bluuebunny/crossref_metadata_2025 huggingface dataset:
A Single Unit of Transfused Allogeneic Blood Increases Postoperative Infections
Authors: Vignali Andrea , Braga Marco , Gianotti Luca , Radaelli Giovanni , Gentilini Oreste , Russo Antonio , Di Carlo Valerio
Published: May 2003

The aim of this prospective study was to evaluate if there was a statistical correlation between allogeneic blood transfusion and postoperative infections, and if this could have a dose‐dependent pattern. The evaluation was based on multiple logistic and receiver operating characteristics (ROC) curve analyses. On hospital admission the following parameters were determined in 267 consecutive patients with colorectal cancer: hemoglobin, serum albumin, serum cholinesterase activity, total iron binding capacity and weight loss. Duration of operation, operative blood loss, amount of transfused blood, Dukes’ cancer stage and occurrence of postoperative infections were also recorded. One hundred and thirty‐two patients (49.4%) were given perioperatively allogeneic blood. Postoperative infections developed in 47 (17.6%) patients. Multivariate analysis identified allogeneic blood transfusion as the only variable related to the occurrence of postoperative infections (p < 0.05). ROC curve analysis showed that the risk for the occurrence of infection was significantly higher in patients transfused one unit of blood (p < 0.01). Moreover, a significant trend between increasing number of transfused blood units and susceptibility to infection was found (p < 0.00019).
Quantitation of Rh D Antigen Sites on Weak D and D Variant Red Cells by Flow Cytometry
Authors: Jones J.W. , Lloyd‐Evans P. , Kumpel B.M.
Published: May 2003

Information on the number of D sites on weak D (Du) and D variant cells is limited and incomplete. The aim of this study was to use a simple non‐isotopic technique utilising a combination of flow cytometry and ELISA to quantitate the number of D sites on an extensive range of these cells. Five human monoclonal IgG anti‐D (BRAD‐7 (JAC10), BRAD‐5, 2B6, BRAD‐3, H27) and one affinity‐purified polyclonal IgG anti‐D were each used at a saturating concentration of 20 μg/ml. In general, BRAD‐3, BRAD‐5 and 2B6 gave the highest number of D sites per cell (SPC), H27 and the polyclonal anti‐D were slightly lower, while BRAD‐7 gave the lowest SPC with all D‐positive cells tested except DFR. Interestingly, BRAD‐7 gave the highest SPC with DFR cells. Rh D antigen density for R2R2 cells was approximately double that seen with either R2r or Ro (presumed Ror) cells. R1R1 cells gave only moderately higher SPC than R1r cells. Higher SPC were obtained with the R1 haplotype if the Cw antigen was present. Weak D, Va and VI cells of the R1 haplotype had higher SPC than those of the R0 or R2 haplotypes. The majority of D variant cells were found to have lower SPC than normal cells, and for polyclonal anti‐D, which was the only anti‐D to react with all D variants, SPC decreased in the order IIIc > IIIa > HMii > IVa > Va > DFR > DBT > IVb > VII > II > HMi > VI. The number of molecules of IgG anti‐D bound to D variant cells varied by up to 10 times with reactive monoclonal antibodies. The highest SPC on weak D and D variant cells were obtained with BRAD‐7 (DFR, 9,500), BRAD‐3 (Va, 12,500), BRAD‐5 (II, 5,500; VII, 5,300; weak D, 1,300), H27 (III, 24,000; VI, 2,900; HMi, 3,000; HMii, 16,800) and polyclonal anti‐D (IVa, 9,300; IVb, 4,000; DBT, 4,300).
Autoimmune Haemolytic Anaemia in Infancy with Anti‐Kpb Specificity
Authors: Win N. , Kaye T. , Mir N. , Damain‐Willems C. , Chatfield C.
Published: May 2003

Autoimmune haemolytic anaemia (AIHA) in infancy is rare. We report a case of AIHA in a male infant whose serum contained an antibody with apparent anti‐Kpb specificity. Autoantibody with anti‐Kpb specificity has been described in adults; to our knowledge, this is the first case of this kind described in infancy with AIHA. Clinical course and response to red cell transfusion are described.
Evaluation of a Solid‐Phase Test for Erythrocyte Antibody Screening of Pregnant Women, Patients and Blood Donors
Authors: Sallander S. , Shanwell A. , Åqvist M.
Published: May 2003

We have studied a previously described solid‐phase test (SPH) for screening and identification of antibodies directed against erythrocyte antigens, in large sample numbers and throughout routine processing. The screening results of all samples from pregnant women, patients and blood donors (n = 36,701) sent to our blood bank from August 1992 to July 1993 were compiled and evaluated. Pregnant women were screened by the SPH‐antiglobulin technique (IAT) and the SPH‐enzyme‐enhanced technique (ENZ), while the patients and blood donors were screened only by the SPH‐IAT. Samples with known alloimmunization were excluded from this study. Positive screening reactions were further investigated by the SPH‐IAT and SPH‐ENZ techniques, the manual hemagglutination tests low ionic‐strength solution IAT and 2‐stage papain. Pregnant women: A positive reaction in one or both of the SPH tests was found in 1.2% of the samples. The SPH tests identified 99 (98.0%) and the manual methods 79 (78.2%) of a total of 101 antibodies. Of the identified antibodies, 61 were to antigens in the Rh blood group system, including 34 Rh immune globulin. The remainder had specificity directed against antigens K, Jka, M, S, Lea and Leb. Patients: A positive reaction in the SPH‐IAT test occurred in 0.9% of the samples. The antibodies identified had specificity directed against antigens D, C, c and E in the Rh blood group system. The remainder had specificity directed against antigens Fya, K, Jka, M and Lea. All antibodies identified by SPH‐IAT, except 1 anti‐M and 2 anti‐Lea, were also identified by manual methods. Blood donors: A positive reaction in the SPH‐IAT test was noted in 0.7% of the samples. The identified antibodies had specificity directed against antigens D, C, E, Fya, K and M. All antibodies identified by the SPH‐IAT, except 1 anti‐D found in a sample from an RhD(+) male, were also identified by the manual methods. This study indicates that the SPH‐IAT test is sensitive for detecting anti‐M. This was also indicated for the SPH‐ENZ test concerning the Jka antibody. An advantage of using solid‐phase antibody screening tests for a larger series of samples is the possibility of automated sample identification, dilution, dispensing and interpretation of results. The SPH‐IAT and the SPH‐ENZ tests permitted us to select test cells, preferably from our own donor pool. We conclude that the SPH‐IAT and SPH‐ENZ tests are suitable for routine antibody screening of pregnant women and the SPH‐IAT test for screening patients and blood donors.
X‐Irradiation Does Not Affect the Levels of Complement Regulatory Proteins, CD35 (CR1), CD55 (DAF) and CD59 on Concentrated Red Cells
Authors: Fukumori Yasuo , Seya Tsukasa , Ohnoki Shiro , Shibata Hirotoshi , Yamaguchi Hideo
Published: May 2003

Human erythrocytes express complement (C) regulatory proteins, C3b/C4b receptor (CR1, CD35), decay‐accelerating factor (DAF, CD55) and CD59, which protect cells from autologous C attack [1]. CR1 and DAF are C3‐step regulators which destabilize the classical and alternative C3 convertases [1]. In addition, CR1 can bind C4b and C3b in the immune complexes to clear them from the circulation, namely immune adherence [2]. CD59 inhibits the formation of membrane attack complexes [1].
Terminology for Red Cell Surface Antigens
Authors: Daniels G.L. , Anstee D.J. , Cartron J. P. , Dahr W. , Henry S. , Issitt P.D. , Jørgensen J. , Judd W.J. , Kornstad L. , Levene C. , Lomas‐Francis C. , Lubenko A. , Mallory D. , Moulds J. M. , Moulds J. J. , Okubo Y. , Overbeeke M. , Reid M. E. , Rouger P. , Seidl S. , Sistonen P. , Wendel S. , Zelinski T.
Published: May 2003

The Working Party met at Makuhari Messe, Japan on 31 March 1996. A few changes to the current classification, documented in Blood Group Terminology 1995 [1], were agreed and these are described below.
Leukocyte Depletion and Storage of Single‐Donor Platelet Concentrates
Authors: Weisbach Volker , Putzo Alexander , Zingsem Jürgen , Riewald Matthias , Zimmermann Robert , Eckstein Reinhold , Riess Hanno
Published: May 2003

Background and objectives: Because of widespread use of leukocyte reduction in platelet concentrates (PCs) and the need to store such concentrates, we investigated the effects of leukocyte depletion on the quality of stored PCs. Materials and methods: Ten double‐sized PCs were divided into 2 equal units which were tested simultaneously. One half was stored for 5 days after filtration through a polyester filter, the other one was stored unfiltered. Results: The volume of the 10 ‘oversizeD' PCs was 483±40 ml (mean ± standard deviation) and they contained 5.9±1.5 × 1011 platelets and 80±23 × 106 leukocytes. Filtration significantly reduced the leukocyte concentration (168±56/μl before, 6±4/μl after filtration) and leukocyte count (39.9±11.3 × 106 vs. 1.3±0.9 × 106; p < 0.0005). Filtration caused a platelet loss of 16%, the platelet count decreasing not significantly from 2.91±0.75 × 1011 to 2.40±0.94 × 1011 (p = 0.26). After 5 days of storage all parameters of platelet function (platelet aggregation to several stimuli, hypotonic shock reaction [HSR] and platelet retraction), mean platelet volume, and pH and pCO2 showed no advantage for PCs filtered prior to storage compared to PCs stored unfiltered. Moreover, platelet aggregation on day 5 using 4 agonists at 10 concentrations showed worse results in 4 assays in prestorage filtered PCs (collagen [4 μg/ml: p < 0.05, ADP [0.2 mM]: p < 0.05, ADP [0.3 mM]: p < 0.05, thrombin [0.6 E/ml]: p < 0.05). But there is no convincing trend in all aggregation tests, and HSR, presumably the most useful parameter, was not different on day 5. Conclusions: There is no advantage in terms of improved quality for prestorage leukodepletion of PCs. Taking into account the obvious disadvantages of filtration, such as platelet loss and increasing costs per transfusion, we conclude that pre‐ or post‐storage filtration of single‐donor PCs should be done only for patients who have a clear indication for the transfusion of leukocyte‐poor blood products.
Human Monoclonal Fab Fragments Recovered from a Combinatorial Library Bind Specifically to the Platelet HPA‐1a Alloantigen on Glycoprotein IIb–IIIa
Authors: Proulx Chantal , Chartrand Pierre , Roy Valérie , Goldman Mindy , Décary Francine , Rinfret Aline
Published: May 2003

Background and objectives: Certain clinical conditions are related to the presence of platelet‐specific alloantibodies in the patient's serum. We studied the molecular diversity of HPA‐1a antibodies to analyze some peculiarities of this antibody response. Materials and methods: Human antibody Fab fragments that bind to the platelet alloantigen HPA‐1a on glycoprotein IIb–IIIa (GPIIbIIIa) were generated by using a recombinant phage display system. We established an immunoglobulin G1, kappa combinatorial library from the peripheral blood lymphocytes of a person undergoing a severe posttransfusion purpura. Results: Characterization of Fab clones selected from the fifth round of antigen‐specific panning of this library demonstrates a highly specific reactivity to the HPA‐1a alloantigen. The nucleotide sequence analysis of representative HPA‐1a‐specific clones reveals at least 3 distinct VL and 3VH gene segments that present an extensive degree of mutation as demonstrated by comparison of gene usage and homologies to the nearest germline genes. Conclusions: These human HPA‐1a‐specific Fab reagents should allow us to better understand the molecular mechanism involved in HPA‐1a alloimmunization.
Der Rumpfdarm des Burunduk (Eutamias sibiricus, Laxm. 1769): Makroskopische und lichtmikroskopische Untersuchungen*
Authors: Nieters M. , Schnorr B. , Kressin M.
Published: May 2003

The canalis alimentarius of the Burunduk (Eutamias sibiricus), a rodent belonging to the family Sciuridae, were examined macroscopically (12 animals) and light microscopically (three animals).

The esophagus is lined with a stratified non‐keratinized squamous epithelium. The one‐chambered stomach is of a simple type covered with a glandular mucous membrane. When empty and moderately filled, the stomach looks like a curved sack and lies intrathoracally. The filled stomach extends to the left and ventrally into the regio abdominis media. The greater omentum covers incompletely ventrally and in a part laterally the intestinal mass. The intestinal canal averages about 780 mm in length, that is 6.5 as long as the whole body. The relative length of the small intestine compared with the large intestine is 36–64%. The U‐shaped Duodenum is composed of a Pars cranialis, descendens and ascendens and possesses a Plica duodenocolica as well as a Plica duodenocolica accessoria. The Jejunum averages about 420 mm length and is mainly located in the right and ventral part of the regio abdominis media. As in other rodents, the cecum is well developed. The length of the ascending colon averages about the body length and forms an Ansa proximalis and two parallel loops, Ansa media and Ansa distalis coli, both lying in the right Cavum abdominis. Peculiar for the colon are Noduli lymphatici solitarii surrounding cavities lined by a surface epithelium. According to the anatomical struture of the gut and based on physiological diet facts the Burunduk is not a mere herbivore but has to be classified as an omnivore depending upon uptake of animal food protein.
Anatomical Relationship Between Enkephalin‐Containing Neurones and Caecum‐Projecting Neurones in the Chicken Intestinal Nerve
Authors: Ohmori Y. , Suzuki M. , Fukuta K.
Published: May 2003

The anatomical relationship between enkephalin‐immunoreactive neurones and caecum‐projecting neurones in the intestinal nerve of Remak (INR) of the chicken was investigated using retrograde transport of cholera toxin subunit B and immunohistochemistry with anti‐enkephalin serum. After injection of cholera toxin into the base or body of the caecum, labelled neurones were mainly observed in the cranial part of the rectal INR. Enkephalin‐immunoreactive neuronal cell bodies were found in the caudal part of the rectal INR and their fibres closely surrounded caecum‐projecting neurones in the cranial part of the rectal INR. Diameters of caecum‐projecting neurones surrounded with enkephalin‐containing terminals were significantly larger than those of caecum‐ projecting neurones without enkephalin‐terminals (P < 0.01). From these results, it is suggested that enkephalin‐containing neurones are able to affect large‐sized caecum‐projecting neurones. This pathway may be involved with unique motility of the rectum and caeca that uric acid is retrogradely carried from the cloaca to the caeca.
Influence of dietary beetpulp on the plasma level of triacylglycerols in horses
Authors: Hallebeek J. M. , Beynen A. C.
Published: May 2003

In a cross‐over study with six adult horses, the effect of isoenergetic replacement of dietary glucose by beetpulp on the concentration of plasma triacylglycerols was studied. The test ration contained 25% beetpulp in the dietary dry matter. The feeding of beet pulp lowered plasma triacylglycerol concentrations (p = 0.058) in the fasting state and raised the activity of heparin‐released lipoprotein lipase (LPL) (p = 0.059) and the concentration of HDL2cholesterol (p = 0.058). In the fasting state, the plasma concentrations of free fatty acids (p = 0.073) and those of β‐hydroxybutyrate (p = 0.043) were increased after feeding beetpulp. At 3 h after feed intake, consumption of beetpulp instead of glucose had produced higher plasma concentrations of both glucose (p = 0.014) and insulin (p = 0.040). It is suggested that beetpulp ingestion activates LPL followed by a drop in plasma triacylglycerols.
A finite element analysis of cracked square plates and bars under antiplane loading
Authors: POOK L. P.
Published: May 2003

ABSTRACT Finite element analyses were carried out on cracked 20 mm square plates and bars ranging in thickness from 2.5 mm to a length of 60 mm. The crack extended from the middle of one side of the square to its centre, and was modelled as a narrow, parallel‐sided notch with a semicircular tip. An antiplane loading was applied to the side containing the crack. An infinitely long bar under the antiplane loading used is in pure Mode III. It was found that the central portions of 40, 56 mm and 60 mm long bars were in pure Mode III, and also that KIII was approximately constant. These central portions were therefore representative of an infinitely long bar. Towards the ends of a bar KIII decreased. At the ends of a bar corner point effects meant that Mode II stress intensity factors and displacements were induced in the corner region. The size of the corner region was independent of bar length. In the 2.5, 5 and 10 mm thick plates out of plane bending means that the antiplane loading became a mixed Mode II and Mode III loading. At a centre line KII is zero by symmetry. Behaviour in the corner region was a function of plate thickness. For both plates and bars, as has been predicted theoretically, the ratio KII/KIII tends to a constant value as a surface is approached. For a thickness of 20 mm, that is a 20‐mm cube, behaviour represents a transition between plate and bar behaviour.
Typical varicella zoster (ophthalmicus) in an HIV‐infected person
Authors: Sehgal Virendra N , Kumar Sunil , Jain Sanjiv , Bhattacharya Sumit N
Published: May 2003

A typical varicella zoster (ophthalmicus) in an incidentally HIV‐infected person is reported in a young man. It was characterized by tense, grouped, vesiculobullous eruptions on a brick‐red base. The diagnosis was substantiated by demonstration of swollen epidermal (balloon) cells with a nucleus/several nuclei containing inclusion bodies. Reticular degeneration was apparant.
Functioning of child maltreating families: lack of resources for caring within the family
Authors: Paavilainen Eija , Åstedt‐Kurki Päivi
Published: May 2003

The purpose of this study was to develop a preliminary theoretical model of functioning of child maltreating families. Child maltreatment was defined as physical, psychological or sexual abuse or neglect caused by the child's primary caregivers. The aim was to generate knowledge needed in developing understanding and the care of these families. Data were collected using interviews with open‐ended questions from child maltreating families (n = 20). Transcribed interviews were analysed by using grounded theory and its constant comparative method. The categories of family functioning included structural factors of the family, relationships between family members, relationships outside the family, family strengths, and risk factors and manifestations of maltreatment. The relationships that emerged between these categories included conflicts and negative circles of family life and the effects of child maltreatment on the family. Lack of resources for caring within the family emerged as the core category which described the phenomenon in general and was connected to all other categories of family functioning. The findings can be useful in developing the care of child maltreating families, in nursing education and in preventing child maltreatment.
Nurses’ experiences of interactions with family members in intensive care units
Authors: Söderström Ing‐Mari , Benzein Eva , Saveman Britt‐Inger
Published: May 2003

The purpose of this study was to describe nurses’ experiences of interactions with family members in intensive care units. Ten experienced Registered Nurses were interviewed, and the interview text was qualitatively analysed by its content. Nursing of families was experienced as an essential, necessary and demanding task, and no systematic assessment and intervention with families were talked about. Two categories emerged from nurses’ descriptions: inviting and noninviting interactions between nurses and family members. Inviting interactions were considered when family members were seen as important in the nursing care. The nurses used themselves as instruments to create contact and felt confident working with the family members. Thereby the nurses were forced to reflect on their way of caring and received positive responses from family members. In noninviting interactions, medical and technical tasks were considered to be most important and the nurses considered themselves as experts. They expressed having little time for family members and described being afraid of coming too close to them and having problems with creating relationships. Further research, including direct observations of interactions between nurses and family members, is needed.
Clastogenic effect of bracken fern (Pteridium aquilinum v. arachnoideum) diet in peripheral lymphocytes of human consumers: preliminary data
Authors: Recouso R. C. , Santos R. C. Stocco dos , Freitas R. , Santos R. C. , Freitas A. C. de , Brunner O. , Beçak W. , Lindsey C. J.
Published: May 2003

Ingestion of bracken fern (Pteridium aquilinum v. arachnoideum) is associated with digestive tract cancer in different regions of Japan, Venezuela and Brazil. In view of reports that dietary bracken fern causes chromosomal instability in cattle, the clastogenic effect of bracken fern was investigated, in a preliminary study, in peripheral lymphocytes obtained from habitual consumers and a control group of non‐consumers, which were carefully investigated about cancer history or family cancer history, negative in both cases, using protocols comparable to those previously described in studies in cattle raised on bracken pastures. Cytogenetic analysis showed significant increased levels of chromosomal abnormalities, such as chromatid breaks, in cultured peripheral lymphocytes of the consumer group. There was no correlation with subjects, gender, smoking habits or alcohol consumption, and the only correlation was with prolonged exposure to dietary bracken.
Toll–Like Receptor 4 Mediates Inflammatory Signaling by Bacterial Lipopolysaccharide in Human Hepatic Stellate Cells
Authors: Paik Yong-Han , Schwabe Robert F. , Bataller Ramón , Russo Maria P. , Jobin Christian , Brenner David A.
Published: May 2003

Bacterial lipopolysaccharide (LPS) stimulates Kupffer cells and participates in the pathogenesis of alcohol–induced liver injury. However, it is unknown whether LPS directly affects hepatic stellate cells (HSCs), the main fibrogenic cell type in the injured liver. This study characterizes LPS–induced signal transduction and proinflammatory gene expression in activated human HSCs. Culture–activated HSCs and HSCs isolated from patients with hepatitis C virus–induced cirrhosis express LPS–associated signaling molecules, including CD14, toll–like receptor (TLR) 4, and MD2. Stimulation of culture–activated HSCs with LPS results in a rapid and marked activation of NF–κB, as assessed by in vitro kinase assays for IκB kinase (IKK), IκBα steady–state levels, p65 nuclear translocation, NF–κB–dependent luciferase reporter gene assays, and electrophoretic mobility shift assays. Lipid A induces NF–κB activation in a similar manner. Both LPS– and lipid A–induced NF–κB activation is blocked by preincubation with either anti–TLR4 blocking antibody (HTA125) or Polymyxin B. Lipid A induces NF–κB activation in HSCs from TLR4–sufficient (C3H/OuJ) mice but not from TLR4–deficient (C3H/HeJ) mice. LPS also activates c–Jun N–terminal kinase (JNK), as assessed by in vitro kinase assays. LPS up–regulates IL–8 and MCP–1 gene expression and secretion. LPS–induced IL–8 secretion is completely inhibited by the IκB super repressor (Ad5IκB) and partially inhibited by a specific JNK inhibitor, SP600125. LPS also up–regulates cell surface expression of ICAM–1 and VCAM–1. In conclusion, human activated HSCs utilize components of TLR4 signal transduction cascade to stimulate NF–κB and JNK and up–regulate chemokines and adhesion molecules. Thus, HSCs are a potential mediator of LPS–induced liver injury.
Angiopoietins and Tie–2 Expression in Angiogenesis and Proliferation of Human Hepatocellular Carcinoma
Authors: Mitsuhashi Noboru , Shimizu Hiroaki , Ohtsuka Masayuki , Wakabayashi Yasuo , Ito Hiroshi , Kimura Fumio , Yoshidome Hiroyuki , Kato Atsushi , Nukui Yuji , Miyazaki Masaru
Published: May 2003

Human hepatocellular carcinoma (HCC) is a hypervascular tumor but the mechanisms underlying the process of angiogenesis are not fully understood. Angiopoietins (Ang) have been recently identified as ligands for Tie–2 receptor and are thought to be important factors in vascular maturation and stability during angiogenesis. In this study, we investigated the expression of Ang–1, Ang–2, Tie–2, and vascular endothelial growth factor (VEGF) in surgically resected specimens from 46 patients with HCC to determine their potential role in tumor angiogenesis and its progression. VEGF messenger RNA (mRNA) was significantly up–regulated in HCC compared to normal liver tissue from patients with hepatic metastases. No differences were found between HCC and adjacent liver tissue. Meanwhile, Ang–2 mRNA expression in HCC was significantly increased when compared to adjacent liver tissue. On the other hand, Ang–1 and Tie–2 mRNA expression in HCC was not different from that in adjacent liver tissue. Immunohistochemical staining also showed increased Ang–2 protein in HCC. Furthermore, a high Ang–2/1 mRNA ratio in HCC was closely associated with tumor portal vein invasion, tumor diameter, and the microvessel density level as assessed by CD34 immunostaining. With regard to prognosis, the survival time for patients in the high Ang–2/1 mRNA ratio group was significantly poorer when compared with the low Ang–2/1 mRNA ratio group. In conclusion, an increased expression of Ang–2/1 in the presence of VEGF may play a critical role in promoting tumor angiogenesis and progression in human HCC.
Adam12 in Human Liver Cancers: Tgf–β–Regulated Expression in Stellate Cells Is Associated With Matrix Remodeling
Authors: Le Pabic Hélène , Bonnier Dominique , Wewer Ulla M. , Coutand Alexandre , Musso Orlando , Baffet Georges , Clément Bruno , Théret Nathalie
Published: May 2003

“A disintegrin and metalloproteinases” (ADAMs) form a family of cell–surface glycoproteins with potential protease and cell–adhesion activities. We have investigated ADAM expression in human liver cancers and their regulation by several cytokines involved in liver injury. Using degenerative RT–PCR, cDNA encoding sequences for ADAM9 and ADAM12 were identified in human activated hepatic stellate cells (HSCs). Northern blot analyses showed that HSCs, but not hepatocytes, expressed transcripts for ADAM9 messenger RNA (mRNA) and both the long and short forms of ADAM12. This expression was associated with the transition from quiescent to activated state of rat HSCs and markedly increased in human livers with cirrhosis. ADAM12 but not ADAM9 expression was up–regulated by transforming growth factor β (TGF–β) in human activated HSCs. The PI3K inhibitor LY294002 and the mitogen–activated protein kinase kinase (MEK) inhibitor UO126 prevented ADAM12 induction by TGF–β, suggesting the involvement of PI3K and MEK activities. In vivo, the steady–state of both ADAM9 and ADAM12 mRNA levels was nearly undetectable in both normal livers and benign tumors and increased in hepatocellular carcinomas (up to 3– and 6–fold, respectively) and liver metastases from colonic carcinomas (up to 40– and 60–fold, respectively). The up–regulation of both ADAM9 and ADAM12 was correlated with an increase in matrix metalloproteinase 2 expression and activity. In conclusion, in liver cancers ADAM9 and ADAM12 expression is associated with tumor aggressiveness and progression.
Scaling behavior of random knots
Authors: Dobay Akos , Dubochet Jacques , Millett Kenneth , Sottas Pierre-Edouard , Stasiak Andrzej
Published: May 2003

Using numerical simulations we investigate how overall dimensions of random knots scale with their length. We demonstrate that when closed non-self-avoiding random trajectories are divided into groups consisting of individual knot types, then each such group shows the scaling exponent of ≈0.588 that is typical for self-avoiding walks. However, when all generated knots are grouped together, their scaling exponent becomes equal to 0.5 (as in non-self-avoiding random walks). We explain here this apparent paradox. We introduce the notion of the equilibrium length of individual types of knots and show its correlation with the length of ideal geometric representations of knots. We also demonstrate that overall dimensions of random knots with a given chain length follow the same order as dimensions of ideal geometric representations of knots.
Mutational analysis of predicted interactions between the catalytic and P domains of prohormone convertase 3 (PC3/PC1)
Authors: Ueda Kazuya , Lipkind Gregory M. , Zhou An , Zhu Xiaorong , Kuznetsov Andrey , Philipson Louis , Gardner Paul , Zhang Chunling , Steiner Donald F.
Published: May 2003

The subtilisin-like prohormone convertases (PCs) contain an essential downstream domain (P domain), which has been predicted to have a β-barrel structure that interacts with and stabilizes the catalytic domain (CAT). To assess possible sites of hydrophobic interaction, a series of mutant PC3–enhanced GFP constructs were prepared in which selected nonpolar residues on the surface of CAT were substituted by the corresponding polar residues in subtilisin Carlsberg. To investigate the folding potential of the isolated P domain, signal peptide–P domain–enhanced GFP constructs with mutated and/or truncated P domains were also made. All mutants were expressed in βTC3 cells, and their subcellular localization and secretion were determined. The mutants fell into three main groups: (
i
) Golgi/secreted, (
ii
) ER/nonsecreted, and (
iii
) apoptosis inducing. The destabilizing CAT mutations indicate that the side chains of V292, T328, L351, Q408, H409, V412, and F441 and nonpolar fragments of the side chains of R405 and W413 form a hydrophobic patch on CAT that interacts with the P domain. We also have found that the P domain can fold independently, as indicated by its secretion. Interestingly, T594, which is near the P domain C terminus, was not essential for P domain secretion but is crucial for the stability of intact PC3. T594V produced a stable enzyme, but T594D did not, which suggests that T594 participates in important hydrophobic interactions within PC3. These findings support our conclusion that the catalytic and P domains contribute to the folding and thermodynamic stability of the convertases through reciprocal hydrophobic interactions.
The two-component PhoR-PhoP system controls both primary metabolism and secondary metabolite biosynthesis in
Streptomyces lividans
Authors: Sola-Landa A. , Moura R. S. , Martín J. F.
Published: May 2003

The biosynthesis of most secondary metabolites in different bacteria is strongly depressed by inorganic phosphate. The two-component
phoR-phoP
system of
Streptomyces lividans
has been cloned and characterized. PhoR showed all of the characteristics of the membrane-bound sensor proteins, whereas PhoP is a member of the DNA-binding OmpR family. Deletion mutants lacking
phoP
or
phoR-phoP
, were unable to grow in minimal medium at low phosphate concentration (10 μM). Growth was fully restored by complementation with the
phoR-phoP
genes. Both
S. lividans
Δ
phoP
and Δ
phoR-phoP
deletion mutants were unable to synthesize extracellular alkaline phosphatase (AP) as shown by immunodetection with anti-AP antibodies and by enzymatic analysis, suggesting that the PhoR-PhoP system is required for expression of the AP gene (
phoA
). Synthesis of AP was restored by complementation of the deletion mutants with
phoR-phoP
. The biosynthesis of two secondary metabolites, actinorhodin and undecylprodigiosin, was significantly increased in both solid and liquid medium in the Δ
phoP
or Δ
phoR-phoP
deletion mutants. Negative phosphate control of both secondary metabolites was restored by complementation with the
phoR-phoP
cluster. These results prove that expression of both
phoA
and genes implicated in the biosynthesis of secondary metabolites in
S. lividans
is regulated by a mechanism involving the two-component PhoR-PhoP system.
Phototropin is the blue-light receptor that controls multiple steps in the sexual life cycle of the green alga
Chlamydomonas
reinhardtii
Authors: Huang Kaiyao , Beck Christoph F.
Published: May 2003

Blue light as an environmental cue plays a pivotal role in controlling the progression of the sexual life cycle in the green alga
Chlamydomonas reinhardtii
. Phototropin was considered a prime candidate for the blue-light receptor involved. By using the RNA interference method, knockdown strains with reduced phototropin levels were isolated. Those with severely reduced levels of this photoreceptor were partially impaired in three steps of the life cycle: in gametogenesis, the maintenance of mating ability, and the germination of zygotes. These observations suggest that phototropin is the principal sensory molecule used by this alga for the control of its life cycle by light.
A high-frequency polymorphism in exon 6 of the CD45 tyrosine phosphatase gene (PTPRC) resulting in altered isoform expression
Authors: Stanton Tara , Boxall Sally , Hirai Kouzo , Dawes Ritu , Tonks Susan , Yasui Tomoyo , Kanaoka Yasushi , Yuldasheva Nadira , Ishiko Osamu , Bodmer Walter , Beverley Peter C. L. , Tchilian Elma Z.
Published: May 2003

CD45 (leukocyte common) antigen is a hemopoietic cell-specific tyrosine phosphatase essential for antigen receptor-mediated signaling in lymphocytes. The molecule undergoes complex alternative splicing in the extracellular domain, and different patterns of CD45 splicing are associated with distinct functions. Lack of CD45 leads to severe combined immunodeficiency, and alterations of CD45 splicing, because of a polymorphism in exon 4, have been associated with altered immune function. Here we describe a polymorphism in exon 6 (A138G) of the gene encoding CD45 that interferes with alternative splicing. The polymorphism results in an amino acid substitution of Thr-47 to Ala in exon 6, a potential O- and N-linked glycosylation site. This exon 6 A138G variant is present at a frequency of 23.7% in the Japanese population but is absent in Caucasoids. Peripheral blood T cells from individuals carrying the A138G variant show a significant decrease in the proportion of cells expressing the A, B, and C CD45 isoforms and a high frequency of CD45R0+ cells. These phenotypic alterations in the A138G carriers may lead to changes in ligand binding, homodimerization of CD45, and altered immune responses, suggesting the involvement of natural selection in controlling the A138G carrier frequency.
A Wnt- and β-catenin-dependent pathway for mammalian cardiac myogenesis
Authors: Nakamura Teruya , Sano Motoaki , Songyang Zhou , Schneider Michael D.
Published: May 2003

Acquisition of a cardiac fate by embryonic mesodermal cells is a fundamental step in heart formation. Heart development in frogs and avians requires positive signals from adjacent endoderm, including bone morphogenic proteins, and is antagonized by a second secreted signal, Wnt proteins, from neural tube. By contrast, mechanisms of mesodermal commitment to create heart muscle in mammals are largely unknown. In addition, Wnt-dependent signals can involve either a canonical β-catenin pathway or other, alternative mediators. Here, we tested the involvement of Wnts and β-catenin in mammalian cardiac myogenesis by using a pluripotent mouse cell line (P19CL6) that recapitulates early steps for cardiac specification. In this system, early and late cardiac genes are up-regulated by 1% DMSO, and spontaneous beating occurs. Notably,
Wnt3A
and
Wnt8A
were induced days before even the earliest cardiogenic transcription factors. DMSO induced biochemical mediators of Wnt signaling (decreased phosphorylation and increased levels of β-catenin), which were suppressed by Frizzled-8/Fc, a soluble Wnt antagonist. DMSO provoked T cell factor-dependent transcriptional activity; thus, induction of Wnt proteins by DMSO was functionally coupled. Frizzled-8/Fc inhibited the induction of cardiogenic transcription factors, cardiogenic growth factors, and sarcomeric myosin heavy chains. Likewise, differentiation was blocked by constitutively active glycogen synthase kinase 3β, an intracellular inhibitor of the Wnt/β-catenin pathway. Conversely, lithium chloride, which inhibits glycogen synthase kinase 3β, and Wnt3A-conditioned medium up-regulated early cardiac markers and the proportion of differentiated cells. Thus, Wnt/β-catenin signaling is activated at the inception of mammalian cardiac myogenesis and is indispensable for cardiac differentiation, at least in this pluripotent model system.
Nifedipine facilitates neurotransmitter release independently of calcium channels
Authors: Hirasawa Michiru , Pittman Quentin J.
Published: May 2003

Nifedipine, a drug used for treatment of hypertension and angina, exerts its effect by calcium channel blockade and nitric oxide production. We report here a previously uncharacterized action of nifedipine on central synaptic transmission that may partially explain its side effects. Nifedipine causes a long-lasting facilitation of tetrodotoxin-insensitive spontaneous glutamate release. This effect is independent of its L-type calcium channel blocking effect, and is not mimicked by other dihydropyridines such as nimodipine, nicardipine, or Bay K 8644. The effect was dose dependent, with EC
50
of 7.8 μM, with the lowest effective dose being 100 nM, a clinically relevant dose. At 10 μM, the increase is 14.7-fold. This effect is largely calcium-independent, because Cd
2+
, thapsigargin, or BAPTA-AM [1,2-bis(2-aminophenoxy)ethane-
N
,
N
,
N
′,
N
′-tetraacetic acid-acetoxymethyl ester] did not inhibit the nifedipine effect. Thus, nifedipine seems to act on the release process downstream of calcium entry or release. Protein kinases A or C do not mediate its effect, because it is not blocked by inhibitors of these kinases. Our finding indicates that nifedipine may be a useful tool as a secretagogue to directly target the release process, but raises caution for its use as an L-type calcium channel blocker.
Keratin 8 and 18 mutations are risk factors for developing liver disease of multiple etiologies
Authors: Ku Nam-On , Darling Jama M. , Krams Sheri M. , Esquivel Carlos O. , Keeffe Emmet B. , Sibley Richard K. , Lee Young Moo , Wright Teresa L. , Omary M. Bishr
Published: May 2003

Keratin 8 and 18 (K8/K18) mutations are found in patients with cryptogenic cirrhosis, but the role of keratin mutations in noncryptogenic cirrhosis and the incidence of keratin mutations in the general population are not known. We screened for K8/K18 mutations in genomic DNA isolated from 314 liver explants of patients who primarily had noncryptogenic cirrhosis, and from 349 blood bank volunteers. Seven unique K8/K18 mutations were found in 11 independent patients with biliary atresia, hepatitis B/C, alcohol, primary biliary cirrhosis, and fulminant hepatitis. Seven of the 11 patients had mutations previously described in patients with cryptogenic cirrhosis: K8 Tyr-53 → His, K8 Gly-61 → Cys, and K18 His-127 → Leu. The four remaining patients had mutations at one K8 and three other K18 new sites. Of the 349 blood bank control samples, only one contained the Tyr-53 → His and one the Gly-61 → Cys K8 mutations (
P
< 0.004 when comparing cirrhosis versus control groups). Two additional mutations were found in both the liver disease and blood bank groups and, hence, likely represent polymorphisms. Livers with keratin mutations had cytoplasmic filamentous deposits that were less frequent in livers without the mutations (
P
= 0.03). Therefore, K8/K18 are likely susceptibility genes for developing cryptogenic and noncryptogenic forms of liver disease.
Catalytic and structural role of the metal ion in dUTP pyrophosphatase
Authors: Mustafi Devkumar , Bekesi Angela , Vertessy Beata G. , Makinen Marvin W.
Published: May 2003

The metal ion dependence of the catalytic activity of recombinant
Escherichia coli
dUTP pyrophosphatase (dUTPase), an essential enzyme preventing incorporation of uracil into DNA, has been investigated by steady-state kinetic, electron paramagnetic resonance, and electron nuclear double resonance methods. Values of
k
cat
and
k
cat
/
K
m
were 4.5 ± 0.1 s
−1
and 0.49 ± 0.1 × 10
6
M
−1
⋅s
−1
in the absence of divalent metal ions, 14.7 ± 2.2 s
−1
and 25.1 ± 7.4 × 10
6
M
−1
⋅s
−1
in the presence of Mg
2+
or Mn
2+
, and 24.2 ± 3.6 s
−1
and 2.4 ± 0.7 × 10
6
M
−1
⋅s
−1
when supported by VO
2+
or bis(acetylacetonato)oxovanadium(IV). Binding of VO
2+
to the enzyme in the presence of dUDP, a nonhydrolyzable substrate analog, was specific and competitive with Mg
2+
. Electron paramagnetic resonance spectra of the ternary enzyme–VO
2+
-chelate–dUDP complex revealed a pattern of
31
P superhyperfine coupling specifying two structurally equivalent phosphate groups equatorially coordinated to the VO
2+
ion. Proton electron nuclear double resonance spectra revealed an equatorial acetylacetonate ligand, indicating that one of the organic ligands had been displaced. By molecular graphics modeling, we show that the diphosphate group of enzyme-bound dUDP is sterically accessible to a hemi-chelate form of VO
2+
. We propose a similar location compatible with all kinetic and spectroscopic results to account for the reactivity of VO
2+
and the VO
2+
-chelate in dUTP hydrolysis. In this location the metal ion could promote an ordered conformation of the C-terminal fragment that is obligatory for catalysis but dynamically flexible in the free enzyme.
Linkage disequilibrium in human populations
Authors: Lonjou Christine , Zhang Weihua , Collins Andrew , Tapper William J. , Elahi Eiram , Maniatis Nikolas , Morton Newton E.
Published: May 2003

Whereas the human linkage map appears on limited evidence to be constant over populations, maps of linkage disequilibrium (LD) vary among populations that differ in gene history. The greatest difference is between populations of sub-Saharan origin and populations remotely derived from Africa after a major bottleneck that reduced their heterozygosity and altered their Malecot parameters, increasing the intercept
M
that reflects association in founders and decreasing the exponential decline ɛ. Variation among populations within this ethnic dichotomy is much smaller. These observations validate use of a cosmopolitan LD map based on a sizeable sample representing a large population reliably typed for markers at high density. Then an LD map for a region or isolate within an ethnic group may be created by fitting the sample LD to the cosmopolitan map, estimating Malecot parameters simultaneously. The cosmopolitan map scaled by ɛ recovers 95% of the information that a local map at the same density gives and therefore more than the information in a low-resolution local map. Relative to a Eurasian cosmopolitan map the scaling factors are estimated to be 0.82 for isolates of European descent, 1.53 for Yorubans, and 1.74 for African Americans. These observations are consistent with a common bottleneck (perhaps but not necessarily speciation) ≈173,500 years ago, if the bottleneck associated with migration out of Africa was 100,000 years ago. Eurasian populations (especially isolates with numerous cases) are efficient for genome scans, and populations of recent African origin (such as African Americans) are efficient for identification of causal polymorphisms within a candidate sequence.
NMR structure of a complex containing the TFIIF subunit RAP74 and the RNA polymerase II carboxyl-terminal domain phosphatase FCP1
Authors: Nguyen Bao D. , Abbott Karen L. , Potempa Krzysztof , Kobor Michael S. , Archambault Jacques , Greenblatt Jack , Legault Pascale , Omichinski James G.
Published: May 2003

FCP1 [transcription factor II
F
(TFIIF)-associated
c
arboxyl-terminal domain (CTD)
p
hosphatase] is the only identified phosphatase specific for the phosphorylated CTD of RNA polymerase II (RNAP II). The phosphatase activity of FCP1 is enhanced in the presence of the large subunit of TFIIF (RAP74 in humans). It has been demonstrated that the CTD of RAP74 (cterRAP74; residues 436–517) directly interacts with the highly acidic CTD of FCP1 (cterFCP; residues 879–961 in human). In this manuscript, we have determined a high-resolution solution structure of a cterRAP74/cterFCP complex by NMR spectroscopy. Interestingly, the cterFCP protein is completely disordered in the unbound state, but forms an α-helix (H1′; E945–M961) in the complex. The cterRAP74/cterFCP binding interface relies extensively on van der Waals contacts between hydrophobic residues from the H2 and H3 helices of cterRAP74 and hydrophobic residues from the H1′ helix of cterFCP. The binding interface also contains two critical electrostatic interactions involving aspartic acid residues from H1′ of cterFCP and lysine residues from both H2 and H3 of cterRAP74. There are also three additional polar interactions involving highly conserved acidic residues from the H1′ helix. The cterRAP74/cterFCP complex is the first high-resolution structure between an acidic residue-rich domain from a holoenzyme-associated regulatory protein and a general transcription factor. The structure defines a clear role for both hydrophobic and acidic residues in protein/protein complexes involving acidic residue-rich domains in transcription regulatory proteins.
Tauroursodeoxycholic acid reduces apoptosis and protects against neurological injury after acute hemorrhagic stroke in rats
Authors: Rodrigues Cecilia M. P. , Solá Susana , Nan Zhenhong , Castro Rui E. , Ribeiro Paulo S. , Low Walter C. , Steer Clifford J.
Published: May 2003

Tauroursodeoxycholic acid (TUDCA), an endogenous bile acid, modulates cell death by interrupting classic pathways of apoptosis. Intracerebral hemorrhage (ICH) is a devastating acute neurological disorder, without effective treatment, in which a significant loss of neuronal cells is thought to occur by apoptosis. In this study, we evaluated whether TUDCA can reduce brain injury and improve neurological function after ICH in rats. Administration of TUDCA before or up to 6 h after stereotaxic collagenase injection into the striatum reduced lesion volumes at 2 days by as much as 50%. Apoptosis was ≈50% decreased in the area immediately surrounding the hematoma and was associated with a similar inhibition of caspase activity. These changes were also associated with improved neurobehavioral deficits as assessed by rotational asymmetry, limb placement, and stepping ability. Furthermore, TUDCA treatment modulated expression of certain Bcl-2 family members, as well as NF-κB activity. In addition to its protective action at the mitochondrial membrane, TUDCA also activated the Akt-1/protein kinase Bα survival pathway and induced Bad phosphorylation at Ser-136. In conclusion, reduction of brain injury underlies the wide-range neuroprotective effects of TUDCA after ICH. Thus, given its clinical safety, TUDCA may provide a potentially useful treatment in patients with hemorrhagic stroke and perhaps other acute brain injuries associated with cell death by apoptosis.
Long-term memory for a life on the move
Authors: Mettke-Hofmann Claudia , Gwinner Eberhard
Published: May 2003

Evidence is accumulating that cognitive abilities are shaped by the specific ecological conditions to which animals are exposed. Long-distance migratory birds may provide a striking example of this. Field observations have shown that, at least in some species, a substantial proportion of individuals return to the same breeding, wintering, and stopover sites in successive years. This observation suggests that migrants have evolved special cognitive abilities that enable them to accomplish these feats. Here we show that memory of a particular feeding site persisted for at least 12 months in a long-distance migrant, whereas a closely related nonmigrant could remember such a site for only 2 weeks. Thus, it seems that the migratory lifestyle has influenced the learning and memorizing capacities of migratory birds. These results build a bridge between field observations suggesting special memorization feats of migratory birds and previous neuroanatomical results from the same two species indicating an increase in relative hippocampal size from the first to the second year of life in the migrant but not in the nonmigrant.