bluuebunny/crossref_metadata_2025 huggingface dataset:
Prenatal Diagnosis of Minute Supernumerary Marker Chromosomes
Authors: Cotter Philip D. , Drexler Kathryn , Corley Amy L. , Covert Susan M. , Moland Jessica S. , Govberg Inna J. , Norton Mary E.
Published: February 2005

The identification of supernumerary marker chromosomes (SMC) at prenatal diagnosis is problematic, particularly for the prediction of phenotype. The assessment of phenotypic risk is based on the size, morphology and origin of the SMC. Fluorescence in situ hybridization (FISH) characterization and family studies are also employed to aid in determining the significance of a prenatally ascertained SMC. Generally, SMC containing euchromatin are more likely to be associated with abnormal phenotypes and SMC without euchromatin are more likely to result in normal phenotypes. The smallest of SMC, minute SMC (minSMC) appear as dot-like or centric fragments and are particularly difficult to identify and characterize. Previous empirical observations suggested that the risk of phenotypic abnormality in prenatally ascertained minSMC was ≤5%. We identified minSMC in chorionic villus samples (CVS) or amniocytes from 11 unrelated pregnancies. The chromosomal origin of each minSMC was identified by sequential FISH analysis with chromosome-specific centromere probes. Further FISH analysis with whole chromosome paint probes was undertaken to assess each minSMC for the presence or absence of euchromatin, since the presence of euchromatin may be associated with a higher risk of abnormality. Two minSMC were shown to have euchromatin. The first, a minSMC(12) was found in CVS but not confirmed in amniocytes, indicating confined placental mosaicism. The second, a minSMC derived from chromosome 19, was associated with ultrasound abnormalities. Apart from a case with mild speech delay, the remaining minSMC cases without detectable euchromatin had a normal outcome at birth and/or on longer term follow-up. Additional FISH analyses with a telomeric repeat probe showed no signal on any of the minSMC tested, suggesting that they were ring chromosomes in structure. These data further support the concept that minSMC containing euchromatin are more likely to be associated with an abnormal phenotype, although as more data are collected, this may vary by chromosome of origin. The absence of detectable euchromatin, while not guaranteeing a normal result, is most likely to have a normal outcome. The present report and previous studies do not yet allow any significant adjustment of the empirical ≤5% risk estimate for minSMC identified at prenatal diagnosis. However, reporting of additional cases with characterization of the minSMC and particularly with long-term follow-up will, in time, allow for more accurate risk estimates and provide prognostic information.
First Trimester Screening
Authors: Ellestad Sarah C. , Wells Steven R. , Kuller Jeffrey A.
Published: February 2005

Screening for aneuploidy has traditionally been reserved for women of advanced maternal age. More recent advances in serum screening and ultrasound technology have allowed women of all ages to be offered screening in the second and even first trimester. These methods and their effectiveness are discussed.
Gonadotropin Stimulation May Not Affect the Expression of Heparin-Binding Epidermal Growth Factor-Like Growth Factor in the Murine Endometrium
Authors: Ku Seung-Yup , Jee Byung Chul , Suh Chang Suk , Kim Seok Hyun , Choi Young Min , Kim Jung Gu , Moon Shin Yong
Published: February 2005

Background: Present human data reveal that gonadotropin stimulation for in vitro fertilization and embryo transfer (IVF-ET) is detrimental to uterine receptivity. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is important in the early stage of mouse embryonic implantation since it is expressed in the murine endometrium before the attachment reaction. Gonadotropin receptors have been found on the murine endometrium. In this study, we assessed the expression of HB-EGF mRNA on the gonadotropin-stimulated murine endometrium and sought evidence of whether the gonadotropin-induced, altered uterine receptivity is associated with a change in the HB-EGF expression. Methods: Quantitative, competitive reverse-transcription polymerase chain reaction (PCR) and immunohistochemistry were performed to evaluate the expression of HB-EGF mRNA on the stimulated murine endometrium from pregnant uteri of gestation day (g.d.) 5.0 after injection of saline, or pregnant mare serum gonadotropin (PMSG) 5 or 10 IU. Results: The expression of HB-EGF mRNA showed no significant increase or decrease in the endometrial expression in PMSG groups, compared to the control group (natural coitus with saline injection), on g.d. 5.0. This finding was consistent with the immunostaining of HB-EGF protein, and there was no significant difference in the staining intensity among the 3 groups. Conclusion: This study reveals that ovarian stimulation by gonadotropin may not influence the expression of HB-EGF in the murine endometrium. Further investigations are necessary to elucidate whether embryonic HB-EGF receptor status relative to endometrial HB-EGF expression is affected by ovarian stimulation.
Tubular CD146 Expression in Nephropathies Is Related to Chronic Renal Failure
Authors: Daniel Laurent , Bardin Nathalie , Moal Valérie , Dignat-George Françoise , Berland Yvon , Figarella-Branger Dominique
Published: February 2005

Background: CD146, a member of the immunoglobulin superfamily, is mainly expressed at the endothelial junction. The soluble form of CD146 is increased in the serum of patients with chronic renal failure. The aim of the study was to investigate CD146 expression on biopsies of normal kidney and nephropathies. Methods: We did an immunohistochemical analysis of 10 normal renal tissues and 126 patients with nephropathies. Results: The mean age of the patients was 47.5 ± 18 years with 65% of men. At the time of the biopsy, 73 patients (57.9%) had a renal failure and the mean proteinuria was 3.3 ± 2.9 g/24 h. Inflammatory syndrome was present in 60 (47.6%) patients. Fibrous interstitial changes from minimal lesions to diffuse lesions were seen in 105 (83.3%) biopsies; the mean glomerulosclerosis index was 16.9 ± 19.7%. Normal kidneys showed CD146 staining on endothelial cells, smooth muscle cells, and mesangium. Normal tubular cells were not stained. If endocapillary proliferation was present, the mesangial CD146 expression was higher. This mesangial expression correlated with proteinuria (p = 0.007) and not with renal failure (p = 0.07). A de novo expression on tubular cells was found in 53 patients (42%) and this expression correlated with age (p < 0.001), male sex (p = 0.04), glomerulosclerosis (p < 0.001), interstitial fibrosis (p < 0.001), and renal failure (p < 0.001). Conclusion: Renal CD146 expression is of interest for determining the pathogenesis of mesangial alterations during glomerular injuries and of tubular phenotypic changes during chronic renal failure.
Granulocytic Sarcoma of the Female Genital Tract: Report of a Case with an Unusual Presentation
Authors: Tripathi Reva , Sharma Babita , Chaturvedi K. Uma , Khurana Neeta , Mala Y.M.
Published: February 2005

Granulocytic sarcoma of the female genital tract is a rare occurrence. A case of a perimenopausal female is presented who reported with a history of menorrhagia with a lump in the abdomen. A diagnosis of fibroid uterus was made but laparotomy findings were suggestive of inoperable ovarian malignancy with metastases. Postoperatively the patient suddenly became very anemic. Hematological investigations and histopathological reports from ovaries, myometrium, endometrium and intraperitoneal deposits all revealed acute myeloid leukemia. The patient received two cycles of chemotherapy but later succumbed to her disease. Extrauterine causes of menorrhagia should be considered before instituting definitive treatment. Preoperative induction chemotherapy may be more successful in cases of granulocytic sarcoma who tend to have a poor prognosis.
Adipocyte Fatty Acid–Binding Protein Expression and Lipid Accumulation Are Increased During Activation of Murine Macrophages by Toll-Like Receptor Agonists
Authors: Kazemi Mahmood R. , McDonald Carol M. , Shigenaga Judy K. , Grunfeld Carl , Feingold Kenneth R.
Published: February 2005

Objective—

Toll-like receptors (TLRs) recognize pathogens and mediate signaling pathways important for host defense. Recent studies implicate TLR polymorphisms in atherosclerosis risk in humans. Adipocyte fatty acid–binding protein (aP2) is present in macrophages and has an important role in atherosclerotic plaque development. We investigated aP2 expression in RAW 264.7 cells treated with lipopolysaccharide (LPS) and other TLR agonists and assessed lipid accumulation in these activated murine macrophages.

Methods and Results—

Stimulation with LPS, a TLR4 ligand, resulted in a 56-fold increase in aP2 mRNA expression, and zymosan, a TLR2 ligand, induced an ≈1500-fold increase. Polyinosine: polycytidylic acid (poly I:C), a TLR3 ligand, led to a 9-fold increase. Levels of aP2 protein were significantly increased in LPS or zymosan-treated macrophages compared with control or poly I:C–treated cells. In addition, the cholesteryl ester content of LPS or zymosan-treated macrophages was ≈5-fold greater in the presence of low-density lipoprotein, and triglyceride content was ≈2-fold greater in the absence of exogenous lipid than control or poly I:C–treated cells.

Conclusions—

Expression of macrophage aP2 is induced on TLR activation and parallels increases in cholesteryl ester and triglyceride levels. These results provide a molecular link between the known roles of TLR and aP2 in foam cell formation.
Overexpression of Hyaluronan in the Tunica Media Promotes the Development of Atherosclerosis
Authors: Chai Song , Chai Qing , Danielsen Carl C. , Hjorth Peter , Nyengaard Jene R. , Ledet Thomas , Yamaguchi Yu , Rasmussen Lars M. , Wogensen Lise
Published: February 2005

The arterial content of hyaluronan (HA) undergoes diffuse changes as part of the diabetic macroangiopathy. Because HA influences the phenotype of vascular cells in vitro such as proliferation, migration, and secretion, it is tempting to speculate that diabetes-induced hastened cardiovascular disease may be linked to the increased amount of HA. To explore the pathophysiological role of altered HA content in the arterial wall in vivo, we created transgenic (Tg) mice with HA overexpression in smooth muscle cells (SMCs) in large and small vessels, targeted by the α smooth-muscle-cell-actin (αSMA) promoter fused to the human hyaluronan synthase 2 (hHAS2) cDNA. RT-PCR demonstrated hHAS2 mRNA expression in the tunica media of large and small vessels. In situ hybridization confirmed that hHAS2 mRNA was targeted to the SMCs. The aortic HA content was elevated in the Tg mice, and by immunohistochemistry, it was seen that HA accumulated in the tunica media. The secretory profile of high- and low-molecular HA was similar in wild-type and Tg animals. Overproduction of HA in the aorta resulted in thinning of the elastic lamellae in Tg mice. Our data suggest that this may lead to increased mechanical stiffness and strength, as determined by controlled stretching until failure. Finally, overproduction of HA on the genetic background of the ApoE-deficient mouse strain promoted atherosclerosis development in the aorta. These results indicate that a single component of the diabetic macroangiopathy, diffuse accumulation of HA, accelerates the progression of atherosclerosis.
Molecular Basis of Estrogen-Induced Cyclooxygenase Type 1 Upregulation in Endothelial Cells
Authors: Gibson Linda L. , Hahner Lisa , Osborne-Lawrence Sherri , German Zohre , Wu Kenneth K. , Chambliss Ken L. , Shaul Philip W.
Published: February 2005

Estrogen upregulates cyclooxygenase-1 (COX-1) expression in endothelial cells. To determine the basis of this process, studies were performed in ovine endothelial cells transfected with the human COX-1 promoter fused to luciferase. Estradiol (E
2
) caused activation of the COX-1 promoter with maximal stimulation at 10
−8
mol/L E
2
, and the response was mediated by either ERα or ERβ. Mutagenesis revealed a primary role for a putative Sp1 binding motif at −89 (relative to the ATG codon) and lesser involvement of a consensus Sp1 site at −111. Electrophoretic mobility shift assays yielded a single complex with the site at −89, and supershift analyses implicated AP-2α and ERα, and not Sp1, in protein-DNA complex formation. In endothelial cells with minimal endogenous ER, the transfection of ERα mutants lacking the DNA binding domain or primary nuclear localization signals caused 4-fold greater stimulation of promoter activity with E
2
than wild-type ERα. In contrast, mutant ERα lacking the A-B domains was inactive. Thus, estrogen-mediated upregulation of COX-1 in endothelium is uniquely independent of direct ERα-DNA binding and instead entails protein-DNA interaction involving AP-2α and ERα at a proximal regulatory element. In addition, the process may be initiated by cytoplasmic ERα, and critical receptor elements reside within the amino terminus.
Cyclic Strain Inhibits Notch Receptor Signaling in Vascular Smooth Muscle Cells In Vitro
Authors: Morrow David , Sweeney Catherine , Birney Yvonne A. , Cummins Philip M. , Walls Dermot , Redmond Eileen M. , Cahill Paul A.
Published: February 2005

Notch signaling has been shown recently to regulate vascular cell fate in adult cells. By applying a uniform equibiaxial cyclic strain to vascular smooth muscle cells (SMCs), we investigated the role of strain in modulating Notch-mediated growth of SMCs in vitro. Rat SMCs cultured under conditions of defined equibiaxial cyclic strain (0% to 15% stretch; 60 cycles/min; 0 to 24 hours) exhibited a significant temporal and force-dependent reduction in Notch 3 receptor expression, concomitant with a significant reduction in Epstein Barr virus latency C promoter-binding factor-1/recombination signal-binding protein of the Jκ immunoglobulin gene–dependent Notch target gene promoter activity and mRNA levels when compared with unstrained controls. The decrease in Notch signaling was Gi-protein– and mitogen-activated protein kinase–dependent. In parallel cultures, cyclic strain inhibited SMC proliferation (cell number and proliferating cell nuclear antigen expression) while significantly promoting SMC apoptosis (annexin V binding, caspase-3 activity and
bax/bcl-x

L

ratio). Notch 3 receptor overexpression significantly reversed the strain-induced changes in SMC proliferation and apoptosis to levels comparable to unstrained control cells, whereas Notch inhibition further potentiated the changes in SMC apoptosis and proliferation. These findings suggest that cyclic strain inhibits SMC growth while enhancing SMC apoptosis, in part, through regulation of Notch receptor and downstream target gene expression.
Blood Oxygen Level–Dependent MRI of Cerebral CO
2
Reactivity in Severe Carotid Stenosis and Occlusion
Authors: Ziyeh Sargon , Rick Jochen , Reinhard Matthias , Hetzel Andreas , Mader Irina , Speck Oliver
Published: February 2005

Background and Purpose—

Impaired cerebrovascular reserve capacity (CVC) is a risk factor for ischemic events in patients with high-grade carotid stenosis and occlusion. In this study, the CVC in response to a CO
2
challenge was evaluated with blood oxygen level–dependent (BOLD) MRI and the results compared with those of a transcranial Doppler CO
2
tests.

Methods—

A T
2
*-weighted single-shot multigradient echo-planar imaging sequence was used to determine cerebral CO
2
reactivity. T
2
* values were calculated for each pixel at rest and during a challenge with 7% CO
2
, and a reference function was fitted to the T
2
* time courses. Whole-brain color-coded ΔT
2
* parameter maps were calculated and visually evaluated for regional differences. Additionally, a region-of-interest analysis was undertaken. Average values for ΔT
2
* normalized to changes in end-tidal P
co
2
were calculated. Results were correlated with a transcranial Doppler CO
2
tests in 20 patients with high-grade stenosis or occlusion of the carotid artery.

Results—

Color parameter maps showed areas of decreased BOLD effect within the internal carotid artery territory in 12 of 13 hemispheres with impaired CVC in transcranial Doppler CO
2
test. Regional normalized ΔT
2
* was highly correlated with changes of middle cerebral artery blood flow velocity in transcranial Doppler CO
2
test. Normalized ΔT
2
* was significantly reduced in hemispheres with impaired CVC in transcranial Doppler (
P
<0.0001).

Conclusions—

BOLD MRI can easily be included in routine MRI exams. The technique is robust and yields diagnostic information concerning the cerebrovascular reserve.
Recovery From Aphasia After Hemicraniectomy for Infarction of the Speech-Dominant Hemisphere
Authors: Kastrau Frank , Wolter Marcus , Huber Walter , Block Frank
Published: February 2005

Background and Purpose—

The space-occupying effect of cerebral edema limits survival chances of patients with severe ischemic stroke. Besides conventional therapies to reduce intracranial pressure, hemicraniectomy can be considered as a therapeutic option after space-occupying cerebral infarction. There is controversy regarding the use of this method in patients with infarction of the speech-dominant hemisphere.

Methods—

In 14 patients with infarction of the dominant hemisphere and subsequent treatment with hemicraniectomy, recovery from aphasic symptoms was evaluated retrospectively. A group of patients who were treated between 1994 and 2003 in our aphasia ward was selected for the study. In all patients, a psychometric quantification was accomplished applying the Aachen Aphasia Test at least twice within a mean observation period of 470 days.

Results—

A significant improvement of the statistical parameters representing different aspects of aphasia was observed in 13 of 14 patients. Also, an increase of the ability to communicate was evident in 13 patients. Young age at the time of stroke and early poststroke decompressive surgery were identified as main predictors for recovery from aphasia.

Conclusions—

A significant improvement of aphasic symptoms can be observed in a preselected group of patients after a massive stroke of the speech-dominant hemisphere treated by consecutive hemicraniectomy. Therefore, decompressive surgery can be considered for the treatment of this kind of stroke.
Leadership: Time for a New Direction?
Authors: Alimo-Metcalfe Beverly , Alban-Metcalfe John
Published: February 2005

After reviewing the literature on leadership that culminated in what has been described as the ‘New Paradigm’, this article discusses the research which has led to the development of what might be regarded as a ‘New New Paradigm’ model. The research was based on a gender-inclusive and black and minority ethnic-inclusive sample of over 3,500 managers and professionals, at different levels (chief executives, top, senior and middle managers), working in the UK National Health Service and local government. The model that emerged, which led to the development of a diagnostic 360-degree feedback instrument, the Transformational Leadership Questionnaire, has been found to be sufficiently robust as to generalize to private sector and other public sector organizations. Apart from having been inclusive at all stages of its development, the model is new in that it is based on a ‘nearby’ rather than ‘distant’ or ‘heroic’ approach to leadership, using a Grounded Theory methodology. It leads to an understanding of leadership that goes beyond transformational models and, recognizing the significance of Greenleaf’s concept of ‘servant leadership’, focuses on the development of the individual, in an organizational context.
Role of selectins in the triggering, growth, and dissemination of T-lymphoma cells: implication of L-selectin in the growth of thymic lymphoma
Authors: Bélanger Simon D. , St-Pierre Yves
Published: February 2005

We previously showed that intercellular adhesion molecule-1 (ICAM-1) expression by the host is essential for lymphoma dissemination. Because selectins usually act in a coordinated fashion with ICAM-1 in the recruitment of circulating normal cells, we investigated their implication in lymphomagenesis and metastasis. Using selectin-deficient mice, we found that though the absence of E-, P-, or L-selectins did not affect the triggering of radiation-induced thymic lymphoma, the absence of L-selectin on lymphoma cells reduced their capacity to grow in the thymus. This defect, however, was overcome by altering the integrity of the L-selectin-mediated interactions in the thymus, as shown in L-selectin-deficient mice and by adoptive transfer experiments. We also found that lack of selectin expression by the host significantly delayed the dissemination of lymphomas to peripheral tissues. This resistance of selectin-deficient mice to lymphoma metastasis was dependent on the intrinsic properties of lymphoma cells because highly tumorigenic variants were insensitive to the absence of selectins. Observations that lymphoma cells disseminate with the same efficiency in normal and selectin-deficient mice suggest that selectins exert their influence at the posthoming stage of metastasis, as does ICAM-1. These results provide definitive evidence that selectins play a significant role at different steps of T-cell lymphoma development. (Blood. 2005;105:4800-4806)
The relative role of PLCβ and PI3Kγ in platelet activation
Authors: Lian Lurong , Wang Yanfeng , Draznin Julia , Eslin Don , Bennett Joel S. , Poncz Mortimer , Wu Dianqing , Abrams Charles S.
Published: February 2005

Stimulation of platelet G protein–coupled receptors results in the cleavage of phosphatidylinositol 4,5-trisphosphate (PIP2) into inositol 1,4,5-trisphosphate and 1,2-diacylglycerol by phospholipase C (PLCβ). It also results in the phosphorylation of PIP2 by the γ isoform of phosphatidylinositol 3-kinase (PI3Kγ) to synthesize phosphatidylinositol 3,4,5-trisphosphate. To understand the role of PIP2 in platelet signaling, we evaluated knock-out mice lacking 2 isoforms of PLCβ (PLCβ2 and PLCβ3) or lacking the Gβγ-activated isoform of PI3K (PI3Kγ). Both knock-out mice were unable to form stable thrombi in a carotid injury model. To provide a functional explanation, knock-out platelets were studied ex vivo. PLCβ2/β3–/– platelets failed to assemble filamentous actin, had defects in both secretion and mobilization of intracellular calcium, and were unable to form stable aggregates following low doses of agonists. Platelets lacking PI3Kγ disaggregated following low-dose adenosine diphosphate (ADP) and had a mildly impaired ability to mobilize intracellular calcium. Yet, they exhibited essentially normal actin assembly and secretion. Remarkably, both PLCβ2/β3–/– and PI3Kγ–/– platelets spread more slowly upon fibrinogen. These results suggest substantial redundancy in platelet signaling pathways. Nonetheless, the diminished ability of knock-out platelets to normally spread after adhesion and to form stable thrombi in vivo suggests that both PLCβ2/β3 and PI3Kγ play vital roles in platelet cytoskeletal dynamics.
Thrombopoietin enhances expression of vascular endothelial growth factor (VEGF) in primitive hematopoietic cells through induction of HIF-1α
Authors: Kirito Keita , Fox Norma , Komatsu Norio , Kaushansky Kenneth
Published: February 2005

Thrombopoietin (TPO), the primary regulator of thrombopoiesis, is also an important, nonredundant mediator of hematopoietic stem cell (HSC) development. For example, following transplantation, HSC expansion is approximately 15-fold more robust in normal than in Tpo-/- mice. Vascular endothelial growth factor (VEGF) also plays an important role in HSC development, where it acts in an intracellular autocrine fashion to promote cell survival. Thus, we tested the hypothesis that TPO affects the autocrine production of VEGF to account for its favorable effects on HSCs. We found that VEGF transcripts are reduced in purified sca-1+/c-kit+/Gr-1- marrow cells derived from Tpo-/- mice and that TPO induces VEGF transcripts in these primitive hematopoietic cells. Additional studies determined that TPO induces VEGF expression by increasing the level of its primary transcription factor, hypoxia-inducible factor 1α (HIF-1α), by enhancing its protein stability. Moreover, VEGF expression is important for the TPO effect on primitive hematopoietic cells because blockade of the VEGF receptor with a specific inhibitor substantially blunts TPO-induced growth of single sca-1+/c-kit+/Gr-1- marrow cells in serum-free cultures. Along with previous findings that TPO affects Hox transcription factors that regulate HSC proliferation, these data contribute to our growing understanding of the mechanisms by which a hormone can influence stem cell development.
Endothelial apoptosis induced by inhibition of integrins αvβ3 and αvβ5 involves ceramide metabolic pathways
Authors: Erdreich-Epstein Anat , Tran Linda B. , Cox Órla T. , Huang Elaine Y. , Laug Walter E. , Shimada Hiroyuki , Millard Melissa
Published: February 2005

Matrix ligation of integrins αvβ3/αvβ5 is critical for endothelial survival and angiogenesis. We have previously shown that ceramide, a proapoptotic lipid second messenger, increases during endothelial anoikis (detachment-induced apoptosis). We now show that RGDfV, an integrin αvβ3/αvβ5 cyclic function-blocking peptide, increased ceramide and decreased sphingomyelin in human brain microvascular endothelial cells (HBMECs) plated on vitronectin, suggesting that sphingomyelin hydrolysis contributes to RGDfV-induced ceramide increase. Desipramine and imipramine, inhibitors of acid sphingomyelinase (ASMase), suppressed RGDfV-induced ceramide increase. Importantly, desipramine, imipramine, and a third ASMase inhibitor, SR33557, but not inhibitors of neutral sphingomyelinase, suppressed RGDfV-induced apoptosis, suggesting that ASMase was required for integrin-mediated apoptosis. Myriocin, an inhibitor of de novo ceramide synthesis, had no effect on RGDfV-induced HBMEC apoptosis. Interestingly, ASMase inhibitors also suppressed the RGDfV-induced loss of spreading on vitronectin. RGDfV induced a similar increase in ceramide and apoptosis in HBMECs on poly-l-lysine or vitronectin, although cells detached only from vitronectin, indicating that cell detachment was not required for RGDfV-induced apoptosis. Our results suggest involvement of ASMase and ceramide in endothelial apoptosis induced by inhibition of integrins αvβ3/αvβ5, and propose a novel molecular mechanism for the antiangiogenic effect of RGDfV.
Pim and Akt oncogenes are independent regulators of hematopoietic cell growth and survival
Authors: Hammerman Peter S. , Fox Casey J. , Birnbaum Morris J. , Thompson Craig B.
Published: February 2005

The Akt kinases promote hematopoietic cell growth and accumulation through phosphorylation of apoptotic effectors and stimulation of mTOR-dependent translation. In Akt-transformed leukemic cells, tumor growth can be inhibited by the mTOR inhibitor rapamycin, and clinical trials of rapamycin analogs for the treatment of leukemia are under way. Surprisingly, nontransformed hematopoietic cells can grow and proliferate in the presence of rapamycin. Here, we show that Pim-2 is required to confer rapamycin resistance. Primary hematopoietic cells from Pim-2– and Pim-1/Pim-2–deficient animals failed to accumulate and underwent apoptosis in the presence of rapamycin. Although animals deficient in Akt-1 or Pim-1/Pim-2 are viable, few animals with a compound deletion survived development, and those that were born had severe anemia. Primary hematopoietic cells from Akt-1/Pim-1/Pim-2–deficient animals displayed marked impairments in cell growth and survival. Conversely, ectopic expression of either Pim-2 or Akt-1 induced increased cell size and apoptotic resistance. However, though the effects of ectopic Akt-1 were reversed by rapamycin or a nonphosphorylatable form of 4EBP-1, those of Pim-2 were not. Coexpression of the transgenes in mice led to additive increases in cell size and survival and predisposed animals to rapid tumor formation. Together, these data indicate that Pim-2 and Akt-1 are critical components of overlapping but independent pathways, either of which is sufficient to promote the growth and survival of nontransformed hematopoietic cells.
Marked alveolar apoptosis/proliferation imbalance in end-stage emphysema
Authors: Calabrese Fiorella , Giacometti Cinzia , Beghe Bianca , Rea Federico , Loy Monica , Zuin Renzo , Marulli Giuseppe , Baraldo Simonetta , Saetta Marina , Valente Marialuisa
Published: February 2005

Background

Apoptosis has recently been proposed to contribute to the pathogenesis of emphysema.

Methods

In order to establish if cell fate plays a role even in end-stage disease we studied 16 lungs (9 smoking-associated and 7 α1antitrypsin (AAT)-deficiency emphysema) from patients who had undergone lung transplantations. Six unused donor lungs served as controls. Apoptosis was evaluated by TUNEL analysis, single-stranded DNA laddering, electron microscopy and cell proliferation by an immunohistochemical method (MIB1). The role of the transforming growth factor (TGF)-β1 pathway was also investigated and correlated with epithelial cell turnover and with the severity of inflammatory cell infiltrate.

Results

The apoptotic index (AI) was significantly higher in emphysematous lungs compared to the control group (p ≤ 0.01), particularly if only lungs with AAT-deficiency emphysema were considered (p ≤ 0.01 vs p = 0.09). The proliferation index was similar in patients and controls (1.9 ± 2.2 vs 1.7 ± 1.1). An increased number of T lymphocytes was observed in AAT-deficiency lungs than smoking-related cases (p ≤ 0.05). TGF-β1 expression in the alveolar wall was higher in patients with smoking-associated emphysema than in cases with AAT-deficiency emphysema (p ≤ 0.05). A positive correlation between TGF-βRII and AI was observed only in the control group (p ≤ 0.005, r2 = 0.8). A negative correlation was found between the TGF-β pathway (particularly TGF-βRII) and T lymphocytes infiltrate in smoking-related cases (p ≤ 0.05, r2 = 0.99)

Conclusion

Our findings suggest that apoptosis of alveolar epithelial cells plays an important role even in end-stage emphysema particularly in AAT-deficiency disease. The TGFβ-1 pathway does not seem to directly influence epithelial turnover in end-stage disease. Inflammatory cytokine different from TGF-β1 may differently orchestrate cell fate in AAT and smoking-related emphysema types.
Quantification of the magnification and distortion effects of a pediatric flexible video-bronchoscope
Authors: Masters IB , Eastburn MM , Francis PW , Wootton R , Zimmerman PV , Ware RS , Chang AB
Published: February 2005

Background

Flexible video bronchoscopes, in particular the Olympus BF Type 3C160, are commonly used in pediatric respiratory medicine. There is no data on the magnification and distortion effects of these bronchoscopes yet important clinical decisions are made from the images. The aim of this study was to systematically describe the magnification and distortion of flexible bronchoscope images taken at various distances from the object.

Methods

Using images of known objects and processing these by digital video and computer programs both magnification and distortion scales were derived.

Results

Magnification changes as a linear function between 100 mm (×1) and 10 mm (×9.55) and then as an exponential function between 10 mm and 3 mm (×40) from the object. Magnification depends on the axis of orientation of the object to the optic axis or geometrical axis of the bronchoscope. Magnification also varies across the field of view with the central magnification being 39% greater than at the periphery of the field of view at 15 mm from the object. However, in the paediatric situation the diameter of the orifices is usually less than 10 mm and thus this limits the exposure to these peripheral limits of magnification reduction. Intraclass correlations for measurements and repeatability studies between instruments are very high, r = 0.96. Distortion occurs as both barrel and geometric types but both types are heterogeneous across the field of view. Distortion of geometric type ranges up to 30% at 3 mm from the object but may be as low as 5% depending on the position of the object in relation to the optic axis.

Conclusion

We conclude that the optimal working distance range is between 40 and 10 mm from the object. However the clinician should be cognisant of both variations in magnification and distortion in clinical judgements.
Integrating alternative splicing detection into gene prediction
Authors: Foissac Sylvain , Schiex Thomas
Published: February 2005

Background

Alternative splicing (AS) is now considered as a major actor in transcriptome/proteome diversity and it cannot be neglected in the annotation process of a new genome. Despite considerable progresses in term of accuracy in computational gene prediction, the ability to reliably predict AS variants when there is local experimental evidence of it remains an open challenge for gene finders.

Results

We have used a new integrative approach that allows to incorporate AS detection into ab initio gene prediction. This method relies on the analysis of genomically aligned transcript sequences (ESTs and/or cDNAs), and has been implemented in the dynamic programming algorithm of the graph-based gene finder EuGÈNE. Given a genomic sequence and a set of aligned transcripts, this new version identifies the set of transcripts carrying evidence of alternative splicing events, and provides, in addition to the classical optimal gene prediction, alternative optimal predictions (among those which are consistent with the AS events detected). This allows for multiple annotations of a single gene in a way such that each predicted variant is supported by a transcript evidence (but not necessarily with a full-length coverage).

Conclusions

This automatic combination of experimental data analysis and ab initio gene finding offers an ideal integration of alternatively spliced gene prediction inside a single annotation pipeline.
Comparison of seven methods for producing Affymetrix expression scores based on False Discovery Rates in disease profiling data
Authors: Shedden Kerby , Chen Wei , Kuick Rork , Ghosh Debashis , Macdonald James , Cho Kathleen R , Giordano Thomas J , Gruber Stephen B , Fearon Eric R , Taylor Jeremy MG , Hanash Samir
Published: February 2005

Background

A critical step in processing oligonucleotide microarray data is combining the information in multiple probes to produce a single number that best captures the expression level of a RNA transcript. Several systematic studies comparing multiple methods for array processing have used tightly controlled calibration data sets as the basis for comparison. Here we compare performances for seven processing methods using two data sets originally collected for disease profiling studies. An emphasis is placed on understanding sensitivity for detecting differentially expressed genes in terms of two key statistical determinants: test statistic variability for non-differentially expressed genes, and test statistic size for truly differentially expressed genes.

Results

In the two data sets considered here, up to seven-fold variation across the processing methods was found in the number of genes detected at a given false discovery rate (FDR). The best performing methods called up to 90% of the same genes differentially expressed, had less variable test statistics under randomization, and had a greater number of large test statistics in the experimental data. Poor performance of one method was directly tied to a tendency to produce highly variable test statistic values under randomization. Based on an overall measure of performance, two of the seven methods (Dchip and a trimmed mean approach) are superior in the two data sets considered here. Two other methods (MAS5 and GCRMA-EB) are inferior, while results for the other three methods are mixed.

Conclusions

Choice of processing method has a major impact on differential expression analysis of microarray data. Previously reported performance analyses using tightly controlled calibration data sets are not highly consistent with results reported here using data from human tissue samples. Performance of array processing methods in disease profiling and other realistic biological studies should be given greater consideration when comparing Affymetrix processing methods.
Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years
Authors: Junghans Barbara M , Crewther Sheila G
Published: February 2005

Background

Recently reported prevalences of myopia in primary school children vary greatly in different regions of the world. This study aimed to estimate the prevalence of refractive errors in an unselected urban population of young primary school children in eastern Sydney, Australia, between 1998 and 2004, for comparison with our previously published data gathered using the same protocols and other Australian studies over the last 30 years.

Methods

Right eye refractive data from non-cycloplegic retinoscopy was analysed for 1,936 children aged 4 to 12 years who underwent a full eye examination whilst on a vision science excursion to the Vision Education Centre Clinic at the University of New South Wales. Myopia was defined as spherical equivalents equal to or less than -0.50 D, and hyperopia as spherical equivalents greater than +0.50 D.

Results

The mean spherical equivalent decreased significantly (p < 0.0001) with age from +0.73 ± 0.1D (SE) at age 4 to +0.21 ± 0.11D at age 12 years. The proportion of children across all ages with myopia of -0.50D or more was 8.4%, ranging from 2.3% of 4 year olds to 14.7% of 12 year olds. Hyperopia greater than +0.50D was present in 38.4%. A 3-way ANOVA for cohort, age and gender of both the current and our previous data showed a significant main effect for age (p < 0.0001) but not for cohort (p = 0.134) or gender (p = 0.61).

Conclusions

Comparison of our new data with our early 1990s data and that from studies of over 8,000 Australian non-clinical rural and urban children in the 1970's and 1980's provided no evidence for the rapidly increasing prevalence of myopia described elsewhere in the world. In fact, the prevalence of myopia in Australian children continues to be significantly lower than that reported in Asia and North America despite changing demographics. This raises the issue of whether these results are a reflection of Australia's stable educational system and lifestyle over the last 30 years.
Hospital use of systemic antifungal drugs
Authors: de With Katja , Steib-Bauert Michaela , Knoth Holger , Dörje Frank , Strehl Egid , Rothe Ulrich , Maier Ludwig , Kern Winfried V
Published: February 2005

Background

Sales data indicate a major increase in the prescription of antifungal drugs in the last two decades. Many new agents for systemic use that only recently have become available are likely to be prescribed intensively in acute care hospitals. Sales data do not adequately describe the developments of drug use density. Given the concerns about the potential emergence of antifungal drug resistance, data on drug use density, however, may be valuable and are needed for analyses of the relationship between drug use and antifungal resistance.

Methods

Hospital pharmacy records for the years 2001 to 2003 were evaluated, and the number of prescribed daily doses (PDD, defined according to locally used doses) per 100 patient days were calculated to compare systemic antifungal drug use density in different medical and surgical service areas between five state university hospitals.

Results

The 3-year averages in recent antifungal drug use for the five hospitals ranged between 8.6 and 29.3 PDD/100 patient days in the medical services (including subspecialties and intensive care), and between 1.1 and 4.0 PDD/100 patient days in the surgical services, respectively. In all five hospitals, systemic antifungal drug use was higher in the hematology-oncology service areas (mean, 48.4, range, 24 to 101 PDD/100 patient days, data for the year 2003) than in the medical intensive care units (mean, 18.3, range, 10 to 33 PDD/100) or in the surgical intensive care units (mean, 10.7, range, 6 to 18 PDD/100). Fluconazole was the most prescribed antifungal drug in all areas. In 2003, amphotericin B consumption had declined to 3 PDD/100 in the hematology-oncology areas while voriconazole use had increased to 10 PDD/100 in 2003.

Conclusion

Hematology-oncology services are intense antifungal drug prescribing areas. Fluconazole and other azol antifungal drugs are the most prescribed drugs in all patient care areas while amphotericin B use has considerably decreased. The data may be useful as a benchmark for focused interventions to improve prescribing quality.
Comparison of knowledge scores of medical students in problem-based learning and traditional curriculum on public health topics
Authors: Gurpinar Erol , Musal Berna , Aksakoglu Gazanfer , Ucku Reyhan
Published: February 2005

Background

The purpose of the study was to compare the knowledge scores of medical students in Problem-based Learning and traditional curriculum on public health topics.

Methods

We planned a cross-sectional study including the fifth and sixth year medical students of Dokuz Eylul University in Turkey. The fifth year students (PBL group, n = 56) were the pioneers educated with PBL curriculum since the 1997–1998 academic year. The sixth year students (traditional education group, n = 78) were the last students educated with traditional education methods. We prepared 25 multiple-choice questions in order to assess knowledge scores of students on selected subjects of Public Health. Our data were collected in year 2002.

Results

Mean test scores achieved in PBL and traditional groups were 65.0 and 60.5 respectively. PBL students were significantly more successful in the knowledge test (p = 0.01). The knowledge scores of two topics were statistically higher among PBL students. These topics were health management and chronic diseases.

Conclusion

We found that mean total evaluation score in the PBL group was 4.5 points higher than in the traditional group in our study. Focusing only on the knowledge scores of students is the main limitation of our study. Upon the graduation of the first PBL students in the 2002–2003 academic year, we are planning additional studies regarding the other functions of a physician such as skill, behaviour and attitude.
Changes in lipids over twelve months after initiating protease inhibitor therapy among persons treated for HIV/AIDS
Authors: Levy Adrian R , McCandless Lawrence , Harrigan P Richard , Hogg Robert S , Bondy Greg , Iloeje Uchenna H , Mukherjee Jayanti , Montaner Julio S
Published: February 2005

Background

Protease inhibitors are known to alter the lipid profiles in subjects treated for HIV/AIDS. However, the magnitude of this effect on plasma lipoproteins and lipids has not been adequately quantified.

Objective

To estimate the changes in plasma lipoproteins and triglycerides occurring within 12 months of initiating PI-based antiretroviral therapy among HIV/AIDS afflicted subjects.

Methods

We included all antiretroviral naïve HIV-infected persons treated at St-Paul's Hospital, British Columbia, Canada, who initiated therapy with protease inhibitor antiretroviral (ARV) drugs between August 1996 and January 2002 and who had at least one plasma lipid measurement. Longitudinal associations between medication use and plasma lipids were estimated using mixed effects models that accounted for repeated measures on the same subjects and were adjusted for age, sex, time dependent CD4+ T-cell count, and time dependent cumulative use of non-nucleoside reverse transcriptase inhibitors and adherence. The cumulative number of prescriptions filled for PIs was considered time dependent. We estimated the changes in the 12 months following any initiation of a PI based regimen.

Results

A total of 679 eligible subjects were dispensed nucleoside analogues and PI at the initiation of therapy. Over a median 47 months of follow-up (interquartile range (IQR): 29–62), subjects had a median of 3 (IQR: 1–6) blood lipid measurements. Twelve months after treatment initiation of PI use, there was an estimated 20% (95% confidence interval: 17% – 24%) increase in total cholesterol and 22% (12% – 33%) increase in triglycerides.

Conclusions

Twelve months after treatment initiation with PIs, statistically significant increases in total cholesterol and triglycerides levels were observed in HIV-infected patients under conditions of standard treatment. Our results contribute to the growing body of evidence implicating PIs in the development of blood lipid abnormalities. In conjunction with the predominance or men, high rates of smoking, and aging of the treated HIV-positive population, elevated lipoproteins and triglycerides may mean that patients such as these are at elevated risk for cardiovascular events in the future.
Angiotensin II Enhances Insulin Sensitivity in Vitro and in Vivo
Authors: Juan Chi-Chang , Chien Yueh , Wu Liang-Yi , Yang Wei-Ming , Chang Chih-Ling , Lai Ying-Hsiu , Ho Pei-Hsuan , Kwok Ching Fai , Ho Low-Tone
Published: February 2005

The renin-angiotensin system plays a critical role in the pathogenesis of obesity, obesity-associated hypertension, and insulin resistance. However, the biological actions of angiotensin II (AII) on insulin sensitivity remain controversial. Because angiotensinogen and AII receptors are expressed on adipose tissue, we investigated the effect of AII on the insulin sensitivity of isolated rat adipocytes. The results of a receptor binding assay showed the maximal AII binding capacity of adipocytes to be 8.3 ± 0.9 fmol/7 × 106 cells and the dissociation constant to be 2.72 ± 0.11 nm. Substantial expression of both type 1 and 2 AII (AT1 and AT2) receptors was detected by RT-PCR. AII had no effect on basal glucose uptake, but significantly potentiated insulin-stimulated glucose uptake; this effect was abolished by the AT1 antagonist, losartan. In addition, AII did not alter the insulin binding capacity of adipocytes, but increased insulin-stimulated tyrosine phosphorylation of the insulin receptor β-subunit, Akt phosphorylation, and translocation of glucose transporter 4 to the plasma membrane. AII potentiated insulin-stimulated glucose uptake through the AT1 receptor and by alteration of the intracellular signaling of insulin. Intraperitoneal injection of Sprague Dawley rats with AII increased insulin sensitivity in vivo. In conclusion, we have shown that AII enhances insulin sensitivity both in vitro and in vivo, suggesting that dysregula-tion of the insulin-sensitizing effect of AII may be involved in the development of insulin resistance.
Mouse GnRH Receptor Gene Expression Is Mediated by the LHX3 Homeodomain Protein
Authors: McGillivray Shauna M. , Bailey Janice S. , Ramezani Rosha , Kirkwood Brian J. , Mellon Pamela L.
Published: February 2005

Appropriate expression of GnRH receptor (GnRHR) is necessary for the correct regulation of the gonadotropins, LH and FSH, by GnRH. GnRHR is primarily expressed in the gonadotrope cells of the anterior pituitary, and a number of regulatory elements important for both basal and hormonal regulation of the gene have been identified. Using the gonadotrope-derived cell line, αT3-1, that endogenously expresses GnRHR, we have identified an ATTA element located at −298 relative to the transcriptional start site that is essential for basal expression of the GnRHR gene. LHX3, a member of the LIM homeodomain family, binds the −298 ATTA site in vitro as well as to the endogenous GnRHR promoter in vivo. Additionally, LHX3 specifically activates through this −298 ATTA site in transient transfection assays. LHX3 is essential for pituitary development and has been implicated in the regulation of a number of pituitary specific genes; however, this is the first report identifying its role in the regulation of GnRHR.