bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erwinia chrysanthemi requires a second iron transport route dependent of the siderophore achromobactin for extracellular growth and plant infection
Authors: Franza Thierry , Mahé Bruno , Expert Dominique 
Published: December 2004

SummaryFull virulence of the pectinolytic enterobacterium Erwinia chrysanthemi strain 3937 depends on the production in planta of the catechol‐type siderophore chrysobactin. Under iron‐limited conditions, E. chrysanthemi synthesizes a second siderophore called achromobactin belonging to the hydroxy/carboxylate class of siderophore. In this study, we cloned and functionally characterized a 13 kb long operon comprising seven genes required for the biosynthesis (acs) and extracellular release (yhcA) of achromobactin, as well as the gene encoding the specific outer membrane receptor for its ferric complex (acr). The promoter of this operon was negatively regulated by iron. In a fur null mutant, transcriptional fusions to the acsD and acsA genes were constitutively expressed. Band shift assays showed that the purified E. chrysanthemi Fur repressor protein specifically binds in vitro to the promoter region of the acsF gene confirming that the metalloregulation of the achromobactin operon is achieved directly by Fur. The temporal production of achromobactin in iron‐depleted bacterial cultures was determined: achromobactin is produced before chrysobactin and its production decreases as that of chrysobactin increases. Pathogenicity tests performed on African violets showed that achromobactin production contributes to the virulence of E. chrysanthemi. Thus, during infection, synthesis of these two different siderophores allows E. chrysanthemi cells to cope with the fluctuations of iron availability encountered within plant tissues. Interestingly, iron transport mediated by achromobactin or a closely related siderophore probably exists in other phytopathogenic bacterial species such as Pseudomonas syringae.
Heterologous expression of Aquifex aeolicus ribosome recycling factor in Escherichia coli is dominant lethal by forming a complex that lacks functional co‐ordination for ribosome disassembly
Authors: Yamami Tohru , Ito Koichi , Fujiwara Toshinobu , Nakamura Yoshikazu 
Published: December 2004

SummaryRecycling the post‐termination ribosomal complex requires the co‐ordinated effort of the ribosome, ribosome  recycling  factor  (RRF)  and  elongation  factor EF‐G. Although Aquifex aeolicus RRF (aaRRF) binds Escherichia coli ribosomes as efficiently as E. coli RRF, the resulting complex is non‐functional and dominant lethal in E. coli, even in the presence of homologous A. aeolicus EF‐G. These findings suggest that the E. coli post‐termination ribosomal complex with aaRRF lacks functional co‐ordination with EF‐G required for ribosome recycling. A chimeric EF‐G (E. coli domains I–III, A. aeolicus domains IV–V) or an A. aeolicus EF‐G with distinct mutations in the domain I–II interface could activate aaRRF. Furthermore, novel mutations that localize to one surface of the  L‐shape  structure  of  aaRRF  restored  activity  in E. coli. These aaRRF mutations are spatially distinct from mutations previously described and suggest a novel active centre for coupling EF‐G's G domain motor action to ribosome disassembly.
Reticulocyte‐binding protein homologue 1 is required for sialic acid‐dependent invasion into human erythrocytes by Plasmodium falciparum
Authors: Triglia Tony , Duraisingh Manoj T. , Good Robert T. , Cowman Alan F. 
Published: December 2004

SummaryThe Apicomplexan parasite responsible for the most virulent form of malaria, Plasmodium falciparum, invades human erythrocytes through mutiple ligand–receptor interactions. Some strains of P. falciparum are sensitive to neuraminidase treatment of the host erythrocyte and these parasites have been termed sialic acid‐dependent as they utilize receptors containing sialic acid. In contrast, other strains can efficiently invade neuraminidase‐treated erythrocytes and hence are sialic acid‐independent. The molecular interactions that allow P. falciparum to differentially utilize receptors for merozoite invasion are not understood. The P. falciparum reticulocyte‐binding protein homologue (PfRh or PfRBL) family have been implicated in the invasion process but their exact role is unknown. PfRh1, a member of this protein family, appears to be expressed in all parasite lines analysed but there are marked differences in the level of expression between different strains. We have used targeted gene disruption of the PfRh1 gene in P. falciparum to show that the encoded protein is required for sialic acid‐dependent invasion of human erythrocytes. The ΔPfRh1 parasites are able to invade normally; however, they utilize a pattern of ligand–receptor interactions that are more neuraminidase‐resistant. Current data suggest a strategy based on the differential function of specific PfRh proteins has evolved to allow P. falciparum parasites to utilize alternative receptors on the erythrocyte surface for evasion of receptor polymorphisms and the host immune system.
Precipitation of pyroxenes and Mg2SiO4 from majoritic garnet: simulation of peridotite exhumation from great depth
Authors: Dobrzhinetskaya Larissa F. , Green Harry W. , Renfro Alex P. , Bozhilov Krassimir N. , Spengler Dirk , Van Roermund Herman L. M. 
Published: December 2004

AbstractOur experimental simulations of the exhumation path of mantle peridotites show that high‐temperature (1400 °C) decompression of lherzolite from 14 to 13 and 12 GPa results in exsolution of interstitial blebs of diopside and Mg2SiO4 (wadsleyite) lamellae from majoritic garnet. At lower pressures (from 8 to 5 GPa, at T = 1400 °C) only enstatite exsolves as blebs at garnet boundaries. Continuous high‐temperature decompression from 14 to 7 GPa produces zoned majoritic garnet containing blebs of exsolved pyroxenes inside garnet rims. No intracrystalline precipitation of pyroxene was observed in garnet, although such lamellae are found in some natural garnet peridotites. The explanation appears to be the three orders of magnitude difference in grain size between experimental and natural specimens. Our data suggest that Mg2SiO4 and diopside exsolutions reflect the deepest point of the exhumation path of garnet peridotites, whereas enstatite precipitation may be restricted to garnets with less majoritic component at shallower depths.
Organotemplate silica deposition in Neoproterozoic deep‐marine environments: evidence from the Penganga Group, Adilabad, India
Authors: Mukhopadhyay Joydip , Gutzmer Jens , Beukes Nicolas J. 
Published: December 2004

AbstractSilica in bedded cherts interstratified with manganese carbonates in a deep‐water carbonate ramp succession of the Neoproterozoic Penganga Group, India, displays film‐like, spherical to rod‐shaped, and tubular branching microstructures. The microstructures resemble mineralized extracellular polysaccharides, biofilms and bacterial morphologies. The microstructures suggest silicification by nucleation of silica on organic‐templates or indirectly as sorbed species accumulating on organic templates. Given that similar microstructures have also been documented in Archean cherts it is proposed that organotemplates might have been an important sink for the deposition of silica in Precambrian deep‐water marine environments.
How does micropetrography help us to understand the permeability and poromechanical behaviour of a rock?
Authors: Lion Maxime , Ledésert Béatrice , Skoczylas Frédéric , Recourt Philippe , Dubois Thierry 
Published: December 2004

AbstractMany poromechanical studies of rocks give little regard to the micropetrographic observation of their constituents. The aim of this study is to show how such a detailed study can help understand and provide more precision on the poromechanical behaviour of the material. The rock studied here is an oolitic limestone. Micropetrography reveals the nature of the constituents (calcite, mostly in the form of fine‐grained micrite), their abundance, their organization (micrite organized in ooids linked by a calcitic cement, small‐sized highly connected isotropic porosity, scarce unconnected porosity) and the structure of the rock (global isotropy, small heterogeneities due to sedimentological phenomena, no microcracks). Micropetrography completes the information obtained by poromechanics in that it allows the observation of elements deduced from macroscopical tests. The aim of this paper is to show the effect of microporosity on permeability and flow in a rock where microporous grains are in contact with each other.
A study on the routes of referral for patients with colorectal cancer and its affect on the time to surgery and pathological stage
Authors: Trickett J. P. , Donaldson D. R. , Bearn P. E. , Scott H. J. , Hassall A. C. 
Published: December 2004

AbstractObjective  Firstly, to determine the proportion of colorectal cancer (CRC) patients seen within an established two week rule (TWR) system and to observe other routes of referral for CRC patients. Secondly to determine if referral route affects the interval to, and cancer stage at, definitive treatment.Patients and methods  GP referrals of patients with CRC were divided into direct surgical outpatient referrals (group 1) and indirect referrals to accident and emergency and medical outpatients (group 2). Data were recorded on the time to definitive treatment and the location and stage of tumour.Results  There were 78 patients in group 1. Thirty (20%) patients were referred by their GP under the TWR, 31 (21%) as urgent and 17 (12%) as nonurgent referrals, to surgical outpatients. There were 69 patients in group 2. Forty‐two (29%) were referred initially to the accident and emergency department and 27 (18%) to general medical outpatients. Group 1 patients were treated within a median of 70.5 days and group 2 patients within 14 days of referral (P < 0.0005). Group 2 contained tumours of a significantly more advanced pathological stage (P = 0.015) and more proximal colonic cancers (P < 0.005).Conclusion  Fifty‐three percent of patients with CRC were referred directly to surgical outpatients, 20% under the TWR guidelines. Despite having this system in place direct referrals were slower to treatment but the tumours were still of a less advanced pathological stage. Compliance with the TWR should not be used as a means of assessing a colorectal unit's treatment of CRC.
The strength duration test: a novel tool in the identification of occult neuropathy in women with pelvic floor dysfunction
Authors: Telford K. J. , Faulkner G. , Hosker G. L. , Kiff E. S. , Hill J. 
Published: December 2004

AbstractObjective  The Strength‐duration test (SDT) is a simple minimally invasive measure of muscle innervation, recently adapted for the assessment of the external anal sphincter (EAS). This test can discriminate women with faecal incontinence from controls. The purpose of this study was to determine if the SDT could detect denervation of the EAS in women with weak but anatomically intact EAS and normal pudendal nerve terminal motor latency (PNTML).Patients and methods  Thirteen women with weak but intact EAS on endoanal ultrasound (EAUS) with normal maximum resting pressure and PNTML were recruited to undergo the SDT. The results from this group were compared to control data for the SDT previously collected in our unit.Results  Nine of 13 women were found to have SDT above a 95% confidence interval of the mean curve for controls and six had a SDT outside a 90% confidence interval for individuals derived from control data, suggesting denervation of the EAS. The mean area under the curve was significantly higher in our study group compared to controls (91.0 µsmA vs 72.2 µsmA, P = 0.047) as was the current intensity measured at the 1 ms pulse duration (18.2 mA vs 12.94 mA, P = 0.048), typical of denervation with this test.Conclusion  The SDT was abnormal in nine of the 13 study patients. This may partly explain reduced maximum voluntary contraction seen in this group of patients. SDT may be a more sensitive tool in detecting neuropathy than latency measurement.
Prospective follow‐up after ambulatory plain midline excision of pilonidal sinus and primary suture under local anaesthesia – efficient, sufficient, and persistent
Authors: Dalenbäck J. , Magnusson O. , Wedel N. , Rimbäck G. 
Published: December 2004

AbstractObjective  Optimal surgical treatment for chronic pilonidal sinus (PS) disease should be easy and efficient. The purpose of this study was to establish the feasibility of and results after ambulatory simple midline excision and primary wound closure under local anaesthesia.Patients and methods  The prospective nonrandomised single institution study included 131 consecutive PS patients admitted for surgery. After standardized surgery, all patients were prospectively followed until fully healed. Complications were registered. Results after 41 months (mean, range 36–59) were evaluated by questionnaire.Results  95% were primary closed. All were ambulatory treated and 98% under local anaesthesia. 88% healed in two weeks. 5.6% exhibited minor wound healing defects and 6.4% demanded full debridement of the wound. Mean delayed healing time was 7.5 weeks (range 3–12). 8% developed a recurrence. 10% of the remainders reported a slight tenderness in the scar area. 90% were symptom‐free.Conclusion  PS treatment as of above is readily achieved. Wound related complications were reasonably few and in the same magnitude as after more complex excision techniques and induced no significant long‐term sequels. Recurrences could, however, be more common. Prospective randomised studies are warranted to determine if there are any significant differences between excision techniques in and out of the midline.
Scintigraphic assessment of slow transit constipation with special reference to right‐ or left‐sided colonic delay
Authors: Lundin E. , Karlbom U. , Westlin J. E. , Kairemo K. , Jung B. , Husin S. , Påhlman L. , Graf W. 
Published: December 2004

AbstractObjective  Subtotal colectomy and ileorectal anastomosis for slow transit constipation has several side‐effects. The motor abnormality in some patients may be segmental which could motivate a limited resection of the colon. Therefore a diagnostic tool to identify a segmental colonic motor dysfunction is needed. The aim of this study was to evaluate a scintigraphic method to assess colonic transit with special reference to right‐ or left‐sided delay.Methods  Twenty‐three constipated patients (19 women, mean age 50 years) with slow colonic transit on radio‐opaque marker studies and 13 healthy individuals (11 women, mean age 46 years) were studied. All subjects were examined with oral 111Indium‐DTPA scintigraphy. The scintigraphic results for patients and controls were presented as geometric centre of radioactivity and percent activity over time in the right, the left and the recto‐sigmoid colon. The inter‐observer variation in the interpretation of the scans was also evaluated.Results  There was no difference in transit time between the groups of patients and controls in the right colon whereas the patients had a significant delay in the left colon (P < 0.05). Two patients had a marked delay in the right colon followed by relatively rapid transit in the left colon. The inter‐observer correlation was good comparing the right, the left and the recto‐sigmoid colon (r = 0.58–0.98, P < 0.01–0.001).Conclusion  The results indicate that colonic scintigraphy with oral 111Indium‐DTPA may help to select patients for a left or, in a few cases, a right hemicolectomy for slow transit constipation.
Blood loss and transfusion after total mesorectal excision and conventional rectal cancer surgery
Authors: Mynster T. , Nielsen H. J. , Harling H. , Bülow S. ,   Danish TME‐group and the RANX05‐group
Published: December 2004

AbstractObjectives  A recent study showed less bleeding and need of transfusion after total mesorectal excision (TME) compared with conventional rectal cancer surgery. The aim of this study was to evaluate this result in more details.Patients and methods  Comparison of transfusion history in rectal cancer resections in two different multicentre‐studies. Two hundred and forty‐six patients were operated in the period 1991–93 with a conventional technique and 311 patients were operated with TME‐technique in the period 1996–98. Peri‐operative data, including blood transfusion from one month before until one month after the operation, was recorded prospectively.Results  The median intra‐operative blood loss was 1000 ml, range 50–6000 ml, before, and 550 ml, range 10–6000 ml (P < 0.001) after introduction of TME. The overall peri‐operative transfusion rate was reduced from 73% to 43% (P < 0.001). When adjusted for blood loss, age, gender, weight, and type of resection, TME significantly reduced the risk of receiving intra or postoperative blood transfusion by 0.4 (CI: 0.3–0.6). The variability in blood loss among 12 TME‐centres was more than 400% and not correlated with transfusion requirements within the centres.Conclusion  TME results in a reduced blood loss and a reduction of blood transfusion, but additional factors others than blood loss seems to influence the decision of transfusion.
Absence of socioeconomic variation in survival from colorectal cancer in patients receiving surgical treatment in one health district: cohort study
Authors: Lyratzopoulos G. , Sheridan G. F. , Michie H. R. , McElduff P. , Hobbiss J. H. 
Published: December 2004

AbstractObjective  To examine whether there is an association between patient deprivation status and survival from colorectal cancer among patients receiving treatment of the same type and quality.Patients and methods  A survival study was conducted of all colorectal cancer patients diagnosed between 1991 and 1997 who received surgery either in the NHS district general hospital or the private hospital of one UK health district. The five‐year survival rates, both all cause and colorectal cancer specific, were calculated for subgroups defined by patient age, gender, stage and deprivation status using Kaplan‐Meier curves. Cox proportional hazards models were used to examine the influence of deprivation on five‐year survival after adjusting for age, gender and stage.Results  There were 603 consecutive colorectal patients during the study period. Five‐year all‐cause and colorectal cancer‐specific survival rates were 41% and 53%, respectively. There was no association between deprivation status and stage at diagnosis (P = 0.308). Multivariable proportional hazards modelling (adjusting for gender, age and tumour stage) demonstrated no association between deprivation status and survival.Conclusion  In this single district study, no relationship between patient socioeconomic status and survival from colorectal cancer could be demonstrated. Consistency in the type and quality of treatment offered to patients by the same clinical teams may have been responsible for the equitable survival outcomes.
Effects of mode of delivery and infant feeding on the risk of mother‐to‐child transmission of hepatitis C virus
Authors:   European Paediatric Hepatitis C Virus Network
Published: December 2004

Objective
To investigate the effects of mode of delivery and infant feeding on the risk of mother‐to‐child transmission of hepatitis C virus.Design
Pooled retrospective analysis of prospectively collected data.Sample
Data on hepatitis C virus seropositive mothers and their children identified around delivery were sent from 24 centres of the European Paediatric Hepatitis C Virus Network.Main outcome measures
Hepatitis C virus infection status of children born to hepatitis C virus infected women.Results
A total of 1,474 hepatitis C virus infected women were identified, of whom 503 (35%) were co‐infected with HIV. Co‐infected women were more than twice as likely to transmit hepatitis C virus to their children than women with hepatitis C virus infection alone. Overall 9.2% (136/1474) of children were hepatitis C virus infected. Among the women with hepatitis C virus infection‐only, multivariate analyses did not show a significant effect of mode of delivery and breastfeeding: caesarean section vs vaginal delivery OR=1.17, P=0.66; breastfed versus non‐breastfed OR=1.07, P=0.83. However, HIV co‐infected women delivered by caesarean section were 60% less likely to have an infected child than those delivered vaginally (OR=0.36, P=0.01) and those who breastfed were about four times more likely to infect their children than those who did not (OR=6.41, P=0.03). HIV infected children were three to four times more likely also to be hepatitis C virus infected than children without HIV infection (crude OR=3.76, 95% CI 1.89–7.41).Conclusions
These results do not support a recommendation of elective caesarean section or avoidance of breastfeeding for women with hepatitis C virus infection only, but the case for HIV infected women undergoing caesarean section delivery and avoiding breastfeeding is strengthened if they are also hepatitis C virus infected.
A randomised controlled trial comparing abdominal and vaginal prolapse surgery: effects on urogenital function
Authors: Roovers Jan‐Paul W.R. , van der Vaart C. Huub , van der Bom Johanna G. , Schagen van Leeuwen Jules H. , Scholten Piet C. , Heintz A. Peter M. 
Published: December 2004

Objective  To compare the effects of vaginal hysterectomy (combined with anterior and/or posterior colporraphy) and abdominal sacro‐colpopexy (with preservation of the uterus) on urogenital function.Design  Randomised trial.Setting  Three teaching hospitals in The Netherlands.Population  Eighty‐two patients undergoing surgical correction of uterine prolapse stages II–IV.Methods  Participating patients completed the urogenital distress inventory (UDI), before and at six weeks, six months and one year after surgery, to measure discomfort of prolapse and micturition symptoms. Domain scores of the UDI (ranging from 0 to 100, higher scores indicating more discomfort) were compared between groups at all time points. Findings at pelvic examination, number of doctor visits within the first year after surgery because of pelvic floor symptoms and performed or planned surgery of recurrent genital prolapse were also compared.Main outcome measure  Domain scores of the UDI at one year after surgery.Results  At one year after surgery, scores on the discomfort/pain domain (mean difference 7.1, 95% confidence interval [CI] 1.1–13.2), overactive bladder domain (mean difference 8.7, 95% CI 0.5–16.9) and obstructive micturition domain (mean difference 10.3, 95% CI 0.6–20.1) of the UDI were significantly higher in the abdominal group than in the vaginal group. Findings at pelvic examination were similar in both groups. Doctor visits because of pelvic floor symptoms were more frequent in the abdominal group than in the vaginal group. Re‐operation was performed or planned in 9 of the 41 patients who underwent abdominal surgery and in 1 of the 41 patients who underwent vaginal surgery (odds ratio [OR] = 11.2, 95% CI 1.4–90.0).Conclusions  Our findings suggest that vaginal hysterectomy with anterior and/or posterior colporraphy is preferable to abdominal sacro‐colpopexy with preservation of the uterus as surgical correction in patients with uterine prolapse stages II–IV.
Routine ultrasound for pregnancy termination requests increases women's choice and reduces inappropriate treatments
Authors: McGalliard Catherine , Gaudoin Marco 
Published: December 2004

This prospective observational study aimed to determine the correlation between gestational age based on menstrual dates and ultrasound scan in women requesting pregnancy termination and the proportion of cases where first trimester medical termination might be offered.Two hundred and sixty‐two women (93%) had ongoing pregnancies. Two hundred and thirty‐seven women (90%) were certain of their menstrual dates but there was a discrepancy of more than one week in gestational age in 38%. Calculated from their menstrual dates, 138 women might have been offered first trimester medical termination but this rose to 173 if gestation was based on ultrasound scan.From this study, we believe ultrasound should be performed routinely for all women requesting pregnancy termination.