Significant Difference In Optical Density Research Articles

Evaluating the hepatotoxic versus the nephrotoxic role of iron oxide nanoparticles: One step forward into the dose-dependent oxidative effects

The present study has been designed to detect the dose-dependent effect of iron oxide nanoparticles (IONPs) on the liver and kidney of rats by evaluating three different doses 30, 300, 1000 mg/kg/day IONPs for 28 days. Forty rats were divided into four groups; I (control), II (low dose), III (medium dose) and IV (high dose).There also was a statistically-significant elevation in the serum levels of hepatic enzymes; AST and ALT in medium & high dose. The elevation of serum ALP, on the other hand, was significant in all IONPs doses.There was significant elevation in the levels of urea creatinine, and MDA in the medium and high doses of IONPs. The activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) showed significant decrease in the high dose only compared to the control group.The serum iron levels increased in a dose-dependent manner in the IONPs-treated groups with highly significant increase in the moderate and high dose groups.On comparing the effect of different doses of IONPs between the liver and kidney, the high dose revealed statistically significant difference (p < 0.05) in the area percent of collagen deposition (54.4 ± 3.9 versus 6.1 ± 2.6) and alpha smooth muscle actin (α-SMA) reaction (7.7 ± 1.5 versus 17.8 ± 4.3) in the liver relative to the kidney. The medium and high doses revealed statistically significant difference in optical density of Periodic acid Schiff (PAS) reaction (45 ± 3.4 versus 50.3 ± 1.8 in the medium dose, and 38.9 ± 6 versus 63 ± 3 in the high dose) and area percent of inducible nitric oxide synthase (iNOS) reaction (12.98 ± 2.7 versus 3.5 ± 0.5 in the medium dose, and 27.91 ± 1.5 versus 7.7 ± 0.6 in the high dose) in the liver relative to the kidney.

In-vitro characterization and evaluation of mesoporous titanium dioxide composite hydroxyapatite and its effectiveness in occluding dentine tubules

BackgroundTo synthesize mesoporous titanium dioxide composite hydroxyapatite (TiO2–HAP) and to evaluate its effectiveness in sealing of occluding dentine tubules.MethodsTiO2–HAP was synthesized by chemical precipitation method and characterized using infrared absorption spectrometer, X-ray diffraction, scanning electron microscope, and specific surface area detector. Forty completely extracted molars were prepared and randomly assigned into Control group, Gluma group, HAP group and TiO2–HAP group according to different treatments. The characteristics of HAP and TiO2–HAP and the sealing effectiveness of dentine tubules in these four groups, including infrared spectrum, surface contact angle, pore size distribution, and re-mineralized enamel surface profiles, were analyzed by suitable characterized techniques. The cytotoxicity of the synthesized TiO2–HAP was tested and compared using 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) colorimetry.ResultsOur results showed TiO2–HAP group had significantly lower contact angle, higher specific surface area, and wider range of pore size distribution than other groups. The majority of dentinal tubules in the TiO2–HAP group were blocked by white matter in a uniformed manner, and the crystals arranged in order grew along the axial direction. In addition, no significant difference in optical density (OD) value was found between control group and TiO2–HAP group (P > 0.05), and cell growth was good in TiO2–HAP group, indicating no cytotoxicity of TiO2–HAP.ConclusionsThe MTT assay identified that TiO2–HAP had little effect on the L929 cell line. We showed TiO2–HAP might be used as a remineralization agent in enamel caries-like lesions.

Influence of different zirconia surface treatments on biofilm formation in vitro and in situ.

ObjectivesTo determine whether the surface treatment of zirconia affects biofilm formation in an in vitro three‐species biofilm model and in situ.Material and methodsZirconia surfaces considered for the transmucosal portion of a zirconia implant were compared with polished pure titanium grade 4 (Tp). Disks 13 mm in diameter of either polished (Zp), polished and heat‐treated (Zpt), machined (Zm), machined and heat‐treated (Zmt) and sandblasted, etched and heat‐treated (Z14) zirconia were fabricated. Surface roughness and wettability of specimens was measured. Biofilm formation was evaluated by safranin staining and scanning electron microscopy (SEM) using a three‐species model, and intraorally with 16 volunteers carrying oral splints in two independent experiments. Relative biofilm formation was compared with Kruskal–Wallis followed by Bonferroni post hoc test (α = 0.05).ResultsIn vitro biofilm formation with optical density values on Zp (0.14 ± 0.01), Zpt (0.14 ± 0.02), Zm (0.13 ± 0.01) and Zmt (0.13 ± 0.01) was significantly lower than on Tp (0.21 ± 0.05) and Z14 (0.20 ± 0.04) (p < .05). In situ biofilm formation was significantly higher on Z14 (0.56 ± 0.45) (p < .05), while no significant differences in optical density were observed among Zp (0.25 ± 0.20), Zm (0.36 ± 0.34) and Tp (0.28 ± 0.22). SEM analysis supported quantitative findings.ConclusionsIn the in vitro, three‐species biofilm model differences in material and surface roughness affected biofilm formation. In situ biofilm formation was mainly affected by the surface roughness of the specimens. Polishing of zirconia is recommended to reduce biofilm formation, while heat treatment has no significant effect.

Post-Synthetic Color Tuning of the Ultra-Effective and Highly Stable Surface-Confined Electrochromic Monolayer: Shades of Green for Camouflage Materials.

We report here on the strategy for the preparation of a series of electrochromic (EC) materials in green shades designed for camouflage purposes. This top-down post-synthetic modification provides access to new EC materials by fine modulation of the color of the surface-confined metalorganic monolayer pre-deposited on indium tin oxide screen-printed supports. Selective on-surface N-quaternization of the outer pyridine unit of the EC metal complex covalently embedded onto an enhanced surface area electrode results in a bathochromic shift of the absorbance signal as well as visual color change from blue to different shades of green. When assembled into solid-state EC devices (ECDs), the materials demonstrate high color differences between colored and bleached states and significant differences in optical density. Upon electrochemical switching, the ECDs initially featuring different shades of green become yellowish or clay. The accessible gamut of colors, fulfilling the requirements for chameleon-like camouflage materials, is able to mimic conditions of various natural environments including forests and sands. Notably, ECDs demonstrate high long-term durability (95% retention of the performance after 3300 cycles), fast coloration (0.6-1.1 s), and bleaching (1.2-3.3 s) times and outstanding coloration efficiencies of 1018-1513 cm2/C. Importantly, post-synthetic N-quaternization/color tuning does not deteriorate the performance of the resulting EC materials and devices as judged by cyclic voltammetry, spectroelectrochemistry, and electrochemical impedance spectroscopy. This work adds to the limited number of reports that explore color tuning of EC molecular layers via on-surface modification with the aim to access new non-symmetric materials. Notably, the facile and straightforward technology presented here allows the creation of green-colored EC materials that are difficult to prepare in other ways.

The effect of garlic extract (Allium sativum L.) (Amaryllidaceae) to eradicate the Porphyromonas endodontalis biofilm: An in-vitro research

Background: The Gram-negative bacterium Porphyromonas endodontalis is one of the causes of endodontic infections. Irrigation in root canal treatment was intended to eliminate bacteria. The garlic extract (Alium sativum Linnaeus) (Amaryllidaceae) is a natural material believed to have antimicrobial effects and may be used as an alternative irrigation solution. Objectives: The aim of this article is to evaluate the effect of garlic extract on the eradication of P. endodontalis biofilms. Methods: The A. sativum extract with concentrations of 100%, 50%, and 25%, NaOCl 5.25%, CHX 2% as a positive control, and sterile Aquadest as a negative control were used as irrigation solutions. A random sample of six groups was tested for P. endodontalis ATCC® 35406D-5TM biofilm eradication by irrigation of the A. sativum extract. Results: It was shown with a one-way analysis of variance that there was a significant difference in optical density (OD) between the results of biofilm eradication using A. sativum with concentrations of 100%, 50%, and 25% and NaOCl 5.25%, CHX 2%, and Aquadest (P 0.05). Conclusion: The garlic extract (A. sativum) is effective in eradicating the biofilm of P. endodontalis in vitro.

A recombinant antigen-based enzyme-linked immunosorbent assay (ELISA) for lungworm detection in seals

BackgroundPinnipeds are frequently infected by the lungworms Otostrongylus circumlitus and Parafilaroides gymnurus (Metastrongyloidea). Infections are frequently associated with secondary bacterial bronchopneumonia and are often lethal. To date, a reliable lungworm diagnosis in individual seals is only possible during necropsy as examination of faeces collected from resting places does not allow assignment to individuals. Therefore, a diagnostic tool for lungworm detection in living seals is desirable for monitoring health of seals in the wild and in captivity. Previously, an ELISA based on recombinant bovine lungworm major sperm protein (MSP) as diagnostic antigen was developed for lungworm diagnosis in cattle. In the present study, this test was adapted for detection of antibodies against lungworms in harbour (Phoca vitulina) and grey seals (Halichoerus grypus). Furthermore, sera of northern elephant seals (Mirounga angustirostris) were tested to evaluate whether the harbour/grey seal ELISA is suitable for this seal species as well.MethodsFor ELISA evaluation, lungworm-positive and -negative sera of harbour and grey seals were analysed using horseradish peroxidase (HRP)-conjugated Protein A as secondary antibody. Optical density was measured and a receiver operating characteristic (ROC) analysis was performed to determine a cut-off value. Potential cross-reactions were examined by testing serum of seals positive for gastrointestinal and heart nematodes, but negative for lungworm infections. In addition, sera of northern elephant seals were analysed.ResultsHarbour and grey seal serum samples showed significant differences in optical density (OD) between serum of infected and uninfected animals resulting in a cut-off value of 0.422 OD with a specificity of 100 % (95 % CI: 87.23-100 %) and a sensitivity of 97.83 % (95 % CI: 88.47-99.94 %). Cross-reactions with heart or gastrointestinal nematodes were not observed. Analysis of northern elephant seal samples resulted in detection of antibodies in animals positive for lungworm larvae at faecal examination.ConclusionsThe ELISA presented is a valuable method for detection of lungworm infections in live harbour and grey seals, providing a monitoring tool to reveal epidemiological dynamics of lungworm infections during health surveillance in free-ranging seals. Furthermore, ELISA results may aid institutions with harbour and grey seals under human care on decisions regarding anthelminthic treatment of individual animals.

Effects of Human Insulin Gene Transfection on the Adipogenic Differentiation of Human Umbilical Cord Mesenchymal Stem Cells in Silk Fibroin Scaffolds &amp;lt;i&amp;gt;in Vitro&amp;lt;/i&amp;gt;

The resorption of the transplanted fat over time limited the use of autologous fat for the reconstruction of soft tissue defect. Tissue engineering (TE) adipose with silk fibroin scaffold could be a promising substitute for soft tissue filling. In this study, we try to develop a tissue engineering adipose in vitro by seeding silk fibroin scaffold with human umbilical cord mesenchymal stem cells (hUCMSCs) after transfected with recombinant human insulin gene lentivirus. Our aim was to observe the effects of the insulin gene transfection on the adipogenesis of hUCMSCs when cultured with silk fibroin scaffolds. The hUCMSCs infected with recombinant lentiviral pLenti6.3-insulin-IRES-EGFP were seeded on silk fibroin scaffolds and cultured in adipogenic differentiation medium for 5 - 7 days. The expression of adipogenic gene PPARγ-2 was tested by RT-PCR after 7 days culture of adipogenic induction. The accumulation of cytoplasmic droplets of neutral lipids was assessed by Oil Red O staining. The RNA and protein expression of transfected insulin gene in hUCMSCs were detected by QPCR and western blot. The effect of recombinant lentivirus transfection on the growth and proliferation of hUCMSCs was observed by MTT test. We observed that the 2-ΔΔCt value of insulin gene expression of hUCMSCs in the transfected group was 300.25 times higher than that in the untransfected group. The western blot showed that a positive band was discerned at the site of a relative molecular mass of 8 × 103 Dalton in transfected group. After adipogenic culture for 7 days, under the fluorescent inverted phase-contrast microscope, after Oil Red O staining, a lot of adipocytes appeared in silk fibroin scaffold; round adipose droplets showed intracellularly; the size of the adipocytes was not homogenous, and the density of adipocytes in transfected group was significantly higher than that in untransfected group (P = 0.007, P 0.05). And there was also no significant difference in optical density (A) between cell group and cell-scalffold group (P = 0.066, P > 0.05). We concluded that insulin gene could obviously promote the adipogenic differentiation of hUCMSCs, and a tissue engineering adipose could be constructed by the silk fibroin scaffolds seeded with human insulin gene-modified hUCMSCs effectively in vitro.

Construction of tissue engineering adipose with human umbilical cord mesenchymal stem cells transfected by insulin gene and silk fibroin scaffold in vitro

Objective To study the construction of tissue engineering adipose in vitro with silk fibroin scaffold and human umbilical cord mesenchymal stem cells (hUCMSCs) transfected by recombinant human insulin gene lentivirus.Methods hUCMSCs infected with recombinant lentiviral pLenti6.3-insulin-IRES-EGFP (Group A) by the best MOI=10 were seeded in silk fibroin scaffold; hUCMSCs transfected by EGFP gene (Group B)was regarded as negative control; and then the cell-scaf-fold complexes were cultured in adipogenic differentiation medium. MTT test was used to detect whether recombinant lentiviral affected the growth and proliferation of hUCMSCs and the growth activity of hUCMSCs seeded in silk fibroin.Results After 5-7 days for adipogenic culture,the numbers of fat-like cells in group A were significantly more than those in group B (P =0.007,P＜0.01).RTPCR results showed that the expression of PPARγ-2 in group A was much stronger than that in group B.MTT test showed that there was no significant difference in optical density (A)at each time between transfected group and nontransfected group (P=0.056,P＞0.05).And there was also no significant difference in optical density (A)between cell group and cell-scaffold group (P =0.066,P＞0.05).Conclusions Insulin gene could obviously promote hUCMSCs getting into adipose,and carrying recombinant human insulin gene lentiviral vector transfection of hUCMSCs and silk fibroin scaffolds could effectively construct tissue engineering adipose in vitro. Key words: Tissue engineering adipose; Human umbilical cord mesenchymal stem cells; Silk fibroin; Insulin; Gene transfection

Effect of pore architecture and stacking direction on mechanical properties of solid freeform fabrication‐based scaffold for bone tissue engineering

Fabrication of a three-dimensional (3D) scaffold with increased mechanical strength may be an essential requirement for more advanced bone tissue engineering scaffolds. Various material- and chemical-based approaches have been explored to enhance the mechanical properties of engineered bone tissue scaffolds. In this study, the effects of pore architecture and stacking direction on the mechanical and cell proliferation properties of a scaffold were investigated. The 3D scaffold was prepared using solid freeform fabrication technology with a multihead deposition system. Various types of scaffolds with different pore architectures (lattice, stagger, and triangle types) and stacking directions (horizontal and vertical directions) were fabricated with a blend of polycaprolactone and poly lactic-co-glycolic acid. In compression tests, the triangle-type scaffold was the strongest among the experimental groups. Stacking direction affected the mechanical properties of scaffolds. An in vitro cell counting kit-8 assay showed no significant differences in optical density depending on the different pore architectures and stacking directions. In conclusion, mechanical properties of scaffolds can be enhanced by controlling pore architecture and stacking direction.

Expressão citofotométrica da Caspase-3 no carcinoma papilífero da tireóide e no bócio colóide

To describe quantitative cytophotometric expression of the marker caspase-3 in colloid goiter and in papillary carcinoma of the thyroid, comparing the immunoexpression between them. An immunohistochemistry study has been made on the protein caspase-3 in 17 of paraffin blocks of papillary carcinoma of the thyroid and 20 cases of colloid goiter, using SAMBA 4000 ® (System of Microscopic Analysis of Automatic Search), aiming analysis of the two variables: marker index and optical density. Statistic analysis indicated a significant difference for marker index between colloid goiter and papillary carcinoma, being this difference larger in the carcinoma. Significant difference in optical density hasn't been found. For colloid goiter, the estimated correlation coefficient between the marker index and optical density was 0,72, indicating the rejection of the null hypothesis (p <0,001), affirming that positive and significant association exists between them. For the papillary carcinoma of the thyroid, the same correlation was 0,34 and so, it is not possible to affirm that there's an association between them. For colloid goiter there is a positive and significant association between the two variables - marker index and optical density -, while for the papillary carcinoma, this is not proved. The quantitative analysis for caspase-3 demonstrates that apoptosis is larger in the papillary carcinoma of the thyroid than in colloid goiter.

Higher optical density of an antigen assay predicts thrombosis in patients with heparin‐induced thrombocytopenia

To correlate optical density and percent inhibition of a two-step heparin-induced thrombocytopenia (HIT) antigen assay with thrombosis; the assay utilizes reaction inhibition characteristics of a high heparin concentration. Patients with more than 50% decrease in platelet count or thrombocytopenia (<150 x 10(9)/L) after exposure to heparin, who had a positive two-step antigen assay [optical density (OD) >0.4 and >50 inhibition with high concentration of heparin] were included in the study. Forty of 94 HIT patients had thrombosis at diagnosis; 54/94 had isolated-HIT without thrombosis. Eight of the isolated-HIT patients developed thrombosis within the next 30 d; thus, a total of 48 patients had thrombosis at day 30. At diagnosis there was no significant difference in OD between HIT patients with thrombosis and those with isolated-HIT. However, OD was significantly higher in all patients with thrombosis (n = 48, 1.34 +/- 0.89), including isolated-HIT patients who later developed thrombosis within 30 d (n = 8, 1.84 +/- 0.64) as compared to isolated-HIT patients who did not develop thrombosis (0.96 +/- 0.75; P = 0.011 and P = 0.008). The Receiver Operative Characteristic Curve showed that OD >1.27 in the isolated-HIT group had a significantly higher chance of developing thrombosis by day 30. None of these groups showed significant difference in percent inhibition. Multivariate analysis showed a 2.8-fold increased risk of thrombosis in females. Similarly, thrombotic risk increased with age and OD values. Higher OD is associated with significant risk of subsequent thrombosis in patients with isolated-HIT; percent inhibition, however, was not predictive.

Candida albicans inactivation and cell membrane integrity damage by microwave irradiation

In indicating the microwave irradiation for disinfecting dentures it is necessary to see how this procedure influences Candida albicans integrity and viability. The aim of this study was to evaluate the ability of microwaves to inactivate C. albicans and damage cell membrane integrity. Two 200-ml C. albicans (ATCC 10231) suspensions were obtained. A sterile denture was placed in a beaker containing the Experimental (ES) or the Control suspension (CS). ES was microwaved at 650 W for 6 min. Suspensions were optically counted using methylene blue dye uptake as indicative of membrane-damaged cells; spread on Agar Sabouraud dextrose (ASD) for viability assay; or spectrophotometrically measured at 550 nm. Cell-free solutions were submitted to content analyses of protein (Bradford and Pyrogallol red methods); Ca++ (Cresolftaleine complexone method); DNA (spectrophotometer measurements at 260 nm) and K+ (selective electrode technique). Data were analysed by Student's t- or Wilcoxon z-tests (alpha = 0.05). All ES cells demonstrated cell membrane damage. Viable cells were non-existent in the ES ASD plates. No significant difference in optical density between ES and CS was observed (P=0.272). ES cells released significantly high protein (P<0.001, Bradford; P=0.005, Pyrogallol red), K+ (P<0.001), Ca++ (P=0.012) and DNA (P=0.046) contents. Microwaves inactivated C. albicans and damaged cell membrane integrity.

Screening for unilateral intracranial abnormalities using near infrared spectroscopy. A preliminary report

Near infrared spectroscopy (NIRS) is being increasingly used for medical applications, including neurosurgical care. This preliminary report describes the use of a low cost, indigenous, non-invasive system where NIRS is used to identify superficial unilateral intracranial abnormalities. The optical density (OD) over each hemisphere was initially studied in 50 normal volunteers. The specificity, sensitivity, reliability and reproducibility of the NIRS generated from the developed equipment in detecting OD were thus confirmed. The OD over each hemisphere was then measured in 71 other individuals, immediately after a computed tomography (CT) scan of the brain was performed. Data was statistically analysed to find the average OD difference (compared to the opposite side) of the various intracranial compartments. Differences in OD suggested a unilateral intracranial abnormality. All those in whom OD differences were detected with the NIRS system had unilateral abnormalities on the CT scan. None of the 53 patients who had a normal CT scan had significant differences in OD.

Influence of exposure history on vitellogenin induction in medaka: a case of ‘estrogen memory’?

In this study, we exposed female medaka to aqueous solutions of o,p′-DDT until tissues residues reached approximately 100 g/g. Male offspring of exposed females and unexposed males that were raised to 6 months of age differed from untreated controls in their response to subsequent 4-day static exposure to 17-β-estradiol (E2; 12 μg/l as determined by steroid EIA). Homogenized liver samples from males from DDT treatments, females from DDT treatments, control males and control females produced two vitellogenin bands on a Western blot with no qualitative differences in band size and location between the groups. To quantify the relative level of vitellogenin, 5 μg of protein from each sample was analyzed by slot blot. A statistical comparison revealed a significant difference in optical density of the slots between control males and DDT exposed males (analysis of variance, n=18, P=0.021; Tukey test, n=9, P=0.047) indicating that previous transgenerational exposure to DDT enhanced the vitellogenic response to E2 exposure in males. These results indicate that exposure to estrogenic chemicals may produce an ‘estrogen memory’ which potentiates the response to a subsequent exposure event.

Histochemical mapping of the substrate for brain-stimulation reward with glycogen phosphorylase

Glycogen phosphorylase is the enzyme that regulates glycogenolysis and it appears that there is a relationship between central levels of glycogen and neuronal activity, which is influenced by a variety of neurotransmitters. In the present study, glycogen phosphorylase histochemistry was used to correlate changes in metabolic activity in response to rewarding lateral hypothalamic stimulation. Rats were allowed to self-stimulate for 1 h per day for ten consecutive days following which postmortem phosphorylase a activity was examined. Significant differences in optical density between the stimulated and contralateral hemispheres were found in three of the eight analyzed structures, two of which, the diagonal band of Broca and the caudate nucleus, showed a greater density of glycogen phosphorylase a on the stimulated side and the third, the habenula, had greater contralateral activity. In conclusion, our data suggest that glycogen phosphorylase activity is a viable but not weighty marker of energy alterations induced by chronic exposure to intracranial self-stimulation, and that it is generally consistent with the patterns revealed by other metabolic indices such as cytochrome oxidase and 2-deoxyglucose autoradiography.

Nitric oxide synthase neurons in different areas of normal aged and Alzheimer's brains

This study investigated the distribution of nitric oxide synthase-containing neurons in the cerebral cortex of individuals with Alzheimer's disease, and compared them with age-matched controls. Paraffin-embedded sections of the frontal (area 10), occipital (area 17) and entorhinal cortices (area 28), and hippocampal formation obtained from 13 autopsy cases were used in the study. Neurons expressing nitric oxide synthase messenger RNA and protein were identified, respectively, by in situ hybridization and immunohistochemistry. Optical densities of nitric oxide synthase-positive neurons were assessed in 50 randomly selected fields of each of the above regions of the cortices, in each case by microscopic photometry. In the frontal cortex of the Alzheimer group, while a decrease in the number of nitric oxide synthase-positive neurons was evident, the nitric oxide synthase neurons, on the other hand, showed an increased optical density in layers II–IV when compared with those of normal ageing. In the occipital cortices, no significant differences in optical density were recorded between the normal ageing and Alzheimer specimens. In the entorhinal cortex, the optical densities of nitric oxide synthase neurons were again similar between the Alzheimer and age-matched control groups. In the hippocampal formation itself, there was an increase of nitric oxide synthase staining in the Alzheimer patients. These results show that (i) nitric oxide synthase neurons are abundant in the human cortex, (ii) the distribution of nitric oxide synthase neurons differs between different cortical regions, and (iii) there are differences between normal ageing and Alzheimer patients in the frontal cortex and the hippocampus.

Use of antimesothelial cell antibody and computer assisted quantitative analysis for distinguishing between reactive and neoplastic serosal tissues.

Nine malignant mesotheliomas and 12 specimens of benign reactive mesothelial hyperplasia were examined using a specific antimesothelial cell antibody. Immunostaining intensity was subsequently estimated by means of image analysis. The mean and standard deviation of integrated optical density in the malignant mesotheliomas differed significantly from those in the mesothelial hyperplasias. In all mesotheliomas but one the integrated optical density was greater than in reactive mesothelial hyperplasia. No significant difference in optical density was observed between the two groups; the standard deviation was significantly higher in the reactive lesions. This technique may be adopted to complement the traditional morphological assessment of primary lesions of the serosal cavities.