bluuebunny/crossref_metadata_2025 huggingface dataset:
Trisomy 7 and 17 mark papillary renal cell tumours irrespectively of variation of the phenotype
Authors: Balint I , Szponar A , Jauch A , Kovacs G
Published: June 2009

Background:

Papillary renal cell tumours (RCTs) have been described as a genetic entity. Recently, papillary RCTs have been divided into small (type 1) and large (type 2) cell tumours. Subsequent DNA analyses have resulted in controversial data regarding putative genetic changes marking type 1 and type 2 tumours.

Aim:

The aim of this study was to improve the original description that papillary RCT is a genetic entity regardless of the phenotypic variation.

Methods:

DNA from 163 papillary RCTs, including 82 multiplex tumours from eight hereditary cases, was analysed for copy number changes by chromosomal comparative genomic hybridisation (CGH) and/or for allelic changes at chromosomes 7 and 17 by microsatellite analysis. The results of the genetic analysis were compared with the cytological characteristics of the tumours.

Results:

The results showed alterations of chromosomes 7 and 17 at similar frequencies in papillary RCTs with characteristics ranging from small to large cell, nuclear grade 1 to 3, and 3 mm to 16 cm diameter.

Conclusion:

Trisomies of chromosomes 7 and 17 are specific genetic alterations in papillary RCTs irrespective of their size, grade and cellular differentiation.
Solution charts for the consolidation of circular footings embedded in a finite stratum
Authors: Zhang Wen-Wei , Zhu Guofu , Wang Ren , Meng Qingshan
Published: June 2009

This technical note used the finite element method to investigate the consolidation behaviour of circular footings embedded in a finite stratum based on Biot’s consolidation theory. The influence of three factors on the degree of consolidation settlement was examined: (1) the ratio of the buried depth to the thickness of the stratum, (2) the ratio of the footing radius to the thickness of the stratum, and (3) the Poisson’s ratio of the soil skeleton. Based on the results of analysis, new normalized time factors are suggested. It is shown that the degree of consolidation exhibits very good normalized behaviour using the time factors. The authors also present solution charts for determining the degree of consolidation settlement of circular footings embedded in a finite stratum. These charts can provide engineers with a quick answer to the design issues. The maximum error caused by using the solution charts is within 3%.
Lower and upper limits of layered-soil strength
Authors: Guo Peijun , Stolle Dieter F.E.
Published: June 2009

This paper presents an approach to determine the lower and upper limits for failure criteria of layered soils that have periodic structure. Particular functional forms are proposed for multilayered soil samples consisting of two periodic constituents. It was found that the upper limit of failure criterion is uniquely determined by volume fraction and strength characteristics of each constituent, whereas the lower limit is affected by the interaction between constituent layers, which in turn depends on the deformation characteristics. An important observation is that an upper limit can only be reached for certain stress paths. The directional dependency of layered soil strength was examined within the context of the proposed approach.
Studies on the behaviour of screw piles by the finite element method
Authors: Kurian Nainan P. , Shah Syed J.
Published: June 2009

A circular pile with helical blades is an old type of foundation, which has staged a comeback recently and is being used in a variety of situations. Most of the research on helical screw piles has been experimental or theoretical with the help of simplifying assumptions. The method of design adopted so far treats this pile as an annular plate, disregarding the intricacies of the geometry of the helix. It is only the versatility of the finite element method that can take into account the actual geometry of a spatial structure such as the helical blade at a microlevel. This is perhaps the first attempt at such an analysis to study the response of the helical screw pile within the elastic and nonlinear ranges. While the pile is linearly elastic, soil is considered both as a linear elastic medium and as an elastic–plastic medium following the Drucker–Prager constitutive model. Cases of smooth contact and frictional contact between soil and screw pile are also considered. Screw piles are studied under compressive, tensile, and lateral loading conditions. Moreover, their performance is compared with that of prismatic piles. A parametric study has also been attempted on some key geometrical features of the screw pile.
Protocol for the assessment of unsaturated soil properties in geotechnical engineering practice
Authors: Fredlund Delwyn G. , Houston Sandra L.
Published: June 2009

The implementation of unsaturated soil mechanics into routine geotechnical engineering practice requires an evaluation of methodologies that may be used for the assessment of “unsaturated soil property functions.” Guidelines and recommendations need to be provided to practicing engineers. The guidelines need to take the form of “engineering protocols” that define acceptable standards for engineering practice. “Engineering protocols” for unsaturated soils engineering practice can be divided into “preliminary design” protocols and “final design” protocols. Both design levels involve the use of a variety of estimation procedures that have been proposed for various classes of geotechnical problems (e.g., unsaturated flow, shear strength, volume change, and distortion). The hierarchy in methodologies is based mainly on the costs and risks associated with a particular engineering project. In this paper, “hierarchical levels” are suggested that take into consideration the cost of various direct and indirect methodologies for the determination of unsaturated soil properties. Recommendations and suggestions are provided for methods for the determination and use of the soil-water characteristic curves (SWCC) and consequently, for the computation of unsaturated soil property functions (USPFs). Primary attention is given to estimation procedures best known to the authors and most appropriate for geotechnical engineering practice.
Measured deformations and calculated stresses of high-density polyethylene pipes under very deep burial
Authors: Krushelnitzky R. P. , Brachman R. W.I.
Published: June 2009

The physical response of 100 mm diameter high-density polyethylene, plane-wall pipes is examined when subjected to vertical pressures as large as 3000 kPa. These pressures greatly exceed typical pressures for conventional sewer and culvert applications, but may be encountered in special applications, such as very deep tailing dams, heap-leach mining pads, and landfills. Results are presented for two different thicknesses of pipe with a diameter to thickness ratio, DR, equal to 11 and 26. Four different backfill materials are investigated, including poorly graded sand, well-graded gravel, and two poorly graded gravels. The pipes were observed to deform into essentially stable elliptical shapes with no evidence of buckling. Maximum deflections of the DR 11 pipes ranged from 10% of the initial pipe diameter at 3000 kPa for compacted poorly graded sand backfill to 20% at 2400 kPa for uncompacted angular poorly graded gravel backfill. Results from numerical analyses are also presented to provide insights into the soil and pipe response at very large pressures. Geometrically nonlinear finite element analysis featuring a viscoplastic pipe model and linear elastic–plastic model for the backfill was able to capture the measured deflections. Pipe stresses calculated from the analyses showed tensile stresses below the allowable long-term limits, but there was short-term compressive yield.
Soil improvement using electroosmosis with the injection of chemical solutions: field tests
Authors: Ou Chang-Yu , Chien Shao-Chi , Chang Hsuan-Hsiang
Published: June 2009

Previous laboratory studies have shown that the injection of a calcium chloride solution followed by the injection of a sodium silicate solution during electroosmosis is effective in strengthening soft silty clay. Very stiff cemented soil near the anodes is formed after the treatment. This paper presents the effectiveness of the process in the field. Nine electrodes were installed using two grid arrangements with electrode spacings of 2.0 m × 2.5 m and 2.0 m × 5.0 m. The test procedure is similar to those employed in the laboratory. Test results show that the soil surrounding the anodes (within a diameter of 50–60 cm) became very stiff and cemented due to the effect of cementation between the two chemical solutions and soil particles under the electric field. Except for the areas of stiff cemented soil, the undrained shear strength of the soil between electrodes was increased substantially. Polarity reversal after normal polarity did not produce favorable improvement effects in terms of undrained shear strength of the soil and treatment time.
Capacity of shallow foundations on saturated cohesionless soils under combined loading
Authors: Yilmaz M. Tolga , Bakir B. Sadik
Published: June 2009

Under seismically induced loading, shallow foundations commonly fail by overturning on saturated soils. While the excess pore pressures may have fully dissipated following construction, undrained conditions are typically presumed in the assessment of seismic capacity in conventional applications due to the high rates of loading induced during an earthquake. Undrained strength, however, can be critically dependent on the history of loading and significantly heterogeneous and anisotropic around a foundation. The finite element method is utilized in this study for a proper assessment of the impact of these factors on the overturning moment capacity of surficial foundations on saturated soils, with specific emphasis on failure under seismic loading. Uplift capability has been incorporated into the models and analyses have been conducted for different drainage conditions. Based on the analyses results and comparisons with analytical formulae, it is concluded that the assumption of homogeneous soil strength as well as the disregard of stress path followed can lead to significant overestimation of the overturning moment capacity. The proposed improved approach comprises calculation of the overturning moment capacity based on drained soil behavior and subsequent application of an undrained behavior reduction factor (URF) compatible with the representative pore-pressure parameter A.
Effet des cations extra-réseau de la zéolithe Y sur l’activité catalytique du palladium dans la réaction de combustion du méthane
Authors: Zina Mongia Saïd , Bassalah Lobna , Ghorbel Abdelhamid
Published: June 2009

Alkali and alkaline earth metal cations were introduced into zeolite to explore their influence on the activity of supported palladium in the total combustion of methane and to study how the acido-basic properties of the support affected the structure and the oxidation state of Pd. The results show that all samples exhibit a slight activation with time. Moreover, at temperatures below 430 °C, PdLiNaY seems to be the most active catalyst, while PdHY is the most active sample at higher temperatures. Except for PdHY, all Pd catalysts lead to an activation energy (Ea) value in the range of 79–97 kJ mol–1.
A simple and facile synthesis of amidoalkyl naphthols catalyzed by Yb(OTf)3 in ionic liquids
Authors: Kumar Anil , Rao M. Sudershan , Ahmad Israr , Khungar Bharti
Published: June 2009

An improved, simple, and facile synthesis of amidoalkyl naphthols by employing three-component one-pot condensation reaction of β-naphthol, aromatic aldehydes, and amides in ionic liquids using ytterbium triflate as a mild Lewis acid catalyst is described. Advantageously, amidoalkyl naphthols were obtained in high yield under eco-friendly, economical, and non-corrosive conditions, and the catalyst was recycled.
Cerium(IV) sulfate catalyzed one-pot three-component diastereo selective synthesis of 4-amidotetrahydropyrans
Authors: Selvam Nagarajan Panneer , Perumal Paramasivan T.
Published: June 2009

A convenient and diastereoselective one-pot synthesis of cis-4-amidotetrahydropyrans is described. This simple protocol involves Prins cyclization of homoallylic alcohol and aldehydes, followed by Ritter reaction of acetonitrile leading to the formation of cis-4-acetamidopyrans in good yields.
Medical Discourse
Authors: Wilce James M.
Published: June 2009

Discourse plays an important role in medicine, and medical discourse in the broadest sense (discourse in and about healing, curing, or therapy; expressions of suffering; and relevant language ideologies) has profound anthropological significance. As modes of social action, writing and speaking help constitute medical institutions, curative practices, and relations of authority in and beyond particular healing encounters. This review describes cultural variation in medical discourse and variation across genres and registers. It then surveys two approaches to analyzing medical discourse: conversation analysis (CA) and discourse studies echoing Foucault's work, attempting to spur dialogue between them. Such dialogue could be fruitful because, despite hesitancy to invoke macrosocial variables, conversation analysts as well as Foucaultian discourse analysts have reflected on medical authority. Finally, the article reviews recent attempts to contextualize closely analyzed interactions—written exchanges as well as face-to-face clinical encounters—vis-à-vis the global circulation of linguistic forms and ideologies.
State Emergence in Early China
Authors: Liu Li
Published: June 2009

Questions relating to state emergence in China are often intertwined with the origins of early dynasties. This subject involves many disciplines, including archaeology, history, and anthropology, and scholars from these fields often employ different definitions for states/civilization, use various approaches, and address diverse issues. This article intends to provide an overview of major archaeological findings, approaches, interpretations, and debates on certain issues. Controversial questions include whether some of late Neolithic polities can be considered early states, and whether ancient textual accounts can be used to guide archaeological interpretations. It may not be possible in the near future to alter the historiographically determined approach, which pervades Chinese archaeology, but social-archaeology methods for investigating the political-economic system on regional and interregional scales have proven productive.
Small intestinal efflux mediated by MRP2 and BCRP shifts sulfasalazine intestinal permeability from high to low, enabling its colonic targeting
Authors: Dahan Arik , Amidon Gordon L.
Published: June 2009

Sulfasalazine is characterized by low intestinal absorption, which essentially enables its colonic targeting and therapeutic action. The mechanisms behind this low absorption have not yet been elucidated. The purpose of this study was to investigate the role of efflux transporters in the intestinal absorption of sulfasalazine as a potential mechanism for its low small-intestinal absorption and colonic targeting following oral administration. The effects of P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP) inhibitors on sulfasalazine bidirectional permeability were studied across Caco-2 cell monolayers, including dose-response analysis. Sulfasalazine in vivo permeability was then investigated in the rat jejunum by single-pass perfusion, in the presence vs. absence of inhibitors. Sulfasalazine exhibited 19-fold higher basolateral-to-apical (BL-AP) than apical-to-basolateral (AP-BL) Caco-2 permeability, indicative of net mucosal secretion. MRP2 inhibitors (MK-571 and indomethacin) and BCRP inhibitors [fumitremorgin C (FTC) and pantoprazole] significantly increased AP-BL and decreased BL-AP sulfasalazine Caco-2 transport in a concentration-dependent manner. No effect was observed with the P-gp inhibitors verapamil and quinidine. The IC50values of the specific MRP2 and BCRP inhibitors MK-571 and FTC on sulfasalazine secretion were 21.5 and 2.0 μM, respectively. Simultaneous inhibition of MRP2 and BCRP completely abolished sulfasalazine Caco-2 efflux. Without inhibitors, sulfasalazine displayed low (vs. metoprolol) in vivo intestinal permeability in the rat model. MK-571 or FTC significantly increased sulfasalazine permeability, bringing it to the low-high permeability boundary. With both MK-571 and FTC present, sulfasalazine displayed high permeability. In conclusion, efflux transport mediated by MRP2 and BCRP, but not P-gp, shifts sulfasalazine permeability from high to low, thereby enabling its colonic targeting and therapeutic action. To our knowledge, this is the first demonstration of intestinal efflux acting in favor of oral drug delivery.
Ca2+-independent contraction of longitudinal ileal smooth muscle is potentiated by a zipper-interacting protein kinase pseudosubstrate peptide
Authors: Ihara Eikichi , Moffat Lori , Borman Meredith A. , Amon Jennifer E. , Walsh Michael P. , MacDonald Justin A.
Published: June 2009

As a regulator of smooth muscle contraction, zipper-interacting protein kinase (ZIPK) can directly phosphorylate the myosin regulatory light chains (LC20) and produce contractile force. Synthetic peptides (SM-1 and AV25) derived from the autoinhibitory region of smooth muscle myosin light chain kinase can inhibit ZIPK activity in vitro. Paradoxically, treatment of Triton-skinned ileal smooth muscle strips with AV25, but not SM-1, potentiated Ca2+-independent, microcystin- and ZIPK-induced contractions. The AV25-induced potentiation was limited to ileal and colonic smooth muscles and was not observed in rat caudal artery. Thus the potentiation of Ca2+-independent contractions by AV25 appeared to be mediated by a mechanism unique to intestinal smooth muscle. AV25 treatment elicited increased phosphorylation of LC20(both Ser-19 and Thr-18) and myosin phosphatase-targeting subunit (MYPT1, inhibitory Thr-697 site), suggesting involvement of a Ca2+-independent LC20kinase with coincident inhibition of myosin phosphatase. The phosphorylation of the inhibitor of myosin phosphatase, CPI-17, was not affected. The AV25-induced potentiation was abolished by pretreatment with staurosporine, a broad-specificity kinase inhibitor, but specific inhibitors of Rho-associated kinase, PKC, and MAPK pathways had no effect. When a dominant-negative ZIPK [kinase-dead ZIPK(1–320)-D161A] was added to skinned ileal smooth muscle, the potentiation of microcystin-induced contraction by AV25 was blocked. Furthermore, pretreatment of skinned ileal muscle with SM-1 abolished AV25-induced potentiation. We conclude, therefore, that, even though AV25 is an in vitro inhibitor of ZIPK, activation of the ZIPK pathway occurs following application of AV25 to permeabilized ileal smooth muscle. Finally, we propose a mechanism whereby conformational changes in the pseudosubstrate region of ZIPK permit augmentation of ZIPK activity toward LC20and MYPT1 in situ. AV25 or molecules based on its structure could be used in therapeutic situations to induce contractility in diseases of the gastrointestinal tract associated with hypomotility.
p53 inhibition of AP1-dependent TFF2 expression induces apoptosis and inhibits cell migration in gastric cancer cells
Authors: Tu Shui Ping , Chi Alfred L. , Ai Walden , Takaishi Shigeo , Dubeykovskaya Zina , Quante Michael , Fox James G. , Wang Timothy C.
Published: June 2009

Overexpression of trefoil factor 2 (TFF2) is associated with increased cell migration, resistance to apoptosis, and possibly increased gastric cancer invasion. Dysregulation of p53 is frequently observed in preneoplastic conditions of the stomach. Here, we investigated the effect of p53 on the expression and function of TFF2 in gastric cancer cell lines. Gene expression was determined by reverse transcription-polymerase chain reaction, and promoter activity was assessed by dual luciferase reporter assays. Apoptosis was detected by flow cytometry, and cell migration was evaluated by the Boyden chamber assay. Exogenous expression of p53 dose dependently inhibited endogenous TFF2 mRNA, protein, and promoter activity and resulted in induction of cell apoptosis and inhibition of cell migration. Downregulation of TFF2 by small interfering RNA sensitized gastric cancer cells to drug-induced p53-dependent apoptosis. Addition of human TFF2 peptide reversed p53-dependent apoptosis and inhibition of cell migration. The p53-responsive element was mapped to an AP-1-like cis-element at −182 bp upstream of the TFF2 transcription start site. Mutation of this AP-1-like element abrogated p53-mediated inhibition of TFF2 promoter activity. Gel shift and chromatin immunoprecipitation assays demonstrated that c-Jun and c-Fos bind to this AP-1-like element. Ectopic expression of c-Jun/c-Fos or p300 or treatment of cells with phorbol 12-myristate 13-acetate (PMA) stimulated endogenous TFF2 mRNA expression and promoter activity, and p53 inhibited the effects of AP-1 and PMA on TFF2. p53 induces cell apoptosis and inhibits cell migration in part by downregulating TFF2 expression through an AP-1-like site, suggesting that TFF2 may be an important downstream target of p53.
In vivo strain of the medial vs. lateral quadriceps tendon in patellofemoral pain syndrome
Authors: Wilson Nicole A. , Press Joel M. , Zhang Li-Qun
Published: June 2009

Patellofemoral pain (PFP) is thought to be related to patellar maltracking due to imbalances in the knee extensor. However, no study has evaluated the in vivo biomechanical properties of the quadriceps tendon in PFP syndrome. Our purpose was to compare the biomechanical properties of the quadriceps tendons in vivo and noninvasively in patients with PFP syndrome to those of control subjects. The null hypothesis was that the quadriceps tendons of PFP subjects would have significantly decreased strain compared with control subjects. Fourteen subjects (7 control, 7 PFP) performed voluntary ramp isometric contractions to a range of torque levels, while quadriceps tendon elongation was measured using ultrasonography. Tendon strain was calculated for the vastus medialis obliquus (VMO) and vastus lateralis (VL) portion of the quadriceps tendon and compared between subjects (control vs. PFP) and within subjects (VMO vs. VL). PFP subjects showed significantly less VMO tendon strain than control subjects ( P < 0.001), but there was no difference in VL tendon strain between PFP and control subjects ( P = 0.100). Relative weakness of the VMO is the most likely cause of the decreased tendon strain seen in subjects with PFP. VMO weakness not only explains the decreased medial tendon strain but also explains the presence of increased lateral patellar translation and lateral patellar spin (distal pole rotates laterally) reported in the literature in this population. This technique can potentially be used in a clinical setting to evaluate quadriceps tendon properties and infer the presence of muscle weakness in PFP.
The fastest runner on artificial legs: different limbs, similar function?
Authors: Weyand Peter G. , Bundle Matthew W. , McGowan Craig P. , Grabowski Alena , Brown Mary Beth , Kram Rodger , Herr Hugh
Published: June 2009

The recent competitive successes of a bilateral, transtibial amputee sprint runner who races with modern running prostheses has triggered an international controversy regarding the relative function provided by his artificial limbs. Here, we conducted three tests of functional similarity between this amputee sprinter and competitive male runners with intact limbs: the metabolic cost of running, sprinting endurance, and running mechanics. Metabolic and mechanical data, respectively, were acquired via indirect calorimetry and ground reaction force measurements during constant-speed, level treadmill running. First, we found that the mean gross metabolic cost of transport of our amputee sprint subject (174.9 ml O2·kg−1·km−1; speeds: 2.5–4.1 m/s) was only 3.8% lower than mean values for intact-limb elite distance runners and 6.7% lower than for subelite distance runners but 17% lower than for intact-limb 400-m specialists [210.6 (SD 13.2) ml O2·kg−1·km−1]. Second, the speeds that our amputee sprinter maintained for six all-out, constant-speed trials to failure (speeds: 6.6–10.8 m/s; durations: 2–90 s) were within 2.2 (SD 0.6)% of those predicted for intact-limb sprinters. Third, at sprinting speeds of 8.0, 9.0, and 10.0 m/s, our amputee subject had longer foot-ground contact times [+14.7 (SD 4.2)%], shorter aerial [−26.4 (SD 9.9)%] and swing times [−15.2 (SD 6.9)%], and lower stance-averaged vertical forces [−19.3 (SD 3.1)%] than intact-limb sprinters [top speeds = 10.8 vs. 10.8 (SD 0.6) m/s]. We conclude that running on modern, lower-limb sprinting prostheses appears to be physiologically similar but mechanically different from running with intact limbs.
Sympathetic neural responses to mental stress during acute simulated microgravity
Authors: Durocher John J. , Schwartz Christopher E. , Carter Jason R.
Published: June 2009

Neural and cardiovascular responses to mental stress and acute 6° head-down tilt (HDT) were examined separately and combined. We hypothesized sympathoexcitation during mental stress, sympathoinhibition during HDT, and an additive neural interaction during combined mental stress and HDT. Muscle sympathetic nerve activity (MSNA), mean arterial pressure (MAP), and heart rate (HR) were recorded in 16 healthy subjects (8 men, 8 women) in the supine position during three randomized trials: 1) mental stress (via mental arithmetic), 2) HDT, and 3) combined mental stress and HDT. Mental stress significantly increased MSNA (7 ± 1 to 12 ± 2 bursts/min; P < 0.01), MAP (91 ± 2 to 103 ± 2 mmHg; P < 0.01), and HR (70 ± 3 to 82 ± 3 beats/min; P < 0.01). HDT did not change MSNA or HR, but MAP was reduced (91 ± 2 to 89 ± 3 mmHg; P < 0.05). Combined mental stress and HDT significantly increased MSNA (7 ± 1 to 10 ± 1 bursts/min; P < 0.01), MAP (88 ± 3 to 99 ± 3 mmHg; P < 0.01), and HR (70 ± 3 to 82 ± 3 beats/min; P < 0.01). Increases in MSNA and HR during the combination trial were not different from the sum of the individual trials. However, the increase in MAP during the combination trial was significantly greater than the sum of the individual trials (change of 11 ± 1 vs. 9 ± 1 mmHg; P < 0.05). We conclude that the interaction for MSNA and HR are additive during combined mental stress and HDT but that MAP responses are slightly augmented during the combined trial. These findings demonstrate that sympathetic neural responses to mental stress are unaltered by simulated microgravity.
Outcome of Non-Variceal Acute Upper Gastrointestinal Bleeding in Patients with Antithrombotic Therapy
Authors: Ortiz V. , Ortuño J. , Rodríguez-Soler M. , Iborra M. , Garrigues V. , Ponce J.
Published: June 2009

Aim: To determine the influence of antithrombotic therapy upon the course of non-variceal upper gastrointestinal bleeding (UGB). Methods: A cohort study was made of consecutive patients admitted to hospital with non-variceal UGB. Three cohorts were defined: patients receiving vitamin K antagonists (AC); patients with antiplatelet treatment (AP), and patients with neither of these treatments (noACAP) as control group. Outcome was assessed by: (a) number of days in hospital; (b) mortality rate; (c) need for urgent surgery, and (d) rebleeding. The measure of the association between antithrombotic therapy and the course of UGB was adjusted for confounders (age, sex, comorbidity, and the use of NSAIDs and PPIs at the time of UGB presentation). Results: A total of 392 consecutive patients were included: 43 were AC, 107 AP, and 242 noACAP patients. There were no significant differences among groups in terms of rebleeding (AC 11.6%, AP 7.5%, NoACAP 9.1%), the need for urgent surgery (AC 2.3%, AP 1.9%, NoACAP 1.2%) or mortality rate (AC 4.7%, AP 5.6%, NoACAP 5.8%). The number of days in hospital was greater in the AC cohort (4.81 more days; 95% CI 2.83–6.79, p < 0.001). After adjusting for age and comorbidity, the increase in days in hospital among the AC patients was 3.24 days (95% CI 1.22–5.26). Conclusions: Neither anticoagulation nor antiplatelet treatment exerts an influence upon the course of non-variceal UGB. Nevertheless, anticoagulation is associated with a longer hospital stay. This is partially explained by the older age and increased comorbidity of the patients subjected to such treatment.
Endogenous Activated Protein C Predicts Hemorrhagic Transformation and Mortality after Tissue Plasminogen Activator Treatment in Stroke Patients
Authors: Mendioroz Maite , Fernández-Cadenas Israel , Alvarez-Sabín José , Rosell Anna , Quiroga Dorita , Cuadrado Eloy , Delgado Pilar , Rubiera Marta , Ribó Marc , Molina Carlos , Montaner Joan
Published: June 2009

Background: Activated protein C (APC) is a plasma serine protease with systemic anticoagulant and a wide spectrum of cytoprotective activities that has been proposed as a promising therapy for acute stroke. Therefore, we sought to investigate the role of endogenous APC in human ischemic stroke. Methods: Our target were 119 consecutive patients with an ischemic stroke involving the middle cerebral artery territory who received tissue plasminogen activator (t-PA) within 3 h of symptom onset. APC was measured before, as well as 1 and 2 h after t-PA administration, and again at 12 and 24 h after stroke onset. Cranial tomography scan was obtained at admission and repeated at 24–48 h or when a neurological worsening occurred to rule out the presence of hemorrhagic complications. The functional outcome was evaluated by 3-month modified Rankin Scale. Results: A total of 117 t-PA-treated patients were finally included in the analyses. APC peaked at 1 h after t-PA administration (pretreatment APC = 132.44 ± 36.39%, 1-hour APC = 184.20 ± 34.28%, 2-hour APC = 145.50 ± 35.23%; p < 0.0001). Interestingly, a high 2-hour APC level was associated with parenchymal hemorrhages (OR = 25.19; 95% CI = 4.76–133.19; p = 0.0001) and mortality (OR = 13.8; 95% CI = 2.58–73.63; p = 0.001), in a logistic regression model. Our results remained significant after Bonferroni correction for multiple testing. Conclusions: A high endogenous APC level 2 h after t-PA administration is independently associated with hemorrhagic transformation and mortality in our cohort of stroke patients. Establishing any causal link for these relationships needs further research.
Sequence Identity between the Genomes of Humans and Viruses
Authors: Lin Gui-Gao , Li Jin-Ming
Published: June 2009

Objective: People exposed to viruses usually do not develop diseases. Viruses cause diseases; however, most of the pathologic effects of these diseases are not caused directly by the viruses but by the side effects of the immune response. It is possible that sequence identity may exist between viruses and humans and may be biologically relevant to the infection of virus. The aim of this study was to find out whether sequence identity exists between viruses and humans. Methods: BLAST searches of virus genome sequences against human genome were performed using the resources of the National Center for Biotechnology Information (NCBI). Results: All the viruses that were compared to humans contain different numbers of short identical regions to the human genome. Each identical region was 20–30 nt and some were found at multiple sites within the human genome. Conclusion: A new role of the virus in the relationship between viruses and humans was taken into account. We assume that viruses have brought their sequence into the human genome in the long past history of human-virus interaction. In the process, viruses play roles as carriers to transfer external sequence information into the human genome.
Erfassung der Gefährdungslage mit Hilfe ernährungsdiagnostischer Untersuchungen bei chirurgischen Patienten
Authors: Schmoz G. , Hartig W. , Brunner H.-P. , Weiner R. , Erhard V. , Vetter K.
Published: June 2009

Die Diagnostik des Ernährungszustands ist ein wesentlicher Bestandteil der Erfassung der Gefährdungslage bei Patienten mit Karzinomen des Verdauungstrakts. Nach den Ergebnissen multivariater statistischer Analysen zahlreicher biochemischer, anthropometrischer und immunologischer Parameter bei 63 Patienten mit Magenkarzinom können wir heute die Bestimmung des Ernährungszustands wesentlich vereinfachen. Mit Hilfe der Clusteranalyse und zusammen mit klinischen Aspekten kann der Ernährungszustand im Gegensatz zur bisherigen Klassifizierung («normal» und mehrere Störungsgrade) in 2 Gruppen («normal» und «gestört») eingeteilt werden. Mit Hilfe der Diskriminanzanalyse wurde eine Merkmalskombination gefunden, die eine hinreichend gute Diskrimination der Probanden in eine der Gruppen «normal» und «gestört» zuläβt und damit den Ernährungszustand charakterisiert. Die Zuordnung der Patienten trifft in 97% der Fälle zu. Bei der Diskriminanzanalyse konnten 6 praxisrelevante Merkmale ermittelt werden, und zwar Serumalbumin, Serumtransferrin, Hämoglobin, Oberarmmuskelumfang, Trizepshautfaltendicke und der intrakutane Hauttestquotient. Daraus kann der Ernährungsquotient EQ2 ermittelt werden (im Vergleich zum Ernährungsquotienten EQ1 nach dem 33-Punkte-Bewertungsschema), womit eine Quantifizierung möglich ist. Die Verwendung nur einzelner Parameter ergibt gröβere Differenzen von den gewonnenen Ergebnissen mit 6 Parametern. Allerdings kann durch die Ergebnisse besonders der Hauttestreaktionen übereinstimmend mit den Ergebnissen der Lymphozytentransformation ein Zusammenhang zwischen Ernährungszustand und der aktuellen Immunokompetenz vermutet werden. Die Untersuchungsergebnisse der zellvermittelten Immunität repräsentieren insbesondere das Ausmaβ einer herabgesetzten immunologischen Reaktion gegenüber den Ergebnissen der humoralen Immunität. Die Einbeziehung weniger aufwendiger immunologischer Untersuchungsverfahren bleibt zukünftigen Erhebungen vorbehalten. Als eine praxisrelevante und verläβliche Zusatzuntersuchung für die Beurteilung der aktuellen Stoffwechsellage kann die Bestimmung der täglichen Harnstoffproduktion (Harnstoffproduktionsrate; in Abhängigkeit von der Eiweiβzufuhr) herangezogen werden.
Über den parenteralen Einsatz einer Fettemulsion in der frühen postoperativen Phase
Authors: Weidler B. , Prinzler H.-J. , Bormann B.v. , Lohmann E. , Muhrer K.H. , Hempelmann G.
Published: June 2009

In einer randomisierten prospektiven Studie wurde an 30 Patienten in der postoperativen Phase der alternative Einsatz eines Kohlenhydrat-regimes (= Kontrollgruppe) im Vergleich mit einem teilweisen Ersatz der Kohlenhydratkalorien durch eine Fettemulsion (= Fett-Kohlenhydrat-Regime) getestet. Neben den üblichen Routine-Laborparametern wurde mittels Stickstoffbilanz und Analyse der kurzlebigen Proteine sowie verschiedener Meβparameter des Fettstoffwechsels überprüft, mit welchen metabolischen Konsequenzen, sowohl im Bereich des Proteinstoffwechsels als auch im Bereich des Fettstoffwechsels, bei den genannten Regimen zu rechnen ist. Die drei verwendeten Ernährungsregime führten zu weitgehend vergleichbaren metabolischen Ergebnissen, wobei unter hoher Fettdosierung (3 g/kg KG/Tag) ein nicht signifikanter Anstieg der Triglyzeridspiegel über die Vergleichswerte der Kontrollgruppe registriert wurde. Von seiten der Stickstoffbilanz sowie von seiten der weiteren Parameter des Proteinstoffwechsels erwies sich das Regime mit 1,5 g Fett/kg KG/Tag als das günstigste. Gravierende Dysregulationen im Bereich des postoperativen Stoffwechsels konnten nicht registriert werden, die verwendete Fettemulsion erwies sich auch in bezug auf die pulmonale Funktion der untersuchten Patienten als günstig. In Kombination mit Kohlenhydraten und Aminosäuren bietet das Kohlenhydrat-Fett-Regime offensichtlich bessere postoperative metabolische Profile, von denen besonders Patienten mit reduziertem Ernährungszustand und verminderter respiratorischer Reserve profitieren können.
Loading and Maintenance Dose for the Determination of Amino Acid Kinetics in Plasma
Authors: Kleinberger G. , Heinzel G. , Druml W. , Laggner A. , Lenz K.
Published: June 2009

Die intravenöse Boluskinetik von Aminosäuren und die Berechnung der kinetischen Parameter mit einem Einkompartementmodell zeigt methodische Limitierungen. Es wurde daher ein neues Studienprotokoll, das eine Bolus- und Infusionsapplikation von Aminosäuren vorsieht, entwickelt. Der Konzentrationsverlauf der Aminosäuren im Plasma wurde nach einem 2-Kompartementmodell ausgewertet. Der Versuchsplan wurde bei 9 stoffwechselgesunden, freiwilligen Versuchspersonen, die nach einer nächtlichen Fastenperiode untersucht wurden, getestet. Die Bolusdosis betrug 20 g Aminosäuren/kg/min für 5 min und die Erhaltungsdosis 5 mg Aminosäuren/kg/min für 55 min. Nach Absetzen der konstanten Infusionsrate wurde für weitere 120 min die Konzentration der Plasmaaminosäuren untersucht. Die Plasmaaminosäuren wurden mit einem Biotronic LC 6001 und die kinetischen Parameter mit einem Wang 2200 Computer mit dem TOPFIT Programm ausgewertet. Die Ergebnisse zeigten (Mittelwert ± SE) ein Verteilungsvolumen von 4,7 ± 0,6 bis 9,4 ± 1,8 1, eine Eliminationskonstante von 1,7 ± 0,5 bis 11,0 ± 2,1/h, eine totale Clearance von 168 ± 37 bis 846 ± 66 ml/min und eine Transferrate bzw. endogene Produktionsrate zwischen 12 ± 0,8 und 135 ± 16 μmol/ kg/h. Der gesamte Transfer betrug 17,6 mmol/kg/d (= 2,2 g Aminosäuren/kg/d). Aus den Ergebnissen kann geschlossen werden, daβ eine Optímierung des Versuchsplanes für die Untersuchung der Aminosäurenkinetik eine Anhebung der Konzentration der Plasmaaminosäuren auf das 2–3fache über den Basalwert erfordert. Die Gesamtdauer der Infusion und die Dauer der Abfallkinetik soil 3 h nicht überschreiten und das Aminosäurengemisch für die Untersuchung alle für die Ernährung empfohlenen Aminosäuren enthalten. Schlieβlich soil die Berechnung der kinetischen Parameter auf einem 2-Kompartementmodell oder auf einer modellfreien Berechnung basieren.
The Use of Peritoneal Dialysis as a Means of Supplying Nutrients
Authors: Cavallé Obiols F. , Monterde Junyent J. , Schwarts Riera S. , Farriol Gil M.
Published: June 2009

Es wurden Untersuchungen durchgeführt, die zeigen, daß der peritoneale Zugang benutzt werden kann, um sowohl eine periodische Peritonealdialyse als auch eine nutritive Aminosäurenversorgung durchzuführen. Gleichzeitig wurde der Einfluß unterschiedlicher Aminosäurenmuster der zugeführten Lösungen untersucht. Dazu wurden drei Gruppen von Patienten verwendet. Bei der Kontrollgruppe wurde die Peritonealdialyse ohne Aminosäurenzusatz durchgeführt. Die Gruppen 2 und 3 erhielten zusätzlich Aminosäurenlösungen, aber mit einem unterschiedlichen Muster.
Stoffwechselorientierte postoperative Ernährungstherapie – Möglichkeiten und Grenzen der Anwendung von Glukose und Xylit
Authors: Georgieff M. , Moldawer L.L. , Wagner D. , Geiger K. , Fekl W. , Blackburn G.L. , Bistrian B.R. , Lutz H.
Published: June 2009

Kohlenhydrate und Polyole sind wesentliche Bestandteile der intravenösen Ernährungstherapie. Um die Problematik der Versorgung mit Energieträgern besser zu verstehen, wird zunächst auf die Physiologie der enteralen Nährstoffzufuhr eingegangen und der intravenösen Substratzufuhr gegenübergestellt. In dieser Übersichtsarbeit wird auf die Stoffwechselwirkung von Glukose und Xylit eingegangen, und daraus werden resultierende therapeutische Konsequenzen für deren intravenöse Anwendung bei den verschiedenen Erkrankungen gezogen.
Die Stellung der Kell-Inkompatibilität im Rückblick auf 15 Jahre Mutter-Kind-Paß-Serologie
Authors: Schönitzer D.
Published: June 2009

Basierend auf den Ergebnissen von Antikörpersuchtests bei 80509 im Rahmen der Mutter-Kind-Paß-Untersuchung getesteten Schwangeren der Jahre 1971–1985 wird über Häufigkeit und klinische Bedeutung der Antikörper gegen das Blutgruppenmerkmal Kell (K) berichtet. Die Stammbäume von zwei, durch Kell-Inkompatibilität betroffenen Familien illustrieren den oft tragischen Ausgang solcher Schwangerschaften. Durch erweiterte Nachuntersuchungen in den betroffenen Familien konnten 7 Kell-Inkompatibilitäten bei insgesamt 134 Schwangerschaften von 43 Anti-Kell-Trägerinnen serologisch als solche abgesichert werden. Davon führten 3 zu Totgeburten, 1 zu bleibenden neurologischen Ausfallserscheinungen, 1 zu Ikterus ohne nachweisbare Dauerschäden und 2 zu Austauschtransfusionen bei heute gesunden Kindern. Empfehlungen über Techniken und Zeitpunkt von Antikörpersuchtests und Fruchtwasseruntersuchungen leiten über zur Abklärung des Sensibilisierungsmodus, aufgrund dessen wir uns zur Kell-ausgewählten Bluttransfusion entschlossen haben. Überlegungen bezüglich Schutzmechanismen gegenüber Antikörperbildung durch ABO-Blutgruppenverschiedenheit zwischen Mutter und Kind sowie durch Rhesusprophylaxe werden angestellt. Das Übersehenwerden bzw. die verspätete diagnostische Erfassung stellen das Hauptproblem der Kell-Inkompatibilitäten dar.
Thrombozytentransfusion: Plättchenanstieg in Abhängigkeit von klinischen und immunologischen Voraussetzungen
Authors: Panzer S. , Maier F. , Höcker P. , Mayr W.R. , Hinterberger W.
Published: June 2009

Bei 35 Patienten mit schwerer transfusionsbedürftiger Thrombozytopenie (AML n = 10; ALL n = 4; CML n = 1; idiopathische Myelofibrose n = 1; aplastische Anämie n = 1; aplastische Phase nach Knochenmarktransplantation n = 18) wurden insgesamt 195 Plättchentransfusionen untersucht und der posttransfusionelle Plattchenanstieg (CCI) bestimmt. Bei 44% (n = 86) war der Transfusionserfolg ungenügend (CCI < 5 × 109 Plättchen/l). Eine Analyse der Faktoren, die dafür verantwortlich sein könnten, zeigte, daβ bei Patienten mit Splenomegalie und/oder Fieber der Prozentsatz der Transfusionsversager signifikant höher war (54% vs. 29%; p < 0,002). Nur bei zwei Patienten konnten Antikörper gegen Spenderplättchen nachgewiesen werden. Es fand sich keine Korrelation zwischen dem Vorhandensein von Antikörpern, die mit dem lymphozytotoxischen Test (n = 144) oder dem Radioimmunantiglobulintest (n = 67) und dem posttransfusionellen Plattchenanstieg erfaβt werden konnten. Der Grad der HLA-Antigenübereinstimmung (n = 192) erwies sich als nicht prädiktiv für den Transfusionserfolg. Die Untersuchung zeigt, daβ eine Voraussage des Transfusionserfolgs durch In-vitro-Antikörpersuchtests bei Patienten mit niedrigem Immunisierungsgrad nicht möglich ist. Klinisch erfaβbare Parameter sind für den Transfusionserfolg entscheidend.
Gewinnung von Thrombozytenkonzentraten und gerinnungsaktivem Frischplasma mit dem System Haemonetics PCS
Authors: Glück D. , Koerner K. , Stampe D. , Kubanek B.
Published: June 2009

Der durch intensivere Chemotherapie-Schemata bei hämatologischen und onkologischen Patienten deutlich gesteigerte Bedarf an Thrombozyten-Konzentraten forderte, neben der Präparation von Thrombozyten-Konzentraten (TK) aus frischem Vollblut Verfahren zur selektiven Gewinnung von TK zu erschlieβen. Die Möglichkeit, Plasma in kürzeren Zeitintervallen als Vollblut spenden zu können, regte die Entwicklung und den Einsatz von konventionellen Maschinen zur Plasmapherese mit simultaner Thrombozytengewinnung an. In einer Testreihe untersuchten wir die Effektivität des Verfahrens und die Qualität der Präparate Frischplasma und Thrombozyten-Konzentrat bei dem von der Firma Haemonetics Corp. (Braintree, Mass.) als Weiterentwicklung neu angebotenen System PCS. Die durch unsere Routinepräparate Fresh frozen plasma und TK vorgegebenen Qualitätskriterien konnten bei der gleichzeitigen Gewinnung von beiden Präparaten nicht erreicht werden.
Einfluß von wiederholten Leukozytapheresen auf das Lymphozytogramm von Blutspendern
Authors: Laser J. , Krüger J.
Published: June 2009

Sowohl bei Thrombozyt- als auch Leukozytapheresen kommt es zu einem erheblichen Lymphozytenverlust, dessen Bedeutung derzeit spekulativ ist. In der vorliegenden Untersuchung wurden bei 10 gesunden Probanden 5 Leukozytapheresen in wöchentlichen Abständen durchgeführt, die einen kumulativen Lymphozytenverlust von 2,6 × 1010 Zellen zur Folge hatten. Dies führte zum signifikanten Rückgang der peripheren Gesamtlymphozytenzahl von 1850 ± 417/µl auf 1451 ± 411/µl. Auch die Anteile von OKT3+-, OKT4+- und B-Zellen verminderten sich signifikant, nicht jedoch der Anteil der OKT8+-Zellen. Der OKT4/OKT8-Quotient veränderte sich entspre-chend von 1,41 ± 0,25 auf 1,32 ± 0,27. Auch 6 Monate nach der letzten Leukozytapherese waren die Gesamtlymphozytenzahl sowie der Anteil der OKT3+- und B-Zellen noch signifikant erniedrigt. Aus der langen Persistenz der gefundenen Veränderungen ergibt sich, daß auch der Lymphozytenverlust von Zytapheresespendern bei der Beurteilung der Spendesicherheit berücksichtigt werden muß. 1000 Lymphozyten/µl können als Ausschlußkriterium gelten.
Bindung von Pharmaka an künstliche Plasmaersatzmittel
Authors: Borchardt W. , Heinzow B. , Ziegler A.
Published: June 2009

Die Bindung von Pharmaka an Plasmaproteine ist gut untersucht und die therapeutische Bedeutung dokumentiert. Auch die Bindung von Pharmaka an Dialysemembranen und Infusionssysteme ist beschrieben, während wenig über die Bindung an künstliche Kolloide (Plasma-expander) bekannt ist. Da Plasmaexpander eine breite Anwendung erfahren, sollte das Bindungsverhalten von Pharmaka an diese Makromoleküle mittels der Gleichgewichtsdialyse untersucht werden. Benzodiazepine, β-Blocker, Herzglykoside, Lokalanästhetika, nicht-steroidale Antirheumatika, Glibenclamid, Phenobarbital und Phenprocoumon wurden eingesetzt in einer Konzentration von 1 × 10––7 mol/l in Tris-Puffer und die Bindung an 1:5 mit Tris-HCl-Puffer verdünnte handelsübliche Plasmaersatzmittel ermittelt, die als Makromoleküle Hydroxyäthylstärke (HAS), Dextran, Gelatine und Polyvinylpyrrolidon (PVP) enthalten. Die Pharmakonbindung an Plasmaersatzmittel war in alien Fallen geringer als an Plasmaproteine. Die höchste Bindung wurde für Penbutolol mit Oxypolygelatine (43%), Digitoxin und HAS 200 (36%) sowie Phenprocoumon und PVP (43%) gefunden. Die Bindung von Pharmaka an künstliche Kolloide ist in den meisten Fallen gering und ohne klinische Bedeutung. Im Rahmen von Perfusionsexperimenten an isolierten Organen sollte eine mögliche Bindung der untersuchten Pharmaka an künstliche Kolloide jedoch berücksichtigt werden.
Vergleichende Untersuchung zur Beeinflussung von Blut, Blutgerinnung, Herz und Kreislauf durch 3%ige modifizierte, flüssige Gelatine und 6%ige niedermolekulare Hydroxyäthylstärke
Authors: Hopf H.-B. , Siepmann H.P.
Published: June 2009

Es wird über eine randomisierte, vergleichende Untersuchung mit 3%iger modifizierter flüssiger Gelatine und 6%iger niedermolekularer Hydroxyäthylstärke an 87 Patienten einer Intensivstation berichtet. Beide Plasmaersatzmittel waren gut verträglich. Die Blutsen-kungsgeschwindigkeit wurde durch beide Infusionslösungen signifikant verlängert. Dieser Effekt war nach 24 h noch maximal nachweisbar und in der mit dem Gelatine-Präparat behandelten Patientengruppe prozentual ca. dreifach starker ausgeprägt, bezogen auf den Ausgangswert. Die Thrombozytenzahl verringerte sich in der Hydroxyäthylstärke-Gruppe nach 12 h um 10,3%, in der Gelatine-Gruppe nur um 1,5%; weitere Unterschiede zwischen den beiden Präparaten konnten bei den klinischchemischen Parametern nicht ermittelt werden. Bezogen auf die Änderungen des Zentralvenendrucks zeigten beide Präparate eine mittlere Volumenwirksamkeit von 4 h. Das Gelatine-Präparat bewirkte unmittelbar nach Infusionsende eine statistisch signifikante Blutdrucksteigerung, das Hydroxyäthylstärke-Präparat nicht. Beide Präparate bewirkten mit einer Latenz von 1 h eine Steigerung der Diurese. Ein Unterschied zwischen beiden Lösungen bezüglich des diuretischen Effekts konnte nach Infusion nicht ermittelt werden.