2012 Vol. 26, No. 3
Nanotechnology is gaining tremendous impetus due to its capability of modulating metals into their nanosize, which drastically changes the chemical, physical and optical properties of metals. Nanoparticles have been introduced as materials with good potential to be extensively used in biological and medical applications. Nanoparticles are clusters of atoms in the size range of 1-100 nm. Inorganic nanoparticles and their nano-composites are applied as good antibacterial agents. Due to the outbreak of infectious diseases caused by different pathogenic bacteria and the development of antibiotic resistance, pharmaceutical companies and researchers are searching for new antibacterial agents. The metallic nanoparticles are the most promising as they show good antibacterial properties due to their large surface area to volume ratios, which draw growing interest from researchers due to increasing microbial resistance against metal ions, antibiotics and the development of resistant strains. Metallic nanoparticles can be used as effective growth inhibitors in various microorganisms and thereby are applicable to diverse medical devices. Nanotechnology discloses the use of elemental nanoparticles as active antibacterial ingredient for dental materials. In dentistry, both restorative materials and oral bacteria are believed to be responsible for restoration failure. Secondary caries is found to be the main reason to restoration failure. Secondary caries is primarily caused by invasion of plaque bacteria (acid-producing bacteria) such as Streptococcus mutans and lactobacilli in the presence of fermentable carbohydrates. To make long-lasting restorations, antibacterial materials should be made. The potential of nanoparticles to control the formation of biofilms within the oral cavity is also coming under increasing scrutiny. Possible uses of nanoparticles as topically applied agents within dental materials and the application of nanoparticles in the control of oral infections are also reviewed.
The purpose of the present study was to investigate the association between admission clinical characteristics and outcomes at discharge among acute ischemic stroke patients in the Chinese population. A total of 2,673 patients with acute ischemic stroke were included in the present study. The clinical characteristics at admission and other study variables were collected for all patients. The study outcome was defined as neurological deficiency (National Institute of Health Stroke Scale score≥10) at discharge or in-hospital death. Compared with the subjects without neurological deficiency at discharge or in-hospital death, the subjects with neurological deficiency at discharge or in-hospital death had a significantly higher prevalence of hyperglycemia or history of atrial fibrillation at admission. Age≥ 80 years, hyperglycemia, hypertension, and history of atrial fibrillation were significantly associated with neurological deficiency at discharge or in-hospital death after adjustment for other variables. It is concluded that old age (≥80 years), hyperglycemia, hypertension and history of atrial fibrillation are significantly associated with neurological deficiency at discharge or in-hospital death among patients with acute ischemic stroke.
The purpose of this study was to evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel as a rescue regimen in the treatment of patients with advanced non-small-cell lung cancer. We retrospectively reviewed the medical records of 20 patients with stage IV non-small-cell lung cancer. The patients had progressive disease after standard antitumor therapy and subsequently received intravenous albumin-bound paclitaxel at the dose of 100 mg/m2 in weekly schedule. Cumulative findings showed that the overall response rate was 30.0%, the disease control rate amounted to 40%, and the 1 year survival rate was 30%. In addition, the median time to progression and the median survival time reached 5 and 10 months, respectively. Meanwhile, no severe hypersensitivity reactions and grade 4 adverse effects were reported. In summary, weekly-administered albumin-bound paclitaxel seems to be an effective and safe regimen for elderly patients with stage IV non-small-cell lung cancer who were refractory to conventional therapy.
99m Tc-methoxyisobutyl isonitrile (MIBI) is a suitable transport substrate for the multidrug resistance gene product P-glycoprotein (P-gp) and widely used for tumor imaging. Bromocriptine has been shown to inhibit the ATPase activity and the function of P-gp. We hypothesized that bromocriptine could promote the accumulation of MIBI by inhibiting P-gp activities, a feature that can be taken advantage of for enhancing 99m Tc-MIBI imaging. In the current study, we sought to investigate whether bromocriptine enhanced the uptake of 99m Tc-MIBI in hepatocellular carcinoma patients. Sixty primary hepatocellular carcinoma patients received 99m Tc-MIBI single photon emission computer tomgraphy (SPECT) prior to surgery. 99m Tc-MIBI SPECT was performed 15 and 120 min after injection of 20 mCi 99m Tc-MIBI, and early uptake, delayed uptake (L/Nd), and washout rate (L/Nwr) of 99m Tc-MIBI were obtained. In addition, a second 99m Tc-MIBI SPECT was performed according to the same method 48 h after bromocriptine administration. We found that, prior to bromocriptine administration, significant MIBI uptake in tumor lesions was noted in only 10 (16.7%, 10/60) patients with hepatocellular carcinoma. No significant MIBI uptake was observed in the tumor lesions of the remaining 50 (83.3%, 50/60) hepatocellular carcinoma patients. Following bromocriptine administration, all the patients without apparent MIBI uptake demonstrated significant MIBI uptake on 99m Tc-MIBI SPECT (P < 0.05). Our findings indicate that bromocriptine enhances the uptake of 99m Tc-MIBI in patients with hepatocellular carcinoma.
The purpose of this study was to investigate the nuclear magnetic resonance (NMR) assignments of hydrolyzed products extracted from human blood plasma. The correlations between chemical, functional and structural properties of highly toxic pesticides were investigated using the PreADME analysis. We observed that toxic pesticides possessed higher molecular weight and, more hydrogen bond donors and acceptors when compared with less toxic pesticides. The occurrence of functional groups and structural properties was analyzed using 1 H-NMR. The 1H-NMR spectra of the phosphomethoxy class of pesticides were characterized by methyl resonances at 3.7-3.9 ppm (δ) with the coupling constants of 11-16 Hz (JP-CH3). In phosphoethoxy pesticides, the methyl resonance was about 1.4 ppm (δ) with the coupling constant of 10 Hz (JP-CH2) and the methylene resonances was 4.2-4.4 ppm (δ) with the coupling constant of 0.8 Hz (JP-CH3), respectively. Our study shows that the values of four parameters such as chemical shift, coupling constant, integration and relaxation time correlated with the concentration of toxic pesticides, and can be used to characterise the proton groups in the molecular structures of toxic pesticides.
Blood stored in a blood bank undergoes a series of chemical changes and storage lesions. The purpose of this study was to assess the effect of ozone on the rheological and electrical properties of stored human blood. Venous blood samples, obtained from three healthy humans, were treated with different concentrations of ozone (30, 50, 70 and 80 μg/mL) for three weeks in vitro. Ozone was generated from portable medical-grade oxygen using electrical corona arc discharge. The ultravioletvisible absorption of hemoglobin in the wavelength of 300-700 nm showed that ozone in this range did not interact with iron ions and it was not toxic below the concentration of 80 μg/mL. The changes of blood viscosity were also measured. The electrical conductivity and permittivity, in the frequency range from 5 to 50 MHz, were measured in the control and treated samples subjected to different concentrations of ozone at different stored periods. The results showed that the conductivity and permittivity measurements may serve as a useful indicator in the quality assessment of blood samples stored in the blood bank.
The purpose of this study was to investigate the antibacterial activity of calcium hydroxide [Ca(OH)2] combined with chitosan solutions against Enterococcus faecalis-infected root canal dentin and the effect of this new intracanal medicament on the bond strength of RealSeal sealer to radicular dentin. An experimental intracanal medicament was prepared by mixing different concentrations of chitosan solution (25%, 50%, and 100%, W/V) to Ca(OH)2 powder. Antibacterial activity was evaluated and the total numbers of colony forming units were determined. Bonding ability of RealSeal sealer to radicular dentin was evaluated using push-out bond strength test. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's multiple comparison tests. We found that Ca(OH)2 combined with different concentrations of chitosan solutions showed better antibacterial activity than Ca(OH)2 mixed with saline, without significantly affecting the bond strength of RealSeal sealer to radicular dentin (P > 0.05). The findings suggest that Ca(OH)2 combined with chitosan is a promising intracanal medicament and may be effective in endodontic therapy.
Diabetic neuropathies are a family of nerve disorders caused by diabetes. Symptoms of the disease include nerve palsy, mononeuropathy, mononeuropathy multiplex, diabetic amyotrophy, painful polyneuropathy, autonomic neuropathy, and thoracoabdominal neuropathy. In this study, type 2 diabetes in rats was induced with nicotinamide-streptozotocin. Drug treatment was initiated on the d 15, with the combination regimen of metformin, pioglitazone and glimipiride or metformin and sitagliptin or sitagliptin, amitriptyline and sitagliptin and led to significantly improved glycemic control, increased grip strength and paw jumping response on d 21, 28 and 35 (P < 0.001). Significant increases in blood protein levels and decreases in urinary protein levels were observed in the animals treated with the different regimens on d 21, 28 and 35 (P < 0.001). Combined treatment of streptozotocin and nicotinamide caused marked degeneration of nerve cells, while administration of metformin and sitagliptin showed tissue regeneration and no body weight gain. In conclusion, treatment with sitagliptin and sitagliptin combined with metformin or amitriptyline results in no body weight gain, but causes an increase in grip strength and pain sensitivity, exhibits neural protection, and reverses the alteration of biochemical parameters in rats with streptozotocin-nicotinamide induced type 2 diabetes.
We sought to evaluate the feasibility and hemodynamic performance of a new self-expanding bioprosthesis and 16-F delivery system in sheep. A 23-mm new self-expanding aortic bioprosthesis was implanted in sheep (n = 10) with a 16-F catheter via the right common carotid artery. Each sheep underwent angiography and coronary angiography before intervention, immediately and 1 h after stent implantation. Electrocardiographic monitoring was carried out during and 2 h after the procedure. Transthoracic echocardiography was employed to detect hemodynamic performance before intervention, immediately and 1 and 2 h after stent implantation. All sheep were euthanized 2 h after successful implantation for macroscopic inspection. In all cases, the new self-expanding aortic bioprosthesis was successfully delivered to the aortic root and released with a 16-F catheter. Successful implantation was achieved in 8 of 10 sheep. Hemodynamic performance and device position of successful implantation were stable 2 h after device deployment. Atrioventricular block was not observed. We conclude that it is feasible to implant the new self-expanding aortic valve with a 16-F delivery system into sheep hearts via the retrograde route.
We sought to investigate the effects of telmisartan on high-fat diet-induced hypertension and to explore the possible underlying mechanisms. Rats receiving high-fat diet were randomly divided into two groups, the telmisartan group (n = 9) and the high-fat diet group (n = 10). The control group consisted of age-matched rats on a regular diet (n = 10). At the end of the treatment, the body weight, blood pressure, insulin sensitivity and serum adiponectin levels of all rats were examined, and their visceral fat was extracted and weighed. Our results showed that telmisartan improved insulin resistance and dyslipidemia and increased serum adiponectin levels. Telmisartan also lowered both systolic blood pressure and diastolic blood pressure, and decreased the accumulation of perirenal fat associated with high-fat diet. Furthermore, telmisartan increased adiponectin mRNA expression in the perirenal fat. Correlation analysis showed that both systolic blood pressure and diastolic blood pressure were positively correlated with perirenal fat. These effects of telmisartan may be mediated through decreases in perirenal fat and contributed to the improvement of perirenal fat function. Our findings suggested a strong link between perirenal fat and high-fat diet-induced hypertension, and identified telmisartan as a potential drug for the treatment of obesity-related hypertension.
In the current study, we sought to investigate whether lysed Enterococcus faecalis FK-23 (LFK), a heat-killed probiotic preparation, attenuated eosinophil influx into the upper airway and had immunomodulatory activity in a murine allergic rhinitis model. Eighteen BALB/c mice were divided into three groups; the ovalbumin (OVA)-sen-sitized/challenged group, which received saline orally for 6 weeks (OVA group), the OVA-sensitized/challenged group, which received LFK orally for 6 weeks (LFK-fed group), and the non-sensitized group, which received saline for 6 weeks (saline control group). Nasal rubbing and sneezing were monitored during the study. After the final challenge, interleukin (IL)-4, interferon (IFN)-γ, and OVA-specific IgE levels in the sera and splenocyte culture supernatants were determined, eosinophilic infiltrate into the upper airway was quantified, and splenic CD4+ CD25+ regulatory T cells (Tregs) were examined by flow cytometry. We found that nasal rubbing was sig-nificantly reduced in LFK-fed mice compared to the OVA group on d 27 and 35, and sneezing was significantly inhibited by LFK administration for 35 d. LFK-fed mice had significantly less eosinophil influx into the nasal mucosa than the OVA group. There were no significant differences between the LFK-fed group and OVA group in the serum and splenocyte culture supernatant levels of IL-4, IFN-γ, and OVA-specific IgE. Interestingly, the LFK-fed mice had a significantly greater percentage of splenic CD4+CD25+ Tregs than OVA group. Our results indicate that oral administration of LFK may alleviate nasal symptoms, reduce nasal eosinophilia, and increase the percentage of CD4+CD25+ Tregs in experimental allergic rhinitis.