bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategies for Study of the Role of Cycling on Antimicrobial Use and Resistance
Authors: McGowan John E.
Published: February 2006

Resistant bacteria usually are seen first in the intensive care unit and other acute-care areas. Thus, strategies to control these organisms often are first tested in these healthcare settings. Frequent among these strategies are attempts to improve antimicrobial use. One proposed method to decrease resistance in special settings like the intensive care unit is the cycling or rotation of antimicrobials. This intervention must be evaluated in the context of other concomitant attempts to improve antimicrobial usage and must take into account other factors influencing resistance.

Until such studies are done, the value of cycling and other efforts to limit prescribers' choices of drugs in endemic settings will be unclear. Studies to evaluate cycling will have to be of large scale to produce useful data. It is unlikely that many hospitals or healthcare systems will have sufficient resources on their own to develop studies of sufficient power to be applied widely. Thus, cooperative studies to provide data on this important issue should be an international priority.
Immunology and Homeopathy. 2. Cells of the Immune System and Inflammation
Authors: Bellavite Paolo , Conforti Anita , Pontarollo Francesco , Ortolani Riccardo
Published: February 2006

Here we describe the results of some experimental laboratory studies aimed at verifying the efficacy of high dilutions of substances and of homeopathic medicines in models of inflammation and immunity. Studies carried out on basophils, lymphocytes, granulocytes and fibroblasts are reviewed. This approach may help to test under controlled conditions the main principles of homeopathy such as ‘similarity’ of drug action at the cellular level and the effects of dilution/dynamization on the drug activity. The current situation is that few and rather small groups are working on laboratory models for homeopathy. Regarding the interpretation of data in view of the simile principle, we observe that there are different levels of similarity and that the laboratory data give support to this principle, but have not yet yielded the ultimate answer to the action mechanism of homeopathy. Evidence of the biological activity in vitro of highly diluted‐dynamized solutions is slowly accumulating, with some conflicting reports. It is our hope that this review of literature unknown to most people will give an original and useful insight into the ‘state‐of‐the‐art’ of homeopathy, without final conclusions ‘for’ or ‘against’ this modality. This kind of uncertainty may be difficult to accept, but is conceivably the most open‐minded position now.
Application of sequence-based methods in human microbial ecology
Authors: Weng Li , Rubin Edward M. , Bristow James
Published: February 2006

Ecologists studying microbial life in the environment have recognized the enormous complexity of microbial diversity for many years, and the development of a variety of culture-independent methods, many of them coupled with high-throughput DNA sequencing, has allowed this diversity to be explored in ever-greater detail. Despite the widespread application of these new techniques to the characterization of uncultivated microbes and microbial communities in the environment, their application to human health and disease has lagged. Because DNA-based techniques for defining uncultured microbes allow not only cataloging of microbial diversity but also insight into microbial functions, investigators are beginning to apply these tools to the microbial communities that abound on and within us, in what has aptly been called “the second Human Genome Project.” In this review we discuss the sequence-based methods for microbial analysis that are currently available and their application to identify novel human pathogens, improve diagnosis of known infectious diseases, and advance understanding of our relationship with microbial communities that normally reside in and on the human body.
Dynamic evolution at pericentromeres
Authors: Hall Anne E. , Kettler Gregory C. , Preuss Daphne
Published: February 2006

Pericentromeres are exceptional genomic regions: in animals they contain extensive segmental duplications implicated in gene creation, and in plants they sustain rearrangements and insertions uncommon in euchromatin. To examine the mechanisms and patterns of plant pericentromere evolution, we compared pericentromere sequence from four Brassicaceae species separated by <15 million years (Myr). This flowering plant family is ideal for studying relationships between genome reorganization and pericentromere evolution—its members have undergone recent polyploidization and hybridization, with close relatives changing in genome size and chromosome number. Through sequence and hybridization analyses, we examined regions from Arabidopsis arenosa, Capsella rubella, and Olimarabidopsis pumila that are homologous to Arabidopsis thaliana pericentromeres (peri-CENs) III and V, and used FISH to demonstrate they have been maintained near centromere satellite arrays in each species. Sequence analysis revealed a set of highly conserved genes, yet we discovered substantial differences in intergenic length and species-specific changes in sequence content and gene density. We discovered that A. thaliana has undergone recent, significant expansions within its pericentromeres, in some cases measuring hundreds of kilobases; these findings are in marked contrast to euchromatic segments in these species that exhibit only minor length changes. While plant pericentromeres do contain some duplications, we did not find evidence of extensive segmental duplications, as has been documented in primates. Our data support a model in which plant pericentromeres may experience selective pressures distinct from euchromatin, tolerating rapid, dynamic changes in structure and sequence content, including large insertions of mobile elements, 5S rDNA arrays and pseudogenes.
Issue Saliency and Gender Stereotypes: Support for Women as Presidents in Times of War and Terrorism*
Authors: Falk Erika , Kenski Kate
Published: February 2006

Objective.This article examines how issue saliency affects the public's perceptions of whether a man or a woman would make a better president when considering the most important problem facing the nation.

Method.The study uses telephone survey data of adults in the United States collected by the Annenberg Public Policy Center in September 2003. Multinominial logistic regression models were conducted to parse out the effects of issue saliency on presidential gender preference while taking demographic characteristics and party identification into account.

Results.People who said that terrorism, homeland security, and/or U.S. involvement in Iraq was the most important problem facing the nation were more likely to say that a man would do a better job handling the issue as president.

Conclusion.This study finds that issue saliency affects presidential gender preference above and beyond demographic and party identification variables.
Socioeconomic Distinction, Cultural Tastes, and Cigarette Smoking*
Authors: Pampel Fred C.
Published: February 2006

Objectives.The inverse relationship between socioeconomic status (SES) and smoking is typically seen in terms of the greater economic and social resources of advantaged groups, but it may also relate to cultural resources. This study aims to test theories of symbolic distinction by examining relationships between smoking and ostensibly unrelated cultural preferences.

Methods.Using the 1993 General Social Survey, ordinal logistic regression models, and a three‐category dependent variable (never, former, and current smoker), the analysis estimates relationships of musical likes and dislikes with smoking while controlling for SES and social strain.

Results.Preferences for classical music are associated with lower smoking, while preferences for bluegrass, jazz, and heavy metal music are associated with higher smoking.

Conclusions.The results suggest that SES groups may use smoking, like other cultural tastes, to distinguish their lifestyles from those of others.
Ideological Extremism and Public Participation*
Authors: Whitford Andrew B. , Yates Jeff , Ochs Holona L.
Published: February 2006

Objectives. Does aggregate ideological extremism reduce public participation? Does participation in governance processes fall when the social environment shifts to the extreme left or the extreme right of the political spectrum? Our main hypothesis is that the aggregate ideological orientation of the social environment constrains volunteerism in social regulatory programs.

Methods. We test our hypothesis using a panel tobit analysis of data from the federal Long‐Term Care Ombudsman Program.

Results. Our model of public participation (expressed as volunteerism) shows that participation expands when the ideological position of a state's citizens is at the extreme left or right of the political continuum. We show the differential effects of two types of aggregate ideological orientation: of citizens and their political leaders. We further find that participation is greatest in states with extremely liberal citizen ideological positions.

Conclusions. These findings paint a more complex picture of the effect of extremism in the social environment on public participation measured as production volunteerism. In sum, public participation is greatest when the social environment is ideologically polarized, and social regulation is strongest when volunteerism is greatest.
Which Congregations Will Take Advantage of Charitable Choice? Explaining the Pursuit of Public Funding by Congregations*
Authors: Owens Michael Leo
Published: February 2006

Objective.To determine the effects of clergy attitudes on the willingness of congregations to seek public funding to provide social welfare.

Methods.Survey data are drawn from a probability sample of clergy leading congregations in metropolitan Atlanta, Georgia. A logistic regression model examines the effects of clergy attitudes on the potential pursuit of public funding by congregations.

Results.Controlling for a set of congregation attributes, a positive attitude toward partnerships between congregations and secular groups and a fear of government entanglement with religion are the strongest attitudinal predictors of congregation willingness to pursue public funding. However, attributes, particularly the racial composition of members and denominational affiliation, also predict congregation willingness to seek public funding.

Conclusions.Congregation willingness to pursue public funding is a function of clergy attitudes and congregation attributes, which has implications for politics and public policy.
Mexican Immigrant Self‐Employment Along the U.S.‐Mexico Border: An Analysis of 2000 Census Data*
Authors: Mora Marie T. , Dávila Alberto
Published: February 2006

Objective. This study explores the entrepreneurial tendencies of Mexican immigrants in metropolitan statistical areas (MSAs) on the U.S. side of the Mexican border vis‐à‐vis the U.S. interior.

Methods. Using 2000 Census data available in the 5% Integrated Public Use Microdata Series, we empirically analyze the self‐employment rates and earnings of Mexican immigrants residing in U.S. cities near Mexico versus those in nonborder MSAs.

Results. Our findings indicate that Mexican immigrants in MSAs along the U.S.‐Mexico border have significantly higher self‐employment rates (but lower earnings) than their counterparts in the rest of the United States and non‐Hispanic whites in border cities. Explanations for these findings include the existence of trade opportunities in U.S. border cities as well as intense labor market competition that crowds a greater share of immigrants into self‐employment.

Conclusion. Immigration reform that curtails the immigration flow from Mexico might hinder small business formation and economic development on the U.S. side of the Mexican border.
The Impact of Gentrification on Voter Turnout*
Authors: Gibbs Knotts H. , Haspel Moshe
Published: February 2006

Objective. The goal of this article is to test between two competing theories (mobilization vs. destabilization) about the impact of gentrification on political participation.

Methods. Using geographic information systems (GIS) software, Census data from 1990 and 2000, and a voter file for the City of Atlanta, we estimate a multilevel model of voter turnout.

Results. Controlling for relevant individual and contextual factors, we find that gentrification decreases turnout among longstanding residents.

Conclusions. Our findings provide support for the destabilization hypothesis and suggest that policymakers should develop strategies to soften the negative consequences of gentrification.
Globalization and the Digital Divide: The Roles of Structural Conduciveness and Global Connection in Internet Diffusion*
Authors: Crenshaw Edward M. , Robison Kristopher K.
Published: February 2006

Objectives. The goal of this research is to examine the role of modernization (i.e., structural conduciveness) in the form of income, telephone price and structure, education, and political structures, and global contact in the form of world cities, trade, investment, activities of international nongovernmental organizations, and short‐term exchanges of population in driving the worldwide diffusion of the Internet.

Methods. We use longitudinal regression analyses (1995–2000) of change in Internet hosts for approximately 80 developing countries.

Results. The analyses suggest that foreign investment, major urban agglomerations, manufacturing exports, nongovernmental organization presence, and tourism as well as democratic openness, property rights, and income predict Internet diffusion during the time period under investigation.

Conclusions. We conclude that indeed both conduciveness to Internet technology as well as globalization (contact) are important factors in the diffusion of the Internet.
Marginal zone lymphoma with a dual cutaneous and leukemic presentation and an aberrant myeloid‐monocytic phenotype
Authors: Keehn Connie A , Cualing Hernani
Published: February 2006

Abstract:  Marginal zone lymphoma (MZL) is an indolent neoplasm of mature B cells, classified by the World Health Organization into three categories: nodal, splenic, and extranodal MZL of mucosa‐associated lymphoid tissue (MALT lymphoma). We present an unusual case of MZL with cutaneous, leukemic, and bone marrow involvement at presentation and expression of an aberrant myeloid‐monocytic phenotype. This case is best classified as MZL of leukemic subtype.
Necrolytic migratory erythema
Authors: Kovács Réka K. , Korom Irma , Dobozy Attila , Farkas Gyula , Ormos Jenő , Kemény Lajos
Published: February 2006

Background:  Necrolytic migratory erythema is considered to be a paraneoplastic dermatosis. The classical symptoms are associated with α‐cell pancreatic islet cell tumor or ‘glucagonoma’. Generally, extracutaneous hallmarks of this disease include weight loss, diabetes, anaemia and diarrhoea.

Observation:  We report a case of a 39‐year‐old woman with a 3‐year history of recalcitrant psoriasiform eruption, who had no other associated symptoms on routine examination. Histologic examinations suggested necrolytic migratory erythema. Abdominal computer tomography was performed, which revealed a tumor in the tail of the pancreas. After distal resection of the pancreas her skin symptoms resolved in a few days time. Histology was consistent with glucagonoma. She is clinically well and symptomless and no signs of metastasis after 4 years.

Conclusions:  It is infrequent to have only necrolytic migratory erythema, hyperglucagonaemia and islet‐cell tumor but no other extracutaneous symptoms in glucagonoma syndrome. To our knowledge, ours is the second such case reported in the literature. Skin symptoms are important, often they are the clue to the diagnosis of glucagonoma syndrome.
Proliferative nodules with balloon‐cell change in a large congenital melanocytic nevus
Authors: McGowan Joseph W. , Smith Molly K. , Ryan Michael , Hood Antoinette F.
Published: February 2006

Abstract:  The balloon‐cell nevus was first described over 100 years ago. Since then, balloon‐cell changes of melanocytes have been noted in numerous tumors, including melanoma, blue nevus, and Spitz nevus. Whether these changes reflect cellular deterioration or proliferative changes is a matter of debate. We report a case in which balloon‐cell changes were found within proliferative nodules occurring in a large congenital melanocytic nevus.
Subclinical chronic lymphocytic leukaemia associated with a 13q deletion presenting initially in the skin: apropos of a case
Authors: Khandelwal Abha , Seilstad Kay H. , Magro Cynthia M.
Published: February 2006

Introduction:  B‐cell chronic lymphocytic leukaemia (B‐CLL) represents a low‐grade B‐cell lymphoproliferative disease that is the most common leukaemia in adults. The neoplastic cell is an autoreactive CD5 CD23 B lymphocyte. B‐CLL may involve the skin, typically in the context of known disease. We present a case of subclinical B‐CLL presenting initially in the skin.

Case Report:  A 73‐year‐old male developed a lesion on his right cheek in April 2003 compatible with basal cell carcinoma. The re‐excision specimen contained a well‐differentiated atypical lymphocytic infiltrate consistent with B‐CLL along with residual carcinoma. Subsequent laboratory studies revealed peripheral blood lymphocytosis with smudge cells. A diagnosis was made of Rai stage 0 CLL. Chromosomal studies on peripheral blood showed a deletion at 13q14.3. Excision of a second primary skin carcinoma revealed a squamous cell carcinoma in association with B‐CLL that was identical to his previously diagnosed skin involvement.

Conclusion:  This case identifies a cutaneous presentation of subclinical B‐CLL. There are two prior reports describing B‐CLL presenting initially in the skin. In one case, the infiltrates were incidental on a re‐excision specimen. The second report suggests 16% of B‐CLL patients have cutaneous manifestations as the first sign of disease.
CD44 and hyaluronate expression in follicular mucinosis
Authors: Kaya Gürkan , Augsburger Eric , Chavaz Pierre , Saurat Jean‐Hilaire
Published: February 2006

Background:  CD44 is a membrane glycoprotein and the major cell‐surface receptor of hyaluronate (HA). Lack of CD44 expression in mouse epidermis leads to an abnormal HA accumulation in the dermis, indicating an important role of CD44 in local HA metabolism. Decrease of epidermal CD44 expression in patients of lichen sclerosus et atrophicus is potentially responsible for dermal deposition of HA in this disease. Stromal HA accumulation is associated with decreased or lost expression of CD44 in perifollicular solitary cutaneous myxoma, myxoid dermatofibroma, and dermatofibrosarcoma protuberans.

Methods:  We examined the expression of CD44 and HA in the skin biopsy specimens of 10 patients with follicular mucinosis by using CD44‐specific antibodies and biotinylated HA‐binding protein (HABP), respectively.

Results:  No difference of CD44 expression was observed in the follicular keratinocytes when compared with those of unaffected interfollicular epidermis. The follicular zones of mucin deposition were strongly positive for HA. A weak interkeratinocyte staining for HA was also observed in the interfollicular epidermis. However, HABP staining revealed a stronger reactivity in the follicular keratinocytes surrounding the mucin‐accumulated areas compared to the interfollicular keratinocytes.

Conclusion:  Our results suggest an active secretion of HA by follicular cells in follicular mucinosis.
Expression profiles of melanogenesis‐related genes and proteins in acquired melanocytic nevus
Authors: Hashimoto Y. , Ito Y. , Kato T. , Motokawa T. , Katagiri T. , Itoh M.
Published: February 2006

We used three types of AMN to investigate the expression profiles of melanogenesis‐related genes [tyrosinase, tyrosinase‐related protein‐1 (TRP1), dopachrome tautomerase (TRP2), Pmel‐17/gp100, P‐protein, and microphthalmia‐associated transcription factor (MITF)], as well as tyrosinase, TRP1, Pmel‐17/gp100, and MITF proteins. Results: All melanogenesis‐related genes examined in the junctional type were expressed in the basal epidermal layer. In the compound and intradermal types, mRNA for tyrosinase, TRP2, and MITF was expressed in all of the AMN cells. However, the expression of TRP1, P‐protein, and Pmel‐17/gp100 in the compound type and TRP1 in the intradermal type became weaker in accordance with the depth of the dermis layer, as compared to those levels in the basal to upper dermis layer. Although tyrosinase and Pmel‐17/gp100 mRNA in the compound and intradermal types was expressed in the intraepidermal and dermal components, immunohistochemical staining showed that tyrosinase proteins were not detected in the lower dermis layer and Pmel‐17/gp100 proteins were not detected in the dermis. Conclusions: Our results suggest that all nevus cells that constitute AMN tissue originate from melanocytes. Further, there may be differences in the transcription levels of melanogenesis‐related genes as well as in their post‐transcriptional regulation between nevus cells located in the basal epidermal to upper dermis layer and those in the lower dermis layer.
Intravenous immunoglobulin inhibits anti‐glycoprotein IIb‐induced platelet apoptosis in a murine model of immune thrombocytopenia
Authors: Leytin Valery , Mykhaylov Sergiy , Starkey Alison F. , Allen David J. , Lau Herbert , Ni Heyu , Semple John W. , Lazarus Alan H. , Freedman John
Published: February 2006

We have previously shown that injection of anti‐glycoprotein (GP) IIb induces murine immune thrombocytopenia (ITP) and that intravenous immunoglobulin (IVIg) ameliorates ITP. We hypothesise that murine ITP may be associated with platelet apoptosis, which is upregulated by anti‐GPIIb and downregulated by IVIg. The current study demonstrated that anti‐GPIIb injection induced three critical apoptosis manifestations in platelets: (i) mitochondrial inner transmembrane potential (ΔΨm) depolarisation; (ii) caspase‐3 activation; and (iii) phosphatidylserine (PS) exposure. IVIg administration inhibited caspase‐3 activation and PS exposure, but not ΔΨm‐depolarisation, in anti‐GPIIb‐treated platelets, demonstrating that IVIg ameliorates thrombocytopenia concomitantly with inhibiting late, but not early mechanisms of platelet apoptosis.
Spectrum and significance of variants and mutations in the Fanconi anaemia group G gene in children with sporadic acute myeloid leukaemia
Authors: Meyer Stefan , Barber Lisa M. , White Daniel J. , Will Andrew M. , Birch Jillian M. , Kohler Janice A. , Ersfeld Klaus , Blom Eric , Joenje Hans , Eden Tim O. B. , Malcolm Taylor G.
Published: February 2006

Childhood acute myeloid leukaemia (AML) is uncommon. Children with Fanconi anaemia (FA), however, have a very high risk of developing AML. FA is a rare inherited disease caused by mutations in at least 12 genes, of which Fanconi anaemia group G gene (FANCG) is one of the commonest. To address to what extent FANCG variants contribute to sporadic childhood AML, we determined the spectrum of FANCG sequence variants in 107 children diagnosed with sporadic AML, using polymerase chain reaction (PCR), fluorescent single‐strand conformational polymorphism (SSCP) and sequencing methodologies. The significance of variants was determined by frequency analysis and assessment of evolutionary conservation. Seven children (6·5%) carried variants in FANCG. Two of these carried two variants, including the known IVS2 + 1G>A mutation with the novel missense mutation S588F, and R513Q with the intronic deletion IVS12‐38 (‐28)_del11, implying that these patients might have been undiagnosed FA patients. R513Q, which affects a semi‐conserved amino acid, was carried in two additional children with AML. Although not significant, the frequency of R513Q was higher in children with AML than unselected cord bloods. While FANCG mutation carrier status does not predispose to sporadic AML, the identification of unrecognised FA patients implies that FA presenting with primary AML in childhood is more common than suspected.
Hereditary pyrimidine 5′‐nucleotidase deficiency: from genetics to clinical manifestations
Authors: Zanella Alberto , Bianchi Paola , Fermo Elisa , Valentini Giovanna
Published: February 2006

Hereditary pyrimidine 5′‐nucleotidase (P5′N) deficiency is the most frequent abnormality of the red cell nucleotide metabolism causing hereditary non‐spherocytic haemolytic anaemia. The disorder is usually characterised by mild‐to‐moderate haemolytic anaemia associated with the accumulation of high concentrations of pyrimidine nucleotides within the erythrocyte. The precise mechanisms leading to the destruction of P5′N deficient red cells are still unclear. The pyrimidine 5′‐nucleotidase type‐I (P5′N‐1) gene is localised on 7p15‐p14 and the cDNA has been cloned and sequenced; 20 mutations have been identified so far in 30 unrelated families, most of them at the homozygous level. Recently, the comparison of recombinant mutants of human P5′N‐1 with the wild‐type enzyme has enabled the effects of amino acid replacements on the enzyme molecular properties to be determined and help to correlate genotype to clinical phenotype.
Delayed diagnosis and complications of Fanconi anaemia at advanced age – a paradigm
Authors: Huck Kirsten , Hanenberg Helmut , Gudowius Sonja , Fenk Roland , Kalb Reinhard , Neveling Kornelia , Betz Beate , Niederacher Dieter , Haas Rainer , Göbel Ulrich , Kobbe Guido , Schindler Detlev
Published: February 2006

Fanconi anaemia (FA) is a rare recessive DNA repair disorder clinically characterised by congenital malformations, progressive bone marrow failure and a high propensity for developing malignancies at an early age, predominantly acute myeloid leukaemia (AML) and squamous cell carcinoma. It is conceivable that a number of patients with hypomorphic mutations are not diagnosed as FA until severe complications in the treatment of a malignancy occur. Here, we report on a patient with FA‐A, diagnosed only at the age of 49 years due to persistent pancytopenia and myelodysplastic syndrome/AML induced by a first cycle of chemotherapy for bilateral metachronic breast cancer. This exceptional case clearly demonstrates that, in instances of long‐lasting mild pancytopenia or development of malignancies, especially at an unusually young age, FA should be ruled out, irrespective of the patient's age and features, especially before inflicting severe genotoxic stress.
An AAA protease FtsH can initiate proteolysis from internal sites of a model substrate, apo‐flavodoxin
Authors: Okuno Takashi , Yamanaka Kunitoshi , Ogura Teru
Published: February 2006

Escherichia coli FtsH, which belongs to the AAA (ATPases associated with diverse cellular activities) family, is an ATP‐dependent and membrane‐bound protease. FtsH degrades misassembled membrane proteins and a subset of cytoplasmic regulatory proteins. It has been proposed that ATP‐dependent proteases unfold substrate proteins and initiate a processive proteolysis from either terminus of the substrate polypeptide. We have found that FtsH degrades E. coli apo‐flavodoxin (apo‐Fld) but not holo‐Fld containing non‐covalently bound flavin mononucleotide (FMN). A mutant Fld carrying a substitution of Tyr94 to Asp (FldYD) with a lower affinity for FMN was efficiently degraded by FtsH. To elucidate the directionality of FldYD degradation by FtsH, we constructed several FldYD fusion proteins with glutathione S‐transferase (GST), green fluorescent protein (GFP), or both GST and GFP. It was found that FtsH was able to initiate degradation of the FldYD moiety even when it was sandwiched by GST and GFP. Evidence indicated that FtsH can initiate proteolysis of GST‐FldYD‐GFP from the FldYD moiety by translocating an internal loop to the protease chamber in an ATP‐dependent manner and that, at least, the proteolysis in the C to N direction proceeds processively.
Differential involvement of phosphatidylinositol 3‐kinase‐related protein kinases in hyperphosphorylation of replication protein A2 in response to replication‐mediated DNA double‐strand breaks
Authors: Sakasai Ryo , Shinohe Keitaro , Ichijima Yosuke , Okita Naoyuki , Shibata Atsushi , Asahina Kinji , Teraoka Hirobumi
Published: February 2006

Replication protein A2 (RPA2), a component of the RPA heterotrimer, is hyperphosphorylated and forms nuclear foci in response to camptothecin (CPT) that directly induces replication‐mediated DNA double‐strand breaks (DSBs). Ataxia‐telangiectasia mutated and Rad3‐related kinase (ATR) and DNA‐dependent protein kinase (DNA‐PK) are activated by CPT, and RPA2 is hyperphosphorylated in a DNA‐PK‐dependent manner. To distinguish the roles of phosphatidylinositol 3‐kinase‐related protein kinases including DNA‐PK, ataxia‐telangiectasia mutated (ATM), and ATR, in the response to replication‐mediated DSBs, we analyzed RPA2 focus formation and hyperphosphorylation during exposure to CPT. ATR knock‐down with siRNA suppressed CPT‐induced RPA2 hyperphosphorylation and focus formation. CPT‐induced RPA2 focus formation was normally observed in DNA‐PK‐ or ATM‐deficient cells. Comparison between CPT and hydroxyurea (HU) indirectly inducing DSBs showed that RPA2 hyperphosphorylation is DNA‐PK‐dependent in CPT‐treated cells and DNA‐PK‐independent in HU‐treated cells. Although RPA2 foci rapidly formed in response to HU and CPT, the RPA2 hyperphosphorylation in HU‐treated cells occurred later than in the CPT‐treated cells, indicating that the DNA‐PK dependency of RPA2 hyperphosphorylation is likely to be related to the mode of DSB induction. These results suggest that DNA‐PK is responsible for the RPA2 hyperphosphorylation following ATR‐dependent RPA2 focus formation in response to replication‐mediated DSBs directly induced by CPT.
Enhanced gene targeting efficiency by siRNA that silences the expression of the Bloom syndrome gene in human cells
Authors: So Sairei , Nomura Yuji , Adachi Noritaka , Kobayashi Yuki , Hori Tamaki , Kurihara Yasuyuki , Koyama Hideki
Published: February 2006

Gene targeting via homologous recombination is a powerful tool for studying gene function, but the targeting efficiency in human cell lines is too low for generating knockout mutants. Several cell lines null for the gene responsible for Bloom syndrome, BLM, have shown elevated targeting efficiencies. Therefore, we reasoned that gene targeting would be enhanced by transient suppression of BLM expression by RNA interference. To test this, we constructed a gene correction assay system to measure gene targeting frequencies using a disrupted hypoxanthine phosphoribosyltransferase (HPRT) locus in the human HT1080 cell line, and examined the effect of small interfering RNA (siRNA) for BLM on gene targeting. When HPRT‐null cells pretreated with BLM siRNA were co‐transfected with the siRNA and a gene correction vector, the gene targeting frequency was elevated three‐fold, while the random integration frequency was marginally affected. Remarkably, in BLM heterozygous (+/–) cells derived from HPRT‐null cells, the BLM siRNA treatment gave more than five‐fold higher targeting frequencies, even with one‐tenth the amount of BLM siRNA used for BLM+/+ cells. Furthermore, in the human pre‐B cell line Nalm‐6, the siRNA treatment enhanced gene targeting 6.3‐fold and > 5.8‐fold at the HPRT and adenine phosphoribosyltransferase (APRT) loci, respectively. These results indicate that transient suppression of BLM expression by siRNA stimulates gene targeting in human cells, facilitating a further improvement of gene targeting protocols for human cell lines.
Pulmonary involvement by Niemann–Pick disease. A report of six cases
Authors: Nicholson A G , Florio R , Hansell D M , du Bois R M , Wells A U , Hughes P , Ramadan H K , Mackinlay C I , Brambilla E , Ferretti G R , Erichsen A , Malone M , Lantuejoul S
Published: February 2006

Aims : Although pulmonary involvement is a known cause of morbidity in Niemann–Pick disease, histological features in the lung are not well characterized. The purpose of this study is to document the histological features seen in pulmonary involvement by types B and C Niemann–Pick disease and to correlate them with clinical and imaging data.

Methods and results : Surgical lung biopsies from six patients (four with type B and two with type C disease) were reviewed and all showed diffuse endogenous lipid pneumonia, with lesser involvement of the interstitium by fibrosis and foamy macrophage accumulation. In type B disease only, there was also fine cytoplasmic vacuolation within the cytoplasm of ciliated epithelial cells. Neither disease showed foamy changes within pneumocytes. One patient had a bronchial cast removed on whole lung lavage. Electron microscopy showed abnormal lamellar inclusions within lysosomes of affected cells in type B disease. In patients with type C disease, biopsies were undertaken as part of investigations into acute respiratory failure in the context of multiorgan systemic presentation. Three patients with type B disease had clinical disease limited to the lung, all adults (mean age of 40 years) with unexplained diffuse parenchymal lung disease and mainly ground‐glass shadowing on high‐resolution computed tomography.

Conclusions : Niemann–Pick disease should be considered for any patient with unexplained diffuse endogenous lipid pneumonia, even when disease is limited to the lungs and presentation is during adulthood.
The foetal Leydig cell – differentiation, function and regulation
Authors: O'Shaughnessy P. J. , Baker P. J. , Johnston H.
Published: February 2006

The foetal Leydig cell population arises shortly after testicular differentiation at around 12.5 dpc in the mouse and 6 weeks in the human. These cells function, primarily, to produce androgens which are essential for masculinization of the foetus. The origin of the foetal Leydig cells remains uncertain but it has been suggested that adrenocortical cells and foetal Leydig cells may share a common origin in an adreno‐genital primordium. Studies in the mouse are beginning to identify factors such as desert hedgehog and platelet‐derived growth factor which are required for foetal Leydig cell development. Regulation of foetal Leydig cell function remains uncertain in most species. Unlike the adult population of Leydig cells, the foetal Leydig cells in the mouse do not require luteinizing hormone (LH) to stimulate androgen production. An intact pituitary does appear to be required, however, and adrenocorticotrophic hormone (ACTH) will stimulate foetal Leydig cell function directly suggesting that both LH and ACTH act to maintain Leydig cell function in vivo. In the human LH/hCG is required for foetal Leydig cell function although the cells may also be sensitive to ACTH.
Disruption of reproductive development in male rat offspring following in utero exposure to phthalate esters
Authors: FOSTER PAUL M.D.
Published: February 2006

Certain Phthalate esters have been shown to produce reproductive toxicity in male rodents with an age dependent sensitivity in effects with foetal animals being more sensitive than neonates which are in turn more sensitive than pubertal and adult animals. While the testicular effects of phthalates in rats have been known for more than 30 years, recent attention has been focused on the ability of these agents to produce effects on reproductive development in male offspring after in utero exposure. These esters and in particular di‐butyl, di‐(2‐ethylhexyl) and butyl benzyl phthalates have been shown to produce a syndrome of reproductive abnormalities characterized by malformations of the epididymis, vas deferens, seminal vesicles, prostate, external genitalia (hypospadias), cryptorchidism and testicular injury together with permanent changes (feminization) in the retention of nipples/areolae (sexually dimorphic structures in rodents) and demasculinization of the growth of the perineum resulting in a reduced anogenital distance (AGD). Critical to the induction of these effects is a marked reduction in foetal testicular testosterone production at the critical window for the development of the reproductive tract normally under androgen control. A second Leydig cell product, insl3, is also significantly down regulated and is likely responsible for the cryptorchidism commonly seen in these phthalate‐treated animals. The testosterone decrease is mediated by changes in gene expression of a number of enzymes and transport proteins involved in normal testosterone biosynthesis and transport in the foetal Leydig cell. Alterations in the foetal seminiferous cords are also noted after in utero phthalate treatment with the induction of multinucleate gonocytes that contribute to lowered spermatocyte numbers in postnatal animals. The phthalate syndrome of effects on reproductive development has parallels with the reported human testicular dysgenesis syndrome, although no cause and effect relationship exists after exposure of humans to phthalate esters. However humans are exposed to and produce the critical phthalate metabolites that have been detected in blood of the general population, in children and also human amniotic fluid.
Is human fecundity declining?
Authors: Skakkebæk Niels E. , Jørgensen Niels , Main Katharina M. , Meyts Ewa Rajpert‐De , Leffers Henrik , Andersson Anna‐Maria , Juul Anders , Carlsen Elisabeth , Mortensen Gerda Krog , Jensen Tina Kold , Toppari Jorma
Published: February 2006

The decreasing trends in fertility rates in many industrialized countries are now so dramatic that they deserve much more scientific attention. Although social and behavioural factors undoubtedly play a major role for these trends, it seems premature, and not based on solid information, to conclude that these trends can be ascribed to social and behavioural changes alone. There is evidence to suspect that changing lifestyle and increasing environmental exposures, e.g. to endocrine disrupters, are behind the trends in occurrence of male reproductive health problems, including testis cancer, undescended testis and poor semen quality. These biological factors may also contribute to the extremely low fertility rates. However, the necessary research is complex and requires non‐traditional collaboration between demographers, epidemiologists, clinicians, biologists, wild life researchers, geneticists and molecular biologists. This research effort can hardly be carried out without major support from governments and granting agencies making it possible to fund collaborative projects within novel research networks of scientists.
Mouse models for genes involved in impaired spermatogenesis
Authors: O'Bryan M. K. , de Kretser D.
Published: February 2006

Since the introduction of molecular biology and gene ablation technologies there have been substantial advances in our understanding of how sperm are made and fertilization occurs. There have been at least 150 different models of specifically altered gene function produced that have resulted in male infertility spanning virtually all aspects of the spermatogenic, sperm maturation and fertilization processes. While each has, or potentially will reveal, novel aspects of these processes, there is still much of which we have little knowledge. The current review is by no means a comprehensive list of these mouse models, rather it gives an overview of the potential for such models which up to this point have generally been ‘knockouts’; it presents alternative strategies for the production of new models and emphasizes the importance of thorough phenotypic analysis in order to extract a maximum amount of information from each model.
Neuroendocrine mechanisms controlling female puberty: new approaches, new concepts
Authors: Ojeda Sergio R. , Roth Christian , Mungenast Alison , Heger Sabine , Mastronardi Claudio , Parent Anne‐Simone , Lomniczi Alejandro , Jung Heike
Published: February 2006

Sexual development and mature reproductive function are controlled by a handful of neurones that, located in the basal forebrain, produce the decapeptide luteinizing hormone releasing hormone (LHRH). LHRH is released into the portal system that connects the hypothalamus to the pituitary gland and act on the latter to stimulate the synthesis and release of gonadotrophin hormones. The pubertal activation of LHRH release requires coordinated changes in excitatory and inhibitory inputs to LHRH‐secreting neurones. These inputs are provided by both transsynaptic and glia‐to‐neurone communication pathways. Using cellular and molecular approaches, in combination with transgenic animal models and high‐throughput procedures for gene discovery, we are gaining new insight into the basic mechanisms underlying this dual control of LHRH secretion and, hence, the initiation of mammalian puberty. Our results suggest that the initiation of puberty requires reciprocal neurone‐glia communication involving excitatory amino acids and growth factors, and the coordinated actions of a group of transcriptional regulators that appear to represent a higher level of control governing the pubertal process.
Sperm function tests and fertility
Authors: Aitken R. J.
Published: February 2006

Traditionally, the diagnosis of male infertility has depended upon a descriptive evaluation of human semen with emphasis on the number of spermatozoa that are present in the ejaculate, their motility and their morphology. The fundamental tenet underlying this approach is that male fertility can be defined by reference to a threshold concentration of motile, morphologically normal spermatozoa that must be exceeded in order to achieve conception. Many independent studies have demonstrated that this fundamental concept is flawed and, in reality, it is not so much the absolute number of spermatozoa that determines fertility, but their functional competence. In the light of this conclusion, a range of in vitro tests have been developed to monitor various aspects of sperm function including their potential for movement, cervical mucus penetration, capacitation, zona recognition, the acrosome reaction and sperm–oocyte fusion. Such functional assays have been found to predict the fertilizing capacity of human spermatozoa in vitro and in vivo with some accuracy. Recent developments in this field include the introduction of tests to assess the degree to which human spermatozoa have suffered oxidative stress as well as the integrity of their nuclear and mitochondrial DNA. Such assessments not only yield information on the fertilizing capacity of human spermatozoa but also their ability to support normal embryonic development.
Trends in European fertility: should Europe try to increase its fertility rate…or just manage the consequences?1
Authors: Grant Jonathan , Hoorens Stijn , Sivadasan Suja , Loo Mirjam Van Het , Davanzo Julie , Hale Lauren , Butz William
Published: February 2006

Currently across Europe, birth rates are falling and the population is aging. This paper describes these trends and assesses which policies can prevent or mitigate the adverse consequences of these two trends.
Fertility rates and future population trends: will Europe's birth rate recover or continue to decline?
Authors: Lutz Wolfgang
Published: February 2006

Europe has long completed its demographic transition from high birth and death rates to low birth and death rates. But the demographic transition paradigm that has been very useful for explaining global demographic trends during the 20th century and that still has strong predictive power when it comes to projecting future trends in countries that still have high fertility, has nothing to say about the future of fertility in Europe. The currently popular notion of a ‘second demographic transition’ is a useful way to describe a bundle of behavioural and normative changes that recently happened in Europe, but it has no predictive power. The social sciences have not yet come up with a useful theory to predict the future fertility level of post‐demographic transition societies. We even do not know whether the trend will be up or down. Given the lack of a predictive theory, this paper will try to do two things: (i) Summarize different substantive arguments that would either suggest the assumption of a recovery of fertility rates in Europe or alternatively, imply further declines. (ii) Convert this discussion of the uncertainty of future fertility trends into probabilistic population projections for Europe, thus highlighting the implications of alternative fertility levels over the coming years. We will also discuss trade‐offs between fertility and immigration, and the phenomenon that Europe now has entered a period of negative momentum of population growth.
Possible impact of phthalates on infant reproductive health
Authors: Lottrup G. , Andersson A.‐M. , Leffers H. , Mortensen G. K. , Toppari J. , Skakkebæk N. E. , Main K. M.
Published: February 2006

Phthalates adversely affect the male reproductive system in animals, inducing hypospadias, cryptorchidism, reduced testosterone production and decreased sperm counts. Phthalate effects are much more severe after in utero than adult exposure. Little is known about human health effects. This study discusses two recent studies on perinatal phthalate exposure, which indicated that human testicular development might be susceptible to phthalates. One study analysed phthalate monoesters in breast milk and reproductive hormone levels in infants. Five of six phthalates [monoethyl‐(MEP), monobutyl‐ (MBP), monomethyl‐ (MMP), mono‐2‐ethylhexyl‐ (MEHP) and mono‐isononyl phthalate (MiNP)] showed correlation with hormone levels in healthy boys, which were indicative of lower androgen activity and reduced Leydig cell function. MEP and MBP were positively correlated with serum sex hormone‐binding globulin (SHBG) levels. MMP, MEP, MBP, MEHP and MiNP were positively correlated with the LH/testosterone ratio. Another study found a reduction of the anogenital index (AGI) in infant boys with increasing levels of MBP, MEP, monobenzyl‐ and mono‐isobutyl phthalate in maternal urine samples during late‐pregnancy. Boys with small AGI showed a high prevalence of cryptorchidism and small genital size. Taken together these studies suggest an antivirilizing effect of phthalates in infants. Most of these findings are in line with animal observations. However, the possible effects of MEP appear to be limited to humans. This may be due to differences in exposure routes (inhalation and dermal absorption which circumvents liver detoxification in addition to oral) and metabolism, or this association could be spurious. As phthalates are produced as bulk chemicals worldwide, these new findings raise concern about the safety of phthalate exposure for pregnant women and infants.