaction products were analyzed by capillary gas chromatography coupled to an inductively coupled plasma mass spectrometer after derivatization with sodium tetraethylborate. The isotopic composition, concentration, purity and stability of the synthesized, enriched MMHg have been investigated in order to establish standard protocols for MMHg isotope dilution analysis or isotope labeling incubation experiments. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and biological activity of novel N‐tert‐butyl‐N,N′‐substitutedbenzoylhydrazines containing 2‐methyl‐3‐(triphenylgermanyl)propoxycarbonyl
Authors: Wang Qing‐Min , Huang Run‐Qiu
Published: August 2002

In a search for new insect growth regulators with unusual biological properties and different activity spectrum, we thought that the preservation of the bioactive unit and the introduction of 2‐methyl‐3‐(triphenylgermanyl)propoxycarbonyl in N‐tert‐butyl‐N,N′‐dibenzoylhydrazine would enhance their larvicidal activities to a significant degree. Therefore, we designed and synthesized N′‐tert‐butyl‐N′‐[2‐methyl‐3‐(triphenylgermanyl)propoxycarbonyl]‐N‐benzoylhydrazine and analogs by two procedures. These novel compounds were characterized by elemental analyses, IR, and 1H NMR. At the same time, N‐tert‐butyl‐N‐substitutedbenzoylhydrazines were prepared by a new method, and some reactions involved were studied. The preliminary results indicate that some compounds have inhibitory effects against plant pathogenetic bacteria such as early blight of tomato. Copyright © 2002 John Wiley & Sons, Ltd.
Water–gas shift reaction catalyzed by mononuclear ruthenium complexes containing bipyridine and phenanthroline derivatives
Authors: Aguirre Pedro , Moya Sergio A. , Sariego Renato , Bozec Hubert Le , Pardey Alvaro J.
Published: August 2002

Ruthenium complexes of the type [RuL(CO)2Cl2], [RuL2Cl2], [RuL2(CO)(H2O)](PF6)2, [RuL2Cl]2(PF6)2, [RuL2(CO)Cl](PF6), and [RuL2(CO3)]·3H2O (where L is a bipyridine or phenanthroline derivative) dissolved in aqueous 2‐ethoxyethanol, and in a basic medium of KOH, triethylamine, or trimethylamine, catalyze the water‐gas shift reaction under mild conditions (PCO = 0.9 atm at 100 °C). Copyright © 2002 John Wiley & Sons, Ltd.
Comparison of relative viscosity measurement of polyvinylpyrrolidone in water by glass capillary viscometer and differential dual‐capillary viscometer
Authors: Wu Chi‐San , Senak Larry , Bonilla Jose , Cullen James
Published: August 2002

The relative viscosity (RV) of polyvinylpyrrolidone (PVP) with different molecular weights was measured with a glass capillary viscometer and with a differential dual‐capillary viscometer in water at different concentrations. For the differential dual‐capillary viscometer, RV increases with a decreasing flow rate, especially for high molecular weight PVP at a 1% concentration. A good agreement in the RV between the two methods can be obtained for PVP with different molecular weights and at various concentrations if an appropriate flow rate is selected for the differential dual‐capillary viscometer. Special precaution is needed when using the differential dual‐capillary viscometer to measure the viscosity of a pure solvent. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1312–1315, 2002
Production of hollow polymer particles by suspension polymerizations for ethylene glycol dimethacrylate/toluene droplets dissolving styrene–methyl methacrylate copolymers
Authors: Okubo M. , Konishi Y. , Inohara T. , Minami H.
Published: August 2002

Suspension polymerizations for ethylene glycol dimethacrylate (EGDM)/toluene droplets dissolving styrene–methyl methacrylate copolymers with different compositions were carried out. Hollow particles were obtained independent of the copolymer composition. In suspension copolymerizations for EGDM/divinyl benzene/toluene droplets dissolving poly(methyl methacrylate), hollow particles were produced at high EGDM content, but not at low EGDM content. Preferential adsorption of the polymer formed by the suspension polymerizations at the interfaces of the droplets over the (co)polymers preliminarily dissolved therein was one of the key factors for the formation of the hollow structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1087–1091, 2002
Synthesis of terpolymers having a phospholipid polar group and poly(oxyethylene) in the side chain and their protein adsorption–resistance properties
Authors: Oishi Tsutomu , Tanaka Hiroaki , Yamasaki Hirohito , Onimura Kenjiro
Published: August 2002

Terpolymers having phospholipid polar groups were synthesized from 2‐methacryloyloxyethyl phosphorylcholine (MPC), methacryloyl or acryloyl poly(oxyethylene) macromonomers (POEM) [(CH2CH2O)n (where n = 2–23); PEOM(2), PEOM(23), ME(9), Ph(6)], and n‐butyl methacrylate (BMA). The characteristics of these terpolymer membranes were investigated by water content (H) and X‐ray photoelectron spectroscopy. The content of water in the terpolymer increased with increasing content of MPC and length of oxyethylene units. The membranes of terpolymers were found to adsorb bovine serum albumin much less than those of poly(methyl methacrylate) and poly(BMA). Even though the contents of MPC in the terpolymer were 5 to 25 mol %, the terpolymer depressed BSA adsorption more than poly(MPC‐co‐BMA) consisting of 29 mol % of MPC. The use of terpolymer with POEM can decrease the amount of MPC in the polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1092–1105, 2002
Electrorheological properties of poly(lithium‐2‐acrylamido‐2‐methyl propane sulfonic acid) suspensions
Authors: Ünal Halil Ibrahim , Yilmaz Haşim
Published: August 2002

In this study, poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid) (PAMPS) was synthesized using potassium persulfate (K2S2O8) as initiator. PAMPS (Mn = 36,000 g/mol) was partially converted to a lithium salt (PAMPS–Li), and particle size was determined to be 40 μm. Suspensions of PAMPS–Li at various concentrations were prepared in silicone oil, mineral oil, dioctylphthalate (DOP), and trioctyltrimellitate (TOTM) insulating oils. Colloidal stabilities of these suspensions were determined at 20 and 80°C. The PAMPS–Li suspensions were observed to provide an electrorheological (ER) response upon the application of an external dc electric field. ER properties of these suspensions were investigated at various shear rates (γ˙) and electric field strengths (E). Further, effects of polar promoters and high temperature on ER activity were determined, and excess shear stresses (Δτ) were calculated. A shear‐thinning non‐Newtonian viscoelastic behavior was observed for the PAMPS–Li suspensions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1106–1112, 2002
Modeling of “living” free‐radical polymerization processes. II. Tubular reactors
Authors: Zhang Min , Ray W. Harmon
Published: August 2002

A tubular reactor model for “living” free‐radical polymerization is developed in this study. The model may be used as a tool to design efficient processes for tailored polymers from “living” free‐radical polymerization. Examples presented include preparing bimodal polymers and copolymers of n‐butyl acrylate and styrene. Residence time distribution effects on polymer properties are investigated by varying the Peclet number, to show the degree of backmixing that adversely affects polymer properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1047–1056, 2002
Multilayered polymer particles. I. Synthesis of hydrophilic poly(dimethyl aminoethyl methacrylate) core particles
Authors: Sangsirimongkolying Ratsamee , Kiatkamjornwong Suda , Damronglerd Somsak , Ma Guang‐Hui , Omi Shinzo
Published: August 2002

Hydrophilic poly(dimethyl aminoethyl methacrylate) (PDMAEMA) copolymer was obtained by suspension polymerization using 2,2′‐azobisisobutyronitrile as an initiator, and by emulsion polymerization using 2,2′‐azobis(2‐amidinopropane)·2HCl (V‐50). The influences of reaction parameters on the particle size and size distribution were investigated. For suspension polymerization, these included the concentrations of ethylene glycol dimethacrylate (EGDMA) crosslinking agent, ethyl acetate (EA), and Na2SO4 electrolyte, the types of comonomer [methyl methacrylate (MMA) or styrene (ST)], solvent (EA or acetone), and stabilizer [poly(oxyethylene nonylphenylether) with 23 units of ethylene oxide (PEO23) or polyvinylpyrrolidone K30 (PVP)], polymerization temperature, and ST content in the comonomer feed. For the emulsion polymerization, the reaction parameters included the concentration of cetyltrimethyl ammonium chloride and V‐50, and types of initiator [V‐50 or potassium persulfate] and crosslinking agent [EGDMA or divinylbenzene]. The solubility of hydrophilic comonomers in the aqueous phase was a key factor for the stability and morphology of the PDMAEMA particles. It was found that the stable uncrosslinked PDMAEMA latex could be prepared by charging 20 wt % (based on the monomer) of ST. Moreover, the crosslinking agent significantly affected the coagulum in both the suspension and the emulsion polymerizations. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1057–1070, 2002
Miscibility and thermal properties of blends of polystyrene with poly(5‐benzoyl‐2,6‐dimethyl‐1,4‐phenylene oxide) or poly(5‐acetyl‐2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Kim Gue‐Hyun , Shin Hack‐Gi , Cho Won‐Jei , Ha Chang‐Sik
Published: August 2002

Miscibility and thermal properties of blends of polystyrene (PS) with poly(5‐benzoyl‐2,6‐dimethyl‐1,4‐phenylene oxide) (BPPO) or poly(5‐acetyl‐2,6‐dimethyl‐1,4‐phenylene oxide) (APPO) were investigated using light scattering, FTIR spectroscopy, and thermogravimetric analysis. The optical clarity and light‐scattering behavior showed that both BPPO/PS blends and APPO/PS blends cast from chloroform were miscible over the entire composition ranges in part because of the van der Waals interaction between the component polymers. The light‐scattering studies showed that the miscibility of the APPO/PS blend is better than that of the BPPO/PS blend. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1071–1076, 2002