bluuebunny/crossref_metadata_2025_split huggingface dataset:
Randomized clinical trial assessing the side-effects of glyceryl trinitrate and diltiazem hydrochloride in the treatment of chronic anal fissure
Authors: Kocher H M , Steward M , Leather A J M , Cullen P T 
Published: March 2003

Abstract

Introduction
Glyceryl trinitrate (GTN) ointment (0·2 per cent) has an efficacy of up to 68 per cent in healing chronic anal fissure, but with headache as a major side-effect. Diltiazem hydrochloride (DTZ) cream (2 per cent) is expected to have fewer side-effects.

Methods
A prospective double-blind randomized two-centre trial requiring at least 26 patients in each group (α = 0·05, β = 0·9) was instituted after approval of the local ethics committee, to compare the incidence of side-effects (primary endpoint) with 0·2 per cent GTN ointment and 2 per cent DTZ cream in the treatment of chronic anal fissure. Treatments were applied perianally, twice daily for 6–8 weeks. All patients gave written informed consent.

Results
Both groups were comparable in patient demographics and clinical characteristics. Twelve patients violated the protocol, withdrew or did not attend follow-up. There were more side-effects with GTN (21 of 29 patients) than with DTZ (13 of 31) (relative risk (RR) 1·84 (95 per cent confidence interval (c.i.) 1·11 to 3·04), P = 0·01). In particular, more headaches occurred with GTN (17 of 29 patients) than with DTZ (eight of 31) (RR 2·06 (95 per cent c.i. 1·18 to 3·59), P = 0·01). There were no significant differences in healing and symptomatic improvement rates between patients receiving GTN (25 of 29) and DTZ (24 of 31).

Discussion
DTZ cream caused substantially fewer headaches than GTN ointment. There was no significant difference in the healing or improvement of chronic anal fissure between the treatments. DTZ may be the preferred first-line treatment for chronic anal fissure.
Risk of femoral hernia after inguinal herniorrhaphy
Authors: Mikkelsen T , Bay-Nielsen M , Kehlet H 
Published: March 2003

Abstract

Background
Small case series have suggested an increased risk of femoral hernia after previous inguinal herniorrhaphy, but no large-scale data with complete follow-up are available.

Methods
Data were extracted from the Danish Hernia Database covering the interval from 1 January 1998 to 1 July 2001, and included 34 849 groin hernia repairs.

Results
Of 1297 femoral hernia repairs, 71 patients had previously had an operation for inguinal hernia within the observation period. These 71 femoral hernias represented 7·9 per cent of all reoperations for groin hernia recorded in the database. The median time to reoperation for a ‘recurrent’ femoral hernia after previous inguinal herniorrhaphy was 7 months, compared with 10 months for inguinal recurrences. The risk of developing a ‘recurrent’ femoral hernia after previous inguinal herniorrhaphy was 15 times higher than the rate of femoral hernia repair in the general population.

Conclusion
This study of 34 849 groin hernia repairs demonstrated a 15-fold greater incidence of femoral hernia after inguinal herniorrhaphy compared with the spontaneous incidence. These femoral recurrences occurred earlier than inguinal recurrences, suggesting that they were possibly femoral hernias overlooked at the primary operation.
Cloning, expression, purification and characterization of patatin, a novel phospholipase A
Authors: Hirschberg Hoang J. H. B. , Simons Jan‐Willem. F. A. , Dekker Niek , Egmond Maarten R. 
Published: March 2003

Patatin is the major protein constituent of potato tubers and displays broad esterase activity. The native enzyme actually belongs to a highly homologous multigene family of vacuolar glycoproteins. From these, the patB2 patatin gene was selected and cloned into pUC19 without its signal sequence but with an N‐terminal histidine‐tag. This patatin was overexpressed under the control of the lac promotor in Escherichia coli strain DH5α. The protein was recovered as inclusion bodies, folded into its native state by solubilization in urea and purified to homogeneity. Starting with one gram of inclusion bodies, 19 mg of pure and active recombinant patatin was isolated, with even higher specific activity than the glycosylated wild‐type patatin purified from potato tubers. The purified enzyme showed esterolytic activity with p‐nitrophenylesters dissolved in Triton X‐100 micelles. The activity of patatin on p‐nitrophenylesters with different carbon chain lengths showed an optimum for p‐nitrophenylesters with 10 carbon atoms. Besides general esterolytic activity, the pure enzyme was found to display high phospholipase A activity in particular with the substrates 1,2‐dioctanoyl‐sn‐glycero‐3‐phosphocholine (diC8PCho) (127 U·mg−1) and 1,2‐dinonanoyl‐sn‐glycero‐3‐phosphocholine (diC9PCho) (109 U·mg−1).Recently, the structure of human cytosolic PLA2 (cPLA2) was solved, showing a novel Ser‐Asp active site dyad [1]. Based on a partial sequence alignment of patatin with human cPLA2, we propose that patatin contains a similar active site dyad. To verify this assumption, conserved Ser, Asp and His residues in the family of patatins have been modified in patatin B2. Identification of active site residues was based on the observation of correctly folded but inactive variants. This led to the assignment of Ser54 and Asp192 as the active site serine and aspartate residues in patatin B2, respectively.
An extrusion strategy for the FeMo cofactor from nitrogenase.
Authors: Martin Lisandra L. , West Lee C. , Wu Bei 
Published: March 2003

Iron–sulfur clusters are ubiquitous in biological systems, facilitating functions such as electron transfer (rubredoxins, ferredoxins, rieske centres), isomerization (aconitase) and small molecule activation such as dinitrogen reduction (nitrogenases). Of global importance and recently particular interest, is the iron–sulfur‐containing iron‐molybdenum cofactor (FeMoco) cluster that achieves the biological reduction of dinitrogen under mild conditions. This biologically unique cluster has proved difficult to investigate due to its extreme air sensitivity and the instability of the cluster's structural integrity, outside the protective protein matrix.Here, we report a model iron–sulfur cluster (Roussins black salt (NH4)[Fe4S3(NO)7]) that has been used to achieve the first example of a metal cluster (guest) embedded within a pseudo‐protein, cyclodextrin (host). The product formed is supramolecular, that is, it contained no covalent bonds and was stabilized by predominantly entropy effects. Formation of a 1 : 1 complex between the host and the guest was established for the iron–sulfur cluster with either seven‐ or eight‐membered cyclodextrins (β‐ or γ‐cyclodextrin). A range of techniques was used to characterize the new complexes in both the solid and solution states. Electrospray mass spectra indicated the presence of parent ions of the host–guest complexes and electrochemistry was also used to define the redox behavior of the complexes. The iron–sulfur clusters were significantly more stable in the presence of the host cyclodextrin, as revealed by a negative shift for the reduction potential for the host–guest product. Using the β‐cyclodextrin as host, the reduction potential of the iron–sulfur cluster shifted more negative by 60 mV; the effect was even more dramatic for the larger γ‐cyclodextrin where the reduction potential for the cluster was shifted by 90 mV more negative than the ‘unbound’[Fe4S3(NO)7]– cluster.This is the first example of a metal cluster, stabilized as a supramolecular complex in a ‘host’ environment outside of a covalently bonded protein matrix. Creating such stable environments for metal cofactors or clusters that otherwise spontaneously degrade or are catalytically inactive outside the protein matrix could have enormous practical value. Specific implications for the development of extrusion methods for FeMoco from nitrogenase are enormous, with previously difficult, high‐energy molecular transformations, such as dinitrogen to ammonia, now more realistically accessible.
Cytochrome c/cytochrome c oxidase interaction
Authors: Sampson Valerie , Alleyne Trevor 
Published: March 2003

We investigated the interaction between cytochrome c oxidase and its substrate cytochrome c by catalyzing the covalent linkage of the two proteins to yield 1 : 1 covalent enzyme–substrate complexes under conditions of low ionic strength. In addition to the ‘traditional’ oxidized complex formed between oxidized cytochrome c and the oxidized enzyme we prepared complexes under steady‐state reducing conditions. Whereas for the ‘oxidized’ complex cytochrome c became bound exclusively to subunit II of the enzyme, for the ‘steady‐state’ complex cytochrome c became bound to subunit II and two low molecular mass subunits, most likely VIb and IV.For both complexes we investigated: (a) the ability of the covalently bound cytochrome c to relay electrons into the enzyme, and (b) the ability of the covalently bound enzyme to catalyze the oxidation of unbound (exogenous) ferrocytochrome c. Steady‐state spectral analysis (400–630 nm) combined with stopped‐flow studies, confirmed that the bound cytochrome c mediated the efficient transfer of electrons from the reducing agent ascorbate to the enzyme. In the case of the latter, the half life for the ascorbate reduction of the bound cytochrome c and that for the subsequent transfer of electrons to haem a were both < 5 ms. In contrast the covalent complexes, when reduced, were found to be totally unreactive towards oxidized cytochrome c oxidase confirming that the previously observed reduction of haem a within the complexes occurred via intramolecular rather than intermolecular electron transfer.Additionally, stopped‐flow analysis at 550 nm showed that haem a within both covalent complexes catalyzed the oxidation of exogenous ferrocytochrome c: The second order rate constant for the traditional complex was 0.55×106 m−1·s−1 while that for the steady‐state was 0.27×106 m−1·s−1. These values were approximately 25–50% of those observed for 1 : 1 electrostatic complexes of similar concentrations. These results combined with those of the ascorbate and the electrophoresis studies suggest that electrons are able to enter cytochrome c oxidase via two independent pathways. We propose that during enzyme turnover the enzyme cycles between two conformers, one with a substrate binding site at subunit II and the other along the interface of subunits II, IV and VIb. Structural analysis suggests that Glu112, Glu113, Glu114 and Asp125 of subunit IV and Glu40, Glu54, Glu78, Asp35, Asp49, Asp73 and Asp74 of subunit VIb are residues that might possibly be involved.
Transient contribution of mast cells to pulmonary eosinophilia but not to hyper‐responsiveness
Authors: Ogawa K. , Kaminuma O. , Kikkawa H. , Nakata A. , Asahina M. , Egan R. W. , Akiyama K. , Mori A. 
Published: March 2003

Background We have recently demonstrated that the transfer of interleukin (IL)‐5‐producing CD4+ T cell clones into unprimed mice is sufficient for the development of eosinophilic inflammation in the bronchial mucosa upon antigen inhalation.Objective The aim of this study was to elucidate the possible contribution of mast cells in eosinophilic inflammation and bronchial hyper‐responsiveness (BHR), and to discriminate between the roles of CD4+ T cells and mast cells.Methods Mast cell‐deficient mice (WBB6F1‐W/Wv) and their congenic normal littermates (WBB6F1−+/+) were immunized with ovalbumin and challenged by inhalation with the relevant antigen.Results Airway eosinophilia was induced with equivalent intensity in +/+ and W/Wv mice 6, 24, 96 and 216 h after antigen inhalation. In contrast, 48 h after antigen challenge, eosinophilic infiltration into the bronchial mucosa was significantly less pronounced in W/Wv mice than in +/+ mice. Anti‐CD4 monoclonal antibody (mAb), anti‐IL‐5 mAb, and cyclosporin A were administered next, demonstrating that the airway eosinophilia of W/Wv mice induced 48 h after antigen challenge was almost completely inhibited by each of these three treatments, but that of +/+ mice was significantly less susceptible. Bronchial responsiveness to acetylcholine was increased 48 h after antigen challenge and was not significantly different between +/+ and W/Wv mice. Administration of anti‐IL‐5 mAb completely inhibited the development of BHR in both +/+ and W/Wv mice.Conclusion These results indicate that, in mice, mast cells do have a supplemental role in the development of pulmonary eosinophilia but not BHR. CD4+ T cells totally regulate these responses by producing IL‐5.
cDNA cloning and heterologous expression of the major allergens from peach and apple belonging to the lipid‐transfer protein family
Authors: Diaz‐Perales A. , Garcia‐Casado G. , Sanchez‐Monge R. , Garcia‐Selles F. J. , Barber D. , Salcedo G. 
Published: March 2003

Background Lipid‐transfer proteins (LTPs) have been identified as major allergens of Rosaceae fruits in populations living in areas virtually free of Fagales trees, such as several Mediterranean communities. Pru p 3 and Mal d 3, the allergens from peach and apple, respectively, have a main clinical relevance in these areas.Objetive To isolate and characterize cDNAs for Pru p 3 and Mal d 3,and to produce recombinant Pru p 3 in the yeast Pichia pastoris.Methods cDNAs for both allergens were isolated by polymerase chain reaction using non‐degenerated primers. Expression of Pru p 3 was performed in P. pastoris using the pPIC 9 vector. The recombinant product was purified by gel‐filtration chromatography followed by RP‐HPLC. Immunodetection and immunoblot inhibition assays were carried out with sera from peach‐allergic patients.Results The cDNAs for both Pru p 3 and Mal d 3 showed a 273 open reading frame coding for the 91 amino acid mature polypeptides. The deduced amino acid sequences exhibited N‐terminal regions fully identical to those previously determined for the natural peach and apple allergens. Pru p 3 was expressed in P. pastoris at 20 mg/L of culture medium. The recombinant allergen showed the same N‐terminal sequence (plus a glutamic acid added for proper extracellular expression) and apparent molecular size as natural Pru p 3. Both the recombinant and natural forms of Pru p 3 displayed similar immunoglobulin (Ig)E‐binding capacity in immunodetection and immunoblot inhibition assays.Conclusions Comparison of the complete primary structures of mature Pru p 3 and Mal d 3 deduced from their corresponding cDNA clones supports the close relationship between both allergens. Recombinant Pru p 3 binds IgE in vitro like its natural counterpart. Therefore, it can be a useful tool for specific diagnosis and structural studies.
Basal metabolic rate in migratory waders: intra‐individual, intraspecific, interspecific and seasonal variation
Authors: Kvist A. , Lindström Å. 
Published: March 2003

Summary

Basal metabolic rates (BMR) were measured in 36 adult and 119 juvenile waders of 19 species on autumn migration in southern Sweden.
In a comparison with literature data, it was found that juvenile BMR was generally lower than at the onset of migration in the Arctic and slightly higher than on African wintering grounds.
The seasonal differences may reflect local physiological adaptations or possibly a gradual decline from high premigratory levels due to growth. Our data contradict the idea that BMR is high during migration as an adaptation to generally high levels of energy expenditure.
The allometric exponent, scaling BMR to body mass, was significantly higher within individuals (1·19) and within species (1·82) than among species (0·62).
The high intra‐individual exponent indicates that non‐fat tissues, with a high metabolic activity, are involved in the mass changes during migratory stopover.
The high intraspecific exponent indicates that tissues with a high metabolic activity contributed disproportionately to variation in body mass among individuals or that larger individuals had elevated mass specific metabolic rates of some tissues.
Dehydration tolerance and water vapour absorption in two species of soil‐dwelling Collembola by accumulation of sugars and polyols
Authors: Holmstrup M. , Sjursen H. , Ravn H. , Bayley M. 
Published: March 2003

Summary Physiological and biochemical responses to desiccation were studied in two species of hygrophilic Collembola,Folsomia fimetariaL. andProtaphorura armataTullberg. The temporal changes in water content, body fluid osmotic pressure, and accumulation of sugars and polyols during desiccation stress, equivalent to severe soil drought are reported. Both species initially lost about 50% of their initial content of osmotically active water. Within 7 daysF. fimetariahad re‐established their preliminary water content by absorbing water vapour from the atmosphere.Protaphorura armataalso significantly increased their water content over the following 10 days. Both species were able to resume their hyperosmotic status relative to the desiccating environment they were placed in. The accumulation of myo‐inositol and two other unidentified compounds (F. fimetaria) and trehalose (P. armata) made an important contribution to this phenomenon. These results suggest that water vapour absorption by accumulation of sugars and polyols may be widespread in soil‐dwelling Collembola.
Density‐dependent foraging effort of Deer Mice (Peromyscus maniculatus)
Authors: Davidson D. L. , Morris D. W. 
Published: March 2003

Summary Little is known about how population density affects the foraging behaviour of individuals. Simple models are developed to predict the net effect of density on the quitting‐harvest rates of optimal foragers. The theory was tested with experiments that measured the foraging behaviour of free‐ranging Deer Mice under control and reduced densities. An increased density of conspecifics may (a) reduce the costs of foraging by increasing competition for resources (reduces the energetic state of the forager; competition hypothesis) or (b) increase the costs of foraging by increasing the value of time spent on social activities (social benefits hypothesis). A reduction in the costs of foraging caused by competition will reduce the quitting‐harvest rate of an optimal forager, whereas an increase in the value of alternative activities will increase the quitting‐harvest rate. Both hypotheses predict a reduction in optimal foraging time with increased density. The hypothesis that applies to Deer Mice (Peromyscus maniculatus, Wagner) was assessed by measuring their foraging activity and quitting‐harvest rates at control and reduced population densities on four study plots located in boreal forest in north‐western Ontario, Canada. Deer Mice increased theirper capitaforaging activity and their quitting‐harvest rates when population densities were reduced. The results confirm the very important role of competition in the behaviour of optimal foragers.
Gape size allometry in pike reflects variation between lakes in prey availability and relative body depth
Authors: MAGNHAGEN C. , HEIBO E. 
Published: March 2003

Summary

The gape size of the predator and the body depth of its prey are the main factors deciding whether a gape‐limited piscivore can ingest a potential prey fish. The connection between morphological variation in pike and its prey was studied in five lakes with different proportions of pike, perch and roach.
At low prey abundance the prey fish are larger than in lakes with a higher prey density. In contrast, the pike are smaller but have relatively high gapes in the lake with the lowest prey availability, and larger but with smaller gapes at the highest prey density. There is a positive correlation with relative gape size of pike and relative body depth of prey among the five lakes.
Using the body depth in perch and roach and the gape size in pike, the proportion of the prey populations that could be eaten by the pike was calculated. In the low prey density lakes the pike could ingest a smaller proportion of the prey than in the high prey density lakes where most pike can eat all available prey sizes.
Competition for food in a situation where prey are big may cause a selection for a higher gape size. Our results indicate that this mechanism could be the reason that pike from different lakes vary in relative gape size.
Calcium oxalate crystals in leaves ofPancratiumsickenbergeri: constitutive or induced defence?
Authors: Ruiz N. , Ward D. , Saltz D. 
Published: March 2003

Summary We investigated the genotypic effects of selection by herbivory by the dorcas gazelle,Gazella dorcasLinnaeus 1758, on the production of calcium oxalate crystals in the lilyPancratium sickenbergeriC. et Barbey in the Negev Desert.A completely crossed experimental design was used to assess the effects of soil calcium concentration and herbivory (simulated by clipping) on the production of calcium oxalate crystals in the leaves of plants from four source populations with different levels of herbivory. Soil calcium concentration did not have significant effects on the production of calcium oxalate crystals in the leaf. The number of crystals did not increase significantly with the clipping treatments. There was no significant difference among plants germinated from seed from populations with high or low herbivory in the production of calcium oxalate. There was a trade‐off between investment in defence versus investment in growth, suggesting a cost to defence. Experimentally clipped plants grew more than unclipped plants. Families from high‐herbivory areas had a stronger regrowth capacity in the absence of herbivory.Our results indicate that crystal production by these plants is not a sink for excess calcium uptake from the soil. We conclude that in this species calcium oxalate crystal production is for defence, and that this defence is constitutive rather than inducible. The environmental unpredictability in this desert leaves plants with few cues to the onset of herbivory. Constitutive defence may be a more appropriate strategy than inducible defence in this environment, particularly when herbivory is high, and leaves are ephemeral.
Thermoregulatory ecology of a solitary bat, Myotis evotis, roosting in rock crevices
Authors: Chruszcz B. J. , Barclay R. M. R. 
Published: March 2003

Summary

Most studies of the thermoregulatory ecology of bats have been limited to laboratory experiments or studies of individuals roosting in artificial structures.
We investigated the interaction between thermoregulatory behaviour and roost choice in reproductive female Western Long‐Eared Bats, Myotis evotis (H. Allen), roosting solitarily in natural rock crevices. The study was conducted in the badlands of the South Saskatchewan River Valley, Alberta, Canada, during 1997 and 1998.
Individuals used torpor every day and the amount of time spent in torpor was primarily influenced by the amount of time available to do so. Minimum body temperature was influenced by ambient temperature, although the form of this relationship differed between pregnant and lactating females. Pregnant females used deep torpor more frequently than lactating females.
All individuals roosted in rock crevices but pregnant and lactating females chose roosts that were different in structure and thermal characteristics. Pregnant females chose horizontal roosts that cooled at night but warmed quickly during the day, thus allowing passive rewarming from torpor. Lactating females chose vertical roosts that stayed warm at night when non‐volant pups were present, thereby minimizing thermoregulatory costs to the young.
The behaviours observed are adaptive, but differ from those of other temperate‐zone insectivorous bats that have been studied in the past. This highlights the importance of studying free‐ranging animals living in natural habitat if we are to have an accurate view of thermoregulatory strategies and the importance of roost characteristics for roost‐site selection.