In vitro anti-bacterial and biological properties of magnetron co-sputtered silver-containing hydroxyapatite coating

Bacterial infection after implant placement is a significant rising complication. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. In this study, the effect of in vitro antibacterial activity and in vitro cytotoxicity of co-sputtered silver (Ag)-containing hydroxyapatite (HA) coating was evaluated. Deposition was achieved by a concurrent supply of 10 W to the Ag target and 300 W to the HA target. Heat treatment at 400 degrees C for 4 h was performed after 3 h deposition. X-ray diffraction, contact angles measurements, and surface roughness were used to characterize the coating surfaces. The RP12 strain of Staphylococcus epidermidis (ATCC 35984) and the Cowan I strain of Staphylococcus aureus were used to evaluate the antibacterial activity of the Ag-HA coatings, whereas human embryonic palatal mesenchyme cells, an osteoblast precursor cell line, were used to evaluate the in vitro cytotoxicity of the coatings. X-ray diffraction analysis performed in this study indicated peaks corresponding to Ag and HA on the co-sputtered Ag-HA surfaces. The contact angles for HA and Ag-HA surfaces were observed to be significantly lower when compared to Ti surfaces, whereas no significant difference in surface roughness was observed for all groups. In vitro bacterial adhesion study indicated a significantly reduced number of S. epidermidis and S. aureus on Ag-HA surface when compared to titanium (Ti) and HA surfaces. In addition, no significant difference in the in vitro cytotoxicty was observed between HA and Ag-HA surfaces. Overall, it was concluded that the creation of a multifunctional surface can be achieved by co-sputtering the osteoconductive HA with antibacterial Ag.

The analysis of 51 genes in DSM-IV combined type attention deficit hyperactivity disorder: association signals in DRD4, DAT1 and 16 other genes

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, starting in early childhood and persisting into adulthood in the majority of cases. Family and twin studies have demonstrated the importance of genetic factors and candidate gene association studies have identified several loci that exert small but significant effects on ADHD. To provide further clarification of reported associations and identify novel associated genes, we examined 1,038 single-nucleotide polymorphisms (SNPs) spanning 51 candidate genes involved in the regulation of neurotransmitter pathways, particularly dopamine, norepinephrine and serotonin pathways, in addition to circadian rhythm genes. Analysis used within family tests of association in a sample of 776 DSM-IV ADHD combined type cases ascertained for the International Multi-centre ADHD Gene project. We found nominal significance with one or more SNPs in 18 genes, including the two most replicated findings in the literature: DRD4 and DAT1. Gene-wide tests, adjusted for the number of SNPs analysed in each gene, identified associations with TPH2, ARRB2, SYP, DAT1, ADRB2, HES1, MAOA and PNMT. Further studies will be needed to confirm or refute the observed associations and their generalisability to other samples.

In vitro microsomal metabolic studies on a selective mGluR5 antagonist MTEP: characterization of in vitro metabolites and identification of a novel thiazole ring opening aldehyde metabolite

In vitro liver microsomal studies revealed that [14C] MTEP (3-[2-methyl-1,3-thiazol-4-yl)ethynyl] pyridine) was metabolized into three major oxidative metabolites. Metabolite 1 (M1) was shown to be a hydroxymethyl metabolite; M2 was shown to be a pyridine oxide. Moreover, a novel aldehyde metabolite (M3) was identified from mouse liver microsomes. The structure of the aldehyde M3 was elucidated by LC/MS/MS. In addition, methoxyamine, an aldehyde-trapping agent, and accurate mass measurement using a high-resolution quadrupole-time of flight (Q-TOF) instrument, were used to confirm the proposed thiazole ring-opening structure of M3. A mechanism for aldehyde M3 formation was postulated based on MTEP incubation studies with 18O2 and H2 18O using mouse liver microsomes. MTEP was initially oxidized at sulfur, followed by subsequent C4-C5 of thiazole epoxidation, thiozole ring opening and further oxidative desulfation. This proposed thiazole ring-opening mechanism might represent a novel metabolism pathway for xenobiotics containing a thiazole moiety. Species differences in the metabolism of MTEP were observed in mouse, rat, dog, monkey and human liver microsomes. Mouse appears to generate all three oxidative metabolites to a greater extent than other species examined.

Role of pleural fluid C-reactive protein concentration in discriminating uncomplicated parapneumonic pleural effusions from complicated parapneumonic effusion and empyema

The aim of this study was to determine whether pleural fluid C-reactive protein (CRP) is useful in distinguishing complicated parapneumonic pleural effusion (CPPE) and empyema from uncomplicated parapneumonic pleural effusions (UPPE). A total of 69 consecutive patients with parapneumonic effusions were enrolled in the study: 29 with UPPE, 29 with CPPE, and 11 with empyema. Concentrations of standard biochemical parameters together with CRP in the pleural fluid were measured using an immunoturbidimetric assay. Pleural CRP was significantly higher in CPPE (11.6 mg/dl) and in empyema (12.2 mg/dl) than in UPPE (3.9 mg/dl). A cutoff value of 8.7 mg/dl for pleural CRP in the diagnosis of CPPE and empyema resulted in a sensitivity, specificity, and area under the receiver-operating characteristic curve (AUC) of 0.80, 0.97 and 0.94, respectively. Traditional lactic dehydrogenase (LDH) > or = 1000 U/L and glucose < or = 60 mg/dl can differentiate CPPE and empyema from UPPE, with the sensitivity, specificity, and AUC achieving 0.75/0.60.1.00/1.00,0.95/0.22, respectively. However, for the detection of CPPE and empyema, the combination of pleural fluid CRP > or = 8.7 mg/dl and LDH > or = 1000 U/L was valuable in achieving a sensitivity, specificity, and AUC of 0.97/1,00/0.95. This study suggests that measurement of pleural CRP can be useful in the workup of patients with a parapneumonic effusion in order to differentiate CPPE from UPPE.

Lack of association of VEGF promoter polymorphisms with sporadic ALS

The authors tested the association of three vascular endothelial growth factor (VEGF) promoter polymorphisms with sporadic ALS (SALS) to verify the results of a previous study and to investigate their modifier effects on the subphenotypes of SALS in a large family-based and case-control cohort of North American white subjects (N = 1,603). They did not find any association of the VEGF promoter polymorphisms with SALS or its subphenotypes, suggesting that they do not have a direct causal role in ALS.

Electrical Property of Mo-Doped VO2 Nanowire Array Film by Melting−Quenching Sol−Gel Method

Mo-doped VO(2) nanowire array film with good thermochromic properties was prepared by melting-quenching followed by heat treatment in a vacuum. The formation of the new microstructure is related to the cleavage of the oxide lamella along (001) and (100) plane with large interplanar spacing. Mo doping results in the loss of V(4+)-V(4+) pairs and destabilizes the semiconductor phase and consequently lowers the semiconductor-to-metal transition temperature T(c) from 64 to 42 degrees C. Because of enhancement of the electron concentration due to the presence of Mo donors, the Fermi level shifts toward the conduction band, resulting in the decrease of activation energy E(a), hence, temperature coefficient of resistance.

Classification of surface EMG signals using optimal wavelet packet method based on Davies-Bouldin criterion

In this paper we present an optimal wavelet packet (OWP) method based on Davies-Bouldin criterion for the classification of surface electromyographic signals. To reduce the feature dimensionality of the outputs of the OWP decomposition, the principle components analysis was employed. Then we chose a neural network classifier to discriminate four types of prosthesis movements. The proposed method achieved a mean classification accuracy of 93.75%, which outperformed the method using the energy of wavelet packet coefficients (with mean classification accuracy 86.25%) and the fuzzy wavelet packet method (87.5%).

A mechanism for anomalous decline in radon precursory to an earthquake

Mechanisms for interpreting anomalous decreases in radon in ground water prior to earthquakes are examined with the help of a case study to show that radon potentially is a sensitive tracer of strain changes in the crust preceding an earthquake. The 2003 Chengkung earthquake of magnitude (M) 6.8 on December 10, 2003, was the strongest earthquake near the Chengkung area in eastern Taiwan since 1951. The Antung radon-monitoring station was located 20 km from the epicenter. Approximately 65 d prior to the 2003 Chengkung earthquake, precursory changes in radon concentration in ground water were observed. Specifically, radon decreased from a background level of 780 pCi/L to a minimum of 330 pCi/L. The Antung hot spring is situated in a fractured block of tuffaceous sandstone surrounded by ductile mudstone. Given these geological conditions, we hypothesized that the dilation of brittle rock mass occurred at a rate faster than the recharge of pore water and gas saturation developed in newly created cracks preceding the earthquake. Radon partitioning into the gas phase may explain the anomalous decrease of radon precursory to the 2003 Chengkung earthquake. To support the hypothesis, vapor-liquid, two-phase radon-partitioning experiments were conducted at formation temperature (60 degrees C) using formation brine from the Antung hot spring. Experimental data indicated that the decrease in radon required a gas saturation of 10% developed in rock cracks. The observed decline in radon can be correlated with the increase in gas saturation and then with the volumetric strain change for a given fracture porosity.

Synthesis and Electrical Transport of Single-Crystal NH4V3O8 Nanobelts

Monoclinic NH(4)V(3)O(8) single-crystalline nanobelts with widths of 80-180 nm, thicknesses of 50-100 nm, and lengths up to tens of micrometers have been synthesized at large scale in an ammonium metavanadate solution by a templates/catalysts-free route. Such nanobelts grow along the direction of [010]. The individual NH(4)V(3)O(8) nanobelt exhibits nonlinear, symmetric current/voltage (I/V) characteristics, with a conductivity of 0.1-1 S/cm at room temperature and a dielectric constant of approximately 130. The dominant conduction mechanism is based on small polaron hopping due to ohmic mechanism at low electric field below 249 V/cm due to Schottky emission at medium electric field between 249 and 600 V/cm and due to the Poole-Frenkel emission mechanism at high field above 600 V/cm.

Down regulation of the L-type Ca2+ channel, GRK2, and phosphorylated phospholamban: protective mechanisms for the denervated failing heart

We previously found that a canine model of selective surgical ventricular denervation (VD), which does not permit increased sympathetic tone during the pathogenesis of heart failure (HF), tolerated the development of HF better than controls. To investigate the cellular mechanisms, we examined cellular contraction and L-type Ca(2+) channel currents (I(Ca)) and their responses to beta-adrenergic receptor (beta-AR) stimulation in left ventricular myocytes from 1) control, 2) VD, 3) HF induced by rapid pacing, and 4) HF induced in VD (VD-HF) dogs. The magnitude of myocyte contraction and rate of relaxation in VD were similar to control but were depressed in both HF and VD-HF. These changes were associated with reduced protein expression of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a) and protein kinase A phosphorylated phospholamban (PLB), which was reduced in HF, but essentially abolished in VD-HF. beta-AR kinase (GRK2) was increased in HF but reduced in VD-HF. Basal I(Ca) density did not differ among control, VD, and HF groups, but VD-HF myocytes showed a markedly reduced I(Ca) density (approximately 40%). Compared to controls, the sensitivity of I(Ca) to isoproterenol (ISO), was significantly higher in VD, but reduced in HF. While I(Ca) responses to ISO in VD-HF were maintained at control levels, the amplitude of the ISO-stimulated I(Ca) was significantly smaller (approximately 50%) compared with HF myocytes. The relative decrease in Ca(2+) influx due to downregulation of I(Ca) density may contribute to the cardioprotective effects in VD-HF hearts by preventing Ca(2+) overload during the development of HF. These findings, in combination with the virtual abolition of phosphorylated PLB in VD-HF and the decrease in GRK2, may explain, in part, why VD dogs tolerate the development of HF better than control dogs.

Phase I trial of liposomal doxorubicin and ZD 1839 in patients with refractory gynecological malignancies or metastatic breast cancer

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Background: Liposomal Doxorubicin has activity in both breast and ovarian cancer. Preclinical data reported by several investigators have suggested that ZD1839 acts synergistically with chemotherapy in ovarian cancer cells expressing high levels of EGFR. Given the lack of cross resistance and the different targets for these agents a Phase I trial was initiated examining the safety and the efficacy of the combination of Liposomal Doxorubicin and ZD1839. Methods: Dose limiting toxicity was defined within the first two cycles of treatment. The dose escalation schema was described as such: Results: As of January 2006, 23 patients have been enrolled in this study (GYN = 6; Breast 17). Six patients were enrolled in dose level 1 and no DLTs were observed. Dose level 2 enrolled six patients. One DLT was observed (febrile neutropenia). As defined by protocol an additional 6 patients were accrued to dose level 2. Accrual to dose level 3 began on 11/2005. One patient has completed 2 cycles and no additional DLTs have been noted. MTD has not yet been reached. SAEs have included mental status changes, and two CNS bleeds (believed most likely to be unrelated to study drug combination). Toxicities noted in cycle 3 and above have been mild with the exception of 2 grade 3 and 2 grade 4 toxicities related to skin and GI toxicity. No cardiac toxicity was observed. Doxil dose modifications (cycle 3 +) occurred in 7 patients. Best response to therapy has included 2 PRs and 10 patients with SD. Eleven patients to date have had progressive disease. The trial continues to accrue. Correlative studies including EGFR expression and CECs and PKs (at MTD) are planned. Conclusion: Liposomal Doxorubicin in conjunction with ZD1839 is tolerable regimen in patients with advanced breast and ovarian cancer. To date MTD has not been reached.

[Table: see text]

[Table: see text]

Phase II trial of vaccination with full length NY-ESO-1/IMX in patients with advanced malignant melanoma

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Background: NY-ESO-1 is an immunogenic “cancer-testis” (CT) antigen, expressed in many cancers including melanoma. Iscomatrix adjuvant (IMX), a saponin-based adjuvant, was formulated with NY-ESO-1 (ESO) protein (ESO/IMX). ESO/IMX was highly immunogenic as defined by ESO specific antibody (Ab), delayed type hypersensitivity (DTH) & T-cell responses in patients (pts) with resected ESO+ve cancer. Disease free survival in vaccine recipients with resected melanoma appeared longer than in controls. A prospective evaluation was subsequently undertaken to determine whether ESO/IMX could mediate antitumor responses in pts with advanced NY ESO-1+ve melanoma. Methods: 27 pts were vaccinated in a trial designed to assess objective clinical responses, safety, & immunogenicity. Vaccination consisted of 100 μg ESO/IMX administered q 4 wk × 3; this cycle was repeated in pts without symptomatic progression unless they required other treatment. Pts were then eligible to continue vaccination q12 weeks so long as they were responding or stable. Results: ESO/IMX was well tolerated. 13 pts progressed when evaluated after the first cycle at week 11. No objective clinical responses were seen. Vaccine-induced antibody titers to NY-ESO-1 were comparable to those seen in the earlier minimal residual disease trial (ranging to > 1: 390,000). DTH & T-cell responses were less marked. This occurred despite many pts with advanced measurable disease having pre-existing spontaneous ESO immunity ( Table ). DTH responses were seen in 11 pts; 5 had pre-existing responses (2 were boosted) and 6 were induced. The DTH responses were lost by week 33. Conclusion: No objective responses were seen. Vaccine-induced immunity appeared to be attenuated in the presence of advanced metastatic disease. Ongoing laboratory studies are investigating the role of regulatory T cells in the suppression of ESO-specific immunity in these pts with a view to adopting strategies to counter regulatory responses e.g. low-dose cyclophosphamide prior to vaccination.

[Table: see text]

[Table: see text]

The impact of an exercise intervention on body composition, fat distribution, and weight in breast cancer survivors

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Background: Recent research has demonstrated that obesity increases a woman’s risk of breast cancer recurrence. Although the mechanism is not well understood, it is known that obese women have higher levels of insulin and other hormones related to energy balance. In this study, we sought to explore the impact of an exercise intervention on body composition, fat distribution, weight, and insulin levels in a population of breast cancer survivors. Methods: Inactive women with early stage breast cancer who had completed adjuvant chemotherapy and/or radiation were randomized to a 16-week exercise intervention or a normal care control group. The exercise intervention consisted of supervised strength training and unsupervised cardiovascular exercise, with a goal of 2 strength training sessions and 90 minutes of cardiovascular exercise each week. Measurement of weight, body composition, and circumference at the waist and hip, were collected at baseline and after 16 weeks in both groups. Fasting blood samples were also collected at these two time points for insulin and glucose levels, so that changes in these levels between the intervention and control groups could be compared. Results: Eighty-five women have been randomized; complete anthropometric data are presently available for 51. Women in the exercise group experienced a nonsignificant decrease in body weight, body fat, and circumference at the waist and hip, as compared to control patients. Participants completed a median of 84% of scheduled strength training sessions and 80% of recommended cardiovascular sessions. Strength increased by an average of 40% during the exercise intervention. Prior studies have demonstrated significant inter-assay variability in biomarker testing, thus insulin and glucose testing will be performed when all patients have completed the protocol. Conclusions: Compliance with the exercise intervention was good. Women in the exercise group experienced non-significant changes in anthropometric measures, and increased strength during the 16-week intervention. Final strength and anthropometric data from the entire cohort will be available for presentation. This project was supported by an ASCO Career Development Award and funding from the Lance Armstrong Foundation.

No significant financial relationships to disclose.

Germline BCL-2 sequence variants and inherited predisposition to prostate cancer

Apoptosis is an essential physiological process that regulates cellular proliferation. Here, we explored the effect of DNA sequence variation within the BCL-2 gene on prostate cancer susceptibility in three clinical populations, consisting of 428 African Americans, 214 Jamaicans and 218 European Americans. We observed a 70% reduced risk for prostate cancer among the European Americans who had possessed two copies of a promoter variant -938C/A. Additionally, common BCL-2 haplotypes appeared to influence prostate cancer risk; however, studies in larger data sets are needed to confirm our findings. Our data suggest that inherited BCL-2 variants may be associated with a decrease in prostate cancer susceptibility.