bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification and Characterization of a Transcription Pause Site in Rotavirus
Authors: Lawton Jeffrey A. , Estes Mary K. , Prasad B. V. Venkataram
Published: July 2002

In rotavirus, transcription of the 11 double-stranded RNA genome segments occurs within the structurally intact subviral particle, and nascent transcripts are released through channels penetrating the two capsid layers at the icosahedral vertices. To gain insight into the early molecular events in transcription, we used high-resolution polyacrylamide gel electrophoresis to investigate the length distribution of transcription products at various times following initiation. We observed that, in the subviral particle under normal conditions, transcript initiation and capping are followed by a momentary pause in elongation after the addition of 6 to 7 nucleotides. In the absence of the capping reaction cofactor
S
-adenosylmethionine, conditions under which the rate of nucleotide incorporation is reduced, we observe a significant decrease in the ratio of paused to full-length transcripts. We propose that this pause site may represent the point at which specific molecular events take place to facilitate processive elongation. Furthermore, our results indicate that the presence of specific ligands on the viral surface, such as VP7 in the mature virion, inhibits polymerase function. From the perspective of the viral replication cycle, this inhibition may serve to ensure that transcription occurs with greatest efficiency only after the virus has entered the cytoplasm and assumed the form of a double-layered particle.
Critical Role for Env as well as Gag-Pol in Control of a Simian-Human Immunodeficiency Virus 89.6P Challenge by a DNA Prime/Recombinant Modified Vaccinia Virus Ankara Vaccine
Authors: Amara Rama Rao , Smith James M. , Staprans Silvija I. , Montefiori David C. , Villinger Francois , Altman John D. , O'Neil Shawn P. , Kozyr Natalia L. , Xu Yan , Wyatt Linda S. , Earl Patricia L. , Herndon James G. , McNicholl Janet M. , McClure Harold M. , Moss Bernard , Robinson Harriet L.
Published: July 2002

Cellular immune responses against epitopes in conserved Gag and Pol sequences of human immunodeficiency virus type 1 have become popular targets for candidate AIDS vaccines. Recently, we used a simian-human immunodeficiency virus model (SHIV 89.6P) with macaques to demonstrate the control of a pathogenic mucosal challenge by priming with Gag-Pol-Env-expressing DNA and boosting with Gag-Pol-Env-expressing recombinant modified vaccinia virus Ankara (rMVA). Here we tested Gag-Pol DNA priming and Gag-Pol rMVA boosting to evaluate the contribution of anti-Env immune responses to viral control. The Gag-Pol vaccine raised frequencies of Gag-specific T cells similar to those raised by the Gag-Pol-Env vaccine. Following challenge, these rapidly expanded to counter the challenge infection. Despite this, the control of the SHIV 89.6P challenge was delayed and inconsistent in the Gag-Pol-vaccinated group and all of the animals underwent severe and, in most cases, sustained loss of CD4
+
cells. Interestingly, most of the CD4
+
cells that were lost in the Gag-Pol-vaccinated group were uninfected cells. We suggest that the rapid appearance of binding antibody for Env in Gag-Pol-Env-vaccinated animals helped protect uninfected CD4
+
cells from Env-induced apoptosis. Our results highlight the importance of immune responses to Env, as well as to Gag-Pol, in the control of immunodeficiency virus challenges and the protection of CD4
+
cells.
Subtle Alterations of the Native Zinc Finger Structures Have Dramatic Effects on the Nucleic Acid Chaperone Activity of Human Immunodeficiency Virus Type 1 Nucleocapsid Protein
Authors: Guo Jianhui , Wu Tiyun , Kane Bradley F. , Johnson Donald G. , Henderson Louis E. , Gorelick Robert J. , Levin Judith G.
Published: July 2002

The nucleocapsid protein (NC) of human immunodeficiency virus type 1 has two zinc fingers, each containing the invariant CCHC zinc-binding motif; however, the surrounding amino acid context is not identical in the two fingers. Recently, we demonstrated that zinc coordination is required when NC unfolds complex secondary structures in RNA and DNA minus- and plus-strand transfer intermediates; this property of NC reflects its nucleic acid chaperone activity. Here we have analyzed the chaperone activities of mutants having substitutions of alternative zinc-coordinating residues, i.e., CCHH or CCCC, for the wild-type CCHC motif. We also investigated the activities of mutants that retain the CCHC motifs but have mutations that exchange or duplicate the zinc fingers (mutants 1-1, 2-1, and 2-2); these changes affect amino acid context. Our results indicate that in general, for optimal activity in an assay that measures stimulation of minus-strand transfer and inhibition of nonspecific self-priming, the CCHC motif in the zinc fingers cannot be replaced by CCHH or CCCC and the amino acid context of the fingers must be conserved. Context changes also reduce the ability of NC to facilitate primer removal in plus-strand transfer. In addition, we found that the first finger is a more crucial determinant of nucleic acid chaperone activity than the second finger. Interestingly, comparison of the in vitro results with earlier in vivo replication data raises the possibility that NC may adopt multiple conformations that are responsible for different NC functions during virus replication.
Photocolouration of 2,4,4,6-Tetraaryl-1,4-dihydropyridines: A Semiempirical Quantum Chemical Study
Authors: Böhm Stanislav , Hocek Michal , Nešpůrek Stanislav , Kuthan Josef
Published: July 2002

Molecular geometries of 1,4-dihydropyridines Ia, Ib and their possible photoisomers IIa - Va and IIb - Vb were optimized by the PM3 method. The electronic absorption spectra were calculated by the CNDO/S-CI procedure and compared with the experimental spectroscopic data. A probable mechanism of the photocolouration of Ia, Ib, caused by sunlight or UV illumination, is proposed, and structures IIIa, IIIb are assigned to violet or green coloured species.
Influence of Reacting Atmosphere on Isothermal Decomposition of Ammonium Metavanadate
Authors: Amin Anwar , Philip Christine A. , Girgis Badie S.
Published: July 2002

Ammonium metavanadate (AMV) was decomposed under pure oxygen, air, nitrogen, vacuum and controlled humidity, in the temperature range of 453 to 623 K. Three well established limiting conversions appear corresponding to the formation of ammonium tetravanadate at 453 K (50%), ammonium hexavanadate at 503 K (67%), and V2O5 at 623 K (100%). Oxidizing atmospheres have a retarding effect at 453 K but an accelerating one at 573 to 623 K, as observed from the reaction limiting time and rate constant. In addition to H2O and N2, oxygen plays an important role in the oxidation of ammonia to N2, and in the proton transfer process.
Sorption Kinetics of p-Ethyltoluene in NaH-ZSM-5 Crystals-Simultaneous Effect of Intracrystalline Diffusion and a Mass Transport Resistance within the Crystal Surface
Authors: Micke André , Struve Peter , Bülow Martin , Kočiřík Milan , Zikánová Arlette
Published: July 2002

Adsorption equilibrium and sorption uptake data have been measured for the system p-ethyltoluene/NaH-ZSM-5 zeolite under constant volume/variable pressure condition at elevated ambient temperature of 343 K. The equilibrium data are described by a superposition of two Langmuir isotherms. The uptake curves observed in the present paper revealed devations from the second Fick law behaviour. The experimental uptake curves are compatible with rate mechanism involving Fickian diffusion superimposed by a surface barrier. The evaluation of the model parameters was carried out by simulation of the kinetic curves that include both the interactions of the system with the apparatus and the intrinsic sorption kinetics. The dependence of the fitted model parameters on sorbent amount and pressure, respectively, is consistent with Langmuir sorption kinetics at crystal surface on one side and with the concept of molecule jumps on a system of fixed positions in the crystal bulk on the other.
Acyclic Nucleoside and Nucleotide Analogs Derived from 2-Azaadenine
Authors: Hocková Dana , Masojídková Milena , Buděšínský Miloš , Holý Antonín
Published: July 2002

Alkylation of cesium salt of 2-azaadenine with appropriate synthons afforded the following acyclic analogs of nucleosides and nucleotides: (S)-9-(2,3-dihydroxypropyl)-2-azaadenine (VI), 3-(2-azaadenin-9-yl)-2-hydroxypropanoic acid (VIII), 9-(2-phosphonomethoxyethyl)-2-azaadenine (Xb), (R)-9-(2-phosphonomethoxypropyl)-2-azaadenine (XIb) and (S)-9-(3-hydroxy-2-phosphonomethoxypropyl)-2-azaadenine (XVIb). In some cases the N-2 isomers were also isolated.
Supported Heteropolyacids as Heterogeneous Catalysts for Propene Metathesis
Authors: Hudec Pavol , Prandová Katarina
Published: July 2002

Catalysts containing tungsten or molybdenum in the form of Keggin type heteropolyacids, like H3PW12O40, H4SiW12O40 and H3PMo12O40, supported on silica gel were prepared. The acid and surface properties of heteropolyacids and their supported forms are discussed. Keggin type heteropolyacids supported on silica gel have been found active for propene metathesis, the activity was compared with those of the classical catalyst WO3/SiO2. The highest activity and selectivity for studied reaction showed catalyst prepared on the base of H3PW12O40.
29Si NMR Study of Distribution of Oligomers in Polycondensation of Tetraethoxysilane
Authors: Brus Jiří , Karhan Jiří , Kotlík Petr
Published: July 2002

29Si NMR spectrometry has been used to determine the number molecular weight distribution of polymerization degrees of a system of oligomers formed in the sol-gel polycondensation of tetraethoxysilane (TEOS). On the basis of identification of the oligomers, monitoring of the concentration changes during the initial phase of the sol-gel polycondensation, and from the deviations observed between the experimentally determined number molecular weight distribution of polymerization degrees and the Flory-Stockmayer model it has been proved that cyclization represents a significant process in the acid-catalyzed polycondensation with substoichiometric amount of water (ratio of amounts TEOS/H2O = 1 : 1). The cyclization becomes important at the moment when the reaction mixture contains increased amounts of the linear tetramer and pentamer. The cyclization products form a basis for formation of polycyclic, highly condensed building units whose gradual aggregation produces the gel.
Some Reactions of the Products of Reactions of 1,4-Bis(trimethylsilyl)-1,3-butadiyne with Titanoceneand Zirconocene
Authors: Burlakov Vladimir V. , Peulecke Normen , Baumann Wolfgang , Spannenberg Anke , Kempe Rhett , Rosenthal Uwe
Published: July 2002

Bis(η5-cyclopentadienyl)-2,4-bis(trimethylsilylethynyl)-3,5-bis(trimethylsilyl)titanacyclopenta-2,4-diene (1) and the seven-membered zirconacyclocumulene bis(η5-cyclopentadienyl)-2,4,7-tris(trimethylsilyl)-3-(trimethylsilylethynyl)zirconacyclohepta-2,4,5,6-tetraene (2) react with sulfur monochloride to yield an identical product, 2,4-bis(trimethylsilylethynyl)-3,5-bis(trimethylsilyl)thiophene (3). A one-to-one mixture of the homo- and heterobimetallic bis-σ,π-acetylide bridged complexes Cp2Ti(μ-η1:η2-CCSiMe3)M(μ-eta1:η2-CCSiMe3)Cp2 (M = Zr (4), M = Ti (5)) is formed in the reaction of zirconacyclocumulene 2 with three equivalents of Cp2Ti(η2-Me3SiCCSiMe3). The reaction proceeds most likely via alkyne elimination, a C-C-single bond activation, and the cleavage of the starting diyne takes place.
A Computationally Efficient Algorithm for Simultaneous Chemical and Phase Equilibrium Calculations
Authors: Tsvetkov Stefan , Stateva Roumiana P.
Published: July 2002

The paper recommends a particularly effective modification of the K-value approach to simultaneous phase and chemical equilibrium. Three examples are presented - the esterification reaction of ethanol with acetic acid, the synthesis of methanol, and the butylation of m-xylene. Discussed are the reliability and computational efficiency of the new algorithm.
Reaction of 4-Oxochromene-3-carboxaldehydes with Primary Amides and Benzotriazole or 1H-1,2,4-Triazole
Authors: Stankovičová Henrieta , Gašparová Renata , Lácová Margita , Chovancová Jarmila
Published: July 2002

N-[(6-substituted-4-oxochromen-3-yl)(1,2,4-triazol-3-yl)methyl]amides 5 and N-[(6-substituted-4-oxochromen-3-yl)(benzotriazol-1-yl)methyl]amides 6 were prepared by the reaction of 6-substituted 4-oxochromene-3-carboxaldehydes 1 with primary amides and 1H-1,2,4-triazole or 1H-benzotriazole. 6-Substituted 3-[hydroxy(1,2,4-triazol-1-yl)methyl]chromen-4-one 2 and 6-substituted 3-[hydroxy(benzotriazol-1-yl)methyl]chromen-4-one 3 were isolated as stable intermediates of these reactions. Beneficial effect of microwave irradiation on length of reaction time was observed. Some reactions of these derivatives with O, S, and N nucleophiles are described.
Ceramic Foam-Supported Perovskites as Catalysts for Combustion of Methane
Authors: Jirátová Květa , Morávková Lenka , Malecha Jiří , Koutský Bohumil
Published: July 2002

Methane combustion in the presence of various types of perovskites supported on ceramic foams has been studied with respect to the CO and NOx formation. The effect of the catalyst composition and of the air-to-methane ratio on the CO and NOx concentration has been evaluated for different burner capacities.
Human Orosomucoid: Dissociation of Tyrosines in the Systems Water-Low Aliphatic Alcohol
Authors: Karpenko Vladimír , Horálková Jana , Kodíček Milan
Published: July 2002

The influence of methanol, ethanol, propan-1-ol, and propan-2-ol on the dissociation of tyrosines of human serum orosomucoid (acid α1-glycoprotein) was studied. The content of alcohols was chosen so that their solutions had the same value of the relative permittivity. Then, the contribution of electrostatic effects was equal in all cases and the observed differences between aqueous and alcoholic solutions reflected other, nonelectrostatic effects in the studied systems. Analysis of the spectrophotometric titration curve revealed three kinds of tyrosine groups (n1, n2, n3), but only the values pK1 and pK2 could be calculated. The observed differences of pK values in aqueous and mixed media are discussed and compared with the structural changes of the orosomucoid molecule.
Unexpected Course of the Reaction of 1,3-Bis(dimethylamino)trimethinium Perchlorate with 3-Substituted Prop-2-ynals Leading to 1-Aryl-2,4,6-triformylbenzenes
Authors: Suchý Petr , Dvořák Dalimil , Havelková Martina
Published: July 2002

Reaction of 1,3-bis(dimethylamino)trimethinium perchlorate (1) with 3-substituted prop-2-ynals (4) in acetic anhydride at the presence of ZnBr2 gives upon hydrolysis 1-substituted 2,4,6-triformylbenzenes (6) in low to moderate yield. This reaction is restricted to prop-2-ynals bearing electron rich aromatic substituents at the 3-position.
Reactions of Furo[2,3-b]pyrrole and Furo[3,2-b]pyrrole-Type Aldehydes
Authors: Sleziak Róbert , Balážiová Slávka , Krutošíková Alžbeta
Published: July 2002

The synthesis of methyl 2-formyl-6-(methoxymethyl)furo[2,3-b]pyrrole-5-carboxylate (1d) is described. The reactions of methyl 2-formylfuro[2,3-b]pyrrole-5-carboxylates 1a-1d with malononitrile afforded methyl 2-(2,2-dicyanovinyl)furo[2,3-b]pyrrole-5-carboxylates 3a-3d, with methyl cyanoacetate methyl 2-[2-cyano-2-(methoxycarbonyl)vinyl]furo[2,3-b]pyrrole-5-carboxylates 4a-4d and with 2-furylacetonitrile methyl 2-[2-cyano-2-(2-furyl)vinyl]furo[2,3-b]pyrrole-5-carboxylates 5a-5d. Compounds 1b-1d and methyl azidoacetate gave the appropriate vinylazides 6b-6d, which were used for preparation of substituted furo[2,3-b:4,5-b']dipyrroles 7b-7d. Reactivity of furo[2,3-b]pyrrole aldehydes 1a-1d and furo[3,2-b]pyrrole aldehydes 2a-2c in their reactions with 5,5-dimethylcyclohexane-1,3-dione is compared. The prepared methyl 2-[bis(4,4-dimethyl-2,6-dioxocyclohexyl)methylfuro[2,3-b]pyrrole-5-carboxylates 8a-8d and their isomers 10a-10c cyclized into substituted octahydroxanthenes 9a-9d and 11a-11c, respectively. Methyl 4-benzyl-2- [(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)methyl]furo[3,2-b]pyrrole-5-carboxylate (12) was prepared using microwave irradiations.
Influence of Electrolyte Hydrodynamics on Current Yield in Ferrate(VI) Production by Anodic Iron Dissolution
Authors: Bouzek Karel , Schmidt Martin J. , Wragg Anthony A.
Published: July 2002

The dependence of current efficiency for ferrate(VI) synthesis on the superimposed electrolyte flow rate was determined using 14 M NaOH solution and a white cast iron electrode. The electrolyte mean velocity in the cell ranged from 0.4 to 2.9 cm s-1 and current density from 1.4 to 35.3 mA cm-2. It was found that current efficiency was influenced by electrolyte velocity only at current densities lower than 7 mA cm-2. This is explained in terms of the removal of intermediate products from the anode surface by the electrolyte convection. This factor becomes negligible at higher current densities in comparison to mass transfer induced by oxygen evolution on the anode surface.
Crystal Structures and Reactivity of 3a,5a,8a,10a-Tetraazaperhydropyrene Derivatives. An Alternative Approach to Selective Nitrogen Alkylation of 1,4,8,11-Tetraazacyclotetradecane (Cyclam)
Authors: Kotek Jan , Hermann Petr , Vojtíšek Pavel , Rohovec Jan , Lukeš Ivan
Published: July 2002

1-Alkyl and 1,8-dialkyl-1,4,8,11-tetraazacyclotetradecanes (alkyl = benzyl or methyl) were synthesised through cis-aminal of cyclam which was obtained by reaction of glyoxal and cyclam. The corresponding trans-aminal was synthesised from the respective linear tetraamine and glyoxal followed by cyclisation using 1,2-dibromoethane. The trans-aminal derivatives cannot be used for preparation of cyclam or its derivatives due to exceptional stability of the aminal bridge. The different reactivity of both cis- and trans-aminals is discussed on the basis of the X-ray structures determined for a series of the cyclam derivatives and could be explained by steric hindrance in the trans-aminals.
Substituent Effects on the Base-Catalysed Hydrolysis of Phenyl Esters of para-Substituted Benzoic Acids
Authors: Bauerová Ingrid , Ludwig Miroslav
Published: July 2002

Seventeen model phenyl esters of 4-substituted benzoic acids were synthesised by the reaction of substituted benzoyl chlorides with phenol in aqueous alkaline solutions (Schotten-Baumann reaction), in pyridine (Einhorn reaction), or by the reaction of substituted benzoic acids with phosphorus oxychloride. Structures and purity of the model compounds were confirmed by 1H NMR and 13C NMR spectroscopy as well as by HPLC and elemental analysis. Phenyl 4-aminobenzoate was synthesised by reduction of phenyl 4-nitrobenzoate in methanol on palladium. Kinetics of base-catalysed hydrolysis of model phenyl esters occurring by the BAc2 mechanism were measured by UV spectrophotometry in 50% (v/v) aqueous dimethyl sulfoxide solutions at 25 °C under pseudo-first-order conditions, (c[NaOH] = 0.001-1.0 mol l-1). The addition of OH- to phenyl benzoates was used to establish the kinetic J-E acidity scale. Linear relation between J-E and log kobs with the slope near unity was found for all the model compounds. The kinetic constants of hydrolysis of phenyl esters of 4-substituted benzoic acids precisely obey the Hammett relationship (σp) with ρ = 2.44. Quantitatively comparable results have been obtained by application of Alternative Interpretation of Substituent Effects theory (AISE) using the σi set of substituent constants.
Substituent Effects on the Base-Catalysed Hydrolysis of Phenyl Esters of ortho-Substituted Benzoic Acids
Authors: Bauerová Ingrid , Ludwig Miroslav
Published: July 2002

Fourteen model phenyl esters of 2-substituted benzoic acids were synthesised. Structures and purity of model compounds were confirmed by 1H and 13C NMR spectroscopy, as well as by HPLC and elemental analysis. Kinetics of base-catalysed hydrolysis of model phenyl esters occurring by the BAc2 mechanism were measured by UV spectrophotometry in 50% (v/v) aqueous dimethyl sulfoxide solutions at 25 °C under pseudo-first-order reaction conditions (c(NaOH) = 0.001-1.0 mol l-1). Linear relation between J-E and log kobs with the slope close to unity was found for all model compounds. Neither one-parameter nor multiparameter Hammett-type description of variability of experimental data obtained for phenyl esters of 2-substituted benzoic acids was found. Two groups (conjugating and non-conjugating) were created by division of ortho-substituents in ortho-position using the AISE theory, based on their interaction with the reaction centre.
Ultraviolet Absorption Spectra and Dissociation Constants of Diamino-1,3,5-triazines
Authors: Pérez Rafael , Marín Galvín Rafael , Rodríguez Mellado José M.
Published: July 2002

This paper presents ultraviolet absorption spectra of two diamino-1,3,5-triazines, namely 1,3,5-triazine-2,4-diamine (DT) and 6-chloro-1,3,5-triazine-2,4-diamine (ClDT). The spectra were fitted to the log-normal distribution. In the more energetic zone of the spectrum both compounds presented common bands, placed around 204-205 and 223-226 nm (depending on the pH of the medium). At higher wavelengths the spectra were different, with bands appearing in the range 235-267 nm. From variations of the maximum absorbances of the individual bands, the pKb values 3.5 ± 0.2 and 1.2 ± 0.1 were obtained for protonation of the ring nitrogen placed between the amine radicals of DT and ClDT, respectively, and 9.35 ± 0.2 and 11.5 ± 0.1 for dissociation of the amino groups of DT and ClDT, respectively.
Distal renal tubular acidosis with severe hypokalaemia, probably caused by colonic H+-K+-ATPase deficiency
Authors: Simpson A M , Schwartz G J
Published: July 2002

We describe a 21 month old male infant who presented with failure to thrive associated with severe hypokalaemia and metabolic acidosis, together with hypomagnesaemia. Evaluation revealed marked renal and probable faecal potassium wasting, distal renal tubular acidosis, mild urinary magnesium wasting, and a normal gastric pH (gastric H+-K+-ATPase). Hypokalaemic forms of metabolic acidosis, such as diabetic ketoacidosis and proximal renal tubular acidosis were ruled out from the clinical picture. The hypokalaemia of distal renal tubular acidosis usually improves with alkali therapy, but this was not observed: despite correction of acidosis with 5 mmol/kg potassium citrate per day, an additional 5 mmol/kg potassium chloride was required to bring serum potassium to 3.5 mmol/l. At 3 years of age potassium was provided in the absence of potential alkali and acidosis ensued; serum bicarbonate fell to 10 mmol/l. Although a specific genetic analysis is not yet possible, the abnormalities are consistent with a novel form of distal renal tubular acidosis. The pathophysiology probably does not stem from defects in the vacuolar H+-ATPase but more likely from deficient activity of the colonic isoform of H+-K+-ATPase that is resident in the medullary collecting duct and mediates potassium absorption and proton secretion.
99mTc-HMPAO leucocyte scintigraphy fails to detect Crohn's disease in the proximal gastrointestinal tract
Authors: Davison S M , Chapman S , Murphy M S
Published: July 2002

OBJECTIVE

To investigate the use of 99mTc-HMPAO (hexamethyl propylene amine oxime) leucocyte scintigraphy as a non-invasive screening test for inflammatory bowel disease.

PATIENTS

10 children with suspected Crohn's disease, in whom routine investigation using barium contrast radiology, upper gastrointestinal endoscopy, colonoscopy, and mucosal biopsies had identified severe gastroduodenal and/or jejunal involvement.

DESIGN

99mTc-HMPAO leucocyte scintigraphic studies performed in each of these cases were assessed by a radiologist who was blinded to the disease distribution.

RESULTS

In nine cases there was no scintigraphic evidence of inflammation in the proximal gastrointestinal tract. The 10th child had both gastroduodenal and jejunal involvement, but scintigraphy only revealed faint jejunal positivity.

CONCLUSIONS

99mTc-HMPAO leucocyte scintigraphy should not be depended upon as a screening test for Crohn's disease. False negative results are likely in cases with Crohn's disease confined to the proximal gastrointestinal tract.
Neutrophil function response to aerobic and anaerobic exercise in female judoka and untrained subjects
Authors: Wolach Baruch , Falk Bareket , Gavrieli Ronit , Kodesh Einat , Eliakim Alon
Published: July 2002

Objectives—Recent studies have indicated reduced immunity in trained athletes.

Aim—To assess the effects of aerobic and anaerobic exercise on the phagocytic process in 18–26 year old trained female judoka (n = 8) and untrained controls (n = 7).

Methods—Each subject participated randomly in two different testing sessions (aerobic, 20 minutes of treadmill running at 70–80% of maximal heart rate; anaerobic, Wingate anaerobic test). Venous blood samples were drawn before, immediately after, and 24 hours after each session.

Results—There were no significant differences in basal values of net chemotaxis (chemotaxis − random migration), bactericidal activity, and superoxide anion release between the judoka and the untrained women. There was a significant decrease in net chemotaxis 24 hours after the aerobic exercise in both the judoka (from 64 (19) to 39 (13) cells/field, p<0.02) and the untrained controls (from 60 (7) to 47 (12) cells/field, p<0.05). Bactericidal activity and superoxide anion release did not change significantly after aerobic exercise in either group. There were no significant changes in net chemotaxis, bactericidal activity, and superoxide anion release after anaerobic exercise in either the judoka or untrained women.

Conclusions—The decrease in net chemotaxis after aerobic, but not after anaerobic, exercise, suggests that net chemotaxis is affected by the combination of exercise intensity and duration, and not by the exercise intensity itself. Similar effects of both exercise sessions in the judoka and the untrained women suggest that training had no effect on neutrophil function response to aerobic and anaerobic exercises.
Recurrent haematomas of the thigh: a case of von Willebrand's disease presenting to a sports clinic: Figure 1
Authors: Owens Simon , Baglin Trevor
Published: July 2002

Von Willebrand's disease is a relatively common mild form of haemophilia. It should be suspected in assessing sports injuries when excessive bleeding occurs in response to relatively mild trauma. Those with the disease should remain active but avoid contact sports. They should not take aspirin or non-steroidal anti-inflammatory drugs, which may exacerbate bleeding, and should be given supportive treatment to cover dental extraction, surgery, or significant bleeding episodes.
Acute injury incidence in professional county club cricket players (1985–1995): Figure 1
Authors: Leary Tim , White John A
Published: July 2002

Background—There is a dearth of evidenced based research into sports injury in professional cricket.

Aim—To investigate the incidence, nature, and site of acute injuries sustained by professional cricketers at one English county club over the period 1985–1995.

Methods—Injuries in a sample of 54 cricketers who had played in the first team for the same county cricket club in any or all seasons between 1985 and 1995 were investigated. Injury was defined as the onset of pain or a disability resulting from either training for or playing cricket, which caused the player to seek medical attention.

Results—An acute injury rate of 57.4 injuries per 1000 days of cricket played was found, with most injuries sustained during April, the month in which the least number of days were played. The lower limb was the region most vulnerable to injury, accounting for 44.9% of all injuries, followed by the upper limb (29.4%), the trunk (20.0%), and the head and neck (5.7%). No significant difference in injury incidence among player positions was found.

Conclusion—There is a need for a system of epidemiological data collection and development of a national cricket injury database to help predict, reduce, and prevent injury at all levels of the game.
A survey of the causes of sudden death in sport in the Republic of Ireland
Authors: Quigley Fionnuala
Published: July 2002

Background—Sudden death in sport is rare, but when it occurs the effects are devastating. There have not been any reports to date describing the frequency and causes of sudden death in sport in the Republic of Ireland.

Aim—To describe the incidence, possible causes, associated factors, and pathological findings in people who died while exercising in the Republic of Ireland in the 10 year period from January 1987 to December 1996.

Methods—All 49 regional coroners in the Republic of Ireland were approached and details on all cases of sudden death in sport from 1 January 1987 to 31 December 1996 were requested. A questionnaire was used to document age, sex, participating sport, previous symptoms, previous medical investigations, circumstances of death, and main pathological finding in all reported cases.

Results—Of the 49 coroners surveyed, 45 replied. A total of 51 cases of sudden death in sport were identified. The median age was 48 (range 15–78). Fifty of the deaths were of men. Golf was the most popular participating sport. In 42 cases, the pathological cause of death was atherosclerotic coronary artery disease.

Conclusions—This is the first time the incidence of sudden death in sport in the Republic of Ireland has been described. The main cause of death in all age groups was atherosclerotic coronary artery disease.
Factor XIIa and triacylglycerol rich lipoproteins: responses to exercise intervention
Authors: Woolf-May K , Jones W , Kearney E M , Davison R C R , Bird S
Published: July 2002

Objectives—(a) To determine if factor XIIa (FXIIa) would be sensitive to change from exercise intervention in a group of previously sedentary/low active middle aged men and women; (b) to investigate further the previously reported relation between FXIIa and triacylglycerol (TAG) rich lipoproteins.

Methods—Thirty seven men (mean (SD) age 57 (7) years) and 60 women (mean age 54 (7) years) completed the study. Before the intervention, these subjects were randomly allocated to a group of walkers (n = 81) or controls (n = 16). Before and after an 18 week walking intervention, fasted blood samples were collected and analysed for FXIIa, TAG, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and apolipoprotein (apo) B.

Results—Kruskal-Wallis analysis of data obtained before the intervention showed no significant differences (p>0.4) between the walking and control groups for age, height, body mass, gender, FXIIa, TAG, TC, HDL-C, or apo B, although the women did show significantly lower levels of TAG (p<0.04) and higher HDL-C (p<0.0001) than the men. General linear model analysis of data obtained after the intervention, using the baseline value as a covariate, showed significant reductions (p<0.0001) in FXIIa for the walkers compared with the controls. Pearson product-moment correlations also showed significant relations between the concentrations of FXIIa and TAG, TC, LDL-C, and apo B.

Conclusions—The findings of this study suggest that FXIIa is sensitive to change from exercise intervention and support previous research showing an association between the concentrations of FXIIa and TAG rich lipoproteins.
Simultaneous Bennett's fracture and metacarpophalangeal dislocation of the same thumb in a soccer player
Authors: Jari S , Waseem M , Srinivasan M S
Published: July 2002

Double dislocations of finger joints are rare. An unusual case of a simultaneous Bennett's fracture/dislocation of the carpometacarpal joint and a dorsal dislocation of the metacarpophalangeal joint of the same thumb, and the management of this injury are reported. The patient had an excellent functional result.
Influence of rugby injuries on players' subsequent health and lifestyle: beginning a long term follow up
Authors: Lee A J , Garraway W M , Hepburn W , Laidlaw R
Published: July 2002

Objectives—To describe the current rugby playing status of a cohort of 1169 men who had previously participated in an epidemiological survey of rugby injuries during the 1993–1994 season, and assess the consequences of rugby injuries sustained.

Methods—In May 1998, 911 (78%) men completed a questionnaire reporting their current involvement in rugby and the influence that the 324 (71%) injuries they had sustained four years earlier had since had on their health and wellbeing.

Results—The most common reasons given by the 390 (43%) ex-players for ceasing to play rugby were family (10%), employment (25%), and an injury sustained while playing rugby (26%), 80% of which were dislocations, strains, and sprains, mainly to the knee (35%), back (14%), and shoulder (9%). A significantly (χ2test 21.7, df = 1, p<0.001) higher proportion of current players (90%) undertook (non-rugby) sporting activities compared with ex-players (78%). Few ex-players undertook coaching (12%) and refereeing (2%). Only 22 (9%) men reported significant negative effects to employment, family life, and health up to mid-1998 from injuries that occurred during the 1993–1994 season, although the impact on their lifestyle had been substantial in some cases.

Conclusions—With the recent increase in the incidence of dislocation, strain, and sprain injuries in rugby football, the findings of this follow up could have a great impact on the game in the future. Although this survey has shown that, so far, only a small proportion of players suffer significant effects of rugby injuries, four years is not long enough to assess the long term effects. This cohort of rugby players need to be followed up for at least a further 20 years to determine whether there is a higher incidence of subsequent degenerative joint disease or other long term sequelae to injuries sustained while playing rugby.
Sports doctors' resuscitation skills under examination: do they take it seriously?
Authors: Lavis M , Rose J , Jenkinson T
Published: July 2002

As 64% of sports medicine doctors were unable to show proficiency at basic life support and assessment and management of a seriously injured patient with a potential spinal injury in the last two examinations for a University of Bath diploma in sports and exercise medicine, it was decided that a reminder is required of the importance of acquiring, at the very least, some basic resuscitation skills. An analysis and comment on the results from the first aid component of the examination is also presented.
A profile of patients attending sports medicine clinics
Authors: Finch C F , Kenihan M A R
Published: July 2002

Objectives—To describe the sociodemographic profile of sports injury patients who attend sports medicine clinics for treatment and to describe their reasons for choosing to attend such clinics.

Method—Data were collected as part of a fully audited injury surveillance system implemented within sports medicine clinics. The study was conducted within five allied multidisciplinary sports medicine clinics in metropolitan Melbourne, Australia. All patients initially presenting for treatment of a new sports or active recreation injury over the period August 1997 to August 1998 were eligible for this study, irrespective of the practitioner providing the treatment. Data were obtained on 6476 patients.

Results—The median age of the patients was 25.4 years (range 6.8–81.6) and most were male (69.8% of cases; 95% confidence interval (95% CI) 68.7 to 70.9). Patients had both professional and non-professional backgrounds and were not just local suburb residents. Many patients had insurance cover for their injury treatment: 59.0% (95% CI 58.6 to 59.4) had some private health insurance and 46.6% (95% CI 45.4 to 47.8) had club/association insurance. The most common reasons for attending a clinic was its location (36.8%; 95% CI 36.5 to 37.1) and referral/recommendation (31.0%; 95% CI 30.7 to 31.3).

Conclusion—Sports medicine clinics provide treatment for a broad spectrum of injured sports participants across a variety of sporting/recreation contexts. Although these clinics mainly serve the immediate geographic community, the sports speciality and expertise of a particular clinic can attract patients from further afield. This information can help sports medicine clinics to market their services more efficiently to meet the needs of their potential patients.
Apolipoprotein H, a new mediator in the inflammatory changes ensuing in jeopardised human myocardium
Authors: Niessen H W M , Lagrand W K , Rensink H J A M , Meijer Ch J L M , Aarden L , Hack C E
Published: July 2002

Aim—To investigate the presence of membrane “flip flop” in ischaemic human myocardium, we assessed depositions of apolipoprotein H (apoH; β2-glycoprotein 1) in ischaemic myocardium. Serum protein apoH can bind to negatively charged phospholipids and can also inhibit blood coagulation in vitro. We hypothesised that, because of its affinity for phosphatidyl serine, apoH might bind to “flip flopped” cells and would therefore be useful as a marker for membrane flip flop in vivo.

Methods—Myocardial tissue specimens were obtained from patients who had died within 14 days of acute myocardial infarction.

Results—Immunohistochemical analysis of these specimens revealed that apoH was selectively deposited in infarcted areas of human myocardium of at least one day's duration. Depositions of apoH were not found in non-ischaemic myocardial tissue samples obtained from patients who died from other (extracardial) causes. In vitro experiments with the human leukaemia T cell line Jurkat, subjected to apoptosis by etoposide, showed that apoH was bound to the membrane of apoptotic cells. However, these experiments also indicated that flip flop itself is not sufficient for apoH binding. In addition, Jurkat cells that bound apoH were positive for activated complement complexes, as was also found in the human heart.

Conclusions—These results suggest that apoH is involved in the inflammatory processes that occur in ischaemic myocardium.
Phenotypic change of muscularis mucosae in early invasive colorectal adenocarcinoma
Authors: Ban S , Kamada K , Mitsuki N , Goto Y , Shimizu Y , Takahama M , Shibata T
Published: July 2002

Background—Invasive colorectal adenocarcinomas have bundles of eosinophilic spindle cells, which are regarded as myofibroblasts, in their desmoplastic stroma, some of which are continuous with the muscularis mucosa.

Aim—To investigate the relation between the eosinophilic spindle cells and the muscularis mucosa based on their cytoskeletal phenotypes in early invasive colorectal adenocarcinoma.

Methods—Formalin fixed, paraffin wax embedded tissues of 17 early invasive colorectal adenocarcinomas were immunostained for α-smooth muscle actin (α-SMA), desmin, and vimentin.

Results—The phenotype of the muscularis mucosa was α-SMA positive, desmin positive, and vimentin weakly positive, whereas the eosinophilic spindle cells showed a decreased degree of immunoreactivity for α-SMA and desmin in particular, and an increased degree of immunoreactivity for vimentin. The degree of phenotypic difference between the muscularis mucosa and the eosinophilic spindle cells was greater in the eosinophilic spindle cells in the centre of the invasive area that were not continuous with the muscularis mucosa than in the eosinophilic spindle cells continuous with the muscularis mucosa.

Conclusions—These findings suggest that the smooth muscle cells of the muscularis mucosa change their phenotype to become eosinophilic spindle cells, namely myofibroblasts, in the early invasive area of colorectal adenocarcinoma.
Parental consent to cosmetic facial surgery in Down's syndrome
Authors: Jones R B
Published: July 2002

It is suggested that the practice of attempting to normalise children with Down's syndrome by subjecting them to major facial plastic surgery has no therapeutic benefit, and should be seen as mutilating surgery comparable to female circumcision.
Can unequal be more fair? A response to Andrew Avins
Authors: Edwards Sarah J L , Braunholtz David A
Published: July 2002

In this paper, we respond to Andrew Avins's recent review of methods whose use he advocates in clinical trials, to make them more ethical. He recommends in particular, “unbalanced randomisation”. However, we argue that, before such a recommendation can be made, it is important to establish why unequal randomisation might offer ethical advantages over equal randomisation, other things being equal. It is important to make a pragmatic distinction between trials of treatments that are already routinely available and trials of restricted treatments. We conclude that unequal randomisation could, indeed, be an ethical compromise between protecting the interests of participants and those of society.
Randomisation and resource allocation: a missed opportunity for evaluating health care and social interventions: Figure 1:
Authors: Toroyan Tami , Roberts Ian , Oakley Ann
Published: July 2002

Equipoise is widely regarded to be an essential prerequisite for the ethical conduct of a randomised controlled trial. There are some circumstances however, under which it is acceptable to conduct a randomised controlled trial (RCT) in the absence of equipoise. Limited access to the preferred intervention is one such circumstance. In this paper we present an example of a randomised trial in which access to the preferred intervention, preschool education, was severely limited by resource constraints. The ethical issues that arise when conducting randomised trials in health care are considered in the context of trials of social interventions. In health, education and social welfare, effective interventions are frequently limited due to budgetary constraints. Explicit acknowledgement of the need to ration interventions, and the use of random allocation to do this even in the absence of equipoise, would facilitate learning more about the effects of these interventions.
A ‘fair innings’ for efficiency in health services?
Authors: Bosanquet Nick
Published: July 2002

This paper reviews the severe visual focus problems of health economists–they have developed a one-sided fixation with equity issues, neglecting the efficiency agenda. The problems of meeting need are not just about access–they will vary with cost and supply. Economists in fact developed a more balanced agenda in the 1970s but have failed to follow it up. The paper defines the triple nationalisation of the National Health Service (NHS), and presents evidence that pluralism, using the purchaser/provider split, has become more efficient in long term care, home care and services for people with learning difficulties. Health economics has failed to explore options for using the dynamic forces of choice and competition for improving health services. The paper makes the case for a decision rule that “we should seek the process of health care service supply and development which maximises the delivery of high quality, lower cost user relevant services”.
Supererogation and altruism: a comment
Authors: Downie R S
Published: July 2002

Supererogation can be distinguished from altruism, in that the former is located in the category of duty but exceeds the strict requirements of duty, whereas altruism belongs to a different moral category from duty. It follows that doctors do not act altruistically in their professional roles. Individual doctors may sometimes show supererogation, but supererogation is not a necessary feature of the medical profession. The aim of medicine is to act in the best interests of patients. This aim involves neither supererogation nor even the moral quality of beneficence. It is simply a job description. Morality enters medicine through the quality of the individual doctor's work, not by the definition of that work.
Nested case-control study of lung cancer in four Chinese tin mines
Authors: Chen W , Chen J
Published: July 2002

Objectives: To evaluate the relation between occupational dust exposure and lung cancer in tin mines. This is an update of a previous study of miners with high exposure to dust at four tin mines in southern China.

Methods: A nested case-control study of 130 male lung cancer cases and 627 controls was initiated from a cohort study of 7855 subjects employed at least 1 year between 1972 and 1974 in four tin mines in China. Three of the tin mines were in Dachang and one was in Limu. Cumulative total exposure to dust and cumulative exposure to arsenic were calculated for each person based on industrial hygiene records. Measurements of arsenic, polycyclic aromatic hydrocarbons (PAHs), and radon in the work sites were also evaluated. Odds ratios (ORs), standard statistic analysis and logistic regression were used for analyses.

Results: Increased risk of lung cancer was related to cumulative exposure to dust, duration of exposure, cumulative exposure to arsenic, and tobacco smoking. The risk ratios for low, medium, and high cumulative exposure to dust were 2.1 (95% confidence interval (95% CI) 1.1 to 3.8), 1.7 (95% CI 0.9 to 3.1), and 2.8 (95% CI 1.6 to 5.0) respectively after adjustment for smoking. The risk for lung cancer among workers with short, medium, and long exposure to dust were 1.9 (95% CI 1.0 to 3.5), 2.3 (95% CI 1.3 to 4.1), and 2.3 (95% CI 1.2 to 4.2) respectively after adjusting for smoking. Several sets of risk factors for lung cancer were compared, and the best predictive model included tobacco smoking (OR=1.6, 95% CI 1.1 to 2.4) and cumulative exposure to arsenic (ORs for different groups from low to high exposure were 2.1 (95% CI 1.1 to 3.9); 2.1 (95% CI 1.1 to 3.9); 1.8 (95% CI 1.0 to 3.6); and 3.6 (95% CI 1.8 5 to 7.3)). No excess of lung cancer was found among silicotic subjects in the Limu tin mine although there was a high prevelance of silicosis. Exposures to radon were low in the four tin mines and no carcinogenic PAHs were detected.

Conclusions: These findings provide little support for the hypothesis that respirable crystalline silica induces lung cancer. Ore dust in work sites acts as a carrier, the exposure to arsenic and tobacco smoking play a more important part in carcinogenesis of lung cancer in tin miners. Silicosis seems not to be related to the increased risk of lung cancer.
Effects of maternal exposure to cadmium on pregnancy outcome and breast milk
Authors: Nishijo M , Nakagawa H , Honda R , Tanebe K , Saito S , Teranishi H , Tawara K
Published: July 2002

Objective:The effects of cadmium (Cd) on birth weight have been discussed in the scientific literature. However, investigations on the effects of maternal body burden of Cd on the next generation during pregnancy and lactation have been limited. The relation between maternal exposure to Cd and pregnancy outcome or Cd in breast milk in Japanese mothers was investigated.

Methods:Cd concentrations in urine and colostrum milk samples of 57 mothers were measured by atomic absorption spectrophotometery. The relations between maternal urinary Cd and infant growth, gestational age at birth, and Cd in breast milk were investigated.

Results:The rate of perterm deliveries of mothers with higher urinary Cd (≥2 nmol/mmol creatinine (Cr)) was higher than that of mothers with lower urinary Cd (<2 nmol/mmol Cr). The gestational age was significantly correlated with urinary Cd even after adjustment for maternal age. The height and weight of newborn infants of mothers with higher urinary Cd were significantly lower than those of the newborn infants of mothers with lower urinary Cd, but these decreases were ascribed to early delivery induced by Cd. The Cd in breast milk of mothers with higher urinary Cd was significantly higher than that of mothers with lower urinary Cd. A significant positive correlation was found between maternal urinary Cd and Cd in breast milk.

Conclusion:Maternal exposure to Cd seems to increase early delivery, which leads to a lower birth weight. Also, the Cd is transferred in part to the next generation through breast milk after birth.