bluuebunny/crossref_metadata_2025 huggingface dataset:
The 2006 Pittendrigh/Aschoff Lecture: New Roles for Old Proteins in the Drosophila Circadian Clock
Authors: Meyer Pablo , Young Michael W.
Published: July 2007

Circadian behaviors in the animal kingdom are regulated by a small set of conserved genes. Starting with a historical perspective focused on Drosophila, the authors describe how the recurrent discovery of circadian clock genes uncovered a molecular mechanism associated with cycling gene expression. These molecular cycles appear to emerge from delayed negative and positive feedback. The authors will then introduce a novel timing mechanism uncovered by a single cell-based assay, with the new ideas and prospects for future research that it has raised.
Random effects and latent processes approaches for analyzing binary longitudinal data with missingness: a comparison of approaches using opiate clinical trial data
Authors: Albert Paul S. , Follmann Dean A.
Published: July 2007

The analysis of longitudinal data with non-ignorable missingness remains an active area in biostatistics research. This article discusses various random effects and latent process models which have been proposed for analyzing longitudinal binary data subject to both non-ignorable intermittent missing data and dropout. These models account for non-ignorable missingness by introducing random effects or a latent process which is shared between the response model and the model for the missing-data mechanism. We discuss various random effects and latent processes approaches and compare these approaches with analyses from an opiate clinical trial data set, which had high proportion of intermittent missingness and dropout. We also compare these random effect and latent process approaches with other methods for accounting for non-ignorable missingness using this data set.
Lymphoma dissemination: the other face of lymphocyte homing
Authors: Pals Steven T. , de Gorter David J. J. , Spaargaren Marcel
Published: July 2007

The orchestration of systemic immune responses is critically dependent on coordinated lymphocyte migration and recirculation. This “homing” guides lymphocytes to the microenvironments that control their differentiation and survival, disperses the immunologic repertoire, and targets effector lymphocytes to sites of antigenic insult. Lymphocyte homing is a multistep process that requires chemotaxis and cell adhesion coupled with strategies to overcome physical barriers. At the molecular level, it is regulated by adhesion molecules and chemokines, and facilitated by intrinsic molecular programs that allow “ameboid” shape change, allowing highly effective lymphocyte traffic between different tissue compartments. In case of malignant transformation, however, the fact that lymphocytes are “licensed to move” forms a serious threat to the organism, because it permits rapid tumor dissemination irrespective of the conventional anatomic boundaries limiting early spread in most types of cancer. Thus, unlike the metastatic spread of other cancers, lymphoma dissemination generally is not a reflection of tumor progression but of conserved physiological behavior. The dissemination patterns often reflect basic rules of lymphocyte homing, explaining the strikingly tissue-specific dissemination of, for example, mucosal lymphomas, cutaneous lymphomas, and multiple myeloma. Understanding the molecular mechanisms underlying this behavior may provide novel targets for treatment of lymphoma patients.
Expression of the heparan sulfate-degrading enzyme heparanase is induced in infiltrating CD4+ T cells in experimental autoimmune encephalomyelitis and regulated at the level of transcription by early growth response gene
Authors: de Mestre Amanda M , Staykova Maria A , Hornby June R , Willenborg David O , Hulett Mark D
Published: July 2007

The heparan sulfate-cleaving enzyme heparanase (HPSE) plays an important role in remodeling of the basement membrane and extracellular matrix during inflammation. Inducible HPSE enzymatic activity has been reported in leukocytes; however, little is known of the molecular mechanisms that regulate HPSE gene expression during inflammatory disease. In this study, HPSE expression and regulation in the T cell-mediated disease model, experimental autoimmune encephalomyelitis (EAE), were investigated. Expression analysis showed that HPSE mRNA is induced in rat CD4+ antigen-specific T lymphocytes upon activation and correlates with the encephalitogenicity of the cells. Examination of the kinetics and cell type-specific expression of HPSE throughout the progression of active EAE in rats, indicated that HPSE was highly expressed in CD4+ T cells infiltrating the central nervous system (CNS) during clinical disease. Little or no HPSE expression was observed in CD8+ T cells, macrophages, or astrocytes during disease progression. To investigate the mechanism of inducible HPSE gene regulation in T cells, studies were extended into human primary T cells. HPSE mRNA, protein, and enzymatic activity were induced upon activation. Functional analysis of the human HPSE promoter identified an EGR1 binding motif that contained high inducible activity and was transactivated by EGR1. Furthermore, the treatment of primary T lymphocytes with an EGR1 siRNA inhibited inducible HPSE mRNA expression. These data provide evidence to suggest that inducible HPSE expression in primary T lymphocytes is regulated at the transcriptional level by EGR1 and is important in facilitating CD4+ T cell infiltration into the CNS to promote EAE.
Evc is a positive mediator of Ihh-regulated bone growth that localises at the base of chondrocyte cilia
Authors: Ruiz-Perez Victor L. , Blair Helen J. , Rodriguez-Andres M. Elena , Blanco Maria Jose , Wilson Amy , Liu Yu-Ning , Miles Colin , Peters Heiko , Goodship Judith A.
Published: July 2007

EVC is a novel protein mutated in the human chondroectodermal dysplasia Ellis-van Creveld syndrome (EvC; OMIM: 225500). We have inactivated Evc in the mouse and show that Evc-/- mice develop an EvC-like syndrome, including short ribs, short limbs and dental abnormalities. lacZ driven by the Evc promoter revealed that Evc is expressed in the developing bones and the orofacial region. Antibodies developed against Evc locate the protein at the base of the primary cilium. The growth plate of Evc-/- mice shows delayed bone collar formation and advanced maturation of chondrocytes. Indian hedgehog(Ihh) is expressed normally in the growth plates of Evc-/- mice, but expression of the Ihh downstream genes Ptch1 and Gli1 was markedly decreased. Recent studies have shown that Smo localises to primary cilia and that Gli3 processing is defective in intraflagellar transport mutants. In vitro studies using Evc-/- cells demonstrate that the defect lies downstream of Smo. Chondrocyte cilia are present in Evc-/- mice and Gli3 processing appears normal by western blot analysis. We conclude that Evc is an intracellular component of the hedgehog signal transduction pathway that is required for normal transcriptional activation of Ihh target genes.
Life, data, and everything
Authors: Satyro Marco A.
Published: July 2007

The use of thermodynamics for the solution of chemical and process engineering problems is determined by a blend of science, engineering, art, and grit. Although chemical engineering thermodynamics benefits from an ever-increasing body of basic scientific knowledge, the solution of real problems still depends very much on the knowledge of individuals, their creativity, and their determination to recommend solutions. The essence of success is determined by a combination of two apparently simple components-physical property data and how they are used.
Controlling structure in associating polymer-surfactant mixtures
Authors: Piculell L. , Svensson A. , Norrman J. , Bernardes J. S. , Karlsson L. , Loh W.
Published: July 2007

Structures of concentrated mixtures of associating polymer-surfactant mixtures are important in many technical applications. Yet an in-depth understanding of how molecular parameters affect these structures is lacking. We here summarize the results of ongoing work using a novel simplified approach to the study of associating oppositely charged polymer-surfactant mixtures, introducing a minimum number of components to the various mixtures. The results illustrate the relations between systems with and without polyions, as well as effects of systematic changes of parameters such as surfactant chain length, polyion length, polyion charge density, and the charge density of the surfactant aggregate.
Thermodynamic problems in structural molecular biology
Authors: Privalov Peter L.
Published: July 2007

The most essential feature of living biological systems is their high degree of structural organization. The key role is played by two linear heteropolymers, the proteins and nucleic acids. Under environmental conditions close to physiological, these biopolymers are folded into unique native conformations, genetically determined by the arrangement of their standard building blocks. In their native conformation, biological macromolecules recognize their partners and associate with them, forming specific, higher-order complexes, the "molecular machines". Folding of biopolymers into their native conformation and their association with partners is in principle a reversible, thermodynamically driven process. Investigation of the thermodynamics of these basic biological processes has prime importance for understanding the mechanisms of forming these supra-macromolecular constructions and their functioning.
Critically evaluated rate coefficients for free-radical polymerization Part 6: Propagation rate coefficient of methacrylic acid in aqueous solution (IUPAC Technical Report)
Authors: Beuermann Sabine , Buback Michael , Hesse Pascal , Kuchta Frank-Dieter , Lacík Igor , van Herk Alex M.
Published: July 2007

Critically evaluated propagation rate coefficients, k
p, for free-radical polymerization of methacrylic acid, MAA, in aqueous solution are presented. The underlying k
p values are from two independent sources, which both used the IUPAC-recommended technique of pulsed-laser-initiated polymerization (PLP) in conjunction with molar mass distribution (MMD) analysis of the resulting polymer by size-exclusion chromatography (SEC). Different methods of measuring the MMD of the poly(MAA) samples have, however, been used: (i) direct analysis via aqueous-phase SEC and (ii) standard SEC with tetrahydrofuran as the eluent carried out on poly(methyl methacrylate) samples obtained by methylation of the poly(MAA) samples from PLP. Benchmark k
p values for aqueous solutions containing 15 mass % MAA are presented for temperatures between 18 and 89 °C. The Arrhenius pre-exponential and activation energy of k
p at 15 mass % MAA are 1.54 × 106 L mol-1 s-1 and 15.0 kJ mol-1, respectively. Also reported are critically evaluated k
p values for 25 °C over the entire MAA concentration range from dilute aqueous solution to bulk polymerization.
Book Reviews
Authors: Menezes Alison Ribeiro de , Warner Robin , Buffery Helena
Published: July 2007

The Splintering of Spain: Cultural History and the Spanish Civil War, 19361939, Chris Ealham and Michael Richards (eds.), 2002 Cambridge: Cambridge University Press, 282 pp., ISBN 0521821789 (hbk), 50

Functional Approaches to Spanish Syntax: Lexical Semantics,
Discourse and Transitivity, J. Clancy Clements and Jiyoung Yoon (eds.) (2006) Basingstoke: Palgrave MacMillan, xiv + 305 pp., ISBN 1-4039-9406-4 (hbk), 55

Catalonia: History and Culture, John Payne (2004) Nottingham: Five Leaves Publications, 324 pp., ISBN 0-907123-29-5
(pbk), 9.99
The proteome of the heterocyst cell wall in Anabaena sp. PCC 7120
Authors: Moslavac Suncana , Reisinger Veronika , Berg Matthias , Mirus Oliver , Vosyka Oliver , Plöscher Matthias , Flores Enrique , Eichacker Lutz A. , Schleiff Enrico
Published: July 2007

Anabaena sp. PCC 7120 is a filamentous cyanobacterium that serves as a model to analyze prokaryotic cell differentiation, evolutionary development of plastids, and the regulation of nitrogen fixation. The cell wall is the cellular structure in contact with the surrounding medium. To understand the dynamics of the cell wall proteome during cell differentiation, the cell wall from Anabaena heterocysts was enriched and analyzed. In line with the recently proposed continuity of the outer membrane along the Anabaena filament, most of the proteins identified in the heterocyst cell-wall fraction are also present in the cell wall of vegetative cells, even though the lipid content of both membranes is different.
The structure of CMS2MS2, a mitogenic protein isolated fromCarica candamarcensis
Authors: Gomes Marco Túlio R. , Bemquerer Marcelo P. , Lopes Miriam Tereza P. , Richardson Michael , Júnior Sergio Oyama , Salas Carlos E.
Published: July 2007

In a recent study we showed that two proteinases (CMS2MS2 and CMS2MS3) fromCarica candamarcensisenhance mammalian cell proliferation. The aim of the present study is the determination of the primary structure of CMS2MS2 and prediction of its three-dimensional structure. The protein contains 214 residues, including the catalytic triad composed of Cys25, His159, and Asn175. A phylogenetic tree analysis demonstrated that CMS2MS2 ranks closer to chymopapain than to papain. The overall predicted three-dimensional structure is similar to proteinases from the papain family. These results suggest that minor structural differences within CMS2MS2 must account for its proliferative action.
Calpain proteolysis of insulin-like growth factor binding protein (IGFBP) -2 and -3, but not of IGFBP-1
Authors: Berg Ulrika , Bang Peter , Carlsson-Skwirut Christine
Published: July 2007

Calpains are cytoplasmic Ca2+-regulated cysteine proteases that may regulate insulin-like growth factor (IGF)-independent actions of insulin-like growth factor binding proteins (IGFBPs) through IGFBP proteolysis. In this study, [125I]-labeled IGFBP-2 and -3, but not IGFBP-1, were proteolyzed by Ca2+-activated m-calpain in vitro. Degradation of higher concentrations of the recombinant proteins IGFBP-2 and -3 by m-calpain was dose-dependent, but was terminated within 20 min by autolysis. By subjecting proteolytic fragments to N-terminal amino acid sequence analysis, the primary cleavage sites in IGFBP-2 and -3 were localized to the non-conserved central linker regions. Using the biosensor technique, in vitro binding of m-calpain to IGFBP-3 was demonstrated to be a Ca2+-dependent reaction with a rapid on/off rate.
Protein import into chloroplasts: new aspects of a well-known topic
Authors: Stengel Anna , Soll Jürgen , Bölter Bettina
Published: July 2007

Protein import into plant chloroplasts is a fascinating topic that is being investigated by many research groups. Since the majority of chloroplast proteins are synthesised as precursor proteins in the cytosol, they have to be posttranslationally imported into the organelle. For this purpose, most preproteins are synthesised with an N-terminal presequence, which is both necessary and sufficient for organelle recognition and translocation initiation. The import of preproteins is facilitated by two translocation machineries in the outer and inner envelope of chloroplasts, the Toc and Tic complexes, respectively. Translocation of precursor proteins across the envelope membrane has to be highly regulated to react to the metabolic requirements of the organelle. The aim of this review is to summarise the events that take place at the translocation machineries that are known so far. In addition, we focus in particular on alternative import pathways and the aspect of regulation of protein transport at the outer and inner envelope membrane.
PqsA is required for the biosynthesis of 2,4-dihydroxyquinoline (DHQ), a newly identified metabolite produced by Pseudomonas aeruginosa and Burkholderia thailandensis
Authors: Lépine François , Dekimpe Valérie , Lesic Biliana , Milot Sylvain , Lesimple Alain , Mamer Orval A. , Rahme Laurence G. , Déziel Eric
Published: July 2007

A new metabolite, 2,4-dihydroxyquinoline (DHQ), was identified in cultures of the bacteria Pseudomonas aeruginosa and Burkholderia thailandensis. We found that the biosynthesis of DHQ correlates with the presence of a functional PqsA, which is a product of the pqsABCDE operon responsible for the synthesis of 4-hydroxy-2-alkylquinolines (HAQs) in P. aeruginosa. However, DHQ is not a degradation product or precursor of HAQs. This finding sheds some light on the poorly understood biosynthesis pathway of HAQs, which includes important communication signals regulating the expression of virulence factors.
Characterization of NADPH oxidase 5 in equine testis and spermatozoa
Authors: Sabeur K , Ball B A
Published: July 2007

Reactive oxygen species (ROS) play an important role in normal sperm function, and spermatozoa possess specific mechanisms for ROS generation via an NAD(P)H-dependent oxidase. The aim of this study was to identify the presence of an NADPH oxidase 5 (NOX5) in equine testis and spermatozoa. The mRNA of NOX5 was expressed in equine testis as detected by northern blot probed with human NOX5 cDNA and by RT-PCR. Immunoblotting with affinity purified α-NOX5 revealed one major protein in equine testis and other tissues. Immunolocalization of NOX5 showed labeling over the rostral sperm head with some labeling in the equatorial and post-acrosomal regions. In the testis, there was abundant staining in the adluminal region of the seminiferous tubules associated with round and elongating spermatids. The RT-PCR and sequence analysis revealed a high homology with human NOX5. This study demonstrates that NOX5 is present in equine spermatozoa and testes and therefore represents a potential mechanism for ROS generation in equine spermatozoa.
In vitro development of mouse fetal germ cells into mature oocytes
Authors: Shen Wei , Li Lan , Bai Zhaodai , Pan Qingjie , Ding Mingxiao , Deng Hongkui
Published: July 2007

Little is known about the mechanisms underlying primordial follicular formation and the acquisition of competence to resume meiosis by growing oocytes. It is therefore important to establish an in vitro experimental model that allows one to study such mechanisms. Mouse follicular development has been studied in vitro over the past several years; however, no evidence has been presented showing that mature oocytes can be obtained from mouse fetal germ cells prior to the formation of primordial follicles. In this study, a method has been established to obtain mature oocytes from the mouse fetal germ cells at 16.5 days postcoitum (dpc). From the initiation of primordial follicular formation to the growth of early secondary follicles, ovarian tissues from 16.5 dpc fetal mice were cultured in vitro for 14 days. Subsequently, 678 intact secondary follicles were isolated from 182 mouse fetal ovaries and cultured for 12 days. A total of 141 oocytes inside antral follicles were matured in vitro, and 102 oocytes underwent germinal vesicle breakdown. We found that 97 oocytes were fertilized and 15 embryos were able to form morula–blastocysts. We also analyzed various genomic imprinting markers and showed that the erasure of genomic imprinting markers in the parental generation was also imposed on the oocytes that developed from fetal germ cells. Our results demonstrate that mouse fetal germ cells are able to form primordial follicles with ovarian cells, and that oocytes within the growing follicles are able to mature normally in vitro.
Expression localisation and functional activity of pituitary adenylate cyclase-activating polypeptide, vasoactive intestinal polypeptide and their receptors in mouse ovary
Authors: Barberi Marzia , Muciaccia Barbara , Morelli Maria Beatrice , Stefanini Mario , Cecconi Sandra , Canipari Rita
Published: July 2007

Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) positively affect several parameters correlated with the ovulatory process. PACAP is transiently expressed in rat preovulatory follicles, while VIP is present in nerve fibres at all stages of development. These two peptides act by interacting with three types of receptors: PACAP type I receptor (PAC1-R), which binds with higher affinity to PACAP, and two VIP receptors (VPAC1-R and VPAC2-R), which bind to PACAP and VIP with equal affinity. The aim of the present study was to characterise the PACAP/VIP/receptor system in the mouse ovary. Results obtained by RT-PCR, immunohistochemistry and in situ hybridisation showed that PACAP was transiently expressed in granulosa cells of preovulatory follicles after human chorionic gonadotrophin (hCG) stimulation, while VIP mRNA was never observed. All the receptors were present in 22-day-old untreated mice. In preovulatory follicles, PAC1-R was expressed both in granulosa cells and in residual ovarian tissue but was stimulated by hCG mainly in granulosa cells; VPAC2-R was present in both the cell compartments and was only mildly stimulated; VPAC1-R was present mainly in the residual ovarian tissue and was downregulated by hCG. PACAP and VIP were equipotent in inhibiting apoptosis in granulosa cells, confirming the presence of functional PACAP/VIP receptors. The contemporary induction by hCG of PACAP and PAC1-R in granulosa cells of preovulatory follicles suggests that, also in mouse ovary, PACAP may play a significant role around the time of ovulation. Moreover, the presence of PACAP/VIP receptors in the untreated ovary suggests a possible role for PACAP and VIP during follicle development.
p53 regulates cyclophosphamide teratogenesis by controlling caspases 3, 8, 9 activation and NF-κB DNA binding
Authors: Pekar Olga , Molotski Nataly , Savion Shoshana , Fein Amos , Toder Vladimir , Torchinsky Arkady
Published: July 2007

The tumor suppressor protein p53 regulates the sensitivity of embryos to such human teratogens as ionizing radiation, diabetes, and cytostatics. Yet, the molecular mechanisms whereby it fulfills this function remain undefined. We used p53 heterozygous (p53+/−) female mice mated with p53+/− males and then exposed to cyclophosphamide (CP) to test whether caspases 3, 8, and 9 and the transcription factor nuclear factor (NF)-κB may serve as p53 targets. Mice were exposed to CP on day 12 of pregnancy and killed on days 15 and 18 of pregnancy to evaluate CP-induced teratogenic effect. The brain and limbs of embryos harvested 24 h after CP treatment were used to evaluate NF-κB (p65) DNA-binding activity by an ELISA-based method, the activity of the caspases by appropriate colorimetric kits, apoptosis, and cell proliferation by TUNEL, and 5′-bromo-2′-deoxyuridine incorporation respectively. We observed that the activation of caspases 3, 8, and 9 and the suppression of NF-κB DNA binding following CP-induced teratogenic insult took place only in teratologically sensitive organs of p53+/+ but not p53−/− embryos. CP-induced apoptosis and suppression of cell proliferation were also more intensive in the former, and they exhibited a higher incidence of structural anomalies, such as open eyes, digit, limb, and tail anomalies. The analysis of the correlations between the p53 embryonic genotype, the activity of the tested molecules, and the CP-induced dysmorphic events at the cellular and organ level suggests caspases 3, 8, and 9 and NF-κB as components of p53-targeting mechanisms in embryos exposed to the teratogen.
Actions of anti-Müllerian hormone on the ovarian transcriptome to inhibit primordial to primary follicle transition
Authors: Nilsson Eric , Rogers Natalie , Skinner Michael K
Published: July 2007

The oocytes found within the primordial follicles of mammalian ovaries remain quiescent for months to years until they receive the appropriate signals to undergo the primordial to primary follicle transition and initiate folliculogenesis. The molecular mechanisms and extracellular signaling factors that regulate this process remain to be fully elucidated. The current study investigates the mechanisms utilized by anti-Müllerian hormone (AMH; i.e. Müllerian inhibitory substance) to inhibit the primordial to primary follicle transition. Ovaries from 4-day-old rats were placed into organ culture and incubated in the absence or presence of AMH, either alone or in combination with known stimulators of follicle transition, including basic fibroblast growth factor (bFGF), kit ligand (KITL), or keratinocyte growth factor (KGF). Following 10 days of culture, the ovaries were sectioned, stained, and morphologically evaluated to determine the percentage of primordial versus developing follicles. As previously demonstrated, AMH treatment decreased primordial to primary follicle transition. Interestingly, AMH inhibited the stimulatory actions of KITL, bFGF, and KGF. Therefore, AMH can inhibit the basal and stimulated development of primordial follicles. To investigate the mechanism of AMH actions, the influence AMH has on the ovarian transcriptome was analyzed. AMH treatment when compared with controls was found to alter the expression of 707 genes. The overall effect of AMH exposure is to decrease the expression of stimulatory factors, increase the expression of inhibitory factors, and regulate cellular pathways (e.g. transforming growth factor β signaling pathway) that result in the inhibition of primordial follicle development. Analysis of the regulatory factors and cellular pathways altered by AMH provides a better understanding of the molecular control of primordial follicle development.
Short-term transplantation of isolated human ovarian follicles and cortical tissue into nude mice
Authors: Dolmans Marie-Madeleine , Martinez-Madrid Belen , Gadisseux Elodie , Guiot Yves , Yuan Wu Yuan , Torre Antoine , Camboni Alessandra , Van Langendonckt Anne , Donnez Jacques
Published: July 2007

This study was designed to evaluate follicular survival and growth after short-term transplantation of fresh isolated human follicles and ovarian cortical tissue to nude mice. Ovarian biopsies were obtained from nine women undergoing laparoscopy. Twelve nude mice were xenografted with an ovarian cortical fragment in the right ovarian bursa, and a clot containing isolated follicles in the left, for a period of 7 days. One ungrafted fragment was used as a control. Histological sections were analyzed to determine follicle number and stage. The proliferative status of follicular cells was assessed by Ki-67 immunostaining. A total of 659 follicles was analyzed by histology and 545 follicles by immunohistochemistry. The percentage of primordial follicles was found to be markedly reduced 1 week post-grafting when compared with ungrafted tissue, while the percentage of primary follicles had significantly increased. Only 8% of follicles showed Ki-67-positive granulosa cells before grafting, whereas 1 week after grafting, 71% of follicles in fragments and 67% of isolated follicles were Ki-67-positive (P<0.001). Moreover, the histological aspect of isolated follicle grafts was similar to that of grafted fragments: follicles were surrounded by vimentin-positive stroma-like tissue of human origin, as confirmed by fluorescent in situ hybridization with human-specific probes. Our results demonstrate, for the first time, that isolated human follicles are able to survive and grow after xenografting. This study also shows massive in vivo follicular activation after transplantation of grafted fragments and isolated follicles. One week after grafting, well-structured stroma-like tissue of human origin was observed around the isolated follicles. The potential origin of this stroma is discussed.
Role of estrogen in induction of penile dysmorphogenesis: a review
Authors: Goyal H O , Braden T D , Williams C S , Williams J W
Published: July 2007

In this review, we report permanent dysmorphogenesis of the penis and loss of fertility in adult rats treated neonatally with estrogen. Specifically, we report replacement of smooth muscle cells and cavernous spaces by fat cells in the corpus cavernosum penis, but not in the adjoining corpus spongiosum. Induction of these novel, region-specific phenotypes is dose-dependent, requires a critical window of exposure and associated with decreased testosterone and up-regulation of estrogen receptor α (ERα). The resistance of ERα knockout mice to develop these abnormalities implies an unequivocal role for ERα in mediating maldevelopment of the penis. Additionally, the prevention of estrogen-inducible penile abnormalities by ER antagonist ICI 182 780 implies that a functional ER-mediated pathway is essential for inducing penile abnormalities. Likewise, the ability of testosterone or dihydrotestosterone to negate these abnormalities suggests a role for an androgen receptor (AR)-mediated pathway. Taken together, these observations led us to hypothesize that neonatal estrogen exposure, via an ER-mediated pathway (direct action) or an AR-mediated pathway (indirect action through decreased testosterone) or both pathways, up-regulates ERα expression in stromal cells of the penis, which are then reprogrammed such that their differentiation into smooth muscle cells is inhibited and their differentiation into adipocytes is stimulated.
Loss of Glycemic Control in Patients with Type 2 Diabetes Mellitus Who Were Receiving Initial Metformin, Sulfonylurea, or Thiazolidinedione Monotherapy
Authors: Riedel Aylin A. , Heien Herbert , Wogen Jenifer , Plauschinat Craig A.
Published: July 2007

Study Objectives. To examine glycosylated hemoglobin (A1C) values longitudinally in patients who newly started metformin, sulfonylurea, or thiazolidinedione monotherapy; in a subset of patients whose A1C values were 7% or greater before starting therapy (baseline) and who achieved A1C goal (A1C < 7%) during therapy, rates of secondary failure (i.e., A1C value returned to ≥ 7% during therapy) were compared for each drug.

Design. Four‐year retrospective analysis.

Data Source. Administrative database from a large health care plan.

Patients. Patients who filled at least one prescription for metformin (5453 patients), sulfonylurea (2373), and thiazolidinedione (1590) therapy, respectively, between January 1, 2001, and March 31, 2004, were enrolled.

Measurements and Main Results. Patients' demographic and clinical characteristics, baseline A1C values, changes in A1C values (last available result during follow‐up minus baseline value), and A1C values before and after the addition of an antidiabetic drug other than the index drug (therapy intensification) were documented. Mean age was 50.7 years; 5027 (53.4%) were men. Mean baseline A1C value was 8.4%, and about 70% of patients had an AIC value of 7% or greater before starting therapy. Mean follow‐up was 1.9 years, and mean decrease in A1C values was 1.47% (to 6.91%). The probabilities of attaining A1C goals were similar for patients receiving metformin, sulfonylurea, or thiazolidinedione therapy. The rate of therapy intensification among patients taking metformin (24.7%) was lower than that of patients taking a sulfonylurea (30.1%, p<0.001) but similar to that of those taking a thiazolidinedione (24.6%). Secondary failure occurred in 36.3% of patients; mean time from the start of therapy to its failure was about 1.51 years. Patients receiving a sulfonylurea were 1.25 (95% confidence interval [CI] 1.05–1.50) times more likely than patients receiving metformin to experience secondary failure, whereas failure rates were similar for thiazolidinediones and metformin (odds ratio 0.78, 95% CI 0.62–0.99).

Conclusion. In the subset of patients assessed for secondary failure, although treatment initially reduced A1C values, more than one third experienced failure. Real‐world studies of A1C goal attainment must follow patients on a long‐term basis to assess the maintenance of glycemic control over time.
Hemodynamic and Cognitive Effects of Lofexidine and Methadone Coadministration: A Pilot Study
Authors: Schroeder Jennifer R. , Schmittner John , Bleiberg Joseph , Epstein David H. , Krantz Mori J. , Preston Kenzie L.
Published: July 2007

Study Objective. To determine the hemodynamic and cognitive effects of lofexidine and methadone coadministration.

Design. Prospective, double‐blind study.

Setting. Outpatient drug treatment research clinic.

Subjects. Fourteen participants (aged 18–45 yrs) with physical dependence on opioids.

Intervention. Subjects were stabilized on methadone maintenance therapy, starting with 30 mg/day and increasing by 10‐mg/day increments, based on each subject's tolerability to achieve a target dose of 80 mg/day. After 3 weeks of methadone stabilization, lofexidine 0.4 mg/day or matching placebo were coadministered with methadone, in doses escalating by 0.2‐mg/week increments, to achieve a target dose of 1.6 mg/day over the next 8 weeks.

Measurements and Main Results. Acute orthostatic vital signs and neuropsychological effects of lofexidine and methadone coadministration were monitored for 5 hours after the dose on the first day of each new lofexidine dose. Orthostatic vital signs and adverse events were assessed daily thereafter to determine the effects of repeated doses. Lofexidine significantly decreased sitting systolic and diastolic blood pressure (p=0.045 and p=0.033, respectively) compared with placebo (i.e., methadone alone). With lofexidine 0.4 mg/day, mean decreases in systolic and diastolic blood pressure were 27 ± 17 and 15 ± 16 mm Hg, respectively. No significant association was noted between changes in orthostatic vital signs and lofexidine dose. Decreased cognitive efficiency was associated with lofexidine administration, and higher lofexidine doses adversely affected performance on a mathematical task compared with placebo (p=0.0035). The rate of adverse events was no higher with lofexidine than with placebo; the majority (54.3%) were common adverse effects of lofexidine.

Conclusion. Significant changes in hemodynamic and cognitive efficiency were observed with coadministration of lofexidine and methadone compared with methadone alone. When patients receiving methadone are prescribed lofexidine, they should be closely monitored for cardiovascular and cognitive changes.
Antiplatelet Therapy in Patients with Unstable Angina and Non–ST‐Segment‐Elevation Myocardial Infarction: Findings from the CRUSADE National Quality Improvement Initiative
Authors: Bottorff Michael B. , Nutescu Edith A. , Spinler Sarah
Published: July 2007

Evidence‐based clinical practice guidelines encapsulate current knowledge to guide health care professionals in the treatment of patients with unstable angina or non–ST‐segment‐elevation myocardial infarction (NSTEMI), yet adherence to guideline recommendations is suboptimal. Guideline adherence may be improved by quality improvement programs such as the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation?) National Quality Improvement Initiative of the American College of Cardiology–American Heart Association Guidelines. The CRUSADE data have been analyzed to demonstrate that overall guideline adherence is directly associated with mortality and that improvement in guideline adherence saves lives. Also, the CRUSADE data have determined that the real‐life mortality risk associated with unstable angina and NSTEMI is greater than suggested by clinical trials. The newer antiplatelet drugs recommended in early intervention and discharge treatment strategies are underused across many segments of the unstable angina–NSTEMI population. Glycoprotein IIb‐IIIa inhibitors are underused in high‐risk populations, and clopidogrel is markedly underused in patients who are medically managed rather than undergoing percutaneous coronary intervention or coronary artery bypass graft surgery. In addition, often the specialty of the treating physician and the status of the hospital influence the use of antiplatelet therapy. The reasons for underprescribing of antiplatelet drugs by physicians are not entirely clear but may be related to a lack of guideline familiarity and understanding, as well as factors such as drug novelty, safety, and cost. Continued education and data dissemination are therefore vital in promoting the prescription of guideline‐recommended drugs, both in the early hospitalization phase and as patients transition to community‐based care. The role of the pharmacist is pivotal in ensuring adherence to clinical guidelines by interacting with both the physician and patient.
Hair Loss Induced by Lopinavir‐Ritonavir
Authors: Borrás‐Blasco Joaquín , Belda Alberto , Rosique‐Robles Dolores , Casterá Elvira , Abad Javier , Amorós‐Quiles Isabel
Published: July 2007

A 38‐year‐old Caucasian woman with uncontrolled human immunodeficiency virus (HIV) infection was treated with highly active antiretroviral therapy (HAART) consisting of zidovudine, lamivudine, and nevirapine. Because her therapeutic response was inadequate, the HAART regimen was changed to abacavir, lamivudine, and lopinavir‐ritonavir. Three months after this therapy was started, the patient developed progressive and notable hair loss. Her hair became fair and thin, and her appearance deteriorated considerably. Hair loss due to HAART was diagnosed. Lopinavir‐ritonavir was stopped, and efavirenz was substituted; abacavir and lamivudine were continued. After 4 weeks, her hair growth substantially improved, as evidenced by rapid growth of new hair. Her general condition also improved. No relapse was observed with the new HAART regimen, and the patient's hair loss completely reversed in 8 weeks. Alopecia is a possible adverse event in HIV‐infected patients treated with protease inhibitors, particularly indinavir. Our patient's severe and generalized alopecia was temporally related to the initiation and discontinuation of lopinavir‐ritonavir. On the basis of the Naranjo adverse drug reaction probability scale, the adverse reaction was considered probable. Although generalized hair loss due to lopinavir‐ritonavir is rare, clinicians should be aware of this potential adverse reaction of this widely used drug. If alopecia is severe or particularly distressing to the patient, the offending drug should be discontinued, and therapy with another HIV drug should be started.
The Role of the Donor in the Repair of the Marrow Vascular Niche Following Hematopoietic Stem Cell Transplant
Authors: Slayton William B. , Li Xiao-Miao , Butler Jason , Guthrie Steven M. , Jorgensen Marda L. , Wingard John R. , Scott Edward W.
Published: July 2007

Bone marrow sinusoids maintain homeostasis between developing hematopoietic cells and the circulation, and they provide niches for hematopoietic progenitors. Sinusoids are damaged by chemotherapy and radiation. Hematopoietic stem cells (HSCs) have been shown to produce endothelial progenitor cells that contribute to the repair of damaged blood vessels. Because HSCs home to the marrow during bone marrow transplant, these cells may play a role in repair of marrow sinusoids. Here, we explore the role of donor HSCs in the repair of damaged sinusoids following hematopoietic stem cell transplant. We used three methods to test this role: (a) expression of platelet endothelial cell adhesion molecule to identify endothelial progenitors and the presence of the Y chromosome to identify male donor cells in female recipients; (b) presence of the Y chromosome to identify male donor cells in female recipients, and expression of the panendothelial marker mouse endothelial cell antigen-32 to identify sinusoidal endothelium; and (c) use of Tie-2/green fluorescent protein mice as donors or recipients and presence of Dil-Ac-LDL to identify sinusoids. We found that sinusoids were predominantly host-derived posttransplant. Donor cells spread along the marrow vasculature early post-transplant in a pattern that matched stromal-derived factor-1 expression. Furthermore, these engrafting progenitors were positioned to provide physical support, as well as growth and survival signals in the form of vascular-endothelial growth factor-A. Occasionally, donor cells provide cellular “patches” in the damaged sinusoids, although this occurred at a low level compared with hematopoietic engraftment. Donor support for the repair of the marrow vascular niche may be a critical first step of hematopoietic engraftment.

Disclosure of potential conflicts of interest is found at the end of this article.
CD45-Positive Blood Cells Give Rise to Uterine Epithelial Cells in Mice
Authors: Bratincsák András , Brownstein Michael J. , Cassiani-Ingoni Riccardo , Pastorino Sandra , Szalayova Ildikó , Tóth Zsuzsanna E. , Key Sharon , Németh Krisztián , Pickel James , Mezey Éva
Published: July 2007

The uterine endometrium is composed of epithelial and stromal cells, which undergo extensive degeneration and regeneration in every estrous cycle, and dramatic changes occur during pregnancy. The high turnover of cells requires a correspondingly high level of cell division by progenitor cells in the uterus, but the character and source of these cells remain obscure. In the present study, using a novel transgenic mouse, we showed that CD45-positive hematopoietic progenitor cells colonize the uterine epithelium and that in pregnancy more than 80% of the epithelium can derive from these cells. Since we also found green fluorescent protein (GFP)-positive uterine endothelial cells in long-term GFP bone marrow-transplanted mice, we conclude that circulating CD45+ cells play an important role in regenerating the uterine epithelium.

Disclosure of potential conflicts of interest is found at the end of this article.
Chondrogenic Differentiation of Human Bone Marrow Stem Cells in Transwell Cultures: Generation of Scaffold-Free Cartilage
Authors: Murdoch Alan D. , Grady Lisa M. , Ablett Matthew P. , Katopodi Theoni , Meadows Roger S. , Hardingham Tim E.
Published: July 2007

Human bone marrow stem cells (hMSCs) have been shown to differentiate in vitro into a number of cell lineages and are a potential autologous cell source for the repair and replacement of damaged and diseased musculoskeletal tissues. hMSC differentiation into chondrocytes has been described in high-density cell pellets cultured with specific growth and differentiation factors. We now describe how culture of hMSCs as a shallow multicellular layer on a permeable membrane over 2–4 weeks resulted in a much more efficient formation of cartilaginous tissue than in established chondrogenic assays. In this format, the hMSCs differentiated in 14 days to produce translucent, flexible discs, 6 mm in diameter by 0.8–1 mm in thickness from 0.5 × 106 cells. The discs contained an extensive cartilage-like extracellular matrix (ECM), with more than 50% greater proteoglycan content per cell than control hMSCs differentiated in standard cell pellet cultures. The disc constructs were also enriched in the cartilage-specific collagen II, and this was more homogeneously distributed than in cell pellet cultures. The expression of cartilage matrix genes for collagen type II and aggrecan was enhanced in disc cultures, but improved matrix production was not accompanied by increased expression of the transcription factors SOX9, L-SOX5, and SOX6. The fast continuous growth of cartilage ECM in these cultures up to 4 weeks appeared to result from the geometry of the construct and the efficient delivery of nutrients to the cells. Scaffold-free growth of cartilage in this format will provide a valuable experimental system for both experimental and potential clinical studies.

Disclosure of potential conflicts of interest is found at the end of this article.
MULTI‐SCALE VARIATION IN FINE‐ROOT BIOMASS IN A TROPICAL RAIN FOREST: A SEVEN‐YEAR STUDY
Authors: Espeleta J. F. , Clark D. A.
Published: July 2007

Understanding the dependency of ecosystem processes on spatial and temporal scales is crucial in current efforts to model ecosystem responses to global change. Here we present a case of nonlinear interactions between temporal and spatial scales in a high spatial‐ and temporal‐resolution study of fine‐root biomass responses to edaphic and climatic variation in a lowland tropical rain forest (La Selva, Costa Rica). The spatiotemporal variation in fine roots in this forest was considerably greater than that for aboveground live biomass and litterfall. Standing stocks of both live and dead fine roots varied strongly during a seven‐year period (up to 10‐fold) and across two edaphic gradients with different soil nutrient and water variation (up to four‐fold). Fine‐root biomass decreased with soil fertility and volumetric soil water content, but responses across a landscape gradient (decreasing with total soil P and K and increasing with N:P ratio between two Oxisols with different weathering) differed from those across a topographic gradient in older Oxisols (increasing with total Fe and Al and decreasing with Ca, Mg, and C:N ratio down the slopes). The spatial contrasts across the landscape gradient (but not in the topographic gradient) changed substantially through time, and they, in fact, disappeared entirely by the middle of the study interval. Short‐term monitoring of belowground standing biomass could thus lead to important biases when quantifying root responses. The positive time × gradient interaction in fine‐root biomass across soil types (but not downslope) also indicates nonlinear changes in spatial patterns across temporal scales, so studies on temporal responses also need to be spatially explicit at narrow scales. This interaction also appears to be more complex than previously recognized: semester‐averaged fine‐root biomass was negatively correlated with soil water content in the preceding semester, but the relationship was restricted to residual Oxisols. To increase the accuracy of global carbon cycle models in the future, a critical complement to observations of ecosystem processes at regional and global scales will be quantifying these processes through multiple years and across the substantial edaphic gradients that typically exist within landscapes.
SAVANNA RESPONSES TO FERAL BUFFALO IN KAKADU NATIONAL PARK, AUSTRALIA
Authors: Petty Aaron M. , Werner Patricia A. , Lehmann Caroline E. R. , Riley Jan E. , Banfai Daniel S. , Elliott Louis P.
Published: July 2007

Savannas are the major biome of tropical regions, spanning 30% of the Earth's land surface. Tree : grass ratios of savannas are inherently unstable and can be shifted easily by changes in fire, grazing, or climate. We synthesize the history and ecological impacts of the rapid expansion and eradication of an exotic large herbivore, the Asian water buffalo (Bubalus bubalus), on the mesic savannas of Kakadu National Park (KNP), a World Heritage Park located within the Alligator Rivers Region (ARR) of monsoonal north Australia. The study inverts the experience of the Serengeti savannas where grazing herds rapidly declined due to a rinderpest epidemic and then recovered upon disease control.

Buffalo entered the ARR by the 1880s, but densities were low until the late 1950s when populations rapidly grew to carrying capacity within a decade. In the 1980s, numbers declined precipitously due to an eradication program. We show evidence that the rapid population expansion and sudden removal of this exotic herbivore created two ecological cascades by altering ground cover abundance and composition, which in turn affected competitive regimes and fuel loads with possible further, long‐term effects due to changes in fire regimes. Overall, ecological impacts varied across a north–south gradient in KNP that corresponded to the interacting factors of precipitation, landform, and vegetation type but was also contingent upon the history of buffalo harvest. Floodplains showed the greatest degree of impact during the period of rapid buffalo expansion, but after buffalo removal, they largely reverted to their prior state. Conversely, the woodlands experienced less visible impact during the first cascade. However, in areas of low buffalo harvest and severe impact, there was little recruitment of juvenile trees into the canopy due to the indirect effects of grazing and high frequency of prescribed fires once buffalo were removed. Rain forests were clearly heavily impacted during the first cascade, but the long term consequences of buffalo increase and removal remain unclear. Due to hysteresis effects, the simple removal of an exotic herbivore was not sufficient to return savanna systems to their previous state.