Atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry of engine oil additive components.

RATIONALE: The efficiency of lubricants strongly depends on the content of functional additives. In order to assess the chemical and structural changes taking place in the lubricating oil and its additives during operation, it is essential to develop a method for simple and prompt analysis. METHODS: Two single additives as well as a fully formulated engine oil were analysed using an atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) source coupled to a linear trap quadrupole Orbitrap XL hybrid tandem mass spectrometer and compared with results obtained by means of electrospray ionization (ESI) including additional low-energy collision-induced dissociation (LE-CID). The identification of additives directly from technical surfaces was simulated by using steel substrates as AP-MALDI targets with varying roughness. RESULTS: After assessment and selection of the most suited AP-MALDI matrix it was found that pure additives such as calcium sulfonate and zinc dialkyldithiophosphates (ZDDPs) could well be identified with abundant signal intensity based on their elemental composition. Molecular identification was corroborated by LE-CID in ESI mode. Additionally, additives present in the fully formulated commercial oil such as ZDDPs and salicylates could be reliably identified based on the elemental composition of the deprotonated molecules by means of the Orbitrap unit on different substrates including steel surfaces with high roughness. CONCLUSIONS: AP-MALDI is an efficient technique for determination of lubricant additives directly from commercial oil blends. Identification of additive components was also achieved on steel surfaces with high roughness as applied in tribological systems and thus it is expected that it will be possible to assess additive degradation in real applications, enabling more effective and timely maintenance measures.

Calculation of left ventricular volumes and systolic indices in monitoring the therapeutic effect of levothyroxine replacement therapy in subclinical hypothyroidism.

BACKGROUND/AIM: Subclinical hypothyroidism (SCH) is defined as high thyroid-stimulating hormone (TSH) and normal thyroxine (T4) levels. Data on the effects of early substitution with levothyroxine on psychophysical health in SCH are not consistent enough to support its general administration. The aim of this study was to examine the effect of 3-months levothyroxine (LT4) treatment on cardiovascular function in symptomatic SCH with TSH <10 mIU/L. METHODS: Anthropometric, biochemical, electro- and echocardiographic indices were measured in 35 patients with persistent symptomatic SCH (4 mIU/L < TSH <10 mIU/L; mean ± SD: 7.0 ± 2.1 mIU/L) and 40 healthy controls at baseline and three months after the euthyroid state had been achieved on LT4 for SCH group, or 3 months of follow-up for controls. RESULTS: The analyses showed a significant reduction in body weight (P = .030), systolic and diastolic blood pressure (P = .024, P = .019), TSH (P < .001) and thyroid peroxidase antibodies (TPO Ab) (P < .001) on LT4 in the SCH group. There was a statistically significant decrease in end-systolic (ESV) and end-diastolic volumes (EDV) (P < .001, P < .001, respectively) after LT4 treatment. LT4 therapy significantly increased values of ejection fraction (EF), global longitudinal, circumferential and radial strains (P < .001, P < .001, P < .001, respectively). CONCLUSIONS: Our study confirmed an echocardiographic improvement of cardiac structure and function in treated individuals. Findings suggest the role of electrocardiographic and echocardiographic examination in objective monitoring for LT4 therapeutic effects.

Diagnostic significance of three-dimensional echocardiography in asymptomatic unicuspid aortic valve.

Unicuspid aortic valve (UAV) is a rare congenital anomaly of aorta associated with a faster progress of valvular dysfunction, aortic dilatation and with necessity for more frequent controls and precise evaluation Asymptomatic 35 year old man had abnormal systolic diastolic murmur on aortic valve during routine examination. Initial diagnostic with transthoracic echocardiography (TTE) supposed bicuspid aortic valve, while three-dimensional transesophageal echocardiography (3D TEE) and multidetector computed tomography defined unicuspid, unicomissural aortic valve with moderate aortic stenosis and regurgitation. This case report confirmed that 3D TEE gives us opportunity for early, improved and precise diagnosis of UAV.

Modified-Atmospheric Pressure-Matrix Assisted Laser Desorption/Ionization Identification of Friction Modifier Additives Oleamide and Ethoxylated Tallow Amines on Varied Metal Target Materials and Tribologically Stressed Steel Surfaces.

For many tasks in failure and damage analysis of surfaces deteriorated in heavy tribological contact, the detailed characterization of used lubricants and their additives is essential. The objective of the presented work is to establish accessibility of tribostressed surfaces for direct characterization via modified atmospheric pressure-matrix assisted laser desorption/ionization-mass spectrometry (m-AP-MALDI-MS). Special target holders were constructed to allow target samples of differing shape and form to fit into the desorption/ionization chamber. The best results of desorption and ionization on different target materials and varying roughnesses were achieved on smooth surfaces with low matrix/substrate interaction. M-AP-MALDI characterization of tribologically stressed steel surfaces after pin-on-disc sliding wear tests (SRV-tribotests) yielded positive identification of used friction modifier additives. Further structure elucidation by electrospray ionization mass spectrometry (ESI-MS) and measurements of worn surfaces by time-of-flight-secondary ion mass spectrometry (TOF-SIMS) accompanied findings about additive behavior and deterioration during tribological contact. Using m-AP-MALDI for direct offline examinations of worn surfaces may set up a quick method for determination of additives used for lubrication and general characterization of a tribological system.

Effects of a short-term differently dosed aerobic exercise on maximum aerobic capacity in breast cancer survivors: a pilot study.

BACKGROUND/AIM: Regular physical activity and exercise improves quality of life and possibly reduces risk of disease relapse and prolongs survival in breast cancer survivors. The aim of this study was to evaluate the impact of a 3-week moderate intensity aerobic training, on aerobic capacity (VO2max) in breast cancer survivors. METHODS: A prospective, randomized clinical study included 18 female breast cancer survivors in stage I-IIIA, in which the primary treatment was accomplished at least 3 months before the study inclusion. In all the patients VO2max was estimated using the Astrand's protocol on a bicycle-ergometer (before and after 3 weeks of training), while subjective assessment of exertion during training were estimated by the Category-Ratio RPE Scale. Each workout lasted 21 minutes: 3 minutes for warm-up and cool-down each and 15 min of full training, 2 times a week. The workload in the group E1 was predefined at the level of 45% to 65% of individual VO2max, and in the group E2 it was based on subjective evaluation of exertion, at the level marked 4-6. Data on the subjective feeling of exertion were collected after each training course in both groups. RESULTS: We recorded a statistically significant improvement in VO2max in both groups (E1--11.86%; E2--17.72%), with no significant differences between the groups. The workload level, determined by the percent of VO2max, was different between the groups E1 and E2 (50.47 +/- 7.02% vs 55.58 +/- 9.58%), as well as subjective perception of exertion (in the groups E1 and E2, 11.6% and 41.6% of training, respectively, was graded in the mark 6). CONCLUSION: In our group of breast cancer survivors, a 3-week moderate intensity aerobic training significantly improved the level of VO2max.

[Impact of heart myxoma localization upon its clinical course and outcome].

INTRODUCTION: Primary heart tumors are very rare. They can be benign and malignant. Benign ones make about two thirds of all heart tumors. However, they are benign only by their biologic characteristics, but potentially malignant by their localization. About three forths of benign tumors are myxomas. Their growth is usually slow and they can be for a long time silent, particularly if they do not compromise vital functional parts of the heart. Myxomas grow in the atria, mostly in the left one and very rarely in the ventricles. CASE REPORT: We presented two patients with myxomas in the left, and, in the right atrium which are representative samples of the most common localization of heart myxoma considering previous knowledge of these tumors. Analysis of the clinical course in the two presented patients with characteristic localizations showed general characteristics of the clinical course of heart myxoma. The patients did not have characteristic symptoms for a rather long period of time and the findings obtained by standard examinations did not raise suspicion of heart tumor. Pulmonary symptomatology in one patient and cardial in the other, when tumor had already occupied almost the entire atrium, suggested necessity of cardiologic examination. Indication for operation was in both patients confirmed after performed echocardiography, computed tomography of the thorax and angiography with ventriculography. The size of the removed atrial tumors and their localization explained some of the patients' troubles, but it was also amazing that they had not caused more serious problems. Operation as the only method of treatment was successful in both female patients and its effect was permanent. At annual controls neither recurrence of the tumor nor troubles possibly associated with it were observed. CONCLUSION: Patients with heart myxoma usually pass through asymptomatic or oligosymptomatic phase, but when troubles become manifested, they do not much differ from those due to other causes. For this reason this tumor can be diagnosed just when complications caused by its localization and growth develop. Modern cardiologic diagnostics, primarily preventive non-invasive echocardiography, enables timely diagnosis and removal of the tumor because only then it may take a name benign tumor.

[Intimomedial thickness of the vertebral arteries complex: a new useful parameter for the assessment of atheroclerotic process?].

BACKGROUND/AIM: An integral part of Doppler ultrasound examination of cervical blood vessels is determination of intimomedial thicknes (IMT) of the common carotid. The aim of the study was to estimate the relations between IMT of the common carotid and vertebral arteries in order to determine if the value of IMT obtained on the vertebral artery could be applied in clinical practice. METHODS: We measured IMT in a randomized, prospective and cross-sectional study, performed on 50 persons both sexes (29 men and 21 women), at the age from 18 to 79 years (mean age 52.4 +/- 17.63 years). All the persons were healthy, what was confirmed with clinical examination and laboratory analyses. Measurements were perfomed from January 2006 until September 2008. Intimomedial thickness was recorded by two dimensional ultrasonography in B-mode on both common carotid arteries: one value was obtained as average of three successeful measurements (measurements were perform on different places). We measured IMT on the first segment of both vertebral arteries, 1.5 cm proximal from the connection of the first and second segments (we got results of the measurement of IMT on the vertebral arteries in the same way: mean value from the three records). RESULTS: The measured value of IMT on the common carotid arteries (IMT = 0.782 +/- 0.248 mm), obtained from 50 healthy persons, was higher than that measured on the vertabral artery on the first segment (IMT = 0.585 +/- 0.134 mm). The values of IMT after measurement on two different places were statistically highly different (t = 7.03, SD = 0.028, p < 0.01). Coefficient of variability of IMT values in carotid circulation (CV = 34.4%) was higher than that in vertebral circulation (22.9%). Values of IMT on vertebral arteries were in statistically significant correlation with those in carotid circulation (r = 0.24 and t- = 2.48; p < 0.02). There were no statistically significant difference between IMT measurement on the right and the left side so they were analysed as the same set. CONCLUSION: Values of IMT on the vertebral arteries are one more undependent parameter of Doppler-sonographic examination of cervical vessels, which significantly correlates with IMT values on common carotid artery. Variability of this parameter is lower, and absolute values lower than the same in the common carotid artery. Therefore, this parameter is probably not so sensitive. On the other hand, lower variability of IMT values on the vertebral artery might be of higher specificity for prediction of atherosclerotic progress by the increased values of this parameter than based on IMT values obtained on the common carotid arteries.

[Diagnosis and results of treatment of heart myxoma].

BACKGROUND/AIM: Myxoma is the most common benign primary cardiac neoplasm, and usually originates from the left atrial septum. Early diagnosis of cardiac myxomas depends on a high index of a clinical suspicion. Surgical management must be done as soon as possible after diagnosis. The aim of this retrospective study was to present diagnostics and treatment outcome data of 61 patients with cardiac myxoma treated in the Military Medical Academy, Belgrade during a 49-years period. METHODS: Intra-hospital diagnosis was established in all the patients by the cardiologist. Diagnostic methods were various, in dependence on the examination period and suspected diagnosis. RESULTS: Within a 49-years period (1961-2009) heart myxoma was diagnozed and treated in 61 patients in the Military Medical Academy, Belgrade. Most of the operated patients were females (38 or 62.3%). The operated patients were 19-68 years old. Average age of all the patients was 47.9%. The great majority of them (98.4%) had atrial, and only one operated patient had ventricular myxoma. In 13 (21.3%) of the patients heart myxoma was found out accidentally due to no previous cardiologic symptomatology. In most patients (27.44%) symptomatology was presented as thromboembolic disease. Because of the suspected ventricular myxoma in one patient, the patient was operated on, but Hodgkin's lymphoma was found out which, according to the subsequent course of the disease, could be justifiably recognized as primary heart lymphoma. This study presented brief descriptions of the course of the disease in 4 patients with myxomas in each of the cardiac cavities. CONCLUSION: The only diagnostic difficulty in cardiac myxoma is due to its asymptomatic and oligosymptomatic presence within the longer period of time, namely, its growth period. Echocardiography should be the standard method of cardiologic examination of these patients, which could considerably contribute to early diagnosis and treatment of heart myxoma. Surgical extirpation of myxoma is the only and very successful therapeutic method.

The cardioprotective role of preinfarction angina as shown in outcomes of patients after first myocardial infarction.

This prospective study evaluated the relationship between preinfarction angina (2 months before a 1st acute myocardial infarction) and the extent of postinfarction myocardial injury, myocardial perfusion, contractile function, and late recovery of global left ventricular contractile function. We enrolled 46 patients who had been admitted for a 1st, single-vessel-disease, acute myocardial infarction. Low-dose dobutamine echocardiography and technetium-99m-tetrofosmin scintigraphy were performed on all patients 7 to 10 days after acute myocardial infarction; and resting echocardiography was performed 7 to 12 months later. Twenty-seven of 46 (58.7%) patients had experienced angina before acute myocardial infarction, and 19 of 46 (41.3%) had not. There was no difference between the 2 groups in acute basal left ventricular ejection fraction (P=0.17) or in basal wall motion score index (P=0.521). The maximal creatine kinase-MB level was lower in the preinfarction-angina group (P=0.039). Patients with preinfarction angina had significantly more myocardial segments with preserved regional contractile function (P <0.0001) and significantly fewer segments with less than 50% perfusion (P=0.008). Stepwise regression analysis identified preinfarction angina (r2=0.317, P=0.032) as a significant predictor of the percentage of left ventricular ejection fraction recovery after the follow-up period. In our study, preinfarction angina was associated with decreased infarct size and with better protection of global and regional left ventricular contractility and improved preservation of the microvasculature. A history of preinfarction angina should be of value in predicting the late clinical outcomes of patients after a 1st acute myocardial infarction.

[Management of refractory angina pectoris]. / Lecenje refraktorne angine pektoris.

An increasing number of patients with coronary artery disease have ischemic symptoms that are unresponsive to both conventional medical therapy and revascularization techniques. The objective of this study was to define the population of patients with refractory angina pectoris and to present the therapeutic options currently available for this condition. Among many techniques, the enhanced external counterpulsation, transmyocardial laser revascularization and neurostimulation have been shown to reduce angina and to improve objective measures of myocardial ischemia in patients with refractory angina.