Focusing and scanning microscopy with propagating surface plasmons.

Here we demonstrate a novel surface plasmon polariton (SPP) microscope which is capable of imaging below the optical diffraction limit. A plasmonic lens, generated through phase-structured illumination, focuses SPPs down to their diffraction limit and scans the focus with steps as small as 10 nm. This plasmonic lens is implemented on a metallic nanostructure consisting of alternating hole array gratings and bare metal arenas. We use subwavelength scattering holes placed within the bare metal arenas to determine the resolution of our microscope. The resolution depends on the size of the scanning SPP focus. This novel technique has the potential for biomedical imaging microscopy, surface biology, and functionalization chemistry.

Optical control of plasmonic Bloch modes on periodic nanostructures.

We study and actively control the coherent properties of surface plasmon polaritons (SPPs) optically excited on a nanohole array. Amplitude and phase of the optical excitation are externally controlled via a digital spatial light modulator (SLM) and SPP interference fringe patterns are designed and observed with high contrast. Our interferometric observations reveal SPPs dressed with the Bloch modes of the periodic nanostructure. The momentum associated with these dressed plasmons (DP) is highly dependent on the grating period and fully matches our theoretical predictions. We show that the momentum of DP waves can, in principle, exceed the SPP momentum. Actively controlling DP waves via programmable phase patterns offers the potential for high field confinement applicable in lithography, surface enhanced Raman scattering, and plasmonic structured illumination microscopy.

BMI and attitudes and beliefs about physical activity and nutrition of parents of adolescents with intellectual disabilities.

BACKGROUND: The purpose of this study was: (1) to evaluate the beliefs, attitudes and behaviours associated with nutrition and physical activity of parents with adolescents with intellectual disabilities (ID); (2) to determine if these variables related to the body mass index (BMI) of the adolescents and the parents' BMI; and (3) to investigate if the parents' perception of their child's weight status was accurate. METHODS: A survey was used to collect information on BMI and attitudes and beliefs about nutrition and physical activity from parents (n = 207) of adolescents with ID attending schools participating in the Best Buddies Program. RESULTS: Approximately 45% of the adolescents were overweight or obese and over two-thirds of the parents were either overweight or obese. There was a significant difference in child's BMI by parents' description, F(3,158) = 72.75, P < 0.001. Factor analysis on questions on physical activity and nutrition revealed three factors (Factor 1 - Family Healthy Habits, Factor 2 - Parental Role and Factor 3 - Parental Activity) extracting 63% of the variance. The BMI of the adolescents significantly correlated with Factors 2 and 3. Children categorised as having a lower BMI had parents who agreed significantly more (r = -0.22, P < 0.005) with questions about being role models. There was a significant correlation between BMI for both the parents and adolescents and frequency of fast foods purchased. CONCLUSION: Efforts need to be made to provide parents of adolescents with ID tailored information about how they can assist their child in managing their weight. This information should emphasise to parents the important part they play as role models and as providers for healthy choices for physical activity as well as nutrition.

Real-world impact of laparoscopic surgery for rectal cancer: a population-based analysis.

Background: Randomized trials have demonstrated equivalent oncologic outcomes and decreased morbidity in patients with rectal cancer who undergo laparoscopic surgery (lapsx) compared with open surgery (opensx). The objective of the present study was to compare short-term outcomes after lapsx and opensx in a real-world setting. Methods: A national discharge abstract database was used to identify all patients who underwent rectal cancer resection in Canada (excluding Quebec) from April 2004 through March 2015. Short-term outcomes examined included same-admission mortality and length of stay (los). Results: Of 28,455 patients, 82.4% underwent opensx, and 17.6%, lapsx. The use of lapsx increased to 34% in 2014 from 5.9% in 2004 (p < 0.0001). Same-admission mortality was lower among patients undergoing lapsx than among those undergoing opensx (1.08% and 1.95% respectively, p < 0.0001). On multivariable analysis, the odds of same-admission mortality with lapsx was 36% lower than that with opensx (odds ratio: 0.64; p = 0.003). Median los was shorter after lapsx than after opensx (5 days and 8 days respectively, p = 0.0001). The strong association of lapsx with shorter los was maintained on multivariable analysis controlling for patient, surgeon, and hospital factors. Conclusions: For patients with rectal cancer, shorter los and decreased same-admission mortality are associated with the use of lapsx compared with opensx.

Rigid-body motion correction in hybrid PET/MRI using spherical navigator echoes.

Integrated positron emission tomography and magnetic resonance imaging (PET/MRI) is an imaging technology that provides complementary anatomical and functional information for medical diagnostics. Both PET and MRI are highly susceptible to motion artifacts due, in part, to long acquisition times. The simultaneous acquisition of the two modalities presents the opportunity to use MRI navigator techniques for motion correction of both PET and MRI data. For this task, we propose spherical navigator echoes (SNAVs)-3D k-space navigators that can accurately and rapidly measure rigid body motion in all six degrees of freedom. SNAVs were incorporated into turbo FLASH (tfl)-a product fast gradient echo sequence-to create the tfl-SNAV pulse sequence. Acquiring in vivo brain images from a healthy volunteer with both sequences first compared the tfl-SNAV and product tfl sequences. It was observed that incorporation of the SNAVs into the image sequence did not have any detrimental impact on the image quality. The SNAV motion correction technique was evaluated using an anthropomorphic brain phantom. Following a stationary reference image where the tfl-SNAV sequence was acquired along with simultaneous list-mode PET, three identical PET/MRI scans were performed where the phantom was moved several times throughout each acquisition. This motion-up to 11° and 14 mm-resulted in motion artifacts in both PET and MR images. Following SNAV motion correction of the MRI and PET list-mode data, artifact reduction was achieved for both the PET and MR images in all three motion trials. The corrected images have improved image quality and are quantitatively more similar to the ground truth reference images.

Full characterization of anisotropic diffuse light.

We demonstrate a method for fully characterizing diffuse transport of light in a statistically anisotropic opaque material. Our technique provides a simple means of determining all parameters governing anisotropic diffusion. Anisotropy in the diffusion constant, the mean free path, and the extrapolation length are, for the first time, determined independently. These results show that the anisotropic diffusion model is effective for modeling transport in anisotropic samples, providing that the light is allowed to travel several times the transport mean free path from the source.

Dental hygiene regulation: a global perspective.

Occupational regulation of health personnel is important to professional associations and their members, the public that relies on their services and the regulatory agencies responsible for their conduct. There is increasing interest in ensuring that dental hygiene regulation fosters the continuing evolution of the profession and its contribution to oral health. The keynote address for the 2007 Regulatory Forum on Dental Hygiene, this paper discusses the rationale for and issues pertaining to occupational regulation, outlines the evolvement of dental hygiene and identifies regulatory options for the profession. Professional regulation exists to ensure public safety, health and welfare. However, negative political-economic side effects coupled with environmental pressures have resulted in increased scrutiny for health professionals. One such profession is dental hygiene. Its evolution has been dramatic, in particular over the past few decades, as illustrated by its rapidly increasing numbers and broader distribution globally, gradual shift to the baccalaureate as the entry-level educational requirement and increase in postgraduate programs and expanding scope of practice and increased professional autonomy. Regulatory changes have been more gradual. Regulation is mandatory for the vast majority of dental hygienists. Of the options available, the practice act - the most rigorous type, is predominant. Globally, regulation tends to be administered directly by the government (n = 9 countries) more so than indirectly through a dental board (n = 4) or self-regulation (n = 3). Whether regulated directly or indirectly, dental hygienists increasingly are seeking a greater role in shaping their professional future. Self-regulation, its responsibilities, misperceptions and challenges, is examined as an option.

Limitations of radiolabeled monoclonal antibodies for localization of human neoplasms.

Tumor-associated monoclonal antibodies were radiolabeled with 125I and 131I and given i.v. in pairs to 19 patients 1-26 days prior to surgical excision of primary and metastatic breast, ovarian, and gastrointestinal tumors. For individual patients each monoclonal antibody was designated as specific or nonspecific according to prior immunoperoxidase staining results on the appropriate target neoplastic tissues. Quantitation of antibody uptake was performed on resected normal and neoplastic tissues. Although good tumor:non-tumor ratios were obtained with the specific antibodies (maximal tumor:blood ratio, 35.8:1 at 12 days postadministration), the absolute amount of radiolabel detected in tumors was small (mean value of 0.015% of total injected amount per g of tumor occurring 1 day postadministration). Furthermore, both specific and nonspecific antibodies accumulated in normal lymph nodes to a significant extent (mean value of 0.0026% of total injected amount per g of tissue occurring 1 day postadministration). Knowledge of such data is essential prior to considering therapeutic uses of radiolabeled monoclonal antibodies.

Age-related radical-induced DNA damage is linked to prostate cancer.

We measured concentrations and ratios of mutagenic (8-OH) lesions to putatively nonmutagenic formamidopyrimidine (Fapy) lesions of adenine (Ade) and guanine (Gua) to elucidate radical (.OH)-induced changes in DNA of normal, normal from cancer, and cancer tissues of the prostate. The relationship between the lesions was expressed using the mathematical model log(10)[(8-OH-Ade + 8-OH-Gua)/(FapyAde + FapyGua)]. Logistic regression analysis of the log ratios for DNA of normal and cancer tissues discriminated between the two tissue groups with high sensitivity and specificity. Correlation analysis of log ratios for normal prostates revealed a highly significant increase in the proportion of mutagenic base lesions with age. Data from correlation analysis of the log ratios for normal tissues from cancer were consistent with an age-dependent, dose-response relationship. The slopes for both correlations intersected at approximately 61 years, an age when prostate cancer incidence is known to rise sharply. The age-related increase in the proportion of.OH-induced mutagenic base lesions is likely a significant factor in prostate cancer development.

The phosphorylation of p68, a calcium-binding protein associated with the human syncytiotrophoblast submembranous cytoskeleton, is modulated by growth factors, activators of protein kinase C and cyclic AMP.

The phosphorylation of the lipocortin-related protein, p68, found in Ca2+-dependent association with the submembranous cytoskeleton has been studied using isolated human placental syncytiotrophoblast plasma membrane vesicles. p68 undergoes rapid, cation-independent phosphorylation in unstimulated membrane vesicles which was inhibited, in a dose-dependent manner, by insulin, platelet-derived growth factor, macrophage colony stimulating factor, protein kinase C-activating phorbol esters and phosphatidylinositol-specific phospholipase C. Epidermal growth factor had no effect on overall p68 phosphorylation. Transferrin induced an increase in p68 phosphorylation. However, phosphotyrosine was detected in p68 after treatment with epidermal growth factor, macrophage colony stimulating factor or transferrin, whereas a reduction in p68 phosphorylation appeared to be restricted to serine. cAMP and both cholera and pertussis toxins inhibited p68 phosphorylation. Both toxins were synergistic with the effects of insulin and platelet-derived growth factor whilst being antagonistic to the effect of transferrin. Epidermal growth factor and both human and equine immunoglobulin G, all of which alone did not affect overall p68 phosphorylation, reduced cholera or pertussis toxin-induced inhibition of p68 phosphorylation. Several phosphatase inhibitors failed to prevent macrophage colony stimulating factor-induced reduction of p68 phosphorylation. These results indicate that (i) p68 is a potential substrate of receptor tyrosyl kinases, (ii) p68 is not phosphorylated by protein kinase C or cAMP-dependent kinase and (iii) p68 phosphorylation is inhibited by activation of multiple pathways including those employing diacylglycerol or cAMP as second messengers.

Human retroocular fibroblasts in vitro: a model for the study of Graves' ophthalmopathy.

Orbital connective tissue and extraocular muscles are histologically abnormal in patients with Graves' ophthalmopathy (GO). Although extraocular muscles have been extensively studied as a target for autoimmune attack in the disease, no system has been available to study retroocular fibroblasts in GO. We developed a technique to isolate fibroblasts from minced explants of connective tissue removed in the course of transantral orbital decompression surgery for GO. Postmortem specimens from individuals without evidence of thyroid disease were obtained from the same anatomical site. Confluent cells could be passaged at least 10 times with stable morphology and frozen with greater than 75% viability. An enzyme-linked immunosorbent assay was used to study the in vitro binding of serum immunoglobulin G (IgG) to these cells. We found no difference in the degree of specific binding between GO cells and cells from normal individuals. However, there was significantly greater binding of IgG from GO sera than of that from normal serum to retroocular GO fibroblasts. These results suggest that serum IgG autoantibodies against normal retroocular fibroblasts are present in some GO patients.

A novel isoform of human membrane cofactor protein (CD46) mRNA generated by intron retention.

The reverse transcription polymerase chain reaction (RT-PCR) with primers specific for each of the 14 exons of the human complement regulatory protein membrane cofactor protein (MCP;CD46) has been utilized to determine MCP mRNA transcript expression in peripheral blood mononuclear cells (PBMC). An additional transcript of a larger size than predicted was consistently detected in reactions with a sense primer for exon 7, that encodes the first alternatively spliced serine-threonine-rich region (ST-A), together with an antisense exon 12 primer, RT-PCR with primers for other exons both 5' and 3' of exon 7 further showed that these MCP transcripts contain additional sequences immediately both 5' and 3' to the exon 7-encoded sequence. Comparison of genomic DNA with cDNA by PCR, in combination with sequence analysis, demonstrated the presence of the complete invariant sequences of both introns adjacent to exon 7, i.e. intron 6 (411 bp) and intron 7 (127 bp). RT-PCR using primers specific for the intron 6 sequence, together with Southern and Northern blotting using an intron 6-specific probe, confirmed retention of this intron within a novel 4.8-kb mRNA transcript in human PBMC. Due to the presence of a stop codon within intron 6, translation would result in a novel truncated MCP isoform (MCPi) containing the four invariant short consensus repeat (SCR) regions and a unique C-terminal 39 amino acid transmembrane and cytoplasmic tail region that may promote endoplasmic reticulum retention.

Growth factor-induced release of a glycosyl-phosphatidylinositol (GPI)-linked protein from the HEp-2 human carcinoma cell line.

The release of a GPI-linked oncofetal protein (PLAP) from HEp-2 cells has been studied as an indicator of endogenous PI-specific PLC activation. A non-hydrolysable GTP analogue, EGF and insulin all produced a dose-dependent release of PLAP from these cells. This indicates that an increase in PLC activity following either growth factor binding or G protein activation may cause cellular release of PLAP.

The clinical, radiologic, and pathologic characterization of benign hepatic neoplasms. Alleged association with oral contraceptives.

Poor histopathologic documentation and confusing terminology have caused focal nodular hyperplasia (FNH) and liver cell adenoma (LCA) to be categorized together as "benign hepatomas." FNH and LCA are distinguishable grossly, microscopically, and ultrastructurally. In a majority of instances they may be differentiated by combined angiography and liver scan: FNH is hypervascular and exhibits normal uptake on scan whereas LCA is hypovascular and cold on scan. FNH almost always follows a benign course, rarely undergoing hemorrhagic necrosis and rupture. FNH does not possess malignant potential; the prognosis, even if unexcised, is excellent. Resection is indicated only if FNH is symptomatic. LCA often ruptures and its malignant potential remains uncertain; the prognosis is guarded and resection is indicated. The literature reported association between FNH and oral contraceptives is anecdotal. However, the recent marked increase in the incidence of LCA's, their almost exclusive occurrence in young women, and the consistent hormonal history strongly suggests an association between oral contraceptive use and LCA's, although here too, statistical evidence is lacking. Prognostic and therapeutic considerations mandate that a clear distinction be made between FNH and LCA.

A haemagglutination method for detection of rheumatoid factor using preserved erythrocytes covalently coated with human IgG.

The preparation and use of a new haemagglutination assay for rheumatoid factor using preserved erythrocytes covalently coated with human IgG is described. Test serum heat inactivation or adsorption with uncoated erythrocytes is not required. This human IgG-coated erythrocyte agglutination test (H/CEAT) appears stable and specific, is suitable for routine determinations of serum IgM-rheumatoid factor, is simple to perform and compares favourably in these properties with either the Rose-Waaler or latex agglutination assays for rheumatoid factor.

Evaluation of an ingestible telemetric temperature sensor for deep hyperthermia applications.

We have investigated the potential of an ingestible thermometric system (ITS) for use with a deep heating system. The ingestible sensor contains a temperature-sensitive quartz crystal oscillator. The telemetered signal is inductively coupled by a radiofrequency coil system to an external receiver. The sensors, covered with a protective silicon coating, are 10 mm in diameter and 20 mm long and are energized by an internal silver-oxide battery. Experimental studies were carried out to investigate the accuracy of the system and the extent of reliable operation of these sensors in an electromagnetic environment. Different measurements were repeated for five sensors. Calibration accuracy was verified by comparison with a Bowman probe in the temperature range 30 degrees C to 55 degrees C. Linear regression analysis of individual pill readings indicated a correlation within +/- 0.4 degrees C at 95% prediction intervals in the clinical temperature range of 35 degrees C to 50 degrees C. Further work is required to improve this accuracy to meet the quality assurance guidelines of +/- 0.2 degrees C suggested by the Hyperthermia Physics Center. Response times were determined by the exponential fit of heat-up and cool-down curves for each pill. All curves had correlation coefficients greater than 0.98. Time (mean +/- SE) to achieve 90% response during heat-up was 115 +/- sec. Time to cool-down to 10% of initial temperature was 114 +/- 4 sec. The effect of the external antenna and sensor spacing and the angle of orientation of the sensor relative to the antenna plane were also studied. Electromagnetic interference effects were studied by placing the sensor with a Bowman probe in a cylindrical saline phantom for the tests in an annular phase array applicator. Different power levels at three frequencies--80, 100, and 120 MHz--were used. Accurate temperature readings could not be obtained when the electromagnetic power was on because of interference effects with the receiver. However, the temperatures read with the ITS immediately after the electromagnetic power was switched off correlated well with the Bowman probe readings across the power categories and the three frequencies used. The phantom was heated to steady state, with a Bowman probe placed at the central axis of the cylinder used as control. During the heat-up period and the steady state, the mean difference (+/- SE) between the ITS and Bowman probe was 0.12 degrees C (+/- 0.05 degrees C).(ABSTRACT TRUNCATED AT 400 WORDS)

Immunoglobulin levels in dogs after total-body irradiation and bone marrow transplantation.

The influence of total-body irradiation (TBI) and autologous or allogeneic bone marrow transplantation on serum immunoglobulin subclasses was determined in a dog model. Only IgG1 levels decreased after low-dose (+/- 4.5 Gy) TBI, but levels of all immunoglobulin classes fell after high-dose TBI (8.5 GyX1 or 2X6.0 Gy). After autologous bone marrow transplantation IgM levels were the first and IgE levels were the last to return to normal. After successful allogeneic bone marrow transplantation prolonged low IgM and IgE levels were found but IgA levels increased rapidly to over 150% of pretreatment values. A comparison of dogs with or without clinical signs or graft-versus-host disease (GVHD), revealed no differences in IgM levels. Dogs with GVHD had higher IgA but lower IgE levels. Dogs that rejected their allogeneic bone marrow cells showed significant early rises in IgE and IgA levels in comparison with dogs with GVHD. These results differ from the observations made on Ig levels in human bone marrow transplant patients. No significant differences in phytohemagglutinin stimulation tests were found between dogs with or without GVHD or dogs receiving an autologous transplant for the first four months after TBI and transplantation. An early primary or secondary involvement of humoral immunity in GVHD and graft rejection in dogs is postulated.

Determinants of immunological responsiveness in recurrent spontaneous abortion.

A defined group of 20 women suffering recurrent spontaneous abortions of unknown etiology was studied for determinants relevant to immune responsiveness. A low prevalence of serum anti-CMV antibodies (35%; cf, 65% in controls)--but not anti-herpes-simplex-virus or Epstein-Barr virus antibodies--was noted. Only two (10%) of these women had lymphocytotoxic antibodies following their repeated pregnancies; low titer anti-sperm antibody was present in two other of these women. Whereas there was no significantly increased sharing of HLA-A or -B antigens within these couples compared with controls, there was an increased incidence of apparent HLA-B antigen homozygosity in the women. These data indicate a degree of immunological nonresponsiveness both to cytomegalovirus and to cell-surface alloantigens in habitually aborting women and, together with MLC data, provide further evidence that immunogenetic events may be relevant to reproductive success.

Evaluation of sequential plasma and urinary tumor necrosis factor alpha levels in renal allograft recipients.

The macrophage cytokine tumor necrosis factor-alpha is released early in immune activation and may be detected in the peripheral circulation. This study has investigated the occurrence of plasma and urinary TNF in 30 renal allograft recipients. Although circulating TNF may be detected in 20% of pretransplant or normal control samples, levels were significantly elevated during 65% of allograft rejection episodes. Plasma TNF levels did not rise in graft failure due to acute tubular necrosis, but were always highly raised in systemic infection. In contrast, urinary TNF was only detected in association with acute rejection (49%) or tubular necrosis (14%), and no controls had detectable urinary TNF. These findings indicate that evaluation of circulating and excreted TNF may give further insight into the immunobiology of graft rejection.