Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release.

OBJECTIVES: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition. METHODS: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489. Flexural strength was determined by 3-point bending test based on ISO 4049. Zn release/uptake was determined by atomic emission spectrometry; F release/uptake was measured using a F-specific electrode. Both release measurements were performed for 15 d before and 15 d after recharging. Antibacterial test was conducted according to agar plate methods against S. mutans, by measuring the inhibition halos in 1-h and 15-d specimens. Data were analyzed by ANOVA. RESULTS: Solubility increased with higher ZnSO(4) content, but remained below the ISO 7489 limit. Flexural strength was not affected by ZnSO(4) addition, and Vitremer performed better than Ketac-Fil. The control materials released no zinc. Vitremer with 10% ZnSO(4) released the highest amount of zinc. Fluoride release was similar for Ketac-Fil and Vitremer. In both cases, the highest amounts were released in the first 24 h. The growth inhibition halo of S. mutans was similar for both materials with highest content of ZnSO(4) and occurred only with 1-h specimens. SIGNIFICANCE: Zinc addition decreased microorganisms growth and improved fluoride release, without significantly affecting the materials' flexural strength and solubility.     

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.     

Nitrate administration to enhance the detection of myocardial viability by technetium-99m tetrofosmin single-photon emission tomography

A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with^99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction <40% underwent²⁰¹T1 rest-injection and^99mTc-tetrofosmin. baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake >50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of^99mTc-tetrofosmin at baseline correlated with that of 201T1 (r=0.82,P <0.001). On baseline^99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had <50% of peal. activity. Fifteen percent of these segments showed reversibility after nitrate administration, with an increase in^99mTc-tetrofosmin uptake from 40%±9% to 57%±9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on²⁰¹Tl studies, but 20 segments that were non-viable on^99mTc-tetrofosmin. studies were viable on²⁰¹Tl studies. Using a threshold value of >40% of peak activity, only seven segments remained non-viable on^99mTc-tetrofosmin studies. Overall agreement between^99mTc-tetrofosmin with nitrates and²⁰¹Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with^99mTc-tetrofosmin. was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies.     

Hypertension induction in Dahl rats

There is experimental and epidemiologic evidence that some minerals and trace elements play a role in hypertension. We designed an experiment in which salt and water sources were manipulated to examine the possible impact of this relationship. A strain of rats (Dahl rats) known to become hypertensive with sodium chloride ingestion was used to study the effect of salt source and water source on the induction of hypertension. The group on tap water and table salt had blood pressures (184 mmHg +/- 19) significantly higher than every other group in the experiment. The experimental animals receiving tap water plus table salt had the highest blood pressure levels, although they consumed the lowest quantity of sodium. Analysis of the tap water samples showed "soft water" by analysis of calcium and magnesium concentration. This could adversely affect blood pressure. The relatively high magnesium concentration in sun evaporated sea salt may play a protective role in hypertension induction. The zinc and copper present in tap water may play an exacerbating role.     

Monte Carlo dosimetric study of best industries and Alpha Omega Ir-192 brachytherapy seeds

Ir-192 seeds are widely used in the USA for low dose rate interstitial brachytherapy. There are two commercially available models: those manufactured by Best Industries filtered with stainless steel, and those manufactured by Alpha-Omega seeds filtered with Pt. Newly developed 3D correction algorithms for brachytherapy are based on dosimetry data obtained on unbounded phantom size, allowing corrections for heterogeneities and actual tissue boundaries. Published dosimetric datasets for both seeds have been obtained under bounded conditions. The aim of the present study is to obtain dosimetric datasets for these seeds under full scatter conditions. The Monte Carlo GEANT4 code has been used to estimate air-kerma strength and dose rate in water around the Ir-192 seeds. Functions and parameters following the TG43 formalism are obtained and presented in tabular forms: the dose rate constant, the radial dose function, and the anisotropy function. Tables for the anisotropy factor have been obtained in order to apply punctual approximation. Differences between dose rate distributions for both seeds show that specific dataset must be used for each type of seed in clinical dosimetry. The data in the present study improve on published data in the following aspects: (i) dosimetric data were obtained under full scatter conditions, which affect dose values at distances greater than 4-5 cm from the source; (ii) the dose rate tables are given at greater distances from the source; and (iii) the spatial resolution in high dose gradient areas, such as those near the longitudinal source axis, has been improved.     

Cutaneous phaeohyphomycosis caused by Alternaria longipes in an immunosuppressed patient.

Alternaria longipes was reported as the agent of a cutaneous infection in a patient with a neoplastic disease. The fungus has not been reported previously as causing disease in humans. It was distinguished by its rather small conidia with smooth or slightly verruculose walls and a pale brown beak which rarely extended into a secondary conidiophore. In vitro inhibitory activities of amphotericin B, ketoconazole, itraconazole, and miconazole were shown.     

Effect of using the flow or the volume signals on the measurement of nonapneic respiratory events

STUDY OBJECTIVES: To assess whether the measurement of breathing reduction during obstructive sleep events depends on using the flow or the volume signals recorded with a pneumotachograph. DESIGN: Prospective observational study. SETTING: Sleep laboratory in a University Hospital. PATIENTS OR PARTICIPANTS: Data from 10 male patients with sleep apnea (54 +/- 11 years, apnea-hypopnea index: 43 +/- 21 events/hour, body mass index: 30 +/- 2 kg/m2). INTERVENTIONS: Slow modification of continuous positive airway pressure was performed during full-polysomnography continuous positive airway pressure titration. MEASUREMENTS AND RESULTS: Air flow was measured by a pneumotachograph, and volume was computed by numerical integration. Obstructive events of different magnitude were selected. In 500 breathing cycles analyzed, the reduction in tidal volume was greater than the reduction in the flow amplitude: mean difference of 0.091 (i.e., 9.1% amplitude) and limits of agreement of 0.095 and -0.277 (i.e., 9.5% and -27.7% amplitude). In 14% of the cycles, the reduction in flow was < 50%, whereas the reduction in volume was > 50%, resulting in discordant event classification. CONCLUSIONS: The quantification of breathing reduction depends on whether the flow or the volume signal is used to assess breathing during sleep.     

Value of esophageal manometry with the methylergometrin maleate test in angina with normal coronarography. The concept of esophageal angina

22 patients presenting an "angina with normal coronarography" and 5 control subjects were subjected to a manometric exploration of the oesophagus in the basal state and under methylergometrine maleate (MEM) treatment. The MEM test is shown to be a good one for the induction of painful oesophageal dyskinesias, particularly in patients who had suffered in an inexplicable manner when that substance was administered for coronarography.