bluuebunny/crossref_metadata_2025 huggingface dataset:
A single mutation in the first transmembrane domain of yeast
COX2
enables its allotopic expression
Authors: Supekova Lubica , Supek Frantisek , Greer John E. , Schultz Peter G.
Published: March 2010

During the course of evolution, a massive reduction of the mitochondrial genome content occurred that was associated with transfer of a large number of genes to the nucleus. To further characterize factors that control the mitochondrial gene transfer/retention process, we have investigated the barriers to transfer of yeast
COX2
, a mitochondrial gene coding for a subunit of cytochrome
c
oxidase complex. Nuclear-recoded
Saccharomyces cerevisiae COX2
fused at the amino terminus to various alternative mitochondrial targeting sequences (MTS) fails to complement the growth defect of a yeast strain with an inactivated mitochondrial
COX2
gene, even though it is expressed in cells. Through random mutagenesis of one such hybrid
MTS-COX2
, we identified a single mutation in the first Cox2 transmembrane domain (W56 → R) that (
i
) results in the cellular expression of a Cox2 variant with a molecular mass indicative of MTS cleavage, which (
ii
) supports growth of a
cox2
mutant on a nonfermentable carbon source, and that (
iii
) partially restores cytochrome
c
oxidase-specific respiration by the mutant mitochondria.

COX2
W56R

can be allotopically expressed with an MTS derived from
S. cerevisiae OXA1
or
Neurospora crassa SU9
, both coding for hydrophobic mitochondrial proteins, but not with an MTS derived from the hydrophilic protein Cox4. In contrast to some other previously transferred genes, allotopic
COX2
expression is not enabled or enhanced by a 3′-UTR that localizes mRNA translation to the mitochondria, such as yeast

ATP2
3

′
-UTR

. Application of in vitro evolution strategies to other mitochondrial genes might ultimately lead to yeast entirely lacking the mitochondrial genome, but still possessing functional respiratory capacity.
Dose-dependent induction of distinct phenotypic responses to Notch pathway activation in mammary epithelial cells
Authors: Mazzone Marco , Selfors Laura M. , Albeck John , Overholtzer Michael , Sale Sanja , Carroll Danielle L. , Pandya Darshan , Lu Yiling , Mills Gordon B. , Aster Jon C. , Artavanis-Tsakonas Spyros , Brugge Joan S.
Published: March 2010

Aberrant activation of Notch receptors has been implicated in breast cancer; however, the mechanisms contributing to Notch-dependent transformation remain elusive because Notch displays dichotomous functional activities, promoting both proliferation and growth arrest. We investigated the cellular basis for the heterogeneous responses to Notch pathway activation in 3D cultures of MCF-10A mammary epithelial cells. Expression of a constitutively active Notch-1 intracellular domain (NICD) was found to induce two distinct types of 3D structures: large, hyperproliferative structures and small, growth-arrested structures with reduced cell-to-matrix adhesion. Interestingly, we found that these heterogeneous phenotypes reflect differences in Notch pathway activation levels; high Notch activity caused down-regulation of multiple matrix-adhesion genes and inhibition of proliferation, whereas low Notch activity maintained matrix adhesion and provoked a strong hyperproliferative response. Moreover, microarray analyses implicated NICD-induced p63 down-regulation in loss of matrix adhesion. In addition, a reverse-phase protein array-based analysis and subsequent loss-of-function studies identified STAT3 as a dominant downstream mediator of the NICD-induced outgrowth. These results indicate that the phenotypic responses to Notch are determined by the dose of pathway activation; and this dose affects the balance between growth-stimulative and growth-suppressive effects. This unique feature of Notch signaling provides insights into mechanisms that contribute to the dichotomous effects of Notch during development and tumorigenesis.
Full-length extracellular region of the var2CSA variant of PfEMP1 is required for specific, high-affinity binding to CSA
Authors: Srivastava Anand , Gangnard Stéphane , Round Adam , Dechavanne Sébastien , Juillerat Alexandre , Raynal Bertrand , Faure Grazyna , Baron Bruno , Ramboarina Stéphanie , Singh Saurabh Kumar , Belrhali Hassan , England Patrick , Lewit-Bentley Anita , Scherf Artur , Bentley Graham A. , Gamain Benoît
Published: March 2010

Pregnancy-associated malaria (PAM) is a serious consequence of sequestration of
Plasmodium falciparum
-parasitized erythrocytes (PE) in the placenta through adhesion to chondroitin sulfate A (CSA) present on placental proteoglycans. Recent work implicates var2CSA, a member of the PfEMP1 family, as the mediator of placental sequestration and as a key target for PAM vaccine development. Var2CSA is a 350 kDa transmembrane protein, whose extracellular region includes six Duffy-binding-like (DBL) domains. Due to its size and high cysteine content, the full-length var2CSA extracellular region has not hitherto been expressed in heterologous systems, thus limiting investigations to individual recombinant domains. Here we report for the first time the expression of the full-length var2CSA extracellular region (domains DBL1X to DBL6
ε
) from the 3D7 parasite strain using the human embryonic kidney 293 cell line. We show that the recombinant extracellular var2CSA region is correctly folded and that, unlike the individual DBL domains, it binds with high affinity and specificity to CSA (
K

D

 = 61 nM) and efficiently inhibits PE from binding to CSA. Structural characterization by analytical ultracentrifugation and small-angle x-ray scattering reveals a compact organization of the full-length protein, most likely governed by specific interdomain interactions, rather than an extended structure. Collectively, these data suggest that a high-affinity, CSA-specific binding site is formed by the higher-order structure of the var2CSA extracellular region. These results have important consequences for the development of an effective vaccine and therapeutic inhibitors.
Magnetically driven three-dimensional manipulation and inductive heating of magnetic-dispersion containing metal alloys
Authors: Calabro Joshua D. , Huang Xu , Lewis Brian G. , Ramirez Ainissa G.
Published: March 2010

Fundamental to the development of three-dimensional microelectronic fabrication is a material that enables vertical geometries. Here we show low-melting-point metal alloys containing iron dispersions that can be remotely manipulated by magnetic fields to create vertical geometries and thus enable novel three-dimensional assemblies. These iron dispersions enhance the mechanical properties needed for strong, reliable interconnects without significantly altering the electrical properties of the alloys. Additionally, these iron dispersions act as susceptors for magnetic induction heating, allowing the rapid melting of these novel alloys at temperatures lower than those usually reported for conventional metal alloys. By localizing high temperatures and by reducing temperature excursions, the materials and methods described have potential in a variety of device fabrication applications.
Centrosomes remember which way is up
Authors: Leslie Mitch
Published: March 2010

Microtubule-based memory helps orient dividing brain stem cells.
The interphase microtubule aster is a determinant of asymmetric division orientation in Drosophila neuroblasts
Authors: Januschke Jens , Gonzalez Cayetano
Published: March 2010

The mechanisms that maintain the orientation of cortical polarity and asymmetric division unchanged in consecutive mitoses in Drosophila melanogaster neuroblasts (NBs) are unknown. By studying the effect of transient microtubule depolymerization and centrosome mutant conditions, we have found that such orientation memory requires both the centrosome-organized interphase aster and centrosome-independent functions. We have also found that the span of such memory is limited to the last mitosis. Furthermore, the orientation of the NB axis of polarity can be reset to any angle with respect to the surrounding tissue and is, therefore, cell autonomous.
Integration of contractile forces during tissue invagination
Authors: Martin Adam C. , Gelbart Michael , Fernandez-Gonzalez Rodrigo , Kaschube Matthias , Wieschaus Eric F.
Published: March 2010

Contractile forces generated by the actomyosin cytoskeleton within individual cells collectively generate tissue-level force during epithelial morphogenesis. During Drosophila mesoderm invagination, pulsed actomyosin meshwork contractions and a ratchet-like stabilization of cell shape drive apical constriction. Here, we investigate how contractile forces are integrated across the tissue. Reducing adherens junction (AJ) levels or ablating actomyosin meshworks causes tissue-wide epithelial tears, which release tension that is predominantly oriented along the anterior–posterior (a-p) embryonic axis. Epithelial tears allow cells normally elongated along the a-p axis to constrict isotropically, which suggests that apical constriction generates anisotropic epithelial tension that feeds back to control cell shape. Epithelial tension requires the transcription factor Twist, which stabilizes apical myosin II, promoting the formation of a supracellular actomyosin meshwork in which radial actomyosin fibers are joined end-to-end at spot AJs. Thus, pulsed actomyosin contractions require a supracellular, tensile meshwork to transmit cellular forces to the tissue level during morphogenesis.
CCR6 is expressed on an IL-10–producing, autoreactive memory T cell population with context-dependent regulatory function
Authors: Rivino Laura , Gruarin Paola , Häringer Barbara , Steinfelder Svenja , Lozza Laura , Steckel Bodo , Weick Anja , Sugliano Elisa , Jarrossay David , Kühl Anja A. , Loddenkemper Christoph , Abrignani Sergio , Sallusto Federica , Lanzavecchia Antonio , Geginat Jens
Published: March 2010

Interleukin (IL)-10 produced by regulatory T cell subsets is important for the prevention of autoimmunity and immunopathology, but little is known about the phenotype and function of IL-10–producing memory T cells. Human CD4+CCR6+ memory T cells contained comparable numbers of IL-17– and IL-10–producing cells, and CCR6 was induced under both Th17-promoting conditions and upon tolerogenic T cell priming with transforming growth factor (TGF)–β. In normal human spleens, the majority of CCR6+ memory T cells were in the close vicinity of CCR6+ myeloid dendritic cells (mDCs), and strikingly, some of them were secreting IL-10 in situ. Furthermore, CCR6+ memory T cells produced suppressive IL-10 but not IL-2 upon stimulation with autologous immature mDCs ex vivo, and secreted IL-10 efficiently in response to suboptimal T cell receptor (TCR) stimulation with anti-CD3 antibodies. However, optimal TCR stimulation of CCR6+ T cells induced expression of IL-2, interferon-γ, CCL20, and CD40L, and autoreactive CCR6+ T cell lines responded to various recall antigens. Notably, we isolated autoreactive CCR6+ T cell clones with context-dependent behavior that produced IL-10 with autologous mDCs alone, but that secreted IL-2 and proliferated upon stimulation with tetanus toxoid. We propose the novel concept that a population of memory T cells, which is fully equipped to participate in secondary immune responses upon recognition of a relevant recall antigen, contributes to the maintenance of tolerance under steady-state conditions.
Isoform-specific p73 knockout mice reveal a novel role for ΔNp73 in the DNA damage response pathway
Authors: Wilhelm Margareta T. , Rufini Alessandro , Wetzel Monica K. , Tsuchihara Katsuya , Inoue Satoshi , Tomasini Richard , Itie-Youten Annick , Wakeham Andrew , Arsenian-Henriksson Marie , Melino Gerry , Kaplan David R. , Miller Freda D. , Mak Tak W.
Published: March 2010

Mice with a complete deficiency of p73 have severe neurological and immunological defects due to the absence of all TAp73 and ΔNp73 isoforms. As part of our ongoing program to distinguish the biological functions of these isoforms, we generated mice that are selectively deficient for the ΔNp73 isoform. Mice lacking ΔNp73 (ΔNp73−/− mice) are viable and fertile but display signs of neurodegeneration. Cells from ΔNp73−/− mice are sensitized to DNA-damaging agents and show an increase in p53-dependent apoptosis. When analyzing the DNA damage response (DDR) in ΔNp73−/− cells, we discovered a completely new role for ΔNp73 in inhibiting the molecular signal emanating from a DNA break to the DDR pathway. We found that ΔNp73 localizes directly to the site of DNA damage, can interact with the DNA damage sensor protein 53BP1, and inhibits ATM activation and subsequent p53 phosphorylation. This novel finding may explain why human tumors with high levels of ΔNp73 expression show enhanced resistance to chemotherapy.
Stream acidification increases nitrogen uptake by leaf biofilms: implications at the ecosystem scale
Authors: ELY DAMON T. , VON SCHILLER DANIEL , VALETT H. MAURICE
Published: March 2010

1. While anthropogenic stream acidification is known to lower species diversity and impair decomposition, its effects on nutrient cycling remain unclear. The influence of acid‐stress on microbial physiology can have implications for carbon (C) and nitrogen (N) cycles, linking environmental conditions to ecosystem processes.

2. We collected leaf biofilms from streams spanning a gradient of pH (5.1–6.7), related to chronic acidification, to investigate the relationship between qCO2 (biomass‐specific respiration; mg CO2‐C g−1 fungal C h−1), a known indicator of stress, and biomass‐specific N uptake (μg NH4‐N mg−1 fungal biomass h−1) at two levels of N availability (25 and 100 μg NH4‐N L−1) in experimental microcosms.

3. Strong patterns of increasing qCO2 (i.e. increasing stress) and increasing microbial N uptake were observed with a decrease in ambient (i.e. chronic) stream pH at both levels of N availability. However, fungal biomass was lower on leaves from more acidic streams, resulting in lower overall respiration and N uptake when rates were standardized by leaf biomass.

4. Results suggest that chronic acidification decreases fungal metabolic efficiency because, under acid conditions, these organisms allocate more resources to maintenance and survival and increase their removal of N, possibly via increased exoenzyme production. At the same time, greater N availability enhanced N uptake without influencing CO2 production, implying increased growth efficiency.

5. At the ecosystem level, reductions in growth because of chronic acidification reduce microbial biomass and may impair decomposition and N uptake; however, in systems where N is initially scarce, increased N availability may alleviate these effects. Ecosystem response to chronic stressors may be better understood by a greater focus on microbial physiology, coupled elemental cycling, and responses across several scales of investigation.
Influence of post pattern and resin cement curing mode on the retention of glass fibre posts
Authors: Poskus L. T. , Sgura R. , Paragó F. E. M. , Silva E. M. , Guimarães J. G. A.
Published: March 2010

Poskus LT, Sgura R, Paragó FEM, Silva EM, Guimarães JGA. Influence of post pattern and resin cement curing mode on the retention of glass fibre posts. International Endodontic Journal, 43, 306–311, 2010.

Aim  To evaluate the influence of post design and roughness and cement system (dual‐ or self‐cured) on the retention of glass fibre posts.

Methodology  Two tapered and smooth posts (Exacto Cônico No. 2 and White Post No. 1) and two parallel‐sided and serrated posts (Fibrekor 1.25 mm and Reforpost No. 2) were adhesively luted with two different resin cements – a dual‐cured (Rely‐X ARC) and a self‐cured (Cement Post) – in 40 single‐rooted teeth. The teeth were divided into eight experimental groups (n = 5): PFD – Parallel‐serrated‐Fibrekor/dual‐cured; PRD – Parallel‐serrated‐Reforpost/dual‐cured; TED – Tapered‐smooth‐Exacto Cônico/dual‐cured; TWD – Tapered‐smooth‐White Post/dual‐cured; PFS – Parallel‐serrated‐Fibrekor/self‐cured; PRS – Parallel‐serrated‐Reforpost/self‐cured; TES – Tapered‐smooth‐Exacto Cônico/self‐cured; TWS – Tapered‐smooth‐White Post/self‐cured. The specimens were submitted to a pull‐out test at a crosshead speed of 0.5 mm min−1. Data were analysed using analysis of variance and Bonferroni’s multiple comparison test (α = 0.05).

Results  Pull‐out results (MPa) were: PFD = 8.13 (±1.71); PRD = 8.30 (±0.46); TED = 8.68 (±1.71); TWD = 9.35 (±1.99); PFS = 8.54 (±2.23); PRS = 7.09 (±1.96); TES = 8.27 (±3.92); TWS = 7.57 (±2.35). No statistical significant difference was detected for posts and cement factors and their interaction.

Conclusions  The retention of glass fibre posts was not affected by post design or surface roughness nor by resin cement‐curing mode. These results imply that the choice for serrated posts and self‐cured cements is not related to an improvement in retention.
The influence of pain catastrophising on the experience of persistent pain/discomfort following non‐surgical root canal treatment
Authors: Philpott R. , Gulabivala K. , Ng Y.‐L.
Published: March 2010

Aims  To (i) determine the prevalence and influence of pain catastrophising on pain/discomfort experience associated with teeth demonstrating periapical healing following non‐surgical root canal treatment (NSRCT); (ii) investigate common descriptors for characterising the pain/discomfort sensation.

Methodology  A total of 198 patients (264 teeth) were examined clinically and radiographically 5–14 months after completion of NSRCT. All the radiographs were assessed by one observer and 33% were additionally examined independently by a pre‐calibrated second observer. Each tooth was classified into complete, incomplete, uncertain healing and failed to heal groups. Detailed pain histories were obtained using the Short Form of the McGill Pain Questionnaire. The pain catastrophising score for each case was determined using the Pain Catastrophising Scale (PCS) questionnaire. Cohen's kappa coefficients were calculated to assess intra‐ and inter‐observer agreement on radiographic examination. Multiple logistic regression models were employed to investigate the association between prevalence of pain/discomfort and pain catastrophising as well as other potential influencing factors. Clustering effects within patients were adjusted using robust standard error.

Results  In total, 25% (n = 62/249) of teeth showing signs of periapical healing were associated with pain/discomfort on review. The most commonly used descriptors for the pain/discomfort sensation were ‘Sensitivity’, ‘aching’, ‘tender’ and ‘throbbing’. Intra‐ and inter‐observer agreements were substantial (0.8 and 0.6, respectively). The PCS score had no significant association with pain/discomfort experience after NSRCT (OR = 1.3, 95% CI 0.3, 1.1). Significant factors affecting the prevalence of pain/discomfort included: history of chronic pain (OR = 3.5, 95% CI 1.5, 8.4); pre‐operative vital pulp (OR = 5.2, 95% CI 1.5, 18.1); presence of pre‐operative pain (OR = 2.9, 95% CI 1.1, 8.1); presence of a pre‐operative crack (OR = 2.5, 95% CI 1.0, 6.3); and size of pre‐operative periapical lesion (OR = 0.85, 95% CI 0.77, 0.95).

Conclusions  Twenty‐five per cent of teeth showing signs of periapical healing had pain/discomfort characterised by typical descriptors; with five significant predicting factors. Pain catastrophising did not predict the occurrence of post‐operative pain/discomfort. Further monitoring of the clinical course of prevalent pain/discomfort associated with periapical healing should inform future decision‐making on further management.
The efficacy of different endodontic irrigants against Enterococcus faecalis in an extracted human tooth model
Authors: Giles L.H. , Chan S.N. , Jarad F. , Hope C.
Published: March 2010

Aim  To investigate, in vitro, the efficacy of sodium hypochlorite (NaOCl), super‐oxidized water (Sterilox® Optident, Ilkely, UK) and chlorhexidine gluconate (CHX) as endondontic irrigants using an extracted human tooth model in a cross over Latin square study design.

Methodology  Twelve extracted, human single rooted teeth were prepared for endodontic treatment using the modified double flare method to a master apical file size 40 K‐file. The roots and apices of all teeth were sealed using a dentine bonding agent. The teeth were mounted in cold cure silicone and placed in glass jars before autoclaving. An overnight sample of Enterococcus faecalis grown in brain heart infusion (BHI) was centrifuged and washed using phosphate buffered solution (PBS) before being suspended in fresh BHI. Optical density of the culture was adjusted to 0.1 units at 650 nm before inoculating 20 μL into the canals of the prepared teeth. Inoculated teeth were incubated at 37 °C for 48 h. The teeth were divided into four groups of three teeth, which were irrigated with NaOCl (1%), Sterilox, CHX (2%), and the control, PBS during cycles of experimentation. The teeth were irrigated using 5 × 200 μL of an endodontic irrigant using an electronic pipette, according to the Latin square. Irrigants were left in situ for 60 s after which teeth were flushed with PBS. Five size 40 sterile paper points were used to collect the microbial sample from the root canals. The number of viable bacteria recovered from the canals was determined through serial dilutions and plating of these onto nutrient agar. The logarithm of the colony forming units was used to carry out statistical analysis. The antimicrobial efficacy of the irrigants was compared using analysis of variance (anova) and Tukey post‐hoc analysis at a significance level of P < 0.05 to determine whether there are differences in efficacy of the irrigants investigated.

Results  NaOCl, Sterilox and CHX were significantly more effective than the control, PBS, at reducing the bacterial load within the root canals. There was no significant difference between the efficacy of NaOCl, Sterilox and CHX in reducing bacterial load.

Conclusion  The study showed that using a cross over Latin square design eliminates bias in results due to the use of different teeth. NaOCl, Sterilox and CHX had a greater antibacterial efficacy that the control, PBS. Statistically there was no significant difference between NaOCl, Sterilox and CHX.
The effect of working length and root canal preparation technique on crack development in the apical root canal wall
Authors: Adorno C. G. , Yoshioka T. , Suda H.
Published: March 2010

Adorno CG, Yoshioka T, Suda H. The effect of working length and root canal preparation technique on crack development in the apical root canal wall. International Endodontic Journal, 43, 321–327, 2010.

Aim  To evaluate the effects of working length and root canal preparation technique on crack development in the apical root canal wall.

Methodology  Seventy extracted mandibular premolars were mounted in a resin block with simulated periodontal ligaments and divided into seven groups according to preparation technique and working length: group A, step‐back preparation with stainless steel files with working length set at the apical foramen and defined as root canal length (CL); group B, same as for A, except that the working length was CL–1 mm; group C, crown‐down preparation with Profile instruments followed by an apical enlargement sequence with CL as working length and group D, same as for C, except that the working length was CL–1 mm. Groups E, F and G served as controls. Groups E and F were prepared only with the crown‐down sequence up to CL and CL–1 mm, respectively. Group G was left unprepared. Digital images of the apical root surface (AS) were recorded before preparation, immediately after instrumentation and after removing the apical 1 mm (AS–1 mm) and 2 mm (AS–2 mm) of the root end.

Results  Working length significantly affected crack development at AS (P < 0.05). Preparation technique significantly affected crack development at AS–1 mm (P < 0.05). At AS–2 mm, there was no significant difference between preparation technique and working length in terms of crack development on the canal wall.

Conclusion  Root canal preparation alone, regardless of the technique used, can potentially generate cracks on the apical root canal wall as well as the apical surface. Working 1‐ mm short of the apical foramen might produce fewer cracks in the apical region.
Prenatal Exposure to Vinclozolin Disrupts Selective Aspects of the Gonadotrophin‐Releasing Hormone Neuronal System of the Rabbit
Authors: Wadas B. C. , Hartshorn C. A. , Aurand E. R. , Palmer J. S. , Roselli C. E. , Noel M. L. , Gore A. C. , Veeramachaneni D. N. R. , Tobet S. A.
Published: March 2010

Developmental exposure to the agricultural fungicide vinclozolin can impair reproductive function in male rabbits and was previously found to decrease the number of immunoreactive‐gonadotrophin‐releasing hormone (GnRH) neurones in the region of the organum vasculosum of the lamina terminalis and rostral preoptic area by postnatal week (PNW) 6. In the present study, in an aim to further examine the disruption of GnRH neurones by foetal vinclozolin exposure, pregnant rabbits were dosed orally with vinclozolin, flutamide or carrot paste vehicle for the last 2 weeks of gestation. Offspring were euthanised at birth (males and females), PNW 6 (females), PNW 26 (adult males) or PNW 30 (adult females) of age. At birth and in adults, brains were sectioned and processed for immunoreactive GnRH. The numbers of immunoreactive GnRH neuronal perikarya were significantly decreased in vinclozolin‐treated rabbits at birth and in adult littermates. By contrast, there was an increase in GnRH immunoreactivity in the terminals in the region of the median eminence. Analysis of PNW 6 female brains by radioimmunoassay revealed a two‐fold increase in GnRH peptide content in the mediobasal hypothalamus in vinclozolin‐treated rabbits. This finding was complemented by immunofluorescence analyses, which revealed a 2.8‐fold increase in GnRH immunoreactivity in the median eminence of vinclozolin compared to vehicle‐treated females at PNW 30. However, there was no difference between treatment groups in the measures of reproduction that were evaluated: ejaculation latency, conception rates or litter size. These results indicate that sub‐acute, prenatal vinclozolin treatment is sufficient to create perdurable alterations in the GnRH neuronal network that forms an important input into the reproductive axis. Finally, the effect of vinclozolin on the GnRH neuronal network was not comparable to that of flutamide, suggesting that vinclozolin was not acting through anti‐androgenic mechanisms.
Changes in Oestrogen Receptor α Expression in the Nucleus of the Solitary Tract of the Rat Over the Oestrous Cycle and Following Ovariectomy
Authors: Spary E. J. , Maqbool A. , Batten T. F. C.
Published: March 2010

Oestrogen is capable of modulating autonomic outflow and baroreflex function via actions on groups of neurones in the brainstem. We investigated the presence of oestrogen receptor (ER) α in a part of the nucleus of the solitary tract (NTS) associated with central cardiovascular control, aiming to determine whether ERα mRNA and protein expression is correlated with levels of circulating oestrogen during the oestrous cycle. Polymerase chain reaction (PCR) detected ERα mRNA in the NTS at each stage of the oestrous cycle, from ovariectomised, sham‐operated and male rats. Real‐time PCR showed variations in ERα mRNA expression during the oestrous cycle, with the highest levels seen in oestrus, and lowest levels in metoestrus (P < 0.05 versus oestrus) and proestrus (P < 0.05 versus oestrus). Expression in males was lower than in dioestrus and oestrus females (P < 0.05). After ovariectomy, ERα mRNA levels were decreased compared to sham‐operated animals (P < 0.01). Confocal fluorescence immunohistochemistry with stereological analysis showed that numbers of ERα immunoreactive cell nuclei per mm3of tissue in the caudal NTS were significantly greater in proestrus than in other groups of rats (P < 0.05). There were also differences among the groups in the extent of colocalisation of ERα in neurones immunoreactive for tyrosine hydroxylase and nitric oxide synthase. These results imply a complex pattern of region‐specific oestrogen signalling in the NTS and suggest that ERα expression in this important autonomic nucleus may be related to circulating oestrogen levels. This may have consequences for the regulation of autonomic tone and baroreflex sensitivity when oestrogen levels decline, for example following menopause.
Direct and Indirect Effects of Cannabinoids on in vitro GABA Release in the Rat Arcuate Nucleus
Authors: Menzies J. R. W. , Ludwig M. , Leng G.
Published: March 2010

Within the hypothalamic arcuate nucleus, two neuronal subpopulations play particularly important roles in energy balance; neurones expressing neuropeptide Y (NPY), agouti‐related peptide (AgRP) and GABA are orexigenic, whereas neurones expressing pro‐opiomelanocortin and CART are anorexigenic. The pivotal role of these neuropeptides in energy homeostasis is well‐known, although GABA may also be an important signal because targeted knockout of the GABA transporter in NPY/AgRP/GABA neurones results in a lean, obesity‐resistant phenotype. In the present study, we describe an in vitro model of K+‐evoked GABA release from the hypothalamus and determine the effects of cannabinoid receptor activation. K+‐evoked GABA release was sensitive to leptin, insulin and PYY(3‐36), indicating that GABA was released by arcuate NPY/AgRP/GABA neurones. In the presence of tetrodotoxin (TTX), the cannabinoid CB1 receptor agonist WIN 55,212‐2 inhibited K+‐evoked GABA release. This was prevented by the CB1 receptor inverse agonist rimonabant. Rimonabant had no effect when applied alone. In the absence of TTX, however, the opposite effects were observed: WIN 55,212‐2 had no effect while rimonabant inhibited GABA release. This indicates that GABA release can involve an indirect, TTX‐sensitive mechanism. The most parsimonious explanation for the inhibition of GABA release by a CB receptor inverse agonist is via the disinhibition of an cannabinoid‐sensitive inhibitory input onto GABAergic neurones. One local source of an inhibitory neurotransmitter is the opioidergic arcuate neurones. In our in vitro model, K+‐evoked GABA release was inhibited by the endogenous opioid peptide β‐endorphin in a naloxone‐sensitive manner. The inhibitory effect of rimonabant was also prevented by naloxone and a κ‐opioid receptor selective antagonist, suggesting that GABA release from arcuate NPY/AgRP/GABA neurones can be inhibited by endogenous opioid peptides, and that the release of opioid peptides is sensitive to cannabinoids.
Neuropeptide AF Differentially Affects Anorexia in Lines of Chickens Selected for High or Low Body Weight
Authors: Newmyer B. A. , Siegel P. B. , Cline M. A.
Published: March 2010

The recently discovered anorectic effect of neuropeptide AF (NPAF) has not been studied in hypo‐and hyperphagia animal models. The present study was designed to examine possible differences in appetite‐related effects after central NPAF administration in lines of chickens that had undergone long‐term divergent selection for low (LWS) or high (HWS) body weight and exhibit hypo‐ and hyperphagia, respectively. LWS chicks responded at a similar magnitude of food intake reduction to all doses of NPAF tested at all observation times. HWS chicks had an increased latency (150 min versus 30 min post injection) and an increased dose threshold of response (8 nmol versus 2 nmol) than LWS chicks. Water intake of LWS chicks was reduced in all doses tested at all observation times, whereas HWS chicks responded to the three doses of NPAF tested up to 60 min post injection, after which the decrease was sustained only at a dose of 8 nmol. In a comprehensive behaviour analysis, exploratory pecks, food pecks and locomotion were significantly reduced in both lines by NPAF, whereas sit time was increased in both lines. Other behaviours, including stand time, deep rest time and escape attempts, were not affected. These data suggest that the threshold of NPAF‐induced anorexia is lower in LWS than HWS chicks and that NPAF‐induced anorexia is a primary effect in both lines, and also support the hypothesis that differences exist in the central NPAF system between hypo‐ and hyperphagic individuals.
Nexilin: a potential novel factor contributing to dilated cardiomyopathy
Authors: Franciosi S
Published: March 2010

Nexilin mutations destabilize z‐disks and lead to dilated cardiomyopathy Hassel et al. (2009)

Nature Medicine 15(11): 1281–1288
The Comparison of Antioxidative/Oxidative Profile in Colostrum, Milk and Blood of Early Post‐Partum Cows During their First and Second Lactation
Authors: Albera E , Kankofer M
Published: March 2010

Contents

The aim of the study was to compare antioxidative/oxidative profile in blood, colostrum and milk of early post‐partum cows during their first and second lactation. A total of 19 healthy, primiparous cows were included in experiment and samples were collected during 2 years from the same animals immediately after parturition, 24, 48 h as well as 6 and 12 days later. All parameters including the activity of glutathione peroxidase (GSH‐Px), total antioxidant capacity (TAC), the content of vitamin A, C as well as the contents of products of lipid and protein peroxidation were determined by the use of spectrophotometric methods. Comparing the profile within lactation, TAC and GSH‐Px activity in blood showed decreasing trends, while parameters of lipid and protein peroxidation fluctuated. All examined parameters in colostrum and milk except from intermediates of lipid peroxidation exhibited increasing trends. These results which showed dynamic changes of antioxidative/oxidative profile not only in blood but also in colostrum/milk within examined period of time suggested appropriate answer of organism to current challenge. Moreover, not uniform but detectable changes between first and second lactation suggested that two consecutive lactations are not the same. Comparing first and second lactation, TAC and parameters of lipid and protein peroxidation in blood showed increasing tendency in second as first lactation while GSH‐Px activity was opposite. The content of antioxidative vitamins and SH groups in colostrum/milk showed increasing tendency in second as first lactation, while TAC and content of end products of lipid peroxidation showed opposite trend, and GSH‐Px together with intermediates of lipid peroxidation remained stable. Molecular and biochemical background for it require further elucidation.
Determination of adenosine deaminase activity and its isoenzymes for diagnosis of pleural effusions*
Authors: Gorguner Metin , Cerci Melek , Gorguner Ilknur
Published: March 2010

Objective:

We aimed to investigate adenosine deaminase (ADA) activity and the activities of its ADA1 and ADA2 isoenzymes in pleural effusions and also sera with different aetiological origins.Methodology: The pleural effusions of 87 patients were examined. The patients were separated into four groups: transudates, parapneumonic, malignant, and tuberculous effusions. The cases were also designated as tuberculous or non‐tuberculous group. Adenosine deaminase activity was determined by the colorimetric method described by Giusti and Galanti.

Results:

The intermean differences were statistically significant for total ADA, ADA1 and ADA2, except for pleural fluid ADA1 in the malignant group when compared to the tuberculous effusion group. The intermean differences between the tuberculous and non‐tuberculous group were statistically significant for all three parameters except for pleural fluid and serum ADA1 activity. The sensitivities of total ADA, ADA1 and ADA2 activities for tuberculosis were 91, 57 and 93%, respectively; their specificities 89, 88 and 92%, respectively; their positive predictive values 82, 70 and 86%; and their diagnostic accuracies 89, 76 and 92%, respectively, in pleural fluid.

Conclusions:

Determination of ADA and its isoenzymes can help to differentiate the causes of pleural effusion. Increased ADA2 activity is a striking marker of tuberculous effusions. In contrast, increased ADA1 activity was significantly elevated in parapneumonic effusions.
Echocardiographic findings of pericardial involvement in patients with malignant pleural mesothelioma with a history of environmental exposure to asbestos and erionite
Authors: Özer Necla , Shehu Veprim , Aytemir Kudret , Övünç Kenan , Emre Salih , Kes Sirri
Published: March 2010

Objective:

The aim of the present study was to evaluate the pericardial involvement in patients with malignant mesothelioma caused by exposure to different minerals.

Methodology:

Forty‐two patients (mean age of 52 ± 12 years) with malignant mesothelioma were examined with transthoracic echocardiography. Thirty‐three (78.9%) patients had a history of environmental exposure to asbestos and nine (21.4%) had a history of environmental exposure to erionite.

Results:

In 19 (45.2%) patients with malignant pericardial mesothelioma, pericardial involvement was determined by echocardiography. The other 23 (54.8%) patients had no pericardial involvement. Pericardial effusion was detected in nine (64.3%) patients and pericardial effusion was small in six (14.3%) patients, moderate in one (2.4%) patient and large in two patients. Thickening of the pericardium was observed in eight (19%) patients. In another two (7.1%) patients pericardial calcification was observed. Among the 33 patients who had been exposed to asbestos, 15 (45.5%) had pericardial involvement, and among the nine patients with a history of exposure to erionite, four (44.4%) had pericardial involvement. There was no difference in terms of pericardial involvement in different stages of the tumour (P > 0.05).

Conclusions:

Pericardial involvement is commonly seen in patients with malignant mesothelioma. Among patients exposed to asbestos or zeolite there was no difference in terms of pericardial involvement. Furthermore, pericardial involvement was not related with the stage of the tumour.
Comparison between tidal breathing and dosimeter methods in assessing cough receptor sensitivity to capsaicin
Authors: Nejla Songur , Fujimura Masaki , Kamio Yumie
Published: March 2010

Objective:

Dosimeter method and tidal breathing method have been used to assess cough sensitivity to inhaled capsaicin, a C‐fibre ending stimulator. The aim of the present study was to evaluate the repeatability of and the agreement between the two methods.

Methodology:

Cough threshold, the lowest concentration of capsaicin causing five or more coughs, was measured twice 1–3 weeks apart by each method in 26 normal subjects. Increasing concentrations of capsaicin were inhaled by a single breath in the dosimeter method or by 15 s tidal breathing in the tidal breathing method in 1 min intervals.

Results:

Coefficients of repeatability of the cough threshold measurement were 1.89 and 2.71 doubling concentration in the tidal breathing method and the dosimeter method, respectively, suggesting good repeatability in the cough threshold measurement by both methods. The cough threshold was significantly (P< 0.0001) greater by 1.75 doubling concentration on the dosimeter method than the tidal breathing method. The coefficient of agreement between the two methods was 2.53 doubling concentration. Five subjects complained of burning sensation in the throat in the dosimeter method but no patient complained about the tidal breathing method (P< 0.05).

Conclusions:

Although the agreement between the two methods was considered to be good, higher concentrations of capsaicin solution were required to determine the cough threshold in the dosimeter method, resulting in an unpleasant sensation in the throat.
Respiratory bronchiolitis associated interstitial lung disease (RB‐ILD) presenting with haemoptysis
Authors: McWilliams Annette M. , Lake Fiona R.
Published: March 2010

Respiratory bronchiolitis associated interstitial lung disease is an uncommon condition in current or ex‐smokers. The presentation is non‐specific, but haemoptysis is uncommonly reported in this condition. We report the case of a 25‐year‐old woman who presented with significant haemoptysis, dyspnoea, reduced transfer factor and normal clinical examination. In addition, a Medline literature search was performed to review the clinical features and prognosis of this disease. Other causes of haemoptysis were excluded with extensive investigation. The diagnosis was made on thoracoscopic lung biopsy. The patient had significant postoperative complications of prolonged air leak and hydropneumothorax requiring further surgery and prolonged hospital stay. Advice regarding smoking cessation was given. Her pulmonary physiology remains abnormal on follow up but symptoms have improved. Respiratory bronchiolitis‐ILD may present with normal examination and radiology. Haemoptysis in this case may have been associated with the underlying disease but could have been incidental. Diagnosis, in general, requires lung biopsy. As in this patient, lung function does not appear to improve significantly on follow up.
Use of montelukast in the treatment of early childhood wheezing from clinical experience with three cases
Authors: Ng Daniel K. , Law Albert K. , Chau Kin‐Wai , Chan Hon‐Keung
Published: March 2010

Leukotrienes were found to be raised in respiratory syncytial virus bronchiolitis. Montelukast is a cysteinyl leukotrienes antagonist. We report our experience with the use of montelukast in three young children from 5‐months to 20‐months old. The first case was a 5‐month‐old boy with previous good health. He had prolonged respiratory distress secondary to adenovirus type 3 infection. The second case was a 20‐month‐old boy with bronchopulmonary dysplasia. He had respiratory syncytial virus and an adenovirus type 3 infection leading to prolonged wheeze. The third case was a 20‐month‐old girl with chronic lung disorder after an episode of severe E. coli pneumonia at 1 month old. She developed acute virus‐negative severe wheeze after a few days of running nose and low‐grade fever. All three cases responded poorly to inhaled steroids and bronchodilators. Addition of montelukast was associated with marked clinical improvement within 1 week. The three cases were very heterogeneous and differed from usual simple virus‐induced acute bronchiolitis. The use of multiple drugs including montelukast did not enable any definite conclusions; however, the addition of montelukast was closely related to clinical improvement. Further studies in the use of montelukast in severe virus‐induced bronchiolitis are warranted.
An unusual case of double tuberculous broncho‐oesophageal fistulas in an adult
Authors: Chan Alan Chi‐Kuen , Leung John Siu‐Man , Lee Arthur Kai‐Chung , Li Robert , Tam Cheuk‐Ming , Leung Chi‐Chiu , Law Wing‐Sze
Published: March 2010

Broncho‐oesophageal fistula associated with tuberculosis is rarely reported in the literature and has not been reported in Hong Kong. We describe a 30‐year‐old Chinese human immunodeficiency virus (HIV)‐negative man with double tuberculous broncho‐oesophageal fistulas proven by histology. Constitutional symptoms of active tuberculosis were absent and chest radiograph did not show an obvious lung lesion. Our case shows that broncho‐oesophageal fistula can be the sole manifestation of active tuberculosis and that the diagnosis should be suspected in patients who are seen with chronic respiratory symptoms in areas where the prevalence of tuberculosis is high.
The rapid diagnosis of smear‐negative pulmonary tuberculosis: A cost‐effectiveness analysis
Authors: Lim T. K. , Cherian J. , Poh K. L. , Leong T. Y.
Published: March 2010

Objective

The prompt diagnosis of smear‐negative pulmonary tuberculosis (PTB) is a clinical challenge. It may be achieved by a number of tests which have varying accuracies, costs and degrees of invasiveness. The objective of this study was to compare the cost‐effectiveness of clinical judgement (empirical), the Roche Cobas amplicor assay for Mycobacterium tuberculosis (amplicor), acid‐fast staining of bronchoalveolar lavage specimens (BAL), nucleic acid amplification tests of bronchoalveloar lavage specimens for M. tuberculosis (BAL + NAA), computed tomography (CT) and amplicor assay followed by BAL.

Methodology

The range of predictive values of the various strategies were derived from published data and a new study of 441 consecutive adult patients with suspected smear‐negative PTB prospectively stratified into three pretest risk groups: low, intermediate and high. The cost‐effectiveness was evaluated with a decision tree model (DATATM software).

Results

The incidence of PTB was 5.7% (4% culture positive) for the whole group, 95% in the high‐risk group, 0.9% in the low‐risk group and 3.4% in the intermediate‐risk group. The sensitivity of the empirical approach was 49% and of the amplicor assay was 44%. Patient outcomes were expressed as life expectancy for the base case of a 58‐year‐old man with a pretest probability of 5.7%. At this low pretest risk the differences in life expectancies between tests was < 0.1 years and the empirical approach incurred the lowest cost. Sensitivity analysis at increasing pretest risks showed better life expectancies (~1 years) for CT scan and test combinations than empirical and amplicor for additional costs of US$243–US$309. Bronchoalveolar lavage had the worst overall cost‐effectiveness.

Conclusions

We conclude that the pretest risk of active PTB was a key determinant of test utility; that the AMPLICOR assay was comparable to clinical judgement; that BAL was the least useful test; and that with increasing risks, CT scan and test combinations performed better. Further studies are needed to better define patients with intermediate risk for PTB and to directly compare the cost‐effectiveness of more sensitive nucleic acid amplification tests such as the enhanced Gen Probe, CT scan and test combinations/sequences in these patients.
Pulmonary complications in patients with AIDS: A report from a Beijing hospital
Authors: Xu Kai‐Feng , Lu Weixuan , Li Longyun , Shen Ruiyuan
Published: March 2010

Objective:

The aim of this study was to improve the awareness of pulmonary complications in patients with AIDS.

Methodology:

Nine patients with AIDS with pulmonary involvement from March 1992 to March 2000 were analysed.

Results:

Of the nine cases, there were eight cases complicated with Pneumocystis carinii pneumonia (PCP). The clinical presentation of PCP was fever (8/8), dyspnoea on exertion or at rest (7/8), and hypoxaemia with a mean PaO2 of 58 mmHg. Chest X‐ray films showed bilateral diffuse interstitial or alveolar infiltrates. Pulmonary tuberculosis, tuberculous lymphadenitis and bronchial fungal infection were found in three cases.

Conclusions:

AIDS patients are at high risk of suffering from pulmonary complications, of which PCP is most common. If young patients who were healthy in the past suddenly suffered from pneumonia and respiratory failure, PCP should be considered. When opportunistic pulmonary infection is diagnosed under special circumstances, one should be alert to the possibility of AIDS and examine serum antihuman immunodeficiency virus (HIV) antibody.