Vertical heterostructure of graphite-MoS2 for gas sensing.

2D materials, given their form-factor, high surface-to-volume ratio, and chemical functionality have immense use in sensor design. Engineering 2D heterostructures can result in robust combinations of desirable properties but sensor design methodologies require careful considerations about material properties and orientation to maximize sensor response. This study introduces a sensor approach that combines the excellent electrical transport and transduction properties of graphite film with chemical reactivity derived from the edge sites of semiconducting molybdenum disulfide (MoS2) through a two-step chemical vapour deposition method. The resulting vertical heterostructure shows potential for high-performance hybrid chemiresistors for gas sensing. This architecture offers active sensing edge sites across the MoS2 flakes. We detail the growth of vertically oriented MoS2 over a nanoscale graphite film (NGF) cross-section, enhancing the adsorption of analytes such as NO2, NH3, and water vapor. Raman spectroscopy, density functional theory calculations and scanning probe methods elucidate the influence of chemical doping by distinguishing the role of MoS2 edge sites relative to the basal plane. High-resolution imaging techniques confirm the controlled growth of highly crystalline hybrid structures. The MoS2/NGF hybrid structure exhibits exceptional chemiresistive responses at both room and elevated temperatures compared to bare graphitic layers. Quantitative analysis reveals that the sensitivity of this hybrid sensor surpasses other 2D material hybrids, particularly in parts per billion concentrations.

Proteinuria with fumaric acid ester treatment for psoriasis.

Fumaric acid esters (FAE) have been used in the treatment of psoriasis for many years. In general, they are regarded as relatively safe compared with other antipsoriatic systemic treatments, with the most notable adverse effects being gastrointestinal upset, lymphopenia and transient flushing. Renal toxicity has only rarely been reported, and was not found in two independent prospective trials nor in a large retrospective evaluation of almost 1000 patients treated for a median of 44 months. We report three patients developing reversible proteinuria during FAE treatment. One of these displayed the same pattern upon repeated drug administration, thereby clearly indicating FAE treatment to be the causal trigger. The presented cases highlight proteinuria as a clinical concern in FAE treatment. Furthermore, as the novel FAE agent dimethylfumaric (DMF) ester (contained in BG00012/Panaclar) has previously been shown to be effective in psoriasis in a phase III trial and not shown renal toxicity in a large trial for multiple sclerosis, the current report suggests that market introduction of DMF for psoriasis should be pursued.

Noninvasive recovery and detection of possum Trichosurus vulpecula DNA from bitten bait interference devices (WaxTags).

The brushtail possum is a major agricultural and ecological pest in New Zealand. A novel noninvasive DNA sampling tool for detecting its presence (WaxTags, or WT) was tested. DNA was recovered from saliva left on WT, and two lengths (407 bp and 648 bp) of the cytochrome c oxidase I (COI) barcoding region were amplified by polymerase chain reaction (PCR). PCR products were considered (+) when a DNA band was clearly visible by electrophoresis. Different factors that might affect PCR (+) were investigated with captive possums: (i) both extraction protocols of the QIAGEN DNeasy Blood and Tissue Kit, (ii) effect of an overnight or longer delay of up to 3 weeks before DNA extraction on both COI amplicons, and (iii) effect of the individual, order and magnitude of the bite. Extraction protocols were not significantly different. The effect of the overnight delay was not significant, and amplification of the short amplicon was significantly higher (100%) than for the long fragment (48%). After a two or 3-week delay, the short amplicon had 94% and 56% PCR (+), success rates, respectively. Individual, order and magnitude of a bite had no significant effect. The delay trial was repeated with WT from the wild, for which PCR (+) rate of the short amplicon was 63%, regardless of freshness. Four microsatellites were amplified from captive WT samples. We conclude that DNA from saliva traces can be recovered from WT, a potential new tool for noninvasive monitoring of possums and other wildlife.

Killed Mycobacterium vaccae suspension in children with moderate-to-severe atopic dermatitis: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: The hygiene hypothesis is often proposed to explain the high prevalence of atopy in the western world. Dysregulation of the immune system may result from inadequate exposure to micro-organisms such as mycobacteria. A small trial suggested that a killed extract of Mycobacterium vaccae ameliorates atopic dermatitis (AD). OBJECTIVES: To confirm in a large clinical trial whether killed M. vaccae ameliorates AD in 5-16-year-old children. METHODS: This was a randomized, placebo-controlled, double-blind, multi-centre study of the effect of intradermal injection of killed M. vaccae (0.1 or 1 mg) on patients, aged 5-16, with moderate-to-severe AD. Patients were followed up for 24 weeks. The primary end point was the change in severity of AD at 12 weeks, assessed using the six area, six-sign, atopic dermatitis (SASSAD) score. Secondary end points included changes in disease extent, patient's global assessment and children's dermatology life quality index. RESULTS: There were 166 patients randomized. The mean SASSAD score fell to a similar degree at week 12 in all treatment arms: from 33 to 24, (26%) in the high-dose group, from 30 to 23 (25%) in the low-dose group and from 36 to 27 (24%) in the placebo group (P>0.05). Secondary end points followed the same trend. Adverse events were generally those expected to occur in this population. Injection site reactions occurred in 32 patients at week 4. CONCLUSIONS: M. vaccae was no more effective than the placebo in ameliorating the severity of AD.

A practice-research model for collaborative partnership.

The ability to integrate education, practice and research initiatives is well documented and the nursing literature presents several collaborative models that have emerged between educational institutions and service agencies to achieve this aim. However, a collaborative partnership agreement does more than integrate these initiatives; it is a vehicle by which the theory-clinical practice gap is bridged and best practice outcomes are achieved. This paper outlines an innovative collaborative partnership agreement between Fremantle Hospital and Health Service and Curtin University of Technology in Perth, Western Australia. The partnership engages academics in the clinical setting in two formalised collaborative appointments. This partnership not only enhances communication between educational and health services, but fosters the development of nursing research and knowledge. The process of the collaborative partnership agreement involved the development of a Practice-Research Model (PRM) of collaboration. This model encourages a close working relationship between registered nurses and academics, and has also facilitated strong links at the health service with the Nursing Research and Evaluation Unit, medical staff and other allied health professionals. Links have also been established with other health services and agencies in the metropolitan area. The key concepts exemplified in the application of the model include practice-driven research development, collegial partnership, collaborative ownership and best practice. Many specific outcomes have been achieved through implementation of the model, but overall the partnership between registered nurses and academics in the pursuit of research to support clinical practice has been the highlight. This has resulted in changes and innovations in current nursing practice and, importantly, dissemination of best practice outcomes.

The reliability of three techniques for measuring foot position.

The reliability of three commonly used techniques for measuring foot position--valgus index, navicular height, and arch height--was evaluated in a study involving 20 healthy subjects. The results demonstrated significant differences (P < .05) between two observers for all three techniques, although there were no significant differences between two visits for the same observer (P < .05). Secondary analysis demonstrated that navicular height yielded the highest degree of intraobserver and interobserver agreement. The results suggest that there is a wide variation in foot position in the general population, and that measurement error may result from difficulties in defining foot position, techniques used, and instrumentation.

Emerging standardization in pharmacoeconomics.

In this study, we reviewed pharmacoeconomic guidelines from the United Kingdom, Spain, Italy, Australia, Canada, and the United States to determine areas of emerging standardization. We examined the published literature, publication guidelines of major health journals, and published and unpublished recommendations from various task forces and conferences on related topics. The review revealed several general principles for which there was consensus across guidelines. These common features included the importance of using and reporting transparent methods so that readers can easily understand what calculations are being performed on which data elements, minimizing bias, and providing justification for the methods and assumptions used. Differences were detected across guidelines on the following topics: type of pharmacoeconomic assessment, perspective, comparators and data sources, data analysis, cost analysis, future cost analysis, outcomes assessment, modeling, time horizon, discounting, disclosure, and generalizability. Evolution of economic guidelines hinges on whether the primary goal is to increase the consistency or increase the validity of economic assessments. Some balance between these two objectives is desirable.

Cloning and expression of a rat placental cDNA encoding a novel cathepsin L-related protein.

Cathepsin L is a major lysosomal cysteine protease produced by mouse placenta and fibroblasts. This study characterizes a novel cathepsin L-related mRNA expressed in rat placenta. Immunological and nucleotide screening of a rat placenta library identified six positive clones, the largest, pCLRP-9, being 924 base pairs in length. The combined sequences of all the clones contain an open reading frame of 711 nucleotides, a termination codon, a polyadenylation site, and 197 nucleotides of 3' untranslated region, but lack the 5' translation initiation codon. The pCLRP nucleotide sequence showed 60-64% identity to those of mouse, rat, and human cathepsin L. The deduced amino acid sequence of pCLRP codes for 237 amino acids, which align with the carboxy-terminal sequence of cathepsin L and has the active site residues characteristic of the cysteine protease family. Northern blot analysis showed hybridization of pCLRP with a major mRNA transcript of 1.3 kilobases expressed in placenta, but not kidney or liver. In contrast, a cDNA for mouse pro-cathepsin L hybridized with a transcript of 1.7 kilobases expressed in rat kidney, as well as placenta. During late gestation, steady-state levels of rat placental pCLRP mRNA were highest on day 18, whereas those of mouse procathepsin L were greatest on day 20 of gestation. Antiserum to mouse cathepsin L cross-reacted with four proteins of molecular weights 36,000 to 42,000 in rat placental culture medium, of which two were absent in the kidney. These data indicate that rat placenta expresses several species of cathepsin L-type proteins, which may be involved in placental function and nutrient supply.

Steroid-induced proteins secreted by the uterus of the guinea pig.

This study was conducted to identify proteins synthesized and secreted de novo by the guinea pig uterus. Uterine samples were obtained from cycling, late-pregnant as well as ovariectomized and steroid-treated guinea pigs and cultured with either L-[3H]leucine or L-[35S]methionine. Two-dimensional SDS-PAGE of culture medium followed by fluorography was used to determine proteins synthesized and secreted de novo during a 24-h incubation period. Two complexes of estradiol-stimulated proteins (ESP) were detected. Each complex was composed of 5-7 unique proteins with slightly different isoelectric points. The higher molecular-weight complex had a molecular weight of 65,000-60,000 and an isoelectric point range of 5.2-6.1. The lower molecular-weight complex had a molecular weight of 60,000-55,000 and a similar range of isoelectric points. The two complexes of ESP were not observed in medium of explants from animals that received placebos, were late-pregnant, or were treated with progesterone only. Progesterone administered in combination with estradiol enhanced production of both complexes of ESP to similar degrees. Neither complex of ESP was secreted by the explant culture in the presence of tunicamycin, suggesting that the proteins are glycosylated. These findings demonstrate that the uterus of the guinea pig produces two unique complexes of proteins in response to estradiol stimulation, and all results are consistent with the hypothesis that ESP are contained in the carbohydrate-rich secretory granules of endometrial gland cells.

Developmental expression of rat insulin-like growth factor binding protein-2 by astrocytic glial cells in culture.

Brain astrocytes were established in primary culture from postnatal and adult rats to characterize the developmental expression of secreted proteins. Astrocytes cultured from 21-day rat brain, but not 1-day rat brain, secreted a distinct group of proteins with Mr of 35,000 as determined by analysis of [35S]methionine-labeled proteins using two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. N-terminal amino acid sequence analysis of this protein group showed 100% identity to rat insulin-like growth factor binding protein-2 (rIGFBP-2), the BRL-3A IGFBP purified from a fetal rat liver cell line. An antiserum was generated against this astrocyte 35,000 Mr protein, and immunoblot analysis revealed a dramatic increase in rIGFBP-2 secretion in astrocytes cultured from 14-day, 21-day, and adult rat brain compared to astrocytes from 1-day and 7-day rat brain. Similar analysis of neonatal rat brain neurons in culture failed to show immunoreactive rIGFBP-2 in cell lysates or secreted protein. Ligand Western blot analysis demonstrated [125I]IGF-II binding to a single protein band which comigrated with a prominant rIGFBP-2 immunoreactive species in nonreduced conditioned medium from 21-day astrocytes. In comparison [125I]IGF-II binding proteins were detected only at low levels in medium from astrocytes cultured from 1-day rat brain and were undetectable in neuron-conditioned media. Northern blot analysis using a rIGFBP-2 complementary DNA revealed 5-fold greater messenger RNA levels in astrocytes from 21-day rat brain compared with astrocytes from 1-day brain, whereas neonate neurons showed no transcripts. Thus, rIGFBP-2 exhibits a pattern of developmental and cell-specific expression in cultured rat brain cells.

Angiotensin II induces secretion of plasminogen activator inhibitor 1 and a tissue metalloprotease inhibitor-related protein from rat brain astrocytes.

The present study investigates angiotensin (Ang) II effects on secretory protein synthesis in brain astrocytes cultured from neonatal and 21-day-old rats. Ang II-induced changes in the de novo synthesis of [35S]methionine-labeled secretory proteins were visualized using two-dimensional NaDodSO4/PAGE. Astrocytes from 21-day-old rat brain possess specific high-affinity receptors for Ang II. These cells express two Ang II-induced secretory proteins with Mr 55,000 (AISP-55K) and Mr 30,000 (AISP-30K), which were time- and dose-dependent (EC50, 1 nM). [Sar1, Ile8]Ang II (where Sar is sarcosine) inhibited Ang II-induced secretion of AISP-55K but not AISP-30K. N-terminal amino acid sequencing indicates that AISP-55K is identical to rat plasminogen activator inhibitor 1, whereas AISP-30K exhibits 72-81% identity to three closely related proteins: human tissue inhibitor of metalloproteases, a rat phorbol ester-induced protein, and the murine growth-responsive protein 16C8. Immunofluorescent staining with rat plasminogen activator inhibitor 1 antibody was induced in the majority of cells in culture after Ang II treatment of astrocytes from 21-day-old rat brains. Absence of this response to Ang II in astrocytes from neonatal rat brain provides evidence that this action of Ang II on astrocytes is developmentally regulated.

Human relaxin inhibits division but not differentiation of 3T3-L1 cells.

For the first time, we demonstrate here the ability of human relaxin to block cell division. During the induction of differentiation of 3T3-L1 fibroblasts to adipocytes, the cells typically undergo two rounds of cell division followed by accumulation of lipid droplets and expression of insulin-stimulated glucose transport as the cells attain the adipocyte phenotype. Human relaxin added during induction had no effect on the development of the adipocyte phenotype or insulin-stimulated glucose transport. However, it blocked cell division at a half-maximal concentration of 1.25 nM, well within physiological range. This could be reversed by the addition of antibodies specific for human relaxin. Thus relaxin joins a select number of hormones with growth inhibitory properties such as transforming growth factor-beta (TGF beta) and mammastatin. Potentially, this is an important but until now unidentified function of relaxin. Unlike other inhibitory polypeptides, like TGF beta, relaxin does not prevent differentiation but rather uncouples it from cell division.

Identification of a novel family of growth hormone-related proteins secreted by rat placenta.

Mid-to-late gestation rat placenta synthesizes a number of proteins related to prolactin, including rat placental lactogen II (rPL-II), rat prolactin-like protein A (rPLP-A) and rat prolactin-like protein B (rPLP-B). This study identifies a new family of proteins synthesized and secreted by gestation day 15 placental explants which exhibit amino acid homology to growth hormone precursors from several species. Placental explant medium was fractionated by ammonium sulfate precipitation and analyzed by two-dimensional SDS-polyacrylamide gel electrophoresis to isolate four distinct proteins with Mr values of 28,000, 23,000, 25,000 and 30,000 and pI values of 5.7, 5.7, 5.4 and 5.3, respectively. These proteins represent a major fraction of secretory proteins with Mr in the 20,000 to 30,000 range. Immunoblot analysis showed that none of the four proteins crossreacted with antipeptide antisera against rPL-II, rPLP-A, or rPLP-B. These proteins were electrophoretically transferred from two-dimensional SDS-polyacrylamide gels onto an Immobilon PVDF membrane and N-terminal amino acid microsequencing carried out with a gas phase sequencer. N-terminal sequences of 45, 37, 37 and 32 amino acid residues were identified for proteins 1, 2, 3 and 4, respectively. The four proteins exhibit 76% to 97% homology. Computer analysis further revealed a 28% identity in a 32 amino acid overlap which begins at residue 14 of the 28,000 Mr protein (protein 1) and at residue 31 of growth hormone precursors of rat, mouse and human. The 32 amino acid overlap is 78% homologous if conservative amino acid replacements are included.

De novo synthesis and secretion of prolactin-like protein-B by rat placental explants.

Mid- to late-gestation rat placenta expresses three PRL-related mRNAs, rat placental lactogen-II (rPL-II), rat PRL-like protein-A (rPLP-A), and rat PRL-like protein-B (rPLP-B). The protein product of rPL-II mRNA has been characterized, and the protein products of the rPLP-A mRNA were recently identified. The mol wt of a nonsecreted nonglycosylated rPLP-B protein would be 27,145 based on the mRNA sequence. The present study is the first to report the identification of the rPLP-B protein. Antiserum was generated against a chemically synthesized oligopeptide inferred from a specific region of the rPLP-B cDNA. Three or four distinct proteins synthesized and secreted by rat basal zone explants (day 15 gestation) showed cross-reactivity with the rPLP-B antiserum. The relative mol wt of these immunoreactive proteins is approximately 30,000, with a pI varying from 6.1-6.6. De novo synthesized rPLP-B proteins were not secreted by the explant tissue in the presence of tunicamycin, suggesting that the proteins are glycosylated. These data are consistent with the presence of one potential N-glycosylation site derived from the rPLP-B mRNA sequence. The rPLP-B antiserum showed no cross-reactivity with proteins identified using antisera against rPLP-A, rPL-II, or human pregnancy-specific beta 1-glycoprotein. Immunocytochemical studies were carried out using paraffin sections from placentas of day 14 and 17 pregnant rats which were treated with anti-rPLP-B, followed by avidin-biotin-peroxidase complex. These experiments show perinuclear staining, which was localized in basophilic cytotrophoblast cells, confirming previous in situ mRNA hybridization studies. Although no physiological role has been established for rPLP-B, the synthesis and secretion of this protein by cells in contact only with maternal circulation suggest a hormonal role.

Benzo(a)pyrene inhibits epidermal growth factor binding and receptor autophosphorylation in human placental cell cultures.

Studies investigated the effects of benzo(a)pyrene (BP) treatment on epidermal growth factor (EGF) receptor binding and kinase activity in human placental cell cultures. Specific binding of 125I-EGF to cells from early gestation placentae was significantly decreased by 37 and 60% following exposure to 1 and 10 microM BP, respectively, for 24 hr. In contrast, cells cultured from term placentae showed no inhibitory effect of either concentration of BP. Specific binding of 125I-labeled insulin and insulin-like growth factors-I and -II to early gestation cells was decreased only 15-18% at 10 microM BP, which indicates that loss of membrane receptors appears to be selective for EGF. Scatchard analysis of early gestation cells revealed that BP was associated with a dose-dependent loss in the number of high affinity EGF binding sites. Evidence from cross-linking and autophosphorylation experiments confirmed that the Mr 170,000 binding protein was decreased in a dose-dependent manner following BP treatment. In comparison, term placental cells exhibit a 26% loss of EGF receptor autophosphorylation without alteration in binding following exposure to 10 microM BP. Thus, early gestation cells exhibit a BP-related down-regulation of EGF receptors, whereas term placental cells show receptor desensitization. No adverse effect of BP treatment was observed on the incorporation of [35S] methionine into proteins secreted by early gestation cells. Further experiments compared the effects of BP with the related poly-cyclic compounds beta-naphthoflavone, alpha-naphthoflavone, and 3-methylcholanthrene. In early gestation cells, EGF binding and receptor autophosphorylation were measurably decreased at 10 microM concentrations of these polycyclic compounds, but to a lesser extent than observed with BP. In term placental cells, however, EGF binding was unchanged or increased, whereas receptor autophosphorylation was decreased 10-26%. Thus, exposure of term placental cells to these polycyclic compounds leads to a dissociation between EGF binding and receptor protein kinase activity. Finally, aryl hydrocarbon hydroxylase activity was induced 20- to 200-fold in early placental cells exposed to BP, beta-naphthoflavone, and 3-methylcholanthrene. In summary, the direct effects of BP and related compounds observed on placental EGF receptors may indicate altered function of EGF in the regulation of cell growth and differentiation in the human placenta.

Pregnancy-specific beta 1-glycoprotein messenger ribonucleic acid and immunoreactive protein in the rat testis.

Human pregnancy-specific beta 1-glycoprotein (PS beta G) is synthesized in large quantities by syncytiotrophoblasts of the placenta. Recent studies using a partial cDNA of PS beta G isolated from human term placenta detected the presence of mRNA highly homologous to placental PS beta G in a number of extraplacental tissues, including human and rat testis. The present study determined in the rat that the amount of PS beta G mRNA based on percentage of total tissue RNA was greatest in the testis of mature rats, followed by senescent and prepubertal rats. In experiments using rats with testicular feminization syndrome (Tfm) which exhibit end-organ insensitivity to androgen stimulation, slot blot analysis of testicular RNA showed reduced levels of PS beta G mRNA in Tfm rats compared to normal rats. Northern blot analysis of rat testicular RNA probed with a human placental PS beta G cDNA demonstrated the presence of a single mRNA species of 1.65 kilobases. Subsequent studies investigated whether proteins immunologically similar to PS beta G were present in the testes from normal and Tfm rats. The rat testes were perfused with fixative, and sections from paraffin-embedded tissues were treated with rabbit anti-human PS beta G, followed by the avidin-biotin-peroxidase complex. Testes from the normal rat showed intense immunostaining in late spermatids (steps 16, 17, 18, and 19 of spermiogenesis), residual bodies, as well as cytoplasm of Leydig cells. Spermatozoa within the epididymis also demonstrated intense immunolabeling. Paraffin sections of the testes from the Tfm rat showed light diffuse cytoplasmic immunostaining in cells of the seminiferous tubules. Since spermiogenesis does not proceed normally, and no spermatids were seen, it was not possible to accurately stage the seminiferous tubules of the Tfm rat. The Leydig cells of the Tfm testes stained intensely, however, as was observed in the testes of the normal rat. These data suggest that the rat may provide an animal model for the investigation of the biological function and regulation of PS beta G in the testis.

Identification of proteins immunochemically related to human pregnancy-specific beta 1-glycoprotein in the rat placenta.

Human pregnancy-specific beta 1-glycoprotein (hPS beta G) consists of a set of glycoproteins present in placenta and maternal serum. This study characterized proteins in rat placenta that show immunological cross-reactivity with antisera to hPS beta G. Immunocytochemical studies using two independent preparations of anti-hPS beta G showed intense specific staining within basophilic cytotrophoblast cells of the basal zone of the gestation day 15 rat placenta. In contrast, basophilic cytotrophoblasts located in the labyrinth did not stain. Subsequent experiments used gel electrophoresis and immunoblot analysis to compare PS beta G in human placenta and serum with immunoreactive proteins in rat placenta and serum. A set of two or three proteins was detected in human villous tissue and pregnancy serum with apparent mol wt (Mr) ranging from 54,000-76,000. In contrast rat placenta showed a major immunoreactive protein with 120,000 Mr, while rat serum contained bands of 48,000 64,000 and 69,000 Mr. Explant cultures of rat basal zone tissue secreted two [35S]methionine-labeled proteins that were immunoreactive, a major 120,000 Mr species and a minor 76,000 Mr form, with pI values of 4.6-5.5; tunicamycin inhibited the secretion of both species. Thus, a 120,000 Mr glycoprotein appears to be the major tissue and secreted form of rat PS beta G analog in day 15 placenta. Finally, the cytochemical localization of PS beta G-like proteins in rat placenta showed a progressive gestational shift from giant trophoblast cells in the parietal yolk sac placenta on day 12 to the basal zone cytotrophoblast cells by day 15. Data indicate that the pregnant rat may provide an animal model for investigation of the biological function of PS beta G during late gestation.