Liquid Structure of Ionic Liquids with [NTf2]- Anions, Derived from Neutron Scattering

The liquid structure of three common ionic liquids (ILs) was investigated by neutron scattering for the first time. The ILs were based on the bis(trifluoromethanesulfonyl)imide anion, abbreviated in the literature as [NTf2]- or [TFSI]-, and on the following cations: 1-ethyl-3-methylimidazolium, [C2mim]+; 1-decyl-3-methylimidazolium, [C10mim]+; and trihexyl(tetradecyl)phosphonium, [P666,14]+. Comparative analysis of the three ILs confirmed increased size of nonpolar nanodomains with increasing bulk of alkyl chains. It also sheds light on the cation-anion interactions, providing experimental insight into strength, directionality, and angle of hydrogen bonds between protons on the imidazolium ring, as well as H-C-P protons in [P666,14]+, to oxygen and nitrogen atoms in the [NTf2]-. The new Dissolve data analysis package enabled, for the first time, the analysis of neutron scattering data of ILs with long alkyl chains, in particular, of [P666,14][NTf2]. Results generated with Dissolve were validated by comparing outputs from three different models, starting from three different sets of cation charges, for each of the three ILs, which gave convergent outcomes. Finally, a modified method for the synthesis of perdeuterated [P666,14][NTf2] has been reported, with the aim of reporting a complete set of synthetic and data processing approaches, laying robust foundations that enable the study of the phosphonium ILs family by neutron scattering.

A High-Throughput Experimental Approach to Screening Gas Sorption by Liquids and Solids

High-precision measurement of gas uptake from single or mixed feeds in solid and liquid sorbents traditionally requires time-consuming experimental procedures and/or complex and costly equipment. A simple and cost-effective headspace gas chromatography (HS-GC) approach for the fast, universal experimental screening of sorbents for gas uptake and/or determination of their real gas separation selectivity has been developed and is demonstrated for pressures up to 2500 mbar and temperatures above 30 °C. This method allows screening of solids and both volatile and nonvolatile liquid materials, physisorbents, and chemisorbents using both single and mixed permanent gases that can include CO2, CH4, H2, and NH3, for gas uptakes as low as 0.04 mmol or 1.8 mg of CO2. We estimate that this method allows for the screening of at least 30-96 sorbents (in triplicate) or 90-264 sorbents (singles) per day, representing at least a 90-3000 times reduction in the time required for equivalent analysis.

Insights into the Absorption of Hydrocarbon Gases in Phosphorus-Containing Ionic Liquids

The solubility of ethane, ethylene, propane, and propylene was measured in two phosphorus-containing ionic liquids, trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate, [P_6,6,6,14][DiOP], and 1-butyl-3-methylimidazolium dimethylphosphate, [C₄C₁Im][DMP], using an isochoric saturation method. The ionic liquid [C₄C₁Im][DMP] absorbed between 1 and 20 molecules of gas per 1000 ion pairs, at 313 K and 0.1 MPa, while [P_6,6,6,14][DiOP] absorbed up to 169 molecules of propane per 1000 ion pairs under the same conditions. [C₄C₁Im][DMP] had a higher capacity to absorb olefins than paraffins, while the opposite was true for [P_6,6,6,14][DiOP], with the former being slightly more selective than the later. From the analysis of the thermodynamic properties of solvation, we concluded that in both ionic liquids and for all of the studied gases the solvation is ruled by the entropy, even if its contribution is unfavorable. These results, together with density measurements, 2D NMR studies, and self-diffusion coefficients suggest that the gases' solubility is ruled mostly by nonspecific interactions with the ionic liquids and that the looser ion packing in [P_6,6,6,14][DiOP] makes it easier to accommodate the gases compared to [C₄C₁Im][DMP].

Hydration of sulfobetaine dizwitterions as a function of alkyl spacer length

The solvation and structure of bolaform dizwitterions containing two sulfobetaine moieties in concentrated aqueous solution were determined using neutron diffraction with isotopic substitution (NDIS) combined with modelling of the measured structure factors using Empirical Potential Structure Refinement (EPSR). Strongly directional local hydration was observed in the polar regimes of the dizwitterions with 48-52 water molecules shared between dizwitterion molecules in a first shell water network around each zwitterion pair. Overall, the double zwitterions were highly hydrated, providing experimental evidence in support of the potential formation of protein-resistant hydration layers at zwitterion-water interfaces.

New generation of supramolecular mixtures: Characterization and solubilization studies

In this work, a series of novel low melting mixtures (LMM) based on cyclodextrins (CD) and levulinic acid and inspired by the deep eutectic solvents (DES), were prepared. These supramolecular mixtures are the first reported CD-based mixtures that are liquid at room temperature. Density, viscosity and rheological measurements as well as differential scanning calorimetry and thermogravimetric analysis were performed to characterize these new LMM. Nuclear magnetic resonance (NMR) spectroscopy was used to monitor their stability. Furthermore, their ability to solubilize trans-anethole (AN) and related essentials oils were evaluated by static headspace-gas chromatography (SH-GC), in comparison with water. AN was up to 1300 times more soluble in the CD-based LMM than in water. Finally, multiple headspace extraction (MHE) was used to monitor the release of AN from these LMM. After 10 extractions, 20 to 40% of AN was released from the studied LMM, while 70% was released from water. The new CD-based LMM have potential applications for solubilization and delivery of poorly soluble drugs.

Frustrated Lewis pairs in ionic liquids and molecular solvents - a neutron scattering and NMR study of encounter complexes

The presence of the weakly-associated encounter complex in the model frustrated Lewis pair solution (FLP): tris(tert-butyl)phosphine (P(^tBu)₃) and tris(pentafluorophenyl)borane (BCF) in benzene, was confirmed via PB correlation analysis from neutron scattering data. On average, ca. 5% of dissolved FLP components were in the associated state. NMR spectra of the FLP in benzene gave no evidence of such association, in agreement with earlier reports and the transient nature of the encounter complex. In contrast, the corresponding FLP solution in the ionic liquid, 1-decyl-3-methylimidazolium bistriflamide, [C₁₀mim][NTf₂], generated NMR signals that can be attributed to formation of encounter complexes involving over 20% of the dissolved species. The low diffusivity characteristics of ionic liquids is suggested to enhance high populations of encounter complex. The FLP in the ionic liquid solution retained its ability to split hydrogen.

Characterization of Pseudomonas syringae pv. actinidiae biovar 3 on kiwifruit in north-west Portugal

AIMS

Bacterial kiwifruit canker disease, caused by Pseudomonas syringae pv. actinidiae (Psa) was detected in north-west Portugal in 2010, and has since caused significant losses. The objectives of this work were to characterize the Portuguese population(s) of Psa and to define the actual prevalence of Psa biovars in the most productive kiwifruit region in Portugal.

METHODS AND RESULTS

Isolates obtained from Actinidia deliciosa orchards were characterized by morphological, biochemical, physiological, fatty acids and molecular tests (PCR, BOX-PCR, duplex-PCR, multiplex-PCR and RFLP), phaseolotoxin, housekeeping and effector genes and pathogenicity. Results established that only Psa biovar 3 is present in the north-west of Portugal, despite phenotypic and genetic variability among the isolates.

CONCLUSIONS

This work provides new information on P. syringae pv. actinidiae (Psa) genetic profile in Portugal, indicating for the first time, that two genetically different subpopulations of Psa biovar 3 are present.

SIGNIFICANCE AND IMPACT OF THE STUDY

A new subpopulation of Psa biovar 3 was found for the first time in Portugal, contributing to increase knowledge about this population worldwide and to support further understanding of the impact of Psa.

Development and evaluation of a novel subunit vaccine for Mycoplasma gallisepticum

Adhesion proteins from Mycoplasma gallisepticum (MG) encoded by cytadhesion genes mgc1 and mgc2 were cloned into plasmid vectors and transformed into E. coli. Seventeen groups of specific-pathogen free (SPF), birds at four weeks of age were used to inoculate these two proteins (MGC1 and MGC2) mixed into an oil emulsion creating a novel MG vaccine. Six different protein concentrations (50, 100, 200, 400, 800, and 1000µg/bird) were tested with two equal concentration doses at four and seven weeks of age. In addition, many control groups were needed such as bacterin, membrane, no vaccine or challenge, oil emulsion alone, and no vaccine but challenged. Three weeks following the second vaccination, 50% of the birds in each treatment group were challenged with MG strain S6. The remaining birds were left as contacts to verify protection against horizontal transmission. All birds were bled before vaccinations, challenge and euthanasia. Birds were negative for MG at the first vaccination, as shown by serum plate agglutination test. At necropsy, tissue samples (trachea, lungs, and air sacs) were collected for histopathological examination. Swabs from trachea were used for PCR analysis. ELISA results showed a strong immune response to both protein preparations and almost the same response level for different doses tested, proving the immunogenic features of MGC1 and MGC2. However, humoral responses failed to prevent MG infection and disease when challenged as demonstrated by PCR and histopathology. MGC1 contact birds showed some degree of infection by PCR analysis. In addition, histopathological and ELISA results suggest that contact birds did not have enough time to develop lesions and to mount an immune response.

Preparation and characterization of low dispersity anionic multiresponsive core-shell polymer nanoparticles

We prepared anionic multistimuli responsive core-shell polymer nanoparticles with very low size dispersity. By using either acrylic acid (AA) or methacrylic acid (MA) as a comonomer in the poly(N-isopropyl acrylamide) (PNIPAM) shell, we are able to change the distribution of negative charges in the nanoparticle shell. The particle size, volume phase transition temperature, and aggregation state can be modulated using temperature, pH, or ionic strength, providing a very versatile platform for applications in sensors, medical diagnostics, environmental remediation, etc. The nanoparticles have a glassy poly(methyl methacrylate) (PMMA) core of ca. 40 nm radius and a cross-linked PNIPAM anionic shell with either AA or MA comonomers. The particles, p(N-AA) and p(MA-N), respectively, have the same total charge but different charge distributions. While the p(MA-N) particles have the negative charges preferentially distributed toward the inner shell, in the case of the p(N-AA) particles the charge extends more to the particle outer shell. The volume phase transition temperature (T(VPT)) of the particles is affected by the charge distribution and can be fine-tuned by controlling the electrostatic repulsion on the particle shell (using pH and ionic strength). By suppressing the particle charge we can also induce temperature-driven particle aggregation.

Parasites of stray cats (Felis domesticus L., 1758) on St. Kitts, West Indies

During 2005-2006, 100 stray cats on St. Kitts were examined using standard parasitological methods. Eggs identified were those of hookworms (88%), Trichuris spp. (71%), Eucoleus aerophillus (16%), Mammomonogamus spp. (45%), Physaloptera spp. (18%), Toxocara spp. (4%), Platynosomum spp. (81%) and taeniids (30%). Coccidian oocysts were found in 12% of the cats and Ctenocephalides felis found on 26%. When the direct fecal smear, benchtop flotation, modified double centrifugation, fecal sedimentation and adhesive tape/scotch tape methods were compared, the modified double centrifugation and benchtop flotation techniques detected most of the positive samples for the widest variety of parasites; 50% (Toxocara spp.) to 100% (hookworms) and 100% (Toxocara spp.) to 96% (hookworms), respectively.

Fluorescence of oligonucleotides adsorbed onto the thermoresponsive poly(isopropyl acrylamide) shell of polymer nanoparticles: Application to bioassays

The fluorescence of a rhodamine X dye covalently linked to the 5' terminus of a 25-mers thymine oligodeoxynucleotide (dT25-ROX), adsorbed on the shell of thermoresponsive core-shell polymer particles, was used to probe the polarity, mobility, and distribution of the oligodeoxynucleotides (ODNs) in the shell. The particles have a glassy core of poly(methyl methacrylate) (PMMA) with a 67-nm radius, and a thermoresponsive shell of poly(N-isopropyl acrylamide) (PNIPAM) whose thickness changes from 42 nm at 11 ºC to 5 nm at 45 ºC. The variation in polarity of the shell with temperature was obtained both from the lifetimes and from the solvatochromic shifts of the dye and shows a sharp transition at the volume phase transition temperature (TVPT) of the PNIPAM shell. Förster resonance energy transfer (FRET) between dT25-ROX and a malachite green (MG)-labeled ODN (dT25-MG) was used to obtain the distribution of the ODNs in the thermoresponsive shell. Our results show that at 23 ºC (belowTVPT) the ODNs are distributed inside the shell, sensing an environment similar to water. At this temperature, the PNIPAM shell is composed of hydrated chains with high mobility, as probed by the fluorescence anisotropy of dT25-ROX. By increasing the temperature aboveTVPT, the shell collapses and the chain mobility drastically slows down owing to the anchoring of the ODN to the dense shell of PNIPAM. Furthermore, FRET shows that the ODNs are absorbed on the 5-nm-thick collapsed shell but extend into the water. The polarity probed by the ROX averages the dyes distributed in the interior of the particle shell and in water, with 60 % of the dyes outside the particle shell (i.e., sensing pure water). Another indication that above theTVPTmost of the ODNs are oriented with the dye toward the water phase is that the mobility of the dye covalently bound to the ODNs is identical in water and in the collapsed particle shell. The hybridization efficiency between an ODN supported in the particle shell (by adsorbing the ODN belowTVPTand subsequently increasing the temperature aboveTVPT) and the complementary ODN in solution is identical to that of hybridization in water. This result opens good perspectives toward the use of the core-shell thermoresponsive nanoparticles as supports in DNA bioassays.

Day Hospital and Then…follow-up Two and a Half Years After the Hospitalization

Psychiatry Day Hospitals deal with a wide spectrum of disorders, being responsible for a psychosocial intervention that intends to improve patient's quality of life. The Psychiatry Day Hospital Department of Hospital de São João has thirty-eight years of activity, and has been one of the first in Portugal. The aim of this Psychiatry Unit, composed by a multidisciplinary team, is to prevent relapses and rehospitalisations, promoting the patients’ social rehabilitation, building a bridge between inpatient hospitalization and their re-entry into the community.

The primary objective of this cross-sectional study was to evaluate important aspects of service's quality, such as the use of health resources and results in functional terms. The authors made the follow-up of the patients that had been admitted in 2005 (Jan 2005 - Dez 2005; n= 77). For this purpose, it was assessed the number of attendances to the Emergency Department and hospitalizations two and a half years before and after the treatment in Day Hospital. It was also compared their current employment situation to that which preceded the Day Hospital care.

This study was performed in clinical setting among a reduced sample, with the inherent limitations. It would be appealing to replicate this investigation in a larger population and including some other variables.

Rinoplastia experimental com enxerto autógeno de costela em cães

O uso de costela autógena para correção de defeito criado no osso nasal em cães foi utilizado em 15 animais, separados em três grupos de pós-operatório, em que, após 30, 60 e 90 dias, finalizavam-se seus acompanhamentos. Cada grupo era composto de quatro animais enxertados e um animal-controle, no qual se utilizava o material do próprio defeito criado para coaptação. Os animais receberam monitoração clínica diária, e a integração do enxerto foi avaliada com exames radiográficos obtidos a cada 15 dias, quando se realizou o exame histológico. A técnica cirúrgica foi de fácil execução e possui praticidade em seu uso e foi suficiente para a correção de todos os defeitos criados. O efeito estético foi satisfatório, os exames radiográficos comprovaram a integração do enxerto, e a avaliação histológica evidenciou a presença de células compatíveis com a viabilização da técnica proposta.

Pathogenesis and tissue distribution of a variant strain of infectious bursal disease virus in commercial broiler chickens

The detection of either infectious virus, viral antigen, and/or viral RNA in different tissues of commercial broilers inoculated at 1 day of age with E/Del variant strain of infectious bursal disease virus (IBDV) was investigated at 2, 4, and 6 wk postinoculation (PI). Virus was readily isolated from homogenates of bursa, cecal tonsils, and bone marrow at 2 and 4 wk PI. Virus isolation coupled with immunoperoxidase assay or reverse transcription-polymerase chain reaction for IBDV-specific RNA extended the window of IBDV detection in the bursa of Fabricius to 6 wk PI. Serology indicated an active early virus infection; however, viral pathology was observed later and beginning at 4 wk PI. This study indicates that variant strains of IBDV may be present in commercial broilers longer than previously thought, and cecal tonsils and bone marrow may serve as nonbursal lymphoid tissues supporting virus replication at later time points PI.

[Experimental empyema in rats through intrapleural injection of bacteria]

OBJECTIVE: To evaluate empyema formation in rats through the injection of two bacteria (Pasteurella multocida and Staphylococcus aureus), using a simple, easy-to-use surgical technique. METHODS: Twenty four anesthetized Wistar white rats, 250-300g in weight, submitted to right anterior thoracotomy, muscular retraction and injection of a 0.2ml solution into pleural space according the following scheme: Group I (n=12): injection of 10(10) Pasteurella multocida cultured in brain heart infusion broth. Group II (n=8): injection of 10(10) Staphylococcus aureus cultured in brain heart infusion broth. Group III (n=4): injection of bacterium-free brain heart infusion (control). The rats were sacrificed after seven days, and pleural reaction was assessed by macroscopy. Mortality, and intrathoracic liquid volume were evaluated, and bacteriological tests were also performed. RESULTS: Seven rats died within the first 48 hours in Group I (Pasteurella multocida); five completed the experiment, but none of them presented empyema. Only one animal died within the first 24 hours in Group II (Staphylococcus aureus); seven (88%) presented empyema at the time of sacrifice. All animals survived in Group III (control), without empyema or thoracic abnormalities. Pleural inoculation of Staphylococcus aureus (Group II) was significantly associated with empyema formation (P<0.001). In this group, the amount of pleural liquid ranged from 0.9 to 3.9ml. CONCLUSION: It is possible to induce empyema in rats through Staphylococcus aureus pleural injection by a simple surgical technique. Differently from other experiments, the pleural injection of Pasteurella multocida did not provoke empyema in rats.

The Brazilian National Health Informatics Strategy

This paper describes the Brazilian National Strategy for the development of the national Health Informatics Infrastructure. An overall description of the use of IT in the Brazilian Health scenario is presented with emphasis on the federal initiatives by DATASUS, the informatics division of the Ministry of Health. The national health card project is discussed and the strategies to establish interoperability among systems are presented. The adopted standards and methodologies used are also discussed.

The software challenge for the next decade: the global objects scenario

This paper discusses the advantages of developing software as pattern-based components. The design and implementation of a pattern-based suite of software components specially constructed for the electronic patient record is presented. The methodology and the lessons learned in the development of these components are discussed. Finally, some comments about the globalization and the need for more integration among component developers in a worldwide basis is discussed.

[An increase in renal dopamine production after the administration of radiographic contrast agents]

Renal vasoconstriction and anti-natriuresis conditioned by radiographic contrast agents (CA) may be antagonised by the administration of exogenous dopamine. However, the influence of CA on the activity of renal synthesis of dopamine has not been studied. This study assessed the daily urinary excretion of dopamine, its precursor. L-3, 4-dihydroxyphenylaline (L-DOPA), and its metabolites (acid 3, 4-dihydroxyphenylacetic, DOPAC; homovanillic acid, HVA) 24 hours before and 48 hours following administration of a non ionic and hyposmolar (lopromide) CA in patients (n = 10; average age 61.3 +/- 4.3 years) submitted to coronary angiography. Urinary excretion of noradrenalin, a marker of sympathetic activity, was also assessed during the same period. The deputation of creatinine (Ccr) and the urinary excretion of sodium (UNa+) lowered after the administration of the CA (Ccr, 79.2 +/- 10.2 vs 72.2 +/- 9.6 ml/min/1.73 m2, p < 0.05; UNa+, 112.8 +/- 9.6 vs 61.7 +/- 25.1 mmol/24 h, p < 0.05). On the contrary, the urinary excretion of potassium increased in the period of 24 h following the administration of the AC (31.7 +/- 5.2 vs 103.8 +/- 10.8 mmol/24 h, p < 0.05). There was an increase in the urinary excretion of dopamine as well as noradrelalin during the 24 hour period following the administration of the CA (dopamine, 1260.2 +/- 196.8 vs 1571.5 +/- 170.2 mmol/24 h p < 0.5; noradrenalin, 186 +/- 36.6 mmol/24 h, p < 0.05). On the contrary, the urinary excretion of L-DOPA lowered after the administration of the CA (115.4 +/- 25.5 vs 80.5 +/- 13.2 mmol/24 h, p < 0.05). These results conditioned an increase in the dopamine/L-DOPA ratio in the urine, after the administration of the CA (12.2 +/- 1.5 vs 22.2 +/- 4.5 mmol/24 h, p < 0.05). In conclusion, the administration of CA is accompanied by an increase in the renal production of dopamine which, in these conditions, may act as a compensatory natriuretic hormone.

Renewing information infrastructure at Hospital das Clínicas

In this paper we describe the process of renewing the Informatics infrastructure of Sao Paulo University Medical School Hospital, a very complex environment. Our proposal consists of a change in the paradigm of Informatics and the use of Information Technology in the hospital. That change aims at making information available to the hospital, its managers, health care workers and patients. The paradigm change is reflected in every aspect of the new infrastructure: human resources, methods, and organizational structure, as we intend to demonstrate in this paper. This process is expected to be concluded by the end of this year, yielding benefits regarding costs, efficiency, and better patient care.

[Pharmacologic treatment of acute myocardial infarction: 2 large clinical trials at a central hospital]

OBJECTIVES

To analyse the clinical practice concerning the pharmacological therapy of acute myocardial infarction (AMI), comparing it with the guidelines for the management of AMI and exploring the reasons for its under use or over use.

METHODS

Retrospective analysis of clinical records of patients with the discharge diagnosis of AMI.

LOCATION

A central hospital in the North of Portugal.

SUBJECTS

One hundred and ninety-one patients admitted to the Internal Medicine Department of a central hospital in the North of Portugal between January 1, 1993, and December 31, 1994.

RESULTS

Thrombolytic therapy was performed in 24.1% of the patients. At discharge 32.6% of the patients were on therapy with beta blockers, 68% with angiotensin converting enzyme inhibitors (ACEI) and 88.4% with aspirin. Stepwise logistic regression produced the following odds ratios for the variables significantly associated with: a) thrombolytic therapy: hypertension - 0.38; non-Q wave infarction - 0.17; time between onset of symptoms and hospital admission greater than 6 hours - 0.18; admission to coronary unit - 14.72; b) beta blocker therapy: age > 60 years - 0.23; serum LDH > 1000 U/L - 0.41; diastolic blood pressure > 85 mmHg - 3.73; Killip > 1 - 0.08; concomitant therapy with calcium antagonist - 0.33; previous therapy with beta blocker - 14.87; hospital stay greater than 10 days - 2.67; c) ACEI therapy: anterior wall infarction - 3.07; non Q wave infarction - 0.13; congestive heart failure - 9.36; serum creatinine > or = 15 mg/dl - 0.03.

CONCLUSIONS

Beta blockers and thrombolytic are under used and ACEI overused. The delay in hospital admission is the most important factor opposing the use of thrombolytic therapy, imposing the need for measures that ean reduce this delay. Therapy with beta blockers (highly cost-effective) can be increased by educational intervention among the physicians. The overuse of ACEI can be ascribed to the good results of randomised trials.

[Cerebrospinal fluid in 50 AIDS patients]

Fifty AIDS patients were studied. All patients had anti-HIV antibodies (ELISA) present and met OPAS/Caracas punctuation criteria for AIDS cases in adults. Cerebrospinal fluid (CSF) analysis included pressure, cytology (number of cytomorphological aspects), total protein and electrophoresis, glucose and chloride concentration. Bacteriological and mycological investigations were performed as well as agglutination tests for Cryptococcus. Complement fixation, indirect immunoflorescence, passive hemagglutination and/or ELISA tests were performed for syphilis, toxoplasmosis, viral and fungal infections. All CSF analysis were made in the same laboratory following the same methodology. CSF was altered in 45 cases (90.0%) of the 50 patients studied. The most important alterations observed were: gammaglobulin (55.5%) and total protein (51.1%) increase, hypercytosis (48.9%) and decrease of chloride concentration (40.0%). HIV antibodies were detected in 42 patients (93.3%). Toxomoplamosis, isolated or associated to other agents, was the most frequent opportunistic infection (57.7%). Cerebrospinal fluid should always be examined in AIDS patients with or without neurological symptoms.

Lossy compression techniques, medical images, and the clinician

There has been increasing interest in the storage and retrieval of medical images in hospitals and clinics here in Brazil and elsewhere. At the Heart Institute of São Paulo, with thousands of image-based procedures performed each month, the pursuit of optimal transmission and storage methods for digital images is a major concern. The use of data-compression techniques can reduce the enormous amount of imaging data to be stored or transmitted across a computer network, so that the efficiency of the computing system is preserved. The techniques for image compression can be categorized as "lossless" or "lossy," with "lossy" techniques being those in which some, supposedly irrelevant information is lost. Lossy techniques are much more efficient than lossless ones, achieving data-compression ratios as high as 100:1.

Automatic assessment of scintmammographic images using a novelty filter

99mTc-sestamibi scintmammograms provide a powerful non-invasive means for detecting breast cancer at early stages. This paper describes an automatic method for detecting breast tumors in such mammograms. The proposed method not only detects tumors but also classifies non-tumor images as "normal" or "diffuse increased uptake" mammograms. The detection method makes use of Kohonen's "novelty filter". In this technique an orthogonal vector basis is created from a normal set of images. Test images presented to the detection method are described as a linear combination of the images in the vector basis. Assuming that the image basis is representative of normal patterns, then it can be expected that there should be no major differences between a normal test image and its corresponding linear combination image. However, if the test image presents an abnormal pattern, then it is expected that the "abnormalities" will show as the difference between the original test image and the image built from the vector basis. In other words, the existing abnormality cannot be explained by the set of normal images and comes up as a "novelty." An important part of the proposed method are the steps taken for standardizing images before they can be used as part of the vector basis. Standardization is the keystone to the success of the proposed method, as the novelty filter is very sensitive to changes in shape and alignment.

Hypermedia patient data retrieval and presentation through WWW

WWW can be a helpful tool for PACS and HIS data retrieval and presentation. The use of gateways to access both text and hypermedia databases (images and video) enables fetched data to be presented in virtually any computer system. WWW browsers provide a very friendly interface and require little training to operate. This paper presents a prototype that uses a SQL gateway for accessing relational patient databases. The dataset used here include text data from reports of diagnostic procedures as well as pointers to the corresponding images. Images can be displayed by the browsers' viewers.

HTLV-1 and myelopathy in Salvador (northeastern Brazil): a case control study

The principal aim of the study was to determine the degree of association between cerebrospinal fluid (CSF) that is positive for HTLV-1 and myelopathy in Salvador, Brazil. From the same hospital, twenty-eight cases of myelopathy and twenty-eight cases showing no neurological disorder were studied using blind selection matched 1:1 by age and sex. The twenty-eight pairs underwent HTLV-1 serology tests. In those with a positive result, anti-HTLV-1 antibodies were investigated in the CSF. The ELISA method was used, complemented by the Western-blot test. Myelopathy was considered associated with HTLV-1 only when the CSF was positive indicating neurotropism of the virus. The mean age of the cases was 44.6 +/- 15.6 years and the control group was 43.5 +/- 16.0 (p > 0.05). An OR of 9.0 was detected with a reliability interval (95%) of 1.652-48.866 and chi-square significant at the 0.02 level. Despite a strong degree of association and considering the low level of precision, there is a need for analytical studies with larger samples which besides improving the precision will allow for greater control of the confounding variables.

[Hemodynamic study with Swan-Ganz catheterization, concomitant to endomyocardial biopsy in heart transplantation patients. Importance in the early diagnosis of rejection]

PURPOSE

To evaluate the role of hemodynamic parameters in the diagnosis of acute rejection who underwent orthotopic cardiac transplantation.

METHODS

A protocol was carried out in 19 patients who underwent heart transplantation and in whom Swan-Ganz hemodynamics was performed immediately prior to routine endomyocardial biopsy in the first few months postoperatively. The results of 28 biopsies were divided in group I--severe rejection who needed pulse-therapy (n = 10) and group II--No or mild/moderate rejection who did not need any pulse (n = 18). Hemodynamic parameters were compared between both groups.

RESULTS

There were significant differences among hemodynamic parameters in groups I and II. Group I had higher mean right atrial pressures (13.0 x 7.3 mmHg), mean pulmonary pressure (26.3 x 20.4 mmHg), mean wedge pressure (14.4 x 10.9 mmHg) and lower cardiac index (2.57 x 3.10 l/min/m2).

CONCLUSION

In a routine situation, hemodynamic measurements, as obtained with Swan-Ganz catheter, simultaneously with endomyocardial biopsies, show significant alterations in transplanted patients who develop acute rejection. This information, obtained earlier than the biopsy results, could shorten the time to initiate pulse-therapy in patients with severe rejection.

Magnetic resonance imaging in HTLV-I associated myelopathy

Magnetic resonance imaging of the brain and spinal cord were carried out for seventeen consecutive patients with HTLV-1 associated myelopathy (HAM). Eight patients had brain abnormalities and four had decreased thoracic spinal cord diameter. Brain lesions were mostly located in subcortical and periventricular areas. Our data suggest that diffuse central nervous system lesions are present in patients with HAM.

Lossy compression in nuclear medicine images

The goal of image compression is to reduce the amount of data needed to represent images. In medical applications, it is not desirable to lose any information and thus lossless compression methods are often used. However, medical imaging systems have intrinsic noise associated to it. The application of a lossy technique, which acts as a low pass filter, reduces the amount of data at a higher rate without any noticeable loss in the information contained in the images. We have compressed images of nuclear medicine using the discrete cosine transform algorithm. The decompressed images were considered reliable for visual inspection. Furthermore, a parameter was computed from these images and no discernible change was found from the results obtained using the original uncompressed images.

Integrating Hospital Information Systems. The challenges and advantages of (re-)starting now

With the new technologies available today, more complex and useful Hospital Information Systems (HIS) can be designed and implemented. These new technologies have allowed that information from different sources and nature such as documents, images and signals be integrated within a single environment. Open standards, reliable networks, powerful hardware and software and lower prices are among the issues that make all this possible. One of the main issues is what to do with old systems that do not adhere to this new HIS concept. At the Heart Institute (InCor), a decision was made towards starting developing a new system called I3S. This paper gives a brief description of that system.