Statistical-learning method for predicting hydrodynamic drag, lift, and pitching torque on spheroidal particles.

A statistical learning approach is presented to predict the dependency of steady hydrodynamic interactions of thin oblate spheroidal particles on particle orientation and Reynolds number. The conventional empirical correlations that approximate such dependencies are replaced by a neural-network-based correlation which can provide accurate predictions for high-dimensional input spaces occurring in flows with nonspherical particles. By performing resolved simulations of steady uniform flow at 1≤Re≤120 around a 1:10 spheroidal body, a database consisting of Reynolds number- and orientation-dependent drag, lift, and pitching torque acting on the particle is collected. A multilayer perceptron is trained and validated with the generated database. The performance of the neural network is tested in a point-particle simulation of the buoyancy-driven motion of a 1:10 disk. Our statistical approach outperforms existing empirical correlations in terms of accuracy. The agreement between the numerical results and the experimental observations prove the potential of the method.

Granulocytic myeloid-derived suppressor cells (GR-MDSC) accumulate in cord blood of preterm infants and remain elevated during the neonatal period.

Preterm delivery is the leading cause of perinatal morbidity and mortality. Among the most important complications in preterm infants are peri- or postnatal infections. Myeloid-derived suppressor cells (MDSC) are myeloid cells with suppressive activity on other immune cells. Emerging evidence suggests that granulocytic MDSC (GR-MDSC) play a pivotal role in mediating maternal-fetal tolerance. The role of MDSC for postnatal immune-regulation in neonates is incompletely understood. Until the present time, nothing was known about expression of MDSC in preterm infants. In the present pilot study, we quantified GR-MDSC counts in cord blood and peripheral blood of preterm infants born between 23 + 0 and 36 + 6 weeks of gestation (WOG) during the first 3 months of life and analysed the effect of perinatal infections. We show that GR-MDSC are increased in cord blood independent of gestational age and remain elevated in peripheral blood of preterm infants during the neonatal period. After day 28 they drop to nearly adult levels. In case of perinatal or postnatal infection, GR-MDSC accumulate further and correlate with inflammatory markers C-reactive protein (CRP) and white blood cell counts (WBC). Our results point towards a role of GR-MDSC for immune-regulation in preterm infants and render them as a potential target for cell-based therapy of infections in these patients.

Risk Compensation Following Medical Male Circumcision: Results from a 1-Year Prospective Cohort Study of Young School-Going Men in KwaZulu-Natal, South Africa.

PURPOSE: This study sought to assess risk compensation following voluntary medical male circumcision of young school-going men. Risk compensation is defined as an inadvertent increase in sexual risk behaviors and a corresponding decrease in self-perceived risk for contracting HIV following the application of a risk reduction technology. METHODS: This study documented the sexual practices of circumcised (n = 485) and uncircumcised (n = 496) young men in 42 secondary schools at three time points (baseline and 6 and 12 months) in a sub-district of KwaZulu-Natal, South Africa. Study participants were aged from 16 to 24 years old. RESULTS: At the end of the study period, there was no significant difference between the two cohorts concerning learners' perceptions of being at risk of contracting HIV (interaction effect: b = -0.12, p = 0.40). There was also no significant difference in the number of sexual partners in the previous month (interaction effect: b = -0.23, p = 0.15). The proportion of learners who have never used a condom decreased significantly over time (time effect: b = -0.27, p = 0.01), and there was no difference between the circumcised and uncircumcised learners (interaction effect: b = -0.09, p = 0.91). CONCLUSIONS: Risk compensation, as evidenced in this study over a 1-year period, was not associated with undergoing voluntary medical male circumcision (VMMC) in our sample of young school-going men. However, it is of concern that at the end of this study, less than half of the sexually active sample in a high-HIV-prevalence community used condoms consistently in the previous month (39% for both study cohorts). The latter underscores the need to view VMMC as a potential entry point for planned HIV and sexuality education interventions targeting young men in this community.

The effect of a dietary portfolio compared to a DASH-type diet on blood pressure.

BACKGROUND AND AIM: Compared to a DASH-type diet, an intensively applied dietary portfolio reduced diastolic blood pressure at 24 weeks as a secondary outcome in a previous study. Due to the importance of strategies to reduce blood pressure, we performed an exploratory analysis pooling data from intensively and routinely applied portfolio treatments from the same study to assess the effect over time on systolic, diastolic and mean arterial pressure (MAP), and the relation to sodium (Na(+)), potassium (K(+)), and portfolio components. METHODS AND RESULTS: 241 participants with hyperlipidemia, from four academic centers across Canada were randomized and completed either a DASH-type diet (control n = 82) or a dietary portfolio that included, soy protein, viscous fibers and nuts (n = 159) for 24 weeks. Fasting measures and 7-day food records were obtained at weeks 0, 12 and 24, with 24-h urines at weeks 0 and 24. The dietary portfolio reduced systolic, diastolic and mean arterial blood pressure compared to the control by 2.1 mm Hg (95% CI, 4.2 to -0.1 mm Hg) (p = 0.056), 1.8 mm Hg (CI, 3.2 to 0.4 mm Hg) (p = 0.013) and 1.9 mm Hg (CI, 3.4 to 0.4 mm Hg) (p = 0.015), respectively. Blood pressure reductions were small at 12 weeks and only reached significance at 24 weeks. Nuts, soy and viscous fiber all related negatively to change in mean arterial pressure (ρ = -0.15 to -0.17, p ≤ 0.016) as did urinary potassium (ρ = -0.25, p = 0.001), while the Na(+)/K(+) ratio was positively associated (ρ = 0.20, p = 0.010). CONCLUSIONS: Consumption of a cholesterol-lowering dietary portfolio also decreased blood pressure by comparison with a healthy DASH-type diet. CLINICAL TRIAL REG. NO.: NCT00438425, clinicaltrials.gov.

The need for multipurpose prevention technologies in sub-Saharan Africa.

Women bear a disproportionate burden of the HIV epidemic in sub-Saharan Africa and account for about 60% of all adults living with HIV in that region. Young women, including adolescent girls, unable to negotiate mutual faithfulness and/or condom use with their male partners are particularly vulnerable. In addition to the high HIV burden, women in Africa also experience high rates of other sexually transmitted infections and unwanted pregnancies. The development of technologies that can simultaneously meet these multiple sexual reproductive health needs would therefore be extremely beneficial in the African setting.

Influence of Mifepristone in Induction Time for Terminations in the Second and Third Trimester.

Termination of pregnancy after the first trimester is generally carried out by medical induction. Question: The aim of this study is to investigate the effect of mifepristone before administration of the prostaglandin derivative on induction time. Material and Methods: We analysed 333 medically indicated terminations after the first trimester under the terms of § 218 a Para. 2 of the German Criminal Code, in which the prostaglandin derivatives misoprostol, gemeprost or dinoprostone were administered with or without pre-treatment with 600 mg of mifepristone. The time interval between the initial administration of prostaglandin and delivery was investigated. Using uni- and multivariate regression analysis, the effect of maternal age, body mass index, gravidity and parity, previous Caesarean sections, gestational age and the induction regimen on the induction time were analysed. Results: The average induction time was significantly shortened with mifepristone (15.1 ± 11.9 hours with mifepristone vs. 25.3 ± 24.2 hours without mifepristone [p < 0.001]). The combination of mifepristone and misoprostol was most frequently used and proved to be the most effective regimen, reducing the induction period to 13.6 ± 10.3 hours. Besides pre-treatment with mifepristone, gestational age and a history of delivery without Caesarean section were significant influencing factors in reducing the induction time. Conclusion: The induction interval can be significantly shortened by the prior administration of mifepristone. The combination of mifepristone and misoprostol or gemeprost is the most effective regimen for the medical termination of pregnancy.

[Risk consideration for peridural catheter removal in acute coronary syndrome. Epidural hematoma versus stent thrombosis]. / Risikoabwägung vor Periduralkatheterentfernung bei akutem Koronarsyndrom. Epidurales Hämatom vs. Stent-Thrombose.

Perioperative pain therapy using an epidural catheter is the standard operating procedure for numerous surgical interventions. The necessity of initiating anticoagulant therapy in a patient with an epidural catheter requires a careful weighing up between thromboembolic complications and epidural hematoma. The case presented here of a 47-year-old female patient who was operated on for mastectomy with a latissimus dorsi myocutaneous flap demonstrates a possible solution to this dilemma. The patient sustained a perioperative ST elevation myocardial infarction treated with drug-eluting stents while undergoing epidural pain therapy. By using the short-acting antiplatelet drug tirofiban over a time period of 7 days the gap for dual antiplatelet therapy was reduced with the help of specific platelet aggregation assays to a time frame of a few hours to minimize the risk of stent thrombosis. The epidural catheter was removed without complications under consideration of the current recommendations for regional anesthesia and antithrombotic agents.

Exercise in a healthy heart program: a cohort study.

OBJECTIVE: To assess the effects of exercise on resting heart rate (RHR), weight, lipid profile, and blood pressure. We hypothesized that the participants who increased their physical activity would show improvement in their cardiovascular risk factors compared to those who did not. DESIGN: Retrospective chart review over the mean duration of 4.9 years of follow-up. SETTING: Healthy Heart Program Prevention Clinic at St. Paul's Hospital, Vancouver, British Columbia, Canada. PARTICIPANTS: We reviewed 300 charts of patients randomly selected from those who attended the Prevention Clinic between 1984 and 2009. 248 (82.7%) patients were referred for primary prevention and 52 (17.3%) for secondary prevention. PRIMARY AND SECONDARY OUTCOME MEASURES: Weight, RHR, lipid profile, and blood pressure were recorded at the initial and last visit. RESULTS: During a mean of 4.9 years of follow-up, 55% of participants improved their exercise. The mean decrease in the RHR for these patients (group 1) was 5.9 beats per minute (bpm) versus the mean increase of 0.3 bpm for the "no change" group (group 2) (P < 0.01). The mean net weight increase in group 1 was 0.06 kg/year versus 0.25 kg/year in group 2. Because of medications, all patients had a significant improvement in their lipid profiles. Furthermore, there was a statistically significant greater reduction in Framingham Risk Score (FRS) in group 1 versus group 2 (11.8% versus 15.1%, P < 0.01). CONCLUSION: Participation in the program significantly reduces modifiable risk factors for cardiovascular disease. Improved exercise regimen results in lower RHR and greater reduction in FRS. However, even in a Prevention Program, despite strong advocacy of the importance of exercise, a significant percentage of participants does not improve their exercise habits.

Fast identification of wine related lactic acid bacteria by multiplex PCR.

The microflora of must and wine consists of yeasts, acetic acid bacteria and lactic acid bacteria (LAB). The latter group plays an important role for wine quality. The malolactic fermentation carried out by LAB leads to deacidification and stabilisation of wines. Nevertheless, LAB are often associated with wine spoilage. They are mainly responsible for the formation of biogenic amines. Furthermore, some strains produce exopolysaccharide slimes, acetic acid, diacetyl and other off-flavours. In this context a better monitoring of the vinification process is crucial to improve wine quality. Moreover, a lot of biodiversity studies would also profit from a fast and reliable identification method. In this study, we propose a species-specific multiplex PCR system for a rapid and simultaneous detection of 13 LAB species, frequently occurring in must or wine: Lactobacillus brevis, Lb. buchneri, Lb. curvatus, Lb. hilgardii, Lb. plantarum, Leuconostoc mesenteroides, Oenococcus oeni, Pediococcus acidilactici, P. damnosus, P. inopinatus, P. parvulus, P. pentosaceus and Weissella paramesenteroides.

[Radiographic, MR or ultrasound contrast media in pregnant or breast-feeding women: what are the key issues?]. / Röntgen-, MR- oder Ultraschallkontrastmittel während der Schwangerschaft oder Stillzeit: Was ist zu beachten?

The use and the safety of radiographic, MR- or ultrasound contrast media in the diagnostic work-up of pregnant or lactating patients is a frequently discussed question. As only sparse clinical data is available, a careful benefit-risk assessment must contain physico-chemical properties, preclinical data including teratogeneity and embryotoxicity, as well as maternal and foetal exposure. With consideration to the individual risks, iodinated contrast media, macrocyclic MR contrast media with increased stability or sulphur hexafluoride ultrasound contrast media may, if clinically justified, be administered in the smallest possible doses throughout pregnancy. After parental administration of an iodinated contrast medium after the 12th week of pregnancy, the neonate's thyroidal function should be checked during the first week after birth. After parental administration of iodinated, stable macrocyclic, gadolinium or ultrasound contrast media, lactation can be continued normally. In any case, contrast media should be used with caution and only if the benefits outweigh the risk.

Packing spheres tightly: influence of mechanical stability on close-packed sphere structures.

Many experiments and simulations of packings of monodisperse hard spheres report a dominance of the face-centered cubic structure in the hexagonally close-packed limit, even though it has no significant energetic or entropic gain over other close-packed configurations. Combining simulations and experiments, we demonstrate that a simple mechanical instability which occurs during the packing process may play an important role in selecting the face-centered cubic structure over other close-packed alternatives. Our argument is supported by detailed quantitative analyses of key configurations in sphere packings and highlights the importance of the packing dynamics. The proposed mechanism is elementary and should therefore play a role in a wide range of sphere systems.

The lymphangiogenesis inhibitor esVEGFR-2 in human embryos: expression in sympatho-adrenal tissues and differentiation-induced up-regulation in neuroblastoma.

Tumour-induced hem- and lymph-angiogenesis are frequently associated with tumour progression. Vascular endothelial growth factor-C (VEGF-C) is a potent inducer of lymphangiogenesis, while the endogenous soluble splice-variant of VEGF receptor-2, esVEGFR-2, acts as a natural inhibitor. Previously we have shown down-regulation of esVEGFR-2 mRNA in progressed stages of neuro-blastoma (NB), a tumour derived from sympatho-adrenal precursor cells. Here we studied the immunolocalization of esVEGFR-2 in human embryos, infantile adrenal gland and primary NB. We also quantified esVEGFR-2 mRNA in NB cell lines after differentiation-induction by all-trans retinoic acid (ATRA). By immunoperoxidase staining we observed expression of esVEGFR-2 in both the sympathetic trunk and the adrenal medulla. Additionally, esVEGFR-2 was found in spinal ganglia, floor plate of the neural tube, choroid plexus, notochord, arterial endothelium, skeletal muscle, epidermis and gut epithelium. Developing and circulating leukocytes showed the strongest signal. In NB, esVEGFR-2 was considerably stronger in differentiating low grade tumours with neuronal phenotype than in undifferentiated lesions. Differentiation-induction of the NB cell line SMS-Kan with 5-10 µM ATRA resulted in a significant increase of esVEGFR-2 mRNA after 6, 9 and 12 days. We show that esVEGFR-2 is widely expressed in embryonic tissues. Especially, the adrenal medulla and circulating leukocytes seem to be potent inhibitors of lymphangiogenesis. We provide additional evidence for a role of esVEGFR-2 in NB. Thereby, high levels of esVEGFR-2 correlate with a more differentiated phenotype, and may inhibit tumour progression by inhibition of lymphangiogenesis.

Microelectrode-based dielectric spectroscopy of glucose effect on erythrocytes.

The dielectric response of biconcave erythrocytes exposed to D-glucose and L-glucose has been investigated using a double array of planar interdigitated microelectrodes on a glass microchip. Erythrocytes are analyzed under physiological conditions suspended in hypo-osmolar balanced solutions containing different glucose concentrations (0-20 mM). The glucose effect on the cellular dielectric properties is evaluated by analyzing the spectra using two different approaches, the equivalent circuit model and a modified model for ellipsoidal particles. The results show that at elevated glucose concentration (15 mM) the membrane capacitance increases by 36%, whereas the cytosol conductivity slightly decreases with a variation of about 15%. On the contrary, no variation has been registered with L-glucose, a biologically inactive enantiomer of D-glucose. The paper discusses the possible mechanism controlling the membrane dielectric response. As the external D-glucose increases, the number of activated glucose transporter in the erythrocyte membrane raises and the transition from sugar-free state to sugar-bounded state induces a change in the dipole moments and in the membrane capacitance.

Oligonucleotide-based array CGH as a diagnostic tool in multiple myeloma patients.

Multiple myeloma (MM) is a hematological disease caused by malignant proliferation of clonal plasma cells (PCs) known for its clinical and biological heterogeneity. Identification of chromosomal changes in genome of PCs plays a key role in MM pathogenesis and is supposed to have important prognostic significance for MM patients. There are two major genetic entities in MM. Hyperdiploid tumors (H-MM), which include about 50% of MM tumors, often have multiple trisomies involving chromosomes 3, 5, 7, 9, 11, 15, 19, and 21 and a substantially lower prevalence of IgH translocations. Nearly half of tumors are non-hyperdiploid (NH-MM), and mostly have one of five recurrent IgH translocations: 11ql13 (CCND1), 6p21 (CCND3), 16q23 (MAF), 20q12 (MAFB), and 4p16 (FGFR3 and MMSET). The development and expanded use of new technologies, such as genome-wide array-based comparative genomic hybridization (aCGH) has accelerated genomic research in MM. This technique is a powerful tool to globally analyze recurrent copy number changes in tumor genome in a single reaction and to study cancer biology and clinical behaviors. It widely overcame routinely used cytogenetic techniques (G-banding, FISH) both in minimal resolution of chromosomal changes and amount of obtained genomic data important for further analyses and clinical applications. Array CGH technique is now used to better understanding of molecular phenotypes, sensitivity to particular chemotherapeutic agents, and prognosis of these diseases. This paper brings brief literature and methodic overview of oligonucleotide-based array-CGH technique in MM diagnosis.

Dielectric properties of human placenta, umbilical cord and amniotic fluid.

The dielectric properties of freshly delivered human placenta, umbilical cord and amniotic fluid have been acquired at 37 °C and in the frequency range of 200 MHz-10 GHz. The experimental data were fitted to a Cole-Cole expression. The results show that dielectric properties of the umbilical cord are significantly higher than placenta due to the presence of high water content Wharton's jelly. The results also demonstrate large differences in the dielectric properties of amniotic and cerebrospinal fluids. The data presented can be used in numerical simulations of the exposure of pregnant women to electromagnetic fields.

Screening for 'window-period' acute HIV infection among pregnant women in rural South Africa.

OBJECTIVES: The aim of this study was to evaluate the HIV-1 RNA pooled nucleic acid amplification testing (NAAT) strategy to screen pregnant women in the 'window period' of acute HIV infection (AHI) in rural South Africa. METHODS: In 2007 and 2008, 750 consecutive pregnant women on their first antenatal care visit to a primary health care clinic were tested anonymously for HIV infection. HIV-1 RNA pooled NAAT was performed on HIV antibody-negative samples. All positive pools were tested individually and positive samples were classified as incident cases to calculate HIV incidence. RESULTS: The overall HIV prevalence was 37.3% [95% confidence interval (CI) 34.3­41.3]. Of the 467 HIV antibody-negative samples, four (0.9%) were HIV-1 RNA-positive. The mean viral load in the four samples was 386 260 HIV-1 RNA copies/mL (range 64 200­1 228130). The HIV incidence was 11.2%per year (95% CI 0.3­22.1) and all women with AHI were 21 years of age. CONCLUSIONS: Identifying AHI in pregnancy is important for health interventions to reduce perinatal and heterosexual transmission of HIV, and to estimate HIV incidence for epidemiological surveillance.

Niacin: from mechanisms of action to therapeutic uses.

Niacin has broad spectrum lipid modifying and anti-atherosclerotic properties. It is the most effective medication available for raising raise high density lipoprotein (HDL) levels. Despite statin therapy there remains a considerable residual cardiovascular risk attributed to low HDL levels. Currently, statins decrease cardiovascular events and death by about 25-40%. Trials with surrogate endpoints have shown a decrease in endpoints by 60-90% when a combination of statin and niacin has been used. There is a growing interest in niacin in combination therapy to fill the treatment gap by modifying lipid parameters other than low density lipoprotein cholesterol. This review addresses the role of niacin in comprehensive lipid management with an emphasis on its mechanism of action, formulations, side effects, evidence from clinical trials and also focuses on practical issues related to niacin therapy.

[Isolated lymph node metastasis in pericardial fat flap after bronchial stump coverage]. / Isolierte Lymphknotenmetastase im perikardialen Fettlappen nach Bronchusstumpfdeckung.

The occurrence of bronchopleural fistulas is a serious complication after pneumonectomy because of lung cancer and additional bronchial stump coverage within right-sided and left-sided pneumonectomy therefore constitutes the operative standard. This is a case report on the early diagnosis of a lymph node metastasis within the pedicled pericardial fat flap used for bronchial stump coverage. Primary resection of the left lung was carried out 8 months previously because of cancer. Early diagnosis was possible using FDG-PET/CT in the post-operative treatment. The recurrence was successfully treated by en bloc resection and adjuvant radiation.

Liver biochemistry abnormalities in a quaternary care lipid clinic database.

BACKGROUND: The metabolic syndrome and non-alcoholic fatty liver disease are increasing at alarming rates. AIMS: To determine the effect of HMG-CoA reductase inhibitors (statins) on elevated liver enzymes in patients with hyperlipidemia. PATIENTS: Patients with AST above 60 U/L prior to or during treatment with statin therapy at a quaternary care lipid clinic were reviewed. METHODS: A retrospective analysis was conducted. Patients were separated into two groups: Group 1--elevated AST prior to statin therapy; and Group 2--elevated AST during statin therapy. RESULTS: Forty six patients with one or more measurements of AST >60 U/L remained after exclusion criteria were applied. Ten of 13 (77%) group 1 patients had reduced AST levels after initiation of statin therapy. Thirty two of 33 patients (97%) in group 2 had transient AST elevations while on statin therapy; one patient had persistently elevated AST after initiation of treatment. There were no significant adverse events reported. CONCLUSION: Use of HMG-CoA reductase inhibitors in patients with elevated AST resulted in normalization of AST levels. HMG-CoA reductase inhibitors were safe in patients with mildly elevated AST. This may translate to use of HMG-CoA reductase inhibitors in diseases such as non-alcoholic fatty liver disease and non-alcoholic steatohepatitis.

Vascular calcifications in homozygote familial hypercholesterolemia.

BACKGROUND: Patients with homozygous familial hypercholesterolemia (hmzFH) attributable to LDL receptor gene mutations have shown a remarkable increase in survival over the last 20 years. Early onset coronary heart disease (CHD) and calcific aortic valve stenosis are the major complications of this disorder. We now report extensive premature calcification of the aorta in patients with hmzFH. METHODS AND RESULTS: We examined 25 hmzFH patients from Canada; mean age was 32 years (range 5 to 54), and mean baseline cholesterol before treatment was 19+/-5 mmol/L (737+/-206 mg/dL). Aortic calcification was quantified using computed tomography (CT). An elevated mean calcium score was found in patients by age 20 and correlated with age (r(2)=0.53, P=0.001). One quarter (24%) of patients underwent aortic valve surgery. CONCLUSIONS: We document premature severe aortic calcifications in all adult hmzFH patients studied. These presented considerable surgical management challenges. Strategies to identify and monitor aortic calcification in hmzFH by noninvasive techniques are required, as are clinical trials to determine whether additional or more intensive therapies will prevent the progression of such calcifications. Whether vascular calcifications in hmzFH subjects are related to sustained increases in LDL-C levels or to other mechanisms, such as abnormal osteoblast activity, remains to be determined.