bluuebunny/crossref_metadata_2025 huggingface dataset:
Cooperation of two distinct ExpR regulators controls quorum sensing specificity and virulence in the plant pathogen Erwinia carotovora
Authors: Sjöblom Solveig , Brader Günter , Koch Gudrun , Palva E. Tapio
Published: May 2006

Quorum sensing, the population density‐dependent regulation mediated by N‐acylhomoserine lactones (AHSL), is essential for the control of virulence in the plant pathogen Erwinia carotovora ssp. carotovora (Ecc). In Erwinia carotovora ssp. the AHSL signal with an acyl chain of either 6 or 8 carbons is generated by an AHSL synthase, the expI gene product. This work demonstrates that the AHSL receptor, ExpR1, of Ecc strain SCC3193 has strict specificity for the cognate AHSL 3‐oxo‐C8‐HSL. We have also identified a second AHSL receptor (ExpR2) and demonstrate a novel quorum sensing mechanism, where ExpR2 acts synergistically with the previously described ExpR1 to repress virulence gene expression in Ecc. We show that this repression is released by addition of AHSLs and appears to be largely mediated via the negative regulator RsmA. Additionally we show that ExpR2 has the novel property to sense AHSLs with different acyl chain lengths. The expI expR1 double mutant is able to act in response to a number of different AHSLs, while the expI expR2 double mutant can only respond to the cognate signal of Ecc strain SCC3193. These results suggest that Ecc is able to react both to the cognate AHSL signal and the signals produced by other bacterial species.
Establishment of a patterned GAL4‐VP16 transactivation system for discovering gene function in rice
Authors: Liang Dacheng , Wu Changyin , Li Caishun , Xu Caiguo , Zhang Jianwei , Kilian Andrzej , Li Xianghua , Zhang Qifa , Xiong Lizhong
Published: May 2006

A binary GAL4‐VP16–UAS transactivation system has been established in rice (Oryza sativaL.) in this study for the discovery of gene functions. This binary system consists of two types of transgenic lines, pattern lines and target lines. The pattern lines were produced by transformation of Zhonghua 11, a japonica cultivar, with a construct consisting of the transactivator geneGAL4‐VP16controlled by a minimal promoter and the GUSplus reporter controlled by the upstream activation sequence (UAS;cis‐element to GAL4). Target lines were generated by transformation of Zhonghua 11 with constructs carrying the EGFP reporter and target genes of interest, both controlled by the UAS but in opposite directions. Hybrid plants were obtained by crossing target lines of 10 putative transcription factor genes from rice with six pattern lines showing expression in anther, stigma, palea, lemma and leaves. The EGFP and target genes perfectly co‐expressed in hybrid plants with the same expression patterns as in the pattern lines. Various phenotypic changes, such as delayed flowering, multiple pistils, dwarfism, narrow and droopy leaves, reduced tillers, growth retardation and sterility, were induced as a result of the expression of the target genes. It is concluded that this transactivation system can provide a useful tool in rice to unveil latent functions of unknown or known genes.
Association of Arabidopsis type‐II ROPs with the plasma membrane requires a conserved C‐terminal sequence motif and a proximal polybasic domain
Authors: Lavy Meirav , Yalovsky Shaul
Published: May 2006

Plant ROPs (or RACs) are soluble Ras‐related small GTPases that are attached to cell membranes by virtue of the post‐translational lipid modifications of prenylation and S‐acylation. ROPs (RACs) are subdivided into two major subgroups called type‐I and type‐II. Whereas type‐I ROPs terminate with a conserved CaaL box and undergo prenylation, type‐II ROPs undergo S‐acylation on two or three C‐terminal cysteines. In the present work we determined the sequence requirement for association of Arabidopsis type‐II ROPs with the plasma membrane. We identified a conserved sequence motif, designated the GC‐CG box, in which the modified cysteines are flanked by glycines. The GC‐CG box cysteines are separated by five to six mostly non‐polar residues. Deletion of this sequence or the introduction of mutations that change its nature disrupted the association of ROPs with the membrane. Mutations that changed the GC‐CG box glycines to alanines also interfered with membrane association. Deletion of a polybasic domain proximal to the GC‐CG box disrupted the plasma membrane association of AtROP10. A green fluorescent protein fusion protein containing the C‐terminal 25 residues of AtROP10, including its polybasic domain and GC‐CG box, was primarily associated with the plasma membrane but a similar fusion protein lacking the polybasic domain was exclusively localized in the soluble fraction. These data provide evidence for the minimal sequence required for plasma membrane association of type‐II ROPs in Arabidopsis and other plant species.
Crosstalk between jasmonic acid, ethylene and Nod factor signaling allows integration of diverse inputs for regulation of nodulation
Authors: Sun Jongho , Cardoza Vinitha , Mitchell David M. , Bright Lydia , Oldroyd Giles , Harris Jeanne M.
Published: May 2006

Plant hormones interact at many different levels to form a network of signaling pathways connected by antagonistic and synergistic interactions. Ethylene and jasmonic acid both act to regulate the plant's responsiveness to a common set of biotic stimuli. In addition ethylene has been shown to negatively regulate the plant's response to the rhizobial bacterial signal, Nod factor. This regulation occurs at an early step in the Nod factor signal transduction pathway, at or above Nod factor‐induced calcium spiking. Here we show that jasmonic acid also inhibits the plant's responses to rhizobial bacteria, with direct effects on Nod factor‐induced calcium spiking. However, unlike ethylene, jasmonic acid not only inhibits spiking but also suppresses the frequency of calcium oscillations when applied at lower concentrations. This effect of jasmonic acid is amplified in the ethylene‐insensitive mutant skl, indicating an antagonistic interaction between these two hormones for regulation of Nod factor signaling. The rapidity of the effects of ethylene and jasmonic acid on Nod factor signaling suggests direct crosstalk between these three signal transduction pathways. This work provides a model by which crosstalk between signaling pathways can rapidly integrate environmental, developmental and biotic stimuli to coordinate diverse plant responses.
Caterpillar‐elicited methanol emission: a new signal in plant–herbivore interactions?
Authors: Von Dahl Caroline C. , Hävecker Michael , Schlögl Robert , Baldwin Ian T.
Published: May 2006

Plants release into the atmosphere large quantities of volatile organic compounds (VOCs), of which methanol (MeOH), a putative waste product, is the second most abundant. Using online proton‐transfer‐reaction mass spectrometry (PTR‐MS), we demonstrate that when Manduca sexta larvae attack Nicotiana attenuata plants, the wound‐induced release of MeOH dramatically increases. The sustained MeOH emission 24 h after herbivore feeding is already substantially greater than the release of the well‐characterized green‐leaf VOC E‐2‐hexenal. Herbivore attack and treatment of puncture wounds with larval oral secretions (OS) increased the transcript accumulation and activity of leaf pectin methylesterases (PMEs), and decreased the degree of pectin methylation, as determined by 1H‐NMR; therefore, we propose that the released MeOH originates from the activation of PMEs by herbivore attack. The herbivore‐ and OS‐elicited MeOH results not from the activity of previously characterized elicitors in OS but from a pH shift at the wound site when larval OS (pH 8.5–9.5) are introduced into the wounds during feeding. Applying MeOH to plants in quantities that mimic the herbivory‐elicited release decreases the activity of the potent plant defense proteins trypsin proteinase inhibitors (TPI), and increases the performance of the attacking larvae. The pH of lepidopteran larvae regurgitants is commonly very high, and the MeOH released during feeding that is elicited by the pH change at the wound site functions as a quantitative signal that influences the outcome of the plant–herbivore interaction.
Katanin's severing activity favors bundling of cortical microtubules in plants
Authors: Stoppin‐Mellet Virginie , Gaillard Jérémie , Vantard Marylin
Published: May 2006

Higher plant cells exhibit interphase microtubule arrays specific to plants, which are essential for their developmental program. These cortical microtubules (CMT) consist of a population of highly dynamic microtubules that are usually organized into bundles in the cortex of the cells. The organization of CMT is intimately linked to the acquisition of specialized functions, and subsequentchanges in their distribution affect their properties. The mechanisms underlying the formation and the distribution of CMT are still unclear, and little is known about the proteins that are involved in this phenomenon. Here we investigated the putative role of katanin, the only known plant microtubule‐severing protein, in the organization of CMT. We generated transgenic Arabidopsis lines that overexpress katanin under the control of an ethanol‐inducible promoter. In response to an induced overexpression of katanin, CMT organized into numerous and thick bundles, which ultimately depolymerized. From the analyses of CMT patterns together with recent data on CMT dynamics, we propose that, in interphase cells, katanin's main activity is to free CMT, generating motile microtubules that incorporate into bundles.
Characterization and functional analysis of ABSCISIC ACID INSENSITIVE3‐like genes from Physcomitrella patens
Authors: Marella Heather H. , Sakata Yoichi , Quatrano Ralph S.
Published: May 2006

Although the moss Physcomitrella patens is known to respond to abscisic acid (ABA) by activating gene expression, the transcriptional components involved have not been characterized. Initially, we used the ABA‐responsive Em promoter from wheat linked to β‐glucuronidase (GUS) to determine whether ABI3/VP1, transcriptional regulators in the ABA‐signaling pathway in angiosperms, were similarly active in the ABA response of P. patens. We show by particle bombardment that ABI3 and VP1 affect Em–GUS expression in P. patens in a manner similar to angiosperms. We also show the involvement of ABI1 in the pathway, utilizing the abi1‐1 mutant allele. We isolated three ABI3‐like genes from P. patens. Using an Em‐like ABA‐responsive promoter from P. patens (PpLea1), we demonstrate that PpABI3A, only in the presence of ABA, strongly enhances PpLea1–GUS expression in P. patens. PpABI3A also enhances ABA‐induced Em–GUS expression in P. patens. In barley aleurone, PpABI3A transactivates Em–GUS but to a lesser extent than VP1 and ABI3. PpABI3A:GFP is localized to the nucleus of both protonemal cells and barley aleurone, indicating that the nuclear localization signals are conserved. We show that at least a part of the inability of PpABI3A to fully complement the phenotypes of the Arabidopsis abi3‐6 mutant is due to a weak interaction between PpABI3A and the bZIP transcription factor ABI5, as assayed functionally in barley aleurone and physically in the yeast‐two‐hybrid assay. Our data clearly demonstrate that P. patens will be useful for comparative structural and functional studies of components in the ABA‐response pathway such as ABI3.
Impaired sucrose induction1 encodes a conserved plant‐specific protein that couples carbohydrate availability to gene expression and plant growth
Authors: Rook Fred , Corke Fiona , Baier Margarete , Holman Rachel , May Alexander G. , Bevan Michael W.
Published: May 2006

To identify the molecular mechanisms underlying carbohydrate allocation to storage processes, we have isolated mutants in which the sugar induction of starch biosynthetic gene expression was impaired. Here we describe the IMPAIRED SUCROSE INDUCTION1 (ISI1) gene, which encodes a highly conserved plant‐specific protein with structural similarities to Arm repeat proteins. ISI1 is predominantly expressed in the phloem of leaves following the sink‐to‐source transition during leaf development, but is also sugar‐inducible in mesophyll cells. Soil‐grown isi1 mutants show reduced plant growth and seed set compared to wild‐type Arabidopsis. This growth reduction is not due to reduced carbohydrate availability or a defect in sucrose export from mature leaves, suggesting that isi1 mutant plants do not utilize available carbohydrate resources efficiently. ISI1 interacts synergistically with, but is genetically distinct from, the abscisic acid (ABA) signalling pathway controlling sugar responses via ABI4. Our data show that ISI1 couples the availability of carbohydrates to the control of sugar‐responsive gene expression and plant growth.
Long‐term lamivudine monotherapy prevents development of hepatitis B virus infection in hepatitis B surface‐antigen negative liver transplant recipients from hepatitis B core‐antibody‐positive donors
Authors: Prakoso Emilia , Strasser Simone I. , Koorey David J. , Verran Deborah , McCaughan Geoffrey W.
Published: May 2006

Abstract:  Background:  Liver transplantation from hepatitis B core‐antibody (HBcAb)‐positive donors to hepatitis B surface‐antigen (HBsAg)‐negative recipients has been associated with a risk of hepatitis B virus (HBV) infection in the absence of antiviral prophylaxis. The aim of this study is to assess the efficacy of long‐term lamivudine monotherapy to prevent development of HBV infection in HBsAg‐negative recipients of liver allografts from HBcAb‐positive donors.

Methods:  From 315 cadaveric adult liver transplantations performed at our unit between July 1999 and March 2005, 18 recipients (5.7%) received liver allografts from HBcAb‐positive donors, 13 of whom were HBsAg‐negative pre‐transplantation. The recipients consisted of four females and 14 males, age range 28–65 yr (median 49.5 yr). Post‐transplantation, HBsAg‐negative recipients were administered lamivudine 100 mg daily long term. HBsAg‐positive recipients were administered low‐dose hepatitis B immunoglobulin (HBIg) and lamivudine according to our usual protocol. Standard post‐transplantation immunosuppression was given. Recipients were followed up regularly (range 2–69 months, median 21 months) for development of de novo HBV infection.

Results:  Ten HBsAg‐negative recipients received long‐term lamivudine. One patient (HBcAb and HBsAb positive pre‐transplant) did not receive lamivudine and, in two patients, lamivudine was discontinued following urgent re‐transplantation for primary graft non‐function. All 13 of the HBsAg‐negative recipients were still alive, with no evidence of HBV infection at the end of follow‐up.

Conclusion:  Long‐term lamivudine monotherapy was effective in preventing development of HBV infection in HBsAg‐negative liver transplant recipients from HBcAb‐positive donors.
Gender‐associated risk factors for cardiac end points and total mortality after renal transplantation: post hoc analysis of the ALERT study
Authors: Øien Cecilia Montgomery , Reisæter Anna Varberg , Os Ingrid , Jardine Alan , Fellström Bengt , Holdaas Hallvard
Published: May 2006

Abstract:  Background:  Female gender offers a cardioprotective effect over men in the general population, but is lost in the dialysis population. Whether renal transplantation restores the gender‐dependent cardiac protection and whether there is a difference in the impact of risk factors is not known.

Methods:  This is a post hoc analysis of pre‐defined end points in the placebo arm in the Assessment of Lescol in Renal Transplantation (ALERT) study, a study in renal transplant recipients. Cox regression was performed to estimate the association between different risk factors at baseline and non‐fatal myocardial infarction (MI) or cardiac death and total mortality, and specifically assess whether there are gender differences.

Results:  The placebo arm included 1052 patients (mean age 50.1 ± 11.1 yr, 65.3% males) with a mean follow‐up of 65 months. The incidence of non‐fatal MI or cardiac death was 10.9% vs. 7.9% (NS) and total mortality 13.3% vs. 12.8% (NS) in men and women. In multivariate analysis, previous coronary heart disease (CHD), diabetes, treatment for rejection and serum triglycerides were predictive for cardiac events in men, and low‐density lipoprotein (LDL)/high‐density lipoprotein (HDL) ratio only in women. A slightly different risk‐factor pattern appeared for total mortality. Diabetes, ECG abnormalities, plasma triglycerides, serum creatinine, time on dialysis and age predicted total mortality in men, while ECG abnormalities, LDL/HDL ratio and age were predictors in women.

Conclusion:  In this relatively low‐risk population of renal transplant recipients, no gender difference in cardiac events or total mortality was observed, suggesting that female gender advantage regarding CHD is not restored following transplantation. The predictive value of risk factors differed in men and women.
Osteoprotegerin and receptor activator of nuclear factor‐κB ligand system in the early post‐operative period of liver transplantation
Authors: Fábrega Emilio , Orive Aitor , García‐Unzueta Maite , Amado Jose Antonio , Casafont Fernanado , Pons‐Romero Fernando
Published: May 2006

Abstract:  Background:  The precise mechanism that leads to accelerated bone resorption in the early post‐transplant period remains unclear. Recent data suggest that osteoprotegerin (OPG) and its ligand receptor activator of nuclear factor‐κB ligand (RANKL) constitute a novel cytokine system that can influence the function of both bone and immune cells. The aim of our study was to assess OPG and RANKL concentrations in the early post‐operative period of liver transplantation.

Methods:  Serum OPG and RANKL levels were measured in 30 patients who underwent liver transplantation at 1, 7 and 14 d post‐operatively. These values were compared with 22 age‐ and sex‐matched healthy controls. Plasma sodium, creatinine, aspartate‐aminotransferase, alanine‐amino transferase, γ‐glutamyl transferase, alkaline phosphatase, bilirubin, albumin, prothrombin time, tacrolimus and cyclosporine levels were measured in each patient.

Results:  We found a significant increase in OPG levels in the early post‐operative period compared with the control group: day 1 (10.42 pmol/L, range 3.80–17.50 vs. 3.91 pmol/L, range 1.20–6.60; p = 0.0001), day 7 (6.90 pmol/L, range 3.00–15.30 vs. 3.91 pmol/L, range 1.20–6.60; p = 0.0001) and day 14 (5.76 pmol/L, range 2.60–10.70 vs. 3.91 pmol/L, range 1.20–6.60; p = 0.001). Similarly, serum RANKL levels were significantly higher than in the control group in this period, day 1 (0.123 pmol/L, range 0.010–0.420 vs. 0.054 pmol/L, range 0.010–0.300; p = 0.02), day 7 (0.236 pmol/L, range 0.010–0.720 vs. 0.054 pmol/L, range 0.010–0.300; p = 0.0004) and day 14 (0.137 pmol/L, range 0.010–0.520 vs. 0.054 pmol/L, range 0.010–0.300; p = 0.007). No correlation was found between OPG levels and RANKL, ischemic times, liver function tests, albumin, sodium or creatinine concentrations and tacrolimus or cyclosporine levels.

Conclusions:  A significant amount of OPG and RANKL is released in the early post‐transplant period of liver transplantation. This might be explained by an activation of the immune system caused by the allograft. Therefore, the RANKL/OPG system may be involved in the pathophysiological evolution of transplantation osteoporosis.
Long‐term outcomes of single paediatric vs. ideal adult renal allograft transplants in adult recipients
Authors: Csapo Zsolt , Knight Richard J. , Podder Hemangshu , Kerman Ronald H. , Schoenberg Linda , Katz Stephen M. , Van Buren Charles T. , Kahan Barry D.
Published: May 2006

Abstract: Aim: To compare the outcomes of single paediatric vs. adult kidneys transplanted into adult recipients,

Methods: A retrospective single‐centre review of 38 single cadaver kidney transplants from donors less than five yr of age to wait‐listed patients of low body mass index (BMI). Survival of grafts and quality of renal function were compared with 121 similarly low BMI recipients of grafts from donors 18–45 yr of age that were transplanted during the same period. Immunosuppression consisted of sirolimus, minimal‐dose cyclosporine and prednisone. The mean age of the paediatric vs. adult donors was 2.8 ± 1.0 and 31.1 ± 9.2 yr, respectively (p<0.01) and of the recipients, 42.0 ± 12.4 and 45.7 ± 14.8 yr, respectively (p = NS). The mean BMI of paediatric vs. adult donor kidney recipients was 21.8 ± 2.9 and 22.4 ± 2.0 kg/m2(p = NS). Sixty‐six per cent of paediatric donor recipients were women compared with 44% of adult donor recipients (p = 0.03).

Results: Death censored actuarial graft survivals at one and five yr for recipients of paediatric vs. adult donor grafts were 93 and 84% compared with 93 and 85% (p = NS). There were no graft losses because of technical complications in the paediatric kidney donor group. At one and five yr post‐transplantation, the mean estimated creatinine clearances of the paediatric donor graft recipients were 52.9 ± 19.6 and 54.0 ± 17.8 mL/min, respectively, compared with 56.4 ± 19.8 and 49.1 ± 21.7 mL/min for recipients of adult donor grafts at the same times (p = NS).

Conclusion: Transplantation of single paediatric donor kidneys into low BMI adult recipients provided equivalent outcomes to those of grafts from adult donors between the ages of 18 and 45 yr.
Short‐term testing of heart rate variability in heart‐transplanted children: equal to 24‐h ECG recordings?
Authors: Dalla Pozza R. , Fuchs A. , Bechtold S. , Netz H.
Published: May 2006

Abstract: Introduction: Heart rate variability (HRV) is reduced in adults and children after cardiac transplantation. Testing of HRV has been used to assess re‐innervation of the cardiac graft; its reliability in ruling out acute graft rejection is still under investigation. This study used a short‐term test on HRV in 23 heart and heart–lung transplanted children and adolescents and compared the results with 24‐h ECG recordings.

Patients and methods: Twenty‐three subjects (16.3 ± 4.2 yr; 10 females) underwent a 10‐min HRV test at two occasions and one 24‐h ECG. HRV was calculated according to the time domain method (RR interval, standard deviation of RR interval) and the frequency domain method (total power, LF and HF for assessment of sympathovagal modulation of heart rate).

Results: Correlation between the short‐term tests and 24‐h ECG was high with regard to the frequency domain analysis of HRV. Correlation was less pronounced in the time domain method.

Conclusions: In heart and heart–lung‐transplanted children and adolescents, due to reduced overall HRV short‐term testing may give as reliable data as 24‐h ECG. Therefore, especially when power spectral analysis has to be performed as a longitudinal assessment of re‐innervation of the cardiac graft, short‐term testing may offer an easily applicable and non‐invasive diagnostic tool. Further studies are warranted to investigate whether HRV testing may contribute to rule out acute graft rejection.
A nomogram for predicting the optimal oral dosage of tacrolimus in liver transplant recipients with small‐for‐size grafts
Authors: Kishino Satoshi , Ohno Keiko , Shimamura Tsuyoshi , Furukawa Hiroyuki , Todo Satoru
Published: May 2006

Abstract:  No optimal tacrolimus dosage regimen suitable for clinical use in liver transplant recipients has yet been established. The purpose of this study was to determine the factors affecting the optimal dosage and pharmacokinetics of tacrolimus in living donor liver transplantation, and a nomogram for optimal tacrolimus dosage in the immediate postoperative period for recipients with small‐for‐size grafts was constructed. Twenty‐four liver transplant patients (nine males and 15 females) and 24 donors (10 males and 14 females) were enrolled in this study. Two studies were performed. In study 1, the effect of the actual ratio of graft volume to standard liver volume (GV/SV ratio) on the elimination half‐life (T1/2) of tacrolimus in the immediate postoperative period was analysed, and a nomogram for estimating the optimal oral dose of tacrolimus required to reach a target concentration was established. In study 2, the effect of donor age on the recovery of hepatic function with ability of the graft to eliminate tacrolimus was analysed. In the immediate postoperative period, T1/2 of tacrolimus showed great variability between patients, with values ranging from 16.3 to 110.9 h. Graft size (GV/SV ratio) is important and could influence intraindividual variations in the optimal dosage and T1/2 of tacrolimus. The recovered T1/2 ratio (T1/2 ratio=T1/2 1–10 d/T1/2 30–40 d), this ratio being related to the recovery of hepatic function with ability of the graft to eliminate tacrolimus, showed great variability between patients, with values ranging from 1.08 to 4.21 (mean±SD, 1.95±0.81). Age of the donor is a major factor affecting the recovered ratio of the graft to metabolize tacrolimus. The nomogram that we have constructed, based on graft size (GV/SV ratio), will easily provide optimal dose for each patient with small‐for‐size graft in the early postoperative period.
De novo gastrointestinal tumours after renal transplantation: Role of CMV and EBV viruses
Authors: Adani Gian Luigi , Baccarani Umberto , Lorenzin Dario , Gropuzzo Maria , Tulissi Patrizia , Montanaro Domenico , Currö Giuseppe , Sainz Mauricio , Risaliti Andrea , Bresadola Vittorio , Bresadola Fabrizio
Published: May 2006

Abstract:  The development of new and more effective immunosuppressive agents has provided long‐term survival for transplant recipients, thereby increasing the risk of de novo malignancy in chronic immunocompromised hosts. While de novo post‐transplant lymphoproliferative diseases and skin cancer has been shown to have an increased incidence in long‐term surviving solid organ transplant recipients, the association with gastrointestinal (GI) cancer is controversial. Over 12 yr, 20 patients (5%) out of 395 renal transplant recipients developed 23 de novo tumours; 11 skin cancer and 12 non‐skin cancer. Four patients (1%) developed de novo tumours of the GI tract (three colon, and one gastric cancer). Immediately after tumour's diagnosis, immunosuppressive therapy was reduced; all patients were shifted from cyclosporine to Rapamicine within 30 d. The tumour was surgically resected with curative intent in three cases, while one patient had only palliative surgery because of metastatic disease. The post‐operative courses was uneventful. All patients maintained normal graft function. However, three out of four patients (75%) died of progression of the neoplasm, within a median time from the diagnosis of 12 months. Further, we investigated a possible correlations between de novo GI cancer and HCV, HBV status, infections, cytomegalovirus (CMV) and Epstein–Barr virus (EBV) reactivation, episodes of rejection, and blood transfusions. All cases with GI de novo cancers reported in this paper developed CMV and EBV reactivation within three months after transplantation. Thereafter we suggest a closer follow‐up for de novo GI cancer in renal transplants with early CMV and EBV reactivation in order to avoid delayed diagnosis.
Soluble CD30 concentrations in ESRD patients with and without panel reactive HLA antibodies
Authors: Vaidya Smita , Partlow David , Barnes Titus , Thomas Phillip , Gugliuzza Kristin
Published: May 2006

Abstract:  Background:  In this retrospective study we compared accuracy of panel reactive antibodies (PRA) with serum soluble CD30 (sCD30) contents in predicting acute rejection crisis post‐renal transplant.

Methods:  Pre‐transplant sera from 115 patients were evaluated for their PRA and sCD30 concentrations. All patients received calcineurin inhibitor‐based immunosuppressive therapy. Objective measurements for rejection were biopsy‐proven acute rejection (AR) episodes within first six months of the transplant. Post‐transplant sera of patients with AR were tested for the presence of donor‐specific HLA antibodies (DSA).

Results:  Overall AR rate was 16% (18/115). Patients positive for PRA and sCD30 tests were at significantly higher risk for AVR compared with those patients negative for both the tests (36% vs. 5%, p = 0.01). Among negative PRA patients risk for AR was significantly elevated if they were also tested positive for sCD30 concentrations (21% vs. 5%, p = 0.04). Of the 18 patients with AR, 14 were positive for sCD30, and 13 of them (93%) developed DSA post‐transplant (p = 0.001).

Conclusion:  These data showed that patients positive for sCD30 contents are at high risk for the development of DSA and AR post‐transplant regardless of their pre‐transplant PRA.
Recurrent hepatitis C virus disease after liver transplantation and concurrent biliary tract complications: poor outcome
Authors: Katz Lior H. , Mor Eitan , Brown Marius , Bar‐Nathan Nathan , Shaharabani Ezra , Sulkes Jaqueline , Pappo Orit , Tur‐Kaspa Ran , Ben‐Ari Ziv
Published: May 2006

Abstract:  Recurrent hepatitis C virus (HCV) infection is particularly aggressive in the post‐liver transplantation setting, with rapid progression of liver fibrosis. Biliary complications remain a significant cause of morbidity following liver transplantation. Post‐cholecystectomy biliary strictures are associated with advanced hepatic fibrosis. The aim of this retrospective study was to determine whether the presence of biliary complications affects survival in liver transplant recipients with recurrent HCV disease. The files of liver transplant recipients (53.7% male; mean age 52.7 ± 10.3 yr) were reviewed for incidence, type and treatment of biliary complications, and findings were compared between those who developed recurrent HCV disease (n = 47, 83.9%) and those who did not (n = 9). Twenty‐one biliary complications developed in 12 patients with recurrent HCV (25.5%). Treatment with endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography with balloon dilatation and stent placement or surgical revision was successful in nine (75%). Three biliary complications developed in three patients with no recurrence (p = NS). There was no statistically significant association between recurrent HCV disease and biliary complications. However, among those with recurrent disease, the recurrence was severe in nine of 12 recipients with biliary complications (75%) but in only nine of 35 without biliary complications (26%) (p = 0.001). Death was documented in eight patients with severe recurrence (44.4%), including three (37.5%) with biliary complications and two (7%) with non‐severe recurrence, neither of whom had biliary complications (p = 0.003). Antiviral treatment was successful in nine of 25 patients (36%) who received it. On multivariate analysis, biliary complications were a significant predictor of severe recurrence (OR 27.0, 95% confidence interval 2.07–351.4) (p = 0.012). Fibrosis stage in the second biopsy was significantly correlated with serum alanine aminotransferase (p = 0.01) and with duration of biliary obstruction (p = 0.07). In conclusion, biliary complications of liver transplantation strongly affect outcome in patients with recurrent HCV disease despite attempts to relieve the biliary obstruction and to treat the recurrent HCV disease.
The advantage of allocating kidneys from old cadaveric donors to old recipients: a single‐center experience
Authors: Bodingbauer M. , Pakrah B. , Steininger R. , Berlakovich G. , Rockenschaub S. , Wekerle T. , Muehlbacher F.
Published: May 2006

Abstract:  Background:  In January 1999 a new kidney allocation program was launched by the Eurotransplant Foundation, the ‘Eurotransplant Senior Program’ (ESP). Cadaveric donors above the age of 65 yr are allocated to kidney transplant recipients of the same age group.

Methods:  Using a single‐center database, 91 patients who underwent first renal transplantation at the age of 65 yr and older in the years 1999–2002 were identified. Fifty‐six patients were transplanted through ESP allocation (study group) and 35 patients (control group) via normal Eurotransplant Kidney Allocation System (ETKAS) procedure.

Results:  Age, sex and comorbid conditions did not differ by group. The rate of acute rejection episodes, primary non‐function, delayed graft function, perioperative mortality did not differ by group. Serum creatinine was significantly lower in the ETKAS group (1.3 vs. 1.9 mg/dL; p = 0.015) from six months after the transplantation on. Overall graft survival at six yr was 56% in the ETKAS group and 52% in the ESP group. With 73% in the ETKAS group and 71% in the ESP group, cumulative patient survival according to the Kaplan–Meier estimation was not statistically different at five yr.

Conclusions:  We did not find a relevant difference in the outcome between young and old kidney transplants in old recipients after this long observation period.
Management of the sensitized cardiac recipient: the use of plasmapheresis and intravenous immunoglobulin
Authors: Leech S.H. , Lopez‐Cepero M. , LeFor W.M. , DiChiara L. , Weston M. , Furukawa S. , Macha M. , Singhal A. , Wald J.W. , Nikolaidis L.A. , McClurken J.B. , Bove A.A.
Published: May 2006

Abstract: Previously, we reported that the combination of plasmapheresis (PP) and intravenous immunoglobulin (IVIg) allow sensitized patients to undergo orthotopic heart transplantation (OHT), even across a positive crossmatch. In the current study, the effect of that combination, PP +IVIg, on survival of a larger group of such recipients is investigated. The latter group (I) consisted of 35 sensitized patients who received PP + IVIG together with standard immunosuppressive drugs. Rejection was seen in 11 patients, findings strongly suggestive of a vascular (humoral) being identified in five of those cases. Four deaths occurred, two of them in the immediate post‐operative period, one after almost six months, and one after almost two yr post‐OHT. Follow‐up range 4.5 months to 7.8 yr post‐OHT (average = 1.1 yr). Patient survival was analyzed after generation of a Kaplan–Meier plot. Comparison with a control OHT group (II) given standard immunosuppressive drugs only (N = 276) showed enhanced survival of group I (p = 0.0414 by log‐rank test). We conclude that the combination of PP and IVIG (i) is associated with declines in T‐ and B‐percent‐reactive antibody and in crossmatch positivity, and (ii) is very useful in the management of the sensitized cardiac patient undergoing OHT, often allowing a successful outcome to transplantation in the face of a positive crossmatch.
Host–parasite interactions for virulence and resistance in a malaria model system
Authors: Grech K. , Watt K. , Read A. F.
Published: May 2006

A rich body of theory on the evolution of virulence (disease severity) attempts to predict the conditions that cause parasites to harm their hosts, and a central assumption to many of these models is that the relative virulence of pathogen strains is stable across a range of host types. In contrast, a largely nonoverlapping body of theory on coevolution assumes that the fitness effects of parasites on hosts is not stable across host genotype, but instead depends on host genotype by parasite genotype interactions. If such genetic interactions largely determine virulence, it becomes difficult to predict the strength and direction of selection on virulence. In this study, we tested for host-by-parasite interactions in a medically relevant vertebrate disease model: the rodent malaria parasite Plasmodium chabaudi in laboratory mice. We found that parasite and particularly host main effects explained most of the variance in virulence (anaemia and weight loss), resistance (parasite burden) and transmission potential. Host-by-parasite interactions were of limited influence, but nevertheless had significant effects. This raises the possibility that host heterogeneity may affect the rate of any parasite response to selection on virulence. This study of rodent malaria is one of the first tests for host-by-parasite interactions in any vertebrate disease; host-by-parasite interactions typical of those assumed in coevolutionary models were present, but were by no means pervasive.
RNA world – the dark matter of evolutionary genomics
Authors: Michalak P.
Published: May 2006

For a long time, molecular evolutionary biologists have been focused on DNA and proteins, whereas RNA has lived in the shadow of its famous chemical cousins as a mere intermediary. Although this perspective has begun to change since genome-wide transcriptional profiling was successfully extended to evolutionary biology, it still echoes in evolutionary literature. In this mini-review, new developments of RNA biochemistry and transcriptomics are brought to the attention of evolutionary biologists. In particular, the unexpected abundance and functional significance of noncoding RNAs is briefly reviewed. Noncoding RNAs control a remarkable range of biological pathways and processes, all with obvious fitness consequences, such as initiation of translation, mRNA abundance, transposon jumping, chromosome architecture, stem cell maintenance, development of brain and muscles, insulin secretion, cancerogenesis and plant resistance to viral infections.
Increased male mating rate in Drosophila is associated with Wolbachia infection
Authors: De Crespigny F. E. Champion , Pitt T. D. , Wedell N.
Published: May 2006

The maternally inherited bacterium Wolbachia pipientis infects 25–75% of arthropods and manipulates host reproduction to improve its transmission. One way Wolbachia achieves this is by inducing cytoplasmic incompatibility (CI), where crosses between infected males and uninfected females are inviable. Infected males suffer reduced fertility through CI and reduced sperm production. However, Wolbachia induce lower levels of CI in nonvirgin males. We examined the impact of Wolbachia on mating behaviour in male Drosophila melanogaster and D. simulans, which display varying levels of CI, and show that infected males mate at a higher rate than uninfected males in both species. This may serve to increase the spread of Wolbachia, or alternatively, may be a behavioural adaptation employed by males to reduce the level of CI. Mating at high rate restores reproductive compatibility with uninfected females resulting in higher male reproductive success thus promoting male promiscuity. Increased male mating rates also have implications for the transmission of Wolbachia.
Variation in the intensity of inbreeding depression among successive life-cycle stages and generations in gynodioecious Silene vulgaris (Caryophyllaceae)
Authors: Glaettli M. , Goudet J.
Published: May 2006

Inbreeding depression is one of the hypotheses explaining the maintenance of females within gynodioecious plant populations. However, the measurement of fitness components in selfed and outcrossed progeny depends on life-cycle stage and the history of inbreeding. Comparative data indicate that strong inbreeding depression is more likely to occur at later life-cycle stages. We used hermaphrodite individuals of Silene vulgaris originating from three populations located in different valleys in the Swiss Alps to investigate the effect of two generations of self- and cross-fertilization on fitness components among successive stages of the life cycle in a glasshouse experiment. We detected significant inbreeding depression for most life-cycle stages including: the number of viable and aborted seeds per fruit, probability of germination, above ground biomass, probability of flowering, number of flowers per plant, flower size and pollen viability. Overall, the intensity of inbreeding depression increased among successive stages of the life cycle and cumulative inbreeding depression was significantly stronger in the first generation (δ ≈ 0.5) compared with the second generation (δ ≈ 0.35). We found no evidence for synergistic epistasis in our experiment. Our finding of more intense inbreeding depression during later stages of the life cycle may help to explain the maintenance of females in gynodioecious populations of S. vulgaris because purging of genetic load is less likely to occur.
Intraoperative and postoperative risk factors for prolonged mechanical ventilation after pediatric cardiac surgery
Authors: SZÉKELY ANDREA , SÁPI ERZSÉBET , KIRÁLY LÁSZLÓ , SZATMÁRI ANDRÁS , DINYA ELEK
Published: May 2006

Background:  Early extubation after cardiac surgery in children is feasible; however, predictors of prolonged mechanical ventilation (MV) should be recognized as soon as possible.

Methods:  At a tertiary pediatric cardiac center, prospective case series analyses were carried out with a total of 411 patients within 1 year of cardiac surgery. Perioperative factors were evaluated for strength of association with duration of MV >61 h (medium, MMV) and >7 days (long, LMV). Two multiple regression models were performed for both cut‐off points: one model considered factors identified until 24 h postoperation, the other was performed with all parameters.

Results:  One hundred and three patients (25%) were still intubated after 61 h; 38 patients required LMV and they occupied 33% of total intensive care unit (ICU) bed days. If factors occurring until 24 h after surgery were analyzed, duration of cardiopulmonary bypass (CPB), intraoperative transfusion, post‐CPB arterial oxygen tension (PaO2/FiO2), and fluid intake on the first day were found to be associated with MMV. Urea nitrogen value, nitric oxide treatment, delayed sternal closure, and tracheobronchomalacia, measured at the same point of time, were independent predictors of LMV. Of all the studied clinical predictors, MMV was associated with pulmonary hypertensive events, delayed sternal closure, peritoneal dialysis, nonvascular pulmonary problems, low output syndrome and fluid intake, while urea nitrogen (24 h), postsurgical neurological events, nitric oxide, tracheobronchomalacia, pulmonary hypertensive events and cardiac reoperations were identified as determinants of LMV.

Conclusions:  Causes of MV after surgery are heterogeneous, vary with time, and have variable impact on the duration of MV.
Cardiac arrest at induction of anesthesia in a child with undiagnosed right‐ventricular dependent coronary circulation: a case report
Authors: BROWN TODD A. , EMAD MOSSAD , PABLO MOTTA
Published: May 2006

Pediatric perioperative cardiac arrest occurs in 1.4 per 10 000 anesthetics, with an overall mortality rate of 26%. The etiology of the arrest is identifiable in the majority of these patients. We report the case of a child with a complex congenital heart defect, who sustained a cardiac arrest at induction of anesthesia, secondary to right‐ventricular dependent coronary circulation. We discuss the incidence, risks, anesthetic management and outcomes of pediatric cardiac arrest in the perioperative period especially in patients with complex congenital heart disease.
Outpatient arthroscopic knee surgery under combined local and intravenous propofol anesthesia in children and adolescents
Authors: MALDINI BRANKA , MISKULIN MLADEN
Published: May 2006

Background:  This prospective observational study included a case series of children and adolescents receiving light intravenous propofol anesthesia combined with local anesthesia (LA) for arthroscopic knee procedures. The aim was to examine the merits of anesthesia, to discuss the indications for the procedure and to analyze recovery/discharge times from the postanesthesia care unit (PACU).

Methods:  A cohort of 147 children and adolescents (ASA 1 and 2) aged 12–18 years admitted for outpatient arthroscopic knee procedures between January 2004 and May 2005 were studied. After IV access in the operating theater, the patients received propofol (10 mg·ml−1). Arthroscopy was performed approximately 15 min after injecting local anesthetic (15 ml 2% lidocaine with epinephrine 1:200 000) partly at the site of insertion of the arthroscope and other instruments (5 ml), and the rest intra‐articular. The following parameters were assessed: airway patency, propofol requirement, vital signs, procedure time, surgical operating conditions, patient satisfaction score, time to discharge, postoperative analgesia and adverse events.

Results:  Of 147 patients, 133 patients (90.5%) underwent arthroscopic knee surgery, whereas knee arthroscopy alone was performed in 14 patients (9.5%) without indication for operative treatment. The arthroscopy was well tolerated in 96.6% patients (no pain, movement or discomfort during the procedure) and only five patients required conversion to general anesthesia. Pain experienced during the injection of lidocaine was more severe than pain experienced during the surgical procedure itself (P < 0.001). The surgical evaluation of operative conditions (visualization and access to intra‐articular structures) was generally satisfactory and completely acceptable. Almost 94% (138/147) of patients said they would have the same procedure again under the same type of anesthesia. The mean propfol induction dose was 1.4 mg·kg−1 (range: 0.9–3.8) and mean propofol infusion rate 167 μg·kg−1·min−1 (range: 130–250). Movement was more likely at lower infusion rates (mean: 151 μg·kg−1·min−1). The maximal decrease in respiratory rate was 5.9 ± 5.1 br·min−1 (27.2 ± 21%) and no patient became hypoxic. Patients recovered to preoperative values at 9.8 ± 7.5 min following infusion discontinuation. There were no respiratory or cardiovascular complications. The mean stay in PACU was 47 min (range: 32–150). As many as 71% (105/147) of patients required no analgesics during the first two postoperative hours.

Conclusions:  The combination of light intravenous propofol anesthesia combined with local anesthesia for arthroscopic knee procedures provided effective sedation, good preservation of upper airway patency, rapid recovery and pain relief without major side effects and offers a good alternative to the methods already available. The majority of patients did not require postoperative analgesia.
Ascites in infants with severe sepsis – treatment with peritoneal drainage
Authors: PIOTROWSKI ANDRZEJ , SOBALA WOJCIECH , KRAJEWSKI PAWEŁ , FENDLER WOJCIECH , DABROWSKA‐WOJCIAK IWONA
Published: May 2006

Background:  Ascites in neonates and infants is usually caused by cardiac failure and urinary or biliary tract obstruction. The objective of this study was to characterize our experience with ascites as a complication of sepsis.

Methods:  We retrospectively collected and analyzed data of patients treated in the intensive care unit (ICU) of the university‐based children's hospital, in whom ascites developed during nosocomial sepsis. Ten infants admitted to the ICU in the first 2 days of life developed sepsis on the mean 31.5 (±21.9) postnatal day. Gram‐negative bacteria were the causative organism in nine cases, and Staphylococcus hemolyticus in one. Because of sepsis, reintubation and mechanical ventilation were necessary. All patients received broad spectrum antibiotics (including meropenem and ciprofloxacin), blood transfusions, catecholamines and intravenous immunoglobulin preparations. Ascites was observed on the median 13.5 day of sepsis (range 3–36), and severely compromised gas exchange. Continuous peritoneal drainage was applied by means of an intravascular catheter placed in the right lower abdominal quadrant.

Results:  The mean drained fluid volume was 44.7 (±20.4) ml·kg−1·day−1, drainage was continued for a median of 5.5 (range 1–56) day, and enabled significant reduction of ventilator settings 24 h after its implementation. No severe complications related to drainage occurred; six of 10 babies survived.

Conclusions:  Ascites can develop in infants with sepsis and cause respiratory compromise. Continuous drainage of ascitic fluid by means of an intravenous catheter is relatively safe and can improve gas exchange.