bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alkali Cation Ligating Chains and Sheets of the Macrocycle 1, 7‐Dithia‐18‐Crown‐6 with Bridging Iodo‐ and Thiocyanatocuprate(I) Units
Authors: Heller M. , Sheldrick W. S. 
Published: August 2003

AbstractTreatment of an acetonitrile solution of CuI with 1, 7‐dithia‐18‐crown‐6 (1, 7‐DT18C6) at 100°C affords the coordination polymer 1[(CuI)2(1, 7‐DT18C6)2] (1) in which 1, 7‐DT18C6 ligands bridge (CuI)2 rings into double chains. 1D polymers of the type 1[M{(Cu3I4)(1, 7‐DT18C6)}] (M = K, 2; M = Cs, 3) can be isolated under similar conditions in the presence of respectively KI and CsI. Both contain bridging heptacyclic [Cu6I8]2— units but crystallise in different space groups, namely P1 and C2/m. The cesium cation of 3 is markedly displaced from the best plane through the thiacrown ether donor atoms. Reaction of 1, 7‐DT18C6 with CuSCN in the presence of NaSCN yields 2[{Na(CH3CN)2} {(CuSCN)2(1, 7‐DT18C6)}][Cu(SCN)2] (4), in which 1[(CuSCN)2] double chains are linked through macrocycles into sheets. Infinite 1[{Cu(SCN)2}—] chains compensate the charge of the Na+ cations. Complex 1 can imbibe 0.90 mol CsNO3 per mol of 1, 7‐DT18C6 pairs.
Affinity of Divalent Mercury Towards Nitrogen Donor Ligands
Authors: Meyer Gerd , Nockemann Peter 
Published: August 2003

AbstractAs with gold, relativistic effects are important in the chemistry of mercury. Together with the closed‐shell d10 configuration of Hg2+ they account for the special bonding schemes as preferred linear coordination with highly covalent contributions to chemical bonding or special affinities to nitrogen and sulfur that are so prominent in mercuric chemistry. This research report summarizes recent research on coordination compounds with halogen, oxygen and, especially, nitrogen as direct bonding partners of divalent mercury and their competition with each other. In a rather systematic way N‐donor ligands with one, two and more than two nitrogen atoms have been inspected in order to elucidate the influences that lead to the special bonding schemes of HgII‐N compounds.
Zur Kinetik der Bildung von Na2PdC2
Authors: Ruschewitz Uwe , Bähtz Carsten , Knapp Michael 
Published: August 2003

AbstractDie Kinetik der Bildung von Na2PdC2 aus Na2C2 und Palladium wurde pulverdiffraktometrisch mit Synchrotronstrahlung (Pulverdiffraktometer der Beamline B2, HASYLAB/Hamburg) zeitaufgelöst bei verschiedenen Reaktionstemperaturen zwischen 513 und 533 K untersucht. Durch Rietveld‐Analyse der erhaltenen Diffraktogramme konnte der molare Anteil des Produkts Na2PdC2 in Abhängigkeit von der Zeit bestimmt werden. Die so erhaltenen Kristallisationskurven wurden mit Hilfe der Avrami‐Erofe'ev‐Theorie analysiert. Es zeigte sich, dass die untersuchte Reaktion diffusionskontrolliert abläuft. Die Aktivierungsenergie wurde zu EA = 480(120) KJ/mol bestimmt. Gründe für die relativ hohe Ungenauigkeit bei der Bestimmung der Aktivierungsenergie werden diskutiert.
Pharmacological rationale for the use of somatostatin and analogues in portal hypertension
Authors: Reynaert H. , Geerts A. 
Published: August 2003

SummarySomatostatin and its analogue octreotide have been used for two decades to treat oesophageal variceal haemorrhage. The drug was introduced because of its capacity to decrease portal venous pressure without major side effects. In clinical trials assessing the efficacy of somatostatin and long‐acting analogues in arresting variceal haemorrhage, conflicting results have been obtained. Furthermore, in haemodynamic studies evaluating the effects of somatostatin and analogues in patients with cirrhosis, divergent effects were observed. The main reason for these differences is probably related to different affinities of the drugs for different somatostatin receptor subtypes. The effects of somatostatin and analogues are mediated via five different G‐protein coupled receptors (somatostatin receptor subtypes 1–5), which regulate the activity of ion channels (Ca2+, K+, Na+ and Cl–) and enzymes (adenyl cyclase, phospholipase C, phospholipase A2, phosphoinositide 3‐kinase and guanylate cyclase) responsible for the synthesis or degradation of intracellular second messengers including cyclic AMP, inositol 1,4,5‐trisphosphate, diacylglycerol and cyclic GMP. Despite universal use of somatostatin, the cellular and biochemical mechanisms of its effects in portal hypertension are relatively poorly studied and remain incompletely understood. In this review, we summarize relevant signal transduction of somatostatin and analogues, the haemodynamic effects of the drugs and the possible mechanisms by which these effects are mediated.
Nutritional therapy in alcoholic liver disease
Authors: Stickel F. , Hoehn B. , Schuppan D. , Seitz H. K. 
Published: August 2003

SummaryChronic alcohol consumption may lead to primary and secondary malnutrition. In particular, protein energy malnutrition not only aggravates alcoholic liver disease but also correlates with impaired liver function and increased mortality. Therefore, in these patients, adequate nutritional support should be implemented in order to improve their prognosis. Clinical trials addressing this issue have shown that nutritional therapy either enterally or parenterally improves various aspects of malnutrition, and there is increasing evidence that it may also improve survival. Therefore, malnourished alcoholics should be administered a diet rich in carbohydrate‐ and protein‐derived calories preferentially via the oral or enteral route. Micronutrient deficiencies typically encountered in alcoholics, such as for thiamine and folate, require specific supplementation. Patients with hepatic encephalopathy may be treated with branched‐chain amino acids in order to achieve a positive nitrogen balance. Fatty liver represents the early stage of alcoholic liver disease, which is usually reversible with abstinence. Metadoxine appears to improve fatty liver but confirmatory studies are necessary. S‐adenosyl‐l‐methionine may be helpful for patients with severe alcoholic liver damage, since various mechanisms of alcohol‐related hepatotoxicity are counteracted with this essential methyl group donor, while a recent large trial showed that the use of polyenylphosphatidylcholine is of limited efficacy.
Effect of oral tacrolimus (FK 506) on steroid‐refractory moderate/severe ulcerative colitis
Authors: Högenauer C. , Wenzl H. H. , Hinterleitner T. A. , Petritsch W. 
Published: August 2003

AbstractBackground : Steroid refractory ulcerative colitis is most commonly treated with intravenous ciclosporin to avoid colectomy. In search for an alternative drug that can be administered orally we investigated oral tacrolimus (FK 506) for this indication.Methods : Nine patients with active, moderate/severe steroid refractory UC were treated with oral tacrolimus with a daily dose of 0.15 mg/kg body weight. After patients had responded azathioprine was added for long‐term immunosuppression.Results : All patients responded within 1–2 weeks. After 12 weeks of tacrolimus therapy six patients (67%) were in complete remission, two patients (22%) had mild to moderate disease activity, and one patient (11%) underwent colectomy. After a mean follow up of 21 months six of the nine patients (67%) had their colon in situ. Two patients developed severe side‐effects, one thrombopenia with intestinal bleeding, and one bicytopenia. Mild side‐effects were common.Conclusion : Oral tacrolimus may be an effective alternative to intravenous ciclosporin for the therapy of steroid‐refractory ulcerative colitis. Patients receiving tacrolimus need to be watched carefully for side‐effects.
Response to infliximab is related to disease duration in paediatric Crohn's disease
Authors: Lionetti P. , Bronzini F. , Salvestrini C. , Bascietto C. , Canani R. Berni , Dé Angelis G. L. , Guariso G. , Martelossi S. , Papadatou B. , Barabino A. 
Published: August 2003

SummaryBackground : Infliximab is an effective therapy in adult patients with refractory and fistulizing Crohn's disease. Experience in children is still limited.Aim : To evaluate the experience in 22 children and adolescents treated with infliximab with refractory and/or fistulizing Crohn's disease, and to compare duration of response in children between early Crohn's disease and late Crohn's disease.Methods : The experience in 22 children and adolescents treated with a total of 73 infusions was evaluated retrospectively. Treatment indication was refractory Crohn's disease in 9/22 patients, fistulizing Crohn's disease in 7/22 patients and both these conditions in 6/22. All patients with refractory Crohn's disease had late Crohn's disease (> 1 year), whereas 6/13 patients with fistulas had early disease (< 1 year).Results : Mean Paediatric Crohn's Disease Activity Index (PCDAI) decreased from 41.2 to 16.2 at 4 weeks (P < 0.01), and to 15.4 at 18 weeks (P < 0.01). Mean PCDAI at 18 weeks in children with early Crohn's disease and late Crohn's disease was 5.5 and 18.1, respectively (P < 0.05). Complete closure of fistulas was obtained in 5/6 children with early Crohn's disease and in 2/7 children with late Crohn's disease. Immediate adverse reactions were observed in two children.Conclusions : Infliximab is a highly effective treatment in children and adolescents with both severe refractory or fistulizing Crohn's disease. Children with early Crohn's disease have a higher chance of prolonged response to infliximab than children with late Crohn's disease.
Tioguanine in patients with Crohn's disease intolerant or resistant to azathioprine/mercaptopurine
Authors: Bonaz B. , Boitard J. , Marteau P. , LÉmann M. , Coffin B. , Flourié B. , Belaiche J. , Cadiot G. , Metman E.‐H. , Cortot A. , Colombel J.‐F. ,   Getaid
Published: August 2003

SummaryBackground:  Tioguanine (TG) is an antimetabolite which may be regarded as an alternative to azathioprine (AZA)/mercaptopurine (MP) in patients with inflammatory bowel diseases.Aims : To evaluate the tolerance and efficacy of TG in patients with Crohn's disease, intolerant or resistant to AZA/MP.Methods : An open prospective study was made on Crohn's disease patients treated with TG. Intolerance to AZA/MP was defined as a reaction occurring within 1 month after introduction of AZA/MP, including pancreatitis, abdominal pain, fever, arthralgia, myalgia, cutaneous rash, fatigue, alopecia, hepatitis and digestive intolerance. Resistance to AZA/MP was defined as the persistence of activity after at least 3 months of AZA/MP therapy.Results : Forty‐nine Crohn's disease patients (36 women, 13 men; intolerance: n = 39; resistance: n= 10) were treated with TG (20 mg/day). Clinical pancreatitis did not recur under TG. Five patients (10%) had to stop TG due to intolerant reactions observed 13–21 days after TG was started. No haematological side‐effects were observed under TG. The probability of clinical remission without corticosteroids or infliximab at 6 and 12 months was 46% and 79%, respectively, in the 40 patients with active disease at baseline. The probability of clinical relapse during maintenance TG therapy at 6 and 12 months was 29% and 53%, respectively, in the 28 patients in remission at baseline or who had achieved remission on TG.Conclusions : TG is a possible alternative treatment in Crohn's disease patients, intolerant (especially for pancreatitis) or resistant to AZA/MP.
Thiopurine S‐methyltransferase (TPMT) genotype does not predict adverse drug reactions to thiopurine drugs in patients with inflammatory bowel disease
Authors: Gearry R. B. , Barclay M. L. , Burt M. J. , Collett J. A. , Chapman B. A. , Roberts R. L. , Kennedy M. A. 
Published: August 2003

SummaryBackground : Azathioprine and mercaptopurine (MP) are well established treatments for inflammatory bowel disease but they have severe adverse effects that prevent their use in some patients. The likelihood and type of adverse effect may relate to thiopurine methyltransferase (TPMT) enzyme activity and genotype.Aim : To compare the TPMT genotype frequencies in patients with inflammatory bowel disease who have had severe adverse effects to those who tolerate azathioprine or MP (controls).Methods : Patients with inflammatory bowel disease who had been treated with azathioprine or MP in Christchurch between 1996 and 2002 were identified. Patients with adverse effects, and controls, were invited to provide a peripheral blood sample for analysis of TPMT genotype. The genotype frequencies were then compared between the two groups.Results : Fifty‐six patients were identified with adverse effects requiring cessation of therapy, of which 50 were genotyped. Reactions included allergic‐type (25%), hepatitis (33%), nausea/vomiting (14%), bone marrow suppression (10%), pancreatitis (6%) and other (12%). Five of 50 patients with reactions had TPMT genotype *1/*3, one had *3/*3, and the rest had the wildtype genotype *1/*1. The patient with genotype *3/*3 had severe pancytopenia requiring hospitalization. Three of 50 controls had the *1/*3 genotype and the rest were *1/*1.Conclusions : The TPMT allele frequency in our population with inflammatory bowel disease is similar to that reported elsewhere. There was a slight trend for more frequent TPMT mutations in the patients with adverse reactions, but this was not statistically significant. Most patients with reactions did not have gene mutations.
High incidence of clopidogrel‐associated gastrointestinal bleeding in patients with previous peptic ulcer disease
Authors: Ng F. H. , Wong S. Y. , Chang C. M. , Chen W. H. , Kng C. , Lanas A. I. , Wong B. C. Y. 
Published: August 2003

SummaryBackground:  In average‐risk patients, the new anti‐platelet agent, clopidogrel, causes less upper gastrointestinal adverse events than aspirin. However, there are no safety data on the use of clopidogrel in high‐risk patients.Aim:  To evaluate the safety of clopidogrel in patients with peptic ulcer disease in a retrospective cohort longitudinal study.Methods:  During the period from January 2000 to May 2002, 70 patients who were prescribed clopidogrel (75 mg/day) for a previous history of non‐aspirin‐related peptic ulcer disease or a history of aspirin‐related gastrointestinal complications (dyspepsia or peptic ulcer) were recruited. The occurrence of ulcer complications (bleeding/perforation/obstruction) was the primary end‐point.Results:  After a median follow‐up of 1 year, nine patients (12%) developed gastrointestinal bleeding and one had a perforated peptic ulcer. Clopidogrel‐associated gastrointestinal bleeding was significantly more common in patients with a history of gastrointestinal bleeding than in those without (22% vs. 0%; P = 0.007; odds ratio, 1.3; 95% confidence interval, 1.1–1.5).Conclusions:  Clopidogrel is associated with a high incidence of upper gastrointestinal bleeding in high‐risk patients. A previous history of gastrointestinal bleeding appears to be a predictor of adverse gastrointestinal events.
Health‐related quality of life in functional dyspepsia
Authors: El‐Serag H. B. , Talley N. J. 
Published: August 2003

SummaryBackground : We performed a systematic review of the literature to compare the health‐related quality of life (HRQOL) of patients with functional dyspepsia with either healthy controls or those with other diseases.Methods : Full‐length published manuscripts during 1980–2002 were included if (a) patients had functional dyspepsia, but not uninvestigated dyspepsia; and (b) HRQOL was measured using a validated generic or dyspepsia‐specific instruments, but not global assessment alone.Results : Twelve studies were reviewed; six fulfilled the selection criteria. None examined HRQOL among samples of the general population. None used dyspepsia‐specific HRQOL instruments. Three studies contained four comparisons of HRQOL between functional dyspepsia patients and controls; two studies examined HRQOL changes in response to therapy. Two studies demonstrated a significant reduction at least in some domains of HRQOL among patients with functional dyspepsia compared to controls, while one study was negative. In general, studies that reported a decline in HRQOL Short Form‐36 (SF‐36) showed that changes in the physical domain were similar to those on mental domain of the SF‐36.Conclusions : There is some evidence for a decrease in HRQOL in patients with moderate to severe functional dyspepsia who seek care for their symptoms; however, more studies are needed. A therapeutic response in functional dyspepsia‐related pain or discomfort might result in a corresponding improvement in HRQOL.
Essential fatty acid status in paediatric Crohn's disease: relationship with disease activity and nutritional status
Authors: Trebble T. M. , Wootton S. A. , May A. , Erlewyn‐Lajeunesse M. D. S. , Chakraborty A. , Mullee M. A. , Stroud M. A. , Beattie R. M. 
Published: August 2003

SummaryBackground:  Active paediatric Crohn's disease is associated with nutritional deficiencies and altered nutrient intake. The availability of essential fatty acids (linoleic and α‐linolenic acids) or their derivatives (arachidonic and eicosapentaenoic acids) may alter in plasma and cell membrane phospholipid in protein‐energy malnutrition in children and in Crohn's disease in adults.Aim:  To investigate the relationship of fatty acid phospholipid profiles with disease activity and nutritional status in paediatric Crohn's disease.Methods:  The fatty acid (proportionate) composition of plasma and erythrocyte phosphatidylcholine was determined in 30 patients (10.3–17.0 years) stratified into active and quiescent Crohn's disease (paediatric Crohn's disease activity index) and high and low body mass (body mass index centile).Results:  In plasma phosphatidylcholine, active disease activity was associated with a lower level of α‐linolenic acid compared with that in quiescent disease (P < 0.05). A body mass index below the 50th centile was associated with active Crohn's disease, low linoleic and α‐linolenic acids and high arachidonic acid (P < 0.05) in plasma phosphatidylcholine, and low α‐linolenic acid in erythrocyte phosphatidylcholine. These findings could not be explained through differences in habitual dietary fat intake.Conclusion:  In paediatric Crohn's disease, a low body mass index centile and high disease activity are associated with altered profiles of essential fatty acids and their derivatives, which may reflect altered metabolic demand.
Hydrostatic balloon dilatation of Crohn's strictures
Authors: Sabaté J.‐M. , Villarejo J. , Bouhnik Y. , Allez M. , Gornet J.‐M. , Vahedi K. , Modigliani R. , Lémann M. 
Published: August 2003

SummaryAim : To evaluate the safety and long‐term efficacy of per‐endoscopic hydrostatic balloon dilatation in a retrospective series of patients with Crohn's disease.Methods : Thirty‐eight patients had balloon dilatation for intestinal symptomatic strictures which were located as follows: ileo‐colonic (26) or colocolic (2) anastomosis, colon (4), ileum (3), proximal jejunum (1) and ileo‐caecal valve (5); three patients had two strictures accessible to dilatation. The mean length of the strictures was 2.1 cm (s.d., 0.3 cm).Results: Thirty‐two of the 38 patients were successfully dilated and followed for a median of 22.8 months (0.2–103 months) until surgery or last news. The probabilities of obstructive symptom recurrence were 36% at 1 year and 60% at 5 years. Twelve patients had a second dilatation, and three a third. The probabilities of surgery for stricture were 26% at 1 year and 43% at 5 years. Results were not influenced by age, sex, activity of the disease, passage of the stricture by the colonoscope or concomitant medical therapies. Complications occurred in 9.4% of the 53 dilatation sessions, with only one perforation.Conclusions : Hydrostatic balloon dilatation is effective for Crohn's symptomatic strictures, and can avoid or postpone surgery, with an acceptable rate of complications.
Shallow‐marine sequences as the building blocks of stratigraphy: insights from numerical modelling
Authors: Storms Joep E. A. , Swift Donald J. P. 
Published: August 2003

AbstractTwo types of depositional sequences can be defined within the sequence stratigraphic framework: the parasequence and the high‐frequency sequence. Both sequences consist of stacked regressive and transgressive deposits. However, a parasequence forms under conditions of overall sea‐level rise, whereas a high‐frequency sequence forms as the sea level oscillates which results in typical forced regressive deposits during sea‐level fall. Both depositional sequences may develop over comparable temporal (10–100 kyr) and spatial (1–20 km wide and 1–40 m thick) scales. Numerical modelling is used to compare the architecture, preservation potential, internal volumes, bounding surfaces, condensed and expanded sections and facies assemblages of parasequences and high‐frequency sequences. Deposits originating from transgression are less pronounced than their regressive counterparts and consist of either preserved backbarrier deposits or shelf deposits. Shoreface deposits are not preserved during transgression. The second half of the paper evaluates in detail the preservation potential of backbarrier deposits and proposes a mechanism that explains the occurrence of both continuous and discontinuous barrier retreat in terms of varying rates of sea‐level rise and sediment supply. The key to this mechanism is the maximum washover capacity, which plays a part in both barrier shoreline retreat and backbarrier‐lagoonal shoreline retreat. If these two shorelines are not balanced, then the retreat of the coastal system as a whole is discontinuous and in time barrier overstep may take place.
Provenance patterns in a neotectonic basin: Pliocene and Quaternary sediment supply to the South Caspian
Authors: Morton Andrew , Allen Mark , Simmons Mike , Spathopoulos Fivos , Still John , Hinds David , Ismail‐Zadeh Arif , Kroonenberg Salomon 
Published: August 2003

AbstractThe South Caspian Basin has accumulated a sedimentary succession ∼20 km thick. Roughly half of this was deposited in the last 5.5 Ma, mainly in the largely lower Pliocene, fluvio‐lacustrine Productive Series, which is also the principal hydrocarbon reservoir succession in the basin. Heavy mineral data identify different sediment sources for both Productive Series sandstones and modern river sands. Lesser Caucasus sediment was supplied by the Palaeo‐Kura into the western part of the South Caspian Basin. Productive Series strata in the north of the basin were supplied by the Palaeo‐Volga, and represent a mixture of sediment from the Greater Caucasus and Russian Platform/Urals. Greater Caucasus sand input to the Palaeo‐Volga increased at the start of deposition of the Pereriva Suite, which is an important reservoir subunit of the Productive Series. We interpret this provenance shift as indicating enhanced uplift and exhumation of the Greater Caucasus within the Pliocene, during regional re‐organization of the Arabia–Eurasia collision, although late Cenozoic climate changes may have played a role.