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Molecular characterization of Thelazia lacrymalis (Nematoda, Spirurida) affecting equids: a tool for vector identification.

Equine thelaziosis caused by the eyeworm Thelazia lacrymalis is a parasitic disease transmitted by muscid flies. Although equine thelaziosis is known to have worldwide distribution, information on the epidemiology and presence of the intermediate hosts of T. lacrymalis is lacking. In the present work, a PCR-RFLP based assay on the first and/or second internal transcribed spacer (ITS1 and ITS2) of ribosomal DNA was developed for the detection of T. lacrymalis DNA in its putative vector(s). The sensitivity of the technique was also assessed. The restriction patterns obtained readily differentiated T. lacrymalis from four species of Musca (Diptera, Muscidae) (i.e. Musca autumnalis, Musca domestica, Musca larvipara and Musca osiris), which are potential vectors of equine eyeworms. The molecular assay presented herein is a useful tool to identify the intermediate host(s) of T. lacrymalis in natural conditions and to study its/their ecology and epidemiology.

Animals↗

Restricted ocular exploration does not seem to explain simultanagnosia.

One major function of parietal cortex is to direct our attention towards salient stimuli. The present data suggest that it also plays an important role in visual gestalt perception. Patients with simultanagnosia following lesions in this area are not able to extract the meaning of a visual scene whereas being perfectly able to recognise individual objects of this scene. We tested two patients with simultanagnosia with hierarchical Navon figures combined with eye movements recordings. The patients' performance allowed us to compare directly the scan paths in trials in which the global letter shape was recognised with trials in which the global letter shape was not recognised. We did not find any obvious differences in the eye movement pattern related to the two perceptual situations. The two patients did not show a significant problem in shifting their eyes (and thus possibly also their attentional focus) to all aspects of the complex visual stimulus when attempting to bind together the different elements of spatially distributed information. The results demonstrate that restricted ocular exploration cannot be the reason for the patients' inability to recognise the global shape of stimuli. Our data rather suggest a role of parietal cortex in visual gestalt perception that is beyond its role of directing attention towards relevant objects.

Agnosia↗

Intake fractions of industrial air pollutants in China: estimation and application.

Intake fractions, an emissions-intake relationship for primary pollutants, are defined and are estimated in order to make simple estimates of health damages from air pollution. The sulfur dioxide (SO2) and total suspended particles (TSP) intake fractions for five cities of China are estimated for the four main polluting industries-electric power generation, mineral (mostly cement) products industry, chemical process industry and metallurgical industry (mainly iron and steel smelting). The Industrial Source Complex Long Term (ISTLT3) model is used to simulate the spatial distribution of incremental ambient concentrations due to emissions from a large sample of site-specific sources. Detailed population distribution information is used for each city. The average intake fractions within 50 km of these sources are 4.4x10(-6) for TSP, and 4.2x10(-6) for SO2, with standard deviations of 8.15x10(-6) and 9.16x10(-6), respectively. They vary over a wide range, from 10(-7) to 10(-5). Although the electric power generation has been the focus of much of the air pollution research in China, our results show that it has the lowest average intake fraction for a local range among the four industries, which highlights the importance of pollutant emissions from other industrial sources. Sensitivity analyses show how the intake fractions are affected by the source and pollutant characteristics, the most important parameter being the size of the domain. However, the intake fraction estimates are robust enough to be useful for evaluating the local impacts on human health of primary SO2 and TSP emissions. An application of intake fractions is given to demonstrate how this approach provides a rapid population risk estimate if the dose-response function is linear without threshold, and hence can help in prioritizing pollution control efforts.

Air Pollutants↗

Ultrasound-assisted hydrogenation of cinnamaldehyde.

The hydrogenation, employing hydrogen gas, of cinnamaldehyde was performed using Pd-black and Raney Ni catalysts at 298+/-3 K in a water-cooled (jacketed) reaction vessel. Sampling at pre-determined time intervals and GC/MS analysis yielded time-dependent product state distribution information. A kinetic modeling of the data revealed that cinnamaldehyde was both hydrogenated directly to the final product benzenepropanol, as well as a fraction being converted to the intermediate benzenepropanal, where the latter was subsequently hydrogenated to benzenepropanol. Comparing the ultrasound-assisted and blank (stirred) experiments revealed that a higher maximum relative concentration of the intermediate benzenepropanal was formed in the ultrasound experiments compared to the stirred experiment. The activity of the ultrasound experiments compared to blank were 9-fold and 20-fold greater for the Pd-black and Raney Ni catalysts, respectively. Finally, an application of the Bell-Evans-Polanyi principle to yield an estimate of the ratio of rate coefficients for benzenepropanal and benzenepropanol formation was performed by considering chemical group energy differences and surface adsorption energy differences in the first mechanistic step of hydrogenation.

Journal Article↗

Causes and consequences of oral contraceptive noncompliance.

Compliance difficulties are more common among oral contraceptive users than is generally appreciated. Inconsistent use and method discontinuation are estimated to account for approximately 20% of the annual 3.5 million annual unintended pregnancies in the United States. In the past research focused on adolescents, for whom predictors of poor oral contraceptive compliance include multiple sex partners, low evaluation of personal health, low degree of concern about pregnancy, and previous abortion. More recent research confirms that compliance problems are common among all age groups, with 47% of women missing >/=1 pill per cycle and almost a quarter (22%) missing >/=2 pills per cycle. Good compliance has been linked to patient satisfaction with the clinician, the absence of certain side effects, establishing a regular daily routine to take oral contraceptives, and reading information distributed with oral contraceptive packaging. Clinicians are the focal point for improving oral contraceptive compliance. They should focus counseling on the transience of most side effects, instructions on dealing with a missed pill, provision of a backup method, and establishment of a daily pill-taking routine. Easy-to-understand literature should be given to patients to take home.

Adolescent↗

Simultaneous determination of intramolecular distance distributions and conformational dynamics by global analysis of energy transfer measurements.

Fluorescence energy transfer is widely used for determination of intramolecular distances in macromolecules. The time dependence of the rate of energy transfer is a function of the donor/acceptor distance distribution and fluctuations between the various conformations which may occur during the lifetime of the excited state. Previous attempts to recover both distance distributions and segmental diffusion from time-resolved experiments have been unsuccessful due to the extreme correlation between fitting parameters. A method has been developed, based on global analysis of both donor and acceptor fluorescence decay curves, which overcomes this extreme cross-correlation and allows the parameters of the equilibrium distance distributions and intramolecular diffusion constants to be recovered with high statistical significance and accuracy. Simulation studies of typical intramolecular energy transfer experiments reveal that both static and dynamic conformational distribution information can thus be obtained at a single temperature and viscosity.

Biopolymers↗

Why implementing the space option is necessary for society.

For several years, specialized agencies have been searching for "new programs" that could reinvigorate the support for space activities and stop their budgets' decline of. But the same time, they have been retrenching by focusing on collecting and distributing information, putting scientific research as their core projects. On a planet soon to host a 10-billion population that will impact the biosphere's workings as never before, at a time when many governments and organizations see the virtue in the management of scarcity, musing on the origins of life and of the solar system can hardly be expected to be invested with high priority. The space option arose from the analysis of the issues confronting humanity. In reviewing the material needs of the human population in the near future, the analysis finds that the impact on the biosphere will perforce be much larger than it usually seems to be acceptable to assume.

Conservation of Natural Resources↗

North and South: bridging the information gap.

Information exchange is critical for development of health systems. The information needs of less-developed countries are especially challenging, but many factors inhibit free flow of knowledge. There is much talk about how technical fixes--such as the internet--might fill this information gap. Yet few attempts have been made to ask clinical investigators who work in resource-poor regions for their views on these difficulties and the possible solutions. The messages reported here, from a survey of Lancet editorial advisors, suggest that information, research, and publication capacities are intimately linked. Investigators, publishers, editors, and editorial organisations all have important parts to play in solving this global information poverty.

Africa↗

Telecommunication discussion groups for health services and medical research.

International university and research institute telecommunication links provide free or low-cost access to several computer networks (commercial and non-commercial). Previously used by science researchers, such networks are now used in clinical and social medicine. University affiliation, a personal computer, and a modern and software are needed. A host-computer, at a local computing centre, operates server software that automatically distributes information to subscribers. The server stores all messages in a monthly logbook that can be edited to produce an electronic magazine. The magazine can also be accessed by non-subscribers. The software gives convenient, fast, single-key processing of messages and files and also allows on-line conferences. Discussion groups on several medical specialties and data bases for AIDS and other communicable diseases are already operating.

Computer Communication Networks↗

10-year educational programme aimed at rheumatic fever in two French Caribbean islands.

BACKGROUND: In less developed countries, rheumatic fever still occurs. We started a long-term educational programme in two French Caribbean islands that was directed at the public and at health-care workers to see whether we could reduce the incidence of rheumatic fever. METHODS: Our 10-year programme started in 1981 in Martinique and Guadeloupe, and was based in the community and in clinics and hospitals. The programme established a registry of all cases of primary and secondary rheumatic fever (diagnosed by Jones' modified criteria), with systematic hospital admission of children. We graded carditis as severe, mild, or subclinical, and acute glomerulonephritis was defined by oedema, proteinuria, and haematuria for less than 3 months. The educational part of the programme targeted the public and health-care workers, including doctors, with written information distributed in schools or via radio and television broadcasts or videotapes. For the public, the benign clinical presentation of the initial streptococcal infection was contrasted with the severity of later heart disease. FINDINGS: The first months of the programme led to a 10-20% increase in the number of rheumatic fever cases admitted to hospital, because of the renewed attention paid to the disease. Therefore we took 1982 as the baseline year. In 1982-83 the incidence of rheumatic fever was 19.6 per 100 000 inhabitants aged under 20 in Martinique, and 17.4 per 100 000 in Guadeloupe. In 100 Martinique children and 97 Guadeloupe children in 1982-83, 40 and 71% had carditis, respectively (severe in 10 and 32%). Rheumatic fever was preceded by symptomatic sore throat in 52 and 41% of cases, respectively. The disease was not seen in children with active streptococcal cutaneous infections. Disease frequency was highest in the poorest areas and families, a finding that persisted over time. The programme was associated with a progressive decline in the frequency of rheumatic fever: final reduction of 78% in Martinique and 74% in Guadeloupe. The frequency of carditis also fell. Apart from two outbreaks in one hospital, the frequency of acute glomerulonephritis also declined; 31% of cases had had sore throat, while 56% had skin infections. The cost of the programme during the 4 most intensive years was FFr 250 000 (US$ 44 500) in each island. The cost of childhood rheumatic fever, excluding late sequelae, was initially (in 1982) about FFr 7.8 million (US$ 1426 000). The cost fell to an average of Ffr 550 000 (US$ 100 000) per year in 1991-92. INTERPRETATION: A rapid decline in rheumatic fever incidence was achieved at modest cost. Such a programme needs to be continued because of the risk of disease resurgence.

Adolescent↗

Treating poisonings: focus on syrup of ipecac.

The awareness of poison prevention is increasing despite an alarming incidence of accidental and intentional poisonings in the United States. During 1990, 72 poison centers throughout the United States, serving a population of 191.7 million, submitted to the American Association of Poison Control Centers data collection system 1,713,462 cases of poisonings, which included 612 deaths. Emetic agents, when used properly, can reduce the extent and severity of improperly ingested medications, selected household products, and other toxic chemicals. The pharmacist can play a valuable role in distributing information about poison control centers, poison prevention, and appropriate treatment of poisonings.

Accidents, Home↗

Quantification and predictors of prostate position variability in 50 patients evaluated with multiple CT scans during conformal radiotherapy.

PURPOSE: To determine the extent and predictors for prostatic motion in a large number of patients evaluated with multiple CT scans during radiotherapy, and evaluate the implications of these data on the design of appropriate treatment margins for patients receiving high-dose three-dimensional conformal radiotherapy. MATERIALS AND METHODS: Fifty patients underwent four serial computerized tomography (CT) scans, consisting of an initial planning scan and subsequent scans at the beginning, middle, and end of the treatment course. Each scan was performed with the patient in the prone treatment position within an immobilization device used during therapy. Contours of the prostate and seminal vesicles were drawn on the axial CT slices of each scan, and the scans were matched by alignment of the pelvic bones with a chamfer matching algorithm. Using the contour information, distributions of the displacement of the organ center of mass and organ border from the planning position were determined separately for the prostate and seminal vesicles in each of the three principle directions: anterior-posterior (AP), superior-inferior (SI) and left-right (LR). Each distribution was fitted to a normal (Gaussian) distribution to determine confidence limits in the center of mass and border displacements and thereby evaluate for the optimal margins needed to contain target motion. RESULTS: The most common directions of displacement of the prostate center of mass (COM) were in the AP and SI directions and were significantly larger than any LR movement. The mean prostate COM displacement (+/- 1 standard deviation, SD) for the entire population was -1.2 +/- 2.9 mm, -0.5 +/- 3.3 mm and -0.6 +/- 0.8 mm in the, AP and SI and LR directions respectively (negative values indicate posterior, inferior or left displacement). The mean (+/- 1 SD) seminal vesicle COM displacement for the entire population was - 1.4 +/- 4.9 mm, 1.3 +/- 5.5 mm and -0.8 +/- 3.1 mm in the AP and SI and LR directions, respectively. The data indicate a tendency for the population towards posterior displacements of the prostate from the planning position and both posterior and superior displacements of the seminal vesicles. AP movement of both the prostate and seminal vesicles were correlated with changes in rectal volume (P = 0.0014 and < 0.0001, respectively) more than with changes in bladder volume (P = 0.030 for seminal vesicles and 0.19 for prostate). A logistic regression analysis identified the combination of rectal volume > 60 cm3 and bladder volumes > 40 cm3 as the only predictor of large ( > 3 mm) systematic deviations for the prostate and seminal vesicles (P = 0.05) defined for each patient as the difference between organ position in the planning scan and mean position as calculated from the three subsequent scans. CONCLUSIONS: Prostatic displacement during a course of radiotherapy is more pronounced among patients with initial planning scans with large rectal and bladder volumes. Such patients may require more generous margins around the CTV to assure its enclosure within the prescription dose region. Identification and correction of patients with large systematic errors will minimize the extent of the margin required and decrease the volume of normal tissue exposed to higher radiation doses.

Artifacts↗

Potassium signalling in the brain: its role in behaviour.

This paper examines evidence that glial cells respond to changes in extracellular potassium ([K+]e) in ways that contribute to modulation of neuronal activity and thereby behaviour. Glial cells spatially (and probably directionally) redistribute potassium from regions of increasing concentration to those with a lesser concentration. This redistribution is largely responsible for slow potential shifts associated with behavioural responses of animals. These slow shifts are related in amplitude to the level of 'arousal' of an animal, and its motivational state. In addition, glia, especially astrocytes, respond to changes in [K+]e, the presence of transmitters like nor-adrenaline and glutamate and at least some hormones with changes in their metabolism and/or the morphological characteristics of the cell. The ionic, metabolic and morphological responses of glia to changes in extracellular potassium after neuronal activity have been associated with at least some forms of learning, including habituation, one trial passive avoidance learning and changes associated with enriched environments. The implication of these effects of potassium signalling in the brain is that there is considerable involvement of glia in a number of processes crucial to neuronal activity. Glia may also form another route for information distribution in the brain that is at least bi-directional, though less specific than its neuronal counterparts. It is evident that the Neuroscience of the future will have to incorporate much more study of neuron-glial interactions than hitherto.

Animals↗

Nomenclature in the Journal of Hand Surgery.

Unambiguous description of anatomical structures is essential to communicate information either in the clinical or research context. In view of this and following recommendations by the Nomenclature Committee of the International Societies for Surgery of the Hand (IFSSH), the booklet "Terminology for Hand Surgery" was published in 2001. The aim of this study was to identify whether the nomenclature used in the papers published in the Journal of Hand Surgery (British and European volume) followed its recommendations. The study showed that we still continue to use traditional terminology. The most common "mistake" is numbering of the metacarpals instead of naming them. Usage of newer terms would improve the clarity of information distributed.

Guidelines as Topic↗

Object manifestations for medical imaging applications.

As healthcare providers become increasingly decentralized and distributed, information systems support must follow suit by providing healthcare professionals with flexible, adaptable and secure views of medical data in a timely fashion. To this end, this paper introduces the notion of manifestations of medical image objects in a heterogeneous client environment. We define the fundamental building blocks of manifestations using object-oriented concepts. Examples are given of how constraints and rules can be used to govern the presentation of data within objects and for the environmental (e.g. hardware and network) and user defined factors (e.g. preferences) that act as inputs to manifestations. Using these techniques, we give several examples of user interactions with a system based on manifestations. This paper demonstrates how objects can be efficiently and effectively presented to users with various information appliances using manifestation techniques.

Computer Security↗

Tracking the mind's image in the brain II: transcranial magnetic stimulation reveals parietal asymmetry in visuospatial imagery.

The functional relevance of brain activity during visuospatial tasks was investigated by combining functional magnetic resonance imaging with unilateral repetitive transcranial magnetic stimulation (rTMS). The cognitive tasks involved visuospatial operations on visually presented and mentally imagined material ("mental clock task"). While visuospatial operations were associated with activation of the intraparietal sulcus region bilaterally, only the group which received rTMS to the right parietal lobe showed an impairment of performance during and immediately after rTMS. This functional parietal asymmetry might indicate a capacity of the right parietal lobe to compensate for a temporary suppression of the left. This is compatible with current theories of spatial hemineglect and constitutes a constraint for models of distributed information processing in the parietal lobes.

Acoustic Stimulation↗

Scaling up post-abortion care in Guatemala: initial successes at national level.

This article describes a programme to scale up post-abortion care services in 22 of the 33 public sector district hospitals in Guatemala from July 2003 to December 2004. The main interventions included strengthening the knowledge and technical capacity of staff, expanding post-abortion care, enhancing related infrastructure, distributing informational materials and instituting an abortion surveillance system. A facilitator supported the work through week-long, monthly visits at each hospital. Attention was also devoted to building institutional consensus in support of post-abortion care at government, district hospital and hospital staff levels. During this period, 13,928 women with incomplete abortions were admitted to the 22 hospitals. Use of manual vacuum aspiration for treatment of incomplete first trimester abortion increased from 38% to 68% of cases (p<0.0001). Provision of family planning counselling also increased, from 31% to 78% of women (p<0.0001), and the proportion of women selecting a contraceptive method before leaving hospital from 20% to 49% (p<0.0001). Infection was associated with 71% of the incomplete abortions, of which 90% were septic. There were nine deaths and 768 women suffered severe complications, the level of which remained unchanged during the study period. Guatemala still has much to do to institutionalise post-abortion care fully and reduce deaths and complications, but our efforts to date will be valuable to others.

Abortion, Incomplete↗

Analysis of the accuracy of determining average molecular weights of narrow polydispersity polymers by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) can be used to determine number- and weight-average molecular weights of narrow polydispersity polymers. In this work, several possible sources of error in determining molecular weights of polymers with narrow polydispersity by MALDI-TOFMS are rigorously examined. These include the change in polymer distribution function, broadening or narrowing of the overall distribution, and the truncation of selected oligomer peaks within a distribution (i.e., the oligomer peaks at the high- and low-mass tails expected to be observed are not detected). These variations could be brought about by a limited detection sensitivity, background interference, and/or mass discrimination of oligomer analysis in MALDI-TOFMS. For narrow polydispersity polystyrenes, it is shown that by using an appropriate MALDI matrix and sample preparation protocol and a sensitive ion detection instrument, no systematic errors from these possible variations were detected within the experimental precision (0.5% relative standard deviation) of the MALDI method. It is concluded that MALDI mass spectrometry can provide accurate molecular weight and molecular weight distribution information for narrow polydispersity polymers, at least for polystyrenes examined in this work. The implications of this finding for polymer analysis are discussed.

Indicators and Reagents↗