Does selecting one visual object from several require inhibition of the actions associated with nonselected objects?

Four experiments are described in which 1 visual object (the target) was selected from another (the distractor) according to its color (Experiments 1, 2, and 4) or its relative location (Experiment 3) and then was classified according to a simple geometric property. Object classification was signaled as fast as possible by a precision or power grip response, and this grip was either compatible or incompatible with either object. When targets were selected by color, target-compatible grip responses were facilitated, but distractor-compatible grip responses were impaired. When targets were selected by location, similar results were obtained for target-compatible grip responses, but not distractor-compatible grip responses. These data are explained in terms of the involvement of action codes in object-level selection.

The role of visual attention in action priming

It has been demonstrated that the task-irrelevant left-right orientation of an object is capable of facilitating left-right-hand responses when the object is orientated towards the responding hand. We investigated the role of attention in this orientation effect. Experiment 1 showed that object orientation facilitates responses of the hand that is compatible with the object's orientation, despite the entire object being irrelevant. However, when a task-relevant fixation point was displayed over the prime object in Experiment 2, the effect was not observed. Together Experiments 1 and 2 suggest that the orientation information of viewed objects primes the action selection processes even when the object is irrelevant, but only when attention is not allocated to a competing stimulus during the prime presentation. Experiment 3 suggested that the elimination of the effect in Experiment 2 could not be attributed to the elimination of an attentional shift to the graspable part of the prime. Finally, Experiment 4 showed that object orientation can evoke an abstract response code, influencing the selection of finger responses.

From scans to sutures: computer-assisted orthopedic surgery in the twenty-first century

Computer-assisted surgery is the process of using medical images, such as CT scans, X-ray fluoroscopy, or 3D ultrasound, to improve patient care. A typical surgical procedure begins by acquiring and processing a CT scan with specially developed image-analysis software. A surgeon then performs a "virtual surgery" on the patient to develop a preoperative plan. In the operating room the medical image is registered to the patient's anatomy by finding an optimal rigid-body transformation. This transformation allows an object or motion in one coordinate frame to be represented in the other frame, and thus a surgeon can visualize the location of an instrument deep within concealed anatomy while avoiding structures at risk. The operating surgeon can also use computer-tracked fluoroscopy or ultrasound for 3D guidance. For the past seven years, our interdisciplinary research group has been investigating fundamental problems in orthopedic surgery of bones and joints. This paper is an overview of the problems and solutions that have been tested in a set of pilot clinical trials in which we have treated more than 250 patients for early or advanced arthritis, poorly healed bone fractures, and treatment of deep bone tumors.

Visual object affordances: object orientation

Five experiments systematically investigated whether orientation is a visual object property that affords action. The primary aim was to establish the existence of a pure physical affordance (PPA) of object orientation, independent of any semantic object-action associations or visually salient areas towards which visual attention might be biased. Taken together, the data from these experiments suggest that firstly PPAs of object orientation do exist, and secondly, the behavioural effects that reveal them are larger and more robust when the object appears to be graspable, and is oriented in depth (rather than just frontally) such that its leading edge appears to point outwards in space towards a particular hand of the viewer.

An integrative review of Canadian childhood obesity prevention programmes

To examine successful Canadian nursing and health promotion intervention programmes for childhood obesity prevention during gestation and infancy, an integrative review was performed of the literature from 1980 to September 2005. The following databases were used: PubMed; Cochrane Database of Systematic Reviews; Cochrane Controlled Trials Register; Database of Abstracts of Reviews of Effects; ACP Journal Club; MEDLINE; EMBASE; CINAHL; Web of Science; Scopus; Sociological Abstracts; Sport Discus; PsycInfo; ERIC and HealthStar. MeSH headings included: infancy (0-24 months), gestation, gestational diabetes, nutrition, prenatal care, pregnancy, health education, pregnancy outcome, dietary services with limits of Canadian, term birth. Of 2028 articles found, six Canadian childhood obesity prevention programmes implemented during gestation and/or infancy were found; three addressed gestational diabetes with five targeting low-income Canadian urban and/or Aboriginal populations. No intervention programmes specifically aimed to prevent childhood obesity during gestation or infancy. This paucity suggests that such a programme would be innovative and much needed in an effort to stem the alarming increase in obesity in children and adults. Any attempts either to develop new approaches or to replicate interventions used with obese adults or even older children need careful evaluation and pilot testing prior to sustained use within the perinatal period.

Local and global affordances and manual planning

The present study aimed to demonstrate that motor planning processes are affected by ignored affordances of a main body of an object. Participants were asked to select the hand of response according to the property of the local component (a stalk) of the object (a fruit) while they were holding a precision or a power grip devices. The size of a main body of an object was observed to prime hand selection processes asymmetrically. Right-hand responses were facilitated when the stalk was a part of a precision grip object (e.g. a strawberry) or displayed alone. In contrast, left-hand responses were facilitated when the stalk was a part of a power grip object (e.g. an apple). This data supported our previously presented view that the different hemispheres have differential roles in the early planning of manual actions. The object information that is relevant to precision grip planning appears to be processed predominantly in the left-hemisphere whereas the information that is relevant to power grip planning appears to be processed predominantly in the right-hemisphere. In Experiment 3, the irrelevant fruit body had a slight effect on motor planning even though the stalk was spatially separated from the fruit body. The priming effect was entirely eliminated when, in addition to the spatial separation, the stalk was semantically disassociated from the fruit body (Experiment 4), and when the objects used in Experiment 1 were replaced by two dimensional abstract objects (Experiment 2). Experiments 2, 3 and 4 suggested that affordances of an irrelevant main body of an object influences motor planning processes only when the local target component of the object is analysed as a meaningful part of a graspable object.

Iron genes, iron load and risk of Alzheimer's disease

BACKGROUND

Compound heterozygotes of the haemochromatosis gene (HFE) variants, H63D and C282Y, have raised transferrin saturation compared with that in the wild type. In the cohort of the Oxford Project To Investigate Memory and Ageing (OPTIMA), bicarriers of the HFE C282Y and the transferrin C2 gene variants are at five times greater risk of developing Alzheimer's disease; the addition of HFE H63D may raise the risk still further.

OBJECTIVE

To investigate transferrin saturation by HFE and transferrin genotype among people without dementia-that is, controls and those with mild cognitive impairment (MCI)-and also among those with Alzheimer's disease.

METHODS

Serum iron status and genotype were examined of 177 patients with Alzheimer's disease, 69 patients with MCI and 197 controls from the OPTIMA cohort.

RESULTS

Although each of these variants alone had relatively little effect on iron status, the combination of either HFE C282Y and HFE H63D or of HFE C282Y and transferrin C2 markedly raised transferrin saturation in those without dementia, but had little effect in those with mature Alzheimer's disease.

CONCLUSIONS

These combinations may raise the risk for Alzheimer's disease, owing to higher iron loads and therefore oxidative stress in the preclinical phase. If replicated, these findings will have implications for the prevention of Alzheimer's disease.

Cognitive deficits and degeneration of interneurons in HIV+ methamphetamine users

The cellular basis for cognitive deficits in HIV+ patients with and without a history of methamphetamine (METH) use is unclear. We found that HIV+ METH users had more severe loss of interneurons that was associated with cognitive impairment. Compared with other markers, loss of calbindin and parvalbumin interneurons in the frontal cortex was the most significant correlate to memory deficits, suggesting a role in neurobehavioral alterations of HIV+ METH users.

A sample distribution programme for erythropoietin

A survey was sent to laboratories participating in the United Kingdom External Quality Assessment Service (UKNEQAS) Haematinics Scheme about the measurement of serum erythropoietin (EPO). Six laboratories, from a total of 120 that returned the survey, were measuring serum EPO concentrations by commercially available immunoassays on site in the United Kingdom. The workload of the laboratories varied from up to 100 specimens per month to more than 100 specimens analysed per week. All laboratories included control material in the assays and none of the laboratories was participating in an external quality assessment scheme for serum EPO. Four laboratories agreed to take part in the first sample distribution programme, with five and six laboratories participating in distributions 2 and 3 respectively. The results from eight kits were compared from the three distributions over a 2-year period. The serum EPO concentrations for the methods showed some variation across the range of 2.9-200 U/l when the serum EPO concentrations for each method were compared with the whole method mean. The results from this scheme have identified a role for an external quality assessment scheme for serum EPO measurements.

Percutaneous management of perianastomotic stenosis in arteriovenous fistulae: Results of a prospective study

Surgical creation of new anastomosis has been proposed as the preferred treatment for perianastomotic stenoses of fistulae. However, disadvantages of surgical approach have included (1) frequent conversion of fistula to a graft by using synthetic graft material to create a new anastomosis, (2) shortening the length of the cannulation segment by proximal autologous arteriovenous neoanastomosis, and (3) abandoning the fistula altogether in favor of a synthetic graft. We report the results of a prospective study using percutaneous balloon angioplasty (PTA) to treat fistulae with perianastomotic lesions. Seventy-three consecutive patients undergoing 112 PTA procedures for the treatment of perianastomotic lesions were studied. Primary and secondary patency rates were calculated. Procedure success, procedure-related complications, and conversion of fistulae to grafts were recorded. The initial success rate was 97%. The degree of stenosis before and after PTA was 81 +/- 9 and 11+/-11%, respectively. Primary patency rates at 6, 12, and 18 months were 75, 51, and 41%, respectively. Secondary patency rates at 6, 12, and 18 months were 94, 90, and 90%, respectively. Grade I hematoma occurred in three and vein rupture in two cases. No grafts were inserted. These outcomes are superior to those that have been reported for surgery. The outpatient PTA is safe and effective for the management of perianastomotic stenosis. Because of its advantage of fistula preservation, the percutaneous approach should be considered as the preferred first-line therapy for the management of perianastomotic fistula lesions.

The potentiation of two components of the reach-to-grasp action during object categorisation in visual memory

Stimulus-Response Compatibility Effects have been reported for several components of the reach-to-grasp action during visual object recognition [Tucker, M., & Ellis, R. (1998). On the relations between seen objects and components of potential actions. Journal of Experimental Psychology: Human Perception and Performance, 24, 830-846; Ellis, R., & Tucker, M. (2000). Micro-affordance: The potentiation of actions by seen objects. British Journal of Psychology, 91, 451-471; Tucker, M., & Ellis, R. (2001). The potentiation of grasp types during visual object categorization. Visual Cognition, 8, 769-800; Creem, S. H., & Proffitt, D. R. (2001). Grasping objects by their handles: A necessary interaction between cognition and action. Journal of Experimental Psychology: Human Perception and Performance, 27, 218-228; Craighero, L. Bello, A. Fadiga, L., & Rizzolatti, G. (2002). Hand action preparation influences the responses to hand pictures. Neuropsychologia, 40, 492-502]. The present study investigates compatibility effects for two elements of reach-to-grasp action during the visual mental imagery of objects-the compatibility of an object for grasping with a power and precision grasp, and the orientation of an object (left/right) for grasping by a particular hand (left/right). Experiment 1 provides further evidence for compatibility effects of a 'seen' object for grasping with a power and precision grasp. The experiment shows that compatibility effects are obtainable when an object is presented in an array of four objects and not just on its own. Experiment 2 provides evidence that compatibility effects of an object for grasping with a power and precision grasp can also be observed when participants make an action response to an object 700 ms after it has been removed from view. Experiment 3 investigates compatibility effects for the orientation of an object for grasping by a particular hand during visual mental imagery, but finds no evidence for such effects. The findings are discussed in relation to two arguments put forward to reconcile ecological and representational theories of visual object recognition.

Nerve injury and the laryngeal mask airway

The laryngeal mask airway is a widely used, non-invasive, general purpose airway. We report the case of a temporary vocal cord palsy following the use of such an airway. The development of inappropriately high cuff pressures secondary to nitrous oxide diffusion into the cuff is proposed as the most likely cause. Knowledge of the existence of nerve injuries complicating laryngeal mask use is particularly important when counselling certain patients. Mandatory intraoperative cuff pressure monitoring should lower the risk of subsequent voice problems.

Manual asymmetries in visually primed grasping

Previous research has shown that the task irrelevant size of familiar objects facilitates compatible precision and power grip responses. The present study examined whether the task irrelevant size of novel objects produces the same compatibility effect. However, the main objective of the study was to investigate whether visually primed precision and power grips are manually asymmetric. Experiment 1 showed that the size of a novel prime object does facilitate compatible precision and power grips, even when both the object itself and the grasp type are irrelevant to the current task. However, this effect was only found when the precision grip was made with the right hand (RH) and the power grip was made with the left hand (LH). When these grips were made with the opposite hands, the effect was absent. Experiment 2 replicated the LH bias for large objects and the RH bias for small objects when power and precision grip responses were replaced with simple LH and RH button-press responses. It appears that the two hemispheres are specialised with regard to precision and power compatible objects.

Action priming by briefly presented objects

Three experiments investigated how visual objects prime the actions they afford. The principal concern was whether such visuomotor priming depends upon a concurrent visual input--as would be expected if it is mediated by on-line dorsal system processes. Experiment 1 showed there to be essentially identical advantages for making afforded over non-afforded responses when these were made to objects still in view and following brief (30 or 50 ms) object exposures that were backward masked. Experiment 2 showed that affordance effects were also unaffected by stimulus degradation. Finally, Experiment 3 showed there to be statistically equal effects from images of objects and their names. The results suggest that an active object representation is sufficient to generate affordance compatibility effects based on associated actions, whether or not the object is concurrently visible.

Restoration-enamel interface with argon laser and visible light polymerization of compomer and composite resin restorations: a polarized light and scanning electron microscopic in vitro study

This polarized light (PL) and scanning electron microscopic (SEM) in vitro study investigated the effect of argon laser (AL) and visible light (VL) polymerization on the interfaces between compomer and composite resin restorations and the enamel cavosurfaces. Surface topography by SEM revealed a smooth transition between the restorative materials and adjacent enamel surfaces with no microspaces between the restorations and enamel surfaces. The enamel surfaces showed relatively smooth surface coatings with AL curing compared with exposure of etched prism endings with VL curing. The restoration-enamel interface by PL showed an intimate relationship between the restorative materials and the cavosurface enamel. No differences were found between AL and VL polymerization. With the restoration-enamel interface by SEM, compomers and composite resins were adapted closely to the cavosurface enamel and tags of restorative material protruded into the adjacent cavosurface enamel. Both VL and AL polymerization of compomers and composite resin restorations in vitro produced closely adapted restorations with intimate restoration-enamel interfaces. Such restoration-enamel interfaces may provide a certain degree of resistance against secondary caries formation, and this may be enhanced by the caries protective effect of argon laser irradiation.

Primary tooth enamel surface topography with in vitro argon laser irradiation alone and combined fluoride and argon laser treatment: scanning electon microscopic study

PURPOSE

The purpose of this descriptive scanning electron microscopic study was to characterize surface alterations in primary tooth enamel after in vitro argon laser irradiation alone and combined with topical fluoride treatment either before or after argon laser irradiation.

METHODS

Twenty extracted or exfoliated primary teeth underwent soft tissue debridement and a fluoride-free prophylaxis. Buccal and lingual surfaces were determined to be caries-free by macroscopic examination (stereo-zoom binocular microscope, x16). Treatment groups were: (1) no-treatment control; (2) argon laser irradiation (ALI; 11.5 J/cm2); (3) 1.23% acidulated phosphate fluoride (APF before ALI); and (4) ALI before APF. Both buccal and lingual surfaces were evaluated following standard scanning electron microscopic preparation techniques.

RESULTS

With controls, enamel surfaces were relatively smooth with occasional enamel prism ends present on their surfaces. There were no areas with cavitations or surface defects. With ALI, the lased surfaces were roughened mildly to moderately irregular without cavitation of the enamel or exposure of enamel prism ends. The surfaces possessed adherent granules to globules, with most being <3 microm in greatest dimension. Only occasional fine cracks and porosities in the surface coatings were noted and these were typically less than 1 microm in width or diameter. With APF before ALI, the surfaces possessed an irregular contour, with numerous granules to globules varying in size from 1 to 3 microm in greatest dimension. With ALI before APF, a homogenous confluent surface was present that masked typical enamel surface markings. The previously noted adherent granules and globules with argon laser treatment alone or APF before ALI were not seen. The argon laser effects on the enamel surfaces were masked by the uniformity of these surface coatings.

CONCLUSIONS

Argon laser irradiation and combined APF and argon laser treatment of primary tooth enamel created surfaces that may provide a protective barrier against a cariogenic attack. The surface coatings associated with combined APF and argon laser treatment may contain fluoride-rich calcium and phosphate mineral phases that could act as reservoirs for fluoride, calcium, and phosphate and provide a certain degree of protection from a caries lesion challenge.

Single value of serum transferrin receptor is not diagnostic for the absence of iron stores in anaemic patients with rheumatoid arthritis

Serum transferrin receptor (sTfR) concentrations were measured in anaemic patients with rheumatoid arthritis (RA). Serum transferrin receptor concentrations were positively correlated with the percentage of hypochromic cells and negatively correlated with MCH. There was a weak correlation with serum ferritin (sFn) concentration but not with reticulocyte count. Thus, high concentrations of sTfR indicate iron-deficient erythropoiesis rather than levels of storage iron in the tissues. Patients were divided into three groups on the basis of sFn concentration: those with probable tissue iron deficiency, those with adequate iron stores and those with intermediate values of sFn which did not allow classification. The median sTfR concentration was significantly higher in the iron-deficient group than in the other two groups but because of overlap between the three groups, a single sTfR value was of limited value in determining the level of storage iron in an individual with RA.

Objects automatically potentiate action: an fMRI study of implicit processing

Behavioural data have shown that the perception of an object automatically potentiates motor components (affordances) of possible actions toward that object, irrespective of the subject's intention. We carried out an event-related fMRI study to investigate the influence of the intrinsic properties of an object on motor responses which were either compatible or incompatible with the action that the object affords. The subjects performed power or precision grip responses based on the categorization of objects into natural or man-made. The objects were either 'small' (usually grasped with a precision grip) or 'large' (usually grasped with a power grip). As expected, the motor responses were fastest to objects that afforded the same grip (congruent) and slowest to objects that afforded the other grip (incongruent). Imaging revealed activations which covaried with compatibility in the parietal, dorsal premotor and inferior frontal cortex. We suggest that the greater the difference in reaction times between congruent and incongruent trials, the greater the competition between the action afforded by the object and the action specified by the task, and thus the greater the activation within this network.

Allergen-induced murine upper airway inflammation: local and systemic changes in murine experimental allergic rhinitis

The role of inflammatory effector cells in the pathogenesis of airway allergy has been the subject of much investigation. However, whether systemic factors are involved in the development of local responses in both upper and lower airways has not been fully clarified. The present study was performed to investigate aspects of the pathogenesis of isolated allergic rhinitis in a murine model sensitized to ovalbumin (OVA). Both upper- and lower-airway physiological responsiveness and inflammatory changes were assessed, as well as bone marrow progenitor responses, by culture and immunohistological methods. Significant nasal symptoms and hyper-responsiveness appeared after intranasal OVA challenge (P < 0.0001 and P < 0.01, respectively), accompanied with significant nasal mucosal changes in CD4+ cells (P < 0.001), interleukin (IL)-4+ cells (P < 0.01), IL-5+ cells (P < 0.01), basophilic cells (P < 0.02) and eosinophils (P < 0.001), in the complete absence of hyper-responsiveness or inflammatory changes in the lower airway. In the bone marrow, there were significant increases in CD34+ cells, as well as in eosinophils and basophilic cells. In the presence in vitro of mouse recombinant IL-5, IL-3 or granulocyte-macrophage colony-stimulating factor (GM-CSF), the level of bone marrow eosinophil/basophil (Eo/Baso) colony-forming cells increased significantly in the OVA-sensitized group. We conclude that, in this murine model of allergic rhinitis, haemopoietic progenitors are upregulated, which is consistent with the involvement of bone marrow in the pathogenesis of nasal mucosal inflammation. Both local and systemic events, initiated in response to allergen provocation, may be required for the pathogenesis of allergic rhinitis. Understanding these events and their regulation could provide new therapeutic targets for rhinitis and asthma.

Pharmacokinetics and tissue penetration of linezolid following multiple oral doses

The pharmacokinetics of multiple-dose linezolid were determined following administration of five 600-mg oral doses given every 12 h to each of six healthy male volunteers. Concentrations of the drug were determined in plasma and inflammatory blister fluid using high-pressure liquid chromatography. A mean peak concentration in plasma of 18.3 microg/ml (standard deviation [SD], 6.0) was attained at a mean time of 0.7 h (SD, 0.3) after the final dose. The penetration into the inflammatory fluid was 104% (SD, 20.7). A mean peak concentration of 16.4 microg/ml (SD, 10.6) was attained in the inflammatory fluid at 3 h (SD, 0.6) after the final dose. The elimination half-life from serum and inflammatory fluid was 4.9 (SD, 1.8) and 5.7 (SD, 1.7) h, respectively. The area under the concentration-time curve in plasma and blister fluid was 140.3 (SD, 73.1) and 155.3 (SD, 80.1) microg x h/ml, respectively. These data suggest that linezolid has good tissue penetration, and we can predict that it will be successful in the treatment of a variety of gram-positive infections.

A comparison of rural and urban ambulance crashes

Ambulance crashes are a significant safety issue both to the EMTs and to patients transported in the vehicle. Safety issues are dependent on the environment and may be different in rural and urban settings. Ambulance crashes reported to the State EMS bureau during the years of 1993 to 1997 were evaluated. Counties with >250,000 population were considered urban. State population was 2 million urban and 2.8 million rural. Two investigators determined first if the crash was urban or rural. Outcome information was extracted on the degree of injury, citations given, and information on the ambulance and other vehicle condition. In addition, independent variables of weekend versus weekday, day versus night, posted speed, weather, road condition (wet versus dry), intersections, and use of seat belts were extracted. Results were compared using a 2-tailed Chi-square or Fisher's exact with significance at P <.05. Relative risks and 95% confidence intervals were calculated for each variable. There were a total of 183 Ambulance crashes, 115 urban (19/million pop/yr), and 68 rural (8/million pop/yr). Significantly lower percentage of injury crashes occurred in the urban setting (OR = 0. 49, 95% CI = 0.24 to 0.98) with fewer of these considered "severe" (OR = 0.0, 95% CI = 0.0 to 0.73). Citations were more likely to be issued to the urban ambulance driver (OR = 4.95, 95% CI = 1.09 to 45. 70) and the other urban vehicle driver (OR = 3.65, 95% CI = 1.37 to 11.31). However, the urban ambulance was less likely to be damaged (OR = 0.24, 95% CI = 0.10 to 0.55), disabled (OR = 0.41, 95% CI = 0. 20 to 0.84), or towed (OR = 0.40, 95% CI = 0.20 to 0.83). In the urban setting fewer vehicles were traveling in areas with posted speeds >54 mph (OR = 0.24, 95% CI = 0.06 to 0.78) and nonrestrained people were less likely to be injured (OR = 0.28, 95% CI = 0.06 to 1. 25). For injured persons there was no difference in independent variables in the urban versus rural settings. Although the rate of ambulance injuries was greater in the urban environment, the severity of the injuries was worse in the rural environments where crashes occurred at higher posted speeds. In the rural setting nonrestrained passengers were more likely to be injured.

Micro-affordance: the potentiation of components of action by seen objects

It is suggested that seen objects potentiate a range of actions associated with them, irrespective of the intentions of the viewer. Evidence for this possibility is provided by the data from two experiments, both of which required a participant to make a binary motor response to an auditory stimulus. In the first experiment the response was a power or precision grip, which was performed whilst simultaneously viewing a real object which would normally be grasped using either a power or precision grip. A significant interaction of response and grip compatibility of the object was observed. Similar results were obtained in the second experiment when a wrist rotation of a given direction was used as a response, whilst viewing objects which would require wrist rotations if they were to be grasped. The effects of the seen objects on components of action are described as microaffordances which are said to be dispositional states of the viewer's nervous system.

A Spectroscopic Redshift for the Cl 0024+16 Multiple Arc System: Implications for the Central Mass Distribution

We present a spectroscopic redshift of z=1.675 for the well-known multiply lensed system of arcs seen in the z=0.39 cluster Cl 0024+16. In contrast to earlier work, we find that the lensed images are accurately reproduced by a projected mass distribution which traces the locations of the brightest cluster elliptical galaxies, suggesting that the most significant minima of the cluster potential are not dynamically erased. The averaged mass profile is shallow and consistent with predictions of recent numerical simulations. The source redshift enables us to determine an enclosed cluster mass of M(<100 kpc h-1&parr0;=1.11+/-0.03x1014 h-1 M middle dot in circle (Omega=1) and a mass-to-light ratio of M&solm0;LB(<100 kpc h-1&parr0;=320+/-30 h &parl0;M&solm0;LB&parr0; middle dot in circle (virtually independent of curvature), after correction for passive stellar evolution. The arc spectrum contains many ionized absorption lines and closely resembles that of the local Wolf-Rayet galaxy NGC 4217. Our lens model predicts a high magnification ( approximately 20) for each image and identifies a new pair of multiple images of a galaxy at a predicted redshift of z=1.3.

Anxiolytic effects of the neuroactive steroid pregnanolone (3 alpha-OH-5 beta-pregnan-20-one) after microinjection in the dorsal hippocampus and lateral septum

The anxiolytic effects of the neuroactive steroid, 3 alpha-OH-5 beta-pregnan-20-one (pregnanolone), were determined after injection into the dorsal hippocampus or lateral septum in adult male rats. An increase in the proportion of time spent on the open arms of the elevated plus-maze was found after 2.5 and 5 micrograms of pregnanolone in the hippocampus, but not in the lateral septum. Intrahippocampal injection of 2.5 micrograms of the 3 beta-epimer of pregnanolone did not affect behavior in the plus-maze; a higher dose of 5 micrograms produced an anxiogenic effect. In the shock-probe burying test latency to burying behavior was increased by intrahippocampal or intraseptal injection of 2.5 and 5 micrograms of pregnanolone; the duration of burying behavior was decreased by 0.5, 2.5 and 5 micrograms of pregnanolone injection in the dorsal hippocampus or lateral septum. The number of contacts with the shock probe was not affected by any dose of pregnanolone in either intracranial site of injection. The anxiolytic effects of intrahippocampal or intraseptal injection of pregnanolone were blocked by intracranial pretreatment with 20 ng of picrotoxin, but not by microinjection of 5 micrograms of flumazenil or 200 ng of PK 11195. Thus, inhibition of the hippocampus, mediated by the pregnanolone's action at the GABAA receptor, produces a general anxiolytic effect. However, similar inhibition in the lateral septum attenuates active avoidance of anxiogenic stimuli (i.e., decreased burying behavior), but not passive avoidance of aversive stimuli (i.e., exploration of open arms of the plus-maze and number of shocks in the probe burying test).

Analysis of genetic polymorphisms at the interleukin-10 and tumour necrosis factor loci in early-onset periodontitis

Early onset periodontitis (EOP) is considered to have a substantial genetic basis, although the gene or genes involved have not been elucidated. The aim of the present study was to investigate possible links between generalized EOP (GEOP) and genes regulating expression of the cytokines tumour necrosis factor (TNF) and interleukin-10 (IL-10). Microsatellite marker DNA sequences corresponding to phenotypic variations in cytokine response were analysed. Genotypic variations in cytokine response have been shown in vitro for TNF and IL-10, and specific alleles are implicated in diseases such as systemic lupus erythmatosus (SLE) and rheumatoid arthritis (RA). Two microsatellites at the IL-10 locus, IL10.R and IL10.G, and 1 microsatellite at the TNF locus, TNFa, were typed for 77 GEOP patients in the West of Scotland. Due to the highly polymorphic nature of the microsatellite loci, a statistical comparison with ethnically matched healthy controls (TNFa, n = 91, IL10.R, n = 94, IL10.G, n = 102) was conducted using a Monte Carlo simulation for each marker. No significant differences were observed for any of the 3 markers, although there were possible indications of trends similar to those observed in SLE for the IL10.G marker. In conclusion, no links were found between GEOP and microsatellites at TNFa, IL10.R or IL10.G loci.

Allergen-induced increase in airway responsiveness, airway eosinophilia, and bone-marrow eosinophil progenitors in mice

Increases in bone-marrow (BM) inflammatory cell progenitors are associated with allergen-induced airway hyperresponsiveness and inflammation in asthmatics and dogs. Here, for the first time, we compare the time course of airway hyperresponsiveness, inflammation, and marrow progenitor responses in a mouse model of airway allergen challenge. Sensitized BALB/c mice were studied at 2, 12, 24, 48, and 72 h after intranasal ovalbumin or saline challenges. Outcome measurements included airway responsiveness, airway inflammation as assessed via bronchoalveolar lavage (BAL) and lung tissue sections, and BM eosinophil colony-forming units (Eo-CFU) as enumerated using a semisolid culture assay with optimal concentrations of interleukin-5. We observed significant increases in BAL fluid eosinophils, neutrophils, lymphocytes, and macrophages by 2 h after the second of two intranasal allergen challenges (P < 0.05). Significant increases in airway responsiveness or BM Eo-CFU were observed at 24 h and persisted until 48 h after the second challenge (P < 0.05). Airway inflammation, including eosinophils, persisted until at least 72 h (P < 0.05). We observed that allergen-induced airway eosinophilia is accompanied by increases in BM eosinophil progenitors, indicating that in this model, increased eosinophil production involves an expansion of the relevant stem-cell population. These findings support the use of this model to explore the mechanisms of increased eosinopoiesis observed in human asthma.

Determination of fluoroquinolone residues in animal tissues by liquid chromatography

A simple liquid chromatographic (LC) method was developed for the determination of fluoroquinolones (ciprofloxacin, difloxacin, enrofloxacin and sarafloxacin) in animal tissues. Isolation of fluoroquinolones from biological matrices was performed with 5% trichloroacetic acid-acetonitrile (7:3) solution. For clean-up, solid-phase extraction with an SDBI (styrene-divinylobenzene) cartridge was used. LC analyses were performed with analytical column (LiChrospher 100 RP-8 5 microns) and mobile phase (0.025 M o-phosphoric acid-acetonitrile 70:30, v/v) in ion-pair mode. The whole procedure was validated in intra- and inter-assay reproducibility and accuracy determination by simultaneously assaying of muscle, liver and kidney samples supplemented with fluoroquinolones at the level of 30 and 60 ng/g, respectively. The statistical evaluation demonstrates high absolute recovery (> 80%) and low coefficient of variation (< 10%) for all analysed samples. The detection limits for fluoroquinolones were 5 ng/g in muscle, liver and kidney samples.

A randomized, double-blind, placebo-controlled trial of prophylactic recombinant human granulocyte-macrophage colony-stimulating factor to reduce nosocomial infections in very low birth weight neonates

OBJECTIVE

We carried out a randomized placebo-controlled trial in very low birth weight neonates (VLBWNs), comparing the incidence of nosocomial infections after the prophylactic use of recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) versus placebo in VLBWNs.

STUDY DESIGN

VLBWNs (n = 264), weighing 501 to 1000 g, </=72 hours of age were randomly assigned to receive rhu GM-CSF (8 microg/kg/d), administered intravenously (n = 134) over 2 hours daily x 7 days and every other day for 21 days, or placebo (n = 130). The safety, incidence of nosocomial infections, days of absolute neutrophil count >/=4000/mm,3 peripheral blood progenitor studies, and 24-hour polymorphonuclear leukocyte C3bi receptor expression were compared between the 2 treatment groups.

RESULTS

No (grade III/IV) toxicity or adverse events were associated with rhu GM-CSF. The absolute neutrophil count and absolute eosinophil count were significantly elevated in the rhu GM-CSF group on days 7 (P =.001), 14 (P =.001), and 21 (P =.007) and on days 7 and 28 (P =.012 and P =.001, respectively). However, there was no difference in the incidence of confirmed nosocomial infections between the 2 treatment groups in this trial (40% vs 39%, rhu GM-CSF vs placebo; P = NS).

CONCLUSION

In a large randomized placebo-controlled trial, prophylactic administration of rhu GM-CSF in VLBWNs does not appear to decrease the incidence of nosocomial infections.

Determination of tetracycline residues in animal tissues by liquid chromatography

A simple liquid chromatographic (LC) method was developed for the determination of tetracyclines (oxy-tetracycline, tetracycline and chlortetracycline) in animal tissues. Isolation of tetracyclines from biological matrices was performed with oxalic buffer followed by dechelation and deproteinization with oxalic acid-acetonitrile solution. For clean-up solid phase extraction with a SDBI (styrene-divinylbenzene) cartridge was used. LC analysis was performed on a polymeric analytical column (PLRP-S 5 microns, 150 x 4.6 mm) and using an oxalic acid mobile phase (0.01 M oxalic acid - acetonitrile 75:25, v/v). The whole procedure was validated for intra- and inter-assay reproducibility determination by assaying muscle, liver and kidney samples supplemented with tetracyclines at the level of 50, 100 and 200 ng/g, respectively. The statistical evaluation demonstrates high absolute recovery (> 80%) and low coefficient of variation (< 10%) for all analysed samples. The detection limits for tetracyclines were 10-15 ng/g in muscle, and 20-25 ng/g in liver and kidney samples, depending on the analyte.

Rationale and potential use of cytokines in the prevention and treatment of neonatal sepsis

Despite advances in the use of newer antimicrobials and aggressive supportive care, sepsis and its sequalae remain a major source of morbidity and mortality in the neonate. The VLBW neonate is especially at high risk. We and others have demonstrated that neonatal MNC are deficient in their production of G-CSF and GM-CSF, which, in part, may explain the neonates propensity to develop neutropenia during times of sepsis. G-CSF and GM-CSF have been shown to both enhance neonatal neutrophil superoxide production in vitro and to increase circulating neutrophil numbers through expansion of the NSP in the BM in neonatal rats and humans. G-CSF is protective (if given with or before antibiotics) during experimental GBS in the neonatal rat and appears to be well tolerated (both short term and 2 years after its use) in the human neonate. In a phase II randomized pilot multicenter study, GM-CSF prophylaxis in the VLBW neonate was well tolerated during 4 weeks of administration and was noted to have significantly reduced the incidence of nosocomial infections. Future efficacy and safety studies in more neonates need to be completed and assessed before the routine pharmacologic use of G-CSF or GM-CSF is recommended to prevent and treat neonatal sepsis.

On the relations between seen objects and components of potential actions

Accounts of visually directed actions usually assume that their planning begins with an intention to act. This article describes three experiments that challenged this view through the use of a stimulus-response compatibility paradigm with photographs of common graspable objects as stimuli. Participants had to decide as fast as possible whether each object was upright or inverted. Experiments 1 and 2 examined the effect of the irrelevant dimension of left-right object orientation on bimanual and unimanual keypress responses. Experiment 3 examined wrist rotation responses to objects requiring either clockwise or anticlockwise wrist rotations when grasped. The results (a) are consistent with the view that seen objects automatically potentiate components of the actions they afford, (b) show that compatibility effects of an irrelevant stimulus dimension can be obtained across a wide variety of naturally occurring stimuli, and (c) support the view that intentions to act operate on already existing motor representations of the possible actions in a visual scene.

On the relations between seen objects and components of potential actions

Accounts of visually directed actions usually assume that their planning begins with an intention to act. This article describes three experiments that challenged this view through the use of a stimulus-response compatibility paradigm with photographs of common graspable objects as stimuli. Participants had to decide as fast as possible whether each object was upright or inverted. Experiments 1 and 2 examined the effect of the irrelevant dimension of left-right object orientation on bimanual and unimanual keypress responses. Experiment 3 examined wrist rotation responses to objects requiring either clockwise or anticlockwise wrist rotations when grasped. The results (a) are consistent with the view that seen objects automatically potentiate components of the actions they afford, (b) show that compatibility effects of an irrelevant stimulus dimension can be obtained across a wide variety of naturally occurring stimuli, and (c) support the view that intentions to act operate on already existing motor representations of the possible actions in a visual scene.

The use of fluoroscopy to guide needle placement in interstitial gynecological brachytherapy

PURPOSE

Interstitial brachytherapy is generally performed for gynecological malignancies with extensive parametrial involvement, by inserting the needles through a transperineal template. Often, the implanted needles are not parallel, and the multiple sources can be difficult to identify on localization radiographs, especially if obtained with a portable X-ray unit. We have used fluoroscopy to guide the needles for interstitial brachytherapy to treat various gynecological malignancies. Because the resultant needles are parallel, dosimetry can be performed based on the template hole positions used, rather than identifying individual sources. This report focuses on the technique; the outcome of patients implanted with this technique will be reported separately.

METHODS

Seventy-one patients were implanted transperineally with 192iridium using a Syed template under fluoroscopic guidance, from September 1989 to May 1995, for bulky parametrial disease, narrow vagina, extensive vaginal involvement, recurrent disease after previous course of pelvic radiation therapy, or in cases in which the patient had previously undergone hysterectomy. 137Cesium was added in a central tandem in cases with a cervical os. Thirty patients were treated for primary cervical or vaginal carcinoma; 41 patients were treated for recurrent disease from endometrial or cervical cancers. The brachytherapy dose (prescribed to the periphery of the implant) was 40 to 55 Gy when used alone (15 patients) and 22-40 Gy when used as a boost to 34.2 to 59.4 Gy of pelvic external-beam radiotherapy (56 patients). The patients were followed for 6 to 63 months.

RESULTS

In all cases, some of the needles had to be repositioned to improve the alignment. Hence, the use of fluoroscopy aided in achieving parallel placement of the needles in all implants as seen on anterior-posterior radiographs. Because the 192iridium sources were ordered beforehand based on the preplan, and the dosimetry was based on idealized geometry of the template hole positions, all patients were loaded on the same day of implant.

CONCLUSION

Fluoroscopically guided perineal interstitial brachytherapy is a feasible technique for use in various gynecological malignancies. The use of fluoroscopic guidance helped to achieve parallel needle placement in all of our implants, but it required repositioning of some of the needles in all cases. The parallel positioning allowed the use of preplanned dosimetry, minimizing the delay in loading of the patients. The outcome of the patients treated using this technique is currently undergoing analysis and will be reported separately.

The effect of treatment with budesonide or PGE2 in vitro on allergen-induced increases in canine bone marrow progenitors

Increased bone marrow granulocyte-macrophage colony forming units (GM-CFU) in dogs developing allergen-induced airway hyperresponsiveness can be accounted for by a factor(s) present in serum following the allergen challenge. The present study evaluated whether in vitro treatment of bone marrow with budesonide or prostaglandin (PG)E2, prevents allergen-induced bone marrow stimulation. Eight dogs were studied after allergen and diluent inhalation challenges. Budesonide (10[-7] M) or PGE2 (10[-6] M) was added to bone marrow aspirated 24 h after challenge. Budesonide or PGE2 was also added to bone marrow aspirated before challenge, to which serum taken 24 h after challenge was subsequently added. Non-adherent mononuclear bone marrow cells were incubated in the presence of the serum and granulocyte/macrophage colony stimulating factor (GM-CSF), granulocyte stimulating factor (G-CSF), or stem cell factor (SCF), and the number of GM-CFU counted. Allergen-induced increases in the number of GM-CFU in bone marrow aspirated 24 h after allergen (P < 0.001) were not attenuated by budesonide or PGE2 treatment (P > 0.05). However, GM-CFU increases in bone marrow aspirated before challenge and incubated with post-allergen challenge serum (P < 0.001) were blocked by either budesonide or PGE2 (P < 0.001). These findings demonstrate that budesonide and PGE2 can act directly on the bone marrow, preventing allergen-induced increases in inflammatory cell progenitor production. This suggests that the bone marrow must be considered as a possible site of action for drugs which attenuate allergen-induced asthmatic responses.

Early-onset Alzheimer's disease with a presenilin-1 mutation at the site corresponding to the Volga German presenilin-2 mutation

We describe a new mutation causing Alzheimer's disease (AD) in presenilin-1 (N135D) that is at the homologous site to the presenilin 2 mutation (N141I) in Volga German kindreds. The phenotype of PS1 N135D is an early-onset (34-38 years) disease. The mutation forms part of, and extends, the alpha-helical array of mutations in transmembrane 2 of the presenilins and leads to the suggestion that disruption of this helical face is the molecular insult that leads to disease.