Unveiling the crystal and magnetic texture of iron oxide nanoflowers

Iron oxide nanoflowers (IONF) are densely packed multi-core aggregates known for their high saturation magnetization and initial susceptibility, as well as low remanence and coercive field. This study reports on how the local magnetic texture originating at the crystalline correlations among the cores determines the special magnetic properties of individual IONF over a wide size range from 40 to 400 nm. Regardless of this significant size variation in the aggregates, all samples exhibit a consistent crystalline correlation that extends well beyond the IONF cores. Furthermore, a nearly zero remnant magnetization, together with the presence of a persistently blocked state, and almost temperature-independent field-cooled magnetization, support the existence of a 3D magnetic texture throughout the IONF. This is confirmed by magnetic transmission X-ray microscopy images of tens of individual IONF, showing, in all cases, a nearly demagnetized state caused by the vorticity of the magnetic texture. Micromagnetic simulations agree well with these experimental findings, showing that the interplay between the inter-core direct exchange coupling and the demagnetizing field is responsible for the highly vortex-like spin configuration that stabilizes at low magnetic fields and appears to have partial topological protection. Overall, this comprehensive study provides valuable insights into the impact of crystalline texture on the magnetic properties of IONF over a wide size range, offering a deeper understanding of their potential applications in fields such as biomedicine and water remediation.

Selective anisotropic growth of Bi2S3 nanoparticles with adjustable optical properties

We report on the controlled synthesis and functionalization in two steps of elongated Bi₂S₃ nanoparticles within a wide range of sizes. First, we show the effect of the temperature and reaction time on the synthesis of two series of nanoparticles by the reaction of thioacetamide with bismuth(III) neodecanoate in the presence of organic surfactants. At 105 °C and long reaction times, nanoneedles of about 45 nm in length containing larger crystallites are obtained, while highly crystalline nanorods of about 30 nm in length are dominant at 165 °C, regardless of the reaction time. The optical properties of both types of nanoparticles show an enhancement of the band gap compared to bulk Bi₂S₃. This is likely to arise from quantum confinement effects caused by the small particle dimensions relative to the typical exciton size, together with an increase in near-infrared absorption due to the anisotropic particle shape. Second, a ligand exchange approach has been developed to transfer the Bi₂S₃ nanoparticles to aqueous solutions by grafting dimercaptosuccinic acid onto the surface of the particles. The as-prepared coated nanoparticles show good stability in water, in a wide biological pH range, and in phosphate-buffered saline solutions. Overall, this work highlights the controlled design at all levels - from the inorganic core to the organic surface coating - of elongated Bi₂S₃ nanoparticles, leading to a tunable optical response by tuning their morphology and size.

Atomic Force Manipulation of Single Magnetic Nanoparticles for Spin-Based Electronics

Magnetic nanoparticles (MNPs) are instrumental for fabrication of tailored nanomagnetic structures, especially where top-down lithographic patterning is not feasible. Here, we demonstrate precise and controllable manipulation of individual magnetite MNPs using the tip of an atomic force microscope. We verify our approach by placing a single MNP with a diameter of 50 nm on top of a 100 nm Hall bar fabricated in a quasi-two-dimensional electron gas (q2DEG) at the oxide interface between LaAlO₃ and SrTiO₃ (LAO/STO). A hysteresis loop due to the magnetic hysteresis properties of the magnetite MNPs was observed in the Hall resistance. Further, the effective coercivity of the Hall resistance hysteresis loop could be changed upon field cooling at different angles of the cooling field with respect to the measuring field. The effect is associated with the alignment of the MNP magnetic moment along the easy axis closest to the external field direction across the Verwey transition in magnetite. Our results can facilitate experimental realization of magnetic proximity devices using single MNPs and two-dimensional materials for spin-based nanoelectronics.

Survival study and factors associated with mortality in Chilean patients on peritoneal dialysis infected with SARS-CoV-2

The Covid-19 pandemic has been responsible for millions of deaths worldwide. Patients with comorbidities- such as those on peritoneal dialysis (PD)- present higher morbidity and mortality than the general population. We prospectively evaluated all Chilean patients on PD (48 centres) and followed those who had Covid-19 from the beginning of the Covid-19 pandemic in Chile (March 2020) to January 2021 (start of vaccination campaign). We described demographic history, comorbidities, factors related to infection, need for hospitalisation and death due to Covid-19. During the study period, 106 adults on PD were infected by SARS-CoV-2, with a mean age of 53.1 (±16.3) and of which 53.9% were female. From that group, 54.8% required hospitalisation and 24.5% (n = 26) died due to Covid-19. Most of the patients (63.4%) were infected at home and 22.8% during hospitalisation for other reasons. There was a significant association for Covid-19 mortality with: being ≥60 years old, diabetes, time on PD ≥5 years, need for hospitalisation and hospital-acquired infection. At 90 days of follow-up, all deaths associated to Covid-19 occurred before 40 days. We conclude that patients on PD without Covid-19 vaccination have a high mortality and need for hospitalisation associated to Covid-19. To avoid this negative outcome, it is necessary to intensify strategies to avoid contagion, especially in those ≥60 years old, with diabetes and/or ≥5 years spent on PD.

Selective Control over the Morphology and the Oxidation State of Iron Oxide Nanoparticles

Iron oxide nanoparticles (NPs) have been extensively used for both health and technological applications. The control over their morphology, crystal microstructure, and oxidation state is of great importance to optimize their final use. However, while mature in understanding, it is still far from complete. Here we report on the effect of the amount of 1,2-hexadecanediol and/or 1-octadecene in the reaction mixture on the thermal decomposition of iron(III) acetylacetonate in oleic acid for two series of iron oxide NPs with sizes ranging from 6 to 48 nm. We show that a low amount of either compound leads to both large, mixed-phase NPs composed of magnetite (Fe₃O₄) and wüstite (FeO) and high reaction yields. In contrast, a higher amount of either 1,2-hexadecanediol or 1-octadecene gives rise to smaller, single-phase NPs with moderate reaction yields. By infrared spectroscopy, we have elucidated the role of 1,2-hexadecanediol, which mediates the particle nucleation and growth. Finally, we have correlated the magnetic response and the structural features of the NPs for the two series of samples.

Accurate iron quantification in colloids and nanocomposites by a simple UV-Vis protocol

The selection and comparative study is reported of calibration curves to quantify iron by a simple UV-Vis protocol based on the formation of iron (III) chloride complexes. The reliability of each calibration curve was evaluated using statistical and analytical parameters. The robustness of each calibration curve using superparamagnetic iron oxide nanoparticles (SPIONs) of different sizes and surface functionalization is demonstrated . We have also evaluated the effect of the particle coating and estimated the minimum time to ensure the full oxidation of iron (II) to (III) in sample solutions. Results from UV-Vis are comparable with those obtained from ICP-OES and from other spectroscopic techniques to quantify the iron. We advocate the proposed protocol as a simple and non-expensive route to determine accurately the iron content in colloidal and nanocomposite iron-based materials. Graphical abstract.

Spin canting across core/shell Fe3O4/MnxFe3-xO4 nanoparticles

Magnetic nanoparticles (MNPs) have become increasingly important in biomedical applications like magnetic imaging and hyperthermia based cancer treatment. Understanding their magnetic spin configurations is important for optimizing these applications. The measured magnetization of MNPs can be significantly lower than bulk counterparts, often due to canted spins. This has previously been presumed to be a surface effect, where reduced exchange allows spins closest to the nanoparticle surface to deviate locally from collinear structures. We demonstrate that intraparticle effects can induce spin canting throughout a MNP via the Dzyaloshinskii-Moriya interaction (DMI). We study ~7.4 nm diameter, core/shell Fe₃O₄/Mn_xFe_3−xO₄ MNPs with a 0.5 nm Mn-ferrite shell. Mössbauer spectroscopy, x-ray absorption spectroscopy and x-ray magnetic circular dichroism are used to determine chemical structure of core and shell. Polarized small angle neutron scattering shows parallel and perpendicular magnetic correlations, suggesting multiparticle coherent spin canting in an applied field. Atomistic simulations reveal the underlying mechanism of the observed spin canting. These show that strong DMI can lead to magnetic frustration within the shell and cause canting of the net particle moment. These results illuminate how core/shell nanoparticle systems can be engineered for spin canting across the whole of the particle, rather than solely at the surface.

Paraoxonases: metabolic role and pharmacological projection

Atherosclerosis is one of the leading causes of death in Western countries, with high-density lipoproteins (HDL) playing an important protective role due to their ability to inhibit oxidation of low-density lipoproteins (LDL), thus relieving vascular subendothelial damage. One of the proteins constituting HDL particles is paraoxonase-1 (PON1), an enzyme able to hydrolyze aryl esters, lactones, and organophosphates. Other closely related paraoxonases are designated as PON2, which is a protein localized inside many different kinds of cells, and PON3, not only present in HDL but also in mitochondria and endoplasmic reticulum, as well. Given that the amount and the activity of PON1 in human serum are significantly lower in people suffering from cardiovascular diseases, enhancing both parameters might contribute to their treatment and prevention. One of the physiologically interesting substrates for the abovementioned hydrolytic cleavage is homocysteine thiolactone (HTL), an atherothrombotic active form of homocysteine. Although it was therefore postulated that PON1 would participate in preventing the HTL-mediated lipid peroxidation, some attention is recently paid to other enzymes, like biphenyl hydrolase-like protein, that seem to more selectively involved in lowering this risk factor. The aim of this paper is to elucidate the role of paraoxonases, especially PON1, by reviewing the latest studies in order to understand both its physiological role and modulation by drugs, nutrients, and plant extracts.

Is Microarray Analysis Really Useful and Sufficient to Diagnose Nut Allergy in the Mediterranean Area?

BACKGROUND

Component-based diagnosis on multiplex platforms is widely used in food allergy but its clinical performance has not been evaluated in nut allergy.

OBJECTIVE

To assess the diagnostic performance of a commercial protein microarray in the determination of specific IgE (sIgE) in peanut, hazelnut, and walnut allergy.

METHODS

sIgE was measured in 36 peanut-allergic, 36 hazelnut-allergic, and 44 walnut-allergic patients by ISAC 112, and subsequently, sIgE against available components was determined by ImmunoCAP in patients with negative ISAC results. ImmunoCAP was also used to measure sIgE to Ara h 9, Cora 8, and Jug r 3 in a subgroup of lipid transfer protein (LTP)-sensitized nut-allergic patients (positive skin prick test to LTP-enriched extract). sIgE levels by ImmunoCAP were compared with ISAC ranges.

RESULTS

Most peanut-, hazelnut-, and walnut-allergic patients were sensitized to the corresponding nut LTP (Ara h 9, 66.7%; Cor a 8, 80.5%; Jug r 3, 84% respectively). However, ISAC did not detect sIgE in 33.3% of peanut-allergic patients, 13.9% of hazelnut-allergic patients, or 13.6% of walnut-allergic patients. sIgE determination by ImmunoCAP detected sensitization to Ara h 9, Cor a 8, and Jug r 3 in, respectively, 61.5% of peanut-allergic patients, 60% of hazelnut-allergic patients, and 88.3% of walnut-allergic patients with negative ISAC results. In the subgroup of peach LTP-sensitized patients, Ara h 9 sIgE was detected in more cases by ImmunoCAP than by ISAC (94.4% vs 72.2%, P < .05). Similar rates of Cora 8 and Jug r 3 sensitization were detected by both techniques.

CONCLUSIONS

The diagnostic performance of ISAC was adequate for hazelnut and walnut allergy but not for peanut allergy. sIgE sensitivity against Ara h 9 in ISAC needs to be improved.

Superparamagnetic versus blocked states in aggregates of Fe(3-x)O₄ nanoparticles studied by MFM

Magnetic domain configurations in two samples containing small aggregates of Fe(3-x)O4 nanoparticles of about 11 and 49 nm in size, respectively, were characterized by magnetic force microscopy (MFM). Two distinct magnetic behaviors were observed depending on the particle size. The aggregates constituted of nanoparticles of about 11 nm in size showed a uniform dark contrast on MFM images, reflecting the predominant superparamagnetic character of these particles and arising from the coherent rotation of the spins within the aggregate as the latter align along the tip stray-field. By applying a variable in-plane field, it is possible to induce magnetic polarization yielding an increasing dark/bright contrast as the strength of the applied field overcomes the stray-field of the tip, although this polarization completely disappears as the remanent state is recovered when the magnetic field is switched off. On the contrary, for aggregates of NPs of about 49 nm in size, dark/bright contrast associated with the existence of magnetic domains and magnetic polarization prevails in MFM images all along the magnetic cycle due to the blocking state of the magnetization of these larger particles, even in the absence of an applied field. All in all, we unambiguously demonstrate the capabilities of magnetic force microscopy to distinguish between blocked and superparamagnetic states in the aggregates of magnetic nanoparticles. Micromagnetic simulations strongly support the conclusions stated from the MFM experiments.

A Comprehensive Comparison of the IEFPCM and SS(V)PE Continuum Solvation Methods with the COSMO Approach

Dielectric continuum models are popular for modeling solvent effects in quantum chemical calculations. The polarizable continuum model (PCM) was originally published exploiting the exact dielectric boundary condition. This is nowadays called DPCM. The conductor-like screening model (COSMO) introduced a simplified and slightly empirical scaled conductor boundary condition, which turned out to reduce the errors resulting from outlying charge. This was implemented in PCM as CPCM. Later, the integral equation formalism (IEFPCM) and the formally identical SS(V)PE model of Chipman introduced a modified dielectric boundary condition combining the dielectric exactness of DPCM with the reduced outlying charge sensitivity of COSMO. In this paper, we demonstrate on two huge data sets of neutral and ionic solutes that no significant difference can be observed between the COSMO and IEFPCM, if the correct scaling factor is chosen for COSMO.

Direct imaging of the magnetic polarity and reversal mechanism in individual Fe(3-x)O4 nanoparticles

This work reports on the experimental characterization of the magnetic domain configurations in cubic, isolated Fe3-xO4 nanoparticles with a lateral size of 25-30 nm. The magnetic polarity at remanence of single domain ferrimagnetic Fe3-xO4 nanoparticles deposited onto a carbon-silicon wafer is observed by magnetic force microscopy. The orientations of these domains provide a direct observation of the magneto-crystalline easy axes in each individual nanoparticle. Furthermore, the change in the domain orientation with an external magnetic field gives evidence of particle magnetization reversal mediated by a coherent rotation process that is also theoretically predicted by micromagnetic calculations.

Tuning the magnetic properties of Co-ferrite nanoparticles through the 1,2-hexadecanediol concentration in the reaction mixture

This work reports on the effect of the 1,2-hexadecanediol content on the structural and magnetic properties of CoFe₂O₄ nanoparticles synthesized by thermal decomposition of metal–organic precursors in 1-octadecene.

The effect of oleic acid on the synthesis of Fe3−xO4 nanoparticles over a wide size range

This work reports on the effect of the oleic acid concentration on the magnetic and structural properties of Fe_3−xO₄ nanoparticles synthesized by thermal decomposition of Fe(acac)₃ in benzyl-ether.

SiO2 coating effects in the magnetic anisotropy of Fe3-xO4 nanoparticles suitable for bio-applications

We present radio frequency transverse susceptibility (TS) measurements on oleic acid-coated and SiO2-coated Fe3-xO4 magnetite nanoparticles. The effects of the type of coating on the interparticle interactions and magnetic anisotropy are evaluated for two different particle sizes in powder samples. On the one hand, SiO2 coating reduces the interparticle interactions as compared to oleic acid coating, the reduction being more effective for 5 nm than for 14 nm diameter particles. On the other hand, the magnetic anisotropy field at low temperature is lower than 1 kOe in all cases and independent of the coating used. Our results are relevant concerning applications in biomedicine, since the SiO2 coating renders 5 and 14 nm hydrophilic particles with very limited agglomeration, low anisotropy, and superparamagnetic behavior at room temperature. The TS technique also allows us to discriminate the influence on the anisotropy field of interparticle interactions from that of the thermal fluctuations.

Validity of ultrasonography and measures of adult shoulder function and reliability of ultrasonography in detecting shoulder synovitis in patients with rheumatoid arthritis using magnetic resonance imaging as a gold standard

OBJECTIVE

To assess the intra- and interobserver reproducibility of musculoskeletal ultrasonography (US) in detecting inflammatory shoulder changes in patients with rheumatoid arthritis, and to determine the agreement between US and the Shoulder Pain and Disability Index (SPADI) and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, using magnetic resonance imaging (MRI) as a gold standard.

METHODS

Eleven rheumatologists investigated 10 patients in 2 rounds independently and blindly of each other by US. US results were compared with shoulder function tests and MRI.

RESULTS

The positive and negative predictive values (NPVs) for axillary recess synovitis (ARS) were 0.88 and 0.43, respectively, for posterior recess synovitis (PRS) were 0.36 and 0.97, respectively, for subacromial/subdeltoid bursitis (SASB) were 0.85 and 0.28, respectively, and the NPV for biceps tenosynovitis (BT) was 1.00. The intraobserver kappa was 0.62 for ARS, 0.59 for PRS, 0.51 for BT, and 0.70 for SASB. The intraobserver kappa for power Doppler US (PDUS) signal was 0.91 for PRS, 0.77 for ARS, 0.94 for SASB, and 0.53 for BT. The interobserver maximum kappa was 0.46 for BT, 0.95 for ARS, 0.52 for PRS, and 0.61 for SASB. The interobserver reliability of PDUS was 1.0 for PRS, 0.1 for ARS, 0.5 for BT, and 1.0 for SASB. P values for the SPADI and DASH versus cuff tear on US were 0.02 and 0.01, respectively; all other relationships were not significant.

CONCLUSION

Overall agreements between gray-scale US and MRI regarding synovitis of the shoulder varied considerably, but excellent results were seen for PDUS. Measures of shoulder function have a poor relationship with US and MRI. Improved standardization of US scanning technique could further reliability of shoulder US.

Ultrasound in rheumatology. The Mexican experience

Over the last few years, a growing number of rheumatologists has taken great interest in ultrasonography for its well known advantages and wide spectrum of validated applications in daily rheumatological practice. Most rheumatologists actively performing ultrasonography have had a training experience mainly based on attendance in sonographic courses and/or in radiological or rheumatological units. At present, in Mexico ultrasonography has a still limited diffusion among rheumatologists even if it may play a key role as a first line imaging technique also because of the restricted availability for rheumatic patients for other imaging modalities. This report describes the Mexican experience in education and training on musculoskeletal ultrasound. In 2003, the Mexican School of Musculoskeletal Ultrasound of the Mexican College of Rheumatology (ECOMER) was founded with the intention of joining efforts to launch musculoskeletal ultrasound in Mexico. Essential requirements shared by all the members of ECOMER include: to own an ultrasound machine, to incorporate ultrasonography into clinical daily practice and to keep up-to-date in musculoskeletal ultrasound. The motto of ECOMER is una clara imagen de la reumatologia which means a clear picture of rheumatology. The statute of ECOMER can be read in its web site: www.ecomer.org.mx. This web site also provides a forum for case discussion, consultation and image review.

Impacto de una intervención de autoevaluación clínica sobre la adecuación de la estancia hospitalaria

AIM

To assess the impact of an intervention on inappropriate hospital stays (IHS) in acute-care hospitals in Catalonia (Spain) with the aim of testing the hypothesis that a simple intervention (adeQhos) reduces the proportion of IHS.

METHODS

A pre-test/post-test study was performed through the <<adeQhos>> questionnaire. Two intervention groups (internal medicine and general surgery) and 2 control groups (other medical specialities, orthopedics) were compared in 10 acute-care hospitals in Catalonia. The same evaluators assessed appropriateness of hospital stays before and after the intervention, using the Appropriateness Evaluation Protocol.

RESULTS

A total of 1,594 pre-test stays and 1,495 post-test stays were reviewed. Of all the stays reviewed (day before discharge), 41.1% were inappropriate. The intervention was applied to 4,613 stays. There was a significant increase of IHS in the medicine control group (from 39.7 to 48.6%), and no decrease in the intervention groups (internal medicine [from 46.7 to 50.6%] or general surgery [from 27.2 to 31.2%]). The correlation between the intensity of the intervention and the difference in IHS before and after the intervention was r = -0.373 (p = 0.106). The intensity of intervention differed among the hospitals. In hospitals with an intensity of intervention > 60%, the proportion of IHS decreased by 10.7 points in internal medicine and by 4.8 points in general surgery, while the proportion of IHS increased in the control groups.

CONCLUSIONS

The prevalanece of IHS the day before discharge in the hospitals studied was high (41.1%). No significant decrease in IHS was observed after a low-intensity intervention.

Epidemiologic evidence of transmission of donor-related bacterial infection through a transplanted heart

This study describes a patient who had fulminant infectious myocarditis as a result of methicillin-resistant Staphylococcus aureus after receiving a heart transplant from an infected donor. There was complete concordance of typing results between donor and recipient strains that were different from the 20 isolates with which they were compared. Molecular epidemiologic study provided compelling evidence that a transplanted organ can transmit a bacterial infection from the donor to the recipient.

Spectrum of alcohol-induced myocardial damage detected by indium-111-labeled monoclonal antimyosin antibodies

OBJECTIVES

We sought to determine the prevalence, intensity and evolving changes of myocardial damage detected by myocardial uptake of antimyosin antibodies in patients with alcohol-induced dilated cardiomyopathy, alcohol addicts attending a detoxification unit and healthy subjects with short-term alcohol consumption.

BACKGROUND

Evidence of alcohol-induced myocardial damage may be provided by myocardial uptake of indium-111-labeled monoclonal antimyosin antibodies. The spectrum of such damage in patients who are heavy drinkers (> 100 g for > 10 years), with or without cardiomyopathy, and the impact of short-term alcohol ingestion on antimyosin antibody uptake have not been adequately explored.

METHODS

One hundred twenty antimyosin studies were performed in 56 patients with dilated cardiomyopathy (group I), 15 alcohol addicts attending a detoxification unit (group II) and 6 volunteers for short-term alcohol ingestion (group III). Estimation of antibody uptake was calculated through a heart/lung ratio (HLR) (normal < 1.55).

RESULTS

The 56 patients in group I (54 men, 2 women; mean [+/-SD] age 46 +/- 11 years) had consumed 123 +/- 60 g/day of alcohol for 21 +/- 9 years, for a cumulative intake of 914 +/- 478 kg. Mean duration of symptoms was 46 +/- 49 months. Mean left ventricular end-diastolic diameter was 71 +/- 10 mm, and mean ejection fraction was 28 +/- 12%. No differences in New York Heart Association functional class, ventricular size or ejection fraction were noted between 28 active and 28 past consumers, except for the prevalence and intensity of antibody uptake (75% vs. 32%, p < 0.001) and HLR (1.75 +/- 0.26 vs. 1.49 +/- 0.17, p = 0.0001). In 19 patients in the active group restudied after alcohol withdrawal, antibody uptake decreased (from 1.76 +/- 0.17 to 1.55 +/- 0.19, p < 0.001), and ejection fraction improved (from 30 +/- 12% to 43 +/- 16%, (p < 0.001). No changes occurred in the 15 past consumers restudied. The 15 male patients in group II (mean age 36 +/- 4 years) had consumed 156 +/- 59 g/day for 17 +/- 5 years, for a cumulative alcohol intake of 978 +/- 537 kg, an amount similar to that in patients in group I, but antimyosin antibody uptake was detected in only 3 (20%) of 15 patients. None of six group III subjects developed antibody uptake after short-term ethanol ingestion. Despite the small sample size, the power to detect clinically relevant differences in most variables that did not reach statistical significance was amply sufficient.

CONCLUSIONS

In alcohol-induced dilated cardiomyopathy, alcohol withdrawal is associated with the reduction or disappearance of myocardial damage and improvement of function. The difference in prevalence of antimyosin antibody uptake in patients with and without cardiac disease who consume similar amounts of alcohol suggests the presence of those with different myocardial susceptibilities to alcohol. Short-term ethanol ingestion in healthy subjects does not induce detectable uptake of antimyosin antibodies.

Nursing protocol for manipulation of haemodialysis catheters

This study looked at the incidence of infection complications, in relation to central vein catheterisation as a provisional HD access, by means of the establishment of a nursing protocol for the handling of these catheters. Central vein catheterisation is a classical technique in Nephrology.

Enterovirus persistence and myocardial damage detected by 111In-monoclonal antimyosin antibodies in patients with dilated cardiomyopathy

BACKGROUND

Patients with dilated cardiomyopathy in whom enteroviruses in the myocardium are detected are more likely to die than those in whom no viruses have been demonstrated. The presence of enterovirus RNA in the myocardium at endomyocardial biopsy has been shown to be the strongest predictor of reduced survival. These results raise the question as to whether persistent virus might be responsible for continuing myocardial damage. Detection of myocardial cell damage is assessed using 111Indium-labelled monoclonal antimyosin antibodies. The present study was undertaken to address the question of whether the presence of myocardial cell damage by such antibodies in patients with dilated cardiomyopathy can be correlated with enterovirus persistence.

PATIENTS AND METHODS

A series of 19 consecutive patients diagnosed as having chronic dilated cardiomyopathy who were referred for evaluation for heart transplantation were studied with 111Indium labelled monoclonal antimyosin antibodies. These patients and 10 controls were screened for enterovirus RNA sequences in endomyocardial biopsy tissue by hybridization with an enterovirus group-specific cDNA probe.

RESULTS

Antimyosin uptake, indicative of myocardial cell damage, was observed in 16 of 19 patients (84%), with dilated cardiomyopathy, and enterovirus RNA sequences were detected in endomyocardial biopsies from four of these 16 patients (25%), but not in myocardium from the remaining three patients with a negative antimyosin scan, nor from any of 10 controls.

CONCLUSIONS

Although these data do not establish a causal relationship between virus persistence in the myocardium and myocardial damage, the results obtained in the preliminary study support the hypothesis that enterovirus persistence is associated with continuing myocardial damage in patients with dilated cardiomyopathy.

Epidemic outbreak of interstitial lung disease in aerographics textile workers--the "Ardystil syndrome": a first year follow up

BACKGROUND

The longer term respiratory effects of massive inhalational exposure of textile printing sprayers to Acramin (the "Ardystil syndrome") are not well established.

METHODS

A 12 month follow up of 27 heavily exposed textile sprayers was performed.

RESULTS

Twenty one patients experienced cough, 18 dyspnoea, and 17 nose bleeding at initial exposure, with histological evidence of organising pneumonia in 13 cases, radiological abnormalities detected by computed tomographic scanning in 20 cases, and diminution of diffusion capacity to below 80% of predicted in seven cases. At one year after exposure symptoms persisted in 15 cases, radiological alterations in six, and diffusion capacity was reduced in nine.

CONCLUSIONS

Whilst most of our patients showed improvement at one year, evidence of persistent lung involvement was present in an appreciable minority of exposed cases.

Active myocardial damage in hyperthyroidism. A concurrent mechanism of heart failure reversed by treatment

A patient with hyperthyroidism, heart failure, and depressed ejection fraction, in whom myocardial damage was evidenced by In111-labelled monoclonal antimyosin antibodies, is presented. Both myocardial damage and left ventricular dysfunction disappeared after antithyroid therapy. This suggests that, in addition to volume overload, heart failure in hyperthyroidism could be also due to the presence of potentially reversible concurrent myocardial damage.

Reversal of dilated cardiomyopathy after chronic tricyclic antidepressant drug withdrawal

Two patients referred for heart transplantation for dilated cardiomyopathy on chronic tricyclic antidepressant treatment are described. Echocardiographic normalization of left ventricular diameters and function were evidenced after drug withdrawal, suggesting drug-induced toxic myocardial disease. The possibility of functional improvement after tricyclic antidepressant drug withdrawal should be kept in mind before including patients with dilated cardiomyopathy in a heart transplantation program.

Outbreak of organising pneumonia in textile printing sprayers. Collaborative Group for the Study of Toxicity in Textile Aerographic Factories

Eight textile printing factories in Valencia, Spain, with a total workforce of 257 using spraying techniques were investigated as a result of severe interstitial lung disease occurring in three employees, one of whom died. Clinical and radiological data together with biopsy specimens from 71 (27.6%) workers with abnormal respiratory features indicated the occurrence of an outbreak of organising pneumonia resulting in 6 deaths. Epidemiological analysis included the 22 workers who fulfilled the radiological case definition based on chest radiograph and computed tomographic scan showing widespread nodular opacities or confluent patchy consolidation with a lung biopsy corresponding to organising pneumonia. The overall attack rate was 8.9%. Only 2 of the 22 cases never worked in factories A or B. Those who had only worked in factory A had the highest risk of being a case (RR = 24.3; 95% CI = 5.7-104.4). The relationship of case status to period of employment suggested an abrupt change in exposure conditions in the period when Acramin FWR was substituted by Acramin FWN. Although the precise toxicological mechanism is unknown, it is proposed that the lung disease was caused by spraying procedures delivered a respirable aerosol of Acramin FWN to distal airways and pulmonary parenchyma.

Presence, evolving changes, and prognostic implications of myocardial damage detected in idiopathic and alcoholic dilated cardiomyopathy by 111In monoclonal antimyosin antibodies

BACKGROUND

The clinical relevance of myocardial cell damage in dilated cardiomyopathy is uncertain. Myocardial uptake of 111In monoclonal antimyosin antibodies (MAA) was used to study myocardial damage in patients with idiopathic (IDC) and alcoholic (ADC) dilated cardiomyopathy and to assess its prognostic implications.

METHODS AND RESULTS

MAA and echocardiographic studies were performed in 117 patients. Intensity of antibody uptake was measured by heart-to-lung ratio (HLR) (normal < 1.55). Studies were repeated in survivors and patients who did not receive a cardiac transplant. Follow-up extended up to 62 months (mean, 23 +/- 16 months). Eighty-eight patients with IDC showed a 77% prevalence of abnormal MAA. After acute-onset IDC, reduction of HLR (1.81 +/- 0.2 to 1.56 +/- 0.1) (P = .007) with improvement in ejection fraction (EF) (35 +/- 10% to 46 +/- 14%) (P = .018) was observed. No changes in HLR or EF were detected in patients with chronic stable IDC. Twenty-nine patients with ADC showed a lower prevalence (48%) of abnormal MAA studies than those with IDC (P = .003). HLR was higher in 13 active (1.78 +/- 0.3) than in 16 past consumers (1.49 +/- 0.2) (P = .019); in the former, HLR decreased to 1.44 +/- 0.2 (P = .012), and EF improved (35 +/- 14% to 53 +/- 18%) (P = .05) after abstention. Intensities of uptake HLR of > 1.87 were associated with increased risk of death or transplantation.

CONCLUSIONS

In patients with IDC, variations of MAA uptake are detected in patients who present acutely but not in those with chronic stable disease. In patients with ADC, MAA uptake mainly depends on alcohol consumption. In both situations, reduction of uptake correlates with improvement of ventricular function. Higher intensities of MAA uptake are associated with a worse outcome. The intensity of antibody uptake, along with other clinical and functional variables, may be helpful in risk stratification of patients with dilated cardiomyopathy.

[Percutaneous coronary transluminal angioplasty in a heart transplant recipient]

A 46-year-old female, who underwent an orthotopic heart transplantation 5 years ago, presented an occlusive coronary artery disease with severe stenosis of the left anterior descending artery and a large septal perforator. An isonitrile scintigraphy showed a decreased uptake involving the anterior and inferior segments of the left ventricle. Percutaneous transluminal coronary angioplasty was successfully performed in both lesions. Three months after dilatation, improvement of the uptake in both myocardial segments was detected. The results of the percutaneous transluminal coronary angioplasty published in the literature are reviewed.

Early postoperative reduction of monoclonal antimyosin antibody uptake is associated with absent rejection-related complications after heart transplantation

BACKGROUND

Detection and treatment for rejection after transplantation are based on the identification of myocyte damage upon endomyocardial biopsy. Noninvasive detection of such damage is possible with 111In-labeled monoclonal antimyosin antibodies (MAA). Although the presence and degree of MAA uptake parallels the rejection activity detected by biopsy, the relation between the degree of uptake and the occurrence of severe rejection-related complications has not been previously assessed.

METHODS AND RESULTS

Two hundred forty-seven MAA studies were performed coinciding with biopsies in 52 patients 1-71 months after transplantation. A heart-to-lung ratio (HLR) was used as a measure of relative MAA uptake, with an HLR of 1.55 discriminating normal from abnormal studies. Of the 247 antimyosin studies, 149 coincided with absent, 38 with mild, and 60 with moderate rejection at biopsy. HLR was 1.68 +/- 0.27, 1.79 +/- 0.22, and 1.91 +/- 0.33 in the three biopsy groups, respectively (p less than 0.0001). Two hundred thirty-eight of 247 antimyosin studies coexisted with absent rejection-related complications; in nine of 247 patients, such complications were detected (five congestive heart failure episodes due to rejection and four episodes of vascular occlusion, which resulted in five deaths), and mean HLR was 1.74 +/- 0.3 and 2.1 +/- 0.16 in the two groups, respectively (p less than 0.0001). No complications were noted in 193 studies of patients with HLR of less than 2.00, whereas in nine of 45 with HRL of 2.00 or greater, complications occurred (p less than 0.0001). None of the 23 patients prospectively followed since surgery who had a gradual decrease in MAA uptake during the first 3 months showed rejection-related complications, whereas persistent uptake was associated with complications in five of nine patients (p less than 0.001).

CONCLUSIONS

No rejection-related complications are seen coinciding with HLR of less than 2.00, whereas patients who have complications have an HLR of more than 2.00. The early 3-month pattern of decreasing MAA uptake is associated with a clinical course free of rejection-related complications, whereas a persistent pattern is a signal of the possibility of such complications.