Studies of insulin release and rat pancreatic islet metabolism with diastereomers of D-glucose

Studies of insulin release with diastereomers and other analogues of D-glucose demonstrated that only sugars which undergo oxidation to CO₂ stimulate insulin release by the pancreatic islet. None of the non-metabolizable diastereomers of glucose stimulated insulin release in the presence of a substimulatory concentration of glucose for fuel. Although 5.5 mM glucose formed 77% as much CO₂ as 16.7 mM mannose and twice that of 16.7 mM fructose, 5.5 mM glucose did not stimulate insulin release whereas 16.7 mM mannose and fructose did stimulate insulin release. These results indicate that the important stimulus for glucose-induced insulin release involves metabolism of glucose, but that the stimulus does not involve solely a fuel function of glucose.     

Label-free, multiplexed detection of bacterial tmRNA using silicon photonic microring resonators

This work describes the development of an automated flow-based biosensor that employs genetically modified acetylcholinesterase (AChE) enzymes B394, B4 and wild type B131. The biosensor was based on a screen printed carbon electrode (SPE) that was integrated into a flow cell. Enzymes were immobilised on cobalt (II) phthalocyanine (CoPC) modified electrodes by entrapment in a photocrosslinkable polymer (PVA-AWP). The automated flow-based biosensor was successfully used to quantify three organophosphate pesticides (OPs) in milk samples. The OPs used were chlorpyriphos-oxon (CPO), ethyl paraoxon (EPOx) and malaoxon (MOx). The total analysis time for the assay was less than 15 min. Initially, the biosensor performance was tested in phosphate buffer solution (PBS) using B394, B131 and B4 biosensors. The best detection limits were obtained with B394; therefore, this biosensor was used to produce calibration data in milk with three OPs in the concentration range of 5 × 10(-6)M to 5 × 10(-12)M. The limit of detection (LOD) obtained in milk for CPO, EPOx and MOx were 5 × 10(-12)M, 5 × 10(-9)M and 5 × 10(-10)M, respectively, with a correlation coefficient R(2)=0.9910. The automated flow-based biosensor successfully quantified the OPs in different fat-containing milk samples. There were no false positives or false negatives observed for the analytical figures of merit for the constructed biosensors. This method is inexpensive, sensitive, portable, non-invasive and provides real-time results. This analytical system can provide rapid detection of highly toxic OPs in food matrices such as milk.     

Patients and borders, money and mission: responding to medically needy persons from other countries who lack financial resources

When financially impoverished persons from resource-poor countries travel to resource-rich countries to seek medical treatment, health-care professionals and hospital administrators must decide how to respond. These financially impoverished "medical travelers" are medically no different from financially impoverished citizens or immigrants, but their national residence and purpose of travel may cause them to be seen as having a lower degree of standing within the communities that hospitals are expected to serve. In responding to such persons, health-care professionals and administrators encounter tension between the mission-driven intention to provide care and a budget-driven intention to protect operating margins. Responses require practical wisdom and a readiness to wrestle with tensions related to objectives (charitable versus financial), role-specific obligations (clinicians versus administrators), and contrasting moral frameworks. There are also challenges of reconciling plural moral values, setting moral priorities, and considering whether national borders should constrain our view of persons as neighbors. Finding a way forward amidst many tensions is hard moral work, but it may be facilitated by granting a moral imperative to physical proximity, respecting role-fidelity among clinicians and administrators, furthering candid moral dialogue, and promoting a presumption to treat whenever it is feasible to do so.     

Detection of tmRNA molecules on microarrays at low temperatures using helper oligonucleotides

Background  

The hybridization of synthetic Streptococcus pneumoniae tmRNA on a detection microarray is slow at 34°C resulting in low signal intensities.     

Expression of Metalloproteinase 2 in the Cell Response to Porous Demineralized Bovine Bone Matrix

Summary The purpose of the study was to analyze the involvement of metalloproteinase 2 (MMP-2) and macrophages in the tissue and cell response to the organic graft material produced from bovine cancellous bone. Thirty adult male white Wistar rats (Rattus norvegicus) received implants of blocks of demineralized bovine bone matrix between the fasciae of the quadriceps muscle. The specimens collected at 3, 7, 14, 21 and 28 days after implantation (n = 6/period). Sections of 6 μm thick were stained with hematoxylin and eosin and immunolabeled with anti-MMP-2 and anti-CD68 using standard avidin–biotin–peroxidase method. The tissue response to the material was initially mediated by polymorphonuclear neutrophils, evolving to a mononuclear inflammatory infiltrate with macrophages and few lymphocytes and plasma cells and presence of inflammatory multinucleated giant cells (GC) in contact with the material that exhibited signs of resorption. The number of cells immunolabeled to MMP-2 was highest at day 7 (103.2 ± 39.1), but significantly decreased (F = 3.67; p = 0.044) until day 28 (45.9 ± 13.1). CD68 immunostaining also significantly decreased (F = 6.75; p = 0.007) from day 7 (49.5 ± 10.4) to day 28 (19.5 ± 8.9). A positive and statistically significant correlation was observed between the evolutions of these two variables. The material had been almost completely resorbed at day 28. Among cells present at the granuloma, anti-MMP-2 immunostaining was predominant and more intense in macrophages, yet lightly immunolabeled multinucleated giant cells were found in close contact with the material. Thus, considering the experimental limitations of this study, we concluded that MMP-2 produced by macrophages participates in the resorption of demineralized bovine bone.     

Cytokine Quantification in the Supernatant of Mononuclear Cell Cultures and in Blood Serum from Patients with Jorge Lobo's Disease

Few studies are available about the participation of the immune response in the control or the development of Jorge Lobo's disease. Thus, the objective of the present study was to quantify macrophage and lymphocyte cytokines in the supernatant of cell cultures and in blood serum from patients with this disease. The study was conducted on 15 patients with the mycosis and on 15 healthy adult individuals (control group). Blood samples were collected in order to obtain serum and mononuclear cells. Monocytes were cultured for 24 h in the presence or absence of LPS and L. loboi, and lymphocytes were cultured for 48 h in the presence or absence of PHA and L. loboi. Cytokines IL-1beta, TNF-alpha and IL-6 were quantified by ELISA in the supernatants of monocyte cultures and in serum. Cytokines IL-2, IFN-gamma, IL-4 and IL-10 were quantified by FLISA in the supernatants of lymphocyte cultures and in serum. The quantification of the cytokines in the culture supernatant revealed a greater IL-4 and IL-6 production and lower IL-2 levels in patients compared to control. The production of IL-1beta, TNF-alpha, IL-10 and INF-gamma was similar in patients and controls. The mononuclear cells from patients with the non-localized form of the disease produced higher INF-gamma levels than those of patients with the localized form. The results suggest that patients with Jorge Lobo's disease show altered cytokine profiles represented by a predominance of the Th2 profile. However, further studies are needed to assess the participation of cytokines in the cell-fungus interaction in situ.     

MultiPLX: automatic grouping and evaluation of PCR primers

SUMMARY: MultiPLX is a new program for automatic grouping of PCR primers. It can use many different parameters to estimate the compatibility of primers, such as primer-primer interactions, primer-product interactions, difference in melting temperatures, difference in product length and the risk of generating alternative products from the template. A unique feature of the MultiPLX is the ability to perform automatic grouping of large number (thousands) of primer pairs. AVAILABILITY: Binaries for Windows, Linux and Solaris are available from http://bioinfo.ebc.ee/download/. A graphical version with limited capabilities can be used through a web interface at http://bioinfo.ebc.ee/multiplx/. The source code of the program is available on request for academic users. CONTACT: maido.remm@ut.ee.