bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemoprevention with Protein Kinase A RIα Antisense in DMBA‐Mammary Carcinogenesis
Authors: NESTEROVA MARIA V. , CHO‐CHUNG YOON S.
Published: January 2006

Cancer is potentially preventable disease. A surprising variety of intracellular pathways can be a target for chemoprevention. Earlier it was discovered that cAMP‐mediated system can play important role in prevention of DMBA‐mammary carcinogenesis. There are two types of cAMP‐dependent protein kinases (PKA), type I (PKA‐I) and type II (PKA‐II), which share a common catalytic (C) subunits, but contain distinct regulatory (R) ones, RI versus RII, respectively. Evidence suggests that increased expression of PKA‐I and its regulatory subunit (RIα) correlates with tumorogenesis and tumor growth. It was found that downregulation of RIα by 21‐mer antisense oligonucleotide led to growth arrest of cancer cells. The effect of RIα antisense oligonucleotide correlated with a decrease in RIα protein and a concomitant increase in RIIβ protein level. It was shown that antisense RIα can protect in a sequence‐specific manner from 7,12‐dimethylbenz(a)anthracene (DMBA)‐induced mammary carcinogenesis. At 90 days after DMBA intubation, RIα‐antisense‐treated rats exhibited significantly lower number of tumors per rat, than untreated control animals. The antisense also delayed the first tumor appearance. An increase in RIα and PKA‐I levels in the mammary gland and liver preceded tumor production, and antisense downregulation of RIα restored normal levels of PKA‐I and PKA‐II in these tissues. Antisense RIα in the liver induced the phase II enzymes, glutathione S‐transferase and quinone oxidoreductase, c‐fos protein, and activator protein‐1 (AP‐1)‐ and cAMP response element (CRE)‐directed transcription. In the mammary gland, antisense RIα promoted DNA repair processes. In contrast, the CRE transcription‐factor decoy could not mimic these effects of antisense RIα. The results demonstrate that RIα antisense produces dual anticarcinogenic effects: (a) increasing DMBA detoxification in the liver by increasing phase II enzyme activities, increasing CRE‐binding‐protein phosphorylation and enhancing CRE‐ and AP‐1 directed transcription; and (b) activating DNA repair processes in the mammary gland by downregulating of PKA‐1.
Antibody Immunity to the p53 Oncogenic Protein Is a Prognostic Indicator in Ovarian Cancer
Authors: Goodell Vivian , Salazar Lupe G. , Urban Nicole , Drescher Charles W. , Gray Heidi , Swensen Ron E. , McIntosh Martin W. , Disis Mary L.
Published: January 2006

Purpose

Presence of intratumoral T-cell infiltration has been linked to improved survival in ovarian cancer patients. We questioned whether antibody immunity specific for ovarian cancer tumor antigens would predict disease outcome. We evaluated humoral immune responses against ovarian cancer antigens p53, HER-2/neu, and topoisomerase IIα.

Patients and Methods

Serum was collected from 104 women (median age, 59 years; range, 34 to 89 years) at the time of their initial definitive surgery for ovarian cancer. Serum was analyzed by enzyme-linked immunosorbent assay for antibodies to p53, HER-2/neu, and topoisomerase IIα proteins. Antibody immunity to tetanus toxoid was assessed as a control. The incidence of humoral immunity at the time of diagnosis to any of these three antigens was tabulated. For patients with advanced-stage disease (III/IV), correlation was made between the presence of tumor-specific immunity at the time of diagnosis and overall survival. Patients were followed for a median of 1.8 years.

Results

Multivariate analysis showed the presence of p53 antibodies to be an independent variable for prediction of overall survival in advanced-stage patients. Overall survival was significantly higher for patients with antibodies to p53 when compared with patients without p53 antibodies (P = .01). The median survival for p53 antibody-positive patients was 51 months (95% CI, 23.5 to 60.5 months) compared with 24 months (95% CI, 19.4 to 28.6 months) for patients without antibodies to p53.

Conclusion

Data presented here demonstrate that advanced stage ovarian cancer patients can have detectable tumor-specific antibody immunity and that immunity to p53 may predict improved overall survival in patients with advanced-stage disease.
Antiangiogenic and Antitumor Effects of Bevacizumab in Patients With Inflammatory and Locally Advanced Breast Cancer
Authors: Wedam Suparna Bonthala , Low Jennifer A. , Yang Sherry X. , Chow Catherine K. , Choyke Peter , Danforth David , Hewitt Stephen M. , Berman Arlene , Steinberg Seth M. , Liewehr David J. , Plehn Jonathan , Doshi Arpi , Thomasson Dave , McCarthy Nicole , Koeppen Hartmut , Sherman Mark , Zujewski JoAnne , Camphausen Kevin , Chen Helen , Swain Sandra M.
Published: January 2006

Purpose

Vascular endothelial growth factor (VEGF) is a potent molecule that mediates tumor angiogenesis primarily through VEGF receptor 2 (VEGFR2). Bevacizumab, a recombinant humanized monoclonal antibody to VEGF, was administered to previously untreated patients to evaluate parameters of angiogenesis.

Patients and Methods

Twenty-one patients with inflammatory and locally advanced breast cancer were treated with bevacizumab for cycle 1 (15 mg/kg on day 1) followed by six cycles of bevacizumab with doxorubicin (50 mg/m2) and docetaxel (75 mg/m2) every 3 weeks. After locoregional therapy, patients received eight cycles of bevacizumab alone, and hormonal therapy when indicated. Tumor biopsies and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were obtained at baseline, and after cycles 1, 4, and 7.

Results

A median decrease of 66.7% in phosphorylated VEGFR2 (Y951) in tumor cells (P = .004) and median increase of 128.9% in tumor apoptosis (P = .0008) were seen after bevacizumab alone. These changes persisted with the addition of chemotherapy. There were no significant changes in microvessel density or VEGF-A expression. On DCE-MRI, parameters reflecting reduced angiogenesis, a median decrease of 34.4% in the inflow transfer rate constant (P = .003), 15.0% in the backflow extravascular- extracellular rate constant (P = .0007) and 14.3% in extravascular-extracellular volume fraction (P = .002) were seen after bevacizumab alone.

Conclusion

Bevacizumab has inhibitory effects on VEGF receptor activation and vascular permeability, and induces apoptosis in tumor cells.
Subtype and Prognostic Classification of Rhabdomyosarcoma by Immunohistochemistry
Authors: Wachtel Marco , Runge Tina , Leuschner Ivo , Stegmaier Sabine , Koscielniak Ewa , Treuner Jörn , Odermatt Bernhard , Behnke Silvia , Niggli Felix K. , Schäfer Beat W.
Published: January 2006

Purpose

Rhabdomyosarcoma (RMS) is classified into two main subgroups: the embryonal (ERMS) and the alveolar (ARMS) form. The majority of the ARMSs are associated with specific chromosomal translocations (pARMS). Because ARMS is much more aggressive than ERMS, RMS subclassification has clinical relevance. However, diagnosis of RMS subgroups on the basis of histology or molecular biology can be difficult, and supplementing diagnostic methods would be desirable. The aim of this study was to establish a panel of markers for RMS subgroup classification by immunohistochemistry.

Materials and Methods

Gene expression data were used for selection of subgroup-specific markers. Single sections of RMS with available expression data were used for establishment of the immunohistochemistry. Evaluation of the sensitivity and specificity of the markers was carried out using a tissue array representing 252 RMSs. Kaplan-Meier survival curves were calculated for determination of differences in overall survival of the different staining subgroups.

Results

AP2β and P-cadherin were selected as markers for pARMS, and epidermal growth factor receptor (EGFR) and fibrillin-2 as markers for ERMS. EGFR + fibrillin-2 detected ERMS with a specificity of 90% and with a sensitivity of 60%. AP2β + P-cadherin detected pARMS with a specificity of 98% and a sensitivity of 64%, and allowed the detection of several misclassified tumors. The EGFR + fibrillin-2–positive group is associated with a favorable outcome, and the AP2β + P-cadherin–positive group is associated with an unfavorable outcome.

Conclusion

The presented set of marker proteins detects RMS subgroups with high specificity and may be useful in routine subtype classification of RMS.
Serum YKL-40 Predicts Relapse-Free and Overall Survival in Patients With American Joint Committee on Cancer Stage I and II Melanoma
Authors: Schmidt Henrik , Johansen Julia S. , Sjoegren Pia , Christensen Ib J. , Sorensen Boe S. , Fode Kirsten , Larsen Jorn , von der Maase Hans
Published: January 2006

Purpose

To evaluate the novel tumor biomarker YKL-40 in serial serum samples from patients with American Joint Committee on Cancer (AJCC) stage I and II melanoma from the time of diagnosis and during routine follow-up. Macrophages, neutrophils, and cancer cells secrete YKL-40, and a high serum level has been associated with poor prognosis in patients with several cancer types.

Patients and Methods

Serum samples from 234 patients with stage I (n = 162) and II (n = 72) melanoma were analyzed for YKL-40 by enzyme-linked immunosorbent assay. Serial samples were obtained before definitive primary surgery and during follow-up.

Results

After a median follow-up period of 66 months (range, 1 to 97 months), 41 relapses (18%) and 39 deaths (17%) were observed. Serum YKL-40 treated as an updated continuous covariate were analyzed together with the covariates sex, age, primary tumor site, ulceration, thickness, Clark level and histologic subtype in a Cox proportional hazard model. Serum YKL-40 was an independent prognostic factor of relapse-free survival (hazard ratio [HR], 1.6; 95% CI, 1.1 to 2.5; P = .03) and overall survival (HR, 1.8; 95% CI, 1.2 to 2.6; P = .002) together with thickness and ulceration. The serum level of YKL-40 (dichotomized as normal or elevated) at the time of diagnosis was also an independent prognostic factor for overall survival (HR, 3.6, 95% CI, 1.7 to 7.7; P = .001).

Conclusion

Serum YKL-40 may be an early biomarker of relapse and survival in patients with AJCC stage I and II melanoma. Serum YKL-40 may also be useful for patient stratification and follow-up in clinical trials. Our results need confirmation in an independent study.
Activity of Cdc2 and its interaction with the cyclin Cdc13 depend on the molecular chaperone Cdc37 inSchizosaccharomyces pombe
Authors: Turnbull Emma L. , Martin Ina V. , Fantes Peter A.
Published: January 2006

Cdc37 is a molecular chaperone whose clients are predominantly protein kinases, many of which are important in cell-cycle progression. Temperature-sensitive mutants of cdc37 in Schizosaccharomyces pombe are lethal at the restrictive temperature, arresting cell division within a single cell cycle. These mutant cells elongate during incubation at the restrictive temperature, consistent with a cell-cycle defect. The cell-cycle arrest arises from defective function of the mutant Cdc37 proteins rather than a reduction in Cdc37 protein levels. Around 80% of the arrested, elongated cells contain a single nucleus and replicated (2C) DNA content, indicating that these mutants arrest the cell cycle in G2 or mitosis (M). Cytological observations show that the majority of cells arrest in G2. In fission yeast, a G2 cell-cycle arrest can arise by inactivation of the cyclin-dependent kinase (Cdk) Cdc2 that regulates entry into mitosis. Studies of the cdc37 temperature-sensitive mutants show a genetic interaction with some cdc2 alleles and overexpression of cdc2 rescues the lethality of some cdc37 alleles at the restrictive temperature, suggesting that Cdc2 is a likely client for the Cdc37 molecular chaperone. In cdc37 temperature-sensitive mutants at the restrictive temperature, the level of Cdc2 protein remains constant but Cdc2 protein kinase activity is greatly reduced. Inactivation of Cdc2 appears to result from the inability to form complexes with its mitotic cyclin partner Cdc13. Further evidence for Cdc2 being a client of Cdc37 in S. pombe comes from the identification of genetic and biochemical interactions between these proteins.
CD24 affects CXCR4 function in pre-B lymphocytes and breast carcinoma cells
Authors: Schabath Heidi , Runz Steffen , Joumaa Safwan , Altevogt Peter
Published: January 2006

CD24 is a small, heavily glycosylated cell-surface protein which is linked to the membrane via a glycosyl-phosphatidylinositol (GPI-) anchor and therefore localizes in lipid rafts. CD24 is widely used as a cell-lineage marker for hematopoietic cells. CD24 is also expressed on a variety of human carcinomas, including epithelial ovarian, breast, prostate, colon and lung cancer and has been linked to poor prognosis. Except for its role as a ligand for P-selectin on carcinoma and myeloid cells, a specific function for CD24 has not been determined. Here we show that CD24 affects the function of the chemokine receptor CXCR4. Using isolated CD19-positive bone marrow B cells from CD24-knockout mice and CD24–/– pre-B lymphocytic cell lines, we demonstrate that CD24 expression reduces SDF-1-mediated cell migration and signalling via CXCR4. We observed that the loss of CD24 augmented cellular cholesterol levels and enhanced CXCR4 lipid raft association. Altered chemotactic migration and raft residence was also observed in MDA-MB-231 breast cancer cells expressing high and low levels of CD24 and CXCR4 receptor. MDA-MB-231 cells expressing low levels of CD24 also showed enhanced tumour formation in NOD/SCID mice compared with cells overexpressing CD24. These results demonstrate a novel role for CD24 as a regulator of CXCR4 function that could be relevant for breast cancer growth and metastasis.
Unifying constructal theory for scale effects in running, swimming and flying
Authors: Bejan Adrian , Marden James H.
Published: January 2006

Biologists have treated the view that fundamental differences exist between running, flying and swimming as evident, because the forms of locomotion and the animals are so different: limbs and wings vs body undulations,neutrally buoyant vs weighted bodies, etc. Here we show that all forms of locomotion can be described by a single physics theory. The theory is an invocation of the principle that flow systems evolve in such a way that they destroy minimum useful energy (exergy, food). This optimization approach delivers in surprisingly direct fashion the observed relations between speed and body mass (Mb) raised to 1/6, and between frequency(stride, flapping) and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(M_{\mathrm{b}}^{-1{/}6}\) \end{document}, and shows why these relations hold for running, flying and swimming. Animal locomotion is an optimized two-step intermittency: an optimal balance is achieved between the vertical loss of useful energy (lifting the body weight,which later drops), and the horizontal loss caused by friction against the surrounding medium. The theory predicts additional features of animal design:the Strouhal number constant, which holds for running as well as flying and swimming, the proportionality between force output and mass in animal motors,and the fact that undulating swimming and flapping flight occur only if the body Reynolds number exceeds approximately 30. This theory, and the general body of work known as constructal theory, together now show that animal movement (running, flying, swimming) and fluid eddy movement (turbulent structure) are both forms of optimized intermittent movement.
Diel `tuning' of coral metabolism: physiological responses to light cues
Authors: Levy O. , Achituv Y. , Yacobi Y. Z. , Dubinsky Z. , Stambler N.
Published: January 2006

Hermatypic-zooxanthellate corals track the diel patterns of the main environmental parameters - temperature, UV and visible light - by acclimation processes that include biochemical responses. The diel course of solar radiation is followed by photosynthesis rates and thereby elicits simultaneous changes in tissue oxygen tension due to the shift in photosynthesis/respiration balance. The recurrent patterns of sunlight are reflected in fluorescence yields, photosynthetic pigment content and activity of the two protective enzymes superoxide dismutase (SOD) and catalase (CAT),enzymes that are among the universal defenses against free radical damage in living tissue. All of these were investigated in three scleractinian corals: Favia favus, Plerogyra sinuosa and Goniopora lobata. The activity of SOD and CAT in the animal host followed the course of solar radiation, increased with the rates of photosynthetic oxygen production and was correlated with a decrease in the maximum quantum yield of photochemistry in Photosystem II (PSII)(ΔF′/Fm′). SOD and CAT activity in the symbiotic algae also exhibited a light intensity correlated pattern,albeit a less pronounced one. The observed rise of the free-radical-scavenger enzymes, with a time scale of minutes to several hours, is an important protective mechanism for the existence and remarkable success of the unique cnidarian-dinoflagellate associations, in which photosynthetic oxygen production takes place within animal cells. This represents a facet of the precarious act of balancing the photosynthetic production of oxygen by the algal symbionts with their destructive action on all living cells, especially those of the animal host.
The effect of elevated hydrostatic pressure on the spectral absorption of deep-sea fish visual pigments
Authors: Partridge J. C. , White E. M. , Douglas R. H.
Published: January 2006

The effect of hydrostatic pressure (0.1-54 MPa, equivalent to pressures experienced by fish from the ocean's surface to depths of ca. 5400 m) on visual pigment absorption spectra was investigated for rod visual pigments extracted from the retinae of 12 species of deep-sea fish of diverse phylogeny and habitat. The wavelength of peak absorption (λmax) was shifted to longer wavelengths by an average of 1.35 nm at 40 MPa (a pressure approximately equivalent to average ocean depth) relative to measurements made at one atmosphere (ca. 0.1 MPa), but with little evidence of a change in absorbance at the λmax. We conclude that previousλ max measurements of deep-sea fish visual pigments, made at a pressure close to 0.1 MPa, provide a good indication ofλ max values at higher pressures when considering the ecology of vision in the deep-sea. Although not affecting the spectral sensitivity of the animal to any important degree, the observed shift inλ max may be of interest in the context of understanding opsin-chromophore interaction and spectral tuning of visual pigments.
Middle ear dynamics in response to seismic stimuli in the Cape golden mole (Chrysochloris asiatica)
Authors: Willi U. B. , Bronner G. N. , Narins P. M.
Published: January 2006

The hypertrophied malleus in the middle ear of some golden moles has been assumed to be an adaptation for sensing substrate vibrations by inertial bone conduction, but this has never been conclusively demonstrated. The Cape golden mole (Chrysochloris asiatica) exhibits this anatomical specialization, and the dynamic properties of its middle ear response to vibrations were the subjects of this study.

Detailed three-dimensional middle ear anatomy was obtained by x-ray microcomputed tomography (μCT) at a resolution of 12 μm. The ossicular chain exhibits large malleus mass, selective reduction of stiffness and displacement of the center of mass from the suspension points, all favoring low-frequency tuning of the middle ear response. Orientation of the stapes relative to the ossicular chain and the structure of the stapes footplate enable transmission of substrate vibrations arriving from multiple directions to the inner ear.

With the long axes of the mallei aligned parallel to the surface, the animal's head was stimulated by a vibration exciter in the vertical and lateral directions over a frequency range from 10 to 600 Hz. The ossicular chain was shown to respond to both vertical and lateral vibrations. Resonant frequencies were found between 71 and 200 Hz and did not differ significantly between the two stimulation directions. Below resonance, the ossicular chain moves in phase with the skull. Near resonance and above, the malleus moves at a significantly larger mean amplitude (5.8±2.8 dB) in response to lateral vs vertical stimuli and is 180° out of phase with the skull in both cases.

A concise summary of the propagation characteristics of both seismic body(P-waves) and surface (R-waves) is provided. Potential mechanisms by which the animal might exploit the differential response of the ossicular chain to vertical and lateral excitation are discussed in relation to the properties of surface seismic waves.
Drosophila melanogasterlocomotion in cold thin air
Authors: Dillon Michael E. , Frazier Melanie R.
Published: January 2006

The alpine environment is likely to challenge insect locomotion because of low mean temperatures and reduced barometric pressure. In this study, we measured the direct and interactive effects of these factors on walking and flight performance of wild-caught Drosophila melanogaster Meigen. We found that decreased temperature and decreased air pressure both reduced walking speed and flight performance. Flies walked more slowly at 18°C and in the lowest air pressure treatment (34 kPa). This treatment, equivalent in air pressure to the top of Mount Everest, was the only air pressure that significantly reduced fly walking speed. Therefore, walking performance in the wild is likely limited by temperature, but not oxygen availability. In contrast to walking performance, low but ecologically realistic air pressures dramatically reduced overall flight performance. The effects of reduced air pressure on flight performance were more pronounced at colder temperatures. Reduced flight performance in high altitude conditions was primarily driven by an increased reluctance for flies to initiate flight rather than outright failure to fly. Such reluctance to fly in high altitude conditions may in part explain the prevalence of aptery and brachyptery in high altitude insects. The observed interactive effects of temperature and air pressure on flight performance confirm the importance of simultaneously manipulating both of these factors when studying the impact of altitudinal conditions on insect physiology and behavior.
Water relations of tetrapod integument
Authors: Lillywhite Harvey B.
Published: January 2006

The vertebrate integument represents an evolutionary compromise between the needs for mechanical protection and those of sensing the environment and regulating the exchange of materials and energy. Fibrous keratins evolved as a means of strengthening the integument while simultaneously providing a structural support for lipids, which comprise the principal barrier to cutaneous water efflux in terrestrial taxa. Whereas lipids are of fundamental importance to water barriers, the efficacy of these barriers depends in many cases on structural features that enhance or maintain the integrity of function. Amphibians are exceptional among tetrapods in having very little keratin and a thin stratum corneum. Thus, effective lipid barriers that are present in some specialized anurans living in xeric habitats are external to the epidermis, whereas lipid barriers of amniotes exist as a lipid-keratin complex within the stratum corneum. Amphibians prevent desiccation of the epidermis and underlying tissues either by evaporating water from a superficial aqueous film, which must be replenished, or by shielding the stratum corneum with superficial lipids. Water barrier function in vertebrates generally appears to be relatively fixed, although various species have`plasticity' to adjust the barrier effectiveness facultatively. While it is clear that both phenotypic plasticity and genetic adaptation can account for covariation between environment and skin resistance to water efflux, studies of the relative importance of these two phenomena are few. Fundamental mechanisms for adjusting the skin water barrier include changes in barrier thickness, composition and physicochemical properties of cutaneous lipids,and/or geometry of the barrier within the epidermis. While cutaneous lipids have been studied extensively in the contexts of disease and cosmetics,relatively little is known about the processes of permeability barrier ontogenesis related to adaptation and environment. Advances in such knowledge have didactic significance for understanding vertebrate evolution as well as practical application to clinical dermatology.
The influence of anaesthesia on the tensile properties of spider silk
Authors: Pérez-Rigueiro J. , Elices M. , Plaza G. R. , Real J. I. , Guinea G. V.
Published: January 2006

In this study of the effect of anaesthesia on both the forced silking process and on the properties of the retrieved silk fibres, a monitored forced silking process enables the silking force to be measured during the whole process. Silk samples were tensile-tested and their diameters measured. Force-displacement curves and stress-strain curves were drawn. The evolution of the silking process of anaesthetized spiders is found to be complex, but it sheds light on the details of the spinning mechanism of spider silk.
Variation in the innate and acquired arms of the immune system among five shorebird species
Authors: Mendes Luisa , Piersma Theunis , Hasselquist Dennis , Matson Kevin D. , Ricklefs Robert E.
Published: January 2006

To contribute to an understanding of the evolutionary processes that shape variation in immune responses, we compared several components of the innate and acquired arms of the immune system in five related, but ecologically diverse, migratory shorebirds (ruff Philomachus pugnax L., ruddy turnstone Arenaria interpres L., bar-tailed godwit Limosa lapponica L., sanderling Calidris alba Pallas and red knot C. canutus L.). We used a hemolysis-hemagglutination assay in free-living shorebirds to assess two of the innate components (natural antibodies and complement-mediated lysis), and a modified quantitative enzyme-linked immunosorbent assay in birds held in captivity to assess the acquired component (humoral antibodies against tetanus and diphtheria toxoid)of immunity. Ruddy turnstones showed the highest levels of both innate and acquired immune responses. We suggest that turnstones could have evolved strong immune responses because they scavenge among rotting organic material on the seashore, where they might be exposed to a particularly broad range of pathogens. Although ruffs stand out among shorebirds in having a high prevalence of avian malaria, they do not exhibit higher immune response levels. Our results indicate that relationships between immune response and infection are not likely to follow a broad general pattern, but instead depend on type of parasite exposure, among other factors.
Detection of Biological Threat Agents by Real-Time PCR: Comparison of Assay Performance on the R.A.P.I.D., the LightCycler, and the Smart Cycler Platforms
Authors: Christensen Deanna R , Hartman Laurie J , Loveless Bonnie M , Frye Melissa S , Shipley Michelle A , Bridge Deanna L , Richards Michelle J , Kaplan Rebecca S , Garrison Jeffrey , Baldwin Carson D , Kulesh David A , Norwood David A
Published: January 2006

Background: Rapid detection of biological threat agents is critical for timely therapeutic administration. Fluorogenic PCR provides a rapid, sensitive, and specific tool for molecular identification of these agents. We compared the performance of assays for 7 biological threat agents on the Idaho Technology, Inc. R.A.P.I.D.®, the Roche LightCycler®, and the Cepheid Smart Cycler®.

Methods: Real-time PCR primers and dual-labeled fluorogenic probes were designed to detect Bacillus anthracis, Brucella species, Clostridium botulinum, Coxiella burnetii, Francisella tularensis, Staphylococcus aureus, and Yersinia pestis. DNA amplification assays were optimized by use of Idaho Technology buffers and deoxynucleotide triphosphates supplemented with Invitrogen Platinum® Taq DNA polymerase, and were subsequently tested for sensitivity and specificity on the R.A.P.I.D., the LightCycler, and the Smart Cycler.

Results: Limit of detection experiments indicated that assay performance was comparable among the platforms tested. Exclusivity and inclusivity testing with a general bacterial nucleic acid cross-reactivity panel containing 60 DNAs and agent-specific panels containing nearest neighbors for the organisms of interest indicated that all assays were specific for their intended targets.

Conclusion: With minor supplementation, such as the addition of Smart Cycler Additive Reagent to the Idaho Technology buffers, assays for DNA templates from biological threat agents demonstrated similar performance, sensitivity, and specificity on all 3 platforms.
Effects of Folic Acid Before and After Vitamin B12 on Plasma Homocysteine Concentrations in Hemodialysis Patients with Known MTHFR Genotypes
Authors: Pastore Anna , De Angelis Sandro , Casciani Stefania , Ruggia Rosalba , Di Giovamberardino Gianna , Noce Annalisa , Splendiani Giorgio , Cortese Claudio , Federici Giorgio , Dessı' Mariarita
Published: January 2006

Background: Treatment with folic acid and vitamin B12 appears to be effective in lowering total plasma homocysteine (tHcy) concentrations, but whether vitamin B12 alone lowers tHcy in patients with normal vitamin B12 status is unknown. The aims of the present study were to explore the effect of individual supplementation with folic acid or vitamin B12 on tHcy concentrations in hemodialysis (HD) patients and to compare changes in tHcy concentrations with MTHFR genotype.

Methods: We recruited 200 HD patients (119 men) from the “Umberto I” Hospital (Frosinone, Italy) and the Dialysis Unit of University Hospital “Tor Vergata”. These patients were randomized blindly into 2 groups of 100 each. Unfortunately, during the study, 36 patients in the first group and 16 in the second group died. The first group was treated initially with vitamin B12 for 2 months and with folic acid for a following 2 months. The second group was treated initially with folic acid and then with vitamin B12. Samples were drawn before administration of either, after the first and second periods, and again 2 months after treatment.

Results: The concentrations of tHcy decreased in both groups after the consecutive vitamin therapies, and the decrease was genotype-dependent. The decrease was greater for the T/T genotype (P <0.05) and was more significant when the treatment was started with folic acid (P <0.01).

Conclusion: The alternating vitamin treatment demonstrated for the first time the importance of folate therapy and the secondary contribution of vitamin B12in lowering tHcy in HD patients.
Conflict between Guideline Methodologic Quality and Recommendation Validity: A Potential Problem for Practitioners
Authors: Watine Joseph , Friedberg Bruno , Nagy Eva , Onody Rita , Oosterhuis Wytze , Bunting Peter S , Charet Jean-Christophe , Horvath Andrea Rita
Published: January 2006

Background: It is not clear if good methodologic quality in current practice guidelines necessarily leads to more valid recommendations, i.e., those that are supported with consistent research evidence or, when evidence is conflicting or lacking, with sufficient consensus among the guideline development team. To help clarify this issue, we assessed whether there is a link between methodologic quality and recommendation validity in practice guidelines for the use of laboratory tests in the management of patients with non-small cell lung cancer (NSCLC).

Methods: We conducted a systematic review of data on laboratory tests in NSCLC published in English or in French within the last 10 years and retrieved 11 practice guidelines for the use of these tests. The guidelines were critically appraised and scored for methodologic quality and recommendation validity based on the Appraisal of Guidelines Research and Evaluation (AGREE) criteria and on the systematic review.

Results: Overall, these 11 guidelines had considerable shortcomings in methodologic quality and, to a lesser extent, in recommendation validity. Practice guidelines with the best methodologic quality were not necessarily the most valid in their recommendations, and conversely.

Conclusions: Poor methodologic quality and lack of recommendation validity in laboratory medicine call for methodologic standards of guideline development and for international collaboration of guideline development agencies. We advise readers of guidelines to critically evaluate the methods used as well as the content of the recommendations before adopting them for use in practice.
Genotyping of the Lactase-Phlorizin Hydrolase −13910 Polymorphism by LightCycler PCR and Implications for the Diagnosis of Lactose Intolerance
Authors: Bodlaj Gerd , Stöcher Markus , Hufnagl Peter , Hubmann Rainer , Biesenbach Georg , Stekel Herbert , Berg Jörg
Published: January 2006

Background: Hypolactasia and lactose intolerance are common conditions worldwide. Hypolactasia seems to be strongly correlated with genotype C/C of the genetic variant C→T−13910 upstream of the lactase phlorizin hydrolase (LPH) gene. We developed a rapid genotyping assay for LPH C→T−13910 and investigated the relationship of positive lactose breath hydrogen test (LBHT) results suggesting lactose intolerance with LPH C→T−13910 genotype.

Methods: Using automated DNA purification on the MagNA Pure LC and real-time PCR on the LightCycler, we examined samples from 220 individuals to estimate genotype frequencies; we then determined LPH C→T−13910 genotype in samples from 54 Caucasian patients with a positive LBHT result and symptoms of lactose intolerance.

Results: Genotyping of 220 individuals revealed frequencies of 21.4%, 41.8%, and 36.8% for genotypes C/C, C/T, and T/T. Of the patients with positive LBHT results, only 50% had the C/C genotype suggestive of primary adult hypolactasia in our study population. The other patients had various degrees of secondary hypolactasia or symptoms of lactose intolerance. Patients with C/C genotype had a mean (SD) peak H2 increase in the LBHT [108 (58) ppm] that was significantly higher than in patients with the C/T [65 (54) ppm] and T/T [44 (34) ppm] genotypes.

Conclusions: The new real-time PCR assay provides a rapid, labor-saving means for the genotyping of LPH C→T−13910. Use of the assay may assist in differentiating patients with primary hypolactasia from those with secondary hypolactasia and lactose intolerance, who may need further clinical examinations to diagnose their underlying primary diseases.
Ipsilateral Hand Input to Area 3b Revealed by Converging Hemodynamic and Electrophysiological Analyses in Macaque Monkeys
Authors: Lipton Michael L. , Fu Kai-Ming G. , Branch Craig A. , Schroeder Charles E.
Published: January 2006

Functional magnetic resonance imaging (fMRI) of the hand representation in primary somatosensory cortex (area 3b) of macaque monkeys revealed an ipsilateral hand input undetected by most previous studies. Ipsilateral responses had a hemodynamic signature indistinguishable from that of contralateral hand responses. We explored the neural mechanisms of the fMRI effects using a second derivative analysis of field potentials [current source density (CSD) analysis] combined with action potential profiles, sampled from area 3b using linear array multielectrodes. In contrast to the predominantly excitatory contralateral response, the colocated ipsilateral response appeared dominated by inhibition, suggesting that ipsilateral inputs may have modulatory effects on contralateral input processing. Our findings confirm bimanual convergence at the earliest stage of cortical somatosensory processing in primates. They also illustrate the value of combined CSD and fMRI analyses in monkeys for defining hidden aspects of sensory function and for investigating the neuronal processes generating fMRI signals.
Branch-Specific Ca2+Influx from Na+-Dependent Dendritic Spikes in Olfactory Granule Cells
Authors: Zelles Tibor , Boyd Jamie D. , Hardy Alexandre B. , Delaney Kerry R.
Published: January 2006

Two-photon laser scanning microscopy was used to correlate electrical events detected with whole-cell somatic recordings to Ca2+transients in dendrites of olfactory bulb granule cells. A subset of spontaneous subthreshold depolarizing events recorded at the soma were shown to correspond to suprathreshold dendritic, Na-dependent action potentials [APs; dendritic spikes (D-spikes)]. These potentials were blocked by intracellular QX-314 (lidocaineN-ethyl bromide), hyperpolarizing current injection at the soma, and by partial inhibition of AMPA/kainate receptors with 0.75 μmDNQX. They were affected only slightly by 100 μmNiCl2. The majority of D-spikes recorded at the soma had a time to peak of <4 ms, comparable with somatic APs, a nonexponential decay, and amplitudes between 3 and 21 mV. Somatically recorded APs produced Ca2+transients that were observed in spines and dendrites in all parts of the cell. Ca2+transients from D-spikes were restricted to subsets of distal dendrites and their associated spines but were absent from the soma and dendrite within ∼50–80 μm of the soma. Ca2+transients in different branches could be correlated with different-sized D-spikes. D-spike and backpropagating AP-induced Ca2+transients summed in dendrites, provided the interval between them was >5–6 ms. Generation of a D-spike in a particular dendrite <5–6 ms before a somatic AP blocked backpropagation of the somatic AP into that dendrite. The temporally specific interplay between D-spikes and backpropagating APs may play a role in regulating feedback and feedforward inhibition of groups of mitral cells synapsing on different granule cell dendrites.
Cognitive Disorganization in Hippocampus: A Physiological Model of the Disorganization in Psychosis
Authors: Olypher Andrey V. , Klement Daniel , Fenton André A.
Published: January 2006

Cognitive coordination refers to processes that organize the timing of activity among neurons without altering individual discharge properties. Coordinating processes allow neural networks to coactivate related representations and prevent the coactivation of unrelated representations. Impaired cognitive coordination, also called cognitive disorganization, is hypothesized to be the core deficit in the disorganized syndrome of schizophrenia (Phillips and Silverstein, 2003), a condition characterized by hallucinations, disorganization, and thought disorder. This disorganization hypothesis is based on the observation that schizophrenic subjects are impaired at segregating relevant and irrelevant stimuli and selectively using associations between relevant cues. We report that injecting the neural activity blocker tetrodotoxin (TTX) into one hippocampus persistently coactivated pyramidal cells in the uninjected hippocampus that initially discharged independently. In accord with the definition of cognitive disorganization, pyramidal cell firing rates only changed for 15 min and did not accompany the coactivation. The TTX-induced coactivity was maximal at gamma periods, consistent with altered gamma oscillations and disorganization in schizophrenia. A network model confirmed that increasing the coupling of weakly associated cells impairs the selective activation and inhibition of stored spatial representations. This TTX-induced cognitive disorganization correctly predicted that the same TTX injection selectively impaired the ability of rats to segregate relevant associations among distal spatial stimuli from irrelevant local stimuli (Wesierska et al., 2005). The TTX-induced coactivity of hippocampal pyramidal cell discharge has construct and predictive validity as a physiological model of psychosis-related disorganization.
Identification of Wake-Active Dopaminergic Neurons in the Ventral Periaqueductal Gray Matter
Authors: Lu Jun , Jhou Thomas C. , Saper Clifford B.
Published: January 2006

Recent evidence suggests that dopamine plays an important role in arousal, but the location of the dopaminergic neurons that may regulate arousal remains unclear. It is sometimes assumed that the dopaminergic neurons in the ventral tegmental area that project to the prefrontal cortex and striatum may regulate the state of arousal; however, the firing of these dopaminergic neurons does not correlate with overall levels of behavioral wakefulness. We identified wake-active dopaminergic neurons by combining immunohistochemical staining for Fos and tyrosine hydroxylase (TH) in awake and sleeping rats. Approximately 50% of the TH-immunoreactive (TH-ir) cells in the ventral periaqueductal gray matter (vPAG) expressed Fos protein during natural wakefulness or wakefulness induced by environmental stimulation, but none expressed Fos during sleep. Fos immunoreactivity was not seen in the substantia nigra TH-immunoreactive cells in either condition. Injections of 6-hydroxydopamine into the vPAG, which killed 55–65% of wake-active TH-ir cells but did not injure nearby serotoninergic cells, increased total daily sleep by ∼20%. By combining retrograde and anterograde tracing, we showed that these wake-active dopaminergic cells have extensive reciprocal connections with the sleep–wake regulatory system. The vPAG dopaminergic cells may provide the long-sought ascending dopaminergic waking influence. In addition, their close relationship with the dorsal raphe nucleus will require reassessment of previous studies of the role of the dorsal raphe nucleus in sleep, because many of those experiments may have been confounded by the then-unrecognized presence of intermingled wake-active dopaminergic neurons.
Mislocalization of Perceived Saccade Target Position Induced by Perisaccadic Visual Stimulation
Authors: Awater Holger , Lappe Markus
Published: January 2006

The perceptual localization of objects flashed at the time of a saccade often shows large spatial distortions. These perisaccadic mislocalizations exhibit different spatial patterns depending on the experimental condition. In darkness, when only extraretinal information is available, mislocalization is spatially uniform. In light and when visual references are available, mislocalization is directed toward the saccade target, resembling a compression of visual space. These patterns are derived from measurements of the absolute perceived position of the flashed object in egocentric space. Here, we report that also the perceived location of the saccade target is altered when an object is flashed perisaccadically. The mislocalization of the target depends on the presentation time of the flashed object and is directed toward the position of the flash. The resulting compression of the relative distance between target and flash is similar in darkness and in light and can also be found during fixation. When the localization of the flashed object is described relative to the perceived location of the saccade target, spatial compression becomes similar in many experimental conditions. We therefore suggest that perisaccadic compression relies on an encoding of relative spatial locations of objects rather than on localizations in egocentric space.
Learning and Memory and Synaptic Plasticity Are Impaired in a Mouse Model of Rett Syndrome
Authors: Moretti Paolo , Levenson Jonathan M. , Battaglia Fortunato , Atkinson Richard , Teague Ryan , Antalffy Barbara , Armstrong Dawna , Arancio Ottavio , Sweatt J. David , Zoghbi Huda Y.
Published: January 2006

Loss-of-function mutations or abnormal expression of the X-linked gene encoding methyl CpG binding protein 2 (MeCP2) cause a spectrum of postnatal neurodevelopmental disorders including Rett syndrome (RTT), nonsyndromic mental retardation, learning disability, and autism. Mice expressing a truncated allele ofMecp2(Mecp2308) reproduce the motor and social behavior abnormalities of RTT; however, it is not known whether learning deficits are present in these animals. We investigated learning and memory, neuronal morphology, and synaptic function inMecp2308mice. Hippocampus-dependent spatial memory, contextual fear memory, and social memory were significantly impaired inMecp2308mutant males (Mecp2308/Y). The morphology of dendritic arborizations, the biochemical composition of synaptosomes and postsynaptic densities, andbrain-derived neurotrophic factorexpression were not altered in these mice. However, reduced postsynaptic density cross-sectional length was identified in asymmetric synapses of area CA1 of the hippocampus. In the hippocampus of symptomaticMecp2308/Ymice, Schaffer-collateral synapses exhibited enhanced basal synaptic transmission and decreased paired-pulse facilitation, suggesting that neurotransmitter release was enhanced. Schaffer-collateral long-term potentiation (LTP) was impaired. LTP was also reduced in the motor and sensory regions of the neocortex. Finally, very early symptomaticMecp2308/Ymice had increased basal synaptic transmission and deficits in the induction of long-term depression. These data demonstrate a requirement for MeCP2 in learning and memory and suggest that functional and ultrastructural synaptic dysfunction is an early event in the pathogenesis of RTT.
Transcriptional Profiling of the Developing Rat Brain Reveals That the Most Dramatic Regional Differentiation in Gene Expression Occurs Postpartum
Authors: Stead John D. H. , Neal Charles , Meng Fan , Wang Yongjia , Evans Simon , Vazquez Delia M. , Watson Stanley J. , Akil Huda
Published: January 2006

Neural development involves the expression of ensembles of regulatory genes that control the coordinate and region-specific expression of a host of other genes, resulting in the unique structure, connectivity, and function of each brain region. Although the role of some specific genes in neural development has been studied in detail, we have no global view of the orchestration of spatial and temporal aspects of gene expression across multiple regions of the developing brain. To this end, we used transcriptional profiling to examine expression levels of 9955 genes in the hypothalamus, hippocampus, and frontal cortex across seven stages of postnatal development and up to four stages of prenatal development in individual male rats (six per group). The results reveal dramatic changes across development in >97% of the neurally expressed genes. They also uncover a surprising degree of regional differentiation occurring after birth and through the first 2 weeks of life. Cluster analysis identifies 20 clusters of transcripts enriched in genes related to particular functions, such as DNA metabolism, nuclear function, synaptic vesicle transport, myelination, and neuropeptide hormone activity. Thus, groups of genes with related functions change in the brain at specific times, possibly marking critical periods for each function. These findings can broadly serve as a backdrop for studying the role of individual genes in neural development. They also underscore the importance of early postnatal life in the rat, which corresponds to late gestation in the human, as a critical late phase of neural organization and differentiation, even in subcortical regions.