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PubMed1995

Texture analysis of technegas lung ventilation images.

Technegas lung ventilation images sometimes have 'hot spots', particularly in patients with respiratory disease. A novel technique is presented for quantifying this 'spottiness' using morphological texture analysis. A set of 32 images from patients with various respiratory diseases is studied. Images are filtered at a range of scales using morphological opening, and the slopes of image metrics versus structuring element size are used as texture parameters. The results are compared with the opinions of three experienced nuclear medicine physicians who have classified the images into two groups, 'spotty' and 'non-spotty', and have ranked the former. For the spotty images, the computer and observer ranks are compared; the highest correlation is rs = 0.66 (p = 0.01) for a single parameter, and rs = 0.71 (p < 0.01) for a combination of two parameters. Using a pair of parameters, 83% and 90% correct classification rates are obtained for the spotty and non-spotty classes, respectively. It is concluded that these texture parameters provide a useful measure of image spottiness, and it is demonstrated that this technique is superior to previously published methods. The practical value of the technique is illustrated using two applications.

Humans↗
PubMed2005

Electrochemical reduction and flow detection of iodate on (Bu4N)2Mo6O19 self-assembled monolayer.

A stable monolayer of the inorganic-organic hybrid polyoxometalate (Bu4N)2Mo6O19, denoted as Mo6O19, was formed on a sodium-3-mercapto-1-propanesulfonate (MPPS)-covered gold electrode surface, interlaced with an anionic poly(dimethyldiallylammonium chloride) (PDDA) binding layer based on the electrostatic self-assembled (ESA) technique. Electrochemical characterization of the Mo6O19 self-assembled thin films on the solid surface by cyclic voltammetry and AC impedance spectroscopy revealed a stable and sensitive electrocatalytic response to the reduction of iodate. Iodate was determined amperometrically through a flow injection cell at the modified electrode in the concentration range of 1.0 x 10(-6) to 1.0 x 10(-1) M with a detection limit of 8 x 10(-8) M (signal-to-noise ratio = 3). Performance was improved to meet practical needs compared with previously reported analogues.

Electrochemistry↗
PubMed2003

Rapid assignment of swine leukocyte antigen haplotypes in pedigreed herds using a polymerase chain reaction-based assay.

We present a simple assay to determine the swine leukocyte antigen (SLA) haplotypes of animals within two experimental populations of MHC defined miniature pigs. The Yucatan miniature pigs have four founder haplotypes ( w, x, y, z) and one recombinant haplotype ( q). The NIH miniature pigs have three founder haplotypes ( a, c, d) and two recombinant haplotypes ( f, g). Because most crossovers occur between the class I and class II regions, haplotypes can be assigned by typing one class I locus and one class II locus for practical purposes. We have previously characterized these seven founder haplotypes by sequencing the cDNA of three SLA class I loci, designated as SLA-1, SLA-3 and SLA-2 and four SLA class II loci, SLA-DQA1, SLA-DQB1, SLA-DRA1 and SLA-DRB1. These sequences were used to design allele-specific primers to amplify one MHC class I and one MHC class II gene for each haplotype. Primers were tested for specificity in homozygous and heterozygous animals. Positive control primers were also designed to amplify a portion of the E-selectin or alpha-actin gene and multiplexed with the allele-specific primers to check for false negatives. This combination of allele-specific and positive control primers produced specific and robust PCR-site-specific primer assays for assigning SLA haplotypes in the two populations.

Animals↗
PubMed1989

Thin-layer chromatography can resolve phosphotyrosine, phosphoserine, and phosphothreonine in a protein hydrolyzate.

A solution of propionic acid, 1 M ammonium hydroxide, and isopropyl alcohol (45/17.5/17.5, v/v) was the ascending solvent in the separation of phosphotyrosine, phosphothreonine, and phosphoserine by thin-layer chromatography. The immobile phase was cellulose. The relative migrations were 0.44, 0.38, and 0.2, respectively. A previously described thin-layer system consisting of isobutyric acid and 0.5 M ammonium hydroxide (50/30, v/v) gave very similar relative migrations. To determine the usefulness of thin-layer chromatography in phosphoamino acid analysis, the propionic acid/ammonium hydroxide/isopropyl alcohol solution was used to characterize phosphorylated residues in a plasma membrane protein which is a substrate for the insulin receptor kinase, in insulin receptor phosphorylated histone H2B, and in an in vivo phosphorylated 90000-Da protein from IM9 cells. 32P-labeled proteins were separated by dodecyl sulfate-gel electrophoresis, digested with trypsin, and then hydrolyzed with 6 N HCl, 2 h, 110 degrees C. Following thin-layer chromatography of the hydrolyzates and autoradiography, phosphotyrosine was detected in insulin receptor substrates, and phosphoserine and phosphothreonine were found in the in vivo-phosphorylated protein. This study supports previous reports about the practicality of thin-layer chromatography in phosphoamino acid analysis and it demonstrates that a propionic acid, ammonium hydroxide, isoprophyl alcohol solution may be a useful ascending solvent mixture for this purpose.

Animals↗
PubMedDate not supplied

New stereological methods for counting neurons.

The issue of whether or not neurons die with age is of fundamental importance for understanding senescent decline in motor, sensory, and cognitive functions. Yet after over 100 years of attempts to quantify age-related neuron loss, this fundamental issue is "swirling in controversy" and the results of numerous studies addressing this issue "rife with confusion and seemingly contradictory data" (7). This is in large part due to deficiencies in the way we have thought about what constitutes evidence for neuron loss and deficiencies in the methods that have been available for counting neurons. Over the past several years, a new generation of stereological principles have been developed that have made it possible to identify and eliminate these deficiencies. Although there are now a number of review articles that briefly describe these and other new stereological principles (4,9,13,14,15,18,23), for the most part detailed descriptions of the new principles for counting neurons are found in specialized literature and are accompanied by new terms and concepts that have overwhelmed potential users and inhibited their adoption. In this essay, I describe the principles and concepts that are involved in the new stereological approach to neuron counting and discuss why the data obtained from their application represent improvements over those obtained with previously available techniques. A practical guide to the application of the principles to counting neurons or any other cell, organelle, or object present in sectioned material has been included as an appendix.

Aging↗
PubMed1991

Assessing comprehensive nursing performance: the Objective Structural Clinical Assessment (OSCA). Part 1--Development of the assessment strategy.

Nursing courses in Australia are preparing graduates for comprehensive practice within Universities. The evaluation of safe and effective comprehensive nursing performance requires the consideration of a much broader range of practice competencies than has previously been the case. In particular there is a need to explore integrated assessment approaches that closely resemble the realities of the health care setting. Part 1 of this paper provides an overview of the Objective Structured Clinical Assessment (OSCA) which it is suggested is an effective way of assessing student comprehensive nursing performance. Some theoretical considerations in OSCA development are discussed and then an outline of the processes involved in designing and implementing an OSCA provided. Part 2 describes an evaluation project supported by the NSW Nurses' Registration Board. The aim of the study was to determine the validity and reliability of the use of the OSCA as an integrated assessment tool as a measurement of the extent to which a student nurse can plan and deliver safe and effective comprehensive nursing care.

Australia↗
PubMed2006

Breast reconstruction with gluteal artery perforator flaps.

BACKGROUND: Several alternatives exist for breast cancer reconstruction with perforator flaps. For those patients in whom the buttock is the best choice as a source for autologous tissue, the IGAP and SGAP flaps are an excellent option. These flaps allow the reliable transfer of skin and soft tissue from the buttock without the associated donor site morbidity of a muscle flap. INDICATIONS: Most women requiring tissue transfer to the chest from the buttock for breast reconstruction or other reasons are candidates for IGAP or SGAP flaps. Do to an improved donor site contour and scar, we now prefer to use the IGAP to the SGAP flap. Absolute contraindications specific to perforator flap breast reconstruction in our practice include history of previous liposuction of the donor site or active smoking (within 1 month prior to surgery). ANATOMY AND TECHNIQUE: IGAP and SGAP flaps are based on perforators from either the superior or inferior gluteal artery. These perforators are carefully dissected free from the surrounding gluteus maximus muscle, which is spread in the direction of the muscle fibres and safely preserved. The vascular pedicle is anastomosed to recipient vessels in the chest and the donor site closed primarily. CONCLUSIONS: IGAP and SGAP flaps allow the safe and reliable transfer of tissue from the buttock for breast reconstruction as an alternative to soft tissue transfer from an abdominal donor site or even as a first choice in selected patients.

Arteries↗
PubMed2006

Chemo-enzymatic synthesis of allyl penta-N-acetyl-chitopentaose.

Cell density cultivation of recombinant Escherichia coli strains harboring the nodC gene (encoding chitooligosaccharide synthase) from Azorhizobium caulinodans has been previously described as a practical method for the preparation of gram-scale quantities of penta-N-acetyl-chitopentaose. We have now extended this method to the production of allylated derivative of penta-N-acetyl-chitopentaose by using allyl 2-acetamido-2-deoxy-beta-d-glucopyranoside (2) as the initial acceptor for the synthesis of target pentaoside in vivo.

Carbohydrate Sequence↗
PubMed2004

Retrospective evaluation of interferon-beta treatment in subacute sclerosing panencephalitis.

BACKGROUND: Few effective treatment methods are available for subacute sclerosing panencephalitis (SSPE),an infection associated with the measles virus. Interferons have shown some benefit in previous studies and clinical practice. OBJECTIVE: The purpose of this study was to compare the efficacy of 2 different regimens of interferon-beta(IFN-beta) in the treatment of SSPE in pediatric patients. METHODS: We retrospectively compared the results obtained with 2 regimens of IFN-beta1a: 60 microg administered intramuscularly once weekly (IFN-beta 1/wk), or 22 microg administered subcutaneously 3 times per week (IFN-beta 3/wk). All patients also received oral inosiplex 50 to 100 mg/kg daily, a treatment known to have partial efficacy in SSPE. Patients who continued treatment for at least 3 months and had at least 1 year of follow-up data were evaluated. Clinical parameters included the Neurological Disability Index (NDI), a measurement of mental, motor, and sensory functions; disease stage; and mental status. Data obtained at 6 and 12 months were compared with those at the time of diagnosis, and the percent change from baseline was calculated. A satisfactory clinical response was defined as reduction or stabilization of the NDI or stage improvement at 6 or 12 months. RESULTS: Patients treated with IFN-beta 3/wk had increased survival time (P < 0.02) and higher clinical response rates compared with those treated with IFN-beta 1/wk (P < 0.05). When stage 2 and stage 3 patients were evaluated separately, survival was significantly longer (P = 0.007) and the rate of progression slower in both stage groups with IFN-beta 3/wk. CONCLUSION: The results obtained for this patient sample suggest that IFN-beta administered subcutaneously times per week combined with inosiplex may be an effective treatment option in SSPE. This treatment regimen warrants further study.

Adjuvants, Immunologic↗
PubMed2006

The optimisation of radiological protection: broadening the process. ICRP publication 101. Approved by the Commission in September 2005.

The principle of optimisation of radiation protection is defined by the Commission as the source-related process to keep the magnitude of individual doses, the number of people exposed, and the likelihood of potential exposure as low as reasonably achievable below the appropriate dose constraints, with economic and social factors being taken into account. According to the revised recommendations of ICRP, this process of optimisation below constraint should be applied whatever the exposure situation; i.e. planned, emergency, and existing. The previous recommendations for the practical implementation of the optimisation process are still valid. It must be implemented through an ongoing, cyclical process that involves the evaluation of the exposure situation to identify the need for action, the identification of the possible protective options to keep the exposure as low as reasonably achievable, the selection of the best option under the prevailing circumstances, the implementation of the selected option through an effective optimisation programme, and regular review of the exposure situation to evaluate if the prevailing circumstances call for the implementation of corrective protective actions. However, the way in which the optimisation process should be implemented is now viewed more broadly to reflect the increasing role of individual equity, safety culture, and stakeholder involvement in our modern societies. This report is a consolidation and an evolution of the Commission's recommendations concerning the optimisation principle. After some background information on the foundation and evolution of the principle, this report describes the main characteristics of the process, addresses the issue of exposure distribution in that process, and provides the basic requirements for its application in operation and regulation. A description of decision-aiding techniques commonly used for practical implementation of the optimisation process is provided in Annex A.

Body Burden↗
PubMed2004

Racial/ethnic disparities in the diagnosis of otitis media in infancy.

OBJECTIVE: Otitis media (OM) is an extremely common pediatric diagnosis. Several risk factors have been associated with OM, but the relationship between OM and race/ethnicity remains controversial. We sought to define the relationship between OM diagnosis and race/ethnicity in infants. METHODS: By multivariable logistic regression, we evaluated the association between OM diagnosis and race/ethnicity in 11,349 non-low-birthweight infants who were participants in a prospective cohort study of infant care practices. RESULTS: As in previous studies, breastfeeding was associated with a decreased risk of OM diagnosis while other factors were independently associated with a substantially increased risk of OM diagnosis: out-of-home daycare, multiple children living in the home, and mother's multiparity. Daycare was associated with a "dose effect" in that the risk of OM diagnosis increased with an increasing number of children in the daycare. While the crude analysis suggested little relation of OM diagnosis and race/ethnicity, the association was confounded by several covariates including maternal marital status, number of children living in the home, breastfeeding status, and maternal age. After adjustment for relevant confounders, Black (OR 0.74; 95% CI 0.61-0.89) and Asian infants (OR 0.77; 95% CI 0.57-1.0]) were less likely to be diagnosed with OM than White infants. CONCLUSIONS: This large prospective study confirms previous risk factors for OM and demonstrates a strong "dose effect" of the size of daycare centers on OM. The study also demonstrates that the association between race/ethnicity and OM diagnosis is confounded by social factors. After adjusting for such factors, Black and Asian infants are less likely to be diagnosed with OM than White infants. The reason for this racial disparity remains unknown.

Black or African American↗
PubMed2004

Histomorphologic classification of recurrent saphenofemoral reflux.

OBJECTIVE: The purpose of this study was to determine the apparent mechanisms of recurrent saphenofemoral junction (SFJ) reflux on the basis of the histologic features of intentionally sampled specimens from repeat operations in groins with symptomatic reflux after SFJ ligation and great saphenous vein (GSV) stripping. PATIENTS AND METHODS: Ninety-one samples obtained at repeat operation in patients with symptomatic recurrent groin reflux were evaluated histologically, including the number of venous lumens, the structure of the venous wall, and the surrounding tissue. All repeat operation specimens were obtained in our Department of Vascular Surgery; the original operations in our patients (age 56 +/- 11 years) had been performed in different centers and private practices 12.1 +/- 8.1 years previously. RESULTS: Single-channel recurrence was observed in 63 groins. In 62 the vein wall structure was complex; and 18 demonstrated venous valves. These vessels could be classified as residual stumps of the GSV. Just one single-channel recurrent vessel lined with endothelium and surrounded by scar tissue was detected, and was judged to be neovascular. Multichannel recurrent vessels were found in 28 groins. Twenty-three of these were thin-walled tortuous vessels embedded in scar tissue, and were interpreted as neovascular; 4 were multiple vessels surrounded by fatty tissue and were classified as venule hypertrophy; and 1 was a lymph node that contained numerous channels, and was attributed to lymphovenous connections. CONCLUSION: Original misidentification of the SFJ, as evidenced by an identifiable GSV stump with appropriate histologic features, characterized 68% (62 of 91) of these symptomatic groins. Neovascularity, marked by multiple irregular channels with an incomplete wall structure, was observed in 26% of the groins (24 of 91), accounting for 94% of the recurrent vessels. The findings at repeat operation, supported by analysis of histologic tissue sections, imply that better supervision and training or case concentration in centers of excellence should be more effective in decreasing the incidence of recurrent SFJ reflux after SFJ ligation and GSV stripping than putative operative maneuvers directed at reducing neovascularization.

Adult↗
PubMed2004

The beneficial effects of specialist thoracic surgery on the resection rate for non-small-cell lung cancer.

We aimed to evaluate the effect of the appointment of a dedicated specialist thoracic surgeon on surgical practice for lung cancer previously served by cardio-thoracic surgeons. Outcomes were compared for the 240 patients undergoing surgical resection for lung cancer in two distinct 3-year periods: Group A: 65 patients, 1994-1996 (pre-specialist); Group B: 175 patients, 1997-1999 (post-specialist). The changes implemented resulted in a significant increase in resection rate (from 12.2 to 23.4%, P < 0.001), operations in the elderly (over 75 years) and extended resections. There were no significant differences in stage distribution, in-hospital mortality or stage-specific survival after surgery. Lung cancer surgery provided by specialists within a multidisciplinary team resulted in increased surgical resection rates without compromising outcome. Our results strengthen the case for disease-specific specialists in the treatment of lung cancer.

Aged↗
PubMed2005

Dissociation between emotion and personality judgments: convergent evidence from functional neuroimaging.

Cognitive neuroscientists widely agree on the importance of providing convergent evidence from neuroimaging and lesion studies to establish structure-function relationships. However, such convergent evidence is, in practice, rarely provided. A previous lesion study found a striking double dissociation between two superficially similar social judgment processes, emotion recognition and personality attribution, based on the same body movement stimuli (point-light walkers). Damage to left frontal opercular (LFO) cortices was associated with impairments in personality trait attribution, whereas damage to right postcentral/supramarginal cortices was associated with impairments in emotional state attribution. Here, we present convergent evidence from fMRI in support of this double dissociation, with regions of interest (ROIs) defined by the regions of maximal lesion overlap from the previous study. Subjects learned four emotion words and four trait words, then watched a series of short point-light walker body movement stimuli. After each stimulus, subjects saw either an emotion word or a trait word and rated how well the word described the stimulus. The LFO ROI exhibited greater activity during personality judgments than during emotion judgments. In contrast, the right postcentral/supramarginal ROI exhibited greater activity during emotion judgments than during personality judgments. Follow-up experiments ruled out the possibility that the LFO activation difference was due to word frequency differences. Additionally, we found greater activity in a region of the medial prefrontal cortex previously associated with "theory of mind" tasks when subjects made personality, as compared to emotion judgments.

Adult↗
PubMed2005

Comparison of two dimensional and three dimensional radiotherapy treatment planning in locally advanced non-small cell lung cancer treated with continuous hyperfractionated accelerated radiotherapy weekend less.

BACKGROUND AND PURPOSE: Patients with inoperable non-small cell lung cancer being treated with continuous hyperfractionated accelerated radiotherapy weekend less (CHARTWEL) were planned and treated with a three dimensional (3D) conformal protocol and comparison made with two dimensional (2D) planning, as used previously, to compare past practice and methods. PATIENTS AND METHODS: Twenty-four patients were planned initially using 3D and then replanned using a 2D system. The 2D plans were transferred onto the 3D system and recalculated. Dose volume histograms could then be constructed of planning target volumes for phases 1 and 2 (PTV 1 and 2, respectively), lung and spinal cord for the 2D plans and compared with the 3D plans. RESULTS: There was a significantly lower absolute dose to the isocentre with 2D compared to 3D planning with dose reductions of 3.9% for phase 1, 4.4% for phase 2 and 4.7% for those treated with a single phase. Maximum dose to spinal cord was greater in 17 of the 24 2D plans with a median dose reduction of 0.82 Gy for 3D (P=0.04). The percentage volume of whole lung receiving > or =20 Gy (V20) was greater in 16 of the 24 2D plans with a median reduction in V20 of 2.4% for 3D (P=0.03). CONCLUSIONS: A lower dose to tumour was obtained using 2D planning due to the method of dose calculation and spinal cord and lung doses were significantly higher.

Aged↗
PubMed2005

Contrast media hypersensitivity--scope of the problem.

Hypersensitivity reactions to contrast media (CM) are frequent causes of anaphylactically induced fatalities. Adverse events after CM exposure are classified into immediate and non-immediate reactions, with differing pathomechanisms. In the majority of patients with immediate reactions, IgE-mediated allergy can not be demonstrated and the underlying mechanism remains unknown. However, recent data has provided evidence for skin test positivity and/or specific IgE in some patients with severe reactions. Cell-mediated hypersensitivity is the responsible mechanism for the majority of non-immediate skin eruptions. Skin tests have been employed to confirm this hypersensitivity. Previous reactors have an increased risk to develop new reactions upon repeated exposure, however, other risk factors are poorly defined. The use of skin tests for the selection of a "safe" CM is controversially discussed; information on sensitivity and specificity is lacking. New in-vitro assays have to be developed and/or validated. Premedication of previous reactors is common practice among radiologists, however, its precise role in the prevention of severe CM reactions to lower-osmolality CM has not been demonstrated. Thus, the main future tasks are to develop and validate allergic tests procedures, which may identify patients at risk and/or may confirm CM tolerance, and to reassess the value of different premedications in the prevention of hypersensitivity reactions.

Anaphylaxis↗
PubMed1994

Tethered particle motion method for studying transcript elongation by a single RNA polymerase molecule.

Schafer et al. (Nature 352:444-448 (1991)) devised the tethered particle motion (TPM) method to detect directly the movement of single, isolated molecules of a processive nucleic acid polymerase along a template DNA molecule. In TPM studies, the polymerase molecule is immobilized on a glass surface, and a particle (e.g., a 0.23 microns diameter polystyrene bead) is attached to one end of the enzyme-bound DNA molecule. Time-resolved measurements of the DNA contour length between the particle and the immobilized enzyme (the "tether length") are made by determining the magnitude of the Brownian motion of the DNA-tethered particle using light microscopy and digital image processing. We report here improved sample preparation methods that permit TPM data collection on transcript elongation by the Escherichia coli RNA polymerase at rates (approximately 10(2)-fold higher than those previously obtained) sufficient for practical use of microscopic kinetics techniques to analyze polymerase reaction mechanisms. In earlier TPM experiments, calculation of tether length from the observed Brownian motion was based on an untested numerical simulation of tethered bead Brownian motion. Using the improved methods, we have now empirically validated the TPM technique for tether lengths of 308-1915 base pairs (bp) using calibration specimens containing particles tethered by individual DNA molecules of known lengths. TPM analysis of such specimens yielded a linear calibration curve relating observed Brownian motion to tether length and allowed determination of the accuracy of the technique and measurement of how temporal bandwidth, tether length, and other experimental variables affect measurement precision. Under a standard set of experimental conditions (0.23 microns diameter bead, 0.23 Hz bandwidth, 23 degrees), accuracy is 108 and 258 bp r.m.s. at tether lengths of 308 and 1915 bp, respectively. Precision improves linearly with decreasing tether length to an extrapolated instrumentation limit of 10 bp r.m.s. and improves proportionally to the inverse square root of measurement bandwidth (1.9 x 10(2) bp Hz-1/2 for 1090-bp tethers). Measurements on large numbers of individual polymerase molecules reveal that time-averaged single-molecule elongation rates are more variable than is predicted from the random error in TPM measurements, demonstrating that the surface-immobilized RNA polymerase molecules are kinetically heterogeneous.

Biophysical Phenomena↗
PubMed2003

Wheat gliadin induces apoptosis of intestinal cells via an autocrine mechanism involving Fas-Fas ligand pathway.

Wheat gliadin and other cereal prolamins have been said to be involved in the pathogenic damage of the small intestine in celiac disease via the apoptosis of epithelial cells. In the present work we investigated the mechanisms underlying the pro-apoptotic activity exerted by gliadin-derived peptides in Caco-2 intestinal cells, a cell line which retains many morphological and enzymatic features typical of normal human enterocytes. We found that digested peptides from wheat gliadins (i) induce apoptosis by the CD95/Fas apoptotic pathway, (ii) induce increased Fas and FasL mRNA levels, (iii) determine increased FasL release in the medium, and (iv) that gliadin digest-induced apoptosis can be blocked by Fas cascade blocking agents, i.e. targeted neutralizing antibodies. This favors the hypothesis that gliadin could activate an autocrine/paracrine Fas-mediated cell death pathway. Finally, we found that (v) a small peptide (1157 Da) from durum wheat, previously proposed for clinical practice, exerted a powerful protective activity against gliadin digest cytotoxicity.

Apoptosis↗