Ghrelin is present in teeth

Ghrelin belongs to the family of a gut-brain hormone that promotes food intake and controls energy balance. Recently, it has also been shown to regulate bone formation directly. Dental tissue shares several functional, developmental and anatomical similarities with bone, and in the present study we have investigated the presence of ghrelin in 44 human teeth using immunocytochemistry and radioimmunoassay. Both methods showed that the hormone is present in canines and molars, mainly in the odontoblasts but also in the pulp. Ghrelin could potentially play interesting physiological roles in teeth.     

Trichlorfon predisposes to aneuploidy and interferes with spindle formation in in vitro maturing mouse oocytes

The pesticide trichlorfon (TCF) has been implicated in human trisomy 21, and in errors in chromosome segregation at male meiosis II in the mouse. We previously provided evidence that TCF interferes with spindle integrity and cell-cycle control during murine oogenesis. To assess the aneugenic activity of TCF in oogenesis, we presently analysed maturation, spindle assembly, and chromosome constitution in mouse oocytes maturing in vitro in the presence of 50 or 100 microg/ml TCF for 16 h or in pulse-chase experiments. TCF stimulated maturation to meiosis II at 50 microg/ml, but arrested meiosis in some oocytes at 100 microg/ml. TCF at 100 microg/ml was aneugenic causing non-disjunction of homologous chromosomes at meiosis I, a significant increase of the hyperploidy rate at metaphase II, and a significant rise in the numbers of oocytes that contained a 'diploid' set of metaphase II chromosomes (dyads). TCF elevated the rate of precocious chromatid segregation (predivision) at 50 and 100 microg/ml. Pulse-chase experiments with 100 microg/ml TCF present during the first 7 h or the last 9 h of maturation in vitro did not affect meiotic progression and induced intermediate levels of hyperploidy at metaphase II. Exposure to > or =50 microg/ml TCF throughout maturation in vitro induced severe spindle aberrations at metaphase II, and over one-third of the oocytes failed to align all chromosomes at the spindle equator (congression failure). These observations suggest that exposure to high concentrations of TCF induces non-disjunction at meiosis I of oogenesis, while lower doses may preferentially cause errors in chromosome segregation at meiosis II due to disturbances in spindle function, and chromosome congression as well as precocious separation of chromatids prior to anaphase II. The data support evidence from other studies that TCF has to be regarded as a germ cell aneugen.     

The bioactive peptides salusins and apelin-36 are produced in human arterial and venous tissues and the changes of their levels during cardiopulmonary bypass

This study aimed to examine the effects of CPB on salusin-α, salusin-β and apelin-36 bioactive peptides in people who are planned to undergo coronary artery bypass graft (CABG) operation due to coronary artery disease and to explore whether these peptides are produced in human aortic, saphenous and arterial tissues. The study included age and BMI matched 15 patients who underwent CABG operation by CPB. In order to determine salusin-α, salusin-β and apelin-36 levels, venous blood samples were collected before induction of anesthesia (T1), before CPB (T2), 5min before the removal of cross-clamp (T3), 5min after the removal of cross-clamp (T4), upon arrival in the intensive care (T5), at postoperative 24th hour (T6) and 72nd hour (T7). Salusin and apelin expressions of the tissues were shown by immunohistochemical method. Peptide amounts of sera and tissues were measured using ELISA. Salusins production by vessels occurs in fibroblast cells of the media in the aorta and smooth muscle cells of the media in the LIMA and saphena. Apelin is produced by endothelial cells of the intima and fibroblast cells of the media in the aorta and by smooth muscle cells of the media in the LIMA and saphena. Changes in the levels of salusin-β and apelin-36 were significant during CPB. Salusin-α, salusin-β and apelin-36 are locally synthesized in the arteries and veins. Salusins and apelin-36 might be important markers in the CPB, and also that salusin-β was more specific in comparison to salusin-α.     

Fracture resistance and analysis of stress distribution of implant-supported single zirconium ceramic coping combination with abutments made of different materials

The purpose of this study was to compare the fracture resistance and fracture mode of single implant-zirconium coping combinations using zirconium and titanium abutments and to analyze the stress distribution pattern using three-dimensional finite elements analysis. Twenty implants with titanium and zirconium abutments were randomly divided into two groups (n = 10) and into resin blocks. Zirconium copings were cemented onto the abutments. The specimens were loaded with 135° angles to the long axis and the load values at the moment of failure were recorded using a universal test machine. Stress levels were calculated according to the maximum Von Mises criteria. The fracture resistances for titanium and zirconium abutment groups were 525.65 N and 514.05 N, respectively. No significant differences were observed between two groups regarding the fracture resistance levels. The maximum Von Mises equivalent stress concentrated on zirconium copings in both of the groups. Implant-abutment-ZrO2 coping combination has the potential to withstand physiological occlusal forces in the anterior region. Three-dimensional finite elements analysis results of the implant-abutment-ZrO2 coping combination is compatible with the results of fracture resistance.     

Timeliness of Clinic Attendance Is a Good Predictor of Virological Response and Resistance to Antiretroviral Drugs in HIV-Infected Patients

Background

Ensuring long-term adherence to therapy is essential for the success of HIV treatment. As access to viral load monitoring and genotyping is poor in resource-limited settings, a simple tool to monitor adherence is needed. We assessed the relationship between an indicator based on timeliness of clinic attendance and virological response and HIV drug resistance.

Methods

Data from 7 virological cross-sectional studies were pooled. An adherence indicator was calculated as the number of appointments attended with delay divided by the number of months between antiretroviral treatment (ART) initiation and date of virological testing and multiplying this by 100. Delays of 1 or more to 5 or more days were considered in turn. Multivariate random-intercept logistic regression was fitted to examine the effect on outcomes, separately for adults and children.

Results

A total of 3580 adults and 253 children were included. Adults were followed for a median of 26.0 months (IQR 12.8-45.0) and attended a median of 24 visits (IQR 13–34). The 1-day delay adherence indicator was strongly associated with viral load suppression (OR 0.96, 95% CI 0.95–0.97 per unit increase), virological failure (OR 1.05, 95% CI 1.03–1.06) and HIV drug resistance (OR 1.03, 95% CI 1.01–1.05) after adjusting for initial age and CD4 count, previous ART experience, type of regimen and Tuberculosis diagnosis at start of therapy. Similar results were observed in children.

Conclusion

An adherence indicator based on timeliness of clinic attendance predicts strongly both virological response and drug resistance, and could help to timely identify non-adherent patients in settings where viral load monitoring is not available.     

Exposure of mouse oocytes to bisphenol A causes meiotic arrest but not aneuploidy

Mouse oocytes isolated from large antral follicles were exposed to a wide range of concentrations of bisphenol A (BPA) during maturation in vitro (50 ng/ml to 10 microg/ml BPA in medium). Exposure to high concentrations of BPA (10 microg/ml) affected spindle formation, distribution of pericentriolar material and chromosome alignment on the spindle (termed congression failure), and caused a significant meiotic arrest. However, BPA did not increase hyperploidy at meiosis II at any tested concentration. Some but not all meiosis I arrested oocytes had MAD2-positive foci at centromeres of chromosomes in bivalents, suggesting that they had failed to pass the spindle checkpoint control. In a second set of experiments prepubertal mice were exposed sub-chronically for 7 days to low BPA by daily oral administration, followed by in vitro maturation of the denuded oocytes to metaphase II in the absence of BPA, as this treatment protocol was previously reported to induce chromosome congression failure and therefore suspected to cause aneuploidy in oocytes. The sub-chronic exposure subtly affected spindle morphology and oocyte maturation. However, as with the exposure in vitro, there was no evidence that low BPA doses increased hyperploidy at meiosis II. In conclusion, the data suggest that mouse oocytes from mice respond to BPA-induced disturbances in spindle formation by induction of meiotic arrest. This response might result from an effective checkpoint mechanism preventing the occurrence of chromosome malsegregation and aneuploidy. Low chronic BPA exposure in vivo as such does not appear to pose a risk for induction of errors in chromosome segregation at first meiosis in mouse oocytes. Additional factors besides BPA may have caused the high rate of congression failure and the temporary increase in hyperploidy in mouse metaphase II oocytes reported previously.     

Association of obesity with rs1421085 and rs9939609 polymorphisms of FTO gene

The aim of this study is to investigate the genetic influence of polymorphisms in fat mass and obesity associated (FTO) gene on a sample of obese subjects and controls. Obesity is an epidemic all over the world. Several polymorphisms in the first intron of FTO gene have been associated with common forms of human obesity. In this research rs1421085 and rs9939609 polymorphisms of FTO gene were genotyped in 190 obese patients with a BMI ≥30 kg/m² (Body Mass Index) and 97 healthy controls with a BMI of 18.5–24.9. Genotyping of SNPs was performed by real-time polymerase chain reaction. Body composition was established with bioelectric impedance analysis. Waist-to-hip ratio was determined for all participants. There were no significant differences (P > 0.05) between obese cases and controls in terms of genotype frequencies of rs1421085 and rs9939609 polymorphisms in our study. Also there were no significant correlations between genotypes and obesity related (anthropometric-body composition) parameters (P > 0.05).     

Alcohol biosensing by polyamidoamine (PAMAM)/cysteamine/alcohol oxidase‐modified gold electrode

A highly stable and sensitive amperometric alcohol biosensor was developed by immobilizing alcohol oxidase (AOX) through Polyamidoamine (PAMAM) dendrimers on a cysteamine‐modified gold electrode surface. Ethanol determination is based on the consumption of dissolved oxygen content due to the enzymatic reaction. The decrease in oxygen level was monitored at ?0.7 V vs. Ag/AgCl and correlated with ethanol concentration. Optimization of variables affecting the system was performed. The optimized ethanol biosensor showed a wide linearity from 0.025 to 1.0 mM with 100 s response time and detection limit of (LOD) 0.016 mM. In the characterization studies, besides linearity some parameters such as operational and storage stability, reproducibility, repeatability, and substrate specificity were studied in detail. Stability studies showed a good preservation of the bioanalytical properties of the sensor, 67% of its initial sensitivity was kept after 1 month storage at 4°C. The analytical characteristics of the system were also evaluated for alcohol determination in flow injection analysis (FIA) mode. Finally, proposed biosensor was applied for ethanol analysis in various alcoholic beverage as well as offline monitoring of alcohol production through the yeast cultivation. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010     

Cost-effectiveness of primary prophylaxis of AIDS associated cryptococcosis in Cambodia

Background

Cryptococcal infection is a frequent cause of mortality in Cambodian HIV-infected patients with CD4+ count ≤100 cells/µl. This study assessed the cost-effectiveness of three strategies for cryptococcosis prevention in HIV-infected patients.

Methods

A Markov decision tree was used to compare the following strategies at the time of HIV diagnosis: no intervention, one time systematic serum cryptococcal antigen (CRAG) screening and treatment of positive patients, and systematic primary prophylaxis with fluconazole. The trajectory of a hypothetical cohort of HIV-infected patients with CD4+ count ≤100 cells/µl initiating care was simulated over a 1-year period (cotrimoxazole initiation at enrollment; antiretroviral therapy within 3 months). Natural history and cost data (US$ 2009) were from Cambodia. Efficacy data were from international literature.

Results

In a population in which 81% of patients had a CD4+ count ≤50 cells/ µl and 19% a CD4+ count between 51–100 cells/µl, the proportion alive 1 year after enrolment was 61% (cost $ 472) with no intervention, 70% (cost $ 483) with screening, and 72% (cost $ 492) with prophylaxis. After one year of follow-up, the cost-effectiveness of screening vs. no intervention was US$ 180/life year gained (LYG). The cost-effectiveness of prophylaxis vs. screening was $ 511/LYG. The cost-effectiveness of prophylaxis vs. screening was estimated at $1538/LYG if the proportion of patients with CD4+ count ≤50 cells/µl decreased by 75%.

Conclusion

In a high endemic area of cryptococcosis and HIV infection, serum CRAG screening and prophylaxis are two cost effective strategies to prevent AIDS associated cryptococcosis in patients with CD4+ count ≤100 cells/µl, at a short-term horizon, screening being more cost-effective but less effective than prophylaxis. Systematic primary prophylaxis may be preferred in patients with CD4+ below 50 cells/µl while systematic serum CRAG screening for early targeted treatment may be preferred in patients with CD4+ between 51–100 cells/µl.