bluuebunny/crossref_metadata_2025 huggingface dataset:
Ten years of free‐air CO2 enrichment altered the mobilization of N from soil in Lolium perenne L. swards
Authors: Schneider Manuel K. , Lüscher Andreas , Richter Michael , Aeschlimann Urs , Hartwig Ueli A. , Blum Herbert , Frossard Emmanuel , Nösberger Josef
Published: December 2004

Effects of free‐air carbon dioxide enrichment (FACE, 60 Pa pCO2) on plant growth as compared with ambient pCO2 (36 Pa) were studied in swards of Lolium perenne L. (perennial ryegrass) at two levels of N fertilization (14 and 56 g m−2 a−1) from 1993 to 2002. The objectives were to determine how plant growth responded to the availability of C and N in the long term and how the supply of N to the plant from the two sources of N in the soil, soil organic matter (SOM) and mineral fertilizer, varied over time. In three field experiments, 15N‐labelled fertilizer was used to distinguish the sources of available N.

In 1993, harvestable biomass under elevated pCO2 was 7% higher than under ambient pCO2. This relative pCO2 response increased to 32% in 2002 at high N, but remained low at low N. Between 1993 and 2002, the proportions and amounts of N in harvestable biomass derived from SOM (excluding remobilized fertilizer) were, at high N, increasingly higher at elevated pCO2 than at ambient pCO2. Two factorial experiments confirmed that at high N, but not at low N, a higher proportion of N in harvestable biomass was derived from soil (including remobilized fertilizer) following 7 and 9 years of elevated pCO2, when compared with ambient pCO2.

It is suggested that N availability in the soil initially limited the pCO2 response of harvestable biomass. At high N, the limitation of plant growth decreased over time as a result of the stimulated mobilization of N from soil, especially from SOM. Consequently, harvestable biomass increasingly responded to elevated pCO2. The underlying mechanisms which contributed to the increased mobilization of N from SOM under elevated pCO2 are discussed. This study demonstrated that there are feedback mechanisms in the soil which are only revealed during long‐term field experiments. Such investigations are thus, a prerequisite for understanding the responses of ecosystems to elevated pCO2 and N supply.
Phylogeography of the Namib Desert dung beetles Scarabaeus (Pachysoma) MacLeay (Coleoptera: Scarabaeidae)
Authors: Sole Catherine L. , Scholtz Clarke H. , Bastos Armanda D. S.
Published: December 2004

Aim  Namib biogeography in many instances remains reliant on advanced and detailed systematic studies. This study attempts to combine molecular phylogenetic data, geology and palaeo‐climatic data to (i) resolve the relationships of the 13 morphological species of Scarabaeus (Pachysoma) and (ii) relate their evolution to past climatic and geological events.

Location  South Africa and Namibia.

Methods  Sequencing of a 1197 bp segment of the mitochondrial cytochrome oxidase I (COI) gene of the 13 species within Scarabaeus (Pachysoma) was undertaken. Analyses performed included Parsimony and Maximum Likelihood as well as imposing a molecular clock.

Results  The molecular phylogeny showed strong support for 11 of the 13 morphological species. The remaining two species, S. (P.) glentoni and S. (P.) hippocrates, formed a complex and could not be assigned specific status on the basis of the COI gene phylogeny. Strong support for the three species formerly classified within the genus Neopachysoma was consistently obtained. The subgenus appears to have arisen c. 2.9 Ma. Species within the subgenus arose at different times, with the common ancestor to Neopachysoma and the hippocrates complex having evolved 2.65 and 2.4 Ma, respectively. Scarabaeus (P.) denticollis, S. (P.) rotundigenus, S. (P.) rodriguesi and S. (P.) schinzi are some of the youngest species, having diverged between 2 million and 600,000 years ago.

Main conclusions  Scarabaeus (Pachysoma) is a derived monophyletic clade within the Scarabaeini. The subgenus appears to be young in comparison with the age of the Namib Desert, which dates back to the Miocene (c. 15 Ma). The psammophilous taxa are shown to disperse with their substratum and habitat, barchan dunes. Clear south/north evolutionary gradients can be seen within the species of this subgenus, which are consistent with the unidirectional wind regime. Species with a suite of mostly plesiomorphic characters have a southerly distribution while their derived psammophilous relatives have central to northern Namib distributions. Major rivers such as the Orange, Buffels and Holgat appear to be gene barriers to certain species as well as areas of origin of speciation events.
Interconnection of competence, stress and CiaR regulons inStreptococcus pneumoniae: competence triggers stationary phase autolysis ofciaRmutant cells
Authors: Dagkessamanskaia Adilia , Moscoso Miriam , Hénard Vincent , Guiral Sébastien , Overweg Karin , Reuter Mark , Martin Bernard , Wells Jerry , Claverys Jean‐Pierre
Published: December 2004

Of the 13 two‐component signal transduction systems (TCS) identified inStreptococcus pneumoniae, two, ComDE and CiaRH, are known to affect competence for natural genetic transformation.  ComD and ComE act together with thecomC‐encoded competence‐stimulating peptide (CSP) and with ComAB, the CSP‐dedicated exporter, to co‐ordinate activation of genes required for differentiation to competence. Several lines of evidence suggest that the CiaRH TCS and competence regulation are interconnected, including the observation that inactivation of the CiaR response regulator derepresses competence. However, the nature of the interconnection remains poorly understood. Interpretation of previous transcriptome analyses ofciaRmutants was complicated by competence derepression in the mutants. To circumvent this problem, we have used microarray analysis to investigate the transition from non‐competence to competence in acomC‐null wild‐type strain and itsciaRderivative after the addition of CSP. This study increased the number of known CSP‐induced genes from ≈ 47 to 105 and revealed ≈ 42 genes with reduced expression in competent cells. Induction of the CiaR regulon, as well as the entire HrcA and part of the CtsR stress response regulons, was observed in wild‐type competent cells. Enhanced induction of stress response genes was detected inciaRcompetent cells. In line with these observations, CSP was demonstrated to trigger growth arrest and stationary phase autolysis inciaRcells. Taken together, these data strongly suggest that differentiation to competence imposes a temporary stress on cells, and that the CiaRH TCS is required for the cells to exit normally from the competent state.
Repression of deoxynivalenol accumulation and expression ofTrigenes inFusarium culmorumby fungicidesin vitro
Authors: Covarelli L. , Turner A. S. , Nicholson P.
Published: December 2004

A defined medium was developed in which to monitor deoxynivalenol (DON) accumulation, fungal growth and expression of genes involved in trichothecene biosynthesis (designatedTrigenes). In liquid culture, DON accumulated shortly after maximum expression ofTri6and coincident with expression ofTri5.This was generally 96 h after inoculation. The effects of sublethal concentrations of the fungicides azoxystrobin, trifloxystrobin, kresoxim‐methyl and tebuconazole on biosynthesis of the trichothecene DON byFusarium culmorumwere studied using this medium. The strobilurin fungicides trifloxystrobin and azoxystrobin significantly reduced the accumulation of DON in culture medium at a range of concentrations. Kresoxim‐methyl, also a strobilurin, and tebuconazole, a triazole, did not significantly reduce the accumulation of DON, although levels were lower than those in nonamended cultures. Trifloxystrobin significantly reduced the accumulation of DON when added to cultures before initiation of trichothecene biosynthesis. RT‐PCR assays of the expression ofTri6andTri5genes indicated that trifloxystrobin acted by inhibiting the initiation of trichothecene biosynthesis.
Persistent Mongolian spots in Chinese adults
Authors: Leung Alexander K. C. , Kao C. Pion , Leung Alexander A. C.
Published: December 2004

Four Chinese females aged 21–35 years with Mongolian spots are reported. Two patients had the spots on their arms while the other two had the spots on their shoulders. The persistence of Mongolian spots in Chinese adults has not been previously reported.
Imiquimod is a strong inhibitor of tumor cell‐induced angiogenesis
Authors: Majewski Slawomir , Marczak Maria , Mlynarczyk Beata , Benninghoff Bernd , Jablonska Stefania
Published: December 2004

Background  Imiquimod, a potent immunomodulator, not having a direct antiproliferative activity, was found to be effective in genital and cutaneous premalignancies and malignancies. As tumor development depends on blood vessel supply, the inhibition of angiogenesis could be responsible for the antitumor activity.

Objective  To find in a murine model whether imiquimod has antiangiogenic activity and whether this activity is mediated by locally induced cytokines.

Methods  The study was performed in two cell lines: Skv human keratinocytes containing multiple integrated copies of HPV16 derived from bowenoid papulosis, and murine L1 lung sarcoma cells of Balb/c mice. The murine model of cutaneous angiogenesis was used to assess and count the new blood vessel formation. The mice were immunosuppressed by a total body X‐ray irradiation and treated with 5% or 2.5% imiquimod cream before or after induction of angiogenesis with intradermally injected tumor cell suspension. In some experiments the mice were, in addition, treated intraperitoneally with monoclonal antibodies against murine IFNα, TNFγ or IL‐18.

Results  Topical application of imiquimod on the murine skin resulted in reduction of angiogenesis (P < 0.001) induced by intradermal injection of both human and mouse tumor cells, more pronounced when 5% cream was applied on three consecutive days. Antibodies against murine IFNγ, TNFα and IL‐18 completely abolished the inhibitory effect of imiquimod on angiogenesis induced by murine L1 sacroma cells. When human Skv cells were used in angiogenesis assay, the effect of imiquimod was abolished by antibodies against IL‐18 but not against TNFα, which may be due to overproduction of TNFα by Skv cells.

Conclusions  Antiangiogenic effect of imiquimod was found to be mediated by IL‐18, probably through promoting production of INFγ, the most important inhibitor of angiogenesis.
Narrow‐band UVB for the treatment of vitiligo: an emerging effective and well‐tolerated therapy
Authors: Kanwar Amrinder Jit , Dogra Sunil , Parsad Davinder , Kumar Bhushan
Published: December 2004

Background  Vitiligo is an acquired depigmentation disorder of great cosmetic importance, affecting 1% of the general population. Photochemotherapy is the most commonly used treatment modality in extensive vitiligo, but is associated with many short‐ and long‐term side‐effects. Recently, narrow‐band ultraviolet B (NBUVB) therapy has been reported to be an effective and safe therapeutic option in patients with vitiligo. We studied the efficacy and safety of NBUVB (311 nm) therapy in Indian patients with generalized vitiligo.

Methods  Fourteen patients (six males and eight females), aged 12–56 years, with generalized vitiligo, were treated thrice weekly with NBUVB radiation therapy for a maximum period of 1 year.

Results  At the end of 1 year, 10 patients (71.4%) had marked to complete repigmentation and two each (14.3%) had moderate or mild repigmentation. Repigmentation sites showed an excellent color match. The response to therapy was correlated with the sites of involvement, duration of disease, and compliance to therapy. Adverse events were limited and transient.

Conclusion  NBUVB therapy is effective and safe in Indian patients with vitiligo. Long‐term follow up is required, however, to establish the stability of repigmentation.
Clinicopathological Features of an Equine Ovarian Teratoma
Authors: Catone G , Marino G , Mancuso R , Zanghì A
Published: December 2004

Contents

The present study describes the clinicopathological features of a mature cystic ovarian teratoma occurred in a 4 year old, cyclic, nulliparous Andalusian mare. The mass was discovered in the left ovary during a breeding soundness examination, and was hard in consistency and variously echogenic. Laparoscopy was performed to confirm the neoplastic change, followed by a unilateral laparotomic ovariectomy in the standing animal. On the cut surface the teratomatous ovary showed a large cyst filled with hair and sebaceous material and three small cysts containing mucous fluid, surrounded by solid areas where bone and cartilage could be recognized. Exceptionally, functional remnants of the ovary, including small follicles and a diestral corpus luteum were found near the tubal extremity. Histology revealed mature tissues foreign to the ovary including stratified squamous and respiratory epithelia, mucous, sebaceous and sweat glands, muscle fibres, fat and nervous tissue. The appearance of tracheal and lung architecture was occasionally observed.
Experimental and numerical rolling contact fatigue study on the 32CrMoV13 steel
Authors: COELHO L. , DIAS A. , LIEURADE H. P. , MAITOURNAM H.
Published: December 2004

The aim of this work is to study pure rolling contact fatigue in 32CrMoV13 quenching and tempering steel. The study involves both experimental and numerical work. The influence of the roughness and the residual stresses on the mechanisms and zones of cracking were studied. The results show a rapid reduction in roughness during the first minute of test but even so there will be specimen deterioration. The residual stress profile after rolling contact tests have high compression values in the surface and at a depth of approximately 240 μm, which is related with the Hertzian maximal shear stress. The numerical simulation of the Hertzian loading was used both to determine the elastic shakedown of the material and to apply a high‐cycle multiaxial fatigue criterion. The three‐dimensional finite element analysis used in the numerical calculation includes elastic‐linear kinematic hardening plastic material and allows the introduction of an initial residual stress state. Taking into account the elastoplastic load induced by the Hertz pressure, low‐cycle fatigue tests were used to characterize the mechanical properties of the material. In order to validate the numerical simulation, the results of the calculation after elastic shakedown were compared with the values measured by X‐ray diffraction after rolling contact tests. The results showed a reasonable agreement between calculated and measured stresses. The Dang Van high‐cycle multiaxial fatigue criterion showed a good relationship with the experimental findings.
Influence of grain boundaries on short crack growth behaviour of IGSCC
Authors: KAMAYA M.
Published: December 2004

Understanding short crack behaviour is essential for predicting the lifetime of light water reactor components. However, crack growth rates of short cracks are unsteady due to microstructural obstacles such as grain boundaries. On the other hand, the statistical behaviour of short cracks can be deduced from crack size distributions. Some papers have pointed out that the crack size distributions obtained by stress corrosion cracking tests showed a kink in the distribution line. This kink suggests that the short crack growth rate is slow compared with that of long cracks. And it can be thought that the slow growth rate is caused by the microstructural obstacles. This study investigated the influence of grain boundaries on the short crack growth behaviour of intergranular stress corrosion cracking. A crack growth simulation model, which considered the mechanical effects of the crack kink and bifurcation by grain boundaries, was developed. The crack depth distribution obtained by the simulation also exhibited a kink in the distribution line as seen in the experimental results. This suggests that grain boundaries play an important role in short crack growth behaviour.
On tools and toys: how children learn to act on and pretend with ‘virgin objects’
Authors: Rakoczy Hannes , Tomasello Michael , Striano Tricia
Published: December 2004

The focus of the present study was the role of cultural learning in infants’ acquisition of pretense actions with objects. In three studies, 18‐ and 24‐month‐olds (n= 64) were presented with novel objects, and either pretense or instrumental actions were demonstrated with these. When children were then allowed to act upon the objects themselves, qualitatively similar patterns of cultural (imitative) learning both of pretend and of instrumental actions were observed, suggesting that both types of actions can be acquired in similar ways through processes of cultural learning involving one or another form of collective intentionality. However, both absolute imitation rates and creativity were lower in pretense compared to instrumental actions, suggesting that the collective intentionality that constitutes pretense is especially difficult for children to comprehend. An additional analysis of children's gazes to the experimenter during their actions revealed that 24‐month‐olds looked more often to the experimenter during pretense actions than during instrumental actions – suggesting that pretense is culturally learned in a similar fashion as practical actions, but that young children understand pretense as a more inherently social, intersubjective activity.
T-Optimum Designs for Discrimination Between Two Multiresponse Dynamic Models
Authors: Uciński Dariusz , Bogacka Barbara
Published: December 2004

The paper is concerned with a problem of finding an optimum experimental design for discriminating between two rival multiresponse models. The criterion of optimality that we use is based on the sum of squares of deviations between the models and picks up the design points for which the divergence is maximum. An important part of our criterion is an additional vector of experimental conditions, which may affect the design. We give the necessary conditions for the design and the additional parameters of the experiment to be optimum, we present the algorithm for the numerical optimization procedure and we show the relevance of these methods to dynamic systems, especially to chemical kinetic models.
Effect of haloperidol on a patient with hypersexuality following frontal lobe injury
Authors: KOBAYASHI Toshiyuki
Published: December 2004

Hypersexuality is a difficult problem to manage in the elderly, especially in nursing home residents and people with dementia being cared for at home. The present study reports the case of a 70‐year‐old man who suffered from hypersexuality following a frontal lobe injury, and was successfully treated with haloperidol. There is no previously reported evidence of the efficacy of haloperidol for the treatment of hypersexuality, however, we consider that it might be worthwhile trailing this drug for this condition, as long as there are no serious adverse effects.
Intensive dialysis and blood pressure control: A review
Authors: Charra Bernard , Jean Guillaume , Chazot Charles , Hurot Jean‐Marc , Terrat Jean‐Claude , Vanel Thierry , Lorriaux Christie , Vovan Cyril
Published: December 2004

The prevalence of hypertension in hemodialysis (HD) patients has increased over the years. In the early days of maintenance HD blood pressure (BP) control was achieved in most patients. As sessions were shortened, the prevalence of hypertension increased. Yet, in principle, dialysis is able to control hypertension. Today, in programs using long HD, most patients are normotensive without antihypertensive medication. The same is true for patients on daily dialysis, but not for those on short thrice‐weekly HD. In all studies reporting BP normalization, dry weight is regularly achieved. Why the poor control of hypertension now? At first sight the shortened session duration is the culprit. This is suggested by several epidemiologic observations and strongly supported by a prospective experience of changing the HD schedule (short to long HD or conversely) in the same group of patients. Recent studies, however, using strict volume control show that BP normalization can be obtained in conventional 3 x 4 hr/week dialysis with relatively low delivered Kt/Vurea. Therefore, prolonging the dialysis time and/or increasing the dialysis dose are not required to achieve BP control. Intensive dialysis most probably normalizes BP by getting the extracellular volume and the amount of sodium in the body back to normal. It acts in conjunction with a moderate dietary sodium restriction and the use of reasonably low dialysate sodium. With this approach improved BP control can be achieved in the vast majority of HD patients.
Which Parameter Is More Influential on the Development of Arteriosclerosis in Hemodialysis Patients?
Authors: Seyrek N. , Balal M. , Karayaylali I. , Paydas S. , Aikimbaev K. , Cetiner S. , Seydaoglu G.
Published: December 2004

Arteriosclerosis is characterized by stiffening of arteries. The incremental elastic modulus (Einc) measurement is a good marker of arterial wall stiffness. Arteriosclerosis is characterized by stiffening of arteries. Metabolic, inflammatory, and hemodynamic alterations cause structural changes and vascular complications in end‐stage renal disease. The aim of the present study was to evaluate the factors that may affect the development of arteriosclerosis by measurement of Einc in hemodialysis (HD) patients. Thirty‐two patients (16 men and 16 women) on chronic HD with a mean age of 42.2 ± 19.3 (range, 15–80) were included in the study. The carotid Einc was measured to determine arteriosclerosis by high‐resolution echo‐tracking system. Einc measurement was calculated from transcutaneous measurements of carotid arterial internal diameter and wall thickness and carotid pulse pressure. Common carotid compliance (CCC) and distensibility (CCD) were determined from changes in carotid artery diameter during systole and simultaneously measured carotid pulse pressure. Serum levels of calcium (Ca), phosphorus (P), parathormone (PTH), ferritin, C‐reactive protein (CRP), predialysis systolic blood pressure (SBP), predialysis diastolic blood pressure (DBP), pulse pressure (PP), age, HD duration, CCC, and CCD were correlated with Einc in all patients. A significant positive correlation was found between Einc and age (r = 0.40, p < 0.02), SBP (r = 0.39, p < 0.02), PP (r = 0.40, p < 0.02), Ca (r = 0.43, p < 0.01), CRP (r = 0.38, p < 0.02). As expected, Einc was correlated inversely with CCD (r = −0.77, p < 0.0001). The correlation between Einc and HD duration, DBP, ferritin, P, PTH, and CCC was not significant. In conclusion, the stiffening of carotid artery in HD patients is related not only to hemodynamic changes (increased SBP and PP) but also to metabolic (increased Ca) and inflammatory (increased CRP) responses. Carotid Einc is an accepted independent risk factor for cardiovascular mortality. Because of the positive correlation between Einc and serum Ca, vitamin D and Ca‐containing P binder should be used carefully in HD patients.
Clinical Consequences of Intermittent Elevation of C‐Reactive Protein Level in Hemodialysis Patients
Authors: Sezer S. , Kulah E. , Özdemir F.N. , Tutal E. , Arat Z. , Haberal M.
Published: December 2004

The presence of persistently high C‐reactive protein (CRP) levels is well known to be associated with a state of inflammation, malnutrition, and erythropoietin resistance in hemodialysis (HD) population. Meanwhile, a substantial group of patients present with intermittent elevations of CRP levels, and its clinical consequences are unclear. We designed this study to compare the inflammatory and nutritional parameters and erythropoietin requirements in HD patients with persistent or intermittent CRP elevation and those with CRP levels in without. We included 100 HD patients [age: 48.4 ± 14.3 years; HD duration: 69.3 ± 49.0 months (minimum 12 months)]. The 6‐month retrospective clinical and laboratory data were retrieved from the patient records, and those with chronic inflammatory disease, malignancy, infectious complications, and surgery were excluded. The monthly determined CRP levels (at least 6 for each patient) were reviewed, and the patients were grouped according to their CRP levels as those with persistent (group 1), intermittent (at least one level of CRP 10 mg/L) (group 2), and those with CRP in normal ranges set by the laboratory (group 3). We compared the fibrinogen, ICAM‐1, VCAM‐1, albumin, prealbumin, normalized protein catabolic rate (nPCR), interdialytic weight gain (IDWG), and rHuEPO/kg/Hct results of the patient groups. The patient groups revealed significant differences in terms of fibrinogen (p < 0.001), albumin (p < 0.0001), prealbumin (p < 0.007), ICAM‐1 (p < 00.2) levels and nPCR (p < 0.03), IDWG (p < 0.02), and rHuEPO/kg/Hct (p < 0.03) values. Group 2 presented to be in risk of inflammation and malnutrition with a decrease in albumin levels and nPCR and presence of rHUEpo resistance when compared to patients in group 3. We conclude that, similar to HD patients with persistently high CRP levels, those with intermittent elevation of CRP must also be considered to be in a state of chronic inflammatory response associated with malnutrition and erythropoietin resistance. This signifies the importance of regulatory monitoring of CRP in HD population.
Successful Management of Valproate Overdose by a Combination of Extracorporeal Therapies
Authors: Yalamanchili P. , Al Aly Z. , Gonzalez E.
Published: December 2004

Valproic acid toxicity is not infrequent and is difficult to treat, as there is no specific antidote. In the past, this drug was considered unremovable by extracorporeal methods because of the highly protein bound state (90–95%). However, recent reports suggest that the toxicokinetics of valproate vary considerably from the pharmacokinetics at therapeutic levels, and at higher concentrations protein‐binding sites become saturated. The drug's relatively low molecular weight (144 Da), small volume of distribution (0.13–0.23 L/kg), and saturable protein binding render it potentially amenable to extracorporeal removal, but published experience is scant and there are only a few reported instances in which patients were successfully treated with extracorporeal methods. Here we report the case of a patient with serious valproate toxicity treated with simultaneous “in series” hemodialysis and hemoperfusion followed by continuous veno‐venous hemodiafiltration. A 35‐year‐old homeless male presented to the emergency department after ingesting 120 pills of valproic acid. Initial valproic acid level was 59 µg/mL. Urine drug screen was negative and serum chemistries including LFTs were normal. He was treated with activated charcoal and admitted to the intensive care unit. 4 h later, he developed respiratory failure and became hemodynamically unstable. He was intubated and successfully resuscitated. Subsequently, the valproic acid level was found to be 553 µg/mL and a decision was made to employ extracorporeal methods for drug removal. “In series” hemodialysis and hemoperfusion were done for 4 h and simultaneous blood samples for measurement of valproic acid levels were obtained as blood entered the hemoperfusion column (arterial) and as it exited the hemodialysis membrane (venous). Extraction ratio, whole blood, and plasma clearances were calculated and they compared substantially with the published data. The above measures decreased valproate levels from 572.6 (pre‐dialysis level) to 203.2 µg/mL. This was followed by continuous veno‐venous hemodiafiltration for 18 h, which sustained the drug removal and prevented significant post‐dialytic rebound. This is the first reported instance in which these three methods were administered together successfully in the management of valproic acid toxicity.
Routine Ultrasound Studies of the Vascular Access in a Dialysis Center: A Review
Authors: Cairoli O.M.
Published: December 2004

The establishment and maintenance of vascular access in end‐stage renal disease provides a greater challenge. Adequate dialytic therapy requires reliable, long‐term access to the blood circulation. Vascular access remains the Achilles' heel of chronic hemodialysis; complications are costly for the patient and society. Vascular access failure is the most frequent cause of hospitalization for patients with chronic renal disease. The general goal was to prevent thrombectomies, thus preventing hospitalizations and reducing cost, and most importantly, saving the patient's access and increasing the survival rate of the graft or fistula. A protocol to evaluate the vascular accesses at the dialysis centers where our patients are dialyzing was implemented. The patients are evaluated before their dialysis treatments, every 2 months if they have a graft and every other visit (4 months) if they have a fistula. New patients will be evaluated every visit by the vascular technician. The protocol (US Vascular Access Protocol) also has attention parameters and depth considerations. The attention parameters refers to blood flows and reductions in size. For example, for a fistula, a normal flow will be 400 mL/min or above, an alert value will be 390 mL/min or below, and a reduction in size of 1.9 mm or below will also be an alert value for the fistula (Table I). Depth considerations relate to how deep the access is, for example 2–3 mm is ideal to cannulate, 8 mm and above make cannulation impossible (Table II). Patients with vascular problems are then referred to the vascular surgeon or, as mostly, are referred to interventional radiology. We have found that these Doppler reports are very accurate, and after almost a year, doing these tests at the dialysis center, many accesses have been saved, and dialysis quality has improved in those patients by resolving issues causing re‐circulation, stenosis, etc. In conclusion, we need to continue evaluating this program, but the preliminary reports show that by using the Doppler studies prophylactically, dialysis accesses can be saved or their use prolonged, thereby saving costs and reducing the need for future sites for the patient. And, in some cases, improving dialysis adequacy.

Attention parameters

Normal values
Alert values

Fistula

Access volume flow (mL/min)
≥400
 0–390

Reductions (mm)
≥2.0
 0–1.9

Graft

Access volume flow (mL/min)
≥600
 0–590

Reductions (%)
0–49
50–100

Depth considerations

2–3 mm
Ideal and easy to cannulate

4–5 mm
Is acceptable

6–7 mm
Increases difficulty of cannulation and increases vessel wall damage

≥8 mm
Makes cannulation difficult‐to‐impossible, causes significant wall damage and infiltrations, requires longer cannula
Inflamation and EPO Therapy in HD Patients
Authors: Yonova D. , Dobrev S. , Stanchev I. , Papazov V. , Kojcheva N. , Velizatova M. , Hadjiev S.
Published: December 2004

Some authors suggest that inflammation can be one of the reasons of erythropoietin (EPO) resistance. The purpose of the study was to follow‐up some laboratory markers of inflammation in 21 dialysis patients, all treated with adequate anaemia doses EPO, divided in 2 groups: first one adequately responding to EPO treatment (with Hb higher than 9 g/L) and second one resistant to it (with Hb lower than 9 g/L). Some acute phase proteins and markers of inflammation were measured as follow: C‐reactive protein (CRP), α1‐AGT, α1‐antitrypsine, and haptoglobine (HP), as some anti‐acute phase proteins, transferrin (TF). WBC count, some enzymes: ASAT, ALAT, and substrates: urea, creatinine, albumins (Albs), lipid profile, glucose, phosphate, iron, electrolytes, and parathyroid hormone were tested as well. The study found significant higher CRP, HP, Tg, P, and Alb in the second group than in the first. TF was lower in all patients, which may be connected to the chronic inflammatory status (uremia), and there was no iron deficit or severe parathyroid hyperfunction to be convinced for EPO resistance. The study suggests that EPO resistance may be related to some inflammatory factors and treatment of the inflammation possibly will overcome the problem.
Hemodialysis Central Venous Catheter‐Related Bacteremia: Time to Onset
Authors: Troidle L. , Juergensen P. , Cantey L. , Eisen T. , Finkelstein F.O.
Published: December 2004

Bacteremia (B) is a well‐known complication of an indwelling central venous catheter (CVC). Although prophylactic measures such as topical and catheter lock antibiotics have been demonstrated to decrease the risk of B in hemodialysis (HD) in patients with a CVC, there are concerns about the development of resistance to these agents when used for long periods of time.

Objective:  We wondered if we could limit the use of these agents by identifying the period when B was most common after CVC placement.

Method: We prospectively noted all patients with a CVC who developed B in any of our 3 units in CT, U.S.A.; 62 episodes of B occurred between 1/1/03 and 9/18/03. 35% of all of the HD patients had a CVC for access during the study period.

Results: Staphylococcus aureus accounted for 22 (35.5%) episodes; Gram‐negative organisms for 21 (33.8%) and other staphylococcal species for 14 (22.6%). The other 3 episodes were other Gram‐positive organisms and 6 patients developed B with more than 1 organism. 3 (4.8%) patients expired while being treated for the B. The average time to onset of B was 96 ± 98 CVC days with a range of 1–365 days. There was no difference in time to onset based on organism. 43.5% of the episodes of B occurred less than 60 days after the CVC was inserted, but 27.4% occurred greater than 100 days after CVC insertion.

Conclusion:  The time to onset of CVC‐related B was variable among the patients developing B in this study. Preventative strategies aimed at reducing the risk of B in patients with a CVC must be used for the life of the CVC.
The Influence of C‐Hepatitis on C‐Reactive Protein in a Cohort of Brazilian Hemodialysis Patients
Authors: Nascimento M.M. , Bruchfeld A. , Suliman M.E. , Hayashi S.Y. , Pecoits‐Filho R. , Manfro R.C. , Pachaly M.A. , Renner L. , Stenvinkel P. , Riella M.C. , Lindholm B.
Published: December 2004

Background:  The aim of this study was to investigate the influence of HCV on two markers of systemic inflammation, serum CRP, and interleukin‐6 (IL‐6) in HD patients.

Methods:  The study included 118 HD patients (47% males, age 47 ± 13 years, 9% diabetics) who were treated by on standard HD for at least 6 months. The patients were divided in two groups, depending on the presence (HCV+) or absence (HCV–) of serum antibodies against HCV. Serum albumin (S‐Alb), plasma high sensitivity CRP (hsCRP), IL‐6, and alanine aminotransferase (ALT) were measured, and the values were compared with 22 healthy controls.

Results:  The median of hsCRP, IL‐6, and the hsCRP/IL‐6 ratio were: 3.5 vs. 2.1 mg/L, p < 0.05; 4.3 vs. 0.9 pg/mL, p < 0.0001; and 0.8 vs. 2.7 pg/mL, p < 0.0001 for patients and controls, respectively. Age, gender, S‐Alb, IL‐6, and hsCRP did not differ between the HCV+ and HCV– patients. However, HCV+ patients had higher ALT (29 ± 21 vs. 21 ± 25 UI/L) and had been a longer time on HD (6.1 ± 3.0 vs. 4.0 ± 2.0 years) (p < 0.0001), respectively. Moreover, HCV+ patients had a significantly lower median hsCRP/IL‐6 ratio (0.7 vs. 0.9; p < 0.05) as compared to the HCV group.

Conclusion:  The finding that the hsCRP/IL‐6 ratio was lower in HCV+ patients than in HCV– patients suggests that hsCRP may be a less useful marker of inflammation in HCV+ patients and that a different cut‐off value for hsCRP may be required to define inflammation in HD patients.
The Safety of Intravenous Ferric Gluconate Self Administered During Routine Home Hemodialysis
Authors: Utley M. , Grundy A. , Gehr T.
Published: December 2004

Home hemodialysis (HHD) patients are often inconvenienced when intravenous iron preparations are administered. Formerly, these patients received their medication in the clinic on an off‐dialysis day or during in‐center hemodialysis (HD). For the last 2 years, 5 patients in our HHD program have been receiving intravenous ferric gluconate during their routine HD session.

Procedure:  All patients were trained in the proper administration of ferric gluconate in‐center. No test dose was administered. Ferric gluconate was infused via the heparin infusion pump on their HD machine at a rate of 31.25 mg/h. Doses were of either 62.5 mg or 125 mg per session. K/DOQI guidelines for intravenous iron use were adhered to. TSATs greater than 25%, ferritin greater than 100 ng/mL and less than 800 ng/mL, and hemoglobin between 11 and 12 g% were the goals of therapy. Both loading doses (8 doses during sequential HD sessions) and maintenance doses every week or every other week were employed.

Results:  Over the last 2 years, 223 doses were administered at home. No serious reactions occurred during the course of therapy. One patient experienced minor nausea and vomiting during one dose, which was thought to be possibly related to the iron infusion. This patient subsequently received ferric gluconate again without difficulty.

Conclusion:  Ferric gluconate can be safely administered at home during HHD.
6 Years of Experience with Nightly Home Hemodialysis Access
Authors: Lockridge R.s. , Spencer M.o. , Craft V.w. , Pipkin M.f. , Campbell D.l.
Published: December 2004

Lynchburg Nephrology Dialysis Inc. started its nightly home hemodialysis (NHHD) program in September 1997.

Purpose of study:  To evaluate episodes of exit site infections, catheter sepsis, safety, and longevity of accesses for patients doing NHHD.

Methods:  If IJ catheter was chosen, patient was started on Coumadin 2 mg/day when catheter was placed. If catheter malfunctioned, it was locked with a thrombolytic agent and Coumadin was adjusted to meet a goal INR of 1.5–2.25. If the problem persisted, the catheter was exchanged. For catheters, the B‐D InterLink device was used to prevent air emboli and infection, and a locking device was used to prevent disconnects. If AV fistula was used, 4 buttonholes were established using 16 gauge needles. If AV graft was used, patients were taught the ladder cannulation technique using 16 gauge needles.

Results:  As of September 1, 2003, 45 patients have completed training and have performed 27,063 treatments at home. Total catheter time at home was 930 months. Total AV fistula and AV graft time at home was 190 and 20 months, respectively. Upon completion of training, 34 patients were using tunneled IJ catheters, 10 using AV fistulas, and 1 using an AV graft. The IJ catheter exit site and sepsis infection rate was 0.35 and 0.49 episodes/1000 patient days, respectively. Average catheter life was 8.5 months with the longest 66.7 months and the shortest 0.2 months. The AV fistula and graft exit site and sepsis infection rates were 0.16 and 0 episodes/1000 patient days, respectively. Catheter complications included 1 episode of disconnect due to patient's failure to use locking device, 1 episode of central stenosis, and 1 episode of intracranial hemorrhage, due to prolonged INR, with resolution of symptoms.

Conclusion:  Data support that tunneled IJ catheters, AV fistulas, and AV grafts were effective and safe permanent accesses for patients on NHHD.
Regional Anticoagulation with Sodium Citrate in Pediatric Patients on Intermittent Hemodialysis Therapy with Bleeding Risks
Authors: Kreuzer M. , Vester U. , Hörning A. , Bonzel K‐E. , Hoyer P.F.
Published: December 2004

Heparin‐free anticoagulation in hemodialysis (HD) is advocated for patients with clotting abnormalities and risk of bleeding.

Objective:  First publication on regional citrate anticoagulation (RCA) in children. RCA is free from systemic effects, guarantees excellent dialyzer life, but requires careful monitoring.

Methods:  We report on 3 patients treated by intermittent RCA HD (4 h each, high‐flux dialyzer F40, Fresenius): (1) 17‐year‐old boy (renal transplant failure, access via cubital Cimino fistula) after hypertensive intra‐cerebral hemorrhage (2 sessions); (2) 13‐year‐old girl (hemolytic uremic syndrome, access via jugular vein Shaldon catheter) after abdominal surgery and bleeding (8 sessions); and (3) 7‐year‐old boy (hyperoxaluria, access via PermCath® jugular vein catheter) after renal transplant biopsy (3 sessions). Sodium citrate 30% was infused into the extra corporeal circuit (blood flow 150 mL/min) before dialyzer (initial flow 30 mL/min) and calcium gluconate 10% for antidote into venous line near of catheter or fistula (initial flow 40 mL/min). Post‐dialyzer extracorporeal serum Ca++ (aim < 0.3 mmol/L) and pre‐dialyzer intra‐corporeal Ca++ (aim > 0.9) were measured for every 30 min. Serum Na+, K+, base excess (BE), blood flow, blood pressure, heart rate, and blood out‐flow and in‐flow pressure were also monitored.

Results:  For adequate RCA (mean extracorporeal serum Ca++ 0.24 ± 0.04 mmol/L), a mean citrate flow of 36.1 ± 5.9 mL/h and a mean calcium substitution rate of 40.8 ± 3.4 mL/h were needed. Intra‐corporeal Ca++ was kept at 1.10 ± 0.07 mmol/L. Extracorporeal activated clotting time (ACT) was 194 ± 41 and intra‐corporeal ACT 90 ± 12 sec. Serum Na+, K+, and BE during HD were 138 ± 2, 3.5 ± 0.3, and −0.6 ± 1.1 mmol/L, respectively. Mean arterial blood pressures of patients 1–3 were 117 ± 5, 103 ± 5, and 102 ± 6 mmHg. All patients were stable and without any bleeding during HD. The only adverse event was 1 episode of hypocalcemia (Ca++ < 0.6 mmol/L) cured by stopping dialysis.

Conclusions:  Local anticoagulation with sodium citrate during intermittent HD can be applied safely in children and adolescents.
Effective Adherence Contest to Improve Albumin, Phosphorus, and Fluid Levels in Pediatric Hemodialysis Unit
Authors: Fain A. , McPhail K. , Hines. D.
Published: December 2004

Low serum albumin, high serum phosphorus, and fluid overload are common issues in dialysis patients. This can be attributed to many causes such as inadequate understanding and lack of accountability in the patients' care. These abnormal levels contribute to increased medical complications and increased mortality.

Objective:  (i) Improve patient education of albumin, phosphorus, and fluid maintenance. (ii) Improve patients' albumin, phosphorus, and fluid levels by 25 percent.

Methods:  A baseline level was collected on all patients by averaging last 3 laboratory findings. All patients were educated recognizing several different learning styles. Educational posters were displayed, one‐on‐one education was provided, as well as educational games on the role of albumin, phosphorus, and fluid. Patients were also educated on the role of diet in these levels. Positive reinforcement, peer pressure, and intensive team approach were used through the 8‐week incentive contest. Feedback on progress was provided in written and verbal format. Prizes were awarded for best shift levels and shift with most improvements.

Results:  Levels measured at the end of the educational period and contest showed a 71% improvement in albumin levels, 52% improvement in phosphorus levels, and a 42% improvement in fluid levels.

Conclusion:  Significant improvements found in all areas are attributed to three factors: education, consistent, individual, intensive attention, and incentives. Peer pressure was found not to be as effective but that individual tracking for incentives may be more effective if done ongoing. Our follow up several months later found a slight decrease in improvements, and we recognize a need for an ongoing intervention. Yet, we found an overall improvement of level of understanding and commitment to their overall health.
Impact of Ischemic Heart Disease on Early Access Failure in Nondiabetic Hemodialysis Patients
Authors: Kim Y.o. , Shin S.j. , Shin Y.s. , Lee S.h. , Yoon S.a. , Kim Y.s. , Chang Y.s. , Bang B.k.
Published: December 2004

Atherosclerotic lesion of coronary artery frequently accompanies intimal hyperplasia of radial artery. We have reported that the lesion of radial artery (intimal hyperplasia) in hemodialysis (HD) patients is associated with early access failure (EAF) as well as ischemic heart disease (IHD) (Am J Kidney Dis. 2003; 41: 422–428).

Objective:  This study was designed to determine the impact of IHD on the EAF in nondiabetic HD patients.

Methods:  This study enrolled 125 nondiabetic HD patients who received radiocephalic arteriovenous fistula operation for the first time. We evaluated IHD before the operation through clinical symptoms and electrocardiography and then investigated EAF within 1 year after the operation. We analyzed the access patency rates between the patients with and without IHD, using Kaplan–Meier method and log‐rank test. Multiple regression analysis was performed to identify independent risk factors of the EAF.

Results:  The mean age of the patients was 48 ± 14 years, and the number of females was 54 (43.2%). Of the total 125 patients, 19 patients (15.4%) had IHD before the operation. The EAF developed in 23 patients (18.4%) within 1 years after the operation. The access patency rate in the patients with IHD was lower than that in the patients without IHD (39.7 vs. 88.3%, p < 0.001). IHD and old age were independent risk factors of the EAF in nondiabetic HD patients. But sex, smoking history, hypertension, and the levels of hemoglobin, serum creatinine, albumin, and total cholesterol checked before the operation were not associated with the EAF.

Conclusion:  This study suggests that IHD is closely associated with EAF in nondiabetic HD patients.
Thrombotic Events and Pentosidine in Hemodialysis
Authors: Schwing W.D. , Erhard P. , Holloman C. , Weigel K. , Blankshaen S. , Anderson J. , Siegel C. , Seaman D. , Valente J. , DeOreo P. , Weiss M.F.
Published: December 2004

Poorly functioning dialysis access, whether graft or AV fistula, is a contributor to decreased efficiency of dialysis. Thrombosis results in the need for surgery and increases patient suffering.

Objectives:  To determine whether an advanced glycation end product (AGE), pentosidine, might serve as a marker of disease activity and thrombosis of dialysis access. These results were obtained during the blinded phase of a study to evaluate the efficacy of the antioxidant vitamin E in preventing vascular access thrombotic events.

Methods:  Twenty‐six patients had blood drawn and access flow evaluated initially and at intervals for up to 1.5 years. In the study design, participants received either 800 IU vitamin E daily by mouth or identical placebo capsules. Blood plasma was examined to determine pentosidine content at baseline and every 3 m. Patients with an access flow of <800 mL/min were referred to a surgeon for evaluation. Access flow was evaluated by using the transonic flow meter and the saline release method. When sequential double dialyzers were used, saline injection method was applied post dialyzers, but before the venous drip chamber.

Results:  Mean initial level of pentosidine before the administration of vitamin E was 20.22 pmol/mg (range 5.04–59.62 pmol/mg). During the study period, 5 patients had procedures related to thrombosis performed on their accesses. Blood drawn before the thrombotic event showed an increase above baseline of 6.87 ± 15.47 (range −5.9 to +33.7 pmol/mg). Patients without events showed a mean decrease of 9.7 ± 12.24 pmol/mg pentosidine (p < 0.02).

Conclusion:  An increase in levels of pentosidine was associated with clotting of hemodialysis access. This change may reflect the effects of oxidative stress and/or thrombus formation. As these data are gathered from an ongoing double‐blinded study, the effect of vitamin E on thrombus formation and pentosidine levels has not yet been ascertained.