bluuebunny/crossref_metadata_2025 huggingface dataset:
Grading of soft tissue sarcomas: the challenge of providing precise information in an imprecise world
Authors: Deyrup A T , Weiss S W
Published: December 2005

By identifying patients at greatest risk for distant metastasis and, hence, most likely to benefit from adjuvant therapy, the grading of sarcomas has been one of the most important contributions pathologists have made to the treatment of sarcomas. Over the years, many grading schemes have been proposed and validated as efficacious. The three‐tier system proposed by the French Federation of Cancer Centres is precisely defined, easy to use, and is the most widely employed. However, no system performs perfectly on all sarcomas. Sarcomas that do not lend themselves well to grading include (i) those in which grade provides no incremental information over histological subtypes (e.g. well‐differentiated liposarcoma/atypical lipomatous neoplasm, Ewing's sarcoma); (ii) tumours traditionally considered ‘ungradable’ (e.g. epithelioid sarcoma, clear cell sarcoma, angiosarcoma); and (iii) sarcomas that customarily have been graded but in which grade has recently been shown not to correlate well with outcome (e.g. malignant peripheral nerve sheath tumour). Consequently, several sarcoma‐specific risk stratification schemes have been proposed. The future may well witness a synthesis of these two approaches. Nomograms, which incorporate clinical, histological and demographic findings, have proved accurate in predicting disease‐specific survival in sarcomas. Diagnosis and grading are increasingly based on tissue obtained by core needle biopsy, which poses new challenges for pathologists, particularly if neoadjuvant therapy is to be given. Grading on needle biopsies may require a two‐tier grading system (i.e. low versus high grade) and a close dialogue with clinicians to resolve ambiguities.
Classification of pleomorphic sarcomas: where are we now?
Authors: Tos A P Dei
Published: December 2005

Until a decade ago, so‐called pleomorphic and storiform malignant fibrous histiocytoma (MFH) represented the most frequently diagnosed sarcoma, accounting for approximately 40% of adult mesenchymal malignancies. However, the latest World Health Organization classification of soft tissue tumours considers MFH a synonym for undifferentiated pleomorphic sarcoma. Historically, the term MFH was introduced in the medical literature in 1963 by Ozzello, O'Brien and Stout, on the basis of the acquisition of phagocytic properties observed in cultured fibroblasts. The existence of MFH as a well‐defined clinicopathological entity became rapidly very popular and by the mid 1980s MFH represented the most common sarcoma in adults. With the advent of electron microscopy, immunohistochemistry and molecular genetics, it became clear that the so‐called ‘facultative fibroblast’ theory had no scientific grounds and, in 1992, a milestone paper eventually brought attention to the concept that MFH merely represented a morphological pattern shared by a wide variety of poorly differentiated malignant neoplasms, which include specific subtypes of pleomorphic sarcomas. Currently, accurate subclassification of pleomorphic sarcomas is mandatory as it enables recognition of non‐sarcomatous lesions as well as pleomorphic neoplasms not associated with aggressive behaviour. Furthermore, as myogenic differentiation predicts aggressive clinical behaviour among pleomorphic sarcomas, precise histotyping allows prognostic stratification of patients.
Oral, more than transdermal, oestrogen therapy lowers asymmetric dimethylarginine in healthy postmenopausal women: a randomized, placebo‐controlled study
Authors: VERHOEVEN M. O. , HEMELAAR M. , MOOREN M. J. VAN DER , KENEMANS P. , TEERLINK T.
Published: December 2005

Objective.  To compare the effects of oral and transdermal hormone therapy (HT) on asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, in postmenopausal women.

Design.  In a multicentre, placebo‐controlled, double‐blind study, 152 hysterectomized healthy women were randomized to receive daily transdermal 17β‐oestradiol (tE2, n = 33), or oral micronized 17β‐oestradiol either unopposed (oE2, n = 37), or continuous combined with gestodene (oE2 + G, n = 33), or placebo (n = 49) for 13, 28‐day treatment cycles. Plasma concentrations of ADMA, arginine and symmetric dimethylarginine (SDMA) were measured at baseline and in treatment cycles 4 and 13 with a high‐performance liquid chromatography method.

Results.  After 13 cycles all active treatment groups showed a significant reduction in ADMA compared with placebo: tE2, −4.0% (95% CI: −7.5 to −0.6%); oE2, −7.7% (95% CI: −10.9 to −4.4%) and oE2 + G, −7.5% (95% CI: −10.8 to −4.3%). ancova showed a significantly larger reduction in the oral groups compared with the transdermal group (tE2 vs. oE2 and tE2 vs. oE2 + G, both P < 0.01). Oral, but not transdermal treatment, significantly reduced arginine compared with placebo. All active treatments reduced SDMA; however, this was only statistically significant in the oE2 group.

Conclusion.  Reduction of ADMA was more pronounced after oral than after tE2 administration. Adding gestodene to oral 17β‐oestradiol did not alter the reduction of ADMA. The clinical implications of these findings remain uncertain; however, the decrease of ADMA by 17β‐oestradiol could be a key phenomenon in the modulation of nitric oxide synthesis by postmenopausal HT.
The DnaK chaperone machinery converts the native FlhD2C2 hetero‐tetramer into a functional transcriptional regulator of flagellar regulon expression in Salmonella
Authors: Takaya Akiko , Matsui Mari , Tomoyasu Toshifumi , Kaya Michihiro , Yamamoto Tomoko
Published: December 2005

The DnaK chaperone binds non‐specifically to many unfolded polypeptides and also binds selectively to specific substrates. Although its involvement in targeting the unfolded polypeptides to assist proper folding is well documented, less is known about its role in targeting the folded polypeptides. We demonstrate that DnaK regulates the expression of the Salmonella flagellar regulon by modulating the FlhD and FlhC proteins, which function as master regulators at the apex of a transcription hierarchy comprising three classes of genes. FlhD and FlhC form an FlhD2C2 complex that activates σ70 promoter of class 2 genes. In ΔdnaK cells, FlhD and FlhC proteins seemed to be assembled into hetero‐tetrameric FlhD2C2 but the complex was not fully active in class 2 gene transcription, suggesting that the DnaK chaperone is involved in activating native FlhD2C2 complex into a regulator of flagellar regulon expression. This is the first time that involvement of the DnaK chaperone machinery in activating folded oligomerized proteins has been demonstrated.
Investigation of recombinant Schistosoma japonicum paramyosin fragments for immunogenicity and vaccine efficacy in mice
Authors: ZHANG D. M. , PAN W. Q. , QIAN L. , DUKE M. , SHEN L. H. , MCMANUS D. P.
Published: December 2005

Schistosoma japonicum paramyosin, a 97 kDa myofibrillar protein, is a recognized vaccine candidate against schistosomiasis. To improve its expression and to identify protective epitopic regions on paramyosin, the published Chinese Schistosoma japonicum paramyosin cDNA sequence was redesigned using Pichia codon usage and divided into four overlapping fragments (fragments 1, 2, 3, 4) of 747, 651, 669 and 678 bp, respectively. These gene fragments were synthesized and expressed in Pichia pastoris (fragments 2 and 3) or E. coli (fragments 1 and 4). The recombinant proteins were produced at high level and purified using a two‐step process involving Ni‐NTA affinity chromatography and gel filtration. BALB/c mice were immunized subcutaneously three times at 2‐week‐intervals with the purified proteins formulated in adjuvant Quil A. The protein fragments were highly immunogenic, inducing high, though variable, ELISA antibody titres, and each was shown to resemble native paramyosin in terms of its recognition by the anti‐fragment antibodies in Western blotting. The immunized mice were subjected to cercarial challenge 2 weeks after the final injection and promising protective efficacy in terms of significant reductions in worm burdens, worm‐pair numbers and liver eggs in the vaccinated mice resulted. There was no apparent correlation between the antibody titres generated and protective efficacy, as all fragments produced effective but similar levels of protection.
Transmission‐reducing immunity is inversely related to age in Plasmodium falciparum gametocyte carriers
Authors: DRAKELEY C. J. , BOUSEMA J. T. , AKIM N. I. J. , TEELEN K. , ROEFFEN W. , LENSEN A. H. , BOLMER M. , ELING W. , SAUERWEIN R. W.
Published: December 2005

Immunity to the sexual stages of Plasmodium falciparum is induced during natural infections and can significantly reduce the transmission of parasites to mosquitoes (transmission reducing activity; TRA) but little is known about how these responses develop with increasing age/exposure to malaria. Routinely TRA is measured in the standard membrane feeding assay (SMFA). Sera were collected from a total of 199 gametocyte carriers (median age 4 years, quartiles 2 and 9 years) near Ifakara, Tanzania; 128 samples were tested in the SMFA and generated TRA data classified as a reduction of > 50% and > 90% of transmission. TRA of > 50% was highest in young children (aged 1–2) with a significant decline with age (χ2 trend = 5·79, P = 0·016) and in logistic regression was associated with prevalence of antibodies to both Pfs230 and Pfs48/45 (OR 4·03, P = 0·011 and OR 2·43 P = 0·059, respectively). A TRA of > 90% reduction in transmission was not age related but was associated with antibodies to Pfs48/45 (OR 2·36, P = 0·055). Our data confirm that antibodies are an important component of naturally induced TRA. However, whilst a similar but small proportion of individuals at all ages have TRA > 90%, the gradual deterioration of TRA > 50% with age suggests decreased antibody concentration or affinity. This may be due to decreased exposure to gametocytes, probably as a result of increased asexual and/or gametocyte specific immunity.
Arabidopsis Aux/IAA genes are involved in brassinosteroid‐mediated growth responses in a manner dependent on organ type
Authors: Nakamura Ayako , Nakajima Naoko , Goda Hideki , Shimada Yukihisa , Hayashi Ken‐ichiro , Nozaki Hiroshi , Asami Tadao , Yoshida Shigeo , Fujioka Shozo
Published: December 2005

We examined whether auxin/indole‐3‐acetic acid (Aux/IAA) proteins, which are key players in auxin‐signal transduction, are involved in brassinosteroid (BR) responses. iaa7/axr2‐1 and iaa17/axr3‐3 mutants showed aberrant BR sensitivity and aberrant BR‐induced gene expression in an organ‐dependent manner. Two auxin inhibitors were tested in terms of BR responses. Yokonolide B inhibited BR responses, whereas p‐chlorophenoxyisobutyric acid did not inhibit BR responses. DNA microarray analysis revealed that 108 genes were up‐regulated, while only eight genes were down‐regulated in iaa7. Among the genes that were up‐ or down‐regulated in axr2, 22% were brassinolide ‐inducible genes, 20% were auxin‐inducible genes, and the majority were sensitive neither to BR nor to auxin. An inhibitor of BR biosynthesis, brassinazole, inhibited auxin induction of the DR5‐GUS gene, which consists of a synthetic auxin‐response element, a minimum promoter, and a β‐glucuronidase. These results suggest that Aux/IAA proteins function in auxin‐ and BR‐signaling pathways, and that IAA proteins function as the signaling components modulating BR sensitivity in a manner dependent on organ type.
Development of non‐agglutination microarray blood grouping
Authors: Robb J. S. , Roy D. J. , Ghazal P. , Allan J. , Petrik J.
Published: December 2005

summary.  Microarray technology provides an opportunity to monitor multiple parameters simultaneously. High‐throughput applications such as blood donation screening could greatly benefit from performing various tests on a single testing platform. Blood grouping represents one part of the donation testing complementing the screening for blood‐borne pathogens. Blood group serology traditionally exploited agglutination as the detection method. In this investigation, we have adapted blood grouping reactions to a solid‐phase microarray substrate in a non‐agglutination reaction format as an initial step in the development of a combined microarray testing platform. We have investigated immobilization of proprietary antibodies on multiple surfaces and monitored their performance under various reaction conditions. For the first time, highly specific blood grouping has been achieved on a planar microarray using directly labelled erythrocytes or a secondary labelled reagent using fluorescent signal end point readout. We have also complemented microarray data with a label‐free, surface plasmon resonance‐based Biacore platform data and used the real time quantitative measurement to rank anti‐A antibodies according to the strength of reaction with the immobilized synthetic blood group antigen A.
Post‐transfusion purpura in a patient with HPA‐1a and GPIa/IIa antibodies
Authors: Woelke C. , Eichler P. , Washington G. , Flesch B. K.
Published: December 2005

summary.  Post‐transfusion purpura is a rare bleeding disorder characterized by severe and sudden thrombocytopenia within 3–12 days after blood transfusion. Typically, preformed antibodies directed against human platelet antigens, especially HPA‐1a, are associated with the clinical symptoms. A 46‐year‐old female presenting to the hospital with acute progressive kidney insufficiency and anaemia received two units of packed red blood cells (RBC) within 2 days. On day 7, platelet count felt from 414 to 189 × 109 L−1 and 1 day later dropped to 4 × 109 L−1. Four platelet concentrates were applied without success. After serological confirmation of an HPA‐1a antibody, the patient was treated with intravenous gamma immunoglobulin (ivIgG), and the platelet count increased to normal values on day 17. In addition to the persisting HPA‐1a alloantibody, an antibody reactive with GPIa/IIa of HPA‐5a‐ and HPA‐5b‐positive platelets was detected during the acute phase of thrombocytopenia. After complete remission, the patient was transfused with four units of packed RBC from HPA‐1a‐negative donors, and platelet counts remained normal.
Preoperative autologous blood donation for bone marrow harvests: Are we wasting donors' time and blood?
Authors: Mijovic A. , Britten C. , Regan F. , Harrison J.
Published: December 2005

summary.  Predeposit autologous blood donation (PAD) is frequently offered to bone marrow donors, but its cost‐effectiveness is dubious. We assessed the impact of PAD and bone marrow donation on transfusion requirements; and the use of donated blood units in a retrospective study of 61 bone marrow donors.

The mean haemoglobin (Hb) concentration fell from 12·9 to 11·8 g dL−1 in women who predonated one unit and from 13·2 to 10·9 g dL−1 in those who predonated two units. In men who donated two units of blood, the Hb concentration decreased to 12·9 g dL−1. Bone marrow harvest led to a further decline in Hb concentration by 2·3 g dL−1 in women and by 2·4 g dL−1 in men.

The postharvest Hb fell to ≤9·0 g dL−1 in 39% of female and in 6% of the male donors; all but one of them had predonated blood.

The utilization rate of autologous units was 45·6%, with 55% of women and 24% of men receiving autologous blood. In females, 59% of transfused autologous units were given with the donor's Hb of ≥ 9·0 g dL−1; overtransfusion was even more apparent in men: 71% units were given with a Hb ≥ 10·0 g dL−1.

PAD in bone marrow donors is associated with high wastage and increases the likelihood of requiring a transfusion. We recommend that PAD should not be routinely offered to bone marrow donors.
Weak D type 2 is the most prevalent weak D type in Portugal
Authors: Araújo F. , Rodrigues M.‐J. , Monteiro F. , Chabert T. , Tavares G. , Sousa G. , Storry J. , Guimarães J.‐E.
Published: December 2005

summary.  The weak D phenotype is the most common D variant, with a frequency of 0·2–1% in Caucasian individuals. There are several weak D types, with different frequencies in European countries, which may pose serologic problems and have the potential for alloimmunization.

Samples from Portuguese individuals were tested for RhD by two or three distinct monoclonal and oligoclonal antisera, in direct agglutination tests. When discrepant results were observed, samples were tested with panels of monoclonal anti‐D by LISS‐indirect antigobulin test. Cases that reacted weakly with IgM but positive with IgG anti‐D were analysed by PCR‐sequence‐specific primers and real‐time PCR.

Ninety‐nine samples were referred after being characterized as weak D. This genotype was recognized, with a preponderance of weak D type 2 (63·6%) over type 1 (16·2%) and 3 (14·1%).

The high incidence of weak D type 2 in our population is in marked contrast to studies performed in other European populations and might be due to our sample selection criteria or ethnic variation. There are advantages in genotyping serologically depressed D samples to avoid the waste of D‐negative RBC units and the use of immunoglobulin in pregnant women, who have no risk of alloimmunization.
Histology, Immunohistochemistry and Ultrastructure of the Tonsil of the Soft Palate of the Horse
Authors: Kumar P. , Timoney J. F.
Published: December 2005

The tonsil of the soft palate was an oval, flat structure located centro‐rostrally on the oral surface of the soft palate. Its stratified squamous non‐keratinized epithelium was perforated by holes or small crypts the deeper parts of which were loosely spongiform inter‐digitated with lymphoid tissue. These unusual features have not previously been reported in tonsils of any species. Crypts and reticulated epithelium as found in the lingual and palatine tonsils were not observed. Lectins showed varying affinities for specific layers of the epithelium. M cells were not observed. A few Langerhans cells were distributed among surface epithelial cells. Lymphoid tissue was arranged loosely and in isolated lymphoid follicles in the subepithelial lamina propria mucosae. Although IgA+ cells and macrophages were proportionately more numerous the amount of lymphoid tissue was much less than in the lingual and palatine tonsils. Most of the follicular germinal centres lacked a darkly stained corona. CD4 positive were more numerous than CD8+ lymphocytes and were distributed in the parafollicular and inter‐follicular areas. Large clusters of mucus acini positive for glycogen, acidic and neutral mucopolysaccharides separated lymphoid tissue from deeply placed striated muscle. Only a few high endothelial venules were observed in the parafollicular and inter‐follicular areas. These had relatively few vesiculo vacuolar or other organelles in their high endothelial cells and few lymphocytes attaching to their walls.
Histology and Histochemistry of the Pharyngeal Cavity and Oesophagus of the Silverside Odontesthes bonariensis (Cuvier and Valenciennes)
Authors: Diaz A. O. , Escalante A. H. , García A. M. , Goldemberg A. L.
Published: December 2005

The histology of the pharyngeal cavity and oesophagus of the freshwater ‘silverside’Odontesthes bonariensis (Cuvier and Valenciennes) and the characteristics of their mucous cells were investigated. The histological characterization of its digestive wall revealed that the mucosa is thrown with longitudinal folds. The epithelium covering the folds was stratified with abundant mucous cells and gustative corpuscles, which are lacking in the oesophagus. The muscularis mucosa was absent. The submucosa presented the compactum stratum. The muscularis was organized in longitudinal and circular layers of muscular striated fibres. The serosa with a flat epithelium was located only in the oesophagus. Using histochemical procedures including methods for localization and characterization of glycoproteins (GPs), no differences were detected between the mucous cells contents of the pharyngeal cavity and those of the oesophagus. The mucous cells showed a weak periodic acid–Schiff (PAS) positive reaction in their content. The reactions for the differential analysis of sialic acids from GPs are feeble for periodic acid–Schiff at low temperature and low pH (PA*S) and KOH/PA*S and strong for periodic acid/borohydride/KOH/PAS (PA/Bh/KOH/PAS) and KOH/PA*/Bh/PAS revealing the scarce presence of C7 or C9 substituted and non‐substituted sialic acids and the abundance of C7, C8 substituted sialic acids, O‐acyl sugars and neutral sugars respectively. The results suggest that the pharyngeal cavity with the gustative corpuscles would induce the gastric secretion whereas the oesophagus is mainly involved in the transport of the food bolus to the stomach with the aid of abundant secretion of mucus. GPs secreted on the surface of the mucous cells, likely related to environmental conditions, would be involved in the lubrication, protection against abrasion and inhibition of microorganism proliferation.
The Image of Exocytosis during Neutrophils and Macrophages Phagocytic Activities in Inflammation of Mammary Gland Triggered by Experimental Staphylococcus aureus Infection
Authors: Rysanek D. , Sladek Z.
Published: December 2005

The experiments were carried out in five clinically normal virgin heifers. Before the experimental infection and at 24, 48, 72 and 168 h after the infection, respective mammary glands were rinsed with phosphate buffered saline. Neutrophils as well as macrophages underwent a classic exocytosis accompanied by translocation of lysosomal granules. The granules filled the protuberances of the plasmalemma and after the protuberances separated from the cell, they entered the extracellular space in the shape of round bodies of different sizes. After exocytosis, neutrophils displayed a smaller nucleus/cytoplasm ratio, a greater chromatin density of the nucleus, and an overall smaller size. Macrophages phagocytosed bacteria and/or neutrophils with and without signs of apoptosis (early and late apoptotic respectively) and neutrophils after exocytosis. Macrophages underwent cytolysis that was accompanied by extrusion of granules, phagosomes and phagolysosomes containing phagocytosed bacteria or neutrophils. Confluences were formed in which the process of digestion continued. Apoptosis of neutrophils gradually appeared and intensified in resolution of inflammation. The macrophages contributed to the inactivation of bacterial noxa as well as of histotoxic contents of neutrophils. Nevertheless, macrophages often underwent cytolysis at the site of inflammation.
Normovolaemia defined by central blood volume and venous oxygen saturation
Authors: Secher Niels H , Van Lieshout Johannes J
Published: December 2005

1. The intravenous administration of fluid and blood has to balance the danger of unexpected death in response to a reduction of central blood volume (CBV) against that of developing pulmonary and/or peripheral oedema.

2. The initial cardiovascular response to haemorrhage is similar to that developed in response to standing. In the upright position, adults are subjected to a reduction of CBV of approximately 0.5 L and can therefore tolerate a blood loss of approximately 1 L when supine.

3. However, volume administration directed by cardiovascular variables is seldom precise, even with integration of the bradycardia and hypotension developed when CBV decreases by approximately 30%. Immediate intervention is needed because such a reduction in CBV raises the lower limit of cerebral autoregulation to approximately 80 mmHg compared with the commonly considered value of approximately 60 mmHg with an associated risk of developing brain ischaemia and irreversible shock.

4. Alternatively, the volume load can be monitored both directly and accurately by means of thoracic electrical admittance. A functional definition of normovolaemia may be the filling of the heart that ensures cardiac output and oxygen delivery. From that perspective, supine humans are normovolaemic in that a maximal venous oxygen saturation (Svo2) is established.

5. Conversely, Svo2 decreases in the upright position and, with a blood loss of approximately 100 mL, Svo2 is reduced by 1%. It is suggested that, in supine humans and guided by Svo2, normovolaemia may be established to an accuracy of approximately 100 mL and that its adequacy is controlled by recording cerebral oxygenation.
Effects of BW245C, a prostaglandin dp receptor agonist, on systemic and regional haemodynamics in the anaesthetized rat
Authors: Koch Kristin A , Wessale Jerry L , Moreland Robert , Reinhart Glenn A , Cox Bryan F
Published: December 2005

1. Prostaglandin D (DP) receptor agonists have been shown to induce hypotension in rat models, possibly via peripheral vasodilation. However, it is not known which tissues and organs are most responsive.

2. In the present study, BW245C, a DP receptor‐selective agonist, was administered to Inactin (Sigma, St Louis, MO, USA)‐anaesthetized rats. Animals received three serial i.v. infusions (17 min each) of either BW245C (escalating doses of 0.3, 3 and 30 μg/kg; n = 6) or vehicle (6% ethanol in normal saline; n = 6). Mean arterial pressure (MAP) and heart rate were monitored continuously and regional blood flow was determined by the radionuclide‐labelled microsphere method at baseline and at the end of each infusion.

3. It was found that BW245C dose‐dependently reduced MAP; blood flow increased in forelimb skeletal muscle and skin, resulting in decreases in the regional vascular resistance (RVR) of skeletal muscle to −6 ± 13, −53 ± 11 and −68 ± 6% of baseline following 0.3, 3 and 30 μg/kg BW245C, respectively (P < 0.05 vs vehicle treatment for the two higher doses), and skin to −29 ± 8, −55 ± 8 (P < 0.05) and −30 ± 16% of baseline, respectively. Relative to vehicle, blood flow and RVR for brain, heart, lung, liver, stomach and kidney were not significantly affected by BW245C.

4. These results demonstrate that the hypotension resulting from DP receptor activation in the rat is mediated primarily through vasodilation of arterioles of skeletal muscle independent of changes in blood flow to vital organs.
Involvement of brain thromboxane A2 in hypotension induced by haemorrhage in rats
Authors: Yalcin Murat , Cavun Sinan , Yilmaz M Sertac , Cengiz Fahrunisa , Savci Vahide
Published: December 2005

1. In the present study, we aimed to determine the involvement of brain thromboxane A2 (TXA2) in blood pressure decreases evoked by acute and/or graded haemorrhage in rats.

2. Sprague‐Dawley rats were used throughout the study. Acute haemorrhage was achieved by withdrawing a total volume of 2.1 and 2.5 mL blood/100 g bodyweight over a period of 10 min. A microdialysis study was performed in a hypothalamic area to measure extracellular TXA2 levels. Graded haemorrhage was conducted successively by withdrawing carotid arterial blood (0.55 mL/100 g bodyweight) over a 10 s period four times (S1–S4) at 5 min intervals. Furegrelate (125, 250 and 500 µg), a TXA2 synthase inhibitor, was injected intracerebroventricularly (i.c.v.) 60 min before acute or graded haemorrhage was initiated. U‐46619 (0.5, 1 and 2 µg, i.c.v.), a synthetic TXA2 analogue, was administered 5 min before acute haemorrhage (2.1 mL/100 g bodyweight).

3. Acute haemorrhage produced a severe and long‐lasting decrease in blood pressure and had a tendency to increase heart rate. Both haemorrhage protocols (2.1 or 2.5 mL/100 g) generated similar approximate twofold increases in extracellular hypothalamic TXA2 levels. Intracerebroventricular furegrelate (250 µg) pretreatment completely blocked the TXA2 increases induced by acute haemorrhage. Furegrelate administration (100, 250 and 500 µg, i.c.v.) attenuated the fall in arterial pressure evoked by acute haemorrhage and caused significant increases in heart rate at all doses injected.

4. Graded haemorrhage progressively lowered arterial pressure and increased plasma vasopressin and adrenaline levels in the last period. Furegrelate‐injected rats were greatly resistant to the hypotensive effect of haemorrhage for all degrees of blood removed. Plasma adrenaline and vasopressin levels were significantly elevated in furegrelate‐pretreated rats compared with the saline‐treated group during S2–S3 and S4, respectively. U‐46619 administration caused small but statistically significant decreases in arterial pressure induced by haemorrhage.

4. The results show that acute hypotensive haemorrhage increases extracellular hypothalamic TXA2 levels. The increase in brain endogenous TXA2 levels involves a decrease in blood pressure evoked by haemorrhage because the blockade of TXA2 synthesis by furegrelate pretreatment attenuated the haemorrhagic hypotension. Increases in plasma adrenaline and vasopressin levels may mediate this effect.
Characteristic dysfunction of stunned myocardium induced by 2,3‐butanedione monoxime without ischaemia
Authors: Wang X , Guan XM , Li GP , Ren Y , Drzewiecki G , Li JK‐J , Kedem J
Published: December 2005

1. In the present study, we tested the hypothesis that, even in the absence of prior ischaemia, 2,3‐butanedione monoxime (BDM), an inhibitor of contraction at the actin–myosin level, could produce the postischaemic dysfunction characteristic of stunned myocardium. 2,3‐Butanedione monoxime was injected directly into the left anterior descending coronary artery (LAD) before and again after myocardial stunning produced by 15 min occlusion of the LAD followed by 30 min reperfusion.

2. Regional myocardial force, segment shortening and regional work were measured in both the LAD‐perfused area and the area perfused by the circumflex coronary artery, which served as a control area. Regional dysfunction produced by BDM injection or ischaemia–reperfusion was assessed quantitatively by five parameters: end‐diastolic length (EDL), shortening onset delay (delay), systolic bulge (bulge), end‐shortening time delay (EST) and tail work ratio (TWR).

3. It was found that injection of BDM into the LAD caused dyskinesis similar to that caused by occlusion–reperfusion. Both displayed elevated EDL and marked increases in delay, bulge, EST and TWR; these parameters were significantly higher in the dyskinesis caused by BDM injection. Despite dysfunctional fibre shortening, intracoronary BDM injection did not reduce regional force.

4. Thus, BDM can elicit changes similar to those characteristic of postischaemic dysfunction. Because contractility was not impaired, dysfunction was apparently caused by disrupting the association between contractile force and muscle motion.
Exogenous nitric oxide centrally enhances pulmonary reactivity in the normal and hypertensive rat
Authors: Schwenke Daryl O , Pearson James T , Tsuchimochi Hirotsugu , Mori Hidezo , Shirai Mikiyasu
Published: December 2005

1. Chronic hypoxia causes sustained pulmonary hypertension and, although impairment of the pulmonary endothelial nitric oxide (NO) pathway has been implicated, no study has described the central role of NO in modulating pulmonary vascular tone and reactivity. Centrally, NO inhibits sympathetic outflow, so we hypothesised that central NO would modulate pulmonary vascular tone and its reactivity to acute hypoxia, especially in the hypertensive state.

2. Male adult Sprague‐Dawley rats were exposed to normoxia (N) or chronic hypoxia (CH; 12% O2) for 14 days. Mean pulmonary arterial pressure (MPAP), systemic mean arterial blood pressure (MABP), cardiac output and heart rate were then measured in pentobarbitone‐anaesthetized, artificially ventilated rats. The N and CH rats were exposed to acute hypoxia (10% O2 for 4 min) after the intracerebroventricular (i.c.v.) administration of artificial cerebrospinal fluid (control) and then again after either i.c.v. NG‐nitro‐l‐arginine methyl ester (l‐NAME; 150 μg in 10 μL) or 3‐morpholino‐sydnonimine hydrochloride (SIN‐1; 100 μg in 10 μL).

3. Chronic hypoxia caused pulmonary hypertension (MPAP 20 ± 1 vs 30 ± 1 mmHg in N and CH rats, respectively) and attenuated acute hypoxic pulmonary vasoconstriction (HPV). Central inhibition of NO synthesis (by l‐NAME) did not alter baseline MPAP or the acute HPV in either N or CH rats, but it did elevate MABP. The NO donor SIN‐1 did not alter baseline MPAP, but it did enhance (N rats) or restore (CH rats) the HPV and decreased MABP.

4. The results of the present study indicate that central NO has a limited role in the tonic modulation of MPAP during normoxia and after chronic hypoxia. However, the acute HPV seems to be enhanced by exogenous NO.
Transcription of a ‘photosynthetic’ T4‐type phage during infection of a marine cyanobacterium
Authors: Clokie Martha R. J. , Shan Jinyu , Bailey Shaun , Jia Ying , Krisch Henry M. , West Stephen , Mann Nicholas H.
Published: December 2005

The transcription of S‐PM2 phage following infection of Synechococcus sp. WH7803, a marine cyanobacterium, was analysed by quantitative real‐time PCR. Unlike the distantly related coliphage T4, there were only two (early and late) instead of three (early, middle and late) classes of transcripts during the developmental cycle of the phage. This difference is consistent with the absence from the S‐PM2 genome of T4‐like middle mode promoter sequences and the transcription factors associated with their recognition. Phage S‐PM2 carries the ‘photosynthetic’ genes psbA and psbD that encode homologues of the host photosystem II proteins D1 and D2. Transcripts of the phage psbA gene appeared soon after infection and remained at high levels until lysis. Throughout the course of infection, the photosynthetic capacity of the cells remained constant. A considerable transient increase in the abundance of the host psbA transcripts occurred shortly after infection, suggesting that the host responds to the trauma of phage infection in a similar way as it does to a variety of other environmental stresses. The very substantial transcription of the phage psbA gene during the latter phase of phage infection suggests that S‐PM2 has acquired this cellular gene to ensure that D1 levels and thus photosynthesis are fully maintained until the infected cell finally lyses. Unexpectedly, transcripts of a phage‐encoded S‐layer protein gene were among the earliest and most abundant detected, suggesting that this partial homologue of a host protein plays an important role in the S‐PM2 infection process.
Detection of phosphonoacetate degradation and phnA genes in soil bacteria from distinct geographical origins suggest its possible biogenic origin
Authors: Panas Panayiotis , Ternan Nigel G. , Dooley James S. G. , McMullan Geoff
Published: December 2005

Phosphonoacetate is regarded as an antiviral xenobiotic whose mineralization can be catalysed by an enzyme, phosphonoacetate hydrolase, encoded by the phnA gene. To date the enzyme's activity has been detected in only a limited number of bacteria. Its expression has been shown to occur in a manner independent of the phosphate status of the cell, in direct contrast to the general rule of organophosphonate metabolism being under the control of the pho regulon. In this study the environmental occurrence of the phnA gene was evaluated by polymerase chain reaction amplification of DNA extracts obtained directly from various soil environments. Sensitivity of this method was improved such that a positive result was routinely obtained with soil spiked with as few as 6 colony‐forming units (cfu) per gram of soil of Pseudomonas fluorescens 23F (phnA+). When total DNA from a variety of Northern Irish, Greek and Bolivian soils was tested, all were positive for phnA. Bacteria capable of utilizing phosphonoacetate as sole carbon, energy and phosphorus source, with the release of essentially equimolar concentrations of phosphate to the culture supernatant, were isolated from all soil samples tested. Analysis of three such isolates revealed all to be species of Pseudomonas sensu stricto, possessing phosphonoacetate hydrolase activity in cell‐free extracts. Sequence determination of the phnA gene revealed a similarity of the putative protein sequences at levels of 98.3–99.3% between the Pseudomonas strains. This is the first study to use molecular methods to investigate the distribution of a gene encoding organophosphonate metabolism, and indicates that the phnA gene is ubiquitous within soils from geographically distinct regions. Such an observation supports the proposition that phosphonoacetate is a compound that may also have a biogenic origin.
Molecular modelling of the androgen receptor axis: rational basis for androgen receptor intervention in androgen‐independent prostate cancer
Authors: FLETTERICK ROBERT J.
Published: December 2005

Androgen depletion in combination with antiandrogenic agents is initially highly effective for treating prostate cancer, and is the recommended treatment for more advanced or higher‐grade tumours. However, many tumours eventually become insensitive to androgens, even though the androgen receptor (AR) continues to be expressed. Computational chemistry combined with structural analysis of nuclear receptors and determination of binding affinities of natural and designed coregulators (coactivators and corepressors) provides the theoretical framework for the rational design of novel therapeutic agents directed at the AR. Adding alternative groups to various sites throughout the receptor can alter the conformation of the molecule and its functional binding with coactivators or corepressors. Possible molecules can be identified thoroughly and systematically using intelligent high‐throughput screening and FASTrack chemistry (three‐dimensional crystallography). Applying these techniques should eventually result in therapeutic agents for androgen‐independent prostate cancer that can block binding of AR coactivators while simultaneously increasing binding of AR corepressors.
Targeted discovery tools: proteomics and chromatin immunoprecipitation‐on‐chip
Authors: LE GUEZENNEC XAVIER , BRINKMAN ARIE B. , VERMEULEN MICHIEL , DENISSOV SERGEÏ G. , GAZZIOLA CINZIA , LOHRUM MARION E. , STUNNENBERG HENK G.
Published: December 2005

Despite the availability of several completely sequenced genomes, we are still, for the most part, ignorant about how genes interact and regulate each other within a given cell type to specify identity, function and cellular memory. A realistic model of cellular regulation based on current knowledge indicates that many interacting networks operate at the epigenetic, transcriptional, translational and post‐translational levels, with feedback between the various levels. Protein–protein and protein–DNA interactions help to define which genes may be activated in a particular cell, and determine whether external cues cause activation or repression. New technologies, e.g. proteomics using mass spectrometry, high‐density DNA or oligonucleotide microarrays (chips), and chromatin immunoprecipitation (ChIP), provide new and exciting tools for deciphering the pathways and proteins controlling gene expression. Analysis of these pathways offers new insight that aids targeted drug development.
Validation of molecular targets in prostate cancer
Authors: SCHALKEN JACK A.
Published: December 2005

As prostate cancer is not a single disease, it is important to identify the pivotal pathway in the patient being treated. The molecular environment is the site of current oncological research to define new therapeutic targets for hormone‐refractory disease, offering the potential to eventually individualize treatment through stratification of pathways. Targets may be validated either phenotypically (e.g. androgen receptor, cadherin) or functionally (e.g. prostate cancer‐specific genes). In addition, several other candidates are potentially suitable, while others await discovery. Important initial steps have been made in the search for prostate cancer stem cells; identifying stem cells and the stromal, hormonal, and other signalling molecules that influence their behaviour would have important implications for managing prostate cancer. Although individual therapeutic pathways might be ineffective in a particular molecular environment, combinations of approaches might be capable of producing synergistic effects. A multimodal approach thus might be the best solution. Determining where best to search for a molecular target, and validating whether the target is associated with a sufficiently aggressive malignant process to justify further study is difficult, but the potential benefits are enormous.
Targeting apoptosis in prostate cancer: focus on caspases and inhibitors of apoptosis proteins
Authors: WATSON R. WILLIAM G. , FITZPATRICK JOHN M.
Published: December 2005

Androgens are critical to the growth and differentiation of prostate epithelial cells. Removal of androgen normally results in apoptosis, but androgen‐independent tumours have developed mechanisms that allow cells to survive the loss of androgen. The caspases are central mediators of cell death. An important area for research involves manipulating caspases by novel mechanisms to induce apoptosis. However, such mechanisms as diethylmaleate priming are limited by an inability to selectively target tumour cells. Inhibitors of apoptosis proteins (IAPs) are recently identified anti‐apoptotic caspase regulators. Each IAP homologue has a different mechanism of action. Because more than one member of the IAP family may be overexpressed in prostate cancer, successful treatment strategies will be defined by the ability to block all of the IAP expressed. Anti‐sense oligonucleotide strategies have been shown to decrease IAP expression and increase prostate cancer cell susceptibility to apoptotic induction, although not by mitochondrial‐mediated pathways. Fully understanding the basic apoptotic pathway and its regulation in prostate cancer will lead to more targets for manipulation, which can be translated into novel therapies. This article focuses on the role of the caspases and IAP in developing a rational approach to using apoptosis as a therapeutic target.
Design of clinical trials in advanced prostate cancer: avoiding the dead ends
Authors: DEBRUYNE FRANS M.J.
Published: December 2005

Despite more than 30 years of clinical trials, investigations in prostate cancer have not succeeded in making advances comparable to those in other branches of research, such as breast cancer. Indeed, prostate cancer trials have repeatedly run into a series of ‘dead ends’, as investigators face the problems of inadequate funding for research, treatments that result in only minimal improvements in survival, and lack of treatment options that have sufficient prospects for success. This article briefly reviews the strategies behind clinical investigations into prostate cancer over the last three decades, evaluates the pitfalls that have hindered research, and makes suggestions for the appropriate design of clinical trials that are safe and beneficial to patients while maintaining cost‐effectiveness and accountability to patients and society.
A shift from diffuse to focal cortical activity with development
Authors: Durston Sarah , Davidson Matthew C. , Tottenham Nim , Galvan Adriana , Spicer Julie , Fossella John A. , Casey B.J.
Published: December 2005

Recent imaging studies have suggested that developmental changes may parallel aspects of adult learning in cortical activation becoming less diffuse and more focal over time. However, while adult learning studies examine changes within subjects, developmental findings have been based on cross‐sectional samples and even comparisons across studies. Here, we used functional MRI in children to test directly for shifts in cortical activity during performance of a cognitive control task, in a combined longitudinal and cross‐sectional study. Our longitudinal findings, relative to our cross‐sectional ones, show attenuated activation in dorsolateral prefrontal cortical areas, paralleled by increased focal activation in ventral prefrontal regions related to task performance.
Preference for consonance over dissonance by hearing newborns of deaf parents and of hearing parents
Authors: Masataka Nobuo
Published: December 2005

Behavioral preferences for consonance over dissonance were tested in hearing infants of deaf parents and in hearing infants of hearing parents when they were 2 days old. Using a modified visual‐fixation‐based, auditory‐preference procedure, I found that both 2‐day‐old infants of deaf parents and those of hearing parents looked longer at a visual stimulus when looking produced the original version of a Mozart minuet as opposed to a version altered to contain many dissonant intervals. The relative magnitude of such preference did not significantly differ whether their parents were deaf or hearing. Infants prefer consonance over dissonance, and the preference is present from birth and is not dependent on any specific prenatal or early postnatal experience.
The development of landmark and beacon use in young children: evidence from a touchscreen search task
Authors: Sutton Jennifer E.
Published: December 2005

Children ages 2, 3 and 4 years participated in a novel hide‐and‐seek search task presented on a touchscreen monitor. On beacon trials, the target hiding place could be located using a beacon cue, but on landmark trials, searching required the use of a nearby landmark cue. In Experiment 1, 2‐year‐olds performed less accurately than older children on landmark trials but performed equivalently on beacon trials. In Experiment 2, the number of items on the screen was reduced and 2‐year‐olds’ performance improved. Use of the landmark transformation technique in Experiment 3 revealed that older children formed a more precise landmark–target spatial relationship than 2‐year‐olds. Experiment 4 showed that the transformation itself was not responsible for the youngest participants’ decreased accuracy in Experiment 3. Overall, beacons were utilized effectively by all participants, but the use of landmark cues is refined between the ages of 2 and 4.
‘About’ Puzzles, Muddles and First Person Inferences
Authors: Cave Peter
Published: December 2005

Often we have coarsely grained knowledge: for example, we know about how many people are present. In possessing such knowledge, we also have finer grained knowledge of what is not: there certainly is nothing like that number of people here. The combination of such knowledge types, through sorites, generates contradiction and bafflement. This paper seeks to resolve the bafflement: it rejects a Timothy Williamson proposal, introduces muddle numbers and inference gaps, and shows how the different grains of knowledge do not always meet. In so doing, the paper identifies a distinctive first‐person inferring.
Capital–Skill Complementarity and Inequality in Sweden
Authors: Lindquist Matthew J.
Published: December 2005

Income inequality increased in Sweden during the 1980s and 1990s, as did the returns to higher education. The main conclusion of this study is that increased income inequality between high‐ and low‐skilled workers is demand driven and is due to the presence of capital–skill complementarity in production. Increased investments in new, more efficient capital equipment, along with a slowdown in the growth rate of skilled labor, have raised the ratio of effective capital inputs per skilled worker, which, in turn, has increased the relative demand (and market return) for skilled labor through the capital–skill complementarity mechanism.
Welfare Implications of Non‐scale R&D‐based Growth Models
Authors: Steger Thomas M.
Published: December 2005

Non‐scale R&D‐based growth models imply that the decentral and the socially optimal long‐run growth rate coincide. Nonetheless, the distortions inherent in a market economy bias both the R&D investment share and the saving rate. As a result, the level of the balanced growth path may differ substantially between the two types of solution, implying a dramatic loss in welfare. The present paper explores the sources and magnitude of this gap. In addition, the consequences of public policies are examined, distinguishing between isolated policy measures from an overall policy programme.